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Commit | Line | Data |
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13f649f6 JM |
1 | /* Perform -*- C++ -*- constant expression evaluation, including calls to |
2 | constexpr functions. These routines are used both during actual parsing | |
2d76680f PC |
3 | and during the instantiation of template functions. |
4 | ||
a5544970 | 5 | Copyright (C) 1998-2019 Free Software Foundation, Inc. |
2d76680f PC |
6 | |
7 | This file is part of GCC. | |
8 | ||
9 | GCC is free software; you can redistribute it and/or modify it | |
10 | under the terms of the GNU General Public License as published by | |
11 | the Free Software Foundation; either version 3, or (at your option) | |
12 | any later version. | |
13 | ||
14 | GCC is distributed in the hope that it will be useful, but | |
15 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
17 | General Public License for more details. | |
18 | ||
19 | You should have received a copy of the GNU General Public License | |
20 | along with GCC; see the file COPYING3. If not see | |
21 | <http://www.gnu.org/licenses/>. */ | |
22 | ||
23 | #include "config.h" | |
24 | #include "system.h" | |
25 | #include "coretypes.h" | |
2d76680f | 26 | #include "cp-tree.h" |
2adfab87 | 27 | #include "varasm.h" |
2d76680f PC |
28 | #include "c-family/c-objc.h" |
29 | #include "tree-iterator.h" | |
30 | #include "gimplify.h" | |
31 | #include "builtins.h" | |
60813a46 | 32 | #include "tree-inline.h" |
0b274c17 | 33 | #include "ubsan.h" |
44a845ca | 34 | #include "gimple-fold.h" |
8108ea30 | 35 | #include "timevar.h" |
d8fcab68 | 36 | #include "fold-const-call.h" |
2d76680f PC |
37 | |
38 | static bool verify_constant (tree, bool, bool *, bool *); | |
39 | #define VERIFY_CONSTANT(X) \ | |
40 | do { \ | |
2b3ab879 | 41 | if (verify_constant ((X), ctx->quiet, non_constant_p, overflow_p)) \ |
2d76680f PC |
42 | return t; \ |
43 | } while (0) | |
44 | ||
582d2481 JJ |
45 | static HOST_WIDE_INT find_array_ctor_elt (tree ary, tree dindex, |
46 | bool insert = false); | |
47 | ||
2d76680f PC |
48 | /* Returns true iff FUN is an instantiation of a constexpr function |
49 | template or a defaulted constexpr function. */ | |
50 | ||
51 | bool | |
52 | is_instantiation_of_constexpr (tree fun) | |
53 | { | |
54 | return ((DECL_TEMPLOID_INSTANTIATION (fun) | |
55 | && DECL_DECLARED_CONSTEXPR_P (DECL_TI_TEMPLATE (fun))) | |
56 | || (DECL_DEFAULTED_FN (fun) | |
57 | && DECL_DECLARED_CONSTEXPR_P (fun))); | |
58 | } | |
59 | ||
60 | /* Return true if T is a literal type. */ | |
61 | ||
62 | bool | |
63 | literal_type_p (tree t) | |
64 | { | |
65 | if (SCALAR_TYPE_P (t) | |
b55b02ea | 66 | || VECTOR_TYPE_P (t) |
9f613f06 | 67 | || TYPE_REF_P (t) |
e42c407c | 68 | || (VOID_TYPE_P (t) && cxx_dialect >= cxx14)) |
2d76680f PC |
69 | return true; |
70 | if (CLASS_TYPE_P (t)) | |
71 | { | |
72 | t = complete_type (t); | |
73 | gcc_assert (COMPLETE_TYPE_P (t) || errorcount); | |
74 | return CLASSTYPE_LITERAL_P (t); | |
75 | } | |
76 | if (TREE_CODE (t) == ARRAY_TYPE) | |
77 | return literal_type_p (strip_array_types (t)); | |
78 | return false; | |
79 | } | |
80 | ||
81 | /* If DECL is a variable declared `constexpr', require its type | |
9638f320 PC |
82 | be literal. Return error_mark_node if we give an error, the |
83 | DECL otherwise. */ | |
2d76680f PC |
84 | |
85 | tree | |
86 | ensure_literal_type_for_constexpr_object (tree decl) | |
87 | { | |
88 | tree type = TREE_TYPE (decl); | |
89 | if (VAR_P (decl) | |
90 | && (DECL_DECLARED_CONSTEXPR_P (decl) | |
91 | || var_in_constexpr_fn (decl)) | |
92 | && !processing_template_decl) | |
93 | { | |
94 | tree stype = strip_array_types (type); | |
95 | if (CLASS_TYPE_P (stype) && !COMPLETE_TYPE_P (complete_type (stype))) | |
96 | /* Don't complain here, we'll complain about incompleteness | |
97 | when we try to initialize the variable. */; | |
683be2f7 JM |
98 | else if (type_uses_auto (type)) |
99 | /* We don't know the actual type yet. */; | |
2d76680f PC |
100 | else if (!literal_type_p (type)) |
101 | { | |
102 | if (DECL_DECLARED_CONSTEXPR_P (decl)) | |
f1eac182 | 103 | { |
097f82ec | 104 | auto_diagnostic_group d; |
f2935576 PC |
105 | error_at (DECL_SOURCE_LOCATION (decl), |
106 | "the type %qT of %<constexpr%> variable %qD " | |
107 | "is not literal", type, decl); | |
f1eac182 | 108 | explain_non_literal_class (type); |
9638f320 | 109 | decl = error_mark_node; |
f1eac182 | 110 | } |
2d76680f | 111 | else |
60813a46 | 112 | { |
5d4e573b | 113 | if (!is_instantiation_of_constexpr (current_function_decl)) |
f1eac182 | 114 | { |
097f82ec | 115 | auto_diagnostic_group d; |
f2935576 PC |
116 | error_at (DECL_SOURCE_LOCATION (decl), |
117 | "variable %qD of non-literal type %qT in " | |
118 | "%<constexpr%> function", decl, type); | |
f1eac182 | 119 | explain_non_literal_class (type); |
9638f320 | 120 | decl = error_mark_node; |
f1eac182 | 121 | } |
60813a46 JM |
122 | cp_function_chain->invalid_constexpr = true; |
123 | } | |
2d76680f | 124 | } |
8e9589bd JM |
125 | else if (DECL_DECLARED_CONSTEXPR_P (decl) |
126 | && variably_modified_type_p (type, NULL_TREE)) | |
127 | { | |
f2935576 PC |
128 | error_at (DECL_SOURCE_LOCATION (decl), |
129 | "%<constexpr%> variable %qD has variably-modified " | |
130 | "type %qT", decl, type); | |
8e9589bd JM |
131 | decl = error_mark_node; |
132 | } | |
2d76680f PC |
133 | } |
134 | return decl; | |
135 | } | |
136 | ||
137 | /* Representation of entries in the constexpr function definition table. */ | |
138 | ||
139 | struct GTY((for_user)) constexpr_fundef { | |
140 | tree decl; | |
141 | tree body; | |
43574e4f JJ |
142 | tree parms; |
143 | tree result; | |
2d76680f PC |
144 | }; |
145 | ||
ca752f39 | 146 | struct constexpr_fundef_hasher : ggc_ptr_hash<constexpr_fundef> |
2d76680f PC |
147 | { |
148 | static hashval_t hash (constexpr_fundef *); | |
149 | static bool equal (constexpr_fundef *, constexpr_fundef *); | |
150 | }; | |
151 | ||
152 | /* This table holds all constexpr function definitions seen in | |
153 | the current translation unit. */ | |
154 | ||
155 | static GTY (()) hash_table<constexpr_fundef_hasher> *constexpr_fundef_table; | |
156 | ||
157 | /* Utility function used for managing the constexpr function table. | |
158 | Return true if the entries pointed to by P and Q are for the | |
159 | same constexpr function. */ | |
160 | ||
161 | inline bool | |
162 | constexpr_fundef_hasher::equal (constexpr_fundef *lhs, constexpr_fundef *rhs) | |
163 | { | |
164 | return lhs->decl == rhs->decl; | |
165 | } | |
166 | ||
167 | /* Utility function used for managing the constexpr function table. | |
168 | Return a hash value for the entry pointed to by Q. */ | |
169 | ||
170 | inline hashval_t | |
171 | constexpr_fundef_hasher::hash (constexpr_fundef *fundef) | |
172 | { | |
173 | return DECL_UID (fundef->decl); | |
174 | } | |
175 | ||
176 | /* Return a previously saved definition of function FUN. */ | |
177 | ||
178 | static constexpr_fundef * | |
179 | retrieve_constexpr_fundef (tree fun) | |
180 | { | |
2d76680f PC |
181 | if (constexpr_fundef_table == NULL) |
182 | return NULL; | |
183 | ||
43574e4f | 184 | constexpr_fundef fundef = { fun, NULL, NULL, NULL }; |
2d76680f PC |
185 | return constexpr_fundef_table->find (&fundef); |
186 | } | |
187 | ||
188 | /* Check whether the parameter and return types of FUN are valid for a | |
189 | constexpr function, and complain if COMPLAIN. */ | |
190 | ||
98e5a19a | 191 | bool |
2d76680f PC |
192 | is_valid_constexpr_fn (tree fun, bool complain) |
193 | { | |
194 | bool ret = true; | |
195 | ||
31f7f784 | 196 | if (DECL_INHERITED_CTOR (fun) |
2d76680f PC |
197 | && TREE_CODE (fun) == TEMPLATE_DECL) |
198 | { | |
199 | ret = false; | |
200 | if (complain) | |
84fa214d | 201 | error ("inherited constructor %qD is not %<constexpr%>", |
31f7f784 | 202 | DECL_INHERITED_CTOR (fun)); |
2d76680f PC |
203 | } |
204 | else | |
205 | { | |
206 | for (tree parm = FUNCTION_FIRST_USER_PARM (fun); | |
207 | parm != NULL_TREE; parm = TREE_CHAIN (parm)) | |
208 | if (!literal_type_p (TREE_TYPE (parm))) | |
209 | { | |
210 | ret = false; | |
211 | if (complain) | |
212 | { | |
097f82ec | 213 | auto_diagnostic_group d; |
84fa214d | 214 | error ("invalid type for parameter %d of %<constexpr%> " |
2d76680f PC |
215 | "function %q+#D", DECL_PARM_INDEX (parm), fun); |
216 | explain_non_literal_class (TREE_TYPE (parm)); | |
217 | } | |
218 | } | |
219 | } | |
220 | ||
e1bea341 JM |
221 | if (LAMBDA_TYPE_P (CP_DECL_CONTEXT (fun)) && cxx_dialect < cxx17) |
222 | { | |
223 | ret = false; | |
224 | if (complain) | |
225 | inform (DECL_SOURCE_LOCATION (fun), | |
84fa214d | 226 | "lambdas are implicitly %<constexpr%> only in C++17 and later"); |
e1bea341 JM |
227 | } |
228 | else if (!DECL_CONSTRUCTOR_P (fun)) | |
2d76680f PC |
229 | { |
230 | tree rettype = TREE_TYPE (TREE_TYPE (fun)); | |
231 | if (!literal_type_p (rettype)) | |
232 | { | |
233 | ret = false; | |
234 | if (complain) | |
235 | { | |
097f82ec | 236 | auto_diagnostic_group d; |
84fa214d | 237 | error ("invalid return type %qT of %<constexpr%> function %q+D", |
2d76680f PC |
238 | rettype, fun); |
239 | explain_non_literal_class (rettype); | |
240 | } | |
241 | } | |
242 | ||
54069e59 JM |
243 | /* C++14 DR 1684 removed this restriction. */ |
244 | if (cxx_dialect < cxx14 | |
245 | && DECL_NONSTATIC_MEMBER_FUNCTION_P (fun) | |
2d76680f PC |
246 | && !CLASSTYPE_LITERAL_P (DECL_CONTEXT (fun))) |
247 | { | |
248 | ret = false; | |
097f82ec DM |
249 | if (complain) |
250 | { | |
251 | auto_diagnostic_group d; | |
252 | if (pedwarn (DECL_SOURCE_LOCATION (fun), OPT_Wpedantic, | |
253 | "enclosing class of %<constexpr%> non-static" | |
254 | " member function %q+#D is not a literal type", | |
255 | fun)) | |
256 | explain_non_literal_class (DECL_CONTEXT (fun)); | |
257 | } | |
2d76680f PC |
258 | } |
259 | } | |
260 | else if (CLASSTYPE_VBASECLASSES (DECL_CONTEXT (fun))) | |
261 | { | |
262 | ret = false; | |
263 | if (complain) | |
264 | error ("%q#T has virtual base classes", DECL_CONTEXT (fun)); | |
265 | } | |
266 | ||
267 | return ret; | |
268 | } | |
269 | ||
270 | /* Subroutine of build_data_member_initialization. MEMBER is a COMPONENT_REF | |
271 | for a member of an anonymous aggregate, INIT is the initializer for that | |
272 | member, and VEC_OUTER is the vector of constructor elements for the class | |
273 | whose constructor we are processing. Add the initializer to the vector | |
274 | and return true to indicate success. */ | |
275 | ||
276 | static bool | |
277 | build_anon_member_initialization (tree member, tree init, | |
278 | vec<constructor_elt, va_gc> **vec_outer) | |
279 | { | |
280 | /* MEMBER presents the relevant fields from the inside out, but we need | |
281 | to build up the initializer from the outside in so that we can reuse | |
282 | previously built CONSTRUCTORs if this is, say, the second field in an | |
283 | anonymous struct. So we use a vec as a stack. */ | |
284 | auto_vec<tree, 2> fields; | |
285 | do | |
286 | { | |
287 | fields.safe_push (TREE_OPERAND (member, 1)); | |
288 | member = TREE_OPERAND (member, 0); | |
289 | } | |
290 | while (ANON_AGGR_TYPE_P (TREE_TYPE (member)) | |
291 | && TREE_CODE (member) == COMPONENT_REF); | |
292 | ||
293 | /* VEC has the constructor elements vector for the context of FIELD. | |
294 | If FIELD is an anonymous aggregate, we will push inside it. */ | |
295 | vec<constructor_elt, va_gc> **vec = vec_outer; | |
296 | tree field; | |
297 | while (field = fields.pop(), | |
298 | ANON_AGGR_TYPE_P (TREE_TYPE (field))) | |
299 | { | |
300 | tree ctor; | |
301 | /* If there is already an outer constructor entry for the anonymous | |
302 | aggregate FIELD, use it; otherwise, insert one. */ | |
303 | if (vec_safe_is_empty (*vec) | |
304 | || (*vec)->last().index != field) | |
305 | { | |
306 | ctor = build_constructor (TREE_TYPE (field), NULL); | |
307 | CONSTRUCTOR_APPEND_ELT (*vec, field, ctor); | |
308 | } | |
309 | else | |
310 | ctor = (*vec)->last().value; | |
311 | vec = &CONSTRUCTOR_ELTS (ctor); | |
312 | } | |
313 | ||
314 | /* Now we're at the innermost field, the one that isn't an anonymous | |
315 | aggregate. Add its initializer to the CONSTRUCTOR and we're done. */ | |
316 | gcc_assert (fields.is_empty()); | |
317 | CONSTRUCTOR_APPEND_ELT (*vec, field, init); | |
318 | ||
319 | return true; | |
320 | } | |
321 | ||
322 | /* Subroutine of build_constexpr_constructor_member_initializers. | |
323 | The expression tree T represents a data member initialization | |
324 | in a (constexpr) constructor definition. Build a pairing of | |
325 | the data member with its initializer, and prepend that pair | |
326 | to the existing initialization pair INITS. */ | |
327 | ||
328 | static bool | |
329 | build_data_member_initialization (tree t, vec<constructor_elt, va_gc> **vec) | |
330 | { | |
331 | tree member, init; | |
332 | if (TREE_CODE (t) == CLEANUP_POINT_EXPR) | |
333 | t = TREE_OPERAND (t, 0); | |
334 | if (TREE_CODE (t) == EXPR_STMT) | |
335 | t = TREE_OPERAND (t, 0); | |
336 | if (t == error_mark_node) | |
337 | return false; | |
338 | if (TREE_CODE (t) == STATEMENT_LIST) | |
339 | { | |
340 | tree_stmt_iterator i; | |
341 | for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i)) | |
342 | { | |
343 | if (! build_data_member_initialization (tsi_stmt (i), vec)) | |
344 | return false; | |
345 | } | |
346 | return true; | |
347 | } | |
348 | if (TREE_CODE (t) == CLEANUP_STMT) | |
349 | { | |
350 | /* We can't see a CLEANUP_STMT in a constructor for a literal class, | |
351 | but we can in a constexpr constructor for a non-literal class. Just | |
352 | ignore it; either all the initialization will be constant, in which | |
353 | case the cleanup can't run, or it can't be constexpr. | |
354 | Still recurse into CLEANUP_BODY. */ | |
355 | return build_data_member_initialization (CLEANUP_BODY (t), vec); | |
356 | } | |
357 | if (TREE_CODE (t) == CONVERT_EXPR) | |
358 | t = TREE_OPERAND (t, 0); | |
359 | if (TREE_CODE (t) == INIT_EXPR | |
60813a46 JM |
360 | /* vptr initialization shows up as a MODIFY_EXPR. In C++14 we only |
361 | use what this function builds for cx_check_missing_mem_inits, and | |
362 | assignment in the ctor body doesn't count. */ | |
363 | || (cxx_dialect < cxx14 && TREE_CODE (t) == MODIFY_EXPR)) | |
2d76680f PC |
364 | { |
365 | member = TREE_OPERAND (t, 0); | |
366 | init = break_out_target_exprs (TREE_OPERAND (t, 1)); | |
367 | } | |
368 | else if (TREE_CODE (t) == CALL_EXPR) | |
369 | { | |
60813a46 JM |
370 | tree fn = get_callee_fndecl (t); |
371 | if (!fn || !DECL_CONSTRUCTOR_P (fn)) | |
372 | /* We're only interested in calls to subobject constructors. */ | |
373 | return true; | |
2d76680f PC |
374 | member = CALL_EXPR_ARG (t, 0); |
375 | /* We don't use build_cplus_new here because it complains about | |
376 | abstract bases. Leaving the call unwrapped means that it has the | |
377 | wrong type, but cxx_eval_constant_expression doesn't care. */ | |
378 | init = break_out_target_exprs (t); | |
379 | } | |
380 | else if (TREE_CODE (t) == BIND_EXPR) | |
381 | return build_data_member_initialization (BIND_EXPR_BODY (t), vec); | |
2d76680f | 382 | else |
60813a46 JM |
383 | /* Don't add anything else to the CONSTRUCTOR. */ |
384 | return true; | |
2d76680f PC |
385 | if (INDIRECT_REF_P (member)) |
386 | member = TREE_OPERAND (member, 0); | |
387 | if (TREE_CODE (member) == NOP_EXPR) | |
388 | { | |
389 | tree op = member; | |
390 | STRIP_NOPS (op); | |
391 | if (TREE_CODE (op) == ADDR_EXPR) | |
392 | { | |
393 | gcc_assert (same_type_ignoring_top_level_qualifiers_p | |
394 | (TREE_TYPE (TREE_TYPE (op)), | |
395 | TREE_TYPE (TREE_TYPE (member)))); | |
396 | /* Initializing a cv-qualified member; we need to look through | |
397 | the const_cast. */ | |
398 | member = op; | |
399 | } | |
400 | else if (op == current_class_ptr | |
401 | && (same_type_ignoring_top_level_qualifiers_p | |
402 | (TREE_TYPE (TREE_TYPE (member)), | |
403 | current_class_type))) | |
404 | /* Delegating constructor. */ | |
405 | member = op; | |
406 | else | |
407 | { | |
408 | /* This is an initializer for an empty base; keep it for now so | |
409 | we can check it in cxx_eval_bare_aggregate. */ | |
410 | gcc_assert (is_empty_class (TREE_TYPE (TREE_TYPE (member)))); | |
411 | } | |
412 | } | |
413 | if (TREE_CODE (member) == ADDR_EXPR) | |
414 | member = TREE_OPERAND (member, 0); | |
415 | if (TREE_CODE (member) == COMPONENT_REF) | |
416 | { | |
417 | tree aggr = TREE_OPERAND (member, 0); | |
8cb7aaa1 JM |
418 | if (TREE_CODE (aggr) == VAR_DECL) |
419 | /* Initializing a local variable, don't add anything. */ | |
420 | return true; | |
2d76680f PC |
421 | if (TREE_CODE (aggr) != COMPONENT_REF) |
422 | /* Normal member initialization. */ | |
423 | member = TREE_OPERAND (member, 1); | |
424 | else if (ANON_AGGR_TYPE_P (TREE_TYPE (aggr))) | |
425 | /* Initializing a member of an anonymous union. */ | |
426 | return build_anon_member_initialization (member, init, vec); | |
427 | else | |
428 | /* We're initializing a vtable pointer in a base. Leave it as | |
429 | COMPONENT_REF so we remember the path to get to the vfield. */ | |
430 | gcc_assert (TREE_TYPE (member) == vtbl_ptr_type_node); | |
431 | } | |
432 | ||
49b5925f JM |
433 | /* Value-initialization can produce multiple initializers for the |
434 | same field; use the last one. */ | |
435 | if (!vec_safe_is_empty (*vec) && (*vec)->last().index == member) | |
436 | (*vec)->last().value = init; | |
437 | else | |
438 | CONSTRUCTOR_APPEND_ELT (*vec, member, init); | |
2d76680f PC |
439 | return true; |
440 | } | |
441 | ||
442 | /* Subroutine of check_constexpr_ctor_body_1 and constexpr_fn_retval. | |
443 | In C++11 mode checks that the TYPE_DECLs in the BIND_EXPR_VARS of a | |
444 | BIND_EXPR conform to 7.1.5/3/4 on typedef and alias declarations. */ | |
445 | ||
446 | static bool | |
447 | check_constexpr_bind_expr_vars (tree t) | |
448 | { | |
449 | gcc_assert (TREE_CODE (t) == BIND_EXPR); | |
450 | ||
2d76680f PC |
451 | for (tree var = BIND_EXPR_VARS (t); var; var = DECL_CHAIN (var)) |
452 | if (TREE_CODE (var) == TYPE_DECL | |
4414e22e PC |
453 | && DECL_IMPLICIT_TYPEDEF_P (var) |
454 | && !LAMBDA_TYPE_P (TREE_TYPE (var))) | |
2d76680f PC |
455 | return false; |
456 | return true; | |
457 | } | |
458 | ||
459 | /* Subroutine of check_constexpr_ctor_body. */ | |
460 | ||
461 | static bool | |
462 | check_constexpr_ctor_body_1 (tree last, tree list) | |
463 | { | |
464 | switch (TREE_CODE (list)) | |
465 | { | |
466 | case DECL_EXPR: | |
a0008434 MP |
467 | if (TREE_CODE (DECL_EXPR_DECL (list)) == USING_DECL |
468 | || TREE_CODE (DECL_EXPR_DECL (list)) == TYPE_DECL) | |
2d76680f | 469 | return true; |
2d76680f PC |
470 | return false; |
471 | ||
472 | case CLEANUP_POINT_EXPR: | |
473 | return check_constexpr_ctor_body (last, TREE_OPERAND (list, 0), | |
474 | /*complain=*/false); | |
475 | ||
476 | case BIND_EXPR: | |
477 | if (!check_constexpr_bind_expr_vars (list) | |
478 | || !check_constexpr_ctor_body (last, BIND_EXPR_BODY (list), | |
479 | /*complain=*/false)) | |
480 | return false; | |
481 | return true; | |
482 | ||
483 | case USING_STMT: | |
484 | case STATIC_ASSERT: | |
96a95ac1 | 485 | case DEBUG_BEGIN_STMT: |
2d76680f PC |
486 | return true; |
487 | ||
488 | default: | |
489 | return false; | |
490 | } | |
491 | } | |
492 | ||
493 | /* Make sure that there are no statements after LAST in the constructor | |
494 | body represented by LIST. */ | |
495 | ||
496 | bool | |
497 | check_constexpr_ctor_body (tree last, tree list, bool complain) | |
498 | { | |
60813a46 JM |
499 | /* C++14 doesn't require a constexpr ctor to have an empty body. */ |
500 | if (cxx_dialect >= cxx14) | |
501 | return true; | |
502 | ||
2d76680f PC |
503 | bool ok = true; |
504 | if (TREE_CODE (list) == STATEMENT_LIST) | |
505 | { | |
506 | tree_stmt_iterator i = tsi_last (list); | |
507 | for (; !tsi_end_p (i); tsi_prev (&i)) | |
508 | { | |
509 | tree t = tsi_stmt (i); | |
510 | if (t == last) | |
511 | break; | |
512 | if (!check_constexpr_ctor_body_1 (last, t)) | |
513 | { | |
514 | ok = false; | |
515 | break; | |
516 | } | |
517 | } | |
518 | } | |
519 | else if (list != last | |
520 | && !check_constexpr_ctor_body_1 (last, list)) | |
521 | ok = false; | |
522 | if (!ok) | |
523 | { | |
524 | if (complain) | |
84fa214d | 525 | error ("%<constexpr%> constructor does not have empty body"); |
2d76680f PC |
526 | DECL_DECLARED_CONSTEXPR_P (current_function_decl) = false; |
527 | } | |
528 | return ok; | |
529 | } | |
530 | ||
531 | /* V is a vector of constructor elements built up for the base and member | |
532 | initializers of a constructor for TYPE. They need to be in increasing | |
533 | offset order, which they might not be yet if TYPE has a primary base | |
534 | which is not first in the base-clause or a vptr and at least one base | |
535 | all of which are non-primary. */ | |
536 | ||
537 | static vec<constructor_elt, va_gc> * | |
538 | sort_constexpr_mem_initializers (tree type, vec<constructor_elt, va_gc> *v) | |
539 | { | |
540 | tree pri = CLASSTYPE_PRIMARY_BINFO (type); | |
541 | tree field_type; | |
542 | unsigned i; | |
543 | constructor_elt *ce; | |
544 | ||
545 | if (pri) | |
546 | field_type = BINFO_TYPE (pri); | |
547 | else if (TYPE_CONTAINS_VPTR_P (type)) | |
548 | field_type = vtbl_ptr_type_node; | |
549 | else | |
550 | return v; | |
551 | ||
552 | /* Find the element for the primary base or vptr and move it to the | |
553 | beginning of the vec. */ | |
554 | for (i = 0; vec_safe_iterate (v, i, &ce); ++i) | |
555 | if (TREE_TYPE (ce->index) == field_type) | |
556 | break; | |
557 | ||
558 | if (i > 0 && i < vec_safe_length (v)) | |
559 | { | |
560 | vec<constructor_elt, va_gc> &vref = *v; | |
561 | constructor_elt elt = vref[i]; | |
562 | for (; i > 0; --i) | |
563 | vref[i] = vref[i-1]; | |
564 | vref[0] = elt; | |
565 | } | |
566 | ||
567 | return v; | |
568 | } | |
569 | ||
570 | /* Build compile-time evalable representations of member-initializer list | |
571 | for a constexpr constructor. */ | |
572 | ||
573 | static tree | |
574 | build_constexpr_constructor_member_initializers (tree type, tree body) | |
575 | { | |
576 | vec<constructor_elt, va_gc> *vec = NULL; | |
577 | bool ok = true; | |
fa837fb6 JM |
578 | while (true) |
579 | switch (TREE_CODE (body)) | |
580 | { | |
581 | case MUST_NOT_THROW_EXPR: | |
582 | case EH_SPEC_BLOCK: | |
583 | body = TREE_OPERAND (body, 0); | |
584 | break; | |
585 | ||
586 | case STATEMENT_LIST: | |
587 | for (tree_stmt_iterator i = tsi_start (body); | |
588 | !tsi_end_p (i); tsi_next (&i)) | |
589 | { | |
590 | body = tsi_stmt (i); | |
591 | if (TREE_CODE (body) == BIND_EXPR) | |
592 | break; | |
593 | } | |
594 | break; | |
595 | ||
596 | case BIND_EXPR: | |
597 | body = BIND_EXPR_BODY (body); | |
598 | goto found; | |
599 | ||
600 | default: | |
601 | gcc_unreachable (); | |
58cc255c | 602 | } |
fa837fb6 | 603 | found: |
1259cb6d JJ |
604 | if (TREE_CODE (body) == TRY_BLOCK) |
605 | { | |
606 | body = TREE_OPERAND (body, 0); | |
607 | if (TREE_CODE (body) == BIND_EXPR) | |
608 | body = BIND_EXPR_BODY (body); | |
609 | } | |
2d76680f PC |
610 | if (TREE_CODE (body) == CLEANUP_POINT_EXPR) |
611 | { | |
612 | body = TREE_OPERAND (body, 0); | |
613 | if (TREE_CODE (body) == EXPR_STMT) | |
614 | body = TREE_OPERAND (body, 0); | |
615 | if (TREE_CODE (body) == INIT_EXPR | |
616 | && (same_type_ignoring_top_level_qualifiers_p | |
617 | (TREE_TYPE (TREE_OPERAND (body, 0)), | |
618 | current_class_type))) | |
619 | { | |
620 | /* Trivial copy. */ | |
621 | return TREE_OPERAND (body, 1); | |
622 | } | |
623 | ok = build_data_member_initialization (body, &vec); | |
624 | } | |
625 | else if (TREE_CODE (body) == STATEMENT_LIST) | |
626 | { | |
627 | tree_stmt_iterator i; | |
628 | for (i = tsi_start (body); !tsi_end_p (i); tsi_next (&i)) | |
629 | { | |
630 | ok = build_data_member_initialization (tsi_stmt (i), &vec); | |
631 | if (!ok) | |
632 | break; | |
633 | } | |
634 | } | |
2d76680f PC |
635 | else if (EXPR_P (body)) |
636 | ok = build_data_member_initialization (body, &vec); | |
637 | else | |
638 | gcc_assert (errorcount > 0); | |
639 | if (ok) | |
640 | { | |
641 | if (vec_safe_length (vec) > 0) | |
642 | { | |
643 | /* In a delegating constructor, return the target. */ | |
644 | constructor_elt *ce = &(*vec)[0]; | |
645 | if (ce->index == current_class_ptr) | |
646 | { | |
647 | body = ce->value; | |
648 | vec_free (vec); | |
649 | return body; | |
650 | } | |
651 | } | |
652 | vec = sort_constexpr_mem_initializers (type, vec); | |
653 | return build_constructor (type, vec); | |
654 | } | |
655 | else | |
656 | return error_mark_node; | |
657 | } | |
658 | ||
1b6fa695 ML |
659 | /* We have an expression tree T that represents a call, either CALL_EXPR |
660 | or AGGR_INIT_EXPR. If the call is lexically to a named function, | |
661 | retrun the _DECL for that function. */ | |
662 | ||
663 | static tree | |
664 | get_function_named_in_call (tree t) | |
665 | { | |
666 | tree fun = cp_get_callee (t); | |
667 | if (fun && TREE_CODE (fun) == ADDR_EXPR | |
668 | && TREE_CODE (TREE_OPERAND (fun, 0)) == FUNCTION_DECL) | |
669 | fun = TREE_OPERAND (fun, 0); | |
670 | return fun; | |
671 | } | |
672 | ||
2d76680f PC |
673 | /* Subroutine of register_constexpr_fundef. BODY is the body of a function |
674 | declared to be constexpr, or a sub-statement thereof. Returns the | |
675 | return value if suitable, error_mark_node for a statement not allowed in | |
676 | a constexpr function, or NULL_TREE if no return value was found. */ | |
677 | ||
5afef8b1 | 678 | tree |
2d76680f PC |
679 | constexpr_fn_retval (tree body) |
680 | { | |
681 | switch (TREE_CODE (body)) | |
682 | { | |
683 | case STATEMENT_LIST: | |
684 | { | |
685 | tree_stmt_iterator i; | |
686 | tree expr = NULL_TREE; | |
687 | for (i = tsi_start (body); !tsi_end_p (i); tsi_next (&i)) | |
688 | { | |
689 | tree s = constexpr_fn_retval (tsi_stmt (i)); | |
690 | if (s == error_mark_node) | |
691 | return error_mark_node; | |
692 | else if (s == NULL_TREE) | |
693 | /* Keep iterating. */; | |
694 | else if (expr) | |
695 | /* Multiple return statements. */ | |
696 | return error_mark_node; | |
697 | else | |
698 | expr = s; | |
699 | } | |
700 | return expr; | |
701 | } | |
702 | ||
703 | case RETURN_EXPR: | |
704 | return break_out_target_exprs (TREE_OPERAND (body, 0)); | |
705 | ||
706 | case DECL_EXPR: | |
0162cb3b PC |
707 | { |
708 | tree decl = DECL_EXPR_DECL (body); | |
709 | if (TREE_CODE (decl) == USING_DECL | |
710 | /* Accept __func__, __FUNCTION__, and __PRETTY_FUNCTION__. */ | |
711 | || DECL_ARTIFICIAL (decl)) | |
712 | return NULL_TREE; | |
713 | return error_mark_node; | |
714 | } | |
2d76680f PC |
715 | |
716 | case CLEANUP_POINT_EXPR: | |
717 | return constexpr_fn_retval (TREE_OPERAND (body, 0)); | |
718 | ||
719 | case BIND_EXPR: | |
720 | if (!check_constexpr_bind_expr_vars (body)) | |
721 | return error_mark_node; | |
722 | return constexpr_fn_retval (BIND_EXPR_BODY (body)); | |
723 | ||
724 | case USING_STMT: | |
96a95ac1 | 725 | case DEBUG_BEGIN_STMT: |
2d76680f PC |
726 | return NULL_TREE; |
727 | ||
1b6fa695 ML |
728 | case CALL_EXPR: |
729 | { | |
730 | tree fun = get_function_named_in_call (body); | |
731 | if (fun != NULL_TREE | |
3d78e008 | 732 | && fndecl_built_in_p (fun, BUILT_IN_UNREACHABLE)) |
1b6fa695 ML |
733 | return NULL_TREE; |
734 | } | |
735 | /* Fallthru. */ | |
736 | ||
2d76680f PC |
737 | default: |
738 | return error_mark_node; | |
739 | } | |
740 | } | |
741 | ||
742 | /* Subroutine of register_constexpr_fundef. BODY is the DECL_SAVED_TREE of | |
743 | FUN; do the necessary transformations to turn it into a single expression | |
744 | that we can store in the hash table. */ | |
745 | ||
746 | static tree | |
747 | massage_constexpr_body (tree fun, tree body) | |
748 | { | |
749 | if (DECL_CONSTRUCTOR_P (fun)) | |
750 | body = build_constexpr_constructor_member_initializers | |
751 | (DECL_CONTEXT (fun), body); | |
60813a46 | 752 | else if (cxx_dialect < cxx14) |
2d76680f PC |
753 | { |
754 | if (TREE_CODE (body) == EH_SPEC_BLOCK) | |
755 | body = EH_SPEC_STMTS (body); | |
756 | if (TREE_CODE (body) == MUST_NOT_THROW_EXPR) | |
757 | body = TREE_OPERAND (body, 0); | |
758 | body = constexpr_fn_retval (body); | |
759 | } | |
760 | return body; | |
761 | } | |
762 | ||
3e4b91f2 NS |
763 | /* CTYPE is a type constructed from BODY. Return true if some |
764 | bases/fields are uninitialized, and complain if COMPLAIN. */ | |
2d76680f PC |
765 | |
766 | static bool | |
3e4b91f2 | 767 | cx_check_missing_mem_inits (tree ctype, tree body, bool complain) |
2d76680f | 768 | { |
3e4b91f2 NS |
769 | unsigned nelts = 0; |
770 | ||
771 | if (body) | |
772 | { | |
773 | if (TREE_CODE (body) != CONSTRUCTOR) | |
774 | return false; | |
775 | nelts = CONSTRUCTOR_NELTS (body); | |
776 | } | |
777 | tree field = TYPE_FIELDS (ctype); | |
2d76680f PC |
778 | |
779 | if (TREE_CODE (ctype) == UNION_TYPE) | |
780 | { | |
781 | if (nelts == 0 && next_initializable_field (field)) | |
782 | { | |
783 | if (complain) | |
784 | error ("%<constexpr%> constructor for union %qT must " | |
785 | "initialize exactly one non-static data member", ctype); | |
786 | return true; | |
787 | } | |
788 | return false; | |
789 | } | |
790 | ||
3e4b91f2 NS |
791 | /* Iterate over the CONSTRUCTOR, checking any missing fields don't |
792 | need an explicit initialization. */ | |
793 | bool bad = false; | |
794 | for (unsigned i = 0; i <= nelts; ++i) | |
2d76680f | 795 | { |
3e4b91f2 NS |
796 | tree index = NULL_TREE; |
797 | if (i < nelts) | |
2d76680f PC |
798 | { |
799 | index = CONSTRUCTOR_ELT (body, i)->index; | |
800 | /* Skip base and vtable inits. */ | |
801 | if (TREE_CODE (index) != FIELD_DECL | |
802 | || DECL_ARTIFICIAL (index)) | |
803 | continue; | |
804 | } | |
3e4b91f2 | 805 | |
2d76680f PC |
806 | for (; field != index; field = DECL_CHAIN (field)) |
807 | { | |
808 | tree ftype; | |
3e4b91f2 NS |
809 | if (TREE_CODE (field) != FIELD_DECL) |
810 | continue; | |
7c30b12a | 811 | if (DECL_UNNAMED_BIT_FIELD (field)) |
2d76680f | 812 | continue; |
3e4b91f2 NS |
813 | if (DECL_ARTIFICIAL (field)) |
814 | continue; | |
815 | if (ANON_AGGR_TYPE_P (TREE_TYPE (field))) | |
816 | { | |
817 | /* Recurse to check the anonummous aggregate member. */ | |
818 | bad |= cx_check_missing_mem_inits | |
819 | (TREE_TYPE (field), NULL_TREE, complain); | |
820 | if (bad && !complain) | |
821 | return true; | |
822 | continue; | |
823 | } | |
2d76680f PC |
824 | ftype = strip_array_types (TREE_TYPE (field)); |
825 | if (type_has_constexpr_default_constructor (ftype)) | |
826 | { | |
827 | /* It's OK to skip a member with a trivial constexpr ctor. | |
828 | A constexpr ctor that isn't trivial should have been | |
829 | added in by now. */ | |
830 | gcc_checking_assert (!TYPE_HAS_COMPLEX_DFLT (ftype) | |
831 | || errorcount != 0); | |
832 | continue; | |
833 | } | |
834 | if (!complain) | |
835 | return true; | |
097f82ec | 836 | auto_diagnostic_group d; |
b8cd3996 JM |
837 | error ("member %qD must be initialized by mem-initializer " |
838 | "in %<constexpr%> constructor", field); | |
839 | inform (DECL_SOURCE_LOCATION (field), "declared here"); | |
2d76680f PC |
840 | bad = true; |
841 | } | |
842 | if (field == NULL_TREE) | |
843 | break; | |
3e4b91f2 NS |
844 | |
845 | if (ANON_AGGR_TYPE_P (TREE_TYPE (index))) | |
846 | { | |
847 | /* Check the anonymous aggregate initializer is valid. */ | |
848 | bad |= cx_check_missing_mem_inits | |
849 | (TREE_TYPE (index), CONSTRUCTOR_ELT (body, i)->value, complain); | |
850 | if (bad && !complain) | |
851 | return true; | |
852 | } | |
2d76680f PC |
853 | field = DECL_CHAIN (field); |
854 | } | |
855 | ||
856 | return bad; | |
857 | } | |
858 | ||
859 | /* We are processing the definition of the constexpr function FUN. | |
860 | Check that its BODY fulfills the propriate requirements and | |
861 | enter it in the constexpr function definition table. | |
862 | For constructor BODY is actually the TREE_LIST of the | |
863 | member-initializer list. */ | |
864 | ||
865 | tree | |
866 | register_constexpr_fundef (tree fun, tree body) | |
867 | { | |
868 | constexpr_fundef entry; | |
869 | constexpr_fundef **slot; | |
870 | ||
871 | if (!is_valid_constexpr_fn (fun, !DECL_GENERATED_P (fun))) | |
872 | return NULL; | |
873 | ||
ca30abcd JM |
874 | tree massaged = massage_constexpr_body (fun, body); |
875 | if (massaged == NULL_TREE || massaged == error_mark_node) | |
2d76680f PC |
876 | { |
877 | if (!DECL_CONSTRUCTOR_P (fun)) | |
84fa214d ML |
878 | error ("body of %<constexpr%> function %qD not a return-statement", |
879 | fun); | |
2d76680f PC |
880 | return NULL; |
881 | } | |
882 | ||
ca30abcd | 883 | if (!potential_rvalue_constant_expression (massaged)) |
2d76680f PC |
884 | { |
885 | if (!DECL_GENERATED_P (fun)) | |
ca30abcd | 886 | require_potential_rvalue_constant_expression (massaged); |
2d76680f PC |
887 | return NULL; |
888 | } | |
889 | ||
890 | if (DECL_CONSTRUCTOR_P (fun) | |
3e4b91f2 NS |
891 | && cx_check_missing_mem_inits (DECL_CONTEXT (fun), |
892 | massaged, !DECL_GENERATED_P (fun))) | |
2d76680f PC |
893 | return NULL; |
894 | ||
895 | /* Create the constexpr function table if necessary. */ | |
896 | if (constexpr_fundef_table == NULL) | |
897 | constexpr_fundef_table | |
898 | = hash_table<constexpr_fundef_hasher>::create_ggc (101); | |
899 | ||
900 | entry.decl = fun; | |
43574e4f JJ |
901 | tree saved_fn = current_function_decl; |
902 | bool clear_ctx = false; | |
903 | current_function_decl = fun; | |
904 | if (DECL_RESULT (fun) && DECL_CONTEXT (DECL_RESULT (fun)) == NULL_TREE) | |
905 | { | |
906 | clear_ctx = true; | |
907 | DECL_CONTEXT (DECL_RESULT (fun)) = fun; | |
908 | } | |
909 | entry.body = copy_fn (fun, entry.parms, entry.result); | |
910 | current_function_decl = saved_fn; | |
2d76680f | 911 | slot = constexpr_fundef_table->find_slot (&entry, INSERT); |
43574e4f JJ |
912 | if (clear_ctx) |
913 | DECL_CONTEXT (DECL_RESULT (fun)) = NULL_TREE; | |
2d76680f PC |
914 | |
915 | gcc_assert (*slot == NULL); | |
916 | *slot = ggc_alloc<constexpr_fundef> (); | |
917 | **slot = entry; | |
918 | ||
919 | return fun; | |
920 | } | |
921 | ||
922 | /* FUN is a non-constexpr function called in a context that requires a | |
923 | constant expression. If it comes from a constexpr template, explain why | |
924 | the instantiation isn't constexpr. */ | |
925 | ||
926 | void | |
927 | explain_invalid_constexpr_fn (tree fun) | |
928 | { | |
929 | static hash_set<tree> *diagnosed; | |
930 | tree body; | |
931 | location_t save_loc; | |
98e5a19a | 932 | /* Only diagnose defaulted functions, lambdas, or instantiations. */ |
2d76680f | 933 | if (!DECL_DEFAULTED_FN (fun) |
98e5a19a | 934 | && !LAMBDA_TYPE_P (CP_DECL_CONTEXT (fun)) |
2d76680f PC |
935 | && !is_instantiation_of_constexpr (fun)) |
936 | return; | |
937 | if (diagnosed == NULL) | |
938 | diagnosed = new hash_set<tree>; | |
939 | if (diagnosed->add (fun)) | |
940 | /* Already explained. */ | |
941 | return; | |
942 | ||
943 | save_loc = input_location; | |
98e5a19a JM |
944 | if (!lambda_static_thunk_p (fun)) |
945 | { | |
946 | /* Diagnostics should completely ignore the static thunk, so leave | |
947 | input_location set to our caller's location. */ | |
948 | input_location = DECL_SOURCE_LOCATION (fun); | |
949 | inform (input_location, | |
84fa214d | 950 | "%qD is not usable as a %<constexpr%> function because:", fun); |
98e5a19a | 951 | } |
2d76680f PC |
952 | /* First check the declaration. */ |
953 | if (is_valid_constexpr_fn (fun, true)) | |
954 | { | |
955 | /* Then if it's OK, the body. */ | |
98e5a19a JM |
956 | if (!DECL_DECLARED_CONSTEXPR_P (fun) |
957 | && !LAMBDA_TYPE_P (CP_DECL_CONTEXT (fun))) | |
2d76680f PC |
958 | explain_implicit_non_constexpr (fun); |
959 | else | |
960 | { | |
961 | body = massage_constexpr_body (fun, DECL_SAVED_TREE (fun)); | |
962 | require_potential_rvalue_constant_expression (body); | |
963 | if (DECL_CONSTRUCTOR_P (fun)) | |
3e4b91f2 | 964 | cx_check_missing_mem_inits (DECL_CONTEXT (fun), body, true); |
2d76680f PC |
965 | } |
966 | } | |
967 | input_location = save_loc; | |
968 | } | |
969 | ||
970 | /* Objects of this type represent calls to constexpr functions | |
971 | along with the bindings of parameters to their arguments, for | |
972 | the purpose of compile time evaluation. */ | |
973 | ||
974 | struct GTY((for_user)) constexpr_call { | |
975 | /* Description of the constexpr function definition. */ | |
976 | constexpr_fundef *fundef; | |
977 | /* Parameter bindings environment. A TREE_LIST where each TREE_PURPOSE | |
978 | is a parameter _DECL and the TREE_VALUE is the value of the parameter. | |
979 | Note: This arrangement is made to accommodate the use of | |
980 | iterative_hash_template_arg (see pt.c). If you change this | |
981 | representation, also change the hash calculation in | |
982 | cxx_eval_call_expression. */ | |
983 | tree bindings; | |
984 | /* Result of the call. | |
985 | NULL means the call is being evaluated. | |
986 | error_mark_node means that the evaluation was erroneous; | |
987 | otherwise, the actuall value of the call. */ | |
988 | tree result; | |
989 | /* The hash of this call; we remember it here to avoid having to | |
990 | recalculate it when expanding the hash table. */ | |
991 | hashval_t hash; | |
cce3ae91 | 992 | /* Whether __builtin_is_constant_evaluated() should evaluate to true. */ |
13de99bc | 993 | bool manifestly_const_eval; |
2d76680f PC |
994 | }; |
995 | ||
ca752f39 | 996 | struct constexpr_call_hasher : ggc_ptr_hash<constexpr_call> |
2d76680f PC |
997 | { |
998 | static hashval_t hash (constexpr_call *); | |
999 | static bool equal (constexpr_call *, constexpr_call *); | |
3e605b20 JM |
1000 | }; |
1001 | ||
4b390698 JJ |
1002 | enum constexpr_switch_state { |
1003 | /* Used when processing a switch for the first time by cxx_eval_switch_expr | |
1004 | and default: label for that switch has not been seen yet. */ | |
1005 | css_default_not_seen, | |
1006 | /* Used when processing a switch for the first time by cxx_eval_switch_expr | |
1007 | and default: label for that switch has been seen already. */ | |
1008 | css_default_seen, | |
1009 | /* Used when processing a switch for the second time by | |
1010 | cxx_eval_switch_expr, where default: label should match. */ | |
1011 | css_default_processing | |
1012 | }; | |
1013 | ||
3e605b20 JM |
1014 | /* The constexpr expansion context. CALL is the current function |
1015 | expansion, CTOR is the current aggregate initializer, OBJECT is the | |
1016 | object being initialized by CTOR, either a VAR_DECL or a _REF. VALUES | |
1017 | is a map of values of variables initialized within the expression. */ | |
1018 | ||
1019 | struct constexpr_ctx { | |
13f649f6 | 1020 | /* The innermost call we're evaluating. */ |
3e605b20 | 1021 | constexpr_call *call; |
13f649f6 JM |
1022 | /* Values for any temporaries or local variables within the |
1023 | constant-expression. */ | |
3e605b20 | 1024 | hash_map<tree,tree> *values; |
39dce2b7 JM |
1025 | /* SAVE_EXPRs that we've seen within the current LOOP_EXPR. NULL if we |
1026 | aren't inside a loop. */ | |
0ee28590 | 1027 | vec<tree> *save_exprs; |
13f649f6 JM |
1028 | /* The CONSTRUCTOR we're currently building up for an aggregate |
1029 | initializer. */ | |
3e605b20 | 1030 | tree ctor; |
13f649f6 | 1031 | /* The object we're building the CONSTRUCTOR for. */ |
3e605b20 | 1032 | tree object; |
4b390698 JJ |
1033 | /* If inside SWITCH_EXPR. */ |
1034 | constexpr_switch_state *css_state; | |
a15ffa22 JJ |
1035 | /* Number of cxx_eval_constant_expression calls (except skipped ones, |
1036 | on simple constants or location wrappers) encountered during current | |
1037 | cxx_eval_outermost_constant_expr call. */ | |
1038 | HOST_WIDE_INT *constexpr_ops_count; | |
1039 | ||
13f649f6 | 1040 | /* Whether we should error on a non-constant expression or fail quietly. */ |
2b3ab879 | 1041 | bool quiet; |
13f649f6 JM |
1042 | /* Whether we are strictly conforming to constant expression rules or |
1043 | trying harder to get a constant value. */ | |
69eb4fde | 1044 | bool strict; |
e4082611 | 1045 | /* Whether __builtin_is_constant_evaluated () should be true. */ |
13de99bc | 1046 | bool manifestly_const_eval; |
3e605b20 | 1047 | }; |
2d76680f PC |
1048 | |
1049 | /* A table of all constexpr calls that have been evaluated by the | |
1050 | compiler in this translation unit. */ | |
1051 | ||
97f3003f | 1052 | static GTY (()) hash_table<constexpr_call_hasher> *constexpr_call_table; |
2d76680f | 1053 | |
3e605b20 | 1054 | static tree cxx_eval_constant_expression (const constexpr_ctx *, tree, |
5a804683 | 1055 | bool, bool *, bool *, tree * = NULL); |
2d76680f PC |
1056 | |
1057 | /* Compute a hash value for a constexpr call representation. */ | |
1058 | ||
1059 | inline hashval_t | |
1060 | constexpr_call_hasher::hash (constexpr_call *info) | |
1061 | { | |
1062 | return info->hash; | |
1063 | } | |
1064 | ||
1065 | /* Return true if the objects pointed to by P and Q represent calls | |
1066 | to the same constexpr function with the same arguments. | |
1067 | Otherwise, return false. */ | |
1068 | ||
1069 | bool | |
1070 | constexpr_call_hasher::equal (constexpr_call *lhs, constexpr_call *rhs) | |
1071 | { | |
1072 | tree lhs_bindings; | |
1073 | tree rhs_bindings; | |
1074 | if (lhs == rhs) | |
46cf7fa1 JJ |
1075 | return true; |
1076 | if (lhs->hash != rhs->hash) | |
1077 | return false; | |
13de99bc | 1078 | if (lhs->manifestly_const_eval != rhs->manifestly_const_eval) |
cce3ae91 | 1079 | return false; |
2d76680f | 1080 | if (!constexpr_fundef_hasher::equal (lhs->fundef, rhs->fundef)) |
46cf7fa1 | 1081 | return false; |
2d76680f PC |
1082 | lhs_bindings = lhs->bindings; |
1083 | rhs_bindings = rhs->bindings; | |
1084 | while (lhs_bindings != NULL && rhs_bindings != NULL) | |
1085 | { | |
1086 | tree lhs_arg = TREE_VALUE (lhs_bindings); | |
1087 | tree rhs_arg = TREE_VALUE (rhs_bindings); | |
47be9509 | 1088 | gcc_assert (same_type_p (TREE_TYPE (lhs_arg), TREE_TYPE (rhs_arg))); |
2d76680f | 1089 | if (!cp_tree_equal (lhs_arg, rhs_arg)) |
46cf7fa1 | 1090 | return false; |
2d76680f PC |
1091 | lhs_bindings = TREE_CHAIN (lhs_bindings); |
1092 | rhs_bindings = TREE_CHAIN (rhs_bindings); | |
1093 | } | |
1094 | return lhs_bindings == rhs_bindings; | |
1095 | } | |
1096 | ||
1097 | /* Initialize the constexpr call table, if needed. */ | |
1098 | ||
1099 | static void | |
1100 | maybe_initialize_constexpr_call_table (void) | |
1101 | { | |
1102 | if (constexpr_call_table == NULL) | |
1103 | constexpr_call_table = hash_table<constexpr_call_hasher>::create_ggc (101); | |
1104 | } | |
1105 | ||
c0daf32d PP |
1106 | /* During constexpr CALL_EXPR evaluation, to avoid issues with sharing when |
1107 | a function happens to get called recursively, we unshare the callee | |
1108 | function's body and evaluate this unshared copy instead of evaluating the | |
1109 | original body. | |
1110 | ||
1111 | FUNDEF_COPIES_TABLE is a per-function freelist of these unshared function | |
1112 | copies. The underlying data structure of FUNDEF_COPIES_TABLE is a hash_map | |
97f3003f JM |
1113 | that's keyed off of the original FUNCTION_DECL and whose value is a |
1114 | TREE_LIST of this function's unused copies awaiting reuse. | |
c0daf32d | 1115 | |
97f3003f | 1116 | This is not GC-deletable to avoid GC affecting UID generation. */ |
c0daf32d | 1117 | |
97f3003f | 1118 | static GTY(()) hash_map<tree, tree> *fundef_copies_table; |
c0daf32d PP |
1119 | |
1120 | /* Initialize FUNDEF_COPIES_TABLE if it's not initialized. */ | |
1121 | ||
1122 | static void | |
1123 | maybe_initialize_fundef_copies_table () | |
1124 | { | |
97f3003f JM |
1125 | if (fundef_copies_table == NULL) |
1126 | fundef_copies_table = hash_map<tree,tree>::create_ggc (101); | |
c0daf32d PP |
1127 | } |
1128 | ||
1129 | /* Reuse a copy or create a new unshared copy of the function FUN. | |
3c98ff9b NS |
1130 | Return this copy. We use a TREE_LIST whose PURPOSE is body, VALUE |
1131 | is parms, TYPE is result. */ | |
c0daf32d | 1132 | |
97f3003f | 1133 | static tree |
43574e4f | 1134 | get_fundef_copy (constexpr_fundef *fundef) |
c0daf32d PP |
1135 | { |
1136 | maybe_initialize_fundef_copies_table (); | |
1137 | ||
97f3003f | 1138 | tree copy; |
3c98ff9b | 1139 | bool existed; |
43574e4f | 1140 | tree *slot = &fundef_copies_table->get_or_insert (fundef->decl, &existed); |
3c98ff9b NS |
1141 | |
1142 | if (!existed) | |
c0daf32d | 1143 | { |
3c98ff9b NS |
1144 | /* There is no cached function available, or in use. We can use |
1145 | the function directly. That the slot is now created records | |
1146 | that this function is now in use. */ | |
43574e4f JJ |
1147 | copy = build_tree_list (fundef->body, fundef->parms); |
1148 | TREE_TYPE (copy) = fundef->result; | |
3c98ff9b NS |
1149 | } |
1150 | else if (*slot == NULL_TREE) | |
1151 | { | |
1152 | /* We've already used the function itself, so make a copy. */ | |
97f3003f | 1153 | copy = build_tree_list (NULL, NULL); |
43574e4f JJ |
1154 | tree saved_body = DECL_SAVED_TREE (fundef->decl); |
1155 | tree saved_parms = DECL_ARGUMENTS (fundef->decl); | |
1156 | tree saved_result = DECL_RESULT (fundef->decl); | |
1157 | tree saved_fn = current_function_decl; | |
1158 | DECL_SAVED_TREE (fundef->decl) = fundef->body; | |
1159 | DECL_ARGUMENTS (fundef->decl) = fundef->parms; | |
1160 | DECL_RESULT (fundef->decl) = fundef->result; | |
1161 | current_function_decl = fundef->decl; | |
1162 | TREE_PURPOSE (copy) = copy_fn (fundef->decl, TREE_VALUE (copy), | |
1163 | TREE_TYPE (copy)); | |
1164 | current_function_decl = saved_fn; | |
1165 | DECL_RESULT (fundef->decl) = saved_result; | |
1166 | DECL_ARGUMENTS (fundef->decl) = saved_parms; | |
1167 | DECL_SAVED_TREE (fundef->decl) = saved_body; | |
c0daf32d PP |
1168 | } |
1169 | else | |
1170 | { | |
3c98ff9b | 1171 | /* We have a cached function available. */ |
c0daf32d | 1172 | copy = *slot; |
97f3003f | 1173 | *slot = TREE_CHAIN (copy); |
c0daf32d PP |
1174 | } |
1175 | ||
1176 | return copy; | |
1177 | } | |
1178 | ||
3c98ff9b NS |
1179 | /* Save the copy COPY of function FUN for later reuse by |
1180 | get_fundef_copy(). By construction, there will always be an entry | |
1181 | to find. */ | |
c0daf32d PP |
1182 | |
1183 | static void | |
97f3003f | 1184 | save_fundef_copy (tree fun, tree copy) |
c0daf32d | 1185 | { |
3c98ff9b | 1186 | tree *slot = fundef_copies_table->get (fun); |
97f3003f | 1187 | TREE_CHAIN (copy) = *slot; |
c0daf32d PP |
1188 | *slot = copy; |
1189 | } | |
1190 | ||
2d76680f PC |
1191 | /* We have an expression tree T that represents a call, either CALL_EXPR |
1192 | or AGGR_INIT_EXPR. Return the Nth argument. */ | |
1193 | ||
1194 | static inline tree | |
1195 | get_nth_callarg (tree t, int n) | |
1196 | { | |
1197 | switch (TREE_CODE (t)) | |
1198 | { | |
1199 | case CALL_EXPR: | |
1200 | return CALL_EXPR_ARG (t, n); | |
1201 | ||
1202 | case AGGR_INIT_EXPR: | |
1203 | return AGGR_INIT_EXPR_ARG (t, n); | |
1204 | ||
1205 | default: | |
1206 | gcc_unreachable (); | |
1207 | return NULL; | |
1208 | } | |
1209 | } | |
1210 | ||
2d76680f PC |
1211 | /* Attempt to evaluate T which represents a call to a builtin function. |
1212 | We assume here that all builtin functions evaluate to scalar types | |
1213 | represented by _CST nodes. */ | |
1214 | ||
1215 | static tree | |
5756d0f9 | 1216 | cxx_eval_builtin_function_call (const constexpr_ctx *ctx, tree t, tree fun, |
92a596e8 | 1217 | bool lval, |
2d76680f PC |
1218 | bool *non_constant_p, bool *overflow_p) |
1219 | { | |
1220 | const int nargs = call_expr_nargs (t); | |
1221 | tree *args = (tree *) alloca (nargs * sizeof (tree)); | |
1222 | tree new_call; | |
1223 | int i; | |
5756d0f9 JM |
1224 | |
1225 | /* Don't fold __builtin_constant_p within a constexpr function. */ | |
e4082611 | 1226 | bool bi_const_p = DECL_IS_BUILTIN_CONSTANT_P (fun); |
b925d25d | 1227 | |
fe736ffd JM |
1228 | /* If we aren't requiring a constant expression, defer __builtin_constant_p |
1229 | in a constexpr function until we have values for the parameters. */ | |
b925d25d | 1230 | if (bi_const_p |
4cd3e7df | 1231 | && !ctx->manifestly_const_eval |
5756d0f9 JM |
1232 | && current_function_decl |
1233 | && DECL_DECLARED_CONSTEXPR_P (current_function_decl)) | |
2d76680f | 1234 | { |
5756d0f9 JM |
1235 | *non_constant_p = true; |
1236 | return t; | |
2d76680f | 1237 | } |
5756d0f9 | 1238 | |
e4082611 | 1239 | /* For __builtin_is_constant_evaluated, defer it if not |
13de99bc | 1240 | ctx->manifestly_const_eval, otherwise fold it to true. */ |
3d78e008 | 1241 | if (fndecl_built_in_p (fun, CP_BUILT_IN_IS_CONSTANT_EVALUATED, |
13de99bc | 1242 | BUILT_IN_FRONTEND)) |
e4082611 | 1243 | { |
13de99bc | 1244 | if (!ctx->manifestly_const_eval) |
e4082611 JJ |
1245 | { |
1246 | *non_constant_p = true; | |
1247 | return t; | |
1248 | } | |
1249 | return boolean_true_node; | |
1250 | } | |
1251 | ||
5756d0f9 JM |
1252 | /* Be permissive for arguments to built-ins; __builtin_constant_p should |
1253 | return constant false for a non-constant argument. */ | |
1254 | constexpr_ctx new_ctx = *ctx; | |
1255 | new_ctx.quiet = true; | |
5756d0f9 | 1256 | for (i = 0; i < nargs; ++i) |
b925d25d | 1257 | { |
2ff7172a JJ |
1258 | args[i] = CALL_EXPR_ARG (t, i); |
1259 | /* If builtin_valid_in_constant_expr_p is true, | |
1260 | potential_constant_expression_1 has not recursed into the arguments | |
1261 | of the builtin, verify it here. */ | |
1262 | if (!builtin_valid_in_constant_expr_p (fun) | |
1263 | || potential_constant_expression (args[i])) | |
4cd3e7df JJ |
1264 | { |
1265 | bool dummy1 = false, dummy2 = false; | |
1266 | args[i] = cxx_eval_constant_expression (&new_ctx, args[i], false, | |
1267 | &dummy1, &dummy2); | |
1268 | } | |
1269 | ||
b925d25d | 1270 | if (bi_const_p) |
4cd3e7df | 1271 | /* For __builtin_constant_p, fold all expressions with constant values |
b925d25d | 1272 | even if they aren't C++ constant-expressions. */ |
4cd3e7df | 1273 | args[i] = cp_fold_rvalue (args[i]); |
b925d25d | 1274 | } |
5756d0f9 JM |
1275 | |
1276 | bool save_ffbcp = force_folding_builtin_constant_p; | |
1277 | force_folding_builtin_constant_p = true; | |
43574e4f JJ |
1278 | tree save_cur_fn = current_function_decl; |
1279 | /* Return name of ctx->call->fundef->decl for __builtin_FUNCTION (). */ | |
1280 | if (fndecl_built_in_p (fun, BUILT_IN_FUNCTION) | |
1281 | && ctx->call | |
1282 | && ctx->call->fundef) | |
1283 | current_function_decl = ctx->call->fundef->decl; | |
109d2197 JJ |
1284 | new_call = fold_builtin_call_array (EXPR_LOCATION (t), TREE_TYPE (t), |
1285 | CALL_EXPR_FN (t), nargs, args); | |
43574e4f | 1286 | current_function_decl = save_cur_fn; |
5756d0f9 | 1287 | force_folding_builtin_constant_p = save_ffbcp; |
109d2197 JJ |
1288 | if (new_call == NULL) |
1289 | { | |
1290 | if (!*non_constant_p && !ctx->quiet) | |
1291 | { | |
1b6fa695 ML |
1292 | /* Do not allow__builtin_unreachable in constexpr function. |
1293 | The __builtin_unreachable call with BUILTINS_LOCATION | |
1294 | comes from cp_maybe_instrument_return. */ | |
3d78e008 | 1295 | if (fndecl_built_in_p (fun, BUILT_IN_UNREACHABLE) |
1b6fa695 | 1296 | && EXPR_LOCATION (t) == BUILTINS_LOCATION) |
84fa214d | 1297 | error ("%<constexpr%> call flows off the end of the function"); |
1b6fa695 ML |
1298 | else |
1299 | { | |
1300 | new_call = build_call_array_loc (EXPR_LOCATION (t), TREE_TYPE (t), | |
1301 | CALL_EXPR_FN (t), nargs, args); | |
1302 | error ("%q+E is not a constant expression", new_call); | |
1303 | } | |
109d2197 JJ |
1304 | } |
1305 | *non_constant_p = true; | |
1306 | return t; | |
1307 | } | |
1308 | ||
43574e4f | 1309 | if (!potential_constant_expression (new_call)) |
109d2197 JJ |
1310 | { |
1311 | if (!*non_constant_p && !ctx->quiet) | |
1312 | error ("%q+E is not a constant expression", new_call); | |
1313 | *non_constant_p = true; | |
1314 | return t; | |
1315 | } | |
1316 | ||
1317 | return cxx_eval_constant_expression (&new_ctx, new_call, lval, | |
1318 | non_constant_p, overflow_p); | |
2d76680f PC |
1319 | } |
1320 | ||
1321 | /* TEMP is the constant value of a temporary object of type TYPE. Adjust | |
1322 | the type of the value to match. */ | |
1323 | ||
1324 | static tree | |
1325 | adjust_temp_type (tree type, tree temp) | |
1326 | { | |
47be9509 | 1327 | if (same_type_p (TREE_TYPE (temp), type)) |
2d76680f PC |
1328 | return temp; |
1329 | /* Avoid wrapping an aggregate value in a NOP_EXPR. */ | |
1330 | if (TREE_CODE (temp) == CONSTRUCTOR) | |
b27f74e7 MP |
1331 | { |
1332 | /* build_constructor wouldn't retain various CONSTRUCTOR flags. */ | |
1333 | tree t = copy_node (temp); | |
1334 | TREE_TYPE (t) = type; | |
1335 | return t; | |
1336 | } | |
ff8ba86f JJ |
1337 | if (TREE_CODE (temp) == EMPTY_CLASS_EXPR) |
1338 | return build0 (EMPTY_CLASS_EXPR, type); | |
2d76680f PC |
1339 | gcc_assert (scalarish_type_p (type)); |
1340 | return cp_fold_convert (type, temp); | |
1341 | } | |
1342 | ||
0146e25f PP |
1343 | /* Callback for walk_tree used by unshare_constructor. */ |
1344 | ||
1345 | static tree | |
1346 | find_constructor (tree *tp, int *walk_subtrees, void *) | |
1347 | { | |
1348 | if (TYPE_P (*tp)) | |
1349 | *walk_subtrees = 0; | |
1350 | if (TREE_CODE (*tp) == CONSTRUCTOR) | |
1351 | return *tp; | |
1352 | return NULL_TREE; | |
1353 | } | |
1354 | ||
1355 | /* If T is a CONSTRUCTOR or an expression that has a CONSTRUCTOR node as a | |
1356 | subexpression, return an unshared copy of T. Otherwise return T. */ | |
1357 | ||
1f6857ba | 1358 | tree |
0146e25f PP |
1359 | unshare_constructor (tree t) |
1360 | { | |
1361 | tree ctor = walk_tree (&t, find_constructor, NULL, NULL); | |
1362 | if (ctor != NULL_TREE) | |
1363 | return unshare_expr (t); | |
1364 | return t; | |
1365 | } | |
1366 | ||
2d76680f PC |
1367 | /* Subroutine of cxx_eval_call_expression. |
1368 | We are processing a call expression (either CALL_EXPR or | |
3e605b20 | 1369 | AGGR_INIT_EXPR) in the context of CTX. Evaluate |
2d76680f PC |
1370 | all arguments and bind their values to correspondings |
1371 | parameters, making up the NEW_CALL context. */ | |
1372 | ||
1373 | static void | |
3e605b20 | 1374 | cxx_bind_parameters_in_call (const constexpr_ctx *ctx, tree t, |
2d76680f | 1375 | constexpr_call *new_call, |
12d9ce19 JM |
1376 | bool *non_constant_p, bool *overflow_p, |
1377 | bool *non_constant_args) | |
2d76680f PC |
1378 | { |
1379 | const int nargs = call_expr_nargs (t); | |
1380 | tree fun = new_call->fundef->decl; | |
43574e4f | 1381 | tree parms = new_call->fundef->parms; |
2d76680f | 1382 | int i; |
60813a46 | 1383 | tree *p = &new_call->bindings; |
2d76680f PC |
1384 | for (i = 0; i < nargs; ++i) |
1385 | { | |
1386 | tree x, arg; | |
1387 | tree type = parms ? TREE_TYPE (parms) : void_type_node; | |
2d76680f | 1388 | x = get_nth_callarg (t, i); |
3e605b20 JM |
1389 | /* For member function, the first argument is a pointer to the implied |
1390 | object. For a constructor, it might still be a dummy object, in | |
60813a46 | 1391 | which case we get the real argument from ctx. */ |
3e605b20 JM |
1392 | if (i == 0 && DECL_CONSTRUCTOR_P (fun) |
1393 | && is_dummy_object (x)) | |
1394 | { | |
1395 | x = ctx->object; | |
84dd815f | 1396 | x = build_address (x); |
3e605b20 | 1397 | } |
43574e4f JJ |
1398 | if (TREE_ADDRESSABLE (type)) |
1399 | /* Undo convert_for_arg_passing work here. */ | |
1400 | x = convert_from_reference (x); | |
0e038601 | 1401 | arg = cxx_eval_constant_expression (ctx, x, /*lval=*/false, |
5a804683 | 1402 | non_constant_p, overflow_p); |
2d76680f | 1403 | /* Don't VERIFY_CONSTANT here. */ |
2b3ab879 | 1404 | if (*non_constant_p && ctx->quiet) |
2d76680f PC |
1405 | return; |
1406 | /* Just discard ellipsis args after checking their constantitude. */ | |
1407 | if (!parms) | |
1408 | continue; | |
4727d4c6 NS |
1409 | |
1410 | if (!*non_constant_p) | |
1411 | { | |
1dc23505 MP |
1412 | /* Don't share a CONSTRUCTOR that might be changed. */ |
1413 | arg = unshare_constructor (arg); | |
4727d4c6 NS |
1414 | /* Make sure the binding has the same type as the parm. But |
1415 | only for constant args. */ | |
9f613f06 | 1416 | if (!TYPE_REF_P (type)) |
4727d4c6 NS |
1417 | arg = adjust_temp_type (type, arg); |
1418 | if (!TREE_CONSTANT (arg)) | |
1419 | *non_constant_args = true; | |
1420 | *p = build_tree_list (parms, arg); | |
1421 | p = &TREE_CHAIN (*p); | |
1422 | } | |
2d76680f PC |
1423 | parms = TREE_CHAIN (parms); |
1424 | } | |
1425 | } | |
1426 | ||
1427 | /* Variables and functions to manage constexpr call expansion context. | |
1428 | These do not need to be marked for PCH or GC. */ | |
1429 | ||
1430 | /* FIXME remember and print actual constant arguments. */ | |
7de76362 | 1431 | static vec<tree> call_stack; |
2d76680f PC |
1432 | static int call_stack_tick; |
1433 | static int last_cx_error_tick; | |
1434 | ||
1435 | static bool | |
1436 | push_cx_call_context (tree call) | |
1437 | { | |
1438 | ++call_stack_tick; | |
1439 | if (!EXPR_HAS_LOCATION (call)) | |
1440 | SET_EXPR_LOCATION (call, input_location); | |
1441 | call_stack.safe_push (call); | |
1442 | if (call_stack.length () > (unsigned) max_constexpr_depth) | |
1443 | return false; | |
1444 | return true; | |
1445 | } | |
1446 | ||
1447 | static void | |
1448 | pop_cx_call_context (void) | |
1449 | { | |
1450 | ++call_stack_tick; | |
1451 | call_stack.pop (); | |
1452 | } | |
1453 | ||
1454 | vec<tree> | |
1455 | cx_error_context (void) | |
1456 | { | |
1457 | vec<tree> r = vNULL; | |
1458 | if (call_stack_tick != last_cx_error_tick | |
1459 | && !call_stack.is_empty ()) | |
1460 | r = call_stack; | |
1461 | last_cx_error_tick = call_stack_tick; | |
1462 | return r; | |
1463 | } | |
1464 | ||
44a845ca MS |
1465 | /* Evaluate a call T to a GCC internal function when possible and return |
1466 | the evaluated result or, under the control of CTX, give an error, set | |
1467 | NON_CONSTANT_P, and return the unevaluated call T otherwise. */ | |
1468 | ||
1469 | static tree | |
1470 | cxx_eval_internal_function (const constexpr_ctx *ctx, tree t, | |
1471 | bool lval, | |
1472 | bool *non_constant_p, bool *overflow_p) | |
1473 | { | |
1474 | enum tree_code opcode = ERROR_MARK; | |
1475 | ||
1476 | switch (CALL_EXPR_IFN (t)) | |
1477 | { | |
1478 | case IFN_UBSAN_NULL: | |
1479 | case IFN_UBSAN_BOUNDS: | |
1480 | case IFN_UBSAN_VPTR: | |
81fea426 | 1481 | case IFN_FALLTHROUGH: |
44a845ca MS |
1482 | return void_node; |
1483 | ||
1484 | case IFN_ADD_OVERFLOW: | |
1485 | opcode = PLUS_EXPR; | |
1486 | break; | |
1487 | case IFN_SUB_OVERFLOW: | |
1488 | opcode = MINUS_EXPR; | |
1489 | break; | |
1490 | case IFN_MUL_OVERFLOW: | |
1491 | opcode = MULT_EXPR; | |
1492 | break; | |
1493 | ||
e16f1cc7 JJ |
1494 | case IFN_LAUNDER: |
1495 | return cxx_eval_constant_expression (ctx, CALL_EXPR_ARG (t, 0), | |
1496 | false, non_constant_p, overflow_p); | |
1497 | ||
d8fcab68 JJ |
1498 | case IFN_VEC_CONVERT: |
1499 | { | |
1500 | tree arg = cxx_eval_constant_expression (ctx, CALL_EXPR_ARG (t, 0), | |
1501 | false, non_constant_p, | |
1502 | overflow_p); | |
1503 | if (TREE_CODE (arg) == VECTOR_CST) | |
1504 | return fold_const_call (CFN_VEC_CONVERT, TREE_TYPE (t), arg); | |
1505 | else | |
1506 | { | |
1507 | *non_constant_p = true; | |
1508 | return t; | |
1509 | } | |
1510 | } | |
1511 | ||
44a845ca MS |
1512 | default: |
1513 | if (!ctx->quiet) | |
6bdfada4 | 1514 | error_at (cp_expr_loc_or_loc (t, input_location), |
44a845ca MS |
1515 | "call to internal function %qE", t); |
1516 | *non_constant_p = true; | |
1517 | return t; | |
1518 | } | |
1519 | ||
1520 | /* Evaluate constant arguments using OPCODE and return a complex | |
1521 | number containing the result and the overflow bit. */ | |
1522 | tree arg0 = cxx_eval_constant_expression (ctx, CALL_EXPR_ARG (t, 0), lval, | |
1523 | non_constant_p, overflow_p); | |
1524 | tree arg1 = cxx_eval_constant_expression (ctx, CALL_EXPR_ARG (t, 1), lval, | |
1525 | non_constant_p, overflow_p); | |
1526 | ||
1527 | if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST) | |
1528 | { | |
6bdfada4 | 1529 | location_t loc = cp_expr_loc_or_loc (t, input_location); |
44a845ca MS |
1530 | tree type = TREE_TYPE (TREE_TYPE (t)); |
1531 | tree result = fold_binary_loc (loc, opcode, type, | |
1532 | fold_convert_loc (loc, type, arg0), | |
1533 | fold_convert_loc (loc, type, arg1)); | |
1534 | tree ovf | |
1535 | = build_int_cst (type, arith_overflowed_p (opcode, type, arg0, arg1)); | |
1536 | /* Reset TREE_OVERFLOW to avoid warnings for the overflow. */ | |
1537 | if (TREE_OVERFLOW (result)) | |
1538 | TREE_OVERFLOW (result) = 0; | |
1539 | ||
1540 | return build_complex (TREE_TYPE (t), result, ovf); | |
1541 | } | |
1542 | ||
1543 | *non_constant_p = true; | |
1544 | return t; | |
1545 | } | |
1546 | ||
e8c48716 | 1547 | /* Clean CONSTRUCTOR_NO_CLEARING from CTOR and its sub-aggregates. */ |
ecc57615 JM |
1548 | |
1549 | static void | |
1550 | clear_no_implicit_zero (tree ctor) | |
1551 | { | |
e8c48716 | 1552 | if (CONSTRUCTOR_NO_CLEARING (ctor)) |
ecc57615 | 1553 | { |
e8c48716 | 1554 | CONSTRUCTOR_NO_CLEARING (ctor) = false; |
ecc57615 JM |
1555 | tree elt; unsigned HOST_WIDE_INT idx; |
1556 | FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), idx, elt) | |
1557 | if (TREE_CODE (elt) == CONSTRUCTOR) | |
1558 | clear_no_implicit_zero (elt); | |
1559 | } | |
1560 | } | |
1561 | ||
2d76680f PC |
1562 | /* Subroutine of cxx_eval_constant_expression. |
1563 | Evaluate the call expression tree T in the context of OLD_CALL expression | |
1564 | evaluation. */ | |
1565 | ||
1566 | static tree | |
3e605b20 | 1567 | cxx_eval_call_expression (const constexpr_ctx *ctx, tree t, |
92a596e8 | 1568 | bool lval, |
2d76680f PC |
1569 | bool *non_constant_p, bool *overflow_p) |
1570 | { | |
6bdfada4 | 1571 | location_t loc = cp_expr_loc_or_loc (t, input_location); |
2d76680f | 1572 | tree fun = get_function_named_in_call (t); |
cce3ae91 | 1573 | constexpr_call new_call |
13de99bc | 1574 | = { NULL, NULL, NULL, 0, ctx->manifestly_const_eval }; |
2d76680f PC |
1575 | bool depth_ok; |
1576 | ||
0b274c17 | 1577 | if (fun == NULL_TREE) |
44a845ca MS |
1578 | return cxx_eval_internal_function (ctx, t, lval, |
1579 | non_constant_p, overflow_p); | |
0b274c17 | 1580 | |
2d76680f PC |
1581 | if (TREE_CODE (fun) != FUNCTION_DECL) |
1582 | { | |
1583 | /* Might be a constexpr function pointer. */ | |
2b3ab879 | 1584 | fun = cxx_eval_constant_expression (ctx, fun, |
92a596e8 | 1585 | /*lval*/false, non_constant_p, |
5a804683 | 1586 | overflow_p); |
2d76680f PC |
1587 | STRIP_NOPS (fun); |
1588 | if (TREE_CODE (fun) == ADDR_EXPR) | |
1589 | fun = TREE_OPERAND (fun, 0); | |
582d2481 JJ |
1590 | /* For TARGET_VTABLE_USES_DESCRIPTORS targets, there is no |
1591 | indirection, the called expression is a pointer into the | |
1592 | virtual table which should contain FDESC_EXPR. Extract the | |
1593 | FUNCTION_DECL from there. */ | |
1594 | else if (TARGET_VTABLE_USES_DESCRIPTORS | |
1595 | && TREE_CODE (fun) == POINTER_PLUS_EXPR | |
1596 | && TREE_CODE (TREE_OPERAND (fun, 0)) == ADDR_EXPR | |
1597 | && TREE_CODE (TREE_OPERAND (fun, 1)) == INTEGER_CST) | |
1598 | { | |
1599 | tree d = TREE_OPERAND (TREE_OPERAND (fun, 0), 0); | |
1600 | if (VAR_P (d) | |
1601 | && DECL_VTABLE_OR_VTT_P (d) | |
1602 | && TREE_CODE (TREE_TYPE (d)) == ARRAY_TYPE | |
1603 | && TREE_TYPE (TREE_TYPE (d)) == vtable_entry_type | |
1604 | && DECL_INITIAL (d) | |
1605 | && TREE_CODE (DECL_INITIAL (d)) == CONSTRUCTOR) | |
1606 | { | |
1607 | tree i = int_const_binop (TRUNC_DIV_EXPR, TREE_OPERAND (fun, 1), | |
1608 | TYPE_SIZE_UNIT (vtable_entry_type)); | |
1609 | HOST_WIDE_INT idx = find_array_ctor_elt (DECL_INITIAL (d), i); | |
1610 | if (idx >= 0) | |
1611 | { | |
1612 | tree fdesc | |
1613 | = (*CONSTRUCTOR_ELTS (DECL_INITIAL (d)))[idx].value; | |
1614 | if (TREE_CODE (fdesc) == FDESC_EXPR | |
1615 | && integer_zerop (TREE_OPERAND (fdesc, 1))) | |
1616 | fun = TREE_OPERAND (fdesc, 0); | |
1617 | } | |
1618 | } | |
1619 | } | |
2d76680f PC |
1620 | } |
1621 | if (TREE_CODE (fun) != FUNCTION_DECL) | |
1622 | { | |
2b3ab879 | 1623 | if (!ctx->quiet && !*non_constant_p) |
84fa214d | 1624 | error_at (loc, "expression %qE does not designate a %<constexpr%> " |
2d76680f PC |
1625 | "function", fun); |
1626 | *non_constant_p = true; | |
1627 | return t; | |
1628 | } | |
1629 | if (DECL_CLONED_FUNCTION_P (fun)) | |
1630 | fun = DECL_CLONED_FUNCTION (fun); | |
0b274c17 MP |
1631 | |
1632 | if (is_ubsan_builtin_p (fun)) | |
1633 | return void_node; | |
1634 | ||
3d78e008 | 1635 | if (fndecl_built_in_p (fun)) |
5756d0f9 | 1636 | return cxx_eval_builtin_function_call (ctx, t, fun, |
92a596e8 | 1637 | lval, non_constant_p, overflow_p); |
2d76680f PC |
1638 | if (!DECL_DECLARED_CONSTEXPR_P (fun)) |
1639 | { | |
2b3ab879 | 1640 | if (!ctx->quiet) |
2d76680f | 1641 | { |
11399477 | 1642 | if (!lambda_static_thunk_p (fun)) |
84fa214d | 1643 | error_at (loc, "call to non-%<constexpr%> function %qD", fun); |
2d76680f PC |
1644 | explain_invalid_constexpr_fn (fun); |
1645 | } | |
1646 | *non_constant_p = true; | |
1647 | return t; | |
1648 | } | |
1649 | ||
86461cad JM |
1650 | constexpr_ctx new_ctx = *ctx; |
1651 | if (DECL_CONSTRUCTOR_P (fun) && !ctx->object | |
1652 | && TREE_CODE (t) == AGGR_INIT_EXPR) | |
1653 | { | |
1654 | /* We want to have an initialization target for an AGGR_INIT_EXPR. | |
1655 | If we don't already have one in CTX, use the AGGR_INIT_EXPR_SLOT. */ | |
1656 | new_ctx.object = AGGR_INIT_EXPR_SLOT (t); | |
1657 | tree ctor = new_ctx.ctor = build_constructor (DECL_CONTEXT (fun), NULL); | |
e8c48716 | 1658 | CONSTRUCTOR_NO_CLEARING (ctor) = true; |
86461cad JM |
1659 | ctx->values->put (new_ctx.object, ctor); |
1660 | ctx = &new_ctx; | |
1661 | } | |
1662 | ||
2d76680f PC |
1663 | /* Shortcut trivial constructor/op=. */ |
1664 | if (trivial_fn_p (fun)) | |
1665 | { | |
86461cad | 1666 | tree init = NULL_TREE; |
2d76680f | 1667 | if (call_expr_nargs (t) == 2) |
86461cad | 1668 | init = convert_from_reference (get_nth_callarg (t, 1)); |
2d76680f PC |
1669 | else if (TREE_CODE (t) == AGGR_INIT_EXPR |
1670 | && AGGR_INIT_ZERO_FIRST (t)) | |
86461cad JM |
1671 | init = build_zero_init (DECL_CONTEXT (fun), NULL_TREE, false); |
1672 | if (init) | |
1673 | { | |
1674 | tree op = get_nth_callarg (t, 0); | |
1675 | if (is_dummy_object (op)) | |
1676 | op = ctx->object; | |
1677 | else | |
1678 | op = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (op)), op); | |
1679 | tree set = build2 (MODIFY_EXPR, TREE_TYPE (op), op, init); | |
c8816908 JM |
1680 | new_ctx.call = &new_call; |
1681 | return cxx_eval_constant_expression (&new_ctx, set, lval, | |
86461cad JM |
1682 | non_constant_p, overflow_p); |
1683 | } | |
2d76680f PC |
1684 | } |
1685 | ||
81371eff JM |
1686 | /* We can't defer instantiating the function any longer. */ |
1687 | if (!DECL_INITIAL (fun) | |
1688 | && DECL_TEMPLOID_INSTANTIATION (fun)) | |
1689 | { | |
f065303f JM |
1690 | location_t save_loc = input_location; |
1691 | input_location = loc; | |
81371eff JM |
1692 | ++function_depth; |
1693 | instantiate_decl (fun, /*defer_ok*/false, /*expl_inst*/false); | |
1694 | --function_depth; | |
f065303f | 1695 | input_location = save_loc; |
81371eff JM |
1696 | } |
1697 | ||
2d76680f | 1698 | /* If in direct recursive call, optimize definition search. */ |
c8816908 | 1699 | if (ctx && ctx->call && ctx->call->fundef && ctx->call->fundef->decl == fun) |
3e605b20 | 1700 | new_call.fundef = ctx->call->fundef; |
2d76680f PC |
1701 | else |
1702 | { | |
1703 | new_call.fundef = retrieve_constexpr_fundef (fun); | |
4ddcdbf9 JM |
1704 | if (new_call.fundef == NULL || new_call.fundef->body == NULL |
1705 | || fun == current_function_decl) | |
2d76680f | 1706 | { |
2b3ab879 | 1707 | if (!ctx->quiet) |
2d76680f | 1708 | { |
4ddcdbf9 JM |
1709 | /* We need to check for current_function_decl here in case we're |
1710 | being called during cp_fold_function, because at that point | |
1711 | DECL_INITIAL is set properly and we have a fundef but we | |
1712 | haven't lowered invisirefs yet (c++/70344). */ | |
1713 | if (DECL_INITIAL (fun) == error_mark_node | |
1714 | || fun == current_function_decl) | |
ddd6d421 JM |
1715 | error_at (loc, "%qD called in a constant expression before its " |
1716 | "definition is complete", fun); | |
1717 | else if (DECL_INITIAL (fun)) | |
2d76680f | 1718 | { |
98e5a19a JM |
1719 | /* The definition of fun was somehow unsuitable. But pretend |
1720 | that lambda static thunks don't exist. */ | |
1721 | if (!lambda_static_thunk_p (fun)) | |
1722 | error_at (loc, "%qD called in a constant expression", fun); | |
2d76680f PC |
1723 | explain_invalid_constexpr_fn (fun); |
1724 | } | |
1725 | else | |
1726 | error_at (loc, "%qD used before its definition", fun); | |
1727 | } | |
1728 | *non_constant_p = true; | |
1729 | return t; | |
1730 | } | |
1731 | } | |
60813a46 | 1732 | |
12d9ce19 | 1733 | bool non_constant_args = false; |
3e605b20 | 1734 | cxx_bind_parameters_in_call (ctx, t, &new_call, |
12d9ce19 | 1735 | non_constant_p, overflow_p, &non_constant_args); |
2d76680f PC |
1736 | if (*non_constant_p) |
1737 | return t; | |
1738 | ||
1739 | depth_ok = push_cx_call_context (t); | |
1740 | ||
12d9ce19 | 1741 | tree result = NULL_TREE; |
2d76680f | 1742 | |
12d9ce19 | 1743 | constexpr_call *entry = NULL; |
4a58d2fe | 1744 | if (depth_ok && !non_constant_args && ctx->strict) |
2d76680f | 1745 | { |
cce3ae91 JJ |
1746 | new_call.hash = constexpr_fundef_hasher::hash (new_call.fundef); |
1747 | new_call.hash | |
1748 | = iterative_hash_template_arg (new_call.bindings, new_call.hash); | |
1749 | new_call.hash | |
13de99bc | 1750 | = iterative_hash_object (ctx->manifestly_const_eval, new_call.hash); |
12d9ce19 JM |
1751 | |
1752 | /* If we have seen this call before, we are done. */ | |
1753 | maybe_initialize_constexpr_call_table (); | |
1754 | constexpr_call **slot | |
1755 | = constexpr_call_table->find_slot (&new_call, INSERT); | |
1756 | entry = *slot; | |
1757 | if (entry == NULL) | |
1758 | { | |
1759 | /* We need to keep a pointer to the entry, not just the slot, as the | |
1760 | slot can move in the call to cxx_eval_builtin_function_call. */ | |
1761 | *slot = entry = ggc_alloc<constexpr_call> (); | |
1762 | *entry = new_call; | |
1763 | } | |
4727d4c6 | 1764 | /* Calls that are in progress have their result set to NULL, |
12d9ce19 JM |
1765 | so that we can detect circular dependencies. */ |
1766 | else if (entry->result == NULL) | |
1767 | { | |
1768 | if (!ctx->quiet) | |
1769 | error ("call has circular dependency"); | |
1770 | *non_constant_p = true; | |
1771 | entry->result = result = error_mark_node; | |
1772 | } | |
1773 | else | |
1774 | result = entry->result; | |
2d76680f PC |
1775 | } |
1776 | ||
1777 | if (!depth_ok) | |
1778 | { | |
2b3ab879 | 1779 | if (!ctx->quiet) |
84fa214d | 1780 | error ("%<constexpr%> evaluation depth exceeds maximum of %d (use " |
7e7a6ed7 | 1781 | "%<-fconstexpr-depth=%> to increase the maximum)", |
2d76680f PC |
1782 | max_constexpr_depth); |
1783 | *non_constant_p = true; | |
12d9ce19 | 1784 | result = error_mark_node; |
2d76680f PC |
1785 | } |
1786 | else | |
1787 | { | |
de54de93 JM |
1788 | if (result && result != error_mark_node) |
1789 | /* OK */; | |
1790 | else if (!DECL_SAVED_TREE (fun)) | |
1791 | { | |
1792 | /* When at_eof >= 2, cgraph has started throwing away | |
1793 | DECL_SAVED_TREE, so fail quietly. FIXME we get here because of | |
1794 | late code generation for VEC_INIT_EXPR, which needs to be | |
1795 | completely reconsidered. */ | |
1796 | gcc_assert (at_eof >= 2 && ctx->quiet); | |
1797 | *non_constant_p = true; | |
1798 | } | |
1799 | else | |
3e605b20 | 1800 | { |
c0daf32d | 1801 | tree body, parms, res; |
0567dcd2 | 1802 | |
c0daf32d | 1803 | /* Reuse or create a new unshared copy of this function's body. */ |
43574e4f | 1804 | tree copy = get_fundef_copy (new_call.fundef); |
97f3003f JM |
1805 | body = TREE_PURPOSE (copy); |
1806 | parms = TREE_VALUE (copy); | |
1807 | res = TREE_TYPE (copy); | |
0567dcd2 MP |
1808 | |
1809 | /* Associate the bindings with the remapped parms. */ | |
1810 | tree bound = new_call.bindings; | |
1811 | tree remapped = parms; | |
1812 | while (bound) | |
60813a46 | 1813 | { |
0567dcd2 MP |
1814 | tree oparm = TREE_PURPOSE (bound); |
1815 | tree arg = TREE_VALUE (bound); | |
1816 | gcc_assert (DECL_NAME (remapped) == DECL_NAME (oparm)); | |
7f0e23e9 | 1817 | /* Don't share a CONSTRUCTOR that might be changed. */ |
0146e25f | 1818 | arg = unshare_constructor (arg); |
0567dcd2 MP |
1819 | ctx->values->put (remapped, arg); |
1820 | bound = TREE_CHAIN (bound); | |
1821 | remapped = DECL_CHAIN (remapped); | |
60813a46 | 1822 | } |
0567dcd2 MP |
1823 | /* Add the RESULT_DECL to the values map, too. */ |
1824 | tree slot = NULL_TREE; | |
1825 | if (DECL_BY_REFERENCE (res)) | |
60813a46 | 1826 | { |
0567dcd2 MP |
1827 | slot = AGGR_INIT_EXPR_SLOT (t); |
1828 | tree addr = build_address (slot); | |
1829 | addr = build_nop (TREE_TYPE (res), addr); | |
1830 | ctx->values->put (res, addr); | |
1831 | ctx->values->put (slot, NULL_TREE); | |
1832 | } | |
1833 | else | |
1834 | ctx->values->put (res, NULL_TREE); | |
60813a46 | 1835 | |
c0daf32d PP |
1836 | /* Track the callee's evaluated SAVE_EXPRs so that we can forget |
1837 | their values after the call. */ | |
1838 | constexpr_ctx ctx_with_save_exprs = *ctx; | |
0ee28590 | 1839 | auto_vec<tree, 10> save_exprs; |
c0daf32d | 1840 | ctx_with_save_exprs.save_exprs = &save_exprs; |
1e163090 | 1841 | ctx_with_save_exprs.call = &new_call; |
c0daf32d | 1842 | |
0567dcd2 | 1843 | tree jump_target = NULL_TREE; |
c0daf32d | 1844 | cxx_eval_constant_expression (&ctx_with_save_exprs, body, |
0567dcd2 MP |
1845 | lval, non_constant_p, overflow_p, |
1846 | &jump_target); | |
60813a46 | 1847 | |
0567dcd2 MP |
1848 | if (DECL_CONSTRUCTOR_P (fun)) |
1849 | /* This can be null for a subobject constructor call, in | |
1850 | which case what we care about is the initialization | |
1851 | side-effects rather than the value. We could get at the | |
1852 | value by evaluating *this, but we don't bother; there's | |
1853 | no need to put such a call in the hash table. */ | |
1854 | result = lval ? ctx->object : ctx->ctor; | |
1855 | else if (VOID_TYPE_P (TREE_TYPE (res))) | |
1856 | result = void_node; | |
1857 | else | |
1858 | { | |
1859 | result = *ctx->values->get (slot ? slot : res); | |
1860 | if (result == NULL_TREE && !*non_constant_p) | |
60813a46 | 1861 | { |
0567dcd2 | 1862 | if (!ctx->quiet) |
84fa214d | 1863 | error ("%<constexpr%> call flows off the end " |
0567dcd2 MP |
1864 | "of the function"); |
1865 | *non_constant_p = true; | |
60813a46 | 1866 | } |
60813a46 | 1867 | } |
0567dcd2 | 1868 | |
c0daf32d | 1869 | /* Forget the saved values of the callee's SAVE_EXPRs. */ |
0ee28590 JJ |
1870 | unsigned int i; |
1871 | tree save_expr; | |
1872 | FOR_EACH_VEC_ELT (save_exprs, i, save_expr) | |
1873 | ctx_with_save_exprs.values->remove (save_expr); | |
c0daf32d | 1874 | |
0567dcd2 MP |
1875 | /* Remove the parms/result from the values map. Is it worth |
1876 | bothering to do this when the map itself is only live for | |
1877 | one constexpr evaluation? If so, maybe also clear out | |
1878 | other vars from call, maybe in BIND_EXPR handling? */ | |
1879 | ctx->values->remove (res); | |
1880 | if (slot) | |
1881 | ctx->values->remove (slot); | |
1882 | for (tree parm = parms; parm; parm = TREE_CHAIN (parm)) | |
1883 | ctx->values->remove (parm); | |
c0daf32d PP |
1884 | |
1885 | /* Make the unshared function copy we used available for re-use. */ | |
1886 | save_fundef_copy (fun, copy); | |
3e605b20 | 1887 | } |
60813a46 | 1888 | |
2d76680f PC |
1889 | if (result == error_mark_node) |
1890 | *non_constant_p = true; | |
52228180 | 1891 | if (*non_constant_p || *overflow_p) |
12d9ce19 | 1892 | result = error_mark_node; |
0567dcd2 | 1893 | else if (!result) |
60813a46 | 1894 | result = void_node; |
12d9ce19 JM |
1895 | if (entry) |
1896 | entry->result = result; | |
2d76680f PC |
1897 | } |
1898 | ||
f64e0c02 JM |
1899 | /* The result of a constexpr function must be completely initialized. */ |
1900 | if (TREE_CODE (result) == CONSTRUCTOR) | |
ecc57615 | 1901 | clear_no_implicit_zero (result); |
f64e0c02 | 1902 | |
2d76680f | 1903 | pop_cx_call_context (); |
0146e25f | 1904 | return unshare_constructor (result); |
2d76680f PC |
1905 | } |
1906 | ||
1907 | /* FIXME speed this up, it's taking 16% of compile time on sieve testcase. */ | |
1908 | ||
1909 | bool | |
1910 | reduced_constant_expression_p (tree t) | |
1911 | { | |
4930c53e MP |
1912 | if (t == NULL_TREE) |
1913 | return false; | |
1914 | ||
2d76680f PC |
1915 | switch (TREE_CODE (t)) |
1916 | { | |
1917 | case PTRMEM_CST: | |
1918 | /* Even if we can't lower this yet, it's constant. */ | |
1919 | return true; | |
1920 | ||
1921 | case CONSTRUCTOR: | |
1922 | /* And we need to handle PTRMEM_CST wrapped in a CONSTRUCTOR. */ | |
7368cfa4 | 1923 | tree idx, val, field; unsigned HOST_WIDE_INT i; |
e8c48716 | 1924 | if (CONSTRUCTOR_NO_CLEARING (t)) |
6f11ddd8 JM |
1925 | { |
1926 | if (TREE_CODE (TREE_TYPE (t)) == VECTOR_TYPE) | |
1927 | /* An initialized vector would have a VECTOR_CST. */ | |
1928 | return false; | |
1929 | else | |
1930 | field = next_initializable_field (TYPE_FIELDS (TREE_TYPE (t))); | |
1931 | } | |
7368cfa4 JM |
1932 | else |
1933 | field = NULL_TREE; | |
1934 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (t), i, idx, val) | |
125db6a1 | 1935 | { |
4930c53e MP |
1936 | /* If VAL is null, we're in the middle of initializing this |
1937 | element. */ | |
7368cfa4 | 1938 | if (!reduced_constant_expression_p (val)) |
125db6a1 | 1939 | return false; |
7368cfa4 JM |
1940 | if (field) |
1941 | { | |
1942 | if (idx != field) | |
1943 | return false; | |
1944 | field = next_initializable_field (DECL_CHAIN (field)); | |
1945 | } | |
125db6a1 | 1946 | } |
7368cfa4 JM |
1947 | if (field) |
1948 | return false; | |
e8c48716 | 1949 | else if (CONSTRUCTOR_NO_CLEARING (t)) |
7368cfa4 | 1950 | /* All the fields are initialized. */ |
e8c48716 | 1951 | CONSTRUCTOR_NO_CLEARING (t) = false; |
2d76680f PC |
1952 | return true; |
1953 | ||
1954 | default: | |
1955 | /* FIXME are we calling this too much? */ | |
1956 | return initializer_constant_valid_p (t, TREE_TYPE (t)) != NULL_TREE; | |
1957 | } | |
1958 | } | |
1959 | ||
1960 | /* Some expressions may have constant operands but are not constant | |
7d75ea04 JJ |
1961 | themselves, such as 1/0. Call this function to check for that |
1962 | condition. | |
2d76680f PC |
1963 | |
1964 | We only call this in places that require an arithmetic constant, not in | |
1965 | places where we might have a non-constant expression that can be a | |
1966 | component of a constant expression, such as the address of a constexpr | |
1967 | variable that might be dereferenced later. */ | |
1968 | ||
1969 | static bool | |
1970 | verify_constant (tree t, bool allow_non_constant, bool *non_constant_p, | |
1971 | bool *overflow_p) | |
1972 | { | |
1973 | if (!*non_constant_p && !reduced_constant_expression_p (t)) | |
1974 | { | |
1975 | if (!allow_non_constant) | |
1976 | error ("%q+E is not a constant expression", t); | |
1977 | *non_constant_p = true; | |
1978 | } | |
1979 | if (TREE_OVERFLOW_P (t)) | |
1980 | { | |
1981 | if (!allow_non_constant) | |
1982 | { | |
1983 | permerror (input_location, "overflow in constant expression"); | |
1984 | /* If we're being permissive (and are in an enforcing | |
1985 | context), ignore the overflow. */ | |
1986 | if (flag_permissive) | |
1987 | return *non_constant_p; | |
1988 | } | |
1989 | *overflow_p = true; | |
1990 | } | |
1991 | return *non_constant_p; | |
1992 | } | |
1993 | ||
253a921b MP |
1994 | /* Check whether the shift operation with code CODE and type TYPE on LHS |
1995 | and RHS is undefined. If it is, give an error with an explanation, | |
1996 | and return true; return false otherwise. */ | |
1997 | ||
1998 | static bool | |
1999 | cxx_eval_check_shift_p (location_t loc, const constexpr_ctx *ctx, | |
2000 | enum tree_code code, tree type, tree lhs, tree rhs) | |
2001 | { | |
2002 | if ((code != LSHIFT_EXPR && code != RSHIFT_EXPR) | |
2003 | || TREE_CODE (lhs) != INTEGER_CST | |
2004 | || TREE_CODE (rhs) != INTEGER_CST) | |
2005 | return false; | |
2006 | ||
2007 | tree lhstype = TREE_TYPE (lhs); | |
2008 | unsigned HOST_WIDE_INT uprec = TYPE_PRECISION (TREE_TYPE (lhs)); | |
2009 | ||
2010 | /* [expr.shift] The behavior is undefined if the right operand | |
2011 | is negative, or greater than or equal to the length in bits | |
2012 | of the promoted left operand. */ | |
2013 | if (tree_int_cst_sgn (rhs) == -1) | |
2014 | { | |
2015 | if (!ctx->quiet) | |
5342156c MP |
2016 | permerror (loc, "right operand of shift expression %q+E is negative", |
2017 | build2_loc (loc, code, type, lhs, rhs)); | |
2018 | return (!flag_permissive || ctx->quiet); | |
253a921b MP |
2019 | } |
2020 | if (compare_tree_int (rhs, uprec) >= 0) | |
2021 | { | |
2022 | if (!ctx->quiet) | |
5342156c MP |
2023 | permerror (loc, "right operand of shift expression %q+E is >= than " |
2024 | "the precision of the left operand", | |
2025 | build2_loc (loc, code, type, lhs, rhs)); | |
2026 | return (!flag_permissive || ctx->quiet); | |
253a921b MP |
2027 | } |
2028 | ||
2029 | /* The value of E1 << E2 is E1 left-shifted E2 bit positions; [...] | |
2030 | if E1 has a signed type and non-negative value, and E1x2^E2 is | |
2031 | representable in the corresponding unsigned type of the result type, | |
2032 | then that value, converted to the result type, is the resulting value; | |
8ee09943 JJ |
2033 | otherwise, the behavior is undefined. |
2034 | For C++2a: | |
2035 | The value of E1 << E2 is the unique value congruent to E1 x 2^E2 modulo | |
2036 | 2^N, where N is the range exponent of the type of the result. */ | |
2037 | if (code == LSHIFT_EXPR | |
2038 | && !TYPE_UNSIGNED (lhstype) | |
2039 | && cxx_dialect >= cxx11 | |
2040 | && cxx_dialect < cxx2a) | |
253a921b MP |
2041 | { |
2042 | if (tree_int_cst_sgn (lhs) == -1) | |
2043 | { | |
2044 | if (!ctx->quiet) | |
5342156c MP |
2045 | permerror (loc, |
2046 | "left operand of shift expression %q+E is negative", | |
2047 | build2_loc (loc, code, type, lhs, rhs)); | |
2048 | return (!flag_permissive || ctx->quiet); | |
253a921b MP |
2049 | } |
2050 | /* For signed x << y the following: | |
2051 | (unsigned) x >> ((prec (lhs) - 1) - y) | |
2052 | if > 1, is undefined. The right-hand side of this formula | |
2053 | is the highest bit of the LHS that can be set (starting from 0), | |
2054 | so that the shift doesn't overflow. We then right-shift the LHS | |
2055 | to see whether any other bit is set making the original shift | |
2056 | undefined -- the result is not representable in the corresponding | |
2057 | unsigned type. */ | |
2058 | tree t = build_int_cst (unsigned_type_node, uprec - 1); | |
2059 | t = fold_build2 (MINUS_EXPR, unsigned_type_node, t, rhs); | |
2060 | tree ulhs = fold_convert (unsigned_type_for (lhstype), lhs); | |
2061 | t = fold_build2 (RSHIFT_EXPR, TREE_TYPE (ulhs), ulhs, t); | |
2062 | if (tree_int_cst_lt (integer_one_node, t)) | |
2063 | { | |
2064 | if (!ctx->quiet) | |
5342156c MP |
2065 | permerror (loc, "shift expression %q+E overflows", |
2066 | build2_loc (loc, code, type, lhs, rhs)); | |
2067 | return (!flag_permissive || ctx->quiet); | |
253a921b MP |
2068 | } |
2069 | } | |
2070 | return false; | |
2071 | } | |
2072 | ||
2d76680f PC |
2073 | /* Subroutine of cxx_eval_constant_expression. |
2074 | Attempt to reduce the unary expression tree T to a compile time value. | |
2075 | If successful, return the value. Otherwise issue a diagnostic | |
2076 | and return error_mark_node. */ | |
2077 | ||
2078 | static tree | |
3e605b20 | 2079 | cxx_eval_unary_expression (const constexpr_ctx *ctx, tree t, |
12d9ce19 | 2080 | bool /*lval*/, |
2d76680f PC |
2081 | bool *non_constant_p, bool *overflow_p) |
2082 | { | |
2083 | tree r; | |
2084 | tree orig_arg = TREE_OPERAND (t, 0); | |
12d9ce19 JM |
2085 | tree arg = cxx_eval_constant_expression (ctx, orig_arg, /*lval*/false, |
2086 | non_constant_p, overflow_p); | |
2d76680f | 2087 | VERIFY_CONSTANT (arg); |
f899317e JM |
2088 | location_t loc = EXPR_LOCATION (t); |
2089 | enum tree_code code = TREE_CODE (t); | |
2090 | tree type = TREE_TYPE (t); | |
2091 | r = fold_unary_loc (loc, code, type, arg); | |
2092 | if (r == NULL_TREE) | |
2093 | { | |
2094 | if (arg == orig_arg) | |
2095 | r = t; | |
2096 | else | |
2097 | r = build1_loc (loc, code, type, arg); | |
2098 | } | |
2d76680f PC |
2099 | VERIFY_CONSTANT (r); |
2100 | return r; | |
2101 | } | |
2102 | ||
ea8661cd JJ |
2103 | /* Helper function for cxx_eval_binary_expression. Try to optimize |
2104 | original POINTER_PLUS_EXPR T, LHS p+ RHS, return NULL_TREE if the | |
2105 | generic folding should be used. */ | |
2106 | ||
2107 | static tree | |
2108 | cxx_fold_pointer_plus_expression (const constexpr_ctx *ctx, tree t, | |
2109 | tree lhs, tree rhs, bool *non_constant_p, | |
2110 | bool *overflow_p) | |
2111 | { | |
2112 | STRIP_NOPS (lhs); | |
2113 | if (TREE_CODE (lhs) != ADDR_EXPR) | |
2114 | return NULL_TREE; | |
2115 | ||
2116 | lhs = TREE_OPERAND (lhs, 0); | |
2117 | ||
2118 | /* &A[i] p+ j => &A[i + j] */ | |
2119 | if (TREE_CODE (lhs) == ARRAY_REF | |
2120 | && TREE_CODE (TREE_OPERAND (lhs, 1)) == INTEGER_CST | |
2121 | && TREE_CODE (rhs) == INTEGER_CST | |
2122 | && TYPE_SIZE_UNIT (TREE_TYPE (lhs)) | |
2123 | && TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (lhs))) == INTEGER_CST) | |
2124 | { | |
2125 | tree orig_type = TREE_TYPE (t); | |
2126 | location_t loc = EXPR_LOCATION (t); | |
2127 | tree type = TREE_TYPE (lhs); | |
2128 | ||
2129 | t = fold_convert_loc (loc, ssizetype, TREE_OPERAND (lhs, 1)); | |
2130 | tree nelts = array_type_nelts_top (TREE_TYPE (TREE_OPERAND (lhs, 0))); | |
2131 | nelts = cxx_eval_constant_expression (ctx, nelts, false, non_constant_p, | |
2132 | overflow_p); | |
2133 | if (*non_constant_p) | |
2134 | return NULL_TREE; | |
2135 | /* Don't fold an out-of-bound access. */ | |
2136 | if (!tree_int_cst_le (t, nelts)) | |
2137 | return NULL_TREE; | |
2138 | rhs = cp_fold_convert (ssizetype, rhs); | |
2139 | /* Don't fold if rhs can't be divided exactly by TYPE_SIZE_UNIT. | |
2140 | constexpr int A[1]; ... (char *)&A[0] + 1 */ | |
2141 | if (!integer_zerop (fold_build2_loc (loc, TRUNC_MOD_EXPR, sizetype, | |
2142 | rhs, TYPE_SIZE_UNIT (type)))) | |
2143 | return NULL_TREE; | |
2144 | /* Make sure to treat the second operand of POINTER_PLUS_EXPR | |
2145 | as signed. */ | |
2146 | rhs = fold_build2_loc (loc, EXACT_DIV_EXPR, ssizetype, rhs, | |
2147 | TYPE_SIZE_UNIT (type)); | |
2148 | t = size_binop_loc (loc, PLUS_EXPR, rhs, t); | |
2149 | t = build4_loc (loc, ARRAY_REF, type, TREE_OPERAND (lhs, 0), | |
2150 | t, NULL_TREE, NULL_TREE); | |
2151 | t = cp_build_addr_expr (t, tf_warning_or_error); | |
2152 | t = cp_fold_convert (orig_type, t); | |
2153 | return cxx_eval_constant_expression (ctx, t, /*lval*/false, | |
2154 | non_constant_p, overflow_p); | |
2155 | } | |
2156 | ||
2157 | return NULL_TREE; | |
2158 | } | |
2159 | ||
2d76680f PC |
2160 | /* Subroutine of cxx_eval_constant_expression. |
2161 | Like cxx_eval_unary_expression, except for binary expressions. */ | |
2162 | ||
2163 | static tree | |
3e605b20 | 2164 | cxx_eval_binary_expression (const constexpr_ctx *ctx, tree t, |
12d9ce19 | 2165 | bool /*lval*/, |
2d76680f PC |
2166 | bool *non_constant_p, bool *overflow_p) |
2167 | { | |
618d6c1c | 2168 | tree r = NULL_TREE; |
2d76680f PC |
2169 | tree orig_lhs = TREE_OPERAND (t, 0); |
2170 | tree orig_rhs = TREE_OPERAND (t, 1); | |
2171 | tree lhs, rhs; | |
12d9ce19 | 2172 | lhs = cxx_eval_constant_expression (ctx, orig_lhs, /*lval*/false, |
5a804683 | 2173 | non_constant_p, overflow_p); |
c8a66fc9 JM |
2174 | /* Don't VERIFY_CONSTANT here, it's unnecessary and will break pointer |
2175 | subtraction. */ | |
2176 | if (*non_constant_p) | |
2177 | return t; | |
12d9ce19 | 2178 | rhs = cxx_eval_constant_expression (ctx, orig_rhs, /*lval*/false, |
5a804683 | 2179 | non_constant_p, overflow_p); |
c8a66fc9 JM |
2180 | if (*non_constant_p) |
2181 | return t; | |
f899317e JM |
2182 | |
2183 | location_t loc = EXPR_LOCATION (t); | |
2184 | enum tree_code code = TREE_CODE (t); | |
2185 | tree type = TREE_TYPE (t); | |
618d6c1c PP |
2186 | |
2187 | if (code == EQ_EXPR || code == NE_EXPR) | |
2188 | { | |
2189 | bool is_code_eq = (code == EQ_EXPR); | |
2190 | ||
2191 | if (TREE_CODE (lhs) == PTRMEM_CST | |
2192 | && TREE_CODE (rhs) == PTRMEM_CST) | |
9b0607de JM |
2193 | { |
2194 | tree lmem = PTRMEM_CST_MEMBER (lhs); | |
2195 | tree rmem = PTRMEM_CST_MEMBER (rhs); | |
2196 | bool eq; | |
2197 | if (TREE_CODE (lmem) == TREE_CODE (rmem) | |
2198 | && TREE_CODE (lmem) == FIELD_DECL | |
2199 | && TREE_CODE (DECL_CONTEXT (lmem)) == UNION_TYPE | |
2200 | && same_type_p (DECL_CONTEXT (lmem), | |
2201 | DECL_CONTEXT (rmem))) | |
2202 | /* If both refer to (possibly different) members of the same union | |
2203 | (12.3), they compare equal. */ | |
2204 | eq = true; | |
2205 | else | |
2206 | eq = cp_tree_equal (lhs, rhs); | |
2207 | r = constant_boolean_node (eq == is_code_eq, type); | |
2208 | } | |
618d6c1c PP |
2209 | else if ((TREE_CODE (lhs) == PTRMEM_CST |
2210 | || TREE_CODE (rhs) == PTRMEM_CST) | |
2211 | && (null_member_pointer_value_p (lhs) | |
2212 | || null_member_pointer_value_p (rhs))) | |
2213 | r = constant_boolean_node (!is_code_eq, type); | |
dd5dda56 JM |
2214 | else if (TREE_CODE (lhs) == PTRMEM_CST) |
2215 | lhs = cplus_expand_constant (lhs); | |
2216 | else if (TREE_CODE (rhs) == PTRMEM_CST) | |
2217 | rhs = cplus_expand_constant (rhs); | |
618d6c1c | 2218 | } |
8bada5cd MS |
2219 | if (code == POINTER_PLUS_EXPR && !*non_constant_p |
2220 | && integer_zerop (lhs) && !integer_zerop (rhs)) | |
2221 | { | |
2222 | if (!ctx->quiet) | |
2223 | error ("arithmetic involving a null pointer in %qE", lhs); | |
bf533db8 | 2224 | *non_constant_p = true; |
8bada5cd MS |
2225 | return t; |
2226 | } | |
ea8661cd JJ |
2227 | else if (code == POINTER_PLUS_EXPR) |
2228 | r = cxx_fold_pointer_plus_expression (ctx, t, lhs, rhs, non_constant_p, | |
2229 | overflow_p); | |
618d6c1c PP |
2230 | |
2231 | if (r == NULL_TREE) | |
2232 | r = fold_binary_loc (loc, code, type, lhs, rhs); | |
2233 | ||
f899317e JM |
2234 | if (r == NULL_TREE) |
2235 | { | |
2236 | if (lhs == orig_lhs && rhs == orig_rhs) | |
2237 | r = t; | |
2238 | else | |
2239 | r = build2_loc (loc, code, type, lhs, rhs); | |
2240 | } | |
253a921b MP |
2241 | else if (cxx_eval_check_shift_p (loc, ctx, code, type, lhs, rhs)) |
2242 | *non_constant_p = true; | |
c8a66fc9 JM |
2243 | /* Don't VERIFY_CONSTANT if this might be dealing with a pointer to |
2244 | a local array in a constexpr function. */ | |
71a93b08 | 2245 | bool ptr = INDIRECT_TYPE_P (TREE_TYPE (lhs)); |
caee690e | 2246 | if (!ptr) |
134efa82 | 2247 | VERIFY_CONSTANT (r); |
2d76680f PC |
2248 | return r; |
2249 | } | |
2250 | ||
2251 | /* Subroutine of cxx_eval_constant_expression. | |
2252 | Attempt to evaluate condition expressions. Dead branches are not | |
2253 | looked into. */ | |
2254 | ||
2255 | static tree | |
3e605b20 | 2256 | cxx_eval_conditional_expression (const constexpr_ctx *ctx, tree t, |
92a596e8 | 2257 | bool lval, |
56632b27 JM |
2258 | bool *non_constant_p, bool *overflow_p, |
2259 | tree *jump_target) | |
2d76680f | 2260 | { |
3e605b20 | 2261 | tree val = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), |
12d9ce19 | 2262 | /*lval*/false, |
5a804683 | 2263 | non_constant_p, overflow_p); |
2d76680f PC |
2264 | VERIFY_CONSTANT (val); |
2265 | /* Don't VERIFY_CONSTANT the other operands. */ | |
2266 | if (integer_zerop (val)) | |
43574e4f JJ |
2267 | val = TREE_OPERAND (t, 2); |
2268 | else | |
2269 | val = TREE_OPERAND (t, 1); | |
2270 | if (TREE_CODE (t) == IF_STMT && !val) | |
2271 | val = void_node; | |
2272 | return cxx_eval_constant_expression (ctx, val, lval, non_constant_p, | |
2273 | overflow_p, jump_target); | |
2d76680f PC |
2274 | } |
2275 | ||
f370e36d JJ |
2276 | /* Subroutine of cxx_eval_constant_expression. |
2277 | Attempt to evaluate vector condition expressions. Unlike | |
2278 | cxx_eval_conditional_expression, VEC_COND_EXPR acts like a normal | |
2279 | ternary arithmetics operation, where all 3 arguments have to be | |
2280 | evaluated as constants and then folding computes the result from | |
2281 | them. */ | |
2282 | ||
2283 | static tree | |
2284 | cxx_eval_vector_conditional_expression (const constexpr_ctx *ctx, tree t, | |
2285 | bool *non_constant_p, bool *overflow_p) | |
2286 | { | |
2287 | tree arg1 = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), | |
2288 | /*lval*/false, | |
2289 | non_constant_p, overflow_p); | |
2290 | VERIFY_CONSTANT (arg1); | |
2291 | tree arg2 = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), | |
2292 | /*lval*/false, | |
2293 | non_constant_p, overflow_p); | |
2294 | VERIFY_CONSTANT (arg2); | |
2295 | tree arg3 = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 2), | |
2296 | /*lval*/false, | |
2297 | non_constant_p, overflow_p); | |
2298 | VERIFY_CONSTANT (arg3); | |
2299 | location_t loc = EXPR_LOCATION (t); | |
2300 | tree type = TREE_TYPE (t); | |
2301 | tree r = fold_ternary_loc (loc, VEC_COND_EXPR, type, arg1, arg2, arg3); | |
2302 | if (r == NULL_TREE) | |
2303 | { | |
2304 | if (arg1 == TREE_OPERAND (t, 0) | |
2305 | && arg2 == TREE_OPERAND (t, 1) | |
2306 | && arg3 == TREE_OPERAND (t, 2)) | |
2307 | r = t; | |
2308 | else | |
2309 | r = build3_loc (loc, VEC_COND_EXPR, type, arg1, arg2, arg3); | |
2310 | } | |
2311 | VERIFY_CONSTANT (r); | |
2312 | return r; | |
2313 | } | |
2314 | ||
ceaaf873 JM |
2315 | /* Returns less than, equal to, or greater than zero if KEY is found to be |
2316 | less than, to match, or to be greater than the constructor_elt's INDEX. */ | |
2317 | ||
2318 | static int | |
2319 | array_index_cmp (tree key, tree index) | |
2320 | { | |
2321 | gcc_assert (TREE_CODE (key) == INTEGER_CST); | |
2322 | ||
2323 | switch (TREE_CODE (index)) | |
2324 | { | |
2325 | case INTEGER_CST: | |
2326 | return tree_int_cst_compare (key, index); | |
2327 | case RANGE_EXPR: | |
2328 | { | |
2329 | tree lo = TREE_OPERAND (index, 0); | |
2330 | tree hi = TREE_OPERAND (index, 1); | |
2331 | if (tree_int_cst_lt (key, lo)) | |
2332 | return -1; | |
2333 | else if (tree_int_cst_lt (hi, key)) | |
2334 | return 1; | |
2335 | else | |
2336 | return 0; | |
2337 | } | |
2338 | default: | |
2339 | gcc_unreachable (); | |
2340 | } | |
2341 | } | |
2342 | ||
2343 | /* Returns the index of the constructor_elt of ARY which matches DINDEX, or -1 | |
2344 | if none. If INSERT is true, insert a matching element rather than fail. */ | |
2345 | ||
2346 | static HOST_WIDE_INT | |
582d2481 | 2347 | find_array_ctor_elt (tree ary, tree dindex, bool insert) |
ceaaf873 JM |
2348 | { |
2349 | if (tree_int_cst_sgn (dindex) < 0) | |
2350 | return -1; | |
2351 | ||
2352 | unsigned HOST_WIDE_INT i = tree_to_uhwi (dindex); | |
2353 | vec<constructor_elt, va_gc> *elts = CONSTRUCTOR_ELTS (ary); | |
2354 | unsigned HOST_WIDE_INT len = vec_safe_length (elts); | |
2355 | ||
2356 | unsigned HOST_WIDE_INT end = len; | |
2357 | unsigned HOST_WIDE_INT begin = 0; | |
2358 | ||
2359 | /* If the last element of the CONSTRUCTOR has its own index, we can assume | |
2360 | that the same is true of the other elements and index directly. */ | |
2361 | if (end > 0) | |
2362 | { | |
fe217ba0 | 2363 | tree cindex = (*elts)[end - 1].index; |
ceaaf873 | 2364 | if (TREE_CODE (cindex) == INTEGER_CST |
fe217ba0 | 2365 | && compare_tree_int (cindex, end - 1) == 0) |
ceaaf873 JM |
2366 | { |
2367 | if (i < end) | |
2368 | return i; | |
2369 | else | |
2370 | begin = end; | |
2371 | } | |
2372 | } | |
2373 | ||
2374 | /* Otherwise, find a matching index by means of a binary search. */ | |
2375 | while (begin != end) | |
2376 | { | |
2377 | unsigned HOST_WIDE_INT middle = (begin + end) / 2; | |
a7ccb9e7 JM |
2378 | constructor_elt &elt = (*elts)[middle]; |
2379 | tree idx = elt.index; | |
ceaaf873 | 2380 | |
a7ccb9e7 | 2381 | int cmp = array_index_cmp (dindex, idx); |
ceaaf873 JM |
2382 | if (cmp < 0) |
2383 | end = middle; | |
2384 | else if (cmp > 0) | |
2385 | begin = middle + 1; | |
2386 | else | |
a7ccb9e7 JM |
2387 | { |
2388 | if (insert && TREE_CODE (idx) == RANGE_EXPR) | |
2389 | { | |
2390 | /* We need to split the range. */ | |
2391 | constructor_elt e; | |
2392 | tree lo = TREE_OPERAND (idx, 0); | |
2393 | tree hi = TREE_OPERAND (idx, 1); | |
fe217ba0 JJ |
2394 | tree value = elt.value; |
2395 | dindex = fold_convert (sizetype, dindex); | |
a7ccb9e7 JM |
2396 | if (tree_int_cst_lt (lo, dindex)) |
2397 | { | |
2398 | /* There are still some lower elts; shorten the range. */ | |
2399 | tree new_hi = int_const_binop (MINUS_EXPR, dindex, | |
2400 | size_one_node); | |
2401 | if (tree_int_cst_equal (lo, new_hi)) | |
2402 | /* Only one element left, no longer a range. */ | |
2403 | elt.index = lo; | |
2404 | else | |
2405 | TREE_OPERAND (idx, 1) = new_hi; | |
2406 | /* Append the element we want to insert. */ | |
2407 | ++middle; | |
2408 | e.index = dindex; | |
fe217ba0 | 2409 | e.value = unshare_constructor (value); |
a7ccb9e7 JM |
2410 | vec_safe_insert (CONSTRUCTOR_ELTS (ary), middle, e); |
2411 | } | |
2412 | else | |
2413 | /* No lower elts, the range elt is now ours. */ | |
2414 | elt.index = dindex; | |
2415 | ||
2416 | if (tree_int_cst_lt (dindex, hi)) | |
2417 | { | |
2418 | /* There are still some higher elts; append a range. */ | |
2419 | tree new_lo = int_const_binop (PLUS_EXPR, dindex, | |
2420 | size_one_node); | |
2421 | if (tree_int_cst_equal (new_lo, hi)) | |
2422 | e.index = hi; | |
2423 | else | |
2424 | e.index = build2 (RANGE_EXPR, sizetype, new_lo, hi); | |
fe217ba0 JJ |
2425 | e.value = unshare_constructor (value); |
2426 | vec_safe_insert (CONSTRUCTOR_ELTS (ary), middle + 1, e); | |
a7ccb9e7 JM |
2427 | } |
2428 | } | |
2429 | return middle; | |
2430 | } | |
ceaaf873 JM |
2431 | } |
2432 | ||
2433 | if (insert) | |
2434 | { | |
2435 | constructor_elt e = { dindex, NULL_TREE }; | |
2436 | vec_safe_insert (CONSTRUCTOR_ELTS (ary), end, e); | |
2437 | return end; | |
2438 | } | |
2439 | ||
2440 | return -1; | |
2441 | } | |
2442 | ||
abdc16c8 MS |
2443 | /* Under the control of CTX, issue a detailed diagnostic for |
2444 | an out-of-bounds subscript INDEX into the expression ARRAY. */ | |
2445 | ||
2446 | static void | |
2447 | diag_array_subscript (const constexpr_ctx *ctx, tree array, tree index) | |
2448 | { | |
2449 | if (!ctx->quiet) | |
2450 | { | |
2451 | tree arraytype = TREE_TYPE (array); | |
2452 | ||
2453 | /* Convert the unsigned array subscript to a signed integer to avoid | |
2454 | printing huge numbers for small negative values. */ | |
2455 | tree sidx = fold_convert (ssizetype, index); | |
2456 | if (DECL_P (array)) | |
2457 | { | |
08b3748c JJ |
2458 | if (TYPE_DOMAIN (arraytype)) |
2459 | error ("array subscript value %qE is outside the bounds " | |
2460 | "of array %qD of type %qT", sidx, array, arraytype); | |
2461 | else | |
2462 | error ("non-zero array subscript %qE is used with array %qD of " | |
2463 | "type %qT with unknown bounds", sidx, array, arraytype); | |
abdc16c8 MS |
2464 | inform (DECL_SOURCE_LOCATION (array), "declared here"); |
2465 | } | |
08b3748c | 2466 | else if (TYPE_DOMAIN (arraytype)) |
abdc16c8 MS |
2467 | error ("array subscript value %qE is outside the bounds " |
2468 | "of array type %qT", sidx, arraytype); | |
08b3748c JJ |
2469 | else |
2470 | error ("non-zero array subscript %qE is used with array of type %qT " | |
2471 | "with unknown bounds", sidx, arraytype); | |
abdc16c8 MS |
2472 | } |
2473 | } | |
ceaaf873 | 2474 | |
74f8705e MP |
2475 | /* Return the number of elements for TYPE (which is an ARRAY_TYPE or |
2476 | a VECTOR_TYPE). */ | |
2477 | ||
2478 | static tree | |
2479 | get_array_or_vector_nelts (const constexpr_ctx *ctx, tree type, | |
2480 | bool *non_constant_p, bool *overflow_p) | |
2481 | { | |
2482 | tree nelts; | |
2483 | if (TREE_CODE (type) == ARRAY_TYPE) | |
2484 | { | |
2485 | if (TYPE_DOMAIN (type)) | |
2486 | nelts = array_type_nelts_top (type); | |
2487 | else | |
2488 | nelts = size_zero_node; | |
2489 | } | |
2490 | else if (VECTOR_TYPE_P (type)) | |
2491 | nelts = size_int (TYPE_VECTOR_SUBPARTS (type)); | |
2492 | else | |
2493 | gcc_unreachable (); | |
2494 | ||
2495 | /* For VLAs, the number of elements won't be an integer constant. */ | |
2496 | nelts = cxx_eval_constant_expression (ctx, nelts, false, | |
2497 | non_constant_p, overflow_p); | |
2498 | return nelts; | |
2499 | } | |
2500 | ||
d6b46fca NS |
2501 | /* Extract element INDEX consisting of CHARS_PER_ELT chars from |
2502 | STRING_CST STRING. */ | |
2503 | ||
2504 | static tree | |
2505 | extract_string_elt (tree string, unsigned chars_per_elt, unsigned index) | |
2506 | { | |
2507 | tree type = cv_unqualified (TREE_TYPE (TREE_TYPE (string))); | |
2508 | tree r; | |
2509 | ||
2510 | if (chars_per_elt == 1) | |
2511 | r = build_int_cst (type, TREE_STRING_POINTER (string)[index]); | |
2512 | else | |
2513 | { | |
2514 | const unsigned char *ptr | |
2515 | = ((const unsigned char *)TREE_STRING_POINTER (string) | |
2516 | + index * chars_per_elt); | |
2517 | r = native_interpret_expr (type, ptr, chars_per_elt); | |
2518 | } | |
2519 | return r; | |
2520 | } | |
2521 | ||
2d76680f PC |
2522 | /* Subroutine of cxx_eval_constant_expression. |
2523 | Attempt to reduce a reference to an array slot. */ | |
2524 | ||
2525 | static tree | |
3e605b20 | 2526 | cxx_eval_array_reference (const constexpr_ctx *ctx, tree t, |
92a596e8 | 2527 | bool lval, |
2d76680f PC |
2528 | bool *non_constant_p, bool *overflow_p) |
2529 | { | |
2530 | tree oldary = TREE_OPERAND (t, 0); | |
3e605b20 | 2531 | tree ary = cxx_eval_constant_expression (ctx, oldary, |
92a596e8 | 2532 | lval, |
5a804683 | 2533 | non_constant_p, overflow_p); |
2d76680f | 2534 | tree index, oldidx; |
bc2a38df JJ |
2535 | HOST_WIDE_INT i = 0; |
2536 | tree elem_type = NULL_TREE; | |
2537 | unsigned len = 0, elem_nchars = 1; | |
2d76680f PC |
2538 | if (*non_constant_p) |
2539 | return t; | |
2540 | oldidx = TREE_OPERAND (t, 1); | |
3e605b20 | 2541 | index = cxx_eval_constant_expression (ctx, oldidx, |
2b3ab879 | 2542 | false, |
5a804683 | 2543 | non_constant_p, overflow_p); |
2d76680f | 2544 | VERIFY_CONSTANT (index); |
bc2a38df | 2545 | if (!lval) |
2d76680f | 2546 | { |
bc2a38df JJ |
2547 | elem_type = TREE_TYPE (TREE_TYPE (ary)); |
2548 | if (TREE_CODE (ary) == VIEW_CONVERT_EXPR | |
2549 | && VECTOR_TYPE_P (TREE_TYPE (TREE_OPERAND (ary, 0))) | |
2550 | && TREE_TYPE (t) == TREE_TYPE (TREE_TYPE (TREE_OPERAND (ary, 0)))) | |
2551 | ary = TREE_OPERAND (ary, 0); | |
2552 | if (TREE_CODE (ary) == CONSTRUCTOR) | |
2553 | len = CONSTRUCTOR_NELTS (ary); | |
2554 | else if (TREE_CODE (ary) == STRING_CST) | |
2555 | { | |
2556 | elem_nchars = (TYPE_PRECISION (elem_type) | |
2557 | / TYPE_PRECISION (char_type_node)); | |
2558 | len = (unsigned) TREE_STRING_LENGTH (ary) / elem_nchars; | |
2559 | } | |
2560 | else if (TREE_CODE (ary) == VECTOR_CST) | |
928686b1 RS |
2561 | /* We don't create variable-length VECTOR_CSTs. */ |
2562 | len = VECTOR_CST_NELTS (ary).to_constant (); | |
bc2a38df JJ |
2563 | else |
2564 | { | |
2565 | /* We can't do anything with other tree codes, so use | |
2566 | VERIFY_CONSTANT to complain and fail. */ | |
2567 | VERIFY_CONSTANT (ary); | |
2568 | gcc_unreachable (); | |
2569 | } | |
3b9997bb | 2570 | |
bc2a38df JJ |
2571 | if (!tree_fits_shwi_p (index) |
2572 | || (i = tree_to_shwi (index)) < 0) | |
2573 | { | |
2574 | diag_array_subscript (ctx, ary, index); | |
2575 | *non_constant_p = true; | |
2576 | return t; | |
2577 | } | |
ceaaf873 JM |
2578 | } |
2579 | ||
74f8705e MP |
2580 | tree nelts = get_array_or_vector_nelts (ctx, TREE_TYPE (ary), non_constant_p, |
2581 | overflow_p); | |
5453bfed | 2582 | VERIFY_CONSTANT (nelts); |
3bb43119 JJ |
2583 | if ((lval |
2584 | ? !tree_int_cst_le (index, nelts) | |
2585 | : !tree_int_cst_lt (index, nelts)) | |
2586 | || tree_int_cst_sgn (index) < 0) | |
5453bfed | 2587 | { |
abdc16c8 | 2588 | diag_array_subscript (ctx, ary, index); |
5453bfed MP |
2589 | *non_constant_p = true; |
2590 | return t; | |
2591 | } | |
2592 | ||
bc2a38df JJ |
2593 | if (lval && ary == oldary && index == oldidx) |
2594 | return t; | |
2595 | else if (lval) | |
2596 | return build4 (ARRAY_REF, TREE_TYPE (t), ary, index, NULL, NULL); | |
2597 | ||
ceaaf873 JM |
2598 | bool found; |
2599 | if (TREE_CODE (ary) == CONSTRUCTOR) | |
2600 | { | |
2601 | HOST_WIDE_INT ix = find_array_ctor_elt (ary, index); | |
2602 | found = (ix >= 0); | |
2603 | if (found) | |
2604 | i = ix; | |
3b9997bb | 2605 | } |
ceaaf873 JM |
2606 | else |
2607 | found = (i < len); | |
3b9997bb | 2608 | |
fd2bfee5 JM |
2609 | if (found) |
2610 | { | |
2611 | tree r; | |
2612 | if (TREE_CODE (ary) == CONSTRUCTOR) | |
2613 | r = (*CONSTRUCTOR_ELTS (ary))[i].value; | |
2614 | else if (TREE_CODE (ary) == VECTOR_CST) | |
2615 | r = VECTOR_CST_ELT (ary, i); | |
fd2bfee5 | 2616 | else |
d6b46fca NS |
2617 | r = extract_string_elt (ary, elem_nchars, i); |
2618 | ||
fd2bfee5 JM |
2619 | if (r) |
2620 | /* Don't VERIFY_CONSTANT here. */ | |
2621 | return r; | |
2d76680f | 2622 | |
fd2bfee5 | 2623 | /* Otherwise the element doesn't have a value yet. */ |
2d76680f | 2624 | } |
3b9997bb | 2625 | |
fd2bfee5 JM |
2626 | /* Not found. */ |
2627 | ||
2628 | if (TREE_CODE (ary) == CONSTRUCTOR | |
e8c48716 | 2629 | && CONSTRUCTOR_NO_CLEARING (ary)) |
2d76680f | 2630 | { |
fd2bfee5 JM |
2631 | /* 'ary' is part of the aggregate initializer we're currently |
2632 | building; if there's no initializer for this element yet, | |
2633 | that's an error. */ | |
2634 | if (!ctx->quiet) | |
2635 | error ("accessing uninitialized array element"); | |
2636 | *non_constant_p = true; | |
2637 | return t; | |
2d76680f | 2638 | } |
fd2bfee5 JM |
2639 | |
2640 | /* If it's within the array bounds but doesn't have an explicit | |
2641 | initializer, it's value-initialized. */ | |
2642 | tree val = build_value_init (elem_type, tf_warning_or_error); | |
2643 | return cxx_eval_constant_expression (ctx, val, lval, non_constant_p, | |
2644 | overflow_p); | |
2d76680f PC |
2645 | } |
2646 | ||
2647 | /* Subroutine of cxx_eval_constant_expression. | |
2648 | Attempt to reduce a field access of a value of class type. */ | |
2649 | ||
2650 | static tree | |
3e605b20 | 2651 | cxx_eval_component_reference (const constexpr_ctx *ctx, tree t, |
92a596e8 | 2652 | bool lval, |
2d76680f PC |
2653 | bool *non_constant_p, bool *overflow_p) |
2654 | { | |
2655 | unsigned HOST_WIDE_INT i; | |
2656 | tree field; | |
2657 | tree value; | |
2658 | tree part = TREE_OPERAND (t, 1); | |
2659 | tree orig_whole = TREE_OPERAND (t, 0); | |
3e605b20 | 2660 | tree whole = cxx_eval_constant_expression (ctx, orig_whole, |
92a596e8 | 2661 | lval, |
5a804683 | 2662 | non_constant_p, overflow_p); |
a7f8415c | 2663 | if (INDIRECT_REF_P (whole) |
bf533db8 JJ |
2664 | && integer_zerop (TREE_OPERAND (whole, 0))) |
2665 | { | |
2666 | if (!ctx->quiet) | |
2667 | error ("dereferencing a null pointer in %qE", orig_whole); | |
2668 | *non_constant_p = true; | |
2669 | return t; | |
2670 | } | |
8bada5cd | 2671 | |
dcdbc004 JM |
2672 | if (TREE_CODE (whole) == PTRMEM_CST) |
2673 | whole = cplus_expand_constant (whole); | |
2d76680f PC |
2674 | if (whole == orig_whole) |
2675 | return t; | |
92a596e8 | 2676 | if (lval) |
2d76680f PC |
2677 | return fold_build3 (COMPONENT_REF, TREE_TYPE (t), |
2678 | whole, part, NULL_TREE); | |
2679 | /* Don't VERIFY_CONSTANT here; we only want to check that we got a | |
2680 | CONSTRUCTOR. */ | |
2681 | if (!*non_constant_p && TREE_CODE (whole) != CONSTRUCTOR) | |
2682 | { | |
2b3ab879 | 2683 | if (!ctx->quiet) |
2d76680f PC |
2684 | error ("%qE is not a constant expression", orig_whole); |
2685 | *non_constant_p = true; | |
2686 | } | |
2687 | if (DECL_MUTABLE_P (part)) | |
2688 | { | |
2b3ab879 | 2689 | if (!ctx->quiet) |
2d76680f PC |
2690 | error ("mutable %qD is not usable in a constant expression", part); |
2691 | *non_constant_p = true; | |
2692 | } | |
2693 | if (*non_constant_p) | |
2694 | return t; | |
2db613e5 | 2695 | bool pmf = TYPE_PTRMEMFUNC_P (TREE_TYPE (whole)); |
2d76680f PC |
2696 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (whole), i, field, value) |
2697 | { | |
2db613e5 JM |
2698 | /* Use name match for PMF fields, as a variant will have a |
2699 | different FIELD_DECL with a different type. */ | |
2700 | if (pmf ? DECL_NAME (field) == DECL_NAME (part) | |
2701 | : field == part) | |
60813a46 JM |
2702 | { |
2703 | if (value) | |
2704 | return value; | |
2705 | else | |
2706 | /* We're in the middle of initializing it. */ | |
2707 | break; | |
2708 | } | |
2d76680f PC |
2709 | } |
2710 | if (TREE_CODE (TREE_TYPE (whole)) == UNION_TYPE | |
2711 | && CONSTRUCTOR_NELTS (whole) > 0) | |
2712 | { | |
2713 | /* DR 1188 says we don't have to deal with this. */ | |
2b3ab879 | 2714 | if (!ctx->quiet) |
2d76680f PC |
2715 | error ("accessing %qD member instead of initialized %qD member in " |
2716 | "constant expression", part, CONSTRUCTOR_ELT (whole, 0)->index); | |
2717 | *non_constant_p = true; | |
2718 | return t; | |
2719 | } | |
2720 | ||
188e53bd JM |
2721 | /* We only create a CONSTRUCTOR for a subobject when we modify it, so empty |
2722 | classes never get represented; throw together a value now. */ | |
dbcd32f8 | 2723 | if (is_really_empty_class (TREE_TYPE (t), /*ignore_vptr*/false)) |
188e53bd JM |
2724 | return build_constructor (TREE_TYPE (t), NULL); |
2725 | ||
2db613e5 JM |
2726 | gcc_assert (DECL_CONTEXT (part) == TYPE_MAIN_VARIANT (TREE_TYPE (whole))); |
2727 | ||
e8c48716 | 2728 | if (CONSTRUCTOR_NO_CLEARING (whole)) |
3e605b20 JM |
2729 | { |
2730 | /* 'whole' is part of the aggregate initializer we're currently | |
2731 | building; if there's no initializer for this member yet, that's an | |
188e53bd | 2732 | error. */ |
2b3ab879 | 2733 | if (!ctx->quiet) |
3e605b20 JM |
2734 | error ("accessing uninitialized member %qD", part); |
2735 | *non_constant_p = true; | |
2736 | return t; | |
2737 | } | |
2738 | ||
2d76680f PC |
2739 | /* If there's no explicit init for this field, it's value-initialized. */ |
2740 | value = build_value_init (TREE_TYPE (t), tf_warning_or_error); | |
3e605b20 | 2741 | return cxx_eval_constant_expression (ctx, value, |
92a596e8 | 2742 | lval, |
5a804683 | 2743 | non_constant_p, overflow_p); |
2d76680f PC |
2744 | } |
2745 | ||
2746 | /* Subroutine of cxx_eval_constant_expression. | |
2747 | Attempt to reduce a field access of a value of class type that is | |
2748 | expressed as a BIT_FIELD_REF. */ | |
2749 | ||
2750 | static tree | |
3e605b20 | 2751 | cxx_eval_bit_field_ref (const constexpr_ctx *ctx, tree t, |
92a596e8 | 2752 | bool lval, |
2d76680f PC |
2753 | bool *non_constant_p, bool *overflow_p) |
2754 | { | |
2755 | tree orig_whole = TREE_OPERAND (t, 0); | |
2756 | tree retval, fldval, utype, mask; | |
2757 | bool fld_seen = false; | |
2758 | HOST_WIDE_INT istart, isize; | |
3e605b20 | 2759 | tree whole = cxx_eval_constant_expression (ctx, orig_whole, |
92a596e8 | 2760 | lval, |
5a804683 | 2761 | non_constant_p, overflow_p); |
2d76680f PC |
2762 | tree start, field, value; |
2763 | unsigned HOST_WIDE_INT i; | |
2764 | ||
2765 | if (whole == orig_whole) | |
2766 | return t; | |
2767 | /* Don't VERIFY_CONSTANT here; we only want to check that we got a | |
2768 | CONSTRUCTOR. */ | |
2769 | if (!*non_constant_p | |
2770 | && TREE_CODE (whole) != VECTOR_CST | |
2771 | && TREE_CODE (whole) != CONSTRUCTOR) | |
2772 | { | |
2b3ab879 | 2773 | if (!ctx->quiet) |
2d76680f PC |
2774 | error ("%qE is not a constant expression", orig_whole); |
2775 | *non_constant_p = true; | |
2776 | } | |
2777 | if (*non_constant_p) | |
2778 | return t; | |
2779 | ||
2780 | if (TREE_CODE (whole) == VECTOR_CST) | |
2781 | return fold_ternary (BIT_FIELD_REF, TREE_TYPE (t), whole, | |
2782 | TREE_OPERAND (t, 1), TREE_OPERAND (t, 2)); | |
2783 | ||
2784 | start = TREE_OPERAND (t, 2); | |
2785 | istart = tree_to_shwi (start); | |
2786 | isize = tree_to_shwi (TREE_OPERAND (t, 1)); | |
2787 | utype = TREE_TYPE (t); | |
2788 | if (!TYPE_UNSIGNED (utype)) | |
2789 | utype = build_nonstandard_integer_type (TYPE_PRECISION (utype), 1); | |
2790 | retval = build_int_cst (utype, 0); | |
2791 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (whole), i, field, value) | |
2792 | { | |
2793 | tree bitpos = bit_position (field); | |
2794 | if (bitpos == start && DECL_SIZE (field) == TREE_OPERAND (t, 1)) | |
2795 | return value; | |
2796 | if (TREE_CODE (TREE_TYPE (field)) == INTEGER_TYPE | |
2797 | && TREE_CODE (value) == INTEGER_CST | |
2798 | && tree_fits_shwi_p (bitpos) | |
2799 | && tree_fits_shwi_p (DECL_SIZE (field))) | |
2800 | { | |
2801 | HOST_WIDE_INT bit = tree_to_shwi (bitpos); | |
2802 | HOST_WIDE_INT sz = tree_to_shwi (DECL_SIZE (field)); | |
2803 | HOST_WIDE_INT shift; | |
2804 | if (bit >= istart && bit + sz <= istart + isize) | |
2805 | { | |
2806 | fldval = fold_convert (utype, value); | |
2807 | mask = build_int_cst_type (utype, -1); | |
2808 | mask = fold_build2 (LSHIFT_EXPR, utype, mask, | |
2809 | size_int (TYPE_PRECISION (utype) - sz)); | |
2810 | mask = fold_build2 (RSHIFT_EXPR, utype, mask, | |
2811 | size_int (TYPE_PRECISION (utype) - sz)); | |
2812 | fldval = fold_build2 (BIT_AND_EXPR, utype, fldval, mask); | |
2813 | shift = bit - istart; | |
2814 | if (BYTES_BIG_ENDIAN) | |
2815 | shift = TYPE_PRECISION (utype) - shift - sz; | |
2816 | fldval = fold_build2 (LSHIFT_EXPR, utype, fldval, | |
2817 | size_int (shift)); | |
2818 | retval = fold_build2 (BIT_IOR_EXPR, utype, retval, fldval); | |
2819 | fld_seen = true; | |
2820 | } | |
2821 | } | |
2822 | } | |
2823 | if (fld_seen) | |
2824 | return fold_convert (TREE_TYPE (t), retval); | |
2825 | gcc_unreachable (); | |
2826 | return error_mark_node; | |
2827 | } | |
2828 | ||
2829 | /* Subroutine of cxx_eval_constant_expression. | |
2830 | Evaluate a short-circuited logical expression T in the context | |
2831 | of a given constexpr CALL. BAILOUT_VALUE is the value for | |
2832 | early return. CONTINUE_VALUE is used here purely for | |
2833 | sanity check purposes. */ | |
2834 | ||
2835 | static tree | |
3e605b20 | 2836 | cxx_eval_logical_expression (const constexpr_ctx *ctx, tree t, |
2d76680f | 2837 | tree bailout_value, tree continue_value, |
92a596e8 | 2838 | bool lval, |
2d76680f PC |
2839 | bool *non_constant_p, bool *overflow_p) |
2840 | { | |
2841 | tree r; | |
3e605b20 | 2842 | tree lhs = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), |
92a596e8 | 2843 | lval, |
5a804683 | 2844 | non_constant_p, overflow_p); |
2d76680f PC |
2845 | VERIFY_CONSTANT (lhs); |
2846 | if (tree_int_cst_equal (lhs, bailout_value)) | |
2847 | return lhs; | |
2848 | gcc_assert (tree_int_cst_equal (lhs, continue_value)); | |
3e605b20 | 2849 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), |
92a596e8 | 2850 | lval, non_constant_p, |
5a804683 | 2851 | overflow_p); |
2d76680f PC |
2852 | VERIFY_CONSTANT (r); |
2853 | return r; | |
2854 | } | |
2855 | ||
2856 | /* REF is a COMPONENT_REF designating a particular field. V is a vector of | |
2857 | CONSTRUCTOR elements to initialize (part of) an object containing that | |
2858 | field. Return a pointer to the constructor_elt corresponding to the | |
2859 | initialization of the field. */ | |
2860 | ||
2861 | static constructor_elt * | |
2862 | base_field_constructor_elt (vec<constructor_elt, va_gc> *v, tree ref) | |
2863 | { | |
2864 | tree aggr = TREE_OPERAND (ref, 0); | |
2865 | tree field = TREE_OPERAND (ref, 1); | |
2866 | HOST_WIDE_INT i; | |
2867 | constructor_elt *ce; | |
2868 | ||
2869 | gcc_assert (TREE_CODE (ref) == COMPONENT_REF); | |
2870 | ||
2871 | if (TREE_CODE (aggr) == COMPONENT_REF) | |
2872 | { | |
2873 | constructor_elt *base_ce | |
2874 | = base_field_constructor_elt (v, aggr); | |
2875 | v = CONSTRUCTOR_ELTS (base_ce->value); | |
2876 | } | |
2877 | ||
2878 | for (i = 0; vec_safe_iterate (v, i, &ce); ++i) | |
2879 | if (ce->index == field) | |
2880 | return ce; | |
2881 | ||
2882 | gcc_unreachable (); | |
2883 | return NULL; | |
2884 | } | |
2885 | ||
3e605b20 JM |
2886 | /* Some of the expressions fed to the constexpr mechanism are calls to |
2887 | constructors, which have type void. In that case, return the type being | |
2888 | initialized by the constructor. */ | |
2889 | ||
2890 | static tree | |
2891 | initialized_type (tree t) | |
2892 | { | |
2893 | if (TYPE_P (t)) | |
2894 | return t; | |
5dab8b11 | 2895 | tree type = TREE_TYPE (t); |
4d0c18c6 | 2896 | if (TREE_CODE (t) == CALL_EXPR) |
3e605b20 JM |
2897 | { |
2898 | /* A constructor call has void type, so we need to look deeper. */ | |
2899 | tree fn = get_function_named_in_call (t); | |
2900 | if (fn && TREE_CODE (fn) == FUNCTION_DECL | |
2901 | && DECL_CXX_CONSTRUCTOR_P (fn)) | |
2902 | type = DECL_CONTEXT (fn); | |
2903 | } | |
4d0c18c6 JM |
2904 | else if (TREE_CODE (t) == COMPOUND_EXPR) |
2905 | return initialized_type (TREE_OPERAND (t, 1)); | |
5dab8b11 JM |
2906 | else if (TREE_CODE (t) == AGGR_INIT_EXPR) |
2907 | type = TREE_TYPE (AGGR_INIT_EXPR_SLOT (t)); | |
2908 | return cv_unqualified (type); | |
3e605b20 JM |
2909 | } |
2910 | ||
2911 | /* We're about to initialize element INDEX of an array or class from VALUE. | |
2912 | Set up NEW_CTX appropriately by adjusting .object to refer to the | |
2913 | subobject and creating a new CONSTRUCTOR if the element is itself | |
2914 | a class or array. */ | |
2915 | ||
2916 | static void | |
2917 | init_subob_ctx (const constexpr_ctx *ctx, constexpr_ctx &new_ctx, | |
2918 | tree index, tree &value) | |
2919 | { | |
2920 | new_ctx = *ctx; | |
2921 | ||
2922 | if (index && TREE_CODE (index) != INTEGER_CST | |
2923 | && TREE_CODE (index) != FIELD_DECL) | |
2924 | /* This won't have an element in the new CONSTRUCTOR. */ | |
2925 | return; | |
2926 | ||
2927 | tree type = initialized_type (value); | |
2928 | if (!AGGREGATE_TYPE_P (type) && !VECTOR_TYPE_P (type)) | |
2929 | /* A non-aggregate member doesn't get its own CONSTRUCTOR. */ | |
2930 | return; | |
2931 | ||
2932 | /* The sub-aggregate initializer might contain a placeholder; | |
2933 | update object to refer to the subobject and ctor to refer to | |
2934 | the (newly created) sub-initializer. */ | |
2935 | if (ctx->object) | |
2936 | new_ctx.object = build_ctor_subob_ref (index, type, ctx->object); | |
2937 | tree elt = build_constructor (type, NULL); | |
e8c48716 | 2938 | CONSTRUCTOR_NO_CLEARING (elt) = true; |
3e605b20 JM |
2939 | new_ctx.ctor = elt; |
2940 | ||
2941 | if (TREE_CODE (value) == TARGET_EXPR) | |
2942 | /* Avoid creating another CONSTRUCTOR when we expand the TARGET_EXPR. */ | |
2943 | value = TARGET_EXPR_INITIAL (value); | |
2944 | } | |
2945 | ||
2946 | /* We're about to process an initializer for a class or array TYPE. Make | |
2947 | sure that CTX is set up appropriately. */ | |
2948 | ||
2949 | static void | |
2950 | verify_ctor_sanity (const constexpr_ctx *ctx, tree type) | |
2951 | { | |
2952 | /* We don't bother building a ctor for an empty base subobject. */ | |
2953 | if (is_empty_class (type)) | |
2954 | return; | |
2955 | ||
2956 | /* We're in the middle of an initializer that might involve placeholders; | |
2957 | our caller should have created a CONSTRUCTOR for us to put the | |
2958 | initializer into. We will either return that constructor or T. */ | |
2959 | gcc_assert (ctx->ctor); | |
2960 | gcc_assert (same_type_ignoring_top_level_qualifiers_p | |
2961 | (type, TREE_TYPE (ctx->ctor))); | |
fe69277d JM |
2962 | /* We used to check that ctx->ctor was empty, but that isn't the case when |
2963 | the object is zero-initialized before calling the constructor. */ | |
3e605b20 | 2964 | if (ctx->object) |
176e79b5 JM |
2965 | { |
2966 | tree otype = TREE_TYPE (ctx->object); | |
2967 | gcc_assert (same_type_ignoring_top_level_qualifiers_p (type, otype) | |
2968 | /* Handle flexible array members. */ | |
2969 | || (TREE_CODE (otype) == ARRAY_TYPE | |
2970 | && TYPE_DOMAIN (otype) == NULL_TREE | |
2971 | && TREE_CODE (type) == ARRAY_TYPE | |
2972 | && (same_type_ignoring_top_level_qualifiers_p | |
2973 | (TREE_TYPE (type), TREE_TYPE (otype))))); | |
2974 | } | |
3e605b20 JM |
2975 | gcc_assert (!ctx->object || !DECL_P (ctx->object) |
2976 | || *(ctx->values->get (ctx->object)) == ctx->ctor); | |
2977 | } | |
2978 | ||
2d76680f PC |
2979 | /* Subroutine of cxx_eval_constant_expression. |
2980 | The expression tree T denotes a C-style array or a C-style | |
2981 | aggregate. Reduce it to a constant expression. */ | |
2982 | ||
2983 | static tree | |
3e605b20 | 2984 | cxx_eval_bare_aggregate (const constexpr_ctx *ctx, tree t, |
92a596e8 | 2985 | bool lval, |
2d76680f PC |
2986 | bool *non_constant_p, bool *overflow_p) |
2987 | { | |
2988 | vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (t); | |
2d76680f PC |
2989 | bool changed = false; |
2990 | gcc_assert (!BRACE_ENCLOSED_INITIALIZER_P (t)); | |
8a29084d | 2991 | tree type = TREE_TYPE (t); |
3e605b20 | 2992 | |
8a29084d | 2993 | constexpr_ctx new_ctx; |
d4619dc1 | 2994 | if (TYPE_PTRMEMFUNC_P (type) || VECTOR_TYPE_P (type)) |
8a29084d | 2995 | { |
d4619dc1 NS |
2996 | /* We don't really need the ctx->ctor business for a PMF or |
2997 | vector, but it's simpler to use the same code. */ | |
8a29084d JM |
2998 | new_ctx = *ctx; |
2999 | new_ctx.ctor = build_constructor (type, NULL); | |
3000 | new_ctx.object = NULL_TREE; | |
3001 | ctx = &new_ctx; | |
3002 | }; | |
3003 | verify_ctor_sanity (ctx, type); | |
3e605b20 JM |
3004 | vec<constructor_elt, va_gc> **p = &CONSTRUCTOR_ELTS (ctx->ctor); |
3005 | vec_alloc (*p, vec_safe_length (v)); | |
3006 | ||
2d63bc39 JM |
3007 | unsigned i; |
3008 | tree index, value; | |
3009 | bool constant_p = true; | |
3010 | bool side_effects_p = false; | |
3e605b20 | 3011 | FOR_EACH_CONSTRUCTOR_ELT (v, i, index, value) |
2d76680f | 3012 | { |
bcb5f3c9 | 3013 | tree orig_value = value; |
3e605b20 JM |
3014 | init_subob_ctx (ctx, new_ctx, index, value); |
3015 | if (new_ctx.ctor != ctx->ctor) | |
3016 | /* If we built a new CONSTRUCTOR, attach it now so that other | |
3017 | initializers can refer to it. */ | |
3018 | CONSTRUCTOR_APPEND_ELT (*p, index, new_ctx.ctor); | |
3019 | tree elt = cxx_eval_constant_expression (&new_ctx, value, | |
92a596e8 | 3020 | lval, |
5a804683 | 3021 | non_constant_p, overflow_p); |
2d76680f | 3022 | /* Don't VERIFY_CONSTANT here. */ |
2b3ab879 | 3023 | if (ctx->quiet && *non_constant_p) |
3e605b20 | 3024 | break; |
bcb5f3c9 | 3025 | if (elt != orig_value) |
2d76680f | 3026 | changed = true; |
2d63bc39 JM |
3027 | |
3028 | if (!TREE_CONSTANT (elt)) | |
3029 | constant_p = false; | |
3030 | if (TREE_SIDE_EFFECTS (elt)) | |
3031 | side_effects_p = true; | |
3e605b20 | 3032 | if (index && TREE_CODE (index) == COMPONENT_REF) |
2d76680f PC |
3033 | { |
3034 | /* This is an initialization of a vfield inside a base | |
3035 | subaggregate that we already initialized; push this | |
3036 | initialization into the previous initialization. */ | |
3e605b20 | 3037 | constructor_elt *inner = base_field_constructor_elt (*p, index); |
2d76680f | 3038 | inner->value = elt; |
3e605b20 | 3039 | changed = true; |
2d76680f | 3040 | } |
3e605b20 JM |
3041 | else if (index |
3042 | && (TREE_CODE (index) == NOP_EXPR | |
3043 | || TREE_CODE (index) == POINTER_PLUS_EXPR)) | |
2d76680f PC |
3044 | { |
3045 | /* This is an initializer for an empty base; now that we've | |
3046 | checked that it's constant, we can ignore it. */ | |
3e605b20 JM |
3047 | gcc_assert (is_empty_class (TREE_TYPE (TREE_TYPE (index)))); |
3048 | changed = true; | |
3049 | } | |
2d76680f | 3050 | else |
ac9ec198 | 3051 | { |
1bdbef09 MP |
3052 | if (new_ctx.ctor != ctx->ctor) |
3053 | { | |
3054 | /* We appended this element above; update the value. */ | |
3055 | gcc_assert ((*p)->last().index == index); | |
3056 | (*p)->last().value = elt; | |
3057 | } | |
3058 | else | |
3059 | CONSTRUCTOR_APPEND_ELT (*p, index, elt); | |
3060 | /* Adding or replacing an element might change the ctor's flags. */ | |
ac9ec198 MP |
3061 | TREE_CONSTANT (ctx->ctor) = constant_p; |
3062 | TREE_SIDE_EFFECTS (ctx->ctor) = side_effects_p; | |
3063 | } | |
2d76680f PC |
3064 | } |
3065 | if (*non_constant_p || !changed) | |
3e605b20 JM |
3066 | return t; |
3067 | t = ctx->ctor; | |
3068 | /* We're done building this CONSTRUCTOR, so now we can interpret an | |
3069 | element without an explicit initializer as value-initialized. */ | |
e8c48716 | 3070 | CONSTRUCTOR_NO_CLEARING (t) = false; |
2d63bc39 JM |
3071 | TREE_CONSTANT (t) = constant_p; |
3072 | TREE_SIDE_EFFECTS (t) = side_effects_p; | |
8a29084d | 3073 | if (VECTOR_TYPE_P (type)) |
2d76680f PC |
3074 | t = fold (t); |
3075 | return t; | |
3076 | } | |
3077 | ||
3078 | /* Subroutine of cxx_eval_constant_expression. | |
3079 | The expression tree T is a VEC_INIT_EXPR which denotes the desired | |
3080 | initialization of a non-static data member of array type. Reduce it to a | |
3081 | CONSTRUCTOR. | |
3082 | ||
3083 | Note that apart from value-initialization (when VALUE_INIT is true), | |
3084 | this is only intended to support value-initialization and the | |
3085 | initializations done by defaulted constructors for classes with | |
3086 | non-static data members of array type. In this case, VEC_INIT_EXPR_INIT | |
3087 | will either be NULL_TREE for the default constructor, or a COMPONENT_REF | |
3088 | for the copy/move constructor. */ | |
3089 | ||
3090 | static tree | |
3e605b20 | 3091 | cxx_eval_vec_init_1 (const constexpr_ctx *ctx, tree atype, tree init, |
92a596e8 | 3092 | bool value_init, bool lval, |
2d76680f PC |
3093 | bool *non_constant_p, bool *overflow_p) |
3094 | { | |
3095 | tree elttype = TREE_TYPE (atype); | |
3e605b20 JM |
3096 | verify_ctor_sanity (ctx, atype); |
3097 | vec<constructor_elt, va_gc> **p = &CONSTRUCTOR_ELTS (ctx->ctor); | |
2d76680f | 3098 | bool pre_init = false; |
4784470a | 3099 | unsigned HOST_WIDE_INT i; |
dc5ca6c8 | 3100 | tsubst_flags_t complain = ctx->quiet ? tf_none : tf_warning_or_error; |
2d76680f PC |
3101 | |
3102 | /* For the default constructor, build up a call to the default | |
3103 | constructor of the element type. We only need to handle class types | |
3104 | here, as for a constructor to be constexpr, all members must be | |
3105 | initialized, which for a defaulted default constructor means they must | |
3106 | be of a class type with a constexpr default constructor. */ | |
3107 | if (TREE_CODE (elttype) == ARRAY_TYPE) | |
3108 | /* We only do this at the lowest level. */; | |
3109 | else if (value_init) | |
3110 | { | |
dc5ca6c8 | 3111 | init = build_value_init (elttype, complain); |
2d76680f PC |
3112 | pre_init = true; |
3113 | } | |
3114 | else if (!init) | |
3115 | { | |
3116 | vec<tree, va_gc> *argvec = make_tree_vector (); | |
3117 | init = build_special_member_call (NULL_TREE, complete_ctor_identifier, | |
3118 | &argvec, elttype, LOOKUP_NORMAL, | |
dc5ca6c8 | 3119 | complain); |
2d76680f | 3120 | release_tree_vector (argvec); |
5dab8b11 | 3121 | init = build_aggr_init_expr (elttype, init); |
2d76680f PC |
3122 | pre_init = true; |
3123 | } | |
3124 | ||
74f8705e MP |
3125 | tree nelts = get_array_or_vector_nelts (ctx, atype, non_constant_p, |
3126 | overflow_p); | |
3127 | unsigned HOST_WIDE_INT max = tree_to_uhwi (nelts); | |
4784470a | 3128 | for (i = 0; i < max; ++i) |
2d76680f PC |
3129 | { |
3130 | tree idx = build_int_cst (size_type_node, i); | |
3131 | tree eltinit; | |
928af3bf | 3132 | bool reuse = false; |
3e605b20 JM |
3133 | constexpr_ctx new_ctx; |
3134 | init_subob_ctx (ctx, new_ctx, idx, pre_init ? init : elttype); | |
3135 | if (new_ctx.ctor != ctx->ctor) | |
3136 | CONSTRUCTOR_APPEND_ELT (*p, idx, new_ctx.ctor); | |
2d76680f PC |
3137 | if (TREE_CODE (elttype) == ARRAY_TYPE) |
3138 | { | |
3139 | /* A multidimensional array; recurse. */ | |
3140 | if (value_init || init == NULL_TREE) | |
928af3bf JJ |
3141 | { |
3142 | eltinit = NULL_TREE; | |
3143 | reuse = i == 0; | |
3144 | } | |
2d76680f | 3145 | else |
dc5ca6c8 | 3146 | eltinit = cp_build_array_ref (input_location, init, idx, complain); |
3e605b20 | 3147 | eltinit = cxx_eval_vec_init_1 (&new_ctx, elttype, eltinit, value_init, |
92a596e8 | 3148 | lval, |
2d76680f PC |
3149 | non_constant_p, overflow_p); |
3150 | } | |
3151 | else if (pre_init) | |
3152 | { | |
3153 | /* Initializing an element using value or default initialization | |
3154 | we just pre-built above. */ | |
3ee378fb JM |
3155 | if (init == void_node) |
3156 | /* Trivial default-init, don't do anything to the CONSTRUCTOR. */ | |
3157 | return ctx->ctor; | |
928af3bf JJ |
3158 | eltinit = cxx_eval_constant_expression (&new_ctx, init, lval, |
3159 | non_constant_p, overflow_p); | |
3160 | reuse = i == 0; | |
2d76680f PC |
3161 | } |
3162 | else | |
3163 | { | |
3164 | /* Copying an element. */ | |
3165 | gcc_assert (same_type_ignoring_top_level_qualifiers_p | |
3166 | (atype, TREE_TYPE (init))); | |
dc5ca6c8 | 3167 | eltinit = cp_build_array_ref (input_location, init, idx, complain); |
72b3e203 | 3168 | if (!lvalue_p (init)) |
2d76680f | 3169 | eltinit = move (eltinit); |
dc5ca6c8 | 3170 | eltinit = force_rvalue (eltinit, complain); |
c2236b9b JJ |
3171 | eltinit = cxx_eval_constant_expression (&new_ctx, eltinit, lval, |
3172 | non_constant_p, overflow_p); | |
2d76680f | 3173 | } |
2b3ab879 | 3174 | if (*non_constant_p && !ctx->quiet) |
3e605b20 JM |
3175 | break; |
3176 | if (new_ctx.ctor != ctx->ctor) | |
3177 | { | |
3178 | /* We appended this element above; update the value. */ | |
3179 | gcc_assert ((*p)->last().index == idx); | |
3180 | (*p)->last().value = eltinit; | |
3181 | } | |
3182 | else | |
3183 | CONSTRUCTOR_APPEND_ELT (*p, idx, eltinit); | |
928af3bf | 3184 | /* Reuse the result of cxx_eval_constant_expression call |
c2236b9b JJ |
3185 | from the first iteration to all others if it is a constant |
3186 | initializer that doesn't require relocations. */ | |
928af3bf JJ |
3187 | if (reuse |
3188 | && max > 1 | |
c2236b9b JJ |
3189 | && (eltinit == NULL_TREE |
3190 | || (initializer_constant_valid_p (eltinit, TREE_TYPE (eltinit)) | |
3191 | == null_pointer_node))) | |
928af3bf JJ |
3192 | { |
3193 | if (new_ctx.ctor != ctx->ctor) | |
3194 | eltinit = new_ctx.ctor; | |
1e027956 RB |
3195 | tree range = build2 (RANGE_EXPR, size_type_node, |
3196 | build_int_cst (size_type_node, 1), | |
3197 | build_int_cst (size_type_node, max - 1)); | |
3198 | CONSTRUCTOR_APPEND_ELT (*p, range, unshare_constructor (eltinit)); | |
928af3bf JJ |
3199 | break; |
3200 | } | |
1e027956 RB |
3201 | else if (i == 0) |
3202 | vec_safe_reserve (*p, max); | |
2d76680f PC |
3203 | } |
3204 | ||
3205 | if (!*non_constant_p) | |
3206 | { | |
3e605b20 | 3207 | init = ctx->ctor; |
e8c48716 | 3208 | CONSTRUCTOR_NO_CLEARING (init) = false; |
2d76680f | 3209 | } |
2d76680f PC |
3210 | return init; |
3211 | } | |
3212 | ||
3213 | static tree | |
3e605b20 | 3214 | cxx_eval_vec_init (const constexpr_ctx *ctx, tree t, |
92a596e8 | 3215 | bool lval, |
2d76680f PC |
3216 | bool *non_constant_p, bool *overflow_p) |
3217 | { | |
3218 | tree atype = TREE_TYPE (t); | |
3219 | tree init = VEC_INIT_EXPR_INIT (t); | |
3e605b20 | 3220 | tree r = cxx_eval_vec_init_1 (ctx, atype, init, |
2d76680f | 3221 | VEC_INIT_EXPR_VALUE_INIT (t), |
92a596e8 | 3222 | lval, non_constant_p, overflow_p); |
2d76680f PC |
3223 | if (*non_constant_p) |
3224 | return t; | |
3225 | else | |
3226 | return r; | |
3227 | } | |
3228 | ||
e4511ca2 JM |
3229 | /* Like same_type_ignoring_top_level_qualifiers_p, but also handle the case |
3230 | where the desired type is an array of unknown bounds because the variable | |
3231 | has had its bounds deduced since the wrapping expression was created. */ | |
3232 | ||
3233 | static bool | |
3234 | same_type_ignoring_tlq_and_bounds_p (tree type1, tree type2) | |
3235 | { | |
3236 | while (TREE_CODE (type1) == ARRAY_TYPE | |
3237 | && TREE_CODE (type2) == ARRAY_TYPE | |
3238 | && (!TYPE_DOMAIN (type1) || !TYPE_DOMAIN (type2))) | |
3239 | { | |
3240 | type1 = TREE_TYPE (type1); | |
3241 | type2 = TREE_TYPE (type2); | |
3242 | } | |
3243 | return same_type_ignoring_top_level_qualifiers_p (type1, type2); | |
3244 | } | |
3245 | ||
2d76680f PC |
3246 | /* A less strict version of fold_indirect_ref_1, which requires cv-quals to |
3247 | match. We want to be less strict for simple *& folding; if we have a | |
3248 | non-const temporary that we access through a const pointer, that should | |
3249 | work. We handle this here rather than change fold_indirect_ref_1 | |
3250 | because we're dealing with things like ADDR_EXPR of INTEGER_CST which | |
3251 | don't really make sense outside of constant expression evaluation. Also | |
3252 | we want to allow folding to COMPONENT_REF, which could cause trouble | |
3253 | with TBAA in fold_indirect_ref_1. | |
3254 | ||
3255 | Try to keep this function synced with fold_indirect_ref_1. */ | |
3256 | ||
3257 | static tree | |
3258 | cxx_fold_indirect_ref (location_t loc, tree type, tree op0, bool *empty_base) | |
3259 | { | |
ebe4bf41 MP |
3260 | tree sub = op0; |
3261 | tree subtype; | |
3262 | poly_uint64 const_op01; | |
2d76680f | 3263 | |
2d76680f PC |
3264 | STRIP_NOPS (sub); |
3265 | subtype = TREE_TYPE (sub); | |
71a93b08 | 3266 | if (!INDIRECT_TYPE_P (subtype)) |
2d76680f PC |
3267 | return NULL_TREE; |
3268 | ||
3269 | if (TREE_CODE (sub) == ADDR_EXPR) | |
3270 | { | |
3271 | tree op = TREE_OPERAND (sub, 0); | |
3272 | tree optype = TREE_TYPE (op); | |
3273 | ||
3274 | /* *&CONST_DECL -> to the value of the const decl. */ | |
3275 | if (TREE_CODE (op) == CONST_DECL) | |
3276 | return DECL_INITIAL (op); | |
3277 | /* *&p => p; make sure to handle *&"str"[cst] here. */ | |
e4511ca2 | 3278 | if (same_type_ignoring_tlq_and_bounds_p (optype, type)) |
2d76680f PC |
3279 | { |
3280 | tree fop = fold_read_from_constant_string (op); | |
3281 | if (fop) | |
3282 | return fop; | |
3283 | else | |
3284 | return op; | |
3285 | } | |
3286 | /* *(foo *)&fooarray => fooarray[0] */ | |
3287 | else if (TREE_CODE (optype) == ARRAY_TYPE | |
3288 | && (same_type_ignoring_top_level_qualifiers_p | |
3289 | (type, TREE_TYPE (optype)))) | |
3290 | { | |
3291 | tree type_domain = TYPE_DOMAIN (optype); | |
3292 | tree min_val = size_zero_node; | |
3293 | if (type_domain && TYPE_MIN_VALUE (type_domain)) | |
3294 | min_val = TYPE_MIN_VALUE (type_domain); | |
3295 | return build4_loc (loc, ARRAY_REF, type, op, min_val, | |
3296 | NULL_TREE, NULL_TREE); | |
3297 | } | |
3298 | /* *(foo *)&complexfoo => __real__ complexfoo */ | |
3299 | else if (TREE_CODE (optype) == COMPLEX_TYPE | |
3300 | && (same_type_ignoring_top_level_qualifiers_p | |
3301 | (type, TREE_TYPE (optype)))) | |
3302 | return fold_build1_loc (loc, REALPART_EXPR, type, op); | |
3303 | /* *(foo *)&vectorfoo => BIT_FIELD_REF<vectorfoo,...> */ | |
b55b02ea | 3304 | else if (VECTOR_TYPE_P (optype) |
2d76680f PC |
3305 | && (same_type_ignoring_top_level_qualifiers_p |
3306 | (type, TREE_TYPE (optype)))) | |
3307 | { | |
3308 | tree part_width = TYPE_SIZE (type); | |
3309 | tree index = bitsize_int (0); | |
ebe4bf41 MP |
3310 | return fold_build3_loc (loc, BIT_FIELD_REF, type, op, part_width, |
3311 | index); | |
2d76680f PC |
3312 | } |
3313 | /* Also handle conversion to an empty base class, which | |
3314 | is represented with a NOP_EXPR. */ | |
3315 | else if (is_empty_class (type) | |
3316 | && CLASS_TYPE_P (optype) | |
3317 | && DERIVED_FROM_P (type, optype)) | |
3318 | { | |
3319 | *empty_base = true; | |
3320 | return op; | |
3321 | } | |
3322 | /* *(foo *)&struct_with_foo_field => COMPONENT_REF */ | |
3323 | else if (RECORD_OR_UNION_TYPE_P (optype)) | |
3324 | { | |
3325 | tree field = TYPE_FIELDS (optype); | |
3326 | for (; field; field = DECL_CHAIN (field)) | |
3327 | if (TREE_CODE (field) == FIELD_DECL | |
b912f962 | 3328 | && TREE_TYPE (field) != error_mark_node |
2d76680f PC |
3329 | && integer_zerop (byte_position (field)) |
3330 | && (same_type_ignoring_top_level_qualifiers_p | |
3331 | (TREE_TYPE (field), type))) | |
b912f962 | 3332 | return fold_build3 (COMPONENT_REF, type, op, field, NULL_TREE); |
2d76680f PC |
3333 | } |
3334 | } | |
3335 | else if (TREE_CODE (sub) == POINTER_PLUS_EXPR | |
ebe4bf41 | 3336 | && poly_int_tree_p (TREE_OPERAND (sub, 1), &const_op01)) |
2d76680f PC |
3337 | { |
3338 | tree op00 = TREE_OPERAND (sub, 0); | |
3339 | tree op01 = TREE_OPERAND (sub, 1); | |
3340 | ||
3341 | STRIP_NOPS (op00); | |
3342 | if (TREE_CODE (op00) == ADDR_EXPR) | |
3343 | { | |
3344 | tree op00type; | |
3345 | op00 = TREE_OPERAND (op00, 0); | |
3346 | op00type = TREE_TYPE (op00); | |
3347 | ||
3348 | /* ((foo*)&vectorfoo)[1] => BIT_FIELD_REF<vectorfoo,...> */ | |
b55b02ea | 3349 | if (VECTOR_TYPE_P (op00type) |
ebe4bf41 MP |
3350 | && same_type_ignoring_top_level_qualifiers_p |
3351 | (type, TREE_TYPE (op00type)) | |
3352 | /* POINTER_PLUS_EXPR second operand is sizetype, unsigned, | |
3353 | but we want to treat offsets with MSB set as negative. | |
3354 | For the code below negative offsets are invalid and | |
3355 | TYPE_SIZE of the element is something unsigned, so | |
3356 | check whether op01 fits into poly_int64, which implies | |
3357 | it is from 0 to INTTYPE_MAXIMUM (HOST_WIDE_INT), and | |
3358 | then just use poly_uint64 because we want to treat the | |
3359 | value as unsigned. */ | |
3360 | && tree_fits_poly_int64_p (op01)) | |
2d76680f | 3361 | { |
2d76680f | 3362 | tree part_width = TYPE_SIZE (type); |
ebe4bf41 MP |
3363 | poly_uint64 max_offset |
3364 | = (tree_to_uhwi (part_width) / BITS_PER_UNIT | |
3365 | * TYPE_VECTOR_SUBPARTS (op00type)); | |
3366 | if (known_lt (const_op01, max_offset)) | |
3367 | { | |
3368 | tree index = bitsize_int (const_op01 * BITS_PER_UNIT); | |
3369 | return fold_build3_loc (loc, | |
3370 | BIT_FIELD_REF, type, op00, | |
3371 | part_width, index); | |
3372 | } | |
2d76680f PC |
3373 | } |
3374 | /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */ | |
3375 | else if (TREE_CODE (op00type) == COMPLEX_TYPE | |
3376 | && (same_type_ignoring_top_level_qualifiers_p | |
3377 | (type, TREE_TYPE (op00type)))) | |
3378 | { | |
ebe4bf41 MP |
3379 | if (known_eq (wi::to_poly_offset (TYPE_SIZE_UNIT (type)), |
3380 | const_op01)) | |
2d76680f PC |
3381 | return fold_build1_loc (loc, IMAGPART_EXPR, type, op00); |
3382 | } | |
3383 | /* ((foo *)&fooarray)[1] => fooarray[1] */ | |
3384 | else if (TREE_CODE (op00type) == ARRAY_TYPE | |
3385 | && (same_type_ignoring_top_level_qualifiers_p | |
3386 | (type, TREE_TYPE (op00type)))) | |
3387 | { | |
3388 | tree type_domain = TYPE_DOMAIN (op00type); | |
3389 | tree min_val = size_zero_node; | |
3390 | if (type_domain && TYPE_MIN_VALUE (type_domain)) | |
3391 | min_val = TYPE_MIN_VALUE (type_domain); | |
b07c3651 MP |
3392 | offset_int off = wi::to_offset (op01); |
3393 | offset_int el_sz = wi::to_offset (TYPE_SIZE_UNIT (type)); | |
3394 | offset_int remainder; | |
3395 | off = wi::divmod_trunc (off, el_sz, SIGNED, &remainder); | |
3396 | if (remainder == 0 && TREE_CODE (min_val) == INTEGER_CST) | |
3397 | { | |
3398 | off = off + wi::to_offset (min_val); | |
3399 | op01 = wide_int_to_tree (sizetype, off); | |
3400 | return build4_loc (loc, ARRAY_REF, type, op00, op01, | |
3401 | NULL_TREE, NULL_TREE); | |
3402 | } | |
2d76680f PC |
3403 | } |
3404 | /* Also handle conversion to an empty base class, which | |
3405 | is represented with a NOP_EXPR. */ | |
3406 | else if (is_empty_class (type) | |
3407 | && CLASS_TYPE_P (op00type) | |
3408 | && DERIVED_FROM_P (type, op00type)) | |
3409 | { | |
3410 | *empty_base = true; | |
3411 | return op00; | |
3412 | } | |
3413 | /* ((foo *)&struct_with_foo_field)[1] => COMPONENT_REF */ | |
3414 | else if (RECORD_OR_UNION_TYPE_P (op00type)) | |
3415 | { | |
3416 | tree field = TYPE_FIELDS (op00type); | |
3417 | for (; field; field = DECL_CHAIN (field)) | |
3418 | if (TREE_CODE (field) == FIELD_DECL | |
b912f962 | 3419 | && TREE_TYPE (field) != error_mark_node |
2d76680f PC |
3420 | && tree_int_cst_equal (byte_position (field), op01) |
3421 | && (same_type_ignoring_top_level_qualifiers_p | |
3422 | (TREE_TYPE (field), type))) | |
b912f962 JJ |
3423 | return fold_build3 (COMPONENT_REF, type, op00, |
3424 | field, NULL_TREE); | |
2d76680f PC |
3425 | } |
3426 | } | |
3427 | } | |
3428 | /* *(foo *)fooarrptr => (*fooarrptr)[0] */ | |
3429 | else if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE | |
3430 | && (same_type_ignoring_top_level_qualifiers_p | |
3431 | (type, TREE_TYPE (TREE_TYPE (subtype))))) | |
3432 | { | |
3433 | tree type_domain; | |
3434 | tree min_val = size_zero_node; | |
ebe4bf41 MP |
3435 | tree newsub |
3436 | = cxx_fold_indirect_ref (loc, TREE_TYPE (subtype), sub, NULL); | |
2d76680f PC |
3437 | if (newsub) |
3438 | sub = newsub; | |
3439 | else | |
3440 | sub = build1_loc (loc, INDIRECT_REF, TREE_TYPE (subtype), sub); | |
3441 | type_domain = TYPE_DOMAIN (TREE_TYPE (sub)); | |
3442 | if (type_domain && TYPE_MIN_VALUE (type_domain)) | |
3443 | min_val = TYPE_MIN_VALUE (type_domain); | |
3444 | return build4_loc (loc, ARRAY_REF, type, sub, min_val, NULL_TREE, | |
3445 | NULL_TREE); | |
3446 | } | |
3447 | ||
3448 | return NULL_TREE; | |
3449 | } | |
3450 | ||
3451 | static tree | |
3e605b20 | 3452 | cxx_eval_indirect_ref (const constexpr_ctx *ctx, tree t, |
92a596e8 | 3453 | bool lval, |
2d76680f PC |
3454 | bool *non_constant_p, bool *overflow_p) |
3455 | { | |
3456 | tree orig_op0 = TREE_OPERAND (t, 0); | |
2d76680f | 3457 | bool empty_base = false; |
2d76680f | 3458 | |
cda0a029 JM |
3459 | /* We can handle a MEM_REF like an INDIRECT_REF, if MEM_REF's second |
3460 | operand is an integer-zero. Otherwise reject the MEM_REF for now. */ | |
3461 | ||
3462 | if (TREE_CODE (t) == MEM_REF | |
3463 | && (!TREE_OPERAND (t, 1) || !integer_zerop (TREE_OPERAND (t, 1)))) | |
3464 | { | |
3465 | gcc_assert (ctx->quiet); | |
3466 | *non_constant_p = true; | |
3467 | return t; | |
3468 | } | |
3469 | ||
255a48d6 JM |
3470 | /* First try to simplify it directly. */ |
3471 | tree r = cxx_fold_indirect_ref (EXPR_LOCATION (t), TREE_TYPE (t), orig_op0, | |
3472 | &empty_base); | |
3473 | if (!r) | |
2d76680f | 3474 | { |
255a48d6 JM |
3475 | /* If that didn't work, evaluate the operand first. */ |
3476 | tree op0 = cxx_eval_constant_expression (ctx, orig_op0, | |
3477 | /*lval*/false, non_constant_p, | |
3478 | overflow_p); | |
3479 | /* Don't VERIFY_CONSTANT here. */ | |
3480 | if (*non_constant_p) | |
3481 | return t; | |
3482 | ||
8bada5cd MS |
3483 | if (!lval && integer_zerop (op0)) |
3484 | { | |
3485 | if (!ctx->quiet) | |
3486 | error ("dereferencing a null pointer"); | |
3487 | *non_constant_p = true; | |
3488 | return t; | |
3489 | } | |
3490 | ||
255a48d6 JM |
3491 | r = cxx_fold_indirect_ref (EXPR_LOCATION (t), TREE_TYPE (t), op0, |
3492 | &empty_base); | |
3493 | if (r == NULL_TREE) | |
2d76680f PC |
3494 | { |
3495 | /* We couldn't fold to a constant value. Make sure it's not | |
3496 | something we should have been able to fold. */ | |
255a48d6 JM |
3497 | tree sub = op0; |
3498 | STRIP_NOPS (sub); | |
3499 | if (TREE_CODE (sub) == ADDR_EXPR) | |
3500 | { | |
3501 | gcc_assert (!same_type_ignoring_top_level_qualifiers_p | |
3502 | (TREE_TYPE (TREE_TYPE (sub)), TREE_TYPE (t))); | |
3503 | /* DR 1188 says we don't have to deal with this. */ | |
3504 | if (!ctx->quiet) | |
3505 | error ("accessing value of %qE through a %qT glvalue in a " | |
3506 | "constant expression", build_fold_indirect_ref (sub), | |
3507 | TREE_TYPE (t)); | |
3508 | *non_constant_p = true; | |
3509 | return t; | |
3510 | } | |
3511 | ||
3512 | if (lval && op0 != orig_op0) | |
3513 | return build1 (INDIRECT_REF, TREE_TYPE (t), op0); | |
3514 | if (!lval) | |
3515 | VERIFY_CONSTANT (t); | |
2d76680f PC |
3516 | return t; |
3517 | } | |
3518 | } | |
3519 | ||
255a48d6 JM |
3520 | r = cxx_eval_constant_expression (ctx, r, |
3521 | lval, non_constant_p, overflow_p); | |
3522 | if (*non_constant_p) | |
3523 | return t; | |
3524 | ||
125db6a1 | 3525 | /* If we're pulling out the value of an empty base, just return an empty |
2d76680f | 3526 | CONSTRUCTOR. */ |
92a596e8 | 3527 | if (empty_base && !lval) |
2d76680f | 3528 | { |
2d76680f PC |
3529 | r = build_constructor (TREE_TYPE (t), NULL); |
3530 | TREE_CONSTANT (r) = true; | |
3531 | } | |
3532 | ||
2d76680f PC |
3533 | return r; |
3534 | } | |
3535 | ||
3536 | /* Complain about R, a VAR_DECL, not being usable in a constant expression. | |
3537 | Shared between potential_constant_expression and | |
3538 | cxx_eval_constant_expression. */ | |
3539 | ||
3540 | static void | |
3541 | non_const_var_error (tree r) | |
3542 | { | |
3543 | tree type = TREE_TYPE (r); | |
3544 | error ("the value of %qD is not usable in a constant " | |
3545 | "expression", r); | |
3546 | /* Avoid error cascade. */ | |
3547 | if (DECL_INITIAL (r) == error_mark_node) | |
3548 | return; | |
3549 | if (DECL_DECLARED_CONSTEXPR_P (r)) | |
3550 | inform (DECL_SOURCE_LOCATION (r), | |
3551 | "%qD used in its own initializer", r); | |
3552 | else if (INTEGRAL_OR_ENUMERATION_TYPE_P (type)) | |
3553 | { | |
3554 | if (!CP_TYPE_CONST_P (type)) | |
3555 | inform (DECL_SOURCE_LOCATION (r), | |
3556 | "%q#D is not const", r); | |
3557 | else if (CP_TYPE_VOLATILE_P (type)) | |
3558 | inform (DECL_SOURCE_LOCATION (r), | |
3559 | "%q#D is volatile", r); | |
3560 | else if (!DECL_INITIAL (r) | |
a3e2b438 PP |
3561 | || !TREE_CONSTANT (DECL_INITIAL (r)) |
3562 | || !DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r)) | |
2d76680f PC |
3563 | inform (DECL_SOURCE_LOCATION (r), |
3564 | "%qD was not initialized with a constant " | |
3565 | "expression", r); | |
3566 | else | |
3567 | gcc_unreachable (); | |
3568 | } | |
9f613f06 | 3569 | else if (TYPE_REF_P (type)) |
fd338b13 JM |
3570 | inform (DECL_SOURCE_LOCATION (r), |
3571 | "%qD was not initialized with a constant " | |
3572 | "expression", r); | |
2d76680f PC |
3573 | else |
3574 | { | |
3575 | if (cxx_dialect >= cxx11 && !DECL_DECLARED_CONSTEXPR_P (r)) | |
3576 | inform (DECL_SOURCE_LOCATION (r), | |
3577 | "%qD was not declared %<constexpr%>", r); | |
3578 | else | |
3579 | inform (DECL_SOURCE_LOCATION (r), | |
3580 | "%qD does not have integral or enumeration type", | |
3581 | r); | |
3582 | } | |
3583 | } | |
3584 | ||
3585 | /* Subroutine of cxx_eval_constant_expression. | |
3586 | Like cxx_eval_unary_expression, except for trinary expressions. */ | |
3587 | ||
3588 | static tree | |
3e605b20 | 3589 | cxx_eval_trinary_expression (const constexpr_ctx *ctx, tree t, |
92a596e8 | 3590 | bool lval, |
2d76680f PC |
3591 | bool *non_constant_p, bool *overflow_p) |
3592 | { | |
3593 | int i; | |
3594 | tree args[3]; | |
3595 | tree val; | |
3596 | ||
3597 | for (i = 0; i < 3; i++) | |
3598 | { | |
3e605b20 | 3599 | args[i] = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, i), |
92a596e8 | 3600 | lval, |
5a804683 | 3601 | non_constant_p, overflow_p); |
2d76680f PC |
3602 | VERIFY_CONSTANT (args[i]); |
3603 | } | |
3604 | ||
3605 | val = fold_ternary_loc (EXPR_LOCATION (t), TREE_CODE (t), TREE_TYPE (t), | |
3606 | args[0], args[1], args[2]); | |
3607 | if (val == NULL_TREE) | |
3608 | return t; | |
3609 | VERIFY_CONSTANT (val); | |
3610 | return val; | |
3611 | } | |
3612 | ||
98e5a19a JM |
3613 | /* True if T was declared in a function declared to be constexpr, and |
3614 | therefore potentially constant in C++14. */ | |
3615 | ||
2d76680f PC |
3616 | bool |
3617 | var_in_constexpr_fn (tree t) | |
3618 | { | |
3619 | tree ctx = DECL_CONTEXT (t); | |
98e5a19a | 3620 | return (ctx && TREE_CODE (ctx) == FUNCTION_DECL |
2d76680f PC |
3621 | && DECL_DECLARED_CONSTEXPR_P (ctx)); |
3622 | } | |
3623 | ||
98e5a19a JM |
3624 | /* True if T was declared in a function that might be constexpr: either a |
3625 | function that was declared constexpr, or a C++17 lambda op(). */ | |
3626 | ||
3627 | bool | |
3628 | var_in_maybe_constexpr_fn (tree t) | |
3629 | { | |
7b936140 | 3630 | if (cxx_dialect >= cxx17 |
98e5a19a JM |
3631 | && DECL_FUNCTION_SCOPE_P (t) |
3632 | && LAMBDA_FUNCTION_P (DECL_CONTEXT (t))) | |
3633 | return true; | |
3634 | return var_in_constexpr_fn (t); | |
3635 | } | |
3636 | ||
68d01920 JM |
3637 | /* We're assigning INIT to TARGET. In do_build_copy_constructor and |
3638 | build_over_call we implement trivial copy of a class with tail padding using | |
3639 | assignment of character arrays, which is valid in normal code, but not in | |
3640 | constexpr evaluation. We don't need to worry about clobbering tail padding | |
3641 | in constexpr evaluation, so strip the type punning. */ | |
3642 | ||
3643 | static void | |
3644 | maybe_simplify_trivial_copy (tree &target, tree &init) | |
3645 | { | |
3646 | if (TREE_CODE (target) == MEM_REF | |
3647 | && TREE_CODE (init) == MEM_REF | |
3648 | && TREE_TYPE (target) == TREE_TYPE (init) | |
3649 | && TREE_CODE (TREE_TYPE (target)) == ARRAY_TYPE | |
3650 | && TREE_TYPE (TREE_TYPE (target)) == unsigned_char_type_node) | |
3651 | { | |
3652 | target = build_fold_indirect_ref (TREE_OPERAND (target, 0)); | |
3653 | init = build_fold_indirect_ref (TREE_OPERAND (init, 0)); | |
3654 | } | |
3655 | } | |
3656 | ||
60813a46 JM |
3657 | /* Evaluate an INIT_EXPR or MODIFY_EXPR. */ |
3658 | ||
3659 | static tree | |
3660 | cxx_eval_store_expression (const constexpr_ctx *ctx, tree t, | |
92a596e8 | 3661 | bool lval, |
60813a46 JM |
3662 | bool *non_constant_p, bool *overflow_p) |
3663 | { | |
3664 | constexpr_ctx new_ctx = *ctx; | |
3665 | ||
58cc255c JM |
3666 | tree init = TREE_OPERAND (t, 1); |
3667 | if (TREE_CLOBBER_P (init)) | |
3668 | /* Just ignore clobbers. */ | |
3669 | return void_node; | |
3670 | ||
60813a46 JM |
3671 | /* First we figure out where we're storing to. */ |
3672 | tree target = TREE_OPERAND (t, 0); | |
68d01920 JM |
3673 | |
3674 | maybe_simplify_trivial_copy (target, init); | |
3675 | ||
3f8e2835 | 3676 | tree type = TREE_TYPE (target); |
e8b3c1bc JM |
3677 | bool preeval = SCALAR_TYPE_P (type) || TREE_CODE (t) == MODIFY_EXPR; |
3678 | if (preeval) | |
3679 | { | |
3680 | /* Evaluate the value to be stored without knowing what object it will be | |
3681 | stored in, so that any side-effects happen first. */ | |
3682 | if (!SCALAR_TYPE_P (type)) | |
3683 | new_ctx.ctor = new_ctx.object = NULL_TREE; | |
3684 | init = cxx_eval_constant_expression (&new_ctx, init, false, | |
3685 | non_constant_p, overflow_p); | |
3686 | if (*non_constant_p) | |
3687 | return t; | |
3688 | } | |
60813a46 | 3689 | target = cxx_eval_constant_expression (ctx, target, |
2b3ab879 | 3690 | true, |
5a804683 | 3691 | non_constant_p, overflow_p); |
60813a46 JM |
3692 | if (*non_constant_p) |
3693 | return t; | |
3694 | ||
bc2a38df JJ |
3695 | /* cxx_eval_array_reference for lval = true allows references one past |
3696 | end of array, because it does not know if it is just taking address | |
3697 | (which is valid), or actual dereference. Here we know it is | |
3698 | a dereference, so diagnose it here. */ | |
3699 | for (tree probe = target; probe; ) | |
3700 | { | |
3701 | switch (TREE_CODE (probe)) | |
3702 | { | |
3703 | case ARRAY_REF: | |
3704 | tree nelts, ary; | |
3705 | ary = TREE_OPERAND (probe, 0); | |
74f8705e MP |
3706 | nelts = get_array_or_vector_nelts (ctx, TREE_TYPE (ary), |
3707 | non_constant_p, overflow_p); | |
bc2a38df JJ |
3708 | VERIFY_CONSTANT (nelts); |
3709 | gcc_assert (TREE_CODE (nelts) == INTEGER_CST | |
3710 | && TREE_CODE (TREE_OPERAND (probe, 1)) == INTEGER_CST); | |
a1488398 | 3711 | if (wi::to_widest (TREE_OPERAND (probe, 1)) == wi::to_widest (nelts)) |
bc2a38df JJ |
3712 | { |
3713 | diag_array_subscript (ctx, ary, TREE_OPERAND (probe, 1)); | |
3714 | *non_constant_p = true; | |
3715 | return t; | |
3716 | } | |
3717 | /* FALLTHRU */ | |
3718 | ||
3719 | case BIT_FIELD_REF: | |
3720 | case COMPONENT_REF: | |
3721 | probe = TREE_OPERAND (probe, 0); | |
3722 | continue; | |
3723 | ||
3724 | default: | |
3725 | probe = NULL_TREE; | |
3726 | continue; | |
3727 | } | |
3728 | } | |
3729 | ||
3f8e2835 JM |
3730 | if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (target), type)) |
3731 | { | |
3732 | /* For initialization of an empty base, the original target will be | |
3733 | *(base*)this, which the above evaluation resolves to the object | |
3734 | argument, which has the derived type rather than the base type. In | |
3735 | this situation, just evaluate the initializer and return, since | |
3736 | there's no actual data to store. */ | |
3737 | gcc_assert (is_empty_class (type)); | |
3738 | return cxx_eval_constant_expression (ctx, init, false, | |
3739 | non_constant_p, overflow_p); | |
3740 | } | |
3741 | ||
60813a46 JM |
3742 | /* And then find the underlying variable. */ |
3743 | vec<tree,va_gc> *refs = make_tree_vector(); | |
3744 | tree object = NULL_TREE; | |
3745 | for (tree probe = target; object == NULL_TREE; ) | |
3746 | { | |
3747 | switch (TREE_CODE (probe)) | |
3748 | { | |
3749 | case BIT_FIELD_REF: | |
3750 | case COMPONENT_REF: | |
3751 | case ARRAY_REF: | |
3752 | vec_safe_push (refs, TREE_OPERAND (probe, 1)); | |
3753 | vec_safe_push (refs, TREE_TYPE (probe)); | |
3754 | probe = TREE_OPERAND (probe, 0); | |
3755 | break; | |
3756 | ||
3757 | default: | |
3758 | object = probe; | |
60813a46 JM |
3759 | } |
3760 | } | |
3761 | ||
3762 | /* And then find/build up our initializer for the path to the subobject | |
3763 | we're initializing. */ | |
a1408b7e | 3764 | tree *valp; |
1e163090 JM |
3765 | if (object == ctx->object && VAR_P (object) |
3766 | && DECL_NAME (object) && ctx->call == NULL) | |
3767 | /* The variable we're building up an aggregate initializer for is outside | |
3768 | the constant-expression, so don't evaluate the store. We check | |
3769 | DECL_NAME to handle TARGET_EXPR temporaries, which are fair game. */ | |
3770 | valp = NULL; | |
3771 | else if (DECL_P (object)) | |
a1408b7e JM |
3772 | valp = ctx->values->get (object); |
3773 | else | |
3774 | valp = NULL; | |
60813a46 JM |
3775 | if (!valp) |
3776 | { | |
3777 | /* A constant-expression cannot modify objects from outside the | |
3778 | constant-expression. */ | |
2b3ab879 | 3779 | if (!ctx->quiet) |
64d6d399 | 3780 | error ("modification of %qE is not a constant expression", object); |
60813a46 JM |
3781 | *non_constant_p = true; |
3782 | return t; | |
3783 | } | |
3f8e2835 | 3784 | type = TREE_TYPE (object); |
c75ce530 | 3785 | bool no_zero_init = true; |
2d63bc39 JM |
3786 | |
3787 | vec<tree,va_gc> *ctors = make_tree_vector (); | |
60813a46 JM |
3788 | while (!refs->is_empty()) |
3789 | { | |
3790 | if (*valp == NULL_TREE) | |
3791 | { | |
3792 | *valp = build_constructor (type, NULL); | |
e8c48716 | 3793 | CONSTRUCTOR_NO_CLEARING (*valp) = no_zero_init; |
60813a46 | 3794 | } |
d6b46fca NS |
3795 | else if (TREE_CODE (*valp) == STRING_CST) |
3796 | { | |
3797 | /* An array was initialized with a string constant, and now | |
3798 | we're writing into one of its elements. Explode the | |
3799 | single initialization into a set of element | |
3800 | initializations. */ | |
3801 | gcc_assert (TREE_CODE (type) == ARRAY_TYPE); | |
3802 | ||
3803 | tree string = *valp; | |
3804 | tree elt_type = TREE_TYPE (type); | |
3805 | unsigned chars_per_elt = (TYPE_PRECISION (elt_type) | |
3806 | / TYPE_PRECISION (char_type_node)); | |
3807 | unsigned num_elts = TREE_STRING_LENGTH (string) / chars_per_elt; | |
3808 | tree ary_ctor = build_constructor (type, NULL); | |
3809 | ||
3810 | vec_safe_reserve (CONSTRUCTOR_ELTS (ary_ctor), num_elts); | |
3811 | for (unsigned ix = 0; ix != num_elts; ix++) | |
3812 | { | |
3813 | constructor_elt elt = | |
3814 | { | |
3815 | build_int_cst (size_type_node, ix), | |
3816 | extract_string_elt (string, chars_per_elt, ix) | |
3817 | }; | |
3818 | CONSTRUCTOR_ELTS (ary_ctor)->quick_push (elt); | |
3819 | } | |
3820 | ||
3821 | *valp = ary_ctor; | |
3822 | } | |
3823 | ||
c75ce530 JM |
3824 | /* If the value of object is already zero-initialized, any new ctors for |
3825 | subobjects will also be zero-initialized. */ | |
e8c48716 | 3826 | no_zero_init = CONSTRUCTOR_NO_CLEARING (*valp); |
60813a46 | 3827 | |
2d63bc39 JM |
3828 | vec_safe_push (ctors, *valp); |
3829 | ||
ceaaf873 | 3830 | enum tree_code code = TREE_CODE (type); |
60813a46 | 3831 | type = refs->pop(); |
ceaaf873 | 3832 | tree index = refs->pop(); |
60813a46 | 3833 | |
60813a46 | 3834 | constructor_elt *cep = NULL; |
ceaaf873 JM |
3835 | if (code == ARRAY_TYPE) |
3836 | { | |
3837 | HOST_WIDE_INT i | |
3838 | = find_array_ctor_elt (*valp, index, /*insert*/true); | |
3839 | gcc_assert (i >= 0); | |
3840 | cep = CONSTRUCTOR_ELT (*valp, i); | |
3841 | gcc_assert (TREE_CODE (cep->index) != RANGE_EXPR); | |
3842 | } | |
3843 | else | |
3844 | { | |
3845 | gcc_assert (TREE_CODE (index) == FIELD_DECL); | |
88504f34 NS |
3846 | |
3847 | /* We must keep the CONSTRUCTOR's ELTS in FIELD order. | |
3848 | Usually we meet initializers in that order, but it is | |
3849 | possible for base types to be placed not in program | |
3850 | order. */ | |
3851 | tree fields = TYPE_FIELDS (DECL_CONTEXT (index)); | |
3852 | unsigned HOST_WIDE_INT idx; | |
3853 | ||
5c97093b JM |
3854 | if (code == UNION_TYPE && CONSTRUCTOR_NELTS (*valp) |
3855 | && CONSTRUCTOR_ELT (*valp, 0)->index != index) | |
ed4ec9ce JJ |
3856 | { |
3857 | if (cxx_dialect < cxx2a) | |
3858 | { | |
3859 | if (!ctx->quiet) | |
3860 | error_at (cp_expr_loc_or_loc (t, input_location), | |
3861 | "change of the active member of a union " | |
3862 | "from %qD to %qD", | |
3863 | CONSTRUCTOR_ELT (*valp, 0)->index, | |
3864 | index); | |
3865 | *non_constant_p = true; | |
3866 | } | |
3867 | /* Changing active member. */ | |
3868 | vec_safe_truncate (CONSTRUCTOR_ELTS (*valp), 0); | |
c7f7c313 | 3869 | no_zero_init = true; |
ed4ec9ce | 3870 | } |
5c97093b | 3871 | |
88504f34 | 3872 | for (idx = 0; |
ceaaf873 | 3873 | vec_safe_iterate (CONSTRUCTOR_ELTS (*valp), idx, &cep); |
88504f34 | 3874 | idx++, fields = DECL_CHAIN (fields)) |
ceaaf873 | 3875 | { |
88504f34 NS |
3876 | if (index == cep->index) |
3877 | goto found; | |
3878 | ||
3879 | /* The field we're initializing must be on the field | |
3880 | list. Look to see if it is present before the | |
3881 | field the current ELT initializes. */ | |
3882 | for (; fields != cep->index; fields = DECL_CHAIN (fields)) | |
3883 | if (index == fields) | |
3884 | goto insert; | |
ceaaf873 | 3885 | } |
88504f34 NS |
3886 | |
3887 | /* We fell off the end of the CONSTRUCTOR, so insert a new | |
3888 | entry at the end. */ | |
3889 | insert: | |
3890 | { | |
3891 | constructor_elt ce = { index, NULL_TREE }; | |
3892 | ||
3893 | vec_safe_insert (CONSTRUCTOR_ELTS (*valp), idx, ce); | |
3894 | cep = CONSTRUCTOR_ELT (*valp, idx); | |
3895 | } | |
3896 | found:; | |
ceaaf873 | 3897 | } |
60813a46 JM |
3898 | valp = &cep->value; |
3899 | } | |
3900 | release_tree_vector (refs); | |
3901 | ||
e8b3c1bc | 3902 | if (!preeval) |
60813a46 JM |
3903 | { |
3904 | /* Create a new CONSTRUCTOR in case evaluation of the initializer | |
3905 | wants to modify it. */ | |
acb2970c | 3906 | if (*valp == NULL_TREE) |
73a84269 | 3907 | { |
664beaf2 | 3908 | *valp = build_constructor (type, NULL); |
e8c48716 | 3909 | CONSTRUCTOR_NO_CLEARING (*valp) = no_zero_init; |
73a84269 | 3910 | } |
664beaf2 | 3911 | new_ctx.ctor = *valp; |
60813a46 | 3912 | new_ctx.object = target; |
e8b3c1bc JM |
3913 | init = cxx_eval_constant_expression (&new_ctx, init, false, |
3914 | non_constant_p, overflow_p); | |
3915 | if (target == object) | |
3916 | /* The hash table might have moved since the get earlier. */ | |
3917 | valp = ctx->values->get (object); | |
60813a46 JM |
3918 | } |
3919 | ||
7574c916 | 3920 | /* Don't share a CONSTRUCTOR that might be changed later. */ |
0146e25f | 3921 | init = unshare_constructor (init); |
d96e8407 | 3922 | |
e8b3c1bc JM |
3923 | if (*valp && TREE_CODE (*valp) == CONSTRUCTOR |
3924 | && TREE_CODE (init) == CONSTRUCTOR) | |
acb2970c | 3925 | { |
d96e8407 JM |
3926 | /* An outer ctx->ctor might be pointing to *valp, so replace |
3927 | its contents. */ | |
3928 | CONSTRUCTOR_ELTS (*valp) = CONSTRUCTOR_ELTS (init); | |
3929 | TREE_CONSTANT (*valp) = TREE_CONSTANT (init); | |
3930 | TREE_SIDE_EFFECTS (*valp) = TREE_SIDE_EFFECTS (init); | |
e8c48716 JM |
3931 | CONSTRUCTOR_NO_CLEARING (*valp) |
3932 | = CONSTRUCTOR_NO_CLEARING (init); | |
acb2970c | 3933 | } |
60813a46 | 3934 | else |
d96e8407 | 3935 | *valp = init; |
2d63bc39 | 3936 | |
d96e8407 JM |
3937 | /* Update TREE_CONSTANT and TREE_SIDE_EFFECTS on enclosing |
3938 | CONSTRUCTORs, if any. */ | |
3939 | tree elt; | |
3940 | unsigned i; | |
3941 | bool c = TREE_CONSTANT (init); | |
3942 | bool s = TREE_SIDE_EFFECTS (init); | |
3943 | if (!c || s) | |
3944 | FOR_EACH_VEC_SAFE_ELT (ctors, i, elt) | |
3945 | { | |
3946 | if (!c) | |
3947 | TREE_CONSTANT (elt) = false; | |
3948 | if (s) | |
3949 | TREE_SIDE_EFFECTS (elt) = true; | |
3950 | } | |
2d63bc39 | 3951 | release_tree_vector (ctors); |
60813a46 JM |
3952 | |
3953 | if (*non_constant_p) | |
3954 | return t; | |
92a596e8 | 3955 | else if (lval) |
60813a46 JM |
3956 | return target; |
3957 | else | |
3bdf0a9b | 3958 | return init; |
60813a46 JM |
3959 | } |
3960 | ||
3961 | /* Evaluate a ++ or -- expression. */ | |
3962 | ||
3963 | static tree | |
3964 | cxx_eval_increment_expression (const constexpr_ctx *ctx, tree t, | |
92a596e8 | 3965 | bool lval, |
60813a46 JM |
3966 | bool *non_constant_p, bool *overflow_p) |
3967 | { | |
3968 | enum tree_code code = TREE_CODE (t); | |
3969 | tree type = TREE_TYPE (t); | |
3970 | tree op = TREE_OPERAND (t, 0); | |
3971 | tree offset = TREE_OPERAND (t, 1); | |
3972 | gcc_assert (TREE_CONSTANT (offset)); | |
3973 | ||
3974 | /* The operand as an lvalue. */ | |
2b3ab879 | 3975 | op = cxx_eval_constant_expression (ctx, op, true, |
5a804683 | 3976 | non_constant_p, overflow_p); |
60813a46 JM |
3977 | |
3978 | /* The operand as an rvalue. */ | |
84dd815f JM |
3979 | tree val |
3980 | = cxx_eval_constant_expression (ctx, op, false, | |
3981 | non_constant_p, overflow_p); | |
caee690e JM |
3982 | /* Don't VERIFY_CONSTANT if this might be dealing with a pointer to |
3983 | a local array in a constexpr function. */ | |
71a93b08 | 3984 | bool ptr = INDIRECT_TYPE_P (TREE_TYPE (val)); |
caee690e JM |
3985 | if (!ptr) |
3986 | VERIFY_CONSTANT (val); | |
60813a46 JM |
3987 | |
3988 | /* The modified value. */ | |
3989 | bool inc = (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR); | |
ac2f8d26 | 3990 | tree mod; |
71a93b08 | 3991 | if (INDIRECT_TYPE_P (type)) |
ac2f8d26 JM |
3992 | { |
3993 | /* The middle end requires pointers to use POINTER_PLUS_EXPR. */ | |
3994 | offset = convert_to_ptrofftype (offset); | |
3995 | if (!inc) | |
3996 | offset = fold_build1 (NEGATE_EXPR, TREE_TYPE (offset), offset); | |
3997 | mod = fold_build2 (POINTER_PLUS_EXPR, type, val, offset); | |
3998 | } | |
3999 | else | |
4000 | mod = fold_build2 (inc ? PLUS_EXPR : MINUS_EXPR, type, val, offset); | |
caee690e JM |
4001 | if (!ptr) |
4002 | VERIFY_CONSTANT (mod); | |
60813a46 JM |
4003 | |
4004 | /* Storing the modified value. */ | |
4005 | tree store = build2 (MODIFY_EXPR, type, op, mod); | |
2b3ab879 | 4006 | cxx_eval_constant_expression (ctx, store, |
5a804683 | 4007 | true, non_constant_p, overflow_p); |
60813a46 JM |
4008 | |
4009 | /* And the value of the expression. */ | |
4010 | if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR) | |
4011 | { | |
4012 | /* Prefix ops are lvalues. */ | |
92a596e8 | 4013 | if (lval) |
60813a46 JM |
4014 | return op; |
4015 | else | |
4016 | /* But we optimize when the caller wants an rvalue. */ | |
4017 | return mod; | |
4018 | } | |
4019 | else | |
4020 | /* Postfix ops are rvalues. */ | |
4021 | return val; | |
4022 | } | |
4023 | ||
56632b27 JM |
4024 | /* Predicates for the meaning of *jump_target. */ |
4025 | ||
4026 | static bool | |
4027 | returns (tree *jump_target) | |
4028 | { | |
4029 | return *jump_target | |
d49318d9 PC |
4030 | && (TREE_CODE (*jump_target) == RETURN_EXPR |
4031 | || (TREE_CODE (*jump_target) == LABEL_DECL | |
4032 | && LABEL_DECL_CDTOR (*jump_target))); | |
56632b27 JM |
4033 | } |
4034 | ||
4035 | static bool | |
4036 | breaks (tree *jump_target) | |
4037 | { | |
4038 | return *jump_target | |
06ec22b7 JM |
4039 | && ((TREE_CODE (*jump_target) == LABEL_DECL |
4040 | && LABEL_DECL_BREAK (*jump_target)) | |
3075affd | 4041 | || TREE_CODE (*jump_target) == BREAK_STMT |
06ec22b7 | 4042 | || TREE_CODE (*jump_target) == EXIT_EXPR); |
56632b27 JM |
4043 | } |
4044 | ||
4045 | static bool | |
4046 | continues (tree *jump_target) | |
4047 | { | |
4048 | return *jump_target | |
3075affd JM |
4049 | && ((TREE_CODE (*jump_target) == LABEL_DECL |
4050 | && LABEL_DECL_CONTINUE (*jump_target)) | |
4051 | || TREE_CODE (*jump_target) == CONTINUE_STMT); | |
4052 | ||
56632b27 JM |
4053 | } |
4054 | ||
4055 | static bool | |
4056 | switches (tree *jump_target) | |
4057 | { | |
4058 | return *jump_target | |
4059 | && TREE_CODE (*jump_target) == INTEGER_CST; | |
4060 | } | |
4061 | ||
4062 | /* Subroutine of cxx_eval_statement_list. Determine whether the statement | |
4b390698 JJ |
4063 | STMT matches *jump_target. If we're looking for a case label and we see |
4064 | the default label, note it in ctx->css_state. */ | |
56632b27 JM |
4065 | |
4066 | static bool | |
4b390698 | 4067 | label_matches (const constexpr_ctx *ctx, tree *jump_target, tree stmt) |
56632b27 | 4068 | { |
56632b27 JM |
4069 | switch (TREE_CODE (*jump_target)) |
4070 | { | |
4071 | case LABEL_DECL: | |
4072 | if (TREE_CODE (stmt) == LABEL_EXPR | |
4073 | && LABEL_EXPR_LABEL (stmt) == *jump_target) | |
4074 | return true; | |
4075 | break; | |
4076 | ||
4077 | case INTEGER_CST: | |
4078 | if (TREE_CODE (stmt) == CASE_LABEL_EXPR) | |
4079 | { | |
4b390698 | 4080 | gcc_assert (ctx->css_state != NULL); |
56632b27 | 4081 | if (!CASE_LOW (stmt)) |
4b390698 JJ |
4082 | { |
4083 | /* default: should appear just once in a SWITCH_EXPR | |
4084 | body (excluding nested SWITCH_EXPR). */ | |
4085 | gcc_assert (*ctx->css_state != css_default_seen); | |
4086 | /* When evaluating SWITCH_EXPR body for the second time, | |
4087 | return true for the default: label. */ | |
4088 | if (*ctx->css_state == css_default_processing) | |
4089 | return true; | |
4090 | *ctx->css_state = css_default_seen; | |
4091 | } | |
385ed708 JJ |
4092 | else if (CASE_HIGH (stmt)) |
4093 | { | |
4094 | if (tree_int_cst_le (CASE_LOW (stmt), *jump_target) | |
4095 | && tree_int_cst_le (*jump_target, CASE_HIGH (stmt))) | |
4096 | return true; | |
4097 | } | |
56632b27 JM |
4098 | else if (tree_int_cst_equal (*jump_target, CASE_LOW (stmt))) |
4099 | return true; | |
4100 | } | |
4101 | break; | |
4102 | ||
43574e4f JJ |
4103 | case BREAK_STMT: |
4104 | case CONTINUE_STMT: | |
4105 | /* These two are handled directly in cxx_eval_loop_expr by testing | |
4106 | breaks (jump_target) or continues (jump_target). */ | |
4107 | break; | |
4108 | ||
56632b27 JM |
4109 | default: |
4110 | gcc_unreachable (); | |
4111 | } | |
4112 | return false; | |
4113 | } | |
4114 | ||
4115 | /* Evaluate a STATEMENT_LIST for side-effects. Handles various jump | |
4116 | semantics, for switch, break, continue, and return. */ | |
4117 | ||
4118 | static tree | |
4119 | cxx_eval_statement_list (const constexpr_ctx *ctx, tree t, | |
56632b27 JM |
4120 | bool *non_constant_p, bool *overflow_p, |
4121 | tree *jump_target) | |
4122 | { | |
4123 | tree_stmt_iterator i; | |
58611fb6 | 4124 | tree local_target; |
345edb37 JJ |
4125 | /* In a statement-expression we want to return the last value. |
4126 | For empty statement expression return void_node. */ | |
4127 | tree r = void_node; | |
58611fb6 JM |
4128 | if (!jump_target) |
4129 | { | |
4130 | local_target = NULL_TREE; | |
4131 | jump_target = &local_target; | |
4132 | } | |
56632b27 JM |
4133 | for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i)) |
4134 | { | |
56632b27 | 4135 | tree stmt = tsi_stmt (i); |
0250ba58 MP |
4136 | /* We've found a continue, so skip everything until we reach |
4137 | the label its jumping to. */ | |
4138 | if (continues (jump_target)) | |
4139 | { | |
4140 | if (label_matches (ctx, jump_target, stmt)) | |
4141 | /* Found it. */ | |
4142 | *jump_target = NULL_TREE; | |
4143 | else | |
4144 | continue; | |
4145 | } | |
6ef72c36 JJ |
4146 | if (TREE_CODE (stmt) == DEBUG_BEGIN_STMT) |
4147 | continue; | |
58611fb6 JM |
4148 | r = cxx_eval_constant_expression (ctx, stmt, false, |
4149 | non_constant_p, overflow_p, | |
4150 | jump_target); | |
56632b27 JM |
4151 | if (*non_constant_p) |
4152 | break; | |
4153 | if (returns (jump_target) || breaks (jump_target)) | |
4154 | break; | |
4155 | } | |
58611fb6 | 4156 | return r; |
56632b27 JM |
4157 | } |
4158 | ||
4159 | /* Evaluate a LOOP_EXPR for side-effects. Handles break and return | |
4160 | semantics; continue semantics are covered by cxx_eval_statement_list. */ | |
4161 | ||
4162 | static tree | |
4163 | cxx_eval_loop_expr (const constexpr_ctx *ctx, tree t, | |
56632b27 JM |
4164 | bool *non_constant_p, bool *overflow_p, |
4165 | tree *jump_target) | |
4166 | { | |
39dce2b7 JM |
4167 | constexpr_ctx new_ctx = *ctx; |
4168 | ||
43574e4f | 4169 | tree body, cond = NULL_TREE, expr = NULL_TREE; |
5ec2cd9f | 4170 | int count = 0; |
43574e4f JJ |
4171 | switch (TREE_CODE (t)) |
4172 | { | |
4173 | case LOOP_EXPR: | |
4174 | body = LOOP_EXPR_BODY (t); | |
4175 | break; | |
4176 | case DO_STMT: | |
4177 | body = DO_BODY (t); | |
4178 | cond = DO_COND (t); | |
4179 | break; | |
4180 | case WHILE_STMT: | |
4181 | body = WHILE_BODY (t); | |
4182 | cond = WHILE_COND (t); | |
4183 | count = -1; | |
4184 | break; | |
4185 | case FOR_STMT: | |
4186 | if (FOR_INIT_STMT (t)) | |
4187 | cxx_eval_constant_expression (ctx, FOR_INIT_STMT (t), /*lval*/false, | |
4188 | non_constant_p, overflow_p, jump_target); | |
4189 | if (*non_constant_p) | |
4190 | return NULL_TREE; | |
4191 | body = FOR_BODY (t); | |
4192 | cond = FOR_COND (t); | |
4193 | expr = FOR_EXPR (t); | |
4194 | count = -1; | |
4195 | break; | |
4196 | default: | |
4197 | gcc_unreachable (); | |
4198 | } | |
0ee28590 | 4199 | auto_vec<tree, 10> save_exprs; |
43574e4f | 4200 | new_ctx.save_exprs = &save_exprs; |
d259b234 | 4201 | do |
56632b27 | 4202 | { |
43574e4f JJ |
4203 | if (count != -1) |
4204 | { | |
4205 | if (body) | |
4206 | cxx_eval_constant_expression (&new_ctx, body, /*lval*/false, | |
4207 | non_constant_p, overflow_p, | |
4208 | jump_target); | |
4209 | if (breaks (jump_target)) | |
4210 | { | |
4211 | *jump_target = NULL_TREE; | |
4212 | break; | |
4213 | } | |
39dce2b7 | 4214 | |
43574e4f JJ |
4215 | if (TREE_CODE (t) != LOOP_EXPR && continues (jump_target)) |
4216 | *jump_target = NULL_TREE; | |
4217 | ||
4218 | if (expr) | |
4219 | cxx_eval_constant_expression (&new_ctx, expr, /*lval*/false, | |
4220 | non_constant_p, overflow_p, | |
4221 | jump_target); | |
4222 | } | |
4223 | ||
4224 | if (cond) | |
4225 | { | |
4226 | tree res | |
4227 | = cxx_eval_constant_expression (&new_ctx, cond, /*lval*/false, | |
4228 | non_constant_p, overflow_p, | |
4229 | jump_target); | |
4230 | if (res) | |
4231 | { | |
4232 | if (verify_constant (res, ctx->quiet, non_constant_p, | |
4233 | overflow_p)) | |
4234 | break; | |
4235 | if (integer_zerop (res)) | |
4236 | break; | |
4237 | } | |
4238 | else | |
4239 | gcc_assert (*jump_target); | |
4240 | } | |
39dce2b7 JM |
4241 | |
4242 | /* Forget saved values of SAVE_EXPRs. */ | |
0ee28590 JJ |
4243 | unsigned int i; |
4244 | tree save_expr; | |
4245 | FOR_EACH_VEC_ELT (save_exprs, i, save_expr) | |
4246 | new_ctx.values->remove (save_expr); | |
4247 | save_exprs.truncate (0); | |
43574e4f | 4248 | |
5ec2cd9f JM |
4249 | if (++count >= constexpr_loop_limit) |
4250 | { | |
4251 | if (!ctx->quiet) | |
6bdfada4 | 4252 | error_at (cp_expr_loc_or_loc (t, input_location), |
84fa214d | 4253 | "%<constexpr%> loop iteration count exceeds limit of %d " |
a3f9f006 | 4254 | "(use %<-fconstexpr-loop-limit=%> to increase the limit)", |
5ec2cd9f JM |
4255 | constexpr_loop_limit); |
4256 | *non_constant_p = true; | |
4257 | break; | |
4258 | } | |
56632b27 | 4259 | } |
4b390698 JJ |
4260 | while (!returns (jump_target) |
4261 | && !breaks (jump_target) | |
43574e4f JJ |
4262 | && !continues (jump_target) |
4263 | && (!switches (jump_target) || count == 0) | |
4b390698 | 4264 | && !*non_constant_p); |
d259b234 | 4265 | |
43574e4f | 4266 | /* Forget saved values of SAVE_EXPRs. */ |
0ee28590 JJ |
4267 | unsigned int i; |
4268 | tree save_expr; | |
4269 | FOR_EACH_VEC_ELT (save_exprs, i, save_expr) | |
4270 | new_ctx.values->remove (save_expr); | |
39dce2b7 | 4271 | |
56632b27 JM |
4272 | return NULL_TREE; |
4273 | } | |
4274 | ||
4275 | /* Evaluate a SWITCH_EXPR for side-effects. Handles switch and break jump | |
4276 | semantics. */ | |
4277 | ||
4278 | static tree | |
4279 | cxx_eval_switch_expr (const constexpr_ctx *ctx, tree t, | |
56632b27 JM |
4280 | bool *non_constant_p, bool *overflow_p, |
4281 | tree *jump_target) | |
4282 | { | |
43574e4f JJ |
4283 | tree cond |
4284 | = TREE_CODE (t) == SWITCH_STMT ? SWITCH_STMT_COND (t) : SWITCH_COND (t); | |
2b3ab879 | 4285 | cond = cxx_eval_constant_expression (ctx, cond, false, |
5a804683 | 4286 | non_constant_p, overflow_p); |
56632b27 JM |
4287 | VERIFY_CONSTANT (cond); |
4288 | *jump_target = cond; | |
4289 | ||
43574e4f JJ |
4290 | tree body |
4291 | = TREE_CODE (t) == SWITCH_STMT ? SWITCH_STMT_BODY (t) : SWITCH_BODY (t); | |
4b390698 JJ |
4292 | constexpr_ctx new_ctx = *ctx; |
4293 | constexpr_switch_state css = css_default_not_seen; | |
4294 | new_ctx.css_state = &css; | |
4295 | cxx_eval_constant_expression (&new_ctx, body, false, | |
4296 | non_constant_p, overflow_p, jump_target); | |
4297 | if (switches (jump_target) && css == css_default_seen) | |
4298 | { | |
4299 | /* If the SWITCH_EXPR body has default: label, process it once again, | |
4300 | this time instructing label_matches to return true for default: | |
4301 | label on switches (jump_target). */ | |
4302 | css = css_default_processing; | |
4303 | cxx_eval_constant_expression (&new_ctx, body, false, | |
4304 | non_constant_p, overflow_p, jump_target); | |
4305 | } | |
56632b27 JM |
4306 | if (breaks (jump_target) || switches (jump_target)) |
4307 | *jump_target = NULL_TREE; | |
4308 | return NULL_TREE; | |
4309 | } | |
4310 | ||
89262ec6 JM |
4311 | /* Find the object of TYPE under initialization in CTX. */ |
4312 | ||
4313 | static tree | |
4314 | lookup_placeholder (const constexpr_ctx *ctx, bool lval, tree type) | |
4315 | { | |
fbd603c4 | 4316 | if (!ctx) |
89262ec6 JM |
4317 | return NULL_TREE; |
4318 | ||
4319 | /* We could use ctx->object unconditionally, but using ctx->ctor when we | |
4320 | can is a minor optimization. */ | |
fbd603c4 | 4321 | if (!lval && ctx->ctor && same_type_p (TREE_TYPE (ctx->ctor), type)) |
89262ec6 JM |
4322 | return ctx->ctor; |
4323 | ||
fbd603c4 JM |
4324 | if (!ctx->object) |
4325 | return NULL_TREE; | |
4326 | ||
89262ec6 JM |
4327 | /* Since an object cannot have a field of its own type, we can search outward |
4328 | from ctx->object to find the unique containing object of TYPE. */ | |
4329 | tree ob = ctx->object; | |
4330 | while (ob) | |
4331 | { | |
4332 | if (same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (ob), type)) | |
4333 | break; | |
4334 | if (handled_component_p (ob)) | |
4335 | ob = TREE_OPERAND (ob, 0); | |
4336 | else | |
4337 | ob = NULL_TREE; | |
4338 | } | |
4339 | ||
4340 | return ob; | |
4341 | } | |
4342 | ||
2d76680f PC |
4343 | /* Attempt to reduce the expression T to a constant value. |
4344 | On failure, issue diagnostic and return error_mark_node. */ | |
4345 | /* FIXME unify with c_fully_fold */ | |
60813a46 | 4346 | /* FIXME overflow_p is too global */ |
2d76680f PC |
4347 | |
4348 | static tree | |
3e605b20 | 4349 | cxx_eval_constant_expression (const constexpr_ctx *ctx, tree t, |
92a596e8 | 4350 | bool lval, |
56632b27 | 4351 | bool *non_constant_p, bool *overflow_p, |
3075affd | 4352 | tree *jump_target /* = NULL */) |
2d76680f | 4353 | { |
3e605b20 | 4354 | constexpr_ctx new_ctx; |
2d76680f PC |
4355 | tree r = t; |
4356 | ||
4b390698 JJ |
4357 | if (jump_target && *jump_target) |
4358 | { | |
4359 | /* If we are jumping, ignore all statements/expressions except those | |
4360 | that could have LABEL_EXPR or CASE_LABEL_EXPR in their bodies. */ | |
4361 | switch (TREE_CODE (t)) | |
4362 | { | |
4363 | case BIND_EXPR: | |
4364 | case STATEMENT_LIST: | |
4365 | case LOOP_EXPR: | |
4366 | case COND_EXPR: | |
43574e4f JJ |
4367 | case IF_STMT: |
4368 | case DO_STMT: | |
4369 | case WHILE_STMT: | |
4370 | case FOR_STMT: | |
4b390698 JJ |
4371 | break; |
4372 | case LABEL_EXPR: | |
4373 | case CASE_LABEL_EXPR: | |
4374 | if (label_matches (ctx, jump_target, t)) | |
4375 | /* Found it. */ | |
4376 | *jump_target = NULL_TREE; | |
4377 | return NULL_TREE; | |
4378 | default: | |
4379 | return NULL_TREE; | |
4380 | } | |
4381 | } | |
3075affd | 4382 | if (error_operand_p (t)) |
2d76680f PC |
4383 | { |
4384 | *non_constant_p = true; | |
4385 | return t; | |
4386 | } | |
4387 | if (CONSTANT_CLASS_P (t)) | |
4388 | { | |
61637db3 JJ |
4389 | if (TREE_OVERFLOW (t)) |
4390 | { | |
4391 | if (!ctx->quiet) | |
4392 | permerror (input_location, "overflow in constant expression"); | |
4393 | if (!flag_permissive || ctx->quiet) | |
4394 | *overflow_p = true; | |
4395 | } | |
8bada5cd MS |
4396 | |
4397 | if (TREE_CODE (t) == INTEGER_CST | |
9f613f06 | 4398 | && TYPE_PTR_P (TREE_TYPE (t)) |
8bada5cd MS |
4399 | && !integer_zerop (t)) |
4400 | { | |
4401 | if (!ctx->quiet) | |
4402 | error ("value %qE of type %qT is not a constant expression", | |
4403 | t, TREE_TYPE (t)); | |
4404 | *non_constant_p = true; | |
4405 | } | |
4406 | ||
2d76680f PC |
4407 | return t; |
4408 | } | |
2d76680f | 4409 | |
a15ffa22 JJ |
4410 | /* Avoid excessively long constexpr evaluations. */ |
4411 | if (!location_wrapper_p (t) | |
4412 | && ++*ctx->constexpr_ops_count >= constexpr_ops_limit) | |
4413 | { | |
4414 | if (!ctx->quiet) | |
4415 | error_at (cp_expr_loc_or_loc (t, input_location), | |
4416 | "%<constexpr%> evaluation operation count exceeds limit of " | |
4417 | "%wd (use -fconstexpr-ops-limit= to increase the limit)", | |
4418 | constexpr_ops_limit); | |
4419 | *ctx->constexpr_ops_count = INTTYPE_MINIMUM (HOST_WIDE_INT); | |
4420 | *non_constant_p = true; | |
4421 | return t; | |
4422 | } | |
4423 | ||
8bada5cd MS |
4424 | tree_code tcode = TREE_CODE (t); |
4425 | switch (tcode) | |
2d76680f | 4426 | { |
60813a46 | 4427 | case RESULT_DECL: |
92a596e8 | 4428 | if (lval) |
60813a46 JM |
4429 | return t; |
4430 | /* We ask for an rvalue for the RESULT_DECL when indirecting | |
bf66b9b4 AH |
4431 | through an invisible reference, or in named return value |
4432 | optimization. */ | |
1efb1dc2 MP |
4433 | if (tree *p = ctx->values->get (t)) |
4434 | return *p; | |
4435 | else | |
4436 | { | |
4437 | if (!ctx->quiet) | |
4438 | error ("%qE is not a constant expression", t); | |
4439 | *non_constant_p = true; | |
4440 | } | |
4441 | break; | |
60813a46 | 4442 | |
2d76680f | 4443 | case VAR_DECL: |
70f40fea | 4444 | if (DECL_HAS_VALUE_EXPR_P (t)) |
c59fa7ea JM |
4445 | { |
4446 | if (is_normal_capture_proxy (t) | |
4447 | && current_function_decl == DECL_CONTEXT (t)) | |
4448 | { | |
4449 | /* Function parms aren't constexpr within the function | |
4450 | definition, so don't try to look at the closure. But if the | |
4451 | captured variable is constant, try to evaluate it directly. */ | |
4452 | r = DECL_CAPTURED_VARIABLE (t); | |
4453 | tree type = TREE_TYPE (t); | |
4454 | if (TYPE_REF_P (type) != TYPE_REF_P (TREE_TYPE (r))) | |
4455 | { | |
4456 | /* Adjust r to match the reference-ness of t. */ | |
4457 | if (TYPE_REF_P (type)) | |
4458 | r = build_address (r); | |
4459 | else | |
4460 | r = convert_from_reference (r); | |
4461 | } | |
4462 | } | |
4463 | else | |
4464 | r = DECL_VALUE_EXPR (t); | |
4465 | return cxx_eval_constant_expression (ctx, r, lval, non_constant_p, | |
4466 | overflow_p); | |
4467 | } | |
191816a3 | 4468 | /* fall through */ |
7c83622c JM |
4469 | case CONST_DECL: |
4470 | /* We used to not check lval for CONST_DECL, but darwin.c uses | |
4471 | CONST_DECL for aggregate constants. */ | |
92a596e8 | 4472 | if (lval) |
2d76680f | 4473 | return t; |
f4fce183 | 4474 | if (COMPLETE_TYPE_P (TREE_TYPE (t)) |
dbcd32f8 | 4475 | && is_really_empty_class (TREE_TYPE (t), /*ignore_vptr*/false)) |
7dc2b4a2 JM |
4476 | { |
4477 | /* If the class is empty, we aren't actually loading anything. */ | |
4478 | r = build_constructor (TREE_TYPE (t), NULL); | |
4479 | TREE_CONSTANT (r) = true; | |
4480 | } | |
4481 | else if (ctx->strict) | |
69eb4fde JM |
4482 | r = decl_really_constant_value (t); |
4483 | else | |
4484 | r = decl_constant_value (t); | |
2d76680f PC |
4485 | if (TREE_CODE (r) == TARGET_EXPR |
4486 | && TREE_CODE (TARGET_EXPR_INITIAL (r)) == CONSTRUCTOR) | |
4487 | r = TARGET_EXPR_INITIAL (r); | |
56a6f1d3 | 4488 | if (VAR_P (r)) |
3e605b20 | 4489 | if (tree *p = ctx->values->get (r)) |
bd8f5bb2 MP |
4490 | if (*p != NULL_TREE) |
4491 | r = *p; | |
2d76680f PC |
4492 | if (DECL_P (r)) |
4493 | { | |
2b3ab879 | 4494 | if (!ctx->quiet) |
2d76680f PC |
4495 | non_const_var_error (r); |
4496 | *non_constant_p = true; | |
4497 | } | |
4498 | break; | |
4499 | ||
96a95ac1 AO |
4500 | case DEBUG_BEGIN_STMT: |
4501 | /* ??? It might be nice to retain this information somehow, so | |
4502 | as to be able to step into a constexpr function call. */ | |
4503 | /* Fall through. */ | |
4504 | ||
2d76680f PC |
4505 | case FUNCTION_DECL: |
4506 | case TEMPLATE_DECL: | |
4507 | case LABEL_DECL: | |
56632b27 JM |
4508 | case LABEL_EXPR: |
4509 | case CASE_LABEL_EXPR: | |
4b390698 | 4510 | case PREDICT_EXPR: |
2d76680f PC |
4511 | return t; |
4512 | ||
4513 | case PARM_DECL: | |
9f613f06 | 4514 | if (lval && !TYPE_REF_P (TREE_TYPE (t))) |
60813a46 JM |
4515 | /* glvalue use. */; |
4516 | else if (tree *p = ctx->values->get (r)) | |
4517 | r = *p; | |
92a596e8 | 4518 | else if (lval) |
2d76680f | 4519 | /* Defer in case this is only used for its type. */; |
9f613f06 | 4520 | else if (TYPE_REF_P (TREE_TYPE (t))) |
f2acb8ad | 4521 | /* Defer, there's no lvalue->rvalue conversion. */; |
1c2f613f | 4522 | else if (COMPLETE_TYPE_P (TREE_TYPE (t)) |
dbcd32f8 | 4523 | && is_really_empty_class (TREE_TYPE (t), /*ignore_vptr*/false)) |
052beba4 JM |
4524 | { |
4525 | /* If the class is empty, we aren't actually loading anything. */ | |
4526 | r = build_constructor (TREE_TYPE (t), NULL); | |
4527 | TREE_CONSTANT (r) = true; | |
4528 | } | |
2d76680f PC |
4529 | else |
4530 | { | |
2b3ab879 | 4531 | if (!ctx->quiet) |
2d76680f PC |
4532 | error ("%qE is not a constant expression", t); |
4533 | *non_constant_p = true; | |
4534 | } | |
4535 | break; | |
4536 | ||
4537 | case CALL_EXPR: | |
4538 | case AGGR_INIT_EXPR: | |
92a596e8 | 4539 | r = cxx_eval_call_expression (ctx, t, lval, |
2d76680f PC |
4540 | non_constant_p, overflow_p); |
4541 | break; | |
4542 | ||
60813a46 JM |
4543 | case DECL_EXPR: |
4544 | { | |
4545 | r = DECL_EXPR_DECL (t); | |
43574e4f JJ |
4546 | if (TREE_CODE (r) == USING_DECL) |
4547 | { | |
4548 | r = void_node; | |
4549 | break; | |
4550 | } | |
60813a46 JM |
4551 | if (AGGREGATE_TYPE_P (TREE_TYPE (r)) |
4552 | || VECTOR_TYPE_P (TREE_TYPE (r))) | |
4553 | { | |
4554 | new_ctx = *ctx; | |
4555 | new_ctx.object = r; | |
4556 | new_ctx.ctor = build_constructor (TREE_TYPE (r), NULL); | |
e8c48716 | 4557 | CONSTRUCTOR_NO_CLEARING (new_ctx.ctor) = true; |
60813a46 JM |
4558 | new_ctx.values->put (r, new_ctx.ctor); |
4559 | ctx = &new_ctx; | |
4560 | } | |
4561 | ||
4562 | if (tree init = DECL_INITIAL (r)) | |
4563 | { | |
4564 | init = cxx_eval_constant_expression (ctx, init, | |
2b3ab879 | 4565 | false, |
5a804683 | 4566 | non_constant_p, overflow_p); |
7f0e23e9 | 4567 | /* Don't share a CONSTRUCTOR that might be changed. */ |
0146e25f | 4568 | init = unshare_constructor (init); |
60813a46 JM |
4569 | ctx->values->put (r, init); |
4570 | } | |
4571 | else if (ctx == &new_ctx) | |
4572 | /* We gave it a CONSTRUCTOR above. */; | |
4573 | else | |
4574 | ctx->values->put (r, NULL_TREE); | |
4575 | } | |
4576 | break; | |
4577 | ||
2d76680f PC |
4578 | case TARGET_EXPR: |
4579 | if (!literal_type_p (TREE_TYPE (t))) | |
4580 | { | |
2b3ab879 | 4581 | if (!ctx->quiet) |
2d76680f | 4582 | { |
097f82ec | 4583 | auto_diagnostic_group d; |
2d76680f PC |
4584 | error ("temporary of non-literal type %qT in a " |
4585 | "constant expression", TREE_TYPE (t)); | |
4586 | explain_non_literal_class (TREE_TYPE (t)); | |
4587 | } | |
4588 | *non_constant_p = true; | |
4589 | break; | |
4590 | } | |
3e605b20 JM |
4591 | if ((AGGREGATE_TYPE_P (TREE_TYPE (t)) || VECTOR_TYPE_P (TREE_TYPE (t)))) |
4592 | { | |
4593 | /* We're being expanded without an explicit target, so start | |
4594 | initializing a new object; expansion with an explicit target | |
4595 | strips the TARGET_EXPR before we get here. */ | |
4596 | new_ctx = *ctx; | |
4597 | new_ctx.ctor = build_constructor (TREE_TYPE (t), NULL); | |
e8c48716 | 4598 | CONSTRUCTOR_NO_CLEARING (new_ctx.ctor) = true; |
3e605b20 JM |
4599 | new_ctx.object = TARGET_EXPR_SLOT (t); |
4600 | ctx->values->put (new_ctx.object, new_ctx.ctor); | |
4601 | ctx = &new_ctx; | |
4602 | } | |
92a596e8 | 4603 | /* Pass false for 'lval' because this indicates |
2d76680f | 4604 | initialization of a temporary. */ |
3e605b20 | 4605 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), |
2b3ab879 | 4606 | false, |
5a804683 | 4607 | non_constant_p, overflow_p); |
2d76680f PC |
4608 | if (!*non_constant_p) |
4609 | /* Adjust the type of the result to the type of the temporary. */ | |
4610 | r = adjust_temp_type (TREE_TYPE (t), r); | |
92a596e8 | 4611 | if (lval) |
f2acb8ad JM |
4612 | { |
4613 | tree slot = TARGET_EXPR_SLOT (t); | |
0146e25f | 4614 | r = unshare_constructor (r); |
f2acb8ad JM |
4615 | ctx->values->put (slot, r); |
4616 | return slot; | |
4617 | } | |
2d76680f PC |
4618 | break; |
4619 | ||
60813a46 | 4620 | case INIT_EXPR: |
60813a46 | 4621 | case MODIFY_EXPR: |
4b390698 | 4622 | gcc_assert (jump_target == NULL || *jump_target == NULL_TREE); |
92a596e8 | 4623 | r = cxx_eval_store_expression (ctx, t, lval, |
60813a46 JM |
4624 | non_constant_p, overflow_p); |
4625 | break; | |
4626 | ||
2d76680f | 4627 | case SCOPE_REF: |
3e605b20 | 4628 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), |
92a596e8 | 4629 | lval, |
5a804683 | 4630 | non_constant_p, overflow_p); |
2d76680f PC |
4631 | break; |
4632 | ||
4633 | case RETURN_EXPR: | |
75e0295b MP |
4634 | if (TREE_OPERAND (t, 0) != NULL_TREE) |
4635 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), | |
4636 | lval, | |
4637 | non_constant_p, overflow_p); | |
43574e4f JJ |
4638 | /* FALLTHRU */ |
4639 | case BREAK_STMT: | |
4640 | case CONTINUE_STMT: | |
019e0ae8 MP |
4641 | if (jump_target) |
4642 | *jump_target = t; | |
4643 | else | |
4644 | { | |
4645 | /* Can happen with ({ return true; }) && false; passed to | |
4646 | maybe_constant_value. There is nothing to jump over in this | |
4647 | case, and the bug will be diagnosed later. */ | |
4648 | gcc_assert (ctx->quiet); | |
4649 | *non_constant_p = true; | |
4650 | } | |
56632b27 JM |
4651 | break; |
4652 | ||
cabaf50a JM |
4653 | case SAVE_EXPR: |
4654 | /* Avoid evaluating a SAVE_EXPR more than once. */ | |
4655 | if (tree *p = ctx->values->get (t)) | |
4656 | r = *p; | |
4657 | else | |
4658 | { | |
12d9ce19 | 4659 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), false, |
cabaf50a JM |
4660 | non_constant_p, overflow_p); |
4661 | ctx->values->put (t, r); | |
39dce2b7 | 4662 | if (ctx->save_exprs) |
0ee28590 | 4663 | ctx->save_exprs->safe_push (t); |
cabaf50a JM |
4664 | } |
4665 | break; | |
4666 | ||
2d76680f PC |
4667 | case NON_LVALUE_EXPR: |
4668 | case TRY_CATCH_EXPR: | |
769430b2 | 4669 | case TRY_BLOCK: |
2d76680f PC |
4670 | case CLEANUP_POINT_EXPR: |
4671 | case MUST_NOT_THROW_EXPR: | |
60813a46 JM |
4672 | case EXPR_STMT: |
4673 | case EH_SPEC_BLOCK: | |
3e605b20 | 4674 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), |
92a596e8 | 4675 | lval, |
56632b27 JM |
4676 | non_constant_p, overflow_p, |
4677 | jump_target); | |
2d76680f PC |
4678 | break; |
4679 | ||
769430b2 JM |
4680 | case TRY_FINALLY_EXPR: |
4681 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval, | |
4682 | non_constant_p, overflow_p, | |
4683 | jump_target); | |
4684 | if (!*non_constant_p) | |
4685 | /* Also evaluate the cleanup. */ | |
4686 | cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), true, | |
4687 | non_constant_p, overflow_p, | |
4688 | jump_target); | |
4689 | break; | |
4690 | ||
43574e4f JJ |
4691 | case CLEANUP_STMT: |
4692 | r = cxx_eval_constant_expression (ctx, CLEANUP_BODY (t), lval, | |
4693 | non_constant_p, overflow_p, | |
4694 | jump_target); | |
4695 | if (!CLEANUP_EH_ONLY (t) && !*non_constant_p) | |
4696 | /* Also evaluate the cleanup. */ | |
4697 | cxx_eval_constant_expression (ctx, CLEANUP_EXPR (t), true, | |
4698 | non_constant_p, overflow_p, | |
4699 | jump_target); | |
4700 | break; | |
4701 | ||
2d76680f PC |
4702 | /* These differ from cxx_eval_unary_expression in that this doesn't |
4703 | check for a constant operand or result; an address can be | |
4704 | constant without its operand being, and vice versa. */ | |
cda0a029 | 4705 | case MEM_REF: |
2d76680f | 4706 | case INDIRECT_REF: |
92a596e8 | 4707 | r = cxx_eval_indirect_ref (ctx, t, lval, |
2d76680f PC |
4708 | non_constant_p, overflow_p); |
4709 | break; | |
4710 | ||
4711 | case ADDR_EXPR: | |
4712 | { | |
4713 | tree oldop = TREE_OPERAND (t, 0); | |
3e605b20 | 4714 | tree op = cxx_eval_constant_expression (ctx, oldop, |
92a596e8 | 4715 | /*lval*/true, |
5a804683 | 4716 | non_constant_p, overflow_p); |
2d76680f PC |
4717 | /* Don't VERIFY_CONSTANT here. */ |
4718 | if (*non_constant_p) | |
4719 | return t; | |
f2acb8ad | 4720 | gcc_checking_assert (TREE_CODE (op) != CONSTRUCTOR); |
2d76680f PC |
4721 | /* This function does more aggressive folding than fold itself. */ |
4722 | r = build_fold_addr_expr_with_type (op, TREE_TYPE (t)); | |
4723 | if (TREE_CODE (r) == ADDR_EXPR && TREE_OPERAND (r, 0) == oldop) | |
4724 | return t; | |
4725 | break; | |
4726 | } | |
4727 | ||
4728 | case REALPART_EXPR: | |
4729 | case IMAGPART_EXPR: | |
87713c6a JJ |
4730 | if (lval) |
4731 | { | |
4732 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval, | |
4733 | non_constant_p, overflow_p); | |
4734 | if (r == error_mark_node) | |
4735 | ; | |
4736 | else if (r == TREE_OPERAND (t, 0)) | |
4737 | r = t; | |
4738 | else | |
4739 | r = fold_build1 (TREE_CODE (t), TREE_TYPE (t), r); | |
4740 | break; | |
4741 | } | |
4742 | /* FALLTHRU */ | |
2d76680f PC |
4743 | case CONJ_EXPR: |
4744 | case FIX_TRUNC_EXPR: | |
4745 | case FLOAT_EXPR: | |
4746 | case NEGATE_EXPR: | |
4747 | case ABS_EXPR: | |
e28fadbc | 4748 | case ABSU_EXPR: |
2d76680f PC |
4749 | case BIT_NOT_EXPR: |
4750 | case TRUTH_NOT_EXPR: | |
4751 | case FIXED_CONVERT_EXPR: | |
92a596e8 | 4752 | r = cxx_eval_unary_expression (ctx, t, lval, |
2d76680f PC |
4753 | non_constant_p, overflow_p); |
4754 | break; | |
4755 | ||
4756 | case SIZEOF_EXPR: | |
43574e4f JJ |
4757 | r = cxx_eval_constant_expression (ctx, fold_sizeof_expr (t), lval, |
4758 | non_constant_p, overflow_p, | |
4759 | jump_target); | |
2d76680f PC |
4760 | break; |
4761 | ||
4762 | case COMPOUND_EXPR: | |
4763 | { | |
4764 | /* check_return_expr sometimes wraps a TARGET_EXPR in a | |
4765 | COMPOUND_EXPR; don't get confused. Also handle EMPTY_CLASS_EXPR | |
4766 | introduced by build_call_a. */ | |
4767 | tree op0 = TREE_OPERAND (t, 0); | |
4768 | tree op1 = TREE_OPERAND (t, 1); | |
4769 | STRIP_NOPS (op1); | |
4770 | if ((TREE_CODE (op0) == TARGET_EXPR && op1 == TARGET_EXPR_SLOT (op0)) | |
4771 | || TREE_CODE (op1) == EMPTY_CLASS_EXPR) | |
2b3ab879 | 4772 | r = cxx_eval_constant_expression (ctx, op0, |
92a596e8 | 4773 | lval, non_constant_p, overflow_p, |
56632b27 | 4774 | jump_target); |
2d76680f PC |
4775 | else |
4776 | { | |
4777 | /* Check that the LHS is constant and then discard it. */ | |
2b3ab879 | 4778 | cxx_eval_constant_expression (ctx, op0, |
12d9ce19 | 4779 | true, non_constant_p, overflow_p, |
56632b27 | 4780 | jump_target); |
06ec22b7 JM |
4781 | if (*non_constant_p) |
4782 | return t; | |
2d76680f | 4783 | op1 = TREE_OPERAND (t, 1); |
2b3ab879 | 4784 | r = cxx_eval_constant_expression (ctx, op1, |
92a596e8 | 4785 | lval, non_constant_p, overflow_p, |
56632b27 | 4786 | jump_target); |
2d76680f PC |
4787 | } |
4788 | } | |
4789 | break; | |
4790 | ||
4791 | case POINTER_PLUS_EXPR: | |
1af4ebf5 | 4792 | case POINTER_DIFF_EXPR: |
2d76680f PC |
4793 | case PLUS_EXPR: |
4794 | case MINUS_EXPR: | |
4795 | case MULT_EXPR: | |
4796 | case TRUNC_DIV_EXPR: | |
4797 | case CEIL_DIV_EXPR: | |
4798 | case FLOOR_DIV_EXPR: | |
4799 | case ROUND_DIV_EXPR: | |
4800 | case TRUNC_MOD_EXPR: | |
4801 | case CEIL_MOD_EXPR: | |
4802 | case ROUND_MOD_EXPR: | |
4803 | case RDIV_EXPR: | |
4804 | case EXACT_DIV_EXPR: | |
4805 | case MIN_EXPR: | |
4806 | case MAX_EXPR: | |
4807 | case LSHIFT_EXPR: | |
4808 | case RSHIFT_EXPR: | |
4809 | case LROTATE_EXPR: | |
4810 | case RROTATE_EXPR: | |
4811 | case BIT_IOR_EXPR: | |
4812 | case BIT_XOR_EXPR: | |
4813 | case BIT_AND_EXPR: | |
4814 | case TRUTH_XOR_EXPR: | |
4815 | case LT_EXPR: | |
4816 | case LE_EXPR: | |
4817 | case GT_EXPR: | |
4818 | case GE_EXPR: | |
4819 | case EQ_EXPR: | |
4820 | case NE_EXPR: | |
4821 | case UNORDERED_EXPR: | |
4822 | case ORDERED_EXPR: | |
4823 | case UNLT_EXPR: | |
4824 | case UNLE_EXPR: | |
4825 | case UNGT_EXPR: | |
4826 | case UNGE_EXPR: | |
4827 | case UNEQ_EXPR: | |
4828 | case LTGT_EXPR: | |
4829 | case RANGE_EXPR: | |
4830 | case COMPLEX_EXPR: | |
92a596e8 | 4831 | r = cxx_eval_binary_expression (ctx, t, lval, |
2d76680f PC |
4832 | non_constant_p, overflow_p); |
4833 | break; | |
4834 | ||
4835 | /* fold can introduce non-IF versions of these; still treat them as | |
4836 | short-circuiting. */ | |
4837 | case TRUTH_AND_EXPR: | |
4838 | case TRUTH_ANDIF_EXPR: | |
3e605b20 | 4839 | r = cxx_eval_logical_expression (ctx, t, boolean_false_node, |
2d76680f | 4840 | boolean_true_node, |
92a596e8 | 4841 | lval, |
2d76680f PC |
4842 | non_constant_p, overflow_p); |
4843 | break; | |
4844 | ||
4845 | case TRUTH_OR_EXPR: | |
4846 | case TRUTH_ORIF_EXPR: | |
3e605b20 | 4847 | r = cxx_eval_logical_expression (ctx, t, boolean_true_node, |
2d76680f | 4848 | boolean_false_node, |
92a596e8 | 4849 | lval, |
2d76680f PC |
4850 | non_constant_p, overflow_p); |
4851 | break; | |
4852 | ||
4853 | case ARRAY_REF: | |
92a596e8 | 4854 | r = cxx_eval_array_reference (ctx, t, lval, |
2d76680f PC |
4855 | non_constant_p, overflow_p); |
4856 | break; | |
4857 | ||
4858 | case COMPONENT_REF: | |
4859 | if (is_overloaded_fn (t)) | |
4860 | { | |
4861 | /* We can only get here in checking mode via | |
4862 | build_non_dependent_expr, because any expression that | |
4863 | calls or takes the address of the function will have | |
4864 | pulled a FUNCTION_DECL out of the COMPONENT_REF. */ | |
2b3ab879 | 4865 | gcc_checking_assert (ctx->quiet || errorcount); |
2d76680f PC |
4866 | *non_constant_p = true; |
4867 | return t; | |
4868 | } | |
92a596e8 | 4869 | r = cxx_eval_component_reference (ctx, t, lval, |
2d76680f PC |
4870 | non_constant_p, overflow_p); |
4871 | break; | |
4872 | ||
4873 | case BIT_FIELD_REF: | |
92a596e8 | 4874 | r = cxx_eval_bit_field_ref (ctx, t, lval, |
2d76680f PC |
4875 | non_constant_p, overflow_p); |
4876 | break; | |
4877 | ||
4878 | case COND_EXPR: | |
43574e4f | 4879 | case IF_STMT: |
4b390698 JJ |
4880 | if (jump_target && *jump_target) |
4881 | { | |
e9fa2f6d | 4882 | tree orig_jump = *jump_target; |
43574e4f JJ |
4883 | tree arg = ((TREE_CODE (t) != IF_STMT || TREE_OPERAND (t, 1)) |
4884 | ? TREE_OPERAND (t, 1) : void_node); | |
4b390698 JJ |
4885 | /* When jumping to a label, the label might be either in the |
4886 | then or else blocks, so process then block first in skipping | |
4887 | mode first, and if we are still in the skipping mode at its end, | |
4888 | process the else block too. */ | |
43574e4f JJ |
4889 | r = cxx_eval_constant_expression (ctx, arg, lval, non_constant_p, |
4890 | overflow_p, jump_target); | |
e9fa2f6d MP |
4891 | /* It's possible that we found the label in the then block. But |
4892 | it could have been followed by another jumping statement, e.g. | |
4893 | say we're looking for case 1: | |
4894 | if (cond) | |
4895 | { | |
4896 | // skipped statements | |
4897 | case 1:; // clears up *jump_target | |
4898 | return 1; // and sets it to a RETURN_EXPR | |
4899 | } | |
4900 | else { ... } | |
4901 | in which case we need not go looking to the else block. | |
4902 | (goto is not allowed in a constexpr function.) */ | |
4903 | if (*jump_target == orig_jump) | |
43574e4f JJ |
4904 | { |
4905 | arg = ((TREE_CODE (t) != IF_STMT || TREE_OPERAND (t, 2)) | |
4906 | ? TREE_OPERAND (t, 2) : void_node); | |
4907 | r = cxx_eval_constant_expression (ctx, arg, lval, non_constant_p, | |
4908 | overflow_p, jump_target); | |
4909 | } | |
4b390698 JJ |
4910 | break; |
4911 | } | |
92a596e8 | 4912 | r = cxx_eval_conditional_expression (ctx, t, lval, |
56632b27 JM |
4913 | non_constant_p, overflow_p, |
4914 | jump_target); | |
2d76680f | 4915 | break; |
f370e36d JJ |
4916 | case VEC_COND_EXPR: |
4917 | r = cxx_eval_vector_conditional_expression (ctx, t, non_constant_p, | |
4918 | overflow_p); | |
4919 | break; | |
2d76680f PC |
4920 | |
4921 | case CONSTRUCTOR: | |
35d87f01 | 4922 | if (TREE_CONSTANT (t) && reduced_constant_expression_p (t)) |
2d63bc39 JM |
4923 | { |
4924 | /* Don't re-process a constant CONSTRUCTOR, but do fold it to | |
4925 | VECTOR_CST if applicable. */ | |
ac9ec198 | 4926 | verify_constructor_flags (t); |
2d63bc39 JM |
4927 | if (TREE_CONSTANT (t)) |
4928 | return fold (t); | |
4929 | } | |
92a596e8 | 4930 | r = cxx_eval_bare_aggregate (ctx, t, lval, |
2d76680f PC |
4931 | non_constant_p, overflow_p); |
4932 | break; | |
4933 | ||
4934 | case VEC_INIT_EXPR: | |
4935 | /* We can get this in a defaulted constructor for a class with a | |
4936 | non-static data member of array type. Either the initializer will | |
4937 | be NULL, meaning default-initialization, or it will be an lvalue | |
4938 | or xvalue of the same type, meaning direct-initialization from the | |
4939 | corresponding member. */ | |
92a596e8 | 4940 | r = cxx_eval_vec_init (ctx, t, lval, |
2d76680f PC |
4941 | non_constant_p, overflow_p); |
4942 | break; | |
4943 | ||
2d76680f | 4944 | case VEC_PERM_EXPR: |
92a596e8 | 4945 | r = cxx_eval_trinary_expression (ctx, t, lval, |
2d76680f PC |
4946 | non_constant_p, overflow_p); |
4947 | break; | |
4948 | ||
7d75ea04 JJ |
4949 | case NOP_EXPR: |
4950 | if (REINTERPRET_CAST_P (t)) | |
4951 | { | |
4952 | if (!ctx->quiet) | |
6bdfada4 | 4953 | error_at (cp_expr_loc_or_loc (t, input_location), |
7d75ea04 JJ |
4954 | "a reinterpret_cast is not a constant expression"); |
4955 | *non_constant_p = true; | |
4956 | return t; | |
4957 | } | |
4958 | /* FALLTHROUGH. */ | |
2d76680f PC |
4959 | case CONVERT_EXPR: |
4960 | case VIEW_CONVERT_EXPR: | |
cda0a029 | 4961 | case UNARY_PLUS_EXPR: |
2d76680f PC |
4962 | { |
4963 | tree oldop = TREE_OPERAND (t, 0); | |
cda0a029 | 4964 | |
3e605b20 | 4965 | tree op = cxx_eval_constant_expression (ctx, oldop, |
92a596e8 | 4966 | lval, |
5a804683 | 4967 | non_constant_p, overflow_p); |
2d76680f PC |
4968 | if (*non_constant_p) |
4969 | return t; | |
dcdbc004 JM |
4970 | tree type = TREE_TYPE (t); |
4971 | if (TREE_CODE (op) == PTRMEM_CST | |
4972 | && !TYPE_PTRMEM_P (type)) | |
4973 | op = cplus_expand_constant (op); | |
7d75ea04 | 4974 | |
05bf54c3 MP |
4975 | if (TREE_CODE (op) == PTRMEM_CST && tcode == NOP_EXPR) |
4976 | { | |
7d75ea04 JJ |
4977 | if (!same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (op)) |
4978 | && !can_convert_qual (type, op)) | |
4979 | op = cplus_expand_constant (op); | |
4980 | return cp_fold_convert (type, op); | |
05bf54c3 | 4981 | } |
8bada5cd | 4982 | |
71a93b08 | 4983 | if (INDIRECT_TYPE_P (type) && TREE_CODE (op) == INTEGER_CST) |
2d76680f | 4984 | { |
8bada5cd MS |
4985 | if (integer_zerop (op)) |
4986 | { | |
9f613f06 | 4987 | if (TYPE_REF_P (type)) |
8bada5cd MS |
4988 | { |
4989 | if (!ctx->quiet) | |
6bdfada4 | 4990 | error_at (cp_expr_loc_or_loc (t, input_location), |
8bada5cd MS |
4991 | "dereferencing a null pointer"); |
4992 | *non_constant_p = true; | |
4993 | return t; | |
4994 | } | |
9f613f06 | 4995 | else if (TYPE_PTR_P (TREE_TYPE (op))) |
8bada5cd MS |
4996 | { |
4997 | tree from = TREE_TYPE (op); | |
4998 | ||
4999 | if (!can_convert (type, from, tf_none)) | |
5000 | { | |
5001 | if (!ctx->quiet) | |
6bdfada4 | 5002 | error_at (cp_expr_loc_or_loc (t, input_location), |
8bada5cd MS |
5003 | "conversion of %qT null pointer to %qT " |
5004 | "is not a constant expression", | |
5005 | from, type); | |
5006 | *non_constant_p = true; | |
5007 | return t; | |
5008 | } | |
5009 | } | |
5010 | } | |
5011 | else | |
5012 | { | |
5013 | /* This detects for example: | |
5014 | reinterpret_cast<void*>(sizeof 0) | |
5015 | */ | |
5016 | if (!ctx->quiet) | |
6bdfada4 | 5017 | error_at (cp_expr_loc_or_loc (t, input_location), |
8bada5cd | 5018 | "%<reinterpret_cast<%T>(%E)%> is not " |
64d6d399 | 5019 | "a constant expression", |
8bada5cd MS |
5020 | type, op); |
5021 | *non_constant_p = true; | |
5022 | return t; | |
5023 | } | |
2d76680f | 5024 | } |
7d75ea04 | 5025 | |
cda0a029 | 5026 | if (op == oldop && tcode != UNARY_PLUS_EXPR) |
2d76680f PC |
5027 | /* We didn't fold at the top so we could check for ptr-int |
5028 | conversion. */ | |
5029 | return fold (t); | |
7d75ea04 | 5030 | |
e4511ca2 JM |
5031 | /* Handle an array's bounds having been deduced after we built |
5032 | the wrapping expression. */ | |
5033 | if (same_type_ignoring_tlq_and_bounds_p (type, TREE_TYPE (op))) | |
5034 | r = op; | |
5035 | else if (tcode == UNARY_PLUS_EXPR) | |
cda0a029 JM |
5036 | r = fold_convert (TREE_TYPE (t), op); |
5037 | else | |
5038 | r = fold_build1 (tcode, type, op); | |
7d75ea04 | 5039 | |
2d76680f PC |
5040 | /* Conversion of an out-of-range value has implementation-defined |
5041 | behavior; the language considers it different from arithmetic | |
5042 | overflow, which is undefined. */ | |
5043 | if (TREE_OVERFLOW_P (r) && !TREE_OVERFLOW_P (op)) | |
5044 | TREE_OVERFLOW (r) = false; | |
5045 | } | |
5046 | break; | |
5047 | ||
5048 | case EMPTY_CLASS_EXPR: | |
5049 | /* This is good enough for a function argument that might not get | |
5050 | used, and they can't do anything with it, so just return it. */ | |
5051 | return t; | |
5052 | ||
60813a46 | 5053 | case STATEMENT_LIST: |
56632b27 JM |
5054 | new_ctx = *ctx; |
5055 | new_ctx.ctor = new_ctx.object = NULL_TREE; | |
2b3ab879 | 5056 | return cxx_eval_statement_list (&new_ctx, t, |
56632b27 | 5057 | non_constant_p, overflow_p, jump_target); |
60813a46 JM |
5058 | |
5059 | case BIND_EXPR: | |
5060 | return cxx_eval_constant_expression (ctx, BIND_EXPR_BODY (t), | |
92a596e8 | 5061 | lval, |
56632b27 JM |
5062 | non_constant_p, overflow_p, |
5063 | jump_target); | |
60813a46 | 5064 | |
2d76680f PC |
5065 | case PREINCREMENT_EXPR: |
5066 | case POSTINCREMENT_EXPR: | |
5067 | case PREDECREMENT_EXPR: | |
5068 | case POSTDECREMENT_EXPR: | |
2b3ab879 | 5069 | return cxx_eval_increment_expression (ctx, t, |
92a596e8 | 5070 | lval, non_constant_p, overflow_p); |
60813a46 JM |
5071 | |
5072 | case LAMBDA_EXPR: | |
2d76680f PC |
5073 | case NEW_EXPR: |
5074 | case VEC_NEW_EXPR: | |
5075 | case DELETE_EXPR: | |
5076 | case VEC_DELETE_EXPR: | |
5077 | case THROW_EXPR: | |
2d76680f PC |
5078 | case MODOP_EXPR: |
5079 | /* GCC internal stuff. */ | |
5080 | case VA_ARG_EXPR: | |
2d76680f PC |
5081 | case NON_DEPENDENT_EXPR: |
5082 | case BASELINK: | |
2d76680f | 5083 | case OFFSET_REF: |
2b3ab879 | 5084 | if (!ctx->quiet) |
6bdfada4 | 5085 | error_at (cp_expr_loc_or_loc (t, input_location), |
64d6d399 | 5086 | "expression %qE is not a constant expression", t); |
2d76680f PC |
5087 | *non_constant_p = true; |
5088 | break; | |
5089 | ||
bf8d8309 MP |
5090 | case OBJ_TYPE_REF: |
5091 | { | |
5092 | /* Virtual function call. Let the constexpr machinery figure out | |
5093 | the dynamic type. */ | |
5094 | int token = tree_to_shwi (OBJ_TYPE_REF_TOKEN (t)); | |
5095 | tree obj = OBJ_TYPE_REF_OBJECT (t); | |
5096 | obj = cxx_eval_constant_expression (ctx, obj, lval, non_constant_p, | |
5097 | overflow_p); | |
5098 | /* We expect something in the form of &x.D.2103.D.2094; get x. */ | |
6a3ebcc6 JJ |
5099 | if (TREE_CODE (obj) != ADDR_EXPR |
5100 | || !DECL_P (get_base_address (TREE_OPERAND (obj, 0)))) | |
bf8d8309 MP |
5101 | { |
5102 | if (!ctx->quiet) | |
5103 | error_at (cp_expr_loc_or_loc (t, input_location), | |
5104 | "expression %qE is not a constant expression", t); | |
5105 | *non_constant_p = true; | |
5106 | return t; | |
5107 | } | |
5108 | obj = TREE_OPERAND (obj, 0); | |
69deaf14 JJ |
5109 | while (TREE_CODE (obj) == COMPONENT_REF |
5110 | && DECL_FIELD_IS_BASE (TREE_OPERAND (obj, 1))) | |
bf8d8309 MP |
5111 | obj = TREE_OPERAND (obj, 0); |
5112 | tree objtype = TREE_TYPE (obj); | |
5113 | /* Find the function decl in the virtual functions list. TOKEN is | |
5114 | the DECL_VINDEX that says which function we're looking for. */ | |
5115 | tree virtuals = BINFO_VIRTUALS (TYPE_BINFO (objtype)); | |
582d2481 JJ |
5116 | if (TARGET_VTABLE_USES_DESCRIPTORS) |
5117 | token /= MAX (TARGET_VTABLE_USES_DESCRIPTORS, 1); | |
bf8d8309 MP |
5118 | r = TREE_VALUE (chain_index (token, virtuals)); |
5119 | break; | |
5120 | } | |
5121 | ||
3e605b20 | 5122 | case PLACEHOLDER_EXPR: |
89262ec6 JM |
5123 | /* Use of the value or address of the current object. */ |
5124 | if (tree ctor = lookup_placeholder (ctx, lval, TREE_TYPE (t))) | |
5125 | return cxx_eval_constant_expression (ctx, ctor, lval, | |
5126 | non_constant_p, overflow_p); | |
5127 | /* A placeholder without a referent. We can get here when | |
5128 | checking whether NSDMIs are noexcept, or in massage_init_elt; | |
5129 | just say it's non-constant for now. */ | |
5130 | gcc_assert (ctx->quiet); | |
5131 | *non_constant_p = true; | |
3e605b20 JM |
5132 | break; |
5133 | ||
06ec22b7 JM |
5134 | case EXIT_EXPR: |
5135 | { | |
5136 | tree cond = TREE_OPERAND (t, 0); | |
5137 | cond = cxx_eval_constant_expression (ctx, cond, /*lval*/false, | |
5138 | non_constant_p, overflow_p); | |
5139 | VERIFY_CONSTANT (cond); | |
5140 | if (integer_nonzerop (cond)) | |
5141 | *jump_target = t; | |
5142 | } | |
5143 | break; | |
5144 | ||
60813a46 | 5145 | case GOTO_EXPR: |
56632b27 | 5146 | *jump_target = TREE_OPERAND (t, 0); |
d49318d9 PC |
5147 | gcc_assert (breaks (jump_target) || continues (jump_target) |
5148 | /* Allow for jumping to a cdtor_label. */ | |
5149 | || returns (jump_target)); | |
56632b27 JM |
5150 | break; |
5151 | ||
60813a46 | 5152 | case LOOP_EXPR: |
43574e4f JJ |
5153 | case DO_STMT: |
5154 | case WHILE_STMT: | |
5155 | case FOR_STMT: | |
2b3ab879 | 5156 | cxx_eval_loop_expr (ctx, t, |
56632b27 JM |
5157 | non_constant_p, overflow_p, jump_target); |
5158 | break; | |
5159 | ||
60813a46 | 5160 | case SWITCH_EXPR: |
43574e4f | 5161 | case SWITCH_STMT: |
2b3ab879 | 5162 | cxx_eval_switch_expr (ctx, t, |
56632b27 | 5163 | non_constant_p, overflow_p, jump_target); |
60813a46 JM |
5164 | break; |
5165 | ||
971e17ff AS |
5166 | case REQUIRES_EXPR: |
5167 | /* It's possible to get a requires-expression in a constant | |
5168 | expression. For example: | |
5169 | ||
5170 | template<typename T> concept bool C() { | |
5171 | return requires (T t) { t; }; | |
5172 | } | |
5173 | ||
5174 | template<typename T> requires !C<T>() void f(T); | |
5175 | ||
5176 | Normalization leaves f with the associated constraint | |
5177 | '!requires (T t) { ... }' which is not transformed into | |
5178 | a constraint. */ | |
5179 | if (!processing_template_decl) | |
5180 | return evaluate_constraint_expression (t, NULL_TREE); | |
5181 | else | |
5182 | *non_constant_p = true; | |
5183 | return t; | |
5184 | ||
98e09245 | 5185 | case ANNOTATE_EXPR: |
98e09245 JJ |
5186 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), |
5187 | lval, | |
5188 | non_constant_p, overflow_p, | |
5189 | jump_target); | |
5190 | break; | |
5191 | ||
3664e317 JM |
5192 | case USING_STMT: |
5193 | r = void_node; | |
5194 | break; | |
5195 | ||
2d76680f | 5196 | default: |
c6e7c499 JM |
5197 | if (STATEMENT_CODE_P (TREE_CODE (t))) |
5198 | { | |
5199 | /* This function doesn't know how to deal with pre-genericize | |
5200 | statements; this can only happen with statement-expressions, | |
5201 | so for now just fail. */ | |
5202 | if (!ctx->quiet) | |
5203 | error_at (EXPR_LOCATION (t), | |
64d6d399 | 5204 | "statement is not a constant expression"); |
c6e7c499 JM |
5205 | } |
5206 | else | |
5207 | internal_error ("unexpected expression %qE of kind %s", t, | |
5208 | get_tree_code_name (TREE_CODE (t))); | |
2d76680f PC |
5209 | *non_constant_p = true; |
5210 | break; | |
5211 | } | |
5212 | ||
5213 | if (r == error_mark_node) | |
5214 | *non_constant_p = true; | |
5215 | ||
5216 | if (*non_constant_p) | |
5217 | return t; | |
5218 | else | |
5219 | return r; | |
5220 | } | |
5221 | ||
e079dced JM |
5222 | /* P0859: A function is needed for constant evaluation if it is a constexpr |
5223 | function that is named by an expression ([basic.def.odr]) that is | |
5224 | potentially constant evaluated. | |
5225 | ||
5226 | So we need to instantiate any constexpr functions mentioned by the | |
5227 | expression even if the definition isn't needed for evaluating the | |
5228 | expression. */ | |
5229 | ||
5230 | static tree | |
5231 | instantiate_cx_fn_r (tree *tp, int *walk_subtrees, void */*data*/) | |
5232 | { | |
5233 | if (TREE_CODE (*tp) == FUNCTION_DECL | |
5234 | && DECL_DECLARED_CONSTEXPR_P (*tp) | |
5235 | && !DECL_INITIAL (*tp) | |
4fdda3ce | 5236 | && !trivial_fn_p (*tp) |
e079dced JM |
5237 | && DECL_TEMPLOID_INSTANTIATION (*tp)) |
5238 | { | |
5239 | ++function_depth; | |
5240 | instantiate_decl (*tp, /*defer_ok*/false, /*expl_inst*/false); | |
5241 | --function_depth; | |
5242 | } | |
5243 | else if (TREE_CODE (*tp) == CALL_EXPR | |
5244 | || TREE_CODE (*tp) == AGGR_INIT_EXPR) | |
5245 | { | |
5246 | if (EXPR_HAS_LOCATION (*tp)) | |
5247 | input_location = EXPR_LOCATION (*tp); | |
5248 | } | |
5249 | ||
5250 | if (!EXPR_P (*tp)) | |
5251 | *walk_subtrees = 0; | |
5252 | ||
5253 | return NULL_TREE; | |
5254 | } | |
5255 | static void | |
5256 | instantiate_constexpr_fns (tree t) | |
5257 | { | |
5258 | location_t loc = input_location; | |
5259 | cp_walk_tree_without_duplicates (&t, instantiate_cx_fn_r, NULL); | |
5260 | input_location = loc; | |
5261 | } | |
5262 | ||
e4082611 | 5263 | /* ALLOW_NON_CONSTANT is false if T is required to be a constant expression. |
d4accef3 JM |
5264 | STRICT has the same sense as for constant_value_1: true if we only allow |
5265 | conforming C++ constant expressions, or false if we want a constant value | |
5266 | even if it doesn't conform. | |
13de99bc | 5267 | MANIFESTLY_CONST_EVAL is true if T is manifestly const-evaluated as |
e4082611 JJ |
5268 | per P0595 even when ALLOW_NON_CONSTANT is true. */ |
5269 | ||
2d76680f | 5270 | static tree |
3e605b20 | 5271 | cxx_eval_outermost_constant_expr (tree t, bool allow_non_constant, |
e4082611 | 5272 | bool strict = true, |
13de99bc | 5273 | bool manifestly_const_eval = false, |
e4082611 | 5274 | tree object = NULL_TREE) |
2d76680f | 5275 | { |
8108ea30 JM |
5276 | auto_timevar time (TV_CONSTEXPR); |
5277 | ||
2d76680f PC |
5278 | bool non_constant_p = false; |
5279 | bool overflow_p = false; | |
3e605b20 | 5280 | hash_map<tree,tree> map; |
a15ffa22 | 5281 | HOST_WIDE_INT constexpr_ctx_count = 0; |
39dce2b7 | 5282 | |
4b390698 | 5283 | constexpr_ctx ctx = { NULL, &map, NULL, NULL, NULL, NULL, |
a15ffa22 | 5284 | &constexpr_ctx_count, allow_non_constant, strict, |
13de99bc | 5285 | manifestly_const_eval || !allow_non_constant }; |
39dce2b7 | 5286 | |
3e605b20 | 5287 | tree type = initialized_type (t); |
3e605b20 | 5288 | tree r = t; |
4d0c18c6 JM |
5289 | if (VOID_TYPE_P (type)) |
5290 | return t; | |
3e605b20 JM |
5291 | if (AGGREGATE_TYPE_P (type) || VECTOR_TYPE_P (type)) |
5292 | { | |
5293 | /* In C++14 an NSDMI can participate in aggregate initialization, | |
5294 | and can refer to the address of the object being initialized, so | |
5295 | we need to pass in the relevant VAR_DECL if we want to do the | |
5296 | evaluation in a single pass. The evaluation will dynamically | |
5297 | update ctx.values for the VAR_DECL. We use the same strategy | |
5298 | for C++11 constexpr constructors that refer to the object being | |
5299 | initialized. */ | |
5300 | ctx.ctor = build_constructor (type, NULL); | |
e8c48716 | 5301 | CONSTRUCTOR_NO_CLEARING (ctx.ctor) = true; |
60813a46 JM |
5302 | if (!object) |
5303 | { | |
5304 | if (TREE_CODE (t) == TARGET_EXPR) | |
5305 | object = TARGET_EXPR_SLOT (t); | |
5306 | else if (TREE_CODE (t) == AGGR_INIT_EXPR) | |
5307 | object = AGGR_INIT_EXPR_SLOT (t); | |
5308 | } | |
3e605b20 JM |
5309 | ctx.object = object; |
5310 | if (object) | |
5311 | gcc_assert (same_type_ignoring_top_level_qualifiers_p | |
5312 | (type, TREE_TYPE (object))); | |
5313 | if (object && DECL_P (object)) | |
5314 | map.put (object, ctx.ctor); | |
5315 | if (TREE_CODE (r) == TARGET_EXPR) | |
5316 | /* Avoid creating another CONSTRUCTOR when we expand the | |
5317 | TARGET_EXPR. */ | |
5318 | r = TARGET_EXPR_INITIAL (r); | |
5319 | } | |
5320 | ||
e079dced | 5321 | instantiate_constexpr_fns (r); |
2b3ab879 | 5322 | r = cxx_eval_constant_expression (&ctx, r, |
5a804683 | 5323 | false, &non_constant_p, &overflow_p); |
2d76680f PC |
5324 | |
5325 | verify_constant (r, allow_non_constant, &non_constant_p, &overflow_p); | |
5326 | ||
023d89c7 JM |
5327 | /* Mutable logic is a bit tricky: we want to allow initialization of |
5328 | constexpr variables with mutable members, but we can't copy those | |
5329 | members to another constexpr variable. */ | |
5330 | if (TREE_CODE (r) == CONSTRUCTOR | |
5331 | && CONSTRUCTOR_MUTABLE_POISON (r)) | |
2d76680f | 5332 | { |
2d76680f | 5333 | if (!allow_non_constant) |
023d89c7 JM |
5334 | error ("%qE is not a constant expression because it refers to " |
5335 | "mutable subobjects of %qT", t, type); | |
2d76680f PC |
5336 | non_constant_p = true; |
5337 | } | |
5338 | ||
f64e0c02 | 5339 | if (TREE_CODE (r) == CONSTRUCTOR |
e8c48716 | 5340 | && CONSTRUCTOR_NO_CLEARING (r)) |
f64e0c02 JM |
5341 | { |
5342 | if (!allow_non_constant) | |
5343 | error ("%qE is not a constant expression because it refers to " | |
5344 | "an incompletely initialized variable", t); | |
5345 | TREE_CONSTANT (r) = false; | |
5346 | non_constant_p = true; | |
5347 | } | |
5348 | ||
2d76680f PC |
5349 | /* Technically we should check this for all subexpressions, but that |
5350 | runs into problems with our internal representation of pointer | |
5351 | subtraction and the 5.19 rules are still in flux. */ | |
5352 | if (CONVERT_EXPR_CODE_P (TREE_CODE (r)) | |
5353 | && ARITHMETIC_TYPE_P (TREE_TYPE (r)) | |
5354 | && TREE_CODE (TREE_OPERAND (r, 0)) == ADDR_EXPR) | |
5355 | { | |
5356 | if (!allow_non_constant) | |
5357 | error ("conversion from pointer type %qT " | |
64d6d399 | 5358 | "to arithmetic type %qT in a constant expression", |
2d76680f PC |
5359 | TREE_TYPE (TREE_OPERAND (r, 0)), TREE_TYPE (r)); |
5360 | non_constant_p = true; | |
5361 | } | |
5362 | ||
5363 | if (!non_constant_p && overflow_p) | |
5364 | non_constant_p = true; | |
5365 | ||
56cfb596 PP |
5366 | /* Unshare the result unless it's a CONSTRUCTOR in which case it's already |
5367 | unshared. */ | |
5368 | bool should_unshare = true; | |
5369 | if (r == t || TREE_CODE (r) == CONSTRUCTOR) | |
5370 | should_unshare = false; | |
5371 | ||
2d76680f PC |
5372 | if (non_constant_p && !allow_non_constant) |
5373 | return error_mark_node; | |
5374 | else if (non_constant_p && TREE_CONSTANT (r)) | |
5375 | { | |
e4082611 JJ |
5376 | /* If __builtin_is_constant_evaluated () was evaluated to true |
5377 | and the result is not a valid constant expression, we need to | |
5378 | punt. */ | |
13de99bc | 5379 | if (manifestly_const_eval) |
e4082611 JJ |
5380 | return cxx_eval_outermost_constant_expr (t, true, strict, |
5381 | false, object); | |
eddd715c JM |
5382 | /* This isn't actually constant, so unset TREE_CONSTANT. |
5383 | Don't clear TREE_CONSTANT on ADDR_EXPR, as the middle-end requires | |
5384 | it to be set if it is invariant address, even when it is not | |
5385 | a valid C++ constant expression. Wrap it with a NOP_EXPR | |
5386 | instead. */ | |
5387 | if (EXPR_P (r) && TREE_CODE (r) != ADDR_EXPR) | |
2d76680f PC |
5388 | r = copy_node (r); |
5389 | else if (TREE_CODE (r) == CONSTRUCTOR) | |
5390 | r = build1 (VIEW_CONVERT_EXPR, TREE_TYPE (r), r); | |
5391 | else | |
5392 | r = build_nop (TREE_TYPE (r), r); | |
5393 | TREE_CONSTANT (r) = false; | |
5394 | } | |
5dab8b11 | 5395 | else if (non_constant_p) |
2d76680f PC |
5396 | return t; |
5397 | ||
56cfb596 PP |
5398 | if (should_unshare) |
5399 | r = unshare_expr (r); | |
5400 | ||
2d76680f PC |
5401 | if (TREE_CODE (r) == CONSTRUCTOR && CLASS_TYPE_P (TREE_TYPE (r))) |
5402 | { | |
5dab8b11 | 5403 | r = adjust_temp_type (type, r); |
2d76680f PC |
5404 | if (TREE_CODE (t) == TARGET_EXPR |
5405 | && TARGET_EXPR_INITIAL (t) == r) | |
5406 | return t; | |
5dab8b11 | 5407 | else if (TREE_CODE (t) != CONSTRUCTOR) |
2d76680f PC |
5408 | { |
5409 | r = get_target_expr (r); | |
5410 | TREE_CONSTANT (r) = true; | |
2d76680f PC |
5411 | } |
5412 | } | |
5dab8b11 JM |
5413 | |
5414 | return r; | |
2d76680f PC |
5415 | } |
5416 | ||
5417 | /* Returns true if T is a valid subexpression of a constant expression, | |
5418 | even if it isn't itself a constant expression. */ | |
5419 | ||
5420 | bool | |
5421 | is_sub_constant_expr (tree t) | |
5422 | { | |
5423 | bool non_constant_p = false; | |
5424 | bool overflow_p = false; | |
3e605b20 | 5425 | hash_map <tree, tree> map; |
a15ffa22 | 5426 | HOST_WIDE_INT constexpr_ops_count = 0; |
39dce2b7 | 5427 | |
e4082611 | 5428 | constexpr_ctx ctx |
a15ffa22 JJ |
5429 | = { NULL, &map, NULL, NULL, NULL, NULL, &constexpr_ops_count, |
5430 | true, true, false }; | |
39dce2b7 | 5431 | |
e079dced | 5432 | instantiate_constexpr_fns (t); |
2b3ab879 | 5433 | cxx_eval_constant_expression (&ctx, t, false, &non_constant_p, |
5a804683 | 5434 | &overflow_p); |
2d76680f PC |
5435 | return !non_constant_p && !overflow_p; |
5436 | } | |
5437 | ||
5438 | /* If T represents a constant expression returns its reduced value. | |
5439 | Otherwise return error_mark_node. If T is dependent, then | |
5440 | return NULL. */ | |
5441 | ||
5442 | tree | |
3e605b20 | 5443 | cxx_constant_value (tree t, tree decl) |
2d76680f | 5444 | { |
e4082611 | 5445 | return cxx_eval_outermost_constant_expr (t, false, true, true, decl); |
2d76680f PC |
5446 | } |
5447 | ||
cda0a029 JM |
5448 | /* Helper routine for fold_simple function. Either return simplified |
5449 | expression T, otherwise NULL_TREE. | |
5450 | In contrast to cp_fully_fold, and to maybe_constant_value, we try to fold | |
5451 | even if we are within template-declaration. So be careful on call, as in | |
5452 | such case types can be undefined. */ | |
5453 | ||
5454 | static tree | |
5455 | fold_simple_1 (tree t) | |
5456 | { | |
5457 | tree op1; | |
5458 | enum tree_code code = TREE_CODE (t); | |
5459 | ||
5460 | switch (code) | |
5461 | { | |
5462 | case INTEGER_CST: | |
5463 | case REAL_CST: | |
5464 | case VECTOR_CST: | |
5465 | case FIXED_CST: | |
5466 | case COMPLEX_CST: | |
5467 | return t; | |
5468 | ||
5469 | case SIZEOF_EXPR: | |
5470 | return fold_sizeof_expr (t); | |
5471 | ||
5472 | case ABS_EXPR: | |
e28fadbc | 5473 | case ABSU_EXPR: |
cda0a029 JM |
5474 | case CONJ_EXPR: |
5475 | case REALPART_EXPR: | |
5476 | case IMAGPART_EXPR: | |
5477 | case NEGATE_EXPR: | |
5478 | case BIT_NOT_EXPR: | |
5479 | case TRUTH_NOT_EXPR: | |
5480 | case NOP_EXPR: | |
5481 | case VIEW_CONVERT_EXPR: | |
5482 | case CONVERT_EXPR: | |
5483 | case FLOAT_EXPR: | |
5484 | case FIX_TRUNC_EXPR: | |
5485 | case FIXED_CONVERT_EXPR: | |
5486 | case ADDR_SPACE_CONVERT_EXPR: | |
5487 | ||
5488 | op1 = TREE_OPERAND (t, 0); | |
5489 | ||
5490 | t = const_unop (code, TREE_TYPE (t), op1); | |
5491 | if (!t) | |
5492 | return NULL_TREE; | |
5493 | ||
5494 | if (CONVERT_EXPR_CODE_P (code) | |
5495 | && TREE_OVERFLOW_P (t) && !TREE_OVERFLOW_P (op1)) | |
5496 | TREE_OVERFLOW (t) = false; | |
5497 | return t; | |
5498 | ||
5499 | default: | |
5500 | return NULL_TREE; | |
5501 | } | |
5502 | } | |
5503 | ||
5504 | /* If T is a simple constant expression, returns its simplified value. | |
dba99244 | 5505 | Otherwise returns T. In contrast to maybe_constant_value we |
cda0a029 JM |
5506 | simplify only few operations on constant-expressions, and we don't |
5507 | try to simplify constexpressions. */ | |
5508 | ||
5509 | tree | |
5510 | fold_simple (tree t) | |
5511 | { | |
cda0a029 JM |
5512 | if (processing_template_decl) |
5513 | return t; | |
5514 | ||
dba99244 MP |
5515 | tree r = fold_simple_1 (t); |
5516 | if (r) | |
5517 | return r; | |
cda0a029 | 5518 | |
dba99244 | 5519 | return t; |
cda0a029 JM |
5520 | } |
5521 | ||
2d76680f PC |
5522 | /* If T is a constant expression, returns its reduced value. |
5523 | Otherwise, if T does not have TREE_CONSTANT set, returns T. | |
13de99bc JJ |
5524 | Otherwise, returns a version of T without TREE_CONSTANT. |
5525 | MANIFESTLY_CONST_EVAL is true if T is manifestly const-evaluated | |
5526 | as per P0595. */ | |
2d76680f | 5527 | |
8a87daca JM |
5528 | static GTY((deletable)) hash_map<tree, tree> *cv_cache; |
5529 | ||
5530 | tree | |
13de99bc | 5531 | maybe_constant_value (tree t, tree decl, bool manifestly_const_eval) |
2d76680f PC |
5532 | { |
5533 | tree r; | |
5534 | ||
a0ab7ccd | 5535 | if (!is_nondependent_constant_expression (t)) |
2d76680f PC |
5536 | { |
5537 | if (TREE_OVERFLOW_P (t)) | |
5538 | { | |
5539 | t = build_nop (TREE_TYPE (t), t); | |
5540 | TREE_CONSTANT (t) = false; | |
5541 | } | |
5542 | return t; | |
5543 | } | |
8a87daca JM |
5544 | else if (CONSTANT_CLASS_P (t)) |
5545 | /* No caching or evaluation needed. */ | |
5546 | return t; | |
5547 | ||
13de99bc JJ |
5548 | if (manifestly_const_eval) |
5549 | return cxx_eval_outermost_constant_expr (t, true, true, true, decl); | |
5550 | ||
8a87daca JM |
5551 | if (cv_cache == NULL) |
5552 | cv_cache = hash_map<tree, tree>::create_ggc (101); | |
5553 | if (tree *cached = cv_cache->get (t)) | |
5554 | return *cached; | |
2d76680f | 5555 | |
e4082611 | 5556 | r = cxx_eval_outermost_constant_expr (t, true, true, false, decl); |
595278be MM |
5557 | gcc_checking_assert (r == t |
5558 | || CONVERT_EXPR_P (t) | |
5559 | || TREE_CODE (t) == VIEW_CONVERT_EXPR | |
5560 | || (TREE_CONSTANT (t) && !TREE_CONSTANT (r)) | |
5561 | || !cp_tree_equal (r, t)); | |
8a87daca | 5562 | cv_cache->put (t, r); |
2d76680f PC |
5563 | return r; |
5564 | } | |
5565 | ||
7a7ac32a PP |
5566 | /* Dispose of the whole CV_CACHE. */ |
5567 | ||
5568 | static void | |
5569 | clear_cv_cache (void) | |
5570 | { | |
5571 | if (cv_cache != NULL) | |
5572 | cv_cache->empty (); | |
5573 | } | |
5574 | ||
eba9e839 | 5575 | /* Dispose of the whole CV_CACHE and FOLD_CACHE. */ |
1e297006 MP |
5576 | |
5577 | void | |
eba9e839 | 5578 | clear_cv_and_fold_caches (void) |
1e297006 | 5579 | { |
7a7ac32a | 5580 | clear_cv_cache (); |
eba9e839 | 5581 | clear_fold_cache (); |
1e297006 MP |
5582 | } |
5583 | ||
234bef96 PC |
5584 | /* Like maybe_constant_value but first fully instantiate the argument. |
5585 | ||
5586 | Note: this is equivalent to instantiate_non_dependent_expr_sfinae | |
e56f6629 JM |
5587 | (t, complain) followed by maybe_constant_value but is more efficient, |
5588 | because it calls instantiation_dependent_expression_p and | |
5589 | potential_constant_expression at most once. | |
4cd3e7df | 5590 | The manifestly_const_eval argument is passed to maybe_constant_value. |
e56f6629 JM |
5591 | |
5592 | Callers should generally pass their active complain, or if they are in a | |
5593 | non-template, diagnosing context, they can use the default of | |
5594 | tf_warning_or_error. Callers that might be within a template context, don't | |
5595 | have a complain parameter, and aren't going to remember the result for long | |
5596 | (e.g. null_ptr_cst_p), can pass tf_none and deal with error_mark_node | |
5597 | appropriately. */ | |
234bef96 PC |
5598 | |
5599 | tree | |
e56f6629 | 5600 | fold_non_dependent_expr (tree t, |
4cd3e7df JJ |
5601 | tsubst_flags_t complain /* = tf_warning_or_error */, |
5602 | bool manifestly_const_eval /* = false */) | |
234bef96 PC |
5603 | { |
5604 | if (t == NULL_TREE) | |
5605 | return NULL_TREE; | |
5606 | ||
5607 | /* If we're in a template, but T isn't value dependent, simplify | |
5608 | it. We're supposed to treat: | |
5609 | ||
5610 | template <typename T> void f(T[1 + 1]); | |
5611 | template <typename T> void f(T[2]); | |
5612 | ||
5613 | as two declarations of the same function, for example. */ | |
5614 | if (processing_template_decl) | |
5615 | { | |
a0ab7ccd | 5616 | if (is_nondependent_constant_expression (t)) |
234bef96 | 5617 | { |
1b5695e6 | 5618 | processing_template_decl_sentinel s; |
e56f6629 | 5619 | t = instantiate_non_dependent_expr_internal (t, complain); |
234bef96 PC |
5620 | |
5621 | if (type_unknown_p (t) | |
5622 | || BRACE_ENCLOSED_INITIALIZER_P (t)) | |
5623 | { | |
5624 | if (TREE_OVERFLOW_P (t)) | |
5625 | { | |
5626 | t = build_nop (TREE_TYPE (t), t); | |
5627 | TREE_CONSTANT (t) = false; | |
5628 | } | |
5629 | return t; | |
5630 | } | |
5631 | ||
4cd3e7df JJ |
5632 | tree r = cxx_eval_outermost_constant_expr (t, true, true, |
5633 | manifestly_const_eval, | |
e4082611 | 5634 | NULL_TREE); |
234bef96 | 5635 | /* cp_tree_equal looks through NOPs, so allow them. */ |
595278be MM |
5636 | gcc_checking_assert (r == t |
5637 | || CONVERT_EXPR_P (t) | |
5638 | || TREE_CODE (t) == VIEW_CONVERT_EXPR | |
5639 | || (TREE_CONSTANT (t) && !TREE_CONSTANT (r)) | |
5640 | || !cp_tree_equal (r, t)); | |
234bef96 PC |
5641 | return r; |
5642 | } | |
5643 | else if (TREE_OVERFLOW_P (t)) | |
5644 | { | |
5645 | t = build_nop (TREE_TYPE (t), t); | |
5646 | TREE_CONSTANT (t) = false; | |
5647 | } | |
5648 | return t; | |
5649 | } | |
5650 | ||
4cd3e7df | 5651 | return maybe_constant_value (t, NULL_TREE, manifestly_const_eval); |
234bef96 PC |
5652 | } |
5653 | ||
2d76680f | 5654 | /* Like maybe_constant_value, but returns a CONSTRUCTOR directly, rather |
e4082611 JJ |
5655 | than wrapped in a TARGET_EXPR. |
5656 | ALLOW_NON_CONSTANT is false if T is required to be a constant expression. | |
13de99bc | 5657 | MANIFESTLY_CONST_EVAL is true if T is manifestly const-evaluated as |
e4082611 | 5658 | per P0595 even when ALLOW_NON_CONSTANT is true. */ |
2d76680f | 5659 | |
118cd6ba | 5660 | static tree |
e4082611 | 5661 | maybe_constant_init_1 (tree t, tree decl, bool allow_non_constant, |
13de99bc | 5662 | bool manifestly_const_eval) |
2d76680f | 5663 | { |
cda0a029 JM |
5664 | if (!t) |
5665 | return t; | |
2d76680f PC |
5666 | if (TREE_CODE (t) == EXPR_STMT) |
5667 | t = TREE_OPERAND (t, 0); | |
5668 | if (TREE_CODE (t) == CONVERT_EXPR | |
5669 | && VOID_TYPE_P (TREE_TYPE (t))) | |
5670 | t = TREE_OPERAND (t, 0); | |
60813a46 JM |
5671 | if (TREE_CODE (t) == INIT_EXPR) |
5672 | t = TREE_OPERAND (t, 1); | |
f64e0c02 JM |
5673 | if (TREE_CODE (t) == TARGET_EXPR) |
5674 | t = TARGET_EXPR_INITIAL (t); | |
a0ab7ccd | 5675 | if (!is_nondependent_static_init_expression (t)) |
69eb4fde | 5676 | /* Don't try to evaluate it. */; |
118cd6ba | 5677 | else if (CONSTANT_CLASS_P (t) && allow_non_constant) |
8a87daca | 5678 | /* No evaluation needed. */; |
69eb4fde | 5679 | else |
e4082611 | 5680 | t = cxx_eval_outermost_constant_expr (t, allow_non_constant, |
38295573 | 5681 | /*strict*/false, |
13de99bc | 5682 | manifestly_const_eval, decl); |
2d76680f PC |
5683 | if (TREE_CODE (t) == TARGET_EXPR) |
5684 | { | |
5685 | tree init = TARGET_EXPR_INITIAL (t); | |
5686 | if (TREE_CODE (init) == CONSTRUCTOR) | |
5687 | t = init; | |
5688 | } | |
5689 | return t; | |
5690 | } | |
5691 | ||
118cd6ba MP |
5692 | /* Wrapper for maybe_constant_init_1 which permits non constants. */ |
5693 | ||
5694 | tree | |
13de99bc | 5695 | maybe_constant_init (tree t, tree decl, bool manifestly_const_eval) |
118cd6ba | 5696 | { |
13de99bc | 5697 | return maybe_constant_init_1 (t, decl, true, manifestly_const_eval); |
118cd6ba MP |
5698 | } |
5699 | ||
5700 | /* Wrapper for maybe_constant_init_1 which does not permit non constants. */ | |
5701 | ||
5702 | tree | |
5703 | cxx_constant_init (tree t, tree decl) | |
5704 | { | |
e4082611 | 5705 | return maybe_constant_init_1 (t, decl, false, true); |
118cd6ba MP |
5706 | } |
5707 | ||
2d76680f PC |
5708 | #if 0 |
5709 | /* FIXME see ADDR_EXPR section in potential_constant_expression_1. */ | |
5710 | /* Return true if the object referred to by REF has automatic or thread | |
5711 | local storage. */ | |
5712 | ||
5713 | enum { ck_ok, ck_bad, ck_unknown }; | |
5714 | static int | |
5715 | check_automatic_or_tls (tree ref) | |
5716 | { | |
ef4bddc2 | 5717 | machine_mode mode; |
f37fac2b | 5718 | poly_int64 bitsize, bitpos; |
2d76680f PC |
5719 | tree offset; |
5720 | int volatilep = 0, unsignedp = 0; | |
5721 | tree decl = get_inner_reference (ref, &bitsize, &bitpos, &offset, | |
5722 | &mode, &unsignedp, &volatilep, false); | |
5723 | duration_kind dk; | |
5724 | ||
5725 | /* If there isn't a decl in the middle, we don't know the linkage here, | |
5726 | and this isn't a constant expression anyway. */ | |
5727 | if (!DECL_P (decl)) | |
5728 | return ck_unknown; | |
5729 | dk = decl_storage_duration (decl); | |
5730 | return (dk == dk_auto || dk == dk_thread) ? ck_bad : ck_ok; | |
5731 | } | |
5732 | #endif | |
5733 | ||
5734 | /* Return true if T denotes a potentially constant expression. Issue | |
5735 | diagnostic as appropriate under control of FLAGS. If WANT_RVAL is true, | |
a0ab7ccd JM |
5736 | an lvalue-rvalue conversion is implied. If NOW is true, we want to |
5737 | consider the expression in the current context, independent of constexpr | |
5738 | substitution. | |
2d76680f PC |
5739 | |
5740 | C++0x [expr.const] used to say | |
5741 | ||
5742 | 6 An expression is a potential constant expression if it is | |
5743 | a constant expression where all occurrences of function | |
5744 | parameters are replaced by arbitrary constant expressions | |
5745 | of the appropriate type. | |
5746 | ||
5747 | 2 A conditional expression is a constant expression unless it | |
5748 | involves one of the following as a potentially evaluated | |
5749 | subexpression (3.2), but subexpressions of logical AND (5.14), | |
5750 | logical OR (5.15), and conditional (5.16) operations that are | |
5751 | not evaluated are not considered. */ | |
5752 | ||
5753 | static bool | |
a0ab7ccd | 5754 | potential_constant_expression_1 (tree t, bool want_rval, bool strict, bool now, |
3075affd | 5755 | tsubst_flags_t flags, tree *jump_target) |
2d76680f | 5756 | { |
a0ab7ccd | 5757 | #define RECUR(T,RV) \ |
3075affd | 5758 | potential_constant_expression_1 ((T), (RV), strict, now, flags, jump_target) |
a0ab7ccd | 5759 | |
2d76680f PC |
5760 | enum { any = false, rval = true }; |
5761 | int i; | |
5762 | tree tmp; | |
5763 | ||
5764 | if (t == error_mark_node) | |
5765 | return false; | |
5766 | if (t == NULL_TREE) | |
5767 | return true; | |
6bdfada4 | 5768 | location_t loc = cp_expr_loc_or_loc (t, input_location); |
3075affd JM |
5769 | |
5770 | if (*jump_target) | |
5771 | /* If we are jumping, ignore everything. This is simpler than the | |
5772 | cxx_eval_constant_expression handling because we only need to be | |
5773 | conservatively correct, and we don't necessarily have a constant value | |
5774 | available, so we don't bother with switch tracking. */ | |
5775 | return true; | |
5776 | ||
3c393a2c | 5777 | if (TREE_THIS_VOLATILE (t) && want_rval) |
2d76680f PC |
5778 | { |
5779 | if (flags & tf_error) | |
3c393a2c MP |
5780 | error_at (loc, "lvalue-to-rvalue conversion of a volatile lvalue " |
5781 | "%qE with type %qT", t, TREE_TYPE (t)); | |
2d76680f PC |
5782 | return false; |
5783 | } | |
5784 | if (CONSTANT_CLASS_P (t)) | |
5785 | return true; | |
7dc2b4a2 JM |
5786 | if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_TYPED) |
5787 | && TREE_TYPE (t) == error_mark_node) | |
5788 | return false; | |
2d76680f PC |
5789 | |
5790 | switch (TREE_CODE (t)) | |
5791 | { | |
5792 | case FUNCTION_DECL: | |
5793 | case BASELINK: | |
5794 | case TEMPLATE_DECL: | |
5795 | case OVERLOAD: | |
5796 | case TEMPLATE_ID_EXPR: | |
5797 | case LABEL_DECL: | |
5798 | case LABEL_EXPR: | |
60813a46 | 5799 | case CASE_LABEL_EXPR: |
2d76680f PC |
5800 | case CONST_DECL: |
5801 | case SIZEOF_EXPR: | |
5802 | case ALIGNOF_EXPR: | |
5803 | case OFFSETOF_EXPR: | |
5804 | case NOEXCEPT_EXPR: | |
5805 | case TEMPLATE_PARM_INDEX: | |
5806 | case TRAIT_EXPR: | |
5807 | case IDENTIFIER_NODE: | |
5808 | case USERDEF_LITERAL: | |
5809 | /* We can see a FIELD_DECL in a pointer-to-member expression. */ | |
5810 | case FIELD_DECL: | |
cda0a029 | 5811 | case RESULT_DECL: |
2d76680f | 5812 | case USING_DECL: |
60813a46 | 5813 | case USING_STMT: |
3e605b20 | 5814 | case PLACEHOLDER_EXPR: |
971e17ff | 5815 | case REQUIRES_EXPR: |
98e5a19a | 5816 | case STATIC_ASSERT: |
96a95ac1 | 5817 | case DEBUG_BEGIN_STMT: |
2d76680f PC |
5818 | return true; |
5819 | ||
3075affd JM |
5820 | case RETURN_EXPR: |
5821 | if (!RECUR (TREE_OPERAND (t, 0), any)) | |
5822 | return false; | |
5823 | /* FALLTHROUGH */ | |
5824 | ||
5825 | case BREAK_STMT: | |
5826 | case CONTINUE_STMT: | |
5827 | *jump_target = t; | |
5828 | return true; | |
5829 | ||
a0ab7ccd JM |
5830 | case PARM_DECL: |
5831 | if (now) | |
5832 | { | |
5833 | if (flags & tf_error) | |
5834 | error ("%qE is not a constant expression", t); | |
5835 | return false; | |
5836 | } | |
5837 | return true; | |
5838 | ||
2d76680f PC |
5839 | case AGGR_INIT_EXPR: |
5840 | case CALL_EXPR: | |
5841 | /* -- an invocation of a function other than a constexpr function | |
5842 | or a constexpr constructor. */ | |
5843 | { | |
5844 | tree fun = get_function_named_in_call (t); | |
5845 | const int nargs = call_expr_nargs (t); | |
5846 | i = 0; | |
5847 | ||
60813a46 JM |
5848 | if (fun == NULL_TREE) |
5849 | { | |
44a845ca MS |
5850 | /* Reset to allow the function to continue past the end |
5851 | of the block below. Otherwise return early. */ | |
5852 | bool bail = true; | |
5853 | ||
35228ac7 JJ |
5854 | if (TREE_CODE (t) == CALL_EXPR |
5855 | && CALL_EXPR_FN (t) == NULL_TREE) | |
5856 | switch (CALL_EXPR_IFN (t)) | |
5857 | { | |
5858 | /* These should be ignored, they are optimized away from | |
5859 | constexpr functions. */ | |
5860 | case IFN_UBSAN_NULL: | |
5861 | case IFN_UBSAN_BOUNDS: | |
5862 | case IFN_UBSAN_VPTR: | |
81fea426 | 5863 | case IFN_FALLTHROUGH: |
35228ac7 | 5864 | return true; |
44a845ca MS |
5865 | |
5866 | case IFN_ADD_OVERFLOW: | |
5867 | case IFN_SUB_OVERFLOW: | |
5868 | case IFN_MUL_OVERFLOW: | |
e16f1cc7 | 5869 | case IFN_LAUNDER: |
d8fcab68 | 5870 | case IFN_VEC_CONVERT: |
44a845ca | 5871 | bail = false; |
d8fcab68 | 5872 | break; |
44a845ca | 5873 | |
35228ac7 JJ |
5874 | default: |
5875 | break; | |
5876 | } | |
44a845ca MS |
5877 | |
5878 | if (bail) | |
5879 | { | |
5880 | /* fold_call_expr can't do anything with IFN calls. */ | |
5881 | if (flags & tf_error) | |
e40b6fc7 | 5882 | error_at (loc, "call to internal function %qE", t); |
44a845ca MS |
5883 | return false; |
5884 | } | |
60813a46 | 5885 | } |
44a845ca MS |
5886 | |
5887 | if (fun && is_overloaded_fn (fun)) | |
2d76680f PC |
5888 | { |
5889 | if (TREE_CODE (fun) == FUNCTION_DECL) | |
5890 | { | |
5891 | if (builtin_valid_in_constant_expr_p (fun)) | |
5892 | return true; | |
5893 | if (!DECL_DECLARED_CONSTEXPR_P (fun) | |
5894 | /* Allow any built-in function; if the expansion | |
5895 | isn't constant, we'll deal with that then. */ | |
3d78e008 | 5896 | && !fndecl_built_in_p (fun)) |
2d76680f PC |
5897 | { |
5898 | if (flags & tf_error) | |
5899 | { | |
84fa214d | 5900 | error_at (loc, "call to non-%<constexpr%> function %qD", |
e40b6fc7 | 5901 | fun); |
2d76680f PC |
5902 | explain_invalid_constexpr_fn (fun); |
5903 | } | |
5904 | return false; | |
5905 | } | |
5906 | /* A call to a non-static member function takes the address | |
5907 | of the object as the first argument. But in a constant | |
5908 | expression the address will be folded away, so look | |
5909 | through it now. */ | |
5910 | if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fun) | |
5911 | && !DECL_CONSTRUCTOR_P (fun)) | |
5912 | { | |
5913 | tree x = get_nth_callarg (t, 0); | |
5914 | if (is_this_parameter (x)) | |
3e605b20 | 5915 | return true; |
a0ab7ccd JM |
5916 | /* Don't require an immediately constant value, as |
5917 | constexpr substitution might not use the value. */ | |
5918 | bool sub_now = false; | |
5919 | if (!potential_constant_expression_1 (x, rval, strict, | |
3075affd JM |
5920 | sub_now, flags, |
5921 | jump_target)) | |
2d76680f PC |
5922 | return false; |
5923 | i = 1; | |
5924 | } | |
5925 | } | |
5926 | else | |
5927 | { | |
69eb4fde | 5928 | if (!RECUR (fun, true)) |
2d76680f PC |
5929 | return false; |
5930 | fun = get_first_fn (fun); | |
5931 | } | |
5932 | /* Skip initial arguments to base constructors. */ | |
5933 | if (DECL_BASE_CONSTRUCTOR_P (fun)) | |
5934 | i = num_artificial_parms_for (fun); | |
5935 | fun = DECL_ORIGIN (fun); | |
5936 | } | |
44a845ca | 5937 | else if (fun) |
2d76680f | 5938 | { |
69eb4fde | 5939 | if (RECUR (fun, rval)) |
2d76680f PC |
5940 | /* Might end up being a constant function pointer. */; |
5941 | else | |
5942 | return false; | |
5943 | } | |
5944 | for (; i < nargs; ++i) | |
5945 | { | |
5946 | tree x = get_nth_callarg (t, i); | |
c3c29ba5 JM |
5947 | /* In a template, reference arguments haven't been converted to |
5948 | REFERENCE_TYPE and we might not even know if the parameter | |
5949 | is a reference, so accept lvalue constants too. */ | |
5950 | bool rv = processing_template_decl ? any : rval; | |
a0ab7ccd JM |
5951 | /* Don't require an immediately constant value, as constexpr |
5952 | substitution might not use the value of the argument. */ | |
5953 | bool sub_now = false; | |
5954 | if (!potential_constant_expression_1 (x, rv, strict, | |
3075affd | 5955 | sub_now, flags, jump_target)) |
2d76680f PC |
5956 | return false; |
5957 | } | |
5958 | return true; | |
5959 | } | |
5960 | ||
5961 | case NON_LVALUE_EXPR: | |
5962 | /* -- an lvalue-to-rvalue conversion (4.1) unless it is applied to | |
5963 | -- an lvalue of integral type that refers to a non-volatile | |
5964 | const variable or static data member initialized with | |
5965 | constant expressions, or | |
5966 | ||
5967 | -- an lvalue of literal type that refers to non-volatile | |
5968 | object defined with constexpr, or that refers to a | |
5969 | sub-object of such an object; */ | |
69eb4fde | 5970 | return RECUR (TREE_OPERAND (t, 0), rval); |
2d76680f PC |
5971 | |
5972 | case VAR_DECL: | |
70f40fea | 5973 | if (DECL_HAS_VALUE_EXPR_P (t)) |
c1051bf7 | 5974 | { |
68ad1bf7 | 5975 | if (now && is_normal_capture_proxy (t)) |
c1051bf7 JM |
5976 | { |
5977 | /* -- in a lambda-expression, a reference to this or to a | |
5978 | variable with automatic storage duration defined outside that | |
5979 | lambda-expression, where the reference would be an | |
5980 | odr-use. */ | |
5981 | if (flags & tf_error) | |
5982 | { | |
5983 | tree cap = DECL_CAPTURED_VARIABLE (t); | |
5984 | error ("lambda capture of %qE is not a constant expression", | |
5985 | cap); | |
5986 | if (!want_rval && decl_constant_var_p (cap)) | |
5987 | inform (input_location, "because it is used as a glvalue"); | |
5988 | } | |
5989 | return false; | |
5990 | } | |
5991 | return RECUR (DECL_VALUE_EXPR (t), rval); | |
5992 | } | |
69eb4fde | 5993 | if (want_rval |
98e5a19a | 5994 | && !var_in_maybe_constexpr_fn (t) |
7dc2b4a2 | 5995 | && !type_dependent_expression_p (t) |
4b691b13 | 5996 | && !decl_maybe_constant_var_p (t) |
69eb4fde JM |
5997 | && (strict |
5998 | || !CP_TYPE_CONST_NON_VOLATILE_P (TREE_TYPE (t)) | |
4b691b13 JM |
5999 | || (DECL_INITIAL (t) |
6000 | && !DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (t))) | |
7dc2b4a2 | 6001 | && COMPLETE_TYPE_P (TREE_TYPE (t)) |
dbcd32f8 | 6002 | && !is_really_empty_class (TREE_TYPE (t), /*ignore_vptr*/false)) |
2d76680f PC |
6003 | { |
6004 | if (flags & tf_error) | |
6005 | non_const_var_error (t); | |
6006 | return false; | |
6007 | } | |
6008 | return true; | |
6009 | ||
6010 | case NOP_EXPR: | |
ed3ea9f2 JJ |
6011 | if (REINTERPRET_CAST_P (t)) |
6012 | { | |
6013 | if (flags & tf_error) | |
6014 | error_at (loc, "a reinterpret_cast is not a constant expression"); | |
6015 | return false; | |
6016 | } | |
6017 | /* FALLTHRU */ | |
2d76680f PC |
6018 | case CONVERT_EXPR: |
6019 | case VIEW_CONVERT_EXPR: | |
6020 | /* -- a reinterpret_cast. FIXME not implemented, and this rule | |
6021 | may change to something more specific to type-punning (DR 1312). */ | |
6022 | { | |
6023 | tree from = TREE_OPERAND (t, 0); | |
dfd7fdca DM |
6024 | if (location_wrapper_p (t)) |
6025 | return (RECUR (from, want_rval)); | |
6026 | if (INDIRECT_TYPE_P (TREE_TYPE (t))) | |
2d76680f | 6027 | { |
dfd7fdca DM |
6028 | STRIP_ANY_LOCATION_WRAPPER (from); |
6029 | if (TREE_CODE (from) == INTEGER_CST | |
6030 | && !integer_zerop (from)) | |
6031 | { | |
6032 | if (flags & tf_error) | |
6033 | error_at (loc, "reinterpret_cast from integer to pointer"); | |
6034 | return false; | |
6035 | } | |
2d76680f | 6036 | } |
69eb4fde | 6037 | return (RECUR (from, TREE_CODE (t) != VIEW_CONVERT_EXPR)); |
2d76680f PC |
6038 | } |
6039 | ||
be845b04 JJ |
6040 | case ADDRESSOF_EXPR: |
6041 | /* This is like ADDR_EXPR, except it won't form pointer-to-member. */ | |
6042 | t = TREE_OPERAND (t, 0); | |
6043 | goto handle_addr_expr; | |
6044 | ||
2d76680f PC |
6045 | case ADDR_EXPR: |
6046 | /* -- a unary operator & that is applied to an lvalue that | |
6047 | designates an object with thread or automatic storage | |
6048 | duration; */ | |
6049 | t = TREE_OPERAND (t, 0); | |
6050 | ||
6051 | if (TREE_CODE (t) == OFFSET_REF && PTRMEM_OK_P (t)) | |
6052 | /* A pointer-to-member constant. */ | |
6053 | return true; | |
6054 | ||
be845b04 | 6055 | handle_addr_expr: |
2d76680f PC |
6056 | #if 0 |
6057 | /* FIXME adjust when issue 1197 is fully resolved. For now don't do | |
6058 | any checking here, as we might dereference the pointer later. If | |
6059 | we remove this code, also remove check_automatic_or_tls. */ | |
6060 | i = check_automatic_or_tls (t); | |
6061 | if (i == ck_ok) | |
6062 | return true; | |
6063 | if (i == ck_bad) | |
6064 | { | |
6065 | if (flags & tf_error) | |
6066 | error ("address-of an object %qE with thread local or " | |
6067 | "automatic storage is not a constant expression", t); | |
6068 | return false; | |
6069 | } | |
6070 | #endif | |
69eb4fde | 6071 | return RECUR (t, any); |
2d76680f | 6072 | |
dc8d2d00 JM |
6073 | case REALPART_EXPR: |
6074 | case IMAGPART_EXPR: | |
2d76680f PC |
6075 | case COMPONENT_REF: |
6076 | case BIT_FIELD_REF: | |
6077 | case ARROW_EXPR: | |
6078 | case OFFSET_REF: | |
6079 | /* -- a class member access unless its postfix-expression is | |
6080 | of literal type or of pointer to literal type. */ | |
6081 | /* This test would be redundant, as it follows from the | |
6082 | postfix-expression being a potential constant expression. */ | |
19dedccf JM |
6083 | if (type_unknown_p (t)) |
6084 | return true; | |
69eb4fde | 6085 | return RECUR (TREE_OPERAND (t, 0), want_rval); |
2d76680f PC |
6086 | |
6087 | case EXPR_PACK_EXPANSION: | |
69eb4fde | 6088 | return RECUR (PACK_EXPANSION_PATTERN (t), want_rval); |
2d76680f PC |
6089 | |
6090 | case INDIRECT_REF: | |
6091 | { | |
6092 | tree x = TREE_OPERAND (t, 0); | |
6093 | STRIP_NOPS (x); | |
948d0d91 | 6094 | if (is_this_parameter (x) && !is_capture_proxy (x)) |
2d76680f | 6095 | { |
5d4e573b | 6096 | if (!var_in_maybe_constexpr_fn (x)) |
2d76680f PC |
6097 | { |
6098 | if (flags & tf_error) | |
e40b6fc7 | 6099 | error_at (loc, "use of %<this%> in a constant expression"); |
2d76680f PC |
6100 | return false; |
6101 | } | |
2d76680f PC |
6102 | return true; |
6103 | } | |
69eb4fde | 6104 | return RECUR (x, rval); |
2d76680f PC |
6105 | } |
6106 | ||
60813a46 JM |
6107 | case STATEMENT_LIST: |
6108 | { | |
6109 | tree_stmt_iterator i; | |
6110 | for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i)) | |
6111 | { | |
69eb4fde | 6112 | if (!RECUR (tsi_stmt (i), any)) |
60813a46 JM |
6113 | return false; |
6114 | } | |
6115 | return true; | |
6116 | } | |
6117 | break; | |
6118 | ||
6119 | case MODIFY_EXPR: | |
6120 | if (cxx_dialect < cxx14) | |
6121 | goto fail; | |
69eb4fde | 6122 | if (!RECUR (TREE_OPERAND (t, 0), any)) |
60813a46 | 6123 | return false; |
69eb4fde | 6124 | if (!RECUR (TREE_OPERAND (t, 1), rval)) |
60813a46 JM |
6125 | return false; |
6126 | return true; | |
6127 | ||
6128 | case MODOP_EXPR: | |
6129 | if (cxx_dialect < cxx14) | |
6130 | goto fail; | |
69eb4fde | 6131 | if (!RECUR (TREE_OPERAND (t, 0), rval)) |
60813a46 | 6132 | return false; |
69eb4fde | 6133 | if (!RECUR (TREE_OPERAND (t, 2), rval)) |
60813a46 JM |
6134 | return false; |
6135 | return true; | |
6136 | ||
60813a46 | 6137 | case DO_STMT: |
69eb4fde | 6138 | if (!RECUR (DO_COND (t), rval)) |
60813a46 | 6139 | return false; |
69eb4fde | 6140 | if (!RECUR (DO_BODY (t), any)) |
60813a46 | 6141 | return false; |
3075affd JM |
6142 | if (breaks (jump_target) || continues (jump_target)) |
6143 | *jump_target = NULL_TREE; | |
60813a46 JM |
6144 | return true; |
6145 | ||
6146 | case FOR_STMT: | |
69eb4fde | 6147 | if (!RECUR (FOR_INIT_STMT (t), any)) |
60813a46 | 6148 | return false; |
8e9558f0 MP |
6149 | tmp = FOR_COND (t); |
6150 | if (!RECUR (tmp, rval)) | |
60813a46 | 6151 | return false; |
8e9558f0 MP |
6152 | if (tmp) |
6153 | { | |
6154 | if (!processing_template_decl) | |
6155 | tmp = cxx_eval_outermost_constant_expr (tmp, true); | |
a385474c MP |
6156 | /* If we couldn't evaluate the condition, it might not ever be |
6157 | true. */ | |
6158 | if (!integer_onep (tmp)) | |
8e9558f0 MP |
6159 | return true; |
6160 | } | |
69eb4fde | 6161 | if (!RECUR (FOR_EXPR (t), any)) |
60813a46 | 6162 | return false; |
69eb4fde | 6163 | if (!RECUR (FOR_BODY (t), any)) |
60813a46 | 6164 | return false; |
3075affd JM |
6165 | if (breaks (jump_target) || continues (jump_target)) |
6166 | *jump_target = NULL_TREE; | |
60813a46 JM |
6167 | return true; |
6168 | ||
98e5a19a | 6169 | case RANGE_FOR_STMT: |
8112667c MP |
6170 | if (!RECUR (RANGE_FOR_INIT_STMT (t), any)) |
6171 | return false; | |
98e5a19a JM |
6172 | if (!RECUR (RANGE_FOR_EXPR (t), any)) |
6173 | return false; | |
6174 | if (!RECUR (RANGE_FOR_BODY (t), any)) | |
6175 | return false; | |
3075affd JM |
6176 | if (breaks (jump_target) || continues (jump_target)) |
6177 | *jump_target = NULL_TREE; | |
98e5a19a JM |
6178 | return true; |
6179 | ||
60813a46 | 6180 | case WHILE_STMT: |
8e9558f0 MP |
6181 | tmp = WHILE_COND (t); |
6182 | if (!RECUR (tmp, rval)) | |
60813a46 | 6183 | return false; |
8e9558f0 MP |
6184 | if (!processing_template_decl) |
6185 | tmp = cxx_eval_outermost_constant_expr (tmp, true); | |
a385474c MP |
6186 | /* If we couldn't evaluate the condition, it might not ever be true. */ |
6187 | if (!integer_onep (tmp)) | |
8e9558f0 | 6188 | return true; |
69eb4fde | 6189 | if (!RECUR (WHILE_BODY (t), any)) |
60813a46 | 6190 | return false; |
3075affd JM |
6191 | if (breaks (jump_target) || continues (jump_target)) |
6192 | *jump_target = NULL_TREE; | |
60813a46 JM |
6193 | return true; |
6194 | ||
6195 | case SWITCH_STMT: | |
69eb4fde | 6196 | if (!RECUR (SWITCH_STMT_COND (t), rval)) |
60813a46 | 6197 | return false; |
ce965730 MT |
6198 | /* FIXME we don't check SWITCH_STMT_BODY currently, because even |
6199 | unreachable labels would be checked. */ | |
60813a46 JM |
6200 | return true; |
6201 | ||
58611fb6 | 6202 | case STMT_EXPR: |
69eb4fde | 6203 | return RECUR (STMT_EXPR_STMT (t), rval); |
58611fb6 | 6204 | |
2d76680f | 6205 | case LAMBDA_EXPR: |
899ac3b8 JM |
6206 | if (cxx_dialect >= cxx17) |
6207 | /* In C++17 lambdas can be constexpr, don't give up yet. */ | |
6208 | return true; | |
6209 | else if (flags & tf_error) | |
6210 | error_at (loc, "lambda-expression is not a constant expression " | |
6211 | "before C++17"); | |
6212 | return false; | |
6213 | ||
2d76680f PC |
6214 | case DYNAMIC_CAST_EXPR: |
6215 | case PSEUDO_DTOR_EXPR: | |
2d76680f PC |
6216 | case NEW_EXPR: |
6217 | case VEC_NEW_EXPR: | |
6218 | case DELETE_EXPR: | |
6219 | case VEC_DELETE_EXPR: | |
6220 | case THROW_EXPR: | |
e40b6fc7 JJ |
6221 | case OMP_PARALLEL: |
6222 | case OMP_TASK: | |
6223 | case OMP_FOR: | |
897064e2 | 6224 | case OMP_SIMD: |
e40b6fc7 JJ |
6225 | case OMP_DISTRIBUTE: |
6226 | case OMP_TASKLOOP: | |
6227 | case OMP_TEAMS: | |
6228 | case OMP_TARGET_DATA: | |
6229 | case OMP_TARGET: | |
6230 | case OMP_SECTIONS: | |
6231 | case OMP_ORDERED: | |
6232 | case OMP_CRITICAL: | |
6233 | case OMP_SINGLE: | |
6234 | case OMP_SECTION: | |
6235 | case OMP_MASTER: | |
6236 | case OMP_TASKGROUP: | |
6237 | case OMP_TARGET_UPDATE: | |
6238 | case OMP_TARGET_ENTER_DATA: | |
6239 | case OMP_TARGET_EXIT_DATA: | |
2d76680f PC |
6240 | case OMP_ATOMIC: |
6241 | case OMP_ATOMIC_READ: | |
6242 | case OMP_ATOMIC_CAPTURE_OLD: | |
6243 | case OMP_ATOMIC_CAPTURE_NEW: | |
28567c40 | 6244 | case OMP_DEPOBJ: |
e40b6fc7 JJ |
6245 | case OACC_PARALLEL: |
6246 | case OACC_KERNELS: | |
6247 | case OACC_DATA: | |
6248 | case OACC_HOST_DATA: | |
6249 | case OACC_LOOP: | |
6250 | case OACC_CACHE: | |
6251 | case OACC_DECLARE: | |
6252 | case OACC_ENTER_DATA: | |
6253 | case OACC_EXIT_DATA: | |
6254 | case OACC_UPDATE: | |
2d76680f PC |
6255 | /* GCC internal stuff. */ |
6256 | case VA_ARG_EXPR: | |
2d76680f | 6257 | case TRANSACTION_EXPR: |
60813a46 | 6258 | case ASM_EXPR: |
81b6a6c5 | 6259 | case AT_ENCODE_EXPR: |
60813a46 | 6260 | fail: |
2d76680f | 6261 | if (flags & tf_error) |
e40b6fc7 | 6262 | error_at (loc, "expression %qE is not a constant expression", t); |
2d76680f PC |
6263 | return false; |
6264 | ||
bf8d8309 MP |
6265 | case OBJ_TYPE_REF: |
6266 | if (cxx_dialect >= cxx2a) | |
6267 | /* In C++2a virtual calls can be constexpr, don't give up yet. */ | |
6268 | return true; | |
6269 | else if (flags & tf_error) | |
6270 | error_at (loc, "virtual functions cannot be constexpr before C++2a"); | |
6271 | return false; | |
6272 | ||
2d76680f PC |
6273 | case TYPEID_EXPR: |
6274 | /* -- a typeid expression whose operand is of polymorphic | |
6275 | class type; */ | |
6276 | { | |
6277 | tree e = TREE_OPERAND (t, 0); | |
6278 | if (!TYPE_P (e) && !type_dependent_expression_p (e) | |
6279 | && TYPE_POLYMORPHIC_P (TREE_TYPE (e))) | |
6280 | { | |
6281 | if (flags & tf_error) | |
e40b6fc7 JJ |
6282 | error_at (loc, "typeid-expression is not a constant expression " |
6283 | "because %qE is of polymorphic type", e); | |
2d76680f PC |
6284 | return false; |
6285 | } | |
6286 | return true; | |
6287 | } | |
6288 | ||
1af4ebf5 | 6289 | case POINTER_DIFF_EXPR: |
2d76680f | 6290 | case MINUS_EXPR: |
2d76680f PC |
6291 | want_rval = true; |
6292 | goto binary; | |
6293 | ||
6294 | case LT_EXPR: | |
6295 | case LE_EXPR: | |
6296 | case GT_EXPR: | |
6297 | case GE_EXPR: | |
6298 | case EQ_EXPR: | |
6299 | case NE_EXPR: | |
2d76680f PC |
6300 | want_rval = true; |
6301 | goto binary; | |
6302 | ||
60813a46 JM |
6303 | case PREINCREMENT_EXPR: |
6304 | case POSTINCREMENT_EXPR: | |
6305 | case PREDECREMENT_EXPR: | |
6306 | case POSTDECREMENT_EXPR: | |
6307 | if (cxx_dialect < cxx14) | |
6308 | goto fail; | |
6309 | goto unary; | |
6310 | ||
2d76680f PC |
6311 | case BIT_NOT_EXPR: |
6312 | /* A destructor. */ | |
6313 | if (TYPE_P (TREE_OPERAND (t, 0))) | |
6314 | return true; | |
191816a3 | 6315 | /* fall through. */ |
2d76680f | 6316 | |
2d76680f PC |
6317 | case CONJ_EXPR: |
6318 | case SAVE_EXPR: | |
6319 | case FIX_TRUNC_EXPR: | |
6320 | case FLOAT_EXPR: | |
6321 | case NEGATE_EXPR: | |
6322 | case ABS_EXPR: | |
e197e64e | 6323 | case ABSU_EXPR: |
2d76680f PC |
6324 | case TRUTH_NOT_EXPR: |
6325 | case FIXED_CONVERT_EXPR: | |
6326 | case UNARY_PLUS_EXPR: | |
4856a1f0 PC |
6327 | case UNARY_LEFT_FOLD_EXPR: |
6328 | case UNARY_RIGHT_FOLD_EXPR: | |
60813a46 | 6329 | unary: |
69eb4fde | 6330 | return RECUR (TREE_OPERAND (t, 0), rval); |
2d76680f PC |
6331 | |
6332 | case CAST_EXPR: | |
6333 | case CONST_CAST_EXPR: | |
6334 | case STATIC_CAST_EXPR: | |
6335 | case REINTERPRET_CAST_EXPR: | |
6336 | case IMPLICIT_CONV_EXPR: | |
6337 | if (cxx_dialect < cxx11 | |
6338 | && !dependent_type_p (TREE_TYPE (t)) | |
6339 | && !INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))) | |
6340 | /* In C++98, a conversion to non-integral type can't be part of a | |
6341 | constant expression. */ | |
6342 | { | |
6343 | if (flags & tf_error) | |
e40b6fc7 JJ |
6344 | error_at (loc, |
6345 | "cast to non-integral type %qT in a constant expression", | |
6346 | TREE_TYPE (t)); | |
2d76680f PC |
6347 | return false; |
6348 | } | |
fe0604d3 MP |
6349 | /* This might be a conversion from a class to a (potentially) literal |
6350 | type. Let's consider it potentially constant since the conversion | |
6351 | might be a constexpr user-defined conversion. */ | |
6352 | else if (cxx_dialect >= cxx11 | |
6353 | && (dependent_type_p (TREE_TYPE (t)) | |
6354 | || !COMPLETE_TYPE_P (TREE_TYPE (t)) | |
6355 | || literal_type_p (TREE_TYPE (t))) | |
6356 | && TREE_OPERAND (t, 0)) | |
6357 | { | |
6358 | tree type = TREE_TYPE (TREE_OPERAND (t, 0)); | |
6359 | /* If this is a dependent type, it could end up being a class | |
6360 | with conversions. */ | |
6361 | if (type == NULL_TREE || WILDCARD_TYPE_P (type)) | |
6362 | return true; | |
6363 | /* Or a non-dependent class which has conversions. */ | |
6364 | else if (CLASS_TYPE_P (type) | |
6365 | && (TYPE_HAS_CONVERSION (type) || dependent_scope_p (type))) | |
6366 | return true; | |
6367 | } | |
2d76680f | 6368 | |
69eb4fde | 6369 | return (RECUR (TREE_OPERAND (t, 0), |
9f613f06 | 6370 | !TYPE_REF_P (TREE_TYPE (t)))); |
2d76680f | 6371 | |
60813a46 | 6372 | case BIND_EXPR: |
69eb4fde | 6373 | return RECUR (BIND_EXPR_BODY (t), want_rval); |
60813a46 | 6374 | |
60813a46 JM |
6375 | case CLEANUP_POINT_EXPR: |
6376 | case MUST_NOT_THROW_EXPR: | |
6377 | case TRY_CATCH_EXPR: | |
769430b2 | 6378 | case TRY_BLOCK: |
60813a46 JM |
6379 | case EH_SPEC_BLOCK: |
6380 | case EXPR_STMT: | |
2d76680f PC |
6381 | case PAREN_EXPR: |
6382 | case NON_DEPENDENT_EXPR: | |
6383 | /* For convenience. */ | |
f937929e JM |
6384 | case LOOP_EXPR: |
6385 | case EXIT_EXPR: | |
69eb4fde | 6386 | return RECUR (TREE_OPERAND (t, 0), want_rval); |
2d76680f | 6387 | |
98e5a19a JM |
6388 | case DECL_EXPR: |
6389 | tmp = DECL_EXPR_DECL (t); | |
6390 | if (VAR_P (tmp) && !DECL_ARTIFICIAL (tmp)) | |
6391 | { | |
6392 | if (TREE_STATIC (tmp)) | |
6393 | { | |
6394 | if (flags & tf_error) | |
6395 | error_at (DECL_SOURCE_LOCATION (tmp), "%qD declared " | |
4b691b13 | 6396 | "%<static%> in %<constexpr%> context", tmp); |
98e5a19a JM |
6397 | return false; |
6398 | } | |
6399 | else if (CP_DECL_THREAD_LOCAL_P (tmp)) | |
6400 | { | |
6401 | if (flags & tf_error) | |
6402 | error_at (DECL_SOURCE_LOCATION (tmp), "%qD declared " | |
4b691b13 | 6403 | "%<thread_local%> in %<constexpr%> context", tmp); |
98e5a19a JM |
6404 | return false; |
6405 | } | |
3885527d PC |
6406 | else if (!check_for_uninitialized_const_var |
6407 | (tmp, /*constexpr_context_p=*/true, flags)) | |
6408 | return false; | |
98e5a19a JM |
6409 | } |
6410 | return RECUR (tmp, want_rval); | |
6411 | ||
769430b2 JM |
6412 | case TRY_FINALLY_EXPR: |
6413 | return (RECUR (TREE_OPERAND (t, 0), want_rval) | |
6414 | && RECUR (TREE_OPERAND (t, 1), any)); | |
6415 | ||
2d76680f | 6416 | case SCOPE_REF: |
69eb4fde | 6417 | return RECUR (TREE_OPERAND (t, 1), want_rval); |
2d76680f PC |
6418 | |
6419 | case TARGET_EXPR: | |
d3a9902e JM |
6420 | if (!TARGET_EXPR_DIRECT_INIT_P (t) |
6421 | && !literal_type_p (TREE_TYPE (t))) | |
2d76680f PC |
6422 | { |
6423 | if (flags & tf_error) | |
6424 | { | |
097f82ec | 6425 | auto_diagnostic_group d; |
e40b6fc7 JJ |
6426 | error_at (loc, "temporary of non-literal type %qT in a " |
6427 | "constant expression", TREE_TYPE (t)); | |
2d76680f PC |
6428 | explain_non_literal_class (TREE_TYPE (t)); |
6429 | } | |
6430 | return false; | |
6431 | } | |
191816a3 | 6432 | /* FALLTHRU */ |
2d76680f | 6433 | case INIT_EXPR: |
69eb4fde | 6434 | return RECUR (TREE_OPERAND (t, 1), rval); |
2d76680f PC |
6435 | |
6436 | case CONSTRUCTOR: | |
6437 | { | |
6438 | vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (t); | |
6439 | constructor_elt *ce; | |
6440 | for (i = 0; vec_safe_iterate (v, i, &ce); ++i) | |
69eb4fde | 6441 | if (!RECUR (ce->value, want_rval)) |
2d76680f PC |
6442 | return false; |
6443 | return true; | |
6444 | } | |
6445 | ||
6446 | case TREE_LIST: | |
6447 | { | |
6448 | gcc_assert (TREE_PURPOSE (t) == NULL_TREE | |
6449 | || DECL_P (TREE_PURPOSE (t))); | |
69eb4fde | 6450 | if (!RECUR (TREE_VALUE (t), want_rval)) |
2d76680f PC |
6451 | return false; |
6452 | if (TREE_CHAIN (t) == NULL_TREE) | |
6453 | return true; | |
69eb4fde | 6454 | return RECUR (TREE_CHAIN (t), want_rval); |
2d76680f PC |
6455 | } |
6456 | ||
6457 | case TRUNC_DIV_EXPR: | |
6458 | case CEIL_DIV_EXPR: | |
6459 | case FLOOR_DIV_EXPR: | |
6460 | case ROUND_DIV_EXPR: | |
6461 | case TRUNC_MOD_EXPR: | |
6462 | case CEIL_MOD_EXPR: | |
6463 | case ROUND_MOD_EXPR: | |
6464 | { | |
6465 | tree denom = TREE_OPERAND (t, 1); | |
69eb4fde | 6466 | if (!RECUR (denom, rval)) |
2d76680f PC |
6467 | return false; |
6468 | /* We can't call cxx_eval_outermost_constant_expr on an expression | |
234bef96 | 6469 | that hasn't been through instantiate_non_dependent_expr yet. */ |
2d76680f PC |
6470 | if (!processing_template_decl) |
6471 | denom = cxx_eval_outermost_constant_expr (denom, true); | |
6472 | if (integer_zerop (denom)) | |
6473 | { | |
6474 | if (flags & tf_error) | |
64d6d399 | 6475 | error ("division by zero is not a constant expression"); |
2d76680f PC |
6476 | return false; |
6477 | } | |
6478 | else | |
6479 | { | |
6480 | want_rval = true; | |
69eb4fde | 6481 | return RECUR (TREE_OPERAND (t, 0), want_rval); |
2d76680f PC |
6482 | } |
6483 | } | |
6484 | ||
6485 | case COMPOUND_EXPR: | |
6486 | { | |
6487 | /* check_return_expr sometimes wraps a TARGET_EXPR in a | |
6488 | COMPOUND_EXPR; don't get confused. Also handle EMPTY_CLASS_EXPR | |
6489 | introduced by build_call_a. */ | |
6490 | tree op0 = TREE_OPERAND (t, 0); | |
6491 | tree op1 = TREE_OPERAND (t, 1); | |
6492 | STRIP_NOPS (op1); | |
6493 | if ((TREE_CODE (op0) == TARGET_EXPR && op1 == TARGET_EXPR_SLOT (op0)) | |
6494 | || TREE_CODE (op1) == EMPTY_CLASS_EXPR) | |
69eb4fde | 6495 | return RECUR (op0, want_rval); |
2d76680f PC |
6496 | else |
6497 | goto binary; | |
6498 | } | |
6499 | ||
6500 | /* If the first operand is the non-short-circuit constant, look at | |
6501 | the second operand; otherwise we only care about the first one for | |
6502 | potentiality. */ | |
6503 | case TRUTH_AND_EXPR: | |
6504 | case TRUTH_ANDIF_EXPR: | |
6505 | tmp = boolean_true_node; | |
6506 | goto truth; | |
6507 | case TRUTH_OR_EXPR: | |
6508 | case TRUTH_ORIF_EXPR: | |
6509 | tmp = boolean_false_node; | |
6510 | truth: | |
6511 | { | |
6512 | tree op = TREE_OPERAND (t, 0); | |
69eb4fde | 6513 | if (!RECUR (op, rval)) |
2d76680f PC |
6514 | return false; |
6515 | if (!processing_template_decl) | |
6516 | op = cxx_eval_outermost_constant_expr (op, true); | |
6517 | if (tree_int_cst_equal (op, tmp)) | |
69eb4fde | 6518 | return RECUR (TREE_OPERAND (t, 1), rval); |
2d76680f PC |
6519 | else |
6520 | return true; | |
6521 | } | |
6522 | ||
6523 | case PLUS_EXPR: | |
6524 | case MULT_EXPR: | |
6525 | case POINTER_PLUS_EXPR: | |
6526 | case RDIV_EXPR: | |
6527 | case EXACT_DIV_EXPR: | |
6528 | case MIN_EXPR: | |
6529 | case MAX_EXPR: | |
6530 | case LSHIFT_EXPR: | |
6531 | case RSHIFT_EXPR: | |
6532 | case LROTATE_EXPR: | |
6533 | case RROTATE_EXPR: | |
6534 | case BIT_IOR_EXPR: | |
6535 | case BIT_XOR_EXPR: | |
6536 | case BIT_AND_EXPR: | |
6537 | case TRUTH_XOR_EXPR: | |
6538 | case UNORDERED_EXPR: | |
6539 | case ORDERED_EXPR: | |
6540 | case UNLT_EXPR: | |
6541 | case UNLE_EXPR: | |
6542 | case UNGT_EXPR: | |
6543 | case UNGE_EXPR: | |
6544 | case UNEQ_EXPR: | |
6545 | case LTGT_EXPR: | |
6546 | case RANGE_EXPR: | |
6547 | case COMPLEX_EXPR: | |
6548 | want_rval = true; | |
6549 | /* Fall through. */ | |
6550 | case ARRAY_REF: | |
6551 | case ARRAY_RANGE_REF: | |
6552 | case MEMBER_REF: | |
6553 | case DOTSTAR_EXPR: | |
41b38772 | 6554 | case MEM_REF: |
4856a1f0 PC |
6555 | case BINARY_LEFT_FOLD_EXPR: |
6556 | case BINARY_RIGHT_FOLD_EXPR: | |
2d76680f PC |
6557 | binary: |
6558 | for (i = 0; i < 2; ++i) | |
69eb4fde | 6559 | if (!RECUR (TREE_OPERAND (t, i), want_rval)) |
2d76680f PC |
6560 | return false; |
6561 | return true; | |
6562 | ||
2d76680f PC |
6563 | case VEC_PERM_EXPR: |
6564 | for (i = 0; i < 3; ++i) | |
69eb4fde | 6565 | if (!RECUR (TREE_OPERAND (t, i), true)) |
2d76680f PC |
6566 | return false; |
6567 | return true; | |
6568 | ||
6569 | case COND_EXPR: | |
d5bcd6d4 JM |
6570 | if (COND_EXPR_IS_VEC_DELETE (t)) |
6571 | { | |
6572 | if (flags & tf_error) | |
e40b6fc7 | 6573 | error_at (loc, "%<delete[]%> is not a constant expression"); |
d5bcd6d4 JM |
6574 | return false; |
6575 | } | |
6576 | /* Fall through. */ | |
6577 | case IF_STMT: | |
2d76680f PC |
6578 | case VEC_COND_EXPR: |
6579 | /* If the condition is a known constant, we know which of the legs we | |
6580 | care about; otherwise we only require that the condition and | |
6581 | either of the legs be potentially constant. */ | |
6582 | tmp = TREE_OPERAND (t, 0); | |
69eb4fde | 6583 | if (!RECUR (tmp, rval)) |
2d76680f PC |
6584 | return false; |
6585 | if (!processing_template_decl) | |
6586 | tmp = cxx_eval_outermost_constant_expr (tmp, true); | |
6587 | if (integer_zerop (tmp)) | |
69eb4fde | 6588 | return RECUR (TREE_OPERAND (t, 2), want_rval); |
2d76680f | 6589 | else if (TREE_CODE (tmp) == INTEGER_CST) |
69eb4fde | 6590 | return RECUR (TREE_OPERAND (t, 1), want_rval); |
2d76680f PC |
6591 | for (i = 1; i < 3; ++i) |
6592 | if (potential_constant_expression_1 (TREE_OPERAND (t, i), | |
3075affd JM |
6593 | want_rval, strict, now, |
6594 | tf_none, jump_target)) | |
2d76680f PC |
6595 | return true; |
6596 | if (flags & tf_error) | |
e40b6fc7 | 6597 | error_at (loc, "expression %qE is not a constant expression", t); |
2d76680f PC |
6598 | return false; |
6599 | ||
6600 | case VEC_INIT_EXPR: | |
6601 | if (VEC_INIT_EXPR_IS_CONSTEXPR (t)) | |
6602 | return true; | |
6603 | if (flags & tf_error) | |
6604 | { | |
e40b6fc7 | 6605 | error_at (loc, "non-constant array initialization"); |
2d76680f PC |
6606 | diagnose_non_constexpr_vec_init (t); |
6607 | } | |
6608 | return false; | |
6609 | ||
133bc698 JM |
6610 | case TYPE_DECL: |
6611 | case TAG_DEFN: | |
6612 | /* We can see these in statement-expressions. */ | |
6613 | return true; | |
6614 | ||
baf9ebc8 | 6615 | case CLEANUP_STMT: |
cda0a029 | 6616 | case EMPTY_CLASS_EXPR: |
7fef86d3 | 6617 | case PREDICT_EXPR: |
cda0a029 JM |
6618 | return false; |
6619 | ||
f937929e JM |
6620 | case GOTO_EXPR: |
6621 | { | |
6622 | tree *target = &TREE_OPERAND (t, 0); | |
ab3af181 JJ |
6623 | /* Gotos representing break and continue are OK. */ |
6624 | if (breaks (target) || continues (target)) | |
3075affd JM |
6625 | { |
6626 | *jump_target = *target; | |
6627 | return true; | |
6628 | } | |
ab3af181 | 6629 | if (flags & tf_error) |
e40b6fc7 | 6630 | error_at (loc, "%<goto%> is not a constant expression"); |
ab3af181 | 6631 | return false; |
f937929e JM |
6632 | } |
6633 | ||
98e09245 | 6634 | case ANNOTATE_EXPR: |
98e09245 JJ |
6635 | return RECUR (TREE_OPERAND (t, 0), rval); |
6636 | ||
2d76680f PC |
6637 | default: |
6638 | if (objc_is_property_ref (t)) | |
6639 | return false; | |
6640 | ||
6641 | sorry ("unexpected AST of kind %s", get_tree_code_name (TREE_CODE (t))); | |
ab3af181 | 6642 | gcc_unreachable (); |
2d76680f PC |
6643 | return false; |
6644 | } | |
69eb4fde | 6645 | #undef RECUR |
2d76680f PC |
6646 | } |
6647 | ||
3075affd JM |
6648 | bool |
6649 | potential_constant_expression_1 (tree t, bool want_rval, bool strict, bool now, | |
6650 | tsubst_flags_t flags) | |
6651 | { | |
6652 | tree target = NULL_TREE; | |
6653 | return potential_constant_expression_1 (t, want_rval, strict, now, | |
6654 | flags, &target); | |
6655 | } | |
6656 | ||
2d76680f PC |
6657 | /* The main entry point to the above. */ |
6658 | ||
6659 | bool | |
6660 | potential_constant_expression (tree t) | |
6661 | { | |
a0ab7ccd | 6662 | return potential_constant_expression_1 (t, false, true, false, tf_none); |
2d76680f PC |
6663 | } |
6664 | ||
6665 | /* As above, but require a constant rvalue. */ | |
6666 | ||
6667 | bool | |
6668 | potential_rvalue_constant_expression (tree t) | |
6669 | { | |
a0ab7ccd | 6670 | return potential_constant_expression_1 (t, true, true, false, tf_none); |
2d76680f PC |
6671 | } |
6672 | ||
6673 | /* Like above, but complain about non-constant expressions. */ | |
6674 | ||
6675 | bool | |
6676 | require_potential_constant_expression (tree t) | |
6677 | { | |
d8cff23f MP |
6678 | return potential_constant_expression_1 (t, false, true, false, |
6679 | tf_warning_or_error); | |
2d76680f PC |
6680 | } |
6681 | ||
6682 | /* Cross product of the above. */ | |
6683 | ||
6684 | bool | |
6685 | require_potential_rvalue_constant_expression (tree t) | |
6686 | { | |
d8cff23f MP |
6687 | return potential_constant_expression_1 (t, true, true, false, |
6688 | tf_warning_or_error); | |
6689 | } | |
6690 | ||
6691 | /* Like above, but don't consider PARM_DECL a potential_constant_expression. */ | |
6692 | ||
6693 | bool | |
6694 | require_rvalue_constant_expression (tree t) | |
6695 | { | |
6696 | return potential_constant_expression_1 (t, true, true, true, | |
6697 | tf_warning_or_error); | |
a0ab7ccd JM |
6698 | } |
6699 | ||
6700 | /* Like potential_constant_expression, but don't consider possible constexpr | |
6701 | substitution of the current function. That is, PARM_DECL qualifies under | |
6702 | potential_constant_expression, but not here. | |
6703 | ||
6704 | This is basically what you can check when any actual constant values might | |
6705 | be value-dependent. */ | |
6706 | ||
6707 | bool | |
6708 | is_constant_expression (tree t) | |
6709 | { | |
6710 | return potential_constant_expression_1 (t, false, true, true, tf_none); | |
6711 | } | |
6712 | ||
6713 | /* Like above, but complain about non-constant expressions. */ | |
6714 | ||
6715 | bool | |
6716 | require_constant_expression (tree t) | |
6717 | { | |
6718 | return potential_constant_expression_1 (t, false, true, true, | |
6719 | tf_warning_or_error); | |
6720 | } | |
6721 | ||
6722 | /* Like is_constant_expression, but allow const variables that are not allowed | |
6723 | under constexpr rules. */ | |
6724 | ||
6725 | bool | |
6726 | is_static_init_expression (tree t) | |
6727 | { | |
6728 | return potential_constant_expression_1 (t, false, false, true, tf_none); | |
2d76680f PC |
6729 | } |
6730 | ||
eb07f187 JM |
6731 | /* Returns true if T is a potential constant expression that is not |
6732 | instantiation-dependent, and therefore a candidate for constant folding even | |
6733 | in a template. */ | |
6734 | ||
6735 | bool | |
a0ab7ccd | 6736 | is_nondependent_constant_expression (tree t) |
eb07f187 JM |
6737 | { |
6738 | return (!type_unknown_p (t) | |
6739 | && !BRACE_ENCLOSED_INITIALIZER_P (t) | |
a0ab7ccd | 6740 | && is_constant_expression (t) |
eb07f187 JM |
6741 | && !instantiation_dependent_expression_p (t)); |
6742 | } | |
6743 | ||
6744 | /* Returns true if T is a potential static initializer expression that is not | |
6745 | instantiation-dependent. */ | |
6746 | ||
6747 | bool | |
a0ab7ccd | 6748 | is_nondependent_static_init_expression (tree t) |
eb07f187 JM |
6749 | { |
6750 | return (!type_unknown_p (t) | |
6751 | && !BRACE_ENCLOSED_INITIALIZER_P (t) | |
a0ab7ccd | 6752 | && is_static_init_expression (t) |
eb07f187 JM |
6753 | && !instantiation_dependent_expression_p (t)); |
6754 | } | |
6755 | ||
97f3003f JM |
6756 | /* Finalize constexpr processing after parsing. */ |
6757 | ||
6758 | void | |
6759 | fini_constexpr (void) | |
6760 | { | |
6761 | /* The contexpr call and fundef copies tables are no longer needed. */ | |
6762 | constexpr_call_table = NULL; | |
6763 | fundef_copies_table = NULL; | |
6764 | } | |
6765 | ||
2d76680f | 6766 | #include "gt-cp-constexpr.h" |