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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 | ||
8d9254fc | 5 | Copyright (C) 1998-2020 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" |
8e007055 | 37 | #include "stor-layout.h" |
2d76680f PC |
38 | |
39 | static bool verify_constant (tree, bool, bool *, bool *); | |
40 | #define VERIFY_CONSTANT(X) \ | |
41 | do { \ | |
2b3ab879 | 42 | if (verify_constant ((X), ctx->quiet, non_constant_p, overflow_p)) \ |
2d76680f PC |
43 | return t; \ |
44 | } while (0) | |
45 | ||
582d2481 JJ |
46 | static HOST_WIDE_INT find_array_ctor_elt (tree ary, tree dindex, |
47 | bool insert = false); | |
48 | ||
2d76680f PC |
49 | /* Returns true iff FUN is an instantiation of a constexpr function |
50 | template or a defaulted constexpr function. */ | |
51 | ||
52 | bool | |
53 | is_instantiation_of_constexpr (tree fun) | |
54 | { | |
55 | return ((DECL_TEMPLOID_INSTANTIATION (fun) | |
56 | && DECL_DECLARED_CONSTEXPR_P (DECL_TI_TEMPLATE (fun))) | |
57 | || (DECL_DEFAULTED_FN (fun) | |
58 | && DECL_DECLARED_CONSTEXPR_P (fun))); | |
59 | } | |
60 | ||
61 | /* Return true if T is a literal type. */ | |
62 | ||
63 | bool | |
64 | literal_type_p (tree t) | |
65 | { | |
66 | if (SCALAR_TYPE_P (t) | |
b55b02ea | 67 | || VECTOR_TYPE_P (t) |
9f613f06 | 68 | || TYPE_REF_P (t) |
e42c407c | 69 | || (VOID_TYPE_P (t) && cxx_dialect >= cxx14)) |
2d76680f PC |
70 | return true; |
71 | if (CLASS_TYPE_P (t)) | |
72 | { | |
73 | t = complete_type (t); | |
74 | gcc_assert (COMPLETE_TYPE_P (t) || errorcount); | |
75 | return CLASSTYPE_LITERAL_P (t); | |
76 | } | |
77 | if (TREE_CODE (t) == ARRAY_TYPE) | |
78 | return literal_type_p (strip_array_types (t)); | |
79 | return false; | |
80 | } | |
81 | ||
82 | /* If DECL is a variable declared `constexpr', require its type | |
9638f320 PC |
83 | be literal. Return error_mark_node if we give an error, the |
84 | DECL otherwise. */ | |
2d76680f PC |
85 | |
86 | tree | |
87 | ensure_literal_type_for_constexpr_object (tree decl) | |
88 | { | |
89 | tree type = TREE_TYPE (decl); | |
90 | if (VAR_P (decl) | |
91 | && (DECL_DECLARED_CONSTEXPR_P (decl) | |
92 | || var_in_constexpr_fn (decl)) | |
93 | && !processing_template_decl) | |
94 | { | |
95 | tree stype = strip_array_types (type); | |
96 | if (CLASS_TYPE_P (stype) && !COMPLETE_TYPE_P (complete_type (stype))) | |
97 | /* Don't complain here, we'll complain about incompleteness | |
98 | when we try to initialize the variable. */; | |
99 | else if (!literal_type_p (type)) | |
100 | { | |
101 | if (DECL_DECLARED_CONSTEXPR_P (decl)) | |
f1eac182 | 102 | { |
097f82ec | 103 | auto_diagnostic_group d; |
f2935576 PC |
104 | error_at (DECL_SOURCE_LOCATION (decl), |
105 | "the type %qT of %<constexpr%> variable %qD " | |
106 | "is not literal", type, decl); | |
f1eac182 | 107 | explain_non_literal_class (type); |
9638f320 | 108 | decl = error_mark_node; |
f1eac182 | 109 | } |
2d76680f | 110 | else |
60813a46 | 111 | { |
5d4e573b | 112 | if (!is_instantiation_of_constexpr (current_function_decl)) |
f1eac182 | 113 | { |
097f82ec | 114 | auto_diagnostic_group d; |
f2935576 PC |
115 | error_at (DECL_SOURCE_LOCATION (decl), |
116 | "variable %qD of non-literal type %qT in " | |
117 | "%<constexpr%> function", decl, type); | |
f1eac182 | 118 | explain_non_literal_class (type); |
9638f320 | 119 | decl = error_mark_node; |
f1eac182 | 120 | } |
60813a46 JM |
121 | cp_function_chain->invalid_constexpr = true; |
122 | } | |
2d76680f | 123 | } |
8e9589bd JM |
124 | else if (DECL_DECLARED_CONSTEXPR_P (decl) |
125 | && variably_modified_type_p (type, NULL_TREE)) | |
126 | { | |
f2935576 PC |
127 | error_at (DECL_SOURCE_LOCATION (decl), |
128 | "%<constexpr%> variable %qD has variably-modified " | |
129 | "type %qT", decl, type); | |
8e9589bd JM |
130 | decl = error_mark_node; |
131 | } | |
2d76680f PC |
132 | } |
133 | return decl; | |
134 | } | |
135 | ||
ca752f39 | 136 | struct constexpr_fundef_hasher : ggc_ptr_hash<constexpr_fundef> |
2d76680f | 137 | { |
bfc139e2 NS |
138 | static hashval_t hash (const constexpr_fundef *); |
139 | static bool equal (const constexpr_fundef *, const constexpr_fundef *); | |
2d76680f PC |
140 | }; |
141 | ||
142 | /* This table holds all constexpr function definitions seen in | |
143 | the current translation unit. */ | |
144 | ||
145 | static GTY (()) hash_table<constexpr_fundef_hasher> *constexpr_fundef_table; | |
146 | ||
147 | /* Utility function used for managing the constexpr function table. | |
148 | Return true if the entries pointed to by P and Q are for the | |
149 | same constexpr function. */ | |
150 | ||
151 | inline bool | |
bfc139e2 NS |
152 | constexpr_fundef_hasher::equal (const constexpr_fundef *lhs, |
153 | const constexpr_fundef *rhs) | |
2d76680f PC |
154 | { |
155 | return lhs->decl == rhs->decl; | |
156 | } | |
157 | ||
158 | /* Utility function used for managing the constexpr function table. | |
159 | Return a hash value for the entry pointed to by Q. */ | |
160 | ||
161 | inline hashval_t | |
bfc139e2 | 162 | constexpr_fundef_hasher::hash (const constexpr_fundef *fundef) |
2d76680f PC |
163 | { |
164 | return DECL_UID (fundef->decl); | |
165 | } | |
166 | ||
167 | /* Return a previously saved definition of function FUN. */ | |
168 | ||
bfc139e2 | 169 | constexpr_fundef * |
2d76680f PC |
170 | retrieve_constexpr_fundef (tree fun) |
171 | { | |
2d76680f PC |
172 | if (constexpr_fundef_table == NULL) |
173 | return NULL; | |
174 | ||
bfc139e2 | 175 | constexpr_fundef fundef = { fun, NULL_TREE, NULL_TREE, NULL_TREE }; |
2d76680f PC |
176 | return constexpr_fundef_table->find (&fundef); |
177 | } | |
178 | ||
179 | /* Check whether the parameter and return types of FUN are valid for a | |
180 | constexpr function, and complain if COMPLAIN. */ | |
181 | ||
98e5a19a | 182 | bool |
2d76680f PC |
183 | is_valid_constexpr_fn (tree fun, bool complain) |
184 | { | |
185 | bool ret = true; | |
186 | ||
31f7f784 | 187 | if (DECL_INHERITED_CTOR (fun) |
2d76680f PC |
188 | && TREE_CODE (fun) == TEMPLATE_DECL) |
189 | { | |
190 | ret = false; | |
191 | if (complain) | |
84fa214d | 192 | error ("inherited constructor %qD is not %<constexpr%>", |
31f7f784 | 193 | DECL_INHERITED_CTOR (fun)); |
2d76680f PC |
194 | } |
195 | else | |
196 | { | |
197 | for (tree parm = FUNCTION_FIRST_USER_PARM (fun); | |
198 | parm != NULL_TREE; parm = TREE_CHAIN (parm)) | |
199 | if (!literal_type_p (TREE_TYPE (parm))) | |
200 | { | |
201 | ret = false; | |
202 | if (complain) | |
203 | { | |
097f82ec | 204 | auto_diagnostic_group d; |
84fa214d | 205 | error ("invalid type for parameter %d of %<constexpr%> " |
2d76680f PC |
206 | "function %q+#D", DECL_PARM_INDEX (parm), fun); |
207 | explain_non_literal_class (TREE_TYPE (parm)); | |
208 | } | |
209 | } | |
210 | } | |
211 | ||
e1bea341 JM |
212 | if (LAMBDA_TYPE_P (CP_DECL_CONTEXT (fun)) && cxx_dialect < cxx17) |
213 | { | |
214 | ret = false; | |
215 | if (complain) | |
216 | inform (DECL_SOURCE_LOCATION (fun), | |
84fa214d | 217 | "lambdas are implicitly %<constexpr%> only in C++17 and later"); |
e1bea341 JM |
218 | } |
219 | else if (!DECL_CONSTRUCTOR_P (fun)) | |
2d76680f PC |
220 | { |
221 | tree rettype = TREE_TYPE (TREE_TYPE (fun)); | |
222 | if (!literal_type_p (rettype)) | |
223 | { | |
224 | ret = false; | |
225 | if (complain) | |
226 | { | |
097f82ec | 227 | auto_diagnostic_group d; |
84fa214d | 228 | error ("invalid return type %qT of %<constexpr%> function %q+D", |
2d76680f PC |
229 | rettype, fun); |
230 | explain_non_literal_class (rettype); | |
231 | } | |
232 | } | |
233 | ||
54069e59 JM |
234 | /* C++14 DR 1684 removed this restriction. */ |
235 | if (cxx_dialect < cxx14 | |
236 | && DECL_NONSTATIC_MEMBER_FUNCTION_P (fun) | |
2d76680f PC |
237 | && !CLASSTYPE_LITERAL_P (DECL_CONTEXT (fun))) |
238 | { | |
239 | ret = false; | |
097f82ec DM |
240 | if (complain) |
241 | { | |
242 | auto_diagnostic_group d; | |
243 | if (pedwarn (DECL_SOURCE_LOCATION (fun), OPT_Wpedantic, | |
244 | "enclosing class of %<constexpr%> non-static" | |
245 | " member function %q+#D is not a literal type", | |
246 | fun)) | |
247 | explain_non_literal_class (DECL_CONTEXT (fun)); | |
248 | } | |
2d76680f PC |
249 | } |
250 | } | |
251 | else if (CLASSTYPE_VBASECLASSES (DECL_CONTEXT (fun))) | |
252 | { | |
253 | ret = false; | |
254 | if (complain) | |
255 | error ("%q#T has virtual base classes", DECL_CONTEXT (fun)); | |
256 | } | |
257 | ||
258 | return ret; | |
259 | } | |
260 | ||
261 | /* Subroutine of build_data_member_initialization. MEMBER is a COMPONENT_REF | |
262 | for a member of an anonymous aggregate, INIT is the initializer for that | |
263 | member, and VEC_OUTER is the vector of constructor elements for the class | |
264 | whose constructor we are processing. Add the initializer to the vector | |
265 | and return true to indicate success. */ | |
266 | ||
267 | static bool | |
268 | build_anon_member_initialization (tree member, tree init, | |
269 | vec<constructor_elt, va_gc> **vec_outer) | |
270 | { | |
271 | /* MEMBER presents the relevant fields from the inside out, but we need | |
272 | to build up the initializer from the outside in so that we can reuse | |
273 | previously built CONSTRUCTORs if this is, say, the second field in an | |
274 | anonymous struct. So we use a vec as a stack. */ | |
275 | auto_vec<tree, 2> fields; | |
276 | do | |
277 | { | |
278 | fields.safe_push (TREE_OPERAND (member, 1)); | |
279 | member = TREE_OPERAND (member, 0); | |
280 | } | |
281 | while (ANON_AGGR_TYPE_P (TREE_TYPE (member)) | |
282 | && TREE_CODE (member) == COMPONENT_REF); | |
283 | ||
284 | /* VEC has the constructor elements vector for the context of FIELD. | |
285 | If FIELD is an anonymous aggregate, we will push inside it. */ | |
286 | vec<constructor_elt, va_gc> **vec = vec_outer; | |
287 | tree field; | |
288 | while (field = fields.pop(), | |
289 | ANON_AGGR_TYPE_P (TREE_TYPE (field))) | |
290 | { | |
291 | tree ctor; | |
292 | /* If there is already an outer constructor entry for the anonymous | |
293 | aggregate FIELD, use it; otherwise, insert one. */ | |
294 | if (vec_safe_is_empty (*vec) | |
295 | || (*vec)->last().index != field) | |
296 | { | |
297 | ctor = build_constructor (TREE_TYPE (field), NULL); | |
298 | CONSTRUCTOR_APPEND_ELT (*vec, field, ctor); | |
299 | } | |
300 | else | |
301 | ctor = (*vec)->last().value; | |
302 | vec = &CONSTRUCTOR_ELTS (ctor); | |
303 | } | |
304 | ||
305 | /* Now we're at the innermost field, the one that isn't an anonymous | |
306 | aggregate. Add its initializer to the CONSTRUCTOR and we're done. */ | |
307 | gcc_assert (fields.is_empty()); | |
308 | CONSTRUCTOR_APPEND_ELT (*vec, field, init); | |
309 | ||
310 | return true; | |
311 | } | |
312 | ||
313 | /* Subroutine of build_constexpr_constructor_member_initializers. | |
314 | The expression tree T represents a data member initialization | |
315 | in a (constexpr) constructor definition. Build a pairing of | |
316 | the data member with its initializer, and prepend that pair | |
317 | to the existing initialization pair INITS. */ | |
318 | ||
319 | static bool | |
320 | build_data_member_initialization (tree t, vec<constructor_elt, va_gc> **vec) | |
321 | { | |
322 | tree member, init; | |
323 | if (TREE_CODE (t) == CLEANUP_POINT_EXPR) | |
324 | t = TREE_OPERAND (t, 0); | |
325 | if (TREE_CODE (t) == EXPR_STMT) | |
326 | t = TREE_OPERAND (t, 0); | |
327 | if (t == error_mark_node) | |
328 | return false; | |
329 | if (TREE_CODE (t) == STATEMENT_LIST) | |
330 | { | |
331 | tree_stmt_iterator i; | |
332 | for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i)) | |
333 | { | |
334 | if (! build_data_member_initialization (tsi_stmt (i), vec)) | |
335 | return false; | |
336 | } | |
337 | return true; | |
338 | } | |
339 | if (TREE_CODE (t) == CLEANUP_STMT) | |
340 | { | |
341 | /* We can't see a CLEANUP_STMT in a constructor for a literal class, | |
342 | but we can in a constexpr constructor for a non-literal class. Just | |
343 | ignore it; either all the initialization will be constant, in which | |
344 | case the cleanup can't run, or it can't be constexpr. | |
345 | Still recurse into CLEANUP_BODY. */ | |
346 | return build_data_member_initialization (CLEANUP_BODY (t), vec); | |
347 | } | |
348 | if (TREE_CODE (t) == CONVERT_EXPR) | |
349 | t = TREE_OPERAND (t, 0); | |
350 | if (TREE_CODE (t) == INIT_EXPR | |
60813a46 JM |
351 | /* vptr initialization shows up as a MODIFY_EXPR. In C++14 we only |
352 | use what this function builds for cx_check_missing_mem_inits, and | |
353 | assignment in the ctor body doesn't count. */ | |
354 | || (cxx_dialect < cxx14 && TREE_CODE (t) == MODIFY_EXPR)) | |
2d76680f PC |
355 | { |
356 | member = TREE_OPERAND (t, 0); | |
357 | init = break_out_target_exprs (TREE_OPERAND (t, 1)); | |
358 | } | |
359 | else if (TREE_CODE (t) == CALL_EXPR) | |
360 | { | |
60813a46 JM |
361 | tree fn = get_callee_fndecl (t); |
362 | if (!fn || !DECL_CONSTRUCTOR_P (fn)) | |
363 | /* We're only interested in calls to subobject constructors. */ | |
364 | return true; | |
2d76680f PC |
365 | member = CALL_EXPR_ARG (t, 0); |
366 | /* We don't use build_cplus_new here because it complains about | |
367 | abstract bases. Leaving the call unwrapped means that it has the | |
368 | wrong type, but cxx_eval_constant_expression doesn't care. */ | |
369 | init = break_out_target_exprs (t); | |
370 | } | |
371 | else if (TREE_CODE (t) == BIND_EXPR) | |
372 | return build_data_member_initialization (BIND_EXPR_BODY (t), vec); | |
2d76680f | 373 | else |
60813a46 JM |
374 | /* Don't add anything else to the CONSTRUCTOR. */ |
375 | return true; | |
2d76680f PC |
376 | if (INDIRECT_REF_P (member)) |
377 | member = TREE_OPERAND (member, 0); | |
378 | if (TREE_CODE (member) == NOP_EXPR) | |
379 | { | |
380 | tree op = member; | |
381 | STRIP_NOPS (op); | |
382 | if (TREE_CODE (op) == ADDR_EXPR) | |
383 | { | |
384 | gcc_assert (same_type_ignoring_top_level_qualifiers_p | |
385 | (TREE_TYPE (TREE_TYPE (op)), | |
386 | TREE_TYPE (TREE_TYPE (member)))); | |
387 | /* Initializing a cv-qualified member; we need to look through | |
388 | the const_cast. */ | |
389 | member = op; | |
390 | } | |
391 | else if (op == current_class_ptr | |
392 | && (same_type_ignoring_top_level_qualifiers_p | |
393 | (TREE_TYPE (TREE_TYPE (member)), | |
394 | current_class_type))) | |
395 | /* Delegating constructor. */ | |
396 | member = op; | |
397 | else | |
398 | { | |
399 | /* This is an initializer for an empty base; keep it for now so | |
400 | we can check it in cxx_eval_bare_aggregate. */ | |
401 | gcc_assert (is_empty_class (TREE_TYPE (TREE_TYPE (member)))); | |
402 | } | |
403 | } | |
404 | if (TREE_CODE (member) == ADDR_EXPR) | |
405 | member = TREE_OPERAND (member, 0); | |
406 | if (TREE_CODE (member) == COMPONENT_REF) | |
407 | { | |
408 | tree aggr = TREE_OPERAND (member, 0); | |
8cb7aaa1 JM |
409 | if (TREE_CODE (aggr) == VAR_DECL) |
410 | /* Initializing a local variable, don't add anything. */ | |
411 | return true; | |
2d76680f PC |
412 | if (TREE_CODE (aggr) != COMPONENT_REF) |
413 | /* Normal member initialization. */ | |
414 | member = TREE_OPERAND (member, 1); | |
415 | else if (ANON_AGGR_TYPE_P (TREE_TYPE (aggr))) | |
416 | /* Initializing a member of an anonymous union. */ | |
417 | return build_anon_member_initialization (member, init, vec); | |
418 | else | |
419 | /* We're initializing a vtable pointer in a base. Leave it as | |
420 | COMPONENT_REF so we remember the path to get to the vfield. */ | |
421 | gcc_assert (TREE_TYPE (member) == vtbl_ptr_type_node); | |
422 | } | |
423 | ||
49b5925f JM |
424 | /* Value-initialization can produce multiple initializers for the |
425 | same field; use the last one. */ | |
426 | if (!vec_safe_is_empty (*vec) && (*vec)->last().index == member) | |
427 | (*vec)->last().value = init; | |
428 | else | |
429 | CONSTRUCTOR_APPEND_ELT (*vec, member, init); | |
2d76680f PC |
430 | return true; |
431 | } | |
432 | ||
433 | /* Subroutine of check_constexpr_ctor_body_1 and constexpr_fn_retval. | |
434 | In C++11 mode checks that the TYPE_DECLs in the BIND_EXPR_VARS of a | |
435 | BIND_EXPR conform to 7.1.5/3/4 on typedef and alias declarations. */ | |
436 | ||
437 | static bool | |
438 | check_constexpr_bind_expr_vars (tree t) | |
439 | { | |
440 | gcc_assert (TREE_CODE (t) == BIND_EXPR); | |
441 | ||
2d76680f PC |
442 | for (tree var = BIND_EXPR_VARS (t); var; var = DECL_CHAIN (var)) |
443 | if (TREE_CODE (var) == TYPE_DECL | |
4414e22e PC |
444 | && DECL_IMPLICIT_TYPEDEF_P (var) |
445 | && !LAMBDA_TYPE_P (TREE_TYPE (var))) | |
2d76680f PC |
446 | return false; |
447 | return true; | |
448 | } | |
449 | ||
450 | /* Subroutine of check_constexpr_ctor_body. */ | |
451 | ||
452 | static bool | |
453 | check_constexpr_ctor_body_1 (tree last, tree list) | |
454 | { | |
455 | switch (TREE_CODE (list)) | |
456 | { | |
457 | case DECL_EXPR: | |
a0008434 MP |
458 | if (TREE_CODE (DECL_EXPR_DECL (list)) == USING_DECL |
459 | || TREE_CODE (DECL_EXPR_DECL (list)) == TYPE_DECL) | |
2d76680f | 460 | return true; |
2d76680f PC |
461 | return false; |
462 | ||
463 | case CLEANUP_POINT_EXPR: | |
464 | return check_constexpr_ctor_body (last, TREE_OPERAND (list, 0), | |
465 | /*complain=*/false); | |
466 | ||
467 | case BIND_EXPR: | |
468 | if (!check_constexpr_bind_expr_vars (list) | |
469 | || !check_constexpr_ctor_body (last, BIND_EXPR_BODY (list), | |
470 | /*complain=*/false)) | |
471 | return false; | |
472 | return true; | |
473 | ||
474 | case USING_STMT: | |
475 | case STATIC_ASSERT: | |
96a95ac1 | 476 | case DEBUG_BEGIN_STMT: |
2d76680f PC |
477 | return true; |
478 | ||
479 | default: | |
480 | return false; | |
481 | } | |
482 | } | |
483 | ||
484 | /* Make sure that there are no statements after LAST in the constructor | |
485 | body represented by LIST. */ | |
486 | ||
487 | bool | |
488 | check_constexpr_ctor_body (tree last, tree list, bool complain) | |
489 | { | |
60813a46 JM |
490 | /* C++14 doesn't require a constexpr ctor to have an empty body. */ |
491 | if (cxx_dialect >= cxx14) | |
492 | return true; | |
493 | ||
2d76680f PC |
494 | bool ok = true; |
495 | if (TREE_CODE (list) == STATEMENT_LIST) | |
496 | { | |
497 | tree_stmt_iterator i = tsi_last (list); | |
498 | for (; !tsi_end_p (i); tsi_prev (&i)) | |
499 | { | |
500 | tree t = tsi_stmt (i); | |
501 | if (t == last) | |
502 | break; | |
503 | if (!check_constexpr_ctor_body_1 (last, t)) | |
504 | { | |
505 | ok = false; | |
506 | break; | |
507 | } | |
508 | } | |
509 | } | |
510 | else if (list != last | |
511 | && !check_constexpr_ctor_body_1 (last, list)) | |
512 | ok = false; | |
513 | if (!ok) | |
514 | { | |
515 | if (complain) | |
84fa214d | 516 | error ("%<constexpr%> constructor does not have empty body"); |
2d76680f PC |
517 | DECL_DECLARED_CONSTEXPR_P (current_function_decl) = false; |
518 | } | |
519 | return ok; | |
520 | } | |
521 | ||
522 | /* V is a vector of constructor elements built up for the base and member | |
523 | initializers of a constructor for TYPE. They need to be in increasing | |
524 | offset order, which they might not be yet if TYPE has a primary base | |
525 | which is not first in the base-clause or a vptr and at least one base | |
526 | all of which are non-primary. */ | |
527 | ||
528 | static vec<constructor_elt, va_gc> * | |
529 | sort_constexpr_mem_initializers (tree type, vec<constructor_elt, va_gc> *v) | |
530 | { | |
531 | tree pri = CLASSTYPE_PRIMARY_BINFO (type); | |
532 | tree field_type; | |
533 | unsigned i; | |
534 | constructor_elt *ce; | |
535 | ||
536 | if (pri) | |
537 | field_type = BINFO_TYPE (pri); | |
538 | else if (TYPE_CONTAINS_VPTR_P (type)) | |
539 | field_type = vtbl_ptr_type_node; | |
540 | else | |
541 | return v; | |
542 | ||
543 | /* Find the element for the primary base or vptr and move it to the | |
544 | beginning of the vec. */ | |
545 | for (i = 0; vec_safe_iterate (v, i, &ce); ++i) | |
546 | if (TREE_TYPE (ce->index) == field_type) | |
547 | break; | |
548 | ||
549 | if (i > 0 && i < vec_safe_length (v)) | |
550 | { | |
551 | vec<constructor_elt, va_gc> &vref = *v; | |
552 | constructor_elt elt = vref[i]; | |
553 | for (; i > 0; --i) | |
554 | vref[i] = vref[i-1]; | |
555 | vref[0] = elt; | |
556 | } | |
557 | ||
558 | return v; | |
559 | } | |
560 | ||
561 | /* Build compile-time evalable representations of member-initializer list | |
562 | for a constexpr constructor. */ | |
563 | ||
564 | static tree | |
565 | build_constexpr_constructor_member_initializers (tree type, tree body) | |
566 | { | |
567 | vec<constructor_elt, va_gc> *vec = NULL; | |
568 | bool ok = true; | |
fa837fb6 JM |
569 | while (true) |
570 | switch (TREE_CODE (body)) | |
571 | { | |
572 | case MUST_NOT_THROW_EXPR: | |
573 | case EH_SPEC_BLOCK: | |
574 | body = TREE_OPERAND (body, 0); | |
575 | break; | |
576 | ||
577 | case STATEMENT_LIST: | |
578 | for (tree_stmt_iterator i = tsi_start (body); | |
579 | !tsi_end_p (i); tsi_next (&i)) | |
580 | { | |
581 | body = tsi_stmt (i); | |
582 | if (TREE_CODE (body) == BIND_EXPR) | |
583 | break; | |
584 | } | |
585 | break; | |
586 | ||
587 | case BIND_EXPR: | |
588 | body = BIND_EXPR_BODY (body); | |
589 | goto found; | |
590 | ||
591 | default: | |
592 | gcc_unreachable (); | |
58cc255c | 593 | } |
fa837fb6 | 594 | found: |
1259cb6d JJ |
595 | if (TREE_CODE (body) == TRY_BLOCK) |
596 | { | |
597 | body = TREE_OPERAND (body, 0); | |
598 | if (TREE_CODE (body) == BIND_EXPR) | |
599 | body = BIND_EXPR_BODY (body); | |
600 | } | |
2d76680f PC |
601 | if (TREE_CODE (body) == CLEANUP_POINT_EXPR) |
602 | { | |
603 | body = TREE_OPERAND (body, 0); | |
604 | if (TREE_CODE (body) == EXPR_STMT) | |
605 | body = TREE_OPERAND (body, 0); | |
606 | if (TREE_CODE (body) == INIT_EXPR | |
607 | && (same_type_ignoring_top_level_qualifiers_p | |
608 | (TREE_TYPE (TREE_OPERAND (body, 0)), | |
609 | current_class_type))) | |
610 | { | |
611 | /* Trivial copy. */ | |
612 | return TREE_OPERAND (body, 1); | |
613 | } | |
614 | ok = build_data_member_initialization (body, &vec); | |
615 | } | |
616 | else if (TREE_CODE (body) == STATEMENT_LIST) | |
617 | { | |
618 | tree_stmt_iterator i; | |
619 | for (i = tsi_start (body); !tsi_end_p (i); tsi_next (&i)) | |
620 | { | |
621 | ok = build_data_member_initialization (tsi_stmt (i), &vec); | |
622 | if (!ok) | |
623 | break; | |
624 | } | |
625 | } | |
2d76680f PC |
626 | else if (EXPR_P (body)) |
627 | ok = build_data_member_initialization (body, &vec); | |
628 | else | |
629 | gcc_assert (errorcount > 0); | |
630 | if (ok) | |
631 | { | |
632 | if (vec_safe_length (vec) > 0) | |
633 | { | |
634 | /* In a delegating constructor, return the target. */ | |
635 | constructor_elt *ce = &(*vec)[0]; | |
636 | if (ce->index == current_class_ptr) | |
637 | { | |
638 | body = ce->value; | |
639 | vec_free (vec); | |
640 | return body; | |
641 | } | |
642 | } | |
643 | vec = sort_constexpr_mem_initializers (type, vec); | |
644 | return build_constructor (type, vec); | |
645 | } | |
646 | else | |
647 | return error_mark_node; | |
648 | } | |
649 | ||
1b6fa695 ML |
650 | /* We have an expression tree T that represents a call, either CALL_EXPR |
651 | or AGGR_INIT_EXPR. If the call is lexically to a named function, | |
652 | retrun the _DECL for that function. */ | |
653 | ||
654 | static tree | |
655 | get_function_named_in_call (tree t) | |
656 | { | |
657 | tree fun = cp_get_callee (t); | |
658 | if (fun && TREE_CODE (fun) == ADDR_EXPR | |
659 | && TREE_CODE (TREE_OPERAND (fun, 0)) == FUNCTION_DECL) | |
660 | fun = TREE_OPERAND (fun, 0); | |
661 | return fun; | |
662 | } | |
663 | ||
bfc139e2 | 664 | /* Subroutine of check_constexpr_fundef. BODY is the body of a function |
2d76680f PC |
665 | declared to be constexpr, or a sub-statement thereof. Returns the |
666 | return value if suitable, error_mark_node for a statement not allowed in | |
667 | a constexpr function, or NULL_TREE if no return value was found. */ | |
668 | ||
5afef8b1 | 669 | tree |
2d76680f PC |
670 | constexpr_fn_retval (tree body) |
671 | { | |
672 | switch (TREE_CODE (body)) | |
673 | { | |
674 | case STATEMENT_LIST: | |
675 | { | |
676 | tree_stmt_iterator i; | |
677 | tree expr = NULL_TREE; | |
678 | for (i = tsi_start (body); !tsi_end_p (i); tsi_next (&i)) | |
679 | { | |
680 | tree s = constexpr_fn_retval (tsi_stmt (i)); | |
681 | if (s == error_mark_node) | |
682 | return error_mark_node; | |
683 | else if (s == NULL_TREE) | |
684 | /* Keep iterating. */; | |
685 | else if (expr) | |
686 | /* Multiple return statements. */ | |
687 | return error_mark_node; | |
688 | else | |
689 | expr = s; | |
690 | } | |
691 | return expr; | |
692 | } | |
693 | ||
694 | case RETURN_EXPR: | |
695 | return break_out_target_exprs (TREE_OPERAND (body, 0)); | |
696 | ||
697 | case DECL_EXPR: | |
0162cb3b PC |
698 | { |
699 | tree decl = DECL_EXPR_DECL (body); | |
700 | if (TREE_CODE (decl) == USING_DECL | |
701 | /* Accept __func__, __FUNCTION__, and __PRETTY_FUNCTION__. */ | |
702 | || DECL_ARTIFICIAL (decl)) | |
703 | return NULL_TREE; | |
704 | return error_mark_node; | |
705 | } | |
2d76680f PC |
706 | |
707 | case CLEANUP_POINT_EXPR: | |
708 | return constexpr_fn_retval (TREE_OPERAND (body, 0)); | |
709 | ||
710 | case BIND_EXPR: | |
711 | if (!check_constexpr_bind_expr_vars (body)) | |
712 | return error_mark_node; | |
713 | return constexpr_fn_retval (BIND_EXPR_BODY (body)); | |
714 | ||
715 | case USING_STMT: | |
96a95ac1 | 716 | case DEBUG_BEGIN_STMT: |
2d76680f PC |
717 | return NULL_TREE; |
718 | ||
1b6fa695 ML |
719 | case CALL_EXPR: |
720 | { | |
721 | tree fun = get_function_named_in_call (body); | |
722 | if (fun != NULL_TREE | |
3d78e008 | 723 | && fndecl_built_in_p (fun, BUILT_IN_UNREACHABLE)) |
1b6fa695 ML |
724 | return NULL_TREE; |
725 | } | |
726 | /* Fallthru. */ | |
727 | ||
2d76680f PC |
728 | default: |
729 | return error_mark_node; | |
730 | } | |
731 | } | |
732 | ||
bfc139e2 | 733 | /* Subroutine of check_constexpr_fundef. BODY is the DECL_SAVED_TREE of |
2d76680f PC |
734 | FUN; do the necessary transformations to turn it into a single expression |
735 | that we can store in the hash table. */ | |
736 | ||
737 | static tree | |
738 | massage_constexpr_body (tree fun, tree body) | |
739 | { | |
740 | if (DECL_CONSTRUCTOR_P (fun)) | |
741 | body = build_constexpr_constructor_member_initializers | |
742 | (DECL_CONTEXT (fun), body); | |
60813a46 | 743 | else if (cxx_dialect < cxx14) |
2d76680f PC |
744 | { |
745 | if (TREE_CODE (body) == EH_SPEC_BLOCK) | |
746 | body = EH_SPEC_STMTS (body); | |
747 | if (TREE_CODE (body) == MUST_NOT_THROW_EXPR) | |
748 | body = TREE_OPERAND (body, 0); | |
749 | body = constexpr_fn_retval (body); | |
750 | } | |
751 | return body; | |
752 | } | |
753 | ||
3e4b91f2 NS |
754 | /* CTYPE is a type constructed from BODY. Return true if some |
755 | bases/fields are uninitialized, and complain if COMPLAIN. */ | |
2d76680f PC |
756 | |
757 | static bool | |
3e4b91f2 | 758 | cx_check_missing_mem_inits (tree ctype, tree body, bool complain) |
2d76680f | 759 | { |
7906797e | 760 | /* We allow uninitialized bases/fields in C++20. */ |
b04445d4 | 761 | if (cxx_dialect >= cxx20) |
7906797e MP |
762 | return false; |
763 | ||
3e4b91f2 NS |
764 | unsigned nelts = 0; |
765 | ||
766 | if (body) | |
767 | { | |
768 | if (TREE_CODE (body) != CONSTRUCTOR) | |
769 | return false; | |
770 | nelts = CONSTRUCTOR_NELTS (body); | |
771 | } | |
772 | tree field = TYPE_FIELDS (ctype); | |
2d76680f PC |
773 | |
774 | if (TREE_CODE (ctype) == UNION_TYPE) | |
775 | { | |
776 | if (nelts == 0 && next_initializable_field (field)) | |
777 | { | |
778 | if (complain) | |
779 | error ("%<constexpr%> constructor for union %qT must " | |
780 | "initialize exactly one non-static data member", ctype); | |
781 | return true; | |
782 | } | |
783 | return false; | |
784 | } | |
785 | ||
3e4b91f2 NS |
786 | /* Iterate over the CONSTRUCTOR, checking any missing fields don't |
787 | need an explicit initialization. */ | |
788 | bool bad = false; | |
789 | for (unsigned i = 0; i <= nelts; ++i) | |
2d76680f | 790 | { |
3e4b91f2 NS |
791 | tree index = NULL_TREE; |
792 | if (i < nelts) | |
2d76680f PC |
793 | { |
794 | index = CONSTRUCTOR_ELT (body, i)->index; | |
795 | /* Skip base and vtable inits. */ | |
796 | if (TREE_CODE (index) != FIELD_DECL | |
797 | || DECL_ARTIFICIAL (index)) | |
798 | continue; | |
799 | } | |
3e4b91f2 | 800 | |
2d76680f PC |
801 | for (; field != index; field = DECL_CHAIN (field)) |
802 | { | |
803 | tree ftype; | |
3e4b91f2 NS |
804 | if (TREE_CODE (field) != FIELD_DECL) |
805 | continue; | |
7c30b12a | 806 | if (DECL_UNNAMED_BIT_FIELD (field)) |
2d76680f | 807 | continue; |
3e4b91f2 NS |
808 | if (DECL_ARTIFICIAL (field)) |
809 | continue; | |
810 | if (ANON_AGGR_TYPE_P (TREE_TYPE (field))) | |
811 | { | |
7906797e | 812 | /* Recurse to check the anonymous aggregate member. */ |
3e4b91f2 NS |
813 | bad |= cx_check_missing_mem_inits |
814 | (TREE_TYPE (field), NULL_TREE, complain); | |
815 | if (bad && !complain) | |
816 | return true; | |
817 | continue; | |
818 | } | |
a1c9c9ff JM |
819 | ftype = TREE_TYPE (field); |
820 | if (!ftype || !TYPE_P (ftype) || !COMPLETE_TYPE_P (ftype)) | |
821 | /* A flexible array can't be intialized here, so don't complain | |
822 | that it isn't. */ | |
823 | continue; | |
6876b269 JM |
824 | if (DECL_SIZE (field) && integer_zerop (DECL_SIZE (field))) |
825 | /* An empty field doesn't need an initializer. */ | |
826 | continue; | |
a1c9c9ff | 827 | ftype = strip_array_types (ftype); |
2d76680f PC |
828 | if (type_has_constexpr_default_constructor (ftype)) |
829 | { | |
830 | /* It's OK to skip a member with a trivial constexpr ctor. | |
831 | A constexpr ctor that isn't trivial should have been | |
832 | added in by now. */ | |
833 | gcc_checking_assert (!TYPE_HAS_COMPLEX_DFLT (ftype) | |
834 | || errorcount != 0); | |
835 | continue; | |
836 | } | |
837 | if (!complain) | |
838 | return true; | |
097f82ec | 839 | auto_diagnostic_group d; |
b8cd3996 JM |
840 | error ("member %qD must be initialized by mem-initializer " |
841 | "in %<constexpr%> constructor", field); | |
842 | inform (DECL_SOURCE_LOCATION (field), "declared here"); | |
2d76680f PC |
843 | bad = true; |
844 | } | |
845 | if (field == NULL_TREE) | |
846 | break; | |
3e4b91f2 NS |
847 | |
848 | if (ANON_AGGR_TYPE_P (TREE_TYPE (index))) | |
849 | { | |
850 | /* Check the anonymous aggregate initializer is valid. */ | |
851 | bad |= cx_check_missing_mem_inits | |
852 | (TREE_TYPE (index), CONSTRUCTOR_ELT (body, i)->value, complain); | |
853 | if (bad && !complain) | |
854 | return true; | |
855 | } | |
2d76680f PC |
856 | field = DECL_CHAIN (field); |
857 | } | |
858 | ||
859 | return bad; | |
860 | } | |
861 | ||
862 | /* We are processing the definition of the constexpr function FUN. | |
bfc139e2 NS |
863 | Check that its body fulfills the apropriate requirements and |
864 | enter it in the constexpr function definition table. */ | |
2d76680f | 865 | |
bfc139e2 NS |
866 | void |
867 | maybe_save_constexpr_fundef (tree fun) | |
2d76680f | 868 | { |
bfc139e2 NS |
869 | if (processing_template_decl |
870 | || !DECL_DECLARED_CONSTEXPR_P (fun) | |
871 | || cp_function_chain->invalid_constexpr | |
872 | || DECL_CLONED_FUNCTION_P (fun)) | |
873 | return; | |
2d76680f PC |
874 | |
875 | if (!is_valid_constexpr_fn (fun, !DECL_GENERATED_P (fun))) | |
bfc139e2 | 876 | return; |
2d76680f | 877 | |
bfc139e2 | 878 | tree massaged = massage_constexpr_body (fun, DECL_SAVED_TREE (fun)); |
ca30abcd | 879 | if (massaged == NULL_TREE || massaged == error_mark_node) |
2d76680f PC |
880 | { |
881 | if (!DECL_CONSTRUCTOR_P (fun)) | |
84fa214d ML |
882 | error ("body of %<constexpr%> function %qD not a return-statement", |
883 | fun); | |
bfc139e2 | 884 | return; |
2d76680f PC |
885 | } |
886 | ||
4f05d85a JM |
887 | bool potential = potential_rvalue_constant_expression (massaged); |
888 | if (!potential && !DECL_GENERATED_P (fun)) | |
889 | require_potential_rvalue_constant_expression (massaged); | |
2d76680f PC |
890 | |
891 | if (DECL_CONSTRUCTOR_P (fun) | |
3e4b91f2 NS |
892 | && cx_check_missing_mem_inits (DECL_CONTEXT (fun), |
893 | massaged, !DECL_GENERATED_P (fun))) | |
4f05d85a JM |
894 | potential = false; |
895 | ||
896 | if (!potential && !DECL_GENERATED_P (fun)) | |
bfc139e2 | 897 | return; |
2d76680f | 898 | |
bfc139e2 | 899 | constexpr_fundef entry = {fun, NULL_TREE, NULL_TREE, NULL_TREE}; |
43574e4f | 900 | bool clear_ctx = false; |
43574e4f JJ |
901 | if (DECL_RESULT (fun) && DECL_CONTEXT (DECL_RESULT (fun)) == NULL_TREE) |
902 | { | |
903 | clear_ctx = true; | |
904 | DECL_CONTEXT (DECL_RESULT (fun)) = fun; | |
905 | } | |
bfc139e2 NS |
906 | tree saved_fn = current_function_decl; |
907 | current_function_decl = fun; | |
908 | entry.body = copy_fn (entry.decl, entry.parms, entry.result); | |
43574e4f | 909 | current_function_decl = saved_fn; |
43574e4f | 910 | if (clear_ctx) |
bfc139e2 | 911 | DECL_CONTEXT (DECL_RESULT (entry.decl)) = NULL_TREE; |
4f05d85a JM |
912 | if (!potential) |
913 | /* For a template instantiation, we want to remember the pre-generic body | |
914 | for explain_invalid_constexpr_fn, but do tell cxx_eval_call_expression | |
915 | that it doesn't need to bother trying to expand the function. */ | |
916 | entry.result = error_mark_node; | |
917 | ||
bfc139e2 NS |
918 | register_constexpr_fundef (entry); |
919 | } | |
920 | ||
921 | /* BODY is a validated and massaged definition of a constexpr | |
922 | function. Register it in the hash table. */ | |
923 | ||
924 | void | |
925 | register_constexpr_fundef (const constexpr_fundef &value) | |
926 | { | |
927 | /* Create the constexpr function table if necessary. */ | |
928 | if (constexpr_fundef_table == NULL) | |
929 | constexpr_fundef_table | |
930 | = hash_table<constexpr_fundef_hasher>::create_ggc (101); | |
931 | ||
932 | constexpr_fundef **slot = constexpr_fundef_table->find_slot | |
933 | (const_cast<constexpr_fundef *> (&value), INSERT); | |
934 | ||
2d76680f PC |
935 | gcc_assert (*slot == NULL); |
936 | *slot = ggc_alloc<constexpr_fundef> (); | |
bfc139e2 | 937 | **slot = value; |
2d76680f PC |
938 | } |
939 | ||
940 | /* FUN is a non-constexpr function called in a context that requires a | |
941 | constant expression. If it comes from a constexpr template, explain why | |
942 | the instantiation isn't constexpr. */ | |
943 | ||
944 | void | |
945 | explain_invalid_constexpr_fn (tree fun) | |
946 | { | |
947 | static hash_set<tree> *diagnosed; | |
948 | tree body; | |
949 | location_t save_loc; | |
98e5a19a | 950 | /* Only diagnose defaulted functions, lambdas, or instantiations. */ |
2d76680f | 951 | if (!DECL_DEFAULTED_FN (fun) |
98e5a19a | 952 | && !LAMBDA_TYPE_P (CP_DECL_CONTEXT (fun)) |
2d76680f | 953 | && !is_instantiation_of_constexpr (fun)) |
f22f817c JM |
954 | { |
955 | inform (DECL_SOURCE_LOCATION (fun), "%qD declared here", fun); | |
956 | return; | |
957 | } | |
2d76680f PC |
958 | if (diagnosed == NULL) |
959 | diagnosed = new hash_set<tree>; | |
960 | if (diagnosed->add (fun)) | |
961 | /* Already explained. */ | |
962 | return; | |
963 | ||
964 | save_loc = input_location; | |
98e5a19a JM |
965 | if (!lambda_static_thunk_p (fun)) |
966 | { | |
967 | /* Diagnostics should completely ignore the static thunk, so leave | |
968 | input_location set to our caller's location. */ | |
969 | input_location = DECL_SOURCE_LOCATION (fun); | |
970 | inform (input_location, | |
84fa214d | 971 | "%qD is not usable as a %<constexpr%> function because:", fun); |
98e5a19a | 972 | } |
2d76680f PC |
973 | /* First check the declaration. */ |
974 | if (is_valid_constexpr_fn (fun, true)) | |
975 | { | |
976 | /* Then if it's OK, the body. */ | |
98e5a19a | 977 | if (!DECL_DECLARED_CONSTEXPR_P (fun) |
4f05d85a | 978 | && DECL_DEFAULTED_FN (fun)) |
2d76680f PC |
979 | explain_implicit_non_constexpr (fun); |
980 | else | |
981 | { | |
4f05d85a JM |
982 | if (constexpr_fundef *fd = retrieve_constexpr_fundef (fun)) |
983 | body = fd->body; | |
984 | else | |
985 | body = DECL_SAVED_TREE (fun); | |
986 | body = massage_constexpr_body (fun, body); | |
2d76680f PC |
987 | require_potential_rvalue_constant_expression (body); |
988 | if (DECL_CONSTRUCTOR_P (fun)) | |
3e4b91f2 | 989 | cx_check_missing_mem_inits (DECL_CONTEXT (fun), body, true); |
2d76680f PC |
990 | } |
991 | } | |
992 | input_location = save_loc; | |
993 | } | |
994 | ||
995 | /* Objects of this type represent calls to constexpr functions | |
996 | along with the bindings of parameters to their arguments, for | |
997 | the purpose of compile time evaluation. */ | |
998 | ||
999 | struct GTY((for_user)) constexpr_call { | |
1000 | /* Description of the constexpr function definition. */ | |
1001 | constexpr_fundef *fundef; | |
3c961dc7 | 1002 | /* Parameter bindings environment. A TREE_VEC of arguments. */ |
2d76680f PC |
1003 | tree bindings; |
1004 | /* Result of the call. | |
1005 | NULL means the call is being evaluated. | |
1006 | error_mark_node means that the evaluation was erroneous; | |
1007 | otherwise, the actuall value of the call. */ | |
1008 | tree result; | |
1009 | /* The hash of this call; we remember it here to avoid having to | |
1010 | recalculate it when expanding the hash table. */ | |
1011 | hashval_t hash; | |
cce3ae91 | 1012 | /* Whether __builtin_is_constant_evaluated() should evaluate to true. */ |
13de99bc | 1013 | bool manifestly_const_eval; |
2d76680f PC |
1014 | }; |
1015 | ||
ca752f39 | 1016 | struct constexpr_call_hasher : ggc_ptr_hash<constexpr_call> |
2d76680f PC |
1017 | { |
1018 | static hashval_t hash (constexpr_call *); | |
1019 | static bool equal (constexpr_call *, constexpr_call *); | |
3e605b20 JM |
1020 | }; |
1021 | ||
4b390698 JJ |
1022 | enum constexpr_switch_state { |
1023 | /* Used when processing a switch for the first time by cxx_eval_switch_expr | |
1024 | and default: label for that switch has not been seen yet. */ | |
1025 | css_default_not_seen, | |
1026 | /* Used when processing a switch for the first time by cxx_eval_switch_expr | |
1027 | and default: label for that switch has been seen already. */ | |
1028 | css_default_seen, | |
1029 | /* Used when processing a switch for the second time by | |
1030 | cxx_eval_switch_expr, where default: label should match. */ | |
1031 | css_default_processing | |
1032 | }; | |
1033 | ||
8e007055 JJ |
1034 | /* The constexpr expansion context part which needs one instance per |
1035 | cxx_eval_outermost_constant_expr invocation. VALUES is a map of values of | |
1036 | variables initialized within the expression. */ | |
1037 | ||
1038 | struct constexpr_global_ctx { | |
1039 | /* Values for any temporaries or local variables within the | |
1040 | constant-expression. */ | |
1041 | hash_map<tree,tree> values; | |
1042 | /* Number of cxx_eval_constant_expression calls (except skipped ones, | |
1043 | on simple constants or location wrappers) encountered during current | |
1044 | cxx_eval_outermost_constant_expr call. */ | |
1045 | HOST_WIDE_INT constexpr_ops_count; | |
1046 | /* Heap VAR_DECLs created during the evaluation of the outermost constant | |
1047 | expression. */ | |
1048 | auto_vec<tree, 16> heap_vars; | |
ee1de08d JJ |
1049 | /* Cleanups that need to be evaluated at the end of CLEANUP_POINT_EXPR. */ |
1050 | vec<tree> *cleanups; | |
f74f6092 JJ |
1051 | /* Number of heap VAR_DECL deallocations. */ |
1052 | unsigned heap_dealloc_count; | |
8e007055 | 1053 | /* Constructor. */ |
f74f6092 JJ |
1054 | constexpr_global_ctx () |
1055 | : constexpr_ops_count (0), cleanups (NULL), heap_dealloc_count (0) {} | |
8e007055 JJ |
1056 | }; |
1057 | ||
3e605b20 JM |
1058 | /* The constexpr expansion context. CALL is the current function |
1059 | expansion, CTOR is the current aggregate initializer, OBJECT is the | |
8e007055 | 1060 | object being initialized by CTOR, either a VAR_DECL or a _REF. */ |
3e605b20 JM |
1061 | |
1062 | struct constexpr_ctx { | |
8e007055 JJ |
1063 | /* The part of the context that needs to be unique to the whole |
1064 | cxx_eval_outermost_constant_expr invocation. */ | |
1065 | constexpr_global_ctx *global; | |
13f649f6 | 1066 | /* The innermost call we're evaluating. */ |
3e605b20 | 1067 | constexpr_call *call; |
ee1de08d JJ |
1068 | /* SAVE_EXPRs and TARGET_EXPR_SLOT vars of TARGET_EXPRs that we've seen |
1069 | within the current LOOP_EXPR. NULL if we aren't inside a loop. */ | |
0ee28590 | 1070 | vec<tree> *save_exprs; |
13f649f6 JM |
1071 | /* The CONSTRUCTOR we're currently building up for an aggregate |
1072 | initializer. */ | |
3e605b20 | 1073 | tree ctor; |
13f649f6 | 1074 | /* The object we're building the CONSTRUCTOR for. */ |
3e605b20 | 1075 | tree object; |
4b390698 JJ |
1076 | /* If inside SWITCH_EXPR. */ |
1077 | constexpr_switch_state *css_state; | |
49a86fce PP |
1078 | /* The aggregate initialization context inside which this one is nested. This |
1079 | is used by lookup_placeholder to resolve PLACEHOLDER_EXPRs. */ | |
1080 | const constexpr_ctx *parent; | |
a15ffa22 | 1081 | |
aaa26bf4 JM |
1082 | /* Whether we should error on a non-constant expression or fail quietly. |
1083 | This flag needs to be here, but some of the others could move to global | |
1084 | if they get larger than a word. */ | |
2b3ab879 | 1085 | bool quiet; |
13f649f6 JM |
1086 | /* Whether we are strictly conforming to constant expression rules or |
1087 | trying harder to get a constant value. */ | |
69eb4fde | 1088 | bool strict; |
e4082611 | 1089 | /* Whether __builtin_is_constant_evaluated () should be true. */ |
13de99bc | 1090 | bool manifestly_const_eval; |
3e605b20 | 1091 | }; |
2d76680f | 1092 | |
f65a3299 PP |
1093 | /* This internal flag controls whether we should avoid doing anything during |
1094 | constexpr evaluation that would cause extra DECL_UID generation, such as | |
1095 | template instantiation and function body copying. */ | |
1096 | ||
1097 | static bool uid_sensitive_constexpr_evaluation_value; | |
1098 | ||
1099 | /* An internal counter that keeps track of the number of times | |
1100 | uid_sensitive_constexpr_evaluation_p returned true. */ | |
1101 | ||
1102 | static unsigned uid_sensitive_constexpr_evaluation_true_counter; | |
1103 | ||
1104 | /* The accessor for uid_sensitive_constexpr_evaluation_value which also | |
1105 | increments the corresponding counter. */ | |
1106 | ||
1107 | static bool | |
1108 | uid_sensitive_constexpr_evaluation_p () | |
1109 | { | |
1110 | if (uid_sensitive_constexpr_evaluation_value) | |
1111 | { | |
1112 | ++uid_sensitive_constexpr_evaluation_true_counter; | |
1113 | return true; | |
1114 | } | |
1115 | else | |
1116 | return false; | |
1117 | } | |
1118 | ||
1119 | /* The default constructor for uid_sensitive_constexpr_evaluation_sentinel | |
1120 | enables the internal flag for uid_sensitive_constexpr_evaluation_p | |
1121 | during the lifetime of the sentinel object. Upon its destruction, the | |
1122 | previous value of uid_sensitive_constexpr_evaluation_p is restored. */ | |
1123 | ||
1124 | uid_sensitive_constexpr_evaluation_sentinel | |
1125 | ::uid_sensitive_constexpr_evaluation_sentinel () | |
1126 | : ovr (uid_sensitive_constexpr_evaluation_value, true) | |
1127 | { | |
1128 | } | |
1129 | ||
1130 | /* The default constructor for uid_sensitive_constexpr_evaluation_checker | |
1131 | records the current number of times that uid_sensitive_constexpr_evaluation_p | |
1132 | has been called and returned true. */ | |
1133 | ||
1134 | uid_sensitive_constexpr_evaluation_checker | |
1135 | ::uid_sensitive_constexpr_evaluation_checker () | |
1136 | : saved_counter (uid_sensitive_constexpr_evaluation_true_counter) | |
1137 | { | |
1138 | } | |
1139 | ||
1140 | /* Returns true iff uid_sensitive_constexpr_evaluation_p is true, and | |
1141 | some constexpr evaluation was restricted due to u_s_c_e_p being called | |
1142 | and returning true during the lifetime of this checker object. */ | |
1143 | ||
1144 | bool | |
1145 | uid_sensitive_constexpr_evaluation_checker::evaluation_restricted_p () const | |
1146 | { | |
1147 | return (uid_sensitive_constexpr_evaluation_value | |
1148 | && saved_counter != uid_sensitive_constexpr_evaluation_true_counter); | |
1149 | } | |
1150 | ||
1151 | ||
2d76680f PC |
1152 | /* A table of all constexpr calls that have been evaluated by the |
1153 | compiler in this translation unit. */ | |
1154 | ||
97f3003f | 1155 | static GTY (()) hash_table<constexpr_call_hasher> *constexpr_call_table; |
2d76680f | 1156 | |
3e605b20 | 1157 | static tree cxx_eval_constant_expression (const constexpr_ctx *, tree, |
5a804683 | 1158 | bool, bool *, bool *, tree * = NULL); |
2d76680f PC |
1159 | |
1160 | /* Compute a hash value for a constexpr call representation. */ | |
1161 | ||
1162 | inline hashval_t | |
1163 | constexpr_call_hasher::hash (constexpr_call *info) | |
1164 | { | |
1165 | return info->hash; | |
1166 | } | |
1167 | ||
1168 | /* Return true if the objects pointed to by P and Q represent calls | |
1169 | to the same constexpr function with the same arguments. | |
1170 | Otherwise, return false. */ | |
1171 | ||
1172 | bool | |
1173 | constexpr_call_hasher::equal (constexpr_call *lhs, constexpr_call *rhs) | |
1174 | { | |
2d76680f | 1175 | if (lhs == rhs) |
46cf7fa1 JJ |
1176 | return true; |
1177 | if (lhs->hash != rhs->hash) | |
1178 | return false; | |
13de99bc | 1179 | if (lhs->manifestly_const_eval != rhs->manifestly_const_eval) |
cce3ae91 | 1180 | return false; |
2d76680f | 1181 | if (!constexpr_fundef_hasher::equal (lhs->fundef, rhs->fundef)) |
46cf7fa1 | 1182 | return false; |
3c961dc7 | 1183 | return cp_tree_equal (lhs->bindings, rhs->bindings); |
2d76680f PC |
1184 | } |
1185 | ||
1186 | /* Initialize the constexpr call table, if needed. */ | |
1187 | ||
1188 | static void | |
1189 | maybe_initialize_constexpr_call_table (void) | |
1190 | { | |
1191 | if (constexpr_call_table == NULL) | |
1192 | constexpr_call_table = hash_table<constexpr_call_hasher>::create_ggc (101); | |
1193 | } | |
1194 | ||
c0daf32d PP |
1195 | /* During constexpr CALL_EXPR evaluation, to avoid issues with sharing when |
1196 | a function happens to get called recursively, we unshare the callee | |
1197 | function's body and evaluate this unshared copy instead of evaluating the | |
1198 | original body. | |
1199 | ||
1200 | FUNDEF_COPIES_TABLE is a per-function freelist of these unshared function | |
1201 | copies. The underlying data structure of FUNDEF_COPIES_TABLE is a hash_map | |
97f3003f JM |
1202 | that's keyed off of the original FUNCTION_DECL and whose value is a |
1203 | TREE_LIST of this function's unused copies awaiting reuse. | |
c0daf32d | 1204 | |
97f3003f | 1205 | This is not GC-deletable to avoid GC affecting UID generation. */ |
c0daf32d | 1206 | |
ba6730bd | 1207 | static GTY(()) decl_tree_map *fundef_copies_table; |
c0daf32d | 1208 | |
c0daf32d | 1209 | /* Reuse a copy or create a new unshared copy of the function FUN. |
3c98ff9b NS |
1210 | Return this copy. We use a TREE_LIST whose PURPOSE is body, VALUE |
1211 | is parms, TYPE is result. */ | |
c0daf32d | 1212 | |
97f3003f | 1213 | static tree |
f65a3299 | 1214 | get_fundef_copy (constexpr_fundef *fundef) |
c0daf32d | 1215 | { |
97f3003f | 1216 | tree copy; |
3c98ff9b | 1217 | bool existed; |
c89844e5 JM |
1218 | tree *slot = &(hash_map_safe_get_or_insert<hm_ggc> |
1219 | (fundef_copies_table, fundef->decl, &existed, 127)); | |
3c98ff9b NS |
1220 | |
1221 | if (!existed) | |
c0daf32d | 1222 | { |
3c98ff9b NS |
1223 | /* There is no cached function available, or in use. We can use |
1224 | the function directly. That the slot is now created records | |
1225 | that this function is now in use. */ | |
43574e4f JJ |
1226 | copy = build_tree_list (fundef->body, fundef->parms); |
1227 | TREE_TYPE (copy) = fundef->result; | |
3c98ff9b NS |
1228 | } |
1229 | else if (*slot == NULL_TREE) | |
1230 | { | |
f65a3299 | 1231 | if (uid_sensitive_constexpr_evaluation_p ()) |
aaa26bf4 JM |
1232 | return NULL_TREE; |
1233 | ||
3c98ff9b | 1234 | /* We've already used the function itself, so make a copy. */ |
97f3003f | 1235 | copy = build_tree_list (NULL, NULL); |
43574e4f JJ |
1236 | tree saved_body = DECL_SAVED_TREE (fundef->decl); |
1237 | tree saved_parms = DECL_ARGUMENTS (fundef->decl); | |
1238 | tree saved_result = DECL_RESULT (fundef->decl); | |
1239 | tree saved_fn = current_function_decl; | |
1240 | DECL_SAVED_TREE (fundef->decl) = fundef->body; | |
1241 | DECL_ARGUMENTS (fundef->decl) = fundef->parms; | |
1242 | DECL_RESULT (fundef->decl) = fundef->result; | |
1243 | current_function_decl = fundef->decl; | |
1244 | TREE_PURPOSE (copy) = copy_fn (fundef->decl, TREE_VALUE (copy), | |
1245 | TREE_TYPE (copy)); | |
1246 | current_function_decl = saved_fn; | |
1247 | DECL_RESULT (fundef->decl) = saved_result; | |
1248 | DECL_ARGUMENTS (fundef->decl) = saved_parms; | |
1249 | DECL_SAVED_TREE (fundef->decl) = saved_body; | |
c0daf32d PP |
1250 | } |
1251 | else | |
1252 | { | |
3c98ff9b | 1253 | /* We have a cached function available. */ |
c0daf32d | 1254 | copy = *slot; |
97f3003f | 1255 | *slot = TREE_CHAIN (copy); |
c0daf32d PP |
1256 | } |
1257 | ||
1258 | return copy; | |
1259 | } | |
1260 | ||
3c98ff9b NS |
1261 | /* Save the copy COPY of function FUN for later reuse by |
1262 | get_fundef_copy(). By construction, there will always be an entry | |
1263 | to find. */ | |
c0daf32d PP |
1264 | |
1265 | static void | |
97f3003f | 1266 | save_fundef_copy (tree fun, tree copy) |
c0daf32d | 1267 | { |
3c98ff9b | 1268 | tree *slot = fundef_copies_table->get (fun); |
97f3003f | 1269 | TREE_CHAIN (copy) = *slot; |
c0daf32d PP |
1270 | *slot = copy; |
1271 | } | |
1272 | ||
2d76680f PC |
1273 | /* We have an expression tree T that represents a call, either CALL_EXPR |
1274 | or AGGR_INIT_EXPR. Return the Nth argument. */ | |
1275 | ||
1276 | static inline tree | |
1277 | get_nth_callarg (tree t, int n) | |
1278 | { | |
1279 | switch (TREE_CODE (t)) | |
1280 | { | |
1281 | case CALL_EXPR: | |
1282 | return CALL_EXPR_ARG (t, n); | |
1283 | ||
1284 | case AGGR_INIT_EXPR: | |
1285 | return AGGR_INIT_EXPR_ARG (t, n); | |
1286 | ||
1287 | default: | |
1288 | gcc_unreachable (); | |
1289 | return NULL; | |
1290 | } | |
1291 | } | |
1292 | ||
2d76680f PC |
1293 | /* Attempt to evaluate T which represents a call to a builtin function. |
1294 | We assume here that all builtin functions evaluate to scalar types | |
1295 | represented by _CST nodes. */ | |
1296 | ||
1297 | static tree | |
5756d0f9 | 1298 | cxx_eval_builtin_function_call (const constexpr_ctx *ctx, tree t, tree fun, |
92a596e8 | 1299 | bool lval, |
2d76680f PC |
1300 | bool *non_constant_p, bool *overflow_p) |
1301 | { | |
1302 | const int nargs = call_expr_nargs (t); | |
1303 | tree *args = (tree *) alloca (nargs * sizeof (tree)); | |
1304 | tree new_call; | |
1305 | int i; | |
5756d0f9 JM |
1306 | |
1307 | /* Don't fold __builtin_constant_p within a constexpr function. */ | |
e4082611 | 1308 | bool bi_const_p = DECL_IS_BUILTIN_CONSTANT_P (fun); |
b925d25d | 1309 | |
fe736ffd JM |
1310 | /* If we aren't requiring a constant expression, defer __builtin_constant_p |
1311 | in a constexpr function until we have values for the parameters. */ | |
b925d25d | 1312 | if (bi_const_p |
4cd3e7df | 1313 | && !ctx->manifestly_const_eval |
5756d0f9 JM |
1314 | && current_function_decl |
1315 | && DECL_DECLARED_CONSTEXPR_P (current_function_decl)) | |
2d76680f | 1316 | { |
5756d0f9 JM |
1317 | *non_constant_p = true; |
1318 | return t; | |
2d76680f | 1319 | } |
5756d0f9 | 1320 | |
e4082611 | 1321 | /* For __builtin_is_constant_evaluated, defer it if not |
13de99bc | 1322 | ctx->manifestly_const_eval, otherwise fold it to true. */ |
3d78e008 | 1323 | if (fndecl_built_in_p (fun, CP_BUILT_IN_IS_CONSTANT_EVALUATED, |
13de99bc | 1324 | BUILT_IN_FRONTEND)) |
e4082611 | 1325 | { |
13de99bc | 1326 | if (!ctx->manifestly_const_eval) |
e4082611 JJ |
1327 | { |
1328 | *non_constant_p = true; | |
1329 | return t; | |
1330 | } | |
1331 | return boolean_true_node; | |
1332 | } | |
1333 | ||
ff603745 JJ |
1334 | if (fndecl_built_in_p (fun, CP_BUILT_IN_SOURCE_LOCATION, BUILT_IN_FRONTEND)) |
1335 | return fold_builtin_source_location (EXPR_LOCATION (t)); | |
1336 | ||
69dc042f JM |
1337 | int strops = 0; |
1338 | int strret = 0; | |
1339 | if (fndecl_built_in_p (fun, BUILT_IN_NORMAL)) | |
1340 | switch (DECL_FUNCTION_CODE (fun)) | |
1341 | { | |
1342 | case BUILT_IN_STRLEN: | |
1343 | case BUILT_IN_STRNLEN: | |
1344 | strops = 1; | |
1345 | break; | |
1346 | case BUILT_IN_MEMCHR: | |
1347 | case BUILT_IN_STRCHR: | |
1348 | case BUILT_IN_STRRCHR: | |
1349 | strops = 1; | |
1350 | strret = 1; | |
1351 | break; | |
1352 | case BUILT_IN_MEMCMP: | |
1353 | case BUILT_IN_STRCMP: | |
1354 | strops = 2; | |
1355 | break; | |
1356 | case BUILT_IN_STRSTR: | |
1357 | strops = 2; | |
1358 | strret = 1; | |
bc13106e JJ |
1359 | break; |
1360 | case BUILT_IN_ASAN_POINTER_COMPARE: | |
1361 | case BUILT_IN_ASAN_POINTER_SUBTRACT: | |
1362 | /* These builtins shall be ignored during constant expression | |
1363 | evaluation. */ | |
1364 | return void_node; | |
69dc042f JM |
1365 | default: |
1366 | break; | |
1367 | } | |
1368 | ||
5756d0f9 JM |
1369 | /* Be permissive for arguments to built-ins; __builtin_constant_p should |
1370 | return constant false for a non-constant argument. */ | |
1371 | constexpr_ctx new_ctx = *ctx; | |
1372 | new_ctx.quiet = true; | |
5756d0f9 | 1373 | for (i = 0; i < nargs; ++i) |
b925d25d | 1374 | { |
69dc042f | 1375 | tree arg = CALL_EXPR_ARG (t, i); |
6f346913 | 1376 | tree oarg = arg; |
69dc042f JM |
1377 | |
1378 | /* To handle string built-ins we need to pass ADDR_EXPR<STRING_CST> since | |
1379 | expand_builtin doesn't know how to look in the values table. */ | |
1380 | bool strop = i < strops; | |
1381 | if (strop) | |
1382 | { | |
1383 | STRIP_NOPS (arg); | |
1384 | if (TREE_CODE (arg) == ADDR_EXPR) | |
1385 | arg = TREE_OPERAND (arg, 0); | |
1386 | else | |
1387 | strop = false; | |
1388 | } | |
1389 | ||
2ff7172a JJ |
1390 | /* If builtin_valid_in_constant_expr_p is true, |
1391 | potential_constant_expression_1 has not recursed into the arguments | |
1392 | of the builtin, verify it here. */ | |
1393 | if (!builtin_valid_in_constant_expr_p (fun) | |
69dc042f | 1394 | || potential_constant_expression (arg)) |
4cd3e7df JJ |
1395 | { |
1396 | bool dummy1 = false, dummy2 = false; | |
69dc042f JM |
1397 | arg = cxx_eval_constant_expression (&new_ctx, arg, false, |
1398 | &dummy1, &dummy2); | |
4cd3e7df JJ |
1399 | } |
1400 | ||
b925d25d | 1401 | if (bi_const_p) |
4cd3e7df | 1402 | /* For __builtin_constant_p, fold all expressions with constant values |
b925d25d | 1403 | even if they aren't C++ constant-expressions. */ |
69dc042f JM |
1404 | arg = cp_fold_rvalue (arg); |
1405 | else if (strop) | |
1406 | { | |
1407 | if (TREE_CODE (arg) == CONSTRUCTOR) | |
1408 | arg = braced_lists_to_strings (TREE_TYPE (arg), arg); | |
1409 | if (TREE_CODE (arg) == STRING_CST) | |
1410 | arg = build_address (arg); | |
6f346913 JM |
1411 | else |
1412 | arg = oarg; | |
69dc042f JM |
1413 | } |
1414 | ||
1415 | args[i] = arg; | |
b925d25d | 1416 | } |
5756d0f9 JM |
1417 | |
1418 | bool save_ffbcp = force_folding_builtin_constant_p; | |
b09a67ea | 1419 | force_folding_builtin_constant_p |= ctx->manifestly_const_eval; |
43574e4f JJ |
1420 | tree save_cur_fn = current_function_decl; |
1421 | /* Return name of ctx->call->fundef->decl for __builtin_FUNCTION (). */ | |
1422 | if (fndecl_built_in_p (fun, BUILT_IN_FUNCTION) | |
1423 | && ctx->call | |
1424 | && ctx->call->fundef) | |
1425 | current_function_decl = ctx->call->fundef->decl; | |
109d2197 JJ |
1426 | new_call = fold_builtin_call_array (EXPR_LOCATION (t), TREE_TYPE (t), |
1427 | CALL_EXPR_FN (t), nargs, args); | |
43574e4f | 1428 | current_function_decl = save_cur_fn; |
5756d0f9 | 1429 | force_folding_builtin_constant_p = save_ffbcp; |
109d2197 JJ |
1430 | if (new_call == NULL) |
1431 | { | |
1432 | if (!*non_constant_p && !ctx->quiet) | |
1433 | { | |
1b6fa695 ML |
1434 | /* Do not allow__builtin_unreachable in constexpr function. |
1435 | The __builtin_unreachable call with BUILTINS_LOCATION | |
1436 | comes from cp_maybe_instrument_return. */ | |
3d78e008 | 1437 | if (fndecl_built_in_p (fun, BUILT_IN_UNREACHABLE) |
1b6fa695 | 1438 | && EXPR_LOCATION (t) == BUILTINS_LOCATION) |
84fa214d | 1439 | error ("%<constexpr%> call flows off the end of the function"); |
1b6fa695 ML |
1440 | else |
1441 | { | |
1442 | new_call = build_call_array_loc (EXPR_LOCATION (t), TREE_TYPE (t), | |
1443 | CALL_EXPR_FN (t), nargs, args); | |
1444 | error ("%q+E is not a constant expression", new_call); | |
1445 | } | |
109d2197 JJ |
1446 | } |
1447 | *non_constant_p = true; | |
1448 | return t; | |
1449 | } | |
1450 | ||
43574e4f | 1451 | if (!potential_constant_expression (new_call)) |
109d2197 JJ |
1452 | { |
1453 | if (!*non_constant_p && !ctx->quiet) | |
1454 | error ("%q+E is not a constant expression", new_call); | |
1455 | *non_constant_p = true; | |
1456 | return t; | |
1457 | } | |
1458 | ||
69dc042f JM |
1459 | if (strret) |
1460 | { | |
1461 | /* memchr returns a pointer into the first argument, but we replaced the | |
1462 | argument above with a STRING_CST; put it back it now. */ | |
1463 | tree op = CALL_EXPR_ARG (t, strret-1); | |
1464 | STRIP_NOPS (new_call); | |
1465 | if (TREE_CODE (new_call) == POINTER_PLUS_EXPR) | |
1466 | TREE_OPERAND (new_call, 0) = op; | |
1467 | else if (TREE_CODE (new_call) == ADDR_EXPR) | |
1468 | new_call = op; | |
1469 | } | |
1470 | ||
109d2197 JJ |
1471 | return cxx_eval_constant_expression (&new_ctx, new_call, lval, |
1472 | non_constant_p, overflow_p); | |
2d76680f PC |
1473 | } |
1474 | ||
1475 | /* TEMP is the constant value of a temporary object of type TYPE. Adjust | |
1476 | the type of the value to match. */ | |
1477 | ||
1478 | static tree | |
1479 | adjust_temp_type (tree type, tree temp) | |
1480 | { | |
47be9509 | 1481 | if (same_type_p (TREE_TYPE (temp), type)) |
2d76680f PC |
1482 | return temp; |
1483 | /* Avoid wrapping an aggregate value in a NOP_EXPR. */ | |
1484 | if (TREE_CODE (temp) == CONSTRUCTOR) | |
b27f74e7 MP |
1485 | { |
1486 | /* build_constructor wouldn't retain various CONSTRUCTOR flags. */ | |
1487 | tree t = copy_node (temp); | |
1488 | TREE_TYPE (t) = type; | |
1489 | return t; | |
1490 | } | |
ff8ba86f JJ |
1491 | if (TREE_CODE (temp) == EMPTY_CLASS_EXPR) |
1492 | return build0 (EMPTY_CLASS_EXPR, type); | |
2d76680f | 1493 | gcc_assert (scalarish_type_p (type)); |
72b091f7 MP |
1494 | /* Now we know we're dealing with a scalar, and a prvalue of non-class |
1495 | type is cv-unqualified. */ | |
1496 | return cp_fold_convert (cv_unqualified (type), temp); | |
2d76680f PC |
1497 | } |
1498 | ||
9b9eb42a JM |
1499 | /* If T is a CONSTRUCTOR, return an unshared copy of T and any |
1500 | sub-CONSTRUCTORs. Otherwise return T. | |
0146e25f | 1501 | |
9b9eb42a JM |
1502 | We use this whenever we initialize an object as a whole, whether it's a |
1503 | parameter, a local variable, or a subobject, so that subsequent | |
1504 | modifications don't affect other places where it was used. */ | |
0146e25f | 1505 | |
1f6857ba | 1506 | tree |
3da7d774 | 1507 | unshare_constructor (tree t MEM_STAT_DECL) |
0146e25f | 1508 | { |
9b9eb42a JM |
1509 | if (!t || TREE_CODE (t) != CONSTRUCTOR) |
1510 | return t; | |
1511 | auto_vec <tree*, 4> ptrs; | |
1512 | ptrs.safe_push (&t); | |
1513 | while (!ptrs.is_empty ()) | |
1514 | { | |
1515 | tree *p = ptrs.pop (); | |
3da7d774 JM |
1516 | tree n = copy_node (*p PASS_MEM_STAT); |
1517 | CONSTRUCTOR_ELTS (n) = vec_safe_copy (CONSTRUCTOR_ELTS (*p) PASS_MEM_STAT); | |
9b9eb42a JM |
1518 | *p = n; |
1519 | vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (n); | |
1520 | constructor_elt *ce; | |
1521 | for (HOST_WIDE_INT i = 0; vec_safe_iterate (v, i, &ce); ++i) | |
1522 | if (TREE_CODE (ce->value) == CONSTRUCTOR) | |
1523 | ptrs.safe_push (&ce->value); | |
1524 | } | |
0146e25f PP |
1525 | return t; |
1526 | } | |
1527 | ||
620adbec JM |
1528 | /* If T is a CONSTRUCTOR, ggc_free T and any sub-CONSTRUCTORs. */ |
1529 | ||
1530 | static void | |
1531 | free_constructor (tree t) | |
1532 | { | |
1533 | if (!t || TREE_CODE (t) != CONSTRUCTOR) | |
1534 | return; | |
1535 | releasing_vec ctors; | |
1536 | vec_safe_push (ctors, t); | |
1537 | while (!ctors->is_empty ()) | |
1538 | { | |
1539 | tree c = ctors->pop (); | |
1540 | if (vec<constructor_elt, va_gc> *elts = CONSTRUCTOR_ELTS (c)) | |
1541 | { | |
1542 | constructor_elt *ce; | |
1543 | for (HOST_WIDE_INT i = 0; vec_safe_iterate (elts, i, &ce); ++i) | |
1544 | if (TREE_CODE (ce->value) == CONSTRUCTOR) | |
1545 | vec_safe_push (ctors, ce->value); | |
1546 | ggc_free (elts); | |
1547 | } | |
1548 | ggc_free (c); | |
1549 | } | |
1550 | } | |
1551 | ||
2d76680f PC |
1552 | /* Subroutine of cxx_eval_call_expression. |
1553 | We are processing a call expression (either CALL_EXPR or | |
3e605b20 | 1554 | AGGR_INIT_EXPR) in the context of CTX. Evaluate |
2d76680f PC |
1555 | all arguments and bind their values to correspondings |
1556 | parameters, making up the NEW_CALL context. */ | |
1557 | ||
1558 | static void | |
3e605b20 | 1559 | cxx_bind_parameters_in_call (const constexpr_ctx *ctx, tree t, |
2d76680f | 1560 | constexpr_call *new_call, |
12d9ce19 JM |
1561 | bool *non_constant_p, bool *overflow_p, |
1562 | bool *non_constant_args) | |
2d76680f PC |
1563 | { |
1564 | const int nargs = call_expr_nargs (t); | |
1565 | tree fun = new_call->fundef->decl; | |
43574e4f | 1566 | tree parms = new_call->fundef->parms; |
2d76680f | 1567 | int i; |
3c961dc7 JM |
1568 | /* We don't record ellipsis args below. */ |
1569 | int nparms = list_length (parms); | |
1570 | int nbinds = nargs < nparms ? nargs : nparms; | |
1571 | tree binds = new_call->bindings = make_tree_vec (nbinds); | |
2d76680f PC |
1572 | for (i = 0; i < nargs; ++i) |
1573 | { | |
1574 | tree x, arg; | |
1575 | tree type = parms ? TREE_TYPE (parms) : void_type_node; | |
2d76680f | 1576 | x = get_nth_callarg (t, i); |
3e605b20 JM |
1577 | /* For member function, the first argument is a pointer to the implied |
1578 | object. For a constructor, it might still be a dummy object, in | |
60813a46 | 1579 | which case we get the real argument from ctx. */ |
3e605b20 JM |
1580 | if (i == 0 && DECL_CONSTRUCTOR_P (fun) |
1581 | && is_dummy_object (x)) | |
1582 | { | |
1583 | x = ctx->object; | |
84dd815f | 1584 | x = build_address (x); |
3e605b20 | 1585 | } |
43574e4f JJ |
1586 | if (TREE_ADDRESSABLE (type)) |
1587 | /* Undo convert_for_arg_passing work here. */ | |
1588 | x = convert_from_reference (x); | |
0e038601 | 1589 | arg = cxx_eval_constant_expression (ctx, x, /*lval=*/false, |
5a804683 | 1590 | non_constant_p, overflow_p); |
2d76680f | 1591 | /* Don't VERIFY_CONSTANT here. */ |
2b3ab879 | 1592 | if (*non_constant_p && ctx->quiet) |
2d76680f PC |
1593 | return; |
1594 | /* Just discard ellipsis args after checking their constantitude. */ | |
1595 | if (!parms) | |
1596 | continue; | |
4727d4c6 NS |
1597 | |
1598 | if (!*non_constant_p) | |
1599 | { | |
1600 | /* Make sure the binding has the same type as the parm. But | |
1601 | only for constant args. */ | |
9f613f06 | 1602 | if (!TYPE_REF_P (type)) |
4727d4c6 NS |
1603 | arg = adjust_temp_type (type, arg); |
1604 | if (!TREE_CONSTANT (arg)) | |
1605 | *non_constant_args = true; | |
5afd90c5 JJ |
1606 | else if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)) |
1607 | /* The destructor needs to see any modifications the callee makes | |
1608 | to the argument. */ | |
1609 | *non_constant_args = true; | |
1610 | ||
5558a0da JJ |
1611 | /* For virtual calls, adjust the this argument, so that it is |
1612 | the object on which the method is called, rather than | |
1613 | one of its bases. */ | |
1614 | if (i == 0 && DECL_VIRTUAL_P (fun)) | |
1615 | { | |
1616 | tree addr = arg; | |
1617 | STRIP_NOPS (addr); | |
1618 | if (TREE_CODE (addr) == ADDR_EXPR) | |
1619 | { | |
1620 | tree obj = TREE_OPERAND (addr, 0); | |
1621 | while (TREE_CODE (obj) == COMPONENT_REF | |
1622 | && DECL_FIELD_IS_BASE (TREE_OPERAND (obj, 1)) | |
1623 | && !same_type_ignoring_top_level_qualifiers_p | |
1624 | (TREE_TYPE (obj), DECL_CONTEXT (fun))) | |
1625 | obj = TREE_OPERAND (obj, 0); | |
1626 | if (obj != TREE_OPERAND (addr, 0)) | |
1627 | arg = build_fold_addr_expr_with_type (obj, | |
1628 | TREE_TYPE (arg)); | |
1629 | } | |
1630 | } | |
3c961dc7 | 1631 | TREE_VEC_ELT (binds, i) = arg; |
4727d4c6 | 1632 | } |
2d76680f PC |
1633 | parms = TREE_CHAIN (parms); |
1634 | } | |
1635 | } | |
1636 | ||
1637 | /* Variables and functions to manage constexpr call expansion context. | |
1638 | These do not need to be marked for PCH or GC. */ | |
1639 | ||
1640 | /* FIXME remember and print actual constant arguments. */ | |
7de76362 | 1641 | static vec<tree> call_stack; |
2d76680f PC |
1642 | static int call_stack_tick; |
1643 | static int last_cx_error_tick; | |
1644 | ||
7ffc7de5 | 1645 | static int |
2d76680f PC |
1646 | push_cx_call_context (tree call) |
1647 | { | |
1648 | ++call_stack_tick; | |
1649 | if (!EXPR_HAS_LOCATION (call)) | |
1650 | SET_EXPR_LOCATION (call, input_location); | |
1651 | call_stack.safe_push (call); | |
7ffc7de5 JM |
1652 | int len = call_stack.length (); |
1653 | if (len > max_constexpr_depth) | |
2d76680f | 1654 | return false; |
7ffc7de5 | 1655 | return len; |
2d76680f PC |
1656 | } |
1657 | ||
1658 | static void | |
1659 | pop_cx_call_context (void) | |
1660 | { | |
1661 | ++call_stack_tick; | |
1662 | call_stack.pop (); | |
1663 | } | |
1664 | ||
1665 | vec<tree> | |
1666 | cx_error_context (void) | |
1667 | { | |
1668 | vec<tree> r = vNULL; | |
1669 | if (call_stack_tick != last_cx_error_tick | |
1670 | && !call_stack.is_empty ()) | |
1671 | r = call_stack; | |
1672 | last_cx_error_tick = call_stack_tick; | |
1673 | return r; | |
1674 | } | |
1675 | ||
44a845ca MS |
1676 | /* Evaluate a call T to a GCC internal function when possible and return |
1677 | the evaluated result or, under the control of CTX, give an error, set | |
1678 | NON_CONSTANT_P, and return the unevaluated call T otherwise. */ | |
1679 | ||
1680 | static tree | |
1681 | cxx_eval_internal_function (const constexpr_ctx *ctx, tree t, | |
1682 | bool lval, | |
1683 | bool *non_constant_p, bool *overflow_p) | |
1684 | { | |
1685 | enum tree_code opcode = ERROR_MARK; | |
1686 | ||
1687 | switch (CALL_EXPR_IFN (t)) | |
1688 | { | |
1689 | case IFN_UBSAN_NULL: | |
1690 | case IFN_UBSAN_BOUNDS: | |
1691 | case IFN_UBSAN_VPTR: | |
81fea426 | 1692 | case IFN_FALLTHROUGH: |
44a845ca MS |
1693 | return void_node; |
1694 | ||
1695 | case IFN_ADD_OVERFLOW: | |
1696 | opcode = PLUS_EXPR; | |
1697 | break; | |
1698 | case IFN_SUB_OVERFLOW: | |
1699 | opcode = MINUS_EXPR; | |
1700 | break; | |
1701 | case IFN_MUL_OVERFLOW: | |
1702 | opcode = MULT_EXPR; | |
1703 | break; | |
1704 | ||
e16f1cc7 JJ |
1705 | case IFN_LAUNDER: |
1706 | return cxx_eval_constant_expression (ctx, CALL_EXPR_ARG (t, 0), | |
1707 | false, non_constant_p, overflow_p); | |
1708 | ||
d8fcab68 JJ |
1709 | case IFN_VEC_CONVERT: |
1710 | { | |
1711 | tree arg = cxx_eval_constant_expression (ctx, CALL_EXPR_ARG (t, 0), | |
1712 | false, non_constant_p, | |
1713 | overflow_p); | |
1714 | if (TREE_CODE (arg) == VECTOR_CST) | |
1715 | return fold_const_call (CFN_VEC_CONVERT, TREE_TYPE (t), arg); | |
1716 | else | |
1717 | { | |
1718 | *non_constant_p = true; | |
1719 | return t; | |
1720 | } | |
1721 | } | |
1722 | ||
44a845ca MS |
1723 | default: |
1724 | if (!ctx->quiet) | |
f9d0ca40 | 1725 | error_at (cp_expr_loc_or_input_loc (t), |
44a845ca MS |
1726 | "call to internal function %qE", t); |
1727 | *non_constant_p = true; | |
1728 | return t; | |
1729 | } | |
1730 | ||
1731 | /* Evaluate constant arguments using OPCODE and return a complex | |
1732 | number containing the result and the overflow bit. */ | |
1733 | tree arg0 = cxx_eval_constant_expression (ctx, CALL_EXPR_ARG (t, 0), lval, | |
1734 | non_constant_p, overflow_p); | |
1735 | tree arg1 = cxx_eval_constant_expression (ctx, CALL_EXPR_ARG (t, 1), lval, | |
1736 | non_constant_p, overflow_p); | |
1737 | ||
1738 | if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST) | |
1739 | { | |
f9d0ca40 | 1740 | location_t loc = cp_expr_loc_or_input_loc (t); |
44a845ca MS |
1741 | tree type = TREE_TYPE (TREE_TYPE (t)); |
1742 | tree result = fold_binary_loc (loc, opcode, type, | |
1743 | fold_convert_loc (loc, type, arg0), | |
1744 | fold_convert_loc (loc, type, arg1)); | |
1745 | tree ovf | |
1746 | = build_int_cst (type, arith_overflowed_p (opcode, type, arg0, arg1)); | |
1747 | /* Reset TREE_OVERFLOW to avoid warnings for the overflow. */ | |
1748 | if (TREE_OVERFLOW (result)) | |
1749 | TREE_OVERFLOW (result) = 0; | |
1750 | ||
1751 | return build_complex (TREE_TYPE (t), result, ovf); | |
1752 | } | |
1753 | ||
1754 | *non_constant_p = true; | |
1755 | return t; | |
1756 | } | |
1757 | ||
e8c48716 | 1758 | /* Clean CONSTRUCTOR_NO_CLEARING from CTOR and its sub-aggregates. */ |
ecc57615 JM |
1759 | |
1760 | static void | |
1761 | clear_no_implicit_zero (tree ctor) | |
1762 | { | |
e8c48716 | 1763 | if (CONSTRUCTOR_NO_CLEARING (ctor)) |
ecc57615 | 1764 | { |
e8c48716 | 1765 | CONSTRUCTOR_NO_CLEARING (ctor) = false; |
ecc57615 JM |
1766 | tree elt; unsigned HOST_WIDE_INT idx; |
1767 | FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), idx, elt) | |
1768 | if (TREE_CODE (elt) == CONSTRUCTOR) | |
1769 | clear_no_implicit_zero (elt); | |
1770 | } | |
1771 | } | |
1772 | ||
04e1749c MP |
1773 | /* Complain about a const object OBJ being modified in a constant expression. |
1774 | EXPR is the MODIFY_EXPR expression performing the modification. */ | |
1775 | ||
1776 | static void | |
1777 | modifying_const_object_error (tree expr, tree obj) | |
1778 | { | |
1779 | location_t loc = cp_expr_loc_or_input_loc (expr); | |
1780 | auto_diagnostic_group d; | |
1781 | error_at (loc, "modifying a const object %qE is not allowed in " | |
1782 | "a constant expression", TREE_OPERAND (expr, 0)); | |
1783 | inform (location_of (obj), "originally declared %<const%> here"); | |
1784 | } | |
1785 | ||
8e007055 JJ |
1786 | /* Return true if FNDECL is a replaceable global allocation function that |
1787 | should be useable during constant expression evaluation. */ | |
1788 | ||
1789 | static inline bool | |
1790 | cxx_replaceable_global_alloc_fn (tree fndecl) | |
1791 | { | |
b04445d4 | 1792 | return (cxx_dialect >= cxx20 |
8e007055 | 1793 | && IDENTIFIER_NEWDEL_OP_P (DECL_NAME (fndecl)) |
cf650568 JJ |
1794 | && CP_DECL_CONTEXT (fndecl) == global_namespace |
1795 | && (DECL_IS_REPLACEABLE_OPERATOR_NEW_P (fndecl) | |
1796 | || DECL_IS_OPERATOR_DELETE_P (fndecl))); | |
1797 | } | |
1798 | ||
1799 | /* Return true if FNDECL is a placement new function that should be | |
1800 | useable during constant expression evaluation of std::construct_at. */ | |
1801 | ||
1802 | static inline bool | |
1803 | cxx_placement_new_fn (tree fndecl) | |
1804 | { | |
b04445d4 | 1805 | if (cxx_dialect >= cxx20 |
cf650568 JJ |
1806 | && IDENTIFIER_NEW_OP_P (DECL_NAME (fndecl)) |
1807 | && CP_DECL_CONTEXT (fndecl) == global_namespace | |
1808 | && !DECL_IS_REPLACEABLE_OPERATOR_NEW_P (fndecl) | |
1809 | && TREE_CODE (TREE_TYPE (fndecl)) == FUNCTION_TYPE) | |
1810 | { | |
1811 | tree first_arg = TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (fndecl))); | |
1812 | if (TREE_VALUE (first_arg) == ptr_type_node | |
1813 | && TREE_CHAIN (first_arg) == void_list_node) | |
1814 | return true; | |
1815 | } | |
1816 | return false; | |
1817 | } | |
1818 | ||
1819 | /* Return true if FNDECL is std::construct_at. */ | |
1820 | ||
1821 | static inline bool | |
1822 | is_std_construct_at (tree fndecl) | |
1823 | { | |
1824 | if (!decl_in_std_namespace_p (fndecl)) | |
1825 | return false; | |
1826 | ||
1827 | tree name = DECL_NAME (fndecl); | |
1828 | return name && id_equal (name, "construct_at"); | |
8e007055 JJ |
1829 | } |
1830 | ||
8412b939 JJ |
1831 | /* Return true if FNDECL is std::allocator<T>::{,de}allocate. */ |
1832 | ||
1833 | static inline bool | |
1834 | is_std_allocator_allocate (tree fndecl) | |
1835 | { | |
1836 | tree name = DECL_NAME (fndecl); | |
1837 | if (name == NULL_TREE | |
1838 | || !(id_equal (name, "allocate") || id_equal (name, "deallocate"))) | |
1839 | return false; | |
1840 | ||
1841 | tree ctx = DECL_CONTEXT (fndecl); | |
1842 | if (ctx == NULL_TREE || !CLASS_TYPE_P (ctx) || !TYPE_MAIN_DECL (ctx)) | |
1843 | return false; | |
1844 | ||
1845 | tree decl = TYPE_MAIN_DECL (ctx); | |
1846 | name = DECL_NAME (decl); | |
1847 | if (name == NULL_TREE || !id_equal (name, "allocator")) | |
1848 | return false; | |
1849 | ||
1850 | return decl_in_std_namespace_p (decl); | |
1851 | } | |
1852 | ||
22edf943 MP |
1853 | /* Return true if FNDECL is __dynamic_cast. */ |
1854 | ||
1855 | static inline bool | |
1856 | cxx_dynamic_cast_fn_p (tree fndecl) | |
1857 | { | |
b04445d4 | 1858 | return (cxx_dialect >= cxx20 |
22edf943 MP |
1859 | && id_equal (DECL_NAME (fndecl), "__dynamic_cast") |
1860 | && CP_DECL_CONTEXT (fndecl) == global_namespace); | |
1861 | } | |
1862 | ||
1863 | /* Often, we have an expression in the form of address + offset, e.g. | |
1864 | "&_ZTV1A + 16". Extract the object from it, i.e. "_ZTV1A". */ | |
1865 | ||
1866 | static tree | |
1867 | extract_obj_from_addr_offset (tree expr) | |
1868 | { | |
1869 | if (TREE_CODE (expr) == POINTER_PLUS_EXPR) | |
1870 | expr = TREE_OPERAND (expr, 0); | |
1871 | STRIP_NOPS (expr); | |
1872 | if (TREE_CODE (expr) == ADDR_EXPR) | |
1873 | expr = TREE_OPERAND (expr, 0); | |
1874 | return expr; | |
1875 | } | |
1876 | ||
1877 | /* Given a PATH like | |
1878 | ||
1879 | g.D.2181.D.2154.D.2102.D.2093 | |
1880 | ||
1881 | find a component with type TYPE. Return NULL_TREE if not found, and | |
1882 | error_mark_node if the component is not accessible. If STOP is non-null, | |
1883 | this function will return NULL_TREE if STOP is found before TYPE. */ | |
1884 | ||
1885 | static tree | |
1886 | get_component_with_type (tree path, tree type, tree stop) | |
1887 | { | |
1888 | while (true) | |
1889 | { | |
1890 | if (same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (path), type)) | |
1891 | /* Found it. */ | |
1892 | return path; | |
1893 | else if (stop | |
1894 | && (same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (path), | |
1895 | stop))) | |
1896 | return NULL_TREE; | |
1897 | else if (TREE_CODE (path) == COMPONENT_REF | |
1898 | && DECL_FIELD_IS_BASE (TREE_OPERAND (path, 1))) | |
1899 | { | |
1900 | /* We need to check that the component we're accessing is in fact | |
1901 | accessible. */ | |
1902 | if (TREE_PRIVATE (TREE_OPERAND (path, 1)) | |
1903 | || TREE_PROTECTED (TREE_OPERAND (path, 1))) | |
1904 | return error_mark_node; | |
1905 | path = TREE_OPERAND (path, 0); | |
1906 | } | |
1907 | else | |
1908 | return NULL_TREE; | |
1909 | } | |
1910 | } | |
1911 | ||
1912 | /* Evaluate a call to __dynamic_cast (permitted by P1327R1). | |
1913 | ||
1914 | The declaration of __dynamic_cast is: | |
1915 | ||
1916 | void* __dynamic_cast (const void* __src_ptr, | |
1917 | const __class_type_info* __src_type, | |
1918 | const __class_type_info* __dst_type, | |
1919 | ptrdiff_t __src2dst); | |
1920 | ||
1921 | where src2dst has the following possible values | |
1922 | ||
1923 | >-1: src_type is a unique public non-virtual base of dst_type | |
1924 | dst_ptr + src2dst == src_ptr | |
1925 | -1: unspecified relationship | |
1926 | -2: src_type is not a public base of dst_type | |
1927 | -3: src_type is a multiple public non-virtual base of dst_type | |
1928 | ||
1929 | Since literal types can't have virtual bases, we only expect hint >=0, | |
1930 | -2, or -3. */ | |
1931 | ||
1932 | static tree | |
1933 | cxx_eval_dynamic_cast_fn (const constexpr_ctx *ctx, tree call, | |
1934 | bool *non_constant_p, bool *overflow_p) | |
1935 | { | |
1936 | /* T will be something like | |
1937 | __dynamic_cast ((B*) b, &_ZTI1B, &_ZTI1D, 8) | |
1938 | dismantle it. */ | |
1939 | gcc_assert (call_expr_nargs (call) == 4); | |
1940 | tsubst_flags_t complain = ctx->quiet ? tf_none : tf_warning_or_error; | |
1941 | tree obj = CALL_EXPR_ARG (call, 0); | |
1942 | tree type = CALL_EXPR_ARG (call, 2); | |
1943 | HOST_WIDE_INT hint = int_cst_value (CALL_EXPR_ARG (call, 3)); | |
1944 | location_t loc = cp_expr_loc_or_input_loc (call); | |
1945 | ||
1946 | /* Get the target type of the dynamic_cast. */ | |
1947 | gcc_assert (TREE_CODE (type) == ADDR_EXPR); | |
1948 | type = TREE_OPERAND (type, 0); | |
1949 | type = TREE_TYPE (DECL_NAME (type)); | |
1950 | ||
1951 | /* TYPE can only be either T* or T&. We can't know which of these it | |
1952 | is by looking at TYPE, but OBJ will be "(T*) x" in the first case, | |
1953 | and something like "(T*)(T&)(T*) x" in the second case. */ | |
1954 | bool reference_p = false; | |
1955 | while (CONVERT_EXPR_P (obj) || TREE_CODE (obj) == SAVE_EXPR) | |
1956 | { | |
1957 | reference_p |= TYPE_REF_P (TREE_TYPE (obj)); | |
1958 | obj = TREE_OPERAND (obj, 0); | |
1959 | } | |
1960 | ||
1961 | /* Evaluate the object so that we know its dynamic type. */ | |
1962 | obj = cxx_eval_constant_expression (ctx, obj, /*lval*/false, non_constant_p, | |
1963 | overflow_p); | |
1964 | if (*non_constant_p) | |
1965 | return call; | |
1966 | ||
1967 | /* We expect OBJ to be in form of &d.D.2102 when HINT == 0, | |
1968 | but when HINT is > 0, it can also be something like | |
1969 | &d.D.2102 + 18446744073709551608, which includes the BINFO_OFFSET. */ | |
1970 | obj = extract_obj_from_addr_offset (obj); | |
1971 | const tree objtype = TREE_TYPE (obj); | |
1972 | /* If OBJ doesn't refer to a base field, we're done. */ | |
1973 | if (tree t = (TREE_CODE (obj) == COMPONENT_REF | |
1974 | ? TREE_OPERAND (obj, 1) : obj)) | |
1975 | if (TREE_CODE (t) != FIELD_DECL || !DECL_FIELD_IS_BASE (t)) | |
de0684bf MP |
1976 | { |
1977 | if (reference_p) | |
1978 | { | |
1979 | if (!ctx->quiet) | |
1980 | { | |
1981 | error_at (loc, "reference %<dynamic_cast%> failed"); | |
1982 | inform (loc, "dynamic type %qT of its operand does " | |
1983 | "not have a base class of type %qT", | |
1984 | objtype, type); | |
1985 | } | |
1986 | *non_constant_p = true; | |
1987 | } | |
1988 | return integer_zero_node; | |
1989 | } | |
22edf943 MP |
1990 | |
1991 | /* [class.cdtor] When a dynamic_cast is used in a constructor ... | |
1992 | or in a destructor ... if the operand of the dynamic_cast refers | |
1993 | to the object under construction or destruction, this object is | |
1994 | considered to be a most derived object that has the type of the | |
1995 | constructor or destructor's class. */ | |
1996 | tree vtable = build_vfield_ref (obj, TREE_TYPE (obj)); | |
1997 | vtable = cxx_eval_constant_expression (ctx, vtable, /*lval*/false, | |
1998 | non_constant_p, overflow_p); | |
1999 | if (*non_constant_p) | |
2000 | return call; | |
2001 | /* VTABLE will be &_ZTV1A + 16 or similar, get _ZTV1A. */ | |
2002 | vtable = extract_obj_from_addr_offset (vtable); | |
2003 | const tree mdtype = DECL_CONTEXT (vtable); | |
2004 | ||
2005 | /* Given dynamic_cast<T>(v), | |
2006 | ||
2007 | [expr.dynamic.cast] If C is the class type to which T points or refers, | |
2008 | the runtime check logically executes as follows: | |
2009 | ||
2010 | If, in the most derived object pointed (referred) to by v, v points | |
2011 | (refers) to a public base class subobject of a C object, and if only | |
2012 | one object of type C is derived from the subobject pointed (referred) | |
2013 | to by v the result points (refers) to that C object. | |
2014 | ||
2015 | In this case, HINT >= 0 or -3. */ | |
2016 | if (hint >= 0 || hint == -3) | |
2017 | { | |
2018 | /* Look for a component with type TYPE. */ | |
2019 | tree t = get_component_with_type (obj, type, mdtype); | |
2020 | /* If not accessible, give an error. */ | |
2021 | if (t == error_mark_node) | |
2022 | { | |
2023 | if (reference_p) | |
2024 | { | |
2025 | if (!ctx->quiet) | |
2026 | { | |
2027 | error_at (loc, "reference %<dynamic_cast%> failed"); | |
2028 | inform (loc, "static type %qT of its operand is a " | |
2029 | "non-public base class of dynamic type %qT", | |
2030 | objtype, type); | |
2031 | ||
2032 | } | |
2033 | *non_constant_p = true; | |
2034 | } | |
2035 | return integer_zero_node; | |
2036 | } | |
2037 | else if (t) | |
2038 | /* The result points to the TYPE object. */ | |
2039 | return cp_build_addr_expr (t, complain); | |
2040 | /* Else, TYPE was not found, because the HINT turned out to be wrong. | |
2041 | Fall through to the normal processing. */ | |
2042 | } | |
2043 | ||
2044 | /* Otherwise, if v points (refers) to a public base class subobject of the | |
2045 | most derived object, and the type of the most derived object has a base | |
2046 | class, of type C, that is unambiguous and public, the result points | |
2047 | (refers) to the C subobject of the most derived object. | |
2048 | ||
2049 | But it can also be an invalid case. */ | |
2050 | ||
2051 | /* Get the most derived object. */ | |
2052 | obj = get_component_with_type (obj, mdtype, NULL_TREE); | |
2053 | if (obj == error_mark_node) | |
2054 | { | |
2055 | if (reference_p) | |
2056 | { | |
2057 | if (!ctx->quiet) | |
2058 | { | |
2059 | error_at (loc, "reference %<dynamic_cast%> failed"); | |
2060 | inform (loc, "static type %qT of its operand is a non-public" | |
2061 | " base class of dynamic type %qT", objtype, mdtype); | |
2062 | } | |
2063 | *non_constant_p = true; | |
2064 | } | |
2065 | return integer_zero_node; | |
2066 | } | |
2067 | else | |
2068 | gcc_assert (obj); | |
2069 | ||
2070 | /* Check that the type of the most derived object has a base class | |
2071 | of type TYPE that is unambiguous and public. */ | |
2072 | base_kind b_kind; | |
2073 | tree binfo = lookup_base (mdtype, type, ba_check, &b_kind, tf_none); | |
2074 | if (!binfo || binfo == error_mark_node) | |
2075 | { | |
2076 | if (reference_p) | |
2077 | { | |
2078 | if (!ctx->quiet) | |
2079 | { | |
2080 | error_at (loc, "reference %<dynamic_cast%> failed"); | |
2081 | if (b_kind == bk_ambig) | |
2082 | inform (loc, "%qT is an ambiguous base class of dynamic " | |
2083 | "type %qT of its operand", type, mdtype); | |
2084 | else | |
2085 | inform (loc, "dynamic type %qT of its operand does not " | |
2086 | "have an unambiguous public base class %qT", | |
2087 | mdtype, type); | |
2088 | } | |
2089 | *non_constant_p = true; | |
2090 | } | |
2091 | return integer_zero_node; | |
2092 | } | |
2093 | /* If so, return the TYPE subobject of the most derived object. */ | |
2094 | obj = convert_to_base_statically (obj, binfo); | |
2095 | return cp_build_addr_expr (obj, complain); | |
2096 | } | |
2097 | ||
b2562229 PP |
2098 | /* Data structure used by replace_result_decl and replace_result_decl_r. */ |
2099 | ||
2100 | struct replace_result_decl_data | |
2101 | { | |
2102 | /* The RESULT_DECL we want to replace. */ | |
2103 | tree decl; | |
2104 | /* The replacement for DECL. */ | |
2105 | tree replacement; | |
2106 | /* Whether we've performed any replacements. */ | |
2107 | bool changed; | |
2108 | }; | |
2109 | ||
2110 | /* Helper function for replace_result_decl, called through cp_walk_tree. */ | |
2111 | ||
2112 | static tree | |
2113 | replace_result_decl_r (tree *tp, int *walk_subtrees, void *data) | |
2114 | { | |
2115 | replace_result_decl_data *d = (replace_result_decl_data *) data; | |
2116 | ||
2117 | if (*tp == d->decl) | |
2118 | { | |
2119 | *tp = unshare_expr (d->replacement); | |
2120 | d->changed = true; | |
2121 | *walk_subtrees = 0; | |
2122 | } | |
2123 | else if (TYPE_P (*tp)) | |
2124 | *walk_subtrees = 0; | |
2125 | ||
2126 | return NULL_TREE; | |
2127 | } | |
2128 | ||
2129 | /* Replace every occurrence of DECL, a RESULT_DECL, with (an unshared copy of) | |
2130 | REPLACEMENT within the reduced constant expression *TP. Returns true iff a | |
2131 | replacement was performed. */ | |
2132 | ||
2133 | static bool | |
2134 | replace_result_decl (tree *tp, tree decl, tree replacement) | |
2135 | { | |
2136 | gcc_checking_assert (TREE_CODE (decl) == RESULT_DECL | |
2137 | && (same_type_ignoring_top_level_qualifiers_p | |
2138 | (TREE_TYPE (decl), TREE_TYPE (replacement)))); | |
2139 | replace_result_decl_data data = { decl, replacement, false }; | |
2140 | cp_walk_tree_without_duplicates (tp, replace_result_decl_r, &data); | |
2141 | return data.changed; | |
2142 | } | |
2143 | ||
e6321c45 JM |
2144 | /* Evaluate the call T to virtual function thunk THUNK_FNDECL. */ |
2145 | ||
2146 | static tree | |
2147 | cxx_eval_thunk_call (const constexpr_ctx *ctx, tree t, tree thunk_fndecl, | |
2148 | bool lval, | |
2149 | bool *non_constant_p, bool *overflow_p) | |
2150 | { | |
2151 | tree function = THUNK_TARGET (thunk_fndecl); | |
2152 | ||
2153 | /* virtual_offset is only set in the presence of virtual bases, which make | |
2154 | the class non-literal, so we don't need to handle it here. */ | |
2155 | if (THUNK_VIRTUAL_OFFSET (thunk_fndecl)) | |
2156 | { | |
2157 | gcc_assert (!DECL_DECLARED_CONSTEXPR_P (function)); | |
2158 | if (!ctx->quiet) | |
2159 | { | |
2160 | error ("call to non-%<constexpr%> function %qD", function); | |
2161 | explain_invalid_constexpr_fn (function); | |
2162 | } | |
2163 | *non_constant_p = true; | |
2164 | return t; | |
2165 | } | |
2166 | ||
2167 | tree new_call = copy_node (t); | |
2168 | CALL_EXPR_FN (new_call) = function; | |
2169 | TREE_TYPE (new_call) = TREE_TYPE (TREE_TYPE (function)); | |
2170 | ||
2171 | tree offset = size_int (THUNK_FIXED_OFFSET (thunk_fndecl)); | |
2172 | ||
2173 | if (DECL_THIS_THUNK_P (thunk_fndecl)) | |
2174 | { | |
2175 | /* 'this'-adjusting thunk. */ | |
2176 | tree this_arg = CALL_EXPR_ARG (t, 0); | |
2177 | this_arg = build2 (POINTER_PLUS_EXPR, TREE_TYPE (this_arg), | |
2178 | this_arg, offset); | |
2179 | CALL_EXPR_ARG (new_call, 0) = this_arg; | |
2180 | } | |
2181 | else | |
2182 | /* Return-adjusting thunk. */ | |
2183 | new_call = build2 (POINTER_PLUS_EXPR, TREE_TYPE (new_call), | |
2184 | new_call, offset); | |
2185 | ||
2186 | return cxx_eval_constant_expression (ctx, new_call, lval, | |
2187 | non_constant_p, overflow_p); | |
2188 | } | |
2189 | ||
caf17f3a MP |
2190 | /* If OBJECT is of const class type, evaluate it to a CONSTRUCTOR and set |
2191 | its TREE_READONLY flag according to READONLY_P. Used for constexpr | |
2192 | 'tors to detect modifying const objects in a constexpr context. */ | |
2193 | ||
2194 | static void | |
2195 | cxx_set_object_constness (const constexpr_ctx *ctx, tree object, | |
2196 | bool readonly_p, bool *non_constant_p, | |
2197 | bool *overflow_p) | |
2198 | { | |
2199 | if (CLASS_TYPE_P (TREE_TYPE (object)) | |
2200 | && CP_TYPE_CONST_P (TREE_TYPE (object))) | |
2201 | { | |
2202 | /* Subobjects might not be stored in ctx->global->values but we | |
2203 | can get its CONSTRUCTOR by evaluating *this. */ | |
2204 | tree e = cxx_eval_constant_expression (ctx, object, /*lval*/false, | |
2205 | non_constant_p, overflow_p); | |
2206 | if (TREE_CODE (e) == CONSTRUCTOR && !*non_constant_p) | |
2207 | TREE_READONLY (e) = readonly_p; | |
2208 | } | |
2209 | } | |
2210 | ||
2d76680f PC |
2211 | /* Subroutine of cxx_eval_constant_expression. |
2212 | Evaluate the call expression tree T in the context of OLD_CALL expression | |
2213 | evaluation. */ | |
2214 | ||
2215 | static tree | |
3e605b20 | 2216 | cxx_eval_call_expression (const constexpr_ctx *ctx, tree t, |
92a596e8 | 2217 | bool lval, |
2d76680f PC |
2218 | bool *non_constant_p, bool *overflow_p) |
2219 | { | |
861d4af8 AS |
2220 | /* Handle concept checks separately. */ |
2221 | if (concept_check_p (t)) | |
2222 | return evaluate_concept_check (t, tf_warning_or_error); | |
2223 | ||
f9d0ca40 | 2224 | location_t loc = cp_expr_loc_or_input_loc (t); |
2d76680f | 2225 | tree fun = get_function_named_in_call (t); |
cce3ae91 | 2226 | constexpr_call new_call |
13de99bc | 2227 | = { NULL, NULL, NULL, 0, ctx->manifestly_const_eval }; |
7ffc7de5 | 2228 | int depth_ok; |
2d76680f | 2229 | |
0b274c17 | 2230 | if (fun == NULL_TREE) |
44a845ca MS |
2231 | return cxx_eval_internal_function (ctx, t, lval, |
2232 | non_constant_p, overflow_p); | |
0b274c17 | 2233 | |
2d76680f PC |
2234 | if (TREE_CODE (fun) != FUNCTION_DECL) |
2235 | { | |
2236 | /* Might be a constexpr function pointer. */ | |
2b3ab879 | 2237 | fun = cxx_eval_constant_expression (ctx, fun, |
92a596e8 | 2238 | /*lval*/false, non_constant_p, |
5a804683 | 2239 | overflow_p); |
2d76680f PC |
2240 | STRIP_NOPS (fun); |
2241 | if (TREE_CODE (fun) == ADDR_EXPR) | |
2242 | fun = TREE_OPERAND (fun, 0); | |
582d2481 JJ |
2243 | /* For TARGET_VTABLE_USES_DESCRIPTORS targets, there is no |
2244 | indirection, the called expression is a pointer into the | |
2245 | virtual table which should contain FDESC_EXPR. Extract the | |
2246 | FUNCTION_DECL from there. */ | |
2247 | else if (TARGET_VTABLE_USES_DESCRIPTORS | |
2248 | && TREE_CODE (fun) == POINTER_PLUS_EXPR | |
2249 | && TREE_CODE (TREE_OPERAND (fun, 0)) == ADDR_EXPR | |
2250 | && TREE_CODE (TREE_OPERAND (fun, 1)) == INTEGER_CST) | |
2251 | { | |
2252 | tree d = TREE_OPERAND (TREE_OPERAND (fun, 0), 0); | |
2253 | if (VAR_P (d) | |
2254 | && DECL_VTABLE_OR_VTT_P (d) | |
2255 | && TREE_CODE (TREE_TYPE (d)) == ARRAY_TYPE | |
2256 | && TREE_TYPE (TREE_TYPE (d)) == vtable_entry_type | |
2257 | && DECL_INITIAL (d) | |
2258 | && TREE_CODE (DECL_INITIAL (d)) == CONSTRUCTOR) | |
2259 | { | |
2260 | tree i = int_const_binop (TRUNC_DIV_EXPR, TREE_OPERAND (fun, 1), | |
2261 | TYPE_SIZE_UNIT (vtable_entry_type)); | |
2262 | HOST_WIDE_INT idx = find_array_ctor_elt (DECL_INITIAL (d), i); | |
2263 | if (idx >= 0) | |
2264 | { | |
2265 | tree fdesc | |
2266 | = (*CONSTRUCTOR_ELTS (DECL_INITIAL (d)))[idx].value; | |
2267 | if (TREE_CODE (fdesc) == FDESC_EXPR | |
2268 | && integer_zerop (TREE_OPERAND (fdesc, 1))) | |
2269 | fun = TREE_OPERAND (fdesc, 0); | |
2270 | } | |
2271 | } | |
2272 | } | |
2d76680f PC |
2273 | } |
2274 | if (TREE_CODE (fun) != FUNCTION_DECL) | |
2275 | { | |
2b3ab879 | 2276 | if (!ctx->quiet && !*non_constant_p) |
84fa214d | 2277 | error_at (loc, "expression %qE does not designate a %<constexpr%> " |
2d76680f PC |
2278 | "function", fun); |
2279 | *non_constant_p = true; | |
2280 | return t; | |
2281 | } | |
2282 | if (DECL_CLONED_FUNCTION_P (fun)) | |
2283 | fun = DECL_CLONED_FUNCTION (fun); | |
0b274c17 MP |
2284 | |
2285 | if (is_ubsan_builtin_p (fun)) | |
2286 | return void_node; | |
2287 | ||
3d78e008 | 2288 | if (fndecl_built_in_p (fun)) |
5756d0f9 | 2289 | return cxx_eval_builtin_function_call (ctx, t, fun, |
92a596e8 | 2290 | lval, non_constant_p, overflow_p); |
e6321c45 JM |
2291 | if (DECL_THUNK_P (fun)) |
2292 | return cxx_eval_thunk_call (ctx, t, fun, lval, non_constant_p, overflow_p); | |
2d76680f PC |
2293 | if (!DECL_DECLARED_CONSTEXPR_P (fun)) |
2294 | { | |
8412b939 JJ |
2295 | if (TREE_CODE (t) == CALL_EXPR |
2296 | && cxx_replaceable_global_alloc_fn (fun) | |
2297 | && (CALL_FROM_NEW_OR_DELETE_P (t) | |
2298 | || (ctx->call | |
2299 | && ctx->call->fundef | |
2300 | && is_std_allocator_allocate (ctx->call->fundef->decl)))) | |
8e007055 JJ |
2301 | { |
2302 | const int nargs = call_expr_nargs (t); | |
2303 | tree arg0 = NULL_TREE; | |
2304 | for (int i = 0; i < nargs; ++i) | |
2305 | { | |
2306 | tree arg = CALL_EXPR_ARG (t, i); | |
2307 | arg = cxx_eval_constant_expression (ctx, arg, false, | |
2308 | non_constant_p, overflow_p); | |
2309 | VERIFY_CONSTANT (arg); | |
2310 | if (i == 0) | |
2311 | arg0 = arg; | |
2312 | } | |
2313 | gcc_assert (arg0); | |
2314 | if (IDENTIFIER_NEW_OP_P (DECL_NAME (fun))) | |
2315 | { | |
2316 | tree type = build_array_type_nelts (char_type_node, | |
2317 | tree_to_uhwi (arg0)); | |
815baade JJ |
2318 | tree var = build_decl (loc, VAR_DECL, |
2319 | (IDENTIFIER_OVL_OP_FLAGS (DECL_NAME (fun)) | |
2320 | & OVL_OP_FLAG_VEC) | |
2321 | ? heap_vec_uninit_identifier | |
2322 | : heap_uninit_identifier, | |
8e007055 JJ |
2323 | type); |
2324 | DECL_ARTIFICIAL (var) = 1; | |
2325 | TREE_STATIC (var) = 1; | |
2326 | ctx->global->heap_vars.safe_push (var); | |
2327 | ctx->global->values.put (var, NULL_TREE); | |
2328 | return fold_convert (ptr_type_node, build_address (var)); | |
2329 | } | |
2330 | else | |
2331 | { | |
2332 | STRIP_NOPS (arg0); | |
2333 | if (TREE_CODE (arg0) == ADDR_EXPR | |
2334 | && VAR_P (TREE_OPERAND (arg0, 0))) | |
2335 | { | |
2336 | tree var = TREE_OPERAND (arg0, 0); | |
2337 | if (DECL_NAME (var) == heap_uninit_identifier | |
2338 | || DECL_NAME (var) == heap_identifier) | |
2339 | { | |
815baade JJ |
2340 | if (IDENTIFIER_OVL_OP_FLAGS (DECL_NAME (fun)) |
2341 | & OVL_OP_FLAG_VEC) | |
2342 | { | |
2343 | if (!ctx->quiet) | |
2344 | { | |
2345 | error_at (loc, "array deallocation of object " | |
2346 | "allocated with non-array " | |
2347 | "allocation"); | |
2348 | inform (DECL_SOURCE_LOCATION (var), | |
2349 | "allocation performed here"); | |
2350 | } | |
2351 | *non_constant_p = true; | |
2352 | return t; | |
2353 | } | |
2354 | DECL_NAME (var) = heap_deleted_identifier; | |
2355 | ctx->global->values.remove (var); | |
2356 | ctx->global->heap_dealloc_count++; | |
2357 | return void_node; | |
2358 | } | |
2359 | else if (DECL_NAME (var) == heap_vec_uninit_identifier | |
2360 | || DECL_NAME (var) == heap_vec_identifier) | |
2361 | { | |
2362 | if ((IDENTIFIER_OVL_OP_FLAGS (DECL_NAME (fun)) | |
2363 | & OVL_OP_FLAG_VEC) == 0) | |
2364 | { | |
2365 | if (!ctx->quiet) | |
2366 | { | |
2367 | error_at (loc, "non-array deallocation of " | |
2368 | "object allocated with array " | |
2369 | "allocation"); | |
2370 | inform (DECL_SOURCE_LOCATION (var), | |
2371 | "allocation performed here"); | |
2372 | } | |
2373 | *non_constant_p = true; | |
2374 | return t; | |
2375 | } | |
8e007055 JJ |
2376 | DECL_NAME (var) = heap_deleted_identifier; |
2377 | ctx->global->values.remove (var); | |
f74f6092 | 2378 | ctx->global->heap_dealloc_count++; |
8e007055 JJ |
2379 | return void_node; |
2380 | } | |
2381 | else if (DECL_NAME (var) == heap_deleted_identifier) | |
2382 | { | |
2383 | if (!ctx->quiet) | |
2384 | error_at (loc, "deallocation of already deallocated " | |
2385 | "storage"); | |
2386 | *non_constant_p = true; | |
2387 | return t; | |
2388 | } | |
2389 | } | |
2390 | if (!ctx->quiet) | |
2391 | error_at (loc, "deallocation of storage that was " | |
2392 | "not previously allocated"); | |
2393 | *non_constant_p = true; | |
2394 | return t; | |
2395 | } | |
2396 | } | |
cf650568 JJ |
2397 | /* Allow placement new in std::construct_at, just return the second |
2398 | argument. */ | |
8412b939 JJ |
2399 | if (TREE_CODE (t) == CALL_EXPR |
2400 | && cxx_placement_new_fn (fun) | |
cf650568 JJ |
2401 | && ctx->call |
2402 | && ctx->call->fundef | |
2403 | && is_std_construct_at (ctx->call->fundef->decl)) | |
2404 | { | |
2405 | const int nargs = call_expr_nargs (t); | |
2406 | tree arg1 = NULL_TREE; | |
2407 | for (int i = 0; i < nargs; ++i) | |
2408 | { | |
2409 | tree arg = CALL_EXPR_ARG (t, i); | |
2410 | arg = cxx_eval_constant_expression (ctx, arg, false, | |
2411 | non_constant_p, overflow_p); | |
cf650568 JJ |
2412 | if (i == 1) |
2413 | arg1 = arg; | |
2805fcb3 JJ |
2414 | else |
2415 | VERIFY_CONSTANT (arg); | |
cf650568 JJ |
2416 | } |
2417 | gcc_assert (arg1); | |
2418 | return arg1; | |
2419 | } | |
22edf943 MP |
2420 | else if (cxx_dynamic_cast_fn_p (fun)) |
2421 | return cxx_eval_dynamic_cast_fn (ctx, t, non_constant_p, overflow_p); | |
2422 | ||
2b3ab879 | 2423 | if (!ctx->quiet) |
2d76680f | 2424 | { |
11399477 | 2425 | if (!lambda_static_thunk_p (fun)) |
84fa214d | 2426 | error_at (loc, "call to non-%<constexpr%> function %qD", fun); |
2d76680f PC |
2427 | explain_invalid_constexpr_fn (fun); |
2428 | } | |
2429 | *non_constant_p = true; | |
2430 | return t; | |
2431 | } | |
2432 | ||
86461cad JM |
2433 | constexpr_ctx new_ctx = *ctx; |
2434 | if (DECL_CONSTRUCTOR_P (fun) && !ctx->object | |
2435 | && TREE_CODE (t) == AGGR_INIT_EXPR) | |
2436 | { | |
2437 | /* We want to have an initialization target for an AGGR_INIT_EXPR. | |
2438 | If we don't already have one in CTX, use the AGGR_INIT_EXPR_SLOT. */ | |
2439 | new_ctx.object = AGGR_INIT_EXPR_SLOT (t); | |
2440 | tree ctor = new_ctx.ctor = build_constructor (DECL_CONTEXT (fun), NULL); | |
e8c48716 | 2441 | CONSTRUCTOR_NO_CLEARING (ctor) = true; |
8e007055 | 2442 | ctx->global->values.put (new_ctx.object, ctor); |
86461cad JM |
2443 | ctx = &new_ctx; |
2444 | } | |
2445 | ||
2d76680f PC |
2446 | /* Shortcut trivial constructor/op=. */ |
2447 | if (trivial_fn_p (fun)) | |
2448 | { | |
86461cad | 2449 | tree init = NULL_TREE; |
2d76680f | 2450 | if (call_expr_nargs (t) == 2) |
86461cad | 2451 | init = convert_from_reference (get_nth_callarg (t, 1)); |
2d76680f PC |
2452 | else if (TREE_CODE (t) == AGGR_INIT_EXPR |
2453 | && AGGR_INIT_ZERO_FIRST (t)) | |
86461cad JM |
2454 | init = build_zero_init (DECL_CONTEXT (fun), NULL_TREE, false); |
2455 | if (init) | |
2456 | { | |
2457 | tree op = get_nth_callarg (t, 0); | |
2458 | if (is_dummy_object (op)) | |
2459 | op = ctx->object; | |
2460 | else | |
2461 | op = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (op)), op); | |
2462 | tree set = build2 (MODIFY_EXPR, TREE_TYPE (op), op, init); | |
c8816908 JM |
2463 | new_ctx.call = &new_call; |
2464 | return cxx_eval_constant_expression (&new_ctx, set, lval, | |
86461cad JM |
2465 | non_constant_p, overflow_p); |
2466 | } | |
2d76680f PC |
2467 | } |
2468 | ||
81371eff JM |
2469 | /* We can't defer instantiating the function any longer. */ |
2470 | if (!DECL_INITIAL (fun) | |
f65a3299 PP |
2471 | && DECL_TEMPLOID_INSTANTIATION (fun) |
2472 | && !uid_sensitive_constexpr_evaluation_p ()) | |
81371eff | 2473 | { |
f065303f JM |
2474 | location_t save_loc = input_location; |
2475 | input_location = loc; | |
81371eff JM |
2476 | ++function_depth; |
2477 | instantiate_decl (fun, /*defer_ok*/false, /*expl_inst*/false); | |
2478 | --function_depth; | |
f065303f | 2479 | input_location = save_loc; |
81371eff JM |
2480 | } |
2481 | ||
2d76680f | 2482 | /* If in direct recursive call, optimize definition search. */ |
c8816908 | 2483 | if (ctx && ctx->call && ctx->call->fundef && ctx->call->fundef->decl == fun) |
3e605b20 | 2484 | new_call.fundef = ctx->call->fundef; |
2d76680f PC |
2485 | else |
2486 | { | |
2487 | new_call.fundef = retrieve_constexpr_fundef (fun); | |
4ddcdbf9 | 2488 | if (new_call.fundef == NULL || new_call.fundef->body == NULL |
4f05d85a | 2489 | || new_call.fundef->result == error_mark_node |
4ddcdbf9 | 2490 | || fun == current_function_decl) |
2d76680f | 2491 | { |
2b3ab879 | 2492 | if (!ctx->quiet) |
2d76680f | 2493 | { |
4ddcdbf9 JM |
2494 | /* We need to check for current_function_decl here in case we're |
2495 | being called during cp_fold_function, because at that point | |
2496 | DECL_INITIAL is set properly and we have a fundef but we | |
2497 | haven't lowered invisirefs yet (c++/70344). */ | |
2498 | if (DECL_INITIAL (fun) == error_mark_node | |
2499 | || fun == current_function_decl) | |
ddd6d421 JM |
2500 | error_at (loc, "%qD called in a constant expression before its " |
2501 | "definition is complete", fun); | |
2502 | else if (DECL_INITIAL (fun)) | |
2d76680f | 2503 | { |
98e5a19a JM |
2504 | /* The definition of fun was somehow unsuitable. But pretend |
2505 | that lambda static thunks don't exist. */ | |
2506 | if (!lambda_static_thunk_p (fun)) | |
2507 | error_at (loc, "%qD called in a constant expression", fun); | |
2d76680f PC |
2508 | explain_invalid_constexpr_fn (fun); |
2509 | } | |
2510 | else | |
2511 | error_at (loc, "%qD used before its definition", fun); | |
2512 | } | |
2513 | *non_constant_p = true; | |
2514 | return t; | |
2515 | } | |
2516 | } | |
60813a46 | 2517 | |
12d9ce19 | 2518 | bool non_constant_args = false; |
3e605b20 | 2519 | cxx_bind_parameters_in_call (ctx, t, &new_call, |
12d9ce19 | 2520 | non_constant_p, overflow_p, &non_constant_args); |
ecdcd560 JM |
2521 | |
2522 | /* We build up the bindings list before we know whether we already have this | |
2523 | call cached. If we don't end up saving these bindings, ggc_free them when | |
2524 | this function exits. */ | |
6c1dae73 | 2525 | class free_bindings |
ecdcd560 | 2526 | { |
4953b790 | 2527 | tree *bindings; |
6c1dae73 | 2528 | public: |
4953b790 JM |
2529 | free_bindings (tree &b): bindings (&b) { } |
2530 | ~free_bindings () { if (bindings) ggc_free (*bindings); } | |
2531 | void preserve () { bindings = NULL; } | |
ecdcd560 JM |
2532 | } fb (new_call.bindings); |
2533 | ||
2d76680f PC |
2534 | if (*non_constant_p) |
2535 | return t; | |
2536 | ||
2537 | depth_ok = push_cx_call_context (t); | |
2538 | ||
caf17f3a | 2539 | /* Remember the object we are constructing or destructing. */ |
04e1749c | 2540 | tree new_obj = NULL_TREE; |
caf17f3a | 2541 | if (DECL_CONSTRUCTOR_P (fun) || DECL_DESTRUCTOR_P (fun)) |
04e1749c | 2542 | { |
caf17f3a | 2543 | /* In a cdtor, it should be the first `this' argument. |
04e1749c MP |
2544 | At this point it has already been evaluated in the call |
2545 | to cxx_bind_parameters_in_call. */ | |
2546 | new_obj = TREE_VEC_ELT (new_call.bindings, 0); | |
2547 | STRIP_NOPS (new_obj); | |
2548 | if (TREE_CODE (new_obj) == ADDR_EXPR) | |
2549 | new_obj = TREE_OPERAND (new_obj, 0); | |
64da1b76 PP |
2550 | |
2551 | if (ctx->call && ctx->call->fundef | |
2552 | && DECL_CONSTRUCTOR_P (ctx->call->fundef->decl)) | |
2553 | { | |
2554 | tree cur_obj = TREE_VEC_ELT (ctx->call->bindings, 0); | |
2555 | STRIP_NOPS (cur_obj); | |
2556 | if (TREE_CODE (cur_obj) == ADDR_EXPR) | |
2557 | cur_obj = TREE_OPERAND (cur_obj, 0); | |
2558 | if (new_obj == cur_obj) | |
2559 | /* We're calling the target constructor of a delegating | |
2560 | constructor, or accessing a base subobject through a | |
2561 | NOP_EXPR as part of a call to a base constructor, so | |
2562 | there is no new (sub)object. */ | |
2563 | new_obj = NULL_TREE; | |
2564 | } | |
04e1749c MP |
2565 | } |
2566 | ||
12d9ce19 | 2567 | tree result = NULL_TREE; |
2d76680f | 2568 | |
12d9ce19 | 2569 | constexpr_call *entry = NULL; |
4a58d2fe | 2570 | if (depth_ok && !non_constant_args && ctx->strict) |
2d76680f | 2571 | { |
cce3ae91 JJ |
2572 | new_call.hash = constexpr_fundef_hasher::hash (new_call.fundef); |
2573 | new_call.hash | |
2574 | = iterative_hash_template_arg (new_call.bindings, new_call.hash); | |
2575 | new_call.hash | |
13de99bc | 2576 | = iterative_hash_object (ctx->manifestly_const_eval, new_call.hash); |
12d9ce19 JM |
2577 | |
2578 | /* If we have seen this call before, we are done. */ | |
2579 | maybe_initialize_constexpr_call_table (); | |
2580 | constexpr_call **slot | |
2581 | = constexpr_call_table->find_slot (&new_call, INSERT); | |
2582 | entry = *slot; | |
2583 | if (entry == NULL) | |
2584 | { | |
7ffc7de5 JM |
2585 | /* Only cache up to constexpr_cache_depth to limit memory use. */ |
2586 | if (depth_ok < constexpr_cache_depth) | |
2587 | { | |
2588 | /* We need to keep a pointer to the entry, not just the slot, as | |
2589 | the slot can move during evaluation of the body. */ | |
2590 | *slot = entry = ggc_alloc<constexpr_call> (); | |
2591 | *entry = new_call; | |
2592 | fb.preserve (); | |
2593 | } | |
12d9ce19 | 2594 | } |
7ffc7de5 JM |
2595 | /* Calls that are in progress have their result set to NULL, so that we |
2596 | can detect circular dependencies. Now that we only cache up to | |
2597 | constexpr_cache_depth this won't catch circular dependencies that | |
2598 | start deeper, but they'll hit the recursion or ops limit. */ | |
12d9ce19 JM |
2599 | else if (entry->result == NULL) |
2600 | { | |
2601 | if (!ctx->quiet) | |
2602 | error ("call has circular dependency"); | |
2603 | *non_constant_p = true; | |
2604 | entry->result = result = error_mark_node; | |
2605 | } | |
2606 | else | |
2607 | result = entry->result; | |
2d76680f PC |
2608 | } |
2609 | ||
2610 | if (!depth_ok) | |
2611 | { | |
2b3ab879 | 2612 | if (!ctx->quiet) |
84fa214d | 2613 | error ("%<constexpr%> evaluation depth exceeds maximum of %d (use " |
7e7a6ed7 | 2614 | "%<-fconstexpr-depth=%> to increase the maximum)", |
2d76680f PC |
2615 | max_constexpr_depth); |
2616 | *non_constant_p = true; | |
12d9ce19 | 2617 | result = error_mark_node; |
2d76680f PC |
2618 | } |
2619 | else | |
2620 | { | |
f74f6092 | 2621 | bool cacheable = true; |
de54de93 JM |
2622 | if (result && result != error_mark_node) |
2623 | /* OK */; | |
2624 | else if (!DECL_SAVED_TREE (fun)) | |
2625 | { | |
2626 | /* When at_eof >= 2, cgraph has started throwing away | |
2627 | DECL_SAVED_TREE, so fail quietly. FIXME we get here because of | |
2628 | late code generation for VEC_INIT_EXPR, which needs to be | |
2629 | completely reconsidered. */ | |
2630 | gcc_assert (at_eof >= 2 && ctx->quiet); | |
2631 | *non_constant_p = true; | |
2632 | } | |
f65a3299 | 2633 | else if (tree copy = get_fundef_copy (new_call.fundef)) |
3e605b20 | 2634 | { |
c0daf32d | 2635 | tree body, parms, res; |
620adbec | 2636 | releasing_vec ctors; |
0567dcd2 | 2637 | |
c0daf32d | 2638 | /* Reuse or create a new unshared copy of this function's body. */ |
97f3003f JM |
2639 | body = TREE_PURPOSE (copy); |
2640 | parms = TREE_VALUE (copy); | |
2641 | res = TREE_TYPE (copy); | |
0567dcd2 MP |
2642 | |
2643 | /* Associate the bindings with the remapped parms. */ | |
2644 | tree bound = new_call.bindings; | |
2645 | tree remapped = parms; | |
3c961dc7 | 2646 | for (int i = 0; i < TREE_VEC_LENGTH (bound); ++i) |
60813a46 | 2647 | { |
3c961dc7 | 2648 | tree arg = TREE_VEC_ELT (bound, i); |
4953b790 JM |
2649 | if (entry) |
2650 | { | |
2651 | /* Unshare args going into the hash table to separate them | |
2652 | from the caller's context, for better GC and to avoid | |
2653 | problems with verify_gimple. */ | |
db38a029 | 2654 | arg = unshare_expr_without_location (arg); |
4953b790 | 2655 | TREE_VEC_ELT (bound, i) = arg; |
5afd90c5 JJ |
2656 | |
2657 | /* And then unshare again so the callee doesn't change the | |
2658 | argument values in the hash table. XXX Could we unshare | |
2659 | lazily in cxx_eval_store_expression? */ | |
2660 | arg = unshare_constructor (arg); | |
2661 | if (TREE_CODE (arg) == CONSTRUCTOR) | |
2662 | vec_safe_push (ctors, arg); | |
4953b790 | 2663 | } |
8e007055 | 2664 | ctx->global->values.put (remapped, arg); |
0567dcd2 | 2665 | remapped = DECL_CHAIN (remapped); |
60813a46 | 2666 | } |
0567dcd2 | 2667 | /* Add the RESULT_DECL to the values map, too. */ |
cd3ca6cb JM |
2668 | gcc_assert (!DECL_BY_REFERENCE (res)); |
2669 | ctx->global->values.put (res, NULL_TREE); | |
60813a46 | 2670 | |
ee1de08d JJ |
2671 | /* Track the callee's evaluated SAVE_EXPRs and TARGET_EXPRs so that |
2672 | we can forget their values after the call. */ | |
c0daf32d | 2673 | constexpr_ctx ctx_with_save_exprs = *ctx; |
0ee28590 | 2674 | auto_vec<tree, 10> save_exprs; |
c0daf32d | 2675 | ctx_with_save_exprs.save_exprs = &save_exprs; |
1e163090 | 2676 | ctx_with_save_exprs.call = &new_call; |
f74f6092 JJ |
2677 | unsigned save_heap_alloc_count = ctx->global->heap_vars.length (); |
2678 | unsigned save_heap_dealloc_count = ctx->global->heap_dealloc_count; | |
c0daf32d | 2679 | |
caf17f3a MP |
2680 | /* If this is a constexpr destructor, the object's const and volatile |
2681 | semantics are no longer in effect; see [class.dtor]p5. */ | |
2682 | if (new_obj && DECL_DESTRUCTOR_P (fun)) | |
2683 | cxx_set_object_constness (ctx, new_obj, /*readonly_p=*/false, | |
2684 | non_constant_p, overflow_p); | |
2685 | ||
0567dcd2 | 2686 | tree jump_target = NULL_TREE; |
c0daf32d | 2687 | cxx_eval_constant_expression (&ctx_with_save_exprs, body, |
0567dcd2 MP |
2688 | lval, non_constant_p, overflow_p, |
2689 | &jump_target); | |
60813a46 | 2690 | |
0567dcd2 MP |
2691 | if (DECL_CONSTRUCTOR_P (fun)) |
2692 | /* This can be null for a subobject constructor call, in | |
2693 | which case what we care about is the initialization | |
2694 | side-effects rather than the value. We could get at the | |
2695 | value by evaluating *this, but we don't bother; there's | |
2696 | no need to put such a call in the hash table. */ | |
2697 | result = lval ? ctx->object : ctx->ctor; | |
2698 | else if (VOID_TYPE_P (TREE_TYPE (res))) | |
2699 | result = void_node; | |
2700 | else | |
2701 | { | |
cd3ca6cb | 2702 | result = *ctx->global->values.get (res); |
0567dcd2 | 2703 | if (result == NULL_TREE && !*non_constant_p) |
60813a46 | 2704 | { |
0567dcd2 | 2705 | if (!ctx->quiet) |
84fa214d | 2706 | error ("%<constexpr%> call flows off the end " |
0567dcd2 MP |
2707 | "of the function"); |
2708 | *non_constant_p = true; | |
60813a46 | 2709 | } |
60813a46 | 2710 | } |
0567dcd2 | 2711 | |
04e1749c MP |
2712 | /* At this point, the object's constructor will have run, so |
2713 | the object is no longer under construction, and its possible | |
2714 | 'const' semantics now apply. Make a note of this fact by | |
2715 | marking the CONSTRUCTOR TREE_READONLY. */ | |
caf17f3a MP |
2716 | if (new_obj && DECL_CONSTRUCTOR_P (fun)) |
2717 | cxx_set_object_constness (ctx, new_obj, /*readonly_p=*/true, | |
2718 | non_constant_p, overflow_p); | |
04e1749c | 2719 | |
ee1de08d JJ |
2720 | /* Forget the saved values of the callee's SAVE_EXPRs and |
2721 | TARGET_EXPRs. */ | |
0ee28590 JJ |
2722 | unsigned int i; |
2723 | tree save_expr; | |
2724 | FOR_EACH_VEC_ELT (save_exprs, i, save_expr) | |
8e007055 | 2725 | ctx->global->values.remove (save_expr); |
c0daf32d | 2726 | |
0567dcd2 MP |
2727 | /* Remove the parms/result from the values map. Is it worth |
2728 | bothering to do this when the map itself is only live for | |
2729 | one constexpr evaluation? If so, maybe also clear out | |
2730 | other vars from call, maybe in BIND_EXPR handling? */ | |
8e007055 | 2731 | ctx->global->values.remove (res); |
0567dcd2 | 2732 | for (tree parm = parms; parm; parm = TREE_CHAIN (parm)) |
8e007055 | 2733 | ctx->global->values.remove (parm); |
c0daf32d | 2734 | |
620adbec JM |
2735 | /* Free any parameter CONSTRUCTORs we aren't returning directly. */ |
2736 | while (!ctors->is_empty ()) | |
2737 | { | |
2738 | tree c = ctors->pop (); | |
2739 | if (c != result) | |
2740 | free_constructor (c); | |
2741 | } | |
2742 | ||
c0daf32d PP |
2743 | /* Make the unshared function copy we used available for re-use. */ |
2744 | save_fundef_copy (fun, copy); | |
f74f6092 JJ |
2745 | |
2746 | /* If the call allocated some heap object that hasn't been | |
2747 | deallocated during the call, or if it deallocated some heap | |
2748 | object it has not allocated, the call isn't really stateless | |
2749 | for the constexpr evaluation and should not be cached. | |
2750 | It is fine if the call allocates something and deallocates it | |
2751 | too. */ | |
2752 | if (entry | |
2753 | && (save_heap_alloc_count != ctx->global->heap_vars.length () | |
2754 | || (save_heap_dealloc_count | |
2755 | != ctx->global->heap_dealloc_count))) | |
2756 | { | |
2757 | tree heap_var; | |
2758 | unsigned int i; | |
2759 | if ((ctx->global->heap_vars.length () | |
2760 | - ctx->global->heap_dealloc_count) | |
2761 | != save_heap_alloc_count - save_heap_dealloc_count) | |
2762 | cacheable = false; | |
2763 | else | |
2764 | FOR_EACH_VEC_ELT_FROM (ctx->global->heap_vars, i, heap_var, | |
2765 | save_heap_alloc_count) | |
2766 | if (DECL_NAME (heap_var) != heap_deleted_identifier) | |
2767 | { | |
2768 | cacheable = false; | |
2769 | break; | |
2770 | } | |
2771 | } | |
b2562229 PP |
2772 | |
2773 | /* Rewrite all occurrences of the function's RESULT_DECL with the | |
2774 | current object under construction. */ | |
2775 | if (!*non_constant_p && ctx->object | |
2776 | && AGGREGATE_TYPE_P (TREE_TYPE (res)) | |
2777 | && !is_empty_class (TREE_TYPE (res))) | |
2778 | if (replace_result_decl (&result, res, ctx->object)) | |
2779 | cacheable = false; | |
3e605b20 | 2780 | } |
aaa26bf4 JM |
2781 | else |
2782 | /* Couldn't get a function copy to evaluate. */ | |
2783 | *non_constant_p = true; | |
60813a46 | 2784 | |
2d76680f PC |
2785 | if (result == error_mark_node) |
2786 | *non_constant_p = true; | |
52228180 | 2787 | if (*non_constant_p || *overflow_p) |
12d9ce19 | 2788 | result = error_mark_node; |
0567dcd2 | 2789 | else if (!result) |
60813a46 | 2790 | result = void_node; |
12d9ce19 | 2791 | if (entry) |
f74f6092 | 2792 | entry->result = cacheable ? result : error_mark_node; |
2d76680f PC |
2793 | } |
2794 | ||
7906797e MP |
2795 | /* The result of a constexpr function must be completely initialized. |
2796 | ||
2797 | However, in C++20, a constexpr constructor doesn't necessarily have | |
2798 | to initialize all the fields, so we don't clear CONSTRUCTOR_NO_CLEARING | |
2799 | in order to detect reading an unitialized object in constexpr instead | |
2800 | of value-initializing it. (reduced_constant_expression_p is expected to | |
2801 | take care of clearing the flag.) */ | |
2802 | if (TREE_CODE (result) == CONSTRUCTOR | |
b04445d4 | 2803 | && (cxx_dialect < cxx20 |
7906797e | 2804 | || !DECL_CONSTRUCTOR_P (fun))) |
ecc57615 | 2805 | clear_no_implicit_zero (result); |
f64e0c02 | 2806 | |
2d76680f | 2807 | pop_cx_call_context (); |
9b9eb42a | 2808 | return result; |
2d76680f PC |
2809 | } |
2810 | ||
7906797e MP |
2811 | /* Return true if T is a valid constant initializer. If a CONSTRUCTOR |
2812 | initializes all the members, the CONSTRUCTOR_NO_CLEARING flag will be | |
2813 | cleared. | |
2814 | FIXME speed this up, it's taking 16% of compile time on sieve testcase. */ | |
2d76680f PC |
2815 | |
2816 | bool | |
2817 | reduced_constant_expression_p (tree t) | |
2818 | { | |
4930c53e MP |
2819 | if (t == NULL_TREE) |
2820 | return false; | |
2821 | ||
2d76680f PC |
2822 | switch (TREE_CODE (t)) |
2823 | { | |
2824 | case PTRMEM_CST: | |
2825 | /* Even if we can't lower this yet, it's constant. */ | |
2826 | return true; | |
2827 | ||
2828 | case CONSTRUCTOR: | |
2829 | /* And we need to handle PTRMEM_CST wrapped in a CONSTRUCTOR. */ | |
7368cfa4 | 2830 | tree idx, val, field; unsigned HOST_WIDE_INT i; |
e8c48716 | 2831 | if (CONSTRUCTOR_NO_CLEARING (t)) |
6f11ddd8 JM |
2832 | { |
2833 | if (TREE_CODE (TREE_TYPE (t)) == VECTOR_TYPE) | |
2834 | /* An initialized vector would have a VECTOR_CST. */ | |
2835 | return false; | |
b04445d4 | 2836 | else if (cxx_dialect >= cxx20 |
7906797e | 2837 | /* An ARRAY_TYPE doesn't have any TYPE_FIELDS. */ |
b599bf9d | 2838 | && TREE_CODE (TREE_TYPE (t)) == ARRAY_TYPE) |
7906797e | 2839 | field = NULL_TREE; |
b04445d4 | 2840 | else if (cxx_dialect >= cxx20 |
b599bf9d PP |
2841 | && TREE_CODE (TREE_TYPE (t)) == UNION_TYPE) |
2842 | { | |
2843 | if (CONSTRUCTOR_NELTS (t) == 0) | |
2844 | /* An initialized union has a constructor element. */ | |
2845 | return false; | |
2846 | /* And it only initializes one member. */ | |
2847 | field = NULL_TREE; | |
2848 | } | |
6f11ddd8 JM |
2849 | else |
2850 | field = next_initializable_field (TYPE_FIELDS (TREE_TYPE (t))); | |
2851 | } | |
7368cfa4 JM |
2852 | else |
2853 | field = NULL_TREE; | |
2854 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (t), i, idx, val) | |
125db6a1 | 2855 | { |
4930c53e MP |
2856 | /* If VAL is null, we're in the middle of initializing this |
2857 | element. */ | |
7368cfa4 | 2858 | if (!reduced_constant_expression_p (val)) |
125db6a1 | 2859 | return false; |
d6ff2207 MP |
2860 | /* Empty class field may or may not have an initializer. */ |
2861 | for (; field && idx != field; | |
2862 | field = next_initializable_field (DECL_CHAIN (field))) | |
2863 | if (!is_really_empty_class (TREE_TYPE (field), | |
2864 | /*ignore_vptr*/false)) | |
2865 | return false; | |
7368cfa4 | 2866 | if (field) |
d6ff2207 | 2867 | field = next_initializable_field (DECL_CHAIN (field)); |
125db6a1 | 2868 | } |
7906797e MP |
2869 | /* There could be a non-empty field at the end. */ |
2870 | for (; field; field = next_initializable_field (DECL_CHAIN (field))) | |
2871 | if (!is_really_empty_class (TREE_TYPE (field), /*ignore_vptr*/false)) | |
2872 | return false; | |
2873 | if (CONSTRUCTOR_NO_CLEARING (t)) | |
7368cfa4 | 2874 | /* All the fields are initialized. */ |
e8c48716 | 2875 | CONSTRUCTOR_NO_CLEARING (t) = false; |
2d76680f PC |
2876 | return true; |
2877 | ||
2878 | default: | |
2879 | /* FIXME are we calling this too much? */ | |
2880 | return initializer_constant_valid_p (t, TREE_TYPE (t)) != NULL_TREE; | |
2881 | } | |
2882 | } | |
2883 | ||
2884 | /* Some expressions may have constant operands but are not constant | |
7d75ea04 JJ |
2885 | themselves, such as 1/0. Call this function to check for that |
2886 | condition. | |
2d76680f PC |
2887 | |
2888 | We only call this in places that require an arithmetic constant, not in | |
2889 | places where we might have a non-constant expression that can be a | |
2890 | component of a constant expression, such as the address of a constexpr | |
2891 | variable that might be dereferenced later. */ | |
2892 | ||
2893 | static bool | |
2894 | verify_constant (tree t, bool allow_non_constant, bool *non_constant_p, | |
2895 | bool *overflow_p) | |
2896 | { | |
596334fa JM |
2897 | if (!*non_constant_p && !reduced_constant_expression_p (t) |
2898 | && t != void_node) | |
2d76680f PC |
2899 | { |
2900 | if (!allow_non_constant) | |
2901 | error ("%q+E is not a constant expression", t); | |
2902 | *non_constant_p = true; | |
2903 | } | |
2904 | if (TREE_OVERFLOW_P (t)) | |
2905 | { | |
2906 | if (!allow_non_constant) | |
2907 | { | |
2908 | permerror (input_location, "overflow in constant expression"); | |
2909 | /* If we're being permissive (and are in an enforcing | |
2910 | context), ignore the overflow. */ | |
2911 | if (flag_permissive) | |
2912 | return *non_constant_p; | |
2913 | } | |
2914 | *overflow_p = true; | |
2915 | } | |
2916 | return *non_constant_p; | |
2917 | } | |
2918 | ||
253a921b MP |
2919 | /* Check whether the shift operation with code CODE and type TYPE on LHS |
2920 | and RHS is undefined. If it is, give an error with an explanation, | |
2921 | and return true; return false otherwise. */ | |
2922 | ||
2923 | static bool | |
2924 | cxx_eval_check_shift_p (location_t loc, const constexpr_ctx *ctx, | |
2925 | enum tree_code code, tree type, tree lhs, tree rhs) | |
2926 | { | |
2927 | if ((code != LSHIFT_EXPR && code != RSHIFT_EXPR) | |
2928 | || TREE_CODE (lhs) != INTEGER_CST | |
2929 | || TREE_CODE (rhs) != INTEGER_CST) | |
2930 | return false; | |
2931 | ||
2932 | tree lhstype = TREE_TYPE (lhs); | |
2933 | unsigned HOST_WIDE_INT uprec = TYPE_PRECISION (TREE_TYPE (lhs)); | |
2934 | ||
2935 | /* [expr.shift] The behavior is undefined if the right operand | |
2936 | is negative, or greater than or equal to the length in bits | |
2937 | of the promoted left operand. */ | |
2938 | if (tree_int_cst_sgn (rhs) == -1) | |
2939 | { | |
2940 | if (!ctx->quiet) | |
5342156c MP |
2941 | permerror (loc, "right operand of shift expression %q+E is negative", |
2942 | build2_loc (loc, code, type, lhs, rhs)); | |
2943 | return (!flag_permissive || ctx->quiet); | |
253a921b MP |
2944 | } |
2945 | if (compare_tree_int (rhs, uprec) >= 0) | |
2946 | { | |
2947 | if (!ctx->quiet) | |
a9c697b8 MS |
2948 | permerror (loc, "right operand of shift expression %q+E is greater " |
2949 | "than or equal to the precision %wu of the left operand", | |
2950 | build2_loc (loc, code, type, lhs, rhs), uprec); | |
5342156c | 2951 | return (!flag_permissive || ctx->quiet); |
253a921b MP |
2952 | } |
2953 | ||
2954 | /* The value of E1 << E2 is E1 left-shifted E2 bit positions; [...] | |
2955 | if E1 has a signed type and non-negative value, and E1x2^E2 is | |
2956 | representable in the corresponding unsigned type of the result type, | |
2957 | then that value, converted to the result type, is the resulting value; | |
8ee09943 | 2958 | otherwise, the behavior is undefined. |
b04445d4 | 2959 | For C++20: |
8ee09943 JJ |
2960 | The value of E1 << E2 is the unique value congruent to E1 x 2^E2 modulo |
2961 | 2^N, where N is the range exponent of the type of the result. */ | |
2962 | if (code == LSHIFT_EXPR | |
2963 | && !TYPE_UNSIGNED (lhstype) | |
2964 | && cxx_dialect >= cxx11 | |
b04445d4 | 2965 | && cxx_dialect < cxx20) |
253a921b MP |
2966 | { |
2967 | if (tree_int_cst_sgn (lhs) == -1) | |
2968 | { | |
2969 | if (!ctx->quiet) | |
5342156c MP |
2970 | permerror (loc, |
2971 | "left operand of shift expression %q+E is negative", | |
2972 | build2_loc (loc, code, type, lhs, rhs)); | |
2973 | return (!flag_permissive || ctx->quiet); | |
253a921b MP |
2974 | } |
2975 | /* For signed x << y the following: | |
2976 | (unsigned) x >> ((prec (lhs) - 1) - y) | |
2977 | if > 1, is undefined. The right-hand side of this formula | |
2978 | is the highest bit of the LHS that can be set (starting from 0), | |
2979 | so that the shift doesn't overflow. We then right-shift the LHS | |
2980 | to see whether any other bit is set making the original shift | |
2981 | undefined -- the result is not representable in the corresponding | |
2982 | unsigned type. */ | |
2983 | tree t = build_int_cst (unsigned_type_node, uprec - 1); | |
2984 | t = fold_build2 (MINUS_EXPR, unsigned_type_node, t, rhs); | |
2985 | tree ulhs = fold_convert (unsigned_type_for (lhstype), lhs); | |
2986 | t = fold_build2 (RSHIFT_EXPR, TREE_TYPE (ulhs), ulhs, t); | |
2987 | if (tree_int_cst_lt (integer_one_node, t)) | |
2988 | { | |
2989 | if (!ctx->quiet) | |
5342156c MP |
2990 | permerror (loc, "shift expression %q+E overflows", |
2991 | build2_loc (loc, code, type, lhs, rhs)); | |
2992 | return (!flag_permissive || ctx->quiet); | |
253a921b MP |
2993 | } |
2994 | } | |
2995 | return false; | |
2996 | } | |
2997 | ||
2d76680f PC |
2998 | /* Subroutine of cxx_eval_constant_expression. |
2999 | Attempt to reduce the unary expression tree T to a compile time value. | |
3000 | If successful, return the value. Otherwise issue a diagnostic | |
3001 | and return error_mark_node. */ | |
3002 | ||
3003 | static tree | |
3e605b20 | 3004 | cxx_eval_unary_expression (const constexpr_ctx *ctx, tree t, |
12d9ce19 | 3005 | bool /*lval*/, |
2d76680f PC |
3006 | bool *non_constant_p, bool *overflow_p) |
3007 | { | |
3008 | tree r; | |
3009 | tree orig_arg = TREE_OPERAND (t, 0); | |
12d9ce19 JM |
3010 | tree arg = cxx_eval_constant_expression (ctx, orig_arg, /*lval*/false, |
3011 | non_constant_p, overflow_p); | |
2d76680f | 3012 | VERIFY_CONSTANT (arg); |
f899317e JM |
3013 | location_t loc = EXPR_LOCATION (t); |
3014 | enum tree_code code = TREE_CODE (t); | |
3015 | tree type = TREE_TYPE (t); | |
3016 | r = fold_unary_loc (loc, code, type, arg); | |
3017 | if (r == NULL_TREE) | |
3018 | { | |
3019 | if (arg == orig_arg) | |
3020 | r = t; | |
3021 | else | |
3022 | r = build1_loc (loc, code, type, arg); | |
3023 | } | |
2d76680f PC |
3024 | VERIFY_CONSTANT (r); |
3025 | return r; | |
3026 | } | |
3027 | ||
ea8661cd JJ |
3028 | /* Helper function for cxx_eval_binary_expression. Try to optimize |
3029 | original POINTER_PLUS_EXPR T, LHS p+ RHS, return NULL_TREE if the | |
3030 | generic folding should be used. */ | |
3031 | ||
3032 | static tree | |
3033 | cxx_fold_pointer_plus_expression (const constexpr_ctx *ctx, tree t, | |
3034 | tree lhs, tree rhs, bool *non_constant_p, | |
3035 | bool *overflow_p) | |
3036 | { | |
3037 | STRIP_NOPS (lhs); | |
3038 | if (TREE_CODE (lhs) != ADDR_EXPR) | |
3039 | return NULL_TREE; | |
3040 | ||
3041 | lhs = TREE_OPERAND (lhs, 0); | |
3042 | ||
3043 | /* &A[i] p+ j => &A[i + j] */ | |
3044 | if (TREE_CODE (lhs) == ARRAY_REF | |
3045 | && TREE_CODE (TREE_OPERAND (lhs, 1)) == INTEGER_CST | |
3046 | && TREE_CODE (rhs) == INTEGER_CST | |
3047 | && TYPE_SIZE_UNIT (TREE_TYPE (lhs)) | |
3048 | && TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (lhs))) == INTEGER_CST) | |
3049 | { | |
3050 | tree orig_type = TREE_TYPE (t); | |
3051 | location_t loc = EXPR_LOCATION (t); | |
3052 | tree type = TREE_TYPE (lhs); | |
3053 | ||
3054 | t = fold_convert_loc (loc, ssizetype, TREE_OPERAND (lhs, 1)); | |
3055 | tree nelts = array_type_nelts_top (TREE_TYPE (TREE_OPERAND (lhs, 0))); | |
3056 | nelts = cxx_eval_constant_expression (ctx, nelts, false, non_constant_p, | |
3057 | overflow_p); | |
3058 | if (*non_constant_p) | |
3059 | return NULL_TREE; | |
3060 | /* Don't fold an out-of-bound access. */ | |
3061 | if (!tree_int_cst_le (t, nelts)) | |
3062 | return NULL_TREE; | |
3063 | rhs = cp_fold_convert (ssizetype, rhs); | |
3064 | /* Don't fold if rhs can't be divided exactly by TYPE_SIZE_UNIT. | |
3065 | constexpr int A[1]; ... (char *)&A[0] + 1 */ | |
3066 | if (!integer_zerop (fold_build2_loc (loc, TRUNC_MOD_EXPR, sizetype, | |
3067 | rhs, TYPE_SIZE_UNIT (type)))) | |
3068 | return NULL_TREE; | |
3069 | /* Make sure to treat the second operand of POINTER_PLUS_EXPR | |
3070 | as signed. */ | |
3071 | rhs = fold_build2_loc (loc, EXACT_DIV_EXPR, ssizetype, rhs, | |
3072 | TYPE_SIZE_UNIT (type)); | |
3073 | t = size_binop_loc (loc, PLUS_EXPR, rhs, t); | |
3074 | t = build4_loc (loc, ARRAY_REF, type, TREE_OPERAND (lhs, 0), | |
3075 | t, NULL_TREE, NULL_TREE); | |
3076 | t = cp_build_addr_expr (t, tf_warning_or_error); | |
3077 | t = cp_fold_convert (orig_type, t); | |
3078 | return cxx_eval_constant_expression (ctx, t, /*lval*/false, | |
3079 | non_constant_p, overflow_p); | |
3080 | } | |
3081 | ||
3082 | return NULL_TREE; | |
3083 | } | |
3084 | ||
2d76680f PC |
3085 | /* Subroutine of cxx_eval_constant_expression. |
3086 | Like cxx_eval_unary_expression, except for binary expressions. */ | |
3087 | ||
3088 | static tree | |
3e605b20 | 3089 | cxx_eval_binary_expression (const constexpr_ctx *ctx, tree t, |
dfffecb8 | 3090 | bool lval, |
2d76680f PC |
3091 | bool *non_constant_p, bool *overflow_p) |
3092 | { | |
618d6c1c | 3093 | tree r = NULL_TREE; |
2d76680f PC |
3094 | tree orig_lhs = TREE_OPERAND (t, 0); |
3095 | tree orig_rhs = TREE_OPERAND (t, 1); | |
3096 | tree lhs, rhs; | |
12d9ce19 | 3097 | lhs = cxx_eval_constant_expression (ctx, orig_lhs, /*lval*/false, |
5a804683 | 3098 | non_constant_p, overflow_p); |
c8a66fc9 JM |
3099 | /* Don't VERIFY_CONSTANT here, it's unnecessary and will break pointer |
3100 | subtraction. */ | |
3101 | if (*non_constant_p) | |
3102 | return t; | |
12d9ce19 | 3103 | rhs = cxx_eval_constant_expression (ctx, orig_rhs, /*lval*/false, |
5a804683 | 3104 | non_constant_p, overflow_p); |
c8a66fc9 JM |
3105 | if (*non_constant_p) |
3106 | return t; | |
f899317e JM |
3107 | |
3108 | location_t loc = EXPR_LOCATION (t); | |
3109 | enum tree_code code = TREE_CODE (t); | |
3110 | tree type = TREE_TYPE (t); | |
618d6c1c PP |
3111 | |
3112 | if (code == EQ_EXPR || code == NE_EXPR) | |
3113 | { | |
3114 | bool is_code_eq = (code == EQ_EXPR); | |
3115 | ||
3116 | if (TREE_CODE (lhs) == PTRMEM_CST | |
3117 | && TREE_CODE (rhs) == PTRMEM_CST) | |
9b0607de JM |
3118 | { |
3119 | tree lmem = PTRMEM_CST_MEMBER (lhs); | |
3120 | tree rmem = PTRMEM_CST_MEMBER (rhs); | |
3121 | bool eq; | |
3122 | if (TREE_CODE (lmem) == TREE_CODE (rmem) | |
3123 | && TREE_CODE (lmem) == FIELD_DECL | |
3124 | && TREE_CODE (DECL_CONTEXT (lmem)) == UNION_TYPE | |
3125 | && same_type_p (DECL_CONTEXT (lmem), | |
3126 | DECL_CONTEXT (rmem))) | |
3127 | /* If both refer to (possibly different) members of the same union | |
3128 | (12.3), they compare equal. */ | |
3129 | eq = true; | |
3130 | else | |
3131 | eq = cp_tree_equal (lhs, rhs); | |
3132 | r = constant_boolean_node (eq == is_code_eq, type); | |
3133 | } | |
618d6c1c PP |
3134 | else if ((TREE_CODE (lhs) == PTRMEM_CST |
3135 | || TREE_CODE (rhs) == PTRMEM_CST) | |
3136 | && (null_member_pointer_value_p (lhs) | |
3137 | || null_member_pointer_value_p (rhs))) | |
3138 | r = constant_boolean_node (!is_code_eq, type); | |
dd5dda56 JM |
3139 | else if (TREE_CODE (lhs) == PTRMEM_CST) |
3140 | lhs = cplus_expand_constant (lhs); | |
3141 | else if (TREE_CODE (rhs) == PTRMEM_CST) | |
3142 | rhs = cplus_expand_constant (rhs); | |
618d6c1c | 3143 | } |
8bada5cd MS |
3144 | if (code == POINTER_PLUS_EXPR && !*non_constant_p |
3145 | && integer_zerop (lhs) && !integer_zerop (rhs)) | |
3146 | { | |
3147 | if (!ctx->quiet) | |
3148 | error ("arithmetic involving a null pointer in %qE", lhs); | |
bf533db8 | 3149 | *non_constant_p = true; |
8bada5cd MS |
3150 | return t; |
3151 | } | |
ea8661cd JJ |
3152 | else if (code == POINTER_PLUS_EXPR) |
3153 | r = cxx_fold_pointer_plus_expression (ctx, t, lhs, rhs, non_constant_p, | |
3154 | overflow_p); | |
b7689b96 JM |
3155 | else if (code == SPACESHIP_EXPR) |
3156 | { | |
3157 | r = genericize_spaceship (type, lhs, rhs); | |
5c64df80 JJ |
3158 | return cxx_eval_constant_expression (ctx, r, lval, non_constant_p, |
3159 | overflow_p); | |
b7689b96 | 3160 | } |
618d6c1c PP |
3161 | |
3162 | if (r == NULL_TREE) | |
3163 | r = fold_binary_loc (loc, code, type, lhs, rhs); | |
3164 | ||
4866b2f5 JJ |
3165 | if (r == NULL_TREE |
3166 | && (code == LSHIFT_EXPR || code == RSHIFT_EXPR) | |
3167 | && TREE_CODE (lhs) == INTEGER_CST | |
3168 | && TREE_CODE (rhs) == INTEGER_CST | |
3169 | && wi::neg_p (wi::to_wide (rhs))) | |
3170 | { | |
3171 | /* For diagnostics and -fpermissive emulate previous behavior of | |
3172 | handling shifts by negative amount. */ | |
3173 | tree nrhs = const_unop (NEGATE_EXPR, TREE_TYPE (rhs), rhs); | |
3174 | if (nrhs) | |
3175 | r = fold_binary_loc (loc, | |
3176 | code == LSHIFT_EXPR ? RSHIFT_EXPR : LSHIFT_EXPR, | |
3177 | type, lhs, nrhs); | |
3178 | } | |
3179 | ||
f899317e JM |
3180 | if (r == NULL_TREE) |
3181 | { | |
3182 | if (lhs == orig_lhs && rhs == orig_rhs) | |
3183 | r = t; | |
3184 | else | |
3185 | r = build2_loc (loc, code, type, lhs, rhs); | |
3186 | } | |
253a921b MP |
3187 | else if (cxx_eval_check_shift_p (loc, ctx, code, type, lhs, rhs)) |
3188 | *non_constant_p = true; | |
c8a66fc9 JM |
3189 | /* Don't VERIFY_CONSTANT if this might be dealing with a pointer to |
3190 | a local array in a constexpr function. */ | |
71a93b08 | 3191 | bool ptr = INDIRECT_TYPE_P (TREE_TYPE (lhs)); |
caee690e | 3192 | if (!ptr) |
134efa82 | 3193 | VERIFY_CONSTANT (r); |
2d76680f PC |
3194 | return r; |
3195 | } | |
3196 | ||
3197 | /* Subroutine of cxx_eval_constant_expression. | |
3198 | Attempt to evaluate condition expressions. Dead branches are not | |
3199 | looked into. */ | |
3200 | ||
3201 | static tree | |
3e605b20 | 3202 | cxx_eval_conditional_expression (const constexpr_ctx *ctx, tree t, |
92a596e8 | 3203 | bool lval, |
56632b27 JM |
3204 | bool *non_constant_p, bool *overflow_p, |
3205 | tree *jump_target) | |
2d76680f | 3206 | { |
3e605b20 | 3207 | tree val = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), |
12d9ce19 | 3208 | /*lval*/false, |
5a804683 | 3209 | non_constant_p, overflow_p); |
2d76680f PC |
3210 | VERIFY_CONSTANT (val); |
3211 | /* Don't VERIFY_CONSTANT the other operands. */ | |
3212 | if (integer_zerop (val)) | |
43574e4f JJ |
3213 | val = TREE_OPERAND (t, 2); |
3214 | else | |
3215 | val = TREE_OPERAND (t, 1); | |
3216 | if (TREE_CODE (t) == IF_STMT && !val) | |
3217 | val = void_node; | |
3218 | return cxx_eval_constant_expression (ctx, val, lval, non_constant_p, | |
3219 | overflow_p, jump_target); | |
2d76680f PC |
3220 | } |
3221 | ||
f370e36d JJ |
3222 | /* Subroutine of cxx_eval_constant_expression. |
3223 | Attempt to evaluate vector condition expressions. Unlike | |
3224 | cxx_eval_conditional_expression, VEC_COND_EXPR acts like a normal | |
3225 | ternary arithmetics operation, where all 3 arguments have to be | |
3226 | evaluated as constants and then folding computes the result from | |
3227 | them. */ | |
3228 | ||
3229 | static tree | |
3230 | cxx_eval_vector_conditional_expression (const constexpr_ctx *ctx, tree t, | |
3231 | bool *non_constant_p, bool *overflow_p) | |
3232 | { | |
3233 | tree arg1 = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), | |
3234 | /*lval*/false, | |
3235 | non_constant_p, overflow_p); | |
3236 | VERIFY_CONSTANT (arg1); | |
3237 | tree arg2 = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), | |
3238 | /*lval*/false, | |
3239 | non_constant_p, overflow_p); | |
3240 | VERIFY_CONSTANT (arg2); | |
3241 | tree arg3 = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 2), | |
3242 | /*lval*/false, | |
3243 | non_constant_p, overflow_p); | |
3244 | VERIFY_CONSTANT (arg3); | |
3245 | location_t loc = EXPR_LOCATION (t); | |
3246 | tree type = TREE_TYPE (t); | |
3247 | tree r = fold_ternary_loc (loc, VEC_COND_EXPR, type, arg1, arg2, arg3); | |
3248 | if (r == NULL_TREE) | |
3249 | { | |
3250 | if (arg1 == TREE_OPERAND (t, 0) | |
3251 | && arg2 == TREE_OPERAND (t, 1) | |
3252 | && arg3 == TREE_OPERAND (t, 2)) | |
3253 | r = t; | |
3254 | else | |
3255 | r = build3_loc (loc, VEC_COND_EXPR, type, arg1, arg2, arg3); | |
3256 | } | |
3257 | VERIFY_CONSTANT (r); | |
3258 | return r; | |
3259 | } | |
3260 | ||
ceaaf873 JM |
3261 | /* Returns less than, equal to, or greater than zero if KEY is found to be |
3262 | less than, to match, or to be greater than the constructor_elt's INDEX. */ | |
3263 | ||
3264 | static int | |
3265 | array_index_cmp (tree key, tree index) | |
3266 | { | |
3267 | gcc_assert (TREE_CODE (key) == INTEGER_CST); | |
3268 | ||
3269 | switch (TREE_CODE (index)) | |
3270 | { | |
3271 | case INTEGER_CST: | |
3272 | return tree_int_cst_compare (key, index); | |
3273 | case RANGE_EXPR: | |
3274 | { | |
3275 | tree lo = TREE_OPERAND (index, 0); | |
3276 | tree hi = TREE_OPERAND (index, 1); | |
3277 | if (tree_int_cst_lt (key, lo)) | |
3278 | return -1; | |
3279 | else if (tree_int_cst_lt (hi, key)) | |
3280 | return 1; | |
3281 | else | |
3282 | return 0; | |
3283 | } | |
3284 | default: | |
3285 | gcc_unreachable (); | |
3286 | } | |
3287 | } | |
3288 | ||
3289 | /* Returns the index of the constructor_elt of ARY which matches DINDEX, or -1 | |
3290 | if none. If INSERT is true, insert a matching element rather than fail. */ | |
3291 | ||
3292 | static HOST_WIDE_INT | |
582d2481 | 3293 | find_array_ctor_elt (tree ary, tree dindex, bool insert) |
ceaaf873 JM |
3294 | { |
3295 | if (tree_int_cst_sgn (dindex) < 0) | |
3296 | return -1; | |
3297 | ||
3298 | unsigned HOST_WIDE_INT i = tree_to_uhwi (dindex); | |
3299 | vec<constructor_elt, va_gc> *elts = CONSTRUCTOR_ELTS (ary); | |
3300 | unsigned HOST_WIDE_INT len = vec_safe_length (elts); | |
3301 | ||
3302 | unsigned HOST_WIDE_INT end = len; | |
3303 | unsigned HOST_WIDE_INT begin = 0; | |
3304 | ||
3305 | /* If the last element of the CONSTRUCTOR has its own index, we can assume | |
3306 | that the same is true of the other elements and index directly. */ | |
3307 | if (end > 0) | |
3308 | { | |
fe217ba0 | 3309 | tree cindex = (*elts)[end - 1].index; |
c7c09af8 JJ |
3310 | if (cindex == NULL_TREE) |
3311 | { | |
3312 | /* Verify that if the last index is missing, all indexes | |
3313 | are missing. */ | |
3314 | if (flag_checking) | |
3315 | for (unsigned int j = 0; j < len - 1; ++j) | |
3316 | gcc_assert ((*elts)[j].index == NULL_TREE); | |
3317 | if (i < end) | |
3318 | return i; | |
3319 | else | |
3320 | { | |
3321 | begin = end; | |
3322 | if (i == end) | |
3323 | /* If the element is to be added right at the end, | |
3324 | make sure it is added with cleared index too. */ | |
3325 | dindex = NULL_TREE; | |
3326 | else if (insert) | |
3327 | /* Otherwise, in order not to break the assumption | |
3328 | that CONSTRUCTOR either has all indexes or none, | |
3329 | we need to add indexes to all elements. */ | |
3330 | for (unsigned int j = 0; j < len; ++j) | |
3331 | (*elts)[j].index = build_int_cst (TREE_TYPE (dindex), j); | |
3332 | } | |
3333 | } | |
3334 | else if (TREE_CODE (cindex) == INTEGER_CST | |
3335 | && compare_tree_int (cindex, end - 1) == 0) | |
ceaaf873 JM |
3336 | { |
3337 | if (i < end) | |
3338 | return i; | |
3339 | else | |
3340 | begin = end; | |
3341 | } | |
3342 | } | |
3343 | ||
3344 | /* Otherwise, find a matching index by means of a binary search. */ | |
3345 | while (begin != end) | |
3346 | { | |
3347 | unsigned HOST_WIDE_INT middle = (begin + end) / 2; | |
a7ccb9e7 JM |
3348 | constructor_elt &elt = (*elts)[middle]; |
3349 | tree idx = elt.index; | |
ceaaf873 | 3350 | |
a7ccb9e7 | 3351 | int cmp = array_index_cmp (dindex, idx); |
ceaaf873 JM |
3352 | if (cmp < 0) |
3353 | end = middle; | |
3354 | else if (cmp > 0) | |
3355 | begin = middle + 1; | |
3356 | else | |
a7ccb9e7 JM |
3357 | { |
3358 | if (insert && TREE_CODE (idx) == RANGE_EXPR) | |
3359 | { | |
3360 | /* We need to split the range. */ | |
3361 | constructor_elt e; | |
3362 | tree lo = TREE_OPERAND (idx, 0); | |
3363 | tree hi = TREE_OPERAND (idx, 1); | |
fe217ba0 JJ |
3364 | tree value = elt.value; |
3365 | dindex = fold_convert (sizetype, dindex); | |
a7ccb9e7 JM |
3366 | if (tree_int_cst_lt (lo, dindex)) |
3367 | { | |
3368 | /* There are still some lower elts; shorten the range. */ | |
3369 | tree new_hi = int_const_binop (MINUS_EXPR, dindex, | |
3370 | size_one_node); | |
3371 | if (tree_int_cst_equal (lo, new_hi)) | |
3372 | /* Only one element left, no longer a range. */ | |
3373 | elt.index = lo; | |
3374 | else | |
3375 | TREE_OPERAND (idx, 1) = new_hi; | |
3376 | /* Append the element we want to insert. */ | |
3377 | ++middle; | |
3378 | e.index = dindex; | |
fe217ba0 | 3379 | e.value = unshare_constructor (value); |
a7ccb9e7 JM |
3380 | vec_safe_insert (CONSTRUCTOR_ELTS (ary), middle, e); |
3381 | } | |
3382 | else | |
3383 | /* No lower elts, the range elt is now ours. */ | |
3384 | elt.index = dindex; | |
3385 | ||
3386 | if (tree_int_cst_lt (dindex, hi)) | |
3387 | { | |
3388 | /* There are still some higher elts; append a range. */ | |
3389 | tree new_lo = int_const_binop (PLUS_EXPR, dindex, | |
3390 | size_one_node); | |
3391 | if (tree_int_cst_equal (new_lo, hi)) | |
3392 | e.index = hi; | |
3393 | else | |
3394 | e.index = build2 (RANGE_EXPR, sizetype, new_lo, hi); | |
fe217ba0 JJ |
3395 | e.value = unshare_constructor (value); |
3396 | vec_safe_insert (CONSTRUCTOR_ELTS (ary), middle + 1, e); | |
a7ccb9e7 JM |
3397 | } |
3398 | } | |
3399 | return middle; | |
3400 | } | |
ceaaf873 JM |
3401 | } |
3402 | ||
3403 | if (insert) | |
3404 | { | |
3405 | constructor_elt e = { dindex, NULL_TREE }; | |
3406 | vec_safe_insert (CONSTRUCTOR_ELTS (ary), end, e); | |
3407 | return end; | |
3408 | } | |
3409 | ||
3410 | return -1; | |
3411 | } | |
3412 | ||
37244b21 PP |
3413 | /* Return a pointer to the constructor_elt of CTOR which matches INDEX. If no |
3414 | matching constructor_elt exists, then add one to CTOR. | |
3415 | ||
3416 | As an optimization, if POS_HINT is non-negative then it is used as a guess | |
3417 | for the (integer) index of the matching constructor_elt within CTOR. */ | |
3418 | ||
3419 | static constructor_elt * | |
077dd9b3 | 3420 | get_or_insert_ctor_field (tree ctor, tree index, int pos_hint = -1) |
37244b21 PP |
3421 | { |
3422 | /* Check the hint first. */ | |
3423 | if (pos_hint >= 0 && (unsigned)pos_hint < CONSTRUCTOR_NELTS (ctor) | |
3424 | && CONSTRUCTOR_ELT (ctor, pos_hint)->index == index) | |
3425 | return CONSTRUCTOR_ELT (ctor, pos_hint); | |
3426 | ||
3427 | tree type = TREE_TYPE (ctor); | |
3428 | if (TREE_CODE (type) == VECTOR_TYPE && index == NULL_TREE) | |
3429 | { | |
3430 | CONSTRUCTOR_APPEND_ELT (CONSTRUCTOR_ELTS (ctor), index, NULL_TREE); | |
3431 | return &CONSTRUCTOR_ELTS (ctor)->last(); | |
3432 | } | |
3433 | else if (TREE_CODE (type) == ARRAY_TYPE || TREE_CODE (type) == VECTOR_TYPE) | |
3434 | { | |
e069285c PP |
3435 | if (TREE_CODE (index) == RANGE_EXPR) |
3436 | { | |
3437 | /* Support for RANGE_EXPR index lookups is currently limited to | |
3438 | accessing an existing element via POS_HINT, or appending a new | |
3439 | element to the end of CTOR. ??? Support for other access | |
3440 | patterns may also be needed. */ | |
3441 | vec<constructor_elt, va_gc> *elts = CONSTRUCTOR_ELTS (ctor); | |
3442 | if (vec_safe_length (elts)) | |
3443 | { | |
3444 | tree lo = TREE_OPERAND (index, 0); | |
3445 | gcc_assert (array_index_cmp (elts->last().index, lo) < 0); | |
3446 | } | |
3447 | CONSTRUCTOR_APPEND_ELT (elts, index, NULL_TREE); | |
3448 | return &elts->last(); | |
3449 | } | |
3450 | ||
37244b21 PP |
3451 | HOST_WIDE_INT i = find_array_ctor_elt (ctor, index, /*insert*/true); |
3452 | gcc_assert (i >= 0); | |
3453 | constructor_elt *cep = CONSTRUCTOR_ELT (ctor, i); | |
3454 | gcc_assert (cep->index == NULL_TREE | |
3455 | || TREE_CODE (cep->index) != RANGE_EXPR); | |
3456 | return cep; | |
3457 | } | |
3458 | else | |
3459 | { | |
3460 | gcc_assert (TREE_CODE (index) == FIELD_DECL); | |
3461 | ||
3462 | /* We must keep the CONSTRUCTOR's ELTS in FIELD order. | |
3463 | Usually we meet initializers in that order, but it is | |
3464 | possible for base types to be placed not in program | |
3465 | order. */ | |
3466 | tree fields = TYPE_FIELDS (DECL_CONTEXT (index)); | |
3467 | unsigned HOST_WIDE_INT idx = 0; | |
3468 | constructor_elt *cep = NULL; | |
3469 | ||
3470 | /* Check if we're changing the active member of a union. */ | |
3471 | if (TREE_CODE (type) == UNION_TYPE && CONSTRUCTOR_NELTS (ctor) | |
3472 | && CONSTRUCTOR_ELT (ctor, 0)->index != index) | |
3473 | vec_safe_truncate (CONSTRUCTOR_ELTS (ctor), 0); | |
3474 | /* If the bit offset of INDEX is larger than that of the last | |
3475 | constructor_elt, then we can just immediately append a new | |
3476 | constructor_elt to the end of CTOR. */ | |
3477 | else if (CONSTRUCTOR_NELTS (ctor) | |
3478 | && tree_int_cst_compare (bit_position (index), | |
3479 | bit_position (CONSTRUCTOR_ELTS (ctor) | |
3480 | ->last().index)) > 0) | |
3481 | { | |
3482 | idx = CONSTRUCTOR_NELTS (ctor); | |
3483 | goto insert; | |
3484 | } | |
3485 | ||
3486 | /* Otherwise, we need to iterate over CTOR to find or insert INDEX | |
3487 | appropriately. */ | |
3488 | ||
3489 | for (; vec_safe_iterate (CONSTRUCTOR_ELTS (ctor), idx, &cep); | |
3490 | idx++, fields = DECL_CHAIN (fields)) | |
3491 | { | |
3492 | if (index == cep->index) | |
3493 | goto found; | |
3494 | ||
3495 | /* The field we're initializing must be on the field | |
3496 | list. Look to see if it is present before the | |
3497 | field the current ELT initializes. */ | |
3498 | for (; fields != cep->index; fields = DECL_CHAIN (fields)) | |
3499 | if (index == fields) | |
3500 | goto insert; | |
3501 | } | |
3502 | /* We fell off the end of the CONSTRUCTOR, so insert a new | |
3503 | entry at the end. */ | |
3504 | ||
3505 | insert: | |
3506 | { | |
3507 | constructor_elt ce = { index, NULL_TREE }; | |
3508 | ||
3509 | vec_safe_insert (CONSTRUCTOR_ELTS (ctor), idx, ce); | |
3510 | cep = CONSTRUCTOR_ELT (ctor, idx); | |
3511 | } | |
3512 | found:; | |
3513 | ||
3514 | return cep; | |
3515 | } | |
3516 | } | |
3517 | ||
abdc16c8 MS |
3518 | /* Under the control of CTX, issue a detailed diagnostic for |
3519 | an out-of-bounds subscript INDEX into the expression ARRAY. */ | |
3520 | ||
3521 | static void | |
043666e0 | 3522 | diag_array_subscript (location_t loc, const constexpr_ctx *ctx, tree array, tree index) |
abdc16c8 MS |
3523 | { |
3524 | if (!ctx->quiet) | |
3525 | { | |
3526 | tree arraytype = TREE_TYPE (array); | |
3527 | ||
3528 | /* Convert the unsigned array subscript to a signed integer to avoid | |
3529 | printing huge numbers for small negative values. */ | |
3530 | tree sidx = fold_convert (ssizetype, index); | |
043666e0 | 3531 | STRIP_ANY_LOCATION_WRAPPER (array); |
abdc16c8 MS |
3532 | if (DECL_P (array)) |
3533 | { | |
08b3748c | 3534 | if (TYPE_DOMAIN (arraytype)) |
043666e0 JM |
3535 | error_at (loc, "array subscript value %qE is outside the bounds " |
3536 | "of array %qD of type %qT", sidx, array, arraytype); | |
08b3748c | 3537 | else |
043666e0 JM |
3538 | error_at (loc, "nonzero array subscript %qE is used with array %qD of " |
3539 | "type %qT with unknown bounds", sidx, array, arraytype); | |
abdc16c8 MS |
3540 | inform (DECL_SOURCE_LOCATION (array), "declared here"); |
3541 | } | |
08b3748c | 3542 | else if (TYPE_DOMAIN (arraytype)) |
043666e0 JM |
3543 | error_at (loc, "array subscript value %qE is outside the bounds " |
3544 | "of array type %qT", sidx, arraytype); | |
08b3748c | 3545 | else |
043666e0 JM |
3546 | error_at (loc, "nonzero array subscript %qE is used with array of type %qT " |
3547 | "with unknown bounds", sidx, arraytype); | |
abdc16c8 MS |
3548 | } |
3549 | } | |
ceaaf873 | 3550 | |
74f8705e MP |
3551 | /* Return the number of elements for TYPE (which is an ARRAY_TYPE or |
3552 | a VECTOR_TYPE). */ | |
3553 | ||
3554 | static tree | |
3555 | get_array_or_vector_nelts (const constexpr_ctx *ctx, tree type, | |
3556 | bool *non_constant_p, bool *overflow_p) | |
3557 | { | |
3558 | tree nelts; | |
3559 | if (TREE_CODE (type) == ARRAY_TYPE) | |
3560 | { | |
3561 | if (TYPE_DOMAIN (type)) | |
3562 | nelts = array_type_nelts_top (type); | |
3563 | else | |
3564 | nelts = size_zero_node; | |
3565 | } | |
3566 | else if (VECTOR_TYPE_P (type)) | |
3567 | nelts = size_int (TYPE_VECTOR_SUBPARTS (type)); | |
3568 | else | |
3569 | gcc_unreachable (); | |
3570 | ||
3571 | /* For VLAs, the number of elements won't be an integer constant. */ | |
3572 | nelts = cxx_eval_constant_expression (ctx, nelts, false, | |
3573 | non_constant_p, overflow_p); | |
3574 | return nelts; | |
3575 | } | |
3576 | ||
d6b46fca NS |
3577 | /* Extract element INDEX consisting of CHARS_PER_ELT chars from |
3578 | STRING_CST STRING. */ | |
3579 | ||
3580 | static tree | |
3581 | extract_string_elt (tree string, unsigned chars_per_elt, unsigned index) | |
3582 | { | |
3583 | tree type = cv_unqualified (TREE_TYPE (TREE_TYPE (string))); | |
3584 | tree r; | |
3585 | ||
3586 | if (chars_per_elt == 1) | |
3587 | r = build_int_cst (type, TREE_STRING_POINTER (string)[index]); | |
3588 | else | |
3589 | { | |
3590 | const unsigned char *ptr | |
3591 | = ((const unsigned char *)TREE_STRING_POINTER (string) | |
3592 | + index * chars_per_elt); | |
3593 | r = native_interpret_expr (type, ptr, chars_per_elt); | |
3594 | } | |
3595 | return r; | |
3596 | } | |
3597 | ||
043666e0 JM |
3598 | /* Subroutine of cxx_eval_array_reference. T is an ARRAY_REF; evaluate the |
3599 | subscript, diagnose any problems with it, and return the result. */ | |
3600 | ||
3601 | static tree | |
3602 | eval_and_check_array_index (const constexpr_ctx *ctx, | |
3603 | tree t, bool allow_one_past, | |
3604 | bool *non_constant_p, bool *overflow_p) | |
3605 | { | |
f9d0ca40 | 3606 | location_t loc = cp_expr_loc_or_input_loc (t); |
043666e0 JM |
3607 | tree ary = TREE_OPERAND (t, 0); |
3608 | t = TREE_OPERAND (t, 1); | |
3609 | tree index = cxx_eval_constant_expression (ctx, t, false, | |
3610 | non_constant_p, overflow_p); | |
3611 | VERIFY_CONSTANT (index); | |
3612 | ||
3613 | if (!tree_fits_shwi_p (index) | |
3614 | || tree_int_cst_sgn (index) < 0) | |
3615 | { | |
3616 | diag_array_subscript (loc, ctx, ary, index); | |
3617 | *non_constant_p = true; | |
3618 | return t; | |
3619 | } | |
3620 | ||
3621 | tree nelts = get_array_or_vector_nelts (ctx, TREE_TYPE (ary), non_constant_p, | |
3622 | overflow_p); | |
3623 | VERIFY_CONSTANT (nelts); | |
3624 | if (allow_one_past | |
3625 | ? !tree_int_cst_le (index, nelts) | |
3626 | : !tree_int_cst_lt (index, nelts)) | |
3627 | { | |
3628 | diag_array_subscript (loc, ctx, ary, index); | |
3629 | *non_constant_p = true; | |
3630 | return t; | |
3631 | } | |
3632 | ||
3633 | return index; | |
3634 | } | |
3635 | ||
2d76680f PC |
3636 | /* Subroutine of cxx_eval_constant_expression. |
3637 | Attempt to reduce a reference to an array slot. */ | |
3638 | ||
3639 | static tree | |
3e605b20 | 3640 | cxx_eval_array_reference (const constexpr_ctx *ctx, tree t, |
92a596e8 | 3641 | bool lval, |
2d76680f PC |
3642 | bool *non_constant_p, bool *overflow_p) |
3643 | { | |
3644 | tree oldary = TREE_OPERAND (t, 0); | |
3e605b20 | 3645 | tree ary = cxx_eval_constant_expression (ctx, oldary, |
92a596e8 | 3646 | lval, |
5a804683 | 3647 | non_constant_p, overflow_p); |
2d76680f PC |
3648 | if (*non_constant_p) |
3649 | return t; | |
bc2687dd JJ |
3650 | if (!lval |
3651 | && TREE_CODE (ary) == VIEW_CONVERT_EXPR | |
043666e0 JM |
3652 | && VECTOR_TYPE_P (TREE_TYPE (TREE_OPERAND (ary, 0))) |
3653 | && TREE_TYPE (t) == TREE_TYPE (TREE_TYPE (TREE_OPERAND (ary, 0)))) | |
3654 | ary = TREE_OPERAND (ary, 0); | |
3b9997bb | 3655 | |
043666e0 JM |
3656 | tree oldidx = TREE_OPERAND (t, 1); |
3657 | tree index = eval_and_check_array_index (ctx, t, lval, | |
3658 | non_constant_p, overflow_p); | |
3659 | if (*non_constant_p) | |
3660 | return t; | |
5453bfed | 3661 | |
bc2a38df JJ |
3662 | if (lval && ary == oldary && index == oldidx) |
3663 | return t; | |
3664 | else if (lval) | |
3665 | return build4 (ARRAY_REF, TREE_TYPE (t), ary, index, NULL, NULL); | |
3666 | ||
043666e0 JM |
3667 | unsigned len = 0, elem_nchars = 1; |
3668 | tree elem_type = TREE_TYPE (TREE_TYPE (ary)); | |
3669 | if (TREE_CODE (ary) == CONSTRUCTOR) | |
3670 | len = CONSTRUCTOR_NELTS (ary); | |
3671 | else if (TREE_CODE (ary) == STRING_CST) | |
3672 | { | |
3673 | elem_nchars = (TYPE_PRECISION (elem_type) | |
3674 | / TYPE_PRECISION (char_type_node)); | |
3675 | len = (unsigned) TREE_STRING_LENGTH (ary) / elem_nchars; | |
3676 | } | |
3677 | else if (TREE_CODE (ary) == VECTOR_CST) | |
3678 | /* We don't create variable-length VECTOR_CSTs. */ | |
3679 | len = VECTOR_CST_NELTS (ary).to_constant (); | |
3680 | else | |
3681 | { | |
3682 | /* We can't do anything with other tree codes, so use | |
3683 | VERIFY_CONSTANT to complain and fail. */ | |
3684 | VERIFY_CONSTANT (ary); | |
3685 | gcc_unreachable (); | |
3686 | } | |
3687 | ||
ceaaf873 | 3688 | bool found; |
043666e0 | 3689 | HOST_WIDE_INT i = 0; |
ceaaf873 JM |
3690 | if (TREE_CODE (ary) == CONSTRUCTOR) |
3691 | { | |
3692 | HOST_WIDE_INT ix = find_array_ctor_elt (ary, index); | |
3693 | found = (ix >= 0); | |
3694 | if (found) | |
3695 | i = ix; | |
3b9997bb | 3696 | } |
ceaaf873 | 3697 | else |
043666e0 JM |
3698 | { |
3699 | i = tree_to_shwi (index); | |
3700 | found = (i < len); | |
3701 | } | |
3b9997bb | 3702 | |
fd2bfee5 JM |
3703 | if (found) |
3704 | { | |
3705 | tree r; | |
3706 | if (TREE_CODE (ary) == CONSTRUCTOR) | |
3707 | r = (*CONSTRUCTOR_ELTS (ary))[i].value; | |
3708 | else if (TREE_CODE (ary) == VECTOR_CST) | |
3709 | r = VECTOR_CST_ELT (ary, i); | |
fd2bfee5 | 3710 | else |
d6b46fca NS |
3711 | r = extract_string_elt (ary, elem_nchars, i); |
3712 | ||
fd2bfee5 JM |
3713 | if (r) |
3714 | /* Don't VERIFY_CONSTANT here. */ | |
3715 | return r; | |
2d76680f | 3716 | |
fd2bfee5 | 3717 | /* Otherwise the element doesn't have a value yet. */ |
2d76680f | 3718 | } |
3b9997bb | 3719 | |
fd2bfee5 JM |
3720 | /* Not found. */ |
3721 | ||
3722 | if (TREE_CODE (ary) == CONSTRUCTOR | |
e8c48716 | 3723 | && CONSTRUCTOR_NO_CLEARING (ary)) |
2d76680f | 3724 | { |
fd2bfee5 JM |
3725 | /* 'ary' is part of the aggregate initializer we're currently |
3726 | building; if there's no initializer for this element yet, | |
3727 | that's an error. */ | |
3728 | if (!ctx->quiet) | |
3729 | error ("accessing uninitialized array element"); | |
3730 | *non_constant_p = true; | |
3731 | return t; | |
2d76680f | 3732 | } |
fd2bfee5 JM |
3733 | |
3734 | /* If it's within the array bounds but doesn't have an explicit | |
0712ea63 JM |
3735 | initializer, it's initialized from {}. But use build_value_init |
3736 | directly for non-aggregates to avoid creating a garbage CONSTRUCTOR. */ | |
3737 | tree val; | |
0df73bee | 3738 | constexpr_ctx new_ctx; |
0712ea63 JM |
3739 | if (CP_AGGREGATE_TYPE_P (elem_type)) |
3740 | { | |
3741 | tree empty_ctor = build_constructor (init_list_type_node, NULL); | |
3742 | val = digest_init (elem_type, empty_ctor, tf_warning_or_error); | |
0df73bee MP |
3743 | new_ctx = *ctx; |
3744 | new_ctx.ctor = build_constructor (elem_type, NULL); | |
3745 | ctx = &new_ctx; | |
0712ea63 JM |
3746 | } |
3747 | else | |
3748 | val = build_value_init (elem_type, tf_warning_or_error); | |
0df73bee MP |
3749 | t = cxx_eval_constant_expression (ctx, val, lval, non_constant_p, |
3750 | overflow_p); | |
3751 | if (CP_AGGREGATE_TYPE_P (elem_type) && t != ctx->ctor) | |
3752 | free_constructor (ctx->ctor); | |
3753 | return t; | |
2d76680f PC |
3754 | } |
3755 | ||
3756 | /* Subroutine of cxx_eval_constant_expression. | |
3757 | Attempt to reduce a field access of a value of class type. */ | |
3758 | ||
3759 | static tree | |
3e605b20 | 3760 | cxx_eval_component_reference (const constexpr_ctx *ctx, tree t, |
92a596e8 | 3761 | bool lval, |
2d76680f PC |
3762 | bool *non_constant_p, bool *overflow_p) |
3763 | { | |
3764 | unsigned HOST_WIDE_INT i; | |
3765 | tree field; | |
3766 | tree value; | |
3767 | tree part = TREE_OPERAND (t, 1); | |
3768 | tree orig_whole = TREE_OPERAND (t, 0); | |
3e605b20 | 3769 | tree whole = cxx_eval_constant_expression (ctx, orig_whole, |
92a596e8 | 3770 | lval, |
5a804683 | 3771 | non_constant_p, overflow_p); |
a7f8415c | 3772 | if (INDIRECT_REF_P (whole) |
bf533db8 JJ |
3773 | && integer_zerop (TREE_OPERAND (whole, 0))) |
3774 | { | |
3775 | if (!ctx->quiet) | |
3776 | error ("dereferencing a null pointer in %qE", orig_whole); | |
3777 | *non_constant_p = true; | |
3778 | return t; | |
3779 | } | |
8bada5cd | 3780 | |
dcdbc004 JM |
3781 | if (TREE_CODE (whole) == PTRMEM_CST) |
3782 | whole = cplus_expand_constant (whole); | |
2d76680f PC |
3783 | if (whole == orig_whole) |
3784 | return t; | |
92a596e8 | 3785 | if (lval) |
2d76680f PC |
3786 | return fold_build3 (COMPONENT_REF, TREE_TYPE (t), |
3787 | whole, part, NULL_TREE); | |
3788 | /* Don't VERIFY_CONSTANT here; we only want to check that we got a | |
3789 | CONSTRUCTOR. */ | |
3790 | if (!*non_constant_p && TREE_CODE (whole) != CONSTRUCTOR) | |
3791 | { | |
2b3ab879 | 3792 | if (!ctx->quiet) |
2d76680f PC |
3793 | error ("%qE is not a constant expression", orig_whole); |
3794 | *non_constant_p = true; | |
3795 | } | |
3796 | if (DECL_MUTABLE_P (part)) | |
3797 | { | |
2b3ab879 | 3798 | if (!ctx->quiet) |
2d76680f PC |
3799 | error ("mutable %qD is not usable in a constant expression", part); |
3800 | *non_constant_p = true; | |
3801 | } | |
3802 | if (*non_constant_p) | |
3803 | return t; | |
2db613e5 | 3804 | bool pmf = TYPE_PTRMEMFUNC_P (TREE_TYPE (whole)); |
2d76680f PC |
3805 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (whole), i, field, value) |
3806 | { | |
2db613e5 JM |
3807 | /* Use name match for PMF fields, as a variant will have a |
3808 | different FIELD_DECL with a different type. */ | |
3809 | if (pmf ? DECL_NAME (field) == DECL_NAME (part) | |
3810 | : field == part) | |
60813a46 JM |
3811 | { |
3812 | if (value) | |
5b884e94 JJ |
3813 | { |
3814 | STRIP_ANY_LOCATION_WRAPPER (value); | |
3815 | return value; | |
3816 | } | |
60813a46 JM |
3817 | else |
3818 | /* We're in the middle of initializing it. */ | |
3819 | break; | |
3820 | } | |
2d76680f PC |
3821 | } |
3822 | if (TREE_CODE (TREE_TYPE (whole)) == UNION_TYPE | |
3823 | && CONSTRUCTOR_NELTS (whole) > 0) | |
3824 | { | |
3825 | /* DR 1188 says we don't have to deal with this. */ | |
2b3ab879 | 3826 | if (!ctx->quiet) |
b599bf9d PP |
3827 | { |
3828 | constructor_elt *cep = CONSTRUCTOR_ELT (whole, 0); | |
3829 | if (cep->value == NULL_TREE) | |
3830 | error ("accessing uninitialized member %qD", part); | |
3831 | else | |
3832 | error ("accessing %qD member instead of initialized %qD member in " | |
3833 | "constant expression", part, cep->index); | |
3834 | } | |
2d76680f PC |
3835 | *non_constant_p = true; |
3836 | return t; | |
3837 | } | |
3838 | ||
188e53bd JM |
3839 | /* We only create a CONSTRUCTOR for a subobject when we modify it, so empty |
3840 | classes never get represented; throw together a value now. */ | |
dbcd32f8 | 3841 | if (is_really_empty_class (TREE_TYPE (t), /*ignore_vptr*/false)) |
188e53bd JM |
3842 | return build_constructor (TREE_TYPE (t), NULL); |
3843 | ||
2db613e5 JM |
3844 | gcc_assert (DECL_CONTEXT (part) == TYPE_MAIN_VARIANT (TREE_TYPE (whole))); |
3845 | ||
e8c48716 | 3846 | if (CONSTRUCTOR_NO_CLEARING (whole)) |
3e605b20 JM |
3847 | { |
3848 | /* 'whole' is part of the aggregate initializer we're currently | |
3849 | building; if there's no initializer for this member yet, that's an | |
188e53bd | 3850 | error. */ |
2b3ab879 | 3851 | if (!ctx->quiet) |
3e605b20 JM |
3852 | error ("accessing uninitialized member %qD", part); |
3853 | *non_constant_p = true; | |
3854 | return t; | |
3855 | } | |
3856 | ||
2d76680f PC |
3857 | /* If there's no explicit init for this field, it's value-initialized. */ |
3858 | value = build_value_init (TREE_TYPE (t), tf_warning_or_error); | |
3e605b20 | 3859 | return cxx_eval_constant_expression (ctx, value, |
92a596e8 | 3860 | lval, |
5a804683 | 3861 | non_constant_p, overflow_p); |
2d76680f PC |
3862 | } |
3863 | ||
3864 | /* Subroutine of cxx_eval_constant_expression. | |
3865 | Attempt to reduce a field access of a value of class type that is | |
3866 | expressed as a BIT_FIELD_REF. */ | |
3867 | ||
3868 | static tree | |
3e605b20 | 3869 | cxx_eval_bit_field_ref (const constexpr_ctx *ctx, tree t, |
92a596e8 | 3870 | bool lval, |
2d76680f PC |
3871 | bool *non_constant_p, bool *overflow_p) |
3872 | { | |
3873 | tree orig_whole = TREE_OPERAND (t, 0); | |
3874 | tree retval, fldval, utype, mask; | |
3875 | bool fld_seen = false; | |
3876 | HOST_WIDE_INT istart, isize; | |
3e605b20 | 3877 | tree whole = cxx_eval_constant_expression (ctx, orig_whole, |
92a596e8 | 3878 | lval, |
5a804683 | 3879 | non_constant_p, overflow_p); |
2d76680f PC |
3880 | tree start, field, value; |
3881 | unsigned HOST_WIDE_INT i; | |
3882 | ||
3883 | if (whole == orig_whole) | |
3884 | return t; | |
3885 | /* Don't VERIFY_CONSTANT here; we only want to check that we got a | |
3886 | CONSTRUCTOR. */ | |
3887 | if (!*non_constant_p | |
3888 | && TREE_CODE (whole) != VECTOR_CST | |
3889 | && TREE_CODE (whole) != CONSTRUCTOR) | |
3890 | { | |
2b3ab879 | 3891 | if (!ctx->quiet) |
2d76680f PC |
3892 | error ("%qE is not a constant expression", orig_whole); |
3893 | *non_constant_p = true; | |
3894 | } | |
3895 | if (*non_constant_p) | |
3896 | return t; | |
3897 | ||
3898 | if (TREE_CODE (whole) == VECTOR_CST) | |
3899 | return fold_ternary (BIT_FIELD_REF, TREE_TYPE (t), whole, | |
3900 | TREE_OPERAND (t, 1), TREE_OPERAND (t, 2)); | |
3901 | ||
3902 | start = TREE_OPERAND (t, 2); | |
3903 | istart = tree_to_shwi (start); | |
3904 | isize = tree_to_shwi (TREE_OPERAND (t, 1)); | |
3905 | utype = TREE_TYPE (t); | |
3906 | if (!TYPE_UNSIGNED (utype)) | |
3907 | utype = build_nonstandard_integer_type (TYPE_PRECISION (utype), 1); | |
3908 | retval = build_int_cst (utype, 0); | |
3909 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (whole), i, field, value) | |
3910 | { | |
3911 | tree bitpos = bit_position (field); | |
5b884e94 | 3912 | STRIP_ANY_LOCATION_WRAPPER (value); |
2d76680f PC |
3913 | if (bitpos == start && DECL_SIZE (field) == TREE_OPERAND (t, 1)) |
3914 | return value; | |
3915 | if (TREE_CODE (TREE_TYPE (field)) == INTEGER_TYPE | |
3916 | && TREE_CODE (value) == INTEGER_CST | |
3917 | && tree_fits_shwi_p (bitpos) | |
3918 | && tree_fits_shwi_p (DECL_SIZE (field))) | |
3919 | { | |
3920 | HOST_WIDE_INT bit = tree_to_shwi (bitpos); | |
3921 | HOST_WIDE_INT sz = tree_to_shwi (DECL_SIZE (field)); | |
3922 | HOST_WIDE_INT shift; | |
3923 | if (bit >= istart && bit + sz <= istart + isize) | |
3924 | { | |
3925 | fldval = fold_convert (utype, value); | |
3926 | mask = build_int_cst_type (utype, -1); | |
3927 | mask = fold_build2 (LSHIFT_EXPR, utype, mask, | |
3928 | size_int (TYPE_PRECISION (utype) - sz)); | |
3929 | mask = fold_build2 (RSHIFT_EXPR, utype, mask, | |
3930 | size_int (TYPE_PRECISION (utype) - sz)); | |
3931 | fldval = fold_build2 (BIT_AND_EXPR, utype, fldval, mask); | |
3932 | shift = bit - istart; | |
3933 | if (BYTES_BIG_ENDIAN) | |
3934 | shift = TYPE_PRECISION (utype) - shift - sz; | |
3935 | fldval = fold_build2 (LSHIFT_EXPR, utype, fldval, | |
3936 | size_int (shift)); | |
3937 | retval = fold_build2 (BIT_IOR_EXPR, utype, retval, fldval); | |
3938 | fld_seen = true; | |
3939 | } | |
3940 | } | |
3941 | } | |
3942 | if (fld_seen) | |
3943 | return fold_convert (TREE_TYPE (t), retval); | |
3944 | gcc_unreachable (); | |
3945 | return error_mark_node; | |
3946 | } | |
3947 | ||
3948 | /* Subroutine of cxx_eval_constant_expression. | |
3949 | Evaluate a short-circuited logical expression T in the context | |
3950 | of a given constexpr CALL. BAILOUT_VALUE is the value for | |
3951 | early return. CONTINUE_VALUE is used here purely for | |
3952 | sanity check purposes. */ | |
3953 | ||
3954 | static tree | |
3e605b20 | 3955 | cxx_eval_logical_expression (const constexpr_ctx *ctx, tree t, |
2d76680f | 3956 | tree bailout_value, tree continue_value, |
92a596e8 | 3957 | bool lval, |
2d76680f PC |
3958 | bool *non_constant_p, bool *overflow_p) |
3959 | { | |
3960 | tree r; | |
3e605b20 | 3961 | tree lhs = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), |
92a596e8 | 3962 | lval, |
5a804683 | 3963 | non_constant_p, overflow_p); |
2d76680f PC |
3964 | VERIFY_CONSTANT (lhs); |
3965 | if (tree_int_cst_equal (lhs, bailout_value)) | |
3966 | return lhs; | |
3967 | gcc_assert (tree_int_cst_equal (lhs, continue_value)); | |
3e605b20 | 3968 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), |
92a596e8 | 3969 | lval, non_constant_p, |
5a804683 | 3970 | overflow_p); |
2d76680f PC |
3971 | VERIFY_CONSTANT (r); |
3972 | return r; | |
3973 | } | |
3974 | ||
3975 | /* REF is a COMPONENT_REF designating a particular field. V is a vector of | |
3976 | CONSTRUCTOR elements to initialize (part of) an object containing that | |
3977 | field. Return a pointer to the constructor_elt corresponding to the | |
3978 | initialization of the field. */ | |
3979 | ||
3980 | static constructor_elt * | |
3981 | base_field_constructor_elt (vec<constructor_elt, va_gc> *v, tree ref) | |
3982 | { | |
3983 | tree aggr = TREE_OPERAND (ref, 0); | |
3984 | tree field = TREE_OPERAND (ref, 1); | |
3985 | HOST_WIDE_INT i; | |
3986 | constructor_elt *ce; | |
3987 | ||
3988 | gcc_assert (TREE_CODE (ref) == COMPONENT_REF); | |
3989 | ||
3990 | if (TREE_CODE (aggr) == COMPONENT_REF) | |
3991 | { | |
3992 | constructor_elt *base_ce | |
3993 | = base_field_constructor_elt (v, aggr); | |
3994 | v = CONSTRUCTOR_ELTS (base_ce->value); | |
3995 | } | |
3996 | ||
3997 | for (i = 0; vec_safe_iterate (v, i, &ce); ++i) | |
3998 | if (ce->index == field) | |
3999 | return ce; | |
4000 | ||
4001 | gcc_unreachable (); | |
4002 | return NULL; | |
4003 | } | |
4004 | ||
3e605b20 JM |
4005 | /* Some of the expressions fed to the constexpr mechanism are calls to |
4006 | constructors, which have type void. In that case, return the type being | |
4007 | initialized by the constructor. */ | |
4008 | ||
4009 | static tree | |
4010 | initialized_type (tree t) | |
4011 | { | |
4012 | if (TYPE_P (t)) | |
4013 | return t; | |
5dab8b11 | 4014 | tree type = TREE_TYPE (t); |
4d0c18c6 | 4015 | if (TREE_CODE (t) == CALL_EXPR) |
3e605b20 JM |
4016 | { |
4017 | /* A constructor call has void type, so we need to look deeper. */ | |
4018 | tree fn = get_function_named_in_call (t); | |
4019 | if (fn && TREE_CODE (fn) == FUNCTION_DECL | |
4020 | && DECL_CXX_CONSTRUCTOR_P (fn)) | |
4021 | type = DECL_CONTEXT (fn); | |
4022 | } | |
4d0c18c6 JM |
4023 | else if (TREE_CODE (t) == COMPOUND_EXPR) |
4024 | return initialized_type (TREE_OPERAND (t, 1)); | |
5dab8b11 JM |
4025 | else if (TREE_CODE (t) == AGGR_INIT_EXPR) |
4026 | type = TREE_TYPE (AGGR_INIT_EXPR_SLOT (t)); | |
4027 | return cv_unqualified (type); | |
3e605b20 JM |
4028 | } |
4029 | ||
4030 | /* We're about to initialize element INDEX of an array or class from VALUE. | |
4031 | Set up NEW_CTX appropriately by adjusting .object to refer to the | |
4032 | subobject and creating a new CONSTRUCTOR if the element is itself | |
4033 | a class or array. */ | |
4034 | ||
4035 | static void | |
4036 | init_subob_ctx (const constexpr_ctx *ctx, constexpr_ctx &new_ctx, | |
4037 | tree index, tree &value) | |
4038 | { | |
4039 | new_ctx = *ctx; | |
4040 | ||
4041 | if (index && TREE_CODE (index) != INTEGER_CST | |
3d423c6f PP |
4042 | && TREE_CODE (index) != FIELD_DECL |
4043 | && TREE_CODE (index) != RANGE_EXPR) | |
3e605b20 JM |
4044 | /* This won't have an element in the new CONSTRUCTOR. */ |
4045 | return; | |
4046 | ||
4047 | tree type = initialized_type (value); | |
4048 | if (!AGGREGATE_TYPE_P (type) && !VECTOR_TYPE_P (type)) | |
4049 | /* A non-aggregate member doesn't get its own CONSTRUCTOR. */ | |
4050 | return; | |
4051 | ||
4052 | /* The sub-aggregate initializer might contain a placeholder; | |
4053 | update object to refer to the subobject and ctor to refer to | |
4054 | the (newly created) sub-initializer. */ | |
4055 | if (ctx->object) | |
3d423c6f PP |
4056 | { |
4057 | if (index == NULL_TREE || TREE_CODE (index) == RANGE_EXPR) | |
4058 | /* There's no well-defined subobject for this index. */ | |
4059 | new_ctx.object = NULL_TREE; | |
4060 | else | |
4061 | new_ctx.object = build_ctor_subob_ref (index, type, ctx->object); | |
4062 | } | |
3e605b20 | 4063 | tree elt = build_constructor (type, NULL); |
e8c48716 | 4064 | CONSTRUCTOR_NO_CLEARING (elt) = true; |
3e605b20 JM |
4065 | new_ctx.ctor = elt; |
4066 | ||
4067 | if (TREE_CODE (value) == TARGET_EXPR) | |
4068 | /* Avoid creating another CONSTRUCTOR when we expand the TARGET_EXPR. */ | |
4069 | value = TARGET_EXPR_INITIAL (value); | |
4070 | } | |
4071 | ||
4072 | /* We're about to process an initializer for a class or array TYPE. Make | |
4073 | sure that CTX is set up appropriately. */ | |
4074 | ||
4075 | static void | |
4076 | verify_ctor_sanity (const constexpr_ctx *ctx, tree type) | |
4077 | { | |
4078 | /* We don't bother building a ctor for an empty base subobject. */ | |
4079 | if (is_empty_class (type)) | |
4080 | return; | |
4081 | ||
4082 | /* We're in the middle of an initializer that might involve placeholders; | |
4083 | our caller should have created a CONSTRUCTOR for us to put the | |
4084 | initializer into. We will either return that constructor or T. */ | |
4085 | gcc_assert (ctx->ctor); | |
4086 | gcc_assert (same_type_ignoring_top_level_qualifiers_p | |
4087 | (type, TREE_TYPE (ctx->ctor))); | |
fe69277d JM |
4088 | /* We used to check that ctx->ctor was empty, but that isn't the case when |
4089 | the object is zero-initialized before calling the constructor. */ | |
3e605b20 | 4090 | if (ctx->object) |
176e79b5 JM |
4091 | { |
4092 | tree otype = TREE_TYPE (ctx->object); | |
4093 | gcc_assert (same_type_ignoring_top_level_qualifiers_p (type, otype) | |
4094 | /* Handle flexible array members. */ | |
4095 | || (TREE_CODE (otype) == ARRAY_TYPE | |
4096 | && TYPE_DOMAIN (otype) == NULL_TREE | |
4097 | && TREE_CODE (type) == ARRAY_TYPE | |
4098 | && (same_type_ignoring_top_level_qualifiers_p | |
4099 | (TREE_TYPE (type), TREE_TYPE (otype))))); | |
4100 | } | |
3e605b20 | 4101 | gcc_assert (!ctx->object || !DECL_P (ctx->object) |
8e007055 | 4102 | || *(ctx->global->values.get (ctx->object)) == ctx->ctor); |
3e605b20 JM |
4103 | } |
4104 | ||
2d76680f PC |
4105 | /* Subroutine of cxx_eval_constant_expression. |
4106 | The expression tree T denotes a C-style array or a C-style | |
4107 | aggregate. Reduce it to a constant expression. */ | |
4108 | ||
4109 | static tree | |
3e605b20 | 4110 | cxx_eval_bare_aggregate (const constexpr_ctx *ctx, tree t, |
92a596e8 | 4111 | bool lval, |
2d76680f PC |
4112 | bool *non_constant_p, bool *overflow_p) |
4113 | { | |
4114 | vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (t); | |
2d76680f PC |
4115 | bool changed = false; |
4116 | gcc_assert (!BRACE_ENCLOSED_INITIALIZER_P (t)); | |
8a29084d | 4117 | tree type = TREE_TYPE (t); |
3e605b20 | 4118 | |
8a29084d | 4119 | constexpr_ctx new_ctx; |
d4619dc1 | 4120 | if (TYPE_PTRMEMFUNC_P (type) || VECTOR_TYPE_P (type)) |
8a29084d | 4121 | { |
d4619dc1 NS |
4122 | /* We don't really need the ctx->ctor business for a PMF or |
4123 | vector, but it's simpler to use the same code. */ | |
8a29084d JM |
4124 | new_ctx = *ctx; |
4125 | new_ctx.ctor = build_constructor (type, NULL); | |
4126 | new_ctx.object = NULL_TREE; | |
4127 | ctx = &new_ctx; | |
4128 | }; | |
4129 | verify_ctor_sanity (ctx, type); | |
3e605b20 JM |
4130 | vec<constructor_elt, va_gc> **p = &CONSTRUCTOR_ELTS (ctx->ctor); |
4131 | vec_alloc (*p, vec_safe_length (v)); | |
4132 | ||
49a86fce PP |
4133 | if (CONSTRUCTOR_PLACEHOLDER_BOUNDARY (t)) |
4134 | CONSTRUCTOR_PLACEHOLDER_BOUNDARY (ctx->ctor) = 1; | |
4135 | ||
2d63bc39 JM |
4136 | unsigned i; |
4137 | tree index, value; | |
4138 | bool constant_p = true; | |
4139 | bool side_effects_p = false; | |
3e605b20 | 4140 | FOR_EACH_CONSTRUCTOR_ELT (v, i, index, value) |
2d76680f | 4141 | { |
bcb5f3c9 | 4142 | tree orig_value = value; |
3e605b20 | 4143 | init_subob_ctx (ctx, new_ctx, index, value); |
37244b21 | 4144 | int pos_hint = -1; |
3e605b20 | 4145 | if (new_ctx.ctor != ctx->ctor) |
37244b21 PP |
4146 | { |
4147 | /* If we built a new CONSTRUCTOR, attach it now so that other | |
4148 | initializers can refer to it. */ | |
077dd9b3 PP |
4149 | constructor_elt *cep = get_or_insert_ctor_field (ctx->ctor, index); |
4150 | cep->value = new_ctx.ctor; | |
4151 | pos_hint = cep - (*p)->begin(); | |
37244b21 | 4152 | } |
b599bf9d | 4153 | else if (TREE_CODE (type) == UNION_TYPE) |
37244b21 PP |
4154 | /* Otherwise if we're constructing a non-aggregate union member, set |
4155 | the active union member now so that we can later detect and diagnose | |
4156 | if its initializer attempts to activate another member. */ | |
077dd9b3 | 4157 | get_or_insert_ctor_field (ctx->ctor, index); |
3e605b20 | 4158 | tree elt = cxx_eval_constant_expression (&new_ctx, value, |
92a596e8 | 4159 | lval, |
5a804683 | 4160 | non_constant_p, overflow_p); |
2d76680f | 4161 | /* Don't VERIFY_CONSTANT here. */ |
2b3ab879 | 4162 | if (ctx->quiet && *non_constant_p) |
3e605b20 | 4163 | break; |
bcb5f3c9 | 4164 | if (elt != orig_value) |
2d76680f | 4165 | changed = true; |
2d63bc39 JM |
4166 | |
4167 | if (!TREE_CONSTANT (elt)) | |
4168 | constant_p = false; | |
4169 | if (TREE_SIDE_EFFECTS (elt)) | |
4170 | side_effects_p = true; | |
3e605b20 | 4171 | if (index && TREE_CODE (index) == COMPONENT_REF) |
2d76680f PC |
4172 | { |
4173 | /* This is an initialization of a vfield inside a base | |
4174 | subaggregate that we already initialized; push this | |
4175 | initialization into the previous initialization. */ | |
3e605b20 | 4176 | constructor_elt *inner = base_field_constructor_elt (*p, index); |
2d76680f | 4177 | inner->value = elt; |
3e605b20 | 4178 | changed = true; |
2d76680f | 4179 | } |
3e605b20 JM |
4180 | else if (index |
4181 | && (TREE_CODE (index) == NOP_EXPR | |
4182 | || TREE_CODE (index) == POINTER_PLUS_EXPR)) | |
2d76680f PC |
4183 | { |
4184 | /* This is an initializer for an empty base; now that we've | |
4185 | checked that it's constant, we can ignore it. */ | |
3e605b20 JM |
4186 | gcc_assert (is_empty_class (TREE_TYPE (TREE_TYPE (index)))); |
4187 | changed = true; | |
4188 | } | |
2d76680f | 4189 | else |
ac9ec198 | 4190 | { |
b599bf9d PP |
4191 | if (TREE_CODE (type) == UNION_TYPE |
4192 | && (*p)->last().index != index) | |
37244b21 PP |
4193 | /* The initializer erroneously changed the active union member that |
4194 | we're initializing. */ | |
b599bf9d | 4195 | gcc_assert (*non_constant_p); |
37244b21 | 4196 | else |
1bdbef09 | 4197 | { |
37244b21 PP |
4198 | /* The initializer might have mutated the underlying CONSTRUCTOR, |
4199 | so recompute the location of the target constructer_elt. */ | |
4200 | constructor_elt *cep | |
4201 | = get_or_insert_ctor_field (ctx->ctor, index, pos_hint); | |
4202 | cep->value = elt; | |
1bdbef09 | 4203 | } |
37244b21 | 4204 | |
1bdbef09 | 4205 | /* Adding or replacing an element might change the ctor's flags. */ |
ac9ec198 MP |
4206 | TREE_CONSTANT (ctx->ctor) = constant_p; |
4207 | TREE_SIDE_EFFECTS (ctx->ctor) = side_effects_p; | |
4208 | } | |
2d76680f PC |
4209 | } |
4210 | if (*non_constant_p || !changed) | |
3e605b20 JM |
4211 | return t; |
4212 | t = ctx->ctor; | |
4213 | /* We're done building this CONSTRUCTOR, so now we can interpret an | |
4214 | element without an explicit initializer as value-initialized. */ | |
e8c48716 | 4215 | CONSTRUCTOR_NO_CLEARING (t) = false; |
2d63bc39 JM |
4216 | TREE_CONSTANT (t) = constant_p; |
4217 | TREE_SIDE_EFFECTS (t) = side_effects_p; | |
8a29084d | 4218 | if (VECTOR_TYPE_P (type)) |
2d76680f PC |
4219 | t = fold (t); |
4220 | return t; | |
4221 | } | |
4222 | ||
4223 | /* Subroutine of cxx_eval_constant_expression. | |
4224 | The expression tree T is a VEC_INIT_EXPR which denotes the desired | |
4225 | initialization of a non-static data member of array type. Reduce it to a | |
4226 | CONSTRUCTOR. | |
4227 | ||
4228 | Note that apart from value-initialization (when VALUE_INIT is true), | |
4229 | this is only intended to support value-initialization and the | |
4230 | initializations done by defaulted constructors for classes with | |
4231 | non-static data members of array type. In this case, VEC_INIT_EXPR_INIT | |
4232 | will either be NULL_TREE for the default constructor, or a COMPONENT_REF | |
4233 | for the copy/move constructor. */ | |
4234 | ||
4235 | static tree | |
3e605b20 | 4236 | cxx_eval_vec_init_1 (const constexpr_ctx *ctx, tree atype, tree init, |
92a596e8 | 4237 | bool value_init, bool lval, |
2d76680f PC |
4238 | bool *non_constant_p, bool *overflow_p) |
4239 | { | |
4240 | tree elttype = TREE_TYPE (atype); | |
3e605b20 JM |
4241 | verify_ctor_sanity (ctx, atype); |
4242 | vec<constructor_elt, va_gc> **p = &CONSTRUCTOR_ELTS (ctx->ctor); | |
2d76680f | 4243 | bool pre_init = false; |
4784470a | 4244 | unsigned HOST_WIDE_INT i; |
dc5ca6c8 | 4245 | tsubst_flags_t complain = ctx->quiet ? tf_none : tf_warning_or_error; |
2d76680f | 4246 | |
a1c9c9ff JM |
4247 | if (init && TREE_CODE (init) == CONSTRUCTOR) |
4248 | return cxx_eval_bare_aggregate (ctx, init, lval, | |
4249 | non_constant_p, overflow_p); | |
4250 | ||
2d76680f PC |
4251 | /* For the default constructor, build up a call to the default |
4252 | constructor of the element type. We only need to handle class types | |
4253 | here, as for a constructor to be constexpr, all members must be | |
4254 | initialized, which for a defaulted default constructor means they must | |
4255 | be of a class type with a constexpr default constructor. */ | |
4256 | if (TREE_CODE (elttype) == ARRAY_TYPE) | |
4257 | /* We only do this at the lowest level. */; | |
4258 | else if (value_init) | |
4259 | { | |
dc5ca6c8 | 4260 | init = build_value_init (elttype, complain); |
2d76680f PC |
4261 | pre_init = true; |
4262 | } | |
4263 | else if (!init) | |
4264 | { | |
cd9cf97b | 4265 | releasing_vec argvec; |
2d76680f PC |
4266 | init = build_special_member_call (NULL_TREE, complete_ctor_identifier, |
4267 | &argvec, elttype, LOOKUP_NORMAL, | |
dc5ca6c8 | 4268 | complain); |
5dab8b11 | 4269 | init = build_aggr_init_expr (elttype, init); |
2d76680f PC |
4270 | pre_init = true; |
4271 | } | |
4272 | ||
d21252de PP |
4273 | bool zeroed_out = false; |
4274 | if (!CONSTRUCTOR_NO_CLEARING (ctx->ctor)) | |
4275 | { | |
4276 | /* We're initializing an array object that had been zero-initialized | |
4277 | earlier. Truncate ctx->ctor, and propagate its zeroed state by | |
4278 | clearing CONSTRUCTOR_NO_CLEARING on each of the aggregate element | |
4279 | initializers we append to it. */ | |
4280 | gcc_checking_assert (initializer_zerop (ctx->ctor)); | |
4281 | zeroed_out = true; | |
4282 | vec_safe_truncate (*p, 0); | |
4283 | } | |
4284 | ||
74f8705e MP |
4285 | tree nelts = get_array_or_vector_nelts (ctx, atype, non_constant_p, |
4286 | overflow_p); | |
4287 | unsigned HOST_WIDE_INT max = tree_to_uhwi (nelts); | |
4784470a | 4288 | for (i = 0; i < max; ++i) |
2d76680f PC |
4289 | { |
4290 | tree idx = build_int_cst (size_type_node, i); | |
4291 | tree eltinit; | |
928af3bf | 4292 | bool reuse = false; |
3e605b20 JM |
4293 | constexpr_ctx new_ctx; |
4294 | init_subob_ctx (ctx, new_ctx, idx, pre_init ? init : elttype); | |
4295 | if (new_ctx.ctor != ctx->ctor) | |
d21252de PP |
4296 | { |
4297 | if (zeroed_out) | |
4298 | CONSTRUCTOR_NO_CLEARING (new_ctx.ctor) = false; | |
4299 | CONSTRUCTOR_APPEND_ELT (*p, idx, new_ctx.ctor); | |
4300 | } | |
2d76680f PC |
4301 | if (TREE_CODE (elttype) == ARRAY_TYPE) |
4302 | { | |
4303 | /* A multidimensional array; recurse. */ | |
4304 | if (value_init || init == NULL_TREE) | |
928af3bf JJ |
4305 | { |
4306 | eltinit = NULL_TREE; | |
4307 | reuse = i == 0; | |
4308 | } | |
2d76680f | 4309 | else |
dc5ca6c8 | 4310 | eltinit = cp_build_array_ref (input_location, init, idx, complain); |
3e605b20 | 4311 | eltinit = cxx_eval_vec_init_1 (&new_ctx, elttype, eltinit, value_init, |
92a596e8 | 4312 | lval, |
2d76680f PC |
4313 | non_constant_p, overflow_p); |
4314 | } | |
4315 | else if (pre_init) | |
4316 | { | |
4317 | /* Initializing an element using value or default initialization | |
4318 | we just pre-built above. */ | |
3ee378fb JM |
4319 | if (init == void_node) |
4320 | /* Trivial default-init, don't do anything to the CONSTRUCTOR. */ | |
4321 | return ctx->ctor; | |
928af3bf JJ |
4322 | eltinit = cxx_eval_constant_expression (&new_ctx, init, lval, |
4323 | non_constant_p, overflow_p); | |
4324 | reuse = i == 0; | |
2d76680f PC |
4325 | } |
4326 | else | |
4327 | { | |
4328 | /* Copying an element. */ | |
4329 | gcc_assert (same_type_ignoring_top_level_qualifiers_p | |
4330 | (atype, TREE_TYPE (init))); | |
dc5ca6c8 | 4331 | eltinit = cp_build_array_ref (input_location, init, idx, complain); |
72b3e203 | 4332 | if (!lvalue_p (init)) |
2d76680f | 4333 | eltinit = move (eltinit); |
dc5ca6c8 | 4334 | eltinit = force_rvalue (eltinit, complain); |
c2236b9b JJ |
4335 | eltinit = cxx_eval_constant_expression (&new_ctx, eltinit, lval, |
4336 | non_constant_p, overflow_p); | |
2d76680f | 4337 | } |
2b3ab879 | 4338 | if (*non_constant_p && !ctx->quiet) |
3e605b20 JM |
4339 | break; |
4340 | if (new_ctx.ctor != ctx->ctor) | |
4341 | { | |
4342 | /* We appended this element above; update the value. */ | |
4343 | gcc_assert ((*p)->last().index == idx); | |
4344 | (*p)->last().value = eltinit; | |
4345 | } | |
4346 | else | |
4347 | CONSTRUCTOR_APPEND_ELT (*p, idx, eltinit); | |
928af3bf | 4348 | /* Reuse the result of cxx_eval_constant_expression call |
c2236b9b JJ |
4349 | from the first iteration to all others if it is a constant |
4350 | initializer that doesn't require relocations. */ | |
928af3bf JJ |
4351 | if (reuse |
4352 | && max > 1 | |
c2236b9b JJ |
4353 | && (eltinit == NULL_TREE |
4354 | || (initializer_constant_valid_p (eltinit, TREE_TYPE (eltinit)) | |
4355 | == null_pointer_node))) | |
928af3bf JJ |
4356 | { |
4357 | if (new_ctx.ctor != ctx->ctor) | |
4358 | eltinit = new_ctx.ctor; | |
1e027956 RB |
4359 | tree range = build2 (RANGE_EXPR, size_type_node, |
4360 | build_int_cst (size_type_node, 1), | |
4361 | build_int_cst (size_type_node, max - 1)); | |
4362 | CONSTRUCTOR_APPEND_ELT (*p, range, unshare_constructor (eltinit)); | |
928af3bf JJ |
4363 | break; |
4364 | } | |
1e027956 RB |
4365 | else if (i == 0) |
4366 | vec_safe_reserve (*p, max); | |
2d76680f PC |
4367 | } |
4368 | ||
4369 | if (!*non_constant_p) | |
4370 | { | |
3e605b20 | 4371 | init = ctx->ctor; |
e8c48716 | 4372 | CONSTRUCTOR_NO_CLEARING (init) = false; |
2d76680f | 4373 | } |
2d76680f PC |
4374 | return init; |
4375 | } | |
4376 | ||
4377 | static tree | |
3e605b20 | 4378 | cxx_eval_vec_init (const constexpr_ctx *ctx, tree t, |
92a596e8 | 4379 | bool lval, |
2d76680f PC |
4380 | bool *non_constant_p, bool *overflow_p) |
4381 | { | |
4382 | tree atype = TREE_TYPE (t); | |
4383 | tree init = VEC_INIT_EXPR_INIT (t); | |
3e605b20 | 4384 | tree r = cxx_eval_vec_init_1 (ctx, atype, init, |
2d76680f | 4385 | VEC_INIT_EXPR_VALUE_INIT (t), |
92a596e8 | 4386 | lval, non_constant_p, overflow_p); |
2d76680f PC |
4387 | if (*non_constant_p) |
4388 | return t; | |
4389 | else | |
4390 | return r; | |
4391 | } | |
4392 | ||
e4511ca2 JM |
4393 | /* Like same_type_ignoring_top_level_qualifiers_p, but also handle the case |
4394 | where the desired type is an array of unknown bounds because the variable | |
4395 | has had its bounds deduced since the wrapping expression was created. */ | |
4396 | ||
4397 | static bool | |
4398 | same_type_ignoring_tlq_and_bounds_p (tree type1, tree type2) | |
4399 | { | |
4400 | while (TREE_CODE (type1) == ARRAY_TYPE | |
4401 | && TREE_CODE (type2) == ARRAY_TYPE | |
4402 | && (!TYPE_DOMAIN (type1) || !TYPE_DOMAIN (type2))) | |
4403 | { | |
4404 | type1 = TREE_TYPE (type1); | |
4405 | type2 = TREE_TYPE (type2); | |
4406 | } | |
4407 | return same_type_ignoring_top_level_qualifiers_p (type1, type2); | |
4408 | } | |
4409 | ||
0fe2ae29 JJ |
4410 | /* Helper function for cxx_fold_indirect_ref_1, called recursively. */ |
4411 | ||
4412 | static tree | |
4413 | cxx_fold_indirect_ref_1 (location_t loc, tree type, tree op, | |
4414 | unsigned HOST_WIDE_INT off, bool *empty_base) | |
4415 | { | |
4416 | tree optype = TREE_TYPE (op); | |
4417 | unsigned HOST_WIDE_INT const_nunits; | |
4418 | if (off == 0) | |
4419 | { | |
4420 | if (similar_type_p (optype, type)) | |
4421 | return op; | |
4422 | /* Also handle conversion to an empty base class, which | |
4423 | is represented with a NOP_EXPR. */ | |
4424 | /* *(foo *)&complexfoo => __real__ complexfoo */ | |
4425 | else if (TREE_CODE (optype) == COMPLEX_TYPE | |
4426 | && similar_type_p (type, TREE_TYPE (optype))) | |
4427 | return build1_loc (loc, REALPART_EXPR, type, op); | |
4428 | } | |
4429 | /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */ | |
4430 | else if (TREE_CODE (optype) == COMPLEX_TYPE | |
4431 | && similar_type_p (type, TREE_TYPE (optype)) | |
4432 | && tree_to_uhwi (TYPE_SIZE_UNIT (type)) == off) | |
4433 | return build1_loc (loc, IMAGPART_EXPR, type, op); | |
4434 | if (is_empty_class (type) | |
4435 | && CLASS_TYPE_P (optype) | |
4436 | && DERIVED_FROM_P (type, optype)) | |
4437 | { | |
4438 | *empty_base = true; | |
4439 | return op; | |
4440 | } | |
4441 | /* ((foo*)&vectorfoo)[x] => BIT_FIELD_REF<vectorfoo,...> */ | |
4442 | else if (VECTOR_TYPE_P (optype) | |
4443 | && similar_type_p (type, TREE_TYPE (optype)) | |
4444 | && TYPE_VECTOR_SUBPARTS (optype).is_constant (&const_nunits)) | |
4445 | { | |
4446 | unsigned HOST_WIDE_INT part_width = tree_to_uhwi (TYPE_SIZE_UNIT (type)); | |
4447 | unsigned HOST_WIDE_INT max_offset = part_width * const_nunits; | |
4448 | if (off < max_offset && off % part_width == 0) | |
4449 | { | |
4450 | tree index = bitsize_int (off * BITS_PER_UNIT); | |
4451 | return build3_loc (loc, BIT_FIELD_REF, type, op, | |
4452 | TYPE_SIZE (type), index); | |
4453 | } | |
4454 | } | |
4455 | /* ((foo *)&fooarray)[x] => fooarray[x] */ | |
4456 | else if (TREE_CODE (optype) == ARRAY_TYPE | |
4457 | && tree_fits_uhwi_p (TYPE_SIZE_UNIT (TREE_TYPE (optype))) | |
4458 | && !integer_zerop (TYPE_SIZE_UNIT (TREE_TYPE (optype)))) | |
4459 | { | |
4460 | tree type_domain = TYPE_DOMAIN (optype); | |
4461 | tree min_val = size_zero_node; | |
4462 | if (type_domain && TYPE_MIN_VALUE (type_domain)) | |
4463 | min_val = TYPE_MIN_VALUE (type_domain); | |
4464 | unsigned HOST_WIDE_INT el_sz | |
4465 | = tree_to_uhwi (TYPE_SIZE_UNIT (TREE_TYPE (optype))); | |
4466 | unsigned HOST_WIDE_INT idx = off / el_sz; | |
4467 | unsigned HOST_WIDE_INT rem = off % el_sz; | |
4468 | if (tree_fits_uhwi_p (min_val)) | |
4469 | { | |
4470 | tree index = size_int (idx + tree_to_uhwi (min_val)); | |
4471 | op = build4_loc (loc, ARRAY_REF, TREE_TYPE (optype), op, index, | |
4472 | NULL_TREE, NULL_TREE); | |
4473 | return cxx_fold_indirect_ref_1 (loc, type, op, rem, | |
4474 | empty_base); | |
4475 | } | |
4476 | } | |
4477 | /* ((foo *)&struct_with_foo_field)[x] => COMPONENT_REF */ | |
4478 | else if (TREE_CODE (optype) == RECORD_TYPE) | |
4479 | { | |
4480 | for (tree field = TYPE_FIELDS (optype); | |
4481 | field; field = DECL_CHAIN (field)) | |
4482 | if (TREE_CODE (field) == FIELD_DECL | |
4483 | && TREE_TYPE (field) != error_mark_node | |
4484 | && tree_fits_uhwi_p (TYPE_SIZE_UNIT (TREE_TYPE (field)))) | |
4485 | { | |
4486 | tree pos = byte_position (field); | |
4487 | if (!tree_fits_uhwi_p (pos)) | |
4488 | continue; | |
4489 | unsigned HOST_WIDE_INT upos = tree_to_uhwi (pos); | |
4490 | unsigned el_sz | |
4491 | = tree_to_uhwi (TYPE_SIZE_UNIT (TREE_TYPE (field))); | |
4492 | if (upos <= off && off < upos + el_sz) | |
4493 | { | |
4494 | tree cop = build3 (COMPONENT_REF, TREE_TYPE (field), | |
4495 | op, field, NULL_TREE); | |
4496 | if (tree ret = cxx_fold_indirect_ref_1 (loc, type, cop, | |
4497 | off - upos, | |
4498 | empty_base)) | |
4499 | return ret; | |
4500 | } | |
4501 | } | |
4502 | } | |
4503 | ||
4504 | return NULL_TREE; | |
4505 | } | |
4506 | ||
2d76680f PC |
4507 | /* A less strict version of fold_indirect_ref_1, which requires cv-quals to |
4508 | match. We want to be less strict for simple *& folding; if we have a | |
4509 | non-const temporary that we access through a const pointer, that should | |
4510 | work. We handle this here rather than change fold_indirect_ref_1 | |
4511 | because we're dealing with things like ADDR_EXPR of INTEGER_CST which | |
4512 | don't really make sense outside of constant expression evaluation. Also | |
4513 | we want to allow folding to COMPONENT_REF, which could cause trouble | |
0fe2ae29 | 4514 | with TBAA in fold_indirect_ref_1. */ |
2d76680f PC |
4515 | |
4516 | static tree | |
4517 | cxx_fold_indirect_ref (location_t loc, tree type, tree op0, bool *empty_base) | |
4518 | { | |
ebe4bf41 MP |
4519 | tree sub = op0; |
4520 | tree subtype; | |
4521 | poly_uint64 const_op01; | |
2d76680f | 4522 | |
80de0002 JM |
4523 | /* STRIP_NOPS, but stop if REINTERPRET_CAST_P. */ |
4524 | while (CONVERT_EXPR_P (sub) || TREE_CODE (sub) == NON_LVALUE_EXPR | |
4525 | || TREE_CODE (sub) == VIEW_CONVERT_EXPR) | |
4526 | { | |
4527 | if (TREE_CODE (sub) == NOP_EXPR | |
4528 | && REINTERPRET_CAST_P (sub)) | |
4529 | return NULL_TREE; | |
4530 | sub = TREE_OPERAND (sub, 0); | |
4531 | } | |
4532 | ||
2d76680f | 4533 | subtype = TREE_TYPE (sub); |
71a93b08 | 4534 | if (!INDIRECT_TYPE_P (subtype)) |
2d76680f PC |
4535 | return NULL_TREE; |
4536 | ||
4537 | if (TREE_CODE (sub) == ADDR_EXPR) | |
4538 | { | |
4539 | tree op = TREE_OPERAND (sub, 0); | |
4540 | tree optype = TREE_TYPE (op); | |
4541 | ||
4542 | /* *&CONST_DECL -> to the value of the const decl. */ | |
4543 | if (TREE_CODE (op) == CONST_DECL) | |
4544 | return DECL_INITIAL (op); | |
4545 | /* *&p => p; make sure to handle *&"str"[cst] here. */ | |
1a120ec1 | 4546 | if (similar_type_p (optype, type)) |
2d76680f PC |
4547 | { |
4548 | tree fop = fold_read_from_constant_string (op); | |
4549 | if (fop) | |
4550 | return fop; | |
4551 | else | |
4552 | return op; | |
4553 | } | |
0fe2ae29 JJ |
4554 | else |
4555 | return cxx_fold_indirect_ref_1 (loc, type, op, 0, empty_base); | |
2d76680f PC |
4556 | } |
4557 | else if (TREE_CODE (sub) == POINTER_PLUS_EXPR | |
0fe2ae29 | 4558 | && tree_fits_uhwi_p (TREE_OPERAND (sub, 1))) |
2d76680f PC |
4559 | { |
4560 | tree op00 = TREE_OPERAND (sub, 0); | |
4561 | tree op01 = TREE_OPERAND (sub, 1); | |
4562 | ||
4563 | STRIP_NOPS (op00); | |
4564 | if (TREE_CODE (op00) == ADDR_EXPR) | |
0fe2ae29 JJ |
4565 | return cxx_fold_indirect_ref_1 (loc, type, TREE_OPERAND (op00, 0), |
4566 | tree_to_uhwi (op01), empty_base); | |
2d76680f PC |
4567 | } |
4568 | /* *(foo *)fooarrptr => (*fooarrptr)[0] */ | |
4569 | else if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE | |
1a120ec1 | 4570 | && similar_type_p (type, TREE_TYPE (TREE_TYPE (subtype)))) |
2d76680f PC |
4571 | { |
4572 | tree type_domain; | |
4573 | tree min_val = size_zero_node; | |
ebe4bf41 MP |
4574 | tree newsub |
4575 | = cxx_fold_indirect_ref (loc, TREE_TYPE (subtype), sub, NULL); | |
2d76680f PC |
4576 | if (newsub) |
4577 | sub = newsub; | |
4578 | else | |
4579 | sub = build1_loc (loc, INDIRECT_REF, TREE_TYPE (subtype), sub); | |
4580 | type_domain = TYPE_DOMAIN (TREE_TYPE (sub)); | |
4581 | if (type_domain && TYPE_MIN_VALUE (type_domain)) | |
4582 | min_val = TYPE_MIN_VALUE (type_domain); | |
4583 | return build4_loc (loc, ARRAY_REF, type, sub, min_val, NULL_TREE, | |
4584 | NULL_TREE); | |
4585 | } | |
4586 | ||
4587 | return NULL_TREE; | |
4588 | } | |
4589 | ||
4590 | static tree | |
3e605b20 | 4591 | cxx_eval_indirect_ref (const constexpr_ctx *ctx, tree t, |
92a596e8 | 4592 | bool lval, |
2d76680f PC |
4593 | bool *non_constant_p, bool *overflow_p) |
4594 | { | |
4595 | tree orig_op0 = TREE_OPERAND (t, 0); | |
2d76680f | 4596 | bool empty_base = false; |
2d76680f | 4597 | |
cda0a029 JM |
4598 | /* We can handle a MEM_REF like an INDIRECT_REF, if MEM_REF's second |
4599 | operand is an integer-zero. Otherwise reject the MEM_REF for now. */ | |
4600 | ||
4601 | if (TREE_CODE (t) == MEM_REF | |
4602 | && (!TREE_OPERAND (t, 1) || !integer_zerop (TREE_OPERAND (t, 1)))) | |
4603 | { | |
4604 | gcc_assert (ctx->quiet); | |
4605 | *non_constant_p = true; | |
4606 | return t; | |
4607 | } | |
4608 | ||
255a48d6 JM |
4609 | /* First try to simplify it directly. */ |
4610 | tree r = cxx_fold_indirect_ref (EXPR_LOCATION (t), TREE_TYPE (t), orig_op0, | |
4611 | &empty_base); | |
4612 | if (!r) | |
2d76680f | 4613 | { |
255a48d6 JM |
4614 | /* If that didn't work, evaluate the operand first. */ |
4615 | tree op0 = cxx_eval_constant_expression (ctx, orig_op0, | |
4616 | /*lval*/false, non_constant_p, | |
4617 | overflow_p); | |
4618 | /* Don't VERIFY_CONSTANT here. */ | |
4619 | if (*non_constant_p) | |
4620 | return t; | |
4621 | ||
8bada5cd MS |
4622 | if (!lval && integer_zerop (op0)) |
4623 | { | |
4624 | if (!ctx->quiet) | |
4625 | error ("dereferencing a null pointer"); | |
4626 | *non_constant_p = true; | |
4627 | return t; | |
4628 | } | |
4629 | ||
255a48d6 JM |
4630 | r = cxx_fold_indirect_ref (EXPR_LOCATION (t), TREE_TYPE (t), op0, |
4631 | &empty_base); | |
4632 | if (r == NULL_TREE) | |
2d76680f PC |
4633 | { |
4634 | /* We couldn't fold to a constant value. Make sure it's not | |
4635 | something we should have been able to fold. */ | |
255a48d6 JM |
4636 | tree sub = op0; |
4637 | STRIP_NOPS (sub); | |
4638 | if (TREE_CODE (sub) == ADDR_EXPR) | |
4639 | { | |
1a120ec1 | 4640 | gcc_assert (!similar_type_p |
255a48d6 JM |
4641 | (TREE_TYPE (TREE_TYPE (sub)), TREE_TYPE (t))); |
4642 | /* DR 1188 says we don't have to deal with this. */ | |
4643 | if (!ctx->quiet) | |
1a120ec1 JM |
4644 | error_at (cp_expr_loc_or_input_loc (t), |
4645 | "accessing value of %qE through a %qT glvalue in a " | |
4646 | "constant expression", build_fold_indirect_ref (sub), | |
4647 | TREE_TYPE (t)); | |
255a48d6 JM |
4648 | *non_constant_p = true; |
4649 | return t; | |
4650 | } | |
4651 | ||
4652 | if (lval && op0 != orig_op0) | |
4653 | return build1 (INDIRECT_REF, TREE_TYPE (t), op0); | |
4654 | if (!lval) | |
4655 | VERIFY_CONSTANT (t); | |
2d76680f PC |
4656 | return t; |
4657 | } | |
4658 | } | |
4659 | ||
255a48d6 JM |
4660 | r = cxx_eval_constant_expression (ctx, r, |
4661 | lval, non_constant_p, overflow_p); | |
4662 | if (*non_constant_p) | |
4663 | return t; | |
4664 | ||
125db6a1 | 4665 | /* If we're pulling out the value of an empty base, just return an empty |
2d76680f | 4666 | CONSTRUCTOR. */ |
92a596e8 | 4667 | if (empty_base && !lval) |
2d76680f | 4668 | { |
2d76680f PC |
4669 | r = build_constructor (TREE_TYPE (t), NULL); |
4670 | TREE_CONSTANT (r) = true; | |
4671 | } | |
4672 | ||
2d76680f PC |
4673 | return r; |
4674 | } | |
4675 | ||
4676 | /* Complain about R, a VAR_DECL, not being usable in a constant expression. | |
4677 | Shared between potential_constant_expression and | |
4678 | cxx_eval_constant_expression. */ | |
4679 | ||
4680 | static void | |
6821245b | 4681 | non_const_var_error (location_t loc, tree r) |
2d76680f | 4682 | { |
8e007055 | 4683 | auto_diagnostic_group d; |
2d76680f | 4684 | tree type = TREE_TYPE (r); |
8e007055 | 4685 | if (DECL_NAME (r) == heap_uninit_identifier |
815baade JJ |
4686 | || DECL_NAME (r) == heap_identifier |
4687 | || DECL_NAME (r) == heap_vec_uninit_identifier | |
4688 | || DECL_NAME (r) == heap_vec_identifier) | |
8e007055 | 4689 | { |
6821245b JM |
4690 | error_at (loc, "the content of uninitialized storage is not usable " |
4691 | "in a constant expression"); | |
8e007055 JJ |
4692 | inform (DECL_SOURCE_LOCATION (r), "allocated here"); |
4693 | return; | |
4694 | } | |
4695 | if (DECL_NAME (r) == heap_deleted_identifier) | |
4696 | { | |
6821245b JM |
4697 | error_at (loc, "use of allocated storage after deallocation in a " |
4698 | "constant expression"); | |
8e007055 JJ |
4699 | inform (DECL_SOURCE_LOCATION (r), "allocated here"); |
4700 | return; | |
4701 | } | |
6821245b JM |
4702 | error_at (loc, "the value of %qD is not usable in a constant " |
4703 | "expression", r); | |
2d76680f PC |
4704 | /* Avoid error cascade. */ |
4705 | if (DECL_INITIAL (r) == error_mark_node) | |
4706 | return; | |
4707 | if (DECL_DECLARED_CONSTEXPR_P (r)) | |
4708 | inform (DECL_SOURCE_LOCATION (r), | |
4709 | "%qD used in its own initializer", r); | |
4710 | else if (INTEGRAL_OR_ENUMERATION_TYPE_P (type)) | |
4711 | { | |
4712 | if (!CP_TYPE_CONST_P (type)) | |
4713 | inform (DECL_SOURCE_LOCATION (r), | |
4714 | "%q#D is not const", r); | |
4715 | else if (CP_TYPE_VOLATILE_P (type)) | |
4716 | inform (DECL_SOURCE_LOCATION (r), | |
4717 | "%q#D is volatile", r); | |
4718 | else if (!DECL_INITIAL (r) | |
a3e2b438 PP |
4719 | || !TREE_CONSTANT (DECL_INITIAL (r)) |
4720 | || !DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r)) | |
2d76680f PC |
4721 | inform (DECL_SOURCE_LOCATION (r), |
4722 | "%qD was not initialized with a constant " | |
4723 | "expression", r); | |
4724 | else | |
4725 | gcc_unreachable (); | |
4726 | } | |
9f613f06 | 4727 | else if (TYPE_REF_P (type)) |
fd338b13 JM |
4728 | inform (DECL_SOURCE_LOCATION (r), |
4729 | "%qD was not initialized with a constant " | |
4730 | "expression", r); | |
2d76680f PC |
4731 | else |
4732 | { | |
4733 | if (cxx_dialect >= cxx11 && !DECL_DECLARED_CONSTEXPR_P (r)) | |
4734 | inform (DECL_SOURCE_LOCATION (r), | |
4735 | "%qD was not declared %<constexpr%>", r); | |
4736 | else | |
4737 | inform (DECL_SOURCE_LOCATION (r), | |
4738 | "%qD does not have integral or enumeration type", | |
4739 | r); | |
4740 | } | |
4741 | } | |
4742 | ||
4743 | /* Subroutine of cxx_eval_constant_expression. | |
4744 | Like cxx_eval_unary_expression, except for trinary expressions. */ | |
4745 | ||
4746 | static tree | |
3e605b20 | 4747 | cxx_eval_trinary_expression (const constexpr_ctx *ctx, tree t, |
92a596e8 | 4748 | bool lval, |
2d76680f PC |
4749 | bool *non_constant_p, bool *overflow_p) |
4750 | { | |
4751 | int i; | |
4752 | tree args[3]; | |
4753 | tree val; | |
4754 | ||
4755 | for (i = 0; i < 3; i++) | |
4756 | { | |
3e605b20 | 4757 | args[i] = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, i), |
92a596e8 | 4758 | lval, |
5a804683 | 4759 | non_constant_p, overflow_p); |
2d76680f PC |
4760 | VERIFY_CONSTANT (args[i]); |
4761 | } | |
4762 | ||
4763 | val = fold_ternary_loc (EXPR_LOCATION (t), TREE_CODE (t), TREE_TYPE (t), | |
4764 | args[0], args[1], args[2]); | |
4765 | if (val == NULL_TREE) | |
4766 | return t; | |
4767 | VERIFY_CONSTANT (val); | |
4768 | return val; | |
4769 | } | |
4770 | ||
98e5a19a JM |
4771 | /* True if T was declared in a function declared to be constexpr, and |
4772 | therefore potentially constant in C++14. */ | |
4773 | ||
2d76680f PC |
4774 | bool |
4775 | var_in_constexpr_fn (tree t) | |
4776 | { | |
4777 | tree ctx = DECL_CONTEXT (t); | |
98e5a19a | 4778 | return (ctx && TREE_CODE (ctx) == FUNCTION_DECL |
2d76680f PC |
4779 | && DECL_DECLARED_CONSTEXPR_P (ctx)); |
4780 | } | |
4781 | ||
98e5a19a JM |
4782 | /* True if T was declared in a function that might be constexpr: either a |
4783 | function that was declared constexpr, or a C++17 lambda op(). */ | |
4784 | ||
4785 | bool | |
4786 | var_in_maybe_constexpr_fn (tree t) | |
4787 | { | |
7b936140 | 4788 | if (cxx_dialect >= cxx17 |
98e5a19a JM |
4789 | && DECL_FUNCTION_SCOPE_P (t) |
4790 | && LAMBDA_FUNCTION_P (DECL_CONTEXT (t))) | |
4791 | return true; | |
4792 | return var_in_constexpr_fn (t); | |
4793 | } | |
4794 | ||
68d01920 JM |
4795 | /* We're assigning INIT to TARGET. In do_build_copy_constructor and |
4796 | build_over_call we implement trivial copy of a class with tail padding using | |
4797 | assignment of character arrays, which is valid in normal code, but not in | |
4798 | constexpr evaluation. We don't need to worry about clobbering tail padding | |
4799 | in constexpr evaluation, so strip the type punning. */ | |
4800 | ||
4801 | static void | |
4802 | maybe_simplify_trivial_copy (tree &target, tree &init) | |
4803 | { | |
4804 | if (TREE_CODE (target) == MEM_REF | |
4805 | && TREE_CODE (init) == MEM_REF | |
4806 | && TREE_TYPE (target) == TREE_TYPE (init) | |
4807 | && TREE_CODE (TREE_TYPE (target)) == ARRAY_TYPE | |
4808 | && TREE_TYPE (TREE_TYPE (target)) == unsigned_char_type_node) | |
4809 | { | |
4810 | target = build_fold_indirect_ref (TREE_OPERAND (target, 0)); | |
4811 | init = build_fold_indirect_ref (TREE_OPERAND (init, 0)); | |
4812 | } | |
4813 | } | |
4814 | ||
7eb5be6a MP |
4815 | /* Returns true if REF, which is a COMPONENT_REF, has any fields |
4816 | of constant type. This does not check for 'mutable', so the | |
4817 | caller is expected to be mindful of that. */ | |
4818 | ||
4819 | static bool | |
4820 | cref_has_const_field (tree ref) | |
4821 | { | |
4822 | while (TREE_CODE (ref) == COMPONENT_REF) | |
4823 | { | |
4824 | if (CP_TYPE_CONST_P (TREE_TYPE (TREE_OPERAND (ref, 1)))) | |
4825 | return true; | |
4826 | ref = TREE_OPERAND (ref, 0); | |
4827 | } | |
4828 | return false; | |
4829 | } | |
4830 | ||
04e1749c MP |
4831 | /* Return true if we are modifying something that is const during constant |
4832 | expression evaluation. CODE is the code of the statement, OBJ is the | |
4833 | object in question, MUTABLE_P is true if one of the subobjects were | |
4834 | declared mutable. */ | |
4835 | ||
4836 | static bool | |
4837 | modifying_const_object_p (tree_code code, tree obj, bool mutable_p) | |
4838 | { | |
4839 | /* If this is initialization, there's no problem. */ | |
4840 | if (code != MODIFY_EXPR) | |
4841 | return false; | |
4842 | ||
4843 | /* [basic.type.qualifier] "A const object is an object of type | |
4844 | const T or a non-mutable subobject of a const object." */ | |
4845 | if (mutable_p) | |
4846 | return false; | |
4847 | ||
7eb5be6a MP |
4848 | if (TREE_READONLY (obj)) |
4849 | return true; | |
4850 | ||
4851 | if (CP_TYPE_CONST_P (TREE_TYPE (obj))) | |
4852 | { | |
4853 | /* Although a COMPONENT_REF may have a const type, we should | |
4854 | only consider it modifying a const object when any of the | |
4855 | field components is const. This can happen when using | |
4856 | constructs such as const_cast<const T &>(m), making something | |
4857 | const even though it wasn't declared const. */ | |
4858 | if (TREE_CODE (obj) == COMPONENT_REF) | |
4859 | return cref_has_const_field (obj); | |
4860 | else | |
4861 | return true; | |
4862 | } | |
4863 | ||
4864 | return false; | |
04e1749c MP |
4865 | } |
4866 | ||
60813a46 JM |
4867 | /* Evaluate an INIT_EXPR or MODIFY_EXPR. */ |
4868 | ||
4869 | static tree | |
4870 | cxx_eval_store_expression (const constexpr_ctx *ctx, tree t, | |
92a596e8 | 4871 | bool lval, |
60813a46 JM |
4872 | bool *non_constant_p, bool *overflow_p) |
4873 | { | |
4874 | constexpr_ctx new_ctx = *ctx; | |
4875 | ||
58cc255c JM |
4876 | tree init = TREE_OPERAND (t, 1); |
4877 | if (TREE_CLOBBER_P (init)) | |
4878 | /* Just ignore clobbers. */ | |
4879 | return void_node; | |
4880 | ||
60813a46 JM |
4881 | /* First we figure out where we're storing to. */ |
4882 | tree target = TREE_OPERAND (t, 0); | |
68d01920 JM |
4883 | |
4884 | maybe_simplify_trivial_copy (target, init); | |
4885 | ||
3f8e2835 | 4886 | tree type = TREE_TYPE (target); |
e8b3c1bc JM |
4887 | bool preeval = SCALAR_TYPE_P (type) || TREE_CODE (t) == MODIFY_EXPR; |
4888 | if (preeval) | |
4889 | { | |
4890 | /* Evaluate the value to be stored without knowing what object it will be | |
4891 | stored in, so that any side-effects happen first. */ | |
4892 | if (!SCALAR_TYPE_P (type)) | |
4893 | new_ctx.ctor = new_ctx.object = NULL_TREE; | |
4894 | init = cxx_eval_constant_expression (&new_ctx, init, false, | |
4895 | non_constant_p, overflow_p); | |
4896 | if (*non_constant_p) | |
4897 | return t; | |
4898 | } | |
60813a46 | 4899 | |
d0aa42d2 JM |
4900 | bool evaluated = false; |
4901 | if (lval) | |
3f8e2835 | 4902 | { |
d0aa42d2 JM |
4903 | /* If we want to return a reference to the target, we need to evaluate it |
4904 | as a whole; otherwise, only evaluate the innermost piece to avoid | |
4905 | building up unnecessary *_REFs. */ | |
4906 | target = cxx_eval_constant_expression (ctx, target, true, | |
4907 | non_constant_p, overflow_p); | |
4908 | evaluated = true; | |
4909 | if (*non_constant_p) | |
4910 | return t; | |
3f8e2835 JM |
4911 | } |
4912 | ||
043666e0 | 4913 | /* Find the underlying variable. */ |
cd9cf97b | 4914 | releasing_vec refs; |
60813a46 | 4915 | tree object = NULL_TREE; |
04e1749c MP |
4916 | /* If we're modifying a const object, save it. */ |
4917 | tree const_object_being_modified = NULL_TREE; | |
4918 | bool mutable_p = false; | |
60813a46 JM |
4919 | for (tree probe = target; object == NULL_TREE; ) |
4920 | { | |
4921 | switch (TREE_CODE (probe)) | |
4922 | { | |
4923 | case BIT_FIELD_REF: | |
4924 | case COMPONENT_REF: | |
4925 | case ARRAY_REF: | |
043666e0 JM |
4926 | { |
4927 | tree ob = TREE_OPERAND (probe, 0); | |
4928 | tree elt = TREE_OPERAND (probe, 1); | |
7d349dd8 | 4929 | if (TREE_CODE (elt) == FIELD_DECL && DECL_MUTABLE_P (elt)) |
04e1749c | 4930 | mutable_p = true; |
043666e0 JM |
4931 | if (TREE_CODE (probe) == ARRAY_REF) |
4932 | { | |
4933 | elt = eval_and_check_array_index (ctx, probe, false, | |
4934 | non_constant_p, overflow_p); | |
4935 | if (*non_constant_p) | |
4936 | return t; | |
4937 | } | |
0f184800 MP |
4938 | /* We don't check modifying_const_object_p for ARRAY_REFs. Given |
4939 | "int a[10]", an ARRAY_REF "a[2]" can be "const int", even though | |
4940 | the array isn't const. Instead, check "a" in the next iteration; | |
4941 | that will detect modifying "const int a[10]". */ | |
4942 | else if (evaluated | |
4943 | && modifying_const_object_p (TREE_CODE (t), probe, | |
4944 | mutable_p) | |
4945 | && const_object_being_modified == NULL_TREE) | |
4946 | const_object_being_modified = probe; | |
043666e0 JM |
4947 | vec_safe_push (refs, elt); |
4948 | vec_safe_push (refs, TREE_TYPE (probe)); | |
4949 | probe = ob; | |
4950 | } | |
60813a46 JM |
4951 | break; |
4952 | ||
4953 | default: | |
d0aa42d2 JM |
4954 | if (evaluated) |
4955 | object = probe; | |
4956 | else | |
4957 | { | |
4958 | probe = cxx_eval_constant_expression (ctx, probe, true, | |
4959 | non_constant_p, overflow_p); | |
4960 | evaluated = true; | |
4961 | if (*non_constant_p) | |
4962 | return t; | |
4963 | } | |
4964 | break; | |
60813a46 JM |
4965 | } |
4966 | } | |
4967 | ||
04e1749c MP |
4968 | if (modifying_const_object_p (TREE_CODE (t), object, mutable_p) |
4969 | && const_object_being_modified == NULL_TREE) | |
4970 | const_object_being_modified = object; | |
4971 | ||
60813a46 JM |
4972 | /* And then find/build up our initializer for the path to the subobject |
4973 | we're initializing. */ | |
a1408b7e | 4974 | tree *valp; |
077dd9b3 | 4975 | if (DECL_P (object)) |
8e007055 | 4976 | valp = ctx->global->values.get (object); |
a1408b7e JM |
4977 | else |
4978 | valp = NULL; | |
60813a46 JM |
4979 | if (!valp) |
4980 | { | |
4981 | /* A constant-expression cannot modify objects from outside the | |
4982 | constant-expression. */ | |
2b3ab879 | 4983 | if (!ctx->quiet) |
64d6d399 | 4984 | error ("modification of %qE is not a constant expression", object); |
60813a46 JM |
4985 | *non_constant_p = true; |
4986 | return t; | |
4987 | } | |
3f8e2835 | 4988 | type = TREE_TYPE (object); |
c75ce530 | 4989 | bool no_zero_init = true; |
2d63bc39 | 4990 | |
37244b21 PP |
4991 | releasing_vec ctors, indexes; |
4992 | auto_vec<int> index_pos_hints; | |
4993 | bool activated_union_member_p = false; | |
276a52d5 | 4994 | while (!refs->is_empty ()) |
60813a46 JM |
4995 | { |
4996 | if (*valp == NULL_TREE) | |
4997 | { | |
4998 | *valp = build_constructor (type, NULL); | |
e8c48716 | 4999 | CONSTRUCTOR_NO_CLEARING (*valp) = no_zero_init; |
60813a46 | 5000 | } |
d6b46fca NS |
5001 | else if (TREE_CODE (*valp) == STRING_CST) |
5002 | { | |
5003 | /* An array was initialized with a string constant, and now | |
5004 | we're writing into one of its elements. Explode the | |
5005 | single initialization into a set of element | |
5006 | initializations. */ | |
5007 | gcc_assert (TREE_CODE (type) == ARRAY_TYPE); | |
5008 | ||
5009 | tree string = *valp; | |
5010 | tree elt_type = TREE_TYPE (type); | |
5011 | unsigned chars_per_elt = (TYPE_PRECISION (elt_type) | |
5012 | / TYPE_PRECISION (char_type_node)); | |
5013 | unsigned num_elts = TREE_STRING_LENGTH (string) / chars_per_elt; | |
5014 | tree ary_ctor = build_constructor (type, NULL); | |
5015 | ||
5016 | vec_safe_reserve (CONSTRUCTOR_ELTS (ary_ctor), num_elts); | |
5017 | for (unsigned ix = 0; ix != num_elts; ix++) | |
5018 | { | |
5019 | constructor_elt elt = | |
5020 | { | |
5021 | build_int_cst (size_type_node, ix), | |
5022 | extract_string_elt (string, chars_per_elt, ix) | |
5023 | }; | |
5024 | CONSTRUCTOR_ELTS (ary_ctor)->quick_push (elt); | |
5025 | } | |
5026 | ||
5027 | *valp = ary_ctor; | |
5028 | } | |
5029 | ||
c75ce530 JM |
5030 | /* If the value of object is already zero-initialized, any new ctors for |
5031 | subobjects will also be zero-initialized. */ | |
e8c48716 | 5032 | no_zero_init = CONSTRUCTOR_NO_CLEARING (*valp); |
60813a46 | 5033 | |
ceaaf873 | 5034 | enum tree_code code = TREE_CODE (type); |
60813a46 | 5035 | type = refs->pop(); |
ceaaf873 | 5036 | tree index = refs->pop(); |
60813a46 | 5037 | |
37244b21 PP |
5038 | if (code == UNION_TYPE && CONSTRUCTOR_NELTS (*valp) |
5039 | && CONSTRUCTOR_ELT (*valp, 0)->index != index) | |
ceaaf873 | 5040 | { |
b04445d4 | 5041 | if (cxx_dialect < cxx20) |
ed4ec9ce | 5042 | { |
37244b21 PP |
5043 | if (!ctx->quiet) |
5044 | error_at (cp_expr_loc_or_input_loc (t), | |
5045 | "change of the active member of a union " | |
5046 | "from %qD to %qD", | |
5047 | CONSTRUCTOR_ELT (*valp, 0)->index, | |
5048 | index); | |
5049 | *non_constant_p = true; | |
ed4ec9ce | 5050 | } |
37244b21 PP |
5051 | else if (TREE_CODE (t) == MODIFY_EXPR |
5052 | && CONSTRUCTOR_NO_CLEARING (*valp)) | |
ceaaf873 | 5053 | { |
37244b21 PP |
5054 | /* Diagnose changing the active union member while the union |
5055 | is in the process of being initialized. */ | |
5056 | if (!ctx->quiet) | |
5057 | error_at (cp_expr_loc_or_input_loc (t), | |
5058 | "change of the active member of a union " | |
5059 | "from %qD to %qD during initialization", | |
5060 | CONSTRUCTOR_ELT (*valp, 0)->index, | |
5061 | index); | |
5062 | *non_constant_p = true; | |
ceaaf873 | 5063 | } |
37244b21 PP |
5064 | no_zero_init = true; |
5065 | } | |
88504f34 | 5066 | |
37244b21 PP |
5067 | vec_safe_push (ctors, *valp); |
5068 | vec_safe_push (indexes, index); | |
88504f34 | 5069 | |
37244b21 | 5070 | constructor_elt *cep |
077dd9b3 | 5071 | = get_or_insert_ctor_field (*valp, index); |
37244b21 PP |
5072 | index_pos_hints.safe_push (cep - CONSTRUCTOR_ELTS (*valp)->begin()); |
5073 | ||
5074 | if (code == UNION_TYPE) | |
5075 | activated_union_member_p = true; | |
b599bf9d | 5076 | |
60813a46 JM |
5077 | valp = &cep->value; |
5078 | } | |
60813a46 | 5079 | |
04e1749c MP |
5080 | /* Detect modifying a constant object in constexpr evaluation. |
5081 | We have found a const object that is being modified. Figure out | |
5082 | if we need to issue an error. Consider | |
5083 | ||
5084 | struct A { | |
5085 | int n; | |
5086 | constexpr A() : n(1) { n = 2; } // #1 | |
5087 | }; | |
5088 | struct B { | |
5089 | const A a; | |
5090 | constexpr B() { a.n = 3; } // #2 | |
5091 | }; | |
5092 | constexpr B b{}; | |
5093 | ||
5094 | #1 is OK, since we're modifying an object under construction, but | |
5095 | #2 is wrong, since "a" is const and has been fully constructed. | |
5096 | To track it, we use the TREE_READONLY bit in the object's CONSTRUCTOR | |
5097 | which means that the object is read-only. For the example above, the | |
5098 | *ctors stack at the point of #2 will look like: | |
5099 | ||
5100 | ctors[0] = {.a={.n=2}} TREE_READONLY = 0 | |
5101 | ctors[1] = {.n=2} TREE_READONLY = 1 | |
5102 | ||
5103 | and we're modifying "b.a", so we search the stack and see if the | |
5104 | constructor for "b.a" has already run. */ | |
5105 | if (const_object_being_modified) | |
5106 | { | |
5107 | bool fail = false; | |
276a52d5 JJ |
5108 | tree const_objtype |
5109 | = strip_array_types (TREE_TYPE (const_object_being_modified)); | |
5110 | if (!CLASS_TYPE_P (const_objtype)) | |
04e1749c MP |
5111 | fail = true; |
5112 | else | |
5113 | { | |
5114 | /* [class.ctor]p5 "A constructor can be invoked for a const, | |
5115 | volatile, or const volatile object. const and volatile | |
5116 | semantics are not applied on an object under construction. | |
5117 | They come into effect when the constructor for the most | |
5118 | derived object ends." */ | |
5119 | tree elt; | |
5120 | unsigned int i; | |
5121 | FOR_EACH_VEC_ELT (*ctors, i, elt) | |
5122 | if (same_type_ignoring_top_level_qualifiers_p | |
5123 | (TREE_TYPE (const_object_being_modified), TREE_TYPE (elt))) | |
5124 | { | |
5125 | fail = TREE_READONLY (elt); | |
5126 | break; | |
5127 | } | |
5128 | } | |
5129 | if (fail) | |
5130 | { | |
5131 | if (!ctx->quiet) | |
5132 | modifying_const_object_error (t, const_object_being_modified); | |
5133 | *non_constant_p = true; | |
5134 | return t; | |
5135 | } | |
5136 | } | |
5137 | ||
e8b3c1bc | 5138 | if (!preeval) |
60813a46 JM |
5139 | { |
5140 | /* Create a new CONSTRUCTOR in case evaluation of the initializer | |
5141 | wants to modify it. */ | |
acb2970c | 5142 | if (*valp == NULL_TREE) |
73a84269 | 5143 | { |
664beaf2 | 5144 | *valp = build_constructor (type, NULL); |
e8c48716 | 5145 | CONSTRUCTOR_NO_CLEARING (*valp) = no_zero_init; |
73a84269 | 5146 | } |
664beaf2 | 5147 | new_ctx.ctor = *valp; |
60813a46 | 5148 | new_ctx.object = target; |
10d2f801 JM |
5149 | /* Avoid temporary materialization when initializing from a TARGET_EXPR. |
5150 | We don't need to mess with AGGR_EXPR_SLOT/VEC_INIT_EXPR_SLOT because | |
5151 | expansion of those trees uses ctx instead. */ | |
5152 | if (TREE_CODE (init) == TARGET_EXPR) | |
5153 | if (tree tinit = TARGET_EXPR_INITIAL (init)) | |
5154 | init = tinit; | |
e8b3c1bc JM |
5155 | init = cxx_eval_constant_expression (&new_ctx, init, false, |
5156 | non_constant_p, overflow_p); | |
37244b21 PP |
5157 | /* The hash table might have moved since the get earlier, and the |
5158 | initializer might have mutated the underlying CONSTRUCTORs, so we must | |
5159 | recompute VALP. */ | |
5160 | valp = ctx->global->values.get (object); | |
5161 | for (unsigned i = 0; i < vec_safe_length (indexes); i++) | |
5162 | { | |
5163 | constructor_elt *cep | |
5164 | = get_or_insert_ctor_field (*valp, indexes[i], index_pos_hints[i]); | |
5165 | valp = &cep->value; | |
5166 | } | |
60813a46 JM |
5167 | } |
5168 | ||
7574c916 | 5169 | /* Don't share a CONSTRUCTOR that might be changed later. */ |
0146e25f | 5170 | init = unshare_constructor (init); |
d96e8407 | 5171 | |
e8b3c1bc JM |
5172 | if (*valp && TREE_CODE (*valp) == CONSTRUCTOR |
5173 | && TREE_CODE (init) == CONSTRUCTOR) | |
acb2970c | 5174 | { |
d96e8407 JM |
5175 | /* An outer ctx->ctor might be pointing to *valp, so replace |
5176 | its contents. */ | |
d0aa42d2 JM |
5177 | if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (init), |
5178 | TREE_TYPE (*valp))) | |
5179 | { | |
5180 | /* For initialization of an empty base, the original target will be | |
5181 | *(base*)this, evaluation of which resolves to the object | |
5182 | argument, which has the derived type rather than the base type. In | |
5183 | this situation, just evaluate the initializer and return, since | |
5184 | there's no actual data to store. */ | |
5185 | gcc_assert (is_empty_class (TREE_TYPE (init)) && !lval); | |
5186 | return init; | |
5187 | } | |
d96e8407 JM |
5188 | CONSTRUCTOR_ELTS (*valp) = CONSTRUCTOR_ELTS (init); |
5189 | TREE_CONSTANT (*valp) = TREE_CONSTANT (init); | |
5190 | TREE_SIDE_EFFECTS (*valp) = TREE_SIDE_EFFECTS (init); | |
e8c48716 JM |
5191 | CONSTRUCTOR_NO_CLEARING (*valp) |
5192 | = CONSTRUCTOR_NO_CLEARING (init); | |
acb2970c | 5193 | } |
60813a46 | 5194 | else |
d96e8407 | 5195 | *valp = init; |
2d63bc39 | 5196 | |
7eb5be6a MP |
5197 | /* After initialization, 'const' semantics apply to the value of the |
5198 | object. Make a note of this fact by marking the CONSTRUCTOR | |
5199 | TREE_READONLY. */ | |
5200 | if (TREE_CODE (t) == INIT_EXPR | |
5201 | && TREE_CODE (*valp) == CONSTRUCTOR | |
5202 | && TYPE_READONLY (type)) | |
64da1b76 PP |
5203 | { |
5204 | if (INDIRECT_REF_P (target) | |
5205 | && (is_this_parameter | |
5206 | (tree_strip_nop_conversions (TREE_OPERAND (target, 0))))) | |
5207 | /* We've just initialized '*this' (perhaps via the target | |
5208 | constructor of a delegating constructor). Leave it up to the | |
5209 | caller that set 'this' to set TREE_READONLY appropriately. */ | |
5210 | gcc_checking_assert (same_type_ignoring_top_level_qualifiers_p | |
5211 | (TREE_TYPE (target), type)); | |
5212 | else | |
5213 | TREE_READONLY (*valp) = true; | |
5214 | } | |
7eb5be6a | 5215 | |
d96e8407 JM |
5216 | /* Update TREE_CONSTANT and TREE_SIDE_EFFECTS on enclosing |
5217 | CONSTRUCTORs, if any. */ | |
5218 | tree elt; | |
5219 | unsigned i; | |
5220 | bool c = TREE_CONSTANT (init); | |
5221 | bool s = TREE_SIDE_EFFECTS (init); | |
37244b21 | 5222 | if (!c || s || activated_union_member_p) |
cd9cf97b | 5223 | FOR_EACH_VEC_ELT (*ctors, i, elt) |
d96e8407 JM |
5224 | { |
5225 | if (!c) | |
5226 | TREE_CONSTANT (elt) = false; | |
5227 | if (s) | |
5228 | TREE_SIDE_EFFECTS (elt) = true; | |
b599bf9d PP |
5229 | /* Clear CONSTRUCTOR_NO_CLEARING since we've activated a member of |
5230 | this union. */ | |
5231 | if (TREE_CODE (TREE_TYPE (elt)) == UNION_TYPE) | |
5232 | CONSTRUCTOR_NO_CLEARING (elt) = false; | |
d96e8407 | 5233 | } |
60813a46 JM |
5234 | |
5235 | if (*non_constant_p) | |
5236 | return t; | |
92a596e8 | 5237 | else if (lval) |
60813a46 JM |
5238 | return target; |
5239 | else | |
3bdf0a9b | 5240 | return init; |
60813a46 JM |
5241 | } |
5242 | ||
5243 | /* Evaluate a ++ or -- expression. */ | |
5244 | ||
5245 | static tree | |
5246 | cxx_eval_increment_expression (const constexpr_ctx *ctx, tree t, | |
92a596e8 | 5247 | bool lval, |
60813a46 JM |
5248 | bool *non_constant_p, bool *overflow_p) |
5249 | { | |
5250 | enum tree_code code = TREE_CODE (t); | |
5251 | tree type = TREE_TYPE (t); | |
5252 | tree op = TREE_OPERAND (t, 0); | |
5253 | tree offset = TREE_OPERAND (t, 1); | |
5254 | gcc_assert (TREE_CONSTANT (offset)); | |
5255 | ||
d85569f6 MP |
5256 | /* OFFSET is constant, but perhaps not constant enough. We need to |
5257 | e.g. bash FLOAT_EXPRs to REAL_CSTs. */ | |
5258 | offset = fold_simple (offset); | |
5259 | ||
60813a46 | 5260 | /* The operand as an lvalue. */ |
2b3ab879 | 5261 | op = cxx_eval_constant_expression (ctx, op, true, |
5a804683 | 5262 | non_constant_p, overflow_p); |
60813a46 JM |
5263 | |
5264 | /* The operand as an rvalue. */ | |
84dd815f JM |
5265 | tree val |
5266 | = cxx_eval_constant_expression (ctx, op, false, | |
5267 | non_constant_p, overflow_p); | |
caee690e JM |
5268 | /* Don't VERIFY_CONSTANT if this might be dealing with a pointer to |
5269 | a local array in a constexpr function. */ | |
71a93b08 | 5270 | bool ptr = INDIRECT_TYPE_P (TREE_TYPE (val)); |
caee690e JM |
5271 | if (!ptr) |
5272 | VERIFY_CONSTANT (val); | |
60813a46 JM |
5273 | |
5274 | /* The modified value. */ | |
5275 | bool inc = (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR); | |
ac2f8d26 | 5276 | tree mod; |
71a93b08 | 5277 | if (INDIRECT_TYPE_P (type)) |
ac2f8d26 JM |
5278 | { |
5279 | /* The middle end requires pointers to use POINTER_PLUS_EXPR. */ | |
5280 | offset = convert_to_ptrofftype (offset); | |
5281 | if (!inc) | |
5282 | offset = fold_build1 (NEGATE_EXPR, TREE_TYPE (offset), offset); | |
5283 | mod = fold_build2 (POINTER_PLUS_EXPR, type, val, offset); | |
5284 | } | |
5285 | else | |
5286 | mod = fold_build2 (inc ? PLUS_EXPR : MINUS_EXPR, type, val, offset); | |
caee690e JM |
5287 | if (!ptr) |
5288 | VERIFY_CONSTANT (mod); | |
60813a46 JM |
5289 | |
5290 | /* Storing the modified value. */ | |
04e1749c MP |
5291 | tree store = build2_loc (cp_expr_loc_or_loc (t, input_location), |
5292 | MODIFY_EXPR, type, op, mod); | |
2b3ab879 | 5293 | cxx_eval_constant_expression (ctx, store, |
5a804683 | 5294 | true, non_constant_p, overflow_p); |
ecdcd560 | 5295 | ggc_free (store); |
60813a46 JM |
5296 | |
5297 | /* And the value of the expression. */ | |
5298 | if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR) | |
5299 | { | |
5300 | /* Prefix ops are lvalues. */ | |
92a596e8 | 5301 | if (lval) |
60813a46 JM |
5302 | return op; |
5303 | else | |
5304 | /* But we optimize when the caller wants an rvalue. */ | |
5305 | return mod; | |
5306 | } | |
5307 | else | |
5308 | /* Postfix ops are rvalues. */ | |
5309 | return val; | |
5310 | } | |
5311 | ||
56632b27 JM |
5312 | /* Predicates for the meaning of *jump_target. */ |
5313 | ||
5314 | static bool | |
5315 | returns (tree *jump_target) | |
5316 | { | |
5317 | return *jump_target | |
d49318d9 PC |
5318 | && (TREE_CODE (*jump_target) == RETURN_EXPR |
5319 | || (TREE_CODE (*jump_target) == LABEL_DECL | |
5320 | && LABEL_DECL_CDTOR (*jump_target))); | |
56632b27 JM |
5321 | } |
5322 | ||
5323 | static bool | |
5324 | breaks (tree *jump_target) | |
5325 | { | |
5326 | return *jump_target | |
06ec22b7 JM |
5327 | && ((TREE_CODE (*jump_target) == LABEL_DECL |
5328 | && LABEL_DECL_BREAK (*jump_target)) | |
3075affd | 5329 | || TREE_CODE (*jump_target) == BREAK_STMT |
06ec22b7 | 5330 | || TREE_CODE (*jump_target) == EXIT_EXPR); |
56632b27 JM |
5331 | } |
5332 | ||
5333 | static bool | |
5334 | continues (tree *jump_target) | |
5335 | { | |
5336 | return *jump_target | |
3075affd JM |
5337 | && ((TREE_CODE (*jump_target) == LABEL_DECL |
5338 | && LABEL_DECL_CONTINUE (*jump_target)) | |
5339 | || TREE_CODE (*jump_target) == CONTINUE_STMT); | |
5340 | ||
56632b27 JM |
5341 | } |
5342 | ||
5343 | static bool | |
5344 | switches (tree *jump_target) | |
5345 | { | |
5346 | return *jump_target | |
5347 | && TREE_CODE (*jump_target) == INTEGER_CST; | |
5348 | } | |
5349 | ||
5350 | /* Subroutine of cxx_eval_statement_list. Determine whether the statement | |
4b390698 JJ |
5351 | STMT matches *jump_target. If we're looking for a case label and we see |
5352 | the default label, note it in ctx->css_state. */ | |
56632b27 JM |
5353 | |
5354 | static bool | |
4b390698 | 5355 | label_matches (const constexpr_ctx *ctx, tree *jump_target, tree stmt) |
56632b27 | 5356 | { |
56632b27 JM |
5357 | switch (TREE_CODE (*jump_target)) |
5358 | { | |
5359 | case LABEL_DECL: | |
5360 | if (TREE_CODE (stmt) == LABEL_EXPR | |
5361 | && LABEL_EXPR_LABEL (stmt) == *jump_target) | |
5362 | return true; | |
5363 | break; | |
5364 | ||
5365 | case INTEGER_CST: | |
5366 | if (TREE_CODE (stmt) == CASE_LABEL_EXPR) | |
5367 | { | |
4b390698 | 5368 | gcc_assert (ctx->css_state != NULL); |
56632b27 | 5369 | if (!CASE_LOW (stmt)) |
4b390698 JJ |
5370 | { |
5371 | /* default: should appear just once in a SWITCH_EXPR | |
5372 | body (excluding nested SWITCH_EXPR). */ | |
5373 | gcc_assert (*ctx->css_state != css_default_seen); | |
5374 | /* When evaluating SWITCH_EXPR body for the second time, | |
5375 | return true for the default: label. */ | |
5376 | if (*ctx->css_state == css_default_processing) | |
5377 | return true; | |
5378 | *ctx->css_state = css_default_seen; | |
5379 | } | |
385ed708 JJ |
5380 | else if (CASE_HIGH (stmt)) |
5381 | { | |
5382 | if (tree_int_cst_le (CASE_LOW (stmt), *jump_target) | |
5383 | && tree_int_cst_le (*jump_target, CASE_HIGH (stmt))) | |
5384 | return true; | |
5385 | } | |
56632b27 JM |
5386 | else if (tree_int_cst_equal (*jump_target, CASE_LOW (stmt))) |
5387 | return true; | |
5388 | } | |
5389 | break; | |
5390 | ||
43574e4f JJ |
5391 | case BREAK_STMT: |
5392 | case CONTINUE_STMT: | |
5393 | /* These two are handled directly in cxx_eval_loop_expr by testing | |
5394 | breaks (jump_target) or continues (jump_target). */ | |
5395 | break; | |
5396 | ||
56632b27 JM |
5397 | default: |
5398 | gcc_unreachable (); | |
5399 | } | |
5400 | return false; | |
5401 | } | |
5402 | ||
5403 | /* Evaluate a STATEMENT_LIST for side-effects. Handles various jump | |
5404 | semantics, for switch, break, continue, and return. */ | |
5405 | ||
5406 | static tree | |
5407 | cxx_eval_statement_list (const constexpr_ctx *ctx, tree t, | |
56632b27 JM |
5408 | bool *non_constant_p, bool *overflow_p, |
5409 | tree *jump_target) | |
5410 | { | |
5411 | tree_stmt_iterator i; | |
58611fb6 | 5412 | tree local_target; |
345edb37 JJ |
5413 | /* In a statement-expression we want to return the last value. |
5414 | For empty statement expression return void_node. */ | |
5415 | tree r = void_node; | |
58611fb6 JM |
5416 | if (!jump_target) |
5417 | { | |
5418 | local_target = NULL_TREE; | |
5419 | jump_target = &local_target; | |
5420 | } | |
56632b27 JM |
5421 | for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i)) |
5422 | { | |
56632b27 | 5423 | tree stmt = tsi_stmt (i); |
0250ba58 MP |
5424 | /* We've found a continue, so skip everything until we reach |
5425 | the label its jumping to. */ | |
5426 | if (continues (jump_target)) | |
5427 | { | |
5428 | if (label_matches (ctx, jump_target, stmt)) | |
5429 | /* Found it. */ | |
5430 | *jump_target = NULL_TREE; | |
5431 | else | |
5432 | continue; | |
5433 | } | |
6ef72c36 JJ |
5434 | if (TREE_CODE (stmt) == DEBUG_BEGIN_STMT) |
5435 | continue; | |
58611fb6 JM |
5436 | r = cxx_eval_constant_expression (ctx, stmt, false, |
5437 | non_constant_p, overflow_p, | |
5438 | jump_target); | |
56632b27 JM |
5439 | if (*non_constant_p) |
5440 | break; | |
5441 | if (returns (jump_target) || breaks (jump_target)) | |
5442 | break; | |
5443 | } | |
ce36ba09 JM |
5444 | if (*jump_target && jump_target == &local_target) |
5445 | { | |
5446 | /* We aren't communicating the jump to our caller, so give up. We don't | |
5447 | need to support evaluation of jumps out of statement-exprs. */ | |
5448 | if (!ctx->quiet) | |
f9d0ca40 | 5449 | error_at (cp_expr_loc_or_input_loc (r), |
ce36ba09 JM |
5450 | "statement is not a constant expression"); |
5451 | *non_constant_p = true; | |
5452 | } | |
58611fb6 | 5453 | return r; |
56632b27 JM |
5454 | } |
5455 | ||
5456 | /* Evaluate a LOOP_EXPR for side-effects. Handles break and return | |
5457 | semantics; continue semantics are covered by cxx_eval_statement_list. */ | |
5458 | ||
5459 | static tree | |
5460 | cxx_eval_loop_expr (const constexpr_ctx *ctx, tree t, | |
56632b27 JM |
5461 | bool *non_constant_p, bool *overflow_p, |
5462 | tree *jump_target) | |
5463 | { | |
39dce2b7 | 5464 | constexpr_ctx new_ctx = *ctx; |
8e007055 JJ |
5465 | tree local_target; |
5466 | if (!jump_target) | |
5467 | { | |
5468 | local_target = NULL_TREE; | |
5469 | jump_target = &local_target; | |
5470 | } | |
39dce2b7 | 5471 | |
43574e4f | 5472 | tree body, cond = NULL_TREE, expr = NULL_TREE; |
5ec2cd9f | 5473 | int count = 0; |
43574e4f JJ |
5474 | switch (TREE_CODE (t)) |
5475 | { | |
5476 | case LOOP_EXPR: | |
5477 | body = LOOP_EXPR_BODY (t); | |
5478 | break; | |
5479 | case DO_STMT: | |
5480 | body = DO_BODY (t); | |
5481 | cond = DO_COND (t); | |
5482 | break; | |
5483 | case WHILE_STMT: | |
5484 | body = WHILE_BODY (t); | |
5485 | cond = WHILE_COND (t); | |
5486 | count = -1; | |
5487 | break; | |
5488 | case FOR_STMT: | |
5489 | if (FOR_INIT_STMT (t)) | |
5490 | cxx_eval_constant_expression (ctx, FOR_INIT_STMT (t), /*lval*/false, | |
5491 | non_constant_p, overflow_p, jump_target); | |
5492 | if (*non_constant_p) | |
5493 | return NULL_TREE; | |
5494 | body = FOR_BODY (t); | |
5495 | cond = FOR_COND (t); | |
5496 | expr = FOR_EXPR (t); | |
5497 | count = -1; | |
5498 | break; | |
5499 | default: | |
5500 | gcc_unreachable (); | |
5501 | } | |
0ee28590 | 5502 | auto_vec<tree, 10> save_exprs; |
43574e4f | 5503 | new_ctx.save_exprs = &save_exprs; |
d259b234 | 5504 | do |
56632b27 | 5505 | { |
43574e4f JJ |
5506 | if (count != -1) |
5507 | { | |
5508 | if (body) | |
5509 | cxx_eval_constant_expression (&new_ctx, body, /*lval*/false, | |
5510 | non_constant_p, overflow_p, | |
5511 | jump_target); | |
5512 | if (breaks (jump_target)) | |
5513 | { | |
5514 | *jump_target = NULL_TREE; | |
5515 | break; | |
5516 | } | |
39dce2b7 | 5517 | |
43574e4f JJ |
5518 | if (TREE_CODE (t) != LOOP_EXPR && continues (jump_target)) |
5519 | *jump_target = NULL_TREE; | |
5520 | ||
5521 | if (expr) | |
5522 | cxx_eval_constant_expression (&new_ctx, expr, /*lval*/false, | |
5523 | non_constant_p, overflow_p, | |
5524 | jump_target); | |
5525 | } | |
5526 | ||
5527 | if (cond) | |
5528 | { | |
5529 | tree res | |
5530 | = cxx_eval_constant_expression (&new_ctx, cond, /*lval*/false, | |
5531 | non_constant_p, overflow_p, | |
5532 | jump_target); | |
5533 | if (res) | |
5534 | { | |
5535 | if (verify_constant (res, ctx->quiet, non_constant_p, | |
5536 | overflow_p)) | |
5537 | break; | |
5538 | if (integer_zerop (res)) | |
5539 | break; | |
5540 | } | |
5541 | else | |
5542 | gcc_assert (*jump_target); | |
5543 | } | |
39dce2b7 | 5544 | |
ee1de08d | 5545 | /* Forget saved values of SAVE_EXPRs and TARGET_EXPRs. */ |
0ee28590 JJ |
5546 | unsigned int i; |
5547 | tree save_expr; | |
5548 | FOR_EACH_VEC_ELT (save_exprs, i, save_expr) | |
8e007055 | 5549 | ctx->global->values.remove (save_expr); |
0ee28590 | 5550 | save_exprs.truncate (0); |
43574e4f | 5551 | |
5ec2cd9f JM |
5552 | if (++count >= constexpr_loop_limit) |
5553 | { | |
5554 | if (!ctx->quiet) | |
f9d0ca40 | 5555 | error_at (cp_expr_loc_or_input_loc (t), |
84fa214d | 5556 | "%<constexpr%> loop iteration count exceeds limit of %d " |
a3f9f006 | 5557 | "(use %<-fconstexpr-loop-limit=%> to increase the limit)", |
5ec2cd9f JM |
5558 | constexpr_loop_limit); |
5559 | *non_constant_p = true; | |
5560 | break; | |
5561 | } | |
56632b27 | 5562 | } |
4b390698 JJ |
5563 | while (!returns (jump_target) |
5564 | && !breaks (jump_target) | |
43574e4f JJ |
5565 | && !continues (jump_target) |
5566 | && (!switches (jump_target) || count == 0) | |
4b390698 | 5567 | && !*non_constant_p); |
d259b234 | 5568 | |
ee1de08d | 5569 | /* Forget saved values of SAVE_EXPRs and TARGET_EXPRs. */ |
0ee28590 JJ |
5570 | unsigned int i; |
5571 | tree save_expr; | |
5572 | FOR_EACH_VEC_ELT (save_exprs, i, save_expr) | |
8e007055 | 5573 | ctx->global->values.remove (save_expr); |
39dce2b7 | 5574 | |
56632b27 JM |
5575 | return NULL_TREE; |
5576 | } | |
5577 | ||
5578 | /* Evaluate a SWITCH_EXPR for side-effects. Handles switch and break jump | |
5579 | semantics. */ | |
5580 | ||
5581 | static tree | |
5582 | cxx_eval_switch_expr (const constexpr_ctx *ctx, tree t, | |
56632b27 JM |
5583 | bool *non_constant_p, bool *overflow_p, |
5584 | tree *jump_target) | |
5585 | { | |
43574e4f JJ |
5586 | tree cond |
5587 | = TREE_CODE (t) == SWITCH_STMT ? SWITCH_STMT_COND (t) : SWITCH_COND (t); | |
2b3ab879 | 5588 | cond = cxx_eval_constant_expression (ctx, cond, false, |
5a804683 | 5589 | non_constant_p, overflow_p); |
56632b27 JM |
5590 | VERIFY_CONSTANT (cond); |
5591 | *jump_target = cond; | |
5592 | ||
43574e4f JJ |
5593 | tree body |
5594 | = TREE_CODE (t) == SWITCH_STMT ? SWITCH_STMT_BODY (t) : SWITCH_BODY (t); | |
4b390698 JJ |
5595 | constexpr_ctx new_ctx = *ctx; |
5596 | constexpr_switch_state css = css_default_not_seen; | |
5597 | new_ctx.css_state = &css; | |
5598 | cxx_eval_constant_expression (&new_ctx, body, false, | |
5599 | non_constant_p, overflow_p, jump_target); | |
5600 | if (switches (jump_target) && css == css_default_seen) | |
5601 | { | |
5602 | /* If the SWITCH_EXPR body has default: label, process it once again, | |
5603 | this time instructing label_matches to return true for default: | |
5604 | label on switches (jump_target). */ | |
5605 | css = css_default_processing; | |
5606 | cxx_eval_constant_expression (&new_ctx, body, false, | |
5607 | non_constant_p, overflow_p, jump_target); | |
5608 | } | |
56632b27 JM |
5609 | if (breaks (jump_target) || switches (jump_target)) |
5610 | *jump_target = NULL_TREE; | |
5611 | return NULL_TREE; | |
5612 | } | |
5613 | ||
89262ec6 JM |
5614 | /* Find the object of TYPE under initialization in CTX. */ |
5615 | ||
5616 | static tree | |
5617 | lookup_placeholder (const constexpr_ctx *ctx, bool lval, tree type) | |
5618 | { | |
fbd603c4 | 5619 | if (!ctx) |
89262ec6 JM |
5620 | return NULL_TREE; |
5621 | ||
49a86fce PP |
5622 | /* Prefer the outermost matching object, but don't cross |
5623 | CONSTRUCTOR_PLACEHOLDER_BOUNDARY constructors. */ | |
5624 | if (ctx->ctor && !CONSTRUCTOR_PLACEHOLDER_BOUNDARY (ctx->ctor)) | |
5625 | if (tree outer_ob = lookup_placeholder (ctx->parent, lval, type)) | |
5626 | return outer_ob; | |
5627 | ||
89262ec6 JM |
5628 | /* We could use ctx->object unconditionally, but using ctx->ctor when we |
5629 | can is a minor optimization. */ | |
fbd603c4 | 5630 | if (!lval && ctx->ctor && same_type_p (TREE_TYPE (ctx->ctor), type)) |
89262ec6 JM |
5631 | return ctx->ctor; |
5632 | ||
fbd603c4 JM |
5633 | if (!ctx->object) |
5634 | return NULL_TREE; | |
5635 | ||
89262ec6 JM |
5636 | /* Since an object cannot have a field of its own type, we can search outward |
5637 | from ctx->object to find the unique containing object of TYPE. */ | |
5638 | tree ob = ctx->object; | |
5639 | while (ob) | |
5640 | { | |
5641 | if (same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (ob), type)) | |
5642 | break; | |
5643 | if (handled_component_p (ob)) | |
5644 | ob = TREE_OPERAND (ob, 0); | |
5645 | else | |
5646 | ob = NULL_TREE; | |
5647 | } | |
5648 | ||
5649 | return ob; | |
5650 | } | |
5651 | ||
7c814975 MP |
5652 | /* Complain about an attempt to evaluate inline assembly. */ |
5653 | ||
5654 | static void | |
5655 | inline_asm_in_constexpr_error (location_t loc) | |
5656 | { | |
5657 | auto_diagnostic_group d; | |
5658 | error_at (loc, "inline assembly is not a constant expression"); | |
5659 | inform (loc, "only unevaluated inline assembly is allowed in a " | |
b04445d4 | 5660 | "%<constexpr%> function in C++20"); |
7c814975 MP |
5661 | } |
5662 | ||
2d76680f PC |
5663 | /* Attempt to reduce the expression T to a constant value. |
5664 | On failure, issue diagnostic and return error_mark_node. */ | |
5665 | /* FIXME unify with c_fully_fold */ | |
60813a46 | 5666 | /* FIXME overflow_p is too global */ |
2d76680f PC |
5667 | |
5668 | static tree | |
3e605b20 | 5669 | cxx_eval_constant_expression (const constexpr_ctx *ctx, tree t, |
92a596e8 | 5670 | bool lval, |
56632b27 | 5671 | bool *non_constant_p, bool *overflow_p, |
3075affd | 5672 | tree *jump_target /* = NULL */) |
2d76680f | 5673 | { |
4b390698 JJ |
5674 | if (jump_target && *jump_target) |
5675 | { | |
5676 | /* If we are jumping, ignore all statements/expressions except those | |
5677 | that could have LABEL_EXPR or CASE_LABEL_EXPR in their bodies. */ | |
5678 | switch (TREE_CODE (t)) | |
5679 | { | |
5680 | case BIND_EXPR: | |
5681 | case STATEMENT_LIST: | |
5682 | case LOOP_EXPR: | |
5683 | case COND_EXPR: | |
43574e4f JJ |
5684 | case IF_STMT: |
5685 | case DO_STMT: | |
5686 | case WHILE_STMT: | |
5687 | case FOR_STMT: | |
4b390698 JJ |
5688 | break; |
5689 | case LABEL_EXPR: | |
5690 | case CASE_LABEL_EXPR: | |
5691 | if (label_matches (ctx, jump_target, t)) | |
5692 | /* Found it. */ | |
5693 | *jump_target = NULL_TREE; | |
5694 | return NULL_TREE; | |
5695 | default: | |
5696 | return NULL_TREE; | |
5697 | } | |
5698 | } | |
3075affd | 5699 | if (error_operand_p (t)) |
2d76680f PC |
5700 | { |
5701 | *non_constant_p = true; | |
5702 | return t; | |
5703 | } | |
7a649ef5 | 5704 | |
6821245b JM |
5705 | location_t loc = cp_expr_loc_or_input_loc (t); |
5706 | ||
7a649ef5 JM |
5707 | STRIP_ANY_LOCATION_WRAPPER (t); |
5708 | ||
2d76680f PC |
5709 | if (CONSTANT_CLASS_P (t)) |
5710 | { | |
61637db3 JJ |
5711 | if (TREE_OVERFLOW (t)) |
5712 | { | |
5713 | if (!ctx->quiet) | |
5714 | permerror (input_location, "overflow in constant expression"); | |
5715 | if (!flag_permissive || ctx->quiet) | |
5716 | *overflow_p = true; | |
5717 | } | |
8bada5cd MS |
5718 | |
5719 | if (TREE_CODE (t) == INTEGER_CST | |
9f613f06 | 5720 | && TYPE_PTR_P (TREE_TYPE (t)) |
8bada5cd MS |
5721 | && !integer_zerop (t)) |
5722 | { | |
5723 | if (!ctx->quiet) | |
5724 | error ("value %qE of type %qT is not a constant expression", | |
5725 | t, TREE_TYPE (t)); | |
5726 | *non_constant_p = true; | |
5727 | } | |
5728 | ||
2d76680f PC |
5729 | return t; |
5730 | } | |
2d76680f | 5731 | |
a15ffa22 | 5732 | /* Avoid excessively long constexpr evaluations. */ |
8e007055 | 5733 | if (++ctx->global->constexpr_ops_count >= constexpr_ops_limit) |
a15ffa22 JJ |
5734 | { |
5735 | if (!ctx->quiet) | |
6821245b | 5736 | error_at (loc, |
a15ffa22 | 5737 | "%<constexpr%> evaluation operation count exceeds limit of " |
a9c697b8 | 5738 | "%wd (use %<-fconstexpr-ops-limit=%> to increase the limit)", |
a15ffa22 | 5739 | constexpr_ops_limit); |
8e007055 | 5740 | ctx->global->constexpr_ops_count = INTTYPE_MINIMUM (HOST_WIDE_INT); |
a15ffa22 JJ |
5741 | *non_constant_p = true; |
5742 | return t; | |
5743 | } | |
5744 | ||
7a649ef5 JM |
5745 | constexpr_ctx new_ctx; |
5746 | tree r = t; | |
5747 | ||
8bada5cd MS |
5748 | tree_code tcode = TREE_CODE (t); |
5749 | switch (tcode) | |
2d76680f | 5750 | { |
60813a46 | 5751 | case RESULT_DECL: |
92a596e8 | 5752 | if (lval) |
60813a46 JM |
5753 | return t; |
5754 | /* We ask for an rvalue for the RESULT_DECL when indirecting | |
bf66b9b4 AH |
5755 | through an invisible reference, or in named return value |
5756 | optimization. */ | |
8e007055 | 5757 | if (tree *p = ctx->global->values.get (t)) |
1efb1dc2 MP |
5758 | return *p; |
5759 | else | |
5760 | { | |
5761 | if (!ctx->quiet) | |
5762 | error ("%qE is not a constant expression", t); | |
5763 | *non_constant_p = true; | |
5764 | } | |
5765 | break; | |
60813a46 | 5766 | |
2d76680f | 5767 | case VAR_DECL: |
70f40fea | 5768 | if (DECL_HAS_VALUE_EXPR_P (t)) |
c59fa7ea JM |
5769 | { |
5770 | if (is_normal_capture_proxy (t) | |
5771 | && current_function_decl == DECL_CONTEXT (t)) | |
5772 | { | |
5773 | /* Function parms aren't constexpr within the function | |
5774 | definition, so don't try to look at the closure. But if the | |
5775 | captured variable is constant, try to evaluate it directly. */ | |
5776 | r = DECL_CAPTURED_VARIABLE (t); | |
5777 | tree type = TREE_TYPE (t); | |
5778 | if (TYPE_REF_P (type) != TYPE_REF_P (TREE_TYPE (r))) | |
5779 | { | |
5780 | /* Adjust r to match the reference-ness of t. */ | |
5781 | if (TYPE_REF_P (type)) | |
5782 | r = build_address (r); | |
5783 | else | |
5784 | r = convert_from_reference (r); | |
5785 | } | |
5786 | } | |
5787 | else | |
5788 | r = DECL_VALUE_EXPR (t); | |
5789 | return cxx_eval_constant_expression (ctx, r, lval, non_constant_p, | |
5790 | overflow_p); | |
5791 | } | |
191816a3 | 5792 | /* fall through */ |
7c83622c JM |
5793 | case CONST_DECL: |
5794 | /* We used to not check lval for CONST_DECL, but darwin.c uses | |
5795 | CONST_DECL for aggregate constants. */ | |
92a596e8 | 5796 | if (lval) |
2d76680f | 5797 | return t; |
ef529765 JM |
5798 | else if (t == ctx->object) |
5799 | return ctx->ctor; | |
5800 | if (VAR_P (t)) | |
5801 | if (tree *p = ctx->global->values.get (t)) | |
5802 | if (*p != NULL_TREE) | |
5803 | { | |
5804 | r = *p; | |
5805 | break; | |
5806 | } | |
f4fce183 | 5807 | if (COMPLETE_TYPE_P (TREE_TYPE (t)) |
dbcd32f8 | 5808 | && is_really_empty_class (TREE_TYPE (t), /*ignore_vptr*/false)) |
7dc2b4a2 JM |
5809 | { |
5810 | /* If the class is empty, we aren't actually loading anything. */ | |
5811 | r = build_constructor (TREE_TYPE (t), NULL); | |
5812 | TREE_CONSTANT (r) = true; | |
5813 | } | |
5814 | else if (ctx->strict) | |
8c00059c | 5815 | r = decl_really_constant_value (t, /*unshare_p=*/false); |
69eb4fde | 5816 | else |
8c00059c | 5817 | r = decl_constant_value (t, /*unshare_p=*/false); |
2d76680f PC |
5818 | if (TREE_CODE (r) == TARGET_EXPR |
5819 | && TREE_CODE (TARGET_EXPR_INITIAL (r)) == CONSTRUCTOR) | |
5820 | r = TARGET_EXPR_INITIAL (r); | |
2d76680f PC |
5821 | if (DECL_P (r)) |
5822 | { | |
2b3ab879 | 5823 | if (!ctx->quiet) |
6821245b | 5824 | non_const_var_error (loc, r); |
2d76680f PC |
5825 | *non_constant_p = true; |
5826 | } | |
5827 | break; | |
5828 | ||
96a95ac1 AO |
5829 | case DEBUG_BEGIN_STMT: |
5830 | /* ??? It might be nice to retain this information somehow, so | |
5831 | as to be able to step into a constexpr function call. */ | |
5832 | /* Fall through. */ | |
5833 | ||
2d76680f PC |
5834 | case FUNCTION_DECL: |
5835 | case TEMPLATE_DECL: | |
5836 | case LABEL_DECL: | |
56632b27 JM |
5837 | case LABEL_EXPR: |
5838 | case CASE_LABEL_EXPR: | |
4b390698 | 5839 | case PREDICT_EXPR: |
2d76680f PC |
5840 | return t; |
5841 | ||
5842 | case PARM_DECL: | |
9f613f06 | 5843 | if (lval && !TYPE_REF_P (TREE_TYPE (t))) |
60813a46 | 5844 | /* glvalue use. */; |
8e007055 | 5845 | else if (tree *p = ctx->global->values.get (r)) |
60813a46 | 5846 | r = *p; |
92a596e8 | 5847 | else if (lval) |
2d76680f | 5848 | /* Defer in case this is only used for its type. */; |
1c2f613f | 5849 | else if (COMPLETE_TYPE_P (TREE_TYPE (t)) |
dbcd32f8 | 5850 | && is_really_empty_class (TREE_TYPE (t), /*ignore_vptr*/false)) |
052beba4 JM |
5851 | { |
5852 | /* If the class is empty, we aren't actually loading anything. */ | |
5853 | r = build_constructor (TREE_TYPE (t), NULL); | |
5854 | TREE_CONSTANT (r) = true; | |
5855 | } | |
2d76680f PC |
5856 | else |
5857 | { | |
2b3ab879 | 5858 | if (!ctx->quiet) |
2d76680f PC |
5859 | error ("%qE is not a constant expression", t); |
5860 | *non_constant_p = true; | |
5861 | } | |
5862 | break; | |
5863 | ||
5864 | case CALL_EXPR: | |
5865 | case AGGR_INIT_EXPR: | |
92a596e8 | 5866 | r = cxx_eval_call_expression (ctx, t, lval, |
2d76680f PC |
5867 | non_constant_p, overflow_p); |
5868 | break; | |
5869 | ||
60813a46 JM |
5870 | case DECL_EXPR: |
5871 | { | |
5872 | r = DECL_EXPR_DECL (t); | |
43574e4f JJ |
5873 | if (TREE_CODE (r) == USING_DECL) |
5874 | { | |
5875 | r = void_node; | |
5876 | break; | |
5877 | } | |
60813a46 JM |
5878 | if (AGGREGATE_TYPE_P (TREE_TYPE (r)) |
5879 | || VECTOR_TYPE_P (TREE_TYPE (r))) | |
5880 | { | |
5881 | new_ctx = *ctx; | |
5882 | new_ctx.object = r; | |
5883 | new_ctx.ctor = build_constructor (TREE_TYPE (r), NULL); | |
e8c48716 | 5884 | CONSTRUCTOR_NO_CLEARING (new_ctx.ctor) = true; |
8e007055 | 5885 | ctx->global->values.put (r, new_ctx.ctor); |
60813a46 JM |
5886 | ctx = &new_ctx; |
5887 | } | |
5888 | ||
5889 | if (tree init = DECL_INITIAL (r)) | |
5890 | { | |
5891 | init = cxx_eval_constant_expression (ctx, init, | |
2b3ab879 | 5892 | false, |
5a804683 | 5893 | non_constant_p, overflow_p); |
7f0e23e9 | 5894 | /* Don't share a CONSTRUCTOR that might be changed. */ |
0146e25f | 5895 | init = unshare_constructor (init); |
04e1749c MP |
5896 | /* Remember that a constant object's constructor has already |
5897 | run. */ | |
5898 | if (CLASS_TYPE_P (TREE_TYPE (r)) | |
5899 | && CP_TYPE_CONST_P (TREE_TYPE (r))) | |
5900 | TREE_READONLY (init) = true; | |
8e007055 | 5901 | ctx->global->values.put (r, init); |
60813a46 JM |
5902 | } |
5903 | else if (ctx == &new_ctx) | |
5904 | /* We gave it a CONSTRUCTOR above. */; | |
5905 | else | |
8e007055 | 5906 | ctx->global->values.put (r, NULL_TREE); |
60813a46 JM |
5907 | } |
5908 | break; | |
5909 | ||
2d76680f | 5910 | case TARGET_EXPR: |
595f1b12 JM |
5911 | { |
5912 | tree type = TREE_TYPE (t); | |
5913 | ||
5914 | if (!literal_type_p (type)) | |
5915 | { | |
5916 | if (!ctx->quiet) | |
5917 | { | |
5918 | auto_diagnostic_group d; | |
5919 | error ("temporary of non-literal type %qT in a " | |
5920 | "constant expression", type); | |
5921 | explain_non_literal_class (type); | |
5922 | } | |
5923 | *non_constant_p = true; | |
5924 | break; | |
5925 | } | |
5926 | gcc_checking_assert (!TARGET_EXPR_DIRECT_INIT_P (t)); | |
5927 | /* Avoid evaluating a TARGET_EXPR more than once. */ | |
5928 | tree slot = TARGET_EXPR_SLOT (t); | |
5929 | if (tree *p = ctx->global->values.get (slot)) | |
5930 | { | |
5931 | if (lval) | |
5932 | return slot; | |
5933 | r = *p; | |
5934 | break; | |
5935 | } | |
595f1b12 JM |
5936 | if ((AGGREGATE_TYPE_P (type) || VECTOR_TYPE_P (type))) |
5937 | { | |
5938 | /* We're being expanded without an explicit target, so start | |
5939 | initializing a new object; expansion with an explicit target | |
5940 | strips the TARGET_EXPR before we get here. */ | |
5941 | new_ctx = *ctx; | |
49a86fce PP |
5942 | /* Link CTX to NEW_CTX so that lookup_placeholder can resolve |
5943 | any PLACEHOLDER_EXPR within the initializer that refers to the | |
5944 | former object under construction. */ | |
5945 | new_ctx.parent = ctx; | |
595f1b12 JM |
5946 | new_ctx.ctor = build_constructor (type, NULL); |
5947 | CONSTRUCTOR_NO_CLEARING (new_ctx.ctor) = true; | |
5948 | new_ctx.object = slot; | |
5949 | ctx->global->values.put (new_ctx.object, new_ctx.ctor); | |
5950 | ctx = &new_ctx; | |
5951 | } | |
5952 | /* Pass false for 'lval' because this indicates | |
5953 | initialization of a temporary. */ | |
5954 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), | |
5955 | false, | |
5956 | non_constant_p, overflow_p); | |
5957 | if (*non_constant_p) | |
ee1de08d | 5958 | break; |
595f1b12 JM |
5959 | /* Adjust the type of the result to the type of the temporary. */ |
5960 | r = adjust_temp_type (type, r); | |
5961 | if (TARGET_EXPR_CLEANUP (t) && !CLEANUP_EH_ONLY (t)) | |
5962 | ctx->global->cleanups->safe_push (TARGET_EXPR_CLEANUP (t)); | |
5963 | r = unshare_constructor (r); | |
5964 | ctx->global->values.put (slot, r); | |
5965 | if (ctx->save_exprs) | |
5966 | ctx->save_exprs->safe_push (slot); | |
5967 | if (lval) | |
5968 | return slot; | |
5969 | } | |
2d76680f PC |
5970 | break; |
5971 | ||
60813a46 | 5972 | case INIT_EXPR: |
60813a46 | 5973 | case MODIFY_EXPR: |
4b390698 | 5974 | gcc_assert (jump_target == NULL || *jump_target == NULL_TREE); |
92a596e8 | 5975 | r = cxx_eval_store_expression (ctx, t, lval, |
60813a46 JM |
5976 | non_constant_p, overflow_p); |
5977 | break; | |
5978 | ||
2d76680f | 5979 | case SCOPE_REF: |
3e605b20 | 5980 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), |
92a596e8 | 5981 | lval, |
5a804683 | 5982 | non_constant_p, overflow_p); |
2d76680f PC |
5983 | break; |
5984 | ||
5985 | case RETURN_EXPR: | |
75e0295b MP |
5986 | if (TREE_OPERAND (t, 0) != NULL_TREE) |
5987 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), | |
5988 | lval, | |
5989 | non_constant_p, overflow_p); | |
43574e4f JJ |
5990 | /* FALLTHRU */ |
5991 | case BREAK_STMT: | |
5992 | case CONTINUE_STMT: | |
019e0ae8 MP |
5993 | if (jump_target) |
5994 | *jump_target = t; | |
5995 | else | |
5996 | { | |
5997 | /* Can happen with ({ return true; }) && false; passed to | |
5998 | maybe_constant_value. There is nothing to jump over in this | |
5999 | case, and the bug will be diagnosed later. */ | |
6000 | gcc_assert (ctx->quiet); | |
6001 | *non_constant_p = true; | |
6002 | } | |
56632b27 JM |
6003 | break; |
6004 | ||
cabaf50a JM |
6005 | case SAVE_EXPR: |
6006 | /* Avoid evaluating a SAVE_EXPR more than once. */ | |
8e007055 | 6007 | if (tree *p = ctx->global->values.get (t)) |
cabaf50a JM |
6008 | r = *p; |
6009 | else | |
6010 | { | |
12d9ce19 | 6011 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), false, |
cabaf50a | 6012 | non_constant_p, overflow_p); |
0e0ffbfc JJ |
6013 | if (*non_constant_p) |
6014 | break; | |
8e007055 | 6015 | ctx->global->values.put (t, r); |
39dce2b7 | 6016 | if (ctx->save_exprs) |
0ee28590 | 6017 | ctx->save_exprs->safe_push (t); |
cabaf50a JM |
6018 | } |
6019 | break; | |
6020 | ||
2d76680f | 6021 | case TRY_CATCH_EXPR: |
ee1de08d JJ |
6022 | if (TREE_OPERAND (t, 0) == NULL_TREE) |
6023 | { | |
6024 | r = void_node; | |
6025 | break; | |
6026 | } | |
6027 | /* FALLTHRU */ | |
6028 | case NON_LVALUE_EXPR: | |
769430b2 | 6029 | case TRY_BLOCK: |
2d76680f | 6030 | case MUST_NOT_THROW_EXPR: |
60813a46 JM |
6031 | case EXPR_STMT: |
6032 | case EH_SPEC_BLOCK: | |
3e605b20 | 6033 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), |
92a596e8 | 6034 | lval, |
56632b27 JM |
6035 | non_constant_p, overflow_p, |
6036 | jump_target); | |
2d76680f PC |
6037 | break; |
6038 | ||
ee1de08d JJ |
6039 | case CLEANUP_POINT_EXPR: |
6040 | { | |
6041 | auto_vec<tree, 2> cleanups; | |
6042 | vec<tree> *prev_cleanups = ctx->global->cleanups; | |
6043 | ctx->global->cleanups = &cleanups; | |
6044 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), | |
6045 | lval, | |
6046 | non_constant_p, overflow_p, | |
6047 | jump_target); | |
6048 | ctx->global->cleanups = prev_cleanups; | |
6049 | unsigned int i; | |
6050 | tree cleanup; | |
6051 | /* Evaluate the cleanups. */ | |
6052 | FOR_EACH_VEC_ELT_REVERSE (cleanups, i, cleanup) | |
6053 | cxx_eval_constant_expression (ctx, cleanup, false, | |
fc531c2e | 6054 | non_constant_p, overflow_p); |
ee1de08d JJ |
6055 | } |
6056 | break; | |
6057 | ||
769430b2 JM |
6058 | case TRY_FINALLY_EXPR: |
6059 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval, | |
6060 | non_constant_p, overflow_p, | |
6061 | jump_target); | |
6062 | if (!*non_constant_p) | |
6063 | /* Also evaluate the cleanup. */ | |
6064 | cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), true, | |
fc531c2e | 6065 | non_constant_p, overflow_p); |
769430b2 JM |
6066 | break; |
6067 | ||
43574e4f | 6068 | case CLEANUP_STMT: |
fc531c2e JJ |
6069 | r = cxx_eval_constant_expression (ctx, CLEANUP_BODY (t), lval, |
6070 | non_constant_p, overflow_p, | |
6071 | jump_target); | |
6072 | if (!CLEANUP_EH_ONLY (t) && !*non_constant_p) | |
6073 | { | |
6074 | iloc_sentinel ils (loc); | |
6075 | /* Also evaluate the cleanup. */ | |
6076 | cxx_eval_constant_expression (ctx, CLEANUP_EXPR (t), true, | |
6077 | non_constant_p, overflow_p); | |
6078 | } | |
43574e4f JJ |
6079 | break; |
6080 | ||
2d76680f PC |
6081 | /* These differ from cxx_eval_unary_expression in that this doesn't |
6082 | check for a constant operand or result; an address can be | |
6083 | constant without its operand being, and vice versa. */ | |
cda0a029 | 6084 | case MEM_REF: |
2d76680f | 6085 | case INDIRECT_REF: |
92a596e8 | 6086 | r = cxx_eval_indirect_ref (ctx, t, lval, |
2d76680f PC |
6087 | non_constant_p, overflow_p); |
6088 | break; | |
6089 | ||
6090 | case ADDR_EXPR: | |
6091 | { | |
6092 | tree oldop = TREE_OPERAND (t, 0); | |
3e605b20 | 6093 | tree op = cxx_eval_constant_expression (ctx, oldop, |
92a596e8 | 6094 | /*lval*/true, |
5a804683 | 6095 | non_constant_p, overflow_p); |
2d76680f PC |
6096 | /* Don't VERIFY_CONSTANT here. */ |
6097 | if (*non_constant_p) | |
6098 | return t; | |
f2acb8ad | 6099 | gcc_checking_assert (TREE_CODE (op) != CONSTRUCTOR); |
2d76680f PC |
6100 | /* This function does more aggressive folding than fold itself. */ |
6101 | r = build_fold_addr_expr_with_type (op, TREE_TYPE (t)); | |
6102 | if (TREE_CODE (r) == ADDR_EXPR && TREE_OPERAND (r, 0) == oldop) | |
7a649ef5 JM |
6103 | { |
6104 | ggc_free (r); | |
6105 | return t; | |
6106 | } | |
2d76680f PC |
6107 | break; |
6108 | } | |
6109 | ||
6110 | case REALPART_EXPR: | |
6111 | case IMAGPART_EXPR: | |
87713c6a JJ |
6112 | if (lval) |
6113 | { | |
6114 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval, | |
6115 | non_constant_p, overflow_p); | |
6116 | if (r == error_mark_node) | |
6117 | ; | |
6118 | else if (r == TREE_OPERAND (t, 0)) | |
6119 | r = t; | |
6120 | else | |
6121 | r = fold_build1 (TREE_CODE (t), TREE_TYPE (t), r); | |
6122 | break; | |
6123 | } | |
6124 | /* FALLTHRU */ | |
2d76680f PC |
6125 | case CONJ_EXPR: |
6126 | case FIX_TRUNC_EXPR: | |
6127 | case FLOAT_EXPR: | |
6128 | case NEGATE_EXPR: | |
6129 | case ABS_EXPR: | |
e28fadbc | 6130 | case ABSU_EXPR: |
2d76680f PC |
6131 | case BIT_NOT_EXPR: |
6132 | case TRUTH_NOT_EXPR: | |
6133 | case FIXED_CONVERT_EXPR: | |
92a596e8 | 6134 | r = cxx_eval_unary_expression (ctx, t, lval, |
2d76680f PC |
6135 | non_constant_p, overflow_p); |
6136 | break; | |
6137 | ||
6138 | case SIZEOF_EXPR: | |
99e764a2 MP |
6139 | r = fold_sizeof_expr (t); |
6140 | /* In a template, fold_sizeof_expr may merely create a new SIZEOF_EXPR, | |
6141 | which could lead to an infinite recursion. */ | |
6142 | if (TREE_CODE (r) != SIZEOF_EXPR) | |
6143 | r = cxx_eval_constant_expression (ctx, r, lval, | |
6144 | non_constant_p, overflow_p, | |
6145 | jump_target); | |
6146 | else | |
6147 | { | |
6148 | *non_constant_p = true; | |
6149 | gcc_assert (ctx->quiet); | |
6150 | } | |
6151 | ||
2d76680f PC |
6152 | break; |
6153 | ||
6154 | case COMPOUND_EXPR: | |
6155 | { | |
6156 | /* check_return_expr sometimes wraps a TARGET_EXPR in a | |
6157 | COMPOUND_EXPR; don't get confused. Also handle EMPTY_CLASS_EXPR | |
6158 | introduced by build_call_a. */ | |
6159 | tree op0 = TREE_OPERAND (t, 0); | |
6160 | tree op1 = TREE_OPERAND (t, 1); | |
6161 | STRIP_NOPS (op1); | |
6162 | if ((TREE_CODE (op0) == TARGET_EXPR && op1 == TARGET_EXPR_SLOT (op0)) | |
6163 | || TREE_CODE (op1) == EMPTY_CLASS_EXPR) | |
2b3ab879 | 6164 | r = cxx_eval_constant_expression (ctx, op0, |
92a596e8 | 6165 | lval, non_constant_p, overflow_p, |
56632b27 | 6166 | jump_target); |
2d76680f PC |
6167 | else |
6168 | { | |
6169 | /* Check that the LHS is constant and then discard it. */ | |
2b3ab879 | 6170 | cxx_eval_constant_expression (ctx, op0, |
12d9ce19 | 6171 | true, non_constant_p, overflow_p, |
56632b27 | 6172 | jump_target); |
06ec22b7 JM |
6173 | if (*non_constant_p) |
6174 | return t; | |
2d76680f | 6175 | op1 = TREE_OPERAND (t, 1); |
2b3ab879 | 6176 | r = cxx_eval_constant_expression (ctx, op1, |
92a596e8 | 6177 | lval, non_constant_p, overflow_p, |
56632b27 | 6178 | jump_target); |
2d76680f PC |
6179 | } |
6180 | } | |
6181 | break; | |
6182 | ||
6183 | case POINTER_PLUS_EXPR: | |
1af4ebf5 | 6184 | case POINTER_DIFF_EXPR: |
2d76680f PC |
6185 | case PLUS_EXPR: |
6186 | case MINUS_EXPR: | |
6187 | case MULT_EXPR: | |
6188 | case TRUNC_DIV_EXPR: | |
6189 | case CEIL_DIV_EXPR: | |
6190 | case FLOOR_DIV_EXPR: | |
6191 | case ROUND_DIV_EXPR: | |
6192 | case TRUNC_MOD_EXPR: | |
6193 | case CEIL_MOD_EXPR: | |
6194 | case ROUND_MOD_EXPR: | |
6195 | case RDIV_EXPR: | |
6196 | case EXACT_DIV_EXPR: | |
6197 | case MIN_EXPR: | |
6198 | case MAX_EXPR: | |
6199 | case LSHIFT_EXPR: | |
6200 | case RSHIFT_EXPR: | |
81fa6d73 JJ |
6201 | case LROTATE_EXPR: |
6202 | case RROTATE_EXPR: | |
2d76680f PC |
6203 | case BIT_IOR_EXPR: |
6204 | case BIT_XOR_EXPR: | |
6205 | case BIT_AND_EXPR: | |
6206 | case TRUTH_XOR_EXPR: | |
6207 | case LT_EXPR: | |
6208 | case LE_EXPR: | |
6209 | case GT_EXPR: | |
6210 | case GE_EXPR: | |
6211 | case EQ_EXPR: | |
6212 | case NE_EXPR: | |
b7689b96 | 6213 | case SPACESHIP_EXPR: |
2d76680f PC |
6214 | case UNORDERED_EXPR: |
6215 | case ORDERED_EXPR: | |
6216 | case UNLT_EXPR: | |
6217 | case UNLE_EXPR: | |
6218 | case UNGT_EXPR: | |
6219 | case UNGE_EXPR: | |
6220 | case UNEQ_EXPR: | |
6221 | case LTGT_EXPR: | |
6222 | case RANGE_EXPR: | |
6223 | case COMPLEX_EXPR: | |
92a596e8 | 6224 | r = cxx_eval_binary_expression (ctx, t, lval, |
2d76680f PC |
6225 | non_constant_p, overflow_p); |
6226 | break; | |
6227 | ||
6228 | /* fold can introduce non-IF versions of these; still treat them as | |
6229 | short-circuiting. */ | |
6230 | case TRUTH_AND_EXPR: | |
6231 | case TRUTH_ANDIF_EXPR: | |
3e605b20 | 6232 | r = cxx_eval_logical_expression (ctx, t, boolean_false_node, |
2d76680f | 6233 | boolean_true_node, |
92a596e8 | 6234 | lval, |
2d76680f PC |
6235 | non_constant_p, overflow_p); |
6236 | break; | |
6237 | ||
6238 | case TRUTH_OR_EXPR: | |
6239 | case TRUTH_ORIF_EXPR: | |
3e605b20 | 6240 | r = cxx_eval_logical_expression (ctx, t, boolean_true_node, |
2d76680f | 6241 | boolean_false_node, |
92a596e8 | 6242 | lval, |
2d76680f PC |
6243 | non_constant_p, overflow_p); |
6244 | break; | |
6245 | ||
6246 | case ARRAY_REF: | |
92a596e8 | 6247 | r = cxx_eval_array_reference (ctx, t, lval, |
2d76680f PC |
6248 | non_constant_p, overflow_p); |
6249 | break; | |
6250 | ||
6251 | case COMPONENT_REF: | |
6252 | if (is_overloaded_fn (t)) | |
6253 | { | |
6254 | /* We can only get here in checking mode via | |
6255 | build_non_dependent_expr, because any expression that | |
6256 | calls or takes the address of the function will have | |
6257 | pulled a FUNCTION_DECL out of the COMPONENT_REF. */ | |
2b3ab879 | 6258 | gcc_checking_assert (ctx->quiet || errorcount); |
2d76680f PC |
6259 | *non_constant_p = true; |
6260 | return t; | |
6261 | } | |
92a596e8 | 6262 | r = cxx_eval_component_reference (ctx, t, lval, |
2d76680f PC |
6263 | non_constant_p, overflow_p); |
6264 | break; | |
6265 | ||
6266 | case BIT_FIELD_REF: | |
92a596e8 | 6267 | r = cxx_eval_bit_field_ref (ctx, t, lval, |
2d76680f PC |
6268 | non_constant_p, overflow_p); |
6269 | break; | |
6270 | ||
6271 | case COND_EXPR: | |
43574e4f | 6272 | case IF_STMT: |
4b390698 JJ |
6273 | if (jump_target && *jump_target) |
6274 | { | |
e9fa2f6d | 6275 | tree orig_jump = *jump_target; |
43574e4f JJ |
6276 | tree arg = ((TREE_CODE (t) != IF_STMT || TREE_OPERAND (t, 1)) |
6277 | ? TREE_OPERAND (t, 1) : void_node); | |
4b390698 JJ |
6278 | /* When jumping to a label, the label might be either in the |
6279 | then or else blocks, so process then block first in skipping | |
6280 | mode first, and if we are still in the skipping mode at its end, | |
6281 | process the else block too. */ | |
43574e4f JJ |
6282 | r = cxx_eval_constant_expression (ctx, arg, lval, non_constant_p, |
6283 | overflow_p, jump_target); | |
e9fa2f6d MP |
6284 | /* It's possible that we found the label in the then block. But |
6285 | it could have been followed by another jumping statement, e.g. | |
6286 | say we're looking for case 1: | |
6287 | if (cond) | |
6288 | { | |
6289 | // skipped statements | |
6290 | case 1:; // clears up *jump_target | |
6291 | return 1; // and sets it to a RETURN_EXPR | |
6292 | } | |
6293 | else { ... } | |
6294 | in which case we need not go looking to the else block. | |
6295 | (goto is not allowed in a constexpr function.) */ | |
6296 | if (*jump_target == orig_jump) | |
43574e4f JJ |
6297 | { |
6298 | arg = ((TREE_CODE (t) != IF_STMT || TREE_OPERAND (t, 2)) | |
6299 | ? TREE_OPERAND (t, 2) : void_node); | |
6300 | r = cxx_eval_constant_expression (ctx, arg, lval, non_constant_p, | |
6301 | overflow_p, jump_target); | |
6302 | } | |
4b390698 JJ |
6303 | break; |
6304 | } | |
92a596e8 | 6305 | r = cxx_eval_conditional_expression (ctx, t, lval, |
56632b27 JM |
6306 | non_constant_p, overflow_p, |
6307 | jump_target); | |
2d76680f | 6308 | break; |
f370e36d JJ |
6309 | case VEC_COND_EXPR: |
6310 | r = cxx_eval_vector_conditional_expression (ctx, t, non_constant_p, | |
6311 | overflow_p); | |
6312 | break; | |
2d76680f PC |
6313 | |
6314 | case CONSTRUCTOR: | |
35d87f01 | 6315 | if (TREE_CONSTANT (t) && reduced_constant_expression_p (t)) |
2d63bc39 JM |
6316 | { |
6317 | /* Don't re-process a constant CONSTRUCTOR, but do fold it to | |
6318 | VECTOR_CST if applicable. */ | |
ac9ec198 | 6319 | verify_constructor_flags (t); |
2d63bc39 JM |
6320 | if (TREE_CONSTANT (t)) |
6321 | return fold (t); | |
6322 | } | |
92a596e8 | 6323 | r = cxx_eval_bare_aggregate (ctx, t, lval, |
2d76680f PC |
6324 | non_constant_p, overflow_p); |
6325 | break; | |
6326 | ||
6327 | case VEC_INIT_EXPR: | |
6328 | /* We can get this in a defaulted constructor for a class with a | |
6329 | non-static data member of array type. Either the initializer will | |
6330 | be NULL, meaning default-initialization, or it will be an lvalue | |
6331 | or xvalue of the same type, meaning direct-initialization from the | |
6332 | corresponding member. */ | |
92a596e8 | 6333 | r = cxx_eval_vec_init (ctx, t, lval, |
2d76680f PC |
6334 | non_constant_p, overflow_p); |
6335 | break; | |
6336 | ||
2d76680f | 6337 | case VEC_PERM_EXPR: |
92a596e8 | 6338 | r = cxx_eval_trinary_expression (ctx, t, lval, |
2d76680f PC |
6339 | non_constant_p, overflow_p); |
6340 | break; | |
6341 | ||
7d75ea04 JJ |
6342 | case NOP_EXPR: |
6343 | if (REINTERPRET_CAST_P (t)) | |
6344 | { | |
6345 | if (!ctx->quiet) | |
6821245b | 6346 | error_at (loc, |
a9c697b8 | 6347 | "%<reinterpret_cast%> is not a constant expression"); |
7d75ea04 JJ |
6348 | *non_constant_p = true; |
6349 | return t; | |
6350 | } | |
6351 | /* FALLTHROUGH. */ | |
2d76680f PC |
6352 | case CONVERT_EXPR: |
6353 | case VIEW_CONVERT_EXPR: | |
cda0a029 | 6354 | case UNARY_PLUS_EXPR: |
2d76680f PC |
6355 | { |
6356 | tree oldop = TREE_OPERAND (t, 0); | |
cda0a029 | 6357 | |
3e605b20 | 6358 | tree op = cxx_eval_constant_expression (ctx, oldop, |
92a596e8 | 6359 | lval, |
5a804683 | 6360 | non_constant_p, overflow_p); |
2d76680f PC |
6361 | if (*non_constant_p) |
6362 | return t; | |
dcdbc004 | 6363 | tree type = TREE_TYPE (t); |
02a8575c JM |
6364 | |
6365 | if (VOID_TYPE_P (type)) | |
6366 | return void_node; | |
6367 | ||
eeb54a14 JJ |
6368 | if (TREE_CODE (t) == CONVERT_EXPR |
6369 | && ARITHMETIC_TYPE_P (type) | |
6370 | && INDIRECT_TYPE_P (TREE_TYPE (op))) | |
6371 | { | |
6372 | if (!ctx->quiet) | |
6373 | error_at (loc, | |
6374 | "conversion from pointer type %qT to arithmetic type " | |
6375 | "%qT in a constant expression", TREE_TYPE (op), type); | |
6376 | *non_constant_p = true; | |
6377 | return t; | |
6378 | } | |
6379 | ||
8e007055 | 6380 | if (TREE_CODE (op) == PTRMEM_CST && !TYPE_PTRMEM_P (type)) |
dcdbc004 | 6381 | op = cplus_expand_constant (op); |
7d75ea04 | 6382 | |
05bf54c3 MP |
6383 | if (TREE_CODE (op) == PTRMEM_CST && tcode == NOP_EXPR) |
6384 | { | |
7d75ea04 JJ |
6385 | if (!same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (op)) |
6386 | && !can_convert_qual (type, op)) | |
6387 | op = cplus_expand_constant (op); | |
6388 | return cp_fold_convert (type, op); | |
05bf54c3 | 6389 | } |
8bada5cd | 6390 | |
71a93b08 | 6391 | if (INDIRECT_TYPE_P (type) && TREE_CODE (op) == INTEGER_CST) |
2d76680f | 6392 | { |
8bada5cd MS |
6393 | if (integer_zerop (op)) |
6394 | { | |
9f613f06 | 6395 | if (TYPE_REF_P (type)) |
8bada5cd MS |
6396 | { |
6397 | if (!ctx->quiet) | |
6821245b | 6398 | error_at (loc, |
8bada5cd MS |
6399 | "dereferencing a null pointer"); |
6400 | *non_constant_p = true; | |
6401 | return t; | |
6402 | } | |
9f613f06 | 6403 | else if (TYPE_PTR_P (TREE_TYPE (op))) |
8bada5cd MS |
6404 | { |
6405 | tree from = TREE_TYPE (op); | |
6406 | ||
6407 | if (!can_convert (type, from, tf_none)) | |
6408 | { | |
6409 | if (!ctx->quiet) | |
6821245b | 6410 | error_at (loc, |
8bada5cd MS |
6411 | "conversion of %qT null pointer to %qT " |
6412 | "is not a constant expression", | |
6413 | from, type); | |
6414 | *non_constant_p = true; | |
6415 | return t; | |
6416 | } | |
6417 | } | |
6418 | } | |
6419 | else | |
6420 | { | |
6421 | /* This detects for example: | |
6422 | reinterpret_cast<void*>(sizeof 0) | |
6423 | */ | |
6424 | if (!ctx->quiet) | |
6821245b | 6425 | error_at (loc, "%<reinterpret_cast<%T>(%E)%> is not " |
64d6d399 | 6426 | "a constant expression", |
8bada5cd MS |
6427 | type, op); |
6428 | *non_constant_p = true; | |
6429 | return t; | |
6430 | } | |
2d76680f | 6431 | } |
7d75ea04 | 6432 | |
8e007055 JJ |
6433 | if (INDIRECT_TYPE_P (type) |
6434 | && TREE_CODE (op) == NOP_EXPR | |
6435 | && TREE_TYPE (op) == ptr_type_node | |
6436 | && TREE_CODE (TREE_OPERAND (op, 0)) == ADDR_EXPR | |
6437 | && VAR_P (TREE_OPERAND (TREE_OPERAND (op, 0), 0)) | |
815baade JJ |
6438 | && (DECL_NAME (TREE_OPERAND (TREE_OPERAND (op, 0), |
6439 | 0)) == heap_uninit_identifier | |
6440 | || DECL_NAME (TREE_OPERAND (TREE_OPERAND (op, 0), | |
6441 | 0)) == heap_vec_uninit_identifier)) | |
8e007055 JJ |
6442 | { |
6443 | tree var = TREE_OPERAND (TREE_OPERAND (op, 0), 0); | |
6444 | tree var_size = TYPE_SIZE_UNIT (TREE_TYPE (var)); | |
6445 | tree elt_type = TREE_TYPE (type); | |
6446 | tree cookie_size = NULL_TREE; | |
6447 | if (TREE_CODE (elt_type) == RECORD_TYPE | |
6448 | && TYPE_NAME (elt_type) == heap_identifier) | |
6449 | { | |
6450 | tree fld1 = TYPE_FIELDS (elt_type); | |
6451 | tree fld2 = DECL_CHAIN (fld1); | |
6452 | elt_type = TREE_TYPE (TREE_TYPE (fld2)); | |
6453 | cookie_size = TYPE_SIZE_UNIT (TREE_TYPE (fld1)); | |
6454 | } | |
815baade JJ |
6455 | DECL_NAME (var) |
6456 | = (DECL_NAME (var) == heap_uninit_identifier | |
6457 | ? heap_identifier : heap_vec_identifier); | |
8e007055 JJ |
6458 | TREE_TYPE (var) |
6459 | = build_new_constexpr_heap_type (elt_type, cookie_size, | |
6460 | var_size); | |
6461 | TREE_TYPE (TREE_OPERAND (op, 0)) | |
6462 | = build_pointer_type (TREE_TYPE (var)); | |
6463 | } | |
6464 | ||
cda0a029 | 6465 | if (op == oldop && tcode != UNARY_PLUS_EXPR) |
2d76680f PC |
6466 | /* We didn't fold at the top so we could check for ptr-int |
6467 | conversion. */ | |
6468 | return fold (t); | |
7d75ea04 | 6469 | |
02a8575c JM |
6470 | tree sop; |
6471 | ||
e4511ca2 JM |
6472 | /* Handle an array's bounds having been deduced after we built |
6473 | the wrapping expression. */ | |
6474 | if (same_type_ignoring_tlq_and_bounds_p (type, TREE_TYPE (op))) | |
6475 | r = op; | |
02a8575c JM |
6476 | else if (sop = tree_strip_nop_conversions (op), |
6477 | sop != op && (same_type_ignoring_tlq_and_bounds_p | |
6478 | (type, TREE_TYPE (sop)))) | |
6479 | r = sop; | |
e4511ca2 | 6480 | else if (tcode == UNARY_PLUS_EXPR) |
cda0a029 JM |
6481 | r = fold_convert (TREE_TYPE (t), op); |
6482 | else | |
6483 | r = fold_build1 (tcode, type, op); | |
7d75ea04 | 6484 | |
2d76680f PC |
6485 | /* Conversion of an out-of-range value has implementation-defined |
6486 | behavior; the language considers it different from arithmetic | |
6487 | overflow, which is undefined. */ | |
6488 | if (TREE_OVERFLOW_P (r) && !TREE_OVERFLOW_P (op)) | |
6489 | TREE_OVERFLOW (r) = false; | |
6490 | } | |
6491 | break; | |
6492 | ||
6493 | case EMPTY_CLASS_EXPR: | |
46fdced6 PP |
6494 | /* Handle EMPTY_CLASS_EXPR produced by build_call_a by lowering |
6495 | it to an appropriate CONSTRUCTOR. */ | |
6496 | return build_constructor (TREE_TYPE (t), NULL); | |
2d76680f | 6497 | |
60813a46 | 6498 | case STATEMENT_LIST: |
56632b27 JM |
6499 | new_ctx = *ctx; |
6500 | new_ctx.ctor = new_ctx.object = NULL_TREE; | |
2b3ab879 | 6501 | return cxx_eval_statement_list (&new_ctx, t, |
56632b27 | 6502 | non_constant_p, overflow_p, jump_target); |
60813a46 JM |
6503 | |
6504 | case BIND_EXPR: | |
6505 | return cxx_eval_constant_expression (ctx, BIND_EXPR_BODY (t), | |
92a596e8 | 6506 | lval, |
56632b27 JM |
6507 | non_constant_p, overflow_p, |
6508 | jump_target); | |
60813a46 | 6509 | |
2d76680f PC |
6510 | case PREINCREMENT_EXPR: |
6511 | case POSTINCREMENT_EXPR: | |
6512 | case PREDECREMENT_EXPR: | |
6513 | case POSTDECREMENT_EXPR: | |
2b3ab879 | 6514 | return cxx_eval_increment_expression (ctx, t, |
92a596e8 | 6515 | lval, non_constant_p, overflow_p); |
60813a46 JM |
6516 | |
6517 | case LAMBDA_EXPR: | |
2d76680f PC |
6518 | case NEW_EXPR: |
6519 | case VEC_NEW_EXPR: | |
6520 | case DELETE_EXPR: | |
6521 | case VEC_DELETE_EXPR: | |
6522 | case THROW_EXPR: | |
2d76680f PC |
6523 | case MODOP_EXPR: |
6524 | /* GCC internal stuff. */ | |
6525 | case VA_ARG_EXPR: | |
2d76680f PC |
6526 | case NON_DEPENDENT_EXPR: |
6527 | case BASELINK: | |
2d76680f | 6528 | case OFFSET_REF: |
2b3ab879 | 6529 | if (!ctx->quiet) |
6821245b | 6530 | error_at (loc, "expression %qE is not a constant expression", t); |
2d76680f PC |
6531 | *non_constant_p = true; |
6532 | break; | |
6533 | ||
bf8d8309 | 6534 | case OBJ_TYPE_REF: |
7ece3bd8 JM |
6535 | /* Virtual function lookup. We don't need to do anything fancy. */ |
6536 | return cxx_eval_constant_expression (ctx, OBJ_TYPE_REF_EXPR (t), | |
6537 | lval, non_constant_p, overflow_p); | |
bf8d8309 | 6538 | |
3e605b20 | 6539 | case PLACEHOLDER_EXPR: |
89262ec6 JM |
6540 | /* Use of the value or address of the current object. */ |
6541 | if (tree ctor = lookup_placeholder (ctx, lval, TREE_TYPE (t))) | |
b599bf9d PP |
6542 | { |
6543 | if (TREE_CODE (ctor) == CONSTRUCTOR) | |
6544 | return ctor; | |
6545 | else | |
6546 | return cxx_eval_constant_expression (ctx, ctor, lval, | |
6547 | non_constant_p, overflow_p); | |
6548 | } | |
89262ec6 JM |
6549 | /* A placeholder without a referent. We can get here when |
6550 | checking whether NSDMIs are noexcept, or in massage_init_elt; | |
6551 | just say it's non-constant for now. */ | |
6552 | gcc_assert (ctx->quiet); | |
6553 | *non_constant_p = true; | |
3e605b20 JM |
6554 | break; |
6555 | ||
06ec22b7 JM |
6556 | case EXIT_EXPR: |
6557 | { | |
6558 | tree cond = TREE_OPERAND (t, 0); | |
6559 | cond = cxx_eval_constant_expression (ctx, cond, /*lval*/false, | |
6560 | non_constant_p, overflow_p); | |
6561 | VERIFY_CONSTANT (cond); | |
6562 | if (integer_nonzerop (cond)) | |
6563 | *jump_target = t; | |
6564 | } | |
6565 | break; | |
6566 | ||
60813a46 | 6567 | case GOTO_EXPR: |
56632b27 | 6568 | *jump_target = TREE_OPERAND (t, 0); |
d49318d9 PC |
6569 | gcc_assert (breaks (jump_target) || continues (jump_target) |
6570 | /* Allow for jumping to a cdtor_label. */ | |
6571 | || returns (jump_target)); | |
56632b27 JM |
6572 | break; |
6573 | ||
60813a46 | 6574 | case LOOP_EXPR: |
43574e4f JJ |
6575 | case DO_STMT: |
6576 | case WHILE_STMT: | |
6577 | case FOR_STMT: | |
2b3ab879 | 6578 | cxx_eval_loop_expr (ctx, t, |
56632b27 JM |
6579 | non_constant_p, overflow_p, jump_target); |
6580 | break; | |
6581 | ||
60813a46 | 6582 | case SWITCH_EXPR: |
43574e4f | 6583 | case SWITCH_STMT: |
2b3ab879 | 6584 | cxx_eval_switch_expr (ctx, t, |
56632b27 | 6585 | non_constant_p, overflow_p, jump_target); |
60813a46 JM |
6586 | break; |
6587 | ||
971e17ff AS |
6588 | case REQUIRES_EXPR: |
6589 | /* It's possible to get a requires-expression in a constant | |
6590 | expression. For example: | |
6591 | ||
6592 | template<typename T> concept bool C() { | |
6593 | return requires (T t) { t; }; | |
6594 | } | |
6595 | ||
6596 | template<typename T> requires !C<T>() void f(T); | |
6597 | ||
6598 | Normalization leaves f with the associated constraint | |
6599 | '!requires (T t) { ... }' which is not transformed into | |
6600 | a constraint. */ | |
6601 | if (!processing_template_decl) | |
cb57504a | 6602 | return satisfy_constraint_expression (t); |
971e17ff AS |
6603 | else |
6604 | *non_constant_p = true; | |
6605 | return t; | |
6606 | ||
98e09245 | 6607 | case ANNOTATE_EXPR: |
98e09245 JJ |
6608 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), |
6609 | lval, | |
6610 | non_constant_p, overflow_p, | |
6611 | jump_target); | |
6612 | break; | |
6613 | ||
3664e317 JM |
6614 | case USING_STMT: |
6615 | r = void_node; | |
6616 | break; | |
6617 | ||
cb57504a JM |
6618 | case TEMPLATE_ID_EXPR: |
6619 | { | |
6620 | /* We can evaluate template-id that refers to a concept only if | |
6621 | the template arguments are non-dependent. */ | |
861d4af8 AS |
6622 | tree id = unpack_concept_check (t); |
6623 | tree tmpl = TREE_OPERAND (id, 0); | |
6624 | if (!concept_definition_p (tmpl)) | |
cb57504a JM |
6625 | internal_error ("unexpected template-id %qE", t); |
6626 | ||
861d4af8 AS |
6627 | if (function_concept_p (tmpl)) |
6628 | { | |
6629 | if (!ctx->quiet) | |
6630 | error_at (cp_expr_loc_or_input_loc (t), | |
6631 | "function concept must be called"); | |
6632 | r = error_mark_node; | |
6633 | break; | |
6634 | } | |
6635 | ||
6d1556ec PP |
6636 | if (!processing_template_decl |
6637 | && !uid_sensitive_constexpr_evaluation_p ()) | |
861d4af8 | 6638 | r = evaluate_concept_check (t, tf_warning_or_error); |
cb57504a JM |
6639 | else |
6640 | *non_constant_p = true; | |
861d4af8 AS |
6641 | |
6642 | break; | |
cb57504a JM |
6643 | } |
6644 | ||
529bc410 MP |
6645 | case ASM_EXPR: |
6646 | if (!ctx->quiet) | |
6821245b | 6647 | inline_asm_in_constexpr_error (loc); |
529bc410 MP |
6648 | *non_constant_p = true; |
6649 | return t; | |
6650 | ||
2d76680f | 6651 | default: |
c6e7c499 JM |
6652 | if (STATEMENT_CODE_P (TREE_CODE (t))) |
6653 | { | |
6654 | /* This function doesn't know how to deal with pre-genericize | |
6655 | statements; this can only happen with statement-expressions, | |
6656 | so for now just fail. */ | |
6657 | if (!ctx->quiet) | |
6658 | error_at (EXPR_LOCATION (t), | |
64d6d399 | 6659 | "statement is not a constant expression"); |
c6e7c499 JM |
6660 | } |
6661 | else | |
6662 | internal_error ("unexpected expression %qE of kind %s", t, | |
6663 | get_tree_code_name (TREE_CODE (t))); | |
2d76680f PC |
6664 | *non_constant_p = true; |
6665 | break; | |
6666 | } | |
6667 | ||
6668 | if (r == error_mark_node) | |
6669 | *non_constant_p = true; | |
6670 | ||
6671 | if (*non_constant_p) | |
6672 | return t; | |
6673 | else | |
6674 | return r; | |
6675 | } | |
6676 | ||
e079dced JM |
6677 | /* P0859: A function is needed for constant evaluation if it is a constexpr |
6678 | function that is named by an expression ([basic.def.odr]) that is | |
6679 | potentially constant evaluated. | |
6680 | ||
6681 | So we need to instantiate any constexpr functions mentioned by the | |
6682 | expression even if the definition isn't needed for evaluating the | |
6683 | expression. */ | |
6684 | ||
6685 | static tree | |
6686 | instantiate_cx_fn_r (tree *tp, int *walk_subtrees, void */*data*/) | |
6687 | { | |
6688 | if (TREE_CODE (*tp) == FUNCTION_DECL | |
6689 | && DECL_DECLARED_CONSTEXPR_P (*tp) | |
6690 | && !DECL_INITIAL (*tp) | |
4fdda3ce | 6691 | && !trivial_fn_p (*tp) |
f65a3299 PP |
6692 | && DECL_TEMPLOID_INSTANTIATION (*tp) |
6693 | && !uid_sensitive_constexpr_evaluation_p ()) | |
e079dced JM |
6694 | { |
6695 | ++function_depth; | |
6696 | instantiate_decl (*tp, /*defer_ok*/false, /*expl_inst*/false); | |
6697 | --function_depth; | |
6698 | } | |
6699 | else if (TREE_CODE (*tp) == CALL_EXPR | |
6700 | || TREE_CODE (*tp) == AGGR_INIT_EXPR) | |
6701 | { | |
6702 | if (EXPR_HAS_LOCATION (*tp)) | |
6703 | input_location = EXPR_LOCATION (*tp); | |
6704 | } | |
6705 | ||
6706 | if (!EXPR_P (*tp)) | |
6707 | *walk_subtrees = 0; | |
6708 | ||
6709 | return NULL_TREE; | |
6710 | } | |
8e007055 | 6711 | |
e079dced JM |
6712 | static void |
6713 | instantiate_constexpr_fns (tree t) | |
6714 | { | |
6715 | location_t loc = input_location; | |
6716 | cp_walk_tree_without_duplicates (&t, instantiate_cx_fn_r, NULL); | |
6717 | input_location = loc; | |
6718 | } | |
6719 | ||
8e007055 JJ |
6720 | /* Look for heap variables in the expression *TP. */ |
6721 | ||
6722 | static tree | |
6723 | find_heap_var_refs (tree *tp, int *walk_subtrees, void */*data*/) | |
6724 | { | |
6725 | if (VAR_P (*tp) | |
6726 | && (DECL_NAME (*tp) == heap_uninit_identifier | |
6727 | || DECL_NAME (*tp) == heap_identifier | |
815baade JJ |
6728 | || DECL_NAME (*tp) == heap_vec_uninit_identifier |
6729 | || DECL_NAME (*tp) == heap_vec_identifier | |
8e007055 JJ |
6730 | || DECL_NAME (*tp) == heap_deleted_identifier)) |
6731 | return *tp; | |
6732 | ||
6733 | if (TYPE_P (*tp)) | |
6734 | *walk_subtrees = 0; | |
6735 | return NULL_TREE; | |
6736 | } | |
6737 | ||
f968ef9b JJ |
6738 | /* Find immediate function decls in *TP if any. */ |
6739 | ||
6740 | static tree | |
6741 | find_immediate_fndecl (tree *tp, int */*walk_subtrees*/, void */*data*/) | |
6742 | { | |
6743 | if (TREE_CODE (*tp) == FUNCTION_DECL && DECL_IMMEDIATE_FUNCTION_P (*tp)) | |
6744 | return *tp; | |
6745 | return NULL_TREE; | |
6746 | } | |
6747 | ||
e4082611 | 6748 | /* ALLOW_NON_CONSTANT is false if T is required to be a constant expression. |
d4accef3 JM |
6749 | STRICT has the same sense as for constant_value_1: true if we only allow |
6750 | conforming C++ constant expressions, or false if we want a constant value | |
6751 | even if it doesn't conform. | |
13de99bc | 6752 | MANIFESTLY_CONST_EVAL is true if T is manifestly const-evaluated as |
8e007055 JJ |
6753 | per P0595 even when ALLOW_NON_CONSTANT is true. |
6754 | CONSTEXPR_DTOR is true when evaluating the dtor of a constexpr variable. | |
6755 | OBJECT must be non-NULL in that case. */ | |
e4082611 | 6756 | |
2d76680f | 6757 | static tree |
3e605b20 | 6758 | cxx_eval_outermost_constant_expr (tree t, bool allow_non_constant, |
e4082611 | 6759 | bool strict = true, |
13de99bc | 6760 | bool manifestly_const_eval = false, |
8e007055 | 6761 | bool constexpr_dtor = false, |
f65a3299 | 6762 | tree object = NULL_TREE) |
2d76680f | 6763 | { |
8108ea30 JM |
6764 | auto_timevar time (TV_CONSTEXPR); |
6765 | ||
2d76680f PC |
6766 | bool non_constant_p = false; |
6767 | bool overflow_p = false; | |
39dce2b7 | 6768 | |
d419e176 MP |
6769 | if (BRACE_ENCLOSED_INITIALIZER_P (t)) |
6770 | { | |
6771 | gcc_checking_assert (allow_non_constant); | |
6772 | return t; | |
6773 | } | |
6774 | ||
8e007055 | 6775 | constexpr_global_ctx global_ctx; |
49a86fce | 6776 | constexpr_ctx ctx = { &global_ctx, NULL, NULL, NULL, NULL, NULL, NULL, |
8e007055 | 6777 | allow_non_constant, strict, |
f65a3299 | 6778 | manifestly_const_eval || !allow_non_constant }; |
39dce2b7 | 6779 | |
6641d6d3 JJ |
6780 | /* Turn off -frounding-math for manifestly constant evaluation. */ |
6781 | warning_sentinel rm (flag_rounding_math, ctx.manifestly_const_eval); | |
3e605b20 | 6782 | tree type = initialized_type (t); |
3e605b20 | 6783 | tree r = t; |
f968ef9b | 6784 | bool is_consteval = false; |
4d0c18c6 | 6785 | if (VOID_TYPE_P (type)) |
8e007055 JJ |
6786 | { |
6787 | if (constexpr_dtor) | |
6788 | /* Used for destructors of array elements. */ | |
6789 | type = TREE_TYPE (object); | |
6790 | else | |
f968ef9b | 6791 | { |
b04445d4 | 6792 | if (cxx_dialect < cxx20) |
f968ef9b JJ |
6793 | return t; |
6794 | if (TREE_CODE (t) != CALL_EXPR && TREE_CODE (t) != AGGR_INIT_EXPR) | |
6795 | return t; | |
6796 | /* Calls to immediate functions returning void need to be | |
6797 | evaluated. */ | |
6798 | tree fndecl = cp_get_callee_fndecl_nofold (t); | |
6799 | if (fndecl == NULL_TREE || !DECL_IMMEDIATE_FUNCTION_P (fndecl)) | |
6800 | return t; | |
6801 | else | |
6802 | is_consteval = true; | |
6803 | } | |
6804 | } | |
b04445d4 | 6805 | else if (cxx_dialect >= cxx20 |
f968ef9b JJ |
6806 | && (TREE_CODE (t) == CALL_EXPR |
6807 | || TREE_CODE (t) == AGGR_INIT_EXPR | |
6808 | || TREE_CODE (t) == TARGET_EXPR)) | |
6809 | { | |
861d4af8 AS |
6810 | /* For non-concept checks, determine if it is consteval. */ |
6811 | if (!concept_check_p (t)) | |
6812 | { | |
6813 | tree x = t; | |
6814 | if (TREE_CODE (x) == TARGET_EXPR) | |
6815 | x = TARGET_EXPR_INITIAL (x); | |
6816 | tree fndecl = cp_get_callee_fndecl_nofold (x); | |
6817 | if (fndecl && DECL_IMMEDIATE_FUNCTION_P (fndecl)) | |
6818 | is_consteval = true; | |
6819 | } | |
8e007055 | 6820 | } |
3e605b20 JM |
6821 | if (AGGREGATE_TYPE_P (type) || VECTOR_TYPE_P (type)) |
6822 | { | |
6823 | /* In C++14 an NSDMI can participate in aggregate initialization, | |
6824 | and can refer to the address of the object being initialized, so | |
6825 | we need to pass in the relevant VAR_DECL if we want to do the | |
6826 | evaluation in a single pass. The evaluation will dynamically | |
6827 | update ctx.values for the VAR_DECL. We use the same strategy | |
6828 | for C++11 constexpr constructors that refer to the object being | |
6829 | initialized. */ | |
8e007055 JJ |
6830 | if (constexpr_dtor) |
6831 | { | |
6832 | gcc_assert (object && VAR_P (object)); | |
6833 | gcc_assert (DECL_DECLARED_CONSTEXPR_P (object)); | |
6834 | gcc_assert (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (object)); | |
fce6467b JJ |
6835 | if (error_operand_p (DECL_INITIAL (object))) |
6836 | return t; | |
8e007055 JJ |
6837 | ctx.ctor = unshare_expr (DECL_INITIAL (object)); |
6838 | TREE_READONLY (ctx.ctor) = false; | |
6839 | /* Temporarily force decl_really_constant_value to return false | |
6840 | for it, we want to use ctx.ctor for the current value instead. */ | |
6841 | DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (object) = false; | |
6842 | } | |
6843 | else | |
6844 | { | |
6845 | ctx.ctor = build_constructor (type, NULL); | |
6846 | CONSTRUCTOR_NO_CLEARING (ctx.ctor) = true; | |
6847 | } | |
60813a46 JM |
6848 | if (!object) |
6849 | { | |
6850 | if (TREE_CODE (t) == TARGET_EXPR) | |
6851 | object = TARGET_EXPR_SLOT (t); | |
6852 | else if (TREE_CODE (t) == AGGR_INIT_EXPR) | |
6853 | object = AGGR_INIT_EXPR_SLOT (t); | |
6854 | } | |
3e605b20 JM |
6855 | ctx.object = object; |
6856 | if (object) | |
6857 | gcc_assert (same_type_ignoring_top_level_qualifiers_p | |
6858 | (type, TREE_TYPE (object))); | |
6859 | if (object && DECL_P (object)) | |
8e007055 | 6860 | global_ctx.values.put (object, ctx.ctor); |
3e605b20 JM |
6861 | if (TREE_CODE (r) == TARGET_EXPR) |
6862 | /* Avoid creating another CONSTRUCTOR when we expand the | |
6863 | TARGET_EXPR. */ | |
6864 | r = TARGET_EXPR_INITIAL (r); | |
6865 | } | |
6866 | ||
ee1de08d JJ |
6867 | auto_vec<tree, 16> cleanups; |
6868 | global_ctx.cleanups = &cleanups; | |
6869 | ||
f65a3299 | 6870 | instantiate_constexpr_fns (r); |
2b3ab879 | 6871 | r = cxx_eval_constant_expression (&ctx, r, |
5a804683 | 6872 | false, &non_constant_p, &overflow_p); |
2d76680f | 6873 | |
8e007055 JJ |
6874 | if (!constexpr_dtor) |
6875 | verify_constant (r, allow_non_constant, &non_constant_p, &overflow_p); | |
6876 | else | |
6877 | DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (object) = true; | |
2d76680f | 6878 | |
ee1de08d JJ |
6879 | unsigned int i; |
6880 | tree cleanup; | |
6881 | /* Evaluate the cleanups. */ | |
6882 | FOR_EACH_VEC_ELT_REVERSE (cleanups, i, cleanup) | |
6883 | cxx_eval_constant_expression (&ctx, cleanup, false, | |
6884 | &non_constant_p, &overflow_p); | |
6885 | ||
023d89c7 JM |
6886 | /* Mutable logic is a bit tricky: we want to allow initialization of |
6887 | constexpr variables with mutable members, but we can't copy those | |
6888 | members to another constexpr variable. */ | |
8e007055 | 6889 | if (TREE_CODE (r) == CONSTRUCTOR && CONSTRUCTOR_MUTABLE_POISON (r)) |
2d76680f | 6890 | { |
2d76680f | 6891 | if (!allow_non_constant) |
023d89c7 JM |
6892 | error ("%qE is not a constant expression because it refers to " |
6893 | "mutable subobjects of %qT", t, type); | |
2d76680f PC |
6894 | non_constant_p = true; |
6895 | } | |
6896 | ||
8e007055 | 6897 | if (TREE_CODE (r) == CONSTRUCTOR && CONSTRUCTOR_NO_CLEARING (r)) |
f64e0c02 JM |
6898 | { |
6899 | if (!allow_non_constant) | |
6900 | error ("%qE is not a constant expression because it refers to " | |
6901 | "an incompletely initialized variable", t); | |
6902 | TREE_CONSTANT (r) = false; | |
6903 | non_constant_p = true; | |
6904 | } | |
6905 | ||
8e007055 JJ |
6906 | if (!global_ctx.heap_vars.is_empty ()) |
6907 | { | |
6908 | tree heap_var = cp_walk_tree_without_duplicates (&r, find_heap_var_refs, | |
6909 | NULL); | |
6910 | unsigned int i; | |
6911 | if (heap_var) | |
6912 | { | |
6913 | if (!allow_non_constant && !non_constant_p) | |
6914 | error_at (DECL_SOURCE_LOCATION (heap_var), | |
6915 | "%qE is not a constant expression because it refers to " | |
6916 | "a result of %<operator new%>", t); | |
6917 | r = t; | |
6918 | non_constant_p = true; | |
6919 | } | |
6920 | FOR_EACH_VEC_ELT (global_ctx.heap_vars, i, heap_var) | |
6921 | if (DECL_NAME (heap_var) != heap_deleted_identifier) | |
6922 | { | |
6923 | if (!allow_non_constant && !non_constant_p) | |
6924 | error_at (DECL_SOURCE_LOCATION (heap_var), | |
6925 | "%qE is not a constant expression because allocated " | |
6926 | "storage has not been deallocated", t); | |
6927 | r = t; | |
6928 | non_constant_p = true; | |
6929 | } | |
6930 | } | |
6931 | ||
f968ef9b JJ |
6932 | /* Check that immediate invocation does not return an expression referencing |
6933 | any immediate function decls. They need to be allowed while parsing | |
6934 | immediate functions, but can't leak outside of them. */ | |
6935 | if (is_consteval | |
6936 | && t != r | |
6937 | && (current_function_decl == NULL_TREE | |
6938 | || !DECL_IMMEDIATE_FUNCTION_P (current_function_decl))) | |
6939 | if (tree immediate_fndecl | |
6940 | = cp_walk_tree_without_duplicates (&r, find_immediate_fndecl, | |
6941 | NULL)) | |
6942 | { | |
6943 | if (!allow_non_constant && !non_constant_p) | |
6944 | error_at (cp_expr_loc_or_input_loc (t), | |
6945 | "immediate evaluation returns address of immediate " | |
6946 | "function %qD", immediate_fndecl); | |
6947 | r = t; | |
6948 | non_constant_p = true; | |
6949 | } | |
6950 | ||
8895443a JM |
6951 | if (non_constant_p) |
6952 | /* If we saw something bad, go back to our argument. The wrapping below is | |
6953 | only for the cases of TREE_CONSTANT argument or overflow. */ | |
6954 | r = t; | |
2d76680f PC |
6955 | |
6956 | if (!non_constant_p && overflow_p) | |
6957 | non_constant_p = true; | |
6958 | ||
e0804c9b | 6959 | /* Unshare the result. */ |
56cfb596 | 6960 | bool should_unshare = true; |
e0804c9b JM |
6961 | if (r == t || (TREE_CODE (t) == TARGET_EXPR |
6962 | && TARGET_EXPR_INITIAL (t) == r)) | |
56cfb596 PP |
6963 | should_unshare = false; |
6964 | ||
2d76680f PC |
6965 | if (non_constant_p && !allow_non_constant) |
6966 | return error_mark_node; | |
8e007055 JJ |
6967 | else if (constexpr_dtor) |
6968 | return r; | |
2d76680f PC |
6969 | else if (non_constant_p && TREE_CONSTANT (r)) |
6970 | { | |
eddd715c JM |
6971 | /* This isn't actually constant, so unset TREE_CONSTANT. |
6972 | Don't clear TREE_CONSTANT on ADDR_EXPR, as the middle-end requires | |
6973 | it to be set if it is invariant address, even when it is not | |
6974 | a valid C++ constant expression. Wrap it with a NOP_EXPR | |
6975 | instead. */ | |
6976 | if (EXPR_P (r) && TREE_CODE (r) != ADDR_EXPR) | |
2d76680f PC |
6977 | r = copy_node (r); |
6978 | else if (TREE_CODE (r) == CONSTRUCTOR) | |
6979 | r = build1 (VIEW_CONVERT_EXPR, TREE_TYPE (r), r); | |
6980 | else | |
6981 | r = build_nop (TREE_TYPE (r), r); | |
6982 | TREE_CONSTANT (r) = false; | |
6983 | } | |
5dab8b11 | 6984 | else if (non_constant_p) |
2d76680f PC |
6985 | return t; |
6986 | ||
56cfb596 PP |
6987 | if (should_unshare) |
6988 | r = unshare_expr (r); | |
6989 | ||
2d76680f PC |
6990 | if (TREE_CODE (r) == CONSTRUCTOR && CLASS_TYPE_P (TREE_TYPE (r))) |
6991 | { | |
5dab8b11 | 6992 | r = adjust_temp_type (type, r); |
2d76680f PC |
6993 | if (TREE_CODE (t) == TARGET_EXPR |
6994 | && TARGET_EXPR_INITIAL (t) == r) | |
6995 | return t; | |
5dab8b11 | 6996 | else if (TREE_CODE (t) != CONSTRUCTOR) |
2d76680f | 6997 | { |
8e007055 | 6998 | r = get_target_expr_sfinae (r, tf_warning_or_error | tf_no_cleanup); |
2d76680f | 6999 | TREE_CONSTANT (r) = true; |
2d76680f PC |
7000 | } |
7001 | } | |
5dab8b11 JM |
7002 | |
7003 | return r; | |
2d76680f PC |
7004 | } |
7005 | ||
2d76680f PC |
7006 | /* If T represents a constant expression returns its reduced value. |
7007 | Otherwise return error_mark_node. If T is dependent, then | |
7008 | return NULL. */ | |
7009 | ||
7010 | tree | |
3e605b20 | 7011 | cxx_constant_value (tree t, tree decl) |
2d76680f | 7012 | { |
8e007055 JJ |
7013 | return cxx_eval_outermost_constant_expr (t, false, true, true, false, decl); |
7014 | } | |
7015 | ||
7016 | /* Like cxx_constant_value, but used for evaluation of constexpr destructors | |
7017 | of constexpr variables. The actual initializer of DECL is not modified. */ | |
7018 | ||
7019 | void | |
7020 | cxx_constant_dtor (tree t, tree decl) | |
7021 | { | |
7022 | cxx_eval_outermost_constant_expr (t, false, true, true, true, decl); | |
2d76680f PC |
7023 | } |
7024 | ||
cda0a029 JM |
7025 | /* Helper routine for fold_simple function. Either return simplified |
7026 | expression T, otherwise NULL_TREE. | |
7027 | In contrast to cp_fully_fold, and to maybe_constant_value, we try to fold | |
7028 | even if we are within template-declaration. So be careful on call, as in | |
7029 | such case types can be undefined. */ | |
7030 | ||
7031 | static tree | |
7032 | fold_simple_1 (tree t) | |
7033 | { | |
7034 | tree op1; | |
7035 | enum tree_code code = TREE_CODE (t); | |
7036 | ||
7037 | switch (code) | |
7038 | { | |
7039 | case INTEGER_CST: | |
7040 | case REAL_CST: | |
7041 | case VECTOR_CST: | |
7042 | case FIXED_CST: | |
7043 | case COMPLEX_CST: | |
7044 | return t; | |
7045 | ||
7046 | case SIZEOF_EXPR: | |
7047 | return fold_sizeof_expr (t); | |
7048 | ||
7049 | case ABS_EXPR: | |
e28fadbc | 7050 | case ABSU_EXPR: |
cda0a029 JM |
7051 | case CONJ_EXPR: |
7052 | case REALPART_EXPR: | |
7053 | case IMAGPART_EXPR: | |
7054 | case NEGATE_EXPR: | |
7055 | case BIT_NOT_EXPR: | |
7056 | case TRUTH_NOT_EXPR: | |
7057 | case NOP_EXPR: | |
7058 | case VIEW_CONVERT_EXPR: | |
7059 | case CONVERT_EXPR: | |
7060 | case FLOAT_EXPR: | |
7061 | case FIX_TRUNC_EXPR: | |
7062 | case FIXED_CONVERT_EXPR: | |
7063 | case ADDR_SPACE_CONVERT_EXPR: | |
7064 | ||
7065 | op1 = TREE_OPERAND (t, 0); | |
7066 | ||
7067 | t = const_unop (code, TREE_TYPE (t), op1); | |
7068 | if (!t) | |
7069 | return NULL_TREE; | |
7070 | ||
7071 | if (CONVERT_EXPR_CODE_P (code) | |
7072 | && TREE_OVERFLOW_P (t) && !TREE_OVERFLOW_P (op1)) | |
7073 | TREE_OVERFLOW (t) = false; | |
7074 | return t; | |
7075 | ||
7076 | default: | |
7077 | return NULL_TREE; | |
7078 | } | |
7079 | } | |
7080 | ||
7081 | /* If T is a simple constant expression, returns its simplified value. | |
dba99244 | 7082 | Otherwise returns T. In contrast to maybe_constant_value we |
cda0a029 JM |
7083 | simplify only few operations on constant-expressions, and we don't |
7084 | try to simplify constexpressions. */ | |
7085 | ||
7086 | tree | |
7087 | fold_simple (tree t) | |
7088 | { | |
cda0a029 JM |
7089 | if (processing_template_decl) |
7090 | return t; | |
7091 | ||
dba99244 MP |
7092 | tree r = fold_simple_1 (t); |
7093 | if (r) | |
7094 | return r; | |
cda0a029 | 7095 | |
dba99244 | 7096 | return t; |
cda0a029 JM |
7097 | } |
7098 | ||
2d76680f PC |
7099 | /* If T is a constant expression, returns its reduced value. |
7100 | Otherwise, if T does not have TREE_CONSTANT set, returns T. | |
13de99bc JJ |
7101 | Otherwise, returns a version of T without TREE_CONSTANT. |
7102 | MANIFESTLY_CONST_EVAL is true if T is manifestly const-evaluated | |
f65a3299 | 7103 | as per P0595. */ |
2d76680f | 7104 | |
8a87daca JM |
7105 | static GTY((deletable)) hash_map<tree, tree> *cv_cache; |
7106 | ||
7107 | tree | |
f65a3299 | 7108 | maybe_constant_value (tree t, tree decl, bool manifestly_const_eval) |
2d76680f PC |
7109 | { |
7110 | tree r; | |
7111 | ||
a0ab7ccd | 7112 | if (!is_nondependent_constant_expression (t)) |
2d76680f PC |
7113 | { |
7114 | if (TREE_OVERFLOW_P (t)) | |
7115 | { | |
7116 | t = build_nop (TREE_TYPE (t), t); | |
7117 | TREE_CONSTANT (t) = false; | |
7118 | } | |
7119 | return t; | |
7120 | } | |
8a87daca JM |
7121 | else if (CONSTANT_CLASS_P (t)) |
7122 | /* No caching or evaluation needed. */ | |
7123 | return t; | |
7124 | ||
13de99bc | 7125 | if (manifestly_const_eval) |
f65a3299 | 7126 | return cxx_eval_outermost_constant_expr (t, true, true, true, false, decl); |
13de99bc | 7127 | |
8a87daca JM |
7128 | if (cv_cache == NULL) |
7129 | cv_cache = hash_map<tree, tree>::create_ggc (101); | |
7130 | if (tree *cached = cv_cache->get (t)) | |
173c8def JM |
7131 | { |
7132 | r = *cached; | |
7133 | if (r != t) | |
7134 | { | |
9f143008 | 7135 | r = break_out_target_exprs (r, /*clear_loc*/true); |
173c8def JM |
7136 | protected_set_expr_location (r, EXPR_LOCATION (t)); |
7137 | } | |
dfffecb8 | 7138 | return r; |
173c8def | 7139 | } |
2d76680f | 7140 | |
f65a3299 PP |
7141 | uid_sensitive_constexpr_evaluation_checker c; |
7142 | r = cxx_eval_outermost_constant_expr (t, true, true, false, false, decl); | |
595278be MM |
7143 | gcc_checking_assert (r == t |
7144 | || CONVERT_EXPR_P (t) | |
7145 | || TREE_CODE (t) == VIEW_CONVERT_EXPR | |
7146 | || (TREE_CONSTANT (t) && !TREE_CONSTANT (r)) | |
7147 | || !cp_tree_equal (r, t)); | |
f65a3299 PP |
7148 | if (!c.evaluation_restricted_p ()) |
7149 | cv_cache->put (t, r); | |
2d76680f PC |
7150 | return r; |
7151 | } | |
7152 | ||
7a7ac32a PP |
7153 | /* Dispose of the whole CV_CACHE. */ |
7154 | ||
7155 | static void | |
7156 | clear_cv_cache (void) | |
7157 | { | |
7158 | if (cv_cache != NULL) | |
7159 | cv_cache->empty (); | |
7160 | } | |
7161 | ||
bebabf70 | 7162 | /* Dispose of the whole CV_CACHE and FOLD_CACHE. */ |
1e297006 MP |
7163 | |
7164 | void | |
bebabf70 | 7165 | clear_cv_and_fold_caches () |
1e297006 | 7166 | { |
7a7ac32a | 7167 | clear_cv_cache (); |
eba9e839 | 7168 | clear_fold_cache (); |
1e297006 MP |
7169 | } |
7170 | ||
a81c8e8c MP |
7171 | /* Internal function handling expressions in templates for |
7172 | fold_non_dependent_expr and fold_non_dependent_init. | |
7173 | ||
7174 | If we're in a template, but T isn't value dependent, simplify | |
7175 | it. We're supposed to treat: | |
7176 | ||
7177 | template <typename T> void f(T[1 + 1]); | |
7178 | template <typename T> void f(T[2]); | |
7179 | ||
7180 | as two declarations of the same function, for example. */ | |
7181 | ||
7182 | static tree | |
7183 | fold_non_dependent_expr_template (tree t, tsubst_flags_t complain, | |
f968ef9b JJ |
7184 | bool manifestly_const_eval, |
7185 | tree object) | |
a81c8e8c MP |
7186 | { |
7187 | gcc_assert (processing_template_decl); | |
7188 | ||
7189 | if (is_nondependent_constant_expression (t)) | |
7190 | { | |
7191 | processing_template_decl_sentinel s; | |
7192 | t = instantiate_non_dependent_expr_internal (t, complain); | |
7193 | ||
7194 | if (type_unknown_p (t) || BRACE_ENCLOSED_INITIALIZER_P (t)) | |
7195 | { | |
7196 | if (TREE_OVERFLOW_P (t)) | |
7197 | { | |
7198 | t = build_nop (TREE_TYPE (t), t); | |
7199 | TREE_CONSTANT (t) = false; | |
7200 | } | |
7201 | return t; | |
7202 | } | |
7203 | ||
7204 | tree r = cxx_eval_outermost_constant_expr (t, true, true, | |
7205 | manifestly_const_eval, | |
f968ef9b | 7206 | false, object); |
a81c8e8c MP |
7207 | /* cp_tree_equal looks through NOPs, so allow them. */ |
7208 | gcc_checking_assert (r == t | |
7209 | || CONVERT_EXPR_P (t) | |
7210 | || TREE_CODE (t) == VIEW_CONVERT_EXPR | |
7211 | || (TREE_CONSTANT (t) && !TREE_CONSTANT (r)) | |
7212 | || !cp_tree_equal (r, t)); | |
7213 | return r; | |
7214 | } | |
7215 | else if (TREE_OVERFLOW_P (t)) | |
7216 | { | |
7217 | t = build_nop (TREE_TYPE (t), t); | |
7218 | TREE_CONSTANT (t) = false; | |
7219 | } | |
7220 | ||
7221 | return t; | |
7222 | } | |
7223 | ||
234bef96 PC |
7224 | /* Like maybe_constant_value but first fully instantiate the argument. |
7225 | ||
7226 | Note: this is equivalent to instantiate_non_dependent_expr_sfinae | |
e56f6629 JM |
7227 | (t, complain) followed by maybe_constant_value but is more efficient, |
7228 | because it calls instantiation_dependent_expression_p and | |
7229 | potential_constant_expression at most once. | |
4cd3e7df | 7230 | The manifestly_const_eval argument is passed to maybe_constant_value. |
e56f6629 JM |
7231 | |
7232 | Callers should generally pass their active complain, or if they are in a | |
7233 | non-template, diagnosing context, they can use the default of | |
7234 | tf_warning_or_error. Callers that might be within a template context, don't | |
7235 | have a complain parameter, and aren't going to remember the result for long | |
7236 | (e.g. null_ptr_cst_p), can pass tf_none and deal with error_mark_node | |
7237 | appropriately. */ | |
234bef96 PC |
7238 | |
7239 | tree | |
e56f6629 | 7240 | fold_non_dependent_expr (tree t, |
4cd3e7df | 7241 | tsubst_flags_t complain /* = tf_warning_or_error */, |
f968ef9b JJ |
7242 | bool manifestly_const_eval /* = false */, |
7243 | tree object /* = NULL_TREE */) | |
234bef96 PC |
7244 | { |
7245 | if (t == NULL_TREE) | |
7246 | return NULL_TREE; | |
7247 | ||
a81c8e8c MP |
7248 | if (processing_template_decl) |
7249 | return fold_non_dependent_expr_template (t, complain, | |
f968ef9b | 7250 | manifestly_const_eval, object); |
234bef96 | 7251 | |
f968ef9b | 7252 | return maybe_constant_value (t, object, manifestly_const_eval); |
a81c8e8c | 7253 | } |
234bef96 | 7254 | |
ae2ebf01 MP |
7255 | /* Like fold_non_dependent_expr, but if EXPR couldn't be folded to a constant, |
7256 | return the original expression. */ | |
7257 | ||
7258 | tree | |
7259 | maybe_fold_non_dependent_expr (tree expr, | |
7260 | tsubst_flags_t complain/*=tf_warning_or_error*/) | |
7261 | { | |
7262 | tree t = fold_non_dependent_expr (expr, complain); | |
7263 | if (t && TREE_CONSTANT (t)) | |
7264 | return t; | |
7265 | ||
7266 | return expr; | |
7267 | } | |
234bef96 | 7268 | |
a81c8e8c | 7269 | /* Like maybe_constant_init but first fully instantiate the argument. */ |
234bef96 | 7270 | |
a81c8e8c MP |
7271 | tree |
7272 | fold_non_dependent_init (tree t, | |
7273 | tsubst_flags_t complain /*=tf_warning_or_error*/, | |
69bf1c7d MP |
7274 | bool manifestly_const_eval /*=false*/, |
7275 | tree object /* = NULL_TREE */) | |
a81c8e8c MP |
7276 | { |
7277 | if (t == NULL_TREE) | |
7278 | return NULL_TREE; | |
7279 | ||
7280 | if (processing_template_decl) | |
7281 | { | |
7282 | t = fold_non_dependent_expr_template (t, complain, | |
69bf1c7d | 7283 | manifestly_const_eval, object); |
a81c8e8c MP |
7284 | /* maybe_constant_init does this stripping, so do it here too. */ |
7285 | if (TREE_CODE (t) == TARGET_EXPR) | |
234bef96 | 7286 | { |
a81c8e8c MP |
7287 | tree init = TARGET_EXPR_INITIAL (t); |
7288 | if (TREE_CODE (init) == CONSTRUCTOR) | |
7289 | t = init; | |
234bef96 PC |
7290 | } |
7291 | return t; | |
7292 | } | |
7293 | ||
69bf1c7d | 7294 | return maybe_constant_init (t, object, manifestly_const_eval); |
234bef96 PC |
7295 | } |
7296 | ||
2d76680f | 7297 | /* Like maybe_constant_value, but returns a CONSTRUCTOR directly, rather |
e4082611 JJ |
7298 | than wrapped in a TARGET_EXPR. |
7299 | ALLOW_NON_CONSTANT is false if T is required to be a constant expression. | |
13de99bc | 7300 | MANIFESTLY_CONST_EVAL is true if T is manifestly const-evaluated as |
e4082611 | 7301 | per P0595 even when ALLOW_NON_CONSTANT is true. */ |
2d76680f | 7302 | |
118cd6ba | 7303 | static tree |
e4082611 | 7304 | maybe_constant_init_1 (tree t, tree decl, bool allow_non_constant, |
13de99bc | 7305 | bool manifestly_const_eval) |
2d76680f | 7306 | { |
cda0a029 JM |
7307 | if (!t) |
7308 | return t; | |
2d76680f PC |
7309 | if (TREE_CODE (t) == EXPR_STMT) |
7310 | t = TREE_OPERAND (t, 0); | |
7311 | if (TREE_CODE (t) == CONVERT_EXPR | |
7312 | && VOID_TYPE_P (TREE_TYPE (t))) | |
7313 | t = TREE_OPERAND (t, 0); | |
60813a46 JM |
7314 | if (TREE_CODE (t) == INIT_EXPR) |
7315 | t = TREE_OPERAND (t, 1); | |
f64e0c02 JM |
7316 | if (TREE_CODE (t) == TARGET_EXPR) |
7317 | t = TARGET_EXPR_INITIAL (t); | |
a0ab7ccd | 7318 | if (!is_nondependent_static_init_expression (t)) |
69eb4fde | 7319 | /* Don't try to evaluate it. */; |
118cd6ba | 7320 | else if (CONSTANT_CLASS_P (t) && allow_non_constant) |
8a87daca | 7321 | /* No evaluation needed. */; |
69eb4fde | 7322 | else |
e4082611 | 7323 | t = cxx_eval_outermost_constant_expr (t, allow_non_constant, |
38295573 | 7324 | /*strict*/false, |
8e007055 | 7325 | manifestly_const_eval, false, decl); |
2d76680f PC |
7326 | if (TREE_CODE (t) == TARGET_EXPR) |
7327 | { | |
7328 | tree init = TARGET_EXPR_INITIAL (t); | |
7329 | if (TREE_CODE (init) == CONSTRUCTOR) | |
7330 | t = init; | |
7331 | } | |
7332 | return t; | |
7333 | } | |
7334 | ||
118cd6ba MP |
7335 | /* Wrapper for maybe_constant_init_1 which permits non constants. */ |
7336 | ||
7337 | tree | |
13de99bc | 7338 | maybe_constant_init (tree t, tree decl, bool manifestly_const_eval) |
118cd6ba | 7339 | { |
13de99bc | 7340 | return maybe_constant_init_1 (t, decl, true, manifestly_const_eval); |
118cd6ba MP |
7341 | } |
7342 | ||
7343 | /* Wrapper for maybe_constant_init_1 which does not permit non constants. */ | |
7344 | ||
7345 | tree | |
7346 | cxx_constant_init (tree t, tree decl) | |
7347 | { | |
e4082611 | 7348 | return maybe_constant_init_1 (t, decl, false, true); |
118cd6ba MP |
7349 | } |
7350 | ||
2d76680f PC |
7351 | #if 0 |
7352 | /* FIXME see ADDR_EXPR section in potential_constant_expression_1. */ | |
7353 | /* Return true if the object referred to by REF has automatic or thread | |
7354 | local storage. */ | |
7355 | ||
7356 | enum { ck_ok, ck_bad, ck_unknown }; | |
7357 | static int | |
7358 | check_automatic_or_tls (tree ref) | |
7359 | { | |
ef4bddc2 | 7360 | machine_mode mode; |
f37fac2b | 7361 | poly_int64 bitsize, bitpos; |
2d76680f PC |
7362 | tree offset; |
7363 | int volatilep = 0, unsignedp = 0; | |
7364 | tree decl = get_inner_reference (ref, &bitsize, &bitpos, &offset, | |
7365 | &mode, &unsignedp, &volatilep, false); | |
7366 | duration_kind dk; | |
7367 | ||
7368 | /* If there isn't a decl in the middle, we don't know the linkage here, | |
7369 | and this isn't a constant expression anyway. */ | |
7370 | if (!DECL_P (decl)) | |
7371 | return ck_unknown; | |
7372 | dk = decl_storage_duration (decl); | |
7373 | return (dk == dk_auto || dk == dk_thread) ? ck_bad : ck_ok; | |
7374 | } | |
7375 | #endif | |
7376 | ||
c7a53bdb JJ |
7377 | /* Data structure for passing data from potential_constant_expression_1 |
7378 | to check_for_return_continue via cp_walk_tree. */ | |
7379 | struct check_for_return_continue_data { | |
7380 | hash_set<tree> *pset; | |
7381 | tree continue_stmt; | |
7382 | }; | |
7383 | ||
7384 | /* Helper function for potential_constant_expression_1 SWITCH_STMT handling, | |
7385 | called through cp_walk_tree. Return the first RETURN_EXPR found, or note | |
7386 | the first CONTINUE_STMT if RETURN_EXPR is not found. */ | |
7387 | static tree | |
7388 | check_for_return_continue (tree *tp, int *walk_subtrees, void *data) | |
7389 | { | |
7390 | tree t = *tp, s; | |
7391 | check_for_return_continue_data *d = (check_for_return_continue_data *) data; | |
7392 | switch (TREE_CODE (t)) | |
7393 | { | |
7394 | case RETURN_EXPR: | |
7395 | return t; | |
7396 | ||
7397 | case CONTINUE_STMT: | |
7398 | if (d->continue_stmt == NULL_TREE) | |
7399 | d->continue_stmt = t; | |
7400 | break; | |
7401 | ||
7402 | #define RECUR(x) \ | |
7403 | if (tree r = cp_walk_tree (&x, check_for_return_continue, data, \ | |
7404 | d->pset)) \ | |
7405 | return r | |
7406 | ||
7407 | /* For loops, walk subtrees manually, so that continue stmts found | |
7408 | inside of the bodies of the loops are ignored. */ | |
7409 | case DO_STMT: | |
7410 | *walk_subtrees = 0; | |
7411 | RECUR (DO_COND (t)); | |
7412 | s = d->continue_stmt; | |
7413 | RECUR (DO_BODY (t)); | |
7414 | d->continue_stmt = s; | |
7415 | break; | |
7416 | ||
7417 | case WHILE_STMT: | |
7418 | *walk_subtrees = 0; | |
7419 | RECUR (WHILE_COND (t)); | |
7420 | s = d->continue_stmt; | |
7421 | RECUR (WHILE_BODY (t)); | |
7422 | d->continue_stmt = s; | |
7423 | break; | |
7424 | ||
7425 | case FOR_STMT: | |
7426 | *walk_subtrees = 0; | |
7427 | RECUR (FOR_INIT_STMT (t)); | |
7428 | RECUR (FOR_COND (t)); | |
7429 | RECUR (FOR_EXPR (t)); | |
7430 | s = d->continue_stmt; | |
7431 | RECUR (FOR_BODY (t)); | |
7432 | d->continue_stmt = s; | |
7433 | break; | |
7434 | ||
7435 | case RANGE_FOR_STMT: | |
7436 | *walk_subtrees = 0; | |
7437 | RECUR (RANGE_FOR_EXPR (t)); | |
7438 | s = d->continue_stmt; | |
7439 | RECUR (RANGE_FOR_BODY (t)); | |
7440 | d->continue_stmt = s; | |
7441 | break; | |
7442 | #undef RECUR | |
7443 | ||
7444 | case STATEMENT_LIST: | |
7445 | case CONSTRUCTOR: | |
7446 | break; | |
7447 | ||
7448 | default: | |
7449 | if (!EXPR_P (t)) | |
7450 | *walk_subtrees = 0; | |
7451 | break; | |
7452 | } | |
7453 | ||
7454 | return NULL_TREE; | |
7455 | } | |
7456 | ||
2d76680f PC |
7457 | /* Return true if T denotes a potentially constant expression. Issue |
7458 | diagnostic as appropriate under control of FLAGS. If WANT_RVAL is true, | |
a0ab7ccd JM |
7459 | an lvalue-rvalue conversion is implied. If NOW is true, we want to |
7460 | consider the expression in the current context, independent of constexpr | |
7461 | substitution. | |
2d76680f PC |
7462 | |
7463 | C++0x [expr.const] used to say | |
7464 | ||
7465 | 6 An expression is a potential constant expression if it is | |
7466 | a constant expression where all occurrences of function | |
7467 | parameters are replaced by arbitrary constant expressions | |
7468 | of the appropriate type. | |
7469 | ||
7470 | 2 A conditional expression is a constant expression unless it | |
7471 | involves one of the following as a potentially evaluated | |
7472 | subexpression (3.2), but subexpressions of logical AND (5.14), | |
7473 | logical OR (5.15), and conditional (5.16) operations that are | |
7474 | not evaluated are not considered. */ | |
7475 | ||
7476 | static bool | |
a0ab7ccd | 7477 | potential_constant_expression_1 (tree t, bool want_rval, bool strict, bool now, |
3075affd | 7478 | tsubst_flags_t flags, tree *jump_target) |
2d76680f | 7479 | { |
a0ab7ccd | 7480 | #define RECUR(T,RV) \ |
3075affd | 7481 | potential_constant_expression_1 ((T), (RV), strict, now, flags, jump_target) |
a0ab7ccd | 7482 | |
2d76680f PC |
7483 | enum { any = false, rval = true }; |
7484 | int i; | |
7485 | tree tmp; | |
7486 | ||
7487 | if (t == error_mark_node) | |
7488 | return false; | |
7489 | if (t == NULL_TREE) | |
7490 | return true; | |
f9d0ca40 | 7491 | location_t loc = cp_expr_loc_or_input_loc (t); |
3075affd JM |
7492 | |
7493 | if (*jump_target) | |
7494 | /* If we are jumping, ignore everything. This is simpler than the | |
7495 | cxx_eval_constant_expression handling because we only need to be | |
7496 | conservatively correct, and we don't necessarily have a constant value | |
7497 | available, so we don't bother with switch tracking. */ | |
7498 | return true; | |
7499 | ||
3c393a2c | 7500 | if (TREE_THIS_VOLATILE (t) && want_rval) |
2d76680f PC |
7501 | { |
7502 | if (flags & tf_error) | |
3c393a2c MP |
7503 | error_at (loc, "lvalue-to-rvalue conversion of a volatile lvalue " |
7504 | "%qE with type %qT", t, TREE_TYPE (t)); | |
2d76680f PC |
7505 | return false; |
7506 | } | |
7507 | if (CONSTANT_CLASS_P (t)) | |
7508 | return true; | |
7dc2b4a2 JM |
7509 | if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_TYPED) |
7510 | && TREE_TYPE (t) == error_mark_node) | |
7511 | return false; | |
2d76680f PC |
7512 | |
7513 | switch (TREE_CODE (t)) | |
7514 | { | |
7515 | case FUNCTION_DECL: | |
7516 | case BASELINK: | |
7517 | case TEMPLATE_DECL: | |
7518 | case OVERLOAD: | |
7519 | case TEMPLATE_ID_EXPR: | |
7520 | case LABEL_DECL: | |
60813a46 | 7521 | case CASE_LABEL_EXPR: |
81012684 | 7522 | case PREDICT_EXPR: |
2d76680f PC |
7523 | case CONST_DECL: |
7524 | case SIZEOF_EXPR: | |
7525 | case ALIGNOF_EXPR: | |
7526 | case OFFSETOF_EXPR: | |
7527 | case NOEXCEPT_EXPR: | |
7528 | case TEMPLATE_PARM_INDEX: | |
7529 | case TRAIT_EXPR: | |
7530 | case IDENTIFIER_NODE: | |
7531 | case USERDEF_LITERAL: | |
7532 | /* We can see a FIELD_DECL in a pointer-to-member expression. */ | |
7533 | case FIELD_DECL: | |
cda0a029 | 7534 | case RESULT_DECL: |
2d76680f | 7535 | case USING_DECL: |
60813a46 | 7536 | case USING_STMT: |
3e605b20 | 7537 | case PLACEHOLDER_EXPR: |
971e17ff | 7538 | case REQUIRES_EXPR: |
98e5a19a | 7539 | case STATIC_ASSERT: |
96a95ac1 | 7540 | case DEBUG_BEGIN_STMT: |
2d76680f PC |
7541 | return true; |
7542 | ||
3075affd JM |
7543 | case RETURN_EXPR: |
7544 | if (!RECUR (TREE_OPERAND (t, 0), any)) | |
7545 | return false; | |
7546 | /* FALLTHROUGH */ | |
7547 | ||
7548 | case BREAK_STMT: | |
7549 | case CONTINUE_STMT: | |
7550 | *jump_target = t; | |
7551 | return true; | |
7552 | ||
a0ab7ccd | 7553 | case PARM_DECL: |
8fda2c27 | 7554 | if (now && want_rval) |
a0ab7ccd | 7555 | { |
8fda2c27 | 7556 | tree type = TREE_TYPE (t); |
9eb7d0d7 | 7557 | if ((processing_template_decl && !COMPLETE_TYPE_P (type)) |
61466206 | 7558 | || dependent_type_p (type) |
8fda2c27 JM |
7559 | || is_really_empty_class (type, /*ignore_vptr*/false)) |
7560 | /* An empty class has no data to read. */ | |
7561 | return true; | |
a0ab7ccd JM |
7562 | if (flags & tf_error) |
7563 | error ("%qE is not a constant expression", t); | |
7564 | return false; | |
7565 | } | |
7566 | return true; | |
7567 | ||
2d76680f PC |
7568 | case AGGR_INIT_EXPR: |
7569 | case CALL_EXPR: | |
7570 | /* -- an invocation of a function other than a constexpr function | |
7571 | or a constexpr constructor. */ | |
7572 | { | |
7573 | tree fun = get_function_named_in_call (t); | |
7574 | const int nargs = call_expr_nargs (t); | |
7575 | i = 0; | |
7576 | ||
60813a46 JM |
7577 | if (fun == NULL_TREE) |
7578 | { | |
44a845ca MS |
7579 | /* Reset to allow the function to continue past the end |
7580 | of the block below. Otherwise return early. */ | |
7581 | bool bail = true; | |
7582 | ||
35228ac7 JJ |
7583 | if (TREE_CODE (t) == CALL_EXPR |
7584 | && CALL_EXPR_FN (t) == NULL_TREE) | |
7585 | switch (CALL_EXPR_IFN (t)) | |
7586 | { | |
7587 | /* These should be ignored, they are optimized away from | |
7588 | constexpr functions. */ | |
7589 | case IFN_UBSAN_NULL: | |
7590 | case IFN_UBSAN_BOUNDS: | |
7591 | case IFN_UBSAN_VPTR: | |
81fea426 | 7592 | case IFN_FALLTHROUGH: |
35228ac7 | 7593 | return true; |
44a845ca MS |
7594 | |
7595 | case IFN_ADD_OVERFLOW: | |
7596 | case IFN_SUB_OVERFLOW: | |
7597 | case IFN_MUL_OVERFLOW: | |
e16f1cc7 | 7598 | case IFN_LAUNDER: |
d8fcab68 | 7599 | case IFN_VEC_CONVERT: |
44a845ca | 7600 | bail = false; |
d8fcab68 | 7601 | break; |
44a845ca | 7602 | |
35228ac7 JJ |
7603 | default: |
7604 | break; | |
7605 | } | |
44a845ca MS |
7606 | |
7607 | if (bail) | |
7608 | { | |
7609 | /* fold_call_expr can't do anything with IFN calls. */ | |
7610 | if (flags & tf_error) | |
e40b6fc7 | 7611 | error_at (loc, "call to internal function %qE", t); |
44a845ca MS |
7612 | return false; |
7613 | } | |
60813a46 | 7614 | } |
44a845ca MS |
7615 | |
7616 | if (fun && is_overloaded_fn (fun)) | |
2d76680f PC |
7617 | { |
7618 | if (TREE_CODE (fun) == FUNCTION_DECL) | |
7619 | { | |
7620 | if (builtin_valid_in_constant_expr_p (fun)) | |
7621 | return true; | |
7622 | if (!DECL_DECLARED_CONSTEXPR_P (fun) | |
7623 | /* Allow any built-in function; if the expansion | |
7624 | isn't constant, we'll deal with that then. */ | |
8e007055 | 7625 | && !fndecl_built_in_p (fun) |
b04445d4 | 7626 | /* In C++20, replaceable global allocation functions |
8e007055 | 7627 | are constant expressions. */ |
8412b939 JJ |
7628 | && (!cxx_replaceable_global_alloc_fn (fun) |
7629 | || TREE_CODE (t) != CALL_EXPR | |
7630 | || (!CALL_FROM_NEW_OR_DELETE_P (t) | |
7631 | && (current_function_decl == NULL_TREE | |
7632 | || !is_std_allocator_allocate | |
7633 | (current_function_decl)))) | |
cf650568 JJ |
7634 | /* Allow placement new in std::construct_at. */ |
7635 | && (!cxx_placement_new_fn (fun) | |
8412b939 | 7636 | || TREE_CODE (t) != CALL_EXPR |
cf650568 | 7637 | || current_function_decl == NULL_TREE |
22edf943 MP |
7638 | || !is_std_construct_at (current_function_decl)) |
7639 | && !cxx_dynamic_cast_fn_p (fun)) | |
2d76680f PC |
7640 | { |
7641 | if (flags & tf_error) | |
7642 | { | |
84fa214d | 7643 | error_at (loc, "call to non-%<constexpr%> function %qD", |
e40b6fc7 | 7644 | fun); |
2d76680f PC |
7645 | explain_invalid_constexpr_fn (fun); |
7646 | } | |
7647 | return false; | |
7648 | } | |
7649 | /* A call to a non-static member function takes the address | |
7650 | of the object as the first argument. But in a constant | |
7651 | expression the address will be folded away, so look | |
7652 | through it now. */ | |
7653 | if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fun) | |
7654 | && !DECL_CONSTRUCTOR_P (fun)) | |
7655 | { | |
7656 | tree x = get_nth_callarg (t, 0); | |
7657 | if (is_this_parameter (x)) | |
3e605b20 | 7658 | return true; |
a0ab7ccd JM |
7659 | /* Don't require an immediately constant value, as |
7660 | constexpr substitution might not use the value. */ | |
7661 | bool sub_now = false; | |
7662 | if (!potential_constant_expression_1 (x, rval, strict, | |
3075affd JM |
7663 | sub_now, flags, |
7664 | jump_target)) | |
2d76680f PC |
7665 | return false; |
7666 | i = 1; | |
7667 | } | |
7668 | } | |
7669 | else | |
7670 | { | |
69eb4fde | 7671 | if (!RECUR (fun, true)) |
2d76680f PC |
7672 | return false; |
7673 | fun = get_first_fn (fun); | |
7674 | } | |
7675 | /* Skip initial arguments to base constructors. */ | |
7676 | if (DECL_BASE_CONSTRUCTOR_P (fun)) | |
7677 | i = num_artificial_parms_for (fun); | |
7678 | fun = DECL_ORIGIN (fun); | |
7679 | } | |
44a845ca | 7680 | else if (fun) |
2d76680f | 7681 | { |
69eb4fde | 7682 | if (RECUR (fun, rval)) |
2d76680f PC |
7683 | /* Might end up being a constant function pointer. */; |
7684 | else | |
7685 | return false; | |
7686 | } | |
7687 | for (; i < nargs; ++i) | |
7688 | { | |
7689 | tree x = get_nth_callarg (t, i); | |
c3c29ba5 JM |
7690 | /* In a template, reference arguments haven't been converted to |
7691 | REFERENCE_TYPE and we might not even know if the parameter | |
7692 | is a reference, so accept lvalue constants too. */ | |
7693 | bool rv = processing_template_decl ? any : rval; | |
a0ab7ccd JM |
7694 | /* Don't require an immediately constant value, as constexpr |
7695 | substitution might not use the value of the argument. */ | |
7696 | bool sub_now = false; | |
7697 | if (!potential_constant_expression_1 (x, rv, strict, | |
3075affd | 7698 | sub_now, flags, jump_target)) |
2d76680f PC |
7699 | return false; |
7700 | } | |
7701 | return true; | |
7702 | } | |
7703 | ||
7704 | case NON_LVALUE_EXPR: | |
7705 | /* -- an lvalue-to-rvalue conversion (4.1) unless it is applied to | |
7706 | -- an lvalue of integral type that refers to a non-volatile | |
7707 | const variable or static data member initialized with | |
7708 | constant expressions, or | |
7709 | ||
7710 | -- an lvalue of literal type that refers to non-volatile | |
7711 | object defined with constexpr, or that refers to a | |
7712 | sub-object of such an object; */ | |
69eb4fde | 7713 | return RECUR (TREE_OPERAND (t, 0), rval); |
2d76680f PC |
7714 | |
7715 | case VAR_DECL: | |
70f40fea | 7716 | if (DECL_HAS_VALUE_EXPR_P (t)) |
c1051bf7 | 7717 | { |
68ad1bf7 | 7718 | if (now && is_normal_capture_proxy (t)) |
c1051bf7 JM |
7719 | { |
7720 | /* -- in a lambda-expression, a reference to this or to a | |
7721 | variable with automatic storage duration defined outside that | |
7722 | lambda-expression, where the reference would be an | |
7723 | odr-use. */ | |
04b89192 JM |
7724 | |
7725 | if (want_rval) | |
7726 | /* Since we're doing an lvalue-rvalue conversion, this might | |
7727 | not be an odr-use, so evaluate the variable directly. */ | |
7728 | return RECUR (DECL_CAPTURED_VARIABLE (t), rval); | |
7729 | ||
c1051bf7 JM |
7730 | if (flags & tf_error) |
7731 | { | |
7732 | tree cap = DECL_CAPTURED_VARIABLE (t); | |
7733 | error ("lambda capture of %qE is not a constant expression", | |
7734 | cap); | |
04b89192 | 7735 | if (decl_constant_var_p (cap)) |
c1051bf7 JM |
7736 | inform (input_location, "because it is used as a glvalue"); |
7737 | } | |
7738 | return false; | |
7739 | } | |
c2856cee MP |
7740 | /* Treat __PRETTY_FUNCTION__ inside a template function as |
7741 | potentially-constant. */ | |
7742 | else if (DECL_PRETTY_FUNCTION_P (t) | |
7743 | && DECL_VALUE_EXPR (t) == error_mark_node) | |
7744 | return true; | |
c1051bf7 JM |
7745 | return RECUR (DECL_VALUE_EXPR (t), rval); |
7746 | } | |
69eb4fde | 7747 | if (want_rval |
98e5a19a | 7748 | && !var_in_maybe_constexpr_fn (t) |
7dc2b4a2 | 7749 | && !type_dependent_expression_p (t) |
4b691b13 | 7750 | && !decl_maybe_constant_var_p (t) |
69eb4fde JM |
7751 | && (strict |
7752 | || !CP_TYPE_CONST_NON_VOLATILE_P (TREE_TYPE (t)) | |
4b691b13 JM |
7753 | || (DECL_INITIAL (t) |
7754 | && !DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (t))) | |
7dc2b4a2 | 7755 | && COMPLETE_TYPE_P (TREE_TYPE (t)) |
dbcd32f8 | 7756 | && !is_really_empty_class (TREE_TYPE (t), /*ignore_vptr*/false)) |
2d76680f PC |
7757 | { |
7758 | if (flags & tf_error) | |
6821245b | 7759 | non_const_var_error (loc, t); |
2d76680f PC |
7760 | return false; |
7761 | } | |
7762 | return true; | |
7763 | ||
7764 | case NOP_EXPR: | |
ed3ea9f2 JJ |
7765 | if (REINTERPRET_CAST_P (t)) |
7766 | { | |
7767 | if (flags & tf_error) | |
a9c697b8 | 7768 | error_at (loc, "%<reinterpret_cast%> is not a constant expression"); |
ed3ea9f2 JJ |
7769 | return false; |
7770 | } | |
7771 | /* FALLTHRU */ | |
2d76680f PC |
7772 | case CONVERT_EXPR: |
7773 | case VIEW_CONVERT_EXPR: | |
7774 | /* -- a reinterpret_cast. FIXME not implemented, and this rule | |
7775 | may change to something more specific to type-punning (DR 1312). */ | |
7776 | { | |
7777 | tree from = TREE_OPERAND (t, 0); | |
dfd7fdca DM |
7778 | if (location_wrapper_p (t)) |
7779 | return (RECUR (from, want_rval)); | |
7780 | if (INDIRECT_TYPE_P (TREE_TYPE (t))) | |
2d76680f | 7781 | { |
dfd7fdca DM |
7782 | STRIP_ANY_LOCATION_WRAPPER (from); |
7783 | if (TREE_CODE (from) == INTEGER_CST | |
7784 | && !integer_zerop (from)) | |
7785 | { | |
7786 | if (flags & tf_error) | |
a9c697b8 MS |
7787 | error_at (loc, |
7788 | "%<reinterpret_cast%> from integer to pointer"); | |
dfd7fdca DM |
7789 | return false; |
7790 | } | |
2d76680f | 7791 | } |
69eb4fde | 7792 | return (RECUR (from, TREE_CODE (t) != VIEW_CONVERT_EXPR)); |
2d76680f PC |
7793 | } |
7794 | ||
be845b04 JJ |
7795 | case ADDRESSOF_EXPR: |
7796 | /* This is like ADDR_EXPR, except it won't form pointer-to-member. */ | |
7797 | t = TREE_OPERAND (t, 0); | |
7798 | goto handle_addr_expr; | |
7799 | ||
2d76680f PC |
7800 | case ADDR_EXPR: |
7801 | /* -- a unary operator & that is applied to an lvalue that | |
7802 | designates an object with thread or automatic storage | |
7803 | duration; */ | |
7804 | t = TREE_OPERAND (t, 0); | |
7805 | ||
7806 | if (TREE_CODE (t) == OFFSET_REF && PTRMEM_OK_P (t)) | |
7807 | /* A pointer-to-member constant. */ | |
7808 | return true; | |
7809 | ||
be845b04 | 7810 | handle_addr_expr: |
2d76680f PC |
7811 | #if 0 |
7812 | /* FIXME adjust when issue 1197 is fully resolved. For now don't do | |
7813 | any checking here, as we might dereference the pointer later. If | |
7814 | we remove this code, also remove check_automatic_or_tls. */ | |
7815 | i = check_automatic_or_tls (t); | |
7816 | if (i == ck_ok) | |
7817 | return true; | |
7818 | if (i == ck_bad) | |
7819 | { | |
7820 | if (flags & tf_error) | |
7821 | error ("address-of an object %qE with thread local or " | |
7822 | "automatic storage is not a constant expression", t); | |
7823 | return false; | |
7824 | } | |
7825 | #endif | |
69eb4fde | 7826 | return RECUR (t, any); |
2d76680f PC |
7827 | |
7828 | case COMPONENT_REF: | |
2d76680f PC |
7829 | case ARROW_EXPR: |
7830 | case OFFSET_REF: | |
7831 | /* -- a class member access unless its postfix-expression is | |
7832 | of literal type or of pointer to literal type. */ | |
7833 | /* This test would be redundant, as it follows from the | |
7834 | postfix-expression being a potential constant expression. */ | |
19dedccf JM |
7835 | if (type_unknown_p (t)) |
7836 | return true; | |
8fda2c27 JM |
7837 | if (is_overloaded_fn (t)) |
7838 | /* In a template, a COMPONENT_REF of a function expresses ob.fn(), | |
7839 | which uses ob as an lvalue. */ | |
7840 | want_rval = false; | |
7841 | gcc_fallthrough (); | |
7842 | ||
7843 | case REALPART_EXPR: | |
7844 | case IMAGPART_EXPR: | |
7845 | case BIT_FIELD_REF: | |
69eb4fde | 7846 | return RECUR (TREE_OPERAND (t, 0), want_rval); |
2d76680f PC |
7847 | |
7848 | case EXPR_PACK_EXPANSION: | |
69eb4fde | 7849 | return RECUR (PACK_EXPANSION_PATTERN (t), want_rval); |
2d76680f PC |
7850 | |
7851 | case INDIRECT_REF: | |
7852 | { | |
7853 | tree x = TREE_OPERAND (t, 0); | |
7854 | STRIP_NOPS (x); | |
948d0d91 | 7855 | if (is_this_parameter (x) && !is_capture_proxy (x)) |
2d76680f | 7856 | { |
5d4e573b | 7857 | if (!var_in_maybe_constexpr_fn (x)) |
2d76680f PC |
7858 | { |
7859 | if (flags & tf_error) | |
e40b6fc7 | 7860 | error_at (loc, "use of %<this%> in a constant expression"); |
2d76680f PC |
7861 | return false; |
7862 | } | |
2d76680f PC |
7863 | return true; |
7864 | } | |
69eb4fde | 7865 | return RECUR (x, rval); |
2d76680f PC |
7866 | } |
7867 | ||
60813a46 JM |
7868 | case STATEMENT_LIST: |
7869 | { | |
7870 | tree_stmt_iterator i; | |
7871 | for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i)) | |
7872 | { | |
69eb4fde | 7873 | if (!RECUR (tsi_stmt (i), any)) |
60813a46 JM |
7874 | return false; |
7875 | } | |
7876 | return true; | |
7877 | } | |
7878 | break; | |
7879 | ||
7880 | case MODIFY_EXPR: | |
7881 | if (cxx_dialect < cxx14) | |
7882 | goto fail; | |
69eb4fde | 7883 | if (!RECUR (TREE_OPERAND (t, 0), any)) |
60813a46 | 7884 | return false; |
8e007055 JJ |
7885 | /* Just ignore clobbers. */ |
7886 | if (TREE_CLOBBER_P (TREE_OPERAND (t, 1))) | |
7887 | return true; | |
69eb4fde | 7888 | if (!RECUR (TREE_OPERAND (t, 1), rval)) |
60813a46 JM |
7889 | return false; |
7890 | return true; | |
7891 | ||
7892 | case MODOP_EXPR: | |
7893 | if (cxx_dialect < cxx14) | |
7894 | goto fail; | |
69eb4fde | 7895 | if (!RECUR (TREE_OPERAND (t, 0), rval)) |
60813a46 | 7896 | return false; |
69eb4fde | 7897 | if (!RECUR (TREE_OPERAND (t, 2), rval)) |
60813a46 JM |
7898 | return false; |
7899 | return true; | |
7900 | ||
60813a46 | 7901 | case DO_STMT: |
69eb4fde | 7902 | if (!RECUR (DO_COND (t), rval)) |
60813a46 | 7903 | return false; |
69eb4fde | 7904 | if (!RECUR (DO_BODY (t), any)) |
60813a46 | 7905 | return false; |
3075affd JM |
7906 | if (breaks (jump_target) || continues (jump_target)) |
7907 | *jump_target = NULL_TREE; | |
60813a46 JM |
7908 | return true; |
7909 | ||
7910 | case FOR_STMT: | |
69eb4fde | 7911 | if (!RECUR (FOR_INIT_STMT (t), any)) |
60813a46 | 7912 | return false; |
8e9558f0 MP |
7913 | tmp = FOR_COND (t); |
7914 | if (!RECUR (tmp, rval)) | |
60813a46 | 7915 | return false; |
8e9558f0 MP |
7916 | if (tmp) |
7917 | { | |
7918 | if (!processing_template_decl) | |
7919 | tmp = cxx_eval_outermost_constant_expr (tmp, true); | |
a385474c MP |
7920 | /* If we couldn't evaluate the condition, it might not ever be |
7921 | true. */ | |
7922 | if (!integer_onep (tmp)) | |
8e9558f0 MP |
7923 | return true; |
7924 | } | |
69eb4fde | 7925 | if (!RECUR (FOR_EXPR (t), any)) |
60813a46 | 7926 | return false; |
69eb4fde | 7927 | if (!RECUR (FOR_BODY (t), any)) |
60813a46 | 7928 | return false; |
3075affd JM |
7929 | if (breaks (jump_target) || continues (jump_target)) |
7930 | *jump_target = NULL_TREE; | |
60813a46 JM |
7931 | return true; |
7932 | ||
98e5a19a | 7933 | case RANGE_FOR_STMT: |
8112667c MP |
7934 | if (!RECUR (RANGE_FOR_INIT_STMT (t), any)) |
7935 | return false; | |
98e5a19a JM |
7936 | if (!RECUR (RANGE_FOR_EXPR (t), any)) |
7937 | return false; | |
7938 | if (!RECUR (RANGE_FOR_BODY (t), any)) | |
7939 | return false; | |
3075affd JM |
7940 | if (breaks (jump_target) || continues (jump_target)) |
7941 | *jump_target = NULL_TREE; | |
98e5a19a JM |
7942 | return true; |
7943 | ||
60813a46 | 7944 | case WHILE_STMT: |
8e9558f0 MP |
7945 | tmp = WHILE_COND (t); |
7946 | if (!RECUR (tmp, rval)) | |
60813a46 | 7947 | return false; |
8e9558f0 MP |
7948 | if (!processing_template_decl) |
7949 | tmp = cxx_eval_outermost_constant_expr (tmp, true); | |
a385474c MP |
7950 | /* If we couldn't evaluate the condition, it might not ever be true. */ |
7951 | if (!integer_onep (tmp)) | |
8e9558f0 | 7952 | return true; |
69eb4fde | 7953 | if (!RECUR (WHILE_BODY (t), any)) |
60813a46 | 7954 | return false; |
3075affd JM |
7955 | if (breaks (jump_target) || continues (jump_target)) |
7956 | *jump_target = NULL_TREE; | |
60813a46 JM |
7957 | return true; |
7958 | ||
7959 | case SWITCH_STMT: | |
69eb4fde | 7960 | if (!RECUR (SWITCH_STMT_COND (t), rval)) |
60813a46 | 7961 | return false; |
ce965730 | 7962 | /* FIXME we don't check SWITCH_STMT_BODY currently, because even |
c7a53bdb JJ |
7963 | unreachable labels would be checked and it is enough if there is |
7964 | a single switch cond value for which it is a valid constant | |
7965 | expression. We need to check if there are any RETURN_EXPRs | |
7966 | or CONTINUE_STMTs inside of the body though, as in that case | |
7967 | we need to set *jump_target. */ | |
7968 | else | |
7969 | { | |
7970 | hash_set<tree> pset; | |
7971 | check_for_return_continue_data data = { &pset, NULL_TREE }; | |
7972 | if (tree ret_expr | |
7973 | = cp_walk_tree (&SWITCH_STMT_BODY (t), check_for_return_continue, | |
7974 | &data, &pset)) | |
7975 | /* The switch might return. */ | |
7976 | *jump_target = ret_expr; | |
7977 | else if (data.continue_stmt) | |
7978 | /* The switch can't return, but might continue. */ | |
7979 | *jump_target = data.continue_stmt; | |
7980 | } | |
60813a46 JM |
7981 | return true; |
7982 | ||
58611fb6 | 7983 | case STMT_EXPR: |
69eb4fde | 7984 | return RECUR (STMT_EXPR_STMT (t), rval); |
58611fb6 | 7985 | |
2d76680f | 7986 | case LAMBDA_EXPR: |
899ac3b8 JM |
7987 | if (cxx_dialect >= cxx17) |
7988 | /* In C++17 lambdas can be constexpr, don't give up yet. */ | |
7989 | return true; | |
7990 | else if (flags & tf_error) | |
7991 | error_at (loc, "lambda-expression is not a constant expression " | |
7992 | "before C++17"); | |
7993 | return false; | |
7994 | ||
2d76680f PC |
7995 | case DYNAMIC_CAST_EXPR: |
7996 | case PSEUDO_DTOR_EXPR: | |
2d76680f PC |
7997 | case NEW_EXPR: |
7998 | case VEC_NEW_EXPR: | |
7999 | case DELETE_EXPR: | |
8000 | case VEC_DELETE_EXPR: | |
8001 | case THROW_EXPR: | |
e40b6fc7 JJ |
8002 | case OMP_PARALLEL: |
8003 | case OMP_TASK: | |
8004 | case OMP_FOR: | |
897064e2 | 8005 | case OMP_SIMD: |
e40b6fc7 JJ |
8006 | case OMP_DISTRIBUTE: |
8007 | case OMP_TASKLOOP: | |
d81ab49d | 8008 | case OMP_LOOP: |
e40b6fc7 JJ |
8009 | case OMP_TEAMS: |
8010 | case OMP_TARGET_DATA: | |
8011 | case OMP_TARGET: | |
8012 | case OMP_SECTIONS: | |
8013 | case OMP_ORDERED: | |
8014 | case OMP_CRITICAL: | |
8015 | case OMP_SINGLE: | |
8016 | case OMP_SECTION: | |
8017 | case OMP_MASTER: | |
8018 | case OMP_TASKGROUP: | |
8019 | case OMP_TARGET_UPDATE: | |
8020 | case OMP_TARGET_ENTER_DATA: | |
8021 | case OMP_TARGET_EXIT_DATA: | |
2d76680f PC |
8022 | case OMP_ATOMIC: |
8023 | case OMP_ATOMIC_READ: | |
8024 | case OMP_ATOMIC_CAPTURE_OLD: | |
8025 | case OMP_ATOMIC_CAPTURE_NEW: | |
28567c40 | 8026 | case OMP_DEPOBJ: |
e40b6fc7 JJ |
8027 | case OACC_PARALLEL: |
8028 | case OACC_KERNELS: | |
62aee289 | 8029 | case OACC_SERIAL: |
e40b6fc7 JJ |
8030 | case OACC_DATA: |
8031 | case OACC_HOST_DATA: | |
8032 | case OACC_LOOP: | |
8033 | case OACC_CACHE: | |
8034 | case OACC_DECLARE: | |
8035 | case OACC_ENTER_DATA: | |
8036 | case OACC_EXIT_DATA: | |
8037 | case OACC_UPDATE: | |
2d76680f PC |
8038 | /* GCC internal stuff. */ |
8039 | case VA_ARG_EXPR: | |
2d76680f | 8040 | case TRANSACTION_EXPR: |
81b6a6c5 | 8041 | case AT_ENCODE_EXPR: |
60813a46 | 8042 | fail: |
2d76680f | 8043 | if (flags & tf_error) |
e40b6fc7 | 8044 | error_at (loc, "expression %qE is not a constant expression", t); |
2d76680f PC |
8045 | return false; |
8046 | ||
529bc410 | 8047 | case ASM_EXPR: |
7c814975 MP |
8048 | if (flags & tf_error) |
8049 | inline_asm_in_constexpr_error (loc); | |
8050 | return false; | |
529bc410 | 8051 | |
bf8d8309 | 8052 | case OBJ_TYPE_REF: |
b04445d4 JM |
8053 | if (cxx_dialect >= cxx20) |
8054 | /* In C++20 virtual calls can be constexpr, don't give up yet. */ | |
bf8d8309 MP |
8055 | return true; |
8056 | else if (flags & tf_error) | |
a9c697b8 | 8057 | error_at (loc, |
b04445d4 | 8058 | "virtual functions cannot be %<constexpr%> before C++20"); |
bf8d8309 MP |
8059 | return false; |
8060 | ||
2d76680f | 8061 | case TYPEID_EXPR: |
66acfb80 MP |
8062 | /* In C++20, a typeid expression whose operand is of polymorphic |
8063 | class type can be constexpr. */ | |
2d76680f PC |
8064 | { |
8065 | tree e = TREE_OPERAND (t, 0); | |
b04445d4 | 8066 | if (cxx_dialect < cxx20 |
66acfb80 MP |
8067 | && strict |
8068 | && !TYPE_P (e) | |
8069 | && !type_dependent_expression_p (e) | |
2d76680f PC |
8070 | && TYPE_POLYMORPHIC_P (TREE_TYPE (e))) |
8071 | { | |
8072 | if (flags & tf_error) | |
a9c697b8 | 8073 | error_at (loc, "%<typeid%> is not a constant expression " |
e40b6fc7 | 8074 | "because %qE is of polymorphic type", e); |
2d76680f PC |
8075 | return false; |
8076 | } | |
8077 | return true; | |
8078 | } | |
8079 | ||
1af4ebf5 | 8080 | case POINTER_DIFF_EXPR: |
2d76680f | 8081 | case MINUS_EXPR: |
2d76680f PC |
8082 | want_rval = true; |
8083 | goto binary; | |
8084 | ||
8085 | case LT_EXPR: | |
8086 | case LE_EXPR: | |
8087 | case GT_EXPR: | |
8088 | case GE_EXPR: | |
8089 | case EQ_EXPR: | |
8090 | case NE_EXPR: | |
b7689b96 | 8091 | case SPACESHIP_EXPR: |
2d76680f PC |
8092 | want_rval = true; |
8093 | goto binary; | |
8094 | ||
60813a46 JM |
8095 | case PREINCREMENT_EXPR: |
8096 | case POSTINCREMENT_EXPR: | |
8097 | case PREDECREMENT_EXPR: | |
8098 | case POSTDECREMENT_EXPR: | |
8099 | if (cxx_dialect < cxx14) | |
8100 | goto fail; | |
8101 | goto unary; | |
8102 | ||
2d76680f PC |
8103 | case BIT_NOT_EXPR: |
8104 | /* A destructor. */ | |
8105 | if (TYPE_P (TREE_OPERAND (t, 0))) | |
8106 | return true; | |
191816a3 | 8107 | /* fall through. */ |
2d76680f | 8108 | |
2d76680f PC |
8109 | case CONJ_EXPR: |
8110 | case SAVE_EXPR: | |
8111 | case FIX_TRUNC_EXPR: | |
8112 | case FLOAT_EXPR: | |
8113 | case NEGATE_EXPR: | |
8114 | case ABS_EXPR: | |
e197e64e | 8115 | case ABSU_EXPR: |
2d76680f PC |
8116 | case TRUTH_NOT_EXPR: |
8117 | case FIXED_CONVERT_EXPR: | |
8118 | case UNARY_PLUS_EXPR: | |
4856a1f0 PC |
8119 | case UNARY_LEFT_FOLD_EXPR: |
8120 | case UNARY_RIGHT_FOLD_EXPR: | |
60813a46 | 8121 | unary: |
69eb4fde | 8122 | return RECUR (TREE_OPERAND (t, 0), rval); |
2d76680f PC |
8123 | |
8124 | case CAST_EXPR: | |
8125 | case CONST_CAST_EXPR: | |
8126 | case STATIC_CAST_EXPR: | |
8127 | case REINTERPRET_CAST_EXPR: | |
8128 | case IMPLICIT_CONV_EXPR: | |
8129 | if (cxx_dialect < cxx11 | |
8130 | && !dependent_type_p (TREE_TYPE (t)) | |
8131 | && !INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))) | |
8132 | /* In C++98, a conversion to non-integral type can't be part of a | |
8133 | constant expression. */ | |
8134 | { | |
8135 | if (flags & tf_error) | |
e40b6fc7 JJ |
8136 | error_at (loc, |
8137 | "cast to non-integral type %qT in a constant expression", | |
8138 | TREE_TYPE (t)); | |
2d76680f PC |
8139 | return false; |
8140 | } | |
fe0604d3 MP |
8141 | /* This might be a conversion from a class to a (potentially) literal |
8142 | type. Let's consider it potentially constant since the conversion | |
8143 | might be a constexpr user-defined conversion. */ | |
8144 | else if (cxx_dialect >= cxx11 | |
8145 | && (dependent_type_p (TREE_TYPE (t)) | |
8146 | || !COMPLETE_TYPE_P (TREE_TYPE (t)) | |
8147 | || literal_type_p (TREE_TYPE (t))) | |
8148 | && TREE_OPERAND (t, 0)) | |
8149 | { | |
8150 | tree type = TREE_TYPE (TREE_OPERAND (t, 0)); | |
8151 | /* If this is a dependent type, it could end up being a class | |
8152 | with conversions. */ | |
8153 | if (type == NULL_TREE || WILDCARD_TYPE_P (type)) | |
8154 | return true; | |
8155 | /* Or a non-dependent class which has conversions. */ | |
8156 | else if (CLASS_TYPE_P (type) | |
8157 | && (TYPE_HAS_CONVERSION (type) || dependent_scope_p (type))) | |
8158 | return true; | |
8159 | } | |
2d76680f | 8160 | |
69eb4fde | 8161 | return (RECUR (TREE_OPERAND (t, 0), |
9f613f06 | 8162 | !TYPE_REF_P (TREE_TYPE (t)))); |
2d76680f | 8163 | |
60813a46 | 8164 | case BIND_EXPR: |
69eb4fde | 8165 | return RECUR (BIND_EXPR_BODY (t), want_rval); |
60813a46 | 8166 | |
60813a46 JM |
8167 | case CLEANUP_POINT_EXPR: |
8168 | case MUST_NOT_THROW_EXPR: | |
8169 | case TRY_CATCH_EXPR: | |
769430b2 | 8170 | case TRY_BLOCK: |
60813a46 JM |
8171 | case EH_SPEC_BLOCK: |
8172 | case EXPR_STMT: | |
2d76680f PC |
8173 | case PAREN_EXPR: |
8174 | case NON_DEPENDENT_EXPR: | |
8175 | /* For convenience. */ | |
f937929e JM |
8176 | case LOOP_EXPR: |
8177 | case EXIT_EXPR: | |
69eb4fde | 8178 | return RECUR (TREE_OPERAND (t, 0), want_rval); |
2d76680f | 8179 | |
98e5a19a JM |
8180 | case DECL_EXPR: |
8181 | tmp = DECL_EXPR_DECL (t); | |
8182 | if (VAR_P (tmp) && !DECL_ARTIFICIAL (tmp)) | |
8183 | { | |
8184 | if (TREE_STATIC (tmp)) | |
8185 | { | |
8186 | if (flags & tf_error) | |
8187 | error_at (DECL_SOURCE_LOCATION (tmp), "%qD declared " | |
4b691b13 | 8188 | "%<static%> in %<constexpr%> context", tmp); |
98e5a19a JM |
8189 | return false; |
8190 | } | |
8191 | else if (CP_DECL_THREAD_LOCAL_P (tmp)) | |
8192 | { | |
8193 | if (flags & tf_error) | |
8194 | error_at (DECL_SOURCE_LOCATION (tmp), "%qD declared " | |
4b691b13 | 8195 | "%<thread_local%> in %<constexpr%> context", tmp); |
98e5a19a JM |
8196 | return false; |
8197 | } | |
3885527d PC |
8198 | else if (!check_for_uninitialized_const_var |
8199 | (tmp, /*constexpr_context_p=*/true, flags)) | |
8200 | return false; | |
98e5a19a JM |
8201 | } |
8202 | return RECUR (tmp, want_rval); | |
8203 | ||
769430b2 JM |
8204 | case TRY_FINALLY_EXPR: |
8205 | return (RECUR (TREE_OPERAND (t, 0), want_rval) | |
8206 | && RECUR (TREE_OPERAND (t, 1), any)); | |
8207 | ||
2d76680f | 8208 | case SCOPE_REF: |
69eb4fde | 8209 | return RECUR (TREE_OPERAND (t, 1), want_rval); |
2d76680f PC |
8210 | |
8211 | case TARGET_EXPR: | |
d3a9902e JM |
8212 | if (!TARGET_EXPR_DIRECT_INIT_P (t) |
8213 | && !literal_type_p (TREE_TYPE (t))) | |
2d76680f PC |
8214 | { |
8215 | if (flags & tf_error) | |
8216 | { | |
097f82ec | 8217 | auto_diagnostic_group d; |
e40b6fc7 JJ |
8218 | error_at (loc, "temporary of non-literal type %qT in a " |
8219 | "constant expression", TREE_TYPE (t)); | |
2d76680f PC |
8220 | explain_non_literal_class (TREE_TYPE (t)); |
8221 | } | |
8222 | return false; | |
8223 | } | |
191816a3 | 8224 | /* FALLTHRU */ |
2d76680f | 8225 | case INIT_EXPR: |
69eb4fde | 8226 | return RECUR (TREE_OPERAND (t, 1), rval); |
2d76680f PC |
8227 | |
8228 | case CONSTRUCTOR: | |
8229 | { | |
8230 | vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (t); | |
8231 | constructor_elt *ce; | |
8232 | for (i = 0; vec_safe_iterate (v, i, &ce); ++i) | |
69eb4fde | 8233 | if (!RECUR (ce->value, want_rval)) |
2d76680f PC |
8234 | return false; |
8235 | return true; | |
8236 | } | |
8237 | ||
8238 | case TREE_LIST: | |
8239 | { | |
8240 | gcc_assert (TREE_PURPOSE (t) == NULL_TREE | |
8241 | || DECL_P (TREE_PURPOSE (t))); | |
69eb4fde | 8242 | if (!RECUR (TREE_VALUE (t), want_rval)) |
2d76680f PC |
8243 | return false; |
8244 | if (TREE_CHAIN (t) == NULL_TREE) | |
8245 | return true; | |
69eb4fde | 8246 | return RECUR (TREE_CHAIN (t), want_rval); |
2d76680f PC |
8247 | } |
8248 | ||
8249 | case TRUNC_DIV_EXPR: | |
8250 | case CEIL_DIV_EXPR: | |
8251 | case FLOOR_DIV_EXPR: | |
8252 | case ROUND_DIV_EXPR: | |
8253 | case TRUNC_MOD_EXPR: | |
8254 | case CEIL_MOD_EXPR: | |
8255 | case ROUND_MOD_EXPR: | |
8256 | { | |
8257 | tree denom = TREE_OPERAND (t, 1); | |
69eb4fde | 8258 | if (!RECUR (denom, rval)) |
2d76680f PC |
8259 | return false; |
8260 | /* We can't call cxx_eval_outermost_constant_expr on an expression | |
234bef96 | 8261 | that hasn't been through instantiate_non_dependent_expr yet. */ |
2d76680f PC |
8262 | if (!processing_template_decl) |
8263 | denom = cxx_eval_outermost_constant_expr (denom, true); | |
8264 | if (integer_zerop (denom)) | |
8265 | { | |
8266 | if (flags & tf_error) | |
64d6d399 | 8267 | error ("division by zero is not a constant expression"); |
2d76680f PC |
8268 | return false; |
8269 | } | |
8270 | else | |
8271 | { | |
8272 | want_rval = true; | |
69eb4fde | 8273 | return RECUR (TREE_OPERAND (t, 0), want_rval); |
2d76680f PC |
8274 | } |
8275 | } | |
8276 | ||
8277 | case COMPOUND_EXPR: | |
8278 | { | |
8279 | /* check_return_expr sometimes wraps a TARGET_EXPR in a | |
46fdced6 | 8280 | COMPOUND_EXPR; don't get confused. */ |
2d76680f PC |
8281 | tree op0 = TREE_OPERAND (t, 0); |
8282 | tree op1 = TREE_OPERAND (t, 1); | |
8283 | STRIP_NOPS (op1); | |
46fdced6 | 8284 | if (TREE_CODE (op0) == TARGET_EXPR && op1 == TARGET_EXPR_SLOT (op0)) |
69eb4fde | 8285 | return RECUR (op0, want_rval); |
2d76680f PC |
8286 | else |
8287 | goto binary; | |
8288 | } | |
8289 | ||
8290 | /* If the first operand is the non-short-circuit constant, look at | |
8291 | the second operand; otherwise we only care about the first one for | |
8292 | potentiality. */ | |
8293 | case TRUTH_AND_EXPR: | |
8294 | case TRUTH_ANDIF_EXPR: | |
8295 | tmp = boolean_true_node; | |
8296 | goto truth; | |
8297 | case TRUTH_OR_EXPR: | |
8298 | case TRUTH_ORIF_EXPR: | |
8299 | tmp = boolean_false_node; | |
8300 | truth: | |
8301 | { | |
8302 | tree op = TREE_OPERAND (t, 0); | |
69eb4fde | 8303 | if (!RECUR (op, rval)) |
2d76680f PC |
8304 | return false; |
8305 | if (!processing_template_decl) | |
8306 | op = cxx_eval_outermost_constant_expr (op, true); | |
8307 | if (tree_int_cst_equal (op, tmp)) | |
69eb4fde | 8308 | return RECUR (TREE_OPERAND (t, 1), rval); |
2d76680f PC |
8309 | else |
8310 | return true; | |
8311 | } | |
8312 | ||
8313 | case PLUS_EXPR: | |
8314 | case MULT_EXPR: | |
8315 | case POINTER_PLUS_EXPR: | |
8316 | case RDIV_EXPR: | |
8317 | case EXACT_DIV_EXPR: | |
8318 | case MIN_EXPR: | |
8319 | case MAX_EXPR: | |
8320 | case LSHIFT_EXPR: | |
8321 | case RSHIFT_EXPR: | |
81fa6d73 JJ |
8322 | case LROTATE_EXPR: |
8323 | case RROTATE_EXPR: | |
2d76680f PC |
8324 | case BIT_IOR_EXPR: |
8325 | case BIT_XOR_EXPR: | |
8326 | case BIT_AND_EXPR: | |
8327 | case TRUTH_XOR_EXPR: | |
8328 | case UNORDERED_EXPR: | |
8329 | case ORDERED_EXPR: | |
8330 | case UNLT_EXPR: | |
8331 | case UNLE_EXPR: | |
8332 | case UNGT_EXPR: | |
8333 | case UNGE_EXPR: | |
8334 | case UNEQ_EXPR: | |
8335 | case LTGT_EXPR: | |
8336 | case RANGE_EXPR: | |
8337 | case COMPLEX_EXPR: | |
8338 | want_rval = true; | |
8339 | /* Fall through. */ | |
8340 | case ARRAY_REF: | |
8341 | case ARRAY_RANGE_REF: | |
8342 | case MEMBER_REF: | |
8343 | case DOTSTAR_EXPR: | |
41b38772 | 8344 | case MEM_REF: |
4856a1f0 PC |
8345 | case BINARY_LEFT_FOLD_EXPR: |
8346 | case BINARY_RIGHT_FOLD_EXPR: | |
2d76680f PC |
8347 | binary: |
8348 | for (i = 0; i < 2; ++i) | |
69eb4fde | 8349 | if (!RECUR (TREE_OPERAND (t, i), want_rval)) |
2d76680f PC |
8350 | return false; |
8351 | return true; | |
8352 | ||
2d76680f PC |
8353 | case VEC_PERM_EXPR: |
8354 | for (i = 0; i < 3; ++i) | |
69eb4fde | 8355 | if (!RECUR (TREE_OPERAND (t, i), true)) |
2d76680f PC |
8356 | return false; |
8357 | return true; | |
8358 | ||
8359 | case COND_EXPR: | |
b04445d4 | 8360 | if (COND_EXPR_IS_VEC_DELETE (t) && cxx_dialect < cxx20) |
d5bcd6d4 JM |
8361 | { |
8362 | if (flags & tf_error) | |
e40b6fc7 | 8363 | error_at (loc, "%<delete[]%> is not a constant expression"); |
d5bcd6d4 JM |
8364 | return false; |
8365 | } | |
8366 | /* Fall through. */ | |
8367 | case IF_STMT: | |
2d76680f PC |
8368 | case VEC_COND_EXPR: |
8369 | /* If the condition is a known constant, we know which of the legs we | |
8370 | care about; otherwise we only require that the condition and | |
8371 | either of the legs be potentially constant. */ | |
8372 | tmp = TREE_OPERAND (t, 0); | |
69eb4fde | 8373 | if (!RECUR (tmp, rval)) |
2d76680f PC |
8374 | return false; |
8375 | if (!processing_template_decl) | |
8376 | tmp = cxx_eval_outermost_constant_expr (tmp, true); | |
8377 | if (integer_zerop (tmp)) | |
69eb4fde | 8378 | return RECUR (TREE_OPERAND (t, 2), want_rval); |
2d76680f | 8379 | else if (TREE_CODE (tmp) == INTEGER_CST) |
69eb4fde | 8380 | return RECUR (TREE_OPERAND (t, 1), want_rval); |
2d76680f PC |
8381 | for (i = 1; i < 3; ++i) |
8382 | if (potential_constant_expression_1 (TREE_OPERAND (t, i), | |
3075affd JM |
8383 | want_rval, strict, now, |
8384 | tf_none, jump_target)) | |
2d76680f PC |
8385 | return true; |
8386 | if (flags & tf_error) | |
e40b6fc7 | 8387 | error_at (loc, "expression %qE is not a constant expression", t); |
2d76680f PC |
8388 | return false; |
8389 | ||
8390 | case VEC_INIT_EXPR: | |
8391 | if (VEC_INIT_EXPR_IS_CONSTEXPR (t)) | |
8392 | return true; | |
8393 | if (flags & tf_error) | |
8394 | { | |
e40b6fc7 | 8395 | error_at (loc, "non-constant array initialization"); |
2d76680f PC |
8396 | diagnose_non_constexpr_vec_init (t); |
8397 | } | |
8398 | return false; | |
8399 | ||
133bc698 JM |
8400 | case TYPE_DECL: |
8401 | case TAG_DEFN: | |
8402 | /* We can see these in statement-expressions. */ | |
8403 | return true; | |
8404 | ||
baf9ebc8 | 8405 | case CLEANUP_STMT: |
1006c9d4 JJ |
8406 | if (!RECUR (CLEANUP_BODY (t), any)) |
8407 | return false; | |
8408 | if (!CLEANUP_EH_ONLY (t) && !RECUR (CLEANUP_EXPR (t), any)) | |
8409 | return false; | |
8410 | return true; | |
8411 | ||
cda0a029 | 8412 | case EMPTY_CLASS_EXPR: |
46fdced6 | 8413 | return true; |
cda0a029 | 8414 | |
f937929e JM |
8415 | case GOTO_EXPR: |
8416 | { | |
8417 | tree *target = &TREE_OPERAND (t, 0); | |
ab3af181 JJ |
8418 | /* Gotos representing break and continue are OK. */ |
8419 | if (breaks (target) || continues (target)) | |
3075affd JM |
8420 | { |
8421 | *jump_target = *target; | |
8422 | return true; | |
8423 | } | |
ab3af181 | 8424 | if (flags & tf_error) |
e40b6fc7 | 8425 | error_at (loc, "%<goto%> is not a constant expression"); |
ab3af181 | 8426 | return false; |
f937929e JM |
8427 | } |
8428 | ||
6f20c42c MP |
8429 | case LABEL_EXPR: |
8430 | t = LABEL_EXPR_LABEL (t); | |
8431 | if (DECL_ARTIFICIAL (t)) | |
8432 | return true; | |
8433 | else if (flags & tf_error) | |
8434 | error_at (loc, "label definition is not a constant expression"); | |
8435 | return false; | |
8436 | ||
98e09245 | 8437 | case ANNOTATE_EXPR: |
98e09245 JJ |
8438 | return RECUR (TREE_OPERAND (t, 0), rval); |
8439 | ||
49789fd0 IS |
8440 | /* Coroutine await, yield and return expressions are not. */ |
8441 | case CO_AWAIT_EXPR: | |
8442 | case CO_YIELD_EXPR: | |
8443 | case CO_RETURN_EXPR: | |
8444 | return false; | |
8445 | ||
2d76680f | 8446 | default: |
878cffbd | 8447 | if (objc_non_constant_expr_p (t)) |
2d76680f PC |
8448 | return false; |
8449 | ||
8450 | sorry ("unexpected AST of kind %s", get_tree_code_name (TREE_CODE (t))); | |
ab3af181 | 8451 | gcc_unreachable (); |
2d76680f PC |
8452 | return false; |
8453 | } | |
69eb4fde | 8454 | #undef RECUR |
2d76680f PC |
8455 | } |
8456 | ||
3075affd JM |
8457 | bool |
8458 | potential_constant_expression_1 (tree t, bool want_rval, bool strict, bool now, | |
8459 | tsubst_flags_t flags) | |
8460 | { | |
8461 | tree target = NULL_TREE; | |
8462 | return potential_constant_expression_1 (t, want_rval, strict, now, | |
8463 | flags, &target); | |
8464 | } | |
8465 | ||
2d76680f PC |
8466 | /* The main entry point to the above. */ |
8467 | ||
8468 | bool | |
8469 | potential_constant_expression (tree t) | |
8470 | { | |
a0ab7ccd | 8471 | return potential_constant_expression_1 (t, false, true, false, tf_none); |
2d76680f PC |
8472 | } |
8473 | ||
8474 | /* As above, but require a constant rvalue. */ | |
8475 | ||
8476 | bool | |
8477 | potential_rvalue_constant_expression (tree t) | |
8478 | { | |
a0ab7ccd | 8479 | return potential_constant_expression_1 (t, true, true, false, tf_none); |
2d76680f PC |
8480 | } |
8481 | ||
8482 | /* Like above, but complain about non-constant expressions. */ | |
8483 | ||
8484 | bool | |
8485 | require_potential_constant_expression (tree t) | |
8486 | { | |
d8cff23f MP |
8487 | return potential_constant_expression_1 (t, false, true, false, |
8488 | tf_warning_or_error); | |
2d76680f PC |
8489 | } |
8490 | ||
8491 | /* Cross product of the above. */ | |
8492 | ||
8493 | bool | |
8494 | require_potential_rvalue_constant_expression (tree t) | |
8495 | { | |
d8cff23f MP |
8496 | return potential_constant_expression_1 (t, true, true, false, |
8497 | tf_warning_or_error); | |
8498 | } | |
8499 | ||
8500 | /* Like above, but don't consider PARM_DECL a potential_constant_expression. */ | |
8501 | ||
8502 | bool | |
8503 | require_rvalue_constant_expression (tree t) | |
8504 | { | |
8505 | return potential_constant_expression_1 (t, true, true, true, | |
8506 | tf_warning_or_error); | |
a0ab7ccd JM |
8507 | } |
8508 | ||
8509 | /* Like potential_constant_expression, but don't consider possible constexpr | |
8510 | substitution of the current function. That is, PARM_DECL qualifies under | |
8511 | potential_constant_expression, but not here. | |
8512 | ||
8513 | This is basically what you can check when any actual constant values might | |
8514 | be value-dependent. */ | |
8515 | ||
8516 | bool | |
8517 | is_constant_expression (tree t) | |
8518 | { | |
8519 | return potential_constant_expression_1 (t, false, true, true, tf_none); | |
8520 | } | |
8521 | ||
beb019d3 JM |
8522 | /* As above, but expect an rvalue. */ |
8523 | ||
8524 | bool | |
8525 | is_rvalue_constant_expression (tree t) | |
8526 | { | |
8527 | return potential_constant_expression_1 (t, true, true, true, tf_none); | |
8528 | } | |
8529 | ||
a0ab7ccd JM |
8530 | /* Like above, but complain about non-constant expressions. */ |
8531 | ||
8532 | bool | |
8533 | require_constant_expression (tree t) | |
8534 | { | |
8535 | return potential_constant_expression_1 (t, false, true, true, | |
8536 | tf_warning_or_error); | |
8537 | } | |
8538 | ||
8539 | /* Like is_constant_expression, but allow const variables that are not allowed | |
8540 | under constexpr rules. */ | |
8541 | ||
8542 | bool | |
8543 | is_static_init_expression (tree t) | |
8544 | { | |
8545 | return potential_constant_expression_1 (t, false, false, true, tf_none); | |
2d76680f PC |
8546 | } |
8547 | ||
eb07f187 JM |
8548 | /* Returns true if T is a potential constant expression that is not |
8549 | instantiation-dependent, and therefore a candidate for constant folding even | |
8550 | in a template. */ | |
8551 | ||
8552 | bool | |
a0ab7ccd | 8553 | is_nondependent_constant_expression (tree t) |
eb07f187 JM |
8554 | { |
8555 | return (!type_unknown_p (t) | |
a0ab7ccd | 8556 | && is_constant_expression (t) |
eb07f187 JM |
8557 | && !instantiation_dependent_expression_p (t)); |
8558 | } | |
8559 | ||
8560 | /* Returns true if T is a potential static initializer expression that is not | |
8561 | instantiation-dependent. */ | |
8562 | ||
8563 | bool | |
a0ab7ccd | 8564 | is_nondependent_static_init_expression (tree t) |
eb07f187 JM |
8565 | { |
8566 | return (!type_unknown_p (t) | |
a0ab7ccd | 8567 | && is_static_init_expression (t) |
eb07f187 JM |
8568 | && !instantiation_dependent_expression_p (t)); |
8569 | } | |
8570 | ||
97f3003f JM |
8571 | /* Finalize constexpr processing after parsing. */ |
8572 | ||
8573 | void | |
8574 | fini_constexpr (void) | |
8575 | { | |
8576 | /* The contexpr call and fundef copies tables are no longer needed. */ | |
8577 | constexpr_call_table = NULL; | |
8578 | fundef_copies_table = NULL; | |
8579 | } | |
8580 | ||
2d76680f | 8581 | #include "gt-cp-constexpr.h" |