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f9885b8a | 1 | /* Perform -*- C++ -*- constant expression evaluation, including calls to |
2 | constexpr functions. These routines are used both during actual parsing | |
09b42213 | 3 | and during the instantiation of template functions. |
4 | ||
aad93da1 | 5 | Copyright (C) 1998-2017 Free Software Foundation, Inc. |
09b42213 | 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" | |
09b42213 | 26 | #include "cp-tree.h" |
4cba6f60 | 27 | #include "varasm.h" |
09b42213 | 28 | #include "c-family/c-objc.h" |
29 | #include "tree-iterator.h" | |
30 | #include "gimplify.h" | |
31 | #include "builtins.h" | |
9c96033c | 32 | #include "tree-inline.h" |
6b71bdb4 | 33 | #include "ubsan.h" |
732905bb | 34 | #include "gimple-fold.h" |
c300fe28 | 35 | #include "timevar.h" |
09b42213 | 36 | |
37 | static bool verify_constant (tree, bool, bool *, bool *); | |
38 | #define VERIFY_CONSTANT(X) \ | |
39 | do { \ | |
f83e6885 | 40 | if (verify_constant ((X), ctx->quiet, non_constant_p, overflow_p)) \ |
09b42213 | 41 | return t; \ |
42 | } while (0) | |
43 | ||
44 | /* Returns true iff FUN is an instantiation of a constexpr function | |
45 | template or a defaulted constexpr function. */ | |
46 | ||
47 | bool | |
48 | is_instantiation_of_constexpr (tree fun) | |
49 | { | |
50 | return ((DECL_TEMPLOID_INSTANTIATION (fun) | |
51 | && DECL_DECLARED_CONSTEXPR_P (DECL_TI_TEMPLATE (fun))) | |
52 | || (DECL_DEFAULTED_FN (fun) | |
53 | && DECL_DECLARED_CONSTEXPR_P (fun))); | |
54 | } | |
55 | ||
56 | /* Return true if T is a literal type. */ | |
57 | ||
58 | bool | |
59 | literal_type_p (tree t) | |
60 | { | |
61 | if (SCALAR_TYPE_P (t) | |
76249021 | 62 | || VECTOR_TYPE_P (t) |
dd418b39 | 63 | || TREE_CODE (t) == REFERENCE_TYPE |
64 | || (VOID_TYPE_P (t) && cxx_dialect >= cxx14)) | |
09b42213 | 65 | return true; |
66 | if (CLASS_TYPE_P (t)) | |
67 | { | |
68 | t = complete_type (t); | |
69 | gcc_assert (COMPLETE_TYPE_P (t) || errorcount); | |
70 | return CLASSTYPE_LITERAL_P (t); | |
71 | } | |
72 | if (TREE_CODE (t) == ARRAY_TYPE) | |
73 | return literal_type_p (strip_array_types (t)); | |
74 | return false; | |
75 | } | |
76 | ||
77 | /* If DECL is a variable declared `constexpr', require its type | |
78 | be literal. Return the DECL if OK, otherwise NULL. */ | |
79 | ||
80 | tree | |
81 | ensure_literal_type_for_constexpr_object (tree decl) | |
82 | { | |
83 | tree type = TREE_TYPE (decl); | |
84 | if (VAR_P (decl) | |
85 | && (DECL_DECLARED_CONSTEXPR_P (decl) | |
86 | || var_in_constexpr_fn (decl)) | |
87 | && !processing_template_decl) | |
88 | { | |
89 | tree stype = strip_array_types (type); | |
90 | if (CLASS_TYPE_P (stype) && !COMPLETE_TYPE_P (complete_type (stype))) | |
91 | /* Don't complain here, we'll complain about incompleteness | |
92 | when we try to initialize the variable. */; | |
93 | else if (!literal_type_p (type)) | |
94 | { | |
95 | if (DECL_DECLARED_CONSTEXPR_P (decl)) | |
e45408ff | 96 | { |
97 | error ("the type %qT of constexpr variable %qD is not literal", | |
98 | type, decl); | |
99 | explain_non_literal_class (type); | |
100 | } | |
09b42213 | 101 | else |
9c96033c | 102 | { |
e45408ff | 103 | if (!DECL_TEMPLATE_INSTANTIATION (current_function_decl)) |
104 | { | |
105 | error ("variable %qD of non-literal type %qT in %<constexpr%> " | |
106 | "function", decl, type); | |
107 | explain_non_literal_class (type); | |
108 | } | |
9c96033c | 109 | cp_function_chain->invalid_constexpr = true; |
110 | } | |
09b42213 | 111 | return NULL; |
112 | } | |
113 | } | |
114 | return decl; | |
115 | } | |
116 | ||
117 | /* Representation of entries in the constexpr function definition table. */ | |
118 | ||
119 | struct GTY((for_user)) constexpr_fundef { | |
120 | tree decl; | |
121 | tree body; | |
122 | }; | |
123 | ||
b594087e | 124 | struct constexpr_fundef_hasher : ggc_ptr_hash<constexpr_fundef> |
09b42213 | 125 | { |
126 | static hashval_t hash (constexpr_fundef *); | |
127 | static bool equal (constexpr_fundef *, constexpr_fundef *); | |
128 | }; | |
129 | ||
130 | /* This table holds all constexpr function definitions seen in | |
131 | the current translation unit. */ | |
132 | ||
133 | static GTY (()) hash_table<constexpr_fundef_hasher> *constexpr_fundef_table; | |
134 | ||
135 | /* Utility function used for managing the constexpr function table. | |
136 | Return true if the entries pointed to by P and Q are for the | |
137 | same constexpr function. */ | |
138 | ||
139 | inline bool | |
140 | constexpr_fundef_hasher::equal (constexpr_fundef *lhs, constexpr_fundef *rhs) | |
141 | { | |
142 | return lhs->decl == rhs->decl; | |
143 | } | |
144 | ||
145 | /* Utility function used for managing the constexpr function table. | |
146 | Return a hash value for the entry pointed to by Q. */ | |
147 | ||
148 | inline hashval_t | |
149 | constexpr_fundef_hasher::hash (constexpr_fundef *fundef) | |
150 | { | |
151 | return DECL_UID (fundef->decl); | |
152 | } | |
153 | ||
154 | /* Return a previously saved definition of function FUN. */ | |
155 | ||
156 | static constexpr_fundef * | |
157 | retrieve_constexpr_fundef (tree fun) | |
158 | { | |
159 | constexpr_fundef fundef = { NULL, NULL }; | |
160 | if (constexpr_fundef_table == NULL) | |
161 | return NULL; | |
162 | ||
163 | fundef.decl = fun; | |
164 | return constexpr_fundef_table->find (&fundef); | |
165 | } | |
166 | ||
167 | /* Check whether the parameter and return types of FUN are valid for a | |
168 | constexpr function, and complain if COMPLAIN. */ | |
169 | ||
33603066 | 170 | bool |
09b42213 | 171 | is_valid_constexpr_fn (tree fun, bool complain) |
172 | { | |
173 | bool ret = true; | |
174 | ||
7896267d | 175 | if (DECL_INHERITED_CTOR (fun) |
09b42213 | 176 | && TREE_CODE (fun) == TEMPLATE_DECL) |
177 | { | |
178 | ret = false; | |
179 | if (complain) | |
180 | error ("inherited constructor %qD is not constexpr", | |
7896267d | 181 | DECL_INHERITED_CTOR (fun)); |
09b42213 | 182 | } |
183 | else | |
184 | { | |
185 | for (tree parm = FUNCTION_FIRST_USER_PARM (fun); | |
186 | parm != NULL_TREE; parm = TREE_CHAIN (parm)) | |
187 | if (!literal_type_p (TREE_TYPE (parm))) | |
188 | { | |
189 | ret = false; | |
190 | if (complain) | |
191 | { | |
192 | error ("invalid type for parameter %d of constexpr " | |
193 | "function %q+#D", DECL_PARM_INDEX (parm), fun); | |
194 | explain_non_literal_class (TREE_TYPE (parm)); | |
195 | } | |
196 | } | |
197 | } | |
198 | ||
199 | if (!DECL_CONSTRUCTOR_P (fun)) | |
200 | { | |
201 | tree rettype = TREE_TYPE (TREE_TYPE (fun)); | |
202 | if (!literal_type_p (rettype)) | |
203 | { | |
204 | ret = false; | |
205 | if (complain) | |
206 | { | |
207 | error ("invalid return type %qT of constexpr function %q+D", | |
208 | rettype, fun); | |
209 | explain_non_literal_class (rettype); | |
210 | } | |
211 | } | |
212 | ||
d66f34cf | 213 | /* C++14 DR 1684 removed this restriction. */ |
214 | if (cxx_dialect < cxx14 | |
215 | && DECL_NONSTATIC_MEMBER_FUNCTION_P (fun) | |
09b42213 | 216 | && !CLASSTYPE_LITERAL_P (DECL_CONTEXT (fun))) |
217 | { | |
218 | ret = false; | |
d66f34cf | 219 | if (complain |
220 | && pedwarn (DECL_SOURCE_LOCATION (fun), OPT_Wpedantic, | |
221 | "enclosing class of constexpr non-static member " | |
222 | "function %q+#D is not a literal type", fun)) | |
223 | explain_non_literal_class (DECL_CONTEXT (fun)); | |
09b42213 | 224 | } |
225 | } | |
226 | else if (CLASSTYPE_VBASECLASSES (DECL_CONTEXT (fun))) | |
227 | { | |
228 | ret = false; | |
229 | if (complain) | |
230 | error ("%q#T has virtual base classes", DECL_CONTEXT (fun)); | |
231 | } | |
232 | ||
233 | return ret; | |
234 | } | |
235 | ||
236 | /* Subroutine of build_data_member_initialization. MEMBER is a COMPONENT_REF | |
237 | for a member of an anonymous aggregate, INIT is the initializer for that | |
238 | member, and VEC_OUTER is the vector of constructor elements for the class | |
239 | whose constructor we are processing. Add the initializer to the vector | |
240 | and return true to indicate success. */ | |
241 | ||
242 | static bool | |
243 | build_anon_member_initialization (tree member, tree init, | |
244 | vec<constructor_elt, va_gc> **vec_outer) | |
245 | { | |
246 | /* MEMBER presents the relevant fields from the inside out, but we need | |
247 | to build up the initializer from the outside in so that we can reuse | |
248 | previously built CONSTRUCTORs if this is, say, the second field in an | |
249 | anonymous struct. So we use a vec as a stack. */ | |
250 | auto_vec<tree, 2> fields; | |
251 | do | |
252 | { | |
253 | fields.safe_push (TREE_OPERAND (member, 1)); | |
254 | member = TREE_OPERAND (member, 0); | |
255 | } | |
256 | while (ANON_AGGR_TYPE_P (TREE_TYPE (member)) | |
257 | && TREE_CODE (member) == COMPONENT_REF); | |
258 | ||
259 | /* VEC has the constructor elements vector for the context of FIELD. | |
260 | If FIELD is an anonymous aggregate, we will push inside it. */ | |
261 | vec<constructor_elt, va_gc> **vec = vec_outer; | |
262 | tree field; | |
263 | while (field = fields.pop(), | |
264 | ANON_AGGR_TYPE_P (TREE_TYPE (field))) | |
265 | { | |
266 | tree ctor; | |
267 | /* If there is already an outer constructor entry for the anonymous | |
268 | aggregate FIELD, use it; otherwise, insert one. */ | |
269 | if (vec_safe_is_empty (*vec) | |
270 | || (*vec)->last().index != field) | |
271 | { | |
272 | ctor = build_constructor (TREE_TYPE (field), NULL); | |
273 | CONSTRUCTOR_APPEND_ELT (*vec, field, ctor); | |
274 | } | |
275 | else | |
276 | ctor = (*vec)->last().value; | |
277 | vec = &CONSTRUCTOR_ELTS (ctor); | |
278 | } | |
279 | ||
280 | /* Now we're at the innermost field, the one that isn't an anonymous | |
281 | aggregate. Add its initializer to the CONSTRUCTOR and we're done. */ | |
282 | gcc_assert (fields.is_empty()); | |
283 | CONSTRUCTOR_APPEND_ELT (*vec, field, init); | |
284 | ||
285 | return true; | |
286 | } | |
287 | ||
288 | /* Subroutine of build_constexpr_constructor_member_initializers. | |
289 | The expression tree T represents a data member initialization | |
290 | in a (constexpr) constructor definition. Build a pairing of | |
291 | the data member with its initializer, and prepend that pair | |
292 | to the existing initialization pair INITS. */ | |
293 | ||
294 | static bool | |
295 | build_data_member_initialization (tree t, vec<constructor_elt, va_gc> **vec) | |
296 | { | |
297 | tree member, init; | |
298 | if (TREE_CODE (t) == CLEANUP_POINT_EXPR) | |
299 | t = TREE_OPERAND (t, 0); | |
300 | if (TREE_CODE (t) == EXPR_STMT) | |
301 | t = TREE_OPERAND (t, 0); | |
302 | if (t == error_mark_node) | |
303 | return false; | |
304 | if (TREE_CODE (t) == STATEMENT_LIST) | |
305 | { | |
306 | tree_stmt_iterator i; | |
307 | for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i)) | |
308 | { | |
309 | if (! build_data_member_initialization (tsi_stmt (i), vec)) | |
310 | return false; | |
311 | } | |
312 | return true; | |
313 | } | |
314 | if (TREE_CODE (t) == CLEANUP_STMT) | |
315 | { | |
316 | /* We can't see a CLEANUP_STMT in a constructor for a literal class, | |
317 | but we can in a constexpr constructor for a non-literal class. Just | |
318 | ignore it; either all the initialization will be constant, in which | |
319 | case the cleanup can't run, or it can't be constexpr. | |
320 | Still recurse into CLEANUP_BODY. */ | |
321 | return build_data_member_initialization (CLEANUP_BODY (t), vec); | |
322 | } | |
323 | if (TREE_CODE (t) == CONVERT_EXPR) | |
324 | t = TREE_OPERAND (t, 0); | |
325 | if (TREE_CODE (t) == INIT_EXPR | |
9c96033c | 326 | /* vptr initialization shows up as a MODIFY_EXPR. In C++14 we only |
327 | use what this function builds for cx_check_missing_mem_inits, and | |
328 | assignment in the ctor body doesn't count. */ | |
329 | || (cxx_dialect < cxx14 && TREE_CODE (t) == MODIFY_EXPR)) | |
09b42213 | 330 | { |
331 | member = TREE_OPERAND (t, 0); | |
332 | init = break_out_target_exprs (TREE_OPERAND (t, 1)); | |
333 | } | |
334 | else if (TREE_CODE (t) == CALL_EXPR) | |
335 | { | |
9c96033c | 336 | tree fn = get_callee_fndecl (t); |
337 | if (!fn || !DECL_CONSTRUCTOR_P (fn)) | |
338 | /* We're only interested in calls to subobject constructors. */ | |
339 | return true; | |
09b42213 | 340 | member = CALL_EXPR_ARG (t, 0); |
341 | /* We don't use build_cplus_new here because it complains about | |
342 | abstract bases. Leaving the call unwrapped means that it has the | |
343 | wrong type, but cxx_eval_constant_expression doesn't care. */ | |
344 | init = break_out_target_exprs (t); | |
345 | } | |
346 | else if (TREE_CODE (t) == BIND_EXPR) | |
347 | return build_data_member_initialization (BIND_EXPR_BODY (t), vec); | |
09b42213 | 348 | else |
9c96033c | 349 | /* Don't add anything else to the CONSTRUCTOR. */ |
350 | return true; | |
09b42213 | 351 | if (INDIRECT_REF_P (member)) |
352 | member = TREE_OPERAND (member, 0); | |
353 | if (TREE_CODE (member) == NOP_EXPR) | |
354 | { | |
355 | tree op = member; | |
356 | STRIP_NOPS (op); | |
357 | if (TREE_CODE (op) == ADDR_EXPR) | |
358 | { | |
359 | gcc_assert (same_type_ignoring_top_level_qualifiers_p | |
360 | (TREE_TYPE (TREE_TYPE (op)), | |
361 | TREE_TYPE (TREE_TYPE (member)))); | |
362 | /* Initializing a cv-qualified member; we need to look through | |
363 | the const_cast. */ | |
364 | member = op; | |
365 | } | |
366 | else if (op == current_class_ptr | |
367 | && (same_type_ignoring_top_level_qualifiers_p | |
368 | (TREE_TYPE (TREE_TYPE (member)), | |
369 | current_class_type))) | |
370 | /* Delegating constructor. */ | |
371 | member = op; | |
372 | else | |
373 | { | |
374 | /* This is an initializer for an empty base; keep it for now so | |
375 | we can check it in cxx_eval_bare_aggregate. */ | |
376 | gcc_assert (is_empty_class (TREE_TYPE (TREE_TYPE (member)))); | |
377 | } | |
378 | } | |
379 | if (TREE_CODE (member) == ADDR_EXPR) | |
380 | member = TREE_OPERAND (member, 0); | |
381 | if (TREE_CODE (member) == COMPONENT_REF) | |
382 | { | |
383 | tree aggr = TREE_OPERAND (member, 0); | |
4952bc85 | 384 | if (TREE_CODE (aggr) == VAR_DECL) |
385 | /* Initializing a local variable, don't add anything. */ | |
386 | return true; | |
09b42213 | 387 | if (TREE_CODE (aggr) != COMPONENT_REF) |
388 | /* Normal member initialization. */ | |
389 | member = TREE_OPERAND (member, 1); | |
390 | else if (ANON_AGGR_TYPE_P (TREE_TYPE (aggr))) | |
391 | /* Initializing a member of an anonymous union. */ | |
392 | return build_anon_member_initialization (member, init, vec); | |
393 | else | |
394 | /* We're initializing a vtable pointer in a base. Leave it as | |
395 | COMPONENT_REF so we remember the path to get to the vfield. */ | |
396 | gcc_assert (TREE_TYPE (member) == vtbl_ptr_type_node); | |
397 | } | |
398 | ||
c678e23e | 399 | /* Value-initialization can produce multiple initializers for the |
400 | same field; use the last one. */ | |
401 | if (!vec_safe_is_empty (*vec) && (*vec)->last().index == member) | |
402 | (*vec)->last().value = init; | |
403 | else | |
404 | CONSTRUCTOR_APPEND_ELT (*vec, member, init); | |
09b42213 | 405 | return true; |
406 | } | |
407 | ||
408 | /* Subroutine of check_constexpr_ctor_body_1 and constexpr_fn_retval. | |
409 | In C++11 mode checks that the TYPE_DECLs in the BIND_EXPR_VARS of a | |
410 | BIND_EXPR conform to 7.1.5/3/4 on typedef and alias declarations. */ | |
411 | ||
412 | static bool | |
413 | check_constexpr_bind_expr_vars (tree t) | |
414 | { | |
415 | gcc_assert (TREE_CODE (t) == BIND_EXPR); | |
416 | ||
09b42213 | 417 | for (tree var = BIND_EXPR_VARS (t); var; var = DECL_CHAIN (var)) |
418 | if (TREE_CODE (var) == TYPE_DECL | |
04103c39 | 419 | && DECL_IMPLICIT_TYPEDEF_P (var) |
420 | && !LAMBDA_TYPE_P (TREE_TYPE (var))) | |
09b42213 | 421 | return false; |
422 | return true; | |
423 | } | |
424 | ||
425 | /* Subroutine of check_constexpr_ctor_body. */ | |
426 | ||
427 | static bool | |
428 | check_constexpr_ctor_body_1 (tree last, tree list) | |
429 | { | |
430 | switch (TREE_CODE (list)) | |
431 | { | |
432 | case DECL_EXPR: | |
810702a2 | 433 | if (TREE_CODE (DECL_EXPR_DECL (list)) == USING_DECL |
434 | || TREE_CODE (DECL_EXPR_DECL (list)) == TYPE_DECL) | |
09b42213 | 435 | return true; |
09b42213 | 436 | return false; |
437 | ||
438 | case CLEANUP_POINT_EXPR: | |
439 | return check_constexpr_ctor_body (last, TREE_OPERAND (list, 0), | |
440 | /*complain=*/false); | |
441 | ||
442 | case BIND_EXPR: | |
443 | if (!check_constexpr_bind_expr_vars (list) | |
444 | || !check_constexpr_ctor_body (last, BIND_EXPR_BODY (list), | |
445 | /*complain=*/false)) | |
446 | return false; | |
447 | return true; | |
448 | ||
449 | case USING_STMT: | |
450 | case STATIC_ASSERT: | |
451 | return true; | |
452 | ||
453 | default: | |
454 | return false; | |
455 | } | |
456 | } | |
457 | ||
458 | /* Make sure that there are no statements after LAST in the constructor | |
459 | body represented by LIST. */ | |
460 | ||
461 | bool | |
462 | check_constexpr_ctor_body (tree last, tree list, bool complain) | |
463 | { | |
9c96033c | 464 | /* C++14 doesn't require a constexpr ctor to have an empty body. */ |
465 | if (cxx_dialect >= cxx14) | |
466 | return true; | |
467 | ||
09b42213 | 468 | bool ok = true; |
469 | if (TREE_CODE (list) == STATEMENT_LIST) | |
470 | { | |
471 | tree_stmt_iterator i = tsi_last (list); | |
472 | for (; !tsi_end_p (i); tsi_prev (&i)) | |
473 | { | |
474 | tree t = tsi_stmt (i); | |
475 | if (t == last) | |
476 | break; | |
477 | if (!check_constexpr_ctor_body_1 (last, t)) | |
478 | { | |
479 | ok = false; | |
480 | break; | |
481 | } | |
482 | } | |
483 | } | |
484 | else if (list != last | |
485 | && !check_constexpr_ctor_body_1 (last, list)) | |
486 | ok = false; | |
487 | if (!ok) | |
488 | { | |
489 | if (complain) | |
490 | error ("constexpr constructor does not have empty body"); | |
491 | DECL_DECLARED_CONSTEXPR_P (current_function_decl) = false; | |
492 | } | |
493 | return ok; | |
494 | } | |
495 | ||
496 | /* V is a vector of constructor elements built up for the base and member | |
497 | initializers of a constructor for TYPE. They need to be in increasing | |
498 | offset order, which they might not be yet if TYPE has a primary base | |
499 | which is not first in the base-clause or a vptr and at least one base | |
500 | all of which are non-primary. */ | |
501 | ||
502 | static vec<constructor_elt, va_gc> * | |
503 | sort_constexpr_mem_initializers (tree type, vec<constructor_elt, va_gc> *v) | |
504 | { | |
505 | tree pri = CLASSTYPE_PRIMARY_BINFO (type); | |
506 | tree field_type; | |
507 | unsigned i; | |
508 | constructor_elt *ce; | |
509 | ||
510 | if (pri) | |
511 | field_type = BINFO_TYPE (pri); | |
512 | else if (TYPE_CONTAINS_VPTR_P (type)) | |
513 | field_type = vtbl_ptr_type_node; | |
514 | else | |
515 | return v; | |
516 | ||
517 | /* Find the element for the primary base or vptr and move it to the | |
518 | beginning of the vec. */ | |
519 | for (i = 0; vec_safe_iterate (v, i, &ce); ++i) | |
520 | if (TREE_TYPE (ce->index) == field_type) | |
521 | break; | |
522 | ||
523 | if (i > 0 && i < vec_safe_length (v)) | |
524 | { | |
525 | vec<constructor_elt, va_gc> &vref = *v; | |
526 | constructor_elt elt = vref[i]; | |
527 | for (; i > 0; --i) | |
528 | vref[i] = vref[i-1]; | |
529 | vref[0] = elt; | |
530 | } | |
531 | ||
532 | return v; | |
533 | } | |
534 | ||
535 | /* Build compile-time evalable representations of member-initializer list | |
536 | for a constexpr constructor. */ | |
537 | ||
538 | static tree | |
539 | build_constexpr_constructor_member_initializers (tree type, tree body) | |
540 | { | |
541 | vec<constructor_elt, va_gc> *vec = NULL; | |
542 | bool ok = true; | |
816919e1 | 543 | while (true) |
544 | switch (TREE_CODE (body)) | |
545 | { | |
546 | case MUST_NOT_THROW_EXPR: | |
547 | case EH_SPEC_BLOCK: | |
548 | body = TREE_OPERAND (body, 0); | |
549 | break; | |
550 | ||
551 | case STATEMENT_LIST: | |
552 | for (tree_stmt_iterator i = tsi_start (body); | |
553 | !tsi_end_p (i); tsi_next (&i)) | |
554 | { | |
555 | body = tsi_stmt (i); | |
556 | if (TREE_CODE (body) == BIND_EXPR) | |
557 | break; | |
558 | } | |
559 | break; | |
560 | ||
561 | case BIND_EXPR: | |
562 | body = BIND_EXPR_BODY (body); | |
563 | goto found; | |
564 | ||
565 | default: | |
566 | gcc_unreachable (); | |
8a36d0ec | 567 | } |
816919e1 | 568 | found: |
09b42213 | 569 | if (TREE_CODE (body) == CLEANUP_POINT_EXPR) |
570 | { | |
571 | body = TREE_OPERAND (body, 0); | |
572 | if (TREE_CODE (body) == EXPR_STMT) | |
573 | body = TREE_OPERAND (body, 0); | |
574 | if (TREE_CODE (body) == INIT_EXPR | |
575 | && (same_type_ignoring_top_level_qualifiers_p | |
576 | (TREE_TYPE (TREE_OPERAND (body, 0)), | |
577 | current_class_type))) | |
578 | { | |
579 | /* Trivial copy. */ | |
580 | return TREE_OPERAND (body, 1); | |
581 | } | |
582 | ok = build_data_member_initialization (body, &vec); | |
583 | } | |
584 | else if (TREE_CODE (body) == STATEMENT_LIST) | |
585 | { | |
586 | tree_stmt_iterator i; | |
587 | for (i = tsi_start (body); !tsi_end_p (i); tsi_next (&i)) | |
588 | { | |
589 | ok = build_data_member_initialization (tsi_stmt (i), &vec); | |
590 | if (!ok) | |
591 | break; | |
592 | } | |
593 | } | |
594 | else if (TREE_CODE (body) == TRY_BLOCK) | |
595 | { | |
596 | error ("body of %<constexpr%> constructor cannot be " | |
597 | "a function-try-block"); | |
598 | return error_mark_node; | |
599 | } | |
600 | else if (EXPR_P (body)) | |
601 | ok = build_data_member_initialization (body, &vec); | |
602 | else | |
603 | gcc_assert (errorcount > 0); | |
604 | if (ok) | |
605 | { | |
606 | if (vec_safe_length (vec) > 0) | |
607 | { | |
608 | /* In a delegating constructor, return the target. */ | |
609 | constructor_elt *ce = &(*vec)[0]; | |
610 | if (ce->index == current_class_ptr) | |
611 | { | |
612 | body = ce->value; | |
613 | vec_free (vec); | |
614 | return body; | |
615 | } | |
616 | } | |
617 | vec = sort_constexpr_mem_initializers (type, vec); | |
618 | return build_constructor (type, vec); | |
619 | } | |
620 | else | |
621 | return error_mark_node; | |
622 | } | |
623 | ||
624 | /* Subroutine of register_constexpr_fundef. BODY is the body of a function | |
625 | declared to be constexpr, or a sub-statement thereof. Returns the | |
626 | return value if suitable, error_mark_node for a statement not allowed in | |
627 | a constexpr function, or NULL_TREE if no return value was found. */ | |
628 | ||
629 | static tree | |
630 | constexpr_fn_retval (tree body) | |
631 | { | |
632 | switch (TREE_CODE (body)) | |
633 | { | |
634 | case STATEMENT_LIST: | |
635 | { | |
636 | tree_stmt_iterator i; | |
637 | tree expr = NULL_TREE; | |
638 | for (i = tsi_start (body); !tsi_end_p (i); tsi_next (&i)) | |
639 | { | |
640 | tree s = constexpr_fn_retval (tsi_stmt (i)); | |
641 | if (s == error_mark_node) | |
642 | return error_mark_node; | |
643 | else if (s == NULL_TREE) | |
644 | /* Keep iterating. */; | |
645 | else if (expr) | |
646 | /* Multiple return statements. */ | |
647 | return error_mark_node; | |
648 | else | |
649 | expr = s; | |
650 | } | |
651 | return expr; | |
652 | } | |
653 | ||
654 | case RETURN_EXPR: | |
655 | return break_out_target_exprs (TREE_OPERAND (body, 0)); | |
656 | ||
657 | case DECL_EXPR: | |
394aed6a | 658 | { |
659 | tree decl = DECL_EXPR_DECL (body); | |
660 | if (TREE_CODE (decl) == USING_DECL | |
661 | /* Accept __func__, __FUNCTION__, and __PRETTY_FUNCTION__. */ | |
662 | || DECL_ARTIFICIAL (decl)) | |
663 | return NULL_TREE; | |
664 | return error_mark_node; | |
665 | } | |
09b42213 | 666 | |
667 | case CLEANUP_POINT_EXPR: | |
668 | return constexpr_fn_retval (TREE_OPERAND (body, 0)); | |
669 | ||
670 | case BIND_EXPR: | |
671 | if (!check_constexpr_bind_expr_vars (body)) | |
672 | return error_mark_node; | |
673 | return constexpr_fn_retval (BIND_EXPR_BODY (body)); | |
674 | ||
675 | case USING_STMT: | |
676 | return NULL_TREE; | |
677 | ||
678 | default: | |
679 | return error_mark_node; | |
680 | } | |
681 | } | |
682 | ||
683 | /* Subroutine of register_constexpr_fundef. BODY is the DECL_SAVED_TREE of | |
684 | FUN; do the necessary transformations to turn it into a single expression | |
685 | that we can store in the hash table. */ | |
686 | ||
687 | static tree | |
688 | massage_constexpr_body (tree fun, tree body) | |
689 | { | |
690 | if (DECL_CONSTRUCTOR_P (fun)) | |
691 | body = build_constexpr_constructor_member_initializers | |
692 | (DECL_CONTEXT (fun), body); | |
9c96033c | 693 | else if (cxx_dialect < cxx14) |
09b42213 | 694 | { |
695 | if (TREE_CODE (body) == EH_SPEC_BLOCK) | |
696 | body = EH_SPEC_STMTS (body); | |
697 | if (TREE_CODE (body) == MUST_NOT_THROW_EXPR) | |
698 | body = TREE_OPERAND (body, 0); | |
699 | body = constexpr_fn_retval (body); | |
700 | } | |
701 | return body; | |
702 | } | |
703 | ||
2f4cab3c | 704 | /* CTYPE is a type constructed from BODY. Return true if some |
705 | bases/fields are uninitialized, and complain if COMPLAIN. */ | |
09b42213 | 706 | |
707 | static bool | |
2f4cab3c | 708 | cx_check_missing_mem_inits (tree ctype, tree body, bool complain) |
09b42213 | 709 | { |
2f4cab3c | 710 | unsigned nelts = 0; |
711 | ||
712 | if (body) | |
713 | { | |
714 | if (TREE_CODE (body) != CONSTRUCTOR) | |
715 | return false; | |
716 | nelts = CONSTRUCTOR_NELTS (body); | |
717 | } | |
718 | tree field = TYPE_FIELDS (ctype); | |
09b42213 | 719 | |
720 | if (TREE_CODE (ctype) == UNION_TYPE) | |
721 | { | |
722 | if (nelts == 0 && next_initializable_field (field)) | |
723 | { | |
724 | if (complain) | |
725 | error ("%<constexpr%> constructor for union %qT must " | |
726 | "initialize exactly one non-static data member", ctype); | |
727 | return true; | |
728 | } | |
729 | return false; | |
730 | } | |
731 | ||
2f4cab3c | 732 | /* Iterate over the CONSTRUCTOR, checking any missing fields don't |
733 | need an explicit initialization. */ | |
734 | bool bad = false; | |
735 | for (unsigned i = 0; i <= nelts; ++i) | |
09b42213 | 736 | { |
2f4cab3c | 737 | tree index = NULL_TREE; |
738 | if (i < nelts) | |
09b42213 | 739 | { |
740 | index = CONSTRUCTOR_ELT (body, i)->index; | |
741 | /* Skip base and vtable inits. */ | |
742 | if (TREE_CODE (index) != FIELD_DECL | |
743 | || DECL_ARTIFICIAL (index)) | |
744 | continue; | |
745 | } | |
2f4cab3c | 746 | |
09b42213 | 747 | for (; field != index; field = DECL_CHAIN (field)) |
748 | { | |
749 | tree ftype; | |
2f4cab3c | 750 | if (TREE_CODE (field) != FIELD_DECL) |
751 | continue; | |
752 | if (DECL_C_BIT_FIELD (field) && !DECL_NAME (field)) | |
09b42213 | 753 | continue; |
2f4cab3c | 754 | if (DECL_ARTIFICIAL (field)) |
755 | continue; | |
756 | if (ANON_AGGR_TYPE_P (TREE_TYPE (field))) | |
757 | { | |
758 | /* Recurse to check the anonummous aggregate member. */ | |
759 | bad |= cx_check_missing_mem_inits | |
760 | (TREE_TYPE (field), NULL_TREE, complain); | |
761 | if (bad && !complain) | |
762 | return true; | |
763 | continue; | |
764 | } | |
09b42213 | 765 | ftype = strip_array_types (TREE_TYPE (field)); |
766 | if (type_has_constexpr_default_constructor (ftype)) | |
767 | { | |
768 | /* It's OK to skip a member with a trivial constexpr ctor. | |
769 | A constexpr ctor that isn't trivial should have been | |
770 | added in by now. */ | |
771 | gcc_checking_assert (!TYPE_HAS_COMPLEX_DFLT (ftype) | |
772 | || errorcount != 0); | |
773 | continue; | |
774 | } | |
775 | if (!complain) | |
776 | return true; | |
859e2c29 | 777 | error ("member %qD must be initialized by mem-initializer " |
778 | "in %<constexpr%> constructor", field); | |
779 | inform (DECL_SOURCE_LOCATION (field), "declared here"); | |
09b42213 | 780 | bad = true; |
781 | } | |
782 | if (field == NULL_TREE) | |
783 | break; | |
2f4cab3c | 784 | |
785 | if (ANON_AGGR_TYPE_P (TREE_TYPE (index))) | |
786 | { | |
787 | /* Check the anonymous aggregate initializer is valid. */ | |
788 | bad |= cx_check_missing_mem_inits | |
789 | (TREE_TYPE (index), CONSTRUCTOR_ELT (body, i)->value, complain); | |
790 | if (bad && !complain) | |
791 | return true; | |
792 | } | |
09b42213 | 793 | field = DECL_CHAIN (field); |
794 | } | |
795 | ||
796 | return bad; | |
797 | } | |
798 | ||
799 | /* We are processing the definition of the constexpr function FUN. | |
800 | Check that its BODY fulfills the propriate requirements and | |
801 | enter it in the constexpr function definition table. | |
802 | For constructor BODY is actually the TREE_LIST of the | |
803 | member-initializer list. */ | |
804 | ||
805 | tree | |
806 | register_constexpr_fundef (tree fun, tree body) | |
807 | { | |
808 | constexpr_fundef entry; | |
809 | constexpr_fundef **slot; | |
810 | ||
811 | if (!is_valid_constexpr_fn (fun, !DECL_GENERATED_P (fun))) | |
812 | return NULL; | |
813 | ||
6a385150 | 814 | tree massaged = massage_constexpr_body (fun, body); |
815 | if (massaged == NULL_TREE || massaged == error_mark_node) | |
09b42213 | 816 | { |
817 | if (!DECL_CONSTRUCTOR_P (fun)) | |
818 | error ("body of constexpr function %qD not a return-statement", fun); | |
819 | return NULL; | |
820 | } | |
821 | ||
6a385150 | 822 | if (!potential_rvalue_constant_expression (massaged)) |
09b42213 | 823 | { |
824 | if (!DECL_GENERATED_P (fun)) | |
6a385150 | 825 | require_potential_rvalue_constant_expression (massaged); |
09b42213 | 826 | return NULL; |
827 | } | |
828 | ||
829 | if (DECL_CONSTRUCTOR_P (fun) | |
2f4cab3c | 830 | && cx_check_missing_mem_inits (DECL_CONTEXT (fun), |
831 | massaged, !DECL_GENERATED_P (fun))) | |
09b42213 | 832 | return NULL; |
833 | ||
834 | /* Create the constexpr function table if necessary. */ | |
835 | if (constexpr_fundef_table == NULL) | |
836 | constexpr_fundef_table | |
837 | = hash_table<constexpr_fundef_hasher>::create_ggc (101); | |
838 | ||
839 | entry.decl = fun; | |
840 | entry.body = body; | |
841 | slot = constexpr_fundef_table->find_slot (&entry, INSERT); | |
842 | ||
843 | gcc_assert (*slot == NULL); | |
844 | *slot = ggc_alloc<constexpr_fundef> (); | |
845 | **slot = entry; | |
846 | ||
847 | return fun; | |
848 | } | |
849 | ||
850 | /* FUN is a non-constexpr function called in a context that requires a | |
851 | constant expression. If it comes from a constexpr template, explain why | |
852 | the instantiation isn't constexpr. */ | |
853 | ||
854 | void | |
855 | explain_invalid_constexpr_fn (tree fun) | |
856 | { | |
857 | static hash_set<tree> *diagnosed; | |
858 | tree body; | |
859 | location_t save_loc; | |
33603066 | 860 | /* Only diagnose defaulted functions, lambdas, or instantiations. */ |
09b42213 | 861 | if (!DECL_DEFAULTED_FN (fun) |
33603066 | 862 | && !LAMBDA_TYPE_P (CP_DECL_CONTEXT (fun)) |
09b42213 | 863 | && !is_instantiation_of_constexpr (fun)) |
864 | return; | |
865 | if (diagnosed == NULL) | |
866 | diagnosed = new hash_set<tree>; | |
867 | if (diagnosed->add (fun)) | |
868 | /* Already explained. */ | |
869 | return; | |
870 | ||
871 | save_loc = input_location; | |
33603066 | 872 | if (!lambda_static_thunk_p (fun)) |
873 | { | |
874 | /* Diagnostics should completely ignore the static thunk, so leave | |
875 | input_location set to our caller's location. */ | |
876 | input_location = DECL_SOURCE_LOCATION (fun); | |
877 | inform (input_location, | |
878 | "%qD is not usable as a constexpr function because:", fun); | |
879 | } | |
09b42213 | 880 | /* First check the declaration. */ |
881 | if (is_valid_constexpr_fn (fun, true)) | |
882 | { | |
883 | /* Then if it's OK, the body. */ | |
33603066 | 884 | if (!DECL_DECLARED_CONSTEXPR_P (fun) |
885 | && !LAMBDA_TYPE_P (CP_DECL_CONTEXT (fun))) | |
09b42213 | 886 | explain_implicit_non_constexpr (fun); |
887 | else | |
888 | { | |
889 | body = massage_constexpr_body (fun, DECL_SAVED_TREE (fun)); | |
890 | require_potential_rvalue_constant_expression (body); | |
891 | if (DECL_CONSTRUCTOR_P (fun)) | |
2f4cab3c | 892 | cx_check_missing_mem_inits (DECL_CONTEXT (fun), body, true); |
09b42213 | 893 | } |
894 | } | |
895 | input_location = save_loc; | |
896 | } | |
897 | ||
898 | /* Objects of this type represent calls to constexpr functions | |
899 | along with the bindings of parameters to their arguments, for | |
900 | the purpose of compile time evaluation. */ | |
901 | ||
902 | struct GTY((for_user)) constexpr_call { | |
903 | /* Description of the constexpr function definition. */ | |
904 | constexpr_fundef *fundef; | |
905 | /* Parameter bindings environment. A TREE_LIST where each TREE_PURPOSE | |
906 | is a parameter _DECL and the TREE_VALUE is the value of the parameter. | |
907 | Note: This arrangement is made to accommodate the use of | |
908 | iterative_hash_template_arg (see pt.c). If you change this | |
909 | representation, also change the hash calculation in | |
910 | cxx_eval_call_expression. */ | |
911 | tree bindings; | |
912 | /* Result of the call. | |
913 | NULL means the call is being evaluated. | |
914 | error_mark_node means that the evaluation was erroneous; | |
915 | otherwise, the actuall value of the call. */ | |
916 | tree result; | |
917 | /* The hash of this call; we remember it here to avoid having to | |
918 | recalculate it when expanding the hash table. */ | |
919 | hashval_t hash; | |
920 | }; | |
921 | ||
b594087e | 922 | struct constexpr_call_hasher : ggc_ptr_hash<constexpr_call> |
09b42213 | 923 | { |
924 | static hashval_t hash (constexpr_call *); | |
925 | static bool equal (constexpr_call *, constexpr_call *); | |
cf72f34d | 926 | }; |
927 | ||
2a2770c6 | 928 | enum constexpr_switch_state { |
929 | /* Used when processing a switch for the first time by cxx_eval_switch_expr | |
930 | and default: label for that switch has not been seen yet. */ | |
931 | css_default_not_seen, | |
932 | /* Used when processing a switch for the first time by cxx_eval_switch_expr | |
933 | and default: label for that switch has been seen already. */ | |
934 | css_default_seen, | |
935 | /* Used when processing a switch for the second time by | |
936 | cxx_eval_switch_expr, where default: label should match. */ | |
937 | css_default_processing | |
938 | }; | |
939 | ||
cf72f34d | 940 | /* The constexpr expansion context. CALL is the current function |
941 | expansion, CTOR is the current aggregate initializer, OBJECT is the | |
942 | object being initialized by CTOR, either a VAR_DECL or a _REF. VALUES | |
943 | is a map of values of variables initialized within the expression. */ | |
944 | ||
945 | struct constexpr_ctx { | |
f9885b8a | 946 | /* The innermost call we're evaluating. */ |
cf72f34d | 947 | constexpr_call *call; |
f9885b8a | 948 | /* Values for any temporaries or local variables within the |
949 | constant-expression. */ | |
cf72f34d | 950 | hash_map<tree,tree> *values; |
2631cb67 | 951 | /* SAVE_EXPRs that we've seen within the current LOOP_EXPR. NULL if we |
952 | aren't inside a loop. */ | |
953 | hash_set<tree> *save_exprs; | |
f9885b8a | 954 | /* The CONSTRUCTOR we're currently building up for an aggregate |
955 | initializer. */ | |
cf72f34d | 956 | tree ctor; |
f9885b8a | 957 | /* The object we're building the CONSTRUCTOR for. */ |
cf72f34d | 958 | tree object; |
2a2770c6 | 959 | /* If inside SWITCH_EXPR. */ |
960 | constexpr_switch_state *css_state; | |
f9885b8a | 961 | /* Whether we should error on a non-constant expression or fail quietly. */ |
f83e6885 | 962 | bool quiet; |
f9885b8a | 963 | /* Whether we are strictly conforming to constant expression rules or |
964 | trying harder to get a constant value. */ | |
2055d27a | 965 | bool strict; |
cf72f34d | 966 | }; |
09b42213 | 967 | |
968 | /* A table of all constexpr calls that have been evaluated by the | |
969 | compiler in this translation unit. */ | |
970 | ||
a050099a | 971 | static GTY (()) hash_table<constexpr_call_hasher> *constexpr_call_table; |
09b42213 | 972 | |
cf72f34d | 973 | static tree cxx_eval_constant_expression (const constexpr_ctx *, tree, |
b2a43197 | 974 | bool, bool *, bool *, tree * = NULL); |
09b42213 | 975 | |
976 | /* Compute a hash value for a constexpr call representation. */ | |
977 | ||
978 | inline hashval_t | |
979 | constexpr_call_hasher::hash (constexpr_call *info) | |
980 | { | |
981 | return info->hash; | |
982 | } | |
983 | ||
984 | /* Return true if the objects pointed to by P and Q represent calls | |
985 | to the same constexpr function with the same arguments. | |
986 | Otherwise, return false. */ | |
987 | ||
988 | bool | |
989 | constexpr_call_hasher::equal (constexpr_call *lhs, constexpr_call *rhs) | |
990 | { | |
991 | tree lhs_bindings; | |
992 | tree rhs_bindings; | |
993 | if (lhs == rhs) | |
994 | return 1; | |
995 | if (!constexpr_fundef_hasher::equal (lhs->fundef, rhs->fundef)) | |
996 | return 0; | |
997 | lhs_bindings = lhs->bindings; | |
998 | rhs_bindings = rhs->bindings; | |
999 | while (lhs_bindings != NULL && rhs_bindings != NULL) | |
1000 | { | |
1001 | tree lhs_arg = TREE_VALUE (lhs_bindings); | |
1002 | tree rhs_arg = TREE_VALUE (rhs_bindings); | |
1003 | gcc_assert (TREE_TYPE (lhs_arg) == TREE_TYPE (rhs_arg)); | |
1004 | if (!cp_tree_equal (lhs_arg, rhs_arg)) | |
1005 | return 0; | |
1006 | lhs_bindings = TREE_CHAIN (lhs_bindings); | |
1007 | rhs_bindings = TREE_CHAIN (rhs_bindings); | |
1008 | } | |
1009 | return lhs_bindings == rhs_bindings; | |
1010 | } | |
1011 | ||
1012 | /* Initialize the constexpr call table, if needed. */ | |
1013 | ||
1014 | static void | |
1015 | maybe_initialize_constexpr_call_table (void) | |
1016 | { | |
1017 | if (constexpr_call_table == NULL) | |
1018 | constexpr_call_table = hash_table<constexpr_call_hasher>::create_ggc (101); | |
1019 | } | |
1020 | ||
4f7ebe46 | 1021 | /* During constexpr CALL_EXPR evaluation, to avoid issues with sharing when |
1022 | a function happens to get called recursively, we unshare the callee | |
1023 | function's body and evaluate this unshared copy instead of evaluating the | |
1024 | original body. | |
1025 | ||
1026 | FUNDEF_COPIES_TABLE is a per-function freelist of these unshared function | |
1027 | copies. The underlying data structure of FUNDEF_COPIES_TABLE is a hash_map | |
a050099a | 1028 | that's keyed off of the original FUNCTION_DECL and whose value is a |
1029 | TREE_LIST of this function's unused copies awaiting reuse. | |
4f7ebe46 | 1030 | |
a050099a | 1031 | This is not GC-deletable to avoid GC affecting UID generation. */ |
4f7ebe46 | 1032 | |
a050099a | 1033 | static GTY(()) hash_map<tree, tree> *fundef_copies_table; |
4f7ebe46 | 1034 | |
1035 | /* Initialize FUNDEF_COPIES_TABLE if it's not initialized. */ | |
1036 | ||
1037 | static void | |
1038 | maybe_initialize_fundef_copies_table () | |
1039 | { | |
a050099a | 1040 | if (fundef_copies_table == NULL) |
1041 | fundef_copies_table = hash_map<tree,tree>::create_ggc (101); | |
4f7ebe46 | 1042 | } |
1043 | ||
1044 | /* Reuse a copy or create a new unshared copy of the function FUN. | |
886d5463 | 1045 | Return this copy. We use a TREE_LIST whose PURPOSE is body, VALUE |
1046 | is parms, TYPE is result. */ | |
4f7ebe46 | 1047 | |
a050099a | 1048 | static tree |
4f7ebe46 | 1049 | get_fundef_copy (tree fun) |
1050 | { | |
1051 | maybe_initialize_fundef_copies_table (); | |
1052 | ||
a050099a | 1053 | tree copy; |
886d5463 | 1054 | bool existed; |
1055 | tree *slot = &fundef_copies_table->get_or_insert (fun, &existed); | |
1056 | ||
1057 | if (!existed) | |
4f7ebe46 | 1058 | { |
886d5463 | 1059 | /* There is no cached function available, or in use. We can use |
1060 | the function directly. That the slot is now created records | |
1061 | that this function is now in use. */ | |
1062 | copy = build_tree_list (DECL_SAVED_TREE (fun), DECL_ARGUMENTS (fun)); | |
1063 | TREE_TYPE (copy) = DECL_RESULT (fun); | |
1064 | } | |
1065 | else if (*slot == NULL_TREE) | |
1066 | { | |
1067 | /* We've already used the function itself, so make a copy. */ | |
a050099a | 1068 | copy = build_tree_list (NULL, NULL); |
a050099a | 1069 | TREE_PURPOSE (copy) = copy_fn (fun, TREE_VALUE (copy), TREE_TYPE (copy)); |
4f7ebe46 | 1070 | } |
1071 | else | |
1072 | { | |
886d5463 | 1073 | /* We have a cached function available. */ |
4f7ebe46 | 1074 | copy = *slot; |
a050099a | 1075 | *slot = TREE_CHAIN (copy); |
4f7ebe46 | 1076 | } |
1077 | ||
1078 | return copy; | |
1079 | } | |
1080 | ||
886d5463 | 1081 | /* Save the copy COPY of function FUN for later reuse by |
1082 | get_fundef_copy(). By construction, there will always be an entry | |
1083 | to find. */ | |
4f7ebe46 | 1084 | |
1085 | static void | |
a050099a | 1086 | save_fundef_copy (tree fun, tree copy) |
4f7ebe46 | 1087 | { |
886d5463 | 1088 | tree *slot = fundef_copies_table->get (fun); |
a050099a | 1089 | TREE_CHAIN (copy) = *slot; |
4f7ebe46 | 1090 | *slot = copy; |
1091 | } | |
1092 | ||
09b42213 | 1093 | /* We have an expression tree T that represents a call, either CALL_EXPR |
1094 | or AGGR_INIT_EXPR. If the call is lexically to a named function, | |
1095 | retrun the _DECL for that function. */ | |
1096 | ||
1097 | static tree | |
1098 | get_function_named_in_call (tree t) | |
1099 | { | |
3ae3cb42 | 1100 | tree fun = cp_get_callee (t); |
9c96033c | 1101 | if (fun && TREE_CODE (fun) == ADDR_EXPR |
09b42213 | 1102 | && TREE_CODE (TREE_OPERAND (fun, 0)) == FUNCTION_DECL) |
1103 | fun = TREE_OPERAND (fun, 0); | |
1104 | return fun; | |
1105 | } | |
1106 | ||
1107 | /* We have an expression tree T that represents a call, either CALL_EXPR | |
1108 | or AGGR_INIT_EXPR. Return the Nth argument. */ | |
1109 | ||
1110 | static inline tree | |
1111 | get_nth_callarg (tree t, int n) | |
1112 | { | |
1113 | switch (TREE_CODE (t)) | |
1114 | { | |
1115 | case CALL_EXPR: | |
1116 | return CALL_EXPR_ARG (t, n); | |
1117 | ||
1118 | case AGGR_INIT_EXPR: | |
1119 | return AGGR_INIT_EXPR_ARG (t, n); | |
1120 | ||
1121 | default: | |
1122 | gcc_unreachable (); | |
1123 | return NULL; | |
1124 | } | |
1125 | } | |
1126 | ||
09b42213 | 1127 | /* Attempt to evaluate T which represents a call to a builtin function. |
1128 | We assume here that all builtin functions evaluate to scalar types | |
1129 | represented by _CST nodes. */ | |
1130 | ||
1131 | static tree | |
f1c6af10 | 1132 | cxx_eval_builtin_function_call (const constexpr_ctx *ctx, tree t, tree fun, |
1227ba74 | 1133 | bool lval, |
09b42213 | 1134 | bool *non_constant_p, bool *overflow_p) |
1135 | { | |
1136 | const int nargs = call_expr_nargs (t); | |
1137 | tree *args = (tree *) alloca (nargs * sizeof (tree)); | |
1138 | tree new_call; | |
1139 | int i; | |
f1c6af10 | 1140 | |
1141 | /* Don't fold __builtin_constant_p within a constexpr function. */ | |
efe6a40a | 1142 | bool bi_const_p = (DECL_FUNCTION_CODE (fun) == BUILT_IN_CONSTANT_P); |
1143 | ||
1144 | if (bi_const_p | |
f1c6af10 | 1145 | && current_function_decl |
1146 | && DECL_DECLARED_CONSTEXPR_P (current_function_decl)) | |
09b42213 | 1147 | { |
f1c6af10 | 1148 | *non_constant_p = true; |
1149 | return t; | |
09b42213 | 1150 | } |
f1c6af10 | 1151 | |
1152 | /* Be permissive for arguments to built-ins; __builtin_constant_p should | |
1153 | return constant false for a non-constant argument. */ | |
1154 | constexpr_ctx new_ctx = *ctx; | |
1155 | new_ctx.quiet = true; | |
1156 | bool dummy1 = false, dummy2 = false; | |
1157 | for (i = 0; i < nargs; ++i) | |
efe6a40a | 1158 | { |
1159 | args[i] = cxx_eval_constant_expression (&new_ctx, CALL_EXPR_ARG (t, i), | |
051eb924 | 1160 | false, &dummy1, &dummy2); |
efe6a40a | 1161 | if (bi_const_p) |
1162 | /* For __built_in_constant_p, fold all expressions with constant values | |
1163 | even if they aren't C++ constant-expressions. */ | |
1164 | args[i] = cp_fully_fold (args[i]); | |
1165 | } | |
f1c6af10 | 1166 | |
1167 | bool save_ffbcp = force_folding_builtin_constant_p; | |
1168 | force_folding_builtin_constant_p = true; | |
051eb924 | 1169 | new_call = fold_builtin_call_array (EXPR_LOCATION (t), TREE_TYPE (t), |
1170 | CALL_EXPR_FN (t), nargs, args); | |
f1c6af10 | 1171 | force_folding_builtin_constant_p = save_ffbcp; |
051eb924 | 1172 | if (new_call == NULL) |
1173 | { | |
1174 | if (!*non_constant_p && !ctx->quiet) | |
1175 | { | |
1176 | new_call = build_call_array_loc (EXPR_LOCATION (t), TREE_TYPE (t), | |
1177 | CALL_EXPR_FN (t), nargs, args); | |
1178 | error ("%q+E is not a constant expression", new_call); | |
1179 | } | |
1180 | *non_constant_p = true; | |
1181 | return t; | |
1182 | } | |
1183 | ||
1184 | if (!potential_constant_expression (new_call)) | |
1185 | { | |
1186 | if (!*non_constant_p && !ctx->quiet) | |
1187 | error ("%q+E is not a constant expression", new_call); | |
1188 | *non_constant_p = true; | |
1189 | return t; | |
1190 | } | |
1191 | ||
1192 | return cxx_eval_constant_expression (&new_ctx, new_call, lval, | |
1193 | non_constant_p, overflow_p); | |
09b42213 | 1194 | } |
1195 | ||
1196 | /* TEMP is the constant value of a temporary object of type TYPE. Adjust | |
1197 | the type of the value to match. */ | |
1198 | ||
1199 | static tree | |
1200 | adjust_temp_type (tree type, tree temp) | |
1201 | { | |
1202 | if (TREE_TYPE (temp) == type) | |
1203 | return temp; | |
1204 | /* Avoid wrapping an aggregate value in a NOP_EXPR. */ | |
1205 | if (TREE_CODE (temp) == CONSTRUCTOR) | |
1206 | return build_constructor (type, CONSTRUCTOR_ELTS (temp)); | |
1207 | gcc_assert (scalarish_type_p (type)); | |
1208 | return cp_fold_convert (type, temp); | |
1209 | } | |
1210 | ||
e283bb4f | 1211 | /* Callback for walk_tree used by unshare_constructor. */ |
1212 | ||
1213 | static tree | |
1214 | find_constructor (tree *tp, int *walk_subtrees, void *) | |
1215 | { | |
1216 | if (TYPE_P (*tp)) | |
1217 | *walk_subtrees = 0; | |
1218 | if (TREE_CODE (*tp) == CONSTRUCTOR) | |
1219 | return *tp; | |
1220 | return NULL_TREE; | |
1221 | } | |
1222 | ||
1223 | /* If T is a CONSTRUCTOR or an expression that has a CONSTRUCTOR node as a | |
1224 | subexpression, return an unshared copy of T. Otherwise return T. */ | |
1225 | ||
1226 | static tree | |
1227 | unshare_constructor (tree t) | |
1228 | { | |
1229 | tree ctor = walk_tree (&t, find_constructor, NULL, NULL); | |
1230 | if (ctor != NULL_TREE) | |
1231 | return unshare_expr (t); | |
1232 | return t; | |
1233 | } | |
1234 | ||
09b42213 | 1235 | /* Subroutine of cxx_eval_call_expression. |
1236 | We are processing a call expression (either CALL_EXPR or | |
cf72f34d | 1237 | AGGR_INIT_EXPR) in the context of CTX. Evaluate |
09b42213 | 1238 | all arguments and bind their values to correspondings |
1239 | parameters, making up the NEW_CALL context. */ | |
1240 | ||
1241 | static void | |
cf72f34d | 1242 | cxx_bind_parameters_in_call (const constexpr_ctx *ctx, tree t, |
09b42213 | 1243 | constexpr_call *new_call, |
c8f6aeb1 | 1244 | bool *non_constant_p, bool *overflow_p, |
1245 | bool *non_constant_args) | |
09b42213 | 1246 | { |
1247 | const int nargs = call_expr_nargs (t); | |
1248 | tree fun = new_call->fundef->decl; | |
1249 | tree parms = DECL_ARGUMENTS (fun); | |
1250 | int i; | |
9c96033c | 1251 | tree *p = &new_call->bindings; |
09b42213 | 1252 | for (i = 0; i < nargs; ++i) |
1253 | { | |
1254 | tree x, arg; | |
1255 | tree type = parms ? TREE_TYPE (parms) : void_type_node; | |
09b42213 | 1256 | x = get_nth_callarg (t, i); |
cf72f34d | 1257 | /* For member function, the first argument is a pointer to the implied |
1258 | object. For a constructor, it might still be a dummy object, in | |
9c96033c | 1259 | which case we get the real argument from ctx. */ |
cf72f34d | 1260 | if (i == 0 && DECL_CONSTRUCTOR_P (fun) |
1261 | && is_dummy_object (x)) | |
1262 | { | |
1263 | x = ctx->object; | |
cf72f34d | 1264 | x = cp_build_addr_expr (x, tf_warning_or_error); |
1265 | } | |
1227ba74 | 1266 | bool lval = false; |
1227ba74 | 1267 | arg = cxx_eval_constant_expression (ctx, x, lval, |
b2a43197 | 1268 | non_constant_p, overflow_p); |
09b42213 | 1269 | /* Don't VERIFY_CONSTANT here. */ |
f83e6885 | 1270 | if (*non_constant_p && ctx->quiet) |
09b42213 | 1271 | return; |
1272 | /* Just discard ellipsis args after checking their constantitude. */ | |
1273 | if (!parms) | |
1274 | continue; | |
2ba934c7 | 1275 | |
1276 | if (!*non_constant_p) | |
1277 | { | |
1278 | /* Make sure the binding has the same type as the parm. But | |
1279 | only for constant args. */ | |
1280 | if (TREE_CODE (type) != REFERENCE_TYPE) | |
1281 | arg = adjust_temp_type (type, arg); | |
1282 | if (!TREE_CONSTANT (arg)) | |
1283 | *non_constant_args = true; | |
1284 | *p = build_tree_list (parms, arg); | |
1285 | p = &TREE_CHAIN (*p); | |
1286 | } | |
09b42213 | 1287 | parms = TREE_CHAIN (parms); |
1288 | } | |
1289 | } | |
1290 | ||
1291 | /* Variables and functions to manage constexpr call expansion context. | |
1292 | These do not need to be marked for PCH or GC. */ | |
1293 | ||
1294 | /* FIXME remember and print actual constant arguments. */ | |
16fb756f | 1295 | static vec<tree> call_stack; |
09b42213 | 1296 | static int call_stack_tick; |
1297 | static int last_cx_error_tick; | |
1298 | ||
1299 | static bool | |
1300 | push_cx_call_context (tree call) | |
1301 | { | |
1302 | ++call_stack_tick; | |
1303 | if (!EXPR_HAS_LOCATION (call)) | |
1304 | SET_EXPR_LOCATION (call, input_location); | |
1305 | call_stack.safe_push (call); | |
1306 | if (call_stack.length () > (unsigned) max_constexpr_depth) | |
1307 | return false; | |
1308 | return true; | |
1309 | } | |
1310 | ||
1311 | static void | |
1312 | pop_cx_call_context (void) | |
1313 | { | |
1314 | ++call_stack_tick; | |
1315 | call_stack.pop (); | |
1316 | } | |
1317 | ||
1318 | vec<tree> | |
1319 | cx_error_context (void) | |
1320 | { | |
1321 | vec<tree> r = vNULL; | |
1322 | if (call_stack_tick != last_cx_error_tick | |
1323 | && !call_stack.is_empty ()) | |
1324 | r = call_stack; | |
1325 | last_cx_error_tick = call_stack_tick; | |
1326 | return r; | |
1327 | } | |
1328 | ||
732905bb | 1329 | /* Evaluate a call T to a GCC internal function when possible and return |
1330 | the evaluated result or, under the control of CTX, give an error, set | |
1331 | NON_CONSTANT_P, and return the unevaluated call T otherwise. */ | |
1332 | ||
1333 | static tree | |
1334 | cxx_eval_internal_function (const constexpr_ctx *ctx, tree t, | |
1335 | bool lval, | |
1336 | bool *non_constant_p, bool *overflow_p) | |
1337 | { | |
1338 | enum tree_code opcode = ERROR_MARK; | |
1339 | ||
1340 | switch (CALL_EXPR_IFN (t)) | |
1341 | { | |
1342 | case IFN_UBSAN_NULL: | |
1343 | case IFN_UBSAN_BOUNDS: | |
1344 | case IFN_UBSAN_VPTR: | |
3c77f69c | 1345 | case IFN_FALLTHROUGH: |
732905bb | 1346 | return void_node; |
1347 | ||
1348 | case IFN_ADD_OVERFLOW: | |
1349 | opcode = PLUS_EXPR; | |
1350 | break; | |
1351 | case IFN_SUB_OVERFLOW: | |
1352 | opcode = MINUS_EXPR; | |
1353 | break; | |
1354 | case IFN_MUL_OVERFLOW: | |
1355 | opcode = MULT_EXPR; | |
1356 | break; | |
1357 | ||
6e1b2ffb | 1358 | case IFN_LAUNDER: |
1359 | return cxx_eval_constant_expression (ctx, CALL_EXPR_ARG (t, 0), | |
1360 | false, non_constant_p, overflow_p); | |
1361 | ||
732905bb | 1362 | default: |
1363 | if (!ctx->quiet) | |
1364 | error_at (EXPR_LOC_OR_LOC (t, input_location), | |
1365 | "call to internal function %qE", t); | |
1366 | *non_constant_p = true; | |
1367 | return t; | |
1368 | } | |
1369 | ||
1370 | /* Evaluate constant arguments using OPCODE and return a complex | |
1371 | number containing the result and the overflow bit. */ | |
1372 | tree arg0 = cxx_eval_constant_expression (ctx, CALL_EXPR_ARG (t, 0), lval, | |
1373 | non_constant_p, overflow_p); | |
1374 | tree arg1 = cxx_eval_constant_expression (ctx, CALL_EXPR_ARG (t, 1), lval, | |
1375 | non_constant_p, overflow_p); | |
1376 | ||
1377 | if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST) | |
1378 | { | |
1379 | location_t loc = EXPR_LOC_OR_LOC (t, input_location); | |
1380 | tree type = TREE_TYPE (TREE_TYPE (t)); | |
1381 | tree result = fold_binary_loc (loc, opcode, type, | |
1382 | fold_convert_loc (loc, type, arg0), | |
1383 | fold_convert_loc (loc, type, arg1)); | |
1384 | tree ovf | |
1385 | = build_int_cst (type, arith_overflowed_p (opcode, type, arg0, arg1)); | |
1386 | /* Reset TREE_OVERFLOW to avoid warnings for the overflow. */ | |
1387 | if (TREE_OVERFLOW (result)) | |
1388 | TREE_OVERFLOW (result) = 0; | |
1389 | ||
1390 | return build_complex (TREE_TYPE (t), result, ovf); | |
1391 | } | |
1392 | ||
1393 | *non_constant_p = true; | |
1394 | return t; | |
1395 | } | |
1396 | ||
09b42213 | 1397 | /* Subroutine of cxx_eval_constant_expression. |
1398 | Evaluate the call expression tree T in the context of OLD_CALL expression | |
1399 | evaluation. */ | |
1400 | ||
1401 | static tree | |
cf72f34d | 1402 | cxx_eval_call_expression (const constexpr_ctx *ctx, tree t, |
1227ba74 | 1403 | bool lval, |
09b42213 | 1404 | bool *non_constant_p, bool *overflow_p) |
1405 | { | |
1406 | location_t loc = EXPR_LOC_OR_LOC (t, input_location); | |
1407 | tree fun = get_function_named_in_call (t); | |
09b42213 | 1408 | constexpr_call new_call = { NULL, NULL, NULL, 0 }; |
09b42213 | 1409 | bool depth_ok; |
1410 | ||
6b71bdb4 | 1411 | if (fun == NULL_TREE) |
732905bb | 1412 | return cxx_eval_internal_function (ctx, t, lval, |
1413 | non_constant_p, overflow_p); | |
6b71bdb4 | 1414 | |
09b42213 | 1415 | if (TREE_CODE (fun) != FUNCTION_DECL) |
1416 | { | |
1417 | /* Might be a constexpr function pointer. */ | |
f83e6885 | 1418 | fun = cxx_eval_constant_expression (ctx, fun, |
1227ba74 | 1419 | /*lval*/false, non_constant_p, |
b2a43197 | 1420 | overflow_p); |
09b42213 | 1421 | STRIP_NOPS (fun); |
1422 | if (TREE_CODE (fun) == ADDR_EXPR) | |
1423 | fun = TREE_OPERAND (fun, 0); | |
1424 | } | |
1425 | if (TREE_CODE (fun) != FUNCTION_DECL) | |
1426 | { | |
f83e6885 | 1427 | if (!ctx->quiet && !*non_constant_p) |
09b42213 | 1428 | error_at (loc, "expression %qE does not designate a constexpr " |
1429 | "function", fun); | |
1430 | *non_constant_p = true; | |
1431 | return t; | |
1432 | } | |
1433 | if (DECL_CLONED_FUNCTION_P (fun)) | |
1434 | fun = DECL_CLONED_FUNCTION (fun); | |
6b71bdb4 | 1435 | |
1436 | if (is_ubsan_builtin_p (fun)) | |
1437 | return void_node; | |
1438 | ||
09b42213 | 1439 | if (is_builtin_fn (fun)) |
f1c6af10 | 1440 | return cxx_eval_builtin_function_call (ctx, t, fun, |
1227ba74 | 1441 | lval, non_constant_p, overflow_p); |
09b42213 | 1442 | if (!DECL_DECLARED_CONSTEXPR_P (fun)) |
1443 | { | |
f83e6885 | 1444 | if (!ctx->quiet) |
09b42213 | 1445 | { |
1446 | error_at (loc, "call to non-constexpr function %qD", fun); | |
1447 | explain_invalid_constexpr_fn (fun); | |
1448 | } | |
1449 | *non_constant_p = true; | |
1450 | return t; | |
1451 | } | |
1452 | ||
9ebe2ea3 | 1453 | constexpr_ctx new_ctx = *ctx; |
1454 | if (DECL_CONSTRUCTOR_P (fun) && !ctx->object | |
1455 | && TREE_CODE (t) == AGGR_INIT_EXPR) | |
1456 | { | |
1457 | /* We want to have an initialization target for an AGGR_INIT_EXPR. | |
1458 | If we don't already have one in CTX, use the AGGR_INIT_EXPR_SLOT. */ | |
1459 | new_ctx.object = AGGR_INIT_EXPR_SLOT (t); | |
1460 | tree ctor = new_ctx.ctor = build_constructor (DECL_CONTEXT (fun), NULL); | |
1461 | CONSTRUCTOR_NO_IMPLICIT_ZERO (ctor) = true; | |
1462 | ctx->values->put (new_ctx.object, ctor); | |
1463 | ctx = &new_ctx; | |
1464 | } | |
1465 | ||
09b42213 | 1466 | /* Shortcut trivial constructor/op=. */ |
1467 | if (trivial_fn_p (fun)) | |
1468 | { | |
9ebe2ea3 | 1469 | tree init = NULL_TREE; |
09b42213 | 1470 | if (call_expr_nargs (t) == 2) |
9ebe2ea3 | 1471 | init = convert_from_reference (get_nth_callarg (t, 1)); |
09b42213 | 1472 | else if (TREE_CODE (t) == AGGR_INIT_EXPR |
1473 | && AGGR_INIT_ZERO_FIRST (t)) | |
9ebe2ea3 | 1474 | init = build_zero_init (DECL_CONTEXT (fun), NULL_TREE, false); |
1475 | if (init) | |
1476 | { | |
1477 | tree op = get_nth_callarg (t, 0); | |
1478 | if (is_dummy_object (op)) | |
1479 | op = ctx->object; | |
1480 | else | |
1481 | op = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (op)), op); | |
1482 | tree set = build2 (MODIFY_EXPR, TREE_TYPE (op), op, init); | |
0ce12360 | 1483 | new_ctx.call = &new_call; |
1484 | return cxx_eval_constant_expression (&new_ctx, set, lval, | |
9ebe2ea3 | 1485 | non_constant_p, overflow_p); |
1486 | } | |
09b42213 | 1487 | } |
1488 | ||
8afcf831 | 1489 | /* We can't defer instantiating the function any longer. */ |
1490 | if (!DECL_INITIAL (fun) | |
1491 | && DECL_TEMPLOID_INSTANTIATION (fun)) | |
1492 | { | |
31db86df | 1493 | location_t save_loc = input_location; |
1494 | input_location = loc; | |
8afcf831 | 1495 | ++function_depth; |
1496 | instantiate_decl (fun, /*defer_ok*/false, /*expl_inst*/false); | |
1497 | --function_depth; | |
31db86df | 1498 | input_location = save_loc; |
8afcf831 | 1499 | } |
1500 | ||
09b42213 | 1501 | /* If in direct recursive call, optimize definition search. */ |
0ce12360 | 1502 | if (ctx && ctx->call && ctx->call->fundef && ctx->call->fundef->decl == fun) |
cf72f34d | 1503 | new_call.fundef = ctx->call->fundef; |
09b42213 | 1504 | else |
1505 | { | |
1506 | new_call.fundef = retrieve_constexpr_fundef (fun); | |
d2a9b1c1 | 1507 | if (new_call.fundef == NULL || new_call.fundef->body == NULL |
1508 | || fun == current_function_decl) | |
09b42213 | 1509 | { |
f83e6885 | 1510 | if (!ctx->quiet) |
09b42213 | 1511 | { |
d2a9b1c1 | 1512 | /* We need to check for current_function_decl here in case we're |
1513 | being called during cp_fold_function, because at that point | |
1514 | DECL_INITIAL is set properly and we have a fundef but we | |
1515 | haven't lowered invisirefs yet (c++/70344). */ | |
1516 | if (DECL_INITIAL (fun) == error_mark_node | |
1517 | || fun == current_function_decl) | |
a0efa758 | 1518 | error_at (loc, "%qD called in a constant expression before its " |
1519 | "definition is complete", fun); | |
1520 | else if (DECL_INITIAL (fun)) | |
09b42213 | 1521 | { |
33603066 | 1522 | /* The definition of fun was somehow unsuitable. But pretend |
1523 | that lambda static thunks don't exist. */ | |
1524 | if (!lambda_static_thunk_p (fun)) | |
1525 | error_at (loc, "%qD called in a constant expression", fun); | |
09b42213 | 1526 | explain_invalid_constexpr_fn (fun); |
1527 | } | |
1528 | else | |
1529 | error_at (loc, "%qD used before its definition", fun); | |
1530 | } | |
1531 | *non_constant_p = true; | |
1532 | return t; | |
1533 | } | |
1534 | } | |
9c96033c | 1535 | |
c8f6aeb1 | 1536 | bool non_constant_args = false; |
cf72f34d | 1537 | cxx_bind_parameters_in_call (ctx, t, &new_call, |
c8f6aeb1 | 1538 | non_constant_p, overflow_p, &non_constant_args); |
09b42213 | 1539 | if (*non_constant_p) |
1540 | return t; | |
1541 | ||
1542 | depth_ok = push_cx_call_context (t); | |
1543 | ||
c8f6aeb1 | 1544 | tree result = NULL_TREE; |
09b42213 | 1545 | |
c8f6aeb1 | 1546 | constexpr_call *entry = NULL; |
37715b0f | 1547 | if (depth_ok && !non_constant_args) |
09b42213 | 1548 | { |
c8f6aeb1 | 1549 | new_call.hash = iterative_hash_template_arg |
1550 | (new_call.bindings, constexpr_fundef_hasher::hash (new_call.fundef)); | |
1551 | ||
1552 | /* If we have seen this call before, we are done. */ | |
1553 | maybe_initialize_constexpr_call_table (); | |
1554 | constexpr_call **slot | |
1555 | = constexpr_call_table->find_slot (&new_call, INSERT); | |
1556 | entry = *slot; | |
1557 | if (entry == NULL) | |
1558 | { | |
1559 | /* We need to keep a pointer to the entry, not just the slot, as the | |
1560 | slot can move in the call to cxx_eval_builtin_function_call. */ | |
1561 | *slot = entry = ggc_alloc<constexpr_call> (); | |
1562 | *entry = new_call; | |
1563 | } | |
2ba934c7 | 1564 | /* Calls that are in progress have their result set to NULL, |
c8f6aeb1 | 1565 | so that we can detect circular dependencies. */ |
1566 | else if (entry->result == NULL) | |
1567 | { | |
1568 | if (!ctx->quiet) | |
1569 | error ("call has circular dependency"); | |
1570 | *non_constant_p = true; | |
1571 | entry->result = result = error_mark_node; | |
1572 | } | |
1573 | else | |
1574 | result = entry->result; | |
09b42213 | 1575 | } |
1576 | ||
1577 | if (!depth_ok) | |
1578 | { | |
f83e6885 | 1579 | if (!ctx->quiet) |
09b42213 | 1580 | error ("constexpr evaluation depth exceeds maximum of %d (use " |
1581 | "-fconstexpr-depth= to increase the maximum)", | |
1582 | max_constexpr_depth); | |
1583 | *non_constant_p = true; | |
c8f6aeb1 | 1584 | result = error_mark_node; |
09b42213 | 1585 | } |
1586 | else | |
1587 | { | |
ab099088 | 1588 | if (result && result != error_mark_node) |
1589 | /* OK */; | |
1590 | else if (!DECL_SAVED_TREE (fun)) | |
1591 | { | |
1592 | /* When at_eof >= 2, cgraph has started throwing away | |
1593 | DECL_SAVED_TREE, so fail quietly. FIXME we get here because of | |
1594 | late code generation for VEC_INIT_EXPR, which needs to be | |
1595 | completely reconsidered. */ | |
1596 | gcc_assert (at_eof >= 2 && ctx->quiet); | |
1597 | *non_constant_p = true; | |
1598 | } | |
1599 | else | |
cf72f34d | 1600 | { |
4f7ebe46 | 1601 | tree body, parms, res; |
88a59139 | 1602 | |
4f7ebe46 | 1603 | /* Reuse or create a new unshared copy of this function's body. */ |
a050099a | 1604 | tree copy = get_fundef_copy (fun); |
1605 | body = TREE_PURPOSE (copy); | |
1606 | parms = TREE_VALUE (copy); | |
1607 | res = TREE_TYPE (copy); | |
88a59139 | 1608 | |
1609 | /* Associate the bindings with the remapped parms. */ | |
1610 | tree bound = new_call.bindings; | |
1611 | tree remapped = parms; | |
1612 | while (bound) | |
9c96033c | 1613 | { |
88a59139 | 1614 | tree oparm = TREE_PURPOSE (bound); |
1615 | tree arg = TREE_VALUE (bound); | |
1616 | gcc_assert (DECL_NAME (remapped) == DECL_NAME (oparm)); | |
5898f0d7 | 1617 | /* Don't share a CONSTRUCTOR that might be changed. */ |
e283bb4f | 1618 | arg = unshare_constructor (arg); |
88a59139 | 1619 | ctx->values->put (remapped, arg); |
1620 | bound = TREE_CHAIN (bound); | |
1621 | remapped = DECL_CHAIN (remapped); | |
9c96033c | 1622 | } |
88a59139 | 1623 | /* Add the RESULT_DECL to the values map, too. */ |
1624 | tree slot = NULL_TREE; | |
1625 | if (DECL_BY_REFERENCE (res)) | |
9c96033c | 1626 | { |
88a59139 | 1627 | slot = AGGR_INIT_EXPR_SLOT (t); |
1628 | tree addr = build_address (slot); | |
1629 | addr = build_nop (TREE_TYPE (res), addr); | |
1630 | ctx->values->put (res, addr); | |
1631 | ctx->values->put (slot, NULL_TREE); | |
1632 | } | |
1633 | else | |
1634 | ctx->values->put (res, NULL_TREE); | |
9c96033c | 1635 | |
4f7ebe46 | 1636 | /* Track the callee's evaluated SAVE_EXPRs so that we can forget |
1637 | their values after the call. */ | |
1638 | constexpr_ctx ctx_with_save_exprs = *ctx; | |
1639 | hash_set<tree> save_exprs; | |
1640 | ctx_with_save_exprs.save_exprs = &save_exprs; | |
43b7271d | 1641 | ctx_with_save_exprs.call = &new_call; |
4f7ebe46 | 1642 | |
88a59139 | 1643 | tree jump_target = NULL_TREE; |
4f7ebe46 | 1644 | cxx_eval_constant_expression (&ctx_with_save_exprs, body, |
88a59139 | 1645 | lval, non_constant_p, overflow_p, |
1646 | &jump_target); | |
9c96033c | 1647 | |
88a59139 | 1648 | if (DECL_CONSTRUCTOR_P (fun)) |
1649 | /* This can be null for a subobject constructor call, in | |
1650 | which case what we care about is the initialization | |
1651 | side-effects rather than the value. We could get at the | |
1652 | value by evaluating *this, but we don't bother; there's | |
1653 | no need to put such a call in the hash table. */ | |
1654 | result = lval ? ctx->object : ctx->ctor; | |
1655 | else if (VOID_TYPE_P (TREE_TYPE (res))) | |
1656 | result = void_node; | |
1657 | else | |
1658 | { | |
1659 | result = *ctx->values->get (slot ? slot : res); | |
1660 | if (result == NULL_TREE && !*non_constant_p) | |
9c96033c | 1661 | { |
88a59139 | 1662 | if (!ctx->quiet) |
1663 | error ("constexpr call flows off the end " | |
1664 | "of the function"); | |
1665 | *non_constant_p = true; | |
9c96033c | 1666 | } |
9c96033c | 1667 | } |
88a59139 | 1668 | |
4f7ebe46 | 1669 | /* Forget the saved values of the callee's SAVE_EXPRs. */ |
1670 | for (hash_set<tree>::iterator iter = save_exprs.begin(); | |
1671 | iter != save_exprs.end(); ++iter) | |
1672 | ctx_with_save_exprs.values->remove (*iter); | |
1673 | ||
88a59139 | 1674 | /* Remove the parms/result from the values map. Is it worth |
1675 | bothering to do this when the map itself is only live for | |
1676 | one constexpr evaluation? If so, maybe also clear out | |
1677 | other vars from call, maybe in BIND_EXPR handling? */ | |
1678 | ctx->values->remove (res); | |
1679 | if (slot) | |
1680 | ctx->values->remove (slot); | |
1681 | for (tree parm = parms; parm; parm = TREE_CHAIN (parm)) | |
1682 | ctx->values->remove (parm); | |
4f7ebe46 | 1683 | |
1684 | /* Make the unshared function copy we used available for re-use. */ | |
1685 | save_fundef_copy (fun, copy); | |
cf72f34d | 1686 | } |
9c96033c | 1687 | |
09b42213 | 1688 | if (result == error_mark_node) |
1689 | *non_constant_p = true; | |
c3f376bf | 1690 | if (*non_constant_p || *overflow_p) |
c8f6aeb1 | 1691 | result = error_mark_node; |
88a59139 | 1692 | else if (!result) |
9c96033c | 1693 | result = void_node; |
c8f6aeb1 | 1694 | if (entry) |
1695 | entry->result = result; | |
09b42213 | 1696 | } |
1697 | ||
c6d97004 | 1698 | /* The result of a constexpr function must be completely initialized. */ |
1699 | if (TREE_CODE (result) == CONSTRUCTOR) | |
1700 | CONSTRUCTOR_NO_IMPLICIT_ZERO (result) = false; | |
1701 | ||
09b42213 | 1702 | pop_cx_call_context (); |
e283bb4f | 1703 | return unshare_constructor (result); |
09b42213 | 1704 | } |
1705 | ||
1706 | /* FIXME speed this up, it's taking 16% of compile time on sieve testcase. */ | |
1707 | ||
1708 | bool | |
1709 | reduced_constant_expression_p (tree t) | |
1710 | { | |
1711 | switch (TREE_CODE (t)) | |
1712 | { | |
1713 | case PTRMEM_CST: | |
1714 | /* Even if we can't lower this yet, it's constant. */ | |
1715 | return true; | |
1716 | ||
1717 | case CONSTRUCTOR: | |
1718 | /* And we need to handle PTRMEM_CST wrapped in a CONSTRUCTOR. */ | |
1719 | tree elt; unsigned HOST_WIDE_INT idx; | |
1720 | FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (t), idx, elt) | |
ce4ffd9e | 1721 | { |
1722 | if (!elt) | |
1723 | /* We're in the middle of initializing this element. */ | |
1724 | return false; | |
1725 | if (!reduced_constant_expression_p (elt)) | |
1726 | return false; | |
1727 | } | |
09b42213 | 1728 | return true; |
1729 | ||
1730 | default: | |
1731 | /* FIXME are we calling this too much? */ | |
1732 | return initializer_constant_valid_p (t, TREE_TYPE (t)) != NULL_TREE; | |
1733 | } | |
1734 | } | |
1735 | ||
1736 | /* Some expressions may have constant operands but are not constant | |
1737 | themselves, such as 1/0. Call this function (or rather, the macro | |
1738 | following it) to check for that condition. | |
1739 | ||
1740 | We only call this in places that require an arithmetic constant, not in | |
1741 | places where we might have a non-constant expression that can be a | |
1742 | component of a constant expression, such as the address of a constexpr | |
1743 | variable that might be dereferenced later. */ | |
1744 | ||
1745 | static bool | |
1746 | verify_constant (tree t, bool allow_non_constant, bool *non_constant_p, | |
1747 | bool *overflow_p) | |
1748 | { | |
1749 | if (!*non_constant_p && !reduced_constant_expression_p (t)) | |
1750 | { | |
1751 | if (!allow_non_constant) | |
1752 | error ("%q+E is not a constant expression", t); | |
1753 | *non_constant_p = true; | |
1754 | } | |
1755 | if (TREE_OVERFLOW_P (t)) | |
1756 | { | |
1757 | if (!allow_non_constant) | |
1758 | { | |
1759 | permerror (input_location, "overflow in constant expression"); | |
1760 | /* If we're being permissive (and are in an enforcing | |
1761 | context), ignore the overflow. */ | |
1762 | if (flag_permissive) | |
1763 | return *non_constant_p; | |
1764 | } | |
1765 | *overflow_p = true; | |
1766 | } | |
1767 | return *non_constant_p; | |
1768 | } | |
1769 | ||
2b035ffe | 1770 | /* Check whether the shift operation with code CODE and type TYPE on LHS |
1771 | and RHS is undefined. If it is, give an error with an explanation, | |
1772 | and return true; return false otherwise. */ | |
1773 | ||
1774 | static bool | |
1775 | cxx_eval_check_shift_p (location_t loc, const constexpr_ctx *ctx, | |
1776 | enum tree_code code, tree type, tree lhs, tree rhs) | |
1777 | { | |
1778 | if ((code != LSHIFT_EXPR && code != RSHIFT_EXPR) | |
1779 | || TREE_CODE (lhs) != INTEGER_CST | |
1780 | || TREE_CODE (rhs) != INTEGER_CST) | |
1781 | return false; | |
1782 | ||
1783 | tree lhstype = TREE_TYPE (lhs); | |
1784 | unsigned HOST_WIDE_INT uprec = TYPE_PRECISION (TREE_TYPE (lhs)); | |
1785 | ||
1786 | /* [expr.shift] The behavior is undefined if the right operand | |
1787 | is negative, or greater than or equal to the length in bits | |
1788 | of the promoted left operand. */ | |
1789 | if (tree_int_cst_sgn (rhs) == -1) | |
1790 | { | |
1791 | if (!ctx->quiet) | |
91d87e22 | 1792 | permerror (loc, "right operand of shift expression %q+E is negative", |
1793 | build2_loc (loc, code, type, lhs, rhs)); | |
1794 | return (!flag_permissive || ctx->quiet); | |
2b035ffe | 1795 | } |
1796 | if (compare_tree_int (rhs, uprec) >= 0) | |
1797 | { | |
1798 | if (!ctx->quiet) | |
91d87e22 | 1799 | permerror (loc, "right operand of shift expression %q+E is >= than " |
1800 | "the precision of the left operand", | |
1801 | build2_loc (loc, code, type, lhs, rhs)); | |
1802 | return (!flag_permissive || ctx->quiet); | |
2b035ffe | 1803 | } |
1804 | ||
1805 | /* The value of E1 << E2 is E1 left-shifted E2 bit positions; [...] | |
1806 | if E1 has a signed type and non-negative value, and E1x2^E2 is | |
1807 | representable in the corresponding unsigned type of the result type, | |
1808 | then that value, converted to the result type, is the resulting value; | |
1809 | otherwise, the behavior is undefined. */ | |
1810 | if (code == LSHIFT_EXPR && !TYPE_UNSIGNED (lhstype) | |
1811 | && (cxx_dialect >= cxx11)) | |
1812 | { | |
1813 | if (tree_int_cst_sgn (lhs) == -1) | |
1814 | { | |
1815 | if (!ctx->quiet) | |
91d87e22 | 1816 | permerror (loc, |
1817 | "left operand of shift expression %q+E is negative", | |
1818 | build2_loc (loc, code, type, lhs, rhs)); | |
1819 | return (!flag_permissive || ctx->quiet); | |
2b035ffe | 1820 | } |
1821 | /* For signed x << y the following: | |
1822 | (unsigned) x >> ((prec (lhs) - 1) - y) | |
1823 | if > 1, is undefined. The right-hand side of this formula | |
1824 | is the highest bit of the LHS that can be set (starting from 0), | |
1825 | so that the shift doesn't overflow. We then right-shift the LHS | |
1826 | to see whether any other bit is set making the original shift | |
1827 | undefined -- the result is not representable in the corresponding | |
1828 | unsigned type. */ | |
1829 | tree t = build_int_cst (unsigned_type_node, uprec - 1); | |
1830 | t = fold_build2 (MINUS_EXPR, unsigned_type_node, t, rhs); | |
1831 | tree ulhs = fold_convert (unsigned_type_for (lhstype), lhs); | |
1832 | t = fold_build2 (RSHIFT_EXPR, TREE_TYPE (ulhs), ulhs, t); | |
1833 | if (tree_int_cst_lt (integer_one_node, t)) | |
1834 | { | |
1835 | if (!ctx->quiet) | |
91d87e22 | 1836 | permerror (loc, "shift expression %q+E overflows", |
1837 | build2_loc (loc, code, type, lhs, rhs)); | |
1838 | return (!flag_permissive || ctx->quiet); | |
2b035ffe | 1839 | } |
1840 | } | |
1841 | return false; | |
1842 | } | |
1843 | ||
09b42213 | 1844 | /* Subroutine of cxx_eval_constant_expression. |
1845 | Attempt to reduce the unary expression tree T to a compile time value. | |
1846 | If successful, return the value. Otherwise issue a diagnostic | |
1847 | and return error_mark_node. */ | |
1848 | ||
1849 | static tree | |
cf72f34d | 1850 | cxx_eval_unary_expression (const constexpr_ctx *ctx, tree t, |
c8f6aeb1 | 1851 | bool /*lval*/, |
09b42213 | 1852 | bool *non_constant_p, bool *overflow_p) |
1853 | { | |
1854 | tree r; | |
1855 | tree orig_arg = TREE_OPERAND (t, 0); | |
c8f6aeb1 | 1856 | tree arg = cxx_eval_constant_expression (ctx, orig_arg, /*lval*/false, |
1857 | non_constant_p, overflow_p); | |
09b42213 | 1858 | VERIFY_CONSTANT (arg); |
93add516 | 1859 | location_t loc = EXPR_LOCATION (t); |
1860 | enum tree_code code = TREE_CODE (t); | |
1861 | tree type = TREE_TYPE (t); | |
1862 | r = fold_unary_loc (loc, code, type, arg); | |
1863 | if (r == NULL_TREE) | |
1864 | { | |
1865 | if (arg == orig_arg) | |
1866 | r = t; | |
1867 | else | |
1868 | r = build1_loc (loc, code, type, arg); | |
1869 | } | |
09b42213 | 1870 | VERIFY_CONSTANT (r); |
1871 | return r; | |
1872 | } | |
1873 | ||
46fad8d5 | 1874 | /* Helper function for cxx_eval_binary_expression. Try to optimize |
1875 | original POINTER_PLUS_EXPR T, LHS p+ RHS, return NULL_TREE if the | |
1876 | generic folding should be used. */ | |
1877 | ||
1878 | static tree | |
1879 | cxx_fold_pointer_plus_expression (const constexpr_ctx *ctx, tree t, | |
1880 | tree lhs, tree rhs, bool *non_constant_p, | |
1881 | bool *overflow_p) | |
1882 | { | |
1883 | STRIP_NOPS (lhs); | |
1884 | if (TREE_CODE (lhs) != ADDR_EXPR) | |
1885 | return NULL_TREE; | |
1886 | ||
1887 | lhs = TREE_OPERAND (lhs, 0); | |
1888 | ||
1889 | /* &A[i] p+ j => &A[i + j] */ | |
1890 | if (TREE_CODE (lhs) == ARRAY_REF | |
1891 | && TREE_CODE (TREE_OPERAND (lhs, 1)) == INTEGER_CST | |
1892 | && TREE_CODE (rhs) == INTEGER_CST | |
1893 | && TYPE_SIZE_UNIT (TREE_TYPE (lhs)) | |
1894 | && TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (lhs))) == INTEGER_CST) | |
1895 | { | |
1896 | tree orig_type = TREE_TYPE (t); | |
1897 | location_t loc = EXPR_LOCATION (t); | |
1898 | tree type = TREE_TYPE (lhs); | |
1899 | ||
1900 | t = fold_convert_loc (loc, ssizetype, TREE_OPERAND (lhs, 1)); | |
1901 | tree nelts = array_type_nelts_top (TREE_TYPE (TREE_OPERAND (lhs, 0))); | |
1902 | nelts = cxx_eval_constant_expression (ctx, nelts, false, non_constant_p, | |
1903 | overflow_p); | |
1904 | if (*non_constant_p) | |
1905 | return NULL_TREE; | |
1906 | /* Don't fold an out-of-bound access. */ | |
1907 | if (!tree_int_cst_le (t, nelts)) | |
1908 | return NULL_TREE; | |
1909 | rhs = cp_fold_convert (ssizetype, rhs); | |
1910 | /* Don't fold if rhs can't be divided exactly by TYPE_SIZE_UNIT. | |
1911 | constexpr int A[1]; ... (char *)&A[0] + 1 */ | |
1912 | if (!integer_zerop (fold_build2_loc (loc, TRUNC_MOD_EXPR, sizetype, | |
1913 | rhs, TYPE_SIZE_UNIT (type)))) | |
1914 | return NULL_TREE; | |
1915 | /* Make sure to treat the second operand of POINTER_PLUS_EXPR | |
1916 | as signed. */ | |
1917 | rhs = fold_build2_loc (loc, EXACT_DIV_EXPR, ssizetype, rhs, | |
1918 | TYPE_SIZE_UNIT (type)); | |
1919 | t = size_binop_loc (loc, PLUS_EXPR, rhs, t); | |
1920 | t = build4_loc (loc, ARRAY_REF, type, TREE_OPERAND (lhs, 0), | |
1921 | t, NULL_TREE, NULL_TREE); | |
1922 | t = cp_build_addr_expr (t, tf_warning_or_error); | |
1923 | t = cp_fold_convert (orig_type, t); | |
1924 | return cxx_eval_constant_expression (ctx, t, /*lval*/false, | |
1925 | non_constant_p, overflow_p); | |
1926 | } | |
1927 | ||
1928 | return NULL_TREE; | |
1929 | } | |
1930 | ||
09b42213 | 1931 | /* Subroutine of cxx_eval_constant_expression. |
1932 | Like cxx_eval_unary_expression, except for binary expressions. */ | |
1933 | ||
1934 | static tree | |
cf72f34d | 1935 | cxx_eval_binary_expression (const constexpr_ctx *ctx, tree t, |
c8f6aeb1 | 1936 | bool /*lval*/, |
09b42213 | 1937 | bool *non_constant_p, bool *overflow_p) |
1938 | { | |
f7ef5392 | 1939 | tree r = NULL_TREE; |
09b42213 | 1940 | tree orig_lhs = TREE_OPERAND (t, 0); |
1941 | tree orig_rhs = TREE_OPERAND (t, 1); | |
1942 | tree lhs, rhs; | |
c8f6aeb1 | 1943 | lhs = cxx_eval_constant_expression (ctx, orig_lhs, /*lval*/false, |
b2a43197 | 1944 | non_constant_p, overflow_p); |
6d6737d9 | 1945 | /* Don't VERIFY_CONSTANT here, it's unnecessary and will break pointer |
1946 | subtraction. */ | |
1947 | if (*non_constant_p) | |
1948 | return t; | |
c8f6aeb1 | 1949 | rhs = cxx_eval_constant_expression (ctx, orig_rhs, /*lval*/false, |
b2a43197 | 1950 | non_constant_p, overflow_p); |
6d6737d9 | 1951 | if (*non_constant_p) |
1952 | return t; | |
93add516 | 1953 | |
1954 | location_t loc = EXPR_LOCATION (t); | |
1955 | enum tree_code code = TREE_CODE (t); | |
1956 | tree type = TREE_TYPE (t); | |
f7ef5392 | 1957 | |
1958 | if (code == EQ_EXPR || code == NE_EXPR) | |
1959 | { | |
1960 | bool is_code_eq = (code == EQ_EXPR); | |
1961 | ||
1962 | if (TREE_CODE (lhs) == PTRMEM_CST | |
1963 | && TREE_CODE (rhs) == PTRMEM_CST) | |
1964 | r = constant_boolean_node (cp_tree_equal (lhs, rhs) == is_code_eq, | |
1965 | type); | |
1966 | else if ((TREE_CODE (lhs) == PTRMEM_CST | |
1967 | || TREE_CODE (rhs) == PTRMEM_CST) | |
1968 | && (null_member_pointer_value_p (lhs) | |
1969 | || null_member_pointer_value_p (rhs))) | |
1970 | r = constant_boolean_node (!is_code_eq, type); | |
f31f4e9c | 1971 | else if (TREE_CODE (lhs) == PTRMEM_CST) |
1972 | lhs = cplus_expand_constant (lhs); | |
1973 | else if (TREE_CODE (rhs) == PTRMEM_CST) | |
1974 | rhs = cplus_expand_constant (rhs); | |
f7ef5392 | 1975 | } |
cb768824 | 1976 | if (code == POINTER_PLUS_EXPR && !*non_constant_p |
1977 | && integer_zerop (lhs) && !integer_zerop (rhs)) | |
1978 | { | |
1979 | if (!ctx->quiet) | |
1980 | error ("arithmetic involving a null pointer in %qE", lhs); | |
1981 | return t; | |
1982 | } | |
46fad8d5 | 1983 | else if (code == POINTER_PLUS_EXPR) |
1984 | r = cxx_fold_pointer_plus_expression (ctx, t, lhs, rhs, non_constant_p, | |
1985 | overflow_p); | |
f7ef5392 | 1986 | |
1987 | if (r == NULL_TREE) | |
1988 | r = fold_binary_loc (loc, code, type, lhs, rhs); | |
1989 | ||
93add516 | 1990 | if (r == NULL_TREE) |
1991 | { | |
1992 | if (lhs == orig_lhs && rhs == orig_rhs) | |
1993 | r = t; | |
1994 | else | |
1995 | r = build2_loc (loc, code, type, lhs, rhs); | |
1996 | } | |
2b035ffe | 1997 | else if (cxx_eval_check_shift_p (loc, ctx, code, type, lhs, rhs)) |
1998 | *non_constant_p = true; | |
6d6737d9 | 1999 | /* Don't VERIFY_CONSTANT if this might be dealing with a pointer to |
2000 | a local array in a constexpr function. */ | |
2001 | bool ptr = POINTER_TYPE_P (TREE_TYPE (lhs)); | |
35f2c28f | 2002 | if (!ptr) |
aae7465c | 2003 | VERIFY_CONSTANT (r); |
09b42213 | 2004 | return r; |
2005 | } | |
2006 | ||
2007 | /* Subroutine of cxx_eval_constant_expression. | |
2008 | Attempt to evaluate condition expressions. Dead branches are not | |
2009 | looked into. */ | |
2010 | ||
2011 | static tree | |
cf72f34d | 2012 | cxx_eval_conditional_expression (const constexpr_ctx *ctx, tree t, |
1227ba74 | 2013 | bool lval, |
00f21715 | 2014 | bool *non_constant_p, bool *overflow_p, |
2015 | tree *jump_target) | |
09b42213 | 2016 | { |
cf72f34d | 2017 | tree val = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), |
c8f6aeb1 | 2018 | /*lval*/false, |
b2a43197 | 2019 | non_constant_p, overflow_p); |
09b42213 | 2020 | VERIFY_CONSTANT (val); |
2021 | /* Don't VERIFY_CONSTANT the other operands. */ | |
2022 | if (integer_zerop (val)) | |
cf72f34d | 2023 | return cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 2), |
1227ba74 | 2024 | lval, |
00f21715 | 2025 | non_constant_p, overflow_p, |
2026 | jump_target); | |
cf72f34d | 2027 | return cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), |
1227ba74 | 2028 | lval, |
00f21715 | 2029 | non_constant_p, overflow_p, |
2030 | jump_target); | |
09b42213 | 2031 | } |
2032 | ||
7963b19d | 2033 | /* Returns less than, equal to, or greater than zero if KEY is found to be |
2034 | less than, to match, or to be greater than the constructor_elt's INDEX. */ | |
2035 | ||
2036 | static int | |
2037 | array_index_cmp (tree key, tree index) | |
2038 | { | |
2039 | gcc_assert (TREE_CODE (key) == INTEGER_CST); | |
2040 | ||
2041 | switch (TREE_CODE (index)) | |
2042 | { | |
2043 | case INTEGER_CST: | |
2044 | return tree_int_cst_compare (key, index); | |
2045 | case RANGE_EXPR: | |
2046 | { | |
2047 | tree lo = TREE_OPERAND (index, 0); | |
2048 | tree hi = TREE_OPERAND (index, 1); | |
2049 | if (tree_int_cst_lt (key, lo)) | |
2050 | return -1; | |
2051 | else if (tree_int_cst_lt (hi, key)) | |
2052 | return 1; | |
2053 | else | |
2054 | return 0; | |
2055 | } | |
2056 | default: | |
2057 | gcc_unreachable (); | |
2058 | } | |
2059 | } | |
2060 | ||
2061 | /* Returns the index of the constructor_elt of ARY which matches DINDEX, or -1 | |
2062 | if none. If INSERT is true, insert a matching element rather than fail. */ | |
2063 | ||
2064 | static HOST_WIDE_INT | |
2065 | find_array_ctor_elt (tree ary, tree dindex, bool insert = false) | |
2066 | { | |
2067 | if (tree_int_cst_sgn (dindex) < 0) | |
2068 | return -1; | |
2069 | ||
2070 | unsigned HOST_WIDE_INT i = tree_to_uhwi (dindex); | |
2071 | vec<constructor_elt, va_gc> *elts = CONSTRUCTOR_ELTS (ary); | |
2072 | unsigned HOST_WIDE_INT len = vec_safe_length (elts); | |
2073 | ||
2074 | unsigned HOST_WIDE_INT end = len; | |
2075 | unsigned HOST_WIDE_INT begin = 0; | |
2076 | ||
2077 | /* If the last element of the CONSTRUCTOR has its own index, we can assume | |
2078 | that the same is true of the other elements and index directly. */ | |
2079 | if (end > 0) | |
2080 | { | |
2081 | tree cindex = (*elts)[end-1].index; | |
2082 | if (TREE_CODE (cindex) == INTEGER_CST | |
2083 | && compare_tree_int (cindex, end-1) == 0) | |
2084 | { | |
2085 | if (i < end) | |
2086 | return i; | |
2087 | else | |
2088 | begin = end; | |
2089 | } | |
2090 | } | |
2091 | ||
2092 | /* Otherwise, find a matching index by means of a binary search. */ | |
2093 | while (begin != end) | |
2094 | { | |
2095 | unsigned HOST_WIDE_INT middle = (begin + end) / 2; | |
f0b916c7 | 2096 | constructor_elt &elt = (*elts)[middle]; |
2097 | tree idx = elt.index; | |
7963b19d | 2098 | |
f0b916c7 | 2099 | int cmp = array_index_cmp (dindex, idx); |
7963b19d | 2100 | if (cmp < 0) |
2101 | end = middle; | |
2102 | else if (cmp > 0) | |
2103 | begin = middle + 1; | |
2104 | else | |
f0b916c7 | 2105 | { |
2106 | if (insert && TREE_CODE (idx) == RANGE_EXPR) | |
2107 | { | |
2108 | /* We need to split the range. */ | |
2109 | constructor_elt e; | |
2110 | tree lo = TREE_OPERAND (idx, 0); | |
2111 | tree hi = TREE_OPERAND (idx, 1); | |
2112 | if (tree_int_cst_lt (lo, dindex)) | |
2113 | { | |
2114 | /* There are still some lower elts; shorten the range. */ | |
2115 | tree new_hi = int_const_binop (MINUS_EXPR, dindex, | |
2116 | size_one_node); | |
2117 | if (tree_int_cst_equal (lo, new_hi)) | |
2118 | /* Only one element left, no longer a range. */ | |
2119 | elt.index = lo; | |
2120 | else | |
2121 | TREE_OPERAND (idx, 1) = new_hi; | |
2122 | /* Append the element we want to insert. */ | |
2123 | ++middle; | |
2124 | e.index = dindex; | |
e283bb4f | 2125 | e.value = unshare_constructor (elt.value); |
f0b916c7 | 2126 | vec_safe_insert (CONSTRUCTOR_ELTS (ary), middle, e); |
2127 | } | |
2128 | else | |
2129 | /* No lower elts, the range elt is now ours. */ | |
2130 | elt.index = dindex; | |
2131 | ||
2132 | if (tree_int_cst_lt (dindex, hi)) | |
2133 | { | |
2134 | /* There are still some higher elts; append a range. */ | |
2135 | tree new_lo = int_const_binop (PLUS_EXPR, dindex, | |
2136 | size_one_node); | |
2137 | if (tree_int_cst_equal (new_lo, hi)) | |
2138 | e.index = hi; | |
2139 | else | |
2140 | e.index = build2 (RANGE_EXPR, sizetype, new_lo, hi); | |
e283bb4f | 2141 | e.value = unshare_constructor (elt.value); |
f0b916c7 | 2142 | vec_safe_insert (CONSTRUCTOR_ELTS (ary), middle+1, e); |
2143 | } | |
2144 | } | |
2145 | return middle; | |
2146 | } | |
7963b19d | 2147 | } |
2148 | ||
2149 | if (insert) | |
2150 | { | |
2151 | constructor_elt e = { dindex, NULL_TREE }; | |
2152 | vec_safe_insert (CONSTRUCTOR_ELTS (ary), end, e); | |
2153 | return end; | |
2154 | } | |
2155 | ||
2156 | return -1; | |
2157 | } | |
2158 | ||
40df9099 | 2159 | /* Under the control of CTX, issue a detailed diagnostic for |
2160 | an out-of-bounds subscript INDEX into the expression ARRAY. */ | |
2161 | ||
2162 | static void | |
2163 | diag_array_subscript (const constexpr_ctx *ctx, tree array, tree index) | |
2164 | { | |
2165 | if (!ctx->quiet) | |
2166 | { | |
2167 | tree arraytype = TREE_TYPE (array); | |
2168 | ||
2169 | /* Convert the unsigned array subscript to a signed integer to avoid | |
2170 | printing huge numbers for small negative values. */ | |
2171 | tree sidx = fold_convert (ssizetype, index); | |
2172 | if (DECL_P (array)) | |
2173 | { | |
2174 | error ("array subscript value %qE is outside the bounds " | |
2175 | "of array %qD of type %qT", sidx, array, arraytype); | |
2176 | inform (DECL_SOURCE_LOCATION (array), "declared here"); | |
2177 | } | |
2178 | else | |
2179 | error ("array subscript value %qE is outside the bounds " | |
2180 | "of array type %qT", sidx, arraytype); | |
2181 | } | |
2182 | } | |
7963b19d | 2183 | |
92fe8840 | 2184 | /* Extract element INDEX consisting of CHARS_PER_ELT chars from |
2185 | STRING_CST STRING. */ | |
2186 | ||
2187 | static tree | |
2188 | extract_string_elt (tree string, unsigned chars_per_elt, unsigned index) | |
2189 | { | |
2190 | tree type = cv_unqualified (TREE_TYPE (TREE_TYPE (string))); | |
2191 | tree r; | |
2192 | ||
2193 | if (chars_per_elt == 1) | |
2194 | r = build_int_cst (type, TREE_STRING_POINTER (string)[index]); | |
2195 | else | |
2196 | { | |
2197 | const unsigned char *ptr | |
2198 | = ((const unsigned char *)TREE_STRING_POINTER (string) | |
2199 | + index * chars_per_elt); | |
2200 | r = native_interpret_expr (type, ptr, chars_per_elt); | |
2201 | } | |
2202 | return r; | |
2203 | } | |
2204 | ||
09b42213 | 2205 | /* Subroutine of cxx_eval_constant_expression. |
2206 | Attempt to reduce a reference to an array slot. */ | |
2207 | ||
2208 | static tree | |
cf72f34d | 2209 | cxx_eval_array_reference (const constexpr_ctx *ctx, tree t, |
1227ba74 | 2210 | bool lval, |
09b42213 | 2211 | bool *non_constant_p, bool *overflow_p) |
2212 | { | |
2213 | tree oldary = TREE_OPERAND (t, 0); | |
cf72f34d | 2214 | tree ary = cxx_eval_constant_expression (ctx, oldary, |
1227ba74 | 2215 | lval, |
b2a43197 | 2216 | non_constant_p, overflow_p); |
09b42213 | 2217 | tree index, oldidx; |
cf3cefc9 | 2218 | HOST_WIDE_INT i = 0; |
2219 | tree elem_type = NULL_TREE; | |
2220 | unsigned len = 0, elem_nchars = 1; | |
09b42213 | 2221 | if (*non_constant_p) |
2222 | return t; | |
2223 | oldidx = TREE_OPERAND (t, 1); | |
cf72f34d | 2224 | index = cxx_eval_constant_expression (ctx, oldidx, |
f83e6885 | 2225 | false, |
b2a43197 | 2226 | non_constant_p, overflow_p); |
09b42213 | 2227 | VERIFY_CONSTANT (index); |
cf3cefc9 | 2228 | if (!lval) |
09b42213 | 2229 | { |
cf3cefc9 | 2230 | elem_type = TREE_TYPE (TREE_TYPE (ary)); |
2231 | if (TREE_CODE (ary) == VIEW_CONVERT_EXPR | |
2232 | && VECTOR_TYPE_P (TREE_TYPE (TREE_OPERAND (ary, 0))) | |
2233 | && TREE_TYPE (t) == TREE_TYPE (TREE_TYPE (TREE_OPERAND (ary, 0)))) | |
2234 | ary = TREE_OPERAND (ary, 0); | |
2235 | if (TREE_CODE (ary) == CONSTRUCTOR) | |
2236 | len = CONSTRUCTOR_NELTS (ary); | |
2237 | else if (TREE_CODE (ary) == STRING_CST) | |
2238 | { | |
2239 | elem_nchars = (TYPE_PRECISION (elem_type) | |
2240 | / TYPE_PRECISION (char_type_node)); | |
2241 | len = (unsigned) TREE_STRING_LENGTH (ary) / elem_nchars; | |
2242 | } | |
2243 | else if (TREE_CODE (ary) == VECTOR_CST) | |
2244 | len = VECTOR_CST_NELTS (ary); | |
2245 | else | |
2246 | { | |
2247 | /* We can't do anything with other tree codes, so use | |
2248 | VERIFY_CONSTANT to complain and fail. */ | |
2249 | VERIFY_CONSTANT (ary); | |
2250 | gcc_unreachable (); | |
2251 | } | |
aed8dc7f | 2252 | |
cf3cefc9 | 2253 | if (!tree_fits_shwi_p (index) |
2254 | || (i = tree_to_shwi (index)) < 0) | |
2255 | { | |
2256 | diag_array_subscript (ctx, ary, index); | |
2257 | *non_constant_p = true; | |
2258 | return t; | |
2259 | } | |
7963b19d | 2260 | } |
2261 | ||
7345b977 | 2262 | tree nelts; |
2263 | if (TREE_CODE (TREE_TYPE (ary)) == ARRAY_TYPE) | |
2264 | nelts = array_type_nelts_top (TREE_TYPE (ary)); | |
2265 | else if (VECTOR_TYPE_P (TREE_TYPE (ary))) | |
2266 | nelts = size_int (TYPE_VECTOR_SUBPARTS (TREE_TYPE (ary))); | |
2267 | else | |
2268 | gcc_unreachable (); | |
2269 | ||
ce6a6978 | 2270 | /* For VLAs, the number of elements won't be an integer constant. */ |
2271 | nelts = cxx_eval_constant_expression (ctx, nelts, false, non_constant_p, | |
2272 | overflow_p); | |
2273 | VERIFY_CONSTANT (nelts); | |
0acc6340 | 2274 | if ((lval |
2275 | ? !tree_int_cst_le (index, nelts) | |
2276 | : !tree_int_cst_lt (index, nelts)) | |
2277 | || tree_int_cst_sgn (index) < 0) | |
ce6a6978 | 2278 | { |
40df9099 | 2279 | diag_array_subscript (ctx, ary, index); |
ce6a6978 | 2280 | *non_constant_p = true; |
2281 | return t; | |
2282 | } | |
2283 | ||
cf3cefc9 | 2284 | if (lval && ary == oldary && index == oldidx) |
2285 | return t; | |
2286 | else if (lval) | |
2287 | return build4 (ARRAY_REF, TREE_TYPE (t), ary, index, NULL, NULL); | |
2288 | ||
7963b19d | 2289 | bool found; |
2290 | if (TREE_CODE (ary) == CONSTRUCTOR) | |
2291 | { | |
2292 | HOST_WIDE_INT ix = find_array_ctor_elt (ary, index); | |
2293 | found = (ix >= 0); | |
2294 | if (found) | |
2295 | i = ix; | |
aed8dc7f | 2296 | } |
7963b19d | 2297 | else |
2298 | found = (i < len); | |
aed8dc7f | 2299 | |
14869f28 | 2300 | if (found) |
2301 | { | |
2302 | tree r; | |
2303 | if (TREE_CODE (ary) == CONSTRUCTOR) | |
2304 | r = (*CONSTRUCTOR_ELTS (ary))[i].value; | |
2305 | else if (TREE_CODE (ary) == VECTOR_CST) | |
2306 | r = VECTOR_CST_ELT (ary, i); | |
14869f28 | 2307 | else |
92fe8840 | 2308 | r = extract_string_elt (ary, elem_nchars, i); |
2309 | ||
14869f28 | 2310 | if (r) |
2311 | /* Don't VERIFY_CONSTANT here. */ | |
2312 | return r; | |
09b42213 | 2313 | |
14869f28 | 2314 | /* Otherwise the element doesn't have a value yet. */ |
09b42213 | 2315 | } |
aed8dc7f | 2316 | |
14869f28 | 2317 | /* Not found. */ |
2318 | ||
2319 | if (TREE_CODE (ary) == CONSTRUCTOR | |
2320 | && CONSTRUCTOR_NO_IMPLICIT_ZERO (ary)) | |
09b42213 | 2321 | { |
14869f28 | 2322 | /* 'ary' is part of the aggregate initializer we're currently |
2323 | building; if there's no initializer for this element yet, | |
2324 | that's an error. */ | |
2325 | if (!ctx->quiet) | |
2326 | error ("accessing uninitialized array element"); | |
2327 | *non_constant_p = true; | |
2328 | return t; | |
09b42213 | 2329 | } |
14869f28 | 2330 | |
2331 | /* If it's within the array bounds but doesn't have an explicit | |
2332 | initializer, it's value-initialized. */ | |
2333 | tree val = build_value_init (elem_type, tf_warning_or_error); | |
2334 | return cxx_eval_constant_expression (ctx, val, lval, non_constant_p, | |
2335 | overflow_p); | |
09b42213 | 2336 | } |
2337 | ||
2338 | /* Subroutine of cxx_eval_constant_expression. | |
2339 | Attempt to reduce a field access of a value of class type. */ | |
2340 | ||
2341 | static tree | |
cf72f34d | 2342 | cxx_eval_component_reference (const constexpr_ctx *ctx, tree t, |
1227ba74 | 2343 | bool lval, |
09b42213 | 2344 | bool *non_constant_p, bool *overflow_p) |
2345 | { | |
2346 | unsigned HOST_WIDE_INT i; | |
2347 | tree field; | |
2348 | tree value; | |
2349 | tree part = TREE_OPERAND (t, 1); | |
2350 | tree orig_whole = TREE_OPERAND (t, 0); | |
cf72f34d | 2351 | tree whole = cxx_eval_constant_expression (ctx, orig_whole, |
1227ba74 | 2352 | lval, |
b2a43197 | 2353 | non_constant_p, overflow_p); |
cb768824 | 2354 | if (TREE_CODE (whole) == INDIRECT_REF |
2355 | && integer_zerop (TREE_OPERAND (whole, 0)) | |
2356 | && !ctx->quiet) | |
2357 | error ("dereferencing a null pointer in %qE", orig_whole); | |
2358 | ||
f16ed232 | 2359 | if (TREE_CODE (whole) == PTRMEM_CST) |
2360 | whole = cplus_expand_constant (whole); | |
09b42213 | 2361 | if (whole == orig_whole) |
2362 | return t; | |
1227ba74 | 2363 | if (lval) |
09b42213 | 2364 | return fold_build3 (COMPONENT_REF, TREE_TYPE (t), |
2365 | whole, part, NULL_TREE); | |
2366 | /* Don't VERIFY_CONSTANT here; we only want to check that we got a | |
2367 | CONSTRUCTOR. */ | |
2368 | if (!*non_constant_p && TREE_CODE (whole) != CONSTRUCTOR) | |
2369 | { | |
f83e6885 | 2370 | if (!ctx->quiet) |
09b42213 | 2371 | error ("%qE is not a constant expression", orig_whole); |
2372 | *non_constant_p = true; | |
2373 | } | |
2374 | if (DECL_MUTABLE_P (part)) | |
2375 | { | |
f83e6885 | 2376 | if (!ctx->quiet) |
09b42213 | 2377 | error ("mutable %qD is not usable in a constant expression", part); |
2378 | *non_constant_p = true; | |
2379 | } | |
2380 | if (*non_constant_p) | |
2381 | return t; | |
a4360e57 | 2382 | bool pmf = TYPE_PTRMEMFUNC_P (TREE_TYPE (whole)); |
09b42213 | 2383 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (whole), i, field, value) |
2384 | { | |
a4360e57 | 2385 | /* Use name match for PMF fields, as a variant will have a |
2386 | different FIELD_DECL with a different type. */ | |
2387 | if (pmf ? DECL_NAME (field) == DECL_NAME (part) | |
2388 | : field == part) | |
9c96033c | 2389 | { |
2390 | if (value) | |
2391 | return value; | |
2392 | else | |
2393 | /* We're in the middle of initializing it. */ | |
2394 | break; | |
2395 | } | |
09b42213 | 2396 | } |
2397 | if (TREE_CODE (TREE_TYPE (whole)) == UNION_TYPE | |
2398 | && CONSTRUCTOR_NELTS (whole) > 0) | |
2399 | { | |
2400 | /* DR 1188 says we don't have to deal with this. */ | |
f83e6885 | 2401 | if (!ctx->quiet) |
09b42213 | 2402 | error ("accessing %qD member instead of initialized %qD member in " |
2403 | "constant expression", part, CONSTRUCTOR_ELT (whole, 0)->index); | |
2404 | *non_constant_p = true; | |
2405 | return t; | |
2406 | } | |
2407 | ||
f894a056 | 2408 | /* We only create a CONSTRUCTOR for a subobject when we modify it, so empty |
2409 | classes never get represented; throw together a value now. */ | |
2410 | if (is_really_empty_class (TREE_TYPE (t))) | |
2411 | return build_constructor (TREE_TYPE (t), NULL); | |
2412 | ||
a4360e57 | 2413 | gcc_assert (DECL_CONTEXT (part) == TYPE_MAIN_VARIANT (TREE_TYPE (whole))); |
2414 | ||
f894a056 | 2415 | if (CONSTRUCTOR_NO_IMPLICIT_ZERO (whole)) |
cf72f34d | 2416 | { |
2417 | /* 'whole' is part of the aggregate initializer we're currently | |
2418 | building; if there's no initializer for this member yet, that's an | |
f894a056 | 2419 | error. */ |
f83e6885 | 2420 | if (!ctx->quiet) |
cf72f34d | 2421 | error ("accessing uninitialized member %qD", part); |
2422 | *non_constant_p = true; | |
2423 | return t; | |
2424 | } | |
2425 | ||
09b42213 | 2426 | /* If there's no explicit init for this field, it's value-initialized. */ |
2427 | value = build_value_init (TREE_TYPE (t), tf_warning_or_error); | |
cf72f34d | 2428 | return cxx_eval_constant_expression (ctx, value, |
1227ba74 | 2429 | lval, |
b2a43197 | 2430 | non_constant_p, overflow_p); |
09b42213 | 2431 | } |
2432 | ||
2433 | /* Subroutine of cxx_eval_constant_expression. | |
2434 | Attempt to reduce a field access of a value of class type that is | |
2435 | expressed as a BIT_FIELD_REF. */ | |
2436 | ||
2437 | static tree | |
cf72f34d | 2438 | cxx_eval_bit_field_ref (const constexpr_ctx *ctx, tree t, |
1227ba74 | 2439 | bool lval, |
09b42213 | 2440 | bool *non_constant_p, bool *overflow_p) |
2441 | { | |
2442 | tree orig_whole = TREE_OPERAND (t, 0); | |
2443 | tree retval, fldval, utype, mask; | |
2444 | bool fld_seen = false; | |
2445 | HOST_WIDE_INT istart, isize; | |
cf72f34d | 2446 | tree whole = cxx_eval_constant_expression (ctx, orig_whole, |
1227ba74 | 2447 | lval, |
b2a43197 | 2448 | non_constant_p, overflow_p); |
09b42213 | 2449 | tree start, field, value; |
2450 | unsigned HOST_WIDE_INT i; | |
2451 | ||
2452 | if (whole == orig_whole) | |
2453 | return t; | |
2454 | /* Don't VERIFY_CONSTANT here; we only want to check that we got a | |
2455 | CONSTRUCTOR. */ | |
2456 | if (!*non_constant_p | |
2457 | && TREE_CODE (whole) != VECTOR_CST | |
2458 | && TREE_CODE (whole) != CONSTRUCTOR) | |
2459 | { | |
f83e6885 | 2460 | if (!ctx->quiet) |
09b42213 | 2461 | error ("%qE is not a constant expression", orig_whole); |
2462 | *non_constant_p = true; | |
2463 | } | |
2464 | if (*non_constant_p) | |
2465 | return t; | |
2466 | ||
2467 | if (TREE_CODE (whole) == VECTOR_CST) | |
2468 | return fold_ternary (BIT_FIELD_REF, TREE_TYPE (t), whole, | |
2469 | TREE_OPERAND (t, 1), TREE_OPERAND (t, 2)); | |
2470 | ||
2471 | start = TREE_OPERAND (t, 2); | |
2472 | istart = tree_to_shwi (start); | |
2473 | isize = tree_to_shwi (TREE_OPERAND (t, 1)); | |
2474 | utype = TREE_TYPE (t); | |
2475 | if (!TYPE_UNSIGNED (utype)) | |
2476 | utype = build_nonstandard_integer_type (TYPE_PRECISION (utype), 1); | |
2477 | retval = build_int_cst (utype, 0); | |
2478 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (whole), i, field, value) | |
2479 | { | |
2480 | tree bitpos = bit_position (field); | |
2481 | if (bitpos == start && DECL_SIZE (field) == TREE_OPERAND (t, 1)) | |
2482 | return value; | |
2483 | if (TREE_CODE (TREE_TYPE (field)) == INTEGER_TYPE | |
2484 | && TREE_CODE (value) == INTEGER_CST | |
2485 | && tree_fits_shwi_p (bitpos) | |
2486 | && tree_fits_shwi_p (DECL_SIZE (field))) | |
2487 | { | |
2488 | HOST_WIDE_INT bit = tree_to_shwi (bitpos); | |
2489 | HOST_WIDE_INT sz = tree_to_shwi (DECL_SIZE (field)); | |
2490 | HOST_WIDE_INT shift; | |
2491 | if (bit >= istart && bit + sz <= istart + isize) | |
2492 | { | |
2493 | fldval = fold_convert (utype, value); | |
2494 | mask = build_int_cst_type (utype, -1); | |
2495 | mask = fold_build2 (LSHIFT_EXPR, utype, mask, | |
2496 | size_int (TYPE_PRECISION (utype) - sz)); | |
2497 | mask = fold_build2 (RSHIFT_EXPR, utype, mask, | |
2498 | size_int (TYPE_PRECISION (utype) - sz)); | |
2499 | fldval = fold_build2 (BIT_AND_EXPR, utype, fldval, mask); | |
2500 | shift = bit - istart; | |
2501 | if (BYTES_BIG_ENDIAN) | |
2502 | shift = TYPE_PRECISION (utype) - shift - sz; | |
2503 | fldval = fold_build2 (LSHIFT_EXPR, utype, fldval, | |
2504 | size_int (shift)); | |
2505 | retval = fold_build2 (BIT_IOR_EXPR, utype, retval, fldval); | |
2506 | fld_seen = true; | |
2507 | } | |
2508 | } | |
2509 | } | |
2510 | if (fld_seen) | |
2511 | return fold_convert (TREE_TYPE (t), retval); | |
2512 | gcc_unreachable (); | |
2513 | return error_mark_node; | |
2514 | } | |
2515 | ||
2516 | /* Subroutine of cxx_eval_constant_expression. | |
2517 | Evaluate a short-circuited logical expression T in the context | |
2518 | of a given constexpr CALL. BAILOUT_VALUE is the value for | |
2519 | early return. CONTINUE_VALUE is used here purely for | |
2520 | sanity check purposes. */ | |
2521 | ||
2522 | static tree | |
cf72f34d | 2523 | cxx_eval_logical_expression (const constexpr_ctx *ctx, tree t, |
09b42213 | 2524 | tree bailout_value, tree continue_value, |
1227ba74 | 2525 | bool lval, |
09b42213 | 2526 | bool *non_constant_p, bool *overflow_p) |
2527 | { | |
2528 | tree r; | |
cf72f34d | 2529 | tree lhs = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), |
1227ba74 | 2530 | lval, |
b2a43197 | 2531 | non_constant_p, overflow_p); |
09b42213 | 2532 | VERIFY_CONSTANT (lhs); |
2533 | if (tree_int_cst_equal (lhs, bailout_value)) | |
2534 | return lhs; | |
2535 | gcc_assert (tree_int_cst_equal (lhs, continue_value)); | |
cf72f34d | 2536 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), |
1227ba74 | 2537 | lval, non_constant_p, |
b2a43197 | 2538 | overflow_p); |
09b42213 | 2539 | VERIFY_CONSTANT (r); |
2540 | return r; | |
2541 | } | |
2542 | ||
2543 | /* REF is a COMPONENT_REF designating a particular field. V is a vector of | |
2544 | CONSTRUCTOR elements to initialize (part of) an object containing that | |
2545 | field. Return a pointer to the constructor_elt corresponding to the | |
2546 | initialization of the field. */ | |
2547 | ||
2548 | static constructor_elt * | |
2549 | base_field_constructor_elt (vec<constructor_elt, va_gc> *v, tree ref) | |
2550 | { | |
2551 | tree aggr = TREE_OPERAND (ref, 0); | |
2552 | tree field = TREE_OPERAND (ref, 1); | |
2553 | HOST_WIDE_INT i; | |
2554 | constructor_elt *ce; | |
2555 | ||
2556 | gcc_assert (TREE_CODE (ref) == COMPONENT_REF); | |
2557 | ||
2558 | if (TREE_CODE (aggr) == COMPONENT_REF) | |
2559 | { | |
2560 | constructor_elt *base_ce | |
2561 | = base_field_constructor_elt (v, aggr); | |
2562 | v = CONSTRUCTOR_ELTS (base_ce->value); | |
2563 | } | |
2564 | ||
2565 | for (i = 0; vec_safe_iterate (v, i, &ce); ++i) | |
2566 | if (ce->index == field) | |
2567 | return ce; | |
2568 | ||
2569 | gcc_unreachable (); | |
2570 | return NULL; | |
2571 | } | |
2572 | ||
cf72f34d | 2573 | /* Some of the expressions fed to the constexpr mechanism are calls to |
2574 | constructors, which have type void. In that case, return the type being | |
2575 | initialized by the constructor. */ | |
2576 | ||
2577 | static tree | |
2578 | initialized_type (tree t) | |
2579 | { | |
2580 | if (TYPE_P (t)) | |
2581 | return t; | |
2582 | tree type = cv_unqualified (TREE_TYPE (t)); | |
2583 | if (TREE_CODE (t) == CALL_EXPR || TREE_CODE (t) == AGGR_INIT_EXPR) | |
2584 | { | |
2585 | /* A constructor call has void type, so we need to look deeper. */ | |
2586 | tree fn = get_function_named_in_call (t); | |
2587 | if (fn && TREE_CODE (fn) == FUNCTION_DECL | |
2588 | && DECL_CXX_CONSTRUCTOR_P (fn)) | |
2589 | type = DECL_CONTEXT (fn); | |
2590 | } | |
2591 | return type; | |
2592 | } | |
2593 | ||
2594 | /* We're about to initialize element INDEX of an array or class from VALUE. | |
2595 | Set up NEW_CTX appropriately by adjusting .object to refer to the | |
2596 | subobject and creating a new CONSTRUCTOR if the element is itself | |
2597 | a class or array. */ | |
2598 | ||
2599 | static void | |
2600 | init_subob_ctx (const constexpr_ctx *ctx, constexpr_ctx &new_ctx, | |
2601 | tree index, tree &value) | |
2602 | { | |
2603 | new_ctx = *ctx; | |
2604 | ||
2605 | if (index && TREE_CODE (index) != INTEGER_CST | |
2606 | && TREE_CODE (index) != FIELD_DECL) | |
2607 | /* This won't have an element in the new CONSTRUCTOR. */ | |
2608 | return; | |
2609 | ||
2610 | tree type = initialized_type (value); | |
2611 | if (!AGGREGATE_TYPE_P (type) && !VECTOR_TYPE_P (type)) | |
2612 | /* A non-aggregate member doesn't get its own CONSTRUCTOR. */ | |
2613 | return; | |
2614 | ||
2615 | /* The sub-aggregate initializer might contain a placeholder; | |
2616 | update object to refer to the subobject and ctor to refer to | |
2617 | the (newly created) sub-initializer. */ | |
2618 | if (ctx->object) | |
2619 | new_ctx.object = build_ctor_subob_ref (index, type, ctx->object); | |
2620 | tree elt = build_constructor (type, NULL); | |
2621 | CONSTRUCTOR_NO_IMPLICIT_ZERO (elt) = true; | |
2622 | new_ctx.ctor = elt; | |
2623 | ||
2624 | if (TREE_CODE (value) == TARGET_EXPR) | |
2625 | /* Avoid creating another CONSTRUCTOR when we expand the TARGET_EXPR. */ | |
2626 | value = TARGET_EXPR_INITIAL (value); | |
2627 | } | |
2628 | ||
2629 | /* We're about to process an initializer for a class or array TYPE. Make | |
2630 | sure that CTX is set up appropriately. */ | |
2631 | ||
2632 | static void | |
2633 | verify_ctor_sanity (const constexpr_ctx *ctx, tree type) | |
2634 | { | |
2635 | /* We don't bother building a ctor for an empty base subobject. */ | |
2636 | if (is_empty_class (type)) | |
2637 | return; | |
2638 | ||
2639 | /* We're in the middle of an initializer that might involve placeholders; | |
2640 | our caller should have created a CONSTRUCTOR for us to put the | |
2641 | initializer into. We will either return that constructor or T. */ | |
2642 | gcc_assert (ctx->ctor); | |
2643 | gcc_assert (same_type_ignoring_top_level_qualifiers_p | |
2644 | (type, TREE_TYPE (ctx->ctor))); | |
bbf58224 | 2645 | /* We used to check that ctx->ctor was empty, but that isn't the case when |
2646 | the object is zero-initialized before calling the constructor. */ | |
cf72f34d | 2647 | if (ctx->object) |
d9751a3c | 2648 | { |
2649 | tree otype = TREE_TYPE (ctx->object); | |
2650 | gcc_assert (same_type_ignoring_top_level_qualifiers_p (type, otype) | |
2651 | /* Handle flexible array members. */ | |
2652 | || (TREE_CODE (otype) == ARRAY_TYPE | |
2653 | && TYPE_DOMAIN (otype) == NULL_TREE | |
2654 | && TREE_CODE (type) == ARRAY_TYPE | |
2655 | && (same_type_ignoring_top_level_qualifiers_p | |
2656 | (TREE_TYPE (type), TREE_TYPE (otype))))); | |
2657 | } | |
cf72f34d | 2658 | gcc_assert (!ctx->object || !DECL_P (ctx->object) |
2659 | || *(ctx->values->get (ctx->object)) == ctx->ctor); | |
2660 | } | |
2661 | ||
09b42213 | 2662 | /* Subroutine of cxx_eval_constant_expression. |
2663 | The expression tree T denotes a C-style array or a C-style | |
2664 | aggregate. Reduce it to a constant expression. */ | |
2665 | ||
2666 | static tree | |
cf72f34d | 2667 | cxx_eval_bare_aggregate (const constexpr_ctx *ctx, tree t, |
1227ba74 | 2668 | bool lval, |
09b42213 | 2669 | bool *non_constant_p, bool *overflow_p) |
2670 | { | |
2671 | vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (t); | |
09b42213 | 2672 | bool changed = false; |
2673 | gcc_assert (!BRACE_ENCLOSED_INITIALIZER_P (t)); | |
68464393 | 2674 | tree type = TREE_TYPE (t); |
cf72f34d | 2675 | |
68464393 | 2676 | constexpr_ctx new_ctx; |
d2dd85e3 | 2677 | if (TYPE_PTRMEMFUNC_P (type) || VECTOR_TYPE_P (type)) |
68464393 | 2678 | { |
d2dd85e3 | 2679 | /* We don't really need the ctx->ctor business for a PMF or |
2680 | vector, but it's simpler to use the same code. */ | |
68464393 | 2681 | new_ctx = *ctx; |
2682 | new_ctx.ctor = build_constructor (type, NULL); | |
2683 | new_ctx.object = NULL_TREE; | |
2684 | ctx = &new_ctx; | |
2685 | }; | |
2686 | verify_ctor_sanity (ctx, type); | |
cf72f34d | 2687 | vec<constructor_elt, va_gc> **p = &CONSTRUCTOR_ELTS (ctx->ctor); |
2688 | vec_alloc (*p, vec_safe_length (v)); | |
2689 | ||
58b0f9ce | 2690 | unsigned i; |
2691 | tree index, value; | |
2692 | bool constant_p = true; | |
2693 | bool side_effects_p = false; | |
cf72f34d | 2694 | FOR_EACH_CONSTRUCTOR_ELT (v, i, index, value) |
09b42213 | 2695 | { |
5ae773e4 | 2696 | tree orig_value = value; |
cf72f34d | 2697 | init_subob_ctx (ctx, new_ctx, index, value); |
2698 | if (new_ctx.ctor != ctx->ctor) | |
2699 | /* If we built a new CONSTRUCTOR, attach it now so that other | |
2700 | initializers can refer to it. */ | |
2701 | CONSTRUCTOR_APPEND_ELT (*p, index, new_ctx.ctor); | |
2702 | tree elt = cxx_eval_constant_expression (&new_ctx, value, | |
1227ba74 | 2703 | lval, |
b2a43197 | 2704 | non_constant_p, overflow_p); |
09b42213 | 2705 | /* Don't VERIFY_CONSTANT here. */ |
f83e6885 | 2706 | if (ctx->quiet && *non_constant_p) |
cf72f34d | 2707 | break; |
5ae773e4 | 2708 | if (elt != orig_value) |
09b42213 | 2709 | changed = true; |
58b0f9ce | 2710 | |
2711 | if (!TREE_CONSTANT (elt)) | |
2712 | constant_p = false; | |
2713 | if (TREE_SIDE_EFFECTS (elt)) | |
2714 | side_effects_p = true; | |
cf72f34d | 2715 | if (index && TREE_CODE (index) == COMPONENT_REF) |
09b42213 | 2716 | { |
2717 | /* This is an initialization of a vfield inside a base | |
2718 | subaggregate that we already initialized; push this | |
2719 | initialization into the previous initialization. */ | |
cf72f34d | 2720 | constructor_elt *inner = base_field_constructor_elt (*p, index); |
09b42213 | 2721 | inner->value = elt; |
cf72f34d | 2722 | changed = true; |
09b42213 | 2723 | } |
cf72f34d | 2724 | else if (index |
2725 | && (TREE_CODE (index) == NOP_EXPR | |
2726 | || TREE_CODE (index) == POINTER_PLUS_EXPR)) | |
09b42213 | 2727 | { |
2728 | /* This is an initializer for an empty base; now that we've | |
2729 | checked that it's constant, we can ignore it. */ | |
cf72f34d | 2730 | gcc_assert (is_empty_class (TREE_TYPE (TREE_TYPE (index)))); |
2731 | changed = true; | |
2732 | } | |
2733 | else if (new_ctx.ctor != ctx->ctor) | |
2734 | { | |
2735 | /* We appended this element above; update the value. */ | |
2736 | gcc_assert ((*p)->last().index == index); | |
2737 | (*p)->last().value = elt; | |
09b42213 | 2738 | } |
2739 | else | |
cf72f34d | 2740 | CONSTRUCTOR_APPEND_ELT (*p, index, elt); |
09b42213 | 2741 | } |
2742 | if (*non_constant_p || !changed) | |
cf72f34d | 2743 | return t; |
2744 | t = ctx->ctor; | |
2745 | /* We're done building this CONSTRUCTOR, so now we can interpret an | |
2746 | element without an explicit initializer as value-initialized. */ | |
2747 | CONSTRUCTOR_NO_IMPLICIT_ZERO (t) = false; | |
58b0f9ce | 2748 | TREE_CONSTANT (t) = constant_p; |
2749 | TREE_SIDE_EFFECTS (t) = side_effects_p; | |
68464393 | 2750 | if (VECTOR_TYPE_P (type)) |
09b42213 | 2751 | t = fold (t); |
2752 | return t; | |
2753 | } | |
2754 | ||
2755 | /* Subroutine of cxx_eval_constant_expression. | |
2756 | The expression tree T is a VEC_INIT_EXPR which denotes the desired | |
2757 | initialization of a non-static data member of array type. Reduce it to a | |
2758 | CONSTRUCTOR. | |
2759 | ||
2760 | Note that apart from value-initialization (when VALUE_INIT is true), | |
2761 | this is only intended to support value-initialization and the | |
2762 | initializations done by defaulted constructors for classes with | |
2763 | non-static data members of array type. In this case, VEC_INIT_EXPR_INIT | |
2764 | will either be NULL_TREE for the default constructor, or a COMPONENT_REF | |
2765 | for the copy/move constructor. */ | |
2766 | ||
2767 | static tree | |
cf72f34d | 2768 | cxx_eval_vec_init_1 (const constexpr_ctx *ctx, tree atype, tree init, |
1227ba74 | 2769 | bool value_init, bool lval, |
09b42213 | 2770 | bool *non_constant_p, bool *overflow_p) |
2771 | { | |
2772 | tree elttype = TREE_TYPE (atype); | |
3e520b97 | 2773 | unsigned HOST_WIDE_INT max = tree_to_uhwi (array_type_nelts_top (atype)); |
cf72f34d | 2774 | verify_ctor_sanity (ctx, atype); |
2775 | vec<constructor_elt, va_gc> **p = &CONSTRUCTOR_ELTS (ctx->ctor); | |
2776 | vec_alloc (*p, max + 1); | |
09b42213 | 2777 | bool pre_init = false; |
3e520b97 | 2778 | unsigned HOST_WIDE_INT i; |
09b42213 | 2779 | |
2780 | /* For the default constructor, build up a call to the default | |
2781 | constructor of the element type. We only need to handle class types | |
2782 | here, as for a constructor to be constexpr, all members must be | |
2783 | initialized, which for a defaulted default constructor means they must | |
2784 | be of a class type with a constexpr default constructor. */ | |
2785 | if (TREE_CODE (elttype) == ARRAY_TYPE) | |
2786 | /* We only do this at the lowest level. */; | |
2787 | else if (value_init) | |
2788 | { | |
2789 | init = build_value_init (elttype, tf_warning_or_error); | |
09b42213 | 2790 | pre_init = true; |
2791 | } | |
2792 | else if (!init) | |
2793 | { | |
2794 | vec<tree, va_gc> *argvec = make_tree_vector (); | |
2795 | init = build_special_member_call (NULL_TREE, complete_ctor_identifier, | |
2796 | &argvec, elttype, LOOKUP_NORMAL, | |
2797 | tf_warning_or_error); | |
2798 | release_tree_vector (argvec); | |
9c96033c | 2799 | init = build_aggr_init_expr (TREE_TYPE (init), init); |
09b42213 | 2800 | pre_init = true; |
2801 | } | |
2802 | ||
3e520b97 | 2803 | for (i = 0; i < max; ++i) |
09b42213 | 2804 | { |
2805 | tree idx = build_int_cst (size_type_node, i); | |
2806 | tree eltinit; | |
d9377ad5 | 2807 | bool reuse = false; |
cf72f34d | 2808 | constexpr_ctx new_ctx; |
2809 | init_subob_ctx (ctx, new_ctx, idx, pre_init ? init : elttype); | |
2810 | if (new_ctx.ctor != ctx->ctor) | |
2811 | CONSTRUCTOR_APPEND_ELT (*p, idx, new_ctx.ctor); | |
09b42213 | 2812 | if (TREE_CODE (elttype) == ARRAY_TYPE) |
2813 | { | |
2814 | /* A multidimensional array; recurse. */ | |
2815 | if (value_init || init == NULL_TREE) | |
d9377ad5 | 2816 | { |
2817 | eltinit = NULL_TREE; | |
2818 | reuse = i == 0; | |
2819 | } | |
09b42213 | 2820 | else |
2821 | eltinit = cp_build_array_ref (input_location, init, idx, | |
2822 | tf_warning_or_error); | |
cf72f34d | 2823 | eltinit = cxx_eval_vec_init_1 (&new_ctx, elttype, eltinit, value_init, |
1227ba74 | 2824 | lval, |
09b42213 | 2825 | non_constant_p, overflow_p); |
2826 | } | |
2827 | else if (pre_init) | |
2828 | { | |
2829 | /* Initializing an element using value or default initialization | |
2830 | we just pre-built above. */ | |
d9377ad5 | 2831 | eltinit = cxx_eval_constant_expression (&new_ctx, init, lval, |
2832 | non_constant_p, overflow_p); | |
2833 | reuse = i == 0; | |
09b42213 | 2834 | } |
2835 | else | |
2836 | { | |
2837 | /* Copying an element. */ | |
2838 | gcc_assert (same_type_ignoring_top_level_qualifiers_p | |
2839 | (atype, TREE_TYPE (init))); | |
2840 | eltinit = cp_build_array_ref (input_location, init, idx, | |
2841 | tf_warning_or_error); | |
18bede74 | 2842 | if (!lvalue_p (init)) |
09b42213 | 2843 | eltinit = move (eltinit); |
2844 | eltinit = force_rvalue (eltinit, tf_warning_or_error); | |
cf72f34d | 2845 | eltinit = (cxx_eval_constant_expression |
1227ba74 | 2846 | (&new_ctx, eltinit, lval, |
b2a43197 | 2847 | non_constant_p, overflow_p)); |
09b42213 | 2848 | } |
f83e6885 | 2849 | if (*non_constant_p && !ctx->quiet) |
cf72f34d | 2850 | break; |
2851 | if (new_ctx.ctor != ctx->ctor) | |
2852 | { | |
2853 | /* We appended this element above; update the value. */ | |
2854 | gcc_assert ((*p)->last().index == idx); | |
2855 | (*p)->last().value = eltinit; | |
2856 | } | |
2857 | else | |
2858 | CONSTRUCTOR_APPEND_ELT (*p, idx, eltinit); | |
d9377ad5 | 2859 | /* Reuse the result of cxx_eval_constant_expression call |
2860 | from the first iteration to all others if it is a constant | |
2861 | initializer that doesn't require relocations. */ | |
2862 | if (reuse | |
2863 | && max > 1 | |
2864 | && (initializer_constant_valid_p (eltinit, TREE_TYPE (eltinit)) | |
2865 | == null_pointer_node)) | |
2866 | { | |
2867 | if (new_ctx.ctor != ctx->ctor) | |
2868 | eltinit = new_ctx.ctor; | |
2869 | for (i = 1; i < max; ++i) | |
2870 | { | |
2871 | idx = build_int_cst (size_type_node, i); | |
e283bb4f | 2872 | CONSTRUCTOR_APPEND_ELT (*p, idx, unshare_constructor (eltinit)); |
d9377ad5 | 2873 | } |
2874 | break; | |
2875 | } | |
09b42213 | 2876 | } |
2877 | ||
2878 | if (!*non_constant_p) | |
2879 | { | |
cf72f34d | 2880 | init = ctx->ctor; |
2881 | CONSTRUCTOR_NO_IMPLICIT_ZERO (init) = false; | |
09b42213 | 2882 | } |
09b42213 | 2883 | return init; |
2884 | } | |
2885 | ||
2886 | static tree | |
cf72f34d | 2887 | cxx_eval_vec_init (const constexpr_ctx *ctx, tree t, |
1227ba74 | 2888 | bool lval, |
09b42213 | 2889 | bool *non_constant_p, bool *overflow_p) |
2890 | { | |
2891 | tree atype = TREE_TYPE (t); | |
2892 | tree init = VEC_INIT_EXPR_INIT (t); | |
cf72f34d | 2893 | tree r = cxx_eval_vec_init_1 (ctx, atype, init, |
09b42213 | 2894 | VEC_INIT_EXPR_VALUE_INIT (t), |
1227ba74 | 2895 | lval, non_constant_p, overflow_p); |
09b42213 | 2896 | if (*non_constant_p) |
2897 | return t; | |
2898 | else | |
2899 | return r; | |
2900 | } | |
2901 | ||
2902 | /* A less strict version of fold_indirect_ref_1, which requires cv-quals to | |
2903 | match. We want to be less strict for simple *& folding; if we have a | |
2904 | non-const temporary that we access through a const pointer, that should | |
2905 | work. We handle this here rather than change fold_indirect_ref_1 | |
2906 | because we're dealing with things like ADDR_EXPR of INTEGER_CST which | |
2907 | don't really make sense outside of constant expression evaluation. Also | |
2908 | we want to allow folding to COMPONENT_REF, which could cause trouble | |
2909 | with TBAA in fold_indirect_ref_1. | |
2910 | ||
2911 | Try to keep this function synced with fold_indirect_ref_1. */ | |
2912 | ||
2913 | static tree | |
2914 | cxx_fold_indirect_ref (location_t loc, tree type, tree op0, bool *empty_base) | |
2915 | { | |
2916 | tree sub, subtype; | |
2917 | ||
2918 | sub = op0; | |
2919 | STRIP_NOPS (sub); | |
2920 | subtype = TREE_TYPE (sub); | |
2921 | if (!POINTER_TYPE_P (subtype)) | |
2922 | return NULL_TREE; | |
2923 | ||
2924 | if (TREE_CODE (sub) == ADDR_EXPR) | |
2925 | { | |
2926 | tree op = TREE_OPERAND (sub, 0); | |
2927 | tree optype = TREE_TYPE (op); | |
2928 | ||
2929 | /* *&CONST_DECL -> to the value of the const decl. */ | |
2930 | if (TREE_CODE (op) == CONST_DECL) | |
2931 | return DECL_INITIAL (op); | |
2932 | /* *&p => p; make sure to handle *&"str"[cst] here. */ | |
c4118b0c | 2933 | if (same_type_ignoring_top_level_qualifiers_p (optype, type) |
2934 | /* Also handle the case where the desired type is an array of unknown | |
2935 | bounds because the variable has had its bounds deduced since the | |
2936 | ADDR_EXPR was created. */ | |
2937 | || (TREE_CODE (type) == ARRAY_TYPE | |
2938 | && TREE_CODE (optype) == ARRAY_TYPE | |
2939 | && TYPE_DOMAIN (type) == NULL_TREE | |
2940 | && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (optype), | |
2941 | TREE_TYPE (type)))) | |
09b42213 | 2942 | { |
2943 | tree fop = fold_read_from_constant_string (op); | |
2944 | if (fop) | |
2945 | return fop; | |
2946 | else | |
2947 | return op; | |
2948 | } | |
2949 | /* *(foo *)&fooarray => fooarray[0] */ | |
2950 | else if (TREE_CODE (optype) == ARRAY_TYPE | |
2951 | && (same_type_ignoring_top_level_qualifiers_p | |
2952 | (type, TREE_TYPE (optype)))) | |
2953 | { | |
2954 | tree type_domain = TYPE_DOMAIN (optype); | |
2955 | tree min_val = size_zero_node; | |
2956 | if (type_domain && TYPE_MIN_VALUE (type_domain)) | |
2957 | min_val = TYPE_MIN_VALUE (type_domain); | |
2958 | return build4_loc (loc, ARRAY_REF, type, op, min_val, | |
2959 | NULL_TREE, NULL_TREE); | |
2960 | } | |
2961 | /* *(foo *)&complexfoo => __real__ complexfoo */ | |
2962 | else if (TREE_CODE (optype) == COMPLEX_TYPE | |
2963 | && (same_type_ignoring_top_level_qualifiers_p | |
2964 | (type, TREE_TYPE (optype)))) | |
2965 | return fold_build1_loc (loc, REALPART_EXPR, type, op); | |
2966 | /* *(foo *)&vectorfoo => BIT_FIELD_REF<vectorfoo,...> */ | |
76249021 | 2967 | else if (VECTOR_TYPE_P (optype) |
09b42213 | 2968 | && (same_type_ignoring_top_level_qualifiers_p |
2969 | (type, TREE_TYPE (optype)))) | |
2970 | { | |
2971 | tree part_width = TYPE_SIZE (type); | |
2972 | tree index = bitsize_int (0); | |
2973 | return fold_build3_loc (loc, BIT_FIELD_REF, type, op, part_width, index); | |
2974 | } | |
2975 | /* Also handle conversion to an empty base class, which | |
2976 | is represented with a NOP_EXPR. */ | |
2977 | else if (is_empty_class (type) | |
2978 | && CLASS_TYPE_P (optype) | |
2979 | && DERIVED_FROM_P (type, optype)) | |
2980 | { | |
2981 | *empty_base = true; | |
2982 | return op; | |
2983 | } | |
2984 | /* *(foo *)&struct_with_foo_field => COMPONENT_REF */ | |
2985 | else if (RECORD_OR_UNION_TYPE_P (optype)) | |
2986 | { | |
2987 | tree field = TYPE_FIELDS (optype); | |
2988 | for (; field; field = DECL_CHAIN (field)) | |
2989 | if (TREE_CODE (field) == FIELD_DECL | |
a48667ee | 2990 | && TREE_TYPE (field) != error_mark_node |
09b42213 | 2991 | && integer_zerop (byte_position (field)) |
2992 | && (same_type_ignoring_top_level_qualifiers_p | |
2993 | (TREE_TYPE (field), type))) | |
a48667ee | 2994 | return fold_build3 (COMPONENT_REF, type, op, field, NULL_TREE); |
09b42213 | 2995 | } |
2996 | } | |
2997 | else if (TREE_CODE (sub) == POINTER_PLUS_EXPR | |
2998 | && TREE_CODE (TREE_OPERAND (sub, 1)) == INTEGER_CST) | |
2999 | { | |
3000 | tree op00 = TREE_OPERAND (sub, 0); | |
3001 | tree op01 = TREE_OPERAND (sub, 1); | |
3002 | ||
3003 | STRIP_NOPS (op00); | |
3004 | if (TREE_CODE (op00) == ADDR_EXPR) | |
3005 | { | |
3006 | tree op00type; | |
3007 | op00 = TREE_OPERAND (op00, 0); | |
3008 | op00type = TREE_TYPE (op00); | |
3009 | ||
3010 | /* ((foo*)&vectorfoo)[1] => BIT_FIELD_REF<vectorfoo,...> */ | |
76249021 | 3011 | if (VECTOR_TYPE_P (op00type) |
09b42213 | 3012 | && (same_type_ignoring_top_level_qualifiers_p |
3013 | (type, TREE_TYPE (op00type)))) | |
3014 | { | |
3015 | HOST_WIDE_INT offset = tree_to_shwi (op01); | |
3016 | tree part_width = TYPE_SIZE (type); | |
3017 | unsigned HOST_WIDE_INT part_widthi = tree_to_shwi (part_width)/BITS_PER_UNIT; | |
3018 | unsigned HOST_WIDE_INT indexi = offset * BITS_PER_UNIT; | |
3019 | tree index = bitsize_int (indexi); | |
3020 | ||
3021 | if (offset / part_widthi < TYPE_VECTOR_SUBPARTS (op00type)) | |
3022 | return fold_build3_loc (loc, | |
3023 | BIT_FIELD_REF, type, op00, | |
3024 | part_width, index); | |
3025 | ||
3026 | } | |
3027 | /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */ | |
3028 | else if (TREE_CODE (op00type) == COMPLEX_TYPE | |
3029 | && (same_type_ignoring_top_level_qualifiers_p | |
3030 | (type, TREE_TYPE (op00type)))) | |
3031 | { | |
3032 | tree size = TYPE_SIZE_UNIT (type); | |
3033 | if (tree_int_cst_equal (size, op01)) | |
3034 | return fold_build1_loc (loc, IMAGPART_EXPR, type, op00); | |
3035 | } | |
3036 | /* ((foo *)&fooarray)[1] => fooarray[1] */ | |
3037 | else if (TREE_CODE (op00type) == ARRAY_TYPE | |
3038 | && (same_type_ignoring_top_level_qualifiers_p | |
3039 | (type, TREE_TYPE (op00type)))) | |
3040 | { | |
3041 | tree type_domain = TYPE_DOMAIN (op00type); | |
3042 | tree min_val = size_zero_node; | |
3043 | if (type_domain && TYPE_MIN_VALUE (type_domain)) | |
3044 | min_val = TYPE_MIN_VALUE (type_domain); | |
3045 | op01 = size_binop_loc (loc, EXACT_DIV_EXPR, op01, | |
3046 | TYPE_SIZE_UNIT (type)); | |
3047 | op01 = size_binop_loc (loc, PLUS_EXPR, op01, min_val); | |
3048 | return build4_loc (loc, ARRAY_REF, type, op00, op01, | |
3049 | NULL_TREE, NULL_TREE); | |
3050 | } | |
3051 | /* Also handle conversion to an empty base class, which | |
3052 | is represented with a NOP_EXPR. */ | |
3053 | else if (is_empty_class (type) | |
3054 | && CLASS_TYPE_P (op00type) | |
3055 | && DERIVED_FROM_P (type, op00type)) | |
3056 | { | |
3057 | *empty_base = true; | |
3058 | return op00; | |
3059 | } | |
3060 | /* ((foo *)&struct_with_foo_field)[1] => COMPONENT_REF */ | |
3061 | else if (RECORD_OR_UNION_TYPE_P (op00type)) | |
3062 | { | |
3063 | tree field = TYPE_FIELDS (op00type); | |
3064 | for (; field; field = DECL_CHAIN (field)) | |
3065 | if (TREE_CODE (field) == FIELD_DECL | |
a48667ee | 3066 | && TREE_TYPE (field) != error_mark_node |
09b42213 | 3067 | && tree_int_cst_equal (byte_position (field), op01) |
3068 | && (same_type_ignoring_top_level_qualifiers_p | |
3069 | (TREE_TYPE (field), type))) | |
a48667ee | 3070 | return fold_build3 (COMPONENT_REF, type, op00, |
3071 | field, NULL_TREE); | |
09b42213 | 3072 | } |
3073 | } | |
3074 | } | |
3075 | /* *(foo *)fooarrptr => (*fooarrptr)[0] */ | |
3076 | else if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE | |
3077 | && (same_type_ignoring_top_level_qualifiers_p | |
3078 | (type, TREE_TYPE (TREE_TYPE (subtype))))) | |
3079 | { | |
3080 | tree type_domain; | |
3081 | tree min_val = size_zero_node; | |
3082 | tree newsub = cxx_fold_indirect_ref (loc, TREE_TYPE (subtype), sub, NULL); | |
3083 | if (newsub) | |
3084 | sub = newsub; | |
3085 | else | |
3086 | sub = build1_loc (loc, INDIRECT_REF, TREE_TYPE (subtype), sub); | |
3087 | type_domain = TYPE_DOMAIN (TREE_TYPE (sub)); | |
3088 | if (type_domain && TYPE_MIN_VALUE (type_domain)) | |
3089 | min_val = TYPE_MIN_VALUE (type_domain); | |
3090 | return build4_loc (loc, ARRAY_REF, type, sub, min_val, NULL_TREE, | |
3091 | NULL_TREE); | |
3092 | } | |
3093 | ||
3094 | return NULL_TREE; | |
3095 | } | |
3096 | ||
3097 | static tree | |
cf72f34d | 3098 | cxx_eval_indirect_ref (const constexpr_ctx *ctx, tree t, |
1227ba74 | 3099 | bool lval, |
09b42213 | 3100 | bool *non_constant_p, bool *overflow_p) |
3101 | { | |
3102 | tree orig_op0 = TREE_OPERAND (t, 0); | |
09b42213 | 3103 | bool empty_base = false; |
09b42213 | 3104 | |
d2c63826 | 3105 | /* We can handle a MEM_REF like an INDIRECT_REF, if MEM_REF's second |
3106 | operand is an integer-zero. Otherwise reject the MEM_REF for now. */ | |
3107 | ||
3108 | if (TREE_CODE (t) == MEM_REF | |
3109 | && (!TREE_OPERAND (t, 1) || !integer_zerop (TREE_OPERAND (t, 1)))) | |
3110 | { | |
3111 | gcc_assert (ctx->quiet); | |
3112 | *non_constant_p = true; | |
3113 | return t; | |
3114 | } | |
3115 | ||
7e0f3388 | 3116 | /* First try to simplify it directly. */ |
3117 | tree r = cxx_fold_indirect_ref (EXPR_LOCATION (t), TREE_TYPE (t), orig_op0, | |
3118 | &empty_base); | |
3119 | if (!r) | |
09b42213 | 3120 | { |
7e0f3388 | 3121 | /* If that didn't work, evaluate the operand first. */ |
3122 | tree op0 = cxx_eval_constant_expression (ctx, orig_op0, | |
3123 | /*lval*/false, non_constant_p, | |
3124 | overflow_p); | |
3125 | /* Don't VERIFY_CONSTANT here. */ | |
3126 | if (*non_constant_p) | |
3127 | return t; | |
3128 | ||
cb768824 | 3129 | if (!lval && integer_zerop (op0)) |
3130 | { | |
3131 | if (!ctx->quiet) | |
3132 | error ("dereferencing a null pointer"); | |
3133 | *non_constant_p = true; | |
3134 | return t; | |
3135 | } | |
3136 | ||
7e0f3388 | 3137 | r = cxx_fold_indirect_ref (EXPR_LOCATION (t), TREE_TYPE (t), op0, |
3138 | &empty_base); | |
3139 | if (r == NULL_TREE) | |
09b42213 | 3140 | { |
3141 | /* We couldn't fold to a constant value. Make sure it's not | |
3142 | something we should have been able to fold. */ | |
7e0f3388 | 3143 | tree sub = op0; |
3144 | STRIP_NOPS (sub); | |
3145 | if (TREE_CODE (sub) == ADDR_EXPR) | |
3146 | { | |
3147 | gcc_assert (!same_type_ignoring_top_level_qualifiers_p | |
3148 | (TREE_TYPE (TREE_TYPE (sub)), TREE_TYPE (t))); | |
3149 | /* DR 1188 says we don't have to deal with this. */ | |
3150 | if (!ctx->quiet) | |
3151 | error ("accessing value of %qE through a %qT glvalue in a " | |
3152 | "constant expression", build_fold_indirect_ref (sub), | |
3153 | TREE_TYPE (t)); | |
3154 | *non_constant_p = true; | |
3155 | return t; | |
3156 | } | |
3157 | ||
3158 | if (lval && op0 != orig_op0) | |
3159 | return build1 (INDIRECT_REF, TREE_TYPE (t), op0); | |
3160 | if (!lval) | |
3161 | VERIFY_CONSTANT (t); | |
09b42213 | 3162 | return t; |
3163 | } | |
3164 | } | |
3165 | ||
7e0f3388 | 3166 | r = cxx_eval_constant_expression (ctx, r, |
3167 | lval, non_constant_p, overflow_p); | |
3168 | if (*non_constant_p) | |
3169 | return t; | |
3170 | ||
ce4ffd9e | 3171 | /* If we're pulling out the value of an empty base, just return an empty |
09b42213 | 3172 | CONSTRUCTOR. */ |
1227ba74 | 3173 | if (empty_base && !lval) |
09b42213 | 3174 | { |
09b42213 | 3175 | r = build_constructor (TREE_TYPE (t), NULL); |
3176 | TREE_CONSTANT (r) = true; | |
3177 | } | |
3178 | ||
09b42213 | 3179 | return r; |
3180 | } | |
3181 | ||
3182 | /* Complain about R, a VAR_DECL, not being usable in a constant expression. | |
3183 | Shared between potential_constant_expression and | |
3184 | cxx_eval_constant_expression. */ | |
3185 | ||
3186 | static void | |
3187 | non_const_var_error (tree r) | |
3188 | { | |
3189 | tree type = TREE_TYPE (r); | |
3190 | error ("the value of %qD is not usable in a constant " | |
3191 | "expression", r); | |
3192 | /* Avoid error cascade. */ | |
3193 | if (DECL_INITIAL (r) == error_mark_node) | |
3194 | return; | |
3195 | if (DECL_DECLARED_CONSTEXPR_P (r)) | |
3196 | inform (DECL_SOURCE_LOCATION (r), | |
3197 | "%qD used in its own initializer", r); | |
3198 | else if (INTEGRAL_OR_ENUMERATION_TYPE_P (type)) | |
3199 | { | |
3200 | if (!CP_TYPE_CONST_P (type)) | |
3201 | inform (DECL_SOURCE_LOCATION (r), | |
3202 | "%q#D is not const", r); | |
3203 | else if (CP_TYPE_VOLATILE_P (type)) | |
3204 | inform (DECL_SOURCE_LOCATION (r), | |
3205 | "%q#D is volatile", r); | |
3206 | else if (!DECL_INITIAL (r) | |
c8e3e744 | 3207 | || !TREE_CONSTANT (DECL_INITIAL (r)) |
3208 | || !DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r)) | |
09b42213 | 3209 | inform (DECL_SOURCE_LOCATION (r), |
3210 | "%qD was not initialized with a constant " | |
3211 | "expression", r); | |
3212 | else | |
3213 | gcc_unreachable (); | |
3214 | } | |
ac6641ca | 3215 | else if (TREE_CODE (type) == REFERENCE_TYPE) |
3216 | inform (DECL_SOURCE_LOCATION (r), | |
3217 | "%qD was not initialized with a constant " | |
3218 | "expression", r); | |
09b42213 | 3219 | else |
3220 | { | |
3221 | if (cxx_dialect >= cxx11 && !DECL_DECLARED_CONSTEXPR_P (r)) | |
3222 | inform (DECL_SOURCE_LOCATION (r), | |
3223 | "%qD was not declared %<constexpr%>", r); | |
3224 | else | |
3225 | inform (DECL_SOURCE_LOCATION (r), | |
3226 | "%qD does not have integral or enumeration type", | |
3227 | r); | |
3228 | } | |
3229 | } | |
3230 | ||
3231 | /* Subroutine of cxx_eval_constant_expression. | |
3232 | Like cxx_eval_unary_expression, except for trinary expressions. */ | |
3233 | ||
3234 | static tree | |
cf72f34d | 3235 | cxx_eval_trinary_expression (const constexpr_ctx *ctx, tree t, |
1227ba74 | 3236 | bool lval, |
09b42213 | 3237 | bool *non_constant_p, bool *overflow_p) |
3238 | { | |
3239 | int i; | |
3240 | tree args[3]; | |
3241 | tree val; | |
3242 | ||
3243 | for (i = 0; i < 3; i++) | |
3244 | { | |
cf72f34d | 3245 | args[i] = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, i), |
1227ba74 | 3246 | lval, |
b2a43197 | 3247 | non_constant_p, overflow_p); |
09b42213 | 3248 | VERIFY_CONSTANT (args[i]); |
3249 | } | |
3250 | ||
3251 | val = fold_ternary_loc (EXPR_LOCATION (t), TREE_CODE (t), TREE_TYPE (t), | |
3252 | args[0], args[1], args[2]); | |
3253 | if (val == NULL_TREE) | |
3254 | return t; | |
3255 | VERIFY_CONSTANT (val); | |
3256 | return val; | |
3257 | } | |
3258 | ||
33603066 | 3259 | /* True if T was declared in a function declared to be constexpr, and |
3260 | therefore potentially constant in C++14. */ | |
3261 | ||
09b42213 | 3262 | bool |
3263 | var_in_constexpr_fn (tree t) | |
3264 | { | |
3265 | tree ctx = DECL_CONTEXT (t); | |
33603066 | 3266 | return (ctx && TREE_CODE (ctx) == FUNCTION_DECL |
09b42213 | 3267 | && DECL_DECLARED_CONSTEXPR_P (ctx)); |
3268 | } | |
3269 | ||
33603066 | 3270 | /* True if T was declared in a function that might be constexpr: either a |
3271 | function that was declared constexpr, or a C++17 lambda op(). */ | |
3272 | ||
3273 | bool | |
3274 | var_in_maybe_constexpr_fn (tree t) | |
3275 | { | |
3276 | if (cxx_dialect >= cxx1z | |
3277 | && DECL_FUNCTION_SCOPE_P (t) | |
3278 | && LAMBDA_FUNCTION_P (DECL_CONTEXT (t))) | |
3279 | return true; | |
3280 | return var_in_constexpr_fn (t); | |
3281 | } | |
3282 | ||
93312944 | 3283 | /* We're assigning INIT to TARGET. In do_build_copy_constructor and |
3284 | build_over_call we implement trivial copy of a class with tail padding using | |
3285 | assignment of character arrays, which is valid in normal code, but not in | |
3286 | constexpr evaluation. We don't need to worry about clobbering tail padding | |
3287 | in constexpr evaluation, so strip the type punning. */ | |
3288 | ||
3289 | static void | |
3290 | maybe_simplify_trivial_copy (tree &target, tree &init) | |
3291 | { | |
3292 | if (TREE_CODE (target) == MEM_REF | |
3293 | && TREE_CODE (init) == MEM_REF | |
3294 | && TREE_TYPE (target) == TREE_TYPE (init) | |
3295 | && TREE_CODE (TREE_TYPE (target)) == ARRAY_TYPE | |
3296 | && TREE_TYPE (TREE_TYPE (target)) == unsigned_char_type_node) | |
3297 | { | |
3298 | target = build_fold_indirect_ref (TREE_OPERAND (target, 0)); | |
3299 | init = build_fold_indirect_ref (TREE_OPERAND (init, 0)); | |
3300 | } | |
3301 | } | |
3302 | ||
9c96033c | 3303 | /* Evaluate an INIT_EXPR or MODIFY_EXPR. */ |
3304 | ||
3305 | static tree | |
3306 | cxx_eval_store_expression (const constexpr_ctx *ctx, tree t, | |
1227ba74 | 3307 | bool lval, |
9c96033c | 3308 | bool *non_constant_p, bool *overflow_p) |
3309 | { | |
3310 | constexpr_ctx new_ctx = *ctx; | |
3311 | ||
8a36d0ec | 3312 | tree init = TREE_OPERAND (t, 1); |
3313 | if (TREE_CLOBBER_P (init)) | |
3314 | /* Just ignore clobbers. */ | |
3315 | return void_node; | |
3316 | ||
9c96033c | 3317 | /* First we figure out where we're storing to. */ |
3318 | tree target = TREE_OPERAND (t, 0); | |
93312944 | 3319 | |
3320 | maybe_simplify_trivial_copy (target, init); | |
3321 | ||
9db9fc38 | 3322 | tree type = TREE_TYPE (target); |
9c96033c | 3323 | target = cxx_eval_constant_expression (ctx, target, |
f83e6885 | 3324 | true, |
b2a43197 | 3325 | non_constant_p, overflow_p); |
9c96033c | 3326 | if (*non_constant_p) |
3327 | return t; | |
3328 | ||
cf3cefc9 | 3329 | /* cxx_eval_array_reference for lval = true allows references one past |
3330 | end of array, because it does not know if it is just taking address | |
3331 | (which is valid), or actual dereference. Here we know it is | |
3332 | a dereference, so diagnose it here. */ | |
3333 | for (tree probe = target; probe; ) | |
3334 | { | |
3335 | switch (TREE_CODE (probe)) | |
3336 | { | |
3337 | case ARRAY_REF: | |
3338 | tree nelts, ary; | |
3339 | ary = TREE_OPERAND (probe, 0); | |
3340 | if (TREE_CODE (TREE_TYPE (ary)) == ARRAY_TYPE) | |
3341 | nelts = array_type_nelts_top (TREE_TYPE (ary)); | |
3342 | else if (VECTOR_TYPE_P (TREE_TYPE (ary))) | |
3343 | nelts = size_int (TYPE_VECTOR_SUBPARTS (TREE_TYPE (ary))); | |
3344 | else | |
3345 | gcc_unreachable (); | |
3346 | nelts = cxx_eval_constant_expression (ctx, nelts, false, | |
3347 | non_constant_p, overflow_p); | |
3348 | VERIFY_CONSTANT (nelts); | |
3349 | gcc_assert (TREE_CODE (nelts) == INTEGER_CST | |
3350 | && TREE_CODE (TREE_OPERAND (probe, 1)) == INTEGER_CST); | |
3351 | if (wi::eq_p (TREE_OPERAND (probe, 1), nelts)) | |
3352 | { | |
3353 | diag_array_subscript (ctx, ary, TREE_OPERAND (probe, 1)); | |
3354 | *non_constant_p = true; | |
3355 | return t; | |
3356 | } | |
3357 | /* FALLTHRU */ | |
3358 | ||
3359 | case BIT_FIELD_REF: | |
3360 | case COMPONENT_REF: | |
3361 | probe = TREE_OPERAND (probe, 0); | |
3362 | continue; | |
3363 | ||
3364 | default: | |
3365 | probe = NULL_TREE; | |
3366 | continue; | |
3367 | } | |
3368 | } | |
3369 | ||
9db9fc38 | 3370 | if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (target), type)) |
3371 | { | |
3372 | /* For initialization of an empty base, the original target will be | |
3373 | *(base*)this, which the above evaluation resolves to the object | |
3374 | argument, which has the derived type rather than the base type. In | |
3375 | this situation, just evaluate the initializer and return, since | |
3376 | there's no actual data to store. */ | |
3377 | gcc_assert (is_empty_class (type)); | |
3378 | return cxx_eval_constant_expression (ctx, init, false, | |
3379 | non_constant_p, overflow_p); | |
3380 | } | |
3381 | ||
9c96033c | 3382 | /* And then find the underlying variable. */ |
3383 | vec<tree,va_gc> *refs = make_tree_vector(); | |
3384 | tree object = NULL_TREE; | |
3385 | for (tree probe = target; object == NULL_TREE; ) | |
3386 | { | |
3387 | switch (TREE_CODE (probe)) | |
3388 | { | |
3389 | case BIT_FIELD_REF: | |
3390 | case COMPONENT_REF: | |
3391 | case ARRAY_REF: | |
3392 | vec_safe_push (refs, TREE_OPERAND (probe, 1)); | |
3393 | vec_safe_push (refs, TREE_TYPE (probe)); | |
3394 | probe = TREE_OPERAND (probe, 0); | |
3395 | break; | |
3396 | ||
3397 | default: | |
3398 | object = probe; | |
9c96033c | 3399 | } |
3400 | } | |
3401 | ||
3402 | /* And then find/build up our initializer for the path to the subobject | |
3403 | we're initializing. */ | |
6fe83e54 | 3404 | tree *valp; |
43b7271d | 3405 | if (object == ctx->object && VAR_P (object) |
3406 | && DECL_NAME (object) && ctx->call == NULL) | |
3407 | /* The variable we're building up an aggregate initializer for is outside | |
3408 | the constant-expression, so don't evaluate the store. We check | |
3409 | DECL_NAME to handle TARGET_EXPR temporaries, which are fair game. */ | |
3410 | valp = NULL; | |
3411 | else if (DECL_P (object)) | |
6fe83e54 | 3412 | valp = ctx->values->get (object); |
3413 | else | |
3414 | valp = NULL; | |
9c96033c | 3415 | if (!valp) |
3416 | { | |
3417 | /* A constant-expression cannot modify objects from outside the | |
3418 | constant-expression. */ | |
f83e6885 | 3419 | if (!ctx->quiet) |
ea034e2c | 3420 | error ("modification of %qE is not a constant expression", object); |
9c96033c | 3421 | *non_constant_p = true; |
3422 | return t; | |
3423 | } | |
9db9fc38 | 3424 | type = TREE_TYPE (object); |
a02b42fe | 3425 | bool no_zero_init = true; |
58b0f9ce | 3426 | |
3427 | vec<tree,va_gc> *ctors = make_tree_vector (); | |
9c96033c | 3428 | while (!refs->is_empty()) |
3429 | { | |
3430 | if (*valp == NULL_TREE) | |
3431 | { | |
3432 | *valp = build_constructor (type, NULL); | |
a02b42fe | 3433 | CONSTRUCTOR_NO_IMPLICIT_ZERO (*valp) = no_zero_init; |
9c96033c | 3434 | } |
92fe8840 | 3435 | else if (TREE_CODE (*valp) == STRING_CST) |
3436 | { | |
3437 | /* An array was initialized with a string constant, and now | |
3438 | we're writing into one of its elements. Explode the | |
3439 | single initialization into a set of element | |
3440 | initializations. */ | |
3441 | gcc_assert (TREE_CODE (type) == ARRAY_TYPE); | |
3442 | ||
3443 | tree string = *valp; | |
3444 | tree elt_type = TREE_TYPE (type); | |
3445 | unsigned chars_per_elt = (TYPE_PRECISION (elt_type) | |
3446 | / TYPE_PRECISION (char_type_node)); | |
3447 | unsigned num_elts = TREE_STRING_LENGTH (string) / chars_per_elt; | |
3448 | tree ary_ctor = build_constructor (type, NULL); | |
3449 | ||
3450 | vec_safe_reserve (CONSTRUCTOR_ELTS (ary_ctor), num_elts); | |
3451 | for (unsigned ix = 0; ix != num_elts; ix++) | |
3452 | { | |
3453 | constructor_elt elt = | |
3454 | { | |
3455 | build_int_cst (size_type_node, ix), | |
3456 | extract_string_elt (string, chars_per_elt, ix) | |
3457 | }; | |
3458 | CONSTRUCTOR_ELTS (ary_ctor)->quick_push (elt); | |
3459 | } | |
3460 | ||
3461 | *valp = ary_ctor; | |
3462 | } | |
3463 | ||
a02b42fe | 3464 | /* If the value of object is already zero-initialized, any new ctors for |
3465 | subobjects will also be zero-initialized. */ | |
3466 | no_zero_init = CONSTRUCTOR_NO_IMPLICIT_ZERO (*valp); | |
9c96033c | 3467 | |
58b0f9ce | 3468 | vec_safe_push (ctors, *valp); |
3469 | ||
7963b19d | 3470 | enum tree_code code = TREE_CODE (type); |
9c96033c | 3471 | type = refs->pop(); |
7963b19d | 3472 | tree index = refs->pop(); |
9c96033c | 3473 | |
9c96033c | 3474 | constructor_elt *cep = NULL; |
7963b19d | 3475 | if (code == ARRAY_TYPE) |
3476 | { | |
3477 | HOST_WIDE_INT i | |
3478 | = find_array_ctor_elt (*valp, index, /*insert*/true); | |
3479 | gcc_assert (i >= 0); | |
3480 | cep = CONSTRUCTOR_ELT (*valp, i); | |
3481 | gcc_assert (TREE_CODE (cep->index) != RANGE_EXPR); | |
3482 | } | |
3483 | else | |
3484 | { | |
3485 | gcc_assert (TREE_CODE (index) == FIELD_DECL); | |
13ee2de7 | 3486 | |
3487 | /* We must keep the CONSTRUCTOR's ELTS in FIELD order. | |
3488 | Usually we meet initializers in that order, but it is | |
3489 | possible for base types to be placed not in program | |
3490 | order. */ | |
3491 | tree fields = TYPE_FIELDS (DECL_CONTEXT (index)); | |
3492 | unsigned HOST_WIDE_INT idx; | |
3493 | ||
ef782365 | 3494 | if (code == UNION_TYPE && CONSTRUCTOR_NELTS (*valp) |
3495 | && CONSTRUCTOR_ELT (*valp, 0)->index != index) | |
3496 | /* Changing active member. */ | |
3497 | vec_safe_truncate (CONSTRUCTOR_ELTS (*valp), 0); | |
3498 | ||
13ee2de7 | 3499 | for (idx = 0; |
7963b19d | 3500 | vec_safe_iterate (CONSTRUCTOR_ELTS (*valp), idx, &cep); |
13ee2de7 | 3501 | idx++, fields = DECL_CHAIN (fields)) |
7963b19d | 3502 | { |
13ee2de7 | 3503 | if (index == cep->index) |
3504 | goto found; | |
3505 | ||
3506 | /* The field we're initializing must be on the field | |
3507 | list. Look to see if it is present before the | |
3508 | field the current ELT initializes. */ | |
3509 | for (; fields != cep->index; fields = DECL_CHAIN (fields)) | |
3510 | if (index == fields) | |
3511 | goto insert; | |
7963b19d | 3512 | } |
13ee2de7 | 3513 | |
3514 | /* We fell off the end of the CONSTRUCTOR, so insert a new | |
3515 | entry at the end. */ | |
3516 | insert: | |
3517 | { | |
3518 | constructor_elt ce = { index, NULL_TREE }; | |
3519 | ||
3520 | vec_safe_insert (CONSTRUCTOR_ELTS (*valp), idx, ce); | |
3521 | cep = CONSTRUCTOR_ELT (*valp, idx); | |
3522 | } | |
3523 | found:; | |
7963b19d | 3524 | } |
9c96033c | 3525 | valp = &cep->value; |
3526 | } | |
3527 | release_tree_vector (refs); | |
3528 | ||
469dc5a6 | 3529 | if (AGGREGATE_TYPE_P (type) || VECTOR_TYPE_P (type)) |
9c96033c | 3530 | { |
3531 | /* Create a new CONSTRUCTOR in case evaluation of the initializer | |
3532 | wants to modify it. */ | |
469dc5a6 | 3533 | if (*valp == NULL_TREE) |
6cded085 | 3534 | { |
6993e708 | 3535 | *valp = build_constructor (type, NULL); |
3536 | CONSTRUCTOR_NO_IMPLICIT_ZERO (*valp) = no_zero_init; | |
6cded085 | 3537 | } |
6993e708 | 3538 | else if (TREE_CODE (*valp) == PTRMEM_CST) |
3539 | *valp = cplus_expand_constant (*valp); | |
3540 | new_ctx.ctor = *valp; | |
9c96033c | 3541 | new_ctx.object = target; |
3542 | } | |
3543 | ||
8a36d0ec | 3544 | init = cxx_eval_constant_expression (&new_ctx, init, false, |
3545 | non_constant_p, overflow_p); | |
7b9f713d | 3546 | /* Don't share a CONSTRUCTOR that might be changed later. */ |
e283bb4f | 3547 | init = unshare_constructor (init); |
9c96033c | 3548 | if (target == object) |
5579a199 | 3549 | /* The hash table might have moved since the get earlier. */ |
3550 | valp = ctx->values->get (object); | |
3551 | ||
3552 | if (TREE_CODE (init) == CONSTRUCTOR) | |
469dc5a6 | 3553 | { |
5579a199 | 3554 | /* An outer ctx->ctor might be pointing to *valp, so replace |
3555 | its contents. */ | |
3556 | CONSTRUCTOR_ELTS (*valp) = CONSTRUCTOR_ELTS (init); | |
3557 | TREE_CONSTANT (*valp) = TREE_CONSTANT (init); | |
3558 | TREE_SIDE_EFFECTS (*valp) = TREE_SIDE_EFFECTS (init); | |
b9786e35 | 3559 | CONSTRUCTOR_NO_IMPLICIT_ZERO (*valp) |
3560 | = CONSTRUCTOR_NO_IMPLICIT_ZERO (init); | |
469dc5a6 | 3561 | } |
9c96033c | 3562 | else |
5579a199 | 3563 | *valp = init; |
58b0f9ce | 3564 | |
5579a199 | 3565 | /* Update TREE_CONSTANT and TREE_SIDE_EFFECTS on enclosing |
3566 | CONSTRUCTORs, if any. */ | |
3567 | tree elt; | |
3568 | unsigned i; | |
3569 | bool c = TREE_CONSTANT (init); | |
3570 | bool s = TREE_SIDE_EFFECTS (init); | |
3571 | if (!c || s) | |
3572 | FOR_EACH_VEC_SAFE_ELT (ctors, i, elt) | |
3573 | { | |
3574 | if (!c) | |
3575 | TREE_CONSTANT (elt) = false; | |
3576 | if (s) | |
3577 | TREE_SIDE_EFFECTS (elt) = true; | |
3578 | } | |
58b0f9ce | 3579 | release_tree_vector (ctors); |
9c96033c | 3580 | |
3581 | if (*non_constant_p) | |
3582 | return t; | |
1227ba74 | 3583 | else if (lval) |
9c96033c | 3584 | return target; |
3585 | else | |
dfac7dd2 | 3586 | return init; |
9c96033c | 3587 | } |
3588 | ||
3589 | /* Evaluate a ++ or -- expression. */ | |
3590 | ||
3591 | static tree | |
3592 | cxx_eval_increment_expression (const constexpr_ctx *ctx, tree t, | |
1227ba74 | 3593 | bool lval, |
9c96033c | 3594 | bool *non_constant_p, bool *overflow_p) |
3595 | { | |
3596 | enum tree_code code = TREE_CODE (t); | |
3597 | tree type = TREE_TYPE (t); | |
3598 | tree op = TREE_OPERAND (t, 0); | |
3599 | tree offset = TREE_OPERAND (t, 1); | |
3600 | gcc_assert (TREE_CONSTANT (offset)); | |
3601 | ||
3602 | /* The operand as an lvalue. */ | |
f83e6885 | 3603 | op = cxx_eval_constant_expression (ctx, op, true, |
b2a43197 | 3604 | non_constant_p, overflow_p); |
9c96033c | 3605 | |
3606 | /* The operand as an rvalue. */ | |
3607 | tree val = rvalue (op); | |
f83e6885 | 3608 | val = cxx_eval_constant_expression (ctx, val, false, |
b2a43197 | 3609 | non_constant_p, overflow_p); |
35f2c28f | 3610 | /* Don't VERIFY_CONSTANT if this might be dealing with a pointer to |
3611 | a local array in a constexpr function. */ | |
3612 | bool ptr = POINTER_TYPE_P (TREE_TYPE (val)); | |
3613 | if (!ptr) | |
3614 | VERIFY_CONSTANT (val); | |
9c96033c | 3615 | |
3616 | /* The modified value. */ | |
3617 | bool inc = (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR); | |
c8a8f7ad | 3618 | tree mod; |
3619 | if (POINTER_TYPE_P (type)) | |
3620 | { | |
3621 | /* The middle end requires pointers to use POINTER_PLUS_EXPR. */ | |
3622 | offset = convert_to_ptrofftype (offset); | |
3623 | if (!inc) | |
3624 | offset = fold_build1 (NEGATE_EXPR, TREE_TYPE (offset), offset); | |
3625 | mod = fold_build2 (POINTER_PLUS_EXPR, type, val, offset); | |
3626 | } | |
3627 | else | |
3628 | mod = fold_build2 (inc ? PLUS_EXPR : MINUS_EXPR, type, val, offset); | |
35f2c28f | 3629 | if (!ptr) |
3630 | VERIFY_CONSTANT (mod); | |
9c96033c | 3631 | |
3632 | /* Storing the modified value. */ | |
3633 | tree store = build2 (MODIFY_EXPR, type, op, mod); | |
f83e6885 | 3634 | cxx_eval_constant_expression (ctx, store, |
b2a43197 | 3635 | true, non_constant_p, overflow_p); |
9c96033c | 3636 | |
3637 | /* And the value of the expression. */ | |
3638 | if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR) | |
3639 | { | |
3640 | /* Prefix ops are lvalues. */ | |
1227ba74 | 3641 | if (lval) |
9c96033c | 3642 | return op; |
3643 | else | |
3644 | /* But we optimize when the caller wants an rvalue. */ | |
3645 | return mod; | |
3646 | } | |
3647 | else | |
3648 | /* Postfix ops are rvalues. */ | |
3649 | return val; | |
3650 | } | |
3651 | ||
00f21715 | 3652 | /* Predicates for the meaning of *jump_target. */ |
3653 | ||
3654 | static bool | |
3655 | returns (tree *jump_target) | |
3656 | { | |
3657 | return *jump_target | |
3658 | && TREE_CODE (*jump_target) == RETURN_EXPR; | |
3659 | } | |
3660 | ||
3661 | static bool | |
3662 | breaks (tree *jump_target) | |
3663 | { | |
3664 | return *jump_target | |
cf03ba19 | 3665 | && ((TREE_CODE (*jump_target) == LABEL_DECL |
3666 | && LABEL_DECL_BREAK (*jump_target)) | |
3667 | || TREE_CODE (*jump_target) == EXIT_EXPR); | |
00f21715 | 3668 | } |
3669 | ||
3670 | static bool | |
3671 | continues (tree *jump_target) | |
3672 | { | |
3673 | return *jump_target | |
3674 | && TREE_CODE (*jump_target) == LABEL_DECL | |
3675 | && LABEL_DECL_CONTINUE (*jump_target); | |
3676 | } | |
3677 | ||
3678 | static bool | |
3679 | switches (tree *jump_target) | |
3680 | { | |
3681 | return *jump_target | |
3682 | && TREE_CODE (*jump_target) == INTEGER_CST; | |
3683 | } | |
3684 | ||
3685 | /* Subroutine of cxx_eval_statement_list. Determine whether the statement | |
2a2770c6 | 3686 | STMT matches *jump_target. If we're looking for a case label and we see |
3687 | the default label, note it in ctx->css_state. */ | |
00f21715 | 3688 | |
3689 | static bool | |
2a2770c6 | 3690 | label_matches (const constexpr_ctx *ctx, tree *jump_target, tree stmt) |
00f21715 | 3691 | { |
00f21715 | 3692 | switch (TREE_CODE (*jump_target)) |
3693 | { | |
3694 | case LABEL_DECL: | |
3695 | if (TREE_CODE (stmt) == LABEL_EXPR | |
3696 | && LABEL_EXPR_LABEL (stmt) == *jump_target) | |
3697 | return true; | |
3698 | break; | |
3699 | ||
3700 | case INTEGER_CST: | |
3701 | if (TREE_CODE (stmt) == CASE_LABEL_EXPR) | |
3702 | { | |
2a2770c6 | 3703 | gcc_assert (ctx->css_state != NULL); |
00f21715 | 3704 | if (!CASE_LOW (stmt)) |
2a2770c6 | 3705 | { |
3706 | /* default: should appear just once in a SWITCH_EXPR | |
3707 | body (excluding nested SWITCH_EXPR). */ | |
3708 | gcc_assert (*ctx->css_state != css_default_seen); | |
3709 | /* When evaluating SWITCH_EXPR body for the second time, | |
3710 | return true for the default: label. */ | |
3711 | if (*ctx->css_state == css_default_processing) | |
3712 | return true; | |
3713 | *ctx->css_state = css_default_seen; | |
3714 | } | |
83c375ba | 3715 | else if (CASE_HIGH (stmt)) |
3716 | { | |
3717 | if (tree_int_cst_le (CASE_LOW (stmt), *jump_target) | |
3718 | && tree_int_cst_le (*jump_target, CASE_HIGH (stmt))) | |
3719 | return true; | |
3720 | } | |
00f21715 | 3721 | else if (tree_int_cst_equal (*jump_target, CASE_LOW (stmt))) |
3722 | return true; | |
3723 | } | |
3724 | break; | |
3725 | ||
3726 | default: | |
3727 | gcc_unreachable (); | |
3728 | } | |
3729 | return false; | |
3730 | } | |
3731 | ||
3732 | /* Evaluate a STATEMENT_LIST for side-effects. Handles various jump | |
3733 | semantics, for switch, break, continue, and return. */ | |
3734 | ||
3735 | static tree | |
3736 | cxx_eval_statement_list (const constexpr_ctx *ctx, tree t, | |
00f21715 | 3737 | bool *non_constant_p, bool *overflow_p, |
3738 | tree *jump_target) | |
3739 | { | |
3740 | tree_stmt_iterator i; | |
da7981e0 | 3741 | tree local_target; |
efea7c64 | 3742 | /* In a statement-expression we want to return the last value. |
3743 | For empty statement expression return void_node. */ | |
3744 | tree r = void_node; | |
da7981e0 | 3745 | if (!jump_target) |
3746 | { | |
3747 | local_target = NULL_TREE; | |
3748 | jump_target = &local_target; | |
3749 | } | |
00f21715 | 3750 | for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i)) |
3751 | { | |
00f21715 | 3752 | tree stmt = tsi_stmt (i); |
da7981e0 | 3753 | r = cxx_eval_constant_expression (ctx, stmt, false, |
3754 | non_constant_p, overflow_p, | |
3755 | jump_target); | |
00f21715 | 3756 | if (*non_constant_p) |
3757 | break; | |
3758 | if (returns (jump_target) || breaks (jump_target)) | |
3759 | break; | |
3760 | } | |
da7981e0 | 3761 | return r; |
00f21715 | 3762 | } |
3763 | ||
3764 | /* Evaluate a LOOP_EXPR for side-effects. Handles break and return | |
3765 | semantics; continue semantics are covered by cxx_eval_statement_list. */ | |
3766 | ||
3767 | static tree | |
3768 | cxx_eval_loop_expr (const constexpr_ctx *ctx, tree t, | |
00f21715 | 3769 | bool *non_constant_p, bool *overflow_p, |
3770 | tree *jump_target) | |
3771 | { | |
2631cb67 | 3772 | constexpr_ctx new_ctx = *ctx; |
3773 | ||
00f21715 | 3774 | tree body = TREE_OPERAND (t, 0); |
21483ab7 | 3775 | int count = 0; |
5370eb8d | 3776 | do |
00f21715 | 3777 | { |
2631cb67 | 3778 | hash_set<tree> save_exprs; |
3779 | new_ctx.save_exprs = &save_exprs; | |
3780 | ||
cf03ba19 | 3781 | cxx_eval_constant_expression (&new_ctx, body, /*lval*/false, |
3782 | non_constant_p, overflow_p, jump_target); | |
2631cb67 | 3783 | |
3784 | /* Forget saved values of SAVE_EXPRs. */ | |
3785 | for (hash_set<tree>::iterator iter = save_exprs.begin(); | |
3786 | iter != save_exprs.end(); ++iter) | |
3787 | new_ctx.values->remove (*iter); | |
21483ab7 | 3788 | if (++count >= constexpr_loop_limit) |
3789 | { | |
3790 | if (!ctx->quiet) | |
3791 | error_at (EXPR_LOC_OR_LOC (t, input_location), | |
3792 | "constexpr loop iteration count exceeds limit of %d " | |
3793 | "(use -fconstexpr-loop-limit= to increase the limit)", | |
3794 | constexpr_loop_limit); | |
3795 | *non_constant_p = true; | |
3796 | break; | |
3797 | } | |
00f21715 | 3798 | } |
2a2770c6 | 3799 | while (!returns (jump_target) |
3800 | && !breaks (jump_target) | |
3801 | && !switches (jump_target) | |
3802 | && !*non_constant_p); | |
5370eb8d | 3803 | |
00f21715 | 3804 | if (breaks (jump_target)) |
3805 | *jump_target = NULL_TREE; | |
2631cb67 | 3806 | |
00f21715 | 3807 | return NULL_TREE; |
3808 | } | |
3809 | ||
3810 | /* Evaluate a SWITCH_EXPR for side-effects. Handles switch and break jump | |
3811 | semantics. */ | |
3812 | ||
3813 | static tree | |
3814 | cxx_eval_switch_expr (const constexpr_ctx *ctx, tree t, | |
00f21715 | 3815 | bool *non_constant_p, bool *overflow_p, |
3816 | tree *jump_target) | |
3817 | { | |
3818 | tree cond = TREE_OPERAND (t, 0); | |
f83e6885 | 3819 | cond = cxx_eval_constant_expression (ctx, cond, false, |
b2a43197 | 3820 | non_constant_p, overflow_p); |
00f21715 | 3821 | VERIFY_CONSTANT (cond); |
3822 | *jump_target = cond; | |
3823 | ||
3824 | tree body = TREE_OPERAND (t, 1); | |
2a2770c6 | 3825 | constexpr_ctx new_ctx = *ctx; |
3826 | constexpr_switch_state css = css_default_not_seen; | |
3827 | new_ctx.css_state = &css; | |
3828 | cxx_eval_constant_expression (&new_ctx, body, false, | |
3829 | non_constant_p, overflow_p, jump_target); | |
3830 | if (switches (jump_target) && css == css_default_seen) | |
3831 | { | |
3832 | /* If the SWITCH_EXPR body has default: label, process it once again, | |
3833 | this time instructing label_matches to return true for default: | |
3834 | label on switches (jump_target). */ | |
3835 | css = css_default_processing; | |
3836 | cxx_eval_constant_expression (&new_ctx, body, false, | |
3837 | non_constant_p, overflow_p, jump_target); | |
3838 | } | |
00f21715 | 3839 | if (breaks (jump_target) || switches (jump_target)) |
3840 | *jump_target = NULL_TREE; | |
3841 | return NULL_TREE; | |
3842 | } | |
3843 | ||
85de9604 | 3844 | /* Find the object of TYPE under initialization in CTX. */ |
3845 | ||
3846 | static tree | |
3847 | lookup_placeholder (const constexpr_ctx *ctx, bool lval, tree type) | |
3848 | { | |
def8e41f | 3849 | if (!ctx) |
85de9604 | 3850 | return NULL_TREE; |
3851 | ||
3852 | /* We could use ctx->object unconditionally, but using ctx->ctor when we | |
3853 | can is a minor optimization. */ | |
def8e41f | 3854 | if (!lval && ctx->ctor && same_type_p (TREE_TYPE (ctx->ctor), type)) |
85de9604 | 3855 | return ctx->ctor; |
3856 | ||
def8e41f | 3857 | if (!ctx->object) |
3858 | return NULL_TREE; | |
3859 | ||
85de9604 | 3860 | /* Since an object cannot have a field of its own type, we can search outward |
3861 | from ctx->object to find the unique containing object of TYPE. */ | |
3862 | tree ob = ctx->object; | |
3863 | while (ob) | |
3864 | { | |
3865 | if (same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (ob), type)) | |
3866 | break; | |
3867 | if (handled_component_p (ob)) | |
3868 | ob = TREE_OPERAND (ob, 0); | |
3869 | else | |
3870 | ob = NULL_TREE; | |
3871 | } | |
3872 | ||
3873 | return ob; | |
3874 | } | |
3875 | ||
09b42213 | 3876 | /* Attempt to reduce the expression T to a constant value. |
3877 | On failure, issue diagnostic and return error_mark_node. */ | |
3878 | /* FIXME unify with c_fully_fold */ | |
9c96033c | 3879 | /* FIXME overflow_p is too global */ |
09b42213 | 3880 | |
3881 | static tree | |
cf72f34d | 3882 | cxx_eval_constant_expression (const constexpr_ctx *ctx, tree t, |
1227ba74 | 3883 | bool lval, |
00f21715 | 3884 | bool *non_constant_p, bool *overflow_p, |
3885 | tree *jump_target) | |
09b42213 | 3886 | { |
cf72f34d | 3887 | constexpr_ctx new_ctx; |
09b42213 | 3888 | tree r = t; |
3889 | ||
2a2770c6 | 3890 | if (jump_target && *jump_target) |
3891 | { | |
3892 | /* If we are jumping, ignore all statements/expressions except those | |
3893 | that could have LABEL_EXPR or CASE_LABEL_EXPR in their bodies. */ | |
3894 | switch (TREE_CODE (t)) | |
3895 | { | |
3896 | case BIND_EXPR: | |
3897 | case STATEMENT_LIST: | |
3898 | case LOOP_EXPR: | |
3899 | case COND_EXPR: | |
3900 | break; | |
3901 | case LABEL_EXPR: | |
3902 | case CASE_LABEL_EXPR: | |
3903 | if (label_matches (ctx, jump_target, t)) | |
3904 | /* Found it. */ | |
3905 | *jump_target = NULL_TREE; | |
3906 | return NULL_TREE; | |
3907 | default: | |
3908 | return NULL_TREE; | |
3909 | } | |
3910 | } | |
09b42213 | 3911 | if (t == error_mark_node) |
3912 | { | |
3913 | *non_constant_p = true; | |
3914 | return t; | |
3915 | } | |
3916 | if (CONSTANT_CLASS_P (t)) | |
3917 | { | |
c4fa85c9 | 3918 | if (TREE_OVERFLOW (t)) |
3919 | { | |
3920 | if (!ctx->quiet) | |
3921 | permerror (input_location, "overflow in constant expression"); | |
3922 | if (!flag_permissive || ctx->quiet) | |
3923 | *overflow_p = true; | |
3924 | } | |
cb768824 | 3925 | |
3926 | if (TREE_CODE (t) == INTEGER_CST | |
3927 | && TREE_CODE (TREE_TYPE (t)) == POINTER_TYPE | |
3928 | && !integer_zerop (t)) | |
3929 | { | |
3930 | if (!ctx->quiet) | |
3931 | error ("value %qE of type %qT is not a constant expression", | |
3932 | t, TREE_TYPE (t)); | |
3933 | *non_constant_p = true; | |
3934 | } | |
3935 | ||
09b42213 | 3936 | return t; |
3937 | } | |
09b42213 | 3938 | |
cb768824 | 3939 | tree_code tcode = TREE_CODE (t); |
3940 | switch (tcode) | |
09b42213 | 3941 | { |
9c96033c | 3942 | case RESULT_DECL: |
1227ba74 | 3943 | if (lval) |
9c96033c | 3944 | return t; |
3945 | /* We ask for an rvalue for the RESULT_DECL when indirecting | |
92a9c89e | 3946 | through an invisible reference, or in named return value |
3947 | optimization. */ | |
9c96033c | 3948 | return (*ctx->values->get (t)); |
3949 | ||
09b42213 | 3950 | case VAR_DECL: |
9c8aeb66 | 3951 | if (DECL_HAS_VALUE_EXPR_P (t)) |
33603066 | 3952 | return cxx_eval_constant_expression (ctx, DECL_VALUE_EXPR (t), |
3953 | lval, non_constant_p, overflow_p); | |
e3533433 | 3954 | /* fall through */ |
8b2b2f24 | 3955 | case CONST_DECL: |
3956 | /* We used to not check lval for CONST_DECL, but darwin.c uses | |
3957 | CONST_DECL for aggregate constants. */ | |
1227ba74 | 3958 | if (lval) |
09b42213 | 3959 | return t; |
594cc00c | 3960 | if (COMPLETE_TYPE_P (TREE_TYPE (t)) |
3961 | && is_really_empty_class (TREE_TYPE (t))) | |
c7282bf2 | 3962 | { |
3963 | /* If the class is empty, we aren't actually loading anything. */ | |
3964 | r = build_constructor (TREE_TYPE (t), NULL); | |
3965 | TREE_CONSTANT (r) = true; | |
3966 | } | |
3967 | else if (ctx->strict) | |
2055d27a | 3968 | r = decl_really_constant_value (t); |
3969 | else | |
3970 | r = decl_constant_value (t); | |
09b42213 | 3971 | if (TREE_CODE (r) == TARGET_EXPR |
3972 | && TREE_CODE (TARGET_EXPR_INITIAL (r)) == CONSTRUCTOR) | |
3973 | r = TARGET_EXPR_INITIAL (r); | |
f4ae4202 | 3974 | if (VAR_P (r)) |
cf72f34d | 3975 | if (tree *p = ctx->values->get (r)) |
a143e277 | 3976 | if (*p != NULL_TREE) |
3977 | r = *p; | |
09b42213 | 3978 | if (DECL_P (r)) |
3979 | { | |
f83e6885 | 3980 | if (!ctx->quiet) |
09b42213 | 3981 | non_const_var_error (r); |
3982 | *non_constant_p = true; | |
3983 | } | |
3984 | break; | |
3985 | ||
3986 | case FUNCTION_DECL: | |
3987 | case TEMPLATE_DECL: | |
3988 | case LABEL_DECL: | |
00f21715 | 3989 | case LABEL_EXPR: |
3990 | case CASE_LABEL_EXPR: | |
2a2770c6 | 3991 | case PREDICT_EXPR: |
09b42213 | 3992 | return t; |
3993 | ||
3994 | case PARM_DECL: | |
88a59139 | 3995 | if (lval && TREE_CODE (TREE_TYPE (t)) != REFERENCE_TYPE) |
9c96033c | 3996 | /* glvalue use. */; |
3997 | else if (tree *p = ctx->values->get (r)) | |
3998 | r = *p; | |
1227ba74 | 3999 | else if (lval) |
09b42213 | 4000 | /* Defer in case this is only used for its type. */; |
1eb418cc | 4001 | else if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE) |
4002 | /* Defer, there's no lvalue->rvalue conversion. */; | |
53d2f3de | 4003 | else if (COMPLETE_TYPE_P (TREE_TYPE (t)) |
4004 | && is_really_empty_class (TREE_TYPE (t))) | |
a6613de7 | 4005 | { |
4006 | /* If the class is empty, we aren't actually loading anything. */ | |
4007 | r = build_constructor (TREE_TYPE (t), NULL); | |
4008 | TREE_CONSTANT (r) = true; | |
4009 | } | |
09b42213 | 4010 | else |
4011 | { | |
f83e6885 | 4012 | if (!ctx->quiet) |
09b42213 | 4013 | error ("%qE is not a constant expression", t); |
4014 | *non_constant_p = true; | |
4015 | } | |
4016 | break; | |
4017 | ||
4018 | case CALL_EXPR: | |
4019 | case AGGR_INIT_EXPR: | |
1227ba74 | 4020 | r = cxx_eval_call_expression (ctx, t, lval, |
09b42213 | 4021 | non_constant_p, overflow_p); |
4022 | break; | |
4023 | ||
9c96033c | 4024 | case DECL_EXPR: |
4025 | { | |
4026 | r = DECL_EXPR_DECL (t); | |
4027 | if (AGGREGATE_TYPE_P (TREE_TYPE (r)) | |
4028 | || VECTOR_TYPE_P (TREE_TYPE (r))) | |
4029 | { | |
4030 | new_ctx = *ctx; | |
4031 | new_ctx.object = r; | |
4032 | new_ctx.ctor = build_constructor (TREE_TYPE (r), NULL); | |
4033 | CONSTRUCTOR_NO_IMPLICIT_ZERO (new_ctx.ctor) = true; | |
4034 | new_ctx.values->put (r, new_ctx.ctor); | |
4035 | ctx = &new_ctx; | |
4036 | } | |
4037 | ||
4038 | if (tree init = DECL_INITIAL (r)) | |
4039 | { | |
4040 | init = cxx_eval_constant_expression (ctx, init, | |
f83e6885 | 4041 | false, |
b2a43197 | 4042 | non_constant_p, overflow_p); |
5898f0d7 | 4043 | /* Don't share a CONSTRUCTOR that might be changed. */ |
e283bb4f | 4044 | init = unshare_constructor (init); |
9c96033c | 4045 | ctx->values->put (r, init); |
4046 | } | |
4047 | else if (ctx == &new_ctx) | |
4048 | /* We gave it a CONSTRUCTOR above. */; | |
4049 | else | |
4050 | ctx->values->put (r, NULL_TREE); | |
4051 | } | |
4052 | break; | |
4053 | ||
09b42213 | 4054 | case TARGET_EXPR: |
4055 | if (!literal_type_p (TREE_TYPE (t))) | |
4056 | { | |
f83e6885 | 4057 | if (!ctx->quiet) |
09b42213 | 4058 | { |
4059 | error ("temporary of non-literal type %qT in a " | |
4060 | "constant expression", TREE_TYPE (t)); | |
4061 | explain_non_literal_class (TREE_TYPE (t)); | |
4062 | } | |
4063 | *non_constant_p = true; | |
4064 | break; | |
4065 | } | |
cf72f34d | 4066 | if ((AGGREGATE_TYPE_P (TREE_TYPE (t)) || VECTOR_TYPE_P (TREE_TYPE (t)))) |
4067 | { | |
4068 | /* We're being expanded without an explicit target, so start | |
4069 | initializing a new object; expansion with an explicit target | |
4070 | strips the TARGET_EXPR before we get here. */ | |
4071 | new_ctx = *ctx; | |
4072 | new_ctx.ctor = build_constructor (TREE_TYPE (t), NULL); | |
4073 | CONSTRUCTOR_NO_IMPLICIT_ZERO (new_ctx.ctor) = true; | |
4074 | new_ctx.object = TARGET_EXPR_SLOT (t); | |
4075 | ctx->values->put (new_ctx.object, new_ctx.ctor); | |
4076 | ctx = &new_ctx; | |
4077 | } | |
1227ba74 | 4078 | /* Pass false for 'lval' because this indicates |
09b42213 | 4079 | initialization of a temporary. */ |
cf72f34d | 4080 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), |
f83e6885 | 4081 | false, |
b2a43197 | 4082 | non_constant_p, overflow_p); |
09b42213 | 4083 | if (!*non_constant_p) |
4084 | /* Adjust the type of the result to the type of the temporary. */ | |
4085 | r = adjust_temp_type (TREE_TYPE (t), r); | |
1227ba74 | 4086 | if (lval) |
1eb418cc | 4087 | { |
4088 | tree slot = TARGET_EXPR_SLOT (t); | |
e283bb4f | 4089 | r = unshare_constructor (r); |
1eb418cc | 4090 | ctx->values->put (slot, r); |
4091 | return slot; | |
4092 | } | |
09b42213 | 4093 | break; |
4094 | ||
9c96033c | 4095 | case INIT_EXPR: |
9c96033c | 4096 | case MODIFY_EXPR: |
2a2770c6 | 4097 | gcc_assert (jump_target == NULL || *jump_target == NULL_TREE); |
1227ba74 | 4098 | r = cxx_eval_store_expression (ctx, t, lval, |
9c96033c | 4099 | non_constant_p, overflow_p); |
4100 | break; | |
4101 | ||
09b42213 | 4102 | case SCOPE_REF: |
cf72f34d | 4103 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), |
1227ba74 | 4104 | lval, |
b2a43197 | 4105 | non_constant_p, overflow_p); |
09b42213 | 4106 | break; |
4107 | ||
4108 | case RETURN_EXPR: | |
10fb495c | 4109 | if (TREE_OPERAND (t, 0) != NULL_TREE) |
4110 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), | |
4111 | lval, | |
4112 | non_constant_p, overflow_p); | |
00f21715 | 4113 | *jump_target = t; |
4114 | break; | |
4115 | ||
e0e672a0 | 4116 | case SAVE_EXPR: |
4117 | /* Avoid evaluating a SAVE_EXPR more than once. */ | |
4118 | if (tree *p = ctx->values->get (t)) | |
4119 | r = *p; | |
4120 | else | |
4121 | { | |
c8f6aeb1 | 4122 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), false, |
e0e672a0 | 4123 | non_constant_p, overflow_p); |
4124 | ctx->values->put (t, r); | |
2631cb67 | 4125 | if (ctx->save_exprs) |
4126 | ctx->save_exprs->add (t); | |
e0e672a0 | 4127 | } |
4128 | break; | |
4129 | ||
09b42213 | 4130 | case NON_LVALUE_EXPR: |
4131 | case TRY_CATCH_EXPR: | |
7f67d68c | 4132 | case TRY_BLOCK: |
09b42213 | 4133 | case CLEANUP_POINT_EXPR: |
4134 | case MUST_NOT_THROW_EXPR: | |
9c96033c | 4135 | case EXPR_STMT: |
4136 | case EH_SPEC_BLOCK: | |
cf72f34d | 4137 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), |
1227ba74 | 4138 | lval, |
00f21715 | 4139 | non_constant_p, overflow_p, |
4140 | jump_target); | |
09b42213 | 4141 | break; |
4142 | ||
7f67d68c | 4143 | case TRY_FINALLY_EXPR: |
4144 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval, | |
4145 | non_constant_p, overflow_p, | |
4146 | jump_target); | |
4147 | if (!*non_constant_p) | |
4148 | /* Also evaluate the cleanup. */ | |
4149 | cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), true, | |
4150 | non_constant_p, overflow_p, | |
4151 | jump_target); | |
4152 | break; | |
4153 | ||
09b42213 | 4154 | /* These differ from cxx_eval_unary_expression in that this doesn't |
4155 | check for a constant operand or result; an address can be | |
4156 | constant without its operand being, and vice versa. */ | |
d2c63826 | 4157 | case MEM_REF: |
09b42213 | 4158 | case INDIRECT_REF: |
1227ba74 | 4159 | r = cxx_eval_indirect_ref (ctx, t, lval, |
09b42213 | 4160 | non_constant_p, overflow_p); |
4161 | break; | |
4162 | ||
4163 | case ADDR_EXPR: | |
4164 | { | |
4165 | tree oldop = TREE_OPERAND (t, 0); | |
cf72f34d | 4166 | tree op = cxx_eval_constant_expression (ctx, oldop, |
1227ba74 | 4167 | /*lval*/true, |
b2a43197 | 4168 | non_constant_p, overflow_p); |
09b42213 | 4169 | /* Don't VERIFY_CONSTANT here. */ |
4170 | if (*non_constant_p) | |
4171 | return t; | |
1eb418cc | 4172 | gcc_checking_assert (TREE_CODE (op) != CONSTRUCTOR); |
09b42213 | 4173 | /* This function does more aggressive folding than fold itself. */ |
4174 | r = build_fold_addr_expr_with_type (op, TREE_TYPE (t)); | |
4175 | if (TREE_CODE (r) == ADDR_EXPR && TREE_OPERAND (r, 0) == oldop) | |
4176 | return t; | |
4177 | break; | |
4178 | } | |
4179 | ||
4180 | case REALPART_EXPR: | |
4181 | case IMAGPART_EXPR: | |
6fe424c2 | 4182 | if (lval) |
4183 | { | |
4184 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval, | |
4185 | non_constant_p, overflow_p); | |
4186 | if (r == error_mark_node) | |
4187 | ; | |
4188 | else if (r == TREE_OPERAND (t, 0)) | |
4189 | r = t; | |
4190 | else | |
4191 | r = fold_build1 (TREE_CODE (t), TREE_TYPE (t), r); | |
4192 | break; | |
4193 | } | |
4194 | /* FALLTHRU */ | |
09b42213 | 4195 | case CONJ_EXPR: |
4196 | case FIX_TRUNC_EXPR: | |
4197 | case FLOAT_EXPR: | |
4198 | case NEGATE_EXPR: | |
4199 | case ABS_EXPR: | |
4200 | case BIT_NOT_EXPR: | |
4201 | case TRUTH_NOT_EXPR: | |
4202 | case FIXED_CONVERT_EXPR: | |
1227ba74 | 4203 | r = cxx_eval_unary_expression (ctx, t, lval, |
09b42213 | 4204 | non_constant_p, overflow_p); |
4205 | break; | |
4206 | ||
4207 | case SIZEOF_EXPR: | |
d2c63826 | 4208 | r = fold_sizeof_expr (t); |
09b42213 | 4209 | VERIFY_CONSTANT (r); |
4210 | break; | |
4211 | ||
4212 | case COMPOUND_EXPR: | |
4213 | { | |
4214 | /* check_return_expr sometimes wraps a TARGET_EXPR in a | |
4215 | COMPOUND_EXPR; don't get confused. Also handle EMPTY_CLASS_EXPR | |
4216 | introduced by build_call_a. */ | |
4217 | tree op0 = TREE_OPERAND (t, 0); | |
4218 | tree op1 = TREE_OPERAND (t, 1); | |
4219 | STRIP_NOPS (op1); | |
4220 | if ((TREE_CODE (op0) == TARGET_EXPR && op1 == TARGET_EXPR_SLOT (op0)) | |
4221 | || TREE_CODE (op1) == EMPTY_CLASS_EXPR) | |
f83e6885 | 4222 | r = cxx_eval_constant_expression (ctx, op0, |
1227ba74 | 4223 | lval, non_constant_p, overflow_p, |
00f21715 | 4224 | jump_target); |
09b42213 | 4225 | else |
4226 | { | |
4227 | /* Check that the LHS is constant and then discard it. */ | |
f83e6885 | 4228 | cxx_eval_constant_expression (ctx, op0, |
c8f6aeb1 | 4229 | true, non_constant_p, overflow_p, |
00f21715 | 4230 | jump_target); |
cf03ba19 | 4231 | if (*non_constant_p) |
4232 | return t; | |
09b42213 | 4233 | op1 = TREE_OPERAND (t, 1); |
f83e6885 | 4234 | r = cxx_eval_constant_expression (ctx, op1, |
1227ba74 | 4235 | lval, non_constant_p, overflow_p, |
00f21715 | 4236 | jump_target); |
09b42213 | 4237 | } |
4238 | } | |
4239 | break; | |
4240 | ||
4241 | case POINTER_PLUS_EXPR: | |
4242 | case PLUS_EXPR: | |
4243 | case MINUS_EXPR: | |
4244 | case MULT_EXPR: | |
4245 | case TRUNC_DIV_EXPR: | |
4246 | case CEIL_DIV_EXPR: | |
4247 | case FLOOR_DIV_EXPR: | |
4248 | case ROUND_DIV_EXPR: | |
4249 | case TRUNC_MOD_EXPR: | |
4250 | case CEIL_MOD_EXPR: | |
4251 | case ROUND_MOD_EXPR: | |
4252 | case RDIV_EXPR: | |
4253 | case EXACT_DIV_EXPR: | |
4254 | case MIN_EXPR: | |
4255 | case MAX_EXPR: | |
4256 | case LSHIFT_EXPR: | |
4257 | case RSHIFT_EXPR: | |
4258 | case LROTATE_EXPR: | |
4259 | case RROTATE_EXPR: | |
4260 | case BIT_IOR_EXPR: | |
4261 | case BIT_XOR_EXPR: | |
4262 | case BIT_AND_EXPR: | |
4263 | case TRUTH_XOR_EXPR: | |
4264 | case LT_EXPR: | |
4265 | case LE_EXPR: | |
4266 | case GT_EXPR: | |
4267 | case GE_EXPR: | |
4268 | case EQ_EXPR: | |
4269 | case NE_EXPR: | |
4270 | case UNORDERED_EXPR: | |
4271 | case ORDERED_EXPR: | |
4272 | case UNLT_EXPR: | |
4273 | case UNLE_EXPR: | |
4274 | case UNGT_EXPR: | |
4275 | case UNGE_EXPR: | |
4276 | case UNEQ_EXPR: | |
4277 | case LTGT_EXPR: | |
4278 | case RANGE_EXPR: | |
4279 | case COMPLEX_EXPR: | |
1227ba74 | 4280 | r = cxx_eval_binary_expression (ctx, t, lval, |
09b42213 | 4281 | non_constant_p, overflow_p); |
4282 | break; | |
4283 | ||
4284 | /* fold can introduce non-IF versions of these; still treat them as | |
4285 | short-circuiting. */ | |
4286 | case TRUTH_AND_EXPR: | |
4287 | case TRUTH_ANDIF_EXPR: | |
cf72f34d | 4288 | r = cxx_eval_logical_expression (ctx, t, boolean_false_node, |
09b42213 | 4289 | boolean_true_node, |
1227ba74 | 4290 | lval, |
09b42213 | 4291 | non_constant_p, overflow_p); |
4292 | break; | |
4293 | ||
4294 | case TRUTH_OR_EXPR: | |
4295 | case TRUTH_ORIF_EXPR: | |
cf72f34d | 4296 | r = cxx_eval_logical_expression (ctx, t, boolean_true_node, |
09b42213 | 4297 | boolean_false_node, |
1227ba74 | 4298 | lval, |
09b42213 | 4299 | non_constant_p, overflow_p); |
4300 | break; | |
4301 | ||
4302 | case ARRAY_REF: | |
1227ba74 | 4303 | r = cxx_eval_array_reference (ctx, t, lval, |
09b42213 | 4304 | non_constant_p, overflow_p); |
4305 | break; | |
4306 | ||
4307 | case COMPONENT_REF: | |
4308 | if (is_overloaded_fn (t)) | |
4309 | { | |
4310 | /* We can only get here in checking mode via | |
4311 | build_non_dependent_expr, because any expression that | |
4312 | calls or takes the address of the function will have | |
4313 | pulled a FUNCTION_DECL out of the COMPONENT_REF. */ | |
f83e6885 | 4314 | gcc_checking_assert (ctx->quiet || errorcount); |
09b42213 | 4315 | *non_constant_p = true; |
4316 | return t; | |
4317 | } | |
1227ba74 | 4318 | r = cxx_eval_component_reference (ctx, t, lval, |
09b42213 | 4319 | non_constant_p, overflow_p); |
4320 | break; | |
4321 | ||
4322 | case BIT_FIELD_REF: | |
1227ba74 | 4323 | r = cxx_eval_bit_field_ref (ctx, t, lval, |
09b42213 | 4324 | non_constant_p, overflow_p); |
4325 | break; | |
4326 | ||
4327 | case COND_EXPR: | |
2a2770c6 | 4328 | if (jump_target && *jump_target) |
4329 | { | |
4330 | /* When jumping to a label, the label might be either in the | |
4331 | then or else blocks, so process then block first in skipping | |
4332 | mode first, and if we are still in the skipping mode at its end, | |
4333 | process the else block too. */ | |
4334 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), | |
4335 | lval, non_constant_p, overflow_p, | |
4336 | jump_target); | |
4337 | if (*jump_target) | |
4338 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 2), | |
4339 | lval, non_constant_p, overflow_p, | |
4340 | jump_target); | |
4341 | break; | |
4342 | } | |
4343 | /* FALLTHRU */ | |
09b42213 | 4344 | case VEC_COND_EXPR: |
1227ba74 | 4345 | r = cxx_eval_conditional_expression (ctx, t, lval, |
00f21715 | 4346 | non_constant_p, overflow_p, |
4347 | jump_target); | |
09b42213 | 4348 | break; |
4349 | ||
4350 | case CONSTRUCTOR: | |
1a3631bc | 4351 | if (TREE_CONSTANT (t)) |
58b0f9ce | 4352 | { |
4353 | /* Don't re-process a constant CONSTRUCTOR, but do fold it to | |
4354 | VECTOR_CST if applicable. */ | |
4355 | /* FIXME after GCC 6 branches, make the verify unconditional. */ | |
4356 | if (CHECKING_P) | |
4357 | verify_constructor_flags (t); | |
4358 | else | |
4359 | recompute_constructor_flags (t); | |
4360 | if (TREE_CONSTANT (t)) | |
4361 | return fold (t); | |
4362 | } | |
1227ba74 | 4363 | r = cxx_eval_bare_aggregate (ctx, t, lval, |
09b42213 | 4364 | non_constant_p, overflow_p); |
4365 | break; | |
4366 | ||
4367 | case VEC_INIT_EXPR: | |
4368 | /* We can get this in a defaulted constructor for a class with a | |
4369 | non-static data member of array type. Either the initializer will | |
4370 | be NULL, meaning default-initialization, or it will be an lvalue | |
4371 | or xvalue of the same type, meaning direct-initialization from the | |
4372 | corresponding member. */ | |
1227ba74 | 4373 | r = cxx_eval_vec_init (ctx, t, lval, |
09b42213 | 4374 | non_constant_p, overflow_p); |
4375 | break; | |
4376 | ||
4377 | case FMA_EXPR: | |
4378 | case VEC_PERM_EXPR: | |
1227ba74 | 4379 | r = cxx_eval_trinary_expression (ctx, t, lval, |
09b42213 | 4380 | non_constant_p, overflow_p); |
4381 | break; | |
4382 | ||
4383 | case CONVERT_EXPR: | |
4384 | case VIEW_CONVERT_EXPR: | |
4385 | case NOP_EXPR: | |
d2c63826 | 4386 | case UNARY_PLUS_EXPR: |
09b42213 | 4387 | { |
4388 | tree oldop = TREE_OPERAND (t, 0); | |
d2c63826 | 4389 | |
cf72f34d | 4390 | tree op = cxx_eval_constant_expression (ctx, oldop, |
1227ba74 | 4391 | lval, |
b2a43197 | 4392 | non_constant_p, overflow_p); |
09b42213 | 4393 | if (*non_constant_p) |
4394 | return t; | |
f16ed232 | 4395 | tree type = TREE_TYPE (t); |
4396 | if (TREE_CODE (op) == PTRMEM_CST | |
4397 | && !TYPE_PTRMEM_P (type)) | |
4398 | op = cplus_expand_constant (op); | |
6a9b35ef | 4399 | if (TREE_CODE (op) == PTRMEM_CST && tcode == NOP_EXPR) |
4400 | { | |
4401 | if (same_type_ignoring_top_level_qualifiers_p (type, | |
0a8a2108 | 4402 | TREE_TYPE (op)) |
4403 | || can_convert_qual (type, op)) | |
19d56e62 | 4404 | return cp_fold_convert (type, op); |
6a9b35ef | 4405 | else |
4406 | { | |
4407 | if (!ctx->quiet) | |
4408 | error_at (EXPR_LOC_OR_LOC (t, input_location), | |
ea034e2c | 4409 | "a reinterpret_cast is not a constant expression"); |
6a9b35ef | 4410 | *non_constant_p = true; |
4411 | return t; | |
4412 | } | |
4413 | } | |
cb768824 | 4414 | |
4415 | if (POINTER_TYPE_P (type) && TREE_CODE (op) == INTEGER_CST) | |
09b42213 | 4416 | { |
cb768824 | 4417 | if (integer_zerop (op)) |
4418 | { | |
4419 | if (TREE_CODE (type) == REFERENCE_TYPE) | |
4420 | { | |
4421 | if (!ctx->quiet) | |
4422 | error_at (EXPR_LOC_OR_LOC (t, input_location), | |
4423 | "dereferencing a null pointer"); | |
4424 | *non_constant_p = true; | |
4425 | return t; | |
4426 | } | |
4427 | else if (TREE_CODE (TREE_TYPE (op)) == POINTER_TYPE) | |
4428 | { | |
4429 | tree from = TREE_TYPE (op); | |
4430 | ||
4431 | if (!can_convert (type, from, tf_none)) | |
4432 | { | |
4433 | if (!ctx->quiet) | |
4434 | error_at (EXPR_LOC_OR_LOC (t, input_location), | |
4435 | "conversion of %qT null pointer to %qT " | |
4436 | "is not a constant expression", | |
4437 | from, type); | |
4438 | *non_constant_p = true; | |
4439 | return t; | |
4440 | } | |
4441 | } | |
4442 | } | |
4443 | else | |
4444 | { | |
4445 | /* This detects for example: | |
4446 | reinterpret_cast<void*>(sizeof 0) | |
4447 | */ | |
4448 | if (!ctx->quiet) | |
4449 | error_at (EXPR_LOC_OR_LOC (t, input_location), | |
4450 | "%<reinterpret_cast<%T>(%E)%> is not " | |
ea034e2c | 4451 | "a constant expression", |
cb768824 | 4452 | type, op); |
4453 | *non_constant_p = true; | |
4454 | return t; | |
4455 | } | |
09b42213 | 4456 | } |
d2c63826 | 4457 | if (op == oldop && tcode != UNARY_PLUS_EXPR) |
09b42213 | 4458 | /* We didn't fold at the top so we could check for ptr-int |
4459 | conversion. */ | |
4460 | return fold (t); | |
d2c63826 | 4461 | if (tcode == UNARY_PLUS_EXPR) |
4462 | r = fold_convert (TREE_TYPE (t), op); | |
4463 | else | |
4464 | r = fold_build1 (tcode, type, op); | |
09b42213 | 4465 | /* Conversion of an out-of-range value has implementation-defined |
4466 | behavior; the language considers it different from arithmetic | |
4467 | overflow, which is undefined. */ | |
4468 | if (TREE_OVERFLOW_P (r) && !TREE_OVERFLOW_P (op)) | |
4469 | TREE_OVERFLOW (r) = false; | |
4470 | } | |
4471 | break; | |
4472 | ||
4473 | case EMPTY_CLASS_EXPR: | |
4474 | /* This is good enough for a function argument that might not get | |
4475 | used, and they can't do anything with it, so just return it. */ | |
4476 | return t; | |
4477 | ||
9c96033c | 4478 | case STATEMENT_LIST: |
00f21715 | 4479 | new_ctx = *ctx; |
4480 | new_ctx.ctor = new_ctx.object = NULL_TREE; | |
f83e6885 | 4481 | return cxx_eval_statement_list (&new_ctx, t, |
00f21715 | 4482 | non_constant_p, overflow_p, jump_target); |
9c96033c | 4483 | |
4484 | case BIND_EXPR: | |
4485 | return cxx_eval_constant_expression (ctx, BIND_EXPR_BODY (t), | |
1227ba74 | 4486 | lval, |
00f21715 | 4487 | non_constant_p, overflow_p, |
4488 | jump_target); | |
9c96033c | 4489 | |
09b42213 | 4490 | case PREINCREMENT_EXPR: |
4491 | case POSTINCREMENT_EXPR: | |
4492 | case PREDECREMENT_EXPR: | |
4493 | case POSTDECREMENT_EXPR: | |
f83e6885 | 4494 | return cxx_eval_increment_expression (ctx, t, |
1227ba74 | 4495 | lval, non_constant_p, overflow_p); |
9c96033c | 4496 | |
4497 | case LAMBDA_EXPR: | |
09b42213 | 4498 | case NEW_EXPR: |
4499 | case VEC_NEW_EXPR: | |
4500 | case DELETE_EXPR: | |
4501 | case VEC_DELETE_EXPR: | |
4502 | case THROW_EXPR: | |
09b42213 | 4503 | case MODOP_EXPR: |
4504 | /* GCC internal stuff. */ | |
4505 | case VA_ARG_EXPR: | |
4506 | case OBJ_TYPE_REF: | |
4507 | case WITH_CLEANUP_EXPR: | |
09b42213 | 4508 | case NON_DEPENDENT_EXPR: |
4509 | case BASELINK: | |
09b42213 | 4510 | case OFFSET_REF: |
f83e6885 | 4511 | if (!ctx->quiet) |
09b42213 | 4512 | error_at (EXPR_LOC_OR_LOC (t, input_location), |
ea034e2c | 4513 | "expression %qE is not a constant expression", t); |
09b42213 | 4514 | *non_constant_p = true; |
4515 | break; | |
4516 | ||
cf72f34d | 4517 | case PLACEHOLDER_EXPR: |
85de9604 | 4518 | /* Use of the value or address of the current object. */ |
4519 | if (tree ctor = lookup_placeholder (ctx, lval, TREE_TYPE (t))) | |
4520 | return cxx_eval_constant_expression (ctx, ctor, lval, | |
4521 | non_constant_p, overflow_p); | |
4522 | /* A placeholder without a referent. We can get here when | |
4523 | checking whether NSDMIs are noexcept, or in massage_init_elt; | |
4524 | just say it's non-constant for now. */ | |
4525 | gcc_assert (ctx->quiet); | |
4526 | *non_constant_p = true; | |
cf72f34d | 4527 | break; |
4528 | ||
cf03ba19 | 4529 | case EXIT_EXPR: |
4530 | { | |
4531 | tree cond = TREE_OPERAND (t, 0); | |
4532 | cond = cxx_eval_constant_expression (ctx, cond, /*lval*/false, | |
4533 | non_constant_p, overflow_p); | |
4534 | VERIFY_CONSTANT (cond); | |
4535 | if (integer_nonzerop (cond)) | |
4536 | *jump_target = t; | |
4537 | } | |
4538 | break; | |
4539 | ||
9c96033c | 4540 | case GOTO_EXPR: |
00f21715 | 4541 | *jump_target = TREE_OPERAND (t, 0); |
4542 | gcc_assert (breaks (jump_target) || continues (jump_target)); | |
4543 | break; | |
4544 | ||
9c96033c | 4545 | case LOOP_EXPR: |
f83e6885 | 4546 | cxx_eval_loop_expr (ctx, t, |
00f21715 | 4547 | non_constant_p, overflow_p, jump_target); |
4548 | break; | |
4549 | ||
9c96033c | 4550 | case SWITCH_EXPR: |
f83e6885 | 4551 | cxx_eval_switch_expr (ctx, t, |
00f21715 | 4552 | non_constant_p, overflow_p, jump_target); |
9c96033c | 4553 | break; |
4554 | ||
56c12fd4 | 4555 | case REQUIRES_EXPR: |
4556 | /* It's possible to get a requires-expression in a constant | |
4557 | expression. For example: | |
4558 | ||
4559 | template<typename T> concept bool C() { | |
4560 | return requires (T t) { t; }; | |
4561 | } | |
4562 | ||
4563 | template<typename T> requires !C<T>() void f(T); | |
4564 | ||
4565 | Normalization leaves f with the associated constraint | |
4566 | '!requires (T t) { ... }' which is not transformed into | |
4567 | a constraint. */ | |
4568 | if (!processing_template_decl) | |
4569 | return evaluate_constraint_expression (t, NULL_TREE); | |
4570 | else | |
4571 | *non_constant_p = true; | |
4572 | return t; | |
4573 | ||
24c6ee98 | 4574 | case ANNOTATE_EXPR: |
4575 | gcc_assert (tree_to_uhwi (TREE_OPERAND (t, 1)) == annot_expr_ivdep_kind); | |
4576 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), | |
4577 | lval, | |
4578 | non_constant_p, overflow_p, | |
4579 | jump_target); | |
4580 | break; | |
4581 | ||
09b42213 | 4582 | default: |
b9a3af23 | 4583 | if (STATEMENT_CODE_P (TREE_CODE (t))) |
4584 | { | |
4585 | /* This function doesn't know how to deal with pre-genericize | |
4586 | statements; this can only happen with statement-expressions, | |
4587 | so for now just fail. */ | |
4588 | if (!ctx->quiet) | |
4589 | error_at (EXPR_LOCATION (t), | |
ea034e2c | 4590 | "statement is not a constant expression"); |
b9a3af23 | 4591 | } |
4592 | else | |
4593 | internal_error ("unexpected expression %qE of kind %s", t, | |
4594 | get_tree_code_name (TREE_CODE (t))); | |
09b42213 | 4595 | *non_constant_p = true; |
4596 | break; | |
4597 | } | |
4598 | ||
4599 | if (r == error_mark_node) | |
4600 | *non_constant_p = true; | |
4601 | ||
4602 | if (*non_constant_p) | |
4603 | return t; | |
4604 | else | |
4605 | return r; | |
4606 | } | |
4607 | ||
4608 | static tree | |
cf72f34d | 4609 | cxx_eval_outermost_constant_expr (tree t, bool allow_non_constant, |
2055d27a | 4610 | bool strict = true, tree object = NULL_TREE) |
09b42213 | 4611 | { |
c300fe28 | 4612 | auto_timevar time (TV_CONSTEXPR); |
4613 | ||
09b42213 | 4614 | bool non_constant_p = false; |
4615 | bool overflow_p = false; | |
cf72f34d | 4616 | hash_map<tree,tree> map; |
2631cb67 | 4617 | |
2a2770c6 | 4618 | constexpr_ctx ctx = { NULL, &map, NULL, NULL, NULL, NULL, |
2631cb67 | 4619 | allow_non_constant, strict }; |
4620 | ||
cf72f34d | 4621 | tree type = initialized_type (t); |
cf72f34d | 4622 | tree r = t; |
4623 | if (AGGREGATE_TYPE_P (type) || VECTOR_TYPE_P (type)) | |
4624 | { | |
4625 | /* In C++14 an NSDMI can participate in aggregate initialization, | |
4626 | and can refer to the address of the object being initialized, so | |
4627 | we need to pass in the relevant VAR_DECL if we want to do the | |
4628 | evaluation in a single pass. The evaluation will dynamically | |
4629 | update ctx.values for the VAR_DECL. We use the same strategy | |
4630 | for C++11 constexpr constructors that refer to the object being | |
4631 | initialized. */ | |
4632 | ctx.ctor = build_constructor (type, NULL); | |
4633 | CONSTRUCTOR_NO_IMPLICIT_ZERO (ctx.ctor) = true; | |
9c96033c | 4634 | if (!object) |
4635 | { | |
4636 | if (TREE_CODE (t) == TARGET_EXPR) | |
4637 | object = TARGET_EXPR_SLOT (t); | |
4638 | else if (TREE_CODE (t) == AGGR_INIT_EXPR) | |
4639 | object = AGGR_INIT_EXPR_SLOT (t); | |
4640 | } | |
cf72f34d | 4641 | ctx.object = object; |
4642 | if (object) | |
4643 | gcc_assert (same_type_ignoring_top_level_qualifiers_p | |
4644 | (type, TREE_TYPE (object))); | |
4645 | if (object && DECL_P (object)) | |
4646 | map.put (object, ctx.ctor); | |
4647 | if (TREE_CODE (r) == TARGET_EXPR) | |
4648 | /* Avoid creating another CONSTRUCTOR when we expand the | |
4649 | TARGET_EXPR. */ | |
4650 | r = TARGET_EXPR_INITIAL (r); | |
4651 | } | |
4652 | ||
f83e6885 | 4653 | r = cxx_eval_constant_expression (&ctx, r, |
b2a43197 | 4654 | false, &non_constant_p, &overflow_p); |
09b42213 | 4655 | |
4656 | verify_constant (r, allow_non_constant, &non_constant_p, &overflow_p); | |
4657 | ||
bbcc9042 | 4658 | /* Mutable logic is a bit tricky: we want to allow initialization of |
4659 | constexpr variables with mutable members, but we can't copy those | |
4660 | members to another constexpr variable. */ | |
4661 | if (TREE_CODE (r) == CONSTRUCTOR | |
4662 | && CONSTRUCTOR_MUTABLE_POISON (r)) | |
09b42213 | 4663 | { |
09b42213 | 4664 | if (!allow_non_constant) |
bbcc9042 | 4665 | error ("%qE is not a constant expression because it refers to " |
4666 | "mutable subobjects of %qT", t, type); | |
09b42213 | 4667 | non_constant_p = true; |
4668 | } | |
4669 | ||
c6d97004 | 4670 | if (TREE_CODE (r) == CONSTRUCTOR |
4671 | && CONSTRUCTOR_NO_IMPLICIT_ZERO (r)) | |
4672 | { | |
4673 | if (!allow_non_constant) | |
4674 | error ("%qE is not a constant expression because it refers to " | |
4675 | "an incompletely initialized variable", t); | |
4676 | TREE_CONSTANT (r) = false; | |
4677 | non_constant_p = true; | |
4678 | } | |
4679 | ||
09b42213 | 4680 | /* Technically we should check this for all subexpressions, but that |
4681 | runs into problems with our internal representation of pointer | |
4682 | subtraction and the 5.19 rules are still in flux. */ | |
4683 | if (CONVERT_EXPR_CODE_P (TREE_CODE (r)) | |
4684 | && ARITHMETIC_TYPE_P (TREE_TYPE (r)) | |
4685 | && TREE_CODE (TREE_OPERAND (r, 0)) == ADDR_EXPR) | |
4686 | { | |
4687 | if (!allow_non_constant) | |
4688 | error ("conversion from pointer type %qT " | |
ea034e2c | 4689 | "to arithmetic type %qT in a constant expression", |
09b42213 | 4690 | TREE_TYPE (TREE_OPERAND (r, 0)), TREE_TYPE (r)); |
4691 | non_constant_p = true; | |
4692 | } | |
4693 | ||
4694 | if (!non_constant_p && overflow_p) | |
4695 | non_constant_p = true; | |
4696 | ||
c6c0523b | 4697 | /* Unshare the result unless it's a CONSTRUCTOR in which case it's already |
4698 | unshared. */ | |
4699 | bool should_unshare = true; | |
4700 | if (r == t || TREE_CODE (r) == CONSTRUCTOR) | |
4701 | should_unshare = false; | |
4702 | ||
09b42213 | 4703 | if (non_constant_p && !allow_non_constant) |
4704 | return error_mark_node; | |
4705 | else if (non_constant_p && TREE_CONSTANT (r)) | |
4706 | { | |
4707 | /* This isn't actually constant, so unset TREE_CONSTANT. */ | |
4708 | if (EXPR_P (r)) | |
4709 | r = copy_node (r); | |
4710 | else if (TREE_CODE (r) == CONSTRUCTOR) | |
4711 | r = build1 (VIEW_CONVERT_EXPR, TREE_TYPE (r), r); | |
4712 | else | |
4713 | r = build_nop (TREE_TYPE (r), r); | |
4714 | TREE_CONSTANT (r) = false; | |
4715 | } | |
4716 | else if (non_constant_p || r == t) | |
4717 | return t; | |
4718 | ||
c6c0523b | 4719 | if (should_unshare) |
4720 | r = unshare_expr (r); | |
4721 | ||
09b42213 | 4722 | if (TREE_CODE (r) == CONSTRUCTOR && CLASS_TYPE_P (TREE_TYPE (r))) |
4723 | { | |
4724 | if (TREE_CODE (t) == TARGET_EXPR | |
4725 | && TARGET_EXPR_INITIAL (t) == r) | |
4726 | return t; | |
4727 | else | |
4728 | { | |
4729 | r = get_target_expr (r); | |
4730 | TREE_CONSTANT (r) = true; | |
4731 | return r; | |
4732 | } | |
4733 | } | |
4734 | else | |
4735 | return r; | |
4736 | } | |
4737 | ||
4738 | /* Returns true if T is a valid subexpression of a constant expression, | |
4739 | even if it isn't itself a constant expression. */ | |
4740 | ||
4741 | bool | |
4742 | is_sub_constant_expr (tree t) | |
4743 | { | |
4744 | bool non_constant_p = false; | |
4745 | bool overflow_p = false; | |
cf72f34d | 4746 | hash_map <tree, tree> map; |
2631cb67 | 4747 | |
2a2770c6 | 4748 | constexpr_ctx ctx = { NULL, &map, NULL, NULL, NULL, NULL, true, true }; |
2631cb67 | 4749 | |
f83e6885 | 4750 | cxx_eval_constant_expression (&ctx, t, false, &non_constant_p, |
b2a43197 | 4751 | &overflow_p); |
09b42213 | 4752 | return !non_constant_p && !overflow_p; |
4753 | } | |
4754 | ||
4755 | /* If T represents a constant expression returns its reduced value. | |
4756 | Otherwise return error_mark_node. If T is dependent, then | |
4757 | return NULL. */ | |
4758 | ||
4759 | tree | |
cf72f34d | 4760 | cxx_constant_value (tree t, tree decl) |
09b42213 | 4761 | { |
2055d27a | 4762 | return cxx_eval_outermost_constant_expr (t, false, true, decl); |
09b42213 | 4763 | } |
4764 | ||
d2c63826 | 4765 | /* Helper routine for fold_simple function. Either return simplified |
4766 | expression T, otherwise NULL_TREE. | |
4767 | In contrast to cp_fully_fold, and to maybe_constant_value, we try to fold | |
4768 | even if we are within template-declaration. So be careful on call, as in | |
4769 | such case types can be undefined. */ | |
4770 | ||
4771 | static tree | |
4772 | fold_simple_1 (tree t) | |
4773 | { | |
4774 | tree op1; | |
4775 | enum tree_code code = TREE_CODE (t); | |
4776 | ||
4777 | switch (code) | |
4778 | { | |
4779 | case INTEGER_CST: | |
4780 | case REAL_CST: | |
4781 | case VECTOR_CST: | |
4782 | case FIXED_CST: | |
4783 | case COMPLEX_CST: | |
4784 | return t; | |
4785 | ||
4786 | case SIZEOF_EXPR: | |
4787 | return fold_sizeof_expr (t); | |
4788 | ||
4789 | case ABS_EXPR: | |
4790 | case CONJ_EXPR: | |
4791 | case REALPART_EXPR: | |
4792 | case IMAGPART_EXPR: | |
4793 | case NEGATE_EXPR: | |
4794 | case BIT_NOT_EXPR: | |
4795 | case TRUTH_NOT_EXPR: | |
4796 | case NOP_EXPR: | |
4797 | case VIEW_CONVERT_EXPR: | |
4798 | case CONVERT_EXPR: | |
4799 | case FLOAT_EXPR: | |
4800 | case FIX_TRUNC_EXPR: | |
4801 | case FIXED_CONVERT_EXPR: | |
4802 | case ADDR_SPACE_CONVERT_EXPR: | |
4803 | ||
4804 | op1 = TREE_OPERAND (t, 0); | |
4805 | ||
4806 | t = const_unop (code, TREE_TYPE (t), op1); | |
4807 | if (!t) | |
4808 | return NULL_TREE; | |
4809 | ||
4810 | if (CONVERT_EXPR_CODE_P (code) | |
4811 | && TREE_OVERFLOW_P (t) && !TREE_OVERFLOW_P (op1)) | |
4812 | TREE_OVERFLOW (t) = false; | |
4813 | return t; | |
4814 | ||
4815 | default: | |
4816 | return NULL_TREE; | |
4817 | } | |
4818 | } | |
4819 | ||
4820 | /* If T is a simple constant expression, returns its simplified value. | |
4821 | Otherwise returns T. In contrast to maybe_constant_value do we | |
4822 | simplify only few operations on constant-expressions, and we don't | |
4823 | try to simplify constexpressions. */ | |
4824 | ||
4825 | tree | |
4826 | fold_simple (tree t) | |
4827 | { | |
4828 | tree r = NULL_TREE; | |
4829 | if (processing_template_decl) | |
4830 | return t; | |
4831 | ||
4832 | r = fold_simple_1 (t); | |
4833 | if (!r) | |
4834 | r = t; | |
4835 | ||
4836 | return r; | |
4837 | } | |
4838 | ||
09b42213 | 4839 | /* If T is a constant expression, returns its reduced value. |
4840 | Otherwise, if T does not have TREE_CONSTANT set, returns T. | |
4841 | Otherwise, returns a version of T without TREE_CONSTANT. */ | |
4842 | ||
b601ad30 | 4843 | static GTY((deletable)) hash_map<tree, tree> *cv_cache; |
4844 | ||
4845 | tree | |
4846 | maybe_constant_value (tree t, tree decl) | |
09b42213 | 4847 | { |
4848 | tree r; | |
4849 | ||
29cf24ec | 4850 | if (!potential_nondependent_constant_expression (t)) |
09b42213 | 4851 | { |
4852 | if (TREE_OVERFLOW_P (t)) | |
4853 | { | |
4854 | t = build_nop (TREE_TYPE (t), t); | |
4855 | TREE_CONSTANT (t) = false; | |
4856 | } | |
4857 | return t; | |
4858 | } | |
b601ad30 | 4859 | else if (CONSTANT_CLASS_P (t)) |
4860 | /* No caching or evaluation needed. */ | |
4861 | return t; | |
4862 | ||
4863 | if (cv_cache == NULL) | |
4864 | cv_cache = hash_map<tree, tree>::create_ggc (101); | |
4865 | if (tree *cached = cv_cache->get (t)) | |
4866 | return *cached; | |
09b42213 | 4867 | |
2055d27a | 4868 | r = cxx_eval_outermost_constant_expr (t, true, true, decl); |
5e8689fb | 4869 | gcc_checking_assert (r == t |
4870 | || CONVERT_EXPR_P (t) | |
4871 | || TREE_CODE (t) == VIEW_CONVERT_EXPR | |
4872 | || (TREE_CONSTANT (t) && !TREE_CONSTANT (r)) | |
4873 | || !cp_tree_equal (r, t)); | |
b601ad30 | 4874 | cv_cache->put (t, r); |
09b42213 | 4875 | return r; |
4876 | } | |
4877 | ||
2a655a4c | 4878 | /* Dispose of the whole CV_CACHE. */ |
4879 | ||
4880 | static void | |
4881 | clear_cv_cache (void) | |
4882 | { | |
4883 | if (cv_cache != NULL) | |
4884 | cv_cache->empty (); | |
4885 | } | |
4886 | ||
f553d9f8 | 4887 | /* Dispose of the whole CV_CACHE and FOLD_CACHE. */ |
a0c919f7 | 4888 | |
4889 | void | |
f553d9f8 | 4890 | clear_cv_and_fold_caches (void) |
a0c919f7 | 4891 | { |
2a655a4c | 4892 | clear_cv_cache (); |
f553d9f8 | 4893 | clear_fold_cache (); |
a0c919f7 | 4894 | } |
4895 | ||
21131a05 | 4896 | /* Like maybe_constant_value but first fully instantiate the argument. |
4897 | ||
4898 | Note: this is equivalent to instantiate_non_dependent_expr_sfinae | |
4899 | (t, tf_none) followed by maybe_constant_value but is more efficient, | |
4900 | because calls instantiation_dependent_expression_p and | |
4901 | potential_constant_expression at most once. */ | |
4902 | ||
4903 | tree | |
4904 | fold_non_dependent_expr (tree t) | |
4905 | { | |
4906 | if (t == NULL_TREE) | |
4907 | return NULL_TREE; | |
4908 | ||
4909 | /* If we're in a template, but T isn't value dependent, simplify | |
4910 | it. We're supposed to treat: | |
4911 | ||
4912 | template <typename T> void f(T[1 + 1]); | |
4913 | template <typename T> void f(T[2]); | |
4914 | ||
4915 | as two declarations of the same function, for example. */ | |
4916 | if (processing_template_decl) | |
4917 | { | |
29cf24ec | 4918 | if (potential_nondependent_constant_expression (t)) |
21131a05 | 4919 | { |
c8a9f04c | 4920 | processing_template_decl_sentinel s; |
4921 | t = instantiate_non_dependent_expr_internal (t, tf_none); | |
21131a05 | 4922 | |
4923 | if (type_unknown_p (t) | |
4924 | || BRACE_ENCLOSED_INITIALIZER_P (t)) | |
4925 | { | |
4926 | if (TREE_OVERFLOW_P (t)) | |
4927 | { | |
4928 | t = build_nop (TREE_TYPE (t), t); | |
4929 | TREE_CONSTANT (t) = false; | |
4930 | } | |
4931 | return t; | |
4932 | } | |
4933 | ||
2055d27a | 4934 | tree r = cxx_eval_outermost_constant_expr (t, true, true, NULL_TREE); |
21131a05 | 4935 | /* cp_tree_equal looks through NOPs, so allow them. */ |
5e8689fb | 4936 | gcc_checking_assert (r == t |
4937 | || CONVERT_EXPR_P (t) | |
4938 | || TREE_CODE (t) == VIEW_CONVERT_EXPR | |
4939 | || (TREE_CONSTANT (t) && !TREE_CONSTANT (r)) | |
4940 | || !cp_tree_equal (r, t)); | |
21131a05 | 4941 | return r; |
4942 | } | |
4943 | else if (TREE_OVERFLOW_P (t)) | |
4944 | { | |
4945 | t = build_nop (TREE_TYPE (t), t); | |
4946 | TREE_CONSTANT (t) = false; | |
4947 | } | |
4948 | return t; | |
4949 | } | |
4950 | ||
4951 | return maybe_constant_value (t); | |
4952 | } | |
4953 | ||
09b42213 | 4954 | /* Like maybe_constant_value, but returns a CONSTRUCTOR directly, rather |
4955 | than wrapped in a TARGET_EXPR. */ | |
4956 | ||
4957 | tree | |
cf72f34d | 4958 | maybe_constant_init (tree t, tree decl) |
09b42213 | 4959 | { |
d2c63826 | 4960 | if (!t) |
4961 | return t; | |
09b42213 | 4962 | if (TREE_CODE (t) == EXPR_STMT) |
4963 | t = TREE_OPERAND (t, 0); | |
4964 | if (TREE_CODE (t) == CONVERT_EXPR | |
4965 | && VOID_TYPE_P (TREE_TYPE (t))) | |
4966 | t = TREE_OPERAND (t, 0); | |
9c96033c | 4967 | if (TREE_CODE (t) == INIT_EXPR) |
4968 | t = TREE_OPERAND (t, 1); | |
c6d97004 | 4969 | if (TREE_CODE (t) == TARGET_EXPR) |
4970 | t = TARGET_EXPR_INITIAL (t); | |
29cf24ec | 4971 | if (!potential_nondependent_static_init_expression (t)) |
2055d27a | 4972 | /* Don't try to evaluate it. */; |
b601ad30 | 4973 | else if (CONSTANT_CLASS_P (t)) |
4974 | /* No evaluation needed. */; | |
2055d27a | 4975 | else |
4976 | t = cxx_eval_outermost_constant_expr (t, true, false, decl); | |
09b42213 | 4977 | if (TREE_CODE (t) == TARGET_EXPR) |
4978 | { | |
4979 | tree init = TARGET_EXPR_INITIAL (t); | |
4980 | if (TREE_CODE (init) == CONSTRUCTOR) | |
4981 | t = init; | |
4982 | } | |
4983 | return t; | |
4984 | } | |
4985 | ||
4986 | #if 0 | |
4987 | /* FIXME see ADDR_EXPR section in potential_constant_expression_1. */ | |
4988 | /* Return true if the object referred to by REF has automatic or thread | |
4989 | local storage. */ | |
4990 | ||
4991 | enum { ck_ok, ck_bad, ck_unknown }; | |
4992 | static int | |
4993 | check_automatic_or_tls (tree ref) | |
4994 | { | |
3754d046 | 4995 | machine_mode mode; |
09b42213 | 4996 | HOST_WIDE_INT bitsize, bitpos; |
4997 | tree offset; | |
4998 | int volatilep = 0, unsignedp = 0; | |
4999 | tree decl = get_inner_reference (ref, &bitsize, &bitpos, &offset, | |
5000 | &mode, &unsignedp, &volatilep, false); | |
5001 | duration_kind dk; | |
5002 | ||
5003 | /* If there isn't a decl in the middle, we don't know the linkage here, | |
5004 | and this isn't a constant expression anyway. */ | |
5005 | if (!DECL_P (decl)) | |
5006 | return ck_unknown; | |
5007 | dk = decl_storage_duration (decl); | |
5008 | return (dk == dk_auto || dk == dk_thread) ? ck_bad : ck_ok; | |
5009 | } | |
5010 | #endif | |
5011 | ||
5012 | /* Return true if T denotes a potentially constant expression. Issue | |
5013 | diagnostic as appropriate under control of FLAGS. If WANT_RVAL is true, | |
5014 | an lvalue-rvalue conversion is implied. | |
5015 | ||
5016 | C++0x [expr.const] used to say | |
5017 | ||
5018 | 6 An expression is a potential constant expression if it is | |
5019 | a constant expression where all occurrences of function | |
5020 | parameters are replaced by arbitrary constant expressions | |
5021 | of the appropriate type. | |
5022 | ||
5023 | 2 A conditional expression is a constant expression unless it | |
5024 | involves one of the following as a potentially evaluated | |
5025 | subexpression (3.2), but subexpressions of logical AND (5.14), | |
5026 | logical OR (5.15), and conditional (5.16) operations that are | |
5027 | not evaluated are not considered. */ | |
5028 | ||
5029 | static bool | |
2055d27a | 5030 | potential_constant_expression_1 (tree t, bool want_rval, bool strict, |
5031 | tsubst_flags_t flags) | |
09b42213 | 5032 | { |
2055d27a | 5033 | #define RECUR(T,RV) potential_constant_expression_1 ((T), (RV), strict, flags) |
09b42213 | 5034 | enum { any = false, rval = true }; |
5035 | int i; | |
5036 | tree tmp; | |
5037 | ||
5038 | if (t == error_mark_node) | |
5039 | return false; | |
5040 | if (t == NULL_TREE) | |
5041 | return true; | |
d6a08f5c | 5042 | location_t loc = EXPR_LOC_OR_LOC (t, input_location); |
eade0940 | 5043 | if (TREE_THIS_VOLATILE (t) && !DECL_P (t)) |
09b42213 | 5044 | { |
5045 | if (flags & tf_error) | |
d6a08f5c | 5046 | error_at (loc, "expression %qE has side-effects", t); |
09b42213 | 5047 | return false; |
5048 | } | |
5049 | if (CONSTANT_CLASS_P (t)) | |
5050 | return true; | |
c7282bf2 | 5051 | if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_TYPED) |
5052 | && TREE_TYPE (t) == error_mark_node) | |
5053 | return false; | |
09b42213 | 5054 | |
5055 | switch (TREE_CODE (t)) | |
5056 | { | |
5057 | case FUNCTION_DECL: | |
5058 | case BASELINK: | |
5059 | case TEMPLATE_DECL: | |
5060 | case OVERLOAD: | |
5061 | case TEMPLATE_ID_EXPR: | |
5062 | case LABEL_DECL: | |
5063 | case LABEL_EXPR: | |
9c96033c | 5064 | case CASE_LABEL_EXPR: |
09b42213 | 5065 | case CONST_DECL: |
5066 | case SIZEOF_EXPR: | |
5067 | case ALIGNOF_EXPR: | |
5068 | case OFFSETOF_EXPR: | |
5069 | case NOEXCEPT_EXPR: | |
5070 | case TEMPLATE_PARM_INDEX: | |
5071 | case TRAIT_EXPR: | |
5072 | case IDENTIFIER_NODE: | |
5073 | case USERDEF_LITERAL: | |
5074 | /* We can see a FIELD_DECL in a pointer-to-member expression. */ | |
5075 | case FIELD_DECL: | |
5076 | case PARM_DECL: | |
d2c63826 | 5077 | case RESULT_DECL: |
09b42213 | 5078 | case USING_DECL: |
9c96033c | 5079 | case USING_STMT: |
cf72f34d | 5080 | case PLACEHOLDER_EXPR: |
9c96033c | 5081 | case BREAK_STMT: |
5082 | case CONTINUE_STMT: | |
56c12fd4 | 5083 | case REQUIRES_EXPR: |
33603066 | 5084 | case STATIC_ASSERT: |
09b42213 | 5085 | return true; |
5086 | ||
5087 | case AGGR_INIT_EXPR: | |
5088 | case CALL_EXPR: | |
5089 | /* -- an invocation of a function other than a constexpr function | |
5090 | or a constexpr constructor. */ | |
5091 | { | |
5092 | tree fun = get_function_named_in_call (t); | |
5093 | const int nargs = call_expr_nargs (t); | |
5094 | i = 0; | |
5095 | ||
9c96033c | 5096 | if (fun == NULL_TREE) |
5097 | { | |
732905bb | 5098 | /* Reset to allow the function to continue past the end |
5099 | of the block below. Otherwise return early. */ | |
5100 | bool bail = true; | |
5101 | ||
32cf7025 | 5102 | if (TREE_CODE (t) == CALL_EXPR |
5103 | && CALL_EXPR_FN (t) == NULL_TREE) | |
5104 | switch (CALL_EXPR_IFN (t)) | |
5105 | { | |
5106 | /* These should be ignored, they are optimized away from | |
5107 | constexpr functions. */ | |
5108 | case IFN_UBSAN_NULL: | |
5109 | case IFN_UBSAN_BOUNDS: | |
5110 | case IFN_UBSAN_VPTR: | |
3c77f69c | 5111 | case IFN_FALLTHROUGH: |
32cf7025 | 5112 | return true; |
732905bb | 5113 | |
5114 | case IFN_ADD_OVERFLOW: | |
5115 | case IFN_SUB_OVERFLOW: | |
5116 | case IFN_MUL_OVERFLOW: | |
6e1b2ffb | 5117 | case IFN_LAUNDER: |
732905bb | 5118 | bail = false; |
5119 | ||
32cf7025 | 5120 | default: |
5121 | break; | |
5122 | } | |
732905bb | 5123 | |
5124 | if (bail) | |
5125 | { | |
5126 | /* fold_call_expr can't do anything with IFN calls. */ | |
5127 | if (flags & tf_error) | |
d6a08f5c | 5128 | error_at (loc, "call to internal function %qE", t); |
732905bb | 5129 | return false; |
5130 | } | |
9c96033c | 5131 | } |
732905bb | 5132 | |
5133 | if (fun && is_overloaded_fn (fun)) | |
09b42213 | 5134 | { |
5135 | if (TREE_CODE (fun) == FUNCTION_DECL) | |
5136 | { | |
5137 | if (builtin_valid_in_constant_expr_p (fun)) | |
5138 | return true; | |
5139 | if (!DECL_DECLARED_CONSTEXPR_P (fun) | |
5140 | /* Allow any built-in function; if the expansion | |
5141 | isn't constant, we'll deal with that then. */ | |
5142 | && !is_builtin_fn (fun)) | |
5143 | { | |
5144 | if (flags & tf_error) | |
5145 | { | |
d6a08f5c | 5146 | error_at (loc, "call to non-constexpr function %qD", |
5147 | fun); | |
09b42213 | 5148 | explain_invalid_constexpr_fn (fun); |
5149 | } | |
5150 | return false; | |
5151 | } | |
5152 | /* A call to a non-static member function takes the address | |
5153 | of the object as the first argument. But in a constant | |
5154 | expression the address will be folded away, so look | |
5155 | through it now. */ | |
5156 | if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fun) | |
5157 | && !DECL_CONSTRUCTOR_P (fun)) | |
5158 | { | |
5159 | tree x = get_nth_callarg (t, 0); | |
5160 | if (is_this_parameter (x)) | |
cf72f34d | 5161 | return true; |
2055d27a | 5162 | else if (!RECUR (x, rval)) |
09b42213 | 5163 | return false; |
5164 | i = 1; | |
5165 | } | |
5166 | } | |
5167 | else | |
5168 | { | |
2055d27a | 5169 | if (!RECUR (fun, true)) |
09b42213 | 5170 | return false; |
5171 | fun = get_first_fn (fun); | |
5172 | } | |
5173 | /* Skip initial arguments to base constructors. */ | |
5174 | if (DECL_BASE_CONSTRUCTOR_P (fun)) | |
5175 | i = num_artificial_parms_for (fun); | |
5176 | fun = DECL_ORIGIN (fun); | |
5177 | } | |
732905bb | 5178 | else if (fun) |
09b42213 | 5179 | { |
2055d27a | 5180 | if (RECUR (fun, rval)) |
09b42213 | 5181 | /* Might end up being a constant function pointer. */; |
5182 | else | |
5183 | return false; | |
5184 | } | |
5185 | for (; i < nargs; ++i) | |
5186 | { | |
5187 | tree x = get_nth_callarg (t, i); | |
b2742b58 | 5188 | /* In a template, reference arguments haven't been converted to |
5189 | REFERENCE_TYPE and we might not even know if the parameter | |
5190 | is a reference, so accept lvalue constants too. */ | |
5191 | bool rv = processing_template_decl ? any : rval; | |
5192 | if (!RECUR (x, rv)) | |
09b42213 | 5193 | return false; |
5194 | } | |
5195 | return true; | |
5196 | } | |
5197 | ||
5198 | case NON_LVALUE_EXPR: | |
5199 | /* -- an lvalue-to-rvalue conversion (4.1) unless it is applied to | |
5200 | -- an lvalue of integral type that refers to a non-volatile | |
5201 | const variable or static data member initialized with | |
5202 | constant expressions, or | |
5203 | ||
5204 | -- an lvalue of literal type that refers to non-volatile | |
5205 | object defined with constexpr, or that refers to a | |
5206 | sub-object of such an object; */ | |
2055d27a | 5207 | return RECUR (TREE_OPERAND (t, 0), rval); |
09b42213 | 5208 | |
5209 | case VAR_DECL: | |
9c8aeb66 | 5210 | if (DECL_HAS_VALUE_EXPR_P (t)) |
5211 | return RECUR (DECL_VALUE_EXPR (t), rval); | |
2055d27a | 5212 | if (want_rval |
33603066 | 5213 | && !var_in_maybe_constexpr_fn (t) |
c7282bf2 | 5214 | && !type_dependent_expression_p (t) |
8d6486e1 | 5215 | && !decl_maybe_constant_var_p (t) |
2055d27a | 5216 | && (strict |
5217 | || !CP_TYPE_CONST_NON_VOLATILE_P (TREE_TYPE (t)) | |
8d6486e1 | 5218 | || (DECL_INITIAL (t) |
5219 | && !DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (t))) | |
c7282bf2 | 5220 | && COMPLETE_TYPE_P (TREE_TYPE (t)) |
5221 | && !is_really_empty_class (TREE_TYPE (t))) | |
09b42213 | 5222 | { |
5223 | if (flags & tf_error) | |
5224 | non_const_var_error (t); | |
5225 | return false; | |
5226 | } | |
5227 | return true; | |
5228 | ||
5229 | case NOP_EXPR: | |
5230 | case CONVERT_EXPR: | |
5231 | case VIEW_CONVERT_EXPR: | |
5232 | /* -- a reinterpret_cast. FIXME not implemented, and this rule | |
5233 | may change to something more specific to type-punning (DR 1312). */ | |
5234 | { | |
5235 | tree from = TREE_OPERAND (t, 0); | |
5236 | if (POINTER_TYPE_P (TREE_TYPE (t)) | |
5237 | && TREE_CODE (from) == INTEGER_CST | |
5238 | && !integer_zerop (from)) | |
5239 | { | |
5240 | if (flags & tf_error) | |
d6a08f5c | 5241 | error_at (loc, "reinterpret_cast from integer to pointer"); |
09b42213 | 5242 | return false; |
5243 | } | |
2055d27a | 5244 | return (RECUR (from, TREE_CODE (t) != VIEW_CONVERT_EXPR)); |
09b42213 | 5245 | } |
5246 | ||
cd45162d | 5247 | case ADDRESSOF_EXPR: |
5248 | /* This is like ADDR_EXPR, except it won't form pointer-to-member. */ | |
5249 | t = TREE_OPERAND (t, 0); | |
5250 | goto handle_addr_expr; | |
5251 | ||
09b42213 | 5252 | case ADDR_EXPR: |
5253 | /* -- a unary operator & that is applied to an lvalue that | |
5254 | designates an object with thread or automatic storage | |
5255 | duration; */ | |
5256 | t = TREE_OPERAND (t, 0); | |
5257 | ||
5258 | if (TREE_CODE (t) == OFFSET_REF && PTRMEM_OK_P (t)) | |
5259 | /* A pointer-to-member constant. */ | |
5260 | return true; | |
5261 | ||
cd45162d | 5262 | handle_addr_expr: |
09b42213 | 5263 | #if 0 |
5264 | /* FIXME adjust when issue 1197 is fully resolved. For now don't do | |
5265 | any checking here, as we might dereference the pointer later. If | |
5266 | we remove this code, also remove check_automatic_or_tls. */ | |
5267 | i = check_automatic_or_tls (t); | |
5268 | if (i == ck_ok) | |
5269 | return true; | |
5270 | if (i == ck_bad) | |
5271 | { | |
5272 | if (flags & tf_error) | |
5273 | error ("address-of an object %qE with thread local or " | |
5274 | "automatic storage is not a constant expression", t); | |
5275 | return false; | |
5276 | } | |
5277 | #endif | |
2055d27a | 5278 | return RECUR (t, any); |
09b42213 | 5279 | |
20b34a56 | 5280 | case REALPART_EXPR: |
5281 | case IMAGPART_EXPR: | |
09b42213 | 5282 | case COMPONENT_REF: |
5283 | case BIT_FIELD_REF: | |
5284 | case ARROW_EXPR: | |
5285 | case OFFSET_REF: | |
5286 | /* -- a class member access unless its postfix-expression is | |
5287 | of literal type or of pointer to literal type. */ | |
5288 | /* This test would be redundant, as it follows from the | |
5289 | postfix-expression being a potential constant expression. */ | |
eade0940 | 5290 | if (type_unknown_p (t)) |
5291 | return true; | |
2055d27a | 5292 | return RECUR (TREE_OPERAND (t, 0), want_rval); |
09b42213 | 5293 | |
5294 | case EXPR_PACK_EXPANSION: | |
2055d27a | 5295 | return RECUR (PACK_EXPANSION_PATTERN (t), want_rval); |
09b42213 | 5296 | |
5297 | case INDIRECT_REF: | |
5298 | { | |
5299 | tree x = TREE_OPERAND (t, 0); | |
5300 | STRIP_NOPS (x); | |
997bbf70 | 5301 | if (is_this_parameter (x) && !is_capture_proxy (x)) |
09b42213 | 5302 | { |
5303 | if (DECL_CONTEXT (x) | |
5304 | && !DECL_DECLARED_CONSTEXPR_P (DECL_CONTEXT (x))) | |
5305 | { | |
5306 | if (flags & tf_error) | |
d6a08f5c | 5307 | error_at (loc, "use of %<this%> in a constant expression"); |
09b42213 | 5308 | return false; |
5309 | } | |
09b42213 | 5310 | return true; |
5311 | } | |
2055d27a | 5312 | return RECUR (x, rval); |
09b42213 | 5313 | } |
5314 | ||
9c96033c | 5315 | case STATEMENT_LIST: |
5316 | { | |
5317 | tree_stmt_iterator i; | |
5318 | for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i)) | |
5319 | { | |
2055d27a | 5320 | if (!RECUR (tsi_stmt (i), any)) |
9c96033c | 5321 | return false; |
5322 | } | |
5323 | return true; | |
5324 | } | |
5325 | break; | |
5326 | ||
5327 | case MODIFY_EXPR: | |
5328 | if (cxx_dialect < cxx14) | |
5329 | goto fail; | |
2055d27a | 5330 | if (!RECUR (TREE_OPERAND (t, 0), any)) |
9c96033c | 5331 | return false; |
2055d27a | 5332 | if (!RECUR (TREE_OPERAND (t, 1), rval)) |
9c96033c | 5333 | return false; |
5334 | return true; | |
5335 | ||
5336 | case MODOP_EXPR: | |
5337 | if (cxx_dialect < cxx14) | |
5338 | goto fail; | |
2055d27a | 5339 | if (!RECUR (TREE_OPERAND (t, 0), rval)) |
9c96033c | 5340 | return false; |
2055d27a | 5341 | if (!RECUR (TREE_OPERAND (t, 2), rval)) |
9c96033c | 5342 | return false; |
5343 | return true; | |
5344 | ||
9c96033c | 5345 | case DO_STMT: |
2055d27a | 5346 | if (!RECUR (DO_COND (t), rval)) |
9c96033c | 5347 | return false; |
2055d27a | 5348 | if (!RECUR (DO_BODY (t), any)) |
9c96033c | 5349 | return false; |
5350 | return true; | |
5351 | ||
5352 | case FOR_STMT: | |
2055d27a | 5353 | if (!RECUR (FOR_INIT_STMT (t), any)) |
9c96033c | 5354 | return false; |
2055d27a | 5355 | if (!RECUR (FOR_COND (t), rval)) |
9c96033c | 5356 | return false; |
2055d27a | 5357 | if (!RECUR (FOR_EXPR (t), any)) |
9c96033c | 5358 | return false; |
2055d27a | 5359 | if (!RECUR (FOR_BODY (t), any)) |
9c96033c | 5360 | return false; |
5361 | return true; | |
5362 | ||
33603066 | 5363 | case RANGE_FOR_STMT: |
5364 | if (!RECUR (RANGE_FOR_EXPR (t), any)) | |
5365 | return false; | |
5366 | if (!RECUR (RANGE_FOR_BODY (t), any)) | |
5367 | return false; | |
5368 | return true; | |
5369 | ||
9c96033c | 5370 | case WHILE_STMT: |
2055d27a | 5371 | if (!RECUR (WHILE_COND (t), rval)) |
9c96033c | 5372 | return false; |
2055d27a | 5373 | if (!RECUR (WHILE_BODY (t), any)) |
9c96033c | 5374 | return false; |
5375 | return true; | |
5376 | ||
5377 | case SWITCH_STMT: | |
2055d27a | 5378 | if (!RECUR (SWITCH_STMT_COND (t), rval)) |
9c96033c | 5379 | return false; |
748c426a | 5380 | /* FIXME we don't check SWITCH_STMT_BODY currently, because even |
5381 | unreachable labels would be checked. */ | |
9c96033c | 5382 | return true; |
5383 | ||
da7981e0 | 5384 | case STMT_EXPR: |
2055d27a | 5385 | return RECUR (STMT_EXPR_STMT (t), rval); |
da7981e0 | 5386 | |
09b42213 | 5387 | case LAMBDA_EXPR: |
5388 | case DYNAMIC_CAST_EXPR: | |
5389 | case PSEUDO_DTOR_EXPR: | |
09b42213 | 5390 | case NEW_EXPR: |
5391 | case VEC_NEW_EXPR: | |
5392 | case DELETE_EXPR: | |
5393 | case VEC_DELETE_EXPR: | |
5394 | case THROW_EXPR: | |
d6a08f5c | 5395 | case OMP_PARALLEL: |
5396 | case OMP_TASK: | |
5397 | case OMP_FOR: | |
5398 | case OMP_DISTRIBUTE: | |
5399 | case OMP_TASKLOOP: | |
5400 | case OMP_TEAMS: | |
5401 | case OMP_TARGET_DATA: | |
5402 | case OMP_TARGET: | |
5403 | case OMP_SECTIONS: | |
5404 | case OMP_ORDERED: | |
5405 | case OMP_CRITICAL: | |
5406 | case OMP_SINGLE: | |
5407 | case OMP_SECTION: | |
5408 | case OMP_MASTER: | |
5409 | case OMP_TASKGROUP: | |
5410 | case OMP_TARGET_UPDATE: | |
5411 | case OMP_TARGET_ENTER_DATA: | |
5412 | case OMP_TARGET_EXIT_DATA: | |
09b42213 | 5413 | case OMP_ATOMIC: |
5414 | case OMP_ATOMIC_READ: | |
5415 | case OMP_ATOMIC_CAPTURE_OLD: | |
5416 | case OMP_ATOMIC_CAPTURE_NEW: | |
d6a08f5c | 5417 | case OACC_PARALLEL: |
5418 | case OACC_KERNELS: | |
5419 | case OACC_DATA: | |
5420 | case OACC_HOST_DATA: | |
5421 | case OACC_LOOP: | |
5422 | case OACC_CACHE: | |
5423 | case OACC_DECLARE: | |
5424 | case OACC_ENTER_DATA: | |
5425 | case OACC_EXIT_DATA: | |
5426 | case OACC_UPDATE: | |
5427 | case CILK_SIMD: | |
5428 | case CILK_FOR: | |
09b42213 | 5429 | /* GCC internal stuff. */ |
5430 | case VA_ARG_EXPR: | |
5431 | case OBJ_TYPE_REF: | |
09b42213 | 5432 | case TRANSACTION_EXPR: |
9c96033c | 5433 | case ASM_EXPR: |
9abecca2 | 5434 | case AT_ENCODE_EXPR: |
9c96033c | 5435 | fail: |
09b42213 | 5436 | if (flags & tf_error) |
d6a08f5c | 5437 | error_at (loc, "expression %qE is not a constant expression", t); |
09b42213 | 5438 | return false; |
5439 | ||
5440 | case TYPEID_EXPR: | |
5441 | /* -- a typeid expression whose operand is of polymorphic | |
5442 | class type; */ | |
5443 | { | |
5444 | tree e = TREE_OPERAND (t, 0); | |
5445 | if (!TYPE_P (e) && !type_dependent_expression_p (e) | |
5446 | && TYPE_POLYMORPHIC_P (TREE_TYPE (e))) | |
5447 | { | |
5448 | if (flags & tf_error) | |
d6a08f5c | 5449 | error_at (loc, "typeid-expression is not a constant expression " |
5450 | "because %qE is of polymorphic type", e); | |
09b42213 | 5451 | return false; |
5452 | } | |
5453 | return true; | |
5454 | } | |
5455 | ||
5456 | case MINUS_EXPR: | |
09b42213 | 5457 | want_rval = true; |
5458 | goto binary; | |
5459 | ||
5460 | case LT_EXPR: | |
5461 | case LE_EXPR: | |
5462 | case GT_EXPR: | |
5463 | case GE_EXPR: | |
5464 | case EQ_EXPR: | |
5465 | case NE_EXPR: | |
09b42213 | 5466 | want_rval = true; |
5467 | goto binary; | |
5468 | ||
9c96033c | 5469 | case PREINCREMENT_EXPR: |
5470 | case POSTINCREMENT_EXPR: | |
5471 | case PREDECREMENT_EXPR: | |
5472 | case POSTDECREMENT_EXPR: | |
5473 | if (cxx_dialect < cxx14) | |
5474 | goto fail; | |
5475 | goto unary; | |
5476 | ||
09b42213 | 5477 | case BIT_NOT_EXPR: |
5478 | /* A destructor. */ | |
5479 | if (TYPE_P (TREE_OPERAND (t, 0))) | |
5480 | return true; | |
e3533433 | 5481 | /* fall through. */ |
09b42213 | 5482 | |
09b42213 | 5483 | case CONJ_EXPR: |
5484 | case SAVE_EXPR: | |
5485 | case FIX_TRUNC_EXPR: | |
5486 | case FLOAT_EXPR: | |
5487 | case NEGATE_EXPR: | |
5488 | case ABS_EXPR: | |
5489 | case TRUTH_NOT_EXPR: | |
5490 | case FIXED_CONVERT_EXPR: | |
5491 | case UNARY_PLUS_EXPR: | |
6fdf70f5 | 5492 | case UNARY_LEFT_FOLD_EXPR: |
5493 | case UNARY_RIGHT_FOLD_EXPR: | |
9c96033c | 5494 | unary: |
2055d27a | 5495 | return RECUR (TREE_OPERAND (t, 0), rval); |
09b42213 | 5496 | |
5497 | case CAST_EXPR: | |
5498 | case CONST_CAST_EXPR: | |
5499 | case STATIC_CAST_EXPR: | |
5500 | case REINTERPRET_CAST_EXPR: | |
5501 | case IMPLICIT_CONV_EXPR: | |
5502 | if (cxx_dialect < cxx11 | |
5503 | && !dependent_type_p (TREE_TYPE (t)) | |
5504 | && !INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))) | |
5505 | /* In C++98, a conversion to non-integral type can't be part of a | |
5506 | constant expression. */ | |
5507 | { | |
5508 | if (flags & tf_error) | |
d6a08f5c | 5509 | error_at (loc, |
5510 | "cast to non-integral type %qT in a constant expression", | |
5511 | TREE_TYPE (t)); | |
09b42213 | 5512 | return false; |
5513 | } | |
5514 | ||
2055d27a | 5515 | return (RECUR (TREE_OPERAND (t, 0), |
5516 | TREE_CODE (TREE_TYPE (t)) != REFERENCE_TYPE)); | |
09b42213 | 5517 | |
9c96033c | 5518 | case BIND_EXPR: |
2055d27a | 5519 | return RECUR (BIND_EXPR_BODY (t), want_rval); |
9c96033c | 5520 | |
5521 | case WITH_CLEANUP_EXPR: | |
5522 | case CLEANUP_POINT_EXPR: | |
5523 | case MUST_NOT_THROW_EXPR: | |
5524 | case TRY_CATCH_EXPR: | |
7f67d68c | 5525 | case TRY_BLOCK: |
9c96033c | 5526 | case EH_SPEC_BLOCK: |
5527 | case EXPR_STMT: | |
09b42213 | 5528 | case PAREN_EXPR: |
5529 | case NON_DEPENDENT_EXPR: | |
5530 | /* For convenience. */ | |
5531 | case RETURN_EXPR: | |
d1980671 | 5532 | case LOOP_EXPR: |
5533 | case EXIT_EXPR: | |
2055d27a | 5534 | return RECUR (TREE_OPERAND (t, 0), want_rval); |
09b42213 | 5535 | |
33603066 | 5536 | case DECL_EXPR: |
5537 | tmp = DECL_EXPR_DECL (t); | |
5538 | if (VAR_P (tmp) && !DECL_ARTIFICIAL (tmp)) | |
5539 | { | |
5540 | if (TREE_STATIC (tmp)) | |
5541 | { | |
5542 | if (flags & tf_error) | |
5543 | error_at (DECL_SOURCE_LOCATION (tmp), "%qD declared " | |
8d6486e1 | 5544 | "%<static%> in %<constexpr%> context", tmp); |
33603066 | 5545 | return false; |
5546 | } | |
5547 | else if (CP_DECL_THREAD_LOCAL_P (tmp)) | |
5548 | { | |
5549 | if (flags & tf_error) | |
5550 | error_at (DECL_SOURCE_LOCATION (tmp), "%qD declared " | |
8d6486e1 | 5551 | "%<thread_local%> in %<constexpr%> context", tmp); |
33603066 | 5552 | return false; |
5553 | } | |
5554 | else if (!DECL_NONTRIVIALLY_INITIALIZED_P (tmp)) | |
5555 | { | |
5556 | if (flags & tf_error) | |
5557 | error_at (DECL_SOURCE_LOCATION (tmp), "uninitialized " | |
8d6486e1 | 5558 | "variable %qD in %<constexpr%> context", tmp); |
33603066 | 5559 | return false; |
5560 | } | |
5561 | } | |
5562 | return RECUR (tmp, want_rval); | |
5563 | ||
7f67d68c | 5564 | case TRY_FINALLY_EXPR: |
5565 | return (RECUR (TREE_OPERAND (t, 0), want_rval) | |
5566 | && RECUR (TREE_OPERAND (t, 1), any)); | |
5567 | ||
09b42213 | 5568 | case SCOPE_REF: |
2055d27a | 5569 | return RECUR (TREE_OPERAND (t, 1), want_rval); |
09b42213 | 5570 | |
5571 | case TARGET_EXPR: | |
5572 | if (!literal_type_p (TREE_TYPE (t))) | |
5573 | { | |
5574 | if (flags & tf_error) | |
5575 | { | |
d6a08f5c | 5576 | error_at (loc, "temporary of non-literal type %qT in a " |
5577 | "constant expression", TREE_TYPE (t)); | |
09b42213 | 5578 | explain_non_literal_class (TREE_TYPE (t)); |
5579 | } | |
5580 | return false; | |
5581 | } | |
e3533433 | 5582 | /* FALLTHRU */ |
09b42213 | 5583 | case INIT_EXPR: |
2055d27a | 5584 | return RECUR (TREE_OPERAND (t, 1), rval); |
09b42213 | 5585 | |
5586 | case CONSTRUCTOR: | |
5587 | { | |
5588 | vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (t); | |
5589 | constructor_elt *ce; | |
5590 | for (i = 0; vec_safe_iterate (v, i, &ce); ++i) | |
2055d27a | 5591 | if (!RECUR (ce->value, want_rval)) |
09b42213 | 5592 | return false; |
5593 | return true; | |
5594 | } | |
5595 | ||
5596 | case TREE_LIST: | |
5597 | { | |
5598 | gcc_assert (TREE_PURPOSE (t) == NULL_TREE | |
5599 | || DECL_P (TREE_PURPOSE (t))); | |
2055d27a | 5600 | if (!RECUR (TREE_VALUE (t), want_rval)) |
09b42213 | 5601 | return false; |
5602 | if (TREE_CHAIN (t) == NULL_TREE) | |
5603 | return true; | |
2055d27a | 5604 | return RECUR (TREE_CHAIN (t), want_rval); |
09b42213 | 5605 | } |
5606 | ||
5607 | case TRUNC_DIV_EXPR: | |
5608 | case CEIL_DIV_EXPR: | |
5609 | case FLOOR_DIV_EXPR: | |
5610 | case ROUND_DIV_EXPR: | |
5611 | case TRUNC_MOD_EXPR: | |
5612 | case CEIL_MOD_EXPR: | |
5613 | case ROUND_MOD_EXPR: | |
5614 | { | |
5615 | tree denom = TREE_OPERAND (t, 1); | |
2055d27a | 5616 | if (!RECUR (denom, rval)) |
09b42213 | 5617 | return false; |
5618 | /* We can't call cxx_eval_outermost_constant_expr on an expression | |
21131a05 | 5619 | that hasn't been through instantiate_non_dependent_expr yet. */ |
09b42213 | 5620 | if (!processing_template_decl) |
5621 | denom = cxx_eval_outermost_constant_expr (denom, true); | |
5622 | if (integer_zerop (denom)) | |
5623 | { | |
5624 | if (flags & tf_error) | |
ea034e2c | 5625 | error ("division by zero is not a constant expression"); |
09b42213 | 5626 | return false; |
5627 | } | |
5628 | else | |
5629 | { | |
5630 | want_rval = true; | |
2055d27a | 5631 | return RECUR (TREE_OPERAND (t, 0), want_rval); |
09b42213 | 5632 | } |
5633 | } | |
5634 | ||
5635 | case COMPOUND_EXPR: | |
5636 | { | |
5637 | /* check_return_expr sometimes wraps a TARGET_EXPR in a | |
5638 | COMPOUND_EXPR; don't get confused. Also handle EMPTY_CLASS_EXPR | |
5639 | introduced by build_call_a. */ | |
5640 | tree op0 = TREE_OPERAND (t, 0); | |
5641 | tree op1 = TREE_OPERAND (t, 1); | |
5642 | STRIP_NOPS (op1); | |
5643 | if ((TREE_CODE (op0) == TARGET_EXPR && op1 == TARGET_EXPR_SLOT (op0)) | |
5644 | || TREE_CODE (op1) == EMPTY_CLASS_EXPR) | |
2055d27a | 5645 | return RECUR (op0, want_rval); |
09b42213 | 5646 | else |
5647 | goto binary; | |
5648 | } | |
5649 | ||
5650 | /* If the first operand is the non-short-circuit constant, look at | |
5651 | the second operand; otherwise we only care about the first one for | |
5652 | potentiality. */ | |
5653 | case TRUTH_AND_EXPR: | |
5654 | case TRUTH_ANDIF_EXPR: | |
5655 | tmp = boolean_true_node; | |
5656 | goto truth; | |
5657 | case TRUTH_OR_EXPR: | |
5658 | case TRUTH_ORIF_EXPR: | |
5659 | tmp = boolean_false_node; | |
5660 | truth: | |
5661 | { | |
5662 | tree op = TREE_OPERAND (t, 0); | |
2055d27a | 5663 | if (!RECUR (op, rval)) |
09b42213 | 5664 | return false; |
5665 | if (!processing_template_decl) | |
5666 | op = cxx_eval_outermost_constant_expr (op, true); | |
5667 | if (tree_int_cst_equal (op, tmp)) | |
2055d27a | 5668 | return RECUR (TREE_OPERAND (t, 1), rval); |
09b42213 | 5669 | else |
5670 | return true; | |
5671 | } | |
5672 | ||
5673 | case PLUS_EXPR: | |
5674 | case MULT_EXPR: | |
5675 | case POINTER_PLUS_EXPR: | |
5676 | case RDIV_EXPR: | |
5677 | case EXACT_DIV_EXPR: | |
5678 | case MIN_EXPR: | |
5679 | case MAX_EXPR: | |
5680 | case LSHIFT_EXPR: | |
5681 | case RSHIFT_EXPR: | |
5682 | case LROTATE_EXPR: | |
5683 | case RROTATE_EXPR: | |
5684 | case BIT_IOR_EXPR: | |
5685 | case BIT_XOR_EXPR: | |
5686 | case BIT_AND_EXPR: | |
5687 | case TRUTH_XOR_EXPR: | |
5688 | case UNORDERED_EXPR: | |
5689 | case ORDERED_EXPR: | |
5690 | case UNLT_EXPR: | |
5691 | case UNLE_EXPR: | |
5692 | case UNGT_EXPR: | |
5693 | case UNGE_EXPR: | |
5694 | case UNEQ_EXPR: | |
5695 | case LTGT_EXPR: | |
5696 | case RANGE_EXPR: | |
5697 | case COMPLEX_EXPR: | |
5698 | want_rval = true; | |
5699 | /* Fall through. */ | |
5700 | case ARRAY_REF: | |
5701 | case ARRAY_RANGE_REF: | |
5702 | case MEMBER_REF: | |
5703 | case DOTSTAR_EXPR: | |
f0abe78f | 5704 | case MEM_REF: |
6fdf70f5 | 5705 | case BINARY_LEFT_FOLD_EXPR: |
5706 | case BINARY_RIGHT_FOLD_EXPR: | |
09b42213 | 5707 | binary: |
5708 | for (i = 0; i < 2; ++i) | |
2055d27a | 5709 | if (!RECUR (TREE_OPERAND (t, i), want_rval)) |
09b42213 | 5710 | return false; |
5711 | return true; | |
5712 | ||
5713 | case CILK_SYNC_STMT: | |
5714 | case CILK_SPAWN_STMT: | |
5715 | case ARRAY_NOTATION_REF: | |
5716 | return false; | |
5717 | ||
5718 | case FMA_EXPR: | |
5719 | case VEC_PERM_EXPR: | |
5720 | for (i = 0; i < 3; ++i) | |
2055d27a | 5721 | if (!RECUR (TREE_OPERAND (t, i), true)) |
09b42213 | 5722 | return false; |
5723 | return true; | |
5724 | ||
5725 | case COND_EXPR: | |
b0fe8b95 | 5726 | if (COND_EXPR_IS_VEC_DELETE (t)) |
5727 | { | |
5728 | if (flags & tf_error) | |
d6a08f5c | 5729 | error_at (loc, "%<delete[]%> is not a constant expression"); |
b0fe8b95 | 5730 | return false; |
5731 | } | |
5732 | /* Fall through. */ | |
5733 | case IF_STMT: | |
09b42213 | 5734 | case VEC_COND_EXPR: |
5735 | /* If the condition is a known constant, we know which of the legs we | |
5736 | care about; otherwise we only require that the condition and | |
5737 | either of the legs be potentially constant. */ | |
5738 | tmp = TREE_OPERAND (t, 0); | |
2055d27a | 5739 | if (!RECUR (tmp, rval)) |
09b42213 | 5740 | return false; |
5741 | if (!processing_template_decl) | |
5742 | tmp = cxx_eval_outermost_constant_expr (tmp, true); | |
5743 | if (integer_zerop (tmp)) | |
2055d27a | 5744 | return RECUR (TREE_OPERAND (t, 2), want_rval); |
09b42213 | 5745 | else if (TREE_CODE (tmp) == INTEGER_CST) |
2055d27a | 5746 | return RECUR (TREE_OPERAND (t, 1), want_rval); |
09b42213 | 5747 | for (i = 1; i < 3; ++i) |
5748 | if (potential_constant_expression_1 (TREE_OPERAND (t, i), | |
2055d27a | 5749 | want_rval, strict, tf_none)) |
09b42213 | 5750 | return true; |
5751 | if (flags & tf_error) | |
d6a08f5c | 5752 | error_at (loc, "expression %qE is not a constant expression", t); |
09b42213 | 5753 | return false; |
5754 | ||
5755 | case VEC_INIT_EXPR: | |
5756 | if (VEC_INIT_EXPR_IS_CONSTEXPR (t)) | |
5757 | return true; | |
5758 | if (flags & tf_error) | |
5759 | { | |
d6a08f5c | 5760 | error_at (loc, "non-constant array initialization"); |
09b42213 | 5761 | diagnose_non_constexpr_vec_init (t); |
5762 | } | |
5763 | return false; | |
5764 | ||
db1ae94f | 5765 | case TYPE_DECL: |
5766 | case TAG_DEFN: | |
5767 | /* We can see these in statement-expressions. */ | |
5768 | return true; | |
5769 | ||
fd130325 | 5770 | case CLEANUP_STMT: |
d2c63826 | 5771 | case EMPTY_CLASS_EXPR: |
5772 | return false; | |
5773 | ||
d1980671 | 5774 | case GOTO_EXPR: |
5775 | { | |
5776 | tree *target = &TREE_OPERAND (t, 0); | |
d40a1eac | 5777 | /* Gotos representing break and continue are OK. */ |
5778 | if (breaks (target) || continues (target)) | |
5779 | return true; | |
5780 | if (flags & tf_error) | |
d6a08f5c | 5781 | error_at (loc, "%<goto%> is not a constant expression"); |
d40a1eac | 5782 | return false; |
d1980671 | 5783 | } |
5784 | ||
24c6ee98 | 5785 | case ANNOTATE_EXPR: |
5786 | gcc_assert (tree_to_uhwi (TREE_OPERAND (t, 1)) == annot_expr_ivdep_kind); | |
5787 | return RECUR (TREE_OPERAND (t, 0), rval); | |
5788 | ||
09b42213 | 5789 | default: |
5790 | if (objc_is_property_ref (t)) | |
5791 | return false; | |
5792 | ||
5793 | sorry ("unexpected AST of kind %s", get_tree_code_name (TREE_CODE (t))); | |
d40a1eac | 5794 | gcc_unreachable (); |
09b42213 | 5795 | return false; |
5796 | } | |
2055d27a | 5797 | #undef RECUR |
09b42213 | 5798 | } |
5799 | ||
5800 | /* The main entry point to the above. */ | |
5801 | ||
5802 | bool | |
5803 | potential_constant_expression (tree t) | |
5804 | { | |
2055d27a | 5805 | return potential_constant_expression_1 (t, false, true, tf_none); |
5806 | } | |
5807 | ||
5808 | bool | |
5809 | potential_static_init_expression (tree t) | |
5810 | { | |
5811 | return potential_constant_expression_1 (t, false, false, tf_none); | |
09b42213 | 5812 | } |
5813 | ||
5814 | /* As above, but require a constant rvalue. */ | |
5815 | ||
5816 | bool | |
5817 | potential_rvalue_constant_expression (tree t) | |
5818 | { | |
2055d27a | 5819 | return potential_constant_expression_1 (t, true, true, tf_none); |
09b42213 | 5820 | } |
5821 | ||
5822 | /* Like above, but complain about non-constant expressions. */ | |
5823 | ||
5824 | bool | |
5825 | require_potential_constant_expression (tree t) | |
5826 | { | |
2055d27a | 5827 | return potential_constant_expression_1 (t, false, true, tf_warning_or_error); |
09b42213 | 5828 | } |
5829 | ||
5830 | /* Cross product of the above. */ | |
5831 | ||
5832 | bool | |
5833 | require_potential_rvalue_constant_expression (tree t) | |
5834 | { | |
2055d27a | 5835 | return potential_constant_expression_1 (t, true, true, tf_warning_or_error); |
09b42213 | 5836 | } |
5837 | ||
29cf24ec | 5838 | /* Returns true if T is a potential constant expression that is not |
5839 | instantiation-dependent, and therefore a candidate for constant folding even | |
5840 | in a template. */ | |
5841 | ||
5842 | bool | |
5843 | potential_nondependent_constant_expression (tree t) | |
5844 | { | |
5845 | return (!type_unknown_p (t) | |
5846 | && !BRACE_ENCLOSED_INITIALIZER_P (t) | |
5847 | && potential_constant_expression (t) | |
5848 | && !instantiation_dependent_expression_p (t)); | |
5849 | } | |
5850 | ||
5851 | /* Returns true if T is a potential static initializer expression that is not | |
5852 | instantiation-dependent. */ | |
5853 | ||
5854 | bool | |
5855 | potential_nondependent_static_init_expression (tree t) | |
5856 | { | |
5857 | return (!type_unknown_p (t) | |
5858 | && !BRACE_ENCLOSED_INITIALIZER_P (t) | |
5859 | && potential_static_init_expression (t) | |
5860 | && !instantiation_dependent_expression_p (t)); | |
5861 | } | |
5862 | ||
a050099a | 5863 | /* Finalize constexpr processing after parsing. */ |
5864 | ||
5865 | void | |
5866 | fini_constexpr (void) | |
5867 | { | |
5868 | /* The contexpr call and fundef copies tables are no longer needed. */ | |
5869 | constexpr_call_table = NULL; | |
5870 | fundef_copies_table = NULL; | |
5871 | } | |
5872 | ||
09b42213 | 5873 | #include "gt-cp-constexpr.h" |