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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 | 426 | |
57036dcc ES |
427 | function Is_Known_Valid_Operand (Opnd : Node_Id) return Boolean; |
428 | -- Even if the context does not assume that values are valid, some | |
429 | -- simple cases can be recognized. | |
430 | ||
996ae0b0 RK |
431 | function Is_Same_Value (L, R : Node_Id) return Boolean; |
432 | -- Returns True iff L and R represent expressions that definitely | |
433 | -- have identical (but not necessarily compile time known) values | |
434 | -- Indeed the caller is expected to have already dealt with the | |
435 | -- cases of compile time known values, so these are not tested here. | |
436 | ||
437 | ----------------------- | |
438 | -- Compare_Decompose -- | |
439 | ----------------------- | |
440 | ||
441 | procedure Compare_Decompose | |
442 | (N : Node_Id; | |
443 | R : out Node_Id; | |
444 | V : out Uint) | |
445 | is | |
446 | begin | |
447 | if Nkind (N) = N_Op_Add | |
448 | and then Nkind (Right_Opnd (N)) = N_Integer_Literal | |
449 | then | |
450 | R := Left_Opnd (N); | |
451 | V := Intval (Right_Opnd (N)); | |
452 | return; | |
453 | ||
454 | elsif Nkind (N) = N_Op_Subtract | |
455 | and then Nkind (Right_Opnd (N)) = N_Integer_Literal | |
456 | then | |
457 | R := Left_Opnd (N); | |
458 | V := UI_Negate (Intval (Right_Opnd (N))); | |
459 | return; | |
460 | ||
461 | elsif Nkind (N) = N_Attribute_Reference then | |
996ae0b0 RK |
462 | if Attribute_Name (N) = Name_Succ then |
463 | R := First (Expressions (N)); | |
464 | V := Uint_1; | |
465 | return; | |
466 | ||
467 | elsif Attribute_Name (N) = Name_Pred then | |
468 | R := First (Expressions (N)); | |
469 | V := Uint_Minus_1; | |
470 | return; | |
471 | end if; | |
472 | end if; | |
473 | ||
474 | R := N; | |
475 | V := Uint_0; | |
476 | end Compare_Decompose; | |
477 | ||
478 | ------------------- | |
479 | -- Compare_Fixup -- | |
480 | ------------------- | |
481 | ||
482 | function Compare_Fixup (N : Node_Id) return Node_Id is | |
483 | Indx : Node_Id; | |
484 | Xtyp : Entity_Id; | |
485 | Subs : Nat; | |
486 | ||
487 | begin | |
488 | if Nkind (N) = N_Attribute_Reference | |
489 | and then (Attribute_Name (N) = Name_First | |
490 | or else | |
491 | Attribute_Name (N) = Name_Last) | |
492 | then | |
493 | Xtyp := Etype (Prefix (N)); | |
494 | ||
495 | -- If we have no type, then just abandon the attempt to do | |
496 | -- a fixup, this is probably the result of some other error. | |
497 | ||
498 | if No (Xtyp) then | |
499 | return N; | |
500 | end if; | |
501 | ||
502 | -- Dereference an access type | |
503 | ||
504 | if Is_Access_Type (Xtyp) then | |
505 | Xtyp := Designated_Type (Xtyp); | |
506 | end if; | |
507 | ||
508 | -- If we don't have an array type at this stage, something | |
509 | -- is peculiar, e.g. another error, and we abandon the attempt | |
510 | -- at a fixup. | |
511 | ||
512 | if not Is_Array_Type (Xtyp) then | |
513 | return N; | |
514 | end if; | |
515 | ||
516 | -- Ignore unconstrained array, since bounds are not meaningful | |
517 | ||
518 | if not Is_Constrained (Xtyp) then | |
519 | return N; | |
520 | end if; | |
521 | ||
c3de5c4c ES |
522 | if Ekind (Xtyp) = E_String_Literal_Subtype then |
523 | if Attribute_Name (N) = Name_First then | |
524 | return String_Literal_Low_Bound (Xtyp); | |
525 | ||
526 | else -- Attribute_Name (N) = Name_Last | |
527 | return Make_Integer_Literal (Sloc (N), | |
528 | Intval => Intval (String_Literal_Low_Bound (Xtyp)) | |
57036dcc | 529 | + String_Literal_Length (Xtyp)); |
c3de5c4c ES |
530 | end if; |
531 | end if; | |
532 | ||
996ae0b0 RK |
533 | -- Find correct index type |
534 | ||
535 | Indx := First_Index (Xtyp); | |
536 | ||
537 | if Present (Expressions (N)) then | |
538 | Subs := UI_To_Int (Expr_Value (First (Expressions (N)))); | |
539 | ||
540 | for J in 2 .. Subs loop | |
541 | Indx := Next_Index (Indx); | |
542 | end loop; | |
543 | end if; | |
544 | ||
545 | Xtyp := Etype (Indx); | |
546 | ||
547 | if Attribute_Name (N) = Name_First then | |
548 | return Type_Low_Bound (Xtyp); | |
549 | ||
550 | else -- Attribute_Name (N) = Name_Last | |
551 | return Type_High_Bound (Xtyp); | |
552 | end if; | |
553 | end if; | |
554 | ||
555 | return N; | |
556 | end Compare_Fixup; | |
557 | ||
57036dcc ES |
558 | ---------------------------- |
559 | -- Is_Known_Valid_Operand -- | |
560 | ---------------------------- | |
561 | ||
562 | function Is_Known_Valid_Operand (Opnd : Node_Id) return Boolean is | |
563 | begin | |
564 | return (Is_Entity_Name (Opnd) | |
565 | and then | |
566 | (Is_Known_Valid (Entity (Opnd)) | |
567 | or else Ekind (Entity (Opnd)) = E_In_Parameter | |
568 | or else | |
569 | (Ekind (Entity (Opnd)) in Object_Kind | |
570 | and then Present (Current_Value (Entity (Opnd)))))) | |
571 | or else Is_OK_Static_Expression (Opnd); | |
572 | end Is_Known_Valid_Operand; | |
573 | ||
996ae0b0 RK |
574 | ------------------- |
575 | -- Is_Same_Value -- | |
576 | ------------------- | |
577 | ||
578 | function Is_Same_Value (L, R : Node_Id) return Boolean is | |
579 | Lf : constant Node_Id := Compare_Fixup (L); | |
580 | Rf : constant Node_Id := Compare_Fixup (R); | |
581 | ||
fbf5a39b | 582 | function Is_Same_Subscript (L, R : List_Id) return Boolean; |
57036dcc ES |
583 | -- L, R are the Expressions values from two attribute nodes for First |
584 | -- or Last attributes. Either may be set to No_List if no expressions | |
585 | -- are present (indicating subscript 1). The result is True if both | |
586 | -- expressions represent the same subscript (note one case is where | |
587 | -- one subscript is missing and the other is explicitly set to 1). | |
fbf5a39b AC |
588 | |
589 | ----------------------- | |
590 | -- Is_Same_Subscript -- | |
591 | ----------------------- | |
592 | ||
593 | function Is_Same_Subscript (L, R : List_Id) return Boolean is | |
594 | begin | |
595 | if L = No_List then | |
596 | if R = No_List then | |
597 | return True; | |
598 | else | |
599 | return Expr_Value (First (R)) = Uint_1; | |
600 | end if; | |
601 | ||
602 | else | |
603 | if R = No_List then | |
604 | return Expr_Value (First (L)) = Uint_1; | |
605 | else | |
606 | return Expr_Value (First (L)) = Expr_Value (First (R)); | |
607 | end if; | |
608 | end if; | |
609 | end Is_Same_Subscript; | |
610 | ||
611 | -- Start of processing for Is_Same_Value | |
612 | ||
996ae0b0 | 613 | begin |
b49365b2 | 614 | -- Values are the same if they refer to the same entity and the |
c800f862 RD |
615 | -- entity is non-volatile. This does not however apply to Float |
616 | -- types, since we may have two NaN values and they should never | |
617 | -- compare equal. | |
996ae0b0 | 618 | |
b49365b2 RD |
619 | if Nkind_In (Lf, N_Identifier, N_Expanded_Name) |
620 | and then Nkind_In (Rf, N_Identifier, N_Expanded_Name) | |
996ae0b0 | 621 | and then Entity (Lf) = Entity (Rf) |
b49365b2 | 622 | and then Present (Entity (Lf)) |
fbf5a39b | 623 | and then not Is_Floating_Point_Type (Etype (L)) |
c800f862 RD |
624 | and then not Is_Volatile_Reference (L) |
625 | and then not Is_Volatile_Reference (R) | |
996ae0b0 RK |
626 | then |
627 | return True; | |
628 | ||
629 | -- Or if they are compile time known and identical | |
630 | ||
631 | elsif Compile_Time_Known_Value (Lf) | |
632 | and then | |
633 | Compile_Time_Known_Value (Rf) | |
634 | and then Expr_Value (Lf) = Expr_Value (Rf) | |
635 | then | |
636 | return True; | |
637 | ||
b49365b2 RD |
638 | -- False if Nkind of the two nodes is different for remaining cases |
639 | ||
640 | elsif Nkind (Lf) /= Nkind (Rf) then | |
641 | return False; | |
642 | ||
643 | -- True if both 'First or 'Last values applying to the same entity | |
644 | -- (first and last don't change even if value does). Note that we | |
645 | -- need this even with the calls to Compare_Fixup, to handle the | |
646 | -- case of unconstrained array attributes where Compare_Fixup | |
647 | -- cannot find useful bounds. | |
996ae0b0 RK |
648 | |
649 | elsif Nkind (Lf) = N_Attribute_Reference | |
996ae0b0 RK |
650 | and then Attribute_Name (Lf) = Attribute_Name (Rf) |
651 | and then (Attribute_Name (Lf) = Name_First | |
652 | or else | |
653 | Attribute_Name (Lf) = Name_Last) | |
b49365b2 RD |
654 | and then Nkind_In (Prefix (Lf), N_Identifier, N_Expanded_Name) |
655 | and then Nkind_In (Prefix (Rf), N_Identifier, N_Expanded_Name) | |
996ae0b0 | 656 | and then Entity (Prefix (Lf)) = Entity (Prefix (Rf)) |
fbf5a39b | 657 | and then Is_Same_Subscript (Expressions (Lf), Expressions (Rf)) |
996ae0b0 RK |
658 | then |
659 | return True; | |
660 | ||
b49365b2 RD |
661 | -- True if the same selected component from the same record |
662 | ||
663 | elsif Nkind (Lf) = N_Selected_Component | |
664 | and then Selector_Name (Lf) = Selector_Name (Rf) | |
665 | and then Is_Same_Value (Prefix (Lf), Prefix (Rf)) | |
666 | then | |
667 | return True; | |
668 | ||
669 | -- True if the same unary operator applied to the same operand | |
670 | ||
671 | elsif Nkind (Lf) in N_Unary_Op | |
672 | and then Is_Same_Value (Right_Opnd (Lf), Right_Opnd (Rf)) | |
673 | then | |
674 | return True; | |
675 | ||
8682d22c | 676 | -- True if the same binary operator applied to the same operands |
b49365b2 RD |
677 | |
678 | elsif Nkind (Lf) in N_Binary_Op | |
679 | and then Is_Same_Value (Left_Opnd (Lf), Left_Opnd (Rf)) | |
680 | and then Is_Same_Value (Right_Opnd (Lf), Right_Opnd (Rf)) | |
681 | then | |
682 | return True; | |
683 | ||
8682d22c | 684 | -- All other cases, we can't tell, so return False |
996ae0b0 RK |
685 | |
686 | else | |
687 | return False; | |
688 | end if; | |
689 | end Is_Same_Value; | |
690 | ||
691 | -- Start of processing for Compile_Time_Compare | |
692 | ||
693 | begin | |
af02a866 RD |
694 | Diff.all := No_Uint; |
695 | ||
07fc65c4 GB |
696 | -- If either operand could raise constraint error, then we cannot |
697 | -- know the result at compile time (since CE may be raised!) | |
698 | ||
699 | if not (Cannot_Raise_Constraint_Error (L) | |
700 | and then | |
701 | Cannot_Raise_Constraint_Error (R)) | |
702 | then | |
703 | return Unknown; | |
704 | end if; | |
705 | ||
706 | -- Identical operands are most certainly equal | |
707 | ||
996ae0b0 RK |
708 | if L = R then |
709 | return EQ; | |
710 | ||
93c3fca7 AC |
711 | -- If expressions have no types, then do not attempt to determine if |
712 | -- they are the same, since something funny is going on. One case in | |
713 | -- which this happens is during generic template analysis, when bounds | |
714 | -- are not fully analyzed. | |
996ae0b0 RK |
715 | |
716 | elsif No (Ltyp) or else No (Rtyp) then | |
717 | return Unknown; | |
718 | ||
93c3fca7 AC |
719 | -- We do not attempt comparisons for packed arrays arrays represented as |
720 | -- modular types, where the semantics of comparison is quite different. | |
996ae0b0 | 721 | |
93c3fca7 AC |
722 | elsif Is_Packed_Array_Type (Ltyp) |
723 | and then Is_Modular_Integer_Type (Ltyp) | |
996ae0b0 RK |
724 | then |
725 | return Unknown; | |
726 | ||
93c3fca7 | 727 | -- For access types, the only time we know the result at compile time |
f61580d4 | 728 | -- (apart from identical operands, which we handled already) is if we |
93c3fca7 AC |
729 | -- know one operand is null and the other is not, or both operands are |
730 | -- known null. | |
731 | ||
732 | elsif Is_Access_Type (Ltyp) then | |
733 | if Known_Null (L) then | |
734 | if Known_Null (R) then | |
735 | return EQ; | |
736 | elsif Known_Non_Null (R) then | |
737 | return NE; | |
738 | else | |
739 | return Unknown; | |
740 | end if; | |
741 | ||
f61580d4 | 742 | elsif Known_Non_Null (L) and then Known_Null (R) then |
93c3fca7 AC |
743 | return NE; |
744 | ||
745 | else | |
746 | return Unknown; | |
747 | end if; | |
748 | ||
996ae0b0 RK |
749 | -- Case where comparison involves two compile time known values |
750 | ||
751 | elsif Compile_Time_Known_Value (L) | |
752 | and then Compile_Time_Known_Value (R) | |
753 | then | |
754 | -- For the floating-point case, we have to be a little careful, since | |
755 | -- at compile time we are dealing with universal exact values, but at | |
756 | -- runtime, these will be in non-exact target form. That's why the | |
757 | -- returned results are LE and GE below instead of LT and GT. | |
758 | ||
759 | if Is_Floating_Point_Type (Ltyp) | |
760 | or else | |
761 | Is_Floating_Point_Type (Rtyp) | |
762 | then | |
763 | declare | |
764 | Lo : constant Ureal := Expr_Value_R (L); | |
765 | Hi : constant Ureal := Expr_Value_R (R); | |
766 | ||
767 | begin | |
768 | if Lo < Hi then | |
769 | return LE; | |
770 | elsif Lo = Hi then | |
771 | return EQ; | |
772 | else | |
773 | return GE; | |
774 | end if; | |
775 | end; | |
776 | ||
93c3fca7 AC |
777 | -- For string types, we have two string literals and we proceed to |
778 | -- compare them using the Ada style dictionary string comparison. | |
779 | ||
780 | elsif not Is_Scalar_Type (Ltyp) then | |
781 | declare | |
782 | Lstring : constant String_Id := Strval (Expr_Value_S (L)); | |
783 | Rstring : constant String_Id := Strval (Expr_Value_S (R)); | |
784 | Llen : constant Nat := String_Length (Lstring); | |
785 | Rlen : constant Nat := String_Length (Rstring); | |
786 | ||
787 | begin | |
788 | for J in 1 .. Nat'Min (Llen, Rlen) loop | |
789 | declare | |
790 | LC : constant Char_Code := Get_String_Char (Lstring, J); | |
791 | RC : constant Char_Code := Get_String_Char (Rstring, J); | |
792 | begin | |
793 | if LC < RC then | |
794 | return LT; | |
795 | elsif LC > RC then | |
796 | return GT; | |
797 | end if; | |
798 | end; | |
799 | end loop; | |
800 | ||
801 | if Llen < Rlen then | |
802 | return LT; | |
803 | elsif Llen > Rlen then | |
804 | return GT; | |
805 | else | |
806 | return EQ; | |
807 | end if; | |
808 | end; | |
809 | ||
810 | -- For remaining scalar cases we know exactly (note that this does | |
811 | -- include the fixed-point case, where we know the run time integer | |
f61580d4 | 812 | -- values now). |
996ae0b0 RK |
813 | |
814 | else | |
815 | declare | |
816 | Lo : constant Uint := Expr_Value (L); | |
817 | Hi : constant Uint := Expr_Value (R); | |
818 | ||
819 | begin | |
820 | if Lo < Hi then | |
af02a866 | 821 | Diff.all := Hi - Lo; |
996ae0b0 | 822 | return LT; |
af02a866 | 823 | |
996ae0b0 RK |
824 | elsif Lo = Hi then |
825 | return EQ; | |
af02a866 | 826 | |
996ae0b0 | 827 | else |
af02a866 | 828 | Diff.all := Lo - Hi; |
996ae0b0 RK |
829 | return GT; |
830 | end if; | |
831 | end; | |
832 | end if; | |
833 | ||
834 | -- Cases where at least one operand is not known at compile time | |
835 | ||
836 | else | |
93c3fca7 | 837 | -- Remaining checks apply only for discrete types |
29797f34 RD |
838 | |
839 | if not Is_Discrete_Type (Ltyp) | |
840 | or else not Is_Discrete_Type (Rtyp) | |
93c3fca7 AC |
841 | then |
842 | return Unknown; | |
843 | end if; | |
844 | ||
845 | -- Defend against generic types, or actually any expressions that | |
846 | -- contain a reference to a generic type from within a generic | |
847 | -- template. We don't want to do any range analysis of such | |
848 | -- expressions for two reasons. First, the bounds of a generic type | |
849 | -- itself are junk and cannot be used for any kind of analysis. | |
850 | -- Second, we may have a case where the range at run time is indeed | |
851 | -- known, but we don't want to do compile time analysis in the | |
852 | -- template based on that range since in an instance the value may be | |
853 | -- static, and able to be elaborated without reference to the bounds | |
854 | -- of types involved. As an example, consider: | |
855 | ||
856 | -- (F'Pos (F'Last) + 1) > Integer'Last | |
857 | ||
858 | -- The expression on the left side of > is Universal_Integer and thus | |
859 | -- acquires the type Integer for evaluation at run time, and at run | |
860 | -- time it is true that this condition is always False, but within | |
861 | -- an instance F may be a type with a static range greater than the | |
862 | -- range of Integer, and the expression statically evaluates to True. | |
863 | ||
864 | if References_Generic_Formal_Type (L) | |
865 | or else | |
866 | References_Generic_Formal_Type (R) | |
29797f34 RD |
867 | then |
868 | return Unknown; | |
869 | end if; | |
870 | ||
1c7717c3 AC |
871 | -- Replace types by base types for the case of entities which are |
872 | -- not known to have valid representations. This takes care of | |
873 | -- properly dealing with invalid representations. | |
874 | ||
c800f862 | 875 | if not Assume_Valid and then not Assume_No_Invalid_Values then |
1c7717c3 | 876 | if Is_Entity_Name (L) and then not Is_Known_Valid (Entity (L)) then |
93c3fca7 | 877 | Ltyp := Underlying_Type (Base_Type (Ltyp)); |
1c7717c3 AC |
878 | end if; |
879 | ||
880 | if Is_Entity_Name (R) and then not Is_Known_Valid (Entity (R)) then | |
93c3fca7 | 881 | Rtyp := Underlying_Type (Base_Type (Rtyp)); |
1c7717c3 AC |
882 | end if; |
883 | end if; | |
884 | ||
c800f862 RD |
885 | -- Try range analysis on variables and see if ranges are disjoint |
886 | ||
887 | declare | |
888 | LOK, ROK : Boolean; | |
889 | LLo, LHi : Uint; | |
890 | RLo, RHi : Uint; | |
891 | ||
892 | begin | |
893 | Determine_Range (L, LOK, LLo, LHi, Assume_Valid); | |
894 | Determine_Range (R, ROK, RLo, RHi, Assume_Valid); | |
895 | ||
896 | if LOK and ROK then | |
897 | if LHi < RLo then | |
898 | return LT; | |
899 | ||
900 | elsif RHi < LLo then | |
901 | return GT; | |
902 | ||
903 | elsif LLo = LHi | |
904 | and then RLo = RHi | |
905 | and then LLo = RLo | |
906 | then | |
e27b834b | 907 | |
75ba322d AC |
908 | -- If the range includes a single literal and we can assume |
909 | -- validity then the result is known even if an operand is | |
910 | -- not static. | |
e27b834b AC |
911 | |
912 | if Assume_Valid then | |
913 | return EQ; | |
e27b834b AC |
914 | else |
915 | return Unknown; | |
916 | end if; | |
c800f862 RD |
917 | |
918 | elsif LHi = RLo then | |
919 | return LE; | |
920 | ||
921 | elsif RHi = LLo then | |
922 | return GE; | |
57036dcc ES |
923 | |
924 | elsif not Is_Known_Valid_Operand (L) | |
925 | and then not Assume_Valid | |
926 | then | |
927 | if Is_Same_Value (L, R) then | |
928 | return EQ; | |
929 | else | |
930 | return Unknown; | |
931 | end if; | |
c800f862 RD |
932 | end if; |
933 | end if; | |
934 | end; | |
935 | ||
996ae0b0 RK |
936 | -- Here is where we check for comparisons against maximum bounds of |
937 | -- types, where we know that no value can be outside the bounds of | |
938 | -- the subtype. Note that this routine is allowed to assume that all | |
939 | -- expressions are within their subtype bounds. Callers wishing to | |
940 | -- deal with possibly invalid values must in any case take special | |
941 | -- steps (e.g. conversions to larger types) to avoid this kind of | |
942 | -- optimization, which is always considered to be valid. We do not | |
943 | -- attempt this optimization with generic types, since the type | |
944 | -- bounds may not be meaningful in this case. | |
945 | ||
93c3fca7 | 946 | -- We are in danger of an infinite recursion here. It does not seem |
fbf5a39b AC |
947 | -- useful to go more than one level deep, so the parameter Rec is |
948 | -- used to protect ourselves against this infinite recursion. | |
949 | ||
29797f34 RD |
950 | if not Rec then |
951 | ||
fbf5a39b AC |
952 | -- See if we can get a decisive check against one operand and |
953 | -- a bound of the other operand (four possible tests here). | |
93c3fca7 AC |
954 | -- Note that we avoid testing junk bounds of a generic type. |
955 | ||
956 | if not Is_Generic_Type (Rtyp) then | |
957 | case Compile_Time_Compare (L, Type_Low_Bound (Rtyp), | |
958 | Discard'Access, | |
959 | Assume_Valid, Rec => True) | |
960 | is | |
961 | when LT => return LT; | |
962 | when LE => return LE; | |
963 | when EQ => return LE; | |
964 | when others => null; | |
965 | end case; | |
fbf5a39b | 966 | |
93c3fca7 AC |
967 | case Compile_Time_Compare (L, Type_High_Bound (Rtyp), |
968 | Discard'Access, | |
969 | Assume_Valid, Rec => True) | |
970 | is | |
971 | when GT => return GT; | |
972 | when GE => return GE; | |
973 | when EQ => return GE; | |
974 | when others => null; | |
975 | end case; | |
976 | end if; | |
996ae0b0 | 977 | |
93c3fca7 AC |
978 | if not Is_Generic_Type (Ltyp) then |
979 | case Compile_Time_Compare (Type_Low_Bound (Ltyp), R, | |
980 | Discard'Access, | |
981 | Assume_Valid, Rec => True) | |
982 | is | |
983 | when GT => return GT; | |
984 | when GE => return GE; | |
985 | when EQ => return GE; | |
986 | when others => null; | |
987 | end case; | |
996ae0b0 | 988 | |
93c3fca7 AC |
989 | case Compile_Time_Compare (Type_High_Bound (Ltyp), R, |
990 | Discard'Access, | |
991 | Assume_Valid, Rec => True) | |
992 | is | |
993 | when LT => return LT; | |
994 | when LE => return LE; | |
995 | when EQ => return LE; | |
996 | when others => null; | |
997 | end case; | |
998 | end if; | |
996ae0b0 RK |
999 | end if; |
1000 | ||
1001 | -- Next attempt is to decompose the expressions to extract | |
1002 | -- a constant offset resulting from the use of any of the forms: | |
1003 | ||
1004 | -- expr + literal | |
1005 | -- expr - literal | |
1006 | -- typ'Succ (expr) | |
1007 | -- typ'Pred (expr) | |
1008 | ||
1009 | -- Then we see if the two expressions are the same value, and if so | |
1010 | -- the result is obtained by comparing the offsets. | |
1011 | ||
1012 | declare | |
1013 | Lnode : Node_Id; | |
1014 | Loffs : Uint; | |
1015 | Rnode : Node_Id; | |
1016 | Roffs : Uint; | |
1017 | ||
1018 | begin | |
1019 | Compare_Decompose (L, Lnode, Loffs); | |
1020 | Compare_Decompose (R, Rnode, Roffs); | |
1021 | ||
1022 | if Is_Same_Value (Lnode, Rnode) then | |
1023 | if Loffs = Roffs then | |
1024 | return EQ; | |
1025 | ||
1026 | elsif Loffs < Roffs then | |
af02a866 | 1027 | Diff.all := Roffs - Loffs; |
996ae0b0 RK |
1028 | return LT; |
1029 | ||
1030 | else | |
af02a866 | 1031 | Diff.all := Loffs - Roffs; |
996ae0b0 RK |
1032 | return GT; |
1033 | end if; | |
29797f34 RD |
1034 | end if; |
1035 | end; | |
1036 | ||
1037 | -- Next attempt is to see if we have an entity compared with a | |
1038 | -- compile time known value, where there is a current value | |
1039 | -- conditional for the entity which can tell us the result. | |
1040 | ||
1041 | declare | |
1042 | Var : Node_Id; | |
1043 | -- Entity variable (left operand) | |
1044 | ||
1045 | Val : Uint; | |
1046 | -- Value (right operand) | |
1047 | ||
1048 | Inv : Boolean; | |
1049 | -- If False, we have reversed the operands | |
1050 | ||
1051 | Op : Node_Kind; | |
1052 | -- Comparison operator kind from Get_Current_Value_Condition call | |
996ae0b0 | 1053 | |
29797f34 RD |
1054 | Opn : Node_Id; |
1055 | -- Value from Get_Current_Value_Condition call | |
1056 | ||
1057 | Opv : Uint; | |
1058 | -- Value of Opn | |
1059 | ||
1060 | Result : Compare_Result; | |
1061 | -- Known result before inversion | |
1062 | ||
1063 | begin | |
1064 | if Is_Entity_Name (L) | |
1065 | and then Compile_Time_Known_Value (R) | |
1066 | then | |
1067 | Var := L; | |
1068 | Val := Expr_Value (R); | |
1069 | Inv := False; | |
1070 | ||
1071 | elsif Is_Entity_Name (R) | |
1072 | and then Compile_Time_Known_Value (L) | |
1073 | then | |
1074 | Var := R; | |
1075 | Val := Expr_Value (L); | |
1076 | Inv := True; | |
1077 | ||
1078 | -- That was the last chance at finding a compile time result | |
996ae0b0 RK |
1079 | |
1080 | else | |
1081 | return Unknown; | |
1082 | end if; | |
29797f34 RD |
1083 | |
1084 | Get_Current_Value_Condition (Var, Op, Opn); | |
1085 | ||
1086 | -- That was the last chance, so if we got nothing return | |
1087 | ||
1088 | if No (Opn) then | |
1089 | return Unknown; | |
1090 | end if; | |
1091 | ||
1092 | Opv := Expr_Value (Opn); | |
1093 | ||
1094 | -- We got a comparison, so we might have something interesting | |
1095 | ||
1096 | -- Convert LE to LT and GE to GT, just so we have fewer cases | |
1097 | ||
1098 | if Op = N_Op_Le then | |
1099 | Op := N_Op_Lt; | |
1100 | Opv := Opv + 1; | |
af02a866 | 1101 | |
29797f34 RD |
1102 | elsif Op = N_Op_Ge then |
1103 | Op := N_Op_Gt; | |
1104 | Opv := Opv - 1; | |
1105 | end if; | |
1106 | ||
1107 | -- Deal with equality case | |
1108 | ||
1109 | if Op = N_Op_Eq then | |
1110 | if Val = Opv then | |
1111 | Result := EQ; | |
1112 | elsif Opv < Val then | |
1113 | Result := LT; | |
1114 | else | |
1115 | Result := GT; | |
1116 | end if; | |
1117 | ||
1118 | -- Deal with inequality case | |
1119 | ||
1120 | elsif Op = N_Op_Ne then | |
1121 | if Val = Opv then | |
1122 | Result := NE; | |
1123 | else | |
1124 | return Unknown; | |
1125 | end if; | |
1126 | ||
1127 | -- Deal with greater than case | |
1128 | ||
1129 | elsif Op = N_Op_Gt then | |
1130 | if Opv >= Val then | |
1131 | Result := GT; | |
1132 | elsif Opv = Val - 1 then | |
1133 | Result := GE; | |
1134 | else | |
1135 | return Unknown; | |
1136 | end if; | |
1137 | ||
1138 | -- Deal with less than case | |
1139 | ||
1140 | else pragma Assert (Op = N_Op_Lt); | |
1141 | if Opv <= Val then | |
1142 | Result := LT; | |
1143 | elsif Opv = Val + 1 then | |
1144 | Result := LE; | |
1145 | else | |
1146 | return Unknown; | |
1147 | end if; | |
1148 | end if; | |
1149 | ||
1150 | -- Deal with inverting result | |
1151 | ||
1152 | if Inv then | |
1153 | case Result is | |
1154 | when GT => return LT; | |
1155 | when GE => return LE; | |
1156 | when LT => return GT; | |
1157 | when LE => return GE; | |
1158 | when others => return Result; | |
1159 | end case; | |
1160 | end if; | |
1161 | ||
1162 | return Result; | |
996ae0b0 RK |
1163 | end; |
1164 | end if; | |
1165 | end Compile_Time_Compare; | |
1166 | ||
f44fe430 RD |
1167 | ------------------------------- |
1168 | -- Compile_Time_Known_Bounds -- | |
1169 | ------------------------------- | |
1170 | ||
1171 | function Compile_Time_Known_Bounds (T : Entity_Id) return Boolean is | |
1172 | Indx : Node_Id; | |
1173 | Typ : Entity_Id; | |
1174 | ||
1175 | begin | |
1176 | if not Is_Array_Type (T) then | |
1177 | return False; | |
1178 | end if; | |
1179 | ||
1180 | Indx := First_Index (T); | |
1181 | while Present (Indx) loop | |
1182 | Typ := Underlying_Type (Etype (Indx)); | |
93c3fca7 AC |
1183 | |
1184 | -- Never look at junk bounds of a generic type | |
1185 | ||
1186 | if Is_Generic_Type (Typ) then | |
1187 | return False; | |
1188 | end if; | |
1189 | ||
1190 | -- Otherwise check bounds for compile time known | |
1191 | ||
f44fe430 RD |
1192 | if not Compile_Time_Known_Value (Type_Low_Bound (Typ)) then |
1193 | return False; | |
1194 | elsif not Compile_Time_Known_Value (Type_High_Bound (Typ)) then | |
1195 | return False; | |
1196 | else | |
1197 | Next_Index (Indx); | |
1198 | end if; | |
1199 | end loop; | |
1200 | ||
1201 | return True; | |
1202 | end Compile_Time_Known_Bounds; | |
1203 | ||
996ae0b0 RK |
1204 | ------------------------------ |
1205 | -- Compile_Time_Known_Value -- | |
1206 | ------------------------------ | |
1207 | ||
1208 | function Compile_Time_Known_Value (Op : Node_Id) return Boolean is | |
07fc65c4 GB |
1209 | K : constant Node_Kind := Nkind (Op); |
1210 | CV_Ent : CV_Entry renames CV_Cache (Nat (Op) mod CV_Cache_Size); | |
996ae0b0 RK |
1211 | |
1212 | begin | |
1213 | -- Never known at compile time if bad type or raises constraint error | |
1214 | -- or empty (latter case occurs only as a result of a previous error) | |
1215 | ||
1216 | if No (Op) | |
1217 | or else Op = Error | |
1218 | or else Etype (Op) = Any_Type | |
1219 | or else Raises_Constraint_Error (Op) | |
1220 | then | |
1221 | return False; | |
1222 | end if; | |
1223 | ||
597d7158 GD |
1224 | -- If this is not a static expression or a null literal, and we are in |
1225 | -- configurable run-time mode, then we consider it not known at compile | |
1226 | -- time. This avoids anomalies where whether something is allowed with a | |
1227 | -- given configurable run-time library depends on how good the compiler | |
1228 | -- is at optimizing and knowing that things are constant when they are | |
1229 | -- nonstatic. | |
1230 | ||
1231 | if Configurable_Run_Time_Mode | |
1232 | and then K /= N_Null | |
1233 | and then not Is_Static_Expression (Op) | |
1234 | then | |
fbf5a39b AC |
1235 | return False; |
1236 | end if; | |
1237 | ||
996ae0b0 RK |
1238 | -- If we have an entity name, then see if it is the name of a constant |
1239 | -- and if so, test the corresponding constant value, or the name of | |
1240 | -- an enumeration literal, which is always a constant. | |
1241 | ||
1242 | if Present (Etype (Op)) and then Is_Entity_Name (Op) then | |
1243 | declare | |
1244 | E : constant Entity_Id := Entity (Op); | |
1245 | V : Node_Id; | |
1246 | ||
1247 | begin | |
1248 | -- Never known at compile time if it is a packed array value. | |
1249 | -- We might want to try to evaluate these at compile time one | |
1250 | -- day, but we do not make that attempt now. | |
1251 | ||
1252 | if Is_Packed_Array_Type (Etype (Op)) then | |
1253 | return False; | |
1254 | end if; | |
1255 | ||
1256 | if Ekind (E) = E_Enumeration_Literal then | |
1257 | return True; | |
1258 | ||
07fc65c4 | 1259 | elsif Ekind (E) = E_Constant then |
996ae0b0 RK |
1260 | V := Constant_Value (E); |
1261 | return Present (V) and then Compile_Time_Known_Value (V); | |
1262 | end if; | |
1263 | end; | |
1264 | ||
1265 | -- We have a value, see if it is compile time known | |
1266 | ||
1267 | else | |
07fc65c4 | 1268 | -- Integer literals are worth storing in the cache |
996ae0b0 | 1269 | |
07fc65c4 GB |
1270 | if K = N_Integer_Literal then |
1271 | CV_Ent.N := Op; | |
1272 | CV_Ent.V := Intval (Op); | |
1273 | return True; | |
1274 | ||
1275 | -- Other literals and NULL are known at compile time | |
1276 | ||
1277 | elsif | |
996ae0b0 RK |
1278 | K = N_Character_Literal |
1279 | or else | |
1280 | K = N_Real_Literal | |
1281 | or else | |
1282 | K = N_String_Literal | |
1283 | or else | |
1284 | K = N_Null | |
1285 | then | |
1286 | return True; | |
1287 | ||
1288 | -- Any reference to Null_Parameter is known at compile time. No | |
1289 | -- other attribute references (that have not already been folded) | |
1290 | -- are known at compile time. | |
1291 | ||
1292 | elsif K = N_Attribute_Reference then | |
1293 | return Attribute_Name (Op) = Name_Null_Parameter; | |
07fc65c4 | 1294 | end if; |
996ae0b0 | 1295 | end if; |
07fc65c4 GB |
1296 | |
1297 | -- If we fall through, not known at compile time | |
1298 | ||
1299 | return False; | |
1300 | ||
1301 | -- If we get an exception while trying to do this test, then some error | |
1302 | -- has occurred, and we simply say that the value is not known after all | |
1303 | ||
1304 | exception | |
1305 | when others => | |
1306 | return False; | |
996ae0b0 RK |
1307 | end Compile_Time_Known_Value; |
1308 | ||
1309 | -------------------------------------- | |
1310 | -- Compile_Time_Known_Value_Or_Aggr -- | |
1311 | -------------------------------------- | |
1312 | ||
1313 | function Compile_Time_Known_Value_Or_Aggr (Op : Node_Id) return Boolean is | |
1314 | begin | |
1315 | -- If we have an entity name, then see if it is the name of a constant | |
1316 | -- and if so, test the corresponding constant value, or the name of | |
1317 | -- an enumeration literal, which is always a constant. | |
1318 | ||
1319 | if Is_Entity_Name (Op) then | |
1320 | declare | |
1321 | E : constant Entity_Id := Entity (Op); | |
1322 | V : Node_Id; | |
1323 | ||
1324 | begin | |
1325 | if Ekind (E) = E_Enumeration_Literal then | |
1326 | return True; | |
1327 | ||
1328 | elsif Ekind (E) /= E_Constant then | |
1329 | return False; | |
1330 | ||
1331 | else | |
1332 | V := Constant_Value (E); | |
1333 | return Present (V) | |
1334 | and then Compile_Time_Known_Value_Or_Aggr (V); | |
1335 | end if; | |
1336 | end; | |
1337 | ||
1338 | -- We have a value, see if it is compile time known | |
1339 | ||
1340 | else | |
1341 | if Compile_Time_Known_Value (Op) then | |
1342 | return True; | |
1343 | ||
1344 | elsif Nkind (Op) = N_Aggregate then | |
1345 | ||
1346 | if Present (Expressions (Op)) then | |
1347 | declare | |
1348 | Expr : Node_Id; | |
1349 | ||
1350 | begin | |
1351 | Expr := First (Expressions (Op)); | |
1352 | while Present (Expr) loop | |
1353 | if not Compile_Time_Known_Value_Or_Aggr (Expr) then | |
1354 | return False; | |
1355 | end if; | |
1356 | ||
1357 | Next (Expr); | |
1358 | end loop; | |
1359 | end; | |
1360 | end if; | |
1361 | ||
1362 | if Present (Component_Associations (Op)) then | |
1363 | declare | |
1364 | Cass : Node_Id; | |
1365 | ||
1366 | begin | |
1367 | Cass := First (Component_Associations (Op)); | |
1368 | while Present (Cass) loop | |
1369 | if not | |
1370 | Compile_Time_Known_Value_Or_Aggr (Expression (Cass)) | |
1371 | then | |
1372 | return False; | |
1373 | end if; | |
1374 | ||
1375 | Next (Cass); | |
1376 | end loop; | |
1377 | end; | |
1378 | end if; | |
1379 | ||
1380 | return True; | |
1381 | ||
1382 | -- All other types of values are not known at compile time | |
1383 | ||
1384 | else | |
1385 | return False; | |
1386 | end if; | |
1387 | ||
1388 | end if; | |
1389 | end Compile_Time_Known_Value_Or_Aggr; | |
1390 | ||
1391 | ----------------- | |
1392 | -- Eval_Actual -- | |
1393 | ----------------- | |
1394 | ||
1395 | -- This is only called for actuals of functions that are not predefined | |
1396 | -- operators (which have already been rewritten as operators at this | |
1397 | -- stage), so the call can never be folded, and all that needs doing for | |
1398 | -- the actual is to do the check for a non-static context. | |
1399 | ||
1400 | procedure Eval_Actual (N : Node_Id) is | |
1401 | begin | |
1402 | Check_Non_Static_Context (N); | |
1403 | end Eval_Actual; | |
1404 | ||
1405 | -------------------- | |
1406 | -- Eval_Allocator -- | |
1407 | -------------------- | |
1408 | ||
1409 | -- Allocators are never static, so all we have to do is to do the | |
1410 | -- check for a non-static context if an expression is present. | |
1411 | ||
1412 | procedure Eval_Allocator (N : Node_Id) is | |
1413 | Expr : constant Node_Id := Expression (N); | |
1414 | ||
1415 | begin | |
1416 | if Nkind (Expr) = N_Qualified_Expression then | |
1417 | Check_Non_Static_Context (Expression (Expr)); | |
1418 | end if; | |
1419 | end Eval_Allocator; | |
1420 | ||
1421 | ------------------------ | |
1422 | -- Eval_Arithmetic_Op -- | |
1423 | ------------------------ | |
1424 | ||
1425 | -- Arithmetic operations are static functions, so the result is static | |
1426 | -- if both operands are static (RM 4.9(7), 4.9(20)). | |
1427 | ||
1428 | procedure Eval_Arithmetic_Op (N : Node_Id) is | |
1429 | Left : constant Node_Id := Left_Opnd (N); | |
1430 | Right : constant Node_Id := Right_Opnd (N); | |
1431 | Ltype : constant Entity_Id := Etype (Left); | |
1432 | Rtype : constant Entity_Id := Etype (Right); | |
1433 | Stat : Boolean; | |
1434 | Fold : Boolean; | |
1435 | ||
1436 | begin | |
1437 | -- If not foldable we are done | |
1438 | ||
1439 | Test_Expression_Is_Foldable (N, Left, Right, Stat, Fold); | |
1440 | ||
1441 | if not Fold then | |
1442 | return; | |
1443 | end if; | |
1444 | ||
1445 | -- Fold for cases where both operands are of integer type | |
1446 | ||
1447 | if Is_Integer_Type (Ltype) and then Is_Integer_Type (Rtype) then | |
1448 | declare | |
1449 | Left_Int : constant Uint := Expr_Value (Left); | |
1450 | Right_Int : constant Uint := Expr_Value (Right); | |
1451 | Result : Uint; | |
1452 | ||
1453 | begin | |
1454 | case Nkind (N) is | |
1455 | ||
1456 | when N_Op_Add => | |
1457 | Result := Left_Int + Right_Int; | |
1458 | ||
1459 | when N_Op_Subtract => | |
1460 | Result := Left_Int - Right_Int; | |
1461 | ||
1462 | when N_Op_Multiply => | |
1463 | if OK_Bits | |
1464 | (N, UI_From_Int | |
1465 | (Num_Bits (Left_Int) + Num_Bits (Right_Int))) | |
1466 | then | |
1467 | Result := Left_Int * Right_Int; | |
1468 | else | |
1469 | Result := Left_Int; | |
1470 | end if; | |
1471 | ||
1472 | when N_Op_Divide => | |
1473 | ||
1474 | -- The exception Constraint_Error is raised by integer | |
1475 | -- division, rem and mod if the right operand is zero. | |
1476 | ||
1477 | if Right_Int = 0 then | |
1478 | Apply_Compile_Time_Constraint_Error | |
fbf5a39b AC |
1479 | (N, "division by zero", |
1480 | CE_Divide_By_Zero, | |
1481 | Warn => not Stat); | |
996ae0b0 | 1482 | return; |
fbf5a39b | 1483 | |
996ae0b0 RK |
1484 | else |
1485 | Result := Left_Int / Right_Int; | |
1486 | end if; | |
1487 | ||
1488 | when N_Op_Mod => | |
1489 | ||
1490 | -- The exception Constraint_Error is raised by integer | |
1491 | -- division, rem and mod if the right operand is zero. | |
1492 | ||
1493 | if Right_Int = 0 then | |
1494 | Apply_Compile_Time_Constraint_Error | |
fbf5a39b AC |
1495 | (N, "mod with zero divisor", |
1496 | CE_Divide_By_Zero, | |
1497 | Warn => not Stat); | |
996ae0b0 RK |
1498 | return; |
1499 | else | |
1500 | Result := Left_Int mod Right_Int; | |
1501 | end if; | |
1502 | ||
1503 | when N_Op_Rem => | |
1504 | ||
1505 | -- The exception Constraint_Error is raised by integer | |
1506 | -- division, rem and mod if the right operand is zero. | |
1507 | ||
1508 | if Right_Int = 0 then | |
1509 | Apply_Compile_Time_Constraint_Error | |
fbf5a39b AC |
1510 | (N, "rem with zero divisor", |
1511 | CE_Divide_By_Zero, | |
1512 | Warn => not Stat); | |
996ae0b0 | 1513 | return; |
fbf5a39b | 1514 | |
996ae0b0 RK |
1515 | else |
1516 | Result := Left_Int rem Right_Int; | |
1517 | end if; | |
1518 | ||
1519 | when others => | |
1520 | raise Program_Error; | |
1521 | end case; | |
1522 | ||
1523 | -- Adjust the result by the modulus if the type is a modular type | |
1524 | ||
1525 | if Is_Modular_Integer_Type (Ltype) then | |
1526 | Result := Result mod Modulus (Ltype); | |
82c80734 RD |
1527 | |
1528 | -- For a signed integer type, check non-static overflow | |
1529 | ||
1530 | elsif (not Stat) and then Is_Signed_Integer_Type (Ltype) then | |
1531 | declare | |
1532 | BT : constant Entity_Id := Base_Type (Ltype); | |
1533 | Lo : constant Uint := Expr_Value (Type_Low_Bound (BT)); | |
1534 | Hi : constant Uint := Expr_Value (Type_High_Bound (BT)); | |
1535 | begin | |
1536 | if Result < Lo or else Result > Hi then | |
1537 | Apply_Compile_Time_Constraint_Error | |
1538 | (N, "value not in range of }?", | |
1539 | CE_Overflow_Check_Failed, | |
1540 | Ent => BT); | |
1541 | return; | |
1542 | end if; | |
1543 | end; | |
996ae0b0 RK |
1544 | end if; |
1545 | ||
82c80734 RD |
1546 | -- If we get here we can fold the result |
1547 | ||
fbf5a39b | 1548 | Fold_Uint (N, Result, Stat); |
996ae0b0 RK |
1549 | end; |
1550 | ||
1551 | -- Cases where at least one operand is a real. We handle the cases | |
1552 | -- of both reals, or mixed/real integer cases (the latter happen | |
1553 | -- only for divide and multiply, and the result is always real). | |
1554 | ||
1555 | elsif Is_Real_Type (Ltype) or else Is_Real_Type (Rtype) then | |
1556 | declare | |
1557 | Left_Real : Ureal; | |
1558 | Right_Real : Ureal; | |
1559 | Result : Ureal; | |
1560 | ||
1561 | begin | |
1562 | if Is_Real_Type (Ltype) then | |
1563 | Left_Real := Expr_Value_R (Left); | |
1564 | else | |
1565 | Left_Real := UR_From_Uint (Expr_Value (Left)); | |
1566 | end if; | |
1567 | ||
1568 | if Is_Real_Type (Rtype) then | |
1569 | Right_Real := Expr_Value_R (Right); | |
1570 | else | |
1571 | Right_Real := UR_From_Uint (Expr_Value (Right)); | |
1572 | end if; | |
1573 | ||
1574 | if Nkind (N) = N_Op_Add then | |
1575 | Result := Left_Real + Right_Real; | |
1576 | ||
1577 | elsif Nkind (N) = N_Op_Subtract then | |
1578 | Result := Left_Real - Right_Real; | |
1579 | ||
1580 | elsif Nkind (N) = N_Op_Multiply then | |
1581 | Result := Left_Real * Right_Real; | |
1582 | ||
1583 | else pragma Assert (Nkind (N) = N_Op_Divide); | |
1584 | if UR_Is_Zero (Right_Real) then | |
1585 | Apply_Compile_Time_Constraint_Error | |
07fc65c4 | 1586 | (N, "division by zero", CE_Divide_By_Zero); |
996ae0b0 RK |
1587 | return; |
1588 | end if; | |
1589 | ||
1590 | Result := Left_Real / Right_Real; | |
1591 | end if; | |
1592 | ||
fbf5a39b | 1593 | Fold_Ureal (N, Result, Stat); |
996ae0b0 RK |
1594 | end; |
1595 | end if; | |
996ae0b0 RK |
1596 | end Eval_Arithmetic_Op; |
1597 | ||
1598 | ---------------------------- | |
1599 | -- Eval_Character_Literal -- | |
1600 | ---------------------------- | |
1601 | ||
1602 | -- Nothing to be done! | |
1603 | ||
1604 | procedure Eval_Character_Literal (N : Node_Id) is | |
07fc65c4 | 1605 | pragma Warnings (Off, N); |
996ae0b0 RK |
1606 | begin |
1607 | null; | |
1608 | end Eval_Character_Literal; | |
1609 | ||
c01a9391 AC |
1610 | --------------- |
1611 | -- Eval_Call -- | |
1612 | --------------- | |
1613 | ||
1614 | -- Static function calls are either calls to predefined operators | |
1615 | -- with static arguments, or calls to functions that rename a literal. | |
1616 | -- Only the latter case is handled here, predefined operators are | |
1617 | -- constant-folded elsewhere. | |
29797f34 | 1618 | |
c01a9391 AC |
1619 | -- If the function is itself inherited (see 7423-001) the literal of |
1620 | -- the parent type must be explicitly converted to the return type | |
1621 | -- of the function. | |
1622 | ||
1623 | procedure Eval_Call (N : Node_Id) is | |
1624 | Loc : constant Source_Ptr := Sloc (N); | |
1625 | Typ : constant Entity_Id := Etype (N); | |
1626 | Lit : Entity_Id; | |
1627 | ||
1628 | begin | |
1629 | if Nkind (N) = N_Function_Call | |
1630 | and then No (Parameter_Associations (N)) | |
1631 | and then Is_Entity_Name (Name (N)) | |
1632 | and then Present (Alias (Entity (Name (N)))) | |
1633 | and then Is_Enumeration_Type (Base_Type (Typ)) | |
1634 | then | |
1635 | Lit := Alias (Entity (Name (N))); | |
c01a9391 AC |
1636 | while Present (Alias (Lit)) loop |
1637 | Lit := Alias (Lit); | |
1638 | end loop; | |
1639 | ||
1640 | if Ekind (Lit) = E_Enumeration_Literal then | |
1641 | if Base_Type (Etype (Lit)) /= Base_Type (Typ) then | |
1642 | Rewrite | |
1643 | (N, Convert_To (Typ, New_Occurrence_Of (Lit, Loc))); | |
1644 | else | |
1645 | Rewrite (N, New_Occurrence_Of (Lit, Loc)); | |
1646 | end if; | |
1647 | ||
1648 | Resolve (N, Typ); | |
1649 | end if; | |
1650 | end if; | |
1651 | end Eval_Call; | |
1652 | ||
996ae0b0 RK |
1653 | ------------------------ |
1654 | -- Eval_Concatenation -- | |
1655 | ------------------------ | |
1656 | ||
3996951a TQ |
1657 | -- Concatenation is a static function, so the result is static if both |
1658 | -- operands are static (RM 4.9(7), 4.9(21)). | |
996ae0b0 RK |
1659 | |
1660 | procedure Eval_Concatenation (N : Node_Id) is | |
f91b40db GB |
1661 | Left : constant Node_Id := Left_Opnd (N); |
1662 | Right : constant Node_Id := Right_Opnd (N); | |
1663 | C_Typ : constant Entity_Id := Root_Type (Component_Type (Etype (N))); | |
996ae0b0 RK |
1664 | Stat : Boolean; |
1665 | Fold : Boolean; | |
996ae0b0 RK |
1666 | |
1667 | begin | |
3996951a TQ |
1668 | -- Concatenation is never static in Ada 83, so if Ada 83 check operand |
1669 | -- non-static context. | |
996ae0b0 | 1670 | |
0ab80019 | 1671 | if Ada_Version = Ada_83 |
996ae0b0 RK |
1672 | and then Comes_From_Source (N) |
1673 | then | |
1674 | Check_Non_Static_Context (Left); | |
1675 | Check_Non_Static_Context (Right); | |
1676 | return; | |
1677 | end if; | |
1678 | ||
1679 | -- If not foldable we are done. In principle concatenation that yields | |
1680 | -- any string type is static (i.e. an array type of character types). | |
1681 | -- However, character types can include enumeration literals, and | |
1682 | -- concatenation in that case cannot be described by a literal, so we | |
1683 | -- only consider the operation static if the result is an array of | |
1684 | -- (a descendant of) a predefined character type. | |
1685 | ||
1686 | Test_Expression_Is_Foldable (N, Left, Right, Stat, Fold); | |
1687 | ||
3996951a | 1688 | if not (Is_Standard_Character_Type (C_Typ) and then Fold) then |
996ae0b0 RK |
1689 | Set_Is_Static_Expression (N, False); |
1690 | return; | |
1691 | end if; | |
1692 | ||
82c80734 | 1693 | -- Compile time string concatenation |
996ae0b0 | 1694 | |
3996951a TQ |
1695 | -- ??? Note that operands that are aggregates can be marked as static, |
1696 | -- so we should attempt at a later stage to fold concatenations with | |
1697 | -- such aggregates. | |
996ae0b0 RK |
1698 | |
1699 | declare | |
b54ddf5a BD |
1700 | Left_Str : constant Node_Id := Get_String_Val (Left); |
1701 | Left_Len : Nat; | |
1702 | Right_Str : constant Node_Id := Get_String_Val (Right); | |
1703 | Folded_Val : String_Id; | |
996ae0b0 RK |
1704 | |
1705 | begin | |
1706 | -- Establish new string literal, and store left operand. We make | |
1707 | -- sure to use the special Start_String that takes an operand if | |
1708 | -- the left operand is a string literal. Since this is optimized | |
1709 | -- in the case where that is the most recently created string | |
1710 | -- literal, we ensure efficient time/space behavior for the | |
1711 | -- case of a concatenation of a series of string literals. | |
1712 | ||
1713 | if Nkind (Left_Str) = N_String_Literal then | |
f91b40db | 1714 | Left_Len := String_Length (Strval (Left_Str)); |
b54ddf5a BD |
1715 | |
1716 | -- If the left operand is the empty string, and the right operand | |
1717 | -- is a string literal (the case of "" & "..."), the result is the | |
1718 | -- value of the right operand. This optimization is important when | |
1719 | -- Is_Folded_In_Parser, to avoid copying an enormous right | |
1720 | -- operand. | |
1721 | ||
1722 | if Left_Len = 0 and then Nkind (Right_Str) = N_String_Literal then | |
1723 | Folded_Val := Strval (Right_Str); | |
1724 | else | |
1725 | Start_String (Strval (Left_Str)); | |
1726 | end if; | |
1727 | ||
996ae0b0 RK |
1728 | else |
1729 | Start_String; | |
82c80734 | 1730 | Store_String_Char (UI_To_CC (Char_Literal_Value (Left_Str))); |
f91b40db | 1731 | Left_Len := 1; |
996ae0b0 RK |
1732 | end if; |
1733 | ||
b54ddf5a BD |
1734 | -- Now append the characters of the right operand, unless we |
1735 | -- optimized the "" & "..." case above. | |
996ae0b0 RK |
1736 | |
1737 | if Nkind (Right_Str) = N_String_Literal then | |
b54ddf5a BD |
1738 | if Left_Len /= 0 then |
1739 | Store_String_Chars (Strval (Right_Str)); | |
1740 | Folded_Val := End_String; | |
1741 | end if; | |
996ae0b0 | 1742 | else |
82c80734 | 1743 | Store_String_Char (UI_To_CC (Char_Literal_Value (Right_Str))); |
b54ddf5a | 1744 | Folded_Val := End_String; |
996ae0b0 RK |
1745 | end if; |
1746 | ||
1747 | Set_Is_Static_Expression (N, Stat); | |
1748 | ||
1749 | if Stat then | |
f91b40db GB |
1750 | |
1751 | -- If left operand is the empty string, the result is the | |
1752 | -- right operand, including its bounds if anomalous. | |
1753 | ||
1754 | if Left_Len = 0 | |
1755 | and then Is_Array_Type (Etype (Right)) | |
1756 | and then Etype (Right) /= Any_String | |
1757 | then | |
1758 | Set_Etype (N, Etype (Right)); | |
1759 | end if; | |
1760 | ||
b54ddf5a | 1761 | Fold_Str (N, Folded_Val, Static => True); |
996ae0b0 RK |
1762 | end if; |
1763 | end; | |
1764 | end Eval_Concatenation; | |
1765 | ||
1766 | --------------------------------- | |
1767 | -- Eval_Conditional_Expression -- | |
1768 | --------------------------------- | |
1769 | ||
1770 | -- This GNAT internal construct can never be statically folded, so the | |
1771 | -- only required processing is to do the check for non-static context | |
1772 | -- for the two expression operands. | |
1773 | ||
1774 | procedure Eval_Conditional_Expression (N : Node_Id) is | |
1775 | Condition : constant Node_Id := First (Expressions (N)); | |
1776 | Then_Expr : constant Node_Id := Next (Condition); | |
1777 | Else_Expr : constant Node_Id := Next (Then_Expr); | |
1778 | ||
1779 | begin | |
1780 | Check_Non_Static_Context (Then_Expr); | |
1781 | Check_Non_Static_Context (Else_Expr); | |
1782 | end Eval_Conditional_Expression; | |
1783 | ||
1784 | ---------------------- | |
1785 | -- Eval_Entity_Name -- | |
1786 | ---------------------- | |
1787 | ||
1788 | -- This procedure is used for identifiers and expanded names other than | |
1789 | -- named numbers (see Eval_Named_Integer, Eval_Named_Real. These are | |
1790 | -- static if they denote a static constant (RM 4.9(6)) or if the name | |
1791 | -- denotes an enumeration literal (RM 4.9(22)). | |
1792 | ||
1793 | procedure Eval_Entity_Name (N : Node_Id) is | |
1794 | Def_Id : constant Entity_Id := Entity (N); | |
1795 | Val : Node_Id; | |
1796 | ||
1797 | begin | |
1798 | -- Enumeration literals are always considered to be constants | |
1799 | -- and cannot raise constraint error (RM 4.9(22)). | |
1800 | ||
1801 | if Ekind (Def_Id) = E_Enumeration_Literal then | |
1802 | Set_Is_Static_Expression (N); | |
1803 | return; | |
1804 | ||
1805 | -- A name is static if it denotes a static constant (RM 4.9(5)), and | |
1806 | -- we also copy Raise_Constraint_Error. Notice that even if non-static, | |
1807 | -- it does not violate 10.2.1(8) here, since this is not a variable. | |
1808 | ||
1809 | elsif Ekind (Def_Id) = E_Constant then | |
1810 | ||
1811 | -- Deferred constants must always be treated as nonstatic | |
1812 | -- outside the scope of their full view. | |
1813 | ||
1814 | if Present (Full_View (Def_Id)) | |
1815 | and then not In_Open_Scopes (Scope (Def_Id)) | |
1816 | then | |
1817 | Val := Empty; | |
1818 | else | |
1819 | Val := Constant_Value (Def_Id); | |
1820 | end if; | |
1821 | ||
1822 | if Present (Val) then | |
1823 | Set_Is_Static_Expression | |
1824 | (N, Is_Static_Expression (Val) | |
1825 | and then Is_Static_Subtype (Etype (Def_Id))); | |
1826 | Set_Raises_Constraint_Error (N, Raises_Constraint_Error (Val)); | |
1827 | ||
1828 | if not Is_Static_Expression (N) | |
1829 | and then not Is_Generic_Type (Etype (N)) | |
1830 | then | |
1831 | Validate_Static_Object_Name (N); | |
1832 | end if; | |
1833 | ||
1834 | return; | |
1835 | end if; | |
1836 | end if; | |
1837 | ||
82c80734 | 1838 | -- Fall through if the name is not static |
996ae0b0 RK |
1839 | |
1840 | Validate_Static_Object_Name (N); | |
1841 | end Eval_Entity_Name; | |
1842 | ||
1843 | ---------------------------- | |
1844 | -- Eval_Indexed_Component -- | |
1845 | ---------------------------- | |
1846 | ||
8cbb664e MG |
1847 | -- Indexed components are never static, so we need to perform the check |
1848 | -- for non-static context on the index values. Then, we check if the | |
1849 | -- value can be obtained at compile time, even though it is non-static. | |
996ae0b0 RK |
1850 | |
1851 | procedure Eval_Indexed_Component (N : Node_Id) is | |
1852 | Expr : Node_Id; | |
1853 | ||
1854 | begin | |
fbf5a39b AC |
1855 | -- Check for non-static context on index values |
1856 | ||
996ae0b0 RK |
1857 | Expr := First (Expressions (N)); |
1858 | while Present (Expr) loop | |
1859 | Check_Non_Static_Context (Expr); | |
1860 | Next (Expr); | |
1861 | end loop; | |
1862 | ||
fbf5a39b AC |
1863 | -- If the indexed component appears in an object renaming declaration |
1864 | -- then we do not want to try to evaluate it, since in this case we | |
1865 | -- need the identity of the array element. | |
1866 | ||
1867 | if Nkind (Parent (N)) = N_Object_Renaming_Declaration then | |
1868 | return; | |
1869 | ||
1870 | -- Similarly if the indexed component appears as the prefix of an | |
1871 | -- attribute we don't want to evaluate it, because at least for | |
1872 | -- some cases of attributes we need the identify (e.g. Access, Size) | |
1873 | ||
1874 | elsif Nkind (Parent (N)) = N_Attribute_Reference then | |
1875 | return; | |
1876 | end if; | |
1877 | ||
1878 | -- Note: there are other cases, such as the left side of an assignment, | |
1879 | -- or an OUT parameter for a call, where the replacement results in the | |
1880 | -- illegal use of a constant, But these cases are illegal in the first | |
1881 | -- place, so the replacement, though silly, is harmless. | |
1882 | ||
1883 | -- Now see if this is a constant array reference | |
8cbb664e MG |
1884 | |
1885 | if List_Length (Expressions (N)) = 1 | |
1886 | and then Is_Entity_Name (Prefix (N)) | |
1887 | and then Ekind (Entity (Prefix (N))) = E_Constant | |
1888 | and then Present (Constant_Value (Entity (Prefix (N)))) | |
1889 | then | |
1890 | declare | |
1891 | Loc : constant Source_Ptr := Sloc (N); | |
1892 | Arr : constant Node_Id := Constant_Value (Entity (Prefix (N))); | |
1893 | Sub : constant Node_Id := First (Expressions (N)); | |
1894 | ||
1895 | Atyp : Entity_Id; | |
1896 | -- Type of array | |
1897 | ||
1898 | Lin : Nat; | |
1899 | -- Linear one's origin subscript value for array reference | |
1900 | ||
1901 | Lbd : Node_Id; | |
1902 | -- Lower bound of the first array index | |
1903 | ||
1904 | Elm : Node_Id; | |
1905 | -- Value from constant array | |
1906 | ||
1907 | begin | |
1908 | Atyp := Etype (Arr); | |
1909 | ||
1910 | if Is_Access_Type (Atyp) then | |
1911 | Atyp := Designated_Type (Atyp); | |
1912 | end if; | |
1913 | ||
1914 | -- If we have an array type (we should have but perhaps there | |
1915 | -- are error cases where this is not the case), then see if we | |
1916 | -- can do a constant evaluation of the array reference. | |
1917 | ||
d610088d AC |
1918 | if Is_Array_Type (Atyp) |
1919 | and then Atyp /= Any_Composite | |
1920 | then | |
8cbb664e MG |
1921 | if Ekind (Atyp) = E_String_Literal_Subtype then |
1922 | Lbd := String_Literal_Low_Bound (Atyp); | |
1923 | else | |
1924 | Lbd := Type_Low_Bound (Etype (First_Index (Atyp))); | |
1925 | end if; | |
1926 | ||
1927 | if Compile_Time_Known_Value (Sub) | |
1928 | and then Nkind (Arr) = N_Aggregate | |
1929 | and then Compile_Time_Known_Value (Lbd) | |
1930 | and then Is_Discrete_Type (Component_Type (Atyp)) | |
1931 | then | |
1932 | Lin := UI_To_Int (Expr_Value (Sub) - Expr_Value (Lbd)) + 1; | |
1933 | ||
1934 | if List_Length (Expressions (Arr)) >= Lin then | |
1935 | Elm := Pick (Expressions (Arr), Lin); | |
1936 | ||
1937 | -- If the resulting expression is compile time known, | |
1938 | -- then we can rewrite the indexed component with this | |
1939 | -- value, being sure to mark the result as non-static. | |
1940 | -- We also reset the Sloc, in case this generates an | |
1941 | -- error later on (e.g. 136'Access). | |
1942 | ||
1943 | if Compile_Time_Known_Value (Elm) then | |
1944 | Rewrite (N, Duplicate_Subexpr_No_Checks (Elm)); | |
1945 | Set_Is_Static_Expression (N, False); | |
1946 | Set_Sloc (N, Loc); | |
1947 | end if; | |
1948 | end if; | |
9fbb3ae6 AC |
1949 | |
1950 | -- We can also constant-fold if the prefix is a string literal. | |
1951 | -- This will be useful in an instantiation or an inlining. | |
1952 | ||
1953 | elsif Compile_Time_Known_Value (Sub) | |
1954 | and then Nkind (Arr) = N_String_Literal | |
1955 | and then Compile_Time_Known_Value (Lbd) | |
1956 | and then Expr_Value (Lbd) = 1 | |
1957 | and then Expr_Value (Sub) <= | |
1958 | String_Literal_Length (Etype (Arr)) | |
1959 | then | |
1960 | declare | |
1961 | C : constant Char_Code := | |
1962 | Get_String_Char (Strval (Arr), | |
1963 | UI_To_Int (Expr_Value (Sub))); | |
1964 | begin | |
1965 | Set_Character_Literal_Name (C); | |
1966 | ||
1967 | Elm := | |
1968 | Make_Character_Literal (Loc, | |
1969 | Chars => Name_Find, | |
1970 | Char_Literal_Value => UI_From_CC (C)); | |
1971 | Set_Etype (Elm, Component_Type (Atyp)); | |
1972 | Rewrite (N, Duplicate_Subexpr_No_Checks (Elm)); | |
1973 | Set_Is_Static_Expression (N, False); | |
1974 | end; | |
8cbb664e MG |
1975 | end if; |
1976 | end if; | |
1977 | end; | |
1978 | end if; | |
996ae0b0 RK |
1979 | end Eval_Indexed_Component; |
1980 | ||
1981 | -------------------------- | |
1982 | -- Eval_Integer_Literal -- | |
1983 | -------------------------- | |
1984 | ||
1985 | -- Numeric literals are static (RM 4.9(1)), and have already been marked | |
1986 | -- as static by the analyzer. The reason we did it that early is to allow | |
1987 | -- the possibility of turning off the Is_Static_Expression flag after | |
1988 | -- analysis, but before resolution, when integer literals are generated | |
1989 | -- in the expander that do not correspond to static expressions. | |
1990 | ||
1991 | procedure Eval_Integer_Literal (N : Node_Id) is | |
1992 | T : constant Entity_Id := Etype (N); | |
1993 | ||
5d09245e | 1994 | function In_Any_Integer_Context return Boolean; |
1d1bd8ad AC |
1995 | -- If the literal is resolved with a specific type in a context where |
1996 | -- the expected type is Any_Integer, there are no range checks on the | |
1997 | -- literal. By the time the literal is evaluated, it carries the type | |
1998 | -- imposed by the enclosing expression, and we must recover the context | |
1999 | -- to determine that Any_Integer is meant. | |
5d09245e AC |
2000 | |
2001 | ---------------------------- | |
09494c32 | 2002 | -- In_Any_Integer_Context -- |
5d09245e AC |
2003 | ---------------------------- |
2004 | ||
2005 | function In_Any_Integer_Context return Boolean is | |
2006 | Par : constant Node_Id := Parent (N); | |
2007 | K : constant Node_Kind := Nkind (Par); | |
2008 | ||
2009 | begin | |
2010 | -- Any_Integer also appears in digits specifications for real types, | |
1d1bd8ad AC |
2011 | -- but those have bounds smaller that those of any integer base type, |
2012 | -- so we can safely ignore these cases. | |
5d09245e AC |
2013 | |
2014 | return K = N_Number_Declaration | |
2015 | or else K = N_Attribute_Reference | |
2016 | or else K = N_Attribute_Definition_Clause | |
2017 | or else K = N_Modular_Type_Definition | |
2018 | or else K = N_Signed_Integer_Type_Definition; | |
2019 | end In_Any_Integer_Context; | |
2020 | ||
2021 | -- Start of processing for Eval_Integer_Literal | |
2022 | ||
996ae0b0 | 2023 | begin |
5d09245e | 2024 | |
996ae0b0 | 2025 | -- If the literal appears in a non-expression context, then it is |
1d1bd8ad AC |
2026 | -- certainly appearing in a non-static context, so check it. This is |
2027 | -- actually a redundant check, since Check_Non_Static_Context would | |
2028 | -- check it, but it seems worth while avoiding the call. | |
996ae0b0 | 2029 | |
5d09245e AC |
2030 | if Nkind (Parent (N)) not in N_Subexpr |
2031 | and then not In_Any_Integer_Context | |
2032 | then | |
996ae0b0 RK |
2033 | Check_Non_Static_Context (N); |
2034 | end if; | |
2035 | ||
2036 | -- Modular integer literals must be in their base range | |
2037 | ||
2038 | if Is_Modular_Integer_Type (T) | |
c800f862 | 2039 | and then Is_Out_Of_Range (N, Base_Type (T), Assume_Valid => True) |
996ae0b0 RK |
2040 | then |
2041 | Out_Of_Range (N); | |
2042 | end if; | |
2043 | end Eval_Integer_Literal; | |
2044 | ||
2045 | --------------------- | |
2046 | -- Eval_Logical_Op -- | |
2047 | --------------------- | |
2048 | ||
2049 | -- Logical operations are static functions, so the result is potentially | |
2050 | -- static if both operands are potentially static (RM 4.9(7), 4.9(20)). | |
2051 | ||
2052 | procedure Eval_Logical_Op (N : Node_Id) is | |
2053 | Left : constant Node_Id := Left_Opnd (N); | |
2054 | Right : constant Node_Id := Right_Opnd (N); | |
2055 | Stat : Boolean; | |
2056 | Fold : Boolean; | |
2057 | ||
2058 | begin | |
2059 | -- If not foldable we are done | |
2060 | ||
2061 | Test_Expression_Is_Foldable (N, Left, Right, Stat, Fold); | |
2062 | ||
2063 | if not Fold then | |
2064 | return; | |
2065 | end if; | |
2066 | ||
2067 | -- Compile time evaluation of logical operation | |
2068 | ||
2069 | declare | |
2070 | Left_Int : constant Uint := Expr_Value (Left); | |
2071 | Right_Int : constant Uint := Expr_Value (Right); | |
2072 | ||
2073 | begin | |
2074 | if Is_Modular_Integer_Type (Etype (N)) then | |
2075 | declare | |
2076 | Left_Bits : Bits (0 .. UI_To_Int (Esize (Etype (N))) - 1); | |
2077 | Right_Bits : Bits (0 .. UI_To_Int (Esize (Etype (N))) - 1); | |
2078 | ||
2079 | begin | |
2080 | To_Bits (Left_Int, Left_Bits); | |
2081 | To_Bits (Right_Int, Right_Bits); | |
2082 | ||
2083 | -- Note: should really be able to use array ops instead of | |
2084 | -- these loops, but they weren't working at the time ??? | |
2085 | ||
2086 | if Nkind (N) = N_Op_And then | |
2087 | for J in Left_Bits'Range loop | |
2088 | Left_Bits (J) := Left_Bits (J) and Right_Bits (J); | |
2089 | end loop; | |
2090 | ||
2091 | elsif Nkind (N) = N_Op_Or then | |
2092 | for J in Left_Bits'Range loop | |
2093 | Left_Bits (J) := Left_Bits (J) or Right_Bits (J); | |
2094 | end loop; | |
2095 | ||
2096 | else | |
2097 | pragma Assert (Nkind (N) = N_Op_Xor); | |
2098 | ||
2099 | for J in Left_Bits'Range loop | |
2100 | Left_Bits (J) := Left_Bits (J) xor Right_Bits (J); | |
2101 | end loop; | |
2102 | end if; | |
2103 | ||
fbf5a39b | 2104 | Fold_Uint (N, From_Bits (Left_Bits, Etype (N)), Stat); |
996ae0b0 RK |
2105 | end; |
2106 | ||
2107 | else | |
2108 | pragma Assert (Is_Boolean_Type (Etype (N))); | |
2109 | ||
2110 | if Nkind (N) = N_Op_And then | |
2111 | Fold_Uint (N, | |
fbf5a39b | 2112 | Test (Is_True (Left_Int) and then Is_True (Right_Int)), Stat); |
996ae0b0 RK |
2113 | |
2114 | elsif Nkind (N) = N_Op_Or then | |
2115 | Fold_Uint (N, | |
fbf5a39b | 2116 | Test (Is_True (Left_Int) or else Is_True (Right_Int)), Stat); |
996ae0b0 RK |
2117 | |
2118 | else | |
2119 | pragma Assert (Nkind (N) = N_Op_Xor); | |
2120 | Fold_Uint (N, | |
fbf5a39b | 2121 | Test (Is_True (Left_Int) xor Is_True (Right_Int)), Stat); |
996ae0b0 RK |
2122 | end if; |
2123 | end if; | |
996ae0b0 RK |
2124 | end; |
2125 | end Eval_Logical_Op; | |
2126 | ||
2127 | ------------------------ | |
2128 | -- Eval_Membership_Op -- | |
2129 | ------------------------ | |
2130 | ||
1d1bd8ad AC |
2131 | -- A membership test is potentially static if the expression is static, and |
2132 | -- the range is a potentially static range, or is a subtype mark denoting a | |
2133 | -- static subtype (RM 4.9(12)). | |
996ae0b0 RK |
2134 | |
2135 | procedure Eval_Membership_Op (N : Node_Id) is | |
2136 | Left : constant Node_Id := Left_Opnd (N); | |
2137 | Right : constant Node_Id := Right_Opnd (N); | |
2138 | Def_Id : Entity_Id; | |
2139 | Lo : Node_Id; | |
2140 | Hi : Node_Id; | |
2141 | Result : Boolean; | |
2142 | Stat : Boolean; | |
2143 | Fold : Boolean; | |
2144 | ||
2145 | begin | |
1d1bd8ad AC |
2146 | -- Ignore if error in either operand, except to make sure that Any_Type |
2147 | -- is properly propagated to avoid junk cascaded errors. | |
996ae0b0 RK |
2148 | |
2149 | if Etype (Left) = Any_Type | |
2150 | or else Etype (Right) = Any_Type | |
2151 | then | |
2152 | Set_Etype (N, Any_Type); | |
2153 | return; | |
2154 | end if; | |
2155 | ||
2156 | -- Case of right operand is a subtype name | |
2157 | ||
2158 | if Is_Entity_Name (Right) then | |
2159 | Def_Id := Entity (Right); | |
2160 | ||
2161 | if (Is_Scalar_Type (Def_Id) or else Is_String_Type (Def_Id)) | |
2162 | and then Is_OK_Static_Subtype (Def_Id) | |
2163 | then | |
2164 | Test_Expression_Is_Foldable (N, Left, Stat, Fold); | |
2165 | ||
2166 | if not Fold or else not Stat then | |
2167 | return; | |
2168 | end if; | |
2169 | else | |
2170 | Check_Non_Static_Context (Left); | |
2171 | return; | |
2172 | end if; | |
2173 | ||
1d1bd8ad | 2174 | -- For string membership tests we will check the length further on |
996ae0b0 RK |
2175 | |
2176 | if not Is_String_Type (Def_Id) then | |
2177 | Lo := Type_Low_Bound (Def_Id); | |
2178 | Hi := Type_High_Bound (Def_Id); | |
2179 | ||
2180 | else | |
2181 | Lo := Empty; | |
2182 | Hi := Empty; | |
2183 | end if; | |
2184 | ||
2185 | -- Case of right operand is a range | |
2186 | ||
2187 | else | |
2188 | if Is_Static_Range (Right) then | |
2189 | Test_Expression_Is_Foldable (N, Left, Stat, Fold); | |
2190 | ||
2191 | if not Fold or else not Stat then | |
2192 | return; | |
2193 | ||
2194 | -- If one bound of range raises CE, then don't try to fold | |
2195 | ||
2196 | elsif not Is_OK_Static_Range (Right) then | |
2197 | Check_Non_Static_Context (Left); | |
2198 | return; | |
2199 | end if; | |
2200 | ||
2201 | else | |
2202 | Check_Non_Static_Context (Left); | |
2203 | return; | |
2204 | end if; | |
2205 | ||
2206 | -- Here we know range is an OK static range | |
2207 | ||
2208 | Lo := Low_Bound (Right); | |
2209 | Hi := High_Bound (Right); | |
2210 | end if; | |
2211 | ||
2212 | -- For strings we check that the length of the string expression is | |
2213 | -- compatible with the string subtype if the subtype is constrained, | |
2214 | -- or if unconstrained then the test is always true. | |
2215 | ||
2216 | if Is_String_Type (Etype (Right)) then | |
2217 | if not Is_Constrained (Etype (Right)) then | |
2218 | Result := True; | |
2219 | ||
2220 | else | |
2221 | declare | |
2222 | Typlen : constant Uint := String_Type_Len (Etype (Right)); | |
2223 | Strlen : constant Uint := | |
2224 | UI_From_Int (String_Length (Strval (Get_String_Val (Left)))); | |
2225 | begin | |
2226 | Result := (Typlen = Strlen); | |
2227 | end; | |
2228 | end if; | |
2229 | ||
1d1bd8ad AC |
2230 | -- Fold the membership test. We know we have a static range and Lo and |
2231 | -- Hi are set to the expressions for the end points of this range. | |
996ae0b0 RK |
2232 | |
2233 | elsif Is_Real_Type (Etype (Right)) then | |
2234 | declare | |
2235 | Leftval : constant Ureal := Expr_Value_R (Left); | |
2236 | ||
2237 | begin | |
2238 | Result := Expr_Value_R (Lo) <= Leftval | |
2239 | and then Leftval <= Expr_Value_R (Hi); | |
2240 | end; | |
2241 | ||
2242 | else | |
2243 | declare | |
2244 | Leftval : constant Uint := Expr_Value (Left); | |
2245 | ||
2246 | begin | |
2247 | Result := Expr_Value (Lo) <= Leftval | |
2248 | and then Leftval <= Expr_Value (Hi); | |
2249 | end; | |
2250 | end if; | |
2251 | ||
2252 | if Nkind (N) = N_Not_In then | |
2253 | Result := not Result; | |
2254 | end if; | |
2255 | ||
fbf5a39b | 2256 | Fold_Uint (N, Test (Result), True); |
996ae0b0 | 2257 | Warn_On_Known_Condition (N); |
996ae0b0 RK |
2258 | end Eval_Membership_Op; |
2259 | ||
2260 | ------------------------ | |
2261 | -- Eval_Named_Integer -- | |
2262 | ------------------------ | |
2263 | ||
2264 | procedure Eval_Named_Integer (N : Node_Id) is | |
2265 | begin | |
2266 | Fold_Uint (N, | |
fbf5a39b | 2267 | Expr_Value (Expression (Declaration_Node (Entity (N)))), True); |
996ae0b0 RK |
2268 | end Eval_Named_Integer; |
2269 | ||
2270 | --------------------- | |
2271 | -- Eval_Named_Real -- | |
2272 | --------------------- | |
2273 | ||
2274 | procedure Eval_Named_Real (N : Node_Id) is | |
2275 | begin | |
2276 | Fold_Ureal (N, | |
fbf5a39b | 2277 | Expr_Value_R (Expression (Declaration_Node (Entity (N)))), True); |
996ae0b0 RK |
2278 | end Eval_Named_Real; |
2279 | ||
2280 | ------------------- | |
2281 | -- Eval_Op_Expon -- | |
2282 | ------------------- | |
2283 | ||
2284 | -- Exponentiation is a static functions, so the result is potentially | |
2285 | -- static if both operands are potentially static (RM 4.9(7), 4.9(20)). | |
2286 | ||
2287 | procedure Eval_Op_Expon (N : Node_Id) is | |
2288 | Left : constant Node_Id := Left_Opnd (N); | |
2289 | Right : constant Node_Id := Right_Opnd (N); | |
2290 | Stat : Boolean; | |
2291 | Fold : Boolean; | |
2292 | ||
2293 | begin | |
2294 | -- If not foldable we are done | |
2295 | ||
2296 | Test_Expression_Is_Foldable (N, Left, Right, Stat, Fold); | |
2297 | ||
2298 | if not Fold then | |
2299 | return; | |
2300 | end if; | |
2301 | ||
2302 | -- Fold exponentiation operation | |
2303 | ||
2304 | declare | |
2305 | Right_Int : constant Uint := Expr_Value (Right); | |
2306 | ||
2307 | begin | |
2308 | -- Integer case | |
2309 | ||
2310 | if Is_Integer_Type (Etype (Left)) then | |
2311 | declare | |
2312 | Left_Int : constant Uint := Expr_Value (Left); | |
2313 | Result : Uint; | |
2314 | ||
2315 | begin | |
2316 | -- Exponentiation of an integer raises the exception | |
2317 | -- Constraint_Error for a negative exponent (RM 4.5.6) | |
2318 | ||
2319 | if Right_Int < 0 then | |
2320 | Apply_Compile_Time_Constraint_Error | |
fbf5a39b AC |
2321 | (N, "integer exponent negative", |
2322 | CE_Range_Check_Failed, | |
2323 | Warn => not Stat); | |
996ae0b0 RK |
2324 | return; |
2325 | ||
2326 | else | |
2327 | if OK_Bits (N, Num_Bits (Left_Int) * Right_Int) then | |
2328 | Result := Left_Int ** Right_Int; | |
2329 | else | |
2330 | Result := Left_Int; | |
2331 | end if; | |
2332 | ||
2333 | if Is_Modular_Integer_Type (Etype (N)) then | |
2334 | Result := Result mod Modulus (Etype (N)); | |
2335 | end if; | |
2336 | ||
fbf5a39b | 2337 | Fold_Uint (N, Result, Stat); |
996ae0b0 RK |
2338 | end if; |
2339 | end; | |
2340 | ||
2341 | -- Real case | |
2342 | ||
2343 | else | |
2344 | declare | |
2345 | Left_Real : constant Ureal := Expr_Value_R (Left); | |
2346 | ||
2347 | begin | |
2348 | -- Cannot have a zero base with a negative exponent | |
2349 | ||
2350 | if UR_Is_Zero (Left_Real) then | |
2351 | ||
2352 | if Right_Int < 0 then | |
2353 | Apply_Compile_Time_Constraint_Error | |
fbf5a39b AC |
2354 | (N, "zero ** negative integer", |
2355 | CE_Range_Check_Failed, | |
2356 | Warn => not Stat); | |
996ae0b0 RK |
2357 | return; |
2358 | else | |
fbf5a39b | 2359 | Fold_Ureal (N, Ureal_0, Stat); |
996ae0b0 RK |
2360 | end if; |
2361 | ||
2362 | else | |
fbf5a39b | 2363 | Fold_Ureal (N, Left_Real ** Right_Int, Stat); |
996ae0b0 RK |
2364 | end if; |
2365 | end; | |
2366 | end if; | |
996ae0b0 RK |
2367 | end; |
2368 | end Eval_Op_Expon; | |
2369 | ||
2370 | ----------------- | |
2371 | -- Eval_Op_Not -- | |
2372 | ----------------- | |
2373 | ||
2374 | -- The not operation is a static functions, so the result is potentially | |
2375 | -- static if the operand is potentially static (RM 4.9(7), 4.9(20)). | |
2376 | ||
2377 | procedure Eval_Op_Not (N : Node_Id) is | |
2378 | Right : constant Node_Id := Right_Opnd (N); | |
2379 | Stat : Boolean; | |
2380 | Fold : Boolean; | |
2381 | ||
2382 | begin | |
2383 | -- If not foldable we are done | |
2384 | ||
2385 | Test_Expression_Is_Foldable (N, Right, Stat, Fold); | |
2386 | ||
2387 | if not Fold then | |
2388 | return; | |
2389 | end if; | |
2390 | ||
2391 | -- Fold not operation | |
2392 | ||
2393 | declare | |
2394 | Rint : constant Uint := Expr_Value (Right); | |
2395 | Typ : constant Entity_Id := Etype (N); | |
2396 | ||
2397 | begin | |
1d1bd8ad AC |
2398 | -- Negation is equivalent to subtracting from the modulus minus one. |
2399 | -- For a binary modulus this is equivalent to the ones-complement of | |
2400 | -- the original value. For non-binary modulus this is an arbitrary | |
2401 | -- but consistent definition. | |
996ae0b0 RK |
2402 | |
2403 | if Is_Modular_Integer_Type (Typ) then | |
fbf5a39b | 2404 | Fold_Uint (N, Modulus (Typ) - 1 - Rint, Stat); |
996ae0b0 RK |
2405 | |
2406 | else | |
2407 | pragma Assert (Is_Boolean_Type (Typ)); | |
fbf5a39b | 2408 | Fold_Uint (N, Test (not Is_True (Rint)), Stat); |
996ae0b0 RK |
2409 | end if; |
2410 | ||
2411 | Set_Is_Static_Expression (N, Stat); | |
2412 | end; | |
2413 | end Eval_Op_Not; | |
2414 | ||
2415 | ------------------------------- | |
2416 | -- Eval_Qualified_Expression -- | |
2417 | ------------------------------- | |
2418 | ||
2419 | -- A qualified expression is potentially static if its subtype mark denotes | |
2420 | -- a static subtype and its expression is potentially static (RM 4.9 (11)). | |
2421 | ||
2422 | procedure Eval_Qualified_Expression (N : Node_Id) is | |
2423 | Operand : constant Node_Id := Expression (N); | |
2424 | Target_Type : constant Entity_Id := Entity (Subtype_Mark (N)); | |
2425 | ||
07fc65c4 GB |
2426 | Stat : Boolean; |
2427 | Fold : Boolean; | |
2428 | Hex : Boolean; | |
996ae0b0 RK |
2429 | |
2430 | begin | |
1d1bd8ad | 2431 | -- Can only fold if target is string or scalar and subtype is static. |
996ae0b0 RK |
2432 | -- Also, do not fold if our parent is an allocator (this is because |
2433 | -- the qualified expression is really part of the syntactic structure | |
2434 | -- of an allocator, and we do not want to end up with something that | |
2435 | -- corresponds to "new 1" where the 1 is the result of folding a | |
2436 | -- qualified expression). | |
2437 | ||
2438 | if not Is_Static_Subtype (Target_Type) | |
2439 | or else Nkind (Parent (N)) = N_Allocator | |
2440 | then | |
2441 | Check_Non_Static_Context (Operand); | |
af152989 | 2442 | |
1d1bd8ad AC |
2443 | -- If operand is known to raise constraint_error, set the flag on the |
2444 | -- expression so it does not get optimized away. | |
af152989 AC |
2445 | |
2446 | if Nkind (Operand) = N_Raise_Constraint_Error then | |
2447 | Set_Raises_Constraint_Error (N); | |
2448 | end if; | |
7324bf49 | 2449 | |
996ae0b0 RK |
2450 | return; |
2451 | end if; | |
2452 | ||
2453 | -- If not foldable we are done | |
2454 | ||
2455 | Test_Expression_Is_Foldable (N, Operand, Stat, Fold); | |
2456 | ||
2457 | if not Fold then | |
2458 | return; | |
2459 | ||
2460 | -- Don't try fold if target type has constraint error bounds | |
2461 | ||
2462 | elsif not Is_OK_Static_Subtype (Target_Type) then | |
2463 | Set_Raises_Constraint_Error (N); | |
2464 | return; | |
2465 | end if; | |
2466 | ||
07fc65c4 GB |
2467 | -- Here we will fold, save Print_In_Hex indication |
2468 | ||
2469 | Hex := Nkind (Operand) = N_Integer_Literal | |
2470 | and then Print_In_Hex (Operand); | |
2471 | ||
996ae0b0 RK |
2472 | -- Fold the result of qualification |
2473 | ||
2474 | if Is_Discrete_Type (Target_Type) then | |
fbf5a39b | 2475 | Fold_Uint (N, Expr_Value (Operand), Stat); |
996ae0b0 | 2476 | |
07fc65c4 GB |
2477 | -- Preserve Print_In_Hex indication |
2478 | ||
2479 | if Hex and then Nkind (N) = N_Integer_Literal then | |
2480 | Set_Print_In_Hex (N); | |
2481 | end if; | |
2482 | ||
996ae0b0 | 2483 | elsif Is_Real_Type (Target_Type) then |
fbf5a39b | 2484 | Fold_Ureal (N, Expr_Value_R (Operand), Stat); |
996ae0b0 RK |
2485 | |
2486 | else | |
fbf5a39b | 2487 | Fold_Str (N, Strval (Get_String_Val (Operand)), Stat); |
996ae0b0 RK |
2488 | |
2489 | if not Stat then | |
2490 | Set_Is_Static_Expression (N, False); | |
2491 | else | |
2492 | Check_String_Literal_Length (N, Target_Type); | |
2493 | end if; | |
2494 | ||
2495 | return; | |
2496 | end if; | |
2497 | ||
fbf5a39b AC |
2498 | -- The expression may be foldable but not static |
2499 | ||
2500 | Set_Is_Static_Expression (N, Stat); | |
2501 | ||
c800f862 | 2502 | if Is_Out_Of_Range (N, Etype (N), Assume_Valid => True) then |
996ae0b0 RK |
2503 | Out_Of_Range (N); |
2504 | end if; | |
996ae0b0 RK |
2505 | end Eval_Qualified_Expression; |
2506 | ||
2507 | ----------------------- | |
2508 | -- Eval_Real_Literal -- | |
2509 | ----------------------- | |
2510 | ||
2511 | -- Numeric literals are static (RM 4.9(1)), and have already been marked | |
2512 | -- as static by the analyzer. The reason we did it that early is to allow | |
2513 | -- the possibility of turning off the Is_Static_Expression flag after | |
2514 | -- analysis, but before resolution, when integer literals are generated | |
2515 | -- in the expander that do not correspond to static expressions. | |
2516 | ||
2517 | procedure Eval_Real_Literal (N : Node_Id) is | |
a1980be8 GB |
2518 | PK : constant Node_Kind := Nkind (Parent (N)); |
2519 | ||
996ae0b0 | 2520 | begin |
1d1bd8ad AC |
2521 | -- If the literal appears in a non-expression context and not as part of |
2522 | -- a number declaration, then it is appearing in a non-static context, | |
2523 | -- so check it. | |
996ae0b0 | 2524 | |
a1980be8 | 2525 | if PK not in N_Subexpr and then PK /= N_Number_Declaration then |
996ae0b0 RK |
2526 | Check_Non_Static_Context (N); |
2527 | end if; | |
996ae0b0 RK |
2528 | end Eval_Real_Literal; |
2529 | ||
2530 | ------------------------ | |
2531 | -- Eval_Relational_Op -- | |
2532 | ------------------------ | |
2533 | ||
2534 | -- Relational operations are static functions, so the result is static | |
93c3fca7 AC |
2535 | -- if both operands are static (RM 4.9(7), 4.9(20)), except that for |
2536 | -- strings, the result is never static, even if the operands are. | |
996ae0b0 RK |
2537 | |
2538 | procedure Eval_Relational_Op (N : Node_Id) is | |
2539 | Left : constant Node_Id := Left_Opnd (N); | |
2540 | Right : constant Node_Id := Right_Opnd (N); | |
2541 | Typ : constant Entity_Id := Etype (Left); | |
2542 | Result : Boolean; | |
2543 | Stat : Boolean; | |
2544 | Fold : Boolean; | |
2545 | ||
2546 | begin | |
45fc7ddb HK |
2547 | -- One special case to deal with first. If we can tell that the result |
2548 | -- will be false because the lengths of one or more index subtypes are | |
2549 | -- compile time known and different, then we can replace the entire | |
2550 | -- result by False. We only do this for one dimensional arrays, because | |
2551 | -- the case of multi-dimensional arrays is rare and too much trouble! If | |
2552 | -- one of the operands is an illegal aggregate, its type might still be | |
2553 | -- an arbitrary composite type, so nothing to do. | |
996ae0b0 RK |
2554 | |
2555 | if Is_Array_Type (Typ) | |
13f34a3f | 2556 | and then Typ /= Any_Composite |
996ae0b0 | 2557 | and then Number_Dimensions (Typ) = 1 |
13f34a3f | 2558 | and then (Nkind (N) = N_Op_Eq or else Nkind (N) = N_Op_Ne) |
996ae0b0 RK |
2559 | then |
2560 | if Raises_Constraint_Error (Left) | |
2561 | or else Raises_Constraint_Error (Right) | |
2562 | then | |
2563 | return; | |
2564 | end if; | |
2565 | ||
45fc7ddb HK |
2566 | -- OK, we have the case where we may be able to do this fold |
2567 | ||
2568 | Length_Mismatch : declare | |
996ae0b0 | 2569 | procedure Get_Static_Length (Op : Node_Id; Len : out Uint); |
1d1bd8ad AC |
2570 | -- If Op is an expression for a constrained array with a known at |
2571 | -- compile time length, then Len is set to this (non-negative | |
13f34a3f | 2572 | -- length). Otherwise Len is set to minus 1. |
996ae0b0 | 2573 | |
fbf5a39b AC |
2574 | ----------------------- |
2575 | -- Get_Static_Length -- | |
2576 | ----------------------- | |
2577 | ||
996ae0b0 RK |
2578 | procedure Get_Static_Length (Op : Node_Id; Len : out Uint) is |
2579 | T : Entity_Id; | |
2580 | ||
2581 | begin | |
45fc7ddb HK |
2582 | -- First easy case string literal |
2583 | ||
996ae0b0 RK |
2584 | if Nkind (Op) = N_String_Literal then |
2585 | Len := UI_From_Int (String_Length (Strval (Op))); | |
45fc7ddb HK |
2586 | return; |
2587 | end if; | |
2588 | ||
2589 | -- Second easy case, not constrained subtype, so no length | |
996ae0b0 | 2590 | |
45fc7ddb | 2591 | if not Is_Constrained (Etype (Op)) then |
996ae0b0 | 2592 | Len := Uint_Minus_1; |
45fc7ddb HK |
2593 | return; |
2594 | end if; | |
996ae0b0 | 2595 | |
45fc7ddb HK |
2596 | -- General case |
2597 | ||
2598 | T := Etype (First_Index (Etype (Op))); | |
2599 | ||
2600 | -- The simple case, both bounds are known at compile time | |
2601 | ||
2602 | if Is_Discrete_Type (T) | |
2603 | and then | |
2604 | Compile_Time_Known_Value (Type_Low_Bound (T)) | |
2605 | and then | |
2606 | Compile_Time_Known_Value (Type_High_Bound (T)) | |
2607 | then | |
2608 | Len := UI_Max (Uint_0, | |
2609 | Expr_Value (Type_High_Bound (T)) - | |
2610 | Expr_Value (Type_Low_Bound (T)) + 1); | |
2611 | return; | |
2612 | end if; | |
2613 | ||
2614 | -- A more complex case, where the bounds are of the form | |
2615 | -- X [+/- K1] .. X [+/- K2]), where X is an expression that is | |
2616 | -- either A'First or A'Last (with A an entity name), or X is an | |
2617 | -- entity name, and the two X's are the same and K1 and K2 are | |
2618 | -- known at compile time, in this case, the length can also be | |
2619 | -- computed at compile time, even though the bounds are not | |
2620 | -- known. A common case of this is e.g. (X'First..X'First+5). | |
2621 | ||
2622 | Extract_Length : declare | |
2623 | procedure Decompose_Expr | |
2624 | (Expr : Node_Id; | |
2625 | Ent : out Entity_Id; | |
2626 | Kind : out Character; | |
2627 | Cons : out Uint); | |
2628 | -- Given an expression, see if is of the form above, | |
2629 | -- X [+/- K]. If so Ent is set to the entity in X, | |
2630 | -- Kind is 'F','L','E' for 'First/'Last/simple entity, | |
2631 | -- and Cons is the value of K. If the expression is | |
2632 | -- not of the required form, Ent is set to Empty. | |
2633 | ||
2634 | -------------------- | |
2635 | -- Decompose_Expr -- | |
2636 | -------------------- | |
2637 | ||
2638 | procedure Decompose_Expr | |
2639 | (Expr : Node_Id; | |
2640 | Ent : out Entity_Id; | |
2641 | Kind : out Character; | |
2642 | Cons : out Uint) | |
2643 | is | |
2644 | Exp : Node_Id; | |
2645 | ||
2646 | begin | |
2647 | if Nkind (Expr) = N_Op_Add | |
2648 | and then Compile_Time_Known_Value (Right_Opnd (Expr)) | |
2649 | then | |
2650 | Exp := Left_Opnd (Expr); | |
2651 | Cons := Expr_Value (Right_Opnd (Expr)); | |
2652 | ||
2653 | elsif Nkind (Expr) = N_Op_Subtract | |
2654 | and then Compile_Time_Known_Value (Right_Opnd (Expr)) | |
2655 | then | |
2656 | Exp := Left_Opnd (Expr); | |
2657 | Cons := -Expr_Value (Right_Opnd (Expr)); | |
996ae0b0 | 2658 | |
45fc7ddb HK |
2659 | else |
2660 | Exp := Expr; | |
2661 | Cons := Uint_0; | |
2662 | end if; | |
2663 | ||
2664 | -- At this stage Exp is set to the potential X | |
2665 | ||
2666 | if Nkind (Exp) = N_Attribute_Reference then | |
2667 | if Attribute_Name (Exp) = Name_First then | |
2668 | Kind := 'F'; | |
2669 | elsif Attribute_Name (Exp) = Name_Last then | |
2670 | Kind := 'L'; | |
2671 | else | |
2672 | Ent := Empty; | |
2673 | return; | |
2674 | end if; | |
2675 | ||
2676 | Exp := Prefix (Exp); | |
2677 | ||
2678 | else | |
2679 | Kind := 'E'; | |
2680 | end if; | |
2681 | ||
2682 | if Is_Entity_Name (Exp) | |
2683 | and then Present (Entity (Exp)) | |
2684 | then | |
2685 | Ent := Entity (Exp); | |
2686 | else | |
2687 | Ent := Empty; | |
2688 | end if; | |
2689 | end Decompose_Expr; | |
2690 | ||
2691 | -- Local Variables | |
2692 | ||
2693 | Ent1, Ent2 : Entity_Id; | |
2694 | Kind1, Kind2 : Character; | |
2695 | Cons1, Cons2 : Uint; | |
2696 | ||
2697 | -- Start of processing for Extract_Length | |
2698 | ||
2699 | begin | |
bafc9e1d AC |
2700 | Decompose_Expr |
2701 | (Original_Node (Type_Low_Bound (T)), Ent1, Kind1, Cons1); | |
2702 | Decompose_Expr | |
2703 | (Original_Node (Type_High_Bound (T)), Ent2, Kind2, Cons2); | |
45fc7ddb HK |
2704 | |
2705 | if Present (Ent1) | |
2706 | and then Kind1 = Kind2 | |
2707 | and then Ent1 = Ent2 | |
996ae0b0 | 2708 | then |
45fc7ddb | 2709 | Len := Cons2 - Cons1 + 1; |
996ae0b0 RK |
2710 | else |
2711 | Len := Uint_Minus_1; | |
2712 | end if; | |
45fc7ddb | 2713 | end Extract_Length; |
996ae0b0 RK |
2714 | end Get_Static_Length; |
2715 | ||
45fc7ddb HK |
2716 | -- Local Variables |
2717 | ||
996ae0b0 RK |
2718 | Len_L : Uint; |
2719 | Len_R : Uint; | |
2720 | ||
45fc7ddb HK |
2721 | -- Start of processing for Length_Mismatch |
2722 | ||
996ae0b0 RK |
2723 | begin |
2724 | Get_Static_Length (Left, Len_L); | |
2725 | Get_Static_Length (Right, Len_R); | |
2726 | ||
2727 | if Len_L /= Uint_Minus_1 | |
2728 | and then Len_R /= Uint_Minus_1 | |
2729 | and then Len_L /= Len_R | |
2730 | then | |
fbf5a39b | 2731 | Fold_Uint (N, Test (Nkind (N) = N_Op_Ne), False); |
996ae0b0 RK |
2732 | Warn_On_Known_Condition (N); |
2733 | return; | |
2734 | end if; | |
45fc7ddb HK |
2735 | end Length_Mismatch; |
2736 | end if; | |
6eaf4095 | 2737 | |
93c3fca7 | 2738 | -- Test for expression being foldable |
7a3f77d2 | 2739 | |
93c3fca7 | 2740 | Test_Expression_Is_Foldable (N, Left, Right, Stat, Fold); |
996ae0b0 | 2741 | |
93c3fca7 AC |
2742 | -- Only comparisons of scalars can give static results. In particular, |
2743 | -- comparisons of strings never yield a static result, even if both | |
2744 | -- operands are static strings. | |
996ae0b0 RK |
2745 | |
2746 | if not Is_Scalar_Type (Typ) then | |
93c3fca7 AC |
2747 | Stat := False; |
2748 | Set_Is_Static_Expression (N, False); | |
996ae0b0 RK |
2749 | end if; |
2750 | ||
93c3fca7 AC |
2751 | -- For static real type expressions, we cannot use Compile_Time_Compare |
2752 | -- since it worries about run-time results which are not exact. | |
996ae0b0 | 2753 | |
93c3fca7 | 2754 | if Stat and then Is_Real_Type (Typ) then |
996ae0b0 | 2755 | declare |
93c3fca7 AC |
2756 | Left_Real : constant Ureal := Expr_Value_R (Left); |
2757 | Right_Real : constant Ureal := Expr_Value_R (Right); | |
996ae0b0 RK |
2758 | |
2759 | begin | |
2760 | case Nkind (N) is | |
93c3fca7 AC |
2761 | when N_Op_Eq => Result := (Left_Real = Right_Real); |
2762 | when N_Op_Ne => Result := (Left_Real /= Right_Real); | |
2763 | when N_Op_Lt => Result := (Left_Real < Right_Real); | |
2764 | when N_Op_Le => Result := (Left_Real <= Right_Real); | |
2765 | when N_Op_Gt => Result := (Left_Real > Right_Real); | |
2766 | when N_Op_Ge => Result := (Left_Real >= Right_Real); | |
996ae0b0 RK |
2767 | |
2768 | when others => | |
2769 | raise Program_Error; | |
2770 | end case; | |
2771 | ||
93c3fca7 | 2772 | Fold_Uint (N, Test (Result), True); |
996ae0b0 RK |
2773 | end; |
2774 | ||
93c3fca7 | 2775 | -- For all other cases, we use Compile_Time_Compare to do the compare |
996ae0b0 RK |
2776 | |
2777 | else | |
996ae0b0 | 2778 | declare |
93c3fca7 AC |
2779 | CR : constant Compare_Result := |
2780 | Compile_Time_Compare (Left, Right, Assume_Valid => False); | |
996ae0b0 RK |
2781 | |
2782 | begin | |
93c3fca7 AC |
2783 | if CR = Unknown then |
2784 | return; | |
2785 | end if; | |
2786 | ||
996ae0b0 | 2787 | case Nkind (N) is |
93c3fca7 AC |
2788 | when N_Op_Eq => |
2789 | if CR = EQ then | |
2790 | Result := True; | |
2791 | elsif CR = NE or else CR = GT or else CR = LT then | |
2792 | Result := False; | |
2793 | else | |
2794 | return; | |
2795 | end if; | |
2796 | ||
2797 | when N_Op_Ne => | |
2798 | if CR = NE or else CR = GT or else CR = LT then | |
2799 | Result := True; | |
2800 | elsif CR = EQ then | |
2801 | Result := False; | |
2802 | else | |
2803 | return; | |
2804 | end if; | |
2805 | ||
2806 | when N_Op_Lt => | |
2807 | if CR = LT then | |
2808 | Result := True; | |
2809 | elsif CR = EQ or else CR = GT or else CR = GE then | |
2810 | Result := False; | |
2811 | else | |
2812 | return; | |
2813 | end if; | |
2814 | ||
2815 | when N_Op_Le => | |
2816 | if CR = LT or else CR = EQ or else CR = LE then | |
2817 | Result := True; | |
2818 | elsif CR = GT then | |
2819 | Result := False; | |
2820 | else | |
2821 | return; | |
2822 | end if; | |
2823 | ||
2824 | when N_Op_Gt => | |
2825 | if CR = GT then | |
2826 | Result := True; | |
2827 | elsif CR = EQ or else CR = LT or else CR = LE then | |
2828 | Result := False; | |
2829 | else | |
2830 | return; | |
2831 | end if; | |
2832 | ||
2833 | when N_Op_Ge => | |
2834 | if CR = GT or else CR = EQ or else CR = GE then | |
2835 | Result := True; | |
2836 | elsif CR = LT then | |
2837 | Result := False; | |
2838 | else | |
2839 | return; | |
2840 | end if; | |
996ae0b0 RK |
2841 | |
2842 | when others => | |
2843 | raise Program_Error; | |
2844 | end case; | |
996ae0b0 | 2845 | end; |
93c3fca7 AC |
2846 | |
2847 | Fold_Uint (N, Test (Result), Stat); | |
996ae0b0 RK |
2848 | end if; |
2849 | ||
996ae0b0 RK |
2850 | Warn_On_Known_Condition (N); |
2851 | end Eval_Relational_Op; | |
2852 | ||
2853 | ---------------- | |
2854 | -- Eval_Shift -- | |
2855 | ---------------- | |
2856 | ||
2857 | -- Shift operations are intrinsic operations that can never be static, | |
2858 | -- so the only processing required is to perform the required check for | |
2859 | -- a non static context for the two operands. | |
2860 | ||
2861 | -- Actually we could do some compile time evaluation here some time ??? | |
2862 | ||
2863 | procedure Eval_Shift (N : Node_Id) is | |
2864 | begin | |
2865 | Check_Non_Static_Context (Left_Opnd (N)); | |
2866 | Check_Non_Static_Context (Right_Opnd (N)); | |
2867 | end Eval_Shift; | |
2868 | ||
2869 | ------------------------ | |
2870 | -- Eval_Short_Circuit -- | |
2871 | ------------------------ | |
2872 | ||
2873 | -- A short circuit operation is potentially static if both operands | |
2874 | -- are potentially static (RM 4.9 (13)) | |
2875 | ||
2876 | procedure Eval_Short_Circuit (N : Node_Id) is | |
2877 | Kind : constant Node_Kind := Nkind (N); | |
2878 | Left : constant Node_Id := Left_Opnd (N); | |
2879 | Right : constant Node_Id := Right_Opnd (N); | |
2880 | Left_Int : Uint; | |
2881 | Rstat : constant Boolean := | |
2882 | Is_Static_Expression (Left) | |
2883 | and then Is_Static_Expression (Right); | |
2884 | ||
2885 | begin | |
2886 | -- Short circuit operations are never static in Ada 83 | |
2887 | ||
0ab80019 | 2888 | if Ada_Version = Ada_83 |
996ae0b0 RK |
2889 | and then Comes_From_Source (N) |
2890 | then | |
2891 | Check_Non_Static_Context (Left); | |
2892 | Check_Non_Static_Context (Right); | |
2893 | return; | |
2894 | end if; | |
2895 | ||
2896 | -- Now look at the operands, we can't quite use the normal call to | |
2897 | -- Test_Expression_Is_Foldable here because short circuit operations | |
2898 | -- are a special case, they can still be foldable, even if the right | |
2899 | -- operand raises constraint error. | |
2900 | ||
2901 | -- If either operand is Any_Type, just propagate to result and | |
2902 | -- do not try to fold, this prevents cascaded errors. | |
2903 | ||
2904 | if Etype (Left) = Any_Type or else Etype (Right) = Any_Type then | |
2905 | Set_Etype (N, Any_Type); | |
2906 | return; | |
2907 | ||
2908 | -- If left operand raises constraint error, then replace node N with | |
2909 | -- the raise constraint error node, and we are obviously not foldable. | |
2910 | -- Is_Static_Expression is set from the two operands in the normal way, | |
2911 | -- and we check the right operand if it is in a non-static context. | |
2912 | ||
2913 | elsif Raises_Constraint_Error (Left) then | |
2914 | if not Rstat then | |
2915 | Check_Non_Static_Context (Right); | |
2916 | end if; | |
2917 | ||
2918 | Rewrite_In_Raise_CE (N, Left); | |
2919 | Set_Is_Static_Expression (N, Rstat); | |
2920 | return; | |
2921 | ||
2922 | -- If the result is not static, then we won't in any case fold | |
2923 | ||
2924 | elsif not Rstat then | |
2925 | Check_Non_Static_Context (Left); | |
2926 | Check_Non_Static_Context (Right); | |
2927 | return; | |
2928 | end if; | |
2929 | ||
2930 | -- Here the result is static, note that, unlike the normal processing | |
2931 | -- in Test_Expression_Is_Foldable, we did *not* check above to see if | |
2932 | -- the right operand raises constraint error, that's because it is not | |
2933 | -- significant if the left operand is decisive. | |
2934 | ||
2935 | Set_Is_Static_Expression (N); | |
2936 | ||
2937 | -- It does not matter if the right operand raises constraint error if | |
2938 | -- it will not be evaluated. So deal specially with the cases where | |
2939 | -- the right operand is not evaluated. Note that we will fold these | |
2940 | -- cases even if the right operand is non-static, which is fine, but | |
2941 | -- of course in these cases the result is not potentially static. | |
2942 | ||
2943 | Left_Int := Expr_Value (Left); | |
2944 | ||
2945 | if (Kind = N_And_Then and then Is_False (Left_Int)) | |
514d0fc5 AC |
2946 | or else |
2947 | (Kind = N_Or_Else and then Is_True (Left_Int)) | |
996ae0b0 | 2948 | then |
fbf5a39b | 2949 | Fold_Uint (N, Left_Int, Rstat); |
996ae0b0 RK |
2950 | return; |
2951 | end if; | |
2952 | ||
2953 | -- If first operand not decisive, then it does matter if the right | |
2954 | -- operand raises constraint error, since it will be evaluated, so | |
2955 | -- we simply replace the node with the right operand. Note that this | |
2956 | -- properly propagates Is_Static_Expression and Raises_Constraint_Error | |
2957 | -- (both are set to True in Right). | |
2958 | ||
2959 | if Raises_Constraint_Error (Right) then | |
2960 | Rewrite_In_Raise_CE (N, Right); | |
2961 | Check_Non_Static_Context (Left); | |
2962 | return; | |
2963 | end if; | |
2964 | ||
2965 | -- Otherwise the result depends on the right operand | |
2966 | ||
fbf5a39b | 2967 | Fold_Uint (N, Expr_Value (Right), Rstat); |
996ae0b0 | 2968 | return; |
996ae0b0 RK |
2969 | end Eval_Short_Circuit; |
2970 | ||
2971 | ---------------- | |
2972 | -- Eval_Slice -- | |
2973 | ---------------- | |
2974 | ||
2975 | -- Slices can never be static, so the only processing required is to | |
2976 | -- check for non-static context if an explicit range is given. | |
2977 | ||
2978 | procedure Eval_Slice (N : Node_Id) is | |
2979 | Drange : constant Node_Id := Discrete_Range (N); | |
996ae0b0 RK |
2980 | begin |
2981 | if Nkind (Drange) = N_Range then | |
2982 | Check_Non_Static_Context (Low_Bound (Drange)); | |
2983 | Check_Non_Static_Context (High_Bound (Drange)); | |
2984 | end if; | |
cd2fb920 ES |
2985 | |
2986 | -- A slice of the form A (subtype), when the subtype is the index of | |
2987 | -- the type of A, is redundant, the slice can be replaced with A, and | |
2988 | -- this is worth a warning. | |
2989 | ||
2990 | if Is_Entity_Name (Prefix (N)) then | |
2991 | declare | |
2992 | E : constant Entity_Id := Entity (Prefix (N)); | |
2993 | T : constant Entity_Id := Etype (E); | |
2994 | begin | |
2995 | if Ekind (E) = E_Constant | |
2996 | and then Is_Array_Type (T) | |
2997 | and then Is_Entity_Name (Drange) | |
2998 | then | |
2999 | if Is_Entity_Name (Original_Node (First_Index (T))) | |
3000 | and then Entity (Original_Node (First_Index (T))) | |
3001 | = Entity (Drange) | |
3002 | then | |
3003 | if Warn_On_Redundant_Constructs then | |
3004 | Error_Msg_N ("redundant slice denotes whole array?", N); | |
3005 | end if; | |
3006 | ||
3007 | -- The following might be a useful optimization ???? | |
3008 | ||
3009 | -- Rewrite (N, New_Occurrence_Of (E, Sloc (N))); | |
3010 | end if; | |
3011 | end if; | |
3012 | end; | |
3013 | end if; | |
996ae0b0 RK |
3014 | end Eval_Slice; |
3015 | ||
3016 | ------------------------- | |
3017 | -- Eval_String_Literal -- | |
3018 | ------------------------- | |
3019 | ||
3020 | procedure Eval_String_Literal (N : Node_Id) is | |
91b1417d AC |
3021 | Typ : constant Entity_Id := Etype (N); |
3022 | Bas : constant Entity_Id := Base_Type (Typ); | |
3023 | Xtp : Entity_Id; | |
3024 | Len : Nat; | |
3025 | Lo : Node_Id; | |
996ae0b0 RK |
3026 | |
3027 | begin | |
3028 | -- Nothing to do if error type (handles cases like default expressions | |
3029 | -- or generics where we have not yet fully resolved the type) | |
3030 | ||
91b1417d | 3031 | if Bas = Any_Type or else Bas = Any_String then |
996ae0b0 | 3032 | return; |
91b1417d | 3033 | end if; |
996ae0b0 RK |
3034 | |
3035 | -- String literals are static if the subtype is static (RM 4.9(2)), so | |
3036 | -- reset the static expression flag (it was set unconditionally in | |
3037 | -- Analyze_String_Literal) if the subtype is non-static. We tell if | |
3038 | -- the subtype is static by looking at the lower bound. | |
3039 | ||
91b1417d AC |
3040 | if Ekind (Typ) = E_String_Literal_Subtype then |
3041 | if not Is_OK_Static_Expression (String_Literal_Low_Bound (Typ)) then | |
3042 | Set_Is_Static_Expression (N, False); | |
3043 | return; | |
3044 | end if; | |
3045 | ||
3046 | -- Here if Etype of string literal is normal Etype (not yet possible, | |
3047 | -- but may be possible in future!) | |
3048 | ||
3049 | elsif not Is_OK_Static_Expression | |
3050 | (Type_Low_Bound (Etype (First_Index (Typ)))) | |
3051 | then | |
996ae0b0 | 3052 | Set_Is_Static_Expression (N, False); |
91b1417d AC |
3053 | return; |
3054 | end if; | |
996ae0b0 | 3055 | |
91b1417d AC |
3056 | -- If original node was a type conversion, then result if non-static |
3057 | ||
3058 | if Nkind (Original_Node (N)) = N_Type_Conversion then | |
996ae0b0 | 3059 | Set_Is_Static_Expression (N, False); |
91b1417d AC |
3060 | return; |
3061 | end if; | |
996ae0b0 RK |
3062 | |
3063 | -- Test for illegal Ada 95 cases. A string literal is illegal in | |
3064 | -- Ada 95 if its bounds are outside the index base type and this | |
91b1417d | 3065 | -- index type is static. This can happen in only two ways. Either |
996ae0b0 RK |
3066 | -- the string literal is too long, or it is null, and the lower |
3067 | -- bound is type'First. In either case it is the upper bound that | |
3068 | -- is out of range of the index type. | |
3069 | ||
0ab80019 | 3070 | if Ada_Version >= Ada_95 then |
91b1417d AC |
3071 | if Root_Type (Bas) = Standard_String |
3072 | or else | |
3073 | Root_Type (Bas) = Standard_Wide_String | |
996ae0b0 | 3074 | then |
91b1417d | 3075 | Xtp := Standard_Positive; |
996ae0b0 | 3076 | else |
91b1417d | 3077 | Xtp := Etype (First_Index (Bas)); |
996ae0b0 RK |
3078 | end if; |
3079 | ||
91b1417d AC |
3080 | if Ekind (Typ) = E_String_Literal_Subtype then |
3081 | Lo := String_Literal_Low_Bound (Typ); | |
3082 | else | |
3083 | Lo := Type_Low_Bound (Etype (First_Index (Typ))); | |
3084 | end if; | |
3085 | ||
3086 | Len := String_Length (Strval (N)); | |
3087 | ||
3088 | if UI_From_Int (Len) > String_Type_Len (Bas) then | |
996ae0b0 | 3089 | Apply_Compile_Time_Constraint_Error |
07fc65c4 | 3090 | (N, "string literal too long for}", CE_Length_Check_Failed, |
91b1417d AC |
3091 | Ent => Bas, |
3092 | Typ => First_Subtype (Bas)); | |
996ae0b0 | 3093 | |
91b1417d AC |
3094 | elsif Len = 0 |
3095 | and then not Is_Generic_Type (Xtp) | |
3096 | and then | |
3097 | Expr_Value (Lo) = Expr_Value (Type_Low_Bound (Base_Type (Xtp))) | |
996ae0b0 RK |
3098 | then |
3099 | Apply_Compile_Time_Constraint_Error | |
3100 | (N, "null string literal not allowed for}", | |
07fc65c4 | 3101 | CE_Length_Check_Failed, |
91b1417d AC |
3102 | Ent => Bas, |
3103 | Typ => First_Subtype (Bas)); | |
996ae0b0 RK |
3104 | end if; |
3105 | end if; | |
996ae0b0 RK |
3106 | end Eval_String_Literal; |
3107 | ||
3108 | -------------------------- | |
3109 | -- Eval_Type_Conversion -- | |
3110 | -------------------------- | |
3111 | ||
3112 | -- A type conversion is potentially static if its subtype mark is for a | |
3113 | -- static scalar subtype, and its operand expression is potentially static | |
3114 | -- (RM 4.9 (10)) | |
3115 | ||
3116 | procedure Eval_Type_Conversion (N : Node_Id) is | |
3117 | Operand : constant Node_Id := Expression (N); | |
3118 | Source_Type : constant Entity_Id := Etype (Operand); | |
3119 | Target_Type : constant Entity_Id := Etype (N); | |
3120 | ||
3121 | Stat : Boolean; | |
3122 | Fold : Boolean; | |
3123 | ||
3124 | function To_Be_Treated_As_Integer (T : Entity_Id) return Boolean; | |
3125 | -- Returns true if type T is an integer type, or if it is a | |
3126 | -- fixed-point type to be treated as an integer (i.e. the flag | |
3127 | -- Conversion_OK is set on the conversion node). | |
3128 | ||
3129 | function To_Be_Treated_As_Real (T : Entity_Id) return Boolean; | |
3130 | -- Returns true if type T is a floating-point type, or if it is a | |
3131 | -- fixed-point type that is not to be treated as an integer (i.e. the | |
3132 | -- flag Conversion_OK is not set on the conversion node). | |
3133 | ||
fbf5a39b AC |
3134 | ------------------------------ |
3135 | -- To_Be_Treated_As_Integer -- | |
3136 | ------------------------------ | |
3137 | ||
996ae0b0 RK |
3138 | function To_Be_Treated_As_Integer (T : Entity_Id) return Boolean is |
3139 | begin | |
3140 | return | |
3141 | Is_Integer_Type (T) | |
3142 | or else (Is_Fixed_Point_Type (T) and then Conversion_OK (N)); | |
3143 | end To_Be_Treated_As_Integer; | |
3144 | ||
fbf5a39b AC |
3145 | --------------------------- |
3146 | -- To_Be_Treated_As_Real -- | |
3147 | --------------------------- | |
3148 | ||
996ae0b0 RK |
3149 | function To_Be_Treated_As_Real (T : Entity_Id) return Boolean is |
3150 | begin | |
3151 | return | |
3152 | Is_Floating_Point_Type (T) | |
3153 | or else (Is_Fixed_Point_Type (T) and then not Conversion_OK (N)); | |
3154 | end To_Be_Treated_As_Real; | |
3155 | ||
3156 | -- Start of processing for Eval_Type_Conversion | |
3157 | ||
3158 | begin | |
82c80734 | 3159 | -- Cannot fold if target type is non-static or if semantic error |
996ae0b0 RK |
3160 | |
3161 | if not Is_Static_Subtype (Target_Type) then | |
3162 | Check_Non_Static_Context (Operand); | |
3163 | return; | |
3164 | ||
3165 | elsif Error_Posted (N) then | |
3166 | return; | |
3167 | end if; | |
3168 | ||
3169 | -- If not foldable we are done | |
3170 | ||
3171 | Test_Expression_Is_Foldable (N, Operand, Stat, Fold); | |
3172 | ||
3173 | if not Fold then | |
3174 | return; | |
3175 | ||
3176 | -- Don't try fold if target type has constraint error bounds | |
3177 | ||
3178 | elsif not Is_OK_Static_Subtype (Target_Type) then | |
3179 | Set_Raises_Constraint_Error (N); | |
3180 | return; | |
3181 | end if; | |
3182 | ||
3183 | -- Remaining processing depends on operand types. Note that in the | |
3184 | -- following type test, fixed-point counts as real unless the flag | |
3185 | -- Conversion_OK is set, in which case it counts as integer. | |
3186 | ||
82c80734 | 3187 | -- Fold conversion, case of string type. The result is not static |
996ae0b0 RK |
3188 | |
3189 | if Is_String_Type (Target_Type) then | |
b11e8d6f | 3190 | Fold_Str (N, Strval (Get_String_Val (Operand)), Static => False); |
996ae0b0 RK |
3191 | |
3192 | return; | |
3193 | ||
3194 | -- Fold conversion, case of integer target type | |
3195 | ||
3196 | elsif To_Be_Treated_As_Integer (Target_Type) then | |
3197 | declare | |
3198 | Result : Uint; | |
3199 | ||
3200 | begin | |
3201 | -- Integer to integer conversion | |
3202 | ||
3203 | if To_Be_Treated_As_Integer (Source_Type) then | |
3204 | Result := Expr_Value (Operand); | |
3205 | ||
3206 | -- Real to integer conversion | |
3207 | ||
3208 | else | |
3209 | Result := UR_To_Uint (Expr_Value_R (Operand)); | |
3210 | end if; | |
3211 | ||
3212 | -- If fixed-point type (Conversion_OK must be set), then the | |
3213 | -- result is logically an integer, but we must replace the | |
3214 | -- conversion with the corresponding real literal, since the | |
3215 | -- type from a semantic point of view is still fixed-point. | |
3216 | ||
3217 | if Is_Fixed_Point_Type (Target_Type) then | |
3218 | Fold_Ureal | |
fbf5a39b | 3219 | (N, UR_From_Uint (Result) * Small_Value (Target_Type), Stat); |
996ae0b0 RK |
3220 | |
3221 | -- Otherwise result is integer literal | |
3222 | ||
3223 | else | |
fbf5a39b | 3224 | Fold_Uint (N, Result, Stat); |
996ae0b0 RK |
3225 | end if; |
3226 | end; | |
3227 | ||
3228 | -- Fold conversion, case of real target type | |
3229 | ||
3230 | elsif To_Be_Treated_As_Real (Target_Type) then | |
3231 | declare | |
3232 | Result : Ureal; | |
3233 | ||
3234 | begin | |
3235 | if To_Be_Treated_As_Real (Source_Type) then | |
3236 | Result := Expr_Value_R (Operand); | |
3237 | else | |
3238 | Result := UR_From_Uint (Expr_Value (Operand)); | |
3239 | end if; | |
3240 | ||
fbf5a39b | 3241 | Fold_Ureal (N, Result, Stat); |
996ae0b0 RK |
3242 | end; |
3243 | ||
3244 | -- Enumeration types | |
3245 | ||
3246 | else | |
fbf5a39b | 3247 | Fold_Uint (N, Expr_Value (Operand), Stat); |
996ae0b0 RK |
3248 | end if; |
3249 | ||
c800f862 | 3250 | if Is_Out_Of_Range (N, Etype (N), Assume_Valid => True) then |
996ae0b0 RK |
3251 | Out_Of_Range (N); |
3252 | end if; | |
3253 | ||
3254 | end Eval_Type_Conversion; | |
3255 | ||
3256 | ------------------- | |
3257 | -- Eval_Unary_Op -- | |
3258 | ------------------- | |
3259 | ||
3260 | -- Predefined unary operators are static functions (RM 4.9(20)) and thus | |
3261 | -- are potentially static if the operand is potentially static (RM 4.9(7)) | |
3262 | ||
3263 | procedure Eval_Unary_Op (N : Node_Id) is | |
3264 | Right : constant Node_Id := Right_Opnd (N); | |
3265 | Stat : Boolean; | |
3266 | Fold : Boolean; | |
3267 | ||
3268 | begin | |
3269 | -- If not foldable we are done | |
3270 | ||
3271 | Test_Expression_Is_Foldable (N, Right, Stat, Fold); | |
3272 | ||
3273 | if not Fold then | |
3274 | return; | |
3275 | end if; | |
3276 | ||
3277 | -- Fold for integer case | |
3278 | ||
3279 | if Is_Integer_Type (Etype (N)) then | |
3280 | declare | |
3281 | Rint : constant Uint := Expr_Value (Right); | |
3282 | Result : Uint; | |
3283 | ||
3284 | begin | |
3285 | -- In the case of modular unary plus and abs there is no need | |
3286 | -- to adjust the result of the operation since if the original | |
3287 | -- operand was in bounds the result will be in the bounds of the | |
3288 | -- modular type. However, in the case of modular unary minus the | |
3289 | -- result may go out of the bounds of the modular type and needs | |
3290 | -- adjustment. | |
3291 | ||
3292 | if Nkind (N) = N_Op_Plus then | |
3293 | Result := Rint; | |
3294 | ||
3295 | elsif Nkind (N) = N_Op_Minus then | |
3296 | if Is_Modular_Integer_Type (Etype (N)) then | |
3297 | Result := (-Rint) mod Modulus (Etype (N)); | |
3298 | else | |
3299 | Result := (-Rint); | |
3300 | end if; | |
3301 | ||
3302 | else | |
3303 | pragma Assert (Nkind (N) = N_Op_Abs); | |
3304 | Result := abs Rint; | |
3305 | end if; | |
3306 | ||
fbf5a39b | 3307 | Fold_Uint (N, Result, Stat); |
996ae0b0 RK |
3308 | end; |
3309 | ||
3310 | -- Fold for real case | |
3311 | ||
3312 | elsif Is_Real_Type (Etype (N)) then | |
3313 | declare | |
3314 | Rreal : constant Ureal := Expr_Value_R (Right); | |
3315 | Result : Ureal; | |
3316 | ||
3317 | begin | |
3318 | if Nkind (N) = N_Op_Plus then | |
3319 | Result := Rreal; | |
3320 | ||
3321 | elsif Nkind (N) = N_Op_Minus then | |
3322 | Result := UR_Negate (Rreal); | |
3323 | ||
3324 | else | |
3325 | pragma Assert (Nkind (N) = N_Op_Abs); | |
3326 | Result := abs Rreal; | |
3327 | end if; | |
3328 | ||
fbf5a39b | 3329 | Fold_Ureal (N, Result, Stat); |
996ae0b0 RK |
3330 | end; |
3331 | end if; | |
996ae0b0 RK |
3332 | end Eval_Unary_Op; |
3333 | ||
3334 | ------------------------------- | |
3335 | -- Eval_Unchecked_Conversion -- | |
3336 | ------------------------------- | |
3337 | ||
3338 | -- Unchecked conversions can never be static, so the only required | |
3339 | -- processing is to check for a non-static context for the operand. | |
3340 | ||
3341 | procedure Eval_Unchecked_Conversion (N : Node_Id) is | |
3342 | begin | |
3343 | Check_Non_Static_Context (Expression (N)); | |
3344 | end Eval_Unchecked_Conversion; | |
3345 | ||
3346 | -------------------- | |
3347 | -- Expr_Rep_Value -- | |
3348 | -------------------- | |
3349 | ||
3350 | function Expr_Rep_Value (N : Node_Id) return Uint is | |
07fc65c4 GB |
3351 | Kind : constant Node_Kind := Nkind (N); |
3352 | Ent : Entity_Id; | |
996ae0b0 RK |
3353 | |
3354 | begin | |
3355 | if Is_Entity_Name (N) then | |
3356 | Ent := Entity (N); | |
3357 | ||
3358 | -- An enumeration literal that was either in the source or | |
3359 | -- created as a result of static evaluation. | |
3360 | ||
3361 | if Ekind (Ent) = E_Enumeration_Literal then | |
3362 | return Enumeration_Rep (Ent); | |
3363 | ||
3364 | -- A user defined static constant | |
3365 | ||
3366 | else | |
3367 | pragma Assert (Ekind (Ent) = E_Constant); | |
3368 | return Expr_Rep_Value (Constant_Value (Ent)); | |
3369 | end if; | |
3370 | ||
3371 | -- An integer literal that was either in the source or created | |
3372 | -- as a result of static evaluation. | |
3373 | ||
3374 | elsif Kind = N_Integer_Literal then | |
3375 | return Intval (N); | |
3376 | ||
3377 | -- A real literal for a fixed-point type. This must be the fixed-point | |
3378 | -- case, either the literal is of a fixed-point type, or it is a bound | |
3379 | -- of a fixed-point type, with type universal real. In either case we | |
3380 | -- obtain the desired value from Corresponding_Integer_Value. | |
3381 | ||
3382 | elsif Kind = N_Real_Literal then | |
996ae0b0 RK |
3383 | pragma Assert (Is_Fixed_Point_Type (Underlying_Type (Etype (N)))); |
3384 | return Corresponding_Integer_Value (N); | |
3385 | ||
07fc65c4 GB |
3386 | -- Peculiar VMS case, if we have xxx'Null_Parameter, return zero |
3387 | ||
3388 | elsif Kind = N_Attribute_Reference | |
3389 | and then Attribute_Name (N) = Name_Null_Parameter | |
3390 | then | |
3391 | return Uint_0; | |
3392 | ||
07fc65c4 | 3393 | -- Otherwise must be character literal |
8cbb664e | 3394 | |
996ae0b0 RK |
3395 | else |
3396 | pragma Assert (Kind = N_Character_Literal); | |
3397 | Ent := Entity (N); | |
3398 | ||
3399 | -- Since Character literals of type Standard.Character don't | |
3400 | -- have any defining character literals built for them, they | |
3401 | -- do not have their Entity set, so just use their Char | |
3402 | -- code. Otherwise for user-defined character literals use | |
3403 | -- their Pos value as usual which is the same as the Rep value. | |
3404 | ||
3405 | if No (Ent) then | |
82c80734 | 3406 | return Char_Literal_Value (N); |
996ae0b0 RK |
3407 | else |
3408 | return Enumeration_Rep (Ent); | |
3409 | end if; | |
3410 | end if; | |
3411 | end Expr_Rep_Value; | |
3412 | ||
3413 | ---------------- | |
3414 | -- Expr_Value -- | |
3415 | ---------------- | |
3416 | ||
3417 | function Expr_Value (N : Node_Id) return Uint is | |
07fc65c4 GB |
3418 | Kind : constant Node_Kind := Nkind (N); |
3419 | CV_Ent : CV_Entry renames CV_Cache (Nat (N) mod CV_Cache_Size); | |
3420 | Ent : Entity_Id; | |
3421 | Val : Uint; | |
996ae0b0 RK |
3422 | |
3423 | begin | |
13f34a3f RD |
3424 | -- If already in cache, then we know it's compile time known and we can |
3425 | -- return the value that was previously stored in the cache since | |
3426 | -- compile time known values cannot change. | |
07fc65c4 GB |
3427 | |
3428 | if CV_Ent.N = N then | |
3429 | return CV_Ent.V; | |
3430 | end if; | |
3431 | ||
3432 | -- Otherwise proceed to test value | |
3433 | ||
996ae0b0 RK |
3434 | if Is_Entity_Name (N) then |
3435 | Ent := Entity (N); | |
3436 | ||
3437 | -- An enumeration literal that was either in the source or | |
3438 | -- created as a result of static evaluation. | |
3439 | ||
3440 | if Ekind (Ent) = E_Enumeration_Literal then | |
07fc65c4 | 3441 | Val := Enumeration_Pos (Ent); |
996ae0b0 RK |
3442 | |
3443 | -- A user defined static constant | |
3444 | ||
3445 | else | |
3446 | pragma Assert (Ekind (Ent) = E_Constant); | |
07fc65c4 | 3447 | Val := Expr_Value (Constant_Value (Ent)); |
996ae0b0 RK |
3448 | end if; |
3449 | ||
3450 | -- An integer literal that was either in the source or created | |
3451 | -- as a result of static evaluation. | |
3452 | ||
3453 | elsif Kind = N_Integer_Literal then | |
07fc65c4 | 3454 | Val := Intval (N); |
996ae0b0 RK |
3455 | |
3456 | -- A real literal for a fixed-point type. This must be the fixed-point | |
3457 | -- case, either the literal is of a fixed-point type, or it is a bound | |
3458 | -- of a fixed-point type, with type universal real. In either case we | |
3459 | -- obtain the desired value from Corresponding_Integer_Value. | |
3460 | ||
3461 | elsif Kind = N_Real_Literal then | |
3462 | ||
996ae0b0 | 3463 | pragma Assert (Is_Fixed_Point_Type (Underlying_Type (Etype (N)))); |
07fc65c4 | 3464 | Val := Corresponding_Integer_Value (N); |
996ae0b0 RK |
3465 | |
3466 | -- Peculiar VMS case, if we have xxx'Null_Parameter, return zero | |
3467 | ||
3468 | elsif Kind = N_Attribute_Reference | |
3469 | and then Attribute_Name (N) = Name_Null_Parameter | |
3470 | then | |
07fc65c4 GB |
3471 | Val := Uint_0; |
3472 | ||
996ae0b0 RK |
3473 | -- Otherwise must be character literal |
3474 | ||
3475 | else | |
3476 | pragma Assert (Kind = N_Character_Literal); | |
3477 | Ent := Entity (N); | |
3478 | ||
3479 | -- Since Character literals of type Standard.Character don't | |
3480 | -- have any defining character literals built for them, they | |
3481 | -- do not have their Entity set, so just use their Char | |
3482 | -- code. Otherwise for user-defined character literals use | |
3483 | -- their Pos value as usual. | |
3484 | ||
3485 | if No (Ent) then | |
82c80734 | 3486 | Val := Char_Literal_Value (N); |
996ae0b0 | 3487 | else |
07fc65c4 | 3488 | Val := Enumeration_Pos (Ent); |
996ae0b0 RK |
3489 | end if; |
3490 | end if; | |
3491 | ||
07fc65c4 GB |
3492 | -- Come here with Val set to value to be returned, set cache |
3493 | ||
3494 | CV_Ent.N := N; | |
3495 | CV_Ent.V := Val; | |
3496 | return Val; | |
996ae0b0 RK |
3497 | end Expr_Value; |
3498 | ||
3499 | ------------------ | |
3500 | -- Expr_Value_E -- | |
3501 | ------------------ | |
3502 | ||
3503 | function Expr_Value_E (N : Node_Id) return Entity_Id is | |
3504 | Ent : constant Entity_Id := Entity (N); | |
3505 | ||
3506 | begin | |
3507 | if Ekind (Ent) = E_Enumeration_Literal then | |
3508 | return Ent; | |
3509 | else | |
3510 | pragma Assert (Ekind (Ent) = E_Constant); | |
3511 | return Expr_Value_E (Constant_Value (Ent)); | |
3512 | end if; | |
3513 | end Expr_Value_E; | |
3514 | ||
3515 | ------------------ | |
3516 | -- Expr_Value_R -- | |
3517 | ------------------ | |
3518 | ||
3519 | function Expr_Value_R (N : Node_Id) return Ureal is | |
3520 | Kind : constant Node_Kind := Nkind (N); | |
3521 | Ent : Entity_Id; | |
3522 | Expr : Node_Id; | |
3523 | ||
3524 | begin | |
3525 | if Kind = N_Real_Literal then | |
3526 | return Realval (N); | |
3527 | ||
3528 | elsif Kind = N_Identifier or else Kind = N_Expanded_Name then | |
3529 | Ent := Entity (N); | |
3530 | pragma Assert (Ekind (Ent) = E_Constant); | |
3531 | return Expr_Value_R (Constant_Value (Ent)); | |
3532 | ||
3533 | elsif Kind = N_Integer_Literal then | |
3534 | return UR_From_Uint (Expr_Value (N)); | |
3535 | ||
3536 | -- Strange case of VAX literals, which are at this stage transformed | |
3537 | -- into Vax_Type!x_To_y(IEEE_Literal). See Expand_N_Real_Literal in | |
3538 | -- Exp_Vfpt for further details. | |
3539 | ||
3540 | elsif Vax_Float (Etype (N)) | |
3541 | and then Nkind (N) = N_Unchecked_Type_Conversion | |
3542 | then | |
3543 | Expr := Expression (N); | |
3544 | ||
3545 | if Nkind (Expr) = N_Function_Call | |
3546 | and then Present (Parameter_Associations (Expr)) | |
3547 | then | |
3548 | Expr := First (Parameter_Associations (Expr)); | |
3549 | ||
3550 | if Nkind (Expr) = N_Real_Literal then | |
3551 | return Realval (Expr); | |
3552 | end if; | |
3553 | end if; | |
3554 | ||
3555 | -- Peculiar VMS case, if we have xxx'Null_Parameter, return 0.0 | |
3556 | ||
3557 | elsif Kind = N_Attribute_Reference | |
3558 | and then Attribute_Name (N) = Name_Null_Parameter | |
3559 | then | |
3560 | return Ureal_0; | |
3561 | end if; | |
3562 | ||
f3d57416 | 3563 | -- If we fall through, we have a node that cannot be interpreted |
996ae0b0 RK |
3564 | -- as a compile time constant. That is definitely an error. |
3565 | ||
3566 | raise Program_Error; | |
3567 | end Expr_Value_R; | |
3568 | ||
3569 | ------------------ | |
3570 | -- Expr_Value_S -- | |
3571 | ------------------ | |
3572 | ||
3573 | function Expr_Value_S (N : Node_Id) return Node_Id is | |
3574 | begin | |
3575 | if Nkind (N) = N_String_Literal then | |
3576 | return N; | |
3577 | else | |
3578 | pragma Assert (Ekind (Entity (N)) = E_Constant); | |
3579 | return Expr_Value_S (Constant_Value (Entity (N))); | |
3580 | end if; | |
3581 | end Expr_Value_S; | |
3582 | ||
fbf5a39b AC |
3583 | -------------------------- |
3584 | -- Flag_Non_Static_Expr -- | |
3585 | -------------------------- | |
3586 | ||
3587 | procedure Flag_Non_Static_Expr (Msg : String; Expr : Node_Id) is | |
3588 | begin | |
3589 | if Error_Posted (Expr) and then not All_Errors_Mode then | |
3590 | return; | |
3591 | else | |
3592 | Error_Msg_F (Msg, Expr); | |
3593 | Why_Not_Static (Expr); | |
3594 | end if; | |
3595 | end Flag_Non_Static_Expr; | |
3596 | ||
996ae0b0 RK |
3597 | -------------- |
3598 | -- Fold_Str -- | |
3599 | -------------- | |
3600 | ||
fbf5a39b | 3601 | procedure Fold_Str (N : Node_Id; Val : String_Id; Static : Boolean) is |
996ae0b0 RK |
3602 | Loc : constant Source_Ptr := Sloc (N); |
3603 | Typ : constant Entity_Id := Etype (N); | |
3604 | ||
3605 | begin | |
3606 | Rewrite (N, Make_String_Literal (Loc, Strval => Val)); | |
fbf5a39b AC |
3607 | |
3608 | -- We now have the literal with the right value, both the actual type | |
3609 | -- and the expected type of this literal are taken from the expression | |
3610 | -- that was evaluated. | |
3611 | ||
3612 | Analyze (N); | |
3613 | Set_Is_Static_Expression (N, Static); | |
3614 | Set_Etype (N, Typ); | |
3615 | Resolve (N); | |
996ae0b0 RK |
3616 | end Fold_Str; |
3617 | ||
3618 | --------------- | |
3619 | -- Fold_Uint -- | |
3620 | --------------- | |
3621 | ||
fbf5a39b | 3622 | procedure Fold_Uint (N : Node_Id; Val : Uint; Static : Boolean) is |
996ae0b0 | 3623 | Loc : constant Source_Ptr := Sloc (N); |
fbf5a39b AC |
3624 | Typ : Entity_Id := Etype (N); |
3625 | Ent : Entity_Id; | |
996ae0b0 RK |
3626 | |
3627 | begin | |
fbf5a39b AC |
3628 | -- If we are folding a named number, retain the entity in the |
3629 | -- literal, for ASIS use. | |
3630 | ||
3631 | if Is_Entity_Name (N) | |
3632 | and then Ekind (Entity (N)) = E_Named_Integer | |
3633 | then | |
3634 | Ent := Entity (N); | |
3635 | else | |
3636 | Ent := Empty; | |
3637 | end if; | |
3638 | ||
3639 | if Is_Private_Type (Typ) then | |
3640 | Typ := Full_View (Typ); | |
3641 | end if; | |
3642 | ||
f3d57416 | 3643 | -- For a result of type integer, substitute an N_Integer_Literal node |
996ae0b0 | 3644 | -- for the result of the compile time evaluation of the expression. |
cd2fb920 ES |
3645 | -- For ASIS use, set a link to the original named number when not in |
3646 | -- a generic context. | |
996ae0b0 | 3647 | |
fbf5a39b | 3648 | if Is_Integer_Type (Typ) then |
996ae0b0 | 3649 | Rewrite (N, Make_Integer_Literal (Loc, Val)); |
cd2fb920 | 3650 | |
fbf5a39b | 3651 | Set_Original_Entity (N, Ent); |
996ae0b0 RK |
3652 | |
3653 | -- Otherwise we have an enumeration type, and we substitute either | |
3654 | -- an N_Identifier or N_Character_Literal to represent the enumeration | |
3655 | -- literal corresponding to the given value, which must always be in | |
3656 | -- range, because appropriate tests have already been made for this. | |
3657 | ||
fbf5a39b | 3658 | else pragma Assert (Is_Enumeration_Type (Typ)); |
996ae0b0 RK |
3659 | Rewrite (N, Get_Enum_Lit_From_Pos (Etype (N), Val, Loc)); |
3660 | end if; | |
3661 | ||
3662 | -- We now have the literal with the right value, both the actual type | |
3663 | -- and the expected type of this literal are taken from the expression | |
3664 | -- that was evaluated. | |
3665 | ||
3666 | Analyze (N); | |
fbf5a39b | 3667 | Set_Is_Static_Expression (N, Static); |
996ae0b0 | 3668 | Set_Etype (N, Typ); |
fbf5a39b | 3669 | Resolve (N); |
996ae0b0 RK |
3670 | end Fold_Uint; |
3671 | ||
3672 | ---------------- | |
3673 | -- Fold_Ureal -- | |
3674 | ---------------- | |
3675 | ||
fbf5a39b | 3676 | procedure Fold_Ureal (N : Node_Id; Val : Ureal; Static : Boolean) is |
996ae0b0 RK |
3677 | Loc : constant Source_Ptr := Sloc (N); |
3678 | Typ : constant Entity_Id := Etype (N); | |
fbf5a39b | 3679 | Ent : Entity_Id; |
996ae0b0 RK |
3680 | |
3681 | begin | |
fbf5a39b AC |
3682 | -- If we are folding a named number, retain the entity in the |
3683 | -- literal, for ASIS use. | |
3684 | ||
3685 | if Is_Entity_Name (N) | |
3686 | and then Ekind (Entity (N)) = E_Named_Real | |
3687 | then | |
3688 | Ent := Entity (N); | |
3689 | else | |
3690 | Ent := Empty; | |
3691 | end if; | |
3692 | ||
996ae0b0 | 3693 | Rewrite (N, Make_Real_Literal (Loc, Realval => Val)); |
cd2fb920 | 3694 | |
5a30024a | 3695 | -- Set link to original named number, for ASIS use |
cd2fb920 | 3696 | |
fbf5a39b | 3697 | Set_Original_Entity (N, Ent); |
996ae0b0 RK |
3698 | |
3699 | -- Both the actual and expected type comes from the original expression | |
3700 | ||
fbf5a39b AC |
3701 | Analyze (N); |
3702 | Set_Is_Static_Expression (N, Static); | |
996ae0b0 | 3703 | Set_Etype (N, Typ); |
fbf5a39b | 3704 | Resolve (N); |
996ae0b0 RK |
3705 | end Fold_Ureal; |
3706 | ||
3707 | --------------- | |
3708 | -- From_Bits -- | |
3709 | --------------- | |
3710 | ||
3711 | function From_Bits (B : Bits; T : Entity_Id) return Uint is | |
3712 | V : Uint := Uint_0; | |
3713 | ||
3714 | begin | |
3715 | for J in 0 .. B'Last loop | |
3716 | if B (J) then | |
3717 | V := V + 2 ** J; | |
3718 | end if; | |
3719 | end loop; | |
3720 | ||
3721 | if Non_Binary_Modulus (T) then | |
3722 | V := V mod Modulus (T); | |
3723 | end if; | |
3724 | ||
3725 | return V; | |
3726 | end From_Bits; | |
3727 | ||
3728 | -------------------- | |
3729 | -- Get_String_Val -- | |
3730 | -------------------- | |
3731 | ||
3732 | function Get_String_Val (N : Node_Id) return Node_Id is | |
3733 | begin | |
3734 | if Nkind (N) = N_String_Literal then | |
3735 | return N; | |
3736 | ||
3737 | elsif Nkind (N) = N_Character_Literal then | |
3738 | return N; | |
3739 | ||
3740 | else | |
3741 | pragma Assert (Is_Entity_Name (N)); | |
3742 | return Get_String_Val (Constant_Value (Entity (N))); | |
3743 | end if; | |
3744 | end Get_String_Val; | |
3745 | ||
fbf5a39b AC |
3746 | ---------------- |
3747 | -- Initialize -- | |
3748 | ---------------- | |
3749 | ||
3750 | procedure Initialize is | |
3751 | begin | |
3752 | CV_Cache := (others => (Node_High_Bound, Uint_0)); | |
3753 | end Initialize; | |
3754 | ||
996ae0b0 RK |
3755 | -------------------- |
3756 | -- In_Subrange_Of -- | |
3757 | -------------------- | |
3758 | ||
3759 | function In_Subrange_Of | |
c27f2f15 RD |
3760 | (T1 : Entity_Id; |
3761 | T2 : Entity_Id; | |
3762 | Fixed_Int : Boolean := False) return Boolean | |
996ae0b0 RK |
3763 | is |
3764 | L1 : Node_Id; | |
3765 | H1 : Node_Id; | |
3766 | ||
3767 | L2 : Node_Id; | |
3768 | H2 : Node_Id; | |
3769 | ||
3770 | begin | |
3771 | if T1 = T2 or else Is_Subtype_Of (T1, T2) then | |
3772 | return True; | |
3773 | ||
3774 | -- Never in range if both types are not scalar. Don't know if this can | |
3775 | -- actually happen, but just in case. | |
3776 | ||
3777 | elsif not Is_Scalar_Type (T1) or else not Is_Scalar_Type (T1) then | |
3778 | return False; | |
3779 | ||
d79e621a GD |
3780 | -- If T1 has infinities but T2 doesn't have infinities, then T1 is |
3781 | -- definitely not compatible with T2. | |
3782 | ||
3783 | elsif Is_Floating_Point_Type (T1) | |
3784 | and then Has_Infinities (T1) | |
3785 | and then Is_Floating_Point_Type (T2) | |
3786 | and then not Has_Infinities (T2) | |
3787 | then | |
3788 | return False; | |
3789 | ||
996ae0b0 RK |
3790 | else |
3791 | L1 := Type_Low_Bound (T1); | |
3792 | H1 := Type_High_Bound (T1); | |
3793 | ||
3794 | L2 := Type_Low_Bound (T2); | |
3795 | H2 := Type_High_Bound (T2); | |
3796 | ||
3797 | -- Check bounds to see if comparison possible at compile time | |
3798 | ||
c27f2f15 | 3799 | if Compile_Time_Compare (L1, L2, Assume_Valid => True) in Compare_GE |
996ae0b0 | 3800 | and then |
c27f2f15 | 3801 | Compile_Time_Compare (H1, H2, Assume_Valid => True) in Compare_LE |
996ae0b0 RK |
3802 | then |
3803 | return True; | |
3804 | end if; | |
3805 | ||
3806 | -- If bounds not comparable at compile time, then the bounds of T2 | |
3807 | -- must be compile time known or we cannot answer the query. | |
3808 | ||
3809 | if not Compile_Time_Known_Value (L2) | |
3810 | or else not Compile_Time_Known_Value (H2) | |
3811 | then | |
3812 | return False; | |
3813 | end if; | |
3814 | ||
3815 | -- If the bounds of T1 are know at compile time then use these | |
3816 | -- ones, otherwise use the bounds of the base type (which are of | |
3817 | -- course always static). | |
3818 | ||
3819 | if not Compile_Time_Known_Value (L1) then | |
3820 | L1 := Type_Low_Bound (Base_Type (T1)); | |
3821 | end if; | |
3822 | ||
3823 | if not Compile_Time_Known_Value (H1) then | |
3824 | H1 := Type_High_Bound (Base_Type (T1)); | |
3825 | end if; | |
3826 | ||
3827 | -- Fixed point types should be considered as such only if | |
3828 | -- flag Fixed_Int is set to False. | |
3829 | ||
3830 | if Is_Floating_Point_Type (T1) or else Is_Floating_Point_Type (T2) | |
3831 | or else (Is_Fixed_Point_Type (T1) and then not Fixed_Int) | |
3832 | or else (Is_Fixed_Point_Type (T2) and then not Fixed_Int) | |
3833 | then | |
3834 | return | |
3835 | Expr_Value_R (L2) <= Expr_Value_R (L1) | |
3836 | and then | |
3837 | Expr_Value_R (H2) >= Expr_Value_R (H1); | |
3838 | ||
3839 | else | |
3840 | return | |
3841 | Expr_Value (L2) <= Expr_Value (L1) | |
3842 | and then | |
3843 | Expr_Value (H2) >= Expr_Value (H1); | |
3844 | ||
3845 | end if; | |
3846 | end if; | |
3847 | ||
3848 | -- If any exception occurs, it means that we have some bug in the compiler | |
f3d57416 | 3849 | -- possibly triggered by a previous error, or by some unforeseen peculiar |
996ae0b0 RK |
3850 | -- occurrence. However, this is only an optimization attempt, so there is |
3851 | -- really no point in crashing the compiler. Instead we just decide, too | |
3852 | -- bad, we can't figure out the answer in this case after all. | |
3853 | ||
3854 | exception | |
3855 | when others => | |
3856 | ||
3857 | -- Debug flag K disables this behavior (useful for debugging) | |
3858 | ||
3859 | if Debug_Flag_K then | |
3860 | raise; | |
3861 | else | |
3862 | return False; | |
3863 | end if; | |
3864 | end In_Subrange_Of; | |
3865 | ||
3866 | ----------------- | |
3867 | -- Is_In_Range -- | |
3868 | ----------------- | |
3869 | ||
3870 | function Is_In_Range | |
c800f862 RD |
3871 | (N : Node_Id; |
3872 | Typ : Entity_Id; | |
3873 | Assume_Valid : Boolean := False; | |
3874 | Fixed_Int : Boolean := False; | |
3875 | Int_Real : Boolean := False) return Boolean | |
996ae0b0 RK |
3876 | is |
3877 | Val : Uint; | |
3878 | Valr : Ureal; | |
3879 | ||
c27f2f15 RD |
3880 | pragma Warnings (Off, Assume_Valid); |
3881 | -- For now Assume_Valid is unreferenced since the current implementation | |
3882 | -- always returns False if N is not a compile time known value, but we | |
3883 | -- keep the parameter to allow for future enhancements in which we try | |
3884 | -- to get the information in the variable case as well. | |
3885 | ||
996ae0b0 | 3886 | begin |
82c80734 | 3887 | -- Universal types have no range limits, so always in range |
996ae0b0 RK |
3888 | |
3889 | if Typ = Universal_Integer or else Typ = Universal_Real then | |
3890 | return True; | |
3891 | ||
3892 | -- Never in range if not scalar type. Don't know if this can | |
3893 | -- actually happen, but our spec allows it, so we must check! | |
3894 | ||
3895 | elsif not Is_Scalar_Type (Typ) then | |
3896 | return False; | |
3897 | ||
82c80734 | 3898 | -- Never in range unless we have a compile time known value |
996ae0b0 RK |
3899 | |
3900 | elsif not Compile_Time_Known_Value (N) then | |
3901 | return False; | |
3902 | ||
c800f862 RD |
3903 | -- General processing with a known compile time value |
3904 | ||
996ae0b0 RK |
3905 | else |
3906 | declare | |
c800f862 RD |
3907 | Lo : Node_Id; |
3908 | Hi : Node_Id; | |
3909 | LB_Known : Boolean; | |
3910 | UB_Known : Boolean; | |
996ae0b0 RK |
3911 | |
3912 | begin | |
c27f2f15 RD |
3913 | Lo := Type_Low_Bound (Typ); |
3914 | Hi := Type_High_Bound (Typ); | |
c800f862 RD |
3915 | |
3916 | LB_Known := Compile_Time_Known_Value (Lo); | |
3917 | UB_Known := Compile_Time_Known_Value (Hi); | |
3918 | ||
996ae0b0 RK |
3919 | -- Fixed point types should be considered as such only in |
3920 | -- flag Fixed_Int is set to False. | |
3921 | ||
c27f2f15 RD |
3922 | if Is_Floating_Point_Type (Typ) |
3923 | or else (Is_Fixed_Point_Type (Typ) and then not Fixed_Int) | |
996ae0b0 RK |
3924 | or else Int_Real |
3925 | then | |
3926 | Valr := Expr_Value_R (N); | |
3927 | ||
3928 | if LB_Known and then Valr >= Expr_Value_R (Lo) | |
3929 | and then UB_Known and then Valr <= Expr_Value_R (Hi) | |
3930 | then | |
3931 | return True; | |
3932 | else | |
3933 | return False; | |
3934 | end if; | |
3935 | ||
3936 | else | |
3937 | Val := Expr_Value (N); | |
3938 | ||
3939 | if LB_Known and then Val >= Expr_Value (Lo) | |
3940 | and then UB_Known and then Val <= Expr_Value (Hi) | |
3941 | then | |
3942 | return True; | |
3943 | else | |
3944 | return False; | |
3945 | end if; | |
3946 | end if; | |
3947 | end; | |
3948 | end if; | |
3949 | end Is_In_Range; | |
3950 | ||
3951 | ------------------- | |
3952 | -- Is_Null_Range -- | |
3953 | ------------------- | |
3954 | ||
3955 | function Is_Null_Range (Lo : Node_Id; Hi : Node_Id) return Boolean is | |
3956 | Typ : constant Entity_Id := Etype (Lo); | |
3957 | ||
3958 | begin | |
3959 | if not Compile_Time_Known_Value (Lo) | |
3960 | or else not Compile_Time_Known_Value (Hi) | |
3961 | then | |
3962 | return False; | |
3963 | end if; | |
3964 | ||
3965 | if Is_Discrete_Type (Typ) then | |
3966 | return Expr_Value (Lo) > Expr_Value (Hi); | |
3967 | ||
3968 | else | |
3969 | pragma Assert (Is_Real_Type (Typ)); | |
3970 | return Expr_Value_R (Lo) > Expr_Value_R (Hi); | |
3971 | end if; | |
3972 | end Is_Null_Range; | |
3973 | ||
3974 | ----------------------------- | |
3975 | -- Is_OK_Static_Expression -- | |
3976 | ----------------------------- | |
3977 | ||
3978 | function Is_OK_Static_Expression (N : Node_Id) return Boolean is | |
3979 | begin | |
3980 | return Is_Static_Expression (N) | |
3981 | and then not Raises_Constraint_Error (N); | |
3982 | end Is_OK_Static_Expression; | |
3983 | ||
3984 | ------------------------ | |
3985 | -- Is_OK_Static_Range -- | |
3986 | ------------------------ | |
3987 | ||
3988 | -- A static range is a range whose bounds are static expressions, or a | |
3989 | -- Range_Attribute_Reference equivalent to such a range (RM 4.9(26)). | |
3990 | -- We have already converted range attribute references, so we get the | |
3991 | -- "or" part of this rule without needing a special test. | |
3992 | ||
3993 | function Is_OK_Static_Range (N : Node_Id) return Boolean is | |
3994 | begin | |
3995 | return Is_OK_Static_Expression (Low_Bound (N)) | |
3996 | and then Is_OK_Static_Expression (High_Bound (N)); | |
3997 | end Is_OK_Static_Range; | |
3998 | ||
3999 | -------------------------- | |
4000 | -- Is_OK_Static_Subtype -- | |
4001 | -------------------------- | |
4002 | ||
4003 | -- Determines if Typ is a static subtype as defined in (RM 4.9(26)) | |
4004 | -- where neither bound raises constraint error when evaluated. | |
4005 | ||
4006 | function Is_OK_Static_Subtype (Typ : Entity_Id) return Boolean is | |
4007 | Base_T : constant Entity_Id := Base_Type (Typ); | |
4008 | Anc_Subt : Entity_Id; | |
4009 | ||
4010 | begin | |
4011 | -- First a quick check on the non static subtype flag. As described | |
4012 | -- in further detail in Einfo, this flag is not decisive in all cases, | |
4013 | -- but if it is set, then the subtype is definitely non-static. | |
4014 | ||
4015 | if Is_Non_Static_Subtype (Typ) then | |
4016 | return False; | |
4017 | end if; | |
4018 | ||
4019 | Anc_Subt := Ancestor_Subtype (Typ); | |
4020 | ||
4021 | if Anc_Subt = Empty then | |
4022 | Anc_Subt := Base_T; | |
4023 | end if; | |
4024 | ||
4025 | if Is_Generic_Type (Root_Type (Base_T)) | |
4026 | or else Is_Generic_Actual_Type (Base_T) | |
4027 | then | |
4028 | return False; | |
4029 | ||
4030 | -- String types | |
4031 | ||
4032 | elsif Is_String_Type (Typ) then | |
4033 | return | |
4034 | Ekind (Typ) = E_String_Literal_Subtype | |
4035 | or else | |
4036 | (Is_OK_Static_Subtype (Component_Type (Typ)) | |
4037 | and then Is_OK_Static_Subtype (Etype (First_Index (Typ)))); | |
4038 | ||
4039 | -- Scalar types | |
4040 | ||
4041 | elsif Is_Scalar_Type (Typ) then | |
4042 | if Base_T = Typ then | |
4043 | return True; | |
4044 | ||
4045 | else | |
4046 | -- Scalar_Range (Typ) might be an N_Subtype_Indication, so | |
4047 | -- use Get_Type_Low,High_Bound. | |
4048 | ||
4049 | return Is_OK_Static_Subtype (Anc_Subt) | |
4050 | and then Is_OK_Static_Expression (Type_Low_Bound (Typ)) | |
4051 | and then Is_OK_Static_Expression (Type_High_Bound (Typ)); | |
4052 | end if; | |
4053 | ||
4054 | -- Types other than string and scalar types are never static | |
4055 | ||
4056 | else | |
4057 | return False; | |
4058 | end if; | |
4059 | end Is_OK_Static_Subtype; | |
4060 | ||
4061 | --------------------- | |
4062 | -- Is_Out_Of_Range -- | |
4063 | --------------------- | |
4064 | ||
4065 | function Is_Out_Of_Range | |
1c7717c3 AC |
4066 | (N : Node_Id; |
4067 | Typ : Entity_Id; | |
c800f862 | 4068 | Assume_Valid : Boolean := False; |
1c7717c3 AC |
4069 | Fixed_Int : Boolean := False; |
4070 | Int_Real : Boolean := False) return Boolean | |
996ae0b0 RK |
4071 | is |
4072 | Val : Uint; | |
4073 | Valr : Ureal; | |
4074 | ||
c27f2f15 RD |
4075 | pragma Warnings (Off, Assume_Valid); |
4076 | -- For now Assume_Valid is unreferenced since the current implementation | |
4077 | -- always returns False if N is not a compile time known value, but we | |
4078 | -- keep the parameter to allow for future enhancements in which we try | |
4079 | -- to get the information in the variable case as well. | |
4080 | ||
996ae0b0 | 4081 | begin |
82c80734 | 4082 | -- Universal types have no range limits, so always in range |
996ae0b0 RK |
4083 | |
4084 | if Typ = Universal_Integer or else Typ = Universal_Real then | |
4085 | return False; | |
4086 | ||
4087 | -- Never out of range if not scalar type. Don't know if this can | |
4088 | -- actually happen, but our spec allows it, so we must check! | |
4089 | ||
4090 | elsif not Is_Scalar_Type (Typ) then | |
4091 | return False; | |
4092 | ||
4093 | -- Never out of range if this is a generic type, since the bounds | |
4094 | -- of generic types are junk. Note that if we only checked for | |
4095 | -- static expressions (instead of compile time known values) below, | |
4096 | -- we would not need this check, because values of a generic type | |
4097 | -- can never be static, but they can be known at compile time. | |
4098 | ||
4099 | elsif Is_Generic_Type (Typ) then | |
4100 | return False; | |
4101 | ||
fbf5a39b | 4102 | -- Never out of range unless we have a compile time known value |
996ae0b0 RK |
4103 | |
4104 | elsif not Compile_Time_Known_Value (N) then | |
4105 | return False; | |
4106 | ||
4107 | else | |
4108 | declare | |
c800f862 RD |
4109 | Lo : Node_Id; |
4110 | Hi : Node_Id; | |
4111 | LB_Known : Boolean; | |
4112 | UB_Known : Boolean; | |
996ae0b0 RK |
4113 | |
4114 | begin | |
c27f2f15 RD |
4115 | Lo := Type_Low_Bound (Typ); |
4116 | Hi := Type_High_Bound (Typ); | |
c800f862 RD |
4117 | |
4118 | LB_Known := Compile_Time_Known_Value (Lo); | |
4119 | UB_Known := Compile_Time_Known_Value (Hi); | |
4120 | ||
996ae0b0 RK |
4121 | -- Real types (note that fixed-point types are not treated |
4122 | -- as being of a real type if the flag Fixed_Int is set, | |
4123 | -- since in that case they are regarded as integer types). | |
4124 | ||
c27f2f15 RD |
4125 | if Is_Floating_Point_Type (Typ) |
4126 | or else (Is_Fixed_Point_Type (Typ) and then not Fixed_Int) | |
996ae0b0 RK |
4127 | or else Int_Real |
4128 | then | |
4129 | Valr := Expr_Value_R (N); | |
4130 | ||
4131 | if LB_Known and then Valr < Expr_Value_R (Lo) then | |
4132 | return True; | |
4133 | ||
4134 | elsif UB_Known and then Expr_Value_R (Hi) < Valr then | |
4135 | return True; | |
4136 | ||
4137 | else | |
4138 | return False; | |
4139 | end if; | |
4140 | ||
4141 | else | |
4142 | Val := Expr_Value (N); | |
4143 | ||
4144 | if LB_Known and then Val < Expr_Value (Lo) then | |
4145 | return True; | |
4146 | ||
4147 | elsif UB_Known and then Expr_Value (Hi) < Val then | |
4148 | return True; | |
4149 | ||
4150 | else | |
4151 | return False; | |
4152 | end if; | |
4153 | end if; | |
4154 | end; | |
4155 | end if; | |
4156 | end Is_Out_Of_Range; | |
4157 | ||
4158 | --------------------- | |
4159 | -- Is_Static_Range -- | |
4160 | --------------------- | |
4161 | ||
4162 | -- A static range is a range whose bounds are static expressions, or a | |
4163 | -- Range_Attribute_Reference equivalent to such a range (RM 4.9(26)). | |
4164 | -- We have already converted range attribute references, so we get the | |
4165 | -- "or" part of this rule without needing a special test. | |
4166 | ||
4167 | function Is_Static_Range (N : Node_Id) return Boolean is | |
4168 | begin | |
4169 | return Is_Static_Expression (Low_Bound (N)) | |
4170 | and then Is_Static_Expression (High_Bound (N)); | |
4171 | end Is_Static_Range; | |
4172 | ||
4173 | ----------------------- | |
4174 | -- Is_Static_Subtype -- | |
4175 | ----------------------- | |
4176 | ||
82c80734 | 4177 | -- Determines if Typ is a static subtype as defined in (RM 4.9(26)) |
996ae0b0 RK |
4178 | |
4179 | function Is_Static_Subtype (Typ : Entity_Id) return Boolean is | |
4180 | Base_T : constant Entity_Id := Base_Type (Typ); | |
4181 | Anc_Subt : Entity_Id; | |
4182 | ||
4183 | begin | |
4184 | -- First a quick check on the non static subtype flag. As described | |
4185 | -- in further detail in Einfo, this flag is not decisive in all cases, | |
4186 | -- but if it is set, then the subtype is definitely non-static. | |
4187 | ||
4188 | if Is_Non_Static_Subtype (Typ) then | |
4189 | return False; | |
4190 | end if; | |
4191 | ||
4192 | Anc_Subt := Ancestor_Subtype (Typ); | |
4193 | ||
4194 | if Anc_Subt = Empty then | |
4195 | Anc_Subt := Base_T; | |
4196 | end if; | |
4197 | ||
4198 | if Is_Generic_Type (Root_Type (Base_T)) | |
4199 | or else Is_Generic_Actual_Type (Base_T) | |
4200 | then | |
4201 | return False; | |
4202 | ||
4203 | -- String types | |
4204 | ||
4205 | elsif Is_String_Type (Typ) then | |
4206 | return | |
4207 | Ekind (Typ) = E_String_Literal_Subtype | |
4208 | or else | |
4209 | (Is_Static_Subtype (Component_Type (Typ)) | |
4210 | and then Is_Static_Subtype (Etype (First_Index (Typ)))); | |
4211 | ||
4212 | -- Scalar types | |
4213 | ||
4214 | elsif Is_Scalar_Type (Typ) then | |
4215 | if Base_T = Typ then | |
4216 | return True; | |
4217 | ||
4218 | else | |
4219 | return Is_Static_Subtype (Anc_Subt) | |
4220 | and then Is_Static_Expression (Type_Low_Bound (Typ)) | |
4221 | and then Is_Static_Expression (Type_High_Bound (Typ)); | |
4222 | end if; | |
4223 | ||
4224 | -- Types other than string and scalar types are never static | |
4225 | ||
4226 | else | |
4227 | return False; | |
4228 | end if; | |
4229 | end Is_Static_Subtype; | |
4230 | ||
4231 | -------------------- | |
4232 | -- Not_Null_Range -- | |
4233 | -------------------- | |
4234 | ||
4235 | function Not_Null_Range (Lo : Node_Id; Hi : Node_Id) return Boolean is | |
4236 | Typ : constant Entity_Id := Etype (Lo); | |
4237 | ||
4238 | begin | |
4239 | if not Compile_Time_Known_Value (Lo) | |
4240 | or else not Compile_Time_Known_Value (Hi) | |
4241 | then | |
4242 | return False; | |
4243 | end if; | |
4244 | ||
4245 | if Is_Discrete_Type (Typ) then | |
4246 | return Expr_Value (Lo) <= Expr_Value (Hi); | |
4247 | ||
4248 | else | |
4249 | pragma Assert (Is_Real_Type (Typ)); | |
4250 | ||
4251 | return Expr_Value_R (Lo) <= Expr_Value_R (Hi); | |
4252 | end if; | |
4253 | end Not_Null_Range; | |
4254 | ||
4255 | ------------- | |
4256 | -- OK_Bits -- | |
4257 | ------------- | |
4258 | ||
4259 | function OK_Bits (N : Node_Id; Bits : Uint) return Boolean is | |
4260 | begin | |
4261 | -- We allow a maximum of 500,000 bits which seems a reasonable limit | |
4262 | ||
4263 | if Bits < 500_000 then | |
4264 | return True; | |
4265 | ||
4266 | else | |
4267 | Error_Msg_N ("static value too large, capacity exceeded", N); | |
4268 | return False; | |
4269 | end if; | |
4270 | end OK_Bits; | |
4271 | ||
4272 | ------------------ | |
4273 | -- Out_Of_Range -- | |
4274 | ------------------ | |
4275 | ||
4276 | procedure Out_Of_Range (N : Node_Id) is | |
4277 | begin | |
4278 | -- If we have the static expression case, then this is an illegality | |
4279 | -- in Ada 95 mode, except that in an instance, we never generate an | |
4280 | -- error (if the error is legitimate, it was already diagnosed in | |
4281 | -- the template). The expression to compute the length of a packed | |
4282 | -- array is attached to the array type itself, and deserves a separate | |
4283 | -- message. | |
4284 | ||
4285 | if Is_Static_Expression (N) | |
4286 | and then not In_Instance | |
fbf5a39b | 4287 | and then not In_Inlined_Body |
0ab80019 | 4288 | and then Ada_Version >= Ada_95 |
996ae0b0 | 4289 | then |
996ae0b0 RK |
4290 | if Nkind (Parent (N)) = N_Defining_Identifier |
4291 | and then Is_Array_Type (Parent (N)) | |
4292 | and then Present (Packed_Array_Type (Parent (N))) | |
4293 | and then Present (First_Rep_Item (Parent (N))) | |
4294 | then | |
4295 | Error_Msg_N | |
4296 | ("length of packed array must not exceed Integer''Last", | |
4297 | First_Rep_Item (Parent (N))); | |
4298 | Rewrite (N, Make_Integer_Literal (Sloc (N), Uint_1)); | |
4299 | ||
4300 | else | |
4301 | Apply_Compile_Time_Constraint_Error | |
07fc65c4 | 4302 | (N, "value not in range of}", CE_Range_Check_Failed); |
996ae0b0 RK |
4303 | end if; |
4304 | ||
4305 | -- Here we generate a warning for the Ada 83 case, or when we are | |
4306 | -- in an instance, or when we have a non-static expression case. | |
4307 | ||
4308 | else | |
996ae0b0 | 4309 | Apply_Compile_Time_Constraint_Error |
07fc65c4 | 4310 | (N, "value not in range of}?", CE_Range_Check_Failed); |
996ae0b0 RK |
4311 | end if; |
4312 | end Out_Of_Range; | |
4313 | ||
4314 | ------------------------- | |
4315 | -- Rewrite_In_Raise_CE -- | |
4316 | ------------------------- | |
4317 | ||
4318 | procedure Rewrite_In_Raise_CE (N : Node_Id; Exp : Node_Id) is | |
4319 | Typ : constant Entity_Id := Etype (N); | |
4320 | ||
4321 | begin | |
4322 | -- If we want to raise CE in the condition of a raise_CE node | |
4323 | -- we may as well get rid of the condition | |
4324 | ||
4325 | if Present (Parent (N)) | |
4326 | and then Nkind (Parent (N)) = N_Raise_Constraint_Error | |
4327 | then | |
4328 | Set_Condition (Parent (N), Empty); | |
4329 | ||
4330 | -- If the expression raising CE is a N_Raise_CE node, we can use | |
4331 | -- that one. We just preserve the type of the context | |
4332 | ||
4333 | elsif Nkind (Exp) = N_Raise_Constraint_Error then | |
4334 | Rewrite (N, Exp); | |
4335 | Set_Etype (N, Typ); | |
4336 | ||
4337 | -- We have to build an explicit raise_ce node | |
4338 | ||
4339 | else | |
07fc65c4 GB |
4340 | Rewrite (N, |
4341 | Make_Raise_Constraint_Error (Sloc (Exp), | |
4342 | Reason => CE_Range_Check_Failed)); | |
996ae0b0 RK |
4343 | Set_Raises_Constraint_Error (N); |
4344 | Set_Etype (N, Typ); | |
4345 | end if; | |
4346 | end Rewrite_In_Raise_CE; | |
4347 | ||
4348 | --------------------- | |
4349 | -- String_Type_Len -- | |
4350 | --------------------- | |
4351 | ||
4352 | function String_Type_Len (Stype : Entity_Id) return Uint is | |
4353 | NT : constant Entity_Id := Etype (First_Index (Stype)); | |
4354 | T : Entity_Id; | |
4355 | ||
4356 | begin | |
4357 | if Is_OK_Static_Subtype (NT) then | |
4358 | T := NT; | |
4359 | else | |
4360 | T := Base_Type (NT); | |
4361 | end if; | |
4362 | ||
4363 | return Expr_Value (Type_High_Bound (T)) - | |
4364 | Expr_Value (Type_Low_Bound (T)) + 1; | |
4365 | end String_Type_Len; | |
4366 | ||
4367 | ------------------------------------ | |
4368 | -- Subtypes_Statically_Compatible -- | |
4369 | ------------------------------------ | |
4370 | ||
4371 | function Subtypes_Statically_Compatible | |
f44fe430 RD |
4372 | (T1 : Entity_Id; |
4373 | T2 : Entity_Id) return Boolean | |
996ae0b0 RK |
4374 | is |
4375 | begin | |
4376 | if Is_Scalar_Type (T1) then | |
4377 | ||
4378 | -- Definitely compatible if we match | |
4379 | ||
4380 | if Subtypes_Statically_Match (T1, T2) then | |
4381 | return True; | |
4382 | ||
4383 | -- If either subtype is nonstatic then they're not compatible | |
4384 | ||
4385 | elsif not Is_Static_Subtype (T1) | |
4386 | or else not Is_Static_Subtype (T2) | |
4387 | then | |
4388 | return False; | |
4389 | ||
4390 | -- If either type has constraint error bounds, then consider that | |
4391 | -- they match to avoid junk cascaded errors here. | |
4392 | ||
4393 | elsif not Is_OK_Static_Subtype (T1) | |
4394 | or else not Is_OK_Static_Subtype (T2) | |
4395 | then | |
4396 | return True; | |
4397 | ||
4398 | -- Base types must match, but we don't check that (should | |
4399 | -- we???) but we do at least check that both types are | |
4400 | -- real, or both types are not real. | |
4401 | ||
fbf5a39b | 4402 | elsif Is_Real_Type (T1) /= Is_Real_Type (T2) then |
996ae0b0 RK |
4403 | return False; |
4404 | ||
4405 | -- Here we check the bounds | |
4406 | ||
4407 | else | |
4408 | declare | |
4409 | LB1 : constant Node_Id := Type_Low_Bound (T1); | |
4410 | HB1 : constant Node_Id := Type_High_Bound (T1); | |
4411 | LB2 : constant Node_Id := Type_Low_Bound (T2); | |
4412 | HB2 : constant Node_Id := Type_High_Bound (T2); | |
4413 | ||
4414 | begin | |
4415 | if Is_Real_Type (T1) then | |
4416 | return | |
4417 | (Expr_Value_R (LB1) > Expr_Value_R (HB1)) | |
4418 | or else | |
4419 | (Expr_Value_R (LB2) <= Expr_Value_R (LB1) | |
4420 | and then | |
4421 | Expr_Value_R (HB1) <= Expr_Value_R (HB2)); | |
4422 | ||
4423 | else | |
4424 | return | |
4425 | (Expr_Value (LB1) > Expr_Value (HB1)) | |
4426 | or else | |
4427 | (Expr_Value (LB2) <= Expr_Value (LB1) | |
4428 | and then | |
4429 | Expr_Value (HB1) <= Expr_Value (HB2)); | |
4430 | end if; | |
4431 | end; | |
4432 | end if; | |
4433 | ||
4434 | elsif Is_Access_Type (T1) then | |
4435 | return not Is_Constrained (T2) | |
4436 | or else Subtypes_Statically_Match | |
4437 | (Designated_Type (T1), Designated_Type (T2)); | |
4438 | ||
4439 | else | |
4440 | return (Is_Composite_Type (T1) and then not Is_Constrained (T2)) | |
4441 | or else Subtypes_Statically_Match (T1, T2); | |
4442 | end if; | |
4443 | end Subtypes_Statically_Compatible; | |
4444 | ||
4445 | ------------------------------- | |
4446 | -- Subtypes_Statically_Match -- | |
4447 | ------------------------------- | |
4448 | ||
4449 | -- Subtypes statically match if they have statically matching constraints | |
4450 | -- (RM 4.9.1(2)). Constraints statically match if there are none, or if | |
4451 | -- they are the same identical constraint, or if they are static and the | |
4452 | -- values match (RM 4.9.1(1)). | |
4453 | ||
4454 | function Subtypes_Statically_Match (T1, T2 : Entity_Id) return Boolean is | |
4455 | begin | |
4456 | -- A type always statically matches itself | |
4457 | ||
4458 | if T1 = T2 then | |
4459 | return True; | |
4460 | ||
4461 | -- Scalar types | |
4462 | ||
4463 | elsif Is_Scalar_Type (T1) then | |
4464 | ||
4465 | -- Base types must be the same | |
4466 | ||
4467 | if Base_Type (T1) /= Base_Type (T2) then | |
4468 | return False; | |
4469 | end if; | |
4470 | ||
4471 | -- A constrained numeric subtype never matches an unconstrained | |
4472 | -- subtype, i.e. both types must be constrained or unconstrained. | |
4473 | ||
4474 | -- To understand the requirement for this test, see RM 4.9.1(1). | |
4475 | -- As is made clear in RM 3.5.4(11), type Integer, for example | |
4476 | -- is a constrained subtype with constraint bounds matching the | |
f3d57416 | 4477 | -- bounds of its corresponding unconstrained base type. In this |
996ae0b0 RK |
4478 | -- situation, Integer and Integer'Base do not statically match, |
4479 | -- even though they have the same bounds. | |
4480 | ||
4481 | -- We only apply this test to types in Standard and types that | |
4482 | -- appear in user programs. That way, we do not have to be | |
4483 | -- too careful about setting Is_Constrained right for itypes. | |
4484 | ||
4485 | if Is_Numeric_Type (T1) | |
4486 | and then (Is_Constrained (T1) /= Is_Constrained (T2)) | |
4487 | and then (Scope (T1) = Standard_Standard | |
4488 | or else Comes_From_Source (T1)) | |
4489 | and then (Scope (T2) = Standard_Standard | |
4490 | or else Comes_From_Source (T2)) | |
4491 | then | |
4492 | return False; | |
82c80734 RD |
4493 | |
4494 | -- A generic scalar type does not statically match its base | |
4495 | -- type (AI-311). In this case we make sure that the formals, | |
4496 | -- which are first subtypes of their bases, are constrained. | |
4497 | ||
4498 | elsif Is_Generic_Type (T1) | |
4499 | and then Is_Generic_Type (T2) | |
4500 | and then (Is_Constrained (T1) /= Is_Constrained (T2)) | |
4501 | then | |
4502 | return False; | |
996ae0b0 RK |
4503 | end if; |
4504 | ||
4505 | -- If there was an error in either range, then just assume | |
4506 | -- the types statically match to avoid further junk errors | |
4507 | ||
4508 | if Error_Posted (Scalar_Range (T1)) | |
4509 | or else | |
4510 | Error_Posted (Scalar_Range (T2)) | |
4511 | then | |
4512 | return True; | |
4513 | end if; | |
4514 | ||
4515 | -- Otherwise both types have bound that can be compared | |
4516 | ||
4517 | declare | |
4518 | LB1 : constant Node_Id := Type_Low_Bound (T1); | |
4519 | HB1 : constant Node_Id := Type_High_Bound (T1); | |
4520 | LB2 : constant Node_Id := Type_Low_Bound (T2); | |
4521 | HB2 : constant Node_Id := Type_High_Bound (T2); | |
4522 | ||
4523 | begin | |
4524 | -- If the bounds are the same tree node, then match | |
4525 | ||
4526 | if LB1 = LB2 and then HB1 = HB2 then | |
4527 | return True; | |
4528 | ||
4529 | -- Otherwise bounds must be static and identical value | |
4530 | ||
4531 | else | |
4532 | if not Is_Static_Subtype (T1) | |
4533 | or else not Is_Static_Subtype (T2) | |
4534 | then | |
4535 | return False; | |
4536 | ||
4537 | -- If either type has constraint error bounds, then say | |
4538 | -- that they match to avoid junk cascaded errors here. | |
4539 | ||
4540 | elsif not Is_OK_Static_Subtype (T1) | |
4541 | or else not Is_OK_Static_Subtype (T2) | |
4542 | then | |
4543 | return True; | |
4544 | ||
4545 | elsif Is_Real_Type (T1) then | |
4546 | return | |
4547 | (Expr_Value_R (LB1) = Expr_Value_R (LB2)) | |
4548 | and then | |
4549 | (Expr_Value_R (HB1) = Expr_Value_R (HB2)); | |
4550 | ||
4551 | else | |
4552 | return | |
4553 | Expr_Value (LB1) = Expr_Value (LB2) | |
4554 | and then | |
4555 | Expr_Value (HB1) = Expr_Value (HB2); | |
4556 | end if; | |
4557 | end if; | |
4558 | end; | |
4559 | ||
4560 | -- Type with discriminants | |
4561 | ||
4562 | elsif Has_Discriminants (T1) or else Has_Discriminants (T2) then | |
6eaf4095 | 4563 | |
c2bf339e GD |
4564 | -- Because of view exchanges in multiple instantiations, conformance |
4565 | -- checking might try to match a partial view of a type with no | |
4566 | -- discriminants with a full view that has defaulted discriminants. | |
4567 | -- In such a case, use the discriminant constraint of the full view, | |
4568 | -- which must exist because we know that the two subtypes have the | |
4569 | -- same base type. | |
6eaf4095 | 4570 | |
996ae0b0 | 4571 | if Has_Discriminants (T1) /= Has_Discriminants (T2) then |
c2bf339e GD |
4572 | if In_Instance then |
4573 | if Is_Private_Type (T2) | |
4574 | and then Present (Full_View (T2)) | |
4575 | and then Has_Discriminants (Full_View (T2)) | |
4576 | then | |
4577 | return Subtypes_Statically_Match (T1, Full_View (T2)); | |
4578 | ||
4579 | elsif Is_Private_Type (T1) | |
4580 | and then Present (Full_View (T1)) | |
4581 | and then Has_Discriminants (Full_View (T1)) | |
4582 | then | |
4583 | return Subtypes_Statically_Match (Full_View (T1), T2); | |
4584 | ||
4585 | else | |
4586 | return False; | |
4587 | end if; | |
6eaf4095 ES |
4588 | else |
4589 | return False; | |
4590 | end if; | |
996ae0b0 RK |
4591 | end if; |
4592 | ||
4593 | declare | |
4594 | DL1 : constant Elist_Id := Discriminant_Constraint (T1); | |
4595 | DL2 : constant Elist_Id := Discriminant_Constraint (T2); | |
4596 | ||
13f34a3f RD |
4597 | DA1 : Elmt_Id; |
4598 | DA2 : Elmt_Id; | |
996ae0b0 RK |
4599 | |
4600 | begin | |
4601 | if DL1 = DL2 then | |
4602 | return True; | |
996ae0b0 RK |
4603 | elsif Is_Constrained (T1) /= Is_Constrained (T2) then |
4604 | return False; | |
4605 | end if; | |
4606 | ||
13f34a3f | 4607 | -- Now loop through the discriminant constraints |
996ae0b0 | 4608 | |
13f34a3f RD |
4609 | -- Note: the guard here seems necessary, since it is possible at |
4610 | -- least for DL1 to be No_Elist. Not clear this is reasonable ??? | |
996ae0b0 | 4611 | |
13f34a3f RD |
4612 | if Present (DL1) and then Present (DL2) then |
4613 | DA1 := First_Elmt (DL1); | |
4614 | DA2 := First_Elmt (DL2); | |
4615 | while Present (DA1) loop | |
4616 | declare | |
4617 | Expr1 : constant Node_Id := Node (DA1); | |
4618 | Expr2 : constant Node_Id := Node (DA2); | |
996ae0b0 | 4619 | |
13f34a3f RD |
4620 | begin |
4621 | if not Is_Static_Expression (Expr1) | |
4622 | or else not Is_Static_Expression (Expr2) | |
4623 | then | |
4624 | return False; | |
996ae0b0 | 4625 | |
13f34a3f RD |
4626 | -- If either expression raised a constraint error, |
4627 | -- consider the expressions as matching, since this | |
4628 | -- helps to prevent cascading errors. | |
4629 | ||
4630 | elsif Raises_Constraint_Error (Expr1) | |
4631 | or else Raises_Constraint_Error (Expr2) | |
4632 | then | |
4633 | null; | |
4634 | ||
4635 | elsif Expr_Value (Expr1) /= Expr_Value (Expr2) then | |
4636 | return False; | |
4637 | end if; | |
4638 | end; | |
996ae0b0 | 4639 | |
13f34a3f RD |
4640 | Next_Elmt (DA1); |
4641 | Next_Elmt (DA2); | |
4642 | end loop; | |
4643 | end if; | |
996ae0b0 RK |
4644 | end; |
4645 | ||
4646 | return True; | |
4647 | ||
82c80734 | 4648 | -- A definite type does not match an indefinite or classwide type |
0356699b RD |
4649 | -- However, a generic type with unknown discriminants may be |
4650 | -- instantiated with a type with no discriminants, and conformance | |
4651 | -- checking on an inherited operation may compare the actual with | |
4652 | -- the subtype that renames it in the instance. | |
996ae0b0 RK |
4653 | |
4654 | elsif | |
4655 | Has_Unknown_Discriminants (T1) /= Has_Unknown_Discriminants (T2) | |
4656 | then | |
7a3f77d2 AC |
4657 | return |
4658 | Is_Generic_Actual_Type (T1) or else Is_Generic_Actual_Type (T2); | |
996ae0b0 RK |
4659 | |
4660 | -- Array type | |
4661 | ||
4662 | elsif Is_Array_Type (T1) then | |
4663 | ||
4664 | -- If either subtype is unconstrained then both must be, | |
4665 | -- and if both are unconstrained then no further checking | |
4666 | -- is needed. | |
4667 | ||
4668 | if not Is_Constrained (T1) or else not Is_Constrained (T2) then | |
4669 | return not (Is_Constrained (T1) or else Is_Constrained (T2)); | |
4670 | end if; | |
4671 | ||
4672 | -- Both subtypes are constrained, so check that the index | |
4673 | -- subtypes statically match. | |
4674 | ||
4675 | declare | |
4676 | Index1 : Node_Id := First_Index (T1); | |
4677 | Index2 : Node_Id := First_Index (T2); | |
4678 | ||
4679 | begin | |
4680 | while Present (Index1) loop | |
4681 | if not | |
4682 | Subtypes_Statically_Match (Etype (Index1), Etype (Index2)) | |
4683 | then | |
4684 | return False; | |
4685 | end if; | |
4686 | ||
4687 | Next_Index (Index1); | |
4688 | Next_Index (Index2); | |
4689 | end loop; | |
4690 | ||
4691 | return True; | |
4692 | end; | |
4693 | ||
4694 | elsif Is_Access_Type (T1) then | |
b5bd964f ES |
4695 | if Can_Never_Be_Null (T1) /= Can_Never_Be_Null (T2) then |
4696 | return False; | |
4697 | ||
7a3f77d2 AC |
4698 | elsif Ekind (T1) = E_Access_Subprogram_Type |
4699 | or else Ekind (T1) = E_Anonymous_Access_Subprogram_Type | |
4700 | then | |
b5bd964f ES |
4701 | return |
4702 | Subtype_Conformant | |
4703 | (Designated_Type (T1), | |
bb98fe75 | 4704 | Designated_Type (T2)); |
b5bd964f ES |
4705 | else |
4706 | return | |
4707 | Subtypes_Statically_Match | |
4708 | (Designated_Type (T1), | |
4709 | Designated_Type (T2)) | |
4710 | and then Is_Access_Constant (T1) = Is_Access_Constant (T2); | |
4711 | end if; | |
996ae0b0 RK |
4712 | |
4713 | -- All other types definitely match | |
4714 | ||
4715 | else | |
4716 | return True; | |
4717 | end if; | |
4718 | end Subtypes_Statically_Match; | |
4719 | ||
4720 | ---------- | |
4721 | -- Test -- | |
4722 | ---------- | |
4723 | ||
4724 | function Test (Cond : Boolean) return Uint is | |
4725 | begin | |
4726 | if Cond then | |
4727 | return Uint_1; | |
4728 | else | |
4729 | return Uint_0; | |
4730 | end if; | |
4731 | end Test; | |
4732 | ||
4733 | --------------------------------- | |
4734 | -- Test_Expression_Is_Foldable -- | |
4735 | --------------------------------- | |
4736 | ||
4737 | -- One operand case | |
4738 | ||
4739 | procedure Test_Expression_Is_Foldable | |
4740 | (N : Node_Id; | |
4741 | Op1 : Node_Id; | |
4742 | Stat : out Boolean; | |
4743 | Fold : out Boolean) | |
4744 | is | |
4745 | begin | |
4746 | Stat := False; | |
0356699b RD |
4747 | Fold := False; |
4748 | ||
4749 | if Debug_Flag_Dot_F and then In_Extended_Main_Source_Unit (N) then | |
4750 | return; | |
4751 | end if; | |
996ae0b0 RK |
4752 | |
4753 | -- If operand is Any_Type, just propagate to result and do not | |
4754 | -- try to fold, this prevents cascaded errors. | |
4755 | ||
4756 | if Etype (Op1) = Any_Type then | |
4757 | Set_Etype (N, Any_Type); | |
996ae0b0 RK |
4758 | return; |
4759 | ||
4760 | -- If operand raises constraint error, then replace node N with the | |
4761 | -- raise constraint error node, and we are obviously not foldable. | |
4762 | -- Note that this replacement inherits the Is_Static_Expression flag | |
4763 | -- from the operand. | |
4764 | ||
4765 | elsif Raises_Constraint_Error (Op1) then | |
4766 | Rewrite_In_Raise_CE (N, Op1); | |
996ae0b0 RK |
4767 | return; |
4768 | ||
4769 | -- If the operand is not static, then the result is not static, and | |
4770 | -- all we have to do is to check the operand since it is now known | |
4771 | -- to appear in a non-static context. | |
4772 | ||
4773 | elsif not Is_Static_Expression (Op1) then | |
4774 | Check_Non_Static_Context (Op1); | |
4775 | Fold := Compile_Time_Known_Value (Op1); | |
4776 | return; | |
4777 | ||
4778 | -- An expression of a formal modular type is not foldable because | |
4779 | -- the modulus is unknown. | |
4780 | ||
4781 | elsif Is_Modular_Integer_Type (Etype (Op1)) | |
4782 | and then Is_Generic_Type (Etype (Op1)) | |
4783 | then | |
4784 | Check_Non_Static_Context (Op1); | |
996ae0b0 RK |
4785 | return; |
4786 | ||
4787 | -- Here we have the case of an operand whose type is OK, which is | |
4788 | -- static, and which does not raise constraint error, we can fold. | |
4789 | ||
4790 | else | |
4791 | Set_Is_Static_Expression (N); | |
4792 | Fold := True; | |
4793 | Stat := True; | |
4794 | end if; | |
4795 | end Test_Expression_Is_Foldable; | |
4796 | ||
4797 | -- Two operand case | |
4798 | ||
4799 | procedure Test_Expression_Is_Foldable | |
4800 | (N : Node_Id; | |
4801 | Op1 : Node_Id; | |
4802 | Op2 : Node_Id; | |
4803 | Stat : out Boolean; | |
4804 | Fold : out Boolean) | |
4805 | is | |
4806 | Rstat : constant Boolean := Is_Static_Expression (Op1) | |
4807 | and then Is_Static_Expression (Op2); | |
4808 | ||
4809 | begin | |
4810 | Stat := False; | |
0356699b RD |
4811 | Fold := False; |
4812 | ||
4813 | if Debug_Flag_Dot_F and then In_Extended_Main_Source_Unit (N) then | |
4814 | return; | |
4815 | end if; | |
996ae0b0 RK |
4816 | |
4817 | -- If either operand is Any_Type, just propagate to result and | |
4818 | -- do not try to fold, this prevents cascaded errors. | |
4819 | ||
4820 | if Etype (Op1) = Any_Type or else Etype (Op2) = Any_Type then | |
4821 | Set_Etype (N, Any_Type); | |
996ae0b0 RK |
4822 | return; |
4823 | ||
4824 | -- If left operand raises constraint error, then replace node N with | |
4825 | -- the raise constraint error node, and we are obviously not foldable. | |
4826 | -- Is_Static_Expression is set from the two operands in the normal way, | |
4827 | -- and we check the right operand if it is in a non-static context. | |
4828 | ||
4829 | elsif Raises_Constraint_Error (Op1) then | |
4830 | if not Rstat then | |
4831 | Check_Non_Static_Context (Op2); | |
4832 | end if; | |
4833 | ||
4834 | Rewrite_In_Raise_CE (N, Op1); | |
4835 | Set_Is_Static_Expression (N, Rstat); | |
996ae0b0 RK |
4836 | return; |
4837 | ||
4838 | -- Similar processing for the case of the right operand. Note that | |
4839 | -- we don't use this routine for the short-circuit case, so we do | |
4840 | -- not have to worry about that special case here. | |
4841 | ||
4842 | elsif Raises_Constraint_Error (Op2) then | |
4843 | if not Rstat then | |
4844 | Check_Non_Static_Context (Op1); | |
4845 | end if; | |
4846 | ||
4847 | Rewrite_In_Raise_CE (N, Op2); | |
4848 | Set_Is_Static_Expression (N, Rstat); | |
996ae0b0 RK |
4849 | return; |
4850 | ||
82c80734 | 4851 | -- Exclude expressions of a generic modular type, as above |
996ae0b0 RK |
4852 | |
4853 | elsif Is_Modular_Integer_Type (Etype (Op1)) | |
4854 | and then Is_Generic_Type (Etype (Op1)) | |
4855 | then | |
4856 | Check_Non_Static_Context (Op1); | |
996ae0b0 RK |
4857 | return; |
4858 | ||
4859 | -- If result is not static, then check non-static contexts on operands | |
4860 | -- since one of them may be static and the other one may not be static | |
4861 | ||
4862 | elsif not Rstat then | |
4863 | Check_Non_Static_Context (Op1); | |
4864 | Check_Non_Static_Context (Op2); | |
4865 | Fold := Compile_Time_Known_Value (Op1) | |
4866 | and then Compile_Time_Known_Value (Op2); | |
4867 | return; | |
4868 | ||
4869 | -- Else result is static and foldable. Both operands are static, | |
4870 | -- and neither raises constraint error, so we can definitely fold. | |
4871 | ||
4872 | else | |
4873 | Set_Is_Static_Expression (N); | |
4874 | Fold := True; | |
4875 | Stat := True; | |
4876 | return; | |
4877 | end if; | |
4878 | end Test_Expression_Is_Foldable; | |
4879 | ||
4880 | -------------- | |
4881 | -- To_Bits -- | |
4882 | -------------- | |
4883 | ||
4884 | procedure To_Bits (U : Uint; B : out Bits) is | |
4885 | begin | |
4886 | for J in 0 .. B'Last loop | |
4887 | B (J) := (U / (2 ** J)) mod 2 /= 0; | |
4888 | end loop; | |
4889 | end To_Bits; | |
4890 | ||
fbf5a39b AC |
4891 | -------------------- |
4892 | -- Why_Not_Static -- | |
4893 | -------------------- | |
4894 | ||
4895 | procedure Why_Not_Static (Expr : Node_Id) is | |
4896 | N : constant Node_Id := Original_Node (Expr); | |
4897 | Typ : Entity_Id; | |
4898 | E : Entity_Id; | |
4899 | ||
4900 | procedure Why_Not_Static_List (L : List_Id); | |
4901 | -- A version that can be called on a list of expressions. Finds | |
4902 | -- all non-static violations in any element of the list. | |
4903 | ||
4904 | ------------------------- | |
4905 | -- Why_Not_Static_List -- | |
4906 | ------------------------- | |
4907 | ||
4908 | procedure Why_Not_Static_List (L : List_Id) is | |
4909 | N : Node_Id; | |
4910 | ||
4911 | begin | |
4912 | if Is_Non_Empty_List (L) then | |
4913 | N := First (L); | |
4914 | while Present (N) loop | |
4915 | Why_Not_Static (N); | |
4916 | Next (N); | |
4917 | end loop; | |
4918 | end if; | |
4919 | end Why_Not_Static_List; | |
4920 | ||
4921 | -- Start of processing for Why_Not_Static | |
4922 | ||
4923 | begin | |
4924 | -- If in ACATS mode (debug flag 2), then suppress all these | |
4925 | -- messages, this avoids massive updates to the ACATS base line. | |
4926 | ||
4927 | if Debug_Flag_2 then | |
4928 | return; | |
4929 | end if; | |
4930 | ||
4931 | -- Ignore call on error or empty node | |
4932 | ||
4933 | if No (Expr) or else Nkind (Expr) = N_Error then | |
4934 | return; | |
4935 | end if; | |
4936 | ||
4937 | -- Preprocessing for sub expressions | |
4938 | ||
4939 | if Nkind (Expr) in N_Subexpr then | |
4940 | ||
4941 | -- Nothing to do if expression is static | |
4942 | ||
4943 | if Is_OK_Static_Expression (Expr) then | |
4944 | return; | |
4945 | end if; | |
4946 | ||
4947 | -- Test for constraint error raised | |
4948 | ||
4949 | if Raises_Constraint_Error (Expr) then | |
4950 | Error_Msg_N | |
4951 | ("expression raises exception, cannot be static " & | |
b11e8d6f | 4952 | "(RM 4.9(34))!", N); |
fbf5a39b AC |
4953 | return; |
4954 | end if; | |
4955 | ||
4956 | -- If no type, then something is pretty wrong, so ignore | |
4957 | ||
4958 | Typ := Etype (Expr); | |
4959 | ||
4960 | if No (Typ) then | |
4961 | return; | |
4962 | end if; | |
4963 | ||
4964 | -- Type must be scalar or string type | |
4965 | ||
4966 | if not Is_Scalar_Type (Typ) | |
4967 | and then not Is_String_Type (Typ) | |
4968 | then | |
4969 | Error_Msg_N | |
4970 | ("static expression must have scalar or string type " & | |
b11e8d6f | 4971 | "(RM 4.9(2))!", N); |
fbf5a39b AC |
4972 | return; |
4973 | end if; | |
4974 | end if; | |
4975 | ||
4976 | -- If we got through those checks, test particular node kind | |
4977 | ||
4978 | case Nkind (N) is | |
4979 | when N_Expanded_Name | N_Identifier | N_Operator_Symbol => | |
4980 | E := Entity (N); | |
4981 | ||
4982 | if Is_Named_Number (E) then | |
4983 | null; | |
4984 | ||
4985 | elsif Ekind (E) = E_Constant then | |
4986 | if not Is_Static_Expression (Constant_Value (E)) then | |
4987 | Error_Msg_NE | |
b11e8d6f | 4988 | ("& is not a static constant (RM 4.9(5))!", N, E); |
fbf5a39b AC |
4989 | end if; |
4990 | ||
4991 | else | |
4992 | Error_Msg_NE | |
4993 | ("& is not static constant or named number " & | |
b11e8d6f | 4994 | "(RM 4.9(5))!", N, E); |
fbf5a39b AC |
4995 | end if; |
4996 | ||
514d0fc5 | 4997 | when N_Binary_Op | N_Short_Circuit | N_Membership_Test => |
fbf5a39b AC |
4998 | if Nkind (N) in N_Op_Shift then |
4999 | Error_Msg_N | |
b11e8d6f | 5000 | ("shift functions are never static (RM 4.9(6,18))!", N); |
fbf5a39b AC |
5001 | |
5002 | else | |
5003 | Why_Not_Static (Left_Opnd (N)); | |
5004 | Why_Not_Static (Right_Opnd (N)); | |
5005 | end if; | |
5006 | ||
5007 | when N_Unary_Op => | |
5008 | Why_Not_Static (Right_Opnd (N)); | |
5009 | ||
5010 | when N_Attribute_Reference => | |
5011 | Why_Not_Static_List (Expressions (N)); | |
5012 | ||
5013 | E := Etype (Prefix (N)); | |
5014 | ||
5015 | if E = Standard_Void_Type then | |
5016 | return; | |
5017 | end if; | |
5018 | ||
5019 | -- Special case non-scalar'Size since this is a common error | |
5020 | ||
5021 | if Attribute_Name (N) = Name_Size then | |
5022 | Error_Msg_N | |
fdfea49e | 5023 | ("size attribute is only static for static scalar type " & |
b11e8d6f | 5024 | "(RM 4.9(7,8))", N); |
fbf5a39b AC |
5025 | |
5026 | -- Flag array cases | |
5027 | ||
5028 | elsif Is_Array_Type (E) then | |
5029 | if Attribute_Name (N) /= Name_First | |
5030 | and then | |
5031 | Attribute_Name (N) /= Name_Last | |
5032 | and then | |
5033 | Attribute_Name (N) /= Name_Length | |
5034 | then | |
5035 | Error_Msg_N | |
5036 | ("static array attribute must be Length, First, or Last " & | |
b11e8d6f | 5037 | "(RM 4.9(8))!", N); |
fbf5a39b AC |
5038 | |
5039 | -- Since we know the expression is not-static (we already | |
5040 | -- tested for this, must mean array is not static). | |
5041 | ||
5042 | else | |
5043 | Error_Msg_N | |
b11e8d6f | 5044 | ("prefix is non-static array (RM 4.9(8))!", Prefix (N)); |
fbf5a39b AC |
5045 | end if; |
5046 | ||
5047 | return; | |
5048 | ||
5049 | -- Special case generic types, since again this is a common | |
5050 | -- source of confusion. | |
5051 | ||
5052 | elsif Is_Generic_Actual_Type (E) | |
5053 | or else | |
5054 | Is_Generic_Type (E) | |
5055 | then | |
5056 | Error_Msg_N | |
5057 | ("attribute of generic type is never static " & | |
b11e8d6f | 5058 | "(RM 4.9(7,8))!", N); |
fbf5a39b AC |
5059 | |
5060 | elsif Is_Static_Subtype (E) then | |
5061 | null; | |
5062 | ||
5063 | elsif Is_Scalar_Type (E) then | |
5064 | Error_Msg_N | |
5065 | ("prefix type for attribute is not static scalar subtype " & | |
b11e8d6f | 5066 | "(RM 4.9(7))!", N); |
fbf5a39b AC |
5067 | |
5068 | else | |
5069 | Error_Msg_N | |
5070 | ("static attribute must apply to array/scalar type " & | |
b11e8d6f | 5071 | "(RM 4.9(7,8))!", N); |
fbf5a39b AC |
5072 | end if; |
5073 | ||
5074 | when N_String_Literal => | |
5075 | Error_Msg_N | |
b11e8d6f | 5076 | ("subtype of string literal is non-static (RM 4.9(4))!", N); |
fbf5a39b AC |
5077 | |
5078 | when N_Explicit_Dereference => | |
5079 | Error_Msg_N | |
b11e8d6f | 5080 | ("explicit dereference is never static (RM 4.9)!", N); |
fbf5a39b AC |
5081 | |
5082 | when N_Function_Call => | |
5083 | Why_Not_Static_List (Parameter_Associations (N)); | |
b11e8d6f | 5084 | Error_Msg_N ("non-static function call (RM 4.9(6,18))!", N); |
fbf5a39b AC |
5085 | |
5086 | when N_Parameter_Association => | |
5087 | Why_Not_Static (Explicit_Actual_Parameter (N)); | |
5088 | ||
5089 | when N_Indexed_Component => | |
5090 | Error_Msg_N | |
b11e8d6f | 5091 | ("indexed component is never static (RM 4.9)!", N); |
fbf5a39b AC |
5092 | |
5093 | when N_Procedure_Call_Statement => | |
5094 | Error_Msg_N | |
b11e8d6f | 5095 | ("procedure call is never static (RM 4.9)!", N); |
fbf5a39b AC |
5096 | |
5097 | when N_Qualified_Expression => | |
5098 | Why_Not_Static (Expression (N)); | |
5099 | ||
5100 | when N_Aggregate | N_Extension_Aggregate => | |
5101 | Error_Msg_N | |
b11e8d6f | 5102 | ("an aggregate is never static (RM 4.9)!", N); |
fbf5a39b AC |
5103 | |
5104 | when N_Range => | |
5105 | Why_Not_Static (Low_Bound (N)); | |
5106 | Why_Not_Static (High_Bound (N)); | |
5107 | ||
5108 | when N_Range_Constraint => | |
5109 | Why_Not_Static (Range_Expression (N)); | |
5110 | ||
5111 | when N_Subtype_Indication => | |
5112 | Why_Not_Static (Constraint (N)); | |
5113 | ||
5114 | when N_Selected_Component => | |
5115 | Error_Msg_N | |
b11e8d6f | 5116 | ("selected component is never static (RM 4.9)!", N); |
fbf5a39b AC |
5117 | |
5118 | when N_Slice => | |
5119 | Error_Msg_N | |
b11e8d6f | 5120 | ("slice is never static (RM 4.9)!", N); |
fbf5a39b AC |
5121 | |
5122 | when N_Type_Conversion => | |
5123 | Why_Not_Static (Expression (N)); | |
5124 | ||
5125 | if not Is_Scalar_Type (Etype (Prefix (N))) | |
5126 | or else not Is_Static_Subtype (Etype (Prefix (N))) | |
5127 | then | |
5128 | Error_Msg_N | |
5129 | ("static conversion requires static scalar subtype result " & | |
b11e8d6f | 5130 | "(RM 4.9(9))!", N); |
fbf5a39b AC |
5131 | end if; |
5132 | ||
5133 | when N_Unchecked_Type_Conversion => | |
5134 | Error_Msg_N | |
b11e8d6f | 5135 | ("unchecked type conversion is never static (RM 4.9)!", N); |
fbf5a39b AC |
5136 | |
5137 | when others => | |
5138 | null; | |
5139 | ||
5140 | end case; | |
5141 | end Why_Not_Static; | |
5142 | ||
996ae0b0 | 5143 | end Sem_Eval; |