]>
Commit | Line | Data |
---|---|---|
70482933 RK |
1 | ------------------------------------------------------------------------------ |
2 | -- -- | |
3 | -- GNAT COMPILER COMPONENTS -- | |
4 | -- -- | |
5 | -- C H E C K S -- | |
6 | -- -- | |
7 | -- B o d y -- | |
8 | -- -- | |
1d005acc | 9 | -- Copyright (C) 1992-2019, Free Software Foundation, Inc. -- |
70482933 RK |
10 | -- -- |
11 | -- GNAT is free software; you can redistribute it and/or modify it under -- | |
12 | -- terms of the GNU General Public License as published by the Free Soft- -- | |
b5c84c3c | 13 | -- ware Foundation; either version 3, or (at your option) any later ver- -- |
70482933 RK |
14 | -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- |
15 | -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- | |
16 | -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- | |
17 | -- for more details. You should have received a copy of the GNU General -- | |
b5c84c3c RD |
18 | -- Public License distributed with GNAT; see file COPYING3. If not, go to -- |
19 | -- http://www.gnu.org/licenses for a complete copy of the license. -- | |
70482933 RK |
20 | -- -- |
21 | -- GNAT was originally developed by the GNAT team at New York University. -- | |
71ff80dc | 22 | -- Extensive contributions were provided by Ada Core Technologies Inc. -- |
70482933 RK |
23 | -- -- |
24 | ------------------------------------------------------------------------------ | |
25 | ||
26 | with Atree; use Atree; | |
f7ea2603 | 27 | with Casing; use Casing; |
70482933 RK |
28 | with Debug; use Debug; |
29 | with Einfo; use Einfo; | |
aca670a0 AC |
30 | with Elists; use Elists; |
31 | with Eval_Fat; use Eval_Fat; | |
32 | with Exp_Ch11; use Exp_Ch11; | |
70482933 | 33 | with Exp_Ch2; use Exp_Ch2; |
fdfcc663 | 34 | with Exp_Ch4; use Exp_Ch4; |
d8b9660d | 35 | with Exp_Pakd; use Exp_Pakd; |
70482933 | 36 | with Exp_Util; use Exp_Util; |
a40ada7e | 37 | with Expander; use Expander; |
70482933 | 38 | with Freeze; use Freeze; |
fbf5a39b | 39 | with Lib; use Lib; |
70482933 RK |
40 | with Nlists; use Nlists; |
41 | with Nmake; use Nmake; | |
42 | with Opt; use Opt; | |
fbf5a39b | 43 | with Output; use Output; |
980f237d | 44 | with Restrict; use Restrict; |
6e937c1c | 45 | with Rident; use Rident; |
70482933 RK |
46 | with Rtsfind; use Rtsfind; |
47 | with Sem; use Sem; | |
a4100e55 | 48 | with Sem_Aux; use Sem_Aux; |
5d09245e | 49 | with Sem_Ch3; use Sem_Ch3; |
fbf5a39b | 50 | with Sem_Ch8; use Sem_Ch8; |
7327f5c2 | 51 | with Sem_Disp; use Sem_Disp; |
aca670a0 | 52 | with Sem_Eval; use Sem_Eval; |
155f4f34 | 53 | with Sem_Mech; use Sem_Mech; |
70482933 RK |
54 | with Sem_Res; use Sem_Res; |
55 | with Sem_Util; use Sem_Util; | |
56 | with Sem_Warn; use Sem_Warn; | |
57 | with Sinfo; use Sinfo; | |
fbf5a39b | 58 | with Sinput; use Sinput; |
70482933 | 59 | with Snames; use Snames; |
fbf5a39b | 60 | with Sprint; use Sprint; |
70482933 | 61 | with Stand; use Stand; |
baed70ac | 62 | with Stringt; use Stringt; |
07fc65c4 | 63 | with Targparm; use Targparm; |
70482933 RK |
64 | with Tbuild; use Tbuild; |
65 | with Ttypes; use Ttypes; | |
70482933 RK |
66 | with Validsw; use Validsw; |
67 | ||
68 | package body Checks is | |
69 | ||
70 | -- General note: many of these routines are concerned with generating | |
71 | -- checking code to make sure that constraint error is raised at runtime. | |
72 | -- Clearly this code is only needed if the expander is active, since | |
73 | -- otherwise we will not be generating code or going into the runtime | |
74 | -- execution anyway. | |
75 | ||
76 | -- We therefore disconnect most of these checks if the expander is | |
77 | -- inactive. This has the additional benefit that we do not need to | |
78 | -- worry about the tree being messed up by previous errors (since errors | |
79 | -- turn off expansion anyway). | |
80 | ||
81 | -- There are a few exceptions to the above rule. For instance routines | |
82 | -- such as Apply_Scalar_Range_Check that do not insert any code can be | |
83 | -- safely called even when the Expander is inactive (but Errors_Detected | |
84 | -- is 0). The benefit of executing this code when expansion is off, is | |
85 | -- the ability to emit constraint error warning for static expressions | |
86 | -- even when we are not generating code. | |
87 | ||
637a41a5 AC |
88 | -- The above is modified in gnatprove mode to ensure that proper check |
89 | -- flags are always placed, even if expansion is off. | |
90 | ||
fbf5a39b AC |
91 | ------------------------------------- |
92 | -- Suppression of Redundant Checks -- | |
93 | ------------------------------------- | |
94 | ||
95 | -- This unit implements a limited circuit for removal of redundant | |
96 | -- checks. The processing is based on a tracing of simple sequential | |
97 | -- flow. For any sequence of statements, we save expressions that are | |
98 | -- marked to be checked, and then if the same expression appears later | |
99 | -- with the same check, then under certain circumstances, the second | |
100 | -- check can be suppressed. | |
101 | ||
102 | -- Basically, we can suppress the check if we know for certain that | |
103 | -- the previous expression has been elaborated (together with its | |
104 | -- check), and we know that the exception frame is the same, and that | |
105 | -- nothing has happened to change the result of the exception. | |
106 | ||
107 | -- Let us examine each of these three conditions in turn to describe | |
108 | -- how we ensure that this condition is met. | |
109 | ||
110 | -- First, we need to know for certain that the previous expression has | |
308e6f3a | 111 | -- been executed. This is done principally by the mechanism of calling |
fbf5a39b AC |
112 | -- Conditional_Statements_Begin at the start of any statement sequence |
113 | -- and Conditional_Statements_End at the end. The End call causes all | |
114 | -- checks remembered since the Begin call to be discarded. This does | |
115 | -- miss a few cases, notably the case of a nested BEGIN-END block with | |
116 | -- no exception handlers. But the important thing is to be conservative. | |
117 | -- The other protection is that all checks are discarded if a label | |
118 | -- is encountered, since then the assumption of sequential execution | |
119 | -- is violated, and we don't know enough about the flow. | |
120 | ||
121 | -- Second, we need to know that the exception frame is the same. We | |
122 | -- do this by killing all remembered checks when we enter a new frame. | |
123 | -- Again, that's over-conservative, but generally the cases we can help | |
124 | -- with are pretty local anyway (like the body of a loop for example). | |
125 | ||
126 | -- Third, we must be sure to forget any checks which are no longer valid. | |
127 | -- This is done by two mechanisms, first the Kill_Checks_Variable call is | |
128 | -- used to note any changes to local variables. We only attempt to deal | |
129 | -- with checks involving local variables, so we do not need to worry | |
130 | -- about global variables. Second, a call to any non-global procedure | |
131 | -- causes us to abandon all stored checks, since such a all may affect | |
132 | -- the values of any local variables. | |
133 | ||
134 | -- The following define the data structures used to deal with remembering | |
135 | -- checks so that redundant checks can be eliminated as described above. | |
136 | ||
137 | -- Right now, the only expressions that we deal with are of the form of | |
138 | -- simple local objects (either declared locally, or IN parameters) or | |
139 | -- such objects plus/minus a compile time known constant. We can do | |
140 | -- more later on if it seems worthwhile, but this catches many simple | |
141 | -- cases in practice. | |
142 | ||
143 | -- The following record type reflects a single saved check. An entry | |
144 | -- is made in the stack of saved checks if and only if the expression | |
145 | -- has been elaborated with the indicated checks. | |
146 | ||
147 | type Saved_Check is record | |
148 | Killed : Boolean; | |
149 | -- Set True if entry is killed by Kill_Checks | |
150 | ||
151 | Entity : Entity_Id; | |
152 | -- The entity involved in the expression that is checked | |
153 | ||
154 | Offset : Uint; | |
155 | -- A compile time value indicating the result of adding or | |
156 | -- subtracting a compile time value. This value is to be | |
157 | -- added to the value of the Entity. A value of zero is | |
158 | -- used for the case of a simple entity reference. | |
159 | ||
160 | Check_Type : Character; | |
161 | -- This is set to 'R' for a range check (in which case Target_Type | |
162 | -- is set to the target type for the range check) or to 'O' for an | |
163 | -- overflow check (in which case Target_Type is set to Empty). | |
164 | ||
165 | Target_Type : Entity_Id; | |
166 | -- Used only if Do_Range_Check is set. Records the target type for | |
167 | -- the check. We need this, because a check is a duplicate only if | |
308e6f3a | 168 | -- it has the same target type (or more accurately one with a |
fbf5a39b AC |
169 | -- range that is smaller or equal to the stored target type of a |
170 | -- saved check). | |
171 | end record; | |
172 | ||
173 | -- The following table keeps track of saved checks. Rather than use an | |
d1915cb8 | 174 | -- extensible table, we just use a table of fixed size, and we discard |
fbf5a39b AC |
175 | -- any saved checks that do not fit. That's very unlikely to happen and |
176 | -- this is only an optimization in any case. | |
177 | ||
178 | Saved_Checks : array (Int range 1 .. 200) of Saved_Check; | |
179 | -- Array of saved checks | |
180 | ||
181 | Num_Saved_Checks : Nat := 0; | |
182 | -- Number of saved checks | |
183 | ||
184 | -- The following stack keeps track of statement ranges. It is treated | |
185 | -- as a stack. When Conditional_Statements_Begin is called, an entry | |
186 | -- is pushed onto this stack containing the value of Num_Saved_Checks | |
187 | -- at the time of the call. Then when Conditional_Statements_End is | |
188 | -- called, this value is popped off and used to reset Num_Saved_Checks. | |
189 | ||
190 | -- Note: again, this is a fixed length stack with a size that should | |
191 | -- always be fine. If the value of the stack pointer goes above the | |
192 | -- limit, then we just forget all saved checks. | |
193 | ||
194 | Saved_Checks_Stack : array (Int range 1 .. 100) of Nat; | |
195 | Saved_Checks_TOS : Nat := 0; | |
196 | ||
197 | ----------------------- | |
198 | -- Local Subprograms -- | |
199 | ----------------------- | |
70482933 | 200 | |
a7f1b24f | 201 | procedure Apply_Arithmetic_Overflow_Strict (N : Node_Id); |
acad3c0a | 202 | -- Used to apply arithmetic overflow checks for all cases except operators |
3ada950b | 203 | -- on signed arithmetic types in MINIMIZED/ELIMINATED case (for which we |
a7f1b24f RD |
204 | -- call Apply_Arithmetic_Overflow_Minimized_Eliminated below). N can be a |
205 | -- signed integer arithmetic operator (but not an if or case expression). | |
206 | -- It is also called for types other than signed integers. | |
acad3c0a AC |
207 | |
208 | procedure Apply_Arithmetic_Overflow_Minimized_Eliminated (Op : Node_Id); | |
209 | -- Used to apply arithmetic overflow checks for the case where the overflow | |
a7f1b24f RD |
210 | -- checking mode is MINIMIZED or ELIMINATED and we have a signed integer |
211 | -- arithmetic op (which includes the case of if and case expressions). Note | |
212 | -- that Do_Overflow_Check may or may not be set for node Op. In these modes | |
213 | -- we have work to do even if overflow checking is suppressed. | |
acad3c0a | 214 | |
a91e9ac7 AC |
215 | procedure Apply_Division_Check |
216 | (N : Node_Id; | |
217 | Rlo : Uint; | |
218 | Rhi : Uint; | |
219 | ROK : Boolean); | |
220 | -- N is an N_Op_Div, N_Op_Rem, or N_Op_Mod node. This routine applies | |
221 | -- division checks as required if the Do_Division_Check flag is set. | |
222 | -- Rlo and Rhi give the possible range of the right operand, these values | |
223 | -- can be referenced and trusted only if ROK is set True. | |
224 | ||
225 | procedure Apply_Float_Conversion_Check | |
226 | (Ck_Node : Node_Id; | |
227 | Target_Typ : Entity_Id); | |
228 | -- The checks on a conversion from a floating-point type to an integer | |
229 | -- type are delicate. They have to be performed before conversion, they | |
230 | -- have to raise an exception when the operand is a NaN, and rounding must | |
231 | -- be taken into account to determine the safe bounds of the operand. | |
232 | ||
70482933 RK |
233 | procedure Apply_Selected_Length_Checks |
234 | (Ck_Node : Node_Id; | |
235 | Target_Typ : Entity_Id; | |
236 | Source_Typ : Entity_Id; | |
237 | Do_Static : Boolean); | |
238 | -- This is the subprogram that does all the work for Apply_Length_Check | |
239 | -- and Apply_Static_Length_Check. Expr, Target_Typ and Source_Typ are as | |
240 | -- described for the above routines. The Do_Static flag indicates that | |
241 | -- only a static check is to be done. | |
242 | ||
243 | procedure Apply_Selected_Range_Checks | |
244 | (Ck_Node : Node_Id; | |
245 | Target_Typ : Entity_Id; | |
246 | Source_Typ : Entity_Id; | |
247 | Do_Static : Boolean); | |
248 | -- This is the subprogram that does all the work for Apply_Range_Check. | |
249 | -- Expr, Target_Typ and Source_Typ are as described for the above | |
250 | -- routine. The Do_Static flag indicates that only a static check is | |
251 | -- to be done. | |
252 | ||
939c12d2 | 253 | type Check_Type is new Check_Id range Access_Check .. Division_Check; |
2ede092b RD |
254 | function Check_Needed (Nod : Node_Id; Check : Check_Type) return Boolean; |
255 | -- This function is used to see if an access or division by zero check is | |
256 | -- needed. The check is to be applied to a single variable appearing in the | |
257 | -- source, and N is the node for the reference. If N is not of this form, | |
258 | -- True is returned with no further processing. If N is of the right form, | |
259 | -- then further processing determines if the given Check is needed. | |
260 | -- | |
261 | -- The particular circuit is to see if we have the case of a check that is | |
262 | -- not needed because it appears in the right operand of a short circuited | |
263 | -- conditional where the left operand guards the check. For example: | |
264 | -- | |
265 | -- if Var = 0 or else Q / Var > 12 then | |
266 | -- ... | |
267 | -- end if; | |
268 | -- | |
269 | -- In this example, the division check is not required. At the same time | |
270 | -- we can issue warnings for suspicious use of non-short-circuited forms, | |
271 | -- such as: | |
272 | -- | |
273 | -- if Var = 0 or Q / Var > 12 then | |
274 | -- ... | |
275 | -- end if; | |
276 | ||
fbf5a39b AC |
277 | procedure Find_Check |
278 | (Expr : Node_Id; | |
279 | Check_Type : Character; | |
280 | Target_Type : Entity_Id; | |
281 | Entry_OK : out Boolean; | |
282 | Check_Num : out Nat; | |
283 | Ent : out Entity_Id; | |
284 | Ofs : out Uint); | |
285 | -- This routine is used by Enable_Range_Check and Enable_Overflow_Check | |
286 | -- to see if a check is of the form for optimization, and if so, to see | |
287 | -- if it has already been performed. Expr is the expression to check, | |
288 | -- and Check_Type is 'R' for a range check, 'O' for an overflow check. | |
289 | -- Target_Type is the target type for a range check, and Empty for an | |
290 | -- overflow check. If the entry is not of the form for optimization, | |
291 | -- then Entry_OK is set to False, and the remaining out parameters | |
292 | -- are undefined. If the entry is OK, then Ent/Ofs are set to the | |
293 | -- entity and offset from the expression. Check_Num is the number of | |
294 | -- a matching saved entry in Saved_Checks, or zero if no such entry | |
295 | -- is located. | |
296 | ||
70482933 RK |
297 | function Get_Discriminal (E : Entity_Id; Bound : Node_Id) return Node_Id; |
298 | -- If a discriminal is used in constraining a prival, Return reference | |
299 | -- to the discriminal of the protected body (which renames the parameter | |
300 | -- of the enclosing protected operation). This clumsy transformation is | |
301 | -- needed because privals are created too late and their actual subtypes | |
302 | -- are not available when analysing the bodies of the protected operations. | |
c064e066 RD |
303 | -- This function is called whenever the bound is an entity and the scope |
304 | -- indicates a protected operation. If the bound is an in-parameter of | |
305 | -- a protected operation that is not a prival, the function returns the | |
306 | -- bound itself. | |
70482933 RK |
307 | -- To be cleaned up??? |
308 | ||
309 | function Guard_Access | |
310 | (Cond : Node_Id; | |
311 | Loc : Source_Ptr; | |
6b6fcd3e | 312 | Ck_Node : Node_Id) return Node_Id; |
70482933 RK |
313 | -- In the access type case, guard the test with a test to ensure |
314 | -- that the access value is non-null, since the checks do not | |
315 | -- not apply to null access values. | |
316 | ||
317 | procedure Install_Static_Check (R_Cno : Node_Id; Loc : Source_Ptr); | |
318 | -- Called by Apply_{Length,Range}_Checks to rewrite the tree with the | |
319 | -- Constraint_Error node. | |
320 | ||
acad3c0a AC |
321 | function Is_Signed_Integer_Arithmetic_Op (N : Node_Id) return Boolean; |
322 | -- Returns True if node N is for an arithmetic operation with signed | |
4b1c4f20 RD |
323 | -- integer operands. This includes unary and binary operators, and also |
324 | -- if and case expression nodes where the dependent expressions are of | |
325 | -- a signed integer type. These are the kinds of nodes for which special | |
3ada950b | 326 | -- handling applies in MINIMIZED or ELIMINATED overflow checking mode. |
acad3c0a | 327 | |
c064e066 RD |
328 | function Range_Or_Validity_Checks_Suppressed |
329 | (Expr : Node_Id) return Boolean; | |
330 | -- Returns True if either range or validity checks or both are suppressed | |
331 | -- for the type of the given expression, or, if the expression is the name | |
332 | -- of an entity, if these checks are suppressed for the entity. | |
333 | ||
70482933 RK |
334 | function Selected_Length_Checks |
335 | (Ck_Node : Node_Id; | |
336 | Target_Typ : Entity_Id; | |
337 | Source_Typ : Entity_Id; | |
6b6fcd3e | 338 | Warn_Node : Node_Id) return Check_Result; |
70482933 RK |
339 | -- Like Apply_Selected_Length_Checks, except it doesn't modify |
340 | -- anything, just returns a list of nodes as described in the spec of | |
341 | -- this package for the Range_Check function. | |
66340e0e AC |
342 | -- ??? In fact it does construct the test and insert it into the tree, |
343 | -- and insert actions in various ways (calling Insert_Action directly | |
344 | -- in particular) so we do not call it in GNATprove mode, contrary to | |
345 | -- Selected_Range_Checks. | |
70482933 RK |
346 | |
347 | function Selected_Range_Checks | |
348 | (Ck_Node : Node_Id; | |
349 | Target_Typ : Entity_Id; | |
350 | Source_Typ : Entity_Id; | |
6b6fcd3e | 351 | Warn_Node : Node_Id) return Check_Result; |
70482933 RK |
352 | -- Like Apply_Selected_Range_Checks, except it doesn't modify anything, |
353 | -- just returns a list of nodes as described in the spec of this package | |
354 | -- for the Range_Check function. | |
355 | ||
356 | ------------------------------ | |
357 | -- Access_Checks_Suppressed -- | |
358 | ------------------------------ | |
359 | ||
360 | function Access_Checks_Suppressed (E : Entity_Id) return Boolean is | |
361 | begin | |
fbf5a39b AC |
362 | if Present (E) and then Checks_May_Be_Suppressed (E) then |
363 | return Is_Check_Suppressed (E, Access_Check); | |
364 | else | |
3217f71e | 365 | return Scope_Suppress.Suppress (Access_Check); |
fbf5a39b | 366 | end if; |
70482933 RK |
367 | end Access_Checks_Suppressed; |
368 | ||
369 | ------------------------------------- | |
370 | -- Accessibility_Checks_Suppressed -- | |
371 | ------------------------------------- | |
372 | ||
373 | function Accessibility_Checks_Suppressed (E : Entity_Id) return Boolean is | |
374 | begin | |
fbf5a39b AC |
375 | if Present (E) and then Checks_May_Be_Suppressed (E) then |
376 | return Is_Check_Suppressed (E, Accessibility_Check); | |
377 | else | |
3217f71e | 378 | return Scope_Suppress.Suppress (Accessibility_Check); |
fbf5a39b | 379 | end if; |
70482933 RK |
380 | end Accessibility_Checks_Suppressed; |
381 | ||
11b4899f JM |
382 | ----------------------------- |
383 | -- Activate_Division_Check -- | |
384 | ----------------------------- | |
385 | ||
386 | procedure Activate_Division_Check (N : Node_Id) is | |
387 | begin | |
388 | Set_Do_Division_Check (N, True); | |
389 | Possible_Local_Raise (N, Standard_Constraint_Error); | |
390 | end Activate_Division_Check; | |
391 | ||
392 | ----------------------------- | |
393 | -- Activate_Overflow_Check -- | |
394 | ----------------------------- | |
395 | ||
396 | procedure Activate_Overflow_Check (N : Node_Id) is | |
bb304287 AC |
397 | Typ : constant Entity_Id := Etype (N); |
398 | ||
11b4899f | 399 | begin |
bb304287 AC |
400 | -- Floating-point case. If Etype is not set (this can happen when we |
401 | -- activate a check on a node that has not yet been analyzed), then | |
402 | -- we assume we do not have a floating-point type (as per our spec). | |
403 | ||
404 | if Present (Typ) and then Is_Floating_Point_Type (Typ) then | |
405 | ||
406 | -- Ignore call if we have no automatic overflow checks on the target | |
407 | -- and Check_Float_Overflow mode is not set. These are the cases in | |
408 | -- which we expect to generate infinities and NaN's with no check. | |
409 | ||
410 | if not (Machine_Overflows_On_Target or Check_Float_Overflow) then | |
411 | return; | |
412 | ||
413 | -- Ignore for unary operations ("+", "-", abs) since these can never | |
414 | -- result in overflow for floating-point cases. | |
396eb900 | 415 | |
bb304287 AC |
416 | elsif Nkind (N) in N_Unary_Op then |
417 | return; | |
418 | ||
419 | -- Otherwise we will set the flag | |
420 | ||
421 | else | |
422 | null; | |
423 | end if; | |
424 | ||
425 | -- Discrete case | |
426 | ||
427 | else | |
428 | -- Nothing to do for Rem/Mod/Plus (overflow not possible, the check | |
429 | -- for zero-divide is a divide check, not an overflow check). | |
396eb900 | 430 | |
bb304287 AC |
431 | if Nkind_In (N, N_Op_Rem, N_Op_Mod, N_Op_Plus) then |
432 | return; | |
433 | end if; | |
396eb900 AC |
434 | end if; |
435 | ||
bb304287 | 436 | -- Fall through for cases where we do set the flag |
396eb900 | 437 | |
a7191e01 | 438 | Set_Do_Overflow_Check (N); |
396eb900 | 439 | Possible_Local_Raise (N, Standard_Constraint_Error); |
11b4899f JM |
440 | end Activate_Overflow_Check; |
441 | ||
442 | -------------------------- | |
443 | -- Activate_Range_Check -- | |
444 | -------------------------- | |
445 | ||
446 | procedure Activate_Range_Check (N : Node_Id) is | |
447 | begin | |
68c8d72a | 448 | Set_Do_Range_Check (N); |
11b4899f JM |
449 | Possible_Local_Raise (N, Standard_Constraint_Error); |
450 | end Activate_Range_Check; | |
451 | ||
c064e066 RD |
452 | --------------------------------- |
453 | -- Alignment_Checks_Suppressed -- | |
454 | --------------------------------- | |
455 | ||
456 | function Alignment_Checks_Suppressed (E : Entity_Id) return Boolean is | |
457 | begin | |
458 | if Present (E) and then Checks_May_Be_Suppressed (E) then | |
459 | return Is_Check_Suppressed (E, Alignment_Check); | |
460 | else | |
3217f71e | 461 | return Scope_Suppress.Suppress (Alignment_Check); |
c064e066 RD |
462 | end if; |
463 | end Alignment_Checks_Suppressed; | |
464 | ||
b07b7ace AC |
465 | ---------------------------------- |
466 | -- Allocation_Checks_Suppressed -- | |
467 | ---------------------------------- | |
468 | ||
59f4d038 RD |
469 | -- Note: at the current time there are no calls to this function, because |
470 | -- the relevant check is in the run-time, so it is not a check that the | |
471 | -- compiler can suppress anyway, but we still have to recognize the check | |
472 | -- name Allocation_Check since it is part of the standard. | |
473 | ||
b07b7ace AC |
474 | function Allocation_Checks_Suppressed (E : Entity_Id) return Boolean is |
475 | begin | |
476 | if Present (E) and then Checks_May_Be_Suppressed (E) then | |
477 | return Is_Check_Suppressed (E, Allocation_Check); | |
478 | else | |
479 | return Scope_Suppress.Suppress (Allocation_Check); | |
480 | end if; | |
481 | end Allocation_Checks_Suppressed; | |
482 | ||
70482933 RK |
483 | ------------------------- |
484 | -- Append_Range_Checks -- | |
485 | ------------------------- | |
486 | ||
487 | procedure Append_Range_Checks | |
488 | (Checks : Check_Result; | |
489 | Stmts : List_Id; | |
490 | Suppress_Typ : Entity_Id; | |
491 | Static_Sloc : Source_Ptr; | |
492 | Flag_Node : Node_Id) | |
493 | is | |
e0666fc6 AC |
494 | Checks_On : constant Boolean := |
495 | not Index_Checks_Suppressed (Suppress_Typ) | |
496 | or else | |
497 | not Range_Checks_Suppressed (Suppress_Typ); | |
498 | ||
fbf5a39b AC |
499 | Internal_Flag_Node : constant Node_Id := Flag_Node; |
500 | Internal_Static_Sloc : constant Source_Ptr := Static_Sloc; | |
501 | ||
70482933 | 502 | begin |
e0666fc6 AC |
503 | -- For now we just return if Checks_On is false, however this should be |
504 | -- enhanced to check for an always True value in the condition and to | |
505 | -- generate a compilation warning??? | |
70482933 RK |
506 | |
507 | if not Checks_On then | |
508 | return; | |
509 | end if; | |
510 | ||
511 | for J in 1 .. 2 loop | |
512 | exit when No (Checks (J)); | |
513 | ||
514 | if Nkind (Checks (J)) = N_Raise_Constraint_Error | |
515 | and then Present (Condition (Checks (J))) | |
516 | then | |
517 | if not Has_Dynamic_Range_Check (Internal_Flag_Node) then | |
518 | Append_To (Stmts, Checks (J)); | |
519 | Set_Has_Dynamic_Range_Check (Internal_Flag_Node); | |
520 | end if; | |
521 | ||
522 | else | |
523 | Append_To | |
07fc65c4 GB |
524 | (Stmts, |
525 | Make_Raise_Constraint_Error (Internal_Static_Sloc, | |
526 | Reason => CE_Range_Check_Failed)); | |
70482933 RK |
527 | end if; |
528 | end loop; | |
529 | end Append_Range_Checks; | |
530 | ||
531 | ------------------------ | |
532 | -- Apply_Access_Check -- | |
533 | ------------------------ | |
534 | ||
535 | procedure Apply_Access_Check (N : Node_Id) is | |
536 | P : constant Node_Id := Prefix (N); | |
537 | ||
538 | begin | |
2ede092b RD |
539 | -- We do not need checks if we are not generating code (i.e. the |
540 | -- expander is not active). This is not just an optimization, there | |
541 | -- are cases (e.g. with pragma Debug) where generating the checks | |
542 | -- can cause real trouble). | |
6cdb2c6e | 543 | |
4460a9bc | 544 | if not Expander_Active then |
2ede092b | 545 | return; |
fbf5a39b | 546 | end if; |
70482933 | 547 | |
86ac5e79 | 548 | -- No check if short circuiting makes check unnecessary |
fbf5a39b | 549 | |
86ac5e79 ES |
550 | if not Check_Needed (P, Access_Check) then |
551 | return; | |
70482933 | 552 | end if; |
fbf5a39b | 553 | |
f2cbd970 JM |
554 | -- No check if accessing the Offset_To_Top component of a dispatch |
555 | -- table. They are safe by construction. | |
556 | ||
1be9633f AC |
557 | if Tagged_Type_Expansion |
558 | and then Present (Etype (P)) | |
f2cbd970 JM |
559 | and then RTU_Loaded (Ada_Tags) |
560 | and then RTE_Available (RE_Offset_To_Top_Ptr) | |
561 | and then Etype (P) = RTE (RE_Offset_To_Top_Ptr) | |
562 | then | |
563 | return; | |
564 | end if; | |
565 | ||
86ac5e79 | 566 | -- Otherwise go ahead and install the check |
fbf5a39b | 567 | |
2820d220 | 568 | Install_Null_Excluding_Check (P); |
70482933 RK |
569 | end Apply_Access_Check; |
570 | ||
571 | ------------------------------- | |
572 | -- Apply_Accessibility_Check -- | |
573 | ------------------------------- | |
574 | ||
e84e11ba GD |
575 | procedure Apply_Accessibility_Check |
576 | (N : Node_Id; | |
577 | Typ : Entity_Id; | |
578 | Insert_Node : Node_Id) | |
579 | is | |
29c64a0f HK |
580 | Loc : constant Source_Ptr := Sloc (N); |
581 | ||
ccf17305 | 582 | Check_Cond : Node_Id; |
29c64a0f | 583 | Param_Ent : Entity_Id := Param_Entity (N); |
70482933 RK |
584 | Param_Level : Node_Id; |
585 | Type_Level : Node_Id; | |
586 | ||
587 | begin | |
d15f9422 AC |
588 | if Ada_Version >= Ada_2012 |
589 | and then not Present (Param_Ent) | |
590 | and then Is_Entity_Name (N) | |
591 | and then Ekind_In (Entity (N), E_Constant, E_Variable) | |
592 | and then Present (Effective_Extra_Accessibility (Entity (N))) | |
593 | then | |
594 | Param_Ent := Entity (N); | |
595 | while Present (Renamed_Object (Param_Ent)) loop | |
996c8821 | 596 | |
d15f9422 AC |
597 | -- Renamed_Object must return an Entity_Name here |
598 | -- because of preceding "Present (E_E_A (...))" test. | |
599 | ||
600 | Param_Ent := Entity (Renamed_Object (Param_Ent)); | |
601 | end loop; | |
602 | end if; | |
603 | ||
70482933 RK |
604 | if Inside_A_Generic then |
605 | return; | |
606 | ||
d175a2fa AC |
607 | -- Only apply the run-time check if the access parameter has an |
608 | -- associated extra access level parameter and when the level of the | |
609 | -- type is less deep than the level of the access parameter, and | |
610 | -- accessibility checks are not suppressed. | |
70482933 RK |
611 | |
612 | elsif Present (Param_Ent) | |
613 | and then Present (Extra_Accessibility (Param_Ent)) | |
d15f9422 | 614 | and then UI_Gt (Object_Access_Level (N), |
996c8821 | 615 | Deepest_Type_Access_Level (Typ)) |
70482933 RK |
616 | and then not Accessibility_Checks_Suppressed (Param_Ent) |
617 | and then not Accessibility_Checks_Suppressed (Typ) | |
618 | then | |
619 | Param_Level := | |
620 | New_Occurrence_Of (Extra_Accessibility (Param_Ent), Loc); | |
621 | ||
8d21ff60 JS |
622 | -- Use the dynamic accessibility parameter for the function's result |
623 | -- when one has been created instead of statically referring to the | |
624 | -- deepest type level so as to appropriatly handle the rules for | |
625 | -- RM 3.10.2 (10.1/3). | |
626 | ||
627 | if Ekind_In (Scope (Param_Ent), E_Function, | |
628 | E_Operator, | |
629 | E_Subprogram_Type) | |
630 | and then Present (Extra_Accessibility_Of_Result (Scope (Param_Ent))) | |
631 | then | |
632 | Type_Level := | |
633 | New_Occurrence_Of | |
634 | (Extra_Accessibility_Of_Result (Scope (Param_Ent)), Loc); | |
635 | else | |
636 | Type_Level := | |
637 | Make_Integer_Literal (Loc, Deepest_Type_Access_Level (Typ)); | |
638 | end if; | |
70482933 | 639 | |
16b05213 | 640 | -- Raise Program_Error if the accessibility level of the access |
86ac5e79 | 641 | -- parameter is deeper than the level of the target access type. |
70482933 | 642 | |
29c64a0f HK |
643 | Check_Cond := |
644 | Make_Op_Gt (Loc, | |
645 | Left_Opnd => Param_Level, | |
646 | Right_Opnd => Type_Level); | |
ccf17305 | 647 | |
e84e11ba | 648 | Insert_Action (Insert_Node, |
70482933 | 649 | Make_Raise_Program_Error (Loc, |
ccf17305 JS |
650 | Condition => Check_Cond, |
651 | Reason => PE_Accessibility_Check_Failed)); | |
70482933 RK |
652 | |
653 | Analyze_And_Resolve (N); | |
ccf17305 JS |
654 | |
655 | -- If constant folding has happened on the condition for the | |
656 | -- generated error, then warn about it being unconditional. | |
657 | ||
658 | if Nkind (Check_Cond) = N_Identifier | |
659 | and then Entity (Check_Cond) = Standard_True | |
660 | then | |
661 | Error_Msg_Warn := SPARK_Mode /= On; | |
29c64a0f HK |
662 | Error_Msg_N ("accessibility check fails<<", N); |
663 | Error_Msg_N ("\Program_Error [<<", N); | |
ccf17305 | 664 | end if; |
70482933 RK |
665 | end if; |
666 | end Apply_Accessibility_Check; | |
667 | ||
c064e066 RD |
668 | -------------------------------- |
669 | -- Apply_Address_Clause_Check -- | |
670 | -------------------------------- | |
671 | ||
672 | procedure Apply_Address_Clause_Check (E : Entity_Id; N : Node_Id) is | |
6f5c2c4b AC |
673 | pragma Assert (Nkind (N) = N_Freeze_Entity); |
674 | ||
80007176 AC |
675 | AC : constant Node_Id := Address_Clause (E); |
676 | Loc : constant Source_Ptr := Sloc (AC); | |
677 | Typ : constant Entity_Id := Etype (E); | |
980f237d | 678 | |
980f237d | 679 | Expr : Node_Id; |
c064e066 RD |
680 | -- Address expression (not necessarily the same as Aexp, for example |
681 | -- when Aexp is a reference to a constant, in which case Expr gets | |
aca670a0 | 682 | -- reset to reference the value expression of the constant). |
c064e066 | 683 | |
980f237d | 684 | begin |
f4cd2542 EB |
685 | -- See if alignment check needed. Note that we never need a check if the |
686 | -- maximum alignment is one, since the check will always succeed. | |
687 | ||
688 | -- Note: we do not check for checks suppressed here, since that check | |
689 | -- was done in Sem_Ch13 when the address clause was processed. We are | |
690 | -- only called if checks were not suppressed. The reason for this is | |
691 | -- that we have to delay the call to Apply_Alignment_Check till freeze | |
692 | -- time (so that all types etc are elaborated), but we have to check | |
693 | -- the status of check suppressing at the point of the address clause. | |
694 | ||
695 | if No (AC) | |
696 | or else not Check_Address_Alignment (AC) | |
697 | or else Maximum_Alignment = 1 | |
698 | then | |
699 | return; | |
700 | end if; | |
701 | ||
702 | -- Obtain expression from address clause | |
fbf5a39b | 703 | |
f26a3587 | 704 | Expr := Address_Value (Expression (AC)); |
c064e066 | 705 | |
f26a3587 AC |
706 | -- See if we know that Expr has an acceptable value at compile time. If |
707 | -- it hasn't or we don't know, we defer issuing the warning until the | |
708 | -- end of the compilation to take into account back end annotations. | |
980f237d GB |
709 | |
710 | if Compile_Time_Known_Value (Expr) | |
ddda9d0f | 711 | and then (Known_Alignment (E) or else Known_Alignment (Typ)) |
980f237d | 712 | then |
ddda9d0f AC |
713 | declare |
714 | AL : Uint := Alignment (Typ); | |
715 | ||
716 | begin | |
80007176 AC |
717 | -- The object alignment might be more restrictive than the type |
718 | -- alignment. | |
ddda9d0f AC |
719 | |
720 | if Known_Alignment (E) then | |
721 | AL := Alignment (E); | |
722 | end if; | |
723 | ||
f26a3587 | 724 | if Expr_Value (Expr) mod AL = 0 then |
c064e066 | 725 | return; |
ddda9d0f AC |
726 | end if; |
727 | end; | |
980f237d | 728 | |
e9c12b91 AC |
729 | -- If the expression has the form X'Address, then we can find out if the |
730 | -- object X has an alignment that is compatible with the object E. If it | |
731 | -- hasn't or we don't know, we defer issuing the warning until the end | |
732 | -- of the compilation to take into account back end annotations. | |
980f237d | 733 | |
c064e066 RD |
734 | elsif Nkind (Expr) = N_Attribute_Reference |
735 | and then Attribute_Name (Expr) = Name_Address | |
e9c12b91 AC |
736 | and then |
737 | Has_Compatible_Alignment (E, Prefix (Expr), False) = Known_Compatible | |
c064e066 | 738 | then |
f4cd2542 | 739 | return; |
c064e066 | 740 | end if; |
980f237d | 741 | |
308e6f3a RW |
742 | -- Here we do not know if the value is acceptable. Strictly we don't |
743 | -- have to do anything, since if the alignment is bad, we have an | |
744 | -- erroneous program. However we are allowed to check for erroneous | |
745 | -- conditions and we decide to do this by default if the check is not | |
746 | -- suppressed. | |
c064e066 RD |
747 | |
748 | -- However, don't do the check if elaboration code is unwanted | |
749 | ||
750 | if Restriction_Active (No_Elaboration_Code) then | |
751 | return; | |
752 | ||
753 | -- Generate a check to raise PE if alignment may be inappropriate | |
754 | ||
755 | else | |
43018f58 | 756 | -- If the original expression is a nonstatic constant, use the name |
80007176 AC |
757 | -- of the constant itself rather than duplicating its initialization |
758 | -- expression, which was extracted above. | |
c064e066 | 759 | |
11b4899f JM |
760 | -- Note: Expr is empty if the address-clause is applied to in-mode |
761 | -- actuals (allowed by 13.1(22)). | |
762 | ||
763 | if not Present (Expr) | |
764 | or else | |
765 | (Is_Entity_Name (Expression (AC)) | |
766 | and then Ekind (Entity (Expression (AC))) = E_Constant | |
80007176 AC |
767 | and then Nkind (Parent (Entity (Expression (AC)))) = |
768 | N_Object_Declaration) | |
c064e066 RD |
769 | then |
770 | Expr := New_Copy_Tree (Expression (AC)); | |
771 | else | |
772 | Remove_Side_Effects (Expr); | |
980f237d | 773 | end if; |
980f237d | 774 | |
6f5c2c4b AC |
775 | if No (Actions (N)) then |
776 | Set_Actions (N, New_List); | |
777 | end if; | |
778 | ||
779 | Prepend_To (Actions (N), | |
c064e066 RD |
780 | Make_Raise_Program_Error (Loc, |
781 | Condition => | |
782 | Make_Op_Ne (Loc, | |
80007176 | 783 | Left_Opnd => |
c064e066 | 784 | Make_Op_Mod (Loc, |
80007176 | 785 | Left_Opnd => |
c064e066 RD |
786 | Unchecked_Convert_To |
787 | (RTE (RE_Integer_Address), Expr), | |
788 | Right_Opnd => | |
789 | Make_Attribute_Reference (Loc, | |
6f5c2c4b | 790 | Prefix => New_Occurrence_Of (E, Loc), |
c064e066 RD |
791 | Attribute_Name => Name_Alignment)), |
792 | Right_Opnd => Make_Integer_Literal (Loc, Uint_0)), | |
80007176 | 793 | Reason => PE_Misaligned_Address_Value)); |
aca670a0 AC |
794 | |
795 | Warning_Msg := No_Error_Msg; | |
6f5c2c4b | 796 | Analyze (First (Actions (N)), Suppress => All_Checks); |
3b4598a7 | 797 | |
f26a3587 | 798 | -- If the above raise action generated a warning message (for example |
aca670a0 AC |
799 | -- from Warn_On_Non_Local_Exception mode with the active restriction |
800 | -- No_Exception_Propagation). | |
801 | ||
802 | if Warning_Msg /= No_Error_Msg then | |
80007176 | 803 | |
aca670a0 AC |
804 | -- If the expression has a known at compile time value, then |
805 | -- once we know the alignment of the type, we can check if the | |
806 | -- exception will be raised or not, and if not, we don't need | |
807 | -- the warning so we will kill the warning later on. | |
808 | ||
809 | if Compile_Time_Known_Value (Expr) then | |
810 | Alignment_Warnings.Append | |
5c13a04e EB |
811 | ((E => E, |
812 | A => Expr_Value (Expr), | |
813 | P => Empty, | |
814 | W => Warning_Msg)); | |
815 | ||
816 | -- Likewise if the expression is of the form X'Address | |
817 | ||
818 | elsif Nkind (Expr) = N_Attribute_Reference | |
819 | and then Attribute_Name (Expr) = Name_Address | |
820 | then | |
821 | Alignment_Warnings.Append | |
822 | ((E => E, | |
823 | A => No_Uint, | |
824 | P => Prefix (Expr), | |
825 | W => Warning_Msg)); | |
3b4598a7 | 826 | |
80007176 AC |
827 | -- Add explanation of the warning generated by the check |
828 | ||
829 | else | |
f26a3587 | 830 | Error_Msg_N |
80007176 AC |
831 | ("\address value may be incompatible with alignment of " |
832 | & "object?X?", AC); | |
f26a3587 | 833 | end if; |
3b4598a7 | 834 | end if; |
6fd0a72a | 835 | |
c064e066 RD |
836 | return; |
837 | end if; | |
fbf5a39b AC |
838 | |
839 | exception | |
80007176 | 840 | |
c064e066 RD |
841 | -- If we have some missing run time component in configurable run time |
842 | -- mode then just skip the check (it is not required in any case). | |
843 | ||
fbf5a39b AC |
844 | when RE_Not_Available => |
845 | return; | |
c064e066 | 846 | end Apply_Address_Clause_Check; |
980f237d | 847 | |
70482933 RK |
848 | ------------------------------------- |
849 | -- Apply_Arithmetic_Overflow_Check -- | |
850 | ------------------------------------- | |
851 | ||
acad3c0a AC |
852 | procedure Apply_Arithmetic_Overflow_Check (N : Node_Id) is |
853 | begin | |
854 | -- Use old routine in almost all cases (the only case we are treating | |
5707e389 | 855 | -- specially is the case of a signed integer arithmetic op with the |
a7f1b24f | 856 | -- overflow checking mode set to MINIMIZED or ELIMINATED). |
acad3c0a | 857 | |
a7f1b24f | 858 | if Overflow_Check_Mode = Strict |
acad3c0a AC |
859 | or else not Is_Signed_Integer_Arithmetic_Op (N) |
860 | then | |
a7f1b24f | 861 | Apply_Arithmetic_Overflow_Strict (N); |
acad3c0a | 862 | |
5707e389 AC |
863 | -- Otherwise use the new routine for the case of a signed integer |
864 | -- arithmetic op, with Do_Overflow_Check set to True, and the checking | |
865 | -- mode is MINIMIZED or ELIMINATED. | |
acad3c0a AC |
866 | |
867 | else | |
868 | Apply_Arithmetic_Overflow_Minimized_Eliminated (N); | |
869 | end if; | |
870 | end Apply_Arithmetic_Overflow_Check; | |
871 | ||
a7f1b24f RD |
872 | -------------------------------------- |
873 | -- Apply_Arithmetic_Overflow_Strict -- | |
874 | -------------------------------------- | |
acad3c0a | 875 | |
13230c68 AC |
876 | -- This routine is called only if the type is an integer type and an |
877 | -- arithmetic overflow check may be needed for op (add, subtract, or | |
878 | -- multiply). This check is performed if Backend_Overflow_Checks_On_Target | |
879 | -- is not enabled and Do_Overflow_Check is set. In this case we expand the | |
ec2dd67a RD |
880 | -- operation into a more complex sequence of tests that ensures that |
881 | -- overflow is properly caught. | |
70482933 | 882 | |
a7f1b24f RD |
883 | -- This is used in CHECKED modes. It is identical to the code for this |
884 | -- cases before the big overflow earthquake, thus ensuring that in this | |
885 | -- modes we have compatible behavior (and reliability) to what was there | |
886 | -- before. It is also called for types other than signed integers, and if | |
887 | -- the Do_Overflow_Check flag is off. | |
acad3c0a AC |
888 | |
889 | -- Note: we also call this routine if we decide in the MINIMIZED case | |
890 | -- to give up and just generate an overflow check without any fuss. | |
891 | ||
a7f1b24f | 892 | procedure Apply_Arithmetic_Overflow_Strict (N : Node_Id) is |
5707e389 AC |
893 | Loc : constant Source_Ptr := Sloc (N); |
894 | Typ : constant Entity_Id := Etype (N); | |
895 | Rtyp : constant Entity_Id := Root_Type (Typ); | |
70482933 RK |
896 | |
897 | begin | |
a7f1b24f RD |
898 | -- Nothing to do if Do_Overflow_Check not set or overflow checks |
899 | -- suppressed. | |
900 | ||
901 | if not Do_Overflow_Check (N) then | |
902 | return; | |
903 | end if; | |
904 | ||
ec2dd67a RD |
905 | -- An interesting special case. If the arithmetic operation appears as |
906 | -- the operand of a type conversion: | |
907 | ||
908 | -- type1 (x op y) | |
909 | ||
910 | -- and all the following conditions apply: | |
911 | ||
912 | -- arithmetic operation is for a signed integer type | |
913 | -- target type type1 is a static integer subtype | |
914 | -- range of x and y are both included in the range of type1 | |
915 | -- range of x op y is included in the range of type1 | |
916 | -- size of type1 is at least twice the result size of op | |
917 | ||
4404c282 | 918 | -- then we don't do an overflow check in any case. Instead, we transform |
ec2dd67a RD |
919 | -- the operation so that we end up with: |
920 | ||
921 | -- type1 (type1 (x) op type1 (y)) | |
922 | ||
923 | -- This avoids intermediate overflow before the conversion. It is | |
924 | -- explicitly permitted by RM 3.5.4(24): | |
925 | ||
926 | -- For the execution of a predefined operation of a signed integer | |
927 | -- type, the implementation need not raise Constraint_Error if the | |
928 | -- result is outside the base range of the type, so long as the | |
929 | -- correct result is produced. | |
930 | ||
931 | -- It's hard to imagine that any programmer counts on the exception | |
932 | -- being raised in this case, and in any case it's wrong coding to | |
933 | -- have this expectation, given the RM permission. Furthermore, other | |
934 | -- Ada compilers do allow such out of range results. | |
935 | ||
936 | -- Note that we do this transformation even if overflow checking is | |
937 | -- off, since this is precisely about giving the "right" result and | |
938 | -- avoiding the need for an overflow check. | |
939 | ||
eaa826f8 RD |
940 | -- Note: this circuit is partially redundant with respect to the similar |
941 | -- processing in Exp_Ch4.Expand_N_Type_Conversion, but the latter deals | |
942 | -- with cases that do not come through here. We still need the following | |
943 | -- processing even with the Exp_Ch4 code in place, since we want to be | |
944 | -- sure not to generate the arithmetic overflow check in these cases | |
945 | -- (Exp_Ch4 would have a hard time removing them once generated). | |
946 | ||
ec2dd67a RD |
947 | if Is_Signed_Integer_Type (Typ) |
948 | and then Nkind (Parent (N)) = N_Type_Conversion | |
70482933 | 949 | then |
b6b5cca8 | 950 | Conversion_Optimization : declare |
ec2dd67a | 951 | Target_Type : constant Entity_Id := |
15f0f591 | 952 | Base_Type (Entity (Subtype_Mark (Parent (N)))); |
ec2dd67a RD |
953 | |
954 | Llo, Lhi : Uint; | |
955 | Rlo, Rhi : Uint; | |
956 | LOK, ROK : Boolean; | |
957 | ||
958 | Vlo : Uint; | |
959 | Vhi : Uint; | |
960 | VOK : Boolean; | |
961 | ||
962 | Tlo : Uint; | |
963 | Thi : Uint; | |
964 | ||
965 | begin | |
966 | if Is_Integer_Type (Target_Type) | |
967 | and then RM_Size (Root_Type (Target_Type)) >= 2 * RM_Size (Rtyp) | |
968 | then | |
969 | Tlo := Expr_Value (Type_Low_Bound (Target_Type)); | |
970 | Thi := Expr_Value (Type_High_Bound (Target_Type)); | |
971 | ||
c800f862 RD |
972 | Determine_Range |
973 | (Left_Opnd (N), LOK, Llo, Lhi, Assume_Valid => True); | |
974 | Determine_Range | |
975 | (Right_Opnd (N), ROK, Rlo, Rhi, Assume_Valid => True); | |
ec2dd67a RD |
976 | |
977 | if (LOK and ROK) | |
978 | and then Tlo <= Llo and then Lhi <= Thi | |
979 | and then Tlo <= Rlo and then Rhi <= Thi | |
980 | then | |
c800f862 | 981 | Determine_Range (N, VOK, Vlo, Vhi, Assume_Valid => True); |
ec2dd67a RD |
982 | |
983 | if VOK and then Tlo <= Vlo and then Vhi <= Thi then | |
984 | Rewrite (Left_Opnd (N), | |
985 | Make_Type_Conversion (Loc, | |
986 | Subtype_Mark => New_Occurrence_Of (Target_Type, Loc), | |
987 | Expression => Relocate_Node (Left_Opnd (N)))); | |
988 | ||
989 | Rewrite (Right_Opnd (N), | |
990 | Make_Type_Conversion (Loc, | |
991 | Subtype_Mark => New_Occurrence_Of (Target_Type, Loc), | |
992 | Expression => Relocate_Node (Right_Opnd (N)))); | |
993 | ||
4fb0b3f0 AC |
994 | -- Rewrite the conversion operand so that the original |
995 | -- node is retained, in order to avoid the warning for | |
996 | -- redundant conversions in Resolve_Type_Conversion. | |
997 | ||
998 | Rewrite (N, Relocate_Node (N)); | |
999 | ||
ec2dd67a | 1000 | Set_Etype (N, Target_Type); |
4fb0b3f0 | 1001 | |
ec2dd67a RD |
1002 | Analyze_And_Resolve (Left_Opnd (N), Target_Type); |
1003 | Analyze_And_Resolve (Right_Opnd (N), Target_Type); | |
1004 | ||
1005 | -- Given that the target type is twice the size of the | |
1006 | -- source type, overflow is now impossible, so we can | |
1007 | -- safely kill the overflow check and return. | |
1008 | ||
1009 | Set_Do_Overflow_Check (N, False); | |
1010 | return; | |
1011 | end if; | |
1012 | end if; | |
1013 | end if; | |
b6b5cca8 | 1014 | end Conversion_Optimization; |
70482933 RK |
1015 | end if; |
1016 | ||
ec2dd67a RD |
1017 | -- Now see if an overflow check is required |
1018 | ||
1019 | declare | |
1020 | Siz : constant Int := UI_To_Int (Esize (Rtyp)); | |
1021 | Dsiz : constant Int := Siz * 2; | |
1022 | Opnod : Node_Id; | |
1023 | Ctyp : Entity_Id; | |
1024 | Opnd : Node_Id; | |
1025 | Cent : RE_Id; | |
70482933 | 1026 | |
ec2dd67a RD |
1027 | begin |
1028 | -- Skip check if back end does overflow checks, or the overflow flag | |
fdfcc663 AC |
1029 | -- is not set anyway, or we are not doing code expansion, or the |
1030 | -- parent node is a type conversion whose operand is an arithmetic | |
1031 | -- operation on signed integers on which the expander can promote | |
0c0c6f49 | 1032 | -- later the operands to type Integer (see Expand_N_Type_Conversion). |
70482933 | 1033 | |
ec2dd67a RD |
1034 | if Backend_Overflow_Checks_On_Target |
1035 | or else not Do_Overflow_Check (N) | |
4460a9bc | 1036 | or else not Expander_Active |
fdfcc663 AC |
1037 | or else (Present (Parent (N)) |
1038 | and then Nkind (Parent (N)) = N_Type_Conversion | |
1039 | and then Integer_Promotion_Possible (Parent (N))) | |
ec2dd67a RD |
1040 | then |
1041 | return; | |
1042 | end if; | |
70482933 | 1043 | |
ec2dd67a RD |
1044 | -- Otherwise, generate the full general code for front end overflow |
1045 | -- detection, which works by doing arithmetic in a larger type: | |
70482933 | 1046 | |
ec2dd67a | 1047 | -- x op y |
70482933 | 1048 | |
ec2dd67a | 1049 | -- is expanded into |
70482933 | 1050 | |
ec2dd67a | 1051 | -- Typ (Checktyp (x) op Checktyp (y)); |
70482933 | 1052 | |
ec2dd67a RD |
1053 | -- where Typ is the type of the original expression, and Checktyp is |
1054 | -- an integer type of sufficient length to hold the largest possible | |
1055 | -- result. | |
70482933 | 1056 | |
ec2dd67a RD |
1057 | -- If the size of check type exceeds the size of Long_Long_Integer, |
1058 | -- we use a different approach, expanding to: | |
70482933 | 1059 | |
ec2dd67a | 1060 | -- typ (xxx_With_Ovflo_Check (Integer_64 (x), Integer (y))) |
70482933 | 1061 | |
ec2dd67a | 1062 | -- where xxx is Add, Multiply or Subtract as appropriate |
70482933 | 1063 | |
ec2dd67a RD |
1064 | -- Find check type if one exists |
1065 | ||
1066 | if Dsiz <= Standard_Integer_Size then | |
1067 | Ctyp := Standard_Integer; | |
70482933 | 1068 | |
ec2dd67a RD |
1069 | elsif Dsiz <= Standard_Long_Long_Integer_Size then |
1070 | Ctyp := Standard_Long_Long_Integer; | |
1071 | ||
ce532f42 | 1072 | -- No check type exists, use runtime call |
70482933 RK |
1073 | |
1074 | else | |
ec2dd67a RD |
1075 | if Nkind (N) = N_Op_Add then |
1076 | Cent := RE_Add_With_Ovflo_Check; | |
70482933 | 1077 | |
ec2dd67a RD |
1078 | elsif Nkind (N) = N_Op_Multiply then |
1079 | Cent := RE_Multiply_With_Ovflo_Check; | |
70482933 | 1080 | |
ec2dd67a RD |
1081 | else |
1082 | pragma Assert (Nkind (N) = N_Op_Subtract); | |
1083 | Cent := RE_Subtract_With_Ovflo_Check; | |
1084 | end if; | |
1085 | ||
1086 | Rewrite (N, | |
1087 | OK_Convert_To (Typ, | |
1088 | Make_Function_Call (Loc, | |
e4494292 | 1089 | Name => New_Occurrence_Of (RTE (Cent), Loc), |
ec2dd67a RD |
1090 | Parameter_Associations => New_List ( |
1091 | OK_Convert_To (RTE (RE_Integer_64), Left_Opnd (N)), | |
1092 | OK_Convert_To (RTE (RE_Integer_64), Right_Opnd (N)))))); | |
70482933 | 1093 | |
ec2dd67a RD |
1094 | Analyze_And_Resolve (N, Typ); |
1095 | return; | |
1096 | end if; | |
70482933 | 1097 | |
ec2dd67a RD |
1098 | -- If we fall through, we have the case where we do the arithmetic |
1099 | -- in the next higher type and get the check by conversion. In these | |
1100 | -- cases Ctyp is set to the type to be used as the check type. | |
70482933 | 1101 | |
ec2dd67a | 1102 | Opnod := Relocate_Node (N); |
70482933 | 1103 | |
ec2dd67a | 1104 | Opnd := OK_Convert_To (Ctyp, Left_Opnd (Opnod)); |
70482933 | 1105 | |
ec2dd67a RD |
1106 | Analyze (Opnd); |
1107 | Set_Etype (Opnd, Ctyp); | |
1108 | Set_Analyzed (Opnd, True); | |
1109 | Set_Left_Opnd (Opnod, Opnd); | |
70482933 | 1110 | |
ec2dd67a | 1111 | Opnd := OK_Convert_To (Ctyp, Right_Opnd (Opnod)); |
70482933 | 1112 | |
ec2dd67a RD |
1113 | Analyze (Opnd); |
1114 | Set_Etype (Opnd, Ctyp); | |
1115 | Set_Analyzed (Opnd, True); | |
1116 | Set_Right_Opnd (Opnod, Opnd); | |
70482933 | 1117 | |
ec2dd67a RD |
1118 | -- The type of the operation changes to the base type of the check |
1119 | -- type, and we reset the overflow check indication, since clearly no | |
1120 | -- overflow is possible now that we are using a double length type. | |
1121 | -- We also set the Analyzed flag to avoid a recursive attempt to | |
1122 | -- expand the node. | |
70482933 | 1123 | |
ec2dd67a RD |
1124 | Set_Etype (Opnod, Base_Type (Ctyp)); |
1125 | Set_Do_Overflow_Check (Opnod, False); | |
1126 | Set_Analyzed (Opnod, True); | |
70482933 | 1127 | |
ec2dd67a | 1128 | -- Now build the outer conversion |
70482933 | 1129 | |
ec2dd67a RD |
1130 | Opnd := OK_Convert_To (Typ, Opnod); |
1131 | Analyze (Opnd); | |
1132 | Set_Etype (Opnd, Typ); | |
fbf5a39b | 1133 | |
ec2dd67a RD |
1134 | -- In the discrete type case, we directly generate the range check |
1135 | -- for the outer operand. This range check will implement the | |
1136 | -- required overflow check. | |
fbf5a39b | 1137 | |
ec2dd67a RD |
1138 | if Is_Discrete_Type (Typ) then |
1139 | Rewrite (N, Opnd); | |
1140 | Generate_Range_Check | |
1141 | (Expression (N), Typ, CE_Overflow_Check_Failed); | |
fbf5a39b | 1142 | |
ec2dd67a RD |
1143 | -- For other types, we enable overflow checking on the conversion, |
1144 | -- after setting the node as analyzed to prevent recursive attempts | |
1145 | -- to expand the conversion node. | |
fbf5a39b | 1146 | |
ec2dd67a RD |
1147 | else |
1148 | Set_Analyzed (Opnd, True); | |
1149 | Enable_Overflow_Check (Opnd); | |
1150 | Rewrite (N, Opnd); | |
1151 | end if; | |
1152 | ||
1153 | exception | |
1154 | when RE_Not_Available => | |
1155 | return; | |
1156 | end; | |
a7f1b24f | 1157 | end Apply_Arithmetic_Overflow_Strict; |
acad3c0a AC |
1158 | |
1159 | ---------------------------------------------------- | |
1160 | -- Apply_Arithmetic_Overflow_Minimized_Eliminated -- | |
1161 | ---------------------------------------------------- | |
1162 | ||
1163 | procedure Apply_Arithmetic_Overflow_Minimized_Eliminated (Op : Node_Id) is | |
1164 | pragma Assert (Is_Signed_Integer_Arithmetic_Op (Op)); | |
acad3c0a AC |
1165 | |
1166 | Loc : constant Source_Ptr := Sloc (Op); | |
1167 | P : constant Node_Id := Parent (Op); | |
1168 | ||
d79059a3 AC |
1169 | LLIB : constant Entity_Id := Base_Type (Standard_Long_Long_Integer); |
1170 | -- Operands and results are of this type when we convert | |
1171 | ||
acad3c0a AC |
1172 | Result_Type : constant Entity_Id := Etype (Op); |
1173 | -- Original result type | |
1174 | ||
15c94a55 | 1175 | Check_Mode : constant Overflow_Mode_Type := Overflow_Check_Mode; |
acad3c0a AC |
1176 | pragma Assert (Check_Mode in Minimized_Or_Eliminated); |
1177 | ||
1178 | Lo, Hi : Uint; | |
1179 | -- Ranges of values for result | |
1180 | ||
1181 | begin | |
1182 | -- Nothing to do if our parent is one of the following: | |
1183 | ||
4b1c4f20 | 1184 | -- Another signed integer arithmetic op |
acad3c0a AC |
1185 | -- A membership operation |
1186 | -- A comparison operation | |
1187 | ||
1188 | -- In all these cases, we will process at the higher level (and then | |
1189 | -- this node will be processed during the downwards recursion that | |
a7f1b24f | 1190 | -- is part of the processing in Minimize_Eliminate_Overflows). |
acad3c0a AC |
1191 | |
1192 | if Is_Signed_Integer_Arithmetic_Op (P) | |
71fb4dc8 AC |
1193 | or else Nkind (P) in N_Membership_Test |
1194 | or else Nkind (P) in N_Op_Compare | |
f6194278 | 1195 | |
f6636994 AC |
1196 | -- This is also true for an alternative in a case expression |
1197 | ||
1198 | or else Nkind (P) = N_Case_Expression_Alternative | |
1199 | ||
1200 | -- This is also true for a range operand in a membership test | |
f6194278 | 1201 | |
71fb4dc8 AC |
1202 | or else (Nkind (P) = N_Range |
1203 | and then Nkind (Parent (P)) in N_Membership_Test) | |
acad3c0a | 1204 | then |
fdc54be6 AC |
1205 | -- If_Expressions and Case_Expressions are treated as arithmetic |
1206 | -- ops, but if they appear in an assignment or similar contexts | |
1207 | -- there is no overflow check that starts from that parent node, | |
1208 | -- so apply check now. | |
1209 | ||
1210 | if Nkind_In (P, N_If_Expression, N_Case_Expression) | |
1211 | and then not Is_Signed_Integer_Arithmetic_Op (Parent (P)) | |
1212 | then | |
1213 | null; | |
1214 | else | |
1215 | return; | |
1216 | end if; | |
acad3c0a AC |
1217 | end if; |
1218 | ||
4b1c4f20 | 1219 | -- Otherwise, we have a top level arithmetic operation node, and this |
5707e389 AC |
1220 | -- is where we commence the special processing for MINIMIZED/ELIMINATED |
1221 | -- modes. This is the case where we tell the machinery not to move into | |
1222 | -- Bignum mode at this top level (of course the top level operation | |
1223 | -- will still be in Bignum mode if either of its operands are of type | |
1224 | -- Bignum). | |
acad3c0a | 1225 | |
a7f1b24f | 1226 | Minimize_Eliminate_Overflows (Op, Lo, Hi, Top_Level => True); |
acad3c0a AC |
1227 | |
1228 | -- That call may but does not necessarily change the result type of Op. | |
1229 | -- It is the job of this routine to undo such changes, so that at the | |
1230 | -- top level, we have the proper type. This "undoing" is a point at | |
1231 | -- which a final overflow check may be applied. | |
1232 | ||
b6b5cca8 AC |
1233 | -- If the result type was not fiddled we are all set. We go to base |
1234 | -- types here because things may have been rewritten to generate the | |
1235 | -- base type of the operand types. | |
acad3c0a | 1236 | |
b6b5cca8 | 1237 | if Base_Type (Etype (Op)) = Base_Type (Result_Type) then |
acad3c0a AC |
1238 | return; |
1239 | ||
1240 | -- Bignum case | |
1241 | ||
d79059a3 | 1242 | elsif Is_RTE (Etype (Op), RE_Bignum) then |
acad3c0a | 1243 | |
456cbfa5 | 1244 | -- We need a sequence that looks like: |
acad3c0a AC |
1245 | |
1246 | -- Rnn : Result_Type; | |
1247 | ||
1248 | -- declare | |
456cbfa5 | 1249 | -- M : Mark_Id := SS_Mark; |
acad3c0a | 1250 | -- begin |
d79059a3 | 1251 | -- Rnn := Long_Long_Integer'Base (From_Bignum (Op)); |
acad3c0a AC |
1252 | -- SS_Release (M); |
1253 | -- end; | |
1254 | ||
1255 | -- This block is inserted (using Insert_Actions), and then the node | |
1256 | -- is replaced with a reference to Rnn. | |
1257 | ||
e645cb39 | 1258 | -- If our parent is a conversion node then there is no point in |
4404c282 | 1259 | -- generating a conversion to Result_Type. Instead, we let the parent |
e645cb39 AC |
1260 | -- handle this. Note that this special case is not just about |
1261 | -- optimization. Consider | |
acad3c0a AC |
1262 | |
1263 | -- A,B,C : Integer; | |
1264 | -- ... | |
d79059a3 | 1265 | -- X := Long_Long_Integer'Base (A * (B ** C)); |
acad3c0a AC |
1266 | |
1267 | -- Now the product may fit in Long_Long_Integer but not in Integer. | |
5707e389 AC |
1268 | -- In MINIMIZED/ELIMINATED mode, we don't want to introduce an |
1269 | -- overflow exception for this intermediate value. | |
acad3c0a AC |
1270 | |
1271 | declare | |
d79059a3 | 1272 | Blk : constant Node_Id := Make_Bignum_Block (Loc); |
acad3c0a AC |
1273 | Rnn : constant Entity_Id := Make_Temporary (Loc, 'R', Op); |
1274 | RHS : Node_Id; | |
1275 | ||
1276 | Rtype : Entity_Id; | |
1277 | ||
1278 | begin | |
1279 | RHS := Convert_From_Bignum (Op); | |
1280 | ||
1281 | if Nkind (P) /= N_Type_Conversion then | |
d79059a3 | 1282 | Convert_To_And_Rewrite (Result_Type, RHS); |
acad3c0a AC |
1283 | Rtype := Result_Type; |
1284 | ||
1285 | -- Interesting question, do we need a check on that conversion | |
1286 | -- operation. Answer, not if we know the result is in range. | |
1287 | -- At the moment we are not taking advantage of this. To be | |
1288 | -- looked at later ??? | |
1289 | ||
1290 | else | |
d79059a3 | 1291 | Rtype := LLIB; |
acad3c0a AC |
1292 | end if; |
1293 | ||
1294 | Insert_Before | |
1295 | (First (Statements (Handled_Statement_Sequence (Blk))), | |
1296 | Make_Assignment_Statement (Loc, | |
1297 | Name => New_Occurrence_Of (Rnn, Loc), | |
1298 | Expression => RHS)); | |
1299 | ||
1300 | Insert_Actions (Op, New_List ( | |
1301 | Make_Object_Declaration (Loc, | |
1302 | Defining_Identifier => Rnn, | |
1303 | Object_Definition => New_Occurrence_Of (Rtype, Loc)), | |
1304 | Blk)); | |
1305 | ||
1306 | Rewrite (Op, New_Occurrence_Of (Rnn, Loc)); | |
1307 | Analyze_And_Resolve (Op); | |
1308 | end; | |
1309 | ||
fdc54be6 | 1310 | -- Here we know the result is Long_Long_Integer'Base, or that it has |
60b68e56 | 1311 | -- been rewritten because the parent operation is a conversion. See |
a7f1b24f | 1312 | -- Apply_Arithmetic_Overflow_Strict.Conversion_Optimization. |
acad3c0a AC |
1313 | |
1314 | else | |
b6b5cca8 AC |
1315 | pragma Assert |
1316 | (Etype (Op) = LLIB or else Nkind (Parent (Op)) = N_Type_Conversion); | |
acad3c0a AC |
1317 | |
1318 | -- All we need to do here is to convert the result to the proper | |
1319 | -- result type. As explained above for the Bignum case, we can | |
1320 | -- omit this if our parent is a type conversion. | |
1321 | ||
1322 | if Nkind (P) /= N_Type_Conversion then | |
1323 | Convert_To_And_Rewrite (Result_Type, Op); | |
1324 | end if; | |
1325 | ||
1326 | Analyze_And_Resolve (Op); | |
1327 | end if; | |
1328 | end Apply_Arithmetic_Overflow_Minimized_Eliminated; | |
70482933 | 1329 | |
70482933 RK |
1330 | ---------------------------- |
1331 | -- Apply_Constraint_Check -- | |
1332 | ---------------------------- | |
1333 | ||
1334 | procedure Apply_Constraint_Check | |
1335 | (N : Node_Id; | |
1336 | Typ : Entity_Id; | |
1337 | No_Sliding : Boolean := False) | |
1338 | is | |
1339 | Desig_Typ : Entity_Id; | |
1340 | ||
1341 | begin | |
48f91b44 RD |
1342 | -- No checks inside a generic (check the instantiations) |
1343 | ||
70482933 RK |
1344 | if Inside_A_Generic then |
1345 | return; | |
48f91b44 | 1346 | end if; |
70482933 | 1347 | |
308e6f3a | 1348 | -- Apply required constraint checks |
48f91b44 RD |
1349 | |
1350 | if Is_Scalar_Type (Typ) then | |
70482933 RK |
1351 | Apply_Scalar_Range_Check (N, Typ); |
1352 | ||
1353 | elsif Is_Array_Type (Typ) then | |
1354 | ||
d8b9660d | 1355 | -- A useful optimization: an aggregate with only an others clause |
c84700e7 ES |
1356 | -- always has the right bounds. |
1357 | ||
1358 | if Nkind (N) = N_Aggregate | |
1359 | and then No (Expressions (N)) | |
1360 | and then Nkind | |
1361 | (First (Choices (First (Component_Associations (N))))) | |
1362 | = N_Others_Choice | |
1363 | then | |
1364 | return; | |
1365 | end if; | |
1366 | ||
70482933 RK |
1367 | if Is_Constrained (Typ) then |
1368 | Apply_Length_Check (N, Typ); | |
1369 | ||
1370 | if No_Sliding then | |
1371 | Apply_Range_Check (N, Typ); | |
1372 | end if; | |
1373 | else | |
1374 | Apply_Range_Check (N, Typ); | |
1375 | end if; | |
1376 | ||
a40ada7e | 1377 | elsif (Is_Record_Type (Typ) or else Is_Private_Type (Typ)) |
70482933 RK |
1378 | and then Has_Discriminants (Base_Type (Typ)) |
1379 | and then Is_Constrained (Typ) | |
1380 | then | |
1381 | Apply_Discriminant_Check (N, Typ); | |
1382 | ||
1383 | elsif Is_Access_Type (Typ) then | |
1384 | ||
1385 | Desig_Typ := Designated_Type (Typ); | |
1386 | ||
1387 | -- No checks necessary if expression statically null | |
1388 | ||
939c12d2 | 1389 | if Known_Null (N) then |
11b4899f JM |
1390 | if Can_Never_Be_Null (Typ) then |
1391 | Install_Null_Excluding_Check (N); | |
1392 | end if; | |
70482933 RK |
1393 | |
1394 | -- No sliding possible on access to arrays | |
1395 | ||
1396 | elsif Is_Array_Type (Desig_Typ) then | |
1397 | if Is_Constrained (Desig_Typ) then | |
1398 | Apply_Length_Check (N, Typ); | |
1399 | end if; | |
1400 | ||
1401 | Apply_Range_Check (N, Typ); | |
1402 | ||
99bba92c AC |
1403 | -- Do not install a discriminant check for a constrained subtype |
1404 | -- created for an unconstrained nominal type because the subtype | |
1405 | -- has the correct constraints by construction. | |
1406 | ||
70482933 | 1407 | elsif Has_Discriminants (Base_Type (Desig_Typ)) |
99bba92c AC |
1408 | and then Is_Constrained (Desig_Typ) |
1409 | and then not Is_Constr_Subt_For_U_Nominal (Desig_Typ) | |
70482933 RK |
1410 | then |
1411 | Apply_Discriminant_Check (N, Typ); | |
1412 | end if; | |
2820d220 | 1413 | |
16b05213 | 1414 | -- Apply the 2005 Null_Excluding check. Note that we do not apply |
11b4899f JM |
1415 | -- this check if the constraint node is illegal, as shown by having |
1416 | -- an error posted. This additional guard prevents cascaded errors | |
1417 | -- and compiler aborts on illegal programs involving Ada 2005 checks. | |
1418 | ||
2820d220 AC |
1419 | if Can_Never_Be_Null (Typ) |
1420 | and then not Can_Never_Be_Null (Etype (N)) | |
11b4899f | 1421 | and then not Error_Posted (N) |
2820d220 AC |
1422 | then |
1423 | Install_Null_Excluding_Check (N); | |
1424 | end if; | |
70482933 RK |
1425 | end if; |
1426 | end Apply_Constraint_Check; | |
1427 | ||
1428 | ------------------------------ | |
1429 | -- Apply_Discriminant_Check -- | |
1430 | ------------------------------ | |
1431 | ||
1432 | procedure Apply_Discriminant_Check | |
1433 | (N : Node_Id; | |
1434 | Typ : Entity_Id; | |
1435 | Lhs : Node_Id := Empty) | |
1436 | is | |
1437 | Loc : constant Source_Ptr := Sloc (N); | |
1438 | Do_Access : constant Boolean := Is_Access_Type (Typ); | |
1439 | S_Typ : Entity_Id := Etype (N); | |
1440 | Cond : Node_Id; | |
1441 | T_Typ : Entity_Id; | |
1442 | ||
438ff97c ES |
1443 | function Denotes_Explicit_Dereference (Obj : Node_Id) return Boolean; |
1444 | -- A heap object with an indefinite subtype is constrained by its | |
1445 | -- initial value, and assigning to it requires a constraint_check. | |
1446 | -- The target may be an explicit dereference, or a renaming of one. | |
1447 | ||
70482933 RK |
1448 | function Is_Aliased_Unconstrained_Component return Boolean; |
1449 | -- It is possible for an aliased component to have a nominal | |
1450 | -- unconstrained subtype (through instantiation). If this is a | |
1451 | -- discriminated component assigned in the expansion of an aggregate | |
1452 | -- in an initialization, the check must be suppressed. This unusual | |
939c12d2 | 1453 | -- situation requires a predicate of its own. |
70482933 | 1454 | |
438ff97c ES |
1455 | ---------------------------------- |
1456 | -- Denotes_Explicit_Dereference -- | |
1457 | ---------------------------------- | |
1458 | ||
1459 | function Denotes_Explicit_Dereference (Obj : Node_Id) return Boolean is | |
1460 | begin | |
1461 | return | |
1462 | Nkind (Obj) = N_Explicit_Dereference | |
1463 | or else | |
1464 | (Is_Entity_Name (Obj) | |
1465 | and then Present (Renamed_Object (Entity (Obj))) | |
e074d476 AC |
1466 | and then Nkind (Renamed_Object (Entity (Obj))) = |
1467 | N_Explicit_Dereference); | |
438ff97c ES |
1468 | end Denotes_Explicit_Dereference; |
1469 | ||
70482933 RK |
1470 | ---------------------------------------- |
1471 | -- Is_Aliased_Unconstrained_Component -- | |
1472 | ---------------------------------------- | |
1473 | ||
1474 | function Is_Aliased_Unconstrained_Component return Boolean is | |
1475 | Comp : Entity_Id; | |
1476 | Pref : Node_Id; | |
1477 | ||
1478 | begin | |
1479 | if Nkind (Lhs) /= N_Selected_Component then | |
1480 | return False; | |
1481 | else | |
1482 | Comp := Entity (Selector_Name (Lhs)); | |
1483 | Pref := Prefix (Lhs); | |
1484 | end if; | |
1485 | ||
1486 | if Ekind (Comp) /= E_Component | |
1487 | or else not Is_Aliased (Comp) | |
1488 | then | |
1489 | return False; | |
1490 | end if; | |
1491 | ||
1492 | return not Comes_From_Source (Pref) | |
1493 | and then In_Instance | |
1494 | and then not Is_Constrained (Etype (Comp)); | |
1495 | end Is_Aliased_Unconstrained_Component; | |
1496 | ||
1497 | -- Start of processing for Apply_Discriminant_Check | |
1498 | ||
1499 | begin | |
1500 | if Do_Access then | |
1501 | T_Typ := Designated_Type (Typ); | |
1502 | else | |
1503 | T_Typ := Typ; | |
1504 | end if; | |
1505 | ||
6ae40af3 ES |
1506 | -- If the expression is a function call that returns a limited object |
1507 | -- it cannot be copied. It is not clear how to perform the proper | |
1508 | -- discriminant check in this case because the discriminant value must | |
1509 | -- be retrieved from the constructed object itself. | |
1510 | ||
1511 | if Nkind (N) = N_Function_Call | |
1512 | and then Is_Limited_Type (Typ) | |
1513 | and then Is_Entity_Name (Name (N)) | |
1514 | and then Returns_By_Ref (Entity (Name (N))) | |
1515 | then | |
1516 | return; | |
1517 | end if; | |
1518 | ||
27bb7941 AC |
1519 | -- Only apply checks when generating code and discriminant checks are |
1520 | -- not suppressed. In GNATprove mode, we do not apply the checks, but we | |
1521 | -- still analyze the expression to possibly issue errors on SPARK code | |
1522 | -- when a run-time error can be detected at compile time. | |
1523 | ||
1524 | if not GNATprove_Mode then | |
1525 | if not Expander_Active | |
1526 | or else Discriminant_Checks_Suppressed (T_Typ) | |
1527 | then | |
1528 | return; | |
1529 | end if; | |
70482933 RK |
1530 | end if; |
1531 | ||
675d6070 TQ |
1532 | -- No discriminant checks necessary for an access when expression is |
1533 | -- statically Null. This is not only an optimization, it is fundamental | |
1534 | -- because otherwise discriminant checks may be generated in init procs | |
1535 | -- for types containing an access to a not-yet-frozen record, causing a | |
1536 | -- deadly forward reference. | |
70482933 | 1537 | |
675d6070 TQ |
1538 | -- Also, if the expression is of an access type whose designated type is |
1539 | -- incomplete, then the access value must be null and we suppress the | |
1540 | -- check. | |
70482933 | 1541 | |
939c12d2 | 1542 | if Known_Null (N) then |
70482933 RK |
1543 | return; |
1544 | ||
1545 | elsif Is_Access_Type (S_Typ) then | |
1546 | S_Typ := Designated_Type (S_Typ); | |
1547 | ||
1548 | if Ekind (S_Typ) = E_Incomplete_Type then | |
1549 | return; | |
1550 | end if; | |
1551 | end if; | |
1552 | ||
c064e066 RD |
1553 | -- If an assignment target is present, then we need to generate the |
1554 | -- actual subtype if the target is a parameter or aliased object with | |
1555 | -- an unconstrained nominal subtype. | |
1556 | ||
1557 | -- Ada 2005 (AI-363): For Ada 2005, we limit the building of the actual | |
1558 | -- subtype to the parameter and dereference cases, since other aliased | |
1559 | -- objects are unconstrained (unless the nominal subtype is explicitly | |
438ff97c | 1560 | -- constrained). |
70482933 RK |
1561 | |
1562 | if Present (Lhs) | |
1563 | and then (Present (Param_Entity (Lhs)) | |
0791fbe9 | 1564 | or else (Ada_Version < Ada_2005 |
c064e066 | 1565 | and then not Is_Constrained (T_Typ) |
70482933 | 1566 | and then Is_Aliased_View (Lhs) |
c064e066 | 1567 | and then not Is_Aliased_Unconstrained_Component) |
0791fbe9 | 1568 | or else (Ada_Version >= Ada_2005 |
c064e066 | 1569 | and then not Is_Constrained (T_Typ) |
438ff97c | 1570 | and then Denotes_Explicit_Dereference (Lhs) |
c064e066 RD |
1571 | and then Nkind (Original_Node (Lhs)) /= |
1572 | N_Function_Call)) | |
70482933 RK |
1573 | then |
1574 | T_Typ := Get_Actual_Subtype (Lhs); | |
1575 | end if; | |
1576 | ||
675d6070 TQ |
1577 | -- Nothing to do if the type is unconstrained (this is the case where |
1578 | -- the actual subtype in the RM sense of N is unconstrained and no check | |
1579 | -- is required). | |
70482933 RK |
1580 | |
1581 | if not Is_Constrained (T_Typ) then | |
1582 | return; | |
d8b9660d ES |
1583 | |
1584 | -- Ada 2005: nothing to do if the type is one for which there is a | |
1585 | -- partial view that is constrained. | |
1586 | ||
0791fbe9 | 1587 | elsif Ada_Version >= Ada_2005 |
0fbcb11c | 1588 | and then Object_Type_Has_Constrained_Partial_View |
414b312e AC |
1589 | (Typ => Base_Type (T_Typ), |
1590 | Scop => Current_Scope) | |
d8b9660d ES |
1591 | then |
1592 | return; | |
70482933 RK |
1593 | end if; |
1594 | ||
5d09245e AC |
1595 | -- Nothing to do if the type is an Unchecked_Union |
1596 | ||
1597 | if Is_Unchecked_Union (Base_Type (T_Typ)) then | |
1598 | return; | |
1599 | end if; | |
1600 | ||
6b6041ec | 1601 | -- Suppress checks if the subtypes are the same. The check must be |
675d6070 TQ |
1602 | -- preserved in an assignment to a formal, because the constraint is |
1603 | -- given by the actual. | |
70482933 RK |
1604 | |
1605 | if Nkind (Original_Node (N)) /= N_Allocator | |
1606 | and then (No (Lhs) | |
9972d439 RD |
1607 | or else not Is_Entity_Name (Lhs) |
1608 | or else No (Param_Entity (Lhs))) | |
70482933 RK |
1609 | then |
1610 | if (Etype (N) = Typ | |
1611 | or else (Do_Access and then Designated_Type (Typ) = S_Typ)) | |
1612 | and then not Is_Aliased_View (Lhs) | |
1613 | then | |
1614 | return; | |
1615 | end if; | |
1616 | ||
675d6070 TQ |
1617 | -- We can also eliminate checks on allocators with a subtype mark that |
1618 | -- coincides with the context type. The context type may be a subtype | |
1619 | -- without a constraint (common case, a generic actual). | |
70482933 RK |
1620 | |
1621 | elsif Nkind (Original_Node (N)) = N_Allocator | |
1622 | and then Is_Entity_Name (Expression (Original_Node (N))) | |
1623 | then | |
1624 | declare | |
fbf5a39b | 1625 | Alloc_Typ : constant Entity_Id := |
15f0f591 | 1626 | Entity (Expression (Original_Node (N))); |
70482933 RK |
1627 | |
1628 | begin | |
1629 | if Alloc_Typ = T_Typ | |
1630 | or else (Nkind (Parent (T_Typ)) = N_Subtype_Declaration | |
1631 | and then Is_Entity_Name ( | |
1632 | Subtype_Indication (Parent (T_Typ))) | |
1633 | and then Alloc_Typ = Base_Type (T_Typ)) | |
1634 | ||
1635 | then | |
1636 | return; | |
1637 | end if; | |
1638 | end; | |
1639 | end if; | |
1640 | ||
675d6070 TQ |
1641 | -- See if we have a case where the types are both constrained, and all |
1642 | -- the constraints are constants. In this case, we can do the check | |
1643 | -- successfully at compile time. | |
70482933 | 1644 | |
6b6041ec | 1645 | -- We skip this check for the case where the node is rewritten as |
c91dbd18 AC |
1646 | -- an allocator, because it already carries the context subtype, |
1647 | -- and extracting the discriminants from the aggregate is messy. | |
70482933 RK |
1648 | |
1649 | if Is_Constrained (S_Typ) | |
1650 | and then Nkind (Original_Node (N)) /= N_Allocator | |
1651 | then | |
1652 | declare | |
1653 | DconT : Elmt_Id; | |
1654 | Discr : Entity_Id; | |
1655 | DconS : Elmt_Id; | |
1656 | ItemS : Node_Id; | |
1657 | ItemT : Node_Id; | |
1658 | ||
1659 | begin | |
1660 | -- S_Typ may not have discriminants in the case where it is a | |
675d6070 | 1661 | -- private type completed by a default discriminated type. In that |
6b6041ec | 1662 | -- case, we need to get the constraints from the underlying type. |
675d6070 TQ |
1663 | -- If the underlying type is unconstrained (i.e. has no default |
1664 | -- discriminants) no check is needed. | |
70482933 RK |
1665 | |
1666 | if Has_Discriminants (S_Typ) then | |
1667 | Discr := First_Discriminant (S_Typ); | |
1668 | DconS := First_Elmt (Discriminant_Constraint (S_Typ)); | |
1669 | ||
1670 | else | |
1671 | Discr := First_Discriminant (Underlying_Type (S_Typ)); | |
1672 | DconS := | |
1673 | First_Elmt | |
1674 | (Discriminant_Constraint (Underlying_Type (S_Typ))); | |
1675 | ||
1676 | if No (DconS) then | |
1677 | return; | |
1678 | end if; | |
65356e64 AC |
1679 | |
1680 | -- A further optimization: if T_Typ is derived from S_Typ | |
1681 | -- without imposing a constraint, no check is needed. | |
1682 | ||
1683 | if Nkind (Original_Node (Parent (T_Typ))) = | |
1684 | N_Full_Type_Declaration | |
1685 | then | |
1686 | declare | |
91b1417d | 1687 | Type_Def : constant Node_Id := |
15f0f591 | 1688 | Type_Definition (Original_Node (Parent (T_Typ))); |
65356e64 AC |
1689 | begin |
1690 | if Nkind (Type_Def) = N_Derived_Type_Definition | |
1691 | and then Is_Entity_Name (Subtype_Indication (Type_Def)) | |
1692 | and then Entity (Subtype_Indication (Type_Def)) = S_Typ | |
1693 | then | |
1694 | return; | |
1695 | end if; | |
1696 | end; | |
1697 | end if; | |
70482933 RK |
1698 | end if; |
1699 | ||
d2a6bd6b AC |
1700 | -- Constraint may appear in full view of type |
1701 | ||
1702 | if Ekind (T_Typ) = E_Private_Subtype | |
1703 | and then Present (Full_View (T_Typ)) | |
1704 | then | |
c91dbd18 | 1705 | DconT := |
d2a6bd6b | 1706 | First_Elmt (Discriminant_Constraint (Full_View (T_Typ))); |
d2a6bd6b | 1707 | else |
c91dbd18 AC |
1708 | DconT := |
1709 | First_Elmt (Discriminant_Constraint (T_Typ)); | |
d2a6bd6b | 1710 | end if; |
70482933 RK |
1711 | |
1712 | while Present (Discr) loop | |
1713 | ItemS := Node (DconS); | |
1714 | ItemT := Node (DconT); | |
1715 | ||
11b4899f JM |
1716 | -- For a discriminated component type constrained by the |
1717 | -- current instance of an enclosing type, there is no | |
1718 | -- applicable discriminant check. | |
1719 | ||
1720 | if Nkind (ItemT) = N_Attribute_Reference | |
1721 | and then Is_Access_Type (Etype (ItemT)) | |
1722 | and then Is_Entity_Name (Prefix (ItemT)) | |
1723 | and then Is_Type (Entity (Prefix (ItemT))) | |
1724 | then | |
1725 | return; | |
1726 | end if; | |
1727 | ||
f2cbd970 JM |
1728 | -- If the expressions for the discriminants are identical |
1729 | -- and it is side-effect free (for now just an entity), | |
1730 | -- this may be a shared constraint, e.g. from a subtype | |
1731 | -- without a constraint introduced as a generic actual. | |
1732 | -- Examine other discriminants if any. | |
1733 | ||
1734 | if ItemS = ItemT | |
1735 | and then Is_Entity_Name (ItemS) | |
1736 | then | |
1737 | null; | |
1738 | ||
1739 | elsif not Is_OK_Static_Expression (ItemS) | |
1740 | or else not Is_OK_Static_Expression (ItemT) | |
1741 | then | |
1742 | exit; | |
70482933 | 1743 | |
f2cbd970 | 1744 | elsif Expr_Value (ItemS) /= Expr_Value (ItemT) then |
70482933 RK |
1745 | if Do_Access then -- needs run-time check. |
1746 | exit; | |
1747 | else | |
1748 | Apply_Compile_Time_Constraint_Error | |
685bc70f | 1749 | (N, "incorrect value for discriminant&??", |
07fc65c4 | 1750 | CE_Discriminant_Check_Failed, Ent => Discr); |
70482933 RK |
1751 | return; |
1752 | end if; | |
1753 | end if; | |
1754 | ||
1755 | Next_Elmt (DconS); | |
1756 | Next_Elmt (DconT); | |
1757 | Next_Discriminant (Discr); | |
1758 | end loop; | |
1759 | ||
1760 | if No (Discr) then | |
1761 | return; | |
1762 | end if; | |
1763 | end; | |
1764 | end if; | |
1765 | ||
27bb7941 AC |
1766 | -- In GNATprove mode, we do not apply the checks |
1767 | ||
1768 | if GNATprove_Mode then | |
1769 | return; | |
1770 | end if; | |
1771 | ||
70482933 RK |
1772 | -- Here we need a discriminant check. First build the expression |
1773 | -- for the comparisons of the discriminants: | |
1774 | ||
1775 | -- (n.disc1 /= typ.disc1) or else | |
1776 | -- (n.disc2 /= typ.disc2) or else | |
1777 | -- ... | |
1778 | -- (n.discn /= typ.discn) | |
1779 | ||
1780 | Cond := Build_Discriminant_Checks (N, T_Typ); | |
1781 | ||
acad3c0a AC |
1782 | -- If Lhs is set and is a parameter, then the condition is guarded by: |
1783 | -- lhs'constrained and then (condition built above) | |
70482933 RK |
1784 | |
1785 | if Present (Param_Entity (Lhs)) then | |
1786 | Cond := | |
1787 | Make_And_Then (Loc, | |
1788 | Left_Opnd => | |
1789 | Make_Attribute_Reference (Loc, | |
1790 | Prefix => New_Occurrence_Of (Param_Entity (Lhs), Loc), | |
1791 | Attribute_Name => Name_Constrained), | |
1792 | Right_Opnd => Cond); | |
1793 | end if; | |
1794 | ||
1795 | if Do_Access then | |
1796 | Cond := Guard_Access (Cond, Loc, N); | |
1797 | end if; | |
1798 | ||
1799 | Insert_Action (N, | |
07fc65c4 GB |
1800 | Make_Raise_Constraint_Error (Loc, |
1801 | Condition => Cond, | |
1802 | Reason => CE_Discriminant_Check_Failed)); | |
70482933 RK |
1803 | end Apply_Discriminant_Check; |
1804 | ||
a91e9ac7 AC |
1805 | ------------------------- |
1806 | -- Apply_Divide_Checks -- | |
1807 | ------------------------- | |
70482933 | 1808 | |
a91e9ac7 | 1809 | procedure Apply_Divide_Checks (N : Node_Id) is |
70482933 RK |
1810 | Loc : constant Source_Ptr := Sloc (N); |
1811 | Typ : constant Entity_Id := Etype (N); | |
1812 | Left : constant Node_Id := Left_Opnd (N); | |
1813 | Right : constant Node_Id := Right_Opnd (N); | |
1814 | ||
15c94a55 | 1815 | Mode : constant Overflow_Mode_Type := Overflow_Check_Mode; |
a91e9ac7 AC |
1816 | -- Current overflow checking mode |
1817 | ||
70482933 RK |
1818 | LLB : Uint; |
1819 | Llo : Uint; | |
1820 | Lhi : Uint; | |
1821 | LOK : Boolean; | |
1822 | Rlo : Uint; | |
1823 | Rhi : Uint; | |
a91e9ac7 | 1824 | ROK : Boolean; |
67ce0d7e RD |
1825 | |
1826 | pragma Warnings (Off, Lhi); | |
1827 | -- Don't actually use this value | |
70482933 RK |
1828 | |
1829 | begin | |
a7f1b24f RD |
1830 | -- If we are operating in MINIMIZED or ELIMINATED mode, and we are |
1831 | -- operating on signed integer types, then the only thing this routine | |
1832 | -- does is to call Apply_Arithmetic_Overflow_Minimized_Eliminated. That | |
1833 | -- procedure will (possibly later on during recursive downward calls), | |
1834 | -- ensure that any needed overflow/division checks are properly applied. | |
a91e9ac7 AC |
1835 | |
1836 | if Mode in Minimized_Or_Eliminated | |
a91e9ac7 AC |
1837 | and then Is_Signed_Integer_Type (Typ) |
1838 | then | |
1839 | Apply_Arithmetic_Overflow_Minimized_Eliminated (N); | |
1840 | return; | |
1841 | end if; | |
1842 | ||
1843 | -- Proceed here in SUPPRESSED or CHECKED modes | |
1844 | ||
4460a9bc | 1845 | if Expander_Active |
2ede092b RD |
1846 | and then not Backend_Divide_Checks_On_Target |
1847 | and then Check_Needed (Right, Division_Check) | |
70482933 | 1848 | then |
c800f862 | 1849 | Determine_Range (Right, ROK, Rlo, Rhi, Assume_Valid => True); |
70482933 | 1850 | |
a91e9ac7 | 1851 | -- Deal with division check |
70482933 | 1852 | |
a91e9ac7 AC |
1853 | if Do_Division_Check (N) |
1854 | and then not Division_Checks_Suppressed (Typ) | |
1855 | then | |
1856 | Apply_Division_Check (N, Rlo, Rhi, ROK); | |
70482933 RK |
1857 | end if; |
1858 | ||
a91e9ac7 AC |
1859 | -- Deal with overflow check |
1860 | ||
a7f1b24f RD |
1861 | if Do_Overflow_Check (N) |
1862 | and then not Overflow_Checks_Suppressed (Etype (N)) | |
1863 | then | |
b7c874a7 AC |
1864 | Set_Do_Overflow_Check (N, False); |
1865 | ||
a91e9ac7 AC |
1866 | -- Test for extremely annoying case of xxx'First divided by -1 |
1867 | -- for division of signed integer types (only overflow case). | |
70482933 | 1868 | |
70482933 RK |
1869 | if Nkind (N) = N_Op_Divide |
1870 | and then Is_Signed_Integer_Type (Typ) | |
1871 | then | |
c800f862 | 1872 | Determine_Range (Left, LOK, Llo, Lhi, Assume_Valid => True); |
70482933 RK |
1873 | LLB := Expr_Value (Type_Low_Bound (Base_Type (Typ))); |
1874 | ||
1875 | if ((not ROK) or else (Rlo <= (-1) and then (-1) <= Rhi)) | |
a91e9ac7 AC |
1876 | and then |
1877 | ((not LOK) or else (Llo = LLB)) | |
70482933 | 1878 | then |
a8697b27 EB |
1879 | -- Ensure that expressions are not evaluated twice (once |
1880 | -- for their runtime checks and once for their regular | |
1881 | -- computation). | |
1882 | ||
1883 | Force_Evaluation (Left, Mode => Strict); | |
1884 | Force_Evaluation (Right, Mode => Strict); | |
1885 | ||
70482933 RK |
1886 | Insert_Action (N, |
1887 | Make_Raise_Constraint_Error (Loc, | |
1888 | Condition => | |
1889 | Make_And_Then (Loc, | |
a91e9ac7 AC |
1890 | Left_Opnd => |
1891 | Make_Op_Eq (Loc, | |
1892 | Left_Opnd => | |
1893 | Duplicate_Subexpr_Move_Checks (Left), | |
1894 | Right_Opnd => Make_Integer_Literal (Loc, LLB)), | |
70482933 | 1895 | |
a91e9ac7 AC |
1896 | Right_Opnd => |
1897 | Make_Op_Eq (Loc, | |
1898 | Left_Opnd => Duplicate_Subexpr (Right), | |
1899 | Right_Opnd => Make_Integer_Literal (Loc, -1))), | |
70482933 | 1900 | |
07fc65c4 | 1901 | Reason => CE_Overflow_Check_Failed)); |
70482933 RK |
1902 | end if; |
1903 | end if; | |
1904 | end if; | |
1905 | end if; | |
a91e9ac7 AC |
1906 | end Apply_Divide_Checks; |
1907 | ||
1908 | -------------------------- | |
1909 | -- Apply_Division_Check -- | |
1910 | -------------------------- | |
1911 | ||
1912 | procedure Apply_Division_Check | |
1913 | (N : Node_Id; | |
1914 | Rlo : Uint; | |
1915 | Rhi : Uint; | |
1916 | ROK : Boolean) | |
1917 | is | |
1918 | pragma Assert (Do_Division_Check (N)); | |
1919 | ||
1920 | Loc : constant Source_Ptr := Sloc (N); | |
61770974 HK |
1921 | Right : constant Node_Id := Right_Opnd (N); |
1922 | Opnd : Node_Id; | |
a91e9ac7 AC |
1923 | |
1924 | begin | |
4460a9bc | 1925 | if Expander_Active |
a91e9ac7 AC |
1926 | and then not Backend_Divide_Checks_On_Target |
1927 | and then Check_Needed (Right, Division_Check) | |
a91e9ac7 | 1928 | |
61770974 HK |
1929 | -- See if division by zero possible, and if so generate test. This |
1930 | -- part of the test is not controlled by the -gnato switch, since it | |
1931 | -- is a Division_Check and not an Overflow_Check. | |
b7c874a7 | 1932 | |
61770974 HK |
1933 | and then Do_Division_Check (N) |
1934 | then | |
1935 | Set_Do_Division_Check (N, False); | |
ed170742 | 1936 | |
61770974 HK |
1937 | if (not ROK) or else (Rlo <= 0 and then 0 <= Rhi) then |
1938 | if Is_Floating_Point_Type (Etype (N)) then | |
1939 | Opnd := Make_Real_Literal (Loc, Ureal_0); | |
1940 | else | |
1941 | Opnd := Make_Integer_Literal (Loc, 0); | |
a91e9ac7 | 1942 | end if; |
61770974 HK |
1943 | |
1944 | Insert_Action (N, | |
1945 | Make_Raise_Constraint_Error (Loc, | |
1946 | Condition => | |
1947 | Make_Op_Eq (Loc, | |
1948 | Left_Opnd => Duplicate_Subexpr_Move_Checks (Right), | |
1949 | Right_Opnd => Opnd), | |
1950 | Reason => CE_Divide_By_Zero)); | |
a91e9ac7 AC |
1951 | end if; |
1952 | end if; | |
1953 | end Apply_Division_Check; | |
70482933 | 1954 | |
7324bf49 AC |
1955 | ---------------------------------- |
1956 | -- Apply_Float_Conversion_Check -- | |
1957 | ---------------------------------- | |
1958 | ||
675d6070 TQ |
1959 | -- Let F and I be the source and target types of the conversion. The RM |
1960 | -- specifies that a floating-point value X is rounded to the nearest | |
1961 | -- integer, with halfway cases being rounded away from zero. The rounded | |
1962 | -- value of X is checked against I'Range. | |
1963 | ||
1964 | -- The catch in the above paragraph is that there is no good way to know | |
1965 | -- whether the round-to-integer operation resulted in overflow. A remedy is | |
1966 | -- to perform a range check in the floating-point domain instead, however: | |
7324bf49 | 1967 | |
7324bf49 | 1968 | -- (1) The bounds may not be known at compile time |
939c12d2 | 1969 | -- (2) The check must take into account rounding or truncation. |
7324bf49 | 1970 | -- (3) The range of type I may not be exactly representable in F. |
939c12d2 RD |
1971 | -- (4) For the rounding case, The end-points I'First - 0.5 and |
1972 | -- I'Last + 0.5 may or may not be in range, depending on the | |
1973 | -- sign of I'First and I'Last. | |
7324bf49 AC |
1974 | -- (5) X may be a NaN, which will fail any comparison |
1975 | ||
939c12d2 | 1976 | -- The following steps correctly convert X with rounding: |
675d6070 | 1977 | |
7324bf49 AC |
1978 | -- (1) If either I'First or I'Last is not known at compile time, use |
1979 | -- I'Base instead of I in the next three steps and perform a | |
1980 | -- regular range check against I'Range after conversion. | |
1981 | -- (2) If I'First - 0.5 is representable in F then let Lo be that | |
1982 | -- value and define Lo_OK as (I'First > 0). Otherwise, let Lo be | |
939c12d2 RD |
1983 | -- F'Machine (I'First) and let Lo_OK be (Lo >= I'First). |
1984 | -- In other words, take one of the closest floating-point numbers | |
1985 | -- (which is an integer value) to I'First, and see if it is in | |
1986 | -- range or not. | |
7324bf49 AC |
1987 | -- (3) If I'Last + 0.5 is representable in F then let Hi be that value |
1988 | -- and define Hi_OK as (I'Last < 0). Otherwise, let Hi be | |
939c12d2 | 1989 | -- F'Machine (I'Last) and let Hi_OK be (Hi <= I'Last). |
7324bf49 AC |
1990 | -- (4) Raise CE when (Lo_OK and X < Lo) or (not Lo_OK and X <= Lo) |
1991 | -- or (Hi_OK and X > Hi) or (not Hi_OK and X >= Hi) | |
1992 | ||
939c12d2 RD |
1993 | -- For the truncating case, replace steps (2) and (3) as follows: |
1994 | -- (2) If I'First > 0, then let Lo be F'Pred (I'First) and let Lo_OK | |
1995 | -- be False. Otherwise, let Lo be F'Succ (I'First - 1) and let | |
1996 | -- Lo_OK be True. | |
1997 | -- (3) If I'Last < 0, then let Hi be F'Succ (I'Last) and let Hi_OK | |
1998 | -- be False. Otherwise let Hi be F'Pred (I'Last + 1) and let | |
1197ddb1 | 1999 | -- Hi_OK be True. |
939c12d2 | 2000 | |
7324bf49 AC |
2001 | procedure Apply_Float_Conversion_Check |
2002 | (Ck_Node : Node_Id; | |
2003 | Target_Typ : Entity_Id) | |
2004 | is | |
675d6070 TQ |
2005 | LB : constant Node_Id := Type_Low_Bound (Target_Typ); |
2006 | HB : constant Node_Id := Type_High_Bound (Target_Typ); | |
7324bf49 AC |
2007 | Loc : constant Source_Ptr := Sloc (Ck_Node); |
2008 | Expr_Type : constant Entity_Id := Base_Type (Etype (Ck_Node)); | |
675d6070 | 2009 | Target_Base : constant Entity_Id := |
15f0f591 | 2010 | Implementation_Base_Type (Target_Typ); |
675d6070 | 2011 | |
939c12d2 RD |
2012 | Par : constant Node_Id := Parent (Ck_Node); |
2013 | pragma Assert (Nkind (Par) = N_Type_Conversion); | |
2014 | -- Parent of check node, must be a type conversion | |
2015 | ||
2016 | Truncate : constant Boolean := Float_Truncate (Par); | |
2017 | Max_Bound : constant Uint := | |
15f0f591 AC |
2018 | UI_Expon |
2019 | (Machine_Radix_Value (Expr_Type), | |
2020 | Machine_Mantissa_Value (Expr_Type) - 1) - 1; | |
939c12d2 | 2021 | |
7324bf49 AC |
2022 | -- Largest bound, so bound plus or minus half is a machine number of F |
2023 | ||
675d6070 TQ |
2024 | Ifirst, Ilast : Uint; |
2025 | -- Bounds of integer type | |
2026 | ||
2027 | Lo, Hi : Ureal; | |
2028 | -- Bounds to check in floating-point domain | |
7324bf49 | 2029 | |
675d6070 TQ |
2030 | Lo_OK, Hi_OK : Boolean; |
2031 | -- True iff Lo resp. Hi belongs to I'Range | |
7324bf49 | 2032 | |
675d6070 TQ |
2033 | Lo_Chk, Hi_Chk : Node_Id; |
2034 | -- Expressions that are False iff check fails | |
2035 | ||
2036 | Reason : RT_Exception_Code; | |
7324bf49 AC |
2037 | |
2038 | begin | |
b5bdffcc AC |
2039 | -- We do not need checks if we are not generating code (i.e. the full |
2040 | -- expander is not active). In SPARK mode, we specifically don't want | |
2041 | -- the frontend to expand these checks, which are dealt with directly | |
2042 | -- in the formal verification backend. | |
2043 | ||
4460a9bc | 2044 | if not Expander_Active then |
b5bdffcc AC |
2045 | return; |
2046 | end if; | |
2047 | ||
68c8d72a EB |
2048 | -- Here we will generate an explicit range check, so we don't want to |
2049 | -- set the Do_Range check flag, since the range check is taken care of | |
2050 | -- by the code we will generate. | |
2051 | ||
2052 | Set_Do_Range_Check (Ck_Node, False); | |
2053 | ||
7324bf49 AC |
2054 | if not Compile_Time_Known_Value (LB) |
2055 | or not Compile_Time_Known_Value (HB) | |
2056 | then | |
2057 | declare | |
675d6070 TQ |
2058 | -- First check that the value falls in the range of the base type, |
2059 | -- to prevent overflow during conversion and then perform a | |
2060 | -- regular range check against the (dynamic) bounds. | |
7324bf49 | 2061 | |
7324bf49 | 2062 | pragma Assert (Target_Base /= Target_Typ); |
7324bf49 | 2063 | |
191fcb3a | 2064 | Temp : constant Entity_Id := Make_Temporary (Loc, 'T', Par); |
7324bf49 AC |
2065 | |
2066 | begin | |
2067 | Apply_Float_Conversion_Check (Ck_Node, Target_Base); | |
2068 | Set_Etype (Temp, Target_Base); | |
2069 | ||
ba58b776 GD |
2070 | -- Note: Previously the declaration was inserted above the parent |
2071 | -- of the conversion, apparently as a small optimization for the | |
2072 | -- subequent traversal in Insert_Actions. Unfortunately a similar | |
2073 | -- optimization takes place in Insert_Actions, assuming that the | |
2074 | -- insertion point must be above the expression that creates | |
2075 | -- actions. This is not correct in the presence of conditional | |
2076 | -- expressions, where the insertion must be in the list of actions | |
2077 | -- attached to the current alternative. | |
90393d3c ES |
2078 | |
2079 | Insert_Action (Par, | |
7324bf49 AC |
2080 | Make_Object_Declaration (Loc, |
2081 | Defining_Identifier => Temp, | |
2082 | Object_Definition => New_Occurrence_Of (Target_Typ, Loc), | |
2083 | Expression => New_Copy_Tree (Par)), | |
2084 | Suppress => All_Checks); | |
2085 | ||
2086 | Insert_Action (Par, | |
2087 | Make_Raise_Constraint_Error (Loc, | |
2088 | Condition => | |
2089 | Make_Not_In (Loc, | |
2090 | Left_Opnd => New_Occurrence_Of (Temp, Loc), | |
2091 | Right_Opnd => New_Occurrence_Of (Target_Typ, Loc)), | |
2092 | Reason => CE_Range_Check_Failed)); | |
2093 | Rewrite (Par, New_Occurrence_Of (Temp, Loc)); | |
2094 | ||
2095 | return; | |
2096 | end; | |
2097 | end if; | |
2098 | ||
44114dff | 2099 | -- Get the (static) bounds of the target type |
7324bf49 AC |
2100 | |
2101 | Ifirst := Expr_Value (LB); | |
2102 | Ilast := Expr_Value (HB); | |
2103 | ||
44114dff ES |
2104 | -- A simple optimization: if the expression is a universal literal, |
2105 | -- we can do the comparison with the bounds and the conversion to | |
2106 | -- an integer type statically. The range checks are unchanged. | |
2107 | ||
2108 | if Nkind (Ck_Node) = N_Real_Literal | |
2109 | and then Etype (Ck_Node) = Universal_Real | |
2110 | and then Is_Integer_Type (Target_Typ) | |
44114dff ES |
2111 | then |
2112 | declare | |
2113 | Int_Val : constant Uint := UR_To_Uint (Realval (Ck_Node)); | |
2114 | ||
2115 | begin | |
2116 | if Int_Val <= Ilast and then Int_Val >= Ifirst then | |
2117 | ||
6f2b033b | 2118 | -- Conversion is safe |
44114dff ES |
2119 | |
2120 | Rewrite (Parent (Ck_Node), | |
2121 | Make_Integer_Literal (Loc, UI_To_Int (Int_Val))); | |
2122 | Analyze_And_Resolve (Parent (Ck_Node), Target_Typ); | |
2123 | return; | |
2124 | end if; | |
2125 | end; | |
2126 | end if; | |
2127 | ||
7324bf49 AC |
2128 | -- Check against lower bound |
2129 | ||
939c12d2 RD |
2130 | if Truncate and then Ifirst > 0 then |
2131 | Lo := Pred (Expr_Type, UR_From_Uint (Ifirst)); | |
2132 | Lo_OK := False; | |
2133 | ||
2134 | elsif Truncate then | |
2135 | Lo := Succ (Expr_Type, UR_From_Uint (Ifirst - 1)); | |
2136 | Lo_OK := True; | |
2137 | ||
2138 | elsif abs (Ifirst) < Max_Bound then | |
7324bf49 AC |
2139 | Lo := UR_From_Uint (Ifirst) - Ureal_Half; |
2140 | Lo_OK := (Ifirst > 0); | |
939c12d2 | 2141 | |
7324bf49 AC |
2142 | else |
2143 | Lo := Machine (Expr_Type, UR_From_Uint (Ifirst), Round_Even, Ck_Node); | |
2144 | Lo_OK := (Lo >= UR_From_Uint (Ifirst)); | |
2145 | end if; | |
2146 | ||
2147 | if Lo_OK then | |
2148 | ||
2149 | -- Lo_Chk := (X >= Lo) | |
2150 | ||
2151 | Lo_Chk := Make_Op_Ge (Loc, | |
2152 | Left_Opnd => Duplicate_Subexpr_No_Checks (Ck_Node), | |
2153 | Right_Opnd => Make_Real_Literal (Loc, Lo)); | |
2154 | ||
2155 | else | |
2156 | -- Lo_Chk := (X > Lo) | |
2157 | ||
2158 | Lo_Chk := Make_Op_Gt (Loc, | |
2159 | Left_Opnd => Duplicate_Subexpr_No_Checks (Ck_Node), | |
2160 | Right_Opnd => Make_Real_Literal (Loc, Lo)); | |
2161 | end if; | |
2162 | ||
2163 | -- Check against higher bound | |
2164 | ||
939c12d2 RD |
2165 | if Truncate and then Ilast < 0 then |
2166 | Hi := Succ (Expr_Type, UR_From_Uint (Ilast)); | |
c2db4b32 | 2167 | Hi_OK := False; |
939c12d2 RD |
2168 | |
2169 | elsif Truncate then | |
2170 | Hi := Pred (Expr_Type, UR_From_Uint (Ilast + 1)); | |
2171 | Hi_OK := True; | |
2172 | ||
2173 | elsif abs (Ilast) < Max_Bound then | |
7324bf49 AC |
2174 | Hi := UR_From_Uint (Ilast) + Ureal_Half; |
2175 | Hi_OK := (Ilast < 0); | |
2176 | else | |
2177 | Hi := Machine (Expr_Type, UR_From_Uint (Ilast), Round_Even, Ck_Node); | |
2178 | Hi_OK := (Hi <= UR_From_Uint (Ilast)); | |
2179 | end if; | |
2180 | ||
2181 | if Hi_OK then | |
2182 | ||
2183 | -- Hi_Chk := (X <= Hi) | |
2184 | ||
2185 | Hi_Chk := Make_Op_Le (Loc, | |
2186 | Left_Opnd => Duplicate_Subexpr_No_Checks (Ck_Node), | |
2187 | Right_Opnd => Make_Real_Literal (Loc, Hi)); | |
2188 | ||
2189 | else | |
2190 | -- Hi_Chk := (X < Hi) | |
2191 | ||
2192 | Hi_Chk := Make_Op_Lt (Loc, | |
2193 | Left_Opnd => Duplicate_Subexpr_No_Checks (Ck_Node), | |
2194 | Right_Opnd => Make_Real_Literal (Loc, Hi)); | |
2195 | end if; | |
2196 | ||
675d6070 TQ |
2197 | -- If the bounds of the target type are the same as those of the base |
2198 | -- type, the check is an overflow check as a range check is not | |
2199 | -- performed in these cases. | |
7324bf49 AC |
2200 | |
2201 | if Expr_Value (Type_Low_Bound (Target_Base)) = Ifirst | |
2202 | and then Expr_Value (Type_High_Bound (Target_Base)) = Ilast | |
2203 | then | |
2204 | Reason := CE_Overflow_Check_Failed; | |
2205 | else | |
2206 | Reason := CE_Range_Check_Failed; | |
2207 | end if; | |
2208 | ||
2209 | -- Raise CE if either conditions does not hold | |
2210 | ||
2211 | Insert_Action (Ck_Node, | |
2212 | Make_Raise_Constraint_Error (Loc, | |
d8b9660d | 2213 | Condition => Make_Op_Not (Loc, Make_And_Then (Loc, Lo_Chk, Hi_Chk)), |
7324bf49 AC |
2214 | Reason => Reason)); |
2215 | end Apply_Float_Conversion_Check; | |
2216 | ||
70482933 RK |
2217 | ------------------------ |
2218 | -- Apply_Length_Check -- | |
2219 | ------------------------ | |
2220 | ||
2221 | procedure Apply_Length_Check | |
2222 | (Ck_Node : Node_Id; | |
2223 | Target_Typ : Entity_Id; | |
2224 | Source_Typ : Entity_Id := Empty) | |
2225 | is | |
2226 | begin | |
2227 | Apply_Selected_Length_Checks | |
2228 | (Ck_Node, Target_Typ, Source_Typ, Do_Static => False); | |
2229 | end Apply_Length_Check; | |
2230 | ||
5f49133f AC |
2231 | ------------------------------------- |
2232 | -- Apply_Parameter_Aliasing_Checks -- | |
2233 | ------------------------------------- | |
0ea55619 | 2234 | |
5f49133f AC |
2235 | procedure Apply_Parameter_Aliasing_Checks |
2236 | (Call : Node_Id; | |
2237 | Subp : Entity_Id) | |
2238 | is | |
baed70ac AC |
2239 | Loc : constant Source_Ptr := Sloc (Call); |
2240 | ||
5f49133f AC |
2241 | function May_Cause_Aliasing |
2242 | (Formal_1 : Entity_Id; | |
2243 | Formal_2 : Entity_Id) return Boolean; | |
2244 | -- Determine whether two formal parameters can alias each other | |
2245 | -- depending on their modes. | |
2246 | ||
2247 | function Original_Actual (N : Node_Id) return Node_Id; | |
2248 | -- The expander may replace an actual with a temporary for the sake of | |
2249 | -- side effect removal. The temporary may hide a potential aliasing as | |
2250 | -- it does not share the address of the actual. This routine attempts | |
2251 | -- to retrieve the original actual. | |
2252 | ||
baed70ac AC |
2253 | procedure Overlap_Check |
2254 | (Actual_1 : Node_Id; | |
2255 | Actual_2 : Node_Id; | |
2256 | Formal_1 : Entity_Id; | |
2257 | Formal_2 : Entity_Id; | |
2258 | Check : in out Node_Id); | |
2259 | -- Create a check to determine whether Actual_1 overlaps with Actual_2. | |
2260 | -- If detailed exception messages are enabled, the check is augmented to | |
2261 | -- provide information about the names of the corresponding formals. See | |
2262 | -- the body for details. Actual_1 and Actual_2 denote the two actuals to | |
2263 | -- be tested. Formal_1 and Formal_2 denote the corresponding formals. | |
2264 | -- Check contains all and-ed simple tests generated so far or remains | |
2265 | -- unchanged in the case of detailed exception messaged. | |
2266 | ||
5f49133f AC |
2267 | ------------------------ |
2268 | -- May_Cause_Aliasing -- | |
2269 | ------------------------ | |
0ea55619 | 2270 | |
5f49133f | 2271 | function May_Cause_Aliasing |
e8dde875 | 2272 | (Formal_1 : Entity_Id; |
5f49133f AC |
2273 | Formal_2 : Entity_Id) return Boolean |
2274 | is | |
2275 | begin | |
2276 | -- The following combination cannot lead to aliasing | |
2277 | ||
2278 | -- Formal 1 Formal 2 | |
2279 | -- IN IN | |
2280 | ||
2281 | if Ekind (Formal_1) = E_In_Parameter | |
9a6dc470 RD |
2282 | and then |
2283 | Ekind (Formal_2) = E_In_Parameter | |
5f49133f AC |
2284 | then |
2285 | return False; | |
2286 | ||
2287 | -- The following combinations may lead to aliasing | |
2288 | ||
2289 | -- Formal 1 Formal 2 | |
2290 | -- IN OUT | |
2291 | -- IN IN OUT | |
2292 | -- OUT IN | |
2293 | -- OUT IN OUT | |
2294 | -- OUT OUT | |
2295 | ||
2296 | else | |
2297 | return True; | |
2298 | end if; | |
2299 | end May_Cause_Aliasing; | |
2300 | ||
2301 | --------------------- | |
2302 | -- Original_Actual -- | |
2303 | --------------------- | |
2304 | ||
2305 | function Original_Actual (N : Node_Id) return Node_Id is | |
2306 | begin | |
2307 | if Nkind (N) = N_Type_Conversion then | |
2308 | return Expression (N); | |
2309 | ||
2310 | -- The expander created a temporary to capture the result of a type | |
2311 | -- conversion where the expression is the real actual. | |
2312 | ||
2313 | elsif Nkind (N) = N_Identifier | |
2314 | and then Present (Original_Node (N)) | |
2315 | and then Nkind (Original_Node (N)) = N_Type_Conversion | |
2316 | then | |
2317 | return Expression (Original_Node (N)); | |
2318 | end if; | |
2319 | ||
2320 | return N; | |
2321 | end Original_Actual; | |
2322 | ||
baed70ac AC |
2323 | ------------------- |
2324 | -- Overlap_Check -- | |
2325 | ------------------- | |
2326 | ||
2327 | procedure Overlap_Check | |
2328 | (Actual_1 : Node_Id; | |
2329 | Actual_2 : Node_Id; | |
2330 | Formal_1 : Entity_Id; | |
2331 | Formal_2 : Entity_Id; | |
2332 | Check : in out Node_Id) | |
2333 | is | |
f7ea2603 RD |
2334 | Cond : Node_Id; |
2335 | ID_Casing : constant Casing_Type := | |
2336 | Identifier_Casing (Source_Index (Current_Sem_Unit)); | |
baed70ac AC |
2337 | |
2338 | begin | |
2339 | -- Generate: | |
2340 | -- Actual_1'Overlaps_Storage (Actual_2) | |
2341 | ||
2342 | Cond := | |
2343 | Make_Attribute_Reference (Loc, | |
2344 | Prefix => New_Copy_Tree (Original_Actual (Actual_1)), | |
2345 | Attribute_Name => Name_Overlaps_Storage, | |
2346 | Expressions => | |
2347 | New_List (New_Copy_Tree (Original_Actual (Actual_2)))); | |
2348 | ||
2349 | -- Generate the following check when detailed exception messages are | |
2350 | -- enabled: | |
2351 | ||
2352 | -- if Actual_1'Overlaps_Storage (Actual_2) then | |
2353 | -- raise Program_Error with <detailed message>; | |
2354 | -- end if; | |
2355 | ||
2356 | if Exception_Extra_Info then | |
2357 | Start_String; | |
2358 | ||
2359 | -- Do not generate location information for internal calls | |
2360 | ||
2361 | if Comes_From_Source (Call) then | |
2362 | Store_String_Chars (Build_Location_String (Loc)); | |
2363 | Store_String_Char (' '); | |
2364 | end if; | |
2365 | ||
2366 | Store_String_Chars ("aliased parameters, actuals for """); | |
f7ea2603 RD |
2367 | |
2368 | Get_Name_String (Chars (Formal_1)); | |
2369 | Set_Casing (ID_Casing); | |
2370 | Store_String_Chars (Name_Buffer (1 .. Name_Len)); | |
2371 | ||
baed70ac | 2372 | Store_String_Chars (""" and """); |
f7ea2603 RD |
2373 | |
2374 | Get_Name_String (Chars (Formal_2)); | |
2375 | Set_Casing (ID_Casing); | |
2376 | Store_String_Chars (Name_Buffer (1 .. Name_Len)); | |
2377 | ||
baed70ac AC |
2378 | Store_String_Chars (""" overlap"); |
2379 | ||
2380 | Insert_Action (Call, | |
2381 | Make_If_Statement (Loc, | |
2382 | Condition => Cond, | |
2383 | Then_Statements => New_List ( | |
2384 | Make_Raise_Statement (Loc, | |
2385 | Name => | |
e4494292 | 2386 | New_Occurrence_Of (Standard_Program_Error, Loc), |
baed70ac AC |
2387 | Expression => Make_String_Literal (Loc, End_String))))); |
2388 | ||
2389 | -- Create a sequence of overlapping checks by and-ing them all | |
2390 | -- together. | |
2391 | ||
2392 | else | |
2393 | if No (Check) then | |
2394 | Check := Cond; | |
2395 | else | |
2396 | Check := | |
2397 | Make_And_Then (Loc, | |
2398 | Left_Opnd => Check, | |
2399 | Right_Opnd => Cond); | |
2400 | end if; | |
2401 | end if; | |
2402 | end Overlap_Check; | |
2403 | ||
5f49133f AC |
2404 | -- Local variables |
2405 | ||
b4213ffd AC |
2406 | Actual_1 : Node_Id; |
2407 | Actual_2 : Node_Id; | |
2408 | Check : Node_Id; | |
2409 | Formal_1 : Entity_Id; | |
2410 | Formal_2 : Entity_Id; | |
2411 | Orig_Act_1 : Node_Id; | |
2412 | Orig_Act_2 : Node_Id; | |
5f49133f AC |
2413 | |
2414 | -- Start of processing for Apply_Parameter_Aliasing_Checks | |
2415 | ||
2416 | begin | |
baed70ac | 2417 | Check := Empty; |
5f49133f AC |
2418 | |
2419 | Actual_1 := First_Actual (Call); | |
2420 | Formal_1 := First_Formal (Subp); | |
2421 | while Present (Actual_1) and then Present (Formal_1) loop | |
b4213ffd | 2422 | Orig_Act_1 := Original_Actual (Actual_1); |
5f49133f AC |
2423 | |
2424 | -- Ensure that the actual is an object that is not passed by value. | |
2425 | -- Elementary types are always passed by value, therefore actuals of | |
5904016a AC |
2426 | -- such types cannot lead to aliasing. An aggregate is an object in |
2427 | -- Ada 2012, but an actual that is an aggregate cannot overlap with | |
b3143037 AC |
2428 | -- another actual. A type that is By_Reference (such as an array of |
2429 | -- controlled types) is not subject to the check because any update | |
2430 | -- will be done in place and a subsequent read will always see the | |
2431 | -- correct value, see RM 6.2 (12/3). | |
5f49133f | 2432 | |
b4213ffd AC |
2433 | if Nkind (Orig_Act_1) = N_Aggregate |
2434 | or else (Nkind (Orig_Act_1) = N_Qualified_Expression | |
2435 | and then Nkind (Expression (Orig_Act_1)) = N_Aggregate) | |
5904016a AC |
2436 | then |
2437 | null; | |
2438 | ||
b4213ffd AC |
2439 | elsif Is_Object_Reference (Orig_Act_1) |
2440 | and then not Is_Elementary_Type (Etype (Orig_Act_1)) | |
2441 | and then not Is_By_Reference_Type (Etype (Orig_Act_1)) | |
5f49133f AC |
2442 | then |
2443 | Actual_2 := Next_Actual (Actual_1); | |
2444 | Formal_2 := Next_Formal (Formal_1); | |
2445 | while Present (Actual_2) and then Present (Formal_2) loop | |
b4213ffd | 2446 | Orig_Act_2 := Original_Actual (Actual_2); |
5f49133f AC |
2447 | |
2448 | -- The other actual we are testing against must also denote | |
2449 | -- a non pass-by-value object. Generate the check only when | |
2450 | -- the mode of the two formals may lead to aliasing. | |
2451 | ||
b4213ffd AC |
2452 | if Is_Object_Reference (Orig_Act_2) |
2453 | and then not Is_Elementary_Type (Etype (Orig_Act_2)) | |
5f49133f AC |
2454 | and then May_Cause_Aliasing (Formal_1, Formal_2) |
2455 | then | |
9313a26a AC |
2456 | Remove_Side_Effects (Actual_1); |
2457 | Remove_Side_Effects (Actual_2); | |
2458 | ||
baed70ac AC |
2459 | Overlap_Check |
2460 | (Actual_1 => Actual_1, | |
2461 | Actual_2 => Actual_2, | |
2462 | Formal_1 => Formal_1, | |
2463 | Formal_2 => Formal_2, | |
2464 | Check => Check); | |
5f49133f AC |
2465 | end if; |
2466 | ||
2467 | Next_Actual (Actual_2); | |
2468 | Next_Formal (Formal_2); | |
2469 | end loop; | |
2470 | end if; | |
2471 | ||
2472 | Next_Actual (Actual_1); | |
2473 | Next_Formal (Formal_1); | |
2474 | end loop; | |
2475 | ||
baed70ac | 2476 | -- Place a simple check right before the call |
5f49133f | 2477 | |
baed70ac | 2478 | if Present (Check) and then not Exception_Extra_Info then |
5f49133f AC |
2479 | Insert_Action (Call, |
2480 | Make_Raise_Program_Error (Loc, | |
baed70ac AC |
2481 | Condition => Check, |
2482 | Reason => PE_Aliased_Parameters)); | |
5f49133f AC |
2483 | end if; |
2484 | end Apply_Parameter_Aliasing_Checks; | |
2485 | ||
2486 | ------------------------------------- | |
2487 | -- Apply_Parameter_Validity_Checks -- | |
2488 | ------------------------------------- | |
2489 | ||
2490 | procedure Apply_Parameter_Validity_Checks (Subp : Entity_Id) is | |
2491 | Subp_Decl : Node_Id; | |
0ea55619 | 2492 | |
e8dde875 | 2493 | procedure Add_Validity_Check |
c9d70ab1 AC |
2494 | (Formal : Entity_Id; |
2495 | Prag_Nam : Name_Id; | |
e8dde875 | 2496 | For_Result : Boolean := False); |
31fde973 | 2497 | -- Add a single 'Valid[_Scalars] check which verifies the initialization |
c9d70ab1 | 2498 | -- of Formal. Prag_Nam denotes the pre or post condition pragma name. |
e8dde875 | 2499 | -- Set flag For_Result when to verify the result of a function. |
0ea55619 | 2500 | |
0ea55619 AC |
2501 | ------------------------ |
2502 | -- Add_Validity_Check -- | |
2503 | ------------------------ | |
2504 | ||
2505 | procedure Add_Validity_Check | |
c9d70ab1 AC |
2506 | (Formal : Entity_Id; |
2507 | Prag_Nam : Name_Id; | |
0ea55619 AC |
2508 | For_Result : Boolean := False) |
2509 | is | |
c9d70ab1 AC |
2510 | procedure Build_Pre_Post_Condition (Expr : Node_Id); |
2511 | -- Create a pre/postcondition pragma that tests expression Expr | |
2512 | ||
2513 | ------------------------------ | |
2514 | -- Build_Pre_Post_Condition -- | |
2515 | ------------------------------ | |
2516 | ||
2517 | procedure Build_Pre_Post_Condition (Expr : Node_Id) is | |
2518 | Loc : constant Source_Ptr := Sloc (Subp); | |
2519 | Decls : List_Id; | |
2520 | Prag : Node_Id; | |
2521 | ||
2522 | begin | |
2523 | Prag := | |
2524 | Make_Pragma (Loc, | |
88456bc1 | 2525 | Chars => Prag_Nam, |
c9d70ab1 AC |
2526 | Pragma_Argument_Associations => New_List ( |
2527 | Make_Pragma_Argument_Association (Loc, | |
2528 | Chars => Name_Check, | |
2529 | Expression => Expr))); | |
2530 | ||
2531 | -- Add a message unless exception messages are suppressed | |
2532 | ||
2533 | if not Exception_Locations_Suppressed then | |
2534 | Append_To (Pragma_Argument_Associations (Prag), | |
2535 | Make_Pragma_Argument_Association (Loc, | |
2536 | Chars => Name_Message, | |
2537 | Expression => | |
2538 | Make_String_Literal (Loc, | |
2539 | Strval => "failed " | |
2540 | & Get_Name_String (Prag_Nam) | |
2541 | & " from " | |
2542 | & Build_Location_String (Loc)))); | |
2543 | end if; | |
2544 | ||
2545 | -- Insert the pragma in the tree | |
2546 | ||
2547 | if Nkind (Parent (Subp_Decl)) = N_Compilation_Unit then | |
2548 | Add_Global_Declaration (Prag); | |
2549 | Analyze (Prag); | |
2550 | ||
2551 | -- PPC pragmas associated with subprogram bodies must be inserted | |
2552 | -- in the declarative part of the body. | |
2553 | ||
2554 | elsif Nkind (Subp_Decl) = N_Subprogram_Body then | |
2555 | Decls := Declarations (Subp_Decl); | |
2556 | ||
2557 | if No (Decls) then | |
2558 | Decls := New_List; | |
2559 | Set_Declarations (Subp_Decl, Decls); | |
2560 | end if; | |
2561 | ||
2562 | Prepend_To (Decls, Prag); | |
2563 | Analyze (Prag); | |
2564 | ||
2565 | -- For subprogram declarations insert the PPC pragma right after | |
2566 | -- the declarative node. | |
2567 | ||
2568 | else | |
2569 | Insert_After_And_Analyze (Subp_Decl, Prag); | |
2570 | end if; | |
2571 | end Build_Pre_Post_Condition; | |
2572 | ||
2573 | -- Local variables | |
2574 | ||
e8dde875 | 2575 | Loc : constant Source_Ptr := Sloc (Subp); |
c9d70ab1 | 2576 | Typ : constant Entity_Id := Etype (Formal); |
0ea55619 AC |
2577 | Check : Node_Id; |
2578 | Nam : Name_Id; | |
2579 | ||
c9d70ab1 AC |
2580 | -- Start of processing for Add_Validity_Check |
2581 | ||
0ea55619 | 2582 | begin |
e5c4e2bc | 2583 | -- For scalars, generate 'Valid test |
0ea55619 AC |
2584 | |
2585 | if Is_Scalar_Type (Typ) then | |
2586 | Nam := Name_Valid; | |
e5c4e2bc AC |
2587 | |
2588 | -- For any non-scalar with scalar parts, generate 'Valid_Scalars test | |
2589 | ||
2590 | elsif Scalar_Part_Present (Typ) then | |
0ea55619 | 2591 | Nam := Name_Valid_Scalars; |
e5c4e2bc AC |
2592 | |
2593 | -- No test needed for other cases (no scalars to test) | |
2594 | ||
0ea55619 AC |
2595 | else |
2596 | return; | |
2597 | end if; | |
2598 | ||
2599 | -- Step 1: Create the expression to verify the validity of the | |
2600 | -- context. | |
2601 | ||
c9d70ab1 | 2602 | Check := New_Occurrence_Of (Formal, Loc); |
0ea55619 AC |
2603 | |
2604 | -- When processing a function result, use 'Result. Generate | |
2605 | -- Context'Result | |
2606 | ||
2607 | if For_Result then | |
2608 | Check := | |
2609 | Make_Attribute_Reference (Loc, | |
2610 | Prefix => Check, | |
2611 | Attribute_Name => Name_Result); | |
2612 | end if; | |
2613 | ||
2614 | -- Generate: | |
2615 | -- Context['Result]'Valid[_Scalars] | |
2616 | ||
2617 | Check := | |
2618 | Make_Attribute_Reference (Loc, | |
2619 | Prefix => Check, | |
2620 | Attribute_Name => Nam); | |
2621 | ||
e8dde875 AC |
2622 | -- Step 2: Create a pre or post condition pragma |
2623 | ||
c9d70ab1 | 2624 | Build_Pre_Post_Condition (Check); |
e8dde875 AC |
2625 | end Add_Validity_Check; |
2626 | ||
e8dde875 AC |
2627 | -- Local variables |
2628 | ||
2629 | Formal : Entity_Id; | |
e8dde875 AC |
2630 | Subp_Spec : Node_Id; |
2631 | ||
5f49133f | 2632 | -- Start of processing for Apply_Parameter_Validity_Checks |
0ea55619 AC |
2633 | |
2634 | begin | |
e8dde875 | 2635 | -- Extract the subprogram specification and declaration nodes |
0ea55619 | 2636 | |
e8dde875 | 2637 | Subp_Spec := Parent (Subp); |
9a6dc470 | 2638 | |
e8dde875 AC |
2639 | if Nkind (Subp_Spec) = N_Defining_Program_Unit_Name then |
2640 | Subp_Spec := Parent (Subp_Spec); | |
2641 | end if; | |
9a6dc470 | 2642 | |
e8dde875 | 2643 | Subp_Decl := Parent (Subp_Spec); |
8e983d80 | 2644 | |
0ea55619 | 2645 | if not Comes_From_Source (Subp) |
e8dde875 AC |
2646 | |
2647 | -- Do not process formal subprograms because the corresponding actual | |
2648 | -- will receive the proper checks when the instance is analyzed. | |
2649 | ||
2650 | or else Is_Formal_Subprogram (Subp) | |
2651 | ||
e0c23ac7 | 2652 | -- Do not process imported subprograms since pre and postconditions |
9a6dc470 | 2653 | -- are never verified on routines coming from a different language. |
e8dde875 | 2654 | |
0ea55619 AC |
2655 | or else Is_Imported (Subp) |
2656 | or else Is_Intrinsic_Subprogram (Subp) | |
e8dde875 | 2657 | |
9a6dc470 RD |
2658 | -- The PPC pragmas generated by this routine do not correspond to |
2659 | -- source aspects, therefore they cannot be applied to abstract | |
2660 | -- subprograms. | |
e8dde875 | 2661 | |
c5a26133 | 2662 | or else Nkind (Subp_Decl) = N_Abstract_Subprogram_Declaration |
e8dde875 | 2663 | |
9a6dc470 RD |
2664 | -- Do not consider subprogram renaminds because the renamed entity |
2665 | -- already has the proper PPC pragmas. | |
d85be3ba AC |
2666 | |
2667 | or else Nkind (Subp_Decl) = N_Subprogram_Renaming_Declaration | |
2668 | ||
9a6dc470 RD |
2669 | -- Do not process null procedures because there is no benefit of |
2670 | -- adding the checks to a no action routine. | |
e8dde875 AC |
2671 | |
2672 | or else (Nkind (Subp_Spec) = N_Procedure_Specification | |
9a6dc470 | 2673 | and then Null_Present (Subp_Spec)) |
0ea55619 AC |
2674 | then |
2675 | return; | |
2676 | end if; | |
2677 | ||
e8dde875 AC |
2678 | -- Inspect all the formals applying aliasing and scalar initialization |
2679 | -- checks where applicable. | |
0ea55619 AC |
2680 | |
2681 | Formal := First_Formal (Subp); | |
2682 | while Present (Formal) loop | |
e8dde875 AC |
2683 | |
2684 | -- Generate the following scalar initialization checks for each | |
2685 | -- formal parameter: | |
2686 | ||
2687 | -- mode IN - Pre => Formal'Valid[_Scalars] | |
2688 | -- mode IN OUT - Pre, Post => Formal'Valid[_Scalars] | |
2689 | -- mode OUT - Post => Formal'Valid[_Scalars] | |
2690 | ||
2691 | if Check_Validity_Of_Parameters then | |
2692 | if Ekind_In (Formal, E_In_Parameter, E_In_Out_Parameter) then | |
2693 | Add_Validity_Check (Formal, Name_Precondition, False); | |
2694 | end if; | |
2695 | ||
2696 | if Ekind_In (Formal, E_In_Out_Parameter, E_Out_Parameter) then | |
2697 | Add_Validity_Check (Formal, Name_Postcondition, False); | |
2698 | end if; | |
0ea55619 AC |
2699 | end if; |
2700 | ||
0ea55619 AC |
2701 | Next_Formal (Formal); |
2702 | end loop; | |
2703 | ||
9a6dc470 | 2704 | -- Generate following scalar initialization check for function result: |
e8dde875 AC |
2705 | |
2706 | -- Post => Subp'Result'Valid[_Scalars] | |
0ea55619 | 2707 | |
9a6dc470 | 2708 | if Check_Validity_Of_Parameters and then Ekind (Subp) = E_Function then |
e8dde875 | 2709 | Add_Validity_Check (Subp, Name_Postcondition, True); |
0ea55619 | 2710 | end if; |
5f49133f | 2711 | end Apply_Parameter_Validity_Checks; |
0ea55619 | 2712 | |
48f91b44 RD |
2713 | --------------------------- |
2714 | -- Apply_Predicate_Check -- | |
2715 | --------------------------- | |
2716 | ||
6eca51ce ES |
2717 | procedure Apply_Predicate_Check |
2718 | (N : Node_Id; | |
2719 | Typ : Entity_Id; | |
2720 | Fun : Entity_Id := Empty) | |
2721 | is | |
62db841a | 2722 | S : Entity_Id; |
8e983d80 | 2723 | |
48f91b44 | 2724 | begin |
1e60643a AC |
2725 | if Predicate_Checks_Suppressed (Empty) then |
2726 | return; | |
62db841a | 2727 | |
8d4611f7 AC |
2728 | elsif Predicates_Ignored (Typ) then |
2729 | return; | |
2730 | ||
1e60643a | 2731 | elsif Present (Predicate_Function (Typ)) then |
62db841a | 2732 | S := Current_Scope; |
8e983d80 | 2733 | while Present (S) and then not Is_Subprogram (S) loop |
62db841a AC |
2734 | S := Scope (S); |
2735 | end loop; | |
2736 | ||
8e1e62e3 AC |
2737 | -- A predicate check does not apply within internally generated |
2738 | -- subprograms, such as TSS functions. | |
2739 | ||
2740 | if Within_Internal_Subprogram then | |
62db841a | 2741 | return; |
0929eaeb | 2742 | |
3a0919e2 ES |
2743 | -- If the check appears within the predicate function itself, it |
2744 | -- means that the user specified a check whose formal is the | |
2745 | -- predicated subtype itself, rather than some covering type. This | |
2746 | -- is likely to be a common error, and thus deserves a warning. | |
0929eaeb | 2747 | |
155b4fcc | 2748 | elsif Present (S) and then S = Predicate_Function (Typ) then |
6eca51ce | 2749 | Error_Msg_NE |
e11b776b AC |
2750 | ("predicate check includes a call to& that requires a " |
2751 | & "predicate check??", Parent (N), Fun); | |
3a0919e2 | 2752 | Error_Msg_N |
685bc70f | 2753 | ("\this will result in infinite recursion??", Parent (N)); |
6eca51ce ES |
2754 | |
2755 | if Is_First_Subtype (Typ) then | |
2756 | Error_Msg_NE | |
e11b776b | 2757 | ("\use an explicit subtype of& to carry the predicate", |
6eca51ce ES |
2758 | Parent (N), Typ); |
2759 | end if; | |
2760 | ||
3a0919e2 | 2761 | Insert_Action (N, |
c7e152b5 AC |
2762 | Make_Raise_Storage_Error (Sloc (N), |
2763 | Reason => SE_Infinite_Recursion)); | |
0929eaeb | 2764 | |
0d5fbf52 | 2765 | -- Here for normal case of predicate active |
804fc056 | 2766 | |
c7e152b5 | 2767 | else |
db626148 ES |
2768 | -- If the expression is an IN parameter, the predicate will have |
2769 | -- been applied at the point of call. An additional check would | |
2770 | -- be redundant, or will lead to out-of-scope references if the | |
2771 | -- call appears within an aspect specification for a precondition. | |
2772 | ||
2773 | -- However, if the reference is within the body of the subprogram | |
2774 | -- that declares the formal, the predicate can safely be applied, | |
2775 | -- which may be necessary for a nested call whose formal has a | |
2776 | -- different predicate. | |
2777 | ||
2778 | if Is_Entity_Name (N) | |
2779 | and then Ekind (Entity (N)) = E_In_Parameter | |
2780 | then | |
2781 | declare | |
2782 | In_Body : Boolean := False; | |
6d0289b1 | 2783 | P : Node_Id := Parent (N); |
db626148 ES |
2784 | |
2785 | begin | |
2786 | while Present (P) loop | |
2787 | if Nkind (P) = N_Subprogram_Body | |
2788 | and then Corresponding_Spec (P) = Scope (Entity (N)) | |
2789 | then | |
2790 | In_Body := True; | |
2791 | exit; | |
2792 | end if; | |
2793 | ||
2794 | P := Parent (P); | |
2795 | end loop; | |
2796 | ||
2797 | if not In_Body then | |
2798 | return; | |
2799 | end if; | |
2800 | end; | |
2801 | end if; | |
2802 | ||
fd8b8c01 AC |
2803 | -- If the type has a static predicate and the expression is known |
2804 | -- at compile time, see if the expression satisfies the predicate. | |
f197d2f2 AC |
2805 | |
2806 | Check_Expression_Against_Static_Predicate (N, Typ); | |
804fc056 | 2807 | |
405b907c AC |
2808 | if not Expander_Active then |
2809 | return; | |
2810 | end if; | |
2811 | ||
2812 | -- For an entity of the type, generate a call to the predicate | |
2813 | -- function, unless its type is an actual subtype, which is not | |
2814 | -- visible outside of the enclosing subprogram. | |
2815 | ||
2816 | if Is_Entity_Name (N) | |
2817 | and then not Is_Actual_Subtype (Typ) | |
2818 | then | |
1e60643a AC |
2819 | Insert_Action (N, |
2820 | Make_Predicate_Check | |
2821 | (Typ, New_Occurrence_Of (Entity (N), Sloc (N)))); | |
2822 | ||
2cc2e964 | 2823 | -- If the expression is not an entity it may have side effects, |
558fbeb0 HK |
2824 | -- and the following call will create an object declaration for |
2825 | -- it. We disable checks during its analysis, to prevent an | |
2826 | -- infinite recursion. | |
1e60643a | 2827 | |
4269edf0 AC |
2828 | -- If the prefix is an aggregate in an assignment, apply the |
2829 | -- check to the LHS after assignment, rather than create a | |
2830 | -- redundant temporary. This is only necessary in rare cases | |
2831 | -- of array types (including strings) initialized with an | |
2832 | -- aggregate with an "others" clause, either coming from source | |
2833 | -- or generated by an Initialize_Scalars pragma. | |
2834 | ||
2835 | elsif Nkind (N) = N_Aggregate | |
2836 | and then Nkind (Parent (N)) = N_Assignment_Statement | |
2837 | then | |
2838 | Insert_Action_After (Parent (N), | |
2839 | Make_Predicate_Check | |
2840 | (Typ, Duplicate_Subexpr (Name (Parent (N))))); | |
2841 | ||
1e60643a AC |
2842 | else |
2843 | Insert_Action (N, | |
558fbeb0 HK |
2844 | Make_Predicate_Check |
2845 | (Typ, Duplicate_Subexpr (N)), Suppress => All_Checks); | |
1e60643a | 2846 | end if; |
62db841a | 2847 | end if; |
48f91b44 RD |
2848 | end if; |
2849 | end Apply_Predicate_Check; | |
2850 | ||
70482933 RK |
2851 | ----------------------- |
2852 | -- Apply_Range_Check -- | |
2853 | ----------------------- | |
2854 | ||
2855 | procedure Apply_Range_Check | |
2856 | (Ck_Node : Node_Id; | |
2857 | Target_Typ : Entity_Id; | |
2858 | Source_Typ : Entity_Id := Empty) | |
2859 | is | |
2860 | begin | |
2861 | Apply_Selected_Range_Checks | |
2862 | (Ck_Node, Target_Typ, Source_Typ, Do_Static => False); | |
2863 | end Apply_Range_Check; | |
2864 | ||
2865 | ------------------------------ | |
2866 | -- Apply_Scalar_Range_Check -- | |
2867 | ------------------------------ | |
2868 | ||
675d6070 TQ |
2869 | -- Note that Apply_Scalar_Range_Check never turns the Do_Range_Check flag |
2870 | -- off if it is already set on. | |
70482933 RK |
2871 | |
2872 | procedure Apply_Scalar_Range_Check | |
2873 | (Expr : Node_Id; | |
2874 | Target_Typ : Entity_Id; | |
2875 | Source_Typ : Entity_Id := Empty; | |
2876 | Fixed_Int : Boolean := False) | |
2877 | is | |
2878 | Parnt : constant Node_Id := Parent (Expr); | |
2879 | S_Typ : Entity_Id; | |
2880 | Arr : Node_Id := Empty; -- initialize to prevent warning | |
2881 | Arr_Typ : Entity_Id := Empty; -- initialize to prevent warning | |
70482933 RK |
2882 | |
2883 | Is_Subscr_Ref : Boolean; | |
2884 | -- Set true if Expr is a subscript | |
2885 | ||
2886 | Is_Unconstrained_Subscr_Ref : Boolean; | |
2887 | -- Set true if Expr is a subscript of an unconstrained array. In this | |
2888 | -- case we do not attempt to do an analysis of the value against the | |
2889 | -- range of the subscript, since we don't know the actual subtype. | |
2890 | ||
2891 | Int_Real : Boolean; | |
675d6070 TQ |
2892 | -- Set to True if Expr should be regarded as a real value even though |
2893 | -- the type of Expr might be discrete. | |
70482933 | 2894 | |
520c0201 AC |
2895 | procedure Bad_Value (Warn : Boolean := False); |
2896 | -- Procedure called if value is determined to be out of range. Warn is | |
2897 | -- True to force a warning instead of an error, even when SPARK_Mode is | |
2898 | -- On. | |
70482933 | 2899 | |
fbf5a39b AC |
2900 | --------------- |
2901 | -- Bad_Value -- | |
2902 | --------------- | |
2903 | ||
520c0201 | 2904 | procedure Bad_Value (Warn : Boolean := False) is |
70482933 RK |
2905 | begin |
2906 | Apply_Compile_Time_Constraint_Error | |
685bc70f | 2907 | (Expr, "value not in range of}??", CE_Range_Check_Failed, |
520c0201 AC |
2908 | Ent => Target_Typ, |
2909 | Typ => Target_Typ, | |
2910 | Warn => Warn); | |
70482933 RK |
2911 | end Bad_Value; |
2912 | ||
fbf5a39b AC |
2913 | -- Start of processing for Apply_Scalar_Range_Check |
2914 | ||
70482933 | 2915 | begin |
939c12d2 | 2916 | -- Return if check obviously not needed |
70482933 | 2917 | |
939c12d2 RD |
2918 | if |
2919 | -- Not needed inside generic | |
70482933 | 2920 | |
939c12d2 RD |
2921 | Inside_A_Generic |
2922 | ||
2923 | -- Not needed if previous error | |
2924 | ||
2925 | or else Target_Typ = Any_Type | |
2926 | or else Nkind (Expr) = N_Error | |
2927 | ||
2928 | -- Not needed for non-scalar type | |
2929 | ||
2930 | or else not Is_Scalar_Type (Target_Typ) | |
2931 | ||
2932 | -- Not needed if we know node raises CE already | |
2933 | ||
2934 | or else Raises_Constraint_Error (Expr) | |
70482933 RK |
2935 | then |
2936 | return; | |
2937 | end if; | |
2938 | ||
2939 | -- Now, see if checks are suppressed | |
2940 | ||
2941 | Is_Subscr_Ref := | |
2942 | Is_List_Member (Expr) and then Nkind (Parnt) = N_Indexed_Component; | |
2943 | ||
2944 | if Is_Subscr_Ref then | |
2945 | Arr := Prefix (Parnt); | |
2946 | Arr_Typ := Get_Actual_Subtype_If_Available (Arr); | |
ba759acd | 2947 | |
f4f92d9d | 2948 | if Is_Access_Type (Arr_Typ) then |
05c1e7d2 | 2949 | Arr_Typ := Designated_Type (Arr_Typ); |
f4f92d9d | 2950 | end if; |
70482933 RK |
2951 | end if; |
2952 | ||
2953 | if not Do_Range_Check (Expr) then | |
2954 | ||
2955 | -- Subscript reference. Check for Index_Checks suppressed | |
2956 | ||
2957 | if Is_Subscr_Ref then | |
2958 | ||
2959 | -- Check array type and its base type | |
2960 | ||
2961 | if Index_Checks_Suppressed (Arr_Typ) | |
fbf5a39b | 2962 | or else Index_Checks_Suppressed (Base_Type (Arr_Typ)) |
70482933 RK |
2963 | then |
2964 | return; | |
2965 | ||
2966 | -- Check array itself if it is an entity name | |
2967 | ||
2968 | elsif Is_Entity_Name (Arr) | |
fbf5a39b | 2969 | and then Index_Checks_Suppressed (Entity (Arr)) |
70482933 RK |
2970 | then |
2971 | return; | |
2972 | ||
2973 | -- Check expression itself if it is an entity name | |
2974 | ||
2975 | elsif Is_Entity_Name (Expr) | |
fbf5a39b | 2976 | and then Index_Checks_Suppressed (Entity (Expr)) |
70482933 RK |
2977 | then |
2978 | return; | |
2979 | end if; | |
2980 | ||
2981 | -- All other cases, check for Range_Checks suppressed | |
2982 | ||
2983 | else | |
2984 | -- Check target type and its base type | |
2985 | ||
2986 | if Range_Checks_Suppressed (Target_Typ) | |
fbf5a39b | 2987 | or else Range_Checks_Suppressed (Base_Type (Target_Typ)) |
70482933 RK |
2988 | then |
2989 | return; | |
2990 | ||
2991 | -- Check expression itself if it is an entity name | |
2992 | ||
2993 | elsif Is_Entity_Name (Expr) | |
fbf5a39b | 2994 | and then Range_Checks_Suppressed (Entity (Expr)) |
70482933 RK |
2995 | then |
2996 | return; | |
2997 | ||
675d6070 TQ |
2998 | -- If Expr is part of an assignment statement, then check left |
2999 | -- side of assignment if it is an entity name. | |
70482933 RK |
3000 | |
3001 | elsif Nkind (Parnt) = N_Assignment_Statement | |
3002 | and then Is_Entity_Name (Name (Parnt)) | |
fbf5a39b | 3003 | and then Range_Checks_Suppressed (Entity (Name (Parnt))) |
70482933 RK |
3004 | then |
3005 | return; | |
3006 | end if; | |
3007 | end if; | |
3008 | end if; | |
3009 | ||
fbf5a39b AC |
3010 | -- Do not set range checks if they are killed |
3011 | ||
3012 | if Nkind (Expr) = N_Unchecked_Type_Conversion | |
3013 | and then Kill_Range_Check (Expr) | |
3014 | then | |
3015 | return; | |
3016 | end if; | |
3017 | ||
3018 | -- Do not set range checks for any values from System.Scalar_Values | |
a90bd866 | 3019 | -- since the whole idea of such values is to avoid checking them. |
fbf5a39b AC |
3020 | |
3021 | if Is_Entity_Name (Expr) | |
3022 | and then Is_RTU (Scope (Entity (Expr)), System_Scalar_Values) | |
3023 | then | |
3024 | return; | |
3025 | end if; | |
3026 | ||
70482933 RK |
3027 | -- Now see if we need a check |
3028 | ||
3029 | if No (Source_Typ) then | |
3030 | S_Typ := Etype (Expr); | |
3031 | else | |
3032 | S_Typ := Source_Typ; | |
3033 | end if; | |
3034 | ||
3035 | if not Is_Scalar_Type (S_Typ) or else S_Typ = Any_Type then | |
3036 | return; | |
3037 | end if; | |
3038 | ||
3039 | Is_Unconstrained_Subscr_Ref := | |
3040 | Is_Subscr_Ref and then not Is_Constrained (Arr_Typ); | |
3041 | ||
347c766a | 3042 | -- Special checks for floating-point type |
70482933 | 3043 | |
347c766a RD |
3044 | if Is_Floating_Point_Type (S_Typ) then |
3045 | ||
3046 | -- Always do a range check if the source type includes infinities and | |
3047 | -- the target type does not include infinities. We do not do this if | |
3048 | -- range checks are killed. | |
aff557c7 AC |
3049 | -- If the expression is a literal and the bounds of the type are |
3050 | -- static constants it may be possible to optimize the check. | |
347c766a RD |
3051 | |
3052 | if Has_Infinities (S_Typ) | |
3053 | and then not Has_Infinities (Target_Typ) | |
3054 | then | |
aff557c7 AC |
3055 | -- If the expression is a literal and the bounds of the type are |
3056 | -- static constants it may be possible to optimize the check. | |
3057 | ||
3058 | if Nkind (Expr) = N_Real_Literal then | |
3059 | declare | |
3060 | Tlo : constant Node_Id := Type_Low_Bound (Target_Typ); | |
3061 | Thi : constant Node_Id := Type_High_Bound (Target_Typ); | |
3062 | ||
3063 | begin | |
3064 | if Compile_Time_Known_Value (Tlo) | |
3065 | and then Compile_Time_Known_Value (Thi) | |
3066 | and then Expr_Value_R (Expr) >= Expr_Value_R (Tlo) | |
3067 | and then Expr_Value_R (Expr) <= Expr_Value_R (Thi) | |
3068 | then | |
3069 | return; | |
3070 | else | |
3071 | Enable_Range_Check (Expr); | |
3072 | end if; | |
3073 | end; | |
3074 | ||
3075 | else | |
3076 | Enable_Range_Check (Expr); | |
3077 | end if; | |
347c766a | 3078 | end if; |
70482933 RK |
3079 | end if; |
3080 | ||
675d6070 TQ |
3081 | -- Return if we know expression is definitely in the range of the target |
3082 | -- type as determined by Determine_Range. Right now we only do this for | |
3083 | -- discrete types, and not fixed-point or floating-point types. | |
70482933 | 3084 | |
ddda9d0f | 3085 | -- The additional less-precise tests below catch these cases |
70482933 | 3086 | |
d8ee014f YM |
3087 | -- In GNATprove_Mode, also deal with the case of a conversion from |
3088 | -- floating-point to integer. It is only possible because analysis | |
3089 | -- in GNATprove rules out the possibility of a NaN or infinite value. | |
3090 | ||
675d6070 TQ |
3091 | -- Note: skip this if we are given a source_typ, since the point of |
3092 | -- supplying a Source_Typ is to stop us looking at the expression. | |
3093 | -- We could sharpen this test to be out parameters only ??? | |
70482933 RK |
3094 | |
3095 | if Is_Discrete_Type (Target_Typ) | |
d8ee014f YM |
3096 | and then (Is_Discrete_Type (Etype (Expr)) |
3097 | or else (GNATprove_Mode | |
3098 | and then Is_Floating_Point_Type (Etype (Expr)))) | |
70482933 RK |
3099 | and then not Is_Unconstrained_Subscr_Ref |
3100 | and then No (Source_Typ) | |
3101 | then | |
3102 | declare | |
70482933 | 3103 | Thi : constant Node_Id := Type_High_Bound (Target_Typ); |
94295b25 | 3104 | Tlo : constant Node_Id := Type_Low_Bound (Target_Typ); |
70482933 RK |
3105 | |
3106 | begin | |
3107 | if Compile_Time_Known_Value (Tlo) | |
3108 | and then Compile_Time_Known_Value (Thi) | |
3109 | then | |
fbf5a39b | 3110 | declare |
dcd5fd67 | 3111 | OK : Boolean := False; -- initialize to prevent warning |
fbf5a39b | 3112 | Hiv : constant Uint := Expr_Value (Thi); |
94295b25 | 3113 | Lov : constant Uint := Expr_Value (Tlo); |
dcd5fd67 PMR |
3114 | Hi : Uint := No_Uint; |
3115 | Lo : Uint := No_Uint; | |
70482933 | 3116 | |
fbf5a39b | 3117 | begin |
94295b25 AC |
3118 | -- If range is null, we for sure have a constraint error (we |
3119 | -- don't even need to look at the value involved, since all | |
3120 | -- possible values will raise CE). | |
fbf5a39b AC |
3121 | |
3122 | if Lov > Hiv then | |
39f0fa29 | 3123 | |
520c0201 AC |
3124 | -- When SPARK_Mode is On, force a warning instead of |
3125 | -- an error in that case, as this likely corresponds | |
3126 | -- to deactivated code. | |
3127 | ||
3128 | Bad_Value (Warn => SPARK_Mode = On); | |
3129 | ||
3130 | -- In GNATprove mode, we enable the range check so that | |
3131 | -- GNATprove will issue a message if it cannot be proved. | |
39f0fa29 AC |
3132 | |
3133 | if GNATprove_Mode then | |
3134 | Enable_Range_Check (Expr); | |
39f0fa29 AC |
3135 | end if; |
3136 | ||
fbf5a39b AC |
3137 | return; |
3138 | end if; | |
3139 | ||
3140 | -- Otherwise determine range of value | |
3141 | ||
d8ee014f | 3142 | if Is_Discrete_Type (Etype (Expr)) then |
94295b25 AC |
3143 | Determine_Range |
3144 | (Expr, OK, Lo, Hi, Assume_Valid => True); | |
d8ee014f YM |
3145 | |
3146 | -- When converting a float to an integer type, determine the | |
3147 | -- range in real first, and then convert the bounds using | |
3148 | -- UR_To_Uint which correctly rounds away from zero when | |
3149 | -- half way between two integers, as required by normal | |
3150 | -- Ada 95 rounding semantics. It is only possible because | |
3151 | -- analysis in GNATprove rules out the possibility of a NaN | |
3152 | -- or infinite value. | |
3153 | ||
3154 | elsif GNATprove_Mode | |
3155 | and then Is_Floating_Point_Type (Etype (Expr)) | |
3156 | then | |
3157 | declare | |
d8ee014f | 3158 | Hir : Ureal; |
94295b25 AC |
3159 | Lor : Ureal; |
3160 | ||
d8ee014f | 3161 | begin |
94295b25 AC |
3162 | Determine_Range_R |
3163 | (Expr, OK, Lor, Hir, Assume_Valid => True); | |
d8ee014f YM |
3164 | |
3165 | if OK then | |
3166 | Lo := UR_To_Uint (Lor); | |
3167 | Hi := UR_To_Uint (Hir); | |
3168 | end if; | |
3169 | end; | |
3170 | end if; | |
fbf5a39b AC |
3171 | |
3172 | if OK then | |
3173 | ||
3174 | -- If definitely in range, all OK | |
70482933 | 3175 | |
70482933 RK |
3176 | if Lo >= Lov and then Hi <= Hiv then |
3177 | return; | |
3178 | ||
fbf5a39b AC |
3179 | -- If definitely not in range, warn |
3180 | ||
70482933 | 3181 | elsif Lov > Hi or else Hiv < Lo then |
0c506265 | 3182 | |
88ad52c9 AC |
3183 | -- Ignore out of range values for System.Priority in |
3184 | -- CodePeer mode since the actual target compiler may | |
3185 | -- provide a wider range. | |
3186 | ||
3187 | if not CodePeer_Mode | |
3188 | or else Target_Typ /= RTE (RE_Priority) | |
3189 | then | |
3190 | Bad_Value; | |
3191 | end if; | |
3192 | ||
70482933 | 3193 | return; |
fbf5a39b AC |
3194 | |
3195 | -- Otherwise we don't know | |
3196 | ||
3197 | else | |
3198 | null; | |
70482933 | 3199 | end if; |
fbf5a39b AC |
3200 | end if; |
3201 | end; | |
70482933 RK |
3202 | end if; |
3203 | end; | |
3204 | end if; | |
3205 | ||
3206 | Int_Real := | |
3207 | Is_Floating_Point_Type (S_Typ) | |
3208 | or else (Is_Fixed_Point_Type (S_Typ) and then not Fixed_Int); | |
3209 | ||
3210 | -- Check if we can determine at compile time whether Expr is in the | |
fbf5a39b AC |
3211 | -- range of the target type. Note that if S_Typ is within the bounds |
3212 | -- of Target_Typ then this must be the case. This check is meaningful | |
3213 | -- only if this is not a conversion between integer and real types. | |
70482933 RK |
3214 | |
3215 | if not Is_Unconstrained_Subscr_Ref | |
347c766a | 3216 | and then Is_Discrete_Type (S_Typ) = Is_Discrete_Type (Target_Typ) |
70482933 | 3217 | and then |
c27f2f15 | 3218 | (In_Subrange_Of (S_Typ, Target_Typ, Fixed_Int) |
6d0b56ad AC |
3219 | |
3220 | -- Also check if the expression itself is in the range of the | |
3221 | -- target type if it is a known at compile time value. We skip | |
3222 | -- this test if S_Typ is set since for OUT and IN OUT parameters | |
3223 | -- the Expr itself is not relevant to the checking. | |
3224 | ||
70482933 | 3225 | or else |
6d0b56ad AC |
3226 | (No (Source_Typ) |
3227 | and then Is_In_Range (Expr, Target_Typ, | |
3228 | Assume_Valid => True, | |
3229 | Fixed_Int => Fixed_Int, | |
3230 | Int_Real => Int_Real))) | |
70482933 RK |
3231 | then |
3232 | return; | |
3233 | ||
c800f862 RD |
3234 | elsif Is_Out_Of_Range (Expr, Target_Typ, |
3235 | Assume_Valid => True, | |
3236 | Fixed_Int => Fixed_Int, | |
3237 | Int_Real => Int_Real) | |
3238 | then | |
70482933 RK |
3239 | Bad_Value; |
3240 | return; | |
3241 | ||
347c766a | 3242 | -- Floating-point case |
675d6070 TQ |
3243 | -- In the floating-point case, we only do range checks if the type is |
3244 | -- constrained. We definitely do NOT want range checks for unconstrained | |
0da343bc AC |
3245 | -- types, since we want to have infinities, except when |
3246 | -- Check_Float_Overflow is set. | |
70482933 | 3247 | |
fbf5a39b | 3248 | elsif Is_Floating_Point_Type (S_Typ) then |
0da343bc | 3249 | if Is_Constrained (S_Typ) or else Check_Float_Overflow then |
fbf5a39b AC |
3250 | Enable_Range_Check (Expr); |
3251 | end if; | |
70482933 | 3252 | |
fbf5a39b | 3253 | -- For all other cases we enable a range check unconditionally |
70482933 RK |
3254 | |
3255 | else | |
3256 | Enable_Range_Check (Expr); | |
3257 | return; | |
3258 | end if; | |
70482933 RK |
3259 | end Apply_Scalar_Range_Check; |
3260 | ||
3261 | ---------------------------------- | |
3262 | -- Apply_Selected_Length_Checks -- | |
3263 | ---------------------------------- | |
3264 | ||
3265 | procedure Apply_Selected_Length_Checks | |
3266 | (Ck_Node : Node_Id; | |
3267 | Target_Typ : Entity_Id; | |
3268 | Source_Typ : Entity_Id; | |
3269 | Do_Static : Boolean) | |
3270 | is | |
e0666fc6 AC |
3271 | Checks_On : constant Boolean := |
3272 | not Index_Checks_Suppressed (Target_Typ) | |
3273 | or else | |
3274 | not Length_Checks_Suppressed (Target_Typ); | |
3275 | ||
3276 | Loc : constant Source_Ptr := Sloc (Ck_Node); | |
3277 | ||
70482933 | 3278 | Cond : Node_Id; |
70482933 | 3279 | R_Cno : Node_Id; |
e0666fc6 | 3280 | R_Result : Check_Result; |
70482933 RK |
3281 | |
3282 | begin | |
66340e0e | 3283 | -- Only apply checks when generating code |
27bb7941 | 3284 | |
4a28b181 | 3285 | -- Note: this means that we lose some useful warnings if the expander |
27bb7941 | 3286 | -- is not active. |
4a28b181 | 3287 | |
66340e0e | 3288 | if not Expander_Active then |
70482933 RK |
3289 | return; |
3290 | end if; | |
3291 | ||
3292 | R_Result := | |
3293 | Selected_Length_Checks (Ck_Node, Target_Typ, Source_Typ, Empty); | |
3294 | ||
3295 | for J in 1 .. 2 loop | |
70482933 RK |
3296 | R_Cno := R_Result (J); |
3297 | exit when No (R_Cno); | |
3298 | ||
3299 | -- A length check may mention an Itype which is attached to a | |
3300 | -- subsequent node. At the top level in a package this can cause | |
3301 | -- an order-of-elaboration problem, so we make sure that the itype | |
3302 | -- is referenced now. | |
3303 | ||
3304 | if Ekind (Current_Scope) = E_Package | |
3305 | and then Is_Compilation_Unit (Current_Scope) | |
3306 | then | |
3307 | Ensure_Defined (Target_Typ, Ck_Node); | |
3308 | ||
3309 | if Present (Source_Typ) then | |
3310 | Ensure_Defined (Source_Typ, Ck_Node); | |
3311 | ||
3312 | elsif Is_Itype (Etype (Ck_Node)) then | |
3313 | Ensure_Defined (Etype (Ck_Node), Ck_Node); | |
3314 | end if; | |
3315 | end if; | |
3316 | ||
675d6070 TQ |
3317 | -- If the item is a conditional raise of constraint error, then have |
3318 | -- a look at what check is being performed and ??? | |
70482933 RK |
3319 | |
3320 | if Nkind (R_Cno) = N_Raise_Constraint_Error | |
3321 | and then Present (Condition (R_Cno)) | |
3322 | then | |
3323 | Cond := Condition (R_Cno); | |
3324 | ||
c064e066 | 3325 | -- Case where node does not now have a dynamic check |
70482933 | 3326 | |
c064e066 RD |
3327 | if not Has_Dynamic_Length_Check (Ck_Node) then |
3328 | ||
3329 | -- If checks are on, just insert the check | |
3330 | ||
3331 | if Checks_On then | |
3332 | Insert_Action (Ck_Node, R_Cno); | |
3333 | ||
3334 | if not Do_Static then | |
3335 | Set_Has_Dynamic_Length_Check (Ck_Node); | |
3336 | end if; | |
3337 | ||
3338 | -- If checks are off, then analyze the length check after | |
3339 | -- temporarily attaching it to the tree in case the relevant | |
308e6f3a | 3340 | -- condition can be evaluated at compile time. We still want a |
c064e066 RD |
3341 | -- compile time warning in this case. |
3342 | ||
3343 | else | |
3344 | Set_Parent (R_Cno, Ck_Node); | |
3345 | Analyze (R_Cno); | |
70482933 | 3346 | end if; |
70482933 RK |
3347 | end if; |
3348 | ||
3349 | -- Output a warning if the condition is known to be True | |
3350 | ||
3351 | if Is_Entity_Name (Cond) | |
3352 | and then Entity (Cond) = Standard_True | |
3353 | then | |
3354 | Apply_Compile_Time_Constraint_Error | |
685bc70f | 3355 | (Ck_Node, "wrong length for array of}??", |
07fc65c4 | 3356 | CE_Length_Check_Failed, |
70482933 RK |
3357 | Ent => Target_Typ, |
3358 | Typ => Target_Typ); | |
3359 | ||
3360 | -- If we were only doing a static check, or if checks are not | |
3361 | -- on, then we want to delete the check, since it is not needed. | |
3362 | -- We do this by replacing the if statement by a null statement | |
3363 | ||
3364 | elsif Do_Static or else not Checks_On then | |
11b4899f | 3365 | Remove_Warning_Messages (R_Cno); |
70482933 RK |
3366 | Rewrite (R_Cno, Make_Null_Statement (Loc)); |
3367 | end if; | |
3368 | ||
3369 | else | |
3370 | Install_Static_Check (R_Cno, Loc); | |
3371 | end if; | |
70482933 | 3372 | end loop; |
70482933 RK |
3373 | end Apply_Selected_Length_Checks; |
3374 | ||
3375 | --------------------------------- | |
3376 | -- Apply_Selected_Range_Checks -- | |
3377 | --------------------------------- | |
3378 | ||
3379 | procedure Apply_Selected_Range_Checks | |
3380 | (Ck_Node : Node_Id; | |
3381 | Target_Typ : Entity_Id; | |
3382 | Source_Typ : Entity_Id; | |
3383 | Do_Static : Boolean) | |
3384 | is | |
70482933 | 3385 | Checks_On : constant Boolean := |
f9966234 | 3386 | not Index_Checks_Suppressed (Target_Typ) |
6e32b1ab AC |
3387 | or else |
3388 | not Range_Checks_Suppressed (Target_Typ); | |
f9966234 | 3389 | |
e0666fc6 AC |
3390 | Loc : constant Source_Ptr := Sloc (Ck_Node); |
3391 | ||
f9966234 AC |
3392 | Cond : Node_Id; |
3393 | R_Cno : Node_Id; | |
3394 | R_Result : Check_Result; | |
70482933 RK |
3395 | |
3396 | begin | |
27bb7941 AC |
3397 | -- Only apply checks when generating code. In GNATprove mode, we do not |
3398 | -- apply the checks, but we still call Selected_Range_Checks to possibly | |
3399 | -- issue errors on SPARK code when a run-time error can be detected at | |
3400 | -- compile time. | |
3401 | ||
3402 | if not GNATprove_Mode then | |
3403 | if not Expander_Active or not Checks_On then | |
3404 | return; | |
3405 | end if; | |
70482933 RK |
3406 | end if; |
3407 | ||
3408 | R_Result := | |
3409 | Selected_Range_Checks (Ck_Node, Target_Typ, Source_Typ, Empty); | |
3410 | ||
27bb7941 AC |
3411 | if GNATprove_Mode then |
3412 | return; | |
3413 | end if; | |
3414 | ||
70482933 | 3415 | for J in 1 .. 2 loop |
70482933 RK |
3416 | R_Cno := R_Result (J); |
3417 | exit when No (R_Cno); | |
3418 | ||
f9966234 AC |
3419 | -- The range check requires runtime evaluation. Depending on what its |
3420 | -- triggering condition is, the check may be converted into a compile | |
3421 | -- time constraint check. | |
70482933 RK |
3422 | |
3423 | if Nkind (R_Cno) = N_Raise_Constraint_Error | |
3424 | and then Present (Condition (R_Cno)) | |
3425 | then | |
3426 | Cond := Condition (R_Cno); | |
3427 | ||
f9966234 AC |
3428 | -- Insert the range check before the related context. Note that |
3429 | -- this action analyses the triggering condition. | |
70482933 | 3430 | |
f9966234 AC |
3431 | Insert_Action (Ck_Node, R_Cno); |
3432 | ||
3433 | -- This old code doesn't make sense, why is the context flagged as | |
3434 | -- requiring dynamic range checks now in the middle of generating | |
3435 | -- them ??? | |
3436 | ||
3437 | if not Do_Static then | |
3438 | Set_Has_Dynamic_Range_Check (Ck_Node); | |
70482933 RK |
3439 | end if; |
3440 | ||
f9966234 AC |
3441 | -- The triggering condition evaluates to True, the range check |
3442 | -- can be converted into a compile time constraint check. | |
70482933 RK |
3443 | |
3444 | if Is_Entity_Name (Cond) | |
3445 | and then Entity (Cond) = Standard_True | |
3446 | then | |
675d6070 TQ |
3447 | -- Since an N_Range is technically not an expression, we have |
3448 | -- to set one of the bounds to C_E and then just flag the | |
3449 | -- N_Range. The warning message will point to the lower bound | |
3450 | -- and complain about a range, which seems OK. | |
70482933 RK |
3451 | |
3452 | if Nkind (Ck_Node) = N_Range then | |
3453 | Apply_Compile_Time_Constraint_Error | |
6e32b1ab AC |
3454 | (Low_Bound (Ck_Node), |
3455 | "static range out of bounds of}??", | |
07fc65c4 | 3456 | CE_Range_Check_Failed, |
70482933 RK |
3457 | Ent => Target_Typ, |
3458 | Typ => Target_Typ); | |
3459 | ||
3460 | Set_Raises_Constraint_Error (Ck_Node); | |
3461 | ||
3462 | else | |
3463 | Apply_Compile_Time_Constraint_Error | |
6e32b1ab | 3464 | (Ck_Node, |
b785e0b8 | 3465 | "static value out of range of}??", |
07fc65c4 | 3466 | CE_Range_Check_Failed, |
70482933 RK |
3467 | Ent => Target_Typ, |
3468 | Typ => Target_Typ); | |
3469 | end if; | |
3470 | ||
3471 | -- If we were only doing a static check, or if checks are not | |
3472 | -- on, then we want to delete the check, since it is not needed. | |
3473 | -- We do this by replacing the if statement by a null statement | |
3474 | ||
e49de265 | 3475 | elsif Do_Static then |
11b4899f | 3476 | Remove_Warning_Messages (R_Cno); |
70482933 RK |
3477 | Rewrite (R_Cno, Make_Null_Statement (Loc)); |
3478 | end if; | |
3479 | ||
57d3adcd | 3480 | -- The range check raises Constraint_Error explicitly |
f9966234 | 3481 | |
70482933 RK |
3482 | else |
3483 | Install_Static_Check (R_Cno, Loc); | |
3484 | end if; | |
70482933 | 3485 | end loop; |
70482933 RK |
3486 | end Apply_Selected_Range_Checks; |
3487 | ||
3488 | ------------------------------- | |
3489 | -- Apply_Static_Length_Check -- | |
3490 | ------------------------------- | |
3491 | ||
3492 | procedure Apply_Static_Length_Check | |
3493 | (Expr : Node_Id; | |
3494 | Target_Typ : Entity_Id; | |
3495 | Source_Typ : Entity_Id := Empty) | |
3496 | is | |
3497 | begin | |
3498 | Apply_Selected_Length_Checks | |
3499 | (Expr, Target_Typ, Source_Typ, Do_Static => True); | |
3500 | end Apply_Static_Length_Check; | |
3501 | ||
3502 | ------------------------------------- | |
3503 | -- Apply_Subscript_Validity_Checks -- | |
3504 | ------------------------------------- | |
3505 | ||
3506 | procedure Apply_Subscript_Validity_Checks (Expr : Node_Id) is | |
3507 | Sub : Node_Id; | |
3508 | ||
3509 | begin | |
3510 | pragma Assert (Nkind (Expr) = N_Indexed_Component); | |
3511 | ||
3512 | -- Loop through subscripts | |
3513 | ||
3514 | Sub := First (Expressions (Expr)); | |
3515 | while Present (Sub) loop | |
3516 | ||
675d6070 TQ |
3517 | -- Check one subscript. Note that we do not worry about enumeration |
3518 | -- type with holes, since we will convert the value to a Pos value | |
3519 | -- for the subscript, and that convert will do the necessary validity | |
3520 | -- check. | |
70482933 RK |
3521 | |
3522 | Ensure_Valid (Sub, Holes_OK => True); | |
3523 | ||
3524 | -- Move to next subscript | |
3525 | ||
3526 | Sub := Next (Sub); | |
3527 | end loop; | |
3528 | end Apply_Subscript_Validity_Checks; | |
3529 | ||
3530 | ---------------------------------- | |
3531 | -- Apply_Type_Conversion_Checks -- | |
3532 | ---------------------------------- | |
3533 | ||
3534 | procedure Apply_Type_Conversion_Checks (N : Node_Id) is | |
3535 | Target_Type : constant Entity_Id := Etype (N); | |
3536 | Target_Base : constant Entity_Id := Base_Type (Target_Type); | |
fbf5a39b | 3537 | Expr : constant Node_Id := Expression (N); |
2c1a2cf3 RD |
3538 | |
3539 | Expr_Type : constant Entity_Id := Underlying_Type (Etype (Expr)); | |
1197ddb1 AC |
3540 | -- Note: if Etype (Expr) is a private type without discriminants, its |
3541 | -- full view might have discriminants with defaults, so we need the | |
3542 | -- full view here to retrieve the constraints. | |
70482933 RK |
3543 | |
3544 | begin | |
3545 | if Inside_A_Generic then | |
3546 | return; | |
3547 | ||
07fc65c4 | 3548 | -- Skip these checks if serious errors detected, there are some nasty |
70482933 RK |
3549 | -- situations of incomplete trees that blow things up. |
3550 | ||
07fc65c4 | 3551 | elsif Serious_Errors_Detected > 0 then |
70482933 RK |
3552 | return; |
3553 | ||
8e1e62e3 AC |
3554 | -- Never generate discriminant checks for Unchecked_Union types |
3555 | ||
3556 | elsif Present (Expr_Type) | |
3557 | and then Is_Unchecked_Union (Expr_Type) | |
3558 | then | |
3559 | return; | |
3560 | ||
675d6070 TQ |
3561 | -- Scalar type conversions of the form Target_Type (Expr) require a |
3562 | -- range check if we cannot be sure that Expr is in the base type of | |
3563 | -- Target_Typ and also that Expr is in the range of Target_Typ. These | |
3564 | -- are not quite the same condition from an implementation point of | |
3565 | -- view, but clearly the second includes the first. | |
70482933 RK |
3566 | |
3567 | elsif Is_Scalar_Type (Target_Type) then | |
3568 | declare | |
3569 | Conv_OK : constant Boolean := Conversion_OK (N); | |
675d6070 | 3570 | -- If the Conversion_OK flag on the type conversion is set and no |
8e1e62e3 AC |
3571 | -- floating-point type is involved in the type conversion then |
3572 | -- fixed-point values must be read as integral values. | |
70482933 | 3573 | |
7324bf49 | 3574 | Float_To_Int : constant Boolean := |
15f0f591 AC |
3575 | Is_Floating_Point_Type (Expr_Type) |
3576 | and then Is_Integer_Type (Target_Type); | |
7324bf49 | 3577 | |
70482933 | 3578 | begin |
70482933 | 3579 | if not Overflow_Checks_Suppressed (Target_Base) |
a7f1b24f | 3580 | and then not Overflow_Checks_Suppressed (Target_Type) |
1c7717c3 | 3581 | and then not |
c27f2f15 | 3582 | In_Subrange_Of (Expr_Type, Target_Base, Fixed_Int => Conv_OK) |
7324bf49 | 3583 | and then not Float_To_Int |
70482933 | 3584 | then |
82e5c243 | 3585 | -- A small optimization: the attribute 'Pos applied to an |
0929d66b AC |
3586 | -- enumeration type has a known range, even though its type is |
3587 | -- Universal_Integer. So in numeric conversions it is usually | |
3588 | -- within range of the target integer type. Use the static | |
3589 | -- bounds of the base types to check. Disable this optimization | |
3590 | -- in case of a generic formal discrete type, because we don't | |
3591 | -- necessarily know the upper bound yet. | |
f8981f19 AC |
3592 | |
3593 | if Nkind (Expr) = N_Attribute_Reference | |
3594 | and then Attribute_Name (Expr) = Name_Pos | |
3595 | and then Is_Enumeration_Type (Etype (Prefix (Expr))) | |
0929d66b | 3596 | and then not Is_Generic_Type (Etype (Prefix (Expr))) |
f8981f19 AC |
3597 | and then Is_Integer_Type (Target_Type) |
3598 | then | |
3599 | declare | |
82e5c243 AC |
3600 | Enum_T : constant Entity_Id := |
3601 | Root_Type (Etype (Prefix (Expr))); | |
3602 | Int_T : constant Entity_Id := Base_Type (Target_Type); | |
3603 | Last_I : constant Uint := | |
3604 | Intval (High_Bound (Scalar_Range (Int_T))); | |
3605 | Last_E : Uint; | |
f8981f19 AC |
3606 | |
3607 | begin | |
82e5c243 | 3608 | -- Character types have no explicit literals, so we use |
f8981f19 AC |
3609 | -- the known number of characters in the type. |
3610 | ||
3611 | if Root_Type (Enum_T) = Standard_Character then | |
3612 | Last_E := UI_From_Int (255); | |
3613 | ||
3614 | elsif Enum_T = Standard_Wide_Character | |
3615 | or else Enum_T = Standard_Wide_Wide_Character | |
3616 | then | |
3617 | Last_E := UI_From_Int (65535); | |
3618 | ||
3619 | else | |
82e5c243 AC |
3620 | Last_E := |
3621 | Enumeration_Pos | |
f8981f19 AC |
3622 | (Entity (High_Bound (Scalar_Range (Enum_T)))); |
3623 | end if; | |
3624 | ||
3625 | if Last_E <= Last_I then | |
3626 | null; | |
3627 | ||
3628 | else | |
3629 | Activate_Overflow_Check (N); | |
3630 | end if; | |
3631 | end; | |
3632 | ||
3633 | else | |
3634 | Activate_Overflow_Check (N); | |
3635 | end if; | |
70482933 RK |
3636 | end if; |
3637 | ||
3638 | if not Range_Checks_Suppressed (Target_Type) | |
3639 | and then not Range_Checks_Suppressed (Expr_Type) | |
3640 | then | |
d8ee014f YM |
3641 | if Float_To_Int |
3642 | and then not GNATprove_Mode | |
3643 | then | |
7324bf49 | 3644 | Apply_Float_Conversion_Check (Expr, Target_Type); |
61770974 | 3645 | |
7324bf49 | 3646 | else |
241848fd ES |
3647 | -- Conversions involving fixed-point types are expanded |
3648 | -- separately, and do not need a Range_Check flag, except | |
c7862167 HK |
3649 | -- in GNATprove_Mode, where the explicit constraint check |
3650 | -- will not be generated. | |
241848fd | 3651 | |
94a98e80 | 3652 | if GNATprove_Mode |
8113b0c7 EB |
3653 | or else (not Is_Fixed_Point_Type (Expr_Type) |
3654 | and then not Is_Fixed_Point_Type (Target_Type)) | |
241848fd ES |
3655 | then |
3656 | Apply_Scalar_Range_Check | |
3657 | (Expr, Target_Type, Fixed_Int => Conv_OK); | |
3658 | ||
3659 | else | |
8113b0c7 | 3660 | Set_Do_Range_Check (Expr, False); |
241848fd | 3661 | end if; |
b2009d46 AC |
3662 | |
3663 | -- If the target type has predicates, we need to indicate | |
8e1e62e3 AC |
3664 | -- the need for a check, even if Determine_Range finds that |
3665 | -- the value is within bounds. This may be the case e.g for | |
3666 | -- a division with a constant denominator. | |
b2009d46 AC |
3667 | |
3668 | if Has_Predicates (Target_Type) then | |
3669 | Enable_Range_Check (Expr); | |
3670 | end if; | |
7324bf49 | 3671 | end if; |
70482933 RK |
3672 | end if; |
3673 | end; | |
3674 | ||
3675 | elsif Comes_From_Source (N) | |
ec2dd67a | 3676 | and then not Discriminant_Checks_Suppressed (Target_Type) |
70482933 RK |
3677 | and then Is_Record_Type (Target_Type) |
3678 | and then Is_Derived_Type (Target_Type) | |
3679 | and then not Is_Tagged_Type (Target_Type) | |
3680 | and then not Is_Constrained (Target_Type) | |
fbf5a39b | 3681 | and then Present (Stored_Constraint (Target_Type)) |
70482933 | 3682 | then |
1197ddb1 | 3683 | -- An unconstrained derived type may have inherited discriminant. |
fbf5a39b | 3684 | -- Build an actual discriminant constraint list using the stored |
70482933 | 3685 | -- constraint, to verify that the expression of the parent type |
8e1e62e3 AC |
3686 | -- satisfies the constraints imposed by the (unconstrained) derived |
3687 | -- type. This applies to value conversions, not to view conversions | |
3688 | -- of tagged types. | |
70482933 RK |
3689 | |
3690 | declare | |
fbf5a39b AC |
3691 | Loc : constant Source_Ptr := Sloc (N); |
3692 | Cond : Node_Id; | |
3693 | Constraint : Elmt_Id; | |
3694 | Discr_Value : Node_Id; | |
3695 | Discr : Entity_Id; | |
3696 | ||
3697 | New_Constraints : constant Elist_Id := New_Elmt_List; | |
3698 | Old_Constraints : constant Elist_Id := | |
15f0f591 | 3699 | Discriminant_Constraint (Expr_Type); |
70482933 RK |
3700 | |
3701 | begin | |
fbf5a39b | 3702 | Constraint := First_Elmt (Stored_Constraint (Target_Type)); |
70482933 RK |
3703 | while Present (Constraint) loop |
3704 | Discr_Value := Node (Constraint); | |
3705 | ||
3706 | if Is_Entity_Name (Discr_Value) | |
3707 | and then Ekind (Entity (Discr_Value)) = E_Discriminant | |
3708 | then | |
3709 | Discr := Corresponding_Discriminant (Entity (Discr_Value)); | |
3710 | ||
3711 | if Present (Discr) | |
3712 | and then Scope (Discr) = Base_Type (Expr_Type) | |
3713 | then | |
3714 | -- Parent is constrained by new discriminant. Obtain | |
675d6070 TQ |
3715 | -- Value of original discriminant in expression. If the |
3716 | -- new discriminant has been used to constrain more than | |
3717 | -- one of the stored discriminants, this will provide the | |
3718 | -- required consistency check. | |
70482933 | 3719 | |
7675ad4f AC |
3720 | Append_Elmt |
3721 | (Make_Selected_Component (Loc, | |
3722 | Prefix => | |
fbf5a39b AC |
3723 | Duplicate_Subexpr_No_Checks |
3724 | (Expr, Name_Req => True), | |
70482933 RK |
3725 | Selector_Name => |
3726 | Make_Identifier (Loc, Chars (Discr))), | |
7675ad4f | 3727 | New_Constraints); |
70482933 RK |
3728 | |
3729 | else | |
3730 | -- Discriminant of more remote ancestor ??? | |
3731 | ||
3732 | return; | |
3733 | end if; | |
3734 | ||
675d6070 TQ |
3735 | -- Derived type definition has an explicit value for this |
3736 | -- stored discriminant. | |
70482933 RK |
3737 | |
3738 | else | |
3739 | Append_Elmt | |
fbf5a39b AC |
3740 | (Duplicate_Subexpr_No_Checks (Discr_Value), |
3741 | New_Constraints); | |
70482933 RK |
3742 | end if; |
3743 | ||
3744 | Next_Elmt (Constraint); | |
3745 | end loop; | |
3746 | ||
3747 | -- Use the unconstrained expression type to retrieve the | |
3748 | -- discriminants of the parent, and apply momentarily the | |
3749 | -- discriminant constraint synthesized above. | |
3750 | ||
3751 | Set_Discriminant_Constraint (Expr_Type, New_Constraints); | |
3752 | Cond := Build_Discriminant_Checks (Expr, Expr_Type); | |
3753 | Set_Discriminant_Constraint (Expr_Type, Old_Constraints); | |
3754 | ||
3755 | Insert_Action (N, | |
07fc65c4 GB |
3756 | Make_Raise_Constraint_Error (Loc, |
3757 | Condition => Cond, | |
3758 | Reason => CE_Discriminant_Check_Failed)); | |
70482933 RK |
3759 | end; |
3760 | ||
8bfbd380 AC |
3761 | -- For arrays, checks are set now, but conversions are applied during |
3762 | -- expansion, to take into accounts changes of representation. The | |
3763 | -- checks become range checks on the base type or length checks on the | |
3764 | -- subtype, depending on whether the target type is unconstrained or | |
83851b23 AC |
3765 | -- constrained. Note that the range check is put on the expression of a |
3766 | -- type conversion, while the length check is put on the type conversion | |
3767 | -- itself. | |
8bfbd380 AC |
3768 | |
3769 | elsif Is_Array_Type (Target_Type) then | |
3770 | if Is_Constrained (Target_Type) then | |
3771 | Set_Do_Length_Check (N); | |
3772 | else | |
3773 | Set_Do_Range_Check (Expr); | |
3774 | end if; | |
70482933 | 3775 | end if; |
70482933 RK |
3776 | end Apply_Type_Conversion_Checks; |
3777 | ||
3778 | ---------------------------------------------- | |
3779 | -- Apply_Universal_Integer_Attribute_Checks -- | |
3780 | ---------------------------------------------- | |
3781 | ||
3782 | procedure Apply_Universal_Integer_Attribute_Checks (N : Node_Id) is | |
3783 | Loc : constant Source_Ptr := Sloc (N); | |
3784 | Typ : constant Entity_Id := Etype (N); | |
3785 | ||
3786 | begin | |
3787 | if Inside_A_Generic then | |
3788 | return; | |
3789 | ||
3790 | -- Nothing to do if checks are suppressed | |
3791 | ||
3792 | elsif Range_Checks_Suppressed (Typ) | |
3793 | and then Overflow_Checks_Suppressed (Typ) | |
3794 | then | |
3795 | return; | |
3796 | ||
3797 | -- Nothing to do if the attribute does not come from source. The | |
3798 | -- internal attributes we generate of this type do not need checks, | |
3799 | -- and furthermore the attempt to check them causes some circular | |
3800 | -- elaboration orders when dealing with packed types. | |
3801 | ||
3802 | elsif not Comes_From_Source (N) then | |
3803 | return; | |
3804 | ||
fbf5a39b AC |
3805 | -- If the prefix is a selected component that depends on a discriminant |
3806 | -- the check may improperly expose a discriminant instead of using | |
3807 | -- the bounds of the object itself. Set the type of the attribute to | |
3808 | -- the base type of the context, so that a check will be imposed when | |
3809 | -- needed (e.g. if the node appears as an index). | |
3810 | ||
3811 | elsif Nkind (Prefix (N)) = N_Selected_Component | |
3812 | and then Ekind (Typ) = E_Signed_Integer_Subtype | |
3813 | and then Depends_On_Discriminant (Scalar_Range (Typ)) | |
3814 | then | |
3815 | Set_Etype (N, Base_Type (Typ)); | |
3816 | ||
675d6070 TQ |
3817 | -- Otherwise, replace the attribute node with a type conversion node |
3818 | -- whose expression is the attribute, retyped to universal integer, and | |
3819 | -- whose subtype mark is the target type. The call to analyze this | |
3820 | -- conversion will set range and overflow checks as required for proper | |
3821 | -- detection of an out of range value. | |
70482933 RK |
3822 | |
3823 | else | |
3824 | Set_Etype (N, Universal_Integer); | |
3825 | Set_Analyzed (N, True); | |
3826 | ||
3827 | Rewrite (N, | |
3828 | Make_Type_Conversion (Loc, | |
3829 | Subtype_Mark => New_Occurrence_Of (Typ, Loc), | |
3830 | Expression => Relocate_Node (N))); | |
3831 | ||
3832 | Analyze_And_Resolve (N, Typ); | |
3833 | return; | |
3834 | end if; | |
70482933 RK |
3835 | end Apply_Universal_Integer_Attribute_Checks; |
3836 | ||
12b4d338 AC |
3837 | ------------------------------------- |
3838 | -- Atomic_Synchronization_Disabled -- | |
3839 | ------------------------------------- | |
3840 | ||
3841 | -- Note: internally Disable/Enable_Atomic_Synchronization is implemented | |
3842 | -- using a bogus check called Atomic_Synchronization. This is to make it | |
3843 | -- more convenient to get exactly the same semantics as [Un]Suppress. | |
3844 | ||
3845 | function Atomic_Synchronization_Disabled (E : Entity_Id) return Boolean is | |
3846 | begin | |
4c318253 AC |
3847 | -- If debug flag d.e is set, always return False, i.e. all atomic sync |
3848 | -- looks enabled, since it is never disabled. | |
3849 | ||
3850 | if Debug_Flag_Dot_E then | |
3851 | return False; | |
3852 | ||
3853 | -- If debug flag d.d is set then always return True, i.e. all atomic | |
3854 | -- sync looks disabled, since it always tests True. | |
3855 | ||
3856 | elsif Debug_Flag_Dot_D then | |
3857 | return True; | |
3858 | ||
3859 | -- If entity present, then check result for that entity | |
3860 | ||
3861 | elsif Present (E) and then Checks_May_Be_Suppressed (E) then | |
12b4d338 | 3862 | return Is_Check_Suppressed (E, Atomic_Synchronization); |
4c318253 AC |
3863 | |
3864 | -- Otherwise result depends on current scope setting | |
3865 | ||
12b4d338 | 3866 | else |
3217f71e | 3867 | return Scope_Suppress.Suppress (Atomic_Synchronization); |
12b4d338 AC |
3868 | end if; |
3869 | end Atomic_Synchronization_Disabled; | |
3870 | ||
70482933 RK |
3871 | ------------------------------- |
3872 | -- Build_Discriminant_Checks -- | |
3873 | ------------------------------- | |
3874 | ||
3875 | function Build_Discriminant_Checks | |
3876 | (N : Node_Id; | |
6b6fcd3e | 3877 | T_Typ : Entity_Id) return Node_Id |
70482933 RK |
3878 | is |
3879 | Loc : constant Source_Ptr := Sloc (N); | |
3880 | Cond : Node_Id; | |
3881 | Disc : Elmt_Id; | |
3882 | Disc_Ent : Entity_Id; | |
fbf5a39b | 3883 | Dref : Node_Id; |
70482933 RK |
3884 | Dval : Node_Id; |
3885 | ||
86ac5e79 ES |
3886 | function Aggregate_Discriminant_Val (Disc : Entity_Id) return Node_Id; |
3887 | ||
8016e567 PT |
3888 | -------------------------------- |
3889 | -- Aggregate_Discriminant_Val -- | |
3890 | -------------------------------- | |
86ac5e79 ES |
3891 | |
3892 | function Aggregate_Discriminant_Val (Disc : Entity_Id) return Node_Id is | |
3893 | Assoc : Node_Id; | |
3894 | ||
3895 | begin | |
675d6070 TQ |
3896 | -- The aggregate has been normalized with named associations. We use |
3897 | -- the Chars field to locate the discriminant to take into account | |
3898 | -- discriminants in derived types, which carry the same name as those | |
3899 | -- in the parent. | |
86ac5e79 ES |
3900 | |
3901 | Assoc := First (Component_Associations (N)); | |
3902 | while Present (Assoc) loop | |
3903 | if Chars (First (Choices (Assoc))) = Chars (Disc) then | |
3904 | return Expression (Assoc); | |
3905 | else | |
3906 | Next (Assoc); | |
3907 | end if; | |
3908 | end loop; | |
3909 | ||
3910 | -- Discriminant must have been found in the loop above | |
3911 | ||
3912 | raise Program_Error; | |
3913 | end Aggregate_Discriminant_Val; | |
3914 | ||
3915 | -- Start of processing for Build_Discriminant_Checks | |
3916 | ||
70482933 | 3917 | begin |
86ac5e79 ES |
3918 | -- Loop through discriminants evolving the condition |
3919 | ||
70482933 RK |
3920 | Cond := Empty; |
3921 | Disc := First_Elmt (Discriminant_Constraint (T_Typ)); | |
3922 | ||
fbf5a39b | 3923 | -- For a fully private type, use the discriminants of the parent type |
70482933 RK |
3924 | |
3925 | if Is_Private_Type (T_Typ) | |
3926 | and then No (Full_View (T_Typ)) | |
3927 | then | |
3928 | Disc_Ent := First_Discriminant (Etype (Base_Type (T_Typ))); | |
3929 | else | |
3930 | Disc_Ent := First_Discriminant (T_Typ); | |
3931 | end if; | |
3932 | ||
3933 | while Present (Disc) loop | |
70482933 RK |
3934 | Dval := Node (Disc); |
3935 | ||
3936 | if Nkind (Dval) = N_Identifier | |
3937 | and then Ekind (Entity (Dval)) = E_Discriminant | |
3938 | then | |
3939 | Dval := New_Occurrence_Of (Discriminal (Entity (Dval)), Loc); | |
3940 | else | |
fbf5a39b | 3941 | Dval := Duplicate_Subexpr_No_Checks (Dval); |
70482933 RK |
3942 | end if; |
3943 | ||
5d09245e AC |
3944 | -- If we have an Unchecked_Union node, we can infer the discriminants |
3945 | -- of the node. | |
fbf5a39b | 3946 | |
5d09245e AC |
3947 | if Is_Unchecked_Union (Base_Type (T_Typ)) then |
3948 | Dref := New_Copy ( | |
3949 | Get_Discriminant_Value ( | |
3950 | First_Discriminant (T_Typ), | |
3951 | T_Typ, | |
3952 | Stored_Constraint (T_Typ))); | |
3953 | ||
86ac5e79 ES |
3954 | elsif Nkind (N) = N_Aggregate then |
3955 | Dref := | |
3956 | Duplicate_Subexpr_No_Checks | |
3957 | (Aggregate_Discriminant_Val (Disc_Ent)); | |
3958 | ||
5d09245e AC |
3959 | else |
3960 | Dref := | |
3961 | Make_Selected_Component (Loc, | |
637a41a5 | 3962 | Prefix => |
5d09245e | 3963 | Duplicate_Subexpr_No_Checks (N, Name_Req => True), |
637a41a5 | 3964 | Selector_Name => Make_Identifier (Loc, Chars (Disc_Ent))); |
5d09245e AC |
3965 | |
3966 | Set_Is_In_Discriminant_Check (Dref); | |
3967 | end if; | |
fbf5a39b | 3968 | |
70482933 RK |
3969 | Evolve_Or_Else (Cond, |
3970 | Make_Op_Ne (Loc, | |
637a41a5 | 3971 | Left_Opnd => Dref, |
70482933 RK |
3972 | Right_Opnd => Dval)); |
3973 | ||
3974 | Next_Elmt (Disc); | |
3975 | Next_Discriminant (Disc_Ent); | |
3976 | end loop; | |
3977 | ||
3978 | return Cond; | |
3979 | end Build_Discriminant_Checks; | |
3980 | ||
2ede092b RD |
3981 | ------------------ |
3982 | -- Check_Needed -- | |
3983 | ------------------ | |
3984 | ||
3985 | function Check_Needed (Nod : Node_Id; Check : Check_Type) return Boolean is | |
3986 | N : Node_Id; | |
3987 | P : Node_Id; | |
3988 | K : Node_Kind; | |
3989 | L : Node_Id; | |
3990 | R : Node_Id; | |
3991 | ||
ef163a0a AC |
3992 | function Left_Expression (Op : Node_Id) return Node_Id; |
3993 | -- Return the relevant expression from the left operand of the given | |
3994 | -- short circuit form: this is LO itself, except if LO is a qualified | |
3995 | -- expression, a type conversion, or an expression with actions, in | |
3996 | -- which case this is Left_Expression (Expression (LO)). | |
3997 | ||
3998 | --------------------- | |
3999 | -- Left_Expression -- | |
4000 | --------------------- | |
4001 | ||
4002 | function Left_Expression (Op : Node_Id) return Node_Id is | |
4003 | LE : Node_Id := Left_Opnd (Op); | |
4004 | begin | |
637a41a5 AC |
4005 | while Nkind_In (LE, N_Qualified_Expression, |
4006 | N_Type_Conversion, | |
4007 | N_Expression_With_Actions) | |
ef163a0a AC |
4008 | loop |
4009 | LE := Expression (LE); | |
4010 | end loop; | |
4011 | ||
4012 | return LE; | |
4013 | end Left_Expression; | |
4014 | ||
4015 | -- Start of processing for Check_Needed | |
4016 | ||
2ede092b RD |
4017 | begin |
4018 | -- Always check if not simple entity | |
4019 | ||
4020 | if Nkind (Nod) not in N_Has_Entity | |
4021 | or else not Comes_From_Source (Nod) | |
4022 | then | |
4023 | return True; | |
4024 | end if; | |
4025 | ||
4026 | -- Look up tree for short circuit | |
4027 | ||
4028 | N := Nod; | |
4029 | loop | |
4030 | P := Parent (N); | |
4031 | K := Nkind (P); | |
4032 | ||
16a55e63 RD |
4033 | -- Done if out of subexpression (note that we allow generated stuff |
4034 | -- such as itype declarations in this context, to keep the loop going | |
4035 | -- since we may well have generated such stuff in complex situations. | |
4036 | -- Also done if no parent (probably an error condition, but no point | |
a90bd866 | 4037 | -- in behaving nasty if we find it). |
16a55e63 RD |
4038 | |
4039 | if No (P) | |
4040 | or else (K not in N_Subexpr and then Comes_From_Source (P)) | |
4041 | then | |
2ede092b RD |
4042 | return True; |
4043 | ||
16a55e63 RD |
4044 | -- Or/Or Else case, where test is part of the right operand, or is |
4045 | -- part of one of the actions associated with the right operand, and | |
4046 | -- the left operand is an equality test. | |
2ede092b | 4047 | |
16a55e63 | 4048 | elsif K = N_Op_Or then |
2ede092b | 4049 | exit when N = Right_Opnd (P) |
ef163a0a | 4050 | and then Nkind (Left_Expression (P)) = N_Op_Eq; |
2ede092b | 4051 | |
16a55e63 RD |
4052 | elsif K = N_Or_Else then |
4053 | exit when (N = Right_Opnd (P) | |
4054 | or else | |
4055 | (Is_List_Member (N) | |
4056 | and then List_Containing (N) = Actions (P))) | |
ef163a0a | 4057 | and then Nkind (Left_Expression (P)) = N_Op_Eq; |
2ede092b | 4058 | |
16a55e63 RD |
4059 | -- Similar test for the And/And then case, where the left operand |
4060 | -- is an inequality test. | |
4061 | ||
4062 | elsif K = N_Op_And then | |
2ede092b | 4063 | exit when N = Right_Opnd (P) |
ef163a0a | 4064 | and then Nkind (Left_Expression (P)) = N_Op_Ne; |
16a55e63 RD |
4065 | |
4066 | elsif K = N_And_Then then | |
4067 | exit when (N = Right_Opnd (P) | |
4068 | or else | |
4069 | (Is_List_Member (N) | |
637a41a5 | 4070 | and then List_Containing (N) = Actions (P))) |
ef163a0a | 4071 | and then Nkind (Left_Expression (P)) = N_Op_Ne; |
2ede092b RD |
4072 | end if; |
4073 | ||
4074 | N := P; | |
4075 | end loop; | |
4076 | ||
4077 | -- If we fall through the loop, then we have a conditional with an | |
ef163a0a AC |
4078 | -- appropriate test as its left operand, so look further. |
4079 | ||
4080 | L := Left_Expression (P); | |
4081 | ||
4082 | -- L is an "=" or "/=" operator: extract its operands | |
2ede092b | 4083 | |
2ede092b RD |
4084 | R := Right_Opnd (L); |
4085 | L := Left_Opnd (L); | |
4086 | ||
4087 | -- Left operand of test must match original variable | |
4088 | ||
637a41a5 | 4089 | if Nkind (L) not in N_Has_Entity or else Entity (L) /= Entity (Nod) then |
2ede092b RD |
4090 | return True; |
4091 | end if; | |
4092 | ||
939c12d2 | 4093 | -- Right operand of test must be key value (zero or null) |
2ede092b RD |
4094 | |
4095 | case Check is | |
4096 | when Access_Check => | |
939c12d2 | 4097 | if not Known_Null (R) then |
2ede092b RD |
4098 | return True; |
4099 | end if; | |
4100 | ||
4101 | when Division_Check => | |
4102 | if not Compile_Time_Known_Value (R) | |
4103 | or else Expr_Value (R) /= Uint_0 | |
4104 | then | |
4105 | return True; | |
4106 | end if; | |
939c12d2 RD |
4107 | |
4108 | when others => | |
4109 | raise Program_Error; | |
2ede092b RD |
4110 | end case; |
4111 | ||
4112 | -- Here we have the optimizable case, warn if not short-circuited | |
4113 | ||
4114 | if K = N_Op_And or else K = N_Op_Or then | |
43417b90 | 4115 | Error_Msg_Warn := SPARK_Mode /= On; |
4a28b181 | 4116 | |
2ede092b RD |
4117 | case Check is |
4118 | when Access_Check => | |
4a28b181 AC |
4119 | if GNATprove_Mode then |
4120 | Error_Msg_N | |
4121 | ("Constraint_Error might have been raised (access check)", | |
4122 | Parent (Nod)); | |
4123 | else | |
4124 | Error_Msg_N | |
4125 | ("Constraint_Error may be raised (access check)??", | |
4126 | Parent (Nod)); | |
4127 | end if; | |
4128 | ||
2ede092b | 4129 | when Division_Check => |
4a28b181 AC |
4130 | if GNATprove_Mode then |
4131 | Error_Msg_N | |
4132 | ("Constraint_Error might have been raised (zero divide)", | |
4133 | Parent (Nod)); | |
4134 | else | |
4135 | Error_Msg_N | |
4136 | ("Constraint_Error may be raised (zero divide)??", | |
4137 | Parent (Nod)); | |
4138 | end if; | |
939c12d2 RD |
4139 | |
4140 | when others => | |
4141 | raise Program_Error; | |
2ede092b RD |
4142 | end case; |
4143 | ||
4144 | if K = N_Op_And then | |
19d846a0 | 4145 | Error_Msg_N -- CODEFIX |
685bc70f | 4146 | ("use `AND THEN` instead of AND??", P); |
2ede092b | 4147 | else |
19d846a0 | 4148 | Error_Msg_N -- CODEFIX |
685bc70f | 4149 | ("use `OR ELSE` instead of OR??", P); |
2ede092b RD |
4150 | end if; |
4151 | ||
308e6f3a | 4152 | -- If not short-circuited, we need the check |
2ede092b RD |
4153 | |
4154 | return True; | |
4155 | ||
4156 | -- If short-circuited, we can omit the check | |
4157 | ||
4158 | else | |
4159 | return False; | |
4160 | end if; | |
4161 | end Check_Needed; | |
4162 | ||
70482933 RK |
4163 | ----------------------------------- |
4164 | -- Check_Valid_Lvalue_Subscripts -- | |
4165 | ----------------------------------- | |
4166 | ||
4167 | procedure Check_Valid_Lvalue_Subscripts (Expr : Node_Id) is | |
4168 | begin | |
4169 | -- Skip this if range checks are suppressed | |
4170 | ||
4171 | if Range_Checks_Suppressed (Etype (Expr)) then | |
4172 | return; | |
4173 | ||
675d6070 TQ |
4174 | -- Only do this check for expressions that come from source. We assume |
4175 | -- that expander generated assignments explicitly include any necessary | |
4176 | -- checks. Note that this is not just an optimization, it avoids | |
a90bd866 | 4177 | -- infinite recursions. |
70482933 RK |
4178 | |
4179 | elsif not Comes_From_Source (Expr) then | |
4180 | return; | |
4181 | ||
4182 | -- For a selected component, check the prefix | |
4183 | ||
4184 | elsif Nkind (Expr) = N_Selected_Component then | |
4185 | Check_Valid_Lvalue_Subscripts (Prefix (Expr)); | |
4186 | return; | |
4187 | ||
4188 | -- Case of indexed component | |
4189 | ||
4190 | elsif Nkind (Expr) = N_Indexed_Component then | |
4191 | Apply_Subscript_Validity_Checks (Expr); | |
4192 | ||
675d6070 TQ |
4193 | -- Prefix may itself be or contain an indexed component, and these |
4194 | -- subscripts need checking as well. | |
70482933 RK |
4195 | |
4196 | Check_Valid_Lvalue_Subscripts (Prefix (Expr)); | |
4197 | end if; | |
4198 | end Check_Valid_Lvalue_Subscripts; | |
4199 | ||
2820d220 AC |
4200 | ---------------------------------- |
4201 | -- Null_Exclusion_Static_Checks -- | |
4202 | ---------------------------------- | |
4203 | ||
d59179b1 | 4204 | procedure Null_Exclusion_Static_Checks |
62d40a7a AC |
4205 | (N : Node_Id; |
4206 | Comp : Node_Id := Empty; | |
4207 | Array_Comp : Boolean := False) | |
d59179b1 | 4208 | is |
97ac2d62 AC |
4209 | Has_Null : constant Boolean := Has_Null_Exclusion (N); |
4210 | Kind : constant Node_Kind := Nkind (N); | |
4211 | Error_Nod : Node_Id; | |
4212 | Expr : Node_Id; | |
4213 | Typ : Entity_Id; | |
2820d220 | 4214 | |
2ede092b | 4215 | begin |
c064e066 | 4216 | pragma Assert |
97ac2d62 AC |
4217 | (Nkind_In (Kind, N_Component_Declaration, |
4218 | N_Discriminant_Specification, | |
4219 | N_Function_Specification, | |
4220 | N_Object_Declaration, | |
4221 | N_Parameter_Specification)); | |
c064e066 | 4222 | |
97ac2d62 | 4223 | if Kind = N_Function_Specification then |
c064e066 RD |
4224 | Typ := Etype (Defining_Entity (N)); |
4225 | else | |
4226 | Typ := Etype (Defining_Identifier (N)); | |
4227 | end if; | |
2820d220 | 4228 | |
97ac2d62 | 4229 | case Kind is |
2ede092b RD |
4230 | when N_Component_Declaration => |
4231 | if Present (Access_Definition (Component_Definition (N))) then | |
97ac2d62 | 4232 | Error_Nod := Component_Definition (N); |
2ede092b | 4233 | else |
97ac2d62 | 4234 | Error_Nod := Subtype_Indication (Component_Definition (N)); |
2ede092b | 4235 | end if; |
7324bf49 | 4236 | |
c064e066 | 4237 | when N_Discriminant_Specification => |
97ac2d62 | 4238 | Error_Nod := Discriminant_Type (N); |
c064e066 RD |
4239 | |
4240 | when N_Function_Specification => | |
97ac2d62 | 4241 | Error_Nod := Result_Definition (N); |
c064e066 RD |
4242 | |
4243 | when N_Object_Declaration => | |
97ac2d62 | 4244 | Error_Nod := Object_Definition (N); |
c064e066 RD |
4245 | |
4246 | when N_Parameter_Specification => | |
97ac2d62 | 4247 | Error_Nod := Parameter_Type (N); |
c064e066 | 4248 | |
2ede092b RD |
4249 | when others => |
4250 | raise Program_Error; | |
4251 | end case; | |
7324bf49 | 4252 | |
c064e066 | 4253 | if Has_Null then |
7324bf49 | 4254 | |
c064e066 RD |
4255 | -- Enforce legality rule 3.10 (13): A null exclusion can only be |
4256 | -- applied to an access [sub]type. | |
7324bf49 | 4257 | |
c064e066 | 4258 | if not Is_Access_Type (Typ) then |
ed2233dc | 4259 | Error_Msg_N |
97ac2d62 | 4260 | ("`NOT NULL` allowed only for an access type", Error_Nod); |
7324bf49 | 4261 | |
675d6070 | 4262 | -- Enforce legality rule RM 3.10(14/1): A null exclusion can only |
c064e066 RD |
4263 | -- be applied to a [sub]type that does not exclude null already. |
4264 | ||
97ac2d62 | 4265 | elsif Can_Never_Be_Null (Typ) and then Comes_From_Source (Typ) then |
ed2233dc | 4266 | Error_Msg_NE |
11b4899f | 4267 | ("`NOT NULL` not allowed (& already excludes null)", |
97ac2d62 | 4268 | Error_Nod, Typ); |
c064e066 | 4269 | end if; |
2ede092b | 4270 | end if; |
7324bf49 | 4271 | |
f2cbd970 JM |
4272 | -- Check that null-excluding objects are always initialized, except for |
4273 | -- deferred constants, for which the expression will appear in the full | |
4274 | -- declaration. | |
2ede092b | 4275 | |
97ac2d62 | 4276 | if Kind = N_Object_Declaration |
86ac5e79 | 4277 | and then No (Expression (N)) |
f2cbd970 | 4278 | and then not Constant_Present (N) |
675d6070 | 4279 | and then not No_Initialization (N) |
2ede092b | 4280 | then |
d59179b1 AC |
4281 | if Present (Comp) then |
4282 | ||
31e358e1 | 4283 | -- Specialize the warning message to indicate that we are dealing |
d59179b1 AC |
4284 | -- with an uninitialized composite object that has a defaulted |
4285 | -- null-excluding component. | |
4286 | ||
4287 | Error_Msg_Name_1 := Chars (Defining_Identifier (Comp)); | |
4288 | Error_Msg_Name_2 := Chars (Defining_Identifier (N)); | |
4289 | ||
62d40a7a AC |
4290 | Discard_Node |
4291 | (Compile_Time_Constraint_Error | |
4292 | (N => N, | |
4293 | Msg => | |
4294 | "(Ada 2005) null-excluding component % of object % must " | |
4295 | & "be initialized??", | |
4296 | Ent => Defining_Identifier (Comp))); | |
4297 | ||
4298 | -- This is a case of an array with null-excluding components, so | |
4299 | -- indicate that in the warning. | |
4300 | ||
4301 | elsif Array_Comp then | |
4302 | Discard_Node | |
4303 | (Compile_Time_Constraint_Error | |
4304 | (N => N, | |
4305 | Msg => | |
4306 | "(Ada 2005) null-excluding array components must " | |
4307 | & "be initialized??", | |
4308 | Ent => Defining_Identifier (N))); | |
4309 | ||
4310 | -- Normal case of object of a null-excluding access type | |
31e358e1 | 4311 | |
d59179b1 | 4312 | else |
62d40a7a AC |
4313 | -- Add an expression that assigns null. This node is needed by |
4314 | -- Apply_Compile_Time_Constraint_Error, which will replace this | |
4315 | -- with a Constraint_Error node. | |
4316 | ||
4317 | Set_Expression (N, Make_Null (Sloc (N))); | |
4318 | Set_Etype (Expression (N), Etype (Defining_Identifier (N))); | |
4319 | ||
d59179b1 AC |
4320 | Apply_Compile_Time_Constraint_Error |
4321 | (N => Expression (N), | |
4322 | Msg => | |
4323 | "(Ada 2005) null-excluding objects must be initialized??", | |
4324 | Reason => CE_Null_Not_Allowed); | |
4325 | end if; | |
2ede092b | 4326 | end if; |
7324bf49 | 4327 | |
f2cbd970 JM |
4328 | -- Check that a null-excluding component, formal or object is not being |
4329 | -- assigned a null value. Otherwise generate a warning message and | |
f3d0f304 | 4330 | -- replace Expression (N) by an N_Constraint_Error node. |
2ede092b | 4331 | |
97ac2d62 | 4332 | if Kind /= N_Function_Specification then |
c064e066 | 4333 | Expr := Expression (N); |
7324bf49 | 4334 | |
939c12d2 | 4335 | if Present (Expr) and then Known_Null (Expr) then |
97ac2d62 | 4336 | case Kind is |
d8f43ee6 HK |
4337 | when N_Component_Declaration |
4338 | | N_Discriminant_Specification | |
4339 | => | |
82c80734 | 4340 | Apply_Compile_Time_Constraint_Error |
c064e066 | 4341 | (N => Expr, |
d8f43ee6 HK |
4342 | Msg => |
4343 | "(Ada 2005) null not allowed in null-excluding " | |
4344 | & "components??", | |
c064e066 | 4345 | Reason => CE_Null_Not_Allowed); |
7324bf49 | 4346 | |
c064e066 | 4347 | when N_Object_Declaration => |
82c80734 | 4348 | Apply_Compile_Time_Constraint_Error |
c064e066 | 4349 | (N => Expr, |
d8f43ee6 HK |
4350 | Msg => |
4351 | "(Ada 2005) null not allowed in null-excluding " | |
4352 | & "objects??", | |
c064e066 | 4353 | Reason => CE_Null_Not_Allowed); |
7324bf49 | 4354 | |
c064e066 | 4355 | when N_Parameter_Specification => |
82c80734 | 4356 | Apply_Compile_Time_Constraint_Error |
c064e066 | 4357 | (N => Expr, |
d8f43ee6 HK |
4358 | Msg => |
4359 | "(Ada 2005) null not allowed in null-excluding " | |
4360 | & "formals??", | |
c064e066 | 4361 | Reason => CE_Null_Not_Allowed); |
2ede092b RD |
4362 | |
4363 | when others => | |
4364 | null; | |
7324bf49 AC |
4365 | end case; |
4366 | end if; | |
c064e066 | 4367 | end if; |
2820d220 AC |
4368 | end Null_Exclusion_Static_Checks; |
4369 | ||
fbf5a39b AC |
4370 | ---------------------------------- |
4371 | -- Conditional_Statements_Begin -- | |
4372 | ---------------------------------- | |
4373 | ||
4374 | procedure Conditional_Statements_Begin is | |
4375 | begin | |
4376 | Saved_Checks_TOS := Saved_Checks_TOS + 1; | |
4377 | ||
675d6070 TQ |
4378 | -- If stack overflows, kill all checks, that way we know to simply reset |
4379 | -- the number of saved checks to zero on return. This should never occur | |
4380 | -- in practice. | |
fbf5a39b AC |
4381 | |
4382 | if Saved_Checks_TOS > Saved_Checks_Stack'Last then | |
4383 | Kill_All_Checks; | |
4384 | ||
675d6070 TQ |
4385 | -- In the normal case, we just make a new stack entry saving the current |
4386 | -- number of saved checks for a later restore. | |
fbf5a39b AC |
4387 | |
4388 | else | |
4389 | Saved_Checks_Stack (Saved_Checks_TOS) := Num_Saved_Checks; | |
4390 | ||
4391 | if Debug_Flag_CC then | |
4392 | w ("Conditional_Statements_Begin: Num_Saved_Checks = ", | |
4393 | Num_Saved_Checks); | |
4394 | end if; | |
4395 | end if; | |
4396 | end Conditional_Statements_Begin; | |
4397 | ||
4398 | -------------------------------- | |
4399 | -- Conditional_Statements_End -- | |
4400 | -------------------------------- | |
4401 | ||
4402 | procedure Conditional_Statements_End is | |
4403 | begin | |
4404 | pragma Assert (Saved_Checks_TOS > 0); | |
4405 | ||
675d6070 TQ |
4406 | -- If the saved checks stack overflowed, then we killed all checks, so |
4407 | -- setting the number of saved checks back to zero is correct. This | |
4408 | -- should never occur in practice. | |
fbf5a39b AC |
4409 | |
4410 | if Saved_Checks_TOS > Saved_Checks_Stack'Last then | |
4411 | Num_Saved_Checks := 0; | |
4412 | ||
675d6070 TQ |
4413 | -- In the normal case, restore the number of saved checks from the top |
4414 | -- stack entry. | |
fbf5a39b AC |
4415 | |
4416 | else | |
4417 | Num_Saved_Checks := Saved_Checks_Stack (Saved_Checks_TOS); | |
637a41a5 | 4418 | |
fbf5a39b AC |
4419 | if Debug_Flag_CC then |
4420 | w ("Conditional_Statements_End: Num_Saved_Checks = ", | |
4421 | Num_Saved_Checks); | |
4422 | end if; | |
4423 | end if; | |
4424 | ||
4425 | Saved_Checks_TOS := Saved_Checks_TOS - 1; | |
4426 | end Conditional_Statements_End; | |
4427 | ||
acad3c0a AC |
4428 | ------------------------- |
4429 | -- Convert_From_Bignum -- | |
4430 | ------------------------- | |
4431 | ||
4432 | function Convert_From_Bignum (N : Node_Id) return Node_Id is | |
4433 | Loc : constant Source_Ptr := Sloc (N); | |
4434 | ||
4435 | begin | |
4436 | pragma Assert (Is_RTE (Etype (N), RE_Bignum)); | |
4437 | ||
4438 | -- Construct call From Bignum | |
4439 | ||
4440 | return | |
4441 | Make_Function_Call (Loc, | |
4442 | Name => | |
4443 | New_Occurrence_Of (RTE (RE_From_Bignum), Loc), | |
4444 | Parameter_Associations => New_List (Relocate_Node (N))); | |
4445 | end Convert_From_Bignum; | |
4446 | ||
4447 | ----------------------- | |
4448 | -- Convert_To_Bignum -- | |
4449 | ----------------------- | |
4450 | ||
4451 | function Convert_To_Bignum (N : Node_Id) return Node_Id is | |
4452 | Loc : constant Source_Ptr := Sloc (N); | |
4453 | ||
4454 | begin | |
4b1c4f20 | 4455 | -- Nothing to do if Bignum already except call Relocate_Node |
acad3c0a AC |
4456 | |
4457 | if Is_RTE (Etype (N), RE_Bignum) then | |
4458 | return Relocate_Node (N); | |
4459 | ||
5707e389 AC |
4460 | -- Otherwise construct call to To_Bignum, converting the operand to the |
4461 | -- required Long_Long_Integer form. | |
acad3c0a AC |
4462 | |
4463 | else | |
4464 | pragma Assert (Is_Signed_Integer_Type (Etype (N))); | |
4465 | return | |
4466 | Make_Function_Call (Loc, | |
4467 | Name => | |
4468 | New_Occurrence_Of (RTE (RE_To_Bignum), Loc), | |
4469 | Parameter_Associations => New_List ( | |
4470 | Convert_To (Standard_Long_Long_Integer, Relocate_Node (N)))); | |
4471 | end if; | |
4472 | end Convert_To_Bignum; | |
4473 | ||
70482933 RK |
4474 | --------------------- |
4475 | -- Determine_Range -- | |
4476 | --------------------- | |
4477 | ||
c9a4817d | 4478 | Cache_Size : constant := 2 ** 10; |
70482933 | 4479 | type Cache_Index is range 0 .. Cache_Size - 1; |
a90bd866 | 4480 | -- Determine size of below cache (power of 2 is more efficient) |
70482933 | 4481 | |
6b6bce61 AC |
4482 | Determine_Range_Cache_N : array (Cache_Index) of Node_Id; |
4483 | Determine_Range_Cache_V : array (Cache_Index) of Boolean; | |
4484 | Determine_Range_Cache_Lo : array (Cache_Index) of Uint; | |
4485 | Determine_Range_Cache_Hi : array (Cache_Index) of Uint; | |
4486 | Determine_Range_Cache_Lo_R : array (Cache_Index) of Ureal; | |
4487 | Determine_Range_Cache_Hi_R : array (Cache_Index) of Ureal; | |
675d6070 | 4488 | -- The above arrays are used to implement a small direct cache for |
6b6bce61 AC |
4489 | -- Determine_Range and Determine_Range_R calls. Because of the way these |
4490 | -- subprograms recursively traces subexpressions, and because overflow | |
4491 | -- checking calls the routine on the way up the tree, a quadratic behavior | |
4492 | -- can otherwise be encountered in large expressions. The cache entry for | |
4493 | -- node N is stored in the (N mod Cache_Size) entry, and can be validated | |
4494 | -- by checking the actual node value stored there. The Range_Cache_V array | |
4495 | -- records the setting of Assume_Valid for the cache entry. | |
70482933 RK |
4496 | |
4497 | procedure Determine_Range | |
c800f862 RD |
4498 | (N : Node_Id; |
4499 | OK : out Boolean; | |
4500 | Lo : out Uint; | |
4501 | Hi : out Uint; | |
4502 | Assume_Valid : Boolean := False) | |
70482933 | 4503 | is |
1c7717c3 AC |
4504 | Typ : Entity_Id := Etype (N); |
4505 | -- Type to use, may get reset to base type for possibly invalid entity | |
c1c22e7a GB |
4506 | |
4507 | Lo_Left : Uint; | |
4508 | Hi_Left : Uint; | |
4509 | -- Lo and Hi bounds of left operand | |
70482933 | 4510 | |
dcd5fd67 PMR |
4511 | Lo_Right : Uint := No_Uint; |
4512 | Hi_Right : Uint := No_Uint; | |
c1c22e7a GB |
4513 | -- Lo and Hi bounds of right (or only) operand |
4514 | ||
4515 | Bound : Node_Id; | |
4516 | -- Temp variable used to hold a bound node | |
4517 | ||
4518 | Hbound : Uint; | |
4519 | -- High bound of base type of expression | |
4520 | ||
4521 | Lor : Uint; | |
4522 | Hir : Uint; | |
4523 | -- Refined values for low and high bounds, after tightening | |
4524 | ||
4525 | OK1 : Boolean; | |
4526 | -- Used in lower level calls to indicate if call succeeded | |
4527 | ||
4528 | Cindex : Cache_Index; | |
4529 | -- Used to search cache | |
70482933 | 4530 | |
d7a44b14 AC |
4531 | Btyp : Entity_Id; |
4532 | -- Base type | |
4533 | ||
70482933 RK |
4534 | function OK_Operands return Boolean; |
4535 | -- Used for binary operators. Determines the ranges of the left and | |
4536 | -- right operands, and if they are both OK, returns True, and puts | |
93c3fca7 | 4537 | -- the results in Lo_Right, Hi_Right, Lo_Left, Hi_Left. |
70482933 RK |
4538 | |
4539 | ----------------- | |
4540 | -- OK_Operands -- | |
4541 | ----------------- | |
4542 | ||
4543 | function OK_Operands return Boolean is | |
4544 | begin | |
c800f862 RD |
4545 | Determine_Range |
4546 | (Left_Opnd (N), OK1, Lo_Left, Hi_Left, Assume_Valid); | |
70482933 RK |
4547 | |
4548 | if not OK1 then | |
4549 | return False; | |
4550 | end if; | |
4551 | ||
c800f862 RD |
4552 | Determine_Range |
4553 | (Right_Opnd (N), OK1, Lo_Right, Hi_Right, Assume_Valid); | |
70482933 RK |
4554 | return OK1; |
4555 | end OK_Operands; | |
4556 | ||
4557 | -- Start of processing for Determine_Range | |
4558 | ||
4559 | begin | |
3e65bfab AC |
4560 | -- Prevent junk warnings by initializing range variables |
4561 | ||
4562 | Lo := No_Uint; | |
4563 | Hi := No_Uint; | |
4564 | Lor := No_Uint; | |
4565 | Hir := No_Uint; | |
4566 | ||
62be5d0a JM |
4567 | -- For temporary constants internally generated to remove side effects |
4568 | -- we must use the corresponding expression to determine the range of | |
3e65bfab AC |
4569 | -- the expression. But note that the expander can also generate |
4570 | -- constants in other cases, including deferred constants. | |
62be5d0a JM |
4571 | |
4572 | if Is_Entity_Name (N) | |
4573 | and then Nkind (Parent (Entity (N))) = N_Object_Declaration | |
4574 | and then Ekind (Entity (N)) = E_Constant | |
4575 | and then Is_Internal_Name (Chars (Entity (N))) | |
4576 | then | |
3e65bfab AC |
4577 | if Present (Expression (Parent (Entity (N)))) then |
4578 | Determine_Range | |
4579 | (Expression (Parent (Entity (N))), OK, Lo, Hi, Assume_Valid); | |
62be5d0a | 4580 | |
3e65bfab AC |
4581 | elsif Present (Full_View (Entity (N))) then |
4582 | Determine_Range | |
4583 | (Expression (Parent (Full_View (Entity (N)))), | |
4584 | OK, Lo, Hi, Assume_Valid); | |
70482933 | 4585 | |
3e65bfab AC |
4586 | else |
4587 | OK := False; | |
4588 | end if; | |
4589 | return; | |
4590 | end if; | |
70482933 | 4591 | |
1abad480 | 4592 | -- If type is not defined, we can't determine its range |
70482933 | 4593 | |
1abad480 AC |
4594 | if No (Typ) |
4595 | ||
4596 | -- We don't deal with anything except discrete types | |
4597 | ||
4598 | or else not Is_Discrete_Type (Typ) | |
4599 | ||
f20b5ef4 JM |
4600 | -- Don't deal with enumerated types with non-standard representation |
4601 | ||
4602 | or else (Is_Enumeration_Type (Typ) | |
4603 | and then Present (Enum_Pos_To_Rep (Base_Type (Typ)))) | |
4604 | ||
1abad480 AC |
4605 | -- Ignore type for which an error has been posted, since range in |
4606 | -- this case may well be a bogosity deriving from the error. Also | |
4607 | -- ignore if error posted on the reference node. | |
4608 | ||
4609 | or else Error_Posted (N) or else Error_Posted (Typ) | |
70482933 RK |
4610 | then |
4611 | OK := False; | |
4612 | return; | |
4613 | end if; | |
4614 | ||
4615 | -- For all other cases, we can determine the range | |
4616 | ||
4617 | OK := True; | |
4618 | ||
675d6070 | 4619 | -- If value is compile time known, then the possible range is the one |
a90bd866 | 4620 | -- value that we know this expression definitely has. |
70482933 RK |
4621 | |
4622 | if Compile_Time_Known_Value (N) then | |
4623 | Lo := Expr_Value (N); | |
4624 | Hi := Lo; | |
4625 | return; | |
4626 | end if; | |
4627 | ||
4628 | -- Return if already in the cache | |
4629 | ||
4630 | Cindex := Cache_Index (N mod Cache_Size); | |
4631 | ||
c800f862 RD |
4632 | if Determine_Range_Cache_N (Cindex) = N |
4633 | and then | |
4634 | Determine_Range_Cache_V (Cindex) = Assume_Valid | |
4635 | then | |
70482933 RK |
4636 | Lo := Determine_Range_Cache_Lo (Cindex); |
4637 | Hi := Determine_Range_Cache_Hi (Cindex); | |
4638 | return; | |
4639 | end if; | |
4640 | ||
675d6070 TQ |
4641 | -- Otherwise, start by finding the bounds of the type of the expression, |
4642 | -- the value cannot be outside this range (if it is, then we have an | |
4643 | -- overflow situation, which is a separate check, we are talking here | |
4644 | -- only about the expression value). | |
70482933 | 4645 | |
93c3fca7 AC |
4646 | -- First a check, never try to find the bounds of a generic type, since |
4647 | -- these bounds are always junk values, and it is only valid to look at | |
4648 | -- the bounds in an instance. | |
4649 | ||
4650 | if Is_Generic_Type (Typ) then | |
4651 | OK := False; | |
4652 | return; | |
4653 | end if; | |
4654 | ||
c800f862 | 4655 | -- First step, change to use base type unless we know the value is valid |
1c7717c3 | 4656 | |
c800f862 RD |
4657 | if (Is_Entity_Name (N) and then Is_Known_Valid (Entity (N))) |
4658 | or else Assume_No_Invalid_Values | |
4659 | or else Assume_Valid | |
1c7717c3 | 4660 | then |
43018f58 ES |
4661 | -- If this is a known valid constant with a nonstatic value, it may |
4662 | -- have inherited a narrower subtype from its initial value; use this | |
4663 | -- saved subtype (see sem_ch3.adb). | |
4664 | ||
4665 | if Is_Entity_Name (N) | |
4666 | and then Ekind (Entity (N)) = E_Constant | |
4667 | and then Present (Actual_Subtype (Entity (N))) | |
4668 | then | |
4669 | Typ := Actual_Subtype (Entity (N)); | |
4670 | end if; | |
4671 | ||
c800f862 RD |
4672 | else |
4673 | Typ := Underlying_Type (Base_Type (Typ)); | |
1c7717c3 AC |
4674 | end if; |
4675 | ||
d7a44b14 AC |
4676 | -- Retrieve the base type. Handle the case where the base type is a |
4677 | -- private enumeration type. | |
4678 | ||
4679 | Btyp := Base_Type (Typ); | |
4680 | ||
4681 | if Is_Private_Type (Btyp) and then Present (Full_View (Btyp)) then | |
4682 | Btyp := Full_View (Btyp); | |
4683 | end if; | |
4684 | ||
675d6070 TQ |
4685 | -- We use the actual bound unless it is dynamic, in which case use the |
4686 | -- corresponding base type bound if possible. If we can't get a bound | |
4687 | -- then we figure we can't determine the range (a peculiar case, that | |
4688 | -- perhaps cannot happen, but there is no point in bombing in this | |
4689 | -- optimization circuit. | |
c1c22e7a GB |
4690 | |
4691 | -- First the low bound | |
70482933 RK |
4692 | |
4693 | Bound := Type_Low_Bound (Typ); | |
4694 | ||
4695 | if Compile_Time_Known_Value (Bound) then | |
4696 | Lo := Expr_Value (Bound); | |
4697 | ||
d7a44b14 AC |
4698 | elsif Compile_Time_Known_Value (Type_Low_Bound (Btyp)) then |
4699 | Lo := Expr_Value (Type_Low_Bound (Btyp)); | |
70482933 RK |
4700 | |
4701 | else | |
4702 | OK := False; | |
4703 | return; | |
4704 | end if; | |
4705 | ||
c1c22e7a GB |
4706 | -- Now the high bound |
4707 | ||
70482933 RK |
4708 | Bound := Type_High_Bound (Typ); |
4709 | ||
c1c22e7a GB |
4710 | -- We need the high bound of the base type later on, and this should |
4711 | -- always be compile time known. Again, it is not clear that this | |
4712 | -- can ever be false, but no point in bombing. | |
70482933 | 4713 | |
d7a44b14 AC |
4714 | if Compile_Time_Known_Value (Type_High_Bound (Btyp)) then |
4715 | Hbound := Expr_Value (Type_High_Bound (Btyp)); | |
70482933 RK |
4716 | Hi := Hbound; |
4717 | ||
4718 | else | |
4719 | OK := False; | |
4720 | return; | |
4721 | end if; | |
4722 | ||
675d6070 TQ |
4723 | -- If we have a static subtype, then that may have a tighter bound so |
4724 | -- use the upper bound of the subtype instead in this case. | |
c1c22e7a GB |
4725 | |
4726 | if Compile_Time_Known_Value (Bound) then | |
4727 | Hi := Expr_Value (Bound); | |
4728 | end if; | |
4729 | ||
675d6070 TQ |
4730 | -- We may be able to refine this value in certain situations. If any |
4731 | -- refinement is possible, then Lor and Hir are set to possibly tighter | |
4732 | -- bounds, and OK1 is set to True. | |
70482933 RK |
4733 | |
4734 | case Nkind (N) is | |
4735 | ||
4736 | -- For unary plus, result is limited by range of operand | |
4737 | ||
4738 | when N_Op_Plus => | |
c800f862 RD |
4739 | Determine_Range |
4740 | (Right_Opnd (N), OK1, Lor, Hir, Assume_Valid); | |
70482933 RK |
4741 | |
4742 | -- For unary minus, determine range of operand, and negate it | |
4743 | ||
4744 | when N_Op_Minus => | |
c800f862 RD |
4745 | Determine_Range |
4746 | (Right_Opnd (N), OK1, Lo_Right, Hi_Right, Assume_Valid); | |
70482933 RK |
4747 | |
4748 | if OK1 then | |
4749 | Lor := -Hi_Right; | |
4750 | Hir := -Lo_Right; | |
4751 | end if; | |
4752 | ||
4753 | -- For binary addition, get range of each operand and do the | |
4754 | -- addition to get the result range. | |
4755 | ||
4756 | when N_Op_Add => | |
4757 | if OK_Operands then | |
4758 | Lor := Lo_Left + Lo_Right; | |
4759 | Hir := Hi_Left + Hi_Right; | |
4760 | end if; | |
4761 | ||
675d6070 TQ |
4762 | -- Division is tricky. The only case we consider is where the right |
4763 | -- operand is a positive constant, and in this case we simply divide | |
4764 | -- the bounds of the left operand | |
70482933 RK |
4765 | |
4766 | when N_Op_Divide => | |
4767 | if OK_Operands then | |
4768 | if Lo_Right = Hi_Right | |
4769 | and then Lo_Right > 0 | |
4770 | then | |
4771 | Lor := Lo_Left / Lo_Right; | |
4772 | Hir := Hi_Left / Lo_Right; | |
70482933 RK |
4773 | else |
4774 | OK1 := False; | |
4775 | end if; | |
4776 | end if; | |
4777 | ||
675d6070 TQ |
4778 | -- For binary subtraction, get range of each operand and do the worst |
4779 | -- case subtraction to get the result range. | |
70482933 RK |
4780 | |
4781 | when N_Op_Subtract => | |
4782 | if OK_Operands then | |
4783 | Lor := Lo_Left - Hi_Right; | |
4784 | Hir := Hi_Left - Lo_Right; | |
4785 | end if; | |
4786 | ||
675d6070 TQ |
4787 | -- For MOD, if right operand is a positive constant, then result must |
4788 | -- be in the allowable range of mod results. | |
70482933 RK |
4789 | |
4790 | when N_Op_Mod => | |
4791 | if OK_Operands then | |
fbf5a39b AC |
4792 | if Lo_Right = Hi_Right |
4793 | and then Lo_Right /= 0 | |
4794 | then | |
70482933 RK |
4795 | if Lo_Right > 0 then |
4796 | Lor := Uint_0; | |
4797 | Hir := Lo_Right - 1; | |
4798 | ||
fbf5a39b | 4799 | else -- Lo_Right < 0 |
70482933 RK |
4800 | Lor := Lo_Right + 1; |
4801 | Hir := Uint_0; | |
4802 | end if; | |
4803 | ||
4804 | else | |
4805 | OK1 := False; | |
4806 | end if; | |
4807 | end if; | |
4808 | ||
675d6070 TQ |
4809 | -- For REM, if right operand is a positive constant, then result must |
4810 | -- be in the allowable range of mod results. | |
70482933 RK |
4811 | |
4812 | when N_Op_Rem => | |
4813 | if OK_Operands then | |
d8f43ee6 | 4814 | if Lo_Right = Hi_Right and then Lo_Right /= 0 then |
70482933 RK |
4815 | declare |
4816 | Dval : constant Uint := (abs Lo_Right) - 1; | |
4817 | ||
4818 | begin | |
4819 | -- The sign of the result depends on the sign of the | |
4820 | -- dividend (but not on the sign of the divisor, hence | |
4821 | -- the abs operation above). | |
4822 | ||
4823 | if Lo_Left < 0 then | |
4824 | Lor := -Dval; | |
4825 | else | |
4826 | Lor := Uint_0; | |
4827 | end if; | |
4828 | ||
4829 | if Hi_Left < 0 then | |
4830 | Hir := Uint_0; | |
4831 | else | |
4832 | Hir := Dval; | |
4833 | end if; | |
4834 | end; | |
4835 | ||
4836 | else | |
4837 | OK1 := False; | |
4838 | end if; | |
4839 | end if; | |
4840 | ||
4841 | -- Attribute reference cases | |
4842 | ||
4843 | when N_Attribute_Reference => | |
4844 | case Attribute_Name (N) is | |
4845 | ||
4846 | -- For Pos/Val attributes, we can refine the range using the | |
f26d5cd3 | 4847 | -- possible range of values of the attribute expression. |
70482933 | 4848 | |
d8f43ee6 HK |
4849 | when Name_Pos |
4850 | | Name_Val | |
4851 | => | |
c800f862 RD |
4852 | Determine_Range |
4853 | (First (Expressions (N)), OK1, Lor, Hir, Assume_Valid); | |
70482933 RK |
4854 | |
4855 | -- For Length attribute, use the bounds of the corresponding | |
4856 | -- index type to refine the range. | |
4857 | ||
4858 | when Name_Length => | |
4859 | declare | |
4860 | Atyp : Entity_Id := Etype (Prefix (N)); | |
4861 | Inum : Nat; | |
4862 | Indx : Node_Id; | |
4863 | ||
4864 | LL, LU : Uint; | |
4865 | UL, UU : Uint; | |
4866 | ||
4867 | begin | |
4868 | if Is_Access_Type (Atyp) then | |
4869 | Atyp := Designated_Type (Atyp); | |
4870 | end if; | |
4871 | ||
4872 | -- For string literal, we know exact value | |
4873 | ||
4874 | if Ekind (Atyp) = E_String_Literal_Subtype then | |
4875 | OK := True; | |
4876 | Lo := String_Literal_Length (Atyp); | |
4877 | Hi := String_Literal_Length (Atyp); | |
4878 | return; | |
4879 | end if; | |
4880 | ||
4881 | -- Otherwise check for expression given | |
4882 | ||
4883 | if No (Expressions (N)) then | |
4884 | Inum := 1; | |
4885 | else | |
4886 | Inum := | |
4887 | UI_To_Int (Expr_Value (First (Expressions (N)))); | |
4888 | end if; | |
4889 | ||
4890 | Indx := First_Index (Atyp); | |
4891 | for J in 2 .. Inum loop | |
4892 | Indx := Next_Index (Indx); | |
4893 | end loop; | |
4894 | ||
5b599df4 | 4895 | -- If the index type is a formal type or derived from |
b4d7b435 AC |
4896 | -- one, the bounds are not static. |
4897 | ||
4898 | if Is_Generic_Type (Root_Type (Etype (Indx))) then | |
4899 | OK := False; | |
4900 | return; | |
4901 | end if; | |
4902 | ||
70482933 | 4903 | Determine_Range |
c800f862 RD |
4904 | (Type_Low_Bound (Etype (Indx)), OK1, LL, LU, |
4905 | Assume_Valid); | |
70482933 RK |
4906 | |
4907 | if OK1 then | |
4908 | Determine_Range | |
c800f862 RD |
4909 | (Type_High_Bound (Etype (Indx)), OK1, UL, UU, |
4910 | Assume_Valid); | |
70482933 RK |
4911 | |
4912 | if OK1 then | |
4913 | ||
4914 | -- The maximum value for Length is the biggest | |
4915 | -- possible gap between the values of the bounds. | |
4916 | -- But of course, this value cannot be negative. | |
4917 | ||
c800f862 | 4918 | Hir := UI_Max (Uint_0, UU - LL + 1); |
70482933 RK |
4919 | |
4920 | -- For constrained arrays, the minimum value for | |
4921 | -- Length is taken from the actual value of the | |
5b599df4 AC |
4922 | -- bounds, since the index will be exactly of this |
4923 | -- subtype. | |
70482933 RK |
4924 | |
4925 | if Is_Constrained (Atyp) then | |
c800f862 | 4926 | Lor := UI_Max (Uint_0, UL - LU + 1); |
70482933 RK |
4927 | |
4928 | -- For an unconstrained array, the minimum value | |
4929 | -- for length is always zero. | |
4930 | ||
4931 | else | |
4932 | Lor := Uint_0; | |
4933 | end if; | |
4934 | end if; | |
4935 | end if; | |
4936 | end; | |
4937 | ||
4938 | -- No special handling for other attributes | |
5b599df4 | 4939 | -- Probably more opportunities exist here??? |
70482933 RK |
4940 | |
4941 | when others => | |
4942 | OK1 := False; | |
4943 | ||
4944 | end case; | |
4945 | ||
70482933 | 4946 | when N_Type_Conversion => |
d8ee014f YM |
4947 | |
4948 | -- For type conversion from one discrete type to another, we can | |
4949 | -- refine the range using the converted value. | |
4950 | ||
4951 | if Is_Discrete_Type (Etype (Expression (N))) then | |
4952 | Determine_Range (Expression (N), OK1, Lor, Hir, Assume_Valid); | |
4953 | ||
4954 | -- When converting a float to an integer type, determine the range | |
4955 | -- in real first, and then convert the bounds using UR_To_Uint | |
4956 | -- which correctly rounds away from zero when half way between two | |
4957 | -- integers, as required by normal Ada 95 rounding semantics. It | |
4958 | -- is only possible because analysis in GNATprove rules out the | |
4959 | -- possibility of a NaN or infinite value. | |
4960 | ||
4961 | elsif GNATprove_Mode | |
4962 | and then Is_Floating_Point_Type (Etype (Expression (N))) | |
4963 | then | |
4964 | declare | |
4965 | Lor_Real, Hir_Real : Ureal; | |
4966 | begin | |
4967 | Determine_Range_R (Expression (N), OK1, Lor_Real, Hir_Real, | |
4968 | Assume_Valid); | |
4969 | ||
4970 | if OK1 then | |
4971 | Lor := UR_To_Uint (Lor_Real); | |
4972 | Hir := UR_To_Uint (Hir_Real); | |
4973 | end if; | |
4974 | end; | |
4975 | ||
4976 | else | |
4977 | OK1 := False; | |
4978 | end if; | |
70482933 RK |
4979 | |
4980 | -- Nothing special to do for all other expression kinds | |
4981 | ||
4982 | when others => | |
4983 | OK1 := False; | |
4984 | Lor := No_Uint; | |
4985 | Hir := No_Uint; | |
4986 | end case; | |
4987 | ||
5b599df4 AC |
4988 | -- At this stage, if OK1 is true, then we know that the actual result of |
4989 | -- the computed expression is in the range Lor .. Hir. We can use this | |
4990 | -- to restrict the possible range of results. | |
70482933 RK |
4991 | |
4992 | if OK1 then | |
4993 | ||
5b599df4 | 4994 | -- If the refined value of the low bound is greater than the type |
6b6bce61 | 4995 | -- low bound, then reset it to the more restrictive value. However, |
5b599df4 AC |
4996 | -- we do NOT do this for the case of a modular type where the |
4997 | -- possible upper bound on the value is above the base type high | |
4998 | -- bound, because that means the result could wrap. | |
70482933 RK |
4999 | |
5000 | if Lor > Lo | |
5b599df4 | 5001 | and then not (Is_Modular_Integer_Type (Typ) and then Hir > Hbound) |
70482933 RK |
5002 | then |
5003 | Lo := Lor; | |
5004 | end if; | |
5005 | ||
5b599df4 AC |
5006 | -- Similarly, if the refined value of the high bound is less than the |
5007 | -- value so far, then reset it to the more restrictive value. Again, | |
5008 | -- we do not do this if the refined low bound is negative for a | |
5009 | -- modular type, since this would wrap. | |
70482933 RK |
5010 | |
5011 | if Hir < Hi | |
5b599df4 | 5012 | and then not (Is_Modular_Integer_Type (Typ) and then Lor < Uint_0) |
70482933 RK |
5013 | then |
5014 | Hi := Hir; | |
5015 | end if; | |
5016 | end if; | |
5017 | ||
5018 | -- Set cache entry for future call and we are all done | |
5019 | ||
5020 | Determine_Range_Cache_N (Cindex) := N; | |
c800f862 | 5021 | Determine_Range_Cache_V (Cindex) := Assume_Valid; |
70482933 RK |
5022 | Determine_Range_Cache_Lo (Cindex) := Lo; |
5023 | Determine_Range_Cache_Hi (Cindex) := Hi; | |
5024 | return; | |
5025 | ||
5b599df4 AC |
5026 | -- If any exception occurs, it means that we have some bug in the compiler, |
5027 | -- possibly triggered by a previous error, or by some unforeseen peculiar | |
70482933 RK |
5028 | -- occurrence. However, this is only an optimization attempt, so there is |
5029 | -- really no point in crashing the compiler. Instead we just decide, too | |
5030 | -- bad, we can't figure out a range in this case after all. | |
5031 | ||
5032 | exception | |
5033 | when others => | |
5034 | ||
5035 | -- Debug flag K disables this behavior (useful for debugging) | |
5036 | ||
5037 | if Debug_Flag_K then | |
5038 | raise; | |
5039 | else | |
5040 | OK := False; | |
5041 | Lo := No_Uint; | |
5042 | Hi := No_Uint; | |
5043 | return; | |
5044 | end if; | |
70482933 RK |
5045 | end Determine_Range; |
5046 | ||
6b6bce61 AC |
5047 | ----------------------- |
5048 | -- Determine_Range_R -- | |
5049 | ----------------------- | |
5050 | ||
5051 | procedure Determine_Range_R | |
5052 | (N : Node_Id; | |
5053 | OK : out Boolean; | |
5054 | Lo : out Ureal; | |
5055 | Hi : out Ureal; | |
5056 | Assume_Valid : Boolean := False) | |
5057 | is | |
5058 | Typ : Entity_Id := Etype (N); | |
5059 | -- Type to use, may get reset to base type for possibly invalid entity | |
5060 | ||
5061 | Lo_Left : Ureal; | |
5062 | Hi_Left : Ureal; | |
5063 | -- Lo and Hi bounds of left operand | |
5064 | ||
dcd5fd67 PMR |
5065 | Lo_Right : Ureal := No_Ureal; |
5066 | Hi_Right : Ureal := No_Ureal; | |
6b6bce61 AC |
5067 | -- Lo and Hi bounds of right (or only) operand |
5068 | ||
5069 | Bound : Node_Id; | |
5070 | -- Temp variable used to hold a bound node | |
5071 | ||
5072 | Hbound : Ureal; | |
5073 | -- High bound of base type of expression | |
5074 | ||
5075 | Lor : Ureal; | |
5076 | Hir : Ureal; | |
5077 | -- Refined values for low and high bounds, after tightening | |
5078 | ||
5079 | OK1 : Boolean; | |
5080 | -- Used in lower level calls to indicate if call succeeded | |
5081 | ||
5082 | Cindex : Cache_Index; | |
5083 | -- Used to search cache | |
5084 | ||
5085 | Btyp : Entity_Id; | |
5086 | -- Base type | |
5087 | ||
5088 | function OK_Operands return Boolean; | |
5089 | -- Used for binary operators. Determines the ranges of the left and | |
5090 | -- right operands, and if they are both OK, returns True, and puts | |
5091 | -- the results in Lo_Right, Hi_Right, Lo_Left, Hi_Left. | |
5092 | ||
5093 | function Round_Machine (B : Ureal) return Ureal; | |
5094 | -- B is a real bound. Round it using mode Round_Even. | |
5095 | ||
5096 | ----------------- | |
5097 | -- OK_Operands -- | |
5098 | ----------------- | |
5099 | ||
5100 | function OK_Operands return Boolean is | |
5101 | begin | |
5102 | Determine_Range_R | |
5103 | (Left_Opnd (N), OK1, Lo_Left, Hi_Left, Assume_Valid); | |
5104 | ||
5105 | if not OK1 then | |
5106 | return False; | |
5107 | end if; | |
5108 | ||
5109 | Determine_Range_R | |
5110 | (Right_Opnd (N), OK1, Lo_Right, Hi_Right, Assume_Valid); | |
5111 | return OK1; | |
5112 | end OK_Operands; | |
5113 | ||
5114 | ------------------- | |
5115 | -- Round_Machine -- | |
5116 | ------------------- | |
5117 | ||
5118 | function Round_Machine (B : Ureal) return Ureal is | |
5119 | begin | |
5120 | return Machine (Typ, B, Round_Even, N); | |
5121 | end Round_Machine; | |
5122 | ||
5123 | -- Start of processing for Determine_Range_R | |
5124 | ||
5125 | begin | |
5126 | -- Prevent junk warnings by initializing range variables | |
5127 | ||
5128 | Lo := No_Ureal; | |
5129 | Hi := No_Ureal; | |
5130 | Lor := No_Ureal; | |
5131 | Hir := No_Ureal; | |
5132 | ||
5133 | -- For temporary constants internally generated to remove side effects | |
5134 | -- we must use the corresponding expression to determine the range of | |
5135 | -- the expression. But note that the expander can also generate | |
5136 | -- constants in other cases, including deferred constants. | |
5137 | ||
5138 | if Is_Entity_Name (N) | |
5139 | and then Nkind (Parent (Entity (N))) = N_Object_Declaration | |
5140 | and then Ekind (Entity (N)) = E_Constant | |
5141 | and then Is_Internal_Name (Chars (Entity (N))) | |
5142 | then | |
5143 | if Present (Expression (Parent (Entity (N)))) then | |
5144 | Determine_Range_R | |
5145 | (Expression (Parent (Entity (N))), OK, Lo, Hi, Assume_Valid); | |
5146 | ||
5147 | elsif Present (Full_View (Entity (N))) then | |
5148 | Determine_Range_R | |
5149 | (Expression (Parent (Full_View (Entity (N)))), | |
5150 | OK, Lo, Hi, Assume_Valid); | |
5151 | ||
5152 | else | |
5153 | OK := False; | |
5154 | end if; | |
d6e8719d | 5155 | |
6b6bce61 AC |
5156 | return; |
5157 | end if; | |
5158 | ||
5159 | -- If type is not defined, we can't determine its range | |
5160 | ||
5161 | if No (Typ) | |
5162 | ||
5163 | -- We don't deal with anything except IEEE floating-point types | |
5164 | ||
5165 | or else not Is_Floating_Point_Type (Typ) | |
5166 | or else Float_Rep (Typ) /= IEEE_Binary | |
5167 | ||
5168 | -- Ignore type for which an error has been posted, since range in | |
5169 | -- this case may well be a bogosity deriving from the error. Also | |
5170 | -- ignore if error posted on the reference node. | |
5171 | ||
5172 | or else Error_Posted (N) or else Error_Posted (Typ) | |
5173 | then | |
5174 | OK := False; | |
5175 | return; | |
5176 | end if; | |
5177 | ||
5178 | -- For all other cases, we can determine the range | |
5179 | ||
5180 | OK := True; | |
5181 | ||
5182 | -- If value is compile time known, then the possible range is the one | |
5183 | -- value that we know this expression definitely has. | |
5184 | ||
5185 | if Compile_Time_Known_Value (N) then | |
5186 | Lo := Expr_Value_R (N); | |
5187 | Hi := Lo; | |
5188 | return; | |
5189 | end if; | |
5190 | ||
5191 | -- Return if already in the cache | |
5192 | ||
5193 | Cindex := Cache_Index (N mod Cache_Size); | |
5194 | ||
5195 | if Determine_Range_Cache_N (Cindex) = N | |
5196 | and then | |
5197 | Determine_Range_Cache_V (Cindex) = Assume_Valid | |
5198 | then | |
5199 | Lo := Determine_Range_Cache_Lo_R (Cindex); | |
5200 | Hi := Determine_Range_Cache_Hi_R (Cindex); | |
5201 | return; | |
5202 | end if; | |
5203 | ||
5204 | -- Otherwise, start by finding the bounds of the type of the expression, | |
5205 | -- the value cannot be outside this range (if it is, then we have an | |
5206 | -- overflow situation, which is a separate check, we are talking here | |
5207 | -- only about the expression value). | |
5208 | ||
5209 | -- First a check, never try to find the bounds of a generic type, since | |
5210 | -- these bounds are always junk values, and it is only valid to look at | |
5211 | -- the bounds in an instance. | |
5212 | ||
5213 | if Is_Generic_Type (Typ) then | |
5214 | OK := False; | |
5215 | return; | |
5216 | end if; | |
5217 | ||
5218 | -- First step, change to use base type unless we know the value is valid | |
5219 | ||
5220 | if (Is_Entity_Name (N) and then Is_Known_Valid (Entity (N))) | |
5221 | or else Assume_No_Invalid_Values | |
5222 | or else Assume_Valid | |
5223 | then | |
5224 | null; | |
5225 | else | |
5226 | Typ := Underlying_Type (Base_Type (Typ)); | |
5227 | end if; | |
5228 | ||
5229 | -- Retrieve the base type. Handle the case where the base type is a | |
5230 | -- private type. | |
5231 | ||
5232 | Btyp := Base_Type (Typ); | |
5233 | ||
5234 | if Is_Private_Type (Btyp) and then Present (Full_View (Btyp)) then | |
5235 | Btyp := Full_View (Btyp); | |
5236 | end if; | |
5237 | ||
5238 | -- We use the actual bound unless it is dynamic, in which case use the | |
5239 | -- corresponding base type bound if possible. If we can't get a bound | |
5240 | -- then we figure we can't determine the range (a peculiar case, that | |
5241 | -- perhaps cannot happen, but there is no point in bombing in this | |
5242 | -- optimization circuit). | |
5243 | ||
5244 | -- First the low bound | |
5245 | ||
5246 | Bound := Type_Low_Bound (Typ); | |
5247 | ||
5248 | if Compile_Time_Known_Value (Bound) then | |
5249 | Lo := Expr_Value_R (Bound); | |
5250 | ||
5251 | elsif Compile_Time_Known_Value (Type_Low_Bound (Btyp)) then | |
5252 | Lo := Expr_Value_R (Type_Low_Bound (Btyp)); | |
5253 | ||
5254 | else | |
5255 | OK := False; | |
5256 | return; | |
5257 | end if; | |
5258 | ||
5259 | -- Now the high bound | |
5260 | ||
5261 | Bound := Type_High_Bound (Typ); | |
5262 | ||
5263 | -- We need the high bound of the base type later on, and this should | |
5264 | -- always be compile time known. Again, it is not clear that this | |
5265 | -- can ever be false, but no point in bombing. | |
5266 | ||
5267 | if Compile_Time_Known_Value (Type_High_Bound (Btyp)) then | |
5268 | Hbound := Expr_Value_R (Type_High_Bound (Btyp)); | |
5269 | Hi := Hbound; | |
5270 | ||
5271 | else | |
5272 | OK := False; | |
5273 | return; | |
5274 | end if; | |
5275 | ||
5276 | -- If we have a static subtype, then that may have a tighter bound so | |
5277 | -- use the upper bound of the subtype instead in this case. | |
5278 | ||
5279 | if Compile_Time_Known_Value (Bound) then | |
5280 | Hi := Expr_Value_R (Bound); | |
5281 | end if; | |
5282 | ||
5283 | -- We may be able to refine this value in certain situations. If any | |
5284 | -- refinement is possible, then Lor and Hir are set to possibly tighter | |
5285 | -- bounds, and OK1 is set to True. | |
5286 | ||
5287 | case Nkind (N) is | |
5288 | ||
5289 | -- For unary plus, result is limited by range of operand | |
5290 | ||
5291 | when N_Op_Plus => | |
5292 | Determine_Range_R | |
5293 | (Right_Opnd (N), OK1, Lor, Hir, Assume_Valid); | |
5294 | ||
5295 | -- For unary minus, determine range of operand, and negate it | |
5296 | ||
5297 | when N_Op_Minus => | |
5298 | Determine_Range_R | |
5299 | (Right_Opnd (N), OK1, Lo_Right, Hi_Right, Assume_Valid); | |
5300 | ||
5301 | if OK1 then | |
5302 | Lor := -Hi_Right; | |
5303 | Hir := -Lo_Right; | |
5304 | end if; | |
5305 | ||
5306 | -- For binary addition, get range of each operand and do the | |
5307 | -- addition to get the result range. | |
5308 | ||
5309 | when N_Op_Add => | |
5310 | if OK_Operands then | |
5311 | Lor := Round_Machine (Lo_Left + Lo_Right); | |
5312 | Hir := Round_Machine (Hi_Left + Hi_Right); | |
5313 | end if; | |
5314 | ||
5315 | -- For binary subtraction, get range of each operand and do the worst | |
5316 | -- case subtraction to get the result range. | |
5317 | ||
5318 | when N_Op_Subtract => | |
5319 | if OK_Operands then | |
5320 | Lor := Round_Machine (Lo_Left - Hi_Right); | |
5321 | Hir := Round_Machine (Hi_Left - Lo_Right); | |
5322 | end if; | |
5323 | ||
5324 | -- For multiplication, get range of each operand and do the | |
5325 | -- four multiplications to get the result range. | |
5326 | ||
5327 | when N_Op_Multiply => | |
5328 | if OK_Operands then | |
5329 | declare | |
5330 | M1 : constant Ureal := Round_Machine (Lo_Left * Lo_Right); | |
5331 | M2 : constant Ureal := Round_Machine (Lo_Left * Hi_Right); | |
5332 | M3 : constant Ureal := Round_Machine (Hi_Left * Lo_Right); | |
5333 | M4 : constant Ureal := Round_Machine (Hi_Left * Hi_Right); | |
94295b25 | 5334 | |
6b6bce61 AC |
5335 | begin |
5336 | Lor := UR_Min (UR_Min (M1, M2), UR_Min (M3, M4)); | |
5337 | Hir := UR_Max (UR_Max (M1, M2), UR_Max (M3, M4)); | |
5338 | end; | |
5339 | end if; | |
5340 | ||
5341 | -- For division, consider separately the cases where the right | |
5342 | -- operand is positive or negative. Otherwise, the right operand | |
5343 | -- can be arbitrarily close to zero, so the result is likely to | |
5344 | -- be unbounded in one direction, do not attempt to compute it. | |
5345 | ||
5346 | when N_Op_Divide => | |
5347 | if OK_Operands then | |
5348 | ||
5349 | -- Right operand is positive | |
5350 | ||
5351 | if Lo_Right > Ureal_0 then | |
5352 | ||
5353 | -- If the low bound of the left operand is negative, obtain | |
5354 | -- the overall low bound by dividing it by the smallest | |
5355 | -- value of the right operand, and otherwise by the largest | |
5356 | -- value of the right operand. | |
5357 | ||
5358 | if Lo_Left < Ureal_0 then | |
5359 | Lor := Round_Machine (Lo_Left / Lo_Right); | |
5360 | else | |
5361 | Lor := Round_Machine (Lo_Left / Hi_Right); | |
5362 | end if; | |
5363 | ||
5364 | -- If the high bound of the left operand is negative, obtain | |
5365 | -- the overall high bound by dividing it by the largest | |
5366 | -- value of the right operand, and otherwise by the | |
5367 | -- smallest value of the right operand. | |
5368 | ||
5369 | if Hi_Left < Ureal_0 then | |
5370 | Hir := Round_Machine (Hi_Left / Hi_Right); | |
5371 | else | |
5372 | Hir := Round_Machine (Hi_Left / Lo_Right); | |
5373 | end if; | |
5374 | ||
5375 | -- Right operand is negative | |
5376 | ||
5377 | elsif Hi_Right < Ureal_0 then | |
5378 | ||
5379 | -- If the low bound of the left operand is negative, obtain | |
5380 | -- the overall low bound by dividing it by the largest | |
5381 | -- value of the right operand, and otherwise by the smallest | |
5382 | -- value of the right operand. | |
5383 | ||
5384 | if Lo_Left < Ureal_0 then | |
5385 | Lor := Round_Machine (Lo_Left / Hi_Right); | |
5386 | else | |
5387 | Lor := Round_Machine (Lo_Left / Lo_Right); | |
5388 | end if; | |
5389 | ||
5390 | -- If the high bound of the left operand is negative, obtain | |
5391 | -- the overall high bound by dividing it by the smallest | |
5392 | -- value of the right operand, and otherwise by the | |
5393 | -- largest value of the right operand. | |
5394 | ||
5395 | if Hi_Left < Ureal_0 then | |
5396 | Hir := Round_Machine (Hi_Left / Lo_Right); | |
5397 | else | |
5398 | Hir := Round_Machine (Hi_Left / Hi_Right); | |
5399 | end if; | |
5400 | ||
5401 | else | |
5402 | OK1 := False; | |
5403 | end if; | |
5404 | end if; | |
5405 | ||
6b6bce61 | 5406 | when N_Type_Conversion => |
3c77943e YM |
5407 | |
5408 | -- For type conversion from one floating-point type to another, we | |
5409 | -- can refine the range using the converted value. | |
5410 | ||
5411 | if Is_Floating_Point_Type (Etype (Expression (N))) then | |
5412 | Determine_Range_R (Expression (N), OK1, Lor, Hir, Assume_Valid); | |
5413 | ||
5414 | -- When converting an integer to a floating-point type, determine | |
5415 | -- the range in integer first, and then convert the bounds. | |
5416 | ||
5417 | elsif Is_Discrete_Type (Etype (Expression (N))) then | |
5418 | declare | |
94295b25 AC |
5419 | Hir_Int : Uint; |
5420 | Lor_Int : Uint; | |
5421 | ||
3c77943e | 5422 | begin |
94295b25 AC |
5423 | Determine_Range |
5424 | (Expression (N), OK1, Lor_Int, Hir_Int, Assume_Valid); | |
3c77943e YM |
5425 | |
5426 | if OK1 then | |
5427 | Lor := Round_Machine (UR_From_Uint (Lor_Int)); | |
5428 | Hir := Round_Machine (UR_From_Uint (Hir_Int)); | |
5429 | end if; | |
5430 | end; | |
5431 | ||
5432 | else | |
5433 | OK1 := False; | |
5434 | end if; | |
6b6bce61 AC |
5435 | |
5436 | -- Nothing special to do for all other expression kinds | |
5437 | ||
5438 | when others => | |
5439 | OK1 := False; | |
5440 | Lor := No_Ureal; | |
5441 | Hir := No_Ureal; | |
5442 | end case; | |
5443 | ||
5444 | -- At this stage, if OK1 is true, then we know that the actual result of | |
5445 | -- the computed expression is in the range Lor .. Hir. We can use this | |
5446 | -- to restrict the possible range of results. | |
5447 | ||
5448 | if OK1 then | |
5449 | ||
5450 | -- If the refined value of the low bound is greater than the type | |
5451 | -- low bound, then reset it to the more restrictive value. | |
5452 | ||
5453 | if Lor > Lo then | |
5454 | Lo := Lor; | |
5455 | end if; | |
5456 | ||
5457 | -- Similarly, if the refined value of the high bound is less than the | |
5458 | -- value so far, then reset it to the more restrictive value. | |
5459 | ||
5460 | if Hir < Hi then | |
5461 | Hi := Hir; | |
5462 | end if; | |
5463 | end if; | |
5464 | ||
5465 | -- Set cache entry for future call and we are all done | |
5466 | ||
5467 | Determine_Range_Cache_N (Cindex) := N; | |
5468 | Determine_Range_Cache_V (Cindex) := Assume_Valid; | |
5469 | Determine_Range_Cache_Lo_R (Cindex) := Lo; | |
5470 | Determine_Range_Cache_Hi_R (Cindex) := Hi; | |
5471 | return; | |
5472 | ||
5473 | -- If any exception occurs, it means that we have some bug in the compiler, | |
5474 | -- possibly triggered by a previous error, or by some unforeseen peculiar | |
5475 | -- occurrence. However, this is only an optimization attempt, so there is | |
5476 | -- really no point in crashing the compiler. Instead we just decide, too | |
5477 | -- bad, we can't figure out a range in this case after all. | |
5478 | ||
5479 | exception | |
5480 | when others => | |
5481 | ||
5482 | -- Debug flag K disables this behavior (useful for debugging) | |
5483 | ||
5484 | if Debug_Flag_K then | |
5485 | raise; | |
5486 | else | |
5487 | OK := False; | |
5488 | Lo := No_Ureal; | |
5489 | Hi := No_Ureal; | |
5490 | return; | |
5491 | end if; | |
5492 | end Determine_Range_R; | |
5493 | ||
70482933 RK |
5494 | ------------------------------------ |
5495 | -- Discriminant_Checks_Suppressed -- | |
5496 | ------------------------------------ | |
5497 | ||
5498 | function Discriminant_Checks_Suppressed (E : Entity_Id) return Boolean is | |
5499 | begin | |
fbf5a39b AC |
5500 | if Present (E) then |
5501 | if Is_Unchecked_Union (E) then | |
5502 | return True; | |
5503 | elsif Checks_May_Be_Suppressed (E) then | |
5504 | return Is_Check_Suppressed (E, Discriminant_Check); | |
5505 | end if; | |
5506 | end if; | |
5507 | ||
3217f71e | 5508 | return Scope_Suppress.Suppress (Discriminant_Check); |
70482933 RK |
5509 | end Discriminant_Checks_Suppressed; |
5510 | ||
5511 | -------------------------------- | |
5512 | -- Division_Checks_Suppressed -- | |
5513 | -------------------------------- | |
5514 | ||
5515 | function Division_Checks_Suppressed (E : Entity_Id) return Boolean is | |
5516 | begin | |
fbf5a39b AC |
5517 | if Present (E) and then Checks_May_Be_Suppressed (E) then |
5518 | return Is_Check_Suppressed (E, Division_Check); | |
5519 | else | |
3217f71e | 5520 | return Scope_Suppress.Suppress (Division_Check); |
fbf5a39b | 5521 | end if; |
70482933 RK |
5522 | end Division_Checks_Suppressed; |
5523 | ||
59f4d038 RD |
5524 | -------------------------------------- |
5525 | -- Duplicated_Tag_Checks_Suppressed -- | |
5526 | -------------------------------------- | |
5527 | ||
5528 | function Duplicated_Tag_Checks_Suppressed (E : Entity_Id) return Boolean is | |
5529 | begin | |
5530 | if Present (E) and then Checks_May_Be_Suppressed (E) then | |
5531 | return Is_Check_Suppressed (E, Duplicated_Tag_Check); | |
5532 | else | |
5533 | return Scope_Suppress.Suppress (Duplicated_Tag_Check); | |
5534 | end if; | |
5535 | end Duplicated_Tag_Checks_Suppressed; | |
5536 | ||
70482933 RK |
5537 | ----------------------------------- |
5538 | -- Elaboration_Checks_Suppressed -- | |
5539 | ----------------------------------- | |
5540 | ||
5541 | function Elaboration_Checks_Suppressed (E : Entity_Id) return Boolean is | |
5542 | begin | |
f02b8bb8 RD |
5543 | -- The complication in this routine is that if we are in the dynamic |
5544 | -- model of elaboration, we also check All_Checks, since All_Checks | |
5545 | -- does not set Elaboration_Check explicitly. | |
5546 | ||
fbf5a39b AC |
5547 | if Present (E) then |
5548 | if Kill_Elaboration_Checks (E) then | |
5549 | return True; | |
f02b8bb8 | 5550 | |
fbf5a39b | 5551 | elsif Checks_May_Be_Suppressed (E) then |
f02b8bb8 RD |
5552 | if Is_Check_Suppressed (E, Elaboration_Check) then |
5553 | return True; | |
90e491a7 | 5554 | |
f02b8bb8 RD |
5555 | elsif Dynamic_Elaboration_Checks then |
5556 | return Is_Check_Suppressed (E, All_Checks); | |
90e491a7 | 5557 | |
f02b8bb8 RD |
5558 | else |
5559 | return False; | |
5560 | end if; | |
fbf5a39b AC |
5561 | end if; |
5562 | end if; | |
5563 | ||
3217f71e | 5564 | if Scope_Suppress.Suppress (Elaboration_Check) then |
f02b8bb8 | 5565 | return True; |
90e491a7 | 5566 | |
f02b8bb8 | 5567 | elsif Dynamic_Elaboration_Checks then |
3217f71e | 5568 | return Scope_Suppress.Suppress (All_Checks); |
90e491a7 | 5569 | |
f02b8bb8 RD |
5570 | else |
5571 | return False; | |
5572 | end if; | |
70482933 RK |
5573 | end Elaboration_Checks_Suppressed; |
5574 | ||
fbf5a39b AC |
5575 | --------------------------- |
5576 | -- Enable_Overflow_Check -- | |
5577 | --------------------------- | |
5578 | ||
5579 | procedure Enable_Overflow_Check (N : Node_Id) is | |
d6e8719d | 5580 | Typ : constant Entity_Id := Base_Type (Etype (N)); |
15c94a55 | 5581 | Mode : constant Overflow_Mode_Type := Overflow_Check_Mode; |
acad3c0a AC |
5582 | Chk : Nat; |
5583 | OK : Boolean; | |
5584 | Ent : Entity_Id; | |
5585 | Ofs : Uint; | |
5586 | Lo : Uint; | |
5587 | Hi : Uint; | |
70482933 | 5588 | |
b7c874a7 AC |
5589 | Do_Ovflow_Check : Boolean; |
5590 | ||
70482933 | 5591 | begin |
fbf5a39b AC |
5592 | if Debug_Flag_CC then |
5593 | w ("Enable_Overflow_Check for node ", Int (N)); | |
5594 | Write_Str (" Source location = "); | |
5595 | wl (Sloc (N)); | |
11b4899f | 5596 | pg (Union_Id (N)); |
70482933 | 5597 | end if; |
70482933 | 5598 | |
3d5952be AC |
5599 | -- No check if overflow checks suppressed for type of node |
5600 | ||
a7f1b24f | 5601 | if Overflow_Checks_Suppressed (Etype (N)) then |
3d5952be AC |
5602 | return; |
5603 | ||
991395ab AC |
5604 | -- Nothing to do for unsigned integer types, which do not overflow |
5605 | ||
5606 | elsif Is_Modular_Integer_Type (Typ) then | |
5607 | return; | |
acad3c0a AC |
5608 | end if; |
5609 | ||
a7f1b24f | 5610 | -- This is the point at which processing for STRICT mode diverges |
5707e389 AC |
5611 | -- from processing for MINIMIZED/ELIMINATED modes. This divergence is |
5612 | -- probably more extreme that it needs to be, but what is going on here | |
5613 | -- is that when we introduced MINIMIZED/ELIMINATED modes, we wanted | |
a7f1b24f | 5614 | -- to leave the processing for STRICT mode untouched. There were |
5707e389 | 5615 | -- two reasons for this. First it avoided any incompatible change of |
a7f1b24f | 5616 | -- behavior. Second, it guaranteed that STRICT mode continued to be |
5707e389 | 5617 | -- legacy reliable. |
acad3c0a | 5618 | |
a7f1b24f | 5619 | -- The big difference is that in STRICT mode there is a fair amount of |
acad3c0a AC |
5620 | -- circuitry to try to avoid setting the Do_Overflow_Check flag if we |
5621 | -- know that no check is needed. We skip all that in the two new modes, | |
5622 | -- since really overflow checking happens over a whole subtree, and we | |
5623 | -- do the corresponding optimizations later on when applying the checks. | |
5624 | ||
5625 | if Mode in Minimized_Or_Eliminated then | |
a7f1b24f RD |
5626 | if not (Overflow_Checks_Suppressed (Etype (N))) |
5627 | and then not (Is_Entity_Name (N) | |
5628 | and then Overflow_Checks_Suppressed (Entity (N))) | |
5629 | then | |
5630 | Activate_Overflow_Check (N); | |
5631 | end if; | |
acad3c0a AC |
5632 | |
5633 | if Debug_Flag_CC then | |
5634 | w ("Minimized/Eliminated mode"); | |
5635 | end if; | |
5636 | ||
5637 | return; | |
5638 | end if; | |
5639 | ||
a7f1b24f | 5640 | -- Remainder of processing is for STRICT case, and is unchanged from |
3ada950b | 5641 | -- earlier versions preceding the addition of MINIMIZED/ELIMINATED. |
991395ab | 5642 | |
675d6070 TQ |
5643 | -- Nothing to do if the range of the result is known OK. We skip this |
5644 | -- for conversions, since the caller already did the check, and in any | |
5645 | -- case the condition for deleting the check for a type conversion is | |
f2cbd970 | 5646 | -- different. |
70482933 | 5647 | |
acad3c0a | 5648 | if Nkind (N) /= N_Type_Conversion then |
c800f862 | 5649 | Determine_Range (N, OK, Lo, Hi, Assume_Valid => True); |
70482933 | 5650 | |
f2cbd970 JM |
5651 | -- Note in the test below that we assume that the range is not OK |
5652 | -- if a bound of the range is equal to that of the type. That's not | |
5653 | -- quite accurate but we do this for the following reasons: | |
70482933 | 5654 | |
fbf5a39b AC |
5655 | -- a) The way that Determine_Range works, it will typically report |
5656 | -- the bounds of the value as being equal to the bounds of the | |
5657 | -- type, because it either can't tell anything more precise, or | |
5658 | -- does not think it is worth the effort to be more precise. | |
70482933 | 5659 | |
fbf5a39b AC |
5660 | -- b) It is very unusual to have a situation in which this would |
5661 | -- generate an unnecessary overflow check (an example would be | |
5662 | -- a subtype with a range 0 .. Integer'Last - 1 to which the | |
f2cbd970 | 5663 | -- literal value one is added). |
70482933 | 5664 | |
fbf5a39b AC |
5665 | -- c) The alternative is a lot of special casing in this routine |
5666 | -- which would partially duplicate Determine_Range processing. | |
70482933 | 5667 | |
b7c874a7 AC |
5668 | if OK then |
5669 | Do_Ovflow_Check := True; | |
5670 | ||
5671 | -- Note that the following checks are quite deliberately > and < | |
5672 | -- rather than >= and <= as explained above. | |
5673 | ||
5674 | if Lo > Expr_Value (Type_Low_Bound (Typ)) | |
5675 | and then | |
5676 | Hi < Expr_Value (Type_High_Bound (Typ)) | |
5677 | then | |
5678 | Do_Ovflow_Check := False; | |
5679 | ||
5680 | -- Despite the comments above, it is worth dealing specially with | |
5681 | -- division specially. The only case where integer division can | |
5682 | -- overflow is (largest negative number) / (-1). So we will do | |
5683 | -- an extra range analysis to see if this is possible. | |
5684 | ||
5685 | elsif Nkind (N) = N_Op_Divide then | |
5686 | Determine_Range | |
5687 | (Left_Opnd (N), OK, Lo, Hi, Assume_Valid => True); | |
5688 | ||
5689 | if OK and then Lo > Expr_Value (Type_Low_Bound (Typ)) then | |
5690 | Do_Ovflow_Check := False; | |
5691 | ||
5692 | else | |
5693 | Determine_Range | |
5694 | (Right_Opnd (N), OK, Lo, Hi, Assume_Valid => True); | |
5695 | ||
5696 | if OK and then (Lo > Uint_Minus_1 | |
5697 | or else | |
5698 | Hi < Uint_Minus_1) | |
5699 | then | |
5700 | Do_Ovflow_Check := False; | |
5701 | end if; | |
5702 | end if; | |
fbf5a39b AC |
5703 | end if; |
5704 | ||
b7c874a7 AC |
5705 | -- If no overflow check required, we are done |
5706 | ||
5707 | if not Do_Ovflow_Check then | |
5708 | if Debug_Flag_CC then | |
5709 | w ("No overflow check required"); | |
5710 | end if; | |
5711 | ||
5712 | return; | |
5713 | end if; | |
fbf5a39b AC |
5714 | end if; |
5715 | end if; | |
5716 | ||
675d6070 TQ |
5717 | -- If not in optimizing mode, set flag and we are done. We are also done |
5718 | -- (and just set the flag) if the type is not a discrete type, since it | |
5719 | -- is not worth the effort to eliminate checks for other than discrete | |
5720 | -- types. In addition, we take this same path if we have stored the | |
5721 | -- maximum number of checks possible already (a very unlikely situation, | |
a90bd866 | 5722 | -- but we do not want to blow up). |
fbf5a39b AC |
5723 | |
5724 | if Optimization_Level = 0 | |
5725 | or else not Is_Discrete_Type (Etype (N)) | |
5726 | or else Num_Saved_Checks = Saved_Checks'Last | |
70482933 | 5727 | then |
11b4899f | 5728 | Activate_Overflow_Check (N); |
fbf5a39b AC |
5729 | |
5730 | if Debug_Flag_CC then | |
5731 | w ("Optimization off"); | |
5732 | end if; | |
5733 | ||
70482933 | 5734 | return; |
fbf5a39b | 5735 | end if; |
70482933 | 5736 | |
fbf5a39b AC |
5737 | -- Otherwise evaluate and check the expression |
5738 | ||
5739 | Find_Check | |
5740 | (Expr => N, | |
5741 | Check_Type => 'O', | |
5742 | Target_Type => Empty, | |
5743 | Entry_OK => OK, | |
5744 | Check_Num => Chk, | |
5745 | Ent => Ent, | |
5746 | Ofs => Ofs); | |
5747 | ||
5748 | if Debug_Flag_CC then | |
5749 | w ("Called Find_Check"); | |
5750 | w (" OK = ", OK); | |
5751 | ||
5752 | if OK then | |
5753 | w (" Check_Num = ", Chk); | |
5754 | w (" Ent = ", Int (Ent)); | |
5755 | Write_Str (" Ofs = "); | |
5756 | pid (Ofs); | |
5757 | end if; | |
5758 | end if; | |
70482933 | 5759 | |
fbf5a39b AC |
5760 | -- If check is not of form to optimize, then set flag and we are done |
5761 | ||
5762 | if not OK then | |
11b4899f | 5763 | Activate_Overflow_Check (N); |
70482933 | 5764 | return; |
fbf5a39b | 5765 | end if; |
70482933 | 5766 | |
fbf5a39b AC |
5767 | -- If check is already performed, then return without setting flag |
5768 | ||
5769 | if Chk /= 0 then | |
5770 | if Debug_Flag_CC then | |
5771 | w ("Check suppressed!"); | |
5772 | end if; | |
70482933 | 5773 | |
70482933 | 5774 | return; |
fbf5a39b | 5775 | end if; |
70482933 | 5776 | |
fbf5a39b AC |
5777 | -- Here we will make a new entry for the new check |
5778 | ||
11b4899f | 5779 | Activate_Overflow_Check (N); |
fbf5a39b AC |
5780 | Num_Saved_Checks := Num_Saved_Checks + 1; |
5781 | Saved_Checks (Num_Saved_Checks) := | |
5782 | (Killed => False, | |
5783 | Entity => Ent, | |
5784 | Offset => Ofs, | |
5785 | Check_Type => 'O', | |
5786 | Target_Type => Empty); | |
5787 | ||
5788 | if Debug_Flag_CC then | |
5789 | w ("Make new entry, check number = ", Num_Saved_Checks); | |
5790 | w (" Entity = ", Int (Ent)); | |
5791 | Write_Str (" Offset = "); | |
5792 | pid (Ofs); | |
5793 | w (" Check_Type = O"); | |
5794 | w (" Target_Type = Empty"); | |
5795 | end if; | |
70482933 | 5796 | |
675d6070 | 5797 | -- If we get an exception, then something went wrong, probably because of |
637a41a5 AC |
5798 | -- an error in the structure of the tree due to an incorrect program. Or |
5799 | -- it may be a bug in the optimization circuit. In either case the safest | |
675d6070 | 5800 | -- thing is simply to set the check flag unconditionally. |
fbf5a39b AC |
5801 | |
5802 | exception | |
5803 | when others => | |
11b4899f | 5804 | Activate_Overflow_Check (N); |
fbf5a39b AC |
5805 | |
5806 | if Debug_Flag_CC then | |
5807 | w (" exception occurred, overflow flag set"); | |
5808 | end if; | |
5809 | ||
5810 | return; | |
5811 | end Enable_Overflow_Check; | |
5812 | ||
5813 | ------------------------ | |
5814 | -- Enable_Range_Check -- | |
5815 | ------------------------ | |
5816 | ||
5817 | procedure Enable_Range_Check (N : Node_Id) is | |
5818 | Chk : Nat; | |
5819 | OK : Boolean; | |
5820 | Ent : Entity_Id; | |
5821 | Ofs : Uint; | |
5822 | Ttyp : Entity_Id; | |
5823 | P : Node_Id; | |
5824 | ||
5825 | begin | |
675d6070 | 5826 | -- Return if unchecked type conversion with range check killed. In this |
a90bd866 | 5827 | -- case we never set the flag (that's what Kill_Range_Check is about). |
fbf5a39b AC |
5828 | |
5829 | if Nkind (N) = N_Unchecked_Type_Conversion | |
5830 | and then Kill_Range_Check (N) | |
70482933 RK |
5831 | then |
5832 | return; | |
fbf5a39b | 5833 | end if; |
70482933 | 5834 | |
c7532b2d AC |
5835 | -- Do not set range check flag if parent is assignment statement or |
5836 | -- object declaration with Suppress_Assignment_Checks flag set | |
5837 | ||
5838 | if Nkind_In (Parent (N), N_Assignment_Statement, N_Object_Declaration) | |
5839 | and then Suppress_Assignment_Checks (Parent (N)) | |
5840 | then | |
5841 | return; | |
5842 | end if; | |
5843 | ||
c064e066 RD |
5844 | -- Check for various cases where we should suppress the range check |
5845 | ||
5846 | -- No check if range checks suppressed for type of node | |
5847 | ||
637a41a5 | 5848 | if Present (Etype (N)) and then Range_Checks_Suppressed (Etype (N)) then |
c064e066 RD |
5849 | return; |
5850 | ||
5851 | -- No check if node is an entity name, and range checks are suppressed | |
5852 | -- for this entity, or for the type of this entity. | |
5853 | ||
5854 | elsif Is_Entity_Name (N) | |
5855 | and then (Range_Checks_Suppressed (Entity (N)) | |
637a41a5 | 5856 | or else Range_Checks_Suppressed (Etype (Entity (N)))) |
c064e066 RD |
5857 | then |
5858 | return; | |
5859 | ||
5860 | -- No checks if index of array, and index checks are suppressed for | |
5861 | -- the array object or the type of the array. | |
5862 | ||
5863 | elsif Nkind (Parent (N)) = N_Indexed_Component then | |
5864 | declare | |
5865 | Pref : constant Node_Id := Prefix (Parent (N)); | |
5866 | begin | |
5867 | if Is_Entity_Name (Pref) | |
5868 | and then Index_Checks_Suppressed (Entity (Pref)) | |
5869 | then | |
5870 | return; | |
5871 | elsif Index_Checks_Suppressed (Etype (Pref)) then | |
5872 | return; | |
5873 | end if; | |
5874 | end; | |
5875 | end if; | |
5876 | ||
fbf5a39b | 5877 | -- Debug trace output |
70482933 | 5878 | |
fbf5a39b AC |
5879 | if Debug_Flag_CC then |
5880 | w ("Enable_Range_Check for node ", Int (N)); | |
5881 | Write_Str (" Source location = "); | |
5882 | wl (Sloc (N)); | |
11b4899f | 5883 | pg (Union_Id (N)); |
fbf5a39b AC |
5884 | end if; |
5885 | ||
675d6070 TQ |
5886 | -- If not in optimizing mode, set flag and we are done. We are also done |
5887 | -- (and just set the flag) if the type is not a discrete type, since it | |
5888 | -- is not worth the effort to eliminate checks for other than discrete | |
5889 | -- types. In addition, we take this same path if we have stored the | |
5890 | -- maximum number of checks possible already (a very unlikely situation, | |
a90bd866 | 5891 | -- but we do not want to blow up). |
fbf5a39b AC |
5892 | |
5893 | if Optimization_Level = 0 | |
5894 | or else No (Etype (N)) | |
5895 | or else not Is_Discrete_Type (Etype (N)) | |
5896 | or else Num_Saved_Checks = Saved_Checks'Last | |
70482933 | 5897 | then |
11b4899f | 5898 | Activate_Range_Check (N); |
fbf5a39b AC |
5899 | |
5900 | if Debug_Flag_CC then | |
5901 | w ("Optimization off"); | |
5902 | end if; | |
5903 | ||
70482933 | 5904 | return; |
fbf5a39b | 5905 | end if; |
70482933 | 5906 | |
fbf5a39b | 5907 | -- Otherwise find out the target type |
70482933 | 5908 | |
fbf5a39b | 5909 | P := Parent (N); |
70482933 | 5910 | |
fbf5a39b AC |
5911 | -- For assignment, use left side subtype |
5912 | ||
5913 | if Nkind (P) = N_Assignment_Statement | |
5914 | and then Expression (P) = N | |
5915 | then | |
5916 | Ttyp := Etype (Name (P)); | |
5917 | ||
5918 | -- For indexed component, use subscript subtype | |
5919 | ||
5920 | elsif Nkind (P) = N_Indexed_Component then | |
5921 | declare | |
5922 | Atyp : Entity_Id; | |
5923 | Indx : Node_Id; | |
5924 | Subs : Node_Id; | |
5925 | ||
5926 | begin | |
5927 | Atyp := Etype (Prefix (P)); | |
5928 | ||
5929 | if Is_Access_Type (Atyp) then | |
5930 | Atyp := Designated_Type (Atyp); | |
d935a36e AC |
5931 | |
5932 | -- If the prefix is an access to an unconstrained array, | |
675d6070 TQ |
5933 | -- perform check unconditionally: it depends on the bounds of |
5934 | -- an object and we cannot currently recognize whether the test | |
5935 | -- may be redundant. | |
d935a36e AC |
5936 | |
5937 | if not Is_Constrained (Atyp) then | |
11b4899f | 5938 | Activate_Range_Check (N); |
d935a36e AC |
5939 | return; |
5940 | end if; | |
82c80734 | 5941 | |
ef2c20e7 AC |
5942 | -- Ditto if prefix is simply an unconstrained array. We used |
5943 | -- to think this case was OK, if the prefix was not an explicit | |
5944 | -- dereference, but we have now seen a case where this is not | |
5945 | -- true, so it is safer to just suppress the optimization in this | |
5946 | -- case. The back end is getting better at eliminating redundant | |
5947 | -- checks in any case, so the loss won't be important. | |
82c80734 | 5948 | |
ef2c20e7 | 5949 | elsif Is_Array_Type (Atyp) |
82c80734 RD |
5950 | and then not Is_Constrained (Atyp) |
5951 | then | |
11b4899f | 5952 | Activate_Range_Check (N); |
82c80734 | 5953 | return; |
fbf5a39b AC |
5954 | end if; |
5955 | ||
5956 | Indx := First_Index (Atyp); | |
5957 | Subs := First (Expressions (P)); | |
5958 | loop | |
5959 | if Subs = N then | |
5960 | Ttyp := Etype (Indx); | |
5961 | exit; | |
5962 | end if; | |
5963 | ||
5964 | Next_Index (Indx); | |
5965 | Next (Subs); | |
5966 | end loop; | |
5967 | end; | |
5968 | ||
5969 | -- For now, ignore all other cases, they are not so interesting | |
5970 | ||
5971 | else | |
5972 | if Debug_Flag_CC then | |
5973 | w (" target type not found, flag set"); | |
5974 | end if; | |
5975 | ||
11b4899f | 5976 | Activate_Range_Check (N); |
fbf5a39b AC |
5977 | return; |
5978 | end if; | |
5979 | ||
5980 | -- Evaluate and check the expression | |
5981 | ||
5982 | Find_Check | |
5983 | (Expr => N, | |
5984 | Check_Type => 'R', | |
5985 | Target_Type => Ttyp, | |
5986 | Entry_OK => OK, | |
5987 | Check_Num => Chk, | |
5988 | Ent => Ent, | |
5989 | Ofs => Ofs); | |
5990 | ||
5991 | if Debug_Flag_CC then | |
5992 | w ("Called Find_Check"); | |
5993 | w ("Target_Typ = ", Int (Ttyp)); | |
5994 | w (" OK = ", OK); | |
5995 | ||
5996 | if OK then | |
5997 | w (" Check_Num = ", Chk); | |
5998 | w (" Ent = ", Int (Ent)); | |
5999 | Write_Str (" Ofs = "); | |
6000 | pid (Ofs); | |
6001 | end if; | |
6002 | end if; | |
6003 | ||
6004 | -- If check is not of form to optimize, then set flag and we are done | |
6005 | ||
6006 | if not OK then | |
6007 | if Debug_Flag_CC then | |
6008 | w (" expression not of optimizable type, flag set"); | |
6009 | end if; | |
6010 | ||
11b4899f | 6011 | Activate_Range_Check (N); |
fbf5a39b AC |
6012 | return; |
6013 | end if; | |
6014 | ||
6015 | -- If check is already performed, then return without setting flag | |
6016 | ||
6017 | if Chk /= 0 then | |
6018 | if Debug_Flag_CC then | |
6019 | w ("Check suppressed!"); | |
6020 | end if; | |
6021 | ||
6022 | return; | |
6023 | end if; | |
6024 | ||
6025 | -- Here we will make a new entry for the new check | |
6026 | ||
11b4899f | 6027 | Activate_Range_Check (N); |
fbf5a39b AC |
6028 | Num_Saved_Checks := Num_Saved_Checks + 1; |
6029 | Saved_Checks (Num_Saved_Checks) := | |
6030 | (Killed => False, | |
6031 | Entity => Ent, | |
6032 | Offset => Ofs, | |
6033 | Check_Type => 'R', | |
6034 | Target_Type => Ttyp); | |
6035 | ||
6036 | if Debug_Flag_CC then | |
6037 | w ("Make new entry, check number = ", Num_Saved_Checks); | |
6038 | w (" Entity = ", Int (Ent)); | |
6039 | Write_Str (" Offset = "); | |
6040 | pid (Ofs); | |
6041 | w (" Check_Type = R"); | |
6042 | w (" Target_Type = ", Int (Ttyp)); | |
11b4899f | 6043 | pg (Union_Id (Ttyp)); |
fbf5a39b AC |
6044 | end if; |
6045 | ||
675d6070 TQ |
6046 | -- If we get an exception, then something went wrong, probably because of |
6047 | -- an error in the structure of the tree due to an incorrect program. Or | |
6048 | -- it may be a bug in the optimization circuit. In either case the safest | |
6049 | -- thing is simply to set the check flag unconditionally. | |
fbf5a39b AC |
6050 | |
6051 | exception | |
6052 | when others => | |
11b4899f | 6053 | Activate_Range_Check (N); |
fbf5a39b AC |
6054 | |
6055 | if Debug_Flag_CC then | |
6056 | w (" exception occurred, range flag set"); | |
6057 | end if; | |
6058 | ||
6059 | return; | |
6060 | end Enable_Range_Check; | |
6061 | ||
6062 | ------------------ | |
6063 | -- Ensure_Valid -- | |
6064 | ------------------ | |
6065 | ||
2934b84a AC |
6066 | procedure Ensure_Valid |
6067 | (Expr : Node_Id; | |
6068 | Holes_OK : Boolean := False; | |
6069 | Related_Id : Entity_Id := Empty; | |
6070 | Is_Low_Bound : Boolean := False; | |
6071 | Is_High_Bound : Boolean := False) | |
6072 | is | |
fbf5a39b AC |
6073 | Typ : constant Entity_Id := Etype (Expr); |
6074 | ||
6075 | begin | |
6076 | -- Ignore call if we are not doing any validity checking | |
6077 | ||
6078 | if not Validity_Checks_On then | |
6079 | return; | |
6080 | ||
c064e066 | 6081 | -- Ignore call if range or validity checks suppressed on entity or type |
fbf5a39b | 6082 | |
c064e066 | 6083 | elsif Range_Or_Validity_Checks_Suppressed (Expr) then |
fbf5a39b AC |
6084 | return; |
6085 | ||
675d6070 TQ |
6086 | -- No check required if expression is from the expander, we assume the |
6087 | -- expander will generate whatever checks are needed. Note that this is | |
a90bd866 | 6088 | -- not just an optimization, it avoids infinite recursions. |
fbf5a39b AC |
6089 | |
6090 | -- Unchecked conversions must be checked, unless they are initialized | |
6091 | -- scalar values, as in a component assignment in an init proc. | |
6092 | ||
6093 | -- In addition, we force a check if Force_Validity_Checks is set | |
6094 | ||
6095 | elsif not Comes_From_Source (Expr) | |
2e60feb5 PMR |
6096 | and then not |
6097 | (Nkind (Expr) = N_Identifier | |
6098 | and then Present (Renamed_Object (Entity (Expr))) | |
6099 | and then Comes_From_Source (Renamed_Object (Entity (Expr)))) | |
fbf5a39b AC |
6100 | and then not Force_Validity_Checks |
6101 | and then (Nkind (Expr) /= N_Unchecked_Type_Conversion | |
6102 | or else Kill_Range_Check (Expr)) | |
6103 | then | |
6104 | return; | |
6105 | ||
6106 | -- No check required if expression is known to have valid value | |
6107 | ||
6108 | elsif Expr_Known_Valid (Expr) then | |
6109 | return; | |
6110 | ||
229fa5db AC |
6111 | -- No check needed within a generated predicate function. Validity |
6112 | -- of input value will have been checked earlier. | |
6113 | ||
6114 | elsif Ekind (Current_Scope) = E_Function | |
6115 | and then Is_Predicate_Function (Current_Scope) | |
6116 | then | |
6117 | return; | |
6118 | ||
675d6070 TQ |
6119 | -- Ignore case of enumeration with holes where the flag is set not to |
6120 | -- worry about holes, since no special validity check is needed | |
fbf5a39b AC |
6121 | |
6122 | elsif Is_Enumeration_Type (Typ) | |
6123 | and then Has_Non_Standard_Rep (Typ) | |
6124 | and then Holes_OK | |
6125 | then | |
6126 | return; | |
6127 | ||
ddda9d0f | 6128 | -- No check required on the left-hand side of an assignment |
fbf5a39b AC |
6129 | |
6130 | elsif Nkind (Parent (Expr)) = N_Assignment_Statement | |
6131 | and then Expr = Name (Parent (Expr)) | |
6132 | then | |
6133 | return; | |
6134 | ||
308e6f3a | 6135 | -- No check on a universal real constant. The context will eventually |
f02b8bb8 RD |
6136 | -- convert it to a machine number for some target type, or report an |
6137 | -- illegality. | |
6138 | ||
6139 | elsif Nkind (Expr) = N_Real_Literal | |
6140 | and then Etype (Expr) = Universal_Real | |
6141 | then | |
6142 | return; | |
6143 | ||
308e6f3a | 6144 | -- If the expression denotes a component of a packed boolean array, |
c064e066 RD |
6145 | -- no possible check applies. We ignore the old ACATS chestnuts that |
6146 | -- involve Boolean range True..True. | |
6147 | ||
6148 | -- Note: validity checks are generated for expressions that yield a | |
6149 | -- scalar type, when it is possible to create a value that is outside of | |
6150 | -- the type. If this is a one-bit boolean no such value exists. This is | |
6151 | -- an optimization, and it also prevents compiler blowing up during the | |
6152 | -- elaboration of improperly expanded packed array references. | |
6153 | ||
6154 | elsif Nkind (Expr) = N_Indexed_Component | |
6155 | and then Is_Bit_Packed_Array (Etype (Prefix (Expr))) | |
6156 | and then Root_Type (Etype (Expr)) = Standard_Boolean | |
6157 | then | |
6158 | return; | |
6159 | ||
064f4527 TQ |
6160 | -- For an expression with actions, we want to insert the validity check |
6161 | -- on the final Expression. | |
6162 | ||
6163 | elsif Nkind (Expr) = N_Expression_With_Actions then | |
6164 | Ensure_Valid (Expression (Expr)); | |
6165 | return; | |
6166 | ||
fbf5a39b AC |
6167 | -- An annoying special case. If this is an out parameter of a scalar |
6168 | -- type, then the value is not going to be accessed, therefore it is | |
155f4f34 HK |
6169 | -- inappropriate to do any validity check at the call site. Likewise |
6170 | -- if the parameter is passed by reference. | |
fbf5a39b AC |
6171 | |
6172 | else | |
6173 | -- Only need to worry about scalar types | |
6174 | ||
6175 | if Is_Scalar_Type (Typ) then | |
70482933 RK |
6176 | declare |
6177 | P : Node_Id; | |
6178 | N : Node_Id; | |
6179 | E : Entity_Id; | |
6180 | F : Entity_Id; | |
6181 | A : Node_Id; | |
6182 | L : List_Id; | |
6183 | ||
6184 | begin | |
6185 | -- Find actual argument (which may be a parameter association) | |
6186 | -- and the parent of the actual argument (the call statement) | |
6187 | ||
6188 | N := Expr; | |
6189 | P := Parent (Expr); | |
6190 | ||
6191 | if Nkind (P) = N_Parameter_Association then | |
6192 | N := P; | |
6193 | P := Parent (N); | |
6194 | end if; | |
6195 | ||
155f4f34 HK |
6196 | -- If this is an indirect or dispatching call, get signature |
6197 | -- from the subprogram type. | |
70482933 | 6198 | |
155f4f34 HK |
6199 | if Nkind_In (P, N_Entry_Call_Statement, |
6200 | N_Function_Call, | |
6201 | N_Procedure_Call_Statement) | |
6202 | then | |
6203 | E := Get_Called_Entity (P); | |
70482933 | 6204 | L := Parameter_Associations (P); |
fbf5a39b | 6205 | |
675d6070 | 6206 | -- Only need to worry if there are indeed actuals, and if |
155f4f34 HK |
6207 | -- this could be a subprogram call, otherwise we cannot get |
6208 | -- a match (either we are not an argument, or the mode of | |
6209 | -- the formal is not OUT). This test also filters out the | |
675d6070 | 6210 | -- generic case. |
70482933 | 6211 | |
637a41a5 AC |
6212 | if Is_Non_Empty_List (L) and then Is_Subprogram (E) then |
6213 | ||
675d6070 TQ |
6214 | -- This is the loop through parameters, looking for an |
6215 | -- OUT parameter for which we are the argument. | |
70482933 RK |
6216 | |
6217 | F := First_Formal (E); | |
6218 | A := First (L); | |
70482933 | 6219 | while Present (F) loop |
155f4f34 HK |
6220 | if A = N |
6221 | and then (Ekind (F) = E_Out_Parameter | |
6222 | or else Mechanism (F) = By_Reference) | |
6223 | then | |
70482933 RK |
6224 | return; |
6225 | end if; | |
6226 | ||
6227 | Next_Formal (F); | |
6228 | Next (A); | |
6229 | end loop; | |
6230 | end if; | |
6231 | end if; | |
6232 | end; | |
6233 | end if; | |
6234 | end if; | |
6235 | ||
1c218ac3 | 6236 | -- If this is a boolean expression, only its elementary operands need |
46f52a47 AC |
6237 | -- checking: if they are valid, a boolean or short-circuit operation |
6238 | -- with them will be valid as well. | |
38afef28 AC |
6239 | |
6240 | if Base_Type (Typ) = Standard_Boolean | |
96d2756f | 6241 | and then |
1c218ac3 | 6242 | (Nkind (Expr) in N_Op or else Nkind (Expr) in N_Short_Circuit) |
38afef28 AC |
6243 | then |
6244 | return; | |
6245 | end if; | |
6246 | ||
c064e066 | 6247 | -- If we fall through, a validity check is required |
70482933 | 6248 | |
2934b84a | 6249 | Insert_Valid_Check (Expr, Related_Id, Is_Low_Bound, Is_High_Bound); |
1c3340e6 RD |
6250 | |
6251 | if Is_Entity_Name (Expr) | |
6252 | and then Safe_To_Capture_Value (Expr, Entity (Expr)) | |
6253 | then | |
6254 | Set_Is_Known_Valid (Entity (Expr)); | |
6255 | end if; | |
70482933 RK |
6256 | end Ensure_Valid; |
6257 | ||
6258 | ---------------------- | |
6259 | -- Expr_Known_Valid -- | |
6260 | ---------------------- | |
6261 | ||
6262 | function Expr_Known_Valid (Expr : Node_Id) return Boolean is | |
6263 | Typ : constant Entity_Id := Etype (Expr); | |
6264 | ||
6265 | begin | |
675d6070 TQ |
6266 | -- Non-scalar types are always considered valid, since they never give |
6267 | -- rise to the issues of erroneous or bounded error behavior that are | |
6268 | -- the concern. In formal reference manual terms the notion of validity | |
6269 | -- only applies to scalar types. Note that even when packed arrays are | |
6270 | -- represented using modular types, they are still arrays semantically, | |
6271 | -- so they are also always valid (in particular, the unused bits can be | |
6272 | -- random rubbish without affecting the validity of the array value). | |
70482933 | 6273 | |
8ca597af | 6274 | if not Is_Scalar_Type (Typ) or else Is_Packed_Array_Impl_Type (Typ) then |
70482933 RK |
6275 | return True; |
6276 | ||
6277 | -- If no validity checking, then everything is considered valid | |
6278 | ||
6279 | elsif not Validity_Checks_On then | |
6280 | return True; | |
6281 | ||
6282 | -- Floating-point types are considered valid unless floating-point | |
6283 | -- validity checks have been specifically turned on. | |
6284 | ||
6285 | elsif Is_Floating_Point_Type (Typ) | |
6286 | and then not Validity_Check_Floating_Point | |
6287 | then | |
6288 | return True; | |
6289 | ||
675d6070 TQ |
6290 | -- If the expression is the value of an object that is known to be |
6291 | -- valid, then clearly the expression value itself is valid. | |
70482933 RK |
6292 | |
6293 | elsif Is_Entity_Name (Expr) | |
6294 | and then Is_Known_Valid (Entity (Expr)) | |
fba9ebfc AC |
6295 | |
6296 | -- Exclude volatile variables | |
6297 | ||
6298 | and then not Treat_As_Volatile (Entity (Expr)) | |
70482933 RK |
6299 | then |
6300 | return True; | |
6301 | ||
c064e066 RD |
6302 | -- References to discriminants are always considered valid. The value |
6303 | -- of a discriminant gets checked when the object is built. Within the | |
6304 | -- record, we consider it valid, and it is important to do so, since | |
6305 | -- otherwise we can try to generate bogus validity checks which | |
675d6070 TQ |
6306 | -- reference discriminants out of scope. Discriminants of concurrent |
6307 | -- types are excluded for the same reason. | |
c064e066 RD |
6308 | |
6309 | elsif Is_Entity_Name (Expr) | |
675d6070 | 6310 | and then Denotes_Discriminant (Expr, Check_Concurrent => True) |
c064e066 RD |
6311 | then |
6312 | return True; | |
6313 | ||
675d6070 TQ |
6314 | -- If the type is one for which all values are known valid, then we are |
6315 | -- sure that the value is valid except in the slightly odd case where | |
6316 | -- the expression is a reference to a variable whose size has been | |
6317 | -- explicitly set to a value greater than the object size. | |
70482933 RK |
6318 | |
6319 | elsif Is_Known_Valid (Typ) then | |
6320 | if Is_Entity_Name (Expr) | |
6321 | and then Ekind (Entity (Expr)) = E_Variable | |
6322 | and then Esize (Entity (Expr)) > Esize (Typ) | |
6323 | then | |
6324 | return False; | |
6325 | else | |
6326 | return True; | |
6327 | end if; | |
6328 | ||
6329 | -- Integer and character literals always have valid values, where | |
6330 | -- appropriate these will be range checked in any case. | |
6331 | ||
637a41a5 | 6332 | elsif Nkind_In (Expr, N_Integer_Literal, N_Character_Literal) then |
70482933 | 6333 | return True; |
cf427f02 | 6334 | |
70482933 RK |
6335 | -- If we have a type conversion or a qualification of a known valid |
6336 | -- value, then the result will always be valid. | |
6337 | ||
637a41a5 | 6338 | elsif Nkind_In (Expr, N_Type_Conversion, N_Qualified_Expression) then |
70482933 RK |
6339 | return Expr_Known_Valid (Expression (Expr)); |
6340 | ||
162c21d9 AC |
6341 | -- Case of expression is a non-floating-point operator. In this case we |
6342 | -- can assume the result is valid the generated code for the operator | |
6343 | -- will include whatever checks are needed (e.g. range checks) to ensure | |
6344 | -- validity. This assumption does not hold for the floating-point case, | |
6345 | -- since floating-point operators can generate Infinite or NaN results | |
6346 | -- which are considered invalid. | |
6347 | ||
6348 | -- Historical note: in older versions, the exemption of floating-point | |
6349 | -- types from this assumption was done only in cases where the parent | |
6350 | -- was an assignment, function call or parameter association. Presumably | |
6351 | -- the idea was that in other contexts, the result would be checked | |
6352 | -- elsewhere, but this list of cases was missing tests (at least the | |
6353 | -- N_Object_Declaration case, as shown by a reported missing validity | |
6354 | -- check), and it is not clear why function calls but not procedure | |
6355 | -- calls were tested for. It really seems more accurate and much | |
6356 | -- safer to recognize that expressions which are the result of a | |
6357 | -- floating-point operator can never be assumed to be valid. | |
6358 | ||
6359 | elsif Nkind (Expr) in N_Op and then not Is_Floating_Point_Type (Typ) then | |
6360 | return True; | |
28e4d64e | 6361 | |
675d6070 TQ |
6362 | -- The result of a membership test is always valid, since it is true or |
6363 | -- false, there are no other possibilities. | |
c064e066 RD |
6364 | |
6365 | elsif Nkind (Expr) in N_Membership_Test then | |
6366 | return True; | |
6367 | ||
70482933 RK |
6368 | -- For all other cases, we do not know the expression is valid |
6369 | ||
6370 | else | |
6371 | return False; | |
6372 | end if; | |
6373 | end Expr_Known_Valid; | |
6374 | ||
fbf5a39b AC |
6375 | ---------------- |
6376 | -- Find_Check -- | |
6377 | ---------------- | |
6378 | ||
6379 | procedure Find_Check | |
6380 | (Expr : Node_Id; | |
6381 | Check_Type : Character; | |
6382 | Target_Type : Entity_Id; | |
6383 | Entry_OK : out Boolean; | |
6384 | Check_Num : out Nat; | |
6385 | Ent : out Entity_Id; | |
6386 | Ofs : out Uint) | |
6387 | is | |
6388 | function Within_Range_Of | |
6389 | (Target_Type : Entity_Id; | |
6b6fcd3e | 6390 | Check_Type : Entity_Id) return Boolean; |
fbf5a39b AC |
6391 | -- Given a requirement for checking a range against Target_Type, and |
6392 | -- and a range Check_Type against which a check has already been made, | |
6393 | -- determines if the check against check type is sufficient to ensure | |
6394 | -- that no check against Target_Type is required. | |
6395 | ||
6396 | --------------------- | |
6397 | -- Within_Range_Of -- | |
6398 | --------------------- | |
6399 | ||
6400 | function Within_Range_Of | |
6401 | (Target_Type : Entity_Id; | |
6b6fcd3e | 6402 | Check_Type : Entity_Id) return Boolean |
fbf5a39b AC |
6403 | is |
6404 | begin | |
6405 | if Target_Type = Check_Type then | |
6406 | return True; | |
6407 | ||
6408 | else | |
6409 | declare | |
6410 | Tlo : constant Node_Id := Type_Low_Bound (Target_Type); | |
6411 | Thi : constant Node_Id := Type_High_Bound (Target_Type); | |
6412 | Clo : constant Node_Id := Type_Low_Bound (Check_Type); | |
6413 | Chi : constant Node_Id := Type_High_Bound (Check_Type); | |
6414 | ||
6415 | begin | |
6416 | if (Tlo = Clo | |
6417 | or else (Compile_Time_Known_Value (Tlo) | |
6418 | and then | |
6419 | Compile_Time_Known_Value (Clo) | |
6420 | and then | |
6421 | Expr_Value (Clo) >= Expr_Value (Tlo))) | |
6422 | and then | |
6423 | (Thi = Chi | |
6424 | or else (Compile_Time_Known_Value (Thi) | |
6425 | and then | |
6426 | Compile_Time_Known_Value (Chi) | |
6427 | and then | |
6428 | Expr_Value (Chi) <= Expr_Value (Clo))) | |
6429 | then | |
6430 | return True; | |
6431 | else | |
6432 | return False; | |
6433 | end if; | |
6434 | end; | |
6435 | end if; | |
6436 | end Within_Range_Of; | |
6437 | ||
6438 | -- Start of processing for Find_Check | |
6439 | ||
6440 | begin | |
75ba322d | 6441 | -- Establish default, in case no entry is found |
fbf5a39b AC |
6442 | |
6443 | Check_Num := 0; | |
6444 | ||
6445 | -- Case of expression is simple entity reference | |
6446 | ||
6447 | if Is_Entity_Name (Expr) then | |
6448 | Ent := Entity (Expr); | |
6449 | Ofs := Uint_0; | |
6450 | ||
6451 | -- Case of expression is entity + known constant | |
6452 | ||
6453 | elsif Nkind (Expr) = N_Op_Add | |
6454 | and then Compile_Time_Known_Value (Right_Opnd (Expr)) | |
6455 | and then Is_Entity_Name (Left_Opnd (Expr)) | |
6456 | then | |
6457 | Ent := Entity (Left_Opnd (Expr)); | |
6458 | Ofs := Expr_Value (Right_Opnd (Expr)); | |
6459 | ||
6460 | -- Case of expression is entity - known constant | |
6461 | ||
6462 | elsif Nkind (Expr) = N_Op_Subtract | |
6463 | and then Compile_Time_Known_Value (Right_Opnd (Expr)) | |
6464 | and then Is_Entity_Name (Left_Opnd (Expr)) | |
6465 | then | |
6466 | Ent := Entity (Left_Opnd (Expr)); | |
6467 | Ofs := UI_Negate (Expr_Value (Right_Opnd (Expr))); | |
6468 | ||
6469 | -- Any other expression is not of the right form | |
6470 | ||
6471 | else | |
6472 | Ent := Empty; | |
6473 | Ofs := Uint_0; | |
6474 | Entry_OK := False; | |
6475 | return; | |
6476 | end if; | |
6477 | ||
675d6070 TQ |
6478 | -- Come here with expression of appropriate form, check if entity is an |
6479 | -- appropriate one for our purposes. | |
fbf5a39b AC |
6480 | |
6481 | if (Ekind (Ent) = E_Variable | |
f2cbd970 | 6482 | or else Is_Constant_Object (Ent)) |
fbf5a39b AC |
6483 | and then not Is_Library_Level_Entity (Ent) |
6484 | then | |
6485 | Entry_OK := True; | |
6486 | else | |
6487 | Entry_OK := False; | |
6488 | return; | |
6489 | end if; | |
6490 | ||
6491 | -- See if there is matching check already | |
6492 | ||
6493 | for J in reverse 1 .. Num_Saved_Checks loop | |
6494 | declare | |
6495 | SC : Saved_Check renames Saved_Checks (J); | |
fbf5a39b AC |
6496 | begin |
6497 | if SC.Killed = False | |
6498 | and then SC.Entity = Ent | |
6499 | and then SC.Offset = Ofs | |
6500 | and then SC.Check_Type = Check_Type | |
6501 | and then Within_Range_Of (Target_Type, SC.Target_Type) | |
6502 | then | |
6503 | Check_Num := J; | |
6504 | return; | |
6505 | end if; | |
6506 | end; | |
6507 | end loop; | |
6508 | ||
6509 | -- If we fall through entry was not found | |
6510 | ||
fbf5a39b AC |
6511 | return; |
6512 | end Find_Check; | |
6513 | ||
6514 | --------------------------------- | |
6515 | -- Generate_Discriminant_Check -- | |
6516 | --------------------------------- | |
6517 | ||
6518 | -- Note: the code for this procedure is derived from the | |
675d6070 | 6519 | -- Emit_Discriminant_Check Routine in trans.c. |
fbf5a39b AC |
6520 | |
6521 | procedure Generate_Discriminant_Check (N : Node_Id) is | |
6522 | Loc : constant Source_Ptr := Sloc (N); | |
6523 | Pref : constant Node_Id := Prefix (N); | |
6524 | Sel : constant Node_Id := Selector_Name (N); | |
6525 | ||
6526 | Orig_Comp : constant Entity_Id := | |
15f0f591 | 6527 | Original_Record_Component (Entity (Sel)); |
fbf5a39b AC |
6528 | -- The original component to be checked |
6529 | ||
6530 | Discr_Fct : constant Entity_Id := | |
15f0f591 | 6531 | Discriminant_Checking_Func (Orig_Comp); |
fbf5a39b AC |
6532 | -- The discriminant checking function |
6533 | ||
6534 | Discr : Entity_Id; | |
6535 | -- One discriminant to be checked in the type | |
6536 | ||
6537 | Real_Discr : Entity_Id; | |
6538 | -- Actual discriminant in the call | |
6539 | ||
6540 | Pref_Type : Entity_Id; | |
6541 | -- Type of relevant prefix (ignoring private/access stuff) | |
6542 | ||
6543 | Args : List_Id; | |
6544 | -- List of arguments for function call | |
6545 | ||
6546 | Formal : Entity_Id; | |
675d6070 TQ |
6547 | -- Keep track of the formal corresponding to the actual we build for |
6548 | -- each discriminant, in order to be able to perform the necessary type | |
6549 | -- conversions. | |
fbf5a39b AC |
6550 | |
6551 | Scomp : Node_Id; | |
6552 | -- Selected component reference for checking function argument | |
6553 | ||
6554 | begin | |
6555 | Pref_Type := Etype (Pref); | |
6556 | ||
6557 | -- Force evaluation of the prefix, so that it does not get evaluated | |
6558 | -- twice (once for the check, once for the actual reference). Such a | |
637a41a5 AC |
6559 | -- double evaluation is always a potential source of inefficiency, and |
6560 | -- is functionally incorrect in the volatile case, or when the prefix | |
2cc2e964 AC |
6561 | -- may have side effects. A nonvolatile entity or a component of a |
6562 | -- nonvolatile entity requires no evaluation. | |
fbf5a39b AC |
6563 | |
6564 | if Is_Entity_Name (Pref) then | |
6565 | if Treat_As_Volatile (Entity (Pref)) then | |
6566 | Force_Evaluation (Pref, Name_Req => True); | |
6567 | end if; | |
6568 | ||
6569 | elsif Treat_As_Volatile (Etype (Pref)) then | |
637a41a5 | 6570 | Force_Evaluation (Pref, Name_Req => True); |
fbf5a39b AC |
6571 | |
6572 | elsif Nkind (Pref) = N_Selected_Component | |
6573 | and then Is_Entity_Name (Prefix (Pref)) | |
6574 | then | |
6575 | null; | |
6576 | ||
6577 | else | |
6578 | Force_Evaluation (Pref, Name_Req => True); | |
6579 | end if; | |
6580 | ||
6581 | -- For a tagged type, use the scope of the original component to | |
6582 | -- obtain the type, because ??? | |
6583 | ||
6584 | if Is_Tagged_Type (Scope (Orig_Comp)) then | |
6585 | Pref_Type := Scope (Orig_Comp); | |
6586 | ||
675d6070 TQ |
6587 | -- For an untagged derived type, use the discriminants of the parent |
6588 | -- which have been renamed in the derivation, possibly by a one-to-many | |
1fb63e89 | 6589 | -- discriminant constraint. For untagged type, initially get the Etype |
675d6070 | 6590 | -- of the prefix |
fbf5a39b AC |
6591 | |
6592 | else | |
6593 | if Is_Derived_Type (Pref_Type) | |
6594 | and then Number_Discriminants (Pref_Type) /= | |
6595 | Number_Discriminants (Etype (Base_Type (Pref_Type))) | |
6596 | then | |
6597 | Pref_Type := Etype (Base_Type (Pref_Type)); | |
6598 | end if; | |
6599 | end if; | |
6600 | ||
6601 | -- We definitely should have a checking function, This routine should | |
6602 | -- not be called if no discriminant checking function is present. | |
6603 | ||
6604 | pragma Assert (Present (Discr_Fct)); | |
6605 | ||
6606 | -- Create the list of the actual parameters for the call. This list | |
6607 | -- is the list of the discriminant fields of the record expression to | |
6608 | -- be discriminant checked. | |
6609 | ||
6610 | Args := New_List; | |
6611 | Formal := First_Formal (Discr_Fct); | |
6612 | Discr := First_Discriminant (Pref_Type); | |
6613 | while Present (Discr) loop | |
6614 | ||
6615 | -- If we have a corresponding discriminant field, and a parent | |
6616 | -- subtype is present, then we want to use the corresponding | |
6617 | -- discriminant since this is the one with the useful value. | |
6618 | ||
6619 | if Present (Corresponding_Discriminant (Discr)) | |
6620 | and then Ekind (Pref_Type) = E_Record_Type | |
6621 | and then Present (Parent_Subtype (Pref_Type)) | |
6622 | then | |
6623 | Real_Discr := Corresponding_Discriminant (Discr); | |
6624 | else | |
6625 | Real_Discr := Discr; | |
6626 | end if; | |
6627 | ||
6628 | -- Construct the reference to the discriminant | |
6629 | ||
6630 | Scomp := | |
6631 | Make_Selected_Component (Loc, | |
6632 | Prefix => | |
6633 | Unchecked_Convert_To (Pref_Type, | |
6634 | Duplicate_Subexpr (Pref)), | |
6635 | Selector_Name => New_Occurrence_Of (Real_Discr, Loc)); | |
6636 | ||
6637 | -- Manually analyze and resolve this selected component. We really | |
6638 | -- want it just as it appears above, and do not want the expander | |
675d6070 TQ |
6639 | -- playing discriminal games etc with this reference. Then we append |
6640 | -- the argument to the list we are gathering. | |
fbf5a39b AC |
6641 | |
6642 | Set_Etype (Scomp, Etype (Real_Discr)); | |
6643 | Set_Analyzed (Scomp, True); | |
6644 | Append_To (Args, Convert_To (Etype (Formal), Scomp)); | |
6645 | ||
6646 | Next_Formal_With_Extras (Formal); | |
6647 | Next_Discriminant (Discr); | |
6648 | end loop; | |
6649 | ||
6650 | -- Now build and insert the call | |
6651 | ||
6652 | Insert_Action (N, | |
6653 | Make_Raise_Constraint_Error (Loc, | |
6654 | Condition => | |
6655 | Make_Function_Call (Loc, | |
637a41a5 | 6656 | Name => New_Occurrence_Of (Discr_Fct, Loc), |
fbf5a39b AC |
6657 | Parameter_Associations => Args), |
6658 | Reason => CE_Discriminant_Check_Failed)); | |
6659 | end Generate_Discriminant_Check; | |
6660 | ||
15ce9ca2 AC |
6661 | --------------------------- |
6662 | -- Generate_Index_Checks -- | |
6663 | --------------------------- | |
fbf5a39b AC |
6664 | |
6665 | procedure Generate_Index_Checks (N : Node_Id) is | |
4230bdb7 AC |
6666 | |
6667 | function Entity_Of_Prefix return Entity_Id; | |
6668 | -- Returns the entity of the prefix of N (or Empty if not found) | |
6669 | ||
8ed68165 AC |
6670 | ---------------------- |
6671 | -- Entity_Of_Prefix -- | |
6672 | ---------------------- | |
6673 | ||
4230bdb7 | 6674 | function Entity_Of_Prefix return Entity_Id is |
0d53d36b AC |
6675 | P : Node_Id; |
6676 | ||
4230bdb7 | 6677 | begin |
0d53d36b | 6678 | P := Prefix (N); |
4230bdb7 AC |
6679 | while not Is_Entity_Name (P) loop |
6680 | if not Nkind_In (P, N_Selected_Component, | |
6681 | N_Indexed_Component) | |
6682 | then | |
6683 | return Empty; | |
6684 | end if; | |
6685 | ||
6686 | P := Prefix (P); | |
6687 | end loop; | |
6688 | ||
6689 | return Entity (P); | |
6690 | end Entity_Of_Prefix; | |
6691 | ||
6692 | -- Local variables | |
6693 | ||
6694 | Loc : constant Source_Ptr := Sloc (N); | |
6695 | A : constant Node_Id := Prefix (N); | |
6696 | A_Ent : constant Entity_Id := Entity_Of_Prefix; | |
6697 | Sub : Node_Id; | |
fbf5a39b | 6698 | |
8ed68165 AC |
6699 | -- Start of processing for Generate_Index_Checks |
6700 | ||
fbf5a39b | 6701 | begin |
4230bdb7 AC |
6702 | -- Ignore call if the prefix is not an array since we have a serious |
6703 | -- error in the sources. Ignore it also if index checks are suppressed | |
6704 | -- for array object or type. | |
c064e066 | 6705 | |
4230bdb7 | 6706 | if not Is_Array_Type (Etype (A)) |
637a41a5 | 6707 | or else (Present (A_Ent) and then Index_Checks_Suppressed (A_Ent)) |
c064e066 RD |
6708 | or else Index_Checks_Suppressed (Etype (A)) |
6709 | then | |
6710 | return; | |
3a3af4c3 AC |
6711 | |
6712 | -- The indexed component we are dealing with contains 'Loop_Entry in its | |
6713 | -- prefix. This case arises when analysis has determined that constructs | |
6714 | -- such as | |
6715 | ||
6716 | -- Prefix'Loop_Entry (Expr) | |
6717 | -- Prefix'Loop_Entry (Expr1, Expr2, ... ExprN) | |
6718 | ||
6719 | -- require rewriting for error detection purposes. A side effect of this | |
6720 | -- action is the generation of index checks that mention 'Loop_Entry. | |
6721 | -- Delay the generation of the check until 'Loop_Entry has been properly | |
6722 | -- expanded. This is done in Expand_Loop_Entry_Attributes. | |
6723 | ||
6724 | elsif Nkind (Prefix (N)) = N_Attribute_Reference | |
6725 | and then Attribute_Name (Prefix (N)) = Name_Loop_Entry | |
6726 | then | |
6727 | return; | |
c064e066 RD |
6728 | end if; |
6729 | ||
4230bdb7 AC |
6730 | -- Generate a raise of constraint error with the appropriate reason and |
6731 | -- a condition of the form: | |
6732 | ||
8ed68165 | 6733 | -- Base_Type (Sub) not in Array'Range (Subscript) |
4230bdb7 AC |
6734 | |
6735 | -- Note that the reason we generate the conversion to the base type here | |
6736 | -- is that we definitely want the range check to take place, even if it | |
6737 | -- looks like the subtype is OK. Optimization considerations that allow | |
6738 | -- us to omit the check have already been taken into account in the | |
6739 | -- setting of the Do_Range_Check flag earlier on. | |
c064e066 | 6740 | |
fbf5a39b | 6741 | Sub := First (Expressions (N)); |
4230bdb7 AC |
6742 | |
6743 | -- Handle string literals | |
6744 | ||
6745 | if Ekind (Etype (A)) = E_String_Literal_Subtype then | |
fbf5a39b AC |
6746 | if Do_Range_Check (Sub) then |
6747 | Set_Do_Range_Check (Sub, False); | |
6748 | ||
4230bdb7 AC |
6749 | -- For string literals we obtain the bounds of the string from the |
6750 | -- associated subtype. | |
fbf5a39b | 6751 | |
4230bdb7 | 6752 | Insert_Action (N, |
d7a44b14 AC |
6753 | Make_Raise_Constraint_Error (Loc, |
6754 | Condition => | |
6755 | Make_Not_In (Loc, | |
6756 | Left_Opnd => | |
6757 | Convert_To (Base_Type (Etype (Sub)), | |
6758 | Duplicate_Subexpr_Move_Checks (Sub)), | |
6759 | Right_Opnd => | |
6760 | Make_Attribute_Reference (Loc, | |
e4494292 | 6761 | Prefix => New_Occurrence_Of (Etype (A), Loc), |
d7a44b14 AC |
6762 | Attribute_Name => Name_Range)), |
6763 | Reason => CE_Index_Check_Failed)); | |
4230bdb7 | 6764 | end if; |
fbf5a39b | 6765 | |
4230bdb7 | 6766 | -- General case |
fbf5a39b | 6767 | |
4230bdb7 AC |
6768 | else |
6769 | declare | |
6770 | A_Idx : Node_Id := Empty; | |
6771 | A_Range : Node_Id; | |
6772 | Ind : Nat; | |
6773 | Num : List_Id; | |
6774 | Range_N : Node_Id; | |
fbf5a39b | 6775 | |
4230bdb7 AC |
6776 | begin |
6777 | A_Idx := First_Index (Etype (A)); | |
6778 | Ind := 1; | |
6779 | while Present (Sub) loop | |
6780 | if Do_Range_Check (Sub) then | |
6781 | Set_Do_Range_Check (Sub, False); | |
fbf5a39b | 6782 | |
4230bdb7 | 6783 | -- Force evaluation except for the case of a simple name of |
2cc2e964 | 6784 | -- a nonvolatile entity. |
fbf5a39b | 6785 | |
4230bdb7 AC |
6786 | if not Is_Entity_Name (Sub) |
6787 | or else Treat_As_Volatile (Entity (Sub)) | |
6788 | then | |
6789 | Force_Evaluation (Sub); | |
6790 | end if; | |
fbf5a39b | 6791 | |
4230bdb7 AC |
6792 | if Nkind (A_Idx) = N_Range then |
6793 | A_Range := A_Idx; | |
6794 | ||
6795 | elsif Nkind (A_Idx) = N_Identifier | |
6796 | or else Nkind (A_Idx) = N_Expanded_Name | |
6797 | then | |
6798 | A_Range := Scalar_Range (Entity (A_Idx)); | |
6799 | ||
6800 | else pragma Assert (Nkind (A_Idx) = N_Subtype_Indication); | |
6801 | A_Range := Range_Expression (Constraint (A_Idx)); | |
6802 | end if; | |
6803 | ||
6804 | -- For array objects with constant bounds we can generate | |
6805 | -- the index check using the bounds of the type of the index | |
6806 | ||
6807 | if Present (A_Ent) | |
6808 | and then Ekind (A_Ent) = E_Variable | |
6809 | and then Is_Constant_Bound (Low_Bound (A_Range)) | |
6810 | and then Is_Constant_Bound (High_Bound (A_Range)) | |
6811 | then | |
6812 | Range_N := | |
6813 | Make_Attribute_Reference (Loc, | |
8ed68165 | 6814 | Prefix => |
e4494292 | 6815 | New_Occurrence_Of (Etype (A_Idx), Loc), |
4230bdb7 AC |
6816 | Attribute_Name => Name_Range); |
6817 | ||
6818 | -- For arrays with non-constant bounds we cannot generate | |
6819 | -- the index check using the bounds of the type of the index | |
6820 | -- since it may reference discriminants of some enclosing | |
6821 | -- type. We obtain the bounds directly from the prefix | |
6822 | -- object. | |
6823 | ||
6824 | else | |
6825 | if Ind = 1 then | |
6826 | Num := No_List; | |
6827 | else | |
6828 | Num := New_List (Make_Integer_Literal (Loc, Ind)); | |
6829 | end if; | |
6830 | ||
6831 | Range_N := | |
6832 | Make_Attribute_Reference (Loc, | |
6833 | Prefix => | |
6834 | Duplicate_Subexpr_Move_Checks (A, Name_Req => True), | |
6835 | Attribute_Name => Name_Range, | |
6836 | Expressions => Num); | |
6837 | end if; | |
6838 | ||
6839 | Insert_Action (N, | |
d7a44b14 AC |
6840 | Make_Raise_Constraint_Error (Loc, |
6841 | Condition => | |
6842 | Make_Not_In (Loc, | |
6843 | Left_Opnd => | |
6844 | Convert_To (Base_Type (Etype (Sub)), | |
6845 | Duplicate_Subexpr_Move_Checks (Sub)), | |
6846 | Right_Opnd => Range_N), | |
6847 | Reason => CE_Index_Check_Failed)); | |
4230bdb7 AC |
6848 | end if; |
6849 | ||
6850 | A_Idx := Next_Index (A_Idx); | |
6851 | Ind := Ind + 1; | |
6852 | Next (Sub); | |
6853 | end loop; | |
6854 | end; | |
6855 | end if; | |
fbf5a39b AC |
6856 | end Generate_Index_Checks; |
6857 | ||
6858 | -------------------------- | |
6859 | -- Generate_Range_Check -- | |
6860 | -------------------------- | |
6861 | ||
6862 | procedure Generate_Range_Check | |
6863 | (N : Node_Id; | |
6864 | Target_Type : Entity_Id; | |
6865 | Reason : RT_Exception_Code) | |
6866 | is | |
6867 | Loc : constant Source_Ptr := Sloc (N); | |
6868 | Source_Type : constant Entity_Id := Etype (N); | |
6869 | Source_Base_Type : constant Entity_Id := Base_Type (Source_Type); | |
6870 | Target_Base_Type : constant Entity_Id := Base_Type (Target_Type); | |
6871 | ||
67460d45 EB |
6872 | procedure Convert_And_Check_Range (Suppress : Check_Id); |
6873 | -- Convert N to the target base type and save the result in a temporary. | |
6874 | -- The action is analyzed using the default checks as modified by the | |
6875 | -- given Suppress argument. Then check the converted value against the | |
6876 | -- range of the target subtype. | |
f5655e4a | 6877 | |
b6621d10 AC |
6878 | ----------------------------- |
6879 | -- Convert_And_Check_Range -- | |
6880 | ----------------------------- | |
f5655e4a | 6881 | |
67460d45 EB |
6882 | procedure Convert_And_Check_Range (Suppress : Check_Id) is |
6883 | Tnn : constant Entity_Id := Make_Temporary (Loc, 'T', N); | |
6884 | Conv_N : Node_Id; | |
f5655e4a | 6885 | |
b6621d10 | 6886 | begin |
f20b5ef4 JM |
6887 | -- For enumeration types with non-standard representation this is a |
6888 | -- direct conversion from the enumeration type to the target integer | |
6889 | -- type, which is treated by the back end as a normal integer type | |
6890 | -- conversion, treating the enumeration type as an integer, which is | |
6891 | -- exactly what we want. We set Conversion_OK to make sure that the | |
6892 | -- analyzer does not complain about what otherwise might be an | |
6893 | -- illegal conversion. | |
6894 | ||
6895 | if Is_Enumeration_Type (Source_Base_Type) | |
6896 | and then Present (Enum_Pos_To_Rep (Source_Base_Type)) | |
6897 | and then Is_Integer_Type (Target_Base_Type) | |
6898 | then | |
67460d45 | 6899 | Conv_N := OK_Convert_To (Target_Base_Type, Duplicate_Subexpr (N)); |
f20b5ef4 | 6900 | else |
67460d45 | 6901 | Conv_N := Convert_To (Target_Base_Type, Duplicate_Subexpr (N)); |
f20b5ef4 JM |
6902 | end if; |
6903 | ||
67460d45 EB |
6904 | -- We make a temporary to hold the value of the conversion to the |
6905 | -- target base type, and then do the test against this temporary. | |
6906 | -- N itself is replaced by an occurrence of Tnn and followed by | |
6907 | -- the explicit range check. | |
f5655e4a | 6908 | |
b6621d10 AC |
6909 | -- Tnn : constant Target_Base_Type := Target_Base_Type (N); |
6910 | -- [constraint_error when Tnn not in Target_Type] | |
67460d45 | 6911 | -- Tnn |
b6621d10 | 6912 | |
f5655e4a AC |
6913 | Insert_Actions (N, New_List ( |
6914 | Make_Object_Declaration (Loc, | |
6915 | Defining_Identifier => Tnn, | |
6916 | Object_Definition => New_Occurrence_Of (Target_Base_Type, Loc), | |
6917 | Constant_Present => True, | |
67460d45 | 6918 | Expression => Conv_N), |
f5655e4a AC |
6919 | |
6920 | Make_Raise_Constraint_Error (Loc, | |
6921 | Condition => | |
6922 | Make_Not_In (Loc, | |
6923 | Left_Opnd => New_Occurrence_Of (Tnn, Loc), | |
6924 | Right_Opnd => New_Occurrence_Of (Target_Type, Loc)), | |
6925 | Reason => Reason)), | |
67460d45 | 6926 | Suppress => Suppress); |
f5655e4a AC |
6927 | |
6928 | Rewrite (N, New_Occurrence_Of (Tnn, Loc)); | |
6929 | ||
6930 | -- Set the type of N, because the declaration for Tnn might not | |
6931 | -- be analyzed yet, as is the case if N appears within a record | |
6932 | -- declaration, as a discriminant constraint or expression. | |
6933 | ||
6934 | Set_Etype (N, Target_Base_Type); | |
6935 | end Convert_And_Check_Range; | |
6936 | ||
6937 | -- Start of processing for Generate_Range_Check | |
6938 | ||
fbf5a39b | 6939 | begin |
675d6070 TQ |
6940 | -- First special case, if the source type is already within the range |
6941 | -- of the target type, then no check is needed (probably we should have | |
6942 | -- stopped Do_Range_Check from being set in the first place, but better | |
67460d45 | 6943 | -- late than never in preventing junk code and junk flag settings). |
fbf5a39b | 6944 | |
c27f2f15 | 6945 | if In_Subrange_Of (Source_Type, Target_Type) |
347c766a RD |
6946 | |
6947 | -- We do NOT apply this if the source node is a literal, since in this | |
6948 | -- case the literal has already been labeled as having the subtype of | |
6949 | -- the target. | |
6950 | ||
fbf5a39b | 6951 | and then not |
347c766a | 6952 | (Nkind_In (N, N_Integer_Literal, N_Real_Literal, N_Character_Literal) |
fbf5a39b | 6953 | or else |
347c766a RD |
6954 | (Is_Entity_Name (N) |
6955 | and then Ekind (Entity (N)) = E_Enumeration_Literal)) | |
fbf5a39b | 6956 | then |
edab6088 | 6957 | Set_Do_Range_Check (N, False); |
fbf5a39b AC |
6958 | return; |
6959 | end if; | |
6960 | ||
edab6088 RD |
6961 | -- Here a check is needed. If the expander is not active, or if we are |
6962 | -- in GNATProve mode, then simply set the Do_Range_Check flag and we | |
6963 | -- are done. In both these cases, we just want to see the range check | |
6964 | -- flag set, we do not want to generate the explicit range check code. | |
6965 | ||
6966 | if GNATprove_Mode or else not Expander_Active then | |
68c8d72a | 6967 | Set_Do_Range_Check (N); |
edab6088 RD |
6968 | return; |
6969 | end if; | |
6970 | ||
6971 | -- Here we will generate an explicit range check, so we don't want to | |
6972 | -- set the Do_Range check flag, since the range check is taken care of | |
6973 | -- by the code we will generate. | |
6974 | ||
6975 | Set_Do_Range_Check (N, False); | |
6976 | ||
6977 | -- Force evaluation of the node, so that it does not get evaluated twice | |
6978 | -- (once for the check, once for the actual reference). Such a double | |
6979 | -- evaluation is always a potential source of inefficiency, and is | |
6980 | -- functionally incorrect in the volatile case. | |
fbf5a39b | 6981 | |
967947ed PMR |
6982 | -- We skip the evaluation of attribute references because, after these |
6983 | -- runtime checks are generated, the expander may need to rewrite this | |
6984 | -- node (for example, see Attribute_Max_Size_In_Storage_Elements in | |
6985 | -- Expand_N_Attribute_Reference). | |
6986 | ||
6987 | if Nkind (N) /= N_Attribute_Reference | |
6988 | and then (not Is_Entity_Name (N) | |
c581c520 | 6989 | or else Treat_As_Volatile (Entity (N))) |
967947ed PMR |
6990 | then |
6991 | Force_Evaluation (N, Mode => Strict); | |
fbf5a39b AC |
6992 | end if; |
6993 | ||
675d6070 TQ |
6994 | -- The easiest case is when Source_Base_Type and Target_Base_Type are |
6995 | -- the same since in this case we can simply do a direct check of the | |
6996 | -- value of N against the bounds of Target_Type. | |
fbf5a39b AC |
6997 | |
6998 | -- [constraint_error when N not in Target_Type] | |
6999 | ||
7000 | -- Note: this is by far the most common case, for example all cases of | |
7001 | -- checks on the RHS of assignments are in this category, but not all | |
7002 | -- cases are like this. Notably conversions can involve two types. | |
7003 | ||
7004 | if Source_Base_Type = Target_Base_Type then | |
96e90ac1 RD |
7005 | |
7006 | -- Insert the explicit range check. Note that we suppress checks for | |
7007 | -- this code, since we don't want a recursive range check popping up. | |
7008 | ||
fbf5a39b AC |
7009 | Insert_Action (N, |
7010 | Make_Raise_Constraint_Error (Loc, | |
7011 | Condition => | |
7012 | Make_Not_In (Loc, | |
7013 | Left_Opnd => Duplicate_Subexpr (N), | |
7014 | Right_Opnd => New_Occurrence_Of (Target_Type, Loc)), | |
96e90ac1 RD |
7015 | Reason => Reason), |
7016 | Suppress => All_Checks); | |
fbf5a39b AC |
7017 | |
7018 | -- Next test for the case where the target type is within the bounds | |
7019 | -- of the base type of the source type, since in this case we can | |
7c2a44ae | 7020 | -- simply convert the bounds of the target type to this base type |
67460d45 | 7021 | -- to do the test. |
fbf5a39b AC |
7022 | |
7023 | -- [constraint_error when N not in | |
7024 | -- Source_Base_Type (Target_Type'First) | |
7025 | -- .. | |
7026 | -- Source_Base_Type(Target_Type'Last))] | |
7027 | ||
ddda9d0f | 7028 | -- The conversions will always work and need no check |
fbf5a39b | 7029 | |
d79e621a GD |
7030 | -- Unchecked_Convert_To is used instead of Convert_To to handle the case |
7031 | -- of converting from an enumeration value to an integer type, such as | |
7032 | -- occurs for the case of generating a range check on Enum'Val(Exp) | |
7033 | -- (which used to be handled by gigi). This is OK, since the conversion | |
7034 | -- itself does not require a check. | |
7035 | ||
c27f2f15 | 7036 | elsif In_Subrange_Of (Target_Type, Source_Base_Type) then |
96e90ac1 RD |
7037 | |
7038 | -- Insert the explicit range check. Note that we suppress checks for | |
7039 | -- this code, since we don't want a recursive range check popping up. | |
7040 | ||
f5655e4a AC |
7041 | if Is_Discrete_Type (Source_Base_Type) |
7042 | and then | |
7043 | Is_Discrete_Type (Target_Base_Type) | |
7044 | then | |
7045 | Insert_Action (N, | |
7046 | Make_Raise_Constraint_Error (Loc, | |
7047 | Condition => | |
7048 | Make_Not_In (Loc, | |
7049 | Left_Opnd => Duplicate_Subexpr (N), | |
7050 | ||
7051 | Right_Opnd => | |
7052 | Make_Range (Loc, | |
7053 | Low_Bound => | |
7054 | Unchecked_Convert_To (Source_Base_Type, | |
7055 | Make_Attribute_Reference (Loc, | |
7056 | Prefix => | |
7057 | New_Occurrence_Of (Target_Type, Loc), | |
7058 | Attribute_Name => Name_First)), | |
7059 | ||
7060 | High_Bound => | |
7061 | Unchecked_Convert_To (Source_Base_Type, | |
7062 | Make_Attribute_Reference (Loc, | |
7063 | Prefix => | |
7064 | New_Occurrence_Of (Target_Type, Loc), | |
7065 | Attribute_Name => Name_Last)))), | |
7066 | Reason => Reason), | |
7067 | Suppress => All_Checks); | |
fbf5a39b | 7068 | |
f5655e4a | 7069 | -- For conversions involving at least one type that is not discrete, |
67460d45 EB |
7070 | -- first convert to the target base type and then generate the range |
7071 | -- check. This avoids problems with values that are close to a bound | |
7072 | -- of the target type that would fail a range check when done in a | |
7073 | -- larger source type before converting but pass if converted with | |
f5655e4a AC |
7074 | -- rounding and then checked (such as in float-to-float conversions). |
7075 | ||
67460d45 EB |
7076 | -- Note that overflow checks are not suppressed for this code because |
7077 | -- we do not know whether the source type is in range of the target | |
7078 | -- base type (unlike in the next case below). | |
7079 | ||
f5655e4a | 7080 | else |
67460d45 | 7081 | Convert_And_Check_Range (Suppress => Range_Check); |
f5655e4a | 7082 | end if; |
fbf5a39b | 7083 | |
929d5203 | 7084 | -- Note that at this stage we know that the Target_Base_Type is not in |
675d6070 TQ |
7085 | -- the range of the Source_Base_Type (since even the Target_Type itself |
7086 | -- is not in this range). It could still be the case that Source_Type is | |
7087 | -- in range of the target base type since we have not checked that case. | |
fbf5a39b | 7088 | |
675d6070 | 7089 | -- If that is the case, we can freely convert the source to the target, |
67460d45 EB |
7090 | -- and then test the target result against the bounds. Note that checks |
7091 | -- are suppressed for this code, since we don't want a recursive range | |
7092 | -- check popping up. | |
fbf5a39b | 7093 | |
c27f2f15 | 7094 | elsif In_Subrange_Of (Source_Type, Target_Base_Type) then |
67460d45 | 7095 | Convert_And_Check_Range (Suppress => All_Checks); |
fbf5a39b AC |
7096 | |
7097 | -- At this stage, we know that we have two scalar types, which are | |
7098 | -- directly convertible, and where neither scalar type has a base | |
7099 | -- range that is in the range of the other scalar type. | |
7100 | ||
7101 | -- The only way this can happen is with a signed and unsigned type. | |
7102 | -- So test for these two cases: | |
7103 | ||
7104 | else | |
7105 | -- Case of the source is unsigned and the target is signed | |
7106 | ||
7107 | if Is_Unsigned_Type (Source_Base_Type) | |
7108 | and then not Is_Unsigned_Type (Target_Base_Type) | |
7109 | then | |
7110 | -- If the source is unsigned and the target is signed, then we | |
7111 | -- know that the source is not shorter than the target (otherwise | |
7112 | -- the source base type would be in the target base type range). | |
7113 | ||
675d6070 TQ |
7114 | -- In other words, the unsigned type is either the same size as |
7115 | -- the target, or it is larger. It cannot be smaller. | |
fbf5a39b AC |
7116 | |
7117 | pragma Assert | |
7118 | (Esize (Source_Base_Type) >= Esize (Target_Base_Type)); | |
7119 | ||
7120 | -- We only need to check the low bound if the low bound of the | |
7121 | -- target type is non-negative. If the low bound of the target | |
7122 | -- type is negative, then we know that we will fit fine. | |
7123 | ||
7124 | -- If the high bound of the target type is negative, then we | |
7125 | -- know we have a constraint error, since we can't possibly | |
7126 | -- have a negative source. | |
7127 | ||
7128 | -- With these two checks out of the way, we can do the check | |
7129 | -- using the source type safely | |
7130 | ||
a90bd866 | 7131 | -- This is definitely the most annoying case. |
fbf5a39b AC |
7132 | |
7133 | -- [constraint_error | |
7134 | -- when (Target_Type'First >= 0 | |
7135 | -- and then | |
7136 | -- N < Source_Base_Type (Target_Type'First)) | |
7137 | -- or else Target_Type'Last < 0 | |
7138 | -- or else N > Source_Base_Type (Target_Type'Last)]; | |
7139 | ||
7140 | -- We turn off all checks since we know that the conversions | |
7141 | -- will work fine, given the guards for negative values. | |
7142 | ||
7143 | Insert_Action (N, | |
7144 | Make_Raise_Constraint_Error (Loc, | |
7145 | Condition => | |
7146 | Make_Or_Else (Loc, | |
7147 | Make_Or_Else (Loc, | |
7148 | Left_Opnd => | |
7149 | Make_And_Then (Loc, | |
7150 | Left_Opnd => Make_Op_Ge (Loc, | |
7151 | Left_Opnd => | |
7152 | Make_Attribute_Reference (Loc, | |
7153 | Prefix => | |
7154 | New_Occurrence_Of (Target_Type, Loc), | |
7155 | Attribute_Name => Name_First), | |
7156 | Right_Opnd => Make_Integer_Literal (Loc, Uint_0)), | |
7157 | ||
7158 | Right_Opnd => | |
7159 | Make_Op_Lt (Loc, | |
7160 | Left_Opnd => Duplicate_Subexpr (N), | |
7161 | Right_Opnd => | |
7162 | Convert_To (Source_Base_Type, | |
7163 | Make_Attribute_Reference (Loc, | |
7164 | Prefix => | |
7165 | New_Occurrence_Of (Target_Type, Loc), | |
7166 | Attribute_Name => Name_First)))), | |
7167 | ||
7168 | Right_Opnd => | |
7169 | Make_Op_Lt (Loc, | |
7170 | Left_Opnd => | |
7171 | Make_Attribute_Reference (Loc, | |
7172 | Prefix => New_Occurrence_Of (Target_Type, Loc), | |
7173 | Attribute_Name => Name_Last), | |
7174 | Right_Opnd => Make_Integer_Literal (Loc, Uint_0))), | |
7175 | ||
7176 | Right_Opnd => | |
7177 | Make_Op_Gt (Loc, | |
7178 | Left_Opnd => Duplicate_Subexpr (N), | |
7179 | Right_Opnd => | |
7180 | Convert_To (Source_Base_Type, | |
7181 | Make_Attribute_Reference (Loc, | |
7182 | Prefix => New_Occurrence_Of (Target_Type, Loc), | |
7183 | Attribute_Name => Name_Last)))), | |
7184 | ||
7185 | Reason => Reason), | |
7186 | Suppress => All_Checks); | |
7187 | ||
7188 | -- Only remaining possibility is that the source is signed and | |
b568955d | 7189 | -- the target is unsigned. |
fbf5a39b AC |
7190 | |
7191 | else | |
7192 | pragma Assert (not Is_Unsigned_Type (Source_Base_Type) | |
637a41a5 | 7193 | and then Is_Unsigned_Type (Target_Base_Type)); |
fbf5a39b | 7194 | |
675d6070 TQ |
7195 | -- If the source is signed and the target is unsigned, then we |
7196 | -- know that the target is not shorter than the source (otherwise | |
7197 | -- the target base type would be in the source base type range). | |
fbf5a39b | 7198 | |
675d6070 TQ |
7199 | -- In other words, the unsigned type is either the same size as |
7200 | -- the target, or it is larger. It cannot be smaller. | |
fbf5a39b | 7201 | |
675d6070 TQ |
7202 | -- Clearly we have an error if the source value is negative since |
7203 | -- no unsigned type can have negative values. If the source type | |
7204 | -- is non-negative, then the check can be done using the target | |
7205 | -- type. | |
fbf5a39b AC |
7206 | |
7207 | -- Tnn : constant Target_Base_Type (N) := Target_Type; | |
7208 | ||
7209 | -- [constraint_error | |
7210 | -- when N < 0 or else Tnn not in Target_Type]; | |
7211 | ||
675d6070 TQ |
7212 | -- We turn off all checks for the conversion of N to the target |
7213 | -- base type, since we generate the explicit check to ensure that | |
7214 | -- the value is non-negative | |
fbf5a39b AC |
7215 | |
7216 | declare | |
191fcb3a | 7217 | Tnn : constant Entity_Id := Make_Temporary (Loc, 'T', N); |
fbf5a39b AC |
7218 | |
7219 | begin | |
7220 | Insert_Actions (N, New_List ( | |
7221 | Make_Object_Declaration (Loc, | |
7222 | Defining_Identifier => Tnn, | |
7223 | Object_Definition => | |
7224 | New_Occurrence_Of (Target_Base_Type, Loc), | |
7225 | Constant_Present => True, | |
7226 | Expression => | |
d79e621a | 7227 | Make_Unchecked_Type_Conversion (Loc, |
fbf5a39b AC |
7228 | Subtype_Mark => |
7229 | New_Occurrence_Of (Target_Base_Type, Loc), | |
7230 | Expression => Duplicate_Subexpr (N))), | |
7231 | ||
7232 | Make_Raise_Constraint_Error (Loc, | |
7233 | Condition => | |
7234 | Make_Or_Else (Loc, | |
7235 | Left_Opnd => | |
7236 | Make_Op_Lt (Loc, | |
7237 | Left_Opnd => Duplicate_Subexpr (N), | |
7238 | Right_Opnd => Make_Integer_Literal (Loc, Uint_0)), | |
7239 | ||
7240 | Right_Opnd => | |
7241 | Make_Not_In (Loc, | |
7242 | Left_Opnd => New_Occurrence_Of (Tnn, Loc), | |
7243 | Right_Opnd => | |
7244 | New_Occurrence_Of (Target_Type, Loc))), | |
7245 | ||
637a41a5 | 7246 | Reason => Reason)), |
fbf5a39b AC |
7247 | Suppress => All_Checks); |
7248 | ||
675d6070 TQ |
7249 | -- Set the Etype explicitly, because Insert_Actions may have |
7250 | -- placed the declaration in the freeze list for an enclosing | |
7251 | -- construct, and thus it is not analyzed yet. | |
fbf5a39b AC |
7252 | |
7253 | Set_Etype (Tnn, Target_Base_Type); | |
7254 | Rewrite (N, New_Occurrence_Of (Tnn, Loc)); | |
7255 | end; | |
7256 | end if; | |
7257 | end if; | |
7258 | end Generate_Range_Check; | |
7259 | ||
939c12d2 RD |
7260 | ------------------ |
7261 | -- Get_Check_Id -- | |
7262 | ------------------ | |
7263 | ||
7264 | function Get_Check_Id (N : Name_Id) return Check_Id is | |
7265 | begin | |
7266 | -- For standard check name, we can do a direct computation | |
7267 | ||
7268 | if N in First_Check_Name .. Last_Check_Name then | |
7269 | return Check_Id (N - (First_Check_Name - 1)); | |
7270 | ||
7271 | -- For non-standard names added by pragma Check_Name, search table | |
7272 | ||
7273 | else | |
7274 | for J in All_Checks + 1 .. Check_Names.Last loop | |
7275 | if Check_Names.Table (J) = N then | |
7276 | return J; | |
7277 | end if; | |
7278 | end loop; | |
7279 | end if; | |
7280 | ||
7281 | -- No matching name found | |
7282 | ||
7283 | return No_Check_Id; | |
7284 | end Get_Check_Id; | |
7285 | ||
70482933 RK |
7286 | --------------------- |
7287 | -- Get_Discriminal -- | |
7288 | --------------------- | |
7289 | ||
7290 | function Get_Discriminal (E : Entity_Id; Bound : Node_Id) return Node_Id is | |
7291 | Loc : constant Source_Ptr := Sloc (E); | |
7292 | D : Entity_Id; | |
7293 | Sc : Entity_Id; | |
7294 | ||
7295 | begin | |
c064e066 RD |
7296 | -- The bound can be a bona fide parameter of a protected operation, |
7297 | -- rather than a prival encoded as an in-parameter. | |
7298 | ||
7299 | if No (Discriminal_Link (Entity (Bound))) then | |
7300 | return Bound; | |
7301 | end if; | |
7302 | ||
939c12d2 RD |
7303 | -- Climb the scope stack looking for an enclosing protected type. If |
7304 | -- we run out of scopes, return the bound itself. | |
7305 | ||
7306 | Sc := Scope (E); | |
7307 | while Present (Sc) loop | |
7308 | if Sc = Standard_Standard then | |
7309 | return Bound; | |
939c12d2 RD |
7310 | elsif Ekind (Sc) = E_Protected_Type then |
7311 | exit; | |
7312 | end if; | |
7313 | ||
7314 | Sc := Scope (Sc); | |
7315 | end loop; | |
7316 | ||
70482933 | 7317 | D := First_Discriminant (Sc); |
939c12d2 RD |
7318 | while Present (D) loop |
7319 | if Chars (D) = Chars (Bound) then | |
7320 | return New_Occurrence_Of (Discriminal (D), Loc); | |
7321 | end if; | |
70482933 | 7322 | |
70482933 RK |
7323 | Next_Discriminant (D); |
7324 | end loop; | |
7325 | ||
939c12d2 | 7326 | return Bound; |
70482933 RK |
7327 | end Get_Discriminal; |
7328 | ||
939c12d2 RD |
7329 | ---------------------- |
7330 | -- Get_Range_Checks -- | |
7331 | ---------------------- | |
7332 | ||
7333 | function Get_Range_Checks | |
7334 | (Ck_Node : Node_Id; | |
7335 | Target_Typ : Entity_Id; | |
7336 | Source_Typ : Entity_Id := Empty; | |
7337 | Warn_Node : Node_Id := Empty) return Check_Result | |
7338 | is | |
7339 | begin | |
637a41a5 AC |
7340 | return |
7341 | Selected_Range_Checks (Ck_Node, Target_Typ, Source_Typ, Warn_Node); | |
939c12d2 RD |
7342 | end Get_Range_Checks; |
7343 | ||
70482933 RK |
7344 | ------------------ |
7345 | -- Guard_Access -- | |
7346 | ------------------ | |
7347 | ||
7348 | function Guard_Access | |
7349 | (Cond : Node_Id; | |
7350 | Loc : Source_Ptr; | |
6b6fcd3e | 7351 | Ck_Node : Node_Id) return Node_Id |
70482933 RK |
7352 | is |
7353 | begin | |
7354 | if Nkind (Cond) = N_Or_Else then | |
7355 | Set_Paren_Count (Cond, 1); | |
7356 | end if; | |
7357 | ||
7358 | if Nkind (Ck_Node) = N_Allocator then | |
7359 | return Cond; | |
637a41a5 | 7360 | |
70482933 RK |
7361 | else |
7362 | return | |
7363 | Make_And_Then (Loc, | |
7364 | Left_Opnd => | |
7365 | Make_Op_Ne (Loc, | |
fbf5a39b | 7366 | Left_Opnd => Duplicate_Subexpr_No_Checks (Ck_Node), |
70482933 RK |
7367 | Right_Opnd => Make_Null (Loc)), |
7368 | Right_Opnd => Cond); | |
7369 | end if; | |
7370 | end Guard_Access; | |
7371 | ||
7372 | ----------------------------- | |
7373 | -- Index_Checks_Suppressed -- | |
7374 | ----------------------------- | |
7375 | ||
7376 | function Index_Checks_Suppressed (E : Entity_Id) return Boolean is | |
7377 | begin | |
fbf5a39b AC |
7378 | if Present (E) and then Checks_May_Be_Suppressed (E) then |
7379 | return Is_Check_Suppressed (E, Index_Check); | |
7380 | else | |
3217f71e | 7381 | return Scope_Suppress.Suppress (Index_Check); |
fbf5a39b | 7382 | end if; |
70482933 RK |
7383 | end Index_Checks_Suppressed; |
7384 | ||
7385 | ---------------- | |
7386 | -- Initialize -- | |
7387 | ---------------- | |
7388 | ||
7389 | procedure Initialize is | |
7390 | begin | |
7391 | for J in Determine_Range_Cache_N'Range loop | |
7392 | Determine_Range_Cache_N (J) := Empty; | |
7393 | end loop; | |
939c12d2 RD |
7394 | |
7395 | Check_Names.Init; | |
7396 | ||
7397 | for J in Int range 1 .. All_Checks loop | |
7398 | Check_Names.Append (Name_Id (Int (First_Check_Name) + J - 1)); | |
7399 | end loop; | |
70482933 RK |
7400 | end Initialize; |
7401 | ||
7402 | ------------------------- | |
7403 | -- Insert_Range_Checks -- | |
7404 | ------------------------- | |
7405 | ||
7406 | procedure Insert_Range_Checks | |
7407 | (Checks : Check_Result; | |
7408 | Node : Node_Id; | |
7409 | Suppress_Typ : Entity_Id; | |
7410 | Static_Sloc : Source_Ptr := No_Location; | |
7411 | Flag_Node : Node_Id := Empty; | |
7412 | Do_Before : Boolean := False) | |
7413 | is | |
e0666fc6 AC |
7414 | Checks_On : constant Boolean := |
7415 | not Index_Checks_Suppressed (Suppress_Typ) | |
7416 | or else | |
7417 | not Range_Checks_Suppressed (Suppress_Typ); | |
7418 | ||
7419 | Check_Node : Node_Id; | |
70482933 RK |
7420 | Internal_Flag_Node : Node_Id := Flag_Node; |
7421 | Internal_Static_Sloc : Source_Ptr := Static_Sloc; | |
7422 | ||
70482933 | 7423 | begin |
675d6070 TQ |
7424 | -- For now we just return if Checks_On is false, however this should be |
7425 | -- enhanced to check for an always True value in the condition and to | |
7426 | -- generate a compilation warning??? | |
70482933 | 7427 | |
1f0b1e48 | 7428 | if not Expander_Active or not Checks_On then |
70482933 RK |
7429 | return; |
7430 | end if; | |
7431 | ||
7432 | if Static_Sloc = No_Location then | |
7433 | Internal_Static_Sloc := Sloc (Node); | |
7434 | end if; | |
7435 | ||
7436 | if No (Flag_Node) then | |
7437 | Internal_Flag_Node := Node; | |
7438 | end if; | |
7439 | ||
7440 | for J in 1 .. 2 loop | |
7441 | exit when No (Checks (J)); | |
7442 | ||
7443 | if Nkind (Checks (J)) = N_Raise_Constraint_Error | |
7444 | and then Present (Condition (Checks (J))) | |
7445 | then | |
7446 | if not Has_Dynamic_Range_Check (Internal_Flag_Node) then | |
7447 | Check_Node := Checks (J); | |
7448 | Mark_Rewrite_Insertion (Check_Node); | |
7449 | ||
7450 | if Do_Before then | |
7451 | Insert_Before_And_Analyze (Node, Check_Node); | |
7452 | else | |
7453 | Insert_After_And_Analyze (Node, Check_Node); | |
7454 | end if; | |
7455 | ||
7456 | Set_Has_Dynamic_Range_Check (Internal_Flag_Node); | |
7457 | end if; | |
7458 | ||
7459 | else | |
7460 | Check_Node := | |
07fc65c4 GB |
7461 | Make_Raise_Constraint_Error (Internal_Static_Sloc, |
7462 | Reason => CE_Range_Check_Failed); | |
70482933 RK |
7463 | Mark_Rewrite_Insertion (Check_Node); |
7464 | ||
7465 | if Do_Before then | |
7466 | Insert_Before_And_Analyze (Node, Check_Node); | |
7467 | else | |
7468 | Insert_After_And_Analyze (Node, Check_Node); | |
7469 | end if; | |
7470 | end if; | |
7471 | end loop; | |
7472 | end Insert_Range_Checks; | |
7473 | ||
7474 | ------------------------ | |
7475 | -- Insert_Valid_Check -- | |
7476 | ------------------------ | |
7477 | ||
2934b84a AC |
7478 | procedure Insert_Valid_Check |
7479 | (Expr : Node_Id; | |
7480 | Related_Id : Entity_Id := Empty; | |
7481 | Is_Low_Bound : Boolean := False; | |
7482 | Is_High_Bound : Boolean := False) | |
7483 | is | |
70482933 | 7484 | Loc : constant Source_Ptr := Sloc (Expr); |
d515aef3 | 7485 | Typ : constant Entity_Id := Etype (Expr); |
84157f51 | 7486 | Exp : Node_Id; |
70482933 RK |
7487 | |
7488 | begin | |
2934b84a AC |
7489 | -- Do not insert if checks off, or if not checking validity or if |
7490 | -- expression is known to be valid. | |
70482933 | 7491 | |
c064e066 RD |
7492 | if not Validity_Checks_On |
7493 | or else Range_Or_Validity_Checks_Suppressed (Expr) | |
8dc2ddaf | 7494 | or else Expr_Known_Valid (Expr) |
70482933 | 7495 | then |
84157f51 | 7496 | return; |
70482933 | 7497 | |
489c6e19 AC |
7498 | -- Do not insert checks within a predicate function. This will arise |
7499 | -- if the current unit and the predicate function are being compiled | |
7500 | -- with validity checks enabled. | |
d515aef3 | 7501 | |
b0cd50fd | 7502 | elsif Present (Predicate_Function (Typ)) |
d515aef3 AC |
7503 | and then Current_Scope = Predicate_Function (Typ) |
7504 | then | |
7505 | return; | |
d515aef3 | 7506 | |
9dc30a5f AC |
7507 | -- If the expression is a packed component of a modular type of the |
7508 | -- right size, the data is always valid. | |
7509 | ||
b0cd50fd | 7510 | elsif Nkind (Expr) = N_Selected_Component |
9dc30a5f AC |
7511 | and then Present (Component_Clause (Entity (Selector_Name (Expr)))) |
7512 | and then Is_Modular_Integer_Type (Typ) | |
7513 | and then Modulus (Typ) = 2 ** Esize (Entity (Selector_Name (Expr))) | |
7514 | then | |
7515 | return; | |
b0cd50fd AC |
7516 | |
7517 | -- Do not generate a validity check when inside a generic unit as this | |
7518 | -- is an expansion activity. | |
7519 | ||
7520 | elsif Inside_A_Generic then | |
7521 | return; | |
9dc30a5f AC |
7522 | end if; |
7523 | ||
6578a6bf HK |
7524 | -- Entities declared in Lock_free protected types must be treated as |
7525 | -- volatile, and we must inhibit validity checks to prevent improper | |
7526 | -- constant folding. | |
90fd73bb ES |
7527 | |
7528 | if Is_Entity_Name (Expr) | |
7529 | and then Is_Subprogram (Scope (Entity (Expr))) | |
7530 | and then Present (Protected_Subprogram (Scope (Entity (Expr)))) | |
7531 | and then Uses_Lock_Free | |
6578a6bf | 7532 | (Scope (Protected_Subprogram (Scope (Entity (Expr))))) |
90fd73bb ES |
7533 | then |
7534 | return; | |
7535 | end if; | |
7536 | ||
84157f51 GB |
7537 | -- If we have a checked conversion, then validity check applies to |
7538 | -- the expression inside the conversion, not the result, since if | |
7539 | -- the expression inside is valid, then so is the conversion result. | |
70482933 | 7540 | |
84157f51 GB |
7541 | Exp := Expr; |
7542 | while Nkind (Exp) = N_Type_Conversion loop | |
7543 | Exp := Expression (Exp); | |
7544 | end loop; | |
7545 | ||
89b6c83e AC |
7546 | -- Do not generate a check for a variable which already validates the |
7547 | -- value of an assignable object. | |
7548 | ||
7549 | if Is_Validation_Variable_Reference (Exp) then | |
7550 | return; | |
7551 | end if; | |
7552 | ||
c064e066 | 7553 | declare |
62e45e3e | 7554 | CE : Node_Id; |
62e45e3e HK |
7555 | PV : Node_Id; |
7556 | Var_Id : Entity_Id; | |
d8b9660d | 7557 | |
c064e066 | 7558 | begin |
89b6c83e AC |
7559 | -- If the expression denotes an assignable object, capture its value |
7560 | -- in a variable and replace the original expression by the variable. | |
7561 | -- This approach has several effects: | |
8dc2ddaf | 7562 | |
89b6c83e AC |
7563 | -- 1) The evaluation of the object results in only one read in the |
7564 | -- case where the object is atomic or volatile. | |
59f4d038 | 7565 | |
62e45e3e | 7566 | -- Var ... := Object; -- read |
59f4d038 | 7567 | |
89b6c83e AC |
7568 | -- 2) The captured value is the one verified by attribute 'Valid. |
7569 | -- As a result the object is not evaluated again, which would | |
7570 | -- result in an unwanted read in the case where the object is | |
7571 | -- atomic or volatile. | |
7572 | ||
62e45e3e | 7573 | -- if not Var'Valid then -- OK, no read of Object |
89b6c83e AC |
7574 | |
7575 | -- if not Object'Valid then -- Wrong, extra read of Object | |
7576 | ||
7577 | -- 3) The captured value replaces the original object reference. | |
7578 | -- As a result the object is not evaluated again, in the same | |
7579 | -- vein as 2). | |
7580 | ||
62e45e3e | 7581 | -- ... Var ... -- OK, no read of Object |
89b6c83e AC |
7582 | |
7583 | -- ... Object ... -- Wrong, extra read of Object | |
8dc2ddaf | 7584 | |
89b6c83e AC |
7585 | -- 4) The use of a variable to capture the value of the object |
7586 | -- allows the propagation of any changes back to the original | |
7587 | -- object. | |
7588 | ||
7589 | -- procedure Call (Val : in out ...); | |
7590 | ||
62e45e3e HK |
7591 | -- Var : ... := Object; -- read Object |
7592 | -- if not Var'Valid then -- validity check | |
7593 | -- Call (Var); -- modify Var | |
7594 | -- Object := Var; -- update Object | |
89b6c83e AC |
7595 | |
7596 | if Is_Variable (Exp) then | |
62e45e3e | 7597 | Var_Id := Make_Temporary (Loc, 'T', Exp); |
89b6c83e | 7598 | |
683af98c AC |
7599 | -- Because we could be dealing with a transient scope which would |
7600 | -- cause our object declaration to remain unanalyzed we must do | |
7601 | -- some manual decoration. | |
7602 | ||
7603 | Set_Ekind (Var_Id, E_Variable); | |
7604 | Set_Etype (Var_Id, Typ); | |
7605 | ||
89b6c83e AC |
7606 | Insert_Action (Exp, |
7607 | Make_Object_Declaration (Loc, | |
62e45e3e | 7608 | Defining_Identifier => Var_Id, |
89b6c83e | 7609 | Object_Definition => New_Occurrence_Of (Typ, Loc), |
dd89dddf AC |
7610 | Expression => New_Copy_Tree (Exp)), |
7611 | Suppress => Validity_Check); | |
7612 | ||
7613 | Set_Validated_Object (Var_Id, New_Copy_Tree (Exp)); | |
13931a38 | 7614 | |
62e45e3e | 7615 | Rewrite (Exp, New_Occurrence_Of (Var_Id, Loc)); |
89b6c83e | 7616 | |
1361a4fb EB |
7617 | -- Move the Do_Range_Check flag over to the new Exp so it doesn't |
7618 | -- get lost and doesn't leak elsewhere. | |
3815f967 | 7619 | |
1361a4fb EB |
7620 | if Do_Range_Check (Validated_Object (Var_Id)) then |
7621 | Set_Do_Range_Check (Exp); | |
7622 | Set_Do_Range_Check (Validated_Object (Var_Id), False); | |
3815f967 AC |
7623 | end if; |
7624 | ||
13931a38 EB |
7625 | PV := New_Occurrence_Of (Var_Id, Loc); |
7626 | ||
89b6c83e AC |
7627 | -- Otherwise the expression does not denote a variable. Force its |
7628 | -- evaluation by capturing its value in a constant. Generate: | |
7629 | ||
7630 | -- Temp : constant ... := Exp; | |
7631 | ||
7632 | else | |
7633 | Force_Evaluation | |
7634 | (Exp => Exp, | |
7635 | Related_Id => Related_Id, | |
7636 | Is_Low_Bound => Is_Low_Bound, | |
7637 | Is_High_Bound => Is_High_Bound); | |
7638 | ||
7639 | PV := New_Copy_Tree (Exp); | |
7640 | end if; | |
c064e066 | 7641 | |
e80f0cb0 RD |
7642 | -- A rather specialized test. If PV is an analyzed expression which |
7643 | -- is an indexed component of a packed array that has not been | |
7644 | -- properly expanded, turn off its Analyzed flag to make sure it | |
4bd4bb7f AC |
7645 | -- gets properly reexpanded. If the prefix is an access value, |
7646 | -- the dereference will be added later. | |
0e564ab4 AC |
7647 | |
7648 | -- The reason this arises is that Duplicate_Subexpr_No_Checks did | |
7649 | -- an analyze with the old parent pointer. This may point e.g. to | |
7650 | -- a subprogram call, which deactivates this expansion. | |
7651 | ||
7652 | if Analyzed (PV) | |
7653 | and then Nkind (PV) = N_Indexed_Component | |
4bd4bb7f | 7654 | and then Is_Array_Type (Etype (Prefix (PV))) |
8ca597af | 7655 | and then Present (Packed_Array_Impl_Type (Etype (Prefix (PV)))) |
0e564ab4 AC |
7656 | then |
7657 | Set_Analyzed (PV, False); | |
7658 | end if; | |
7659 | ||
59f4d038 RD |
7660 | -- Build the raise CE node to check for validity. We build a type |
7661 | -- qualification for the prefix, since it may not be of the form of | |
7662 | -- a name, and we don't care in this context! | |
0e564ab4 AC |
7663 | |
7664 | CE := | |
2934b84a AC |
7665 | Make_Raise_Constraint_Error (Loc, |
7666 | Condition => | |
7667 | Make_Op_Not (Loc, | |
7668 | Right_Opnd => | |
7669 | Make_Attribute_Reference (Loc, | |
7670 | Prefix => PV, | |
7671 | Attribute_Name => Name_Valid)), | |
7672 | Reason => CE_Invalid_Data); | |
0e564ab4 AC |
7673 | |
7674 | -- Insert the validity check. Note that we do this with validity | |
7675 | -- checks turned off, to avoid recursion, we do not want validity | |
a90bd866 | 7676 | -- checks on the validity checking code itself. |
0e564ab4 AC |
7677 | |
7678 | Insert_Action (Expr, CE, Suppress => Validity_Check); | |
c064e066 | 7679 | |
308e6f3a | 7680 | -- If the expression is a reference to an element of a bit-packed |
c064e066 RD |
7681 | -- array, then it is rewritten as a renaming declaration. If the |
7682 | -- expression is an actual in a call, it has not been expanded, | |
7683 | -- waiting for the proper point at which to do it. The same happens | |
7684 | -- with renamings, so that we have to force the expansion now. This | |
7685 | -- non-local complication is due to code in exp_ch2,adb, exp_ch4.adb | |
7686 | -- and exp_ch6.adb. | |
7687 | ||
7688 | if Is_Entity_Name (Exp) | |
7689 | and then Nkind (Parent (Entity (Exp))) = | |
637a41a5 | 7690 | N_Object_Renaming_Declaration |
c064e066 RD |
7691 | then |
7692 | declare | |
7693 | Old_Exp : constant Node_Id := Name (Parent (Entity (Exp))); | |
7694 | begin | |
7695 | if Nkind (Old_Exp) = N_Indexed_Component | |
7696 | and then Is_Bit_Packed_Array (Etype (Prefix (Old_Exp))) | |
7697 | then | |
7698 | Expand_Packed_Element_Reference (Old_Exp); | |
7699 | end if; | |
7700 | end; | |
7701 | end if; | |
c064e066 | 7702 | end; |
70482933 RK |
7703 | end Insert_Valid_Check; |
7704 | ||
acad3c0a AC |
7705 | ------------------------------------- |
7706 | -- Is_Signed_Integer_Arithmetic_Op -- | |
7707 | ------------------------------------- | |
7708 | ||
7709 | function Is_Signed_Integer_Arithmetic_Op (N : Node_Id) return Boolean is | |
7710 | begin | |
7711 | case Nkind (N) is | |
d8f43ee6 HK |
7712 | when N_Op_Abs |
7713 | | N_Op_Add | |
7714 | | N_Op_Divide | |
7715 | | N_Op_Expon | |
7716 | | N_Op_Minus | |
7717 | | N_Op_Mod | |
7718 | | N_Op_Multiply | |
7719 | | N_Op_Plus | |
7720 | | N_Op_Rem | |
7721 | | N_Op_Subtract | |
7722 | => | |
acad3c0a AC |
7723 | return Is_Signed_Integer_Type (Etype (N)); |
7724 | ||
d8f43ee6 HK |
7725 | when N_Case_Expression |
7726 | | N_If_Expression | |
7727 | => | |
4b1c4f20 RD |
7728 | return Is_Signed_Integer_Type (Etype (N)); |
7729 | ||
acad3c0a AC |
7730 | when others => |
7731 | return False; | |
7732 | end case; | |
7733 | end Is_Signed_Integer_Arithmetic_Op; | |
7734 | ||
2820d220 AC |
7735 | ---------------------------------- |
7736 | -- Install_Null_Excluding_Check -- | |
7737 | ---------------------------------- | |
7738 | ||
7739 | procedure Install_Null_Excluding_Check (N : Node_Id) is | |
437f8c1e | 7740 | Loc : constant Source_Ptr := Sloc (Parent (N)); |
86ac5e79 ES |
7741 | Typ : constant Entity_Id := Etype (N); |
7742 | ||
ac7120ce RD |
7743 | function Safe_To_Capture_In_Parameter_Value return Boolean; |
7744 | -- Determines if it is safe to capture Known_Non_Null status for an | |
7745 | -- the entity referenced by node N. The caller ensures that N is indeed | |
7746 | -- an entity name. It is safe to capture the non-null status for an IN | |
7747 | -- parameter when the reference occurs within a declaration that is sure | |
7748 | -- to be executed as part of the declarative region. | |
bb6e3d41 | 7749 | |
86ac5e79 | 7750 | procedure Mark_Non_Null; |
bb6e3d41 HK |
7751 | -- After installation of check, if the node in question is an entity |
7752 | -- name, then mark this entity as non-null if possible. | |
7753 | ||
ac7120ce | 7754 | function Safe_To_Capture_In_Parameter_Value return Boolean is |
bb6e3d41 HK |
7755 | E : constant Entity_Id := Entity (N); |
7756 | S : constant Entity_Id := Current_Scope; | |
7757 | S_Par : Node_Id; | |
7758 | ||
7759 | begin | |
ac7120ce RD |
7760 | if Ekind (E) /= E_In_Parameter then |
7761 | return False; | |
7762 | end if; | |
bb6e3d41 HK |
7763 | |
7764 | -- Two initial context checks. We must be inside a subprogram body | |
7765 | -- with declarations and reference must not appear in nested scopes. | |
7766 | ||
ac7120ce | 7767 | if (Ekind (S) /= E_Function and then Ekind (S) /= E_Procedure) |
bb6e3d41 HK |
7768 | or else Scope (E) /= S |
7769 | then | |
7770 | return False; | |
7771 | end if; | |
7772 | ||
7773 | S_Par := Parent (Parent (S)); | |
7774 | ||
7775 | if Nkind (S_Par) /= N_Subprogram_Body | |
7776 | or else No (Declarations (S_Par)) | |
7777 | then | |
7778 | return False; | |
7779 | end if; | |
7780 | ||
7781 | declare | |
7782 | N_Decl : Node_Id; | |
7783 | P : Node_Id; | |
7784 | ||
7785 | begin | |
7786 | -- Retrieve the declaration node of N (if any). Note that N | |
7787 | -- may be a part of a complex initialization expression. | |
7788 | ||
7789 | P := Parent (N); | |
7790 | N_Decl := Empty; | |
7791 | while Present (P) loop | |
7792 | ||
ac7120ce RD |
7793 | -- If we have a short circuit form, and we are within the right |
7794 | -- hand expression, we return false, since the right hand side | |
7795 | -- is not guaranteed to be elaborated. | |
7796 | ||
7797 | if Nkind (P) in N_Short_Circuit | |
7798 | and then N = Right_Opnd (P) | |
7799 | then | |
7800 | return False; | |
7801 | end if; | |
7802 | ||
9b16cb57 RD |
7803 | -- Similarly, if we are in an if expression and not part of the |
7804 | -- condition, then we return False, since neither the THEN or | |
7805 | -- ELSE dependent expressions will always be elaborated. | |
ac7120ce | 7806 | |
9b16cb57 | 7807 | if Nkind (P) = N_If_Expression |
ac7120ce RD |
7808 | and then N /= First (Expressions (P)) |
7809 | then | |
7810 | return False; | |
19d846a0 RD |
7811 | end if; |
7812 | ||
637a41a5 AC |
7813 | -- If within a case expression, and not part of the expression, |
7814 | -- then return False, since a particular dependent expression | |
7815 | -- may not always be elaborated | |
19d846a0 RD |
7816 | |
7817 | if Nkind (P) = N_Case_Expression | |
7818 | and then N /= Expression (P) | |
7819 | then | |
7820 | return False; | |
ac7120ce RD |
7821 | end if; |
7822 | ||
637a41a5 AC |
7823 | -- While traversing the parent chain, if node N belongs to a |
7824 | -- statement, then it may never appear in a declarative region. | |
bb6e3d41 HK |
7825 | |
7826 | if Nkind (P) in N_Statement_Other_Than_Procedure_Call | |
7827 | or else Nkind (P) = N_Procedure_Call_Statement | |
7828 | then | |
7829 | return False; | |
7830 | end if; | |
7831 | ||
ac7120ce RD |
7832 | -- If we are at a declaration, record it and exit |
7833 | ||
bb6e3d41 HK |
7834 | if Nkind (P) in N_Declaration |
7835 | and then Nkind (P) not in N_Subprogram_Specification | |
7836 | then | |
7837 | N_Decl := P; | |
7838 | exit; | |
7839 | end if; | |
7840 | ||
7841 | P := Parent (P); | |
7842 | end loop; | |
7843 | ||
7844 | if No (N_Decl) then | |
7845 | return False; | |
7846 | end if; | |
7847 | ||
7848 | return List_Containing (N_Decl) = Declarations (S_Par); | |
7849 | end; | |
ac7120ce | 7850 | end Safe_To_Capture_In_Parameter_Value; |
86ac5e79 ES |
7851 | |
7852 | ------------------- | |
7853 | -- Mark_Non_Null -- | |
7854 | ------------------- | |
7855 | ||
7856 | procedure Mark_Non_Null is | |
7857 | begin | |
bb6e3d41 HK |
7858 | -- Only case of interest is if node N is an entity name |
7859 | ||
86ac5e79 | 7860 | if Is_Entity_Name (N) then |
bb6e3d41 HK |
7861 | |
7862 | -- For sure, we want to clear an indication that this is known to | |
a90bd866 | 7863 | -- be null, since if we get past this check, it definitely is not. |
bb6e3d41 | 7864 | |
86ac5e79 ES |
7865 | Set_Is_Known_Null (Entity (N), False); |
7866 | ||
bb6e3d41 HK |
7867 | -- We can mark the entity as known to be non-null if either it is |
7868 | -- safe to capture the value, or in the case of an IN parameter, | |
7869 | -- which is a constant, if the check we just installed is in the | |
7870 | -- declarative region of the subprogram body. In this latter case, | |
ac7120ce RD |
7871 | -- a check is decisive for the rest of the body if the expression |
7872 | -- is sure to be elaborated, since we know we have to elaborate | |
7873 | -- all declarations before executing the body. | |
7874 | ||
7875 | -- Couldn't this always be part of Safe_To_Capture_Value ??? | |
bb6e3d41 HK |
7876 | |
7877 | if Safe_To_Capture_Value (N, Entity (N)) | |
ac7120ce | 7878 | or else Safe_To_Capture_In_Parameter_Value |
bb6e3d41 HK |
7879 | then |
7880 | Set_Is_Known_Non_Null (Entity (N)); | |
86ac5e79 ES |
7881 | end if; |
7882 | end if; | |
7883 | end Mark_Non_Null; | |
7884 | ||
7885 | -- Start of processing for Install_Null_Excluding_Check | |
2820d220 AC |
7886 | |
7887 | begin | |
fcf1dd74 JM |
7888 | -- No need to add null-excluding checks when the tree may not be fully |
7889 | -- decorated. | |
7890 | ||
7891 | if Serious_Errors_Detected > 0 then | |
7892 | return; | |
7893 | end if; | |
7894 | ||
86ac5e79 | 7895 | pragma Assert (Is_Access_Type (Typ)); |
2820d220 | 7896 | |
cca7f107 | 7897 | -- No check inside a generic, check will be emitted in instance |
2820d220 | 7898 | |
86ac5e79 | 7899 | if Inside_A_Generic then |
2820d220 | 7900 | return; |
86ac5e79 ES |
7901 | end if; |
7902 | ||
7903 | -- No check needed if known to be non-null | |
7904 | ||
7905 | if Known_Non_Null (N) then | |
d8b9660d | 7906 | return; |
86ac5e79 | 7907 | end if; |
2820d220 | 7908 | |
86ac5e79 ES |
7909 | -- If known to be null, here is where we generate a compile time check |
7910 | ||
7911 | if Known_Null (N) then | |
b1c11e0e | 7912 | |
637a41a5 AC |
7913 | -- Avoid generating warning message inside init procs. In SPARK mode |
7914 | -- we can go ahead and call Apply_Compile_Time_Constraint_Error | |
cca7f107 | 7915 | -- since it will be turned into an error in any case. |
b1c11e0e | 7916 | |
cca7f107 AC |
7917 | if (not Inside_Init_Proc or else SPARK_Mode = On) |
7918 | ||
1ae70618 ES |
7919 | -- Do not emit the warning within a conditional expression, |
7920 | -- where the expression might not be evaluated, and the warning | |
7921 | -- appear as extraneous noise. | |
cca7f107 AC |
7922 | |
7923 | and then not Within_Case_Or_If_Expression (N) | |
7924 | then | |
b1c11e0e | 7925 | Apply_Compile_Time_Constraint_Error |
4a28b181 | 7926 | (N, "null value not allowed here??", CE_Access_Check_Failed); |
cca7f107 AC |
7927 | |
7928 | -- Remaining cases, where we silently insert the raise | |
7929 | ||
b1c11e0e JM |
7930 | else |
7931 | Insert_Action (N, | |
7932 | Make_Raise_Constraint_Error (Loc, | |
7933 | Reason => CE_Access_Check_Failed)); | |
7934 | end if; | |
7935 | ||
86ac5e79 ES |
7936 | Mark_Non_Null; |
7937 | return; | |
7938 | end if; | |
7939 | ||
7940 | -- If entity is never assigned, for sure a warning is appropriate | |
7941 | ||
7942 | if Is_Entity_Name (N) then | |
7943 | Check_Unset_Reference (N); | |
2820d220 | 7944 | end if; |
86ac5e79 ES |
7945 | |
7946 | -- No check needed if checks are suppressed on the range. Note that we | |
7947 | -- don't set Is_Known_Non_Null in this case (we could legitimately do | |
7948 | -- so, since the program is erroneous, but we don't like to casually | |
7949 | -- propagate such conclusions from erroneosity). | |
7950 | ||
7951 | if Access_Checks_Suppressed (Typ) then | |
7952 | return; | |
7953 | end if; | |
7954 | ||
939c12d2 RD |
7955 | -- No check needed for access to concurrent record types generated by |
7956 | -- the expander. This is not just an optimization (though it does indeed | |
7957 | -- remove junk checks). It also avoids generation of junk warnings. | |
7958 | ||
7959 | if Nkind (N) in N_Has_Chars | |
7960 | and then Chars (N) = Name_uObject | |
7961 | and then Is_Concurrent_Record_Type | |
7962 | (Directly_Designated_Type (Etype (N))) | |
7963 | then | |
7964 | return; | |
7965 | end if; | |
7966 | ||
0a376301 JM |
7967 | -- No check needed in interface thunks since the runtime check is |
7968 | -- already performed at the caller side. | |
7969 | ||
7970 | if Is_Thunk (Current_Scope) then | |
7971 | return; | |
7972 | end if; | |
7973 | ||
74cab21a EB |
7974 | -- No check needed for the Get_Current_Excep.all.all idiom generated by |
7975 | -- the expander within exception handlers, since we know that the value | |
7976 | -- can never be null. | |
7977 | ||
7978 | -- Is this really the right way to do this? Normally we generate such | |
7979 | -- code in the expander with checks off, and that's how we suppress this | |
7980 | -- kind of junk check ??? | |
7981 | ||
7982 | if Nkind (N) = N_Function_Call | |
7983 | and then Nkind (Name (N)) = N_Explicit_Dereference | |
7984 | and then Nkind (Prefix (Name (N))) = N_Identifier | |
7985 | and then Is_RTE (Entity (Prefix (Name (N))), RE_Get_Current_Excep) | |
7986 | then | |
5c34f30d YM |
7987 | return; |
7988 | end if; | |
7989 | ||
7990 | -- In GNATprove mode, we do not apply the check | |
7991 | ||
7992 | if GNATprove_Mode then | |
74cab21a EB |
7993 | return; |
7994 | end if; | |
7995 | ||
86ac5e79 ES |
7996 | -- Otherwise install access check |
7997 | ||
7998 | Insert_Action (N, | |
7999 | Make_Raise_Constraint_Error (Loc, | |
8000 | Condition => | |
8001 | Make_Op_Eq (Loc, | |
8002 | Left_Opnd => Duplicate_Subexpr_Move_Checks (N), | |
8003 | Right_Opnd => Make_Null (Loc)), | |
8004 | Reason => CE_Access_Check_Failed)); | |
8005 | ||
8006 | Mark_Non_Null; | |
2820d220 AC |
8007 | end Install_Null_Excluding_Check; |
8008 | ||
7327f5c2 AC |
8009 | ----------------------------------------- |
8010 | -- Install_Primitive_Elaboration_Check -- | |
8011 | ----------------------------------------- | |
8012 | ||
8013 | procedure Install_Primitive_Elaboration_Check (Subp_Body : Node_Id) is | |
7327f5c2 AC |
8014 | function Within_Compilation_Unit_Instance |
8015 | (Subp_Id : Entity_Id) return Boolean; | |
8016 | -- Determine whether subprogram Subp_Id appears within an instance which | |
8017 | -- acts as a compilation unit. | |
8018 | ||
8019 | -------------------------------------- | |
8020 | -- Within_Compilation_Unit_Instance -- | |
8021 | -------------------------------------- | |
8022 | ||
8023 | function Within_Compilation_Unit_Instance | |
8024 | (Subp_Id : Entity_Id) return Boolean | |
8025 | is | |
8026 | Pack : Entity_Id; | |
8027 | ||
8028 | begin | |
8029 | -- Examine the scope chain looking for a compilation-unit-level | |
8030 | -- instance. | |
8031 | ||
8032 | Pack := Scope (Subp_Id); | |
8033 | while Present (Pack) and then Pack /= Standard_Standard loop | |
8034 | if Ekind (Pack) = E_Package | |
8035 | and then Is_Generic_Instance (Pack) | |
8036 | and then Nkind (Parent (Unit_Declaration_Node (Pack))) = | |
8037 | N_Compilation_Unit | |
8038 | then | |
8039 | return True; | |
8040 | end if; | |
8041 | ||
8042 | Pack := Scope (Pack); | |
8043 | end loop; | |
8044 | ||
8045 | return False; | |
8046 | end Within_Compilation_Unit_Instance; | |
8047 | ||
8048 | -- Local declarations | |
8049 | ||
8050 | Context : constant Node_Id := Parent (Subp_Body); | |
8051 | Loc : constant Source_Ptr := Sloc (Subp_Body); | |
8052 | Subp_Id : constant Entity_Id := Unique_Defining_Entity (Subp_Body); | |
8053 | Subp_Decl : constant Node_Id := Unit_Declaration_Node (Subp_Id); | |
8054 | ||
8dce7371 PMR |
8055 | Decls : List_Id; |
8056 | Flag_Id : Entity_Id; | |
8057 | Set_Ins : Node_Id; | |
8058 | Set_Stmt : Node_Id; | |
8059 | Tag_Typ : Entity_Id; | |
7327f5c2 AC |
8060 | |
8061 | -- Start of processing for Install_Primitive_Elaboration_Check | |
8062 | ||
8063 | begin | |
8064 | -- Do not generate an elaboration check in compilation modes where | |
8065 | -- expansion is not desirable. | |
8066 | ||
8067 | if ASIS_Mode or GNATprove_Mode then | |
8068 | return; | |
8069 | ||
85be939e AC |
8070 | -- Do not generate an elaboration check if all checks have been |
8071 | -- suppressed. | |
304757d2 | 8072 | |
85be939e | 8073 | elsif Suppress_Checks then |
304757d2 AC |
8074 | return; |
8075 | ||
7327f5c2 AC |
8076 | -- Do not generate an elaboration check if the related subprogram is |
8077 | -- not subjected to accessibility checks. | |
8078 | ||
8079 | elsif Elaboration_Checks_Suppressed (Subp_Id) then | |
8080 | return; | |
85be939e AC |
8081 | |
8082 | -- Do not generate an elaboration check if such code is not desirable | |
8083 | ||
8084 | elsif Restriction_Active (No_Elaboration_Code) then | |
8085 | return; | |
7327f5c2 | 8086 | |
640ad9c2 HK |
8087 | -- Do not generate an elaboration check if exceptions cannot be used, |
8088 | -- caught, or propagated. | |
8089 | ||
8090 | elsif not Exceptions_OK then | |
8091 | return; | |
8092 | ||
7327f5c2 AC |
8093 | -- Do not consider subprograms which act as compilation units, because |
8094 | -- they cannot be the target of a dispatching call. | |
8095 | ||
8096 | elsif Nkind (Context) = N_Compilation_Unit then | |
8097 | return; | |
8098 | ||
8dce7371 PMR |
8099 | -- Do not consider anything other than nonabstract library-level source |
8100 | -- primitives. | |
7327f5c2 AC |
8101 | |
8102 | elsif not | |
8103 | (Comes_From_Source (Subp_Id) | |
8104 | and then Is_Library_Level_Entity (Subp_Id) | |
8105 | and then Is_Primitive (Subp_Id) | |
8106 | and then not Is_Abstract_Subprogram (Subp_Id)) | |
8107 | then | |
8108 | return; | |
8109 | ||
8110 | -- Do not consider inlined primitives, because once the body is inlined | |
8111 | -- the reference to the elaboration flag will be out of place and will | |
8112 | -- result in an undefined symbol. | |
8113 | ||
8114 | elsif Is_Inlined (Subp_Id) or else Has_Pragma_Inline (Subp_Id) then | |
8115 | return; | |
8116 | ||
8117 | -- Do not generate a duplicate elaboration check. This happens only in | |
8118 | -- the case of primitives completed by an expression function, as the | |
8119 | -- corresponding body is apparently analyzed and expanded twice. | |
8120 | ||
8121 | elsif Analyzed (Subp_Body) then | |
8122 | return; | |
8123 | ||
8124 | -- Do not consider primitives which occur within an instance that acts | |
8125 | -- as a compilation unit. Such an instance defines its spec and body out | |
8126 | -- of order (body is first) within the tree, which causes the reference | |
8127 | -- to the elaboration flag to appear as an undefined symbol. | |
8128 | ||
8129 | elsif Within_Compilation_Unit_Instance (Subp_Id) then | |
8130 | return; | |
8131 | end if; | |
8132 | ||
8133 | Tag_Typ := Find_Dispatching_Type (Subp_Id); | |
8134 | ||
8135 | -- Only tagged primitives may be the target of a dispatching call | |
8136 | ||
8137 | if No (Tag_Typ) then | |
8138 | return; | |
8139 | ||
8140 | -- Do not consider finalization-related primitives, because they may | |
8141 | -- need to be called while elaboration is taking place. | |
8142 | ||
8143 | elsif Is_Controlled (Tag_Typ) | |
8144 | and then Nam_In (Chars (Subp_Id), Name_Adjust, | |
8145 | Name_Finalize, | |
8146 | Name_Initialize) | |
8147 | then | |
8148 | return; | |
8149 | end if; | |
8150 | ||
8151 | -- Create the declaration of the elaboration flag. The name carries a | |
8152 | -- unique counter in case of name overloading. | |
8153 | ||
8154 | Flag_Id := | |
8155 | Make_Defining_Identifier (Loc, | |
90e491a7 | 8156 | Chars => New_External_Name (Chars (Subp_Id), 'E', -1)); |
7327f5c2 AC |
8157 | Set_Is_Frozen (Flag_Id); |
8158 | ||
8159 | -- Insert the declaration of the elaboration flag in front of the | |
8160 | -- primitive spec and analyze it in the proper context. | |
8161 | ||
8162 | Push_Scope (Scope (Subp_Id)); | |
8163 | ||
8164 | -- Generate: | |
90e491a7 | 8165 | -- E : Boolean := False; |
7327f5c2 AC |
8166 | |
8167 | Insert_Action (Subp_Decl, | |
8168 | Make_Object_Declaration (Loc, | |
8169 | Defining_Identifier => Flag_Id, | |
8170 | Object_Definition => New_Occurrence_Of (Standard_Boolean, Loc), | |
8171 | Expression => New_Occurrence_Of (Standard_False, Loc))); | |
8172 | Pop_Scope; | |
8173 | ||
8174 | -- Prevent the compiler from optimizing the elaboration check by killing | |
8175 | -- the current value of the flag and the associated assignment. | |
8176 | ||
8177 | Set_Current_Value (Flag_Id, Empty); | |
8178 | Set_Last_Assignment (Flag_Id, Empty); | |
8179 | ||
8180 | -- Add a check at the top of the body declarations to ensure that the | |
8181 | -- elaboration flag has been set. | |
8182 | ||
8183 | Decls := Declarations (Subp_Body); | |
8184 | ||
8185 | if No (Decls) then | |
8186 | Decls := New_List; | |
8187 | Set_Declarations (Subp_Body, Decls); | |
8188 | end if; | |
8189 | ||
8190 | -- Generate: | |
8191 | -- if not F then | |
8192 | -- raise Program_Error with "access before elaboration"; | |
8193 | -- end if; | |
8194 | ||
8195 | Prepend_To (Decls, | |
8196 | Make_Raise_Program_Error (Loc, | |
8197 | Condition => | |
8198 | Make_Op_Not (Loc, | |
8199 | Right_Opnd => New_Occurrence_Of (Flag_Id, Loc)), | |
8200 | Reason => PE_Access_Before_Elaboration)); | |
8201 | ||
8202 | Analyze (First (Decls)); | |
8203 | ||
8204 | -- Set the elaboration flag once the body has been elaborated. Insert | |
8205 | -- the statement after the subprogram stub when the primitive body is | |
8206 | -- a subunit. | |
8207 | ||
8208 | if Nkind (Context) = N_Subunit then | |
8209 | Set_Ins := Corresponding_Stub (Context); | |
8210 | else | |
8211 | Set_Ins := Subp_Body; | |
8212 | end if; | |
8213 | ||
8214 | -- Generate: | |
90e491a7 | 8215 | -- E := True; |
7327f5c2 | 8216 | |
8dce7371 | 8217 | Set_Stmt := |
7327f5c2 AC |
8218 | Make_Assignment_Statement (Loc, |
8219 | Name => New_Occurrence_Of (Flag_Id, Loc), | |
8dce7371 PMR |
8220 | Expression => New_Occurrence_Of (Standard_True, Loc)); |
8221 | ||
8222 | -- Mark the assignment statement as elaboration code. This allows the | |
8223 | -- early call region mechanism (see Sem_Elab) to properly ignore such | |
8224 | -- assignments even though they are non-preelaborable code. | |
8225 | ||
8226 | Set_Is_Elaboration_Code (Set_Stmt); | |
8227 | ||
8228 | Insert_After_And_Analyze (Set_Ins, Set_Stmt); | |
7327f5c2 AC |
8229 | end Install_Primitive_Elaboration_Check; |
8230 | ||
70482933 RK |
8231 | -------------------------- |
8232 | -- Install_Static_Check -- | |
8233 | -------------------------- | |
8234 | ||
8235 | procedure Install_Static_Check (R_Cno : Node_Id; Loc : Source_Ptr) is | |
edab6088 | 8236 | Stat : constant Boolean := Is_OK_Static_Expression (R_Cno); |
70482933 RK |
8237 | Typ : constant Entity_Id := Etype (R_Cno); |
8238 | ||
8239 | begin | |
07fc65c4 GB |
8240 | Rewrite (R_Cno, |
8241 | Make_Raise_Constraint_Error (Loc, | |
8242 | Reason => CE_Range_Check_Failed)); | |
70482933 RK |
8243 | Set_Analyzed (R_Cno); |
8244 | Set_Etype (R_Cno, Typ); | |
8245 | Set_Raises_Constraint_Error (R_Cno); | |
8246 | Set_Is_Static_Expression (R_Cno, Stat); | |
3f92c93b AC |
8247 | |
8248 | -- Now deal with possible local raise handling | |
8249 | ||
8250 | Possible_Local_Raise (R_Cno, Standard_Constraint_Error); | |
70482933 RK |
8251 | end Install_Static_Check; |
8252 | ||
acad3c0a AC |
8253 | ------------------------- |
8254 | -- Is_Check_Suppressed -- | |
8255 | ------------------------- | |
8256 | ||
8257 | function Is_Check_Suppressed (E : Entity_Id; C : Check_Id) return Boolean is | |
8258 | Ptr : Suppress_Stack_Entry_Ptr; | |
8259 | ||
8260 | begin | |
8261 | -- First search the local entity suppress stack. We search this from the | |
8262 | -- top of the stack down so that we get the innermost entry that applies | |
8263 | -- to this case if there are nested entries. | |
8264 | ||
8265 | Ptr := Local_Suppress_Stack_Top; | |
8266 | while Ptr /= null loop | |
8267 | if (Ptr.Entity = Empty or else Ptr.Entity = E) | |
8268 | and then (Ptr.Check = All_Checks or else Ptr.Check = C) | |
8269 | then | |
8270 | return Ptr.Suppress; | |
8271 | end if; | |
8272 | ||
8273 | Ptr := Ptr.Prev; | |
8274 | end loop; | |
8275 | ||
8276 | -- Now search the global entity suppress table for a matching entry. | |
8277 | -- We also search this from the top down so that if there are multiple | |
8278 | -- pragmas for the same entity, the last one applies (not clear what | |
8279 | -- or whether the RM specifies this handling, but it seems reasonable). | |
8280 | ||
8281 | Ptr := Global_Suppress_Stack_Top; | |
8282 | while Ptr /= null loop | |
8283 | if (Ptr.Entity = Empty or else Ptr.Entity = E) | |
8284 | and then (Ptr.Check = All_Checks or else Ptr.Check = C) | |
8285 | then | |
8286 | return Ptr.Suppress; | |
8287 | end if; | |
8288 | ||
8289 | Ptr := Ptr.Prev; | |
8290 | end loop; | |
8291 | ||
8292 | -- If we did not find a matching entry, then use the normal scope | |
8293 | -- suppress value after all (actually this will be the global setting | |
8294 | -- since it clearly was not overridden at any point). For a predefined | |
8295 | -- check, we test the specific flag. For a user defined check, we check | |
8296 | -- the All_Checks flag. The Overflow flag requires special handling to | |
90e491a7 | 8297 | -- deal with the General vs Assertion case. |
acad3c0a AC |
8298 | |
8299 | if C = Overflow_Check then | |
8300 | return Overflow_Checks_Suppressed (Empty); | |
90e491a7 | 8301 | |
acad3c0a AC |
8302 | elsif C in Predefined_Check_Id then |
8303 | return Scope_Suppress.Suppress (C); | |
90e491a7 | 8304 | |
acad3c0a AC |
8305 | else |
8306 | return Scope_Suppress.Suppress (All_Checks); | |
8307 | end if; | |
8308 | end Is_Check_Suppressed; | |
8309 | ||
fbf5a39b AC |
8310 | --------------------- |
8311 | -- Kill_All_Checks -- | |
8312 | --------------------- | |
8313 | ||
8314 | procedure Kill_All_Checks is | |
8315 | begin | |
8316 | if Debug_Flag_CC then | |
8317 | w ("Kill_All_Checks"); | |
8318 | end if; | |
8319 | ||
675d6070 TQ |
8320 | -- We reset the number of saved checks to zero, and also modify all |
8321 | -- stack entries for statement ranges to indicate that the number of | |
8322 | -- checks at each level is now zero. | |
fbf5a39b AC |
8323 | |
8324 | Num_Saved_Checks := 0; | |
8325 | ||
67ce0d7e RD |
8326 | -- Note: the Int'Min here avoids any possibility of J being out of |
8327 | -- range when called from e.g. Conditional_Statements_Begin. | |
8328 | ||
8329 | for J in 1 .. Int'Min (Saved_Checks_TOS, Saved_Checks_Stack'Last) loop | |
fbf5a39b AC |
8330 | Saved_Checks_Stack (J) := 0; |
8331 | end loop; | |
8332 | end Kill_All_Checks; | |
8333 | ||
8334 | ----------------- | |
8335 | -- Kill_Checks -- | |
8336 | ----------------- | |
8337 | ||
8338 | procedure Kill_Checks (V : Entity_Id) is | |
8339 | begin | |
8340 | if Debug_Flag_CC then | |
8341 | w ("Kill_Checks for entity", Int (V)); | |
8342 | end if; | |
8343 | ||
8344 | for J in 1 .. Num_Saved_Checks loop | |
8345 | if Saved_Checks (J).Entity = V then | |
8346 | if Debug_Flag_CC then | |
8347 | w (" Checks killed for saved check ", J); | |
8348 | end if; | |
8349 | ||
8350 | Saved_Checks (J).Killed := True; | |
8351 | end if; | |
8352 | end loop; | |
8353 | end Kill_Checks; | |
8354 | ||
70482933 RK |
8355 | ------------------------------ |
8356 | -- Length_Checks_Suppressed -- | |
8357 | ------------------------------ | |
8358 | ||
8359 | function Length_Checks_Suppressed (E : Entity_Id) return Boolean is | |
8360 | begin | |
fbf5a39b AC |
8361 | if Present (E) and then Checks_May_Be_Suppressed (E) then |
8362 | return Is_Check_Suppressed (E, Length_Check); | |
8363 | else | |
3217f71e | 8364 | return Scope_Suppress.Suppress (Length_Check); |
fbf5a39b | 8365 | end if; |
70482933 RK |
8366 | end Length_Checks_Suppressed; |
8367 | ||
acad3c0a AC |
8368 | ----------------------- |
8369 | -- Make_Bignum_Block -- | |
8370 | ----------------------- | |
8371 | ||
8372 | function Make_Bignum_Block (Loc : Source_Ptr) return Node_Id is | |
8373 | M : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uM); | |
acad3c0a AC |
8374 | begin |
8375 | return | |
8376 | Make_Block_Statement (Loc, | |
8e888920 AC |
8377 | Declarations => |
8378 | New_List (Build_SS_Mark_Call (Loc, M)), | |
acad3c0a AC |
8379 | Handled_Statement_Sequence => |
8380 | Make_Handled_Sequence_Of_Statements (Loc, | |
8e888920 | 8381 | Statements => New_List (Build_SS_Release_Call (Loc, M)))); |
acad3c0a AC |
8382 | end Make_Bignum_Block; |
8383 | ||
a7f1b24f RD |
8384 | ---------------------------------- |
8385 | -- Minimize_Eliminate_Overflows -- | |
8386 | ---------------------------------- | |
acad3c0a | 8387 | |
b6b5cca8 AC |
8388 | -- This is a recursive routine that is called at the top of an expression |
8389 | -- tree to properly process overflow checking for a whole subtree by making | |
8390 | -- recursive calls to process operands. This processing may involve the use | |
8391 | -- of bignum or long long integer arithmetic, which will change the types | |
8392 | -- of operands and results. That's why we can't do this bottom up (since | |
5707e389 | 8393 | -- it would interfere with semantic analysis). |
b6b5cca8 | 8394 | |
5707e389 | 8395 | -- What happens is that if MINIMIZED/ELIMINATED mode is in effect then |
a7f1b24f RD |
8396 | -- the operator expansion routines, as well as the expansion routines for |
8397 | -- if/case expression, do nothing (for the moment) except call the routine | |
8398 | -- to apply the overflow check (Apply_Arithmetic_Overflow_Check). That | |
8399 | -- routine does nothing for non top-level nodes, so at the point where the | |
8400 | -- call is made for the top level node, the entire expression subtree has | |
8401 | -- not been expanded, or processed for overflow. All that has to happen as | |
8402 | -- a result of the top level call to this routine. | |
b6b5cca8 AC |
8403 | |
8404 | -- As noted above, the overflow processing works by making recursive calls | |
8405 | -- for the operands, and figuring out what to do, based on the processing | |
8406 | -- of these operands (e.g. if a bignum operand appears, the parent op has | |
8407 | -- to be done in bignum mode), and the determined ranges of the operands. | |
8408 | ||
8409 | -- After possible rewriting of a constituent subexpression node, a call is | |
a40ada7e | 8410 | -- made to either reexpand the node (if nothing has changed) or reanalyze |
5707e389 AC |
8411 | -- the node (if it has been modified by the overflow check processing). The |
8412 | -- Analyzed_Flag is set to False before the reexpand/reanalyze. To avoid | |
8413 | -- a recursive call into the whole overflow apparatus, an important rule | |
a7f1b24f RD |
8414 | -- for this call is that the overflow handling mode must be temporarily set |
8415 | -- to STRICT. | |
b6b5cca8 | 8416 | |
a7f1b24f | 8417 | procedure Minimize_Eliminate_Overflows |
c7e152b5 AC |
8418 | (N : Node_Id; |
8419 | Lo : out Uint; | |
8420 | Hi : out Uint; | |
8421 | Top_Level : Boolean) | |
acad3c0a | 8422 | is |
4b1c4f20 RD |
8423 | Rtyp : constant Entity_Id := Etype (N); |
8424 | pragma Assert (Is_Signed_Integer_Type (Rtyp)); | |
8425 | -- Result type, must be a signed integer type | |
acad3c0a | 8426 | |
15c94a55 | 8427 | Check_Mode : constant Overflow_Mode_Type := Overflow_Check_Mode; |
acad3c0a AC |
8428 | pragma Assert (Check_Mode in Minimized_Or_Eliminated); |
8429 | ||
8430 | Loc : constant Source_Ptr := Sloc (N); | |
8431 | ||
8432 | Rlo, Rhi : Uint; | |
4b1c4f20 | 8433 | -- Ranges of values for right operand (operator case) |
acad3c0a | 8434 | |
a6d25cad AC |
8435 | Llo : Uint := No_Uint; -- initialize to prevent warning |
8436 | Lhi : Uint := No_Uint; -- initialize to prevent warning | |
4b1c4f20 | 8437 | -- Ranges of values for left operand (operator case) |
acad3c0a | 8438 | |
d79059a3 AC |
8439 | LLIB : constant Entity_Id := Base_Type (Standard_Long_Long_Integer); |
8440 | -- Operands and results are of this type when we convert | |
8441 | ||
4b1c4f20 RD |
8442 | LLLo : constant Uint := Intval (Type_Low_Bound (LLIB)); |
8443 | LLHi : constant Uint := Intval (Type_High_Bound (LLIB)); | |
acad3c0a AC |
8444 | -- Bounds of Long_Long_Integer |
8445 | ||
8446 | Binary : constant Boolean := Nkind (N) in N_Binary_Op; | |
8447 | -- Indicates binary operator case | |
8448 | ||
8449 | OK : Boolean; | |
8450 | -- Used in call to Determine_Range | |
8451 | ||
c7e152b5 AC |
8452 | Bignum_Operands : Boolean; |
8453 | -- Set True if one or more operands is already of type Bignum, meaning | |
8454 | -- that for sure (regardless of Top_Level setting) we are committed to | |
4b1c4f20 | 8455 | -- doing the operation in Bignum mode (or in the case of a case or if |
5707e389 | 8456 | -- expression, converting all the dependent expressions to Bignum). |
4b1c4f20 RD |
8457 | |
8458 | Long_Long_Integer_Operands : Boolean; | |
5707e389 | 8459 | -- Set True if one or more operands is already of type Long_Long_Integer |
4b1c4f20 RD |
8460 | -- which means that if the result is known to be in the result type |
8461 | -- range, then we must convert such operands back to the result type. | |
a7f1b24f RD |
8462 | |
8463 | procedure Reanalyze (Typ : Entity_Id; Suppress : Boolean := False); | |
8464 | -- This is called when we have modified the node and we therefore need | |
8465 | -- to reanalyze it. It is important that we reset the mode to STRICT for | |
8466 | -- this reanalysis, since if we leave it in MINIMIZED or ELIMINATED mode | |
a90bd866 | 8467 | -- we would reenter this routine recursively which would not be good. |
a7f1b24f RD |
8468 | -- The argument Suppress is set True if we also want to suppress |
8469 | -- overflow checking for the reexpansion (this is set when we know | |
8470 | -- overflow is not possible). Typ is the type for the reanalysis. | |
8471 | ||
8472 | procedure Reexpand (Suppress : Boolean := False); | |
8473 | -- This is like Reanalyze, but does not do the Analyze step, it only | |
8474 | -- does a reexpansion. We do this reexpansion in STRICT mode, so that | |
8475 | -- instead of reentering the MINIMIZED/ELIMINATED mode processing, we | |
8476 | -- follow the normal expansion path (e.g. converting A**4 to A**2**2). | |
8477 | -- Note that skipping reanalysis is not just an optimization, testing | |
8478 | -- has showed up several complex cases in which reanalyzing an already | |
8479 | -- analyzed node causes incorrect behavior. | |
a40ada7e | 8480 | |
4b1c4f20 RD |
8481 | function In_Result_Range return Boolean; |
8482 | -- Returns True iff Lo .. Hi are within range of the result type | |
c7e152b5 | 8483 | |
a91e9ac7 | 8484 | procedure Max (A : in out Uint; B : Uint); |
5707e389 | 8485 | -- If A is No_Uint, sets A to B, else to UI_Max (A, B) |
a91e9ac7 AC |
8486 | |
8487 | procedure Min (A : in out Uint; B : Uint); | |
5707e389 | 8488 | -- If A is No_Uint, sets A to B, else to UI_Min (A, B) |
a91e9ac7 | 8489 | |
4b1c4f20 RD |
8490 | --------------------- |
8491 | -- In_Result_Range -- | |
8492 | --------------------- | |
8493 | ||
8494 | function In_Result_Range return Boolean is | |
8495 | begin | |
b6b5cca8 AC |
8496 | if Lo = No_Uint or else Hi = No_Uint then |
8497 | return False; | |
8498 | ||
edab6088 | 8499 | elsif Is_OK_Static_Subtype (Etype (N)) then |
4b1c4f20 RD |
8500 | return Lo >= Expr_Value (Type_Low_Bound (Rtyp)) |
8501 | and then | |
8502 | Hi <= Expr_Value (Type_High_Bound (Rtyp)); | |
b6b5cca8 | 8503 | |
4b1c4f20 RD |
8504 | else |
8505 | return Lo >= Expr_Value (Type_Low_Bound (Base_Type (Rtyp))) | |
8506 | and then | |
8507 | Hi <= Expr_Value (Type_High_Bound (Base_Type (Rtyp))); | |
8508 | end if; | |
8509 | end In_Result_Range; | |
8510 | ||
a91e9ac7 AC |
8511 | --------- |
8512 | -- Max -- | |
8513 | --------- | |
8514 | ||
8515 | procedure Max (A : in out Uint; B : Uint) is | |
8516 | begin | |
8517 | if A = No_Uint or else B > A then | |
8518 | A := B; | |
8519 | end if; | |
8520 | end Max; | |
8521 | ||
8522 | --------- | |
8523 | -- Min -- | |
8524 | --------- | |
8525 | ||
8526 | procedure Min (A : in out Uint; B : Uint) is | |
8527 | begin | |
8528 | if A = No_Uint or else B < A then | |
8529 | A := B; | |
8530 | end if; | |
8531 | end Min; | |
8532 | ||
a7f1b24f RD |
8533 | --------------- |
8534 | -- Reanalyze -- | |
8535 | --------------- | |
8536 | ||
8537 | procedure Reanalyze (Typ : Entity_Id; Suppress : Boolean := False) is | |
15c94a55 RD |
8538 | Svg : constant Overflow_Mode_Type := |
8539 | Scope_Suppress.Overflow_Mode_General; | |
8540 | Sva : constant Overflow_Mode_Type := | |
8541 | Scope_Suppress.Overflow_Mode_Assertions; | |
a7f1b24f RD |
8542 | Svo : constant Boolean := |
8543 | Scope_Suppress.Suppress (Overflow_Check); | |
8544 | ||
8545 | begin | |
15c94a55 RD |
8546 | Scope_Suppress.Overflow_Mode_General := Strict; |
8547 | Scope_Suppress.Overflow_Mode_Assertions := Strict; | |
a7f1b24f RD |
8548 | |
8549 | if Suppress then | |
8550 | Scope_Suppress.Suppress (Overflow_Check) := True; | |
8551 | end if; | |
8552 | ||
8553 | Analyze_And_Resolve (N, Typ); | |
8554 | ||
fed8bd87 RD |
8555 | Scope_Suppress.Suppress (Overflow_Check) := Svo; |
8556 | Scope_Suppress.Overflow_Mode_General := Svg; | |
8557 | Scope_Suppress.Overflow_Mode_Assertions := Sva; | |
a7f1b24f RD |
8558 | end Reanalyze; |
8559 | ||
a40ada7e RD |
8560 | -------------- |
8561 | -- Reexpand -- | |
8562 | -------------- | |
8563 | ||
a7f1b24f | 8564 | procedure Reexpand (Suppress : Boolean := False) is |
15c94a55 RD |
8565 | Svg : constant Overflow_Mode_Type := |
8566 | Scope_Suppress.Overflow_Mode_General; | |
8567 | Sva : constant Overflow_Mode_Type := | |
8568 | Scope_Suppress.Overflow_Mode_Assertions; | |
a7f1b24f RD |
8569 | Svo : constant Boolean := |
8570 | Scope_Suppress.Suppress (Overflow_Check); | |
8571 | ||
a40ada7e | 8572 | begin |
15c94a55 RD |
8573 | Scope_Suppress.Overflow_Mode_General := Strict; |
8574 | Scope_Suppress.Overflow_Mode_Assertions := Strict; | |
a40ada7e | 8575 | Set_Analyzed (N, False); |
a7f1b24f RD |
8576 | |
8577 | if Suppress then | |
8578 | Scope_Suppress.Suppress (Overflow_Check) := True; | |
8579 | end if; | |
8580 | ||
a40ada7e | 8581 | Expand (N); |
a7f1b24f | 8582 | |
fed8bd87 RD |
8583 | Scope_Suppress.Suppress (Overflow_Check) := Svo; |
8584 | Scope_Suppress.Overflow_Mode_General := Svg; | |
8585 | Scope_Suppress.Overflow_Mode_Assertions := Sva; | |
a40ada7e RD |
8586 | end Reexpand; |
8587 | ||
a7f1b24f | 8588 | -- Start of processing for Minimize_Eliminate_Overflows |
a91e9ac7 | 8589 | |
acad3c0a | 8590 | begin |
bc3fb397 AC |
8591 | -- Default initialize Lo and Hi since these are not guaranteed to be |
8592 | -- set otherwise. | |
8593 | ||
8594 | Lo := No_Uint; | |
8595 | Hi := No_Uint; | |
8596 | ||
4b1c4f20 | 8597 | -- Case where we do not have a signed integer arithmetic operation |
acad3c0a AC |
8598 | |
8599 | if not Is_Signed_Integer_Arithmetic_Op (N) then | |
8600 | ||
8601 | -- Use the normal Determine_Range routine to get the range. We | |
8602 | -- don't require operands to be valid, invalid values may result in | |
8603 | -- rubbish results where the result has not been properly checked for | |
a90bd866 | 8604 | -- overflow, that's fine. |
acad3c0a AC |
8605 | |
8606 | Determine_Range (N, OK, Lo, Hi, Assume_Valid => False); | |
8607 | ||
5707e389 | 8608 | -- If Determine_Range did not work (can this in fact happen? Not |
acad3c0a AC |
8609 | -- clear but might as well protect), use type bounds. |
8610 | ||
8611 | if not OK then | |
8612 | Lo := Intval (Type_Low_Bound (Base_Type (Etype (N)))); | |
8613 | Hi := Intval (Type_High_Bound (Base_Type (Etype (N)))); | |
8614 | end if; | |
8615 | ||
8616 | -- If we don't have a binary operator, all we have to do is to set | |
637a41a5 | 8617 | -- the Hi/Lo range, so we are done. |
acad3c0a AC |
8618 | |
8619 | return; | |
8620 | ||
4b1c4f20 RD |
8621 | -- Processing for if expression |
8622 | ||
9b16cb57 | 8623 | elsif Nkind (N) = N_If_Expression then |
4b1c4f20 RD |
8624 | declare |
8625 | Then_DE : constant Node_Id := Next (First (Expressions (N))); | |
8626 | Else_DE : constant Node_Id := Next (Then_DE); | |
8627 | ||
8628 | begin | |
8629 | Bignum_Operands := False; | |
8630 | ||
a7f1b24f | 8631 | Minimize_Eliminate_Overflows |
4b1c4f20 RD |
8632 | (Then_DE, Lo, Hi, Top_Level => False); |
8633 | ||
8634 | if Lo = No_Uint then | |
8635 | Bignum_Operands := True; | |
8636 | end if; | |
8637 | ||
a7f1b24f | 8638 | Minimize_Eliminate_Overflows |
4b1c4f20 RD |
8639 | (Else_DE, Rlo, Rhi, Top_Level => False); |
8640 | ||
8641 | if Rlo = No_Uint then | |
8642 | Bignum_Operands := True; | |
8643 | else | |
8644 | Long_Long_Integer_Operands := | |
8645 | Etype (Then_DE) = LLIB or else Etype (Else_DE) = LLIB; | |
8646 | ||
8647 | Min (Lo, Rlo); | |
8648 | Max (Hi, Rhi); | |
8649 | end if; | |
8650 | ||
5707e389 AC |
8651 | -- If at least one of our operands is now Bignum, we must rebuild |
8652 | -- the if expression to use Bignum operands. We will analyze the | |
4b1c4f20 | 8653 | -- rebuilt if expression with overflow checks off, since once we |
a90bd866 | 8654 | -- are in bignum mode, we are all done with overflow checks. |
4b1c4f20 RD |
8655 | |
8656 | if Bignum_Operands then | |
8657 | Rewrite (N, | |
9b16cb57 | 8658 | Make_If_Expression (Loc, |
4b1c4f20 RD |
8659 | Expressions => New_List ( |
8660 | Remove_Head (Expressions (N)), | |
8661 | Convert_To_Bignum (Then_DE), | |
8662 | Convert_To_Bignum (Else_DE)), | |
8663 | Is_Elsif => Is_Elsif (N))); | |
8664 | ||
a7f1b24f | 8665 | Reanalyze (RTE (RE_Bignum), Suppress => True); |
4b1c4f20 RD |
8666 | |
8667 | -- If we have no Long_Long_Integer operands, then we are in result | |
8668 | -- range, since it means that none of our operands felt the need | |
8669 | -- to worry about overflow (otherwise it would have already been | |
a40ada7e RD |
8670 | -- converted to long long integer or bignum). We reexpand to |
8671 | -- complete the expansion of the if expression (but we do not | |
8672 | -- need to reanalyze). | |
4b1c4f20 RD |
8673 | |
8674 | elsif not Long_Long_Integer_Operands then | |
8675 | Set_Do_Overflow_Check (N, False); | |
a7f1b24f | 8676 | Reexpand; |
4b1c4f20 RD |
8677 | |
8678 | -- Otherwise convert us to long long integer mode. Note that we | |
8679 | -- don't need any further overflow checking at this level. | |
8680 | ||
8681 | else | |
8682 | Convert_To_And_Rewrite (LLIB, Then_DE); | |
8683 | Convert_To_And_Rewrite (LLIB, Else_DE); | |
8684 | Set_Etype (N, LLIB); | |
b6b5cca8 AC |
8685 | |
8686 | -- Now reanalyze with overflow checks off | |
8687 | ||
4b1c4f20 | 8688 | Set_Do_Overflow_Check (N, False); |
a7f1b24f | 8689 | Reanalyze (LLIB, Suppress => True); |
4b1c4f20 RD |
8690 | end if; |
8691 | end; | |
8692 | ||
8693 | return; | |
8694 | ||
8695 | -- Here for case expression | |
8696 | ||
8697 | elsif Nkind (N) = N_Case_Expression then | |
8698 | Bignum_Operands := False; | |
8699 | Long_Long_Integer_Operands := False; | |
4b1c4f20 RD |
8700 | |
8701 | declare | |
b6b5cca8 | 8702 | Alt : Node_Id; |
4b1c4f20 RD |
8703 | |
8704 | begin | |
8705 | -- Loop through expressions applying recursive call | |
8706 | ||
8707 | Alt := First (Alternatives (N)); | |
8708 | while Present (Alt) loop | |
8709 | declare | |
8710 | Aexp : constant Node_Id := Expression (Alt); | |
8711 | ||
8712 | begin | |
a7f1b24f | 8713 | Minimize_Eliminate_Overflows |
4b1c4f20 RD |
8714 | (Aexp, Lo, Hi, Top_Level => False); |
8715 | ||
8716 | if Lo = No_Uint then | |
8717 | Bignum_Operands := True; | |
8718 | elsif Etype (Aexp) = LLIB then | |
8719 | Long_Long_Integer_Operands := True; | |
8720 | end if; | |
8721 | end; | |
8722 | ||
8723 | Next (Alt); | |
8724 | end loop; | |
8725 | ||
8726 | -- If we have no bignum or long long integer operands, it means | |
8727 | -- that none of our dependent expressions could raise overflow. | |
8728 | -- In this case, we simply return with no changes except for | |
8729 | -- resetting the overflow flag, since we are done with overflow | |
a40ada7e RD |
8730 | -- checks for this node. We will reexpand to get the needed |
8731 | -- expansion for the case expression, but we do not need to | |
5707e389 | 8732 | -- reanalyze, since nothing has changed. |
4b1c4f20 | 8733 | |
b6b5cca8 | 8734 | if not (Bignum_Operands or Long_Long_Integer_Operands) then |
4b1c4f20 | 8735 | Set_Do_Overflow_Check (N, False); |
a7f1b24f | 8736 | Reexpand (Suppress => True); |
4b1c4f20 RD |
8737 | |
8738 | -- Otherwise we are going to rebuild the case expression using | |
8739 | -- either bignum or long long integer operands throughout. | |
8740 | ||
8741 | else | |
b6b5cca8 | 8742 | declare |
a6b13d32 | 8743 | Rtype : Entity_Id := Empty; |
b6b5cca8 AC |
8744 | New_Alts : List_Id; |
8745 | New_Exp : Node_Id; | |
8746 | ||
8747 | begin | |
8748 | New_Alts := New_List; | |
8749 | Alt := First (Alternatives (N)); | |
8750 | while Present (Alt) loop | |
8751 | if Bignum_Operands then | |
8752 | New_Exp := Convert_To_Bignum (Expression (Alt)); | |
8753 | Rtype := RTE (RE_Bignum); | |
8754 | else | |
8755 | New_Exp := Convert_To (LLIB, Expression (Alt)); | |
8756 | Rtype := LLIB; | |
8757 | end if; | |
4b1c4f20 | 8758 | |
b6b5cca8 AC |
8759 | Append_To (New_Alts, |
8760 | Make_Case_Expression_Alternative (Sloc (Alt), | |
8761 | Actions => No_List, | |
8762 | Discrete_Choices => Discrete_Choices (Alt), | |
8763 | Expression => New_Exp)); | |
4b1c4f20 | 8764 | |
b6b5cca8 AC |
8765 | Next (Alt); |
8766 | end loop; | |
4b1c4f20 | 8767 | |
b6b5cca8 AC |
8768 | Rewrite (N, |
8769 | Make_Case_Expression (Loc, | |
8770 | Expression => Expression (N), | |
8771 | Alternatives => New_Alts)); | |
4b1c4f20 | 8772 | |
a6b13d32 | 8773 | pragma Assert (Present (Rtype)); |
a7f1b24f | 8774 | Reanalyze (Rtype, Suppress => True); |
b6b5cca8 | 8775 | end; |
4b1c4f20 RD |
8776 | end if; |
8777 | end; | |
8778 | ||
8779 | return; | |
8780 | end if; | |
8781 | ||
8782 | -- If we have an arithmetic operator we make recursive calls on the | |
acad3c0a | 8783 | -- operands to get the ranges (and to properly process the subtree |
637a41a5 | 8784 | -- that lies below us). |
acad3c0a | 8785 | |
a7f1b24f | 8786 | Minimize_Eliminate_Overflows |
4b1c4f20 | 8787 | (Right_Opnd (N), Rlo, Rhi, Top_Level => False); |
acad3c0a | 8788 | |
4b1c4f20 | 8789 | if Binary then |
a7f1b24f | 8790 | Minimize_Eliminate_Overflows |
4b1c4f20 | 8791 | (Left_Opnd (N), Llo, Lhi, Top_Level => False); |
acad3c0a AC |
8792 | end if; |
8793 | ||
b6b5cca8 AC |
8794 | -- Record if we have Long_Long_Integer operands |
8795 | ||
8796 | Long_Long_Integer_Operands := | |
8797 | Etype (Right_Opnd (N)) = LLIB | |
8798 | or else (Binary and then Etype (Left_Opnd (N)) = LLIB); | |
8799 | ||
8800 | -- If either operand is a bignum, then result will be a bignum and we | |
8801 | -- don't need to do any range analysis. As previously discussed we could | |
8802 | -- do range analysis in such cases, but it could mean working with giant | |
8803 | -- numbers at compile time for very little gain (the number of cases | |
5707e389 | 8804 | -- in which we could slip back from bignum mode is small). |
acad3c0a AC |
8805 | |
8806 | if Rlo = No_Uint or else (Binary and then Llo = No_Uint) then | |
8807 | Lo := No_Uint; | |
8808 | Hi := No_Uint; | |
c7e152b5 | 8809 | Bignum_Operands := True; |
acad3c0a AC |
8810 | |
8811 | -- Otherwise compute result range | |
8812 | ||
8813 | else | |
c7e152b5 AC |
8814 | Bignum_Operands := False; |
8815 | ||
acad3c0a AC |
8816 | case Nkind (N) is |
8817 | ||
8818 | -- Absolute value | |
8819 | ||
8820 | when N_Op_Abs => | |
8821 | Lo := Uint_0; | |
6cb3037c | 8822 | Hi := UI_Max (abs Rlo, abs Rhi); |
acad3c0a AC |
8823 | |
8824 | -- Addition | |
8825 | ||
8826 | when N_Op_Add => | |
8827 | Lo := Llo + Rlo; | |
8828 | Hi := Lhi + Rhi; | |
8829 | ||
8830 | -- Division | |
8831 | ||
8832 | when N_Op_Divide => | |
a91e9ac7 | 8833 | |
967fb65e | 8834 | -- If the right operand can only be zero, set 0..0 |
a91e9ac7 | 8835 | |
967fb65e AC |
8836 | if Rlo = 0 and then Rhi = 0 then |
8837 | Lo := Uint_0; | |
8838 | Hi := Uint_0; | |
a91e9ac7 | 8839 | |
967fb65e AC |
8840 | -- Possible bounds of division must come from dividing end |
8841 | -- values of the input ranges (four possibilities), provided | |
8842 | -- zero is not included in the possible values of the right | |
8843 | -- operand. | |
8844 | ||
8845 | -- Otherwise, we just consider two intervals of values for | |
8846 | -- the right operand: the interval of negative values (up to | |
8847 | -- -1) and the interval of positive values (starting at 1). | |
8848 | -- Since division by 1 is the identity, and division by -1 | |
8849 | -- is negation, we get all possible bounds of division in that | |
8850 | -- case by considering: | |
8851 | -- - all values from the division of end values of input | |
8852 | -- ranges; | |
8853 | -- - the end values of the left operand; | |
8854 | -- - the negation of the end values of the left operand. | |
a91e9ac7 | 8855 | |
967fb65e AC |
8856 | else |
8857 | declare | |
8858 | Mrk : constant Uintp.Save_Mark := Mark; | |
8859 | -- Mark so we can release the RR and Ev values | |
a91e9ac7 | 8860 | |
967fb65e AC |
8861 | Ev1 : Uint; |
8862 | Ev2 : Uint; | |
8863 | Ev3 : Uint; | |
8864 | Ev4 : Uint; | |
a91e9ac7 | 8865 | |
967fb65e AC |
8866 | begin |
8867 | -- Discard extreme values of zero for the divisor, since | |
8868 | -- they will simply result in an exception in any case. | |
a91e9ac7 | 8869 | |
967fb65e AC |
8870 | if Rlo = 0 then |
8871 | Rlo := Uint_1; | |
8872 | elsif Rhi = 0 then | |
8873 | Rhi := -Uint_1; | |
a91e9ac7 | 8874 | end if; |
a91e9ac7 | 8875 | |
967fb65e AC |
8876 | -- Compute possible bounds coming from dividing end |
8877 | -- values of the input ranges. | |
a91e9ac7 | 8878 | |
967fb65e AC |
8879 | Ev1 := Llo / Rlo; |
8880 | Ev2 := Llo / Rhi; | |
8881 | Ev3 := Lhi / Rlo; | |
8882 | Ev4 := Lhi / Rhi; | |
a91e9ac7 | 8883 | |
967fb65e AC |
8884 | Lo := UI_Min (UI_Min (Ev1, Ev2), UI_Min (Ev3, Ev4)); |
8885 | Hi := UI_Max (UI_Max (Ev1, Ev2), UI_Max (Ev3, Ev4)); | |
a91e9ac7 | 8886 | |
967fb65e AC |
8887 | -- If the right operand can be both negative or positive, |
8888 | -- include the end values of the left operand in the | |
8889 | -- extreme values, as well as their negation. | |
a91e9ac7 | 8890 | |
967fb65e AC |
8891 | if Rlo < 0 and then Rhi > 0 then |
8892 | Ev1 := Llo; | |
8893 | Ev2 := -Llo; | |
8894 | Ev3 := Lhi; | |
8895 | Ev4 := -Lhi; | |
a91e9ac7 | 8896 | |
967fb65e AC |
8897 | Min (Lo, |
8898 | UI_Min (UI_Min (Ev1, Ev2), UI_Min (Ev3, Ev4))); | |
8899 | Max (Hi, | |
8900 | UI_Max (UI_Max (Ev1, Ev2), UI_Max (Ev3, Ev4))); | |
a91e9ac7 | 8901 | end if; |
a91e9ac7 | 8902 | |
967fb65e | 8903 | -- Release the RR and Ev values |
a91e9ac7 | 8904 | |
967fb65e AC |
8905 | Release_And_Save (Mrk, Lo, Hi); |
8906 | end; | |
8907 | end if; | |
acad3c0a AC |
8908 | |
8909 | -- Exponentiation | |
8910 | ||
8911 | when N_Op_Expon => | |
6cb3037c AC |
8912 | |
8913 | -- Discard negative values for the exponent, since they will | |
8914 | -- simply result in an exception in any case. | |
8915 | ||
8916 | if Rhi < 0 then | |
8917 | Rhi := Uint_0; | |
8918 | elsif Rlo < 0 then | |
8919 | Rlo := Uint_0; | |
8920 | end if; | |
8921 | ||
8922 | -- Estimate number of bits in result before we go computing | |
8923 | -- giant useless bounds. Basically the number of bits in the | |
8924 | -- result is the number of bits in the base multiplied by the | |
8925 | -- value of the exponent. If this is big enough that the result | |
8926 | -- definitely won't fit in Long_Long_Integer, switch to bignum | |
8927 | -- mode immediately, and avoid computing giant bounds. | |
8928 | ||
8929 | -- The comparison here is approximate, but conservative, it | |
8930 | -- only clicks on cases that are sure to exceed the bounds. | |
8931 | ||
8932 | if Num_Bits (UI_Max (abs Llo, abs Lhi)) * Rhi + 1 > 100 then | |
8933 | Lo := No_Uint; | |
8934 | Hi := No_Uint; | |
8935 | ||
8936 | -- If right operand is zero then result is 1 | |
8937 | ||
8938 | elsif Rhi = 0 then | |
8939 | Lo := Uint_1; | |
8940 | Hi := Uint_1; | |
8941 | ||
8942 | else | |
8943 | -- High bound comes either from exponentiation of largest | |
967fb65e AC |
8944 | -- positive value to largest exponent value, or from |
8945 | -- the exponentiation of most negative value to an | |
8946 | -- even exponent. | |
6cb3037c AC |
8947 | |
8948 | declare | |
8949 | Hi1, Hi2 : Uint; | |
8950 | ||
8951 | begin | |
967fb65e | 8952 | if Lhi > 0 then |
6cb3037c AC |
8953 | Hi1 := Lhi ** Rhi; |
8954 | else | |
8955 | Hi1 := Uint_0; | |
8956 | end if; | |
8957 | ||
8958 | if Llo < 0 then | |
8959 | if Rhi mod 2 = 0 then | |
6cb3037c | 8960 | Hi2 := Llo ** Rhi; |
967fb65e AC |
8961 | else |
8962 | Hi2 := Llo ** (Rhi - 1); | |
6cb3037c AC |
8963 | end if; |
8964 | else | |
8965 | Hi2 := Uint_0; | |
8966 | end if; | |
8967 | ||
8968 | Hi := UI_Max (Hi1, Hi2); | |
8969 | end; | |
8970 | ||
8971 | -- Result can only be negative if base can be negative | |
8972 | ||
8973 | if Llo < 0 then | |
5707e389 | 8974 | if Rhi mod 2 = 0 then |
6cb3037c AC |
8975 | Lo := Llo ** (Rhi - 1); |
8976 | else | |
8977 | Lo := Llo ** Rhi; | |
8978 | end if; | |
8979 | ||
5707e389 | 8980 | -- Otherwise low bound is minimum ** minimum |
6cb3037c AC |
8981 | |
8982 | else | |
8983 | Lo := Llo ** Rlo; | |
8984 | end if; | |
8985 | end if; | |
acad3c0a AC |
8986 | |
8987 | -- Negation | |
8988 | ||
8989 | when N_Op_Minus => | |
8990 | Lo := -Rhi; | |
8991 | Hi := -Rlo; | |
8992 | ||
8993 | -- Mod | |
8994 | ||
8995 | when N_Op_Mod => | |
a91e9ac7 | 8996 | declare |
967fb65e | 8997 | Maxabs : constant Uint := UI_Max (abs Rlo, abs Rhi) - 1; |
a91e9ac7 AC |
8998 | -- This is the maximum absolute value of the result |
8999 | ||
9000 | begin | |
9001 | Lo := Uint_0; | |
9002 | Hi := Uint_0; | |
9003 | ||
9004 | -- The result depends only on the sign and magnitude of | |
9005 | -- the right operand, it does not depend on the sign or | |
9006 | -- magnitude of the left operand. | |
9007 | ||
9008 | if Rlo < 0 then | |
9009 | Lo := -Maxabs; | |
9010 | end if; | |
9011 | ||
9012 | if Rhi > 0 then | |
9013 | Hi := Maxabs; | |
9014 | end if; | |
9015 | end; | |
acad3c0a AC |
9016 | |
9017 | -- Multiplication | |
9018 | ||
9019 | when N_Op_Multiply => | |
d79059a3 AC |
9020 | |
9021 | -- Possible bounds of multiplication must come from multiplying | |
9022 | -- end values of the input ranges (four possibilities). | |
9023 | ||
9024 | declare | |
9025 | Mrk : constant Uintp.Save_Mark := Mark; | |
9026 | -- Mark so we can release the Ev values | |
9027 | ||
9028 | Ev1 : constant Uint := Llo * Rlo; | |
9029 | Ev2 : constant Uint := Llo * Rhi; | |
9030 | Ev3 : constant Uint := Lhi * Rlo; | |
9031 | Ev4 : constant Uint := Lhi * Rhi; | |
9032 | ||
9033 | begin | |
9034 | Lo := UI_Min (UI_Min (Ev1, Ev2), UI_Min (Ev3, Ev4)); | |
9035 | Hi := UI_Max (UI_Max (Ev1, Ev2), UI_Max (Ev3, Ev4)); | |
9036 | ||
9037 | -- Release the Ev values | |
9038 | ||
9039 | Release_And_Save (Mrk, Lo, Hi); | |
9040 | end; | |
acad3c0a AC |
9041 | |
9042 | -- Plus operator (affirmation) | |
9043 | ||
9044 | when N_Op_Plus => | |
9045 | Lo := Rlo; | |
9046 | Hi := Rhi; | |
9047 | ||
9048 | -- Remainder | |
9049 | ||
9050 | when N_Op_Rem => | |
a91e9ac7 | 9051 | declare |
967fb65e | 9052 | Maxabs : constant Uint := UI_Max (abs Rlo, abs Rhi) - 1; |
a91e9ac7 | 9053 | -- This is the maximum absolute value of the result. Note |
967fb65e AC |
9054 | -- that the result range does not depend on the sign of the |
9055 | -- right operand. | |
a91e9ac7 AC |
9056 | |
9057 | begin | |
9058 | Lo := Uint_0; | |
9059 | Hi := Uint_0; | |
9060 | ||
9061 | -- Case of left operand negative, which results in a range | |
9062 | -- of -Maxabs .. 0 for those negative values. If there are | |
9063 | -- no negative values then Lo value of result is always 0. | |
9064 | ||
9065 | if Llo < 0 then | |
9066 | Lo := -Maxabs; | |
9067 | end if; | |
9068 | ||
9069 | -- Case of left operand positive | |
9070 | ||
9071 | if Lhi > 0 then | |
9072 | Hi := Maxabs; | |
9073 | end if; | |
9074 | end; | |
acad3c0a AC |
9075 | |
9076 | -- Subtract | |
9077 | ||
9078 | when N_Op_Subtract => | |
9079 | Lo := Llo - Rhi; | |
9080 | Hi := Lhi - Rlo; | |
9081 | ||
9082 | -- Nothing else should be possible | |
9083 | ||
9084 | when others => | |
9085 | raise Program_Error; | |
acad3c0a AC |
9086 | end case; |
9087 | end if; | |
9088 | ||
a40ada7e | 9089 | -- Here for the case where we have not rewritten anything (no bignum |
5707e389 AC |
9090 | -- operands or long long integer operands), and we know the result. |
9091 | -- If we know we are in the result range, and we do not have Bignum | |
9092 | -- operands or Long_Long_Integer operands, we can just reexpand with | |
9093 | -- overflow checks turned off (since we know we cannot have overflow). | |
9094 | -- As always the reexpansion is required to complete expansion of the | |
9095 | -- operator, but we do not need to reanalyze, and we prevent recursion | |
9096 | -- by suppressing the check. | |
b6b5cca8 AC |
9097 | |
9098 | if not (Bignum_Operands or Long_Long_Integer_Operands) | |
9099 | and then In_Result_Range | |
9100 | then | |
9101 | Set_Do_Overflow_Check (N, False); | |
a7f1b24f | 9102 | Reexpand (Suppress => True); |
b6b5cca8 AC |
9103 | return; |
9104 | ||
9105 | -- Here we know that we are not in the result range, and in the general | |
5707e389 AC |
9106 | -- case we will move into either the Bignum or Long_Long_Integer domain |
9107 | -- to compute the result. However, there is one exception. If we are | |
9108 | -- at the top level, and we do not have Bignum or Long_Long_Integer | |
9109 | -- operands, we will have to immediately convert the result back to | |
9110 | -- the result type, so there is no point in Bignum/Long_Long_Integer | |
9111 | -- fiddling. | |
b6b5cca8 AC |
9112 | |
9113 | elsif Top_Level | |
9114 | and then not (Bignum_Operands or Long_Long_Integer_Operands) | |
2352eadb AC |
9115 | |
9116 | -- One further refinement. If we are at the top level, but our parent | |
9117 | -- is a type conversion, then go into bignum or long long integer node | |
9118 | -- since the result will be converted to that type directly without | |
9119 | -- going through the result type, and we may avoid an overflow. This | |
9120 | -- is the case for example of Long_Long_Integer (A ** 4), where A is | |
9121 | -- of type Integer, and the result A ** 4 fits in Long_Long_Integer | |
9122 | -- but does not fit in Integer. | |
9123 | ||
9124 | and then Nkind (Parent (N)) /= N_Type_Conversion | |
b6b5cca8 | 9125 | then |
a7f1b24f | 9126 | -- Here keep original types, but we need to complete analysis |
b6b5cca8 AC |
9127 | |
9128 | -- One subtlety. We can't just go ahead and do an analyze operation | |
5707e389 AC |
9129 | -- here because it will cause recursion into the whole MINIMIZED/ |
9130 | -- ELIMINATED overflow processing which is not what we want. Here | |
b6b5cca8 | 9131 | -- we are at the top level, and we need a check against the result |
a90bd866 | 9132 | -- mode (i.e. we want to use STRICT mode). So do exactly that. |
a40ada7e RD |
9133 | -- Also, we have not modified the node, so this is a case where |
9134 | -- we need to reexpand, but not reanalyze. | |
b6b5cca8 | 9135 | |
a7f1b24f | 9136 | Reexpand; |
b6b5cca8 AC |
9137 | return; |
9138 | ||
9139 | -- Cases where we do the operation in Bignum mode. This happens either | |
acad3c0a | 9140 | -- because one of our operands is in Bignum mode already, or because |
6cb3037c AC |
9141 | -- the computed bounds are outside the bounds of Long_Long_Integer, |
9142 | -- which in some cases can be indicated by Hi and Lo being No_Uint. | |
acad3c0a AC |
9143 | |
9144 | -- Note: we could do better here and in some cases switch back from | |
9145 | -- Bignum mode to normal mode, e.g. big mod 2 must be in the range | |
9146 | -- 0 .. 1, but the cases are rare and it is not worth the effort. | |
9147 | -- Failing to do this switching back is only an efficiency issue. | |
9148 | ||
b6b5cca8 | 9149 | elsif Lo = No_Uint or else Lo < LLLo or else Hi > LLHi then |
acad3c0a | 9150 | |
c7e152b5 | 9151 | -- OK, we are definitely outside the range of Long_Long_Integer. The |
b6b5cca8 | 9152 | -- question is whether to move to Bignum mode, or stay in the domain |
c7e152b5 AC |
9153 | -- of Long_Long_Integer, signalling that an overflow check is needed. |
9154 | ||
9155 | -- Obviously in MINIMIZED mode we stay with LLI, since we are not in | |
9156 | -- the Bignum business. In ELIMINATED mode, we will normally move | |
9157 | -- into Bignum mode, but there is an exception if neither of our | |
9158 | -- operands is Bignum now, and we are at the top level (Top_Level | |
9159 | -- set True). In this case, there is no point in moving into Bignum | |
9160 | -- mode to prevent overflow if the caller will immediately convert | |
9161 | -- the Bignum value back to LLI with an overflow check. It's more | |
a7f1b24f | 9162 | -- efficient to stay in LLI mode with an overflow check (if needed) |
c7e152b5 AC |
9163 | |
9164 | if Check_Mode = Minimized | |
9165 | or else (Top_Level and not Bignum_Operands) | |
9166 | then | |
a7f1b24f RD |
9167 | if Do_Overflow_Check (N) then |
9168 | Enable_Overflow_Check (N); | |
9169 | end if; | |
acad3c0a | 9170 | |
a7f1b24f RD |
9171 | -- The result now has to be in Long_Long_Integer mode, so adjust |
9172 | -- the possible range to reflect this. Note these calls also | |
9173 | -- change No_Uint values from the top level case to LLI bounds. | |
c7e152b5 AC |
9174 | |
9175 | Max (Lo, LLLo); | |
9176 | Min (Hi, LLHi); | |
9177 | ||
9178 | -- Otherwise we are in ELIMINATED mode and we switch to Bignum mode | |
acad3c0a AC |
9179 | |
9180 | else | |
9181 | pragma Assert (Check_Mode = Eliminated); | |
9182 | ||
9183 | declare | |
9184 | Fent : Entity_Id; | |
9185 | Args : List_Id; | |
9186 | ||
9187 | begin | |
9188 | case Nkind (N) is | |
d8f43ee6 | 9189 | when N_Op_Abs => |
acad3c0a AC |
9190 | Fent := RTE (RE_Big_Abs); |
9191 | ||
d8f43ee6 | 9192 | when N_Op_Add => |
acad3c0a AC |
9193 | Fent := RTE (RE_Big_Add); |
9194 | ||
d8f43ee6 | 9195 | when N_Op_Divide => |
acad3c0a AC |
9196 | Fent := RTE (RE_Big_Div); |
9197 | ||
d8f43ee6 | 9198 | when N_Op_Expon => |
acad3c0a AC |
9199 | Fent := RTE (RE_Big_Exp); |
9200 | ||
d8f43ee6 | 9201 | when N_Op_Minus => |
acad3c0a AC |
9202 | Fent := RTE (RE_Big_Neg); |
9203 | ||
d8f43ee6 | 9204 | when N_Op_Mod => |
acad3c0a AC |
9205 | Fent := RTE (RE_Big_Mod); |
9206 | ||
9207 | when N_Op_Multiply => | |
9208 | Fent := RTE (RE_Big_Mul); | |
9209 | ||
d8f43ee6 | 9210 | when N_Op_Rem => |
acad3c0a AC |
9211 | Fent := RTE (RE_Big_Rem); |
9212 | ||
9213 | when N_Op_Subtract => | |
9214 | Fent := RTE (RE_Big_Sub); | |
9215 | ||
9216 | -- Anything else is an internal error, this includes the | |
9217 | -- N_Op_Plus case, since how can plus cause the result | |
9218 | -- to be out of range if the operand is in range? | |
9219 | ||
9220 | when others => | |
9221 | raise Program_Error; | |
9222 | end case; | |
9223 | ||
9224 | -- Construct argument list for Bignum call, converting our | |
9225 | -- operands to Bignum form if they are not already there. | |
9226 | ||
9227 | Args := New_List; | |
9228 | ||
9229 | if Binary then | |
9230 | Append_To (Args, Convert_To_Bignum (Left_Opnd (N))); | |
9231 | end if; | |
9232 | ||
9233 | Append_To (Args, Convert_To_Bignum (Right_Opnd (N))); | |
9234 | ||
9235 | -- Now rewrite the arithmetic operator with a call to the | |
9236 | -- corresponding bignum function. | |
9237 | ||
9238 | Rewrite (N, | |
9239 | Make_Function_Call (Loc, | |
9240 | Name => New_Occurrence_Of (Fent, Loc), | |
9241 | Parameter_Associations => Args)); | |
a7f1b24f | 9242 | Reanalyze (RTE (RE_Bignum), Suppress => True); |
c7e152b5 AC |
9243 | |
9244 | -- Indicate result is Bignum mode | |
9245 | ||
9246 | Lo := No_Uint; | |
9247 | Hi := No_Uint; | |
6cb3037c | 9248 | return; |
acad3c0a AC |
9249 | end; |
9250 | end if; | |
9251 | ||
9252 | -- Otherwise we are in range of Long_Long_Integer, so no overflow | |
6cb3037c | 9253 | -- check is required, at least not yet. |
acad3c0a AC |
9254 | |
9255 | else | |
6cb3037c AC |
9256 | Set_Do_Overflow_Check (N, False); |
9257 | end if; | |
acad3c0a | 9258 | |
b6b5cca8 AC |
9259 | -- Here we are not in Bignum territory, but we may have long long |
9260 | -- integer operands that need special handling. First a special check: | |
9261 | -- If an exponentiation operator exponent is of type Long_Long_Integer, | |
9262 | -- it means we converted it to prevent overflow, but exponentiation | |
9263 | -- requires a Natural right operand, so convert it back to Natural. | |
9264 | -- This conversion may raise an exception which is fine. | |
4b1c4f20 | 9265 | |
b6b5cca8 AC |
9266 | if Nkind (N) = N_Op_Expon and then Etype (Right_Opnd (N)) = LLIB then |
9267 | Convert_To_And_Rewrite (Standard_Natural, Right_Opnd (N)); | |
4b1c4f20 RD |
9268 | end if; |
9269 | ||
6cb3037c AC |
9270 | -- Here we will do the operation in Long_Long_Integer. We do this even |
9271 | -- if we know an overflow check is required, better to do this in long | |
a90bd866 | 9272 | -- long integer mode, since we are less likely to overflow. |
acad3c0a | 9273 | |
6cb3037c AC |
9274 | -- Convert right or only operand to Long_Long_Integer, except that |
9275 | -- we do not touch the exponentiation right operand. | |
acad3c0a | 9276 | |
6cb3037c AC |
9277 | if Nkind (N) /= N_Op_Expon then |
9278 | Convert_To_And_Rewrite (LLIB, Right_Opnd (N)); | |
9279 | end if; | |
acad3c0a | 9280 | |
6cb3037c | 9281 | -- Convert left operand to Long_Long_Integer for binary case |
d79059a3 | 9282 | |
6cb3037c AC |
9283 | if Binary then |
9284 | Convert_To_And_Rewrite (LLIB, Left_Opnd (N)); | |
9285 | end if; | |
9286 | ||
9287 | -- Reset node to unanalyzed | |
9288 | ||
9289 | Set_Analyzed (N, False); | |
9290 | Set_Etype (N, Empty); | |
9291 | Set_Entity (N, Empty); | |
9292 | ||
a91e9ac7 AC |
9293 | -- Now analyze this new node. This reanalysis will complete processing |
9294 | -- for the node. In particular we will complete the expansion of an | |
9295 | -- exponentiation operator (e.g. changing A ** 2 to A * A), and also | |
9296 | -- we will complete any division checks (since we have not changed the | |
9297 | -- setting of the Do_Division_Check flag). | |
acad3c0a | 9298 | |
a7f1b24f | 9299 | -- We do this reanalysis in STRICT mode to avoid recursion into the |
a90bd866 | 9300 | -- MINIMIZED/ELIMINATED handling, since we are now done with that. |
acad3c0a | 9301 | |
a7f1b24f | 9302 | declare |
15c94a55 RD |
9303 | SG : constant Overflow_Mode_Type := |
9304 | Scope_Suppress.Overflow_Mode_General; | |
9305 | SA : constant Overflow_Mode_Type := | |
9306 | Scope_Suppress.Overflow_Mode_Assertions; | |
6cb3037c | 9307 | |
a7f1b24f | 9308 | begin |
15c94a55 RD |
9309 | Scope_Suppress.Overflow_Mode_General := Strict; |
9310 | Scope_Suppress.Overflow_Mode_Assertions := Strict; | |
6cb3037c | 9311 | |
a7f1b24f RD |
9312 | if not Do_Overflow_Check (N) then |
9313 | Reanalyze (LLIB, Suppress => True); | |
9314 | else | |
9315 | Reanalyze (LLIB); | |
9316 | end if; | |
9317 | ||
15c94a55 RD |
9318 | Scope_Suppress.Overflow_Mode_General := SG; |
9319 | Scope_Suppress.Overflow_Mode_Assertions := SA; | |
a7f1b24f RD |
9320 | end; |
9321 | end Minimize_Eliminate_Overflows; | |
acad3c0a AC |
9322 | |
9323 | ------------------------- | |
9324 | -- Overflow_Check_Mode -- | |
9325 | ------------------------- | |
9326 | ||
15c94a55 | 9327 | function Overflow_Check_Mode return Overflow_Mode_Type is |
70482933 | 9328 | begin |
05b34c18 | 9329 | if In_Assertion_Expr = 0 then |
15c94a55 | 9330 | return Scope_Suppress.Overflow_Mode_General; |
fbf5a39b | 9331 | else |
15c94a55 | 9332 | return Scope_Suppress.Overflow_Mode_Assertions; |
fbf5a39b | 9333 | end if; |
acad3c0a AC |
9334 | end Overflow_Check_Mode; |
9335 | ||
9336 | -------------------------------- | |
9337 | -- Overflow_Checks_Suppressed -- | |
9338 | -------------------------------- | |
9339 | ||
9340 | function Overflow_Checks_Suppressed (E : Entity_Id) return Boolean is | |
9341 | begin | |
a7f1b24f RD |
9342 | if Present (E) and then Checks_May_Be_Suppressed (E) then |
9343 | return Is_Check_Suppressed (E, Overflow_Check); | |
9344 | else | |
9345 | return Scope_Suppress.Suppress (Overflow_Check); | |
9346 | end if; | |
70482933 | 9347 | end Overflow_Checks_Suppressed; |
b568955d | 9348 | |
f1c80977 AC |
9349 | --------------------------------- |
9350 | -- Predicate_Checks_Suppressed -- | |
9351 | --------------------------------- | |
9352 | ||
9353 | function Predicate_Checks_Suppressed (E : Entity_Id) return Boolean is | |
9354 | begin | |
9355 | if Present (E) and then Checks_May_Be_Suppressed (E) then | |
9356 | return Is_Check_Suppressed (E, Predicate_Check); | |
9357 | else | |
9358 | return Scope_Suppress.Suppress (Predicate_Check); | |
9359 | end if; | |
9360 | end Predicate_Checks_Suppressed; | |
9361 | ||
70482933 RK |
9362 | ----------------------------- |
9363 | -- Range_Checks_Suppressed -- | |
9364 | ----------------------------- | |
9365 | ||
9366 | function Range_Checks_Suppressed (E : Entity_Id) return Boolean is | |
9367 | begin | |
fbf5a39b | 9368 | if Present (E) then |
21c51f53 | 9369 | if Kill_Range_Checks (E) then |
fbf5a39b | 9370 | return True; |
4bd4bb7f | 9371 | |
fbf5a39b AC |
9372 | elsif Checks_May_Be_Suppressed (E) then |
9373 | return Is_Check_Suppressed (E, Range_Check); | |
9374 | end if; | |
9375 | end if; | |
70482933 | 9376 | |
3217f71e | 9377 | return Scope_Suppress.Suppress (Range_Check); |
70482933 RK |
9378 | end Range_Checks_Suppressed; |
9379 | ||
c064e066 RD |
9380 | ----------------------------------------- |
9381 | -- Range_Or_Validity_Checks_Suppressed -- | |
9382 | ----------------------------------------- | |
9383 | ||
9384 | -- Note: the coding would be simpler here if we simply made appropriate | |
9385 | -- calls to Range/Validity_Checks_Suppressed, but that would result in | |
9386 | -- duplicated checks which we prefer to avoid. | |
9387 | ||
9388 | function Range_Or_Validity_Checks_Suppressed | |
9389 | (Expr : Node_Id) return Boolean | |
9390 | is | |
9391 | begin | |
9392 | -- Immediate return if scope checks suppressed for either check | |
9393 | ||
3217f71e AC |
9394 | if Scope_Suppress.Suppress (Range_Check) |
9395 | or | |
9396 | Scope_Suppress.Suppress (Validity_Check) | |
9397 | then | |
c064e066 RD |
9398 | return True; |
9399 | end if; | |
9400 | ||
9401 | -- If no expression, that's odd, decide that checks are suppressed, | |
9402 | -- since we don't want anyone trying to do checks in this case, which | |
9403 | -- is most likely the result of some other error. | |
9404 | ||
9405 | if No (Expr) then | |
9406 | return True; | |
9407 | end if; | |
9408 | ||
9409 | -- Expression is present, so perform suppress checks on type | |
9410 | ||
9411 | declare | |
9412 | Typ : constant Entity_Id := Etype (Expr); | |
9413 | begin | |
21c51f53 | 9414 | if Checks_May_Be_Suppressed (Typ) |
c064e066 RD |
9415 | and then (Is_Check_Suppressed (Typ, Range_Check) |
9416 | or else | |
9417 | Is_Check_Suppressed (Typ, Validity_Check)) | |
9418 | then | |
9419 | return True; | |
9420 | end if; | |
9421 | end; | |
9422 | ||
9423 | -- If expression is an entity name, perform checks on this entity | |
9424 | ||
9425 | if Is_Entity_Name (Expr) then | |
9426 | declare | |
9427 | Ent : constant Entity_Id := Entity (Expr); | |
9428 | begin | |
9429 | if Checks_May_Be_Suppressed (Ent) then | |
9430 | return Is_Check_Suppressed (Ent, Range_Check) | |
9431 | or else Is_Check_Suppressed (Ent, Validity_Check); | |
9432 | end if; | |
9433 | end; | |
9434 | end if; | |
9435 | ||
9436 | -- If we fall through, no checks suppressed | |
9437 | ||
9438 | return False; | |
9439 | end Range_Or_Validity_Checks_Suppressed; | |
9440 | ||
8cbb664e MG |
9441 | ------------------- |
9442 | -- Remove_Checks -- | |
9443 | ------------------- | |
9444 | ||
9445 | procedure Remove_Checks (Expr : Node_Id) is | |
8cbb664e MG |
9446 | function Process (N : Node_Id) return Traverse_Result; |
9447 | -- Process a single node during the traversal | |
9448 | ||
10303118 BD |
9449 | procedure Traverse is new Traverse_Proc (Process); |
9450 | -- The traversal procedure itself | |
8cbb664e MG |
9451 | |
9452 | ------------- | |
9453 | -- Process -- | |
9454 | ------------- | |
9455 | ||
9456 | function Process (N : Node_Id) return Traverse_Result is | |
9457 | begin | |
9458 | if Nkind (N) not in N_Subexpr then | |
9459 | return Skip; | |
9460 | end if; | |
9461 | ||
9462 | Set_Do_Range_Check (N, False); | |
9463 | ||
9464 | case Nkind (N) is | |
9465 | when N_And_Then => | |
10303118 | 9466 | Traverse (Left_Opnd (N)); |
8cbb664e MG |
9467 | return Skip; |
9468 | ||
9469 | when N_Attribute_Reference => | |
8cbb664e MG |
9470 | Set_Do_Overflow_Check (N, False); |
9471 | ||
8cbb664e MG |
9472 | when N_Function_Call => |
9473 | Set_Do_Tag_Check (N, False); | |
9474 | ||
8cbb664e MG |
9475 | when N_Op => |
9476 | Set_Do_Overflow_Check (N, False); | |
9477 | ||
9478 | case Nkind (N) is | |
9479 | when N_Op_Divide => | |
9480 | Set_Do_Division_Check (N, False); | |
9481 | ||
9482 | when N_Op_And => | |
9483 | Set_Do_Length_Check (N, False); | |
9484 | ||
9485 | when N_Op_Mod => | |
9486 | Set_Do_Division_Check (N, False); | |
9487 | ||
9488 | when N_Op_Or => | |
9489 | Set_Do_Length_Check (N, False); | |
9490 | ||
9491 | when N_Op_Rem => | |
9492 | Set_Do_Division_Check (N, False); | |
9493 | ||
9494 | when N_Op_Xor => | |
9495 | Set_Do_Length_Check (N, False); | |
9496 | ||
9497 | when others => | |
9498 | null; | |
9499 | end case; | |
9500 | ||
9501 | when N_Or_Else => | |
10303118 | 9502 | Traverse (Left_Opnd (N)); |
8cbb664e MG |
9503 | return Skip; |
9504 | ||
9505 | when N_Selected_Component => | |
8cbb664e MG |
9506 | Set_Do_Discriminant_Check (N, False); |
9507 | ||
8cbb664e | 9508 | when N_Type_Conversion => |
fbf5a39b AC |
9509 | Set_Do_Length_Check (N, False); |
9510 | Set_Do_Tag_Check (N, False); | |
8cbb664e | 9511 | Set_Do_Overflow_Check (N, False); |
8cbb664e MG |
9512 | |
9513 | when others => | |
9514 | null; | |
9515 | end case; | |
9516 | ||
9517 | return OK; | |
9518 | end Process; | |
9519 | ||
9520 | -- Start of processing for Remove_Checks | |
9521 | ||
9522 | begin | |
10303118 | 9523 | Traverse (Expr); |
8cbb664e MG |
9524 | end Remove_Checks; |
9525 | ||
70482933 RK |
9526 | ---------------------------- |
9527 | -- Selected_Length_Checks -- | |
9528 | ---------------------------- | |
9529 | ||
9530 | function Selected_Length_Checks | |
9531 | (Ck_Node : Node_Id; | |
9532 | Target_Typ : Entity_Id; | |
9533 | Source_Typ : Entity_Id; | |
6b6fcd3e | 9534 | Warn_Node : Node_Id) return Check_Result |
70482933 RK |
9535 | is |
9536 | Loc : constant Source_Ptr := Sloc (Ck_Node); | |
9537 | S_Typ : Entity_Id; | |
9538 | T_Typ : Entity_Id; | |
9539 | Expr_Actual : Node_Id; | |
9540 | Exptyp : Entity_Id; | |
9541 | Cond : Node_Id := Empty; | |
9542 | Do_Access : Boolean := False; | |
9543 | Wnode : Node_Id := Warn_Node; | |
9544 | Ret_Result : Check_Result := (Empty, Empty); | |
9545 | Num_Checks : Natural := 0; | |
9546 | ||
9547 | procedure Add_Check (N : Node_Id); | |
9548 | -- Adds the action given to Ret_Result if N is non-Empty | |
9549 | ||
9550 | function Get_E_Length (E : Entity_Id; Indx : Nat) return Node_Id; | |
9551 | function Get_N_Length (N : Node_Id; Indx : Nat) return Node_Id; | |
6b6fcd3e | 9552 | -- Comments required ??? |
70482933 RK |
9553 | |
9554 | function Same_Bounds (L : Node_Id; R : Node_Id) return Boolean; | |
9555 | -- True for equal literals and for nodes that denote the same constant | |
c84700e7 | 9556 | -- entity, even if its value is not a static constant. This includes the |
fbf5a39b | 9557 | -- case of a discriminal reference within an init proc. Removes some |
c84700e7 | 9558 | -- obviously superfluous checks. |
70482933 RK |
9559 | |
9560 | function Length_E_Cond | |
9561 | (Exptyp : Entity_Id; | |
9562 | Typ : Entity_Id; | |
6b6fcd3e | 9563 | Indx : Nat) return Node_Id; |
70482933 RK |
9564 | -- Returns expression to compute: |
9565 | -- Typ'Length /= Exptyp'Length | |
9566 | ||
9567 | function Length_N_Cond | |
9568 | (Expr : Node_Id; | |
9569 | Typ : Entity_Id; | |
6b6fcd3e | 9570 | Indx : Nat) return Node_Id; |
70482933 RK |
9571 | -- Returns expression to compute: |
9572 | -- Typ'Length /= Expr'Length | |
9573 | ||
eb6b9c9b GD |
9574 | function Length_Mismatch_Info_Message |
9575 | (Left_Element_Count : Uint; | |
9576 | Right_Element_Count : Uint) return String; | |
9577 | -- Returns a message indicating how many elements were expected | |
9578 | -- (Left_Element_Count) and how many were found (Right_Element_Count). | |
9579 | ||
70482933 RK |
9580 | --------------- |
9581 | -- Add_Check -- | |
9582 | --------------- | |
9583 | ||
9584 | procedure Add_Check (N : Node_Id) is | |
9585 | begin | |
9586 | if Present (N) then | |
9587 | ||
637a41a5 AC |
9588 | -- For now, ignore attempt to place more than two checks ??? |
9589 | -- This is really worrisome, are we really discarding checks ??? | |
70482933 RK |
9590 | |
9591 | if Num_Checks = 2 then | |
9592 | return; | |
9593 | end if; | |
9594 | ||
9595 | pragma Assert (Num_Checks <= 1); | |
9596 | Num_Checks := Num_Checks + 1; | |
9597 | Ret_Result (Num_Checks) := N; | |
9598 | end if; | |
9599 | end Add_Check; | |
9600 | ||
9601 | ------------------ | |
9602 | -- Get_E_Length -- | |
9603 | ------------------ | |
9604 | ||
9605 | function Get_E_Length (E : Entity_Id; Indx : Nat) return Node_Id is | |
11b4899f | 9606 | SE : constant Entity_Id := Scope (E); |
70482933 RK |
9607 | N : Node_Id; |
9608 | E1 : Entity_Id := E; | |
70482933 RK |
9609 | |
9610 | begin | |
9611 | if Ekind (Scope (E)) = E_Record_Type | |
9612 | and then Has_Discriminants (Scope (E)) | |
9613 | then | |
9614 | N := Build_Discriminal_Subtype_Of_Component (E); | |
9615 | ||
9616 | if Present (N) then | |
9617 | Insert_Action (Ck_Node, N); | |
9618 | E1 := Defining_Identifier (N); | |
9619 | end if; | |
9620 | end if; | |
9621 | ||
9622 | if Ekind (E1) = E_String_Literal_Subtype then | |
9623 | return | |
9624 | Make_Integer_Literal (Loc, | |
9625 | Intval => String_Literal_Length (E1)); | |
9626 | ||
11b4899f JM |
9627 | elsif SE /= Standard_Standard |
9628 | and then Ekind (Scope (SE)) = E_Protected_Type | |
9629 | and then Has_Discriminants (Scope (SE)) | |
9630 | and then Has_Completion (Scope (SE)) | |
70482933 RK |
9631 | and then not Inside_Init_Proc |
9632 | then | |
70482933 RK |
9633 | -- If the type whose length is needed is a private component |
9634 | -- constrained by a discriminant, we must expand the 'Length | |
9635 | -- attribute into an explicit computation, using the discriminal | |
9636 | -- of the current protected operation. This is because the actual | |
9637 | -- type of the prival is constructed after the protected opera- | |
9638 | -- tion has been fully expanded. | |
9639 | ||
9640 | declare | |
9641 | Indx_Type : Node_Id; | |
9642 | Lo : Node_Id; | |
9643 | Hi : Node_Id; | |
9644 | Do_Expand : Boolean := False; | |
9645 | ||
9646 | begin | |
9647 | Indx_Type := First_Index (E); | |
9648 | ||
9649 | for J in 1 .. Indx - 1 loop | |
9650 | Next_Index (Indx_Type); | |
9651 | end loop; | |
9652 | ||
939c12d2 | 9653 | Get_Index_Bounds (Indx_Type, Lo, Hi); |
70482933 RK |
9654 | |
9655 | if Nkind (Lo) = N_Identifier | |
9656 | and then Ekind (Entity (Lo)) = E_In_Parameter | |
9657 | then | |
9658 | Lo := Get_Discriminal (E, Lo); | |
9659 | Do_Expand := True; | |
9660 | end if; | |
9661 | ||
9662 | if Nkind (Hi) = N_Identifier | |
9663 | and then Ekind (Entity (Hi)) = E_In_Parameter | |
9664 | then | |
9665 | Hi := Get_Discriminal (E, Hi); | |
9666 | Do_Expand := True; | |
9667 | end if; | |
9668 | ||
9669 | if Do_Expand then | |
9670 | if not Is_Entity_Name (Lo) then | |
fbf5a39b | 9671 | Lo := Duplicate_Subexpr_No_Checks (Lo); |
70482933 RK |
9672 | end if; |
9673 | ||
9674 | if not Is_Entity_Name (Hi) then | |
fbf5a39b | 9675 | Lo := Duplicate_Subexpr_No_Checks (Hi); |
70482933 RK |
9676 | end if; |
9677 | ||
9678 | N := | |
9679 | Make_Op_Add (Loc, | |
9680 | Left_Opnd => | |
9681 | Make_Op_Subtract (Loc, | |
9682 | Left_Opnd => Hi, | |
9683 | Right_Opnd => Lo), | |
9684 | ||
9685 | Right_Opnd => Make_Integer_Literal (Loc, 1)); | |
9686 | return N; | |
9687 | ||
9688 | else | |
9689 | N := | |
9690 | Make_Attribute_Reference (Loc, | |
9691 | Attribute_Name => Name_Length, | |
9692 | Prefix => | |
9693 | New_Occurrence_Of (E1, Loc)); | |
9694 | ||
9695 | if Indx > 1 then | |
9696 | Set_Expressions (N, New_List ( | |
9697 | Make_Integer_Literal (Loc, Indx))); | |
9698 | end if; | |
9699 | ||
9700 | return N; | |
9701 | end if; | |
9702 | end; | |
9703 | ||
9704 | else | |
9705 | N := | |
9706 | Make_Attribute_Reference (Loc, | |
9707 | Attribute_Name => Name_Length, | |
9708 | Prefix => | |
9709 | New_Occurrence_Of (E1, Loc)); | |
9710 | ||
9711 | if Indx > 1 then | |
9712 | Set_Expressions (N, New_List ( | |
9713 | Make_Integer_Literal (Loc, Indx))); | |
9714 | end if; | |
9715 | ||
9716 | return N; | |
70482933 RK |
9717 | end if; |
9718 | end Get_E_Length; | |
9719 | ||
9720 | ------------------ | |
9721 | -- Get_N_Length -- | |
9722 | ------------------ | |
9723 | ||
9724 | function Get_N_Length (N : Node_Id; Indx : Nat) return Node_Id is | |
9725 | begin | |
9726 | return | |
9727 | Make_Attribute_Reference (Loc, | |
9728 | Attribute_Name => Name_Length, | |
9729 | Prefix => | |
fbf5a39b | 9730 | Duplicate_Subexpr_No_Checks (N, Name_Req => True), |
70482933 RK |
9731 | Expressions => New_List ( |
9732 | Make_Integer_Literal (Loc, Indx))); | |
70482933 RK |
9733 | end Get_N_Length; |
9734 | ||
9735 | ------------------- | |
9736 | -- Length_E_Cond -- | |
9737 | ------------------- | |
9738 | ||
9739 | function Length_E_Cond | |
9740 | (Exptyp : Entity_Id; | |
9741 | Typ : Entity_Id; | |
6b6fcd3e | 9742 | Indx : Nat) return Node_Id |
70482933 RK |
9743 | is |
9744 | begin | |
9745 | return | |
9746 | Make_Op_Ne (Loc, | |
9747 | Left_Opnd => Get_E_Length (Typ, Indx), | |
9748 | Right_Opnd => Get_E_Length (Exptyp, Indx)); | |
70482933 RK |
9749 | end Length_E_Cond; |
9750 | ||
9751 | ------------------- | |
9752 | -- Length_N_Cond -- | |
9753 | ------------------- | |
9754 | ||
9755 | function Length_N_Cond | |
9756 | (Expr : Node_Id; | |
9757 | Typ : Entity_Id; | |
6b6fcd3e | 9758 | Indx : Nat) return Node_Id |
70482933 RK |
9759 | is |
9760 | begin | |
9761 | return | |
9762 | Make_Op_Ne (Loc, | |
9763 | Left_Opnd => Get_E_Length (Typ, Indx), | |
9764 | Right_Opnd => Get_N_Length (Expr, Indx)); | |
70482933 RK |
9765 | end Length_N_Cond; |
9766 | ||
eb6b9c9b GD |
9767 | ---------------------------------- |
9768 | -- Length_Mismatch_Info_Message -- | |
9769 | ---------------------------------- | |
9770 | ||
9771 | function Length_Mismatch_Info_Message | |
9772 | (Left_Element_Count : Uint; | |
9773 | Right_Element_Count : Uint) return String | |
9774 | is | |
9775 | ||
9776 | function Plural_Vs_Singular_Ending (Count : Uint) return String; | |
9777 | -- Returns an empty string if Count is 1; otherwise returns "s" | |
9778 | ||
9779 | function Plural_Vs_Singular_Ending (Count : Uint) return String is | |
9780 | begin | |
9781 | if Count = 1 then | |
9782 | return ""; | |
9783 | else | |
9784 | return "s"; | |
9785 | end if; | |
9786 | end Plural_Vs_Singular_Ending; | |
9787 | ||
9788 | begin | |
9789 | return "expected " & UI_Image (Left_Element_Count) | |
9790 | & " element" | |
9791 | & Plural_Vs_Singular_Ending (Left_Element_Count) | |
9792 | & "; found " & UI_Image (Right_Element_Count) | |
9793 | & " element" | |
9794 | & Plural_Vs_Singular_Ending (Right_Element_Count); | |
9795 | end Length_Mismatch_Info_Message; | |
9796 | ||
675d6070 TQ |
9797 | ----------------- |
9798 | -- Same_Bounds -- | |
9799 | ----------------- | |
9800 | ||
70482933 RK |
9801 | function Same_Bounds (L : Node_Id; R : Node_Id) return Boolean is |
9802 | begin | |
9803 | return | |
9804 | (Nkind (L) = N_Integer_Literal | |
9805 | and then Nkind (R) = N_Integer_Literal | |
9806 | and then Intval (L) = Intval (R)) | |
9807 | ||
9808 | or else | |
9809 | (Is_Entity_Name (L) | |
9810 | and then Ekind (Entity (L)) = E_Constant | |
9811 | and then ((Is_Entity_Name (R) | |
9812 | and then Entity (L) = Entity (R)) | |
9813 | or else | |
9814 | (Nkind (R) = N_Type_Conversion | |
9815 | and then Is_Entity_Name (Expression (R)) | |
9816 | and then Entity (L) = Entity (Expression (R))))) | |
9817 | ||
9818 | or else | |
9819 | (Is_Entity_Name (R) | |
9820 | and then Ekind (Entity (R)) = E_Constant | |
9821 | and then Nkind (L) = N_Type_Conversion | |
9822 | and then Is_Entity_Name (Expression (L)) | |
c84700e7 ES |
9823 | and then Entity (R) = Entity (Expression (L))) |
9824 | ||
9825 | or else | |
9826 | (Is_Entity_Name (L) | |
9827 | and then Is_Entity_Name (R) | |
9828 | and then Entity (L) = Entity (R) | |
9829 | and then Ekind (Entity (L)) = E_In_Parameter | |
9830 | and then Inside_Init_Proc); | |
70482933 RK |
9831 | end Same_Bounds; |
9832 | ||
9833 | -- Start of processing for Selected_Length_Checks | |
9834 | ||
9835 | begin | |
66340e0e | 9836 | -- Checks will be applied only when generating code |
27bb7941 | 9837 | |
66340e0e | 9838 | if not Expander_Active then |
70482933 RK |
9839 | return Ret_Result; |
9840 | end if; | |
9841 | ||
9842 | if Target_Typ = Any_Type | |
9843 | or else Target_Typ = Any_Composite | |
9844 | or else Raises_Constraint_Error (Ck_Node) | |
9845 | then | |
9846 | return Ret_Result; | |
9847 | end if; | |
9848 | ||
9849 | if No (Wnode) then | |
9850 | Wnode := Ck_Node; | |
9851 | end if; | |
9852 | ||
9853 | T_Typ := Target_Typ; | |
9854 | ||
9855 | if No (Source_Typ) then | |
9856 | S_Typ := Etype (Ck_Node); | |
9857 | else | |
9858 | S_Typ := Source_Typ; | |
9859 | end if; | |
9860 | ||
9861 | if S_Typ = Any_Type or else S_Typ = Any_Composite then | |
9862 | return Ret_Result; | |
9863 | end if; | |
9864 | ||
9865 | if Is_Access_Type (T_Typ) and then Is_Access_Type (S_Typ) then | |
9866 | S_Typ := Designated_Type (S_Typ); | |
9867 | T_Typ := Designated_Type (T_Typ); | |
9868 | Do_Access := True; | |
9869 | ||
939c12d2 | 9870 | -- A simple optimization for the null case |
70482933 | 9871 | |
939c12d2 | 9872 | if Known_Null (Ck_Node) then |
70482933 RK |
9873 | return Ret_Result; |
9874 | end if; | |
9875 | end if; | |
9876 | ||
9877 | if Is_Array_Type (T_Typ) and then Is_Array_Type (S_Typ) then | |
9878 | if Is_Constrained (T_Typ) then | |
9879 | ||
9b16cb57 RD |
9880 | -- The checking code to be generated will freeze the corresponding |
9881 | -- array type. However, we must freeze the type now, so that the | |
9882 | -- freeze node does not appear within the generated if expression, | |
9883 | -- but ahead of it. | |
70482933 RK |
9884 | |
9885 | Freeze_Before (Ck_Node, T_Typ); | |
9886 | ||
9887 | Expr_Actual := Get_Referenced_Object (Ck_Node); | |
86ac5e79 | 9888 | Exptyp := Get_Actual_Subtype (Ck_Node); |
70482933 RK |
9889 | |
9890 | if Is_Access_Type (Exptyp) then | |
9891 | Exptyp := Designated_Type (Exptyp); | |
9892 | end if; | |
9893 | ||
9894 | -- String_Literal case. This needs to be handled specially be- | |
9895 | -- cause no index types are available for string literals. The | |
9896 | -- condition is simply: | |
9897 | ||
9898 | -- T_Typ'Length = string-literal-length | |
9899 | ||
fbf5a39b AC |
9900 | if Nkind (Expr_Actual) = N_String_Literal |
9901 | and then Ekind (Etype (Expr_Actual)) = E_String_Literal_Subtype | |
9902 | then | |
70482933 RK |
9903 | Cond := |
9904 | Make_Op_Ne (Loc, | |
9905 | Left_Opnd => Get_E_Length (T_Typ, 1), | |
9906 | Right_Opnd => | |
9907 | Make_Integer_Literal (Loc, | |
9908 | Intval => | |
9909 | String_Literal_Length (Etype (Expr_Actual)))); | |
9910 | ||
9911 | -- General array case. Here we have a usable actual subtype for | |
9912 | -- the expression, and the condition is built from the two types | |
9913 | -- (Do_Length): | |
9914 | ||
9915 | -- T_Typ'Length /= Exptyp'Length or else | |
9916 | -- T_Typ'Length (2) /= Exptyp'Length (2) or else | |
9917 | -- T_Typ'Length (3) /= Exptyp'Length (3) or else | |
9918 | -- ... | |
9919 | ||
9920 | elsif Is_Constrained (Exptyp) then | |
9921 | declare | |
fbf5a39b AC |
9922 | Ndims : constant Nat := Number_Dimensions (T_Typ); |
9923 | ||
9924 | L_Index : Node_Id; | |
9925 | R_Index : Node_Id; | |
9926 | L_Low : Node_Id; | |
9927 | L_High : Node_Id; | |
9928 | R_Low : Node_Id; | |
9929 | R_High : Node_Id; | |
70482933 RK |
9930 | L_Length : Uint; |
9931 | R_Length : Uint; | |
fbf5a39b | 9932 | Ref_Node : Node_Id; |
70482933 RK |
9933 | |
9934 | begin | |
675d6070 TQ |
9935 | -- At the library level, we need to ensure that the type of |
9936 | -- the object is elaborated before the check itself is | |
9937 | -- emitted. This is only done if the object is in the | |
9938 | -- current compilation unit, otherwise the type is frozen | |
9939 | -- and elaborated in its unit. | |
fbf5a39b AC |
9940 | |
9941 | if Is_Itype (Exptyp) | |
9942 | and then | |
9943 | Ekind (Cunit_Entity (Current_Sem_Unit)) = E_Package | |
9944 | and then | |
9945 | not In_Package_Body (Cunit_Entity (Current_Sem_Unit)) | |
891a6e79 | 9946 | and then In_Open_Scopes (Scope (Exptyp)) |
fbf5a39b AC |
9947 | then |
9948 | Ref_Node := Make_Itype_Reference (Sloc (Ck_Node)); | |
9949 | Set_Itype (Ref_Node, Exptyp); | |
9950 | Insert_Action (Ck_Node, Ref_Node); | |
9951 | end if; | |
9952 | ||
70482933 RK |
9953 | L_Index := First_Index (T_Typ); |
9954 | R_Index := First_Index (Exptyp); | |
9955 | ||
9956 | for Indx in 1 .. Ndims loop | |
9957 | if not (Nkind (L_Index) = N_Raise_Constraint_Error | |
07fc65c4 GB |
9958 | or else |
9959 | Nkind (R_Index) = N_Raise_Constraint_Error) | |
70482933 RK |
9960 | then |
9961 | Get_Index_Bounds (L_Index, L_Low, L_High); | |
9962 | Get_Index_Bounds (R_Index, R_Low, R_High); | |
9963 | ||
9964 | -- Deal with compile time length check. Note that we | |
9965 | -- skip this in the access case, because the access | |
9966 | -- value may be null, so we cannot know statically. | |
9967 | ||
9968 | if not Do_Access | |
9969 | and then Compile_Time_Known_Value (L_Low) | |
9970 | and then Compile_Time_Known_Value (L_High) | |
9971 | and then Compile_Time_Known_Value (R_Low) | |
9972 | and then Compile_Time_Known_Value (R_High) | |
9973 | then | |
9974 | if Expr_Value (L_High) >= Expr_Value (L_Low) then | |
9975 | L_Length := Expr_Value (L_High) - | |
9976 | Expr_Value (L_Low) + 1; | |
9977 | else | |
9978 | L_Length := UI_From_Int (0); | |
9979 | end if; | |
9980 | ||
9981 | if Expr_Value (R_High) >= Expr_Value (R_Low) then | |
9982 | R_Length := Expr_Value (R_High) - | |
9983 | Expr_Value (R_Low) + 1; | |
9984 | else | |
9985 | R_Length := UI_From_Int (0); | |
9986 | end if; | |
9987 | ||
9988 | if L_Length > R_Length then | |
9989 | Add_Check | |
9990 | (Compile_Time_Constraint_Error | |
eb6b9c9b GD |
9991 | (Wnode, "too few elements for}??", T_Typ, |
9992 | Extra_Msg => Length_Mismatch_Info_Message | |
9993 | (L_Length, R_Length))); | |
70482933 | 9994 | |
9fe696a3 | 9995 | elsif L_Length < R_Length then |
70482933 RK |
9996 | Add_Check |
9997 | (Compile_Time_Constraint_Error | |
eb6b9c9b GD |
9998 | (Wnode, "too many elements for}??", T_Typ, |
9999 | Extra_Msg => Length_Mismatch_Info_Message | |
10000 | (L_Length, R_Length))); | |
70482933 RK |
10001 | end if; |
10002 | ||
10003 | -- The comparison for an individual index subtype | |
10004 | -- is omitted if the corresponding index subtypes | |
10005 | -- statically match, since the result is known to | |
10006 | -- be true. Note that this test is worth while even | |
10007 | -- though we do static evaluation, because non-static | |
10008 | -- subtypes can statically match. | |
10009 | ||
10010 | elsif not | |
10011 | Subtypes_Statically_Match | |
10012 | (Etype (L_Index), Etype (R_Index)) | |
10013 | ||
10014 | and then not | |
10015 | (Same_Bounds (L_Low, R_Low) | |
10016 | and then Same_Bounds (L_High, R_High)) | |
10017 | then | |
10018 | Evolve_Or_Else | |
10019 | (Cond, Length_E_Cond (Exptyp, T_Typ, Indx)); | |
10020 | end if; | |
10021 | ||
10022 | Next (L_Index); | |
10023 | Next (R_Index); | |
10024 | end if; | |
10025 | end loop; | |
10026 | end; | |
10027 | ||
10028 | -- Handle cases where we do not get a usable actual subtype that | |
10029 | -- is constrained. This happens for example in the function call | |
10030 | -- and explicit dereference cases. In these cases, we have to get | |
10031 | -- the length or range from the expression itself, making sure we | |
10032 | -- do not evaluate it more than once. | |
10033 | ||
10034 | -- Here Ck_Node is the original expression, or more properly the | |
675d6070 TQ |
10035 | -- result of applying Duplicate_Expr to the original tree, forcing |
10036 | -- the result to be a name. | |
70482933 RK |
10037 | |
10038 | else | |
10039 | declare | |
fbf5a39b | 10040 | Ndims : constant Nat := Number_Dimensions (T_Typ); |
70482933 RK |
10041 | |
10042 | begin | |
10043 | -- Build the condition for the explicit dereference case | |
10044 | ||
10045 | for Indx in 1 .. Ndims loop | |
10046 | Evolve_Or_Else | |
10047 | (Cond, Length_N_Cond (Ck_Node, T_Typ, Indx)); | |
10048 | end loop; | |
10049 | end; | |
10050 | end if; | |
10051 | end if; | |
10052 | end if; | |
10053 | ||
10054 | -- Construct the test and insert into the tree | |
10055 | ||
10056 | if Present (Cond) then | |
10057 | if Do_Access then | |
10058 | Cond := Guard_Access (Cond, Loc, Ck_Node); | |
10059 | end if; | |
10060 | ||
07fc65c4 GB |
10061 | Add_Check |
10062 | (Make_Raise_Constraint_Error (Loc, | |
10063 | Condition => Cond, | |
10064 | Reason => CE_Length_Check_Failed)); | |
70482933 RK |
10065 | end if; |
10066 | ||
10067 | return Ret_Result; | |
70482933 RK |
10068 | end Selected_Length_Checks; |
10069 | ||
10070 | --------------------------- | |
10071 | -- Selected_Range_Checks -- | |
10072 | --------------------------- | |
10073 | ||
10074 | function Selected_Range_Checks | |
10075 | (Ck_Node : Node_Id; | |
10076 | Target_Typ : Entity_Id; | |
10077 | Source_Typ : Entity_Id; | |
6b6fcd3e | 10078 | Warn_Node : Node_Id) return Check_Result |
70482933 RK |
10079 | is |
10080 | Loc : constant Source_Ptr := Sloc (Ck_Node); | |
10081 | S_Typ : Entity_Id; | |
10082 | T_Typ : Entity_Id; | |
10083 | Expr_Actual : Node_Id; | |
10084 | Exptyp : Entity_Id; | |
10085 | Cond : Node_Id := Empty; | |
10086 | Do_Access : Boolean := False; | |
10087 | Wnode : Node_Id := Warn_Node; | |
10088 | Ret_Result : Check_Result := (Empty, Empty); | |
dcd5fd67 | 10089 | Num_Checks : Natural := 0; |
70482933 RK |
10090 | |
10091 | procedure Add_Check (N : Node_Id); | |
10092 | -- Adds the action given to Ret_Result if N is non-Empty | |
10093 | ||
10094 | function Discrete_Range_Cond | |
10095 | (Expr : Node_Id; | |
6b6fcd3e | 10096 | Typ : Entity_Id) return Node_Id; |
70482933 RK |
10097 | -- Returns expression to compute: |
10098 | -- Low_Bound (Expr) < Typ'First | |
10099 | -- or else | |
10100 | -- High_Bound (Expr) > Typ'Last | |
10101 | ||
10102 | function Discrete_Expr_Cond | |
10103 | (Expr : Node_Id; | |
6b6fcd3e | 10104 | Typ : Entity_Id) return Node_Id; |
70482933 RK |
10105 | -- Returns expression to compute: |
10106 | -- Expr < Typ'First | |
10107 | -- or else | |
10108 | -- Expr > Typ'Last | |
10109 | ||
10110 | function Get_E_First_Or_Last | |
5a153b27 AC |
10111 | (Loc : Source_Ptr; |
10112 | E : Entity_Id; | |
70482933 | 10113 | Indx : Nat; |
6b6fcd3e | 10114 | Nam : Name_Id) return Node_Id; |
a548f9ff | 10115 | -- Returns an attribute reference |
70482933 | 10116 | -- E'First or E'Last |
a548f9ff | 10117 | -- with a source location of Loc. |
6ca9ec9c | 10118 | -- |
a548f9ff TQ |
10119 | -- Nam is Name_First or Name_Last, according to which attribute is |
10120 | -- desired. If Indx is non-zero, it is passed as a literal in the | |
10121 | -- Expressions of the attribute reference (identifying the desired | |
10122 | -- array dimension). | |
70482933 RK |
10123 | |
10124 | function Get_N_First (N : Node_Id; Indx : Nat) return Node_Id; | |
10125 | function Get_N_Last (N : Node_Id; Indx : Nat) return Node_Id; | |
10126 | -- Returns expression to compute: | |
fbf5a39b | 10127 | -- N'First or N'Last using Duplicate_Subexpr_No_Checks |
70482933 RK |
10128 | |
10129 | function Range_E_Cond | |
10130 | (Exptyp : Entity_Id; | |
10131 | Typ : Entity_Id; | |
10132 | Indx : Nat) | |
10133 | return Node_Id; | |
10134 | -- Returns expression to compute: | |
10135 | -- Exptyp'First < Typ'First or else Exptyp'Last > Typ'Last | |
10136 | ||
10137 | function Range_Equal_E_Cond | |
10138 | (Exptyp : Entity_Id; | |
10139 | Typ : Entity_Id; | |
6b6fcd3e | 10140 | Indx : Nat) return Node_Id; |
70482933 RK |
10141 | -- Returns expression to compute: |
10142 | -- Exptyp'First /= Typ'First or else Exptyp'Last /= Typ'Last | |
10143 | ||
10144 | function Range_N_Cond | |
10145 | (Expr : Node_Id; | |
10146 | Typ : Entity_Id; | |
6b6fcd3e | 10147 | Indx : Nat) return Node_Id; |
70482933 RK |
10148 | -- Return expression to compute: |
10149 | -- Expr'First < Typ'First or else Expr'Last > Typ'Last | |
10150 | ||
10151 | --------------- | |
10152 | -- Add_Check -- | |
10153 | --------------- | |
10154 | ||
10155 | procedure Add_Check (N : Node_Id) is | |
10156 | begin | |
10157 | if Present (N) then | |
10158 | ||
10159 | -- For now, ignore attempt to place more than 2 checks ??? | |
10160 | ||
10161 | if Num_Checks = 2 then | |
10162 | return; | |
10163 | end if; | |
10164 | ||
10165 | pragma Assert (Num_Checks <= 1); | |
10166 | Num_Checks := Num_Checks + 1; | |
10167 | Ret_Result (Num_Checks) := N; | |
10168 | end if; | |
10169 | end Add_Check; | |
10170 | ||
10171 | ------------------------- | |
10172 | -- Discrete_Expr_Cond -- | |
10173 | ------------------------- | |
10174 | ||
10175 | function Discrete_Expr_Cond | |
10176 | (Expr : Node_Id; | |
6b6fcd3e | 10177 | Typ : Entity_Id) return Node_Id |
70482933 RK |
10178 | is |
10179 | begin | |
10180 | return | |
10181 | Make_Or_Else (Loc, | |
10182 | Left_Opnd => | |
10183 | Make_Op_Lt (Loc, | |
10184 | Left_Opnd => | |
fbf5a39b AC |
10185 | Convert_To (Base_Type (Typ), |
10186 | Duplicate_Subexpr_No_Checks (Expr)), | |
70482933 RK |
10187 | Right_Opnd => |
10188 | Convert_To (Base_Type (Typ), | |
5a153b27 | 10189 | Get_E_First_Or_Last (Loc, Typ, 0, Name_First))), |
70482933 RK |
10190 | |
10191 | Right_Opnd => | |
10192 | Make_Op_Gt (Loc, | |
10193 | Left_Opnd => | |
fbf5a39b AC |
10194 | Convert_To (Base_Type (Typ), |
10195 | Duplicate_Subexpr_No_Checks (Expr)), | |
70482933 RK |
10196 | Right_Opnd => |
10197 | Convert_To | |
10198 | (Base_Type (Typ), | |
5a153b27 | 10199 | Get_E_First_Or_Last (Loc, Typ, 0, Name_Last)))); |
70482933 RK |
10200 | end Discrete_Expr_Cond; |
10201 | ||
10202 | ------------------------- | |
10203 | -- Discrete_Range_Cond -- | |
10204 | ------------------------- | |
10205 | ||
10206 | function Discrete_Range_Cond | |
10207 | (Expr : Node_Id; | |
6b6fcd3e | 10208 | Typ : Entity_Id) return Node_Id |
70482933 RK |
10209 | is |
10210 | LB : Node_Id := Low_Bound (Expr); | |
10211 | HB : Node_Id := High_Bound (Expr); | |
10212 | ||
10213 | Left_Opnd : Node_Id; | |
10214 | Right_Opnd : Node_Id; | |
10215 | ||
10216 | begin | |
10217 | if Nkind (LB) = N_Identifier | |
675d6070 TQ |
10218 | and then Ekind (Entity (LB)) = E_Discriminant |
10219 | then | |
70482933 RK |
10220 | LB := New_Occurrence_Of (Discriminal (Entity (LB)), Loc); |
10221 | end if; | |
10222 | ||
70482933 RK |
10223 | Left_Opnd := |
10224 | Make_Op_Lt (Loc, | |
10225 | Left_Opnd => | |
10226 | Convert_To | |
fbf5a39b | 10227 | (Base_Type (Typ), Duplicate_Subexpr_No_Checks (LB)), |
70482933 RK |
10228 | |
10229 | Right_Opnd => | |
10230 | Convert_To | |
5a153b27 AC |
10231 | (Base_Type (Typ), |
10232 | Get_E_First_Or_Last (Loc, Typ, 0, Name_First))); | |
70482933 | 10233 | |
b3f96dc1 AC |
10234 | if Nkind (HB) = N_Identifier |
10235 | and then Ekind (Entity (HB)) = E_Discriminant | |
70482933 | 10236 | then |
b3f96dc1 | 10237 | HB := New_Occurrence_Of (Discriminal (Entity (HB)), Loc); |
70482933 RK |
10238 | end if; |
10239 | ||
10240 | Right_Opnd := | |
10241 | Make_Op_Gt (Loc, | |
10242 | Left_Opnd => | |
10243 | Convert_To | |
fbf5a39b | 10244 | (Base_Type (Typ), Duplicate_Subexpr_No_Checks (HB)), |
70482933 RK |
10245 | |
10246 | Right_Opnd => | |
10247 | Convert_To | |
10248 | (Base_Type (Typ), | |
5a153b27 | 10249 | Get_E_First_Or_Last (Loc, Typ, 0, Name_Last))); |
70482933 RK |
10250 | |
10251 | return Make_Or_Else (Loc, Left_Opnd, Right_Opnd); | |
10252 | end Discrete_Range_Cond; | |
10253 | ||
10254 | ------------------------- | |
10255 | -- Get_E_First_Or_Last -- | |
10256 | ------------------------- | |
10257 | ||
10258 | function Get_E_First_Or_Last | |
5a153b27 AC |
10259 | (Loc : Source_Ptr; |
10260 | E : Entity_Id; | |
70482933 | 10261 | Indx : Nat; |
6b6fcd3e | 10262 | Nam : Name_Id) return Node_Id |
70482933 | 10263 | is |
5a153b27 | 10264 | Exprs : List_Id; |
70482933 | 10265 | begin |
5a153b27 AC |
10266 | if Indx > 0 then |
10267 | Exprs := New_List (Make_Integer_Literal (Loc, UI_From_Int (Indx))); | |
70482933 | 10268 | else |
5a153b27 | 10269 | Exprs := No_List; |
70482933 RK |
10270 | end if; |
10271 | ||
5a153b27 AC |
10272 | return Make_Attribute_Reference (Loc, |
10273 | Prefix => New_Occurrence_Of (E, Loc), | |
10274 | Attribute_Name => Nam, | |
10275 | Expressions => Exprs); | |
70482933 RK |
10276 | end Get_E_First_Or_Last; |
10277 | ||
10278 | ----------------- | |
10279 | -- Get_N_First -- | |
10280 | ----------------- | |
10281 | ||
10282 | function Get_N_First (N : Node_Id; Indx : Nat) return Node_Id is | |
10283 | begin | |
10284 | return | |
10285 | Make_Attribute_Reference (Loc, | |
10286 | Attribute_Name => Name_First, | |
10287 | Prefix => | |
fbf5a39b | 10288 | Duplicate_Subexpr_No_Checks (N, Name_Req => True), |
70482933 RK |
10289 | Expressions => New_List ( |
10290 | Make_Integer_Literal (Loc, Indx))); | |
70482933 RK |
10291 | end Get_N_First; |
10292 | ||
10293 | ---------------- | |
10294 | -- Get_N_Last -- | |
10295 | ---------------- | |
10296 | ||
10297 | function Get_N_Last (N : Node_Id; Indx : Nat) return Node_Id is | |
10298 | begin | |
10299 | return | |
10300 | Make_Attribute_Reference (Loc, | |
10301 | Attribute_Name => Name_Last, | |
10302 | Prefix => | |
fbf5a39b | 10303 | Duplicate_Subexpr_No_Checks (N, Name_Req => True), |
70482933 RK |
10304 | Expressions => New_List ( |
10305 | Make_Integer_Literal (Loc, Indx))); | |
70482933 RK |
10306 | end Get_N_Last; |
10307 | ||
10308 | ------------------ | |
10309 | -- Range_E_Cond -- | |
10310 | ------------------ | |
10311 | ||
10312 | function Range_E_Cond | |
10313 | (Exptyp : Entity_Id; | |
10314 | Typ : Entity_Id; | |
6b6fcd3e | 10315 | Indx : Nat) return Node_Id |
70482933 RK |
10316 | is |
10317 | begin | |
10318 | return | |
10319 | Make_Or_Else (Loc, | |
10320 | Left_Opnd => | |
10321 | Make_Op_Lt (Loc, | |
5a153b27 AC |
10322 | Left_Opnd => |
10323 | Get_E_First_Or_Last (Loc, Exptyp, Indx, Name_First), | |
10324 | Right_Opnd => | |
10325 | Get_E_First_Or_Last (Loc, Typ, Indx, Name_First)), | |
70482933 RK |
10326 | |
10327 | Right_Opnd => | |
10328 | Make_Op_Gt (Loc, | |
5a153b27 AC |
10329 | Left_Opnd => |
10330 | Get_E_First_Or_Last (Loc, Exptyp, Indx, Name_Last), | |
10331 | Right_Opnd => | |
10332 | Get_E_First_Or_Last (Loc, Typ, Indx, Name_Last))); | |
70482933 RK |
10333 | end Range_E_Cond; |
10334 | ||
10335 | ------------------------ | |
10336 | -- Range_Equal_E_Cond -- | |
10337 | ------------------------ | |
10338 | ||
10339 | function Range_Equal_E_Cond | |
10340 | (Exptyp : Entity_Id; | |
10341 | Typ : Entity_Id; | |
6b6fcd3e | 10342 | Indx : Nat) return Node_Id |
70482933 RK |
10343 | is |
10344 | begin | |
10345 | return | |
10346 | Make_Or_Else (Loc, | |
10347 | Left_Opnd => | |
10348 | Make_Op_Ne (Loc, | |
5a153b27 AC |
10349 | Left_Opnd => |
10350 | Get_E_First_Or_Last (Loc, Exptyp, Indx, Name_First), | |
10351 | Right_Opnd => | |
10352 | Get_E_First_Or_Last (Loc, Typ, Indx, Name_First)), | |
10353 | ||
70482933 RK |
10354 | Right_Opnd => |
10355 | Make_Op_Ne (Loc, | |
5a153b27 AC |
10356 | Left_Opnd => |
10357 | Get_E_First_Or_Last (Loc, Exptyp, Indx, Name_Last), | |
10358 | Right_Opnd => | |
10359 | Get_E_First_Or_Last (Loc, Typ, Indx, Name_Last))); | |
70482933 RK |
10360 | end Range_Equal_E_Cond; |
10361 | ||
10362 | ------------------ | |
10363 | -- Range_N_Cond -- | |
10364 | ------------------ | |
10365 | ||
10366 | function Range_N_Cond | |
10367 | (Expr : Node_Id; | |
10368 | Typ : Entity_Id; | |
6b6fcd3e | 10369 | Indx : Nat) return Node_Id |
70482933 RK |
10370 | is |
10371 | begin | |
10372 | return | |
10373 | Make_Or_Else (Loc, | |
10374 | Left_Opnd => | |
10375 | Make_Op_Lt (Loc, | |
5a153b27 AC |
10376 | Left_Opnd => |
10377 | Get_N_First (Expr, Indx), | |
10378 | Right_Opnd => | |
10379 | Get_E_First_Or_Last (Loc, Typ, Indx, Name_First)), | |
70482933 RK |
10380 | |
10381 | Right_Opnd => | |
10382 | Make_Op_Gt (Loc, | |
5a153b27 AC |
10383 | Left_Opnd => |
10384 | Get_N_Last (Expr, Indx), | |
10385 | Right_Opnd => | |
10386 | Get_E_First_Or_Last (Loc, Typ, Indx, Name_Last))); | |
70482933 RK |
10387 | end Range_N_Cond; |
10388 | ||
10389 | -- Start of processing for Selected_Range_Checks | |
10390 | ||
10391 | begin | |
27bb7941 AC |
10392 | -- Checks will be applied only when generating code. In GNATprove mode, |
10393 | -- we do not apply the checks, but we still call Selected_Range_Checks | |
10394 | -- to possibly issue errors on SPARK code when a run-time error can be | |
10395 | -- detected at compile time. | |
10396 | ||
10397 | if not Expander_Active and not GNATprove_Mode then | |
70482933 RK |
10398 | return Ret_Result; |
10399 | end if; | |
10400 | ||
10401 | if Target_Typ = Any_Type | |
10402 | or else Target_Typ = Any_Composite | |
10403 | or else Raises_Constraint_Error (Ck_Node) | |
10404 | then | |
10405 | return Ret_Result; | |
10406 | end if; | |
10407 | ||
10408 | if No (Wnode) then | |
10409 | Wnode := Ck_Node; | |
10410 | end if; | |
10411 | ||
10412 | T_Typ := Target_Typ; | |
10413 | ||
10414 | if No (Source_Typ) then | |
10415 | S_Typ := Etype (Ck_Node); | |
10416 | else | |
10417 | S_Typ := Source_Typ; | |
10418 | end if; | |
10419 | ||
10420 | if S_Typ = Any_Type or else S_Typ = Any_Composite then | |
10421 | return Ret_Result; | |
10422 | end if; | |
10423 | ||
10424 | -- The order of evaluating T_Typ before S_Typ seems to be critical | |
10425 | -- because S_Typ can be derived from Etype (Ck_Node), if it's not passed | |
10426 | -- in, and since Node can be an N_Range node, it might be invalid. | |
10427 | -- Should there be an assert check somewhere for taking the Etype of | |
10428 | -- an N_Range node ??? | |
10429 | ||
10430 | if Is_Access_Type (T_Typ) and then Is_Access_Type (S_Typ) then | |
10431 | S_Typ := Designated_Type (S_Typ); | |
10432 | T_Typ := Designated_Type (T_Typ); | |
10433 | Do_Access := True; | |
10434 | ||
939c12d2 | 10435 | -- A simple optimization for the null case |
70482933 | 10436 | |
939c12d2 | 10437 | if Known_Null (Ck_Node) then |
70482933 RK |
10438 | return Ret_Result; |
10439 | end if; | |
10440 | end if; | |
10441 | ||
10442 | -- For an N_Range Node, check for a null range and then if not | |
10443 | -- null generate a range check action. | |
10444 | ||
10445 | if Nkind (Ck_Node) = N_Range then | |
10446 | ||
10447 | -- There's no point in checking a range against itself | |
10448 | ||
10449 | if Ck_Node = Scalar_Range (T_Typ) then | |
10450 | return Ret_Result; | |
10451 | end if; | |
10452 | ||
10453 | declare | |
10454 | T_LB : constant Node_Id := Type_Low_Bound (T_Typ); | |
10455 | T_HB : constant Node_Id := Type_High_Bound (T_Typ); | |
10475800 EB |
10456 | Known_T_LB : constant Boolean := Compile_Time_Known_Value (T_LB); |
10457 | Known_T_HB : constant Boolean := Compile_Time_Known_Value (T_HB); | |
70482933 | 10458 | |
10475800 EB |
10459 | LB : Node_Id := Low_Bound (Ck_Node); |
10460 | HB : Node_Id := High_Bound (Ck_Node); | |
e49de265 BD |
10461 | Known_LB : Boolean := False; |
10462 | Known_HB : Boolean := False; | |
10475800 EB |
10463 | |
10464 | Null_Range : Boolean; | |
70482933 RK |
10465 | Out_Of_Range_L : Boolean; |
10466 | Out_Of_Range_H : Boolean; | |
10467 | ||
10468 | begin | |
10475800 EB |
10469 | -- Compute what is known at compile time |
10470 | ||
10471 | if Known_T_LB and Known_T_HB then | |
10472 | if Compile_Time_Known_Value (LB) then | |
10473 | Known_LB := True; | |
10474 | ||
10475 | -- There's no point in checking that a bound is within its | |
10476 | -- own range so pretend that it is known in this case. First | |
10477 | -- deal with low bound. | |
10478 | ||
10479 | elsif Ekind (Etype (LB)) = E_Signed_Integer_Subtype | |
10480 | and then Scalar_Range (Etype (LB)) = Scalar_Range (T_Typ) | |
10481 | then | |
10482 | LB := T_LB; | |
10483 | Known_LB := True; | |
10475800 EB |
10484 | end if; |
10485 | ||
10486 | -- Likewise for the high bound | |
10487 | ||
10488 | if Compile_Time_Known_Value (HB) then | |
10489 | Known_HB := True; | |
10490 | ||
10491 | elsif Ekind (Etype (HB)) = E_Signed_Integer_Subtype | |
10492 | and then Scalar_Range (Etype (HB)) = Scalar_Range (T_Typ) | |
10493 | then | |
10494 | HB := T_HB; | |
10495 | Known_HB := True; | |
10475800 EB |
10496 | end if; |
10497 | end if; | |
10498 | ||
10499 | -- Check for case where everything is static and we can do the | |
10500 | -- check at compile time. This is skipped if we have an access | |
10501 | -- type, since the access value may be null. | |
10502 | ||
10503 | -- ??? This code can be improved since you only need to know that | |
10504 | -- the two respective bounds (LB & T_LB or HB & T_HB) are known at | |
10505 | -- compile time to emit pertinent messages. | |
10506 | ||
10507 | if Known_T_LB and Known_T_HB and Known_LB and Known_HB | |
10508 | and not Do_Access | |
70482933 RK |
10509 | then |
10510 | -- Floating-point case | |
10511 | ||
10512 | if Is_Floating_Point_Type (S_Typ) then | |
10513 | Null_Range := Expr_Value_R (HB) < Expr_Value_R (LB); | |
10514 | Out_Of_Range_L := | |
10515 | (Expr_Value_R (LB) < Expr_Value_R (T_LB)) | |
10475800 | 10516 | or else |
70482933 RK |
10517 | (Expr_Value_R (LB) > Expr_Value_R (T_HB)); |
10518 | ||
10519 | Out_Of_Range_H := | |
10520 | (Expr_Value_R (HB) > Expr_Value_R (T_HB)) | |
10475800 | 10521 | or else |
70482933 RK |
10522 | (Expr_Value_R (HB) < Expr_Value_R (T_LB)); |
10523 | ||
10524 | -- Fixed or discrete type case | |
10525 | ||
10526 | else | |
10527 | Null_Range := Expr_Value (HB) < Expr_Value (LB); | |
10528 | Out_Of_Range_L := | |
10529 | (Expr_Value (LB) < Expr_Value (T_LB)) | |
10475800 | 10530 | or else |
70482933 RK |
10531 | (Expr_Value (LB) > Expr_Value (T_HB)); |
10532 | ||
10533 | Out_Of_Range_H := | |
10534 | (Expr_Value (HB) > Expr_Value (T_HB)) | |
10475800 | 10535 | or else |
70482933 RK |
10536 | (Expr_Value (HB) < Expr_Value (T_LB)); |
10537 | end if; | |
10538 | ||
10539 | if not Null_Range then | |
10540 | if Out_Of_Range_L then | |
10541 | if No (Warn_Node) then | |
10542 | Add_Check | |
10543 | (Compile_Time_Constraint_Error | |
10544 | (Low_Bound (Ck_Node), | |
685bc70f | 10545 | "static value out of range of}??", T_Typ)); |
70482933 RK |
10546 | |
10547 | else | |
10548 | Add_Check | |
10549 | (Compile_Time_Constraint_Error | |
10550 | (Wnode, | |
685bc70f | 10551 | "static range out of bounds of}??", T_Typ)); |
70482933 RK |
10552 | end if; |
10553 | end if; | |
10554 | ||
10555 | if Out_Of_Range_H then | |
10556 | if No (Warn_Node) then | |
10557 | Add_Check | |
10558 | (Compile_Time_Constraint_Error | |
10559 | (High_Bound (Ck_Node), | |
685bc70f | 10560 | "static value out of range of}??", T_Typ)); |
70482933 RK |
10561 | |
10562 | else | |
10563 | Add_Check | |
10564 | (Compile_Time_Constraint_Error | |
10565 | (Wnode, | |
685bc70f | 10566 | "static range out of bounds of}??", T_Typ)); |
70482933 RK |
10567 | end if; |
10568 | end if; | |
70482933 RK |
10569 | end if; |
10570 | ||
10571 | else | |
10572 | declare | |
10573 | LB : Node_Id := Low_Bound (Ck_Node); | |
10574 | HB : Node_Id := High_Bound (Ck_Node); | |
10575 | ||
10576 | begin | |
675d6070 TQ |
10577 | -- If either bound is a discriminant and we are within the |
10578 | -- record declaration, it is a use of the discriminant in a | |
10579 | -- constraint of a component, and nothing can be checked | |
10580 | -- here. The check will be emitted within the init proc. | |
10581 | -- Before then, the discriminal has no real meaning. | |
10582 | -- Similarly, if the entity is a discriminal, there is no | |
10583 | -- check to perform yet. | |
10584 | ||
10585 | -- The same holds within a discriminated synchronized type, | |
10586 | -- where the discriminant may constrain a component or an | |
10587 | -- entry family. | |
70482933 RK |
10588 | |
10589 | if Nkind (LB) = N_Identifier | |
c064e066 | 10590 | and then Denotes_Discriminant (LB, True) |
70482933 | 10591 | then |
c064e066 RD |
10592 | if Current_Scope = Scope (Entity (LB)) |
10593 | or else Is_Concurrent_Type (Current_Scope) | |
10594 | or else Ekind (Entity (LB)) /= E_Discriminant | |
10595 | then | |
70482933 RK |
10596 | return Ret_Result; |
10597 | else | |
10598 | LB := | |
10599 | New_Occurrence_Of (Discriminal (Entity (LB)), Loc); | |
10600 | end if; | |
10601 | end if; | |
10602 | ||
10603 | if Nkind (HB) = N_Identifier | |
c064e066 | 10604 | and then Denotes_Discriminant (HB, True) |
70482933 | 10605 | then |
c064e066 RD |
10606 | if Current_Scope = Scope (Entity (HB)) |
10607 | or else Is_Concurrent_Type (Current_Scope) | |
10608 | or else Ekind (Entity (HB)) /= E_Discriminant | |
10609 | then | |
70482933 RK |
10610 | return Ret_Result; |
10611 | else | |
10612 | HB := | |
10613 | New_Occurrence_Of (Discriminal (Entity (HB)), Loc); | |
10614 | end if; | |
10615 | end if; | |
10616 | ||
10617 | Cond := Discrete_Range_Cond (Ck_Node, T_Typ); | |
10618 | Set_Paren_Count (Cond, 1); | |
10619 | ||
10620 | Cond := | |
10621 | Make_And_Then (Loc, | |
10622 | Left_Opnd => | |
10623 | Make_Op_Ge (Loc, | |
4c51ff88 AC |
10624 | Left_Opnd => |
10625 | Convert_To (Base_Type (Etype (HB)), | |
10626 | Duplicate_Subexpr_No_Checks (HB)), | |
10627 | Right_Opnd => | |
10628 | Convert_To (Base_Type (Etype (LB)), | |
10629 | Duplicate_Subexpr_No_Checks (LB))), | |
70482933 RK |
10630 | Right_Opnd => Cond); |
10631 | end; | |
70482933 RK |
10632 | end if; |
10633 | end; | |
10634 | ||
10635 | elsif Is_Scalar_Type (S_Typ) then | |
10636 | ||
10637 | -- This somewhat duplicates what Apply_Scalar_Range_Check does, | |
10638 | -- except the above simply sets a flag in the node and lets | |
10639 | -- gigi generate the check base on the Etype of the expression. | |
10640 | -- Sometimes, however we want to do a dynamic check against an | |
10641 | -- arbitrary target type, so we do that here. | |
10642 | ||
10643 | if Ekind (Base_Type (S_Typ)) /= Ekind (Base_Type (T_Typ)) then | |
10644 | Cond := Discrete_Expr_Cond (Ck_Node, T_Typ); | |
10645 | ||
10646 | -- For literals, we can tell if the constraint error will be | |
10647 | -- raised at compile time, so we never need a dynamic check, but | |
10648 | -- if the exception will be raised, then post the usual warning, | |
10649 | -- and replace the literal with a raise constraint error | |
10650 | -- expression. As usual, skip this for access types | |
10651 | ||
637a41a5 | 10652 | elsif Compile_Time_Known_Value (Ck_Node) and then not Do_Access then |
70482933 RK |
10653 | declare |
10654 | LB : constant Node_Id := Type_Low_Bound (T_Typ); | |
10655 | UB : constant Node_Id := Type_High_Bound (T_Typ); | |
10656 | ||
10657 | Out_Of_Range : Boolean; | |
10658 | Static_Bounds : constant Boolean := | |
15f0f591 AC |
10659 | Compile_Time_Known_Value (LB) |
10660 | and Compile_Time_Known_Value (UB); | |
70482933 RK |
10661 | |
10662 | begin | |
10663 | -- Following range tests should use Sem_Eval routine ??? | |
10664 | ||
10665 | if Static_Bounds then | |
10666 | if Is_Floating_Point_Type (S_Typ) then | |
10667 | Out_Of_Range := | |
10668 | (Expr_Value_R (Ck_Node) < Expr_Value_R (LB)) | |
10669 | or else | |
10670 | (Expr_Value_R (Ck_Node) > Expr_Value_R (UB)); | |
10671 | ||
10475800 EB |
10672 | -- Fixed or discrete type |
10673 | ||
10674 | else | |
70482933 RK |
10675 | Out_Of_Range := |
10676 | Expr_Value (Ck_Node) < Expr_Value (LB) | |
10677 | or else | |
10678 | Expr_Value (Ck_Node) > Expr_Value (UB); | |
10679 | end if; | |
10680 | ||
10475800 EB |
10681 | -- Bounds of the type are static and the literal is out of |
10682 | -- range so output a warning message. | |
70482933 RK |
10683 | |
10684 | if Out_Of_Range then | |
10685 | if No (Warn_Node) then | |
10686 | Add_Check | |
10687 | (Compile_Time_Constraint_Error | |
10688 | (Ck_Node, | |
685bc70f | 10689 | "static value out of range of}??", T_Typ)); |
70482933 RK |
10690 | |
10691 | else | |
10692 | Add_Check | |
10693 | (Compile_Time_Constraint_Error | |
10694 | (Wnode, | |
685bc70f | 10695 | "static value out of range of}??", T_Typ)); |
70482933 RK |
10696 | end if; |
10697 | end if; | |
10698 | ||
10699 | else | |
10700 | Cond := Discrete_Expr_Cond (Ck_Node, T_Typ); | |
10701 | end if; | |
10702 | end; | |
10703 | ||
10704 | -- Here for the case of a non-static expression, we need a runtime | |
10705 | -- check unless the source type range is guaranteed to be in the | |
10706 | -- range of the target type. | |
10707 | ||
10708 | else | |
c27f2f15 | 10709 | if not In_Subrange_Of (S_Typ, T_Typ) then |
70482933 RK |
10710 | Cond := Discrete_Expr_Cond (Ck_Node, T_Typ); |
10711 | end if; | |
10712 | end if; | |
10713 | end if; | |
10714 | ||
10715 | if Is_Array_Type (T_Typ) and then Is_Array_Type (S_Typ) then | |
10716 | if Is_Constrained (T_Typ) then | |
10717 | ||
10718 | Expr_Actual := Get_Referenced_Object (Ck_Node); | |
10719 | Exptyp := Get_Actual_Subtype (Expr_Actual); | |
10720 | ||
10721 | if Is_Access_Type (Exptyp) then | |
10722 | Exptyp := Designated_Type (Exptyp); | |
10723 | end if; | |
10724 | ||
10725 | -- String_Literal case. This needs to be handled specially be- | |
10726 | -- cause no index types are available for string literals. The | |
10727 | -- condition is simply: | |
10728 | ||
10729 | -- T_Typ'Length = string-literal-length | |
10730 | ||
10731 | if Nkind (Expr_Actual) = N_String_Literal then | |
10732 | null; | |
10733 | ||
10734 | -- General array case. Here we have a usable actual subtype for | |
10735 | -- the expression, and the condition is built from the two types | |
10736 | ||
10737 | -- T_Typ'First < Exptyp'First or else | |
10738 | -- T_Typ'Last > Exptyp'Last or else | |
10739 | -- T_Typ'First(1) < Exptyp'First(1) or else | |
10740 | -- T_Typ'Last(1) > Exptyp'Last(1) or else | |
10741 | -- ... | |
10742 | ||
10743 | elsif Is_Constrained (Exptyp) then | |
10744 | declare | |
fbf5a39b AC |
10745 | Ndims : constant Nat := Number_Dimensions (T_Typ); |
10746 | ||
70482933 RK |
10747 | L_Index : Node_Id; |
10748 | R_Index : Node_Id; | |
70482933 RK |
10749 | |
10750 | begin | |
10751 | L_Index := First_Index (T_Typ); | |
10752 | R_Index := First_Index (Exptyp); | |
10753 | ||
10754 | for Indx in 1 .. Ndims loop | |
10755 | if not (Nkind (L_Index) = N_Raise_Constraint_Error | |
07fc65c4 GB |
10756 | or else |
10757 | Nkind (R_Index) = N_Raise_Constraint_Error) | |
70482933 | 10758 | then |
70482933 RK |
10759 | -- Deal with compile time length check. Note that we |
10760 | -- skip this in the access case, because the access | |
10761 | -- value may be null, so we cannot know statically. | |
10762 | ||
10763 | if not | |
10764 | Subtypes_Statically_Match | |
10765 | (Etype (L_Index), Etype (R_Index)) | |
10766 | then | |
10767 | -- If the target type is constrained then we | |
10768 | -- have to check for exact equality of bounds | |
10769 | -- (required for qualified expressions). | |
10770 | ||
10771 | if Is_Constrained (T_Typ) then | |
10772 | Evolve_Or_Else | |
10773 | (Cond, | |
10774 | Range_Equal_E_Cond (Exptyp, T_Typ, Indx)); | |
70482933 RK |
10775 | else |
10776 | Evolve_Or_Else | |
10777 | (Cond, Range_E_Cond (Exptyp, T_Typ, Indx)); | |
10778 | end if; | |
10779 | end if; | |
10780 | ||
10781 | Next (L_Index); | |
10782 | Next (R_Index); | |
70482933 RK |
10783 | end if; |
10784 | end loop; | |
10785 | end; | |
10786 | ||
10787 | -- Handle cases where we do not get a usable actual subtype that | |
10788 | -- is constrained. This happens for example in the function call | |
10789 | -- and explicit dereference cases. In these cases, we have to get | |
10790 | -- the length or range from the expression itself, making sure we | |
10791 | -- do not evaluate it more than once. | |
10792 | ||
10793 | -- Here Ck_Node is the original expression, or more properly the | |
10794 | -- result of applying Duplicate_Expr to the original tree, | |
10795 | -- forcing the result to be a name. | |
10796 | ||
10797 | else | |
10798 | declare | |
fbf5a39b | 10799 | Ndims : constant Nat := Number_Dimensions (T_Typ); |
70482933 RK |
10800 | |
10801 | begin | |
10802 | -- Build the condition for the explicit dereference case | |
10803 | ||
10804 | for Indx in 1 .. Ndims loop | |
10805 | Evolve_Or_Else | |
10806 | (Cond, Range_N_Cond (Ck_Node, T_Typ, Indx)); | |
10807 | end loop; | |
10808 | end; | |
70482933 RK |
10809 | end if; |
10810 | ||
10811 | else | |
675d6070 TQ |
10812 | -- For a conversion to an unconstrained array type, generate an |
10813 | -- Action to check that the bounds of the source value are within | |
10814 | -- the constraints imposed by the target type (RM 4.6(38)). No | |
10815 | -- check is needed for a conversion to an access to unconstrained | |
10816 | -- array type, as 4.6(24.15/2) requires the designated subtypes | |
10817 | -- of the two access types to statically match. | |
10818 | ||
10819 | if Nkind (Parent (Ck_Node)) = N_Type_Conversion | |
10820 | and then not Do_Access | |
10821 | then | |
70482933 RK |
10822 | declare |
10823 | Opnd_Index : Node_Id; | |
10824 | Targ_Index : Node_Id; | |
11b4899f | 10825 | Opnd_Range : Node_Id; |
70482933 RK |
10826 | |
10827 | begin | |
675d6070 | 10828 | Opnd_Index := First_Index (Get_Actual_Subtype (Ck_Node)); |
70482933 | 10829 | Targ_Index := First_Index (T_Typ); |
11b4899f JM |
10830 | while Present (Opnd_Index) loop |
10831 | ||
10832 | -- If the index is a range, use its bounds. If it is an | |
10833 | -- entity (as will be the case if it is a named subtype | |
10834 | -- or an itype created for a slice) retrieve its range. | |
10835 | ||
10836 | if Is_Entity_Name (Opnd_Index) | |
10837 | and then Is_Type (Entity (Opnd_Index)) | |
10838 | then | |
10839 | Opnd_Range := Scalar_Range (Entity (Opnd_Index)); | |
10840 | else | |
10841 | Opnd_Range := Opnd_Index; | |
10842 | end if; | |
10843 | ||
10844 | if Nkind (Opnd_Range) = N_Range then | |
c800f862 RD |
10845 | if Is_In_Range |
10846 | (Low_Bound (Opnd_Range), Etype (Targ_Index), | |
10847 | Assume_Valid => True) | |
70482933 RK |
10848 | and then |
10849 | Is_In_Range | |
c800f862 RD |
10850 | (High_Bound (Opnd_Range), Etype (Targ_Index), |
10851 | Assume_Valid => True) | |
70482933 RK |
10852 | then |
10853 | null; | |
10854 | ||
675d6070 | 10855 | -- If null range, no check needed |
ddda9d0f | 10856 | |
fbf5a39b | 10857 | elsif |
11b4899f | 10858 | Compile_Time_Known_Value (High_Bound (Opnd_Range)) |
fbf5a39b | 10859 | and then |
11b4899f | 10860 | Compile_Time_Known_Value (Low_Bound (Opnd_Range)) |
fbf5a39b | 10861 | and then |
11b4899f JM |
10862 | Expr_Value (High_Bound (Opnd_Range)) < |
10863 | Expr_Value (Low_Bound (Opnd_Range)) | |
fbf5a39b AC |
10864 | then |
10865 | null; | |
10866 | ||
70482933 | 10867 | elsif Is_Out_Of_Range |
c800f862 RD |
10868 | (Low_Bound (Opnd_Range), Etype (Targ_Index), |
10869 | Assume_Valid => True) | |
70482933 RK |
10870 | or else |
10871 | Is_Out_Of_Range | |
c800f862 RD |
10872 | (High_Bound (Opnd_Range), Etype (Targ_Index), |
10873 | Assume_Valid => True) | |
70482933 RK |
10874 | then |
10875 | Add_Check | |
10876 | (Compile_Time_Constraint_Error | |
685bc70f | 10877 | (Wnode, "value out of range of}??", T_Typ)); |
70482933 RK |
10878 | |
10879 | else | |
10880 | Evolve_Or_Else | |
10881 | (Cond, | |
10882 | Discrete_Range_Cond | |
11b4899f | 10883 | (Opnd_Range, Etype (Targ_Index))); |
70482933 RK |
10884 | end if; |
10885 | end if; | |
10886 | ||
10887 | Next_Index (Opnd_Index); | |
10888 | Next_Index (Targ_Index); | |
10889 | end loop; | |
10890 | end; | |
10891 | end if; | |
10892 | end if; | |
10893 | end if; | |
10894 | ||
10895 | -- Construct the test and insert into the tree | |
10896 | ||
10897 | if Present (Cond) then | |
10898 | if Do_Access then | |
10899 | Cond := Guard_Access (Cond, Loc, Ck_Node); | |
10900 | end if; | |
10901 | ||
07fc65c4 GB |
10902 | Add_Check |
10903 | (Make_Raise_Constraint_Error (Loc, | |
10475800 | 10904 | Condition => Cond, |
af6478c8 | 10905 | Reason => CE_Range_Check_Failed)); |
70482933 RK |
10906 | end if; |
10907 | ||
10908 | return Ret_Result; | |
70482933 RK |
10909 | end Selected_Range_Checks; |
10910 | ||
10911 | ------------------------------- | |
10912 | -- Storage_Checks_Suppressed -- | |
10913 | ------------------------------- | |
10914 | ||
10915 | function Storage_Checks_Suppressed (E : Entity_Id) return Boolean is | |
10916 | begin | |
fbf5a39b AC |
10917 | if Present (E) and then Checks_May_Be_Suppressed (E) then |
10918 | return Is_Check_Suppressed (E, Storage_Check); | |
10919 | else | |
3217f71e | 10920 | return Scope_Suppress.Suppress (Storage_Check); |
fbf5a39b | 10921 | end if; |
70482933 RK |
10922 | end Storage_Checks_Suppressed; |
10923 | ||
10924 | --------------------------- | |
10925 | -- Tag_Checks_Suppressed -- | |
10926 | --------------------------- | |
10927 | ||
10928 | function Tag_Checks_Suppressed (E : Entity_Id) return Boolean is | |
10929 | begin | |
b98e2969 AC |
10930 | if Present (E) |
10931 | and then Checks_May_Be_Suppressed (E) | |
10932 | then | |
10933 | return Is_Check_Suppressed (E, Tag_Check); | |
637a41a5 AC |
10934 | else |
10935 | return Scope_Suppress.Suppress (Tag_Check); | |
fbf5a39b | 10936 | end if; |
70482933 RK |
10937 | end Tag_Checks_Suppressed; |
10938 | ||
aca670a0 AC |
10939 | --------------------------------------- |
10940 | -- Validate_Alignment_Check_Warnings -- | |
10941 | --------------------------------------- | |
10942 | ||
10943 | procedure Validate_Alignment_Check_Warnings is | |
10944 | begin | |
10945 | for J in Alignment_Warnings.First .. Alignment_Warnings.Last loop | |
10946 | declare | |
10947 | AWR : Alignment_Warnings_Record | |
10948 | renames Alignment_Warnings.Table (J); | |
10949 | begin | |
10950 | if Known_Alignment (AWR.E) | |
5c13a04e EB |
10951 | and then ((AWR.A /= No_Uint |
10952 | and then AWR.A mod Alignment (AWR.E) = 0) | |
10953 | or else (Present (AWR.P) | |
10954 | and then Has_Compatible_Alignment | |
10955 | (AWR.E, AWR.P, True) = | |
10956 | Known_Compatible)) | |
aca670a0 AC |
10957 | then |
10958 | Delete_Warning_And_Continuations (AWR.W); | |
10959 | end if; | |
10960 | end; | |
10961 | end loop; | |
10962 | end Validate_Alignment_Check_Warnings; | |
10963 | ||
c064e066 RD |
10964 | -------------------------- |
10965 | -- Validity_Check_Range -- | |
10966 | -------------------------- | |
10967 | ||
2934b84a AC |
10968 | procedure Validity_Check_Range |
10969 | (N : Node_Id; | |
10970 | Related_Id : Entity_Id := Empty) | |
10971 | is | |
c064e066 RD |
10972 | begin |
10973 | if Validity_Checks_On and Validity_Check_Operands then | |
10974 | if Nkind (N) = N_Range then | |
2934b84a AC |
10975 | Ensure_Valid |
10976 | (Expr => Low_Bound (N), | |
10977 | Related_Id => Related_Id, | |
10978 | Is_Low_Bound => True); | |
10979 | ||
10980 | Ensure_Valid | |
10981 | (Expr => High_Bound (N), | |
10982 | Related_Id => Related_Id, | |
10983 | Is_High_Bound => True); | |
c064e066 RD |
10984 | end if; |
10985 | end if; | |
10986 | end Validity_Check_Range; | |
10987 | ||
10988 | -------------------------------- | |
10989 | -- Validity_Checks_Suppressed -- | |
10990 | -------------------------------- | |
10991 | ||
10992 | function Validity_Checks_Suppressed (E : Entity_Id) return Boolean is | |
10993 | begin | |
10994 | if Present (E) and then Checks_May_Be_Suppressed (E) then | |
10995 | return Is_Check_Suppressed (E, Validity_Check); | |
10996 | else | |
3217f71e | 10997 | return Scope_Suppress.Suppress (Validity_Check); |
c064e066 RD |
10998 | end if; |
10999 | end Validity_Checks_Suppressed; | |
11000 | ||
70482933 | 11001 | end Checks; |