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fbf5a39b | 1 | ------------------------------------------------------------------------------ |
996ae0b0 RK |
2 | -- -- |
3 | -- GNAT COMPILER COMPONENTS -- | |
4 | -- -- | |
5 | -- S E M _ E V A L -- | |
6 | -- -- | |
7 | -- B o d y -- | |
8 | -- -- | |
93c3fca7 | 9 | -- Copyright (C) 1992-2009, Free Software Foundation, Inc. -- |
996ae0b0 RK |
10 | -- -- |
11 | -- GNAT is free software; you can redistribute it and/or modify it under -- | |
12 | -- terms of the GNU General Public License as published by the Free Soft- -- | |
b5c84c3c | 13 | -- ware Foundation; either version 3, or (at your option) any later ver- -- |
996ae0b0 RK |
14 | -- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- |
15 | -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- | |
16 | -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -- | |
17 | -- for more details. You should have received a copy of the GNU General -- | |
b5c84c3c RD |
18 | -- Public License distributed with GNAT; see file COPYING3. If not, go to -- |
19 | -- http://www.gnu.org/licenses for a complete copy of the license. -- | |
996ae0b0 RK |
20 | -- -- |
21 | -- GNAT was originally developed by the GNAT team at New York University. -- | |
71ff80dc | 22 | -- Extensive contributions were provided by Ada Core Technologies Inc. -- |
996ae0b0 RK |
23 | -- -- |
24 | ------------------------------------------------------------------------------ | |
25 | ||
26 | with Atree; use Atree; | |
27 | with Checks; use Checks; | |
28 | with Debug; use Debug; | |
29 | with Einfo; use Einfo; | |
30 | with Elists; use Elists; | |
31 | with Errout; use Errout; | |
32 | with Eval_Fat; use Eval_Fat; | |
8cbb664e | 33 | with Exp_Util; use Exp_Util; |
0356699b | 34 | with Lib; use Lib; |
13f34a3f | 35 | with Namet; use Namet; |
996ae0b0 RK |
36 | with Nmake; use Nmake; |
37 | with Nlists; use Nlists; | |
38 | with Opt; use Opt; | |
39 | with Sem; use Sem; | |
a4100e55 | 40 | with Sem_Aux; use Sem_Aux; |
996ae0b0 | 41 | with Sem_Cat; use Sem_Cat; |
b5bd964f | 42 | with Sem_Ch6; use Sem_Ch6; |
996ae0b0 RK |
43 | with Sem_Ch8; use Sem_Ch8; |
44 | with Sem_Res; use Sem_Res; | |
45 | with Sem_Util; use Sem_Util; | |
46 | with Sem_Type; use Sem_Type; | |
47 | with Sem_Warn; use Sem_Warn; | |
48 | with Sinfo; use Sinfo; | |
49 | with Snames; use Snames; | |
50 | with Stand; use Stand; | |
51 | with Stringt; use Stringt; | |
07fc65c4 | 52 | with Tbuild; use Tbuild; |
996ae0b0 RK |
53 | |
54 | package body Sem_Eval is | |
55 | ||
56 | ----------------------------------------- | |
57 | -- Handling of Compile Time Evaluation -- | |
58 | ----------------------------------------- | |
59 | ||
60 | -- The compile time evaluation of expressions is distributed over several | |
f3d57416 | 61 | -- Eval_xxx procedures. These procedures are called immediately after |
996ae0b0 RK |
62 | -- a subexpression is resolved and is therefore accomplished in a bottom |
63 | -- up fashion. The flags are synthesized using the following approach. | |
64 | ||
65 | -- Is_Static_Expression is determined by following the detailed rules | |
66 | -- in RM 4.9(4-14). This involves testing the Is_Static_Expression | |
67 | -- flag of the operands in many cases. | |
68 | ||
69 | -- Raises_Constraint_Error is set if any of the operands have the flag | |
70 | -- set or if an attempt to compute the value of the current expression | |
71 | -- results in detection of a runtime constraint error. | |
72 | ||
73 | -- As described in the spec, the requirement is that Is_Static_Expression | |
74 | -- be accurately set, and in addition for nodes for which this flag is set, | |
75 | -- Raises_Constraint_Error must also be set. Furthermore a node which has | |
76 | -- Is_Static_Expression set, and Raises_Constraint_Error clear, then the | |
77 | -- requirement is that the expression value must be precomputed, and the | |
78 | -- node is either a literal, or the name of a constant entity whose value | |
79 | -- is a static expression. | |
80 | ||
81 | -- The general approach is as follows. First compute Is_Static_Expression. | |
82 | -- If the node is not static, then the flag is left off in the node and | |
83 | -- we are all done. Otherwise for a static node, we test if any of the | |
84 | -- operands will raise constraint error, and if so, propagate the flag | |
85 | -- Raises_Constraint_Error to the result node and we are done (since the | |
86 | -- error was already posted at a lower level). | |
87 | ||
88 | -- For the case of a static node whose operands do not raise constraint | |
89 | -- error, we attempt to evaluate the node. If this evaluation succeeds, | |
90 | -- then the node is replaced by the result of this computation. If the | |
91 | -- evaluation raises constraint error, then we rewrite the node with | |
92 | -- Apply_Compile_Time_Constraint_Error to raise the exception and also | |
93 | -- to post appropriate error messages. | |
94 | ||
95 | ---------------- | |
96 | -- Local Data -- | |
97 | ---------------- | |
98 | ||
99 | type Bits is array (Nat range <>) of Boolean; | |
100 | -- Used to convert unsigned (modular) values for folding logical ops | |
101 | ||
07fc65c4 GB |
102 | -- The following definitions are used to maintain a cache of nodes that |
103 | -- have compile time known values. The cache is maintained only for | |
104 | -- discrete types (the most common case), and is populated by calls to | |
105 | -- Compile_Time_Known_Value and Expr_Value, but only used by Expr_Value | |
106 | -- since it is possible for the status to change (in particular it is | |
107 | -- possible for a node to get replaced by a constraint error node). | |
108 | ||
109 | CV_Bits : constant := 5; | |
110 | -- Number of low order bits of Node_Id value used to reference entries | |
111 | -- in the cache table. | |
112 | ||
113 | CV_Cache_Size : constant Nat := 2 ** CV_Bits; | |
114 | -- Size of cache for compile time values | |
115 | ||
116 | subtype CV_Range is Nat range 0 .. CV_Cache_Size; | |
117 | ||
118 | type CV_Entry is record | |
119 | N : Node_Id; | |
120 | V : Uint; | |
121 | end record; | |
122 | ||
123 | type CV_Cache_Array is array (CV_Range) of CV_Entry; | |
124 | ||
125 | CV_Cache : CV_Cache_Array := (others => (Node_High_Bound, Uint_0)); | |
126 | -- This is the actual cache, with entries consisting of node/value pairs, | |
127 | -- and the impossible value Node_High_Bound used for unset entries. | |
128 | ||
996ae0b0 RK |
129 | ----------------------- |
130 | -- Local Subprograms -- | |
131 | ----------------------- | |
132 | ||
996ae0b0 RK |
133 | function From_Bits (B : Bits; T : Entity_Id) return Uint; |
134 | -- Converts a bit string of length B'Length to a Uint value to be used | |
135 | -- for a target of type T, which is a modular type. This procedure | |
136 | -- includes the necessary reduction by the modulus in the case of a | |
137 | -- non-binary modulus (for a binary modulus, the bit string is the | |
138 | -- right length any way so all is well). | |
139 | ||
140 | function Get_String_Val (N : Node_Id) return Node_Id; | |
141 | -- Given a tree node for a folded string or character value, returns | |
142 | -- the corresponding string literal or character literal (one of the | |
143 | -- two must be available, or the operand would not have been marked | |
144 | -- as foldable in the earlier analysis of the operation). | |
145 | ||
07fc65c4 GB |
146 | function OK_Bits (N : Node_Id; Bits : Uint) return Boolean; |
147 | -- Bits represents the number of bits in an integer value to be computed | |
148 | -- (but the value has not been computed yet). If this value in Bits is | |
149 | -- reasonable, a result of True is returned, with the implication that | |
150 | -- the caller should go ahead and complete the calculation. If the value | |
151 | -- in Bits is unreasonably large, then an error is posted on node N, and | |
152 | -- False is returned (and the caller skips the proposed calculation). | |
153 | ||
996ae0b0 RK |
154 | procedure Out_Of_Range (N : Node_Id); |
155 | -- This procedure is called if it is determined that node N, which | |
156 | -- appears in a non-static context, is a compile time known value | |
157 | -- which is outside its range, i.e. the range of Etype. This is used | |
158 | -- in contexts where this is an illegality if N is static, and should | |
159 | -- generate a warning otherwise. | |
160 | ||
161 | procedure Rewrite_In_Raise_CE (N : Node_Id; Exp : Node_Id); | |
162 | -- N and Exp are nodes representing an expression, Exp is known | |
163 | -- to raise CE. N is rewritten in term of Exp in the optimal way. | |
164 | ||
165 | function String_Type_Len (Stype : Entity_Id) return Uint; | |
166 | -- Given a string type, determines the length of the index type, or, | |
167 | -- if this index type is non-static, the length of the base type of | |
168 | -- this index type. Note that if the string type is itself static, | |
169 | -- then the index type is static, so the second case applies only | |
170 | -- if the string type passed is non-static. | |
171 | ||
172 | function Test (Cond : Boolean) return Uint; | |
173 | pragma Inline (Test); | |
174 | -- This function simply returns the appropriate Boolean'Pos value | |
175 | -- corresponding to the value of Cond as a universal integer. It is | |
176 | -- used for producing the result of the static evaluation of the | |
177 | -- logical operators | |
178 | ||
179 | procedure Test_Expression_Is_Foldable | |
180 | (N : Node_Id; | |
181 | Op1 : Node_Id; | |
182 | Stat : out Boolean; | |
183 | Fold : out Boolean); | |
184 | -- Tests to see if expression N whose single operand is Op1 is foldable, | |
185 | -- i.e. the operand value is known at compile time. If the operation is | |
186 | -- foldable, then Fold is True on return, and Stat indicates whether | |
187 | -- the result is static (i.e. both operands were static). Note that it | |
188 | -- is quite possible for Fold to be True, and Stat to be False, since | |
189 | -- there are cases in which we know the value of an operand even though | |
190 | -- it is not technically static (e.g. the static lower bound of a range | |
191 | -- whose upper bound is non-static). | |
192 | -- | |
3d5952be | 193 | -- If Stat is set False on return, then Test_Expression_Is_Foldable makes a |
996ae0b0 RK |
194 | -- call to Check_Non_Static_Context on the operand. If Fold is False on |
195 | -- return, then all processing is complete, and the caller should | |
196 | -- return, since there is nothing else to do. | |
93c3fca7 AC |
197 | -- |
198 | -- If Stat is set True on return, then Is_Static_Expression is also set | |
199 | -- true in node N. There are some cases where this is over-enthusiastic, | |
200 | -- e.g. in the two operand case below, for string comaprison, the result | |
201 | -- is not static even though the two operands are static. In such cases, | |
202 | -- the caller must reset the Is_Static_Expression flag in N. | |
996ae0b0 RK |
203 | |
204 | procedure Test_Expression_Is_Foldable | |
205 | (N : Node_Id; | |
206 | Op1 : Node_Id; | |
207 | Op2 : Node_Id; | |
208 | Stat : out Boolean; | |
209 | Fold : out Boolean); | |
210 | -- Same processing, except applies to an expression N with two operands | |
211 | -- Op1 and Op2. | |
212 | ||
213 | procedure To_Bits (U : Uint; B : out Bits); | |
214 | -- Converts a Uint value to a bit string of length B'Length | |
215 | ||
216 | ------------------------------ | |
217 | -- Check_Non_Static_Context -- | |
218 | ------------------------------ | |
219 | ||
220 | procedure Check_Non_Static_Context (N : Node_Id) is | |
fbf5a39b AC |
221 | T : constant Entity_Id := Etype (N); |
222 | Checks_On : constant Boolean := | |
996ae0b0 RK |
223 | not Index_Checks_Suppressed (T) |
224 | and not Range_Checks_Suppressed (T); | |
225 | ||
226 | begin | |
fbf5a39b | 227 | -- Ignore cases of non-scalar types or error types |
996ae0b0 | 228 | |
fbf5a39b | 229 | if T = Any_Type or else not Is_Scalar_Type (T) then |
996ae0b0 | 230 | return; |
fbf5a39b | 231 | end if; |
996ae0b0 | 232 | |
fbf5a39b AC |
233 | -- At this stage we have a scalar type. If we have an expression |
234 | -- that raises CE, then we already issued a warning or error msg | |
235 | -- so there is nothing more to be done in this routine. | |
236 | ||
237 | if Raises_Constraint_Error (N) then | |
238 | return; | |
239 | end if; | |
240 | ||
241 | -- Now we have a scalar type which is not marked as raising a | |
242 | -- constraint error exception. The main purpose of this routine | |
243 | -- is to deal with static expressions appearing in a non-static | |
244 | -- context. That means that if we do not have a static expression | |
245 | -- then there is not much to do. The one case that we deal with | |
246 | -- here is that if we have a floating-point value that is out of | |
247 | -- range, then we post a warning that an infinity will result. | |
248 | ||
249 | if not Is_Static_Expression (N) then | |
250 | if Is_Floating_Point_Type (T) | |
c800f862 | 251 | and then Is_Out_Of_Range (N, Base_Type (T), Assume_Valid => True) |
fbf5a39b AC |
252 | then |
253 | Error_Msg_N | |
254 | ("?float value out of range, infinity will be generated", N); | |
255 | end if; | |
996ae0b0 | 256 | |
996ae0b0 RK |
257 | return; |
258 | end if; | |
259 | ||
260 | -- Here we have the case of outer level static expression of | |
261 | -- scalar type, where the processing of this procedure is needed. | |
262 | ||
263 | -- For real types, this is where we convert the value to a machine | |
264 | -- number (see RM 4.9(38)). Also see ACVC test C490001. We should | |
265 | -- only need to do this if the parent is a constant declaration, | |
266 | -- since in other cases, gigi should do the necessary conversion | |
267 | -- correctly, but experimentation shows that this is not the case | |
268 | -- on all machines, in particular if we do not convert all literals | |
269 | -- to machine values in non-static contexts, then ACVC test C490001 | |
270 | -- fails on Sparc/Solaris and SGI/Irix. | |
271 | ||
272 | if Nkind (N) = N_Real_Literal | |
273 | and then not Is_Machine_Number (N) | |
274 | and then not Is_Generic_Type (Etype (N)) | |
275 | and then Etype (N) /= Universal_Real | |
996ae0b0 RK |
276 | then |
277 | -- Check that value is in bounds before converting to machine | |
278 | -- number, so as not to lose case where value overflows in the | |
279 | -- least significant bit or less. See B490001. | |
280 | ||
c800f862 | 281 | if Is_Out_Of_Range (N, Base_Type (T), Assume_Valid => True) then |
996ae0b0 RK |
282 | Out_Of_Range (N); |
283 | return; | |
284 | end if; | |
285 | ||
286 | -- Note: we have to copy the node, to avoid problems with conformance | |
287 | -- of very similar numbers (see ACVC tests B4A010C and B63103A). | |
288 | ||
289 | Rewrite (N, New_Copy (N)); | |
290 | ||
291 | if not Is_Floating_Point_Type (T) then | |
292 | Set_Realval | |
293 | (N, Corresponding_Integer_Value (N) * Small_Value (T)); | |
294 | ||
295 | elsif not UR_Is_Zero (Realval (N)) then | |
996ae0b0 | 296 | |
fbf5a39b AC |
297 | -- Note: even though RM 4.9(38) specifies biased rounding, |
298 | -- this has been modified by AI-100 in order to prevent | |
299 | -- confusing differences in rounding between static and | |
300 | -- non-static expressions. AI-100 specifies that the effect | |
301 | -- of such rounding is implementation dependent, and in GNAT | |
302 | -- we round to nearest even to match the run-time behavior. | |
996ae0b0 | 303 | |
fbf5a39b AC |
304 | Set_Realval |
305 | (N, Machine (Base_Type (T), Realval (N), Round_Even, N)); | |
996ae0b0 RK |
306 | end if; |
307 | ||
308 | Set_Is_Machine_Number (N); | |
309 | end if; | |
310 | ||
311 | -- Check for out of range universal integer. This is a non-static | |
312 | -- context, so the integer value must be in range of the runtime | |
313 | -- representation of universal integers. | |
314 | ||
315 | -- We do this only within an expression, because that is the only | |
316 | -- case in which non-static universal integer values can occur, and | |
317 | -- furthermore, Check_Non_Static_Context is currently (incorrectly???) | |
318 | -- called in contexts like the expression of a number declaration where | |
319 | -- we certainly want to allow out of range values. | |
320 | ||
321 | if Etype (N) = Universal_Integer | |
322 | and then Nkind (N) = N_Integer_Literal | |
323 | and then Nkind (Parent (N)) in N_Subexpr | |
324 | and then | |
325 | (Intval (N) < Expr_Value (Type_Low_Bound (Universal_Integer)) | |
326 | or else | |
327 | Intval (N) > Expr_Value (Type_High_Bound (Universal_Integer))) | |
328 | then | |
329 | Apply_Compile_Time_Constraint_Error | |
07fc65c4 GB |
330 | (N, "non-static universal integer value out of range?", |
331 | CE_Range_Check_Failed); | |
996ae0b0 RK |
332 | |
333 | -- Check out of range of base type | |
334 | ||
c800f862 | 335 | elsif Is_Out_Of_Range (N, Base_Type (T), Assume_Valid => True) then |
996ae0b0 RK |
336 | Out_Of_Range (N); |
337 | ||
c800f862 RD |
338 | -- Give warning if outside subtype (where one or both of the bounds of |
339 | -- the subtype is static). This warning is omitted if the expression | |
340 | -- appears in a range that could be null (warnings are handled elsewhere | |
341 | -- for this case). | |
996ae0b0 RK |
342 | |
343 | elsif T /= Base_Type (T) | |
344 | and then Nkind (Parent (N)) /= N_Range | |
345 | then | |
c800f862 | 346 | if Is_In_Range (N, T, Assume_Valid => True) then |
996ae0b0 RK |
347 | null; |
348 | ||
c800f862 | 349 | elsif Is_Out_Of_Range (N, T, Assume_Valid => True) then |
996ae0b0 | 350 | Apply_Compile_Time_Constraint_Error |
07fc65c4 | 351 | (N, "value not in range of}?", CE_Range_Check_Failed); |
996ae0b0 RK |
352 | |
353 | elsif Checks_On then | |
354 | Enable_Range_Check (N); | |
355 | ||
356 | else | |
357 | Set_Do_Range_Check (N, False); | |
358 | end if; | |
359 | end if; | |
360 | end Check_Non_Static_Context; | |
361 | ||
362 | --------------------------------- | |
363 | -- Check_String_Literal_Length -- | |
364 | --------------------------------- | |
365 | ||
366 | procedure Check_String_Literal_Length (N : Node_Id; Ttype : Entity_Id) is | |
367 | begin | |
368 | if not Raises_Constraint_Error (N) | |
369 | and then Is_Constrained (Ttype) | |
370 | then | |
371 | if | |
372 | UI_From_Int (String_Length (Strval (N))) /= String_Type_Len (Ttype) | |
373 | then | |
374 | Apply_Compile_Time_Constraint_Error | |
375 | (N, "string length wrong for}?", | |
07fc65c4 | 376 | CE_Length_Check_Failed, |
996ae0b0 RK |
377 | Ent => Ttype, |
378 | Typ => Ttype); | |
379 | end if; | |
380 | end if; | |
381 | end Check_String_Literal_Length; | |
382 | ||
383 | -------------------------- | |
384 | -- Compile_Time_Compare -- | |
385 | -------------------------- | |
386 | ||
fbf5a39b | 387 | function Compile_Time_Compare |
1c7717c3 | 388 | (L, R : Node_Id; |
af02a866 RD |
389 | Assume_Valid : Boolean) return Compare_Result |
390 | is | |
391 | Discard : aliased Uint; | |
392 | begin | |
393 | return Compile_Time_Compare (L, R, Discard'Access, Assume_Valid); | |
394 | end Compile_Time_Compare; | |
395 | ||
396 | function Compile_Time_Compare | |
397 | (L, R : Node_Id; | |
398 | Diff : access Uint; | |
1c7717c3 AC |
399 | Assume_Valid : Boolean; |
400 | Rec : Boolean := False) return Compare_Result | |
fbf5a39b | 401 | is |
93c3fca7 AC |
402 | Ltyp : Entity_Id := Underlying_Type (Etype (L)); |
403 | Rtyp : Entity_Id := Underlying_Type (Etype (R)); | |
1c7717c3 AC |
404 | -- These get reset to the base type for the case of entities where |
405 | -- Is_Known_Valid is not set. This takes care of handling possible | |
406 | -- invalid representations using the value of the base type, in | |
407 | -- accordance with RM 13.9.1(10). | |
996ae0b0 | 408 | |
af02a866 RD |
409 | Discard : aliased Uint; |
410 | ||
996ae0b0 RK |
411 | procedure Compare_Decompose |
412 | (N : Node_Id; | |
413 | R : out Node_Id; | |
414 | V : out Uint); | |
b49365b2 RD |
415 | -- This procedure decomposes the node N into an expression node and a |
416 | -- signed offset, so that the value of N is equal to the value of R plus | |
417 | -- the value V (which may be negative). If no such decomposition is | |
418 | -- possible, then on return R is a copy of N, and V is set to zero. | |
996ae0b0 RK |
419 | |
420 | function Compare_Fixup (N : Node_Id) return Node_Id; | |
b49365b2 RD |
421 | -- This function deals with replacing 'Last and 'First references with |
422 | -- their corresponding type bounds, which we then can compare. The | |
423 | -- argument is the original node, the result is the identity, unless we | |
424 | -- have a 'Last/'First reference in which case the value returned is the | |
425 | -- appropriate type bound. | |
996ae0b0 RK |
426 | |
427 | function Is_Same_Value (L, R : Node_Id) return Boolean; | |
428 | -- Returns True iff L and R represent expressions that definitely | |
429 | -- have identical (but not necessarily compile time known) values | |
430 | -- Indeed the caller is expected to have already dealt with the | |
431 | -- cases of compile time known values, so these are not tested here. | |
432 | ||
433 | ----------------------- | |
434 | -- Compare_Decompose -- | |
435 | ----------------------- | |
436 | ||
437 | procedure Compare_Decompose | |
438 | (N : Node_Id; | |
439 | R : out Node_Id; | |
440 | V : out Uint) | |
441 | is | |
442 | begin | |
443 | if Nkind (N) = N_Op_Add | |
444 | and then Nkind (Right_Opnd (N)) = N_Integer_Literal | |
445 | then | |
446 | R := Left_Opnd (N); | |
447 | V := Intval (Right_Opnd (N)); | |
448 | return; | |
449 | ||
450 | elsif Nkind (N) = N_Op_Subtract | |
451 | and then Nkind (Right_Opnd (N)) = N_Integer_Literal | |
452 | then | |
453 | R := Left_Opnd (N); | |
454 | V := UI_Negate (Intval (Right_Opnd (N))); | |
455 | return; | |
456 | ||
457 | elsif Nkind (N) = N_Attribute_Reference then | |
996ae0b0 RK |
458 | if Attribute_Name (N) = Name_Succ then |
459 | R := First (Expressions (N)); | |
460 | V := Uint_1; | |
461 | return; | |
462 | ||
463 | elsif Attribute_Name (N) = Name_Pred then | |
464 | R := First (Expressions (N)); | |
465 | V := Uint_Minus_1; | |
466 | return; | |
467 | end if; | |
468 | end if; | |
469 | ||
470 | R := N; | |
471 | V := Uint_0; | |
472 | end Compare_Decompose; | |
473 | ||
474 | ------------------- | |
475 | -- Compare_Fixup -- | |
476 | ------------------- | |
477 | ||
478 | function Compare_Fixup (N : Node_Id) return Node_Id is | |
479 | Indx : Node_Id; | |
480 | Xtyp : Entity_Id; | |
481 | Subs : Nat; | |
482 | ||
483 | begin | |
484 | if Nkind (N) = N_Attribute_Reference | |
485 | and then (Attribute_Name (N) = Name_First | |
486 | or else | |
487 | Attribute_Name (N) = Name_Last) | |
488 | then | |
489 | Xtyp := Etype (Prefix (N)); | |
490 | ||
491 | -- If we have no type, then just abandon the attempt to do | |
492 | -- a fixup, this is probably the result of some other error. | |
493 | ||
494 | if No (Xtyp) then | |
495 | return N; | |
496 | end if; | |
497 | ||
498 | -- Dereference an access type | |
499 | ||
500 | if Is_Access_Type (Xtyp) then | |
501 | Xtyp := Designated_Type (Xtyp); | |
502 | end if; | |
503 | ||
504 | -- If we don't have an array type at this stage, something | |
505 | -- is peculiar, e.g. another error, and we abandon the attempt | |
506 | -- at a fixup. | |
507 | ||
508 | if not Is_Array_Type (Xtyp) then | |
509 | return N; | |
510 | end if; | |
511 | ||
512 | -- Ignore unconstrained array, since bounds are not meaningful | |
513 | ||
514 | if not Is_Constrained (Xtyp) then | |
515 | return N; | |
516 | end if; | |
517 | ||
c3de5c4c ES |
518 | if Ekind (Xtyp) = E_String_Literal_Subtype then |
519 | if Attribute_Name (N) = Name_First then | |
520 | return String_Literal_Low_Bound (Xtyp); | |
521 | ||
522 | else -- Attribute_Name (N) = Name_Last | |
523 | return Make_Integer_Literal (Sloc (N), | |
524 | Intval => Intval (String_Literal_Low_Bound (Xtyp)) | |
525 | + String_Literal_Length (Xtyp)); | |
526 | end if; | |
527 | end if; | |
528 | ||
996ae0b0 RK |
529 | -- Find correct index type |
530 | ||
531 | Indx := First_Index (Xtyp); | |
532 | ||
533 | if Present (Expressions (N)) then | |
534 | Subs := UI_To_Int (Expr_Value (First (Expressions (N)))); | |
535 | ||
536 | for J in 2 .. Subs loop | |
537 | Indx := Next_Index (Indx); | |
538 | end loop; | |
539 | end if; | |
540 | ||
541 | Xtyp := Etype (Indx); | |
542 | ||
543 | if Attribute_Name (N) = Name_First then | |
544 | return Type_Low_Bound (Xtyp); | |
545 | ||
546 | else -- Attribute_Name (N) = Name_Last | |
547 | return Type_High_Bound (Xtyp); | |
548 | end if; | |
549 | end if; | |
550 | ||
551 | return N; | |
552 | end Compare_Fixup; | |
553 | ||
554 | ------------------- | |
555 | -- Is_Same_Value -- | |
556 | ------------------- | |
557 | ||
558 | function Is_Same_Value (L, R : Node_Id) return Boolean is | |
559 | Lf : constant Node_Id := Compare_Fixup (L); | |
560 | Rf : constant Node_Id := Compare_Fixup (R); | |
561 | ||
fbf5a39b AC |
562 | function Is_Same_Subscript (L, R : List_Id) return Boolean; |
563 | -- L, R are the Expressions values from two attribute nodes | |
564 | -- for First or Last attributes. Either may be set to No_List | |
565 | -- if no expressions are present (indicating subscript 1). | |
566 | -- The result is True if both expressions represent the same | |
567 | -- subscript (note that one case is where one subscript is | |
568 | -- missing and the other is explicitly set to 1). | |
569 | ||
570 | ----------------------- | |
571 | -- Is_Same_Subscript -- | |
572 | ----------------------- | |
573 | ||
574 | function Is_Same_Subscript (L, R : List_Id) return Boolean is | |
575 | begin | |
576 | if L = No_List then | |
577 | if R = No_List then | |
578 | return True; | |
579 | else | |
580 | return Expr_Value (First (R)) = Uint_1; | |
581 | end if; | |
582 | ||
583 | else | |
584 | if R = No_List then | |
585 | return Expr_Value (First (L)) = Uint_1; | |
586 | else | |
587 | return Expr_Value (First (L)) = Expr_Value (First (R)); | |
588 | end if; | |
589 | end if; | |
590 | end Is_Same_Subscript; | |
591 | ||
592 | -- Start of processing for Is_Same_Value | |
593 | ||
996ae0b0 | 594 | begin |
b49365b2 | 595 | -- Values are the same if they refer to the same entity and the |
c800f862 RD |
596 | -- entity is non-volatile. This does not however apply to Float |
597 | -- types, since we may have two NaN values and they should never | |
598 | -- compare equal. | |
996ae0b0 | 599 | |
b49365b2 RD |
600 | if Nkind_In (Lf, N_Identifier, N_Expanded_Name) |
601 | and then Nkind_In (Rf, N_Identifier, N_Expanded_Name) | |
996ae0b0 | 602 | and then Entity (Lf) = Entity (Rf) |
b49365b2 | 603 | and then Present (Entity (Lf)) |
fbf5a39b | 604 | and then not Is_Floating_Point_Type (Etype (L)) |
c800f862 RD |
605 | and then not Is_Volatile_Reference (L) |
606 | and then not Is_Volatile_Reference (R) | |
996ae0b0 RK |
607 | then |
608 | return True; | |
609 | ||
610 | -- Or if they are compile time known and identical | |
611 | ||
612 | elsif Compile_Time_Known_Value (Lf) | |
613 | and then | |
614 | Compile_Time_Known_Value (Rf) | |
615 | and then Expr_Value (Lf) = Expr_Value (Rf) | |
616 | then | |
617 | return True; | |
618 | ||
b49365b2 RD |
619 | -- False if Nkind of the two nodes is different for remaining cases |
620 | ||
621 | elsif Nkind (Lf) /= Nkind (Rf) then | |
622 | return False; | |
623 | ||
624 | -- True if both 'First or 'Last values applying to the same entity | |
625 | -- (first and last don't change even if value does). Note that we | |
626 | -- need this even with the calls to Compare_Fixup, to handle the | |
627 | -- case of unconstrained array attributes where Compare_Fixup | |
628 | -- cannot find useful bounds. | |
996ae0b0 RK |
629 | |
630 | elsif Nkind (Lf) = N_Attribute_Reference | |
996ae0b0 RK |
631 | and then Attribute_Name (Lf) = Attribute_Name (Rf) |
632 | and then (Attribute_Name (Lf) = Name_First | |
633 | or else | |
634 | Attribute_Name (Lf) = Name_Last) | |
b49365b2 RD |
635 | and then Nkind_In (Prefix (Lf), N_Identifier, N_Expanded_Name) |
636 | and then Nkind_In (Prefix (Rf), N_Identifier, N_Expanded_Name) | |
996ae0b0 | 637 | and then Entity (Prefix (Lf)) = Entity (Prefix (Rf)) |
fbf5a39b | 638 | and then Is_Same_Subscript (Expressions (Lf), Expressions (Rf)) |
996ae0b0 RK |
639 | then |
640 | return True; | |
641 | ||
b49365b2 RD |
642 | -- True if the same selected component from the same record |
643 | ||
644 | elsif Nkind (Lf) = N_Selected_Component | |
645 | and then Selector_Name (Lf) = Selector_Name (Rf) | |
646 | and then Is_Same_Value (Prefix (Lf), Prefix (Rf)) | |
647 | then | |
648 | return True; | |
649 | ||
650 | -- True if the same unary operator applied to the same operand | |
651 | ||
652 | elsif Nkind (Lf) in N_Unary_Op | |
653 | and then Is_Same_Value (Right_Opnd (Lf), Right_Opnd (Rf)) | |
654 | then | |
655 | return True; | |
656 | ||
8682d22c | 657 | -- True if the same binary operator applied to the same operands |
b49365b2 RD |
658 | |
659 | elsif Nkind (Lf) in N_Binary_Op | |
660 | and then Is_Same_Value (Left_Opnd (Lf), Left_Opnd (Rf)) | |
661 | and then Is_Same_Value (Right_Opnd (Lf), Right_Opnd (Rf)) | |
662 | then | |
663 | return True; | |
664 | ||
8682d22c | 665 | -- All other cases, we can't tell, so return False |
996ae0b0 RK |
666 | |
667 | else | |
668 | return False; | |
669 | end if; | |
670 | end Is_Same_Value; | |
671 | ||
672 | -- Start of processing for Compile_Time_Compare | |
673 | ||
674 | begin | |
af02a866 RD |
675 | Diff.all := No_Uint; |
676 | ||
07fc65c4 GB |
677 | -- If either operand could raise constraint error, then we cannot |
678 | -- know the result at compile time (since CE may be raised!) | |
679 | ||
680 | if not (Cannot_Raise_Constraint_Error (L) | |
681 | and then | |
682 | Cannot_Raise_Constraint_Error (R)) | |
683 | then | |
684 | return Unknown; | |
685 | end if; | |
686 | ||
687 | -- Identical operands are most certainly equal | |
688 | ||
996ae0b0 RK |
689 | if L = R then |
690 | return EQ; | |
691 | ||
93c3fca7 AC |
692 | -- If expressions have no types, then do not attempt to determine if |
693 | -- they are the same, since something funny is going on. One case in | |
694 | -- which this happens is during generic template analysis, when bounds | |
695 | -- are not fully analyzed. | |
996ae0b0 RK |
696 | |
697 | elsif No (Ltyp) or else No (Rtyp) then | |
698 | return Unknown; | |
699 | ||
93c3fca7 AC |
700 | -- We do not attempt comparisons for packed arrays arrays represented as |
701 | -- modular types, where the semantics of comparison is quite different. | |
996ae0b0 | 702 | |
93c3fca7 AC |
703 | elsif Is_Packed_Array_Type (Ltyp) |
704 | and then Is_Modular_Integer_Type (Ltyp) | |
996ae0b0 RK |
705 | then |
706 | return Unknown; | |
707 | ||
93c3fca7 | 708 | -- For access types, the only time we know the result at compile time |
f61580d4 | 709 | -- (apart from identical operands, which we handled already) is if we |
93c3fca7 AC |
710 | -- know one operand is null and the other is not, or both operands are |
711 | -- known null. | |
712 | ||
713 | elsif Is_Access_Type (Ltyp) then | |
714 | if Known_Null (L) then | |
715 | if Known_Null (R) then | |
716 | return EQ; | |
717 | elsif Known_Non_Null (R) then | |
718 | return NE; | |
719 | else | |
720 | return Unknown; | |
721 | end if; | |
722 | ||
f61580d4 | 723 | elsif Known_Non_Null (L) and then Known_Null (R) then |
93c3fca7 AC |
724 | return NE; |
725 | ||
726 | else | |
727 | return Unknown; | |
728 | end if; | |
729 | ||
996ae0b0 RK |
730 | -- Case where comparison involves two compile time known values |
731 | ||
732 | elsif Compile_Time_Known_Value (L) | |
733 | and then Compile_Time_Known_Value (R) | |
734 | then | |
735 | -- For the floating-point case, we have to be a little careful, since | |
736 | -- at compile time we are dealing with universal exact values, but at | |
737 | -- runtime, these will be in non-exact target form. That's why the | |
738 | -- returned results are LE and GE below instead of LT and GT. | |
739 | ||
740 | if Is_Floating_Point_Type (Ltyp) | |
741 | or else | |
742 | Is_Floating_Point_Type (Rtyp) | |
743 | then | |
744 | declare | |
745 | Lo : constant Ureal := Expr_Value_R (L); | |
746 | Hi : constant Ureal := Expr_Value_R (R); | |
747 | ||
748 | begin | |
749 | if Lo < Hi then | |
750 | return LE; | |
751 | elsif Lo = Hi then | |
752 | return EQ; | |
753 | else | |
754 | return GE; | |
755 | end if; | |
756 | end; | |
757 | ||
93c3fca7 AC |
758 | -- For string types, we have two string literals and we proceed to |
759 | -- compare them using the Ada style dictionary string comparison. | |
760 | ||
761 | elsif not Is_Scalar_Type (Ltyp) then | |
762 | declare | |
763 | Lstring : constant String_Id := Strval (Expr_Value_S (L)); | |
764 | Rstring : constant String_Id := Strval (Expr_Value_S (R)); | |
765 | Llen : constant Nat := String_Length (Lstring); | |
766 | Rlen : constant Nat := String_Length (Rstring); | |
767 | ||
768 | begin | |
769 | for J in 1 .. Nat'Min (Llen, Rlen) loop | |
770 | declare | |
771 | LC : constant Char_Code := Get_String_Char (Lstring, J); | |
772 | RC : constant Char_Code := Get_String_Char (Rstring, J); | |
773 | begin | |
774 | if LC < RC then | |
775 | return LT; | |
776 | elsif LC > RC then | |
777 | return GT; | |
778 | end if; | |
779 | end; | |
780 | end loop; | |
781 | ||
782 | if Llen < Rlen then | |
783 | return LT; | |
784 | elsif Llen > Rlen then | |
785 | return GT; | |
786 | else | |
787 | return EQ; | |
788 | end if; | |
789 | end; | |
790 | ||
791 | -- For remaining scalar cases we know exactly (note that this does | |
792 | -- include the fixed-point case, where we know the run time integer | |
f61580d4 | 793 | -- values now). |
996ae0b0 RK |
794 | |
795 | else | |
796 | declare | |
797 | Lo : constant Uint := Expr_Value (L); | |
798 | Hi : constant Uint := Expr_Value (R); | |
799 | ||
800 | begin | |
801 | if Lo < Hi then | |
af02a866 | 802 | Diff.all := Hi - Lo; |
996ae0b0 | 803 | return LT; |
af02a866 | 804 | |
996ae0b0 RK |
805 | elsif Lo = Hi then |
806 | return EQ; | |
af02a866 | 807 | |
996ae0b0 | 808 | else |
af02a866 | 809 | Diff.all := Lo - Hi; |
996ae0b0 RK |
810 | return GT; |
811 | end if; | |
812 | end; | |
813 | end if; | |
814 | ||
815 | -- Cases where at least one operand is not known at compile time | |
816 | ||
817 | else | |
93c3fca7 | 818 | -- Remaining checks apply only for discrete types |
29797f34 RD |
819 | |
820 | if not Is_Discrete_Type (Ltyp) | |
821 | or else not Is_Discrete_Type (Rtyp) | |
93c3fca7 AC |
822 | then |
823 | return Unknown; | |
824 | end if; | |
825 | ||
826 | -- Defend against generic types, or actually any expressions that | |
827 | -- contain a reference to a generic type from within a generic | |
828 | -- template. We don't want to do any range analysis of such | |
829 | -- expressions for two reasons. First, the bounds of a generic type | |
830 | -- itself are junk and cannot be used for any kind of analysis. | |
831 | -- Second, we may have a case where the range at run time is indeed | |
832 | -- known, but we don't want to do compile time analysis in the | |
833 | -- template based on that range since in an instance the value may be | |
834 | -- static, and able to be elaborated without reference to the bounds | |
835 | -- of types involved. As an example, consider: | |
836 | ||
837 | -- (F'Pos (F'Last) + 1) > Integer'Last | |
838 | ||
839 | -- The expression on the left side of > is Universal_Integer and thus | |
840 | -- acquires the type Integer for evaluation at run time, and at run | |
841 | -- time it is true that this condition is always False, but within | |
842 | -- an instance F may be a type with a static range greater than the | |
843 | -- range of Integer, and the expression statically evaluates to True. | |
844 | ||
845 | if References_Generic_Formal_Type (L) | |
846 | or else | |
847 | References_Generic_Formal_Type (R) | |
29797f34 RD |
848 | then |
849 | return Unknown; | |
850 | end if; | |
851 | ||
1c7717c3 AC |
852 | -- Replace types by base types for the case of entities which are |
853 | -- not known to have valid representations. This takes care of | |
854 | -- properly dealing with invalid representations. | |
855 | ||
c800f862 | 856 | if not Assume_Valid and then not Assume_No_Invalid_Values then |
1c7717c3 | 857 | if Is_Entity_Name (L) and then not Is_Known_Valid (Entity (L)) then |
93c3fca7 | 858 | Ltyp := Underlying_Type (Base_Type (Ltyp)); |
1c7717c3 AC |
859 | end if; |
860 | ||
861 | if Is_Entity_Name (R) and then not Is_Known_Valid (Entity (R)) then | |
93c3fca7 | 862 | Rtyp := Underlying_Type (Base_Type (Rtyp)); |
1c7717c3 AC |
863 | end if; |
864 | end if; | |
865 | ||
c800f862 RD |
866 | -- Try range analysis on variables and see if ranges are disjoint |
867 | ||
868 | declare | |
869 | LOK, ROK : Boolean; | |
870 | LLo, LHi : Uint; | |
871 | RLo, RHi : Uint; | |
872 | ||
873 | begin | |
874 | Determine_Range (L, LOK, LLo, LHi, Assume_Valid); | |
875 | Determine_Range (R, ROK, RLo, RHi, Assume_Valid); | |
876 | ||
877 | if LOK and ROK then | |
878 | if LHi < RLo then | |
879 | return LT; | |
880 | ||
881 | elsif RHi < LLo then | |
882 | return GT; | |
883 | ||
884 | elsif LLo = LHi | |
885 | and then RLo = RHi | |
886 | and then LLo = RLo | |
887 | then | |
888 | return EQ; | |
889 | ||
890 | elsif LHi = RLo then | |
891 | return LE; | |
892 | ||
893 | elsif RHi = LLo then | |
894 | return GE; | |
895 | end if; | |
896 | end if; | |
897 | end; | |
898 | ||
996ae0b0 RK |
899 | -- Here is where we check for comparisons against maximum bounds of |
900 | -- types, where we know that no value can be outside the bounds of | |
901 | -- the subtype. Note that this routine is allowed to assume that all | |
902 | -- expressions are within their subtype bounds. Callers wishing to | |
903 | -- deal with possibly invalid values must in any case take special | |
904 | -- steps (e.g. conversions to larger types) to avoid this kind of | |
905 | -- optimization, which is always considered to be valid. We do not | |
906 | -- attempt this optimization with generic types, since the type | |
907 | -- bounds may not be meaningful in this case. | |
908 | ||
93c3fca7 | 909 | -- We are in danger of an infinite recursion here. It does not seem |
fbf5a39b AC |
910 | -- useful to go more than one level deep, so the parameter Rec is |
911 | -- used to protect ourselves against this infinite recursion. | |
912 | ||
29797f34 RD |
913 | if not Rec then |
914 | ||
fbf5a39b AC |
915 | -- See if we can get a decisive check against one operand and |
916 | -- a bound of the other operand (four possible tests here). | |
93c3fca7 AC |
917 | -- Note that we avoid testing junk bounds of a generic type. |
918 | ||
919 | if not Is_Generic_Type (Rtyp) then | |
920 | case Compile_Time_Compare (L, Type_Low_Bound (Rtyp), | |
921 | Discard'Access, | |
922 | Assume_Valid, Rec => True) | |
923 | is | |
924 | when LT => return LT; | |
925 | when LE => return LE; | |
926 | when EQ => return LE; | |
927 | when others => null; | |
928 | end case; | |
fbf5a39b | 929 | |
93c3fca7 AC |
930 | case Compile_Time_Compare (L, Type_High_Bound (Rtyp), |
931 | Discard'Access, | |
932 | Assume_Valid, Rec => True) | |
933 | is | |
934 | when GT => return GT; | |
935 | when GE => return GE; | |
936 | when EQ => return GE; | |
937 | when others => null; | |
938 | end case; | |
939 | end if; | |
996ae0b0 | 940 | |
93c3fca7 AC |
941 | if not Is_Generic_Type (Ltyp) then |
942 | case Compile_Time_Compare (Type_Low_Bound (Ltyp), R, | |
943 | Discard'Access, | |
944 | Assume_Valid, Rec => True) | |
945 | is | |
946 | when GT => return GT; | |
947 | when GE => return GE; | |
948 | when EQ => return GE; | |
949 | when others => null; | |
950 | end case; | |
996ae0b0 | 951 | |
93c3fca7 AC |
952 | case Compile_Time_Compare (Type_High_Bound (Ltyp), R, |
953 | Discard'Access, | |
954 | Assume_Valid, Rec => True) | |
955 | is | |
956 | when LT => return LT; | |
957 | when LE => return LE; | |
958 | when EQ => return LE; | |
959 | when others => null; | |
960 | end case; | |
961 | end if; | |
996ae0b0 RK |
962 | end if; |
963 | ||
964 | -- Next attempt is to decompose the expressions to extract | |
965 | -- a constant offset resulting from the use of any of the forms: | |
966 | ||
967 | -- expr + literal | |
968 | -- expr - literal | |
969 | -- typ'Succ (expr) | |
970 | -- typ'Pred (expr) | |
971 | ||
972 | -- Then we see if the two expressions are the same value, and if so | |
973 | -- the result is obtained by comparing the offsets. | |
974 | ||
975 | declare | |
976 | Lnode : Node_Id; | |
977 | Loffs : Uint; | |
978 | Rnode : Node_Id; | |
979 | Roffs : Uint; | |
980 | ||
981 | begin | |
982 | Compare_Decompose (L, Lnode, Loffs); | |
983 | Compare_Decompose (R, Rnode, Roffs); | |
984 | ||
985 | if Is_Same_Value (Lnode, Rnode) then | |
986 | if Loffs = Roffs then | |
987 | return EQ; | |
988 | ||
989 | elsif Loffs < Roffs then | |
af02a866 | 990 | Diff.all := Roffs - Loffs; |
996ae0b0 RK |
991 | return LT; |
992 | ||
993 | else | |
af02a866 | 994 | Diff.all := Loffs - Roffs; |
996ae0b0 RK |
995 | return GT; |
996 | end if; | |
29797f34 RD |
997 | end if; |
998 | end; | |
999 | ||
1000 | -- Next attempt is to see if we have an entity compared with a | |
1001 | -- compile time known value, where there is a current value | |
1002 | -- conditional for the entity which can tell us the result. | |
1003 | ||
1004 | declare | |
1005 | Var : Node_Id; | |
1006 | -- Entity variable (left operand) | |
1007 | ||
1008 | Val : Uint; | |
1009 | -- Value (right operand) | |
1010 | ||
1011 | Inv : Boolean; | |
1012 | -- If False, we have reversed the operands | |
1013 | ||
1014 | Op : Node_Kind; | |
1015 | -- Comparison operator kind from Get_Current_Value_Condition call | |
996ae0b0 | 1016 | |
29797f34 RD |
1017 | Opn : Node_Id; |
1018 | -- Value from Get_Current_Value_Condition call | |
1019 | ||
1020 | Opv : Uint; | |
1021 | -- Value of Opn | |
1022 | ||
1023 | Result : Compare_Result; | |
1024 | -- Known result before inversion | |
1025 | ||
1026 | begin | |
1027 | if Is_Entity_Name (L) | |
1028 | and then Compile_Time_Known_Value (R) | |
1029 | then | |
1030 | Var := L; | |
1031 | Val := Expr_Value (R); | |
1032 | Inv := False; | |
1033 | ||
1034 | elsif Is_Entity_Name (R) | |
1035 | and then Compile_Time_Known_Value (L) | |
1036 | then | |
1037 | Var := R; | |
1038 | Val := Expr_Value (L); | |
1039 | Inv := True; | |
1040 | ||
1041 | -- That was the last chance at finding a compile time result | |
996ae0b0 RK |
1042 | |
1043 | else | |
1044 | return Unknown; | |
1045 | end if; | |
29797f34 RD |
1046 | |
1047 | Get_Current_Value_Condition (Var, Op, Opn); | |
1048 | ||
1049 | -- That was the last chance, so if we got nothing return | |
1050 | ||
1051 | if No (Opn) then | |
1052 | return Unknown; | |
1053 | end if; | |
1054 | ||
1055 | Opv := Expr_Value (Opn); | |
1056 | ||
1057 | -- We got a comparison, so we might have something interesting | |
1058 | ||
1059 | -- Convert LE to LT and GE to GT, just so we have fewer cases | |
1060 | ||
1061 | if Op = N_Op_Le then | |
1062 | Op := N_Op_Lt; | |
1063 | Opv := Opv + 1; | |
af02a866 | 1064 | |
29797f34 RD |
1065 | elsif Op = N_Op_Ge then |
1066 | Op := N_Op_Gt; | |
1067 | Opv := Opv - 1; | |
1068 | end if; | |
1069 | ||
1070 | -- Deal with equality case | |
1071 | ||
1072 | if Op = N_Op_Eq then | |
1073 | if Val = Opv then | |
1074 | Result := EQ; | |
1075 | elsif Opv < Val then | |
1076 | Result := LT; | |
1077 | else | |
1078 | Result := GT; | |
1079 | end if; | |
1080 | ||
1081 | -- Deal with inequality case | |
1082 | ||
1083 | elsif Op = N_Op_Ne then | |
1084 | if Val = Opv then | |
1085 | Result := NE; | |
1086 | else | |
1087 | return Unknown; | |
1088 | end if; | |
1089 | ||
1090 | -- Deal with greater than case | |
1091 | ||
1092 | elsif Op = N_Op_Gt then | |
1093 | if Opv >= Val then | |
1094 | Result := GT; | |
1095 | elsif Opv = Val - 1 then | |
1096 | Result := GE; | |
1097 | else | |
1098 | return Unknown; | |
1099 | end if; | |
1100 | ||
1101 | -- Deal with less than case | |
1102 | ||
1103 | else pragma Assert (Op = N_Op_Lt); | |
1104 | if Opv <= Val then | |
1105 | Result := LT; | |
1106 | elsif Opv = Val + 1 then | |
1107 | Result := LE; | |
1108 | else | |
1109 | return Unknown; | |
1110 | end if; | |
1111 | end if; | |
1112 | ||
1113 | -- Deal with inverting result | |
1114 | ||
1115 | if Inv then | |
1116 | case Result is | |
1117 | when GT => return LT; | |
1118 | when GE => return LE; | |
1119 | when LT => return GT; | |
1120 | when LE => return GE; | |
1121 | when others => return Result; | |
1122 | end case; | |
1123 | end if; | |
1124 | ||
1125 | return Result; | |
996ae0b0 RK |
1126 | end; |
1127 | end if; | |
1128 | end Compile_Time_Compare; | |
1129 | ||
f44fe430 RD |
1130 | ------------------------------- |
1131 | -- Compile_Time_Known_Bounds -- | |
1132 | ------------------------------- | |
1133 | ||
1134 | function Compile_Time_Known_Bounds (T : Entity_Id) return Boolean is | |
1135 | Indx : Node_Id; | |
1136 | Typ : Entity_Id; | |
1137 | ||
1138 | begin | |
1139 | if not Is_Array_Type (T) then | |
1140 | return False; | |
1141 | end if; | |
1142 | ||
1143 | Indx := First_Index (T); | |
1144 | while Present (Indx) loop | |
1145 | Typ := Underlying_Type (Etype (Indx)); | |
93c3fca7 AC |
1146 | |
1147 | -- Never look at junk bounds of a generic type | |
1148 | ||
1149 | if Is_Generic_Type (Typ) then | |
1150 | return False; | |
1151 | end if; | |
1152 | ||
1153 | -- Otherwise check bounds for compile time known | |
1154 | ||
f44fe430 RD |
1155 | if not Compile_Time_Known_Value (Type_Low_Bound (Typ)) then |
1156 | return False; | |
1157 | elsif not Compile_Time_Known_Value (Type_High_Bound (Typ)) then | |
1158 | return False; | |
1159 | else | |
1160 | Next_Index (Indx); | |
1161 | end if; | |
1162 | end loop; | |
1163 | ||
1164 | return True; | |
1165 | end Compile_Time_Known_Bounds; | |
1166 | ||
996ae0b0 RK |
1167 | ------------------------------ |
1168 | -- Compile_Time_Known_Value -- | |
1169 | ------------------------------ | |
1170 | ||
1171 | function Compile_Time_Known_Value (Op : Node_Id) return Boolean is | |
07fc65c4 GB |
1172 | K : constant Node_Kind := Nkind (Op); |
1173 | CV_Ent : CV_Entry renames CV_Cache (Nat (Op) mod CV_Cache_Size); | |
996ae0b0 RK |
1174 | |
1175 | begin | |
1176 | -- Never known at compile time if bad type or raises constraint error | |
1177 | -- or empty (latter case occurs only as a result of a previous error) | |
1178 | ||
1179 | if No (Op) | |
1180 | or else Op = Error | |
1181 | or else Etype (Op) = Any_Type | |
1182 | or else Raises_Constraint_Error (Op) | |
1183 | then | |
1184 | return False; | |
1185 | end if; | |
1186 | ||
597d7158 GD |
1187 | -- If this is not a static expression or a null literal, and we are in |
1188 | -- configurable run-time mode, then we consider it not known at compile | |
1189 | -- time. This avoids anomalies where whether something is allowed with a | |
1190 | -- given configurable run-time library depends on how good the compiler | |
1191 | -- is at optimizing and knowing that things are constant when they are | |
1192 | -- nonstatic. | |
1193 | ||
1194 | if Configurable_Run_Time_Mode | |
1195 | and then K /= N_Null | |
1196 | and then not Is_Static_Expression (Op) | |
1197 | then | |
fbf5a39b AC |
1198 | return False; |
1199 | end if; | |
1200 | ||
996ae0b0 RK |
1201 | -- If we have an entity name, then see if it is the name of a constant |
1202 | -- and if so, test the corresponding constant value, or the name of | |
1203 | -- an enumeration literal, which is always a constant. | |
1204 | ||
1205 | if Present (Etype (Op)) and then Is_Entity_Name (Op) then | |
1206 | declare | |
1207 | E : constant Entity_Id := Entity (Op); | |
1208 | V : Node_Id; | |
1209 | ||
1210 | begin | |
1211 | -- Never known at compile time if it is a packed array value. | |
1212 | -- We might want to try to evaluate these at compile time one | |
1213 | -- day, but we do not make that attempt now. | |
1214 | ||
1215 | if Is_Packed_Array_Type (Etype (Op)) then | |
1216 | return False; | |
1217 | end if; | |
1218 | ||
1219 | if Ekind (E) = E_Enumeration_Literal then | |
1220 | return True; | |
1221 | ||
07fc65c4 | 1222 | elsif Ekind (E) = E_Constant then |
996ae0b0 RK |
1223 | V := Constant_Value (E); |
1224 | return Present (V) and then Compile_Time_Known_Value (V); | |
1225 | end if; | |
1226 | end; | |
1227 | ||
1228 | -- We have a value, see if it is compile time known | |
1229 | ||
1230 | else | |
07fc65c4 | 1231 | -- Integer literals are worth storing in the cache |
996ae0b0 | 1232 | |
07fc65c4 GB |
1233 | if K = N_Integer_Literal then |
1234 | CV_Ent.N := Op; | |
1235 | CV_Ent.V := Intval (Op); | |
1236 | return True; | |
1237 | ||
1238 | -- Other literals and NULL are known at compile time | |
1239 | ||
1240 | elsif | |
996ae0b0 RK |
1241 | K = N_Character_Literal |
1242 | or else | |
1243 | K = N_Real_Literal | |
1244 | or else | |
1245 | K = N_String_Literal | |
1246 | or else | |
1247 | K = N_Null | |
1248 | then | |
1249 | return True; | |
1250 | ||
1251 | -- Any reference to Null_Parameter is known at compile time. No | |
1252 | -- other attribute references (that have not already been folded) | |
1253 | -- are known at compile time. | |
1254 | ||
1255 | elsif K = N_Attribute_Reference then | |
1256 | return Attribute_Name (Op) = Name_Null_Parameter; | |
07fc65c4 | 1257 | end if; |
996ae0b0 | 1258 | end if; |
07fc65c4 GB |
1259 | |
1260 | -- If we fall through, not known at compile time | |
1261 | ||
1262 | return False; | |
1263 | ||
1264 | -- If we get an exception while trying to do this test, then some error | |
1265 | -- has occurred, and we simply say that the value is not known after all | |
1266 | ||
1267 | exception | |
1268 | when others => | |
1269 | return False; | |
996ae0b0 RK |
1270 | end Compile_Time_Known_Value; |
1271 | ||
1272 | -------------------------------------- | |
1273 | -- Compile_Time_Known_Value_Or_Aggr -- | |
1274 | -------------------------------------- | |
1275 | ||
1276 | function Compile_Time_Known_Value_Or_Aggr (Op : Node_Id) return Boolean is | |
1277 | begin | |
1278 | -- If we have an entity name, then see if it is the name of a constant | |
1279 | -- and if so, test the corresponding constant value, or the name of | |
1280 | -- an enumeration literal, which is always a constant. | |
1281 | ||
1282 | if Is_Entity_Name (Op) then | |
1283 | declare | |
1284 | E : constant Entity_Id := Entity (Op); | |
1285 | V : Node_Id; | |
1286 | ||
1287 | begin | |
1288 | if Ekind (E) = E_Enumeration_Literal then | |
1289 | return True; | |
1290 | ||
1291 | elsif Ekind (E) /= E_Constant then | |
1292 | return False; | |
1293 | ||
1294 | else | |
1295 | V := Constant_Value (E); | |
1296 | return Present (V) | |
1297 | and then Compile_Time_Known_Value_Or_Aggr (V); | |
1298 | end if; | |
1299 | end; | |
1300 | ||
1301 | -- We have a value, see if it is compile time known | |
1302 | ||
1303 | else | |
1304 | if Compile_Time_Known_Value (Op) then | |
1305 | return True; | |
1306 | ||
1307 | elsif Nkind (Op) = N_Aggregate then | |
1308 | ||
1309 | if Present (Expressions (Op)) then | |
1310 | declare | |
1311 | Expr : Node_Id; | |
1312 | ||
1313 | begin | |
1314 | Expr := First (Expressions (Op)); | |
1315 | while Present (Expr) loop | |
1316 | if not Compile_Time_Known_Value_Or_Aggr (Expr) then | |
1317 | return False; | |
1318 | end if; | |
1319 | ||
1320 | Next (Expr); | |
1321 | end loop; | |
1322 | end; | |
1323 | end if; | |
1324 | ||
1325 | if Present (Component_Associations (Op)) then | |
1326 | declare | |
1327 | Cass : Node_Id; | |
1328 | ||
1329 | begin | |
1330 | Cass := First (Component_Associations (Op)); | |
1331 | while Present (Cass) loop | |
1332 | if not | |
1333 | Compile_Time_Known_Value_Or_Aggr (Expression (Cass)) | |
1334 | then | |
1335 | return False; | |
1336 | end if; | |
1337 | ||
1338 | Next (Cass); | |
1339 | end loop; | |
1340 | end; | |
1341 | end if; | |
1342 | ||
1343 | return True; | |
1344 | ||
1345 | -- All other types of values are not known at compile time | |
1346 | ||
1347 | else | |
1348 | return False; | |
1349 | end if; | |
1350 | ||
1351 | end if; | |
1352 | end Compile_Time_Known_Value_Or_Aggr; | |
1353 | ||
1354 | ----------------- | |
1355 | -- Eval_Actual -- | |
1356 | ----------------- | |
1357 | ||
1358 | -- This is only called for actuals of functions that are not predefined | |
1359 | -- operators (which have already been rewritten as operators at this | |
1360 | -- stage), so the call can never be folded, and all that needs doing for | |
1361 | -- the actual is to do the check for a non-static context. | |
1362 | ||
1363 | procedure Eval_Actual (N : Node_Id) is | |
1364 | begin | |
1365 | Check_Non_Static_Context (N); | |
1366 | end Eval_Actual; | |
1367 | ||
1368 | -------------------- | |
1369 | -- Eval_Allocator -- | |
1370 | -------------------- | |
1371 | ||
1372 | -- Allocators are never static, so all we have to do is to do the | |
1373 | -- check for a non-static context if an expression is present. | |
1374 | ||
1375 | procedure Eval_Allocator (N : Node_Id) is | |
1376 | Expr : constant Node_Id := Expression (N); | |
1377 | ||
1378 | begin | |
1379 | if Nkind (Expr) = N_Qualified_Expression then | |
1380 | Check_Non_Static_Context (Expression (Expr)); | |
1381 | end if; | |
1382 | end Eval_Allocator; | |
1383 | ||
1384 | ------------------------ | |
1385 | -- Eval_Arithmetic_Op -- | |
1386 | ------------------------ | |
1387 | ||
1388 | -- Arithmetic operations are static functions, so the result is static | |
1389 | -- if both operands are static (RM 4.9(7), 4.9(20)). | |
1390 | ||
1391 | procedure Eval_Arithmetic_Op (N : Node_Id) is | |
1392 | Left : constant Node_Id := Left_Opnd (N); | |
1393 | Right : constant Node_Id := Right_Opnd (N); | |
1394 | Ltype : constant Entity_Id := Etype (Left); | |
1395 | Rtype : constant Entity_Id := Etype (Right); | |
1396 | Stat : Boolean; | |
1397 | Fold : Boolean; | |
1398 | ||
1399 | begin | |
1400 | -- If not foldable we are done | |
1401 | ||
1402 | Test_Expression_Is_Foldable (N, Left, Right, Stat, Fold); | |
1403 | ||
1404 | if not Fold then | |
1405 | return; | |
1406 | end if; | |
1407 | ||
1408 | -- Fold for cases where both operands are of integer type | |
1409 | ||
1410 | if Is_Integer_Type (Ltype) and then Is_Integer_Type (Rtype) then | |
1411 | declare | |
1412 | Left_Int : constant Uint := Expr_Value (Left); | |
1413 | Right_Int : constant Uint := Expr_Value (Right); | |
1414 | Result : Uint; | |
1415 | ||
1416 | begin | |
1417 | case Nkind (N) is | |
1418 | ||
1419 | when N_Op_Add => | |
1420 | Result := Left_Int + Right_Int; | |
1421 | ||
1422 | when N_Op_Subtract => | |
1423 | Result := Left_Int - Right_Int; | |
1424 | ||
1425 | when N_Op_Multiply => | |
1426 | if OK_Bits | |
1427 | (N, UI_From_Int | |
1428 | (Num_Bits (Left_Int) + Num_Bits (Right_Int))) | |
1429 | then | |
1430 | Result := Left_Int * Right_Int; | |
1431 | else | |
1432 | Result := Left_Int; | |
1433 | end if; | |
1434 | ||
1435 | when N_Op_Divide => | |
1436 | ||
1437 | -- The exception Constraint_Error is raised by integer | |
1438 | -- division, rem and mod if the right operand is zero. | |
1439 | ||
1440 | if Right_Int = 0 then | |
1441 | Apply_Compile_Time_Constraint_Error | |
fbf5a39b AC |
1442 | (N, "division by zero", |
1443 | CE_Divide_By_Zero, | |
1444 | Warn => not Stat); | |
996ae0b0 | 1445 | return; |
fbf5a39b | 1446 | |
996ae0b0 RK |
1447 | else |
1448 | Result := Left_Int / Right_Int; | |
1449 | end if; | |
1450 | ||
1451 | when N_Op_Mod => | |
1452 | ||
1453 | -- The exception Constraint_Error is raised by integer | |
1454 | -- division, rem and mod if the right operand is zero. | |
1455 | ||
1456 | if Right_Int = 0 then | |
1457 | Apply_Compile_Time_Constraint_Error | |
fbf5a39b AC |
1458 | (N, "mod with zero divisor", |
1459 | CE_Divide_By_Zero, | |
1460 | Warn => not Stat); | |
996ae0b0 RK |
1461 | return; |
1462 | else | |
1463 | Result := Left_Int mod Right_Int; | |
1464 | end if; | |
1465 | ||
1466 | when N_Op_Rem => | |
1467 | ||
1468 | -- The exception Constraint_Error is raised by integer | |
1469 | -- division, rem and mod if the right operand is zero. | |
1470 | ||
1471 | if Right_Int = 0 then | |
1472 | Apply_Compile_Time_Constraint_Error | |
fbf5a39b AC |
1473 | (N, "rem with zero divisor", |
1474 | CE_Divide_By_Zero, | |
1475 | Warn => not Stat); | |
996ae0b0 | 1476 | return; |
fbf5a39b | 1477 | |
996ae0b0 RK |
1478 | else |
1479 | Result := Left_Int rem Right_Int; | |
1480 | end if; | |
1481 | ||
1482 | when others => | |
1483 | raise Program_Error; | |
1484 | end case; | |
1485 | ||
1486 | -- Adjust the result by the modulus if the type is a modular type | |
1487 | ||
1488 | if Is_Modular_Integer_Type (Ltype) then | |
1489 | Result := Result mod Modulus (Ltype); | |
82c80734 RD |
1490 | |
1491 | -- For a signed integer type, check non-static overflow | |
1492 | ||
1493 | elsif (not Stat) and then Is_Signed_Integer_Type (Ltype) then | |
1494 | declare | |
1495 | BT : constant Entity_Id := Base_Type (Ltype); | |
1496 | Lo : constant Uint := Expr_Value (Type_Low_Bound (BT)); | |
1497 | Hi : constant Uint := Expr_Value (Type_High_Bound (BT)); | |
1498 | begin | |
1499 | if Result < Lo or else Result > Hi then | |
1500 | Apply_Compile_Time_Constraint_Error | |
1501 | (N, "value not in range of }?", | |
1502 | CE_Overflow_Check_Failed, | |
1503 | Ent => BT); | |
1504 | return; | |
1505 | end if; | |
1506 | end; | |
996ae0b0 RK |
1507 | end if; |
1508 | ||
82c80734 RD |
1509 | -- If we get here we can fold the result |
1510 | ||
fbf5a39b | 1511 | Fold_Uint (N, Result, Stat); |
996ae0b0 RK |
1512 | end; |
1513 | ||
1514 | -- Cases where at least one operand is a real. We handle the cases | |
1515 | -- of both reals, or mixed/real integer cases (the latter happen | |
1516 | -- only for divide and multiply, and the result is always real). | |
1517 | ||
1518 | elsif Is_Real_Type (Ltype) or else Is_Real_Type (Rtype) then | |
1519 | declare | |
1520 | Left_Real : Ureal; | |
1521 | Right_Real : Ureal; | |
1522 | Result : Ureal; | |
1523 | ||
1524 | begin | |
1525 | if Is_Real_Type (Ltype) then | |
1526 | Left_Real := Expr_Value_R (Left); | |
1527 | else | |
1528 | Left_Real := UR_From_Uint (Expr_Value (Left)); | |
1529 | end if; | |
1530 | ||
1531 | if Is_Real_Type (Rtype) then | |
1532 | Right_Real := Expr_Value_R (Right); | |
1533 | else | |
1534 | Right_Real := UR_From_Uint (Expr_Value (Right)); | |
1535 | end if; | |
1536 | ||
1537 | if Nkind (N) = N_Op_Add then | |
1538 | Result := Left_Real + Right_Real; | |
1539 | ||
1540 | elsif Nkind (N) = N_Op_Subtract then | |
1541 | Result := Left_Real - Right_Real; | |
1542 | ||
1543 | elsif Nkind (N) = N_Op_Multiply then | |
1544 | Result := Left_Real * Right_Real; | |
1545 | ||
1546 | else pragma Assert (Nkind (N) = N_Op_Divide); | |
1547 | if UR_Is_Zero (Right_Real) then | |
1548 | Apply_Compile_Time_Constraint_Error | |
07fc65c4 | 1549 | (N, "division by zero", CE_Divide_By_Zero); |
996ae0b0 RK |
1550 | return; |
1551 | end if; | |
1552 | ||
1553 | Result := Left_Real / Right_Real; | |
1554 | end if; | |
1555 | ||
fbf5a39b | 1556 | Fold_Ureal (N, Result, Stat); |
996ae0b0 RK |
1557 | end; |
1558 | end if; | |
996ae0b0 RK |
1559 | end Eval_Arithmetic_Op; |
1560 | ||
1561 | ---------------------------- | |
1562 | -- Eval_Character_Literal -- | |
1563 | ---------------------------- | |
1564 | ||
1565 | -- Nothing to be done! | |
1566 | ||
1567 | procedure Eval_Character_Literal (N : Node_Id) is | |
07fc65c4 | 1568 | pragma Warnings (Off, N); |
996ae0b0 RK |
1569 | begin |
1570 | null; | |
1571 | end Eval_Character_Literal; | |
1572 | ||
c01a9391 AC |
1573 | --------------- |
1574 | -- Eval_Call -- | |
1575 | --------------- | |
1576 | ||
1577 | -- Static function calls are either calls to predefined operators | |
1578 | -- with static arguments, or calls to functions that rename a literal. | |
1579 | -- Only the latter case is handled here, predefined operators are | |
1580 | -- constant-folded elsewhere. | |
29797f34 | 1581 | |
c01a9391 AC |
1582 | -- If the function is itself inherited (see 7423-001) the literal of |
1583 | -- the parent type must be explicitly converted to the return type | |
1584 | -- of the function. | |
1585 | ||
1586 | procedure Eval_Call (N : Node_Id) is | |
1587 | Loc : constant Source_Ptr := Sloc (N); | |
1588 | Typ : constant Entity_Id := Etype (N); | |
1589 | Lit : Entity_Id; | |
1590 | ||
1591 | begin | |
1592 | if Nkind (N) = N_Function_Call | |
1593 | and then No (Parameter_Associations (N)) | |
1594 | and then Is_Entity_Name (Name (N)) | |
1595 | and then Present (Alias (Entity (Name (N)))) | |
1596 | and then Is_Enumeration_Type (Base_Type (Typ)) | |
1597 | then | |
1598 | Lit := Alias (Entity (Name (N))); | |
c01a9391 AC |
1599 | while Present (Alias (Lit)) loop |
1600 | Lit := Alias (Lit); | |
1601 | end loop; | |
1602 | ||
1603 | if Ekind (Lit) = E_Enumeration_Literal then | |
1604 | if Base_Type (Etype (Lit)) /= Base_Type (Typ) then | |
1605 | Rewrite | |
1606 | (N, Convert_To (Typ, New_Occurrence_Of (Lit, Loc))); | |
1607 | else | |
1608 | Rewrite (N, New_Occurrence_Of (Lit, Loc)); | |
1609 | end if; | |
1610 | ||
1611 | Resolve (N, Typ); | |
1612 | end if; | |
1613 | end if; | |
1614 | end Eval_Call; | |
1615 | ||
996ae0b0 RK |
1616 | ------------------------ |
1617 | -- Eval_Concatenation -- | |
1618 | ------------------------ | |
1619 | ||
3996951a TQ |
1620 | -- Concatenation is a static function, so the result is static if both |
1621 | -- operands are static (RM 4.9(7), 4.9(21)). | |
996ae0b0 RK |
1622 | |
1623 | procedure Eval_Concatenation (N : Node_Id) is | |
f91b40db GB |
1624 | Left : constant Node_Id := Left_Opnd (N); |
1625 | Right : constant Node_Id := Right_Opnd (N); | |
1626 | C_Typ : constant Entity_Id := Root_Type (Component_Type (Etype (N))); | |
996ae0b0 RK |
1627 | Stat : Boolean; |
1628 | Fold : Boolean; | |
996ae0b0 RK |
1629 | |
1630 | begin | |
3996951a TQ |
1631 | -- Concatenation is never static in Ada 83, so if Ada 83 check operand |
1632 | -- non-static context. | |
996ae0b0 | 1633 | |
0ab80019 | 1634 | if Ada_Version = Ada_83 |
996ae0b0 RK |
1635 | and then Comes_From_Source (N) |
1636 | then | |
1637 | Check_Non_Static_Context (Left); | |
1638 | Check_Non_Static_Context (Right); | |
1639 | return; | |
1640 | end if; | |
1641 | ||
1642 | -- If not foldable we are done. In principle concatenation that yields | |
1643 | -- any string type is static (i.e. an array type of character types). | |
1644 | -- However, character types can include enumeration literals, and | |
1645 | -- concatenation in that case cannot be described by a literal, so we | |
1646 | -- only consider the operation static if the result is an array of | |
1647 | -- (a descendant of) a predefined character type. | |
1648 | ||
1649 | Test_Expression_Is_Foldable (N, Left, Right, Stat, Fold); | |
1650 | ||
3996951a | 1651 | if not (Is_Standard_Character_Type (C_Typ) and then Fold) then |
996ae0b0 RK |
1652 | Set_Is_Static_Expression (N, False); |
1653 | return; | |
1654 | end if; | |
1655 | ||
82c80734 | 1656 | -- Compile time string concatenation |
996ae0b0 | 1657 | |
3996951a TQ |
1658 | -- ??? Note that operands that are aggregates can be marked as static, |
1659 | -- so we should attempt at a later stage to fold concatenations with | |
1660 | -- such aggregates. | |
996ae0b0 RK |
1661 | |
1662 | declare | |
b54ddf5a BD |
1663 | Left_Str : constant Node_Id := Get_String_Val (Left); |
1664 | Left_Len : Nat; | |
1665 | Right_Str : constant Node_Id := Get_String_Val (Right); | |
1666 | Folded_Val : String_Id; | |
996ae0b0 RK |
1667 | |
1668 | begin | |
1669 | -- Establish new string literal, and store left operand. We make | |
1670 | -- sure to use the special Start_String that takes an operand if | |
1671 | -- the left operand is a string literal. Since this is optimized | |
1672 | -- in the case where that is the most recently created string | |
1673 | -- literal, we ensure efficient time/space behavior for the | |
1674 | -- case of a concatenation of a series of string literals. | |
1675 | ||
1676 | if Nkind (Left_Str) = N_String_Literal then | |
f91b40db | 1677 | Left_Len := String_Length (Strval (Left_Str)); |
b54ddf5a BD |
1678 | |
1679 | -- If the left operand is the empty string, and the right operand | |
1680 | -- is a string literal (the case of "" & "..."), the result is the | |
1681 | -- value of the right operand. This optimization is important when | |
1682 | -- Is_Folded_In_Parser, to avoid copying an enormous right | |
1683 | -- operand. | |
1684 | ||
1685 | if Left_Len = 0 and then Nkind (Right_Str) = N_String_Literal then | |
1686 | Folded_Val := Strval (Right_Str); | |
1687 | else | |
1688 | Start_String (Strval (Left_Str)); | |
1689 | end if; | |
1690 | ||
996ae0b0 RK |
1691 | else |
1692 | Start_String; | |
82c80734 | 1693 | Store_String_Char (UI_To_CC (Char_Literal_Value (Left_Str))); |
f91b40db | 1694 | Left_Len := 1; |
996ae0b0 RK |
1695 | end if; |
1696 | ||
b54ddf5a BD |
1697 | -- Now append the characters of the right operand, unless we |
1698 | -- optimized the "" & "..." case above. | |
996ae0b0 RK |
1699 | |
1700 | if Nkind (Right_Str) = N_String_Literal then | |
b54ddf5a BD |
1701 | if Left_Len /= 0 then |
1702 | Store_String_Chars (Strval (Right_Str)); | |
1703 | Folded_Val := End_String; | |
1704 | end if; | |
996ae0b0 | 1705 | else |
82c80734 | 1706 | Store_String_Char (UI_To_CC (Char_Literal_Value (Right_Str))); |
b54ddf5a | 1707 | Folded_Val := End_String; |
996ae0b0 RK |
1708 | end if; |
1709 | ||
1710 | Set_Is_Static_Expression (N, Stat); | |
1711 | ||
1712 | if Stat then | |
f91b40db GB |
1713 | |
1714 | -- If left operand is the empty string, the result is the | |
1715 | -- right operand, including its bounds if anomalous. | |
1716 | ||
1717 | if Left_Len = 0 | |
1718 | and then Is_Array_Type (Etype (Right)) | |
1719 | and then Etype (Right) /= Any_String | |
1720 | then | |
1721 | Set_Etype (N, Etype (Right)); | |
1722 | end if; | |
1723 | ||
b54ddf5a | 1724 | Fold_Str (N, Folded_Val, Static => True); |
996ae0b0 RK |
1725 | end if; |
1726 | end; | |
1727 | end Eval_Concatenation; | |
1728 | ||
1729 | --------------------------------- | |
1730 | -- Eval_Conditional_Expression -- | |
1731 | --------------------------------- | |
1732 | ||
1733 | -- This GNAT internal construct can never be statically folded, so the | |
1734 | -- only required processing is to do the check for non-static context | |
1735 | -- for the two expression operands. | |
1736 | ||
1737 | procedure Eval_Conditional_Expression (N : Node_Id) is | |
1738 | Condition : constant Node_Id := First (Expressions (N)); | |
1739 | Then_Expr : constant Node_Id := Next (Condition); | |
1740 | Else_Expr : constant Node_Id := Next (Then_Expr); | |
1741 | ||
1742 | begin | |
1743 | Check_Non_Static_Context (Then_Expr); | |
1744 | Check_Non_Static_Context (Else_Expr); | |
1745 | end Eval_Conditional_Expression; | |
1746 | ||
1747 | ---------------------- | |
1748 | -- Eval_Entity_Name -- | |
1749 | ---------------------- | |
1750 | ||
1751 | -- This procedure is used for identifiers and expanded names other than | |
1752 | -- named numbers (see Eval_Named_Integer, Eval_Named_Real. These are | |
1753 | -- static if they denote a static constant (RM 4.9(6)) or if the name | |
1754 | -- denotes an enumeration literal (RM 4.9(22)). | |
1755 | ||
1756 | procedure Eval_Entity_Name (N : Node_Id) is | |
1757 | Def_Id : constant Entity_Id := Entity (N); | |
1758 | Val : Node_Id; | |
1759 | ||
1760 | begin | |
1761 | -- Enumeration literals are always considered to be constants | |
1762 | -- and cannot raise constraint error (RM 4.9(22)). | |
1763 | ||
1764 | if Ekind (Def_Id) = E_Enumeration_Literal then | |
1765 | Set_Is_Static_Expression (N); | |
1766 | return; | |
1767 | ||
1768 | -- A name is static if it denotes a static constant (RM 4.9(5)), and | |
1769 | -- we also copy Raise_Constraint_Error. Notice that even if non-static, | |
1770 | -- it does not violate 10.2.1(8) here, since this is not a variable. | |
1771 | ||
1772 | elsif Ekind (Def_Id) = E_Constant then | |
1773 | ||
1774 | -- Deferred constants must always be treated as nonstatic | |
1775 | -- outside the scope of their full view. | |
1776 | ||
1777 | if Present (Full_View (Def_Id)) | |
1778 | and then not In_Open_Scopes (Scope (Def_Id)) | |
1779 | then | |
1780 | Val := Empty; | |
1781 | else | |
1782 | Val := Constant_Value (Def_Id); | |
1783 | end if; | |
1784 | ||
1785 | if Present (Val) then | |
1786 | Set_Is_Static_Expression | |
1787 | (N, Is_Static_Expression (Val) | |
1788 | and then Is_Static_Subtype (Etype (Def_Id))); | |
1789 | Set_Raises_Constraint_Error (N, Raises_Constraint_Error (Val)); | |
1790 | ||
1791 | if not Is_Static_Expression (N) | |
1792 | and then not Is_Generic_Type (Etype (N)) | |
1793 | then | |
1794 | Validate_Static_Object_Name (N); | |
1795 | end if; | |
1796 | ||
1797 | return; | |
1798 | end if; | |
1799 | end if; | |
1800 | ||
82c80734 | 1801 | -- Fall through if the name is not static |
996ae0b0 RK |
1802 | |
1803 | Validate_Static_Object_Name (N); | |
1804 | end Eval_Entity_Name; | |
1805 | ||
1806 | ---------------------------- | |
1807 | -- Eval_Indexed_Component -- | |
1808 | ---------------------------- | |
1809 | ||
8cbb664e MG |
1810 | -- Indexed components are never static, so we need to perform the check |
1811 | -- for non-static context on the index values. Then, we check if the | |
1812 | -- value can be obtained at compile time, even though it is non-static. | |
996ae0b0 RK |
1813 | |
1814 | procedure Eval_Indexed_Component (N : Node_Id) is | |
1815 | Expr : Node_Id; | |
1816 | ||
1817 | begin | |
fbf5a39b AC |
1818 | -- Check for non-static context on index values |
1819 | ||
996ae0b0 RK |
1820 | Expr := First (Expressions (N)); |
1821 | while Present (Expr) loop | |
1822 | Check_Non_Static_Context (Expr); | |
1823 | Next (Expr); | |
1824 | end loop; | |
1825 | ||
fbf5a39b AC |
1826 | -- If the indexed component appears in an object renaming declaration |
1827 | -- then we do not want to try to evaluate it, since in this case we | |
1828 | -- need the identity of the array element. | |
1829 | ||
1830 | if Nkind (Parent (N)) = N_Object_Renaming_Declaration then | |
1831 | return; | |
1832 | ||
1833 | -- Similarly if the indexed component appears as the prefix of an | |
1834 | -- attribute we don't want to evaluate it, because at least for | |
1835 | -- some cases of attributes we need the identify (e.g. Access, Size) | |
1836 | ||
1837 | elsif Nkind (Parent (N)) = N_Attribute_Reference then | |
1838 | return; | |
1839 | end if; | |
1840 | ||
1841 | -- Note: there are other cases, such as the left side of an assignment, | |
1842 | -- or an OUT parameter for a call, where the replacement results in the | |
1843 | -- illegal use of a constant, But these cases are illegal in the first | |
1844 | -- place, so the replacement, though silly, is harmless. | |
1845 | ||
1846 | -- Now see if this is a constant array reference | |
8cbb664e MG |
1847 | |
1848 | if List_Length (Expressions (N)) = 1 | |
1849 | and then Is_Entity_Name (Prefix (N)) | |
1850 | and then Ekind (Entity (Prefix (N))) = E_Constant | |
1851 | and then Present (Constant_Value (Entity (Prefix (N)))) | |
1852 | then | |
1853 | declare | |
1854 | Loc : constant Source_Ptr := Sloc (N); | |
1855 | Arr : constant Node_Id := Constant_Value (Entity (Prefix (N))); | |
1856 | Sub : constant Node_Id := First (Expressions (N)); | |
1857 | ||
1858 | Atyp : Entity_Id; | |
1859 | -- Type of array | |
1860 | ||
1861 | Lin : Nat; | |
1862 | -- Linear one's origin subscript value for array reference | |
1863 | ||
1864 | Lbd : Node_Id; | |
1865 | -- Lower bound of the first array index | |
1866 | ||
1867 | Elm : Node_Id; | |
1868 | -- Value from constant array | |
1869 | ||
1870 | begin | |
1871 | Atyp := Etype (Arr); | |
1872 | ||
1873 | if Is_Access_Type (Atyp) then | |
1874 | Atyp := Designated_Type (Atyp); | |
1875 | end if; | |
1876 | ||
1877 | -- If we have an array type (we should have but perhaps there | |
1878 | -- are error cases where this is not the case), then see if we | |
1879 | -- can do a constant evaluation of the array reference. | |
1880 | ||
1881 | if Is_Array_Type (Atyp) then | |
1882 | if Ekind (Atyp) = E_String_Literal_Subtype then | |
1883 | Lbd := String_Literal_Low_Bound (Atyp); | |
1884 | else | |
1885 | Lbd := Type_Low_Bound (Etype (First_Index (Atyp))); | |
1886 | end if; | |
1887 | ||
1888 | if Compile_Time_Known_Value (Sub) | |
1889 | and then Nkind (Arr) = N_Aggregate | |
1890 | and then Compile_Time_Known_Value (Lbd) | |
1891 | and then Is_Discrete_Type (Component_Type (Atyp)) | |
1892 | then | |
1893 | Lin := UI_To_Int (Expr_Value (Sub) - Expr_Value (Lbd)) + 1; | |
1894 | ||
1895 | if List_Length (Expressions (Arr)) >= Lin then | |
1896 | Elm := Pick (Expressions (Arr), Lin); | |
1897 | ||
1898 | -- If the resulting expression is compile time known, | |
1899 | -- then we can rewrite the indexed component with this | |
1900 | -- value, being sure to mark the result as non-static. | |
1901 | -- We also reset the Sloc, in case this generates an | |
1902 | -- error later on (e.g. 136'Access). | |
1903 | ||
1904 | if Compile_Time_Known_Value (Elm) then | |
1905 | Rewrite (N, Duplicate_Subexpr_No_Checks (Elm)); | |
1906 | Set_Is_Static_Expression (N, False); | |
1907 | Set_Sloc (N, Loc); | |
1908 | end if; | |
1909 | end if; | |
9fbb3ae6 AC |
1910 | |
1911 | -- We can also constant-fold if the prefix is a string literal. | |
1912 | -- This will be useful in an instantiation or an inlining. | |
1913 | ||
1914 | elsif Compile_Time_Known_Value (Sub) | |
1915 | and then Nkind (Arr) = N_String_Literal | |
1916 | and then Compile_Time_Known_Value (Lbd) | |
1917 | and then Expr_Value (Lbd) = 1 | |
1918 | and then Expr_Value (Sub) <= | |
1919 | String_Literal_Length (Etype (Arr)) | |
1920 | then | |
1921 | declare | |
1922 | C : constant Char_Code := | |
1923 | Get_String_Char (Strval (Arr), | |
1924 | UI_To_Int (Expr_Value (Sub))); | |
1925 | begin | |
1926 | Set_Character_Literal_Name (C); | |
1927 | ||
1928 | Elm := | |
1929 | Make_Character_Literal (Loc, | |
1930 | Chars => Name_Find, | |
1931 | Char_Literal_Value => UI_From_CC (C)); | |
1932 | Set_Etype (Elm, Component_Type (Atyp)); | |
1933 | Rewrite (N, Duplicate_Subexpr_No_Checks (Elm)); | |
1934 | Set_Is_Static_Expression (N, False); | |
1935 | end; | |
8cbb664e MG |
1936 | end if; |
1937 | end if; | |
1938 | end; | |
1939 | end if; | |
996ae0b0 RK |
1940 | end Eval_Indexed_Component; |
1941 | ||
1942 | -------------------------- | |
1943 | -- Eval_Integer_Literal -- | |
1944 | -------------------------- | |
1945 | ||
1946 | -- Numeric literals are static (RM 4.9(1)), and have already been marked | |
1947 | -- as static by the analyzer. The reason we did it that early is to allow | |
1948 | -- the possibility of turning off the Is_Static_Expression flag after | |
1949 | -- analysis, but before resolution, when integer literals are generated | |
1950 | -- in the expander that do not correspond to static expressions. | |
1951 | ||
1952 | procedure Eval_Integer_Literal (N : Node_Id) is | |
1953 | T : constant Entity_Id := Etype (N); | |
1954 | ||
5d09245e AC |
1955 | function In_Any_Integer_Context return Boolean; |
1956 | -- If the literal is resolved with a specific type in a context | |
1957 | -- where the expected type is Any_Integer, there are no range checks | |
1958 | -- on the literal. By the time the literal is evaluated, it carries | |
1959 | -- the type imposed by the enclosing expression, and we must recover | |
1960 | -- the context to determine that Any_Integer is meant. | |
1961 | ||
1962 | ---------------------------- | |
1963 | -- To_Any_Integer_Context -- | |
1964 | ---------------------------- | |
1965 | ||
1966 | function In_Any_Integer_Context return Boolean is | |
1967 | Par : constant Node_Id := Parent (N); | |
1968 | K : constant Node_Kind := Nkind (Par); | |
1969 | ||
1970 | begin | |
1971 | -- Any_Integer also appears in digits specifications for real types, | |
1972 | -- but those have bounds smaller that those of any integer base | |
1973 | -- type, so we can safely ignore these cases. | |
1974 | ||
1975 | return K = N_Number_Declaration | |
1976 | or else K = N_Attribute_Reference | |
1977 | or else K = N_Attribute_Definition_Clause | |
1978 | or else K = N_Modular_Type_Definition | |
1979 | or else K = N_Signed_Integer_Type_Definition; | |
1980 | end In_Any_Integer_Context; | |
1981 | ||
1982 | -- Start of processing for Eval_Integer_Literal | |
1983 | ||
996ae0b0 | 1984 | begin |
5d09245e | 1985 | |
996ae0b0 RK |
1986 | -- If the literal appears in a non-expression context, then it is |
1987 | -- certainly appearing in a non-static context, so check it. This | |
1988 | -- is actually a redundant check, since Check_Non_Static_Context | |
1989 | -- would check it, but it seems worth while avoiding the call. | |
1990 | ||
5d09245e AC |
1991 | if Nkind (Parent (N)) not in N_Subexpr |
1992 | and then not In_Any_Integer_Context | |
1993 | then | |
996ae0b0 RK |
1994 | Check_Non_Static_Context (N); |
1995 | end if; | |
1996 | ||
1997 | -- Modular integer literals must be in their base range | |
1998 | ||
1999 | if Is_Modular_Integer_Type (T) | |
c800f862 | 2000 | and then Is_Out_Of_Range (N, Base_Type (T), Assume_Valid => True) |
996ae0b0 RK |
2001 | then |
2002 | Out_Of_Range (N); | |
2003 | end if; | |
2004 | end Eval_Integer_Literal; | |
2005 | ||
2006 | --------------------- | |
2007 | -- Eval_Logical_Op -- | |
2008 | --------------------- | |
2009 | ||
2010 | -- Logical operations are static functions, so the result is potentially | |
2011 | -- static if both operands are potentially static (RM 4.9(7), 4.9(20)). | |
2012 | ||
2013 | procedure Eval_Logical_Op (N : Node_Id) is | |
2014 | Left : constant Node_Id := Left_Opnd (N); | |
2015 | Right : constant Node_Id := Right_Opnd (N); | |
2016 | Stat : Boolean; | |
2017 | Fold : Boolean; | |
2018 | ||
2019 | begin | |
2020 | -- If not foldable we are done | |
2021 | ||
2022 | Test_Expression_Is_Foldable (N, Left, Right, Stat, Fold); | |
2023 | ||
2024 | if not Fold then | |
2025 | return; | |
2026 | end if; | |
2027 | ||
2028 | -- Compile time evaluation of logical operation | |
2029 | ||
2030 | declare | |
2031 | Left_Int : constant Uint := Expr_Value (Left); | |
2032 | Right_Int : constant Uint := Expr_Value (Right); | |
2033 | ||
2034 | begin | |
2035 | if Is_Modular_Integer_Type (Etype (N)) then | |
2036 | declare | |
2037 | Left_Bits : Bits (0 .. UI_To_Int (Esize (Etype (N))) - 1); | |
2038 | Right_Bits : Bits (0 .. UI_To_Int (Esize (Etype (N))) - 1); | |
2039 | ||
2040 | begin | |
2041 | To_Bits (Left_Int, Left_Bits); | |
2042 | To_Bits (Right_Int, Right_Bits); | |
2043 | ||
2044 | -- Note: should really be able to use array ops instead of | |
2045 | -- these loops, but they weren't working at the time ??? | |
2046 | ||
2047 | if Nkind (N) = N_Op_And then | |
2048 | for J in Left_Bits'Range loop | |
2049 | Left_Bits (J) := Left_Bits (J) and Right_Bits (J); | |
2050 | end loop; | |
2051 | ||
2052 | elsif Nkind (N) = N_Op_Or then | |
2053 | for J in Left_Bits'Range loop | |
2054 | Left_Bits (J) := Left_Bits (J) or Right_Bits (J); | |
2055 | end loop; | |
2056 | ||
2057 | else | |
2058 | pragma Assert (Nkind (N) = N_Op_Xor); | |
2059 | ||
2060 | for J in Left_Bits'Range loop | |
2061 | Left_Bits (J) := Left_Bits (J) xor Right_Bits (J); | |
2062 | end loop; | |
2063 | end if; | |
2064 | ||
fbf5a39b | 2065 | Fold_Uint (N, From_Bits (Left_Bits, Etype (N)), Stat); |
996ae0b0 RK |
2066 | end; |
2067 | ||
2068 | else | |
2069 | pragma Assert (Is_Boolean_Type (Etype (N))); | |
2070 | ||
2071 | if Nkind (N) = N_Op_And then | |
2072 | Fold_Uint (N, | |
fbf5a39b | 2073 | Test (Is_True (Left_Int) and then Is_True (Right_Int)), Stat); |
996ae0b0 RK |
2074 | |
2075 | elsif Nkind (N) = N_Op_Or then | |
2076 | Fold_Uint (N, | |
fbf5a39b | 2077 | Test (Is_True (Left_Int) or else Is_True (Right_Int)), Stat); |
996ae0b0 RK |
2078 | |
2079 | else | |
2080 | pragma Assert (Nkind (N) = N_Op_Xor); | |
2081 | Fold_Uint (N, | |
fbf5a39b | 2082 | Test (Is_True (Left_Int) xor Is_True (Right_Int)), Stat); |
996ae0b0 RK |
2083 | end if; |
2084 | end if; | |
996ae0b0 RK |
2085 | end; |
2086 | end Eval_Logical_Op; | |
2087 | ||
2088 | ------------------------ | |
2089 | -- Eval_Membership_Op -- | |
2090 | ------------------------ | |
2091 | ||
2092 | -- A membership test is potentially static if the expression is static, | |
2093 | -- and the range is a potentially static range, or is a subtype mark | |
2094 | -- denoting a static subtype (RM 4.9(12)). | |
2095 | ||
2096 | procedure Eval_Membership_Op (N : Node_Id) is | |
2097 | Left : constant Node_Id := Left_Opnd (N); | |
2098 | Right : constant Node_Id := Right_Opnd (N); | |
2099 | Def_Id : Entity_Id; | |
2100 | Lo : Node_Id; | |
2101 | Hi : Node_Id; | |
2102 | Result : Boolean; | |
2103 | Stat : Boolean; | |
2104 | Fold : Boolean; | |
2105 | ||
2106 | begin | |
2107 | -- Ignore if error in either operand, except to make sure that | |
2108 | -- Any_Type is properly propagated to avoid junk cascaded errors. | |
2109 | ||
2110 | if Etype (Left) = Any_Type | |
2111 | or else Etype (Right) = Any_Type | |
2112 | then | |
2113 | Set_Etype (N, Any_Type); | |
2114 | return; | |
2115 | end if; | |
2116 | ||
2117 | -- Case of right operand is a subtype name | |
2118 | ||
2119 | if Is_Entity_Name (Right) then | |
2120 | Def_Id := Entity (Right); | |
2121 | ||
2122 | if (Is_Scalar_Type (Def_Id) or else Is_String_Type (Def_Id)) | |
2123 | and then Is_OK_Static_Subtype (Def_Id) | |
2124 | then | |
2125 | Test_Expression_Is_Foldable (N, Left, Stat, Fold); | |
2126 | ||
2127 | if not Fold or else not Stat then | |
2128 | return; | |
2129 | end if; | |
2130 | else | |
2131 | Check_Non_Static_Context (Left); | |
2132 | return; | |
2133 | end if; | |
2134 | ||
2135 | -- For string membership tests we will check the length | |
2136 | -- further below. | |
2137 | ||
2138 | if not Is_String_Type (Def_Id) then | |
2139 | Lo := Type_Low_Bound (Def_Id); | |
2140 | Hi := Type_High_Bound (Def_Id); | |
2141 | ||
2142 | else | |
2143 | Lo := Empty; | |
2144 | Hi := Empty; | |
2145 | end if; | |
2146 | ||
2147 | -- Case of right operand is a range | |
2148 | ||
2149 | else | |
2150 | if Is_Static_Range (Right) then | |
2151 | Test_Expression_Is_Foldable (N, Left, Stat, Fold); | |
2152 | ||
2153 | if not Fold or else not Stat then | |
2154 | return; | |
2155 | ||
2156 | -- If one bound of range raises CE, then don't try to fold | |
2157 | ||
2158 | elsif not Is_OK_Static_Range (Right) then | |
2159 | Check_Non_Static_Context (Left); | |
2160 | return; | |
2161 | end if; | |
2162 | ||
2163 | else | |
2164 | Check_Non_Static_Context (Left); | |
2165 | return; | |
2166 | end if; | |
2167 | ||
2168 | -- Here we know range is an OK static range | |
2169 | ||
2170 | Lo := Low_Bound (Right); | |
2171 | Hi := High_Bound (Right); | |
2172 | end if; | |
2173 | ||
2174 | -- For strings we check that the length of the string expression is | |
2175 | -- compatible with the string subtype if the subtype is constrained, | |
2176 | -- or if unconstrained then the test is always true. | |
2177 | ||
2178 | if Is_String_Type (Etype (Right)) then | |
2179 | if not Is_Constrained (Etype (Right)) then | |
2180 | Result := True; | |
2181 | ||
2182 | else | |
2183 | declare | |
2184 | Typlen : constant Uint := String_Type_Len (Etype (Right)); | |
2185 | Strlen : constant Uint := | |
2186 | UI_From_Int (String_Length (Strval (Get_String_Val (Left)))); | |
2187 | begin | |
2188 | Result := (Typlen = Strlen); | |
2189 | end; | |
2190 | end if; | |
2191 | ||
2192 | -- Fold the membership test. We know we have a static range and Lo | |
2193 | -- and Hi are set to the expressions for the end points of this range. | |
2194 | ||
2195 | elsif Is_Real_Type (Etype (Right)) then | |
2196 | declare | |
2197 | Leftval : constant Ureal := Expr_Value_R (Left); | |
2198 | ||
2199 | begin | |
2200 | Result := Expr_Value_R (Lo) <= Leftval | |
2201 | and then Leftval <= Expr_Value_R (Hi); | |
2202 | end; | |
2203 | ||
2204 | else | |
2205 | declare | |
2206 | Leftval : constant Uint := Expr_Value (Left); | |
2207 | ||
2208 | begin | |
2209 | Result := Expr_Value (Lo) <= Leftval | |
2210 | and then Leftval <= Expr_Value (Hi); | |
2211 | end; | |
2212 | end if; | |
2213 | ||
2214 | if Nkind (N) = N_Not_In then | |
2215 | Result := not Result; | |
2216 | end if; | |
2217 | ||
fbf5a39b | 2218 | Fold_Uint (N, Test (Result), True); |
996ae0b0 | 2219 | Warn_On_Known_Condition (N); |
996ae0b0 RK |
2220 | end Eval_Membership_Op; |
2221 | ||
2222 | ------------------------ | |
2223 | -- Eval_Named_Integer -- | |
2224 | ------------------------ | |
2225 | ||
2226 | procedure Eval_Named_Integer (N : Node_Id) is | |
2227 | begin | |
2228 | Fold_Uint (N, | |
fbf5a39b | 2229 | Expr_Value (Expression (Declaration_Node (Entity (N)))), True); |
996ae0b0 RK |
2230 | end Eval_Named_Integer; |
2231 | ||
2232 | --------------------- | |
2233 | -- Eval_Named_Real -- | |
2234 | --------------------- | |
2235 | ||
2236 | procedure Eval_Named_Real (N : Node_Id) is | |
2237 | begin | |
2238 | Fold_Ureal (N, | |
fbf5a39b | 2239 | Expr_Value_R (Expression (Declaration_Node (Entity (N)))), True); |
996ae0b0 RK |
2240 | end Eval_Named_Real; |
2241 | ||
2242 | ------------------- | |
2243 | -- Eval_Op_Expon -- | |
2244 | ------------------- | |
2245 | ||
2246 | -- Exponentiation is a static functions, so the result is potentially | |
2247 | -- static if both operands are potentially static (RM 4.9(7), 4.9(20)). | |
2248 | ||
2249 | procedure Eval_Op_Expon (N : Node_Id) is | |
2250 | Left : constant Node_Id := Left_Opnd (N); | |
2251 | Right : constant Node_Id := Right_Opnd (N); | |
2252 | Stat : Boolean; | |
2253 | Fold : Boolean; | |
2254 | ||
2255 | begin | |
2256 | -- If not foldable we are done | |
2257 | ||
2258 | Test_Expression_Is_Foldable (N, Left, Right, Stat, Fold); | |
2259 | ||
2260 | if not Fold then | |
2261 | return; | |
2262 | end if; | |
2263 | ||
2264 | -- Fold exponentiation operation | |
2265 | ||
2266 | declare | |
2267 | Right_Int : constant Uint := Expr_Value (Right); | |
2268 | ||
2269 | begin | |
2270 | -- Integer case | |
2271 | ||
2272 | if Is_Integer_Type (Etype (Left)) then | |
2273 | declare | |
2274 | Left_Int : constant Uint := Expr_Value (Left); | |
2275 | Result : Uint; | |
2276 | ||
2277 | begin | |
2278 | -- Exponentiation of an integer raises the exception | |
2279 | -- Constraint_Error for a negative exponent (RM 4.5.6) | |
2280 | ||
2281 | if Right_Int < 0 then | |
2282 | Apply_Compile_Time_Constraint_Error | |
fbf5a39b AC |
2283 | (N, "integer exponent negative", |
2284 | CE_Range_Check_Failed, | |
2285 | Warn => not Stat); | |
996ae0b0 RK |
2286 | return; |
2287 | ||
2288 | else | |
2289 | if OK_Bits (N, Num_Bits (Left_Int) * Right_Int) then | |
2290 | Result := Left_Int ** Right_Int; | |
2291 | else | |
2292 | Result := Left_Int; | |
2293 | end if; | |
2294 | ||
2295 | if Is_Modular_Integer_Type (Etype (N)) then | |
2296 | Result := Result mod Modulus (Etype (N)); | |
2297 | end if; | |
2298 | ||
fbf5a39b | 2299 | Fold_Uint (N, Result, Stat); |
996ae0b0 RK |
2300 | end if; |
2301 | end; | |
2302 | ||
2303 | -- Real case | |
2304 | ||
2305 | else | |
2306 | declare | |
2307 | Left_Real : constant Ureal := Expr_Value_R (Left); | |
2308 | ||
2309 | begin | |
2310 | -- Cannot have a zero base with a negative exponent | |
2311 | ||
2312 | if UR_Is_Zero (Left_Real) then | |
2313 | ||
2314 | if Right_Int < 0 then | |
2315 | Apply_Compile_Time_Constraint_Error | |
fbf5a39b AC |
2316 | (N, "zero ** negative integer", |
2317 | CE_Range_Check_Failed, | |
2318 | Warn => not Stat); | |
996ae0b0 RK |
2319 | return; |
2320 | else | |
fbf5a39b | 2321 | Fold_Ureal (N, Ureal_0, Stat); |
996ae0b0 RK |
2322 | end if; |
2323 | ||
2324 | else | |
fbf5a39b | 2325 | Fold_Ureal (N, Left_Real ** Right_Int, Stat); |
996ae0b0 RK |
2326 | end if; |
2327 | end; | |
2328 | end if; | |
996ae0b0 RK |
2329 | end; |
2330 | end Eval_Op_Expon; | |
2331 | ||
2332 | ----------------- | |
2333 | -- Eval_Op_Not -- | |
2334 | ----------------- | |
2335 | ||
2336 | -- The not operation is a static functions, so the result is potentially | |
2337 | -- static if the operand is potentially static (RM 4.9(7), 4.9(20)). | |
2338 | ||
2339 | procedure Eval_Op_Not (N : Node_Id) is | |
2340 | Right : constant Node_Id := Right_Opnd (N); | |
2341 | Stat : Boolean; | |
2342 | Fold : Boolean; | |
2343 | ||
2344 | begin | |
2345 | -- If not foldable we are done | |
2346 | ||
2347 | Test_Expression_Is_Foldable (N, Right, Stat, Fold); | |
2348 | ||
2349 | if not Fold then | |
2350 | return; | |
2351 | end if; | |
2352 | ||
2353 | -- Fold not operation | |
2354 | ||
2355 | declare | |
2356 | Rint : constant Uint := Expr_Value (Right); | |
2357 | Typ : constant Entity_Id := Etype (N); | |
2358 | ||
2359 | begin | |
2360 | -- Negation is equivalent to subtracting from the modulus minus | |
2361 | -- one. For a binary modulus this is equivalent to the ones- | |
2362 | -- component of the original value. For non-binary modulus this | |
2363 | -- is an arbitrary but consistent definition. | |
2364 | ||
2365 | if Is_Modular_Integer_Type (Typ) then | |
fbf5a39b | 2366 | Fold_Uint (N, Modulus (Typ) - 1 - Rint, Stat); |
996ae0b0 RK |
2367 | |
2368 | else | |
2369 | pragma Assert (Is_Boolean_Type (Typ)); | |
fbf5a39b | 2370 | Fold_Uint (N, Test (not Is_True (Rint)), Stat); |
996ae0b0 RK |
2371 | end if; |
2372 | ||
2373 | Set_Is_Static_Expression (N, Stat); | |
2374 | end; | |
2375 | end Eval_Op_Not; | |
2376 | ||
2377 | ------------------------------- | |
2378 | -- Eval_Qualified_Expression -- | |
2379 | ------------------------------- | |
2380 | ||
2381 | -- A qualified expression is potentially static if its subtype mark denotes | |
2382 | -- a static subtype and its expression is potentially static (RM 4.9 (11)). | |
2383 | ||
2384 | procedure Eval_Qualified_Expression (N : Node_Id) is | |
2385 | Operand : constant Node_Id := Expression (N); | |
2386 | Target_Type : constant Entity_Id := Entity (Subtype_Mark (N)); | |
2387 | ||
07fc65c4 GB |
2388 | Stat : Boolean; |
2389 | Fold : Boolean; | |
2390 | Hex : Boolean; | |
996ae0b0 RK |
2391 | |
2392 | begin | |
2393 | -- Can only fold if target is string or scalar and subtype is static | |
2394 | -- Also, do not fold if our parent is an allocator (this is because | |
2395 | -- the qualified expression is really part of the syntactic structure | |
2396 | -- of an allocator, and we do not want to end up with something that | |
2397 | -- corresponds to "new 1" where the 1 is the result of folding a | |
2398 | -- qualified expression). | |
2399 | ||
2400 | if not Is_Static_Subtype (Target_Type) | |
2401 | or else Nkind (Parent (N)) = N_Allocator | |
2402 | then | |
2403 | Check_Non_Static_Context (Operand); | |
af152989 AC |
2404 | |
2405 | -- If operand is known to raise constraint_error, set the | |
2406 | -- flag on the expression so it does not get optimized away. | |
2407 | ||
2408 | if Nkind (Operand) = N_Raise_Constraint_Error then | |
2409 | Set_Raises_Constraint_Error (N); | |
2410 | end if; | |
7324bf49 | 2411 | |
996ae0b0 RK |
2412 | return; |
2413 | end if; | |
2414 | ||
2415 | -- If not foldable we are done | |
2416 | ||
2417 | Test_Expression_Is_Foldable (N, Operand, Stat, Fold); | |
2418 | ||
2419 | if not Fold then | |
2420 | return; | |
2421 | ||
2422 | -- Don't try fold if target type has constraint error bounds | |
2423 | ||
2424 | elsif not Is_OK_Static_Subtype (Target_Type) then | |
2425 | Set_Raises_Constraint_Error (N); | |
2426 | return; | |
2427 | end if; | |
2428 | ||
07fc65c4 GB |
2429 | -- Here we will fold, save Print_In_Hex indication |
2430 | ||
2431 | Hex := Nkind (Operand) = N_Integer_Literal | |
2432 | and then Print_In_Hex (Operand); | |
2433 | ||
996ae0b0 RK |
2434 | -- Fold the result of qualification |
2435 | ||
2436 | if Is_Discrete_Type (Target_Type) then | |
fbf5a39b | 2437 | Fold_Uint (N, Expr_Value (Operand), Stat); |
996ae0b0 | 2438 | |
07fc65c4 GB |
2439 | -- Preserve Print_In_Hex indication |
2440 | ||
2441 | if Hex and then Nkind (N) = N_Integer_Literal then | |
2442 | Set_Print_In_Hex (N); | |
2443 | end if; | |
2444 | ||
996ae0b0 | 2445 | elsif Is_Real_Type (Target_Type) then |
fbf5a39b | 2446 | Fold_Ureal (N, Expr_Value_R (Operand), Stat); |
996ae0b0 RK |
2447 | |
2448 | else | |
fbf5a39b | 2449 | Fold_Str (N, Strval (Get_String_Val (Operand)), Stat); |
996ae0b0 RK |
2450 | |
2451 | if not Stat then | |
2452 | Set_Is_Static_Expression (N, False); | |
2453 | else | |
2454 | Check_String_Literal_Length (N, Target_Type); | |
2455 | end if; | |
2456 | ||
2457 | return; | |
2458 | end if; | |
2459 | ||
fbf5a39b AC |
2460 | -- The expression may be foldable but not static |
2461 | ||
2462 | Set_Is_Static_Expression (N, Stat); | |
2463 | ||
c800f862 | 2464 | if Is_Out_Of_Range (N, Etype (N), Assume_Valid => True) then |
996ae0b0 RK |
2465 | Out_Of_Range (N); |
2466 | end if; | |
996ae0b0 RK |
2467 | end Eval_Qualified_Expression; |
2468 | ||
2469 | ----------------------- | |
2470 | -- Eval_Real_Literal -- | |
2471 | ----------------------- | |
2472 | ||
2473 | -- Numeric literals are static (RM 4.9(1)), and have already been marked | |
2474 | -- as static by the analyzer. The reason we did it that early is to allow | |
2475 | -- the possibility of turning off the Is_Static_Expression flag after | |
2476 | -- analysis, but before resolution, when integer literals are generated | |
2477 | -- in the expander that do not correspond to static expressions. | |
2478 | ||
2479 | procedure Eval_Real_Literal (N : Node_Id) is | |
a1980be8 GB |
2480 | PK : constant Node_Kind := Nkind (Parent (N)); |
2481 | ||
996ae0b0 | 2482 | begin |
a1980be8 GB |
2483 | -- If the literal appears in a non-expression context |
2484 | -- and not as part of a number declaration, then it is | |
2485 | -- appearing in a non-static context, so check it. | |
996ae0b0 | 2486 | |
a1980be8 | 2487 | if PK not in N_Subexpr and then PK /= N_Number_Declaration then |
996ae0b0 RK |
2488 | Check_Non_Static_Context (N); |
2489 | end if; | |
996ae0b0 RK |
2490 | end Eval_Real_Literal; |
2491 | ||
2492 | ------------------------ | |
2493 | -- Eval_Relational_Op -- | |
2494 | ------------------------ | |
2495 | ||
2496 | -- Relational operations are static functions, so the result is static | |
93c3fca7 AC |
2497 | -- if both operands are static (RM 4.9(7), 4.9(20)), except that for |
2498 | -- strings, the result is never static, even if the operands are. | |
996ae0b0 RK |
2499 | |
2500 | procedure Eval_Relational_Op (N : Node_Id) is | |
2501 | Left : constant Node_Id := Left_Opnd (N); | |
2502 | Right : constant Node_Id := Right_Opnd (N); | |
2503 | Typ : constant Entity_Id := Etype (Left); | |
2504 | Result : Boolean; | |
2505 | Stat : Boolean; | |
2506 | Fold : Boolean; | |
2507 | ||
2508 | begin | |
45fc7ddb HK |
2509 | -- One special case to deal with first. If we can tell that the result |
2510 | -- will be false because the lengths of one or more index subtypes are | |
2511 | -- compile time known and different, then we can replace the entire | |
2512 | -- result by False. We only do this for one dimensional arrays, because | |
2513 | -- the case of multi-dimensional arrays is rare and too much trouble! If | |
2514 | -- one of the operands is an illegal aggregate, its type might still be | |
2515 | -- an arbitrary composite type, so nothing to do. | |
996ae0b0 RK |
2516 | |
2517 | if Is_Array_Type (Typ) | |
13f34a3f | 2518 | and then Typ /= Any_Composite |
996ae0b0 | 2519 | and then Number_Dimensions (Typ) = 1 |
13f34a3f | 2520 | and then (Nkind (N) = N_Op_Eq or else Nkind (N) = N_Op_Ne) |
996ae0b0 RK |
2521 | then |
2522 | if Raises_Constraint_Error (Left) | |
2523 | or else Raises_Constraint_Error (Right) | |
2524 | then | |
2525 | return; | |
2526 | end if; | |
2527 | ||
45fc7ddb HK |
2528 | -- OK, we have the case where we may be able to do this fold |
2529 | ||
2530 | Length_Mismatch : declare | |
996ae0b0 | 2531 | procedure Get_Static_Length (Op : Node_Id; Len : out Uint); |
13f34a3f RD |
2532 | -- If Op is an expression for a constrained array with a known |
2533 | -- at compile time length, then Len is set to this (non-negative | |
2534 | -- length). Otherwise Len is set to minus 1. | |
996ae0b0 | 2535 | |
fbf5a39b AC |
2536 | ----------------------- |
2537 | -- Get_Static_Length -- | |
2538 | ----------------------- | |
2539 | ||
996ae0b0 RK |
2540 | procedure Get_Static_Length (Op : Node_Id; Len : out Uint) is |
2541 | T : Entity_Id; | |
2542 | ||
2543 | begin | |
45fc7ddb HK |
2544 | -- First easy case string literal |
2545 | ||
996ae0b0 RK |
2546 | if Nkind (Op) = N_String_Literal then |
2547 | Len := UI_From_Int (String_Length (Strval (Op))); | |
45fc7ddb HK |
2548 | return; |
2549 | end if; | |
2550 | ||
2551 | -- Second easy case, not constrained subtype, so no length | |
996ae0b0 | 2552 | |
45fc7ddb | 2553 | if not Is_Constrained (Etype (Op)) then |
996ae0b0 | 2554 | Len := Uint_Minus_1; |
45fc7ddb HK |
2555 | return; |
2556 | end if; | |
996ae0b0 | 2557 | |
45fc7ddb HK |
2558 | -- General case |
2559 | ||
2560 | T := Etype (First_Index (Etype (Op))); | |
2561 | ||
2562 | -- The simple case, both bounds are known at compile time | |
2563 | ||
2564 | if Is_Discrete_Type (T) | |
2565 | and then | |
2566 | Compile_Time_Known_Value (Type_Low_Bound (T)) | |
2567 | and then | |
2568 | Compile_Time_Known_Value (Type_High_Bound (T)) | |
2569 | then | |
2570 | Len := UI_Max (Uint_0, | |
2571 | Expr_Value (Type_High_Bound (T)) - | |
2572 | Expr_Value (Type_Low_Bound (T)) + 1); | |
2573 | return; | |
2574 | end if; | |
2575 | ||
2576 | -- A more complex case, where the bounds are of the form | |
2577 | -- X [+/- K1] .. X [+/- K2]), where X is an expression that is | |
2578 | -- either A'First or A'Last (with A an entity name), or X is an | |
2579 | -- entity name, and the two X's are the same and K1 and K2 are | |
2580 | -- known at compile time, in this case, the length can also be | |
2581 | -- computed at compile time, even though the bounds are not | |
2582 | -- known. A common case of this is e.g. (X'First..X'First+5). | |
2583 | ||
2584 | Extract_Length : declare | |
2585 | procedure Decompose_Expr | |
2586 | (Expr : Node_Id; | |
2587 | Ent : out Entity_Id; | |
2588 | Kind : out Character; | |
2589 | Cons : out Uint); | |
2590 | -- Given an expression, see if is of the form above, | |
2591 | -- X [+/- K]. If so Ent is set to the entity in X, | |
2592 | -- Kind is 'F','L','E' for 'First/'Last/simple entity, | |
2593 | -- and Cons is the value of K. If the expression is | |
2594 | -- not of the required form, Ent is set to Empty. | |
2595 | ||
2596 | -------------------- | |
2597 | -- Decompose_Expr -- | |
2598 | -------------------- | |
2599 | ||
2600 | procedure Decompose_Expr | |
2601 | (Expr : Node_Id; | |
2602 | Ent : out Entity_Id; | |
2603 | Kind : out Character; | |
2604 | Cons : out Uint) | |
2605 | is | |
2606 | Exp : Node_Id; | |
2607 | ||
2608 | begin | |
2609 | if Nkind (Expr) = N_Op_Add | |
2610 | and then Compile_Time_Known_Value (Right_Opnd (Expr)) | |
2611 | then | |
2612 | Exp := Left_Opnd (Expr); | |
2613 | Cons := Expr_Value (Right_Opnd (Expr)); | |
2614 | ||
2615 | elsif Nkind (Expr) = N_Op_Subtract | |
2616 | and then Compile_Time_Known_Value (Right_Opnd (Expr)) | |
2617 | then | |
2618 | Exp := Left_Opnd (Expr); | |
2619 | Cons := -Expr_Value (Right_Opnd (Expr)); | |
996ae0b0 | 2620 | |
45fc7ddb HK |
2621 | else |
2622 | Exp := Expr; | |
2623 | Cons := Uint_0; | |
2624 | end if; | |
2625 | ||
2626 | -- At this stage Exp is set to the potential X | |
2627 | ||
2628 | if Nkind (Exp) = N_Attribute_Reference then | |
2629 | if Attribute_Name (Exp) = Name_First then | |
2630 | Kind := 'F'; | |
2631 | elsif Attribute_Name (Exp) = Name_Last then | |
2632 | Kind := 'L'; | |
2633 | else | |
2634 | Ent := Empty; | |
2635 | return; | |
2636 | end if; | |
2637 | ||
2638 | Exp := Prefix (Exp); | |
2639 | ||
2640 | else | |
2641 | Kind := 'E'; | |
2642 | end if; | |
2643 | ||
2644 | if Is_Entity_Name (Exp) | |
2645 | and then Present (Entity (Exp)) | |
2646 | then | |
2647 | Ent := Entity (Exp); | |
2648 | else | |
2649 | Ent := Empty; | |
2650 | end if; | |
2651 | end Decompose_Expr; | |
2652 | ||
2653 | -- Local Variables | |
2654 | ||
2655 | Ent1, Ent2 : Entity_Id; | |
2656 | Kind1, Kind2 : Character; | |
2657 | Cons1, Cons2 : Uint; | |
2658 | ||
2659 | -- Start of processing for Extract_Length | |
2660 | ||
2661 | begin | |
bafc9e1d AC |
2662 | Decompose_Expr |
2663 | (Original_Node (Type_Low_Bound (T)), Ent1, Kind1, Cons1); | |
2664 | Decompose_Expr | |
2665 | (Original_Node (Type_High_Bound (T)), Ent2, Kind2, Cons2); | |
45fc7ddb HK |
2666 | |
2667 | if Present (Ent1) | |
2668 | and then Kind1 = Kind2 | |
2669 | and then Ent1 = Ent2 | |
996ae0b0 | 2670 | then |
45fc7ddb | 2671 | Len := Cons2 - Cons1 + 1; |
996ae0b0 RK |
2672 | else |
2673 | Len := Uint_Minus_1; | |
2674 | end if; | |
45fc7ddb | 2675 | end Extract_Length; |
996ae0b0 RK |
2676 | end Get_Static_Length; |
2677 | ||
45fc7ddb HK |
2678 | -- Local Variables |
2679 | ||
996ae0b0 RK |
2680 | Len_L : Uint; |
2681 | Len_R : Uint; | |
2682 | ||
45fc7ddb HK |
2683 | -- Start of processing for Length_Mismatch |
2684 | ||
996ae0b0 RK |
2685 | begin |
2686 | Get_Static_Length (Left, Len_L); | |
2687 | Get_Static_Length (Right, Len_R); | |
2688 | ||
2689 | if Len_L /= Uint_Minus_1 | |
2690 | and then Len_R /= Uint_Minus_1 | |
2691 | and then Len_L /= Len_R | |
2692 | then | |
fbf5a39b | 2693 | Fold_Uint (N, Test (Nkind (N) = N_Op_Ne), False); |
996ae0b0 RK |
2694 | Warn_On_Known_Condition (N); |
2695 | return; | |
2696 | end if; | |
45fc7ddb HK |
2697 | end Length_Mismatch; |
2698 | end if; | |
6eaf4095 | 2699 | |
93c3fca7 | 2700 | -- Test for expression being foldable |
7a3f77d2 | 2701 | |
93c3fca7 | 2702 | Test_Expression_Is_Foldable (N, Left, Right, Stat, Fold); |
996ae0b0 | 2703 | |
93c3fca7 AC |
2704 | -- Only comparisons of scalars can give static results. In particular, |
2705 | -- comparisons of strings never yield a static result, even if both | |
2706 | -- operands are static strings. | |
996ae0b0 RK |
2707 | |
2708 | if not Is_Scalar_Type (Typ) then | |
93c3fca7 AC |
2709 | Stat := False; |
2710 | Set_Is_Static_Expression (N, False); | |
996ae0b0 RK |
2711 | end if; |
2712 | ||
93c3fca7 AC |
2713 | -- For static real type expressions, we cannot use Compile_Time_Compare |
2714 | -- since it worries about run-time results which are not exact. | |
996ae0b0 | 2715 | |
93c3fca7 | 2716 | if Stat and then Is_Real_Type (Typ) then |
996ae0b0 | 2717 | declare |
93c3fca7 AC |
2718 | Left_Real : constant Ureal := Expr_Value_R (Left); |
2719 | Right_Real : constant Ureal := Expr_Value_R (Right); | |
996ae0b0 RK |
2720 | |
2721 | begin | |
2722 | case Nkind (N) is | |
93c3fca7 AC |
2723 | when N_Op_Eq => Result := (Left_Real = Right_Real); |
2724 | when N_Op_Ne => Result := (Left_Real /= Right_Real); | |
2725 | when N_Op_Lt => Result := (Left_Real < Right_Real); | |
2726 | when N_Op_Le => Result := (Left_Real <= Right_Real); | |
2727 | when N_Op_Gt => Result := (Left_Real > Right_Real); | |
2728 | when N_Op_Ge => Result := (Left_Real >= Right_Real); | |
996ae0b0 RK |
2729 | |
2730 | when others => | |
2731 | raise Program_Error; | |
2732 | end case; | |
2733 | ||
93c3fca7 | 2734 | Fold_Uint (N, Test (Result), True); |
996ae0b0 RK |
2735 | end; |
2736 | ||
93c3fca7 | 2737 | -- For all other cases, we use Compile_Time_Compare to do the compare |
996ae0b0 RK |
2738 | |
2739 | else | |
996ae0b0 | 2740 | declare |
93c3fca7 AC |
2741 | CR : constant Compare_Result := |
2742 | Compile_Time_Compare (Left, Right, Assume_Valid => False); | |
996ae0b0 RK |
2743 | |
2744 | begin | |
93c3fca7 AC |
2745 | if CR = Unknown then |
2746 | return; | |
2747 | end if; | |
2748 | ||
996ae0b0 | 2749 | case Nkind (N) is |
93c3fca7 AC |
2750 | when N_Op_Eq => |
2751 | if CR = EQ then | |
2752 | Result := True; | |
2753 | elsif CR = NE or else CR = GT or else CR = LT then | |
2754 | Result := False; | |
2755 | else | |
2756 | return; | |
2757 | end if; | |
2758 | ||
2759 | when N_Op_Ne => | |
2760 | if CR = NE or else CR = GT or else CR = LT then | |
2761 | Result := True; | |
2762 | elsif CR = EQ then | |
2763 | Result := False; | |
2764 | else | |
2765 | return; | |
2766 | end if; | |
2767 | ||
2768 | when N_Op_Lt => | |
2769 | if CR = LT then | |
2770 | Result := True; | |
2771 | elsif CR = EQ or else CR = GT or else CR = GE then | |
2772 | Result := False; | |
2773 | else | |
2774 | return; | |
2775 | end if; | |
2776 | ||
2777 | when N_Op_Le => | |
2778 | if CR = LT or else CR = EQ or else CR = LE then | |
2779 | Result := True; | |
2780 | elsif CR = GT then | |
2781 | Result := False; | |
2782 | else | |
2783 | return; | |
2784 | end if; | |
2785 | ||
2786 | when N_Op_Gt => | |
2787 | if CR = GT then | |
2788 | Result := True; | |
2789 | elsif CR = EQ or else CR = LT or else CR = LE then | |
2790 | Result := False; | |
2791 | else | |
2792 | return; | |
2793 | end if; | |
2794 | ||
2795 | when N_Op_Ge => | |
2796 | if CR = GT or else CR = EQ or else CR = GE then | |
2797 | Result := True; | |
2798 | elsif CR = LT then | |
2799 | Result := False; | |
2800 | else | |
2801 | return; | |
2802 | end if; | |
996ae0b0 RK |
2803 | |
2804 | when others => | |
2805 | raise Program_Error; | |
2806 | end case; | |
996ae0b0 | 2807 | end; |
93c3fca7 AC |
2808 | |
2809 | Fold_Uint (N, Test (Result), Stat); | |
996ae0b0 RK |
2810 | end if; |
2811 | ||
996ae0b0 RK |
2812 | Warn_On_Known_Condition (N); |
2813 | end Eval_Relational_Op; | |
2814 | ||
2815 | ---------------- | |
2816 | -- Eval_Shift -- | |
2817 | ---------------- | |
2818 | ||
2819 | -- Shift operations are intrinsic operations that can never be static, | |
2820 | -- so the only processing required is to perform the required check for | |
2821 | -- a non static context for the two operands. | |
2822 | ||
2823 | -- Actually we could do some compile time evaluation here some time ??? | |
2824 | ||
2825 | procedure Eval_Shift (N : Node_Id) is | |
2826 | begin | |
2827 | Check_Non_Static_Context (Left_Opnd (N)); | |
2828 | Check_Non_Static_Context (Right_Opnd (N)); | |
2829 | end Eval_Shift; | |
2830 | ||
2831 | ------------------------ | |
2832 | -- Eval_Short_Circuit -- | |
2833 | ------------------------ | |
2834 | ||
2835 | -- A short circuit operation is potentially static if both operands | |
2836 | -- are potentially static (RM 4.9 (13)) | |
2837 | ||
2838 | procedure Eval_Short_Circuit (N : Node_Id) is | |
2839 | Kind : constant Node_Kind := Nkind (N); | |
2840 | Left : constant Node_Id := Left_Opnd (N); | |
2841 | Right : constant Node_Id := Right_Opnd (N); | |
2842 | Left_Int : Uint; | |
2843 | Rstat : constant Boolean := | |
2844 | Is_Static_Expression (Left) | |
2845 | and then Is_Static_Expression (Right); | |
2846 | ||
2847 | begin | |
2848 | -- Short circuit operations are never static in Ada 83 | |
2849 | ||
0ab80019 | 2850 | if Ada_Version = Ada_83 |
996ae0b0 RK |
2851 | and then Comes_From_Source (N) |
2852 | then | |
2853 | Check_Non_Static_Context (Left); | |
2854 | Check_Non_Static_Context (Right); | |
2855 | return; | |
2856 | end if; | |
2857 | ||
2858 | -- Now look at the operands, we can't quite use the normal call to | |
2859 | -- Test_Expression_Is_Foldable here because short circuit operations | |
2860 | -- are a special case, they can still be foldable, even if the right | |
2861 | -- operand raises constraint error. | |
2862 | ||
2863 | -- If either operand is Any_Type, just propagate to result and | |
2864 | -- do not try to fold, this prevents cascaded errors. | |
2865 | ||
2866 | if Etype (Left) = Any_Type or else Etype (Right) = Any_Type then | |
2867 | Set_Etype (N, Any_Type); | |
2868 | return; | |
2869 | ||
2870 | -- If left operand raises constraint error, then replace node N with | |
2871 | -- the raise constraint error node, and we are obviously not foldable. | |
2872 | -- Is_Static_Expression is set from the two operands in the normal way, | |
2873 | -- and we check the right operand if it is in a non-static context. | |
2874 | ||
2875 | elsif Raises_Constraint_Error (Left) then | |
2876 | if not Rstat then | |
2877 | Check_Non_Static_Context (Right); | |
2878 | end if; | |
2879 | ||
2880 | Rewrite_In_Raise_CE (N, Left); | |
2881 | Set_Is_Static_Expression (N, Rstat); | |
2882 | return; | |
2883 | ||
2884 | -- If the result is not static, then we won't in any case fold | |
2885 | ||
2886 | elsif not Rstat then | |
2887 | Check_Non_Static_Context (Left); | |
2888 | Check_Non_Static_Context (Right); | |
2889 | return; | |
2890 | end if; | |
2891 | ||
2892 | -- Here the result is static, note that, unlike the normal processing | |
2893 | -- in Test_Expression_Is_Foldable, we did *not* check above to see if | |
2894 | -- the right operand raises constraint error, that's because it is not | |
2895 | -- significant if the left operand is decisive. | |
2896 | ||
2897 | Set_Is_Static_Expression (N); | |
2898 | ||
2899 | -- It does not matter if the right operand raises constraint error if | |
2900 | -- it will not be evaluated. So deal specially with the cases where | |
2901 | -- the right operand is not evaluated. Note that we will fold these | |
2902 | -- cases even if the right operand is non-static, which is fine, but | |
2903 | -- of course in these cases the result is not potentially static. | |
2904 | ||
2905 | Left_Int := Expr_Value (Left); | |
2906 | ||
2907 | if (Kind = N_And_Then and then Is_False (Left_Int)) | |
514d0fc5 AC |
2908 | or else |
2909 | (Kind = N_Or_Else and then Is_True (Left_Int)) | |
996ae0b0 | 2910 | then |
fbf5a39b | 2911 | Fold_Uint (N, Left_Int, Rstat); |
996ae0b0 RK |
2912 | return; |
2913 | end if; | |
2914 | ||
2915 | -- If first operand not decisive, then it does matter if the right | |
2916 | -- operand raises constraint error, since it will be evaluated, so | |
2917 | -- we simply replace the node with the right operand. Note that this | |
2918 | -- properly propagates Is_Static_Expression and Raises_Constraint_Error | |
2919 | -- (both are set to True in Right). | |
2920 | ||
2921 | if Raises_Constraint_Error (Right) then | |
2922 | Rewrite_In_Raise_CE (N, Right); | |
2923 | Check_Non_Static_Context (Left); | |
2924 | return; | |
2925 | end if; | |
2926 | ||
2927 | -- Otherwise the result depends on the right operand | |
2928 | ||
fbf5a39b | 2929 | Fold_Uint (N, Expr_Value (Right), Rstat); |
996ae0b0 | 2930 | return; |
996ae0b0 RK |
2931 | end Eval_Short_Circuit; |
2932 | ||
2933 | ---------------- | |
2934 | -- Eval_Slice -- | |
2935 | ---------------- | |
2936 | ||
2937 | -- Slices can never be static, so the only processing required is to | |
2938 | -- check for non-static context if an explicit range is given. | |
2939 | ||
2940 | procedure Eval_Slice (N : Node_Id) is | |
2941 | Drange : constant Node_Id := Discrete_Range (N); | |
996ae0b0 RK |
2942 | begin |
2943 | if Nkind (Drange) = N_Range then | |
2944 | Check_Non_Static_Context (Low_Bound (Drange)); | |
2945 | Check_Non_Static_Context (High_Bound (Drange)); | |
2946 | end if; | |
cd2fb920 ES |
2947 | |
2948 | -- A slice of the form A (subtype), when the subtype is the index of | |
2949 | -- the type of A, is redundant, the slice can be replaced with A, and | |
2950 | -- this is worth a warning. | |
2951 | ||
2952 | if Is_Entity_Name (Prefix (N)) then | |
2953 | declare | |
2954 | E : constant Entity_Id := Entity (Prefix (N)); | |
2955 | T : constant Entity_Id := Etype (E); | |
2956 | begin | |
2957 | if Ekind (E) = E_Constant | |
2958 | and then Is_Array_Type (T) | |
2959 | and then Is_Entity_Name (Drange) | |
2960 | then | |
2961 | if Is_Entity_Name (Original_Node (First_Index (T))) | |
2962 | and then Entity (Original_Node (First_Index (T))) | |
2963 | = Entity (Drange) | |
2964 | then | |
2965 | if Warn_On_Redundant_Constructs then | |
2966 | Error_Msg_N ("redundant slice denotes whole array?", N); | |
2967 | end if; | |
2968 | ||
2969 | -- The following might be a useful optimization ???? | |
2970 | ||
2971 | -- Rewrite (N, New_Occurrence_Of (E, Sloc (N))); | |
2972 | end if; | |
2973 | end if; | |
2974 | end; | |
2975 | end if; | |
996ae0b0 RK |
2976 | end Eval_Slice; |
2977 | ||
2978 | ------------------------- | |
2979 | -- Eval_String_Literal -- | |
2980 | ------------------------- | |
2981 | ||
2982 | procedure Eval_String_Literal (N : Node_Id) is | |
91b1417d AC |
2983 | Typ : constant Entity_Id := Etype (N); |
2984 | Bas : constant Entity_Id := Base_Type (Typ); | |
2985 | Xtp : Entity_Id; | |
2986 | Len : Nat; | |
2987 | Lo : Node_Id; | |
996ae0b0 RK |
2988 | |
2989 | begin | |
2990 | -- Nothing to do if error type (handles cases like default expressions | |
2991 | -- or generics where we have not yet fully resolved the type) | |
2992 | ||
91b1417d | 2993 | if Bas = Any_Type or else Bas = Any_String then |
996ae0b0 | 2994 | return; |
91b1417d | 2995 | end if; |
996ae0b0 RK |
2996 | |
2997 | -- String literals are static if the subtype is static (RM 4.9(2)), so | |
2998 | -- reset the static expression flag (it was set unconditionally in | |
2999 | -- Analyze_String_Literal) if the subtype is non-static. We tell if | |
3000 | -- the subtype is static by looking at the lower bound. | |
3001 | ||
91b1417d AC |
3002 | if Ekind (Typ) = E_String_Literal_Subtype then |
3003 | if not Is_OK_Static_Expression (String_Literal_Low_Bound (Typ)) then | |
3004 | Set_Is_Static_Expression (N, False); | |
3005 | return; | |
3006 | end if; | |
3007 | ||
3008 | -- Here if Etype of string literal is normal Etype (not yet possible, | |
3009 | -- but may be possible in future!) | |
3010 | ||
3011 | elsif not Is_OK_Static_Expression | |
3012 | (Type_Low_Bound (Etype (First_Index (Typ)))) | |
3013 | then | |
996ae0b0 | 3014 | Set_Is_Static_Expression (N, False); |
91b1417d AC |
3015 | return; |
3016 | end if; | |
996ae0b0 | 3017 | |
91b1417d AC |
3018 | -- If original node was a type conversion, then result if non-static |
3019 | ||
3020 | if Nkind (Original_Node (N)) = N_Type_Conversion then | |
996ae0b0 | 3021 | Set_Is_Static_Expression (N, False); |
91b1417d AC |
3022 | return; |
3023 | end if; | |
996ae0b0 RK |
3024 | |
3025 | -- Test for illegal Ada 95 cases. A string literal is illegal in | |
3026 | -- Ada 95 if its bounds are outside the index base type and this | |
91b1417d | 3027 | -- index type is static. This can happen in only two ways. Either |
996ae0b0 RK |
3028 | -- the string literal is too long, or it is null, and the lower |
3029 | -- bound is type'First. In either case it is the upper bound that | |
3030 | -- is out of range of the index type. | |
3031 | ||
0ab80019 | 3032 | if Ada_Version >= Ada_95 then |
91b1417d AC |
3033 | if Root_Type (Bas) = Standard_String |
3034 | or else | |
3035 | Root_Type (Bas) = Standard_Wide_String | |
996ae0b0 | 3036 | then |
91b1417d | 3037 | Xtp := Standard_Positive; |
996ae0b0 | 3038 | else |
91b1417d | 3039 | Xtp := Etype (First_Index (Bas)); |
996ae0b0 RK |
3040 | end if; |
3041 | ||
91b1417d AC |
3042 | if Ekind (Typ) = E_String_Literal_Subtype then |
3043 | Lo := String_Literal_Low_Bound (Typ); | |
3044 | else | |
3045 | Lo := Type_Low_Bound (Etype (First_Index (Typ))); | |
3046 | end if; | |
3047 | ||
3048 | Len := String_Length (Strval (N)); | |
3049 | ||
3050 | if UI_From_Int (Len) > String_Type_Len (Bas) then | |
996ae0b0 | 3051 | Apply_Compile_Time_Constraint_Error |
07fc65c4 | 3052 | (N, "string literal too long for}", CE_Length_Check_Failed, |
91b1417d AC |
3053 | Ent => Bas, |
3054 | Typ => First_Subtype (Bas)); | |
996ae0b0 | 3055 | |
91b1417d AC |
3056 | elsif Len = 0 |
3057 | and then not Is_Generic_Type (Xtp) | |
3058 | and then | |
3059 | Expr_Value (Lo) = Expr_Value (Type_Low_Bound (Base_Type (Xtp))) | |
996ae0b0 RK |
3060 | then |
3061 | Apply_Compile_Time_Constraint_Error | |
3062 | (N, "null string literal not allowed for}", | |
07fc65c4 | 3063 | CE_Length_Check_Failed, |
91b1417d AC |
3064 | Ent => Bas, |
3065 | Typ => First_Subtype (Bas)); | |
996ae0b0 RK |
3066 | end if; |
3067 | end if; | |
996ae0b0 RK |
3068 | end Eval_String_Literal; |
3069 | ||
3070 | -------------------------- | |
3071 | -- Eval_Type_Conversion -- | |
3072 | -------------------------- | |
3073 | ||
3074 | -- A type conversion is potentially static if its subtype mark is for a | |
3075 | -- static scalar subtype, and its operand expression is potentially static | |
3076 | -- (RM 4.9 (10)) | |
3077 | ||
3078 | procedure Eval_Type_Conversion (N : Node_Id) is | |
3079 | Operand : constant Node_Id := Expression (N); | |
3080 | Source_Type : constant Entity_Id := Etype (Operand); | |
3081 | Target_Type : constant Entity_Id := Etype (N); | |
3082 | ||
3083 | Stat : Boolean; | |
3084 | Fold : Boolean; | |
3085 | ||
3086 | function To_Be_Treated_As_Integer (T : Entity_Id) return Boolean; | |
3087 | -- Returns true if type T is an integer type, or if it is a | |
3088 | -- fixed-point type to be treated as an integer (i.e. the flag | |
3089 | -- Conversion_OK is set on the conversion node). | |
3090 | ||
3091 | function To_Be_Treated_As_Real (T : Entity_Id) return Boolean; | |
3092 | -- Returns true if type T is a floating-point type, or if it is a | |
3093 | -- fixed-point type that is not to be treated as an integer (i.e. the | |
3094 | -- flag Conversion_OK is not set on the conversion node). | |
3095 | ||
fbf5a39b AC |
3096 | ------------------------------ |
3097 | -- To_Be_Treated_As_Integer -- | |
3098 | ------------------------------ | |
3099 | ||
996ae0b0 RK |
3100 | function To_Be_Treated_As_Integer (T : Entity_Id) return Boolean is |
3101 | begin | |
3102 | return | |
3103 | Is_Integer_Type (T) | |
3104 | or else (Is_Fixed_Point_Type (T) and then Conversion_OK (N)); | |
3105 | end To_Be_Treated_As_Integer; | |
3106 | ||
fbf5a39b AC |
3107 | --------------------------- |
3108 | -- To_Be_Treated_As_Real -- | |
3109 | --------------------------- | |
3110 | ||
996ae0b0 RK |
3111 | function To_Be_Treated_As_Real (T : Entity_Id) return Boolean is |
3112 | begin | |
3113 | return | |
3114 | Is_Floating_Point_Type (T) | |
3115 | or else (Is_Fixed_Point_Type (T) and then not Conversion_OK (N)); | |
3116 | end To_Be_Treated_As_Real; | |
3117 | ||
3118 | -- Start of processing for Eval_Type_Conversion | |
3119 | ||
3120 | begin | |
82c80734 | 3121 | -- Cannot fold if target type is non-static or if semantic error |
996ae0b0 RK |
3122 | |
3123 | if not Is_Static_Subtype (Target_Type) then | |
3124 | Check_Non_Static_Context (Operand); | |
3125 | return; | |
3126 | ||
3127 | elsif Error_Posted (N) then | |
3128 | return; | |
3129 | end if; | |
3130 | ||
3131 | -- If not foldable we are done | |
3132 | ||
3133 | Test_Expression_Is_Foldable (N, Operand, Stat, Fold); | |
3134 | ||
3135 | if not Fold then | |
3136 | return; | |
3137 | ||
3138 | -- Don't try fold if target type has constraint error bounds | |
3139 | ||
3140 | elsif not Is_OK_Static_Subtype (Target_Type) then | |
3141 | Set_Raises_Constraint_Error (N); | |
3142 | return; | |
3143 | end if; | |
3144 | ||
3145 | -- Remaining processing depends on operand types. Note that in the | |
3146 | -- following type test, fixed-point counts as real unless the flag | |
3147 | -- Conversion_OK is set, in which case it counts as integer. | |
3148 | ||
82c80734 | 3149 | -- Fold conversion, case of string type. The result is not static |
996ae0b0 RK |
3150 | |
3151 | if Is_String_Type (Target_Type) then | |
b11e8d6f | 3152 | Fold_Str (N, Strval (Get_String_Val (Operand)), Static => False); |
996ae0b0 RK |
3153 | |
3154 | return; | |
3155 | ||
3156 | -- Fold conversion, case of integer target type | |
3157 | ||
3158 | elsif To_Be_Treated_As_Integer (Target_Type) then | |
3159 | declare | |
3160 | Result : Uint; | |
3161 | ||
3162 | begin | |
3163 | -- Integer to integer conversion | |
3164 | ||
3165 | if To_Be_Treated_As_Integer (Source_Type) then | |
3166 | Result := Expr_Value (Operand); | |
3167 | ||
3168 | -- Real to integer conversion | |
3169 | ||
3170 | else | |
3171 | Result := UR_To_Uint (Expr_Value_R (Operand)); | |
3172 | end if; | |
3173 | ||
3174 | -- If fixed-point type (Conversion_OK must be set), then the | |
3175 | -- result is logically an integer, but we must replace the | |
3176 | -- conversion with the corresponding real literal, since the | |
3177 | -- type from a semantic point of view is still fixed-point. | |
3178 | ||
3179 | if Is_Fixed_Point_Type (Target_Type) then | |
3180 | Fold_Ureal | |
fbf5a39b | 3181 | (N, UR_From_Uint (Result) * Small_Value (Target_Type), Stat); |
996ae0b0 RK |
3182 | |
3183 | -- Otherwise result is integer literal | |
3184 | ||
3185 | else | |
fbf5a39b | 3186 | Fold_Uint (N, Result, Stat); |
996ae0b0 RK |
3187 | end if; |
3188 | end; | |
3189 | ||
3190 | -- Fold conversion, case of real target type | |
3191 | ||
3192 | elsif To_Be_Treated_As_Real (Target_Type) then | |
3193 | declare | |
3194 | Result : Ureal; | |
3195 | ||
3196 | begin | |
3197 | if To_Be_Treated_As_Real (Source_Type) then | |
3198 | Result := Expr_Value_R (Operand); | |
3199 | else | |
3200 | Result := UR_From_Uint (Expr_Value (Operand)); | |
3201 | end if; | |
3202 | ||
fbf5a39b | 3203 | Fold_Ureal (N, Result, Stat); |
996ae0b0 RK |
3204 | end; |
3205 | ||
3206 | -- Enumeration types | |
3207 | ||
3208 | else | |
fbf5a39b | 3209 | Fold_Uint (N, Expr_Value (Operand), Stat); |
996ae0b0 RK |
3210 | end if; |
3211 | ||
c800f862 | 3212 | if Is_Out_Of_Range (N, Etype (N), Assume_Valid => True) then |
996ae0b0 RK |
3213 | Out_Of_Range (N); |
3214 | end if; | |
3215 | ||
3216 | end Eval_Type_Conversion; | |
3217 | ||
3218 | ------------------- | |
3219 | -- Eval_Unary_Op -- | |
3220 | ------------------- | |
3221 | ||
3222 | -- Predefined unary operators are static functions (RM 4.9(20)) and thus | |
3223 | -- are potentially static if the operand is potentially static (RM 4.9(7)) | |
3224 | ||
3225 | procedure Eval_Unary_Op (N : Node_Id) is | |
3226 | Right : constant Node_Id := Right_Opnd (N); | |
3227 | Stat : Boolean; | |
3228 | Fold : Boolean; | |
3229 | ||
3230 | begin | |
3231 | -- If not foldable we are done | |
3232 | ||
3233 | Test_Expression_Is_Foldable (N, Right, Stat, Fold); | |
3234 | ||
3235 | if not Fold then | |
3236 | return; | |
3237 | end if; | |
3238 | ||
3239 | -- Fold for integer case | |
3240 | ||
3241 | if Is_Integer_Type (Etype (N)) then | |
3242 | declare | |
3243 | Rint : constant Uint := Expr_Value (Right); | |
3244 | Result : Uint; | |
3245 | ||
3246 | begin | |
3247 | -- In the case of modular unary plus and abs there is no need | |
3248 | -- to adjust the result of the operation since if the original | |
3249 | -- operand was in bounds the result will be in the bounds of the | |
3250 | -- modular type. However, in the case of modular unary minus the | |
3251 | -- result may go out of the bounds of the modular type and needs | |
3252 | -- adjustment. | |
3253 | ||
3254 | if Nkind (N) = N_Op_Plus then | |
3255 | Result := Rint; | |
3256 | ||
3257 | elsif Nkind (N) = N_Op_Minus then | |
3258 | if Is_Modular_Integer_Type (Etype (N)) then | |
3259 | Result := (-Rint) mod Modulus (Etype (N)); | |
3260 | else | |
3261 | Result := (-Rint); | |
3262 | end if; | |
3263 | ||
3264 | else | |
3265 | pragma Assert (Nkind (N) = N_Op_Abs); | |
3266 | Result := abs Rint; | |
3267 | end if; | |
3268 | ||
fbf5a39b | 3269 | Fold_Uint (N, Result, Stat); |
996ae0b0 RK |
3270 | end; |
3271 | ||
3272 | -- Fold for real case | |
3273 | ||
3274 | elsif Is_Real_Type (Etype (N)) then | |
3275 | declare | |
3276 | Rreal : constant Ureal := Expr_Value_R (Right); | |
3277 | Result : Ureal; | |
3278 | ||
3279 | begin | |
3280 | if Nkind (N) = N_Op_Plus then | |
3281 | Result := Rreal; | |
3282 | ||
3283 | elsif Nkind (N) = N_Op_Minus then | |
3284 | Result := UR_Negate (Rreal); | |
3285 | ||
3286 | else | |
3287 | pragma Assert (Nkind (N) = N_Op_Abs); | |
3288 | Result := abs Rreal; | |
3289 | end if; | |
3290 | ||
fbf5a39b | 3291 | Fold_Ureal (N, Result, Stat); |
996ae0b0 RK |
3292 | end; |
3293 | end if; | |
996ae0b0 RK |
3294 | end Eval_Unary_Op; |
3295 | ||
3296 | ------------------------------- | |
3297 | -- Eval_Unchecked_Conversion -- | |
3298 | ------------------------------- | |
3299 | ||
3300 | -- Unchecked conversions can never be static, so the only required | |
3301 | -- processing is to check for a non-static context for the operand. | |
3302 | ||
3303 | procedure Eval_Unchecked_Conversion (N : Node_Id) is | |
3304 | begin | |
3305 | Check_Non_Static_Context (Expression (N)); | |
3306 | end Eval_Unchecked_Conversion; | |
3307 | ||
3308 | -------------------- | |
3309 | -- Expr_Rep_Value -- | |
3310 | -------------------- | |
3311 | ||
3312 | function Expr_Rep_Value (N : Node_Id) return Uint is | |
07fc65c4 GB |
3313 | Kind : constant Node_Kind := Nkind (N); |
3314 | Ent : Entity_Id; | |
996ae0b0 RK |
3315 | |
3316 | begin | |
3317 | if Is_Entity_Name (N) then | |
3318 | Ent := Entity (N); | |
3319 | ||
3320 | -- An enumeration literal that was either in the source or | |
3321 | -- created as a result of static evaluation. | |
3322 | ||
3323 | if Ekind (Ent) = E_Enumeration_Literal then | |
3324 | return Enumeration_Rep (Ent); | |
3325 | ||
3326 | -- A user defined static constant | |
3327 | ||
3328 | else | |
3329 | pragma Assert (Ekind (Ent) = E_Constant); | |
3330 | return Expr_Rep_Value (Constant_Value (Ent)); | |
3331 | end if; | |
3332 | ||
3333 | -- An integer literal that was either in the source or created | |
3334 | -- as a result of static evaluation. | |
3335 | ||
3336 | elsif Kind = N_Integer_Literal then | |
3337 | return Intval (N); | |
3338 | ||
3339 | -- A real literal for a fixed-point type. This must be the fixed-point | |
3340 | -- case, either the literal is of a fixed-point type, or it is a bound | |
3341 | -- of a fixed-point type, with type universal real. In either case we | |
3342 | -- obtain the desired value from Corresponding_Integer_Value. | |
3343 | ||
3344 | elsif Kind = N_Real_Literal then | |
996ae0b0 RK |
3345 | pragma Assert (Is_Fixed_Point_Type (Underlying_Type (Etype (N)))); |
3346 | return Corresponding_Integer_Value (N); | |
3347 | ||
07fc65c4 GB |
3348 | -- Peculiar VMS case, if we have xxx'Null_Parameter, return zero |
3349 | ||
3350 | elsif Kind = N_Attribute_Reference | |
3351 | and then Attribute_Name (N) = Name_Null_Parameter | |
3352 | then | |
3353 | return Uint_0; | |
3354 | ||
07fc65c4 | 3355 | -- Otherwise must be character literal |
8cbb664e | 3356 | |
996ae0b0 RK |
3357 | else |
3358 | pragma Assert (Kind = N_Character_Literal); | |
3359 | Ent := Entity (N); | |
3360 | ||
3361 | -- Since Character literals of type Standard.Character don't | |
3362 | -- have any defining character literals built for them, they | |
3363 | -- do not have their Entity set, so just use their Char | |
3364 | -- code. Otherwise for user-defined character literals use | |
3365 | -- their Pos value as usual which is the same as the Rep value. | |
3366 | ||
3367 | if No (Ent) then | |
82c80734 | 3368 | return Char_Literal_Value (N); |
996ae0b0 RK |
3369 | else |
3370 | return Enumeration_Rep (Ent); | |
3371 | end if; | |
3372 | end if; | |
3373 | end Expr_Rep_Value; | |
3374 | ||
3375 | ---------------- | |
3376 | -- Expr_Value -- | |
3377 | ---------------- | |
3378 | ||
3379 | function Expr_Value (N : Node_Id) return Uint is | |
07fc65c4 GB |
3380 | Kind : constant Node_Kind := Nkind (N); |
3381 | CV_Ent : CV_Entry renames CV_Cache (Nat (N) mod CV_Cache_Size); | |
3382 | Ent : Entity_Id; | |
3383 | Val : Uint; | |
996ae0b0 RK |
3384 | |
3385 | begin | |
13f34a3f RD |
3386 | -- If already in cache, then we know it's compile time known and we can |
3387 | -- return the value that was previously stored in the cache since | |
3388 | -- compile time known values cannot change. | |
07fc65c4 GB |
3389 | |
3390 | if CV_Ent.N = N then | |
3391 | return CV_Ent.V; | |
3392 | end if; | |
3393 | ||
3394 | -- Otherwise proceed to test value | |
3395 | ||
996ae0b0 RK |
3396 | if Is_Entity_Name (N) then |
3397 | Ent := Entity (N); | |
3398 | ||
3399 | -- An enumeration literal that was either in the source or | |
3400 | -- created as a result of static evaluation. | |
3401 | ||
3402 | if Ekind (Ent) = E_Enumeration_Literal then | |
07fc65c4 | 3403 | Val := Enumeration_Pos (Ent); |
996ae0b0 RK |
3404 | |
3405 | -- A user defined static constant | |
3406 | ||
3407 | else | |
3408 | pragma Assert (Ekind (Ent) = E_Constant); | |
07fc65c4 | 3409 | Val := Expr_Value (Constant_Value (Ent)); |
996ae0b0 RK |
3410 | end if; |
3411 | ||
3412 | -- An integer literal that was either in the source or created | |
3413 | -- as a result of static evaluation. | |
3414 | ||
3415 | elsif Kind = N_Integer_Literal then | |
07fc65c4 | 3416 | Val := Intval (N); |
996ae0b0 RK |
3417 | |
3418 | -- A real literal for a fixed-point type. This must be the fixed-point | |
3419 | -- case, either the literal is of a fixed-point type, or it is a bound | |
3420 | -- of a fixed-point type, with type universal real. In either case we | |
3421 | -- obtain the desired value from Corresponding_Integer_Value. | |
3422 | ||
3423 | elsif Kind = N_Real_Literal then | |
3424 | ||
996ae0b0 | 3425 | pragma Assert (Is_Fixed_Point_Type (Underlying_Type (Etype (N)))); |
07fc65c4 | 3426 | Val := Corresponding_Integer_Value (N); |
996ae0b0 RK |
3427 | |
3428 | -- Peculiar VMS case, if we have xxx'Null_Parameter, return zero | |
3429 | ||
3430 | elsif Kind = N_Attribute_Reference | |
3431 | and then Attribute_Name (N) = Name_Null_Parameter | |
3432 | then | |
07fc65c4 GB |
3433 | Val := Uint_0; |
3434 | ||
996ae0b0 RK |
3435 | -- Otherwise must be character literal |
3436 | ||
3437 | else | |
3438 | pragma Assert (Kind = N_Character_Literal); | |
3439 | Ent := Entity (N); | |
3440 | ||
3441 | -- Since Character literals of type Standard.Character don't | |
3442 | -- have any defining character literals built for them, they | |
3443 | -- do not have their Entity set, so just use their Char | |
3444 | -- code. Otherwise for user-defined character literals use | |
3445 | -- their Pos value as usual. | |
3446 | ||
3447 | if No (Ent) then | |
82c80734 | 3448 | Val := Char_Literal_Value (N); |
996ae0b0 | 3449 | else |
07fc65c4 | 3450 | Val := Enumeration_Pos (Ent); |
996ae0b0 RK |
3451 | end if; |
3452 | end if; | |
3453 | ||
07fc65c4 GB |
3454 | -- Come here with Val set to value to be returned, set cache |
3455 | ||
3456 | CV_Ent.N := N; | |
3457 | CV_Ent.V := Val; | |
3458 | return Val; | |
996ae0b0 RK |
3459 | end Expr_Value; |
3460 | ||
3461 | ------------------ | |
3462 | -- Expr_Value_E -- | |
3463 | ------------------ | |
3464 | ||
3465 | function Expr_Value_E (N : Node_Id) return Entity_Id is | |
3466 | Ent : constant Entity_Id := Entity (N); | |
3467 | ||
3468 | begin | |
3469 | if Ekind (Ent) = E_Enumeration_Literal then | |
3470 | return Ent; | |
3471 | else | |
3472 | pragma Assert (Ekind (Ent) = E_Constant); | |
3473 | return Expr_Value_E (Constant_Value (Ent)); | |
3474 | end if; | |
3475 | end Expr_Value_E; | |
3476 | ||
3477 | ------------------ | |
3478 | -- Expr_Value_R -- | |
3479 | ------------------ | |
3480 | ||
3481 | function Expr_Value_R (N : Node_Id) return Ureal is | |
3482 | Kind : constant Node_Kind := Nkind (N); | |
3483 | Ent : Entity_Id; | |
3484 | Expr : Node_Id; | |
3485 | ||
3486 | begin | |
3487 | if Kind = N_Real_Literal then | |
3488 | return Realval (N); | |
3489 | ||
3490 | elsif Kind = N_Identifier or else Kind = N_Expanded_Name then | |
3491 | Ent := Entity (N); | |
3492 | pragma Assert (Ekind (Ent) = E_Constant); | |
3493 | return Expr_Value_R (Constant_Value (Ent)); | |
3494 | ||
3495 | elsif Kind = N_Integer_Literal then | |
3496 | return UR_From_Uint (Expr_Value (N)); | |
3497 | ||
3498 | -- Strange case of VAX literals, which are at this stage transformed | |
3499 | -- into Vax_Type!x_To_y(IEEE_Literal). See Expand_N_Real_Literal in | |
3500 | -- Exp_Vfpt for further details. | |
3501 | ||
3502 | elsif Vax_Float (Etype (N)) | |
3503 | and then Nkind (N) = N_Unchecked_Type_Conversion | |
3504 | then | |
3505 | Expr := Expression (N); | |
3506 | ||
3507 | if Nkind (Expr) = N_Function_Call | |
3508 | and then Present (Parameter_Associations (Expr)) | |
3509 | then | |
3510 | Expr := First (Parameter_Associations (Expr)); | |
3511 | ||
3512 | if Nkind (Expr) = N_Real_Literal then | |
3513 | return Realval (Expr); | |
3514 | end if; | |
3515 | end if; | |
3516 | ||
3517 | -- Peculiar VMS case, if we have xxx'Null_Parameter, return 0.0 | |
3518 | ||
3519 | elsif Kind = N_Attribute_Reference | |
3520 | and then Attribute_Name (N) = Name_Null_Parameter | |
3521 | then | |
3522 | return Ureal_0; | |
3523 | end if; | |
3524 | ||
f3d57416 | 3525 | -- If we fall through, we have a node that cannot be interpreted |
996ae0b0 RK |
3526 | -- as a compile time constant. That is definitely an error. |
3527 | ||
3528 | raise Program_Error; | |
3529 | end Expr_Value_R; | |
3530 | ||
3531 | ------------------ | |
3532 | -- Expr_Value_S -- | |
3533 | ------------------ | |
3534 | ||
3535 | function Expr_Value_S (N : Node_Id) return Node_Id is | |
3536 | begin | |
3537 | if Nkind (N) = N_String_Literal then | |
3538 | return N; | |
3539 | else | |
3540 | pragma Assert (Ekind (Entity (N)) = E_Constant); | |
3541 | return Expr_Value_S (Constant_Value (Entity (N))); | |
3542 | end if; | |
3543 | end Expr_Value_S; | |
3544 | ||
fbf5a39b AC |
3545 | -------------------------- |
3546 | -- Flag_Non_Static_Expr -- | |
3547 | -------------------------- | |
3548 | ||
3549 | procedure Flag_Non_Static_Expr (Msg : String; Expr : Node_Id) is | |
3550 | begin | |
3551 | if Error_Posted (Expr) and then not All_Errors_Mode then | |
3552 | return; | |
3553 | else | |
3554 | Error_Msg_F (Msg, Expr); | |
3555 | Why_Not_Static (Expr); | |
3556 | end if; | |
3557 | end Flag_Non_Static_Expr; | |
3558 | ||
996ae0b0 RK |
3559 | -------------- |
3560 | -- Fold_Str -- | |
3561 | -------------- | |
3562 | ||
fbf5a39b | 3563 | procedure Fold_Str (N : Node_Id; Val : String_Id; Static : Boolean) is |
996ae0b0 RK |
3564 | Loc : constant Source_Ptr := Sloc (N); |
3565 | Typ : constant Entity_Id := Etype (N); | |
3566 | ||
3567 | begin | |
3568 | Rewrite (N, Make_String_Literal (Loc, Strval => Val)); | |
fbf5a39b AC |
3569 | |
3570 | -- We now have the literal with the right value, both the actual type | |
3571 | -- and the expected type of this literal are taken from the expression | |
3572 | -- that was evaluated. | |
3573 | ||
3574 | Analyze (N); | |
3575 | Set_Is_Static_Expression (N, Static); | |
3576 | Set_Etype (N, Typ); | |
3577 | Resolve (N); | |
996ae0b0 RK |
3578 | end Fold_Str; |
3579 | ||
3580 | --------------- | |
3581 | -- Fold_Uint -- | |
3582 | --------------- | |
3583 | ||
fbf5a39b | 3584 | procedure Fold_Uint (N : Node_Id; Val : Uint; Static : Boolean) is |
996ae0b0 | 3585 | Loc : constant Source_Ptr := Sloc (N); |
fbf5a39b AC |
3586 | Typ : Entity_Id := Etype (N); |
3587 | Ent : Entity_Id; | |
996ae0b0 RK |
3588 | |
3589 | begin | |
fbf5a39b AC |
3590 | -- If we are folding a named number, retain the entity in the |
3591 | -- literal, for ASIS use. | |
3592 | ||
3593 | if Is_Entity_Name (N) | |
3594 | and then Ekind (Entity (N)) = E_Named_Integer | |
3595 | then | |
3596 | Ent := Entity (N); | |
3597 | else | |
3598 | Ent := Empty; | |
3599 | end if; | |
3600 | ||
3601 | if Is_Private_Type (Typ) then | |
3602 | Typ := Full_View (Typ); | |
3603 | end if; | |
3604 | ||
f3d57416 | 3605 | -- For a result of type integer, substitute an N_Integer_Literal node |
996ae0b0 | 3606 | -- for the result of the compile time evaluation of the expression. |
cd2fb920 ES |
3607 | -- For ASIS use, set a link to the original named number when not in |
3608 | -- a generic context. | |
996ae0b0 | 3609 | |
fbf5a39b | 3610 | if Is_Integer_Type (Typ) then |
996ae0b0 | 3611 | Rewrite (N, Make_Integer_Literal (Loc, Val)); |
cd2fb920 | 3612 | |
fbf5a39b | 3613 | Set_Original_Entity (N, Ent); |
996ae0b0 RK |
3614 | |
3615 | -- Otherwise we have an enumeration type, and we substitute either | |
3616 | -- an N_Identifier or N_Character_Literal to represent the enumeration | |
3617 | -- literal corresponding to the given value, which must always be in | |
3618 | -- range, because appropriate tests have already been made for this. | |
3619 | ||
fbf5a39b | 3620 | else pragma Assert (Is_Enumeration_Type (Typ)); |
996ae0b0 RK |
3621 | Rewrite (N, Get_Enum_Lit_From_Pos (Etype (N), Val, Loc)); |
3622 | end if; | |
3623 | ||
3624 | -- We now have the literal with the right value, both the actual type | |
3625 | -- and the expected type of this literal are taken from the expression | |
3626 | -- that was evaluated. | |
3627 | ||
3628 | Analyze (N); | |
fbf5a39b | 3629 | Set_Is_Static_Expression (N, Static); |
996ae0b0 | 3630 | Set_Etype (N, Typ); |
fbf5a39b | 3631 | Resolve (N); |
996ae0b0 RK |
3632 | end Fold_Uint; |
3633 | ||
3634 | ---------------- | |
3635 | -- Fold_Ureal -- | |
3636 | ---------------- | |
3637 | ||
fbf5a39b | 3638 | procedure Fold_Ureal (N : Node_Id; Val : Ureal; Static : Boolean) is |
996ae0b0 RK |
3639 | Loc : constant Source_Ptr := Sloc (N); |
3640 | Typ : constant Entity_Id := Etype (N); | |
fbf5a39b | 3641 | Ent : Entity_Id; |
996ae0b0 RK |
3642 | |
3643 | begin | |
fbf5a39b AC |
3644 | -- If we are folding a named number, retain the entity in the |
3645 | -- literal, for ASIS use. | |
3646 | ||
3647 | if Is_Entity_Name (N) | |
3648 | and then Ekind (Entity (N)) = E_Named_Real | |
3649 | then | |
3650 | Ent := Entity (N); | |
3651 | else | |
3652 | Ent := Empty; | |
3653 | end if; | |
3654 | ||
996ae0b0 | 3655 | Rewrite (N, Make_Real_Literal (Loc, Realval => Val)); |
cd2fb920 | 3656 | |
5a30024a | 3657 | -- Set link to original named number, for ASIS use |
cd2fb920 | 3658 | |
fbf5a39b | 3659 | Set_Original_Entity (N, Ent); |
996ae0b0 RK |
3660 | |
3661 | -- Both the actual and expected type comes from the original expression | |
3662 | ||
fbf5a39b AC |
3663 | Analyze (N); |
3664 | Set_Is_Static_Expression (N, Static); | |
996ae0b0 | 3665 | Set_Etype (N, Typ); |
fbf5a39b | 3666 | Resolve (N); |
996ae0b0 RK |
3667 | end Fold_Ureal; |
3668 | ||
3669 | --------------- | |
3670 | -- From_Bits -- | |
3671 | --------------- | |
3672 | ||
3673 | function From_Bits (B : Bits; T : Entity_Id) return Uint is | |
3674 | V : Uint := Uint_0; | |
3675 | ||
3676 | begin | |
3677 | for J in 0 .. B'Last loop | |
3678 | if B (J) then | |
3679 | V := V + 2 ** J; | |
3680 | end if; | |
3681 | end loop; | |
3682 | ||
3683 | if Non_Binary_Modulus (T) then | |
3684 | V := V mod Modulus (T); | |
3685 | end if; | |
3686 | ||
3687 | return V; | |
3688 | end From_Bits; | |
3689 | ||
3690 | -------------------- | |
3691 | -- Get_String_Val -- | |
3692 | -------------------- | |
3693 | ||
3694 | function Get_String_Val (N : Node_Id) return Node_Id is | |
3695 | begin | |
3696 | if Nkind (N) = N_String_Literal then | |
3697 | return N; | |
3698 | ||
3699 | elsif Nkind (N) = N_Character_Literal then | |
3700 | return N; | |
3701 | ||
3702 | else | |
3703 | pragma Assert (Is_Entity_Name (N)); | |
3704 | return Get_String_Val (Constant_Value (Entity (N))); | |
3705 | end if; | |
3706 | end Get_String_Val; | |
3707 | ||
fbf5a39b AC |
3708 | ---------------- |
3709 | -- Initialize -- | |
3710 | ---------------- | |
3711 | ||
3712 | procedure Initialize is | |
3713 | begin | |
3714 | CV_Cache := (others => (Node_High_Bound, Uint_0)); | |
3715 | end Initialize; | |
3716 | ||
996ae0b0 RK |
3717 | -------------------- |
3718 | -- In_Subrange_Of -- | |
3719 | -------------------- | |
3720 | ||
3721 | function In_Subrange_Of | |
c27f2f15 RD |
3722 | (T1 : Entity_Id; |
3723 | T2 : Entity_Id; | |
3724 | Fixed_Int : Boolean := False) return Boolean | |
996ae0b0 RK |
3725 | is |
3726 | L1 : Node_Id; | |
3727 | H1 : Node_Id; | |
3728 | ||
3729 | L2 : Node_Id; | |
3730 | H2 : Node_Id; | |
3731 | ||
3732 | begin | |
3733 | if T1 = T2 or else Is_Subtype_Of (T1, T2) then | |
3734 | return True; | |
3735 | ||
3736 | -- Never in range if both types are not scalar. Don't know if this can | |
3737 | -- actually happen, but just in case. | |
3738 | ||
3739 | elsif not Is_Scalar_Type (T1) or else not Is_Scalar_Type (T1) then | |
3740 | return False; | |
3741 | ||
d79e621a GD |
3742 | -- If T1 has infinities but T2 doesn't have infinities, then T1 is |
3743 | -- definitely not compatible with T2. | |
3744 | ||
3745 | elsif Is_Floating_Point_Type (T1) | |
3746 | and then Has_Infinities (T1) | |
3747 | and then Is_Floating_Point_Type (T2) | |
3748 | and then not Has_Infinities (T2) | |
3749 | then | |
3750 | return False; | |
3751 | ||
996ae0b0 RK |
3752 | else |
3753 | L1 := Type_Low_Bound (T1); | |
3754 | H1 := Type_High_Bound (T1); | |
3755 | ||
3756 | L2 := Type_Low_Bound (T2); | |
3757 | H2 := Type_High_Bound (T2); | |
3758 | ||
3759 | -- Check bounds to see if comparison possible at compile time | |
3760 | ||
c27f2f15 | 3761 | if Compile_Time_Compare (L1, L2, Assume_Valid => True) in Compare_GE |
996ae0b0 | 3762 | and then |
c27f2f15 | 3763 | Compile_Time_Compare (H1, H2, Assume_Valid => True) in Compare_LE |
996ae0b0 RK |
3764 | then |
3765 | return True; | |
3766 | end if; | |
3767 | ||
3768 | -- If bounds not comparable at compile time, then the bounds of T2 | |
3769 | -- must be compile time known or we cannot answer the query. | |
3770 | ||
3771 | if not Compile_Time_Known_Value (L2) | |
3772 | or else not Compile_Time_Known_Value (H2) | |
3773 | then | |
3774 | return False; | |
3775 | end if; | |
3776 | ||
3777 | -- If the bounds of T1 are know at compile time then use these | |
3778 | -- ones, otherwise use the bounds of the base type (which are of | |
3779 | -- course always static). | |
3780 | ||
3781 | if not Compile_Time_Known_Value (L1) then | |
3782 | L1 := Type_Low_Bound (Base_Type (T1)); | |
3783 | end if; | |
3784 | ||
3785 | if not Compile_Time_Known_Value (H1) then | |
3786 | H1 := Type_High_Bound (Base_Type (T1)); | |
3787 | end if; | |
3788 | ||
3789 | -- Fixed point types should be considered as such only if | |
3790 | -- flag Fixed_Int is set to False. | |
3791 | ||
3792 | if Is_Floating_Point_Type (T1) or else Is_Floating_Point_Type (T2) | |
3793 | or else (Is_Fixed_Point_Type (T1) and then not Fixed_Int) | |
3794 | or else (Is_Fixed_Point_Type (T2) and then not Fixed_Int) | |
3795 | then | |
3796 | return | |
3797 | Expr_Value_R (L2) <= Expr_Value_R (L1) | |
3798 | and then | |
3799 | Expr_Value_R (H2) >= Expr_Value_R (H1); | |
3800 | ||
3801 | else | |
3802 | return | |
3803 | Expr_Value (L2) <= Expr_Value (L1) | |
3804 | and then | |
3805 | Expr_Value (H2) >= Expr_Value (H1); | |
3806 | ||
3807 | end if; | |
3808 | end if; | |
3809 | ||
3810 | -- If any exception occurs, it means that we have some bug in the compiler | |
f3d57416 | 3811 | -- possibly triggered by a previous error, or by some unforeseen peculiar |
996ae0b0 RK |
3812 | -- occurrence. However, this is only an optimization attempt, so there is |
3813 | -- really no point in crashing the compiler. Instead we just decide, too | |
3814 | -- bad, we can't figure out the answer in this case after all. | |
3815 | ||
3816 | exception | |
3817 | when others => | |
3818 | ||
3819 | -- Debug flag K disables this behavior (useful for debugging) | |
3820 | ||
3821 | if Debug_Flag_K then | |
3822 | raise; | |
3823 | else | |
3824 | return False; | |
3825 | end if; | |
3826 | end In_Subrange_Of; | |
3827 | ||
3828 | ----------------- | |
3829 | -- Is_In_Range -- | |
3830 | ----------------- | |
3831 | ||
3832 | function Is_In_Range | |
c800f862 RD |
3833 | (N : Node_Id; |
3834 | Typ : Entity_Id; | |
3835 | Assume_Valid : Boolean := False; | |
3836 | Fixed_Int : Boolean := False; | |
3837 | Int_Real : Boolean := False) return Boolean | |
996ae0b0 RK |
3838 | is |
3839 | Val : Uint; | |
3840 | Valr : Ureal; | |
3841 | ||
c27f2f15 RD |
3842 | pragma Warnings (Off, Assume_Valid); |
3843 | -- For now Assume_Valid is unreferenced since the current implementation | |
3844 | -- always returns False if N is not a compile time known value, but we | |
3845 | -- keep the parameter to allow for future enhancements in which we try | |
3846 | -- to get the information in the variable case as well. | |
3847 | ||
996ae0b0 | 3848 | begin |
82c80734 | 3849 | -- Universal types have no range limits, so always in range |
996ae0b0 RK |
3850 | |
3851 | if Typ = Universal_Integer or else Typ = Universal_Real then | |
3852 | return True; | |
3853 | ||
3854 | -- Never in range if not scalar type. Don't know if this can | |
3855 | -- actually happen, but our spec allows it, so we must check! | |
3856 | ||
3857 | elsif not Is_Scalar_Type (Typ) then | |
3858 | return False; | |
3859 | ||
82c80734 | 3860 | -- Never in range unless we have a compile time known value |
996ae0b0 RK |
3861 | |
3862 | elsif not Compile_Time_Known_Value (N) then | |
3863 | return False; | |
3864 | ||
c800f862 RD |
3865 | -- General processing with a known compile time value |
3866 | ||
996ae0b0 RK |
3867 | else |
3868 | declare | |
c800f862 RD |
3869 | Lo : Node_Id; |
3870 | Hi : Node_Id; | |
3871 | LB_Known : Boolean; | |
3872 | UB_Known : Boolean; | |
996ae0b0 RK |
3873 | |
3874 | begin | |
c27f2f15 RD |
3875 | Lo := Type_Low_Bound (Typ); |
3876 | Hi := Type_High_Bound (Typ); | |
c800f862 RD |
3877 | |
3878 | LB_Known := Compile_Time_Known_Value (Lo); | |
3879 | UB_Known := Compile_Time_Known_Value (Hi); | |
3880 | ||
996ae0b0 RK |
3881 | -- Fixed point types should be considered as such only in |
3882 | -- flag Fixed_Int is set to False. | |
3883 | ||
c27f2f15 RD |
3884 | if Is_Floating_Point_Type (Typ) |
3885 | or else (Is_Fixed_Point_Type (Typ) and then not Fixed_Int) | |
996ae0b0 RK |
3886 | or else Int_Real |
3887 | then | |
3888 | Valr := Expr_Value_R (N); | |
3889 | ||
3890 | if LB_Known and then Valr >= Expr_Value_R (Lo) | |
3891 | and then UB_Known and then Valr <= Expr_Value_R (Hi) | |
3892 | then | |
3893 | return True; | |
3894 | else | |
3895 | return False; | |
3896 | end if; | |
3897 | ||
3898 | else | |
3899 | Val := Expr_Value (N); | |
3900 | ||
3901 | if LB_Known and then Val >= Expr_Value (Lo) | |
3902 | and then UB_Known and then Val <= Expr_Value (Hi) | |
3903 | then | |
3904 | return True; | |
3905 | else | |
3906 | return False; | |
3907 | end if; | |
3908 | end if; | |
3909 | end; | |
3910 | end if; | |
3911 | end Is_In_Range; | |
3912 | ||
3913 | ------------------- | |
3914 | -- Is_Null_Range -- | |
3915 | ------------------- | |
3916 | ||
3917 | function Is_Null_Range (Lo : Node_Id; Hi : Node_Id) return Boolean is | |
3918 | Typ : constant Entity_Id := Etype (Lo); | |
3919 | ||
3920 | begin | |
3921 | if not Compile_Time_Known_Value (Lo) | |
3922 | or else not Compile_Time_Known_Value (Hi) | |
3923 | then | |
3924 | return False; | |
3925 | end if; | |
3926 | ||
3927 | if Is_Discrete_Type (Typ) then | |
3928 | return Expr_Value (Lo) > Expr_Value (Hi); | |
3929 | ||
3930 | else | |
3931 | pragma Assert (Is_Real_Type (Typ)); | |
3932 | return Expr_Value_R (Lo) > Expr_Value_R (Hi); | |
3933 | end if; | |
3934 | end Is_Null_Range; | |
3935 | ||
3936 | ----------------------------- | |
3937 | -- Is_OK_Static_Expression -- | |
3938 | ----------------------------- | |
3939 | ||
3940 | function Is_OK_Static_Expression (N : Node_Id) return Boolean is | |
3941 | begin | |
3942 | return Is_Static_Expression (N) | |
3943 | and then not Raises_Constraint_Error (N); | |
3944 | end Is_OK_Static_Expression; | |
3945 | ||
3946 | ------------------------ | |
3947 | -- Is_OK_Static_Range -- | |
3948 | ------------------------ | |
3949 | ||
3950 | -- A static range is a range whose bounds are static expressions, or a | |
3951 | -- Range_Attribute_Reference equivalent to such a range (RM 4.9(26)). | |
3952 | -- We have already converted range attribute references, so we get the | |
3953 | -- "or" part of this rule without needing a special test. | |
3954 | ||
3955 | function Is_OK_Static_Range (N : Node_Id) return Boolean is | |
3956 | begin | |
3957 | return Is_OK_Static_Expression (Low_Bound (N)) | |
3958 | and then Is_OK_Static_Expression (High_Bound (N)); | |
3959 | end Is_OK_Static_Range; | |
3960 | ||
3961 | -------------------------- | |
3962 | -- Is_OK_Static_Subtype -- | |
3963 | -------------------------- | |
3964 | ||
3965 | -- Determines if Typ is a static subtype as defined in (RM 4.9(26)) | |
3966 | -- where neither bound raises constraint error when evaluated. | |
3967 | ||
3968 | function Is_OK_Static_Subtype (Typ : Entity_Id) return Boolean is | |
3969 | Base_T : constant Entity_Id := Base_Type (Typ); | |
3970 | Anc_Subt : Entity_Id; | |
3971 | ||
3972 | begin | |
3973 | -- First a quick check on the non static subtype flag. As described | |
3974 | -- in further detail in Einfo, this flag is not decisive in all cases, | |
3975 | -- but if it is set, then the subtype is definitely non-static. | |
3976 | ||
3977 | if Is_Non_Static_Subtype (Typ) then | |
3978 | return False; | |
3979 | end if; | |
3980 | ||
3981 | Anc_Subt := Ancestor_Subtype (Typ); | |
3982 | ||
3983 | if Anc_Subt = Empty then | |
3984 | Anc_Subt := Base_T; | |
3985 | end if; | |
3986 | ||
3987 | if Is_Generic_Type (Root_Type (Base_T)) | |
3988 | or else Is_Generic_Actual_Type (Base_T) | |
3989 | then | |
3990 | return False; | |
3991 | ||
3992 | -- String types | |
3993 | ||
3994 | elsif Is_String_Type (Typ) then | |
3995 | return | |
3996 | Ekind (Typ) = E_String_Literal_Subtype | |
3997 | or else | |
3998 | (Is_OK_Static_Subtype (Component_Type (Typ)) | |
3999 | and then Is_OK_Static_Subtype (Etype (First_Index (Typ)))); | |
4000 | ||
4001 | -- Scalar types | |
4002 | ||
4003 | elsif Is_Scalar_Type (Typ) then | |
4004 | if Base_T = Typ then | |
4005 | return True; | |
4006 | ||
4007 | else | |
4008 | -- Scalar_Range (Typ) might be an N_Subtype_Indication, so | |
4009 | -- use Get_Type_Low,High_Bound. | |
4010 | ||
4011 | return Is_OK_Static_Subtype (Anc_Subt) | |
4012 | and then Is_OK_Static_Expression (Type_Low_Bound (Typ)) | |
4013 | and then Is_OK_Static_Expression (Type_High_Bound (Typ)); | |
4014 | end if; | |
4015 | ||
4016 | -- Types other than string and scalar types are never static | |
4017 | ||
4018 | else | |
4019 | return False; | |
4020 | end if; | |
4021 | end Is_OK_Static_Subtype; | |
4022 | ||
4023 | --------------------- | |
4024 | -- Is_Out_Of_Range -- | |
4025 | --------------------- | |
4026 | ||
4027 | function Is_Out_Of_Range | |
1c7717c3 AC |
4028 | (N : Node_Id; |
4029 | Typ : Entity_Id; | |
c800f862 | 4030 | Assume_Valid : Boolean := False; |
1c7717c3 AC |
4031 | Fixed_Int : Boolean := False; |
4032 | Int_Real : Boolean := False) return Boolean | |
996ae0b0 RK |
4033 | is |
4034 | Val : Uint; | |
4035 | Valr : Ureal; | |
4036 | ||
c27f2f15 RD |
4037 | pragma Warnings (Off, Assume_Valid); |
4038 | -- For now Assume_Valid is unreferenced since the current implementation | |
4039 | -- always returns False if N is not a compile time known value, but we | |
4040 | -- keep the parameter to allow for future enhancements in which we try | |
4041 | -- to get the information in the variable case as well. | |
4042 | ||
996ae0b0 | 4043 | begin |
82c80734 | 4044 | -- Universal types have no range limits, so always in range |
996ae0b0 RK |
4045 | |
4046 | if Typ = Universal_Integer or else Typ = Universal_Real then | |
4047 | return False; | |
4048 | ||
4049 | -- Never out of range if not scalar type. Don't know if this can | |
4050 | -- actually happen, but our spec allows it, so we must check! | |
4051 | ||
4052 | elsif not Is_Scalar_Type (Typ) then | |
4053 | return False; | |
4054 | ||
4055 | -- Never out of range if this is a generic type, since the bounds | |
4056 | -- of generic types are junk. Note that if we only checked for | |
4057 | -- static expressions (instead of compile time known values) below, | |
4058 | -- we would not need this check, because values of a generic type | |
4059 | -- can never be static, but they can be known at compile time. | |
4060 | ||
4061 | elsif Is_Generic_Type (Typ) then | |
4062 | return False; | |
4063 | ||
fbf5a39b | 4064 | -- Never out of range unless we have a compile time known value |
996ae0b0 RK |
4065 | |
4066 | elsif not Compile_Time_Known_Value (N) then | |
4067 | return False; | |
4068 | ||
4069 | else | |
4070 | declare | |
c800f862 RD |
4071 | Lo : Node_Id; |
4072 | Hi : Node_Id; | |
4073 | LB_Known : Boolean; | |
4074 | UB_Known : Boolean; | |
996ae0b0 RK |
4075 | |
4076 | begin | |
c27f2f15 RD |
4077 | Lo := Type_Low_Bound (Typ); |
4078 | Hi := Type_High_Bound (Typ); | |
c800f862 RD |
4079 | |
4080 | LB_Known := Compile_Time_Known_Value (Lo); | |
4081 | UB_Known := Compile_Time_Known_Value (Hi); | |
4082 | ||
996ae0b0 RK |
4083 | -- Real types (note that fixed-point types are not treated |
4084 | -- as being of a real type if the flag Fixed_Int is set, | |
4085 | -- since in that case they are regarded as integer types). | |
4086 | ||
c27f2f15 RD |
4087 | if Is_Floating_Point_Type (Typ) |
4088 | or else (Is_Fixed_Point_Type (Typ) and then not Fixed_Int) | |
996ae0b0 RK |
4089 | or else Int_Real |
4090 | then | |
4091 | Valr := Expr_Value_R (N); | |
4092 | ||
4093 | if LB_Known and then Valr < Expr_Value_R (Lo) then | |
4094 | return True; | |
4095 | ||
4096 | elsif UB_Known and then Expr_Value_R (Hi) < Valr then | |
4097 | return True; | |
4098 | ||
4099 | else | |
4100 | return False; | |
4101 | end if; | |
4102 | ||
4103 | else | |
4104 | Val := Expr_Value (N); | |
4105 | ||
4106 | if LB_Known and then Val < Expr_Value (Lo) then | |
4107 | return True; | |
4108 | ||
4109 | elsif UB_Known and then Expr_Value (Hi) < Val then | |
4110 | return True; | |
4111 | ||
4112 | else | |
4113 | return False; | |
4114 | end if; | |
4115 | end if; | |
4116 | end; | |
4117 | end if; | |
4118 | end Is_Out_Of_Range; | |
4119 | ||
4120 | --------------------- | |
4121 | -- Is_Static_Range -- | |
4122 | --------------------- | |
4123 | ||
4124 | -- A static range is a range whose bounds are static expressions, or a | |
4125 | -- Range_Attribute_Reference equivalent to such a range (RM 4.9(26)). | |
4126 | -- We have already converted range attribute references, so we get the | |
4127 | -- "or" part of this rule without needing a special test. | |
4128 | ||
4129 | function Is_Static_Range (N : Node_Id) return Boolean is | |
4130 | begin | |
4131 | return Is_Static_Expression (Low_Bound (N)) | |
4132 | and then Is_Static_Expression (High_Bound (N)); | |
4133 | end Is_Static_Range; | |
4134 | ||
4135 | ----------------------- | |
4136 | -- Is_Static_Subtype -- | |
4137 | ----------------------- | |
4138 | ||
82c80734 | 4139 | -- Determines if Typ is a static subtype as defined in (RM 4.9(26)) |
996ae0b0 RK |
4140 | |
4141 | function Is_Static_Subtype (Typ : Entity_Id) return Boolean is | |
4142 | Base_T : constant Entity_Id := Base_Type (Typ); | |
4143 | Anc_Subt : Entity_Id; | |
4144 | ||
4145 | begin | |
4146 | -- First a quick check on the non static subtype flag. As described | |
4147 | -- in further detail in Einfo, this flag is not decisive in all cases, | |
4148 | -- but if it is set, then the subtype is definitely non-static. | |
4149 | ||
4150 | if Is_Non_Static_Subtype (Typ) then | |
4151 | return False; | |
4152 | end if; | |
4153 | ||
4154 | Anc_Subt := Ancestor_Subtype (Typ); | |
4155 | ||
4156 | if Anc_Subt = Empty then | |
4157 | Anc_Subt := Base_T; | |
4158 | end if; | |
4159 | ||
4160 | if Is_Generic_Type (Root_Type (Base_T)) | |
4161 | or else Is_Generic_Actual_Type (Base_T) | |
4162 | then | |
4163 | return False; | |
4164 | ||
4165 | -- String types | |
4166 | ||
4167 | elsif Is_String_Type (Typ) then | |
4168 | return | |
4169 | Ekind (Typ) = E_String_Literal_Subtype | |
4170 | or else | |
4171 | (Is_Static_Subtype (Component_Type (Typ)) | |
4172 | and then Is_Static_Subtype (Etype (First_Index (Typ)))); | |
4173 | ||
4174 | -- Scalar types | |
4175 | ||
4176 | elsif Is_Scalar_Type (Typ) then | |
4177 | if Base_T = Typ then | |
4178 | return True; | |
4179 | ||
4180 | else | |
4181 | return Is_Static_Subtype (Anc_Subt) | |
4182 | and then Is_Static_Expression (Type_Low_Bound (Typ)) | |
4183 | and then Is_Static_Expression (Type_High_Bound (Typ)); | |
4184 | end if; | |
4185 | ||
4186 | -- Types other than string and scalar types are never static | |
4187 | ||
4188 | else | |
4189 | return False; | |
4190 | end if; | |
4191 | end Is_Static_Subtype; | |
4192 | ||
4193 | -------------------- | |
4194 | -- Not_Null_Range -- | |
4195 | -------------------- | |
4196 | ||
4197 | function Not_Null_Range (Lo : Node_Id; Hi : Node_Id) return Boolean is | |
4198 | Typ : constant Entity_Id := Etype (Lo); | |
4199 | ||
4200 | begin | |
4201 | if not Compile_Time_Known_Value (Lo) | |
4202 | or else not Compile_Time_Known_Value (Hi) | |
4203 | then | |
4204 | return False; | |
4205 | end if; | |
4206 | ||
4207 | if Is_Discrete_Type (Typ) then | |
4208 | return Expr_Value (Lo) <= Expr_Value (Hi); | |
4209 | ||
4210 | else | |
4211 | pragma Assert (Is_Real_Type (Typ)); | |
4212 | ||
4213 | return Expr_Value_R (Lo) <= Expr_Value_R (Hi); | |
4214 | end if; | |
4215 | end Not_Null_Range; | |
4216 | ||
4217 | ------------- | |
4218 | -- OK_Bits -- | |
4219 | ------------- | |
4220 | ||
4221 | function OK_Bits (N : Node_Id; Bits : Uint) return Boolean is | |
4222 | begin | |
4223 | -- We allow a maximum of 500,000 bits which seems a reasonable limit | |
4224 | ||
4225 | if Bits < 500_000 then | |
4226 | return True; | |
4227 | ||
4228 | else | |
4229 | Error_Msg_N ("static value too large, capacity exceeded", N); | |
4230 | return False; | |
4231 | end if; | |
4232 | end OK_Bits; | |
4233 | ||
4234 | ------------------ | |
4235 | -- Out_Of_Range -- | |
4236 | ------------------ | |
4237 | ||
4238 | procedure Out_Of_Range (N : Node_Id) is | |
4239 | begin | |
4240 | -- If we have the static expression case, then this is an illegality | |
4241 | -- in Ada 95 mode, except that in an instance, we never generate an | |
4242 | -- error (if the error is legitimate, it was already diagnosed in | |
4243 | -- the template). The expression to compute the length of a packed | |
4244 | -- array is attached to the array type itself, and deserves a separate | |
4245 | -- message. | |
4246 | ||
4247 | if Is_Static_Expression (N) | |
4248 | and then not In_Instance | |
fbf5a39b | 4249 | and then not In_Inlined_Body |
0ab80019 | 4250 | and then Ada_Version >= Ada_95 |
996ae0b0 | 4251 | then |
996ae0b0 RK |
4252 | if Nkind (Parent (N)) = N_Defining_Identifier |
4253 | and then Is_Array_Type (Parent (N)) | |
4254 | and then Present (Packed_Array_Type (Parent (N))) | |
4255 | and then Present (First_Rep_Item (Parent (N))) | |
4256 | then | |
4257 | Error_Msg_N | |
4258 | ("length of packed array must not exceed Integer''Last", | |
4259 | First_Rep_Item (Parent (N))); | |
4260 | Rewrite (N, Make_Integer_Literal (Sloc (N), Uint_1)); | |
4261 | ||
4262 | else | |
4263 | Apply_Compile_Time_Constraint_Error | |
07fc65c4 | 4264 | (N, "value not in range of}", CE_Range_Check_Failed); |
996ae0b0 RK |
4265 | end if; |
4266 | ||
4267 | -- Here we generate a warning for the Ada 83 case, or when we are | |
4268 | -- in an instance, or when we have a non-static expression case. | |
4269 | ||
4270 | else | |
996ae0b0 | 4271 | Apply_Compile_Time_Constraint_Error |
07fc65c4 | 4272 | (N, "value not in range of}?", CE_Range_Check_Failed); |
996ae0b0 RK |
4273 | end if; |
4274 | end Out_Of_Range; | |
4275 | ||
4276 | ------------------------- | |
4277 | -- Rewrite_In_Raise_CE -- | |
4278 | ------------------------- | |
4279 | ||
4280 | procedure Rewrite_In_Raise_CE (N : Node_Id; Exp : Node_Id) is | |
4281 | Typ : constant Entity_Id := Etype (N); | |
4282 | ||
4283 | begin | |
4284 | -- If we want to raise CE in the condition of a raise_CE node | |
4285 | -- we may as well get rid of the condition | |
4286 | ||
4287 | if Present (Parent (N)) | |
4288 | and then Nkind (Parent (N)) = N_Raise_Constraint_Error | |
4289 | then | |
4290 | Set_Condition (Parent (N), Empty); | |
4291 | ||
4292 | -- If the expression raising CE is a N_Raise_CE node, we can use | |
4293 | -- that one. We just preserve the type of the context | |
4294 | ||
4295 | elsif Nkind (Exp) = N_Raise_Constraint_Error then | |
4296 | Rewrite (N, Exp); | |
4297 | Set_Etype (N, Typ); | |
4298 | ||
4299 | -- We have to build an explicit raise_ce node | |
4300 | ||
4301 | else | |
07fc65c4 GB |
4302 | Rewrite (N, |
4303 | Make_Raise_Constraint_Error (Sloc (Exp), | |
4304 | Reason => CE_Range_Check_Failed)); | |
996ae0b0 RK |
4305 | Set_Raises_Constraint_Error (N); |
4306 | Set_Etype (N, Typ); | |
4307 | end if; | |
4308 | end Rewrite_In_Raise_CE; | |
4309 | ||
4310 | --------------------- | |
4311 | -- String_Type_Len -- | |
4312 | --------------------- | |
4313 | ||
4314 | function String_Type_Len (Stype : Entity_Id) return Uint is | |
4315 | NT : constant Entity_Id := Etype (First_Index (Stype)); | |
4316 | T : Entity_Id; | |
4317 | ||
4318 | begin | |
4319 | if Is_OK_Static_Subtype (NT) then | |
4320 | T := NT; | |
4321 | else | |
4322 | T := Base_Type (NT); | |
4323 | end if; | |
4324 | ||
4325 | return Expr_Value (Type_High_Bound (T)) - | |
4326 | Expr_Value (Type_Low_Bound (T)) + 1; | |
4327 | end String_Type_Len; | |
4328 | ||
4329 | ------------------------------------ | |
4330 | -- Subtypes_Statically_Compatible -- | |
4331 | ------------------------------------ | |
4332 | ||
4333 | function Subtypes_Statically_Compatible | |
f44fe430 RD |
4334 | (T1 : Entity_Id; |
4335 | T2 : Entity_Id) return Boolean | |
996ae0b0 RK |
4336 | is |
4337 | begin | |
4338 | if Is_Scalar_Type (T1) then | |
4339 | ||
4340 | -- Definitely compatible if we match | |
4341 | ||
4342 | if Subtypes_Statically_Match (T1, T2) then | |
4343 | return True; | |
4344 | ||
4345 | -- If either subtype is nonstatic then they're not compatible | |
4346 | ||
4347 | elsif not Is_Static_Subtype (T1) | |
4348 | or else not Is_Static_Subtype (T2) | |
4349 | then | |
4350 | return False; | |
4351 | ||
4352 | -- If either type has constraint error bounds, then consider that | |
4353 | -- they match to avoid junk cascaded errors here. | |
4354 | ||
4355 | elsif not Is_OK_Static_Subtype (T1) | |
4356 | or else not Is_OK_Static_Subtype (T2) | |
4357 | then | |
4358 | return True; | |
4359 | ||
4360 | -- Base types must match, but we don't check that (should | |
4361 | -- we???) but we do at least check that both types are | |
4362 | -- real, or both types are not real. | |
4363 | ||
fbf5a39b | 4364 | elsif Is_Real_Type (T1) /= Is_Real_Type (T2) then |
996ae0b0 RK |
4365 | return False; |
4366 | ||
4367 | -- Here we check the bounds | |
4368 | ||
4369 | else | |
4370 | declare | |
4371 | LB1 : constant Node_Id := Type_Low_Bound (T1); | |
4372 | HB1 : constant Node_Id := Type_High_Bound (T1); | |
4373 | LB2 : constant Node_Id := Type_Low_Bound (T2); | |
4374 | HB2 : constant Node_Id := Type_High_Bound (T2); | |
4375 | ||
4376 | begin | |
4377 | if Is_Real_Type (T1) then | |
4378 | return | |
4379 | (Expr_Value_R (LB1) > Expr_Value_R (HB1)) | |
4380 | or else | |
4381 | (Expr_Value_R (LB2) <= Expr_Value_R (LB1) | |
4382 | and then | |
4383 | Expr_Value_R (HB1) <= Expr_Value_R (HB2)); | |
4384 | ||
4385 | else | |
4386 | return | |
4387 | (Expr_Value (LB1) > Expr_Value (HB1)) | |
4388 | or else | |
4389 | (Expr_Value (LB2) <= Expr_Value (LB1) | |
4390 | and then | |
4391 | Expr_Value (HB1) <= Expr_Value (HB2)); | |
4392 | end if; | |
4393 | end; | |
4394 | end if; | |
4395 | ||
4396 | elsif Is_Access_Type (T1) then | |
4397 | return not Is_Constrained (T2) | |
4398 | or else Subtypes_Statically_Match | |
4399 | (Designated_Type (T1), Designated_Type (T2)); | |
4400 | ||
4401 | else | |
4402 | return (Is_Composite_Type (T1) and then not Is_Constrained (T2)) | |
4403 | or else Subtypes_Statically_Match (T1, T2); | |
4404 | end if; | |
4405 | end Subtypes_Statically_Compatible; | |
4406 | ||
4407 | ------------------------------- | |
4408 | -- Subtypes_Statically_Match -- | |
4409 | ------------------------------- | |
4410 | ||
4411 | -- Subtypes statically match if they have statically matching constraints | |
4412 | -- (RM 4.9.1(2)). Constraints statically match if there are none, or if | |
4413 | -- they are the same identical constraint, or if they are static and the | |
4414 | -- values match (RM 4.9.1(1)). | |
4415 | ||
4416 | function Subtypes_Statically_Match (T1, T2 : Entity_Id) return Boolean is | |
4417 | begin | |
4418 | -- A type always statically matches itself | |
4419 | ||
4420 | if T1 = T2 then | |
4421 | return True; | |
4422 | ||
4423 | -- Scalar types | |
4424 | ||
4425 | elsif Is_Scalar_Type (T1) then | |
4426 | ||
4427 | -- Base types must be the same | |
4428 | ||
4429 | if Base_Type (T1) /= Base_Type (T2) then | |
4430 | return False; | |
4431 | end if; | |
4432 | ||
4433 | -- A constrained numeric subtype never matches an unconstrained | |
4434 | -- subtype, i.e. both types must be constrained or unconstrained. | |
4435 | ||
4436 | -- To understand the requirement for this test, see RM 4.9.1(1). | |
4437 | -- As is made clear in RM 3.5.4(11), type Integer, for example | |
4438 | -- is a constrained subtype with constraint bounds matching the | |
f3d57416 | 4439 | -- bounds of its corresponding unconstrained base type. In this |
996ae0b0 RK |
4440 | -- situation, Integer and Integer'Base do not statically match, |
4441 | -- even though they have the same bounds. | |
4442 | ||
4443 | -- We only apply this test to types in Standard and types that | |
4444 | -- appear in user programs. That way, we do not have to be | |
4445 | -- too careful about setting Is_Constrained right for itypes. | |
4446 | ||
4447 | if Is_Numeric_Type (T1) | |
4448 | and then (Is_Constrained (T1) /= Is_Constrained (T2)) | |
4449 | and then (Scope (T1) = Standard_Standard | |
4450 | or else Comes_From_Source (T1)) | |
4451 | and then (Scope (T2) = Standard_Standard | |
4452 | or else Comes_From_Source (T2)) | |
4453 | then | |
4454 | return False; | |
82c80734 RD |
4455 | |
4456 | -- A generic scalar type does not statically match its base | |
4457 | -- type (AI-311). In this case we make sure that the formals, | |
4458 | -- which are first subtypes of their bases, are constrained. | |
4459 | ||
4460 | elsif Is_Generic_Type (T1) | |
4461 | and then Is_Generic_Type (T2) | |
4462 | and then (Is_Constrained (T1) /= Is_Constrained (T2)) | |
4463 | then | |
4464 | return False; | |
996ae0b0 RK |
4465 | end if; |
4466 | ||
4467 | -- If there was an error in either range, then just assume | |
4468 | -- the types statically match to avoid further junk errors | |
4469 | ||
4470 | if Error_Posted (Scalar_Range (T1)) | |
4471 | or else | |
4472 | Error_Posted (Scalar_Range (T2)) | |
4473 | then | |
4474 | return True; | |
4475 | end if; | |
4476 | ||
4477 | -- Otherwise both types have bound that can be compared | |
4478 | ||
4479 | declare | |
4480 | LB1 : constant Node_Id := Type_Low_Bound (T1); | |
4481 | HB1 : constant Node_Id := Type_High_Bound (T1); | |
4482 | LB2 : constant Node_Id := Type_Low_Bound (T2); | |
4483 | HB2 : constant Node_Id := Type_High_Bound (T2); | |
4484 | ||
4485 | begin | |
4486 | -- If the bounds are the same tree node, then match | |
4487 | ||
4488 | if LB1 = LB2 and then HB1 = HB2 then | |
4489 | return True; | |
4490 | ||
4491 | -- Otherwise bounds must be static and identical value | |
4492 | ||
4493 | else | |
4494 | if not Is_Static_Subtype (T1) | |
4495 | or else not Is_Static_Subtype (T2) | |
4496 | then | |
4497 | return False; | |
4498 | ||
4499 | -- If either type has constraint error bounds, then say | |
4500 | -- that they match to avoid junk cascaded errors here. | |
4501 | ||
4502 | elsif not Is_OK_Static_Subtype (T1) | |
4503 | or else not Is_OK_Static_Subtype (T2) | |
4504 | then | |
4505 | return True; | |
4506 | ||
4507 | elsif Is_Real_Type (T1) then | |
4508 | return | |
4509 | (Expr_Value_R (LB1) = Expr_Value_R (LB2)) | |
4510 | and then | |
4511 | (Expr_Value_R (HB1) = Expr_Value_R (HB2)); | |
4512 | ||
4513 | else | |
4514 | return | |
4515 | Expr_Value (LB1) = Expr_Value (LB2) | |
4516 | and then | |
4517 | Expr_Value (HB1) = Expr_Value (HB2); | |
4518 | end if; | |
4519 | end if; | |
4520 | end; | |
4521 | ||
4522 | -- Type with discriminants | |
4523 | ||
4524 | elsif Has_Discriminants (T1) or else Has_Discriminants (T2) then | |
6eaf4095 | 4525 | |
c2bf339e GD |
4526 | -- Because of view exchanges in multiple instantiations, conformance |
4527 | -- checking might try to match a partial view of a type with no | |
4528 | -- discriminants with a full view that has defaulted discriminants. | |
4529 | -- In such a case, use the discriminant constraint of the full view, | |
4530 | -- which must exist because we know that the two subtypes have the | |
4531 | -- same base type. | |
6eaf4095 | 4532 | |
996ae0b0 | 4533 | if Has_Discriminants (T1) /= Has_Discriminants (T2) then |
c2bf339e GD |
4534 | if In_Instance then |
4535 | if Is_Private_Type (T2) | |
4536 | and then Present (Full_View (T2)) | |
4537 | and then Has_Discriminants (Full_View (T2)) | |
4538 | then | |
4539 | return Subtypes_Statically_Match (T1, Full_View (T2)); | |
4540 | ||
4541 | elsif Is_Private_Type (T1) | |
4542 | and then Present (Full_View (T1)) | |
4543 | and then Has_Discriminants (Full_View (T1)) | |
4544 | then | |
4545 | return Subtypes_Statically_Match (Full_View (T1), T2); | |
4546 | ||
4547 | else | |
4548 | return False; | |
4549 | end if; | |
6eaf4095 ES |
4550 | else |
4551 | return False; | |
4552 | end if; | |
996ae0b0 RK |
4553 | end if; |
4554 | ||
4555 | declare | |
4556 | DL1 : constant Elist_Id := Discriminant_Constraint (T1); | |
4557 | DL2 : constant Elist_Id := Discriminant_Constraint (T2); | |
4558 | ||
13f34a3f RD |
4559 | DA1 : Elmt_Id; |
4560 | DA2 : Elmt_Id; | |
996ae0b0 RK |
4561 | |
4562 | begin | |
4563 | if DL1 = DL2 then | |
4564 | return True; | |
996ae0b0 RK |
4565 | elsif Is_Constrained (T1) /= Is_Constrained (T2) then |
4566 | return False; | |
4567 | end if; | |
4568 | ||
13f34a3f | 4569 | -- Now loop through the discriminant constraints |
996ae0b0 | 4570 | |
13f34a3f RD |
4571 | -- Note: the guard here seems necessary, since it is possible at |
4572 | -- least for DL1 to be No_Elist. Not clear this is reasonable ??? | |
996ae0b0 | 4573 | |
13f34a3f RD |
4574 | if Present (DL1) and then Present (DL2) then |
4575 | DA1 := First_Elmt (DL1); | |
4576 | DA2 := First_Elmt (DL2); | |
4577 | while Present (DA1) loop | |
4578 | declare | |
4579 | Expr1 : constant Node_Id := Node (DA1); | |
4580 | Expr2 : constant Node_Id := Node (DA2); | |
996ae0b0 | 4581 | |
13f34a3f RD |
4582 | begin |
4583 | if not Is_Static_Expression (Expr1) | |
4584 | or else not Is_Static_Expression (Expr2) | |
4585 | then | |
4586 | return False; | |
996ae0b0 | 4587 | |
13f34a3f RD |
4588 | -- If either expression raised a constraint error, |
4589 | -- consider the expressions as matching, since this | |
4590 | -- helps to prevent cascading errors. | |
4591 | ||
4592 | elsif Raises_Constraint_Error (Expr1) | |
4593 | or else Raises_Constraint_Error (Expr2) | |
4594 | then | |
4595 | null; | |
4596 | ||
4597 | elsif Expr_Value (Expr1) /= Expr_Value (Expr2) then | |
4598 | return False; | |
4599 | end if; | |
4600 | end; | |
996ae0b0 | 4601 | |
13f34a3f RD |
4602 | Next_Elmt (DA1); |
4603 | Next_Elmt (DA2); | |
4604 | end loop; | |
4605 | end if; | |
996ae0b0 RK |
4606 | end; |
4607 | ||
4608 | return True; | |
4609 | ||
82c80734 | 4610 | -- A definite type does not match an indefinite or classwide type |
0356699b RD |
4611 | -- However, a generic type with unknown discriminants may be |
4612 | -- instantiated with a type with no discriminants, and conformance | |
4613 | -- checking on an inherited operation may compare the actual with | |
4614 | -- the subtype that renames it in the instance. | |
996ae0b0 RK |
4615 | |
4616 | elsif | |
4617 | Has_Unknown_Discriminants (T1) /= Has_Unknown_Discriminants (T2) | |
4618 | then | |
7a3f77d2 AC |
4619 | return |
4620 | Is_Generic_Actual_Type (T1) or else Is_Generic_Actual_Type (T2); | |
996ae0b0 RK |
4621 | |
4622 | -- Array type | |
4623 | ||
4624 | elsif Is_Array_Type (T1) then | |
4625 | ||
4626 | -- If either subtype is unconstrained then both must be, | |
4627 | -- and if both are unconstrained then no further checking | |
4628 | -- is needed. | |
4629 | ||
4630 | if not Is_Constrained (T1) or else not Is_Constrained (T2) then | |
4631 | return not (Is_Constrained (T1) or else Is_Constrained (T2)); | |
4632 | end if; | |
4633 | ||
4634 | -- Both subtypes are constrained, so check that the index | |
4635 | -- subtypes statically match. | |
4636 | ||
4637 | declare | |
4638 | Index1 : Node_Id := First_Index (T1); | |
4639 | Index2 : Node_Id := First_Index (T2); | |
4640 | ||
4641 | begin | |
4642 | while Present (Index1) loop | |
4643 | if not | |
4644 | Subtypes_Statically_Match (Etype (Index1), Etype (Index2)) | |
4645 | then | |
4646 | return False; | |
4647 | end if; | |
4648 | ||
4649 | Next_Index (Index1); | |
4650 | Next_Index (Index2); | |
4651 | end loop; | |
4652 | ||
4653 | return True; | |
4654 | end; | |
4655 | ||
4656 | elsif Is_Access_Type (T1) then | |
b5bd964f ES |
4657 | if Can_Never_Be_Null (T1) /= Can_Never_Be_Null (T2) then |
4658 | return False; | |
4659 | ||
7a3f77d2 AC |
4660 | elsif Ekind (T1) = E_Access_Subprogram_Type |
4661 | or else Ekind (T1) = E_Anonymous_Access_Subprogram_Type | |
4662 | then | |
b5bd964f ES |
4663 | return |
4664 | Subtype_Conformant | |
4665 | (Designated_Type (T1), | |
bb98fe75 | 4666 | Designated_Type (T2)); |
b5bd964f ES |
4667 | else |
4668 | return | |
4669 | Subtypes_Statically_Match | |
4670 | (Designated_Type (T1), | |
4671 | Designated_Type (T2)) | |
4672 | and then Is_Access_Constant (T1) = Is_Access_Constant (T2); | |
4673 | end if; | |
996ae0b0 RK |
4674 | |
4675 | -- All other types definitely match | |
4676 | ||
4677 | else | |
4678 | return True; | |
4679 | end if; | |
4680 | end Subtypes_Statically_Match; | |
4681 | ||
4682 | ---------- | |
4683 | -- Test -- | |
4684 | ---------- | |
4685 | ||
4686 | function Test (Cond : Boolean) return Uint is | |
4687 | begin | |
4688 | if Cond then | |
4689 | return Uint_1; | |
4690 | else | |
4691 | return Uint_0; | |
4692 | end if; | |
4693 | end Test; | |
4694 | ||
4695 | --------------------------------- | |
4696 | -- Test_Expression_Is_Foldable -- | |
4697 | --------------------------------- | |
4698 | ||
4699 | -- One operand case | |
4700 | ||
4701 | procedure Test_Expression_Is_Foldable | |
4702 | (N : Node_Id; | |
4703 | Op1 : Node_Id; | |
4704 | Stat : out Boolean; | |
4705 | Fold : out Boolean) | |
4706 | is | |
4707 | begin | |
4708 | Stat := False; | |
0356699b RD |
4709 | Fold := False; |
4710 | ||
4711 | if Debug_Flag_Dot_F and then In_Extended_Main_Source_Unit (N) then | |
4712 | return; | |
4713 | end if; | |
996ae0b0 RK |
4714 | |
4715 | -- If operand is Any_Type, just propagate to result and do not | |
4716 | -- try to fold, this prevents cascaded errors. | |
4717 | ||
4718 | if Etype (Op1) = Any_Type then | |
4719 | Set_Etype (N, Any_Type); | |
996ae0b0 RK |
4720 | return; |
4721 | ||
4722 | -- If operand raises constraint error, then replace node N with the | |
4723 | -- raise constraint error node, and we are obviously not foldable. | |
4724 | -- Note that this replacement inherits the Is_Static_Expression flag | |
4725 | -- from the operand. | |
4726 | ||
4727 | elsif Raises_Constraint_Error (Op1) then | |
4728 | Rewrite_In_Raise_CE (N, Op1); | |
996ae0b0 RK |
4729 | return; |
4730 | ||
4731 | -- If the operand is not static, then the result is not static, and | |
4732 | -- all we have to do is to check the operand since it is now known | |
4733 | -- to appear in a non-static context. | |
4734 | ||
4735 | elsif not Is_Static_Expression (Op1) then | |
4736 | Check_Non_Static_Context (Op1); | |
4737 | Fold := Compile_Time_Known_Value (Op1); | |
4738 | return; | |
4739 | ||
4740 | -- An expression of a formal modular type is not foldable because | |
4741 | -- the modulus is unknown. | |
4742 | ||
4743 | elsif Is_Modular_Integer_Type (Etype (Op1)) | |
4744 | and then Is_Generic_Type (Etype (Op1)) | |
4745 | then | |
4746 | Check_Non_Static_Context (Op1); | |
996ae0b0 RK |
4747 | return; |
4748 | ||
4749 | -- Here we have the case of an operand whose type is OK, which is | |
4750 | -- static, and which does not raise constraint error, we can fold. | |
4751 | ||
4752 | else | |
4753 | Set_Is_Static_Expression (N); | |
4754 | Fold := True; | |
4755 | Stat := True; | |
4756 | end if; | |
4757 | end Test_Expression_Is_Foldable; | |
4758 | ||
4759 | -- Two operand case | |
4760 | ||
4761 | procedure Test_Expression_Is_Foldable | |
4762 | (N : Node_Id; | |
4763 | Op1 : Node_Id; | |
4764 | Op2 : Node_Id; | |
4765 | Stat : out Boolean; | |
4766 | Fold : out Boolean) | |
4767 | is | |
4768 | Rstat : constant Boolean := Is_Static_Expression (Op1) | |
4769 | and then Is_Static_Expression (Op2); | |
4770 | ||
4771 | begin | |
4772 | Stat := False; | |
0356699b RD |
4773 | Fold := False; |
4774 | ||
4775 | if Debug_Flag_Dot_F and then In_Extended_Main_Source_Unit (N) then | |
4776 | return; | |
4777 | end if; | |
996ae0b0 RK |
4778 | |
4779 | -- If either operand is Any_Type, just propagate to result and | |
4780 | -- do not try to fold, this prevents cascaded errors. | |
4781 | ||
4782 | if Etype (Op1) = Any_Type or else Etype (Op2) = Any_Type then | |
4783 | Set_Etype (N, Any_Type); | |
996ae0b0 RK |
4784 | return; |
4785 | ||
4786 | -- If left operand raises constraint error, then replace node N with | |
4787 | -- the raise constraint error node, and we are obviously not foldable. | |
4788 | -- Is_Static_Expression is set from the two operands in the normal way, | |
4789 | -- and we check the right operand if it is in a non-static context. | |
4790 | ||
4791 | elsif Raises_Constraint_Error (Op1) then | |
4792 | if not Rstat then | |
4793 | Check_Non_Static_Context (Op2); | |
4794 | end if; | |
4795 | ||
4796 | Rewrite_In_Raise_CE (N, Op1); | |
4797 | Set_Is_Static_Expression (N, Rstat); | |
996ae0b0 RK |
4798 | return; |
4799 | ||
4800 | -- Similar processing for the case of the right operand. Note that | |
4801 | -- we don't use this routine for the short-circuit case, so we do | |
4802 | -- not have to worry about that special case here. | |
4803 | ||
4804 | elsif Raises_Constraint_Error (Op2) then | |
4805 | if not Rstat then | |
4806 | Check_Non_Static_Context (Op1); | |
4807 | end if; | |
4808 | ||
4809 | Rewrite_In_Raise_CE (N, Op2); | |
4810 | Set_Is_Static_Expression (N, Rstat); | |
996ae0b0 RK |
4811 | return; |
4812 | ||
82c80734 | 4813 | -- Exclude expressions of a generic modular type, as above |
996ae0b0 RK |
4814 | |
4815 | elsif Is_Modular_Integer_Type (Etype (Op1)) | |
4816 | and then Is_Generic_Type (Etype (Op1)) | |
4817 | then | |
4818 | Check_Non_Static_Context (Op1); | |
996ae0b0 RK |
4819 | return; |
4820 | ||
4821 | -- If result is not static, then check non-static contexts on operands | |
4822 | -- since one of them may be static and the other one may not be static | |
4823 | ||
4824 | elsif not Rstat then | |
4825 | Check_Non_Static_Context (Op1); | |
4826 | Check_Non_Static_Context (Op2); | |
4827 | Fold := Compile_Time_Known_Value (Op1) | |
4828 | and then Compile_Time_Known_Value (Op2); | |
4829 | return; | |
4830 | ||
4831 | -- Else result is static and foldable. Both operands are static, | |
4832 | -- and neither raises constraint error, so we can definitely fold. | |
4833 | ||
4834 | else | |
4835 | Set_Is_Static_Expression (N); | |
4836 | Fold := True; | |
4837 | Stat := True; | |
4838 | return; | |
4839 | end if; | |
4840 | end Test_Expression_Is_Foldable; | |
4841 | ||
4842 | -------------- | |
4843 | -- To_Bits -- | |
4844 | -------------- | |
4845 | ||
4846 | procedure To_Bits (U : Uint; B : out Bits) is | |
4847 | begin | |
4848 | for J in 0 .. B'Last loop | |
4849 | B (J) := (U / (2 ** J)) mod 2 /= 0; | |
4850 | end loop; | |
4851 | end To_Bits; | |
4852 | ||
fbf5a39b AC |
4853 | -------------------- |
4854 | -- Why_Not_Static -- | |
4855 | -------------------- | |
4856 | ||
4857 | procedure Why_Not_Static (Expr : Node_Id) is | |
4858 | N : constant Node_Id := Original_Node (Expr); | |
4859 | Typ : Entity_Id; | |
4860 | E : Entity_Id; | |
4861 | ||
4862 | procedure Why_Not_Static_List (L : List_Id); | |
4863 | -- A version that can be called on a list of expressions. Finds | |
4864 | -- all non-static violations in any element of the list. | |
4865 | ||
4866 | ------------------------- | |
4867 | -- Why_Not_Static_List -- | |
4868 | ------------------------- | |
4869 | ||
4870 | procedure Why_Not_Static_List (L : List_Id) is | |
4871 | N : Node_Id; | |
4872 | ||
4873 | begin | |
4874 | if Is_Non_Empty_List (L) then | |
4875 | N := First (L); | |
4876 | while Present (N) loop | |
4877 | Why_Not_Static (N); | |
4878 | Next (N); | |
4879 | end loop; | |
4880 | end if; | |
4881 | end Why_Not_Static_List; | |
4882 | ||
4883 | -- Start of processing for Why_Not_Static | |
4884 | ||
4885 | begin | |
4886 | -- If in ACATS mode (debug flag 2), then suppress all these | |
4887 | -- messages, this avoids massive updates to the ACATS base line. | |
4888 | ||
4889 | if Debug_Flag_2 then | |
4890 | return; | |
4891 | end if; | |
4892 | ||
4893 | -- Ignore call on error or empty node | |
4894 | ||
4895 | if No (Expr) or else Nkind (Expr) = N_Error then | |
4896 | return; | |
4897 | end if; | |
4898 | ||
4899 | -- Preprocessing for sub expressions | |
4900 | ||
4901 | if Nkind (Expr) in N_Subexpr then | |
4902 | ||
4903 | -- Nothing to do if expression is static | |
4904 | ||
4905 | if Is_OK_Static_Expression (Expr) then | |
4906 | return; | |
4907 | end if; | |
4908 | ||
4909 | -- Test for constraint error raised | |
4910 | ||
4911 | if Raises_Constraint_Error (Expr) then | |
4912 | Error_Msg_N | |
4913 | ("expression raises exception, cannot be static " & | |
b11e8d6f | 4914 | "(RM 4.9(34))!", N); |
fbf5a39b AC |
4915 | return; |
4916 | end if; | |
4917 | ||
4918 | -- If no type, then something is pretty wrong, so ignore | |
4919 | ||
4920 | Typ := Etype (Expr); | |
4921 | ||
4922 | if No (Typ) then | |
4923 | return; | |
4924 | end if; | |
4925 | ||
4926 | -- Type must be scalar or string type | |
4927 | ||
4928 | if not Is_Scalar_Type (Typ) | |
4929 | and then not Is_String_Type (Typ) | |
4930 | then | |
4931 | Error_Msg_N | |
4932 | ("static expression must have scalar or string type " & | |
b11e8d6f | 4933 | "(RM 4.9(2))!", N); |
fbf5a39b AC |
4934 | return; |
4935 | end if; | |
4936 | end if; | |
4937 | ||
4938 | -- If we got through those checks, test particular node kind | |
4939 | ||
4940 | case Nkind (N) is | |
4941 | when N_Expanded_Name | N_Identifier | N_Operator_Symbol => | |
4942 | E := Entity (N); | |
4943 | ||
4944 | if Is_Named_Number (E) then | |
4945 | null; | |
4946 | ||
4947 | elsif Ekind (E) = E_Constant then | |
4948 | if not Is_Static_Expression (Constant_Value (E)) then | |
4949 | Error_Msg_NE | |
b11e8d6f | 4950 | ("& is not a static constant (RM 4.9(5))!", N, E); |
fbf5a39b AC |
4951 | end if; |
4952 | ||
4953 | else | |
4954 | Error_Msg_NE | |
4955 | ("& is not static constant or named number " & | |
b11e8d6f | 4956 | "(RM 4.9(5))!", N, E); |
fbf5a39b AC |
4957 | end if; |
4958 | ||
514d0fc5 | 4959 | when N_Binary_Op | N_Short_Circuit | N_Membership_Test => |
fbf5a39b AC |
4960 | if Nkind (N) in N_Op_Shift then |
4961 | Error_Msg_N | |
b11e8d6f | 4962 | ("shift functions are never static (RM 4.9(6,18))!", N); |
fbf5a39b AC |
4963 | |
4964 | else | |
4965 | Why_Not_Static (Left_Opnd (N)); | |
4966 | Why_Not_Static (Right_Opnd (N)); | |
4967 | end if; | |
4968 | ||
4969 | when N_Unary_Op => | |
4970 | Why_Not_Static (Right_Opnd (N)); | |
4971 | ||
4972 | when N_Attribute_Reference => | |
4973 | Why_Not_Static_List (Expressions (N)); | |
4974 | ||
4975 | E := Etype (Prefix (N)); | |
4976 | ||
4977 | if E = Standard_Void_Type then | |
4978 | return; | |
4979 | end if; | |
4980 | ||
4981 | -- Special case non-scalar'Size since this is a common error | |
4982 | ||
4983 | if Attribute_Name (N) = Name_Size then | |
4984 | Error_Msg_N | |
4985 | ("size attribute is only static for scalar type " & | |
b11e8d6f | 4986 | "(RM 4.9(7,8))", N); |
fbf5a39b AC |
4987 | |
4988 | -- Flag array cases | |
4989 | ||
4990 | elsif Is_Array_Type (E) then | |
4991 | if Attribute_Name (N) /= Name_First | |
4992 | and then | |
4993 | Attribute_Name (N) /= Name_Last | |
4994 | and then | |
4995 | Attribute_Name (N) /= Name_Length | |
4996 | then | |
4997 | Error_Msg_N | |
4998 | ("static array attribute must be Length, First, or Last " & | |
b11e8d6f | 4999 | "(RM 4.9(8))!", N); |
fbf5a39b AC |
5000 | |
5001 | -- Since we know the expression is not-static (we already | |
5002 | -- tested for this, must mean array is not static). | |
5003 | ||
5004 | else | |
5005 | Error_Msg_N | |
b11e8d6f | 5006 | ("prefix is non-static array (RM 4.9(8))!", Prefix (N)); |
fbf5a39b AC |
5007 | end if; |
5008 | ||
5009 | return; | |
5010 | ||
5011 | -- Special case generic types, since again this is a common | |
5012 | -- source of confusion. | |
5013 | ||
5014 | elsif Is_Generic_Actual_Type (E) | |
5015 | or else | |
5016 | Is_Generic_Type (E) | |
5017 | then | |
5018 | Error_Msg_N | |
5019 | ("attribute of generic type is never static " & | |
b11e8d6f | 5020 | "(RM 4.9(7,8))!", N); |
fbf5a39b AC |
5021 | |
5022 | elsif Is_Static_Subtype (E) then | |
5023 | null; | |
5024 | ||
5025 | elsif Is_Scalar_Type (E) then | |
5026 | Error_Msg_N | |
5027 | ("prefix type for attribute is not static scalar subtype " & | |
b11e8d6f | 5028 | "(RM 4.9(7))!", N); |
fbf5a39b AC |
5029 | |
5030 | else | |
5031 | Error_Msg_N | |
5032 | ("static attribute must apply to array/scalar type " & | |
b11e8d6f | 5033 | "(RM 4.9(7,8))!", N); |
fbf5a39b AC |
5034 | end if; |
5035 | ||
5036 | when N_String_Literal => | |
5037 | Error_Msg_N | |
b11e8d6f | 5038 | ("subtype of string literal is non-static (RM 4.9(4))!", N); |
fbf5a39b AC |
5039 | |
5040 | when N_Explicit_Dereference => | |
5041 | Error_Msg_N | |
b11e8d6f | 5042 | ("explicit dereference is never static (RM 4.9)!", N); |
fbf5a39b AC |
5043 | |
5044 | when N_Function_Call => | |
5045 | Why_Not_Static_List (Parameter_Associations (N)); | |
b11e8d6f | 5046 | Error_Msg_N ("non-static function call (RM 4.9(6,18))!", N); |
fbf5a39b AC |
5047 | |
5048 | when N_Parameter_Association => | |
5049 | Why_Not_Static (Explicit_Actual_Parameter (N)); | |
5050 | ||
5051 | when N_Indexed_Component => | |
5052 | Error_Msg_N | |
b11e8d6f | 5053 | ("indexed component is never static (RM 4.9)!", N); |
fbf5a39b AC |
5054 | |
5055 | when N_Procedure_Call_Statement => | |
5056 | Error_Msg_N | |
b11e8d6f | 5057 | ("procedure call is never static (RM 4.9)!", N); |
fbf5a39b AC |
5058 | |
5059 | when N_Qualified_Expression => | |
5060 | Why_Not_Static (Expression (N)); | |
5061 | ||
5062 | when N_Aggregate | N_Extension_Aggregate => | |
5063 | Error_Msg_N | |
b11e8d6f | 5064 | ("an aggregate is never static (RM 4.9)!", N); |
fbf5a39b AC |
5065 | |
5066 | when N_Range => | |
5067 | Why_Not_Static (Low_Bound (N)); | |
5068 | Why_Not_Static (High_Bound (N)); | |
5069 | ||
5070 | when N_Range_Constraint => | |
5071 | Why_Not_Static (Range_Expression (N)); | |
5072 | ||
5073 | when N_Subtype_Indication => | |
5074 | Why_Not_Static (Constraint (N)); | |
5075 | ||
5076 | when N_Selected_Component => | |
5077 | Error_Msg_N | |
b11e8d6f | 5078 | ("selected component is never static (RM 4.9)!", N); |
fbf5a39b AC |
5079 | |
5080 | when N_Slice => | |
5081 | Error_Msg_N | |
b11e8d6f | 5082 | ("slice is never static (RM 4.9)!", N); |
fbf5a39b AC |
5083 | |
5084 | when N_Type_Conversion => | |
5085 | Why_Not_Static (Expression (N)); | |
5086 | ||
5087 | if not Is_Scalar_Type (Etype (Prefix (N))) | |
5088 | or else not Is_Static_Subtype (Etype (Prefix (N))) | |
5089 | then | |
5090 | Error_Msg_N | |
5091 | ("static conversion requires static scalar subtype result " & | |
b11e8d6f | 5092 | "(RM 4.9(9))!", N); |
fbf5a39b AC |
5093 | end if; |
5094 | ||
5095 | when N_Unchecked_Type_Conversion => | |
5096 | Error_Msg_N | |
b11e8d6f | 5097 | ("unchecked type conversion is never static (RM 4.9)!", N); |
fbf5a39b AC |
5098 | |
5099 | when others => | |
5100 | null; | |
5101 | ||
5102 | end case; | |
5103 | end Why_Not_Static; | |
5104 | ||
996ae0b0 | 5105 | end Sem_Eval; |