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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 | -- -- | |
a781c0fc | 9 | -- Copyright (C) 1992-2009, 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; | |
27 | with Debug; use Debug; | |
28 | with Einfo; use Einfo; | |
29 | with Errout; use Errout; | |
30 | with Exp_Ch2; use Exp_Ch2; | |
00c403ee | 31 | with Exp_Ch11; use Exp_Ch11; |
05fcfafb | 32 | with Exp_Pakd; use Exp_Pakd; |
ee6ba406 | 33 | with Exp_Util; use Exp_Util; |
34 | with Elists; use Elists; | |
5329ca64 | 35 | with Eval_Fat; use Eval_Fat; |
ee6ba406 | 36 | with Freeze; use Freeze; |
9dfe12ae | 37 | with Lib; use Lib; |
ee6ba406 | 38 | with Nlists; use Nlists; |
39 | with Nmake; use Nmake; | |
40 | with Opt; use Opt; | |
9dfe12ae | 41 | with Output; use Output; |
c2b56224 | 42 | with Restrict; use Restrict; |
1e16c51c | 43 | with Rident; use Rident; |
ee6ba406 | 44 | with Rtsfind; use Rtsfind; |
45 | with Sem; use Sem; | |
d60c9ff7 | 46 | with Sem_Aux; use Sem_Aux; |
ee6ba406 | 47 | with Sem_Eval; use Sem_Eval; |
00f91aef | 48 | with Sem_Ch3; use Sem_Ch3; |
9dfe12ae | 49 | with Sem_Ch8; use Sem_Ch8; |
ee6ba406 | 50 | with Sem_Res; use Sem_Res; |
51 | with Sem_Util; use Sem_Util; | |
52 | with Sem_Warn; use Sem_Warn; | |
53 | with Sinfo; use Sinfo; | |
9dfe12ae | 54 | with Sinput; use Sinput; |
ee6ba406 | 55 | with Snames; use Snames; |
9dfe12ae | 56 | with Sprint; use Sprint; |
ee6ba406 | 57 | with Stand; use Stand; |
f15731c4 | 58 | with Targparm; use Targparm; |
ee6ba406 | 59 | with Tbuild; use Tbuild; |
60 | with Ttypes; use Ttypes; | |
61 | with Urealp; use Urealp; | |
62 | with Validsw; use Validsw; | |
63 | ||
64 | package body Checks is | |
65 | ||
66 | -- General note: many of these routines are concerned with generating | |
67 | -- checking code to make sure that constraint error is raised at runtime. | |
68 | -- Clearly this code is only needed if the expander is active, since | |
69 | -- otherwise we will not be generating code or going into the runtime | |
70 | -- execution anyway. | |
71 | ||
72 | -- We therefore disconnect most of these checks if the expander is | |
73 | -- inactive. This has the additional benefit that we do not need to | |
74 | -- worry about the tree being messed up by previous errors (since errors | |
75 | -- turn off expansion anyway). | |
76 | ||
77 | -- There are a few exceptions to the above rule. For instance routines | |
78 | -- such as Apply_Scalar_Range_Check that do not insert any code can be | |
79 | -- safely called even when the Expander is inactive (but Errors_Detected | |
80 | -- is 0). The benefit of executing this code when expansion is off, is | |
81 | -- the ability to emit constraint error warning for static expressions | |
82 | -- even when we are not generating code. | |
83 | ||
9dfe12ae | 84 | ------------------------------------- |
85 | -- Suppression of Redundant Checks -- | |
86 | ------------------------------------- | |
87 | ||
88 | -- This unit implements a limited circuit for removal of redundant | |
89 | -- checks. The processing is based on a tracing of simple sequential | |
90 | -- flow. For any sequence of statements, we save expressions that are | |
91 | -- marked to be checked, and then if the same expression appears later | |
92 | -- with the same check, then under certain circumstances, the second | |
93 | -- check can be suppressed. | |
94 | ||
95 | -- Basically, we can suppress the check if we know for certain that | |
96 | -- the previous expression has been elaborated (together with its | |
97 | -- check), and we know that the exception frame is the same, and that | |
98 | -- nothing has happened to change the result of the exception. | |
99 | ||
100 | -- Let us examine each of these three conditions in turn to describe | |
101 | -- how we ensure that this condition is met. | |
102 | ||
103 | -- First, we need to know for certain that the previous expression has | |
104 | -- been executed. This is done principly by the mechanism of calling | |
105 | -- Conditional_Statements_Begin at the start of any statement sequence | |
106 | -- and Conditional_Statements_End at the end. The End call causes all | |
107 | -- checks remembered since the Begin call to be discarded. This does | |
108 | -- miss a few cases, notably the case of a nested BEGIN-END block with | |
109 | -- no exception handlers. But the important thing is to be conservative. | |
110 | -- The other protection is that all checks are discarded if a label | |
111 | -- is encountered, since then the assumption of sequential execution | |
112 | -- is violated, and we don't know enough about the flow. | |
113 | ||
114 | -- Second, we need to know that the exception frame is the same. We | |
115 | -- do this by killing all remembered checks when we enter a new frame. | |
116 | -- Again, that's over-conservative, but generally the cases we can help | |
117 | -- with are pretty local anyway (like the body of a loop for example). | |
118 | ||
119 | -- Third, we must be sure to forget any checks which are no longer valid. | |
120 | -- This is done by two mechanisms, first the Kill_Checks_Variable call is | |
121 | -- used to note any changes to local variables. We only attempt to deal | |
122 | -- with checks involving local variables, so we do not need to worry | |
123 | -- about global variables. Second, a call to any non-global procedure | |
124 | -- causes us to abandon all stored checks, since such a all may affect | |
125 | -- the values of any local variables. | |
126 | ||
127 | -- The following define the data structures used to deal with remembering | |
128 | -- checks so that redundant checks can be eliminated as described above. | |
129 | ||
130 | -- Right now, the only expressions that we deal with are of the form of | |
131 | -- simple local objects (either declared locally, or IN parameters) or | |
132 | -- such objects plus/minus a compile time known constant. We can do | |
133 | -- more later on if it seems worthwhile, but this catches many simple | |
134 | -- cases in practice. | |
135 | ||
136 | -- The following record type reflects a single saved check. An entry | |
137 | -- is made in the stack of saved checks if and only if the expression | |
138 | -- has been elaborated with the indicated checks. | |
139 | ||
140 | type Saved_Check is record | |
141 | Killed : Boolean; | |
142 | -- Set True if entry is killed by Kill_Checks | |
143 | ||
144 | Entity : Entity_Id; | |
145 | -- The entity involved in the expression that is checked | |
146 | ||
147 | Offset : Uint; | |
148 | -- A compile time value indicating the result of adding or | |
149 | -- subtracting a compile time value. This value is to be | |
150 | -- added to the value of the Entity. A value of zero is | |
151 | -- used for the case of a simple entity reference. | |
152 | ||
153 | Check_Type : Character; | |
154 | -- This is set to 'R' for a range check (in which case Target_Type | |
155 | -- is set to the target type for the range check) or to 'O' for an | |
156 | -- overflow check (in which case Target_Type is set to Empty). | |
157 | ||
158 | Target_Type : Entity_Id; | |
159 | -- Used only if Do_Range_Check is set. Records the target type for | |
160 | -- the check. We need this, because a check is a duplicate only if | |
161 | -- it has a the same target type (or more accurately one with a | |
162 | -- range that is smaller or equal to the stored target type of a | |
163 | -- saved check). | |
164 | end record; | |
165 | ||
166 | -- The following table keeps track of saved checks. Rather than use an | |
167 | -- extensible table. We just use a table of fixed size, and we discard | |
168 | -- any saved checks that do not fit. That's very unlikely to happen and | |
169 | -- this is only an optimization in any case. | |
170 | ||
171 | Saved_Checks : array (Int range 1 .. 200) of Saved_Check; | |
172 | -- Array of saved checks | |
173 | ||
174 | Num_Saved_Checks : Nat := 0; | |
175 | -- Number of saved checks | |
176 | ||
177 | -- The following stack keeps track of statement ranges. It is treated | |
178 | -- as a stack. When Conditional_Statements_Begin is called, an entry | |
179 | -- is pushed onto this stack containing the value of Num_Saved_Checks | |
180 | -- at the time of the call. Then when Conditional_Statements_End is | |
181 | -- called, this value is popped off and used to reset Num_Saved_Checks. | |
182 | ||
183 | -- Note: again, this is a fixed length stack with a size that should | |
184 | -- always be fine. If the value of the stack pointer goes above the | |
185 | -- limit, then we just forget all saved checks. | |
186 | ||
187 | Saved_Checks_Stack : array (Int range 1 .. 100) of Nat; | |
188 | Saved_Checks_TOS : Nat := 0; | |
189 | ||
190 | ----------------------- | |
191 | -- Local Subprograms -- | |
192 | ----------------------- | |
ee6ba406 | 193 | |
5329ca64 | 194 | procedure Apply_Float_Conversion_Check |
195 | (Ck_Node : Node_Id; | |
196 | Target_Typ : Entity_Id); | |
197 | -- The checks on a conversion from a floating-point type to an integer | |
198 | -- type are delicate. They have to be performed before conversion, they | |
199 | -- have to raise an exception when the operand is a NaN, and rounding must | |
200 | -- be taken into account to determine the safe bounds of the operand. | |
201 | ||
ee6ba406 | 202 | procedure Apply_Selected_Length_Checks |
203 | (Ck_Node : Node_Id; | |
204 | Target_Typ : Entity_Id; | |
205 | Source_Typ : Entity_Id; | |
206 | Do_Static : Boolean); | |
207 | -- This is the subprogram that does all the work for Apply_Length_Check | |
208 | -- and Apply_Static_Length_Check. Expr, Target_Typ and Source_Typ are as | |
209 | -- described for the above routines. The Do_Static flag indicates that | |
210 | -- only a static check is to be done. | |
211 | ||
212 | procedure Apply_Selected_Range_Checks | |
213 | (Ck_Node : Node_Id; | |
214 | Target_Typ : Entity_Id; | |
215 | Source_Typ : Entity_Id; | |
216 | Do_Static : Boolean); | |
217 | -- This is the subprogram that does all the work for Apply_Range_Check. | |
218 | -- Expr, Target_Typ and Source_Typ are as described for the above | |
219 | -- routine. The Do_Static flag indicates that only a static check is | |
220 | -- to be done. | |
221 | ||
2af58f67 | 222 | type Check_Type is new Check_Id range Access_Check .. Division_Check; |
13dbf220 | 223 | function Check_Needed (Nod : Node_Id; Check : Check_Type) return Boolean; |
224 | -- This function is used to see if an access or division by zero check is | |
225 | -- needed. The check is to be applied to a single variable appearing in the | |
226 | -- source, and N is the node for the reference. If N is not of this form, | |
227 | -- True is returned with no further processing. If N is of the right form, | |
228 | -- then further processing determines if the given Check is needed. | |
229 | -- | |
230 | -- The particular circuit is to see if we have the case of a check that is | |
231 | -- not needed because it appears in the right operand of a short circuited | |
232 | -- conditional where the left operand guards the check. For example: | |
233 | -- | |
234 | -- if Var = 0 or else Q / Var > 12 then | |
235 | -- ... | |
236 | -- end if; | |
237 | -- | |
238 | -- In this example, the division check is not required. At the same time | |
239 | -- we can issue warnings for suspicious use of non-short-circuited forms, | |
240 | -- such as: | |
241 | -- | |
242 | -- if Var = 0 or Q / Var > 12 then | |
243 | -- ... | |
244 | -- end if; | |
245 | ||
9dfe12ae | 246 | procedure Find_Check |
247 | (Expr : Node_Id; | |
248 | Check_Type : Character; | |
249 | Target_Type : Entity_Id; | |
250 | Entry_OK : out Boolean; | |
251 | Check_Num : out Nat; | |
252 | Ent : out Entity_Id; | |
253 | Ofs : out Uint); | |
254 | -- This routine is used by Enable_Range_Check and Enable_Overflow_Check | |
255 | -- to see if a check is of the form for optimization, and if so, to see | |
256 | -- if it has already been performed. Expr is the expression to check, | |
257 | -- and Check_Type is 'R' for a range check, 'O' for an overflow check. | |
258 | -- Target_Type is the target type for a range check, and Empty for an | |
259 | -- overflow check. If the entry is not of the form for optimization, | |
260 | -- then Entry_OK is set to False, and the remaining out parameters | |
261 | -- are undefined. If the entry is OK, then Ent/Ofs are set to the | |
262 | -- entity and offset from the expression. Check_Num is the number of | |
263 | -- a matching saved entry in Saved_Checks, or zero if no such entry | |
264 | -- is located. | |
265 | ||
ee6ba406 | 266 | function Get_Discriminal (E : Entity_Id; Bound : Node_Id) return Node_Id; |
267 | -- If a discriminal is used in constraining a prival, Return reference | |
268 | -- to the discriminal of the protected body (which renames the parameter | |
269 | -- of the enclosing protected operation). This clumsy transformation is | |
270 | -- needed because privals are created too late and their actual subtypes | |
271 | -- are not available when analysing the bodies of the protected operations. | |
0577b0b1 | 272 | -- This function is called whenever the bound is an entity and the scope |
273 | -- indicates a protected operation. If the bound is an in-parameter of | |
274 | -- a protected operation that is not a prival, the function returns the | |
275 | -- bound itself. | |
ee6ba406 | 276 | -- To be cleaned up??? |
277 | ||
278 | function Guard_Access | |
279 | (Cond : Node_Id; | |
280 | Loc : Source_Ptr; | |
314a23b6 | 281 | Ck_Node : Node_Id) return Node_Id; |
ee6ba406 | 282 | -- In the access type case, guard the test with a test to ensure |
283 | -- that the access value is non-null, since the checks do not | |
284 | -- not apply to null access values. | |
285 | ||
286 | procedure Install_Static_Check (R_Cno : Node_Id; Loc : Source_Ptr); | |
287 | -- Called by Apply_{Length,Range}_Checks to rewrite the tree with the | |
288 | -- Constraint_Error node. | |
289 | ||
0577b0b1 | 290 | function Range_Or_Validity_Checks_Suppressed |
291 | (Expr : Node_Id) return Boolean; | |
292 | -- Returns True if either range or validity checks or both are suppressed | |
293 | -- for the type of the given expression, or, if the expression is the name | |
294 | -- of an entity, if these checks are suppressed for the entity. | |
295 | ||
ee6ba406 | 296 | function Selected_Length_Checks |
297 | (Ck_Node : Node_Id; | |
298 | Target_Typ : Entity_Id; | |
299 | Source_Typ : Entity_Id; | |
314a23b6 | 300 | Warn_Node : Node_Id) return Check_Result; |
ee6ba406 | 301 | -- Like Apply_Selected_Length_Checks, except it doesn't modify |
302 | -- anything, just returns a list of nodes as described in the spec of | |
303 | -- this package for the Range_Check function. | |
304 | ||
305 | function Selected_Range_Checks | |
306 | (Ck_Node : Node_Id; | |
307 | Target_Typ : Entity_Id; | |
308 | Source_Typ : Entity_Id; | |
314a23b6 | 309 | Warn_Node : Node_Id) return Check_Result; |
ee6ba406 | 310 | -- Like Apply_Selected_Range_Checks, except it doesn't modify anything, |
311 | -- just returns a list of nodes as described in the spec of this package | |
312 | -- for the Range_Check function. | |
313 | ||
314 | ------------------------------ | |
315 | -- Access_Checks_Suppressed -- | |
316 | ------------------------------ | |
317 | ||
318 | function Access_Checks_Suppressed (E : Entity_Id) return Boolean is | |
319 | begin | |
9dfe12ae | 320 | if Present (E) and then Checks_May_Be_Suppressed (E) then |
321 | return Is_Check_Suppressed (E, Access_Check); | |
322 | else | |
323 | return Scope_Suppress (Access_Check); | |
324 | end if; | |
ee6ba406 | 325 | end Access_Checks_Suppressed; |
326 | ||
327 | ------------------------------------- | |
328 | -- Accessibility_Checks_Suppressed -- | |
329 | ------------------------------------- | |
330 | ||
331 | function Accessibility_Checks_Suppressed (E : Entity_Id) return Boolean is | |
332 | begin | |
9dfe12ae | 333 | if Present (E) and then Checks_May_Be_Suppressed (E) then |
334 | return Is_Check_Suppressed (E, Accessibility_Check); | |
335 | else | |
336 | return Scope_Suppress (Accessibility_Check); | |
337 | end if; | |
ee6ba406 | 338 | end Accessibility_Checks_Suppressed; |
339 | ||
00c403ee | 340 | ----------------------------- |
341 | -- Activate_Division_Check -- | |
342 | ----------------------------- | |
343 | ||
344 | procedure Activate_Division_Check (N : Node_Id) is | |
345 | begin | |
346 | Set_Do_Division_Check (N, True); | |
347 | Possible_Local_Raise (N, Standard_Constraint_Error); | |
348 | end Activate_Division_Check; | |
349 | ||
350 | ----------------------------- | |
351 | -- Activate_Overflow_Check -- | |
352 | ----------------------------- | |
353 | ||
354 | procedure Activate_Overflow_Check (N : Node_Id) is | |
355 | begin | |
356 | Set_Do_Overflow_Check (N, True); | |
357 | Possible_Local_Raise (N, Standard_Constraint_Error); | |
358 | end Activate_Overflow_Check; | |
359 | ||
360 | -------------------------- | |
361 | -- Activate_Range_Check -- | |
362 | -------------------------- | |
363 | ||
364 | procedure Activate_Range_Check (N : Node_Id) is | |
365 | begin | |
366 | Set_Do_Range_Check (N, True); | |
367 | Possible_Local_Raise (N, Standard_Constraint_Error); | |
368 | end Activate_Range_Check; | |
369 | ||
0577b0b1 | 370 | --------------------------------- |
371 | -- Alignment_Checks_Suppressed -- | |
372 | --------------------------------- | |
373 | ||
374 | function Alignment_Checks_Suppressed (E : Entity_Id) return Boolean is | |
375 | begin | |
376 | if Present (E) and then Checks_May_Be_Suppressed (E) then | |
377 | return Is_Check_Suppressed (E, Alignment_Check); | |
378 | else | |
379 | return Scope_Suppress (Alignment_Check); | |
380 | end if; | |
381 | end Alignment_Checks_Suppressed; | |
382 | ||
ee6ba406 | 383 | ------------------------- |
384 | -- Append_Range_Checks -- | |
385 | ------------------------- | |
386 | ||
387 | procedure Append_Range_Checks | |
388 | (Checks : Check_Result; | |
389 | Stmts : List_Id; | |
390 | Suppress_Typ : Entity_Id; | |
391 | Static_Sloc : Source_Ptr; | |
392 | Flag_Node : Node_Id) | |
393 | is | |
9dfe12ae | 394 | Internal_Flag_Node : constant Node_Id := Flag_Node; |
395 | Internal_Static_Sloc : constant Source_Ptr := Static_Sloc; | |
396 | ||
ee6ba406 | 397 | Checks_On : constant Boolean := |
398 | (not Index_Checks_Suppressed (Suppress_Typ)) | |
399 | or else | |
400 | (not Range_Checks_Suppressed (Suppress_Typ)); | |
401 | ||
402 | begin | |
403 | -- For now we just return if Checks_On is false, however this should | |
404 | -- be enhanced to check for an always True value in the condition | |
405 | -- and to generate a compilation warning??? | |
406 | ||
407 | if not Checks_On then | |
408 | return; | |
409 | end if; | |
410 | ||
411 | for J in 1 .. 2 loop | |
412 | exit when No (Checks (J)); | |
413 | ||
414 | if Nkind (Checks (J)) = N_Raise_Constraint_Error | |
415 | and then Present (Condition (Checks (J))) | |
416 | then | |
417 | if not Has_Dynamic_Range_Check (Internal_Flag_Node) then | |
418 | Append_To (Stmts, Checks (J)); | |
419 | Set_Has_Dynamic_Range_Check (Internal_Flag_Node); | |
420 | end if; | |
421 | ||
422 | else | |
423 | Append_To | |
f15731c4 | 424 | (Stmts, |
425 | Make_Raise_Constraint_Error (Internal_Static_Sloc, | |
426 | Reason => CE_Range_Check_Failed)); | |
ee6ba406 | 427 | end if; |
428 | end loop; | |
429 | end Append_Range_Checks; | |
430 | ||
431 | ------------------------ | |
432 | -- Apply_Access_Check -- | |
433 | ------------------------ | |
434 | ||
435 | procedure Apply_Access_Check (N : Node_Id) is | |
436 | P : constant Node_Id := Prefix (N); | |
437 | ||
438 | begin | |
13dbf220 | 439 | -- We do not need checks if we are not generating code (i.e. the |
440 | -- expander is not active). This is not just an optimization, there | |
441 | -- are cases (e.g. with pragma Debug) where generating the checks | |
442 | -- can cause real trouble). | |
284faf8b | 443 | |
84d0d4a5 | 444 | if not Expander_Active then |
13dbf220 | 445 | return; |
9dfe12ae | 446 | end if; |
ee6ba406 | 447 | |
84d0d4a5 | 448 | -- No check if short circuiting makes check unnecessary |
9dfe12ae | 449 | |
84d0d4a5 | 450 | if not Check_Needed (P, Access_Check) then |
451 | return; | |
ee6ba406 | 452 | end if; |
9dfe12ae | 453 | |
cc60bd16 | 454 | -- No check if accessing the Offset_To_Top component of a dispatch |
455 | -- table. They are safe by construction. | |
456 | ||
457 | if Present (Etype (P)) | |
458 | and then RTU_Loaded (Ada_Tags) | |
459 | and then RTE_Available (RE_Offset_To_Top_Ptr) | |
460 | and then Etype (P) = RTE (RE_Offset_To_Top_Ptr) | |
461 | then | |
462 | return; | |
463 | end if; | |
464 | ||
84d0d4a5 | 465 | -- Otherwise go ahead and install the check |
9dfe12ae | 466 | |
fa7497e8 | 467 | Install_Null_Excluding_Check (P); |
ee6ba406 | 468 | end Apply_Access_Check; |
469 | ||
470 | ------------------------------- | |
471 | -- Apply_Accessibility_Check -- | |
472 | ------------------------------- | |
473 | ||
55dc6dc2 | 474 | procedure Apply_Accessibility_Check |
475 | (N : Node_Id; | |
476 | Typ : Entity_Id; | |
477 | Insert_Node : Node_Id) | |
478 | is | |
ee6ba406 | 479 | Loc : constant Source_Ptr := Sloc (N); |
480 | Param_Ent : constant Entity_Id := Param_Entity (N); | |
481 | Param_Level : Node_Id; | |
482 | Type_Level : Node_Id; | |
483 | ||
484 | begin | |
485 | if Inside_A_Generic then | |
486 | return; | |
487 | ||
488 | -- Only apply the run-time check if the access parameter | |
489 | -- has an associated extra access level parameter and | |
490 | -- when the level of the type is less deep than the level | |
491 | -- of the access parameter. | |
492 | ||
493 | elsif Present (Param_Ent) | |
494 | and then Present (Extra_Accessibility (Param_Ent)) | |
495 | and then UI_Gt (Object_Access_Level (N), | |
496 | Type_Access_Level (Typ)) | |
497 | and then not Accessibility_Checks_Suppressed (Param_Ent) | |
498 | and then not Accessibility_Checks_Suppressed (Typ) | |
499 | then | |
500 | Param_Level := | |
501 | New_Occurrence_Of (Extra_Accessibility (Param_Ent), Loc); | |
502 | ||
503 | Type_Level := | |
504 | Make_Integer_Literal (Loc, Type_Access_Level (Typ)); | |
505 | ||
bf3e1520 | 506 | -- Raise Program_Error if the accessibility level of the access |
84d0d4a5 | 507 | -- parameter is deeper than the level of the target access type. |
ee6ba406 | 508 | |
55dc6dc2 | 509 | Insert_Action (Insert_Node, |
ee6ba406 | 510 | Make_Raise_Program_Error (Loc, |
511 | Condition => | |
512 | Make_Op_Gt (Loc, | |
513 | Left_Opnd => Param_Level, | |
f15731c4 | 514 | Right_Opnd => Type_Level), |
515 | Reason => PE_Accessibility_Check_Failed)); | |
ee6ba406 | 516 | |
517 | Analyze_And_Resolve (N); | |
518 | end if; | |
519 | end Apply_Accessibility_Check; | |
520 | ||
0577b0b1 | 521 | -------------------------------- |
522 | -- Apply_Address_Clause_Check -- | |
523 | -------------------------------- | |
524 | ||
525 | procedure Apply_Address_Clause_Check (E : Entity_Id; N : Node_Id) is | |
526 | AC : constant Node_Id := Address_Clause (E); | |
527 | Loc : constant Source_Ptr := Sloc (AC); | |
528 | Typ : constant Entity_Id := Etype (E); | |
529 | Aexp : constant Node_Id := Expression (AC); | |
c2b56224 | 530 | |
c2b56224 | 531 | Expr : Node_Id; |
0577b0b1 | 532 | -- Address expression (not necessarily the same as Aexp, for example |
533 | -- when Aexp is a reference to a constant, in which case Expr gets | |
534 | -- reset to reference the value expression of the constant. | |
535 | ||
536 | Size_Warning_Output : Boolean := False; | |
537 | -- If we output a size warning we set this True, to stop generating | |
538 | -- what is likely to be an unuseful redundant alignment warning. | |
539 | ||
540 | procedure Compile_Time_Bad_Alignment; | |
541 | -- Post error warnings when alignment is known to be incompatible. Note | |
542 | -- that we do not go as far as inserting a raise of Program_Error since | |
543 | -- this is an erroneous case, and it may happen that we are lucky and an | |
544 | -- underaligned address turns out to be OK after all. Also this warning | |
545 | -- is suppressed if we already complained about the size. | |
546 | ||
547 | -------------------------------- | |
548 | -- Compile_Time_Bad_Alignment -- | |
549 | -------------------------------- | |
550 | ||
551 | procedure Compile_Time_Bad_Alignment is | |
552 | begin | |
553 | if not Size_Warning_Output | |
554 | and then Address_Clause_Overlay_Warnings | |
555 | then | |
556 | Error_Msg_FE | |
557 | ("?specified address for& may be inconsistent with alignment ", | |
558 | Aexp, E); | |
559 | Error_Msg_FE | |
2af58f67 | 560 | ("\?program execution may be erroneous (RM 13.3(27))", |
0577b0b1 | 561 | Aexp, E); |
83f8f0a6 | 562 | Set_Address_Warning_Posted (AC); |
0577b0b1 | 563 | end if; |
564 | end Compile_Time_Bad_Alignment; | |
c2b56224 | 565 | |
2af58f67 | 566 | -- Start of processing for Apply_Address_Clause_Check |
5c61a0ff | 567 | |
c2b56224 | 568 | begin |
0577b0b1 | 569 | -- First obtain expression from address clause |
9dfe12ae | 570 | |
0577b0b1 | 571 | Expr := Expression (AC); |
572 | ||
573 | -- The following loop digs for the real expression to use in the check | |
574 | ||
575 | loop | |
576 | -- For constant, get constant expression | |
577 | ||
578 | if Is_Entity_Name (Expr) | |
579 | and then Ekind (Entity (Expr)) = E_Constant | |
580 | then | |
581 | Expr := Constant_Value (Entity (Expr)); | |
582 | ||
583 | -- For unchecked conversion, get result to convert | |
584 | ||
585 | elsif Nkind (Expr) = N_Unchecked_Type_Conversion then | |
586 | Expr := Expression (Expr); | |
587 | ||
588 | -- For (common case) of To_Address call, get argument | |
589 | ||
590 | elsif Nkind (Expr) = N_Function_Call | |
591 | and then Is_Entity_Name (Name (Expr)) | |
592 | and then Is_RTE (Entity (Name (Expr)), RE_To_Address) | |
593 | then | |
594 | Expr := First (Parameter_Associations (Expr)); | |
595 | ||
596 | if Nkind (Expr) = N_Parameter_Association then | |
597 | Expr := Explicit_Actual_Parameter (Expr); | |
598 | end if; | |
599 | ||
600 | -- We finally have the real expression | |
601 | ||
602 | else | |
603 | exit; | |
604 | end if; | |
605 | end loop; | |
606 | ||
607 | -- Output a warning if we have the situation of | |
608 | ||
609 | -- for X'Address use Y'Address | |
610 | ||
611 | -- and X and Y both have known object sizes, and Y is smaller than X | |
612 | ||
613 | if Nkind (Expr) = N_Attribute_Reference | |
614 | and then Attribute_Name (Expr) = Name_Address | |
615 | and then Is_Entity_Name (Prefix (Expr)) | |
9dfe12ae | 616 | then |
0577b0b1 | 617 | declare |
618 | Exp_Ent : constant Entity_Id := Entity (Prefix (Expr)); | |
619 | Obj_Size : Uint := No_Uint; | |
620 | Exp_Size : Uint := No_Uint; | |
621 | ||
622 | begin | |
623 | if Known_Esize (E) then | |
624 | Obj_Size := Esize (E); | |
625 | elsif Known_Esize (Etype (E)) then | |
626 | Obj_Size := Esize (Etype (E)); | |
627 | end if; | |
628 | ||
629 | if Known_Esize (Exp_Ent) then | |
630 | Exp_Size := Esize (Exp_Ent); | |
631 | elsif Known_Esize (Etype (Exp_Ent)) then | |
632 | Exp_Size := Esize (Etype (Exp_Ent)); | |
633 | end if; | |
634 | ||
635 | if Obj_Size /= No_Uint | |
636 | and then Exp_Size /= No_Uint | |
637 | and then Obj_Size > Exp_Size | |
ce7498d3 | 638 | and then not Has_Warnings_Off (E) |
0577b0b1 | 639 | then |
640 | if Address_Clause_Overlay_Warnings then | |
641 | Error_Msg_FE | |
642 | ("?& overlays smaller object", Aexp, E); | |
643 | Error_Msg_FE | |
644 | ("\?program execution may be erroneous", Aexp, E); | |
645 | Size_Warning_Output := True; | |
83f8f0a6 | 646 | Set_Address_Warning_Posted (AC); |
0577b0b1 | 647 | end if; |
648 | end if; | |
649 | end; | |
c2b56224 | 650 | end if; |
651 | ||
0577b0b1 | 652 | -- See if alignment check needed. Note that we never need a check if the |
653 | -- maximum alignment is one, since the check will always succeed. | |
c2b56224 | 654 | |
0577b0b1 | 655 | -- Note: we do not check for checks suppressed here, since that check |
2af58f67 | 656 | -- was done in Sem_Ch13 when the address clause was processed. We are |
0577b0b1 | 657 | -- only called if checks were not suppressed. The reason for this is |
658 | -- that we have to delay the call to Apply_Alignment_Check till freeze | |
659 | -- time (so that all types etc are elaborated), but we have to check | |
660 | -- the status of check suppressing at the point of the address clause. | |
c2b56224 | 661 | |
0577b0b1 | 662 | if No (AC) |
663 | or else not Check_Address_Alignment (AC) | |
664 | or else Maximum_Alignment = 1 | |
c2b56224 | 665 | then |
0577b0b1 | 666 | return; |
c2b56224 | 667 | end if; |
668 | ||
0577b0b1 | 669 | -- See if we know that Expr is a bad alignment at compile time |
c2b56224 | 670 | |
671 | if Compile_Time_Known_Value (Expr) | |
f2a06be9 | 672 | and then (Known_Alignment (E) or else Known_Alignment (Typ)) |
c2b56224 | 673 | then |
f2a06be9 | 674 | declare |
675 | AL : Uint := Alignment (Typ); | |
676 | ||
677 | begin | |
678 | -- The object alignment might be more restrictive than the | |
679 | -- type alignment. | |
680 | ||
681 | if Known_Alignment (E) then | |
682 | AL := Alignment (E); | |
683 | end if; | |
684 | ||
685 | if Expr_Value (Expr) mod AL /= 0 then | |
0577b0b1 | 686 | Compile_Time_Bad_Alignment; |
687 | else | |
688 | return; | |
f2a06be9 | 689 | end if; |
690 | end; | |
c2b56224 | 691 | |
0577b0b1 | 692 | -- If the expression has the form X'Address, then we can find out if |
693 | -- the object X has an alignment that is compatible with the object E. | |
c2b56224 | 694 | |
0577b0b1 | 695 | elsif Nkind (Expr) = N_Attribute_Reference |
696 | and then Attribute_Name (Expr) = Name_Address | |
697 | then | |
698 | declare | |
699 | AR : constant Alignment_Result := | |
700 | Has_Compatible_Alignment (E, Prefix (Expr)); | |
701 | begin | |
702 | if AR = Known_Compatible then | |
703 | return; | |
704 | elsif AR = Known_Incompatible then | |
705 | Compile_Time_Bad_Alignment; | |
706 | end if; | |
707 | end; | |
708 | end if; | |
c2b56224 | 709 | |
0577b0b1 | 710 | -- Here we do not know if the value is acceptable. Stricly we don't have |
711 | -- to do anything, since if the alignment is bad, we have an erroneous | |
712 | -- program. However we are allowed to check for erroneous conditions and | |
713 | -- we decide to do this by default if the check is not suppressed. | |
714 | ||
715 | -- However, don't do the check if elaboration code is unwanted | |
716 | ||
717 | if Restriction_Active (No_Elaboration_Code) then | |
718 | return; | |
719 | ||
720 | -- Generate a check to raise PE if alignment may be inappropriate | |
721 | ||
722 | else | |
723 | -- If the original expression is a non-static constant, use the | |
724 | -- name of the constant itself rather than duplicating its | |
00c403ee | 725 | -- defining expression, which was extracted above. |
0577b0b1 | 726 | |
00c403ee | 727 | -- Note: Expr is empty if the address-clause is applied to in-mode |
728 | -- actuals (allowed by 13.1(22)). | |
729 | ||
730 | if not Present (Expr) | |
731 | or else | |
732 | (Is_Entity_Name (Expression (AC)) | |
733 | and then Ekind (Entity (Expression (AC))) = E_Constant | |
734 | and then Nkind (Parent (Entity (Expression (AC)))) | |
735 | = N_Object_Declaration) | |
0577b0b1 | 736 | then |
737 | Expr := New_Copy_Tree (Expression (AC)); | |
738 | else | |
739 | Remove_Side_Effects (Expr); | |
c2b56224 | 740 | end if; |
c2b56224 | 741 | |
0577b0b1 | 742 | Insert_After_And_Analyze (N, |
743 | Make_Raise_Program_Error (Loc, | |
744 | Condition => | |
745 | Make_Op_Ne (Loc, | |
746 | Left_Opnd => | |
747 | Make_Op_Mod (Loc, | |
748 | Left_Opnd => | |
749 | Unchecked_Convert_To | |
750 | (RTE (RE_Integer_Address), Expr), | |
751 | Right_Opnd => | |
752 | Make_Attribute_Reference (Loc, | |
753 | Prefix => New_Occurrence_Of (E, Loc), | |
754 | Attribute_Name => Name_Alignment)), | |
755 | Right_Opnd => Make_Integer_Literal (Loc, Uint_0)), | |
756 | Reason => PE_Misaligned_Address_Value), | |
757 | Suppress => All_Checks); | |
758 | return; | |
759 | end if; | |
9dfe12ae | 760 | |
761 | exception | |
0577b0b1 | 762 | -- If we have some missing run time component in configurable run time |
763 | -- mode then just skip the check (it is not required in any case). | |
764 | ||
9dfe12ae | 765 | when RE_Not_Available => |
766 | return; | |
0577b0b1 | 767 | end Apply_Address_Clause_Check; |
c2b56224 | 768 | |
ee6ba406 | 769 | ------------------------------------- |
770 | -- Apply_Arithmetic_Overflow_Check -- | |
771 | ------------------------------------- | |
772 | ||
f40f9731 | 773 | -- This routine is called only if the type is an integer type, and a |
774 | -- software arithmetic overflow check may be needed for op (add, subtract, | |
775 | -- or multiply). This check is performed only if Software_Overflow_Checking | |
776 | -- is enabled and Do_Overflow_Check is set. In this case we expand the | |
777 | -- operation into a more complex sequence of tests that ensures that | |
778 | -- overflow is properly caught. | |
ee6ba406 | 779 | |
780 | procedure Apply_Arithmetic_Overflow_Check (N : Node_Id) is | |
781 | Loc : constant Source_Ptr := Sloc (N); | |
f40f9731 | 782 | Typ : Entity_Id := Etype (N); |
783 | Rtyp : Entity_Id := Root_Type (Typ); | |
ee6ba406 | 784 | |
785 | begin | |
f40f9731 | 786 | -- An interesting special case. If the arithmetic operation appears as |
787 | -- the operand of a type conversion: | |
788 | ||
789 | -- type1 (x op y) | |
790 | ||
791 | -- and all the following conditions apply: | |
792 | ||
793 | -- arithmetic operation is for a signed integer type | |
794 | -- target type type1 is a static integer subtype | |
795 | -- range of x and y are both included in the range of type1 | |
796 | -- range of x op y is included in the range of type1 | |
797 | -- size of type1 is at least twice the result size of op | |
798 | ||
799 | -- then we don't do an overflow check in any case, instead we transform | |
800 | -- the operation so that we end up with: | |
801 | ||
802 | -- type1 (type1 (x) op type1 (y)) | |
803 | ||
804 | -- This avoids intermediate overflow before the conversion. It is | |
805 | -- explicitly permitted by RM 3.5.4(24): | |
806 | ||
807 | -- For the execution of a predefined operation of a signed integer | |
808 | -- type, the implementation need not raise Constraint_Error if the | |
809 | -- result is outside the base range of the type, so long as the | |
810 | -- correct result is produced. | |
811 | ||
812 | -- It's hard to imagine that any programmer counts on the exception | |
813 | -- being raised in this case, and in any case it's wrong coding to | |
814 | -- have this expectation, given the RM permission. Furthermore, other | |
815 | -- Ada compilers do allow such out of range results. | |
816 | ||
817 | -- Note that we do this transformation even if overflow checking is | |
818 | -- off, since this is precisely about giving the "right" result and | |
819 | -- avoiding the need for an overflow check. | |
820 | ||
821 | if Is_Signed_Integer_Type (Typ) | |
822 | and then Nkind (Parent (N)) = N_Type_Conversion | |
ee6ba406 | 823 | then |
f40f9731 | 824 | declare |
825 | Target_Type : constant Entity_Id := | |
826 | Base_Type (Entity (Subtype_Mark (Parent (N)))); | |
827 | ||
828 | Llo, Lhi : Uint; | |
829 | Rlo, Rhi : Uint; | |
830 | LOK, ROK : Boolean; | |
831 | ||
832 | Vlo : Uint; | |
833 | Vhi : Uint; | |
834 | VOK : Boolean; | |
835 | ||
836 | Tlo : Uint; | |
837 | Thi : Uint; | |
838 | ||
839 | begin | |
840 | if Is_Integer_Type (Target_Type) | |
841 | and then RM_Size (Root_Type (Target_Type)) >= 2 * RM_Size (Rtyp) | |
842 | then | |
843 | Tlo := Expr_Value (Type_Low_Bound (Target_Type)); | |
844 | Thi := Expr_Value (Type_High_Bound (Target_Type)); | |
845 | ||
9c486805 | 846 | Determine_Range |
847 | (Left_Opnd (N), LOK, Llo, Lhi, Assume_Valid => True); | |
848 | Determine_Range | |
849 | (Right_Opnd (N), ROK, Rlo, Rhi, Assume_Valid => True); | |
f40f9731 | 850 | |
851 | if (LOK and ROK) | |
852 | and then Tlo <= Llo and then Lhi <= Thi | |
853 | and then Tlo <= Rlo and then Rhi <= Thi | |
854 | then | |
9c486805 | 855 | Determine_Range (N, VOK, Vlo, Vhi, Assume_Valid => True); |
f40f9731 | 856 | |
857 | if VOK and then Tlo <= Vlo and then Vhi <= Thi then | |
858 | Rewrite (Left_Opnd (N), | |
859 | Make_Type_Conversion (Loc, | |
860 | Subtype_Mark => New_Occurrence_Of (Target_Type, Loc), | |
861 | Expression => Relocate_Node (Left_Opnd (N)))); | |
862 | ||
863 | Rewrite (Right_Opnd (N), | |
864 | Make_Type_Conversion (Loc, | |
865 | Subtype_Mark => New_Occurrence_Of (Target_Type, Loc), | |
866 | Expression => Relocate_Node (Right_Opnd (N)))); | |
867 | ||
868 | Set_Etype (N, Target_Type); | |
869 | Typ := Target_Type; | |
870 | Rtyp := Root_Type (Typ); | |
871 | Analyze_And_Resolve (Left_Opnd (N), Target_Type); | |
872 | Analyze_And_Resolve (Right_Opnd (N), Target_Type); | |
873 | ||
874 | -- Given that the target type is twice the size of the | |
875 | -- source type, overflow is now impossible, so we can | |
876 | -- safely kill the overflow check and return. | |
877 | ||
878 | Set_Do_Overflow_Check (N, False); | |
879 | return; | |
880 | end if; | |
881 | end if; | |
882 | end if; | |
883 | end; | |
ee6ba406 | 884 | end if; |
885 | ||
f40f9731 | 886 | -- Now see if an overflow check is required |
887 | ||
888 | declare | |
889 | Siz : constant Int := UI_To_Int (Esize (Rtyp)); | |
890 | Dsiz : constant Int := Siz * 2; | |
891 | Opnod : Node_Id; | |
892 | Ctyp : Entity_Id; | |
893 | Opnd : Node_Id; | |
894 | Cent : RE_Id; | |
ee6ba406 | 895 | |
f40f9731 | 896 | begin |
897 | -- Skip check if back end does overflow checks, or the overflow flag | |
898 | -- is not set anyway, or we are not doing code expansion. | |
ee6ba406 | 899 | |
f40f9731 | 900 | -- Special case CLI target, where arithmetic overflow checks can be |
901 | -- performed for integer and long_integer | |
ee6ba406 | 902 | |
f40f9731 | 903 | if Backend_Overflow_Checks_On_Target |
904 | or else not Do_Overflow_Check (N) | |
905 | or else not Expander_Active | |
906 | or else | |
907 | (VM_Target = CLI_Target and then Siz >= Standard_Integer_Size) | |
908 | then | |
909 | return; | |
910 | end if; | |
ee6ba406 | 911 | |
f40f9731 | 912 | -- Otherwise, generate the full general code for front end overflow |
913 | -- detection, which works by doing arithmetic in a larger type: | |
ee6ba406 | 914 | |
f40f9731 | 915 | -- x op y |
ee6ba406 | 916 | |
f40f9731 | 917 | -- is expanded into |
ee6ba406 | 918 | |
f40f9731 | 919 | -- Typ (Checktyp (x) op Checktyp (y)); |
ee6ba406 | 920 | |
f40f9731 | 921 | -- where Typ is the type of the original expression, and Checktyp is |
922 | -- an integer type of sufficient length to hold the largest possible | |
923 | -- result. | |
ee6ba406 | 924 | |
f40f9731 | 925 | -- If the size of check type exceeds the size of Long_Long_Integer, |
926 | -- we use a different approach, expanding to: | |
ee6ba406 | 927 | |
f40f9731 | 928 | -- typ (xxx_With_Ovflo_Check (Integer_64 (x), Integer (y))) |
ee6ba406 | 929 | |
f40f9731 | 930 | -- where xxx is Add, Multiply or Subtract as appropriate |
ee6ba406 | 931 | |
f40f9731 | 932 | -- Find check type if one exists |
933 | ||
934 | if Dsiz <= Standard_Integer_Size then | |
935 | Ctyp := Standard_Integer; | |
ee6ba406 | 936 | |
f40f9731 | 937 | elsif Dsiz <= Standard_Long_Long_Integer_Size then |
938 | Ctyp := Standard_Long_Long_Integer; | |
939 | ||
940 | -- No check type exists, use runtime call | |
ee6ba406 | 941 | |
942 | else | |
f40f9731 | 943 | if Nkind (N) = N_Op_Add then |
944 | Cent := RE_Add_With_Ovflo_Check; | |
ee6ba406 | 945 | |
f40f9731 | 946 | elsif Nkind (N) = N_Op_Multiply then |
947 | Cent := RE_Multiply_With_Ovflo_Check; | |
ee6ba406 | 948 | |
f40f9731 | 949 | else |
950 | pragma Assert (Nkind (N) = N_Op_Subtract); | |
951 | Cent := RE_Subtract_With_Ovflo_Check; | |
952 | end if; | |
953 | ||
954 | Rewrite (N, | |
955 | OK_Convert_To (Typ, | |
956 | Make_Function_Call (Loc, | |
957 | Name => New_Reference_To (RTE (Cent), Loc), | |
958 | Parameter_Associations => New_List ( | |
959 | OK_Convert_To (RTE (RE_Integer_64), Left_Opnd (N)), | |
960 | OK_Convert_To (RTE (RE_Integer_64), Right_Opnd (N)))))); | |
ee6ba406 | 961 | |
f40f9731 | 962 | Analyze_And_Resolve (N, Typ); |
963 | return; | |
964 | end if; | |
ee6ba406 | 965 | |
f40f9731 | 966 | -- If we fall through, we have the case where we do the arithmetic |
967 | -- in the next higher type and get the check by conversion. In these | |
968 | -- cases Ctyp is set to the type to be used as the check type. | |
ee6ba406 | 969 | |
f40f9731 | 970 | Opnod := Relocate_Node (N); |
ee6ba406 | 971 | |
f40f9731 | 972 | Opnd := OK_Convert_To (Ctyp, Left_Opnd (Opnod)); |
ee6ba406 | 973 | |
f40f9731 | 974 | Analyze (Opnd); |
975 | Set_Etype (Opnd, Ctyp); | |
976 | Set_Analyzed (Opnd, True); | |
977 | Set_Left_Opnd (Opnod, Opnd); | |
ee6ba406 | 978 | |
f40f9731 | 979 | Opnd := OK_Convert_To (Ctyp, Right_Opnd (Opnod)); |
ee6ba406 | 980 | |
f40f9731 | 981 | Analyze (Opnd); |
982 | Set_Etype (Opnd, Ctyp); | |
983 | Set_Analyzed (Opnd, True); | |
984 | Set_Right_Opnd (Opnod, Opnd); | |
ee6ba406 | 985 | |
f40f9731 | 986 | -- The type of the operation changes to the base type of the check |
987 | -- type, and we reset the overflow check indication, since clearly no | |
988 | -- overflow is possible now that we are using a double length type. | |
989 | -- We also set the Analyzed flag to avoid a recursive attempt to | |
990 | -- expand the node. | |
ee6ba406 | 991 | |
f40f9731 | 992 | Set_Etype (Opnod, Base_Type (Ctyp)); |
993 | Set_Do_Overflow_Check (Opnod, False); | |
994 | Set_Analyzed (Opnod, True); | |
ee6ba406 | 995 | |
f40f9731 | 996 | -- Now build the outer conversion |
ee6ba406 | 997 | |
f40f9731 | 998 | Opnd := OK_Convert_To (Typ, Opnod); |
999 | Analyze (Opnd); | |
1000 | Set_Etype (Opnd, Typ); | |
9dfe12ae | 1001 | |
f40f9731 | 1002 | -- In the discrete type case, we directly generate the range check |
1003 | -- for the outer operand. This range check will implement the | |
1004 | -- required overflow check. | |
9dfe12ae | 1005 | |
f40f9731 | 1006 | if Is_Discrete_Type (Typ) then |
1007 | Rewrite (N, Opnd); | |
1008 | Generate_Range_Check | |
1009 | (Expression (N), Typ, CE_Overflow_Check_Failed); | |
9dfe12ae | 1010 | |
f40f9731 | 1011 | -- For other types, we enable overflow checking on the conversion, |
1012 | -- after setting the node as analyzed to prevent recursive attempts | |
1013 | -- to expand the conversion node. | |
9dfe12ae | 1014 | |
f40f9731 | 1015 | else |
1016 | Set_Analyzed (Opnd, True); | |
1017 | Enable_Overflow_Check (Opnd); | |
1018 | Rewrite (N, Opnd); | |
1019 | end if; | |
1020 | ||
1021 | exception | |
1022 | when RE_Not_Available => | |
1023 | return; | |
1024 | end; | |
ee6ba406 | 1025 | end Apply_Arithmetic_Overflow_Check; |
1026 | ||
ee6ba406 | 1027 | ---------------------------- |
1028 | -- Apply_Constraint_Check -- | |
1029 | ---------------------------- | |
1030 | ||
1031 | procedure Apply_Constraint_Check | |
1032 | (N : Node_Id; | |
1033 | Typ : Entity_Id; | |
1034 | No_Sliding : Boolean := False) | |
1035 | is | |
1036 | Desig_Typ : Entity_Id; | |
1037 | ||
1038 | begin | |
1039 | if Inside_A_Generic then | |
1040 | return; | |
1041 | ||
1042 | elsif Is_Scalar_Type (Typ) then | |
1043 | Apply_Scalar_Range_Check (N, Typ); | |
1044 | ||
1045 | elsif Is_Array_Type (Typ) then | |
1046 | ||
05fcfafb | 1047 | -- A useful optimization: an aggregate with only an others clause |
5f260d20 | 1048 | -- always has the right bounds. |
1049 | ||
1050 | if Nkind (N) = N_Aggregate | |
1051 | and then No (Expressions (N)) | |
1052 | and then Nkind | |
1053 | (First (Choices (First (Component_Associations (N))))) | |
1054 | = N_Others_Choice | |
1055 | then | |
1056 | return; | |
1057 | end if; | |
1058 | ||
ee6ba406 | 1059 | if Is_Constrained (Typ) then |
1060 | Apply_Length_Check (N, Typ); | |
1061 | ||
1062 | if No_Sliding then | |
1063 | Apply_Range_Check (N, Typ); | |
1064 | end if; | |
1065 | else | |
1066 | Apply_Range_Check (N, Typ); | |
1067 | end if; | |
1068 | ||
1069 | elsif (Is_Record_Type (Typ) | |
1070 | or else Is_Private_Type (Typ)) | |
1071 | and then Has_Discriminants (Base_Type (Typ)) | |
1072 | and then Is_Constrained (Typ) | |
1073 | then | |
1074 | Apply_Discriminant_Check (N, Typ); | |
1075 | ||
1076 | elsif Is_Access_Type (Typ) then | |
1077 | ||
1078 | Desig_Typ := Designated_Type (Typ); | |
1079 | ||
1080 | -- No checks necessary if expression statically null | |
1081 | ||
2af58f67 | 1082 | if Known_Null (N) then |
00c403ee | 1083 | if Can_Never_Be_Null (Typ) then |
1084 | Install_Null_Excluding_Check (N); | |
1085 | end if; | |
ee6ba406 | 1086 | |
1087 | -- No sliding possible on access to arrays | |
1088 | ||
1089 | elsif Is_Array_Type (Desig_Typ) then | |
1090 | if Is_Constrained (Desig_Typ) then | |
1091 | Apply_Length_Check (N, Typ); | |
1092 | end if; | |
1093 | ||
1094 | Apply_Range_Check (N, Typ); | |
1095 | ||
1096 | elsif Has_Discriminants (Base_Type (Desig_Typ)) | |
1097 | and then Is_Constrained (Desig_Typ) | |
1098 | then | |
1099 | Apply_Discriminant_Check (N, Typ); | |
1100 | end if; | |
fa7497e8 | 1101 | |
bf3e1520 | 1102 | -- Apply the 2005 Null_Excluding check. Note that we do not apply |
00c403ee | 1103 | -- this check if the constraint node is illegal, as shown by having |
1104 | -- an error posted. This additional guard prevents cascaded errors | |
1105 | -- and compiler aborts on illegal programs involving Ada 2005 checks. | |
1106 | ||
fa7497e8 | 1107 | if Can_Never_Be_Null (Typ) |
1108 | and then not Can_Never_Be_Null (Etype (N)) | |
00c403ee | 1109 | and then not Error_Posted (N) |
fa7497e8 | 1110 | then |
1111 | Install_Null_Excluding_Check (N); | |
1112 | end if; | |
ee6ba406 | 1113 | end if; |
1114 | end Apply_Constraint_Check; | |
1115 | ||
1116 | ------------------------------ | |
1117 | -- Apply_Discriminant_Check -- | |
1118 | ------------------------------ | |
1119 | ||
1120 | procedure Apply_Discriminant_Check | |
1121 | (N : Node_Id; | |
1122 | Typ : Entity_Id; | |
1123 | Lhs : Node_Id := Empty) | |
1124 | is | |
1125 | Loc : constant Source_Ptr := Sloc (N); | |
1126 | Do_Access : constant Boolean := Is_Access_Type (Typ); | |
1127 | S_Typ : Entity_Id := Etype (N); | |
1128 | Cond : Node_Id; | |
1129 | T_Typ : Entity_Id; | |
1130 | ||
1131 | function Is_Aliased_Unconstrained_Component return Boolean; | |
1132 | -- It is possible for an aliased component to have a nominal | |
1133 | -- unconstrained subtype (through instantiation). If this is a | |
1134 | -- discriminated component assigned in the expansion of an aggregate | |
1135 | -- in an initialization, the check must be suppressed. This unusual | |
2af58f67 | 1136 | -- situation requires a predicate of its own. |
ee6ba406 | 1137 | |
1138 | ---------------------------------------- | |
1139 | -- Is_Aliased_Unconstrained_Component -- | |
1140 | ---------------------------------------- | |
1141 | ||
1142 | function Is_Aliased_Unconstrained_Component return Boolean is | |
1143 | Comp : Entity_Id; | |
1144 | Pref : Node_Id; | |
1145 | ||
1146 | begin | |
1147 | if Nkind (Lhs) /= N_Selected_Component then | |
1148 | return False; | |
1149 | else | |
1150 | Comp := Entity (Selector_Name (Lhs)); | |
1151 | Pref := Prefix (Lhs); | |
1152 | end if; | |
1153 | ||
1154 | if Ekind (Comp) /= E_Component | |
1155 | or else not Is_Aliased (Comp) | |
1156 | then | |
1157 | return False; | |
1158 | end if; | |
1159 | ||
1160 | return not Comes_From_Source (Pref) | |
1161 | and then In_Instance | |
1162 | and then not Is_Constrained (Etype (Comp)); | |
1163 | end Is_Aliased_Unconstrained_Component; | |
1164 | ||
1165 | -- Start of processing for Apply_Discriminant_Check | |
1166 | ||
1167 | begin | |
1168 | if Do_Access then | |
1169 | T_Typ := Designated_Type (Typ); | |
1170 | else | |
1171 | T_Typ := Typ; | |
1172 | end if; | |
1173 | ||
1174 | -- Nothing to do if discriminant checks are suppressed or else no code | |
1175 | -- is to be generated | |
1176 | ||
1177 | if not Expander_Active | |
1178 | or else Discriminant_Checks_Suppressed (T_Typ) | |
1179 | then | |
1180 | return; | |
1181 | end if; | |
1182 | ||
feff2f05 | 1183 | -- No discriminant checks necessary for an access when expression is |
1184 | -- statically Null. This is not only an optimization, it is fundamental | |
1185 | -- because otherwise discriminant checks may be generated in init procs | |
1186 | -- for types containing an access to a not-yet-frozen record, causing a | |
1187 | -- deadly forward reference. | |
ee6ba406 | 1188 | |
feff2f05 | 1189 | -- Also, if the expression is of an access type whose designated type is |
1190 | -- incomplete, then the access value must be null and we suppress the | |
1191 | -- check. | |
ee6ba406 | 1192 | |
2af58f67 | 1193 | if Known_Null (N) then |
ee6ba406 | 1194 | return; |
1195 | ||
1196 | elsif Is_Access_Type (S_Typ) then | |
1197 | S_Typ := Designated_Type (S_Typ); | |
1198 | ||
1199 | if Ekind (S_Typ) = E_Incomplete_Type then | |
1200 | return; | |
1201 | end if; | |
1202 | end if; | |
1203 | ||
0577b0b1 | 1204 | -- If an assignment target is present, then we need to generate the |
1205 | -- actual subtype if the target is a parameter or aliased object with | |
1206 | -- an unconstrained nominal subtype. | |
1207 | ||
1208 | -- Ada 2005 (AI-363): For Ada 2005, we limit the building of the actual | |
1209 | -- subtype to the parameter and dereference cases, since other aliased | |
1210 | -- objects are unconstrained (unless the nominal subtype is explicitly | |
1211 | -- constrained). (But we also need to test for renamings???) | |
ee6ba406 | 1212 | |
1213 | if Present (Lhs) | |
1214 | and then (Present (Param_Entity (Lhs)) | |
0577b0b1 | 1215 | or else (Ada_Version < Ada_05 |
1216 | and then not Is_Constrained (T_Typ) | |
ee6ba406 | 1217 | and then Is_Aliased_View (Lhs) |
0577b0b1 | 1218 | and then not Is_Aliased_Unconstrained_Component) |
1219 | or else (Ada_Version >= Ada_05 | |
1220 | and then not Is_Constrained (T_Typ) | |
1221 | and then Nkind (Lhs) = N_Explicit_Dereference | |
1222 | and then Nkind (Original_Node (Lhs)) /= | |
1223 | N_Function_Call)) | |
ee6ba406 | 1224 | then |
1225 | T_Typ := Get_Actual_Subtype (Lhs); | |
1226 | end if; | |
1227 | ||
feff2f05 | 1228 | -- Nothing to do if the type is unconstrained (this is the case where |
1229 | -- the actual subtype in the RM sense of N is unconstrained and no check | |
1230 | -- is required). | |
ee6ba406 | 1231 | |
1232 | if not Is_Constrained (T_Typ) then | |
1233 | return; | |
05fcfafb | 1234 | |
1235 | -- Ada 2005: nothing to do if the type is one for which there is a | |
1236 | -- partial view that is constrained. | |
1237 | ||
1238 | elsif Ada_Version >= Ada_05 | |
1239 | and then Has_Constrained_Partial_View (Base_Type (T_Typ)) | |
1240 | then | |
1241 | return; | |
ee6ba406 | 1242 | end if; |
1243 | ||
00f91aef | 1244 | -- Nothing to do if the type is an Unchecked_Union |
1245 | ||
1246 | if Is_Unchecked_Union (Base_Type (T_Typ)) then | |
1247 | return; | |
1248 | end if; | |
1249 | ||
feff2f05 | 1250 | -- Suppress checks if the subtypes are the same. the check must be |
1251 | -- preserved in an assignment to a formal, because the constraint is | |
1252 | -- given by the actual. | |
ee6ba406 | 1253 | |
1254 | if Nkind (Original_Node (N)) /= N_Allocator | |
1255 | and then (No (Lhs) | |
1256 | or else not Is_Entity_Name (Lhs) | |
9dfe12ae | 1257 | or else No (Param_Entity (Lhs))) |
ee6ba406 | 1258 | then |
1259 | if (Etype (N) = Typ | |
1260 | or else (Do_Access and then Designated_Type (Typ) = S_Typ)) | |
1261 | and then not Is_Aliased_View (Lhs) | |
1262 | then | |
1263 | return; | |
1264 | end if; | |
1265 | ||
feff2f05 | 1266 | -- We can also eliminate checks on allocators with a subtype mark that |
1267 | -- coincides with the context type. The context type may be a subtype | |
1268 | -- without a constraint (common case, a generic actual). | |
ee6ba406 | 1269 | |
1270 | elsif Nkind (Original_Node (N)) = N_Allocator | |
1271 | and then Is_Entity_Name (Expression (Original_Node (N))) | |
1272 | then | |
1273 | declare | |
9dfe12ae | 1274 | Alloc_Typ : constant Entity_Id := |
1275 | Entity (Expression (Original_Node (N))); | |
ee6ba406 | 1276 | |
1277 | begin | |
1278 | if Alloc_Typ = T_Typ | |
1279 | or else (Nkind (Parent (T_Typ)) = N_Subtype_Declaration | |
1280 | and then Is_Entity_Name ( | |
1281 | Subtype_Indication (Parent (T_Typ))) | |
1282 | and then Alloc_Typ = Base_Type (T_Typ)) | |
1283 | ||
1284 | then | |
1285 | return; | |
1286 | end if; | |
1287 | end; | |
1288 | end if; | |
1289 | ||
feff2f05 | 1290 | -- See if we have a case where the types are both constrained, and all |
1291 | -- the constraints are constants. In this case, we can do the check | |
1292 | -- successfully at compile time. | |
ee6ba406 | 1293 | |
9dfe12ae | 1294 | -- We skip this check for the case where the node is a rewritten` |
ee6ba406 | 1295 | -- allocator, because it already carries the context subtype, and |
1296 | -- extracting the discriminants from the aggregate is messy. | |
1297 | ||
1298 | if Is_Constrained (S_Typ) | |
1299 | and then Nkind (Original_Node (N)) /= N_Allocator | |
1300 | then | |
1301 | declare | |
1302 | DconT : Elmt_Id; | |
1303 | Discr : Entity_Id; | |
1304 | DconS : Elmt_Id; | |
1305 | ItemS : Node_Id; | |
1306 | ItemT : Node_Id; | |
1307 | ||
1308 | begin | |
1309 | -- S_Typ may not have discriminants in the case where it is a | |
feff2f05 | 1310 | -- private type completed by a default discriminated type. In that |
1311 | -- case, we need to get the constraints from the underlying_type. | |
1312 | -- If the underlying type is unconstrained (i.e. has no default | |
1313 | -- discriminants) no check is needed. | |
ee6ba406 | 1314 | |
1315 | if Has_Discriminants (S_Typ) then | |
1316 | Discr := First_Discriminant (S_Typ); | |
1317 | DconS := First_Elmt (Discriminant_Constraint (S_Typ)); | |
1318 | ||
1319 | else | |
1320 | Discr := First_Discriminant (Underlying_Type (S_Typ)); | |
1321 | DconS := | |
1322 | First_Elmt | |
1323 | (Discriminant_Constraint (Underlying_Type (S_Typ))); | |
1324 | ||
1325 | if No (DconS) then | |
1326 | return; | |
1327 | end if; | |
fccb5da7 | 1328 | |
1329 | -- A further optimization: if T_Typ is derived from S_Typ | |
1330 | -- without imposing a constraint, no check is needed. | |
1331 | ||
1332 | if Nkind (Original_Node (Parent (T_Typ))) = | |
1333 | N_Full_Type_Declaration | |
1334 | then | |
1335 | declare | |
5c61a0ff | 1336 | Type_Def : constant Node_Id := |
fccb5da7 | 1337 | Type_Definition |
1338 | (Original_Node (Parent (T_Typ))); | |
1339 | begin | |
1340 | if Nkind (Type_Def) = N_Derived_Type_Definition | |
1341 | and then Is_Entity_Name (Subtype_Indication (Type_Def)) | |
1342 | and then Entity (Subtype_Indication (Type_Def)) = S_Typ | |
1343 | then | |
1344 | return; | |
1345 | end if; | |
1346 | end; | |
1347 | end if; | |
ee6ba406 | 1348 | end if; |
1349 | ||
1350 | DconT := First_Elmt (Discriminant_Constraint (T_Typ)); | |
1351 | ||
1352 | while Present (Discr) loop | |
1353 | ItemS := Node (DconS); | |
1354 | ItemT := Node (DconT); | |
1355 | ||
00c403ee | 1356 | -- For a discriminated component type constrained by the |
1357 | -- current instance of an enclosing type, there is no | |
1358 | -- applicable discriminant check. | |
1359 | ||
1360 | if Nkind (ItemT) = N_Attribute_Reference | |
1361 | and then Is_Access_Type (Etype (ItemT)) | |
1362 | and then Is_Entity_Name (Prefix (ItemT)) | |
1363 | and then Is_Type (Entity (Prefix (ItemT))) | |
1364 | then | |
1365 | return; | |
1366 | end if; | |
1367 | ||
cc60bd16 | 1368 | -- If the expressions for the discriminants are identical |
1369 | -- and it is side-effect free (for now just an entity), | |
1370 | -- this may be a shared constraint, e.g. from a subtype | |
1371 | -- without a constraint introduced as a generic actual. | |
1372 | -- Examine other discriminants if any. | |
1373 | ||
1374 | if ItemS = ItemT | |
1375 | and then Is_Entity_Name (ItemS) | |
1376 | then | |
1377 | null; | |
1378 | ||
1379 | elsif not Is_OK_Static_Expression (ItemS) | |
1380 | or else not Is_OK_Static_Expression (ItemT) | |
1381 | then | |
1382 | exit; | |
ee6ba406 | 1383 | |
cc60bd16 | 1384 | elsif Expr_Value (ItemS) /= Expr_Value (ItemT) then |
ee6ba406 | 1385 | if Do_Access then -- needs run-time check. |
1386 | exit; | |
1387 | else | |
1388 | Apply_Compile_Time_Constraint_Error | |
f15731c4 | 1389 | (N, "incorrect value for discriminant&?", |
1390 | CE_Discriminant_Check_Failed, Ent => Discr); | |
ee6ba406 | 1391 | return; |
1392 | end if; | |
1393 | end if; | |
1394 | ||
1395 | Next_Elmt (DconS); | |
1396 | Next_Elmt (DconT); | |
1397 | Next_Discriminant (Discr); | |
1398 | end loop; | |
1399 | ||
1400 | if No (Discr) then | |
1401 | return; | |
1402 | end if; | |
1403 | end; | |
1404 | end if; | |
1405 | ||
1406 | -- Here we need a discriminant check. First build the expression | |
1407 | -- for the comparisons of the discriminants: | |
1408 | ||
1409 | -- (n.disc1 /= typ.disc1) or else | |
1410 | -- (n.disc2 /= typ.disc2) or else | |
1411 | -- ... | |
1412 | -- (n.discn /= typ.discn) | |
1413 | ||
1414 | Cond := Build_Discriminant_Checks (N, T_Typ); | |
1415 | ||
1416 | -- If Lhs is set and is a parameter, then the condition is | |
1417 | -- guarded by: lhs'constrained and then (condition built above) | |
1418 | ||
1419 | if Present (Param_Entity (Lhs)) then | |
1420 | Cond := | |
1421 | Make_And_Then (Loc, | |
1422 | Left_Opnd => | |
1423 | Make_Attribute_Reference (Loc, | |
1424 | Prefix => New_Occurrence_Of (Param_Entity (Lhs), Loc), | |
1425 | Attribute_Name => Name_Constrained), | |
1426 | Right_Opnd => Cond); | |
1427 | end if; | |
1428 | ||
1429 | if Do_Access then | |
1430 | Cond := Guard_Access (Cond, Loc, N); | |
1431 | end if; | |
1432 | ||
1433 | Insert_Action (N, | |
f15731c4 | 1434 | Make_Raise_Constraint_Error (Loc, |
1435 | Condition => Cond, | |
1436 | Reason => CE_Discriminant_Check_Failed)); | |
ee6ba406 | 1437 | end Apply_Discriminant_Check; |
1438 | ||
1439 | ------------------------ | |
1440 | -- Apply_Divide_Check -- | |
1441 | ------------------------ | |
1442 | ||
1443 | procedure Apply_Divide_Check (N : Node_Id) is | |
1444 | Loc : constant Source_Ptr := Sloc (N); | |
1445 | Typ : constant Entity_Id := Etype (N); | |
1446 | Left : constant Node_Id := Left_Opnd (N); | |
1447 | Right : constant Node_Id := Right_Opnd (N); | |
1448 | ||
1449 | LLB : Uint; | |
1450 | Llo : Uint; | |
1451 | Lhi : Uint; | |
1452 | LOK : Boolean; | |
1453 | Rlo : Uint; | |
1454 | Rhi : Uint; | |
96da3284 | 1455 | ROK : Boolean; |
1456 | ||
1457 | pragma Warnings (Off, Lhi); | |
1458 | -- Don't actually use this value | |
ee6ba406 | 1459 | |
1460 | begin | |
1461 | if Expander_Active | |
13dbf220 | 1462 | and then not Backend_Divide_Checks_On_Target |
1463 | and then Check_Needed (Right, Division_Check) | |
ee6ba406 | 1464 | then |
9c486805 | 1465 | Determine_Range (Right, ROK, Rlo, Rhi, Assume_Valid => True); |
ee6ba406 | 1466 | |
1467 | -- See if division by zero possible, and if so generate test. This | |
1468 | -- part of the test is not controlled by the -gnato switch. | |
1469 | ||
1470 | if Do_Division_Check (N) then | |
ee6ba406 | 1471 | if (not ROK) or else (Rlo <= 0 and then 0 <= Rhi) then |
1472 | Insert_Action (N, | |
1473 | Make_Raise_Constraint_Error (Loc, | |
1474 | Condition => | |
1475 | Make_Op_Eq (Loc, | |
0577b0b1 | 1476 | Left_Opnd => Duplicate_Subexpr_Move_Checks (Right), |
f15731c4 | 1477 | Right_Opnd => Make_Integer_Literal (Loc, 0)), |
1478 | Reason => CE_Divide_By_Zero)); | |
ee6ba406 | 1479 | end if; |
1480 | end if; | |
1481 | ||
1482 | -- Test for extremely annoying case of xxx'First divided by -1 | |
1483 | ||
1484 | if Do_Overflow_Check (N) then | |
ee6ba406 | 1485 | if Nkind (N) = N_Op_Divide |
1486 | and then Is_Signed_Integer_Type (Typ) | |
1487 | then | |
9c486805 | 1488 | Determine_Range (Left, LOK, Llo, Lhi, Assume_Valid => True); |
ee6ba406 | 1489 | LLB := Expr_Value (Type_Low_Bound (Base_Type (Typ))); |
1490 | ||
1491 | if ((not ROK) or else (Rlo <= (-1) and then (-1) <= Rhi)) | |
1492 | and then | |
1493 | ((not LOK) or else (Llo = LLB)) | |
1494 | then | |
1495 | Insert_Action (N, | |
1496 | Make_Raise_Constraint_Error (Loc, | |
1497 | Condition => | |
1498 | Make_And_Then (Loc, | |
1499 | ||
1500 | Make_Op_Eq (Loc, | |
9dfe12ae | 1501 | Left_Opnd => |
1502 | Duplicate_Subexpr_Move_Checks (Left), | |
ee6ba406 | 1503 | Right_Opnd => Make_Integer_Literal (Loc, LLB)), |
1504 | ||
1505 | Make_Op_Eq (Loc, | |
9dfe12ae | 1506 | Left_Opnd => |
1507 | Duplicate_Subexpr (Right), | |
ee6ba406 | 1508 | Right_Opnd => |
f15731c4 | 1509 | Make_Integer_Literal (Loc, -1))), |
1510 | Reason => CE_Overflow_Check_Failed)); | |
ee6ba406 | 1511 | end if; |
1512 | end if; | |
1513 | end if; | |
1514 | end if; | |
1515 | end Apply_Divide_Check; | |
1516 | ||
5329ca64 | 1517 | ---------------------------------- |
1518 | -- Apply_Float_Conversion_Check -- | |
1519 | ---------------------------------- | |
1520 | ||
feff2f05 | 1521 | -- Let F and I be the source and target types of the conversion. The RM |
1522 | -- specifies that a floating-point value X is rounded to the nearest | |
1523 | -- integer, with halfway cases being rounded away from zero. The rounded | |
1524 | -- value of X is checked against I'Range. | |
1525 | ||
1526 | -- The catch in the above paragraph is that there is no good way to know | |
1527 | -- whether the round-to-integer operation resulted in overflow. A remedy is | |
1528 | -- to perform a range check in the floating-point domain instead, however: | |
5329ca64 | 1529 | |
5329ca64 | 1530 | -- (1) The bounds may not be known at compile time |
2af58f67 | 1531 | -- (2) The check must take into account rounding or truncation. |
5329ca64 | 1532 | -- (3) The range of type I may not be exactly representable in F. |
2af58f67 | 1533 | -- (4) For the rounding case, The end-points I'First - 0.5 and |
1534 | -- I'Last + 0.5 may or may not be in range, depending on the | |
1535 | -- sign of I'First and I'Last. | |
5329ca64 | 1536 | -- (5) X may be a NaN, which will fail any comparison |
1537 | ||
2af58f67 | 1538 | -- The following steps correctly convert X with rounding: |
feff2f05 | 1539 | |
5329ca64 | 1540 | -- (1) If either I'First or I'Last is not known at compile time, use |
1541 | -- I'Base instead of I in the next three steps and perform a | |
1542 | -- regular range check against I'Range after conversion. | |
1543 | -- (2) If I'First - 0.5 is representable in F then let Lo be that | |
1544 | -- value and define Lo_OK as (I'First > 0). Otherwise, let Lo be | |
2af58f67 | 1545 | -- F'Machine (I'First) and let Lo_OK be (Lo >= I'First). |
1546 | -- In other words, take one of the closest floating-point numbers | |
1547 | -- (which is an integer value) to I'First, and see if it is in | |
1548 | -- range or not. | |
5329ca64 | 1549 | -- (3) If I'Last + 0.5 is representable in F then let Hi be that value |
1550 | -- and define Hi_OK as (I'Last < 0). Otherwise, let Hi be | |
2af58f67 | 1551 | -- F'Machine (I'Last) and let Hi_OK be (Hi <= I'Last). |
5329ca64 | 1552 | -- (4) Raise CE when (Lo_OK and X < Lo) or (not Lo_OK and X <= Lo) |
1553 | -- or (Hi_OK and X > Hi) or (not Hi_OK and X >= Hi) | |
1554 | ||
2af58f67 | 1555 | -- For the truncating case, replace steps (2) and (3) as follows: |
1556 | -- (2) If I'First > 0, then let Lo be F'Pred (I'First) and let Lo_OK | |
1557 | -- be False. Otherwise, let Lo be F'Succ (I'First - 1) and let | |
1558 | -- Lo_OK be True. | |
1559 | -- (3) If I'Last < 0, then let Hi be F'Succ (I'Last) and let Hi_OK | |
1560 | -- be False. Otherwise let Hi be F'Pred (I'Last + 1) and let | |
1561 | -- Hi_OK be False | |
1562 | ||
5329ca64 | 1563 | procedure Apply_Float_Conversion_Check |
1564 | (Ck_Node : Node_Id; | |
1565 | Target_Typ : Entity_Id) | |
1566 | is | |
feff2f05 | 1567 | LB : constant Node_Id := Type_Low_Bound (Target_Typ); |
1568 | HB : constant Node_Id := Type_High_Bound (Target_Typ); | |
5329ca64 | 1569 | Loc : constant Source_Ptr := Sloc (Ck_Node); |
1570 | Expr_Type : constant Entity_Id := Base_Type (Etype (Ck_Node)); | |
feff2f05 | 1571 | Target_Base : constant Entity_Id := |
1572 | Implementation_Base_Type (Target_Typ); | |
1573 | ||
2af58f67 | 1574 | Par : constant Node_Id := Parent (Ck_Node); |
1575 | pragma Assert (Nkind (Par) = N_Type_Conversion); | |
1576 | -- Parent of check node, must be a type conversion | |
1577 | ||
1578 | Truncate : constant Boolean := Float_Truncate (Par); | |
1579 | Max_Bound : constant Uint := | |
1580 | UI_Expon | |
1581 | (Machine_Radix (Expr_Type), | |
1582 | Machine_Mantissa (Expr_Type) - 1) - 1; | |
1583 | ||
5329ca64 | 1584 | -- Largest bound, so bound plus or minus half is a machine number of F |
1585 | ||
feff2f05 | 1586 | Ifirst, Ilast : Uint; |
1587 | -- Bounds of integer type | |
1588 | ||
1589 | Lo, Hi : Ureal; | |
1590 | -- Bounds to check in floating-point domain | |
5329ca64 | 1591 | |
feff2f05 | 1592 | Lo_OK, Hi_OK : Boolean; |
1593 | -- True iff Lo resp. Hi belongs to I'Range | |
5329ca64 | 1594 | |
feff2f05 | 1595 | Lo_Chk, Hi_Chk : Node_Id; |
1596 | -- Expressions that are False iff check fails | |
1597 | ||
1598 | Reason : RT_Exception_Code; | |
5329ca64 | 1599 | |
1600 | begin | |
1601 | if not Compile_Time_Known_Value (LB) | |
1602 | or not Compile_Time_Known_Value (HB) | |
1603 | then | |
1604 | declare | |
feff2f05 | 1605 | -- First check that the value falls in the range of the base type, |
1606 | -- to prevent overflow during conversion and then perform a | |
1607 | -- regular range check against the (dynamic) bounds. | |
5329ca64 | 1608 | |
5329ca64 | 1609 | pragma Assert (Target_Base /= Target_Typ); |
5329ca64 | 1610 | |
1611 | Temp : constant Entity_Id := | |
1612 | Make_Defining_Identifier (Loc, | |
1613 | Chars => New_Internal_Name ('T')); | |
1614 | ||
1615 | begin | |
1616 | Apply_Float_Conversion_Check (Ck_Node, Target_Base); | |
1617 | Set_Etype (Temp, Target_Base); | |
1618 | ||
1619 | Insert_Action (Parent (Par), | |
1620 | Make_Object_Declaration (Loc, | |
1621 | Defining_Identifier => Temp, | |
1622 | Object_Definition => New_Occurrence_Of (Target_Typ, Loc), | |
1623 | Expression => New_Copy_Tree (Par)), | |
1624 | Suppress => All_Checks); | |
1625 | ||
1626 | Insert_Action (Par, | |
1627 | Make_Raise_Constraint_Error (Loc, | |
1628 | Condition => | |
1629 | Make_Not_In (Loc, | |
1630 | Left_Opnd => New_Occurrence_Of (Temp, Loc), | |
1631 | Right_Opnd => New_Occurrence_Of (Target_Typ, Loc)), | |
1632 | Reason => CE_Range_Check_Failed)); | |
1633 | Rewrite (Par, New_Occurrence_Of (Temp, Loc)); | |
1634 | ||
1635 | return; | |
1636 | end; | |
1637 | end if; | |
1638 | ||
7d86aa98 | 1639 | -- Get the (static) bounds of the target type |
5329ca64 | 1640 | |
1641 | Ifirst := Expr_Value (LB); | |
1642 | Ilast := Expr_Value (HB); | |
1643 | ||
7d86aa98 | 1644 | -- A simple optimization: if the expression is a universal literal, |
1645 | -- we can do the comparison with the bounds and the conversion to | |
1646 | -- an integer type statically. The range checks are unchanged. | |
1647 | ||
1648 | if Nkind (Ck_Node) = N_Real_Literal | |
1649 | and then Etype (Ck_Node) = Universal_Real | |
1650 | and then Is_Integer_Type (Target_Typ) | |
1651 | and then Nkind (Parent (Ck_Node)) = N_Type_Conversion | |
1652 | then | |
1653 | declare | |
1654 | Int_Val : constant Uint := UR_To_Uint (Realval (Ck_Node)); | |
1655 | ||
1656 | begin | |
1657 | if Int_Val <= Ilast and then Int_Val >= Ifirst then | |
1658 | ||
4309515d | 1659 | -- Conversion is safe |
7d86aa98 | 1660 | |
1661 | Rewrite (Parent (Ck_Node), | |
1662 | Make_Integer_Literal (Loc, UI_To_Int (Int_Val))); | |
1663 | Analyze_And_Resolve (Parent (Ck_Node), Target_Typ); | |
1664 | return; | |
1665 | end if; | |
1666 | end; | |
1667 | end if; | |
1668 | ||
5329ca64 | 1669 | -- Check against lower bound |
1670 | ||
2af58f67 | 1671 | if Truncate and then Ifirst > 0 then |
1672 | Lo := Pred (Expr_Type, UR_From_Uint (Ifirst)); | |
1673 | Lo_OK := False; | |
1674 | ||
1675 | elsif Truncate then | |
1676 | Lo := Succ (Expr_Type, UR_From_Uint (Ifirst - 1)); | |
1677 | Lo_OK := True; | |
1678 | ||
1679 | elsif abs (Ifirst) < Max_Bound then | |
5329ca64 | 1680 | Lo := UR_From_Uint (Ifirst) - Ureal_Half; |
1681 | Lo_OK := (Ifirst > 0); | |
2af58f67 | 1682 | |
5329ca64 | 1683 | else |
1684 | Lo := Machine (Expr_Type, UR_From_Uint (Ifirst), Round_Even, Ck_Node); | |
1685 | Lo_OK := (Lo >= UR_From_Uint (Ifirst)); | |
1686 | end if; | |
1687 | ||
1688 | if Lo_OK then | |
1689 | ||
1690 | -- Lo_Chk := (X >= Lo) | |
1691 | ||
1692 | Lo_Chk := Make_Op_Ge (Loc, | |
1693 | Left_Opnd => Duplicate_Subexpr_No_Checks (Ck_Node), | |
1694 | Right_Opnd => Make_Real_Literal (Loc, Lo)); | |
1695 | ||
1696 | else | |
1697 | -- Lo_Chk := (X > Lo) | |
1698 | ||
1699 | Lo_Chk := Make_Op_Gt (Loc, | |
1700 | Left_Opnd => Duplicate_Subexpr_No_Checks (Ck_Node), | |
1701 | Right_Opnd => Make_Real_Literal (Loc, Lo)); | |
1702 | end if; | |
1703 | ||
1704 | -- Check against higher bound | |
1705 | ||
2af58f67 | 1706 | if Truncate and then Ilast < 0 then |
1707 | Hi := Succ (Expr_Type, UR_From_Uint (Ilast)); | |
1708 | Lo_OK := False; | |
1709 | ||
1710 | elsif Truncate then | |
1711 | Hi := Pred (Expr_Type, UR_From_Uint (Ilast + 1)); | |
1712 | Hi_OK := True; | |
1713 | ||
1714 | elsif abs (Ilast) < Max_Bound then | |
5329ca64 | 1715 | Hi := UR_From_Uint (Ilast) + Ureal_Half; |
1716 | Hi_OK := (Ilast < 0); | |
1717 | else | |
1718 | Hi := Machine (Expr_Type, UR_From_Uint (Ilast), Round_Even, Ck_Node); | |
1719 | Hi_OK := (Hi <= UR_From_Uint (Ilast)); | |
1720 | end if; | |
1721 | ||
1722 | if Hi_OK then | |
1723 | ||
1724 | -- Hi_Chk := (X <= Hi) | |
1725 | ||
1726 | Hi_Chk := Make_Op_Le (Loc, | |
1727 | Left_Opnd => Duplicate_Subexpr_No_Checks (Ck_Node), | |
1728 | Right_Opnd => Make_Real_Literal (Loc, Hi)); | |
1729 | ||
1730 | else | |
1731 | -- Hi_Chk := (X < Hi) | |
1732 | ||
1733 | Hi_Chk := Make_Op_Lt (Loc, | |
1734 | Left_Opnd => Duplicate_Subexpr_No_Checks (Ck_Node), | |
1735 | Right_Opnd => Make_Real_Literal (Loc, Hi)); | |
1736 | end if; | |
1737 | ||
feff2f05 | 1738 | -- If the bounds of the target type are the same as those of the base |
1739 | -- type, the check is an overflow check as a range check is not | |
1740 | -- performed in these cases. | |
5329ca64 | 1741 | |
1742 | if Expr_Value (Type_Low_Bound (Target_Base)) = Ifirst | |
1743 | and then Expr_Value (Type_High_Bound (Target_Base)) = Ilast | |
1744 | then | |
1745 | Reason := CE_Overflow_Check_Failed; | |
1746 | else | |
1747 | Reason := CE_Range_Check_Failed; | |
1748 | end if; | |
1749 | ||
1750 | -- Raise CE if either conditions does not hold | |
1751 | ||
1752 | Insert_Action (Ck_Node, | |
1753 | Make_Raise_Constraint_Error (Loc, | |
05fcfafb | 1754 | Condition => Make_Op_Not (Loc, Make_And_Then (Loc, Lo_Chk, Hi_Chk)), |
5329ca64 | 1755 | Reason => Reason)); |
1756 | end Apply_Float_Conversion_Check; | |
1757 | ||
ee6ba406 | 1758 | ------------------------ |
1759 | -- Apply_Length_Check -- | |
1760 | ------------------------ | |
1761 | ||
1762 | procedure Apply_Length_Check | |
1763 | (Ck_Node : Node_Id; | |
1764 | Target_Typ : Entity_Id; | |
1765 | Source_Typ : Entity_Id := Empty) | |
1766 | is | |
1767 | begin | |
1768 | Apply_Selected_Length_Checks | |
1769 | (Ck_Node, Target_Typ, Source_Typ, Do_Static => False); | |
1770 | end Apply_Length_Check; | |
1771 | ||
1772 | ----------------------- | |
1773 | -- Apply_Range_Check -- | |
1774 | ----------------------- | |
1775 | ||
1776 | procedure Apply_Range_Check | |
1777 | (Ck_Node : Node_Id; | |
1778 | Target_Typ : Entity_Id; | |
1779 | Source_Typ : Entity_Id := Empty) | |
1780 | is | |
1781 | begin | |
1782 | Apply_Selected_Range_Checks | |
1783 | (Ck_Node, Target_Typ, Source_Typ, Do_Static => False); | |
1784 | end Apply_Range_Check; | |
1785 | ||
1786 | ------------------------------ | |
1787 | -- Apply_Scalar_Range_Check -- | |
1788 | ------------------------------ | |
1789 | ||
feff2f05 | 1790 | -- Note that Apply_Scalar_Range_Check never turns the Do_Range_Check flag |
1791 | -- off if it is already set on. | |
ee6ba406 | 1792 | |
1793 | procedure Apply_Scalar_Range_Check | |
1794 | (Expr : Node_Id; | |
1795 | Target_Typ : Entity_Id; | |
1796 | Source_Typ : Entity_Id := Empty; | |
1797 | Fixed_Int : Boolean := False) | |
1798 | is | |
1799 | Parnt : constant Node_Id := Parent (Expr); | |
1800 | S_Typ : Entity_Id; | |
1801 | Arr : Node_Id := Empty; -- initialize to prevent warning | |
1802 | Arr_Typ : Entity_Id := Empty; -- initialize to prevent warning | |
1803 | OK : Boolean; | |
1804 | ||
1805 | Is_Subscr_Ref : Boolean; | |
1806 | -- Set true if Expr is a subscript | |
1807 | ||
1808 | Is_Unconstrained_Subscr_Ref : Boolean; | |
1809 | -- Set true if Expr is a subscript of an unconstrained array. In this | |
1810 | -- case we do not attempt to do an analysis of the value against the | |
1811 | -- range of the subscript, since we don't know the actual subtype. | |
1812 | ||
1813 | Int_Real : Boolean; | |
feff2f05 | 1814 | -- Set to True if Expr should be regarded as a real value even though |
1815 | -- the type of Expr might be discrete. | |
ee6ba406 | 1816 | |
1817 | procedure Bad_Value; | |
1818 | -- Procedure called if value is determined to be out of range | |
1819 | ||
9dfe12ae | 1820 | --------------- |
1821 | -- Bad_Value -- | |
1822 | --------------- | |
1823 | ||
ee6ba406 | 1824 | procedure Bad_Value is |
1825 | begin | |
1826 | Apply_Compile_Time_Constraint_Error | |
f15731c4 | 1827 | (Expr, "value not in range of}?", CE_Range_Check_Failed, |
ee6ba406 | 1828 | Ent => Target_Typ, |
1829 | Typ => Target_Typ); | |
1830 | end Bad_Value; | |
1831 | ||
9dfe12ae | 1832 | -- Start of processing for Apply_Scalar_Range_Check |
1833 | ||
ee6ba406 | 1834 | begin |
2af58f67 | 1835 | -- Return if check obviously not needed |
ee6ba406 | 1836 | |
2af58f67 | 1837 | if |
1838 | -- Not needed inside generic | |
ee6ba406 | 1839 | |
2af58f67 | 1840 | Inside_A_Generic |
1841 | ||
1842 | -- Not needed if previous error | |
1843 | ||
1844 | or else Target_Typ = Any_Type | |
1845 | or else Nkind (Expr) = N_Error | |
1846 | ||
1847 | -- Not needed for non-scalar type | |
1848 | ||
1849 | or else not Is_Scalar_Type (Target_Typ) | |
1850 | ||
1851 | -- Not needed if we know node raises CE already | |
1852 | ||
1853 | or else Raises_Constraint_Error (Expr) | |
ee6ba406 | 1854 | then |
1855 | return; | |
1856 | end if; | |
1857 | ||
1858 | -- Now, see if checks are suppressed | |
1859 | ||
1860 | Is_Subscr_Ref := | |
1861 | Is_List_Member (Expr) and then Nkind (Parnt) = N_Indexed_Component; | |
1862 | ||
1863 | if Is_Subscr_Ref then | |
1864 | Arr := Prefix (Parnt); | |
1865 | Arr_Typ := Get_Actual_Subtype_If_Available (Arr); | |
1866 | end if; | |
1867 | ||
1868 | if not Do_Range_Check (Expr) then | |
1869 | ||
1870 | -- Subscript reference. Check for Index_Checks suppressed | |
1871 | ||
1872 | if Is_Subscr_Ref then | |
1873 | ||
1874 | -- Check array type and its base type | |
1875 | ||
1876 | if Index_Checks_Suppressed (Arr_Typ) | |
9dfe12ae | 1877 | or else Index_Checks_Suppressed (Base_Type (Arr_Typ)) |
ee6ba406 | 1878 | then |
1879 | return; | |
1880 | ||
1881 | -- Check array itself if it is an entity name | |
1882 | ||
1883 | elsif Is_Entity_Name (Arr) | |
9dfe12ae | 1884 | and then Index_Checks_Suppressed (Entity (Arr)) |
ee6ba406 | 1885 | then |
1886 | return; | |
1887 | ||
1888 | -- Check expression itself if it is an entity name | |
1889 | ||
1890 | elsif Is_Entity_Name (Expr) | |
9dfe12ae | 1891 | and then Index_Checks_Suppressed (Entity (Expr)) |
ee6ba406 | 1892 | then |
1893 | return; | |
1894 | end if; | |
1895 | ||
1896 | -- All other cases, check for Range_Checks suppressed | |
1897 | ||
1898 | else | |
1899 | -- Check target type and its base type | |
1900 | ||
1901 | if Range_Checks_Suppressed (Target_Typ) | |
9dfe12ae | 1902 | or else Range_Checks_Suppressed (Base_Type (Target_Typ)) |
ee6ba406 | 1903 | then |
1904 | return; | |
1905 | ||
1906 | -- Check expression itself if it is an entity name | |
1907 | ||
1908 | elsif Is_Entity_Name (Expr) | |
9dfe12ae | 1909 | and then Range_Checks_Suppressed (Entity (Expr)) |
ee6ba406 | 1910 | then |
1911 | return; | |
1912 | ||
feff2f05 | 1913 | -- If Expr is part of an assignment statement, then check left |
1914 | -- side of assignment if it is an entity name. | |
ee6ba406 | 1915 | |
1916 | elsif Nkind (Parnt) = N_Assignment_Statement | |
1917 | and then Is_Entity_Name (Name (Parnt)) | |
9dfe12ae | 1918 | and then Range_Checks_Suppressed (Entity (Name (Parnt))) |
ee6ba406 | 1919 | then |
1920 | return; | |
1921 | end if; | |
1922 | end if; | |
1923 | end if; | |
1924 | ||
9dfe12ae | 1925 | -- Do not set range checks if they are killed |
1926 | ||
1927 | if Nkind (Expr) = N_Unchecked_Type_Conversion | |
1928 | and then Kill_Range_Check (Expr) | |
1929 | then | |
1930 | return; | |
1931 | end if; | |
1932 | ||
1933 | -- Do not set range checks for any values from System.Scalar_Values | |
1934 | -- since the whole idea of such values is to avoid checking them! | |
1935 | ||
1936 | if Is_Entity_Name (Expr) | |
1937 | and then Is_RTU (Scope (Entity (Expr)), System_Scalar_Values) | |
1938 | then | |
1939 | return; | |
1940 | end if; | |
1941 | ||
ee6ba406 | 1942 | -- Now see if we need a check |
1943 | ||
1944 | if No (Source_Typ) then | |
1945 | S_Typ := Etype (Expr); | |
1946 | else | |
1947 | S_Typ := Source_Typ; | |
1948 | end if; | |
1949 | ||
1950 | if not Is_Scalar_Type (S_Typ) or else S_Typ = Any_Type then | |
1951 | return; | |
1952 | end if; | |
1953 | ||
1954 | Is_Unconstrained_Subscr_Ref := | |
1955 | Is_Subscr_Ref and then not Is_Constrained (Arr_Typ); | |
1956 | ||
feff2f05 | 1957 | -- Always do a range check if the source type includes infinities and |
1958 | -- the target type does not include infinities. We do not do this if | |
1959 | -- range checks are killed. | |
ee6ba406 | 1960 | |
1961 | if Is_Floating_Point_Type (S_Typ) | |
1962 | and then Has_Infinities (S_Typ) | |
1963 | and then not Has_Infinities (Target_Typ) | |
1964 | then | |
1965 | Enable_Range_Check (Expr); | |
1966 | end if; | |
1967 | ||
feff2f05 | 1968 | -- Return if we know expression is definitely in the range of the target |
1969 | -- type as determined by Determine_Range. Right now we only do this for | |
1970 | -- discrete types, and not fixed-point or floating-point types. | |
ee6ba406 | 1971 | |
f2a06be9 | 1972 | -- The additional less-precise tests below catch these cases |
ee6ba406 | 1973 | |
feff2f05 | 1974 | -- Note: skip this if we are given a source_typ, since the point of |
1975 | -- supplying a Source_Typ is to stop us looking at the expression. | |
1976 | -- We could sharpen this test to be out parameters only ??? | |
ee6ba406 | 1977 | |
1978 | if Is_Discrete_Type (Target_Typ) | |
1979 | and then Is_Discrete_Type (Etype (Expr)) | |
1980 | and then not Is_Unconstrained_Subscr_Ref | |
1981 | and then No (Source_Typ) | |
1982 | then | |
1983 | declare | |
1984 | Tlo : constant Node_Id := Type_Low_Bound (Target_Typ); | |
1985 | Thi : constant Node_Id := Type_High_Bound (Target_Typ); | |
1986 | Lo : Uint; | |
1987 | Hi : Uint; | |
1988 | ||
1989 | begin | |
1990 | if Compile_Time_Known_Value (Tlo) | |
1991 | and then Compile_Time_Known_Value (Thi) | |
1992 | then | |
9dfe12ae | 1993 | declare |
1994 | Lov : constant Uint := Expr_Value (Tlo); | |
1995 | Hiv : constant Uint := Expr_Value (Thi); | |
ee6ba406 | 1996 | |
9dfe12ae | 1997 | begin |
1998 | -- If range is null, we for sure have a constraint error | |
1999 | -- (we don't even need to look at the value involved, | |
2000 | -- since all possible values will raise CE). | |
2001 | ||
2002 | if Lov > Hiv then | |
2003 | Bad_Value; | |
2004 | return; | |
2005 | end if; | |
2006 | ||
2007 | -- Otherwise determine range of value | |
2008 | ||
9c486805 | 2009 | Determine_Range (Expr, OK, Lo, Hi, Assume_Valid => True); |
9dfe12ae | 2010 | |
2011 | if OK then | |
2012 | ||
2013 | -- If definitely in range, all OK | |
ee6ba406 | 2014 | |
ee6ba406 | 2015 | if Lo >= Lov and then Hi <= Hiv then |
2016 | return; | |
2017 | ||
9dfe12ae | 2018 | -- If definitely not in range, warn |
2019 | ||
ee6ba406 | 2020 | elsif Lov > Hi or else Hiv < Lo then |
2021 | Bad_Value; | |
2022 | return; | |
9dfe12ae | 2023 | |
2024 | -- Otherwise we don't know | |
2025 | ||
2026 | else | |
2027 | null; | |
ee6ba406 | 2028 | end if; |
9dfe12ae | 2029 | end if; |
2030 | end; | |
ee6ba406 | 2031 | end if; |
2032 | end; | |
2033 | end if; | |
2034 | ||
2035 | Int_Real := | |
2036 | Is_Floating_Point_Type (S_Typ) | |
2037 | or else (Is_Fixed_Point_Type (S_Typ) and then not Fixed_Int); | |
2038 | ||
2039 | -- Check if we can determine at compile time whether Expr is in the | |
9dfe12ae | 2040 | -- range of the target type. Note that if S_Typ is within the bounds |
2041 | -- of Target_Typ then this must be the case. This check is meaningful | |
2042 | -- only if this is not a conversion between integer and real types. | |
ee6ba406 | 2043 | |
2044 | if not Is_Unconstrained_Subscr_Ref | |
2045 | and then | |
2046 | Is_Discrete_Type (S_Typ) = Is_Discrete_Type (Target_Typ) | |
2047 | and then | |
7a1dabb3 | 2048 | (In_Subrange_Of (S_Typ, Target_Typ, Fixed_Int) |
ee6ba406 | 2049 | or else |
9c486805 | 2050 | Is_In_Range (Expr, Target_Typ, |
2051 | Assume_Valid => True, | |
2052 | Fixed_Int => Fixed_Int, | |
2053 | Int_Real => Int_Real)) | |
ee6ba406 | 2054 | then |
2055 | return; | |
2056 | ||
9c486805 | 2057 | elsif Is_Out_Of_Range (Expr, Target_Typ, |
2058 | Assume_Valid => True, | |
2059 | Fixed_Int => Fixed_Int, | |
2060 | Int_Real => Int_Real) | |
2061 | then | |
ee6ba406 | 2062 | Bad_Value; |
2063 | return; | |
2064 | ||
feff2f05 | 2065 | -- In the floating-point case, we only do range checks if the type is |
2066 | -- constrained. We definitely do NOT want range checks for unconstrained | |
2067 | -- types, since we want to have infinities | |
ee6ba406 | 2068 | |
9dfe12ae | 2069 | elsif Is_Floating_Point_Type (S_Typ) then |
2070 | if Is_Constrained (S_Typ) then | |
2071 | Enable_Range_Check (Expr); | |
2072 | end if; | |
ee6ba406 | 2073 | |
9dfe12ae | 2074 | -- For all other cases we enable a range check unconditionally |
ee6ba406 | 2075 | |
2076 | else | |
2077 | Enable_Range_Check (Expr); | |
2078 | return; | |
2079 | end if; | |
ee6ba406 | 2080 | end Apply_Scalar_Range_Check; |
2081 | ||
2082 | ---------------------------------- | |
2083 | -- Apply_Selected_Length_Checks -- | |
2084 | ---------------------------------- | |
2085 | ||
2086 | procedure Apply_Selected_Length_Checks | |
2087 | (Ck_Node : Node_Id; | |
2088 | Target_Typ : Entity_Id; | |
2089 | Source_Typ : Entity_Id; | |
2090 | Do_Static : Boolean) | |
2091 | is | |
2092 | Cond : Node_Id; | |
2093 | R_Result : Check_Result; | |
2094 | R_Cno : Node_Id; | |
2095 | ||
2096 | Loc : constant Source_Ptr := Sloc (Ck_Node); | |
2097 | Checks_On : constant Boolean := | |
2098 | (not Index_Checks_Suppressed (Target_Typ)) | |
2099 | or else | |
2100 | (not Length_Checks_Suppressed (Target_Typ)); | |
2101 | ||
2102 | begin | |
f15731c4 | 2103 | if not Expander_Active then |
ee6ba406 | 2104 | return; |
2105 | end if; | |
2106 | ||
2107 | R_Result := | |
2108 | Selected_Length_Checks (Ck_Node, Target_Typ, Source_Typ, Empty); | |
2109 | ||
2110 | for J in 1 .. 2 loop | |
ee6ba406 | 2111 | R_Cno := R_Result (J); |
2112 | exit when No (R_Cno); | |
2113 | ||
2114 | -- A length check may mention an Itype which is attached to a | |
2115 | -- subsequent node. At the top level in a package this can cause | |
2116 | -- an order-of-elaboration problem, so we make sure that the itype | |
2117 | -- is referenced now. | |
2118 | ||
2119 | if Ekind (Current_Scope) = E_Package | |
2120 | and then Is_Compilation_Unit (Current_Scope) | |
2121 | then | |
2122 | Ensure_Defined (Target_Typ, Ck_Node); | |
2123 | ||
2124 | if Present (Source_Typ) then | |
2125 | Ensure_Defined (Source_Typ, Ck_Node); | |
2126 | ||
2127 | elsif Is_Itype (Etype (Ck_Node)) then | |
2128 | Ensure_Defined (Etype (Ck_Node), Ck_Node); | |
2129 | end if; | |
2130 | end if; | |
2131 | ||
feff2f05 | 2132 | -- If the item is a conditional raise of constraint error, then have |
2133 | -- a look at what check is being performed and ??? | |
ee6ba406 | 2134 | |
2135 | if Nkind (R_Cno) = N_Raise_Constraint_Error | |
2136 | and then Present (Condition (R_Cno)) | |
2137 | then | |
2138 | Cond := Condition (R_Cno); | |
2139 | ||
0577b0b1 | 2140 | -- Case where node does not now have a dynamic check |
ee6ba406 | 2141 | |
0577b0b1 | 2142 | if not Has_Dynamic_Length_Check (Ck_Node) then |
2143 | ||
2144 | -- If checks are on, just insert the check | |
2145 | ||
2146 | if Checks_On then | |
2147 | Insert_Action (Ck_Node, R_Cno); | |
2148 | ||
2149 | if not Do_Static then | |
2150 | Set_Has_Dynamic_Length_Check (Ck_Node); | |
2151 | end if; | |
2152 | ||
2153 | -- If checks are off, then analyze the length check after | |
2154 | -- temporarily attaching it to the tree in case the relevant | |
2155 | -- condition can be evaluted at compile time. We still want a | |
2156 | -- compile time warning in this case. | |
2157 | ||
2158 | else | |
2159 | Set_Parent (R_Cno, Ck_Node); | |
2160 | Analyze (R_Cno); | |
ee6ba406 | 2161 | end if; |
ee6ba406 | 2162 | end if; |
2163 | ||
2164 | -- Output a warning if the condition is known to be True | |
2165 | ||
2166 | if Is_Entity_Name (Cond) | |
2167 | and then Entity (Cond) = Standard_True | |
2168 | then | |
2169 | Apply_Compile_Time_Constraint_Error | |
2170 | (Ck_Node, "wrong length for array of}?", | |
f15731c4 | 2171 | CE_Length_Check_Failed, |
ee6ba406 | 2172 | Ent => Target_Typ, |
2173 | Typ => Target_Typ); | |
2174 | ||
2175 | -- If we were only doing a static check, or if checks are not | |
2176 | -- on, then we want to delete the check, since it is not needed. | |
2177 | -- We do this by replacing the if statement by a null statement | |
2178 | ||
2179 | elsif Do_Static or else not Checks_On then | |
00c403ee | 2180 | Remove_Warning_Messages (R_Cno); |
ee6ba406 | 2181 | Rewrite (R_Cno, Make_Null_Statement (Loc)); |
2182 | end if; | |
2183 | ||
2184 | else | |
2185 | Install_Static_Check (R_Cno, Loc); | |
2186 | end if; | |
ee6ba406 | 2187 | end loop; |
ee6ba406 | 2188 | end Apply_Selected_Length_Checks; |
2189 | ||
2190 | --------------------------------- | |
2191 | -- Apply_Selected_Range_Checks -- | |
2192 | --------------------------------- | |
2193 | ||
2194 | procedure Apply_Selected_Range_Checks | |
2195 | (Ck_Node : Node_Id; | |
2196 | Target_Typ : Entity_Id; | |
2197 | Source_Typ : Entity_Id; | |
2198 | Do_Static : Boolean) | |
2199 | is | |
2200 | Cond : Node_Id; | |
2201 | R_Result : Check_Result; | |
2202 | R_Cno : Node_Id; | |
2203 | ||
2204 | Loc : constant Source_Ptr := Sloc (Ck_Node); | |
2205 | Checks_On : constant Boolean := | |
2206 | (not Index_Checks_Suppressed (Target_Typ)) | |
2207 | or else | |
2208 | (not Range_Checks_Suppressed (Target_Typ)); | |
2209 | ||
2210 | begin | |
2211 | if not Expander_Active or else not Checks_On then | |
2212 | return; | |
2213 | end if; | |
2214 | ||
2215 | R_Result := | |
2216 | Selected_Range_Checks (Ck_Node, Target_Typ, Source_Typ, Empty); | |
2217 | ||
2218 | for J in 1 .. 2 loop | |
2219 | ||
2220 | R_Cno := R_Result (J); | |
2221 | exit when No (R_Cno); | |
2222 | ||
feff2f05 | 2223 | -- If the item is a conditional raise of constraint error, then have |
2224 | -- a look at what check is being performed and ??? | |
ee6ba406 | 2225 | |
2226 | if Nkind (R_Cno) = N_Raise_Constraint_Error | |
2227 | and then Present (Condition (R_Cno)) | |
2228 | then | |
2229 | Cond := Condition (R_Cno); | |
2230 | ||
2231 | if not Has_Dynamic_Range_Check (Ck_Node) then | |
2232 | Insert_Action (Ck_Node, R_Cno); | |
2233 | ||
2234 | if not Do_Static then | |
2235 | Set_Has_Dynamic_Range_Check (Ck_Node); | |
2236 | end if; | |
2237 | end if; | |
2238 | ||
2239 | -- Output a warning if the condition is known to be True | |
2240 | ||
2241 | if Is_Entity_Name (Cond) | |
2242 | and then Entity (Cond) = Standard_True | |
2243 | then | |
feff2f05 | 2244 | -- Since an N_Range is technically not an expression, we have |
2245 | -- to set one of the bounds to C_E and then just flag the | |
2246 | -- N_Range. The warning message will point to the lower bound | |
2247 | -- and complain about a range, which seems OK. | |
ee6ba406 | 2248 | |
2249 | if Nkind (Ck_Node) = N_Range then | |
2250 | Apply_Compile_Time_Constraint_Error | |
2251 | (Low_Bound (Ck_Node), "static range out of bounds of}?", | |
f15731c4 | 2252 | CE_Range_Check_Failed, |
ee6ba406 | 2253 | Ent => Target_Typ, |
2254 | Typ => Target_Typ); | |
2255 | ||
2256 | Set_Raises_Constraint_Error (Ck_Node); | |
2257 | ||
2258 | else | |
2259 | Apply_Compile_Time_Constraint_Error | |
2260 | (Ck_Node, "static value out of range of}?", | |
f15731c4 | 2261 | CE_Range_Check_Failed, |
ee6ba406 | 2262 | Ent => Target_Typ, |
2263 | Typ => Target_Typ); | |
2264 | end if; | |
2265 | ||
2266 | -- If we were only doing a static check, or if checks are not | |
2267 | -- on, then we want to delete the check, since it is not needed. | |
2268 | -- We do this by replacing the if statement by a null statement | |
2269 | ||
2270 | elsif Do_Static or else not Checks_On then | |
00c403ee | 2271 | Remove_Warning_Messages (R_Cno); |
ee6ba406 | 2272 | Rewrite (R_Cno, Make_Null_Statement (Loc)); |
2273 | end if; | |
2274 | ||
2275 | else | |
2276 | Install_Static_Check (R_Cno, Loc); | |
2277 | end if; | |
ee6ba406 | 2278 | end loop; |
ee6ba406 | 2279 | end Apply_Selected_Range_Checks; |
2280 | ||
2281 | ------------------------------- | |
2282 | -- Apply_Static_Length_Check -- | |
2283 | ------------------------------- | |
2284 | ||
2285 | procedure Apply_Static_Length_Check | |
2286 | (Expr : Node_Id; | |
2287 | Target_Typ : Entity_Id; | |
2288 | Source_Typ : Entity_Id := Empty) | |
2289 | is | |
2290 | begin | |
2291 | Apply_Selected_Length_Checks | |
2292 | (Expr, Target_Typ, Source_Typ, Do_Static => True); | |
2293 | end Apply_Static_Length_Check; | |
2294 | ||
2295 | ------------------------------------- | |
2296 | -- Apply_Subscript_Validity_Checks -- | |
2297 | ------------------------------------- | |
2298 | ||
2299 | procedure Apply_Subscript_Validity_Checks (Expr : Node_Id) is | |
2300 | Sub : Node_Id; | |
2301 | ||
2302 | begin | |
2303 | pragma Assert (Nkind (Expr) = N_Indexed_Component); | |
2304 | ||
2305 | -- Loop through subscripts | |
2306 | ||
2307 | Sub := First (Expressions (Expr)); | |
2308 | while Present (Sub) loop | |
2309 | ||
feff2f05 | 2310 | -- Check one subscript. Note that we do not worry about enumeration |
2311 | -- type with holes, since we will convert the value to a Pos value | |
2312 | -- for the subscript, and that convert will do the necessary validity | |
2313 | -- check. | |
ee6ba406 | 2314 | |
2315 | Ensure_Valid (Sub, Holes_OK => True); | |
2316 | ||
2317 | -- Move to next subscript | |
2318 | ||
2319 | Sub := Next (Sub); | |
2320 | end loop; | |
2321 | end Apply_Subscript_Validity_Checks; | |
2322 | ||
2323 | ---------------------------------- | |
2324 | -- Apply_Type_Conversion_Checks -- | |
2325 | ---------------------------------- | |
2326 | ||
2327 | procedure Apply_Type_Conversion_Checks (N : Node_Id) is | |
2328 | Target_Type : constant Entity_Id := Etype (N); | |
2329 | Target_Base : constant Entity_Id := Base_Type (Target_Type); | |
9dfe12ae | 2330 | Expr : constant Node_Id := Expression (N); |
2331 | Expr_Type : constant Entity_Id := Etype (Expr); | |
ee6ba406 | 2332 | |
2333 | begin | |
2334 | if Inside_A_Generic then | |
2335 | return; | |
2336 | ||
f15731c4 | 2337 | -- Skip these checks if serious errors detected, there are some nasty |
ee6ba406 | 2338 | -- situations of incomplete trees that blow things up. |
2339 | ||
f15731c4 | 2340 | elsif Serious_Errors_Detected > 0 then |
ee6ba406 | 2341 | return; |
2342 | ||
feff2f05 | 2343 | -- Scalar type conversions of the form Target_Type (Expr) require a |
2344 | -- range check if we cannot be sure that Expr is in the base type of | |
2345 | -- Target_Typ and also that Expr is in the range of Target_Typ. These | |
2346 | -- are not quite the same condition from an implementation point of | |
2347 | -- view, but clearly the second includes the first. | |
ee6ba406 | 2348 | |
2349 | elsif Is_Scalar_Type (Target_Type) then | |
2350 | declare | |
2351 | Conv_OK : constant Boolean := Conversion_OK (N); | |
feff2f05 | 2352 | -- If the Conversion_OK flag on the type conversion is set and no |
2353 | -- floating point type is involved in the type conversion then | |
2354 | -- fixed point values must be read as integral values. | |
ee6ba406 | 2355 | |
5329ca64 | 2356 | Float_To_Int : constant Boolean := |
2357 | Is_Floating_Point_Type (Expr_Type) | |
2358 | and then Is_Integer_Type (Target_Type); | |
2359 | ||
ee6ba406 | 2360 | begin |
ee6ba406 | 2361 | if not Overflow_Checks_Suppressed (Target_Base) |
e254d721 | 2362 | and then not |
7a1dabb3 | 2363 | In_Subrange_Of (Expr_Type, Target_Base, Fixed_Int => Conv_OK) |
5329ca64 | 2364 | and then not Float_To_Int |
ee6ba406 | 2365 | then |
00c403ee | 2366 | Activate_Overflow_Check (N); |
ee6ba406 | 2367 | end if; |
2368 | ||
2369 | if not Range_Checks_Suppressed (Target_Type) | |
2370 | and then not Range_Checks_Suppressed (Expr_Type) | |
2371 | then | |
5329ca64 | 2372 | if Float_To_Int then |
2373 | Apply_Float_Conversion_Check (Expr, Target_Type); | |
2374 | else | |
2375 | Apply_Scalar_Range_Check | |
2376 | (Expr, Target_Type, Fixed_Int => Conv_OK); | |
2377 | end if; | |
ee6ba406 | 2378 | end if; |
2379 | end; | |
2380 | ||
2381 | elsif Comes_From_Source (N) | |
f40f9731 | 2382 | and then not Discriminant_Checks_Suppressed (Target_Type) |
ee6ba406 | 2383 | and then Is_Record_Type (Target_Type) |
2384 | and then Is_Derived_Type (Target_Type) | |
2385 | and then not Is_Tagged_Type (Target_Type) | |
2386 | and then not Is_Constrained (Target_Type) | |
9dfe12ae | 2387 | and then Present (Stored_Constraint (Target_Type)) |
ee6ba406 | 2388 | then |
9dfe12ae | 2389 | -- An unconstrained derived type may have inherited discriminant |
2390 | -- Build an actual discriminant constraint list using the stored | |
ee6ba406 | 2391 | -- constraint, to verify that the expression of the parent type |
2392 | -- satisfies the constraints imposed by the (unconstrained!) | |
2393 | -- derived type. This applies to value conversions, not to view | |
2394 | -- conversions of tagged types. | |
2395 | ||
2396 | declare | |
9dfe12ae | 2397 | Loc : constant Source_Ptr := Sloc (N); |
2398 | Cond : Node_Id; | |
2399 | Constraint : Elmt_Id; | |
2400 | Discr_Value : Node_Id; | |
2401 | Discr : Entity_Id; | |
2402 | ||
2403 | New_Constraints : constant Elist_Id := New_Elmt_List; | |
2404 | Old_Constraints : constant Elist_Id := | |
2405 | Discriminant_Constraint (Expr_Type); | |
ee6ba406 | 2406 | |
2407 | begin | |
9dfe12ae | 2408 | Constraint := First_Elmt (Stored_Constraint (Target_Type)); |
ee6ba406 | 2409 | while Present (Constraint) loop |
2410 | Discr_Value := Node (Constraint); | |
2411 | ||
2412 | if Is_Entity_Name (Discr_Value) | |
2413 | and then Ekind (Entity (Discr_Value)) = E_Discriminant | |
2414 | then | |
2415 | Discr := Corresponding_Discriminant (Entity (Discr_Value)); | |
2416 | ||
2417 | if Present (Discr) | |
2418 | and then Scope (Discr) = Base_Type (Expr_Type) | |
2419 | then | |
2420 | -- Parent is constrained by new discriminant. Obtain | |
feff2f05 | 2421 | -- Value of original discriminant in expression. If the |
2422 | -- new discriminant has been used to constrain more than | |
2423 | -- one of the stored discriminants, this will provide the | |
2424 | -- required consistency check. | |
ee6ba406 | 2425 | |
2426 | Append_Elmt ( | |
2427 | Make_Selected_Component (Loc, | |
2428 | Prefix => | |
9dfe12ae | 2429 | Duplicate_Subexpr_No_Checks |
2430 | (Expr, Name_Req => True), | |
ee6ba406 | 2431 | Selector_Name => |
2432 | Make_Identifier (Loc, Chars (Discr))), | |
2433 | New_Constraints); | |
2434 | ||
2435 | else | |
2436 | -- Discriminant of more remote ancestor ??? | |
2437 | ||
2438 | return; | |
2439 | end if; | |
2440 | ||
feff2f05 | 2441 | -- Derived type definition has an explicit value for this |
2442 | -- stored discriminant. | |
ee6ba406 | 2443 | |
2444 | else | |
2445 | Append_Elmt | |
9dfe12ae | 2446 | (Duplicate_Subexpr_No_Checks (Discr_Value), |
2447 | New_Constraints); | |
ee6ba406 | 2448 | end if; |
2449 | ||
2450 | Next_Elmt (Constraint); | |
2451 | end loop; | |
2452 | ||
2453 | -- Use the unconstrained expression type to retrieve the | |
2454 | -- discriminants of the parent, and apply momentarily the | |
2455 | -- discriminant constraint synthesized above. | |
2456 | ||
2457 | Set_Discriminant_Constraint (Expr_Type, New_Constraints); | |
2458 | Cond := Build_Discriminant_Checks (Expr, Expr_Type); | |
2459 | Set_Discriminant_Constraint (Expr_Type, Old_Constraints); | |
2460 | ||
2461 | Insert_Action (N, | |
f15731c4 | 2462 | Make_Raise_Constraint_Error (Loc, |
2463 | Condition => Cond, | |
2464 | Reason => CE_Discriminant_Check_Failed)); | |
ee6ba406 | 2465 | end; |
2466 | ||
feff2f05 | 2467 | -- For arrays, conversions are applied during expansion, to take into |
2468 | -- accounts changes of representation. The checks become range checks on | |
2469 | -- the base type or length checks on the subtype, depending on whether | |
2470 | -- the target type is unconstrained or constrained. | |
ee6ba406 | 2471 | |
2472 | else | |
2473 | null; | |
2474 | end if; | |
ee6ba406 | 2475 | end Apply_Type_Conversion_Checks; |
2476 | ||
2477 | ---------------------------------------------- | |
2478 | -- Apply_Universal_Integer_Attribute_Checks -- | |
2479 | ---------------------------------------------- | |
2480 | ||
2481 | procedure Apply_Universal_Integer_Attribute_Checks (N : Node_Id) is | |
2482 | Loc : constant Source_Ptr := Sloc (N); | |
2483 | Typ : constant Entity_Id := Etype (N); | |
2484 | ||
2485 | begin | |
2486 | if Inside_A_Generic then | |
2487 | return; | |
2488 | ||
2489 | -- Nothing to do if checks are suppressed | |
2490 | ||
2491 | elsif Range_Checks_Suppressed (Typ) | |
2492 | and then Overflow_Checks_Suppressed (Typ) | |
2493 | then | |
2494 | return; | |
2495 | ||
2496 | -- Nothing to do if the attribute does not come from source. The | |
2497 | -- internal attributes we generate of this type do not need checks, | |
2498 | -- and furthermore the attempt to check them causes some circular | |
2499 | -- elaboration orders when dealing with packed types. | |
2500 | ||
2501 | elsif not Comes_From_Source (N) then | |
2502 | return; | |
2503 | ||
9dfe12ae | 2504 | -- If the prefix is a selected component that depends on a discriminant |
2505 | -- the check may improperly expose a discriminant instead of using | |
2506 | -- the bounds of the object itself. Set the type of the attribute to | |
2507 | -- the base type of the context, so that a check will be imposed when | |
2508 | -- needed (e.g. if the node appears as an index). | |
2509 | ||
2510 | elsif Nkind (Prefix (N)) = N_Selected_Component | |
2511 | and then Ekind (Typ) = E_Signed_Integer_Subtype | |
2512 | and then Depends_On_Discriminant (Scalar_Range (Typ)) | |
2513 | then | |
2514 | Set_Etype (N, Base_Type (Typ)); | |
2515 | ||
feff2f05 | 2516 | -- Otherwise, replace the attribute node with a type conversion node |
2517 | -- whose expression is the attribute, retyped to universal integer, and | |
2518 | -- whose subtype mark is the target type. The call to analyze this | |
2519 | -- conversion will set range and overflow checks as required for proper | |
2520 | -- detection of an out of range value. | |
ee6ba406 | 2521 | |
2522 | else | |
2523 | Set_Etype (N, Universal_Integer); | |
2524 | Set_Analyzed (N, True); | |
2525 | ||
2526 | Rewrite (N, | |
2527 | Make_Type_Conversion (Loc, | |
2528 | Subtype_Mark => New_Occurrence_Of (Typ, Loc), | |
2529 | Expression => Relocate_Node (N))); | |
2530 | ||
2531 | Analyze_And_Resolve (N, Typ); | |
2532 | return; | |
2533 | end if; | |
ee6ba406 | 2534 | end Apply_Universal_Integer_Attribute_Checks; |
2535 | ||
2536 | ------------------------------- | |
2537 | -- Build_Discriminant_Checks -- | |
2538 | ------------------------------- | |
2539 | ||
2540 | function Build_Discriminant_Checks | |
2541 | (N : Node_Id; | |
314a23b6 | 2542 | T_Typ : Entity_Id) return Node_Id |
ee6ba406 | 2543 | is |
2544 | Loc : constant Source_Ptr := Sloc (N); | |
2545 | Cond : Node_Id; | |
2546 | Disc : Elmt_Id; | |
2547 | Disc_Ent : Entity_Id; | |
9dfe12ae | 2548 | Dref : Node_Id; |
ee6ba406 | 2549 | Dval : Node_Id; |
2550 | ||
84d0d4a5 | 2551 | function Aggregate_Discriminant_Val (Disc : Entity_Id) return Node_Id; |
2552 | ||
2553 | ---------------------------------- | |
2554 | -- Aggregate_Discriminant_Value -- | |
2555 | ---------------------------------- | |
2556 | ||
2557 | function Aggregate_Discriminant_Val (Disc : Entity_Id) return Node_Id is | |
2558 | Assoc : Node_Id; | |
2559 | ||
2560 | begin | |
feff2f05 | 2561 | -- The aggregate has been normalized with named associations. We use |
2562 | -- the Chars field to locate the discriminant to take into account | |
2563 | -- discriminants in derived types, which carry the same name as those | |
2564 | -- in the parent. | |
84d0d4a5 | 2565 | |
2566 | Assoc := First (Component_Associations (N)); | |
2567 | while Present (Assoc) loop | |
2568 | if Chars (First (Choices (Assoc))) = Chars (Disc) then | |
2569 | return Expression (Assoc); | |
2570 | else | |
2571 | Next (Assoc); | |
2572 | end if; | |
2573 | end loop; | |
2574 | ||
2575 | -- Discriminant must have been found in the loop above | |
2576 | ||
2577 | raise Program_Error; | |
2578 | end Aggregate_Discriminant_Val; | |
2579 | ||
2580 | -- Start of processing for Build_Discriminant_Checks | |
2581 | ||
ee6ba406 | 2582 | begin |
84d0d4a5 | 2583 | -- Loop through discriminants evolving the condition |
2584 | ||
ee6ba406 | 2585 | Cond := Empty; |
2586 | Disc := First_Elmt (Discriminant_Constraint (T_Typ)); | |
2587 | ||
9dfe12ae | 2588 | -- For a fully private type, use the discriminants of the parent type |
ee6ba406 | 2589 | |
2590 | if Is_Private_Type (T_Typ) | |
2591 | and then No (Full_View (T_Typ)) | |
2592 | then | |
2593 | Disc_Ent := First_Discriminant (Etype (Base_Type (T_Typ))); | |
2594 | else | |
2595 | Disc_Ent := First_Discriminant (T_Typ); | |
2596 | end if; | |
2597 | ||
2598 | while Present (Disc) loop | |
ee6ba406 | 2599 | Dval := Node (Disc); |
2600 | ||
2601 | if Nkind (Dval) = N_Identifier | |
2602 | and then Ekind (Entity (Dval)) = E_Discriminant | |
2603 | then | |
2604 | Dval := New_Occurrence_Of (Discriminal (Entity (Dval)), Loc); | |
2605 | else | |
9dfe12ae | 2606 | Dval := Duplicate_Subexpr_No_Checks (Dval); |
ee6ba406 | 2607 | end if; |
2608 | ||
00f91aef | 2609 | -- If we have an Unchecked_Union node, we can infer the discriminants |
2610 | -- of the node. | |
9dfe12ae | 2611 | |
00f91aef | 2612 | if Is_Unchecked_Union (Base_Type (T_Typ)) then |
2613 | Dref := New_Copy ( | |
2614 | Get_Discriminant_Value ( | |
2615 | First_Discriminant (T_Typ), | |
2616 | T_Typ, | |
2617 | Stored_Constraint (T_Typ))); | |
2618 | ||
84d0d4a5 | 2619 | elsif Nkind (N) = N_Aggregate then |
2620 | Dref := | |
2621 | Duplicate_Subexpr_No_Checks | |
2622 | (Aggregate_Discriminant_Val (Disc_Ent)); | |
2623 | ||
00f91aef | 2624 | else |
2625 | Dref := | |
2626 | Make_Selected_Component (Loc, | |
2627 | Prefix => | |
2628 | Duplicate_Subexpr_No_Checks (N, Name_Req => True), | |
2629 | Selector_Name => | |
2630 | Make_Identifier (Loc, Chars (Disc_Ent))); | |
2631 | ||
2632 | Set_Is_In_Discriminant_Check (Dref); | |
2633 | end if; | |
9dfe12ae | 2634 | |
ee6ba406 | 2635 | Evolve_Or_Else (Cond, |
2636 | Make_Op_Ne (Loc, | |
9dfe12ae | 2637 | Left_Opnd => Dref, |
ee6ba406 | 2638 | Right_Opnd => Dval)); |
2639 | ||
2640 | Next_Elmt (Disc); | |
2641 | Next_Discriminant (Disc_Ent); | |
2642 | end loop; | |
2643 | ||
2644 | return Cond; | |
2645 | end Build_Discriminant_Checks; | |
2646 | ||
13dbf220 | 2647 | ------------------ |
2648 | -- Check_Needed -- | |
2649 | ------------------ | |
2650 | ||
2651 | function Check_Needed (Nod : Node_Id; Check : Check_Type) return Boolean is | |
2652 | N : Node_Id; | |
2653 | P : Node_Id; | |
2654 | K : Node_Kind; | |
2655 | L : Node_Id; | |
2656 | R : Node_Id; | |
2657 | ||
2658 | begin | |
2659 | -- Always check if not simple entity | |
2660 | ||
2661 | if Nkind (Nod) not in N_Has_Entity | |
2662 | or else not Comes_From_Source (Nod) | |
2663 | then | |
2664 | return True; | |
2665 | end if; | |
2666 | ||
2667 | -- Look up tree for short circuit | |
2668 | ||
2669 | N := Nod; | |
2670 | loop | |
2671 | P := Parent (N); | |
2672 | K := Nkind (P); | |
2673 | ||
7b17e51b | 2674 | -- Done if out of subexpression (note that we allow generated stuff |
2675 | -- such as itype declarations in this context, to keep the loop going | |
2676 | -- since we may well have generated such stuff in complex situations. | |
2677 | -- Also done if no parent (probably an error condition, but no point | |
2678 | -- in behaving nasty if we find it!) | |
2679 | ||
2680 | if No (P) | |
2681 | or else (K not in N_Subexpr and then Comes_From_Source (P)) | |
2682 | then | |
13dbf220 | 2683 | return True; |
2684 | ||
7b17e51b | 2685 | -- Or/Or Else case, where test is part of the right operand, or is |
2686 | -- part of one of the actions associated with the right operand, and | |
2687 | -- the left operand is an equality test. | |
13dbf220 | 2688 | |
7b17e51b | 2689 | elsif K = N_Op_Or then |
13dbf220 | 2690 | exit when N = Right_Opnd (P) |
2691 | and then Nkind (Left_Opnd (P)) = N_Op_Eq; | |
2692 | ||
7b17e51b | 2693 | elsif K = N_Or_Else then |
2694 | exit when (N = Right_Opnd (P) | |
2695 | or else | |
2696 | (Is_List_Member (N) | |
2697 | and then List_Containing (N) = Actions (P))) | |
2698 | and then Nkind (Left_Opnd (P)) = N_Op_Eq; | |
13dbf220 | 2699 | |
7b17e51b | 2700 | -- Similar test for the And/And then case, where the left operand |
2701 | -- is an inequality test. | |
2702 | ||
2703 | elsif K = N_Op_And then | |
13dbf220 | 2704 | exit when N = Right_Opnd (P) |
38f5559f | 2705 | and then Nkind (Left_Opnd (P)) = N_Op_Ne; |
7b17e51b | 2706 | |
2707 | elsif K = N_And_Then then | |
2708 | exit when (N = Right_Opnd (P) | |
2709 | or else | |
2710 | (Is_List_Member (N) | |
2711 | and then List_Containing (N) = Actions (P))) | |
2712 | and then Nkind (Left_Opnd (P)) = N_Op_Ne; | |
13dbf220 | 2713 | end if; |
2714 | ||
2715 | N := P; | |
2716 | end loop; | |
2717 | ||
2718 | -- If we fall through the loop, then we have a conditional with an | |
2719 | -- appropriate test as its left operand. So test further. | |
2720 | ||
2721 | L := Left_Opnd (P); | |
13dbf220 | 2722 | R := Right_Opnd (L); |
2723 | L := Left_Opnd (L); | |
2724 | ||
2725 | -- Left operand of test must match original variable | |
2726 | ||
2727 | if Nkind (L) not in N_Has_Entity | |
2728 | or else Entity (L) /= Entity (Nod) | |
2729 | then | |
2730 | return True; | |
2731 | end if; | |
2732 | ||
2af58f67 | 2733 | -- Right operand of test must be key value (zero or null) |
13dbf220 | 2734 | |
2735 | case Check is | |
2736 | when Access_Check => | |
2af58f67 | 2737 | if not Known_Null (R) then |
13dbf220 | 2738 | return True; |
2739 | end if; | |
2740 | ||
2741 | when Division_Check => | |
2742 | if not Compile_Time_Known_Value (R) | |
2743 | or else Expr_Value (R) /= Uint_0 | |
2744 | then | |
2745 | return True; | |
2746 | end if; | |
2af58f67 | 2747 | |
2748 | when others => | |
2749 | raise Program_Error; | |
13dbf220 | 2750 | end case; |
2751 | ||
2752 | -- Here we have the optimizable case, warn if not short-circuited | |
2753 | ||
2754 | if K = N_Op_And or else K = N_Op_Or then | |
2755 | case Check is | |
2756 | when Access_Check => | |
2757 | Error_Msg_N | |
2758 | ("Constraint_Error may be raised (access check)?", | |
2759 | Parent (Nod)); | |
2760 | when Division_Check => | |
2761 | Error_Msg_N | |
2762 | ("Constraint_Error may be raised (zero divide)?", | |
2763 | Parent (Nod)); | |
2af58f67 | 2764 | |
2765 | when others => | |
2766 | raise Program_Error; | |
13dbf220 | 2767 | end case; |
2768 | ||
2769 | if K = N_Op_And then | |
2770 | Error_Msg_N ("use `AND THEN` instead of AND?", P); | |
2771 | else | |
2772 | Error_Msg_N ("use `OR ELSE` instead of OR?", P); | |
2773 | end if; | |
2774 | ||
2775 | -- If not short-circuited, we need the ckeck | |
2776 | ||
2777 | return True; | |
2778 | ||
2779 | -- If short-circuited, we can omit the check | |
2780 | ||
2781 | else | |
2782 | return False; | |
2783 | end if; | |
2784 | end Check_Needed; | |
2785 | ||
ee6ba406 | 2786 | ----------------------------------- |
2787 | -- Check_Valid_Lvalue_Subscripts -- | |
2788 | ----------------------------------- | |
2789 | ||
2790 | procedure Check_Valid_Lvalue_Subscripts (Expr : Node_Id) is | |
2791 | begin | |
2792 | -- Skip this if range checks are suppressed | |
2793 | ||
2794 | if Range_Checks_Suppressed (Etype (Expr)) then | |
2795 | return; | |
2796 | ||
feff2f05 | 2797 | -- Only do this check for expressions that come from source. We assume |
2798 | -- that expander generated assignments explicitly include any necessary | |
2799 | -- checks. Note that this is not just an optimization, it avoids | |
2800 | -- infinite recursions! | |
ee6ba406 | 2801 | |
2802 | elsif not Comes_From_Source (Expr) then | |
2803 | return; | |
2804 | ||
2805 | -- For a selected component, check the prefix | |
2806 | ||
2807 | elsif Nkind (Expr) = N_Selected_Component then | |
2808 | Check_Valid_Lvalue_Subscripts (Prefix (Expr)); | |
2809 | return; | |
2810 | ||
2811 | -- Case of indexed component | |
2812 | ||
2813 | elsif Nkind (Expr) = N_Indexed_Component then | |
2814 | Apply_Subscript_Validity_Checks (Expr); | |
2815 | ||
feff2f05 | 2816 | -- Prefix may itself be or contain an indexed component, and these |
2817 | -- subscripts need checking as well. | |
ee6ba406 | 2818 | |
2819 | Check_Valid_Lvalue_Subscripts (Prefix (Expr)); | |
2820 | end if; | |
2821 | end Check_Valid_Lvalue_Subscripts; | |
2822 | ||
fa7497e8 | 2823 | ---------------------------------- |
2824 | -- Null_Exclusion_Static_Checks -- | |
2825 | ---------------------------------- | |
2826 | ||
2827 | procedure Null_Exclusion_Static_Checks (N : Node_Id) is | |
0577b0b1 | 2828 | Error_Node : Node_Id; |
2829 | Expr : Node_Id; | |
2830 | Has_Null : constant Boolean := Has_Null_Exclusion (N); | |
2831 | K : constant Node_Kind := Nkind (N); | |
2832 | Typ : Entity_Id; | |
fa7497e8 | 2833 | |
13dbf220 | 2834 | begin |
0577b0b1 | 2835 | pragma Assert |
2836 | (K = N_Component_Declaration | |
2837 | or else K = N_Discriminant_Specification | |
2838 | or else K = N_Function_Specification | |
2839 | or else K = N_Object_Declaration | |
2840 | or else K = N_Parameter_Specification); | |
2841 | ||
2842 | if K = N_Function_Specification then | |
2843 | Typ := Etype (Defining_Entity (N)); | |
2844 | else | |
2845 | Typ := Etype (Defining_Identifier (N)); | |
2846 | end if; | |
fa7497e8 | 2847 | |
13dbf220 | 2848 | case K is |
13dbf220 | 2849 | when N_Component_Declaration => |
2850 | if Present (Access_Definition (Component_Definition (N))) then | |
0577b0b1 | 2851 | Error_Node := Component_Definition (N); |
13dbf220 | 2852 | else |
0577b0b1 | 2853 | Error_Node := Subtype_Indication (Component_Definition (N)); |
13dbf220 | 2854 | end if; |
5329ca64 | 2855 | |
0577b0b1 | 2856 | when N_Discriminant_Specification => |
2857 | Error_Node := Discriminant_Type (N); | |
2858 | ||
2859 | when N_Function_Specification => | |
2860 | Error_Node := Result_Definition (N); | |
2861 | ||
2862 | when N_Object_Declaration => | |
2863 | Error_Node := Object_Definition (N); | |
2864 | ||
2865 | when N_Parameter_Specification => | |
2866 | Error_Node := Parameter_Type (N); | |
2867 | ||
13dbf220 | 2868 | when others => |
2869 | raise Program_Error; | |
2870 | end case; | |
5329ca64 | 2871 | |
0577b0b1 | 2872 | if Has_Null then |
5329ca64 | 2873 | |
0577b0b1 | 2874 | -- Enforce legality rule 3.10 (13): A null exclusion can only be |
2875 | -- applied to an access [sub]type. | |
5329ca64 | 2876 | |
0577b0b1 | 2877 | if not Is_Access_Type (Typ) then |
2878 | Error_Msg_N | |
00c403ee | 2879 | ("`NOT NULL` allowed only for an access type", Error_Node); |
5329ca64 | 2880 | |
feff2f05 | 2881 | -- Enforce legality rule RM 3.10(14/1): A null exclusion can only |
0577b0b1 | 2882 | -- be applied to a [sub]type that does not exclude null already. |
2883 | ||
2884 | elsif Can_Never_Be_Null (Typ) | |
d16989f1 | 2885 | and then Comes_From_Source (Typ) |
0577b0b1 | 2886 | then |
00c403ee | 2887 | Error_Msg_NE |
2888 | ("`NOT NULL` not allowed (& already excludes null)", | |
2889 | Error_Node, Typ); | |
0577b0b1 | 2890 | end if; |
13dbf220 | 2891 | end if; |
5329ca64 | 2892 | |
cc60bd16 | 2893 | -- Check that null-excluding objects are always initialized, except for |
2894 | -- deferred constants, for which the expression will appear in the full | |
2895 | -- declaration. | |
13dbf220 | 2896 | |
2897 | if K = N_Object_Declaration | |
84d0d4a5 | 2898 | and then No (Expression (N)) |
cc60bd16 | 2899 | and then not Constant_Present (N) |
feff2f05 | 2900 | and then not No_Initialization (N) |
13dbf220 | 2901 | then |
feff2f05 | 2902 | -- Add an expression that assigns null. This node is needed by |
2903 | -- Apply_Compile_Time_Constraint_Error, which will replace this with | |
2904 | -- a Constraint_Error node. | |
13dbf220 | 2905 | |
2906 | Set_Expression (N, Make_Null (Sloc (N))); | |
2907 | Set_Etype (Expression (N), Etype (Defining_Identifier (N))); | |
5329ca64 | 2908 | |
13dbf220 | 2909 | Apply_Compile_Time_Constraint_Error |
2910 | (N => Expression (N), | |
2911 | Msg => "(Ada 2005) null-excluding objects must be initialized?", | |
2912 | Reason => CE_Null_Not_Allowed); | |
2913 | end if; | |
5329ca64 | 2914 | |
cc60bd16 | 2915 | -- Check that a null-excluding component, formal or object is not being |
2916 | -- assigned a null value. Otherwise generate a warning message and | |
2c145f84 | 2917 | -- replace Expression (N) by an N_Constraint_Error node. |
13dbf220 | 2918 | |
0577b0b1 | 2919 | if K /= N_Function_Specification then |
2920 | Expr := Expression (N); | |
5329ca64 | 2921 | |
2af58f67 | 2922 | if Present (Expr) and then Known_Null (Expr) then |
13dbf220 | 2923 | case K is |
0577b0b1 | 2924 | when N_Component_Declaration | |
2925 | N_Discriminant_Specification => | |
7189d17f | 2926 | Apply_Compile_Time_Constraint_Error |
0577b0b1 | 2927 | (N => Expr, |
2af58f67 | 2928 | Msg => "(Ada 2005) null not allowed " & |
0577b0b1 | 2929 | "in null-excluding components?", |
2930 | Reason => CE_Null_Not_Allowed); | |
5329ca64 | 2931 | |
0577b0b1 | 2932 | when N_Object_Declaration => |
7189d17f | 2933 | Apply_Compile_Time_Constraint_Error |
0577b0b1 | 2934 | (N => Expr, |
2af58f67 | 2935 | Msg => "(Ada 2005) null not allowed " & |
0577b0b1 | 2936 | "in null-excluding objects?", |
2937 | Reason => CE_Null_Not_Allowed); | |
5329ca64 | 2938 | |
0577b0b1 | 2939 | when N_Parameter_Specification => |
7189d17f | 2940 | Apply_Compile_Time_Constraint_Error |
0577b0b1 | 2941 | (N => Expr, |
2af58f67 | 2942 | Msg => "(Ada 2005) null not allowed " & |
0577b0b1 | 2943 | "in null-excluding formals?", |
2944 | Reason => CE_Null_Not_Allowed); | |
13dbf220 | 2945 | |
2946 | when others => | |
2947 | null; | |
5329ca64 | 2948 | end case; |
2949 | end if; | |
0577b0b1 | 2950 | end if; |
fa7497e8 | 2951 | end Null_Exclusion_Static_Checks; |
2952 | ||
9dfe12ae | 2953 | ---------------------------------- |
2954 | -- Conditional_Statements_Begin -- | |
2955 | ---------------------------------- | |
2956 | ||
2957 | procedure Conditional_Statements_Begin is | |
2958 | begin | |
2959 | Saved_Checks_TOS := Saved_Checks_TOS + 1; | |
2960 | ||
feff2f05 | 2961 | -- If stack overflows, kill all checks, that way we know to simply reset |
2962 | -- the number of saved checks to zero on return. This should never occur | |
2963 | -- in practice. | |
9dfe12ae | 2964 | |
2965 | if Saved_Checks_TOS > Saved_Checks_Stack'Last then | |
2966 | Kill_All_Checks; | |
2967 | ||
feff2f05 | 2968 | -- In the normal case, we just make a new stack entry saving the current |
2969 | -- number of saved checks for a later restore. | |
9dfe12ae | 2970 | |
2971 | else | |
2972 | Saved_Checks_Stack (Saved_Checks_TOS) := Num_Saved_Checks; | |
2973 | ||
2974 | if Debug_Flag_CC then | |
2975 | w ("Conditional_Statements_Begin: Num_Saved_Checks = ", | |
2976 | Num_Saved_Checks); | |
2977 | end if; | |
2978 | end if; | |
2979 | end Conditional_Statements_Begin; | |
2980 | ||
2981 | -------------------------------- | |
2982 | -- Conditional_Statements_End -- | |
2983 | -------------------------------- | |
2984 | ||
2985 | procedure Conditional_Statements_End is | |
2986 | begin | |
2987 | pragma Assert (Saved_Checks_TOS > 0); | |
2988 | ||
feff2f05 | 2989 | -- If the saved checks stack overflowed, then we killed all checks, so |
2990 | -- setting the number of saved checks back to zero is correct. This | |
2991 | -- should never occur in practice. | |
9dfe12ae | 2992 | |
2993 | if Saved_Checks_TOS > Saved_Checks_Stack'Last then | |
2994 | Num_Saved_Checks := 0; | |
2995 | ||
feff2f05 | 2996 | -- In the normal case, restore the number of saved checks from the top |
2997 | -- stack entry. | |
9dfe12ae | 2998 | |
2999 | else | |
3000 | Num_Saved_Checks := Saved_Checks_Stack (Saved_Checks_TOS); | |
3001 | if Debug_Flag_CC then | |
3002 | w ("Conditional_Statements_End: Num_Saved_Checks = ", | |
3003 | Num_Saved_Checks); | |
3004 | end if; | |
3005 | end if; | |
3006 | ||
3007 | Saved_Checks_TOS := Saved_Checks_TOS - 1; | |
3008 | end Conditional_Statements_End; | |
3009 | ||
ee6ba406 | 3010 | --------------------- |
3011 | -- Determine_Range -- | |
3012 | --------------------- | |
3013 | ||
6af1bdbc | 3014 | Cache_Size : constant := 2 ** 10; |
ee6ba406 | 3015 | type Cache_Index is range 0 .. Cache_Size - 1; |
3016 | -- Determine size of below cache (power of 2 is more efficient!) | |
3017 | ||
3018 | Determine_Range_Cache_N : array (Cache_Index) of Node_Id; | |
9c486805 | 3019 | Determine_Range_Cache_V : array (Cache_Index) of Boolean; |
ee6ba406 | 3020 | Determine_Range_Cache_Lo : array (Cache_Index) of Uint; |
3021 | Determine_Range_Cache_Hi : array (Cache_Index) of Uint; | |
feff2f05 | 3022 | -- The above arrays are used to implement a small direct cache for |
3023 | -- Determine_Range calls. Because of the way Determine_Range recursively | |
3024 | -- traces subexpressions, and because overflow checking calls the routine | |
3025 | -- on the way up the tree, a quadratic behavior can otherwise be | |
3026 | -- encountered in large expressions. The cache entry for node N is stored | |
3027 | -- in the (N mod Cache_Size) entry, and can be validated by checking the | |
9c486805 | 3028 | -- actual node value stored there. The Range_Cache_V array records the |
3029 | -- setting of Assume_Valid for the cache entry. | |
ee6ba406 | 3030 | |
3031 | procedure Determine_Range | |
9c486805 | 3032 | (N : Node_Id; |
3033 | OK : out Boolean; | |
3034 | Lo : out Uint; | |
3035 | Hi : out Uint; | |
3036 | Assume_Valid : Boolean := False) | |
ee6ba406 | 3037 | is |
e254d721 | 3038 | Typ : Entity_Id := Etype (N); |
3039 | -- Type to use, may get reset to base type for possibly invalid entity | |
8880be85 | 3040 | |
3041 | Lo_Left : Uint; | |
3042 | Hi_Left : Uint; | |
3043 | -- Lo and Hi bounds of left operand | |
ee6ba406 | 3044 | |
ee6ba406 | 3045 | Lo_Right : Uint; |
ee6ba406 | 3046 | Hi_Right : Uint; |
8880be85 | 3047 | -- Lo and Hi bounds of right (or only) operand |
3048 | ||
3049 | Bound : Node_Id; | |
3050 | -- Temp variable used to hold a bound node | |
3051 | ||
3052 | Hbound : Uint; | |
3053 | -- High bound of base type of expression | |
3054 | ||
3055 | Lor : Uint; | |
3056 | Hir : Uint; | |
3057 | -- Refined values for low and high bounds, after tightening | |
3058 | ||
3059 | OK1 : Boolean; | |
3060 | -- Used in lower level calls to indicate if call succeeded | |
3061 | ||
3062 | Cindex : Cache_Index; | |
3063 | -- Used to search cache | |
ee6ba406 | 3064 | |
3065 | function OK_Operands return Boolean; | |
3066 | -- Used for binary operators. Determines the ranges of the left and | |
3067 | -- right operands, and if they are both OK, returns True, and puts | |
341bd953 | 3068 | -- the results in Lo_Right, Hi_Right, Lo_Left, Hi_Left. |
ee6ba406 | 3069 | |
3070 | ----------------- | |
3071 | -- OK_Operands -- | |
3072 | ----------------- | |
3073 | ||
3074 | function OK_Operands return Boolean is | |
3075 | begin | |
9c486805 | 3076 | Determine_Range |
3077 | (Left_Opnd (N), OK1, Lo_Left, Hi_Left, Assume_Valid); | |
ee6ba406 | 3078 | |
3079 | if not OK1 then | |
3080 | return False; | |
3081 | end if; | |
3082 | ||
9c486805 | 3083 | Determine_Range |
3084 | (Right_Opnd (N), OK1, Lo_Right, Hi_Right, Assume_Valid); | |
ee6ba406 | 3085 | return OK1; |
3086 | end OK_Operands; | |
3087 | ||
3088 | -- Start of processing for Determine_Range | |
3089 | ||
3090 | begin | |
3091 | -- Prevent junk warnings by initializing range variables | |
3092 | ||
3093 | Lo := No_Uint; | |
3094 | Hi := No_Uint; | |
3095 | Lor := No_Uint; | |
3096 | Hir := No_Uint; | |
3097 | ||
a781c0fc | 3098 | -- If type is not defined, we can't determine its range |
ee6ba406 | 3099 | |
a781c0fc | 3100 | if No (Typ) |
3101 | ||
3102 | -- We don't deal with anything except discrete types | |
3103 | ||
3104 | or else not Is_Discrete_Type (Typ) | |
3105 | ||
3106 | -- Ignore type for which an error has been posted, since range in | |
3107 | -- this case may well be a bogosity deriving from the error. Also | |
3108 | -- ignore if error posted on the reference node. | |
3109 | ||
3110 | or else Error_Posted (N) or else Error_Posted (Typ) | |
ee6ba406 | 3111 | then |
3112 | OK := False; | |
3113 | return; | |
3114 | end if; | |
3115 | ||
3116 | -- For all other cases, we can determine the range | |
3117 | ||
3118 | OK := True; | |
3119 | ||
feff2f05 | 3120 | -- If value is compile time known, then the possible range is the one |
3121 | -- value that we know this expression definitely has! | |
ee6ba406 | 3122 | |
3123 | if Compile_Time_Known_Value (N) then | |
3124 | Lo := Expr_Value (N); | |
3125 | Hi := Lo; | |
3126 | return; | |
3127 | end if; | |
3128 | ||
3129 | -- Return if already in the cache | |
3130 | ||
3131 | Cindex := Cache_Index (N mod Cache_Size); | |
3132 | ||
9c486805 | 3133 | if Determine_Range_Cache_N (Cindex) = N |
3134 | and then | |
3135 | Determine_Range_Cache_V (Cindex) = Assume_Valid | |
3136 | then | |
ee6ba406 | 3137 | Lo := Determine_Range_Cache_Lo (Cindex); |
3138 | Hi := Determine_Range_Cache_Hi (Cindex); | |
3139 | return; | |
3140 | end if; | |
3141 | ||
feff2f05 | 3142 | -- Otherwise, start by finding the bounds of the type of the expression, |
3143 | -- the value cannot be outside this range (if it is, then we have an | |
3144 | -- overflow situation, which is a separate check, we are talking here | |
3145 | -- only about the expression value). | |
ee6ba406 | 3146 | |
341bd953 | 3147 | -- First a check, never try to find the bounds of a generic type, since |
3148 | -- these bounds are always junk values, and it is only valid to look at | |
3149 | -- the bounds in an instance. | |
3150 | ||
3151 | if Is_Generic_Type (Typ) then | |
3152 | OK := False; | |
3153 | return; | |
3154 | end if; | |
3155 | ||
9c486805 | 3156 | -- First step, change to use base type unless we know the value is valid |
e254d721 | 3157 | |
9c486805 | 3158 | if (Is_Entity_Name (N) and then Is_Known_Valid (Entity (N))) |
3159 | or else Assume_No_Invalid_Values | |
3160 | or else Assume_Valid | |
e254d721 | 3161 | then |
9c486805 | 3162 | null; |
3163 | else | |
3164 | Typ := Underlying_Type (Base_Type (Typ)); | |
e254d721 | 3165 | end if; |
3166 | ||
feff2f05 | 3167 | -- We use the actual bound unless it is dynamic, in which case use the |
3168 | -- corresponding base type bound if possible. If we can't get a bound | |
3169 | -- then we figure we can't determine the range (a peculiar case, that | |
3170 | -- perhaps cannot happen, but there is no point in bombing in this | |
3171 | -- optimization circuit. | |
8880be85 | 3172 | |
3173 | -- First the low bound | |
ee6ba406 | 3174 | |
3175 | Bound := Type_Low_Bound (Typ); | |
3176 | ||
3177 | if Compile_Time_Known_Value (Bound) then | |
3178 | Lo := Expr_Value (Bound); | |
3179 | ||
3180 | elsif Compile_Time_Known_Value (Type_Low_Bound (Base_Type (Typ))) then | |
3181 | Lo := Expr_Value (Type_Low_Bound (Base_Type (Typ))); | |
3182 | ||
3183 | else | |
3184 | OK := False; | |
3185 | return; | |
3186 | end if; | |
3187 | ||
8880be85 | 3188 | -- Now the high bound |
3189 | ||
ee6ba406 | 3190 | Bound := Type_High_Bound (Typ); |
3191 | ||
8880be85 | 3192 | -- We need the high bound of the base type later on, and this should |
3193 | -- always be compile time known. Again, it is not clear that this | |
3194 | -- can ever be false, but no point in bombing. | |
ee6ba406 | 3195 | |
8880be85 | 3196 | if Compile_Time_Known_Value (Type_High_Bound (Base_Type (Typ))) then |
ee6ba406 | 3197 | Hbound := Expr_Value (Type_High_Bound (Base_Type (Typ))); |
3198 | Hi := Hbound; | |
3199 | ||
3200 | else | |
3201 | OK := False; | |
3202 | return; | |
3203 | end if; | |
3204 | ||
feff2f05 | 3205 | -- If we have a static subtype, then that may have a tighter bound so |
3206 | -- use the upper bound of the subtype instead in this case. | |
8880be85 | 3207 | |
3208 | if Compile_Time_Known_Value (Bound) then | |
3209 | Hi := Expr_Value (Bound); | |
3210 | end if; | |
3211 | ||
feff2f05 | 3212 | -- We may be able to refine this value in certain situations. If any |
3213 | -- refinement is possible, then Lor and Hir are set to possibly tighter | |
3214 | -- bounds, and OK1 is set to True. | |
ee6ba406 | 3215 | |
3216 | case Nkind (N) is | |
3217 | ||
3218 | -- For unary plus, result is limited by range of operand | |
3219 | ||
3220 | when N_Op_Plus => | |
9c486805 | 3221 | Determine_Range |
3222 | (Right_Opnd (N), OK1, Lor, Hir, Assume_Valid); | |
ee6ba406 | 3223 | |
3224 | -- For unary minus, determine range of operand, and negate it | |
3225 | ||
3226 | when N_Op_Minus => | |
9c486805 | 3227 | Determine_Range |
3228 | (Right_Opnd (N), OK1, Lo_Right, Hi_Right, Assume_Valid); | |
ee6ba406 | 3229 | |
3230 | if OK1 then | |
3231 | Lor := -Hi_Right; | |
3232 | Hir := -Lo_Right; | |
3233 | end if; | |
3234 | ||
3235 | -- For binary addition, get range of each operand and do the | |
3236 | -- addition to get the result range. | |
3237 | ||
3238 | when N_Op_Add => | |
3239 | if OK_Operands then | |
3240 | Lor := Lo_Left + Lo_Right; | |
3241 | Hir := Hi_Left + Hi_Right; | |
3242 | end if; | |
3243 | ||
feff2f05 | 3244 | -- Division is tricky. The only case we consider is where the right |
3245 | -- operand is a positive constant, and in this case we simply divide | |
3246 | -- the bounds of the left operand | |
ee6ba406 | 3247 | |
3248 | when N_Op_Divide => | |
3249 | if OK_Operands then | |
3250 | if Lo_Right = Hi_Right | |
3251 | and then Lo_Right > 0 | |
3252 | then | |
3253 | Lor := Lo_Left / Lo_Right; | |
3254 | Hir := Hi_Left / Lo_Right; | |
3255 | ||
3256 | else | |
3257 | OK1 := False; | |
3258 | end if; | |
3259 | end if; | |
3260 | ||
feff2f05 | 3261 | -- For binary subtraction, get range of each operand and do the worst |
3262 | -- case subtraction to get the result range. | |
ee6ba406 | 3263 | |
3264 | when N_Op_Subtract => | |
3265 | if OK_Operands then | |
3266 | Lor := Lo_Left - Hi_Right; | |
3267 | Hir := Hi_Left - Lo_Right; | |
3268 | end if; | |
3269 | ||
feff2f05 | 3270 | -- For MOD, if right operand is a positive constant, then result must |
3271 | -- be in the allowable range of mod results. | |
ee6ba406 | 3272 | |
3273 | when N_Op_Mod => | |
3274 | if OK_Operands then | |
9dfe12ae | 3275 | if Lo_Right = Hi_Right |
3276 | and then Lo_Right /= 0 | |
3277 | then | |
ee6ba406 | 3278 | if Lo_Right > 0 then |
3279 | Lor := Uint_0; | |
3280 | Hir := Lo_Right - 1; | |
3281 | ||
9dfe12ae | 3282 | else -- Lo_Right < 0 |
ee6ba406 | 3283 | Lor := Lo_Right + 1; |
3284 | Hir := Uint_0; | |
3285 | end if; | |
3286 | ||
3287 | else | |
3288 | OK1 := False; | |
3289 | end if; | |
3290 | end if; | |
3291 | ||
feff2f05 | 3292 | -- For REM, if right operand is a positive constant, then result must |
3293 | -- be in the allowable range of mod results. | |
ee6ba406 | 3294 | |
3295 | when N_Op_Rem => | |
3296 | if OK_Operands then | |
9dfe12ae | 3297 | if Lo_Right = Hi_Right |
3298 | and then Lo_Right /= 0 | |
3299 | then | |
ee6ba406 | 3300 | declare |
3301 | Dval : constant Uint := (abs Lo_Right) - 1; | |
3302 | ||
3303 | begin | |
3304 | -- The sign of the result depends on the sign of the | |
3305 | -- dividend (but not on the sign of the divisor, hence | |
3306 | -- the abs operation above). | |
3307 | ||
3308 | if Lo_Left < 0 then | |
3309 | Lor := -Dval; | |
3310 | else | |
3311 | Lor := Uint_0; | |
3312 | end if; | |
3313 | ||
3314 | if Hi_Left < 0 then | |
3315 | Hir := Uint_0; | |
3316 | else | |
3317 | Hir := Dval; | |
3318 | end if; | |
3319 | end; | |
3320 | ||
3321 | else | |
3322 | OK1 := False; | |
3323 | end if; | |
3324 | end if; | |
3325 | ||
3326 | -- Attribute reference cases | |
3327 | ||
3328 | when N_Attribute_Reference => | |
3329 | case Attribute_Name (N) is | |
3330 | ||
3331 | -- For Pos/Val attributes, we can refine the range using the | |
ddbf7f2e | 3332 | -- possible range of values of the attribute expression. |
ee6ba406 | 3333 | |
3334 | when Name_Pos | Name_Val => | |
9c486805 | 3335 | Determine_Range |
3336 | (First (Expressions (N)), OK1, Lor, Hir, Assume_Valid); | |
ee6ba406 | 3337 | |
3338 | -- For Length attribute, use the bounds of the corresponding | |
3339 | -- index type to refine the range. | |
3340 | ||
3341 | when Name_Length => | |
3342 | declare | |
3343 | Atyp : Entity_Id := Etype (Prefix (N)); | |
3344 | Inum : Nat; | |
3345 | Indx : Node_Id; | |
3346 | ||
3347 | LL, LU : Uint; | |
3348 | UL, UU : Uint; | |
3349 | ||
3350 | begin | |
3351 | if Is_Access_Type (Atyp) then | |
3352 | Atyp := Designated_Type (Atyp); | |
3353 | end if; | |
3354 | ||
3355 | -- For string literal, we know exact value | |
3356 | ||
3357 | if Ekind (Atyp) = E_String_Literal_Subtype then | |
3358 | OK := True; | |
3359 | Lo := String_Literal_Length (Atyp); | |
3360 | Hi := String_Literal_Length (Atyp); | |
3361 | return; | |
3362 | end if; | |
3363 | ||
3364 | -- Otherwise check for expression given | |
3365 | ||
3366 | if No (Expressions (N)) then | |
3367 | Inum := 1; | |
3368 | else | |
3369 | Inum := | |
3370 | UI_To_Int (Expr_Value (First (Expressions (N)))); | |
3371 | end if; | |
3372 | ||
3373 | Indx := First_Index (Atyp); | |
3374 | for J in 2 .. Inum loop | |
3375 | Indx := Next_Index (Indx); | |
3376 | end loop; | |
3377 | ||
3378 | Determine_Range | |
9c486805 | 3379 | (Type_Low_Bound (Etype (Indx)), OK1, LL, LU, |
3380 | Assume_Valid); | |
ee6ba406 | 3381 | |
3382 | if OK1 then | |
3383 | Determine_Range | |
9c486805 | 3384 | (Type_High_Bound (Etype (Indx)), OK1, UL, UU, |
3385 | Assume_Valid); | |
ee6ba406 | 3386 | |
3387 | if OK1 then | |
3388 | ||
3389 | -- The maximum value for Length is the biggest | |
3390 | -- possible gap between the values of the bounds. | |
3391 | -- But of course, this value cannot be negative. | |
3392 | ||
9c486805 | 3393 | Hir := UI_Max (Uint_0, UU - LL + 1); |
ee6ba406 | 3394 | |
3395 | -- For constrained arrays, the minimum value for | |
3396 | -- Length is taken from the actual value of the | |
3397 | -- bounds, since the index will be exactly of | |
3398 | -- this subtype. | |
3399 | ||
3400 | if Is_Constrained (Atyp) then | |
9c486805 | 3401 | Lor := UI_Max (Uint_0, UL - LU + 1); |
ee6ba406 | 3402 | |
3403 | -- For an unconstrained array, the minimum value | |
3404 | -- for length is always zero. | |
3405 | ||
3406 | else | |
3407 | Lor := Uint_0; | |
3408 | end if; | |
3409 | end if; | |
3410 | end if; | |
3411 | end; | |
3412 | ||
3413 | -- No special handling for other attributes | |
3414 | -- Probably more opportunities exist here ??? | |
3415 | ||
3416 | when others => | |
3417 | OK1 := False; | |
3418 | ||
3419 | end case; | |
3420 | ||
feff2f05 | 3421 | -- For type conversion from one discrete type to another, we can |
3422 | -- refine the range using the converted value. | |
ee6ba406 | 3423 | |
3424 | when N_Type_Conversion => | |
9c486805 | 3425 | Determine_Range (Expression (N), OK1, Lor, Hir, Assume_Valid); |
ee6ba406 | 3426 | |
3427 | -- Nothing special to do for all other expression kinds | |
3428 | ||
3429 | when others => | |
3430 | OK1 := False; | |
3431 | Lor := No_Uint; | |
3432 | Hir := No_Uint; | |
3433 | end case; | |
3434 | ||
3435 | -- At this stage, if OK1 is true, then we know that the actual | |
3436 | -- result of the computed expression is in the range Lor .. Hir. | |
3437 | -- We can use this to restrict the possible range of results. | |
3438 | ||
3439 | if OK1 then | |
3440 | ||
3441 | -- If the refined value of the low bound is greater than the | |
3442 | -- type high bound, then reset it to the more restrictive | |
3443 | -- value. However, we do NOT do this for the case of a modular | |
3444 | -- type where the possible upper bound on the value is above the | |
3445 | -- base type high bound, because that means the result could wrap. | |
3446 | ||
3447 | if Lor > Lo | |
3448 | and then not (Is_Modular_Integer_Type (Typ) | |
3449 | and then Hir > Hbound) | |
3450 | then | |
3451 | Lo := Lor; | |
3452 | end if; | |
3453 | ||
3454 | -- Similarly, if the refined value of the high bound is less | |
3455 | -- than the value so far, then reset it to the more restrictive | |
3456 | -- value. Again, we do not do this if the refined low bound is | |
3457 | -- negative for a modular type, since this would wrap. | |
3458 | ||
3459 | if Hir < Hi | |
3460 | and then not (Is_Modular_Integer_Type (Typ) | |
3461 | and then Lor < Uint_0) | |
3462 | then | |
3463 | Hi := Hir; | |
3464 | end if; | |
3465 | end if; | |
3466 | ||
3467 | -- Set cache entry for future call and we are all done | |
3468 | ||
3469 | Determine_Range_Cache_N (Cindex) := N; | |
9c486805 | 3470 | Determine_Range_Cache_V (Cindex) := Assume_Valid; |
ee6ba406 | 3471 | Determine_Range_Cache_Lo (Cindex) := Lo; |
3472 | Determine_Range_Cache_Hi (Cindex) := Hi; | |
3473 | return; | |
3474 | ||
3475 | -- If any exception occurs, it means that we have some bug in the compiler | |
3476 | -- possibly triggered by a previous error, or by some unforseen peculiar | |
3477 | -- occurrence. However, this is only an optimization attempt, so there is | |
3478 | -- really no point in crashing the compiler. Instead we just decide, too | |
3479 | -- bad, we can't figure out a range in this case after all. | |
3480 | ||
3481 | exception | |
3482 | when others => | |
3483 | ||
3484 | -- Debug flag K disables this behavior (useful for debugging) | |
3485 | ||
3486 | if Debug_Flag_K then | |
3487 | raise; | |
3488 | else | |
3489 | OK := False; | |
3490 | Lo := No_Uint; | |
3491 | Hi := No_Uint; | |
3492 | return; | |
3493 | end if; | |
ee6ba406 | 3494 | end Determine_Range; |
3495 | ||
3496 | ------------------------------------ | |
3497 | -- Discriminant_Checks_Suppressed -- | |
3498 | ------------------------------------ | |
3499 | ||
3500 | function Discriminant_Checks_Suppressed (E : Entity_Id) return Boolean is | |
3501 | begin | |
9dfe12ae | 3502 | if Present (E) then |
3503 | if Is_Unchecked_Union (E) then | |
3504 | return True; | |
3505 | elsif Checks_May_Be_Suppressed (E) then | |
3506 | return Is_Check_Suppressed (E, Discriminant_Check); | |
3507 | end if; | |
3508 | end if; | |
3509 | ||
3510 | return Scope_Suppress (Discriminant_Check); | |
ee6ba406 | 3511 | end Discriminant_Checks_Suppressed; |
3512 | ||
3513 | -------------------------------- | |
3514 | -- Division_Checks_Suppressed -- | |
3515 | -------------------------------- | |
3516 | ||
3517 | function Division_Checks_Suppressed (E : Entity_Id) return Boolean is | |
3518 | begin | |
9dfe12ae | 3519 | if Present (E) and then Checks_May_Be_Suppressed (E) then |
3520 | return Is_Check_Suppressed (E, Division_Check); | |
3521 | else | |
3522 | return Scope_Suppress (Division_Check); | |
3523 | end if; | |
ee6ba406 | 3524 | end Division_Checks_Suppressed; |
3525 | ||
3526 | ----------------------------------- | |
3527 | -- Elaboration_Checks_Suppressed -- | |
3528 | ----------------------------------- | |
3529 | ||
3530 | function Elaboration_Checks_Suppressed (E : Entity_Id) return Boolean is | |
3531 | begin | |
38f5559f | 3532 | -- The complication in this routine is that if we are in the dynamic |
3533 | -- model of elaboration, we also check All_Checks, since All_Checks | |
3534 | -- does not set Elaboration_Check explicitly. | |
3535 | ||
9dfe12ae | 3536 | if Present (E) then |
3537 | if Kill_Elaboration_Checks (E) then | |
3538 | return True; | |
38f5559f | 3539 | |
9dfe12ae | 3540 | elsif Checks_May_Be_Suppressed (E) then |
38f5559f | 3541 | if Is_Check_Suppressed (E, Elaboration_Check) then |
3542 | return True; | |
3543 | elsif Dynamic_Elaboration_Checks then | |
3544 | return Is_Check_Suppressed (E, All_Checks); | |
3545 | else | |
3546 | return False; | |
3547 | end if; | |
9dfe12ae | 3548 | end if; |
3549 | end if; | |
3550 | ||
38f5559f | 3551 | if Scope_Suppress (Elaboration_Check) then |
3552 | return True; | |
3553 | elsif Dynamic_Elaboration_Checks then | |
3554 | return Scope_Suppress (All_Checks); | |
3555 | else | |
3556 | return False; | |
3557 | end if; | |
ee6ba406 | 3558 | end Elaboration_Checks_Suppressed; |
3559 | ||
9dfe12ae | 3560 | --------------------------- |
3561 | -- Enable_Overflow_Check -- | |
3562 | --------------------------- | |
3563 | ||
3564 | procedure Enable_Overflow_Check (N : Node_Id) is | |
3565 | Typ : constant Entity_Id := Base_Type (Etype (N)); | |
3566 | Chk : Nat; | |
3567 | OK : Boolean; | |
3568 | Ent : Entity_Id; | |
3569 | Ofs : Uint; | |
3570 | Lo : Uint; | |
3571 | Hi : Uint; | |
ee6ba406 | 3572 | |
ee6ba406 | 3573 | begin |
9dfe12ae | 3574 | if Debug_Flag_CC then |
3575 | w ("Enable_Overflow_Check for node ", Int (N)); | |
3576 | Write_Str (" Source location = "); | |
3577 | wl (Sloc (N)); | |
00c403ee | 3578 | pg (Union_Id (N)); |
ee6ba406 | 3579 | end if; |
ee6ba406 | 3580 | |
75209ec5 | 3581 | -- No check if overflow checks suppressed for type of node |
3582 | ||
3583 | if Present (Etype (N)) | |
3584 | and then Overflow_Checks_Suppressed (Etype (N)) | |
3585 | then | |
3586 | return; | |
3587 | ||
49260fa5 | 3588 | -- Nothing to do for unsigned integer types, which do not overflow |
3589 | ||
3590 | elsif Is_Modular_Integer_Type (Typ) then | |
3591 | return; | |
3592 | ||
feff2f05 | 3593 | -- Nothing to do if the range of the result is known OK. We skip this |
3594 | -- for conversions, since the caller already did the check, and in any | |
3595 | -- case the condition for deleting the check for a type conversion is | |
cc60bd16 | 3596 | -- different. |
ee6ba406 | 3597 | |
75209ec5 | 3598 | elsif Nkind (N) /= N_Type_Conversion then |
9c486805 | 3599 | Determine_Range (N, OK, Lo, Hi, Assume_Valid => True); |
ee6ba406 | 3600 | |
cc60bd16 | 3601 | -- Note in the test below that we assume that the range is not OK |
3602 | -- if a bound of the range is equal to that of the type. That's not | |
3603 | -- quite accurate but we do this for the following reasons: | |
ee6ba406 | 3604 | |
9dfe12ae | 3605 | -- a) The way that Determine_Range works, it will typically report |
3606 | -- the bounds of the value as being equal to the bounds of the | |
3607 | -- type, because it either can't tell anything more precise, or | |
3608 | -- does not think it is worth the effort to be more precise. | |
ee6ba406 | 3609 | |
9dfe12ae | 3610 | -- b) It is very unusual to have a situation in which this would |
3611 | -- generate an unnecessary overflow check (an example would be | |
3612 | -- a subtype with a range 0 .. Integer'Last - 1 to which the | |
cc60bd16 | 3613 | -- literal value one is added). |
ee6ba406 | 3614 | |
9dfe12ae | 3615 | -- c) The alternative is a lot of special casing in this routine |
3616 | -- which would partially duplicate Determine_Range processing. | |
ee6ba406 | 3617 | |
9dfe12ae | 3618 | if OK |
3619 | and then Lo > Expr_Value (Type_Low_Bound (Typ)) | |
3620 | and then Hi < Expr_Value (Type_High_Bound (Typ)) | |
3621 | then | |
3622 | if Debug_Flag_CC then | |
3623 | w ("No overflow check required"); | |
3624 | end if; | |
3625 | ||
3626 | return; | |
3627 | end if; | |
3628 | end if; | |
3629 | ||
feff2f05 | 3630 | -- If not in optimizing mode, set flag and we are done. We are also done |
3631 | -- (and just set the flag) if the type is not a discrete type, since it | |
3632 | -- is not worth the effort to eliminate checks for other than discrete | |
3633 | -- types. In addition, we take this same path if we have stored the | |
3634 | -- maximum number of checks possible already (a very unlikely situation, | |
3635 | -- but we do not want to blow up!) | |
9dfe12ae | 3636 | |
3637 | if Optimization_Level = 0 | |
3638 | or else not Is_Discrete_Type (Etype (N)) | |
3639 | or else Num_Saved_Checks = Saved_Checks'Last | |
ee6ba406 | 3640 | then |
00c403ee | 3641 | Activate_Overflow_Check (N); |
9dfe12ae | 3642 | |
3643 | if Debug_Flag_CC then | |
3644 | w ("Optimization off"); | |
3645 | end if; | |
3646 | ||
ee6ba406 | 3647 | return; |
9dfe12ae | 3648 | end if; |
ee6ba406 | 3649 | |
9dfe12ae | 3650 | -- Otherwise evaluate and check the expression |
3651 | ||
3652 | Find_Check | |
3653 | (Expr => N, | |
3654 | Check_Type => 'O', | |
3655 | Target_Type => Empty, | |
3656 | Entry_OK => OK, | |
3657 | Check_Num => Chk, | |
3658 | Ent => Ent, | |
3659 | Ofs => Ofs); | |
3660 | ||
3661 | if Debug_Flag_CC then | |
3662 | w ("Called Find_Check"); | |
3663 | w (" OK = ", OK); | |
3664 | ||
3665 | if OK then | |
3666 | w (" Check_Num = ", Chk); | |
3667 | w (" Ent = ", Int (Ent)); | |
3668 | Write_Str (" Ofs = "); | |
3669 | pid (Ofs); | |
3670 | end if; | |
3671 | end if; | |
ee6ba406 | 3672 | |
9dfe12ae | 3673 | -- If check is not of form to optimize, then set flag and we are done |
3674 | ||
3675 | if not OK then | |
00c403ee | 3676 | Activate_Overflow_Check (N); |
ee6ba406 | 3677 | return; |
9dfe12ae | 3678 | end if; |
ee6ba406 | 3679 | |
9dfe12ae | 3680 | -- If check is already performed, then return without setting flag |
3681 | ||
3682 | if Chk /= 0 then | |
3683 | if Debug_Flag_CC then | |
3684 | w ("Check suppressed!"); | |
3685 | end if; | |
ee6ba406 | 3686 | |
ee6ba406 | 3687 | return; |
9dfe12ae | 3688 | end if; |
ee6ba406 | 3689 | |
9dfe12ae | 3690 | -- Here we will make a new entry for the new check |
3691 | ||
00c403ee | 3692 | Activate_Overflow_Check (N); |
9dfe12ae | 3693 | Num_Saved_Checks := Num_Saved_Checks + 1; |
3694 | Saved_Checks (Num_Saved_Checks) := | |
3695 | (Killed => False, | |
3696 | Entity => Ent, | |
3697 | Offset => Ofs, | |
3698 | Check_Type => 'O', | |
3699 | Target_Type => Empty); | |
3700 | ||
3701 | if Debug_Flag_CC then | |
3702 | w ("Make new entry, check number = ", Num_Saved_Checks); | |
3703 | w (" Entity = ", Int (Ent)); | |
3704 | Write_Str (" Offset = "); | |
3705 | pid (Ofs); | |
3706 | w (" Check_Type = O"); | |
3707 | w (" Target_Type = Empty"); | |
3708 | end if; | |
ee6ba406 | 3709 | |
feff2f05 | 3710 | -- If we get an exception, then something went wrong, probably because of |
3711 | -- an error in the structure of the tree due to an incorrect program. Or it | |
3712 | -- may be a bug in the optimization circuit. In either case the safest | |
3713 | -- thing is simply to set the check flag unconditionally. | |
9dfe12ae | 3714 | |
3715 | exception | |
3716 | when others => | |
00c403ee | 3717 | Activate_Overflow_Check (N); |
9dfe12ae | 3718 | |
3719 | if Debug_Flag_CC then | |
3720 | w (" exception occurred, overflow flag set"); | |
3721 | end if; | |
3722 | ||
3723 | return; | |
3724 | end Enable_Overflow_Check; | |
3725 | ||
3726 | ------------------------ | |
3727 | -- Enable_Range_Check -- | |
3728 | ------------------------ | |
3729 | ||
3730 | procedure Enable_Range_Check (N : Node_Id) is | |
3731 | Chk : Nat; | |
3732 | OK : Boolean; | |
3733 | Ent : Entity_Id; | |
3734 | Ofs : Uint; | |
3735 | Ttyp : Entity_Id; | |
3736 | P : Node_Id; | |
3737 | ||
3738 | begin | |
feff2f05 | 3739 | -- Return if unchecked type conversion with range check killed. In this |
3740 | -- case we never set the flag (that's what Kill_Range_Check is about!) | |
9dfe12ae | 3741 | |
3742 | if Nkind (N) = N_Unchecked_Type_Conversion | |
3743 | and then Kill_Range_Check (N) | |
ee6ba406 | 3744 | then |
3745 | return; | |
9dfe12ae | 3746 | end if; |
ee6ba406 | 3747 | |
0577b0b1 | 3748 | -- Check for various cases where we should suppress the range check |
3749 | ||
3750 | -- No check if range checks suppressed for type of node | |
3751 | ||
3752 | if Present (Etype (N)) | |
3753 | and then Range_Checks_Suppressed (Etype (N)) | |
3754 | then | |
3755 | return; | |
3756 | ||
3757 | -- No check if node is an entity name, and range checks are suppressed | |
3758 | -- for this entity, or for the type of this entity. | |
3759 | ||
3760 | elsif Is_Entity_Name (N) | |
3761 | and then (Range_Checks_Suppressed (Entity (N)) | |
3762 | or else Range_Checks_Suppressed (Etype (Entity (N)))) | |
3763 | then | |
3764 | return; | |
3765 | ||
3766 | -- No checks if index of array, and index checks are suppressed for | |
3767 | -- the array object or the type of the array. | |
3768 | ||
3769 | elsif Nkind (Parent (N)) = N_Indexed_Component then | |
3770 | declare | |
3771 | Pref : constant Node_Id := Prefix (Parent (N)); | |
3772 | begin | |
3773 | if Is_Entity_Name (Pref) | |
3774 | and then Index_Checks_Suppressed (Entity (Pref)) | |
3775 | then | |
3776 | return; | |
3777 | elsif Index_Checks_Suppressed (Etype (Pref)) then | |
3778 | return; | |
3779 | end if; | |
3780 | end; | |
3781 | end if; | |
3782 | ||
9dfe12ae | 3783 | -- Debug trace output |
ee6ba406 | 3784 | |
9dfe12ae | 3785 | if Debug_Flag_CC then |
3786 | w ("Enable_Range_Check for node ", Int (N)); | |
3787 | Write_Str (" Source location = "); | |
3788 | wl (Sloc (N)); | |
00c403ee | 3789 | pg (Union_Id (N)); |
9dfe12ae | 3790 | end if; |
3791 | ||
feff2f05 | 3792 | -- If not in optimizing mode, set flag and we are done. We are also done |
3793 | -- (and just set the flag) if the type is not a discrete type, since it | |
3794 | -- is not worth the effort to eliminate checks for other than discrete | |
3795 | -- types. In addition, we take this same path if we have stored the | |
3796 | -- maximum number of checks possible already (a very unlikely situation, | |
3797 | -- but we do not want to blow up!) | |
9dfe12ae | 3798 | |
3799 | if Optimization_Level = 0 | |
3800 | or else No (Etype (N)) | |
3801 | or else not Is_Discrete_Type (Etype (N)) | |
3802 | or else Num_Saved_Checks = Saved_Checks'Last | |
ee6ba406 | 3803 | then |
00c403ee | 3804 | Activate_Range_Check (N); |
9dfe12ae | 3805 | |
3806 | if Debug_Flag_CC then | |
3807 | w ("Optimization off"); | |
3808 | end if; | |
3809 | ||
ee6ba406 | 3810 | return; |
9dfe12ae | 3811 | end if; |
ee6ba406 | 3812 | |
9dfe12ae | 3813 | -- Otherwise find out the target type |
ee6ba406 | 3814 | |
9dfe12ae | 3815 | P := Parent (N); |
ee6ba406 | 3816 | |
9dfe12ae | 3817 | -- For assignment, use left side subtype |
3818 | ||
3819 | if Nkind (P) = N_Assignment_Statement | |
3820 | and then Expression (P) = N | |
3821 | then | |
3822 | Ttyp := Etype (Name (P)); | |
3823 | ||
3824 | -- For indexed component, use subscript subtype | |
3825 | ||
3826 | elsif Nkind (P) = N_Indexed_Component then | |
3827 | declare | |
3828 | Atyp : Entity_Id; | |
3829 | Indx : Node_Id; | |
3830 | Subs : Node_Id; | |
3831 | ||
3832 | begin | |
3833 | Atyp := Etype (Prefix (P)); | |
3834 | ||
3835 | if Is_Access_Type (Atyp) then | |
3836 | Atyp := Designated_Type (Atyp); | |
f07ea091 | 3837 | |
3838 | -- If the prefix is an access to an unconstrained array, | |
feff2f05 | 3839 | -- perform check unconditionally: it depends on the bounds of |
3840 | -- an object and we cannot currently recognize whether the test | |
3841 | -- may be redundant. | |
f07ea091 | 3842 | |
3843 | if not Is_Constrained (Atyp) then | |
00c403ee | 3844 | Activate_Range_Check (N); |
f07ea091 | 3845 | return; |
3846 | end if; | |
7189d17f | 3847 | |
feff2f05 | 3848 | -- Ditto if the prefix is an explicit dereference whose designated |
3849 | -- type is unconstrained. | |
7189d17f | 3850 | |
3851 | elsif Nkind (Prefix (P)) = N_Explicit_Dereference | |
3852 | and then not Is_Constrained (Atyp) | |
3853 | then | |
00c403ee | 3854 | Activate_Range_Check (N); |
7189d17f | 3855 | return; |
9dfe12ae | 3856 | end if; |
3857 | ||
3858 | Indx := First_Index (Atyp); | |
3859 | Subs := First (Expressions (P)); | |
3860 | loop | |
3861 | if Subs = N then | |
3862 | Ttyp := Etype (Indx); | |
3863 | exit; | |
3864 | end if; | |
3865 | ||
3866 | Next_Index (Indx); | |
3867 | Next (Subs); | |
3868 | end loop; | |
3869 | end; | |
3870 | ||
3871 | -- For now, ignore all other cases, they are not so interesting | |
3872 | ||
3873 | else | |
3874 | if Debug_Flag_CC then | |
3875 | w (" target type not found, flag set"); | |
3876 | end if; | |
3877 | ||
00c403ee | 3878 | Activate_Range_Check (N); |
9dfe12ae | 3879 | return; |
3880 | end if; | |
3881 | ||
3882 | -- Evaluate and check the expression | |
3883 | ||
3884 | Find_Check | |
3885 | (Expr => N, | |
3886 | Check_Type => 'R', | |
3887 | Target_Type => Ttyp, | |
3888 | Entry_OK => OK, | |
3889 | Check_Num => Chk, | |
3890 | Ent => Ent, | |
3891 | Ofs => Ofs); | |
3892 | ||
3893 | if Debug_Flag_CC then | |
3894 | w ("Called Find_Check"); | |
3895 | w ("Target_Typ = ", Int (Ttyp)); | |
3896 | w (" OK = ", OK); | |
3897 | ||
3898 | if OK then | |
3899 | w (" Check_Num = ", Chk); | |
3900 | w (" Ent = ", Int (Ent)); | |
3901 | Write_Str (" Ofs = "); | |
3902 | pid (Ofs); | |
3903 | end if; | |
3904 | end if; | |
3905 | ||
3906 | -- If check is not of form to optimize, then set flag and we are done | |
3907 | ||
3908 | if not OK then | |
3909 | if Debug_Flag_CC then | |
3910 | w (" expression not of optimizable type, flag set"); | |
3911 | end if; | |
3912 | ||
00c403ee | 3913 | Activate_Range_Check (N); |
9dfe12ae | 3914 | return; |
3915 | end if; | |
3916 | ||
3917 | -- If check is already performed, then return without setting flag | |
3918 | ||
3919 | if Chk /= 0 then | |
3920 | if Debug_Flag_CC then | |
3921 | w ("Check suppressed!"); | |
3922 | end if; | |
3923 | ||
3924 | return; | |
3925 | end if; | |
3926 | ||
3927 | -- Here we will make a new entry for the new check | |
3928 | ||
00c403ee | 3929 | Activate_Range_Check (N); |
9dfe12ae | 3930 | Num_Saved_Checks := Num_Saved_Checks + 1; |
3931 | Saved_Checks (Num_Saved_Checks) := | |
3932 | (Killed => False, | |
3933 | Entity => Ent, | |
3934 | Offset => Ofs, | |
3935 | Check_Type => 'R', | |
3936 | Target_Type => Ttyp); | |
3937 | ||
3938 | if Debug_Flag_CC then | |
3939 | w ("Make new entry, check number = ", Num_Saved_Checks); | |
3940 | w (" Entity = ", Int (Ent)); | |
3941 | Write_Str (" Offset = "); | |
3942 | pid (Ofs); | |
3943 | w (" Check_Type = R"); | |
3944 | w (" Target_Type = ", Int (Ttyp)); | |
00c403ee | 3945 | pg (Union_Id (Ttyp)); |
9dfe12ae | 3946 | end if; |
3947 | ||
feff2f05 | 3948 | -- If we get an exception, then something went wrong, probably because of |
3949 | -- an error in the structure of the tree due to an incorrect program. Or | |
3950 | -- it may be a bug in the optimization circuit. In either case the safest | |
3951 | -- thing is simply to set the check flag unconditionally. | |
9dfe12ae | 3952 | |
3953 | exception | |
3954 | when others => | |
00c403ee | 3955 | Activate_Range_Check (N); |
9dfe12ae | 3956 | |
3957 | if Debug_Flag_CC then | |
3958 | w (" exception occurred, range flag set"); | |
3959 | end if; | |
3960 | ||
3961 | return; | |
3962 | end Enable_Range_Check; | |
3963 | ||
3964 | ------------------ | |
3965 | -- Ensure_Valid -- | |
3966 | ------------------ | |
3967 | ||
3968 | procedure Ensure_Valid (Expr : Node_Id; Holes_OK : Boolean := False) is | |
3969 | Typ : constant Entity_Id := Etype (Expr); | |
3970 | ||
3971 | begin | |
3972 | -- Ignore call if we are not doing any validity checking | |
3973 | ||
3974 | if not Validity_Checks_On then | |
3975 | return; | |
3976 | ||
0577b0b1 | 3977 | -- Ignore call if range or validity checks suppressed on entity or type |
9dfe12ae | 3978 | |
0577b0b1 | 3979 | elsif Range_Or_Validity_Checks_Suppressed (Expr) then |
9dfe12ae | 3980 | return; |
3981 | ||
feff2f05 | 3982 | -- No check required if expression is from the expander, we assume the |
3983 | -- expander will generate whatever checks are needed. Note that this is | |
3984 | -- not just an optimization, it avoids infinite recursions! | |
9dfe12ae | 3985 | |
3986 | -- Unchecked conversions must be checked, unless they are initialized | |
3987 | -- scalar values, as in a component assignment in an init proc. | |
3988 | ||
3989 | -- In addition, we force a check if Force_Validity_Checks is set | |
3990 | ||
3991 | elsif not Comes_From_Source (Expr) | |
3992 | and then not Force_Validity_Checks | |
3993 | and then (Nkind (Expr) /= N_Unchecked_Type_Conversion | |
3994 | or else Kill_Range_Check (Expr)) | |
3995 | then | |
3996 | return; | |
3997 | ||
3998 | -- No check required if expression is known to have valid value | |
3999 | ||
4000 | elsif Expr_Known_Valid (Expr) then | |
4001 | return; | |
4002 | ||
feff2f05 | 4003 | -- Ignore case of enumeration with holes where the flag is set not to |
4004 | -- worry about holes, since no special validity check is needed | |
9dfe12ae | 4005 | |
4006 | elsif Is_Enumeration_Type (Typ) | |
4007 | and then Has_Non_Standard_Rep (Typ) | |
4008 | and then Holes_OK | |
4009 | then | |
4010 | return; | |
4011 | ||
f2a06be9 | 4012 | -- No check required on the left-hand side of an assignment |
9dfe12ae | 4013 | |
4014 | elsif Nkind (Parent (Expr)) = N_Assignment_Statement | |
4015 | and then Expr = Name (Parent (Expr)) | |
4016 | then | |
4017 | return; | |
4018 | ||
38f5559f | 4019 | -- No check on a univeral real constant. The context will eventually |
4020 | -- convert it to a machine number for some target type, or report an | |
4021 | -- illegality. | |
4022 | ||
4023 | elsif Nkind (Expr) = N_Real_Literal | |
4024 | and then Etype (Expr) = Universal_Real | |
4025 | then | |
4026 | return; | |
4027 | ||
0577b0b1 | 4028 | -- If the expression denotes a component of a packed boolean arrray, |
4029 | -- no possible check applies. We ignore the old ACATS chestnuts that | |
4030 | -- involve Boolean range True..True. | |
4031 | ||
4032 | -- Note: validity checks are generated for expressions that yield a | |
4033 | -- scalar type, when it is possible to create a value that is outside of | |
4034 | -- the type. If this is a one-bit boolean no such value exists. This is | |
4035 | -- an optimization, and it also prevents compiler blowing up during the | |
4036 | -- elaboration of improperly expanded packed array references. | |
4037 | ||
4038 | elsif Nkind (Expr) = N_Indexed_Component | |
4039 | and then Is_Bit_Packed_Array (Etype (Prefix (Expr))) | |
4040 | and then Root_Type (Etype (Expr)) = Standard_Boolean | |
4041 | then | |
4042 | return; | |
4043 | ||
9dfe12ae | 4044 | -- An annoying special case. If this is an out parameter of a scalar |
4045 | -- type, then the value is not going to be accessed, therefore it is | |
4046 | -- inappropriate to do any validity check at the call site. | |
4047 | ||
4048 | else | |
4049 | -- Only need to worry about scalar types | |
4050 | ||
4051 | if Is_Scalar_Type (Typ) then | |
ee6ba406 | 4052 | declare |
4053 | P : Node_Id; | |
4054 | N : Node_Id; | |
4055 | E : Entity_Id; | |
4056 | F : Entity_Id; | |
4057 | A : Node_Id; | |
4058 | L : List_Id; | |
4059 | ||
4060 | begin | |
4061 | -- Find actual argument (which may be a parameter association) | |
4062 | -- and the parent of the actual argument (the call statement) | |
4063 | ||
4064 | N := Expr; | |
4065 | P := Parent (Expr); | |
4066 | ||
4067 | if Nkind (P) = N_Parameter_Association then | |
4068 | N := P; | |
4069 | P := Parent (N); | |
4070 | end if; | |
4071 | ||
feff2f05 | 4072 | -- Only need to worry if we are argument of a procedure call |
4073 | -- since functions don't have out parameters. If this is an | |
4074 | -- indirect or dispatching call, get signature from the | |
4075 | -- subprogram type. | |
ee6ba406 | 4076 | |
4077 | if Nkind (P) = N_Procedure_Call_Statement then | |
4078 | L := Parameter_Associations (P); | |
9dfe12ae | 4079 | |
4080 | if Is_Entity_Name (Name (P)) then | |
4081 | E := Entity (Name (P)); | |
4082 | else | |
4083 | pragma Assert (Nkind (Name (P)) = N_Explicit_Dereference); | |
4084 | E := Etype (Name (P)); | |
4085 | end if; | |
ee6ba406 | 4086 | |
feff2f05 | 4087 | -- Only need to worry if there are indeed actuals, and if |
4088 | -- this could be a procedure call, otherwise we cannot get a | |
4089 | -- match (either we are not an argument, or the mode of the | |
4090 | -- formal is not OUT). This test also filters out the | |
4091 | -- generic case. | |
ee6ba406 | 4092 | |
4093 | if Is_Non_Empty_List (L) | |
4094 | and then Is_Subprogram (E) | |
4095 | then | |
feff2f05 | 4096 | -- This is the loop through parameters, looking for an |
4097 | -- OUT parameter for which we are the argument. | |
ee6ba406 | 4098 | |
4099 | F := First_Formal (E); | |
4100 | A := First (L); | |
ee6ba406 | 4101 | while Present (F) loop |
4102 | if Ekind (F) = E_Out_Parameter and then A = N then | |
4103 | return; | |
4104 | end if; | |
4105 | ||
4106 | Next_Formal (F); | |
4107 | Next (A); | |
4108 | end loop; | |
4109 | end if; | |
4110 | end if; | |
4111 | end; | |
4112 | end if; | |
4113 | end if; | |
4114 | ||
0577b0b1 | 4115 | -- If we fall through, a validity check is required |
ee6ba406 | 4116 | |
4117 | Insert_Valid_Check (Expr); | |
ce7498d3 | 4118 | |
4119 | if Is_Entity_Name (Expr) | |
4120 | and then Safe_To_Capture_Value (Expr, Entity (Expr)) | |
4121 | then | |
4122 | Set_Is_Known_Valid (Entity (Expr)); | |
4123 | end if; | |
ee6ba406 | 4124 | end Ensure_Valid; |
4125 | ||
4126 | ---------------------- | |
4127 | -- Expr_Known_Valid -- | |
4128 | ---------------------- | |
4129 | ||
4130 | function Expr_Known_Valid (Expr : Node_Id) return Boolean is | |
4131 | Typ : constant Entity_Id := Etype (Expr); | |
4132 | ||
4133 | begin | |
feff2f05 | 4134 | -- Non-scalar types are always considered valid, since they never give |
4135 | -- rise to the issues of erroneous or bounded error behavior that are | |
4136 | -- the concern. In formal reference manual terms the notion of validity | |
4137 | -- only applies to scalar types. Note that even when packed arrays are | |
4138 | -- represented using modular types, they are still arrays semantically, | |
4139 | -- so they are also always valid (in particular, the unused bits can be | |
4140 | -- random rubbish without affecting the validity of the array value). | |
ee6ba406 | 4141 | |
fa814356 | 4142 | if not Is_Scalar_Type (Typ) or else Is_Packed_Array_Type (Typ) then |
ee6ba406 | 4143 | return True; |
4144 | ||
4145 | -- If no validity checking, then everything is considered valid | |
4146 | ||
4147 | elsif not Validity_Checks_On then | |
4148 | return True; | |
4149 | ||
4150 | -- Floating-point types are considered valid unless floating-point | |
4151 | -- validity checks have been specifically turned on. | |
4152 | ||
4153 | elsif Is_Floating_Point_Type (Typ) | |
4154 | and then not Validity_Check_Floating_Point | |
4155 | then | |
4156 | return True; | |
4157 | ||
feff2f05 | 4158 | -- If the expression is the value of an object that is known to be |
4159 | -- valid, then clearly the expression value itself is valid. | |
ee6ba406 | 4160 | |
4161 | elsif Is_Entity_Name (Expr) | |
4162 | and then Is_Known_Valid (Entity (Expr)) | |
4163 | then | |
4164 | return True; | |
4165 | ||
0577b0b1 | 4166 | -- References to discriminants are always considered valid. The value |
4167 | -- of a discriminant gets checked when the object is built. Within the | |
4168 | -- record, we consider it valid, and it is important to do so, since | |
4169 | -- otherwise we can try to generate bogus validity checks which | |
feff2f05 | 4170 | -- reference discriminants out of scope. Discriminants of concurrent |
4171 | -- types are excluded for the same reason. | |
0577b0b1 | 4172 | |
4173 | elsif Is_Entity_Name (Expr) | |
feff2f05 | 4174 | and then Denotes_Discriminant (Expr, Check_Concurrent => True) |
0577b0b1 | 4175 | then |
4176 | return True; | |
4177 | ||
feff2f05 | 4178 | -- If the type is one for which all values are known valid, then we are |
4179 | -- sure that the value is valid except in the slightly odd case where | |
4180 | -- the expression is a reference to a variable whose size has been | |
4181 | -- explicitly set to a value greater than the object size. | |
ee6ba406 | 4182 | |
4183 | elsif Is_Known_Valid (Typ) then | |
4184 | if Is_Entity_Name (Expr) | |
4185 | and then Ekind (Entity (Expr)) = E_Variable | |
4186 | and then Esize (Entity (Expr)) > Esize (Typ) | |
4187 | then | |
4188 | return False; | |
4189 | else | |
4190 | return True; | |
4191 | end if; | |
4192 | ||
4193 | -- Integer and character literals always have valid values, where | |
4194 | -- appropriate these will be range checked in any case. | |
4195 | ||
4196 | elsif Nkind (Expr) = N_Integer_Literal | |
4197 | or else | |
4198 | Nkind (Expr) = N_Character_Literal | |
4199 | then | |
4200 | return True; | |
4201 | ||
4202 | -- If we have a type conversion or a qualification of a known valid | |
4203 | -- value, then the result will always be valid. | |
4204 | ||
4205 | elsif Nkind (Expr) = N_Type_Conversion | |
4206 | or else | |
4207 | Nkind (Expr) = N_Qualified_Expression | |
4208 | then | |
4209 | return Expr_Known_Valid (Expression (Expr)); | |
4210 | ||
38f5559f | 4211 | -- The result of any operator is always considered valid, since we |
4212 | -- assume the necessary checks are done by the operator. For operators | |
4213 | -- on floating-point operations, we must also check when the operation | |
4214 | -- is the right-hand side of an assignment, or is an actual in a call. | |
ee6ba406 | 4215 | |
0577b0b1 | 4216 | elsif Nkind (Expr) in N_Op then |
1d90d657 | 4217 | if Is_Floating_Point_Type (Typ) |
4218 | and then Validity_Check_Floating_Point | |
4219 | and then | |
4220 | (Nkind (Parent (Expr)) = N_Assignment_Statement | |
4221 | or else Nkind (Parent (Expr)) = N_Function_Call | |
4222 | or else Nkind (Parent (Expr)) = N_Parameter_Association) | |
4223 | then | |
4224 | return False; | |
4225 | else | |
4226 | return True; | |
4227 | end if; | |
4228 | ||
feff2f05 | 4229 | -- The result of a membership test is always valid, since it is true or |
4230 | -- false, there are no other possibilities. | |
0577b0b1 | 4231 | |
4232 | elsif Nkind (Expr) in N_Membership_Test then | |
4233 | return True; | |
4234 | ||
ee6ba406 | 4235 | -- For all other cases, we do not know the expression is valid |
4236 | ||
4237 | else | |
4238 | return False; | |
4239 | end if; | |
4240 | end Expr_Known_Valid; | |
4241 | ||
9dfe12ae | 4242 | ---------------- |
4243 | -- Find_Check -- | |
4244 | ---------------- | |
4245 | ||
4246 | procedure Find_Check | |
4247 | (Expr : Node_Id; | |
4248 | Check_Type : Character; | |
4249 | Target_Type : Entity_Id; | |
4250 | Entry_OK : out Boolean; | |
4251 | Check_Num : out Nat; | |
4252 | Ent : out Entity_Id; | |
4253 | Ofs : out Uint) | |
4254 | is | |
4255 | function Within_Range_Of | |
4256 | (Target_Type : Entity_Id; | |
314a23b6 | 4257 | Check_Type : Entity_Id) return Boolean; |
9dfe12ae | 4258 | -- Given a requirement for checking a range against Target_Type, and |
4259 | -- and a range Check_Type against which a check has already been made, | |
4260 | -- determines if the check against check type is sufficient to ensure | |
4261 | -- that no check against Target_Type is required. | |
4262 | ||
4263 | --------------------- | |
4264 | -- Within_Range_Of -- | |
4265 | --------------------- | |
4266 | ||
4267 | function Within_Range_Of | |
4268 | (Target_Type : Entity_Id; | |
314a23b6 | 4269 | Check_Type : Entity_Id) return Boolean |
9dfe12ae | 4270 | is |
4271 | begin | |
4272 | if Target_Type = Check_Type then | |
4273 | return True; | |
4274 | ||
4275 | else | |
4276 | declare | |
4277 | Tlo : constant Node_Id := Type_Low_Bound (Target_Type); | |
4278 | Thi : constant Node_Id := Type_High_Bound (Target_Type); | |
4279 | Clo : constant Node_Id := Type_Low_Bound (Check_Type); | |
4280 | Chi : constant Node_Id := Type_High_Bound (Check_Type); | |
4281 | ||
4282 | begin | |
4283 | if (Tlo = Clo | |
4284 | or else (Compile_Time_Known_Value (Tlo) | |
4285 | and then | |
4286 | Compile_Time_Known_Value (Clo) | |
4287 | and then | |
4288 | Expr_Value (Clo) >= Expr_Value (Tlo))) | |
4289 | and then | |
4290 | (Thi = Chi | |
4291 | or else (Compile_Time_Known_Value (Thi) | |
4292 | and then | |
4293 | Compile_Time_Known_Value (Chi) | |
4294 | and then | |
4295 | Expr_Value (Chi) <= Expr_Value (Clo))) | |
4296 | then | |
4297 | return True; | |
4298 | else | |
4299 | return False; | |
4300 | end if; | |
4301 | end; | |
4302 | end if; | |
4303 | end Within_Range_Of; | |
4304 | ||
4305 | -- Start of processing for Find_Check | |
4306 | ||
4307 | begin | |
f2a06be9 | 4308 | -- Establish default, to avoid warnings from GCC |
9dfe12ae | 4309 | |
4310 | Check_Num := 0; | |
4311 | ||
4312 | -- Case of expression is simple entity reference | |
4313 | ||
4314 | if Is_Entity_Name (Expr) then | |
4315 | Ent := Entity (Expr); | |
4316 | Ofs := Uint_0; | |
4317 | ||
4318 | -- Case of expression is entity + known constant | |
4319 | ||
4320 | elsif Nkind (Expr) = N_Op_Add | |
4321 | and then Compile_Time_Known_Value (Right_Opnd (Expr)) | |
4322 | and then Is_Entity_Name (Left_Opnd (Expr)) | |
4323 | then | |
4324 | Ent := Entity (Left_Opnd (Expr)); | |
4325 | Ofs := Expr_Value (Right_Opnd (Expr)); | |
4326 | ||
4327 | -- Case of expression is entity - known constant | |
4328 | ||
4329 | elsif Nkind (Expr) = N_Op_Subtract | |
4330 | and then Compile_Time_Known_Value (Right_Opnd (Expr)) | |
4331 | and then Is_Entity_Name (Left_Opnd (Expr)) | |
4332 | then | |
4333 | Ent := Entity (Left_Opnd (Expr)); | |
4334 | Ofs := UI_Negate (Expr_Value (Right_Opnd (Expr))); | |
4335 | ||
4336 | -- Any other expression is not of the right form | |
4337 | ||
4338 | else | |
4339 | Ent := Empty; | |
4340 | Ofs := Uint_0; | |
4341 | Entry_OK := False; | |
4342 | return; | |
4343 | end if; | |
4344 | ||
feff2f05 | 4345 | -- Come here with expression of appropriate form, check if entity is an |
4346 | -- appropriate one for our purposes. | |
9dfe12ae | 4347 | |
4348 | if (Ekind (Ent) = E_Variable | |
cc60bd16 | 4349 | or else Is_Constant_Object (Ent)) |
9dfe12ae | 4350 | and then not Is_Library_Level_Entity (Ent) |
4351 | then | |
4352 | Entry_OK := True; | |
4353 | else | |
4354 | Entry_OK := False; | |
4355 | return; | |
4356 | end if; | |
4357 | ||
4358 | -- See if there is matching check already | |
4359 | ||
4360 | for J in reverse 1 .. Num_Saved_Checks loop | |
4361 | declare | |
4362 | SC : Saved_Check renames Saved_Checks (J); | |
4363 | ||
4364 | begin | |
4365 | if SC.Killed = False | |
4366 | and then SC.Entity = Ent | |
4367 | and then SC.Offset = Ofs | |
4368 | and then SC.Check_Type = Check_Type | |
4369 | and then Within_Range_Of (Target_Type, SC.Target_Type) | |
4370 | then | |
4371 | Check_Num := J; | |
4372 | return; | |
4373 | end if; | |
4374 | end; | |
4375 | end loop; | |
4376 | ||
4377 | -- If we fall through entry was not found | |
4378 | ||
4379 | Check_Num := 0; | |
4380 | return; | |
4381 | end Find_Check; | |
4382 | ||
4383 | --------------------------------- | |
4384 | -- Generate_Discriminant_Check -- | |
4385 | --------------------------------- | |
4386 | ||
4387 | -- Note: the code for this procedure is derived from the | |
feff2f05 | 4388 | -- Emit_Discriminant_Check Routine in trans.c. |
9dfe12ae | 4389 | |
4390 | procedure Generate_Discriminant_Check (N : Node_Id) is | |
4391 | Loc : constant Source_Ptr := Sloc (N); | |
4392 | Pref : constant Node_Id := Prefix (N); | |
4393 | Sel : constant Node_Id := Selector_Name (N); | |
4394 | ||
4395 | Orig_Comp : constant Entity_Id := | |
4396 | Original_Record_Component (Entity (Sel)); | |
4397 | -- The original component to be checked | |
4398 | ||
4399 | Discr_Fct : constant Entity_Id := | |
4400 | Discriminant_Checking_Func (Orig_Comp); | |
4401 | -- The discriminant checking function | |
4402 | ||
4403 | Discr : Entity_Id; | |
4404 | -- One discriminant to be checked in the type | |
4405 | ||
4406 | Real_Discr : Entity_Id; | |
4407 | -- Actual discriminant in the call | |
4408 | ||
4409 | Pref_Type : Entity_Id; | |
4410 | -- Type of relevant prefix (ignoring private/access stuff) | |
4411 | ||
4412 | Args : List_Id; | |
4413 | -- List of arguments for function call | |
4414 | ||
4415 | Formal : Entity_Id; | |
feff2f05 | 4416 | -- Keep track of the formal corresponding to the actual we build for |
4417 | -- each discriminant, in order to be able to perform the necessary type | |
4418 | -- conversions. | |
9dfe12ae | 4419 | |
4420 | Scomp : Node_Id; | |
4421 | -- Selected component reference for checking function argument | |
4422 | ||
4423 | begin | |
4424 | Pref_Type := Etype (Pref); | |
4425 | ||
4426 | -- Force evaluation of the prefix, so that it does not get evaluated | |
4427 | -- twice (once for the check, once for the actual reference). Such a | |
4428 | -- double evaluation is always a potential source of inefficiency, | |
4429 | -- and is functionally incorrect in the volatile case, or when the | |
4430 | -- prefix may have side-effects. An entity or a component of an | |
4431 | -- entity requires no evaluation. | |
4432 | ||
4433 | if Is_Entity_Name (Pref) then | |
4434 | if Treat_As_Volatile (Entity (Pref)) then | |
4435 | Force_Evaluation (Pref, Name_Req => True); | |
4436 | end if; | |
4437 | ||
4438 | elsif Treat_As_Volatile (Etype (Pref)) then | |
4439 | Force_Evaluation (Pref, Name_Req => True); | |
4440 | ||
4441 | elsif Nkind (Pref) = N_Selected_Component | |
4442 | and then Is_Entity_Name (Prefix (Pref)) | |
4443 | then | |
4444 | null; | |
4445 | ||
4446 | else | |
4447 | Force_Evaluation (Pref, Name_Req => True); | |
4448 | end if; | |
4449 | ||
4450 | -- For a tagged type, use the scope of the original component to | |
4451 | -- obtain the type, because ??? | |
4452 | ||
4453 | if Is_Tagged_Type (Scope (Orig_Comp)) then | |
4454 | Pref_Type := Scope (Orig_Comp); | |
4455 | ||
feff2f05 | 4456 | -- For an untagged derived type, use the discriminants of the parent |
4457 | -- which have been renamed in the derivation, possibly by a one-to-many | |
4458 | -- discriminant constraint. For non-tagged type, initially get the Etype | |
4459 | -- of the prefix | |
9dfe12ae | 4460 | |
4461 | else | |
4462 | if Is_Derived_Type (Pref_Type) | |
4463 | and then Number_Discriminants (Pref_Type) /= | |
4464 | Number_Discriminants (Etype (Base_Type (Pref_Type))) | |
4465 | then | |
4466 | Pref_Type := Etype (Base_Type (Pref_Type)); | |
4467 | end if; | |
4468 | end if; | |
4469 | ||
4470 | -- We definitely should have a checking function, This routine should | |
4471 | -- not be called if no discriminant checking function is present. | |
4472 | ||
4473 | pragma Assert (Present (Discr_Fct)); | |
4474 | ||
4475 | -- Create the list of the actual parameters for the call. This list | |
4476 | -- is the list of the discriminant fields of the record expression to | |
4477 | -- be discriminant checked. | |
4478 | ||
4479 | Args := New_List; | |
4480 | Formal := First_Formal (Discr_Fct); | |
4481 | Discr := First_Discriminant (Pref_Type); | |
4482 | while Present (Discr) loop | |
4483 | ||
4484 | -- If we have a corresponding discriminant field, and a parent | |
4485 | -- subtype is present, then we want to use the corresponding | |
4486 | -- discriminant since this is the one with the useful value. | |
4487 | ||
4488 | if Present (Corresponding_Discriminant (Discr)) | |
4489 | and then Ekind (Pref_Type) = E_Record_Type | |
4490 | and then Present (Parent_Subtype (Pref_Type)) | |
4491 | then | |
4492 | Real_Discr := Corresponding_Discriminant (Discr); | |
4493 | else | |
4494 | Real_Discr := Discr; | |
4495 | end if; | |
4496 | ||
4497 | -- Construct the reference to the discriminant | |
4498 | ||
4499 | Scomp := | |
4500 | Make_Selected_Component (Loc, | |
4501 | Prefix => | |
4502 | Unchecked_Convert_To (Pref_Type, | |
4503 | Duplicate_Subexpr (Pref)), | |
4504 | Selector_Name => New_Occurrence_Of (Real_Discr, Loc)); | |
4505 | ||
4506 | -- Manually analyze and resolve this selected component. We really | |
4507 | -- want it just as it appears above, and do not want the expander | |
feff2f05 | 4508 | -- playing discriminal games etc with this reference. Then we append |
4509 | -- the argument to the list we are gathering. | |
9dfe12ae | 4510 | |
4511 | Set_Etype (Scomp, Etype (Real_Discr)); | |
4512 | Set_Analyzed (Scomp, True); | |
4513 | Append_To (Args, Convert_To (Etype (Formal), Scomp)); | |
4514 | ||
4515 | Next_Formal_With_Extras (Formal); | |
4516 | Next_Discriminant (Discr); | |
4517 | end loop; | |
4518 | ||
4519 | -- Now build and insert the call | |
4520 | ||
4521 | Insert_Action (N, | |
4522 | Make_Raise_Constraint_Error (Loc, | |
4523 | Condition => | |
4524 | Make_Function_Call (Loc, | |
4525 | Name => New_Occurrence_Of (Discr_Fct, Loc), | |
4526 | Parameter_Associations => Args), | |
4527 | Reason => CE_Discriminant_Check_Failed)); | |
4528 | end Generate_Discriminant_Check; | |
4529 | ||
5c99c290 | 4530 | --------------------------- |
4531 | -- Generate_Index_Checks -- | |
4532 | --------------------------- | |
9dfe12ae | 4533 | |
4534 | procedure Generate_Index_Checks (N : Node_Id) is | |
4535 | Loc : constant Source_Ptr := Sloc (N); | |
4536 | A : constant Node_Id := Prefix (N); | |
4537 | Sub : Node_Id; | |
4538 | Ind : Nat; | |
4539 | Num : List_Id; | |
4540 | ||
4541 | begin | |
0577b0b1 | 4542 | -- Ignore call if index checks suppressed for array object or type |
4543 | ||
4544 | if (Is_Entity_Name (A) and then Index_Checks_Suppressed (Entity (A))) | |
4545 | or else Index_Checks_Suppressed (Etype (A)) | |
4546 | then | |
4547 | return; | |
4548 | end if; | |
4549 | ||
4550 | -- Generate the checks | |
4551 | ||
9dfe12ae | 4552 | Sub := First (Expressions (N)); |
4553 | Ind := 1; | |
4554 | while Present (Sub) loop | |
4555 | if Do_Range_Check (Sub) then | |
4556 | Set_Do_Range_Check (Sub, False); | |
4557 | ||
feff2f05 | 4558 | -- Force evaluation except for the case of a simple name of a |
4559 | -- non-volatile entity. | |
9dfe12ae | 4560 | |
4561 | if not Is_Entity_Name (Sub) | |
4562 | or else Treat_As_Volatile (Entity (Sub)) | |
4563 | then | |
4564 | Force_Evaluation (Sub); | |
4565 | end if; | |
4566 | ||
4567 | -- Generate a raise of constraint error with the appropriate | |
4568 | -- reason and a condition of the form: | |
4569 | ||
4570 | -- Base_Type(Sub) not in array'range (subscript) | |
4571 | ||
feff2f05 | 4572 | -- Note that the reason we generate the conversion to the base |
4573 | -- type here is that we definitely want the range check to take | |
4574 | -- place, even if it looks like the subtype is OK. Optimization | |
4575 | -- considerations that allow us to omit the check have already | |
4576 | -- been taken into account in the setting of the Do_Range_Check | |
4577 | -- flag earlier on. | |
9dfe12ae | 4578 | |
4579 | if Ind = 1 then | |
4580 | Num := No_List; | |
4581 | else | |
4582 | Num := New_List (Make_Integer_Literal (Loc, Ind)); | |
4583 | end if; | |
4584 | ||
4585 | Insert_Action (N, | |
4586 | Make_Raise_Constraint_Error (Loc, | |
4587 | Condition => | |
4588 | Make_Not_In (Loc, | |
4589 | Left_Opnd => | |
4590 | Convert_To (Base_Type (Etype (Sub)), | |
4591 | Duplicate_Subexpr_Move_Checks (Sub)), | |
4592 | Right_Opnd => | |
4593 | Make_Attribute_Reference (Loc, | |
cc60bd16 | 4594 | Prefix => |
4595 | Duplicate_Subexpr_Move_Checks (A, Name_Req => True), | |
9dfe12ae | 4596 | Attribute_Name => Name_Range, |
4597 | Expressions => Num)), | |
4598 | Reason => CE_Index_Check_Failed)); | |
4599 | end if; | |
4600 | ||
4601 | Ind := Ind + 1; | |
4602 | Next (Sub); | |
4603 | end loop; | |
4604 | end Generate_Index_Checks; | |
4605 | ||
4606 | -------------------------- | |
4607 | -- Generate_Range_Check -- | |
4608 | -------------------------- | |
4609 | ||
4610 | procedure Generate_Range_Check | |
4611 | (N : Node_Id; | |
4612 | Target_Type : Entity_Id; | |
4613 | Reason : RT_Exception_Code) | |
4614 | is | |
4615 | Loc : constant Source_Ptr := Sloc (N); | |
4616 | Source_Type : constant Entity_Id := Etype (N); | |
4617 | Source_Base_Type : constant Entity_Id := Base_Type (Source_Type); | |
4618 | Target_Base_Type : constant Entity_Id := Base_Type (Target_Type); | |
4619 | ||
4620 | begin | |
feff2f05 | 4621 | -- First special case, if the source type is already within the range |
4622 | -- of the target type, then no check is needed (probably we should have | |
4623 | -- stopped Do_Range_Check from being set in the first place, but better | |
4624 | -- late than later in preventing junk code! | |
9dfe12ae | 4625 | |
feff2f05 | 4626 | -- We do NOT apply this if the source node is a literal, since in this |
4627 | -- case the literal has already been labeled as having the subtype of | |
4628 | -- the target. | |
9dfe12ae | 4629 | |
7a1dabb3 | 4630 | if In_Subrange_Of (Source_Type, Target_Type) |
9dfe12ae | 4631 | and then not |
4632 | (Nkind (N) = N_Integer_Literal | |
4633 | or else | |
4634 | Nkind (N) = N_Real_Literal | |
4635 | or else | |
4636 | Nkind (N) = N_Character_Literal | |
4637 | or else | |
4638 | (Is_Entity_Name (N) | |
4639 | and then Ekind (Entity (N)) = E_Enumeration_Literal)) | |
4640 | then | |
4641 | return; | |
4642 | end if; | |
4643 | ||
4644 | -- We need a check, so force evaluation of the node, so that it does | |
4645 | -- not get evaluated twice (once for the check, once for the actual | |
4646 | -- reference). Such a double evaluation is always a potential source | |
4647 | -- of inefficiency, and is functionally incorrect in the volatile case. | |
4648 | ||
4649 | if not Is_Entity_Name (N) | |
4650 | or else Treat_As_Volatile (Entity (N)) | |
4651 | then | |
4652 | Force_Evaluation (N); | |
4653 | end if; | |
4654 | ||
feff2f05 | 4655 | -- The easiest case is when Source_Base_Type and Target_Base_Type are |
4656 | -- the same since in this case we can simply do a direct check of the | |
4657 | -- value of N against the bounds of Target_Type. | |
9dfe12ae | 4658 | |
4659 | -- [constraint_error when N not in Target_Type] | |
4660 | ||
4661 | -- Note: this is by far the most common case, for example all cases of | |
4662 | -- checks on the RHS of assignments are in this category, but not all | |
4663 | -- cases are like this. Notably conversions can involve two types. | |
4664 | ||
4665 | if Source_Base_Type = Target_Base_Type then | |
4666 | Insert_Action (N, | |
4667 | Make_Raise_Constraint_Error (Loc, | |
4668 | Condition => | |
4669 | Make_Not_In (Loc, | |
4670 | Left_Opnd => Duplicate_Subexpr (N), | |
4671 | Right_Opnd => New_Occurrence_Of (Target_Type, Loc)), | |
4672 | Reason => Reason)); | |
4673 | ||
4674 | -- Next test for the case where the target type is within the bounds | |
4675 | -- of the base type of the source type, since in this case we can | |
4676 | -- simply convert these bounds to the base type of T to do the test. | |
4677 | ||
4678 | -- [constraint_error when N not in | |
4679 | -- Source_Base_Type (Target_Type'First) | |
4680 | -- .. | |
4681 | -- Source_Base_Type(Target_Type'Last))] | |
4682 | ||
f2a06be9 | 4683 | -- The conversions will always work and need no check |
9dfe12ae | 4684 | |
a9b57347 | 4685 | -- Unchecked_Convert_To is used instead of Convert_To to handle the case |
4686 | -- of converting from an enumeration value to an integer type, such as | |
4687 | -- occurs for the case of generating a range check on Enum'Val(Exp) | |
4688 | -- (which used to be handled by gigi). This is OK, since the conversion | |
4689 | -- itself does not require a check. | |
4690 | ||
7a1dabb3 | 4691 | elsif In_Subrange_Of (Target_Type, Source_Base_Type) then |
9dfe12ae | 4692 | Insert_Action (N, |
4693 | Make_Raise_Constraint_Error (Loc, | |
4694 | Condition => | |
4695 | Make_Not_In (Loc, | |
4696 | Left_Opnd => Duplicate_Subexpr (N), | |
4697 | ||
4698 | Right_Opnd => | |
4699 | Make_Range (Loc, | |
4700 | Low_Bound => | |
a9b57347 | 4701 | Unchecked_Convert_To (Source_Base_Type, |
9dfe12ae | 4702 | Make_Attribute_Reference (Loc, |
4703 | Prefix => | |
4704 | New_Occurrence_Of (Target_Type, Loc), | |
4705 | Attribute_Name => Name_First)), | |
4706 | ||
4707 | High_Bound => | |
a9b57347 | 4708 | Unchecked_Convert_To (Source_Base_Type, |
9dfe12ae | 4709 | Make_Attribute_Reference (Loc, |
4710 | Prefix => | |
4711 | New_Occurrence_Of (Target_Type, Loc), | |
4712 | Attribute_Name => Name_Last)))), | |
4713 | Reason => Reason)); | |
4714 | ||
feff2f05 | 4715 | -- Note that at this stage we now that the Target_Base_Type is not in |
4716 | -- the range of the Source_Base_Type (since even the Target_Type itself | |
4717 | -- is not in this range). It could still be the case that Source_Type is | |
4718 | -- in range of the target base type since we have not checked that case. | |
9dfe12ae | 4719 | |
feff2f05 | 4720 | -- If that is the case, we can freely convert the source to the target, |
4721 | -- and then test the target result against the bounds. | |
9dfe12ae | 4722 | |
7a1dabb3 | 4723 | elsif In_Subrange_Of (Source_Type, Target_Base_Type) then |
9dfe12ae | 4724 | |
feff2f05 | 4725 | -- We make a temporary to hold the value of the converted value |
4726 | -- (converted to the base type), and then we will do the test against | |
4727 | -- this temporary. | |
9dfe12ae | 4728 | |
4729 | -- Tnn : constant Target_Base_Type := Target_Base_Type (N); | |
4730 | -- [constraint_error when Tnn not in Target_Type] | |
4731 | ||
4732 | -- Then the conversion itself is replaced by an occurrence of Tnn | |
4733 | ||
4734 | declare | |
4735 | Tnn : constant Entity_Id := | |
4736 | Make_Defining_Identifier (Loc, | |
4737 | Chars => New_Internal_Name ('T')); | |
4738 | ||
4739 | begin | |
4740 | Insert_Actions (N, New_List ( | |
4741 | Make_Object_Declaration (Loc, | |
4742 | Defining_Identifier => Tnn, | |
4743 | Object_Definition => | |
4744 | New_Occurrence_Of (Target_Base_Type, Loc), | |
4745 | Constant_Present => True, | |
4746 | Expression => | |
4747 | Make_Type_Conversion (Loc, | |
4748 | Subtype_Mark => New_Occurrence_Of (Target_Base_Type, Loc), | |
4749 | Expression => Duplicate_Subexpr (N))), | |
4750 | ||
4751 | Make_Raise_Constraint_Error (Loc, | |
4752 | Condition => | |
4753 | Make_Not_In (Loc, | |
4754 | Left_Opnd => New_Occurrence_Of (Tnn, Loc), | |
4755 | Right_Opnd => New_Occurrence_Of (Target_Type, Loc)), | |
4756 | ||
4757 | Reason => Reason))); | |
4758 | ||
4759 | Rewrite (N, New_Occurrence_Of (Tnn, Loc)); | |
2af58f67 | 4760 | |
4761 | -- Set the type of N, because the declaration for Tnn might not | |
4762 | -- be analyzed yet, as is the case if N appears within a record | |
4763 | -- declaration, as a discriminant constraint or expression. | |
4764 | ||
4765 | Set_Etype (N, Target_Base_Type); | |
9dfe12ae | 4766 | end; |
4767 | ||
4768 | -- At this stage, we know that we have two scalar types, which are | |
4769 | -- directly convertible, and where neither scalar type has a base | |
4770 | -- range that is in the range of the other scalar type. | |
4771 | ||
4772 | -- The only way this can happen is with a signed and unsigned type. | |
4773 | -- So test for these two cases: | |
4774 | ||
4775 | else | |
4776 | -- Case of the source is unsigned and the target is signed | |
4777 | ||
4778 | if Is_Unsigned_Type (Source_Base_Type) | |
4779 | and then not Is_Unsigned_Type (Target_Base_Type) | |
4780 | then | |
4781 | -- If the source is unsigned and the target is signed, then we | |
4782 | -- know that the source is not shorter than the target (otherwise | |
4783 | -- the source base type would be in the target base type range). | |
4784 | ||
feff2f05 | 4785 | -- In other words, the unsigned type is either the same size as |
4786 | -- the target, or it is larger. It cannot be smaller. | |
9dfe12ae | 4787 | |
4788 | pragma Assert | |
4789 | (Esize (Source_Base_Type) >= Esize (Target_Base_Type)); | |
4790 | ||
4791 | -- We only need to check the low bound if the low bound of the | |
4792 | -- target type is non-negative. If the low bound of the target | |
4793 | -- type is negative, then we know that we will fit fine. | |
4794 | ||
4795 | -- If the high bound of the target type is negative, then we | |
4796 | -- know we have a constraint error, since we can't possibly | |
4797 | -- have a negative source. | |
4798 | ||
4799 | -- With these two checks out of the way, we can do the check | |
4800 | -- using the source type safely | |
4801 | ||
4802 | -- This is definitely the most annoying case! | |
4803 | ||
4804 | -- [constraint_error | |
4805 | -- when (Target_Type'First >= 0 | |
4806 | -- and then | |
4807 | -- N < Source_Base_Type (Target_Type'First)) | |
4808 | -- or else Target_Type'Last < 0 | |
4809 | -- or else N > Source_Base_Type (Target_Type'Last)]; | |
4810 | ||
4811 | -- We turn off all checks since we know that the conversions | |
4812 | -- will work fine, given the guards for negative values. | |
4813 | ||
4814 | Insert_Action (N, | |
4815 | Make_Raise_Constraint_Error (Loc, | |
4816 | Condition => | |
4817 | Make_Or_Else (Loc, | |
4818 | Make_Or_Else (Loc, | |
4819 | Left_Opnd => | |
4820 | Make_And_Then (Loc, | |
4821 | Left_Opnd => Make_Op_Ge (Loc, | |
4822 | Left_Opnd => | |
4823 | Make_Attribute_Reference (Loc, | |
4824 | Prefix => | |
4825 | New_Occurrence_Of (Target_Type, Loc), | |
4826 | Attribute_Name => Name_First), | |
4827 | Right_Opnd => Make_Integer_Literal (Loc, Uint_0)), | |
4828 | ||
4829 | Right_Opnd => | |
4830 | Make_Op_Lt (Loc, | |
4831 | Left_Opnd => Duplicate_Subexpr (N), | |
4832 | Right_Opnd => | |
4833 | Convert_To (Source_Base_Type, | |
4834 | Make_Attribute_Reference (Loc, | |
4835 | Prefix => | |
4836 | New_Occurrence_Of (Target_Type, Loc), | |
4837 | Attribute_Name => Name_First)))), | |
4838 | ||
4839 | Right_Opnd => | |
4840 | Make_Op_Lt (Loc, | |
4841 | Left_Opnd => | |
4842 | Make_Attribute_Reference (Loc, | |
4843 | Prefix => New_Occurrence_Of (Target_Type, Loc), | |
4844 | Attribute_Name => Name_Last), | |
4845 | Right_Opnd => Make_Integer_Literal (Loc, Uint_0))), | |
4846 | ||
4847 | Right_Opnd => | |
4848 | Make_Op_Gt (Loc, | |
4849 | Left_Opnd => Duplicate_Subexpr (N), | |
4850 | Right_Opnd => | |
4851 | Convert_To (Source_Base_Type, | |
4852 | Make_Attribute_Reference (Loc, | |
4853 | Prefix => New_Occurrence_Of (Target_Type, Loc), | |
4854 | Attribute_Name => Name_Last)))), | |
4855 | ||
4856 | Reason => Reason), | |
4857 | Suppress => All_Checks); | |
4858 | ||
4859 | -- Only remaining possibility is that the source is signed and | |
fc75802a | 4860 | -- the target is unsigned. |
9dfe12ae | 4861 | |
4862 | else | |
4863 | pragma Assert (not Is_Unsigned_Type (Source_Base_Type) | |
4864 | and then Is_Unsigned_Type (Target_Base_Type)); | |
4865 | ||
feff2f05 | 4866 | -- If the source is signed and the target is unsigned, then we |
4867 | -- know that the target is not shorter than the source (otherwise | |
4868 | -- the target base type would be in the source base type range). | |
9dfe12ae | 4869 | |
feff2f05 | 4870 | -- In other words, the unsigned type is either the same size as |
4871 | -- the target, or it is larger. It cannot be smaller. | |
9dfe12ae | 4872 | |
feff2f05 | 4873 | -- Clearly we have an error if the source value is negative since |
4874 | -- no unsigned type can have negative values. If the source type | |
4875 | -- is non-negative, then the check can be done using the target | |
4876 | -- type. | |
9dfe12ae | 4877 | |
4878 | -- Tnn : constant Target_Base_Type (N) := Target_Type; | |
4879 | ||
4880 | -- [constraint_error | |
4881 | -- when N < 0 or else Tnn not in Target_Type]; | |
4882 | ||
feff2f05 | 4883 | -- We turn off all checks for the conversion of N to the target |
4884 | -- base type, since we generate the explicit check to ensure that | |
4885 | -- the value is non-negative | |
9dfe12ae | 4886 | |
4887 | declare | |
4888 | Tnn : constant Entity_Id := | |
4889 | Make_Defining_Identifier (Loc, | |
4890 | Chars => New_Internal_Name ('T')); | |
4891 | ||
4892 | begin | |
4893 | Insert_Actions (N, New_List ( | |
4894 | Make_Object_Declaration (Loc, | |
4895 | Defining_Identifier => Tnn, | |
4896 | Object_Definition => | |
4897 | New_Occurrence_Of (Target_Base_Type, Loc), | |
4898 | Constant_Present => True, | |
4899 | Expression => | |
a9b57347 | 4900 | Make_Unchecked_Type_Conversion (Loc, |
9dfe12ae | 4901 | Subtype_Mark => |
4902 | New_Occurrence_Of (Target_Base_Type, Loc), | |
4903 | Expression => Duplicate_Subexpr (N))), | |
4904 | ||
4905 | Make_Raise_Constraint_Error (Loc, | |
4906 | Condition => | |
4907 | Make_Or_Else (Loc, | |
4908 | Left_Opnd => | |
4909 | Make_Op_Lt (Loc, | |
4910 | Left_Opnd => Duplicate_Subexpr (N), | |
4911 | Right_Opnd => Make_Integer_Literal (Loc, Uint_0)), | |
4912 | ||
4913 | Right_Opnd => | |
4914 | Make_Not_In (Loc, | |
4915 | Left_Opnd => New_Occurrence_Of (Tnn, Loc), | |
4916 | Right_Opnd => | |
4917 | New_Occurrence_Of (Target_Type, Loc))), | |
4918 | ||
4919 | Reason => Reason)), | |
4920 | Suppress => All_Checks); | |
4921 | ||
feff2f05 | 4922 | -- Set the Etype explicitly, because Insert_Actions may have |
4923 | -- placed the declaration in the freeze list for an enclosing | |
4924 | -- construct, and thus it is not analyzed yet. | |
9dfe12ae | 4925 | |
4926 | Set_Etype (Tnn, Target_Base_Type); | |
4927 | Rewrite (N, New_Occurrence_Of (Tnn, Loc)); | |
4928 | end; | |
4929 | end if; | |
4930 | end if; | |
4931 | end Generate_Range_Check; | |
4932 | ||
2af58f67 | 4933 | ------------------ |
4934 | -- Get_Check_Id -- | |
4935 | ------------------ | |
4936 | ||
4937 | function Get_Check_Id (N : Name_Id) return Check_Id is | |
4938 | begin | |
4939 | -- For standard check name, we can do a direct computation | |
4940 | ||
4941 | if N in First_Check_Name .. Last_Check_Name then | |
4942 | return Check_Id (N - (First_Check_Name - 1)); | |
4943 | ||
4944 | -- For non-standard names added by pragma Check_Name, search table | |
4945 | ||
4946 | else | |
4947 | for J in All_Checks + 1 .. Check_Names.Last loop | |
4948 | if Check_Names.Table (J) = N then | |
4949 | return J; | |
4950 | end if; | |
4951 | end loop; | |
4952 | end if; | |
4953 | ||
4954 | -- No matching name found | |
4955 | ||
4956 | return No_Check_Id; | |
4957 | end Get_Check_Id; | |
4958 | ||
ee6ba406 | 4959 | --------------------- |
4960 | -- Get_Discriminal -- | |
4961 | --------------------- | |
4962 | ||
4963 | function Get_Discriminal (E : Entity_Id; Bound : Node_Id) return Node_Id is | |
4964 | Loc : constant Source_Ptr := Sloc (E); | |
4965 | D : Entity_Id; | |
4966 | Sc : Entity_Id; | |
4967 | ||
4968 | begin | |
0577b0b1 | 4969 | -- The bound can be a bona fide parameter of a protected operation, |
4970 | -- rather than a prival encoded as an in-parameter. | |
4971 | ||
4972 | if No (Discriminal_Link (Entity (Bound))) then | |
4973 | return Bound; | |
4974 | end if; | |
4975 | ||
2af58f67 | 4976 | -- Climb the scope stack looking for an enclosing protected type. If |
4977 | -- we run out of scopes, return the bound itself. | |
4978 | ||
4979 | Sc := Scope (E); | |
4980 | while Present (Sc) loop | |
4981 | if Sc = Standard_Standard then | |
4982 | return Bound; | |
4983 | ||
4984 | elsif Ekind (Sc) = E_Protected_Type then | |
4985 | exit; | |
4986 | end if; | |
4987 | ||
4988 | Sc := Scope (Sc); | |
4989 | end loop; | |
4990 | ||
ee6ba406 | 4991 | D := First_Discriminant (Sc); |
2af58f67 | 4992 | while Present (D) loop |
4993 | if Chars (D) = Chars (Bound) then | |
4994 | return New_Occurrence_Of (Discriminal (D), Loc); | |
4995 | end if; | |
ee6ba406 | 4996 | |
ee6ba406 | 4997 | Next_Discriminant (D); |
4998 | end loop; | |
4999 | ||
2af58f67 | 5000 | return Bound; |
ee6ba406 | 5001 | end Get_Discriminal; |
5002 | ||
2af58f67 | 5003 | ---------------------- |
5004 | -- Get_Range_Checks -- | |
5005 | ---------------------- | |
5006 | ||
5007 | function Get_Range_Checks | |
5008 | (Ck_Node : Node_Id; | |
5009 | Target_Typ : Entity_Id; | |
5010 | Source_Typ : Entity_Id := Empty; | |
5011 | Warn_Node : Node_Id := Empty) return Check_Result | |
5012 | is | |
5013 | begin | |
5014 | return Selected_Range_Checks | |
5015 | (Ck_Node, Target_Typ, Source_Typ, Warn_Node); | |
5016 | end Get_Range_Checks; | |
5017 | ||
ee6ba406 | 5018 | ------------------ |
5019 | -- Guard_Access -- | |
5020 | ------------------ | |
5021 | ||
5022 | function Guard_Access | |
5023 | (Cond : Node_Id; | |
5024 | Loc : Source_Ptr; | |
314a23b6 | 5025 | Ck_Node : Node_Id) return Node_Id |
ee6ba406 | 5026 | is |
5027 | begin | |
5028 | if Nkind (Cond) = N_Or_Else then | |
5029 | Set_Paren_Count (Cond, 1); | |
5030 | end if; | |
5031 | ||
5032 | if Nkind (Ck_Node) = N_Allocator then | |
5033 | return Cond; | |
5034 | else | |
5035 | return | |
5036 | Make_And_Then (Loc, | |
5037 | Left_Opnd => | |
5038 | Make_Op_Ne (Loc, | |
9dfe12ae | 5039 | Left_Opnd => Duplicate_Subexpr_No_Checks (Ck_Node), |
ee6ba406 | 5040 | Right_Opnd => Make_Null (Loc)), |
5041 | Right_Opnd => Cond); | |
5042 | end if; | |
5043 | end Guard_Access; | |
5044 | ||
5045 | ----------------------------- | |
5046 | -- Index_Checks_Suppressed -- | |
5047 | ----------------------------- | |
5048 | ||
5049 | function Index_Checks_Suppressed (E : Entity_Id) return Boolean is | |
5050 | begin | |
9dfe12ae | 5051 | if Present (E) and then Checks_May_Be_Suppressed (E) then |
5052 | return Is_Check_Suppressed (E, Index_Check); | |
5053 | else | |
5054 | return Scope_Suppress (Index_Check); | |
5055 | end if; | |
ee6ba406 | 5056 | end Index_Checks_Suppressed; |
5057 | ||
5058 | ---------------- | |
5059 | -- Initialize -- | |
5060 | ---------------- | |
5061 | ||
5062 | procedure Initialize is | |
5063 | begin | |
5064 | for J in Determine_Range_Cache_N'Range loop | |
5065 | Determine_Range_Cache_N (J) := Empty; | |
5066 | end loop; | |
2af58f67 | 5067 | |
5068 | Check_Names.Init; | |
5069 | ||
5070 | for J in Int range 1 .. All_Checks loop | |
5071 | Check_Names.Append (Name_Id (Int (First_Check_Name) + J - 1)); | |
5072 | end loop; | |
ee6ba406 | 5073 | end Initialize; |
5074 | ||
5075 | ------------------------- | |
5076 | -- Insert_Range_Checks -- | |
5077 | ------------------------- | |
5078 | ||
5079 | procedure Insert_Range_Checks | |
5080 | (Checks : Check_Result; | |
5081 | Node : Node_Id; | |
5082 | Suppress_Typ : Entity_Id; | |
5083 | Static_Sloc : Source_Ptr := No_Location; | |
5084 | Flag_Node : Node_Id := Empty; | |
5085 | Do_Before : Boolean := False) | |
5086 | is | |
5087 | Internal_Flag_Node : Node_Id := Flag_Node; | |
5088 | Internal_Static_Sloc : Source_Ptr := Static_Sloc; | |
5089 | ||
5090 | Check_Node : Node_Id; | |
5091 | Checks_On : constant Boolean := | |
5092 | (not Index_Checks_Suppressed (Suppress_Typ)) | |
5093 | or else | |
5094 | (not Range_Checks_Suppressed (Suppress_Typ)); | |
5095 | ||
5096 | begin | |
feff2f05 | 5097 | -- For now we just return if Checks_On is false, however this should be |
5098 | -- enhanced to check for an always True value in the condition and to | |
5099 | -- generate a compilation warning??? | |
ee6ba406 | 5100 | |
5101 | if not Expander_Active or else not Checks_On then | |
5102 | return; | |
5103 | end if; | |
5104 | ||
5105 | if Static_Sloc = No_Location then | |
5106 | Internal_Static_Sloc := Sloc (Node); | |
5107 | end if; | |
5108 | ||
5109 | if No (Flag_Node) then | |
5110 | Internal_Flag_Node := Node; | |
5111 | end if; | |
5112 | ||
5113 | for J in 1 .. 2 loop | |
5114 | exit when No (Checks (J)); | |
5115 | ||
5116 | if Nkind (Checks (J)) = N_Raise_Constraint_Error | |
5117 | and then Present (Condition (Checks (J))) | |
5118 | then | |
5119 | if not Has_Dynamic_Range_Check (Internal_Flag_Node) then | |
5120 | Check_Node := Checks (J); | |
5121 | Mark_Rewrite_Insertion (Check_Node); | |
5122 | ||
5123 | if Do_Before then | |
5124 | Insert_Before_And_Analyze (Node, Check_Node); | |
5125 | else | |
5126 | Insert_After_And_Analyze (Node, Check_Node); | |
5127 | end if; | |
5128 | ||
5129 | Set_Has_Dynamic_Range_Check (Internal_Flag_Node); | |
5130 | end if; | |
5131 | ||
5132 | else | |
5133 | Check_Node := | |
f15731c4 | 5134 | Make_Raise_Constraint_Error (Internal_Static_Sloc, |
5135 | Reason => CE_Range_Check_Failed); | |
ee6ba406 | 5136 | Mark_Rewrite_Insertion (Check_Node); |
5137 | ||
5138 | if Do_Before then | |
5139 | Insert_Before_And_Analyze (Node, Check_Node); | |
5140 | else | |
5141 | Insert_After_And_Analyze (Node, Check_Node); | |
5142 | end if; | |
5143 | end if; | |
5144 | end loop; | |
5145 | end Insert_Range_Checks; | |
5146 | ||
5147 | ------------------------ | |
5148 | -- Insert_Valid_Check -- | |
5149 | ------------------------ | |
5150 | ||
5151 | procedure Insert_Valid_Check (Expr : Node_Id) is | |
5152 | Loc : constant Source_Ptr := Sloc (Expr); | |
8b718dab | 5153 | Exp : Node_Id; |
ee6ba406 | 5154 | |
5155 | begin | |
06ad5813 | 5156 | -- Do not insert if checks off, or if not checking validity or |
5157 | -- if expression is known to be valid | |
ee6ba406 | 5158 | |
0577b0b1 | 5159 | if not Validity_Checks_On |
5160 | or else Range_Or_Validity_Checks_Suppressed (Expr) | |
06ad5813 | 5161 | or else Expr_Known_Valid (Expr) |
ee6ba406 | 5162 | then |
8b718dab | 5163 | return; |
5164 | end if; | |
ee6ba406 | 5165 | |
8b718dab | 5166 | -- If we have a checked conversion, then validity check applies to |
5167 | -- the expression inside the conversion, not the result, since if | |
5168 | -- the expression inside is valid, then so is the conversion result. | |
ee6ba406 | 5169 | |
8b718dab | 5170 | Exp := Expr; |
5171 | while Nkind (Exp) = N_Type_Conversion loop | |
5172 | Exp := Expression (Exp); | |
5173 | end loop; | |
5174 | ||
0577b0b1 | 5175 | -- We are about to insert the validity check for Exp. We save and |
5176 | -- reset the Do_Range_Check flag over this validity check, and then | |
5177 | -- put it back for the final original reference (Exp may be rewritten). | |
5178 | ||
5179 | declare | |
5180 | DRC : constant Boolean := Do_Range_Check (Exp); | |
05fcfafb | 5181 | |
0577b0b1 | 5182 | begin |
5183 | Set_Do_Range_Check (Exp, False); | |
5184 | ||
06ad5813 | 5185 | -- Force evaluation to avoid multiple reads for atomic/volatile |
5186 | ||
5187 | if Is_Entity_Name (Exp) | |
5188 | and then Is_Volatile (Entity (Exp)) | |
5189 | then | |
5190 | Force_Evaluation (Exp, Name_Req => True); | |
5191 | end if; | |
5192 | ||
0577b0b1 | 5193 | -- Insert the validity check. Note that we do this with validity |
5194 | -- checks turned off, to avoid recursion, we do not want validity | |
5195 | -- checks on the validity checking code itself! | |
5196 | ||
5197 | Insert_Action | |
5198 | (Expr, | |
5199 | Make_Raise_Constraint_Error (Loc, | |
5200 | Condition => | |
5201 | Make_Op_Not (Loc, | |
5202 | Right_Opnd => | |
5203 | Make_Attribute_Reference (Loc, | |
5204 | Prefix => | |
5205 | Duplicate_Subexpr_No_Checks (Exp, Name_Req => True), | |
5206 | Attribute_Name => Name_Valid)), | |
5207 | Reason => CE_Invalid_Data), | |
5208 | Suppress => Validity_Check); | |
5209 | ||
5210 | -- If the expression is a a reference to an element of a bit-packed | |
5211 | -- array, then it is rewritten as a renaming declaration. If the | |
5212 | -- expression is an actual in a call, it has not been expanded, | |
5213 | -- waiting for the proper point at which to do it. The same happens | |
5214 | -- with renamings, so that we have to force the expansion now. This | |
5215 | -- non-local complication is due to code in exp_ch2,adb, exp_ch4.adb | |
5216 | -- and exp_ch6.adb. | |
5217 | ||
5218 | if Is_Entity_Name (Exp) | |
5219 | and then Nkind (Parent (Entity (Exp))) = | |
5220 | N_Object_Renaming_Declaration | |
5221 | then | |
5222 | declare | |
5223 | Old_Exp : constant Node_Id := Name (Parent (Entity (Exp))); | |
5224 | begin | |
5225 | if Nkind (Old_Exp) = N_Indexed_Component | |
5226 | and then Is_Bit_Packed_Array (Etype (Prefix (Old_Exp))) | |
5227 | then | |
5228 | Expand_Packed_Element_Reference (Old_Exp); | |
5229 | end if; | |
5230 | end; | |
5231 | end if; | |
5232 | ||
5233 | -- Put back the Do_Range_Check flag on the resulting (possibly | |
5234 | -- rewritten) expression. | |
5235 | ||
5236 | -- Note: it might be thought that a validity check is not required | |
5237 | -- when a range check is present, but that's not the case, because | |
5238 | -- the back end is allowed to assume for the range check that the | |
5239 | -- operand is within its declared range (an assumption that validity | |
5240 | -- checking is all about NOT assuming!) | |
5241 | ||
00c403ee | 5242 | -- Note: no need to worry about Possible_Local_Raise here, it will |
5243 | -- already have been called if original node has Do_Range_Check set. | |
5244 | ||
0577b0b1 | 5245 | Set_Do_Range_Check (Exp, DRC); |
5246 | end; | |
ee6ba406 | 5247 | end Insert_Valid_Check; |
5248 | ||
fa7497e8 | 5249 | ---------------------------------- |
5250 | -- Install_Null_Excluding_Check -- | |
5251 | ---------------------------------- | |
5252 | ||
5253 | procedure Install_Null_Excluding_Check (N : Node_Id) is | |
84d0d4a5 | 5254 | Loc : constant Source_Ptr := Sloc (N); |
5255 | Typ : constant Entity_Id := Etype (N); | |
5256 | ||
7870823d | 5257 | function In_Declarative_Region_Of_Subprogram_Body return Boolean; |
5258 | -- Determine whether node N, a reference to an *in* parameter, is | |
5259 | -- inside the declarative region of the current subprogram body. | |
5260 | ||
84d0d4a5 | 5261 | procedure Mark_Non_Null; |
7870823d | 5262 | -- After installation of check, if the node in question is an entity |
5263 | -- name, then mark this entity as non-null if possible. | |
5264 | ||
5265 | ---------------------------------------------- | |
5266 | -- In_Declarative_Region_Of_Subprogram_Body -- | |
5267 | ---------------------------------------------- | |
5268 | ||
5269 | function In_Declarative_Region_Of_Subprogram_Body return Boolean is | |
5270 | E : constant Entity_Id := Entity (N); | |
5271 | S : constant Entity_Id := Current_Scope; | |
5272 | S_Par : Node_Id; | |
5273 | ||
5274 | begin | |
5275 | pragma Assert (Ekind (E) = E_In_Parameter); | |
5276 | ||
5277 | -- Two initial context checks. We must be inside a subprogram body | |
5278 | -- with declarations and reference must not appear in nested scopes. | |
5279 | ||
5280 | if (Ekind (S) /= E_Function | |
5281 | and then Ekind (S) /= E_Procedure) | |
5282 | or else Scope (E) /= S | |
5283 | then | |
5284 | return False; | |
5285 | end if; | |
5286 | ||
5287 | S_Par := Parent (Parent (S)); | |
5288 | ||
5289 | if Nkind (S_Par) /= N_Subprogram_Body | |
5290 | or else No (Declarations (S_Par)) | |
5291 | then | |
5292 | return False; | |
5293 | end if; | |
5294 | ||
5295 | declare | |
5296 | N_Decl : Node_Id; | |
5297 | P : Node_Id; | |
5298 | ||
5299 | begin | |
5300 | -- Retrieve the declaration node of N (if any). Note that N | |
5301 | -- may be a part of a complex initialization expression. | |
5302 | ||
5303 | P := Parent (N); | |
5304 | N_Decl := Empty; | |
5305 | while Present (P) loop | |
5306 | ||
5307 | -- While traversing the parent chain, we find that N | |
5308 | -- belongs to a statement, thus it may never appear in | |
5309 | -- a declarative region. | |
5310 | ||
5311 | if Nkind (P) in N_Statement_Other_Than_Procedure_Call | |
5312 | or else Nkind (P) = N_Procedure_Call_Statement | |
5313 | then | |
5314 | return False; | |
5315 | end if; | |
5316 | ||
5317 | if Nkind (P) in N_Declaration | |
5318 | and then Nkind (P) not in N_Subprogram_Specification | |
5319 | then | |
5320 | N_Decl := P; | |
5321 | exit; | |
5322 | end if; | |
5323 | ||
5324 | P := Parent (P); | |
5325 | end loop; | |
5326 | ||
5327 | if No (N_Decl) then | |
5328 | return False; | |
5329 | end if; | |
5330 | ||
5331 | return List_Containing (N_Decl) = Declarations (S_Par); | |
5332 | end; | |
5333 | end In_Declarative_Region_Of_Subprogram_Body; | |
84d0d4a5 | 5334 | |
5335 | ------------------- | |
5336 | -- Mark_Non_Null -- | |
5337 | ------------------- | |
5338 | ||
5339 | procedure Mark_Non_Null is | |
5340 | begin | |
7870823d | 5341 | -- Only case of interest is if node N is an entity name |
5342 | ||
84d0d4a5 | 5343 | if Is_Entity_Name (N) then |
7870823d | 5344 | |
5345 | -- For sure, we want to clear an indication that this is known to | |
5346 | -- be null, since if we get past this check, it definitely is not! | |
5347 | ||
84d0d4a5 | 5348 | Set_Is_Known_Null (Entity (N), False); |
5349 | ||
7870823d | 5350 | -- We can mark the entity as known to be non-null if either it is |
5351 | -- safe to capture the value, or in the case of an IN parameter, | |
5352 | -- which is a constant, if the check we just installed is in the | |
5353 | -- declarative region of the subprogram body. In this latter case, | |
5354 | -- a check is decisive for the rest of the body, since we know we | |
5355 | -- must complete all declarations before executing the body. | |
5356 | ||
5357 | if Safe_To_Capture_Value (N, Entity (N)) | |
5358 | or else | |
5359 | (Ekind (Entity (N)) = E_In_Parameter | |
5360 | and then In_Declarative_Region_Of_Subprogram_Body) | |
5361 | then | |
5362 | Set_Is_Known_Non_Null (Entity (N)); | |
84d0d4a5 | 5363 | end if; |
5364 | end if; | |
5365 | end Mark_Non_Null; | |
5366 | ||
5367 | -- Start of processing for Install_Null_Excluding_Check | |
fa7497e8 | 5368 | |
5369 | begin | |
84d0d4a5 | 5370 | pragma Assert (Is_Access_Type (Typ)); |
fa7497e8 | 5371 | |
84d0d4a5 | 5372 | -- No check inside a generic (why not???) |
fa7497e8 | 5373 | |
84d0d4a5 | 5374 | if Inside_A_Generic then |
fa7497e8 | 5375 | return; |
84d0d4a5 | 5376 | end if; |
5377 | ||
5378 | -- No check needed if known to be non-null | |
5379 | ||
5380 | if Known_Non_Null (N) then | |
05fcfafb | 5381 | return; |
84d0d4a5 | 5382 | end if; |
fa7497e8 | 5383 | |
84d0d4a5 | 5384 | -- If known to be null, here is where we generate a compile time check |
5385 | ||
5386 | if Known_Null (N) then | |
d16989f1 | 5387 | |
5388 | -- Avoid generating warning message inside init procs | |
5389 | ||
5390 | if not Inside_Init_Proc then | |
5391 | Apply_Compile_Time_Constraint_Error | |
5392 | (N, | |
5393 | "null value not allowed here?", | |
5394 | CE_Access_Check_Failed); | |
5395 | else | |
5396 | Insert_Action (N, | |
5397 | Make_Raise_Constraint_Error (Loc, | |
5398 | Reason => CE_Access_Check_Failed)); | |
5399 | end if; | |
5400 | ||
84d0d4a5 | 5401 | Mark_Non_Null; |
5402 | return; | |
5403 | end if; | |
5404 | ||
5405 | -- If entity is never assigned, for sure a warning is appropriate | |
5406 | ||
5407 | if Is_Entity_Name (N) then | |
5408 | Check_Unset_Reference (N); | |
fa7497e8 | 5409 | end if; |
84d0d4a5 | 5410 | |
5411 | -- No check needed if checks are suppressed on the range. Note that we | |
5412 | -- don't set Is_Known_Non_Null in this case (we could legitimately do | |
5413 | -- so, since the program is erroneous, but we don't like to casually | |
5414 | -- propagate such conclusions from erroneosity). | |
5415 | ||
5416 | if Access_Checks_Suppressed (Typ) then | |
5417 | return; | |
5418 | end if; | |
5419 | ||
2af58f67 | 5420 | -- No check needed for access to concurrent record types generated by |
5421 | -- the expander. This is not just an optimization (though it does indeed | |
5422 | -- remove junk checks). It also avoids generation of junk warnings. | |
5423 | ||
5424 | if Nkind (N) in N_Has_Chars | |
5425 | and then Chars (N) = Name_uObject | |
5426 | and then Is_Concurrent_Record_Type | |
5427 | (Directly_Designated_Type (Etype (N))) | |
5428 | then | |
5429 | return; | |
5430 | end if; | |
5431 | ||
84d0d4a5 | 5432 | -- Otherwise install access check |
5433 | ||
5434 | Insert_Action (N, | |
5435 | Make_Raise_Constraint_Error (Loc, | |
5436 | Condition => | |
5437 | Make_Op_Eq (Loc, | |
5438 | Left_Opnd => Duplicate_Subexpr_Move_Checks (N), | |
5439 | Right_Opnd => Make_Null (Loc)), | |
5440 | Reason => CE_Access_Check_Failed)); | |
5441 | ||
5442 | Mark_Non_Null; | |
fa7497e8 | 5443 | end Install_Null_Excluding_Check; |
5444 | ||
ee6ba406 | 5445 | -------------------------- |
5446 | -- Install_Static_Check -- | |
5447 | -------------------------- | |
5448 | ||
5449 | procedure Install_Static_Check (R_Cno : Node_Id; Loc : Source_Ptr) is | |
5450 | Stat : constant Boolean := Is_Static_Expression (R_Cno); | |
5451 | Typ : constant Entity_Id := Etype (R_Cno); | |
5452 | ||
5453 | begin | |
f15731c4 | 5454 | Rewrite (R_Cno, |
5455 | Make_Raise_Constraint_Error (Loc, | |
5456 | Reason => CE_Range_Check_Failed)); | |
ee6ba406 | 5457 | Set_Analyzed (R_Cno); |
5458 | Set_Etype (R_Cno, Typ); | |
5459 | Set_Raises_Constraint_Error (R_Cno); | |
5460 | Set_Is_Static_Expression (R_Cno, Stat); | |
840ab274 | 5461 | |
5462 | -- Now deal with possible local raise handling | |
5463 | ||
5464 | Possible_Local_Raise (R_Cno, Standard_Constraint_Error); | |
ee6ba406 | 5465 | end Install_Static_Check; |
5466 | ||
9dfe12ae | 5467 | --------------------- |
5468 | -- Kill_All_Checks -- | |
5469 | --------------------- | |
5470 | ||
5471 | procedure Kill_All_Checks is | |
5472 | begin | |
5473 | if Debug_Flag_CC then | |
5474 | w ("Kill_All_Checks"); | |
5475 | end if; | |
5476 | ||
feff2f05 | 5477 | -- We reset the number of saved checks to zero, and also modify all |
5478 | -- stack entries for statement ranges to indicate that the number of | |
5479 | -- checks at each level is now zero. | |
9dfe12ae | 5480 | |
5481 | Num_Saved_Checks := 0; | |
5482 | ||
96da3284 | 5483 | -- Note: the Int'Min here avoids any possibility of J being out of |
5484 | -- range when called from e.g. Conditional_Statements_Begin. | |
5485 | ||
5486 | for J in 1 .. Int'Min (Saved_Checks_TOS, Saved_Checks_Stack'Last) loop | |
9dfe12ae | 5487 | Saved_Checks_Stack (J) := 0; |
5488 | end loop; | |
5489 | end Kill_All_Checks; | |
5490 | ||
5491 | ----------------- | |
5492 | -- Kill_Checks -- | |
5493 | ----------------- | |
5494 | ||
5495 | procedure Kill_Checks (V : Entity_Id) is | |
5496 | begin | |
5497 | if Debug_Flag_CC then | |
5498 | w ("Kill_Checks for entity", Int (V)); | |
5499 | end if; | |
5500 | ||
5501 | for J in 1 .. Num_Saved_Checks loop | |
5502 | if Saved_Checks (J).Entity = V then | |
5503 | if Debug_Flag_CC then | |
5504 | w (" Checks killed for saved check ", J); | |
5505 | end if; | |
5506 | ||
5507 | Saved_Checks (J).Killed := True; | |
5508 | end if; | |
5509 | end loop; | |
5510 | end Kill_Checks; | |
5511 | ||
ee6ba406 | 5512 | ------------------------------ |
5513 | -- Length_Checks_Suppressed -- | |
5514 | ------------------------------ | |
5515 | ||
5516 | function Length_Checks_Suppressed (E : Entity_Id) return Boolean is | |
5517 | begin | |
9dfe12ae | 5518 | if Present (E) and then Checks_May_Be_Suppressed (E) then |
5519 | return Is_Check_Suppressed (E, Length_Check); | |
5520 | else | |
5521 | return Scope_Suppress (Length_Check); | |
5522 | end if; | |
ee6ba406 | 5523 | end Length_Checks_Suppressed; |
5524 | ||
5525 | -------------------------------- | |
5526 | -- Overflow_Checks_Suppressed -- | |
5527 | -------------------------------- | |
5528 | ||
5529 | function Overflow_Checks_Suppressed (E : Entity_Id) return Boolean is | |
5530 | begin | |
9dfe12ae | 5531 | if Present (E) and then Checks_May_Be_Suppressed (E) then |
5532 | return Is_Check_Suppressed (E, Overflow_Check); | |
5533 | else | |
5534 | return Scope_Suppress (Overflow_Check); | |
5535 | end if; | |
ee6ba406 | 5536 | end Overflow_Checks_Suppressed; |
fc75802a | 5537 | |
ee6ba406 | 5538 | ----------------------------- |
5539 | -- Range_Checks_Suppressed -- | |
5540 | ----------------------------- | |
5541 | ||
5542 | function Range_Checks_Suppressed (E : Entity_Id) return Boolean is | |
5543 | begin | |
9dfe12ae | 5544 | if Present (E) then |
5545 | ||
5546 | -- Note: for now we always suppress range checks on Vax float types, | |
5547 | -- since Gigi does not know how to generate these checks. | |
5548 | ||
5549 | if Vax_Float (E) then | |
5550 | return True; | |
5551 | elsif Kill_Range_Checks (E) then | |
5552 | return True; | |
5553 | elsif Checks_May_Be_Suppressed (E) then | |
5554 | return Is_Check_Suppressed (E, Range_Check); | |
5555 | end if; | |
5556 | end if; | |
ee6ba406 | 5557 | |
9dfe12ae | 5558 | return Scope_Suppress (Range_Check); |
ee6ba406 | 5559 | end Range_Checks_Suppressed; |
5560 | ||
0577b0b1 | 5561 | ----------------------------------------- |
5562 | -- Range_Or_Validity_Checks_Suppressed -- | |
5563 | ----------------------------------------- | |
5564 | ||
5565 | -- Note: the coding would be simpler here if we simply made appropriate | |
5566 | -- calls to Range/Validity_Checks_Suppressed, but that would result in | |
5567 | -- duplicated checks which we prefer to avoid. | |
5568 | ||
5569 | function Range_Or_Validity_Checks_Suppressed | |
5570 | (Expr : Node_Id) return Boolean | |
5571 | is | |
5572 | begin | |
5573 | -- Immediate return if scope checks suppressed for either check | |
5574 | ||
5575 | if Scope_Suppress (Range_Check) or Scope_Suppress (Validity_Check) then | |
5576 | return True; | |
5577 | end if; | |
5578 | ||
5579 | -- If no expression, that's odd, decide that checks are suppressed, | |
5580 | -- since we don't want anyone trying to do checks in this case, which | |
5581 | -- is most likely the result of some other error. | |
5582 | ||
5583 | if No (Expr) then | |
5584 | return True; | |
5585 | end if; | |
5586 | ||
5587 | -- Expression is present, so perform suppress checks on type | |
5588 | ||
5589 | declare | |
5590 | Typ : constant Entity_Id := Etype (Expr); | |
5591 | begin | |
5592 | if Vax_Float (Typ) then | |
5593 | return True; | |
5594 | elsif Checks_May_Be_Suppressed (Typ) | |
5595 | and then (Is_Check_Suppressed (Typ, Range_Check) | |
5596 | or else | |
5597 | Is_Check_Suppressed (Typ, Validity_Check)) | |
5598 | then | |
5599 | return True; | |
5600 | end if; | |
5601 | end; | |
5602 | ||
5603 | -- If expression is an entity name, perform checks on this entity | |
5604 | ||
5605 | if Is_Entity_Name (Expr) then | |
5606 | declare | |
5607 | Ent : constant Entity_Id := Entity (Expr); | |
5608 | begin | |
5609 | if Checks_May_Be_Suppressed (Ent) then | |
5610 | return Is_Check_Suppressed (Ent, Range_Check) | |
5611 | or else Is_Check_Suppressed (Ent, Validity_Check); | |
5612 | end if; | |
5613 | end; | |
5614 | end if; | |
5615 | ||
5616 | -- If we fall through, no checks suppressed | |
5617 | ||
5618 | return False; | |
5619 | end Range_Or_Validity_Checks_Suppressed; | |
5620 | ||
226494a3 | 5621 | ------------------- |
5622 | -- Remove_Checks -- | |
5623 | ------------------- | |
5624 | ||
5625 | procedure Remove_Checks (Expr : Node_Id) is | |
226494a3 | 5626 | function Process (N : Node_Id) return Traverse_Result; |
5627 | -- Process a single node during the traversal | |
5628 | ||
8f6e4fd5 | 5629 | procedure Traverse is new Traverse_Proc (Process); |
5630 | -- The traversal procedure itself | |
226494a3 | 5631 | |
5632 | ------------- | |
5633 | -- Process -- | |
5634 | ------------- | |
5635 | ||
5636 | function Process (N : Node_Id) return Traverse_Result is | |
5637 | begin | |
5638 | if Nkind (N) not in N_Subexpr then | |
5639 | return Skip; | |
5640 | end if; | |
5641 | ||
5642 | Set_Do_Range_Check (N, False); | |
5643 | ||
5644 | case Nkind (N) is | |
5645 | when N_And_Then => | |
8f6e4fd5 | 5646 | Traverse (Left_Opnd (N)); |
226494a3 | 5647 | return Skip; |
5648 | ||
5649 | when N_Attribute_Reference => | |
226494a3 | 5650 | Set_Do_Overflow_Check (N, False); |
5651 | ||
226494a3 | 5652 | when N_Function_Call => |
5653 | Set_Do_Tag_Check (N, False); | |
5654 | ||
226494a3 | 5655 | when N_Op => |
5656 | Set_Do_Overflow_Check (N, False); | |
5657 | ||
5658 | case Nkind (N) is | |
5659 | when N_Op_Divide => | |
5660 | Set_Do_Division_Check (N, False); | |
5661 | ||
5662 | when N_Op_And => | |
5663 | Set_Do_Length_Check (N, False); | |
5664 | ||
5665 | when N_Op_Mod => | |
5666 | Set_Do_Division_Check (N, False); | |
5667 | ||
5668 | when N_Op_Or => | |
5669 | Set_Do_Length_Check (N, False); | |
5670 | ||
5671 | when N_Op_Rem => | |
5672 | Set_Do_Division_Check (N, False); | |
5673 | ||
5674 | when N_Op_Xor => | |
5675 | Set_Do_Length_Check (N, False); | |
5676 | ||
5677 | when others => | |
5678 | null; | |
5679 | end case; | |
5680 | ||
5681 | when N_Or_Else => | |
8f6e4fd5 | 5682 | Traverse (Left_Opnd (N)); |
226494a3 | 5683 | return Skip; |
5684 | ||
5685 | when N_Selected_Component => | |
226494a3 | 5686 | Set_Do_Discriminant_Check (N, False); |
5687 | ||
226494a3 | 5688 | when N_Type_Conversion => |
9dfe12ae | 5689 | Set_Do_Length_Check (N, False); |
5690 | Set_Do_Tag_Check (N, False); | |
226494a3 | 5691 | Set_Do_Overflow_Check (N, False); |
226494a3 | 5692 | |
5693 | when others => | |
5694 | null; | |
5695 | end case; | |
5696 | ||
5697 | return OK; | |
5698 | end Process; | |
5699 | ||
5700 | -- Start of processing for Remove_Checks | |
5701 | ||
5702 | begin | |
8f6e4fd5 | 5703 | Traverse (Expr); |
226494a3 | 5704 | end Remove_Checks; |
5705 | ||
ee6ba406 | 5706 | ---------------------------- |
5707 | -- Selected_Length_Checks -- | |
5708 | ---------------------------- | |
5709 | ||
5710 | function Selected_Length_Checks | |
5711 | (Ck_Node : Node_Id; | |
5712 | Target_Typ : Entity_Id; | |
5713 | Source_Typ : Entity_Id; | |
314a23b6 | 5714 | Warn_Node : Node_Id) return Check_Result |
ee6ba406 | 5715 | is |
5716 | Loc : constant Source_Ptr := Sloc (Ck_Node); | |
5717 | S_Typ : Entity_Id; | |
5718 | T_Typ : Entity_Id; | |
5719 | Expr_Actual : Node_Id; | |
5720 | Exptyp : Entity_Id; | |
5721 | Cond : Node_Id := Empty; | |
5722 | Do_Access : Boolean := False; | |
5723 | Wnode : Node_Id := Warn_Node; | |
5724 | Ret_Result : Check_Result := (Empty, Empty); | |
5725 | Num_Checks : Natural := 0; | |
5726 | ||
5727 | procedure Add_Check (N : Node_Id); | |
5728 | -- Adds the action given to Ret_Result if N is non-Empty | |
5729 | ||
5730 | function Get_E_Length (E : Entity_Id; Indx : Nat) return Node_Id; | |
5731 | function Get_N_Length (N : Node_Id; Indx : Nat) return Node_Id; | |
314a23b6 | 5732 | -- Comments required ??? |
ee6ba406 | 5733 | |
5734 | function Same_Bounds (L : Node_Id; R : Node_Id) return Boolean; | |
5735 | -- True for equal literals and for nodes that denote the same constant | |
5f260d20 | 5736 | -- entity, even if its value is not a static constant. This includes the |
9dfe12ae | 5737 | -- case of a discriminal reference within an init proc. Removes some |
5f260d20 | 5738 | -- obviously superfluous checks. |
ee6ba406 | 5739 | |
5740 | function Length_E_Cond | |
5741 | (Exptyp : Entity_Id; | |
5742 | Typ : Entity_Id; | |
314a23b6 | 5743 | Indx : Nat) return Node_Id; |
ee6ba406 | 5744 | -- Returns expression to compute: |
5745 | -- Typ'Length /= Exptyp'Length | |
5746 | ||
5747 | function Length_N_Cond | |
5748 | (Expr : Node_Id; | |
5749 | Typ : Entity_Id; | |
314a23b6 | 5750 | Indx : Nat) return Node_Id; |
ee6ba406 | 5751 | -- Returns expression to compute: |
5752 | -- Typ'Length /= Expr'Length | |
5753 | ||
5754 | --------------- | |
5755 | -- Add_Check -- | |
5756 | --------------- | |
5757 | ||
5758 | procedure Add_Check (N : Node_Id) is | |
5759 | begin | |
5760 | if Present (N) then | |
5761 | ||
5762 | -- For now, ignore attempt to place more than 2 checks ??? | |
5763 | ||
5764 | if Num_Checks = 2 then | |
5765 | return; | |
5766 | end if; | |
5767 | ||
5768 | pragma Assert (Num_Checks <= 1); | |
5769 | Num_Checks := Num_Checks + 1; | |
5770 | Ret_Result (Num_Checks) := N; | |
5771 | end if; | |
5772 | end Add_Check; | |
5773 | ||
5774 | ------------------ | |
5775 | -- Get_E_Length -- | |
5776 | ------------------ | |
5777 | ||
5778 | function Get_E_Length (E : Entity_Id; Indx : Nat) return Node_Id is | |
00c403ee | 5779 | SE : constant Entity_Id := Scope (E); |
ee6ba406 | 5780 | N : Node_Id; |
5781 | E1 : Entity_Id := E; | |
ee6ba406 | 5782 | |
5783 | begin | |
5784 | if Ekind (Scope (E)) = E_Record_Type | |
5785 | and then Has_Discriminants (Scope (E)) | |
5786 | then | |
5787 | N := Build_Discriminal_Subtype_Of_Component (E); | |
5788 | ||
5789 | if Present (N) then | |
5790 | Insert_Action (Ck_Node, N); | |
5791 | E1 := Defining_Identifier (N); | |
5792 | end if; | |
5793 | end if; | |
5794 | ||
5795 | if Ekind (E1) = E_String_Literal_Subtype then | |
5796 | return | |
5797 | Make_Integer_Literal (Loc, | |
5798 | Intval => String_Literal_Length (E1)); | |
5799 | ||
00c403ee | 5800 | elsif SE /= Standard_Standard |
5801 | and then Ekind (Scope (SE)) = E_Protected_Type | |
5802 | and then Has_Discriminants (Scope (SE)) | |
5803 | and then Has_Completion (Scope (SE)) | |
ee6ba406 | 5804 | and then not Inside_Init_Proc |
5805 | then | |
ee6ba406 | 5806 | -- If the type whose length is needed is a private component |
5807 | -- constrained by a discriminant, we must expand the 'Length | |
5808 | -- attribute into an explicit computation, using the discriminal | |
5809 | -- of the current protected operation. This is because the actual | |
5810 | -- type of the prival is constructed after the protected opera- | |
5811 | -- tion has been fully expanded. | |
5812 | ||
5813 | declare | |
5814 | Indx_Type : Node_Id; | |
5815 | Lo : Node_Id; | |
5816 | Hi : Node_Id; | |
5817 | Do_Expand : Boolean := False; | |
5818 | ||
5819 | begin | |
5820 | Indx_Type := First_Index (E); | |
5821 | ||
5822 | for J in 1 .. Indx - 1 loop | |
5823 | Next_Index (Indx_Type); | |
5824 | end loop; | |
5825 | ||
2af58f67 | 5826 | Get_Index_Bounds (Indx_Type, Lo, Hi); |
ee6ba406 | 5827 | |
5828 | if Nkind (Lo) = N_Identifier | |
5829 | and then Ekind (Entity (Lo)) = E_In_Parameter | |
5830 | then | |
5831 | Lo := Get_Discriminal (E, Lo); | |
5832 | Do_Expand := True; | |
5833 | end if; | |
5834 | ||
5835 | if Nkind (Hi) = N_Identifier | |
5836 | and then Ekind (Entity (Hi)) = E_In_Parameter | |
5837 | then | |
5838 | Hi := Get_Discriminal (E, Hi); | |
5839 | Do_Expand := True; | |
5840 | end if; | |
5841 | ||
5842 | if Do_Expand then | |
5843 | if not Is_Entity_Name (Lo) then | |
9dfe12ae | 5844 | Lo := Duplicate_Subexpr_No_Checks (Lo); |
ee6ba406 | 5845 | end if; |
5846 | ||
5847 | if not Is_Entity_Name (Hi) then | |
9dfe12ae | 5848 | Lo := Duplicate_Subexpr_No_Checks (Hi); |
ee6ba406 | 5849 | end if; |
5850 | ||
5851 | N := | |
5852 | Make_Op_Add (Loc, | |
5853 | Left_Opnd => | |
5854 | Make_Op_Subtract (Loc, | |
5855 | Left_Opnd => Hi, | |
5856 | Right_Opnd => Lo), | |
5857 | ||
5858 | Right_Opnd => Make_Integer_Literal (Loc, 1)); | |
5859 | return N; | |
5860 | ||
5861 | else | |
5862 | N := | |
5863 | Make_Attribute_Reference (Loc, | |
5864 | Attribute_Name => Name_Length, | |
5865 | Prefix => | |
5866 | New_Occurrence_Of (E1, Loc)); | |
5867 | ||
5868 | if Indx > 1 then | |
5869 | Set_Expressions (N, New_List ( | |
5870 | Make_Integer_Literal (Loc, Indx))); | |
5871 | end if; | |
5872 | ||
5873 | return N; | |
5874 | end if; | |
5875 | end; | |
5876 | ||
5877 | else | |
5878 | N := | |
5879 | Make_Attribute_Reference (Loc, | |
5880 | Attribute_Name => Name_Length, | |
5881 | Prefix => | |
5882 | New_Occurrence_Of (E1, Loc)); | |
5883 | ||
5884 | if Indx > 1 then | |
5885 | Set_Expressions (N, New_List ( | |
5886 | Make_Integer_Literal (Loc, Indx))); | |
5887 | end if; | |
5888 | ||
5889 | return N; | |
ee6ba406 | 5890 | end if; |
5891 | end Get_E_Length; | |
5892 | ||
5893 | ------------------ | |
5894 | -- Get_N_Length -- | |
5895 | ------------------ | |
5896 | ||
5897 | function Get_N_Length (N : Node_Id; Indx : Nat) return Node_Id is | |
5898 | begin | |
5899 | return | |
5900 | Make_Attribute_Reference (Loc, | |
5901 | Attribute_Name => Name_Length, | |
5902 | Prefix => | |
9dfe12ae | 5903 | Duplicate_Subexpr_No_Checks (N, Name_Req => True), |
ee6ba406 | 5904 | Expressions => New_List ( |
5905 | Make_Integer_Literal (Loc, Indx))); | |
ee6ba406 | 5906 | end Get_N_Length; |
5907 | ||
5908 | ------------------- | |
5909 | -- Length_E_Cond -- | |
5910 | ------------------- | |
5911 | ||
5912 | function Length_E_Cond | |
5913 | (Exptyp : Entity_Id; | |
5914 | Typ : Entity_Id; | |
314a23b6 | 5915 | Indx : Nat) return Node_Id |
ee6ba406 | 5916 | is |
5917 | begin | |
5918 | return | |
5919 | Make_Op_Ne (Loc, | |
5920 | Left_Opnd => Get_E_Length (Typ, Indx), | |
5921 | Right_Opnd => Get_E_Length (Exptyp, Indx)); | |
ee6ba406 | 5922 | end Length_E_Cond; |
5923 | ||
5924 | ------------------- | |
5925 | -- Length_N_Cond -- | |
5926 | ------------------- | |
5927 | ||
5928 | function Length_N_Cond | |
5929 | (Expr : Node_Id; | |
5930 | Typ : Entity_Id; | |
314a23b6 | 5931 | Indx : Nat) return Node_Id |
ee6ba406 | 5932 | is |
5933 | begin | |
5934 | return | |
5935 | Make_Op_Ne (Loc, | |
5936 | Left_Opnd => Get_E_Length (Typ, Indx), | |
5937 | Right_Opnd => Get_N_Length (Expr, Indx)); | |
ee6ba406 | 5938 | end Length_N_Cond; |
5939 | ||
feff2f05 | 5940 | ----------------- |
5941 | -- Same_Bounds -- | |
5942 | ----------------- | |
5943 | ||
ee6ba406 | 5944 | function Same_Bounds (L : Node_Id; R : Node_Id) return Boolean is |
5945 | begin | |
5946 | return | |
5947 | (Nkind (L) = N_Integer_Literal | |
5948 | and then Nkind (R) = N_Integer_Literal | |
5949 | and then Intval (L) = Intval (R)) | |
5950 | ||
5951 | or else | |
5952 | (Is_Entity_Name (L) | |
5953 | and then Ekind (Entity (L)) = E_Constant | |
5954 | and then ((Is_Entity_Name (R) | |
5955 | and then Entity (L) = Entity (R)) | |
5956 | or else | |
5957 | (Nkind (R) = N_Type_Conversion | |
5958 | and then Is_Entity_Name (Expression (R)) | |
5959 | and then Entity (L) = Entity (Expression (R))))) | |
5960 | ||
5961 | or else | |
5962 | (Is_Entity_Name (R) | |
5963 | and then Ekind (Entity (R)) = E_Constant | |
5964 | and then Nkind (L) = N_Type_Conversion | |
5965 | and then Is_Entity_Name (Expression (L)) | |
5f260d20 | 5966 | and then Entity (R) = Entity (Expression (L))) |
5967 | ||
5968 | or else | |
5969 | (Is_Entity_Name (L) | |
5970 | and then Is_Entity_Name (R) | |
5971 | and then Entity (L) = Entity (R) | |
5972 | and then Ekind (Entity (L)) = E_In_Parameter | |
5973 | and then Inside_Init_Proc); | |
ee6ba406 | 5974 | end Same_Bounds; |
5975 | ||
5976 | -- Start of processing for Selected_Length_Checks | |
5977 | ||
5978 | begin | |
5979 | if not Expander_Active then | |
5980 | return Ret_Result; | |
5981 | end if; | |
5982 | ||
5983 | if Target_Typ = Any_Type | |
5984 | or else Target_Typ = Any_Composite | |
5985 | or else Raises_Constraint_Error (Ck_Node) | |
5986 | then | |
5987 | return Ret_Result; | |
5988 | end if; | |
5989 | ||
5990 | if No (Wnode) then | |
5991 | Wnode := Ck_Node; | |
5992 | end if; | |
5993 | ||
5994 | T_Typ := Target_Typ; | |
5995 | ||
5996 | if No (Source_Typ) then | |
5997 | S_Typ := Etype (Ck_Node); | |
5998 | else | |
5999 | S_Typ := Source_Typ; | |
6000 | end if; | |
6001 | ||
6002 | if S_Typ = Any_Type or else S_Typ = Any_Composite then | |
6003 | return Ret_Result; | |
6004 | end if; | |
6005 | ||
6006 | if Is_Access_Type (T_Typ) and then Is_Access_Type (S_Typ) then | |
6007 | S_Typ := Designated_Type (S_Typ); | |
6008 | T_Typ := Designated_Type (T_Typ); | |
6009 | Do_Access := True; | |
6010 | ||
2af58f67 | 6011 | -- A simple optimization for the null case |
ee6ba406 | 6012 | |
2af58f67 | 6013 | if Known_Null (Ck_Node) then |
ee6ba406 | 6014 | return Ret_Result; |
6015 | end if; | |
6016 | end if; | |
6017 | ||
6018 | if Is_Array_Type (T_Typ) and then Is_Array_Type (S_Typ) then | |
6019 | if Is_Constrained (T_Typ) then | |
6020 | ||
6021 | -- The checking code to be generated will freeze the | |
6022 | -- corresponding array type. However, we must freeze the | |
6023 | -- type now, so that the freeze node does not appear within | |
6024 | -- the generated condional expression, but ahead of it. | |
6025 | ||
6026 | Freeze_Before (Ck_Node, T_Typ); | |
6027 | ||
6028 | Expr_Actual := Get_Referenced_Object (Ck_Node); | |
84d0d4a5 | 6029 | Exptyp := Get_Actual_Subtype (Ck_Node); |
ee6ba406 | 6030 | |
6031 | if Is_Access_Type (Exptyp) then | |
6032 | Exptyp := Designated_Type (Exptyp); | |
6033 | end if; | |
6034 | ||
6035 | -- String_Literal case. This needs to be handled specially be- | |
6036 | -- cause no index types are available for string literals. The | |
6037 | -- condition is simply: | |
6038 | ||
6039 | -- T_Typ'Length = string-literal-length | |
6040 | ||
9dfe12ae | 6041 | if Nkind (Expr_Actual) = N_String_Literal |
6042 | and then Ekind (Etype (Expr_Actual)) = E_String_Literal_Subtype | |
6043 | then | |
ee6ba406 | 6044 | Cond := |
6045 | Make_Op_Ne (Loc, | |
6046 | Left_Opnd => Get_E_Length (T_Typ, 1), | |
6047 | Right_Opnd => | |
6048 | Make_Integer_Literal (Loc, | |
6049 | Intval => | |
6050 | String_Literal_Length (Etype (Expr_Actual)))); | |
6051 | ||
6052 | -- General array case. Here we have a usable actual subtype for | |
6053 | -- the expression, and the condition is built from the two types | |
6054 | -- (Do_Length): | |
6055 | ||
6056 | -- T_Typ'Length /= Exptyp'Length or else | |
6057 | -- T_Typ'Length (2) /= Exptyp'Length (2) or else | |
6058 | -- T_Typ'Length (3) /= Exptyp'Length (3) or else | |
6059 | -- ... | |
6060 | ||
6061 | elsif Is_Constrained (Exptyp) then | |
6062 | declare | |
9dfe12ae | 6063 | Ndims : constant Nat := Number_Dimensions (T_Typ); |
6064 | ||
6065 | L_Index : Node_Id; | |
6066 | R_Index : Node_Id; | |
6067 | L_Low : Node_Id; | |
6068 | L_High : Node_Id; | |
6069 | R_Low : Node_Id; | |
6070 | R_High : Node_Id; | |
ee6ba406 | 6071 | L_Length : Uint; |
6072 | R_Length : Uint; | |
9dfe12ae | 6073 | Ref_Node : Node_Id; |
ee6ba406 | 6074 | |
6075 | begin | |
feff2f05 | 6076 | -- At the library level, we need to ensure that the type of |
6077 | -- the object is elaborated before the check itself is | |
6078 | -- emitted. This is only done if the object is in the | |
6079 | -- current compilation unit, otherwise the type is frozen | |
6080 | -- and elaborated in its unit. | |
9dfe12ae | 6081 | |
6082 | if Is_Itype (Exptyp) | |
6083 | and then | |
6084 | Ekind (Cunit_Entity (Current_Sem_Unit)) = E_Package | |
6085 | and then | |
6086 | not In_Package_Body (Cunit_Entity (Current_Sem_Unit)) | |
d66aa9f6 | 6087 | and then In_Open_Scopes (Scope (Exptyp)) |
9dfe12ae | 6088 | then |
6089 | Ref_Node := Make_Itype_Reference (Sloc (Ck_Node)); | |
6090 | Set_Itype (Ref_Node, Exptyp); | |
6091 | Insert_Action (Ck_Node, Ref_Node); | |
6092 | end if; | |
6093 | ||
ee6ba406 | 6094 | L_Index := First_Index (T_Typ); |
6095 | R_Index := First_Index (Exptyp); | |
6096 | ||
6097 | for Indx in 1 .. Ndims loop | |
6098 | if not (Nkind (L_Index) = N_Raise_Constraint_Error | |
f15731c4 | 6099 | or else |
6100 | Nkind (R_Index) = N_Raise_Constraint_Error) | |
ee6ba406 | 6101 | then |
6102 | Get_Index_Bounds (L_Index, L_Low, L_High); | |
6103 | Get_Index_Bounds (R_Index, R_Low, R_High); | |
6104 | ||
6105 | -- Deal with compile time length check. Note that we | |
6106 | -- skip this in the access case, because the access | |
6107 | -- value may be null, so we cannot know statically. | |
6108 | ||
6109 | if not Do_Access | |
6110 | and then Compile_Time_Known_Value (L_Low) | |
6111 | and then Compile_Time_Known_Value (L_High) | |
6112 | and then Compile_Time_Known_Value (R_Low) | |
6113 | and then Compile_Time_Known_Value (R_High) | |
6114 | then | |
6115 | if Expr_Value (L_High) >= Expr_Value (L_Low) then | |
6116 | L_Length := Expr_Value (L_High) - | |
6117 | Expr_Value (L_Low) + 1; | |
6118 | else | |
6119 | L_Length := UI_From_Int (0); | |
6120 | end if; | |
6121 | ||
6122 | if Expr_Value (R_High) >= Expr_Value (R_Low) then | |
6123 | R_Length := Expr_Value (R_High) - | |
6124 | Expr_Value (R_Low) + 1; | |
6125 | else | |
6126 | R_Length := UI_From_Int (0); | |
6127 | end if; | |
6128 | ||
6129 | if L_Length > R_Length then | |
6130 | Add_Check | |
6131 | (Compile_Time_Constraint_Error | |
6132 | (Wnode, "too few elements for}?", T_Typ)); | |
6133 | ||
6134 | elsif L_Length < R_Length then | |
6135 | Add_Check | |
6136 | (Compile_Time_Constraint_Error | |
6137 | (Wnode, "too many elements for}?", T_Typ)); | |
6138 | end if; | |
6139 | ||
6140 | -- The comparison for an individual index subtype | |
6141 | -- is omitted if the corresponding index subtypes | |
6142 | -- statically match, since the result is known to | |
6143 | -- be true. Note that this test is worth while even | |
6144 | -- though we do static evaluation, because non-static | |
6145 | -- subtypes can statically match. | |
6146 | ||
6147 | elsif not | |
6148 | Subtypes_Statically_Match | |
6149 | (Etype (L_Index), Etype (R_Index)) | |
6150 | ||
6151 | and then not | |
6152 | (Same_Bounds (L_Low, R_Low) | |
6153 | and then Same_Bounds (L_High, R_High)) | |
6154 | then | |
6155 | Evolve_Or_Else | |
6156 | (Cond, Length_E_Cond (Exptyp, T_Typ, Indx)); | |
6157 | end if; | |
6158 | ||
6159 | Next (L_Index); | |
6160 | Next (R_Index); | |
6161 | end if; | |
6162 | end loop; | |
6163 | end; | |
6164 | ||
6165 | -- Handle cases where we do not get a usable actual subtype that | |
6166 | -- is constrained. This happens for example in the function call | |
6167 | -- and explicit dereference cases. In these cases, we have to get | |
6168 | -- the length or range from the expression itself, making sure we | |
6169 | -- do not evaluate it more than once. | |
6170 | ||
6171 | -- Here Ck_Node is the original expression, or more properly the | |
feff2f05 | 6172 | -- result of applying Duplicate_Expr to the original tree, forcing |
6173 | -- the result to be a name. | |
ee6ba406 | 6174 | |
6175 | else | |
6176 | declare | |
9dfe12ae | 6177 | Ndims : constant Nat := Number_Dimensions (T_Typ); |
ee6ba406 | 6178 | |
6179 | begin | |
6180 | -- Build the condition for the explicit dereference case | |
6181 | ||
6182 | for Indx in 1 .. Ndims loop | |
6183 | Evolve_Or_Else | |
6184 | (Cond, Length_N_Cond (Ck_Node, T_Typ, Indx)); | |
6185 | end loop; | |
6186 | end; | |
6187 | end if; | |
6188 | end if; | |
6189 | end if; | |
6190 | ||
6191 | -- Construct the test and insert into the tree | |
6192 | ||
6193 | if Present (Cond) then | |
6194 | if Do_Access then | |
6195 | Cond := Guard_Access (Cond, Loc, Ck_Node); | |
6196 | end if; | |
6197 | ||
f15731c4 | 6198 | Add_Check |
6199 | (Make_Raise_Constraint_Error (Loc, | |
6200 | Condition => Cond, | |
6201 | Reason => CE_Length_Check_Failed)); | |
ee6ba406 | 6202 | end if; |
6203 | ||
6204 | return Ret_Result; | |
ee6ba406 | 6205 | end Selected_Length_Checks; |
6206 | ||
6207 | --------------------------- | |
6208 | -- Selected_Range_Checks -- | |
6209 | --------------------------- | |
6210 | ||
6211 | function Selected_Range_Checks | |
6212 | (Ck_Node : Node_Id; | |
6213 | Target_Typ : Entity_Id; | |
6214 | Source_Typ : Entity_Id; | |
314a23b6 | 6215 | Warn_Node : Node_Id) return Check_Result |
ee6ba406 | 6216 | is |
6217 | Loc : constant Source_Ptr := Sloc (Ck_Node); | |
6218 | S_Typ : Entity_Id; | |
6219 | T_Typ : Entity_Id; | |
6220 | Expr_Actual : Node_Id; | |
6221 | Exptyp : Entity_Id; | |
6222 | Cond : Node_Id := Empty; | |
6223 | Do_Access : Boolean := False; | |
6224 | Wnode : Node_Id := Warn_Node; | |
6225 | Ret_Result : Check_Result := (Empty, Empty); | |
6226 | Num_Checks : Integer := 0; | |
6227 | ||
6228 | procedure Add_Check (N : Node_Id); | |
6229 | -- Adds the action given to Ret_Result if N is non-Empty | |
6230 | ||
6231 | function Discrete_Range_Cond | |
6232 | (Expr : Node_Id; | |
314a23b6 | 6233 | Typ : Entity_Id) return Node_Id; |
ee6ba406 | 6234 | -- Returns expression to compute: |
6235 | -- Low_Bound (Expr) < Typ'First | |
6236 | -- or else | |
6237 | -- High_Bound (Expr) > Typ'Last | |
6238 | ||
6239 | function Discrete_Expr_Cond | |
6240 | (Expr : Node_Id; | |
314a23b6 | 6241 | Typ : Entity_Id) return Node_Id; |
ee6ba406 | 6242 | -- Returns expression to compute: |
6243 | -- Expr < Typ'First | |
6244 | -- or else | |
6245 | -- Expr > Typ'Last | |
6246 | ||
6247 | function Get_E_First_Or_Last | |
6248 | (E : Entity_Id; | |
6249 | Indx : Nat; | |
314a23b6 | 6250 | Nam : Name_Id) return Node_Id; |
ee6ba406 | 6251 | -- Returns expression to compute: |
6252 | -- E'First or E'Last | |
6253 | ||
6254 | function Get_N_First (N : Node_Id; Indx : Nat) return Node_Id; | |
6255 | function Get_N_Last (N : Node_Id; Indx : Nat) return Node_Id; | |
6256 | -- Returns expression to compute: | |
9dfe12ae | 6257 | -- N'First or N'Last using Duplicate_Subexpr_No_Checks |
ee6ba406 | 6258 | |
6259 | function Range_E_Cond | |
6260 | (Exptyp : Entity_Id; | |
6261 | Typ : Entity_Id; | |
6262 | Indx : Nat) | |
6263 | return Node_Id; | |
6264 | -- Returns expression to compute: | |
6265 | -- Exptyp'First < Typ'First or else Exptyp'Last > Typ'Last | |
6266 | ||
6267 | function Range_Equal_E_Cond | |
6268 | (Exptyp : Entity_Id; | |
6269 | Typ : Entity_Id; | |
314a23b6 | 6270 | Indx : Nat) return Node_Id; |
ee6ba406 | 6271 | -- Returns expression to compute: |
6272 | -- Exptyp'First /= Typ'First or else Exptyp'Last /= Typ'Last | |
6273 | ||
6274 | function Range_N_Cond | |
6275 | (Expr : Node_Id; | |
6276 | Typ : Entity_Id; | |
314a23b6 | 6277 | Indx : Nat) return Node_Id; |
ee6ba406 | 6278 | -- Return expression to compute: |
6279 | -- Expr'First < Typ'First or else Expr'Last > Typ'Last | |
6280 | ||
6281 | --------------- | |
6282 | -- Add_Check -- | |
6283 | --------------- | |
6284 | ||
6285 | procedure Add_Check (N : Node_Id) is | |
6286 | begin | |
6287 | if Present (N) then | |
6288 | ||
6289 | -- For now, ignore attempt to place more than 2 checks ??? | |
6290 | ||
6291 | if Num_Checks = 2 then | |
6292 | return; | |
6293 | end if; | |
6294 | ||
6295 | pragma Assert (Num_Checks <= 1); | |
6296 | Num_Checks := Num_Checks + 1; | |
6297 | Ret_Result (Num_Checks) := N; | |
6298 | end if; | |
6299 | end Add_Check; | |
6300 | ||
6301 | ------------------------- | |
6302 | -- Discrete_Expr_Cond -- | |
6303 | ------------------------- | |
6304 | ||
6305 | function Discrete_Expr_Cond | |
6306 | (Expr : Node_Id; | |
314a23b6 | 6307 | Typ : Entity_Id) return Node_Id |
ee6ba406 | 6308 | is |
6309 | begin | |
6310 | return | |
6311 | Make_Or_Else (Loc, | |
6312 | Left_Opnd => | |
6313 | Make_Op_Lt (Loc, | |
6314 | Left_Opnd => | |
9dfe12ae | 6315 | Convert_To (Base_Type (Typ), |
6316 | Duplicate_Subexpr_No_Checks (Expr)), | |
ee6ba406 | 6317 | Right_Opnd => |
6318 | Convert_To (Base_Type (Typ), | |
6319 | Get_E_First_Or_Last (Typ, 0, Name_First))), | |
6320 | ||
6321 | Right_Opnd => | |
6322 | Make_Op_Gt (Loc, | |
6323 | Left_Opnd => | |
9dfe12ae | 6324 | Convert_To (Base_Type (Typ), |
6325 | Duplicate_Subexpr_No_Checks (Expr)), | |
ee6ba406 | 6326 | Right_Opnd => |
6327 | Convert_To | |
6328 | (Base_Type (Typ), | |
6329 | Get_E_First_Or_Last (Typ, 0, Name_Last)))); | |
6330 | end Discrete_Expr_Cond; | |
6331 | ||
6332 | ------------------------- | |
6333 | -- Discrete_Range_Cond -- | |
6334 | ------------------------- | |
6335 | ||
6336 | function Discrete_Range_Cond | |
6337 | (Expr : Node_Id; | |
314a23b6 | 6338 | Typ : Entity_Id) return Node_Id |
ee6ba406 | 6339 | is |
6340 | LB : Node_Id := Low_Bound (Expr); | |
6341 | HB : Node_Id := High_Bound (Expr); | |
6342 | ||
6343 | Left_Opnd : Node_Id; | |
6344 | Right_Opnd : Node_Id; | |
6345 | ||
6346 | begin | |
6347 | if Nkind (LB) = N_Identifier | |
feff2f05 | 6348 | and then Ekind (Entity (LB)) = E_Discriminant |
6349 | then | |
ee6ba406 | 6350 | LB := New_Occurrence_Of (Discriminal (Entity (LB)), Loc); |
6351 | end if; | |
6352 | ||
6353 | if Nkind (HB) = N_Identifier | |
feff2f05 | 6354 | and then Ekind (Entity (HB)) = E_Discriminant |
6355 | then | |
ee6ba406 | 6356 | HB := New_Occurrence_Of (Discriminal (Entity (HB)), Loc); |
6357 | end if; | |
6358 | ||
6359 | Left_Opnd := | |
6360 | Make_Op_Lt (Loc, | |
6361 | Left_Opnd => | |
6362 | Convert_To | |
9dfe12ae | 6363 | (Base_Type (Typ), Duplicate_Subexpr_No_Checks (LB)), |
ee6ba406 | 6364 | |
6365 | Right_Opnd => | |
6366 | Convert_To | |
6367 | (Base_Type (Typ), Get_E_First_Or_Last (Typ, 0, Name_First))); | |
6368 | ||
6369 | if Base_Type (Typ) = Typ then | |
6370 | return Left_Opnd; | |
6371 | ||
6372 | elsif Compile_Time_Known_Value (High_Bound (Scalar_Range (Typ))) | |
6373 | and then | |
6374 | Compile_Time_Known_Value (High_Bound (Scalar_Range | |
6375 | (Base_Type (Typ)))) | |
6376 | then | |
6377 | if Is_Floating_Point_Type (Typ) then | |
6378 | if Expr_Value_R (High_Bound (Scalar_Range (Typ))) = | |
6379 | Expr_Value_R (High_Bound (Scalar_Range (Base_Type (Typ)))) | |
6380 | then | |
6381 | return Left_Opnd; | |
6382 | end if; | |
6383 | ||
6384 | else | |
6385 | if Expr_Value (High_Bound (Scalar_Range (Typ))) = | |
6386 | Expr_Value (High_Bound (Scalar_Range (Base_Type (Typ)))) | |
6387 | then | |
6388 | return Left_Opnd; | |
6389 | end if; | |
6390 | end if; | |
6391 | end if; | |
6392 | ||
6393 | Right_Opnd := | |
6394 | Make_Op_Gt (Loc, | |
6395 | Left_Opnd => | |
6396 | Convert_To | |
9dfe12ae | 6397 | (Base_Type (Typ), Duplicate_Subexpr_No_Checks (HB)), |
ee6ba406 | 6398 | |
6399 | Right_Opnd => | |
6400 | Convert_To | |
6401 | (Base_Type (Typ), | |
6402 | Get_E_First_Or_Last (Typ, 0, Name_Last))); | |
6403 | ||
6404 | return Make_Or_Else (Loc, Left_Opnd, Right_Opnd); | |
6405 | end Discrete_Range_Cond; | |
6406 | ||
6407 | ------------------------- | |
6408 | -- Get_E_First_Or_Last -- | |
6409 | ------------------------- | |
6410 | ||
6411 | function Get_E_First_Or_Last | |
6412 | (E : Entity_Id; | |
6413 | Indx : Nat; | |
314a23b6 | 6414 | Nam : Name_Id) return Node_Id |
ee6ba406 | 6415 | is |
6416 | N : Node_Id; | |
6417 | LB : Node_Id; | |
6418 | HB : Node_Id; | |
6419 | Bound : Node_Id; | |
6420 | ||
6421 | begin | |
6422 | if Is_Array_Type (E) then | |
6423 | N := First_Index (E); | |
6424 | ||
6425 | for J in 2 .. Indx loop | |
6426 | Next_Index (N); | |
6427 | end loop; | |
6428 | ||
6429 | else | |
6430 | N := Scalar_Range (E); | |
6431 | end if; | |
6432 | ||
6433 | if Nkind (N) = N_Subtype_Indication then | |
6434 | LB := Low_Bound (Range_Expression (Constraint (N))); | |
6435 | HB := High_Bound (Range_Expression (Constraint (N))); | |
6436 | ||
6437 | elsif Is_Entity_Name (N) then | |
6438 | LB := Type_Low_Bound (Etype (N)); | |
6439 | HB := Type_High_Bound (Etype (N)); | |
6440 | ||
6441 | else | |
6442 | LB := Low_Bound (N); | |
6443 | HB := High_Bound (N); | |
6444 | end if; | |
6445 | ||
6446 | if Nam = Name_First then | |
6447 | Bound := LB; | |
6448 | else | |
6449 | Bound := HB; | |
6450 | end if; | |
6451 | ||
6452 | if Nkind (Bound) = N_Identifier | |
6453 | and then Ekind (Entity (Bound)) = E_Discriminant | |
6454 | then | |
9dfe12ae | 6455 | -- If this is a task discriminant, and we are the body, we must |
6456 | -- retrieve the corresponding body discriminal. This is another | |
6457 | -- consequence of the early creation of discriminals, and the | |
6458 | -- need to generate constraint checks before their declarations | |
6459 | -- are made visible. | |
6460 | ||
6461 | if Is_Concurrent_Record_Type (Scope (Entity (Bound))) then | |
6462 | declare | |
6463 | Tsk : constant Entity_Id := | |
6464 | Corresponding_Concurrent_Type | |
6465 | (Scope (Entity (Bound))); | |
6466 | Disc : Entity_Id; | |
6467 | ||
6468 | begin | |
6469 | if In_Open_Scopes (Tsk) | |
6470 | and then Has_Completion (Tsk) | |
6471 | then | |
6472 | -- Find discriminant of original task, and use its | |
6473 | -- current discriminal, which is the renaming within | |
6474 | -- the task body. | |
6475 | ||
6476 | Disc := First_Discriminant (Tsk); | |
6477 | while Present (Disc) loop | |
6478 | if Chars (Disc) = Chars (Entity (Bound)) then | |
6479 | Set_Scope (Discriminal (Disc), Tsk); | |
6480 | return New_Occurrence_Of (Discriminal (Disc), Loc); | |
6481 | end if; | |
6482 | ||
6483 | Next_Discriminant (Disc); | |
6484 | end loop; | |
6485 | ||
6486 | -- That loop should always succeed in finding a matching | |
6487 | -- entry and returning. Fatal error if not. | |
6488 | ||
6489 | raise Program_Error; | |
6490 | ||
6491 | else | |
6492 | return | |
6493 | New_Occurrence_Of (Discriminal (Entity (Bound)), Loc); | |
6494 | end if; | |
6495 | end; | |
6496 | else | |
6497 | return New_Occurrence_Of (Discriminal (Entity (Bound)), Loc); | |
6498 | end if; | |
ee6ba406 | 6499 | |
6500 | elsif Nkind (Bound) = N_Identifier | |
6501 | and then Ekind (Entity (Bound)) = E_In_Parameter | |
6502 | and then not Inside_Init_Proc | |
6503 | then | |
6504 | return Get_Discriminal (E, Bound); | |
6505 | ||
6506 | elsif Nkind (Bound) = N_Integer_Literal then | |
18563cef | 6507 | return Make_Integer_Literal (Loc, Intval (Bound)); |
6508 | ||
feff2f05 | 6509 | -- Case of a bound rewritten to an N_Raise_Constraint_Error node |
6510 | -- because it is an out-of-range value. Duplicate_Subexpr cannot be | |
6511 | -- called on this node because an N_Raise_Constraint_Error is not | |
6512 | -- side effect free, and we may not assume that we are in the proper | |
6513 | -- context to remove side effects on it at the point of reference. | |
18563cef | 6514 | |
6515 | elsif Nkind (Bound) = N_Raise_Constraint_Error then | |
6516 | return New_Copy_Tree (Bound); | |
ee6ba406 | 6517 | |
6518 | else | |
9dfe12ae | 6519 | return Duplicate_Subexpr_No_Checks (Bound); |
ee6ba406 | 6520 | end if; |
6521 | end Get_E_First_Or_Last; | |
6522 | ||
6523 | ----------------- | |
6524 | -- Get_N_First -- | |
6525 | ----------------- | |
6526 | ||
6527 | function Get_N_First (N : Node_Id; Indx : Nat) return Node_Id is | |
6528 | begin | |
6529 | return | |
6530 | Make_Attribute_Reference (Loc, | |
6531 | Attribute_Name => Name_First, | |
6532 | Prefix => | |
9dfe12ae | 6533 | Duplicate_Subexpr_No_Checks (N, Name_Req => True), |
ee6ba406 | 6534 | Expressions => New_List ( |
6535 | Make_Integer_Literal (Loc, Indx))); | |
ee6ba406 | 6536 | end Get_N_First; |
6537 | ||
6538 | ---------------- | |
6539 | -- Get_N_Last -- | |
6540 | ---------------- | |
6541 | ||
6542 | function Get_N_Last (N : Node_Id; Indx : Nat) return Node_Id is | |
6543 | begin | |
6544 | return | |
6545 | Make_Attribute_Reference (Loc, | |
6546 | Attribute_Name => Name_Last, | |
6547 | Prefix => | |
9dfe12ae | 6548 | Duplicate_Subexpr_No_Checks (N, Name_Req => True), |
ee6ba406 | 6549 | Expressions => New_List ( |
6550 | Make_Integer_Literal (Loc, Indx))); | |
ee6ba406 | 6551 | end Get_N_Last; |
6552 | ||
6553 | ------------------ | |
6554 | -- Range_E_Cond -- | |
6555 | ------------------ | |
6556 | ||
6557 | function Range_E_Cond | |
6558 | (Exptyp : Entity_Id; | |
6559 | Typ : Entity_Id; | |
314a23b6 | 6560 | Indx : Nat) return Node_Id |
ee6ba406 | 6561 | is |
6562 | begin | |
6563 | return | |
6564 | Make_Or_Else (Loc, | |
6565 | Left_Opnd => | |
6566 | Make_Op_Lt (Loc, | |
6567 | Left_Opnd => Get_E_First_Or_Last (Exptyp, Indx, Name_First), | |
6568 | Right_Opnd => Get_E_First_Or_Last (Typ, Indx, Name_First)), | |
6569 | ||
6570 | Right_Opnd => | |
6571 | Make_Op_Gt (Loc, | |
6572 | Left_Opnd => Get_E_First_Or_Last (Exptyp, Indx, Name_Last), | |
6573 | Right_Opnd => Get_E_First_Or_Last (Typ, Indx, Name_Last))); | |
ee6ba406 | 6574 | end Range_E_Cond; |
6575 | ||
6576 | ------------------------ | |
6577 | -- Range_Equal_E_Cond -- | |
6578 | ------------------------ | |
6579 | ||
6580 | function Range_Equal_E_Cond | |
6581 | (Exptyp : Entity_Id; | |
6582 | Typ : Entity_Id; | |
314a23b6 | 6583 | Indx : Nat) return Node_Id |
ee6ba406 | 6584 | is |
6585 | begin | |
6586 | return | |
6587 | Make_Or_Else (Loc, | |
6588 | Left_Opnd => | |
6589 | Make_Op_Ne (Loc, | |
6590 | Left_Opnd => Get_E_First_Or_Last (Exptyp, Indx, Name_First), | |
6591 | Right_Opnd => Get_E_First_Or_Last (Typ, Indx, Name_First)), | |
6592 | Right_Opnd => | |
6593 | Make_Op_Ne (Loc, | |
6594 | Left_Opnd => Get_E_First_Or_Last (Exptyp, Indx, Name_Last), | |
6595 | Right_Opnd => Get_E_First_Or_Last (Typ, Indx, Name_Last))); | |
6596 | end Range_Equal_E_Cond; | |
6597 | ||
6598 | ------------------ | |
6599 | -- Range_N_Cond -- | |
6600 | ------------------ | |
6601 | ||
6602 | function Range_N_Cond | |
6603 | (Expr : Node_Id; | |
6604 | Typ : Entity_Id; | |
314a23b6 | 6605 | Indx : Nat) return Node_Id |
ee6ba406 | 6606 | is |
6607 | begin | |
6608 | return | |
6609 | Make_Or_Else (Loc, | |
6610 | Left_Opnd => | |
6611 | Make_Op_Lt (Loc, | |
6612 | Left_Opnd => Get_N_First (Expr, Indx), | |
6613 | Right_Opnd => Get_E_First_Or_Last (Typ, Indx, Name_First)), | |
6614 | ||
6615 | Right_Opnd => | |
6616 | Make_Op_Gt (Loc, | |
6617 | Left_Opnd => Get_N_Last (Expr, Indx), | |
6618 | Right_Opnd => Get_E_First_Or_Last (Typ, Indx, Name_Last))); | |
6619 | end Range_N_Cond; | |
6620 | ||
6621 | -- Start of processing for Selected_Range_Checks | |
6622 | ||
6623 | begin | |
6624 | if not Expander_Active then | |
6625 | return Ret_Result; | |
6626 | end if; | |
6627 | ||
6628 | if Target_Typ = Any_Type | |
6629 | or else Target_Typ = Any_Composite | |
6630 | or else Raises_Constraint_Error (Ck_Node) | |
6631 | then | |
6632 | return Ret_Result; | |
6633 | end if; | |
6634 | ||
6635 | if No (Wnode) then | |
6636 | Wnode := Ck_Node; | |
6637 | end if; | |
6638 | ||
6639 | T_Typ := Target_Typ; | |
6640 | ||
6641 | if No (Source_Typ) then | |
6642 | S_Typ := Etype (Ck_Node); | |
6643 | else | |
6644 | S_Typ := Source_Typ; | |
6645 | end if; | |
6646 | ||
6647 | if S_Typ = Any_Type or else S_Typ = Any_Composite then | |
6648 | return Ret_Result; | |
6649 | end if; | |
6650 | ||
6651 | -- The order of evaluating T_Typ before S_Typ seems to be critical | |
6652 | -- because S_Typ can be derived from Etype (Ck_Node), if it's not passed | |
6653 | -- in, and since Node can be an N_Range node, it might be invalid. | |
6654 | -- Should there be an assert check somewhere for taking the Etype of | |
6655 | -- an N_Range node ??? | |
6656 | ||
6657 | if Is_Access_Type (T_Typ) and then Is_Access_Type (S_Typ) then | |
6658 | S_Typ := Designated_Type (S_Typ); | |
6659 | T_Typ := Designated_Type (T_Typ); | |
6660 | Do_Access := True; | |
6661 | ||
2af58f67 | 6662 | -- A simple optimization for the null case |
ee6ba406 | 6663 | |
2af58f67 | 6664 | if Known_Null (Ck_Node) then |
ee6ba406 | 6665 | return Ret_Result; |
6666 | end if; | |
6667 | end if; | |
6668 | ||
6669 | -- For an N_Range Node, check for a null range and then if not | |
6670 | -- null generate a range check action. | |
6671 | ||
6672 | if Nkind (Ck_Node) = N_Range then | |
6673 | ||
6674 | -- There's no point in checking a range against itself | |
6675 | ||
6676 | if Ck_Node = Scalar_Range (T_Typ) then | |
6677 | return Ret_Result; | |
6678 | end if; | |
6679 | ||
6680 | declare | |
6681 | T_LB : constant Node_Id := Type_Low_Bound (T_Typ); | |
6682 | T_HB : constant Node_Id := Type_High_Bound (T_Typ); | |
6683 | LB : constant Node_Id := Low_Bound (Ck_Node); | |
6684 | HB : constant Node_Id := High_Bound (Ck_Node); | |
6685 | Null_Range : Boolean; | |
6686 | ||
6687 | Out_Of_Range_L : Boolean; | |
6688 | Out_Of_Range_H : Boolean; | |
6689 | ||
6690 | begin | |
6691 | -- Check for case where everything is static and we can | |
6692 | -- do the check at compile time. This is skipped if we | |
6693 | -- have an access type, since the access value may be null. | |
6694 | ||
6695 | -- ??? This code can be improved since you only need to know | |
6696 | -- that the two respective bounds (LB & T_LB or HB & T_HB) | |
6697 | -- are known at compile time to emit pertinent messages. | |
6698 | ||
6699 | if Compile_Time_Known_Value (LB) | |
6700 | and then Compile_Time_Known_Value (HB) | |
6701 | and then Compile_Time_Known_Value (T_LB) | |
6702 | and then Compile_Time_Known_Value (T_HB) | |
6703 | and then not Do_Access | |
6704 | then | |
6705 | -- Floating-point case | |
6706 | ||
6707 | if Is_Floating_Point_Type (S_Typ) then | |
6708 | Null_Range := Expr_Value_R (HB) < Expr_Value_R (LB); | |
6709 | Out_Of_Range_L := | |
6710 | (Expr_Value_R (LB) < Expr_Value_R (T_LB)) | |
6711 | or else | |
6712 | (Expr_Value_R (LB) > Expr_Value_R (T_HB)); | |
6713 | ||
6714 | Out_Of_Range_H := | |
6715 | (Expr_Value_R (HB) > Expr_Value_R (T_HB)) | |
6716 | or else | |
6717 | (Expr_Value_R (HB) < Expr_Value_R (T_LB)); | |
6718 | ||
6719 | -- Fixed or discrete type case | |
6720 | ||
6721 | else | |
6722 | Null_Range := Expr_Value (HB) < Expr_Value (LB); | |
6723 | Out_Of_Range_L := | |
6724 | (Expr_Value (LB) < Expr_Value (T_LB)) | |
6725 | or else | |
6726 | (Expr_Value (LB) > Expr_Value (T_HB)); | |
6727 | ||
6728 | Out_Of_Range_H := | |
6729 | (Expr_Value (HB) > Expr_Value (T_HB)) | |
6730 | or else | |
6731 | (Expr_Value (HB) < Expr_Value (T_LB)); | |
6732 | end if; | |
6733 | ||
6734 | if not Null_Range then | |
6735 | if Out_Of_Range_L then | |
6736 | if No (Warn_Node) then | |
6737 | Add_Check | |
6738 | (Compile_Time_Constraint_Error | |
6739 | (Low_Bound (Ck_Node), | |
6740 | "static value out of range of}?", T_Typ)); | |
6741 | ||
6742 | else | |
6743 | Add_Check | |
6744 | (Compile_Time_Constraint_Error | |
6745 | (Wnode, | |
6746 | "static range out of bounds of}?", T_Typ)); | |
6747 | end if; | |
6748 | end if; | |
6749 | ||
6750 | if Out_Of_Range_H then | |
6751 | if No (Warn_Node) then | |
6752 | Add_Check | |
6753 | (Compile_Time_Constraint_Error | |
6754 | (High_Bound (Ck_Node), | |
6755 | "static value out of range of}?", T_Typ)); | |
6756 | ||
6757 | else | |
6758 | Add_Check | |
6759 | (Compile_Time_Constraint_Error | |
6760 | (Wnode, | |
6761 | "static range out of bounds of}?", T_Typ)); | |
6762 | end if; | |
6763 | end if; | |
6764 | ||
6765 | end if; | |
6766 | ||
6767 | else | |
6768 | declare | |
6769 | LB : Node_Id := Low_Bound (Ck_Node); | |
6770 | HB : Node_Id := High_Bound (Ck_Node); | |
6771 | ||
6772 | begin | |
feff2f05 | 6773 | -- If either bound is a discriminant and we are within the |
6774 | -- record declaration, it is a use of the discriminant in a | |
6775 | -- constraint of a component, and nothing can be checked | |
6776 | -- here. The check will be emitted within the init proc. | |
6777 | -- Before then, the discriminal has no real meaning. | |
6778 | -- Similarly, if the entity is a discriminal, there is no | |
6779 | -- check to perform yet. | |
6780 | ||
6781 | -- The same holds within a discriminated synchronized type, | |
6782 | -- where the discriminant may constrain a component or an | |
6783 | -- entry family. | |
ee6ba406 | 6784 | |
6785 | if Nkind (LB) = N_Identifier | |
0577b0b1 | 6786 | and then Denotes_Discriminant (LB, True) |
ee6ba406 | 6787 | then |
0577b0b1 | 6788 | if Current_Scope = Scope (Entity (LB)) |
6789 | or else Is_Concurrent_Type (Current_Scope) | |
6790 | or else Ekind (Entity (LB)) /= E_Discriminant | |
6791 | then | |
ee6ba406 | 6792 | return Ret_Result; |
6793 | else | |
6794 | LB := | |
6795 | New_Occurrence_Of (Discriminal (Entity (LB)), Loc); | |
6796 | end if; | |
6797 | end if; | |
6798 | ||
6799 | if Nkind (HB) = N_Identifier | |
0577b0b1 | 6800 | and then Denotes_Discriminant (HB, True) |
ee6ba406 | 6801 | then |
0577b0b1 | 6802 | if Current_Scope = Scope (Entity (HB)) |
6803 | or else Is_Concurrent_Type (Current_Scope) | |
6804 | or else Ekind (Entity (HB)) /= E_Discriminant | |
6805 | then | |
ee6ba406 | 6806 | return Ret_Result; |
6807 | else | |
6808 | HB := | |
6809 | New_Occurrence_Of (Discriminal (Entity (HB)), Loc); | |
6810 | end if; | |
6811 | end if; | |
6812 | ||
6813 | Cond := Discrete_Range_Cond (Ck_Node, T_Typ); | |
6814 | Set_Paren_Count (Cond, 1); | |
6815 | ||
6816 | Cond := | |
6817 | Make_And_Then (Loc, | |
6818 | Left_Opnd => | |
6819 | Make_Op_Ge (Loc, | |
9dfe12ae | 6820 | Left_Opnd => Duplicate_Subexpr_No_Checks (HB), |
6821 | Right_Opnd => Duplicate_Subexpr_No_Checks (LB)), | |
ee6ba406 | 6822 | Right_Opnd => Cond); |
6823 | end; | |
ee6ba406 | 6824 | end if; |
6825 | end; | |
6826 | ||
6827 | elsif Is_Scalar_Type (S_Typ) then | |
6828 | ||
6829 | -- This somewhat duplicates what Apply_Scalar_Range_Check does, | |
6830 | -- except the above simply sets a flag in the node and lets | |
6831 | -- gigi generate the check base on the Etype of the expression. | |
6832 | -- Sometimes, however we want to do a dynamic check against an | |
6833 | -- arbitrary target type, so we do that here. | |
6834 | ||
6835 | if Ekind (Base_Type (S_Typ)) /= Ekind (Base_Type (T_Typ)) then | |
6836 | Cond := Discrete_Expr_Cond (Ck_Node, T_Typ); | |
6837 | ||
6838 | -- For literals, we can tell if the constraint error will be | |
6839 | -- raised at compile time, so we never need a dynamic check, but | |
6840 | -- if the exception will be raised, then post the usual warning, | |
6841 | -- and replace the literal with a raise constraint error | |
6842 | -- expression. As usual, skip this for access types | |
6843 | ||
6844 | elsif Compile_Time_Known_Value (Ck_Node) | |
6845 | and then not Do_Access | |
6846 | then | |
6847 | declare | |
6848 | LB : constant Node_Id := Type_Low_Bound (T_Typ); | |
6849 | UB : constant Node_Id := Type_High_Bound (T_Typ); | |
6850 | ||
6851 | Out_Of_Range : Boolean; | |
6852 | Static_Bounds : constant Boolean := | |
6853 | Compile_Time_Known_Value (LB) | |
6854 | and Compile_Time_Known_Value (UB); | |
6855 | ||
6856 | begin | |
6857 | -- Following range tests should use Sem_Eval routine ??? | |
6858 | ||
6859 | if Static_Bounds then | |
6860 | if Is_Floating_Point_Type (S_Typ) then | |
6861 | Out_Of_Range := | |
6862 | (Expr_Value_R (Ck_Node) < Expr_Value_R (LB)) | |
6863 | or else | |
6864 | (Expr_Value_R (Ck_Node) > Expr_Value_R (UB)); | |
6865 | ||
6866 | else -- fixed or discrete type | |
6867 | Out_Of_Range := | |
6868 | Expr_Value (Ck_Node) < Expr_Value (LB) | |
6869 | or else | |
6870 | Expr_Value (Ck_Node) > Expr_Value (UB); | |
6871 | end if; | |
6872 | ||
6873 | -- Bounds of the type are static and the literal is | |
6874 | -- out of range so make a warning message. | |
6875 | ||
6876 | if Out_Of_Range then | |
6877 | if No (Warn_Node) then | |
6878 | Add_Check | |
6879 | (Compile_Time_Constraint_Error | |
6880 | (Ck_Node, | |
6881 | "static value out of range of}?", T_Typ)); | |
6882 | ||
6883 | else | |
6884 | Add_Check | |
6885 | (Compile_Time_Constraint_Error | |
6886 | (Wnode, | |
6887 | "static value out of range of}?", T_Typ)); | |
6888 | end if; | |
6889 | end if; | |
6890 | ||
6891 | else | |
6892 | Cond := Discrete_Expr_Cond (Ck_Node, T_Typ); | |
6893 | end if; | |
6894 | end; | |
6895 | ||
6896 | -- Here for the case of a non-static expression, we need a runtime | |
6897 | -- check unless the source type range is guaranteed to be in the | |
6898 | -- range of the target type. | |
6899 | ||
6900 | else | |
7a1dabb3 | 6901 | if not In_Subrange_Of (S_Typ, T_Typ) then |
ee6ba406 | 6902 | Cond := Discrete_Expr_Cond (Ck_Node, T_Typ); |
6903 | end if; | |
6904 | end if; | |
6905 | end if; | |
6906 | ||
6907 | if Is_Array_Type (T_Typ) and then Is_Array_Type (S_Typ) then | |
6908 | if Is_Constrained (T_Typ) then | |
6909 | ||
6910 | Expr_Actual := Get_Referenced_Object (Ck_Node); | |
6911 | Exptyp := Get_Actual_Subtype (Expr_Actual); | |
6912 | ||
6913 | if Is_Access_Type (Exptyp) then | |
6914 | Exptyp := Designated_Type (Exptyp); | |
6915 | end if; | |
6916 | ||
6917 | -- String_Literal case. This needs to be handled specially be- | |
6918 | -- cause no index types are available for string literals. The | |
6919 | -- condition is simply: | |
6920 | ||
6921 | -- T_Typ'Length = string-literal-length | |
6922 | ||
6923 | if Nkind (Expr_Actual) = N_String_Literal then | |
6924 | null; | |
6925 | ||
6926 | -- General array case. Here we have a usable actual subtype for | |
6927 | -- the expression, and the condition is built from the two types | |
6928 | ||
6929 | -- T_Typ'First < Exptyp'First or else | |
6930 | -- T_Typ'Last > Exptyp'Last or else | |
6931 | -- T_Typ'First(1) < Exptyp'First(1) or else | |
6932 | -- T_Typ'Last(1) > Exptyp'Last(1) or else | |
6933 | -- ... | |
6934 | ||
6935 | elsif Is_Constrained (Exptyp) then | |
6936 | declare | |
9dfe12ae | 6937 | Ndims : constant Nat := Number_Dimensions (T_Typ); |
6938 | ||
ee6ba406 | 6939 | L_Index : Node_Id; |
6940 | R_Index : Node_Id; | |
ee6ba406 | 6941 | |
6942 | begin | |
6943 | L_Index := First_Index (T_Typ); | |
6944 | R_Index := First_Index (Exptyp); | |
6945 | ||
6946 | for Indx in 1 .. Ndims loop | |
6947 | if not (Nkind (L_Index) = N_Raise_Constraint_Error | |
f15731c4 | 6948 | or else |
6949 | Nkind (R_Index) = N_Raise_Constraint_Error) | |
ee6ba406 | 6950 | then |
ee6ba406 | 6951 | -- Deal with compile time length check. Note that we |
6952 | -- skip this in the access case, because the access | |
6953 | -- value may be null, so we cannot know statically. | |
6954 | ||
6955 | if not | |
6956 | Subtypes_Statically_Match | |
6957 | (Etype (L_Index), Etype (R_Index)) | |
6958 | then | |
6959 | -- If the target type is constrained then we | |
6960 | -- have to check for exact equality of bounds | |
6961 | -- (required for qualified expressions). | |
6962 | ||
6963 | if Is_Constrained (T_Typ) then | |
6964 | Evolve_Or_Else | |
6965 | (Cond, | |
6966 | Range_Equal_E_Cond (Exptyp, T_Typ, Indx)); | |
ee6ba406 | 6967 | else |
6968 | Evolve_Or_Else | |
6969 | (Cond, Range_E_Cond (Exptyp, T_Typ, Indx)); | |
6970 | end if; | |
6971 | end if; | |
6972 | ||
6973 | Next (L_Index); | |
6974 | Next (R_Index); | |
6975 | ||
6976 | end if; | |
6977 | end loop; | |
6978 | end; | |
6979 | ||
6980 | -- Handle cases where we do not get a usable actual subtype that | |
6981 | -- is constrained. This happens for example in the function call | |
6982 | -- and explicit dereference cases. In these cases, we have to get | |
6983 | -- the length or range from the expression itself, making sure we | |
6984 | -- do not evaluate it more than once. | |
6985 | ||
6986 | -- Here Ck_Node is the original expression, or more properly the | |
6987 | -- result of applying Duplicate_Expr to the original tree, | |
6988 | -- forcing the result to be a name. | |
6989 | ||
6990 | else | |
6991 | declare | |
9dfe12ae | 6992 | Ndims : constant Nat := Number_Dimensions (T_Typ); |
ee6ba406 | 6993 | |
6994 | begin | |
6995 | -- Build the condition for the explicit dereference case | |
6996 | ||
6997 | for Indx in 1 .. Ndims loop | |
6998 | Evolve_Or_Else | |
6999 | (Cond, Range_N_Cond (Ck_Node, T_Typ, Indx)); | |
7000 | end loop; | |
7001 | end; | |
7002 | ||
7003 | end if; | |
7004 | ||
7005 | else | |
feff2f05 | 7006 | -- For a conversion to an unconstrained array type, generate an |
7007 | -- Action to check that the bounds of the source value are within | |
7008 | -- the constraints imposed by the target type (RM 4.6(38)). No | |
7009 | -- check is needed for a conversion to an access to unconstrained | |
7010 | -- array type, as 4.6(24.15/2) requires the designated subtypes | |
7011 | -- of the two access types to statically match. | |
7012 | ||
7013 | if Nkind (Parent (Ck_Node)) = N_Type_Conversion | |
7014 | and then not Do_Access | |
7015 | then | |
ee6ba406 | 7016 | declare |
7017 | Opnd_Index : Node_Id; | |
7018 | Targ_Index : Node_Id; | |
00c403ee | 7019 | Opnd_Range : Node_Id; |
ee6ba406 | 7020 | |
7021 | begin | |
feff2f05 | 7022 | Opnd_Index := First_Index (Get_Actual_Subtype (Ck_Node)); |
ee6ba406 | 7023 | Targ_Index := First_Index (T_Typ); |
00c403ee | 7024 | while Present (Opnd_Index) loop |
7025 | ||
7026 | -- If the index is a range, use its bounds. If it is an | |
7027 | -- entity (as will be the case if it is a named subtype | |
7028 | -- or an itype created for a slice) retrieve its range. | |
7029 | ||
7030 | if Is_Entity_Name (Opnd_Index) | |
7031 | and then Is_Type (Entity (Opnd_Index)) | |
7032 | then | |
7033 | Opnd_Range := Scalar_Range (Entity (Opnd_Index)); | |
7034 | else | |
7035 | Opnd_Range := Opnd_Index; | |
7036 | end if; | |
7037 | ||
7038 | if Nkind (Opnd_Range) = N_Range then | |
9c486805 | 7039 | if Is_In_Range |
7040 | (Low_Bound (Opnd_Range), Etype (Targ_Index), | |
7041 | Assume_Valid => True) | |
ee6ba406 | 7042 | and then |
7043 | Is_In_Range | |
9c486805 | 7044 | (High_Bound (Opnd_Range), Etype (Targ_Index), |
7045 | Assume_Valid => True) | |
ee6ba406 | 7046 | then |
7047 | null; | |
7048 | ||
feff2f05 | 7049 | -- If null range, no check needed |
f2a06be9 | 7050 | |
9dfe12ae | 7051 | elsif |
00c403ee | 7052 | Compile_Time_Known_Value (High_Bound (Opnd_Range)) |
9dfe12ae | 7053 | and then |
00c403ee | 7054 | Compile_Time_Known_Value (Low_Bound (Opnd_Range)) |
9dfe12ae | 7055 | and then |
00c403ee | 7056 | Expr_Value (High_Bound (Opnd_Range)) < |
7057 | Expr_Value (Low_Bound (Opnd_Range)) | |
9dfe12ae | 7058 | then |
7059 | null; | |
7060 | ||
ee6ba406 | 7061 | elsif Is_Out_Of_Range |
9c486805 | 7062 | (Low_Bound (Opnd_Range), Etype (Targ_Index), |
7063 | Assume_Valid => True) | |
ee6ba406 | 7064 | or else |
7065 | Is_Out_Of_Range | |
9c486805 | 7066 | (High_Bound (Opnd_Range), Etype (Targ_Index), |
7067 | Assume_Valid => True) | |
ee6ba406 | 7068 | then |
7069 | Add_Check | |
7070 | (Compile_Time_Constraint_Error | |
7071 | (Wnode, "value out of range of}?", T_Typ)); | |
7072 | ||
7073 | else | |
7074 | Evolve_Or_Else | |
7075 | (Cond, | |
7076 | Discrete_Range_Cond | |
00c403ee | 7077 | (Opnd_Range, Etype (Targ_Index))); |
ee6ba406 | 7078 | end if; |
7079 | end if; | |
7080 | ||
7081 | Next_Index (Opnd_Index); | |
7082 | Next_Index (Targ_Index); | |
7083 | end loop; | |
7084 | end; | |
7085 | end if; | |
7086 | end if; | |
7087 | end if; | |
7088 | ||
7089 | -- Construct the test and insert into the tree | |
7090 | ||
7091 | if Present (Cond) then | |
7092 | if Do_Access then | |
7093 | Cond := Guard_Access (Cond, Loc, Ck_Node); | |
7094 | end if; | |
7095 | ||
f15731c4 | 7096 | Add_Check |
7097 | (Make_Raise_Constraint_Error (Loc, | |
7098 | Condition => Cond, | |
7099 | Reason => CE_Range_Check_Failed)); | |
ee6ba406 | 7100 | end if; |
7101 | ||
7102 | return Ret_Result; | |
ee6ba406 | 7103 | end Selected_Range_Checks; |
7104 | ||
7105 | ------------------------------- | |
7106 | -- Storage_Checks_Suppressed -- | |
7107 | ------------------------------- | |
7108 | ||
7109 | function Storage_Checks_Suppressed (E : Entity_Id) return Boolean is | |
7110 | begin | |
9dfe12ae | 7111 | if Present (E) and then Checks_May_Be_Suppressed (E) then |
7112 | return Is_Check_Suppressed (E, Storage_Check); | |
7113 | else | |
7114 | return Scope_Suppress (Storage_Check); | |
7115 | end if; | |
ee6ba406 | 7116 | end Storage_Checks_Suppressed; |
7117 | ||
7118 | --------------------------- | |
7119 | -- Tag_Checks_Suppressed -- | |
7120 | --------------------------- | |
7121 | ||
7122 | function Tag_Checks_Suppressed (E : Entity_Id) return Boolean is | |
7123 | begin | |
9dfe12ae | 7124 | if Present (E) then |
7125 | if Kill_Tag_Checks (E) then | |
7126 | return True; | |
7127 | elsif Checks_May_Be_Suppressed (E) then | |
7128 | return Is_Check_Suppressed (E, Tag_Check); | |
7129 | end if; | |
7130 | end if; | |
7131 | ||
7132 | return Scope_Suppress (Tag_Check); | |
ee6ba406 | 7133 | end Tag_Checks_Suppressed; |
7134 | ||
0577b0b1 | 7135 | -------------------------- |
7136 | -- Validity_Check_Range -- | |
7137 | -------------------------- | |
7138 | ||
7139 | procedure Validity_Check_Range (N : Node_Id) is | |
7140 | begin | |
7141 | if Validity_Checks_On and Validity_Check_Operands then | |
7142 | if Nkind (N) = N_Range then | |
7143 | Ensure_Valid (Low_Bound (N)); | |
7144 | Ensure_Valid (High_Bound (N)); | |
7145 | end if; | |
7146 | end if; | |
7147 | end Validity_Check_Range; | |
7148 | ||
7149 | -------------------------------- | |
7150 | -- Validity_Checks_Suppressed -- | |
7151 | -------------------------------- | |
7152 | ||
7153 | function Validity_Checks_Suppressed (E : Entity_Id) return Boolean is | |
7154 | begin | |
7155 | if Present (E) and then Checks_May_Be_Suppressed (E) then | |
7156 | return Is_Check_Suppressed (E, Validity_Check); | |
7157 | else | |
7158 | return Scope_Suppress (Validity_Check); | |
7159 | end if; | |
7160 | end Validity_Checks_Suppressed; | |
7161 | ||
ee6ba406 | 7162 | end Checks; |