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Commit | Line | Data |
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13f649f6 JM |
1 | /* Perform -*- C++ -*- constant expression evaluation, including calls to |
2 | constexpr functions. These routines are used both during actual parsing | |
2d76680f PC |
3 | and during the instantiation of template functions. |
4 | ||
cbe34bb5 | 5 | Copyright (C) 1998-2017 Free Software Foundation, Inc. |
2d76680f PC |
6 | |
7 | This file is part of GCC. | |
8 | ||
9 | GCC is free software; you can redistribute it and/or modify it | |
10 | under the terms of the GNU General Public License as published by | |
11 | the Free Software Foundation; either version 3, or (at your option) | |
12 | any later version. | |
13 | ||
14 | GCC is distributed in the hope that it will be useful, but | |
15 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
17 | General Public License for more details. | |
18 | ||
19 | You should have received a copy of the GNU General Public License | |
20 | along with GCC; see the file COPYING3. If not see | |
21 | <http://www.gnu.org/licenses/>. */ | |
22 | ||
23 | #include "config.h" | |
24 | #include "system.h" | |
25 | #include "coretypes.h" | |
2d76680f | 26 | #include "cp-tree.h" |
2adfab87 | 27 | #include "varasm.h" |
2d76680f PC |
28 | #include "c-family/c-objc.h" |
29 | #include "tree-iterator.h" | |
30 | #include "gimplify.h" | |
31 | #include "builtins.h" | |
60813a46 | 32 | #include "tree-inline.h" |
0b274c17 | 33 | #include "ubsan.h" |
44a845ca | 34 | #include "gimple-fold.h" |
8108ea30 | 35 | #include "timevar.h" |
2d76680f PC |
36 | |
37 | static bool verify_constant (tree, bool, bool *, bool *); | |
38 | #define VERIFY_CONSTANT(X) \ | |
39 | do { \ | |
2b3ab879 | 40 | if (verify_constant ((X), ctx->quiet, non_constant_p, overflow_p)) \ |
2d76680f PC |
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) | |
b55b02ea | 62 | || VECTOR_TYPE_P (t) |
e42c407c MP |
63 | || TREE_CODE (t) == REFERENCE_TYPE |
64 | || (VOID_TYPE_P (t) && cxx_dialect >= cxx14)) | |
2d76680f PC |
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)) | |
f1eac182 | 96 | { |
84fa214d ML |
97 | error ("the type %qT of %<constexpr%> variable %qD " |
98 | "is not literal", type, decl); | |
f1eac182 JM |
99 | explain_non_literal_class (type); |
100 | } | |
2d76680f | 101 | else |
60813a46 | 102 | { |
5d4e573b | 103 | if (!is_instantiation_of_constexpr (current_function_decl)) |
f1eac182 JM |
104 | { |
105 | error ("variable %qD of non-literal type %qT in %<constexpr%> " | |
106 | "function", decl, type); | |
107 | explain_non_literal_class (type); | |
108 | } | |
60813a46 JM |
109 | cp_function_chain->invalid_constexpr = true; |
110 | } | |
2d76680f PC |
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 | ||
ca752f39 | 124 | struct constexpr_fundef_hasher : ggc_ptr_hash<constexpr_fundef> |
2d76680f PC |
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 | ||
98e5a19a | 170 | bool |
2d76680f PC |
171 | is_valid_constexpr_fn (tree fun, bool complain) |
172 | { | |
173 | bool ret = true; | |
174 | ||
31f7f784 | 175 | if (DECL_INHERITED_CTOR (fun) |
2d76680f PC |
176 | && TREE_CODE (fun) == TEMPLATE_DECL) |
177 | { | |
178 | ret = false; | |
179 | if (complain) | |
84fa214d | 180 | error ("inherited constructor %qD is not %<constexpr%>", |
31f7f784 | 181 | DECL_INHERITED_CTOR (fun)); |
2d76680f PC |
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 | { | |
84fa214d | 192 | error ("invalid type for parameter %d of %<constexpr%> " |
2d76680f PC |
193 | "function %q+#D", DECL_PARM_INDEX (parm), fun); |
194 | explain_non_literal_class (TREE_TYPE (parm)); | |
195 | } | |
196 | } | |
197 | } | |
198 | ||
e1bea341 JM |
199 | if (LAMBDA_TYPE_P (CP_DECL_CONTEXT (fun)) && cxx_dialect < cxx17) |
200 | { | |
201 | ret = false; | |
202 | if (complain) | |
203 | inform (DECL_SOURCE_LOCATION (fun), | |
84fa214d | 204 | "lambdas are implicitly %<constexpr%> only in C++17 and later"); |
e1bea341 JM |
205 | } |
206 | else if (!DECL_CONSTRUCTOR_P (fun)) | |
2d76680f PC |
207 | { |
208 | tree rettype = TREE_TYPE (TREE_TYPE (fun)); | |
209 | if (!literal_type_p (rettype)) | |
210 | { | |
211 | ret = false; | |
212 | if (complain) | |
213 | { | |
84fa214d | 214 | error ("invalid return type %qT of %<constexpr%> function %q+D", |
2d76680f PC |
215 | rettype, fun); |
216 | explain_non_literal_class (rettype); | |
217 | } | |
218 | } | |
219 | ||
54069e59 JM |
220 | /* C++14 DR 1684 removed this restriction. */ |
221 | if (cxx_dialect < cxx14 | |
222 | && DECL_NONSTATIC_MEMBER_FUNCTION_P (fun) | |
2d76680f PC |
223 | && !CLASSTYPE_LITERAL_P (DECL_CONTEXT (fun))) |
224 | { | |
225 | ret = false; | |
54069e59 JM |
226 | if (complain |
227 | && pedwarn (DECL_SOURCE_LOCATION (fun), OPT_Wpedantic, | |
84fa214d | 228 | "enclosing class of %<constexpr%> non-static member " |
54069e59 JM |
229 | "function %q+#D is not a literal type", fun)) |
230 | explain_non_literal_class (DECL_CONTEXT (fun)); | |
2d76680f PC |
231 | } |
232 | } | |
233 | else if (CLASSTYPE_VBASECLASSES (DECL_CONTEXT (fun))) | |
234 | { | |
235 | ret = false; | |
236 | if (complain) | |
237 | error ("%q#T has virtual base classes", DECL_CONTEXT (fun)); | |
238 | } | |
239 | ||
240 | return ret; | |
241 | } | |
242 | ||
243 | /* Subroutine of build_data_member_initialization. MEMBER is a COMPONENT_REF | |
244 | for a member of an anonymous aggregate, INIT is the initializer for that | |
245 | member, and VEC_OUTER is the vector of constructor elements for the class | |
246 | whose constructor we are processing. Add the initializer to the vector | |
247 | and return true to indicate success. */ | |
248 | ||
249 | static bool | |
250 | build_anon_member_initialization (tree member, tree init, | |
251 | vec<constructor_elt, va_gc> **vec_outer) | |
252 | { | |
253 | /* MEMBER presents the relevant fields from the inside out, but we need | |
254 | to build up the initializer from the outside in so that we can reuse | |
255 | previously built CONSTRUCTORs if this is, say, the second field in an | |
256 | anonymous struct. So we use a vec as a stack. */ | |
257 | auto_vec<tree, 2> fields; | |
258 | do | |
259 | { | |
260 | fields.safe_push (TREE_OPERAND (member, 1)); | |
261 | member = TREE_OPERAND (member, 0); | |
262 | } | |
263 | while (ANON_AGGR_TYPE_P (TREE_TYPE (member)) | |
264 | && TREE_CODE (member) == COMPONENT_REF); | |
265 | ||
266 | /* VEC has the constructor elements vector for the context of FIELD. | |
267 | If FIELD is an anonymous aggregate, we will push inside it. */ | |
268 | vec<constructor_elt, va_gc> **vec = vec_outer; | |
269 | tree field; | |
270 | while (field = fields.pop(), | |
271 | ANON_AGGR_TYPE_P (TREE_TYPE (field))) | |
272 | { | |
273 | tree ctor; | |
274 | /* If there is already an outer constructor entry for the anonymous | |
275 | aggregate FIELD, use it; otherwise, insert one. */ | |
276 | if (vec_safe_is_empty (*vec) | |
277 | || (*vec)->last().index != field) | |
278 | { | |
279 | ctor = build_constructor (TREE_TYPE (field), NULL); | |
280 | CONSTRUCTOR_APPEND_ELT (*vec, field, ctor); | |
281 | } | |
282 | else | |
283 | ctor = (*vec)->last().value; | |
284 | vec = &CONSTRUCTOR_ELTS (ctor); | |
285 | } | |
286 | ||
287 | /* Now we're at the innermost field, the one that isn't an anonymous | |
288 | aggregate. Add its initializer to the CONSTRUCTOR and we're done. */ | |
289 | gcc_assert (fields.is_empty()); | |
290 | CONSTRUCTOR_APPEND_ELT (*vec, field, init); | |
291 | ||
292 | return true; | |
293 | } | |
294 | ||
295 | /* Subroutine of build_constexpr_constructor_member_initializers. | |
296 | The expression tree T represents a data member initialization | |
297 | in a (constexpr) constructor definition. Build a pairing of | |
298 | the data member with its initializer, and prepend that pair | |
299 | to the existing initialization pair INITS. */ | |
300 | ||
301 | static bool | |
302 | build_data_member_initialization (tree t, vec<constructor_elt, va_gc> **vec) | |
303 | { | |
304 | tree member, init; | |
305 | if (TREE_CODE (t) == CLEANUP_POINT_EXPR) | |
306 | t = TREE_OPERAND (t, 0); | |
307 | if (TREE_CODE (t) == EXPR_STMT) | |
308 | t = TREE_OPERAND (t, 0); | |
309 | if (t == error_mark_node) | |
310 | return false; | |
311 | if (TREE_CODE (t) == STATEMENT_LIST) | |
312 | { | |
313 | tree_stmt_iterator i; | |
314 | for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i)) | |
315 | { | |
316 | if (! build_data_member_initialization (tsi_stmt (i), vec)) | |
317 | return false; | |
318 | } | |
319 | return true; | |
320 | } | |
321 | if (TREE_CODE (t) == CLEANUP_STMT) | |
322 | { | |
323 | /* We can't see a CLEANUP_STMT in a constructor for a literal class, | |
324 | but we can in a constexpr constructor for a non-literal class. Just | |
325 | ignore it; either all the initialization will be constant, in which | |
326 | case the cleanup can't run, or it can't be constexpr. | |
327 | Still recurse into CLEANUP_BODY. */ | |
328 | return build_data_member_initialization (CLEANUP_BODY (t), vec); | |
329 | } | |
330 | if (TREE_CODE (t) == CONVERT_EXPR) | |
331 | t = TREE_OPERAND (t, 0); | |
332 | if (TREE_CODE (t) == INIT_EXPR | |
60813a46 JM |
333 | /* vptr initialization shows up as a MODIFY_EXPR. In C++14 we only |
334 | use what this function builds for cx_check_missing_mem_inits, and | |
335 | assignment in the ctor body doesn't count. */ | |
336 | || (cxx_dialect < cxx14 && TREE_CODE (t) == MODIFY_EXPR)) | |
2d76680f PC |
337 | { |
338 | member = TREE_OPERAND (t, 0); | |
339 | init = break_out_target_exprs (TREE_OPERAND (t, 1)); | |
340 | } | |
341 | else if (TREE_CODE (t) == CALL_EXPR) | |
342 | { | |
60813a46 JM |
343 | tree fn = get_callee_fndecl (t); |
344 | if (!fn || !DECL_CONSTRUCTOR_P (fn)) | |
345 | /* We're only interested in calls to subobject constructors. */ | |
346 | return true; | |
2d76680f PC |
347 | member = CALL_EXPR_ARG (t, 0); |
348 | /* We don't use build_cplus_new here because it complains about | |
349 | abstract bases. Leaving the call unwrapped means that it has the | |
350 | wrong type, but cxx_eval_constant_expression doesn't care. */ | |
351 | init = break_out_target_exprs (t); | |
352 | } | |
353 | else if (TREE_CODE (t) == BIND_EXPR) | |
354 | return build_data_member_initialization (BIND_EXPR_BODY (t), vec); | |
2d76680f | 355 | else |
60813a46 JM |
356 | /* Don't add anything else to the CONSTRUCTOR. */ |
357 | return true; | |
2d76680f PC |
358 | if (INDIRECT_REF_P (member)) |
359 | member = TREE_OPERAND (member, 0); | |
360 | if (TREE_CODE (member) == NOP_EXPR) | |
361 | { | |
362 | tree op = member; | |
363 | STRIP_NOPS (op); | |
364 | if (TREE_CODE (op) == ADDR_EXPR) | |
365 | { | |
366 | gcc_assert (same_type_ignoring_top_level_qualifiers_p | |
367 | (TREE_TYPE (TREE_TYPE (op)), | |
368 | TREE_TYPE (TREE_TYPE (member)))); | |
369 | /* Initializing a cv-qualified member; we need to look through | |
370 | the const_cast. */ | |
371 | member = op; | |
372 | } | |
373 | else if (op == current_class_ptr | |
374 | && (same_type_ignoring_top_level_qualifiers_p | |
375 | (TREE_TYPE (TREE_TYPE (member)), | |
376 | current_class_type))) | |
377 | /* Delegating constructor. */ | |
378 | member = op; | |
379 | else | |
380 | { | |
381 | /* This is an initializer for an empty base; keep it for now so | |
382 | we can check it in cxx_eval_bare_aggregate. */ | |
383 | gcc_assert (is_empty_class (TREE_TYPE (TREE_TYPE (member)))); | |
384 | } | |
385 | } | |
386 | if (TREE_CODE (member) == ADDR_EXPR) | |
387 | member = TREE_OPERAND (member, 0); | |
388 | if (TREE_CODE (member) == COMPONENT_REF) | |
389 | { | |
390 | tree aggr = TREE_OPERAND (member, 0); | |
8cb7aaa1 JM |
391 | if (TREE_CODE (aggr) == VAR_DECL) |
392 | /* Initializing a local variable, don't add anything. */ | |
393 | return true; | |
2d76680f PC |
394 | if (TREE_CODE (aggr) != COMPONENT_REF) |
395 | /* Normal member initialization. */ | |
396 | member = TREE_OPERAND (member, 1); | |
397 | else if (ANON_AGGR_TYPE_P (TREE_TYPE (aggr))) | |
398 | /* Initializing a member of an anonymous union. */ | |
399 | return build_anon_member_initialization (member, init, vec); | |
400 | else | |
401 | /* We're initializing a vtable pointer in a base. Leave it as | |
402 | COMPONENT_REF so we remember the path to get to the vfield. */ | |
403 | gcc_assert (TREE_TYPE (member) == vtbl_ptr_type_node); | |
404 | } | |
405 | ||
49b5925f JM |
406 | /* Value-initialization can produce multiple initializers for the |
407 | same field; use the last one. */ | |
408 | if (!vec_safe_is_empty (*vec) && (*vec)->last().index == member) | |
409 | (*vec)->last().value = init; | |
410 | else | |
411 | CONSTRUCTOR_APPEND_ELT (*vec, member, init); | |
2d76680f PC |
412 | return true; |
413 | } | |
414 | ||
415 | /* Subroutine of check_constexpr_ctor_body_1 and constexpr_fn_retval. | |
416 | In C++11 mode checks that the TYPE_DECLs in the BIND_EXPR_VARS of a | |
417 | BIND_EXPR conform to 7.1.5/3/4 on typedef and alias declarations. */ | |
418 | ||
419 | static bool | |
420 | check_constexpr_bind_expr_vars (tree t) | |
421 | { | |
422 | gcc_assert (TREE_CODE (t) == BIND_EXPR); | |
423 | ||
2d76680f PC |
424 | for (tree var = BIND_EXPR_VARS (t); var; var = DECL_CHAIN (var)) |
425 | if (TREE_CODE (var) == TYPE_DECL | |
4414e22e PC |
426 | && DECL_IMPLICIT_TYPEDEF_P (var) |
427 | && !LAMBDA_TYPE_P (TREE_TYPE (var))) | |
2d76680f PC |
428 | return false; |
429 | return true; | |
430 | } | |
431 | ||
432 | /* Subroutine of check_constexpr_ctor_body. */ | |
433 | ||
434 | static bool | |
435 | check_constexpr_ctor_body_1 (tree last, tree list) | |
436 | { | |
437 | switch (TREE_CODE (list)) | |
438 | { | |
439 | case DECL_EXPR: | |
a0008434 MP |
440 | if (TREE_CODE (DECL_EXPR_DECL (list)) == USING_DECL |
441 | || TREE_CODE (DECL_EXPR_DECL (list)) == TYPE_DECL) | |
2d76680f | 442 | return true; |
2d76680f PC |
443 | return false; |
444 | ||
445 | case CLEANUP_POINT_EXPR: | |
446 | return check_constexpr_ctor_body (last, TREE_OPERAND (list, 0), | |
447 | /*complain=*/false); | |
448 | ||
449 | case BIND_EXPR: | |
450 | if (!check_constexpr_bind_expr_vars (list) | |
451 | || !check_constexpr_ctor_body (last, BIND_EXPR_BODY (list), | |
452 | /*complain=*/false)) | |
453 | return false; | |
454 | return true; | |
455 | ||
456 | case USING_STMT: | |
457 | case STATIC_ASSERT: | |
458 | return true; | |
459 | ||
460 | default: | |
461 | return false; | |
462 | } | |
463 | } | |
464 | ||
465 | /* Make sure that there are no statements after LAST in the constructor | |
466 | body represented by LIST. */ | |
467 | ||
468 | bool | |
469 | check_constexpr_ctor_body (tree last, tree list, bool complain) | |
470 | { | |
60813a46 JM |
471 | /* C++14 doesn't require a constexpr ctor to have an empty body. */ |
472 | if (cxx_dialect >= cxx14) | |
473 | return true; | |
474 | ||
2d76680f PC |
475 | bool ok = true; |
476 | if (TREE_CODE (list) == STATEMENT_LIST) | |
477 | { | |
478 | tree_stmt_iterator i = tsi_last (list); | |
479 | for (; !tsi_end_p (i); tsi_prev (&i)) | |
480 | { | |
481 | tree t = tsi_stmt (i); | |
482 | if (t == last) | |
483 | break; | |
484 | if (!check_constexpr_ctor_body_1 (last, t)) | |
485 | { | |
486 | ok = false; | |
487 | break; | |
488 | } | |
489 | } | |
490 | } | |
491 | else if (list != last | |
492 | && !check_constexpr_ctor_body_1 (last, list)) | |
493 | ok = false; | |
494 | if (!ok) | |
495 | { | |
496 | if (complain) | |
84fa214d | 497 | error ("%<constexpr%> constructor does not have empty body"); |
2d76680f PC |
498 | DECL_DECLARED_CONSTEXPR_P (current_function_decl) = false; |
499 | } | |
500 | return ok; | |
501 | } | |
502 | ||
503 | /* V is a vector of constructor elements built up for the base and member | |
504 | initializers of a constructor for TYPE. They need to be in increasing | |
505 | offset order, which they might not be yet if TYPE has a primary base | |
506 | which is not first in the base-clause or a vptr and at least one base | |
507 | all of which are non-primary. */ | |
508 | ||
509 | static vec<constructor_elt, va_gc> * | |
510 | sort_constexpr_mem_initializers (tree type, vec<constructor_elt, va_gc> *v) | |
511 | { | |
512 | tree pri = CLASSTYPE_PRIMARY_BINFO (type); | |
513 | tree field_type; | |
514 | unsigned i; | |
515 | constructor_elt *ce; | |
516 | ||
517 | if (pri) | |
518 | field_type = BINFO_TYPE (pri); | |
519 | else if (TYPE_CONTAINS_VPTR_P (type)) | |
520 | field_type = vtbl_ptr_type_node; | |
521 | else | |
522 | return v; | |
523 | ||
524 | /* Find the element for the primary base or vptr and move it to the | |
525 | beginning of the vec. */ | |
526 | for (i = 0; vec_safe_iterate (v, i, &ce); ++i) | |
527 | if (TREE_TYPE (ce->index) == field_type) | |
528 | break; | |
529 | ||
530 | if (i > 0 && i < vec_safe_length (v)) | |
531 | { | |
532 | vec<constructor_elt, va_gc> &vref = *v; | |
533 | constructor_elt elt = vref[i]; | |
534 | for (; i > 0; --i) | |
535 | vref[i] = vref[i-1]; | |
536 | vref[0] = elt; | |
537 | } | |
538 | ||
539 | return v; | |
540 | } | |
541 | ||
542 | /* Build compile-time evalable representations of member-initializer list | |
543 | for a constexpr constructor. */ | |
544 | ||
545 | static tree | |
546 | build_constexpr_constructor_member_initializers (tree type, tree body) | |
547 | { | |
548 | vec<constructor_elt, va_gc> *vec = NULL; | |
549 | bool ok = true; | |
fa837fb6 JM |
550 | while (true) |
551 | switch (TREE_CODE (body)) | |
552 | { | |
553 | case MUST_NOT_THROW_EXPR: | |
554 | case EH_SPEC_BLOCK: | |
555 | body = TREE_OPERAND (body, 0); | |
556 | break; | |
557 | ||
558 | case STATEMENT_LIST: | |
559 | for (tree_stmt_iterator i = tsi_start (body); | |
560 | !tsi_end_p (i); tsi_next (&i)) | |
561 | { | |
562 | body = tsi_stmt (i); | |
563 | if (TREE_CODE (body) == BIND_EXPR) | |
564 | break; | |
565 | } | |
566 | break; | |
567 | ||
568 | case BIND_EXPR: | |
569 | body = BIND_EXPR_BODY (body); | |
570 | goto found; | |
571 | ||
572 | default: | |
573 | gcc_unreachable (); | |
58cc255c | 574 | } |
fa837fb6 | 575 | found: |
2d76680f PC |
576 | if (TREE_CODE (body) == CLEANUP_POINT_EXPR) |
577 | { | |
578 | body = TREE_OPERAND (body, 0); | |
579 | if (TREE_CODE (body) == EXPR_STMT) | |
580 | body = TREE_OPERAND (body, 0); | |
581 | if (TREE_CODE (body) == INIT_EXPR | |
582 | && (same_type_ignoring_top_level_qualifiers_p | |
583 | (TREE_TYPE (TREE_OPERAND (body, 0)), | |
584 | current_class_type))) | |
585 | { | |
586 | /* Trivial copy. */ | |
587 | return TREE_OPERAND (body, 1); | |
588 | } | |
589 | ok = build_data_member_initialization (body, &vec); | |
590 | } | |
591 | else if (TREE_CODE (body) == STATEMENT_LIST) | |
592 | { | |
593 | tree_stmt_iterator i; | |
594 | for (i = tsi_start (body); !tsi_end_p (i); tsi_next (&i)) | |
595 | { | |
596 | ok = build_data_member_initialization (tsi_stmt (i), &vec); | |
597 | if (!ok) | |
598 | break; | |
599 | } | |
600 | } | |
601 | else if (TREE_CODE (body) == TRY_BLOCK) | |
602 | { | |
603 | error ("body of %<constexpr%> constructor cannot be " | |
604 | "a function-try-block"); | |
605 | return error_mark_node; | |
606 | } | |
607 | else if (EXPR_P (body)) | |
608 | ok = build_data_member_initialization (body, &vec); | |
609 | else | |
610 | gcc_assert (errorcount > 0); | |
611 | if (ok) | |
612 | { | |
613 | if (vec_safe_length (vec) > 0) | |
614 | { | |
615 | /* In a delegating constructor, return the target. */ | |
616 | constructor_elt *ce = &(*vec)[0]; | |
617 | if (ce->index == current_class_ptr) | |
618 | { | |
619 | body = ce->value; | |
620 | vec_free (vec); | |
621 | return body; | |
622 | } | |
623 | } | |
624 | vec = sort_constexpr_mem_initializers (type, vec); | |
625 | return build_constructor (type, vec); | |
626 | } | |
627 | else | |
628 | return error_mark_node; | |
629 | } | |
630 | ||
1b6fa695 ML |
631 | /* We have an expression tree T that represents a call, either CALL_EXPR |
632 | or AGGR_INIT_EXPR. If the call is lexically to a named function, | |
633 | retrun the _DECL for that function. */ | |
634 | ||
635 | static tree | |
636 | get_function_named_in_call (tree t) | |
637 | { | |
638 | tree fun = cp_get_callee (t); | |
639 | if (fun && TREE_CODE (fun) == ADDR_EXPR | |
640 | && TREE_CODE (TREE_OPERAND (fun, 0)) == FUNCTION_DECL) | |
641 | fun = TREE_OPERAND (fun, 0); | |
642 | return fun; | |
643 | } | |
644 | ||
2d76680f PC |
645 | /* Subroutine of register_constexpr_fundef. BODY is the body of a function |
646 | declared to be constexpr, or a sub-statement thereof. Returns the | |
647 | return value if suitable, error_mark_node for a statement not allowed in | |
648 | a constexpr function, or NULL_TREE if no return value was found. */ | |
649 | ||
650 | static tree | |
651 | constexpr_fn_retval (tree body) | |
652 | { | |
653 | switch (TREE_CODE (body)) | |
654 | { | |
655 | case STATEMENT_LIST: | |
656 | { | |
657 | tree_stmt_iterator i; | |
658 | tree expr = NULL_TREE; | |
659 | for (i = tsi_start (body); !tsi_end_p (i); tsi_next (&i)) | |
660 | { | |
661 | tree s = constexpr_fn_retval (tsi_stmt (i)); | |
662 | if (s == error_mark_node) | |
663 | return error_mark_node; | |
664 | else if (s == NULL_TREE) | |
665 | /* Keep iterating. */; | |
666 | else if (expr) | |
667 | /* Multiple return statements. */ | |
668 | return error_mark_node; | |
669 | else | |
670 | expr = s; | |
671 | } | |
672 | return expr; | |
673 | } | |
674 | ||
675 | case RETURN_EXPR: | |
676 | return break_out_target_exprs (TREE_OPERAND (body, 0)); | |
677 | ||
678 | case DECL_EXPR: | |
0162cb3b PC |
679 | { |
680 | tree decl = DECL_EXPR_DECL (body); | |
681 | if (TREE_CODE (decl) == USING_DECL | |
682 | /* Accept __func__, __FUNCTION__, and __PRETTY_FUNCTION__. */ | |
683 | || DECL_ARTIFICIAL (decl)) | |
684 | return NULL_TREE; | |
685 | return error_mark_node; | |
686 | } | |
2d76680f PC |
687 | |
688 | case CLEANUP_POINT_EXPR: | |
689 | return constexpr_fn_retval (TREE_OPERAND (body, 0)); | |
690 | ||
691 | case BIND_EXPR: | |
692 | if (!check_constexpr_bind_expr_vars (body)) | |
693 | return error_mark_node; | |
694 | return constexpr_fn_retval (BIND_EXPR_BODY (body)); | |
695 | ||
696 | case USING_STMT: | |
697 | return NULL_TREE; | |
698 | ||
1b6fa695 ML |
699 | case CALL_EXPR: |
700 | { | |
701 | tree fun = get_function_named_in_call (body); | |
702 | if (fun != NULL_TREE | |
703 | && DECL_FUNCTION_CODE (fun) == BUILT_IN_UNREACHABLE) | |
704 | return NULL_TREE; | |
705 | } | |
706 | /* Fallthru. */ | |
707 | ||
2d76680f PC |
708 | default: |
709 | return error_mark_node; | |
710 | } | |
711 | } | |
712 | ||
713 | /* Subroutine of register_constexpr_fundef. BODY is the DECL_SAVED_TREE of | |
714 | FUN; do the necessary transformations to turn it into a single expression | |
715 | that we can store in the hash table. */ | |
716 | ||
717 | static tree | |
718 | massage_constexpr_body (tree fun, tree body) | |
719 | { | |
720 | if (DECL_CONSTRUCTOR_P (fun)) | |
721 | body = build_constexpr_constructor_member_initializers | |
722 | (DECL_CONTEXT (fun), body); | |
60813a46 | 723 | else if (cxx_dialect < cxx14) |
2d76680f PC |
724 | { |
725 | if (TREE_CODE (body) == EH_SPEC_BLOCK) | |
726 | body = EH_SPEC_STMTS (body); | |
727 | if (TREE_CODE (body) == MUST_NOT_THROW_EXPR) | |
728 | body = TREE_OPERAND (body, 0); | |
729 | body = constexpr_fn_retval (body); | |
730 | } | |
731 | return body; | |
732 | } | |
733 | ||
3e4b91f2 NS |
734 | /* CTYPE is a type constructed from BODY. Return true if some |
735 | bases/fields are uninitialized, and complain if COMPLAIN. */ | |
2d76680f PC |
736 | |
737 | static bool | |
3e4b91f2 | 738 | cx_check_missing_mem_inits (tree ctype, tree body, bool complain) |
2d76680f | 739 | { |
3e4b91f2 NS |
740 | unsigned nelts = 0; |
741 | ||
742 | if (body) | |
743 | { | |
744 | if (TREE_CODE (body) != CONSTRUCTOR) | |
745 | return false; | |
746 | nelts = CONSTRUCTOR_NELTS (body); | |
747 | } | |
748 | tree field = TYPE_FIELDS (ctype); | |
2d76680f PC |
749 | |
750 | if (TREE_CODE (ctype) == UNION_TYPE) | |
751 | { | |
752 | if (nelts == 0 && next_initializable_field (field)) | |
753 | { | |
754 | if (complain) | |
755 | error ("%<constexpr%> constructor for union %qT must " | |
756 | "initialize exactly one non-static data member", ctype); | |
757 | return true; | |
758 | } | |
759 | return false; | |
760 | } | |
761 | ||
3e4b91f2 NS |
762 | /* Iterate over the CONSTRUCTOR, checking any missing fields don't |
763 | need an explicit initialization. */ | |
764 | bool bad = false; | |
765 | for (unsigned i = 0; i <= nelts; ++i) | |
2d76680f | 766 | { |
3e4b91f2 NS |
767 | tree index = NULL_TREE; |
768 | if (i < nelts) | |
2d76680f PC |
769 | { |
770 | index = CONSTRUCTOR_ELT (body, i)->index; | |
771 | /* Skip base and vtable inits. */ | |
772 | if (TREE_CODE (index) != FIELD_DECL | |
773 | || DECL_ARTIFICIAL (index)) | |
774 | continue; | |
775 | } | |
3e4b91f2 | 776 | |
2d76680f PC |
777 | for (; field != index; field = DECL_CHAIN (field)) |
778 | { | |
779 | tree ftype; | |
3e4b91f2 NS |
780 | if (TREE_CODE (field) != FIELD_DECL) |
781 | continue; | |
782 | if (DECL_C_BIT_FIELD (field) && !DECL_NAME (field)) | |
2d76680f | 783 | continue; |
3e4b91f2 NS |
784 | if (DECL_ARTIFICIAL (field)) |
785 | continue; | |
786 | if (ANON_AGGR_TYPE_P (TREE_TYPE (field))) | |
787 | { | |
788 | /* Recurse to check the anonummous aggregate member. */ | |
789 | bad |= cx_check_missing_mem_inits | |
790 | (TREE_TYPE (field), NULL_TREE, complain); | |
791 | if (bad && !complain) | |
792 | return true; | |
793 | continue; | |
794 | } | |
2d76680f PC |
795 | ftype = strip_array_types (TREE_TYPE (field)); |
796 | if (type_has_constexpr_default_constructor (ftype)) | |
797 | { | |
798 | /* It's OK to skip a member with a trivial constexpr ctor. | |
799 | A constexpr ctor that isn't trivial should have been | |
800 | added in by now. */ | |
801 | gcc_checking_assert (!TYPE_HAS_COMPLEX_DFLT (ftype) | |
802 | || errorcount != 0); | |
803 | continue; | |
804 | } | |
805 | if (!complain) | |
806 | return true; | |
b8cd3996 JM |
807 | error ("member %qD must be initialized by mem-initializer " |
808 | "in %<constexpr%> constructor", field); | |
809 | inform (DECL_SOURCE_LOCATION (field), "declared here"); | |
2d76680f PC |
810 | bad = true; |
811 | } | |
812 | if (field == NULL_TREE) | |
813 | break; | |
3e4b91f2 NS |
814 | |
815 | if (ANON_AGGR_TYPE_P (TREE_TYPE (index))) | |
816 | { | |
817 | /* Check the anonymous aggregate initializer is valid. */ | |
818 | bad |= cx_check_missing_mem_inits | |
819 | (TREE_TYPE (index), CONSTRUCTOR_ELT (body, i)->value, complain); | |
820 | if (bad && !complain) | |
821 | return true; | |
822 | } | |
2d76680f PC |
823 | field = DECL_CHAIN (field); |
824 | } | |
825 | ||
826 | return bad; | |
827 | } | |
828 | ||
829 | /* We are processing the definition of the constexpr function FUN. | |
830 | Check that its BODY fulfills the propriate requirements and | |
831 | enter it in the constexpr function definition table. | |
832 | For constructor BODY is actually the TREE_LIST of the | |
833 | member-initializer list. */ | |
834 | ||
835 | tree | |
836 | register_constexpr_fundef (tree fun, tree body) | |
837 | { | |
838 | constexpr_fundef entry; | |
839 | constexpr_fundef **slot; | |
840 | ||
841 | if (!is_valid_constexpr_fn (fun, !DECL_GENERATED_P (fun))) | |
842 | return NULL; | |
843 | ||
ca30abcd JM |
844 | tree massaged = massage_constexpr_body (fun, body); |
845 | if (massaged == NULL_TREE || massaged == error_mark_node) | |
2d76680f PC |
846 | { |
847 | if (!DECL_CONSTRUCTOR_P (fun)) | |
84fa214d ML |
848 | error ("body of %<constexpr%> function %qD not a return-statement", |
849 | fun); | |
2d76680f PC |
850 | return NULL; |
851 | } | |
852 | ||
ca30abcd | 853 | if (!potential_rvalue_constant_expression (massaged)) |
2d76680f PC |
854 | { |
855 | if (!DECL_GENERATED_P (fun)) | |
ca30abcd | 856 | require_potential_rvalue_constant_expression (massaged); |
2d76680f PC |
857 | return NULL; |
858 | } | |
859 | ||
860 | if (DECL_CONSTRUCTOR_P (fun) | |
3e4b91f2 NS |
861 | && cx_check_missing_mem_inits (DECL_CONTEXT (fun), |
862 | massaged, !DECL_GENERATED_P (fun))) | |
2d76680f PC |
863 | return NULL; |
864 | ||
865 | /* Create the constexpr function table if necessary. */ | |
866 | if (constexpr_fundef_table == NULL) | |
867 | constexpr_fundef_table | |
868 | = hash_table<constexpr_fundef_hasher>::create_ggc (101); | |
869 | ||
870 | entry.decl = fun; | |
871 | entry.body = body; | |
872 | slot = constexpr_fundef_table->find_slot (&entry, INSERT); | |
873 | ||
874 | gcc_assert (*slot == NULL); | |
875 | *slot = ggc_alloc<constexpr_fundef> (); | |
876 | **slot = entry; | |
877 | ||
878 | return fun; | |
879 | } | |
880 | ||
881 | /* FUN is a non-constexpr function called in a context that requires a | |
882 | constant expression. If it comes from a constexpr template, explain why | |
883 | the instantiation isn't constexpr. */ | |
884 | ||
885 | void | |
886 | explain_invalid_constexpr_fn (tree fun) | |
887 | { | |
888 | static hash_set<tree> *diagnosed; | |
889 | tree body; | |
890 | location_t save_loc; | |
98e5a19a | 891 | /* Only diagnose defaulted functions, lambdas, or instantiations. */ |
2d76680f | 892 | if (!DECL_DEFAULTED_FN (fun) |
98e5a19a | 893 | && !LAMBDA_TYPE_P (CP_DECL_CONTEXT (fun)) |
2d76680f PC |
894 | && !is_instantiation_of_constexpr (fun)) |
895 | return; | |
896 | if (diagnosed == NULL) | |
897 | diagnosed = new hash_set<tree>; | |
898 | if (diagnosed->add (fun)) | |
899 | /* Already explained. */ | |
900 | return; | |
901 | ||
902 | save_loc = input_location; | |
98e5a19a JM |
903 | if (!lambda_static_thunk_p (fun)) |
904 | { | |
905 | /* Diagnostics should completely ignore the static thunk, so leave | |
906 | input_location set to our caller's location. */ | |
907 | input_location = DECL_SOURCE_LOCATION (fun); | |
908 | inform (input_location, | |
84fa214d | 909 | "%qD is not usable as a %<constexpr%> function because:", fun); |
98e5a19a | 910 | } |
2d76680f PC |
911 | /* First check the declaration. */ |
912 | if (is_valid_constexpr_fn (fun, true)) | |
913 | { | |
914 | /* Then if it's OK, the body. */ | |
98e5a19a JM |
915 | if (!DECL_DECLARED_CONSTEXPR_P (fun) |
916 | && !LAMBDA_TYPE_P (CP_DECL_CONTEXT (fun))) | |
2d76680f PC |
917 | explain_implicit_non_constexpr (fun); |
918 | else | |
919 | { | |
920 | body = massage_constexpr_body (fun, DECL_SAVED_TREE (fun)); | |
921 | require_potential_rvalue_constant_expression (body); | |
922 | if (DECL_CONSTRUCTOR_P (fun)) | |
3e4b91f2 | 923 | cx_check_missing_mem_inits (DECL_CONTEXT (fun), body, true); |
2d76680f PC |
924 | } |
925 | } | |
926 | input_location = save_loc; | |
927 | } | |
928 | ||
929 | /* Objects of this type represent calls to constexpr functions | |
930 | along with the bindings of parameters to their arguments, for | |
931 | the purpose of compile time evaluation. */ | |
932 | ||
933 | struct GTY((for_user)) constexpr_call { | |
934 | /* Description of the constexpr function definition. */ | |
935 | constexpr_fundef *fundef; | |
936 | /* Parameter bindings environment. A TREE_LIST where each TREE_PURPOSE | |
937 | is a parameter _DECL and the TREE_VALUE is the value of the parameter. | |
938 | Note: This arrangement is made to accommodate the use of | |
939 | iterative_hash_template_arg (see pt.c). If you change this | |
940 | representation, also change the hash calculation in | |
941 | cxx_eval_call_expression. */ | |
942 | tree bindings; | |
943 | /* Result of the call. | |
944 | NULL means the call is being evaluated. | |
945 | error_mark_node means that the evaluation was erroneous; | |
946 | otherwise, the actuall value of the call. */ | |
947 | tree result; | |
948 | /* The hash of this call; we remember it here to avoid having to | |
949 | recalculate it when expanding the hash table. */ | |
950 | hashval_t hash; | |
951 | }; | |
952 | ||
ca752f39 | 953 | struct constexpr_call_hasher : ggc_ptr_hash<constexpr_call> |
2d76680f PC |
954 | { |
955 | static hashval_t hash (constexpr_call *); | |
956 | static bool equal (constexpr_call *, constexpr_call *); | |
3e605b20 JM |
957 | }; |
958 | ||
4b390698 JJ |
959 | enum constexpr_switch_state { |
960 | /* Used when processing a switch for the first time by cxx_eval_switch_expr | |
961 | and default: label for that switch has not been seen yet. */ | |
962 | css_default_not_seen, | |
963 | /* Used when processing a switch for the first time by cxx_eval_switch_expr | |
964 | and default: label for that switch has been seen already. */ | |
965 | css_default_seen, | |
966 | /* Used when processing a switch for the second time by | |
967 | cxx_eval_switch_expr, where default: label should match. */ | |
968 | css_default_processing | |
969 | }; | |
970 | ||
3e605b20 JM |
971 | /* The constexpr expansion context. CALL is the current function |
972 | expansion, CTOR is the current aggregate initializer, OBJECT is the | |
973 | object being initialized by CTOR, either a VAR_DECL or a _REF. VALUES | |
974 | is a map of values of variables initialized within the expression. */ | |
975 | ||
976 | struct constexpr_ctx { | |
13f649f6 | 977 | /* The innermost call we're evaluating. */ |
3e605b20 | 978 | constexpr_call *call; |
13f649f6 JM |
979 | /* Values for any temporaries or local variables within the |
980 | constant-expression. */ | |
3e605b20 | 981 | hash_map<tree,tree> *values; |
39dce2b7 JM |
982 | /* SAVE_EXPRs that we've seen within the current LOOP_EXPR. NULL if we |
983 | aren't inside a loop. */ | |
984 | hash_set<tree> *save_exprs; | |
13f649f6 JM |
985 | /* The CONSTRUCTOR we're currently building up for an aggregate |
986 | initializer. */ | |
3e605b20 | 987 | tree ctor; |
13f649f6 | 988 | /* The object we're building the CONSTRUCTOR for. */ |
3e605b20 | 989 | tree object; |
4b390698 JJ |
990 | /* If inside SWITCH_EXPR. */ |
991 | constexpr_switch_state *css_state; | |
13f649f6 | 992 | /* Whether we should error on a non-constant expression or fail quietly. */ |
2b3ab879 | 993 | bool quiet; |
13f649f6 JM |
994 | /* Whether we are strictly conforming to constant expression rules or |
995 | trying harder to get a constant value. */ | |
69eb4fde | 996 | bool strict; |
3e605b20 | 997 | }; |
2d76680f PC |
998 | |
999 | /* A table of all constexpr calls that have been evaluated by the | |
1000 | compiler in this translation unit. */ | |
1001 | ||
97f3003f | 1002 | static GTY (()) hash_table<constexpr_call_hasher> *constexpr_call_table; |
2d76680f | 1003 | |
3e605b20 | 1004 | static tree cxx_eval_constant_expression (const constexpr_ctx *, tree, |
5a804683 | 1005 | bool, bool *, bool *, tree * = NULL); |
2d76680f PC |
1006 | |
1007 | /* Compute a hash value for a constexpr call representation. */ | |
1008 | ||
1009 | inline hashval_t | |
1010 | constexpr_call_hasher::hash (constexpr_call *info) | |
1011 | { | |
1012 | return info->hash; | |
1013 | } | |
1014 | ||
1015 | /* Return true if the objects pointed to by P and Q represent calls | |
1016 | to the same constexpr function with the same arguments. | |
1017 | Otherwise, return false. */ | |
1018 | ||
1019 | bool | |
1020 | constexpr_call_hasher::equal (constexpr_call *lhs, constexpr_call *rhs) | |
1021 | { | |
1022 | tree lhs_bindings; | |
1023 | tree rhs_bindings; | |
1024 | if (lhs == rhs) | |
1025 | return 1; | |
1026 | if (!constexpr_fundef_hasher::equal (lhs->fundef, rhs->fundef)) | |
1027 | return 0; | |
1028 | lhs_bindings = lhs->bindings; | |
1029 | rhs_bindings = rhs->bindings; | |
1030 | while (lhs_bindings != NULL && rhs_bindings != NULL) | |
1031 | { | |
1032 | tree lhs_arg = TREE_VALUE (lhs_bindings); | |
1033 | tree rhs_arg = TREE_VALUE (rhs_bindings); | |
1034 | gcc_assert (TREE_TYPE (lhs_arg) == TREE_TYPE (rhs_arg)); | |
1035 | if (!cp_tree_equal (lhs_arg, rhs_arg)) | |
1036 | return 0; | |
1037 | lhs_bindings = TREE_CHAIN (lhs_bindings); | |
1038 | rhs_bindings = TREE_CHAIN (rhs_bindings); | |
1039 | } | |
1040 | return lhs_bindings == rhs_bindings; | |
1041 | } | |
1042 | ||
1043 | /* Initialize the constexpr call table, if needed. */ | |
1044 | ||
1045 | static void | |
1046 | maybe_initialize_constexpr_call_table (void) | |
1047 | { | |
1048 | if (constexpr_call_table == NULL) | |
1049 | constexpr_call_table = hash_table<constexpr_call_hasher>::create_ggc (101); | |
1050 | } | |
1051 | ||
c0daf32d PP |
1052 | /* During constexpr CALL_EXPR evaluation, to avoid issues with sharing when |
1053 | a function happens to get called recursively, we unshare the callee | |
1054 | function's body and evaluate this unshared copy instead of evaluating the | |
1055 | original body. | |
1056 | ||
1057 | FUNDEF_COPIES_TABLE is a per-function freelist of these unshared function | |
1058 | copies. The underlying data structure of FUNDEF_COPIES_TABLE is a hash_map | |
97f3003f JM |
1059 | that's keyed off of the original FUNCTION_DECL and whose value is a |
1060 | TREE_LIST of this function's unused copies awaiting reuse. | |
c0daf32d | 1061 | |
97f3003f | 1062 | This is not GC-deletable to avoid GC affecting UID generation. */ |
c0daf32d | 1063 | |
97f3003f | 1064 | static GTY(()) hash_map<tree, tree> *fundef_copies_table; |
c0daf32d PP |
1065 | |
1066 | /* Initialize FUNDEF_COPIES_TABLE if it's not initialized. */ | |
1067 | ||
1068 | static void | |
1069 | maybe_initialize_fundef_copies_table () | |
1070 | { | |
97f3003f JM |
1071 | if (fundef_copies_table == NULL) |
1072 | fundef_copies_table = hash_map<tree,tree>::create_ggc (101); | |
c0daf32d PP |
1073 | } |
1074 | ||
1075 | /* Reuse a copy or create a new unshared copy of the function FUN. | |
3c98ff9b NS |
1076 | Return this copy. We use a TREE_LIST whose PURPOSE is body, VALUE |
1077 | is parms, TYPE is result. */ | |
c0daf32d | 1078 | |
97f3003f | 1079 | static tree |
c0daf32d PP |
1080 | get_fundef_copy (tree fun) |
1081 | { | |
1082 | maybe_initialize_fundef_copies_table (); | |
1083 | ||
97f3003f | 1084 | tree copy; |
3c98ff9b NS |
1085 | bool existed; |
1086 | tree *slot = &fundef_copies_table->get_or_insert (fun, &existed); | |
1087 | ||
1088 | if (!existed) | |
c0daf32d | 1089 | { |
3c98ff9b NS |
1090 | /* There is no cached function available, or in use. We can use |
1091 | the function directly. That the slot is now created records | |
1092 | that this function is now in use. */ | |
1093 | copy = build_tree_list (DECL_SAVED_TREE (fun), DECL_ARGUMENTS (fun)); | |
1094 | TREE_TYPE (copy) = DECL_RESULT (fun); | |
1095 | } | |
1096 | else if (*slot == NULL_TREE) | |
1097 | { | |
1098 | /* We've already used the function itself, so make a copy. */ | |
97f3003f | 1099 | copy = build_tree_list (NULL, NULL); |
97f3003f | 1100 | TREE_PURPOSE (copy) = copy_fn (fun, TREE_VALUE (copy), TREE_TYPE (copy)); |
c0daf32d PP |
1101 | } |
1102 | else | |
1103 | { | |
3c98ff9b | 1104 | /* We have a cached function available. */ |
c0daf32d | 1105 | copy = *slot; |
97f3003f | 1106 | *slot = TREE_CHAIN (copy); |
c0daf32d PP |
1107 | } |
1108 | ||
1109 | return copy; | |
1110 | } | |
1111 | ||
3c98ff9b NS |
1112 | /* Save the copy COPY of function FUN for later reuse by |
1113 | get_fundef_copy(). By construction, there will always be an entry | |
1114 | to find. */ | |
c0daf32d PP |
1115 | |
1116 | static void | |
97f3003f | 1117 | save_fundef_copy (tree fun, tree copy) |
c0daf32d | 1118 | { |
3c98ff9b | 1119 | tree *slot = fundef_copies_table->get (fun); |
97f3003f | 1120 | TREE_CHAIN (copy) = *slot; |
c0daf32d PP |
1121 | *slot = copy; |
1122 | } | |
1123 | ||
2d76680f PC |
1124 | /* We have an expression tree T that represents a call, either CALL_EXPR |
1125 | or AGGR_INIT_EXPR. Return the Nth argument. */ | |
1126 | ||
1127 | static inline tree | |
1128 | get_nth_callarg (tree t, int n) | |
1129 | { | |
1130 | switch (TREE_CODE (t)) | |
1131 | { | |
1132 | case CALL_EXPR: | |
1133 | return CALL_EXPR_ARG (t, n); | |
1134 | ||
1135 | case AGGR_INIT_EXPR: | |
1136 | return AGGR_INIT_EXPR_ARG (t, n); | |
1137 | ||
1138 | default: | |
1139 | gcc_unreachable (); | |
1140 | return NULL; | |
1141 | } | |
1142 | } | |
1143 | ||
2d76680f PC |
1144 | /* Attempt to evaluate T which represents a call to a builtin function. |
1145 | We assume here that all builtin functions evaluate to scalar types | |
1146 | represented by _CST nodes. */ | |
1147 | ||
1148 | static tree | |
5756d0f9 | 1149 | cxx_eval_builtin_function_call (const constexpr_ctx *ctx, tree t, tree fun, |
92a596e8 | 1150 | bool lval, |
2d76680f PC |
1151 | bool *non_constant_p, bool *overflow_p) |
1152 | { | |
1153 | const int nargs = call_expr_nargs (t); | |
1154 | tree *args = (tree *) alloca (nargs * sizeof (tree)); | |
1155 | tree new_call; | |
1156 | int i; | |
5756d0f9 JM |
1157 | |
1158 | /* Don't fold __builtin_constant_p within a constexpr function. */ | |
b925d25d JM |
1159 | bool bi_const_p = (DECL_FUNCTION_CODE (fun) == BUILT_IN_CONSTANT_P); |
1160 | ||
1161 | if (bi_const_p | |
5756d0f9 JM |
1162 | && current_function_decl |
1163 | && DECL_DECLARED_CONSTEXPR_P (current_function_decl)) | |
2d76680f | 1164 | { |
5756d0f9 JM |
1165 | *non_constant_p = true; |
1166 | return t; | |
2d76680f | 1167 | } |
5756d0f9 JM |
1168 | |
1169 | /* Be permissive for arguments to built-ins; __builtin_constant_p should | |
1170 | return constant false for a non-constant argument. */ | |
1171 | constexpr_ctx new_ctx = *ctx; | |
1172 | new_ctx.quiet = true; | |
1173 | bool dummy1 = false, dummy2 = false; | |
1174 | for (i = 0; i < nargs; ++i) | |
b925d25d JM |
1175 | { |
1176 | args[i] = cxx_eval_constant_expression (&new_ctx, CALL_EXPR_ARG (t, i), | |
109d2197 | 1177 | false, &dummy1, &dummy2); |
b925d25d JM |
1178 | if (bi_const_p) |
1179 | /* For __built_in_constant_p, fold all expressions with constant values | |
1180 | even if they aren't C++ constant-expressions. */ | |
1181 | args[i] = cp_fully_fold (args[i]); | |
1182 | } | |
5756d0f9 JM |
1183 | |
1184 | bool save_ffbcp = force_folding_builtin_constant_p; | |
1185 | force_folding_builtin_constant_p = true; | |
109d2197 JJ |
1186 | new_call = fold_builtin_call_array (EXPR_LOCATION (t), TREE_TYPE (t), |
1187 | CALL_EXPR_FN (t), nargs, args); | |
5756d0f9 | 1188 | force_folding_builtin_constant_p = save_ffbcp; |
109d2197 JJ |
1189 | if (new_call == NULL) |
1190 | { | |
1191 | if (!*non_constant_p && !ctx->quiet) | |
1192 | { | |
1b6fa695 ML |
1193 | /* Do not allow__builtin_unreachable in constexpr function. |
1194 | The __builtin_unreachable call with BUILTINS_LOCATION | |
1195 | comes from cp_maybe_instrument_return. */ | |
1196 | if (DECL_FUNCTION_CODE (fun) == BUILT_IN_UNREACHABLE | |
1197 | && EXPR_LOCATION (t) == BUILTINS_LOCATION) | |
84fa214d | 1198 | error ("%<constexpr%> call flows off the end of the function"); |
1b6fa695 ML |
1199 | else |
1200 | { | |
1201 | new_call = build_call_array_loc (EXPR_LOCATION (t), TREE_TYPE (t), | |
1202 | CALL_EXPR_FN (t), nargs, args); | |
1203 | error ("%q+E is not a constant expression", new_call); | |
1204 | } | |
109d2197 JJ |
1205 | } |
1206 | *non_constant_p = true; | |
1207 | return t; | |
1208 | } | |
1209 | ||
a0ab7ccd | 1210 | if (!is_constant_expression (new_call)) |
109d2197 JJ |
1211 | { |
1212 | if (!*non_constant_p && !ctx->quiet) | |
1213 | error ("%q+E is not a constant expression", new_call); | |
1214 | *non_constant_p = true; | |
1215 | return t; | |
1216 | } | |
1217 | ||
1218 | return cxx_eval_constant_expression (&new_ctx, new_call, lval, | |
1219 | non_constant_p, overflow_p); | |
2d76680f PC |
1220 | } |
1221 | ||
1222 | /* TEMP is the constant value of a temporary object of type TYPE. Adjust | |
1223 | the type of the value to match. */ | |
1224 | ||
1225 | static tree | |
1226 | adjust_temp_type (tree type, tree temp) | |
1227 | { | |
1228 | if (TREE_TYPE (temp) == type) | |
1229 | return temp; | |
1230 | /* Avoid wrapping an aggregate value in a NOP_EXPR. */ | |
1231 | if (TREE_CODE (temp) == CONSTRUCTOR) | |
1232 | return build_constructor (type, CONSTRUCTOR_ELTS (temp)); | |
1233 | gcc_assert (scalarish_type_p (type)); | |
1234 | return cp_fold_convert (type, temp); | |
1235 | } | |
1236 | ||
0146e25f PP |
1237 | /* Callback for walk_tree used by unshare_constructor. */ |
1238 | ||
1239 | static tree | |
1240 | find_constructor (tree *tp, int *walk_subtrees, void *) | |
1241 | { | |
1242 | if (TYPE_P (*tp)) | |
1243 | *walk_subtrees = 0; | |
1244 | if (TREE_CODE (*tp) == CONSTRUCTOR) | |
1245 | return *tp; | |
1246 | return NULL_TREE; | |
1247 | } | |
1248 | ||
1249 | /* If T is a CONSTRUCTOR or an expression that has a CONSTRUCTOR node as a | |
1250 | subexpression, return an unshared copy of T. Otherwise return T. */ | |
1251 | ||
1252 | static tree | |
1253 | unshare_constructor (tree t) | |
1254 | { | |
1255 | tree ctor = walk_tree (&t, find_constructor, NULL, NULL); | |
1256 | if (ctor != NULL_TREE) | |
1257 | return unshare_expr (t); | |
1258 | return t; | |
1259 | } | |
1260 | ||
2d76680f PC |
1261 | /* Subroutine of cxx_eval_call_expression. |
1262 | We are processing a call expression (either CALL_EXPR or | |
3e605b20 | 1263 | AGGR_INIT_EXPR) in the context of CTX. Evaluate |
2d76680f PC |
1264 | all arguments and bind their values to correspondings |
1265 | parameters, making up the NEW_CALL context. */ | |
1266 | ||
1267 | static void | |
3e605b20 | 1268 | cxx_bind_parameters_in_call (const constexpr_ctx *ctx, tree t, |
2d76680f | 1269 | constexpr_call *new_call, |
12d9ce19 JM |
1270 | bool *non_constant_p, bool *overflow_p, |
1271 | bool *non_constant_args) | |
2d76680f PC |
1272 | { |
1273 | const int nargs = call_expr_nargs (t); | |
1274 | tree fun = new_call->fundef->decl; | |
1275 | tree parms = DECL_ARGUMENTS (fun); | |
1276 | int i; | |
60813a46 | 1277 | tree *p = &new_call->bindings; |
2d76680f PC |
1278 | for (i = 0; i < nargs; ++i) |
1279 | { | |
1280 | tree x, arg; | |
1281 | tree type = parms ? TREE_TYPE (parms) : void_type_node; | |
2d76680f | 1282 | x = get_nth_callarg (t, i); |
3e605b20 JM |
1283 | /* For member function, the first argument is a pointer to the implied |
1284 | object. For a constructor, it might still be a dummy object, in | |
60813a46 | 1285 | which case we get the real argument from ctx. */ |
3e605b20 JM |
1286 | if (i == 0 && DECL_CONSTRUCTOR_P (fun) |
1287 | && is_dummy_object (x)) | |
1288 | { | |
1289 | x = ctx->object; | |
84dd815f | 1290 | x = build_address (x); |
3e605b20 | 1291 | } |
92a596e8 | 1292 | bool lval = false; |
92a596e8 | 1293 | arg = cxx_eval_constant_expression (ctx, x, lval, |
5a804683 | 1294 | non_constant_p, overflow_p); |
2d76680f | 1295 | /* Don't VERIFY_CONSTANT here. */ |
2b3ab879 | 1296 | if (*non_constant_p && ctx->quiet) |
2d76680f PC |
1297 | return; |
1298 | /* Just discard ellipsis args after checking their constantitude. */ | |
1299 | if (!parms) | |
1300 | continue; | |
4727d4c6 NS |
1301 | |
1302 | if (!*non_constant_p) | |
1303 | { | |
1304 | /* Make sure the binding has the same type as the parm. But | |
1305 | only for constant args. */ | |
1306 | if (TREE_CODE (type) != REFERENCE_TYPE) | |
1307 | arg = adjust_temp_type (type, arg); | |
1308 | if (!TREE_CONSTANT (arg)) | |
1309 | *non_constant_args = true; | |
1310 | *p = build_tree_list (parms, arg); | |
1311 | p = &TREE_CHAIN (*p); | |
1312 | } | |
2d76680f PC |
1313 | parms = TREE_CHAIN (parms); |
1314 | } | |
1315 | } | |
1316 | ||
1317 | /* Variables and functions to manage constexpr call expansion context. | |
1318 | These do not need to be marked for PCH or GC. */ | |
1319 | ||
1320 | /* FIXME remember and print actual constant arguments. */ | |
7de76362 | 1321 | static vec<tree> call_stack; |
2d76680f PC |
1322 | static int call_stack_tick; |
1323 | static int last_cx_error_tick; | |
1324 | ||
1325 | static bool | |
1326 | push_cx_call_context (tree call) | |
1327 | { | |
1328 | ++call_stack_tick; | |
1329 | if (!EXPR_HAS_LOCATION (call)) | |
1330 | SET_EXPR_LOCATION (call, input_location); | |
1331 | call_stack.safe_push (call); | |
1332 | if (call_stack.length () > (unsigned) max_constexpr_depth) | |
1333 | return false; | |
1334 | return true; | |
1335 | } | |
1336 | ||
1337 | static void | |
1338 | pop_cx_call_context (void) | |
1339 | { | |
1340 | ++call_stack_tick; | |
1341 | call_stack.pop (); | |
1342 | } | |
1343 | ||
1344 | vec<tree> | |
1345 | cx_error_context (void) | |
1346 | { | |
1347 | vec<tree> r = vNULL; | |
1348 | if (call_stack_tick != last_cx_error_tick | |
1349 | && !call_stack.is_empty ()) | |
1350 | r = call_stack; | |
1351 | last_cx_error_tick = call_stack_tick; | |
1352 | return r; | |
1353 | } | |
1354 | ||
44a845ca MS |
1355 | /* Evaluate a call T to a GCC internal function when possible and return |
1356 | the evaluated result or, under the control of CTX, give an error, set | |
1357 | NON_CONSTANT_P, and return the unevaluated call T otherwise. */ | |
1358 | ||
1359 | static tree | |
1360 | cxx_eval_internal_function (const constexpr_ctx *ctx, tree t, | |
1361 | bool lval, | |
1362 | bool *non_constant_p, bool *overflow_p) | |
1363 | { | |
1364 | enum tree_code opcode = ERROR_MARK; | |
1365 | ||
1366 | switch (CALL_EXPR_IFN (t)) | |
1367 | { | |
1368 | case IFN_UBSAN_NULL: | |
1369 | case IFN_UBSAN_BOUNDS: | |
1370 | case IFN_UBSAN_VPTR: | |
81fea426 | 1371 | case IFN_FALLTHROUGH: |
44a845ca MS |
1372 | return void_node; |
1373 | ||
1374 | case IFN_ADD_OVERFLOW: | |
1375 | opcode = PLUS_EXPR; | |
1376 | break; | |
1377 | case IFN_SUB_OVERFLOW: | |
1378 | opcode = MINUS_EXPR; | |
1379 | break; | |
1380 | case IFN_MUL_OVERFLOW: | |
1381 | opcode = MULT_EXPR; | |
1382 | break; | |
1383 | ||
e16f1cc7 JJ |
1384 | case IFN_LAUNDER: |
1385 | return cxx_eval_constant_expression (ctx, CALL_EXPR_ARG (t, 0), | |
1386 | false, non_constant_p, overflow_p); | |
1387 | ||
44a845ca MS |
1388 | default: |
1389 | if (!ctx->quiet) | |
1390 | error_at (EXPR_LOC_OR_LOC (t, input_location), | |
1391 | "call to internal function %qE", t); | |
1392 | *non_constant_p = true; | |
1393 | return t; | |
1394 | } | |
1395 | ||
1396 | /* Evaluate constant arguments using OPCODE and return a complex | |
1397 | number containing the result and the overflow bit. */ | |
1398 | tree arg0 = cxx_eval_constant_expression (ctx, CALL_EXPR_ARG (t, 0), lval, | |
1399 | non_constant_p, overflow_p); | |
1400 | tree arg1 = cxx_eval_constant_expression (ctx, CALL_EXPR_ARG (t, 1), lval, | |
1401 | non_constant_p, overflow_p); | |
1402 | ||
1403 | if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST) | |
1404 | { | |
1405 | location_t loc = EXPR_LOC_OR_LOC (t, input_location); | |
1406 | tree type = TREE_TYPE (TREE_TYPE (t)); | |
1407 | tree result = fold_binary_loc (loc, opcode, type, | |
1408 | fold_convert_loc (loc, type, arg0), | |
1409 | fold_convert_loc (loc, type, arg1)); | |
1410 | tree ovf | |
1411 | = build_int_cst (type, arith_overflowed_p (opcode, type, arg0, arg1)); | |
1412 | /* Reset TREE_OVERFLOW to avoid warnings for the overflow. */ | |
1413 | if (TREE_OVERFLOW (result)) | |
1414 | TREE_OVERFLOW (result) = 0; | |
1415 | ||
1416 | return build_complex (TREE_TYPE (t), result, ovf); | |
1417 | } | |
1418 | ||
1419 | *non_constant_p = true; | |
1420 | return t; | |
1421 | } | |
1422 | ||
ecc57615 JM |
1423 | /* Clean CONSTRUCTOR_NO_IMPLICIT_ZERO from CTOR and its sub-aggregates. */ |
1424 | ||
1425 | static void | |
1426 | clear_no_implicit_zero (tree ctor) | |
1427 | { | |
1428 | if (CONSTRUCTOR_NO_IMPLICIT_ZERO (ctor)) | |
1429 | { | |
1430 | CONSTRUCTOR_NO_IMPLICIT_ZERO (ctor) = false; | |
1431 | tree elt; unsigned HOST_WIDE_INT idx; | |
1432 | FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), idx, elt) | |
1433 | if (TREE_CODE (elt) == CONSTRUCTOR) | |
1434 | clear_no_implicit_zero (elt); | |
1435 | } | |
1436 | } | |
1437 | ||
2d76680f PC |
1438 | /* Subroutine of cxx_eval_constant_expression. |
1439 | Evaluate the call expression tree T in the context of OLD_CALL expression | |
1440 | evaluation. */ | |
1441 | ||
1442 | static tree | |
3e605b20 | 1443 | cxx_eval_call_expression (const constexpr_ctx *ctx, tree t, |
92a596e8 | 1444 | bool lval, |
2d76680f PC |
1445 | bool *non_constant_p, bool *overflow_p) |
1446 | { | |
1447 | location_t loc = EXPR_LOC_OR_LOC (t, input_location); | |
1448 | tree fun = get_function_named_in_call (t); | |
2d76680f | 1449 | constexpr_call new_call = { NULL, NULL, NULL, 0 }; |
2d76680f PC |
1450 | bool depth_ok; |
1451 | ||
0b274c17 | 1452 | if (fun == NULL_TREE) |
44a845ca MS |
1453 | return cxx_eval_internal_function (ctx, t, lval, |
1454 | non_constant_p, overflow_p); | |
0b274c17 | 1455 | |
2d76680f PC |
1456 | if (TREE_CODE (fun) != FUNCTION_DECL) |
1457 | { | |
1458 | /* Might be a constexpr function pointer. */ | |
2b3ab879 | 1459 | fun = cxx_eval_constant_expression (ctx, fun, |
92a596e8 | 1460 | /*lval*/false, non_constant_p, |
5a804683 | 1461 | overflow_p); |
2d76680f PC |
1462 | STRIP_NOPS (fun); |
1463 | if (TREE_CODE (fun) == ADDR_EXPR) | |
1464 | fun = TREE_OPERAND (fun, 0); | |
1465 | } | |
1466 | if (TREE_CODE (fun) != FUNCTION_DECL) | |
1467 | { | |
2b3ab879 | 1468 | if (!ctx->quiet && !*non_constant_p) |
84fa214d | 1469 | error_at (loc, "expression %qE does not designate a %<constexpr%> " |
2d76680f PC |
1470 | "function", fun); |
1471 | *non_constant_p = true; | |
1472 | return t; | |
1473 | } | |
1474 | if (DECL_CLONED_FUNCTION_P (fun)) | |
1475 | fun = DECL_CLONED_FUNCTION (fun); | |
0b274c17 MP |
1476 | |
1477 | if (is_ubsan_builtin_p (fun)) | |
1478 | return void_node; | |
1479 | ||
2d76680f | 1480 | if (is_builtin_fn (fun)) |
5756d0f9 | 1481 | return cxx_eval_builtin_function_call (ctx, t, fun, |
92a596e8 | 1482 | lval, non_constant_p, overflow_p); |
2d76680f PC |
1483 | if (!DECL_DECLARED_CONSTEXPR_P (fun)) |
1484 | { | |
2b3ab879 | 1485 | if (!ctx->quiet) |
2d76680f | 1486 | { |
11399477 | 1487 | if (!lambda_static_thunk_p (fun)) |
84fa214d | 1488 | error_at (loc, "call to non-%<constexpr%> function %qD", fun); |
2d76680f PC |
1489 | explain_invalid_constexpr_fn (fun); |
1490 | } | |
1491 | *non_constant_p = true; | |
1492 | return t; | |
1493 | } | |
1494 | ||
86461cad JM |
1495 | constexpr_ctx new_ctx = *ctx; |
1496 | if (DECL_CONSTRUCTOR_P (fun) && !ctx->object | |
1497 | && TREE_CODE (t) == AGGR_INIT_EXPR) | |
1498 | { | |
1499 | /* We want to have an initialization target for an AGGR_INIT_EXPR. | |
1500 | If we don't already have one in CTX, use the AGGR_INIT_EXPR_SLOT. */ | |
1501 | new_ctx.object = AGGR_INIT_EXPR_SLOT (t); | |
1502 | tree ctor = new_ctx.ctor = build_constructor (DECL_CONTEXT (fun), NULL); | |
1503 | CONSTRUCTOR_NO_IMPLICIT_ZERO (ctor) = true; | |
1504 | ctx->values->put (new_ctx.object, ctor); | |
1505 | ctx = &new_ctx; | |
1506 | } | |
1507 | ||
2d76680f PC |
1508 | /* Shortcut trivial constructor/op=. */ |
1509 | if (trivial_fn_p (fun)) | |
1510 | { | |
86461cad | 1511 | tree init = NULL_TREE; |
2d76680f | 1512 | if (call_expr_nargs (t) == 2) |
86461cad | 1513 | init = convert_from_reference (get_nth_callarg (t, 1)); |
2d76680f PC |
1514 | else if (TREE_CODE (t) == AGGR_INIT_EXPR |
1515 | && AGGR_INIT_ZERO_FIRST (t)) | |
86461cad JM |
1516 | init = build_zero_init (DECL_CONTEXT (fun), NULL_TREE, false); |
1517 | if (init) | |
1518 | { | |
1519 | tree op = get_nth_callarg (t, 0); | |
1520 | if (is_dummy_object (op)) | |
1521 | op = ctx->object; | |
1522 | else | |
1523 | op = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (op)), op); | |
1524 | tree set = build2 (MODIFY_EXPR, TREE_TYPE (op), op, init); | |
c8816908 JM |
1525 | new_ctx.call = &new_call; |
1526 | return cxx_eval_constant_expression (&new_ctx, set, lval, | |
86461cad JM |
1527 | non_constant_p, overflow_p); |
1528 | } | |
2d76680f PC |
1529 | } |
1530 | ||
81371eff JM |
1531 | /* We can't defer instantiating the function any longer. */ |
1532 | if (!DECL_INITIAL (fun) | |
1533 | && DECL_TEMPLOID_INSTANTIATION (fun)) | |
1534 | { | |
f065303f JM |
1535 | location_t save_loc = input_location; |
1536 | input_location = loc; | |
81371eff JM |
1537 | ++function_depth; |
1538 | instantiate_decl (fun, /*defer_ok*/false, /*expl_inst*/false); | |
1539 | --function_depth; | |
f065303f | 1540 | input_location = save_loc; |
81371eff JM |
1541 | } |
1542 | ||
2d76680f | 1543 | /* If in direct recursive call, optimize definition search. */ |
c8816908 | 1544 | if (ctx && ctx->call && ctx->call->fundef && ctx->call->fundef->decl == fun) |
3e605b20 | 1545 | new_call.fundef = ctx->call->fundef; |
2d76680f PC |
1546 | else |
1547 | { | |
1548 | new_call.fundef = retrieve_constexpr_fundef (fun); | |
4ddcdbf9 JM |
1549 | if (new_call.fundef == NULL || new_call.fundef->body == NULL |
1550 | || fun == current_function_decl) | |
2d76680f | 1551 | { |
2b3ab879 | 1552 | if (!ctx->quiet) |
2d76680f | 1553 | { |
4ddcdbf9 JM |
1554 | /* We need to check for current_function_decl here in case we're |
1555 | being called during cp_fold_function, because at that point | |
1556 | DECL_INITIAL is set properly and we have a fundef but we | |
1557 | haven't lowered invisirefs yet (c++/70344). */ | |
1558 | if (DECL_INITIAL (fun) == error_mark_node | |
1559 | || fun == current_function_decl) | |
ddd6d421 JM |
1560 | error_at (loc, "%qD called in a constant expression before its " |
1561 | "definition is complete", fun); | |
1562 | else if (DECL_INITIAL (fun)) | |
2d76680f | 1563 | { |
98e5a19a JM |
1564 | /* The definition of fun was somehow unsuitable. But pretend |
1565 | that lambda static thunks don't exist. */ | |
1566 | if (!lambda_static_thunk_p (fun)) | |
1567 | error_at (loc, "%qD called in a constant expression", fun); | |
2d76680f PC |
1568 | explain_invalid_constexpr_fn (fun); |
1569 | } | |
1570 | else | |
1571 | error_at (loc, "%qD used before its definition", fun); | |
1572 | } | |
1573 | *non_constant_p = true; | |
1574 | return t; | |
1575 | } | |
1576 | } | |
60813a46 | 1577 | |
12d9ce19 | 1578 | bool non_constant_args = false; |
3e605b20 | 1579 | cxx_bind_parameters_in_call (ctx, t, &new_call, |
12d9ce19 | 1580 | non_constant_p, overflow_p, &non_constant_args); |
2d76680f PC |
1581 | if (*non_constant_p) |
1582 | return t; | |
1583 | ||
1584 | depth_ok = push_cx_call_context (t); | |
1585 | ||
12d9ce19 | 1586 | tree result = NULL_TREE; |
2d76680f | 1587 | |
12d9ce19 | 1588 | constexpr_call *entry = NULL; |
cca444fb | 1589 | if (depth_ok && !non_constant_args) |
2d76680f | 1590 | { |
12d9ce19 JM |
1591 | new_call.hash = iterative_hash_template_arg |
1592 | (new_call.bindings, constexpr_fundef_hasher::hash (new_call.fundef)); | |
1593 | ||
1594 | /* If we have seen this call before, we are done. */ | |
1595 | maybe_initialize_constexpr_call_table (); | |
1596 | constexpr_call **slot | |
1597 | = constexpr_call_table->find_slot (&new_call, INSERT); | |
1598 | entry = *slot; | |
1599 | if (entry == NULL) | |
1600 | { | |
1601 | /* We need to keep a pointer to the entry, not just the slot, as the | |
1602 | slot can move in the call to cxx_eval_builtin_function_call. */ | |
1603 | *slot = entry = ggc_alloc<constexpr_call> (); | |
1604 | *entry = new_call; | |
1605 | } | |
4727d4c6 | 1606 | /* Calls that are in progress have their result set to NULL, |
12d9ce19 JM |
1607 | so that we can detect circular dependencies. */ |
1608 | else if (entry->result == NULL) | |
1609 | { | |
1610 | if (!ctx->quiet) | |
1611 | error ("call has circular dependency"); | |
1612 | *non_constant_p = true; | |
1613 | entry->result = result = error_mark_node; | |
1614 | } | |
1615 | else | |
1616 | result = entry->result; | |
2d76680f PC |
1617 | } |
1618 | ||
1619 | if (!depth_ok) | |
1620 | { | |
2b3ab879 | 1621 | if (!ctx->quiet) |
84fa214d | 1622 | error ("%<constexpr%> evaluation depth exceeds maximum of %d (use " |
2d76680f PC |
1623 | "-fconstexpr-depth= to increase the maximum)", |
1624 | max_constexpr_depth); | |
1625 | *non_constant_p = true; | |
12d9ce19 | 1626 | result = error_mark_node; |
2d76680f PC |
1627 | } |
1628 | else | |
1629 | { | |
de54de93 JM |
1630 | if (result && result != error_mark_node) |
1631 | /* OK */; | |
1632 | else if (!DECL_SAVED_TREE (fun)) | |
1633 | { | |
1634 | /* When at_eof >= 2, cgraph has started throwing away | |
1635 | DECL_SAVED_TREE, so fail quietly. FIXME we get here because of | |
1636 | late code generation for VEC_INIT_EXPR, which needs to be | |
1637 | completely reconsidered. */ | |
1638 | gcc_assert (at_eof >= 2 && ctx->quiet); | |
1639 | *non_constant_p = true; | |
1640 | } | |
1641 | else | |
3e605b20 | 1642 | { |
c0daf32d | 1643 | tree body, parms, res; |
0567dcd2 | 1644 | |
c0daf32d | 1645 | /* Reuse or create a new unshared copy of this function's body. */ |
97f3003f JM |
1646 | tree copy = get_fundef_copy (fun); |
1647 | body = TREE_PURPOSE (copy); | |
1648 | parms = TREE_VALUE (copy); | |
1649 | res = TREE_TYPE (copy); | |
0567dcd2 MP |
1650 | |
1651 | /* Associate the bindings with the remapped parms. */ | |
1652 | tree bound = new_call.bindings; | |
1653 | tree remapped = parms; | |
1654 | while (bound) | |
60813a46 | 1655 | { |
0567dcd2 MP |
1656 | tree oparm = TREE_PURPOSE (bound); |
1657 | tree arg = TREE_VALUE (bound); | |
1658 | gcc_assert (DECL_NAME (remapped) == DECL_NAME (oparm)); | |
7f0e23e9 | 1659 | /* Don't share a CONSTRUCTOR that might be changed. */ |
0146e25f | 1660 | arg = unshare_constructor (arg); |
0567dcd2 MP |
1661 | ctx->values->put (remapped, arg); |
1662 | bound = TREE_CHAIN (bound); | |
1663 | remapped = DECL_CHAIN (remapped); | |
60813a46 | 1664 | } |
0567dcd2 MP |
1665 | /* Add the RESULT_DECL to the values map, too. */ |
1666 | tree slot = NULL_TREE; | |
1667 | if (DECL_BY_REFERENCE (res)) | |
60813a46 | 1668 | { |
0567dcd2 MP |
1669 | slot = AGGR_INIT_EXPR_SLOT (t); |
1670 | tree addr = build_address (slot); | |
1671 | addr = build_nop (TREE_TYPE (res), addr); | |
1672 | ctx->values->put (res, addr); | |
1673 | ctx->values->put (slot, NULL_TREE); | |
1674 | } | |
1675 | else | |
1676 | ctx->values->put (res, NULL_TREE); | |
60813a46 | 1677 | |
c0daf32d PP |
1678 | /* Track the callee's evaluated SAVE_EXPRs so that we can forget |
1679 | their values after the call. */ | |
1680 | constexpr_ctx ctx_with_save_exprs = *ctx; | |
1681 | hash_set<tree> save_exprs; | |
1682 | ctx_with_save_exprs.save_exprs = &save_exprs; | |
1e163090 | 1683 | ctx_with_save_exprs.call = &new_call; |
c0daf32d | 1684 | |
0567dcd2 | 1685 | tree jump_target = NULL_TREE; |
c0daf32d | 1686 | cxx_eval_constant_expression (&ctx_with_save_exprs, body, |
0567dcd2 MP |
1687 | lval, non_constant_p, overflow_p, |
1688 | &jump_target); | |
60813a46 | 1689 | |
0567dcd2 MP |
1690 | if (DECL_CONSTRUCTOR_P (fun)) |
1691 | /* This can be null for a subobject constructor call, in | |
1692 | which case what we care about is the initialization | |
1693 | side-effects rather than the value. We could get at the | |
1694 | value by evaluating *this, but we don't bother; there's | |
1695 | no need to put such a call in the hash table. */ | |
1696 | result = lval ? ctx->object : ctx->ctor; | |
1697 | else if (VOID_TYPE_P (TREE_TYPE (res))) | |
1698 | result = void_node; | |
1699 | else | |
1700 | { | |
1701 | result = *ctx->values->get (slot ? slot : res); | |
1702 | if (result == NULL_TREE && !*non_constant_p) | |
60813a46 | 1703 | { |
0567dcd2 | 1704 | if (!ctx->quiet) |
84fa214d | 1705 | error ("%<constexpr%> call flows off the end " |
0567dcd2 MP |
1706 | "of the function"); |
1707 | *non_constant_p = true; | |
60813a46 | 1708 | } |
60813a46 | 1709 | } |
0567dcd2 | 1710 | |
c0daf32d PP |
1711 | /* Forget the saved values of the callee's SAVE_EXPRs. */ |
1712 | for (hash_set<tree>::iterator iter = save_exprs.begin(); | |
1713 | iter != save_exprs.end(); ++iter) | |
1714 | ctx_with_save_exprs.values->remove (*iter); | |
1715 | ||
0567dcd2 MP |
1716 | /* Remove the parms/result from the values map. Is it worth |
1717 | bothering to do this when the map itself is only live for | |
1718 | one constexpr evaluation? If so, maybe also clear out | |
1719 | other vars from call, maybe in BIND_EXPR handling? */ | |
1720 | ctx->values->remove (res); | |
1721 | if (slot) | |
1722 | ctx->values->remove (slot); | |
1723 | for (tree parm = parms; parm; parm = TREE_CHAIN (parm)) | |
1724 | ctx->values->remove (parm); | |
c0daf32d PP |
1725 | |
1726 | /* Make the unshared function copy we used available for re-use. */ | |
1727 | save_fundef_copy (fun, copy); | |
3e605b20 | 1728 | } |
60813a46 | 1729 | |
2d76680f PC |
1730 | if (result == error_mark_node) |
1731 | *non_constant_p = true; | |
52228180 | 1732 | if (*non_constant_p || *overflow_p) |
12d9ce19 | 1733 | result = error_mark_node; |
0567dcd2 | 1734 | else if (!result) |
60813a46 | 1735 | result = void_node; |
12d9ce19 JM |
1736 | if (entry) |
1737 | entry->result = result; | |
2d76680f PC |
1738 | } |
1739 | ||
f64e0c02 JM |
1740 | /* The result of a constexpr function must be completely initialized. */ |
1741 | if (TREE_CODE (result) == CONSTRUCTOR) | |
ecc57615 | 1742 | clear_no_implicit_zero (result); |
f64e0c02 | 1743 | |
2d76680f | 1744 | pop_cx_call_context (); |
0146e25f | 1745 | return unshare_constructor (result); |
2d76680f PC |
1746 | } |
1747 | ||
1748 | /* FIXME speed this up, it's taking 16% of compile time on sieve testcase. */ | |
1749 | ||
1750 | bool | |
1751 | reduced_constant_expression_p (tree t) | |
1752 | { | |
1753 | switch (TREE_CODE (t)) | |
1754 | { | |
1755 | case PTRMEM_CST: | |
1756 | /* Even if we can't lower this yet, it's constant. */ | |
1757 | return true; | |
1758 | ||
1759 | case CONSTRUCTOR: | |
1760 | /* And we need to handle PTRMEM_CST wrapped in a CONSTRUCTOR. */ | |
7368cfa4 JM |
1761 | tree idx, val, field; unsigned HOST_WIDE_INT i; |
1762 | if (CONSTRUCTOR_NO_IMPLICIT_ZERO (t)) | |
1763 | field = next_initializable_field (TYPE_FIELDS (TREE_TYPE (t))); | |
1764 | else | |
1765 | field = NULL_TREE; | |
1766 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (t), i, idx, val) | |
125db6a1 | 1767 | { |
7368cfa4 | 1768 | if (!val) |
125db6a1 JM |
1769 | /* We're in the middle of initializing this element. */ |
1770 | return false; | |
7368cfa4 | 1771 | if (!reduced_constant_expression_p (val)) |
125db6a1 | 1772 | return false; |
7368cfa4 JM |
1773 | if (field) |
1774 | { | |
1775 | if (idx != field) | |
1776 | return false; | |
1777 | field = next_initializable_field (DECL_CHAIN (field)); | |
1778 | } | |
125db6a1 | 1779 | } |
7368cfa4 JM |
1780 | if (field) |
1781 | return false; | |
1782 | else if (CONSTRUCTOR_NO_IMPLICIT_ZERO (t)) | |
1783 | /* All the fields are initialized. */ | |
1784 | CONSTRUCTOR_NO_IMPLICIT_ZERO (t) = false; | |
2d76680f PC |
1785 | return true; |
1786 | ||
1787 | default: | |
1788 | /* FIXME are we calling this too much? */ | |
1789 | return initializer_constant_valid_p (t, TREE_TYPE (t)) != NULL_TREE; | |
1790 | } | |
1791 | } | |
1792 | ||
1793 | /* Some expressions may have constant operands but are not constant | |
1794 | themselves, such as 1/0. Call this function (or rather, the macro | |
1795 | following it) to check for that condition. | |
1796 | ||
1797 | We only call this in places that require an arithmetic constant, not in | |
1798 | places where we might have a non-constant expression that can be a | |
1799 | component of a constant expression, such as the address of a constexpr | |
1800 | variable that might be dereferenced later. */ | |
1801 | ||
1802 | static bool | |
1803 | verify_constant (tree t, bool allow_non_constant, bool *non_constant_p, | |
1804 | bool *overflow_p) | |
1805 | { | |
1806 | if (!*non_constant_p && !reduced_constant_expression_p (t)) | |
1807 | { | |
1808 | if (!allow_non_constant) | |
1809 | error ("%q+E is not a constant expression", t); | |
1810 | *non_constant_p = true; | |
1811 | } | |
1812 | if (TREE_OVERFLOW_P (t)) | |
1813 | { | |
1814 | if (!allow_non_constant) | |
1815 | { | |
1816 | permerror (input_location, "overflow in constant expression"); | |
1817 | /* If we're being permissive (and are in an enforcing | |
1818 | context), ignore the overflow. */ | |
1819 | if (flag_permissive) | |
1820 | return *non_constant_p; | |
1821 | } | |
1822 | *overflow_p = true; | |
1823 | } | |
1824 | return *non_constant_p; | |
1825 | } | |
1826 | ||
253a921b MP |
1827 | /* Check whether the shift operation with code CODE and type TYPE on LHS |
1828 | and RHS is undefined. If it is, give an error with an explanation, | |
1829 | and return true; return false otherwise. */ | |
1830 | ||
1831 | static bool | |
1832 | cxx_eval_check_shift_p (location_t loc, const constexpr_ctx *ctx, | |
1833 | enum tree_code code, tree type, tree lhs, tree rhs) | |
1834 | { | |
1835 | if ((code != LSHIFT_EXPR && code != RSHIFT_EXPR) | |
1836 | || TREE_CODE (lhs) != INTEGER_CST | |
1837 | || TREE_CODE (rhs) != INTEGER_CST) | |
1838 | return false; | |
1839 | ||
1840 | tree lhstype = TREE_TYPE (lhs); | |
1841 | unsigned HOST_WIDE_INT uprec = TYPE_PRECISION (TREE_TYPE (lhs)); | |
1842 | ||
1843 | /* [expr.shift] The behavior is undefined if the right operand | |
1844 | is negative, or greater than or equal to the length in bits | |
1845 | of the promoted left operand. */ | |
1846 | if (tree_int_cst_sgn (rhs) == -1) | |
1847 | { | |
1848 | if (!ctx->quiet) | |
5342156c MP |
1849 | permerror (loc, "right operand of shift expression %q+E is negative", |
1850 | build2_loc (loc, code, type, lhs, rhs)); | |
1851 | return (!flag_permissive || ctx->quiet); | |
253a921b MP |
1852 | } |
1853 | if (compare_tree_int (rhs, uprec) >= 0) | |
1854 | { | |
1855 | if (!ctx->quiet) | |
5342156c MP |
1856 | permerror (loc, "right operand of shift expression %q+E is >= than " |
1857 | "the precision of the left operand", | |
1858 | build2_loc (loc, code, type, lhs, rhs)); | |
1859 | return (!flag_permissive || ctx->quiet); | |
253a921b MP |
1860 | } |
1861 | ||
1862 | /* The value of E1 << E2 is E1 left-shifted E2 bit positions; [...] | |
1863 | if E1 has a signed type and non-negative value, and E1x2^E2 is | |
1864 | representable in the corresponding unsigned type of the result type, | |
1865 | then that value, converted to the result type, is the resulting value; | |
1866 | otherwise, the behavior is undefined. */ | |
1867 | if (code == LSHIFT_EXPR && !TYPE_UNSIGNED (lhstype) | |
1868 | && (cxx_dialect >= cxx11)) | |
1869 | { | |
1870 | if (tree_int_cst_sgn (lhs) == -1) | |
1871 | { | |
1872 | if (!ctx->quiet) | |
5342156c MP |
1873 | permerror (loc, |
1874 | "left operand of shift expression %q+E is negative", | |
1875 | build2_loc (loc, code, type, lhs, rhs)); | |
1876 | return (!flag_permissive || ctx->quiet); | |
253a921b MP |
1877 | } |
1878 | /* For signed x << y the following: | |
1879 | (unsigned) x >> ((prec (lhs) - 1) - y) | |
1880 | if > 1, is undefined. The right-hand side of this formula | |
1881 | is the highest bit of the LHS that can be set (starting from 0), | |
1882 | so that the shift doesn't overflow. We then right-shift the LHS | |
1883 | to see whether any other bit is set making the original shift | |
1884 | undefined -- the result is not representable in the corresponding | |
1885 | unsigned type. */ | |
1886 | tree t = build_int_cst (unsigned_type_node, uprec - 1); | |
1887 | t = fold_build2 (MINUS_EXPR, unsigned_type_node, t, rhs); | |
1888 | tree ulhs = fold_convert (unsigned_type_for (lhstype), lhs); | |
1889 | t = fold_build2 (RSHIFT_EXPR, TREE_TYPE (ulhs), ulhs, t); | |
1890 | if (tree_int_cst_lt (integer_one_node, t)) | |
1891 | { | |
1892 | if (!ctx->quiet) | |
5342156c MP |
1893 | permerror (loc, "shift expression %q+E overflows", |
1894 | build2_loc (loc, code, type, lhs, rhs)); | |
1895 | return (!flag_permissive || ctx->quiet); | |
253a921b MP |
1896 | } |
1897 | } | |
1898 | return false; | |
1899 | } | |
1900 | ||
2d76680f PC |
1901 | /* Subroutine of cxx_eval_constant_expression. |
1902 | Attempt to reduce the unary expression tree T to a compile time value. | |
1903 | If successful, return the value. Otherwise issue a diagnostic | |
1904 | and return error_mark_node. */ | |
1905 | ||
1906 | static tree | |
3e605b20 | 1907 | cxx_eval_unary_expression (const constexpr_ctx *ctx, tree t, |
12d9ce19 | 1908 | bool /*lval*/, |
2d76680f PC |
1909 | bool *non_constant_p, bool *overflow_p) |
1910 | { | |
1911 | tree r; | |
1912 | tree orig_arg = TREE_OPERAND (t, 0); | |
12d9ce19 JM |
1913 | tree arg = cxx_eval_constant_expression (ctx, orig_arg, /*lval*/false, |
1914 | non_constant_p, overflow_p); | |
2d76680f | 1915 | VERIFY_CONSTANT (arg); |
f899317e JM |
1916 | location_t loc = EXPR_LOCATION (t); |
1917 | enum tree_code code = TREE_CODE (t); | |
1918 | tree type = TREE_TYPE (t); | |
1919 | r = fold_unary_loc (loc, code, type, arg); | |
1920 | if (r == NULL_TREE) | |
1921 | { | |
1922 | if (arg == orig_arg) | |
1923 | r = t; | |
1924 | else | |
1925 | r = build1_loc (loc, code, type, arg); | |
1926 | } | |
2d76680f PC |
1927 | VERIFY_CONSTANT (r); |
1928 | return r; | |
1929 | } | |
1930 | ||
ea8661cd JJ |
1931 | /* Helper function for cxx_eval_binary_expression. Try to optimize |
1932 | original POINTER_PLUS_EXPR T, LHS p+ RHS, return NULL_TREE if the | |
1933 | generic folding should be used. */ | |
1934 | ||
1935 | static tree | |
1936 | cxx_fold_pointer_plus_expression (const constexpr_ctx *ctx, tree t, | |
1937 | tree lhs, tree rhs, bool *non_constant_p, | |
1938 | bool *overflow_p) | |
1939 | { | |
1940 | STRIP_NOPS (lhs); | |
1941 | if (TREE_CODE (lhs) != ADDR_EXPR) | |
1942 | return NULL_TREE; | |
1943 | ||
1944 | lhs = TREE_OPERAND (lhs, 0); | |
1945 | ||
1946 | /* &A[i] p+ j => &A[i + j] */ | |
1947 | if (TREE_CODE (lhs) == ARRAY_REF | |
1948 | && TREE_CODE (TREE_OPERAND (lhs, 1)) == INTEGER_CST | |
1949 | && TREE_CODE (rhs) == INTEGER_CST | |
1950 | && TYPE_SIZE_UNIT (TREE_TYPE (lhs)) | |
1951 | && TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (lhs))) == INTEGER_CST) | |
1952 | { | |
1953 | tree orig_type = TREE_TYPE (t); | |
1954 | location_t loc = EXPR_LOCATION (t); | |
1955 | tree type = TREE_TYPE (lhs); | |
1956 | ||
1957 | t = fold_convert_loc (loc, ssizetype, TREE_OPERAND (lhs, 1)); | |
1958 | tree nelts = array_type_nelts_top (TREE_TYPE (TREE_OPERAND (lhs, 0))); | |
1959 | nelts = cxx_eval_constant_expression (ctx, nelts, false, non_constant_p, | |
1960 | overflow_p); | |
1961 | if (*non_constant_p) | |
1962 | return NULL_TREE; | |
1963 | /* Don't fold an out-of-bound access. */ | |
1964 | if (!tree_int_cst_le (t, nelts)) | |
1965 | return NULL_TREE; | |
1966 | rhs = cp_fold_convert (ssizetype, rhs); | |
1967 | /* Don't fold if rhs can't be divided exactly by TYPE_SIZE_UNIT. | |
1968 | constexpr int A[1]; ... (char *)&A[0] + 1 */ | |
1969 | if (!integer_zerop (fold_build2_loc (loc, TRUNC_MOD_EXPR, sizetype, | |
1970 | rhs, TYPE_SIZE_UNIT (type)))) | |
1971 | return NULL_TREE; | |
1972 | /* Make sure to treat the second operand of POINTER_PLUS_EXPR | |
1973 | as signed. */ | |
1974 | rhs = fold_build2_loc (loc, EXACT_DIV_EXPR, ssizetype, rhs, | |
1975 | TYPE_SIZE_UNIT (type)); | |
1976 | t = size_binop_loc (loc, PLUS_EXPR, rhs, t); | |
1977 | t = build4_loc (loc, ARRAY_REF, type, TREE_OPERAND (lhs, 0), | |
1978 | t, NULL_TREE, NULL_TREE); | |
1979 | t = cp_build_addr_expr (t, tf_warning_or_error); | |
1980 | t = cp_fold_convert (orig_type, t); | |
1981 | return cxx_eval_constant_expression (ctx, t, /*lval*/false, | |
1982 | non_constant_p, overflow_p); | |
1983 | } | |
1984 | ||
1985 | return NULL_TREE; | |
1986 | } | |
1987 | ||
2d76680f PC |
1988 | /* Subroutine of cxx_eval_constant_expression. |
1989 | Like cxx_eval_unary_expression, except for binary expressions. */ | |
1990 | ||
1991 | static tree | |
3e605b20 | 1992 | cxx_eval_binary_expression (const constexpr_ctx *ctx, tree t, |
12d9ce19 | 1993 | bool /*lval*/, |
2d76680f PC |
1994 | bool *non_constant_p, bool *overflow_p) |
1995 | { | |
618d6c1c | 1996 | tree r = NULL_TREE; |
2d76680f PC |
1997 | tree orig_lhs = TREE_OPERAND (t, 0); |
1998 | tree orig_rhs = TREE_OPERAND (t, 1); | |
1999 | tree lhs, rhs; | |
12d9ce19 | 2000 | lhs = cxx_eval_constant_expression (ctx, orig_lhs, /*lval*/false, |
5a804683 | 2001 | non_constant_p, overflow_p); |
c8a66fc9 JM |
2002 | /* Don't VERIFY_CONSTANT here, it's unnecessary and will break pointer |
2003 | subtraction. */ | |
2004 | if (*non_constant_p) | |
2005 | return t; | |
12d9ce19 | 2006 | rhs = cxx_eval_constant_expression (ctx, orig_rhs, /*lval*/false, |
5a804683 | 2007 | non_constant_p, overflow_p); |
c8a66fc9 JM |
2008 | if (*non_constant_p) |
2009 | return t; | |
f899317e JM |
2010 | |
2011 | location_t loc = EXPR_LOCATION (t); | |
2012 | enum tree_code code = TREE_CODE (t); | |
2013 | tree type = TREE_TYPE (t); | |
618d6c1c PP |
2014 | |
2015 | if (code == EQ_EXPR || code == NE_EXPR) | |
2016 | { | |
2017 | bool is_code_eq = (code == EQ_EXPR); | |
2018 | ||
2019 | if (TREE_CODE (lhs) == PTRMEM_CST | |
2020 | && TREE_CODE (rhs) == PTRMEM_CST) | |
2021 | r = constant_boolean_node (cp_tree_equal (lhs, rhs) == is_code_eq, | |
2022 | type); | |
2023 | else if ((TREE_CODE (lhs) == PTRMEM_CST | |
2024 | || TREE_CODE (rhs) == PTRMEM_CST) | |
2025 | && (null_member_pointer_value_p (lhs) | |
2026 | || null_member_pointer_value_p (rhs))) | |
2027 | r = constant_boolean_node (!is_code_eq, type); | |
dd5dda56 JM |
2028 | else if (TREE_CODE (lhs) == PTRMEM_CST) |
2029 | lhs = cplus_expand_constant (lhs); | |
2030 | else if (TREE_CODE (rhs) == PTRMEM_CST) | |
2031 | rhs = cplus_expand_constant (rhs); | |
618d6c1c | 2032 | } |
8bada5cd MS |
2033 | if (code == POINTER_PLUS_EXPR && !*non_constant_p |
2034 | && integer_zerop (lhs) && !integer_zerop (rhs)) | |
2035 | { | |
2036 | if (!ctx->quiet) | |
2037 | error ("arithmetic involving a null pointer in %qE", lhs); | |
2038 | return t; | |
2039 | } | |
ea8661cd JJ |
2040 | else if (code == POINTER_PLUS_EXPR) |
2041 | r = cxx_fold_pointer_plus_expression (ctx, t, lhs, rhs, non_constant_p, | |
2042 | overflow_p); | |
618d6c1c PP |
2043 | |
2044 | if (r == NULL_TREE) | |
2045 | r = fold_binary_loc (loc, code, type, lhs, rhs); | |
2046 | ||
f899317e JM |
2047 | if (r == NULL_TREE) |
2048 | { | |
2049 | if (lhs == orig_lhs && rhs == orig_rhs) | |
2050 | r = t; | |
2051 | else | |
2052 | r = build2_loc (loc, code, type, lhs, rhs); | |
2053 | } | |
253a921b MP |
2054 | else if (cxx_eval_check_shift_p (loc, ctx, code, type, lhs, rhs)) |
2055 | *non_constant_p = true; | |
c8a66fc9 JM |
2056 | /* Don't VERIFY_CONSTANT if this might be dealing with a pointer to |
2057 | a local array in a constexpr function. */ | |
2058 | bool ptr = POINTER_TYPE_P (TREE_TYPE (lhs)); | |
caee690e | 2059 | if (!ptr) |
134efa82 | 2060 | VERIFY_CONSTANT (r); |
2d76680f PC |
2061 | return r; |
2062 | } | |
2063 | ||
2064 | /* Subroutine of cxx_eval_constant_expression. | |
2065 | Attempt to evaluate condition expressions. Dead branches are not | |
2066 | looked into. */ | |
2067 | ||
2068 | static tree | |
3e605b20 | 2069 | cxx_eval_conditional_expression (const constexpr_ctx *ctx, tree t, |
92a596e8 | 2070 | bool lval, |
56632b27 JM |
2071 | bool *non_constant_p, bool *overflow_p, |
2072 | tree *jump_target) | |
2d76680f | 2073 | { |
3e605b20 | 2074 | tree val = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), |
12d9ce19 | 2075 | /*lval*/false, |
5a804683 | 2076 | non_constant_p, overflow_p); |
2d76680f PC |
2077 | VERIFY_CONSTANT (val); |
2078 | /* Don't VERIFY_CONSTANT the other operands. */ | |
2079 | if (integer_zerop (val)) | |
3e605b20 | 2080 | return cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 2), |
92a596e8 | 2081 | lval, |
56632b27 JM |
2082 | non_constant_p, overflow_p, |
2083 | jump_target); | |
3e605b20 | 2084 | return cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), |
92a596e8 | 2085 | lval, |
56632b27 JM |
2086 | non_constant_p, overflow_p, |
2087 | jump_target); | |
2d76680f PC |
2088 | } |
2089 | ||
f370e36d JJ |
2090 | /* Subroutine of cxx_eval_constant_expression. |
2091 | Attempt to evaluate vector condition expressions. Unlike | |
2092 | cxx_eval_conditional_expression, VEC_COND_EXPR acts like a normal | |
2093 | ternary arithmetics operation, where all 3 arguments have to be | |
2094 | evaluated as constants and then folding computes the result from | |
2095 | them. */ | |
2096 | ||
2097 | static tree | |
2098 | cxx_eval_vector_conditional_expression (const constexpr_ctx *ctx, tree t, | |
2099 | bool *non_constant_p, bool *overflow_p) | |
2100 | { | |
2101 | tree arg1 = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), | |
2102 | /*lval*/false, | |
2103 | non_constant_p, overflow_p); | |
2104 | VERIFY_CONSTANT (arg1); | |
2105 | tree arg2 = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), | |
2106 | /*lval*/false, | |
2107 | non_constant_p, overflow_p); | |
2108 | VERIFY_CONSTANT (arg2); | |
2109 | tree arg3 = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 2), | |
2110 | /*lval*/false, | |
2111 | non_constant_p, overflow_p); | |
2112 | VERIFY_CONSTANT (arg3); | |
2113 | location_t loc = EXPR_LOCATION (t); | |
2114 | tree type = TREE_TYPE (t); | |
2115 | tree r = fold_ternary_loc (loc, VEC_COND_EXPR, type, arg1, arg2, arg3); | |
2116 | if (r == NULL_TREE) | |
2117 | { | |
2118 | if (arg1 == TREE_OPERAND (t, 0) | |
2119 | && arg2 == TREE_OPERAND (t, 1) | |
2120 | && arg3 == TREE_OPERAND (t, 2)) | |
2121 | r = t; | |
2122 | else | |
2123 | r = build3_loc (loc, VEC_COND_EXPR, type, arg1, arg2, arg3); | |
2124 | } | |
2125 | VERIFY_CONSTANT (r); | |
2126 | return r; | |
2127 | } | |
2128 | ||
ceaaf873 JM |
2129 | /* Returns less than, equal to, or greater than zero if KEY is found to be |
2130 | less than, to match, or to be greater than the constructor_elt's INDEX. */ | |
2131 | ||
2132 | static int | |
2133 | array_index_cmp (tree key, tree index) | |
2134 | { | |
2135 | gcc_assert (TREE_CODE (key) == INTEGER_CST); | |
2136 | ||
2137 | switch (TREE_CODE (index)) | |
2138 | { | |
2139 | case INTEGER_CST: | |
2140 | return tree_int_cst_compare (key, index); | |
2141 | case RANGE_EXPR: | |
2142 | { | |
2143 | tree lo = TREE_OPERAND (index, 0); | |
2144 | tree hi = TREE_OPERAND (index, 1); | |
2145 | if (tree_int_cst_lt (key, lo)) | |
2146 | return -1; | |
2147 | else if (tree_int_cst_lt (hi, key)) | |
2148 | return 1; | |
2149 | else | |
2150 | return 0; | |
2151 | } | |
2152 | default: | |
2153 | gcc_unreachable (); | |
2154 | } | |
2155 | } | |
2156 | ||
2157 | /* Returns the index of the constructor_elt of ARY which matches DINDEX, or -1 | |
2158 | if none. If INSERT is true, insert a matching element rather than fail. */ | |
2159 | ||
2160 | static HOST_WIDE_INT | |
2161 | find_array_ctor_elt (tree ary, tree dindex, bool insert = false) | |
2162 | { | |
2163 | if (tree_int_cst_sgn (dindex) < 0) | |
2164 | return -1; | |
2165 | ||
2166 | unsigned HOST_WIDE_INT i = tree_to_uhwi (dindex); | |
2167 | vec<constructor_elt, va_gc> *elts = CONSTRUCTOR_ELTS (ary); | |
2168 | unsigned HOST_WIDE_INT len = vec_safe_length (elts); | |
2169 | ||
2170 | unsigned HOST_WIDE_INT end = len; | |
2171 | unsigned HOST_WIDE_INT begin = 0; | |
2172 | ||
2173 | /* If the last element of the CONSTRUCTOR has its own index, we can assume | |
2174 | that the same is true of the other elements and index directly. */ | |
2175 | if (end > 0) | |
2176 | { | |
2177 | tree cindex = (*elts)[end-1].index; | |
2178 | if (TREE_CODE (cindex) == INTEGER_CST | |
2179 | && compare_tree_int (cindex, end-1) == 0) | |
2180 | { | |
2181 | if (i < end) | |
2182 | return i; | |
2183 | else | |
2184 | begin = end; | |
2185 | } | |
2186 | } | |
2187 | ||
2188 | /* Otherwise, find a matching index by means of a binary search. */ | |
2189 | while (begin != end) | |
2190 | { | |
2191 | unsigned HOST_WIDE_INT middle = (begin + end) / 2; | |
a7ccb9e7 JM |
2192 | constructor_elt &elt = (*elts)[middle]; |
2193 | tree idx = elt.index; | |
ceaaf873 | 2194 | |
a7ccb9e7 | 2195 | int cmp = array_index_cmp (dindex, idx); |
ceaaf873 JM |
2196 | if (cmp < 0) |
2197 | end = middle; | |
2198 | else if (cmp > 0) | |
2199 | begin = middle + 1; | |
2200 | else | |
a7ccb9e7 JM |
2201 | { |
2202 | if (insert && TREE_CODE (idx) == RANGE_EXPR) | |
2203 | { | |
2204 | /* We need to split the range. */ | |
2205 | constructor_elt e; | |
2206 | tree lo = TREE_OPERAND (idx, 0); | |
2207 | tree hi = TREE_OPERAND (idx, 1); | |
2208 | if (tree_int_cst_lt (lo, dindex)) | |
2209 | { | |
2210 | /* There are still some lower elts; shorten the range. */ | |
2211 | tree new_hi = int_const_binop (MINUS_EXPR, dindex, | |
2212 | size_one_node); | |
2213 | if (tree_int_cst_equal (lo, new_hi)) | |
2214 | /* Only one element left, no longer a range. */ | |
2215 | elt.index = lo; | |
2216 | else | |
2217 | TREE_OPERAND (idx, 1) = new_hi; | |
2218 | /* Append the element we want to insert. */ | |
2219 | ++middle; | |
2220 | e.index = dindex; | |
0146e25f | 2221 | e.value = unshare_constructor (elt.value); |
a7ccb9e7 JM |
2222 | vec_safe_insert (CONSTRUCTOR_ELTS (ary), middle, e); |
2223 | } | |
2224 | else | |
2225 | /* No lower elts, the range elt is now ours. */ | |
2226 | elt.index = dindex; | |
2227 | ||
2228 | if (tree_int_cst_lt (dindex, hi)) | |
2229 | { | |
2230 | /* There are still some higher elts; append a range. */ | |
2231 | tree new_lo = int_const_binop (PLUS_EXPR, dindex, | |
2232 | size_one_node); | |
2233 | if (tree_int_cst_equal (new_lo, hi)) | |
2234 | e.index = hi; | |
2235 | else | |
2236 | e.index = build2 (RANGE_EXPR, sizetype, new_lo, hi); | |
0146e25f | 2237 | e.value = unshare_constructor (elt.value); |
a7ccb9e7 JM |
2238 | vec_safe_insert (CONSTRUCTOR_ELTS (ary), middle+1, e); |
2239 | } | |
2240 | } | |
2241 | return middle; | |
2242 | } | |
ceaaf873 JM |
2243 | } |
2244 | ||
2245 | if (insert) | |
2246 | { | |
2247 | constructor_elt e = { dindex, NULL_TREE }; | |
2248 | vec_safe_insert (CONSTRUCTOR_ELTS (ary), end, e); | |
2249 | return end; | |
2250 | } | |
2251 | ||
2252 | return -1; | |
2253 | } | |
2254 | ||
abdc16c8 MS |
2255 | /* Under the control of CTX, issue a detailed diagnostic for |
2256 | an out-of-bounds subscript INDEX into the expression ARRAY. */ | |
2257 | ||
2258 | static void | |
2259 | diag_array_subscript (const constexpr_ctx *ctx, tree array, tree index) | |
2260 | { | |
2261 | if (!ctx->quiet) | |
2262 | { | |
2263 | tree arraytype = TREE_TYPE (array); | |
2264 | ||
2265 | /* Convert the unsigned array subscript to a signed integer to avoid | |
2266 | printing huge numbers for small negative values. */ | |
2267 | tree sidx = fold_convert (ssizetype, index); | |
2268 | if (DECL_P (array)) | |
2269 | { | |
2270 | error ("array subscript value %qE is outside the bounds " | |
2271 | "of array %qD of type %qT", sidx, array, arraytype); | |
2272 | inform (DECL_SOURCE_LOCATION (array), "declared here"); | |
2273 | } | |
2274 | else | |
2275 | error ("array subscript value %qE is outside the bounds " | |
2276 | "of array type %qT", sidx, arraytype); | |
2277 | } | |
2278 | } | |
ceaaf873 | 2279 | |
d6b46fca NS |
2280 | /* Extract element INDEX consisting of CHARS_PER_ELT chars from |
2281 | STRING_CST STRING. */ | |
2282 | ||
2283 | static tree | |
2284 | extract_string_elt (tree string, unsigned chars_per_elt, unsigned index) | |
2285 | { | |
2286 | tree type = cv_unqualified (TREE_TYPE (TREE_TYPE (string))); | |
2287 | tree r; | |
2288 | ||
2289 | if (chars_per_elt == 1) | |
2290 | r = build_int_cst (type, TREE_STRING_POINTER (string)[index]); | |
2291 | else | |
2292 | { | |
2293 | const unsigned char *ptr | |
2294 | = ((const unsigned char *)TREE_STRING_POINTER (string) | |
2295 | + index * chars_per_elt); | |
2296 | r = native_interpret_expr (type, ptr, chars_per_elt); | |
2297 | } | |
2298 | return r; | |
2299 | } | |
2300 | ||
2d76680f PC |
2301 | /* Subroutine of cxx_eval_constant_expression. |
2302 | Attempt to reduce a reference to an array slot. */ | |
2303 | ||
2304 | static tree | |
3e605b20 | 2305 | cxx_eval_array_reference (const constexpr_ctx *ctx, tree t, |
92a596e8 | 2306 | bool lval, |
2d76680f PC |
2307 | bool *non_constant_p, bool *overflow_p) |
2308 | { | |
2309 | tree oldary = TREE_OPERAND (t, 0); | |
3e605b20 | 2310 | tree ary = cxx_eval_constant_expression (ctx, oldary, |
92a596e8 | 2311 | lval, |
5a804683 | 2312 | non_constant_p, overflow_p); |
2d76680f | 2313 | tree index, oldidx; |
bc2a38df JJ |
2314 | HOST_WIDE_INT i = 0; |
2315 | tree elem_type = NULL_TREE; | |
2316 | unsigned len = 0, elem_nchars = 1; | |
2d76680f PC |
2317 | if (*non_constant_p) |
2318 | return t; | |
2319 | oldidx = TREE_OPERAND (t, 1); | |
3e605b20 | 2320 | index = cxx_eval_constant_expression (ctx, oldidx, |
2b3ab879 | 2321 | false, |
5a804683 | 2322 | non_constant_p, overflow_p); |
2d76680f | 2323 | VERIFY_CONSTANT (index); |
bc2a38df | 2324 | if (!lval) |
2d76680f | 2325 | { |
bc2a38df JJ |
2326 | elem_type = TREE_TYPE (TREE_TYPE (ary)); |
2327 | if (TREE_CODE (ary) == VIEW_CONVERT_EXPR | |
2328 | && VECTOR_TYPE_P (TREE_TYPE (TREE_OPERAND (ary, 0))) | |
2329 | && TREE_TYPE (t) == TREE_TYPE (TREE_TYPE (TREE_OPERAND (ary, 0)))) | |
2330 | ary = TREE_OPERAND (ary, 0); | |
2331 | if (TREE_CODE (ary) == CONSTRUCTOR) | |
2332 | len = CONSTRUCTOR_NELTS (ary); | |
2333 | else if (TREE_CODE (ary) == STRING_CST) | |
2334 | { | |
2335 | elem_nchars = (TYPE_PRECISION (elem_type) | |
2336 | / TYPE_PRECISION (char_type_node)); | |
2337 | len = (unsigned) TREE_STRING_LENGTH (ary) / elem_nchars; | |
2338 | } | |
2339 | else if (TREE_CODE (ary) == VECTOR_CST) | |
2340 | len = VECTOR_CST_NELTS (ary); | |
2341 | else | |
2342 | { | |
2343 | /* We can't do anything with other tree codes, so use | |
2344 | VERIFY_CONSTANT to complain and fail. */ | |
2345 | VERIFY_CONSTANT (ary); | |
2346 | gcc_unreachable (); | |
2347 | } | |
3b9997bb | 2348 | |
bc2a38df JJ |
2349 | if (!tree_fits_shwi_p (index) |
2350 | || (i = tree_to_shwi (index)) < 0) | |
2351 | { | |
2352 | diag_array_subscript (ctx, ary, index); | |
2353 | *non_constant_p = true; | |
2354 | return t; | |
2355 | } | |
ceaaf873 JM |
2356 | } |
2357 | ||
f17a223d RB |
2358 | tree nelts; |
2359 | if (TREE_CODE (TREE_TYPE (ary)) == ARRAY_TYPE) | |
2360 | nelts = array_type_nelts_top (TREE_TYPE (ary)); | |
2361 | else if (VECTOR_TYPE_P (TREE_TYPE (ary))) | |
2362 | nelts = size_int (TYPE_VECTOR_SUBPARTS (TREE_TYPE (ary))); | |
2363 | else | |
2364 | gcc_unreachable (); | |
2365 | ||
5453bfed MP |
2366 | /* For VLAs, the number of elements won't be an integer constant. */ |
2367 | nelts = cxx_eval_constant_expression (ctx, nelts, false, non_constant_p, | |
2368 | overflow_p); | |
2369 | VERIFY_CONSTANT (nelts); | |
3bb43119 JJ |
2370 | if ((lval |
2371 | ? !tree_int_cst_le (index, nelts) | |
2372 | : !tree_int_cst_lt (index, nelts)) | |
2373 | || tree_int_cst_sgn (index) < 0) | |
5453bfed | 2374 | { |
abdc16c8 | 2375 | diag_array_subscript (ctx, ary, index); |
5453bfed MP |
2376 | *non_constant_p = true; |
2377 | return t; | |
2378 | } | |
2379 | ||
bc2a38df JJ |
2380 | if (lval && ary == oldary && index == oldidx) |
2381 | return t; | |
2382 | else if (lval) | |
2383 | return build4 (ARRAY_REF, TREE_TYPE (t), ary, index, NULL, NULL); | |
2384 | ||
ceaaf873 JM |
2385 | bool found; |
2386 | if (TREE_CODE (ary) == CONSTRUCTOR) | |
2387 | { | |
2388 | HOST_WIDE_INT ix = find_array_ctor_elt (ary, index); | |
2389 | found = (ix >= 0); | |
2390 | if (found) | |
2391 | i = ix; | |
3b9997bb | 2392 | } |
ceaaf873 JM |
2393 | else |
2394 | found = (i < len); | |
3b9997bb | 2395 | |
fd2bfee5 JM |
2396 | if (found) |
2397 | { | |
2398 | tree r; | |
2399 | if (TREE_CODE (ary) == CONSTRUCTOR) | |
2400 | r = (*CONSTRUCTOR_ELTS (ary))[i].value; | |
2401 | else if (TREE_CODE (ary) == VECTOR_CST) | |
2402 | r = VECTOR_CST_ELT (ary, i); | |
fd2bfee5 | 2403 | else |
d6b46fca NS |
2404 | r = extract_string_elt (ary, elem_nchars, i); |
2405 | ||
fd2bfee5 JM |
2406 | if (r) |
2407 | /* Don't VERIFY_CONSTANT here. */ | |
2408 | return r; | |
2d76680f | 2409 | |
fd2bfee5 | 2410 | /* Otherwise the element doesn't have a value yet. */ |
2d76680f | 2411 | } |
3b9997bb | 2412 | |
fd2bfee5 JM |
2413 | /* Not found. */ |
2414 | ||
2415 | if (TREE_CODE (ary) == CONSTRUCTOR | |
2416 | && CONSTRUCTOR_NO_IMPLICIT_ZERO (ary)) | |
2d76680f | 2417 | { |
fd2bfee5 JM |
2418 | /* 'ary' is part of the aggregate initializer we're currently |
2419 | building; if there's no initializer for this element yet, | |
2420 | that's an error. */ | |
2421 | if (!ctx->quiet) | |
2422 | error ("accessing uninitialized array element"); | |
2423 | *non_constant_p = true; | |
2424 | return t; | |
2d76680f | 2425 | } |
fd2bfee5 JM |
2426 | |
2427 | /* If it's within the array bounds but doesn't have an explicit | |
2428 | initializer, it's value-initialized. */ | |
2429 | tree val = build_value_init (elem_type, tf_warning_or_error); | |
2430 | return cxx_eval_constant_expression (ctx, val, lval, non_constant_p, | |
2431 | overflow_p); | |
2d76680f PC |
2432 | } |
2433 | ||
2434 | /* Subroutine of cxx_eval_constant_expression. | |
2435 | Attempt to reduce a field access of a value of class type. */ | |
2436 | ||
2437 | static tree | |
3e605b20 | 2438 | cxx_eval_component_reference (const constexpr_ctx *ctx, tree t, |
92a596e8 | 2439 | bool lval, |
2d76680f PC |
2440 | bool *non_constant_p, bool *overflow_p) |
2441 | { | |
2442 | unsigned HOST_WIDE_INT i; | |
2443 | tree field; | |
2444 | tree value; | |
2445 | tree part = TREE_OPERAND (t, 1); | |
2446 | tree orig_whole = TREE_OPERAND (t, 0); | |
3e605b20 | 2447 | tree whole = cxx_eval_constant_expression (ctx, orig_whole, |
92a596e8 | 2448 | lval, |
5a804683 | 2449 | non_constant_p, overflow_p); |
8bada5cd MS |
2450 | if (TREE_CODE (whole) == INDIRECT_REF |
2451 | && integer_zerop (TREE_OPERAND (whole, 0)) | |
2452 | && !ctx->quiet) | |
2453 | error ("dereferencing a null pointer in %qE", orig_whole); | |
2454 | ||
dcdbc004 JM |
2455 | if (TREE_CODE (whole) == PTRMEM_CST) |
2456 | whole = cplus_expand_constant (whole); | |
2d76680f PC |
2457 | if (whole == orig_whole) |
2458 | return t; | |
92a596e8 | 2459 | if (lval) |
2d76680f PC |
2460 | return fold_build3 (COMPONENT_REF, TREE_TYPE (t), |
2461 | whole, part, NULL_TREE); | |
2462 | /* Don't VERIFY_CONSTANT here; we only want to check that we got a | |
2463 | CONSTRUCTOR. */ | |
2464 | if (!*non_constant_p && TREE_CODE (whole) != CONSTRUCTOR) | |
2465 | { | |
2b3ab879 | 2466 | if (!ctx->quiet) |
2d76680f PC |
2467 | error ("%qE is not a constant expression", orig_whole); |
2468 | *non_constant_p = true; | |
2469 | } | |
2470 | if (DECL_MUTABLE_P (part)) | |
2471 | { | |
2b3ab879 | 2472 | if (!ctx->quiet) |
2d76680f PC |
2473 | error ("mutable %qD is not usable in a constant expression", part); |
2474 | *non_constant_p = true; | |
2475 | } | |
2476 | if (*non_constant_p) | |
2477 | return t; | |
2db613e5 | 2478 | bool pmf = TYPE_PTRMEMFUNC_P (TREE_TYPE (whole)); |
2d76680f PC |
2479 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (whole), i, field, value) |
2480 | { | |
2db613e5 JM |
2481 | /* Use name match for PMF fields, as a variant will have a |
2482 | different FIELD_DECL with a different type. */ | |
2483 | if (pmf ? DECL_NAME (field) == DECL_NAME (part) | |
2484 | : field == part) | |
60813a46 JM |
2485 | { |
2486 | if (value) | |
2487 | return value; | |
2488 | else | |
2489 | /* We're in the middle of initializing it. */ | |
2490 | break; | |
2491 | } | |
2d76680f PC |
2492 | } |
2493 | if (TREE_CODE (TREE_TYPE (whole)) == UNION_TYPE | |
2494 | && CONSTRUCTOR_NELTS (whole) > 0) | |
2495 | { | |
2496 | /* DR 1188 says we don't have to deal with this. */ | |
2b3ab879 | 2497 | if (!ctx->quiet) |
2d76680f PC |
2498 | error ("accessing %qD member instead of initialized %qD member in " |
2499 | "constant expression", part, CONSTRUCTOR_ELT (whole, 0)->index); | |
2500 | *non_constant_p = true; | |
2501 | return t; | |
2502 | } | |
2503 | ||
188e53bd JM |
2504 | /* We only create a CONSTRUCTOR for a subobject when we modify it, so empty |
2505 | classes never get represented; throw together a value now. */ | |
2506 | if (is_really_empty_class (TREE_TYPE (t))) | |
2507 | return build_constructor (TREE_TYPE (t), NULL); | |
2508 | ||
2db613e5 JM |
2509 | gcc_assert (DECL_CONTEXT (part) == TYPE_MAIN_VARIANT (TREE_TYPE (whole))); |
2510 | ||
188e53bd | 2511 | if (CONSTRUCTOR_NO_IMPLICIT_ZERO (whole)) |
3e605b20 JM |
2512 | { |
2513 | /* 'whole' is part of the aggregate initializer we're currently | |
2514 | building; if there's no initializer for this member yet, that's an | |
188e53bd | 2515 | error. */ |
2b3ab879 | 2516 | if (!ctx->quiet) |
3e605b20 JM |
2517 | error ("accessing uninitialized member %qD", part); |
2518 | *non_constant_p = true; | |
2519 | return t; | |
2520 | } | |
2521 | ||
2d76680f PC |
2522 | /* If there's no explicit init for this field, it's value-initialized. */ |
2523 | value = build_value_init (TREE_TYPE (t), tf_warning_or_error); | |
3e605b20 | 2524 | return cxx_eval_constant_expression (ctx, value, |
92a596e8 | 2525 | lval, |
5a804683 | 2526 | non_constant_p, overflow_p); |
2d76680f PC |
2527 | } |
2528 | ||
2529 | /* Subroutine of cxx_eval_constant_expression. | |
2530 | Attempt to reduce a field access of a value of class type that is | |
2531 | expressed as a BIT_FIELD_REF. */ | |
2532 | ||
2533 | static tree | |
3e605b20 | 2534 | cxx_eval_bit_field_ref (const constexpr_ctx *ctx, tree t, |
92a596e8 | 2535 | bool lval, |
2d76680f PC |
2536 | bool *non_constant_p, bool *overflow_p) |
2537 | { | |
2538 | tree orig_whole = TREE_OPERAND (t, 0); | |
2539 | tree retval, fldval, utype, mask; | |
2540 | bool fld_seen = false; | |
2541 | HOST_WIDE_INT istart, isize; | |
3e605b20 | 2542 | tree whole = cxx_eval_constant_expression (ctx, orig_whole, |
92a596e8 | 2543 | lval, |
5a804683 | 2544 | non_constant_p, overflow_p); |
2d76680f PC |
2545 | tree start, field, value; |
2546 | unsigned HOST_WIDE_INT i; | |
2547 | ||
2548 | if (whole == orig_whole) | |
2549 | return t; | |
2550 | /* Don't VERIFY_CONSTANT here; we only want to check that we got a | |
2551 | CONSTRUCTOR. */ | |
2552 | if (!*non_constant_p | |
2553 | && TREE_CODE (whole) != VECTOR_CST | |
2554 | && TREE_CODE (whole) != CONSTRUCTOR) | |
2555 | { | |
2b3ab879 | 2556 | if (!ctx->quiet) |
2d76680f PC |
2557 | error ("%qE is not a constant expression", orig_whole); |
2558 | *non_constant_p = true; | |
2559 | } | |
2560 | if (*non_constant_p) | |
2561 | return t; | |
2562 | ||
2563 | if (TREE_CODE (whole) == VECTOR_CST) | |
2564 | return fold_ternary (BIT_FIELD_REF, TREE_TYPE (t), whole, | |
2565 | TREE_OPERAND (t, 1), TREE_OPERAND (t, 2)); | |
2566 | ||
2567 | start = TREE_OPERAND (t, 2); | |
2568 | istart = tree_to_shwi (start); | |
2569 | isize = tree_to_shwi (TREE_OPERAND (t, 1)); | |
2570 | utype = TREE_TYPE (t); | |
2571 | if (!TYPE_UNSIGNED (utype)) | |
2572 | utype = build_nonstandard_integer_type (TYPE_PRECISION (utype), 1); | |
2573 | retval = build_int_cst (utype, 0); | |
2574 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (whole), i, field, value) | |
2575 | { | |
2576 | tree bitpos = bit_position (field); | |
2577 | if (bitpos == start && DECL_SIZE (field) == TREE_OPERAND (t, 1)) | |
2578 | return value; | |
2579 | if (TREE_CODE (TREE_TYPE (field)) == INTEGER_TYPE | |
2580 | && TREE_CODE (value) == INTEGER_CST | |
2581 | && tree_fits_shwi_p (bitpos) | |
2582 | && tree_fits_shwi_p (DECL_SIZE (field))) | |
2583 | { | |
2584 | HOST_WIDE_INT bit = tree_to_shwi (bitpos); | |
2585 | HOST_WIDE_INT sz = tree_to_shwi (DECL_SIZE (field)); | |
2586 | HOST_WIDE_INT shift; | |
2587 | if (bit >= istart && bit + sz <= istart + isize) | |
2588 | { | |
2589 | fldval = fold_convert (utype, value); | |
2590 | mask = build_int_cst_type (utype, -1); | |
2591 | mask = fold_build2 (LSHIFT_EXPR, utype, mask, | |
2592 | size_int (TYPE_PRECISION (utype) - sz)); | |
2593 | mask = fold_build2 (RSHIFT_EXPR, utype, mask, | |
2594 | size_int (TYPE_PRECISION (utype) - sz)); | |
2595 | fldval = fold_build2 (BIT_AND_EXPR, utype, fldval, mask); | |
2596 | shift = bit - istart; | |
2597 | if (BYTES_BIG_ENDIAN) | |
2598 | shift = TYPE_PRECISION (utype) - shift - sz; | |
2599 | fldval = fold_build2 (LSHIFT_EXPR, utype, fldval, | |
2600 | size_int (shift)); | |
2601 | retval = fold_build2 (BIT_IOR_EXPR, utype, retval, fldval); | |
2602 | fld_seen = true; | |
2603 | } | |
2604 | } | |
2605 | } | |
2606 | if (fld_seen) | |
2607 | return fold_convert (TREE_TYPE (t), retval); | |
2608 | gcc_unreachable (); | |
2609 | return error_mark_node; | |
2610 | } | |
2611 | ||
2612 | /* Subroutine of cxx_eval_constant_expression. | |
2613 | Evaluate a short-circuited logical expression T in the context | |
2614 | of a given constexpr CALL. BAILOUT_VALUE is the value for | |
2615 | early return. CONTINUE_VALUE is used here purely for | |
2616 | sanity check purposes. */ | |
2617 | ||
2618 | static tree | |
3e605b20 | 2619 | cxx_eval_logical_expression (const constexpr_ctx *ctx, tree t, |
2d76680f | 2620 | tree bailout_value, tree continue_value, |
92a596e8 | 2621 | bool lval, |
2d76680f PC |
2622 | bool *non_constant_p, bool *overflow_p) |
2623 | { | |
2624 | tree r; | |
3e605b20 | 2625 | tree lhs = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), |
92a596e8 | 2626 | lval, |
5a804683 | 2627 | non_constant_p, overflow_p); |
2d76680f PC |
2628 | VERIFY_CONSTANT (lhs); |
2629 | if (tree_int_cst_equal (lhs, bailout_value)) | |
2630 | return lhs; | |
2631 | gcc_assert (tree_int_cst_equal (lhs, continue_value)); | |
3e605b20 | 2632 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), |
92a596e8 | 2633 | lval, non_constant_p, |
5a804683 | 2634 | overflow_p); |
2d76680f PC |
2635 | VERIFY_CONSTANT (r); |
2636 | return r; | |
2637 | } | |
2638 | ||
2639 | /* REF is a COMPONENT_REF designating a particular field. V is a vector of | |
2640 | CONSTRUCTOR elements to initialize (part of) an object containing that | |
2641 | field. Return a pointer to the constructor_elt corresponding to the | |
2642 | initialization of the field. */ | |
2643 | ||
2644 | static constructor_elt * | |
2645 | base_field_constructor_elt (vec<constructor_elt, va_gc> *v, tree ref) | |
2646 | { | |
2647 | tree aggr = TREE_OPERAND (ref, 0); | |
2648 | tree field = TREE_OPERAND (ref, 1); | |
2649 | HOST_WIDE_INT i; | |
2650 | constructor_elt *ce; | |
2651 | ||
2652 | gcc_assert (TREE_CODE (ref) == COMPONENT_REF); | |
2653 | ||
2654 | if (TREE_CODE (aggr) == COMPONENT_REF) | |
2655 | { | |
2656 | constructor_elt *base_ce | |
2657 | = base_field_constructor_elt (v, aggr); | |
2658 | v = CONSTRUCTOR_ELTS (base_ce->value); | |
2659 | } | |
2660 | ||
2661 | for (i = 0; vec_safe_iterate (v, i, &ce); ++i) | |
2662 | if (ce->index == field) | |
2663 | return ce; | |
2664 | ||
2665 | gcc_unreachable (); | |
2666 | return NULL; | |
2667 | } | |
2668 | ||
3e605b20 JM |
2669 | /* Some of the expressions fed to the constexpr mechanism are calls to |
2670 | constructors, which have type void. In that case, return the type being | |
2671 | initialized by the constructor. */ | |
2672 | ||
2673 | static tree | |
2674 | initialized_type (tree t) | |
2675 | { | |
2676 | if (TYPE_P (t)) | |
2677 | return t; | |
2678 | tree type = cv_unqualified (TREE_TYPE (t)); | |
2679 | if (TREE_CODE (t) == CALL_EXPR || TREE_CODE (t) == AGGR_INIT_EXPR) | |
2680 | { | |
2681 | /* A constructor call has void type, so we need to look deeper. */ | |
2682 | tree fn = get_function_named_in_call (t); | |
2683 | if (fn && TREE_CODE (fn) == FUNCTION_DECL | |
2684 | && DECL_CXX_CONSTRUCTOR_P (fn)) | |
2685 | type = DECL_CONTEXT (fn); | |
2686 | } | |
2687 | return type; | |
2688 | } | |
2689 | ||
2690 | /* We're about to initialize element INDEX of an array or class from VALUE. | |
2691 | Set up NEW_CTX appropriately by adjusting .object to refer to the | |
2692 | subobject and creating a new CONSTRUCTOR if the element is itself | |
2693 | a class or array. */ | |
2694 | ||
2695 | static void | |
2696 | init_subob_ctx (const constexpr_ctx *ctx, constexpr_ctx &new_ctx, | |
2697 | tree index, tree &value) | |
2698 | { | |
2699 | new_ctx = *ctx; | |
2700 | ||
2701 | if (index && TREE_CODE (index) != INTEGER_CST | |
2702 | && TREE_CODE (index) != FIELD_DECL) | |
2703 | /* This won't have an element in the new CONSTRUCTOR. */ | |
2704 | return; | |
2705 | ||
2706 | tree type = initialized_type (value); | |
2707 | if (!AGGREGATE_TYPE_P (type) && !VECTOR_TYPE_P (type)) | |
2708 | /* A non-aggregate member doesn't get its own CONSTRUCTOR. */ | |
2709 | return; | |
2710 | ||
2711 | /* The sub-aggregate initializer might contain a placeholder; | |
2712 | update object to refer to the subobject and ctor to refer to | |
2713 | the (newly created) sub-initializer. */ | |
2714 | if (ctx->object) | |
2715 | new_ctx.object = build_ctor_subob_ref (index, type, ctx->object); | |
2716 | tree elt = build_constructor (type, NULL); | |
2717 | CONSTRUCTOR_NO_IMPLICIT_ZERO (elt) = true; | |
2718 | new_ctx.ctor = elt; | |
2719 | ||
2720 | if (TREE_CODE (value) == TARGET_EXPR) | |
2721 | /* Avoid creating another CONSTRUCTOR when we expand the TARGET_EXPR. */ | |
2722 | value = TARGET_EXPR_INITIAL (value); | |
2723 | } | |
2724 | ||
2725 | /* We're about to process an initializer for a class or array TYPE. Make | |
2726 | sure that CTX is set up appropriately. */ | |
2727 | ||
2728 | static void | |
2729 | verify_ctor_sanity (const constexpr_ctx *ctx, tree type) | |
2730 | { | |
2731 | /* We don't bother building a ctor for an empty base subobject. */ | |
2732 | if (is_empty_class (type)) | |
2733 | return; | |
2734 | ||
2735 | /* We're in the middle of an initializer that might involve placeholders; | |
2736 | our caller should have created a CONSTRUCTOR for us to put the | |
2737 | initializer into. We will either return that constructor or T. */ | |
2738 | gcc_assert (ctx->ctor); | |
2739 | gcc_assert (same_type_ignoring_top_level_qualifiers_p | |
2740 | (type, TREE_TYPE (ctx->ctor))); | |
fe69277d JM |
2741 | /* We used to check that ctx->ctor was empty, but that isn't the case when |
2742 | the object is zero-initialized before calling the constructor. */ | |
3e605b20 | 2743 | if (ctx->object) |
176e79b5 JM |
2744 | { |
2745 | tree otype = TREE_TYPE (ctx->object); | |
2746 | gcc_assert (same_type_ignoring_top_level_qualifiers_p (type, otype) | |
2747 | /* Handle flexible array members. */ | |
2748 | || (TREE_CODE (otype) == ARRAY_TYPE | |
2749 | && TYPE_DOMAIN (otype) == NULL_TREE | |
2750 | && TREE_CODE (type) == ARRAY_TYPE | |
2751 | && (same_type_ignoring_top_level_qualifiers_p | |
2752 | (TREE_TYPE (type), TREE_TYPE (otype))))); | |
2753 | } | |
3e605b20 JM |
2754 | gcc_assert (!ctx->object || !DECL_P (ctx->object) |
2755 | || *(ctx->values->get (ctx->object)) == ctx->ctor); | |
2756 | } | |
2757 | ||
2d76680f PC |
2758 | /* Subroutine of cxx_eval_constant_expression. |
2759 | The expression tree T denotes a C-style array or a C-style | |
2760 | aggregate. Reduce it to a constant expression. */ | |
2761 | ||
2762 | static tree | |
3e605b20 | 2763 | cxx_eval_bare_aggregate (const constexpr_ctx *ctx, tree t, |
92a596e8 | 2764 | bool lval, |
2d76680f PC |
2765 | bool *non_constant_p, bool *overflow_p) |
2766 | { | |
2767 | vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (t); | |
2d76680f PC |
2768 | bool changed = false; |
2769 | gcc_assert (!BRACE_ENCLOSED_INITIALIZER_P (t)); | |
8a29084d | 2770 | tree type = TREE_TYPE (t); |
3e605b20 | 2771 | |
8a29084d | 2772 | constexpr_ctx new_ctx; |
d4619dc1 | 2773 | if (TYPE_PTRMEMFUNC_P (type) || VECTOR_TYPE_P (type)) |
8a29084d | 2774 | { |
d4619dc1 NS |
2775 | /* We don't really need the ctx->ctor business for a PMF or |
2776 | vector, but it's simpler to use the same code. */ | |
8a29084d JM |
2777 | new_ctx = *ctx; |
2778 | new_ctx.ctor = build_constructor (type, NULL); | |
2779 | new_ctx.object = NULL_TREE; | |
2780 | ctx = &new_ctx; | |
2781 | }; | |
2782 | verify_ctor_sanity (ctx, type); | |
3e605b20 JM |
2783 | vec<constructor_elt, va_gc> **p = &CONSTRUCTOR_ELTS (ctx->ctor); |
2784 | vec_alloc (*p, vec_safe_length (v)); | |
2785 | ||
2d63bc39 JM |
2786 | unsigned i; |
2787 | tree index, value; | |
2788 | bool constant_p = true; | |
2789 | bool side_effects_p = false; | |
3e605b20 | 2790 | FOR_EACH_CONSTRUCTOR_ELT (v, i, index, value) |
2d76680f | 2791 | { |
bcb5f3c9 | 2792 | tree orig_value = value; |
3e605b20 JM |
2793 | init_subob_ctx (ctx, new_ctx, index, value); |
2794 | if (new_ctx.ctor != ctx->ctor) | |
2795 | /* If we built a new CONSTRUCTOR, attach it now so that other | |
2796 | initializers can refer to it. */ | |
2797 | CONSTRUCTOR_APPEND_ELT (*p, index, new_ctx.ctor); | |
2798 | tree elt = cxx_eval_constant_expression (&new_ctx, value, | |
92a596e8 | 2799 | lval, |
5a804683 | 2800 | non_constant_p, overflow_p); |
2d76680f | 2801 | /* Don't VERIFY_CONSTANT here. */ |
2b3ab879 | 2802 | if (ctx->quiet && *non_constant_p) |
3e605b20 | 2803 | break; |
bcb5f3c9 | 2804 | if (elt != orig_value) |
2d76680f | 2805 | changed = true; |
2d63bc39 JM |
2806 | |
2807 | if (!TREE_CONSTANT (elt)) | |
2808 | constant_p = false; | |
2809 | if (TREE_SIDE_EFFECTS (elt)) | |
2810 | side_effects_p = true; | |
3e605b20 | 2811 | if (index && TREE_CODE (index) == COMPONENT_REF) |
2d76680f PC |
2812 | { |
2813 | /* This is an initialization of a vfield inside a base | |
2814 | subaggregate that we already initialized; push this | |
2815 | initialization into the previous initialization. */ | |
3e605b20 | 2816 | constructor_elt *inner = base_field_constructor_elt (*p, index); |
2d76680f | 2817 | inner->value = elt; |
3e605b20 | 2818 | changed = true; |
2d76680f | 2819 | } |
3e605b20 JM |
2820 | else if (index |
2821 | && (TREE_CODE (index) == NOP_EXPR | |
2822 | || TREE_CODE (index) == POINTER_PLUS_EXPR)) | |
2d76680f PC |
2823 | { |
2824 | /* This is an initializer for an empty base; now that we've | |
2825 | checked that it's constant, we can ignore it. */ | |
3e605b20 JM |
2826 | gcc_assert (is_empty_class (TREE_TYPE (TREE_TYPE (index)))); |
2827 | changed = true; | |
2828 | } | |
2829 | else if (new_ctx.ctor != ctx->ctor) | |
2830 | { | |
2831 | /* We appended this element above; update the value. */ | |
2832 | gcc_assert ((*p)->last().index == index); | |
2833 | (*p)->last().value = elt; | |
2d76680f PC |
2834 | } |
2835 | else | |
3e605b20 | 2836 | CONSTRUCTOR_APPEND_ELT (*p, index, elt); |
2d76680f PC |
2837 | } |
2838 | if (*non_constant_p || !changed) | |
3e605b20 JM |
2839 | return t; |
2840 | t = ctx->ctor; | |
2841 | /* We're done building this CONSTRUCTOR, so now we can interpret an | |
2842 | element without an explicit initializer as value-initialized. */ | |
2843 | CONSTRUCTOR_NO_IMPLICIT_ZERO (t) = false; | |
2d63bc39 JM |
2844 | TREE_CONSTANT (t) = constant_p; |
2845 | TREE_SIDE_EFFECTS (t) = side_effects_p; | |
8a29084d | 2846 | if (VECTOR_TYPE_P (type)) |
2d76680f PC |
2847 | t = fold (t); |
2848 | return t; | |
2849 | } | |
2850 | ||
2851 | /* Subroutine of cxx_eval_constant_expression. | |
2852 | The expression tree T is a VEC_INIT_EXPR which denotes the desired | |
2853 | initialization of a non-static data member of array type. Reduce it to a | |
2854 | CONSTRUCTOR. | |
2855 | ||
2856 | Note that apart from value-initialization (when VALUE_INIT is true), | |
2857 | this is only intended to support value-initialization and the | |
2858 | initializations done by defaulted constructors for classes with | |
2859 | non-static data members of array type. In this case, VEC_INIT_EXPR_INIT | |
2860 | will either be NULL_TREE for the default constructor, or a COMPONENT_REF | |
2861 | for the copy/move constructor. */ | |
2862 | ||
2863 | static tree | |
3e605b20 | 2864 | cxx_eval_vec_init_1 (const constexpr_ctx *ctx, tree atype, tree init, |
92a596e8 | 2865 | bool value_init, bool lval, |
2d76680f PC |
2866 | bool *non_constant_p, bool *overflow_p) |
2867 | { | |
2868 | tree elttype = TREE_TYPE (atype); | |
4784470a | 2869 | unsigned HOST_WIDE_INT max = tree_to_uhwi (array_type_nelts_top (atype)); |
3e605b20 JM |
2870 | verify_ctor_sanity (ctx, atype); |
2871 | vec<constructor_elt, va_gc> **p = &CONSTRUCTOR_ELTS (ctx->ctor); | |
2872 | vec_alloc (*p, max + 1); | |
2d76680f | 2873 | bool pre_init = false; |
4784470a | 2874 | unsigned HOST_WIDE_INT i; |
2d76680f PC |
2875 | |
2876 | /* For the default constructor, build up a call to the default | |
2877 | constructor of the element type. We only need to handle class types | |
2878 | here, as for a constructor to be constexpr, all members must be | |
2879 | initialized, which for a defaulted default constructor means they must | |
2880 | be of a class type with a constexpr default constructor. */ | |
2881 | if (TREE_CODE (elttype) == ARRAY_TYPE) | |
2882 | /* We only do this at the lowest level. */; | |
2883 | else if (value_init) | |
2884 | { | |
2885 | init = build_value_init (elttype, tf_warning_or_error); | |
2d76680f PC |
2886 | pre_init = true; |
2887 | } | |
2888 | else if (!init) | |
2889 | { | |
2890 | vec<tree, va_gc> *argvec = make_tree_vector (); | |
2891 | init = build_special_member_call (NULL_TREE, complete_ctor_identifier, | |
2892 | &argvec, elttype, LOOKUP_NORMAL, | |
2893 | tf_warning_or_error); | |
2894 | release_tree_vector (argvec); | |
60813a46 | 2895 | init = build_aggr_init_expr (TREE_TYPE (init), init); |
2d76680f PC |
2896 | pre_init = true; |
2897 | } | |
2898 | ||
4784470a | 2899 | for (i = 0; i < max; ++i) |
2d76680f PC |
2900 | { |
2901 | tree idx = build_int_cst (size_type_node, i); | |
2902 | tree eltinit; | |
928af3bf | 2903 | bool reuse = false; |
3e605b20 JM |
2904 | constexpr_ctx new_ctx; |
2905 | init_subob_ctx (ctx, new_ctx, idx, pre_init ? init : elttype); | |
2906 | if (new_ctx.ctor != ctx->ctor) | |
2907 | CONSTRUCTOR_APPEND_ELT (*p, idx, new_ctx.ctor); | |
2d76680f PC |
2908 | if (TREE_CODE (elttype) == ARRAY_TYPE) |
2909 | { | |
2910 | /* A multidimensional array; recurse. */ | |
2911 | if (value_init || init == NULL_TREE) | |
928af3bf JJ |
2912 | { |
2913 | eltinit = NULL_TREE; | |
2914 | reuse = i == 0; | |
2915 | } | |
2d76680f PC |
2916 | else |
2917 | eltinit = cp_build_array_ref (input_location, init, idx, | |
2918 | tf_warning_or_error); | |
3e605b20 | 2919 | eltinit = cxx_eval_vec_init_1 (&new_ctx, elttype, eltinit, value_init, |
92a596e8 | 2920 | lval, |
2d76680f PC |
2921 | non_constant_p, overflow_p); |
2922 | } | |
2923 | else if (pre_init) | |
2924 | { | |
2925 | /* Initializing an element using value or default initialization | |
2926 | we just pre-built above. */ | |
928af3bf JJ |
2927 | eltinit = cxx_eval_constant_expression (&new_ctx, init, lval, |
2928 | non_constant_p, overflow_p); | |
2929 | reuse = i == 0; | |
2d76680f PC |
2930 | } |
2931 | else | |
2932 | { | |
2933 | /* Copying an element. */ | |
2934 | gcc_assert (same_type_ignoring_top_level_qualifiers_p | |
2935 | (atype, TREE_TYPE (init))); | |
2936 | eltinit = cp_build_array_ref (input_location, init, idx, | |
2937 | tf_warning_or_error); | |
72b3e203 | 2938 | if (!lvalue_p (init)) |
2d76680f PC |
2939 | eltinit = move (eltinit); |
2940 | eltinit = force_rvalue (eltinit, tf_warning_or_error); | |
3e605b20 | 2941 | eltinit = (cxx_eval_constant_expression |
92a596e8 | 2942 | (&new_ctx, eltinit, lval, |
5a804683 | 2943 | non_constant_p, overflow_p)); |
2d76680f | 2944 | } |
2b3ab879 | 2945 | if (*non_constant_p && !ctx->quiet) |
3e605b20 JM |
2946 | break; |
2947 | if (new_ctx.ctor != ctx->ctor) | |
2948 | { | |
2949 | /* We appended this element above; update the value. */ | |
2950 | gcc_assert ((*p)->last().index == idx); | |
2951 | (*p)->last().value = eltinit; | |
2952 | } | |
2953 | else | |
2954 | CONSTRUCTOR_APPEND_ELT (*p, idx, eltinit); | |
928af3bf JJ |
2955 | /* Reuse the result of cxx_eval_constant_expression call |
2956 | from the first iteration to all others if it is a constant | |
2957 | initializer that doesn't require relocations. */ | |
2958 | if (reuse | |
2959 | && max > 1 | |
2960 | && (initializer_constant_valid_p (eltinit, TREE_TYPE (eltinit)) | |
2961 | == null_pointer_node)) | |
2962 | { | |
2963 | if (new_ctx.ctor != ctx->ctor) | |
2964 | eltinit = new_ctx.ctor; | |
2965 | for (i = 1; i < max; ++i) | |
2966 | { | |
2967 | idx = build_int_cst (size_type_node, i); | |
0146e25f | 2968 | CONSTRUCTOR_APPEND_ELT (*p, idx, unshare_constructor (eltinit)); |
928af3bf JJ |
2969 | } |
2970 | break; | |
2971 | } | |
2d76680f PC |
2972 | } |
2973 | ||
2974 | if (!*non_constant_p) | |
2975 | { | |
3e605b20 JM |
2976 | init = ctx->ctor; |
2977 | CONSTRUCTOR_NO_IMPLICIT_ZERO (init) = false; | |
2d76680f | 2978 | } |
2d76680f PC |
2979 | return init; |
2980 | } | |
2981 | ||
2982 | static tree | |
3e605b20 | 2983 | cxx_eval_vec_init (const constexpr_ctx *ctx, tree t, |
92a596e8 | 2984 | bool lval, |
2d76680f PC |
2985 | bool *non_constant_p, bool *overflow_p) |
2986 | { | |
2987 | tree atype = TREE_TYPE (t); | |
2988 | tree init = VEC_INIT_EXPR_INIT (t); | |
3e605b20 | 2989 | tree r = cxx_eval_vec_init_1 (ctx, atype, init, |
2d76680f | 2990 | VEC_INIT_EXPR_VALUE_INIT (t), |
92a596e8 | 2991 | lval, non_constant_p, overflow_p); |
2d76680f PC |
2992 | if (*non_constant_p) |
2993 | return t; | |
2994 | else | |
2995 | return r; | |
2996 | } | |
2997 | ||
2998 | /* A less strict version of fold_indirect_ref_1, which requires cv-quals to | |
2999 | match. We want to be less strict for simple *& folding; if we have a | |
3000 | non-const temporary that we access through a const pointer, that should | |
3001 | work. We handle this here rather than change fold_indirect_ref_1 | |
3002 | because we're dealing with things like ADDR_EXPR of INTEGER_CST which | |
3003 | don't really make sense outside of constant expression evaluation. Also | |
3004 | we want to allow folding to COMPONENT_REF, which could cause trouble | |
3005 | with TBAA in fold_indirect_ref_1. | |
3006 | ||
3007 | Try to keep this function synced with fold_indirect_ref_1. */ | |
3008 | ||
3009 | static tree | |
3010 | cxx_fold_indirect_ref (location_t loc, tree type, tree op0, bool *empty_base) | |
3011 | { | |
3012 | tree sub, subtype; | |
3013 | ||
3014 | sub = op0; | |
3015 | STRIP_NOPS (sub); | |
3016 | subtype = TREE_TYPE (sub); | |
3017 | if (!POINTER_TYPE_P (subtype)) | |
3018 | return NULL_TREE; | |
3019 | ||
3020 | if (TREE_CODE (sub) == ADDR_EXPR) | |
3021 | { | |
3022 | tree op = TREE_OPERAND (sub, 0); | |
3023 | tree optype = TREE_TYPE (op); | |
3024 | ||
3025 | /* *&CONST_DECL -> to the value of the const decl. */ | |
3026 | if (TREE_CODE (op) == CONST_DECL) | |
3027 | return DECL_INITIAL (op); | |
3028 | /* *&p => p; make sure to handle *&"str"[cst] here. */ | |
fe71aa4e JM |
3029 | if (same_type_ignoring_top_level_qualifiers_p (optype, type) |
3030 | /* Also handle the case where the desired type is an array of unknown | |
3031 | bounds because the variable has had its bounds deduced since the | |
3032 | ADDR_EXPR was created. */ | |
3033 | || (TREE_CODE (type) == ARRAY_TYPE | |
3034 | && TREE_CODE (optype) == ARRAY_TYPE | |
3035 | && TYPE_DOMAIN (type) == NULL_TREE | |
3036 | && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (optype), | |
3037 | TREE_TYPE (type)))) | |
2d76680f PC |
3038 | { |
3039 | tree fop = fold_read_from_constant_string (op); | |
3040 | if (fop) | |
3041 | return fop; | |
3042 | else | |
3043 | return op; | |
3044 | } | |
3045 | /* *(foo *)&fooarray => fooarray[0] */ | |
3046 | else if (TREE_CODE (optype) == ARRAY_TYPE | |
3047 | && (same_type_ignoring_top_level_qualifiers_p | |
3048 | (type, TREE_TYPE (optype)))) | |
3049 | { | |
3050 | tree type_domain = TYPE_DOMAIN (optype); | |
3051 | tree min_val = size_zero_node; | |
3052 | if (type_domain && TYPE_MIN_VALUE (type_domain)) | |
3053 | min_val = TYPE_MIN_VALUE (type_domain); | |
3054 | return build4_loc (loc, ARRAY_REF, type, op, min_val, | |
3055 | NULL_TREE, NULL_TREE); | |
3056 | } | |
3057 | /* *(foo *)&complexfoo => __real__ complexfoo */ | |
3058 | else if (TREE_CODE (optype) == COMPLEX_TYPE | |
3059 | && (same_type_ignoring_top_level_qualifiers_p | |
3060 | (type, TREE_TYPE (optype)))) | |
3061 | return fold_build1_loc (loc, REALPART_EXPR, type, op); | |
3062 | /* *(foo *)&vectorfoo => BIT_FIELD_REF<vectorfoo,...> */ | |
b55b02ea | 3063 | else if (VECTOR_TYPE_P (optype) |
2d76680f PC |
3064 | && (same_type_ignoring_top_level_qualifiers_p |
3065 | (type, TREE_TYPE (optype)))) | |
3066 | { | |
3067 | tree part_width = TYPE_SIZE (type); | |
3068 | tree index = bitsize_int (0); | |
3069 | return fold_build3_loc (loc, BIT_FIELD_REF, type, op, part_width, index); | |
3070 | } | |
3071 | /* Also handle conversion to an empty base class, which | |
3072 | is represented with a NOP_EXPR. */ | |
3073 | else if (is_empty_class (type) | |
3074 | && CLASS_TYPE_P (optype) | |
3075 | && DERIVED_FROM_P (type, optype)) | |
3076 | { | |
3077 | *empty_base = true; | |
3078 | return op; | |
3079 | } | |
3080 | /* *(foo *)&struct_with_foo_field => COMPONENT_REF */ | |
3081 | else if (RECORD_OR_UNION_TYPE_P (optype)) | |
3082 | { | |
3083 | tree field = TYPE_FIELDS (optype); | |
3084 | for (; field; field = DECL_CHAIN (field)) | |
3085 | if (TREE_CODE (field) == FIELD_DECL | |
b912f962 | 3086 | && TREE_TYPE (field) != error_mark_node |
2d76680f PC |
3087 | && integer_zerop (byte_position (field)) |
3088 | && (same_type_ignoring_top_level_qualifiers_p | |
3089 | (TREE_TYPE (field), type))) | |
b912f962 | 3090 | return fold_build3 (COMPONENT_REF, type, op, field, NULL_TREE); |
2d76680f PC |
3091 | } |
3092 | } | |
3093 | else if (TREE_CODE (sub) == POINTER_PLUS_EXPR | |
3094 | && TREE_CODE (TREE_OPERAND (sub, 1)) == INTEGER_CST) | |
3095 | { | |
3096 | tree op00 = TREE_OPERAND (sub, 0); | |
3097 | tree op01 = TREE_OPERAND (sub, 1); | |
3098 | ||
3099 | STRIP_NOPS (op00); | |
3100 | if (TREE_CODE (op00) == ADDR_EXPR) | |
3101 | { | |
3102 | tree op00type; | |
3103 | op00 = TREE_OPERAND (op00, 0); | |
3104 | op00type = TREE_TYPE (op00); | |
3105 | ||
3106 | /* ((foo*)&vectorfoo)[1] => BIT_FIELD_REF<vectorfoo,...> */ | |
b55b02ea | 3107 | if (VECTOR_TYPE_P (op00type) |
2d76680f PC |
3108 | && (same_type_ignoring_top_level_qualifiers_p |
3109 | (type, TREE_TYPE (op00type)))) | |
3110 | { | |
3111 | HOST_WIDE_INT offset = tree_to_shwi (op01); | |
3112 | tree part_width = TYPE_SIZE (type); | |
3113 | unsigned HOST_WIDE_INT part_widthi = tree_to_shwi (part_width)/BITS_PER_UNIT; | |
3114 | unsigned HOST_WIDE_INT indexi = offset * BITS_PER_UNIT; | |
3115 | tree index = bitsize_int (indexi); | |
3116 | ||
3117 | if (offset / part_widthi < TYPE_VECTOR_SUBPARTS (op00type)) | |
3118 | return fold_build3_loc (loc, | |
3119 | BIT_FIELD_REF, type, op00, | |
3120 | part_width, index); | |
3121 | ||
3122 | } | |
3123 | /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */ | |
3124 | else if (TREE_CODE (op00type) == COMPLEX_TYPE | |
3125 | && (same_type_ignoring_top_level_qualifiers_p | |
3126 | (type, TREE_TYPE (op00type)))) | |
3127 | { | |
3128 | tree size = TYPE_SIZE_UNIT (type); | |
3129 | if (tree_int_cst_equal (size, op01)) | |
3130 | return fold_build1_loc (loc, IMAGPART_EXPR, type, op00); | |
3131 | } | |
3132 | /* ((foo *)&fooarray)[1] => fooarray[1] */ | |
3133 | else if (TREE_CODE (op00type) == ARRAY_TYPE | |
3134 | && (same_type_ignoring_top_level_qualifiers_p | |
3135 | (type, TREE_TYPE (op00type)))) | |
3136 | { | |
3137 | tree type_domain = TYPE_DOMAIN (op00type); | |
3138 | tree min_val = size_zero_node; | |
3139 | if (type_domain && TYPE_MIN_VALUE (type_domain)) | |
3140 | min_val = TYPE_MIN_VALUE (type_domain); | |
3141 | op01 = size_binop_loc (loc, EXACT_DIV_EXPR, op01, | |
3142 | TYPE_SIZE_UNIT (type)); | |
3143 | op01 = size_binop_loc (loc, PLUS_EXPR, op01, min_val); | |
3144 | return build4_loc (loc, ARRAY_REF, type, op00, op01, | |
3145 | NULL_TREE, NULL_TREE); | |
3146 | } | |
3147 | /* Also handle conversion to an empty base class, which | |
3148 | is represented with a NOP_EXPR. */ | |
3149 | else if (is_empty_class (type) | |
3150 | && CLASS_TYPE_P (op00type) | |
3151 | && DERIVED_FROM_P (type, op00type)) | |
3152 | { | |
3153 | *empty_base = true; | |
3154 | return op00; | |
3155 | } | |
3156 | /* ((foo *)&struct_with_foo_field)[1] => COMPONENT_REF */ | |
3157 | else if (RECORD_OR_UNION_TYPE_P (op00type)) | |
3158 | { | |
3159 | tree field = TYPE_FIELDS (op00type); | |
3160 | for (; field; field = DECL_CHAIN (field)) | |
3161 | if (TREE_CODE (field) == FIELD_DECL | |
b912f962 | 3162 | && TREE_TYPE (field) != error_mark_node |
2d76680f PC |
3163 | && tree_int_cst_equal (byte_position (field), op01) |
3164 | && (same_type_ignoring_top_level_qualifiers_p | |
3165 | (TREE_TYPE (field), type))) | |
b912f962 JJ |
3166 | return fold_build3 (COMPONENT_REF, type, op00, |
3167 | field, NULL_TREE); | |
2d76680f PC |
3168 | } |
3169 | } | |
3170 | } | |
3171 | /* *(foo *)fooarrptr => (*fooarrptr)[0] */ | |
3172 | else if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE | |
3173 | && (same_type_ignoring_top_level_qualifiers_p | |
3174 | (type, TREE_TYPE (TREE_TYPE (subtype))))) | |
3175 | { | |
3176 | tree type_domain; | |
3177 | tree min_val = size_zero_node; | |
3178 | tree newsub = cxx_fold_indirect_ref (loc, TREE_TYPE (subtype), sub, NULL); | |
3179 | if (newsub) | |
3180 | sub = newsub; | |
3181 | else | |
3182 | sub = build1_loc (loc, INDIRECT_REF, TREE_TYPE (subtype), sub); | |
3183 | type_domain = TYPE_DOMAIN (TREE_TYPE (sub)); | |
3184 | if (type_domain && TYPE_MIN_VALUE (type_domain)) | |
3185 | min_val = TYPE_MIN_VALUE (type_domain); | |
3186 | return build4_loc (loc, ARRAY_REF, type, sub, min_val, NULL_TREE, | |
3187 | NULL_TREE); | |
3188 | } | |
3189 | ||
3190 | return NULL_TREE; | |
3191 | } | |
3192 | ||
3193 | static tree | |
3e605b20 | 3194 | cxx_eval_indirect_ref (const constexpr_ctx *ctx, tree t, |
92a596e8 | 3195 | bool lval, |
2d76680f PC |
3196 | bool *non_constant_p, bool *overflow_p) |
3197 | { | |
3198 | tree orig_op0 = TREE_OPERAND (t, 0); | |
2d76680f | 3199 | bool empty_base = false; |
2d76680f | 3200 | |
cda0a029 JM |
3201 | /* We can handle a MEM_REF like an INDIRECT_REF, if MEM_REF's second |
3202 | operand is an integer-zero. Otherwise reject the MEM_REF for now. */ | |
3203 | ||
3204 | if (TREE_CODE (t) == MEM_REF | |
3205 | && (!TREE_OPERAND (t, 1) || !integer_zerop (TREE_OPERAND (t, 1)))) | |
3206 | { | |
3207 | gcc_assert (ctx->quiet); | |
3208 | *non_constant_p = true; | |
3209 | return t; | |
3210 | } | |
3211 | ||
255a48d6 JM |
3212 | /* First try to simplify it directly. */ |
3213 | tree r = cxx_fold_indirect_ref (EXPR_LOCATION (t), TREE_TYPE (t), orig_op0, | |
3214 | &empty_base); | |
3215 | if (!r) | |
2d76680f | 3216 | { |
255a48d6 JM |
3217 | /* If that didn't work, evaluate the operand first. */ |
3218 | tree op0 = cxx_eval_constant_expression (ctx, orig_op0, | |
3219 | /*lval*/false, non_constant_p, | |
3220 | overflow_p); | |
3221 | /* Don't VERIFY_CONSTANT here. */ | |
3222 | if (*non_constant_p) | |
3223 | return t; | |
3224 | ||
8bada5cd MS |
3225 | if (!lval && integer_zerop (op0)) |
3226 | { | |
3227 | if (!ctx->quiet) | |
3228 | error ("dereferencing a null pointer"); | |
3229 | *non_constant_p = true; | |
3230 | return t; | |
3231 | } | |
3232 | ||
255a48d6 JM |
3233 | r = cxx_fold_indirect_ref (EXPR_LOCATION (t), TREE_TYPE (t), op0, |
3234 | &empty_base); | |
3235 | if (r == NULL_TREE) | |
2d76680f PC |
3236 | { |
3237 | /* We couldn't fold to a constant value. Make sure it's not | |
3238 | something we should have been able to fold. */ | |
255a48d6 JM |
3239 | tree sub = op0; |
3240 | STRIP_NOPS (sub); | |
3241 | if (TREE_CODE (sub) == ADDR_EXPR) | |
3242 | { | |
3243 | gcc_assert (!same_type_ignoring_top_level_qualifiers_p | |
3244 | (TREE_TYPE (TREE_TYPE (sub)), TREE_TYPE (t))); | |
3245 | /* DR 1188 says we don't have to deal with this. */ | |
3246 | if (!ctx->quiet) | |
3247 | error ("accessing value of %qE through a %qT glvalue in a " | |
3248 | "constant expression", build_fold_indirect_ref (sub), | |
3249 | TREE_TYPE (t)); | |
3250 | *non_constant_p = true; | |
3251 | return t; | |
3252 | } | |
3253 | ||
3254 | if (lval && op0 != orig_op0) | |
3255 | return build1 (INDIRECT_REF, TREE_TYPE (t), op0); | |
3256 | if (!lval) | |
3257 | VERIFY_CONSTANT (t); | |
2d76680f PC |
3258 | return t; |
3259 | } | |
3260 | } | |
3261 | ||
255a48d6 JM |
3262 | r = cxx_eval_constant_expression (ctx, r, |
3263 | lval, non_constant_p, overflow_p); | |
3264 | if (*non_constant_p) | |
3265 | return t; | |
3266 | ||
125db6a1 | 3267 | /* If we're pulling out the value of an empty base, just return an empty |
2d76680f | 3268 | CONSTRUCTOR. */ |
92a596e8 | 3269 | if (empty_base && !lval) |
2d76680f | 3270 | { |
2d76680f PC |
3271 | r = build_constructor (TREE_TYPE (t), NULL); |
3272 | TREE_CONSTANT (r) = true; | |
3273 | } | |
3274 | ||
2d76680f PC |
3275 | return r; |
3276 | } | |
3277 | ||
3278 | /* Complain about R, a VAR_DECL, not being usable in a constant expression. | |
3279 | Shared between potential_constant_expression and | |
3280 | cxx_eval_constant_expression. */ | |
3281 | ||
3282 | static void | |
3283 | non_const_var_error (tree r) | |
3284 | { | |
3285 | tree type = TREE_TYPE (r); | |
3286 | error ("the value of %qD is not usable in a constant " | |
3287 | "expression", r); | |
3288 | /* Avoid error cascade. */ | |
3289 | if (DECL_INITIAL (r) == error_mark_node) | |
3290 | return; | |
3291 | if (DECL_DECLARED_CONSTEXPR_P (r)) | |
3292 | inform (DECL_SOURCE_LOCATION (r), | |
3293 | "%qD used in its own initializer", r); | |
3294 | else if (INTEGRAL_OR_ENUMERATION_TYPE_P (type)) | |
3295 | { | |
3296 | if (!CP_TYPE_CONST_P (type)) | |
3297 | inform (DECL_SOURCE_LOCATION (r), | |
3298 | "%q#D is not const", r); | |
3299 | else if (CP_TYPE_VOLATILE_P (type)) | |
3300 | inform (DECL_SOURCE_LOCATION (r), | |
3301 | "%q#D is volatile", r); | |
3302 | else if (!DECL_INITIAL (r) | |
a3e2b438 PP |
3303 | || !TREE_CONSTANT (DECL_INITIAL (r)) |
3304 | || !DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r)) | |
2d76680f PC |
3305 | inform (DECL_SOURCE_LOCATION (r), |
3306 | "%qD was not initialized with a constant " | |
3307 | "expression", r); | |
3308 | else | |
3309 | gcc_unreachable (); | |
3310 | } | |
fd338b13 JM |
3311 | else if (TREE_CODE (type) == REFERENCE_TYPE) |
3312 | inform (DECL_SOURCE_LOCATION (r), | |
3313 | "%qD was not initialized with a constant " | |
3314 | "expression", r); | |
2d76680f PC |
3315 | else |
3316 | { | |
3317 | if (cxx_dialect >= cxx11 && !DECL_DECLARED_CONSTEXPR_P (r)) | |
3318 | inform (DECL_SOURCE_LOCATION (r), | |
3319 | "%qD was not declared %<constexpr%>", r); | |
3320 | else | |
3321 | inform (DECL_SOURCE_LOCATION (r), | |
3322 | "%qD does not have integral or enumeration type", | |
3323 | r); | |
3324 | } | |
3325 | } | |
3326 | ||
3327 | /* Subroutine of cxx_eval_constant_expression. | |
3328 | Like cxx_eval_unary_expression, except for trinary expressions. */ | |
3329 | ||
3330 | static tree | |
3e605b20 | 3331 | cxx_eval_trinary_expression (const constexpr_ctx *ctx, tree t, |
92a596e8 | 3332 | bool lval, |
2d76680f PC |
3333 | bool *non_constant_p, bool *overflow_p) |
3334 | { | |
3335 | int i; | |
3336 | tree args[3]; | |
3337 | tree val; | |
3338 | ||
3339 | for (i = 0; i < 3; i++) | |
3340 | { | |
3e605b20 | 3341 | args[i] = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, i), |
92a596e8 | 3342 | lval, |
5a804683 | 3343 | non_constant_p, overflow_p); |
2d76680f PC |
3344 | VERIFY_CONSTANT (args[i]); |
3345 | } | |
3346 | ||
3347 | val = fold_ternary_loc (EXPR_LOCATION (t), TREE_CODE (t), TREE_TYPE (t), | |
3348 | args[0], args[1], args[2]); | |
3349 | if (val == NULL_TREE) | |
3350 | return t; | |
3351 | VERIFY_CONSTANT (val); | |
3352 | return val; | |
3353 | } | |
3354 | ||
98e5a19a JM |
3355 | /* True if T was declared in a function declared to be constexpr, and |
3356 | therefore potentially constant in C++14. */ | |
3357 | ||
2d76680f PC |
3358 | bool |
3359 | var_in_constexpr_fn (tree t) | |
3360 | { | |
3361 | tree ctx = DECL_CONTEXT (t); | |
98e5a19a | 3362 | return (ctx && TREE_CODE (ctx) == FUNCTION_DECL |
2d76680f PC |
3363 | && DECL_DECLARED_CONSTEXPR_P (ctx)); |
3364 | } | |
3365 | ||
98e5a19a JM |
3366 | /* True if T was declared in a function that might be constexpr: either a |
3367 | function that was declared constexpr, or a C++17 lambda op(). */ | |
3368 | ||
3369 | bool | |
3370 | var_in_maybe_constexpr_fn (tree t) | |
3371 | { | |
7b936140 | 3372 | if (cxx_dialect >= cxx17 |
98e5a19a JM |
3373 | && DECL_FUNCTION_SCOPE_P (t) |
3374 | && LAMBDA_FUNCTION_P (DECL_CONTEXT (t))) | |
3375 | return true; | |
3376 | return var_in_constexpr_fn (t); | |
3377 | } | |
3378 | ||
68d01920 JM |
3379 | /* We're assigning INIT to TARGET. In do_build_copy_constructor and |
3380 | build_over_call we implement trivial copy of a class with tail padding using | |
3381 | assignment of character arrays, which is valid in normal code, but not in | |
3382 | constexpr evaluation. We don't need to worry about clobbering tail padding | |
3383 | in constexpr evaluation, so strip the type punning. */ | |
3384 | ||
3385 | static void | |
3386 | maybe_simplify_trivial_copy (tree &target, tree &init) | |
3387 | { | |
3388 | if (TREE_CODE (target) == MEM_REF | |
3389 | && TREE_CODE (init) == MEM_REF | |
3390 | && TREE_TYPE (target) == TREE_TYPE (init) | |
3391 | && TREE_CODE (TREE_TYPE (target)) == ARRAY_TYPE | |
3392 | && TREE_TYPE (TREE_TYPE (target)) == unsigned_char_type_node) | |
3393 | { | |
3394 | target = build_fold_indirect_ref (TREE_OPERAND (target, 0)); | |
3395 | init = build_fold_indirect_ref (TREE_OPERAND (init, 0)); | |
3396 | } | |
3397 | } | |
3398 | ||
60813a46 JM |
3399 | /* Evaluate an INIT_EXPR or MODIFY_EXPR. */ |
3400 | ||
3401 | static tree | |
3402 | cxx_eval_store_expression (const constexpr_ctx *ctx, tree t, | |
92a596e8 | 3403 | bool lval, |
60813a46 JM |
3404 | bool *non_constant_p, bool *overflow_p) |
3405 | { | |
3406 | constexpr_ctx new_ctx = *ctx; | |
3407 | ||
58cc255c JM |
3408 | tree init = TREE_OPERAND (t, 1); |
3409 | if (TREE_CLOBBER_P (init)) | |
3410 | /* Just ignore clobbers. */ | |
3411 | return void_node; | |
3412 | ||
60813a46 JM |
3413 | /* First we figure out where we're storing to. */ |
3414 | tree target = TREE_OPERAND (t, 0); | |
68d01920 JM |
3415 | |
3416 | maybe_simplify_trivial_copy (target, init); | |
3417 | ||
3f8e2835 | 3418 | tree type = TREE_TYPE (target); |
60813a46 | 3419 | target = cxx_eval_constant_expression (ctx, target, |
2b3ab879 | 3420 | true, |
5a804683 | 3421 | non_constant_p, overflow_p); |
60813a46 JM |
3422 | if (*non_constant_p) |
3423 | return t; | |
3424 | ||
bc2a38df JJ |
3425 | /* cxx_eval_array_reference for lval = true allows references one past |
3426 | end of array, because it does not know if it is just taking address | |
3427 | (which is valid), or actual dereference. Here we know it is | |
3428 | a dereference, so diagnose it here. */ | |
3429 | for (tree probe = target; probe; ) | |
3430 | { | |
3431 | switch (TREE_CODE (probe)) | |
3432 | { | |
3433 | case ARRAY_REF: | |
3434 | tree nelts, ary; | |
3435 | ary = TREE_OPERAND (probe, 0); | |
3436 | if (TREE_CODE (TREE_TYPE (ary)) == ARRAY_TYPE) | |
3437 | nelts = array_type_nelts_top (TREE_TYPE (ary)); | |
3438 | else if (VECTOR_TYPE_P (TREE_TYPE (ary))) | |
3439 | nelts = size_int (TYPE_VECTOR_SUBPARTS (TREE_TYPE (ary))); | |
3440 | else | |
3441 | gcc_unreachable (); | |
3442 | nelts = cxx_eval_constant_expression (ctx, nelts, false, | |
3443 | non_constant_p, overflow_p); | |
3444 | VERIFY_CONSTANT (nelts); | |
3445 | gcc_assert (TREE_CODE (nelts) == INTEGER_CST | |
3446 | && TREE_CODE (TREE_OPERAND (probe, 1)) == INTEGER_CST); | |
a1488398 | 3447 | if (wi::to_widest (TREE_OPERAND (probe, 1)) == wi::to_widest (nelts)) |
bc2a38df JJ |
3448 | { |
3449 | diag_array_subscript (ctx, ary, TREE_OPERAND (probe, 1)); | |
3450 | *non_constant_p = true; | |
3451 | return t; | |
3452 | } | |
3453 | /* FALLTHRU */ | |
3454 | ||
3455 | case BIT_FIELD_REF: | |
3456 | case COMPONENT_REF: | |
3457 | probe = TREE_OPERAND (probe, 0); | |
3458 | continue; | |
3459 | ||
3460 | default: | |
3461 | probe = NULL_TREE; | |
3462 | continue; | |
3463 | } | |
3464 | } | |
3465 | ||
3f8e2835 JM |
3466 | if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (target), type)) |
3467 | { | |
3468 | /* For initialization of an empty base, the original target will be | |
3469 | *(base*)this, which the above evaluation resolves to the object | |
3470 | argument, which has the derived type rather than the base type. In | |
3471 | this situation, just evaluate the initializer and return, since | |
3472 | there's no actual data to store. */ | |
3473 | gcc_assert (is_empty_class (type)); | |
3474 | return cxx_eval_constant_expression (ctx, init, false, | |
3475 | non_constant_p, overflow_p); | |
3476 | } | |
3477 | ||
60813a46 JM |
3478 | /* And then find the underlying variable. */ |
3479 | vec<tree,va_gc> *refs = make_tree_vector(); | |
3480 | tree object = NULL_TREE; | |
3481 | for (tree probe = target; object == NULL_TREE; ) | |
3482 | { | |
3483 | switch (TREE_CODE (probe)) | |
3484 | { | |
3485 | case BIT_FIELD_REF: | |
3486 | case COMPONENT_REF: | |
3487 | case ARRAY_REF: | |
3488 | vec_safe_push (refs, TREE_OPERAND (probe, 1)); | |
3489 | vec_safe_push (refs, TREE_TYPE (probe)); | |
3490 | probe = TREE_OPERAND (probe, 0); | |
3491 | break; | |
3492 | ||
3493 | default: | |
3494 | object = probe; | |
60813a46 JM |
3495 | } |
3496 | } | |
3497 | ||
3498 | /* And then find/build up our initializer for the path to the subobject | |
3499 | we're initializing. */ | |
a1408b7e | 3500 | tree *valp; |
1e163090 JM |
3501 | if (object == ctx->object && VAR_P (object) |
3502 | && DECL_NAME (object) && ctx->call == NULL) | |
3503 | /* The variable we're building up an aggregate initializer for is outside | |
3504 | the constant-expression, so don't evaluate the store. We check | |
3505 | DECL_NAME to handle TARGET_EXPR temporaries, which are fair game. */ | |
3506 | valp = NULL; | |
3507 | else if (DECL_P (object)) | |
a1408b7e JM |
3508 | valp = ctx->values->get (object); |
3509 | else | |
3510 | valp = NULL; | |
60813a46 JM |
3511 | if (!valp) |
3512 | { | |
3513 | /* A constant-expression cannot modify objects from outside the | |
3514 | constant-expression. */ | |
2b3ab879 | 3515 | if (!ctx->quiet) |
64d6d399 | 3516 | error ("modification of %qE is not a constant expression", object); |
60813a46 JM |
3517 | *non_constant_p = true; |
3518 | return t; | |
3519 | } | |
3f8e2835 | 3520 | type = TREE_TYPE (object); |
c75ce530 | 3521 | bool no_zero_init = true; |
2d63bc39 JM |
3522 | |
3523 | vec<tree,va_gc> *ctors = make_tree_vector (); | |
60813a46 JM |
3524 | while (!refs->is_empty()) |
3525 | { | |
3526 | if (*valp == NULL_TREE) | |
3527 | { | |
3528 | *valp = build_constructor (type, NULL); | |
c75ce530 | 3529 | CONSTRUCTOR_NO_IMPLICIT_ZERO (*valp) = no_zero_init; |
60813a46 | 3530 | } |
d6b46fca NS |
3531 | else if (TREE_CODE (*valp) == STRING_CST) |
3532 | { | |
3533 | /* An array was initialized with a string constant, and now | |
3534 | we're writing into one of its elements. Explode the | |
3535 | single initialization into a set of element | |
3536 | initializations. */ | |
3537 | gcc_assert (TREE_CODE (type) == ARRAY_TYPE); | |
3538 | ||
3539 | tree string = *valp; | |
3540 | tree elt_type = TREE_TYPE (type); | |
3541 | unsigned chars_per_elt = (TYPE_PRECISION (elt_type) | |
3542 | / TYPE_PRECISION (char_type_node)); | |
3543 | unsigned num_elts = TREE_STRING_LENGTH (string) / chars_per_elt; | |
3544 | tree ary_ctor = build_constructor (type, NULL); | |
3545 | ||
3546 | vec_safe_reserve (CONSTRUCTOR_ELTS (ary_ctor), num_elts); | |
3547 | for (unsigned ix = 0; ix != num_elts; ix++) | |
3548 | { | |
3549 | constructor_elt elt = | |
3550 | { | |
3551 | build_int_cst (size_type_node, ix), | |
3552 | extract_string_elt (string, chars_per_elt, ix) | |
3553 | }; | |
3554 | CONSTRUCTOR_ELTS (ary_ctor)->quick_push (elt); | |
3555 | } | |
3556 | ||
3557 | *valp = ary_ctor; | |
3558 | } | |
3559 | ||
c75ce530 JM |
3560 | /* If the value of object is already zero-initialized, any new ctors for |
3561 | subobjects will also be zero-initialized. */ | |
3562 | no_zero_init = CONSTRUCTOR_NO_IMPLICIT_ZERO (*valp); | |
60813a46 | 3563 | |
2d63bc39 JM |
3564 | vec_safe_push (ctors, *valp); |
3565 | ||
ceaaf873 | 3566 | enum tree_code code = TREE_CODE (type); |
60813a46 | 3567 | type = refs->pop(); |
ceaaf873 | 3568 | tree index = refs->pop(); |
60813a46 | 3569 | |
60813a46 | 3570 | constructor_elt *cep = NULL; |
ceaaf873 JM |
3571 | if (code == ARRAY_TYPE) |
3572 | { | |
3573 | HOST_WIDE_INT i | |
3574 | = find_array_ctor_elt (*valp, index, /*insert*/true); | |
3575 | gcc_assert (i >= 0); | |
3576 | cep = CONSTRUCTOR_ELT (*valp, i); | |
3577 | gcc_assert (TREE_CODE (cep->index) != RANGE_EXPR); | |
3578 | } | |
3579 | else | |
3580 | { | |
3581 | gcc_assert (TREE_CODE (index) == FIELD_DECL); | |
88504f34 NS |
3582 | |
3583 | /* We must keep the CONSTRUCTOR's ELTS in FIELD order. | |
3584 | Usually we meet initializers in that order, but it is | |
3585 | possible for base types to be placed not in program | |
3586 | order. */ | |
3587 | tree fields = TYPE_FIELDS (DECL_CONTEXT (index)); | |
3588 | unsigned HOST_WIDE_INT idx; | |
3589 | ||
5c97093b JM |
3590 | if (code == UNION_TYPE && CONSTRUCTOR_NELTS (*valp) |
3591 | && CONSTRUCTOR_ELT (*valp, 0)->index != index) | |
3592 | /* Changing active member. */ | |
3593 | vec_safe_truncate (CONSTRUCTOR_ELTS (*valp), 0); | |
3594 | ||
88504f34 | 3595 | for (idx = 0; |
ceaaf873 | 3596 | vec_safe_iterate (CONSTRUCTOR_ELTS (*valp), idx, &cep); |
88504f34 | 3597 | idx++, fields = DECL_CHAIN (fields)) |
ceaaf873 | 3598 | { |
88504f34 NS |
3599 | if (index == cep->index) |
3600 | goto found; | |
3601 | ||
3602 | /* The field we're initializing must be on the field | |
3603 | list. Look to see if it is present before the | |
3604 | field the current ELT initializes. */ | |
3605 | for (; fields != cep->index; fields = DECL_CHAIN (fields)) | |
3606 | if (index == fields) | |
3607 | goto insert; | |
ceaaf873 | 3608 | } |
88504f34 NS |
3609 | |
3610 | /* We fell off the end of the CONSTRUCTOR, so insert a new | |
3611 | entry at the end. */ | |
3612 | insert: | |
3613 | { | |
3614 | constructor_elt ce = { index, NULL_TREE }; | |
3615 | ||
3616 | vec_safe_insert (CONSTRUCTOR_ELTS (*valp), idx, ce); | |
3617 | cep = CONSTRUCTOR_ELT (*valp, idx); | |
3618 | } | |
3619 | found:; | |
ceaaf873 | 3620 | } |
60813a46 JM |
3621 | valp = &cep->value; |
3622 | } | |
3623 | release_tree_vector (refs); | |
3624 | ||
acb2970c | 3625 | if (AGGREGATE_TYPE_P (type) || VECTOR_TYPE_P (type)) |
60813a46 JM |
3626 | { |
3627 | /* Create a new CONSTRUCTOR in case evaluation of the initializer | |
3628 | wants to modify it. */ | |
acb2970c | 3629 | if (*valp == NULL_TREE) |
73a84269 | 3630 | { |
664beaf2 JJ |
3631 | *valp = build_constructor (type, NULL); |
3632 | CONSTRUCTOR_NO_IMPLICIT_ZERO (*valp) = no_zero_init; | |
73a84269 | 3633 | } |
664beaf2 JJ |
3634 | else if (TREE_CODE (*valp) == PTRMEM_CST) |
3635 | *valp = cplus_expand_constant (*valp); | |
3636 | new_ctx.ctor = *valp; | |
60813a46 JM |
3637 | new_ctx.object = target; |
3638 | } | |
3639 | ||
58cc255c JM |
3640 | init = cxx_eval_constant_expression (&new_ctx, init, false, |
3641 | non_constant_p, overflow_p); | |
7574c916 | 3642 | /* Don't share a CONSTRUCTOR that might be changed later. */ |
0146e25f | 3643 | init = unshare_constructor (init); |
60813a46 | 3644 | if (target == object) |
d96e8407 JM |
3645 | /* The hash table might have moved since the get earlier. */ |
3646 | valp = ctx->values->get (object); | |
3647 | ||
3648 | if (TREE_CODE (init) == CONSTRUCTOR) | |
acb2970c | 3649 | { |
d96e8407 JM |
3650 | /* An outer ctx->ctor might be pointing to *valp, so replace |
3651 | its contents. */ | |
3652 | CONSTRUCTOR_ELTS (*valp) = CONSTRUCTOR_ELTS (init); | |
3653 | TREE_CONSTANT (*valp) = TREE_CONSTANT (init); | |
3654 | TREE_SIDE_EFFECTS (*valp) = TREE_SIDE_EFFECTS (init); | |
3ae9a8b7 JM |
3655 | CONSTRUCTOR_NO_IMPLICIT_ZERO (*valp) |
3656 | = CONSTRUCTOR_NO_IMPLICIT_ZERO (init); | |
acb2970c | 3657 | } |
60813a46 | 3658 | else |
d96e8407 | 3659 | *valp = init; |
2d63bc39 | 3660 | |
d96e8407 JM |
3661 | /* Update TREE_CONSTANT and TREE_SIDE_EFFECTS on enclosing |
3662 | CONSTRUCTORs, if any. */ | |
3663 | tree elt; | |
3664 | unsigned i; | |
3665 | bool c = TREE_CONSTANT (init); | |
3666 | bool s = TREE_SIDE_EFFECTS (init); | |
3667 | if (!c || s) | |
3668 | FOR_EACH_VEC_SAFE_ELT (ctors, i, elt) | |
3669 | { | |
3670 | if (!c) | |
3671 | TREE_CONSTANT (elt) = false; | |
3672 | if (s) | |
3673 | TREE_SIDE_EFFECTS (elt) = true; | |
3674 | } | |
2d63bc39 | 3675 | release_tree_vector (ctors); |
60813a46 JM |
3676 | |
3677 | if (*non_constant_p) | |
3678 | return t; | |
92a596e8 | 3679 | else if (lval) |
60813a46 JM |
3680 | return target; |
3681 | else | |
3bdf0a9b | 3682 | return init; |
60813a46 JM |
3683 | } |
3684 | ||
3685 | /* Evaluate a ++ or -- expression. */ | |
3686 | ||
3687 | static tree | |
3688 | cxx_eval_increment_expression (const constexpr_ctx *ctx, tree t, | |
92a596e8 | 3689 | bool lval, |
60813a46 JM |
3690 | bool *non_constant_p, bool *overflow_p) |
3691 | { | |
3692 | enum tree_code code = TREE_CODE (t); | |
3693 | tree type = TREE_TYPE (t); | |
3694 | tree op = TREE_OPERAND (t, 0); | |
3695 | tree offset = TREE_OPERAND (t, 1); | |
3696 | gcc_assert (TREE_CONSTANT (offset)); | |
3697 | ||
3698 | /* The operand as an lvalue. */ | |
2b3ab879 | 3699 | op = cxx_eval_constant_expression (ctx, op, true, |
5a804683 | 3700 | non_constant_p, overflow_p); |
60813a46 JM |
3701 | |
3702 | /* The operand as an rvalue. */ | |
84dd815f JM |
3703 | tree val |
3704 | = cxx_eval_constant_expression (ctx, op, false, | |
3705 | non_constant_p, overflow_p); | |
caee690e JM |
3706 | /* Don't VERIFY_CONSTANT if this might be dealing with a pointer to |
3707 | a local array in a constexpr function. */ | |
3708 | bool ptr = POINTER_TYPE_P (TREE_TYPE (val)); | |
3709 | if (!ptr) | |
3710 | VERIFY_CONSTANT (val); | |
60813a46 JM |
3711 | |
3712 | /* The modified value. */ | |
3713 | bool inc = (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR); | |
ac2f8d26 JM |
3714 | tree mod; |
3715 | if (POINTER_TYPE_P (type)) | |
3716 | { | |
3717 | /* The middle end requires pointers to use POINTER_PLUS_EXPR. */ | |
3718 | offset = convert_to_ptrofftype (offset); | |
3719 | if (!inc) | |
3720 | offset = fold_build1 (NEGATE_EXPR, TREE_TYPE (offset), offset); | |
3721 | mod = fold_build2 (POINTER_PLUS_EXPR, type, val, offset); | |
3722 | } | |
3723 | else | |
3724 | mod = fold_build2 (inc ? PLUS_EXPR : MINUS_EXPR, type, val, offset); | |
caee690e JM |
3725 | if (!ptr) |
3726 | VERIFY_CONSTANT (mod); | |
60813a46 JM |
3727 | |
3728 | /* Storing the modified value. */ | |
3729 | tree store = build2 (MODIFY_EXPR, type, op, mod); | |
2b3ab879 | 3730 | cxx_eval_constant_expression (ctx, store, |
5a804683 | 3731 | true, non_constant_p, overflow_p); |
60813a46 JM |
3732 | |
3733 | /* And the value of the expression. */ | |
3734 | if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR) | |
3735 | { | |
3736 | /* Prefix ops are lvalues. */ | |
92a596e8 | 3737 | if (lval) |
60813a46 JM |
3738 | return op; |
3739 | else | |
3740 | /* But we optimize when the caller wants an rvalue. */ | |
3741 | return mod; | |
3742 | } | |
3743 | else | |
3744 | /* Postfix ops are rvalues. */ | |
3745 | return val; | |
3746 | } | |
3747 | ||
56632b27 JM |
3748 | /* Predicates for the meaning of *jump_target. */ |
3749 | ||
3750 | static bool | |
3751 | returns (tree *jump_target) | |
3752 | { | |
3753 | return *jump_target | |
d49318d9 PC |
3754 | && (TREE_CODE (*jump_target) == RETURN_EXPR |
3755 | || (TREE_CODE (*jump_target) == LABEL_DECL | |
3756 | && LABEL_DECL_CDTOR (*jump_target))); | |
56632b27 JM |
3757 | } |
3758 | ||
3759 | static bool | |
3760 | breaks (tree *jump_target) | |
3761 | { | |
3762 | return *jump_target | |
06ec22b7 JM |
3763 | && ((TREE_CODE (*jump_target) == LABEL_DECL |
3764 | && LABEL_DECL_BREAK (*jump_target)) | |
3765 | || TREE_CODE (*jump_target) == EXIT_EXPR); | |
56632b27 JM |
3766 | } |
3767 | ||
3768 | static bool | |
3769 | continues (tree *jump_target) | |
3770 | { | |
3771 | return *jump_target | |
3772 | && TREE_CODE (*jump_target) == LABEL_DECL | |
3773 | && LABEL_DECL_CONTINUE (*jump_target); | |
3774 | } | |
3775 | ||
3776 | static bool | |
3777 | switches (tree *jump_target) | |
3778 | { | |
3779 | return *jump_target | |
3780 | && TREE_CODE (*jump_target) == INTEGER_CST; | |
3781 | } | |
3782 | ||
3783 | /* Subroutine of cxx_eval_statement_list. Determine whether the statement | |
4b390698 JJ |
3784 | STMT matches *jump_target. If we're looking for a case label and we see |
3785 | the default label, note it in ctx->css_state. */ | |
56632b27 JM |
3786 | |
3787 | static bool | |
4b390698 | 3788 | label_matches (const constexpr_ctx *ctx, tree *jump_target, tree stmt) |
56632b27 | 3789 | { |
56632b27 JM |
3790 | switch (TREE_CODE (*jump_target)) |
3791 | { | |
3792 | case LABEL_DECL: | |
3793 | if (TREE_CODE (stmt) == LABEL_EXPR | |
3794 | && LABEL_EXPR_LABEL (stmt) == *jump_target) | |
3795 | return true; | |
3796 | break; | |
3797 | ||
3798 | case INTEGER_CST: | |
3799 | if (TREE_CODE (stmt) == CASE_LABEL_EXPR) | |
3800 | { | |
4b390698 | 3801 | gcc_assert (ctx->css_state != NULL); |
56632b27 | 3802 | if (!CASE_LOW (stmt)) |
4b390698 JJ |
3803 | { |
3804 | /* default: should appear just once in a SWITCH_EXPR | |
3805 | body (excluding nested SWITCH_EXPR). */ | |
3806 | gcc_assert (*ctx->css_state != css_default_seen); | |
3807 | /* When evaluating SWITCH_EXPR body for the second time, | |
3808 | return true for the default: label. */ | |
3809 | if (*ctx->css_state == css_default_processing) | |
3810 | return true; | |
3811 | *ctx->css_state = css_default_seen; | |
3812 | } | |
385ed708 JJ |
3813 | else if (CASE_HIGH (stmt)) |
3814 | { | |
3815 | if (tree_int_cst_le (CASE_LOW (stmt), *jump_target) | |
3816 | && tree_int_cst_le (*jump_target, CASE_HIGH (stmt))) | |
3817 | return true; | |
3818 | } | |
56632b27 JM |
3819 | else if (tree_int_cst_equal (*jump_target, CASE_LOW (stmt))) |
3820 | return true; | |
3821 | } | |
3822 | break; | |
3823 | ||
3824 | default: | |
3825 | gcc_unreachable (); | |
3826 | } | |
3827 | return false; | |
3828 | } | |
3829 | ||
3830 | /* Evaluate a STATEMENT_LIST for side-effects. Handles various jump | |
3831 | semantics, for switch, break, continue, and return. */ | |
3832 | ||
3833 | static tree | |
3834 | cxx_eval_statement_list (const constexpr_ctx *ctx, tree t, | |
56632b27 JM |
3835 | bool *non_constant_p, bool *overflow_p, |
3836 | tree *jump_target) | |
3837 | { | |
3838 | tree_stmt_iterator i; | |
58611fb6 | 3839 | tree local_target; |
345edb37 JJ |
3840 | /* In a statement-expression we want to return the last value. |
3841 | For empty statement expression return void_node. */ | |
3842 | tree r = void_node; | |
58611fb6 JM |
3843 | if (!jump_target) |
3844 | { | |
3845 | local_target = NULL_TREE; | |
3846 | jump_target = &local_target; | |
3847 | } | |
56632b27 JM |
3848 | for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i)) |
3849 | { | |
56632b27 | 3850 | tree stmt = tsi_stmt (i); |
58611fb6 JM |
3851 | r = cxx_eval_constant_expression (ctx, stmt, false, |
3852 | non_constant_p, overflow_p, | |
3853 | jump_target); | |
56632b27 JM |
3854 | if (*non_constant_p) |
3855 | break; | |
3856 | if (returns (jump_target) || breaks (jump_target)) | |
3857 | break; | |
3858 | } | |
58611fb6 | 3859 | return r; |
56632b27 JM |
3860 | } |
3861 | ||
3862 | /* Evaluate a LOOP_EXPR for side-effects. Handles break and return | |
3863 | semantics; continue semantics are covered by cxx_eval_statement_list. */ | |
3864 | ||
3865 | static tree | |
3866 | cxx_eval_loop_expr (const constexpr_ctx *ctx, tree t, | |
56632b27 JM |
3867 | bool *non_constant_p, bool *overflow_p, |
3868 | tree *jump_target) | |
3869 | { | |
39dce2b7 JM |
3870 | constexpr_ctx new_ctx = *ctx; |
3871 | ||
56632b27 | 3872 | tree body = TREE_OPERAND (t, 0); |
5ec2cd9f | 3873 | int count = 0; |
d259b234 | 3874 | do |
56632b27 | 3875 | { |
39dce2b7 JM |
3876 | hash_set<tree> save_exprs; |
3877 | new_ctx.save_exprs = &save_exprs; | |
3878 | ||
06ec22b7 JM |
3879 | cxx_eval_constant_expression (&new_ctx, body, /*lval*/false, |
3880 | non_constant_p, overflow_p, jump_target); | |
39dce2b7 JM |
3881 | |
3882 | /* Forget saved values of SAVE_EXPRs. */ | |
3883 | for (hash_set<tree>::iterator iter = save_exprs.begin(); | |
3884 | iter != save_exprs.end(); ++iter) | |
3885 | new_ctx.values->remove (*iter); | |
5ec2cd9f JM |
3886 | if (++count >= constexpr_loop_limit) |
3887 | { | |
3888 | if (!ctx->quiet) | |
3889 | error_at (EXPR_LOC_OR_LOC (t, input_location), | |
84fa214d | 3890 | "%<constexpr%> loop iteration count exceeds limit of %d " |
5ec2cd9f JM |
3891 | "(use -fconstexpr-loop-limit= to increase the limit)", |
3892 | constexpr_loop_limit); | |
3893 | *non_constant_p = true; | |
3894 | break; | |
3895 | } | |
56632b27 | 3896 | } |
4b390698 JJ |
3897 | while (!returns (jump_target) |
3898 | && !breaks (jump_target) | |
3899 | && !switches (jump_target) | |
3900 | && !*non_constant_p); | |
d259b234 | 3901 | |
56632b27 JM |
3902 | if (breaks (jump_target)) |
3903 | *jump_target = NULL_TREE; | |
39dce2b7 | 3904 | |
56632b27 JM |
3905 | return NULL_TREE; |
3906 | } | |
3907 | ||
3908 | /* Evaluate a SWITCH_EXPR for side-effects. Handles switch and break jump | |
3909 | semantics. */ | |
3910 | ||
3911 | static tree | |
3912 | cxx_eval_switch_expr (const constexpr_ctx *ctx, tree t, | |
56632b27 JM |
3913 | bool *non_constant_p, bool *overflow_p, |
3914 | tree *jump_target) | |
3915 | { | |
3916 | tree cond = TREE_OPERAND (t, 0); | |
2b3ab879 | 3917 | cond = cxx_eval_constant_expression (ctx, cond, false, |
5a804683 | 3918 | non_constant_p, overflow_p); |
56632b27 JM |
3919 | VERIFY_CONSTANT (cond); |
3920 | *jump_target = cond; | |
3921 | ||
3922 | tree body = TREE_OPERAND (t, 1); | |
4b390698 JJ |
3923 | constexpr_ctx new_ctx = *ctx; |
3924 | constexpr_switch_state css = css_default_not_seen; | |
3925 | new_ctx.css_state = &css; | |
3926 | cxx_eval_constant_expression (&new_ctx, body, false, | |
3927 | non_constant_p, overflow_p, jump_target); | |
3928 | if (switches (jump_target) && css == css_default_seen) | |
3929 | { | |
3930 | /* If the SWITCH_EXPR body has default: label, process it once again, | |
3931 | this time instructing label_matches to return true for default: | |
3932 | label on switches (jump_target). */ | |
3933 | css = css_default_processing; | |
3934 | cxx_eval_constant_expression (&new_ctx, body, false, | |
3935 | non_constant_p, overflow_p, jump_target); | |
3936 | } | |
56632b27 JM |
3937 | if (breaks (jump_target) || switches (jump_target)) |
3938 | *jump_target = NULL_TREE; | |
3939 | return NULL_TREE; | |
3940 | } | |
3941 | ||
89262ec6 JM |
3942 | /* Find the object of TYPE under initialization in CTX. */ |
3943 | ||
3944 | static tree | |
3945 | lookup_placeholder (const constexpr_ctx *ctx, bool lval, tree type) | |
3946 | { | |
fbd603c4 | 3947 | if (!ctx) |
89262ec6 JM |
3948 | return NULL_TREE; |
3949 | ||
3950 | /* We could use ctx->object unconditionally, but using ctx->ctor when we | |
3951 | can is a minor optimization. */ | |
fbd603c4 | 3952 | if (!lval && ctx->ctor && same_type_p (TREE_TYPE (ctx->ctor), type)) |
89262ec6 JM |
3953 | return ctx->ctor; |
3954 | ||
fbd603c4 JM |
3955 | if (!ctx->object) |
3956 | return NULL_TREE; | |
3957 | ||
89262ec6 JM |
3958 | /* Since an object cannot have a field of its own type, we can search outward |
3959 | from ctx->object to find the unique containing object of TYPE. */ | |
3960 | tree ob = ctx->object; | |
3961 | while (ob) | |
3962 | { | |
3963 | if (same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (ob), type)) | |
3964 | break; | |
3965 | if (handled_component_p (ob)) | |
3966 | ob = TREE_OPERAND (ob, 0); | |
3967 | else | |
3968 | ob = NULL_TREE; | |
3969 | } | |
3970 | ||
3971 | return ob; | |
3972 | } | |
3973 | ||
2d76680f PC |
3974 | /* Attempt to reduce the expression T to a constant value. |
3975 | On failure, issue diagnostic and return error_mark_node. */ | |
3976 | /* FIXME unify with c_fully_fold */ | |
60813a46 | 3977 | /* FIXME overflow_p is too global */ |
2d76680f PC |
3978 | |
3979 | static tree | |
3e605b20 | 3980 | cxx_eval_constant_expression (const constexpr_ctx *ctx, tree t, |
92a596e8 | 3981 | bool lval, |
56632b27 JM |
3982 | bool *non_constant_p, bool *overflow_p, |
3983 | tree *jump_target) | |
2d76680f | 3984 | { |
3e605b20 | 3985 | constexpr_ctx new_ctx; |
2d76680f PC |
3986 | tree r = t; |
3987 | ||
4b390698 JJ |
3988 | if (jump_target && *jump_target) |
3989 | { | |
3990 | /* If we are jumping, ignore all statements/expressions except those | |
3991 | that could have LABEL_EXPR or CASE_LABEL_EXPR in their bodies. */ | |
3992 | switch (TREE_CODE (t)) | |
3993 | { | |
3994 | case BIND_EXPR: | |
3995 | case STATEMENT_LIST: | |
3996 | case LOOP_EXPR: | |
3997 | case COND_EXPR: | |
3998 | break; | |
3999 | case LABEL_EXPR: | |
4000 | case CASE_LABEL_EXPR: | |
4001 | if (label_matches (ctx, jump_target, t)) | |
4002 | /* Found it. */ | |
4003 | *jump_target = NULL_TREE; | |
4004 | return NULL_TREE; | |
4005 | default: | |
4006 | return NULL_TREE; | |
4007 | } | |
4008 | } | |
2d76680f PC |
4009 | if (t == error_mark_node) |
4010 | { | |
4011 | *non_constant_p = true; | |
4012 | return t; | |
4013 | } | |
4014 | if (CONSTANT_CLASS_P (t)) | |
4015 | { | |
61637db3 JJ |
4016 | if (TREE_OVERFLOW (t)) |
4017 | { | |
4018 | if (!ctx->quiet) | |
4019 | permerror (input_location, "overflow in constant expression"); | |
4020 | if (!flag_permissive || ctx->quiet) | |
4021 | *overflow_p = true; | |
4022 | } | |
8bada5cd MS |
4023 | |
4024 | if (TREE_CODE (t) == INTEGER_CST | |
4025 | && TREE_CODE (TREE_TYPE (t)) == POINTER_TYPE | |
4026 | && !integer_zerop (t)) | |
4027 | { | |
4028 | if (!ctx->quiet) | |
4029 | error ("value %qE of type %qT is not a constant expression", | |
4030 | t, TREE_TYPE (t)); | |
4031 | *non_constant_p = true; | |
4032 | } | |
4033 | ||
2d76680f PC |
4034 | return t; |
4035 | } | |
2d76680f | 4036 | |
8bada5cd MS |
4037 | tree_code tcode = TREE_CODE (t); |
4038 | switch (tcode) | |
2d76680f | 4039 | { |
60813a46 | 4040 | case RESULT_DECL: |
92a596e8 | 4041 | if (lval) |
60813a46 JM |
4042 | return t; |
4043 | /* We ask for an rvalue for the RESULT_DECL when indirecting | |
bf66b9b4 AH |
4044 | through an invisible reference, or in named return value |
4045 | optimization. */ | |
60813a46 JM |
4046 | return (*ctx->values->get (t)); |
4047 | ||
2d76680f | 4048 | case VAR_DECL: |
70f40fea | 4049 | if (DECL_HAS_VALUE_EXPR_P (t)) |
98e5a19a JM |
4050 | return cxx_eval_constant_expression (ctx, DECL_VALUE_EXPR (t), |
4051 | lval, non_constant_p, overflow_p); | |
191816a3 | 4052 | /* fall through */ |
7c83622c JM |
4053 | case CONST_DECL: |
4054 | /* We used to not check lval for CONST_DECL, but darwin.c uses | |
4055 | CONST_DECL for aggregate constants. */ | |
92a596e8 | 4056 | if (lval) |
2d76680f | 4057 | return t; |
f4fce183 JM |
4058 | if (COMPLETE_TYPE_P (TREE_TYPE (t)) |
4059 | && is_really_empty_class (TREE_TYPE (t))) | |
7dc2b4a2 JM |
4060 | { |
4061 | /* If the class is empty, we aren't actually loading anything. */ | |
4062 | r = build_constructor (TREE_TYPE (t), NULL); | |
4063 | TREE_CONSTANT (r) = true; | |
4064 | } | |
4065 | else if (ctx->strict) | |
69eb4fde JM |
4066 | r = decl_really_constant_value (t); |
4067 | else | |
4068 | r = decl_constant_value (t); | |
2d76680f PC |
4069 | if (TREE_CODE (r) == TARGET_EXPR |
4070 | && TREE_CODE (TARGET_EXPR_INITIAL (r)) == CONSTRUCTOR) | |
4071 | r = TARGET_EXPR_INITIAL (r); | |
56a6f1d3 | 4072 | if (VAR_P (r)) |
3e605b20 | 4073 | if (tree *p = ctx->values->get (r)) |
bd8f5bb2 MP |
4074 | if (*p != NULL_TREE) |
4075 | r = *p; | |
2d76680f PC |
4076 | if (DECL_P (r)) |
4077 | { | |
2b3ab879 | 4078 | if (!ctx->quiet) |
2d76680f PC |
4079 | non_const_var_error (r); |
4080 | *non_constant_p = true; | |
4081 | } | |
4082 | break; | |
4083 | ||
4084 | case FUNCTION_DECL: | |
4085 | case TEMPLATE_DECL: | |
4086 | case LABEL_DECL: | |
56632b27 JM |
4087 | case LABEL_EXPR: |
4088 | case CASE_LABEL_EXPR: | |
4b390698 | 4089 | case PREDICT_EXPR: |
2d76680f PC |
4090 | return t; |
4091 | ||
4092 | case PARM_DECL: | |
0567dcd2 | 4093 | if (lval && TREE_CODE (TREE_TYPE (t)) != REFERENCE_TYPE) |
60813a46 JM |
4094 | /* glvalue use. */; |
4095 | else if (tree *p = ctx->values->get (r)) | |
4096 | r = *p; | |
92a596e8 | 4097 | else if (lval) |
2d76680f | 4098 | /* Defer in case this is only used for its type. */; |
f2acb8ad JM |
4099 | else if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE) |
4100 | /* Defer, there's no lvalue->rvalue conversion. */; | |
1c2f613f JJ |
4101 | else if (COMPLETE_TYPE_P (TREE_TYPE (t)) |
4102 | && is_really_empty_class (TREE_TYPE (t))) | |
052beba4 JM |
4103 | { |
4104 | /* If the class is empty, we aren't actually loading anything. */ | |
4105 | r = build_constructor (TREE_TYPE (t), NULL); | |
4106 | TREE_CONSTANT (r) = true; | |
4107 | } | |
2d76680f PC |
4108 | else |
4109 | { | |
2b3ab879 | 4110 | if (!ctx->quiet) |
2d76680f PC |
4111 | error ("%qE is not a constant expression", t); |
4112 | *non_constant_p = true; | |
4113 | } | |
4114 | break; | |
4115 | ||
4116 | case CALL_EXPR: | |
4117 | case AGGR_INIT_EXPR: | |
92a596e8 | 4118 | r = cxx_eval_call_expression (ctx, t, lval, |
2d76680f PC |
4119 | non_constant_p, overflow_p); |
4120 | break; | |
4121 | ||
60813a46 JM |
4122 | case DECL_EXPR: |
4123 | { | |
4124 | r = DECL_EXPR_DECL (t); | |
4125 | if (AGGREGATE_TYPE_P (TREE_TYPE (r)) | |
4126 | || VECTOR_TYPE_P (TREE_TYPE (r))) | |
4127 | { | |
4128 | new_ctx = *ctx; | |
4129 | new_ctx.object = r; | |
4130 | new_ctx.ctor = build_constructor (TREE_TYPE (r), NULL); | |
4131 | CONSTRUCTOR_NO_IMPLICIT_ZERO (new_ctx.ctor) = true; | |
4132 | new_ctx.values->put (r, new_ctx.ctor); | |
4133 | ctx = &new_ctx; | |
4134 | } | |
4135 | ||
4136 | if (tree init = DECL_INITIAL (r)) | |
4137 | { | |
4138 | init = cxx_eval_constant_expression (ctx, init, | |
2b3ab879 | 4139 | false, |
5a804683 | 4140 | non_constant_p, overflow_p); |
7f0e23e9 | 4141 | /* Don't share a CONSTRUCTOR that might be changed. */ |
0146e25f | 4142 | init = unshare_constructor (init); |
60813a46 JM |
4143 | ctx->values->put (r, init); |
4144 | } | |
4145 | else if (ctx == &new_ctx) | |
4146 | /* We gave it a CONSTRUCTOR above. */; | |
4147 | else | |
4148 | ctx->values->put (r, NULL_TREE); | |
4149 | } | |
4150 | break; | |
4151 | ||
2d76680f PC |
4152 | case TARGET_EXPR: |
4153 | if (!literal_type_p (TREE_TYPE (t))) | |
4154 | { | |
2b3ab879 | 4155 | if (!ctx->quiet) |
2d76680f PC |
4156 | { |
4157 | error ("temporary of non-literal type %qT in a " | |
4158 | "constant expression", TREE_TYPE (t)); | |
4159 | explain_non_literal_class (TREE_TYPE (t)); | |
4160 | } | |
4161 | *non_constant_p = true; | |
4162 | break; | |
4163 | } | |
3e605b20 JM |
4164 | if ((AGGREGATE_TYPE_P (TREE_TYPE (t)) || VECTOR_TYPE_P (TREE_TYPE (t)))) |
4165 | { | |
4166 | /* We're being expanded without an explicit target, so start | |
4167 | initializing a new object; expansion with an explicit target | |
4168 | strips the TARGET_EXPR before we get here. */ | |
4169 | new_ctx = *ctx; | |
4170 | new_ctx.ctor = build_constructor (TREE_TYPE (t), NULL); | |
4171 | CONSTRUCTOR_NO_IMPLICIT_ZERO (new_ctx.ctor) = true; | |
4172 | new_ctx.object = TARGET_EXPR_SLOT (t); | |
4173 | ctx->values->put (new_ctx.object, new_ctx.ctor); | |
4174 | ctx = &new_ctx; | |
4175 | } | |
92a596e8 | 4176 | /* Pass false for 'lval' because this indicates |
2d76680f | 4177 | initialization of a temporary. */ |
3e605b20 | 4178 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), |
2b3ab879 | 4179 | false, |
5a804683 | 4180 | non_constant_p, overflow_p); |
2d76680f PC |
4181 | if (!*non_constant_p) |
4182 | /* Adjust the type of the result to the type of the temporary. */ | |
4183 | r = adjust_temp_type (TREE_TYPE (t), r); | |
92a596e8 | 4184 | if (lval) |
f2acb8ad JM |
4185 | { |
4186 | tree slot = TARGET_EXPR_SLOT (t); | |
0146e25f | 4187 | r = unshare_constructor (r); |
f2acb8ad JM |
4188 | ctx->values->put (slot, r); |
4189 | return slot; | |
4190 | } | |
2d76680f PC |
4191 | break; |
4192 | ||
60813a46 | 4193 | case INIT_EXPR: |
60813a46 | 4194 | case MODIFY_EXPR: |
4b390698 | 4195 | gcc_assert (jump_target == NULL || *jump_target == NULL_TREE); |
92a596e8 | 4196 | r = cxx_eval_store_expression (ctx, t, lval, |
60813a46 JM |
4197 | non_constant_p, overflow_p); |
4198 | break; | |
4199 | ||
2d76680f | 4200 | case SCOPE_REF: |
3e605b20 | 4201 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), |
92a596e8 | 4202 | lval, |
5a804683 | 4203 | non_constant_p, overflow_p); |
2d76680f PC |
4204 | break; |
4205 | ||
4206 | case RETURN_EXPR: | |
75e0295b MP |
4207 | if (TREE_OPERAND (t, 0) != NULL_TREE) |
4208 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), | |
4209 | lval, | |
4210 | non_constant_p, overflow_p); | |
56632b27 JM |
4211 | *jump_target = t; |
4212 | break; | |
4213 | ||
cabaf50a JM |
4214 | case SAVE_EXPR: |
4215 | /* Avoid evaluating a SAVE_EXPR more than once. */ | |
4216 | if (tree *p = ctx->values->get (t)) | |
4217 | r = *p; | |
4218 | else | |
4219 | { | |
12d9ce19 | 4220 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), false, |
cabaf50a JM |
4221 | non_constant_p, overflow_p); |
4222 | ctx->values->put (t, r); | |
39dce2b7 JM |
4223 | if (ctx->save_exprs) |
4224 | ctx->save_exprs->add (t); | |
cabaf50a JM |
4225 | } |
4226 | break; | |
4227 | ||
2d76680f PC |
4228 | case NON_LVALUE_EXPR: |
4229 | case TRY_CATCH_EXPR: | |
769430b2 | 4230 | case TRY_BLOCK: |
2d76680f PC |
4231 | case CLEANUP_POINT_EXPR: |
4232 | case MUST_NOT_THROW_EXPR: | |
60813a46 JM |
4233 | case EXPR_STMT: |
4234 | case EH_SPEC_BLOCK: | |
3e605b20 | 4235 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), |
92a596e8 | 4236 | lval, |
56632b27 JM |
4237 | non_constant_p, overflow_p, |
4238 | jump_target); | |
2d76680f PC |
4239 | break; |
4240 | ||
769430b2 JM |
4241 | case TRY_FINALLY_EXPR: |
4242 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval, | |
4243 | non_constant_p, overflow_p, | |
4244 | jump_target); | |
4245 | if (!*non_constant_p) | |
4246 | /* Also evaluate the cleanup. */ | |
4247 | cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), true, | |
4248 | non_constant_p, overflow_p, | |
4249 | jump_target); | |
4250 | break; | |
4251 | ||
2d76680f PC |
4252 | /* These differ from cxx_eval_unary_expression in that this doesn't |
4253 | check for a constant operand or result; an address can be | |
4254 | constant without its operand being, and vice versa. */ | |
cda0a029 | 4255 | case MEM_REF: |
2d76680f | 4256 | case INDIRECT_REF: |
92a596e8 | 4257 | r = cxx_eval_indirect_ref (ctx, t, lval, |
2d76680f PC |
4258 | non_constant_p, overflow_p); |
4259 | break; | |
4260 | ||
4261 | case ADDR_EXPR: | |
4262 | { | |
4263 | tree oldop = TREE_OPERAND (t, 0); | |
3e605b20 | 4264 | tree op = cxx_eval_constant_expression (ctx, oldop, |
92a596e8 | 4265 | /*lval*/true, |
5a804683 | 4266 | non_constant_p, overflow_p); |
2d76680f PC |
4267 | /* Don't VERIFY_CONSTANT here. */ |
4268 | if (*non_constant_p) | |
4269 | return t; | |
f2acb8ad | 4270 | gcc_checking_assert (TREE_CODE (op) != CONSTRUCTOR); |
2d76680f PC |
4271 | /* This function does more aggressive folding than fold itself. */ |
4272 | r = build_fold_addr_expr_with_type (op, TREE_TYPE (t)); | |
4273 | if (TREE_CODE (r) == ADDR_EXPR && TREE_OPERAND (r, 0) == oldop) | |
4274 | return t; | |
4275 | break; | |
4276 | } | |
4277 | ||
4278 | case REALPART_EXPR: | |
4279 | case IMAGPART_EXPR: | |
87713c6a JJ |
4280 | if (lval) |
4281 | { | |
4282 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval, | |
4283 | non_constant_p, overflow_p); | |
4284 | if (r == error_mark_node) | |
4285 | ; | |
4286 | else if (r == TREE_OPERAND (t, 0)) | |
4287 | r = t; | |
4288 | else | |
4289 | r = fold_build1 (TREE_CODE (t), TREE_TYPE (t), r); | |
4290 | break; | |
4291 | } | |
4292 | /* FALLTHRU */ | |
2d76680f PC |
4293 | case CONJ_EXPR: |
4294 | case FIX_TRUNC_EXPR: | |
4295 | case FLOAT_EXPR: | |
4296 | case NEGATE_EXPR: | |
4297 | case ABS_EXPR: | |
4298 | case BIT_NOT_EXPR: | |
4299 | case TRUTH_NOT_EXPR: | |
4300 | case FIXED_CONVERT_EXPR: | |
92a596e8 | 4301 | r = cxx_eval_unary_expression (ctx, t, lval, |
2d76680f PC |
4302 | non_constant_p, overflow_p); |
4303 | break; | |
4304 | ||
4305 | case SIZEOF_EXPR: | |
cda0a029 | 4306 | r = fold_sizeof_expr (t); |
2d76680f PC |
4307 | VERIFY_CONSTANT (r); |
4308 | break; | |
4309 | ||
4310 | case COMPOUND_EXPR: | |
4311 | { | |
4312 | /* check_return_expr sometimes wraps a TARGET_EXPR in a | |
4313 | COMPOUND_EXPR; don't get confused. Also handle EMPTY_CLASS_EXPR | |
4314 | introduced by build_call_a. */ | |
4315 | tree op0 = TREE_OPERAND (t, 0); | |
4316 | tree op1 = TREE_OPERAND (t, 1); | |
4317 | STRIP_NOPS (op1); | |
4318 | if ((TREE_CODE (op0) == TARGET_EXPR && op1 == TARGET_EXPR_SLOT (op0)) | |
4319 | || TREE_CODE (op1) == EMPTY_CLASS_EXPR) | |
2b3ab879 | 4320 | r = cxx_eval_constant_expression (ctx, op0, |
92a596e8 | 4321 | lval, non_constant_p, overflow_p, |
56632b27 | 4322 | jump_target); |
2d76680f PC |
4323 | else |
4324 | { | |
4325 | /* Check that the LHS is constant and then discard it. */ | |
2b3ab879 | 4326 | cxx_eval_constant_expression (ctx, op0, |
12d9ce19 | 4327 | true, non_constant_p, overflow_p, |
56632b27 | 4328 | jump_target); |
06ec22b7 JM |
4329 | if (*non_constant_p) |
4330 | return t; | |
2d76680f | 4331 | op1 = TREE_OPERAND (t, 1); |
2b3ab879 | 4332 | r = cxx_eval_constant_expression (ctx, op1, |
92a596e8 | 4333 | lval, non_constant_p, overflow_p, |
56632b27 | 4334 | jump_target); |
2d76680f PC |
4335 | } |
4336 | } | |
4337 | break; | |
4338 | ||
4339 | case POINTER_PLUS_EXPR: | |
1af4ebf5 | 4340 | case POINTER_DIFF_EXPR: |
2d76680f PC |
4341 | case PLUS_EXPR: |
4342 | case MINUS_EXPR: | |
4343 | case MULT_EXPR: | |
4344 | case TRUNC_DIV_EXPR: | |
4345 | case CEIL_DIV_EXPR: | |
4346 | case FLOOR_DIV_EXPR: | |
4347 | case ROUND_DIV_EXPR: | |
4348 | case TRUNC_MOD_EXPR: | |
4349 | case CEIL_MOD_EXPR: | |
4350 | case ROUND_MOD_EXPR: | |
4351 | case RDIV_EXPR: | |
4352 | case EXACT_DIV_EXPR: | |
4353 | case MIN_EXPR: | |
4354 | case MAX_EXPR: | |
4355 | case LSHIFT_EXPR: | |
4356 | case RSHIFT_EXPR: | |
4357 | case LROTATE_EXPR: | |
4358 | case RROTATE_EXPR: | |
4359 | case BIT_IOR_EXPR: | |
4360 | case BIT_XOR_EXPR: | |
4361 | case BIT_AND_EXPR: | |
4362 | case TRUTH_XOR_EXPR: | |
4363 | case LT_EXPR: | |
4364 | case LE_EXPR: | |
4365 | case GT_EXPR: | |
4366 | case GE_EXPR: | |
4367 | case EQ_EXPR: | |
4368 | case NE_EXPR: | |
4369 | case UNORDERED_EXPR: | |
4370 | case ORDERED_EXPR: | |
4371 | case UNLT_EXPR: | |
4372 | case UNLE_EXPR: | |
4373 | case UNGT_EXPR: | |
4374 | case UNGE_EXPR: | |
4375 | case UNEQ_EXPR: | |
4376 | case LTGT_EXPR: | |
4377 | case RANGE_EXPR: | |
4378 | case COMPLEX_EXPR: | |
92a596e8 | 4379 | r = cxx_eval_binary_expression (ctx, t, lval, |
2d76680f PC |
4380 | non_constant_p, overflow_p); |
4381 | break; | |
4382 | ||
4383 | /* fold can introduce non-IF versions of these; still treat them as | |
4384 | short-circuiting. */ | |
4385 | case TRUTH_AND_EXPR: | |
4386 | case TRUTH_ANDIF_EXPR: | |
3e605b20 | 4387 | r = cxx_eval_logical_expression (ctx, t, boolean_false_node, |
2d76680f | 4388 | boolean_true_node, |
92a596e8 | 4389 | lval, |
2d76680f PC |
4390 | non_constant_p, overflow_p); |
4391 | break; | |
4392 | ||
4393 | case TRUTH_OR_EXPR: | |
4394 | case TRUTH_ORIF_EXPR: | |
3e605b20 | 4395 | r = cxx_eval_logical_expression (ctx, t, boolean_true_node, |
2d76680f | 4396 | boolean_false_node, |
92a596e8 | 4397 | lval, |
2d76680f PC |
4398 | non_constant_p, overflow_p); |
4399 | break; | |
4400 | ||
4401 | case ARRAY_REF: | |
92a596e8 | 4402 | r = cxx_eval_array_reference (ctx, t, lval, |
2d76680f PC |
4403 | non_constant_p, overflow_p); |
4404 | break; | |
4405 | ||
4406 | case COMPONENT_REF: | |
4407 | if (is_overloaded_fn (t)) | |
4408 | { | |
4409 | /* We can only get here in checking mode via | |
4410 | build_non_dependent_expr, because any expression that | |
4411 | calls or takes the address of the function will have | |
4412 | pulled a FUNCTION_DECL out of the COMPONENT_REF. */ | |
2b3ab879 | 4413 | gcc_checking_assert (ctx->quiet || errorcount); |
2d76680f PC |
4414 | *non_constant_p = true; |
4415 | return t; | |
4416 | } | |
92a596e8 | 4417 | r = cxx_eval_component_reference (ctx, t, lval, |
2d76680f PC |
4418 | non_constant_p, overflow_p); |
4419 | break; | |
4420 | ||
4421 | case BIT_FIELD_REF: | |
92a596e8 | 4422 | r = cxx_eval_bit_field_ref (ctx, t, lval, |
2d76680f PC |
4423 | non_constant_p, overflow_p); |
4424 | break; | |
4425 | ||
4426 | case COND_EXPR: | |
4b390698 JJ |
4427 | if (jump_target && *jump_target) |
4428 | { | |
4429 | /* When jumping to a label, the label might be either in the | |
4430 | then or else blocks, so process then block first in skipping | |
4431 | mode first, and if we are still in the skipping mode at its end, | |
4432 | process the else block too. */ | |
4433 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), | |
4434 | lval, non_constant_p, overflow_p, | |
4435 | jump_target); | |
4436 | if (*jump_target) | |
4437 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 2), | |
4438 | lval, non_constant_p, overflow_p, | |
4439 | jump_target); | |
4440 | break; | |
4441 | } | |
92a596e8 | 4442 | r = cxx_eval_conditional_expression (ctx, t, lval, |
56632b27 JM |
4443 | non_constant_p, overflow_p, |
4444 | jump_target); | |
2d76680f | 4445 | break; |
f370e36d JJ |
4446 | case VEC_COND_EXPR: |
4447 | r = cxx_eval_vector_conditional_expression (ctx, t, non_constant_p, | |
4448 | overflow_p); | |
4449 | break; | |
2d76680f PC |
4450 | |
4451 | case CONSTRUCTOR: | |
b85a3242 | 4452 | if (TREE_CONSTANT (t)) |
2d63bc39 JM |
4453 | { |
4454 | /* Don't re-process a constant CONSTRUCTOR, but do fold it to | |
4455 | VECTOR_CST if applicable. */ | |
4456 | /* FIXME after GCC 6 branches, make the verify unconditional. */ | |
4457 | if (CHECKING_P) | |
4458 | verify_constructor_flags (t); | |
4459 | else | |
4460 | recompute_constructor_flags (t); | |
4461 | if (TREE_CONSTANT (t)) | |
4462 | return fold (t); | |
4463 | } | |
92a596e8 | 4464 | r = cxx_eval_bare_aggregate (ctx, t, lval, |
2d76680f PC |
4465 | non_constant_p, overflow_p); |
4466 | break; | |
4467 | ||
4468 | case VEC_INIT_EXPR: | |
4469 | /* We can get this in a defaulted constructor for a class with a | |
4470 | non-static data member of array type. Either the initializer will | |
4471 | be NULL, meaning default-initialization, or it will be an lvalue | |
4472 | or xvalue of the same type, meaning direct-initialization from the | |
4473 | corresponding member. */ | |
92a596e8 | 4474 | r = cxx_eval_vec_init (ctx, t, lval, |
2d76680f PC |
4475 | non_constant_p, overflow_p); |
4476 | break; | |
4477 | ||
4478 | case FMA_EXPR: | |
4479 | case VEC_PERM_EXPR: | |
92a596e8 | 4480 | r = cxx_eval_trinary_expression (ctx, t, lval, |
2d76680f PC |
4481 | non_constant_p, overflow_p); |
4482 | break; | |
4483 | ||
4484 | case CONVERT_EXPR: | |
4485 | case VIEW_CONVERT_EXPR: | |
4486 | case NOP_EXPR: | |
cda0a029 | 4487 | case UNARY_PLUS_EXPR: |
2d76680f PC |
4488 | { |
4489 | tree oldop = TREE_OPERAND (t, 0); | |
cda0a029 | 4490 | |
3e605b20 | 4491 | tree op = cxx_eval_constant_expression (ctx, oldop, |
92a596e8 | 4492 | lval, |
5a804683 | 4493 | non_constant_p, overflow_p); |
2d76680f PC |
4494 | if (*non_constant_p) |
4495 | return t; | |
dcdbc004 JM |
4496 | tree type = TREE_TYPE (t); |
4497 | if (TREE_CODE (op) == PTRMEM_CST | |
4498 | && !TYPE_PTRMEM_P (type)) | |
4499 | op = cplus_expand_constant (op); | |
05bf54c3 MP |
4500 | if (TREE_CODE (op) == PTRMEM_CST && tcode == NOP_EXPR) |
4501 | { | |
4502 | if (same_type_ignoring_top_level_qualifiers_p (type, | |
8b8b203a JM |
4503 | TREE_TYPE (op)) |
4504 | || can_convert_qual (type, op)) | |
f9438bbb | 4505 | return cp_fold_convert (type, op); |
05bf54c3 MP |
4506 | else |
4507 | { | |
4508 | if (!ctx->quiet) | |
4509 | error_at (EXPR_LOC_OR_LOC (t, input_location), | |
64d6d399 | 4510 | "a reinterpret_cast is not a constant expression"); |
05bf54c3 MP |
4511 | *non_constant_p = true; |
4512 | return t; | |
4513 | } | |
4514 | } | |
8bada5cd MS |
4515 | |
4516 | if (POINTER_TYPE_P (type) && TREE_CODE (op) == INTEGER_CST) | |
2d76680f | 4517 | { |
8bada5cd MS |
4518 | if (integer_zerop (op)) |
4519 | { | |
4520 | if (TREE_CODE (type) == REFERENCE_TYPE) | |
4521 | { | |
4522 | if (!ctx->quiet) | |
4523 | error_at (EXPR_LOC_OR_LOC (t, input_location), | |
4524 | "dereferencing a null pointer"); | |
4525 | *non_constant_p = true; | |
4526 | return t; | |
4527 | } | |
4528 | else if (TREE_CODE (TREE_TYPE (op)) == POINTER_TYPE) | |
4529 | { | |
4530 | tree from = TREE_TYPE (op); | |
4531 | ||
4532 | if (!can_convert (type, from, tf_none)) | |
4533 | { | |
4534 | if (!ctx->quiet) | |
4535 | error_at (EXPR_LOC_OR_LOC (t, input_location), | |
4536 | "conversion of %qT null pointer to %qT " | |
4537 | "is not a constant expression", | |
4538 | from, type); | |
4539 | *non_constant_p = true; | |
4540 | return t; | |
4541 | } | |
4542 | } | |
4543 | } | |
4544 | else | |
4545 | { | |
4546 | /* This detects for example: | |
4547 | reinterpret_cast<void*>(sizeof 0) | |
4548 | */ | |
4549 | if (!ctx->quiet) | |
4550 | error_at (EXPR_LOC_OR_LOC (t, input_location), | |
4551 | "%<reinterpret_cast<%T>(%E)%> is not " | |
64d6d399 | 4552 | "a constant expression", |
8bada5cd MS |
4553 | type, op); |
4554 | *non_constant_p = true; | |
4555 | return t; | |
4556 | } | |
2d76680f | 4557 | } |
cda0a029 | 4558 | if (op == oldop && tcode != UNARY_PLUS_EXPR) |
2d76680f PC |
4559 | /* We didn't fold at the top so we could check for ptr-int |
4560 | conversion. */ | |
4561 | return fold (t); | |
cda0a029 JM |
4562 | if (tcode == UNARY_PLUS_EXPR) |
4563 | r = fold_convert (TREE_TYPE (t), op); | |
4564 | else | |
4565 | r = fold_build1 (tcode, type, op); | |
2d76680f PC |
4566 | /* Conversion of an out-of-range value has implementation-defined |
4567 | behavior; the language considers it different from arithmetic | |
4568 | overflow, which is undefined. */ | |
4569 | if (TREE_OVERFLOW_P (r) && !TREE_OVERFLOW_P (op)) | |
4570 | TREE_OVERFLOW (r) = false; | |
4571 | } | |
4572 | break; | |
4573 | ||
4574 | case EMPTY_CLASS_EXPR: | |
4575 | /* This is good enough for a function argument that might not get | |
4576 | used, and they can't do anything with it, so just return it. */ | |
4577 | return t; | |
4578 | ||
60813a46 | 4579 | case STATEMENT_LIST: |
56632b27 JM |
4580 | new_ctx = *ctx; |
4581 | new_ctx.ctor = new_ctx.object = NULL_TREE; | |
2b3ab879 | 4582 | return cxx_eval_statement_list (&new_ctx, t, |
56632b27 | 4583 | non_constant_p, overflow_p, jump_target); |
60813a46 JM |
4584 | |
4585 | case BIND_EXPR: | |
4586 | return cxx_eval_constant_expression (ctx, BIND_EXPR_BODY (t), | |
92a596e8 | 4587 | lval, |
56632b27 JM |
4588 | non_constant_p, overflow_p, |
4589 | jump_target); | |
60813a46 | 4590 | |
2d76680f PC |
4591 | case PREINCREMENT_EXPR: |
4592 | case POSTINCREMENT_EXPR: | |
4593 | case PREDECREMENT_EXPR: | |
4594 | case POSTDECREMENT_EXPR: | |
2b3ab879 | 4595 | return cxx_eval_increment_expression (ctx, t, |
92a596e8 | 4596 | lval, non_constant_p, overflow_p); |
60813a46 JM |
4597 | |
4598 | case LAMBDA_EXPR: | |
2d76680f PC |
4599 | case NEW_EXPR: |
4600 | case VEC_NEW_EXPR: | |
4601 | case DELETE_EXPR: | |
4602 | case VEC_DELETE_EXPR: | |
4603 | case THROW_EXPR: | |
2d76680f PC |
4604 | case MODOP_EXPR: |
4605 | /* GCC internal stuff. */ | |
4606 | case VA_ARG_EXPR: | |
4607 | case OBJ_TYPE_REF: | |
2d76680f PC |
4608 | case NON_DEPENDENT_EXPR: |
4609 | case BASELINK: | |
2d76680f | 4610 | case OFFSET_REF: |
2b3ab879 | 4611 | if (!ctx->quiet) |
2d76680f | 4612 | error_at (EXPR_LOC_OR_LOC (t, input_location), |
64d6d399 | 4613 | "expression %qE is not a constant expression", t); |
2d76680f PC |
4614 | *non_constant_p = true; |
4615 | break; | |
4616 | ||
3e605b20 | 4617 | case PLACEHOLDER_EXPR: |
89262ec6 JM |
4618 | /* Use of the value or address of the current object. */ |
4619 | if (tree ctor = lookup_placeholder (ctx, lval, TREE_TYPE (t))) | |
4620 | return cxx_eval_constant_expression (ctx, ctor, lval, | |
4621 | non_constant_p, overflow_p); | |
4622 | /* A placeholder without a referent. We can get here when | |
4623 | checking whether NSDMIs are noexcept, or in massage_init_elt; | |
4624 | just say it's non-constant for now. */ | |
4625 | gcc_assert (ctx->quiet); | |
4626 | *non_constant_p = true; | |
3e605b20 JM |
4627 | break; |
4628 | ||
06ec22b7 JM |
4629 | case EXIT_EXPR: |
4630 | { | |
4631 | tree cond = TREE_OPERAND (t, 0); | |
4632 | cond = cxx_eval_constant_expression (ctx, cond, /*lval*/false, | |
4633 | non_constant_p, overflow_p); | |
4634 | VERIFY_CONSTANT (cond); | |
4635 | if (integer_nonzerop (cond)) | |
4636 | *jump_target = t; | |
4637 | } | |
4638 | break; | |
4639 | ||
60813a46 | 4640 | case GOTO_EXPR: |
56632b27 | 4641 | *jump_target = TREE_OPERAND (t, 0); |
d49318d9 PC |
4642 | gcc_assert (breaks (jump_target) || continues (jump_target) |
4643 | /* Allow for jumping to a cdtor_label. */ | |
4644 | || returns (jump_target)); | |
56632b27 JM |
4645 | break; |
4646 | ||
60813a46 | 4647 | case LOOP_EXPR: |
2b3ab879 | 4648 | cxx_eval_loop_expr (ctx, t, |
56632b27 JM |
4649 | non_constant_p, overflow_p, jump_target); |
4650 | break; | |
4651 | ||
60813a46 | 4652 | case SWITCH_EXPR: |
2b3ab879 | 4653 | cxx_eval_switch_expr (ctx, t, |
56632b27 | 4654 | non_constant_p, overflow_p, jump_target); |
60813a46 JM |
4655 | break; |
4656 | ||
971e17ff AS |
4657 | case REQUIRES_EXPR: |
4658 | /* It's possible to get a requires-expression in a constant | |
4659 | expression. For example: | |
4660 | ||
4661 | template<typename T> concept bool C() { | |
4662 | return requires (T t) { t; }; | |
4663 | } | |
4664 | ||
4665 | template<typename T> requires !C<T>() void f(T); | |
4666 | ||
4667 | Normalization leaves f with the associated constraint | |
4668 | '!requires (T t) { ... }' which is not transformed into | |
4669 | a constraint. */ | |
4670 | if (!processing_template_decl) | |
4671 | return evaluate_constraint_expression (t, NULL_TREE); | |
4672 | else | |
4673 | *non_constant_p = true; | |
4674 | return t; | |
4675 | ||
98e09245 JJ |
4676 | case ANNOTATE_EXPR: |
4677 | gcc_assert (tree_to_uhwi (TREE_OPERAND (t, 1)) == annot_expr_ivdep_kind); | |
4678 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), | |
4679 | lval, | |
4680 | non_constant_p, overflow_p, | |
4681 | jump_target); | |
4682 | break; | |
4683 | ||
2d76680f | 4684 | default: |
c6e7c499 JM |
4685 | if (STATEMENT_CODE_P (TREE_CODE (t))) |
4686 | { | |
4687 | /* This function doesn't know how to deal with pre-genericize | |
4688 | statements; this can only happen with statement-expressions, | |
4689 | so for now just fail. */ | |
4690 | if (!ctx->quiet) | |
4691 | error_at (EXPR_LOCATION (t), | |
64d6d399 | 4692 | "statement is not a constant expression"); |
c6e7c499 JM |
4693 | } |
4694 | else | |
4695 | internal_error ("unexpected expression %qE of kind %s", t, | |
4696 | get_tree_code_name (TREE_CODE (t))); | |
2d76680f PC |
4697 | *non_constant_p = true; |
4698 | break; | |
4699 | } | |
4700 | ||
4701 | if (r == error_mark_node) | |
4702 | *non_constant_p = true; | |
4703 | ||
4704 | if (*non_constant_p) | |
4705 | return t; | |
4706 | else | |
4707 | return r; | |
4708 | } | |
4709 | ||
4710 | static tree | |
3e605b20 | 4711 | cxx_eval_outermost_constant_expr (tree t, bool allow_non_constant, |
69eb4fde | 4712 | bool strict = true, tree object = NULL_TREE) |
2d76680f | 4713 | { |
8108ea30 JM |
4714 | auto_timevar time (TV_CONSTEXPR); |
4715 | ||
2d76680f PC |
4716 | bool non_constant_p = false; |
4717 | bool overflow_p = false; | |
3e605b20 | 4718 | hash_map<tree,tree> map; |
39dce2b7 | 4719 | |
4b390698 | 4720 | constexpr_ctx ctx = { NULL, &map, NULL, NULL, NULL, NULL, |
39dce2b7 JM |
4721 | allow_non_constant, strict }; |
4722 | ||
3e605b20 | 4723 | tree type = initialized_type (t); |
3e605b20 JM |
4724 | tree r = t; |
4725 | if (AGGREGATE_TYPE_P (type) || VECTOR_TYPE_P (type)) | |
4726 | { | |
4727 | /* In C++14 an NSDMI can participate in aggregate initialization, | |
4728 | and can refer to the address of the object being initialized, so | |
4729 | we need to pass in the relevant VAR_DECL if we want to do the | |
4730 | evaluation in a single pass. The evaluation will dynamically | |
4731 | update ctx.values for the VAR_DECL. We use the same strategy | |
4732 | for C++11 constexpr constructors that refer to the object being | |
4733 | initialized. */ | |
4734 | ctx.ctor = build_constructor (type, NULL); | |
4735 | CONSTRUCTOR_NO_IMPLICIT_ZERO (ctx.ctor) = true; | |
60813a46 JM |
4736 | if (!object) |
4737 | { | |
4738 | if (TREE_CODE (t) == TARGET_EXPR) | |
4739 | object = TARGET_EXPR_SLOT (t); | |
4740 | else if (TREE_CODE (t) == AGGR_INIT_EXPR) | |
4741 | object = AGGR_INIT_EXPR_SLOT (t); | |
4742 | } | |
3e605b20 JM |
4743 | ctx.object = object; |
4744 | if (object) | |
4745 | gcc_assert (same_type_ignoring_top_level_qualifiers_p | |
4746 | (type, TREE_TYPE (object))); | |
4747 | if (object && DECL_P (object)) | |
4748 | map.put (object, ctx.ctor); | |
4749 | if (TREE_CODE (r) == TARGET_EXPR) | |
4750 | /* Avoid creating another CONSTRUCTOR when we expand the | |
4751 | TARGET_EXPR. */ | |
4752 | r = TARGET_EXPR_INITIAL (r); | |
4753 | } | |
4754 | ||
2b3ab879 | 4755 | r = cxx_eval_constant_expression (&ctx, r, |
5a804683 | 4756 | false, &non_constant_p, &overflow_p); |
2d76680f PC |
4757 | |
4758 | verify_constant (r, allow_non_constant, &non_constant_p, &overflow_p); | |
4759 | ||
023d89c7 JM |
4760 | /* Mutable logic is a bit tricky: we want to allow initialization of |
4761 | constexpr variables with mutable members, but we can't copy those | |
4762 | members to another constexpr variable. */ | |
4763 | if (TREE_CODE (r) == CONSTRUCTOR | |
4764 | && CONSTRUCTOR_MUTABLE_POISON (r)) | |
2d76680f | 4765 | { |
2d76680f | 4766 | if (!allow_non_constant) |
023d89c7 JM |
4767 | error ("%qE is not a constant expression because it refers to " |
4768 | "mutable subobjects of %qT", t, type); | |
2d76680f PC |
4769 | non_constant_p = true; |
4770 | } | |
4771 | ||
f64e0c02 JM |
4772 | if (TREE_CODE (r) == CONSTRUCTOR |
4773 | && CONSTRUCTOR_NO_IMPLICIT_ZERO (r)) | |
4774 | { | |
4775 | if (!allow_non_constant) | |
4776 | error ("%qE is not a constant expression because it refers to " | |
4777 | "an incompletely initialized variable", t); | |
4778 | TREE_CONSTANT (r) = false; | |
4779 | non_constant_p = true; | |
4780 | } | |
4781 | ||
2d76680f PC |
4782 | /* Technically we should check this for all subexpressions, but that |
4783 | runs into problems with our internal representation of pointer | |
4784 | subtraction and the 5.19 rules are still in flux. */ | |
4785 | if (CONVERT_EXPR_CODE_P (TREE_CODE (r)) | |
4786 | && ARITHMETIC_TYPE_P (TREE_TYPE (r)) | |
4787 | && TREE_CODE (TREE_OPERAND (r, 0)) == ADDR_EXPR) | |
4788 | { | |
4789 | if (!allow_non_constant) | |
4790 | error ("conversion from pointer type %qT " | |
64d6d399 | 4791 | "to arithmetic type %qT in a constant expression", |
2d76680f PC |
4792 | TREE_TYPE (TREE_OPERAND (r, 0)), TREE_TYPE (r)); |
4793 | non_constant_p = true; | |
4794 | } | |
4795 | ||
4796 | if (!non_constant_p && overflow_p) | |
4797 | non_constant_p = true; | |
4798 | ||
56cfb596 PP |
4799 | /* Unshare the result unless it's a CONSTRUCTOR in which case it's already |
4800 | unshared. */ | |
4801 | bool should_unshare = true; | |
4802 | if (r == t || TREE_CODE (r) == CONSTRUCTOR) | |
4803 | should_unshare = false; | |
4804 | ||
2d76680f PC |
4805 | if (non_constant_p && !allow_non_constant) |
4806 | return error_mark_node; | |
4807 | else if (non_constant_p && TREE_CONSTANT (r)) | |
4808 | { | |
4809 | /* This isn't actually constant, so unset TREE_CONSTANT. */ | |
4810 | if (EXPR_P (r)) | |
4811 | r = copy_node (r); | |
4812 | else if (TREE_CODE (r) == CONSTRUCTOR) | |
4813 | r = build1 (VIEW_CONVERT_EXPR, TREE_TYPE (r), r); | |
4814 | else | |
4815 | r = build_nop (TREE_TYPE (r), r); | |
4816 | TREE_CONSTANT (r) = false; | |
4817 | } | |
4818 | else if (non_constant_p || r == t) | |
4819 | return t; | |
4820 | ||
56cfb596 PP |
4821 | if (should_unshare) |
4822 | r = unshare_expr (r); | |
4823 | ||
2d76680f PC |
4824 | if (TREE_CODE (r) == CONSTRUCTOR && CLASS_TYPE_P (TREE_TYPE (r))) |
4825 | { | |
4826 | if (TREE_CODE (t) == TARGET_EXPR | |
4827 | && TARGET_EXPR_INITIAL (t) == r) | |
4828 | return t; | |
4829 | else | |
4830 | { | |
4831 | r = get_target_expr (r); | |
4832 | TREE_CONSTANT (r) = true; | |
4833 | return r; | |
4834 | } | |
4835 | } | |
4836 | else | |
4837 | return r; | |
4838 | } | |
4839 | ||
4840 | /* Returns true if T is a valid subexpression of a constant expression, | |
4841 | even if it isn't itself a constant expression. */ | |
4842 | ||
4843 | bool | |
4844 | is_sub_constant_expr (tree t) | |
4845 | { | |
4846 | bool non_constant_p = false; | |
4847 | bool overflow_p = false; | |
3e605b20 | 4848 | hash_map <tree, tree> map; |
39dce2b7 | 4849 | |
4b390698 | 4850 | constexpr_ctx ctx = { NULL, &map, NULL, NULL, NULL, NULL, true, true }; |
39dce2b7 | 4851 | |
2b3ab879 | 4852 | cxx_eval_constant_expression (&ctx, t, false, &non_constant_p, |
5a804683 | 4853 | &overflow_p); |
2d76680f PC |
4854 | return !non_constant_p && !overflow_p; |
4855 | } | |
4856 | ||
4857 | /* If T represents a constant expression returns its reduced value. | |
4858 | Otherwise return error_mark_node. If T is dependent, then | |
4859 | return NULL. */ | |
4860 | ||
4861 | tree | |
3e605b20 | 4862 | cxx_constant_value (tree t, tree decl) |
2d76680f | 4863 | { |
69eb4fde | 4864 | return cxx_eval_outermost_constant_expr (t, false, true, decl); |
2d76680f PC |
4865 | } |
4866 | ||
cda0a029 JM |
4867 | /* Helper routine for fold_simple function. Either return simplified |
4868 | expression T, otherwise NULL_TREE. | |
4869 | In contrast to cp_fully_fold, and to maybe_constant_value, we try to fold | |
4870 | even if we are within template-declaration. So be careful on call, as in | |
4871 | such case types can be undefined. */ | |
4872 | ||
4873 | static tree | |
4874 | fold_simple_1 (tree t) | |
4875 | { | |
4876 | tree op1; | |
4877 | enum tree_code code = TREE_CODE (t); | |
4878 | ||
4879 | switch (code) | |
4880 | { | |
4881 | case INTEGER_CST: | |
4882 | case REAL_CST: | |
4883 | case VECTOR_CST: | |
4884 | case FIXED_CST: | |
4885 | case COMPLEX_CST: | |
4886 | return t; | |
4887 | ||
4888 | case SIZEOF_EXPR: | |
4889 | return fold_sizeof_expr (t); | |
4890 | ||
4891 | case ABS_EXPR: | |
4892 | case CONJ_EXPR: | |
4893 | case REALPART_EXPR: | |
4894 | case IMAGPART_EXPR: | |
4895 | case NEGATE_EXPR: | |
4896 | case BIT_NOT_EXPR: | |
4897 | case TRUTH_NOT_EXPR: | |
4898 | case NOP_EXPR: | |
4899 | case VIEW_CONVERT_EXPR: | |
4900 | case CONVERT_EXPR: | |
4901 | case FLOAT_EXPR: | |
4902 | case FIX_TRUNC_EXPR: | |
4903 | case FIXED_CONVERT_EXPR: | |
4904 | case ADDR_SPACE_CONVERT_EXPR: | |
4905 | ||
4906 | op1 = TREE_OPERAND (t, 0); | |
4907 | ||
4908 | t = const_unop (code, TREE_TYPE (t), op1); | |
4909 | if (!t) | |
4910 | return NULL_TREE; | |
4911 | ||
4912 | if (CONVERT_EXPR_CODE_P (code) | |
4913 | && TREE_OVERFLOW_P (t) && !TREE_OVERFLOW_P (op1)) | |
4914 | TREE_OVERFLOW (t) = false; | |
4915 | return t; | |
4916 | ||
4917 | default: | |
4918 | return NULL_TREE; | |
4919 | } | |
4920 | } | |
4921 | ||
4922 | /* If T is a simple constant expression, returns its simplified value. | |
4923 | Otherwise returns T. In contrast to maybe_constant_value do we | |
4924 | simplify only few operations on constant-expressions, and we don't | |
4925 | try to simplify constexpressions. */ | |
4926 | ||
4927 | tree | |
4928 | fold_simple (tree t) | |
4929 | { | |
4930 | tree r = NULL_TREE; | |
4931 | if (processing_template_decl) | |
4932 | return t; | |
4933 | ||
4934 | r = fold_simple_1 (t); | |
4935 | if (!r) | |
4936 | r = t; | |
4937 | ||
4938 | return r; | |
4939 | } | |
4940 | ||
2d76680f PC |
4941 | /* If T is a constant expression, returns its reduced value. |
4942 | Otherwise, if T does not have TREE_CONSTANT set, returns T. | |
4943 | Otherwise, returns a version of T without TREE_CONSTANT. */ | |
4944 | ||
8a87daca JM |
4945 | static GTY((deletable)) hash_map<tree, tree> *cv_cache; |
4946 | ||
4947 | tree | |
4948 | maybe_constant_value (tree t, tree decl) | |
2d76680f PC |
4949 | { |
4950 | tree r; | |
4951 | ||
a0ab7ccd | 4952 | if (!is_nondependent_constant_expression (t)) |
2d76680f PC |
4953 | { |
4954 | if (TREE_OVERFLOW_P (t)) | |
4955 | { | |
4956 | t = build_nop (TREE_TYPE (t), t); | |
4957 | TREE_CONSTANT (t) = false; | |
4958 | } | |
4959 | return t; | |
4960 | } | |
8a87daca JM |
4961 | else if (CONSTANT_CLASS_P (t)) |
4962 | /* No caching or evaluation needed. */ | |
4963 | return t; | |
4964 | ||
4965 | if (cv_cache == NULL) | |
4966 | cv_cache = hash_map<tree, tree>::create_ggc (101); | |
4967 | if (tree *cached = cv_cache->get (t)) | |
4968 | return *cached; | |
2d76680f | 4969 | |
69eb4fde | 4970 | r = cxx_eval_outermost_constant_expr (t, true, true, decl); |
595278be MM |
4971 | gcc_checking_assert (r == t |
4972 | || CONVERT_EXPR_P (t) | |
4973 | || TREE_CODE (t) == VIEW_CONVERT_EXPR | |
4974 | || (TREE_CONSTANT (t) && !TREE_CONSTANT (r)) | |
4975 | || !cp_tree_equal (r, t)); | |
8a87daca | 4976 | cv_cache->put (t, r); |
2d76680f PC |
4977 | return r; |
4978 | } | |
4979 | ||
7a7ac32a PP |
4980 | /* Dispose of the whole CV_CACHE. */ |
4981 | ||
4982 | static void | |
4983 | clear_cv_cache (void) | |
4984 | { | |
4985 | if (cv_cache != NULL) | |
4986 | cv_cache->empty (); | |
4987 | } | |
4988 | ||
eba9e839 | 4989 | /* Dispose of the whole CV_CACHE and FOLD_CACHE. */ |
1e297006 MP |
4990 | |
4991 | void | |
eba9e839 | 4992 | clear_cv_and_fold_caches (void) |
1e297006 | 4993 | { |
7a7ac32a | 4994 | clear_cv_cache (); |
eba9e839 | 4995 | clear_fold_cache (); |
1e297006 MP |
4996 | } |
4997 | ||
234bef96 PC |
4998 | /* Like maybe_constant_value but first fully instantiate the argument. |
4999 | ||
5000 | Note: this is equivalent to instantiate_non_dependent_expr_sfinae | |
5001 | (t, tf_none) followed by maybe_constant_value but is more efficient, | |
5002 | because calls instantiation_dependent_expression_p and | |
5003 | potential_constant_expression at most once. */ | |
5004 | ||
5005 | tree | |
5006 | fold_non_dependent_expr (tree t) | |
5007 | { | |
5008 | if (t == NULL_TREE) | |
5009 | return NULL_TREE; | |
5010 | ||
5011 | /* If we're in a template, but T isn't value dependent, simplify | |
5012 | it. We're supposed to treat: | |
5013 | ||
5014 | template <typename T> void f(T[1 + 1]); | |
5015 | template <typename T> void f(T[2]); | |
5016 | ||
5017 | as two declarations of the same function, for example. */ | |
5018 | if (processing_template_decl) | |
5019 | { | |
a0ab7ccd | 5020 | if (is_nondependent_constant_expression (t)) |
234bef96 | 5021 | { |
1b5695e6 JM |
5022 | processing_template_decl_sentinel s; |
5023 | t = instantiate_non_dependent_expr_internal (t, tf_none); | |
234bef96 PC |
5024 | |
5025 | if (type_unknown_p (t) | |
5026 | || BRACE_ENCLOSED_INITIALIZER_P (t)) | |
5027 | { | |
5028 | if (TREE_OVERFLOW_P (t)) | |
5029 | { | |
5030 | t = build_nop (TREE_TYPE (t), t); | |
5031 | TREE_CONSTANT (t) = false; | |
5032 | } | |
5033 | return t; | |
5034 | } | |
5035 | ||
69eb4fde | 5036 | tree r = cxx_eval_outermost_constant_expr (t, true, true, NULL_TREE); |
234bef96 | 5037 | /* cp_tree_equal looks through NOPs, so allow them. */ |
595278be MM |
5038 | gcc_checking_assert (r == t |
5039 | || CONVERT_EXPR_P (t) | |
5040 | || TREE_CODE (t) == VIEW_CONVERT_EXPR | |
5041 | || (TREE_CONSTANT (t) && !TREE_CONSTANT (r)) | |
5042 | || !cp_tree_equal (r, t)); | |
234bef96 PC |
5043 | return r; |
5044 | } | |
5045 | else if (TREE_OVERFLOW_P (t)) | |
5046 | { | |
5047 | t = build_nop (TREE_TYPE (t), t); | |
5048 | TREE_CONSTANT (t) = false; | |
5049 | } | |
5050 | return t; | |
5051 | } | |
5052 | ||
5053 | return maybe_constant_value (t); | |
5054 | } | |
5055 | ||
2d76680f PC |
5056 | /* Like maybe_constant_value, but returns a CONSTRUCTOR directly, rather |
5057 | than wrapped in a TARGET_EXPR. */ | |
5058 | ||
5059 | tree | |
3e605b20 | 5060 | maybe_constant_init (tree t, tree decl) |
2d76680f | 5061 | { |
cda0a029 JM |
5062 | if (!t) |
5063 | return t; | |
2d76680f PC |
5064 | if (TREE_CODE (t) == EXPR_STMT) |
5065 | t = TREE_OPERAND (t, 0); | |
5066 | if (TREE_CODE (t) == CONVERT_EXPR | |
5067 | && VOID_TYPE_P (TREE_TYPE (t))) | |
5068 | t = TREE_OPERAND (t, 0); | |
60813a46 JM |
5069 | if (TREE_CODE (t) == INIT_EXPR) |
5070 | t = TREE_OPERAND (t, 1); | |
f64e0c02 JM |
5071 | if (TREE_CODE (t) == TARGET_EXPR) |
5072 | t = TARGET_EXPR_INITIAL (t); | |
a0ab7ccd | 5073 | if (!is_nondependent_static_init_expression (t)) |
69eb4fde | 5074 | /* Don't try to evaluate it. */; |
8a87daca JM |
5075 | else if (CONSTANT_CLASS_P (t)) |
5076 | /* No evaluation needed. */; | |
69eb4fde JM |
5077 | else |
5078 | t = cxx_eval_outermost_constant_expr (t, true, false, decl); | |
2d76680f PC |
5079 | if (TREE_CODE (t) == TARGET_EXPR) |
5080 | { | |
5081 | tree init = TARGET_EXPR_INITIAL (t); | |
5082 | if (TREE_CODE (init) == CONSTRUCTOR) | |
5083 | t = init; | |
5084 | } | |
5085 | return t; | |
5086 | } | |
5087 | ||
5088 | #if 0 | |
5089 | /* FIXME see ADDR_EXPR section in potential_constant_expression_1. */ | |
5090 | /* Return true if the object referred to by REF has automatic or thread | |
5091 | local storage. */ | |
5092 | ||
5093 | enum { ck_ok, ck_bad, ck_unknown }; | |
5094 | static int | |
5095 | check_automatic_or_tls (tree ref) | |
5096 | { | |
ef4bddc2 | 5097 | machine_mode mode; |
2d76680f PC |
5098 | HOST_WIDE_INT bitsize, bitpos; |
5099 | tree offset; | |
5100 | int volatilep = 0, unsignedp = 0; | |
5101 | tree decl = get_inner_reference (ref, &bitsize, &bitpos, &offset, | |
5102 | &mode, &unsignedp, &volatilep, false); | |
5103 | duration_kind dk; | |
5104 | ||
5105 | /* If there isn't a decl in the middle, we don't know the linkage here, | |
5106 | and this isn't a constant expression anyway. */ | |
5107 | if (!DECL_P (decl)) | |
5108 | return ck_unknown; | |
5109 | dk = decl_storage_duration (decl); | |
5110 | return (dk == dk_auto || dk == dk_thread) ? ck_bad : ck_ok; | |
5111 | } | |
5112 | #endif | |
5113 | ||
5114 | /* Return true if T denotes a potentially constant expression. Issue | |
5115 | diagnostic as appropriate under control of FLAGS. If WANT_RVAL is true, | |
a0ab7ccd JM |
5116 | an lvalue-rvalue conversion is implied. If NOW is true, we want to |
5117 | consider the expression in the current context, independent of constexpr | |
5118 | substitution. | |
2d76680f PC |
5119 | |
5120 | C++0x [expr.const] used to say | |
5121 | ||
5122 | 6 An expression is a potential constant expression if it is | |
5123 | a constant expression where all occurrences of function | |
5124 | parameters are replaced by arbitrary constant expressions | |
5125 | of the appropriate type. | |
5126 | ||
5127 | 2 A conditional expression is a constant expression unless it | |
5128 | involves one of the following as a potentially evaluated | |
5129 | subexpression (3.2), but subexpressions of logical AND (5.14), | |
5130 | logical OR (5.15), and conditional (5.16) operations that are | |
5131 | not evaluated are not considered. */ | |
5132 | ||
5133 | static bool | |
a0ab7ccd | 5134 | potential_constant_expression_1 (tree t, bool want_rval, bool strict, bool now, |
69eb4fde | 5135 | tsubst_flags_t flags) |
2d76680f | 5136 | { |
a0ab7ccd JM |
5137 | #define RECUR(T,RV) \ |
5138 | potential_constant_expression_1 ((T), (RV), strict, now, flags) | |
5139 | ||
2d76680f PC |
5140 | enum { any = false, rval = true }; |
5141 | int i; | |
5142 | tree tmp; | |
5143 | ||
5144 | if (t == error_mark_node) | |
5145 | return false; | |
5146 | if (t == NULL_TREE) | |
5147 | return true; | |
e40b6fc7 | 5148 | location_t loc = EXPR_LOC_OR_LOC (t, input_location); |
19dedccf | 5149 | if (TREE_THIS_VOLATILE (t) && !DECL_P (t)) |
2d76680f PC |
5150 | { |
5151 | if (flags & tf_error) | |
e40b6fc7 | 5152 | error_at (loc, "expression %qE has side-effects", t); |
2d76680f PC |
5153 | return false; |
5154 | } | |
5155 | if (CONSTANT_CLASS_P (t)) | |
5156 | return true; | |
7dc2b4a2 JM |
5157 | if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_TYPED) |
5158 | && TREE_TYPE (t) == error_mark_node) | |
5159 | return false; | |
2d76680f PC |
5160 | |
5161 | switch (TREE_CODE (t)) | |
5162 | { | |
5163 | case FUNCTION_DECL: | |
5164 | case BASELINK: | |
5165 | case TEMPLATE_DECL: | |
5166 | case OVERLOAD: | |
5167 | case TEMPLATE_ID_EXPR: | |
5168 | case LABEL_DECL: | |
5169 | case LABEL_EXPR: | |
60813a46 | 5170 | case CASE_LABEL_EXPR: |
2d76680f PC |
5171 | case CONST_DECL: |
5172 | case SIZEOF_EXPR: | |
5173 | case ALIGNOF_EXPR: | |
5174 | case OFFSETOF_EXPR: | |
5175 | case NOEXCEPT_EXPR: | |
5176 | case TEMPLATE_PARM_INDEX: | |
5177 | case TRAIT_EXPR: | |
5178 | case IDENTIFIER_NODE: | |
5179 | case USERDEF_LITERAL: | |
5180 | /* We can see a FIELD_DECL in a pointer-to-member expression. */ | |
5181 | case FIELD_DECL: | |
cda0a029 | 5182 | case RESULT_DECL: |
2d76680f | 5183 | case USING_DECL: |
60813a46 | 5184 | case USING_STMT: |
3e605b20 | 5185 | case PLACEHOLDER_EXPR: |
60813a46 JM |
5186 | case BREAK_STMT: |
5187 | case CONTINUE_STMT: | |
971e17ff | 5188 | case REQUIRES_EXPR: |
98e5a19a | 5189 | case STATIC_ASSERT: |
2d76680f PC |
5190 | return true; |
5191 | ||
a0ab7ccd JM |
5192 | case PARM_DECL: |
5193 | if (now) | |
5194 | { | |
5195 | if (flags & tf_error) | |
5196 | error ("%qE is not a constant expression", t); | |
5197 | return false; | |
5198 | } | |
5199 | return true; | |
5200 | ||
2d76680f PC |
5201 | case AGGR_INIT_EXPR: |
5202 | case CALL_EXPR: | |
5203 | /* -- an invocation of a function other than a constexpr function | |
5204 | or a constexpr constructor. */ | |
5205 | { | |
5206 | tree fun = get_function_named_in_call (t); | |
5207 | const int nargs = call_expr_nargs (t); | |
5208 | i = 0; | |
5209 | ||
60813a46 JM |
5210 | if (fun == NULL_TREE) |
5211 | { | |
44a845ca MS |
5212 | /* Reset to allow the function to continue past the end |
5213 | of the block below. Otherwise return early. */ | |
5214 | bool bail = true; | |
5215 | ||
35228ac7 JJ |
5216 | if (TREE_CODE (t) == CALL_EXPR |
5217 | && CALL_EXPR_FN (t) == NULL_TREE) | |
5218 | switch (CALL_EXPR_IFN (t)) | |
5219 | { | |
5220 | /* These should be ignored, they are optimized away from | |
5221 | constexpr functions. */ | |
5222 | case IFN_UBSAN_NULL: | |
5223 | case IFN_UBSAN_BOUNDS: | |
5224 | case IFN_UBSAN_VPTR: | |
81fea426 | 5225 | case IFN_FALLTHROUGH: |
35228ac7 | 5226 | return true; |
44a845ca MS |
5227 | |
5228 | case IFN_ADD_OVERFLOW: | |
5229 | case IFN_SUB_OVERFLOW: | |
5230 | case IFN_MUL_OVERFLOW: | |
e16f1cc7 | 5231 | case IFN_LAUNDER: |
44a845ca MS |
5232 | bail = false; |
5233 | ||
35228ac7 JJ |
5234 | default: |
5235 | break; | |
5236 | } | |
44a845ca MS |
5237 | |
5238 | if (bail) | |
5239 | { | |
5240 | /* fold_call_expr can't do anything with IFN calls. */ | |
5241 | if (flags & tf_error) | |
e40b6fc7 | 5242 | error_at (loc, "call to internal function %qE", t); |
44a845ca MS |
5243 | return false; |
5244 | } | |
60813a46 | 5245 | } |
44a845ca MS |
5246 | |
5247 | if (fun && is_overloaded_fn (fun)) | |
2d76680f PC |
5248 | { |
5249 | if (TREE_CODE (fun) == FUNCTION_DECL) | |
5250 | { | |
5251 | if (builtin_valid_in_constant_expr_p (fun)) | |
5252 | return true; | |
5253 | if (!DECL_DECLARED_CONSTEXPR_P (fun) | |
5254 | /* Allow any built-in function; if the expansion | |
5255 | isn't constant, we'll deal with that then. */ | |
5256 | && !is_builtin_fn (fun)) | |
5257 | { | |
5258 | if (flags & tf_error) | |
5259 | { | |
84fa214d | 5260 | error_at (loc, "call to non-%<constexpr%> function %qD", |
e40b6fc7 | 5261 | fun); |
2d76680f PC |
5262 | explain_invalid_constexpr_fn (fun); |
5263 | } | |
5264 | return false; | |
5265 | } | |
5266 | /* A call to a non-static member function takes the address | |
5267 | of the object as the first argument. But in a constant | |
5268 | expression the address will be folded away, so look | |
5269 | through it now. */ | |
5270 | if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fun) | |
5271 | && !DECL_CONSTRUCTOR_P (fun)) | |
5272 | { | |
5273 | tree x = get_nth_callarg (t, 0); | |
5274 | if (is_this_parameter (x)) | |
3e605b20 | 5275 | return true; |
a0ab7ccd JM |
5276 | /* Don't require an immediately constant value, as |
5277 | constexpr substitution might not use the value. */ | |
5278 | bool sub_now = false; | |
5279 | if (!potential_constant_expression_1 (x, rval, strict, | |
5280 | sub_now, flags)) | |
2d76680f PC |
5281 | return false; |
5282 | i = 1; | |
5283 | } | |
5284 | } | |
5285 | else | |
5286 | { | |
69eb4fde | 5287 | if (!RECUR (fun, true)) |
2d76680f PC |
5288 | return false; |
5289 | fun = get_first_fn (fun); | |
5290 | } | |
5291 | /* Skip initial arguments to base constructors. */ | |
5292 | if (DECL_BASE_CONSTRUCTOR_P (fun)) | |
5293 | i = num_artificial_parms_for (fun); | |
5294 | fun = DECL_ORIGIN (fun); | |
5295 | } | |
44a845ca | 5296 | else if (fun) |
2d76680f | 5297 | { |
69eb4fde | 5298 | if (RECUR (fun, rval)) |
2d76680f PC |
5299 | /* Might end up being a constant function pointer. */; |
5300 | else | |
5301 | return false; | |
5302 | } | |
5303 | for (; i < nargs; ++i) | |
5304 | { | |
5305 | tree x = get_nth_callarg (t, i); | |
c3c29ba5 JM |
5306 | /* In a template, reference arguments haven't been converted to |
5307 | REFERENCE_TYPE and we might not even know if the parameter | |
5308 | is a reference, so accept lvalue constants too. */ | |
5309 | bool rv = processing_template_decl ? any : rval; | |
a0ab7ccd JM |
5310 | /* Don't require an immediately constant value, as constexpr |
5311 | substitution might not use the value of the argument. */ | |
5312 | bool sub_now = false; | |
5313 | if (!potential_constant_expression_1 (x, rv, strict, | |
5314 | sub_now, flags)) | |
2d76680f PC |
5315 | return false; |
5316 | } | |
5317 | return true; | |
5318 | } | |
5319 | ||
5320 | case NON_LVALUE_EXPR: | |
5321 | /* -- an lvalue-to-rvalue conversion (4.1) unless it is applied to | |
5322 | -- an lvalue of integral type that refers to a non-volatile | |
5323 | const variable or static data member initialized with | |
5324 | constant expressions, or | |
5325 | ||
5326 | -- an lvalue of literal type that refers to non-volatile | |
5327 | object defined with constexpr, or that refers to a | |
5328 | sub-object of such an object; */ | |
69eb4fde | 5329 | return RECUR (TREE_OPERAND (t, 0), rval); |
2d76680f PC |
5330 | |
5331 | case VAR_DECL: | |
70f40fea | 5332 | if (DECL_HAS_VALUE_EXPR_P (t)) |
c1051bf7 JM |
5333 | { |
5334 | if (now && is_normal_capture_proxy (t)) | |
5335 | { | |
5336 | /* -- in a lambda-expression, a reference to this or to a | |
5337 | variable with automatic storage duration defined outside that | |
5338 | lambda-expression, where the reference would be an | |
5339 | odr-use. */ | |
5340 | if (flags & tf_error) | |
5341 | { | |
5342 | tree cap = DECL_CAPTURED_VARIABLE (t); | |
5343 | error ("lambda capture of %qE is not a constant expression", | |
5344 | cap); | |
5345 | if (!want_rval && decl_constant_var_p (cap)) | |
5346 | inform (input_location, "because it is used as a glvalue"); | |
5347 | } | |
5348 | return false; | |
5349 | } | |
5350 | return RECUR (DECL_VALUE_EXPR (t), rval); | |
5351 | } | |
69eb4fde | 5352 | if (want_rval |
98e5a19a | 5353 | && !var_in_maybe_constexpr_fn (t) |
7dc2b4a2 | 5354 | && !type_dependent_expression_p (t) |
4b691b13 | 5355 | && !decl_maybe_constant_var_p (t) |
69eb4fde JM |
5356 | && (strict |
5357 | || !CP_TYPE_CONST_NON_VOLATILE_P (TREE_TYPE (t)) | |
4b691b13 JM |
5358 | || (DECL_INITIAL (t) |
5359 | && !DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (t))) | |
7dc2b4a2 JM |
5360 | && COMPLETE_TYPE_P (TREE_TYPE (t)) |
5361 | && !is_really_empty_class (TREE_TYPE (t))) | |
2d76680f PC |
5362 | { |
5363 | if (flags & tf_error) | |
5364 | non_const_var_error (t); | |
5365 | return false; | |
5366 | } | |
5367 | return true; | |
5368 | ||
5369 | case NOP_EXPR: | |
5370 | case CONVERT_EXPR: | |
5371 | case VIEW_CONVERT_EXPR: | |
5372 | /* -- a reinterpret_cast. FIXME not implemented, and this rule | |
5373 | may change to something more specific to type-punning (DR 1312). */ | |
5374 | { | |
5375 | tree from = TREE_OPERAND (t, 0); | |
5376 | if (POINTER_TYPE_P (TREE_TYPE (t)) | |
5377 | && TREE_CODE (from) == INTEGER_CST | |
5378 | && !integer_zerop (from)) | |
5379 | { | |
5380 | if (flags & tf_error) | |
e40b6fc7 | 5381 | error_at (loc, "reinterpret_cast from integer to pointer"); |
2d76680f PC |
5382 | return false; |
5383 | } | |
69eb4fde | 5384 | return (RECUR (from, TREE_CODE (t) != VIEW_CONVERT_EXPR)); |
2d76680f PC |
5385 | } |
5386 | ||
be845b04 JJ |
5387 | case ADDRESSOF_EXPR: |
5388 | /* This is like ADDR_EXPR, except it won't form pointer-to-member. */ | |
5389 | t = TREE_OPERAND (t, 0); | |
5390 | goto handle_addr_expr; | |
5391 | ||
2d76680f PC |
5392 | case ADDR_EXPR: |
5393 | /* -- a unary operator & that is applied to an lvalue that | |
5394 | designates an object with thread or automatic storage | |
5395 | duration; */ | |
5396 | t = TREE_OPERAND (t, 0); | |
5397 | ||
5398 | if (TREE_CODE (t) == OFFSET_REF && PTRMEM_OK_P (t)) | |
5399 | /* A pointer-to-member constant. */ | |
5400 | return true; | |
5401 | ||
be845b04 | 5402 | handle_addr_expr: |
2d76680f PC |
5403 | #if 0 |
5404 | /* FIXME adjust when issue 1197 is fully resolved. For now don't do | |
5405 | any checking here, as we might dereference the pointer later. If | |
5406 | we remove this code, also remove check_automatic_or_tls. */ | |
5407 | i = check_automatic_or_tls (t); | |
5408 | if (i == ck_ok) | |
5409 | return true; | |
5410 | if (i == ck_bad) | |
5411 | { | |
5412 | if (flags & tf_error) | |
5413 | error ("address-of an object %qE with thread local or " | |
5414 | "automatic storage is not a constant expression", t); | |
5415 | return false; | |
5416 | } | |
5417 | #endif | |
69eb4fde | 5418 | return RECUR (t, any); |
2d76680f | 5419 | |
dc8d2d00 JM |
5420 | case REALPART_EXPR: |
5421 | case IMAGPART_EXPR: | |
2d76680f PC |
5422 | case COMPONENT_REF: |
5423 | case BIT_FIELD_REF: | |
5424 | case ARROW_EXPR: | |
5425 | case OFFSET_REF: | |
5426 | /* -- a class member access unless its postfix-expression is | |
5427 | of literal type or of pointer to literal type. */ | |
5428 | /* This test would be redundant, as it follows from the | |
5429 | postfix-expression being a potential constant expression. */ | |
19dedccf JM |
5430 | if (type_unknown_p (t)) |
5431 | return true; | |
69eb4fde | 5432 | return RECUR (TREE_OPERAND (t, 0), want_rval); |
2d76680f PC |
5433 | |
5434 | case EXPR_PACK_EXPANSION: | |
69eb4fde | 5435 | return RECUR (PACK_EXPANSION_PATTERN (t), want_rval); |
2d76680f PC |
5436 | |
5437 | case INDIRECT_REF: | |
5438 | { | |
5439 | tree x = TREE_OPERAND (t, 0); | |
5440 | STRIP_NOPS (x); | |
948d0d91 | 5441 | if (is_this_parameter (x) && !is_capture_proxy (x)) |
2d76680f | 5442 | { |
5d4e573b | 5443 | if (!var_in_maybe_constexpr_fn (x)) |
2d76680f PC |
5444 | { |
5445 | if (flags & tf_error) | |
e40b6fc7 | 5446 | error_at (loc, "use of %<this%> in a constant expression"); |
2d76680f PC |
5447 | return false; |
5448 | } | |
2d76680f PC |
5449 | return true; |
5450 | } | |
69eb4fde | 5451 | return RECUR (x, rval); |
2d76680f PC |
5452 | } |
5453 | ||
60813a46 JM |
5454 | case STATEMENT_LIST: |
5455 | { | |
5456 | tree_stmt_iterator i; | |
5457 | for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i)) | |
5458 | { | |
69eb4fde | 5459 | if (!RECUR (tsi_stmt (i), any)) |
60813a46 JM |
5460 | return false; |
5461 | } | |
5462 | return true; | |
5463 | } | |
5464 | break; | |
5465 | ||
5466 | case MODIFY_EXPR: | |
5467 | if (cxx_dialect < cxx14) | |
5468 | goto fail; | |
69eb4fde | 5469 | if (!RECUR (TREE_OPERAND (t, 0), any)) |
60813a46 | 5470 | return false; |
69eb4fde | 5471 | if (!RECUR (TREE_OPERAND (t, 1), rval)) |
60813a46 JM |
5472 | return false; |
5473 | return true; | |
5474 | ||
5475 | case MODOP_EXPR: | |
5476 | if (cxx_dialect < cxx14) | |
5477 | goto fail; | |
69eb4fde | 5478 | if (!RECUR (TREE_OPERAND (t, 0), rval)) |
60813a46 | 5479 | return false; |
69eb4fde | 5480 | if (!RECUR (TREE_OPERAND (t, 2), rval)) |
60813a46 JM |
5481 | return false; |
5482 | return true; | |
5483 | ||
60813a46 | 5484 | case DO_STMT: |
69eb4fde | 5485 | if (!RECUR (DO_COND (t), rval)) |
60813a46 | 5486 | return false; |
69eb4fde | 5487 | if (!RECUR (DO_BODY (t), any)) |
60813a46 JM |
5488 | return false; |
5489 | return true; | |
5490 | ||
5491 | case FOR_STMT: | |
69eb4fde | 5492 | if (!RECUR (FOR_INIT_STMT (t), any)) |
60813a46 | 5493 | return false; |
69eb4fde | 5494 | if (!RECUR (FOR_COND (t), rval)) |
60813a46 | 5495 | return false; |
69eb4fde | 5496 | if (!RECUR (FOR_EXPR (t), any)) |
60813a46 | 5497 | return false; |
69eb4fde | 5498 | if (!RECUR (FOR_BODY (t), any)) |
60813a46 JM |
5499 | return false; |
5500 | return true; | |
5501 | ||
98e5a19a JM |
5502 | case RANGE_FOR_STMT: |
5503 | if (!RECUR (RANGE_FOR_EXPR (t), any)) | |
5504 | return false; | |
5505 | if (!RECUR (RANGE_FOR_BODY (t), any)) | |
5506 | return false; | |
5507 | return true; | |
5508 | ||
60813a46 | 5509 | case WHILE_STMT: |
69eb4fde | 5510 | if (!RECUR (WHILE_COND (t), rval)) |
60813a46 | 5511 | return false; |
69eb4fde | 5512 | if (!RECUR (WHILE_BODY (t), any)) |
60813a46 JM |
5513 | return false; |
5514 | return true; | |
5515 | ||
5516 | case SWITCH_STMT: | |
69eb4fde | 5517 | if (!RECUR (SWITCH_STMT_COND (t), rval)) |
60813a46 | 5518 | return false; |
ce965730 MT |
5519 | /* FIXME we don't check SWITCH_STMT_BODY currently, because even |
5520 | unreachable labels would be checked. */ | |
60813a46 JM |
5521 | return true; |
5522 | ||
58611fb6 | 5523 | case STMT_EXPR: |
69eb4fde | 5524 | return RECUR (STMT_EXPR_STMT (t), rval); |
58611fb6 | 5525 | |
2d76680f PC |
5526 | case LAMBDA_EXPR: |
5527 | case DYNAMIC_CAST_EXPR: | |
5528 | case PSEUDO_DTOR_EXPR: | |
2d76680f PC |
5529 | case NEW_EXPR: |
5530 | case VEC_NEW_EXPR: | |
5531 | case DELETE_EXPR: | |
5532 | case VEC_DELETE_EXPR: | |
5533 | case THROW_EXPR: | |
e40b6fc7 JJ |
5534 | case OMP_PARALLEL: |
5535 | case OMP_TASK: | |
5536 | case OMP_FOR: | |
5537 | case OMP_DISTRIBUTE: | |
5538 | case OMP_TASKLOOP: | |
5539 | case OMP_TEAMS: | |
5540 | case OMP_TARGET_DATA: | |
5541 | case OMP_TARGET: | |
5542 | case OMP_SECTIONS: | |
5543 | case OMP_ORDERED: | |
5544 | case OMP_CRITICAL: | |
5545 | case OMP_SINGLE: | |
5546 | case OMP_SECTION: | |
5547 | case OMP_MASTER: | |
5548 | case OMP_TASKGROUP: | |
5549 | case OMP_TARGET_UPDATE: | |
5550 | case OMP_TARGET_ENTER_DATA: | |
5551 | case OMP_TARGET_EXIT_DATA: | |
2d76680f PC |
5552 | case OMP_ATOMIC: |
5553 | case OMP_ATOMIC_READ: | |
5554 | case OMP_ATOMIC_CAPTURE_OLD: | |
5555 | case OMP_ATOMIC_CAPTURE_NEW: | |
e40b6fc7 JJ |
5556 | case OACC_PARALLEL: |
5557 | case OACC_KERNELS: | |
5558 | case OACC_DATA: | |
5559 | case OACC_HOST_DATA: | |
5560 | case OACC_LOOP: | |
5561 | case OACC_CACHE: | |
5562 | case OACC_DECLARE: | |
5563 | case OACC_ENTER_DATA: | |
5564 | case OACC_EXIT_DATA: | |
5565 | case OACC_UPDATE: | |
2d76680f PC |
5566 | /* GCC internal stuff. */ |
5567 | case VA_ARG_EXPR: | |
5568 | case OBJ_TYPE_REF: | |
2d76680f | 5569 | case TRANSACTION_EXPR: |
60813a46 | 5570 | case ASM_EXPR: |
81b6a6c5 | 5571 | case AT_ENCODE_EXPR: |
60813a46 | 5572 | fail: |
2d76680f | 5573 | if (flags & tf_error) |
e40b6fc7 | 5574 | error_at (loc, "expression %qE is not a constant expression", t); |
2d76680f PC |
5575 | return false; |
5576 | ||
5577 | case TYPEID_EXPR: | |
5578 | /* -- a typeid expression whose operand is of polymorphic | |
5579 | class type; */ | |
5580 | { | |
5581 | tree e = TREE_OPERAND (t, 0); | |
5582 | if (!TYPE_P (e) && !type_dependent_expression_p (e) | |
5583 | && TYPE_POLYMORPHIC_P (TREE_TYPE (e))) | |
5584 | { | |
5585 | if (flags & tf_error) | |
e40b6fc7 JJ |
5586 | error_at (loc, "typeid-expression is not a constant expression " |
5587 | "because %qE is of polymorphic type", e); | |
2d76680f PC |
5588 | return false; |
5589 | } | |
5590 | return true; | |
5591 | } | |
5592 | ||
1af4ebf5 | 5593 | case POINTER_DIFF_EXPR: |
2d76680f | 5594 | case MINUS_EXPR: |
2d76680f PC |
5595 | want_rval = true; |
5596 | goto binary; | |
5597 | ||
5598 | case LT_EXPR: | |
5599 | case LE_EXPR: | |
5600 | case GT_EXPR: | |
5601 | case GE_EXPR: | |
5602 | case EQ_EXPR: | |
5603 | case NE_EXPR: | |
2d76680f PC |
5604 | want_rval = true; |
5605 | goto binary; | |
5606 | ||
60813a46 JM |
5607 | case PREINCREMENT_EXPR: |
5608 | case POSTINCREMENT_EXPR: | |
5609 | case PREDECREMENT_EXPR: | |
5610 | case POSTDECREMENT_EXPR: | |
5611 | if (cxx_dialect < cxx14) | |
5612 | goto fail; | |
5613 | goto unary; | |
5614 | ||
2d76680f PC |
5615 | case BIT_NOT_EXPR: |
5616 | /* A destructor. */ | |
5617 | if (TYPE_P (TREE_OPERAND (t, 0))) | |
5618 | return true; | |
191816a3 | 5619 | /* fall through. */ |
2d76680f | 5620 | |
2d76680f PC |
5621 | case CONJ_EXPR: |
5622 | case SAVE_EXPR: | |
5623 | case FIX_TRUNC_EXPR: | |
5624 | case FLOAT_EXPR: | |
5625 | case NEGATE_EXPR: | |
5626 | case ABS_EXPR: | |
5627 | case TRUTH_NOT_EXPR: | |
5628 | case FIXED_CONVERT_EXPR: | |
5629 | case UNARY_PLUS_EXPR: | |
4856a1f0 PC |
5630 | case UNARY_LEFT_FOLD_EXPR: |
5631 | case UNARY_RIGHT_FOLD_EXPR: | |
60813a46 | 5632 | unary: |
69eb4fde | 5633 | return RECUR (TREE_OPERAND (t, 0), rval); |
2d76680f PC |
5634 | |
5635 | case CAST_EXPR: | |
5636 | case CONST_CAST_EXPR: | |
5637 | case STATIC_CAST_EXPR: | |
5638 | case REINTERPRET_CAST_EXPR: | |
5639 | case IMPLICIT_CONV_EXPR: | |
5640 | if (cxx_dialect < cxx11 | |
5641 | && !dependent_type_p (TREE_TYPE (t)) | |
5642 | && !INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))) | |
5643 | /* In C++98, a conversion to non-integral type can't be part of a | |
5644 | constant expression. */ | |
5645 | { | |
5646 | if (flags & tf_error) | |
e40b6fc7 JJ |
5647 | error_at (loc, |
5648 | "cast to non-integral type %qT in a constant expression", | |
5649 | TREE_TYPE (t)); | |
2d76680f PC |
5650 | return false; |
5651 | } | |
5652 | ||
69eb4fde JM |
5653 | return (RECUR (TREE_OPERAND (t, 0), |
5654 | TREE_CODE (TREE_TYPE (t)) != REFERENCE_TYPE)); | |
2d76680f | 5655 | |
60813a46 | 5656 | case BIND_EXPR: |
69eb4fde | 5657 | return RECUR (BIND_EXPR_BODY (t), want_rval); |
60813a46 | 5658 | |
60813a46 JM |
5659 | case CLEANUP_POINT_EXPR: |
5660 | case MUST_NOT_THROW_EXPR: | |
5661 | case TRY_CATCH_EXPR: | |
769430b2 | 5662 | case TRY_BLOCK: |
60813a46 JM |
5663 | case EH_SPEC_BLOCK: |
5664 | case EXPR_STMT: | |
2d76680f PC |
5665 | case PAREN_EXPR: |
5666 | case NON_DEPENDENT_EXPR: | |
5667 | /* For convenience. */ | |
5668 | case RETURN_EXPR: | |
f937929e JM |
5669 | case LOOP_EXPR: |
5670 | case EXIT_EXPR: | |
69eb4fde | 5671 | return RECUR (TREE_OPERAND (t, 0), want_rval); |
2d76680f | 5672 | |
98e5a19a JM |
5673 | case DECL_EXPR: |
5674 | tmp = DECL_EXPR_DECL (t); | |
5675 | if (VAR_P (tmp) && !DECL_ARTIFICIAL (tmp)) | |
5676 | { | |
5677 | if (TREE_STATIC (tmp)) | |
5678 | { | |
5679 | if (flags & tf_error) | |
5680 | error_at (DECL_SOURCE_LOCATION (tmp), "%qD declared " | |
4b691b13 | 5681 | "%<static%> in %<constexpr%> context", tmp); |
98e5a19a JM |
5682 | return false; |
5683 | } | |
5684 | else if (CP_DECL_THREAD_LOCAL_P (tmp)) | |
5685 | { | |
5686 | if (flags & tf_error) | |
5687 | error_at (DECL_SOURCE_LOCATION (tmp), "%qD declared " | |
4b691b13 | 5688 | "%<thread_local%> in %<constexpr%> context", tmp); |
98e5a19a JM |
5689 | return false; |
5690 | } | |
5691 | else if (!DECL_NONTRIVIALLY_INITIALIZED_P (tmp)) | |
5692 | { | |
5693 | if (flags & tf_error) | |
5694 | error_at (DECL_SOURCE_LOCATION (tmp), "uninitialized " | |
4b691b13 | 5695 | "variable %qD in %<constexpr%> context", tmp); |
98e5a19a JM |
5696 | return false; |
5697 | } | |
5698 | } | |
5699 | return RECUR (tmp, want_rval); | |
5700 | ||
769430b2 JM |
5701 | case TRY_FINALLY_EXPR: |
5702 | return (RECUR (TREE_OPERAND (t, 0), want_rval) | |
5703 | && RECUR (TREE_OPERAND (t, 1), any)); | |
5704 | ||
2d76680f | 5705 | case SCOPE_REF: |
69eb4fde | 5706 | return RECUR (TREE_OPERAND (t, 1), want_rval); |
2d76680f PC |
5707 | |
5708 | case TARGET_EXPR: | |
5709 | if (!literal_type_p (TREE_TYPE (t))) | |
5710 | { | |
5711 | if (flags & tf_error) | |
5712 | { | |
e40b6fc7 JJ |
5713 | error_at (loc, "temporary of non-literal type %qT in a " |
5714 | "constant expression", TREE_TYPE (t)); | |
2d76680f PC |
5715 | explain_non_literal_class (TREE_TYPE (t)); |
5716 | } | |
5717 | return false; | |
5718 | } | |
191816a3 | 5719 | /* FALLTHRU */ |
2d76680f | 5720 | case INIT_EXPR: |
69eb4fde | 5721 | return RECUR (TREE_OPERAND (t, 1), rval); |
2d76680f PC |
5722 | |
5723 | case CONSTRUCTOR: | |
5724 | { | |
5725 | vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (t); | |
5726 | constructor_elt *ce; | |
5727 | for (i = 0; vec_safe_iterate (v, i, &ce); ++i) | |
69eb4fde | 5728 | if (!RECUR (ce->value, want_rval)) |
2d76680f PC |
5729 | return false; |
5730 | return true; | |
5731 | } | |
5732 | ||
5733 | case TREE_LIST: | |
5734 | { | |
5735 | gcc_assert (TREE_PURPOSE (t) == NULL_TREE | |
5736 | || DECL_P (TREE_PURPOSE (t))); | |
69eb4fde | 5737 | if (!RECUR (TREE_VALUE (t), want_rval)) |
2d76680f PC |
5738 | return false; |
5739 | if (TREE_CHAIN (t) == NULL_TREE) | |
5740 | return true; | |
69eb4fde | 5741 | return RECUR (TREE_CHAIN (t), want_rval); |
2d76680f PC |
5742 | } |
5743 | ||
5744 | case TRUNC_DIV_EXPR: | |
5745 | case CEIL_DIV_EXPR: | |
5746 | case FLOOR_DIV_EXPR: | |
5747 | case ROUND_DIV_EXPR: | |
5748 | case TRUNC_MOD_EXPR: | |
5749 | case CEIL_MOD_EXPR: | |
5750 | case ROUND_MOD_EXPR: | |
5751 | { | |
5752 | tree denom = TREE_OPERAND (t, 1); | |
69eb4fde | 5753 | if (!RECUR (denom, rval)) |
2d76680f PC |
5754 | return false; |
5755 | /* We can't call cxx_eval_outermost_constant_expr on an expression | |
234bef96 | 5756 | that hasn't been through instantiate_non_dependent_expr yet. */ |
2d76680f PC |
5757 | if (!processing_template_decl) |
5758 | denom = cxx_eval_outermost_constant_expr (denom, true); | |
5759 | if (integer_zerop (denom)) | |
5760 | { | |
5761 | if (flags & tf_error) | |
64d6d399 | 5762 | error ("division by zero is not a constant expression"); |
2d76680f PC |
5763 | return false; |
5764 | } | |
5765 | else | |
5766 | { | |
5767 | want_rval = true; | |
69eb4fde | 5768 | return RECUR (TREE_OPERAND (t, 0), want_rval); |
2d76680f PC |
5769 | } |
5770 | } | |
5771 | ||
5772 | case COMPOUND_EXPR: | |
5773 | { | |
5774 | /* check_return_expr sometimes wraps a TARGET_EXPR in a | |
5775 | COMPOUND_EXPR; don't get confused. Also handle EMPTY_CLASS_EXPR | |
5776 | introduced by build_call_a. */ | |
5777 | tree op0 = TREE_OPERAND (t, 0); | |
5778 | tree op1 = TREE_OPERAND (t, 1); | |
5779 | STRIP_NOPS (op1); | |
5780 | if ((TREE_CODE (op0) == TARGET_EXPR && op1 == TARGET_EXPR_SLOT (op0)) | |
5781 | || TREE_CODE (op1) == EMPTY_CLASS_EXPR) | |
69eb4fde | 5782 | return RECUR (op0, want_rval); |
2d76680f PC |
5783 | else |
5784 | goto binary; | |
5785 | } | |
5786 | ||
5787 | /* If the first operand is the non-short-circuit constant, look at | |
5788 | the second operand; otherwise we only care about the first one for | |
5789 | potentiality. */ | |
5790 | case TRUTH_AND_EXPR: | |
5791 | case TRUTH_ANDIF_EXPR: | |
5792 | tmp = boolean_true_node; | |
5793 | goto truth; | |
5794 | case TRUTH_OR_EXPR: | |
5795 | case TRUTH_ORIF_EXPR: | |
5796 | tmp = boolean_false_node; | |
5797 | truth: | |
5798 | { | |
5799 | tree op = TREE_OPERAND (t, 0); | |
69eb4fde | 5800 | if (!RECUR (op, rval)) |
2d76680f PC |
5801 | return false; |
5802 | if (!processing_template_decl) | |
5803 | op = cxx_eval_outermost_constant_expr (op, true); | |
5804 | if (tree_int_cst_equal (op, tmp)) | |
69eb4fde | 5805 | return RECUR (TREE_OPERAND (t, 1), rval); |
2d76680f PC |
5806 | else |
5807 | return true; | |
5808 | } | |
5809 | ||
5810 | case PLUS_EXPR: | |
5811 | case MULT_EXPR: | |
5812 | case POINTER_PLUS_EXPR: | |
5813 | case RDIV_EXPR: | |
5814 | case EXACT_DIV_EXPR: | |
5815 | case MIN_EXPR: | |
5816 | case MAX_EXPR: | |
5817 | case LSHIFT_EXPR: | |
5818 | case RSHIFT_EXPR: | |
5819 | case LROTATE_EXPR: | |
5820 | case RROTATE_EXPR: | |
5821 | case BIT_IOR_EXPR: | |
5822 | case BIT_XOR_EXPR: | |
5823 | case BIT_AND_EXPR: | |
5824 | case TRUTH_XOR_EXPR: | |
5825 | case UNORDERED_EXPR: | |
5826 | case ORDERED_EXPR: | |
5827 | case UNLT_EXPR: | |
5828 | case UNLE_EXPR: | |
5829 | case UNGT_EXPR: | |
5830 | case UNGE_EXPR: | |
5831 | case UNEQ_EXPR: | |
5832 | case LTGT_EXPR: | |
5833 | case RANGE_EXPR: | |
5834 | case COMPLEX_EXPR: | |
5835 | want_rval = true; | |
5836 | /* Fall through. */ | |
5837 | case ARRAY_REF: | |
5838 | case ARRAY_RANGE_REF: | |
5839 | case MEMBER_REF: | |
5840 | case DOTSTAR_EXPR: | |
41b38772 | 5841 | case MEM_REF: |
4856a1f0 PC |
5842 | case BINARY_LEFT_FOLD_EXPR: |
5843 | case BINARY_RIGHT_FOLD_EXPR: | |
2d76680f PC |
5844 | binary: |
5845 | for (i = 0; i < 2; ++i) | |
69eb4fde | 5846 | if (!RECUR (TREE_OPERAND (t, i), want_rval)) |
2d76680f PC |
5847 | return false; |
5848 | return true; | |
5849 | ||
2d76680f PC |
5850 | case FMA_EXPR: |
5851 | case VEC_PERM_EXPR: | |
5852 | for (i = 0; i < 3; ++i) | |
69eb4fde | 5853 | if (!RECUR (TREE_OPERAND (t, i), true)) |
2d76680f PC |
5854 | return false; |
5855 | return true; | |
5856 | ||
5857 | case COND_EXPR: | |
d5bcd6d4 JM |
5858 | if (COND_EXPR_IS_VEC_DELETE (t)) |
5859 | { | |
5860 | if (flags & tf_error) | |
e40b6fc7 | 5861 | error_at (loc, "%<delete[]%> is not a constant expression"); |
d5bcd6d4 JM |
5862 | return false; |
5863 | } | |
5864 | /* Fall through. */ | |
5865 | case IF_STMT: | |
2d76680f PC |
5866 | case VEC_COND_EXPR: |
5867 | /* If the condition is a known constant, we know which of the legs we | |
5868 | care about; otherwise we only require that the condition and | |
5869 | either of the legs be potentially constant. */ | |
5870 | tmp = TREE_OPERAND (t, 0); | |
69eb4fde | 5871 | if (!RECUR (tmp, rval)) |
2d76680f PC |
5872 | return false; |
5873 | if (!processing_template_decl) | |
5874 | tmp = cxx_eval_outermost_constant_expr (tmp, true); | |
5875 | if (integer_zerop (tmp)) | |
69eb4fde | 5876 | return RECUR (TREE_OPERAND (t, 2), want_rval); |
2d76680f | 5877 | else if (TREE_CODE (tmp) == INTEGER_CST) |
69eb4fde | 5878 | return RECUR (TREE_OPERAND (t, 1), want_rval); |
2d76680f PC |
5879 | for (i = 1; i < 3; ++i) |
5880 | if (potential_constant_expression_1 (TREE_OPERAND (t, i), | |
a0ab7ccd | 5881 | want_rval, strict, now, tf_none)) |
2d76680f PC |
5882 | return true; |
5883 | if (flags & tf_error) | |
e40b6fc7 | 5884 | error_at (loc, "expression %qE is not a constant expression", t); |
2d76680f PC |
5885 | return false; |
5886 | ||
5887 | case VEC_INIT_EXPR: | |
5888 | if (VEC_INIT_EXPR_IS_CONSTEXPR (t)) | |
5889 | return true; | |
5890 | if (flags & tf_error) | |
5891 | { | |
e40b6fc7 | 5892 | error_at (loc, "non-constant array initialization"); |
2d76680f PC |
5893 | diagnose_non_constexpr_vec_init (t); |
5894 | } | |
5895 | return false; | |
5896 | ||
133bc698 JM |
5897 | case TYPE_DECL: |
5898 | case TAG_DEFN: | |
5899 | /* We can see these in statement-expressions. */ | |
5900 | return true; | |
5901 | ||
baf9ebc8 | 5902 | case CLEANUP_STMT: |
cda0a029 | 5903 | case EMPTY_CLASS_EXPR: |
7fef86d3 | 5904 | case PREDICT_EXPR: |
cda0a029 JM |
5905 | return false; |
5906 | ||
f937929e JM |
5907 | case GOTO_EXPR: |
5908 | { | |
5909 | tree *target = &TREE_OPERAND (t, 0); | |
ab3af181 JJ |
5910 | /* Gotos representing break and continue are OK. */ |
5911 | if (breaks (target) || continues (target)) | |
5912 | return true; | |
5913 | if (flags & tf_error) | |
e40b6fc7 | 5914 | error_at (loc, "%<goto%> is not a constant expression"); |
ab3af181 | 5915 | return false; |
f937929e JM |
5916 | } |
5917 | ||
98e09245 JJ |
5918 | case ANNOTATE_EXPR: |
5919 | gcc_assert (tree_to_uhwi (TREE_OPERAND (t, 1)) == annot_expr_ivdep_kind); | |
5920 | return RECUR (TREE_OPERAND (t, 0), rval); | |
5921 | ||
2d76680f PC |
5922 | default: |
5923 | if (objc_is_property_ref (t)) | |
5924 | return false; | |
5925 | ||
5926 | sorry ("unexpected AST of kind %s", get_tree_code_name (TREE_CODE (t))); | |
ab3af181 | 5927 | gcc_unreachable (); |
2d76680f PC |
5928 | return false; |
5929 | } | |
69eb4fde | 5930 | #undef RECUR |
2d76680f PC |
5931 | } |
5932 | ||
5933 | /* The main entry point to the above. */ | |
5934 | ||
5935 | bool | |
5936 | potential_constant_expression (tree t) | |
5937 | { | |
a0ab7ccd | 5938 | return potential_constant_expression_1 (t, false, true, false, tf_none); |
2d76680f PC |
5939 | } |
5940 | ||
5941 | /* As above, but require a constant rvalue. */ | |
5942 | ||
5943 | bool | |
5944 | potential_rvalue_constant_expression (tree t) | |
5945 | { | |
a0ab7ccd | 5946 | return potential_constant_expression_1 (t, true, true, false, tf_none); |
2d76680f PC |
5947 | } |
5948 | ||
5949 | /* Like above, but complain about non-constant expressions. */ | |
5950 | ||
5951 | bool | |
5952 | require_potential_constant_expression (tree t) | |
5953 | { | |
a0ab7ccd | 5954 | return potential_constant_expression_1 (t, false, true, false, tf_warning_or_error); |
2d76680f PC |
5955 | } |
5956 | ||
5957 | /* Cross product of the above. */ | |
5958 | ||
5959 | bool | |
5960 | require_potential_rvalue_constant_expression (tree t) | |
5961 | { | |
a0ab7ccd JM |
5962 | return potential_constant_expression_1 (t, true, true, false, tf_warning_or_error); |
5963 | } | |
5964 | ||
5965 | /* Like potential_constant_expression, but don't consider possible constexpr | |
5966 | substitution of the current function. That is, PARM_DECL qualifies under | |
5967 | potential_constant_expression, but not here. | |
5968 | ||
5969 | This is basically what you can check when any actual constant values might | |
5970 | be value-dependent. */ | |
5971 | ||
5972 | bool | |
5973 | is_constant_expression (tree t) | |
5974 | { | |
5975 | return potential_constant_expression_1 (t, false, true, true, tf_none); | |
5976 | } | |
5977 | ||
5978 | /* Like above, but complain about non-constant expressions. */ | |
5979 | ||
5980 | bool | |
5981 | require_constant_expression (tree t) | |
5982 | { | |
5983 | return potential_constant_expression_1 (t, false, true, true, | |
5984 | tf_warning_or_error); | |
5985 | } | |
5986 | ||
5987 | /* Like is_constant_expression, but allow const variables that are not allowed | |
5988 | under constexpr rules. */ | |
5989 | ||
5990 | bool | |
5991 | is_static_init_expression (tree t) | |
5992 | { | |
5993 | return potential_constant_expression_1 (t, false, false, true, tf_none); | |
2d76680f PC |
5994 | } |
5995 | ||
eb07f187 JM |
5996 | /* Returns true if T is a potential constant expression that is not |
5997 | instantiation-dependent, and therefore a candidate for constant folding even | |
5998 | in a template. */ | |
5999 | ||
6000 | bool | |
a0ab7ccd | 6001 | is_nondependent_constant_expression (tree t) |
eb07f187 JM |
6002 | { |
6003 | return (!type_unknown_p (t) | |
6004 | && !BRACE_ENCLOSED_INITIALIZER_P (t) | |
a0ab7ccd | 6005 | && is_constant_expression (t) |
eb07f187 JM |
6006 | && !instantiation_dependent_expression_p (t)); |
6007 | } | |
6008 | ||
6009 | /* Returns true if T is a potential static initializer expression that is not | |
6010 | instantiation-dependent. */ | |
6011 | ||
6012 | bool | |
a0ab7ccd | 6013 | is_nondependent_static_init_expression (tree t) |
eb07f187 JM |
6014 | { |
6015 | return (!type_unknown_p (t) | |
6016 | && !BRACE_ENCLOSED_INITIALIZER_P (t) | |
a0ab7ccd | 6017 | && is_static_init_expression (t) |
eb07f187 JM |
6018 | && !instantiation_dependent_expression_p (t)); |
6019 | } | |
6020 | ||
97f3003f JM |
6021 | /* Finalize constexpr processing after parsing. */ |
6022 | ||
6023 | void | |
6024 | fini_constexpr (void) | |
6025 | { | |
6026 | /* The contexpr call and fundef copies tables are no longer needed. */ | |
6027 | constexpr_call_table = NULL; | |
6028 | fundef_copies_table = NULL; | |
6029 | } | |
6030 | ||
2d76680f | 6031 | #include "gt-cp-constexpr.h" |