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ee6ba406 | 1 | ------------------------------------------------------------------------------ |
2 | -- -- | |
3 | -- GNAT COMPILER COMPONENTS -- | |
4 | -- -- | |
5 | -- C H E C K S -- | |
6 | -- -- | |
7 | -- B o d y -- | |
8 | -- -- | |
86594966 | 9 | -- Copyright (C) 1992-2013, Free Software Foundation, Inc. -- |
ee6ba406 | 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- -- | |
80df182a | 13 | -- ware Foundation; either version 3, or (at your option) any later ver- -- |
ee6ba406 | 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 -- | |
80df182a | 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. -- | |
ee6ba406 | 20 | -- -- |
21 | -- GNAT was originally developed by the GNAT team at New York University. -- | |
e78e8c8e | 22 | -- Extensive contributions were provided by Ada Core Technologies Inc. -- |
ee6ba406 | 23 | -- -- |
24 | ------------------------------------------------------------------------------ | |
25 | ||
26 | with Atree; use Atree; | |
29448168 | 27 | with Casing; use Casing; |
ee6ba406 | 28 | with Debug; use Debug; |
29 | with Einfo; use Einfo; | |
30 | with Errout; use Errout; | |
31 | with Exp_Ch2; use Exp_Ch2; | |
df40eeb0 | 32 | with Exp_Ch4; use Exp_Ch4; |
00c403ee | 33 | with Exp_Ch11; use Exp_Ch11; |
05fcfafb | 34 | with Exp_Pakd; use Exp_Pakd; |
301d5ec3 | 35 | with Exp_Tss; use Exp_Tss; |
ee6ba406 | 36 | with Exp_Util; use Exp_Util; |
37 | with Elists; use Elists; | |
4fb5f0a0 | 38 | with Expander; use Expander; |
5329ca64 | 39 | with Eval_Fat; use Eval_Fat; |
ee6ba406 | 40 | with Freeze; use Freeze; |
9dfe12ae | 41 | with Lib; use Lib; |
ee6ba406 | 42 | with Nlists; use Nlists; |
43 | with Nmake; use Nmake; | |
44 | with Opt; use Opt; | |
9dfe12ae | 45 | with Output; use Output; |
c2b56224 | 46 | with Restrict; use Restrict; |
1e16c51c | 47 | with Rident; use Rident; |
ee6ba406 | 48 | with Rtsfind; use Rtsfind; |
49 | with Sem; use Sem; | |
d60c9ff7 | 50 | with Sem_Aux; use Sem_Aux; |
ee6ba406 | 51 | with Sem_Eval; use Sem_Eval; |
00f91aef | 52 | with Sem_Ch3; use Sem_Ch3; |
9dfe12ae | 53 | with Sem_Ch8; use Sem_Ch8; |
ee6ba406 | 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; | |
9dfe12ae | 58 | with Sinput; use Sinput; |
ee6ba406 | 59 | with Snames; use Snames; |
9dfe12ae | 60 | with Sprint; use Sprint; |
ee6ba406 | 61 | with Stand; use Stand; |
bb569db0 | 62 | with Stringt; use Stringt; |
f15731c4 | 63 | with Targparm; use Targparm; |
ee6ba406 | 64 | with Tbuild; use Tbuild; |
65 | with Ttypes; use Ttypes; | |
66 | with Urealp; use Urealp; | |
67 | with Validsw; use Validsw; | |
68 | ||
69 | package body Checks is | |
70 | ||
71 | -- General note: many of these routines are concerned with generating | |
72 | -- checking code to make sure that constraint error is raised at runtime. | |
73 | -- Clearly this code is only needed if the expander is active, since | |
74 | -- otherwise we will not be generating code or going into the runtime | |
75 | -- execution anyway. | |
76 | ||
77 | -- We therefore disconnect most of these checks if the expander is | |
78 | -- inactive. This has the additional benefit that we do not need to | |
79 | -- worry about the tree being messed up by previous errors (since errors | |
80 | -- turn off expansion anyway). | |
81 | ||
82 | -- There are a few exceptions to the above rule. For instance routines | |
83 | -- such as Apply_Scalar_Range_Check that do not insert any code can be | |
84 | -- safely called even when the Expander is inactive (but Errors_Detected | |
85 | -- is 0). The benefit of executing this code when expansion is off, is | |
86 | -- the ability to emit constraint error warning for static expressions | |
87 | -- even when we are not generating code. | |
88 | ||
20cf157b | 89 | -- The above is modified in gnatprove mode to ensure that proper check |
90 | -- flags are always placed, even if expansion is off. | |
91 | ||
9dfe12ae | 92 | ------------------------------------- |
93 | -- Suppression of Redundant Checks -- | |
94 | ------------------------------------- | |
95 | ||
96 | -- This unit implements a limited circuit for removal of redundant | |
97 | -- checks. The processing is based on a tracing of simple sequential | |
98 | -- flow. For any sequence of statements, we save expressions that are | |
99 | -- marked to be checked, and then if the same expression appears later | |
100 | -- with the same check, then under certain circumstances, the second | |
101 | -- check can be suppressed. | |
102 | ||
103 | -- Basically, we can suppress the check if we know for certain that | |
104 | -- the previous expression has been elaborated (together with its | |
105 | -- check), and we know that the exception frame is the same, and that | |
106 | -- nothing has happened to change the result of the exception. | |
107 | ||
108 | -- Let us examine each of these three conditions in turn to describe | |
109 | -- how we ensure that this condition is met. | |
110 | ||
111 | -- First, we need to know for certain that the previous expression has | |
6fb3c314 | 112 | -- been executed. This is done principally by the mechanism of calling |
9dfe12ae | 113 | -- Conditional_Statements_Begin at the start of any statement sequence |
114 | -- and Conditional_Statements_End at the end. The End call causes all | |
115 | -- checks remembered since the Begin call to be discarded. This does | |
116 | -- miss a few cases, notably the case of a nested BEGIN-END block with | |
117 | -- no exception handlers. But the important thing is to be conservative. | |
118 | -- The other protection is that all checks are discarded if a label | |
119 | -- is encountered, since then the assumption of sequential execution | |
120 | -- is violated, and we don't know enough about the flow. | |
121 | ||
122 | -- Second, we need to know that the exception frame is the same. We | |
123 | -- do this by killing all remembered checks when we enter a new frame. | |
124 | -- Again, that's over-conservative, but generally the cases we can help | |
125 | -- with are pretty local anyway (like the body of a loop for example). | |
126 | ||
127 | -- Third, we must be sure to forget any checks which are no longer valid. | |
128 | -- This is done by two mechanisms, first the Kill_Checks_Variable call is | |
129 | -- used to note any changes to local variables. We only attempt to deal | |
130 | -- with checks involving local variables, so we do not need to worry | |
131 | -- about global variables. Second, a call to any non-global procedure | |
132 | -- causes us to abandon all stored checks, since such a all may affect | |
133 | -- the values of any local variables. | |
134 | ||
135 | -- The following define the data structures used to deal with remembering | |
136 | -- checks so that redundant checks can be eliminated as described above. | |
137 | ||
138 | -- Right now, the only expressions that we deal with are of the form of | |
139 | -- simple local objects (either declared locally, or IN parameters) or | |
140 | -- such objects plus/minus a compile time known constant. We can do | |
141 | -- more later on if it seems worthwhile, but this catches many simple | |
142 | -- cases in practice. | |
143 | ||
144 | -- The following record type reflects a single saved check. An entry | |
145 | -- is made in the stack of saved checks if and only if the expression | |
146 | -- has been elaborated with the indicated checks. | |
147 | ||
148 | type Saved_Check is record | |
149 | Killed : Boolean; | |
150 | -- Set True if entry is killed by Kill_Checks | |
151 | ||
152 | Entity : Entity_Id; | |
153 | -- The entity involved in the expression that is checked | |
154 | ||
155 | Offset : Uint; | |
156 | -- A compile time value indicating the result of adding or | |
157 | -- subtracting a compile time value. This value is to be | |
158 | -- added to the value of the Entity. A value of zero is | |
159 | -- used for the case of a simple entity reference. | |
160 | ||
161 | Check_Type : Character; | |
162 | -- This is set to 'R' for a range check (in which case Target_Type | |
163 | -- is set to the target type for the range check) or to 'O' for an | |
164 | -- overflow check (in which case Target_Type is set to Empty). | |
165 | ||
166 | Target_Type : Entity_Id; | |
167 | -- Used only if Do_Range_Check is set. Records the target type for | |
168 | -- the check. We need this, because a check is a duplicate only if | |
6fb3c314 | 169 | -- it has the same target type (or more accurately one with a |
9dfe12ae | 170 | -- range that is smaller or equal to the stored target type of a |
171 | -- saved check). | |
172 | end record; | |
173 | ||
174 | -- The following table keeps track of saved checks. Rather than use an | |
175 | -- extensible table. We just use a table of fixed size, and we discard | |
176 | -- any saved checks that do not fit. That's very unlikely to happen and | |
177 | -- this is only an optimization in any case. | |
178 | ||
179 | Saved_Checks : array (Int range 1 .. 200) of Saved_Check; | |
180 | -- Array of saved checks | |
181 | ||
182 | Num_Saved_Checks : Nat := 0; | |
183 | -- Number of saved checks | |
184 | ||
185 | -- The following stack keeps track of statement ranges. It is treated | |
186 | -- as a stack. When Conditional_Statements_Begin is called, an entry | |
187 | -- is pushed onto this stack containing the value of Num_Saved_Checks | |
188 | -- at the time of the call. Then when Conditional_Statements_End is | |
189 | -- called, this value is popped off and used to reset Num_Saved_Checks. | |
190 | ||
191 | -- Note: again, this is a fixed length stack with a size that should | |
192 | -- always be fine. If the value of the stack pointer goes above the | |
193 | -- limit, then we just forget all saved checks. | |
194 | ||
195 | Saved_Checks_Stack : array (Int range 1 .. 100) of Nat; | |
196 | Saved_Checks_TOS : Nat := 0; | |
197 | ||
198 | ----------------------- | |
199 | -- Local Subprograms -- | |
200 | ----------------------- | |
ee6ba406 | 201 | |
0df9d43f | 202 | procedure Apply_Arithmetic_Overflow_Strict (N : Node_Id); |
3cce7f32 | 203 | -- Used to apply arithmetic overflow checks for all cases except operators |
691fe9e0 | 204 | -- on signed arithmetic types in MINIMIZED/ELIMINATED case (for which we |
0df9d43f | 205 | -- call Apply_Arithmetic_Overflow_Minimized_Eliminated below). N can be a |
206 | -- signed integer arithmetic operator (but not an if or case expression). | |
207 | -- It is also called for types other than signed integers. | |
3cce7f32 | 208 | |
209 | procedure Apply_Arithmetic_Overflow_Minimized_Eliminated (Op : Node_Id); | |
210 | -- Used to apply arithmetic overflow checks for the case where the overflow | |
0df9d43f | 211 | -- checking mode is MINIMIZED or ELIMINATED and we have a signed integer |
212 | -- arithmetic op (which includes the case of if and case expressions). Note | |
213 | -- that Do_Overflow_Check may or may not be set for node Op. In these modes | |
214 | -- we have work to do even if overflow checking is suppressed. | |
3cce7f32 | 215 | |
2fe22c69 | 216 | procedure Apply_Division_Check |
217 | (N : Node_Id; | |
218 | Rlo : Uint; | |
219 | Rhi : Uint; | |
220 | ROK : Boolean); | |
221 | -- N is an N_Op_Div, N_Op_Rem, or N_Op_Mod node. This routine applies | |
222 | -- division checks as required if the Do_Division_Check flag is set. | |
223 | -- Rlo and Rhi give the possible range of the right operand, these values | |
224 | -- can be referenced and trusted only if ROK is set True. | |
225 | ||
226 | procedure Apply_Float_Conversion_Check | |
227 | (Ck_Node : Node_Id; | |
228 | Target_Typ : Entity_Id); | |
229 | -- The checks on a conversion from a floating-point type to an integer | |
230 | -- type are delicate. They have to be performed before conversion, they | |
231 | -- have to raise an exception when the operand is a NaN, and rounding must | |
232 | -- be taken into account to determine the safe bounds of the operand. | |
233 | ||
ee6ba406 | 234 | procedure Apply_Selected_Length_Checks |
235 | (Ck_Node : Node_Id; | |
236 | Target_Typ : Entity_Id; | |
237 | Source_Typ : Entity_Id; | |
238 | Do_Static : Boolean); | |
239 | -- This is the subprogram that does all the work for Apply_Length_Check | |
240 | -- and Apply_Static_Length_Check. Expr, Target_Typ and Source_Typ are as | |
241 | -- described for the above routines. The Do_Static flag indicates that | |
242 | -- only a static check is to be done. | |
243 | ||
244 | procedure Apply_Selected_Range_Checks | |
245 | (Ck_Node : Node_Id; | |
246 | Target_Typ : Entity_Id; | |
247 | Source_Typ : Entity_Id; | |
248 | Do_Static : Boolean); | |
249 | -- This is the subprogram that does all the work for Apply_Range_Check. | |
250 | -- Expr, Target_Typ and Source_Typ are as described for the above | |
251 | -- routine. The Do_Static flag indicates that only a static check is | |
252 | -- to be done. | |
253 | ||
2af58f67 | 254 | type Check_Type is new Check_Id range Access_Check .. Division_Check; |
13dbf220 | 255 | function Check_Needed (Nod : Node_Id; Check : Check_Type) return Boolean; |
256 | -- This function is used to see if an access or division by zero check is | |
257 | -- needed. The check is to be applied to a single variable appearing in the | |
258 | -- source, and N is the node for the reference. If N is not of this form, | |
259 | -- True is returned with no further processing. If N is of the right form, | |
260 | -- then further processing determines if the given Check is needed. | |
261 | -- | |
262 | -- The particular circuit is to see if we have the case of a check that is | |
263 | -- not needed because it appears in the right operand of a short circuited | |
264 | -- conditional where the left operand guards the check. For example: | |
265 | -- | |
266 | -- if Var = 0 or else Q / Var > 12 then | |
267 | -- ... | |
268 | -- end if; | |
269 | -- | |
270 | -- In this example, the division check is not required. At the same time | |
271 | -- we can issue warnings for suspicious use of non-short-circuited forms, | |
272 | -- such as: | |
273 | -- | |
274 | -- if Var = 0 or Q / Var > 12 then | |
275 | -- ... | |
276 | -- end if; | |
277 | ||
9dfe12ae | 278 | procedure Find_Check |
279 | (Expr : Node_Id; | |
280 | Check_Type : Character; | |
281 | Target_Type : Entity_Id; | |
282 | Entry_OK : out Boolean; | |
283 | Check_Num : out Nat; | |
284 | Ent : out Entity_Id; | |
285 | Ofs : out Uint); | |
286 | -- This routine is used by Enable_Range_Check and Enable_Overflow_Check | |
287 | -- to see if a check is of the form for optimization, and if so, to see | |
288 | -- if it has already been performed. Expr is the expression to check, | |
289 | -- and Check_Type is 'R' for a range check, 'O' for an overflow check. | |
290 | -- Target_Type is the target type for a range check, and Empty for an | |
291 | -- overflow check. If the entry is not of the form for optimization, | |
292 | -- then Entry_OK is set to False, and the remaining out parameters | |
293 | -- are undefined. If the entry is OK, then Ent/Ofs are set to the | |
294 | -- entity and offset from the expression. Check_Num is the number of | |
295 | -- a matching saved entry in Saved_Checks, or zero if no such entry | |
296 | -- is located. | |
297 | ||
ee6ba406 | 298 | function Get_Discriminal (E : Entity_Id; Bound : Node_Id) return Node_Id; |
299 | -- If a discriminal is used in constraining a prival, Return reference | |
300 | -- to the discriminal of the protected body (which renames the parameter | |
301 | -- of the enclosing protected operation). This clumsy transformation is | |
302 | -- needed because privals are created too late and their actual subtypes | |
303 | -- are not available when analysing the bodies of the protected operations. | |
0577b0b1 | 304 | -- This function is called whenever the bound is an entity and the scope |
305 | -- indicates a protected operation. If the bound is an in-parameter of | |
306 | -- a protected operation that is not a prival, the function returns the | |
307 | -- bound itself. | |
ee6ba406 | 308 | -- To be cleaned up??? |
309 | ||
310 | function Guard_Access | |
311 | (Cond : Node_Id; | |
312 | Loc : Source_Ptr; | |
314a23b6 | 313 | Ck_Node : Node_Id) return Node_Id; |
ee6ba406 | 314 | -- In the access type case, guard the test with a test to ensure |
315 | -- that the access value is non-null, since the checks do not | |
316 | -- not apply to null access values. | |
317 | ||
318 | procedure Install_Static_Check (R_Cno : Node_Id; Loc : Source_Ptr); | |
319 | -- Called by Apply_{Length,Range}_Checks to rewrite the tree with the | |
320 | -- Constraint_Error node. | |
321 | ||
3cce7f32 | 322 | function Is_Signed_Integer_Arithmetic_Op (N : Node_Id) return Boolean; |
323 | -- Returns True if node N is for an arithmetic operation with signed | |
0326b4d4 | 324 | -- integer operands. This includes unary and binary operators, and also |
325 | -- if and case expression nodes where the dependent expressions are of | |
326 | -- a signed integer type. These are the kinds of nodes for which special | |
691fe9e0 | 327 | -- handling applies in MINIMIZED or ELIMINATED overflow checking mode. |
3cce7f32 | 328 | |
0577b0b1 | 329 | function Range_Or_Validity_Checks_Suppressed |
330 | (Expr : Node_Id) return Boolean; | |
331 | -- Returns True if either range or validity checks or both are suppressed | |
332 | -- for the type of the given expression, or, if the expression is the name | |
333 | -- of an entity, if these checks are suppressed for the entity. | |
334 | ||
ee6ba406 | 335 | function Selected_Length_Checks |
336 | (Ck_Node : Node_Id; | |
337 | Target_Typ : Entity_Id; | |
338 | Source_Typ : Entity_Id; | |
314a23b6 | 339 | Warn_Node : Node_Id) return Check_Result; |
ee6ba406 | 340 | -- Like Apply_Selected_Length_Checks, except it doesn't modify |
341 | -- anything, just returns a list of nodes as described in the spec of | |
342 | -- this package for the Range_Check function. | |
343 | ||
344 | function Selected_Range_Checks | |
345 | (Ck_Node : Node_Id; | |
346 | Target_Typ : Entity_Id; | |
347 | Source_Typ : Entity_Id; | |
314a23b6 | 348 | Warn_Node : Node_Id) return Check_Result; |
ee6ba406 | 349 | -- Like Apply_Selected_Range_Checks, except it doesn't modify anything, |
350 | -- just returns a list of nodes as described in the spec of this package | |
351 | -- for the Range_Check function. | |
352 | ||
353 | ------------------------------ | |
354 | -- Access_Checks_Suppressed -- | |
355 | ------------------------------ | |
356 | ||
357 | function Access_Checks_Suppressed (E : Entity_Id) return Boolean is | |
358 | begin | |
9dfe12ae | 359 | if Present (E) and then Checks_May_Be_Suppressed (E) then |
360 | return Is_Check_Suppressed (E, Access_Check); | |
361 | else | |
fafc6b97 | 362 | return Scope_Suppress.Suppress (Access_Check); |
9dfe12ae | 363 | end if; |
ee6ba406 | 364 | end Access_Checks_Suppressed; |
365 | ||
366 | ------------------------------------- | |
367 | -- Accessibility_Checks_Suppressed -- | |
368 | ------------------------------------- | |
369 | ||
370 | function Accessibility_Checks_Suppressed (E : Entity_Id) return Boolean is | |
371 | begin | |
9dfe12ae | 372 | if Present (E) and then Checks_May_Be_Suppressed (E) then |
373 | return Is_Check_Suppressed (E, Accessibility_Check); | |
374 | else | |
fafc6b97 | 375 | return Scope_Suppress.Suppress (Accessibility_Check); |
9dfe12ae | 376 | end if; |
ee6ba406 | 377 | end Accessibility_Checks_Suppressed; |
378 | ||
00c403ee | 379 | ----------------------------- |
380 | -- Activate_Division_Check -- | |
381 | ----------------------------- | |
382 | ||
383 | procedure Activate_Division_Check (N : Node_Id) is | |
384 | begin | |
385 | Set_Do_Division_Check (N, True); | |
386 | Possible_Local_Raise (N, Standard_Constraint_Error); | |
387 | end Activate_Division_Check; | |
388 | ||
389 | ----------------------------- | |
390 | -- Activate_Overflow_Check -- | |
391 | ----------------------------- | |
392 | ||
393 | procedure Activate_Overflow_Check (N : Node_Id) is | |
394 | begin | |
d32ceaf3 | 395 | if not Nkind_In (N, N_Op_Rem, N_Op_Mod, N_Op_Plus) then |
396 | Set_Do_Overflow_Check (N, True); | |
397 | Possible_Local_Raise (N, Standard_Constraint_Error); | |
398 | end if; | |
00c403ee | 399 | end Activate_Overflow_Check; |
400 | ||
401 | -------------------------- | |
402 | -- Activate_Range_Check -- | |
403 | -------------------------- | |
404 | ||
405 | procedure Activate_Range_Check (N : Node_Id) is | |
406 | begin | |
407 | Set_Do_Range_Check (N, True); | |
408 | Possible_Local_Raise (N, Standard_Constraint_Error); | |
409 | end Activate_Range_Check; | |
410 | ||
0577b0b1 | 411 | --------------------------------- |
412 | -- Alignment_Checks_Suppressed -- | |
413 | --------------------------------- | |
414 | ||
415 | function Alignment_Checks_Suppressed (E : Entity_Id) return Boolean is | |
416 | begin | |
417 | if Present (E) and then Checks_May_Be_Suppressed (E) then | |
418 | return Is_Check_Suppressed (E, Alignment_Check); | |
419 | else | |
fafc6b97 | 420 | return Scope_Suppress.Suppress (Alignment_Check); |
0577b0b1 | 421 | end if; |
422 | end Alignment_Checks_Suppressed; | |
423 | ||
ee6ba406 | 424 | ------------------------- |
425 | -- Append_Range_Checks -- | |
426 | ------------------------- | |
427 | ||
428 | procedure Append_Range_Checks | |
429 | (Checks : Check_Result; | |
430 | Stmts : List_Id; | |
431 | Suppress_Typ : Entity_Id; | |
432 | Static_Sloc : Source_Ptr; | |
433 | Flag_Node : Node_Id) | |
434 | is | |
9dfe12ae | 435 | Internal_Flag_Node : constant Node_Id := Flag_Node; |
436 | Internal_Static_Sloc : constant Source_Ptr := Static_Sloc; | |
437 | ||
ee6ba406 | 438 | Checks_On : constant Boolean := |
b6341c67 | 439 | (not Index_Checks_Suppressed (Suppress_Typ)) |
440 | or else (not Range_Checks_Suppressed (Suppress_Typ)); | |
ee6ba406 | 441 | |
442 | begin | |
443 | -- For now we just return if Checks_On is false, however this should | |
444 | -- be enhanced to check for an always True value in the condition | |
445 | -- and to generate a compilation warning??? | |
446 | ||
447 | if not Checks_On then | |
448 | return; | |
449 | end if; | |
450 | ||
451 | for J in 1 .. 2 loop | |
452 | exit when No (Checks (J)); | |
453 | ||
454 | if Nkind (Checks (J)) = N_Raise_Constraint_Error | |
455 | and then Present (Condition (Checks (J))) | |
456 | then | |
457 | if not Has_Dynamic_Range_Check (Internal_Flag_Node) then | |
458 | Append_To (Stmts, Checks (J)); | |
459 | Set_Has_Dynamic_Range_Check (Internal_Flag_Node); | |
460 | end if; | |
461 | ||
462 | else | |
463 | Append_To | |
f15731c4 | 464 | (Stmts, |
465 | Make_Raise_Constraint_Error (Internal_Static_Sloc, | |
466 | Reason => CE_Range_Check_Failed)); | |
ee6ba406 | 467 | end if; |
468 | end loop; | |
469 | end Append_Range_Checks; | |
470 | ||
471 | ------------------------ | |
472 | -- Apply_Access_Check -- | |
473 | ------------------------ | |
474 | ||
475 | procedure Apply_Access_Check (N : Node_Id) is | |
476 | P : constant Node_Id := Prefix (N); | |
477 | ||
478 | begin | |
13dbf220 | 479 | -- We do not need checks if we are not generating code (i.e. the |
480 | -- expander is not active). This is not just an optimization, there | |
481 | -- are cases (e.g. with pragma Debug) where generating the checks | |
482 | -- can cause real trouble). | |
284faf8b | 483 | |
a33565dd | 484 | if not Expander_Active then |
13dbf220 | 485 | return; |
9dfe12ae | 486 | end if; |
ee6ba406 | 487 | |
84d0d4a5 | 488 | -- No check if short circuiting makes check unnecessary |
9dfe12ae | 489 | |
84d0d4a5 | 490 | if not Check_Needed (P, Access_Check) then |
491 | return; | |
ee6ba406 | 492 | end if; |
9dfe12ae | 493 | |
cc60bd16 | 494 | -- No check if accessing the Offset_To_Top component of a dispatch |
495 | -- table. They are safe by construction. | |
496 | ||
040277b1 | 497 | if Tagged_Type_Expansion |
498 | and then Present (Etype (P)) | |
cc60bd16 | 499 | and then RTU_Loaded (Ada_Tags) |
500 | and then RTE_Available (RE_Offset_To_Top_Ptr) | |
501 | and then Etype (P) = RTE (RE_Offset_To_Top_Ptr) | |
502 | then | |
503 | return; | |
504 | end if; | |
505 | ||
84d0d4a5 | 506 | -- Otherwise go ahead and install the check |
9dfe12ae | 507 | |
fa7497e8 | 508 | Install_Null_Excluding_Check (P); |
ee6ba406 | 509 | end Apply_Access_Check; |
510 | ||
511 | ------------------------------- | |
512 | -- Apply_Accessibility_Check -- | |
513 | ------------------------------- | |
514 | ||
55dc6dc2 | 515 | procedure Apply_Accessibility_Check |
516 | (N : Node_Id; | |
517 | Typ : Entity_Id; | |
518 | Insert_Node : Node_Id) | |
519 | is | |
ee6ba406 | 520 | Loc : constant Source_Ptr := Sloc (N); |
1a9cc6cd | 521 | Param_Ent : Entity_Id := Param_Entity (N); |
ee6ba406 | 522 | Param_Level : Node_Id; |
523 | Type_Level : Node_Id; | |
524 | ||
525 | begin | |
47d210a3 | 526 | if Ada_Version >= Ada_2012 |
527 | and then not Present (Param_Ent) | |
528 | and then Is_Entity_Name (N) | |
529 | and then Ekind_In (Entity (N), E_Constant, E_Variable) | |
530 | and then Present (Effective_Extra_Accessibility (Entity (N))) | |
531 | then | |
532 | Param_Ent := Entity (N); | |
533 | while Present (Renamed_Object (Param_Ent)) loop | |
1a9cc6cd | 534 | |
47d210a3 | 535 | -- Renamed_Object must return an Entity_Name here |
536 | -- because of preceding "Present (E_E_A (...))" test. | |
537 | ||
538 | Param_Ent := Entity (Renamed_Object (Param_Ent)); | |
539 | end loop; | |
540 | end if; | |
541 | ||
ee6ba406 | 542 | if Inside_A_Generic then |
543 | return; | |
544 | ||
6ffc64fc | 545 | -- Only apply the run-time check if the access parameter has an |
546 | -- associated extra access level parameter and when the level of the | |
547 | -- type is less deep than the level of the access parameter, and | |
548 | -- accessibility checks are not suppressed. | |
ee6ba406 | 549 | |
550 | elsif Present (Param_Ent) | |
551 | and then Present (Extra_Accessibility (Param_Ent)) | |
47d210a3 | 552 | and then UI_Gt (Object_Access_Level (N), |
1a9cc6cd | 553 | Deepest_Type_Access_Level (Typ)) |
ee6ba406 | 554 | and then not Accessibility_Checks_Suppressed (Param_Ent) |
555 | and then not Accessibility_Checks_Suppressed (Typ) | |
556 | then | |
557 | Param_Level := | |
558 | New_Occurrence_Of (Extra_Accessibility (Param_Ent), Loc); | |
559 | ||
1a9cc6cd | 560 | Type_Level := |
561 | Make_Integer_Literal (Loc, Deepest_Type_Access_Level (Typ)); | |
ee6ba406 | 562 | |
bf3e1520 | 563 | -- Raise Program_Error if the accessibility level of the access |
84d0d4a5 | 564 | -- parameter is deeper than the level of the target access type. |
ee6ba406 | 565 | |
55dc6dc2 | 566 | Insert_Action (Insert_Node, |
ee6ba406 | 567 | Make_Raise_Program_Error (Loc, |
568 | Condition => | |
569 | Make_Op_Gt (Loc, | |
570 | Left_Opnd => Param_Level, | |
f15731c4 | 571 | Right_Opnd => Type_Level), |
572 | Reason => PE_Accessibility_Check_Failed)); | |
ee6ba406 | 573 | |
574 | Analyze_And_Resolve (N); | |
575 | end if; | |
576 | end Apply_Accessibility_Check; | |
577 | ||
0577b0b1 | 578 | -------------------------------- |
579 | -- Apply_Address_Clause_Check -- | |
580 | -------------------------------- | |
581 | ||
582 | procedure Apply_Address_Clause_Check (E : Entity_Id; N : Node_Id) is | |
d950dc79 | 583 | pragma Assert (Nkind (N) = N_Freeze_Entity); |
584 | ||
0577b0b1 | 585 | AC : constant Node_Id := Address_Clause (E); |
586 | Loc : constant Source_Ptr := Sloc (AC); | |
587 | Typ : constant Entity_Id := Etype (E); | |
588 | Aexp : constant Node_Id := Expression (AC); | |
c2b56224 | 589 | |
c2b56224 | 590 | Expr : Node_Id; |
0577b0b1 | 591 | -- Address expression (not necessarily the same as Aexp, for example |
592 | -- when Aexp is a reference to a constant, in which case Expr gets | |
593 | -- reset to reference the value expression of the constant. | |
594 | ||
0577b0b1 | 595 | procedure Compile_Time_Bad_Alignment; |
596 | -- Post error warnings when alignment is known to be incompatible. Note | |
597 | -- that we do not go as far as inserting a raise of Program_Error since | |
598 | -- this is an erroneous case, and it may happen that we are lucky and an | |
d6da7448 | 599 | -- underaligned address turns out to be OK after all. |
0577b0b1 | 600 | |
601 | -------------------------------- | |
602 | -- Compile_Time_Bad_Alignment -- | |
603 | -------------------------------- | |
604 | ||
605 | procedure Compile_Time_Bad_Alignment is | |
606 | begin | |
d6da7448 | 607 | if Address_Clause_Overlay_Warnings then |
0577b0b1 | 608 | Error_Msg_FE |
cb97ae5c | 609 | ("?o?specified address for& may be inconsistent with alignment", |
0577b0b1 | 610 | Aexp, E); |
611 | Error_Msg_FE | |
cb97ae5c | 612 | ("\?o?program execution may be erroneous (RM 13.3(27))", |
0577b0b1 | 613 | Aexp, E); |
83f8f0a6 | 614 | Set_Address_Warning_Posted (AC); |
0577b0b1 | 615 | end if; |
616 | end Compile_Time_Bad_Alignment; | |
c2b56224 | 617 | |
2af58f67 | 618 | -- Start of processing for Apply_Address_Clause_Check |
5c61a0ff | 619 | |
c2b56224 | 620 | begin |
d6da7448 | 621 | -- See if alignment check needed. Note that we never need a check if the |
622 | -- maximum alignment is one, since the check will always succeed. | |
623 | ||
624 | -- Note: we do not check for checks suppressed here, since that check | |
625 | -- was done in Sem_Ch13 when the address clause was processed. We are | |
626 | -- only called if checks were not suppressed. The reason for this is | |
627 | -- that we have to delay the call to Apply_Alignment_Check till freeze | |
628 | -- time (so that all types etc are elaborated), but we have to check | |
629 | -- the status of check suppressing at the point of the address clause. | |
630 | ||
631 | if No (AC) | |
632 | or else not Check_Address_Alignment (AC) | |
633 | or else Maximum_Alignment = 1 | |
634 | then | |
635 | return; | |
636 | end if; | |
637 | ||
638 | -- Obtain expression from address clause | |
9dfe12ae | 639 | |
0577b0b1 | 640 | Expr := Expression (AC); |
641 | ||
642 | -- The following loop digs for the real expression to use in the check | |
643 | ||
644 | loop | |
645 | -- For constant, get constant expression | |
646 | ||
647 | if Is_Entity_Name (Expr) | |
648 | and then Ekind (Entity (Expr)) = E_Constant | |
649 | then | |
650 | Expr := Constant_Value (Entity (Expr)); | |
651 | ||
652 | -- For unchecked conversion, get result to convert | |
653 | ||
654 | elsif Nkind (Expr) = N_Unchecked_Type_Conversion then | |
655 | Expr := Expression (Expr); | |
656 | ||
657 | -- For (common case) of To_Address call, get argument | |
658 | ||
659 | elsif Nkind (Expr) = N_Function_Call | |
660 | and then Is_Entity_Name (Name (Expr)) | |
661 | and then Is_RTE (Entity (Name (Expr)), RE_To_Address) | |
662 | then | |
663 | Expr := First (Parameter_Associations (Expr)); | |
664 | ||
665 | if Nkind (Expr) = N_Parameter_Association then | |
666 | Expr := Explicit_Actual_Parameter (Expr); | |
667 | end if; | |
668 | ||
669 | -- We finally have the real expression | |
670 | ||
671 | else | |
672 | exit; | |
673 | end if; | |
674 | end loop; | |
675 | ||
d6da7448 | 676 | -- See if we know that Expr has a bad alignment at compile time |
c2b56224 | 677 | |
678 | if Compile_Time_Known_Value (Expr) | |
f2a06be9 | 679 | and then (Known_Alignment (E) or else Known_Alignment (Typ)) |
c2b56224 | 680 | then |
f2a06be9 | 681 | declare |
682 | AL : Uint := Alignment (Typ); | |
683 | ||
684 | begin | |
685 | -- The object alignment might be more restrictive than the | |
686 | -- type alignment. | |
687 | ||
688 | if Known_Alignment (E) then | |
689 | AL := Alignment (E); | |
690 | end if; | |
691 | ||
692 | if Expr_Value (Expr) mod AL /= 0 then | |
0577b0b1 | 693 | Compile_Time_Bad_Alignment; |
694 | else | |
695 | return; | |
f2a06be9 | 696 | end if; |
697 | end; | |
c2b56224 | 698 | |
0577b0b1 | 699 | -- If the expression has the form X'Address, then we can find out if |
700 | -- the object X has an alignment that is compatible with the object E. | |
d6da7448 | 701 | -- If it hasn't or we don't know, we defer issuing the warning until |
702 | -- the end of the compilation to take into account back end annotations. | |
c2b56224 | 703 | |
0577b0b1 | 704 | elsif Nkind (Expr) = N_Attribute_Reference |
705 | and then Attribute_Name (Expr) = Name_Address | |
d6da7448 | 706 | and then Has_Compatible_Alignment (E, Prefix (Expr)) = Known_Compatible |
0577b0b1 | 707 | then |
d6da7448 | 708 | return; |
0577b0b1 | 709 | end if; |
c2b56224 | 710 | |
6fb3c314 | 711 | -- Here we do not know if the value is acceptable. Strictly we don't |
712 | -- have to do anything, since if the alignment is bad, we have an | |
713 | -- erroneous program. However we are allowed to check for erroneous | |
714 | -- conditions and we decide to do this by default if the check is not | |
715 | -- suppressed. | |
0577b0b1 | 716 | |
717 | -- However, don't do the check if elaboration code is unwanted | |
718 | ||
719 | if Restriction_Active (No_Elaboration_Code) then | |
720 | return; | |
721 | ||
722 | -- Generate a check to raise PE if alignment may be inappropriate | |
723 | ||
724 | else | |
725 | -- If the original expression is a non-static constant, use the | |
726 | -- name of the constant itself rather than duplicating its | |
00c403ee | 727 | -- defining expression, which was extracted above. |
0577b0b1 | 728 | |
00c403ee | 729 | -- Note: Expr is empty if the address-clause is applied to in-mode |
730 | -- actuals (allowed by 13.1(22)). | |
731 | ||
732 | if not Present (Expr) | |
733 | or else | |
734 | (Is_Entity_Name (Expression (AC)) | |
735 | and then Ekind (Entity (Expression (AC))) = E_Constant | |
736 | and then Nkind (Parent (Entity (Expression (AC)))) | |
737 | = N_Object_Declaration) | |
0577b0b1 | 738 | then |
739 | Expr := New_Copy_Tree (Expression (AC)); | |
740 | else | |
741 | Remove_Side_Effects (Expr); | |
c2b56224 | 742 | end if; |
c2b56224 | 743 | |
d950dc79 | 744 | if No (Actions (N)) then |
745 | Set_Actions (N, New_List); | |
746 | end if; | |
747 | ||
748 | Prepend_To (Actions (N), | |
0577b0b1 | 749 | Make_Raise_Program_Error (Loc, |
750 | Condition => | |
751 | Make_Op_Ne (Loc, | |
752 | Left_Opnd => | |
753 | Make_Op_Mod (Loc, | |
754 | Left_Opnd => | |
755 | Unchecked_Convert_To | |
756 | (RTE (RE_Integer_Address), Expr), | |
757 | Right_Opnd => | |
758 | Make_Attribute_Reference (Loc, | |
d950dc79 | 759 | Prefix => New_Occurrence_Of (E, Loc), |
0577b0b1 | 760 | Attribute_Name => Name_Alignment)), |
761 | Right_Opnd => Make_Integer_Literal (Loc, Uint_0)), | |
d950dc79 | 762 | Reason => PE_Misaligned_Address_Value)); |
763 | Analyze (First (Actions (N)), Suppress => All_Checks); | |
cd309f05 | 764 | |
765 | -- If the address clause generates an alignment check and we are | |
766 | -- in ZPF or some restricted run-time, add a warning to explain | |
767 | -- the propagation warning that is generated by the check. | |
768 | ||
769 | if Nkind (First (Actions (N))) = N_Raise_Program_Error | |
770 | and then not Warnings_Off (E) | |
771 | and then Restriction_Active (No_Exception_Propagation) | |
772 | then | |
78be29d1 | 773 | Error_Msg_N |
774 | ("address value may be incompatible with alignment of object?", | |
775 | N); | |
cd309f05 | 776 | end if; |
78be29d1 | 777 | |
0577b0b1 | 778 | return; |
779 | end if; | |
9dfe12ae | 780 | |
781 | exception | |
0577b0b1 | 782 | -- If we have some missing run time component in configurable run time |
783 | -- mode then just skip the check (it is not required in any case). | |
784 | ||
9dfe12ae | 785 | when RE_Not_Available => |
786 | return; | |
0577b0b1 | 787 | end Apply_Address_Clause_Check; |
c2b56224 | 788 | |
ee6ba406 | 789 | ------------------------------------- |
790 | -- Apply_Arithmetic_Overflow_Check -- | |
791 | ------------------------------------- | |
792 | ||
3cce7f32 | 793 | procedure Apply_Arithmetic_Overflow_Check (N : Node_Id) is |
794 | begin | |
795 | -- Use old routine in almost all cases (the only case we are treating | |
21a55437 | 796 | -- specially is the case of a signed integer arithmetic op with the |
0df9d43f | 797 | -- overflow checking mode set to MINIMIZED or ELIMINATED). |
3cce7f32 | 798 | |
0df9d43f | 799 | if Overflow_Check_Mode = Strict |
3cce7f32 | 800 | or else not Is_Signed_Integer_Arithmetic_Op (N) |
801 | then | |
0df9d43f | 802 | Apply_Arithmetic_Overflow_Strict (N); |
3cce7f32 | 803 | |
21a55437 | 804 | -- Otherwise use the new routine for the case of a signed integer |
805 | -- arithmetic op, with Do_Overflow_Check set to True, and the checking | |
806 | -- mode is MINIMIZED or ELIMINATED. | |
3cce7f32 | 807 | |
808 | else | |
809 | Apply_Arithmetic_Overflow_Minimized_Eliminated (N); | |
810 | end if; | |
811 | end Apply_Arithmetic_Overflow_Check; | |
812 | ||
0df9d43f | 813 | -------------------------------------- |
814 | -- Apply_Arithmetic_Overflow_Strict -- | |
815 | -------------------------------------- | |
3cce7f32 | 816 | |
f40f9731 | 817 | -- This routine is called only if the type is an integer type, and a |
818 | -- software arithmetic overflow check may be needed for op (add, subtract, | |
819 | -- or multiply). This check is performed only if Software_Overflow_Checking | |
820 | -- is enabled and Do_Overflow_Check is set. In this case we expand the | |
821 | -- operation into a more complex sequence of tests that ensures that | |
822 | -- overflow is properly caught. | |
ee6ba406 | 823 | |
0df9d43f | 824 | -- This is used in CHECKED modes. It is identical to the code for this |
825 | -- cases before the big overflow earthquake, thus ensuring that in this | |
826 | -- modes we have compatible behavior (and reliability) to what was there | |
827 | -- before. It is also called for types other than signed integers, and if | |
828 | -- the Do_Overflow_Check flag is off. | |
3cce7f32 | 829 | |
830 | -- Note: we also call this routine if we decide in the MINIMIZED case | |
831 | -- to give up and just generate an overflow check without any fuss. | |
832 | ||
0df9d43f | 833 | procedure Apply_Arithmetic_Overflow_Strict (N : Node_Id) is |
21a55437 | 834 | Loc : constant Source_Ptr := Sloc (N); |
835 | Typ : constant Entity_Id := Etype (N); | |
836 | Rtyp : constant Entity_Id := Root_Type (Typ); | |
ee6ba406 | 837 | |
838 | begin | |
0df9d43f | 839 | -- Nothing to do if Do_Overflow_Check not set or overflow checks |
840 | -- suppressed. | |
841 | ||
842 | if not Do_Overflow_Check (N) then | |
843 | return; | |
844 | end if; | |
845 | ||
f40f9731 | 846 | -- An interesting special case. If the arithmetic operation appears as |
847 | -- the operand of a type conversion: | |
848 | ||
849 | -- type1 (x op y) | |
850 | ||
851 | -- and all the following conditions apply: | |
852 | ||
853 | -- arithmetic operation is for a signed integer type | |
854 | -- target type type1 is a static integer subtype | |
855 | -- range of x and y are both included in the range of type1 | |
856 | -- range of x op y is included in the range of type1 | |
857 | -- size of type1 is at least twice the result size of op | |
858 | ||
859 | -- then we don't do an overflow check in any case, instead we transform | |
860 | -- the operation so that we end up with: | |
861 | ||
862 | -- type1 (type1 (x) op type1 (y)) | |
863 | ||
864 | -- This avoids intermediate overflow before the conversion. It is | |
865 | -- explicitly permitted by RM 3.5.4(24): | |
866 | ||
867 | -- For the execution of a predefined operation of a signed integer | |
868 | -- type, the implementation need not raise Constraint_Error if the | |
869 | -- result is outside the base range of the type, so long as the | |
870 | -- correct result is produced. | |
871 | ||
872 | -- It's hard to imagine that any programmer counts on the exception | |
873 | -- being raised in this case, and in any case it's wrong coding to | |
874 | -- have this expectation, given the RM permission. Furthermore, other | |
875 | -- Ada compilers do allow such out of range results. | |
876 | ||
877 | -- Note that we do this transformation even if overflow checking is | |
878 | -- off, since this is precisely about giving the "right" result and | |
879 | -- avoiding the need for an overflow check. | |
880 | ||
8eb4a5eb | 881 | -- Note: this circuit is partially redundant with respect to the similar |
882 | -- processing in Exp_Ch4.Expand_N_Type_Conversion, but the latter deals | |
883 | -- with cases that do not come through here. We still need the following | |
884 | -- processing even with the Exp_Ch4 code in place, since we want to be | |
885 | -- sure not to generate the arithmetic overflow check in these cases | |
886 | -- (Exp_Ch4 would have a hard time removing them once generated). | |
887 | ||
f40f9731 | 888 | if Is_Signed_Integer_Type (Typ) |
889 | and then Nkind (Parent (N)) = N_Type_Conversion | |
ee6ba406 | 890 | then |
f32c377d | 891 | Conversion_Optimization : declare |
f40f9731 | 892 | Target_Type : constant Entity_Id := |
b6341c67 | 893 | Base_Type (Entity (Subtype_Mark (Parent (N)))); |
f40f9731 | 894 | |
895 | Llo, Lhi : Uint; | |
896 | Rlo, Rhi : Uint; | |
897 | LOK, ROK : Boolean; | |
898 | ||
899 | Vlo : Uint; | |
900 | Vhi : Uint; | |
901 | VOK : Boolean; | |
902 | ||
903 | Tlo : Uint; | |
904 | Thi : Uint; | |
905 | ||
906 | begin | |
907 | if Is_Integer_Type (Target_Type) | |
908 | and then RM_Size (Root_Type (Target_Type)) >= 2 * RM_Size (Rtyp) | |
909 | then | |
910 | Tlo := Expr_Value (Type_Low_Bound (Target_Type)); | |
911 | Thi := Expr_Value (Type_High_Bound (Target_Type)); | |
912 | ||
9c486805 | 913 | Determine_Range |
914 | (Left_Opnd (N), LOK, Llo, Lhi, Assume_Valid => True); | |
915 | Determine_Range | |
916 | (Right_Opnd (N), ROK, Rlo, Rhi, Assume_Valid => True); | |
f40f9731 | 917 | |
918 | if (LOK and ROK) | |
919 | and then Tlo <= Llo and then Lhi <= Thi | |
920 | and then Tlo <= Rlo and then Rhi <= Thi | |
921 | then | |
9c486805 | 922 | Determine_Range (N, VOK, Vlo, Vhi, Assume_Valid => True); |
f40f9731 | 923 | |
924 | if VOK and then Tlo <= Vlo and then Vhi <= Thi then | |
925 | Rewrite (Left_Opnd (N), | |
926 | Make_Type_Conversion (Loc, | |
927 | Subtype_Mark => New_Occurrence_Of (Target_Type, Loc), | |
928 | Expression => Relocate_Node (Left_Opnd (N)))); | |
929 | ||
930 | Rewrite (Right_Opnd (N), | |
931 | Make_Type_Conversion (Loc, | |
932 | Subtype_Mark => New_Occurrence_Of (Target_Type, Loc), | |
933 | Expression => Relocate_Node (Right_Opnd (N)))); | |
934 | ||
780bfb21 | 935 | -- Rewrite the conversion operand so that the original |
936 | -- node is retained, in order to avoid the warning for | |
937 | -- redundant conversions in Resolve_Type_Conversion. | |
938 | ||
939 | Rewrite (N, Relocate_Node (N)); | |
940 | ||
f40f9731 | 941 | Set_Etype (N, Target_Type); |
780bfb21 | 942 | |
f40f9731 | 943 | Analyze_And_Resolve (Left_Opnd (N), Target_Type); |
944 | Analyze_And_Resolve (Right_Opnd (N), Target_Type); | |
945 | ||
946 | -- Given that the target type is twice the size of the | |
947 | -- source type, overflow is now impossible, so we can | |
948 | -- safely kill the overflow check and return. | |
949 | ||
950 | Set_Do_Overflow_Check (N, False); | |
951 | return; | |
952 | end if; | |
953 | end if; | |
954 | end if; | |
f32c377d | 955 | end Conversion_Optimization; |
ee6ba406 | 956 | end if; |
957 | ||
f40f9731 | 958 | -- Now see if an overflow check is required |
959 | ||
960 | declare | |
961 | Siz : constant Int := UI_To_Int (Esize (Rtyp)); | |
962 | Dsiz : constant Int := Siz * 2; | |
963 | Opnod : Node_Id; | |
964 | Ctyp : Entity_Id; | |
965 | Opnd : Node_Id; | |
966 | Cent : RE_Id; | |
ee6ba406 | 967 | |
f40f9731 | 968 | begin |
969 | -- Skip check if back end does overflow checks, or the overflow flag | |
df40eeb0 | 970 | -- is not set anyway, or we are not doing code expansion, or the |
971 | -- parent node is a type conversion whose operand is an arithmetic | |
972 | -- operation on signed integers on which the expander can promote | |
bbbed24b | 973 | -- later the operands to type Integer (see Expand_N_Type_Conversion). |
ee6ba406 | 974 | |
f40f9731 | 975 | -- Special case CLI target, where arithmetic overflow checks can be |
976 | -- performed for integer and long_integer | |
ee6ba406 | 977 | |
f40f9731 | 978 | if Backend_Overflow_Checks_On_Target |
979 | or else not Do_Overflow_Check (N) | |
a33565dd | 980 | or else not Expander_Active |
df40eeb0 | 981 | or else (Present (Parent (N)) |
982 | and then Nkind (Parent (N)) = N_Type_Conversion | |
983 | and then Integer_Promotion_Possible (Parent (N))) | |
f40f9731 | 984 | or else |
985 | (VM_Target = CLI_Target and then Siz >= Standard_Integer_Size) | |
986 | then | |
987 | return; | |
988 | end if; | |
ee6ba406 | 989 | |
f40f9731 | 990 | -- Otherwise, generate the full general code for front end overflow |
991 | -- detection, which works by doing arithmetic in a larger type: | |
ee6ba406 | 992 | |
f40f9731 | 993 | -- x op y |
ee6ba406 | 994 | |
f40f9731 | 995 | -- is expanded into |
ee6ba406 | 996 | |
f40f9731 | 997 | -- Typ (Checktyp (x) op Checktyp (y)); |
ee6ba406 | 998 | |
f40f9731 | 999 | -- where Typ is the type of the original expression, and Checktyp is |
1000 | -- an integer type of sufficient length to hold the largest possible | |
1001 | -- result. | |
ee6ba406 | 1002 | |
f40f9731 | 1003 | -- If the size of check type exceeds the size of Long_Long_Integer, |
1004 | -- we use a different approach, expanding to: | |
ee6ba406 | 1005 | |
f40f9731 | 1006 | -- typ (xxx_With_Ovflo_Check (Integer_64 (x), Integer (y))) |
ee6ba406 | 1007 | |
f40f9731 | 1008 | -- where xxx is Add, Multiply or Subtract as appropriate |
ee6ba406 | 1009 | |
f40f9731 | 1010 | -- Find check type if one exists |
1011 | ||
1012 | if Dsiz <= Standard_Integer_Size then | |
1013 | Ctyp := Standard_Integer; | |
ee6ba406 | 1014 | |
f40f9731 | 1015 | elsif Dsiz <= Standard_Long_Long_Integer_Size then |
1016 | Ctyp := Standard_Long_Long_Integer; | |
1017 | ||
c9f84db7 | 1018 | -- No check type exists, use runtime call |
ee6ba406 | 1019 | |
1020 | else | |
f40f9731 | 1021 | if Nkind (N) = N_Op_Add then |
1022 | Cent := RE_Add_With_Ovflo_Check; | |
ee6ba406 | 1023 | |
f40f9731 | 1024 | elsif Nkind (N) = N_Op_Multiply then |
1025 | Cent := RE_Multiply_With_Ovflo_Check; | |
ee6ba406 | 1026 | |
f40f9731 | 1027 | else |
1028 | pragma Assert (Nkind (N) = N_Op_Subtract); | |
1029 | Cent := RE_Subtract_With_Ovflo_Check; | |
1030 | end if; | |
1031 | ||
1032 | Rewrite (N, | |
1033 | OK_Convert_To (Typ, | |
1034 | Make_Function_Call (Loc, | |
1035 | Name => New_Reference_To (RTE (Cent), Loc), | |
1036 | Parameter_Associations => New_List ( | |
1037 | OK_Convert_To (RTE (RE_Integer_64), Left_Opnd (N)), | |
1038 | OK_Convert_To (RTE (RE_Integer_64), Right_Opnd (N)))))); | |
ee6ba406 | 1039 | |
f40f9731 | 1040 | Analyze_And_Resolve (N, Typ); |
1041 | return; | |
1042 | end if; | |
ee6ba406 | 1043 | |
f40f9731 | 1044 | -- If we fall through, we have the case where we do the arithmetic |
1045 | -- in the next higher type and get the check by conversion. In these | |
1046 | -- cases Ctyp is set to the type to be used as the check type. | |
ee6ba406 | 1047 | |
f40f9731 | 1048 | Opnod := Relocate_Node (N); |
ee6ba406 | 1049 | |
f40f9731 | 1050 | Opnd := OK_Convert_To (Ctyp, Left_Opnd (Opnod)); |
ee6ba406 | 1051 | |
f40f9731 | 1052 | Analyze (Opnd); |
1053 | Set_Etype (Opnd, Ctyp); | |
1054 | Set_Analyzed (Opnd, True); | |
1055 | Set_Left_Opnd (Opnod, Opnd); | |
ee6ba406 | 1056 | |
f40f9731 | 1057 | Opnd := OK_Convert_To (Ctyp, Right_Opnd (Opnod)); |
ee6ba406 | 1058 | |
f40f9731 | 1059 | Analyze (Opnd); |
1060 | Set_Etype (Opnd, Ctyp); | |
1061 | Set_Analyzed (Opnd, True); | |
1062 | Set_Right_Opnd (Opnod, Opnd); | |
ee6ba406 | 1063 | |
f40f9731 | 1064 | -- The type of the operation changes to the base type of the check |
1065 | -- type, and we reset the overflow check indication, since clearly no | |
1066 | -- overflow is possible now that we are using a double length type. | |
1067 | -- We also set the Analyzed flag to avoid a recursive attempt to | |
1068 | -- expand the node. | |
ee6ba406 | 1069 | |
f40f9731 | 1070 | Set_Etype (Opnod, Base_Type (Ctyp)); |
1071 | Set_Do_Overflow_Check (Opnod, False); | |
1072 | Set_Analyzed (Opnod, True); | |
ee6ba406 | 1073 | |
f40f9731 | 1074 | -- Now build the outer conversion |
ee6ba406 | 1075 | |
f40f9731 | 1076 | Opnd := OK_Convert_To (Typ, Opnod); |
1077 | Analyze (Opnd); | |
1078 | Set_Etype (Opnd, Typ); | |
9dfe12ae | 1079 | |
f40f9731 | 1080 | -- In the discrete type case, we directly generate the range check |
1081 | -- for the outer operand. This range check will implement the | |
1082 | -- required overflow check. | |
9dfe12ae | 1083 | |
f40f9731 | 1084 | if Is_Discrete_Type (Typ) then |
1085 | Rewrite (N, Opnd); | |
1086 | Generate_Range_Check | |
1087 | (Expression (N), Typ, CE_Overflow_Check_Failed); | |
9dfe12ae | 1088 | |
f40f9731 | 1089 | -- For other types, we enable overflow checking on the conversion, |
1090 | -- after setting the node as analyzed to prevent recursive attempts | |
1091 | -- to expand the conversion node. | |
9dfe12ae | 1092 | |
f40f9731 | 1093 | else |
1094 | Set_Analyzed (Opnd, True); | |
1095 | Enable_Overflow_Check (Opnd); | |
1096 | Rewrite (N, Opnd); | |
1097 | end if; | |
1098 | ||
1099 | exception | |
1100 | when RE_Not_Available => | |
1101 | return; | |
1102 | end; | |
0df9d43f | 1103 | end Apply_Arithmetic_Overflow_Strict; |
3cce7f32 | 1104 | |
1105 | ---------------------------------------------------- | |
1106 | -- Apply_Arithmetic_Overflow_Minimized_Eliminated -- | |
1107 | ---------------------------------------------------- | |
1108 | ||
1109 | procedure Apply_Arithmetic_Overflow_Minimized_Eliminated (Op : Node_Id) is | |
1110 | pragma Assert (Is_Signed_Integer_Arithmetic_Op (Op)); | |
3cce7f32 | 1111 | |
1112 | Loc : constant Source_Ptr := Sloc (Op); | |
1113 | P : constant Node_Id := Parent (Op); | |
1114 | ||
49b3a812 | 1115 | LLIB : constant Entity_Id := Base_Type (Standard_Long_Long_Integer); |
1116 | -- Operands and results are of this type when we convert | |
1117 | ||
3cce7f32 | 1118 | Result_Type : constant Entity_Id := Etype (Op); |
1119 | -- Original result type | |
1120 | ||
db415383 | 1121 | Check_Mode : constant Overflow_Mode_Type := Overflow_Check_Mode; |
3cce7f32 | 1122 | pragma Assert (Check_Mode in Minimized_Or_Eliminated); |
1123 | ||
1124 | Lo, Hi : Uint; | |
1125 | -- Ranges of values for result | |
1126 | ||
1127 | begin | |
1128 | -- Nothing to do if our parent is one of the following: | |
1129 | ||
0326b4d4 | 1130 | -- Another signed integer arithmetic op |
3cce7f32 | 1131 | -- A membership operation |
1132 | -- A comparison operation | |
1133 | ||
1134 | -- In all these cases, we will process at the higher level (and then | |
1135 | -- this node will be processed during the downwards recursion that | |
0df9d43f | 1136 | -- is part of the processing in Minimize_Eliminate_Overflows). |
3cce7f32 | 1137 | |
1138 | if Is_Signed_Integer_Arithmetic_Op (P) | |
b8a17a21 | 1139 | or else Nkind (P) in N_Membership_Test |
1140 | or else Nkind (P) in N_Op_Compare | |
aa4b16cb | 1141 | |
70a2dff4 | 1142 | -- This is also true for an alternative in a case expression |
1143 | ||
1144 | or else Nkind (P) = N_Case_Expression_Alternative | |
1145 | ||
1146 | -- This is also true for a range operand in a membership test | |
aa4b16cb | 1147 | |
b8a17a21 | 1148 | or else (Nkind (P) = N_Range |
1149 | and then Nkind (Parent (P)) in N_Membership_Test) | |
3cce7f32 | 1150 | then |
1151 | return; | |
1152 | end if; | |
1153 | ||
0326b4d4 | 1154 | -- Otherwise, we have a top level arithmetic operation node, and this |
21a55437 | 1155 | -- is where we commence the special processing for MINIMIZED/ELIMINATED |
1156 | -- modes. This is the case where we tell the machinery not to move into | |
1157 | -- Bignum mode at this top level (of course the top level operation | |
1158 | -- will still be in Bignum mode if either of its operands are of type | |
1159 | -- Bignum). | |
3cce7f32 | 1160 | |
0df9d43f | 1161 | Minimize_Eliminate_Overflows (Op, Lo, Hi, Top_Level => True); |
3cce7f32 | 1162 | |
1163 | -- That call may but does not necessarily change the result type of Op. | |
1164 | -- It is the job of this routine to undo such changes, so that at the | |
1165 | -- top level, we have the proper type. This "undoing" is a point at | |
1166 | -- which a final overflow check may be applied. | |
1167 | ||
f32c377d | 1168 | -- If the result type was not fiddled we are all set. We go to base |
1169 | -- types here because things may have been rewritten to generate the | |
1170 | -- base type of the operand types. | |
3cce7f32 | 1171 | |
f32c377d | 1172 | if Base_Type (Etype (Op)) = Base_Type (Result_Type) then |
3cce7f32 | 1173 | return; |
1174 | ||
1175 | -- Bignum case | |
1176 | ||
49b3a812 | 1177 | elsif Is_RTE (Etype (Op), RE_Bignum) then |
3cce7f32 | 1178 | |
d94b5da2 | 1179 | -- We need a sequence that looks like: |
3cce7f32 | 1180 | |
1181 | -- Rnn : Result_Type; | |
1182 | ||
1183 | -- declare | |
d94b5da2 | 1184 | -- M : Mark_Id := SS_Mark; |
3cce7f32 | 1185 | -- begin |
49b3a812 | 1186 | -- Rnn := Long_Long_Integer'Base (From_Bignum (Op)); |
3cce7f32 | 1187 | -- SS_Release (M); |
1188 | -- end; | |
1189 | ||
1190 | -- This block is inserted (using Insert_Actions), and then the node | |
1191 | -- is replaced with a reference to Rnn. | |
1192 | ||
1193 | -- A special case arises if our parent is a conversion node. In this | |
1194 | -- case no point in generating a conversion to Result_Type, we will | |
1195 | -- let the parent handle this. Note that this special case is not | |
1196 | -- just about optimization. Consider | |
1197 | ||
1198 | -- A,B,C : Integer; | |
1199 | -- ... | |
49b3a812 | 1200 | -- X := Long_Long_Integer'Base (A * (B ** C)); |
3cce7f32 | 1201 | |
1202 | -- Now the product may fit in Long_Long_Integer but not in Integer. | |
21a55437 | 1203 | -- In MINIMIZED/ELIMINATED mode, we don't want to introduce an |
1204 | -- overflow exception for this intermediate value. | |
3cce7f32 | 1205 | |
1206 | declare | |
49b3a812 | 1207 | Blk : constant Node_Id := Make_Bignum_Block (Loc); |
3cce7f32 | 1208 | Rnn : constant Entity_Id := Make_Temporary (Loc, 'R', Op); |
1209 | RHS : Node_Id; | |
1210 | ||
1211 | Rtype : Entity_Id; | |
1212 | ||
1213 | begin | |
1214 | RHS := Convert_From_Bignum (Op); | |
1215 | ||
1216 | if Nkind (P) /= N_Type_Conversion then | |
49b3a812 | 1217 | Convert_To_And_Rewrite (Result_Type, RHS); |
3cce7f32 | 1218 | Rtype := Result_Type; |
1219 | ||
1220 | -- Interesting question, do we need a check on that conversion | |
1221 | -- operation. Answer, not if we know the result is in range. | |
1222 | -- At the moment we are not taking advantage of this. To be | |
1223 | -- looked at later ??? | |
1224 | ||
1225 | else | |
49b3a812 | 1226 | Rtype := LLIB; |
3cce7f32 | 1227 | end if; |
1228 | ||
1229 | Insert_Before | |
1230 | (First (Statements (Handled_Statement_Sequence (Blk))), | |
1231 | Make_Assignment_Statement (Loc, | |
1232 | Name => New_Occurrence_Of (Rnn, Loc), | |
1233 | Expression => RHS)); | |
1234 | ||
1235 | Insert_Actions (Op, New_List ( | |
1236 | Make_Object_Declaration (Loc, | |
1237 | Defining_Identifier => Rnn, | |
1238 | Object_Definition => New_Occurrence_Of (Rtype, Loc)), | |
1239 | Blk)); | |
1240 | ||
1241 | Rewrite (Op, New_Occurrence_Of (Rnn, Loc)); | |
1242 | Analyze_And_Resolve (Op); | |
1243 | end; | |
1244 | ||
412f75eb | 1245 | -- Here we know the result is Long_Long_Integer'Base, of that it has |
1246 | -- been rewritten because the parent operation is a conversion. See | |
0df9d43f | 1247 | -- Apply_Arithmetic_Overflow_Strict.Conversion_Optimization. |
3cce7f32 | 1248 | |
1249 | else | |
f32c377d | 1250 | pragma Assert |
1251 | (Etype (Op) = LLIB or else Nkind (Parent (Op)) = N_Type_Conversion); | |
3cce7f32 | 1252 | |
1253 | -- All we need to do here is to convert the result to the proper | |
1254 | -- result type. As explained above for the Bignum case, we can | |
1255 | -- omit this if our parent is a type conversion. | |
1256 | ||
1257 | if Nkind (P) /= N_Type_Conversion then | |
1258 | Convert_To_And_Rewrite (Result_Type, Op); | |
1259 | end if; | |
1260 | ||
1261 | Analyze_And_Resolve (Op); | |
1262 | end if; | |
1263 | end Apply_Arithmetic_Overflow_Minimized_Eliminated; | |
ee6ba406 | 1264 | |
ee6ba406 | 1265 | ---------------------------- |
1266 | -- Apply_Constraint_Check -- | |
1267 | ---------------------------- | |
1268 | ||
1269 | procedure Apply_Constraint_Check | |
1270 | (N : Node_Id; | |
1271 | Typ : Entity_Id; | |
1272 | No_Sliding : Boolean := False) | |
1273 | is | |
1274 | Desig_Typ : Entity_Id; | |
1275 | ||
1276 | begin | |
7aafae1c | 1277 | -- No checks inside a generic (check the instantiations) |
1278 | ||
ee6ba406 | 1279 | if Inside_A_Generic then |
1280 | return; | |
7aafae1c | 1281 | end if; |
ee6ba406 | 1282 | |
6fb3c314 | 1283 | -- Apply required constraint checks |
7aafae1c | 1284 | |
1285 | if Is_Scalar_Type (Typ) then | |
ee6ba406 | 1286 | Apply_Scalar_Range_Check (N, Typ); |
1287 | ||
1288 | elsif Is_Array_Type (Typ) then | |
1289 | ||
05fcfafb | 1290 | -- A useful optimization: an aggregate with only an others clause |
5f260d20 | 1291 | -- always has the right bounds. |
1292 | ||
1293 | if Nkind (N) = N_Aggregate | |
1294 | and then No (Expressions (N)) | |
1295 | and then Nkind | |
1296 | (First (Choices (First (Component_Associations (N))))) | |
1297 | = N_Others_Choice | |
1298 | then | |
1299 | return; | |
1300 | end if; | |
1301 | ||
ee6ba406 | 1302 | if Is_Constrained (Typ) then |
1303 | Apply_Length_Check (N, Typ); | |
1304 | ||
1305 | if No_Sliding then | |
1306 | Apply_Range_Check (N, Typ); | |
1307 | end if; | |
1308 | else | |
1309 | Apply_Range_Check (N, Typ); | |
1310 | end if; | |
1311 | ||
4fb5f0a0 | 1312 | elsif (Is_Record_Type (Typ) or else Is_Private_Type (Typ)) |
ee6ba406 | 1313 | and then Has_Discriminants (Base_Type (Typ)) |
1314 | and then Is_Constrained (Typ) | |
1315 | then | |
1316 | Apply_Discriminant_Check (N, Typ); | |
1317 | ||
1318 | elsif Is_Access_Type (Typ) then | |
1319 | ||
1320 | Desig_Typ := Designated_Type (Typ); | |
1321 | ||
1322 | -- No checks necessary if expression statically null | |
1323 | ||
2af58f67 | 1324 | if Known_Null (N) then |
00c403ee | 1325 | if Can_Never_Be_Null (Typ) then |
1326 | Install_Null_Excluding_Check (N); | |
1327 | end if; | |
ee6ba406 | 1328 | |
1329 | -- No sliding possible on access to arrays | |
1330 | ||
1331 | elsif Is_Array_Type (Desig_Typ) then | |
1332 | if Is_Constrained (Desig_Typ) then | |
1333 | Apply_Length_Check (N, Typ); | |
1334 | end if; | |
1335 | ||
1336 | Apply_Range_Check (N, Typ); | |
1337 | ||
1338 | elsif Has_Discriminants (Base_Type (Desig_Typ)) | |
1339 | and then Is_Constrained (Desig_Typ) | |
1340 | then | |
1341 | Apply_Discriminant_Check (N, Typ); | |
1342 | end if; | |
fa7497e8 | 1343 | |
bf3e1520 | 1344 | -- Apply the 2005 Null_Excluding check. Note that we do not apply |
00c403ee | 1345 | -- this check if the constraint node is illegal, as shown by having |
1346 | -- an error posted. This additional guard prevents cascaded errors | |
1347 | -- and compiler aborts on illegal programs involving Ada 2005 checks. | |
1348 | ||
fa7497e8 | 1349 | if Can_Never_Be_Null (Typ) |
1350 | and then not Can_Never_Be_Null (Etype (N)) | |
00c403ee | 1351 | and then not Error_Posted (N) |
fa7497e8 | 1352 | then |
1353 | Install_Null_Excluding_Check (N); | |
1354 | end if; | |
ee6ba406 | 1355 | end if; |
1356 | end Apply_Constraint_Check; | |
1357 | ||
1358 | ------------------------------ | |
1359 | -- Apply_Discriminant_Check -- | |
1360 | ------------------------------ | |
1361 | ||
1362 | procedure Apply_Discriminant_Check | |
1363 | (N : Node_Id; | |
1364 | Typ : Entity_Id; | |
1365 | Lhs : Node_Id := Empty) | |
1366 | is | |
1367 | Loc : constant Source_Ptr := Sloc (N); | |
1368 | Do_Access : constant Boolean := Is_Access_Type (Typ); | |
1369 | S_Typ : Entity_Id := Etype (N); | |
1370 | Cond : Node_Id; | |
1371 | T_Typ : Entity_Id; | |
1372 | ||
7be5088a | 1373 | function Denotes_Explicit_Dereference (Obj : Node_Id) return Boolean; |
1374 | -- A heap object with an indefinite subtype is constrained by its | |
1375 | -- initial value, and assigning to it requires a constraint_check. | |
1376 | -- The target may be an explicit dereference, or a renaming of one. | |
1377 | ||
ee6ba406 | 1378 | function Is_Aliased_Unconstrained_Component return Boolean; |
1379 | -- It is possible for an aliased component to have a nominal | |
1380 | -- unconstrained subtype (through instantiation). If this is a | |
1381 | -- discriminated component assigned in the expansion of an aggregate | |
1382 | -- in an initialization, the check must be suppressed. This unusual | |
2af58f67 | 1383 | -- situation requires a predicate of its own. |
ee6ba406 | 1384 | |
7be5088a | 1385 | ---------------------------------- |
1386 | -- Denotes_Explicit_Dereference -- | |
1387 | ---------------------------------- | |
1388 | ||
1389 | function Denotes_Explicit_Dereference (Obj : Node_Id) return Boolean is | |
1390 | begin | |
1391 | return | |
1392 | Nkind (Obj) = N_Explicit_Dereference | |
1393 | or else | |
1394 | (Is_Entity_Name (Obj) | |
1395 | and then Present (Renamed_Object (Entity (Obj))) | |
9474aa9c | 1396 | and then Nkind (Renamed_Object (Entity (Obj))) = |
1397 | N_Explicit_Dereference); | |
7be5088a | 1398 | end Denotes_Explicit_Dereference; |
1399 | ||
ee6ba406 | 1400 | ---------------------------------------- |
1401 | -- Is_Aliased_Unconstrained_Component -- | |
1402 | ---------------------------------------- | |
1403 | ||
1404 | function Is_Aliased_Unconstrained_Component return Boolean is | |
1405 | Comp : Entity_Id; | |
1406 | Pref : Node_Id; | |
1407 | ||
1408 | begin | |
1409 | if Nkind (Lhs) /= N_Selected_Component then | |
1410 | return False; | |
1411 | else | |
1412 | Comp := Entity (Selector_Name (Lhs)); | |
1413 | Pref := Prefix (Lhs); | |
1414 | end if; | |
1415 | ||
1416 | if Ekind (Comp) /= E_Component | |
1417 | or else not Is_Aliased (Comp) | |
1418 | then | |
1419 | return False; | |
1420 | end if; | |
1421 | ||
1422 | return not Comes_From_Source (Pref) | |
1423 | and then In_Instance | |
1424 | and then not Is_Constrained (Etype (Comp)); | |
1425 | end Is_Aliased_Unconstrained_Component; | |
1426 | ||
1427 | -- Start of processing for Apply_Discriminant_Check | |
1428 | ||
1429 | begin | |
1430 | if Do_Access then | |
1431 | T_Typ := Designated_Type (Typ); | |
1432 | else | |
1433 | T_Typ := Typ; | |
1434 | end if; | |
1435 | ||
1436 | -- Nothing to do if discriminant checks are suppressed or else no code | |
1437 | -- is to be generated | |
1438 | ||
a33565dd | 1439 | if not Expander_Active |
ee6ba406 | 1440 | or else Discriminant_Checks_Suppressed (T_Typ) |
1441 | then | |
1442 | return; | |
1443 | end if; | |
1444 | ||
feff2f05 | 1445 | -- No discriminant checks necessary for an access when expression is |
1446 | -- statically Null. This is not only an optimization, it is fundamental | |
1447 | -- because otherwise discriminant checks may be generated in init procs | |
1448 | -- for types containing an access to a not-yet-frozen record, causing a | |
1449 | -- deadly forward reference. | |
ee6ba406 | 1450 | |
feff2f05 | 1451 | -- Also, if the expression is of an access type whose designated type is |
1452 | -- incomplete, then the access value must be null and we suppress the | |
1453 | -- check. | |
ee6ba406 | 1454 | |
2af58f67 | 1455 | if Known_Null (N) then |
ee6ba406 | 1456 | return; |
1457 | ||
1458 | elsif Is_Access_Type (S_Typ) then | |
1459 | S_Typ := Designated_Type (S_Typ); | |
1460 | ||
1461 | if Ekind (S_Typ) = E_Incomplete_Type then | |
1462 | return; | |
1463 | end if; | |
1464 | end if; | |
1465 | ||
0577b0b1 | 1466 | -- If an assignment target is present, then we need to generate the |
1467 | -- actual subtype if the target is a parameter or aliased object with | |
1468 | -- an unconstrained nominal subtype. | |
1469 | ||
1470 | -- Ada 2005 (AI-363): For Ada 2005, we limit the building of the actual | |
1471 | -- subtype to the parameter and dereference cases, since other aliased | |
1472 | -- objects are unconstrained (unless the nominal subtype is explicitly | |
7be5088a | 1473 | -- constrained). |
ee6ba406 | 1474 | |
1475 | if Present (Lhs) | |
1476 | and then (Present (Param_Entity (Lhs)) | |
de54c5ab | 1477 | or else (Ada_Version < Ada_2005 |
0577b0b1 | 1478 | and then not Is_Constrained (T_Typ) |
ee6ba406 | 1479 | and then Is_Aliased_View (Lhs) |
0577b0b1 | 1480 | and then not Is_Aliased_Unconstrained_Component) |
de54c5ab | 1481 | or else (Ada_Version >= Ada_2005 |
0577b0b1 | 1482 | and then not Is_Constrained (T_Typ) |
7be5088a | 1483 | and then Denotes_Explicit_Dereference (Lhs) |
0577b0b1 | 1484 | and then Nkind (Original_Node (Lhs)) /= |
1485 | N_Function_Call)) | |
ee6ba406 | 1486 | then |
1487 | T_Typ := Get_Actual_Subtype (Lhs); | |
1488 | end if; | |
1489 | ||
feff2f05 | 1490 | -- Nothing to do if the type is unconstrained (this is the case where |
1491 | -- the actual subtype in the RM sense of N is unconstrained and no check | |
1492 | -- is required). | |
ee6ba406 | 1493 | |
1494 | if not Is_Constrained (T_Typ) then | |
1495 | return; | |
05fcfafb | 1496 | |
1497 | -- Ada 2005: nothing to do if the type is one for which there is a | |
1498 | -- partial view that is constrained. | |
1499 | ||
de54c5ab | 1500 | elsif Ada_Version >= Ada_2005 |
0d78d2d4 | 1501 | and then Object_Type_Has_Constrained_Partial_View |
d41a3f41 | 1502 | (Typ => Base_Type (T_Typ), |
1503 | Scop => Current_Scope) | |
05fcfafb | 1504 | then |
1505 | return; | |
ee6ba406 | 1506 | end if; |
1507 | ||
00f91aef | 1508 | -- Nothing to do if the type is an Unchecked_Union |
1509 | ||
1510 | if Is_Unchecked_Union (Base_Type (T_Typ)) then | |
1511 | return; | |
1512 | end if; | |
1513 | ||
8d11916f | 1514 | -- Suppress checks if the subtypes are the same. The check must be |
feff2f05 | 1515 | -- preserved in an assignment to a formal, because the constraint is |
1516 | -- given by the actual. | |
ee6ba406 | 1517 | |
1518 | if Nkind (Original_Node (N)) /= N_Allocator | |
1519 | and then (No (Lhs) | |
1520 | or else not Is_Entity_Name (Lhs) | |
9dfe12ae | 1521 | or else No (Param_Entity (Lhs))) |
ee6ba406 | 1522 | then |
1523 | if (Etype (N) = Typ | |
1524 | or else (Do_Access and then Designated_Type (Typ) = S_Typ)) | |
1525 | and then not Is_Aliased_View (Lhs) | |
1526 | then | |
1527 | return; | |
1528 | end if; | |
1529 | ||
feff2f05 | 1530 | -- We can also eliminate checks on allocators with a subtype mark that |
1531 | -- coincides with the context type. The context type may be a subtype | |
1532 | -- without a constraint (common case, a generic actual). | |
ee6ba406 | 1533 | |
1534 | elsif Nkind (Original_Node (N)) = N_Allocator | |
1535 | and then Is_Entity_Name (Expression (Original_Node (N))) | |
1536 | then | |
1537 | declare | |
9dfe12ae | 1538 | Alloc_Typ : constant Entity_Id := |
b6341c67 | 1539 | Entity (Expression (Original_Node (N))); |
ee6ba406 | 1540 | |
1541 | begin | |
1542 | if Alloc_Typ = T_Typ | |
1543 | or else (Nkind (Parent (T_Typ)) = N_Subtype_Declaration | |
1544 | and then Is_Entity_Name ( | |
1545 | Subtype_Indication (Parent (T_Typ))) | |
1546 | and then Alloc_Typ = Base_Type (T_Typ)) | |
1547 | ||
1548 | then | |
1549 | return; | |
1550 | end if; | |
1551 | end; | |
1552 | end if; | |
1553 | ||
feff2f05 | 1554 | -- See if we have a case where the types are both constrained, and all |
1555 | -- the constraints are constants. In this case, we can do the check | |
1556 | -- successfully at compile time. | |
ee6ba406 | 1557 | |
8d11916f | 1558 | -- We skip this check for the case where the node is rewritten as |
d7ec9a29 | 1559 | -- an allocator, because it already carries the context subtype, |
1560 | -- and extracting the discriminants from the aggregate is messy. | |
ee6ba406 | 1561 | |
1562 | if Is_Constrained (S_Typ) | |
1563 | and then Nkind (Original_Node (N)) /= N_Allocator | |
1564 | then | |
1565 | declare | |
1566 | DconT : Elmt_Id; | |
1567 | Discr : Entity_Id; | |
1568 | DconS : Elmt_Id; | |
1569 | ItemS : Node_Id; | |
1570 | ItemT : Node_Id; | |
1571 | ||
1572 | begin | |
1573 | -- S_Typ may not have discriminants in the case where it is a | |
feff2f05 | 1574 | -- private type completed by a default discriminated type. In that |
8d11916f | 1575 | -- case, we need to get the constraints from the underlying type. |
feff2f05 | 1576 | -- If the underlying type is unconstrained (i.e. has no default |
1577 | -- discriminants) no check is needed. | |
ee6ba406 | 1578 | |
1579 | if Has_Discriminants (S_Typ) then | |
1580 | Discr := First_Discriminant (S_Typ); | |
1581 | DconS := First_Elmt (Discriminant_Constraint (S_Typ)); | |
1582 | ||
1583 | else | |
1584 | Discr := First_Discriminant (Underlying_Type (S_Typ)); | |
1585 | DconS := | |
1586 | First_Elmt | |
1587 | (Discriminant_Constraint (Underlying_Type (S_Typ))); | |
1588 | ||
1589 | if No (DconS) then | |
1590 | return; | |
1591 | end if; | |
fccb5da7 | 1592 | |
1593 | -- A further optimization: if T_Typ is derived from S_Typ | |
1594 | -- without imposing a constraint, no check is needed. | |
1595 | ||
1596 | if Nkind (Original_Node (Parent (T_Typ))) = | |
1597 | N_Full_Type_Declaration | |
1598 | then | |
1599 | declare | |
5c61a0ff | 1600 | Type_Def : constant Node_Id := |
b6341c67 | 1601 | Type_Definition (Original_Node (Parent (T_Typ))); |
fccb5da7 | 1602 | begin |
1603 | if Nkind (Type_Def) = N_Derived_Type_Definition | |
1604 | and then Is_Entity_Name (Subtype_Indication (Type_Def)) | |
1605 | and then Entity (Subtype_Indication (Type_Def)) = S_Typ | |
1606 | then | |
1607 | return; | |
1608 | end if; | |
1609 | end; | |
1610 | end if; | |
ee6ba406 | 1611 | end if; |
1612 | ||
86594966 | 1613 | -- Constraint may appear in full view of type |
1614 | ||
1615 | if Ekind (T_Typ) = E_Private_Subtype | |
1616 | and then Present (Full_View (T_Typ)) | |
1617 | then | |
d7ec9a29 | 1618 | DconT := |
86594966 | 1619 | First_Elmt (Discriminant_Constraint (Full_View (T_Typ))); |
86594966 | 1620 | else |
d7ec9a29 | 1621 | DconT := |
1622 | First_Elmt (Discriminant_Constraint (T_Typ)); | |
86594966 | 1623 | end if; |
ee6ba406 | 1624 | |
1625 | while Present (Discr) loop | |
1626 | ItemS := Node (DconS); | |
1627 | ItemT := Node (DconT); | |
1628 | ||
00c403ee | 1629 | -- For a discriminated component type constrained by the |
1630 | -- current instance of an enclosing type, there is no | |
1631 | -- applicable discriminant check. | |
1632 | ||
1633 | if Nkind (ItemT) = N_Attribute_Reference | |
1634 | and then Is_Access_Type (Etype (ItemT)) | |
1635 | and then Is_Entity_Name (Prefix (ItemT)) | |
1636 | and then Is_Type (Entity (Prefix (ItemT))) | |
1637 | then | |
1638 | return; | |
1639 | end if; | |
1640 | ||
cc60bd16 | 1641 | -- If the expressions for the discriminants are identical |
1642 | -- and it is side-effect free (for now just an entity), | |
1643 | -- this may be a shared constraint, e.g. from a subtype | |
1644 | -- without a constraint introduced as a generic actual. | |
1645 | -- Examine other discriminants if any. | |
1646 | ||
1647 | if ItemS = ItemT | |
1648 | and then Is_Entity_Name (ItemS) | |
1649 | then | |
1650 | null; | |
1651 | ||
1652 | elsif not Is_OK_Static_Expression (ItemS) | |
1653 | or else not Is_OK_Static_Expression (ItemT) | |
1654 | then | |
1655 | exit; | |
ee6ba406 | 1656 | |
cc60bd16 | 1657 | elsif Expr_Value (ItemS) /= Expr_Value (ItemT) then |
ee6ba406 | 1658 | if Do_Access then -- needs run-time check. |
1659 | exit; | |
1660 | else | |
1661 | Apply_Compile_Time_Constraint_Error | |
cb97ae5c | 1662 | (N, "incorrect value for discriminant&??", |
f15731c4 | 1663 | CE_Discriminant_Check_Failed, Ent => Discr); |
ee6ba406 | 1664 | return; |
1665 | end if; | |
1666 | end if; | |
1667 | ||
1668 | Next_Elmt (DconS); | |
1669 | Next_Elmt (DconT); | |
1670 | Next_Discriminant (Discr); | |
1671 | end loop; | |
1672 | ||
1673 | if No (Discr) then | |
1674 | return; | |
1675 | end if; | |
1676 | end; | |
1677 | end if; | |
1678 | ||
1679 | -- Here we need a discriminant check. First build the expression | |
1680 | -- for the comparisons of the discriminants: | |
1681 | ||
1682 | -- (n.disc1 /= typ.disc1) or else | |
1683 | -- (n.disc2 /= typ.disc2) or else | |
1684 | -- ... | |
1685 | -- (n.discn /= typ.discn) | |
1686 | ||
1687 | Cond := Build_Discriminant_Checks (N, T_Typ); | |
1688 | ||
3cce7f32 | 1689 | -- If Lhs is set and is a parameter, then the condition is guarded by: |
1690 | -- lhs'constrained and then (condition built above) | |
ee6ba406 | 1691 | |
1692 | if Present (Param_Entity (Lhs)) then | |
1693 | Cond := | |
1694 | Make_And_Then (Loc, | |
1695 | Left_Opnd => | |
1696 | Make_Attribute_Reference (Loc, | |
1697 | Prefix => New_Occurrence_Of (Param_Entity (Lhs), Loc), | |
1698 | Attribute_Name => Name_Constrained), | |
1699 | Right_Opnd => Cond); | |
1700 | end if; | |
1701 | ||
1702 | if Do_Access then | |
1703 | Cond := Guard_Access (Cond, Loc, N); | |
1704 | end if; | |
1705 | ||
1706 | Insert_Action (N, | |
f15731c4 | 1707 | Make_Raise_Constraint_Error (Loc, |
1708 | Condition => Cond, | |
1709 | Reason => CE_Discriminant_Check_Failed)); | |
ee6ba406 | 1710 | end Apply_Discriminant_Check; |
1711 | ||
2fe22c69 | 1712 | ------------------------- |
1713 | -- Apply_Divide_Checks -- | |
1714 | ------------------------- | |
ee6ba406 | 1715 | |
2fe22c69 | 1716 | procedure Apply_Divide_Checks (N : Node_Id) is |
ee6ba406 | 1717 | Loc : constant Source_Ptr := Sloc (N); |
1718 | Typ : constant Entity_Id := Etype (N); | |
1719 | Left : constant Node_Id := Left_Opnd (N); | |
1720 | Right : constant Node_Id := Right_Opnd (N); | |
1721 | ||
db415383 | 1722 | Mode : constant Overflow_Mode_Type := Overflow_Check_Mode; |
2fe22c69 | 1723 | -- Current overflow checking mode |
1724 | ||
ee6ba406 | 1725 | LLB : Uint; |
1726 | Llo : Uint; | |
1727 | Lhi : Uint; | |
1728 | LOK : Boolean; | |
1729 | Rlo : Uint; | |
1730 | Rhi : Uint; | |
2fe22c69 | 1731 | ROK : Boolean; |
96da3284 | 1732 | |
1733 | pragma Warnings (Off, Lhi); | |
1734 | -- Don't actually use this value | |
ee6ba406 | 1735 | |
1736 | begin | |
0df9d43f | 1737 | -- If we are operating in MINIMIZED or ELIMINATED mode, and we are |
1738 | -- operating on signed integer types, then the only thing this routine | |
1739 | -- does is to call Apply_Arithmetic_Overflow_Minimized_Eliminated. That | |
1740 | -- procedure will (possibly later on during recursive downward calls), | |
1741 | -- ensure that any needed overflow/division checks are properly applied. | |
2fe22c69 | 1742 | |
1743 | if Mode in Minimized_Or_Eliminated | |
2fe22c69 | 1744 | and then Is_Signed_Integer_Type (Typ) |
1745 | then | |
1746 | Apply_Arithmetic_Overflow_Minimized_Eliminated (N); | |
1747 | return; | |
1748 | end if; | |
1749 | ||
1750 | -- Proceed here in SUPPRESSED or CHECKED modes | |
1751 | ||
a33565dd | 1752 | if Expander_Active |
13dbf220 | 1753 | and then not Backend_Divide_Checks_On_Target |
1754 | and then Check_Needed (Right, Division_Check) | |
ee6ba406 | 1755 | then |
9c486805 | 1756 | Determine_Range (Right, ROK, Rlo, Rhi, Assume_Valid => True); |
ee6ba406 | 1757 | |
2fe22c69 | 1758 | -- Deal with division check |
ee6ba406 | 1759 | |
2fe22c69 | 1760 | if Do_Division_Check (N) |
1761 | and then not Division_Checks_Suppressed (Typ) | |
1762 | then | |
1763 | Apply_Division_Check (N, Rlo, Rhi, ROK); | |
ee6ba406 | 1764 | end if; |
1765 | ||
2fe22c69 | 1766 | -- Deal with overflow check |
1767 | ||
0df9d43f | 1768 | if Do_Overflow_Check (N) |
1769 | and then not Overflow_Checks_Suppressed (Etype (N)) | |
1770 | then | |
2fe22c69 | 1771 | |
1772 | -- Test for extremely annoying case of xxx'First divided by -1 | |
1773 | -- for division of signed integer types (only overflow case). | |
ee6ba406 | 1774 | |
ee6ba406 | 1775 | if Nkind (N) = N_Op_Divide |
1776 | and then Is_Signed_Integer_Type (Typ) | |
1777 | then | |
9c486805 | 1778 | Determine_Range (Left, LOK, Llo, Lhi, Assume_Valid => True); |
ee6ba406 | 1779 | LLB := Expr_Value (Type_Low_Bound (Base_Type (Typ))); |
1780 | ||
1781 | if ((not ROK) or else (Rlo <= (-1) and then (-1) <= Rhi)) | |
2fe22c69 | 1782 | and then |
1783 | ((not LOK) or else (Llo = LLB)) | |
ee6ba406 | 1784 | then |
1785 | Insert_Action (N, | |
1786 | Make_Raise_Constraint_Error (Loc, | |
1787 | Condition => | |
1788 | Make_And_Then (Loc, | |
2fe22c69 | 1789 | Left_Opnd => |
1790 | Make_Op_Eq (Loc, | |
1791 | Left_Opnd => | |
1792 | Duplicate_Subexpr_Move_Checks (Left), | |
1793 | Right_Opnd => Make_Integer_Literal (Loc, LLB)), | |
ee6ba406 | 1794 | |
2fe22c69 | 1795 | Right_Opnd => |
1796 | Make_Op_Eq (Loc, | |
1797 | Left_Opnd => Duplicate_Subexpr (Right), | |
1798 | Right_Opnd => Make_Integer_Literal (Loc, -1))), | |
ee6ba406 | 1799 | |
f15731c4 | 1800 | Reason => CE_Overflow_Check_Failed)); |
ee6ba406 | 1801 | end if; |
1802 | end if; | |
1803 | end if; | |
1804 | end if; | |
2fe22c69 | 1805 | end Apply_Divide_Checks; |
1806 | ||
1807 | -------------------------- | |
1808 | -- Apply_Division_Check -- | |
1809 | -------------------------- | |
1810 | ||
1811 | procedure Apply_Division_Check | |
1812 | (N : Node_Id; | |
1813 | Rlo : Uint; | |
1814 | Rhi : Uint; | |
1815 | ROK : Boolean) | |
1816 | is | |
1817 | pragma Assert (Do_Division_Check (N)); | |
1818 | ||
1819 | Loc : constant Source_Ptr := Sloc (N); | |
1820 | Right : constant Node_Id := Right_Opnd (N); | |
1821 | ||
1822 | begin | |
a33565dd | 1823 | if Expander_Active |
2fe22c69 | 1824 | and then not Backend_Divide_Checks_On_Target |
1825 | and then Check_Needed (Right, Division_Check) | |
1826 | then | |
1827 | -- See if division by zero possible, and if so generate test. This | |
1828 | -- part of the test is not controlled by the -gnato switch, since | |
1829 | -- it is a Division_Check and not an Overflow_Check. | |
1830 | ||
1831 | if Do_Division_Check (N) then | |
1832 | if (not ROK) or else (Rlo <= 0 and then 0 <= Rhi) then | |
1833 | Insert_Action (N, | |
1834 | Make_Raise_Constraint_Error (Loc, | |
1835 | Condition => | |
1836 | Make_Op_Eq (Loc, | |
1837 | Left_Opnd => Duplicate_Subexpr_Move_Checks (Right), | |
1838 | Right_Opnd => Make_Integer_Literal (Loc, 0)), | |
1839 | Reason => CE_Divide_By_Zero)); | |
1840 | end if; | |
1841 | end if; | |
1842 | end if; | |
1843 | end Apply_Division_Check; | |
ee6ba406 | 1844 | |
5329ca64 | 1845 | ---------------------------------- |
1846 | -- Apply_Float_Conversion_Check -- | |
1847 | ---------------------------------- | |
1848 | ||
feff2f05 | 1849 | -- Let F and I be the source and target types of the conversion. The RM |
1850 | -- specifies that a floating-point value X is rounded to the nearest | |
1851 | -- integer, with halfway cases being rounded away from zero. The rounded | |
1852 | -- value of X is checked against I'Range. | |
1853 | ||
1854 | -- The catch in the above paragraph is that there is no good way to know | |
1855 | -- whether the round-to-integer operation resulted in overflow. A remedy is | |
1856 | -- to perform a range check in the floating-point domain instead, however: | |
5329ca64 | 1857 | |
5329ca64 | 1858 | -- (1) The bounds may not be known at compile time |
2af58f67 | 1859 | -- (2) The check must take into account rounding or truncation. |
5329ca64 | 1860 | -- (3) The range of type I may not be exactly representable in F. |
2af58f67 | 1861 | -- (4) For the rounding case, The end-points I'First - 0.5 and |
1862 | -- I'Last + 0.5 may or may not be in range, depending on the | |
1863 | -- sign of I'First and I'Last. | |
5329ca64 | 1864 | -- (5) X may be a NaN, which will fail any comparison |
1865 | ||
2af58f67 | 1866 | -- The following steps correctly convert X with rounding: |
feff2f05 | 1867 | |
5329ca64 | 1868 | -- (1) If either I'First or I'Last is not known at compile time, use |
1869 | -- I'Base instead of I in the next three steps and perform a | |
1870 | -- regular range check against I'Range after conversion. | |
1871 | -- (2) If I'First - 0.5 is representable in F then let Lo be that | |
1872 | -- value and define Lo_OK as (I'First > 0). Otherwise, let Lo be | |
2af58f67 | 1873 | -- F'Machine (I'First) and let Lo_OK be (Lo >= I'First). |
1874 | -- In other words, take one of the closest floating-point numbers | |
1875 | -- (which is an integer value) to I'First, and see if it is in | |
1876 | -- range or not. | |
5329ca64 | 1877 | -- (3) If I'Last + 0.5 is representable in F then let Hi be that value |
1878 | -- and define Hi_OK as (I'Last < 0). Otherwise, let Hi be | |
2af58f67 | 1879 | -- F'Machine (I'Last) and let Hi_OK be (Hi <= I'Last). |
5329ca64 | 1880 | -- (4) Raise CE when (Lo_OK and X < Lo) or (not Lo_OK and X <= Lo) |
1881 | -- or (Hi_OK and X > Hi) or (not Hi_OK and X >= Hi) | |
1882 | ||
2af58f67 | 1883 | -- For the truncating case, replace steps (2) and (3) as follows: |
1884 | -- (2) If I'First > 0, then let Lo be F'Pred (I'First) and let Lo_OK | |
1885 | -- be False. Otherwise, let Lo be F'Succ (I'First - 1) and let | |
1886 | -- Lo_OK be True. | |
1887 | -- (3) If I'Last < 0, then let Hi be F'Succ (I'Last) and let Hi_OK | |
1888 | -- be False. Otherwise let Hi be F'Pred (I'Last + 1) and let | |
141d591a | 1889 | -- Hi_OK be True. |
2af58f67 | 1890 | |
5329ca64 | 1891 | procedure Apply_Float_Conversion_Check |
1892 | (Ck_Node : Node_Id; | |
1893 | Target_Typ : Entity_Id) | |
1894 | is | |
feff2f05 | 1895 | LB : constant Node_Id := Type_Low_Bound (Target_Typ); |
1896 | HB : constant Node_Id := Type_High_Bound (Target_Typ); | |
5329ca64 | 1897 | Loc : constant Source_Ptr := Sloc (Ck_Node); |
1898 | Expr_Type : constant Entity_Id := Base_Type (Etype (Ck_Node)); | |
feff2f05 | 1899 | Target_Base : constant Entity_Id := |
b6341c67 | 1900 | Implementation_Base_Type (Target_Typ); |
feff2f05 | 1901 | |
2af58f67 | 1902 | Par : constant Node_Id := Parent (Ck_Node); |
1903 | pragma Assert (Nkind (Par) = N_Type_Conversion); | |
1904 | -- Parent of check node, must be a type conversion | |
1905 | ||
1906 | Truncate : constant Boolean := Float_Truncate (Par); | |
1907 | Max_Bound : constant Uint := | |
b6341c67 | 1908 | UI_Expon |
1909 | (Machine_Radix_Value (Expr_Type), | |
1910 | Machine_Mantissa_Value (Expr_Type) - 1) - 1; | |
2af58f67 | 1911 | |
5329ca64 | 1912 | -- Largest bound, so bound plus or minus half is a machine number of F |
1913 | ||
feff2f05 | 1914 | Ifirst, Ilast : Uint; |
1915 | -- Bounds of integer type | |
1916 | ||
1917 | Lo, Hi : Ureal; | |
1918 | -- Bounds to check in floating-point domain | |
5329ca64 | 1919 | |
feff2f05 | 1920 | Lo_OK, Hi_OK : Boolean; |
1921 | -- True iff Lo resp. Hi belongs to I'Range | |
5329ca64 | 1922 | |
feff2f05 | 1923 | Lo_Chk, Hi_Chk : Node_Id; |
1924 | -- Expressions that are False iff check fails | |
1925 | ||
1926 | Reason : RT_Exception_Code; | |
5329ca64 | 1927 | |
1928 | begin | |
41f06abf | 1929 | -- We do not need checks if we are not generating code (i.e. the full |
1930 | -- expander is not active). In SPARK mode, we specifically don't want | |
1931 | -- the frontend to expand these checks, which are dealt with directly | |
1932 | -- in the formal verification backend. | |
1933 | ||
a33565dd | 1934 | if not Expander_Active then |
41f06abf | 1935 | return; |
1936 | end if; | |
1937 | ||
5329ca64 | 1938 | if not Compile_Time_Known_Value (LB) |
1939 | or not Compile_Time_Known_Value (HB) | |
1940 | then | |
1941 | declare | |
feff2f05 | 1942 | -- First check that the value falls in the range of the base type, |
1943 | -- to prevent overflow during conversion and then perform a | |
1944 | -- regular range check against the (dynamic) bounds. | |
5329ca64 | 1945 | |
5329ca64 | 1946 | pragma Assert (Target_Base /= Target_Typ); |
5329ca64 | 1947 | |
46eb6933 | 1948 | Temp : constant Entity_Id := Make_Temporary (Loc, 'T', Par); |
5329ca64 | 1949 | |
1950 | begin | |
1951 | Apply_Float_Conversion_Check (Ck_Node, Target_Base); | |
1952 | Set_Etype (Temp, Target_Base); | |
1953 | ||
1954 | Insert_Action (Parent (Par), | |
1955 | Make_Object_Declaration (Loc, | |
1956 | Defining_Identifier => Temp, | |
1957 | Object_Definition => New_Occurrence_Of (Target_Typ, Loc), | |
1958 | Expression => New_Copy_Tree (Par)), | |
1959 | Suppress => All_Checks); | |
1960 | ||
1961 | Insert_Action (Par, | |
1962 | Make_Raise_Constraint_Error (Loc, | |
1963 | Condition => | |
1964 | Make_Not_In (Loc, | |
1965 | Left_Opnd => New_Occurrence_Of (Temp, Loc), | |
1966 | Right_Opnd => New_Occurrence_Of (Target_Typ, Loc)), | |
1967 | Reason => CE_Range_Check_Failed)); | |
1968 | Rewrite (Par, New_Occurrence_Of (Temp, Loc)); | |
1969 | ||
1970 | return; | |
1971 | end; | |
1972 | end if; | |
1973 | ||
7d86aa98 | 1974 | -- Get the (static) bounds of the target type |
5329ca64 | 1975 | |
1976 | Ifirst := Expr_Value (LB); | |
1977 | Ilast := Expr_Value (HB); | |
1978 | ||
7d86aa98 | 1979 | -- A simple optimization: if the expression is a universal literal, |
1980 | -- we can do the comparison with the bounds and the conversion to | |
1981 | -- an integer type statically. The range checks are unchanged. | |
1982 | ||
1983 | if Nkind (Ck_Node) = N_Real_Literal | |
1984 | and then Etype (Ck_Node) = Universal_Real | |
1985 | and then Is_Integer_Type (Target_Typ) | |
1986 | and then Nkind (Parent (Ck_Node)) = N_Type_Conversion | |
1987 | then | |
1988 | declare | |
1989 | Int_Val : constant Uint := UR_To_Uint (Realval (Ck_Node)); | |
1990 | ||
1991 | begin | |
1992 | if Int_Val <= Ilast and then Int_Val >= Ifirst then | |
1993 | ||
4309515d | 1994 | -- Conversion is safe |
7d86aa98 | 1995 | |
1996 | Rewrite (Parent (Ck_Node), | |
1997 | Make_Integer_Literal (Loc, UI_To_Int (Int_Val))); | |
1998 | Analyze_And_Resolve (Parent (Ck_Node), Target_Typ); | |
1999 | return; | |
2000 | end if; | |
2001 | end; | |
2002 | end if; | |
2003 | ||
5329ca64 | 2004 | -- Check against lower bound |
2005 | ||
2af58f67 | 2006 | if Truncate and then Ifirst > 0 then |
2007 | Lo := Pred (Expr_Type, UR_From_Uint (Ifirst)); | |
2008 | Lo_OK := False; | |
2009 | ||
2010 | elsif Truncate then | |
2011 | Lo := Succ (Expr_Type, UR_From_Uint (Ifirst - 1)); | |
2012 | Lo_OK := True; | |
2013 | ||
2014 | elsif abs (Ifirst) < Max_Bound then | |
5329ca64 | 2015 | Lo := UR_From_Uint (Ifirst) - Ureal_Half; |
2016 | Lo_OK := (Ifirst > 0); | |
2af58f67 | 2017 | |
5329ca64 | 2018 | else |
2019 | Lo := Machine (Expr_Type, UR_From_Uint (Ifirst), Round_Even, Ck_Node); | |
2020 | Lo_OK := (Lo >= UR_From_Uint (Ifirst)); | |
2021 | end if; | |
2022 | ||
2023 | if Lo_OK then | |
2024 | ||
2025 | -- Lo_Chk := (X >= Lo) | |
2026 | ||
2027 | Lo_Chk := Make_Op_Ge (Loc, | |
2028 | Left_Opnd => Duplicate_Subexpr_No_Checks (Ck_Node), | |
2029 | Right_Opnd => Make_Real_Literal (Loc, Lo)); | |
2030 | ||
2031 | else | |
2032 | -- Lo_Chk := (X > Lo) | |
2033 | ||
2034 | Lo_Chk := Make_Op_Gt (Loc, | |
2035 | Left_Opnd => Duplicate_Subexpr_No_Checks (Ck_Node), | |
2036 | Right_Opnd => Make_Real_Literal (Loc, Lo)); | |
2037 | end if; | |
2038 | ||
2039 | -- Check against higher bound | |
2040 | ||
2af58f67 | 2041 | if Truncate and then Ilast < 0 then |
2042 | Hi := Succ (Expr_Type, UR_From_Uint (Ilast)); | |
b2c42753 | 2043 | Hi_OK := False; |
2af58f67 | 2044 | |
2045 | elsif Truncate then | |
2046 | Hi := Pred (Expr_Type, UR_From_Uint (Ilast + 1)); | |
2047 | Hi_OK := True; | |
2048 | ||
2049 | elsif abs (Ilast) < Max_Bound then | |
5329ca64 | 2050 | Hi := UR_From_Uint (Ilast) + Ureal_Half; |
2051 | Hi_OK := (Ilast < 0); | |
2052 | else | |
2053 | Hi := Machine (Expr_Type, UR_From_Uint (Ilast), Round_Even, Ck_Node); | |
2054 | Hi_OK := (Hi <= UR_From_Uint (Ilast)); | |
2055 | end if; | |
2056 | ||
2057 | if Hi_OK then | |
2058 | ||
2059 | -- Hi_Chk := (X <= Hi) | |
2060 | ||
2061 | Hi_Chk := Make_Op_Le (Loc, | |
2062 | Left_Opnd => Duplicate_Subexpr_No_Checks (Ck_Node), | |
2063 | Right_Opnd => Make_Real_Literal (Loc, Hi)); | |
2064 | ||
2065 | else | |
2066 | -- Hi_Chk := (X < Hi) | |
2067 | ||
2068 | Hi_Chk := Make_Op_Lt (Loc, | |
2069 | Left_Opnd => Duplicate_Subexpr_No_Checks (Ck_Node), | |
2070 | Right_Opnd => Make_Real_Literal (Loc, Hi)); | |
2071 | end if; | |
2072 | ||
feff2f05 | 2073 | -- If the bounds of the target type are the same as those of the base |
2074 | -- type, the check is an overflow check as a range check is not | |
2075 | -- performed in these cases. | |
5329ca64 | 2076 | |
2077 | if Expr_Value (Type_Low_Bound (Target_Base)) = Ifirst | |
2078 | and then Expr_Value (Type_High_Bound (Target_Base)) = Ilast | |
2079 | then | |
2080 | Reason := CE_Overflow_Check_Failed; | |
2081 | else | |
2082 | Reason := CE_Range_Check_Failed; | |
2083 | end if; | |
2084 | ||
2085 | -- Raise CE if either conditions does not hold | |
2086 | ||
2087 | Insert_Action (Ck_Node, | |
2088 | Make_Raise_Constraint_Error (Loc, | |
05fcfafb | 2089 | Condition => Make_Op_Not (Loc, Make_And_Then (Loc, Lo_Chk, Hi_Chk)), |
5329ca64 | 2090 | Reason => Reason)); |
2091 | end Apply_Float_Conversion_Check; | |
2092 | ||
ee6ba406 | 2093 | ------------------------ |
2094 | -- Apply_Length_Check -- | |
2095 | ------------------------ | |
2096 | ||
2097 | procedure Apply_Length_Check | |
2098 | (Ck_Node : Node_Id; | |
2099 | Target_Typ : Entity_Id; | |
2100 | Source_Typ : Entity_Id := Empty) | |
2101 | is | |
2102 | begin | |
2103 | Apply_Selected_Length_Checks | |
2104 | (Ck_Node, Target_Typ, Source_Typ, Do_Static => False); | |
2105 | end Apply_Length_Check; | |
2106 | ||
3b045963 | 2107 | ------------------------------------- |
2108 | -- Apply_Parameter_Aliasing_Checks -- | |
2109 | ------------------------------------- | |
b73adb97 | 2110 | |
3b045963 | 2111 | procedure Apply_Parameter_Aliasing_Checks |
2112 | (Call : Node_Id; | |
2113 | Subp : Entity_Id) | |
2114 | is | |
bb569db0 | 2115 | Loc : constant Source_Ptr := Sloc (Call); |
2116 | ||
3b045963 | 2117 | function May_Cause_Aliasing |
2118 | (Formal_1 : Entity_Id; | |
2119 | Formal_2 : Entity_Id) return Boolean; | |
2120 | -- Determine whether two formal parameters can alias each other | |
2121 | -- depending on their modes. | |
2122 | ||
2123 | function Original_Actual (N : Node_Id) return Node_Id; | |
2124 | -- The expander may replace an actual with a temporary for the sake of | |
2125 | -- side effect removal. The temporary may hide a potential aliasing as | |
2126 | -- it does not share the address of the actual. This routine attempts | |
2127 | -- to retrieve the original actual. | |
2128 | ||
bb569db0 | 2129 | procedure Overlap_Check |
2130 | (Actual_1 : Node_Id; | |
2131 | Actual_2 : Node_Id; | |
2132 | Formal_1 : Entity_Id; | |
2133 | Formal_2 : Entity_Id; | |
2134 | Check : in out Node_Id); | |
2135 | -- Create a check to determine whether Actual_1 overlaps with Actual_2. | |
2136 | -- If detailed exception messages are enabled, the check is augmented to | |
2137 | -- provide information about the names of the corresponding formals. See | |
2138 | -- the body for details. Actual_1 and Actual_2 denote the two actuals to | |
2139 | -- be tested. Formal_1 and Formal_2 denote the corresponding formals. | |
2140 | -- Check contains all and-ed simple tests generated so far or remains | |
2141 | -- unchanged in the case of detailed exception messaged. | |
2142 | ||
3b045963 | 2143 | ------------------------ |
2144 | -- May_Cause_Aliasing -- | |
2145 | ------------------------ | |
b73adb97 | 2146 | |
3b045963 | 2147 | function May_Cause_Aliasing |
4a9e7f0c | 2148 | (Formal_1 : Entity_Id; |
3b045963 | 2149 | Formal_2 : Entity_Id) return Boolean |
2150 | is | |
2151 | begin | |
2152 | -- The following combination cannot lead to aliasing | |
2153 | ||
2154 | -- Formal 1 Formal 2 | |
2155 | -- IN IN | |
2156 | ||
2157 | if Ekind (Formal_1) = E_In_Parameter | |
a45d946f | 2158 | and then |
2159 | Ekind (Formal_2) = E_In_Parameter | |
3b045963 | 2160 | then |
2161 | return False; | |
2162 | ||
2163 | -- The following combinations may lead to aliasing | |
2164 | ||
2165 | -- Formal 1 Formal 2 | |
2166 | -- IN OUT | |
2167 | -- IN IN OUT | |
2168 | -- OUT IN | |
2169 | -- OUT IN OUT | |
2170 | -- OUT OUT | |
2171 | ||
2172 | else | |
2173 | return True; | |
2174 | end if; | |
2175 | end May_Cause_Aliasing; | |
2176 | ||
2177 | --------------------- | |
2178 | -- Original_Actual -- | |
2179 | --------------------- | |
2180 | ||
2181 | function Original_Actual (N : Node_Id) return Node_Id is | |
2182 | begin | |
2183 | if Nkind (N) = N_Type_Conversion then | |
2184 | return Expression (N); | |
2185 | ||
2186 | -- The expander created a temporary to capture the result of a type | |
2187 | -- conversion where the expression is the real actual. | |
2188 | ||
2189 | elsif Nkind (N) = N_Identifier | |
2190 | and then Present (Original_Node (N)) | |
2191 | and then Nkind (Original_Node (N)) = N_Type_Conversion | |
2192 | then | |
2193 | return Expression (Original_Node (N)); | |
2194 | end if; | |
2195 | ||
2196 | return N; | |
2197 | end Original_Actual; | |
2198 | ||
bb569db0 | 2199 | ------------------- |
2200 | -- Overlap_Check -- | |
2201 | ------------------- | |
2202 | ||
2203 | procedure Overlap_Check | |
2204 | (Actual_1 : Node_Id; | |
2205 | Actual_2 : Node_Id; | |
2206 | Formal_1 : Entity_Id; | |
2207 | Formal_2 : Entity_Id; | |
2208 | Check : in out Node_Id) | |
2209 | is | |
29448168 | 2210 | Cond : Node_Id; |
2211 | ID_Casing : constant Casing_Type := | |
2212 | Identifier_Casing (Source_Index (Current_Sem_Unit)); | |
bb569db0 | 2213 | |
2214 | begin | |
2215 | -- Generate: | |
2216 | -- Actual_1'Overlaps_Storage (Actual_2) | |
2217 | ||
2218 | Cond := | |
2219 | Make_Attribute_Reference (Loc, | |
2220 | Prefix => New_Copy_Tree (Original_Actual (Actual_1)), | |
2221 | Attribute_Name => Name_Overlaps_Storage, | |
2222 | Expressions => | |
2223 | New_List (New_Copy_Tree (Original_Actual (Actual_2)))); | |
2224 | ||
2225 | -- Generate the following check when detailed exception messages are | |
2226 | -- enabled: | |
2227 | ||
2228 | -- if Actual_1'Overlaps_Storage (Actual_2) then | |
2229 | -- raise Program_Error with <detailed message>; | |
2230 | -- end if; | |
2231 | ||
2232 | if Exception_Extra_Info then | |
2233 | Start_String; | |
2234 | ||
2235 | -- Do not generate location information for internal calls | |
2236 | ||
2237 | if Comes_From_Source (Call) then | |
2238 | Store_String_Chars (Build_Location_String (Loc)); | |
2239 | Store_String_Char (' '); | |
2240 | end if; | |
2241 | ||
2242 | Store_String_Chars ("aliased parameters, actuals for """); | |
29448168 | 2243 | |
2244 | Get_Name_String (Chars (Formal_1)); | |
2245 | Set_Casing (ID_Casing); | |
2246 | Store_String_Chars (Name_Buffer (1 .. Name_Len)); | |
2247 | ||
bb569db0 | 2248 | Store_String_Chars (""" and """); |
29448168 | 2249 | |
2250 | Get_Name_String (Chars (Formal_2)); | |
2251 | Set_Casing (ID_Casing); | |
2252 | Store_String_Chars (Name_Buffer (1 .. Name_Len)); | |
2253 | ||
bb569db0 | 2254 | Store_String_Chars (""" overlap"); |
2255 | ||
2256 | Insert_Action (Call, | |
2257 | Make_If_Statement (Loc, | |
2258 | Condition => Cond, | |
2259 | Then_Statements => New_List ( | |
2260 | Make_Raise_Statement (Loc, | |
2261 | Name => | |
2262 | New_Reference_To (Standard_Program_Error, Loc), | |
2263 | Expression => Make_String_Literal (Loc, End_String))))); | |
2264 | ||
2265 | -- Create a sequence of overlapping checks by and-ing them all | |
2266 | -- together. | |
2267 | ||
2268 | else | |
2269 | if No (Check) then | |
2270 | Check := Cond; | |
2271 | else | |
2272 | Check := | |
2273 | Make_And_Then (Loc, | |
2274 | Left_Opnd => Check, | |
2275 | Right_Opnd => Cond); | |
2276 | end if; | |
2277 | end if; | |
2278 | end Overlap_Check; | |
2279 | ||
3b045963 | 2280 | -- Local variables |
2281 | ||
3b045963 | 2282 | Actual_1 : Node_Id; |
2283 | Actual_2 : Node_Id; | |
2284 | Check : Node_Id; | |
3b045963 | 2285 | Formal_1 : Entity_Id; |
2286 | Formal_2 : Entity_Id; | |
2287 | ||
2288 | -- Start of processing for Apply_Parameter_Aliasing_Checks | |
2289 | ||
2290 | begin | |
bb569db0 | 2291 | Check := Empty; |
3b045963 | 2292 | |
2293 | Actual_1 := First_Actual (Call); | |
2294 | Formal_1 := First_Formal (Subp); | |
2295 | while Present (Actual_1) and then Present (Formal_1) loop | |
2296 | ||
2297 | -- Ensure that the actual is an object that is not passed by value. | |
2298 | -- Elementary types are always passed by value, therefore actuals of | |
2299 | -- such types cannot lead to aliasing. | |
2300 | ||
2301 | if Is_Object_Reference (Original_Actual (Actual_1)) | |
2302 | and then not Is_Elementary_Type (Etype (Original_Actual (Actual_1))) | |
2303 | then | |
2304 | Actual_2 := Next_Actual (Actual_1); | |
2305 | Formal_2 := Next_Formal (Formal_1); | |
2306 | while Present (Actual_2) and then Present (Formal_2) loop | |
2307 | ||
2308 | -- The other actual we are testing against must also denote | |
2309 | -- a non pass-by-value object. Generate the check only when | |
2310 | -- the mode of the two formals may lead to aliasing. | |
2311 | ||
2312 | if Is_Object_Reference (Original_Actual (Actual_2)) | |
2313 | and then not | |
2314 | Is_Elementary_Type (Etype (Original_Actual (Actual_2))) | |
2315 | and then May_Cause_Aliasing (Formal_1, Formal_2) | |
2316 | then | |
bb569db0 | 2317 | Overlap_Check |
2318 | (Actual_1 => Actual_1, | |
2319 | Actual_2 => Actual_2, | |
2320 | Formal_1 => Formal_1, | |
2321 | Formal_2 => Formal_2, | |
2322 | Check => Check); | |
3b045963 | 2323 | end if; |
2324 | ||
2325 | Next_Actual (Actual_2); | |
2326 | Next_Formal (Formal_2); | |
2327 | end loop; | |
2328 | end if; | |
2329 | ||
2330 | Next_Actual (Actual_1); | |
2331 | Next_Formal (Formal_1); | |
2332 | end loop; | |
2333 | ||
bb569db0 | 2334 | -- Place a simple check right before the call |
3b045963 | 2335 | |
bb569db0 | 2336 | if Present (Check) and then not Exception_Extra_Info then |
3b045963 | 2337 | Insert_Action (Call, |
2338 | Make_Raise_Program_Error (Loc, | |
bb569db0 | 2339 | Condition => Check, |
2340 | Reason => PE_Aliased_Parameters)); | |
3b045963 | 2341 | end if; |
2342 | end Apply_Parameter_Aliasing_Checks; | |
2343 | ||
2344 | ------------------------------------- | |
2345 | -- Apply_Parameter_Validity_Checks -- | |
2346 | ------------------------------------- | |
2347 | ||
2348 | procedure Apply_Parameter_Validity_Checks (Subp : Entity_Id) is | |
2349 | Subp_Decl : Node_Id; | |
b73adb97 | 2350 | |
4a9e7f0c | 2351 | procedure Add_Validity_Check |
2352 | (Context : Entity_Id; | |
2353 | PPC_Nam : Name_Id; | |
2354 | For_Result : Boolean := False); | |
2355 | -- Add a single 'Valid[_Scalar] check which verifies the initialization | |
2356 | -- of Context. PPC_Nam denotes the pre or post condition pragma name. | |
2357 | -- Set flag For_Result when to verify the result of a function. | |
b73adb97 | 2358 | |
4a9e7f0c | 2359 | procedure Build_PPC_Pragma (PPC_Nam : Name_Id; Check : Node_Id); |
2360 | -- Create a pre or post condition pragma with name PPC_Nam which | |
2361 | -- tests expression Check. | |
b73adb97 | 2362 | |
b73adb97 | 2363 | ------------------------ |
2364 | -- Add_Validity_Check -- | |
2365 | ------------------------ | |
2366 | ||
2367 | procedure Add_Validity_Check | |
2368 | (Context : Entity_Id; | |
4a9e7f0c | 2369 | PPC_Nam : Name_Id; |
b73adb97 | 2370 | For_Result : Boolean := False) |
2371 | is | |
4a9e7f0c | 2372 | Loc : constant Source_Ptr := Sloc (Subp); |
2373 | Typ : constant Entity_Id := Etype (Context); | |
b73adb97 | 2374 | Check : Node_Id; |
2375 | Nam : Name_Id; | |
2376 | ||
2377 | begin | |
2378 | -- Pick the proper version of 'Valid depending on the type of the | |
2379 | -- context. If the context is not eligible for such a check, return. | |
2380 | ||
2381 | if Is_Scalar_Type (Typ) then | |
2382 | Nam := Name_Valid; | |
2383 | elsif not No_Scalar_Parts (Typ) then | |
2384 | Nam := Name_Valid_Scalars; | |
2385 | else | |
2386 | return; | |
2387 | end if; | |
2388 | ||
2389 | -- Step 1: Create the expression to verify the validity of the | |
2390 | -- context. | |
2391 | ||
2392 | Check := New_Reference_To (Context, Loc); | |
2393 | ||
2394 | -- When processing a function result, use 'Result. Generate | |
2395 | -- Context'Result | |
2396 | ||
2397 | if For_Result then | |
2398 | Check := | |
2399 | Make_Attribute_Reference (Loc, | |
2400 | Prefix => Check, | |
2401 | Attribute_Name => Name_Result); | |
2402 | end if; | |
2403 | ||
2404 | -- Generate: | |
2405 | -- Context['Result]'Valid[_Scalars] | |
2406 | ||
2407 | Check := | |
2408 | Make_Attribute_Reference (Loc, | |
2409 | Prefix => Check, | |
2410 | Attribute_Name => Nam); | |
2411 | ||
4a9e7f0c | 2412 | -- Step 2: Create a pre or post condition pragma |
2413 | ||
2414 | Build_PPC_Pragma (PPC_Nam, Check); | |
2415 | end Add_Validity_Check; | |
2416 | ||
2417 | ---------------------- | |
2418 | -- Build_PPC_Pragma -- | |
2419 | ---------------------- | |
b73adb97 | 2420 | |
4a9e7f0c | 2421 | procedure Build_PPC_Pragma (PPC_Nam : Name_Id; Check : Node_Id) is |
7c443ae8 | 2422 | Loc : constant Source_Ptr := Sloc (Subp); |
2423 | Decls : List_Id; | |
2424 | Prag : Node_Id; | |
4a9e7f0c | 2425 | |
2426 | begin | |
2427 | Prag := | |
2428 | Make_Pragma (Loc, | |
2429 | Pragma_Identifier => Make_Identifier (Loc, PPC_Nam), | |
2430 | Pragma_Argument_Associations => New_List ( | |
2431 | Make_Pragma_Argument_Association (Loc, | |
2432 | Chars => Name_Check, | |
2433 | Expression => Check))); | |
2434 | ||
2435 | -- Add a message unless exception messages are suppressed | |
2436 | ||
2437 | if not Exception_Locations_Suppressed then | |
2438 | Append_To (Pragma_Argument_Associations (Prag), | |
2439 | Make_Pragma_Argument_Association (Loc, | |
2440 | Chars => Name_Message, | |
2441 | Expression => | |
2442 | Make_String_Literal (Loc, | |
2443 | Strval => "failed " & Get_Name_String (PPC_Nam) & | |
2444 | " from " & Build_Location_String (Loc)))); | |
2445 | end if; | |
2446 | ||
2447 | -- Insert the pragma in the tree | |
2448 | ||
2449 | if Nkind (Parent (Subp_Decl)) = N_Compilation_Unit then | |
2450 | Add_Global_Declaration (Prag); | |
7c443ae8 | 2451 | Analyze (Prag); |
2452 | ||
2453 | -- PPC pragmas associated with subprogram bodies must be inserted in | |
2454 | -- the declarative part of the body. | |
2455 | ||
2456 | elsif Nkind (Subp_Decl) = N_Subprogram_Body then | |
2457 | Decls := Declarations (Subp_Decl); | |
2458 | ||
2459 | if No (Decls) then | |
2460 | Decls := New_List; | |
2461 | Set_Declarations (Subp_Decl, Decls); | |
2462 | end if; | |
2463 | ||
1bd93de5 | 2464 | Prepend_To (Decls, Prag); |
7c443ae8 | 2465 | |
2466 | -- Ensure the proper visibility of the subprogram body and its | |
2467 | -- parameters. | |
2468 | ||
2469 | Push_Scope (Subp); | |
2470 | Analyze (Prag); | |
2471 | Pop_Scope; | |
2472 | ||
2473 | -- For subprogram declarations insert the PPC pragma right after the | |
2474 | -- declarative node. | |
2475 | ||
b73adb97 | 2476 | else |
7c443ae8 | 2477 | Insert_After_And_Analyze (Subp_Decl, Prag); |
b73adb97 | 2478 | end if; |
4a9e7f0c | 2479 | end Build_PPC_Pragma; |
2480 | ||
2481 | -- Local variables | |
2482 | ||
2483 | Formal : Entity_Id; | |
4a9e7f0c | 2484 | Subp_Spec : Node_Id; |
2485 | ||
3b045963 | 2486 | -- Start of processing for Apply_Parameter_Validity_Checks |
b73adb97 | 2487 | |
2488 | begin | |
4a9e7f0c | 2489 | -- Extract the subprogram specification and declaration nodes |
b73adb97 | 2490 | |
4a9e7f0c | 2491 | Subp_Spec := Parent (Subp); |
a45d946f | 2492 | |
4a9e7f0c | 2493 | if Nkind (Subp_Spec) = N_Defining_Program_Unit_Name then |
2494 | Subp_Spec := Parent (Subp_Spec); | |
2495 | end if; | |
a45d946f | 2496 | |
4a9e7f0c | 2497 | Subp_Decl := Parent (Subp_Spec); |
9e58d7ed | 2498 | |
b73adb97 | 2499 | if not Comes_From_Source (Subp) |
4a9e7f0c | 2500 | |
2501 | -- Do not process formal subprograms because the corresponding actual | |
2502 | -- will receive the proper checks when the instance is analyzed. | |
2503 | ||
2504 | or else Is_Formal_Subprogram (Subp) | |
2505 | ||
a45d946f | 2506 | -- Do not process imported subprograms since pre and post conditions |
2507 | -- are never verified on routines coming from a different language. | |
4a9e7f0c | 2508 | |
b73adb97 | 2509 | or else Is_Imported (Subp) |
2510 | or else Is_Intrinsic_Subprogram (Subp) | |
4a9e7f0c | 2511 | |
a45d946f | 2512 | -- The PPC pragmas generated by this routine do not correspond to |
2513 | -- source aspects, therefore they cannot be applied to abstract | |
2514 | -- subprograms. | |
4a9e7f0c | 2515 | |
7c443ae8 | 2516 | or else Nkind (Subp_Decl) = N_Abstract_Subprogram_Declaration |
4a9e7f0c | 2517 | |
a45d946f | 2518 | -- Do not consider subprogram renaminds because the renamed entity |
2519 | -- already has the proper PPC pragmas. | |
1bd93de5 | 2520 | |
2521 | or else Nkind (Subp_Decl) = N_Subprogram_Renaming_Declaration | |
2522 | ||
a45d946f | 2523 | -- Do not process null procedures because there is no benefit of |
2524 | -- adding the checks to a no action routine. | |
4a9e7f0c | 2525 | |
2526 | or else (Nkind (Subp_Spec) = N_Procedure_Specification | |
a45d946f | 2527 | and then Null_Present (Subp_Spec)) |
b73adb97 | 2528 | then |
2529 | return; | |
2530 | end if; | |
2531 | ||
4a9e7f0c | 2532 | -- Inspect all the formals applying aliasing and scalar initialization |
2533 | -- checks where applicable. | |
b73adb97 | 2534 | |
2535 | Formal := First_Formal (Subp); | |
2536 | while Present (Formal) loop | |
4a9e7f0c | 2537 | |
2538 | -- Generate the following scalar initialization checks for each | |
2539 | -- formal parameter: | |
2540 | ||
2541 | -- mode IN - Pre => Formal'Valid[_Scalars] | |
2542 | -- mode IN OUT - Pre, Post => Formal'Valid[_Scalars] | |
2543 | -- mode OUT - Post => Formal'Valid[_Scalars] | |
2544 | ||
2545 | if Check_Validity_Of_Parameters then | |
2546 | if Ekind_In (Formal, E_In_Parameter, E_In_Out_Parameter) then | |
2547 | Add_Validity_Check (Formal, Name_Precondition, False); | |
2548 | end if; | |
2549 | ||
2550 | if Ekind_In (Formal, E_In_Out_Parameter, E_Out_Parameter) then | |
2551 | Add_Validity_Check (Formal, Name_Postcondition, False); | |
2552 | end if; | |
b73adb97 | 2553 | end if; |
2554 | ||
b73adb97 | 2555 | Next_Formal (Formal); |
2556 | end loop; | |
2557 | ||
a45d946f | 2558 | -- Generate following scalar initialization check for function result: |
4a9e7f0c | 2559 | |
2560 | -- Post => Subp'Result'Valid[_Scalars] | |
b73adb97 | 2561 | |
a45d946f | 2562 | if Check_Validity_Of_Parameters and then Ekind (Subp) = E_Function then |
4a9e7f0c | 2563 | Add_Validity_Check (Subp, Name_Postcondition, True); |
b73adb97 | 2564 | end if; |
3b045963 | 2565 | end Apply_Parameter_Validity_Checks; |
b73adb97 | 2566 | |
7aafae1c | 2567 | --------------------------- |
2568 | -- Apply_Predicate_Check -- | |
2569 | --------------------------- | |
2570 | ||
2571 | procedure Apply_Predicate_Check (N : Node_Id; Typ : Entity_Id) is | |
301d5ec3 | 2572 | S : Entity_Id; |
9e58d7ed | 2573 | |
7aafae1c | 2574 | begin |
701d57a4 | 2575 | if Present (Predicate_Function (Typ)) then |
301d5ec3 | 2576 | |
2577 | -- A predicate check does not apply within internally generated | |
2578 | -- subprograms, such as TSS functions. | |
2579 | ||
2580 | S := Current_Scope; | |
9e58d7ed | 2581 | while Present (S) and then not Is_Subprogram (S) loop |
301d5ec3 | 2582 | S := Scope (S); |
2583 | end loop; | |
2584 | ||
9e58d7ed | 2585 | if Present (S) and then Get_TSS_Name (S) /= TSS_Null then |
301d5ec3 | 2586 | return; |
22631b41 | 2587 | |
96a2d100 | 2588 | -- If the check appears within the predicate function itself, it |
2589 | -- means that the user specified a check whose formal is the | |
2590 | -- predicated subtype itself, rather than some covering type. This | |
2591 | -- is likely to be a common error, and thus deserves a warning. | |
22631b41 | 2592 | |
2593 | elsif S = Predicate_Function (Typ) then | |
96a2d100 | 2594 | Error_Msg_N |
2595 | ("predicate check includes a function call that " | |
cb97ae5c | 2596 | & "requires a predicate check??", Parent (N)); |
96a2d100 | 2597 | Error_Msg_N |
cb97ae5c | 2598 | ("\this will result in infinite recursion??", Parent (N)); |
96a2d100 | 2599 | Insert_Action (N, |
61016a7a | 2600 | Make_Raise_Storage_Error (Sloc (N), |
2601 | Reason => SE_Infinite_Recursion)); | |
22631b41 | 2602 | |
64cc9e5d | 2603 | -- Here for normal case of predicate active |
e6281d47 | 2604 | |
61016a7a | 2605 | else |
b04165c4 | 2606 | -- If the type has a static predicate and the expression is known |
2607 | -- at compile time, see if the expression satisfies the predicate. | |
3a75f20b | 2608 | |
2609 | Check_Expression_Against_Static_Predicate (N, Typ); | |
e6281d47 | 2610 | |
301d5ec3 | 2611 | Insert_Action (N, |
2612 | Make_Predicate_Check (Typ, Duplicate_Subexpr (N))); | |
2613 | end if; | |
7aafae1c | 2614 | end if; |
2615 | end Apply_Predicate_Check; | |
2616 | ||
ee6ba406 | 2617 | ----------------------- |
2618 | -- Apply_Range_Check -- | |
2619 | ----------------------- | |
2620 | ||
2621 | procedure Apply_Range_Check | |
2622 | (Ck_Node : Node_Id; | |
2623 | Target_Typ : Entity_Id; | |
2624 | Source_Typ : Entity_Id := Empty) | |
2625 | is | |
2626 | begin | |
2627 | Apply_Selected_Range_Checks | |
2628 | (Ck_Node, Target_Typ, Source_Typ, Do_Static => False); | |
2629 | end Apply_Range_Check; | |
2630 | ||
2631 | ------------------------------ | |
2632 | -- Apply_Scalar_Range_Check -- | |
2633 | ------------------------------ | |
2634 | ||
feff2f05 | 2635 | -- Note that Apply_Scalar_Range_Check never turns the Do_Range_Check flag |
2636 | -- off if it is already set on. | |
ee6ba406 | 2637 | |
2638 | procedure Apply_Scalar_Range_Check | |
2639 | (Expr : Node_Id; | |
2640 | Target_Typ : Entity_Id; | |
2641 | Source_Typ : Entity_Id := Empty; | |
2642 | Fixed_Int : Boolean := False) | |
2643 | is | |
2644 | Parnt : constant Node_Id := Parent (Expr); | |
2645 | S_Typ : Entity_Id; | |
2646 | Arr : Node_Id := Empty; -- initialize to prevent warning | |
2647 | Arr_Typ : Entity_Id := Empty; -- initialize to prevent warning | |
2648 | OK : Boolean; | |
2649 | ||
2650 | Is_Subscr_Ref : Boolean; | |
2651 | -- Set true if Expr is a subscript | |
2652 | ||
2653 | Is_Unconstrained_Subscr_Ref : Boolean; | |
2654 | -- Set true if Expr is a subscript of an unconstrained array. In this | |
2655 | -- case we do not attempt to do an analysis of the value against the | |
2656 | -- range of the subscript, since we don't know the actual subtype. | |
2657 | ||
2658 | Int_Real : Boolean; | |
feff2f05 | 2659 | -- Set to True if Expr should be regarded as a real value even though |
2660 | -- the type of Expr might be discrete. | |
ee6ba406 | 2661 | |
2662 | procedure Bad_Value; | |
2663 | -- Procedure called if value is determined to be out of range | |
2664 | ||
9dfe12ae | 2665 | --------------- |
2666 | -- Bad_Value -- | |
2667 | --------------- | |
2668 | ||
ee6ba406 | 2669 | procedure Bad_Value is |
2670 | begin | |
2671 | Apply_Compile_Time_Constraint_Error | |
cb97ae5c | 2672 | (Expr, "value not in range of}??", CE_Range_Check_Failed, |
ee6ba406 | 2673 | Ent => Target_Typ, |
2674 | Typ => Target_Typ); | |
2675 | end Bad_Value; | |
2676 | ||
9dfe12ae | 2677 | -- Start of processing for Apply_Scalar_Range_Check |
2678 | ||
ee6ba406 | 2679 | begin |
2af58f67 | 2680 | -- Return if check obviously not needed |
ee6ba406 | 2681 | |
2af58f67 | 2682 | if |
2683 | -- Not needed inside generic | |
ee6ba406 | 2684 | |
2af58f67 | 2685 | Inside_A_Generic |
2686 | ||
2687 | -- Not needed if previous error | |
2688 | ||
2689 | or else Target_Typ = Any_Type | |
2690 | or else Nkind (Expr) = N_Error | |
2691 | ||
2692 | -- Not needed for non-scalar type | |
2693 | ||
2694 | or else not Is_Scalar_Type (Target_Typ) | |
2695 | ||
2696 | -- Not needed if we know node raises CE already | |
2697 | ||
2698 | or else Raises_Constraint_Error (Expr) | |
ee6ba406 | 2699 | then |
2700 | return; | |
2701 | end if; | |
2702 | ||
2703 | -- Now, see if checks are suppressed | |
2704 | ||
2705 | Is_Subscr_Ref := | |
2706 | Is_List_Member (Expr) and then Nkind (Parnt) = N_Indexed_Component; | |
2707 | ||
2708 | if Is_Subscr_Ref then | |
2709 | Arr := Prefix (Parnt); | |
2710 | Arr_Typ := Get_Actual_Subtype_If_Available (Arr); | |
cce84b09 | 2711 | |
a3a76ccc | 2712 | if Is_Access_Type (Arr_Typ) then |
245e87df | 2713 | Arr_Typ := Designated_Type (Arr_Typ); |
a3a76ccc | 2714 | end if; |
ee6ba406 | 2715 | end if; |
2716 | ||
2717 | if not Do_Range_Check (Expr) then | |
2718 | ||
2719 | -- Subscript reference. Check for Index_Checks suppressed | |
2720 | ||
2721 | if Is_Subscr_Ref then | |
2722 | ||
2723 | -- Check array type and its base type | |
2724 | ||
2725 | if Index_Checks_Suppressed (Arr_Typ) | |
9dfe12ae | 2726 | or else Index_Checks_Suppressed (Base_Type (Arr_Typ)) |
ee6ba406 | 2727 | then |
2728 | return; | |
2729 | ||
2730 | -- Check array itself if it is an entity name | |
2731 | ||
2732 | elsif Is_Entity_Name (Arr) | |
9dfe12ae | 2733 | and then Index_Checks_Suppressed (Entity (Arr)) |
ee6ba406 | 2734 | then |
2735 | return; | |
2736 | ||
2737 | -- Check expression itself if it is an entity name | |
2738 | ||
2739 | elsif Is_Entity_Name (Expr) | |
9dfe12ae | 2740 | and then Index_Checks_Suppressed (Entity (Expr)) |
ee6ba406 | 2741 | then |
2742 | return; | |
2743 | end if; | |
2744 | ||
2745 | -- All other cases, check for Range_Checks suppressed | |
2746 | ||
2747 | else | |
2748 | -- Check target type and its base type | |
2749 | ||
2750 | if Range_Checks_Suppressed (Target_Typ) | |
9dfe12ae | 2751 | or else Range_Checks_Suppressed (Base_Type (Target_Typ)) |
ee6ba406 | 2752 | then |
2753 | return; | |
2754 | ||
2755 | -- Check expression itself if it is an entity name | |
2756 | ||
2757 | elsif Is_Entity_Name (Expr) | |
9dfe12ae | 2758 | and then Range_Checks_Suppressed (Entity (Expr)) |
ee6ba406 | 2759 | then |
2760 | return; | |
2761 | ||
feff2f05 | 2762 | -- If Expr is part of an assignment statement, then check left |
2763 | -- side of assignment if it is an entity name. | |
ee6ba406 | 2764 | |
2765 | elsif Nkind (Parnt) = N_Assignment_Statement | |
2766 | and then Is_Entity_Name (Name (Parnt)) | |
9dfe12ae | 2767 | and then Range_Checks_Suppressed (Entity (Name (Parnt))) |
ee6ba406 | 2768 | then |
2769 | return; | |
2770 | end if; | |
2771 | end if; | |
2772 | end if; | |
2773 | ||
9dfe12ae | 2774 | -- Do not set range checks if they are killed |
2775 | ||
2776 | if Nkind (Expr) = N_Unchecked_Type_Conversion | |
2777 | and then Kill_Range_Check (Expr) | |
2778 | then | |
2779 | return; | |
2780 | end if; | |
2781 | ||
2782 | -- Do not set range checks for any values from System.Scalar_Values | |
2783 | -- since the whole idea of such values is to avoid checking them! | |
2784 | ||
2785 | if Is_Entity_Name (Expr) | |
2786 | and then Is_RTU (Scope (Entity (Expr)), System_Scalar_Values) | |
2787 | then | |
2788 | return; | |
2789 | end if; | |
2790 | ||
ee6ba406 | 2791 | -- Now see if we need a check |
2792 | ||
2793 | if No (Source_Typ) then | |
2794 | S_Typ := Etype (Expr); | |
2795 | else | |
2796 | S_Typ := Source_Typ; | |
2797 | end if; | |
2798 | ||
2799 | if not Is_Scalar_Type (S_Typ) or else S_Typ = Any_Type then | |
2800 | return; | |
2801 | end if; | |
2802 | ||
2803 | Is_Unconstrained_Subscr_Ref := | |
2804 | Is_Subscr_Ref and then not Is_Constrained (Arr_Typ); | |
2805 | ||
b40670e1 | 2806 | -- Special checks for floating-point type |
ee6ba406 | 2807 | |
b40670e1 | 2808 | if Is_Floating_Point_Type (S_Typ) then |
2809 | ||
2810 | -- Always do a range check if the source type includes infinities and | |
2811 | -- the target type does not include infinities. We do not do this if | |
2812 | -- range checks are killed. | |
2813 | ||
2814 | if Has_Infinities (S_Typ) | |
2815 | and then not Has_Infinities (Target_Typ) | |
2816 | then | |
2817 | Enable_Range_Check (Expr); | |
2818 | ||
2819 | -- Always do a range check for operators if option set | |
2820 | ||
2821 | elsif Check_Float_Overflow and then Nkind (Expr) in N_Op then | |
2822 | Enable_Range_Check (Expr); | |
2823 | end if; | |
ee6ba406 | 2824 | end if; |
2825 | ||
feff2f05 | 2826 | -- Return if we know expression is definitely in the range of the target |
2827 | -- type as determined by Determine_Range. Right now we only do this for | |
2828 | -- discrete types, and not fixed-point or floating-point types. | |
ee6ba406 | 2829 | |
f2a06be9 | 2830 | -- The additional less-precise tests below catch these cases |
ee6ba406 | 2831 | |
feff2f05 | 2832 | -- Note: skip this if we are given a source_typ, since the point of |
2833 | -- supplying a Source_Typ is to stop us looking at the expression. | |
2834 | -- We could sharpen this test to be out parameters only ??? | |
ee6ba406 | 2835 | |
2836 | if Is_Discrete_Type (Target_Typ) | |
2837 | and then Is_Discrete_Type (Etype (Expr)) | |
2838 | and then not Is_Unconstrained_Subscr_Ref | |
2839 | and then No (Source_Typ) | |
2840 | then | |
2841 | declare | |
2842 | Tlo : constant Node_Id := Type_Low_Bound (Target_Typ); | |
2843 | Thi : constant Node_Id := Type_High_Bound (Target_Typ); | |
2844 | Lo : Uint; | |
2845 | Hi : Uint; | |
2846 | ||
2847 | begin | |
2848 | if Compile_Time_Known_Value (Tlo) | |
2849 | and then Compile_Time_Known_Value (Thi) | |
2850 | then | |
9dfe12ae | 2851 | declare |
2852 | Lov : constant Uint := Expr_Value (Tlo); | |
2853 | Hiv : constant Uint := Expr_Value (Thi); | |
ee6ba406 | 2854 | |
9dfe12ae | 2855 | begin |
2856 | -- If range is null, we for sure have a constraint error | |
2857 | -- (we don't even need to look at the value involved, | |
2858 | -- since all possible values will raise CE). | |
2859 | ||
2860 | if Lov > Hiv then | |
2861 | Bad_Value; | |
2862 | return; | |
2863 | end if; | |
2864 | ||
2865 | -- Otherwise determine range of value | |
2866 | ||
9c486805 | 2867 | Determine_Range (Expr, OK, Lo, Hi, Assume_Valid => True); |
9dfe12ae | 2868 | |
2869 | if OK then | |
2870 | ||
2871 | -- If definitely in range, all OK | |
ee6ba406 | 2872 | |
ee6ba406 | 2873 | if Lo >= Lov and then Hi <= Hiv then |
2874 | return; | |
2875 | ||
9dfe12ae | 2876 | -- If definitely not in range, warn |
2877 | ||
ee6ba406 | 2878 | elsif Lov > Hi or else Hiv < Lo then |
2879 | Bad_Value; | |
2880 | return; | |
9dfe12ae | 2881 | |
2882 | -- Otherwise we don't know | |
2883 | ||
2884 | else | |
2885 | null; | |
ee6ba406 | 2886 | end if; |
9dfe12ae | 2887 | end if; |
2888 | end; | |
ee6ba406 | 2889 | end if; |
2890 | end; | |
2891 | end if; | |
2892 | ||
2893 | Int_Real := | |
2894 | Is_Floating_Point_Type (S_Typ) | |
2895 | or else (Is_Fixed_Point_Type (S_Typ) and then not Fixed_Int); | |
2896 | ||
2897 | -- Check if we can determine at compile time whether Expr is in the | |
9dfe12ae | 2898 | -- range of the target type. Note that if S_Typ is within the bounds |
2899 | -- of Target_Typ then this must be the case. This check is meaningful | |
2900 | -- only if this is not a conversion between integer and real types. | |
ee6ba406 | 2901 | |
2902 | if not Is_Unconstrained_Subscr_Ref | |
b40670e1 | 2903 | and then Is_Discrete_Type (S_Typ) = Is_Discrete_Type (Target_Typ) |
ee6ba406 | 2904 | and then |
7a1dabb3 | 2905 | (In_Subrange_Of (S_Typ, Target_Typ, Fixed_Int) |
ee6ba406 | 2906 | or else |
9c486805 | 2907 | Is_In_Range (Expr, Target_Typ, |
2908 | Assume_Valid => True, | |
b40670e1 | 2909 | Fixed_Int => Fixed_Int, |
2910 | Int_Real => Int_Real)) | |
ee6ba406 | 2911 | then |
2912 | return; | |
2913 | ||
9c486805 | 2914 | elsif Is_Out_Of_Range (Expr, Target_Typ, |
2915 | Assume_Valid => True, | |
2916 | Fixed_Int => Fixed_Int, | |
2917 | Int_Real => Int_Real) | |
2918 | then | |
ee6ba406 | 2919 | Bad_Value; |
2920 | return; | |
2921 | ||
b40670e1 | 2922 | -- Floating-point case |
feff2f05 | 2923 | -- In the floating-point case, we only do range checks if the type is |
2924 | -- constrained. We definitely do NOT want range checks for unconstrained | |
2925 | -- types, since we want to have infinities | |
ee6ba406 | 2926 | |
9dfe12ae | 2927 | elsif Is_Floating_Point_Type (S_Typ) then |
b40670e1 | 2928 | |
2929 | -- Normally, we only do range checks if the type is constrained. We do | |
2930 | -- NOT want range checks for unconstrained types, since we want to have | |
2931 | -- infinities. Override this decision in Check_Float_Overflow mode. | |
2932 | ||
2933 | if Is_Constrained (S_Typ) or else Check_Float_Overflow then | |
9dfe12ae | 2934 | Enable_Range_Check (Expr); |
2935 | end if; | |
ee6ba406 | 2936 | |
9dfe12ae | 2937 | -- For all other cases we enable a range check unconditionally |
ee6ba406 | 2938 | |
2939 | else | |
2940 | Enable_Range_Check (Expr); | |
2941 | return; | |
2942 | end if; | |
ee6ba406 | 2943 | end Apply_Scalar_Range_Check; |
2944 | ||
2945 | ---------------------------------- | |
2946 | -- Apply_Selected_Length_Checks -- | |
2947 | ---------------------------------- | |
2948 | ||
2949 | procedure Apply_Selected_Length_Checks | |
2950 | (Ck_Node : Node_Id; | |
2951 | Target_Typ : Entity_Id; | |
2952 | Source_Typ : Entity_Id; | |
2953 | Do_Static : Boolean) | |
2954 | is | |
2955 | Cond : Node_Id; | |
2956 | R_Result : Check_Result; | |
2957 | R_Cno : Node_Id; | |
2958 | ||
2959 | Loc : constant Source_Ptr := Sloc (Ck_Node); | |
2960 | Checks_On : constant Boolean := | |
b6341c67 | 2961 | (not Index_Checks_Suppressed (Target_Typ)) |
4098232e | 2962 | or else (not Length_Checks_Suppressed (Target_Typ)); |
ee6ba406 | 2963 | |
2964 | begin | |
4098232e | 2965 | -- Note: this means that we lose some useful warnings if the expander |
2966 | -- is not active, and we also lose these warnings in SPARK mode ??? | |
2967 | ||
a33565dd | 2968 | if not Expander_Active then |
ee6ba406 | 2969 | return; |
2970 | end if; | |
2971 | ||
2972 | R_Result := | |
2973 | Selected_Length_Checks (Ck_Node, Target_Typ, Source_Typ, Empty); | |
2974 | ||
2975 | for J in 1 .. 2 loop | |
ee6ba406 | 2976 | R_Cno := R_Result (J); |
2977 | exit when No (R_Cno); | |
2978 | ||
2979 | -- A length check may mention an Itype which is attached to a | |
2980 | -- subsequent node. At the top level in a package this can cause | |
2981 | -- an order-of-elaboration problem, so we make sure that the itype | |
2982 | -- is referenced now. | |
2983 | ||
2984 | if Ekind (Current_Scope) = E_Package | |
2985 | and then Is_Compilation_Unit (Current_Scope) | |
2986 | then | |
2987 | Ensure_Defined (Target_Typ, Ck_Node); | |
2988 | ||
2989 | if Present (Source_Typ) then | |
2990 | Ensure_Defined (Source_Typ, Ck_Node); | |
2991 | ||
2992 | elsif Is_Itype (Etype (Ck_Node)) then | |
2993 | Ensure_Defined (Etype (Ck_Node), Ck_Node); | |
2994 | end if; | |
2995 | end if; | |
2996 | ||
feff2f05 | 2997 | -- If the item is a conditional raise of constraint error, then have |
2998 | -- a look at what check is being performed and ??? | |
ee6ba406 | 2999 | |
3000 | if Nkind (R_Cno) = N_Raise_Constraint_Error | |
3001 | and then Present (Condition (R_Cno)) | |
3002 | then | |
3003 | Cond := Condition (R_Cno); | |
3004 | ||
0577b0b1 | 3005 | -- Case where node does not now have a dynamic check |
ee6ba406 | 3006 | |
0577b0b1 | 3007 | if not Has_Dynamic_Length_Check (Ck_Node) then |
3008 | ||
3009 | -- If checks are on, just insert the check | |
3010 | ||
3011 | if Checks_On then | |
3012 | Insert_Action (Ck_Node, R_Cno); | |
3013 | ||
3014 | if not Do_Static then | |
3015 | Set_Has_Dynamic_Length_Check (Ck_Node); | |
3016 | end if; | |
3017 | ||
3018 | -- If checks are off, then analyze the length check after | |
3019 | -- temporarily attaching it to the tree in case the relevant | |
6fb3c314 | 3020 | -- condition can be evaluated at compile time. We still want a |
0577b0b1 | 3021 | -- compile time warning in this case. |
3022 | ||
3023 | else | |
3024 | Set_Parent (R_Cno, Ck_Node); | |
3025 | Analyze (R_Cno); | |
ee6ba406 | 3026 | end if; |
ee6ba406 | 3027 | end if; |
3028 | ||
3029 | -- Output a warning if the condition is known to be True | |
3030 | ||
3031 | if Is_Entity_Name (Cond) | |
3032 | and then Entity (Cond) = Standard_True | |
3033 | then | |
3034 | Apply_Compile_Time_Constraint_Error | |
cb97ae5c | 3035 | (Ck_Node, "wrong length for array of}??", |
f15731c4 | 3036 | CE_Length_Check_Failed, |
ee6ba406 | 3037 | Ent => Target_Typ, |
3038 | Typ => Target_Typ); | |
3039 | ||
3040 | -- If we were only doing a static check, or if checks are not | |
3041 | -- on, then we want to delete the check, since it is not needed. | |
3042 | -- We do this by replacing the if statement by a null statement | |
3043 | ||
3044 | elsif Do_Static or else not Checks_On then | |
00c403ee | 3045 | Remove_Warning_Messages (R_Cno); |
ee6ba406 | 3046 | Rewrite (R_Cno, Make_Null_Statement (Loc)); |
3047 | end if; | |
3048 | ||
3049 | else | |
3050 | Install_Static_Check (R_Cno, Loc); | |
3051 | end if; | |
ee6ba406 | 3052 | end loop; |
ee6ba406 | 3053 | end Apply_Selected_Length_Checks; |
3054 | ||
3055 | --------------------------------- | |
3056 | -- Apply_Selected_Range_Checks -- | |
3057 | --------------------------------- | |
3058 | ||
3059 | procedure Apply_Selected_Range_Checks | |
3060 | (Ck_Node : Node_Id; | |
3061 | Target_Typ : Entity_Id; | |
3062 | Source_Typ : Entity_Id; | |
3063 | Do_Static : Boolean) | |
3064 | is | |
3065 | Cond : Node_Id; | |
3066 | R_Result : Check_Result; | |
3067 | R_Cno : Node_Id; | |
3068 | ||
3069 | Loc : constant Source_Ptr := Sloc (Ck_Node); | |
3070 | Checks_On : constant Boolean := | |
b6341c67 | 3071 | (not Index_Checks_Suppressed (Target_Typ)) |
3072 | or else (not Range_Checks_Suppressed (Target_Typ)); | |
ee6ba406 | 3073 | |
3074 | begin | |
a33565dd | 3075 | if not Expander_Active or else not Checks_On then |
ee6ba406 | 3076 | return; |
3077 | end if; | |
3078 | ||
3079 | R_Result := | |
3080 | Selected_Range_Checks (Ck_Node, Target_Typ, Source_Typ, Empty); | |
3081 | ||
3082 | for J in 1 .. 2 loop | |
3083 | ||
3084 | R_Cno := R_Result (J); | |
3085 | exit when No (R_Cno); | |
3086 | ||
feff2f05 | 3087 | -- If the item is a conditional raise of constraint error, then have |
3088 | -- a look at what check is being performed and ??? | |
ee6ba406 | 3089 | |
3090 | if Nkind (R_Cno) = N_Raise_Constraint_Error | |
3091 | and then Present (Condition (R_Cno)) | |
3092 | then | |
3093 | Cond := Condition (R_Cno); | |
3094 | ||
3095 | if not Has_Dynamic_Range_Check (Ck_Node) then | |
3096 | Insert_Action (Ck_Node, R_Cno); | |
3097 | ||
3098 | if not Do_Static then | |
3099 | Set_Has_Dynamic_Range_Check (Ck_Node); | |
3100 | end if; | |
3101 | end if; | |
3102 | ||
3103 | -- Output a warning if the condition is known to be True | |
3104 | ||
3105 | if Is_Entity_Name (Cond) | |
3106 | and then Entity (Cond) = Standard_True | |
3107 | then | |
feff2f05 | 3108 | -- Since an N_Range is technically not an expression, we have |
3109 | -- to set one of the bounds to C_E and then just flag the | |
3110 | -- N_Range. The warning message will point to the lower bound | |
3111 | -- and complain about a range, which seems OK. | |
ee6ba406 | 3112 | |
3113 | if Nkind (Ck_Node) = N_Range then | |
3114 | Apply_Compile_Time_Constraint_Error | |
cb97ae5c | 3115 | (Low_Bound (Ck_Node), "static range out of bounds of}??", |
f15731c4 | 3116 | CE_Range_Check_Failed, |
ee6ba406 | 3117 | Ent => Target_Typ, |
3118 | Typ => Target_Typ); | |
3119 | ||
3120 | Set_Raises_Constraint_Error (Ck_Node); | |
3121 | ||
3122 | else | |
3123 | Apply_Compile_Time_Constraint_Error | |
3124 | (Ck_Node, "static value out of range of}?", | |
f15731c4 | 3125 | CE_Range_Check_Failed, |
ee6ba406 | 3126 | Ent => Target_Typ, |
3127 | Typ => Target_Typ); | |
3128 | end if; | |
3129 | ||
3130 | -- If we were only doing a static check, or if checks are not | |
3131 | -- on, then we want to delete the check, since it is not needed. | |
3132 | -- We do this by replacing the if statement by a null statement | |
3133 | ||
3134 | elsif Do_Static or else not Checks_On then | |
00c403ee | 3135 | Remove_Warning_Messages (R_Cno); |
ee6ba406 | 3136 | Rewrite (R_Cno, Make_Null_Statement (Loc)); |
3137 | end if; | |
3138 | ||
3139 | else | |
3140 | Install_Static_Check (R_Cno, Loc); | |
3141 | end if; | |
ee6ba406 | 3142 | end loop; |
ee6ba406 | 3143 | end Apply_Selected_Range_Checks; |
3144 | ||
3145 | ------------------------------- | |
3146 | -- Apply_Static_Length_Check -- | |
3147 | ------------------------------- | |
3148 | ||
3149 | procedure Apply_Static_Length_Check | |
3150 | (Expr : Node_Id; | |
3151 | Target_Typ : Entity_Id; | |
3152 | Source_Typ : Entity_Id := Empty) | |
3153 | is | |
3154 | begin | |
3155 | Apply_Selected_Length_Checks | |
3156 | (Expr, Target_Typ, Source_Typ, Do_Static => True); | |
3157 | end Apply_Static_Length_Check; | |
3158 | ||
3159 | ------------------------------------- | |
3160 | -- Apply_Subscript_Validity_Checks -- | |
3161 | ------------------------------------- | |
3162 | ||
3163 | procedure Apply_Subscript_Validity_Checks (Expr : Node_Id) is | |
3164 | Sub : Node_Id; | |
3165 | ||
3166 | begin | |
3167 | pragma Assert (Nkind (Expr) = N_Indexed_Component); | |
3168 | ||
3169 | -- Loop through subscripts | |
3170 | ||
3171 | Sub := First (Expressions (Expr)); | |
3172 | while Present (Sub) loop | |
3173 | ||
feff2f05 | 3174 | -- Check one subscript. Note that we do not worry about enumeration |
3175 | -- type with holes, since we will convert the value to a Pos value | |
3176 | -- for the subscript, and that convert will do the necessary validity | |
3177 | -- check. | |
ee6ba406 | 3178 | |
3179 | Ensure_Valid (Sub, Holes_OK => True); | |
3180 | ||
3181 | -- Move to next subscript | |
3182 | ||
3183 | Sub := Next (Sub); | |
3184 | end loop; | |
3185 | end Apply_Subscript_Validity_Checks; | |
3186 | ||
3187 | ---------------------------------- | |
3188 | -- Apply_Type_Conversion_Checks -- | |
3189 | ---------------------------------- | |
3190 | ||
3191 | procedure Apply_Type_Conversion_Checks (N : Node_Id) is | |
3192 | Target_Type : constant Entity_Id := Etype (N); | |
3193 | Target_Base : constant Entity_Id := Base_Type (Target_Type); | |
9dfe12ae | 3194 | Expr : constant Node_Id := Expression (N); |
f4532fe1 | 3195 | |
3196 | Expr_Type : constant Entity_Id := Underlying_Type (Etype (Expr)); | |
141d591a | 3197 | -- Note: if Etype (Expr) is a private type without discriminants, its |
3198 | -- full view might have discriminants with defaults, so we need the | |
3199 | -- full view here to retrieve the constraints. | |
ee6ba406 | 3200 | |
3201 | begin | |
3202 | if Inside_A_Generic then | |
3203 | return; | |
3204 | ||
f15731c4 | 3205 | -- Skip these checks if serious errors detected, there are some nasty |
ee6ba406 | 3206 | -- situations of incomplete trees that blow things up. |
3207 | ||
f15731c4 | 3208 | elsif Serious_Errors_Detected > 0 then |
ee6ba406 | 3209 | return; |
3210 | ||
feff2f05 | 3211 | -- Scalar type conversions of the form Target_Type (Expr) require a |
3212 | -- range check if we cannot be sure that Expr is in the base type of | |
3213 | -- Target_Typ and also that Expr is in the range of Target_Typ. These | |
3214 | -- are not quite the same condition from an implementation point of | |
3215 | -- view, but clearly the second includes the first. | |
ee6ba406 | 3216 | |
3217 | elsif Is_Scalar_Type (Target_Type) then | |
3218 | declare | |
3219 | Conv_OK : constant Boolean := Conversion_OK (N); | |
feff2f05 | 3220 | -- If the Conversion_OK flag on the type conversion is set and no |
3221 | -- floating point type is involved in the type conversion then | |
3222 | -- fixed point values must be read as integral values. | |
ee6ba406 | 3223 | |
5329ca64 | 3224 | Float_To_Int : constant Boolean := |
b6341c67 | 3225 | Is_Floating_Point_Type (Expr_Type) |
3226 | and then Is_Integer_Type (Target_Type); | |
5329ca64 | 3227 | |
ee6ba406 | 3228 | begin |
ee6ba406 | 3229 | if not Overflow_Checks_Suppressed (Target_Base) |
0df9d43f | 3230 | and then not Overflow_Checks_Suppressed (Target_Type) |
e254d721 | 3231 | and then not |
7a1dabb3 | 3232 | In_Subrange_Of (Expr_Type, Target_Base, Fixed_Int => Conv_OK) |
5329ca64 | 3233 | and then not Float_To_Int |
ee6ba406 | 3234 | then |
00c403ee | 3235 | Activate_Overflow_Check (N); |
ee6ba406 | 3236 | end if; |
3237 | ||
3238 | if not Range_Checks_Suppressed (Target_Type) | |
3239 | and then not Range_Checks_Suppressed (Expr_Type) | |
3240 | then | |
5329ca64 | 3241 | if Float_To_Int then |
3242 | Apply_Float_Conversion_Check (Expr, Target_Type); | |
3243 | else | |
3244 | Apply_Scalar_Range_Check | |
3245 | (Expr, Target_Type, Fixed_Int => Conv_OK); | |
798afddc | 3246 | |
3247 | -- If the target type has predicates, we need to indicate | |
3248 | -- the need for a check, even if Determine_Range finds | |
3249 | -- that the value is within bounds. This may be the case | |
3250 | -- e.g for a division with a constant denominator. | |
3251 | ||
3252 | if Has_Predicates (Target_Type) then | |
3253 | Enable_Range_Check (Expr); | |
3254 | end if; | |
5329ca64 | 3255 | end if; |
ee6ba406 | 3256 | end if; |
3257 | end; | |
3258 | ||
3259 | elsif Comes_From_Source (N) | |
f40f9731 | 3260 | and then not Discriminant_Checks_Suppressed (Target_Type) |
ee6ba406 | 3261 | and then Is_Record_Type (Target_Type) |
3262 | and then Is_Derived_Type (Target_Type) | |
3263 | and then not Is_Tagged_Type (Target_Type) | |
3264 | and then not Is_Constrained (Target_Type) | |
9dfe12ae | 3265 | and then Present (Stored_Constraint (Target_Type)) |
ee6ba406 | 3266 | then |
141d591a | 3267 | -- An unconstrained derived type may have inherited discriminant. |
9dfe12ae | 3268 | -- Build an actual discriminant constraint list using the stored |
ee6ba406 | 3269 | -- constraint, to verify that the expression of the parent type |
3270 | -- satisfies the constraints imposed by the (unconstrained!) | |
3271 | -- derived type. This applies to value conversions, not to view | |
3272 | -- conversions of tagged types. | |
3273 | ||
3274 | declare | |
9dfe12ae | 3275 | Loc : constant Source_Ptr := Sloc (N); |
3276 | Cond : Node_Id; | |
3277 | Constraint : Elmt_Id; | |
3278 | Discr_Value : Node_Id; | |
3279 | Discr : Entity_Id; | |
3280 | ||
3281 | New_Constraints : constant Elist_Id := New_Elmt_List; | |
3282 | Old_Constraints : constant Elist_Id := | |
b6341c67 | 3283 | Discriminant_Constraint (Expr_Type); |
ee6ba406 | 3284 | |
3285 | begin | |
9dfe12ae | 3286 | Constraint := First_Elmt (Stored_Constraint (Target_Type)); |
ee6ba406 | 3287 | while Present (Constraint) loop |
3288 | Discr_Value := Node (Constraint); | |
3289 | ||
3290 | if Is_Entity_Name (Discr_Value) | |
3291 | and then Ekind (Entity (Discr_Value)) = E_Discriminant | |
3292 | then | |
3293 | Discr := Corresponding_Discriminant (Entity (Discr_Value)); | |
3294 | ||
3295 | if Present (Discr) | |
3296 | and then Scope (Discr) = Base_Type (Expr_Type) | |
3297 | then | |
3298 | -- Parent is constrained by new discriminant. Obtain | |
feff2f05 | 3299 | -- Value of original discriminant in expression. If the |
3300 | -- new discriminant has been used to constrain more than | |
3301 | -- one of the stored discriminants, this will provide the | |
3302 | -- required consistency check. | |
ee6ba406 | 3303 | |
55868293 | 3304 | Append_Elmt |
3305 | (Make_Selected_Component (Loc, | |
3306 | Prefix => | |
9dfe12ae | 3307 | Duplicate_Subexpr_No_Checks |
3308 | (Expr, Name_Req => True), | |
ee6ba406 | 3309 | Selector_Name => |
3310 | Make_Identifier (Loc, Chars (Discr))), | |
55868293 | 3311 | New_Constraints); |
ee6ba406 | 3312 | |
3313 | else | |
3314 | -- Discriminant of more remote ancestor ??? | |
3315 | ||
3316 | return; | |
3317 | end if; | |
3318 | ||
feff2f05 | 3319 | -- Derived type definition has an explicit value for this |
3320 | -- stored discriminant. | |
ee6ba406 | 3321 | |
3322 | else | |
3323 | Append_Elmt | |
9dfe12ae | 3324 | (Duplicate_Subexpr_No_Checks (Discr_Value), |
3325 | New_Constraints); | |
ee6ba406 | 3326 | end if; |
3327 | ||
3328 | Next_Elmt (Constraint); | |
3329 | end loop; | |
3330 | ||
3331 | -- Use the unconstrained expression type to retrieve the | |
3332 | -- discriminants of the parent, and apply momentarily the | |
3333 | -- discriminant constraint synthesized above. | |
3334 | ||
3335 | Set_Discriminant_Constraint (Expr_Type, New_Constraints); | |
3336 | Cond := Build_Discriminant_Checks (Expr, Expr_Type); | |
3337 | Set_Discriminant_Constraint (Expr_Type, Old_Constraints); | |
3338 | ||
3339 | Insert_Action (N, | |
f15731c4 | 3340 | Make_Raise_Constraint_Error (Loc, |
3341 | Condition => Cond, | |
3342 | Reason => CE_Discriminant_Check_Failed)); | |
ee6ba406 | 3343 | end; |
3344 | ||
175a6969 | 3345 | -- For arrays, checks are set now, but conversions are applied during |
3346 | -- expansion, to take into accounts changes of representation. The | |
3347 | -- checks become range checks on the base type or length checks on the | |
3348 | -- subtype, depending on whether the target type is unconstrained or | |
8e802312 | 3349 | -- constrained. Note that the range check is put on the expression of a |
3350 | -- type conversion, while the length check is put on the type conversion | |
3351 | -- itself. | |
175a6969 | 3352 | |
3353 | elsif Is_Array_Type (Target_Type) then | |
3354 | if Is_Constrained (Target_Type) then | |
3355 | Set_Do_Length_Check (N); | |
3356 | else | |
3357 | Set_Do_Range_Check (Expr); | |
3358 | end if; | |
ee6ba406 | 3359 | end if; |
ee6ba406 | 3360 | end Apply_Type_Conversion_Checks; |
3361 | ||
3362 | ---------------------------------------------- | |
3363 | -- Apply_Universal_Integer_Attribute_Checks -- | |
3364 | ---------------------------------------------- | |
3365 | ||
3366 | procedure Apply_Universal_Integer_Attribute_Checks (N : Node_Id) is | |
3367 | Loc : constant Source_Ptr := Sloc (N); | |
3368 | Typ : constant Entity_Id := Etype (N); | |
3369 | ||
3370 | begin | |
3371 | if Inside_A_Generic then | |
3372 | return; | |
3373 | ||
3374 | -- Nothing to do if checks are suppressed | |
3375 | ||
3376 | elsif Range_Checks_Suppressed (Typ) | |
3377 | and then Overflow_Checks_Suppressed (Typ) | |
3378 | then | |
3379 | return; | |
3380 | ||
3381 | -- Nothing to do if the attribute does not come from source. The | |
3382 | -- internal attributes we generate of this type do not need checks, | |
3383 | -- and furthermore the attempt to check them causes some circular | |
3384 | -- elaboration orders when dealing with packed types. | |
3385 | ||
3386 | elsif not Comes_From_Source (N) then | |
3387 | return; | |
3388 | ||
9dfe12ae | 3389 | -- If the prefix is a selected component that depends on a discriminant |
3390 | -- the check may improperly expose a discriminant instead of using | |
3391 | -- the bounds of the object itself. Set the type of the attribute to | |
3392 | -- the base type of the context, so that a check will be imposed when | |
3393 | -- needed (e.g. if the node appears as an index). | |
3394 | ||
3395 | elsif Nkind (Prefix (N)) = N_Selected_Component | |
3396 | and then Ekind (Typ) = E_Signed_Integer_Subtype | |
3397 | and then Depends_On_Discriminant (Scalar_Range (Typ)) | |
3398 | then | |
3399 | Set_Etype (N, Base_Type (Typ)); | |
3400 | ||
feff2f05 | 3401 | -- Otherwise, replace the attribute node with a type conversion node |
3402 | -- whose expression is the attribute, retyped to universal integer, and | |
3403 | -- whose subtype mark is the target type. The call to analyze this | |
3404 | -- conversion will set range and overflow checks as required for proper | |
3405 | -- detection of an out of range value. | |
ee6ba406 | 3406 | |
3407 | else | |
3408 | Set_Etype (N, Universal_Integer); | |
3409 | Set_Analyzed (N, True); | |
3410 | ||
3411 | Rewrite (N, | |
3412 | Make_Type_Conversion (Loc, | |
3413 | Subtype_Mark => New_Occurrence_Of (Typ, Loc), | |
3414 | Expression => Relocate_Node (N))); | |
3415 | ||
3416 | Analyze_And_Resolve (N, Typ); | |
3417 | return; | |
3418 | end if; | |
ee6ba406 | 3419 | end Apply_Universal_Integer_Attribute_Checks; |
3420 | ||
07c191b0 | 3421 | ------------------------------------- |
3422 | -- Atomic_Synchronization_Disabled -- | |
3423 | ------------------------------------- | |
3424 | ||
3425 | -- Note: internally Disable/Enable_Atomic_Synchronization is implemented | |
3426 | -- using a bogus check called Atomic_Synchronization. This is to make it | |
3427 | -- more convenient to get exactly the same semantics as [Un]Suppress. | |
3428 | ||
3429 | function Atomic_Synchronization_Disabled (E : Entity_Id) return Boolean is | |
3430 | begin | |
b444f81d | 3431 | -- If debug flag d.e is set, always return False, i.e. all atomic sync |
3432 | -- looks enabled, since it is never disabled. | |
3433 | ||
3434 | if Debug_Flag_Dot_E then | |
3435 | return False; | |
3436 | ||
3437 | -- If debug flag d.d is set then always return True, i.e. all atomic | |
3438 | -- sync looks disabled, since it always tests True. | |
3439 | ||
3440 | elsif Debug_Flag_Dot_D then | |
3441 | return True; | |
3442 | ||
3443 | -- If entity present, then check result for that entity | |
3444 | ||
3445 | elsif Present (E) and then Checks_May_Be_Suppressed (E) then | |
07c191b0 | 3446 | return Is_Check_Suppressed (E, Atomic_Synchronization); |
b444f81d | 3447 | |
3448 | -- Otherwise result depends on current scope setting | |
3449 | ||
07c191b0 | 3450 | else |
fafc6b97 | 3451 | return Scope_Suppress.Suppress (Atomic_Synchronization); |
07c191b0 | 3452 | end if; |
3453 | end Atomic_Synchronization_Disabled; | |
3454 | ||
ee6ba406 | 3455 | ------------------------------- |
3456 | -- Build_Discriminant_Checks -- | |
3457 | ------------------------------- | |
3458 | ||
3459 | function Build_Discriminant_Checks | |
3460 | (N : Node_Id; | |
314a23b6 | 3461 | T_Typ : Entity_Id) return Node_Id |
ee6ba406 | 3462 | is |
3463 | Loc : constant Source_Ptr := Sloc (N); | |
3464 | Cond : Node_Id; | |
3465 | Disc : Elmt_Id; | |
3466 | Disc_Ent : Entity_Id; | |
9dfe12ae | 3467 | Dref : Node_Id; |
ee6ba406 | 3468 | Dval : Node_Id; |
3469 | ||
84d0d4a5 | 3470 | function Aggregate_Discriminant_Val (Disc : Entity_Id) return Node_Id; |
3471 | ||
3472 | ---------------------------------- | |
3473 | -- Aggregate_Discriminant_Value -- | |
3474 | ---------------------------------- | |
3475 | ||
3476 | function Aggregate_Discriminant_Val (Disc : Entity_Id) return Node_Id is | |
3477 | Assoc : Node_Id; | |
3478 | ||
3479 | begin | |
feff2f05 | 3480 | -- The aggregate has been normalized with named associations. We use |
3481 | -- the Chars field to locate the discriminant to take into account | |
3482 | -- discriminants in derived types, which carry the same name as those | |
3483 | -- in the parent. | |
84d0d4a5 | 3484 | |
3485 | Assoc := First (Component_Associations (N)); | |
3486 | while Present (Assoc) loop | |
3487 | if Chars (First (Choices (Assoc))) = Chars (Disc) then | |
3488 | return Expression (Assoc); | |
3489 | else | |
3490 | Next (Assoc); | |
3491 | end if; | |
3492 | end loop; | |
3493 | ||
3494 | -- Discriminant must have been found in the loop above | |
3495 | ||
3496 | raise Program_Error; | |
3497 | end Aggregate_Discriminant_Val; | |
3498 | ||
3499 | -- Start of processing for Build_Discriminant_Checks | |
3500 | ||
ee6ba406 | 3501 | begin |
84d0d4a5 | 3502 | -- Loop through discriminants evolving the condition |
3503 | ||
ee6ba406 | 3504 | Cond := Empty; |
3505 | Disc := First_Elmt (Discriminant_Constraint (T_Typ)); | |
3506 | ||
9dfe12ae | 3507 | -- For a fully private type, use the discriminants of the parent type |
ee6ba406 | 3508 | |
3509 | if Is_Private_Type (T_Typ) | |
3510 | and then No (Full_View (T_Typ)) | |
3511 | then | |
3512 | Disc_Ent := First_Discriminant (Etype (Base_Type (T_Typ))); | |
3513 | else | |
3514 | Disc_Ent := First_Discriminant (T_Typ); | |
3515 | end if; | |
3516 | ||
3517 | while Present (Disc) loop | |
ee6ba406 | 3518 | Dval := Node (Disc); |
3519 | ||
3520 | if Nkind (Dval) = N_Identifier | |
3521 | and then Ekind (Entity (Dval)) = E_Discriminant | |
3522 | then | |
3523 | Dval := New_Occurrence_Of (Discriminal (Entity (Dval)), Loc); | |
3524 | else | |
9dfe12ae | 3525 | Dval := Duplicate_Subexpr_No_Checks (Dval); |
ee6ba406 | 3526 | end if; |
3527 | ||
00f91aef | 3528 | -- If we have an Unchecked_Union node, we can infer the discriminants |
3529 | -- of the node. | |
9dfe12ae | 3530 | |
00f91aef | 3531 | if Is_Unchecked_Union (Base_Type (T_Typ)) then |
3532 | Dref := New_Copy ( | |
3533 | Get_Discriminant_Value ( | |
3534 | First_Discriminant (T_Typ), | |
3535 | T_Typ, | |
3536 | Stored_Constraint (T_Typ))); | |
3537 | ||
84d0d4a5 | 3538 | elsif Nkind (N) = N_Aggregate then |
3539 | Dref := | |
3540 | Duplicate_Subexpr_No_Checks | |
3541 | (Aggregate_Discriminant_Val (Disc_Ent)); | |
3542 | ||
00f91aef | 3543 | else |
3544 | Dref := | |
3545 | Make_Selected_Component (Loc, | |
20cf157b | 3546 | Prefix => |
00f91aef | 3547 | Duplicate_Subexpr_No_Checks (N, Name_Req => True), |
20cf157b | 3548 | Selector_Name => Make_Identifier (Loc, Chars (Disc_Ent))); |
00f91aef | 3549 | |
3550 | Set_Is_In_Discriminant_Check (Dref); | |
3551 | end if; | |
9dfe12ae | 3552 | |
ee6ba406 | 3553 | Evolve_Or_Else (Cond, |
3554 | Make_Op_Ne (Loc, | |
20cf157b | 3555 | Left_Opnd => Dref, |
ee6ba406 | 3556 | Right_Opnd => Dval)); |
3557 | ||
3558 | Next_Elmt (Disc); | |
3559 | Next_Discriminant (Disc_Ent); | |
3560 | end loop; | |
3561 | ||
3562 | return Cond; | |
3563 | end Build_Discriminant_Checks; | |
3564 | ||
13dbf220 | 3565 | ------------------ |
3566 | -- Check_Needed -- | |
3567 | ------------------ | |
3568 | ||
3569 | function Check_Needed (Nod : Node_Id; Check : Check_Type) return Boolean is | |
3570 | N : Node_Id; | |
3571 | P : Node_Id; | |
3572 | K : Node_Kind; | |
3573 | L : Node_Id; | |
3574 | R : Node_Id; | |
3575 | ||
9b2068d4 | 3576 | function Left_Expression (Op : Node_Id) return Node_Id; |
3577 | -- Return the relevant expression from the left operand of the given | |
3578 | -- short circuit form: this is LO itself, except if LO is a qualified | |
3579 | -- expression, a type conversion, or an expression with actions, in | |
3580 | -- which case this is Left_Expression (Expression (LO)). | |
3581 | ||
3582 | --------------------- | |
3583 | -- Left_Expression -- | |
3584 | --------------------- | |
3585 | ||
3586 | function Left_Expression (Op : Node_Id) return Node_Id is | |
3587 | LE : Node_Id := Left_Opnd (Op); | |
3588 | begin | |
20cf157b | 3589 | while Nkind_In (LE, N_Qualified_Expression, |
3590 | N_Type_Conversion, | |
3591 | N_Expression_With_Actions) | |
9b2068d4 | 3592 | loop |
3593 | LE := Expression (LE); | |
3594 | end loop; | |
3595 | ||
3596 | return LE; | |
3597 | end Left_Expression; | |
3598 | ||
3599 | -- Start of processing for Check_Needed | |
3600 | ||
13dbf220 | 3601 | begin |
3602 | -- Always check if not simple entity | |
3603 | ||
3604 | if Nkind (Nod) not in N_Has_Entity | |
3605 | or else not Comes_From_Source (Nod) | |
3606 | then | |
3607 | return True; | |
3608 | end if; | |
3609 | ||
3610 | -- Look up tree for short circuit | |
3611 | ||
3612 | N := Nod; | |
3613 | loop | |
3614 | P := Parent (N); | |
3615 | K := Nkind (P); | |
3616 | ||
7b17e51b | 3617 | -- Done if out of subexpression (note that we allow generated stuff |
3618 | -- such as itype declarations in this context, to keep the loop going | |
3619 | -- since we may well have generated such stuff in complex situations. | |
3620 | -- Also done if no parent (probably an error condition, but no point | |
3621 | -- in behaving nasty if we find it!) | |
3622 | ||
3623 | if No (P) | |
3624 | or else (K not in N_Subexpr and then Comes_From_Source (P)) | |
3625 | then | |
13dbf220 | 3626 | return True; |
3627 | ||
7b17e51b | 3628 | -- Or/Or Else case, where test is part of the right operand, or is |
3629 | -- part of one of the actions associated with the right operand, and | |
3630 | -- the left operand is an equality test. | |
13dbf220 | 3631 | |
7b17e51b | 3632 | elsif K = N_Op_Or then |
13dbf220 | 3633 | exit when N = Right_Opnd (P) |
9b2068d4 | 3634 | and then Nkind (Left_Expression (P)) = N_Op_Eq; |
13dbf220 | 3635 | |
7b17e51b | 3636 | elsif K = N_Or_Else then |
3637 | exit when (N = Right_Opnd (P) | |
3638 | or else | |
3639 | (Is_List_Member (N) | |
3640 | and then List_Containing (N) = Actions (P))) | |
9b2068d4 | 3641 | and then Nkind (Left_Expression (P)) = N_Op_Eq; |
13dbf220 | 3642 | |
7b17e51b | 3643 | -- Similar test for the And/And then case, where the left operand |
3644 | -- is an inequality test. | |
3645 | ||
3646 | elsif K = N_Op_And then | |
13dbf220 | 3647 | exit when N = Right_Opnd (P) |
9b2068d4 | 3648 | and then Nkind (Left_Expression (P)) = N_Op_Ne; |
7b17e51b | 3649 | |
3650 | elsif K = N_And_Then then | |
3651 | exit when (N = Right_Opnd (P) | |
3652 | or else | |
3653 | (Is_List_Member (N) | |
20cf157b | 3654 | and then List_Containing (N) = Actions (P))) |
9b2068d4 | 3655 | and then Nkind (Left_Expression (P)) = N_Op_Ne; |
13dbf220 | 3656 | end if; |
3657 | ||
3658 | N := P; | |
3659 | end loop; | |
3660 | ||
3661 | -- If we fall through the loop, then we have a conditional with an | |
9b2068d4 | 3662 | -- appropriate test as its left operand, so look further. |
3663 | ||
3664 | L := Left_Expression (P); | |
3665 | ||
3666 | -- L is an "=" or "/=" operator: extract its operands | |
13dbf220 | 3667 | |
13dbf220 | 3668 | R := Right_Opnd (L); |
3669 | L := Left_Opnd (L); | |
3670 | ||
3671 | -- Left operand of test must match original variable | |
3672 | ||
20cf157b | 3673 | if Nkind (L) not in N_Has_Entity or else Entity (L) /= Entity (Nod) then |
13dbf220 | 3674 | return True; |
3675 | end if; | |
3676 | ||
2af58f67 | 3677 | -- Right operand of test must be key value (zero or null) |
13dbf220 | 3678 | |
3679 | case Check is | |
3680 | when Access_Check => | |
2af58f67 | 3681 | if not Known_Null (R) then |
13dbf220 | 3682 | return True; |
3683 | end if; | |
3684 | ||
3685 | when Division_Check => | |
3686 | if not Compile_Time_Known_Value (R) | |
3687 | or else Expr_Value (R) /= Uint_0 | |
3688 | then | |
3689 | return True; | |
3690 | end if; | |
2af58f67 | 3691 | |
3692 | when others => | |
3693 | raise Program_Error; | |
13dbf220 | 3694 | end case; |
3695 | ||
3696 | -- Here we have the optimizable case, warn if not short-circuited | |
3697 | ||
3698 | if K = N_Op_And or else K = N_Op_Or then | |
c4968aa2 | 3699 | Error_Msg_Warn := SPARK_Mode /= On; |
4098232e | 3700 | |
13dbf220 | 3701 | case Check is |
3702 | when Access_Check => | |
4098232e | 3703 | if GNATprove_Mode then |
3704 | Error_Msg_N | |
3705 | ("Constraint_Error might have been raised (access check)", | |
3706 | Parent (Nod)); | |
3707 | else | |
3708 | Error_Msg_N | |
3709 | ("Constraint_Error may be raised (access check)??", | |
3710 | Parent (Nod)); | |
3711 | end if; | |
3712 | ||
13dbf220 | 3713 | when Division_Check => |
4098232e | 3714 | if GNATprove_Mode then |
3715 | Error_Msg_N | |
3716 | ("Constraint_Error might have been raised (zero divide)", | |
3717 | Parent (Nod)); | |
3718 | else | |
3719 | Error_Msg_N | |
3720 | ("Constraint_Error may be raised (zero divide)??", | |
3721 | Parent (Nod)); | |
3722 | end if; | |
2af58f67 | 3723 | |
3724 | when others => | |
3725 | raise Program_Error; | |
13dbf220 | 3726 | end case; |
3727 | ||
3728 | if K = N_Op_And then | |
e977c0cf | 3729 | Error_Msg_N -- CODEFIX |
cb97ae5c | 3730 | ("use `AND THEN` instead of AND??", P); |
13dbf220 | 3731 | else |
e977c0cf | 3732 | Error_Msg_N -- CODEFIX |
cb97ae5c | 3733 | ("use `OR ELSE` instead of OR??", P); |
13dbf220 | 3734 | end if; |
3735 | ||
6fb3c314 | 3736 | -- If not short-circuited, we need the check |
13dbf220 | 3737 | |
3738 | return True; | |
3739 | ||
3740 | -- If short-circuited, we can omit the check | |
3741 | ||
3742 | else | |
3743 | return False; | |
3744 | end if; | |
3745 | end Check_Needed; | |
3746 | ||
ee6ba406 | 3747 | ----------------------------------- |
3748 | -- Check_Valid_Lvalue_Subscripts -- | |
3749 | ----------------------------------- | |
3750 | ||
3751 | procedure Check_Valid_Lvalue_Subscripts (Expr : Node_Id) is | |
3752 | begin | |
3753 | -- Skip this if range checks are suppressed | |
3754 | ||
3755 | if Range_Checks_Suppressed (Etype (Expr)) then | |
3756 | return; | |
3757 | ||
feff2f05 | 3758 | -- Only do this check for expressions that come from source. We assume |
3759 | -- that expander generated assignments explicitly include any necessary | |
3760 | -- checks. Note that this is not just an optimization, it avoids | |
3761 | -- infinite recursions! | |
ee6ba406 | 3762 | |
3763 | elsif not Comes_From_Source (Expr) then | |
3764 | return; | |
3765 | ||
3766 | -- For a selected component, check the prefix | |
3767 | ||
3768 | elsif Nkind (Expr) = N_Selected_Component then | |
3769 | Check_Valid_Lvalue_Subscripts (Prefix (Expr)); | |
3770 | return; | |
3771 | ||
3772 | -- Case of indexed component | |
3773 | ||
3774 | elsif Nkind (Expr) = N_Indexed_Component then | |
3775 | Apply_Subscript_Validity_Checks (Expr); | |
3776 | ||
feff2f05 | 3777 | -- Prefix may itself be or contain an indexed component, and these |
3778 | -- subscripts need checking as well. | |
ee6ba406 | 3779 | |
3780 | Check_Valid_Lvalue_Subscripts (Prefix (Expr)); | |
3781 | end if; | |
3782 | end Check_Valid_Lvalue_Subscripts; | |
3783 | ||
fa7497e8 | 3784 | ---------------------------------- |
3785 | -- Null_Exclusion_Static_Checks -- | |
3786 | ---------------------------------- | |
3787 | ||
3788 | procedure Null_Exclusion_Static_Checks (N : Node_Id) is | |
0577b0b1 | 3789 | Error_Node : Node_Id; |
3790 | Expr : Node_Id; | |
3791 | Has_Null : constant Boolean := Has_Null_Exclusion (N); | |
3792 | K : constant Node_Kind := Nkind (N); | |
3793 | Typ : Entity_Id; | |
fa7497e8 | 3794 | |
13dbf220 | 3795 | begin |
0577b0b1 | 3796 | pragma Assert |
3797 | (K = N_Component_Declaration | |
3798 | or else K = N_Discriminant_Specification | |
3799 | or else K = N_Function_Specification | |
3800 | or else K = N_Object_Declaration | |
3801 | or else K = N_Parameter_Specification); | |
3802 | ||
3803 | if K = N_Function_Specification then | |
3804 | Typ := Etype (Defining_Entity (N)); | |
3805 | else | |
3806 | Typ := Etype (Defining_Identifier (N)); | |
3807 | end if; | |
fa7497e8 | 3808 | |
13dbf220 | 3809 | case K is |
13dbf220 | 3810 | when N_Component_Declaration => |
3811 | if Present (Access_Definition (Component_Definition (N))) then | |
0577b0b1 | 3812 | Error_Node := Component_Definition (N); |
13dbf220 | 3813 | else |
0577b0b1 | 3814 | Error_Node := Subtype_Indication (Component_Definition (N)); |
13dbf220 | 3815 | end if; |
5329ca64 | 3816 | |
0577b0b1 | 3817 | when N_Discriminant_Specification => |
3818 | Error_Node := Discriminant_Type (N); | |
3819 | ||
3820 | when N_Function_Specification => | |
3821 | Error_Node := Result_Definition (N); | |
3822 | ||
3823 | when N_Object_Declaration => | |
3824 | Error_Node := Object_Definition (N); | |
3825 | ||
3826 | when N_Parameter_Specification => | |
3827 | Error_Node := Parameter_Type (N); | |
3828 | ||
13dbf220 | 3829 | when others => |
3830 | raise Program_Error; | |
3831 | end case; | |
5329ca64 | 3832 | |
0577b0b1 | 3833 | if Has_Null then |
5329ca64 | 3834 | |
0577b0b1 | 3835 | -- Enforce legality rule 3.10 (13): A null exclusion can only be |
3836 | -- applied to an access [sub]type. | |
5329ca64 | 3837 | |
0577b0b1 | 3838 | if not Is_Access_Type (Typ) then |
503f7fd3 | 3839 | Error_Msg_N |
00c403ee | 3840 | ("`NOT NULL` allowed only for an access type", Error_Node); |
5329ca64 | 3841 | |
feff2f05 | 3842 | -- Enforce legality rule RM 3.10(14/1): A null exclusion can only |
0577b0b1 | 3843 | -- be applied to a [sub]type that does not exclude null already. |
3844 | ||
3845 | elsif Can_Never_Be_Null (Typ) | |
d16989f1 | 3846 | and then Comes_From_Source (Typ) |
0577b0b1 | 3847 | then |
503f7fd3 | 3848 | Error_Msg_NE |
00c403ee | 3849 | ("`NOT NULL` not allowed (& already excludes null)", |
3850 | Error_Node, Typ); | |
0577b0b1 | 3851 | end if; |
13dbf220 | 3852 | end if; |
5329ca64 | 3853 | |
cc60bd16 | 3854 | -- Check that null-excluding objects are always initialized, except for |
3855 | -- deferred constants, for which the expression will appear in the full | |
3856 | -- declaration. | |
13dbf220 | 3857 | |
3858 | if K = N_Object_Declaration | |
84d0d4a5 | 3859 | and then No (Expression (N)) |
cc60bd16 | 3860 | and then not Constant_Present (N) |
feff2f05 | 3861 | and then not No_Initialization (N) |
13dbf220 | 3862 | then |
feff2f05 | 3863 | -- Add an expression that assigns null. This node is needed by |
3864 | -- Apply_Compile_Time_Constraint_Error, which will replace this with | |
3865 | -- a Constraint_Error node. | |
13dbf220 | 3866 | |
3867 | Set_Expression (N, Make_Null (Sloc (N))); | |
3868 | Set_Etype (Expression (N), Etype (Defining_Identifier (N))); | |
5329ca64 | 3869 | |
13dbf220 | 3870 | Apply_Compile_Time_Constraint_Error |
3871 | (N => Expression (N), | |
cb97ae5c | 3872 | Msg => |
3873 | "(Ada 2005) null-excluding objects must be initialized??", | |
13dbf220 | 3874 | Reason => CE_Null_Not_Allowed); |
3875 | end if; | |
5329ca64 | 3876 | |
cc60bd16 | 3877 | -- Check that a null-excluding component, formal or object is not being |
3878 | -- assigned a null value. Otherwise generate a warning message and | |
2c145f84 | 3879 | -- replace Expression (N) by an N_Constraint_Error node. |
13dbf220 | 3880 | |
0577b0b1 | 3881 | if K /= N_Function_Specification then |
3882 | Expr := Expression (N); | |
5329ca64 | 3883 | |
2af58f67 | 3884 | if Present (Expr) and then Known_Null (Expr) then |
13dbf220 | 3885 | case K is |
0577b0b1 | 3886 | when N_Component_Declaration | |
3887 | N_Discriminant_Specification => | |
7189d17f | 3888 | Apply_Compile_Time_Constraint_Error |
0577b0b1 | 3889 | (N => Expr, |
4098232e | 3890 | Msg => "(Ada 2005) null not allowed " |
3891 | & "in null-excluding components??", | |
0577b0b1 | 3892 | Reason => CE_Null_Not_Allowed); |
5329ca64 | 3893 | |
0577b0b1 | 3894 | when N_Object_Declaration => |
7189d17f | 3895 | Apply_Compile_Time_Constraint_Error |
0577b0b1 | 3896 | (N => Expr, |
4098232e | 3897 | Msg => "(Ada 2005) null not allowed " |
3898 | & "in null-excluding objects?", | |
0577b0b1 | 3899 | Reason => CE_Null_Not_Allowed); |
5329ca64 | 3900 | |
0577b0b1 | 3901 | when N_Parameter_Specification => |
7189d17f | 3902 | Apply_Compile_Time_Constraint_Error |
0577b0b1 | 3903 | (N => Expr, |
4098232e | 3904 | Msg => "(Ada 2005) null not allowed " |
3905 | & "in null-excluding formals??", | |
0577b0b1 | 3906 | Reason => CE_Null_Not_Allowed); |
13dbf220 | 3907 | |
3908 | when others => | |
3909 | null; | |
5329ca64 | 3910 | end case; |
3911 | end if; | |
0577b0b1 | 3912 | end if; |
fa7497e8 | 3913 | end Null_Exclusion_Static_Checks; |
3914 | ||
9dfe12ae | 3915 | ---------------------------------- |
3916 | -- Conditional_Statements_Begin -- | |
3917 | ---------------------------------- | |
3918 | ||
3919 | procedure Conditional_Statements_Begin is | |
3920 | begin | |
3921 | Saved_Checks_TOS := Saved_Checks_TOS + 1; | |
3922 | ||
feff2f05 | 3923 | -- If stack overflows, kill all checks, that way we know to simply reset |
3924 | -- the number of saved checks to zero on return. This should never occur | |
3925 | -- in practice. | |
9dfe12ae | 3926 | |
3927 | if Saved_Checks_TOS > Saved_Checks_Stack'Last then | |
3928 | Kill_All_Checks; | |
3929 | ||
feff2f05 | 3930 | -- In the normal case, we just make a new stack entry saving the current |
3931 | -- number of saved checks for a later restore. | |
9dfe12ae | 3932 | |
3933 | else | |
3934 | Saved_Checks_Stack (Saved_Checks_TOS) := Num_Saved_Checks; | |
3935 | ||
3936 | if Debug_Flag_CC then | |
3937 | w ("Conditional_Statements_Begin: Num_Saved_Checks = ", | |
3938 | Num_Saved_Checks); | |
3939 | end if; | |
3940 | end if; | |
3941 | end Conditional_Statements_Begin; | |
3942 | ||
3943 | -------------------------------- | |
3944 | -- Conditional_Statements_End -- | |
3945 | -------------------------------- | |
3946 | ||
3947 | procedure Conditional_Statements_End is | |
3948 | begin | |
3949 | pragma Assert (Saved_Checks_TOS > 0); | |
3950 | ||
feff2f05 | 3951 | -- If the saved checks stack overflowed, then we killed all checks, so |
3952 | -- setting the number of saved checks back to zero is correct. This | |
3953 | -- should never occur in practice. | |
9dfe12ae | 3954 | |
3955 | if Saved_Checks_TOS > Saved_Checks_Stack'Last then | |
3956 | Num_Saved_Checks := 0; | |
3957 | ||
feff2f05 | 3958 | -- In the normal case, restore the number of saved checks from the top |
3959 | -- stack entry. | |
9dfe12ae | 3960 | |
3961 | else | |
3962 | Num_Saved_Checks := Saved_Checks_Stack (Saved_Checks_TOS); | |
20cf157b | 3963 | |
9dfe12ae | 3964 | if Debug_Flag_CC then |
3965 | w ("Conditional_Statements_End: Num_Saved_Checks = ", | |
3966 | Num_Saved_Checks); | |
3967 | end if; | |
3968 | end if; | |
3969 | ||
3970 | Saved_Checks_TOS := Saved_Checks_TOS - 1; | |
3971 | end Conditional_Statements_End; | |
3972 | ||
3cce7f32 | 3973 | ------------------------- |
3974 | -- Convert_From_Bignum -- | |
3975 | ------------------------- | |
3976 | ||
3977 | function Convert_From_Bignum (N : Node_Id) return Node_Id is | |
3978 | Loc : constant Source_Ptr := Sloc (N); | |
3979 | ||
3980 | begin | |
3981 | pragma Assert (Is_RTE (Etype (N), RE_Bignum)); | |
3982 | ||
3983 | -- Construct call From Bignum | |
3984 | ||
3985 | return | |
3986 | Make_Function_Call (Loc, | |
3987 | Name => | |
3988 | New_Occurrence_Of (RTE (RE_From_Bignum), Loc), | |
3989 | Parameter_Associations => New_List (Relocate_Node (N))); | |
3990 | end Convert_From_Bignum; | |
3991 | ||
3992 | ----------------------- | |
3993 | -- Convert_To_Bignum -- | |
3994 | ----------------------- | |
3995 | ||
3996 | function Convert_To_Bignum (N : Node_Id) return Node_Id is | |
3997 | Loc : constant Source_Ptr := Sloc (N); | |
3998 | ||
3999 | begin | |
0326b4d4 | 4000 | -- Nothing to do if Bignum already except call Relocate_Node |
3cce7f32 | 4001 | |
4002 | if Is_RTE (Etype (N), RE_Bignum) then | |
4003 | return Relocate_Node (N); | |
4004 | ||
21a55437 | 4005 | -- Otherwise construct call to To_Bignum, converting the operand to the |
4006 | -- required Long_Long_Integer form. | |
3cce7f32 | 4007 | |
4008 | else | |
4009 | pragma Assert (Is_Signed_Integer_Type (Etype (N))); | |
4010 | return | |
4011 | Make_Function_Call (Loc, | |
4012 | Name => | |
4013 | New_Occurrence_Of (RTE (RE_To_Bignum), Loc), | |
4014 | Parameter_Associations => New_List ( | |
4015 | Convert_To (Standard_Long_Long_Integer, Relocate_Node (N)))); | |
4016 | end if; | |
4017 | end Convert_To_Bignum; | |
4018 | ||
ee6ba406 | 4019 | --------------------- |
4020 | -- Determine_Range -- | |
4021 | --------------------- | |
4022 | ||
6af1bdbc | 4023 | Cache_Size : constant := 2 ** 10; |
ee6ba406 | 4024 | type Cache_Index is range 0 .. Cache_Size - 1; |
4025 | -- Determine size of below cache (power of 2 is more efficient!) | |
4026 | ||
4027 | Determine_Range_Cache_N : array (Cache_Index) of Node_Id; | |
9c486805 | 4028 | Determine_Range_Cache_V : array (Cache_Index) of Boolean; |
ee6ba406 | 4029 | Determine_Range_Cache_Lo : array (Cache_Index) of Uint; |
4030 | Determine_Range_Cache_Hi : array (Cache_Index) of Uint; | |
feff2f05 | 4031 | -- The above arrays are used to implement a small direct cache for |
4032 | -- Determine_Range calls. Because of the way Determine_Range recursively | |
4033 | -- traces subexpressions, and because overflow checking calls the routine | |
4034 | -- on the way up the tree, a quadratic behavior can otherwise be | |
4035 | -- encountered in large expressions. The cache entry for node N is stored | |
4036 | -- in the (N mod Cache_Size) entry, and can be validated by checking the | |
9c486805 | 4037 | -- actual node value stored there. The Range_Cache_V array records the |
4038 | -- setting of Assume_Valid for the cache entry. | |
ee6ba406 | 4039 | |
4040 | procedure Determine_Range | |
9c486805 | 4041 | (N : Node_Id; |
4042 | OK : out Boolean; | |
4043 | Lo : out Uint; | |
4044 | Hi : out Uint; | |
4045 | Assume_Valid : Boolean := False) | |
ee6ba406 | 4046 | is |
e254d721 | 4047 | Typ : Entity_Id := Etype (N); |
4048 | -- Type to use, may get reset to base type for possibly invalid entity | |
8880be85 | 4049 | |
4050 | Lo_Left : Uint; | |
4051 | Hi_Left : Uint; | |
4052 | -- Lo and Hi bounds of left operand | |
ee6ba406 | 4053 | |
ee6ba406 | 4054 | Lo_Right : Uint; |
ee6ba406 | 4055 | Hi_Right : Uint; |
8880be85 | 4056 | -- Lo and Hi bounds of right (or only) operand |
4057 | ||
4058 | Bound : Node_Id; | |
4059 | -- Temp variable used to hold a bound node | |
4060 | ||
4061 | Hbound : Uint; | |
4062 | -- High bound of base type of expression | |
4063 | ||
4064 | Lor : Uint; | |
4065 | Hir : Uint; | |
4066 | -- Refined values for low and high bounds, after tightening | |
4067 | ||
4068 | OK1 : Boolean; | |
4069 | -- Used in lower level calls to indicate if call succeeded | |
4070 | ||
4071 | Cindex : Cache_Index; | |
4072 | -- Used to search cache | |
ee6ba406 | 4073 | |
094ed68e | 4074 | Btyp : Entity_Id; |
4075 | -- Base type | |
4076 | ||
ee6ba406 | 4077 | function OK_Operands return Boolean; |
4078 | -- Used for binary operators. Determines the ranges of the left and | |
4079 | -- right operands, and if they are both OK, returns True, and puts | |
341bd953 | 4080 | -- the results in Lo_Right, Hi_Right, Lo_Left, Hi_Left. |
ee6ba406 | 4081 | |
4082 | ----------------- | |
4083 | -- OK_Operands -- | |
4084 | ----------------- | |
4085 | ||
4086 | function OK_Operands return Boolean is | |
4087 | begin | |
9c486805 | 4088 | Determine_Range |
4089 | (Left_Opnd (N), OK1, Lo_Left, Hi_Left, Assume_Valid); | |
ee6ba406 | 4090 | |
4091 | if not OK1 then | |
4092 | return False; | |
4093 | end if; | |
4094 | ||
9c486805 | 4095 | Determine_Range |
4096 | (Right_Opnd (N), OK1, Lo_Right, Hi_Right, Assume_Valid); | |
ee6ba406 | 4097 | return OK1; |
4098 | end OK_Operands; | |
4099 | ||
4100 | -- Start of processing for Determine_Range | |
4101 | ||
4102 | begin | |
87bdc21d | 4103 | -- For temporary constants internally generated to remove side effects |
4104 | -- we must use the corresponding expression to determine the range of | |
4105 | -- the expression. | |
4106 | ||
4107 | if Is_Entity_Name (N) | |
4108 | and then Nkind (Parent (Entity (N))) = N_Object_Declaration | |
4109 | and then Ekind (Entity (N)) = E_Constant | |
4110 | and then Is_Internal_Name (Chars (Entity (N))) | |
4111 | then | |
4112 | Determine_Range | |
4113 | (Expression (Parent (Entity (N))), OK, Lo, Hi, Assume_Valid); | |
4114 | return; | |
4115 | end if; | |
4116 | ||
ee6ba406 | 4117 | -- Prevent junk warnings by initializing range variables |
4118 | ||
4119 | Lo := No_Uint; | |
4120 | Hi := No_Uint; | |
4121 | Lor := No_Uint; | |
4122 | Hir := No_Uint; | |
4123 | ||
a781c0fc | 4124 | -- If type is not defined, we can't determine its range |
ee6ba406 | 4125 | |
a781c0fc | 4126 | if No (Typ) |
4127 | ||
4128 | -- We don't deal with anything except discrete types | |
4129 | ||
4130 | or else not Is_Discrete_Type (Typ) | |
4131 | ||
4132 | -- Ignore type for which an error has been posted, since range in | |
4133 | -- this case may well be a bogosity deriving from the error. Also | |
4134 | -- ignore if error posted on the reference node. | |
4135 | ||
4136 | or else Error_Posted (N) or else Error_Posted (Typ) | |
ee6ba406 | 4137 | then |
4138 | OK := False; | |
4139 | return; | |
4140 | end if; | |
4141 | ||
4142 | -- For all other cases, we can determine the range | |
4143 | ||
4144 | OK := True; | |
4145 | ||
feff2f05 | 4146 | -- If value is compile time known, then the possible range is the one |
4147 | -- value that we know this expression definitely has! | |
ee6ba406 | 4148 | |
4149 | if Compile_Time_Known_Value (N) then | |
4150 | Lo := Expr_Value (N); | |
4151 | Hi := Lo; | |
4152 | return; | |
4153 | end if; | |
4154 | ||
4155 | -- Return if already in the cache | |
4156 | ||
4157 | Cindex := Cache_Index (N mod Cache_Size); | |
4158 | ||
9c486805 | 4159 | if Determine_Range_Cache_N (Cindex) = N |
4160 | and then | |
4161 | Determine_Range_Cache_V (Cindex) = Assume_Valid | |
4162 | then | |
ee6ba406 | 4163 | Lo := Determine_Range_Cache_Lo (Cindex); |
4164 | Hi := Determine_Range_Cache_Hi (Cindex); | |
4165 | return; | |
4166 | end if; | |
4167 | ||
feff2f05 | 4168 | -- Otherwise, start by finding the bounds of the type of the expression, |
4169 | -- the value cannot be outside this range (if it is, then we have an | |
4170 | -- overflow situation, which is a separate check, we are talking here | |
4171 | -- only about the expression value). | |
ee6ba406 | 4172 | |
341bd953 | 4173 | -- First a check, never try to find the bounds of a generic type, since |
4174 | -- these bounds are always junk values, and it is only valid to look at | |
4175 | -- the bounds in an instance. | |
4176 | ||
4177 | if Is_Generic_Type (Typ) then | |
4178 | OK := False; | |
4179 | return; | |
4180 | end if; | |
4181 | ||
9c486805 | 4182 | -- First step, change to use base type unless we know the value is valid |
e254d721 | 4183 | |
9c486805 | 4184 | if (Is_Entity_Name (N) and then Is_Known_Valid (Entity (N))) |
4185 | or else Assume_No_Invalid_Values | |
4186 | or else Assume_Valid | |
e254d721 | 4187 | then |
9c486805 | 4188 | null; |
4189 | else | |
4190 | Typ := Underlying_Type (Base_Type (Typ)); | |
e254d721 | 4191 | end if; |
4192 | ||
094ed68e | 4193 | -- Retrieve the base type. Handle the case where the base type is a |
4194 | -- private enumeration type. | |
4195 | ||
4196 | Btyp := Base_Type (Typ); | |
4197 | ||
4198 | if Is_Private_Type (Btyp) and then Present (Full_View (Btyp)) then | |
4199 | Btyp := Full_View (Btyp); | |
4200 | end if; | |
4201 | ||
feff2f05 | 4202 | -- We use the actual bound unless it is dynamic, in which case use the |
4203 | -- corresponding base type bound if possible. If we can't get a bound | |
4204 | -- then we figure we can't determine the range (a peculiar case, that | |
4205 | -- perhaps cannot happen, but there is no point in bombing in this | |
4206 | -- optimization circuit. | |
8880be85 | 4207 | |
4208 | -- First the low bound | |
ee6ba406 | 4209 | |
4210 | Bound := Type_Low_Bound (Typ); | |
4211 | ||
4212 | if Compile_Time_Known_Value (Bound) then | |
4213 | Lo := Expr_Value (Bound); | |
4214 | ||
094ed68e | 4215 | elsif Compile_Time_Known_Value (Type_Low_Bound (Btyp)) then |
4216 | Lo := Expr_Value (Type_Low_Bound (Btyp)); | |
ee6ba406 | 4217 | |
4218 | else | |
4219 | OK := False; | |
4220 | return; | |
4221 | end if; | |
4222 | ||
8880be85 | 4223 | -- Now the high bound |
4224 | ||
ee6ba406 | 4225 | Bound := Type_High_Bound (Typ); |
4226 | ||
8880be85 | 4227 | -- We need the high bound of the base type later on, and this should |
4228 | -- always be compile time known. Again, it is not clear that this | |
4229 | -- can ever be false, but no point in bombing. | |
ee6ba406 | 4230 | |
094ed68e | 4231 | if Compile_Time_Known_Value (Type_High_Bound (Btyp)) then |
4232 | Hbound := Expr_Value (Type_High_Bound (Btyp)); | |
ee6ba406 | 4233 | Hi := Hbound; |
4234 | ||
4235 | else | |
4236 | OK := False; | |
4237 | return; | |
4238 | end if; | |
4239 | ||
feff2f05 | 4240 | -- If we have a static subtype, then that may have a tighter bound so |
4241 | -- use the upper bound of the subtype instead in this case. | |
8880be85 | 4242 | |
4243 | if Compile_Time_Known_Value (Bound) then | |
4244 | Hi := Expr_Value (Bound); | |
4245 | end if; | |
4246 | ||
feff2f05 | 4247 | -- We may be able to refine this value in certain situations. If any |
4248 | -- refinement is possible, then Lor and Hir are set to possibly tighter | |
4249 | -- bounds, and OK1 is set to True. | |
ee6ba406 | 4250 | |
4251 | case Nkind (N) is | |
4252 | ||
4253 | -- For unary plus, result is limited by range of operand | |
4254 | ||
4255 | when N_Op_Plus => | |
9c486805 | 4256 | Determine_Range |
4257 | (Right_Opnd (N), OK1, Lor, Hir, Assume_Valid); | |
ee6ba406 | 4258 | |
4259 | -- For unary minus, determine range of operand, and negate it | |
4260 | ||
4261 | when N_Op_Minus => | |
9c486805 | 4262 | Determine_Range |
4263 | (Right_Opnd (N), OK1, Lo_Right, Hi_Right, Assume_Valid); | |
ee6ba406 | 4264 | |
4265 | if OK1 then | |
4266 | Lor := -Hi_Right; | |
4267 | Hir := -Lo_Right; | |
4268 | end if; | |
4269 | ||
4270 | -- For binary addition, get range of each operand and do the | |
4271 | -- addition to get the result range. | |
4272 | ||
4273 | when N_Op_Add => | |
4274 | if OK_Operands then | |
4275 | Lor := Lo_Left + Lo_Right; | |
4276 | Hir := Hi_Left + Hi_Right; | |
4277 | end if; | |
4278 | ||
feff2f05 | 4279 | -- Division is tricky. The only case we consider is where the right |
4280 | -- operand is a positive constant, and in this case we simply divide | |
4281 | -- the bounds of the left operand | |
ee6ba406 | 4282 | |
4283 | when N_Op_Divide => | |
4284 | if OK_Operands then | |
4285 | if Lo_Right = Hi_Right | |
4286 | and then Lo_Right > 0 | |
4287 | then | |
4288 | Lor := Lo_Left / Lo_Right; | |
4289 | Hir := Hi_Left / Lo_Right; | |
ee6ba406 | 4290 | else |
4291 | OK1 := False; | |
4292 | end if; | |
4293 | end if; | |
4294 | ||
feff2f05 | 4295 | -- For binary subtraction, get range of each operand and do the worst |
4296 | -- case subtraction to get the result range. | |
ee6ba406 | 4297 | |
4298 | when N_Op_Subtract => | |
4299 | if OK_Operands then | |
4300 | Lor := Lo_Left - Hi_Right; | |
4301 | Hir := Hi_Left - Lo_Right; | |
4302 | end if; | |
4303 | ||
feff2f05 | 4304 | -- For MOD, if right operand is a positive constant, then result must |
4305 | -- be in the allowable range of mod results. | |
ee6ba406 | 4306 | |
4307 | when N_Op_Mod => | |
4308 | if OK_Operands then | |
9dfe12ae | 4309 | if Lo_Right = Hi_Right |
4310 | and then Lo_Right /= 0 | |
4311 | then | |
ee6ba406 | 4312 | if Lo_Right > 0 then |
4313 | Lor := Uint_0; | |
4314 | Hir := Lo_Right - 1; | |
4315 | ||
9dfe12ae | 4316 | else -- Lo_Right < 0 |
ee6ba406 | 4317 | Lor := Lo_Right + 1; |
4318 | Hir := Uint_0; | |
4319 | end if; | |
4320 | ||
4321 | else | |
4322 | OK1 := False; | |
4323 | end if; | |
4324 | end if; | |
4325 | ||
feff2f05 | 4326 | -- For REM, if right operand is a positive constant, then result must |
4327 | -- be in the allowable range of mod results. | |
ee6ba406 | 4328 | |
4329 | when N_Op_Rem => | |
4330 | if OK_Operands then | |
9dfe12ae | 4331 | if Lo_Right = Hi_Right |
4332 | and then Lo_Right /= 0 | |
4333 | then | |
ee6ba406 | 4334 | declare |
4335 | Dval : constant Uint := (abs Lo_Right) - 1; | |
4336 | ||
4337 | begin | |
4338 | -- The sign of the result depends on the sign of the | |
4339 | -- dividend (but not on the sign of the divisor, hence | |
4340 | -- the abs operation above). | |
4341 | ||
4342 | if Lo_Left < 0 then | |
4343 | Lor := -Dval; | |
4344 | else | |
4345 | Lor := Uint_0; | |
4346 | end if; | |
4347 | ||
4348 | if Hi_Left < 0 then | |
4349 | Hir := Uint_0; | |
4350 | else | |
4351 | Hir := Dval; | |
4352 | end if; | |
4353 | end; | |
4354 | ||
4355 | else | |
4356 | OK1 := False; | |
4357 | end if; | |
4358 | end if; | |
4359 | ||
4360 | -- Attribute reference cases | |
4361 | ||
4362 | when N_Attribute_Reference => | |
4363 | case Attribute_Name (N) is | |
4364 | ||
4365 | -- For Pos/Val attributes, we can refine the range using the | |
ddbf7f2e | 4366 | -- possible range of values of the attribute expression. |
ee6ba406 | 4367 | |
4368 | when Name_Pos | Name_Val => | |
9c486805 | 4369 | Determine_Range |
4370 | (First (Expressions (N)), OK1, Lor, Hir, Assume_Valid); | |
ee6ba406 | 4371 | |
4372 | -- For Length attribute, use the bounds of the corresponding | |
4373 | -- index type to refine the range. | |
4374 | ||
4375 | when Name_Length => | |
4376 | declare | |
4377 | Atyp : Entity_Id := Etype (Prefix (N)); | |
4378 | Inum : Nat; | |
4379 | Indx : Node_Id; | |
4380 | ||
4381 | LL, LU : Uint; | |
4382 | UL, UU : Uint; | |
4383 | ||
4384 | begin | |
4385 | if Is_Access_Type (Atyp) then | |
4386 | Atyp := Designated_Type (Atyp); | |
4387 | end if; | |
4388 | ||
4389 | -- For string literal, we know exact value | |
4390 | ||
4391 | if Ekind (Atyp) = E_String_Literal_Subtype then | |
4392 | OK := True; | |
4393 | Lo := String_Literal_Length (Atyp); | |
4394 | Hi := String_Literal_Length (Atyp); | |
4395 | return; | |
4396 | end if; | |
4397 | ||
4398 | -- Otherwise check for expression given | |
4399 | ||
4400 | if No (Expressions (N)) then | |
4401 | Inum := 1; | |
4402 | else | |
4403 | Inum := | |
4404 | UI_To_Int (Expr_Value (First (Expressions (N)))); | |
4405 | end if; | |
4406 | ||
4407 | Indx := First_Index (Atyp); | |
4408 | for J in 2 .. Inum loop | |
4409 | Indx := Next_Index (Indx); | |
4410 | end loop; | |
4411 | ||
9116df93 | 4412 | -- If the index type is a formal type or derived from |
c8da6114 | 4413 | -- one, the bounds are not static. |
4414 | ||
4415 | if Is_Generic_Type (Root_Type (Etype (Indx))) then | |
4416 | OK := False; | |
4417 | return; | |
4418 | end if; | |
4419 | ||
ee6ba406 | 4420 | Determine_Range |
9c486805 | 4421 | (Type_Low_Bound (Etype (Indx)), OK1, LL, LU, |
4422 | Assume_Valid); | |
ee6ba406 | 4423 | |
4424 | if OK1 then | |
4425 | Determine_Range | |
9c486805 | 4426 | (Type_High_Bound (Etype (Indx)), OK1, UL, UU, |
4427 | Assume_Valid); | |
ee6ba406 | 4428 | |
4429 | if OK1 then | |
4430 | ||
4431 | -- The maximum value for Length is the biggest | |
4432 | -- possible gap between the values of the bounds. | |
4433 | -- But of course, this value cannot be negative. | |
4434 | ||
9c486805 | 4435 | Hir := UI_Max (Uint_0, UU - LL + 1); |
ee6ba406 | 4436 | |
4437 | -- For constrained arrays, the minimum value for | |
4438 | -- Length is taken from the actual value of the | |
9116df93 | 4439 | -- bounds, since the index will be exactly of this |
4440 | -- subtype. | |
ee6ba406 | 4441 | |
4442 | if Is_Constrained (Atyp) then | |
9c486805 | 4443 | Lor := UI_Max (Uint_0, UL - LU + 1); |
ee6ba406 | 4444 | |
4445 | -- For an unconstrained array, the minimum value | |
4446 | -- for length is always zero. | |
4447 | ||
4448 | else | |
4449 | Lor := Uint_0; | |
4450 | end if; | |
4451 | end if; | |
4452 | end if; | |
4453 | end; | |
4454 | ||
4455 | -- No special handling for other attributes | |
9116df93 | 4456 | -- Probably more opportunities exist here??? |
ee6ba406 | 4457 | |
4458 | when others => | |
4459 | OK1 := False; | |
4460 | ||
4461 | end case; | |
4462 | ||
feff2f05 | 4463 | -- For type conversion from one discrete type to another, we can |
4464 | -- refine the range using the converted value. | |
ee6ba406 | 4465 | |
4466 | when N_Type_Conversion => | |
9c486805 | 4467 | Determine_Range (Expression (N), OK1, Lor, Hir, Assume_Valid); |
ee6ba406 | 4468 | |
4469 | -- Nothing special to do for all other expression kinds | |
4470 | ||
4471 | when others => | |
4472 | OK1 := False; | |
4473 | Lor := No_Uint; | |
4474 | Hir := No_Uint; | |
4475 | end case; | |
4476 | ||
9116df93 | 4477 | -- At this stage, if OK1 is true, then we know that the actual result of |
4478 | -- the computed expression is in the range Lor .. Hir. We can use this | |
4479 | -- to restrict the possible range of results. | |
ee6ba406 | 4480 | |
4481 | if OK1 then | |
4482 | ||
9116df93 | 4483 | -- If the refined value of the low bound is greater than the type |
4484 | -- high bound, then reset it to the more restrictive value. However, | |
4485 | -- we do NOT do this for the case of a modular type where the | |
4486 | -- possible upper bound on the value is above the base type high | |
4487 | -- bound, because that means the result could wrap. | |
ee6ba406 | 4488 | |
4489 | if Lor > Lo | |
9116df93 | 4490 | and then not (Is_Modular_Integer_Type (Typ) and then Hir > Hbound) |
ee6ba406 | 4491 | then |
4492 | Lo := Lor; | |
4493 | end if; | |
4494 | ||
9116df93 | 4495 | -- Similarly, if the refined value of the high bound is less than the |
4496 | -- value so far, then reset it to the more restrictive value. Again, | |
4497 | -- we do not do this if the refined low bound is negative for a | |
4498 | -- modular type, since this would wrap. | |
ee6ba406 | 4499 | |
4500 | if Hir < Hi | |
9116df93 | 4501 | and then not (Is_Modular_Integer_Type (Typ) and then Lor < Uint_0) |
ee6ba406 | 4502 | then |
4503 | Hi := Hir; | |
4504 | end if; | |
4505 | end if; | |
4506 | ||
4507 | -- Set cache entry for future call and we are all done | |
4508 | ||
4509 | Determine_Range_Cache_N (Cindex) := N; | |
9c486805 | 4510 | Determine_Range_Cache_V (Cindex) := Assume_Valid; |
ee6ba406 | 4511 | Determine_Range_Cache_Lo (Cindex) := Lo; |
4512 | Determine_Range_Cache_Hi (Cindex) := Hi; | |
4513 | return; | |
4514 | ||
9116df93 | 4515 | -- If any exception occurs, it means that we have some bug in the compiler, |
4516 | -- possibly triggered by a previous error, or by some unforeseen peculiar | |
ee6ba406 | 4517 | -- occurrence. However, this is only an optimization attempt, so there is |
4518 | -- really no point in crashing the compiler. Instead we just decide, too | |
4519 | -- bad, we can't figure out a range in this case after all. | |
4520 | ||
4521 | exception | |
4522 | when others => | |
4523 | ||
4524 | -- Debug flag K disables this behavior (useful for debugging) | |
4525 | ||
4526 | if Debug_Flag_K then | |
4527 | raise; | |
4528 | else | |
4529 | OK := False; | |
4530 | Lo := No_Uint; | |
4531 | Hi := No_Uint; | |
4532 | return; | |
4533 | end if; | |
ee6ba406 | 4534 | end Determine_Range; |
4535 | ||
4536 | ------------------------------------ | |
4537 | -- Discriminant_Checks_Suppressed -- | |
4538 | ------------------------------------ | |
4539 | ||
4540 | function Discriminant_Checks_Suppressed (E : Entity_Id) return Boolean is | |
4541 | begin | |
9dfe12ae | 4542 | if Present (E) then |
4543 | if Is_Unchecked_Union (E) then | |
4544 | return True; | |
4545 | elsif Checks_May_Be_Suppressed (E) then | |
4546 | return Is_Check_Suppressed (E, Discriminant_Check); | |
4547 | end if; | |
4548 | end if; | |
4549 | ||
fafc6b97 | 4550 | return Scope_Suppress.Suppress (Discriminant_Check); |
ee6ba406 | 4551 | end Discriminant_Checks_Suppressed; |
4552 | ||
4553 | -------------------------------- | |
4554 | -- Division_Checks_Suppressed -- | |
4555 | -------------------------------- | |
4556 | ||
4557 | function Division_Checks_Suppressed (E : Entity_Id) return Boolean is | |
4558 | begin | |
9dfe12ae | 4559 | if Present (E) and then Checks_May_Be_Suppressed (E) then |
4560 | return Is_Check_Suppressed (E, Division_Check); | |
4561 | else | |
fafc6b97 | 4562 | return Scope_Suppress.Suppress (Division_Check); |
9dfe12ae | 4563 | end if; |
ee6ba406 | 4564 | end Division_Checks_Suppressed; |
4565 | ||
4566 | ----------------------------------- | |
4567 | -- Elaboration_Checks_Suppressed -- | |
4568 | ----------------------------------- | |
4569 | ||
4570 | function Elaboration_Checks_Suppressed (E : Entity_Id) return Boolean is | |
4571 | begin | |
38f5559f | 4572 | -- The complication in this routine is that if we are in the dynamic |
4573 | -- model of elaboration, we also check All_Checks, since All_Checks | |
4574 | -- does not set Elaboration_Check explicitly. | |
4575 | ||
9dfe12ae | 4576 | if Present (E) then |
4577 | if Kill_Elaboration_Checks (E) then | |
4578 | return True; | |
38f5559f | 4579 | |
9dfe12ae | 4580 | elsif Checks_May_Be_Suppressed (E) then |
38f5559f | 4581 | if Is_Check_Suppressed (E, Elaboration_Check) then |
4582 | return True; | |
4583 | elsif Dynamic_Elaboration_Checks then | |
4584 | return Is_Check_Suppressed (E, All_Checks); | |
4585 | else | |
4586 | return False; | |
4587 | end if; | |
9dfe12ae | 4588 | end if; |
4589 | end if; | |
4590 | ||
fafc6b97 | 4591 | if Scope_Suppress.Suppress (Elaboration_Check) then |
38f5559f | 4592 | return True; |
4593 | elsif Dynamic_Elaboration_Checks then | |
fafc6b97 | 4594 | return Scope_Suppress.Suppress (All_Checks); |
38f5559f | 4595 | else |
4596 | return False; | |
4597 | end if; | |
ee6ba406 | 4598 | end Elaboration_Checks_Suppressed; |
4599 | ||
9dfe12ae | 4600 | --------------------------- |
4601 | -- Enable_Overflow_Check -- | |
4602 | --------------------------- | |
4603 | ||
4604 | procedure Enable_Overflow_Check (N : Node_Id) is | |
3cce7f32 | 4605 | Typ : constant Entity_Id := Base_Type (Etype (N)); |
db415383 | 4606 | Mode : constant Overflow_Mode_Type := Overflow_Check_Mode; |
3cce7f32 | 4607 | Chk : Nat; |
4608 | OK : Boolean; | |
4609 | Ent : Entity_Id; | |
4610 | Ofs : Uint; | |
4611 | Lo : Uint; | |
4612 | Hi : Uint; | |
ee6ba406 | 4613 | |
ee6ba406 | 4614 | begin |
9dfe12ae | 4615 | if Debug_Flag_CC then |
4616 | w ("Enable_Overflow_Check for node ", Int (N)); | |
4617 | Write_Str (" Source location = "); | |
4618 | wl (Sloc (N)); | |
00c403ee | 4619 | pg (Union_Id (N)); |
ee6ba406 | 4620 | end if; |
ee6ba406 | 4621 | |
75209ec5 | 4622 | -- No check if overflow checks suppressed for type of node |
4623 | ||
0df9d43f | 4624 | if Overflow_Checks_Suppressed (Etype (N)) then |
75209ec5 | 4625 | return; |
4626 | ||
49260fa5 | 4627 | -- Nothing to do for unsigned integer types, which do not overflow |
4628 | ||
4629 | elsif Is_Modular_Integer_Type (Typ) then | |
4630 | return; | |
3cce7f32 | 4631 | end if; |
4632 | ||
0df9d43f | 4633 | -- This is the point at which processing for STRICT mode diverges |
21a55437 | 4634 | -- from processing for MINIMIZED/ELIMINATED modes. This divergence is |
4635 | -- probably more extreme that it needs to be, but what is going on here | |
4636 | -- is that when we introduced MINIMIZED/ELIMINATED modes, we wanted | |
0df9d43f | 4637 | -- to leave the processing for STRICT mode untouched. There were |
21a55437 | 4638 | -- two reasons for this. First it avoided any incompatible change of |
0df9d43f | 4639 | -- behavior. Second, it guaranteed that STRICT mode continued to be |
21a55437 | 4640 | -- legacy reliable. |
3cce7f32 | 4641 | |
0df9d43f | 4642 | -- The big difference is that in STRICT mode there is a fair amount of |
3cce7f32 | 4643 | -- circuitry to try to avoid setting the Do_Overflow_Check flag if we |
4644 | -- know that no check is needed. We skip all that in the two new modes, | |
4645 | -- since really overflow checking happens over a whole subtree, and we | |
4646 | -- do the corresponding optimizations later on when applying the checks. | |
4647 | ||
4648 | if Mode in Minimized_Or_Eliminated then | |
0df9d43f | 4649 | if not (Overflow_Checks_Suppressed (Etype (N))) |
4650 | and then not (Is_Entity_Name (N) | |
4651 | and then Overflow_Checks_Suppressed (Entity (N))) | |
4652 | then | |
4653 | Activate_Overflow_Check (N); | |
4654 | end if; | |
3cce7f32 | 4655 | |
4656 | if Debug_Flag_CC then | |
4657 | w ("Minimized/Eliminated mode"); | |
4658 | end if; | |
4659 | ||
4660 | return; | |
4661 | end if; | |
4662 | ||
0df9d43f | 4663 | -- Remainder of processing is for STRICT case, and is unchanged from |
691fe9e0 | 4664 | -- earlier versions preceding the addition of MINIMIZED/ELIMINATED. |
49260fa5 | 4665 | |
feff2f05 | 4666 | -- Nothing to do if the range of the result is known OK. We skip this |
4667 | -- for conversions, since the caller already did the check, and in any | |
4668 | -- case the condition for deleting the check for a type conversion is | |
cc60bd16 | 4669 | -- different. |
ee6ba406 | 4670 | |
3cce7f32 | 4671 | if Nkind (N) /= N_Type_Conversion then |
9c486805 | 4672 | Determine_Range (N, OK, Lo, Hi, Assume_Valid => True); |
ee6ba406 | 4673 | |
cc60bd16 | 4674 | -- Note in the test below that we assume that the range is not OK |
4675 | -- if a bound of the range is equal to that of the type. That's not | |
4676 | -- quite accurate but we do this for the following reasons: | |
ee6ba406 | 4677 | |
9dfe12ae | 4678 | -- a) The way that Determine_Range works, it will typically report |
4679 | -- the bounds of the value as being equal to the bounds of the | |
4680 | -- type, because it either can't tell anything more precise, or | |
4681 | -- does not think it is worth the effort to be more precise. | |
ee6ba406 | 4682 | |
9dfe12ae | 4683 | -- b) It is very unusual to have a situation in which this would |
4684 | -- generate an unnecessary overflow check (an example would be | |
4685 | -- a subtype with a range 0 .. Integer'Last - 1 to which the | |
cc60bd16 | 4686 | -- literal value one is added). |
ee6ba406 | 4687 | |
9dfe12ae | 4688 | -- c) The alternative is a lot of special casing in this routine |
4689 | -- which would partially duplicate Determine_Range processing. | |
ee6ba406 | 4690 | |
9dfe12ae | 4691 | if OK |
4692 | and then Lo > Expr_Value (Type_Low_Bound (Typ)) | |
4693 | and then Hi < Expr_Value (Type_High_Bound (Typ)) | |
4694 | then | |
4695 | if Debug_Flag_CC then | |
4696 | w ("No overflow check required"); | |
4697 | end if; | |
4698 | ||
4699 | return; | |
4700 | end if; | |
4701 | end if; | |
4702 | ||
feff2f05 | 4703 | -- If not in optimizing mode, set flag and we are done. We are also done |
4704 | -- (and just set the flag) if the type is not a discrete type, since it | |
4705 | -- is not worth the effort to eliminate checks for other than discrete | |
4706 | -- types. In addition, we take this same path if we have stored the | |
4707 | -- maximum number of checks possible already (a very unlikely situation, | |
4708 | -- but we do not want to blow up!) | |
9dfe12ae | 4709 | |
4710 | if Optimization_Level = 0 | |
4711 | or else not Is_Discrete_Type (Etype (N)) | |
4712 | or else Num_Saved_Checks = Saved_Checks'Last | |
ee6ba406 | 4713 | then |
00c403ee | 4714 | Activate_Overflow_Check (N); |
9dfe12ae | 4715 | |
4716 | if Debug_Flag_CC then | |
4717 | w ("Optimization off"); | |
4718 | end if; | |
4719 | ||
ee6ba406 | 4720 | return; |
9dfe12ae | 4721 | end if; |
ee6ba406 | 4722 | |
9dfe12ae | 4723 | -- Otherwise evaluate and check the expression |
4724 | ||
4725 | Find_Check | |
4726 | (Expr => N, | |
4727 | Check_Type => 'O', | |
4728 | Target_Type => Empty, | |
4729 | Entry_OK => OK, | |
4730 | Check_Num => Chk, | |
4731 | Ent => Ent, | |
4732 | Ofs => Ofs); | |
4733 | ||
4734 | if Debug_Flag_CC then | |
4735 | w ("Called Find_Check"); | |
4736 | w (" OK = ", OK); | |
4737 | ||
4738 | if OK then | |
4739 | w (" Check_Num = ", Chk); | |
4740 | w (" Ent = ", Int (Ent)); | |
4741 | Write_Str (" Ofs = "); | |
4742 | pid (Ofs); | |
4743 | end if; | |
4744 | end if; | |
ee6ba406 | 4745 | |
9dfe12ae | 4746 | -- If check is not of form to optimize, then set flag and we are done |
4747 | ||
4748 | if not OK then | |
00c403ee | 4749 | Activate_Overflow_Check (N); |
ee6ba406 | 4750 | return; |
9dfe12ae | 4751 | end if; |
ee6ba406 | 4752 | |
9dfe12ae | 4753 | -- If check is already performed, then return without setting flag |
4754 | ||
4755 | if Chk /= 0 then | |
4756 | if Debug_Flag_CC then | |
4757 | w ("Check suppressed!"); | |
4758 | end if; | |
ee6ba406 | 4759 | |
ee6ba406 | 4760 | return; |
9dfe12ae | 4761 | end if; |
ee6ba406 | 4762 | |
9dfe12ae | 4763 | -- Here we will make a new entry for the new check |
4764 | ||
00c403ee | 4765 | Activate_Overflow_Check (N); |
9dfe12ae | 4766 | Num_Saved_Checks := Num_Saved_Checks + 1; |
4767 | Saved_Checks (Num_Saved_Checks) := | |
4768 | (Killed => False, | |
4769 | Entity => Ent, | |
4770 | Offset => Ofs, | |
4771 | Check_Type => 'O', | |
4772 | Target_Type => Empty); | |
4773 | ||
4774 | if Debug_Flag_CC then | |
4775 | w ("Make new entry, check number = ", Num_Saved_Checks); | |
4776 | w (" Entity = ", Int (Ent)); | |
4777 | Write_Str (" Offset = "); | |
4778 | pid (Ofs); | |
4779 | w (" Check_Type = O"); | |
4780 | w (" Target_Type = Empty"); | |
4781 | end if; | |
ee6ba406 | 4782 | |
feff2f05 | 4783 | -- If we get an exception, then something went wrong, probably because of |
20cf157b | 4784 | -- an error in the structure of the tree due to an incorrect program. Or |
4785 | -- it may be a bug in the optimization circuit. In either case the safest | |
feff2f05 | 4786 | -- thing is simply to set the check flag unconditionally. |
9dfe12ae | 4787 | |
4788 | exception | |
4789 | when others => | |
00c403ee | 4790 | Activate_Overflow_Check (N); |
9dfe12ae | 4791 | |
4792 | if Debug_Flag_CC then | |
4793 | w (" exception occurred, overflow flag set"); | |
4794 | end if; | |
4795 | ||
4796 | return; | |
4797 | end Enable_Overflow_Check; | |
4798 | ||
4799 | ------------------------ | |
4800 | -- Enable_Range_Check -- | |
4801 | ------------------------ | |
4802 | ||
4803 | procedure Enable_Range_Check (N : Node_Id) is | |
4804 | Chk : Nat; | |
4805 | OK : Boolean; | |
4806 | Ent : Entity_Id; | |
4807 | Ofs : Uint; | |
4808 | Ttyp : Entity_Id; | |
4809 | P : Node_Id; | |
4810 | ||
4811 | begin | |
feff2f05 | 4812 | -- Return if unchecked type conversion with range check killed. In this |
4813 | -- case we never set the flag (that's what Kill_Range_Check is about!) | |
9dfe12ae | 4814 | |
4815 | if Nkind (N) = N_Unchecked_Type_Conversion | |
4816 | and then Kill_Range_Check (N) | |
ee6ba406 | 4817 | then |
4818 | return; | |
9dfe12ae | 4819 | end if; |
ee6ba406 | 4820 | |
55e8372b | 4821 | -- Do not set range check flag if parent is assignment statement or |
4822 | -- object declaration with Suppress_Assignment_Checks flag set | |
4823 | ||
4824 | if Nkind_In (Parent (N), N_Assignment_Statement, N_Object_Declaration) | |
4825 | and then Suppress_Assignment_Checks (Parent (N)) | |
4826 | then | |
4827 | return; | |
4828 | end if; | |
4829 | ||
0577b0b1 | 4830 | -- Check for various cases where we should suppress the range check |
4831 | ||
4832 | -- No check if range checks suppressed for type of node | |
4833 | ||
20cf157b | 4834 | if Present (Etype (N)) and then Range_Checks_Suppressed (Etype (N)) then |
0577b0b1 | 4835 | return; |
4836 | ||
4837 | -- No check if node is an entity name, and range checks are suppressed | |
4838 | -- for this entity, or for the type of this entity. | |
4839 | ||
4840 | elsif Is_Entity_Name (N) | |
4841 | and then (Range_Checks_Suppressed (Entity (N)) | |
20cf157b | 4842 | or else Range_Checks_Suppressed (Etype (Entity (N)))) |
0577b0b1 | 4843 | then |
4844 | return; | |
4845 | ||
4846 | -- No checks if index of array, and index checks are suppressed for | |
4847 | -- the array object or the type of the array. | |
4848 | ||
4849 | elsif Nkind (Parent (N)) = N_Indexed_Component then | |
4850 | declare | |
4851 | Pref : constant Node_Id := Prefix (Parent (N)); | |
4852 | begin | |
4853 | if Is_Entity_Name (Pref) | |
4854 | and then Index_Checks_Suppressed (Entity (Pref)) | |
4855 | then | |
4856 | return; | |
4857 | elsif Index_Checks_Suppressed (Etype (Pref)) then | |
4858 | return; | |
4859 | end if; | |
4860 | end; | |
4861 | end if; | |
4862 | ||
9dfe12ae | 4863 | -- Debug trace output |
ee6ba406 | 4864 | |
9dfe12ae | 4865 | if Debug_Flag_CC then |
4866 | w ("Enable_Range_Check for node ", Int (N)); | |
4867 | Write_Str (" Source location = "); | |
4868 | wl (Sloc (N)); | |
00c403ee | 4869 | pg (Union_Id (N)); |
9dfe12ae | 4870 | end if; |
4871 | ||
feff2f05 | 4872 | -- If not in optimizing mode, set flag and we are done. We are also done |
4873 | -- (and just set the flag) if the type is not a discrete type, since it | |
4874 | -- is not worth the effort to eliminate checks for other than discrete | |
4875 | -- types. In addition, we take this same path if we have stored the | |
4876 | -- maximum number of checks possible already (a very unlikely situation, | |
4877 | -- but we do not want to blow up!) | |
9dfe12ae | 4878 | |
4879 | if Optimization_Level = 0 | |
4880 | or else No (Etype (N)) | |
4881 | or else not Is_Discrete_Type (Etype (N)) | |
4882 | or else Num_Saved_Checks = Saved_Checks'Last | |
ee6ba406 | 4883 | then |
00c403ee | 4884 | Activate_Range_Check (N); |
9dfe12ae | 4885 | |
4886 | if Debug_Flag_CC then | |
4887 | w ("Optimization off"); | |
4888 | end if; | |
4889 | ||
ee6ba406 | 4890 | return; |
9dfe12ae | 4891 | end if; |
ee6ba406 | 4892 | |
9dfe12ae | 4893 | -- Otherwise find out the target type |
ee6ba406 | 4894 | |
9dfe12ae | 4895 | P := Parent (N); |
ee6ba406 | 4896 | |
9dfe12ae | 4897 | -- For assignment, use left side subtype |
4898 | ||
4899 | if Nkind (P) = N_Assignment_Statement | |
4900 | and then Expression (P) = N | |
4901 | then | |
4902 | Ttyp := Etype (Name (P)); | |
4903 | ||
4904 | -- For indexed component, use subscript subtype | |
4905 | ||
4906 | elsif Nkind (P) = N_Indexed_Component then | |
4907 | declare | |
4908 | Atyp : Entity_Id; | |
4909 | Indx : Node_Id; | |
4910 | Subs : Node_Id; | |
4911 | ||
4912 | begin | |
4913 | Atyp := Etype (Prefix (P)); | |
4914 | ||
4915 | if Is_Access_Type (Atyp) then | |
4916 | Atyp := Designated_Type (Atyp); | |
f07ea091 | 4917 | |
4918 | -- If the prefix is an access to an unconstrained array, | |
feff2f05 | 4919 | -- perform check unconditionally: it depends on the bounds of |
4920 | -- an object and we cannot currently recognize whether the test | |
4921 | -- may be redundant. | |
f07ea091 | 4922 | |
4923 | if not Is_Constrained (Atyp) then | |
00c403ee | 4924 | Activate_Range_Check (N); |
f07ea091 | 4925 | return; |
4926 | end if; | |
7189d17f | 4927 | |
feff2f05 | 4928 | -- Ditto if the prefix is an explicit dereference whose designated |
4929 | -- type is unconstrained. | |
7189d17f | 4930 | |
4931 | elsif Nkind (Prefix (P)) = N_Explicit_Dereference | |
4932 | and then not Is_Constrained (Atyp) | |
4933 | then | |
00c403ee | 4934 | Activate_Range_Check (N); |
7189d17f | 4935 | return; |
9dfe12ae | 4936 | end if; |
4937 | ||
4938 | Indx := First_Index (Atyp); | |
4939 | Subs := First (Expressions (P)); | |
4940 | loop | |
4941 | if Subs = N then | |
4942 | Ttyp := Etype (Indx); | |
4943 | exit; | |
4944 | end if; | |
4945 | ||
4946 | Next_Index (Indx); | |
4947 | Next (Subs); | |
4948 | end loop; | |
4949 | end; | |
4950 | ||
4951 | -- For now, ignore all other cases, they are not so interesting | |
4952 | ||
4953 | else | |
4954 | if Debug_Flag_CC then | |
4955 | w (" target type not found, flag set"); | |
4956 | end if; | |
4957 | ||
00c403ee | 4958 | Activate_Range_Check (N); |
9dfe12ae | 4959 | return; |
4960 | end if; | |
4961 | ||
4962 | -- Evaluate and check the expression | |
4963 | ||
4964 | Find_Check | |
4965 | (Expr => N, | |
4966 | Check_Type => 'R', | |
4967 | Target_Type => Ttyp, | |
4968 | Entry_OK => OK, | |
4969 | Check_Num => Chk, | |
4970 | Ent => Ent, | |
4971 | Ofs => Ofs); | |
4972 | ||
4973 | if Debug_Flag_CC then | |
4974 | w ("Called Find_Check"); | |
4975 | w ("Target_Typ = ", Int (Ttyp)); | |
4976 | w (" OK = ", OK); | |
4977 | ||
4978 | if OK then | |
4979 | w (" Check_Num = ", Chk); | |
4980 | w (" Ent = ", Int (Ent)); | |
4981 | Write_Str (" Ofs = "); | |
4982 | pid (Ofs); | |
4983 | end if; | |
4984 | end if; | |
4985 | ||
4986 | -- If check is not of form to optimize, then set flag and we are done | |
4987 | ||
4988 | if not OK then | |
4989 | if Debug_Flag_CC then | |
4990 | w (" expression not of optimizable type, flag set"); | |
4991 | end if; | |
4992 | ||
00c403ee | 4993 | Activate_Range_Check (N); |
9dfe12ae | 4994 | return; |
4995 | end if; | |
4996 | ||
4997 | -- If check is already performed, then return without setting flag | |
4998 | ||
4999 | if Chk /= 0 then | |
5000 | if Debug_Flag_CC then | |
5001 | w ("Check suppressed!"); | |
5002 | end if; | |
5003 | ||
5004 | return; | |
5005 | end if; | |
5006 | ||
5007 | -- Here we will make a new entry for the new check | |
5008 | ||
00c403ee | 5009 | Activate_Range_Check (N); |
9dfe12ae | 5010 | Num_Saved_Checks := Num_Saved_Checks + 1; |
5011 | Saved_Checks (Num_Saved_Checks) := | |
5012 | (Killed => False, | |
5013 | Entity => Ent, | |
5014 | Offset => Ofs, | |
5015 | Check_Type => 'R', | |
5016 | Target_Type => Ttyp); | |
5017 | ||
5018 | if Debug_Flag_CC then | |
5019 | w ("Make new entry, check number = ", Num_Saved_Checks); | |
5020 | w (" Entity = ", Int (Ent)); | |
5021 | Write_Str (" Offset = "); | |
5022 | pid (Ofs); | |
5023 | w (" Check_Type = R"); | |
5024 | w (" Target_Type = ", Int (Ttyp)); | |
00c403ee | 5025 | pg (Union_Id (Ttyp)); |
9dfe12ae | 5026 | end if; |
5027 | ||
feff2f05 | 5028 | -- If we get an exception, then something went wrong, probably because of |
5029 | -- an error in the structure of the tree due to an incorrect program. Or | |
5030 | -- it may be a bug in the optimization circuit. In either case the safest | |
5031 | -- thing is simply to set the check flag unconditionally. | |
9dfe12ae | 5032 | |
5033 | exception | |
5034 | when others => | |
00c403ee | 5035 | Activate_Range_Check (N); |
9dfe12ae | 5036 | |
5037 | if Debug_Flag_CC then | |
5038 | w (" exception occurred, range flag set"); | |
5039 | end if; | |
5040 | ||
5041 | return; | |
5042 | end Enable_Range_Check; | |
5043 | ||
5044 | ------------------ | |
5045 | -- Ensure_Valid -- | |
5046 | ------------------ | |
5047 | ||
5048 | procedure Ensure_Valid (Expr : Node_Id; Holes_OK : Boolean := False) is | |
5049 | Typ : constant Entity_Id := Etype (Expr); | |
5050 | ||
5051 | begin | |
5052 | -- Ignore call if we are not doing any validity checking | |
5053 | ||
5054 | if not Validity_Checks_On then | |
5055 | return; | |
5056 | ||
0577b0b1 | 5057 | -- Ignore call if range or validity checks suppressed on entity or type |
9dfe12ae | 5058 | |
0577b0b1 | 5059 | elsif Range_Or_Validity_Checks_Suppressed (Expr) then |
9dfe12ae | 5060 | return; |
5061 | ||
feff2f05 | 5062 | -- No check required if expression is from the expander, we assume the |
5063 | -- expander will generate whatever checks are needed. Note that this is | |
5064 | -- not just an optimization, it avoids infinite recursions! | |
9dfe12ae | 5065 | |
5066 | -- Unchecked conversions must be checked, unless they are initialized | |
5067 | -- scalar values, as in a component assignment in an init proc. | |
5068 | ||
5069 | -- In addition, we force a check if Force_Validity_Checks is set | |
5070 | ||
5071 | elsif not Comes_From_Source (Expr) | |
5072 | and then not Force_Validity_Checks | |
5073 | and then (Nkind (Expr) /= N_Unchecked_Type_Conversion | |
5074 | or else Kill_Range_Check (Expr)) | |
5075 | then | |
5076 | return; | |
5077 | ||
5078 | -- No check required if expression is known to have valid value | |
5079 | ||
5080 | elsif Expr_Known_Valid (Expr) then | |
5081 | return; | |
5082 | ||
feff2f05 | 5083 | -- Ignore case of enumeration with holes where the flag is set not to |
5084 | -- worry about holes, since no special validity check is needed | |
9dfe12ae | 5085 | |
5086 | elsif Is_Enumeration_Type (Typ) | |
5087 | and then Has_Non_Standard_Rep (Typ) | |
5088 | and then Holes_OK | |
5089 | then | |
5090 | return; | |
5091 | ||
f2a06be9 | 5092 | -- No check required on the left-hand side of an assignment |
9dfe12ae | 5093 | |
5094 | elsif Nkind (Parent (Expr)) = N_Assignment_Statement | |
5095 | and then Expr = Name (Parent (Expr)) | |
5096 | then | |
5097 | return; | |
5098 | ||
6fb3c314 | 5099 | -- No check on a universal real constant. The context will eventually |
38f5559f | 5100 | -- convert it to a machine number for some target type, or report an |
5101 | -- illegality. | |
5102 | ||
5103 | elsif Nkind (Expr) = N_Real_Literal | |
5104 | and then Etype (Expr) = Universal_Real | |
5105 | then | |
5106 | return; | |
5107 | ||
6fb3c314 | 5108 | -- If the expression denotes a component of a packed boolean array, |
0577b0b1 | 5109 | -- no possible check applies. We ignore the old ACATS chestnuts that |
5110 | -- involve Boolean range True..True. | |
5111 | ||
5112 | -- Note: validity checks are generated for expressions that yield a | |
5113 | -- scalar type, when it is possible to create a value that is outside of | |
5114 | -- the type. If this is a one-bit boolean no such value exists. This is | |
5115 | -- an optimization, and it also prevents compiler blowing up during the | |
5116 | -- elaboration of improperly expanded packed array references. | |
5117 | ||
5118 | elsif Nkind (Expr) = N_Indexed_Component | |
5119 | and then Is_Bit_Packed_Array (Etype (Prefix (Expr))) | |
5120 | and then Root_Type (Etype (Expr)) = Standard_Boolean | |
5121 | then | |
5122 | return; | |
5123 | ||
737e8460 | 5124 | -- For an expression with actions, we want to insert the validity check |
5125 | -- on the final Expression. | |
5126 | ||
5127 | elsif Nkind (Expr) = N_Expression_With_Actions then | |
5128 | Ensure_Valid (Expression (Expr)); | |
5129 | return; | |
5130 | ||
9dfe12ae | 5131 | -- An annoying special case. If this is an out parameter of a scalar |
5132 | -- type, then the value is not going to be accessed, therefore it is | |
5133 | -- inappropriate to do any validity check at the call site. | |
5134 | ||
5135 | else | |
5136 | -- Only need to worry about scalar types | |
5137 | ||
5138 | if Is_Scalar_Type (Typ) then | |
ee6ba406 | 5139 | declare |
5140 | P : Node_Id; | |
5141 | N : Node_Id; | |
5142 | E : Entity_Id; | |
5143 | F : Entity_Id; | |
5144 | A : Node_Id; | |
5145 | L : List_Id; | |
5146 | ||
5147 | begin | |
5148 | -- Find actual argument (which may be a parameter association) | |
5149 | -- and the parent of the actual argument (the call statement) | |
5150 | ||
5151 | N := Expr; | |
5152 | P := Parent (Expr); | |
5153 | ||
5154 | if Nkind (P) = N_Parameter_Association then | |
5155 | N := P; | |
5156 | P := Parent (N); | |
5157 | end if; | |
5158 | ||
feff2f05 | 5159 | -- Only need to worry if we are argument of a procedure call |
5160 | -- since functions don't have out parameters. If this is an | |
5161 | -- indirect or dispatching call, get signature from the | |
5162 | -- subprogram type. | |
ee6ba406 | 5163 | |
5164 | if Nkind (P) = N_Procedure_Call_Statement then | |
5165 | L := Parameter_Associations (P); | |
9dfe12ae | 5166 | |
5167 | if Is_Entity_Name (Name (P)) then | |
5168 | E := Entity (Name (P)); | |
5169 | else | |
5170 | pragma Assert (Nkind (Name (P)) = N_Explicit_Dereference); | |
5171 | E := Etype (Name (P)); | |
5172 | end if; | |
ee6ba406 | 5173 | |
feff2f05 | 5174 | -- Only need to worry if there are indeed actuals, and if |
5175 | -- this could be a procedure call, otherwise we cannot get a | |
5176 | -- match (either we are not an argument, or the mode of the | |
5177 | -- formal is not OUT). This test also filters out the | |
5178 | -- generic case. | |
ee6ba406 | 5179 | |
20cf157b | 5180 | if Is_Non_Empty_List (L) and then Is_Subprogram (E) then |
5181 | ||
feff2f05 | 5182 | -- This is the loop through parameters, looking for an |
5183 | -- OUT parameter for which we are the argument. | |
ee6ba406 | 5184 | |
5185 | F := First_Formal (E); | |
5186 | A := First (L); | |
ee6ba406 | 5187 | while Present (F) loop |
5188 | if Ekind (F) = E_Out_Parameter and then A = N then | |
5189 | return; | |
5190 | end if; | |
5191 | ||
5192 | Next_Formal (F); | |
5193 | Next (A); | |
5194 | end loop; | |
5195 | end if; | |
5196 | end if; | |
5197 | end; | |
5198 | end if; | |
5199 | end if; | |
5200 | ||
fa6a6949 | 5201 | -- If this is a boolean expression, only its elementary operands need |
90a07d4c | 5202 | -- checking: if they are valid, a boolean or short-circuit operation |
5203 | -- with them will be valid as well. | |
784d4230 | 5204 | |
5205 | if Base_Type (Typ) = Standard_Boolean | |
7af38999 | 5206 | and then |
fa6a6949 | 5207 | (Nkind (Expr) in N_Op or else Nkind (Expr) in N_Short_Circuit) |
784d4230 | 5208 | then |
5209 | return; | |
5210 | end if; | |
5211 | ||
0577b0b1 | 5212 | -- If we fall through, a validity check is required |
ee6ba406 | 5213 | |
5214 | Insert_Valid_Check (Expr); | |
ce7498d3 | 5215 | |
5216 | if Is_Entity_Name (Expr) | |
5217 | and then Safe_To_Capture_Value (Expr, Entity (Expr)) | |
5218 | then | |
5219 | Set_Is_Known_Valid (Entity (Expr)); | |
5220 | end if; | |
ee6ba406 | 5221 | end Ensure_Valid; |
5222 | ||
5223 | ---------------------- | |
5224 | -- Expr_Known_Valid -- | |
5225 | ---------------------- | |
5226 | ||
5227 | function Expr_Known_Valid (Expr : Node_Id) return Boolean is | |
5228 | Typ : constant Entity_Id := Etype (Expr); | |
5229 | ||
5230 | begin | |
feff2f05 | 5231 | -- Non-scalar types are always considered valid, since they never give |
5232 | -- rise to the issues of erroneous or bounded error behavior that are | |
5233 | -- the concern. In formal reference manual terms the notion of validity | |
5234 | -- only applies to scalar types. Note that even when packed arrays are | |
5235 | -- represented using modular types, they are still arrays semantically, | |
5236 | -- so they are also always valid (in particular, the unused bits can be | |
5237 | -- random rubbish without affecting the validity of the array value). | |
ee6ba406 | 5238 | |
fa814356 | 5239 | if not Is_Scalar_Type (Typ) or else Is_Packed_Array_Type (Typ) then |
ee6ba406 | 5240 | return True; |
5241 | ||
5242 | -- If no validity checking, then everything is considered valid | |
5243 | ||
5244 | elsif not Validity_Checks_On then | |
5245 | return True; | |
5246 | ||
5247 | -- Floating-point types are considered valid unless floating-point | |
5248 | -- validity checks have been specifically turned on. | |
5249 | ||
5250 | elsif Is_Floating_Point_Type (Typ) | |
5251 | and then not Validity_Check_Floating_Point | |
5252 | then | |
5253 | return True; | |
5254 | ||
feff2f05 | 5255 | -- If the expression is the value of an object that is known to be |
5256 | -- valid, then clearly the expression value itself is valid. | |
ee6ba406 | 5257 | |
5258 | elsif Is_Entity_Name (Expr) | |
5259 | and then Is_Known_Valid (Entity (Expr)) | |
985fe5d6 | 5260 | |
5261 | -- Exclude volatile variables | |
5262 | ||
5263 | and then not Treat_As_Volatile (Entity (Expr)) | |
ee6ba406 | 5264 | then |
5265 | return True; | |
5266 | ||
0577b0b1 | 5267 | -- References to discriminants are always considered valid. The value |
5268 | -- of a discriminant gets checked when the object is built. Within the | |
5269 | -- record, we consider it valid, and it is important to do so, since | |
5270 | -- otherwise we can try to generate bogus validity checks which | |
feff2f05 | 5271 | -- reference discriminants out of scope. Discriminants of concurrent |
5272 | -- types are excluded for the same reason. | |
0577b0b1 | 5273 | |
5274 | elsif Is_Entity_Name (Expr) | |
feff2f05 | 5275 | and then Denotes_Discriminant (Expr, Check_Concurrent => True) |
0577b0b1 | 5276 | then |
5277 | return True; | |
5278 | ||
feff2f05 | 5279 | -- If the type is one for which all values are known valid, then we are |
5280 | -- sure that the value is valid except in the slightly odd case where | |
5281 | -- the expression is a reference to a variable whose size has been | |
5282 | -- explicitly set to a value greater than the object size. | |
ee6ba406 | 5283 | |
5284 | elsif Is_Known_Valid (Typ) then | |
5285 | if Is_Entity_Name (Expr) | |
5286 | and then Ekind (Entity (Expr)) = E_Variable | |
5287 | and then Esize (Entity (Expr)) > Esize (Typ) | |
5288 | then | |
5289 | return False; | |
5290 | else | |
5291 | return True; | |
5292 | end if; | |
5293 | ||
5294 | -- Integer and character literals always have valid values, where | |
5295 | -- appropriate these will be range checked in any case. | |
5296 | ||
20cf157b | 5297 | elsif Nkind_In (Expr, N_Integer_Literal, N_Character_Literal) then |
ee6ba406 | 5298 | return True; |
5299 | ||
91e47010 | 5300 | -- Real literals are assumed to be valid in VM targets |
5301 | ||
20cf157b | 5302 | elsif VM_Target /= No_VM and then Nkind (Expr) = N_Real_Literal then |
91e47010 | 5303 | return True; |
5304 | ||
ee6ba406 | 5305 | -- If we have a type conversion or a qualification of a known valid |
5306 | -- value, then the result will always be valid. | |
5307 | ||
20cf157b | 5308 | elsif Nkind_In (Expr, N_Type_Conversion, N_Qualified_Expression) then |
ee6ba406 | 5309 | return Expr_Known_Valid (Expression (Expr)); |
5310 | ||
1eb1395f | 5311 | -- Case of expression is a non-floating-point operator. In this case we |
5312 | -- can assume the result is valid the generated code for the operator | |
5313 | -- will include whatever checks are needed (e.g. range checks) to ensure | |
5314 | -- validity. This assumption does not hold for the floating-point case, | |
5315 | -- since floating-point operators can generate Infinite or NaN results | |
5316 | -- which are considered invalid. | |
5317 | ||
5318 | -- Historical note: in older versions, the exemption of floating-point | |
5319 | -- types from this assumption was done only in cases where the parent | |
5320 | -- was an assignment, function call or parameter association. Presumably | |
5321 | -- the idea was that in other contexts, the result would be checked | |
5322 | -- elsewhere, but this list of cases was missing tests (at least the | |
5323 | -- N_Object_Declaration case, as shown by a reported missing validity | |
5324 | -- check), and it is not clear why function calls but not procedure | |
5325 | -- calls were tested for. It really seems more accurate and much | |
5326 | -- safer to recognize that expressions which are the result of a | |
5327 | -- floating-point operator can never be assumed to be valid. | |
5328 | ||
5329 | elsif Nkind (Expr) in N_Op and then not Is_Floating_Point_Type (Typ) then | |
5330 | return True; | |
1d90d657 | 5331 | |
feff2f05 | 5332 | -- The result of a membership test is always valid, since it is true or |
5333 | -- false, there are no other possibilities. | |
0577b0b1 | 5334 | |
5335 | elsif Nkind (Expr) in N_Membership_Test then | |
5336 | return True; | |
5337 | ||
ee6ba406 | 5338 | -- For all other cases, we do not know the expression is valid |
5339 | ||
5340 | else | |
5341 | return False; | |
5342 | end if; | |
5343 | end Expr_Known_Valid; | |
5344 | ||
9dfe12ae | 5345 | ---------------- |
5346 | -- Find_Check -- | |
5347 | ---------------- | |
5348 | ||
5349 | procedure Find_Check | |
5350 | (Expr : Node_Id; | |
5351 | Check_Type : Character; | |
5352 | Target_Type : Entity_Id; | |
5353 | Entry_OK : out Boolean; | |
5354 | Check_Num : out Nat; | |
5355 | Ent : out Entity_Id; | |
5356 | Ofs : out Uint) | |
5357 | is | |
5358 | function Within_Range_Of | |
5359 | (Target_Type : Entity_Id; | |
314a23b6 | 5360 | Check_Type : Entity_Id) return Boolean; |
9dfe12ae | 5361 | -- Given a requirement for checking a range against Target_Type, and |
5362 | -- and a range Check_Type against which a check has already been made, | |
5363 | -- determines if the check against check type is sufficient to ensure | |
5364 | -- that no check against Target_Type is required. | |
5365 | ||
5366 | --------------------- | |
5367 | -- Within_Range_Of -- | |
5368 | --------------------- | |
5369 | ||
5370 | function Within_Range_Of | |
5371 | (Target_Type : Entity_Id; | |
314a23b6 | 5372 | Check_Type : Entity_Id) return Boolean |
9dfe12ae | 5373 | is |
5374 | begin | |
5375 | if Target_Type = Check_Type then | |
5376 | return True; | |
5377 | ||
5378 | else | |
5379 | declare | |
5380 | Tlo : constant Node_Id := Type_Low_Bound (Target_Type); | |
5381 | Thi : constant Node_Id := Type_High_Bound (Target_Type); | |
5382 | Clo : constant Node_Id := Type_Low_Bound (Check_Type); | |
5383 | Chi : constant Node_Id := Type_High_Bound (Check_Type); | |
5384 | ||
5385 | begin | |
5386 | if (Tlo = Clo | |
5387 | or else (Compile_Time_Known_Value (Tlo) | |
5388 | and then | |
5389 | Compile_Time_Known_Value (Clo) | |
5390 | and then | |
5391 | Expr_Value (Clo) >= Expr_Value (Tlo))) | |
5392 | and then | |
5393 | (Thi = Chi | |
5394 | or else (Compile_Time_Known_Value (Thi) | |
5395 | and then | |
5396 | Compile_Time_Known_Value (Chi) | |
5397 | and then | |
5398 | Expr_Value (Chi) <= Expr_Value (Clo))) | |
5399 | then | |
5400 | return True; | |
5401 | else | |
5402 | return False; | |
5403 | end if; | |
5404 | end; | |
5405 | end if; | |
5406 | end Within_Range_Of; | |
5407 | ||
5408 | -- Start of processing for Find_Check | |
5409 | ||
5410 | begin | |
ed195555 | 5411 | -- Establish default, in case no entry is found |
9dfe12ae | 5412 | |
5413 | Check_Num := 0; | |
5414 | ||
5415 | -- Case of expression is simple entity reference | |
5416 | ||
5417 | if Is_Entity_Name (Expr) then | |
5418 | Ent := Entity (Expr); | |
5419 | Ofs := Uint_0; | |
5420 | ||
5421 | -- Case of expression is entity + known constant | |
5422 | ||
5423 | elsif Nkind (Expr) = N_Op_Add | |
5424 | and then Compile_Time_Known_Value (Right_Opnd (Expr)) | |
5425 | and then Is_Entity_Name (Left_Opnd (Expr)) | |
5426 | then | |
5427 | Ent := Entity (Left_Opnd (Expr)); | |
5428 | Ofs := Expr_Value (Right_Opnd (Expr)); | |
5429 | ||
5430 | -- Case of expression is entity - known constant | |
5431 | ||
5432 | elsif Nkind (Expr) = N_Op_Subtract | |
5433 | and then Compile_Time_Known_Value (Right_Opnd (Expr)) | |
5434 | and then Is_Entity_Name (Left_Opnd (Expr)) | |
5435 | then | |
5436 | Ent := Entity (Left_Opnd (Expr)); | |
5437 | Ofs := UI_Negate (Expr_Value (Right_Opnd (Expr))); | |
5438 | ||
5439 | -- Any other expression is not of the right form | |
5440 | ||
5441 | else | |
5442 | Ent := Empty; | |
5443 | Ofs := Uint_0; | |
5444 | Entry_OK := False; | |
5445 | return; | |
5446 | end if; | |
5447 | ||
feff2f05 | 5448 | -- Come here with expression of appropriate form, check if entity is an |
5449 | -- appropriate one for our purposes. | |
9dfe12ae | 5450 | |
5451 | if (Ekind (Ent) = E_Variable | |
cc60bd16 | 5452 | or else Is_Constant_Object (Ent)) |
9dfe12ae | 5453 | and then not Is_Library_Level_Entity (Ent) |
5454 | then | |
5455 | Entry_OK := True; | |
5456 | else | |
5457 | Entry_OK := False; | |
5458 | return; | |
5459 | end if; | |
5460 | ||
5461 | -- See if there is matching check already | |
5462 | ||
5463 | for J in reverse 1 .. Num_Saved_Checks loop | |
5464 | declare | |
5465 | SC : Saved_Check renames Saved_Checks (J); | |
9dfe12ae | 5466 | begin |
5467 | if SC.Killed = False | |
5468 | and then SC.Entity = Ent | |
5469 | and then SC.Offset = Ofs | |
5470 | and then SC.Check_Type = Check_Type | |
5471 | and then Within_Range_Of (Target_Type, SC.Target_Type) | |
5472 | then | |
5473 | Check_Num := J; | |
5474 | return; | |
5475 | end if; | |
5476 | end; | |
5477 | end loop; | |
5478 | ||
5479 | -- If we fall through entry was not found | |
5480 | ||
9dfe12ae | 5481 | return; |
5482 | end Find_Check; | |
5483 | ||
5484 | --------------------------------- | |
5485 | -- Generate_Discriminant_Check -- | |
5486 | --------------------------------- | |
5487 | ||
5488 | -- Note: the code for this procedure is derived from the | |
feff2f05 | 5489 | -- Emit_Discriminant_Check Routine in trans.c. |
9dfe12ae | 5490 | |
5491 | procedure Generate_Discriminant_Check (N : Node_Id) is | |
5492 | Loc : constant Source_Ptr := Sloc (N); | |
5493 | Pref : constant Node_Id := Prefix (N); | |
5494 | Sel : constant Node_Id := Selector_Name (N); | |
5495 | ||
5496 | Orig_Comp : constant Entity_Id := | |
b6341c67 | 5497 | Original_Record_Component (Entity (Sel)); |
9dfe12ae | 5498 | -- The original component to be checked |
5499 | ||
5500 | Discr_Fct : constant Entity_Id := | |
b6341c67 | 5501 | Discriminant_Checking_Func (Orig_Comp); |
9dfe12ae | 5502 | -- The discriminant checking function |
5503 | ||
5504 | Discr : Entity_Id; | |
5505 | -- One discriminant to be checked in the type | |
5506 | ||
5507 | Real_Discr : Entity_Id; | |
5508 | -- Actual discriminant in the call | |
5509 | ||
5510 | Pref_Type : Entity_Id; | |
5511 | -- Type of relevant prefix (ignoring private/access stuff) | |
5512 | ||
5513 | Args : List_Id; | |
5514 | -- List of arguments for function call | |
5515 | ||
5516 | Formal : Entity_Id; | |
feff2f05 | 5517 | -- Keep track of the formal corresponding to the actual we build for |
5518 | -- each discriminant, in order to be able to perform the necessary type | |
5519 | -- conversions. | |
9dfe12ae | 5520 | |
5521 | Scomp : Node_Id; | |
5522 | -- Selected component reference for checking function argument | |
5523 | ||
5524 | begin | |
5525 | Pref_Type := Etype (Pref); | |
5526 | ||
5527 | -- Force evaluation of the prefix, so that it does not get evaluated | |
5528 | -- twice (once for the check, once for the actual reference). Such a | |
20cf157b | 5529 | -- double evaluation is always a potential source of inefficiency, and |
5530 | -- is functionally incorrect in the volatile case, or when the prefix | |
5531 | -- may have side-effects. A non-volatile entity or a component of a | |
5532 | -- non-volatile entity requires no evaluation. | |
9dfe12ae | 5533 | |
5534 | if Is_Entity_Name (Pref) then | |
5535 | if Treat_As_Volatile (Entity (Pref)) then | |
5536 | Force_Evaluation (Pref, Name_Req => True); | |
5537 | end if; | |
5538 | ||
5539 | elsif Treat_As_Volatile (Etype (Pref)) then | |
20cf157b | 5540 | Force_Evaluation (Pref, Name_Req => True); |
9dfe12ae | 5541 | |
5542 | elsif Nkind (Pref) = N_Selected_Component | |
5543 | and then Is_Entity_Name (Prefix (Pref)) | |
5544 | then | |
5545 | null; | |
5546 | ||
5547 | else | |
5548 | Force_Evaluation (Pref, Name_Req => True); | |
5549 | end if; | |
5550 | ||
5551 | -- For a tagged type, use the scope of the original component to | |
5552 | -- obtain the type, because ??? | |
5553 | ||
5554 | if Is_Tagged_Type (Scope (Orig_Comp)) then | |
5555 | Pref_Type := Scope (Orig_Comp); | |
5556 | ||
feff2f05 | 5557 | -- For an untagged derived type, use the discriminants of the parent |
5558 | -- which have been renamed in the derivation, possibly by a one-to-many | |
5559 | -- discriminant constraint. For non-tagged type, initially get the Etype | |
5560 | -- of the prefix | |
9dfe12ae | 5561 | |
5562 | else | |
5563 | if Is_Derived_Type (Pref_Type) | |
5564 | and then Number_Discriminants (Pref_Type) /= | |
5565 | Number_Discriminants (Etype (Base_Type (Pref_Type))) | |
5566 | then | |
5567 | Pref_Type := Etype (Base_Type (Pref_Type)); | |
5568 | end if; | |
5569 | end if; | |
5570 | ||
5571 | -- We definitely should have a checking function, This routine should | |
5572 | -- not be called if no discriminant checking function is present. | |
5573 | ||
5574 | pragma Assert (Present (Discr_Fct)); | |
5575 | ||
5576 | -- Create the list of the actual parameters for the call. This list | |
5577 | -- is the list of the discriminant fields of the record expression to | |
5578 | -- be discriminant checked. | |
5579 | ||
5580 | Args := New_List; | |
5581 | Formal := First_Formal (Discr_Fct); | |
5582 | Discr := First_Discriminant (Pref_Type); | |
5583 | while Present (Discr) loop | |
5584 | ||
5585 | -- If we have a corresponding discriminant field, and a parent | |
5586 | -- subtype is present, then we want to use the corresponding | |
5587 | -- discriminant since this is the one with the useful value. | |
5588 | ||
5589 | if Present (Corresponding_Discriminant (Discr)) | |
5590 | and then Ekind (Pref_Type) = E_Record_Type | |
5591 | and then Present (Parent_Subtype (Pref_Type)) | |
5592 | then | |
5593 | Real_Discr := Corresponding_Discriminant (Discr); | |
5594 | else | |
5595 | Real_Discr := Discr; | |
5596 | end if; | |
5597 | ||
5598 | -- Construct the reference to the discriminant | |
5599 | ||
5600 | Scomp := | |
5601 | Make_Selected_Component (Loc, | |
5602 | Prefix => | |
5603 | Unchecked_Convert_To (Pref_Type, | |
5604 | Duplicate_Subexpr (Pref)), | |
5605 | Selector_Name => New_Occurrence_Of (Real_Discr, Loc)); | |
5606 | ||
5607 | -- Manually analyze and resolve this selected component. We really | |
5608 | -- want it just as it appears above, and do not want the expander | |
feff2f05 | 5609 | -- playing discriminal games etc with this reference. Then we append |
5610 | -- the argument to the list we are gathering. | |
9dfe12ae | 5611 | |
5612 | Set_Etype (Scomp, Etype (Real_Discr)); | |
5613 | Set_Analyzed (Scomp, True); | |
5614 | Append_To (Args, Convert_To (Etype (Formal), Scomp)); | |
5615 | ||
5616 | Next_Formal_With_Extras (Formal); | |
5617 | Next_Discriminant (Discr); | |
5618 | end loop; | |
5619 | ||
5620 | -- Now build and insert the call | |
5621 | ||
5622 | Insert_Action (N, | |
5623 | Make_Raise_Constraint_Error (Loc, | |
5624 | Condition => | |
5625 | Make_Function_Call (Loc, | |
20cf157b | 5626 | Name => New_Occurrence_Of (Discr_Fct, Loc), |
9dfe12ae | 5627 | Parameter_Associations => Args), |
5628 | Reason => CE_Discriminant_Check_Failed)); | |
5629 | end Generate_Discriminant_Check; | |
5630 | ||
5c99c290 | 5631 | --------------------------- |
5632 | -- Generate_Index_Checks -- | |
5633 | --------------------------- | |
9dfe12ae | 5634 | |
5635 | procedure Generate_Index_Checks (N : Node_Id) is | |
05f3e139 | 5636 | |
5637 | function Entity_Of_Prefix return Entity_Id; | |
5638 | -- Returns the entity of the prefix of N (or Empty if not found) | |
5639 | ||
3f42e2a7 | 5640 | ---------------------- |
5641 | -- Entity_Of_Prefix -- | |
5642 | ---------------------- | |
5643 | ||
05f3e139 | 5644 | function Entity_Of_Prefix return Entity_Id is |
e5d38095 | 5645 | P : Node_Id; |
5646 | ||
05f3e139 | 5647 | begin |
e5d38095 | 5648 | P := Prefix (N); |
05f3e139 | 5649 | while not Is_Entity_Name (P) loop |
5650 | if not Nkind_In (P, N_Selected_Component, | |
5651 | N_Indexed_Component) | |
5652 | then | |
5653 | return Empty; | |
5654 | end if; | |
5655 | ||
5656 | P := Prefix (P); | |
5657 | end loop; | |
5658 | ||
5659 | return Entity (P); | |
5660 | end Entity_Of_Prefix; | |
5661 | ||
5662 | -- Local variables | |
5663 | ||
5664 | Loc : constant Source_Ptr := Sloc (N); | |
5665 | A : constant Node_Id := Prefix (N); | |
5666 | A_Ent : constant Entity_Id := Entity_Of_Prefix; | |
5667 | Sub : Node_Id; | |
9dfe12ae | 5668 | |
3f42e2a7 | 5669 | -- Start of processing for Generate_Index_Checks |
5670 | ||
9dfe12ae | 5671 | begin |
05f3e139 | 5672 | -- Ignore call if the prefix is not an array since we have a serious |
5673 | -- error in the sources. Ignore it also if index checks are suppressed | |
5674 | -- for array object or type. | |
0577b0b1 | 5675 | |
05f3e139 | 5676 | if not Is_Array_Type (Etype (A)) |
20cf157b | 5677 | or else (Present (A_Ent) and then Index_Checks_Suppressed (A_Ent)) |
0577b0b1 | 5678 | or else Index_Checks_Suppressed (Etype (A)) |
5679 | then | |
5680 | return; | |
df9fba45 | 5681 | |
5682 | -- The indexed component we are dealing with contains 'Loop_Entry in its | |
5683 | -- prefix. This case arises when analysis has determined that constructs | |
5684 | -- such as | |
5685 | ||
5686 | -- Prefix'Loop_Entry (Expr) | |
5687 | -- Prefix'Loop_Entry (Expr1, Expr2, ... ExprN) | |
5688 | ||
5689 | -- require rewriting for error detection purposes. A side effect of this | |
5690 | -- action is the generation of index checks that mention 'Loop_Entry. | |
5691 | -- Delay the generation of the check until 'Loop_Entry has been properly | |
5692 | -- expanded. This is done in Expand_Loop_Entry_Attributes. | |
5693 | ||
5694 | elsif Nkind (Prefix (N)) = N_Attribute_Reference | |
5695 | and then Attribute_Name (Prefix (N)) = Name_Loop_Entry | |
5696 | then | |
5697 | return; | |
0577b0b1 | 5698 | end if; |
5699 | ||
05f3e139 | 5700 | -- Generate a raise of constraint error with the appropriate reason and |
5701 | -- a condition of the form: | |
5702 | ||
3f42e2a7 | 5703 | -- Base_Type (Sub) not in Array'Range (Subscript) |
05f3e139 | 5704 | |
5705 | -- Note that the reason we generate the conversion to the base type here | |
5706 | -- is that we definitely want the range check to take place, even if it | |
5707 | -- looks like the subtype is OK. Optimization considerations that allow | |
5708 | -- us to omit the check have already been taken into account in the | |
5709 | -- setting of the Do_Range_Check flag earlier on. | |
0577b0b1 | 5710 | |
9dfe12ae | 5711 | Sub := First (Expressions (N)); |
05f3e139 | 5712 | |
5713 | -- Handle string literals | |
5714 | ||
5715 | if Ekind (Etype (A)) = E_String_Literal_Subtype then | |
9dfe12ae | 5716 | if Do_Range_Check (Sub) then |
5717 | Set_Do_Range_Check (Sub, False); | |
5718 | ||
05f3e139 | 5719 | -- For string literals we obtain the bounds of the string from the |
5720 | -- associated subtype. | |
9dfe12ae | 5721 | |
05f3e139 | 5722 | Insert_Action (N, |
094ed68e | 5723 | Make_Raise_Constraint_Error (Loc, |
5724 | Condition => | |
5725 | Make_Not_In (Loc, | |
5726 | Left_Opnd => | |
5727 | Convert_To (Base_Type (Etype (Sub)), | |
5728 | Duplicate_Subexpr_Move_Checks (Sub)), | |
5729 | Right_Opnd => | |
5730 | Make_Attribute_Reference (Loc, | |
5731 | Prefix => New_Reference_To (Etype (A), Loc), | |
5732 | Attribute_Name => Name_Range)), | |
5733 | Reason => CE_Index_Check_Failed)); | |
05f3e139 | 5734 | end if; |
9dfe12ae | 5735 | |
05f3e139 | 5736 | -- General case |
9dfe12ae | 5737 | |
05f3e139 | 5738 | else |
5739 | declare | |
5740 | A_Idx : Node_Id := Empty; | |
5741 | A_Range : Node_Id; | |
5742 | Ind : Nat; | |
5743 | Num : List_Id; | |
5744 | Range_N : Node_Id; | |
9dfe12ae | 5745 | |
05f3e139 | 5746 | begin |
5747 | A_Idx := First_Index (Etype (A)); | |
5748 | Ind := 1; | |
5749 | while Present (Sub) loop | |
5750 | if Do_Range_Check (Sub) then | |
5751 | Set_Do_Range_Check (Sub, False); | |
9dfe12ae | 5752 | |
05f3e139 | 5753 | -- Force evaluation except for the case of a simple name of |
5754 | -- a non-volatile entity. | |
9dfe12ae | 5755 | |
05f3e139 | 5756 | if not Is_Entity_Name (Sub) |
5757 | or else Treat_As_Volatile (Entity (Sub)) | |
5758 | then | |
5759 | Force_Evaluation (Sub); | |
5760 | end if; | |
9dfe12ae | 5761 | |
05f3e139 | 5762 | if Nkind (A_Idx) = N_Range then |
5763 | A_Range := A_Idx; | |
5764 | ||
5765 | elsif Nkind (A_Idx) = N_Identifier | |
5766 | or else Nkind (A_Idx) = N_Expanded_Name | |
5767 | then | |
5768 | A_Range := Scalar_Range (Entity (A_Idx)); | |
5769 | ||
5770 | else pragma Assert (Nkind (A_Idx) = N_Subtype_Indication); | |
5771 | A_Range := Range_Expression (Constraint (A_Idx)); | |
5772 | end if; | |
5773 | ||
5774 | -- For array objects with constant bounds we can generate | |
5775 | -- the index check using the bounds of the type of the index | |
5776 | ||
5777 | if Present (A_Ent) | |
5778 | and then Ekind (A_Ent) = E_Variable | |
5779 | and then Is_Constant_Bound (Low_Bound (A_Range)) | |
5780 | and then Is_Constant_Bound (High_Bound (A_Range)) | |
5781 | then | |
5782 | Range_N := | |
5783 | Make_Attribute_Reference (Loc, | |
3f42e2a7 | 5784 | Prefix => |
5785 | New_Reference_To (Etype (A_Idx), Loc), | |
05f3e139 | 5786 | Attribute_Name => Name_Range); |
5787 | ||
5788 | -- For arrays with non-constant bounds we cannot generate | |
5789 | -- the index check using the bounds of the type of the index | |
5790 | -- since it may reference discriminants of some enclosing | |
5791 | -- type. We obtain the bounds directly from the prefix | |
5792 | -- object. | |
5793 | ||
5794 | else | |
5795 | if Ind = 1 then | |
5796 | Num := No_List; | |
5797 | else | |
5798 | Num := New_List (Make_Integer_Literal (Loc, Ind)); | |
5799 | end if; | |
5800 | ||
5801 | Range_N := | |
5802 | Make_Attribute_Reference (Loc, | |
5803 | Prefix => | |
5804 | Duplicate_Subexpr_Move_Checks (A, Name_Req => True), | |
5805 | Attribute_Name => Name_Range, | |
5806 | Expressions => Num); | |
5807 | end if; | |
5808 | ||
5809 | Insert_Action (N, | |
094ed68e | 5810 | Make_Raise_Constraint_Error (Loc, |
5811 | Condition => | |
5812 | Make_Not_In (Loc, | |
5813 | Left_Opnd => | |
5814 | Convert_To (Base_Type (Etype (Sub)), | |
5815 | Duplicate_Subexpr_Move_Checks (Sub)), | |
5816 | Right_Opnd => Range_N), | |
5817 | Reason => CE_Index_Check_Failed)); | |
05f3e139 | 5818 | end if; |
5819 | ||
5820 | A_Idx := Next_Index (A_Idx); | |
5821 | Ind := Ind + 1; | |
5822 | Next (Sub); | |
5823 | end loop; | |
5824 | end; | |
5825 | end if; | |
9dfe12ae | 5826 | end Generate_Index_Checks; |
5827 | ||
5828 | -------------------------- | |
5829 | -- Generate_Range_Check -- | |
5830 | -------------------------- | |
5831 | ||
5832 | procedure Generate_Range_Check | |
5833 | (N : Node_Id; | |
5834 | Target_Type : Entity_Id; | |
5835 | Reason : RT_Exception_Code) | |
5836 | is | |
5837 | Loc : constant Source_Ptr := Sloc (N); | |
5838 | Source_Type : constant Entity_Id := Etype (N); | |
5839 | Source_Base_Type : constant Entity_Id := Base_Type (Source_Type); | |
5840 | Target_Base_Type : constant Entity_Id := Base_Type (Target_Type); | |
5841 | ||
5842 | begin | |
feff2f05 | 5843 | -- First special case, if the source type is already within the range |
5844 | -- of the target type, then no check is needed (probably we should have | |
5845 | -- stopped Do_Range_Check from being set in the first place, but better | |
b40670e1 | 5846 | -- late than never in preventing junk code! |
9dfe12ae | 5847 | |
7a1dabb3 | 5848 | if In_Subrange_Of (Source_Type, Target_Type) |
b40670e1 | 5849 | |
5850 | -- We do NOT apply this if the source node is a literal, since in this | |
5851 | -- case the literal has already been labeled as having the subtype of | |
5852 | -- the target. | |
5853 | ||
9dfe12ae | 5854 | and then not |
b40670e1 | 5855 | (Nkind_In (N, N_Integer_Literal, N_Real_Literal, N_Character_Literal) |
9dfe12ae | 5856 | or else |
b40670e1 | 5857 | (Is_Entity_Name (N) |
5858 | and then Ekind (Entity (N)) = E_Enumeration_Literal)) | |
5859 | ||
5860 | -- Also do not apply this for floating-point if Check_Float_Overflow | |
5861 | ||
5862 | and then not | |
5863 | (Is_Floating_Point_Type (Source_Type) and Check_Float_Overflow) | |
9dfe12ae | 5864 | then |
5865 | return; | |
5866 | end if; | |
5867 | ||
5868 | -- We need a check, so force evaluation of the node, so that it does | |
5869 | -- not get evaluated twice (once for the check, once for the actual | |
5870 | -- reference). Such a double evaluation is always a potential source | |
5871 | -- of inefficiency, and is functionally incorrect in the volatile case. | |
5872 | ||
b40670e1 | 5873 | if not Is_Entity_Name (N) or else Treat_As_Volatile (Entity (N)) then |
9dfe12ae | 5874 | Force_Evaluation (N); |
5875 | end if; | |
5876 | ||
feff2f05 | 5877 | -- The easiest case is when Source_Base_Type and Target_Base_Type are |
5878 | -- the same since in this case we can simply do a direct check of the | |
5879 | -- value of N against the bounds of Target_Type. | |
9dfe12ae | 5880 | |
5881 | -- [constraint_error when N not in Target_Type] | |
5882 | ||
5883 | -- Note: this is by far the most common case, for example all cases of | |
5884 | -- checks on the RHS of assignments are in this category, but not all | |
5885 | -- cases are like this. Notably conversions can involve two types. | |
5886 | ||
5887 | if Source_Base_Type = Target_Base_Type then | |
5888 | Insert_Action (N, | |
5889 | Make_Raise_Constraint_Error (Loc, | |
5890 | Condition => | |
5891 | Make_Not_In (Loc, | |
5892 | Left_Opnd => Duplicate_Subexpr (N), | |
5893 | Right_Opnd => New_Occurrence_Of (Target_Type, Loc)), | |
5894 | Reason => Reason)); | |
5895 | ||
5896 | -- Next test for the case where the target type is within the bounds | |
5897 | -- of the base type of the source type, since in this case we can | |
5898 | -- simply convert these bounds to the base type of T to do the test. | |
5899 | ||
5900 | -- [constraint_error when N not in | |
5901 | -- Source_Base_Type (Target_Type'First) | |
5902 | -- .. | |
5903 | -- Source_Base_Type(Target_Type'Last))] | |
5904 | ||
f2a06be9 | 5905 | -- The conversions will always work and need no check |
9dfe12ae | 5906 | |
a9b57347 | 5907 | -- Unchecked_Convert_To is used instead of Convert_To to handle the case |
5908 | -- of converting from an enumeration value to an integer type, such as | |
5909 | -- occurs for the case of generating a range check on Enum'Val(Exp) | |
5910 | -- (which used to be handled by gigi). This is OK, since the conversion | |
5911 | -- itself does not require a check. | |
5912 | ||
7a1dabb3 | 5913 | elsif In_Subrange_Of (Target_Type, Source_Base_Type) then |
9dfe12ae | 5914 | Insert_Action (N, |
5915 | Make_Raise_Constraint_Error (Loc, | |
5916 | Condition => | |
5917 | Make_Not_In (Loc, | |
5918 | Left_Opnd => Duplicate_Subexpr (N), | |
5919 | ||
5920 | Right_Opnd => | |
5921 | Make_Range (Loc, | |
5922 | Low_Bound => | |
a9b57347 | 5923 | Unchecked_Convert_To (Source_Base_Type, |
9dfe12ae | 5924 | Make_Attribute_Reference (Loc, |
5925 | Prefix => | |
5926 | New_Occurrence_Of (Target_Type, Loc), | |
5927 | Attribute_Name => Name_First)), | |
5928 | ||
5929 | High_Bound => | |
a9b57347 | 5930 | Unchecked_Convert_To (Source_Base_Type, |
9dfe12ae | 5931 | Make_Attribute_Reference (Loc, |
5932 | Prefix => | |
5933 | New_Occurrence_Of (Target_Type, Loc), | |
5934 | Attribute_Name => Name_Last)))), | |
5935 | Reason => Reason)); | |
5936 | ||
feff2f05 | 5937 | -- Note that at this stage we now that the Target_Base_Type is not in |
5938 | -- the range of the Source_Base_Type (since even the Target_Type itself | |
5939 | -- is not in this range). It could still be the case that Source_Type is | |
5940 | -- in range of the target base type since we have not checked that case. | |
9dfe12ae | 5941 | |
feff2f05 | 5942 | -- If that is the case, we can freely convert the source to the target, |
5943 | -- and then test the target result against the bounds. | |
9dfe12ae | 5944 | |
7a1dabb3 | 5945 | elsif In_Subrange_Of (Source_Type, Target_Base_Type) then |
9dfe12ae | 5946 | |
feff2f05 | 5947 | -- We make a temporary to hold the value of the converted value |
5948 | -- (converted to the base type), and then we will do the test against | |
5949 | -- this temporary. | |
9dfe12ae | 5950 | |
5951 | -- Tnn : constant Target_Base_Type := Target_Base_Type (N); | |
5952 | -- [constraint_error when Tnn not in Target_Type] | |
5953 | ||
5954 | -- Then the conversion itself is replaced by an occurrence of Tnn | |
5955 | ||
5956 | declare | |
46eb6933 | 5957 | Tnn : constant Entity_Id := Make_Temporary (Loc, 'T', N); |
9dfe12ae | 5958 | |
5959 | begin | |
5960 | Insert_Actions (N, New_List ( | |
5961 | Make_Object_Declaration (Loc, | |
5962 | Defining_Identifier => Tnn, | |
5963 | Object_Definition => | |
5964 | New_Occurrence_Of (Target_Base_Type, Loc), | |
5965 | Constant_Present => True, | |
5966 | Expression => | |
5967 | Make_Type_Conversion (Loc, | |
5968 | Subtype_Mark => New_Occurrence_Of (Target_Base_Type, Loc), | |
5969 | Expression => Duplicate_Subexpr (N))), | |
5970 | ||
5971 | Make_Raise_Constraint_Error (Loc, | |
5972 | Condition => | |
5973 | Make_Not_In (Loc, | |
5974 | Left_Opnd => New_Occurrence_Of (Tnn, Loc), | |
5975 | Right_Opnd => New_Occurrence_Of (Target_Type, Loc)), | |
5976 | ||
5977 | Reason => Reason))); | |
5978 | ||
5979 | Rewrite (N, New_Occurrence_Of (Tnn, Loc)); | |
2af58f67 | 5980 | |
5981 | -- Set the type of N, because the declaration for Tnn might not | |
5982 | -- be analyzed yet, as is the case if N appears within a record | |
5983 | -- declaration, as a discriminant constraint or expression. | |
5984 | ||
5985 | Set_Etype (N, Target_Base_Type); | |
9dfe12ae | 5986 | end; |
5987 | ||
5988 | -- At this stage, we know that we have two scalar types, which are | |
5989 | -- directly convertible, and where neither scalar type has a base | |
5990 | -- range that is in the range of the other scalar type. | |
5991 | ||
5992 | -- The only way this can happen is with a signed and unsigned type. | |
5993 | -- So test for these two cases: | |
5994 | ||
5995 | else | |
5996 | -- Case of the source is unsigned and the target is signed | |
5997 | ||
5998 | if Is_Unsigned_Type (Source_Base_Type) | |
5999 | and then not Is_Unsigned_Type (Target_Base_Type) | |
6000 | then | |
6001 | -- If the source is unsigned and the target is signed, then we | |
6002 | -- know that the source is not shorter than the target (otherwise | |
6003 | -- the source base type would be in the target base type range). | |
6004 | ||
feff2f05 | 6005 | -- In other words, the unsigned type is either the same size as |
6006 | -- the target, or it is larger. It cannot be smaller. | |
9dfe12ae | 6007 | |
6008 | pragma Assert | |
6009 | (Esize (Source_Base_Type) >= Esize (Target_Base_Type)); | |
6010 | ||
6011 | -- We only need to check the low bound if the low bound of the | |
6012 | -- target type is non-negative. If the low bound of the target | |
6013 | -- type is negative, then we know that we will fit fine. | |
6014 | ||
6015 | -- If the high bound of the target type is negative, then we | |
6016 | -- know we have a constraint error, since we can't possibly | |
6017 | -- have a negative source. | |
6018 | ||
6019 | -- With these two checks out of the way, we can do the check | |
6020 | -- using the source type safely | |
6021 | ||
6022 | -- This is definitely the most annoying case! | |
6023 | ||
6024 | -- [constraint_error | |
6025 | -- when (Target_Type'First >= 0 | |
6026 | -- and then | |
6027 | -- N < Source_Base_Type (Target_Type'First)) | |
6028 | -- or else Target_Type'Last < 0 | |
6029 | -- or else N > Source_Base_Type (Target_Type'Last)]; | |
6030 | ||
6031 | -- We turn off all checks since we know that the conversions | |
6032 | -- will work fine, given the guards for negative values. | |
6033 | ||
6034 | Insert_Action (N, | |
6035 | Make_Raise_Constraint_Error (Loc, | |
6036 | Condition => | |
6037 | Make_Or_Else (Loc, | |
6038 | Make_Or_Else (Loc, | |
6039 | Left_Opnd => | |
6040 | Make_And_Then (Loc, | |
6041 | Left_Opnd => Make_Op_Ge (Loc, | |
6042 | Left_Opnd => | |
6043 | Make_Attribute_Reference (Loc, | |
6044 | Prefix => | |
6045 | New_Occurrence_Of (Target_Type, Loc), | |
6046 | Attribute_Name => Name_First), | |
6047 | Right_Opnd => Make_Integer_Literal (Loc, Uint_0)), | |
6048 | ||
6049 | Right_Opnd => | |
6050 | Make_Op_Lt (Loc, | |
6051 | Left_Opnd => Duplicate_Subexpr (N), | |
6052 | Right_Opnd => | |
6053 | Convert_To (Source_Base_Type, | |
6054 | Make_Attribute_Reference (Loc, | |
6055 | Prefix => | |
6056 | New_Occurrence_Of (Target_Type, Loc), | |
6057 | Attribute_Name => Name_First)))), | |
6058 | ||
6059 | Right_Opnd => | |
6060 | Make_Op_Lt (Loc, | |
6061 | Left_Opnd => | |
6062 | Make_Attribute_Reference (Loc, | |
6063 | Prefix => New_Occurrence_Of (Target_Type, Loc), | |
6064 | Attribute_Name => Name_Last), | |
6065 | Right_Opnd => Make_Integer_Literal (Loc, Uint_0))), | |
6066 | ||
6067 | Right_Opnd => | |
6068 | Make_Op_Gt (Loc, | |
6069 | Left_Opnd => Duplicate_Subexpr (N), | |
6070 | Right_Opnd => | |
6071 | Convert_To (Source_Base_Type, | |
6072 | Make_Attribute_Reference (Loc, | |
6073 | Prefix => New_Occurrence_Of (Target_Type, Loc), | |
6074 | Attribute_Name => Name_Last)))), | |
6075 | ||
6076 | Reason => Reason), | |
6077 | Suppress => All_Checks); | |
6078 | ||
6079 | -- Only remaining possibility is that the source is signed and | |
fc75802a | 6080 | -- the target is unsigned. |
9dfe12ae | 6081 | |
6082 | else | |
6083 | pragma Assert (not Is_Unsigned_Type (Source_Base_Type) | |
20cf157b | 6084 | and then Is_Unsigned_Type (Target_Base_Type)); |
9dfe12ae | 6085 | |
feff2f05 | 6086 | -- If the source is signed and the target is unsigned, then we |
6087 | -- know that the target is not shorter than the source (otherwise | |
6088 | -- the target base type would be in the source base type range). | |
9dfe12ae | 6089 | |
feff2f05 | 6090 | -- In other words, the unsigned type is either the same size as |
6091 | -- the target, or it is larger. It cannot be smaller. | |
9dfe12ae | 6092 | |
feff2f05 | 6093 | -- Clearly we have an error if the source value is negative since |
6094 | -- no unsigned type can have negative values. If the source type | |
6095 | -- is non-negative, then the check can be done using the target | |
6096 | -- type. | |
9dfe12ae | 6097 | |
6098 | -- Tnn : constant Target_Base_Type (N) := Target_Type; | |
6099 | ||
6100 | -- [constraint_error | |
6101 | -- when N < 0 or else Tnn not in Target_Type]; | |
6102 | ||
feff2f05 | 6103 | -- We turn off all checks for the conversion of N to the target |
6104 | -- base type, since we generate the explicit check to ensure that | |
6105 | -- the value is non-negative | |
9dfe12ae | 6106 | |
6107 | declare | |
46eb6933 | 6108 | Tnn : constant Entity_Id := Make_Temporary (Loc, 'T', N); |
9dfe12ae | 6109 | |
6110 | begin | |
6111 | Insert_Actions (N, New_List ( | |
6112 | Make_Object_Declaration (Loc, | |
6113 | Defining_Identifier => Tnn, | |
6114 | Object_Definition => | |
6115 | New_Occurrence_Of (Target_Base_Type, Loc), | |
6116 | Constant_Present => True, | |
6117 | Expression => | |
a9b57347 | 6118 | Make_Unchecked_Type_Conversion (Loc, |
9dfe12ae | 6119 | Subtype_Mark => |
6120 | New_Occurrence_Of (Target_Base_Type, Loc), | |
6121 | Expression => Duplicate_Subexpr (N))), | |
6122 | ||
6123 | Make_Raise_Constraint_Error (Loc, | |
6124 | Condition => | |
6125 | Make_Or_Else (Loc, | |
6126 | Left_Opnd => | |
6127 | Make_Op_Lt (Loc, | |
6128 | Left_Opnd => Duplicate_Subexpr (N), | |
6129 | Right_Opnd => Make_Integer_Literal (Loc, Uint_0)), | |
6130 | ||
6131 | Right_Opnd => | |
6132 | Make_Not_In (Loc, | |
6133 | Left_Opnd => New_Occurrence_Of (Tnn, Loc), | |
6134 | Right_Opnd => | |
6135 | New_Occurrence_Of (Target_Type, Loc))), | |
6136 | ||
20cf157b | 6137 | Reason => Reason)), |
9dfe12ae | 6138 | Suppress => All_Checks); |
6139 | ||
feff2f05 | 6140 | -- Set the Etype explicitly, because Insert_Actions may have |
6141 | -- placed the declaration in the freeze list for an enclosing | |
6142 | -- construct, and thus it is not analyzed yet. | |
9dfe12ae | 6143 | |
6144 | Set_Etype (Tnn, Target_Base_Type); | |
6145 | Rewrite (N, New_Occurrence_Of (Tnn, Loc)); | |
6146 | end; | |
6147 | end if; | |
6148 | end if; | |
6149 | end Generate_Range_Check; | |
6150 | ||
2af58f67 | 6151 | ------------------ |
6152 | -- Get_Check_Id -- | |
6153 | ------------------ | |
6154 | ||
6155 | function Get_Check_Id (N : Name_Id) return Check_Id is | |
6156 | begin | |
6157 | -- For standard check name, we can do a direct computation | |
6158 | ||
6159 | if N in First_Check_Name .. Last_Check_Name then | |
6160 | return Check_Id (N - (First_Check_Name - 1)); | |
6161 | ||
6162 | -- For non-standard names added by pragma Check_Name, search table | |
6163 | ||
6164 | else | |
6165 | for J in All_Checks + 1 .. Check_Names.Last loop | |
6166 | if Check_Names.Table (J) = N then | |
6167 | return J; | |
6168 | end if; | |
6169 | end loop; | |
6170 | end if; | |
6171 | ||
6172 | -- No matching name found | |
6173 | ||
6174 | return No_Check_Id; | |
6175 | end Get_Check_Id; | |
6176 | ||
ee6ba406 | 6177 | --------------------- |
6178 | -- Get_Discriminal -- | |
6179 | --------------------- | |
6180 | ||
6181 | function Get_Discriminal (E : Entity_Id; Bound : Node_Id) return Node_Id is | |
6182 | Loc : constant Source_Ptr := Sloc (E); | |
6183 | D : Entity_Id; | |
6184 | Sc : Entity_Id; | |
6185 | ||
6186 | begin | |
0577b0b1 | 6187 | -- The bound can be a bona fide parameter of a protected operation, |
6188 | -- rather than a prival encoded as an in-parameter. | |
6189 | ||
6190 | if No (Discriminal_Link (Entity (Bound))) then | |
6191 | return Bound; | |
6192 | end if; | |
6193 | ||
2af58f67 | 6194 | -- Climb the scope stack looking for an enclosing protected type. If |
6195 | -- we run out of scopes, return the bound itself. | |
6196 | ||
6197 | Sc := Scope (E); | |
6198 | while Present (Sc) loop | |
6199 | if Sc = Standard_Standard then | |
6200 | return Bound; | |
2af58f67 | 6201 | elsif Ekind (Sc) = E_Protected_Type then |
6202 | exit; | |
6203 | end if; | |
6204 | ||
6205 | Sc := Scope (Sc); | |
6206 | end loop; | |
6207 | ||
ee6ba406 | 6208 | D := First_Discriminant (Sc); |
2af58f67 | 6209 | while Present (D) loop |
6210 | if Chars (D) = Chars (Bound) then | |
6211 | return New_Occurrence_Of (Discriminal (D), Loc); | |
6212 | end if; | |
ee6ba406 | 6213 | |
ee6ba406 | 6214 | Next_Discriminant (D); |
6215 | end loop; | |
6216 | ||
2af58f67 | 6217 | return Bound; |
ee6ba406 | 6218 | end Get_Discriminal; |
6219 | ||
2af58f67 | 6220 | ---------------------- |
6221 | -- Get_Range_Checks -- | |
6222 | ---------------------- | |
6223 | ||
6224 | function Get_Range_Checks | |
6225 | (Ck_Node : Node_Id; | |
6226 | Target_Typ : Entity_Id; | |
6227 | Source_Typ : Entity_Id := Empty; | |
6228 | Warn_Node : Node_Id := Empty) return Check_Result | |
6229 | is | |
6230 | begin | |
20cf157b | 6231 | return |
6232 | Selected_Range_Checks (Ck_Node, Target_Typ, Source_Typ, Warn_Node); | |
2af58f67 | 6233 | end Get_Range_Checks; |
6234 | ||
ee6ba406 | 6235 | ------------------ |
6236 | -- Guard_Access -- | |
6237 | ------------------ | |
6238 | ||
6239 | function Guard_Access | |
6240 | (Cond : Node_Id; | |
6241 | Loc : Source_Ptr; | |
314a23b6 | 6242 | Ck_Node : Node_Id) return Node_Id |
ee6ba406 | 6243 | is |
6244 | begin | |
6245 | if Nkind (Cond) = N_Or_Else then | |
6246 | Set_Paren_Count (Cond, 1); | |
6247 | end if; | |
6248 | ||
6249 | if Nkind (Ck_Node) = N_Allocator then | |
6250 | return Cond; | |
20cf157b | 6251 | |
ee6ba406 | 6252 | else |
6253 | return | |
6254 | Make_And_Then (Loc, | |
6255 | Left_Opnd => | |
6256 | Make_Op_Ne (Loc, | |
9dfe12ae | 6257 | Left_Opnd => Duplicate_Subexpr_No_Checks (Ck_Node), |
ee6ba406 | 6258 | Right_Opnd => Make_Null (Loc)), |
6259 | Right_Opnd => Cond); | |
6260 | end if; | |
6261 | end Guard_Access; | |
6262 | ||
6263 | ----------------------------- | |
6264 | -- Index_Checks_Suppressed -- | |
6265 | ----------------------------- | |
6266 | ||
6267 | function Index_Checks_Suppressed (E : Entity_Id) return Boolean is | |
6268 | begin | |
9dfe12ae | 6269 | if Present (E) and then Checks_May_Be_Suppressed (E) then |
6270 | return Is_Check_Suppressed (E, Index_Check); | |
6271 | else | |
fafc6b97 | 6272 | return Scope_Suppress.Suppress (Index_Check); |
9dfe12ae | 6273 | end if; |
ee6ba406 | 6274 | end Index_Checks_Suppressed; |
6275 | ||
6276 | ---------------- | |
6277 | -- Initialize -- | |
6278 | ---------------- | |
6279 | ||
6280 | procedure Initialize is | |
6281 | begin | |
6282 | for J in Determine_Range_Cache_N'Range loop | |
6283 | Determine_Range_Cache_N (J) := Empty; | |
6284 | end loop; | |
2af58f67 | 6285 | |
6286 | Check_Names.Init; | |
6287 | ||
6288 | for J in Int range 1 .. All_Checks loop | |
6289 | Check_Names.Append (Name_Id (Int (First_Check_Name) + J - 1)); | |
6290 | end loop; | |
ee6ba406 | 6291 | end Initialize; |
6292 | ||
6293 | ------------------------- | |
6294 | -- Insert_Range_Checks -- | |
6295 | ------------------------- | |
6296 | ||
6297 | procedure Insert_Range_Checks | |
6298 | (Checks : Check_Result; | |
6299 | Node : Node_Id; | |
6300 | Suppress_Typ : Entity_Id; | |
6301 | Static_Sloc : Source_Ptr := No_Location; | |
6302 | Flag_Node : Node_Id := Empty; | |
6303 | Do_Before : Boolean := False) | |
6304 | is | |
6305 | Internal_Flag_Node : Node_Id := Flag_Node; | |
6306 | Internal_Static_Sloc : Source_Ptr := Static_Sloc; | |
6307 | ||
6308 | Check_Node : Node_Id; | |
6309 | Checks_On : constant Boolean := | |
b6341c67 | 6310 | (not Index_Checks_Suppressed (Suppress_Typ)) |
6311 | or else (not Range_Checks_Suppressed (Suppress_Typ)); | |
ee6ba406 | 6312 | |
6313 | begin | |
feff2f05 | 6314 | -- For now we just return if Checks_On is false, however this should be |
6315 | -- enhanced to check for an always True value in the condition and to | |
6316 | -- generate a compilation warning??? | |
ee6ba406 | 6317 | |
ac9184ed | 6318 | if not Expander_Active or not Checks_On then |
ee6ba406 | 6319 | return; |
6320 | end if; | |
6321 | ||
6322 | if Static_Sloc = No_Location then | |
6323 | Internal_Static_Sloc := Sloc (Node); | |
6324 | end if; | |
6325 | ||
6326 | if No (Flag_Node) then | |
6327 | Internal_Flag_Node := Node; | |
6328 | end if; | |
6329 | ||
6330 | for J in 1 .. 2 loop | |
6331 | exit when No (Checks (J)); | |
6332 | ||
6333 | if Nkind (Checks (J)) = N_Raise_Constraint_Error | |
6334 | and then Present (Condition (Checks (J))) | |
6335 | then | |
6336 | if not Has_Dynamic_Range_Check (Internal_Flag_Node) then | |
6337 | Check_Node := Checks (J); | |
6338 | Mark_Rewrite_Insertion (Check_Node); | |
6339 | ||
6340 | if Do_Before then | |
6341 | Insert_Before_And_Analyze (Node, Check_Node); | |
6342 | else | |
6343 | Insert_After_And_Analyze (Node, Check_Node); | |
6344 | end if; | |
6345 | ||
6346 | Set_Has_Dynamic_Range_Check (Internal_Flag_Node); | |
6347 | end if; | |
6348 | ||
6349 | else | |
6350 | Check_Node := | |
f15731c4 | 6351 | Make_Raise_Constraint_Error (Internal_Static_Sloc, |
6352 | Reason => CE_Range_Check_Failed); | |
ee6ba406 | 6353 | Mark_Rewrite_Insertion (Check_Node); |
6354 | ||
6355 | if Do_Before then | |
6356 | Insert_Before_And_Analyze (Node, Check_Node); | |
6357 | else | |
6358 | Insert_After_And_Analyze (Node, Check_Node); | |
6359 | end if; | |
6360 | end if; | |
6361 | end loop; | |
6362 | end Insert_Range_Checks; | |
6363 | ||
6364 | ------------------------ | |
6365 | -- Insert_Valid_Check -- | |
6366 | ------------------------ | |
6367 | ||
6368 | procedure Insert_Valid_Check (Expr : Node_Id) is | |
6369 | Loc : constant Source_Ptr := Sloc (Expr); | |
70580828 | 6370 | Typ : constant Entity_Id := Etype (Expr); |
8b718dab | 6371 | Exp : Node_Id; |
ee6ba406 | 6372 | |
6373 | begin | |
06ad5813 | 6374 | -- Do not insert if checks off, or if not checking validity or |
6375 | -- if expression is known to be valid | |
ee6ba406 | 6376 | |
0577b0b1 | 6377 | if not Validity_Checks_On |
6378 | or else Range_Or_Validity_Checks_Suppressed (Expr) | |
06ad5813 | 6379 | or else Expr_Known_Valid (Expr) |
ee6ba406 | 6380 | then |
8b718dab | 6381 | return; |
6382 | end if; | |
ee6ba406 | 6383 | |
42c57d55 | 6384 | -- Do not insert checks within a predicate function. This will arise |
6385 | -- if the current unit and the predicate function are being compiled | |
6386 | -- with validity checks enabled. | |
70580828 | 6387 | |
6388 | if Present (Predicate_Function (Typ)) | |
6389 | and then Current_Scope = Predicate_Function (Typ) | |
6390 | then | |
6391 | return; | |
6392 | end if; | |
6393 | ||
8b718dab | 6394 | -- If we have a checked conversion, then validity check applies to |
6395 | -- the expression inside the conversion, not the result, since if | |
6396 | -- the expression inside is valid, then so is the conversion result. | |
ee6ba406 | 6397 | |
8b718dab | 6398 | Exp := Expr; |
6399 | while Nkind (Exp) = N_Type_Conversion loop | |
6400 | Exp := Expression (Exp); | |
6401 | end loop; | |
6402 | ||
0577b0b1 | 6403 | -- We are about to insert the validity check for Exp. We save and |
6404 | -- reset the Do_Range_Check flag over this validity check, and then | |
6405 | -- put it back for the final original reference (Exp may be rewritten). | |
6406 | ||
6407 | declare | |
6408 | DRC : constant Boolean := Do_Range_Check (Exp); | |
23abd64d | 6409 | PV : Node_Id; |
6410 | CE : Node_Id; | |
05fcfafb | 6411 | |
0577b0b1 | 6412 | begin |
6413 | Set_Do_Range_Check (Exp, False); | |
6414 | ||
06ad5813 | 6415 | -- Force evaluation to avoid multiple reads for atomic/volatile |
6416 | ||
6417 | if Is_Entity_Name (Exp) | |
6418 | and then Is_Volatile (Entity (Exp)) | |
6419 | then | |
6420 | Force_Evaluation (Exp, Name_Req => True); | |
6421 | end if; | |
6422 | ||
23abd64d | 6423 | -- Build the prefix for the 'Valid call |
6424 | ||
6425 | PV := Duplicate_Subexpr_No_Checks (Exp, Name_Req => True); | |
0577b0b1 | 6426 | |
23abd64d | 6427 | -- A rather specialized kludge. If PV is an analyzed expression |
6428 | -- which is an indexed component of a packed array that has not | |
6429 | -- been properly expanded, turn off its Analyzed flag to make sure | |
6430 | -- it gets properly reexpanded. | |
6431 | ||
6432 | -- The reason this arises is that Duplicate_Subexpr_No_Checks did | |
6433 | -- an analyze with the old parent pointer. This may point e.g. to | |
6434 | -- a subprogram call, which deactivates this expansion. | |
6435 | ||
6436 | if Analyzed (PV) | |
6437 | and then Nkind (PV) = N_Indexed_Component | |
6438 | and then Present (Packed_Array_Type (Etype (Prefix (PV)))) | |
6439 | then | |
6440 | Set_Analyzed (PV, False); | |
6441 | end if; | |
6442 | ||
6443 | -- Build the raise CE node to check for validity | |
6444 | ||
6445 | CE := | |
0577b0b1 | 6446 | Make_Raise_Constraint_Error (Loc, |
6447 | Condition => | |
6448 | Make_Op_Not (Loc, | |
6449 | Right_Opnd => | |
6450 | Make_Attribute_Reference (Loc, | |
23abd64d | 6451 | Prefix => PV, |
0577b0b1 | 6452 | Attribute_Name => Name_Valid)), |
23abd64d | 6453 | Reason => CE_Invalid_Data); |
6454 | ||
6455 | -- Insert the validity check. Note that we do this with validity | |
6456 | -- checks turned off, to avoid recursion, we do not want validity | |
6457 | -- checks on the validity checking code itself! | |
6458 | ||
6459 | Insert_Action (Expr, CE, Suppress => Validity_Check); | |
0577b0b1 | 6460 | |
6fb3c314 | 6461 | -- If the expression is a reference to an element of a bit-packed |
0577b0b1 | 6462 | -- array, then it is rewritten as a renaming declaration. If the |
6463 | -- expression is an actual in a call, it has not been expanded, | |
6464 | -- waiting for the proper point at which to do it. The same happens | |
6465 | -- with renamings, so that we have to force the expansion now. This | |
6466 | -- non-local complication is due to code in exp_ch2,adb, exp_ch4.adb | |
6467 | -- and exp_ch6.adb. | |
6468 | ||
6469 | if Is_Entity_Name (Exp) | |
6470 | and then Nkind (Parent (Entity (Exp))) = | |
20cf157b | 6471 | N_Object_Renaming_Declaration |
0577b0b1 | 6472 | then |
6473 | declare | |
6474 | Old_Exp : constant Node_Id := Name (Parent (Entity (Exp))); | |
6475 | begin | |
6476 | if Nkind (Old_Exp) = N_Indexed_Component | |
6477 | and then Is_Bit_Packed_Array (Etype (Prefix (Old_Exp))) | |
6478 | then | |
6479 | Expand_Packed_Element_Reference (Old_Exp); | |
6480 | end if; | |
6481 | end; | |
6482 | end if; | |
6483 | ||
6484 | -- Put back the Do_Range_Check flag on the resulting (possibly | |
6485 | -- rewritten) expression. | |
6486 | ||
6487 | -- Note: it might be thought that a validity check is not required | |
6488 | -- when a range check is present, but that's not the case, because | |
6489 | -- the back end is allowed to assume for the range check that the | |
6490 | -- operand is within its declared range (an assumption that validity | |
6491 | -- checking is all about NOT assuming!) | |
6492 | ||
00c403ee | 6493 | -- Note: no need to worry about Possible_Local_Raise here, it will |
6494 | -- already have been called if original node has Do_Range_Check set. | |
6495 | ||
0577b0b1 | 6496 | Set_Do_Range_Check (Exp, DRC); |
6497 | end; | |
ee6ba406 | 6498 | end Insert_Valid_Check; |
6499 | ||
3cce7f32 | 6500 | ------------------------------------- |
6501 | -- Is_Signed_Integer_Arithmetic_Op -- | |
6502 | ------------------------------------- | |
6503 | ||
6504 | function Is_Signed_Integer_Arithmetic_Op (N : Node_Id) return Boolean is | |
6505 | begin | |
6506 | case Nkind (N) is | |
6507 | when N_Op_Abs | N_Op_Add | N_Op_Divide | N_Op_Expon | | |
6508 | N_Op_Minus | N_Op_Mod | N_Op_Multiply | N_Op_Plus | | |
6509 | N_Op_Rem | N_Op_Subtract => | |
6510 | return Is_Signed_Integer_Type (Etype (N)); | |
6511 | ||
92f1631f | 6512 | when N_If_Expression | N_Case_Expression => |
0326b4d4 | 6513 | return Is_Signed_Integer_Type (Etype (N)); |
6514 | ||
3cce7f32 | 6515 | when others => |
6516 | return False; | |
6517 | end case; | |
6518 | end Is_Signed_Integer_Arithmetic_Op; | |
6519 | ||
fa7497e8 | 6520 | ---------------------------------- |
6521 | -- Install_Null_Excluding_Check -- | |
6522 | ---------------------------------- | |
6523 | ||
6524 | procedure Install_Null_Excluding_Check (N : Node_Id) is | |
9f294c82 | 6525 | Loc : constant Source_Ptr := Sloc (Parent (N)); |
84d0d4a5 | 6526 | Typ : constant Entity_Id := Etype (N); |
6527 | ||
7b31b357 | 6528 | function Safe_To_Capture_In_Parameter_Value return Boolean; |
6529 | -- Determines if it is safe to capture Known_Non_Null status for an | |
6530 | -- the entity referenced by node N. The caller ensures that N is indeed | |
6531 | -- an entity name. It is safe to capture the non-null status for an IN | |
6532 | -- parameter when the reference occurs within a declaration that is sure | |
6533 | -- to be executed as part of the declarative region. | |
7870823d | 6534 | |
84d0d4a5 | 6535 | procedure Mark_Non_Null; |
7870823d | 6536 | -- After installation of check, if the node in question is an entity |
6537 | -- name, then mark this entity as non-null if possible. | |
6538 | ||
7b31b357 | 6539 | function Safe_To_Capture_In_Parameter_Value return Boolean is |
7870823d | 6540 | E : constant Entity_Id := Entity (N); |
6541 | S : constant Entity_Id := Current_Scope; | |
6542 | S_Par : Node_Id; | |
6543 | ||
6544 | begin | |
7b31b357 | 6545 | if Ekind (E) /= E_In_Parameter then |
6546 | return False; | |
6547 | end if; | |
7870823d | 6548 | |
6549 | -- Two initial context checks. We must be inside a subprogram body | |
6550 | -- with declarations and reference must not appear in nested scopes. | |
6551 | ||
7b31b357 | 6552 | if (Ekind (S) /= E_Function and then Ekind (S) /= E_Procedure) |
7870823d | 6553 | or else Scope (E) /= S |
6554 | then | |
6555 | return False; | |
6556 | end if; | |
6557 | ||
6558 | S_Par := Parent (Parent (S)); | |
6559 | ||
6560 | if Nkind (S_Par) /= N_Subprogram_Body | |
6561 | or else No (Declarations (S_Par)) | |
6562 | then | |
6563 | return False; | |
6564 | end if; | |
6565 | ||
6566 | declare | |
6567 | N_Decl : Node_Id; | |
6568 | P : Node_Id; | |
6569 | ||
6570 | begin | |
6571 | -- Retrieve the declaration node of N (if any). Note that N | |
6572 | -- may be a part of a complex initialization expression. | |
6573 | ||
6574 | P := Parent (N); | |
6575 | N_Decl := Empty; | |
6576 | while Present (P) loop | |
6577 | ||
7b31b357 | 6578 | -- If we have a short circuit form, and we are within the right |
6579 | -- hand expression, we return false, since the right hand side | |
6580 | -- is not guaranteed to be elaborated. | |
6581 | ||
6582 | if Nkind (P) in N_Short_Circuit | |
6583 | and then N = Right_Opnd (P) | |
6584 | then | |
6585 | return False; | |
6586 | end if; | |
6587 | ||
92f1631f | 6588 | -- Similarly, if we are in an if expression and not part of the |
6589 | -- condition, then we return False, since neither the THEN or | |
6590 | -- ELSE dependent expressions will always be elaborated. | |
7b31b357 | 6591 | |
92f1631f | 6592 | if Nkind (P) = N_If_Expression |
7b31b357 | 6593 | and then N /= First (Expressions (P)) |
6594 | then | |
6595 | return False; | |
e977c0cf | 6596 | end if; |
6597 | ||
20cf157b | 6598 | -- If within a case expression, and not part of the expression, |
6599 | -- then return False, since a particular dependent expression | |
6600 | -- may not always be elaborated | |
e977c0cf | 6601 | |
6602 | if Nkind (P) = N_Case_Expression | |
6603 | and then N /= Expression (P) | |
6604 | then | |
6605 | return False; | |
7b31b357 | 6606 | end if; |
6607 | ||
20cf157b | 6608 | -- While traversing the parent chain, if node N belongs to a |
6609 | -- statement, then it may never appear in a declarative region. | |
7870823d | 6610 | |
6611 | if Nkind (P) in N_Statement_Other_Than_Procedure_Call | |
6612 | or else Nkind (P) = N_Procedure_Call_Statement | |
6613 | then | |
6614 | return False; | |
6615 | end if; | |
6616 | ||
7b31b357 | 6617 | -- If we are at a declaration, record it and exit |
6618 | ||
7870823d | 6619 | if Nkind (P) in N_Declaration |
6620 | and then Nkind (P) not in N_Subprogram_Specification | |
6621 | then | |
6622 | N_Decl := P; | |
6623 | exit; | |
6624 | end if; | |
6625 | ||
6626 | P := Parent (P); | |
6627 | end loop; | |
6628 | ||
6629 | if No (N_Decl) then | |
6630 | return False; | |
6631 | end if; | |
6632 | ||
6633 | return List_Containing (N_Decl) = Declarations (S_Par); | |
6634 | end; | |
7b31b357 | 6635 | end Safe_To_Capture_In_Parameter_Value; |
84d0d4a5 | 6636 | |
6637 | ------------------- | |
6638 | -- Mark_Non_Null -- | |
6639 | ------------------- | |
6640 | ||
6641 | procedure Mark_Non_Null is | |
6642 | begin | |
7870823d | 6643 | -- Only case of interest is if node N is an entity name |
6644 | ||
84d0d4a5 | 6645 | if Is_Entity_Name (N) then |
7870823d | 6646 | |
6647 | -- For sure, we want to clear an indication that this is known to | |
6648 | -- be null, since if we get past this check, it definitely is not! | |
6649 | ||
84d0d4a5 | 6650 | Set_Is_Known_Null (Entity (N), False); |
6651 | ||
7870823d | 6652 | -- We can mark the entity as known to be non-null if either it is |
6653 | -- safe to capture the value, or in the case of an IN parameter, | |
6654 | -- which is a constant, if the check we just installed is in the | |
6655 | -- declarative region of the subprogram body. In this latter case, | |
7b31b357 | 6656 | -- a check is decisive for the rest of the body if the expression |
6657 | -- is sure to be elaborated, since we know we have to elaborate | |
6658 | -- all declarations before executing the body. | |
6659 | ||
6660 | -- Couldn't this always be part of Safe_To_Capture_Value ??? | |
7870823d | 6661 | |
6662 | if Safe_To_Capture_Value (N, Entity (N)) | |
7b31b357 | 6663 | or else Safe_To_Capture_In_Parameter_Value |
7870823d | 6664 | then |
6665 | Set_Is_Known_Non_Null (Entity (N)); | |
84d0d4a5 | 6666 | end if; |
6667 | end if; | |
6668 | end Mark_Non_Null; | |
6669 | ||
6670 | -- Start of processing for Install_Null_Excluding_Check | |
fa7497e8 | 6671 | |
6672 | begin | |
84d0d4a5 | 6673 | pragma Assert (Is_Access_Type (Typ)); |
fa7497e8 | 6674 | |
46e32b5e | 6675 | -- No check inside a generic, check will be emitted in instance |
fa7497e8 | 6676 | |
84d0d4a5 | 6677 | if Inside_A_Generic then |
fa7497e8 | 6678 | return; |
84d0d4a5 | 6679 | end if; |
6680 | ||
6681 | -- No check needed if known to be non-null | |
6682 | ||
6683 | if Known_Non_Null (N) then | |
05fcfafb | 6684 | return; |
84d0d4a5 | 6685 | end if; |
fa7497e8 | 6686 | |
84d0d4a5 | 6687 | -- If known to be null, here is where we generate a compile time check |
6688 | ||
6689 | if Known_Null (N) then | |
d16989f1 | 6690 | |
20cf157b | 6691 | -- Avoid generating warning message inside init procs. In SPARK mode |
6692 | -- we can go ahead and call Apply_Compile_Time_Constraint_Error | |
46e32b5e | 6693 | -- since it will be turned into an error in any case. |
d16989f1 | 6694 | |
46e32b5e | 6695 | if (not Inside_Init_Proc or else SPARK_Mode = On) |
6696 | ||
6697 | -- Do not emit the warning within a conditional expression | |
6698 | -- Why not ??? | |
6699 | ||
6700 | and then not Within_Case_Or_If_Expression (N) | |
6701 | then | |
d16989f1 | 6702 | Apply_Compile_Time_Constraint_Error |
4098232e | 6703 | (N, "null value not allowed here??", CE_Access_Check_Failed); |
46e32b5e | 6704 | |
6705 | -- Remaining cases, where we silently insert the raise | |
6706 | ||
d16989f1 | 6707 | else |
6708 | Insert_Action (N, | |
6709 | Make_Raise_Constraint_Error (Loc, | |
6710 | Reason => CE_Access_Check_Failed)); | |
6711 | end if; | |
6712 | ||
84d0d4a5 | 6713 | Mark_Non_Null; |
6714 | return; | |
6715 | end if; | |
6716 | ||
6717 | -- If entity is never assigned, for sure a warning is appropriate | |
6718 | ||
6719 | if Is_Entity_Name (N) then | |
6720 | Check_Unset_Reference (N); | |
fa7497e8 | 6721 | end if; |
84d0d4a5 | 6722 | |
6723 | -- No check needed if checks are suppressed on the range. Note that we | |
6724 | -- don't set Is_Known_Non_Null in this case (we could legitimately do | |
6725 | -- so, since the program is erroneous, but we don't like to casually | |
6726 | -- propagate such conclusions from erroneosity). | |
6727 | ||
6728 | if Access_Checks_Suppressed (Typ) then | |
6729 | return; | |
6730 | end if; | |
6731 | ||
2af58f67 | 6732 | -- No check needed for access to concurrent record types generated by |
6733 | -- the expander. This is not just an optimization (though it does indeed | |
6734 | -- remove junk checks). It also avoids generation of junk warnings. | |
6735 | ||
6736 | if Nkind (N) in N_Has_Chars | |
6737 | and then Chars (N) = Name_uObject | |
6738 | and then Is_Concurrent_Record_Type | |
6739 | (Directly_Designated_Type (Etype (N))) | |
6740 | then | |
6741 | return; | |
6742 | end if; | |
6743 | ||
228836e8 | 6744 | -- No check needed in interface thunks since the runtime check is |
6745 | -- already performed at the caller side. | |
6746 | ||
6747 | if Is_Thunk (Current_Scope) then | |
6748 | return; | |
6749 | end if; | |
6750 | ||
472ea160 | 6751 | -- No check needed for the Get_Current_Excep.all.all idiom generated by |
6752 | -- the expander within exception handlers, since we know that the value | |
6753 | -- can never be null. | |
6754 | ||
6755 | -- Is this really the right way to do this? Normally we generate such | |
6756 | -- code in the expander with checks off, and that's how we suppress this | |
6757 | -- kind of junk check ??? | |
6758 | ||
6759 | if Nkind (N) = N_Function_Call | |
6760 | and then Nkind (Name (N)) = N_Explicit_Dereference | |
6761 | and then Nkind (Prefix (Name (N))) = N_Identifier | |
6762 | and then Is_RTE (Entity (Prefix (Name (N))), RE_Get_Current_Excep) | |
6763 | then | |
6764 | return; | |
6765 | end if; | |
6766 | ||
84d0d4a5 | 6767 | -- Otherwise install access check |
6768 | ||
6769 | Insert_Action (N, | |
6770 | Make_Raise_Constraint_Error (Loc, | |
6771 | Condition => | |
6772 | Make_Op_Eq (Loc, | |
6773 | Left_Opnd => Duplicate_Subexpr_Move_Checks (N), | |
6774 | Right_Opnd => Make_Null (Loc)), | |
6775 | Reason => CE_Access_Check_Failed)); | |
6776 | ||
6777 | Mark_Non_Null; | |
fa7497e8 | 6778 | end Install_Null_Excluding_Check; |
6779 | ||
ee6ba406 | 6780 | -------------------------- |
6781 | -- Install_Static_Check -- | |
6782 | -------------------------- | |
6783 | ||
6784 | procedure Install_Static_Check (R_Cno : Node_Id; Loc : Source_Ptr) is | |
6785 | Stat : constant Boolean := Is_Static_Expression (R_Cno); | |
6786 | Typ : constant Entity_Id := Etype (R_Cno); | |
6787 | ||
6788 | begin | |
f15731c4 | 6789 | Rewrite (R_Cno, |
6790 | Make_Raise_Constraint_Error (Loc, | |
6791 | Reason => CE_Range_Check_Failed)); | |
ee6ba406 | 6792 | Set_Analyzed (R_Cno); |
6793 | Set_Etype (R_Cno, Typ); | |
6794 | Set_Raises_Constraint_Error (R_Cno); | |
6795 | Set_Is_Static_Expression (R_Cno, Stat); | |
840ab274 | 6796 | |
6797 | -- Now deal with possible local raise handling | |
6798 | ||
6799 | Possible_Local_Raise (R_Cno, Standard_Constraint_Error); | |
ee6ba406 | 6800 | end Install_Static_Check; |
6801 | ||
3cce7f32 | 6802 | ------------------------- |
6803 | -- Is_Check_Suppressed -- | |
6804 | ------------------------- | |
6805 | ||
6806 | function Is_Check_Suppressed (E : Entity_Id; C : Check_Id) return Boolean is | |
6807 | Ptr : Suppress_Stack_Entry_Ptr; | |
6808 | ||
6809 | begin | |
6810 | -- First search the local entity suppress stack. We search this from the | |
6811 | -- top of the stack down so that we get the innermost entry that applies | |
6812 | -- to this case if there are nested entries. | |
6813 | ||
6814 | Ptr := Local_Suppress_Stack_Top; | |
6815 | while Ptr /= null loop | |
6816 | if (Ptr.Entity = Empty or else Ptr.Entity = E) | |
6817 | and then (Ptr.Check = All_Checks or else Ptr.Check = C) | |
6818 | then | |
6819 | return Ptr.Suppress; | |
6820 | end if; | |
6821 | ||
6822 | Ptr := Ptr.Prev; | |
6823 | end loop; | |
6824 | ||
6825 | -- Now search the global entity suppress table for a matching entry. | |
6826 | -- We also search this from the top down so that if there are multiple | |
6827 | -- pragmas for the same entity, the last one applies (not clear what | |
6828 | -- or whether the RM specifies this handling, but it seems reasonable). | |
6829 | ||
6830 | Ptr := Global_Suppress_Stack_Top; | |
6831 | while Ptr /= null loop | |
6832 | if (Ptr.Entity = Empty or else Ptr.Entity = E) | |
6833 | and then (Ptr.Check = All_Checks or else Ptr.Check = C) | |
6834 | then | |
6835 | return Ptr.Suppress; | |
6836 | end if; | |
6837 | ||
6838 | Ptr := Ptr.Prev; | |
6839 | end loop; | |
6840 | ||
6841 | -- If we did not find a matching entry, then use the normal scope | |
6842 | -- suppress value after all (actually this will be the global setting | |
6843 | -- since it clearly was not overridden at any point). For a predefined | |
6844 | -- check, we test the specific flag. For a user defined check, we check | |
6845 | -- the All_Checks flag. The Overflow flag requires special handling to | |
6846 | -- deal with the General vs Assertion case | |
6847 | ||
6848 | if C = Overflow_Check then | |
6849 | return Overflow_Checks_Suppressed (Empty); | |
6850 | elsif C in Predefined_Check_Id then | |
6851 | return Scope_Suppress.Suppress (C); | |
6852 | else | |
6853 | return Scope_Suppress.Suppress (All_Checks); | |
6854 | end if; | |
6855 | end Is_Check_Suppressed; | |
6856 | ||
9dfe12ae | 6857 | --------------------- |
6858 | -- Kill_All_Checks -- | |
6859 | --------------------- | |
6860 | ||
6861 | procedure Kill_All_Checks is | |
6862 | begin | |
6863 | if Debug_Flag_CC then | |
6864 | w ("Kill_All_Checks"); | |
6865 | end if; | |
6866 | ||
feff2f05 | 6867 | -- We reset the number of saved checks to zero, and also modify all |
6868 | -- stack entries for statement ranges to indicate that the number of | |
6869 | -- checks at each level is now zero. | |
9dfe12ae | 6870 | |
6871 | Num_Saved_Checks := 0; | |
6872 | ||
96da3284 | 6873 | -- Note: the Int'Min here avoids any possibility of J being out of |
6874 | -- range when called from e.g. Conditional_Statements_Begin. | |
6875 | ||
6876 | for J in 1 .. Int'Min (Saved_Checks_TOS, Saved_Checks_Stack'Last) loop | |
9dfe12ae | 6877 | Saved_Checks_Stack (J) := 0; |
6878 | end loop; | |
6879 | end Kill_All_Checks; | |
6880 | ||
6881 | ----------------- | |
6882 | -- Kill_Checks -- | |
6883 | ----------------- | |
6884 | ||
6885 | procedure Kill_Checks (V : Entity_Id) is | |
6886 | begin | |
6887 | if Debug_Flag_CC then | |
6888 | w ("Kill_Checks for entity", Int (V)); | |
6889 | end if; | |
6890 | ||
6891 | for J in 1 .. Num_Saved_Checks loop | |
6892 | if Saved_Checks (J).Entity = V then | |
6893 | if Debug_Flag_CC then | |
6894 | w (" Checks killed for saved check ", J); | |
6895 | end if; | |
6896 | ||
6897 | Saved_Checks (J).Killed := True; | |
6898 | end if; | |
6899 | end loop; | |
6900 | end Kill_Checks; | |
6901 | ||
ee6ba406 | 6902 | ------------------------------ |
6903 | -- Length_Checks_Suppressed -- | |
6904 | ------------------------------ | |
6905 | ||
6906 | function Length_Checks_Suppressed (E : Entity_Id) return Boolean is | |
6907 | begin | |
9dfe12ae | 6908 | if Present (E) and then Checks_May_Be_Suppressed (E) then |
6909 | return Is_Check_Suppressed (E, Length_Check); | |
6910 | else | |
fafc6b97 | 6911 | return Scope_Suppress.Suppress (Length_Check); |
9dfe12ae | 6912 | end if; |
ee6ba406 | 6913 | end Length_Checks_Suppressed; |
6914 | ||
3cce7f32 | 6915 | ----------------------- |
6916 | -- Make_Bignum_Block -- | |
6917 | ----------------------- | |
6918 | ||
6919 | function Make_Bignum_Block (Loc : Source_Ptr) return Node_Id is | |
6920 | M : constant Entity_Id := Make_Defining_Identifier (Loc, Name_uM); | |
ee6ba406 | 6921 | |
3cce7f32 | 6922 | begin |
6923 | return | |
6924 | Make_Block_Statement (Loc, | |
6925 | Declarations => New_List ( | |
6926 | Make_Object_Declaration (Loc, | |
6927 | Defining_Identifier => M, | |
6928 | Object_Definition => | |
6929 | New_Occurrence_Of (RTE (RE_Mark_Id), Loc), | |
6930 | Expression => | |
6931 | Make_Function_Call (Loc, | |
6932 | Name => New_Reference_To (RTE (RE_SS_Mark), Loc)))), | |
6933 | ||
6934 | Handled_Statement_Sequence => | |
6935 | Make_Handled_Sequence_Of_Statements (Loc, | |
6936 | Statements => New_List ( | |
6937 | Make_Procedure_Call_Statement (Loc, | |
6938 | Name => New_Occurrence_Of (RTE (RE_SS_Release), Loc), | |
6939 | Parameter_Associations => New_List ( | |
6940 | New_Reference_To (M, Loc)))))); | |
6941 | end Make_Bignum_Block; | |
6942 | ||
0df9d43f | 6943 | ---------------------------------- |
6944 | -- Minimize_Eliminate_Overflows -- | |
6945 | ---------------------------------- | |
3cce7f32 | 6946 | |
f32c377d | 6947 | -- This is a recursive routine that is called at the top of an expression |
6948 | -- tree to properly process overflow checking for a whole subtree by making | |
6949 | -- recursive calls to process operands. This processing may involve the use | |
6950 | -- of bignum or long long integer arithmetic, which will change the types | |
6951 | -- of operands and results. That's why we can't do this bottom up (since | |
21a55437 | 6952 | -- it would interfere with semantic analysis). |
f32c377d | 6953 | |
21a55437 | 6954 | -- What happens is that if MINIMIZED/ELIMINATED mode is in effect then |
0df9d43f | 6955 | -- the operator expansion routines, as well as the expansion routines for |
6956 | -- if/case expression, do nothing (for the moment) except call the routine | |
6957 | -- to apply the overflow check (Apply_Arithmetic_Overflow_Check). That | |
6958 | -- routine does nothing for non top-level nodes, so at the point where the | |
6959 | -- call is made for the top level node, the entire expression subtree has | |
6960 | -- not been expanded, or processed for overflow. All that has to happen as | |
6961 | -- a result of the top level call to this routine. | |
f32c377d | 6962 | |
6963 | -- As noted above, the overflow processing works by making recursive calls | |
6964 | -- for the operands, and figuring out what to do, based on the processing | |
6965 | -- of these operands (e.g. if a bignum operand appears, the parent op has | |
6966 | -- to be done in bignum mode), and the determined ranges of the operands. | |
6967 | ||
6968 | -- After possible rewriting of a constituent subexpression node, a call is | |
4fb5f0a0 | 6969 | -- made to either reexpand the node (if nothing has changed) or reanalyze |
21a55437 | 6970 | -- the node (if it has been modified by the overflow check processing). The |
6971 | -- Analyzed_Flag is set to False before the reexpand/reanalyze. To avoid | |
6972 | -- a recursive call into the whole overflow apparatus, an important rule | |
0df9d43f | 6973 | -- for this call is that the overflow handling mode must be temporarily set |
6974 | -- to STRICT. | |
f32c377d | 6975 | |
0df9d43f | 6976 | procedure Minimize_Eliminate_Overflows |
61016a7a | 6977 | (N : Node_Id; |
6978 | Lo : out Uint; | |
6979 | Hi : out Uint; | |
6980 | Top_Level : Boolean) | |
3cce7f32 | 6981 | is |
0326b4d4 | 6982 | Rtyp : constant Entity_Id := Etype (N); |
6983 | pragma Assert (Is_Signed_Integer_Type (Rtyp)); | |
6984 | -- Result type, must be a signed integer type | |
3cce7f32 | 6985 | |
db415383 | 6986 | Check_Mode : constant Overflow_Mode_Type := Overflow_Check_Mode; |
3cce7f32 | 6987 | pragma Assert (Check_Mode in Minimized_Or_Eliminated); |
6988 | ||
6989 | Loc : constant Source_Ptr := Sloc (N); | |
6990 | ||
6991 | Rlo, Rhi : Uint; | |
0326b4d4 | 6992 | -- Ranges of values for right operand (operator case) |
3cce7f32 | 6993 | |
6994 | Llo, Lhi : Uint; | |
0326b4d4 | 6995 | -- Ranges of values for left operand (operator case) |
3cce7f32 | 6996 | |
49b3a812 | 6997 | LLIB : constant Entity_Id := Base_Type (Standard_Long_Long_Integer); |
6998 | -- Operands and results are of this type when we convert | |
6999 | ||
0326b4d4 | 7000 | LLLo : constant Uint := Intval (Type_Low_Bound (LLIB)); |
7001 | LLHi : constant Uint := Intval (Type_High_Bound (LLIB)); | |
3cce7f32 | 7002 | -- Bounds of Long_Long_Integer |
7003 | ||
7004 | Binary : constant Boolean := Nkind (N) in N_Binary_Op; | |
7005 | -- Indicates binary operator case | |
7006 | ||
7007 | OK : Boolean; | |
7008 | -- Used in call to Determine_Range | |
7009 | ||
61016a7a | 7010 | Bignum_Operands : Boolean; |
7011 | -- Set True if one or more operands is already of type Bignum, meaning | |
7012 | -- that for sure (regardless of Top_Level setting) we are committed to | |
0326b4d4 | 7013 | -- doing the operation in Bignum mode (or in the case of a case or if |
21a55437 | 7014 | -- expression, converting all the dependent expressions to Bignum). |
0326b4d4 | 7015 | |
7016 | Long_Long_Integer_Operands : Boolean; | |
21a55437 | 7017 | -- Set True if one or more operands is already of type Long_Long_Integer |
0326b4d4 | 7018 | -- which means that if the result is known to be in the result type |
7019 | -- range, then we must convert such operands back to the result type. | |
0df9d43f | 7020 | |
7021 | procedure Reanalyze (Typ : Entity_Id; Suppress : Boolean := False); | |
7022 | -- This is called when we have modified the node and we therefore need | |
7023 | -- to reanalyze it. It is important that we reset the mode to STRICT for | |
7024 | -- this reanalysis, since if we leave it in MINIMIZED or ELIMINATED mode | |
7025 | -- we would reenter this routine recursively which would not be good! | |
7026 | -- The argument Suppress is set True if we also want to suppress | |
7027 | -- overflow checking for the reexpansion (this is set when we know | |
7028 | -- overflow is not possible). Typ is the type for the reanalysis. | |
7029 | ||
7030 | procedure Reexpand (Suppress : Boolean := False); | |
7031 | -- This is like Reanalyze, but does not do the Analyze step, it only | |
7032 | -- does a reexpansion. We do this reexpansion in STRICT mode, so that | |
7033 | -- instead of reentering the MINIMIZED/ELIMINATED mode processing, we | |
7034 | -- follow the normal expansion path (e.g. converting A**4 to A**2**2). | |
7035 | -- Note that skipping reanalysis is not just an optimization, testing | |
7036 | -- has showed up several complex cases in which reanalyzing an already | |
7037 | -- analyzed node causes incorrect behavior. | |
4fb5f0a0 | 7038 | |
0326b4d4 | 7039 | function In_Result_Range return Boolean; |
7040 | -- Returns True iff Lo .. Hi are within range of the result type | |
61016a7a | 7041 | |
2fe22c69 | 7042 | procedure Max (A : in out Uint; B : Uint); |
21a55437 | 7043 | -- If A is No_Uint, sets A to B, else to UI_Max (A, B) |
2fe22c69 | 7044 | |
7045 | procedure Min (A : in out Uint; B : Uint); | |
21a55437 | 7046 | -- If A is No_Uint, sets A to B, else to UI_Min (A, B) |
2fe22c69 | 7047 | |
0326b4d4 | 7048 | --------------------- |
7049 | -- In_Result_Range -- | |
7050 | --------------------- | |
7051 | ||
7052 | function In_Result_Range return Boolean is | |
7053 | begin | |
f32c377d | 7054 | if Lo = No_Uint or else Hi = No_Uint then |
7055 | return False; | |
7056 | ||
7057 | elsif Is_Static_Subtype (Etype (N)) then | |
0326b4d4 | 7058 | return Lo >= Expr_Value (Type_Low_Bound (Rtyp)) |
7059 | and then | |
7060 | Hi <= Expr_Value (Type_High_Bound (Rtyp)); | |
f32c377d | 7061 | |
0326b4d4 | 7062 | else |
7063 | return Lo >= Expr_Value (Type_Low_Bound (Base_Type (Rtyp))) | |
7064 | and then | |
7065 | Hi <= Expr_Value (Type_High_Bound (Base_Type (Rtyp))); | |
7066 | end if; | |
7067 | end In_Result_Range; | |
7068 | ||
2fe22c69 | 7069 | --------- |
7070 | -- Max -- | |
7071 | --------- | |
7072 | ||
7073 | procedure Max (A : in out Uint; B : Uint) is | |
7074 | begin | |
7075 | if A = No_Uint or else B > A then | |
7076 | A := B; | |
7077 | end if; | |
7078 | end Max; | |
7079 | ||
7080 | --------- | |
7081 | -- Min -- | |
7082 | --------- | |
7083 | ||
7084 | procedure Min (A : in out Uint; B : Uint) is | |
7085 | begin | |
7086 | if A = No_Uint or else B < A then | |
7087 | A := B; | |
7088 | end if; | |
7089 | end Min; | |
7090 | ||
0df9d43f | 7091 | --------------- |
7092 | -- Reanalyze -- | |
7093 | --------------- | |
7094 | ||
7095 | procedure Reanalyze (Typ : Entity_Id; Suppress : Boolean := False) is | |
db415383 | 7096 | Svg : constant Overflow_Mode_Type := |
7097 | Scope_Suppress.Overflow_Mode_General; | |
7098 | Sva : constant Overflow_Mode_Type := | |
7099 | Scope_Suppress.Overflow_Mode_Assertions; | |
0df9d43f | 7100 | Svo : constant Boolean := |
7101 | Scope_Suppress.Suppress (Overflow_Check); | |
7102 | ||
7103 | begin | |
db415383 | 7104 | Scope_Suppress.Overflow_Mode_General := Strict; |
7105 | Scope_Suppress.Overflow_Mode_Assertions := Strict; | |
0df9d43f | 7106 | |
7107 | if Suppress then | |
7108 | Scope_Suppress.Suppress (Overflow_Check) := True; | |
7109 | end if; | |
7110 | ||
7111 | Analyze_And_Resolve (N, Typ); | |
7112 | ||
7113 | Scope_Suppress.Suppress (Overflow_Check) := Svo; | |
db415383 | 7114 | Scope_Suppress.Overflow_Mode_General := Svg; |
7115 | Scope_Suppress.Overflow_Mode_Assertions := Sva; | |
0df9d43f | 7116 | end Reanalyze; |
7117 | ||
4fb5f0a0 | 7118 | -------------- |
7119 | -- Reexpand -- | |
7120 | -------------- | |
7121 | ||
0df9d43f | 7122 | procedure Reexpand (Suppress : Boolean := False) is |
db415383 | 7123 | Svg : constant Overflow_Mode_Type := |
7124 | Scope_Suppress.Overflow_Mode_General; | |
7125 | Sva : constant Overflow_Mode_Type := | |
7126 | Scope_Suppress.Overflow_Mode_Assertions; | |
0df9d43f | 7127 | Svo : constant Boolean := |
7128 | Scope_Suppress.Suppress (Overflow_Check); | |
7129 | ||
4fb5f0a0 | 7130 | begin |
db415383 | 7131 | Scope_Suppress.Overflow_Mode_General := Strict; |
7132 | Scope_Suppress.Overflow_Mode_Assertions := Strict; | |
4fb5f0a0 | 7133 | Set_Analyzed (N, False); |
0df9d43f | 7134 | |
7135 | if Suppress then | |
7136 | Scope_Suppress.Suppress (Overflow_Check) := True; | |
7137 | end if; | |
7138 | ||
4fb5f0a0 | 7139 | Expand (N); |
0df9d43f | 7140 | |
7141 | Scope_Suppress.Suppress (Overflow_Check) := Svo; | |
db415383 | 7142 | Scope_Suppress.Overflow_Mode_General := Svg; |
7143 | Scope_Suppress.Overflow_Mode_Assertions := Sva; | |
4fb5f0a0 | 7144 | end Reexpand; |
7145 | ||
0df9d43f | 7146 | -- Start of processing for Minimize_Eliminate_Overflows |
2fe22c69 | 7147 | |
3cce7f32 | 7148 | begin |
0326b4d4 | 7149 | -- Case where we do not have a signed integer arithmetic operation |
3cce7f32 | 7150 | |
7151 | if not Is_Signed_Integer_Arithmetic_Op (N) then | |
7152 | ||
7153 | -- Use the normal Determine_Range routine to get the range. We | |
7154 | -- don't require operands to be valid, invalid values may result in | |
7155 | -- rubbish results where the result has not been properly checked for | |
7156 | -- overflow, that's fine! | |
7157 | ||
7158 | Determine_Range (N, OK, Lo, Hi, Assume_Valid => False); | |
7159 | ||
21a55437 | 7160 | -- If Determine_Range did not work (can this in fact happen? Not |
3cce7f32 | 7161 | -- clear but might as well protect), use type bounds. |
7162 | ||
7163 | if not OK then | |
7164 | Lo := Intval (Type_Low_Bound (Base_Type (Etype (N)))); | |
7165 | Hi := Intval (Type_High_Bound (Base_Type (Etype (N)))); | |
7166 | end if; | |
7167 | ||
7168 | -- If we don't have a binary operator, all we have to do is to set | |
20cf157b | 7169 | -- the Hi/Lo range, so we are done. |
3cce7f32 | 7170 | |
7171 | return; | |
7172 | ||
0326b4d4 | 7173 | -- Processing for if expression |
7174 | ||
92f1631f | 7175 | elsif Nkind (N) = N_If_Expression then |
0326b4d4 | 7176 | declare |
7177 | Then_DE : constant Node_Id := Next (First (Expressions (N))); | |
7178 | Else_DE : constant Node_Id := Next (Then_DE); | |
7179 | ||
7180 | begin | |
7181 | Bignum_Operands := False; | |
7182 | ||
0df9d43f | 7183 | Minimize_Eliminate_Overflows |
0326b4d4 | 7184 | (Then_DE, Lo, Hi, Top_Level => False); |
7185 | ||
7186 | if Lo = No_Uint then | |
7187 | Bignum_Operands := True; | |
7188 | end if; | |
7189 | ||
0df9d43f | 7190 | Minimize_Eliminate_Overflows |
0326b4d4 | 7191 | (Else_DE, Rlo, Rhi, Top_Level => False); |
7192 | ||
7193 | if Rlo = No_Uint then | |
7194 | Bignum_Operands := True; | |
7195 | else | |
7196 | Long_Long_Integer_Operands := | |
7197 | Etype (Then_DE) = LLIB or else Etype (Else_DE) = LLIB; | |
7198 | ||
7199 | Min (Lo, Rlo); | |
7200 | Max (Hi, Rhi); | |
7201 | end if; | |
7202 | ||
21a55437 | 7203 | -- If at least one of our operands is now Bignum, we must rebuild |
7204 | -- the if expression to use Bignum operands. We will analyze the | |
0326b4d4 | 7205 | -- rebuilt if expression with overflow checks off, since once we |
7206 | -- are in bignum mode, we are all done with overflow checks! | |
7207 | ||
7208 | if Bignum_Operands then | |
7209 | Rewrite (N, | |
92f1631f | 7210 | Make_If_Expression (Loc, |
0326b4d4 | 7211 | Expressions => New_List ( |
7212 | Remove_Head (Expressions (N)), | |
7213 | Convert_To_Bignum (Then_DE), | |
7214 | Convert_To_Bignum (Else_DE)), | |
7215 | Is_Elsif => Is_Elsif (N))); | |
7216 | ||
0df9d43f | 7217 | Reanalyze (RTE (RE_Bignum), Suppress => True); |
0326b4d4 | 7218 | |
7219 | -- If we have no Long_Long_Integer operands, then we are in result | |
7220 | -- range, since it means that none of our operands felt the need | |
7221 | -- to worry about overflow (otherwise it would have already been | |
4fb5f0a0 | 7222 | -- converted to long long integer or bignum). We reexpand to |
7223 | -- complete the expansion of the if expression (but we do not | |
7224 | -- need to reanalyze). | |
0326b4d4 | 7225 | |
7226 | elsif not Long_Long_Integer_Operands then | |
7227 | Set_Do_Overflow_Check (N, False); | |
0df9d43f | 7228 | Reexpand; |
0326b4d4 | 7229 | |
7230 | -- Otherwise convert us to long long integer mode. Note that we | |
7231 | -- don't need any further overflow checking at this level. | |
7232 | ||
7233 | else | |
7234 | Convert_To_And_Rewrite (LLIB, Then_DE); | |
7235 | Convert_To_And_Rewrite (LLIB, Else_DE); | |
7236 | Set_Etype (N, LLIB); | |
f32c377d | 7237 | |
7238 | -- Now reanalyze with overflow checks off | |
7239 | ||
0326b4d4 | 7240 | Set_Do_Overflow_Check (N, False); |
0df9d43f | 7241 | Reanalyze (LLIB, Suppress => True); |
0326b4d4 | 7242 | end if; |
7243 | end; | |
7244 | ||
7245 | return; | |
7246 | ||
7247 | -- Here for case expression | |
7248 | ||
7249 | elsif Nkind (N) = N_Case_Expression then | |
7250 | Bignum_Operands := False; | |
7251 | Long_Long_Integer_Operands := False; | |
0326b4d4 | 7252 | |
7253 | declare | |
f32c377d | 7254 | Alt : Node_Id; |
0326b4d4 | 7255 | |
7256 | begin | |
7257 | -- Loop through expressions applying recursive call | |
7258 | ||
7259 | Alt := First (Alternatives (N)); | |
7260 | while Present (Alt) loop | |
7261 | declare | |
7262 | Aexp : constant Node_Id := Expression (Alt); | |
7263 | ||
7264 | begin | |
0df9d43f | 7265 | Minimize_Eliminate_Overflows |
0326b4d4 | 7266 | (Aexp, Lo, Hi, Top_Level => False); |
7267 | ||
7268 | if Lo = No_Uint then | |
7269 | Bignum_Operands := True; | |
7270 | elsif Etype (Aexp) = LLIB then | |
7271 | Long_Long_Integer_Operands := True; | |
7272 | end if; | |
7273 | end; | |
7274 | ||
7275 | Next (Alt); | |
7276 | end loop; | |
7277 | ||
7278 | -- If we have no bignum or long long integer operands, it means | |
7279 | -- that none of our dependent expressions could raise overflow. | |
7280 | -- In this case, we simply return with no changes except for | |
7281 | -- resetting the overflow flag, since we are done with overflow | |
4fb5f0a0 | 7282 | -- checks for this node. We will reexpand to get the needed |
7283 | -- expansion for the case expression, but we do not need to | |
21a55437 | 7284 | -- reanalyze, since nothing has changed. |
0326b4d4 | 7285 | |
f32c377d | 7286 | if not (Bignum_Operands or Long_Long_Integer_Operands) then |
0326b4d4 | 7287 | Set_Do_Overflow_Check (N, False); |
0df9d43f | 7288 | Reexpand (Suppress => True); |
0326b4d4 | 7289 | |
7290 | -- Otherwise we are going to rebuild the case expression using | |
7291 | -- either bignum or long long integer operands throughout. | |
7292 | ||
7293 | else | |
f32c377d | 7294 | declare |
7295 | Rtype : Entity_Id; | |
7296 | New_Alts : List_Id; | |
7297 | New_Exp : Node_Id; | |
7298 | ||
7299 | begin | |
7300 | New_Alts := New_List; | |
7301 | Alt := First (Alternatives (N)); | |
7302 | while Present (Alt) loop | |
7303 | if Bignum_Operands then | |
7304 | New_Exp := Convert_To_Bignum (Expression (Alt)); | |
7305 | Rtype := RTE (RE_Bignum); | |
7306 | else | |
7307 | New_Exp := Convert_To (LLIB, Expression (Alt)); | |
7308 | Rtype := LLIB; | |
7309 | end if; | |
0326b4d4 | 7310 | |
f32c377d | 7311 | Append_To (New_Alts, |
7312 | Make_Case_Expression_Alternative (Sloc (Alt), | |
7313 | Actions => No_List, | |
7314 | Discrete_Choices => Discrete_Choices (Alt), | |
7315 | Expression => New_Exp)); | |
0326b4d4 | 7316 | |
f32c377d | 7317 | Next (Alt); |
7318 | end loop; | |
0326b4d4 | 7319 | |
f32c377d | 7320 | Rewrite (N, |
7321 | Make_Case_Expression (Loc, | |
7322 | Expression => Expression (N), | |
7323 | Alternatives => New_Alts)); | |
0326b4d4 | 7324 | |
0df9d43f | 7325 | Reanalyze (Rtype, Suppress => True); |
f32c377d | 7326 | end; |
0326b4d4 | 7327 | end if; |
7328 | end; | |
7329 | ||
7330 | return; | |
7331 | end if; | |
7332 | ||
7333 | -- If we have an arithmetic operator we make recursive calls on the | |
3cce7f32 | 7334 | -- operands to get the ranges (and to properly process the subtree |
20cf157b | 7335 | -- that lies below us). |
3cce7f32 | 7336 | |
0df9d43f | 7337 | Minimize_Eliminate_Overflows |
0326b4d4 | 7338 | (Right_Opnd (N), Rlo, Rhi, Top_Level => False); |
3cce7f32 | 7339 | |
0326b4d4 | 7340 | if Binary then |
0df9d43f | 7341 | Minimize_Eliminate_Overflows |
0326b4d4 | 7342 | (Left_Opnd (N), Llo, Lhi, Top_Level => False); |
3cce7f32 | 7343 | end if; |
7344 | ||
f32c377d | 7345 | -- Record if we have Long_Long_Integer operands |
7346 | ||
7347 | Long_Long_Integer_Operands := | |
7348 | Etype (Right_Opnd (N)) = LLIB | |
7349 | or else (Binary and then Etype (Left_Opnd (N)) = LLIB); | |
7350 | ||
7351 | -- If either operand is a bignum, then result will be a bignum and we | |
7352 | -- don't need to do any range analysis. As previously discussed we could | |
7353 | -- do range analysis in such cases, but it could mean working with giant | |
7354 | -- numbers at compile time for very little gain (the number of cases | |
21a55437 | 7355 | -- in which we could slip back from bignum mode is small). |
3cce7f32 | 7356 | |
7357 | if Rlo = No_Uint or else (Binary and then Llo = No_Uint) then | |
7358 | Lo := No_Uint; | |
7359 | Hi := No_Uint; | |
61016a7a | 7360 | Bignum_Operands := True; |
3cce7f32 | 7361 | |
7362 | -- Otherwise compute result range | |
7363 | ||
7364 | else | |
61016a7a | 7365 | Bignum_Operands := False; |
7366 | ||
3cce7f32 | 7367 | case Nkind (N) is |
7368 | ||
7369 | -- Absolute value | |
7370 | ||
7371 | when N_Op_Abs => | |
7372 | Lo := Uint_0; | |
de922300 | 7373 | Hi := UI_Max (abs Rlo, abs Rhi); |
3cce7f32 | 7374 | |
7375 | -- Addition | |
7376 | ||
7377 | when N_Op_Add => | |
7378 | Lo := Llo + Rlo; | |
7379 | Hi := Lhi + Rhi; | |
7380 | ||
7381 | -- Division | |
7382 | ||
7383 | when N_Op_Divide => | |
2fe22c69 | 7384 | |
5f4275e1 | 7385 | -- If the right operand can only be zero, set 0..0 |
2fe22c69 | 7386 | |
5f4275e1 | 7387 | if Rlo = 0 and then Rhi = 0 then |
7388 | Lo := Uint_0; | |
7389 | Hi := Uint_0; | |
2fe22c69 | 7390 | |
5f4275e1 | 7391 | -- Possible bounds of division must come from dividing end |
7392 | -- values of the input ranges (four possibilities), provided | |
7393 | -- zero is not included in the possible values of the right | |
7394 | -- operand. | |
7395 | ||
7396 | -- Otherwise, we just consider two intervals of values for | |
7397 | -- the right operand: the interval of negative values (up to | |
7398 | -- -1) and the interval of positive values (starting at 1). | |
7399 | -- Since division by 1 is the identity, and division by -1 | |
7400 | -- is negation, we get all possible bounds of division in that | |
7401 | -- case by considering: | |
7402 | -- - all values from the division of end values of input | |
7403 | -- ranges; | |
7404 | -- - the end values of the left operand; | |
7405 | -- - the negation of the end values of the left operand. | |
2fe22c69 | 7406 | |
5f4275e1 | 7407 | else |
7408 | declare | |
7409 | Mrk : constant Uintp.Save_Mark := Mark; | |
7410 | -- Mark so we can release the RR and Ev values | |
2fe22c69 | 7411 | |
5f4275e1 | 7412 | Ev1 : Uint; |
7413 | Ev2 : Uint; | |
7414 | Ev3 : Uint; | |
7415 | Ev4 : Uint; | |
2fe22c69 | 7416 | |
5f4275e1 | 7417 | begin |
7418 | -- Discard extreme values of zero for the divisor, since | |
7419 | -- they will simply result in an exception in any case. | |
2fe22c69 | 7420 | |
5f4275e1 | 7421 | if Rlo = 0 then |
7422 | Rlo := Uint_1; | |
7423 | elsif Rhi = 0 then | |
7424 | Rhi := -Uint_1; | |
2fe22c69 | 7425 | end if; |
2fe22c69 | 7426 | |
5f4275e1 | 7427 | -- Compute possible bounds coming from dividing end |
7428 | -- values of the input ranges. | |
2fe22c69 | 7429 | |
5f4275e1 | 7430 | Ev1 := Llo / Rlo; |
7431 | Ev2 := Llo / Rhi; | |
7432 | Ev3 := Lhi / Rlo; | |
7433 | Ev4 := Lhi / Rhi; | |
2fe22c69 | 7434 | |
5f4275e1 | 7435 | Lo := UI_Min (UI_Min (Ev1, Ev2), UI_Min (Ev3, Ev4)); |
7436 | Hi := UI_Max (UI_Max (Ev1, Ev2), UI_Max (Ev3, Ev4)); | |
2fe22c69 | 7437 | |
5f4275e1 | 7438 | -- If the right operand can be both negative or positive, |
7439 | -- include the end values of the left operand in the | |
7440 | -- extreme values, as well as their negation. | |
2fe22c69 | 7441 | |
5f4275e1 | 7442 | if Rlo < 0 and then Rhi > 0 then |
7443 | Ev1 := Llo; | |
7444 | Ev2 := -Llo; | |
7445 | Ev3 := Lhi; | |
7446 | Ev4 := -Lhi; | |
2fe22c69 | 7447 | |
5f4275e1 | 7448 | Min (Lo, |
7449 | UI_Min (UI_Min (Ev1, Ev2), UI_Min (Ev3, Ev4))); | |
7450 | Max (Hi, | |
7451 | UI_Max (UI_Max (Ev1, Ev2), UI_Max (Ev3, Ev4))); | |
2fe22c69 | 7452 | end if; |
2fe22c69 | 7453 | |
5f4275e1 | 7454 | -- Release the RR and Ev values |
2fe22c69 | 7455 | |
5f4275e1 | 7456 | Release_And_Save (Mrk, Lo, Hi); |
7457 | end; | |
7458 | end if; | |
3cce7f32 | 7459 | |
7460 | -- Exponentiation | |
7461 | ||
7462 | when N_Op_Expon => | |
de922300 | 7463 | |
7464 | -- Discard negative values for the exponent, since they will | |
7465 | -- simply result in an exception in any case. | |
7466 | ||
7467 | if Rhi < 0 then | |
7468 | Rhi := Uint_0; | |
7469 | elsif Rlo < 0 then | |
7470 | Rlo := Uint_0; | |
7471 | end if; | |
7472 | ||
7473 | -- Estimate number of bits in result before we go computing | |
7474 | -- giant useless bounds. Basically the number of bits in the | |
7475 | -- result is the number of bits in the base multiplied by the | |
7476 | -- value of the exponent. If this is big enough that the result | |
7477 | -- definitely won't fit in Long_Long_Integer, switch to bignum | |
7478 | -- mode immediately, and avoid computing giant bounds. | |
7479 | ||
7480 | -- The comparison here is approximate, but conservative, it | |
7481 | -- only clicks on cases that are sure to exceed the bounds. | |
7482 | ||
7483 | if Num_Bits (UI_Max (abs Llo, abs Lhi)) * Rhi + 1 > 100 then | |
7484 | Lo := No_Uint; | |
7485 | Hi := No_Uint; | |
7486 | ||
7487 | -- If right operand is zero then result is 1 | |
7488 | ||
7489 | elsif Rhi = 0 then | |
7490 | Lo := Uint_1; | |
7491 | Hi := Uint_1; | |
7492 | ||
7493 | else | |
7494 | -- High bound comes either from exponentiation of largest | |
5f4275e1 | 7495 | -- positive value to largest exponent value, or from |
7496 | -- the exponentiation of most negative value to an | |
7497 | -- even exponent. | |
de922300 | 7498 | |
7499 | declare | |
7500 | Hi1, Hi2 : Uint; | |
7501 | ||
7502 | begin | |
5f4275e1 | 7503 | if Lhi > 0 then |
de922300 | 7504 | Hi1 := Lhi ** Rhi; |
7505 | else | |
7506 | Hi1 := Uint_0; | |
7507 | end if; | |
7508 | ||
7509 | if Llo < 0 then | |
7510 | if Rhi mod 2 = 0 then | |
de922300 | 7511 | Hi2 := Llo ** Rhi; |
5f4275e1 | 7512 | else |
7513 | Hi2 := Llo ** (Rhi - 1); | |
de922300 | 7514 | end if; |
7515 | else | |
7516 | Hi2 := Uint_0; | |
7517 | end if; | |
7518 | ||
7519 | Hi := UI_Max (Hi1, Hi2); | |
7520 | end; | |
7521 | ||
7522 | -- Result can only be negative if base can be negative | |
7523 | ||
7524 | if Llo < 0 then | |
21a55437 | 7525 | if Rhi mod 2 = 0 then |
de922300 | 7526 | Lo := Llo ** (Rhi - 1); |
7527 | else | |
7528 | Lo := Llo ** Rhi; | |
7529 | end if; | |
7530 | ||
21a55437 | 7531 | -- Otherwise low bound is minimum ** minimum |
de922300 | 7532 | |
7533 | else | |
7534 | Lo := Llo ** Rlo; | |
7535 | end if; | |
7536 | end if; | |
3cce7f32 | 7537 | |
7538 | -- Negation | |
7539 | ||
7540 | when N_Op_Minus => | |
7541 | Lo := -Rhi; | |
7542 | Hi := -Rlo; | |
7543 | ||
7544 | -- Mod | |
7545 | ||
7546 | when N_Op_Mod => | |
2fe22c69 | 7547 | declare |
5f4275e1 | 7548 | Maxabs : constant Uint := UI_Max (abs Rlo, abs Rhi) - 1; |
2fe22c69 | 7549 | -- This is the maximum absolute value of the result |
7550 | ||
7551 | begin | |
7552 | Lo := Uint_0; | |
7553 | Hi := Uint_0; | |
7554 | ||
7555 | -- The result depends only on the sign and magnitude of | |
7556 | -- the right operand, it does not depend on the sign or | |
7557 | -- magnitude of the left operand. | |
7558 | ||
7559 | if Rlo < 0 then | |
7560 | Lo := -Maxabs; | |
7561 | end if; | |
7562 | ||
7563 | if Rhi > 0 then | |
7564 | Hi := Maxabs; | |
7565 | end if; | |
7566 | end; | |
3cce7f32 | 7567 | |
7568 | -- Multiplication | |
7569 | ||
7570 | when N_Op_Multiply => | |
49b3a812 | 7571 | |
7572 | -- Possible bounds of multiplication must come from multiplying | |
7573 | -- end values of the input ranges (four possibilities). | |
7574 | ||
7575 | declare | |
7576 | Mrk : constant Uintp.Save_Mark := Mark; | |
7577 | -- Mark so we can release the Ev values | |
7578 | ||
7579 | Ev1 : constant Uint := Llo * Rlo; | |
7580 | Ev2 : constant Uint := Llo * Rhi; | |
7581 | Ev3 : constant Uint := Lhi * Rlo; | |
7582 | Ev4 : constant Uint := Lhi * Rhi; | |
7583 | ||
7584 | begin | |
7585 | Lo := UI_Min (UI_Min (Ev1, Ev2), UI_Min (Ev3, Ev4)); | |
7586 | Hi := UI_Max (UI_Max (Ev1, Ev2), UI_Max (Ev3, Ev4)); | |
7587 | ||
7588 | -- Release the Ev values | |
7589 | ||
7590 | Release_And_Save (Mrk, Lo, Hi); | |
7591 | end; | |
3cce7f32 | 7592 | |
7593 | -- Plus operator (affirmation) | |
7594 | ||
7595 | when N_Op_Plus => | |
7596 | Lo := Rlo; | |
7597 | Hi := Rhi; | |
7598 | ||
7599 | -- Remainder | |
7600 | ||
7601 | when N_Op_Rem => | |
2fe22c69 | 7602 | declare |
5f4275e1 | 7603 | Maxabs : constant Uint := UI_Max (abs Rlo, abs Rhi) - 1; |
2fe22c69 | 7604 | -- This is the maximum absolute value of the result. Note |
5f4275e1 | 7605 | -- that the result range does not depend on the sign of the |
7606 | -- right operand. | |
2fe22c69 | 7607 | |
7608 | begin | |
7609 | Lo := Uint_0; | |
7610 | Hi := Uint_0; | |
7611 | ||
7612 | -- Case of left operand negative, which results in a range | |
7613 | -- of -Maxabs .. 0 for those negative values. If there are | |
7614 | -- no negative values then Lo value of result is always 0. | |
7615 | ||
7616 | if Llo < 0 then | |
7617 | Lo := -Maxabs; | |
7618 | end if; | |
7619 | ||
7620 | -- Case of left operand positive | |
7621 | ||
7622 | if Lhi > 0 then | |
7623 | Hi := Maxabs; | |
7624 | end if; | |
7625 | end; | |
3cce7f32 | 7626 | |
7627 | -- Subtract | |
7628 | ||
7629 | when N_Op_Subtract => | |
7630 | Lo := Llo - Rhi; | |
7631 | Hi := Lhi - Rlo; | |
7632 | ||
7633 | -- Nothing else should be possible | |
7634 | ||
7635 | when others => | |
7636 | raise Program_Error; | |
3cce7f32 | 7637 | end case; |
7638 | end if; | |
7639 | ||
4fb5f0a0 | 7640 | -- Here for the case where we have not rewritten anything (no bignum |
21a55437 | 7641 | -- operands or long long integer operands), and we know the result. |
7642 | -- If we know we are in the result range, and we do not have Bignum | |
7643 | -- operands or Long_Long_Integer operands, we can just reexpand with | |
7644 | -- overflow checks turned off (since we know we cannot have overflow). | |
7645 | -- As always the reexpansion is required to complete expansion of the | |
7646 | -- operator, but we do not need to reanalyze, and we prevent recursion | |
7647 | -- by suppressing the check. | |
f32c377d | 7648 | |
7649 | if not (Bignum_Operands or Long_Long_Integer_Operands) | |
7650 | and then In_Result_Range | |
7651 | then | |
7652 | Set_Do_Overflow_Check (N, False); | |
0df9d43f | 7653 | Reexpand (Suppress => True); |
f32c377d | 7654 | return; |
7655 | ||
7656 | -- Here we know that we are not in the result range, and in the general | |
21a55437 | 7657 | -- case we will move into either the Bignum or Long_Long_Integer domain |
7658 | -- to compute the result. However, there is one exception. If we are | |
7659 | -- at the top level, and we do not have Bignum or Long_Long_Integer | |
7660 | -- operands, we will have to immediately convert the result back to | |
7661 | -- the result type, so there is no point in Bignum/Long_Long_Integer | |
7662 | -- fiddling. | |
f32c377d | 7663 | |
7664 | elsif Top_Level | |
7665 | and then not (Bignum_Operands or Long_Long_Integer_Operands) | |
b6a8f264 | 7666 | |
7667 | -- One further refinement. If we are at the top level, but our parent | |
7668 | -- is a type conversion, then go into bignum or long long integer node | |
7669 | -- since the result will be converted to that type directly without | |
7670 | -- going through the result type, and we may avoid an overflow. This | |
7671 | -- is the case for example of Long_Long_Integer (A ** 4), where A is | |
7672 | -- of type Integer, and the result A ** 4 fits in Long_Long_Integer | |
7673 | -- but does not fit in Integer. | |
7674 | ||
7675 | and then Nkind (Parent (N)) /= N_Type_Conversion | |
f32c377d | 7676 | then |
0df9d43f | 7677 | -- Here keep original types, but we need to complete analysis |
f32c377d | 7678 | |
7679 | -- One subtlety. We can't just go ahead and do an analyze operation | |
21a55437 | 7680 | -- here because it will cause recursion into the whole MINIMIZED/ |
7681 | -- ELIMINATED overflow processing which is not what we want. Here | |
f32c377d | 7682 | -- we are at the top level, and we need a check against the result |
0df9d43f | 7683 | -- mode (i.e. we want to use STRICT mode). So do exactly that! |
4fb5f0a0 | 7684 | -- Also, we have not modified the node, so this is a case where |
7685 | -- we need to reexpand, but not reanalyze. | |
f32c377d | 7686 | |
0df9d43f | 7687 | Reexpand; |
f32c377d | 7688 | return; |
7689 | ||
7690 | -- Cases where we do the operation in Bignum mode. This happens either | |
3cce7f32 | 7691 | -- because one of our operands is in Bignum mode already, or because |
de922300 | 7692 | -- the computed bounds are outside the bounds of Long_Long_Integer, |
7693 | -- which in some cases can be indicated by Hi and Lo being No_Uint. | |
3cce7f32 | 7694 | |
7695 | -- Note: we could do better here and in some cases switch back from | |
7696 | -- Bignum mode to normal mode, e.g. big mod 2 must be in the range | |
7697 | -- 0 .. 1, but the cases are rare and it is not worth the effort. | |
7698 | -- Failing to do this switching back is only an efficiency issue. | |
7699 | ||
f32c377d | 7700 | elsif Lo = No_Uint or else Lo < LLLo or else Hi > LLHi then |
3cce7f32 | 7701 | |
61016a7a | 7702 | -- OK, we are definitely outside the range of Long_Long_Integer. The |
f32c377d | 7703 | -- question is whether to move to Bignum mode, or stay in the domain |
61016a7a | 7704 | -- of Long_Long_Integer, signalling that an overflow check is needed. |
7705 | ||
7706 | -- Obviously in MINIMIZED mode we stay with LLI, since we are not in | |
7707 | -- the Bignum business. In ELIMINATED mode, we will normally move | |
7708 | -- into Bignum mode, but there is an exception if neither of our | |
7709 | -- operands is Bignum now, and we are at the top level (Top_Level | |
7710 | -- set True). In this case, there is no point in moving into Bignum | |
7711 | -- mode to prevent overflow if the caller will immediately convert | |
7712 | -- the Bignum value back to LLI with an overflow check. It's more | |
0df9d43f | 7713 | -- efficient to stay in LLI mode with an overflow check (if needed) |
61016a7a | 7714 | |
7715 | if Check_Mode = Minimized | |
7716 | or else (Top_Level and not Bignum_Operands) | |
7717 | then | |
0df9d43f | 7718 | if Do_Overflow_Check (N) then |
7719 | Enable_Overflow_Check (N); | |
7720 | end if; | |
3cce7f32 | 7721 | |
0df9d43f | 7722 | -- The result now has to be in Long_Long_Integer mode, so adjust |
7723 | -- the possible range to reflect this. Note these calls also | |
7724 | -- change No_Uint values from the top level case to LLI bounds. | |
61016a7a | 7725 | |
7726 | Max (Lo, LLLo); | |
7727 | Min (Hi, LLHi); | |
7728 | ||
7729 | -- Otherwise we are in ELIMINATED mode and we switch to Bignum mode | |
3cce7f32 | 7730 | |
7731 | else | |
7732 | pragma Assert (Check_Mode = Eliminated); | |
7733 | ||
7734 | declare | |
7735 | Fent : Entity_Id; | |
7736 | Args : List_Id; | |
7737 | ||
7738 | begin | |
7739 | case Nkind (N) is | |
7740 | when N_Op_Abs => | |
7741 | Fent := RTE (RE_Big_Abs); | |
7742 | ||
7743 | when N_Op_Add => | |
7744 | Fent := RTE (RE_Big_Add); | |
7745 | ||
7746 | when N_Op_Divide => | |
7747 | Fent := RTE (RE_Big_Div); | |
7748 | ||
7749 | when N_Op_Expon => | |
7750 | Fent := RTE (RE_Big_Exp); | |
7751 | ||
7752 | when N_Op_Minus => | |
7753 | Fent := RTE (RE_Big_Neg); | |
7754 | ||
7755 | when N_Op_Mod => | |
7756 | Fent := RTE (RE_Big_Mod); | |
7757 | ||
7758 | when N_Op_Multiply => | |
7759 | Fent := RTE (RE_Big_Mul); | |
7760 | ||
7761 | when N_Op_Rem => | |
7762 | Fent := RTE (RE_Big_Rem); | |
7763 | ||
7764 | when N_Op_Subtract => | |
7765 | Fent := RTE (RE_Big_Sub); | |
7766 | ||
7767 | -- Anything else is an internal error, this includes the | |
7768 | -- N_Op_Plus case, since how can plus cause the result | |
7769 | -- to be out of range if the operand is in range? | |
7770 | ||
7771 | when others => | |
7772 | raise Program_Error; | |
7773 | end case; | |
7774 | ||
7775 | -- Construct argument list for Bignum call, converting our | |
7776 | -- operands to Bignum form if they are not already there. | |
7777 | ||
7778 | Args := New_List; | |
7779 | ||
7780 | if Binary then | |
7781 | Append_To (Args, Convert_To_Bignum (Left_Opnd (N))); | |
7782 | end if; | |
7783 | ||
7784 | Append_To (Args, Convert_To_Bignum (Right_Opnd (N))); | |
7785 | ||
7786 | -- Now rewrite the arithmetic operator with a call to the | |
7787 | -- corresponding bignum function. | |
7788 | ||
7789 | Rewrite (N, | |
7790 | Make_Function_Call (Loc, | |
7791 | Name => New_Occurrence_Of (Fent, Loc), | |
7792 | Parameter_Associations => Args)); | |
0df9d43f | 7793 | Reanalyze (RTE (RE_Bignum), Suppress => True); |
61016a7a | 7794 | |
7795 | -- Indicate result is Bignum mode | |
7796 | ||
7797 | Lo := No_Uint; | |
7798 | Hi := No_Uint; | |
de922300 | 7799 | return; |
3cce7f32 | 7800 | end; |
7801 | end if; | |
7802 | ||
7803 | -- Otherwise we are in range of Long_Long_Integer, so no overflow | |
de922300 | 7804 | -- check is required, at least not yet. |
3cce7f32 | 7805 | |
7806 | else | |
de922300 | 7807 | Set_Do_Overflow_Check (N, False); |
7808 | end if; | |
3cce7f32 | 7809 | |
f32c377d | 7810 | -- Here we are not in Bignum territory, but we may have long long |
7811 | -- integer operands that need special handling. First a special check: | |
7812 | -- If an exponentiation operator exponent is of type Long_Long_Integer, | |
7813 | -- it means we converted it to prevent overflow, but exponentiation | |
7814 | -- requires a Natural right operand, so convert it back to Natural. | |
7815 | -- This conversion may raise an exception which is fine. | |
0326b4d4 | 7816 | |
f32c377d | 7817 | if Nkind (N) = N_Op_Expon and then Etype (Right_Opnd (N)) = LLIB then |
7818 | Convert_To_And_Rewrite (Standard_Natural, Right_Opnd (N)); | |
0326b4d4 | 7819 | end if; |
7820 | ||
de922300 | 7821 | -- Here we will do the operation in Long_Long_Integer. We do this even |
7822 | -- if we know an overflow check is required, better to do this in long | |
7823 | -- long integer mode, since we are less likely to overflow! | |
3cce7f32 | 7824 | |
de922300 | 7825 | -- Convert right or only operand to Long_Long_Integer, except that |
7826 | -- we do not touch the exponentiation right operand. | |
3cce7f32 | 7827 | |
de922300 | 7828 | if Nkind (N) /= N_Op_Expon then |
7829 | Convert_To_And_Rewrite (LLIB, Right_Opnd (N)); | |
7830 | end if; | |
3cce7f32 | 7831 | |
de922300 | 7832 | -- Convert left operand to Long_Long_Integer for binary case |
49b3a812 | 7833 | |
de922300 | 7834 | if Binary then |
7835 | Convert_To_And_Rewrite (LLIB, Left_Opnd (N)); | |
7836 | end if; | |
7837 | ||
7838 | -- Reset node to unanalyzed | |
7839 | ||
7840 | Set_Analyzed (N, False); | |
7841 | Set_Etype (N, Empty); | |
7842 | Set_Entity (N, Empty); | |
7843 | ||
2fe22c69 | 7844 | -- Now analyze this new node. This reanalysis will complete processing |
7845 | -- for the node. In particular we will complete the expansion of an | |
7846 | -- exponentiation operator (e.g. changing A ** 2 to A * A), and also | |
7847 | -- we will complete any division checks (since we have not changed the | |
7848 | -- setting of the Do_Division_Check flag). | |
3cce7f32 | 7849 | |
0df9d43f | 7850 | -- We do this reanalysis in STRICT mode to avoid recursion into the |
7851 | -- MINIMIZED/ELIMINATED handling, since we are now done with that! | |
3cce7f32 | 7852 | |
0df9d43f | 7853 | declare |
db415383 | 7854 | SG : constant Overflow_Mode_Type := |
7855 | Scope_Suppress.Overflow_Mode_General; | |
7856 | SA : constant Overflow_Mode_Type := | |
7857 | Scope_Suppress.Overflow_Mode_Assertions; | |
de922300 | 7858 | |
0df9d43f | 7859 | begin |
db415383 | 7860 | Scope_Suppress.Overflow_Mode_General := Strict; |
7861 | Scope_Suppress.Overflow_Mode_Assertions := Strict; | |
de922300 | 7862 | |
0df9d43f | 7863 | if not Do_Overflow_Check (N) then |
7864 | Reanalyze (LLIB, Suppress => True); | |
7865 | else | |
7866 | Reanalyze (LLIB); | |
7867 | end if; | |
7868 | ||
db415383 | 7869 | Scope_Suppress.Overflow_Mode_General := SG; |
7870 | Scope_Suppress.Overflow_Mode_Assertions := SA; | |
0df9d43f | 7871 | end; |
7872 | end Minimize_Eliminate_Overflows; | |
3cce7f32 | 7873 | |
7874 | ------------------------- | |
7875 | -- Overflow_Check_Mode -- | |
7876 | ------------------------- | |
7877 | ||
db415383 | 7878 | function Overflow_Check_Mode return Overflow_Mode_Type is |
ee6ba406 | 7879 | begin |
724d2bd8 | 7880 | if In_Assertion_Expr = 0 then |
db415383 | 7881 | return Scope_Suppress.Overflow_Mode_General; |
9dfe12ae | 7882 | else |
db415383 | 7883 | return Scope_Suppress.Overflow_Mode_Assertions; |
9dfe12ae | 7884 | end if; |
3cce7f32 | 7885 | end Overflow_Check_Mode; |
7886 | ||
7887 | -------------------------------- | |
7888 | -- Overflow_Checks_Suppressed -- | |
7889 | -------------------------------- | |
7890 | ||
7891 | function Overflow_Checks_Suppressed (E : Entity_Id) return Boolean is | |
7892 | begin | |
0df9d43f | 7893 | if Present (E) and then Checks_May_Be_Suppressed (E) then |
7894 | return Is_Check_Suppressed (E, Overflow_Check); | |
7895 | else | |
7896 | return Scope_Suppress.Suppress (Overflow_Check); | |
7897 | end if; | |
ee6ba406 | 7898 | end Overflow_Checks_Suppressed; |
fc75802a | 7899 | |
37baba83 | 7900 | --------------------------------- |
7901 | -- Predicate_Checks_Suppressed -- | |
7902 | --------------------------------- | |
7903 | ||
7904 | function Predicate_Checks_Suppressed (E : Entity_Id) return Boolean is | |
7905 | begin | |
7906 | if Present (E) and then Checks_May_Be_Suppressed (E) then | |
7907 | return Is_Check_Suppressed (E, Predicate_Check); | |
7908 | else | |
7909 | return Scope_Suppress.Suppress (Predicate_Check); | |
7910 | end if; | |
7911 | end Predicate_Checks_Suppressed; | |
7912 | ||
ee6ba406 | 7913 | ----------------------------- |
7914 | -- Range_Checks_Suppressed -- | |
7915 | ----------------------------- | |
7916 | ||
7917 | function Range_Checks_Suppressed (E : Entity_Id) return Boolean is | |
7918 | begin | |
9dfe12ae | 7919 | if Present (E) then |
7920 | ||
7921 | -- Note: for now we always suppress range checks on Vax float types, | |
7922 | -- since Gigi does not know how to generate these checks. | |
7923 | ||
7924 | if Vax_Float (E) then | |
7925 | return True; | |
7926 | elsif Kill_Range_Checks (E) then | |
7927 | return True; | |
7928 | elsif Checks_May_Be_Suppressed (E) then | |
7929 | return Is_Check_Suppressed (E, Range_Check); | |
7930 | end if; | |
7931 | end if; | |
ee6ba406 | 7932 | |
fafc6b97 | 7933 | return Scope_Suppress.Suppress (Range_Check); |
ee6ba406 | 7934 | end Range_Checks_Suppressed; |
7935 | ||
0577b0b1 | 7936 | ----------------------------------------- |
7937 | -- Range_Or_Validity_Checks_Suppressed -- | |
7938 | ----------------------------------------- | |
7939 | ||
7940 | -- Note: the coding would be simpler here if we simply made appropriate | |
7941 | -- calls to Range/Validity_Checks_Suppressed, but that would result in | |
7942 | -- duplicated checks which we prefer to avoid. | |
7943 | ||
7944 | function Range_Or_Validity_Checks_Suppressed | |
7945 | (Expr : Node_Id) return Boolean | |
7946 | is | |
7947 | begin | |
7948 | -- Immediate return if scope checks suppressed for either check | |
7949 | ||
fafc6b97 | 7950 | if Scope_Suppress.Suppress (Range_Check) |
7951 | or | |
7952 | Scope_Suppress.Suppress (Validity_Check) | |
7953 | then | |
0577b0b1 | 7954 | return True; |
7955 | end if; | |
7956 | ||
7957 | -- If no expression, that's odd, decide that checks are suppressed, | |
7958 | -- since we don't want anyone trying to do checks in this case, which | |
7959 | -- is most likely the result of some other error. | |
7960 | ||
7961 | if No (Expr) then | |
7962 | return True; | |
7963 | end if; | |
7964 | ||
7965 | -- Expression is present, so perform suppress checks on type | |
7966 | ||
7967 | declare | |
7968 | Typ : constant Entity_Id := Etype (Expr); | |
7969 | begin | |
7970 | if Vax_Float (Typ) then | |
7971 | return True; | |
7972 | elsif Checks_May_Be_Suppressed (Typ) | |
7973 | and then (Is_Check_Suppressed (Typ, Range_Check) | |
7974 | or else | |
7975 | Is_Check_Suppressed (Typ, Validity_Check)) | |
7976 | then | |
7977 | return True; | |
7978 | end if; | |
7979 | end; | |
7980 | ||
7981 | -- If expression is an entity name, perform checks on this entity | |
7982 | ||
7983 | if Is_Entity_Name (Expr) then | |
7984 | declare | |
7985 | Ent : constant Entity_Id := Entity (Expr); | |
7986 | begin | |
7987 | if Checks_May_Be_Suppressed (Ent) then | |
7988 | return Is_Check_Suppressed (Ent, Range_Check) | |
7989 | or else Is_Check_Suppressed (Ent, Validity_Check); | |
7990 | end if; | |
7991 | end; | |
7992 | end if; | |
7993 | ||
7994 | -- If we fall through, no checks suppressed | |
7995 | ||
7996 | return False; | |
7997 | end Range_Or_Validity_Checks_Suppressed; | |
7998 | ||
226494a3 | 7999 | ------------------- |
8000 | -- Remove_Checks -- | |
8001 | ------------------- | |
8002 | ||
8003 | procedure Remove_Checks (Expr : Node_Id) is | |
226494a3 | 8004 | function Process (N : Node_Id) return Traverse_Result; |
8005 | -- Process a single node during the traversal | |
8006 | ||
8f6e4fd5 | 8007 | procedure Traverse is new Traverse_Proc (Process); |
8008 | -- The traversal procedure itself | |
226494a3 | 8009 | |
8010 | ------------- | |
8011 | -- Process -- | |
8012 | ------------- | |
8013 | ||
8014 | function Process (N : Node_Id) return Traverse_Result is | |
8015 | begin | |
8016 | if Nkind (N) not in N_Subexpr then | |
8017 | return Skip; | |
8018 | end if; | |
8019 | ||
8020 | Set_Do_Range_Check (N, False); | |
8021 | ||
8022 | case Nkind (N) is | |
8023 | when N_And_Then => | |
8f6e4fd5 | 8024 | Traverse (Left_Opnd (N)); |
226494a3 | 8025 | return Skip; |
8026 | ||
8027 | when N_Attribute_Reference => | |
226494a3 | 8028 | Set_Do_Overflow_Check (N, False); |
8029 | ||
226494a3 | 8030 | when N_Function_Call => |
8031 | Set_Do_Tag_Check (N, False); | |
8032 | ||
226494a3 | 8033 | when N_Op => |
8034 | Set_Do_Overflow_Check (N, False); | |
8035 | ||
8036 | case Nkind (N) is | |
8037 | when N_Op_Divide => | |
8038 | Set_Do_Division_Check (N, False); | |
8039 | ||
8040 | when N_Op_And => | |
8041 | Set_Do_Length_Check (N, False); | |
8042 | ||
8043 | when N_Op_Mod => | |
8044 | Set_Do_Division_Check (N, False); | |
8045 | ||
8046 | when N_Op_Or => | |
8047 | Set_Do_Length_Check (N, False); | |
8048 | ||
8049 | when N_Op_Rem => | |
8050 | Set_Do_Division_Check (N, False); | |
8051 | ||
8052 | when N_Op_Xor => | |
8053 | Set_Do_Length_Check (N, False); | |
8054 | ||
8055 | when others => | |
8056 | null; | |
8057 | end case; | |
8058 | ||
8059 | when N_Or_Else => | |
8f6e4fd5 | 8060 | Traverse (Left_Opnd (N)); |
226494a3 | 8061 | return Skip; |
8062 | ||
8063 | when N_Selected_Component => | |
226494a3 | 8064 | Set_Do_Discriminant_Check (N, False); |
8065 | ||
226494a3 | 8066 | when N_Type_Conversion => |
9dfe12ae | 8067 | Set_Do_Length_Check (N, False); |
8068 | Set_Do_Tag_Check (N, False); | |
226494a3 | 8069 | Set_Do_Overflow_Check (N, False); |
226494a3 | 8070 | |
8071 | when others => | |
8072 | null; | |
8073 | end case; | |
8074 | ||
8075 | return OK; | |
8076 | end Process; | |
8077 | ||
8078 | -- Start of processing for Remove_Checks | |
8079 | ||
8080 | begin | |
8f6e4fd5 | 8081 | Traverse (Expr); |
226494a3 | 8082 | end Remove_Checks; |
8083 | ||
ee6ba406 | 8084 | ---------------------------- |
8085 | -- Selected_Length_Checks -- | |
8086 | ---------------------------- | |
8087 | ||
8088 | function Selected_Length_Checks | |
8089 | (Ck_Node : Node_Id; | |
8090 | Target_Typ : Entity_Id; | |
8091 | Source_Typ : Entity_Id; | |
314a23b6 | 8092 | Warn_Node : Node_Id) return Check_Result |
ee6ba406 | 8093 | is |
8094 | Loc : constant Source_Ptr := Sloc (Ck_Node); | |
8095 | S_Typ : Entity_Id; | |
8096 | T_Typ : Entity_Id; | |
8097 | Expr_Actual : Node_Id; | |
8098 | Exptyp : Entity_Id; | |
8099 | Cond : Node_Id := Empty; | |
8100 | Do_Access : Boolean := False; | |
8101 | Wnode : Node_Id := Warn_Node; | |
8102 | Ret_Result : Check_Result := (Empty, Empty); | |
8103 | Num_Checks : Natural := 0; | |
8104 | ||
8105 | procedure Add_Check (N : Node_Id); | |
8106 | -- Adds the action given to Ret_Result if N is non-Empty | |
8107 | ||
8108 | function Get_E_Length (E : Entity_Id; Indx : Nat) return Node_Id; | |
8109 | function Get_N_Length (N : Node_Id; Indx : Nat) return Node_Id; | |
314a23b6 | 8110 | -- Comments required ??? |
ee6ba406 | 8111 | |
8112 | function Same_Bounds (L : Node_Id; R : Node_Id) return Boolean; | |
8113 | -- True for equal literals and for nodes that denote the same constant | |
5f260d20 | 8114 | -- entity, even if its value is not a static constant. This includes the |
9dfe12ae | 8115 | -- case of a discriminal reference within an init proc. Removes some |
5f260d20 | 8116 | -- obviously superfluous checks. |
ee6ba406 | 8117 | |
8118 | function Length_E_Cond | |
8119 | (Exptyp : Entity_Id; | |
8120 | Typ : Entity_Id; | |
314a23b6 | 8121 | Indx : Nat) return Node_Id; |
ee6ba406 | 8122 | -- Returns expression to compute: |
8123 | -- Typ'Length /= Exptyp'Length | |
8124 | ||
8125 | function Length_N_Cond | |
8126 | (Expr : Node_Id; | |
8127 | Typ : Entity_Id; | |
314a23b6 | 8128 | Indx : Nat) return Node_Id; |
ee6ba406 | 8129 | -- Returns expression to compute: |
8130 | -- Typ'Length /= Expr'Length | |
8131 | ||
8132 | --------------- | |
8133 | -- Add_Check -- | |
8134 | --------------- | |
8135 | ||
8136 | procedure Add_Check (N : Node_Id) is | |
8137 | begin | |
8138 | if Present (N) then | |
8139 | ||
20cf157b | 8140 | -- For now, ignore attempt to place more than two checks ??? |
8141 | -- This is really worrisome, are we really discarding checks ??? | |
ee6ba406 | 8142 | |
8143 | if Num_Checks = 2 then | |
8144 | return; | |
8145 | end if; | |
8146 | ||
8147 | pragma Assert (Num_Checks <= 1); | |
8148 | Num_Checks := Num_Checks + 1; | |
8149 | Ret_Result (Num_Checks) := N; | |
8150 | end if; | |
8151 | end Add_Check; | |
8152 | ||
8153 | ------------------ | |
8154 | -- Get_E_Length -- | |
8155 | ------------------ | |
8156 | ||
8157 | function Get_E_Length (E : Entity_Id; Indx : Nat) return Node_Id is | |
00c403ee | 8158 | SE : constant Entity_Id := Scope (E); |
ee6ba406 | 8159 | N : Node_Id; |
8160 | E1 : Entity_Id := E; | |
ee6ba406 | 8161 | |
8162 | begin | |
8163 | if Ekind (Scope (E)) = E_Record_Type | |
8164 | and then Has_Discriminants (Scope (E)) | |
8165 | then | |
8166 | N := Build_Discriminal_Subtype_Of_Component (E); | |
8167 | ||
8168 | if Present (N) then | |
8169 | Insert_Action (Ck_Node, N); | |
8170 | E1 := Defining_Identifier (N); | |
8171 | end if; | |
8172 | end if; | |
8173 | ||
8174 | if Ekind (E1) = E_String_Literal_Subtype then | |
8175 | return | |
8176 | Make_Integer_Literal (Loc, | |
8177 | Intval => String_Literal_Length (E1)); | |
8178 | ||
00c403ee | 8179 | elsif SE /= Standard_Standard |
8180 | and then Ekind (Scope (SE)) = E_Protected_Type | |
8181 | and then Has_Discriminants (Scope (SE)) | |
8182 | and then Has_Completion (Scope (SE)) | |
ee6ba406 | 8183 | and then not Inside_Init_Proc |
8184 | then | |
ee6ba406 | 8185 | -- If the type whose length is needed is a private component |
8186 | -- constrained by a discriminant, we must expand the 'Length | |
8187 | -- attribute into an explicit computation, using the discriminal | |
8188 | -- of the current protected operation. This is because the actual | |
8189 | -- type of the prival is constructed after the protected opera- | |
8190 | -- tion has been fully expanded. | |
8191 | ||
8192 | declare | |
8193 | Indx_Type : Node_Id; | |
8194 | Lo : Node_Id; | |
8195 | Hi : Node_Id; | |
8196 | Do_Expand : Boolean := False; | |
8197 | ||
8198 | begin | |
8199 | Indx_Type := First_Index (E); | |
8200 | ||
8201 | for J in 1 .. Indx - 1 loop | |
8202 | Next_Index (Indx_Type); | |
8203 | end loop; | |
8204 | ||
2af58f67 | 8205 | Get_Index_Bounds (Indx_Type, Lo, Hi); |
ee6ba406 | 8206 | |
8207 | if Nkind (Lo) = N_Identifier | |
8208 | and then Ekind (Entity (Lo)) = E_In_Parameter | |
8209 | then | |
8210 | Lo := Get_Discriminal (E, Lo); | |
8211 | Do_Expand := True; | |
8212 | end if; | |
8213 | ||
8214 | if Nkind (Hi) = N_Identifier | |
8215 | and then Ekind (Entity (Hi)) = E_In_Parameter | |
8216 | then | |
8217 | Hi := Get_Discriminal (E, Hi); | |
8218 | Do_Expand := True; | |
8219 | end if; | |
8220 | ||
8221 | if Do_Expand then | |
8222 | if not Is_Entity_Name (Lo) then | |
9dfe12ae | 8223 | Lo := Duplicate_Subexpr_No_Checks (Lo); |
ee6ba406 | 8224 | end if; |
8225 | ||
8226 | if not Is_Entity_Name (Hi) then | |
9dfe12ae | 8227 | Lo := Duplicate_Subexpr_No_Checks (Hi); |
ee6ba406 | 8228 | end if; |
8229 | ||
8230 | N := | |
8231 | Make_Op_Add (Loc, | |
8232 | Left_Opnd => | |
8233 | Make_Op_Subtract (Loc, | |
8234 | Left_Opnd => Hi, | |
8235 | Right_Opnd => Lo), | |
8236 | ||
8237 | Right_Opnd => Make_Integer_Literal (Loc, 1)); | |
8238 | return N; | |
8239 | ||
8240 | else | |
8241 | N := | |
8242 | Make_Attribute_Reference (Loc, | |
8243 | Attribute_Name => Name_Length, | |
8244 | Prefix => | |
8245 | New_Occurrence_Of (E1, Loc)); | |
8246 | ||
8247 | if Indx > 1 then | |
8248 | Set_Expressions (N, New_List ( | |
8249 | Make_Integer_Literal (Loc, Indx))); | |
8250 | end if; | |
8251 | ||
8252 | return N; | |
8253 | end if; | |
8254 | end; | |
8255 | ||
8256 | else | |
8257 | N := | |
8258 | Make_Attribute_Reference (Loc, | |
8259 | Attribute_Name => Name_Length, | |
8260 | Prefix => | |
8261 | New_Occurrence_Of (E1, Loc)); | |
8262 | ||
8263 | if Indx > 1 then | |
8264 | Set_Expressions (N, New_List ( | |
8265 | Make_Integer_Literal (Loc, Indx))); | |
8266 | end if; | |
8267 | ||
8268 | return N; | |
ee6ba406 | 8269 | end if; |
8270 | end Get_E_Length; | |
8271 | ||
8272 | ------------------ | |
8273 | -- Get_N_Length -- | |
8274 | ------------------ | |
8275 | ||
8276 | function Get_N_Length (N : Node_Id; Indx : Nat) return Node_Id is | |
8277 | begin | |
8278 | return | |
8279 | Make_Attribute_Reference (Loc, | |
8280 | Attribute_Name => Name_Length, | |
8281 | Prefix => | |
9dfe12ae | 8282 | Duplicate_Subexpr_No_Checks (N, Name_Req => True), |
ee6ba406 | 8283 | Expressions => New_List ( |
8284 | Make_Integer_Literal (Loc, Indx))); | |
ee6ba406 | 8285 | end Get_N_Length; |
8286 | ||
8287 | ------------------- | |
8288 | -- Length_E_Cond -- | |
8289 | ------------------- | |
8290 | ||
8291 | function Length_E_Cond | |
8292 | (Exptyp : Entity_Id; | |
8293 | Typ : Entity_Id; | |
314a23b6 | 8294 | Indx : Nat) return Node_Id |
ee6ba406 | 8295 | is |
8296 | begin | |
8297 | return | |
8298 | Make_Op_Ne (Loc, | |
8299 | Left_Opnd => Get_E_Length (Typ, Indx), | |
8300 | Right_Opnd => Get_E_Length (Exptyp, Indx)); | |
ee6ba406 | 8301 | end Length_E_Cond; |
8302 | ||
8303 | ------------------- | |
8304 | -- Length_N_Cond -- | |
8305 | ------------------- | |
8306 | ||
8307 | function Length_N_Cond | |
8308 | (Expr : Node_Id; | |
8309 | Typ : Entity_Id; | |
314a23b6 | 8310 | Indx : Nat) return Node_Id |
ee6ba406 | 8311 | is |
8312 | begin | |
8313 | return | |
8314 | Make_Op_Ne (Loc, | |
8315 | Left_Opnd => Get_E_Length (Typ, Indx), | |
8316 | Right_Opnd => Get_N_Length (Expr, Indx)); | |
ee6ba406 | 8317 | end Length_N_Cond; |
8318 | ||
feff2f05 | 8319 | ----------------- |
8320 | -- Same_Bounds -- | |
8321 | ----------------- | |
8322 | ||
ee6ba406 | 8323 | function Same_Bounds (L : Node_Id; R : Node_Id) return Boolean is |
8324 | begin | |
8325 | return | |
8326 | (Nkind (L) = N_Integer_Literal | |
8327 | and then Nkind (R) = N_Integer_Literal | |
8328 | and then Intval (L) = Intval (R)) | |
8329 | ||
8330 | or else | |
8331 | (Is_Entity_Name (L) | |
8332 | and then Ekind (Entity (L)) = E_Constant | |
8333 | and then ((Is_Entity_Name (R) | |
8334 | and then Entity (L) = Entity (R)) | |
8335 | or else | |
8336 | (Nkind (R) = N_Type_Conversion | |
8337 | and then Is_Entity_Name (Expression (R)) | |
8338 | and then Entity (L) = Entity (Expression (R))))) | |
8339 | ||
8340 | or else | |
8341 | (Is_Entity_Name (R) | |
8342 | and then Ekind (Entity (R)) = E_Constant | |
8343 | and then Nkind (L) = N_Type_Conversion | |
8344 | and then Is_Entity_Name (Expression (L)) | |
5f260d20 | 8345 | and then Entity (R) = Entity (Expression (L))) |
8346 | ||
8347 | or else | |
8348 | (Is_Entity_Name (L) | |
8349 | and then Is_Entity_Name (R) | |
8350 | and then Entity (L) = Entity (R) | |
8351 | and then Ekind (Entity (L)) = E_In_Parameter | |
8352 | and then Inside_Init_Proc); | |
ee6ba406 | 8353 | end Same_Bounds; |
8354 | ||
8355 | -- Start of processing for Selected_Length_Checks | |
8356 | ||
8357 | begin | |
a33565dd | 8358 | if not Expander_Active then |
ee6ba406 | 8359 | return Ret_Result; |
8360 | end if; | |
8361 | ||
8362 | if Target_Typ = Any_Type | |
8363 | or else Target_Typ = Any_Composite | |
8364 | or else Raises_Constraint_Error (Ck_Node) | |
8365 | then | |
8366 | return Ret_Result; | |
8367 | end if; | |
8368 | ||
8369 | if No (Wnode) then | |
8370 | Wnode := Ck_Node; | |
8371 | end if; | |
8372 | ||
8373 | T_Typ := Target_Typ; | |
8374 | ||
8375 | if No (Source_Typ) then | |
8376 | S_Typ := Etype (Ck_Node); | |
8377 | else | |
8378 | S_Typ := Source_Typ; | |
8379 | end if; | |
8380 | ||
8381 | if S_Typ = Any_Type or else S_Typ = Any_Composite then | |
8382 | return Ret_Result; | |
8383 | end if; | |
8384 | ||
8385 | if Is_Access_Type (T_Typ) and then Is_Access_Type (S_Typ) then | |
8386 | S_Typ := Designated_Type (S_Typ); | |
8387 | T_Typ := Designated_Type (T_Typ); | |
8388 | Do_Access := True; | |
8389 | ||
2af58f67 | 8390 | -- A simple optimization for the null case |
ee6ba406 | 8391 | |
2af58f67 | 8392 | if Known_Null (Ck_Node) then |
ee6ba406 | 8393 | return Ret_Result; |
8394 | end if; | |
8395 | end if; | |
8396 | ||
8397 | if Is_Array_Type (T_Typ) and then Is_Array_Type (S_Typ) then | |
8398 | if Is_Constrained (T_Typ) then | |
8399 | ||
92f1631f | 8400 | -- The checking code to be generated will freeze the corresponding |
8401 | -- array type. However, we must freeze the type now, so that the | |
8402 | -- freeze node does not appear within the generated if expression, | |
8403 | -- but ahead of it. | |
ee6ba406 | 8404 | |
8405 | Freeze_Before (Ck_Node, T_Typ); | |
8406 | ||
8407 | Expr_Actual := Get_Referenced_Object (Ck_Node); | |
84d0d4a5 | 8408 | Exptyp := Get_Actual_Subtype (Ck_Node); |
ee6ba406 | 8409 | |
8410 | if Is_Access_Type (Exptyp) then | |
8411 | Exptyp := Designated_Type (Exptyp); | |
8412 | end if; | |
8413 | ||
8414 | -- String_Literal case. This needs to be handled specially be- | |
8415 | -- cause no index types are available for string literals. The | |
8416 | -- condition is simply: | |
8417 | ||
8418 | -- T_Typ'Length = string-literal-length | |
8419 | ||
9dfe12ae | 8420 | if Nkind (Expr_Actual) = N_String_Literal |
8421 | and then Ekind (Etype (Expr_Actual)) = E_String_Literal_Subtype | |
8422 | then | |
ee6ba406 | 8423 | Cond := |
8424 | Make_Op_Ne (Loc, | |
8425 | Left_Opnd => Get_E_Length (T_Typ, 1), | |
8426 | Right_Opnd => | |
8427 | Make_Integer_Literal (Loc, | |
8428 | Intval => | |
8429 | String_Literal_Length (Etype (Expr_Actual)))); | |
8430 | ||
8431 | -- General array case. Here we have a usable actual subtype for | |
8432 | -- the expression, and the condition is built from the two types | |
8433 | -- (Do_Length): | |
8434 | ||
8435 | -- T_Typ'Length /= Exptyp'Length or else | |
8436 | -- T_Typ'Length (2) /= Exptyp'Length (2) or else | |
8437 | -- T_Typ'Length (3) /= Exptyp'Length (3) or else | |
8438 | -- ... | |
8439 | ||
8440 | elsif Is_Constrained (Exptyp) then | |
8441 | declare | |
9dfe12ae | 8442 | Ndims : constant Nat := Number_Dimensions (T_Typ); |
8443 | ||
8444 | L_Index : Node_Id; | |
8445 | R_Index : Node_Id; | |
8446 | L_Low : Node_Id; | |
8447 | L_High : Node_Id; | |
8448 | R_Low : Node_Id; | |
8449 | R_High : Node_Id; | |
ee6ba406 | 8450 | L_Length : Uint; |
8451 | R_Length : Uint; | |
9dfe12ae | 8452 | Ref_Node : Node_Id; |
ee6ba406 | 8453 | |
8454 | begin | |
feff2f05 | 8455 | -- At the library level, we need to ensure that the type of |
8456 | -- the object is elaborated before the check itself is | |
8457 | -- emitted. This is only done if the object is in the | |
8458 | -- current compilation unit, otherwise the type is frozen | |
8459 | -- and elaborated in its unit. | |
9dfe12ae | 8460 | |
8461 | if Is_Itype (Exptyp) | |
8462 | and then | |
8463 | Ekind (Cunit_Entity (Current_Sem_Unit)) = E_Package | |
8464 | and then | |
8465 | not In_Package_Body (Cunit_Entity (Current_Sem_Unit)) | |
d66aa9f6 | 8466 | and then In_Open_Scopes (Scope (Exptyp)) |
9dfe12ae | 8467 | then |
8468 | Ref_Node := Make_Itype_Reference (Sloc (Ck_Node)); | |
8469 | Set_Itype (Ref_Node, Exptyp); | |
8470 | Insert_Action (Ck_Node, Ref_Node); | |
8471 | end if; | |
8472 | ||
ee6ba406 | 8473 | L_Index := First_Index (T_Typ); |
8474 | R_Index := First_Index (Exptyp); | |
8475 | ||
8476 | for Indx in 1 .. Ndims loop | |
8477 | if not (Nkind (L_Index) = N_Raise_Constraint_Error | |
f15731c4 | 8478 | or else |
8479 | Nkind (R_Index) = N_Raise_Constraint_Error) | |
ee6ba406 | 8480 | then |
8481 | Get_Index_Bounds (L_Index, L_Low, L_High); | |
8482 | Get_Index_Bounds (R_Index, R_Low, R_High); | |
8483 | ||
8484 | -- Deal with compile time length check. Note that we | |
8485 | -- skip this in the access case, because the access | |
8486 | -- value may be null, so we cannot know statically. | |
8487 | ||
8488 | if not Do_Access | |
8489 | and then Compile_Time_Known_Value (L_Low) | |
8490 | and then Compile_Time_Known_Value (L_High) | |
8491 | and then Compile_Time_Known_Value (R_Low) | |
8492 | and then Compile_Time_Known_Value (R_High) | |
8493 | then | |
8494 | if Expr_Value (L_High) >= Expr_Value (L_Low) then | |
8495 | L_Length := Expr_Value (L_High) - | |
8496 | Expr_Value (L_Low) + 1; | |
8497 | else | |
8498 | L_Length := UI_From_Int (0); | |
8499 | end if; | |
8500 | ||
8501 | if Expr_Value (R_High) >= Expr_Value (R_Low) then | |
8502 | R_Length := Expr_Value (R_High) - | |
8503 | Expr_Value (R_Low) + 1; | |
8504 | else | |
8505 | R_Length := UI_From_Int (0); | |
8506 | end if; | |
8507 | ||
8508 | if L_Length > R_Length then | |
8509 | Add_Check | |
8510 | (Compile_Time_Constraint_Error | |
cb97ae5c | 8511 | (Wnode, "too few elements for}??", T_Typ)); |
ee6ba406 | 8512 | |
8513 | elsif L_Length < R_Length then | |
8514 | Add_Check | |
8515 | (Compile_Time_Constraint_Error | |
cb97ae5c | 8516 | (Wnode, "too many elements for}??", T_Typ)); |
ee6ba406 | 8517 | end if; |
8518 | ||
8519 | -- The comparison for an individual index subtype | |
8520 | -- is omitted if the corresponding index subtypes | |
8521 | -- statically match, since the result is known to | |
8522 | -- be true. Note that this test is worth while even | |
8523 | -- though we do static evaluation, because non-static | |
8524 | -- subtypes can statically match. | |
8525 | ||
8526 | elsif not | |
8527 | Subtypes_Statically_Match | |
8528 | (Etype (L_Index), Etype (R_Index)) | |
8529 | ||
8530 | and then not | |
8531 | (Same_Bounds (L_Low, R_Low) | |
8532 | and then Same_Bounds (L_High, R_High)) | |
8533 | then | |
8534 | Evolve_Or_Else | |
8535 | (Cond, Length_E_Cond (Exptyp, T_Typ, Indx)); | |
8536 | end if; | |
8537 | ||
8538 | Next (L_Index); | |
8539 | Next (R_Index); | |
8540 | end if; | |
8541 | end loop; | |
8542 | end; | |
8543 | ||
8544 | -- Handle cases where we do not get a usable actual subtype that | |
8545 | -- is constrained. This happens for example in the function call | |
8546 | -- and explicit dereference cases. In these cases, we have to get | |
8547 | -- the length or range from the expression itself, making sure we | |
8548 | -- do not evaluate it more than once. | |
8549 | ||
8550 | -- Here Ck_Node is the original expression, or more properly the | |
feff2f05 | 8551 | -- result of applying Duplicate_Expr to the original tree, forcing |
8552 | -- the result to be a name. | |
ee6ba406 | 8553 | |
8554 | else | |
8555 | declare | |
9dfe12ae | 8556 | Ndims : constant Nat := Number_Dimensions (T_Typ); |
ee6ba406 | 8557 | |
8558 | begin | |
8559 | -- Build the condition for the explicit dereference case | |
8560 | ||
8561 | for Indx in 1 .. Ndims loop | |
8562 | Evolve_Or_Else | |
8563 | (Cond, Length_N_Cond (Ck_Node, T_Typ, Indx)); | |
8564 | end loop; | |
8565 | end; | |
8566 | end if; | |
8567 | end if; | |
8568 | end if; | |
8569 | ||
8570 | -- Construct the test and insert into the tree | |
8571 | ||
8572 | if Present (Cond) then | |
8573 | if Do_Access then | |
8574 | Cond := Guard_Access (Cond, Loc, Ck_Node); | |
8575 | end if; | |
8576 | ||
f15731c4 | 8577 | Add_Check |
8578 | (Make_Raise_Constraint_Error (Loc, | |
8579 | Condition => Cond, | |
8580 | Reason => CE_Length_Check_Failed)); | |
ee6ba406 | 8581 | end if; |
8582 | ||
8583 | return Ret_Result; | |
ee6ba406 | 8584 | end Selected_Length_Checks; |
8585 | ||
8586 | --------------------------- | |
8587 | -- Selected_Range_Checks -- | |
8588 | --------------------------- | |
8589 | ||
8590 | function Selected_Range_Checks | |
8591 | (Ck_Node : Node_Id; | |
8592 | Target_Typ : Entity_Id; | |
8593 | Source_Typ : Entity_Id; | |
314a23b6 | 8594 | Warn_Node : Node_Id) return Check_Result |
ee6ba406 | 8595 | is |
8596 | Loc : constant Source_Ptr := Sloc (Ck_Node); | |
8597 | S_Typ : Entity_Id; | |
8598 | T_Typ : Entity_Id; | |
8599 | Expr_Actual : Node_Id; | |
8600 | Exptyp : Entity_Id; | |
8601 | Cond : Node_Id := Empty; | |
8602 | Do_Access : Boolean := False; | |
8603 | Wnode : Node_Id := Warn_Node; | |
8604 | Ret_Result : Check_Result := (Empty, Empty); | |
8605 | Num_Checks : Integer := 0; | |
8606 | ||
8607 | procedure Add_Check (N : Node_Id); | |
8608 | -- Adds the action given to Ret_Result if N is non-Empty | |
8609 | ||
8610 | function Discrete_Range_Cond | |
8611 | (Expr : Node_Id; | |
314a23b6 | 8612 | Typ : Entity_Id) return Node_Id; |
ee6ba406 | 8613 | -- Returns expression to compute: |
8614 | -- Low_Bound (Expr) < Typ'First | |
8615 | -- or else | |
8616 | -- High_Bound (Expr) > Typ'Last | |
8617 | ||
8618 | function Discrete_Expr_Cond | |
8619 | (Expr : Node_Id; | |
314a23b6 | 8620 | Typ : Entity_Id) return Node_Id; |
ee6ba406 | 8621 | -- Returns expression to compute: |
8622 | -- Expr < Typ'First | |
8623 | -- or else | |
8624 | -- Expr > Typ'Last | |
8625 | ||
8626 | function Get_E_First_Or_Last | |
3cb12758 | 8627 | (Loc : Source_Ptr; |
8628 | E : Entity_Id; | |
ee6ba406 | 8629 | Indx : Nat; |
314a23b6 | 8630 | Nam : Name_Id) return Node_Id; |
79212397 | 8631 | -- Returns an attribute reference |
ee6ba406 | 8632 | -- E'First or E'Last |
79212397 | 8633 | -- with a source location of Loc. |
f73ee678 | 8634 | -- |
79212397 | 8635 | -- Nam is Name_First or Name_Last, according to which attribute is |
8636 | -- desired. If Indx is non-zero, it is passed as a literal in the | |
8637 | -- Expressions of the attribute reference (identifying the desired | |
8638 | -- array dimension). | |
ee6ba406 | 8639 | |
8640 | function Get_N_First (N : Node_Id; Indx : Nat) return Node_Id; | |
8641 | function Get_N_Last (N : Node_Id; Indx : Nat) return Node_Id; | |
8642 | -- Returns expression to compute: | |
9dfe12ae | 8643 | -- N'First or N'Last using Duplicate_Subexpr_No_Checks |
ee6ba406 | 8644 | |
8645 | function Range_E_Cond | |
8646 | (Exptyp : Entity_Id; | |
8647 | Typ : Entity_Id; | |
8648 | Indx : Nat) | |
8649 | return Node_Id; | |
8650 | -- Returns expression to compute: | |
8651 | -- Exptyp'First < Typ'First or else Exptyp'Last > Typ'Last | |
8652 | ||
8653 | function Range_Equal_E_Cond | |
8654 | (Exptyp : Entity_Id; | |
8655 | Typ : Entity_Id; | |
314a23b6 | 8656 | Indx : Nat) return Node_Id; |
ee6ba406 | 8657 | -- Returns expression to compute: |
8658 | -- Exptyp'First /= Typ'First or else Exptyp'Last /= Typ'Last | |
8659 | ||
8660 | function Range_N_Cond | |
8661 | (Expr : Node_Id; | |
8662 | Typ : Entity_Id; | |
314a23b6 | 8663 | Indx : Nat) return Node_Id; |
ee6ba406 | 8664 | -- Return expression to compute: |
8665 | -- Expr'First < Typ'First or else Expr'Last > Typ'Last | |
8666 | ||
8667 | --------------- | |
8668 | -- Add_Check -- | |
8669 | --------------- | |
8670 | ||
8671 | procedure Add_Check (N : Node_Id) is | |
8672 | begin | |
8673 | if Present (N) then | |
8674 | ||
8675 | -- For now, ignore attempt to place more than 2 checks ??? | |
8676 | ||
8677 | if Num_Checks = 2 then | |
8678 | return; | |
8679 | end if; | |
8680 | ||
8681 | pragma Assert (Num_Checks <= 1); | |
8682 | Num_Checks := Num_Checks + 1; | |
8683 | Ret_Result (Num_Checks) := N; | |
8684 | end if; | |
8685 | end Add_Check; | |
8686 | ||
8687 | ------------------------- | |
8688 | -- Discrete_Expr_Cond -- | |
8689 | ------------------------- | |
8690 | ||
8691 | function Discrete_Expr_Cond | |
8692 | (Expr : Node_Id; | |
314a23b6 | 8693 | Typ : Entity_Id) return Node_Id |
ee6ba406 | 8694 | is |
8695 | begin | |
8696 | return | |
8697 | Make_Or_Else (Loc, | |
8698 | Left_Opnd => | |
8699 | Make_Op_Lt (Loc, | |
8700 | Left_Opnd => | |
9dfe12ae | 8701 | Convert_To (Base_Type (Typ), |
8702 | Duplicate_Subexpr_No_Checks (Expr)), | |
ee6ba406 | 8703 | Right_Opnd => |
8704 | Convert_To (Base_Type (Typ), | |
3cb12758 | 8705 | Get_E_First_Or_Last (Loc, Typ, 0, Name_First))), |
ee6ba406 | 8706 | |
8707 | Right_Opnd => | |
8708 | Make_Op_Gt (Loc, | |
8709 | Left_Opnd => | |
9dfe12ae | 8710 | Convert_To (Base_Type (Typ), |
8711 | Duplicate_Subexpr_No_Checks (Expr)), | |
ee6ba406 | 8712 | Right_Opnd => |
8713 | Convert_To | |
8714 | (Base_Type (Typ), | |
3cb12758 | 8715 | Get_E_First_Or_Last (Loc, Typ, 0, Name_Last)))); |
ee6ba406 | 8716 | end Discrete_Expr_Cond; |
8717 | ||
8718 | ------------------------- | |
8719 | -- Discrete_Range_Cond -- | |
8720 | ------------------------- | |
8721 | ||
8722 | function Discrete_Range_Cond | |
8723 | (Expr : Node_Id; | |
314a23b6 | 8724 | Typ : Entity_Id) return Node_Id |
ee6ba406 | 8725 | is |
8726 | LB : Node_Id := Low_Bound (Expr); | |
8727 | HB : Node_Id := High_Bound (Expr); | |
8728 | ||
8729 | Left_Opnd : Node_Id; | |
8730 | Right_Opnd : Node_Id; | |
8731 | ||
8732 | begin | |
8733 | if Nkind (LB) = N_Identifier | |
feff2f05 | 8734 | and then Ekind (Entity (LB)) = E_Discriminant |
8735 | then | |
ee6ba406 | 8736 | LB := New_Occurrence_Of (Discriminal (Entity (LB)), Loc); |
8737 | end if; | |
8738 | ||
ee6ba406 | 8739 | Left_Opnd := |
8740 | Make_Op_Lt (Loc, | |
8741 | Left_Opnd => | |
8742 | Convert_To | |
9dfe12ae | 8743 | (Base_Type (Typ), Duplicate_Subexpr_No_Checks (LB)), |
ee6ba406 | 8744 | |
8745 | Right_Opnd => | |
8746 | Convert_To | |
3cb12758 | 8747 | (Base_Type (Typ), |
8748 | Get_E_First_Or_Last (Loc, Typ, 0, Name_First))); | |
ee6ba406 | 8749 | |
ba9b1a39 | 8750 | if Nkind (HB) = N_Identifier |
8751 | and then Ekind (Entity (HB)) = E_Discriminant | |
ee6ba406 | 8752 | then |
ba9b1a39 | 8753 | HB := New_Occurrence_Of (Discriminal (Entity (HB)), Loc); |
ee6ba406 | 8754 | end if; |
8755 | ||
8756 | Right_Opnd := | |
8757 | Make_Op_Gt (Loc, | |
8758 | Left_Opnd => | |
8759 | Convert_To | |
9dfe12ae | 8760 | (Base_Type (Typ), Duplicate_Subexpr_No_Checks (HB)), |
ee6ba406 | 8761 | |
8762 | Right_Opnd => | |
8763 | Convert_To | |
8764 | (Base_Type (Typ), | |
3cb12758 | 8765 | Get_E_First_Or_Last (Loc, Typ, 0, Name_Last))); |
ee6ba406 | 8766 | |
8767 | return Make_Or_Else (Loc, Left_Opnd, Right_Opnd); | |
8768 | end Discrete_Range_Cond; | |
8769 | ||
8770 | ------------------------- | |
8771 | -- Get_E_First_Or_Last -- | |
8772 | ------------------------- | |
8773 | ||
8774 | function Get_E_First_Or_Last | |
3cb12758 | 8775 | (Loc : Source_Ptr; |
8776 | E : Entity_Id; | |
ee6ba406 | 8777 | Indx : Nat; |
314a23b6 | 8778 | Nam : Name_Id) return Node_Id |
ee6ba406 | 8779 | is |
3cb12758 | 8780 | Exprs : List_Id; |
ee6ba406 | 8781 | begin |
3cb12758 | 8782 | if Indx > 0 then |
8783 | Exprs := New_List (Make_Integer_Literal (Loc, UI_From_Int (Indx))); | |
ee6ba406 | 8784 | else |
3cb12758 | 8785 | Exprs := No_List; |
ee6ba406 | 8786 | end if; |
8787 | ||
3cb12758 | 8788 | return Make_Attribute_Reference (Loc, |
8789 | Prefix => New_Occurrence_Of (E, Loc), | |
8790 | Attribute_Name => Nam, | |
8791 | Expressions => Exprs); | |
ee6ba406 | 8792 | end Get_E_First_Or_Last; |
8793 | ||
8794 | ----------------- | |
8795 | -- Get_N_First -- | |
8796 | ----------------- | |
8797 | ||
8798 | function Get_N_First (N : Node_Id; Indx : Nat) return Node_Id is | |
8799 | begin | |
8800 | return | |
8801 | Make_Attribute_Reference (Loc, | |
8802 | Attribute_Name => Name_First, | |
8803 | Prefix => | |
9dfe12ae | 8804 | Duplicate_Subexpr_No_Checks (N, Name_Req => True), |
ee6ba406 | 8805 | Expressions => New_List ( |
8806 | Make_Integer_Literal (Loc, Indx))); | |
ee6ba406 | 8807 | end Get_N_First; |
8808 | ||
8809 | ---------------- | |
8810 | -- Get_N_Last -- | |
8811 | ---------------- | |
8812 | ||
8813 | function Get_N_Last (N : Node_Id; Indx : Nat) return Node_Id is | |
8814 | begin | |
8815 | return | |
8816 | Make_Attribute_Reference (Loc, | |
8817 | Attribute_Name => Name_Last, | |
8818 | Prefix => | |
9dfe12ae | 8819 | Duplicate_Subexpr_No_Checks (N, Name_Req => True), |
ee6ba406 | 8820 | Expressions => New_List ( |
8821 | Make_Integer_Literal (Loc, Indx))); | |
ee6ba406 | 8822 | end Get_N_Last; |
8823 | ||
8824 | ------------------ | |
8825 | -- Range_E_Cond -- | |
8826 | ------------------ | |
8827 | ||
8828 | function Range_E_Cond | |
8829 | (Exptyp : Entity_Id; | |
8830 | Typ : Entity_Id; | |
314a23b6 | 8831 | Indx : Nat) return Node_Id |
ee6ba406 | 8832 | is |
8833 | begin | |
8834 | return | |
8835 | Make_Or_Else (Loc, | |
8836 | Left_Opnd => | |
8837 | Make_Op_Lt (Loc, | |
3cb12758 | 8838 | Left_Opnd => |
8839 | Get_E_First_Or_Last (Loc, Exptyp, Indx, Name_First), | |
8840 | Right_Opnd => | |
8841 | Get_E_First_Or_Last (Loc, Typ, Indx, Name_First)), | |
ee6ba406 | 8842 | |
8843 | Right_Opnd => | |
8844 | Make_Op_Gt (Loc, | |
3cb12758 | 8845 | Left_Opnd => |
8846 | Get_E_First_Or_Last (Loc, Exptyp, Indx, Name_Last), | |
8847 | Right_Opnd => | |
8848 | Get_E_First_Or_Last (Loc, Typ, Indx, Name_Last))); | |
ee6ba406 | 8849 | end Range_E_Cond; |
8850 | ||
8851 | ------------------------ | |
8852 | -- Range_Equal_E_Cond -- | |
8853 | ------------------------ | |
8854 | ||
8855 | function Range_Equal_E_Cond | |
8856 | (Exptyp : Entity_Id; | |
8857 | Typ : Entity_Id; | |
314a23b6 | 8858 | Indx : Nat) return Node_Id |
ee6ba406 | 8859 | is |
8860 | begin | |
8861 | return | |
8862 | Make_Or_Else (Loc, | |
8863 | Left_Opnd => | |
8864 | Make_Op_Ne (Loc, | |
3cb12758 | 8865 | Left_Opnd => |
8866 | Get_E_First_Or_Last (Loc, Exptyp, Indx, Name_First), | |
8867 | Right_Opnd => | |
8868 | Get_E_First_Or_Last (Loc, Typ, Indx, Name_First)), | |
8869 | ||
ee6ba406 | 8870 | Right_Opnd => |
8871 | Make_Op_Ne (Loc, | |
3cb12758 | 8872 | Left_Opnd => |
8873 | Get_E_First_Or_Last (Loc, Exptyp, Indx, Name_Last), | |
8874 | Right_Opnd => | |
8875 | Get_E_First_Or_Last (Loc, Typ, Indx, Name_Last))); | |
ee6ba406 | 8876 | end Range_Equal_E_Cond; |
8877 | ||
8878 | ------------------ | |
8879 | -- Range_N_Cond -- | |
8880 | ------------------ | |
8881 | ||
8882 | function Range_N_Cond | |
8883 | (Expr : Node_Id; | |
8884 | Typ : Entity_Id; | |
314a23b6 | 8885 | Indx : Nat) return Node_Id |
ee6ba406 | 8886 | is |
8887 | begin | |
8888 | return | |
8889 | Make_Or_Else (Loc, | |
8890 | Left_Opnd => | |
8891 | Make_Op_Lt (Loc, | |
3cb12758 | 8892 | Left_Opnd => |
8893 | Get_N_First (Expr, Indx), | |
8894 | Right_Opnd => | |
8895 | Get_E_First_Or_Last (Loc, Typ, Indx, Name_First)), | |
ee6ba406 | 8896 | |
8897 | Right_Opnd => | |
8898 | Make_Op_Gt (Loc, | |
3cb12758 | 8899 | Left_Opnd => |
8900 | Get_N_Last (Expr, Indx), | |
8901 | Right_Opnd => | |
8902 | Get_E_First_Or_Last (Loc, Typ, Indx, Name_Last))); | |
ee6ba406 | 8903 | end Range_N_Cond; |
8904 | ||
8905 | -- Start of processing for Selected_Range_Checks | |
8906 | ||
8907 | begin | |
a33565dd | 8908 | if not Expander_Active then |
ee6ba406 | 8909 | return Ret_Result; |
8910 | end if; | |
8911 | ||
8912 | if Target_Typ = Any_Type | |
8913 | or else Target_Typ = Any_Composite | |
8914 | or else Raises_Constraint_Error (Ck_Node) | |
8915 | then | |
8916 | return Ret_Result; | |
8917 | end if; | |
8918 | ||
8919 | if No (Wnode) then | |
8920 | Wnode := Ck_Node; | |
8921 | end if; | |
8922 | ||
8923 | T_Typ := Target_Typ; | |
8924 | ||
8925 | if No (Source_Typ) then | |
8926 | S_Typ := Etype (Ck_Node); | |
8927 | else | |
8928 | S_Typ := Source_Typ; | |
8929 | end if; | |
8930 | ||
8931 | if S_Typ = Any_Type or else S_Typ = Any_Composite then | |
8932 | return Ret_Result; | |
8933 | end if; | |
8934 | ||
8935 | -- The order of evaluating T_Typ before S_Typ seems to be critical | |
8936 | -- because S_Typ can be derived from Etype (Ck_Node), if it's not passed | |
8937 | -- in, and since Node can be an N_Range node, it might be invalid. | |
8938 | -- Should there be an assert check somewhere for taking the Etype of | |
8939 | -- an N_Range node ??? | |
8940 | ||
8941 | if Is_Access_Type (T_Typ) and then Is_Access_Type (S_Typ) then | |
8942 | S_Typ := Designated_Type (S_Typ); | |
8943 | T_Typ := Designated_Type (T_Typ); | |
8944 | Do_Access := True; | |
8945 | ||
2af58f67 | 8946 | -- A simple optimization for the null case |
ee6ba406 | 8947 | |
2af58f67 | 8948 | if Known_Null (Ck_Node) then |
ee6ba406 | 8949 | return Ret_Result; |
8950 | end if; | |
8951 | end if; | |
8952 | ||
8953 | -- For an N_Range Node, check for a null range and then if not | |
8954 | -- null generate a range check action. | |
8955 | ||
8956 | if Nkind (Ck_Node) = N_Range then | |
8957 | ||
8958 | -- There's no point in checking a range against itself | |
8959 | ||
8960 | if Ck_Node = Scalar_Range (T_Typ) then | |
8961 | return Ret_Result; | |
8962 | end if; | |
8963 | ||
8964 | declare | |
8965 | T_LB : constant Node_Id := Type_Low_Bound (T_Typ); | |
8966 | T_HB : constant Node_Id := Type_High_Bound (T_Typ); | |
eefa141b | 8967 | Known_T_LB : constant Boolean := Compile_Time_Known_Value (T_LB); |
8968 | Known_T_HB : constant Boolean := Compile_Time_Known_Value (T_HB); | |
ee6ba406 | 8969 | |
eefa141b | 8970 | LB : Node_Id := Low_Bound (Ck_Node); |
8971 | HB : Node_Id := High_Bound (Ck_Node); | |
8972 | Known_LB : Boolean; | |
8973 | Known_HB : Boolean; | |
8974 | ||
8975 | Null_Range : Boolean; | |
ee6ba406 | 8976 | Out_Of_Range_L : Boolean; |
8977 | Out_Of_Range_H : Boolean; | |
8978 | ||
8979 | begin | |
eefa141b | 8980 | -- Compute what is known at compile time |
8981 | ||
8982 | if Known_T_LB and Known_T_HB then | |
8983 | if Compile_Time_Known_Value (LB) then | |
8984 | Known_LB := True; | |
8985 | ||
8986 | -- There's no point in checking that a bound is within its | |
8987 | -- own range so pretend that it is known in this case. First | |
8988 | -- deal with low bound. | |
8989 | ||
8990 | elsif Ekind (Etype (LB)) = E_Signed_Integer_Subtype | |
8991 | and then Scalar_Range (Etype (LB)) = Scalar_Range (T_Typ) | |
8992 | then | |
8993 | LB := T_LB; | |
8994 | Known_LB := True; | |
8995 | ||
8996 | else | |
8997 | Known_LB := False; | |
8998 | end if; | |
8999 | ||
9000 | -- Likewise for the high bound | |
9001 | ||
9002 | if Compile_Time_Known_Value (HB) then | |
9003 | Known_HB := True; | |
9004 | ||
9005 | elsif Ekind (Etype (HB)) = E_Signed_Integer_Subtype | |
9006 | and then Scalar_Range (Etype (HB)) = Scalar_Range (T_Typ) | |
9007 | then | |
9008 | HB := T_HB; | |
9009 | Known_HB := True; | |
eefa141b | 9010 | else |
9011 | Known_HB := False; | |
9012 | end if; | |
9013 | end if; | |
9014 | ||
9015 | -- Check for case where everything is static and we can do the | |
9016 | -- check at compile time. This is skipped if we have an access | |
9017 | -- type, since the access value may be null. | |
9018 | ||
9019 | -- ??? This code can be improved since you only need to know that | |
9020 | -- the two respective bounds (LB & T_LB or HB & T_HB) are known at | |
9021 | -- compile time to emit pertinent messages. | |
9022 | ||
9023 | if Known_T_LB and Known_T_HB and Known_LB and Known_HB | |
9024 | and not Do_Access | |
ee6ba406 | 9025 | then |
9026 | -- Floating-point case | |
9027 | ||
9028 | if Is_Floating_Point_Type (S_Typ) then | |
9029 | Null_Range := Expr_Value_R (HB) < Expr_Value_R (LB); | |
9030 | Out_Of_Range_L := | |
9031 | (Expr_Value_R (LB) < Expr_Value_R (T_LB)) | |
eefa141b | 9032 | or else |
ee6ba406 | 9033 | (Expr_Value_R (LB) > Expr_Value_R (T_HB)); |
9034 | ||
9035 | Out_Of_Range_H := | |
9036 | (Expr_Value_R (HB) > Expr_Value_R (T_HB)) | |
eefa141b | 9037 | or else |
ee6ba406 | 9038 | (Expr_Value_R (HB) < Expr_Value_R (T_LB)); |
9039 | ||
9040 | -- Fixed or discrete type case | |
9041 | ||
9042 | else | |
9043 | Null_Range := Expr_Value (HB) < Expr_Value (LB); | |
9044 | Out_Of_Range_L := | |
9045 | (Expr_Value (LB) < Expr_Value (T_LB)) | |
eefa141b | 9046 | or else |
ee6ba406 | 9047 | (Expr_Value (LB) > Expr_Value (T_HB)); |
9048 | ||
9049 | Out_Of_Range_H := | |
9050 | (Expr_Value (HB) > Expr_Value (T_HB)) | |
eefa141b | 9051 | or else |
ee6ba406 | 9052 | (Expr_Value (HB) < Expr_Value (T_LB)); |
9053 | end if; | |
9054 | ||
9055 | if not Null_Range then | |
9056 | if Out_Of_Range_L then | |
9057 | if No (Warn_Node) then | |
9058 | Add_Check | |
9059 | (Compile_Time_Constraint_Error | |
9060 | (Low_Bound (Ck_Node), | |
cb97ae5c | 9061 | "static value out of range of}??", T_Typ)); |
ee6ba406 | 9062 | |
9063 | else | |
9064 | Add_Check | |
9065 | (Compile_Time_Constraint_Error | |
9066 | (Wnode, | |
cb97ae5c | 9067 | "static range out of bounds of}??", T_Typ)); |
ee6ba406 | 9068 | end if; |
9069 | end if; | |
9070 | ||
9071 | if Out_Of_Range_H then | |
9072 | if No (Warn_Node) then | |
9073 | Add_Check | |
9074 | (Compile_Time_Constraint_Error | |
9075 | (High_Bound (Ck_Node), | |
cb97ae5c | 9076 | "static value out of range of}??", T_Typ)); |
ee6ba406 | 9077 | |
9078 | else | |
9079 | Add_Check | |
9080 | (Compile_Time_Constraint_Error | |
9081 | (Wnode, | |
cb97ae5c | 9082 | "static range out of bounds of}??", T_Typ)); |
ee6ba406 | 9083 | end if; |
9084 | end if; | |
ee6ba406 | 9085 | end if; |
9086 | ||
9087 | else | |
9088 | declare | |
9089 | LB : Node_Id := Low_Bound (Ck_Node); | |
9090 | HB : Node_Id := High_Bound (Ck_Node); | |
9091 | ||
9092 | begin | |
feff2f05 | 9093 | -- If either bound is a discriminant and we are within the |
9094 | -- record declaration, it is a use of the discriminant in a | |
9095 | -- constraint of a component, and nothing can be checked | |
9096 | -- here. The check will be emitted within the init proc. | |
9097 | -- Before then, the discriminal has no real meaning. | |
9098 | -- Similarly, if the entity is a discriminal, there is no | |
9099 | -- check to perform yet. | |
9100 | ||
9101 | -- The same holds within a discriminated synchronized type, | |
9102 | -- where the discriminant may constrain a component or an | |
9103 | -- entry family. | |
ee6ba406 | 9104 | |
9105 | if Nkind (LB) = N_Identifier | |
0577b0b1 | 9106 | and then Denotes_Discriminant (LB, True) |
ee6ba406 | 9107 | then |
0577b0b1 | 9108 | if Current_Scope = Scope (Entity (LB)) |
9109 | or else Is_Concurrent_Type (Current_Scope) | |
9110 | or else Ekind (Entity (LB)) /= E_Discriminant | |
9111 | then | |
ee6ba406 | 9112 | return Ret_Result; |
9113 | else | |
9114 | LB := | |
9115 | New_Occurrence_Of (Discriminal (Entity (LB)), Loc); | |
9116 | end if; | |
9117 | end if; | |
9118 | ||
9119 | if Nkind (HB) = N_Identifier | |
0577b0b1 | 9120 | and then Denotes_Discriminant (HB, True) |
ee6ba406 | 9121 | then |
0577b0b1 | 9122 | if Current_Scope = Scope (Entity (HB)) |
9123 | or else Is_Concurrent_Type (Current_Scope) | |
9124 | or else Ekind (Entity (HB)) /= E_Discriminant | |
9125 | then | |
ee6ba406 | 9126 | return Ret_Result; |
9127 | else | |
9128 | HB := | |
9129 | New_Occurrence_Of (Discriminal (Entity (HB)), Loc); | |
9130 | end if; | |
9131 | end if; | |
9132 | ||
9133 | Cond := Discrete_Range_Cond (Ck_Node, T_Typ); | |
9134 | Set_Paren_Count (Cond, 1); | |
9135 | ||
9136 | Cond := | |
9137 | Make_And_Then (Loc, | |
9138 | Left_Opnd => | |
9139 | Make_Op_Ge (Loc, | |
9dfe12ae | 9140 | Left_Opnd => Duplicate_Subexpr_No_Checks (HB), |
9141 | Right_Opnd => Duplicate_Subexpr_No_Checks (LB)), | |
ee6ba406 | 9142 | Right_Opnd => Cond); |
9143 | end; | |
ee6ba406 | 9144 | end if; |
9145 | end; | |
9146 | ||
9147 | elsif Is_Scalar_Type (S_Typ) then | |
9148 | ||
9149 | -- This somewhat duplicates what Apply_Scalar_Range_Check does, | |
9150 | -- except the above simply sets a flag in the node and lets | |
9151 | -- gigi generate the check base on the Etype of the expression. | |
9152 | -- Sometimes, however we want to do a dynamic check against an | |
9153 | -- arbitrary target type, so we do that here. | |
9154 | ||
9155 | if Ekind (Base_Type (S_Typ)) /= Ekind (Base_Type (T_Typ)) then | |
9156 | Cond := Discrete_Expr_Cond (Ck_Node, T_Typ); | |
9157 | ||
9158 | -- For literals, we can tell if the constraint error will be | |
9159 | -- raised at compile time, so we never need a dynamic check, but | |
9160 | -- if the exception will be raised, then post the usual warning, | |
9161 | -- and replace the literal with a raise constraint error | |
9162 | -- expression. As usual, skip this for access types | |
9163 | ||
20cf157b | 9164 | elsif Compile_Time_Known_Value (Ck_Node) and then not Do_Access then |
ee6ba406 | 9165 | declare |
9166 | LB : constant Node_Id := Type_Low_Bound (T_Typ); | |
9167 | UB : constant Node_Id := Type_High_Bound (T_Typ); | |
9168 | ||
9169 | Out_Of_Range : Boolean; | |
9170 | Static_Bounds : constant Boolean := | |
b6341c67 | 9171 | Compile_Time_Known_Value (LB) |
9172 | and Compile_Time_Known_Value (UB); | |
ee6ba406 | 9173 | |
9174 | begin | |
9175 | -- Following range tests should use Sem_Eval routine ??? | |
9176 | ||
9177 | if Static_Bounds then | |
9178 | if Is_Floating_Point_Type (S_Typ) then | |
9179 | Out_Of_Range := | |
9180 | (Expr_Value_R (Ck_Node) < Expr_Value_R (LB)) | |
9181 | or else | |
9182 | (Expr_Value_R (Ck_Node) > Expr_Value_R (UB)); | |
9183 | ||
eefa141b | 9184 | -- Fixed or discrete type |
9185 | ||
9186 | else | |
ee6ba406 | 9187 | Out_Of_Range := |
9188 | Expr_Value (Ck_Node) < Expr_Value (LB) | |
9189 | or else | |
9190 | Expr_Value (Ck_Node) > Expr_Value (UB); | |
9191 | end if; | |
9192 | ||
eefa141b | 9193 | -- Bounds of the type are static and the literal is out of |
9194 | -- range so output a warning message. | |
ee6ba406 | 9195 | |
9196 | if Out_Of_Range then | |
9197 | if No (Warn_Node) then | |
9198 | Add_Check | |
9199 | (Compile_Time_Constraint_Error | |
9200 | (Ck_Node, | |
cb97ae5c | 9201 | "static value out of range of}??", T_Typ)); |
ee6ba406 | 9202 | |
9203 | else | |
9204 | Add_Check | |
9205 | (Compile_Time_Constraint_Error | |
9206 | (Wnode, | |
cb97ae5c | 9207 | "static value out of range of}??", T_Typ)); |
ee6ba406 | 9208 | end if; |
9209 | end if; | |
9210 | ||
9211 | else | |
9212 | Cond := Discrete_Expr_Cond (Ck_Node, T_Typ); | |
9213 | end if; | |
9214 | end; | |
9215 | ||
9216 | -- Here for the case of a non-static expression, we need a runtime | |
9217 | -- check unless the source type range is guaranteed to be in the | |
9218 | -- range of the target type. | |
9219 | ||
9220 | else | |
7a1dabb3 | 9221 | if not In_Subrange_Of (S_Typ, T_Typ) then |
ee6ba406 | 9222 | Cond := Discrete_Expr_Cond (Ck_Node, T_Typ); |
9223 | end if; | |
9224 | end if; | |
9225 | end if; | |
9226 | ||
9227 | if Is_Array_Type (T_Typ) and then Is_Array_Type (S_Typ) then | |
9228 | if Is_Constrained (T_Typ) then | |
9229 | ||
9230 | Expr_Actual := Get_Referenced_Object (Ck_Node); | |
9231 | Exptyp := Get_Actual_Subtype (Expr_Actual); | |
9232 | ||
9233 | if Is_Access_Type (Exptyp) then | |
9234 | Exptyp := Designated_Type (Exptyp); | |
9235 | end if; | |
9236 | ||
9237 | -- String_Literal case. This needs to be handled specially be- | |
9238 | -- cause no index types are available for string literals. The | |
9239 | -- condition is simply: | |
9240 | ||
9241 | -- T_Typ'Length = string-literal-length | |
9242 | ||
9243 | if Nkind (Expr_Actual) = N_String_Literal then | |
9244 | null; | |
9245 | ||
9246 | -- General array case. Here we have a usable actual subtype for | |
9247 | -- the expression, and the condition is built from the two types | |
9248 | ||
9249 | -- T_Typ'First < Exptyp'First or else | |
9250 | -- T_Typ'Last > Exptyp'Last or else | |
9251 | -- T_Typ'First(1) < Exptyp'First(1) or else | |
9252 | -- T_Typ'Last(1) > Exptyp'Last(1) or else | |
9253 | -- ... | |
9254 | ||
9255 | elsif Is_Constrained (Exptyp) then | |
9256 | declare | |
9dfe12ae | 9257 | Ndims : constant Nat := Number_Dimensions (T_Typ); |
9258 | ||
ee6ba406 | 9259 | L_Index : Node_Id; |
9260 | R_Index : Node_Id; | |
ee6ba406 | 9261 | |
9262 | begin | |
9263 | L_Index := First_Index (T_Typ); | |
9264 | R_Index := First_Index (Exptyp); | |
9265 | ||
9266 | for Indx in 1 .. Ndims loop | |
9267 | if not (Nkind (L_Index) = N_Raise_Constraint_Error | |
f15731c4 | 9268 | or else |
9269 | Nkind (R_Index) = N_Raise_Constraint_Error) | |
ee6ba406 | 9270 | then |
ee6ba406 | 9271 | -- Deal with compile time length check. Note that we |
9272 | -- skip this in the access case, because the access | |
9273 | -- value may be null, so we cannot know statically. | |
9274 | ||
9275 | if not | |
9276 | Subtypes_Statically_Match | |
9277 | (Etype (L_Index), Etype (R_Index)) | |
9278 | then | |
9279 | -- If the target type is constrained then we | |
9280 | -- have to check for exact equality of bounds | |
9281 | -- (required for qualified expressions). | |
9282 | ||
9283 | if Is_Constrained (T_Typ) then | |
9284 | Evolve_Or_Else | |
9285 | (Cond, | |
9286 | Range_Equal_E_Cond (Exptyp, T_Typ, Indx)); | |
ee6ba406 | 9287 | else |
9288 | Evolve_Or_Else | |
9289 | (Cond, Range_E_Cond (Exptyp, T_Typ, Indx)); | |
9290 | end if; | |
9291 | end if; | |
9292 | ||
9293 | Next (L_Index); | |
9294 | Next (R_Index); | |
ee6ba406 | 9295 | end if; |
9296 | end loop; | |
9297 | end; | |
9298 | ||
9299 | -- Handle cases where we do not get a usable actual subtype that | |
9300 | -- is constrained. This happens for example in the function call | |
9301 | -- and explicit dereference cases. In these cases, we have to get | |
9302 | -- the length or range from the expression itself, making sure we | |
9303 | -- do not evaluate it more than once. | |
9304 | ||
9305 | -- Here Ck_Node is the original expression, or more properly the | |
9306 | -- result of applying Duplicate_Expr to the original tree, | |
9307 | -- forcing the result to be a name. | |
9308 | ||
9309 | else | |
9310 | declare | |
9dfe12ae | 9311 | Ndims : constant Nat := Number_Dimensions (T_Typ); |
ee6ba406 | 9312 | |
9313 | begin | |
9314 | -- Build the condition for the explicit dereference case | |
9315 | ||
9316 | for Indx in 1 .. Ndims loop | |
9317 | Evolve_Or_Else | |
9318 | (Cond, Range_N_Cond (Ck_Node, T_Typ, Indx)); | |
9319 | end loop; | |
9320 | end; | |
ee6ba406 | 9321 | end if; |
9322 | ||
9323 | else | |
feff2f05 | 9324 | -- For a conversion to an unconstrained array type, generate an |
9325 | -- Action to check that the bounds of the source value are within | |
9326 | -- the constraints imposed by the target type (RM 4.6(38)). No | |
9327 | -- check is needed for a conversion to an access to unconstrained | |
9328 | -- array type, as 4.6(24.15/2) requires the designated subtypes | |
9329 | -- of the two access types to statically match. | |
9330 | ||
9331 | if Nkind (Parent (Ck_Node)) = N_Type_Conversion | |
9332 | and then not Do_Access | |
9333 | then | |
ee6ba406 | 9334 | declare |
9335 | Opnd_Index : Node_Id; | |
9336 | Targ_Index : Node_Id; | |
00c403ee | 9337 | Opnd_Range : Node_Id; |
ee6ba406 | 9338 | |
9339 | begin | |
feff2f05 | 9340 | Opnd_Index := First_Index (Get_Actual_Subtype (Ck_Node)); |
ee6ba406 | 9341 | Targ_Index := First_Index (T_Typ); |
00c403ee | 9342 | while Present (Opnd_Index) loop |
9343 | ||
9344 | -- If the index is a range, use its bounds. If it is an | |
9345 | -- entity (as will be the case if it is a named subtype | |
9346 | -- or an itype created for a slice) retrieve its range. | |
9347 | ||
9348 | if Is_Entity_Name (Opnd_Index) | |
9349 | and then Is_Type (Entity (Opnd_Index)) | |
9350 | then | |
9351 | Opnd_Range := Scalar_Range (Entity (Opnd_Index)); | |
9352 | else | |
9353 | Opnd_Range := Opnd_Index; | |
9354 | end if; | |
9355 | ||
9356 | if Nkind (Opnd_Range) = N_Range then | |
9c486805 | 9357 | if Is_In_Range |
9358 | (Low_Bound (Opnd_Range), Etype (Targ_Index), | |
9359 | Assume_Valid => True) | |
ee6ba406 | 9360 | and then |
9361 | Is_In_Range | |
9c486805 | 9362 | (High_Bound (Opnd_Range), Etype (Targ_Index), |
9363 | Assume_Valid => True) | |
ee6ba406 | 9364 | then |
9365 | null; | |
9366 | ||
feff2f05 | 9367 | -- If null range, no check needed |
f2a06be9 | 9368 | |
9dfe12ae | 9369 | elsif |
00c403ee | 9370 | Compile_Time_Known_Value (High_Bound (Opnd_Range)) |
9dfe12ae | 9371 | and then |
00c403ee | 9372 | Compile_Time_Known_Value (Low_Bound (Opnd_Range)) |
9dfe12ae | 9373 | and then |
00c403ee | 9374 | Expr_Value (High_Bound (Opnd_Range)) < |
9375 | Expr_Value (Low_Bound (Opnd_Range)) | |
9dfe12ae | 9376 | then |
9377 | null; | |
9378 | ||
ee6ba406 | 9379 | elsif Is_Out_Of_Range |
9c486805 | 9380 | (Low_Bound (Opnd_Range), Etype (Targ_Index), |
9381 | Assume_Valid => True) | |
ee6ba406 | 9382 | or else |
9383 | Is_Out_Of_Range | |
9c486805 | 9384 | (High_Bound (Opnd_Range), Etype (Targ_Index), |
9385 | Assume_Valid => True) | |
ee6ba406 | 9386 | then |
9387 | Add_Check | |
9388 | (Compile_Time_Constraint_Error | |
cb97ae5c | 9389 | (Wnode, "value out of range of}??", T_Typ)); |
ee6ba406 | 9390 | |
9391 | else | |
9392 | Evolve_Or_Else | |
9393 | (Cond, | |
9394 | Discrete_Range_Cond | |
00c403ee | 9395 | (Opnd_Range, Etype (Targ_Index))); |
ee6ba406 | 9396 | end if; |
9397 | end if; | |
9398 | ||
9399 | Next_Index (Opnd_Index); | |
9400 | Next_Index (Targ_Index); | |
9401 | end loop; | |
9402 | end; | |
9403 | end if; | |
9404 | end if; | |
9405 | end if; | |
9406 | ||
9407 | -- Construct the test and insert into the tree | |
9408 | ||
9409 | if Present (Cond) then | |
9410 | if Do_Access then | |
9411 | Cond := Guard_Access (Cond, Loc, Ck_Node); | |
9412 | end if; | |
9413 | ||
f15731c4 | 9414 | Add_Check |
9415 | (Make_Raise_Constraint_Error (Loc, | |
eefa141b | 9416 | Condition => Cond, |
9417 | Reason => CE_Range_Check_Failed)); | |
ee6ba406 | 9418 | end if; |
9419 | ||
9420 | return Ret_Result; | |
ee6ba406 | 9421 | end Selected_Range_Checks; |
9422 | ||
9423 | ------------------------------- | |
9424 | -- Storage_Checks_Suppressed -- | |
9425 | ------------------------------- | |
9426 | ||
9427 | function Storage_Checks_Suppressed (E : Entity_Id) return Boolean is | |
9428 | begin | |
9dfe12ae | 9429 | if Present (E) and then Checks_May_Be_Suppressed (E) then |
9430 | return Is_Check_Suppressed (E, Storage_Check); | |
9431 | else | |
fafc6b97 | 9432 | return Scope_Suppress.Suppress (Storage_Check); |
9dfe12ae | 9433 | end if; |
ee6ba406 | 9434 | end Storage_Checks_Suppressed; |
9435 | ||
9436 | --------------------------- | |
9437 | -- Tag_Checks_Suppressed -- | |
9438 | --------------------------- | |
9439 | ||
9440 | function Tag_Checks_Suppressed (E : Entity_Id) return Boolean is | |
9441 | begin | |
89f1e35c | 9442 | if Present (E) |
9443 | and then Checks_May_Be_Suppressed (E) | |
9444 | then | |
9445 | return Is_Check_Suppressed (E, Tag_Check); | |
20cf157b | 9446 | else |
9447 | return Scope_Suppress.Suppress (Tag_Check); | |
9dfe12ae | 9448 | end if; |
ee6ba406 | 9449 | end Tag_Checks_Suppressed; |
9450 | ||
0577b0b1 | 9451 | -------------------------- |
9452 | -- Validity_Check_Range -- | |
9453 | -------------------------- | |
9454 | ||
9455 | procedure Validity_Check_Range (N : Node_Id) is | |
9456 | begin | |
9457 | if Validity_Checks_On and Validity_Check_Operands then | |
9458 | if Nkind (N) = N_Range then | |
9459 | Ensure_Valid (Low_Bound (N)); | |
9460 | Ensure_Valid (High_Bound (N)); | |
9461 | end if; | |
9462 | end if; | |
9463 | end Validity_Check_Range; | |
9464 | ||
9465 | -------------------------------- | |
9466 | -- Validity_Checks_Suppressed -- | |
9467 | -------------------------------- | |
9468 | ||
9469 | function Validity_Checks_Suppressed (E : Entity_Id) return Boolean is | |
9470 | begin | |
9471 | if Present (E) and then Checks_May_Be_Suppressed (E) then | |
9472 | return Is_Check_Suppressed (E, Validity_Check); | |
9473 | else | |
fafc6b97 | 9474 | return Scope_Suppress.Suppress (Validity_Check); |
0577b0b1 | 9475 | end if; |
9476 | end Validity_Checks_Suppressed; | |
9477 | ||
ee6ba406 | 9478 | end Checks; |