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Commit | Line | Data |
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13f649f6 JM |
1 | /* Perform -*- C++ -*- constant expression evaluation, including calls to |
2 | constexpr functions. These routines are used both during actual parsing | |
2d76680f PC |
3 | and during the instantiation of template functions. |
4 | ||
a5544970 | 5 | Copyright (C) 1998-2019 Free Software Foundation, Inc. |
2d76680f PC |
6 | |
7 | This file is part of GCC. | |
8 | ||
9 | GCC is free software; you can redistribute it and/or modify it | |
10 | under the terms of the GNU General Public License as published by | |
11 | the Free Software Foundation; either version 3, or (at your option) | |
12 | any later version. | |
13 | ||
14 | GCC is distributed in the hope that it will be useful, but | |
15 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
17 | General Public License for more details. | |
18 | ||
19 | You should have received a copy of the GNU General Public License | |
20 | along with GCC; see the file COPYING3. If not see | |
21 | <http://www.gnu.org/licenses/>. */ | |
22 | ||
23 | #include "config.h" | |
24 | #include "system.h" | |
25 | #include "coretypes.h" | |
2d76680f | 26 | #include "cp-tree.h" |
2adfab87 | 27 | #include "varasm.h" |
2d76680f PC |
28 | #include "c-family/c-objc.h" |
29 | #include "tree-iterator.h" | |
30 | #include "gimplify.h" | |
31 | #include "builtins.h" | |
60813a46 | 32 | #include "tree-inline.h" |
0b274c17 | 33 | #include "ubsan.h" |
44a845ca | 34 | #include "gimple-fold.h" |
8108ea30 | 35 | #include "timevar.h" |
d8fcab68 | 36 | #include "fold-const-call.h" |
8e007055 | 37 | #include "stor-layout.h" |
2d76680f PC |
38 | |
39 | static bool verify_constant (tree, bool, bool *, bool *); | |
40 | #define VERIFY_CONSTANT(X) \ | |
41 | do { \ | |
2b3ab879 | 42 | if (verify_constant ((X), ctx->quiet, non_constant_p, overflow_p)) \ |
2d76680f PC |
43 | return t; \ |
44 | } while (0) | |
45 | ||
582d2481 JJ |
46 | static HOST_WIDE_INT find_array_ctor_elt (tree ary, tree dindex, |
47 | bool insert = false); | |
48 | ||
2d76680f PC |
49 | /* Returns true iff FUN is an instantiation of a constexpr function |
50 | template or a defaulted constexpr function. */ | |
51 | ||
52 | bool | |
53 | is_instantiation_of_constexpr (tree fun) | |
54 | { | |
55 | return ((DECL_TEMPLOID_INSTANTIATION (fun) | |
56 | && DECL_DECLARED_CONSTEXPR_P (DECL_TI_TEMPLATE (fun))) | |
57 | || (DECL_DEFAULTED_FN (fun) | |
58 | && DECL_DECLARED_CONSTEXPR_P (fun))); | |
59 | } | |
60 | ||
61 | /* Return true if T is a literal type. */ | |
62 | ||
63 | bool | |
64 | literal_type_p (tree t) | |
65 | { | |
66 | if (SCALAR_TYPE_P (t) | |
b55b02ea | 67 | || VECTOR_TYPE_P (t) |
9f613f06 | 68 | || TYPE_REF_P (t) |
e42c407c | 69 | || (VOID_TYPE_P (t) && cxx_dialect >= cxx14)) |
2d76680f PC |
70 | return true; |
71 | if (CLASS_TYPE_P (t)) | |
72 | { | |
73 | t = complete_type (t); | |
74 | gcc_assert (COMPLETE_TYPE_P (t) || errorcount); | |
75 | return CLASSTYPE_LITERAL_P (t); | |
76 | } | |
77 | if (TREE_CODE (t) == ARRAY_TYPE) | |
78 | return literal_type_p (strip_array_types (t)); | |
79 | return false; | |
80 | } | |
81 | ||
82 | /* If DECL is a variable declared `constexpr', require its type | |
9638f320 PC |
83 | be literal. Return error_mark_node if we give an error, the |
84 | DECL otherwise. */ | |
2d76680f PC |
85 | |
86 | tree | |
87 | ensure_literal_type_for_constexpr_object (tree decl) | |
88 | { | |
89 | tree type = TREE_TYPE (decl); | |
90 | if (VAR_P (decl) | |
91 | && (DECL_DECLARED_CONSTEXPR_P (decl) | |
92 | || var_in_constexpr_fn (decl)) | |
93 | && !processing_template_decl) | |
94 | { | |
95 | tree stype = strip_array_types (type); | |
96 | if (CLASS_TYPE_P (stype) && !COMPLETE_TYPE_P (complete_type (stype))) | |
97 | /* Don't complain here, we'll complain about incompleteness | |
98 | when we try to initialize the variable. */; | |
683be2f7 JM |
99 | else if (type_uses_auto (type)) |
100 | /* We don't know the actual type yet. */; | |
2d76680f PC |
101 | else if (!literal_type_p (type)) |
102 | { | |
103 | if (DECL_DECLARED_CONSTEXPR_P (decl)) | |
f1eac182 | 104 | { |
097f82ec | 105 | auto_diagnostic_group d; |
f2935576 PC |
106 | error_at (DECL_SOURCE_LOCATION (decl), |
107 | "the type %qT of %<constexpr%> variable %qD " | |
108 | "is not literal", type, decl); | |
f1eac182 | 109 | explain_non_literal_class (type); |
9638f320 | 110 | decl = error_mark_node; |
f1eac182 | 111 | } |
2d76680f | 112 | else |
60813a46 | 113 | { |
5d4e573b | 114 | if (!is_instantiation_of_constexpr (current_function_decl)) |
f1eac182 | 115 | { |
097f82ec | 116 | auto_diagnostic_group d; |
f2935576 PC |
117 | error_at (DECL_SOURCE_LOCATION (decl), |
118 | "variable %qD of non-literal type %qT in " | |
119 | "%<constexpr%> function", decl, type); | |
f1eac182 | 120 | explain_non_literal_class (type); |
9638f320 | 121 | decl = error_mark_node; |
f1eac182 | 122 | } |
60813a46 JM |
123 | cp_function_chain->invalid_constexpr = true; |
124 | } | |
2d76680f | 125 | } |
8e9589bd JM |
126 | else if (DECL_DECLARED_CONSTEXPR_P (decl) |
127 | && variably_modified_type_p (type, NULL_TREE)) | |
128 | { | |
f2935576 PC |
129 | error_at (DECL_SOURCE_LOCATION (decl), |
130 | "%<constexpr%> variable %qD has variably-modified " | |
131 | "type %qT", decl, type); | |
8e9589bd JM |
132 | decl = error_mark_node; |
133 | } | |
2d76680f PC |
134 | } |
135 | return decl; | |
136 | } | |
137 | ||
138 | /* Representation of entries in the constexpr function definition table. */ | |
139 | ||
140 | struct GTY((for_user)) constexpr_fundef { | |
141 | tree decl; | |
142 | tree body; | |
43574e4f JJ |
143 | tree parms; |
144 | tree result; | |
2d76680f PC |
145 | }; |
146 | ||
ca752f39 | 147 | struct constexpr_fundef_hasher : ggc_ptr_hash<constexpr_fundef> |
2d76680f PC |
148 | { |
149 | static hashval_t hash (constexpr_fundef *); | |
150 | static bool equal (constexpr_fundef *, constexpr_fundef *); | |
151 | }; | |
152 | ||
153 | /* This table holds all constexpr function definitions seen in | |
154 | the current translation unit. */ | |
155 | ||
156 | static GTY (()) hash_table<constexpr_fundef_hasher> *constexpr_fundef_table; | |
157 | ||
158 | /* Utility function used for managing the constexpr function table. | |
159 | Return true if the entries pointed to by P and Q are for the | |
160 | same constexpr function. */ | |
161 | ||
162 | inline bool | |
163 | constexpr_fundef_hasher::equal (constexpr_fundef *lhs, constexpr_fundef *rhs) | |
164 | { | |
165 | return lhs->decl == rhs->decl; | |
166 | } | |
167 | ||
168 | /* Utility function used for managing the constexpr function table. | |
169 | Return a hash value for the entry pointed to by Q. */ | |
170 | ||
171 | inline hashval_t | |
172 | constexpr_fundef_hasher::hash (constexpr_fundef *fundef) | |
173 | { | |
174 | return DECL_UID (fundef->decl); | |
175 | } | |
176 | ||
177 | /* Return a previously saved definition of function FUN. */ | |
178 | ||
179 | static constexpr_fundef * | |
180 | retrieve_constexpr_fundef (tree fun) | |
181 | { | |
2d76680f PC |
182 | if (constexpr_fundef_table == NULL) |
183 | return NULL; | |
184 | ||
43574e4f | 185 | constexpr_fundef fundef = { fun, NULL, NULL, NULL }; |
2d76680f PC |
186 | return constexpr_fundef_table->find (&fundef); |
187 | } | |
188 | ||
189 | /* Check whether the parameter and return types of FUN are valid for a | |
190 | constexpr function, and complain if COMPLAIN. */ | |
191 | ||
98e5a19a | 192 | bool |
2d76680f PC |
193 | is_valid_constexpr_fn (tree fun, bool complain) |
194 | { | |
195 | bool ret = true; | |
196 | ||
31f7f784 | 197 | if (DECL_INHERITED_CTOR (fun) |
2d76680f PC |
198 | && TREE_CODE (fun) == TEMPLATE_DECL) |
199 | { | |
200 | ret = false; | |
201 | if (complain) | |
84fa214d | 202 | error ("inherited constructor %qD is not %<constexpr%>", |
31f7f784 | 203 | DECL_INHERITED_CTOR (fun)); |
2d76680f PC |
204 | } |
205 | else | |
206 | { | |
207 | for (tree parm = FUNCTION_FIRST_USER_PARM (fun); | |
208 | parm != NULL_TREE; parm = TREE_CHAIN (parm)) | |
209 | if (!literal_type_p (TREE_TYPE (parm))) | |
210 | { | |
211 | ret = false; | |
212 | if (complain) | |
213 | { | |
097f82ec | 214 | auto_diagnostic_group d; |
84fa214d | 215 | error ("invalid type for parameter %d of %<constexpr%> " |
2d76680f PC |
216 | "function %q+#D", DECL_PARM_INDEX (parm), fun); |
217 | explain_non_literal_class (TREE_TYPE (parm)); | |
218 | } | |
219 | } | |
220 | } | |
221 | ||
e1bea341 JM |
222 | if (LAMBDA_TYPE_P (CP_DECL_CONTEXT (fun)) && cxx_dialect < cxx17) |
223 | { | |
224 | ret = false; | |
225 | if (complain) | |
226 | inform (DECL_SOURCE_LOCATION (fun), | |
84fa214d | 227 | "lambdas are implicitly %<constexpr%> only in C++17 and later"); |
e1bea341 JM |
228 | } |
229 | else if (!DECL_CONSTRUCTOR_P (fun)) | |
2d76680f PC |
230 | { |
231 | tree rettype = TREE_TYPE (TREE_TYPE (fun)); | |
232 | if (!literal_type_p (rettype)) | |
233 | { | |
234 | ret = false; | |
235 | if (complain) | |
236 | { | |
097f82ec | 237 | auto_diagnostic_group d; |
84fa214d | 238 | error ("invalid return type %qT of %<constexpr%> function %q+D", |
2d76680f PC |
239 | rettype, fun); |
240 | explain_non_literal_class (rettype); | |
241 | } | |
242 | } | |
243 | ||
54069e59 JM |
244 | /* C++14 DR 1684 removed this restriction. */ |
245 | if (cxx_dialect < cxx14 | |
246 | && DECL_NONSTATIC_MEMBER_FUNCTION_P (fun) | |
2d76680f PC |
247 | && !CLASSTYPE_LITERAL_P (DECL_CONTEXT (fun))) |
248 | { | |
249 | ret = false; | |
097f82ec DM |
250 | if (complain) |
251 | { | |
252 | auto_diagnostic_group d; | |
253 | if (pedwarn (DECL_SOURCE_LOCATION (fun), OPT_Wpedantic, | |
254 | "enclosing class of %<constexpr%> non-static" | |
255 | " member function %q+#D is not a literal type", | |
256 | fun)) | |
257 | explain_non_literal_class (DECL_CONTEXT (fun)); | |
258 | } | |
2d76680f PC |
259 | } |
260 | } | |
261 | else if (CLASSTYPE_VBASECLASSES (DECL_CONTEXT (fun))) | |
262 | { | |
263 | ret = false; | |
264 | if (complain) | |
265 | error ("%q#T has virtual base classes", DECL_CONTEXT (fun)); | |
266 | } | |
267 | ||
268 | return ret; | |
269 | } | |
270 | ||
271 | /* Subroutine of build_data_member_initialization. MEMBER is a COMPONENT_REF | |
272 | for a member of an anonymous aggregate, INIT is the initializer for that | |
273 | member, and VEC_OUTER is the vector of constructor elements for the class | |
274 | whose constructor we are processing. Add the initializer to the vector | |
275 | and return true to indicate success. */ | |
276 | ||
277 | static bool | |
278 | build_anon_member_initialization (tree member, tree init, | |
279 | vec<constructor_elt, va_gc> **vec_outer) | |
280 | { | |
281 | /* MEMBER presents the relevant fields from the inside out, but we need | |
282 | to build up the initializer from the outside in so that we can reuse | |
283 | previously built CONSTRUCTORs if this is, say, the second field in an | |
284 | anonymous struct. So we use a vec as a stack. */ | |
285 | auto_vec<tree, 2> fields; | |
286 | do | |
287 | { | |
288 | fields.safe_push (TREE_OPERAND (member, 1)); | |
289 | member = TREE_OPERAND (member, 0); | |
290 | } | |
291 | while (ANON_AGGR_TYPE_P (TREE_TYPE (member)) | |
292 | && TREE_CODE (member) == COMPONENT_REF); | |
293 | ||
294 | /* VEC has the constructor elements vector for the context of FIELD. | |
295 | If FIELD is an anonymous aggregate, we will push inside it. */ | |
296 | vec<constructor_elt, va_gc> **vec = vec_outer; | |
297 | tree field; | |
298 | while (field = fields.pop(), | |
299 | ANON_AGGR_TYPE_P (TREE_TYPE (field))) | |
300 | { | |
301 | tree ctor; | |
302 | /* If there is already an outer constructor entry for the anonymous | |
303 | aggregate FIELD, use it; otherwise, insert one. */ | |
304 | if (vec_safe_is_empty (*vec) | |
305 | || (*vec)->last().index != field) | |
306 | { | |
307 | ctor = build_constructor (TREE_TYPE (field), NULL); | |
308 | CONSTRUCTOR_APPEND_ELT (*vec, field, ctor); | |
309 | } | |
310 | else | |
311 | ctor = (*vec)->last().value; | |
312 | vec = &CONSTRUCTOR_ELTS (ctor); | |
313 | } | |
314 | ||
315 | /* Now we're at the innermost field, the one that isn't an anonymous | |
316 | aggregate. Add its initializer to the CONSTRUCTOR and we're done. */ | |
317 | gcc_assert (fields.is_empty()); | |
318 | CONSTRUCTOR_APPEND_ELT (*vec, field, init); | |
319 | ||
320 | return true; | |
321 | } | |
322 | ||
323 | /* Subroutine of build_constexpr_constructor_member_initializers. | |
324 | The expression tree T represents a data member initialization | |
325 | in a (constexpr) constructor definition. Build a pairing of | |
326 | the data member with its initializer, and prepend that pair | |
327 | to the existing initialization pair INITS. */ | |
328 | ||
329 | static bool | |
330 | build_data_member_initialization (tree t, vec<constructor_elt, va_gc> **vec) | |
331 | { | |
332 | tree member, init; | |
333 | if (TREE_CODE (t) == CLEANUP_POINT_EXPR) | |
334 | t = TREE_OPERAND (t, 0); | |
335 | if (TREE_CODE (t) == EXPR_STMT) | |
336 | t = TREE_OPERAND (t, 0); | |
337 | if (t == error_mark_node) | |
338 | return false; | |
339 | if (TREE_CODE (t) == STATEMENT_LIST) | |
340 | { | |
341 | tree_stmt_iterator i; | |
342 | for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i)) | |
343 | { | |
344 | if (! build_data_member_initialization (tsi_stmt (i), vec)) | |
345 | return false; | |
346 | } | |
347 | return true; | |
348 | } | |
349 | if (TREE_CODE (t) == CLEANUP_STMT) | |
350 | { | |
351 | /* We can't see a CLEANUP_STMT in a constructor for a literal class, | |
352 | but we can in a constexpr constructor for a non-literal class. Just | |
353 | ignore it; either all the initialization will be constant, in which | |
354 | case the cleanup can't run, or it can't be constexpr. | |
355 | Still recurse into CLEANUP_BODY. */ | |
356 | return build_data_member_initialization (CLEANUP_BODY (t), vec); | |
357 | } | |
358 | if (TREE_CODE (t) == CONVERT_EXPR) | |
359 | t = TREE_OPERAND (t, 0); | |
360 | if (TREE_CODE (t) == INIT_EXPR | |
60813a46 JM |
361 | /* vptr initialization shows up as a MODIFY_EXPR. In C++14 we only |
362 | use what this function builds for cx_check_missing_mem_inits, and | |
363 | assignment in the ctor body doesn't count. */ | |
364 | || (cxx_dialect < cxx14 && TREE_CODE (t) == MODIFY_EXPR)) | |
2d76680f PC |
365 | { |
366 | member = TREE_OPERAND (t, 0); | |
367 | init = break_out_target_exprs (TREE_OPERAND (t, 1)); | |
368 | } | |
369 | else if (TREE_CODE (t) == CALL_EXPR) | |
370 | { | |
60813a46 JM |
371 | tree fn = get_callee_fndecl (t); |
372 | if (!fn || !DECL_CONSTRUCTOR_P (fn)) | |
373 | /* We're only interested in calls to subobject constructors. */ | |
374 | return true; | |
2d76680f PC |
375 | member = CALL_EXPR_ARG (t, 0); |
376 | /* We don't use build_cplus_new here because it complains about | |
377 | abstract bases. Leaving the call unwrapped means that it has the | |
378 | wrong type, but cxx_eval_constant_expression doesn't care. */ | |
379 | init = break_out_target_exprs (t); | |
380 | } | |
381 | else if (TREE_CODE (t) == BIND_EXPR) | |
382 | return build_data_member_initialization (BIND_EXPR_BODY (t), vec); | |
2d76680f | 383 | else |
60813a46 JM |
384 | /* Don't add anything else to the CONSTRUCTOR. */ |
385 | return true; | |
2d76680f PC |
386 | if (INDIRECT_REF_P (member)) |
387 | member = TREE_OPERAND (member, 0); | |
388 | if (TREE_CODE (member) == NOP_EXPR) | |
389 | { | |
390 | tree op = member; | |
391 | STRIP_NOPS (op); | |
392 | if (TREE_CODE (op) == ADDR_EXPR) | |
393 | { | |
394 | gcc_assert (same_type_ignoring_top_level_qualifiers_p | |
395 | (TREE_TYPE (TREE_TYPE (op)), | |
396 | TREE_TYPE (TREE_TYPE (member)))); | |
397 | /* Initializing a cv-qualified member; we need to look through | |
398 | the const_cast. */ | |
399 | member = op; | |
400 | } | |
401 | else if (op == current_class_ptr | |
402 | && (same_type_ignoring_top_level_qualifiers_p | |
403 | (TREE_TYPE (TREE_TYPE (member)), | |
404 | current_class_type))) | |
405 | /* Delegating constructor. */ | |
406 | member = op; | |
407 | else | |
408 | { | |
409 | /* This is an initializer for an empty base; keep it for now so | |
410 | we can check it in cxx_eval_bare_aggregate. */ | |
411 | gcc_assert (is_empty_class (TREE_TYPE (TREE_TYPE (member)))); | |
412 | } | |
413 | } | |
414 | if (TREE_CODE (member) == ADDR_EXPR) | |
415 | member = TREE_OPERAND (member, 0); | |
416 | if (TREE_CODE (member) == COMPONENT_REF) | |
417 | { | |
418 | tree aggr = TREE_OPERAND (member, 0); | |
8cb7aaa1 JM |
419 | if (TREE_CODE (aggr) == VAR_DECL) |
420 | /* Initializing a local variable, don't add anything. */ | |
421 | return true; | |
2d76680f PC |
422 | if (TREE_CODE (aggr) != COMPONENT_REF) |
423 | /* Normal member initialization. */ | |
424 | member = TREE_OPERAND (member, 1); | |
425 | else if (ANON_AGGR_TYPE_P (TREE_TYPE (aggr))) | |
426 | /* Initializing a member of an anonymous union. */ | |
427 | return build_anon_member_initialization (member, init, vec); | |
428 | else | |
429 | /* We're initializing a vtable pointer in a base. Leave it as | |
430 | COMPONENT_REF so we remember the path to get to the vfield. */ | |
431 | gcc_assert (TREE_TYPE (member) == vtbl_ptr_type_node); | |
432 | } | |
433 | ||
49b5925f JM |
434 | /* Value-initialization can produce multiple initializers for the |
435 | same field; use the last one. */ | |
436 | if (!vec_safe_is_empty (*vec) && (*vec)->last().index == member) | |
437 | (*vec)->last().value = init; | |
438 | else | |
439 | CONSTRUCTOR_APPEND_ELT (*vec, member, init); | |
2d76680f PC |
440 | return true; |
441 | } | |
442 | ||
443 | /* Subroutine of check_constexpr_ctor_body_1 and constexpr_fn_retval. | |
444 | In C++11 mode checks that the TYPE_DECLs in the BIND_EXPR_VARS of a | |
445 | BIND_EXPR conform to 7.1.5/3/4 on typedef and alias declarations. */ | |
446 | ||
447 | static bool | |
448 | check_constexpr_bind_expr_vars (tree t) | |
449 | { | |
450 | gcc_assert (TREE_CODE (t) == BIND_EXPR); | |
451 | ||
2d76680f PC |
452 | for (tree var = BIND_EXPR_VARS (t); var; var = DECL_CHAIN (var)) |
453 | if (TREE_CODE (var) == TYPE_DECL | |
4414e22e PC |
454 | && DECL_IMPLICIT_TYPEDEF_P (var) |
455 | && !LAMBDA_TYPE_P (TREE_TYPE (var))) | |
2d76680f PC |
456 | return false; |
457 | return true; | |
458 | } | |
459 | ||
460 | /* Subroutine of check_constexpr_ctor_body. */ | |
461 | ||
462 | static bool | |
463 | check_constexpr_ctor_body_1 (tree last, tree list) | |
464 | { | |
465 | switch (TREE_CODE (list)) | |
466 | { | |
467 | case DECL_EXPR: | |
a0008434 MP |
468 | if (TREE_CODE (DECL_EXPR_DECL (list)) == USING_DECL |
469 | || TREE_CODE (DECL_EXPR_DECL (list)) == TYPE_DECL) | |
2d76680f | 470 | return true; |
2d76680f PC |
471 | return false; |
472 | ||
473 | case CLEANUP_POINT_EXPR: | |
474 | return check_constexpr_ctor_body (last, TREE_OPERAND (list, 0), | |
475 | /*complain=*/false); | |
476 | ||
477 | case BIND_EXPR: | |
478 | if (!check_constexpr_bind_expr_vars (list) | |
479 | || !check_constexpr_ctor_body (last, BIND_EXPR_BODY (list), | |
480 | /*complain=*/false)) | |
481 | return false; | |
482 | return true; | |
483 | ||
484 | case USING_STMT: | |
485 | case STATIC_ASSERT: | |
96a95ac1 | 486 | case DEBUG_BEGIN_STMT: |
2d76680f PC |
487 | return true; |
488 | ||
489 | default: | |
490 | return false; | |
491 | } | |
492 | } | |
493 | ||
494 | /* Make sure that there are no statements after LAST in the constructor | |
495 | body represented by LIST. */ | |
496 | ||
497 | bool | |
498 | check_constexpr_ctor_body (tree last, tree list, bool complain) | |
499 | { | |
60813a46 JM |
500 | /* C++14 doesn't require a constexpr ctor to have an empty body. */ |
501 | if (cxx_dialect >= cxx14) | |
502 | return true; | |
503 | ||
2d76680f PC |
504 | bool ok = true; |
505 | if (TREE_CODE (list) == STATEMENT_LIST) | |
506 | { | |
507 | tree_stmt_iterator i = tsi_last (list); | |
508 | for (; !tsi_end_p (i); tsi_prev (&i)) | |
509 | { | |
510 | tree t = tsi_stmt (i); | |
511 | if (t == last) | |
512 | break; | |
513 | if (!check_constexpr_ctor_body_1 (last, t)) | |
514 | { | |
515 | ok = false; | |
516 | break; | |
517 | } | |
518 | } | |
519 | } | |
520 | else if (list != last | |
521 | && !check_constexpr_ctor_body_1 (last, list)) | |
522 | ok = false; | |
523 | if (!ok) | |
524 | { | |
525 | if (complain) | |
84fa214d | 526 | error ("%<constexpr%> constructor does not have empty body"); |
2d76680f PC |
527 | DECL_DECLARED_CONSTEXPR_P (current_function_decl) = false; |
528 | } | |
529 | return ok; | |
530 | } | |
531 | ||
532 | /* V is a vector of constructor elements built up for the base and member | |
533 | initializers of a constructor for TYPE. They need to be in increasing | |
534 | offset order, which they might not be yet if TYPE has a primary base | |
535 | which is not first in the base-clause or a vptr and at least one base | |
536 | all of which are non-primary. */ | |
537 | ||
538 | static vec<constructor_elt, va_gc> * | |
539 | sort_constexpr_mem_initializers (tree type, vec<constructor_elt, va_gc> *v) | |
540 | { | |
541 | tree pri = CLASSTYPE_PRIMARY_BINFO (type); | |
542 | tree field_type; | |
543 | unsigned i; | |
544 | constructor_elt *ce; | |
545 | ||
546 | if (pri) | |
547 | field_type = BINFO_TYPE (pri); | |
548 | else if (TYPE_CONTAINS_VPTR_P (type)) | |
549 | field_type = vtbl_ptr_type_node; | |
550 | else | |
551 | return v; | |
552 | ||
553 | /* Find the element for the primary base or vptr and move it to the | |
554 | beginning of the vec. */ | |
555 | for (i = 0; vec_safe_iterate (v, i, &ce); ++i) | |
556 | if (TREE_TYPE (ce->index) == field_type) | |
557 | break; | |
558 | ||
559 | if (i > 0 && i < vec_safe_length (v)) | |
560 | { | |
561 | vec<constructor_elt, va_gc> &vref = *v; | |
562 | constructor_elt elt = vref[i]; | |
563 | for (; i > 0; --i) | |
564 | vref[i] = vref[i-1]; | |
565 | vref[0] = elt; | |
566 | } | |
567 | ||
568 | return v; | |
569 | } | |
570 | ||
571 | /* Build compile-time evalable representations of member-initializer list | |
572 | for a constexpr constructor. */ | |
573 | ||
574 | static tree | |
575 | build_constexpr_constructor_member_initializers (tree type, tree body) | |
576 | { | |
577 | vec<constructor_elt, va_gc> *vec = NULL; | |
578 | bool ok = true; | |
fa837fb6 JM |
579 | while (true) |
580 | switch (TREE_CODE (body)) | |
581 | { | |
582 | case MUST_NOT_THROW_EXPR: | |
583 | case EH_SPEC_BLOCK: | |
584 | body = TREE_OPERAND (body, 0); | |
585 | break; | |
586 | ||
587 | case STATEMENT_LIST: | |
588 | for (tree_stmt_iterator i = tsi_start (body); | |
589 | !tsi_end_p (i); tsi_next (&i)) | |
590 | { | |
591 | body = tsi_stmt (i); | |
592 | if (TREE_CODE (body) == BIND_EXPR) | |
593 | break; | |
594 | } | |
595 | break; | |
596 | ||
597 | case BIND_EXPR: | |
598 | body = BIND_EXPR_BODY (body); | |
599 | goto found; | |
600 | ||
601 | default: | |
602 | gcc_unreachable (); | |
58cc255c | 603 | } |
fa837fb6 | 604 | found: |
1259cb6d JJ |
605 | if (TREE_CODE (body) == TRY_BLOCK) |
606 | { | |
607 | body = TREE_OPERAND (body, 0); | |
608 | if (TREE_CODE (body) == BIND_EXPR) | |
609 | body = BIND_EXPR_BODY (body); | |
610 | } | |
2d76680f PC |
611 | if (TREE_CODE (body) == CLEANUP_POINT_EXPR) |
612 | { | |
613 | body = TREE_OPERAND (body, 0); | |
614 | if (TREE_CODE (body) == EXPR_STMT) | |
615 | body = TREE_OPERAND (body, 0); | |
616 | if (TREE_CODE (body) == INIT_EXPR | |
617 | && (same_type_ignoring_top_level_qualifiers_p | |
618 | (TREE_TYPE (TREE_OPERAND (body, 0)), | |
619 | current_class_type))) | |
620 | { | |
621 | /* Trivial copy. */ | |
622 | return TREE_OPERAND (body, 1); | |
623 | } | |
624 | ok = build_data_member_initialization (body, &vec); | |
625 | } | |
626 | else if (TREE_CODE (body) == STATEMENT_LIST) | |
627 | { | |
628 | tree_stmt_iterator i; | |
629 | for (i = tsi_start (body); !tsi_end_p (i); tsi_next (&i)) | |
630 | { | |
631 | ok = build_data_member_initialization (tsi_stmt (i), &vec); | |
632 | if (!ok) | |
633 | break; | |
634 | } | |
635 | } | |
2d76680f PC |
636 | else if (EXPR_P (body)) |
637 | ok = build_data_member_initialization (body, &vec); | |
638 | else | |
639 | gcc_assert (errorcount > 0); | |
640 | if (ok) | |
641 | { | |
642 | if (vec_safe_length (vec) > 0) | |
643 | { | |
644 | /* In a delegating constructor, return the target. */ | |
645 | constructor_elt *ce = &(*vec)[0]; | |
646 | if (ce->index == current_class_ptr) | |
647 | { | |
648 | body = ce->value; | |
649 | vec_free (vec); | |
650 | return body; | |
651 | } | |
652 | } | |
653 | vec = sort_constexpr_mem_initializers (type, vec); | |
654 | return build_constructor (type, vec); | |
655 | } | |
656 | else | |
657 | return error_mark_node; | |
658 | } | |
659 | ||
1b6fa695 ML |
660 | /* We have an expression tree T that represents a call, either CALL_EXPR |
661 | or AGGR_INIT_EXPR. If the call is lexically to a named function, | |
662 | retrun the _DECL for that function. */ | |
663 | ||
664 | static tree | |
665 | get_function_named_in_call (tree t) | |
666 | { | |
667 | tree fun = cp_get_callee (t); | |
668 | if (fun && TREE_CODE (fun) == ADDR_EXPR | |
669 | && TREE_CODE (TREE_OPERAND (fun, 0)) == FUNCTION_DECL) | |
670 | fun = TREE_OPERAND (fun, 0); | |
671 | return fun; | |
672 | } | |
673 | ||
2d76680f PC |
674 | /* Subroutine of register_constexpr_fundef. BODY is the body of a function |
675 | declared to be constexpr, or a sub-statement thereof. Returns the | |
676 | return value if suitable, error_mark_node for a statement not allowed in | |
677 | a constexpr function, or NULL_TREE if no return value was found. */ | |
678 | ||
5afef8b1 | 679 | tree |
2d76680f PC |
680 | constexpr_fn_retval (tree body) |
681 | { | |
682 | switch (TREE_CODE (body)) | |
683 | { | |
684 | case STATEMENT_LIST: | |
685 | { | |
686 | tree_stmt_iterator i; | |
687 | tree expr = NULL_TREE; | |
688 | for (i = tsi_start (body); !tsi_end_p (i); tsi_next (&i)) | |
689 | { | |
690 | tree s = constexpr_fn_retval (tsi_stmt (i)); | |
691 | if (s == error_mark_node) | |
692 | return error_mark_node; | |
693 | else if (s == NULL_TREE) | |
694 | /* Keep iterating. */; | |
695 | else if (expr) | |
696 | /* Multiple return statements. */ | |
697 | return error_mark_node; | |
698 | else | |
699 | expr = s; | |
700 | } | |
701 | return expr; | |
702 | } | |
703 | ||
704 | case RETURN_EXPR: | |
705 | return break_out_target_exprs (TREE_OPERAND (body, 0)); | |
706 | ||
707 | case DECL_EXPR: | |
0162cb3b PC |
708 | { |
709 | tree decl = DECL_EXPR_DECL (body); | |
710 | if (TREE_CODE (decl) == USING_DECL | |
711 | /* Accept __func__, __FUNCTION__, and __PRETTY_FUNCTION__. */ | |
712 | || DECL_ARTIFICIAL (decl)) | |
713 | return NULL_TREE; | |
714 | return error_mark_node; | |
715 | } | |
2d76680f PC |
716 | |
717 | case CLEANUP_POINT_EXPR: | |
718 | return constexpr_fn_retval (TREE_OPERAND (body, 0)); | |
719 | ||
720 | case BIND_EXPR: | |
721 | if (!check_constexpr_bind_expr_vars (body)) | |
722 | return error_mark_node; | |
723 | return constexpr_fn_retval (BIND_EXPR_BODY (body)); | |
724 | ||
725 | case USING_STMT: | |
96a95ac1 | 726 | case DEBUG_BEGIN_STMT: |
2d76680f PC |
727 | return NULL_TREE; |
728 | ||
1b6fa695 ML |
729 | case CALL_EXPR: |
730 | { | |
731 | tree fun = get_function_named_in_call (body); | |
732 | if (fun != NULL_TREE | |
3d78e008 | 733 | && fndecl_built_in_p (fun, BUILT_IN_UNREACHABLE)) |
1b6fa695 ML |
734 | return NULL_TREE; |
735 | } | |
736 | /* Fallthru. */ | |
737 | ||
2d76680f PC |
738 | default: |
739 | return error_mark_node; | |
740 | } | |
741 | } | |
742 | ||
743 | /* Subroutine of register_constexpr_fundef. BODY is the DECL_SAVED_TREE of | |
744 | FUN; do the necessary transformations to turn it into a single expression | |
745 | that we can store in the hash table. */ | |
746 | ||
747 | static tree | |
748 | massage_constexpr_body (tree fun, tree body) | |
749 | { | |
750 | if (DECL_CONSTRUCTOR_P (fun)) | |
751 | body = build_constexpr_constructor_member_initializers | |
752 | (DECL_CONTEXT (fun), body); | |
60813a46 | 753 | else if (cxx_dialect < cxx14) |
2d76680f PC |
754 | { |
755 | if (TREE_CODE (body) == EH_SPEC_BLOCK) | |
756 | body = EH_SPEC_STMTS (body); | |
757 | if (TREE_CODE (body) == MUST_NOT_THROW_EXPR) | |
758 | body = TREE_OPERAND (body, 0); | |
759 | body = constexpr_fn_retval (body); | |
760 | } | |
761 | return body; | |
762 | } | |
763 | ||
3e4b91f2 NS |
764 | /* CTYPE is a type constructed from BODY. Return true if some |
765 | bases/fields are uninitialized, and complain if COMPLAIN. */ | |
2d76680f PC |
766 | |
767 | static bool | |
3e4b91f2 | 768 | cx_check_missing_mem_inits (tree ctype, tree body, bool complain) |
2d76680f | 769 | { |
3e4b91f2 NS |
770 | unsigned nelts = 0; |
771 | ||
772 | if (body) | |
773 | { | |
774 | if (TREE_CODE (body) != CONSTRUCTOR) | |
775 | return false; | |
776 | nelts = CONSTRUCTOR_NELTS (body); | |
777 | } | |
778 | tree field = TYPE_FIELDS (ctype); | |
2d76680f PC |
779 | |
780 | if (TREE_CODE (ctype) == UNION_TYPE) | |
781 | { | |
782 | if (nelts == 0 && next_initializable_field (field)) | |
783 | { | |
784 | if (complain) | |
785 | error ("%<constexpr%> constructor for union %qT must " | |
786 | "initialize exactly one non-static data member", ctype); | |
787 | return true; | |
788 | } | |
789 | return false; | |
790 | } | |
791 | ||
3e4b91f2 NS |
792 | /* Iterate over the CONSTRUCTOR, checking any missing fields don't |
793 | need an explicit initialization. */ | |
794 | bool bad = false; | |
795 | for (unsigned i = 0; i <= nelts; ++i) | |
2d76680f | 796 | { |
3e4b91f2 NS |
797 | tree index = NULL_TREE; |
798 | if (i < nelts) | |
2d76680f PC |
799 | { |
800 | index = CONSTRUCTOR_ELT (body, i)->index; | |
801 | /* Skip base and vtable inits. */ | |
802 | if (TREE_CODE (index) != FIELD_DECL | |
803 | || DECL_ARTIFICIAL (index)) | |
804 | continue; | |
805 | } | |
3e4b91f2 | 806 | |
2d76680f PC |
807 | for (; field != index; field = DECL_CHAIN (field)) |
808 | { | |
809 | tree ftype; | |
3e4b91f2 NS |
810 | if (TREE_CODE (field) != FIELD_DECL) |
811 | continue; | |
7c30b12a | 812 | if (DECL_UNNAMED_BIT_FIELD (field)) |
2d76680f | 813 | continue; |
3e4b91f2 NS |
814 | if (DECL_ARTIFICIAL (field)) |
815 | continue; | |
816 | if (ANON_AGGR_TYPE_P (TREE_TYPE (field))) | |
817 | { | |
818 | /* Recurse to check the anonummous aggregate member. */ | |
819 | bad |= cx_check_missing_mem_inits | |
820 | (TREE_TYPE (field), NULL_TREE, complain); | |
821 | if (bad && !complain) | |
822 | return true; | |
823 | continue; | |
824 | } | |
2d76680f PC |
825 | ftype = strip_array_types (TREE_TYPE (field)); |
826 | if (type_has_constexpr_default_constructor (ftype)) | |
827 | { | |
828 | /* It's OK to skip a member with a trivial constexpr ctor. | |
829 | A constexpr ctor that isn't trivial should have been | |
830 | added in by now. */ | |
831 | gcc_checking_assert (!TYPE_HAS_COMPLEX_DFLT (ftype) | |
832 | || errorcount != 0); | |
833 | continue; | |
834 | } | |
835 | if (!complain) | |
836 | return true; | |
097f82ec | 837 | auto_diagnostic_group d; |
b8cd3996 JM |
838 | error ("member %qD must be initialized by mem-initializer " |
839 | "in %<constexpr%> constructor", field); | |
840 | inform (DECL_SOURCE_LOCATION (field), "declared here"); | |
2d76680f PC |
841 | bad = true; |
842 | } | |
843 | if (field == NULL_TREE) | |
844 | break; | |
3e4b91f2 NS |
845 | |
846 | if (ANON_AGGR_TYPE_P (TREE_TYPE (index))) | |
847 | { | |
848 | /* Check the anonymous aggregate initializer is valid. */ | |
849 | bad |= cx_check_missing_mem_inits | |
850 | (TREE_TYPE (index), CONSTRUCTOR_ELT (body, i)->value, complain); | |
851 | if (bad && !complain) | |
852 | return true; | |
853 | } | |
2d76680f PC |
854 | field = DECL_CHAIN (field); |
855 | } | |
856 | ||
857 | return bad; | |
858 | } | |
859 | ||
860 | /* We are processing the definition of the constexpr function FUN. | |
861 | Check that its BODY fulfills the propriate requirements and | |
862 | enter it in the constexpr function definition table. | |
863 | For constructor BODY is actually the TREE_LIST of the | |
864 | member-initializer list. */ | |
865 | ||
866 | tree | |
867 | register_constexpr_fundef (tree fun, tree body) | |
868 | { | |
869 | constexpr_fundef entry; | |
870 | constexpr_fundef **slot; | |
871 | ||
872 | if (!is_valid_constexpr_fn (fun, !DECL_GENERATED_P (fun))) | |
873 | return NULL; | |
874 | ||
ca30abcd JM |
875 | tree massaged = massage_constexpr_body (fun, body); |
876 | if (massaged == NULL_TREE || massaged == error_mark_node) | |
2d76680f PC |
877 | { |
878 | if (!DECL_CONSTRUCTOR_P (fun)) | |
84fa214d ML |
879 | error ("body of %<constexpr%> function %qD not a return-statement", |
880 | fun); | |
2d76680f PC |
881 | return NULL; |
882 | } | |
883 | ||
ca30abcd | 884 | if (!potential_rvalue_constant_expression (massaged)) |
2d76680f PC |
885 | { |
886 | if (!DECL_GENERATED_P (fun)) | |
ca30abcd | 887 | require_potential_rvalue_constant_expression (massaged); |
2d76680f PC |
888 | return NULL; |
889 | } | |
890 | ||
891 | if (DECL_CONSTRUCTOR_P (fun) | |
3e4b91f2 NS |
892 | && cx_check_missing_mem_inits (DECL_CONTEXT (fun), |
893 | massaged, !DECL_GENERATED_P (fun))) | |
2d76680f PC |
894 | return NULL; |
895 | ||
896 | /* Create the constexpr function table if necessary. */ | |
897 | if (constexpr_fundef_table == NULL) | |
898 | constexpr_fundef_table | |
899 | = hash_table<constexpr_fundef_hasher>::create_ggc (101); | |
900 | ||
901 | entry.decl = fun; | |
43574e4f JJ |
902 | tree saved_fn = current_function_decl; |
903 | bool clear_ctx = false; | |
904 | current_function_decl = fun; | |
905 | if (DECL_RESULT (fun) && DECL_CONTEXT (DECL_RESULT (fun)) == NULL_TREE) | |
906 | { | |
907 | clear_ctx = true; | |
908 | DECL_CONTEXT (DECL_RESULT (fun)) = fun; | |
909 | } | |
910 | entry.body = copy_fn (fun, entry.parms, entry.result); | |
911 | current_function_decl = saved_fn; | |
2d76680f | 912 | slot = constexpr_fundef_table->find_slot (&entry, INSERT); |
43574e4f JJ |
913 | if (clear_ctx) |
914 | DECL_CONTEXT (DECL_RESULT (fun)) = NULL_TREE; | |
2d76680f PC |
915 | |
916 | gcc_assert (*slot == NULL); | |
917 | *slot = ggc_alloc<constexpr_fundef> (); | |
918 | **slot = entry; | |
919 | ||
920 | return fun; | |
921 | } | |
922 | ||
923 | /* FUN is a non-constexpr function called in a context that requires a | |
924 | constant expression. If it comes from a constexpr template, explain why | |
925 | the instantiation isn't constexpr. */ | |
926 | ||
927 | void | |
928 | explain_invalid_constexpr_fn (tree fun) | |
929 | { | |
930 | static hash_set<tree> *diagnosed; | |
931 | tree body; | |
932 | location_t save_loc; | |
98e5a19a | 933 | /* Only diagnose defaulted functions, lambdas, or instantiations. */ |
2d76680f | 934 | if (!DECL_DEFAULTED_FN (fun) |
98e5a19a | 935 | && !LAMBDA_TYPE_P (CP_DECL_CONTEXT (fun)) |
2d76680f PC |
936 | && !is_instantiation_of_constexpr (fun)) |
937 | return; | |
938 | if (diagnosed == NULL) | |
939 | diagnosed = new hash_set<tree>; | |
940 | if (diagnosed->add (fun)) | |
941 | /* Already explained. */ | |
942 | return; | |
943 | ||
944 | save_loc = input_location; | |
98e5a19a JM |
945 | if (!lambda_static_thunk_p (fun)) |
946 | { | |
947 | /* Diagnostics should completely ignore the static thunk, so leave | |
948 | input_location set to our caller's location. */ | |
949 | input_location = DECL_SOURCE_LOCATION (fun); | |
950 | inform (input_location, | |
84fa214d | 951 | "%qD is not usable as a %<constexpr%> function because:", fun); |
98e5a19a | 952 | } |
2d76680f PC |
953 | /* First check the declaration. */ |
954 | if (is_valid_constexpr_fn (fun, true)) | |
955 | { | |
956 | /* Then if it's OK, the body. */ | |
98e5a19a JM |
957 | if (!DECL_DECLARED_CONSTEXPR_P (fun) |
958 | && !LAMBDA_TYPE_P (CP_DECL_CONTEXT (fun))) | |
2d76680f PC |
959 | explain_implicit_non_constexpr (fun); |
960 | else | |
961 | { | |
962 | body = massage_constexpr_body (fun, DECL_SAVED_TREE (fun)); | |
963 | require_potential_rvalue_constant_expression (body); | |
964 | if (DECL_CONSTRUCTOR_P (fun)) | |
3e4b91f2 | 965 | cx_check_missing_mem_inits (DECL_CONTEXT (fun), body, true); |
2d76680f PC |
966 | } |
967 | } | |
968 | input_location = save_loc; | |
969 | } | |
970 | ||
971 | /* Objects of this type represent calls to constexpr functions | |
972 | along with the bindings of parameters to their arguments, for | |
973 | the purpose of compile time evaluation. */ | |
974 | ||
975 | struct GTY((for_user)) constexpr_call { | |
976 | /* Description of the constexpr function definition. */ | |
977 | constexpr_fundef *fundef; | |
3c961dc7 | 978 | /* Parameter bindings environment. A TREE_VEC of arguments. */ |
2d76680f PC |
979 | tree bindings; |
980 | /* Result of the call. | |
981 | NULL means the call is being evaluated. | |
982 | error_mark_node means that the evaluation was erroneous; | |
983 | otherwise, the actuall value of the call. */ | |
984 | tree result; | |
985 | /* The hash of this call; we remember it here to avoid having to | |
986 | recalculate it when expanding the hash table. */ | |
987 | hashval_t hash; | |
cce3ae91 | 988 | /* Whether __builtin_is_constant_evaluated() should evaluate to true. */ |
13de99bc | 989 | bool manifestly_const_eval; |
2d76680f PC |
990 | }; |
991 | ||
ca752f39 | 992 | struct constexpr_call_hasher : ggc_ptr_hash<constexpr_call> |
2d76680f PC |
993 | { |
994 | static hashval_t hash (constexpr_call *); | |
995 | static bool equal (constexpr_call *, constexpr_call *); | |
3e605b20 JM |
996 | }; |
997 | ||
4b390698 JJ |
998 | enum constexpr_switch_state { |
999 | /* Used when processing a switch for the first time by cxx_eval_switch_expr | |
1000 | and default: label for that switch has not been seen yet. */ | |
1001 | css_default_not_seen, | |
1002 | /* Used when processing a switch for the first time by cxx_eval_switch_expr | |
1003 | and default: label for that switch has been seen already. */ | |
1004 | css_default_seen, | |
1005 | /* Used when processing a switch for the second time by | |
1006 | cxx_eval_switch_expr, where default: label should match. */ | |
1007 | css_default_processing | |
1008 | }; | |
1009 | ||
8e007055 JJ |
1010 | /* The constexpr expansion context part which needs one instance per |
1011 | cxx_eval_outermost_constant_expr invocation. VALUES is a map of values of | |
1012 | variables initialized within the expression. */ | |
1013 | ||
1014 | struct constexpr_global_ctx { | |
1015 | /* Values for any temporaries or local variables within the | |
1016 | constant-expression. */ | |
1017 | hash_map<tree,tree> values; | |
1018 | /* Number of cxx_eval_constant_expression calls (except skipped ones, | |
1019 | on simple constants or location wrappers) encountered during current | |
1020 | cxx_eval_outermost_constant_expr call. */ | |
1021 | HOST_WIDE_INT constexpr_ops_count; | |
1022 | /* Heap VAR_DECLs created during the evaluation of the outermost constant | |
1023 | expression. */ | |
1024 | auto_vec<tree, 16> heap_vars; | |
1025 | /* Constructor. */ | |
1026 | constexpr_global_ctx () : constexpr_ops_count (0) {} | |
1027 | }; | |
1028 | ||
3e605b20 JM |
1029 | /* The constexpr expansion context. CALL is the current function |
1030 | expansion, CTOR is the current aggregate initializer, OBJECT is the | |
8e007055 | 1031 | object being initialized by CTOR, either a VAR_DECL or a _REF. */ |
3e605b20 JM |
1032 | |
1033 | struct constexpr_ctx { | |
8e007055 JJ |
1034 | /* The part of the context that needs to be unique to the whole |
1035 | cxx_eval_outermost_constant_expr invocation. */ | |
1036 | constexpr_global_ctx *global; | |
13f649f6 | 1037 | /* The innermost call we're evaluating. */ |
3e605b20 | 1038 | constexpr_call *call; |
39dce2b7 JM |
1039 | /* SAVE_EXPRs that we've seen within the current LOOP_EXPR. NULL if we |
1040 | aren't inside a loop. */ | |
0ee28590 | 1041 | vec<tree> *save_exprs; |
13f649f6 JM |
1042 | /* The CONSTRUCTOR we're currently building up for an aggregate |
1043 | initializer. */ | |
3e605b20 | 1044 | tree ctor; |
13f649f6 | 1045 | /* The object we're building the CONSTRUCTOR for. */ |
3e605b20 | 1046 | tree object; |
4b390698 JJ |
1047 | /* If inside SWITCH_EXPR. */ |
1048 | constexpr_switch_state *css_state; | |
a15ffa22 | 1049 | |
13f649f6 | 1050 | /* Whether we should error on a non-constant expression or fail quietly. */ |
2b3ab879 | 1051 | bool quiet; |
13f649f6 JM |
1052 | /* Whether we are strictly conforming to constant expression rules or |
1053 | trying harder to get a constant value. */ | |
69eb4fde | 1054 | bool strict; |
e4082611 | 1055 | /* Whether __builtin_is_constant_evaluated () should be true. */ |
13de99bc | 1056 | bool manifestly_const_eval; |
3e605b20 | 1057 | }; |
2d76680f PC |
1058 | |
1059 | /* A table of all constexpr calls that have been evaluated by the | |
1060 | compiler in this translation unit. */ | |
1061 | ||
97f3003f | 1062 | static GTY (()) hash_table<constexpr_call_hasher> *constexpr_call_table; |
2d76680f | 1063 | |
3e605b20 | 1064 | static tree cxx_eval_constant_expression (const constexpr_ctx *, tree, |
5a804683 | 1065 | bool, bool *, bool *, tree * = NULL); |
2d76680f PC |
1066 | |
1067 | /* Compute a hash value for a constexpr call representation. */ | |
1068 | ||
1069 | inline hashval_t | |
1070 | constexpr_call_hasher::hash (constexpr_call *info) | |
1071 | { | |
1072 | return info->hash; | |
1073 | } | |
1074 | ||
1075 | /* Return true if the objects pointed to by P and Q represent calls | |
1076 | to the same constexpr function with the same arguments. | |
1077 | Otherwise, return false. */ | |
1078 | ||
1079 | bool | |
1080 | constexpr_call_hasher::equal (constexpr_call *lhs, constexpr_call *rhs) | |
1081 | { | |
2d76680f | 1082 | if (lhs == rhs) |
46cf7fa1 JJ |
1083 | return true; |
1084 | if (lhs->hash != rhs->hash) | |
1085 | return false; | |
13de99bc | 1086 | if (lhs->manifestly_const_eval != rhs->manifestly_const_eval) |
cce3ae91 | 1087 | return false; |
2d76680f | 1088 | if (!constexpr_fundef_hasher::equal (lhs->fundef, rhs->fundef)) |
46cf7fa1 | 1089 | return false; |
3c961dc7 | 1090 | return cp_tree_equal (lhs->bindings, rhs->bindings); |
2d76680f PC |
1091 | } |
1092 | ||
1093 | /* Initialize the constexpr call table, if needed. */ | |
1094 | ||
1095 | static void | |
1096 | maybe_initialize_constexpr_call_table (void) | |
1097 | { | |
1098 | if (constexpr_call_table == NULL) | |
1099 | constexpr_call_table = hash_table<constexpr_call_hasher>::create_ggc (101); | |
1100 | } | |
1101 | ||
c0daf32d PP |
1102 | /* During constexpr CALL_EXPR evaluation, to avoid issues with sharing when |
1103 | a function happens to get called recursively, we unshare the callee | |
1104 | function's body and evaluate this unshared copy instead of evaluating the | |
1105 | original body. | |
1106 | ||
1107 | FUNDEF_COPIES_TABLE is a per-function freelist of these unshared function | |
1108 | copies. The underlying data structure of FUNDEF_COPIES_TABLE is a hash_map | |
97f3003f JM |
1109 | that's keyed off of the original FUNCTION_DECL and whose value is a |
1110 | TREE_LIST of this function's unused copies awaiting reuse. | |
c0daf32d | 1111 | |
97f3003f | 1112 | This is not GC-deletable to avoid GC affecting UID generation. */ |
c0daf32d | 1113 | |
97f3003f | 1114 | static GTY(()) hash_map<tree, tree> *fundef_copies_table; |
c0daf32d | 1115 | |
c0daf32d | 1116 | /* Reuse a copy or create a new unshared copy of the function FUN. |
3c98ff9b NS |
1117 | Return this copy. We use a TREE_LIST whose PURPOSE is body, VALUE |
1118 | is parms, TYPE is result. */ | |
c0daf32d | 1119 | |
97f3003f | 1120 | static tree |
43574e4f | 1121 | get_fundef_copy (constexpr_fundef *fundef) |
c0daf32d | 1122 | { |
97f3003f | 1123 | tree copy; |
3c98ff9b | 1124 | bool existed; |
c89844e5 JM |
1125 | tree *slot = &(hash_map_safe_get_or_insert<hm_ggc> |
1126 | (fundef_copies_table, fundef->decl, &existed, 127)); | |
3c98ff9b NS |
1127 | |
1128 | if (!existed) | |
c0daf32d | 1129 | { |
3c98ff9b NS |
1130 | /* There is no cached function available, or in use. We can use |
1131 | the function directly. That the slot is now created records | |
1132 | that this function is now in use. */ | |
43574e4f JJ |
1133 | copy = build_tree_list (fundef->body, fundef->parms); |
1134 | TREE_TYPE (copy) = fundef->result; | |
3c98ff9b NS |
1135 | } |
1136 | else if (*slot == NULL_TREE) | |
1137 | { | |
1138 | /* We've already used the function itself, so make a copy. */ | |
97f3003f | 1139 | copy = build_tree_list (NULL, NULL); |
43574e4f JJ |
1140 | tree saved_body = DECL_SAVED_TREE (fundef->decl); |
1141 | tree saved_parms = DECL_ARGUMENTS (fundef->decl); | |
1142 | tree saved_result = DECL_RESULT (fundef->decl); | |
1143 | tree saved_fn = current_function_decl; | |
1144 | DECL_SAVED_TREE (fundef->decl) = fundef->body; | |
1145 | DECL_ARGUMENTS (fundef->decl) = fundef->parms; | |
1146 | DECL_RESULT (fundef->decl) = fundef->result; | |
1147 | current_function_decl = fundef->decl; | |
1148 | TREE_PURPOSE (copy) = copy_fn (fundef->decl, TREE_VALUE (copy), | |
1149 | TREE_TYPE (copy)); | |
1150 | current_function_decl = saved_fn; | |
1151 | DECL_RESULT (fundef->decl) = saved_result; | |
1152 | DECL_ARGUMENTS (fundef->decl) = saved_parms; | |
1153 | DECL_SAVED_TREE (fundef->decl) = saved_body; | |
c0daf32d PP |
1154 | } |
1155 | else | |
1156 | { | |
3c98ff9b | 1157 | /* We have a cached function available. */ |
c0daf32d | 1158 | copy = *slot; |
97f3003f | 1159 | *slot = TREE_CHAIN (copy); |
c0daf32d PP |
1160 | } |
1161 | ||
1162 | return copy; | |
1163 | } | |
1164 | ||
3c98ff9b NS |
1165 | /* Save the copy COPY of function FUN for later reuse by |
1166 | get_fundef_copy(). By construction, there will always be an entry | |
1167 | to find. */ | |
c0daf32d PP |
1168 | |
1169 | static void | |
97f3003f | 1170 | save_fundef_copy (tree fun, tree copy) |
c0daf32d | 1171 | { |
3c98ff9b | 1172 | tree *slot = fundef_copies_table->get (fun); |
97f3003f | 1173 | TREE_CHAIN (copy) = *slot; |
c0daf32d PP |
1174 | *slot = copy; |
1175 | } | |
1176 | ||
2d76680f PC |
1177 | /* We have an expression tree T that represents a call, either CALL_EXPR |
1178 | or AGGR_INIT_EXPR. Return the Nth argument. */ | |
1179 | ||
1180 | static inline tree | |
1181 | get_nth_callarg (tree t, int n) | |
1182 | { | |
1183 | switch (TREE_CODE (t)) | |
1184 | { | |
1185 | case CALL_EXPR: | |
1186 | return CALL_EXPR_ARG (t, n); | |
1187 | ||
1188 | case AGGR_INIT_EXPR: | |
1189 | return AGGR_INIT_EXPR_ARG (t, n); | |
1190 | ||
1191 | default: | |
1192 | gcc_unreachable (); | |
1193 | return NULL; | |
1194 | } | |
1195 | } | |
1196 | ||
2d76680f PC |
1197 | /* Attempt to evaluate T which represents a call to a builtin function. |
1198 | We assume here that all builtin functions evaluate to scalar types | |
1199 | represented by _CST nodes. */ | |
1200 | ||
1201 | static tree | |
5756d0f9 | 1202 | cxx_eval_builtin_function_call (const constexpr_ctx *ctx, tree t, tree fun, |
92a596e8 | 1203 | bool lval, |
2d76680f PC |
1204 | bool *non_constant_p, bool *overflow_p) |
1205 | { | |
1206 | const int nargs = call_expr_nargs (t); | |
1207 | tree *args = (tree *) alloca (nargs * sizeof (tree)); | |
1208 | tree new_call; | |
1209 | int i; | |
5756d0f9 JM |
1210 | |
1211 | /* Don't fold __builtin_constant_p within a constexpr function. */ | |
e4082611 | 1212 | bool bi_const_p = DECL_IS_BUILTIN_CONSTANT_P (fun); |
b925d25d | 1213 | |
fe736ffd JM |
1214 | /* If we aren't requiring a constant expression, defer __builtin_constant_p |
1215 | in a constexpr function until we have values for the parameters. */ | |
b925d25d | 1216 | if (bi_const_p |
4cd3e7df | 1217 | && !ctx->manifestly_const_eval |
5756d0f9 JM |
1218 | && current_function_decl |
1219 | && DECL_DECLARED_CONSTEXPR_P (current_function_decl)) | |
2d76680f | 1220 | { |
5756d0f9 JM |
1221 | *non_constant_p = true; |
1222 | return t; | |
2d76680f | 1223 | } |
5756d0f9 | 1224 | |
e4082611 | 1225 | /* For __builtin_is_constant_evaluated, defer it if not |
13de99bc | 1226 | ctx->manifestly_const_eval, otherwise fold it to true. */ |
3d78e008 | 1227 | if (fndecl_built_in_p (fun, CP_BUILT_IN_IS_CONSTANT_EVALUATED, |
13de99bc | 1228 | BUILT_IN_FRONTEND)) |
e4082611 | 1229 | { |
13de99bc | 1230 | if (!ctx->manifestly_const_eval) |
e4082611 JJ |
1231 | { |
1232 | *non_constant_p = true; | |
1233 | return t; | |
1234 | } | |
1235 | return boolean_true_node; | |
1236 | } | |
1237 | ||
5756d0f9 JM |
1238 | /* Be permissive for arguments to built-ins; __builtin_constant_p should |
1239 | return constant false for a non-constant argument. */ | |
1240 | constexpr_ctx new_ctx = *ctx; | |
1241 | new_ctx.quiet = true; | |
5756d0f9 | 1242 | for (i = 0; i < nargs; ++i) |
b925d25d | 1243 | { |
2ff7172a JJ |
1244 | args[i] = CALL_EXPR_ARG (t, i); |
1245 | /* If builtin_valid_in_constant_expr_p is true, | |
1246 | potential_constant_expression_1 has not recursed into the arguments | |
1247 | of the builtin, verify it here. */ | |
1248 | if (!builtin_valid_in_constant_expr_p (fun) | |
1249 | || potential_constant_expression (args[i])) | |
4cd3e7df JJ |
1250 | { |
1251 | bool dummy1 = false, dummy2 = false; | |
1252 | args[i] = cxx_eval_constant_expression (&new_ctx, args[i], false, | |
1253 | &dummy1, &dummy2); | |
1254 | } | |
1255 | ||
b925d25d | 1256 | if (bi_const_p) |
4cd3e7df | 1257 | /* For __builtin_constant_p, fold all expressions with constant values |
b925d25d | 1258 | even if they aren't C++ constant-expressions. */ |
4cd3e7df | 1259 | args[i] = cp_fold_rvalue (args[i]); |
b925d25d | 1260 | } |
5756d0f9 JM |
1261 | |
1262 | bool save_ffbcp = force_folding_builtin_constant_p; | |
b09a67ea | 1263 | force_folding_builtin_constant_p |= ctx->manifestly_const_eval; |
43574e4f JJ |
1264 | tree save_cur_fn = current_function_decl; |
1265 | /* Return name of ctx->call->fundef->decl for __builtin_FUNCTION (). */ | |
1266 | if (fndecl_built_in_p (fun, BUILT_IN_FUNCTION) | |
1267 | && ctx->call | |
1268 | && ctx->call->fundef) | |
1269 | current_function_decl = ctx->call->fundef->decl; | |
109d2197 JJ |
1270 | new_call = fold_builtin_call_array (EXPR_LOCATION (t), TREE_TYPE (t), |
1271 | CALL_EXPR_FN (t), nargs, args); | |
43574e4f | 1272 | current_function_decl = save_cur_fn; |
5756d0f9 | 1273 | force_folding_builtin_constant_p = save_ffbcp; |
109d2197 JJ |
1274 | if (new_call == NULL) |
1275 | { | |
1276 | if (!*non_constant_p && !ctx->quiet) | |
1277 | { | |
1b6fa695 ML |
1278 | /* Do not allow__builtin_unreachable in constexpr function. |
1279 | The __builtin_unreachable call with BUILTINS_LOCATION | |
1280 | comes from cp_maybe_instrument_return. */ | |
3d78e008 | 1281 | if (fndecl_built_in_p (fun, BUILT_IN_UNREACHABLE) |
1b6fa695 | 1282 | && EXPR_LOCATION (t) == BUILTINS_LOCATION) |
84fa214d | 1283 | error ("%<constexpr%> call flows off the end of the function"); |
1b6fa695 ML |
1284 | else |
1285 | { | |
1286 | new_call = build_call_array_loc (EXPR_LOCATION (t), TREE_TYPE (t), | |
1287 | CALL_EXPR_FN (t), nargs, args); | |
1288 | error ("%q+E is not a constant expression", new_call); | |
1289 | } | |
109d2197 JJ |
1290 | } |
1291 | *non_constant_p = true; | |
1292 | return t; | |
1293 | } | |
1294 | ||
43574e4f | 1295 | if (!potential_constant_expression (new_call)) |
109d2197 JJ |
1296 | { |
1297 | if (!*non_constant_p && !ctx->quiet) | |
1298 | error ("%q+E is not a constant expression", new_call); | |
1299 | *non_constant_p = true; | |
1300 | return t; | |
1301 | } | |
1302 | ||
1303 | return cxx_eval_constant_expression (&new_ctx, new_call, lval, | |
1304 | non_constant_p, overflow_p); | |
2d76680f PC |
1305 | } |
1306 | ||
1307 | /* TEMP is the constant value of a temporary object of type TYPE. Adjust | |
1308 | the type of the value to match. */ | |
1309 | ||
1310 | static tree | |
1311 | adjust_temp_type (tree type, tree temp) | |
1312 | { | |
47be9509 | 1313 | if (same_type_p (TREE_TYPE (temp), type)) |
2d76680f PC |
1314 | return temp; |
1315 | /* Avoid wrapping an aggregate value in a NOP_EXPR. */ | |
1316 | if (TREE_CODE (temp) == CONSTRUCTOR) | |
b27f74e7 MP |
1317 | { |
1318 | /* build_constructor wouldn't retain various CONSTRUCTOR flags. */ | |
1319 | tree t = copy_node (temp); | |
1320 | TREE_TYPE (t) = type; | |
1321 | return t; | |
1322 | } | |
ff8ba86f JJ |
1323 | if (TREE_CODE (temp) == EMPTY_CLASS_EXPR) |
1324 | return build0 (EMPTY_CLASS_EXPR, type); | |
2d76680f | 1325 | gcc_assert (scalarish_type_p (type)); |
72b091f7 MP |
1326 | /* Now we know we're dealing with a scalar, and a prvalue of non-class |
1327 | type is cv-unqualified. */ | |
1328 | return cp_fold_convert (cv_unqualified (type), temp); | |
2d76680f PC |
1329 | } |
1330 | ||
9b9eb42a JM |
1331 | /* If T is a CONSTRUCTOR, return an unshared copy of T and any |
1332 | sub-CONSTRUCTORs. Otherwise return T. | |
0146e25f | 1333 | |
9b9eb42a JM |
1334 | We use this whenever we initialize an object as a whole, whether it's a |
1335 | parameter, a local variable, or a subobject, so that subsequent | |
1336 | modifications don't affect other places where it was used. */ | |
0146e25f | 1337 | |
1f6857ba | 1338 | tree |
3da7d774 | 1339 | unshare_constructor (tree t MEM_STAT_DECL) |
0146e25f | 1340 | { |
9b9eb42a JM |
1341 | if (!t || TREE_CODE (t) != CONSTRUCTOR) |
1342 | return t; | |
1343 | auto_vec <tree*, 4> ptrs; | |
1344 | ptrs.safe_push (&t); | |
1345 | while (!ptrs.is_empty ()) | |
1346 | { | |
1347 | tree *p = ptrs.pop (); | |
3da7d774 JM |
1348 | tree n = copy_node (*p PASS_MEM_STAT); |
1349 | CONSTRUCTOR_ELTS (n) = vec_safe_copy (CONSTRUCTOR_ELTS (*p) PASS_MEM_STAT); | |
9b9eb42a JM |
1350 | *p = n; |
1351 | vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (n); | |
1352 | constructor_elt *ce; | |
1353 | for (HOST_WIDE_INT i = 0; vec_safe_iterate (v, i, &ce); ++i) | |
1354 | if (TREE_CODE (ce->value) == CONSTRUCTOR) | |
1355 | ptrs.safe_push (&ce->value); | |
1356 | } | |
0146e25f PP |
1357 | return t; |
1358 | } | |
1359 | ||
620adbec JM |
1360 | /* If T is a CONSTRUCTOR, ggc_free T and any sub-CONSTRUCTORs. */ |
1361 | ||
1362 | static void | |
1363 | free_constructor (tree t) | |
1364 | { | |
1365 | if (!t || TREE_CODE (t) != CONSTRUCTOR) | |
1366 | return; | |
1367 | releasing_vec ctors; | |
1368 | vec_safe_push (ctors, t); | |
1369 | while (!ctors->is_empty ()) | |
1370 | { | |
1371 | tree c = ctors->pop (); | |
1372 | if (vec<constructor_elt, va_gc> *elts = CONSTRUCTOR_ELTS (c)) | |
1373 | { | |
1374 | constructor_elt *ce; | |
1375 | for (HOST_WIDE_INT i = 0; vec_safe_iterate (elts, i, &ce); ++i) | |
1376 | if (TREE_CODE (ce->value) == CONSTRUCTOR) | |
1377 | vec_safe_push (ctors, ce->value); | |
1378 | ggc_free (elts); | |
1379 | } | |
1380 | ggc_free (c); | |
1381 | } | |
1382 | } | |
1383 | ||
2d76680f PC |
1384 | /* Subroutine of cxx_eval_call_expression. |
1385 | We are processing a call expression (either CALL_EXPR or | |
3e605b20 | 1386 | AGGR_INIT_EXPR) in the context of CTX. Evaluate |
2d76680f PC |
1387 | all arguments and bind their values to correspondings |
1388 | parameters, making up the NEW_CALL context. */ | |
1389 | ||
1390 | static void | |
3e605b20 | 1391 | cxx_bind_parameters_in_call (const constexpr_ctx *ctx, tree t, |
2d76680f | 1392 | constexpr_call *new_call, |
12d9ce19 JM |
1393 | bool *non_constant_p, bool *overflow_p, |
1394 | bool *non_constant_args) | |
2d76680f PC |
1395 | { |
1396 | const int nargs = call_expr_nargs (t); | |
1397 | tree fun = new_call->fundef->decl; | |
43574e4f | 1398 | tree parms = new_call->fundef->parms; |
2d76680f | 1399 | int i; |
3c961dc7 JM |
1400 | /* We don't record ellipsis args below. */ |
1401 | int nparms = list_length (parms); | |
1402 | int nbinds = nargs < nparms ? nargs : nparms; | |
1403 | tree binds = new_call->bindings = make_tree_vec (nbinds); | |
2d76680f PC |
1404 | for (i = 0; i < nargs; ++i) |
1405 | { | |
1406 | tree x, arg; | |
1407 | tree type = parms ? TREE_TYPE (parms) : void_type_node; | |
2d76680f | 1408 | x = get_nth_callarg (t, i); |
3e605b20 JM |
1409 | /* For member function, the first argument is a pointer to the implied |
1410 | object. For a constructor, it might still be a dummy object, in | |
60813a46 | 1411 | which case we get the real argument from ctx. */ |
3e605b20 JM |
1412 | if (i == 0 && DECL_CONSTRUCTOR_P (fun) |
1413 | && is_dummy_object (x)) | |
1414 | { | |
1415 | x = ctx->object; | |
84dd815f | 1416 | x = build_address (x); |
3e605b20 | 1417 | } |
43574e4f JJ |
1418 | if (TREE_ADDRESSABLE (type)) |
1419 | /* Undo convert_for_arg_passing work here. */ | |
1420 | x = convert_from_reference (x); | |
0e038601 | 1421 | arg = cxx_eval_constant_expression (ctx, x, /*lval=*/false, |
5a804683 | 1422 | non_constant_p, overflow_p); |
2d76680f | 1423 | /* Don't VERIFY_CONSTANT here. */ |
2b3ab879 | 1424 | if (*non_constant_p && ctx->quiet) |
2d76680f PC |
1425 | return; |
1426 | /* Just discard ellipsis args after checking their constantitude. */ | |
1427 | if (!parms) | |
1428 | continue; | |
4727d4c6 NS |
1429 | |
1430 | if (!*non_constant_p) | |
1431 | { | |
620adbec JM |
1432 | /* Unsharing here isn't necessary for correctness, but it |
1433 | significantly improves memory performance for some reason. */ | |
1dc23505 | 1434 | arg = unshare_constructor (arg); |
4727d4c6 NS |
1435 | /* Make sure the binding has the same type as the parm. But |
1436 | only for constant args. */ | |
9f613f06 | 1437 | if (!TYPE_REF_P (type)) |
4727d4c6 NS |
1438 | arg = adjust_temp_type (type, arg); |
1439 | if (!TREE_CONSTANT (arg)) | |
1440 | *non_constant_args = true; | |
3c961dc7 | 1441 | TREE_VEC_ELT (binds, i) = arg; |
4727d4c6 | 1442 | } |
2d76680f PC |
1443 | parms = TREE_CHAIN (parms); |
1444 | } | |
1445 | } | |
1446 | ||
1447 | /* Variables and functions to manage constexpr call expansion context. | |
1448 | These do not need to be marked for PCH or GC. */ | |
1449 | ||
1450 | /* FIXME remember and print actual constant arguments. */ | |
7de76362 | 1451 | static vec<tree> call_stack; |
2d76680f PC |
1452 | static int call_stack_tick; |
1453 | static int last_cx_error_tick; | |
1454 | ||
7ffc7de5 | 1455 | static int |
2d76680f PC |
1456 | push_cx_call_context (tree call) |
1457 | { | |
1458 | ++call_stack_tick; | |
1459 | if (!EXPR_HAS_LOCATION (call)) | |
1460 | SET_EXPR_LOCATION (call, input_location); | |
1461 | call_stack.safe_push (call); | |
7ffc7de5 JM |
1462 | int len = call_stack.length (); |
1463 | if (len > max_constexpr_depth) | |
2d76680f | 1464 | return false; |
7ffc7de5 | 1465 | return len; |
2d76680f PC |
1466 | } |
1467 | ||
1468 | static void | |
1469 | pop_cx_call_context (void) | |
1470 | { | |
1471 | ++call_stack_tick; | |
1472 | call_stack.pop (); | |
1473 | } | |
1474 | ||
1475 | vec<tree> | |
1476 | cx_error_context (void) | |
1477 | { | |
1478 | vec<tree> r = vNULL; | |
1479 | if (call_stack_tick != last_cx_error_tick | |
1480 | && !call_stack.is_empty ()) | |
1481 | r = call_stack; | |
1482 | last_cx_error_tick = call_stack_tick; | |
1483 | return r; | |
1484 | } | |
1485 | ||
44a845ca MS |
1486 | /* Evaluate a call T to a GCC internal function when possible and return |
1487 | the evaluated result or, under the control of CTX, give an error, set | |
1488 | NON_CONSTANT_P, and return the unevaluated call T otherwise. */ | |
1489 | ||
1490 | static tree | |
1491 | cxx_eval_internal_function (const constexpr_ctx *ctx, tree t, | |
1492 | bool lval, | |
1493 | bool *non_constant_p, bool *overflow_p) | |
1494 | { | |
1495 | enum tree_code opcode = ERROR_MARK; | |
1496 | ||
1497 | switch (CALL_EXPR_IFN (t)) | |
1498 | { | |
1499 | case IFN_UBSAN_NULL: | |
1500 | case IFN_UBSAN_BOUNDS: | |
1501 | case IFN_UBSAN_VPTR: | |
81fea426 | 1502 | case IFN_FALLTHROUGH: |
44a845ca MS |
1503 | return void_node; |
1504 | ||
1505 | case IFN_ADD_OVERFLOW: | |
1506 | opcode = PLUS_EXPR; | |
1507 | break; | |
1508 | case IFN_SUB_OVERFLOW: | |
1509 | opcode = MINUS_EXPR; | |
1510 | break; | |
1511 | case IFN_MUL_OVERFLOW: | |
1512 | opcode = MULT_EXPR; | |
1513 | break; | |
1514 | ||
e16f1cc7 JJ |
1515 | case IFN_LAUNDER: |
1516 | return cxx_eval_constant_expression (ctx, CALL_EXPR_ARG (t, 0), | |
1517 | false, non_constant_p, overflow_p); | |
1518 | ||
d8fcab68 JJ |
1519 | case IFN_VEC_CONVERT: |
1520 | { | |
1521 | tree arg = cxx_eval_constant_expression (ctx, CALL_EXPR_ARG (t, 0), | |
1522 | false, non_constant_p, | |
1523 | overflow_p); | |
1524 | if (TREE_CODE (arg) == VECTOR_CST) | |
1525 | return fold_const_call (CFN_VEC_CONVERT, TREE_TYPE (t), arg); | |
1526 | else | |
1527 | { | |
1528 | *non_constant_p = true; | |
1529 | return t; | |
1530 | } | |
1531 | } | |
1532 | ||
44a845ca MS |
1533 | default: |
1534 | if (!ctx->quiet) | |
f9d0ca40 | 1535 | error_at (cp_expr_loc_or_input_loc (t), |
44a845ca MS |
1536 | "call to internal function %qE", t); |
1537 | *non_constant_p = true; | |
1538 | return t; | |
1539 | } | |
1540 | ||
1541 | /* Evaluate constant arguments using OPCODE and return a complex | |
1542 | number containing the result and the overflow bit. */ | |
1543 | tree arg0 = cxx_eval_constant_expression (ctx, CALL_EXPR_ARG (t, 0), lval, | |
1544 | non_constant_p, overflow_p); | |
1545 | tree arg1 = cxx_eval_constant_expression (ctx, CALL_EXPR_ARG (t, 1), lval, | |
1546 | non_constant_p, overflow_p); | |
1547 | ||
1548 | if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST) | |
1549 | { | |
f9d0ca40 | 1550 | location_t loc = cp_expr_loc_or_input_loc (t); |
44a845ca MS |
1551 | tree type = TREE_TYPE (TREE_TYPE (t)); |
1552 | tree result = fold_binary_loc (loc, opcode, type, | |
1553 | fold_convert_loc (loc, type, arg0), | |
1554 | fold_convert_loc (loc, type, arg1)); | |
1555 | tree ovf | |
1556 | = build_int_cst (type, arith_overflowed_p (opcode, type, arg0, arg1)); | |
1557 | /* Reset TREE_OVERFLOW to avoid warnings for the overflow. */ | |
1558 | if (TREE_OVERFLOW (result)) | |
1559 | TREE_OVERFLOW (result) = 0; | |
1560 | ||
1561 | return build_complex (TREE_TYPE (t), result, ovf); | |
1562 | } | |
1563 | ||
1564 | *non_constant_p = true; | |
1565 | return t; | |
1566 | } | |
1567 | ||
e8c48716 | 1568 | /* Clean CONSTRUCTOR_NO_CLEARING from CTOR and its sub-aggregates. */ |
ecc57615 JM |
1569 | |
1570 | static void | |
1571 | clear_no_implicit_zero (tree ctor) | |
1572 | { | |
e8c48716 | 1573 | if (CONSTRUCTOR_NO_CLEARING (ctor)) |
ecc57615 | 1574 | { |
e8c48716 | 1575 | CONSTRUCTOR_NO_CLEARING (ctor) = false; |
ecc57615 JM |
1576 | tree elt; unsigned HOST_WIDE_INT idx; |
1577 | FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), idx, elt) | |
1578 | if (TREE_CODE (elt) == CONSTRUCTOR) | |
1579 | clear_no_implicit_zero (elt); | |
1580 | } | |
1581 | } | |
1582 | ||
04e1749c MP |
1583 | /* Complain about a const object OBJ being modified in a constant expression. |
1584 | EXPR is the MODIFY_EXPR expression performing the modification. */ | |
1585 | ||
1586 | static void | |
1587 | modifying_const_object_error (tree expr, tree obj) | |
1588 | { | |
1589 | location_t loc = cp_expr_loc_or_input_loc (expr); | |
1590 | auto_diagnostic_group d; | |
1591 | error_at (loc, "modifying a const object %qE is not allowed in " | |
1592 | "a constant expression", TREE_OPERAND (expr, 0)); | |
1593 | inform (location_of (obj), "originally declared %<const%> here"); | |
1594 | } | |
1595 | ||
8e007055 JJ |
1596 | /* Return true if FNDECL is a replaceable global allocation function that |
1597 | should be useable during constant expression evaluation. */ | |
1598 | ||
1599 | static inline bool | |
1600 | cxx_replaceable_global_alloc_fn (tree fndecl) | |
1601 | { | |
1602 | return (cxx_dialect >= cxx2a | |
1603 | && IDENTIFIER_NEWDEL_OP_P (DECL_NAME (fndecl)) | |
1604 | && CP_DECL_CONTEXT (fndecl) == global_namespace); | |
1605 | } | |
1606 | ||
2d76680f PC |
1607 | /* Subroutine of cxx_eval_constant_expression. |
1608 | Evaluate the call expression tree T in the context of OLD_CALL expression | |
1609 | evaluation. */ | |
1610 | ||
1611 | static tree | |
3e605b20 | 1612 | cxx_eval_call_expression (const constexpr_ctx *ctx, tree t, |
92a596e8 | 1613 | bool lval, |
2d76680f PC |
1614 | bool *non_constant_p, bool *overflow_p) |
1615 | { | |
f9d0ca40 | 1616 | location_t loc = cp_expr_loc_or_input_loc (t); |
2d76680f | 1617 | tree fun = get_function_named_in_call (t); |
cce3ae91 | 1618 | constexpr_call new_call |
13de99bc | 1619 | = { NULL, NULL, NULL, 0, ctx->manifestly_const_eval }; |
7ffc7de5 | 1620 | int depth_ok; |
2d76680f | 1621 | |
0b274c17 | 1622 | if (fun == NULL_TREE) |
44a845ca MS |
1623 | return cxx_eval_internal_function (ctx, t, lval, |
1624 | non_constant_p, overflow_p); | |
0b274c17 | 1625 | |
2d76680f PC |
1626 | if (TREE_CODE (fun) != FUNCTION_DECL) |
1627 | { | |
1628 | /* Might be a constexpr function pointer. */ | |
2b3ab879 | 1629 | fun = cxx_eval_constant_expression (ctx, fun, |
92a596e8 | 1630 | /*lval*/false, non_constant_p, |
5a804683 | 1631 | overflow_p); |
2d76680f PC |
1632 | STRIP_NOPS (fun); |
1633 | if (TREE_CODE (fun) == ADDR_EXPR) | |
1634 | fun = TREE_OPERAND (fun, 0); | |
582d2481 JJ |
1635 | /* For TARGET_VTABLE_USES_DESCRIPTORS targets, there is no |
1636 | indirection, the called expression is a pointer into the | |
1637 | virtual table which should contain FDESC_EXPR. Extract the | |
1638 | FUNCTION_DECL from there. */ | |
1639 | else if (TARGET_VTABLE_USES_DESCRIPTORS | |
1640 | && TREE_CODE (fun) == POINTER_PLUS_EXPR | |
1641 | && TREE_CODE (TREE_OPERAND (fun, 0)) == ADDR_EXPR | |
1642 | && TREE_CODE (TREE_OPERAND (fun, 1)) == INTEGER_CST) | |
1643 | { | |
1644 | tree d = TREE_OPERAND (TREE_OPERAND (fun, 0), 0); | |
1645 | if (VAR_P (d) | |
1646 | && DECL_VTABLE_OR_VTT_P (d) | |
1647 | && TREE_CODE (TREE_TYPE (d)) == ARRAY_TYPE | |
1648 | && TREE_TYPE (TREE_TYPE (d)) == vtable_entry_type | |
1649 | && DECL_INITIAL (d) | |
1650 | && TREE_CODE (DECL_INITIAL (d)) == CONSTRUCTOR) | |
1651 | { | |
1652 | tree i = int_const_binop (TRUNC_DIV_EXPR, TREE_OPERAND (fun, 1), | |
1653 | TYPE_SIZE_UNIT (vtable_entry_type)); | |
1654 | HOST_WIDE_INT idx = find_array_ctor_elt (DECL_INITIAL (d), i); | |
1655 | if (idx >= 0) | |
1656 | { | |
1657 | tree fdesc | |
1658 | = (*CONSTRUCTOR_ELTS (DECL_INITIAL (d)))[idx].value; | |
1659 | if (TREE_CODE (fdesc) == FDESC_EXPR | |
1660 | && integer_zerop (TREE_OPERAND (fdesc, 1))) | |
1661 | fun = TREE_OPERAND (fdesc, 0); | |
1662 | } | |
1663 | } | |
1664 | } | |
2d76680f PC |
1665 | } |
1666 | if (TREE_CODE (fun) != FUNCTION_DECL) | |
1667 | { | |
2b3ab879 | 1668 | if (!ctx->quiet && !*non_constant_p) |
84fa214d | 1669 | error_at (loc, "expression %qE does not designate a %<constexpr%> " |
2d76680f PC |
1670 | "function", fun); |
1671 | *non_constant_p = true; | |
1672 | return t; | |
1673 | } | |
1674 | if (DECL_CLONED_FUNCTION_P (fun)) | |
1675 | fun = DECL_CLONED_FUNCTION (fun); | |
0b274c17 MP |
1676 | |
1677 | if (is_ubsan_builtin_p (fun)) | |
1678 | return void_node; | |
1679 | ||
3d78e008 | 1680 | if (fndecl_built_in_p (fun)) |
5756d0f9 | 1681 | return cxx_eval_builtin_function_call (ctx, t, fun, |
92a596e8 | 1682 | lval, non_constant_p, overflow_p); |
2d76680f PC |
1683 | if (!DECL_DECLARED_CONSTEXPR_P (fun)) |
1684 | { | |
8e007055 JJ |
1685 | if (cxx_replaceable_global_alloc_fn (fun)) |
1686 | { | |
1687 | const int nargs = call_expr_nargs (t); | |
1688 | tree arg0 = NULL_TREE; | |
1689 | for (int i = 0; i < nargs; ++i) | |
1690 | { | |
1691 | tree arg = CALL_EXPR_ARG (t, i); | |
1692 | arg = cxx_eval_constant_expression (ctx, arg, false, | |
1693 | non_constant_p, overflow_p); | |
1694 | VERIFY_CONSTANT (arg); | |
1695 | if (i == 0) | |
1696 | arg0 = arg; | |
1697 | } | |
1698 | gcc_assert (arg0); | |
1699 | if (IDENTIFIER_NEW_OP_P (DECL_NAME (fun))) | |
1700 | { | |
1701 | tree type = build_array_type_nelts (char_type_node, | |
1702 | tree_to_uhwi (arg0)); | |
1703 | tree var = build_decl (loc, VAR_DECL, heap_uninit_identifier, | |
1704 | type); | |
1705 | DECL_ARTIFICIAL (var) = 1; | |
1706 | TREE_STATIC (var) = 1; | |
1707 | ctx->global->heap_vars.safe_push (var); | |
1708 | ctx->global->values.put (var, NULL_TREE); | |
1709 | return fold_convert (ptr_type_node, build_address (var)); | |
1710 | } | |
1711 | else | |
1712 | { | |
1713 | STRIP_NOPS (arg0); | |
1714 | if (TREE_CODE (arg0) == ADDR_EXPR | |
1715 | && VAR_P (TREE_OPERAND (arg0, 0))) | |
1716 | { | |
1717 | tree var = TREE_OPERAND (arg0, 0); | |
1718 | if (DECL_NAME (var) == heap_uninit_identifier | |
1719 | || DECL_NAME (var) == heap_identifier) | |
1720 | { | |
1721 | DECL_NAME (var) = heap_deleted_identifier; | |
1722 | ctx->global->values.remove (var); | |
1723 | return void_node; | |
1724 | } | |
1725 | else if (DECL_NAME (var) == heap_deleted_identifier) | |
1726 | { | |
1727 | if (!ctx->quiet) | |
1728 | error_at (loc, "deallocation of already deallocated " | |
1729 | "storage"); | |
1730 | *non_constant_p = true; | |
1731 | return t; | |
1732 | } | |
1733 | } | |
1734 | if (!ctx->quiet) | |
1735 | error_at (loc, "deallocation of storage that was " | |
1736 | "not previously allocated"); | |
1737 | *non_constant_p = true; | |
1738 | return t; | |
1739 | } | |
1740 | } | |
2b3ab879 | 1741 | if (!ctx->quiet) |
2d76680f | 1742 | { |
11399477 | 1743 | if (!lambda_static_thunk_p (fun)) |
84fa214d | 1744 | error_at (loc, "call to non-%<constexpr%> function %qD", fun); |
2d76680f PC |
1745 | explain_invalid_constexpr_fn (fun); |
1746 | } | |
1747 | *non_constant_p = true; | |
1748 | return t; | |
1749 | } | |
1750 | ||
86461cad JM |
1751 | constexpr_ctx new_ctx = *ctx; |
1752 | if (DECL_CONSTRUCTOR_P (fun) && !ctx->object | |
1753 | && TREE_CODE (t) == AGGR_INIT_EXPR) | |
1754 | { | |
1755 | /* We want to have an initialization target for an AGGR_INIT_EXPR. | |
1756 | If we don't already have one in CTX, use the AGGR_INIT_EXPR_SLOT. */ | |
1757 | new_ctx.object = AGGR_INIT_EXPR_SLOT (t); | |
1758 | tree ctor = new_ctx.ctor = build_constructor (DECL_CONTEXT (fun), NULL); | |
e8c48716 | 1759 | CONSTRUCTOR_NO_CLEARING (ctor) = true; |
8e007055 | 1760 | ctx->global->values.put (new_ctx.object, ctor); |
86461cad JM |
1761 | ctx = &new_ctx; |
1762 | } | |
1763 | ||
2d76680f PC |
1764 | /* Shortcut trivial constructor/op=. */ |
1765 | if (trivial_fn_p (fun)) | |
1766 | { | |
86461cad | 1767 | tree init = NULL_TREE; |
2d76680f | 1768 | if (call_expr_nargs (t) == 2) |
86461cad | 1769 | init = convert_from_reference (get_nth_callarg (t, 1)); |
2d76680f PC |
1770 | else if (TREE_CODE (t) == AGGR_INIT_EXPR |
1771 | && AGGR_INIT_ZERO_FIRST (t)) | |
86461cad JM |
1772 | init = build_zero_init (DECL_CONTEXT (fun), NULL_TREE, false); |
1773 | if (init) | |
1774 | { | |
1775 | tree op = get_nth_callarg (t, 0); | |
1776 | if (is_dummy_object (op)) | |
1777 | op = ctx->object; | |
1778 | else | |
1779 | op = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (op)), op); | |
1780 | tree set = build2 (MODIFY_EXPR, TREE_TYPE (op), op, init); | |
c8816908 JM |
1781 | new_ctx.call = &new_call; |
1782 | return cxx_eval_constant_expression (&new_ctx, set, lval, | |
86461cad JM |
1783 | non_constant_p, overflow_p); |
1784 | } | |
2d76680f PC |
1785 | } |
1786 | ||
81371eff JM |
1787 | /* We can't defer instantiating the function any longer. */ |
1788 | if (!DECL_INITIAL (fun) | |
1789 | && DECL_TEMPLOID_INSTANTIATION (fun)) | |
1790 | { | |
f065303f JM |
1791 | location_t save_loc = input_location; |
1792 | input_location = loc; | |
81371eff JM |
1793 | ++function_depth; |
1794 | instantiate_decl (fun, /*defer_ok*/false, /*expl_inst*/false); | |
1795 | --function_depth; | |
f065303f | 1796 | input_location = save_loc; |
81371eff JM |
1797 | } |
1798 | ||
2d76680f | 1799 | /* If in direct recursive call, optimize definition search. */ |
c8816908 | 1800 | if (ctx && ctx->call && ctx->call->fundef && ctx->call->fundef->decl == fun) |
3e605b20 | 1801 | new_call.fundef = ctx->call->fundef; |
2d76680f PC |
1802 | else |
1803 | { | |
1804 | new_call.fundef = retrieve_constexpr_fundef (fun); | |
4ddcdbf9 JM |
1805 | if (new_call.fundef == NULL || new_call.fundef->body == NULL |
1806 | || fun == current_function_decl) | |
2d76680f | 1807 | { |
2b3ab879 | 1808 | if (!ctx->quiet) |
2d76680f | 1809 | { |
4ddcdbf9 JM |
1810 | /* We need to check for current_function_decl here in case we're |
1811 | being called during cp_fold_function, because at that point | |
1812 | DECL_INITIAL is set properly and we have a fundef but we | |
1813 | haven't lowered invisirefs yet (c++/70344). */ | |
1814 | if (DECL_INITIAL (fun) == error_mark_node | |
1815 | || fun == current_function_decl) | |
ddd6d421 JM |
1816 | error_at (loc, "%qD called in a constant expression before its " |
1817 | "definition is complete", fun); | |
1818 | else if (DECL_INITIAL (fun)) | |
2d76680f | 1819 | { |
98e5a19a JM |
1820 | /* The definition of fun was somehow unsuitable. But pretend |
1821 | that lambda static thunks don't exist. */ | |
1822 | if (!lambda_static_thunk_p (fun)) | |
1823 | error_at (loc, "%qD called in a constant expression", fun); | |
2d76680f PC |
1824 | explain_invalid_constexpr_fn (fun); |
1825 | } | |
1826 | else | |
1827 | error_at (loc, "%qD used before its definition", fun); | |
1828 | } | |
1829 | *non_constant_p = true; | |
1830 | return t; | |
1831 | } | |
1832 | } | |
60813a46 | 1833 | |
12d9ce19 | 1834 | bool non_constant_args = false; |
3e605b20 | 1835 | cxx_bind_parameters_in_call (ctx, t, &new_call, |
12d9ce19 | 1836 | non_constant_p, overflow_p, &non_constant_args); |
ecdcd560 JM |
1837 | |
1838 | /* We build up the bindings list before we know whether we already have this | |
1839 | call cached. If we don't end up saving these bindings, ggc_free them when | |
1840 | this function exits. */ | |
6c1dae73 | 1841 | class free_bindings |
ecdcd560 | 1842 | { |
6c1dae73 | 1843 | public: |
ecdcd560 JM |
1844 | tree &bindings; |
1845 | bool do_free; | |
1846 | free_bindings (tree &b): bindings (b), do_free(true) { } | |
1847 | void preserve () { do_free = false; } | |
1848 | ~free_bindings () { | |
1849 | if (do_free) | |
620adbec JM |
1850 | { |
1851 | for (int i = 0; i < TREE_VEC_LENGTH (bindings); ++i) | |
1852 | free_constructor (TREE_VEC_ELT (bindings, i)); | |
1853 | ggc_free (bindings); | |
1854 | } | |
ecdcd560 JM |
1855 | } |
1856 | } fb (new_call.bindings); | |
1857 | ||
2d76680f PC |
1858 | if (*non_constant_p) |
1859 | return t; | |
1860 | ||
1861 | depth_ok = push_cx_call_context (t); | |
1862 | ||
04e1749c MP |
1863 | /* Remember the object we are constructing. */ |
1864 | tree new_obj = NULL_TREE; | |
1865 | if (DECL_CONSTRUCTOR_P (fun)) | |
1866 | { | |
1867 | /* In a constructor, it should be the first `this' argument. | |
1868 | At this point it has already been evaluated in the call | |
1869 | to cxx_bind_parameters_in_call. */ | |
1870 | new_obj = TREE_VEC_ELT (new_call.bindings, 0); | |
1871 | STRIP_NOPS (new_obj); | |
1872 | if (TREE_CODE (new_obj) == ADDR_EXPR) | |
1873 | new_obj = TREE_OPERAND (new_obj, 0); | |
1874 | } | |
1875 | ||
12d9ce19 | 1876 | tree result = NULL_TREE; |
2d76680f | 1877 | |
12d9ce19 | 1878 | constexpr_call *entry = NULL; |
4a58d2fe | 1879 | if (depth_ok && !non_constant_args && ctx->strict) |
2d76680f | 1880 | { |
cce3ae91 JJ |
1881 | new_call.hash = constexpr_fundef_hasher::hash (new_call.fundef); |
1882 | new_call.hash | |
1883 | = iterative_hash_template_arg (new_call.bindings, new_call.hash); | |
1884 | new_call.hash | |
13de99bc | 1885 | = iterative_hash_object (ctx->manifestly_const_eval, new_call.hash); |
12d9ce19 JM |
1886 | |
1887 | /* If we have seen this call before, we are done. */ | |
1888 | maybe_initialize_constexpr_call_table (); | |
1889 | constexpr_call **slot | |
1890 | = constexpr_call_table->find_slot (&new_call, INSERT); | |
1891 | entry = *slot; | |
1892 | if (entry == NULL) | |
1893 | { | |
7ffc7de5 JM |
1894 | /* Only cache up to constexpr_cache_depth to limit memory use. */ |
1895 | if (depth_ok < constexpr_cache_depth) | |
1896 | { | |
1897 | /* We need to keep a pointer to the entry, not just the slot, as | |
1898 | the slot can move during evaluation of the body. */ | |
1899 | *slot = entry = ggc_alloc<constexpr_call> (); | |
1900 | *entry = new_call; | |
1901 | fb.preserve (); | |
1902 | } | |
12d9ce19 | 1903 | } |
7ffc7de5 JM |
1904 | /* Calls that are in progress have their result set to NULL, so that we |
1905 | can detect circular dependencies. Now that we only cache up to | |
1906 | constexpr_cache_depth this won't catch circular dependencies that | |
1907 | start deeper, but they'll hit the recursion or ops limit. */ | |
12d9ce19 JM |
1908 | else if (entry->result == NULL) |
1909 | { | |
1910 | if (!ctx->quiet) | |
1911 | error ("call has circular dependency"); | |
1912 | *non_constant_p = true; | |
1913 | entry->result = result = error_mark_node; | |
1914 | } | |
1915 | else | |
1916 | result = entry->result; | |
2d76680f PC |
1917 | } |
1918 | ||
1919 | if (!depth_ok) | |
1920 | { | |
2b3ab879 | 1921 | if (!ctx->quiet) |
84fa214d | 1922 | error ("%<constexpr%> evaluation depth exceeds maximum of %d (use " |
7e7a6ed7 | 1923 | "%<-fconstexpr-depth=%> to increase the maximum)", |
2d76680f PC |
1924 | max_constexpr_depth); |
1925 | *non_constant_p = true; | |
12d9ce19 | 1926 | result = error_mark_node; |
2d76680f PC |
1927 | } |
1928 | else | |
1929 | { | |
de54de93 JM |
1930 | if (result && result != error_mark_node) |
1931 | /* OK */; | |
1932 | else if (!DECL_SAVED_TREE (fun)) | |
1933 | { | |
1934 | /* When at_eof >= 2, cgraph has started throwing away | |
1935 | DECL_SAVED_TREE, so fail quietly. FIXME we get here because of | |
1936 | late code generation for VEC_INIT_EXPR, which needs to be | |
1937 | completely reconsidered. */ | |
1938 | gcc_assert (at_eof >= 2 && ctx->quiet); | |
1939 | *non_constant_p = true; | |
1940 | } | |
1941 | else | |
3e605b20 | 1942 | { |
c0daf32d | 1943 | tree body, parms, res; |
620adbec | 1944 | releasing_vec ctors; |
0567dcd2 | 1945 | |
c0daf32d | 1946 | /* Reuse or create a new unshared copy of this function's body. */ |
43574e4f | 1947 | tree copy = get_fundef_copy (new_call.fundef); |
97f3003f JM |
1948 | body = TREE_PURPOSE (copy); |
1949 | parms = TREE_VALUE (copy); | |
1950 | res = TREE_TYPE (copy); | |
0567dcd2 MP |
1951 | |
1952 | /* Associate the bindings with the remapped parms. */ | |
1953 | tree bound = new_call.bindings; | |
1954 | tree remapped = parms; | |
3c961dc7 | 1955 | for (int i = 0; i < TREE_VEC_LENGTH (bound); ++i) |
60813a46 | 1956 | { |
3c961dc7 | 1957 | tree arg = TREE_VEC_ELT (bound, i); |
7f0e23e9 | 1958 | /* Don't share a CONSTRUCTOR that might be changed. */ |
0146e25f | 1959 | arg = unshare_constructor (arg); |
620adbec JM |
1960 | if (TREE_CODE (arg) == CONSTRUCTOR) |
1961 | vec_safe_push (ctors, arg); | |
8e007055 | 1962 | ctx->global->values.put (remapped, arg); |
0567dcd2 | 1963 | remapped = DECL_CHAIN (remapped); |
60813a46 | 1964 | } |
0567dcd2 MP |
1965 | /* Add the RESULT_DECL to the values map, too. */ |
1966 | tree slot = NULL_TREE; | |
1967 | if (DECL_BY_REFERENCE (res)) | |
60813a46 | 1968 | { |
0567dcd2 MP |
1969 | slot = AGGR_INIT_EXPR_SLOT (t); |
1970 | tree addr = build_address (slot); | |
1971 | addr = build_nop (TREE_TYPE (res), addr); | |
8e007055 JJ |
1972 | ctx->global->values.put (res, addr); |
1973 | ctx->global->values.put (slot, NULL_TREE); | |
0567dcd2 MP |
1974 | } |
1975 | else | |
8e007055 | 1976 | ctx->global->values.put (res, NULL_TREE); |
60813a46 | 1977 | |
c0daf32d PP |
1978 | /* Track the callee's evaluated SAVE_EXPRs so that we can forget |
1979 | their values after the call. */ | |
1980 | constexpr_ctx ctx_with_save_exprs = *ctx; | |
0ee28590 | 1981 | auto_vec<tree, 10> save_exprs; |
c0daf32d | 1982 | ctx_with_save_exprs.save_exprs = &save_exprs; |
1e163090 | 1983 | ctx_with_save_exprs.call = &new_call; |
c0daf32d | 1984 | |
0567dcd2 | 1985 | tree jump_target = NULL_TREE; |
c0daf32d | 1986 | cxx_eval_constant_expression (&ctx_with_save_exprs, body, |
0567dcd2 MP |
1987 | lval, non_constant_p, overflow_p, |
1988 | &jump_target); | |
60813a46 | 1989 | |
0567dcd2 MP |
1990 | if (DECL_CONSTRUCTOR_P (fun)) |
1991 | /* This can be null for a subobject constructor call, in | |
1992 | which case what we care about is the initialization | |
1993 | side-effects rather than the value. We could get at the | |
1994 | value by evaluating *this, but we don't bother; there's | |
1995 | no need to put such a call in the hash table. */ | |
1996 | result = lval ? ctx->object : ctx->ctor; | |
1997 | else if (VOID_TYPE_P (TREE_TYPE (res))) | |
1998 | result = void_node; | |
1999 | else | |
2000 | { | |
8e007055 | 2001 | result = *ctx->global->values.get (slot ? slot : res); |
0567dcd2 | 2002 | if (result == NULL_TREE && !*non_constant_p) |
60813a46 | 2003 | { |
0567dcd2 | 2004 | if (!ctx->quiet) |
84fa214d | 2005 | error ("%<constexpr%> call flows off the end " |
0567dcd2 MP |
2006 | "of the function"); |
2007 | *non_constant_p = true; | |
60813a46 | 2008 | } |
60813a46 | 2009 | } |
0567dcd2 | 2010 | |
04e1749c MP |
2011 | /* At this point, the object's constructor will have run, so |
2012 | the object is no longer under construction, and its possible | |
2013 | 'const' semantics now apply. Make a note of this fact by | |
2014 | marking the CONSTRUCTOR TREE_READONLY. */ | |
2015 | if (new_obj | |
2016 | && CLASS_TYPE_P (TREE_TYPE (new_obj)) | |
2017 | && CP_TYPE_CONST_P (TREE_TYPE (new_obj))) | |
2018 | { | |
8e007055 JJ |
2019 | /* Subobjects might not be stored in ctx->global->values but we |
2020 | can get its CONSTRUCTOR by evaluating *this. */ | |
04e1749c MP |
2021 | tree e = cxx_eval_constant_expression (ctx, new_obj, |
2022 | /*lval*/false, | |
2023 | non_constant_p, | |
2024 | overflow_p); | |
2025 | TREE_READONLY (e) = true; | |
2026 | } | |
2027 | ||
c0daf32d | 2028 | /* Forget the saved values of the callee's SAVE_EXPRs. */ |
0ee28590 JJ |
2029 | unsigned int i; |
2030 | tree save_expr; | |
2031 | FOR_EACH_VEC_ELT (save_exprs, i, save_expr) | |
8e007055 | 2032 | ctx->global->values.remove (save_expr); |
c0daf32d | 2033 | |
0567dcd2 MP |
2034 | /* Remove the parms/result from the values map. Is it worth |
2035 | bothering to do this when the map itself is only live for | |
2036 | one constexpr evaluation? If so, maybe also clear out | |
2037 | other vars from call, maybe in BIND_EXPR handling? */ | |
8e007055 | 2038 | ctx->global->values.remove (res); |
0567dcd2 | 2039 | if (slot) |
8e007055 | 2040 | ctx->global->values.remove (slot); |
0567dcd2 | 2041 | for (tree parm = parms; parm; parm = TREE_CHAIN (parm)) |
8e007055 | 2042 | ctx->global->values.remove (parm); |
c0daf32d | 2043 | |
620adbec JM |
2044 | /* Free any parameter CONSTRUCTORs we aren't returning directly. */ |
2045 | while (!ctors->is_empty ()) | |
2046 | { | |
2047 | tree c = ctors->pop (); | |
2048 | if (c != result) | |
2049 | free_constructor (c); | |
2050 | } | |
2051 | ||
c0daf32d PP |
2052 | /* Make the unshared function copy we used available for re-use. */ |
2053 | save_fundef_copy (fun, copy); | |
3e605b20 | 2054 | } |
60813a46 | 2055 | |
2d76680f PC |
2056 | if (result == error_mark_node) |
2057 | *non_constant_p = true; | |
52228180 | 2058 | if (*non_constant_p || *overflow_p) |
12d9ce19 | 2059 | result = error_mark_node; |
0567dcd2 | 2060 | else if (!result) |
60813a46 | 2061 | result = void_node; |
12d9ce19 JM |
2062 | if (entry) |
2063 | entry->result = result; | |
2d76680f PC |
2064 | } |
2065 | ||
f64e0c02 JM |
2066 | /* The result of a constexpr function must be completely initialized. */ |
2067 | if (TREE_CODE (result) == CONSTRUCTOR) | |
ecc57615 | 2068 | clear_no_implicit_zero (result); |
f64e0c02 | 2069 | |
2d76680f | 2070 | pop_cx_call_context (); |
9b9eb42a | 2071 | return result; |
2d76680f PC |
2072 | } |
2073 | ||
2074 | /* FIXME speed this up, it's taking 16% of compile time on sieve testcase. */ | |
2075 | ||
2076 | bool | |
2077 | reduced_constant_expression_p (tree t) | |
2078 | { | |
4930c53e MP |
2079 | if (t == NULL_TREE) |
2080 | return false; | |
2081 | ||
2d76680f PC |
2082 | switch (TREE_CODE (t)) |
2083 | { | |
2084 | case PTRMEM_CST: | |
2085 | /* Even if we can't lower this yet, it's constant. */ | |
2086 | return true; | |
2087 | ||
2088 | case CONSTRUCTOR: | |
2089 | /* And we need to handle PTRMEM_CST wrapped in a CONSTRUCTOR. */ | |
7368cfa4 | 2090 | tree idx, val, field; unsigned HOST_WIDE_INT i; |
e8c48716 | 2091 | if (CONSTRUCTOR_NO_CLEARING (t)) |
6f11ddd8 JM |
2092 | { |
2093 | if (TREE_CODE (TREE_TYPE (t)) == VECTOR_TYPE) | |
2094 | /* An initialized vector would have a VECTOR_CST. */ | |
2095 | return false; | |
2096 | else | |
2097 | field = next_initializable_field (TYPE_FIELDS (TREE_TYPE (t))); | |
2098 | } | |
7368cfa4 JM |
2099 | else |
2100 | field = NULL_TREE; | |
2101 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (t), i, idx, val) | |
125db6a1 | 2102 | { |
4930c53e MP |
2103 | /* If VAL is null, we're in the middle of initializing this |
2104 | element. */ | |
7368cfa4 | 2105 | if (!reduced_constant_expression_p (val)) |
125db6a1 | 2106 | return false; |
7368cfa4 JM |
2107 | if (field) |
2108 | { | |
2109 | if (idx != field) | |
2110 | return false; | |
2111 | field = next_initializable_field (DECL_CHAIN (field)); | |
2112 | } | |
125db6a1 | 2113 | } |
7368cfa4 JM |
2114 | if (field) |
2115 | return false; | |
e8c48716 | 2116 | else if (CONSTRUCTOR_NO_CLEARING (t)) |
7368cfa4 | 2117 | /* All the fields are initialized. */ |
e8c48716 | 2118 | CONSTRUCTOR_NO_CLEARING (t) = false; |
2d76680f PC |
2119 | return true; |
2120 | ||
2121 | default: | |
2122 | /* FIXME are we calling this too much? */ | |
2123 | return initializer_constant_valid_p (t, TREE_TYPE (t)) != NULL_TREE; | |
2124 | } | |
2125 | } | |
2126 | ||
2127 | /* Some expressions may have constant operands but are not constant | |
7d75ea04 JJ |
2128 | themselves, such as 1/0. Call this function to check for that |
2129 | condition. | |
2d76680f PC |
2130 | |
2131 | We only call this in places that require an arithmetic constant, not in | |
2132 | places where we might have a non-constant expression that can be a | |
2133 | component of a constant expression, such as the address of a constexpr | |
2134 | variable that might be dereferenced later. */ | |
2135 | ||
2136 | static bool | |
2137 | verify_constant (tree t, bool allow_non_constant, bool *non_constant_p, | |
2138 | bool *overflow_p) | |
2139 | { | |
2140 | if (!*non_constant_p && !reduced_constant_expression_p (t)) | |
2141 | { | |
2142 | if (!allow_non_constant) | |
2143 | error ("%q+E is not a constant expression", t); | |
2144 | *non_constant_p = true; | |
2145 | } | |
2146 | if (TREE_OVERFLOW_P (t)) | |
2147 | { | |
2148 | if (!allow_non_constant) | |
2149 | { | |
2150 | permerror (input_location, "overflow in constant expression"); | |
2151 | /* If we're being permissive (and are in an enforcing | |
2152 | context), ignore the overflow. */ | |
2153 | if (flag_permissive) | |
2154 | return *non_constant_p; | |
2155 | } | |
2156 | *overflow_p = true; | |
2157 | } | |
2158 | return *non_constant_p; | |
2159 | } | |
2160 | ||
253a921b MP |
2161 | /* Check whether the shift operation with code CODE and type TYPE on LHS |
2162 | and RHS is undefined. If it is, give an error with an explanation, | |
2163 | and return true; return false otherwise. */ | |
2164 | ||
2165 | static bool | |
2166 | cxx_eval_check_shift_p (location_t loc, const constexpr_ctx *ctx, | |
2167 | enum tree_code code, tree type, tree lhs, tree rhs) | |
2168 | { | |
2169 | if ((code != LSHIFT_EXPR && code != RSHIFT_EXPR) | |
2170 | || TREE_CODE (lhs) != INTEGER_CST | |
2171 | || TREE_CODE (rhs) != INTEGER_CST) | |
2172 | return false; | |
2173 | ||
2174 | tree lhstype = TREE_TYPE (lhs); | |
2175 | unsigned HOST_WIDE_INT uprec = TYPE_PRECISION (TREE_TYPE (lhs)); | |
2176 | ||
2177 | /* [expr.shift] The behavior is undefined if the right operand | |
2178 | is negative, or greater than or equal to the length in bits | |
2179 | of the promoted left operand. */ | |
2180 | if (tree_int_cst_sgn (rhs) == -1) | |
2181 | { | |
2182 | if (!ctx->quiet) | |
5342156c MP |
2183 | permerror (loc, "right operand of shift expression %q+E is negative", |
2184 | build2_loc (loc, code, type, lhs, rhs)); | |
2185 | return (!flag_permissive || ctx->quiet); | |
253a921b MP |
2186 | } |
2187 | if (compare_tree_int (rhs, uprec) >= 0) | |
2188 | { | |
2189 | if (!ctx->quiet) | |
a9c697b8 MS |
2190 | permerror (loc, "right operand of shift expression %q+E is greater " |
2191 | "than or equal to the precision %wu of the left operand", | |
2192 | build2_loc (loc, code, type, lhs, rhs), uprec); | |
5342156c | 2193 | return (!flag_permissive || ctx->quiet); |
253a921b MP |
2194 | } |
2195 | ||
2196 | /* The value of E1 << E2 is E1 left-shifted E2 bit positions; [...] | |
2197 | if E1 has a signed type and non-negative value, and E1x2^E2 is | |
2198 | representable in the corresponding unsigned type of the result type, | |
2199 | then that value, converted to the result type, is the resulting value; | |
8ee09943 JJ |
2200 | otherwise, the behavior is undefined. |
2201 | For C++2a: | |
2202 | The value of E1 << E2 is the unique value congruent to E1 x 2^E2 modulo | |
2203 | 2^N, where N is the range exponent of the type of the result. */ | |
2204 | if (code == LSHIFT_EXPR | |
2205 | && !TYPE_UNSIGNED (lhstype) | |
2206 | && cxx_dialect >= cxx11 | |
2207 | && cxx_dialect < cxx2a) | |
253a921b MP |
2208 | { |
2209 | if (tree_int_cst_sgn (lhs) == -1) | |
2210 | { | |
2211 | if (!ctx->quiet) | |
5342156c MP |
2212 | permerror (loc, |
2213 | "left operand of shift expression %q+E is negative", | |
2214 | build2_loc (loc, code, type, lhs, rhs)); | |
2215 | return (!flag_permissive || ctx->quiet); | |
253a921b MP |
2216 | } |
2217 | /* For signed x << y the following: | |
2218 | (unsigned) x >> ((prec (lhs) - 1) - y) | |
2219 | if > 1, is undefined. The right-hand side of this formula | |
2220 | is the highest bit of the LHS that can be set (starting from 0), | |
2221 | so that the shift doesn't overflow. We then right-shift the LHS | |
2222 | to see whether any other bit is set making the original shift | |
2223 | undefined -- the result is not representable in the corresponding | |
2224 | unsigned type. */ | |
2225 | tree t = build_int_cst (unsigned_type_node, uprec - 1); | |
2226 | t = fold_build2 (MINUS_EXPR, unsigned_type_node, t, rhs); | |
2227 | tree ulhs = fold_convert (unsigned_type_for (lhstype), lhs); | |
2228 | t = fold_build2 (RSHIFT_EXPR, TREE_TYPE (ulhs), ulhs, t); | |
2229 | if (tree_int_cst_lt (integer_one_node, t)) | |
2230 | { | |
2231 | if (!ctx->quiet) | |
5342156c MP |
2232 | permerror (loc, "shift expression %q+E overflows", |
2233 | build2_loc (loc, code, type, lhs, rhs)); | |
2234 | return (!flag_permissive || ctx->quiet); | |
253a921b MP |
2235 | } |
2236 | } | |
2237 | return false; | |
2238 | } | |
2239 | ||
2d76680f PC |
2240 | /* Subroutine of cxx_eval_constant_expression. |
2241 | Attempt to reduce the unary expression tree T to a compile time value. | |
2242 | If successful, return the value. Otherwise issue a diagnostic | |
2243 | and return error_mark_node. */ | |
2244 | ||
2245 | static tree | |
3e605b20 | 2246 | cxx_eval_unary_expression (const constexpr_ctx *ctx, tree t, |
12d9ce19 | 2247 | bool /*lval*/, |
2d76680f PC |
2248 | bool *non_constant_p, bool *overflow_p) |
2249 | { | |
2250 | tree r; | |
2251 | tree orig_arg = TREE_OPERAND (t, 0); | |
12d9ce19 JM |
2252 | tree arg = cxx_eval_constant_expression (ctx, orig_arg, /*lval*/false, |
2253 | non_constant_p, overflow_p); | |
2d76680f | 2254 | VERIFY_CONSTANT (arg); |
f899317e JM |
2255 | location_t loc = EXPR_LOCATION (t); |
2256 | enum tree_code code = TREE_CODE (t); | |
2257 | tree type = TREE_TYPE (t); | |
2258 | r = fold_unary_loc (loc, code, type, arg); | |
2259 | if (r == NULL_TREE) | |
2260 | { | |
2261 | if (arg == orig_arg) | |
2262 | r = t; | |
2263 | else | |
2264 | r = build1_loc (loc, code, type, arg); | |
2265 | } | |
2d76680f PC |
2266 | VERIFY_CONSTANT (r); |
2267 | return r; | |
2268 | } | |
2269 | ||
ea8661cd JJ |
2270 | /* Helper function for cxx_eval_binary_expression. Try to optimize |
2271 | original POINTER_PLUS_EXPR T, LHS p+ RHS, return NULL_TREE if the | |
2272 | generic folding should be used. */ | |
2273 | ||
2274 | static tree | |
2275 | cxx_fold_pointer_plus_expression (const constexpr_ctx *ctx, tree t, | |
2276 | tree lhs, tree rhs, bool *non_constant_p, | |
2277 | bool *overflow_p) | |
2278 | { | |
2279 | STRIP_NOPS (lhs); | |
2280 | if (TREE_CODE (lhs) != ADDR_EXPR) | |
2281 | return NULL_TREE; | |
2282 | ||
2283 | lhs = TREE_OPERAND (lhs, 0); | |
2284 | ||
2285 | /* &A[i] p+ j => &A[i + j] */ | |
2286 | if (TREE_CODE (lhs) == ARRAY_REF | |
2287 | && TREE_CODE (TREE_OPERAND (lhs, 1)) == INTEGER_CST | |
2288 | && TREE_CODE (rhs) == INTEGER_CST | |
2289 | && TYPE_SIZE_UNIT (TREE_TYPE (lhs)) | |
2290 | && TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (lhs))) == INTEGER_CST) | |
2291 | { | |
2292 | tree orig_type = TREE_TYPE (t); | |
2293 | location_t loc = EXPR_LOCATION (t); | |
2294 | tree type = TREE_TYPE (lhs); | |
2295 | ||
2296 | t = fold_convert_loc (loc, ssizetype, TREE_OPERAND (lhs, 1)); | |
2297 | tree nelts = array_type_nelts_top (TREE_TYPE (TREE_OPERAND (lhs, 0))); | |
2298 | nelts = cxx_eval_constant_expression (ctx, nelts, false, non_constant_p, | |
2299 | overflow_p); | |
2300 | if (*non_constant_p) | |
2301 | return NULL_TREE; | |
2302 | /* Don't fold an out-of-bound access. */ | |
2303 | if (!tree_int_cst_le (t, nelts)) | |
2304 | return NULL_TREE; | |
2305 | rhs = cp_fold_convert (ssizetype, rhs); | |
2306 | /* Don't fold if rhs can't be divided exactly by TYPE_SIZE_UNIT. | |
2307 | constexpr int A[1]; ... (char *)&A[0] + 1 */ | |
2308 | if (!integer_zerop (fold_build2_loc (loc, TRUNC_MOD_EXPR, sizetype, | |
2309 | rhs, TYPE_SIZE_UNIT (type)))) | |
2310 | return NULL_TREE; | |
2311 | /* Make sure to treat the second operand of POINTER_PLUS_EXPR | |
2312 | as signed. */ | |
2313 | rhs = fold_build2_loc (loc, EXACT_DIV_EXPR, ssizetype, rhs, | |
2314 | TYPE_SIZE_UNIT (type)); | |
2315 | t = size_binop_loc (loc, PLUS_EXPR, rhs, t); | |
2316 | t = build4_loc (loc, ARRAY_REF, type, TREE_OPERAND (lhs, 0), | |
2317 | t, NULL_TREE, NULL_TREE); | |
2318 | t = cp_build_addr_expr (t, tf_warning_or_error); | |
2319 | t = cp_fold_convert (orig_type, t); | |
2320 | return cxx_eval_constant_expression (ctx, t, /*lval*/false, | |
2321 | non_constant_p, overflow_p); | |
2322 | } | |
2323 | ||
2324 | return NULL_TREE; | |
2325 | } | |
2326 | ||
2d76680f PC |
2327 | /* Subroutine of cxx_eval_constant_expression. |
2328 | Like cxx_eval_unary_expression, except for binary expressions. */ | |
2329 | ||
2330 | static tree | |
3e605b20 | 2331 | cxx_eval_binary_expression (const constexpr_ctx *ctx, tree t, |
12d9ce19 | 2332 | bool /*lval*/, |
2d76680f PC |
2333 | bool *non_constant_p, bool *overflow_p) |
2334 | { | |
618d6c1c | 2335 | tree r = NULL_TREE; |
2d76680f PC |
2336 | tree orig_lhs = TREE_OPERAND (t, 0); |
2337 | tree orig_rhs = TREE_OPERAND (t, 1); | |
2338 | tree lhs, rhs; | |
12d9ce19 | 2339 | lhs = cxx_eval_constant_expression (ctx, orig_lhs, /*lval*/false, |
5a804683 | 2340 | non_constant_p, overflow_p); |
c8a66fc9 JM |
2341 | /* Don't VERIFY_CONSTANT here, it's unnecessary and will break pointer |
2342 | subtraction. */ | |
2343 | if (*non_constant_p) | |
2344 | return t; | |
12d9ce19 | 2345 | rhs = cxx_eval_constant_expression (ctx, orig_rhs, /*lval*/false, |
5a804683 | 2346 | non_constant_p, overflow_p); |
c8a66fc9 JM |
2347 | if (*non_constant_p) |
2348 | return t; | |
f899317e JM |
2349 | |
2350 | location_t loc = EXPR_LOCATION (t); | |
2351 | enum tree_code code = TREE_CODE (t); | |
2352 | tree type = TREE_TYPE (t); | |
618d6c1c PP |
2353 | |
2354 | if (code == EQ_EXPR || code == NE_EXPR) | |
2355 | { | |
2356 | bool is_code_eq = (code == EQ_EXPR); | |
2357 | ||
2358 | if (TREE_CODE (lhs) == PTRMEM_CST | |
2359 | && TREE_CODE (rhs) == PTRMEM_CST) | |
9b0607de JM |
2360 | { |
2361 | tree lmem = PTRMEM_CST_MEMBER (lhs); | |
2362 | tree rmem = PTRMEM_CST_MEMBER (rhs); | |
2363 | bool eq; | |
2364 | if (TREE_CODE (lmem) == TREE_CODE (rmem) | |
2365 | && TREE_CODE (lmem) == FIELD_DECL | |
2366 | && TREE_CODE (DECL_CONTEXT (lmem)) == UNION_TYPE | |
2367 | && same_type_p (DECL_CONTEXT (lmem), | |
2368 | DECL_CONTEXT (rmem))) | |
2369 | /* If both refer to (possibly different) members of the same union | |
2370 | (12.3), they compare equal. */ | |
2371 | eq = true; | |
2372 | else | |
2373 | eq = cp_tree_equal (lhs, rhs); | |
2374 | r = constant_boolean_node (eq == is_code_eq, type); | |
2375 | } | |
618d6c1c PP |
2376 | else if ((TREE_CODE (lhs) == PTRMEM_CST |
2377 | || TREE_CODE (rhs) == PTRMEM_CST) | |
2378 | && (null_member_pointer_value_p (lhs) | |
2379 | || null_member_pointer_value_p (rhs))) | |
2380 | r = constant_boolean_node (!is_code_eq, type); | |
dd5dda56 JM |
2381 | else if (TREE_CODE (lhs) == PTRMEM_CST) |
2382 | lhs = cplus_expand_constant (lhs); | |
2383 | else if (TREE_CODE (rhs) == PTRMEM_CST) | |
2384 | rhs = cplus_expand_constant (rhs); | |
618d6c1c | 2385 | } |
8bada5cd MS |
2386 | if (code == POINTER_PLUS_EXPR && !*non_constant_p |
2387 | && integer_zerop (lhs) && !integer_zerop (rhs)) | |
2388 | { | |
2389 | if (!ctx->quiet) | |
2390 | error ("arithmetic involving a null pointer in %qE", lhs); | |
bf533db8 | 2391 | *non_constant_p = true; |
8bada5cd MS |
2392 | return t; |
2393 | } | |
ea8661cd JJ |
2394 | else if (code == POINTER_PLUS_EXPR) |
2395 | r = cxx_fold_pointer_plus_expression (ctx, t, lhs, rhs, non_constant_p, | |
2396 | overflow_p); | |
618d6c1c PP |
2397 | |
2398 | if (r == NULL_TREE) | |
2399 | r = fold_binary_loc (loc, code, type, lhs, rhs); | |
2400 | ||
f899317e JM |
2401 | if (r == NULL_TREE) |
2402 | { | |
2403 | if (lhs == orig_lhs && rhs == orig_rhs) | |
2404 | r = t; | |
2405 | else | |
2406 | r = build2_loc (loc, code, type, lhs, rhs); | |
2407 | } | |
253a921b MP |
2408 | else if (cxx_eval_check_shift_p (loc, ctx, code, type, lhs, rhs)) |
2409 | *non_constant_p = true; | |
c8a66fc9 JM |
2410 | /* Don't VERIFY_CONSTANT if this might be dealing with a pointer to |
2411 | a local array in a constexpr function. */ | |
71a93b08 | 2412 | bool ptr = INDIRECT_TYPE_P (TREE_TYPE (lhs)); |
caee690e | 2413 | if (!ptr) |
134efa82 | 2414 | VERIFY_CONSTANT (r); |
2d76680f PC |
2415 | return r; |
2416 | } | |
2417 | ||
2418 | /* Subroutine of cxx_eval_constant_expression. | |
2419 | Attempt to evaluate condition expressions. Dead branches are not | |
2420 | looked into. */ | |
2421 | ||
2422 | static tree | |
3e605b20 | 2423 | cxx_eval_conditional_expression (const constexpr_ctx *ctx, tree t, |
92a596e8 | 2424 | bool lval, |
56632b27 JM |
2425 | bool *non_constant_p, bool *overflow_p, |
2426 | tree *jump_target) | |
2d76680f | 2427 | { |
3e605b20 | 2428 | tree val = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), |
12d9ce19 | 2429 | /*lval*/false, |
5a804683 | 2430 | non_constant_p, overflow_p); |
2d76680f PC |
2431 | VERIFY_CONSTANT (val); |
2432 | /* Don't VERIFY_CONSTANT the other operands. */ | |
2433 | if (integer_zerop (val)) | |
43574e4f JJ |
2434 | val = TREE_OPERAND (t, 2); |
2435 | else | |
2436 | val = TREE_OPERAND (t, 1); | |
2437 | if (TREE_CODE (t) == IF_STMT && !val) | |
2438 | val = void_node; | |
2439 | return cxx_eval_constant_expression (ctx, val, lval, non_constant_p, | |
2440 | overflow_p, jump_target); | |
2d76680f PC |
2441 | } |
2442 | ||
f370e36d JJ |
2443 | /* Subroutine of cxx_eval_constant_expression. |
2444 | Attempt to evaluate vector condition expressions. Unlike | |
2445 | cxx_eval_conditional_expression, VEC_COND_EXPR acts like a normal | |
2446 | ternary arithmetics operation, where all 3 arguments have to be | |
2447 | evaluated as constants and then folding computes the result from | |
2448 | them. */ | |
2449 | ||
2450 | static tree | |
2451 | cxx_eval_vector_conditional_expression (const constexpr_ctx *ctx, tree t, | |
2452 | bool *non_constant_p, bool *overflow_p) | |
2453 | { | |
2454 | tree arg1 = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), | |
2455 | /*lval*/false, | |
2456 | non_constant_p, overflow_p); | |
2457 | VERIFY_CONSTANT (arg1); | |
2458 | tree arg2 = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), | |
2459 | /*lval*/false, | |
2460 | non_constant_p, overflow_p); | |
2461 | VERIFY_CONSTANT (arg2); | |
2462 | tree arg3 = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 2), | |
2463 | /*lval*/false, | |
2464 | non_constant_p, overflow_p); | |
2465 | VERIFY_CONSTANT (arg3); | |
2466 | location_t loc = EXPR_LOCATION (t); | |
2467 | tree type = TREE_TYPE (t); | |
2468 | tree r = fold_ternary_loc (loc, VEC_COND_EXPR, type, arg1, arg2, arg3); | |
2469 | if (r == NULL_TREE) | |
2470 | { | |
2471 | if (arg1 == TREE_OPERAND (t, 0) | |
2472 | && arg2 == TREE_OPERAND (t, 1) | |
2473 | && arg3 == TREE_OPERAND (t, 2)) | |
2474 | r = t; | |
2475 | else | |
2476 | r = build3_loc (loc, VEC_COND_EXPR, type, arg1, arg2, arg3); | |
2477 | } | |
2478 | VERIFY_CONSTANT (r); | |
2479 | return r; | |
2480 | } | |
2481 | ||
ceaaf873 JM |
2482 | /* Returns less than, equal to, or greater than zero if KEY is found to be |
2483 | less than, to match, or to be greater than the constructor_elt's INDEX. */ | |
2484 | ||
2485 | static int | |
2486 | array_index_cmp (tree key, tree index) | |
2487 | { | |
2488 | gcc_assert (TREE_CODE (key) == INTEGER_CST); | |
2489 | ||
2490 | switch (TREE_CODE (index)) | |
2491 | { | |
2492 | case INTEGER_CST: | |
2493 | return tree_int_cst_compare (key, index); | |
2494 | case RANGE_EXPR: | |
2495 | { | |
2496 | tree lo = TREE_OPERAND (index, 0); | |
2497 | tree hi = TREE_OPERAND (index, 1); | |
2498 | if (tree_int_cst_lt (key, lo)) | |
2499 | return -1; | |
2500 | else if (tree_int_cst_lt (hi, key)) | |
2501 | return 1; | |
2502 | else | |
2503 | return 0; | |
2504 | } | |
2505 | default: | |
2506 | gcc_unreachable (); | |
2507 | } | |
2508 | } | |
2509 | ||
2510 | /* Returns the index of the constructor_elt of ARY which matches DINDEX, or -1 | |
2511 | if none. If INSERT is true, insert a matching element rather than fail. */ | |
2512 | ||
2513 | static HOST_WIDE_INT | |
582d2481 | 2514 | find_array_ctor_elt (tree ary, tree dindex, bool insert) |
ceaaf873 JM |
2515 | { |
2516 | if (tree_int_cst_sgn (dindex) < 0) | |
2517 | return -1; | |
2518 | ||
2519 | unsigned HOST_WIDE_INT i = tree_to_uhwi (dindex); | |
2520 | vec<constructor_elt, va_gc> *elts = CONSTRUCTOR_ELTS (ary); | |
2521 | unsigned HOST_WIDE_INT len = vec_safe_length (elts); | |
2522 | ||
2523 | unsigned HOST_WIDE_INT end = len; | |
2524 | unsigned HOST_WIDE_INT begin = 0; | |
2525 | ||
2526 | /* If the last element of the CONSTRUCTOR has its own index, we can assume | |
2527 | that the same is true of the other elements and index directly. */ | |
2528 | if (end > 0) | |
2529 | { | |
fe217ba0 | 2530 | tree cindex = (*elts)[end - 1].index; |
ceaaf873 | 2531 | if (TREE_CODE (cindex) == INTEGER_CST |
fe217ba0 | 2532 | && compare_tree_int (cindex, end - 1) == 0) |
ceaaf873 JM |
2533 | { |
2534 | if (i < end) | |
2535 | return i; | |
2536 | else | |
2537 | begin = end; | |
2538 | } | |
2539 | } | |
2540 | ||
2541 | /* Otherwise, find a matching index by means of a binary search. */ | |
2542 | while (begin != end) | |
2543 | { | |
2544 | unsigned HOST_WIDE_INT middle = (begin + end) / 2; | |
a7ccb9e7 JM |
2545 | constructor_elt &elt = (*elts)[middle]; |
2546 | tree idx = elt.index; | |
ceaaf873 | 2547 | |
a7ccb9e7 | 2548 | int cmp = array_index_cmp (dindex, idx); |
ceaaf873 JM |
2549 | if (cmp < 0) |
2550 | end = middle; | |
2551 | else if (cmp > 0) | |
2552 | begin = middle + 1; | |
2553 | else | |
a7ccb9e7 JM |
2554 | { |
2555 | if (insert && TREE_CODE (idx) == RANGE_EXPR) | |
2556 | { | |
2557 | /* We need to split the range. */ | |
2558 | constructor_elt e; | |
2559 | tree lo = TREE_OPERAND (idx, 0); | |
2560 | tree hi = TREE_OPERAND (idx, 1); | |
fe217ba0 JJ |
2561 | tree value = elt.value; |
2562 | dindex = fold_convert (sizetype, dindex); | |
a7ccb9e7 JM |
2563 | if (tree_int_cst_lt (lo, dindex)) |
2564 | { | |
2565 | /* There are still some lower elts; shorten the range. */ | |
2566 | tree new_hi = int_const_binop (MINUS_EXPR, dindex, | |
2567 | size_one_node); | |
2568 | if (tree_int_cst_equal (lo, new_hi)) | |
2569 | /* Only one element left, no longer a range. */ | |
2570 | elt.index = lo; | |
2571 | else | |
2572 | TREE_OPERAND (idx, 1) = new_hi; | |
2573 | /* Append the element we want to insert. */ | |
2574 | ++middle; | |
2575 | e.index = dindex; | |
fe217ba0 | 2576 | e.value = unshare_constructor (value); |
a7ccb9e7 JM |
2577 | vec_safe_insert (CONSTRUCTOR_ELTS (ary), middle, e); |
2578 | } | |
2579 | else | |
2580 | /* No lower elts, the range elt is now ours. */ | |
2581 | elt.index = dindex; | |
2582 | ||
2583 | if (tree_int_cst_lt (dindex, hi)) | |
2584 | { | |
2585 | /* There are still some higher elts; append a range. */ | |
2586 | tree new_lo = int_const_binop (PLUS_EXPR, dindex, | |
2587 | size_one_node); | |
2588 | if (tree_int_cst_equal (new_lo, hi)) | |
2589 | e.index = hi; | |
2590 | else | |
2591 | e.index = build2 (RANGE_EXPR, sizetype, new_lo, hi); | |
fe217ba0 JJ |
2592 | e.value = unshare_constructor (value); |
2593 | vec_safe_insert (CONSTRUCTOR_ELTS (ary), middle + 1, e); | |
a7ccb9e7 JM |
2594 | } |
2595 | } | |
2596 | return middle; | |
2597 | } | |
ceaaf873 JM |
2598 | } |
2599 | ||
2600 | if (insert) | |
2601 | { | |
2602 | constructor_elt e = { dindex, NULL_TREE }; | |
2603 | vec_safe_insert (CONSTRUCTOR_ELTS (ary), end, e); | |
2604 | return end; | |
2605 | } | |
2606 | ||
2607 | return -1; | |
2608 | } | |
2609 | ||
abdc16c8 MS |
2610 | /* Under the control of CTX, issue a detailed diagnostic for |
2611 | an out-of-bounds subscript INDEX into the expression ARRAY. */ | |
2612 | ||
2613 | static void | |
043666e0 | 2614 | diag_array_subscript (location_t loc, const constexpr_ctx *ctx, tree array, tree index) |
abdc16c8 MS |
2615 | { |
2616 | if (!ctx->quiet) | |
2617 | { | |
2618 | tree arraytype = TREE_TYPE (array); | |
2619 | ||
2620 | /* Convert the unsigned array subscript to a signed integer to avoid | |
2621 | printing huge numbers for small negative values. */ | |
2622 | tree sidx = fold_convert (ssizetype, index); | |
043666e0 | 2623 | STRIP_ANY_LOCATION_WRAPPER (array); |
abdc16c8 MS |
2624 | if (DECL_P (array)) |
2625 | { | |
08b3748c | 2626 | if (TYPE_DOMAIN (arraytype)) |
043666e0 JM |
2627 | error_at (loc, "array subscript value %qE is outside the bounds " |
2628 | "of array %qD of type %qT", sidx, array, arraytype); | |
08b3748c | 2629 | else |
043666e0 JM |
2630 | error_at (loc, "nonzero array subscript %qE is used with array %qD of " |
2631 | "type %qT with unknown bounds", sidx, array, arraytype); | |
abdc16c8 MS |
2632 | inform (DECL_SOURCE_LOCATION (array), "declared here"); |
2633 | } | |
08b3748c | 2634 | else if (TYPE_DOMAIN (arraytype)) |
043666e0 JM |
2635 | error_at (loc, "array subscript value %qE is outside the bounds " |
2636 | "of array type %qT", sidx, arraytype); | |
08b3748c | 2637 | else |
043666e0 JM |
2638 | error_at (loc, "nonzero array subscript %qE is used with array of type %qT " |
2639 | "with unknown bounds", sidx, arraytype); | |
abdc16c8 MS |
2640 | } |
2641 | } | |
ceaaf873 | 2642 | |
74f8705e MP |
2643 | /* Return the number of elements for TYPE (which is an ARRAY_TYPE or |
2644 | a VECTOR_TYPE). */ | |
2645 | ||
2646 | static tree | |
2647 | get_array_or_vector_nelts (const constexpr_ctx *ctx, tree type, | |
2648 | bool *non_constant_p, bool *overflow_p) | |
2649 | { | |
2650 | tree nelts; | |
2651 | if (TREE_CODE (type) == ARRAY_TYPE) | |
2652 | { | |
2653 | if (TYPE_DOMAIN (type)) | |
2654 | nelts = array_type_nelts_top (type); | |
2655 | else | |
2656 | nelts = size_zero_node; | |
2657 | } | |
2658 | else if (VECTOR_TYPE_P (type)) | |
2659 | nelts = size_int (TYPE_VECTOR_SUBPARTS (type)); | |
2660 | else | |
2661 | gcc_unreachable (); | |
2662 | ||
2663 | /* For VLAs, the number of elements won't be an integer constant. */ | |
2664 | nelts = cxx_eval_constant_expression (ctx, nelts, false, | |
2665 | non_constant_p, overflow_p); | |
2666 | return nelts; | |
2667 | } | |
2668 | ||
d6b46fca NS |
2669 | /* Extract element INDEX consisting of CHARS_PER_ELT chars from |
2670 | STRING_CST STRING. */ | |
2671 | ||
2672 | static tree | |
2673 | extract_string_elt (tree string, unsigned chars_per_elt, unsigned index) | |
2674 | { | |
2675 | tree type = cv_unqualified (TREE_TYPE (TREE_TYPE (string))); | |
2676 | tree r; | |
2677 | ||
2678 | if (chars_per_elt == 1) | |
2679 | r = build_int_cst (type, TREE_STRING_POINTER (string)[index]); | |
2680 | else | |
2681 | { | |
2682 | const unsigned char *ptr | |
2683 | = ((const unsigned char *)TREE_STRING_POINTER (string) | |
2684 | + index * chars_per_elt); | |
2685 | r = native_interpret_expr (type, ptr, chars_per_elt); | |
2686 | } | |
2687 | return r; | |
2688 | } | |
2689 | ||
043666e0 JM |
2690 | /* Subroutine of cxx_eval_array_reference. T is an ARRAY_REF; evaluate the |
2691 | subscript, diagnose any problems with it, and return the result. */ | |
2692 | ||
2693 | static tree | |
2694 | eval_and_check_array_index (const constexpr_ctx *ctx, | |
2695 | tree t, bool allow_one_past, | |
2696 | bool *non_constant_p, bool *overflow_p) | |
2697 | { | |
f9d0ca40 | 2698 | location_t loc = cp_expr_loc_or_input_loc (t); |
043666e0 JM |
2699 | tree ary = TREE_OPERAND (t, 0); |
2700 | t = TREE_OPERAND (t, 1); | |
2701 | tree index = cxx_eval_constant_expression (ctx, t, false, | |
2702 | non_constant_p, overflow_p); | |
2703 | VERIFY_CONSTANT (index); | |
2704 | ||
2705 | if (!tree_fits_shwi_p (index) | |
2706 | || tree_int_cst_sgn (index) < 0) | |
2707 | { | |
2708 | diag_array_subscript (loc, ctx, ary, index); | |
2709 | *non_constant_p = true; | |
2710 | return t; | |
2711 | } | |
2712 | ||
2713 | tree nelts = get_array_or_vector_nelts (ctx, TREE_TYPE (ary), non_constant_p, | |
2714 | overflow_p); | |
2715 | VERIFY_CONSTANT (nelts); | |
2716 | if (allow_one_past | |
2717 | ? !tree_int_cst_le (index, nelts) | |
2718 | : !tree_int_cst_lt (index, nelts)) | |
2719 | { | |
2720 | diag_array_subscript (loc, ctx, ary, index); | |
2721 | *non_constant_p = true; | |
2722 | return t; | |
2723 | } | |
2724 | ||
2725 | return index; | |
2726 | } | |
2727 | ||
2d76680f PC |
2728 | /* Subroutine of cxx_eval_constant_expression. |
2729 | Attempt to reduce a reference to an array slot. */ | |
2730 | ||
2731 | static tree | |
3e605b20 | 2732 | cxx_eval_array_reference (const constexpr_ctx *ctx, tree t, |
92a596e8 | 2733 | bool lval, |
2d76680f PC |
2734 | bool *non_constant_p, bool *overflow_p) |
2735 | { | |
2736 | tree oldary = TREE_OPERAND (t, 0); | |
3e605b20 | 2737 | tree ary = cxx_eval_constant_expression (ctx, oldary, |
92a596e8 | 2738 | lval, |
5a804683 | 2739 | non_constant_p, overflow_p); |
2d76680f PC |
2740 | if (*non_constant_p) |
2741 | return t; | |
bc2687dd JJ |
2742 | if (!lval |
2743 | && TREE_CODE (ary) == VIEW_CONVERT_EXPR | |
043666e0 JM |
2744 | && VECTOR_TYPE_P (TREE_TYPE (TREE_OPERAND (ary, 0))) |
2745 | && TREE_TYPE (t) == TREE_TYPE (TREE_TYPE (TREE_OPERAND (ary, 0)))) | |
2746 | ary = TREE_OPERAND (ary, 0); | |
3b9997bb | 2747 | |
043666e0 JM |
2748 | tree oldidx = TREE_OPERAND (t, 1); |
2749 | tree index = eval_and_check_array_index (ctx, t, lval, | |
2750 | non_constant_p, overflow_p); | |
2751 | if (*non_constant_p) | |
2752 | return t; | |
5453bfed | 2753 | |
bc2a38df JJ |
2754 | if (lval && ary == oldary && index == oldidx) |
2755 | return t; | |
2756 | else if (lval) | |
2757 | return build4 (ARRAY_REF, TREE_TYPE (t), ary, index, NULL, NULL); | |
2758 | ||
043666e0 JM |
2759 | unsigned len = 0, elem_nchars = 1; |
2760 | tree elem_type = TREE_TYPE (TREE_TYPE (ary)); | |
2761 | if (TREE_CODE (ary) == CONSTRUCTOR) | |
2762 | len = CONSTRUCTOR_NELTS (ary); | |
2763 | else if (TREE_CODE (ary) == STRING_CST) | |
2764 | { | |
2765 | elem_nchars = (TYPE_PRECISION (elem_type) | |
2766 | / TYPE_PRECISION (char_type_node)); | |
2767 | len = (unsigned) TREE_STRING_LENGTH (ary) / elem_nchars; | |
2768 | } | |
2769 | else if (TREE_CODE (ary) == VECTOR_CST) | |
2770 | /* We don't create variable-length VECTOR_CSTs. */ | |
2771 | len = VECTOR_CST_NELTS (ary).to_constant (); | |
2772 | else | |
2773 | { | |
2774 | /* We can't do anything with other tree codes, so use | |
2775 | VERIFY_CONSTANT to complain and fail. */ | |
2776 | VERIFY_CONSTANT (ary); | |
2777 | gcc_unreachable (); | |
2778 | } | |
2779 | ||
ceaaf873 | 2780 | bool found; |
043666e0 | 2781 | HOST_WIDE_INT i = 0; |
ceaaf873 JM |
2782 | if (TREE_CODE (ary) == CONSTRUCTOR) |
2783 | { | |
2784 | HOST_WIDE_INT ix = find_array_ctor_elt (ary, index); | |
2785 | found = (ix >= 0); | |
2786 | if (found) | |
2787 | i = ix; | |
3b9997bb | 2788 | } |
ceaaf873 | 2789 | else |
043666e0 JM |
2790 | { |
2791 | i = tree_to_shwi (index); | |
2792 | found = (i < len); | |
2793 | } | |
3b9997bb | 2794 | |
fd2bfee5 JM |
2795 | if (found) |
2796 | { | |
2797 | tree r; | |
2798 | if (TREE_CODE (ary) == CONSTRUCTOR) | |
2799 | r = (*CONSTRUCTOR_ELTS (ary))[i].value; | |
2800 | else if (TREE_CODE (ary) == VECTOR_CST) | |
2801 | r = VECTOR_CST_ELT (ary, i); | |
fd2bfee5 | 2802 | else |
d6b46fca NS |
2803 | r = extract_string_elt (ary, elem_nchars, i); |
2804 | ||
fd2bfee5 JM |
2805 | if (r) |
2806 | /* Don't VERIFY_CONSTANT here. */ | |
2807 | return r; | |
2d76680f | 2808 | |
fd2bfee5 | 2809 | /* Otherwise the element doesn't have a value yet. */ |
2d76680f | 2810 | } |
3b9997bb | 2811 | |
fd2bfee5 JM |
2812 | /* Not found. */ |
2813 | ||
2814 | if (TREE_CODE (ary) == CONSTRUCTOR | |
e8c48716 | 2815 | && CONSTRUCTOR_NO_CLEARING (ary)) |
2d76680f | 2816 | { |
fd2bfee5 JM |
2817 | /* 'ary' is part of the aggregate initializer we're currently |
2818 | building; if there's no initializer for this element yet, | |
2819 | that's an error. */ | |
2820 | if (!ctx->quiet) | |
2821 | error ("accessing uninitialized array element"); | |
2822 | *non_constant_p = true; | |
2823 | return t; | |
2d76680f | 2824 | } |
fd2bfee5 JM |
2825 | |
2826 | /* If it's within the array bounds but doesn't have an explicit | |
2827 | initializer, it's value-initialized. */ | |
2828 | tree val = build_value_init (elem_type, tf_warning_or_error); | |
2829 | return cxx_eval_constant_expression (ctx, val, lval, non_constant_p, | |
2830 | overflow_p); | |
2d76680f PC |
2831 | } |
2832 | ||
2833 | /* Subroutine of cxx_eval_constant_expression. | |
2834 | Attempt to reduce a field access of a value of class type. */ | |
2835 | ||
2836 | static tree | |
3e605b20 | 2837 | cxx_eval_component_reference (const constexpr_ctx *ctx, tree t, |
92a596e8 | 2838 | bool lval, |
2d76680f PC |
2839 | bool *non_constant_p, bool *overflow_p) |
2840 | { | |
2841 | unsigned HOST_WIDE_INT i; | |
2842 | tree field; | |
2843 | tree value; | |
2844 | tree part = TREE_OPERAND (t, 1); | |
2845 | tree orig_whole = TREE_OPERAND (t, 0); | |
3e605b20 | 2846 | tree whole = cxx_eval_constant_expression (ctx, orig_whole, |
92a596e8 | 2847 | lval, |
5a804683 | 2848 | non_constant_p, overflow_p); |
a7f8415c | 2849 | if (INDIRECT_REF_P (whole) |
bf533db8 JJ |
2850 | && integer_zerop (TREE_OPERAND (whole, 0))) |
2851 | { | |
2852 | if (!ctx->quiet) | |
2853 | error ("dereferencing a null pointer in %qE", orig_whole); | |
2854 | *non_constant_p = true; | |
2855 | return t; | |
2856 | } | |
8bada5cd | 2857 | |
dcdbc004 JM |
2858 | if (TREE_CODE (whole) == PTRMEM_CST) |
2859 | whole = cplus_expand_constant (whole); | |
2d76680f PC |
2860 | if (whole == orig_whole) |
2861 | return t; | |
92a596e8 | 2862 | if (lval) |
2d76680f PC |
2863 | return fold_build3 (COMPONENT_REF, TREE_TYPE (t), |
2864 | whole, part, NULL_TREE); | |
2865 | /* Don't VERIFY_CONSTANT here; we only want to check that we got a | |
2866 | CONSTRUCTOR. */ | |
2867 | if (!*non_constant_p && TREE_CODE (whole) != CONSTRUCTOR) | |
2868 | { | |
2b3ab879 | 2869 | if (!ctx->quiet) |
2d76680f PC |
2870 | error ("%qE is not a constant expression", orig_whole); |
2871 | *non_constant_p = true; | |
2872 | } | |
2873 | if (DECL_MUTABLE_P (part)) | |
2874 | { | |
2b3ab879 | 2875 | if (!ctx->quiet) |
2d76680f PC |
2876 | error ("mutable %qD is not usable in a constant expression", part); |
2877 | *non_constant_p = true; | |
2878 | } | |
2879 | if (*non_constant_p) | |
2880 | return t; | |
2db613e5 | 2881 | bool pmf = TYPE_PTRMEMFUNC_P (TREE_TYPE (whole)); |
2d76680f PC |
2882 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (whole), i, field, value) |
2883 | { | |
2db613e5 JM |
2884 | /* Use name match for PMF fields, as a variant will have a |
2885 | different FIELD_DECL with a different type. */ | |
2886 | if (pmf ? DECL_NAME (field) == DECL_NAME (part) | |
2887 | : field == part) | |
60813a46 JM |
2888 | { |
2889 | if (value) | |
5b884e94 JJ |
2890 | { |
2891 | STRIP_ANY_LOCATION_WRAPPER (value); | |
2892 | return value; | |
2893 | } | |
60813a46 JM |
2894 | else |
2895 | /* We're in the middle of initializing it. */ | |
2896 | break; | |
2897 | } | |
2d76680f PC |
2898 | } |
2899 | if (TREE_CODE (TREE_TYPE (whole)) == UNION_TYPE | |
2900 | && CONSTRUCTOR_NELTS (whole) > 0) | |
2901 | { | |
2902 | /* DR 1188 says we don't have to deal with this. */ | |
2b3ab879 | 2903 | if (!ctx->quiet) |
2d76680f PC |
2904 | error ("accessing %qD member instead of initialized %qD member in " |
2905 | "constant expression", part, CONSTRUCTOR_ELT (whole, 0)->index); | |
2906 | *non_constant_p = true; | |
2907 | return t; | |
2908 | } | |
2909 | ||
188e53bd JM |
2910 | /* We only create a CONSTRUCTOR for a subobject when we modify it, so empty |
2911 | classes never get represented; throw together a value now. */ | |
dbcd32f8 | 2912 | if (is_really_empty_class (TREE_TYPE (t), /*ignore_vptr*/false)) |
188e53bd JM |
2913 | return build_constructor (TREE_TYPE (t), NULL); |
2914 | ||
2db613e5 JM |
2915 | gcc_assert (DECL_CONTEXT (part) == TYPE_MAIN_VARIANT (TREE_TYPE (whole))); |
2916 | ||
e8c48716 | 2917 | if (CONSTRUCTOR_NO_CLEARING (whole)) |
3e605b20 JM |
2918 | { |
2919 | /* 'whole' is part of the aggregate initializer we're currently | |
2920 | building; if there's no initializer for this member yet, that's an | |
188e53bd | 2921 | error. */ |
2b3ab879 | 2922 | if (!ctx->quiet) |
3e605b20 JM |
2923 | error ("accessing uninitialized member %qD", part); |
2924 | *non_constant_p = true; | |
2925 | return t; | |
2926 | } | |
2927 | ||
2d76680f PC |
2928 | /* If there's no explicit init for this field, it's value-initialized. */ |
2929 | value = build_value_init (TREE_TYPE (t), tf_warning_or_error); | |
3e605b20 | 2930 | return cxx_eval_constant_expression (ctx, value, |
92a596e8 | 2931 | lval, |
5a804683 | 2932 | non_constant_p, overflow_p); |
2d76680f PC |
2933 | } |
2934 | ||
2935 | /* Subroutine of cxx_eval_constant_expression. | |
2936 | Attempt to reduce a field access of a value of class type that is | |
2937 | expressed as a BIT_FIELD_REF. */ | |
2938 | ||
2939 | static tree | |
3e605b20 | 2940 | cxx_eval_bit_field_ref (const constexpr_ctx *ctx, tree t, |
92a596e8 | 2941 | bool lval, |
2d76680f PC |
2942 | bool *non_constant_p, bool *overflow_p) |
2943 | { | |
2944 | tree orig_whole = TREE_OPERAND (t, 0); | |
2945 | tree retval, fldval, utype, mask; | |
2946 | bool fld_seen = false; | |
2947 | HOST_WIDE_INT istart, isize; | |
3e605b20 | 2948 | tree whole = cxx_eval_constant_expression (ctx, orig_whole, |
92a596e8 | 2949 | lval, |
5a804683 | 2950 | non_constant_p, overflow_p); |
2d76680f PC |
2951 | tree start, field, value; |
2952 | unsigned HOST_WIDE_INT i; | |
2953 | ||
2954 | if (whole == orig_whole) | |
2955 | return t; | |
2956 | /* Don't VERIFY_CONSTANT here; we only want to check that we got a | |
2957 | CONSTRUCTOR. */ | |
2958 | if (!*non_constant_p | |
2959 | && TREE_CODE (whole) != VECTOR_CST | |
2960 | && TREE_CODE (whole) != CONSTRUCTOR) | |
2961 | { | |
2b3ab879 | 2962 | if (!ctx->quiet) |
2d76680f PC |
2963 | error ("%qE is not a constant expression", orig_whole); |
2964 | *non_constant_p = true; | |
2965 | } | |
2966 | if (*non_constant_p) | |
2967 | return t; | |
2968 | ||
2969 | if (TREE_CODE (whole) == VECTOR_CST) | |
2970 | return fold_ternary (BIT_FIELD_REF, TREE_TYPE (t), whole, | |
2971 | TREE_OPERAND (t, 1), TREE_OPERAND (t, 2)); | |
2972 | ||
2973 | start = TREE_OPERAND (t, 2); | |
2974 | istart = tree_to_shwi (start); | |
2975 | isize = tree_to_shwi (TREE_OPERAND (t, 1)); | |
2976 | utype = TREE_TYPE (t); | |
2977 | if (!TYPE_UNSIGNED (utype)) | |
2978 | utype = build_nonstandard_integer_type (TYPE_PRECISION (utype), 1); | |
2979 | retval = build_int_cst (utype, 0); | |
2980 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (whole), i, field, value) | |
2981 | { | |
2982 | tree bitpos = bit_position (field); | |
5b884e94 | 2983 | STRIP_ANY_LOCATION_WRAPPER (value); |
2d76680f PC |
2984 | if (bitpos == start && DECL_SIZE (field) == TREE_OPERAND (t, 1)) |
2985 | return value; | |
2986 | if (TREE_CODE (TREE_TYPE (field)) == INTEGER_TYPE | |
2987 | && TREE_CODE (value) == INTEGER_CST | |
2988 | && tree_fits_shwi_p (bitpos) | |
2989 | && tree_fits_shwi_p (DECL_SIZE (field))) | |
2990 | { | |
2991 | HOST_WIDE_INT bit = tree_to_shwi (bitpos); | |
2992 | HOST_WIDE_INT sz = tree_to_shwi (DECL_SIZE (field)); | |
2993 | HOST_WIDE_INT shift; | |
2994 | if (bit >= istart && bit + sz <= istart + isize) | |
2995 | { | |
2996 | fldval = fold_convert (utype, value); | |
2997 | mask = build_int_cst_type (utype, -1); | |
2998 | mask = fold_build2 (LSHIFT_EXPR, utype, mask, | |
2999 | size_int (TYPE_PRECISION (utype) - sz)); | |
3000 | mask = fold_build2 (RSHIFT_EXPR, utype, mask, | |
3001 | size_int (TYPE_PRECISION (utype) - sz)); | |
3002 | fldval = fold_build2 (BIT_AND_EXPR, utype, fldval, mask); | |
3003 | shift = bit - istart; | |
3004 | if (BYTES_BIG_ENDIAN) | |
3005 | shift = TYPE_PRECISION (utype) - shift - sz; | |
3006 | fldval = fold_build2 (LSHIFT_EXPR, utype, fldval, | |
3007 | size_int (shift)); | |
3008 | retval = fold_build2 (BIT_IOR_EXPR, utype, retval, fldval); | |
3009 | fld_seen = true; | |
3010 | } | |
3011 | } | |
3012 | } | |
3013 | if (fld_seen) | |
3014 | return fold_convert (TREE_TYPE (t), retval); | |
3015 | gcc_unreachable (); | |
3016 | return error_mark_node; | |
3017 | } | |
3018 | ||
3019 | /* Subroutine of cxx_eval_constant_expression. | |
3020 | Evaluate a short-circuited logical expression T in the context | |
3021 | of a given constexpr CALL. BAILOUT_VALUE is the value for | |
3022 | early return. CONTINUE_VALUE is used here purely for | |
3023 | sanity check purposes. */ | |
3024 | ||
3025 | static tree | |
3e605b20 | 3026 | cxx_eval_logical_expression (const constexpr_ctx *ctx, tree t, |
2d76680f | 3027 | tree bailout_value, tree continue_value, |
92a596e8 | 3028 | bool lval, |
2d76680f PC |
3029 | bool *non_constant_p, bool *overflow_p) |
3030 | { | |
3031 | tree r; | |
3e605b20 | 3032 | tree lhs = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), |
92a596e8 | 3033 | lval, |
5a804683 | 3034 | non_constant_p, overflow_p); |
2d76680f PC |
3035 | VERIFY_CONSTANT (lhs); |
3036 | if (tree_int_cst_equal (lhs, bailout_value)) | |
3037 | return lhs; | |
3038 | gcc_assert (tree_int_cst_equal (lhs, continue_value)); | |
3e605b20 | 3039 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), |
92a596e8 | 3040 | lval, non_constant_p, |
5a804683 | 3041 | overflow_p); |
2d76680f PC |
3042 | VERIFY_CONSTANT (r); |
3043 | return r; | |
3044 | } | |
3045 | ||
3046 | /* REF is a COMPONENT_REF designating a particular field. V is a vector of | |
3047 | CONSTRUCTOR elements to initialize (part of) an object containing that | |
3048 | field. Return a pointer to the constructor_elt corresponding to the | |
3049 | initialization of the field. */ | |
3050 | ||
3051 | static constructor_elt * | |
3052 | base_field_constructor_elt (vec<constructor_elt, va_gc> *v, tree ref) | |
3053 | { | |
3054 | tree aggr = TREE_OPERAND (ref, 0); | |
3055 | tree field = TREE_OPERAND (ref, 1); | |
3056 | HOST_WIDE_INT i; | |
3057 | constructor_elt *ce; | |
3058 | ||
3059 | gcc_assert (TREE_CODE (ref) == COMPONENT_REF); | |
3060 | ||
3061 | if (TREE_CODE (aggr) == COMPONENT_REF) | |
3062 | { | |
3063 | constructor_elt *base_ce | |
3064 | = base_field_constructor_elt (v, aggr); | |
3065 | v = CONSTRUCTOR_ELTS (base_ce->value); | |
3066 | } | |
3067 | ||
3068 | for (i = 0; vec_safe_iterate (v, i, &ce); ++i) | |
3069 | if (ce->index == field) | |
3070 | return ce; | |
3071 | ||
3072 | gcc_unreachable (); | |
3073 | return NULL; | |
3074 | } | |
3075 | ||
3e605b20 JM |
3076 | /* Some of the expressions fed to the constexpr mechanism are calls to |
3077 | constructors, which have type void. In that case, return the type being | |
3078 | initialized by the constructor. */ | |
3079 | ||
3080 | static tree | |
3081 | initialized_type (tree t) | |
3082 | { | |
3083 | if (TYPE_P (t)) | |
3084 | return t; | |
5dab8b11 | 3085 | tree type = TREE_TYPE (t); |
4d0c18c6 | 3086 | if (TREE_CODE (t) == CALL_EXPR) |
3e605b20 JM |
3087 | { |
3088 | /* A constructor call has void type, so we need to look deeper. */ | |
3089 | tree fn = get_function_named_in_call (t); | |
3090 | if (fn && TREE_CODE (fn) == FUNCTION_DECL | |
3091 | && DECL_CXX_CONSTRUCTOR_P (fn)) | |
3092 | type = DECL_CONTEXT (fn); | |
3093 | } | |
4d0c18c6 JM |
3094 | else if (TREE_CODE (t) == COMPOUND_EXPR) |
3095 | return initialized_type (TREE_OPERAND (t, 1)); | |
5dab8b11 JM |
3096 | else if (TREE_CODE (t) == AGGR_INIT_EXPR) |
3097 | type = TREE_TYPE (AGGR_INIT_EXPR_SLOT (t)); | |
3098 | return cv_unqualified (type); | |
3e605b20 JM |
3099 | } |
3100 | ||
3101 | /* We're about to initialize element INDEX of an array or class from VALUE. | |
3102 | Set up NEW_CTX appropriately by adjusting .object to refer to the | |
3103 | subobject and creating a new CONSTRUCTOR if the element is itself | |
3104 | a class or array. */ | |
3105 | ||
3106 | static void | |
3107 | init_subob_ctx (const constexpr_ctx *ctx, constexpr_ctx &new_ctx, | |
3108 | tree index, tree &value) | |
3109 | { | |
3110 | new_ctx = *ctx; | |
3111 | ||
3112 | if (index && TREE_CODE (index) != INTEGER_CST | |
3113 | && TREE_CODE (index) != FIELD_DECL) | |
3114 | /* This won't have an element in the new CONSTRUCTOR. */ | |
3115 | return; | |
3116 | ||
3117 | tree type = initialized_type (value); | |
3118 | if (!AGGREGATE_TYPE_P (type) && !VECTOR_TYPE_P (type)) | |
3119 | /* A non-aggregate member doesn't get its own CONSTRUCTOR. */ | |
3120 | return; | |
3121 | ||
3122 | /* The sub-aggregate initializer might contain a placeholder; | |
3123 | update object to refer to the subobject and ctor to refer to | |
3124 | the (newly created) sub-initializer. */ | |
3125 | if (ctx->object) | |
3126 | new_ctx.object = build_ctor_subob_ref (index, type, ctx->object); | |
3127 | tree elt = build_constructor (type, NULL); | |
e8c48716 | 3128 | CONSTRUCTOR_NO_CLEARING (elt) = true; |
3e605b20 JM |
3129 | new_ctx.ctor = elt; |
3130 | ||
3131 | if (TREE_CODE (value) == TARGET_EXPR) | |
3132 | /* Avoid creating another CONSTRUCTOR when we expand the TARGET_EXPR. */ | |
3133 | value = TARGET_EXPR_INITIAL (value); | |
3134 | } | |
3135 | ||
3136 | /* We're about to process an initializer for a class or array TYPE. Make | |
3137 | sure that CTX is set up appropriately. */ | |
3138 | ||
3139 | static void | |
3140 | verify_ctor_sanity (const constexpr_ctx *ctx, tree type) | |
3141 | { | |
3142 | /* We don't bother building a ctor for an empty base subobject. */ | |
3143 | if (is_empty_class (type)) | |
3144 | return; | |
3145 | ||
3146 | /* We're in the middle of an initializer that might involve placeholders; | |
3147 | our caller should have created a CONSTRUCTOR for us to put the | |
3148 | initializer into. We will either return that constructor or T. */ | |
3149 | gcc_assert (ctx->ctor); | |
3150 | gcc_assert (same_type_ignoring_top_level_qualifiers_p | |
3151 | (type, TREE_TYPE (ctx->ctor))); | |
fe69277d JM |
3152 | /* We used to check that ctx->ctor was empty, but that isn't the case when |
3153 | the object is zero-initialized before calling the constructor. */ | |
3e605b20 | 3154 | if (ctx->object) |
176e79b5 JM |
3155 | { |
3156 | tree otype = TREE_TYPE (ctx->object); | |
3157 | gcc_assert (same_type_ignoring_top_level_qualifiers_p (type, otype) | |
3158 | /* Handle flexible array members. */ | |
3159 | || (TREE_CODE (otype) == ARRAY_TYPE | |
3160 | && TYPE_DOMAIN (otype) == NULL_TREE | |
3161 | && TREE_CODE (type) == ARRAY_TYPE | |
3162 | && (same_type_ignoring_top_level_qualifiers_p | |
3163 | (TREE_TYPE (type), TREE_TYPE (otype))))); | |
3164 | } | |
3e605b20 | 3165 | gcc_assert (!ctx->object || !DECL_P (ctx->object) |
8e007055 | 3166 | || *(ctx->global->values.get (ctx->object)) == ctx->ctor); |
3e605b20 JM |
3167 | } |
3168 | ||
2d76680f PC |
3169 | /* Subroutine of cxx_eval_constant_expression. |
3170 | The expression tree T denotes a C-style array or a C-style | |
3171 | aggregate. Reduce it to a constant expression. */ | |
3172 | ||
3173 | static tree | |
3e605b20 | 3174 | cxx_eval_bare_aggregate (const constexpr_ctx *ctx, tree t, |
92a596e8 | 3175 | bool lval, |
2d76680f PC |
3176 | bool *non_constant_p, bool *overflow_p) |
3177 | { | |
3178 | vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (t); | |
2d76680f PC |
3179 | bool changed = false; |
3180 | gcc_assert (!BRACE_ENCLOSED_INITIALIZER_P (t)); | |
8a29084d | 3181 | tree type = TREE_TYPE (t); |
3e605b20 | 3182 | |
8a29084d | 3183 | constexpr_ctx new_ctx; |
d4619dc1 | 3184 | if (TYPE_PTRMEMFUNC_P (type) || VECTOR_TYPE_P (type)) |
8a29084d | 3185 | { |
d4619dc1 NS |
3186 | /* We don't really need the ctx->ctor business for a PMF or |
3187 | vector, but it's simpler to use the same code. */ | |
8a29084d JM |
3188 | new_ctx = *ctx; |
3189 | new_ctx.ctor = build_constructor (type, NULL); | |
3190 | new_ctx.object = NULL_TREE; | |
3191 | ctx = &new_ctx; | |
3192 | }; | |
3193 | verify_ctor_sanity (ctx, type); | |
3e605b20 JM |
3194 | vec<constructor_elt, va_gc> **p = &CONSTRUCTOR_ELTS (ctx->ctor); |
3195 | vec_alloc (*p, vec_safe_length (v)); | |
3196 | ||
2d63bc39 JM |
3197 | unsigned i; |
3198 | tree index, value; | |
3199 | bool constant_p = true; | |
3200 | bool side_effects_p = false; | |
3e605b20 | 3201 | FOR_EACH_CONSTRUCTOR_ELT (v, i, index, value) |
2d76680f | 3202 | { |
bcb5f3c9 | 3203 | tree orig_value = value; |
3e605b20 JM |
3204 | init_subob_ctx (ctx, new_ctx, index, value); |
3205 | if (new_ctx.ctor != ctx->ctor) | |
3206 | /* If we built a new CONSTRUCTOR, attach it now so that other | |
3207 | initializers can refer to it. */ | |
3208 | CONSTRUCTOR_APPEND_ELT (*p, index, new_ctx.ctor); | |
3209 | tree elt = cxx_eval_constant_expression (&new_ctx, value, | |
92a596e8 | 3210 | lval, |
5a804683 | 3211 | non_constant_p, overflow_p); |
2d76680f | 3212 | /* Don't VERIFY_CONSTANT here. */ |
2b3ab879 | 3213 | if (ctx->quiet && *non_constant_p) |
3e605b20 | 3214 | break; |
bcb5f3c9 | 3215 | if (elt != orig_value) |
2d76680f | 3216 | changed = true; |
2d63bc39 JM |
3217 | |
3218 | if (!TREE_CONSTANT (elt)) | |
3219 | constant_p = false; | |
3220 | if (TREE_SIDE_EFFECTS (elt)) | |
3221 | side_effects_p = true; | |
3e605b20 | 3222 | if (index && TREE_CODE (index) == COMPONENT_REF) |
2d76680f PC |
3223 | { |
3224 | /* This is an initialization of a vfield inside a base | |
3225 | subaggregate that we already initialized; push this | |
3226 | initialization into the previous initialization. */ | |
3e605b20 | 3227 | constructor_elt *inner = base_field_constructor_elt (*p, index); |
2d76680f | 3228 | inner->value = elt; |
3e605b20 | 3229 | changed = true; |
2d76680f | 3230 | } |
3e605b20 JM |
3231 | else if (index |
3232 | && (TREE_CODE (index) == NOP_EXPR | |
3233 | || TREE_CODE (index) == POINTER_PLUS_EXPR)) | |
2d76680f PC |
3234 | { |
3235 | /* This is an initializer for an empty base; now that we've | |
3236 | checked that it's constant, we can ignore it. */ | |
3e605b20 JM |
3237 | gcc_assert (is_empty_class (TREE_TYPE (TREE_TYPE (index)))); |
3238 | changed = true; | |
3239 | } | |
2d76680f | 3240 | else |
ac9ec198 | 3241 | { |
1bdbef09 MP |
3242 | if (new_ctx.ctor != ctx->ctor) |
3243 | { | |
3244 | /* We appended this element above; update the value. */ | |
3245 | gcc_assert ((*p)->last().index == index); | |
3246 | (*p)->last().value = elt; | |
3247 | } | |
3248 | else | |
3249 | CONSTRUCTOR_APPEND_ELT (*p, index, elt); | |
3250 | /* Adding or replacing an element might change the ctor's flags. */ | |
ac9ec198 MP |
3251 | TREE_CONSTANT (ctx->ctor) = constant_p; |
3252 | TREE_SIDE_EFFECTS (ctx->ctor) = side_effects_p; | |
3253 | } | |
2d76680f PC |
3254 | } |
3255 | if (*non_constant_p || !changed) | |
3e605b20 JM |
3256 | return t; |
3257 | t = ctx->ctor; | |
3258 | /* We're done building this CONSTRUCTOR, so now we can interpret an | |
3259 | element without an explicit initializer as value-initialized. */ | |
e8c48716 | 3260 | CONSTRUCTOR_NO_CLEARING (t) = false; |
2d63bc39 JM |
3261 | TREE_CONSTANT (t) = constant_p; |
3262 | TREE_SIDE_EFFECTS (t) = side_effects_p; | |
8a29084d | 3263 | if (VECTOR_TYPE_P (type)) |
2d76680f PC |
3264 | t = fold (t); |
3265 | return t; | |
3266 | } | |
3267 | ||
3268 | /* Subroutine of cxx_eval_constant_expression. | |
3269 | The expression tree T is a VEC_INIT_EXPR which denotes the desired | |
3270 | initialization of a non-static data member of array type. Reduce it to a | |
3271 | CONSTRUCTOR. | |
3272 | ||
3273 | Note that apart from value-initialization (when VALUE_INIT is true), | |
3274 | this is only intended to support value-initialization and the | |
3275 | initializations done by defaulted constructors for classes with | |
3276 | non-static data members of array type. In this case, VEC_INIT_EXPR_INIT | |
3277 | will either be NULL_TREE for the default constructor, or a COMPONENT_REF | |
3278 | for the copy/move constructor. */ | |
3279 | ||
3280 | static tree | |
3e605b20 | 3281 | cxx_eval_vec_init_1 (const constexpr_ctx *ctx, tree atype, tree init, |
92a596e8 | 3282 | bool value_init, bool lval, |
2d76680f PC |
3283 | bool *non_constant_p, bool *overflow_p) |
3284 | { | |
3285 | tree elttype = TREE_TYPE (atype); | |
3e605b20 JM |
3286 | verify_ctor_sanity (ctx, atype); |
3287 | vec<constructor_elt, va_gc> **p = &CONSTRUCTOR_ELTS (ctx->ctor); | |
2d76680f | 3288 | bool pre_init = false; |
4784470a | 3289 | unsigned HOST_WIDE_INT i; |
dc5ca6c8 | 3290 | tsubst_flags_t complain = ctx->quiet ? tf_none : tf_warning_or_error; |
2d76680f PC |
3291 | |
3292 | /* For the default constructor, build up a call to the default | |
3293 | constructor of the element type. We only need to handle class types | |
3294 | here, as for a constructor to be constexpr, all members must be | |
3295 | initialized, which for a defaulted default constructor means they must | |
3296 | be of a class type with a constexpr default constructor. */ | |
3297 | if (TREE_CODE (elttype) == ARRAY_TYPE) | |
3298 | /* We only do this at the lowest level. */; | |
3299 | else if (value_init) | |
3300 | { | |
dc5ca6c8 | 3301 | init = build_value_init (elttype, complain); |
2d76680f PC |
3302 | pre_init = true; |
3303 | } | |
3304 | else if (!init) | |
3305 | { | |
cd9cf97b | 3306 | releasing_vec argvec; |
2d76680f PC |
3307 | init = build_special_member_call (NULL_TREE, complete_ctor_identifier, |
3308 | &argvec, elttype, LOOKUP_NORMAL, | |
dc5ca6c8 | 3309 | complain); |
5dab8b11 | 3310 | init = build_aggr_init_expr (elttype, init); |
2d76680f PC |
3311 | pre_init = true; |
3312 | } | |
3313 | ||
74f8705e MP |
3314 | tree nelts = get_array_or_vector_nelts (ctx, atype, non_constant_p, |
3315 | overflow_p); | |
3316 | unsigned HOST_WIDE_INT max = tree_to_uhwi (nelts); | |
4784470a | 3317 | for (i = 0; i < max; ++i) |
2d76680f PC |
3318 | { |
3319 | tree idx = build_int_cst (size_type_node, i); | |
3320 | tree eltinit; | |
928af3bf | 3321 | bool reuse = false; |
3e605b20 JM |
3322 | constexpr_ctx new_ctx; |
3323 | init_subob_ctx (ctx, new_ctx, idx, pre_init ? init : elttype); | |
3324 | if (new_ctx.ctor != ctx->ctor) | |
3325 | CONSTRUCTOR_APPEND_ELT (*p, idx, new_ctx.ctor); | |
2d76680f PC |
3326 | if (TREE_CODE (elttype) == ARRAY_TYPE) |
3327 | { | |
3328 | /* A multidimensional array; recurse. */ | |
3329 | if (value_init || init == NULL_TREE) | |
928af3bf JJ |
3330 | { |
3331 | eltinit = NULL_TREE; | |
3332 | reuse = i == 0; | |
3333 | } | |
2d76680f | 3334 | else |
dc5ca6c8 | 3335 | eltinit = cp_build_array_ref (input_location, init, idx, complain); |
3e605b20 | 3336 | eltinit = cxx_eval_vec_init_1 (&new_ctx, elttype, eltinit, value_init, |
92a596e8 | 3337 | lval, |
2d76680f PC |
3338 | non_constant_p, overflow_p); |
3339 | } | |
3340 | else if (pre_init) | |
3341 | { | |
3342 | /* Initializing an element using value or default initialization | |
3343 | we just pre-built above. */ | |
3ee378fb JM |
3344 | if (init == void_node) |
3345 | /* Trivial default-init, don't do anything to the CONSTRUCTOR. */ | |
3346 | return ctx->ctor; | |
928af3bf JJ |
3347 | eltinit = cxx_eval_constant_expression (&new_ctx, init, lval, |
3348 | non_constant_p, overflow_p); | |
3349 | reuse = i == 0; | |
2d76680f PC |
3350 | } |
3351 | else | |
3352 | { | |
3353 | /* Copying an element. */ | |
3354 | gcc_assert (same_type_ignoring_top_level_qualifiers_p | |
3355 | (atype, TREE_TYPE (init))); | |
dc5ca6c8 | 3356 | eltinit = cp_build_array_ref (input_location, init, idx, complain); |
72b3e203 | 3357 | if (!lvalue_p (init)) |
2d76680f | 3358 | eltinit = move (eltinit); |
dc5ca6c8 | 3359 | eltinit = force_rvalue (eltinit, complain); |
c2236b9b JJ |
3360 | eltinit = cxx_eval_constant_expression (&new_ctx, eltinit, lval, |
3361 | non_constant_p, overflow_p); | |
2d76680f | 3362 | } |
2b3ab879 | 3363 | if (*non_constant_p && !ctx->quiet) |
3e605b20 JM |
3364 | break; |
3365 | if (new_ctx.ctor != ctx->ctor) | |
3366 | { | |
3367 | /* We appended this element above; update the value. */ | |
3368 | gcc_assert ((*p)->last().index == idx); | |
3369 | (*p)->last().value = eltinit; | |
3370 | } | |
3371 | else | |
3372 | CONSTRUCTOR_APPEND_ELT (*p, idx, eltinit); | |
928af3bf | 3373 | /* Reuse the result of cxx_eval_constant_expression call |
c2236b9b JJ |
3374 | from the first iteration to all others if it is a constant |
3375 | initializer that doesn't require relocations. */ | |
928af3bf JJ |
3376 | if (reuse |
3377 | && max > 1 | |
c2236b9b JJ |
3378 | && (eltinit == NULL_TREE |
3379 | || (initializer_constant_valid_p (eltinit, TREE_TYPE (eltinit)) | |
3380 | == null_pointer_node))) | |
928af3bf JJ |
3381 | { |
3382 | if (new_ctx.ctor != ctx->ctor) | |
3383 | eltinit = new_ctx.ctor; | |
1e027956 RB |
3384 | tree range = build2 (RANGE_EXPR, size_type_node, |
3385 | build_int_cst (size_type_node, 1), | |
3386 | build_int_cst (size_type_node, max - 1)); | |
3387 | CONSTRUCTOR_APPEND_ELT (*p, range, unshare_constructor (eltinit)); | |
928af3bf JJ |
3388 | break; |
3389 | } | |
1e027956 RB |
3390 | else if (i == 0) |
3391 | vec_safe_reserve (*p, max); | |
2d76680f PC |
3392 | } |
3393 | ||
3394 | if (!*non_constant_p) | |
3395 | { | |
3e605b20 | 3396 | init = ctx->ctor; |
e8c48716 | 3397 | CONSTRUCTOR_NO_CLEARING (init) = false; |
2d76680f | 3398 | } |
2d76680f PC |
3399 | return init; |
3400 | } | |
3401 | ||
3402 | static tree | |
3e605b20 | 3403 | cxx_eval_vec_init (const constexpr_ctx *ctx, tree t, |
92a596e8 | 3404 | bool lval, |
2d76680f PC |
3405 | bool *non_constant_p, bool *overflow_p) |
3406 | { | |
3407 | tree atype = TREE_TYPE (t); | |
3408 | tree init = VEC_INIT_EXPR_INIT (t); | |
3e605b20 | 3409 | tree r = cxx_eval_vec_init_1 (ctx, atype, init, |
2d76680f | 3410 | VEC_INIT_EXPR_VALUE_INIT (t), |
92a596e8 | 3411 | lval, non_constant_p, overflow_p); |
2d76680f PC |
3412 | if (*non_constant_p) |
3413 | return t; | |
3414 | else | |
3415 | return r; | |
3416 | } | |
3417 | ||
e4511ca2 JM |
3418 | /* Like same_type_ignoring_top_level_qualifiers_p, but also handle the case |
3419 | where the desired type is an array of unknown bounds because the variable | |
3420 | has had its bounds deduced since the wrapping expression was created. */ | |
3421 | ||
3422 | static bool | |
3423 | same_type_ignoring_tlq_and_bounds_p (tree type1, tree type2) | |
3424 | { | |
3425 | while (TREE_CODE (type1) == ARRAY_TYPE | |
3426 | && TREE_CODE (type2) == ARRAY_TYPE | |
3427 | && (!TYPE_DOMAIN (type1) || !TYPE_DOMAIN (type2))) | |
3428 | { | |
3429 | type1 = TREE_TYPE (type1); | |
3430 | type2 = TREE_TYPE (type2); | |
3431 | } | |
3432 | return same_type_ignoring_top_level_qualifiers_p (type1, type2); | |
3433 | } | |
3434 | ||
0fe2ae29 JJ |
3435 | /* Helper function for cxx_fold_indirect_ref_1, called recursively. */ |
3436 | ||
3437 | static tree | |
3438 | cxx_fold_indirect_ref_1 (location_t loc, tree type, tree op, | |
3439 | unsigned HOST_WIDE_INT off, bool *empty_base) | |
3440 | { | |
3441 | tree optype = TREE_TYPE (op); | |
3442 | unsigned HOST_WIDE_INT const_nunits; | |
3443 | if (off == 0) | |
3444 | { | |
3445 | if (similar_type_p (optype, type)) | |
3446 | return op; | |
3447 | /* Also handle conversion to an empty base class, which | |
3448 | is represented with a NOP_EXPR. */ | |
3449 | /* *(foo *)&complexfoo => __real__ complexfoo */ | |
3450 | else if (TREE_CODE (optype) == COMPLEX_TYPE | |
3451 | && similar_type_p (type, TREE_TYPE (optype))) | |
3452 | return build1_loc (loc, REALPART_EXPR, type, op); | |
3453 | } | |
3454 | /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */ | |
3455 | else if (TREE_CODE (optype) == COMPLEX_TYPE | |
3456 | && similar_type_p (type, TREE_TYPE (optype)) | |
3457 | && tree_to_uhwi (TYPE_SIZE_UNIT (type)) == off) | |
3458 | return build1_loc (loc, IMAGPART_EXPR, type, op); | |
3459 | if (is_empty_class (type) | |
3460 | && CLASS_TYPE_P (optype) | |
3461 | && DERIVED_FROM_P (type, optype)) | |
3462 | { | |
3463 | *empty_base = true; | |
3464 | return op; | |
3465 | } | |
3466 | /* ((foo*)&vectorfoo)[x] => BIT_FIELD_REF<vectorfoo,...> */ | |
3467 | else if (VECTOR_TYPE_P (optype) | |
3468 | && similar_type_p (type, TREE_TYPE (optype)) | |
3469 | && TYPE_VECTOR_SUBPARTS (optype).is_constant (&const_nunits)) | |
3470 | { | |
3471 | unsigned HOST_WIDE_INT part_width = tree_to_uhwi (TYPE_SIZE_UNIT (type)); | |
3472 | unsigned HOST_WIDE_INT max_offset = part_width * const_nunits; | |
3473 | if (off < max_offset && off % part_width == 0) | |
3474 | { | |
3475 | tree index = bitsize_int (off * BITS_PER_UNIT); | |
3476 | return build3_loc (loc, BIT_FIELD_REF, type, op, | |
3477 | TYPE_SIZE (type), index); | |
3478 | } | |
3479 | } | |
3480 | /* ((foo *)&fooarray)[x] => fooarray[x] */ | |
3481 | else if (TREE_CODE (optype) == ARRAY_TYPE | |
3482 | && tree_fits_uhwi_p (TYPE_SIZE_UNIT (TREE_TYPE (optype))) | |
3483 | && !integer_zerop (TYPE_SIZE_UNIT (TREE_TYPE (optype)))) | |
3484 | { | |
3485 | tree type_domain = TYPE_DOMAIN (optype); | |
3486 | tree min_val = size_zero_node; | |
3487 | if (type_domain && TYPE_MIN_VALUE (type_domain)) | |
3488 | min_val = TYPE_MIN_VALUE (type_domain); | |
3489 | unsigned HOST_WIDE_INT el_sz | |
3490 | = tree_to_uhwi (TYPE_SIZE_UNIT (TREE_TYPE (optype))); | |
3491 | unsigned HOST_WIDE_INT idx = off / el_sz; | |
3492 | unsigned HOST_WIDE_INT rem = off % el_sz; | |
3493 | if (tree_fits_uhwi_p (min_val)) | |
3494 | { | |
3495 | tree index = size_int (idx + tree_to_uhwi (min_val)); | |
3496 | op = build4_loc (loc, ARRAY_REF, TREE_TYPE (optype), op, index, | |
3497 | NULL_TREE, NULL_TREE); | |
3498 | return cxx_fold_indirect_ref_1 (loc, type, op, rem, | |
3499 | empty_base); | |
3500 | } | |
3501 | } | |
3502 | /* ((foo *)&struct_with_foo_field)[x] => COMPONENT_REF */ | |
3503 | else if (TREE_CODE (optype) == RECORD_TYPE) | |
3504 | { | |
3505 | for (tree field = TYPE_FIELDS (optype); | |
3506 | field; field = DECL_CHAIN (field)) | |
3507 | if (TREE_CODE (field) == FIELD_DECL | |
3508 | && TREE_TYPE (field) != error_mark_node | |
3509 | && tree_fits_uhwi_p (TYPE_SIZE_UNIT (TREE_TYPE (field)))) | |
3510 | { | |
3511 | tree pos = byte_position (field); | |
3512 | if (!tree_fits_uhwi_p (pos)) | |
3513 | continue; | |
3514 | unsigned HOST_WIDE_INT upos = tree_to_uhwi (pos); | |
3515 | unsigned el_sz | |
3516 | = tree_to_uhwi (TYPE_SIZE_UNIT (TREE_TYPE (field))); | |
3517 | if (upos <= off && off < upos + el_sz) | |
3518 | { | |
3519 | tree cop = build3 (COMPONENT_REF, TREE_TYPE (field), | |
3520 | op, field, NULL_TREE); | |
3521 | if (tree ret = cxx_fold_indirect_ref_1 (loc, type, cop, | |
3522 | off - upos, | |
3523 | empty_base)) | |
3524 | return ret; | |
3525 | } | |
3526 | } | |
3527 | } | |
3528 | ||
3529 | return NULL_TREE; | |
3530 | } | |
3531 | ||
2d76680f PC |
3532 | /* A less strict version of fold_indirect_ref_1, which requires cv-quals to |
3533 | match. We want to be less strict for simple *& folding; if we have a | |
3534 | non-const temporary that we access through a const pointer, that should | |
3535 | work. We handle this here rather than change fold_indirect_ref_1 | |
3536 | because we're dealing with things like ADDR_EXPR of INTEGER_CST which | |
3537 | don't really make sense outside of constant expression evaluation. Also | |
3538 | we want to allow folding to COMPONENT_REF, which could cause trouble | |
0fe2ae29 | 3539 | with TBAA in fold_indirect_ref_1. */ |
2d76680f PC |
3540 | |
3541 | static tree | |
3542 | cxx_fold_indirect_ref (location_t loc, tree type, tree op0, bool *empty_base) | |
3543 | { | |
ebe4bf41 MP |
3544 | tree sub = op0; |
3545 | tree subtype; | |
3546 | poly_uint64 const_op01; | |
2d76680f | 3547 | |
2d76680f PC |
3548 | STRIP_NOPS (sub); |
3549 | subtype = TREE_TYPE (sub); | |
71a93b08 | 3550 | if (!INDIRECT_TYPE_P (subtype)) |
2d76680f PC |
3551 | return NULL_TREE; |
3552 | ||
3553 | if (TREE_CODE (sub) == ADDR_EXPR) | |
3554 | { | |
3555 | tree op = TREE_OPERAND (sub, 0); | |
3556 | tree optype = TREE_TYPE (op); | |
3557 | ||
3558 | /* *&CONST_DECL -> to the value of the const decl. */ | |
3559 | if (TREE_CODE (op) == CONST_DECL) | |
3560 | return DECL_INITIAL (op); | |
3561 | /* *&p => p; make sure to handle *&"str"[cst] here. */ | |
1a120ec1 | 3562 | if (similar_type_p (optype, type)) |
2d76680f PC |
3563 | { |
3564 | tree fop = fold_read_from_constant_string (op); | |
3565 | if (fop) | |
3566 | return fop; | |
3567 | else | |
3568 | return op; | |
3569 | } | |
0fe2ae29 JJ |
3570 | else |
3571 | return cxx_fold_indirect_ref_1 (loc, type, op, 0, empty_base); | |
2d76680f PC |
3572 | } |
3573 | else if (TREE_CODE (sub) == POINTER_PLUS_EXPR | |
0fe2ae29 | 3574 | && tree_fits_uhwi_p (TREE_OPERAND (sub, 1))) |
2d76680f PC |
3575 | { |
3576 | tree op00 = TREE_OPERAND (sub, 0); | |
3577 | tree op01 = TREE_OPERAND (sub, 1); | |
3578 | ||
3579 | STRIP_NOPS (op00); | |
3580 | if (TREE_CODE (op00) == ADDR_EXPR) | |
0fe2ae29 JJ |
3581 | return cxx_fold_indirect_ref_1 (loc, type, TREE_OPERAND (op00, 0), |
3582 | tree_to_uhwi (op01), empty_base); | |
2d76680f PC |
3583 | } |
3584 | /* *(foo *)fooarrptr => (*fooarrptr)[0] */ | |
3585 | else if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE | |
1a120ec1 | 3586 | && similar_type_p (type, TREE_TYPE (TREE_TYPE (subtype)))) |
2d76680f PC |
3587 | { |
3588 | tree type_domain; | |
3589 | tree min_val = size_zero_node; | |
ebe4bf41 MP |
3590 | tree newsub |
3591 | = cxx_fold_indirect_ref (loc, TREE_TYPE (subtype), sub, NULL); | |
2d76680f PC |
3592 | if (newsub) |
3593 | sub = newsub; | |
3594 | else | |
3595 | sub = build1_loc (loc, INDIRECT_REF, TREE_TYPE (subtype), sub); | |
3596 | type_domain = TYPE_DOMAIN (TREE_TYPE (sub)); | |
3597 | if (type_domain && TYPE_MIN_VALUE (type_domain)) | |
3598 | min_val = TYPE_MIN_VALUE (type_domain); | |
3599 | return build4_loc (loc, ARRAY_REF, type, sub, min_val, NULL_TREE, | |
3600 | NULL_TREE); | |
3601 | } | |
3602 | ||
3603 | return NULL_TREE; | |
3604 | } | |
3605 | ||
3606 | static tree | |
3e605b20 | 3607 | cxx_eval_indirect_ref (const constexpr_ctx *ctx, tree t, |
92a596e8 | 3608 | bool lval, |
2d76680f PC |
3609 | bool *non_constant_p, bool *overflow_p) |
3610 | { | |
3611 | tree orig_op0 = TREE_OPERAND (t, 0); | |
2d76680f | 3612 | bool empty_base = false; |
2d76680f | 3613 | |
cda0a029 JM |
3614 | /* We can handle a MEM_REF like an INDIRECT_REF, if MEM_REF's second |
3615 | operand is an integer-zero. Otherwise reject the MEM_REF for now. */ | |
3616 | ||
3617 | if (TREE_CODE (t) == MEM_REF | |
3618 | && (!TREE_OPERAND (t, 1) || !integer_zerop (TREE_OPERAND (t, 1)))) | |
3619 | { | |
3620 | gcc_assert (ctx->quiet); | |
3621 | *non_constant_p = true; | |
3622 | return t; | |
3623 | } | |
3624 | ||
255a48d6 JM |
3625 | /* First try to simplify it directly. */ |
3626 | tree r = cxx_fold_indirect_ref (EXPR_LOCATION (t), TREE_TYPE (t), orig_op0, | |
3627 | &empty_base); | |
3628 | if (!r) | |
2d76680f | 3629 | { |
255a48d6 JM |
3630 | /* If that didn't work, evaluate the operand first. */ |
3631 | tree op0 = cxx_eval_constant_expression (ctx, orig_op0, | |
3632 | /*lval*/false, non_constant_p, | |
3633 | overflow_p); | |
3634 | /* Don't VERIFY_CONSTANT here. */ | |
3635 | if (*non_constant_p) | |
3636 | return t; | |
3637 | ||
8bada5cd MS |
3638 | if (!lval && integer_zerop (op0)) |
3639 | { | |
3640 | if (!ctx->quiet) | |
3641 | error ("dereferencing a null pointer"); | |
3642 | *non_constant_p = true; | |
3643 | return t; | |
3644 | } | |
3645 | ||
255a48d6 JM |
3646 | r = cxx_fold_indirect_ref (EXPR_LOCATION (t), TREE_TYPE (t), op0, |
3647 | &empty_base); | |
3648 | if (r == NULL_TREE) | |
2d76680f PC |
3649 | { |
3650 | /* We couldn't fold to a constant value. Make sure it's not | |
3651 | something we should have been able to fold. */ | |
255a48d6 JM |
3652 | tree sub = op0; |
3653 | STRIP_NOPS (sub); | |
3654 | if (TREE_CODE (sub) == ADDR_EXPR) | |
3655 | { | |
1a120ec1 | 3656 | gcc_assert (!similar_type_p |
255a48d6 JM |
3657 | (TREE_TYPE (TREE_TYPE (sub)), TREE_TYPE (t))); |
3658 | /* DR 1188 says we don't have to deal with this. */ | |
3659 | if (!ctx->quiet) | |
1a120ec1 JM |
3660 | error_at (cp_expr_loc_or_input_loc (t), |
3661 | "accessing value of %qE through a %qT glvalue in a " | |
3662 | "constant expression", build_fold_indirect_ref (sub), | |
3663 | TREE_TYPE (t)); | |
255a48d6 JM |
3664 | *non_constant_p = true; |
3665 | return t; | |
3666 | } | |
3667 | ||
3668 | if (lval && op0 != orig_op0) | |
3669 | return build1 (INDIRECT_REF, TREE_TYPE (t), op0); | |
3670 | if (!lval) | |
3671 | VERIFY_CONSTANT (t); | |
2d76680f PC |
3672 | return t; |
3673 | } | |
3674 | } | |
3675 | ||
255a48d6 JM |
3676 | r = cxx_eval_constant_expression (ctx, r, |
3677 | lval, non_constant_p, overflow_p); | |
3678 | if (*non_constant_p) | |
3679 | return t; | |
3680 | ||
125db6a1 | 3681 | /* If we're pulling out the value of an empty base, just return an empty |
2d76680f | 3682 | CONSTRUCTOR. */ |
92a596e8 | 3683 | if (empty_base && !lval) |
2d76680f | 3684 | { |
2d76680f PC |
3685 | r = build_constructor (TREE_TYPE (t), NULL); |
3686 | TREE_CONSTANT (r) = true; | |
3687 | } | |
3688 | ||
2d76680f PC |
3689 | return r; |
3690 | } | |
3691 | ||
3692 | /* Complain about R, a VAR_DECL, not being usable in a constant expression. | |
3693 | Shared between potential_constant_expression and | |
3694 | cxx_eval_constant_expression. */ | |
3695 | ||
3696 | static void | |
3697 | non_const_var_error (tree r) | |
3698 | { | |
8e007055 | 3699 | auto_diagnostic_group d; |
2d76680f | 3700 | tree type = TREE_TYPE (r); |
8e007055 JJ |
3701 | if (DECL_NAME (r) == heap_uninit_identifier |
3702 | || DECL_NAME (r) == heap_identifier) | |
3703 | { | |
3704 | error ("the content of uninitialized storage is not usable " | |
3705 | "in a constant expression"); | |
3706 | inform (DECL_SOURCE_LOCATION (r), "allocated here"); | |
3707 | return; | |
3708 | } | |
3709 | if (DECL_NAME (r) == heap_deleted_identifier) | |
3710 | { | |
3711 | error ("use of allocated storage after deallocation in a " | |
3712 | "constant expression"); | |
3713 | inform (DECL_SOURCE_LOCATION (r), "allocated here"); | |
3714 | return; | |
3715 | } | |
2d76680f PC |
3716 | error ("the value of %qD is not usable in a constant " |
3717 | "expression", r); | |
3718 | /* Avoid error cascade. */ | |
3719 | if (DECL_INITIAL (r) == error_mark_node) | |
3720 | return; | |
3721 | if (DECL_DECLARED_CONSTEXPR_P (r)) | |
3722 | inform (DECL_SOURCE_LOCATION (r), | |
3723 | "%qD used in its own initializer", r); | |
3724 | else if (INTEGRAL_OR_ENUMERATION_TYPE_P (type)) | |
3725 | { | |
3726 | if (!CP_TYPE_CONST_P (type)) | |
3727 | inform (DECL_SOURCE_LOCATION (r), | |
3728 | "%q#D is not const", r); | |
3729 | else if (CP_TYPE_VOLATILE_P (type)) | |
3730 | inform (DECL_SOURCE_LOCATION (r), | |
3731 | "%q#D is volatile", r); | |
3732 | else if (!DECL_INITIAL (r) | |
a3e2b438 PP |
3733 | || !TREE_CONSTANT (DECL_INITIAL (r)) |
3734 | || !DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r)) | |
2d76680f PC |
3735 | inform (DECL_SOURCE_LOCATION (r), |
3736 | "%qD was not initialized with a constant " | |
3737 | "expression", r); | |
3738 | else | |
3739 | gcc_unreachable (); | |
3740 | } | |
9f613f06 | 3741 | else if (TYPE_REF_P (type)) |
fd338b13 JM |
3742 | inform (DECL_SOURCE_LOCATION (r), |
3743 | "%qD was not initialized with a constant " | |
3744 | "expression", r); | |
2d76680f PC |
3745 | else |
3746 | { | |
3747 | if (cxx_dialect >= cxx11 && !DECL_DECLARED_CONSTEXPR_P (r)) | |
3748 | inform (DECL_SOURCE_LOCATION (r), | |
3749 | "%qD was not declared %<constexpr%>", r); | |
3750 | else | |
3751 | inform (DECL_SOURCE_LOCATION (r), | |
3752 | "%qD does not have integral or enumeration type", | |
3753 | r); | |
3754 | } | |
3755 | } | |
3756 | ||
3757 | /* Subroutine of cxx_eval_constant_expression. | |
3758 | Like cxx_eval_unary_expression, except for trinary expressions. */ | |
3759 | ||
3760 | static tree | |
3e605b20 | 3761 | cxx_eval_trinary_expression (const constexpr_ctx *ctx, tree t, |
92a596e8 | 3762 | bool lval, |
2d76680f PC |
3763 | bool *non_constant_p, bool *overflow_p) |
3764 | { | |
3765 | int i; | |
3766 | tree args[3]; | |
3767 | tree val; | |
3768 | ||
3769 | for (i = 0; i < 3; i++) | |
3770 | { | |
3e605b20 | 3771 | args[i] = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, i), |
92a596e8 | 3772 | lval, |
5a804683 | 3773 | non_constant_p, overflow_p); |
2d76680f PC |
3774 | VERIFY_CONSTANT (args[i]); |
3775 | } | |
3776 | ||
3777 | val = fold_ternary_loc (EXPR_LOCATION (t), TREE_CODE (t), TREE_TYPE (t), | |
3778 | args[0], args[1], args[2]); | |
3779 | if (val == NULL_TREE) | |
3780 | return t; | |
3781 | VERIFY_CONSTANT (val); | |
3782 | return val; | |
3783 | } | |
3784 | ||
98e5a19a JM |
3785 | /* True if T was declared in a function declared to be constexpr, and |
3786 | therefore potentially constant in C++14. */ | |
3787 | ||
2d76680f PC |
3788 | bool |
3789 | var_in_constexpr_fn (tree t) | |
3790 | { | |
3791 | tree ctx = DECL_CONTEXT (t); | |
98e5a19a | 3792 | return (ctx && TREE_CODE (ctx) == FUNCTION_DECL |
2d76680f PC |
3793 | && DECL_DECLARED_CONSTEXPR_P (ctx)); |
3794 | } | |
3795 | ||
98e5a19a JM |
3796 | /* True if T was declared in a function that might be constexpr: either a |
3797 | function that was declared constexpr, or a C++17 lambda op(). */ | |
3798 | ||
3799 | bool | |
3800 | var_in_maybe_constexpr_fn (tree t) | |
3801 | { | |
7b936140 | 3802 | if (cxx_dialect >= cxx17 |
98e5a19a JM |
3803 | && DECL_FUNCTION_SCOPE_P (t) |
3804 | && LAMBDA_FUNCTION_P (DECL_CONTEXT (t))) | |
3805 | return true; | |
3806 | return var_in_constexpr_fn (t); | |
3807 | } | |
3808 | ||
68d01920 JM |
3809 | /* We're assigning INIT to TARGET. In do_build_copy_constructor and |
3810 | build_over_call we implement trivial copy of a class with tail padding using | |
3811 | assignment of character arrays, which is valid in normal code, but not in | |
3812 | constexpr evaluation. We don't need to worry about clobbering tail padding | |
3813 | in constexpr evaluation, so strip the type punning. */ | |
3814 | ||
3815 | static void | |
3816 | maybe_simplify_trivial_copy (tree &target, tree &init) | |
3817 | { | |
3818 | if (TREE_CODE (target) == MEM_REF | |
3819 | && TREE_CODE (init) == MEM_REF | |
3820 | && TREE_TYPE (target) == TREE_TYPE (init) | |
3821 | && TREE_CODE (TREE_TYPE (target)) == ARRAY_TYPE | |
3822 | && TREE_TYPE (TREE_TYPE (target)) == unsigned_char_type_node) | |
3823 | { | |
3824 | target = build_fold_indirect_ref (TREE_OPERAND (target, 0)); | |
3825 | init = build_fold_indirect_ref (TREE_OPERAND (init, 0)); | |
3826 | } | |
3827 | } | |
3828 | ||
04e1749c MP |
3829 | /* Return true if we are modifying something that is const during constant |
3830 | expression evaluation. CODE is the code of the statement, OBJ is the | |
3831 | object in question, MUTABLE_P is true if one of the subobjects were | |
3832 | declared mutable. */ | |
3833 | ||
3834 | static bool | |
3835 | modifying_const_object_p (tree_code code, tree obj, bool mutable_p) | |
3836 | { | |
3837 | /* If this is initialization, there's no problem. */ | |
3838 | if (code != MODIFY_EXPR) | |
3839 | return false; | |
3840 | ||
3841 | /* [basic.type.qualifier] "A const object is an object of type | |
3842 | const T or a non-mutable subobject of a const object." */ | |
3843 | if (mutable_p) | |
3844 | return false; | |
3845 | ||
3846 | return (TREE_READONLY (obj) || CP_TYPE_CONST_P (TREE_TYPE (obj))); | |
3847 | } | |
3848 | ||
60813a46 JM |
3849 | /* Evaluate an INIT_EXPR or MODIFY_EXPR. */ |
3850 | ||
3851 | static tree | |
3852 | cxx_eval_store_expression (const constexpr_ctx *ctx, tree t, | |
92a596e8 | 3853 | bool lval, |
60813a46 JM |
3854 | bool *non_constant_p, bool *overflow_p) |
3855 | { | |
3856 | constexpr_ctx new_ctx = *ctx; | |
3857 | ||
58cc255c JM |
3858 | tree init = TREE_OPERAND (t, 1); |
3859 | if (TREE_CLOBBER_P (init)) | |
3860 | /* Just ignore clobbers. */ | |
3861 | return void_node; | |
3862 | ||
60813a46 JM |
3863 | /* First we figure out where we're storing to. */ |
3864 | tree target = TREE_OPERAND (t, 0); | |
68d01920 JM |
3865 | |
3866 | maybe_simplify_trivial_copy (target, init); | |
3867 | ||
3f8e2835 | 3868 | tree type = TREE_TYPE (target); |
e8b3c1bc JM |
3869 | bool preeval = SCALAR_TYPE_P (type) || TREE_CODE (t) == MODIFY_EXPR; |
3870 | if (preeval) | |
3871 | { | |
3872 | /* Evaluate the value to be stored without knowing what object it will be | |
3873 | stored in, so that any side-effects happen first. */ | |
3874 | if (!SCALAR_TYPE_P (type)) | |
3875 | new_ctx.ctor = new_ctx.object = NULL_TREE; | |
3876 | init = cxx_eval_constant_expression (&new_ctx, init, false, | |
3877 | non_constant_p, overflow_p); | |
3878 | if (*non_constant_p) | |
3879 | return t; | |
3880 | } | |
60813a46 | 3881 | |
d0aa42d2 JM |
3882 | bool evaluated = false; |
3883 | if (lval) | |
3f8e2835 | 3884 | { |
d0aa42d2 JM |
3885 | /* If we want to return a reference to the target, we need to evaluate it |
3886 | as a whole; otherwise, only evaluate the innermost piece to avoid | |
3887 | building up unnecessary *_REFs. */ | |
3888 | target = cxx_eval_constant_expression (ctx, target, true, | |
3889 | non_constant_p, overflow_p); | |
3890 | evaluated = true; | |
3891 | if (*non_constant_p) | |
3892 | return t; | |
3f8e2835 JM |
3893 | } |
3894 | ||
043666e0 | 3895 | /* Find the underlying variable. */ |
cd9cf97b | 3896 | releasing_vec refs; |
60813a46 | 3897 | tree object = NULL_TREE; |
04e1749c MP |
3898 | /* If we're modifying a const object, save it. */ |
3899 | tree const_object_being_modified = NULL_TREE; | |
3900 | bool mutable_p = false; | |
60813a46 JM |
3901 | for (tree probe = target; object == NULL_TREE; ) |
3902 | { | |
3903 | switch (TREE_CODE (probe)) | |
3904 | { | |
3905 | case BIT_FIELD_REF: | |
3906 | case COMPONENT_REF: | |
3907 | case ARRAY_REF: | |
043666e0 JM |
3908 | { |
3909 | tree ob = TREE_OPERAND (probe, 0); | |
3910 | tree elt = TREE_OPERAND (probe, 1); | |
7d349dd8 | 3911 | if (TREE_CODE (elt) == FIELD_DECL && DECL_MUTABLE_P (elt)) |
04e1749c MP |
3912 | mutable_p = true; |
3913 | if (evaluated | |
3914 | && modifying_const_object_p (TREE_CODE (t), probe, mutable_p) | |
3915 | && const_object_being_modified == NULL_TREE) | |
3916 | const_object_being_modified = probe; | |
043666e0 JM |
3917 | if (TREE_CODE (probe) == ARRAY_REF) |
3918 | { | |
3919 | elt = eval_and_check_array_index (ctx, probe, false, | |
3920 | non_constant_p, overflow_p); | |
3921 | if (*non_constant_p) | |
3922 | return t; | |
3923 | } | |
3924 | vec_safe_push (refs, elt); | |
3925 | vec_safe_push (refs, TREE_TYPE (probe)); | |
3926 | probe = ob; | |
3927 | } | |
60813a46 JM |
3928 | break; |
3929 | ||
3930 | default: | |
d0aa42d2 JM |
3931 | if (evaluated) |
3932 | object = probe; | |
3933 | else | |
3934 | { | |
3935 | probe = cxx_eval_constant_expression (ctx, probe, true, | |
3936 | non_constant_p, overflow_p); | |
3937 | evaluated = true; | |
3938 | if (*non_constant_p) | |
3939 | return t; | |
3940 | } | |
3941 | break; | |
60813a46 JM |
3942 | } |
3943 | } | |
3944 | ||
04e1749c MP |
3945 | if (modifying_const_object_p (TREE_CODE (t), object, mutable_p) |
3946 | && const_object_being_modified == NULL_TREE) | |
3947 | const_object_being_modified = object; | |
3948 | ||
60813a46 JM |
3949 | /* And then find/build up our initializer for the path to the subobject |
3950 | we're initializing. */ | |
a1408b7e | 3951 | tree *valp; |
1e163090 JM |
3952 | if (object == ctx->object && VAR_P (object) |
3953 | && DECL_NAME (object) && ctx->call == NULL) | |
3954 | /* The variable we're building up an aggregate initializer for is outside | |
3955 | the constant-expression, so don't evaluate the store. We check | |
3956 | DECL_NAME to handle TARGET_EXPR temporaries, which are fair game. */ | |
3957 | valp = NULL; | |
3958 | else if (DECL_P (object)) | |
8e007055 | 3959 | valp = ctx->global->values.get (object); |
a1408b7e JM |
3960 | else |
3961 | valp = NULL; | |
60813a46 JM |
3962 | if (!valp) |
3963 | { | |
3964 | /* A constant-expression cannot modify objects from outside the | |
3965 | constant-expression. */ | |
2b3ab879 | 3966 | if (!ctx->quiet) |
64d6d399 | 3967 | error ("modification of %qE is not a constant expression", object); |
60813a46 JM |
3968 | *non_constant_p = true; |
3969 | return t; | |
3970 | } | |
3f8e2835 | 3971 | type = TREE_TYPE (object); |
c75ce530 | 3972 | bool no_zero_init = true; |
2d63bc39 | 3973 | |
cd9cf97b | 3974 | releasing_vec ctors; |
276a52d5 | 3975 | while (!refs->is_empty ()) |
60813a46 JM |
3976 | { |
3977 | if (*valp == NULL_TREE) | |
3978 | { | |
3979 | *valp = build_constructor (type, NULL); | |
e8c48716 | 3980 | CONSTRUCTOR_NO_CLEARING (*valp) = no_zero_init; |
60813a46 | 3981 | } |
d6b46fca NS |
3982 | else if (TREE_CODE (*valp) == STRING_CST) |
3983 | { | |
3984 | /* An array was initialized with a string constant, and now | |
3985 | we're writing into one of its elements. Explode the | |
3986 | single initialization into a set of element | |
3987 | initializations. */ | |
3988 | gcc_assert (TREE_CODE (type) == ARRAY_TYPE); | |
3989 | ||
3990 | tree string = *valp; | |
3991 | tree elt_type = TREE_TYPE (type); | |
3992 | unsigned chars_per_elt = (TYPE_PRECISION (elt_type) | |
3993 | / TYPE_PRECISION (char_type_node)); | |
3994 | unsigned num_elts = TREE_STRING_LENGTH (string) / chars_per_elt; | |
3995 | tree ary_ctor = build_constructor (type, NULL); | |
3996 | ||
3997 | vec_safe_reserve (CONSTRUCTOR_ELTS (ary_ctor), num_elts); | |
3998 | for (unsigned ix = 0; ix != num_elts; ix++) | |
3999 | { | |
4000 | constructor_elt elt = | |
4001 | { | |
4002 | build_int_cst (size_type_node, ix), | |
4003 | extract_string_elt (string, chars_per_elt, ix) | |
4004 | }; | |
4005 | CONSTRUCTOR_ELTS (ary_ctor)->quick_push (elt); | |
4006 | } | |
4007 | ||
4008 | *valp = ary_ctor; | |
4009 | } | |
4010 | ||
c75ce530 JM |
4011 | /* If the value of object is already zero-initialized, any new ctors for |
4012 | subobjects will also be zero-initialized. */ | |
e8c48716 | 4013 | no_zero_init = CONSTRUCTOR_NO_CLEARING (*valp); |
60813a46 | 4014 | |
2d63bc39 JM |
4015 | vec_safe_push (ctors, *valp); |
4016 | ||
ceaaf873 | 4017 | enum tree_code code = TREE_CODE (type); |
60813a46 | 4018 | type = refs->pop(); |
ceaaf873 | 4019 | tree index = refs->pop(); |
60813a46 | 4020 | |
60813a46 | 4021 | constructor_elt *cep = NULL; |
ceaaf873 JM |
4022 | if (code == ARRAY_TYPE) |
4023 | { | |
4024 | HOST_WIDE_INT i | |
4025 | = find_array_ctor_elt (*valp, index, /*insert*/true); | |
4026 | gcc_assert (i >= 0); | |
4027 | cep = CONSTRUCTOR_ELT (*valp, i); | |
4028 | gcc_assert (TREE_CODE (cep->index) != RANGE_EXPR); | |
4029 | } | |
4030 | else | |
4031 | { | |
4032 | gcc_assert (TREE_CODE (index) == FIELD_DECL); | |
88504f34 NS |
4033 | |
4034 | /* We must keep the CONSTRUCTOR's ELTS in FIELD order. | |
4035 | Usually we meet initializers in that order, but it is | |
4036 | possible for base types to be placed not in program | |
4037 | order. */ | |
4038 | tree fields = TYPE_FIELDS (DECL_CONTEXT (index)); | |
4039 | unsigned HOST_WIDE_INT idx; | |
4040 | ||
5c97093b JM |
4041 | if (code == UNION_TYPE && CONSTRUCTOR_NELTS (*valp) |
4042 | && CONSTRUCTOR_ELT (*valp, 0)->index != index) | |
ed4ec9ce JJ |
4043 | { |
4044 | if (cxx_dialect < cxx2a) | |
4045 | { | |
4046 | if (!ctx->quiet) | |
f9d0ca40 | 4047 | error_at (cp_expr_loc_or_input_loc (t), |
ed4ec9ce JJ |
4048 | "change of the active member of a union " |
4049 | "from %qD to %qD", | |
4050 | CONSTRUCTOR_ELT (*valp, 0)->index, | |
4051 | index); | |
4052 | *non_constant_p = true; | |
4053 | } | |
4054 | /* Changing active member. */ | |
4055 | vec_safe_truncate (CONSTRUCTOR_ELTS (*valp), 0); | |
c7f7c313 | 4056 | no_zero_init = true; |
ed4ec9ce | 4057 | } |
5c97093b | 4058 | |
88504f34 | 4059 | for (idx = 0; |
ceaaf873 | 4060 | vec_safe_iterate (CONSTRUCTOR_ELTS (*valp), idx, &cep); |
88504f34 | 4061 | idx++, fields = DECL_CHAIN (fields)) |
ceaaf873 | 4062 | { |
88504f34 NS |
4063 | if (index == cep->index) |
4064 | goto found; | |
4065 | ||
4066 | /* The field we're initializing must be on the field | |
4067 | list. Look to see if it is present before the | |
4068 | field the current ELT initializes. */ | |
4069 | for (; fields != cep->index; fields = DECL_CHAIN (fields)) | |
4070 | if (index == fields) | |
4071 | goto insert; | |
ceaaf873 | 4072 | } |
88504f34 NS |
4073 | |
4074 | /* We fell off the end of the CONSTRUCTOR, so insert a new | |
4075 | entry at the end. */ | |
4076 | insert: | |
4077 | { | |
4078 | constructor_elt ce = { index, NULL_TREE }; | |
4079 | ||
4080 | vec_safe_insert (CONSTRUCTOR_ELTS (*valp), idx, ce); | |
4081 | cep = CONSTRUCTOR_ELT (*valp, idx); | |
4082 | } | |
4083 | found:; | |
ceaaf873 | 4084 | } |
60813a46 JM |
4085 | valp = &cep->value; |
4086 | } | |
60813a46 | 4087 | |
04e1749c MP |
4088 | /* Detect modifying a constant object in constexpr evaluation. |
4089 | We have found a const object that is being modified. Figure out | |
4090 | if we need to issue an error. Consider | |
4091 | ||
4092 | struct A { | |
4093 | int n; | |
4094 | constexpr A() : n(1) { n = 2; } // #1 | |
4095 | }; | |
4096 | struct B { | |
4097 | const A a; | |
4098 | constexpr B() { a.n = 3; } // #2 | |
4099 | }; | |
4100 | constexpr B b{}; | |
4101 | ||
4102 | #1 is OK, since we're modifying an object under construction, but | |
4103 | #2 is wrong, since "a" is const and has been fully constructed. | |
4104 | To track it, we use the TREE_READONLY bit in the object's CONSTRUCTOR | |
4105 | which means that the object is read-only. For the example above, the | |
4106 | *ctors stack at the point of #2 will look like: | |
4107 | ||
4108 | ctors[0] = {.a={.n=2}} TREE_READONLY = 0 | |
4109 | ctors[1] = {.n=2} TREE_READONLY = 1 | |
4110 | ||
4111 | and we're modifying "b.a", so we search the stack and see if the | |
4112 | constructor for "b.a" has already run. */ | |
4113 | if (const_object_being_modified) | |
4114 | { | |
4115 | bool fail = false; | |
276a52d5 JJ |
4116 | tree const_objtype |
4117 | = strip_array_types (TREE_TYPE (const_object_being_modified)); | |
4118 | if (!CLASS_TYPE_P (const_objtype)) | |
04e1749c MP |
4119 | fail = true; |
4120 | else | |
4121 | { | |
4122 | /* [class.ctor]p5 "A constructor can be invoked for a const, | |
4123 | volatile, or const volatile object. const and volatile | |
4124 | semantics are not applied on an object under construction. | |
4125 | They come into effect when the constructor for the most | |
4126 | derived object ends." */ | |
4127 | tree elt; | |
4128 | unsigned int i; | |
4129 | FOR_EACH_VEC_ELT (*ctors, i, elt) | |
4130 | if (same_type_ignoring_top_level_qualifiers_p | |
4131 | (TREE_TYPE (const_object_being_modified), TREE_TYPE (elt))) | |
4132 | { | |
4133 | fail = TREE_READONLY (elt); | |
4134 | break; | |
4135 | } | |
4136 | } | |
4137 | if (fail) | |
4138 | { | |
4139 | if (!ctx->quiet) | |
4140 | modifying_const_object_error (t, const_object_being_modified); | |
4141 | *non_constant_p = true; | |
4142 | return t; | |
4143 | } | |
4144 | } | |
4145 | ||
e8b3c1bc | 4146 | if (!preeval) |
60813a46 JM |
4147 | { |
4148 | /* Create a new CONSTRUCTOR in case evaluation of the initializer | |
4149 | wants to modify it. */ | |
acb2970c | 4150 | if (*valp == NULL_TREE) |
73a84269 | 4151 | { |
664beaf2 | 4152 | *valp = build_constructor (type, NULL); |
e8c48716 | 4153 | CONSTRUCTOR_NO_CLEARING (*valp) = no_zero_init; |
73a84269 | 4154 | } |
664beaf2 | 4155 | new_ctx.ctor = *valp; |
60813a46 | 4156 | new_ctx.object = target; |
e8b3c1bc JM |
4157 | init = cxx_eval_constant_expression (&new_ctx, init, false, |
4158 | non_constant_p, overflow_p); | |
d0aa42d2 | 4159 | if (ctors->is_empty()) |
e8b3c1bc | 4160 | /* The hash table might have moved since the get earlier. */ |
8e007055 | 4161 | valp = ctx->global->values.get (object); |
60813a46 JM |
4162 | } |
4163 | ||
7574c916 | 4164 | /* Don't share a CONSTRUCTOR that might be changed later. */ |
0146e25f | 4165 | init = unshare_constructor (init); |
d96e8407 | 4166 | |
e8b3c1bc JM |
4167 | if (*valp && TREE_CODE (*valp) == CONSTRUCTOR |
4168 | && TREE_CODE (init) == CONSTRUCTOR) | |
acb2970c | 4169 | { |
d96e8407 JM |
4170 | /* An outer ctx->ctor might be pointing to *valp, so replace |
4171 | its contents. */ | |
d0aa42d2 JM |
4172 | if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (init), |
4173 | TREE_TYPE (*valp))) | |
4174 | { | |
4175 | /* For initialization of an empty base, the original target will be | |
4176 | *(base*)this, evaluation of which resolves to the object | |
4177 | argument, which has the derived type rather than the base type. In | |
4178 | this situation, just evaluate the initializer and return, since | |
4179 | there's no actual data to store. */ | |
4180 | gcc_assert (is_empty_class (TREE_TYPE (init)) && !lval); | |
4181 | return init; | |
4182 | } | |
d96e8407 JM |
4183 | CONSTRUCTOR_ELTS (*valp) = CONSTRUCTOR_ELTS (init); |
4184 | TREE_CONSTANT (*valp) = TREE_CONSTANT (init); | |
4185 | TREE_SIDE_EFFECTS (*valp) = TREE_SIDE_EFFECTS (init); | |
e8c48716 JM |
4186 | CONSTRUCTOR_NO_CLEARING (*valp) |
4187 | = CONSTRUCTOR_NO_CLEARING (init); | |
acb2970c | 4188 | } |
60813a46 | 4189 | else |
d96e8407 | 4190 | *valp = init; |
2d63bc39 | 4191 | |
d96e8407 JM |
4192 | /* Update TREE_CONSTANT and TREE_SIDE_EFFECTS on enclosing |
4193 | CONSTRUCTORs, if any. */ | |
4194 | tree elt; | |
4195 | unsigned i; | |
4196 | bool c = TREE_CONSTANT (init); | |
4197 | bool s = TREE_SIDE_EFFECTS (init); | |
4198 | if (!c || s) | |
cd9cf97b | 4199 | FOR_EACH_VEC_ELT (*ctors, i, elt) |
d96e8407 JM |
4200 | { |
4201 | if (!c) | |
4202 | TREE_CONSTANT (elt) = false; | |
4203 | if (s) | |
4204 | TREE_SIDE_EFFECTS (elt) = true; | |
4205 | } | |
60813a46 JM |
4206 | |
4207 | if (*non_constant_p) | |
4208 | return t; | |
92a596e8 | 4209 | else if (lval) |
60813a46 JM |
4210 | return target; |
4211 | else | |
3bdf0a9b | 4212 | return init; |
60813a46 JM |
4213 | } |
4214 | ||
4215 | /* Evaluate a ++ or -- expression. */ | |
4216 | ||
4217 | static tree | |
4218 | cxx_eval_increment_expression (const constexpr_ctx *ctx, tree t, | |
92a596e8 | 4219 | bool lval, |
60813a46 JM |
4220 | bool *non_constant_p, bool *overflow_p) |
4221 | { | |
4222 | enum tree_code code = TREE_CODE (t); | |
4223 | tree type = TREE_TYPE (t); | |
4224 | tree op = TREE_OPERAND (t, 0); | |
4225 | tree offset = TREE_OPERAND (t, 1); | |
4226 | gcc_assert (TREE_CONSTANT (offset)); | |
4227 | ||
d85569f6 MP |
4228 | /* OFFSET is constant, but perhaps not constant enough. We need to |
4229 | e.g. bash FLOAT_EXPRs to REAL_CSTs. */ | |
4230 | offset = fold_simple (offset); | |
4231 | ||
60813a46 | 4232 | /* The operand as an lvalue. */ |
2b3ab879 | 4233 | op = cxx_eval_constant_expression (ctx, op, true, |
5a804683 | 4234 | non_constant_p, overflow_p); |
60813a46 JM |
4235 | |
4236 | /* The operand as an rvalue. */ | |
84dd815f JM |
4237 | tree val |
4238 | = cxx_eval_constant_expression (ctx, op, false, | |
4239 | non_constant_p, overflow_p); | |
caee690e JM |
4240 | /* Don't VERIFY_CONSTANT if this might be dealing with a pointer to |
4241 | a local array in a constexpr function. */ | |
71a93b08 | 4242 | bool ptr = INDIRECT_TYPE_P (TREE_TYPE (val)); |
caee690e JM |
4243 | if (!ptr) |
4244 | VERIFY_CONSTANT (val); | |
60813a46 JM |
4245 | |
4246 | /* The modified value. */ | |
4247 | bool inc = (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR); | |
ac2f8d26 | 4248 | tree mod; |
71a93b08 | 4249 | if (INDIRECT_TYPE_P (type)) |
ac2f8d26 JM |
4250 | { |
4251 | /* The middle end requires pointers to use POINTER_PLUS_EXPR. */ | |
4252 | offset = convert_to_ptrofftype (offset); | |
4253 | if (!inc) | |
4254 | offset = fold_build1 (NEGATE_EXPR, TREE_TYPE (offset), offset); | |
4255 | mod = fold_build2 (POINTER_PLUS_EXPR, type, val, offset); | |
4256 | } | |
4257 | else | |
4258 | mod = fold_build2 (inc ? PLUS_EXPR : MINUS_EXPR, type, val, offset); | |
caee690e JM |
4259 | if (!ptr) |
4260 | VERIFY_CONSTANT (mod); | |
60813a46 JM |
4261 | |
4262 | /* Storing the modified value. */ | |
04e1749c MP |
4263 | tree store = build2_loc (cp_expr_loc_or_loc (t, input_location), |
4264 | MODIFY_EXPR, type, op, mod); | |
2b3ab879 | 4265 | cxx_eval_constant_expression (ctx, store, |
5a804683 | 4266 | true, non_constant_p, overflow_p); |
ecdcd560 | 4267 | ggc_free (store); |
60813a46 JM |
4268 | |
4269 | /* And the value of the expression. */ | |
4270 | if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR) | |
4271 | { | |
4272 | /* Prefix ops are lvalues. */ | |
92a596e8 | 4273 | if (lval) |
60813a46 JM |
4274 | return op; |
4275 | else | |
4276 | /* But we optimize when the caller wants an rvalue. */ | |
4277 | return mod; | |
4278 | } | |
4279 | else | |
4280 | /* Postfix ops are rvalues. */ | |
4281 | return val; | |
4282 | } | |
4283 | ||
56632b27 JM |
4284 | /* Predicates for the meaning of *jump_target. */ |
4285 | ||
4286 | static bool | |
4287 | returns (tree *jump_target) | |
4288 | { | |
4289 | return *jump_target | |
d49318d9 PC |
4290 | && (TREE_CODE (*jump_target) == RETURN_EXPR |
4291 | || (TREE_CODE (*jump_target) == LABEL_DECL | |
4292 | && LABEL_DECL_CDTOR (*jump_target))); | |
56632b27 JM |
4293 | } |
4294 | ||
4295 | static bool | |
4296 | breaks (tree *jump_target) | |
4297 | { | |
4298 | return *jump_target | |
06ec22b7 JM |
4299 | && ((TREE_CODE (*jump_target) == LABEL_DECL |
4300 | && LABEL_DECL_BREAK (*jump_target)) | |
3075affd | 4301 | || TREE_CODE (*jump_target) == BREAK_STMT |
06ec22b7 | 4302 | || TREE_CODE (*jump_target) == EXIT_EXPR); |
56632b27 JM |
4303 | } |
4304 | ||
4305 | static bool | |
4306 | continues (tree *jump_target) | |
4307 | { | |
4308 | return *jump_target | |
3075affd JM |
4309 | && ((TREE_CODE (*jump_target) == LABEL_DECL |
4310 | && LABEL_DECL_CONTINUE (*jump_target)) | |
4311 | || TREE_CODE (*jump_target) == CONTINUE_STMT); | |
4312 | ||
56632b27 JM |
4313 | } |
4314 | ||
4315 | static bool | |
4316 | switches (tree *jump_target) | |
4317 | { | |
4318 | return *jump_target | |
4319 | && TREE_CODE (*jump_target) == INTEGER_CST; | |
4320 | } | |
4321 | ||
4322 | /* Subroutine of cxx_eval_statement_list. Determine whether the statement | |
4b390698 JJ |
4323 | STMT matches *jump_target. If we're looking for a case label and we see |
4324 | the default label, note it in ctx->css_state. */ | |
56632b27 JM |
4325 | |
4326 | static bool | |
4b390698 | 4327 | label_matches (const constexpr_ctx *ctx, tree *jump_target, tree stmt) |
56632b27 | 4328 | { |
56632b27 JM |
4329 | switch (TREE_CODE (*jump_target)) |
4330 | { | |
4331 | case LABEL_DECL: | |
4332 | if (TREE_CODE (stmt) == LABEL_EXPR | |
4333 | && LABEL_EXPR_LABEL (stmt) == *jump_target) | |
4334 | return true; | |
4335 | break; | |
4336 | ||
4337 | case INTEGER_CST: | |
4338 | if (TREE_CODE (stmt) == CASE_LABEL_EXPR) | |
4339 | { | |
4b390698 | 4340 | gcc_assert (ctx->css_state != NULL); |
56632b27 | 4341 | if (!CASE_LOW (stmt)) |
4b390698 JJ |
4342 | { |
4343 | /* default: should appear just once in a SWITCH_EXPR | |
4344 | body (excluding nested SWITCH_EXPR). */ | |
4345 | gcc_assert (*ctx->css_state != css_default_seen); | |
4346 | /* When evaluating SWITCH_EXPR body for the second time, | |
4347 | return true for the default: label. */ | |
4348 | if (*ctx->css_state == css_default_processing) | |
4349 | return true; | |
4350 | *ctx->css_state = css_default_seen; | |
4351 | } | |
385ed708 JJ |
4352 | else if (CASE_HIGH (stmt)) |
4353 | { | |
4354 | if (tree_int_cst_le (CASE_LOW (stmt), *jump_target) | |
4355 | && tree_int_cst_le (*jump_target, CASE_HIGH (stmt))) | |
4356 | return true; | |
4357 | } | |
56632b27 JM |
4358 | else if (tree_int_cst_equal (*jump_target, CASE_LOW (stmt))) |
4359 | return true; | |
4360 | } | |
4361 | break; | |
4362 | ||
43574e4f JJ |
4363 | case BREAK_STMT: |
4364 | case CONTINUE_STMT: | |
4365 | /* These two are handled directly in cxx_eval_loop_expr by testing | |
4366 | breaks (jump_target) or continues (jump_target). */ | |
4367 | break; | |
4368 | ||
56632b27 JM |
4369 | default: |
4370 | gcc_unreachable (); | |
4371 | } | |
4372 | return false; | |
4373 | } | |
4374 | ||
4375 | /* Evaluate a STATEMENT_LIST for side-effects. Handles various jump | |
4376 | semantics, for switch, break, continue, and return. */ | |
4377 | ||
4378 | static tree | |
4379 | cxx_eval_statement_list (const constexpr_ctx *ctx, tree t, | |
56632b27 JM |
4380 | bool *non_constant_p, bool *overflow_p, |
4381 | tree *jump_target) | |
4382 | { | |
4383 | tree_stmt_iterator i; | |
58611fb6 | 4384 | tree local_target; |
345edb37 JJ |
4385 | /* In a statement-expression we want to return the last value. |
4386 | For empty statement expression return void_node. */ | |
4387 | tree r = void_node; | |
58611fb6 JM |
4388 | if (!jump_target) |
4389 | { | |
4390 | local_target = NULL_TREE; | |
4391 | jump_target = &local_target; | |
4392 | } | |
56632b27 JM |
4393 | for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i)) |
4394 | { | |
56632b27 | 4395 | tree stmt = tsi_stmt (i); |
0250ba58 MP |
4396 | /* We've found a continue, so skip everything until we reach |
4397 | the label its jumping to. */ | |
4398 | if (continues (jump_target)) | |
4399 | { | |
4400 | if (label_matches (ctx, jump_target, stmt)) | |
4401 | /* Found it. */ | |
4402 | *jump_target = NULL_TREE; | |
4403 | else | |
4404 | continue; | |
4405 | } | |
6ef72c36 JJ |
4406 | if (TREE_CODE (stmt) == DEBUG_BEGIN_STMT) |
4407 | continue; | |
58611fb6 JM |
4408 | r = cxx_eval_constant_expression (ctx, stmt, false, |
4409 | non_constant_p, overflow_p, | |
4410 | jump_target); | |
56632b27 JM |
4411 | if (*non_constant_p) |
4412 | break; | |
4413 | if (returns (jump_target) || breaks (jump_target)) | |
4414 | break; | |
4415 | } | |
ce36ba09 JM |
4416 | if (*jump_target && jump_target == &local_target) |
4417 | { | |
4418 | /* We aren't communicating the jump to our caller, so give up. We don't | |
4419 | need to support evaluation of jumps out of statement-exprs. */ | |
4420 | if (!ctx->quiet) | |
f9d0ca40 | 4421 | error_at (cp_expr_loc_or_input_loc (r), |
ce36ba09 JM |
4422 | "statement is not a constant expression"); |
4423 | *non_constant_p = true; | |
4424 | } | |
58611fb6 | 4425 | return r; |
56632b27 JM |
4426 | } |
4427 | ||
4428 | /* Evaluate a LOOP_EXPR for side-effects. Handles break and return | |
4429 | semantics; continue semantics are covered by cxx_eval_statement_list. */ | |
4430 | ||
4431 | static tree | |
4432 | cxx_eval_loop_expr (const constexpr_ctx *ctx, tree t, | |
56632b27 JM |
4433 | bool *non_constant_p, bool *overflow_p, |
4434 | tree *jump_target) | |
4435 | { | |
39dce2b7 | 4436 | constexpr_ctx new_ctx = *ctx; |
8e007055 JJ |
4437 | tree local_target; |
4438 | if (!jump_target) | |
4439 | { | |
4440 | local_target = NULL_TREE; | |
4441 | jump_target = &local_target; | |
4442 | } | |
39dce2b7 | 4443 | |
43574e4f | 4444 | tree body, cond = NULL_TREE, expr = NULL_TREE; |
5ec2cd9f | 4445 | int count = 0; |
43574e4f JJ |
4446 | switch (TREE_CODE (t)) |
4447 | { | |
4448 | case LOOP_EXPR: | |
4449 | body = LOOP_EXPR_BODY (t); | |
4450 | break; | |
4451 | case DO_STMT: | |
4452 | body = DO_BODY (t); | |
4453 | cond = DO_COND (t); | |
4454 | break; | |
4455 | case WHILE_STMT: | |
4456 | body = WHILE_BODY (t); | |
4457 | cond = WHILE_COND (t); | |
4458 | count = -1; | |
4459 | break; | |
4460 | case FOR_STMT: | |
4461 | if (FOR_INIT_STMT (t)) | |
4462 | cxx_eval_constant_expression (ctx, FOR_INIT_STMT (t), /*lval*/false, | |
4463 | non_constant_p, overflow_p, jump_target); | |
4464 | if (*non_constant_p) | |
4465 | return NULL_TREE; | |
4466 | body = FOR_BODY (t); | |
4467 | cond = FOR_COND (t); | |
4468 | expr = FOR_EXPR (t); | |
4469 | count = -1; | |
4470 | break; | |
4471 | default: | |
4472 | gcc_unreachable (); | |
4473 | } | |
0ee28590 | 4474 | auto_vec<tree, 10> save_exprs; |
43574e4f | 4475 | new_ctx.save_exprs = &save_exprs; |
d259b234 | 4476 | do |
56632b27 | 4477 | { |
43574e4f JJ |
4478 | if (count != -1) |
4479 | { | |
4480 | if (body) | |
4481 | cxx_eval_constant_expression (&new_ctx, body, /*lval*/false, | |
4482 | non_constant_p, overflow_p, | |
4483 | jump_target); | |
4484 | if (breaks (jump_target)) | |
4485 | { | |
4486 | *jump_target = NULL_TREE; | |
4487 | break; | |
4488 | } | |
39dce2b7 | 4489 | |
43574e4f JJ |
4490 | if (TREE_CODE (t) != LOOP_EXPR && continues (jump_target)) |
4491 | *jump_target = NULL_TREE; | |
4492 | ||
4493 | if (expr) | |
4494 | cxx_eval_constant_expression (&new_ctx, expr, /*lval*/false, | |
4495 | non_constant_p, overflow_p, | |
4496 | jump_target); | |
4497 | } | |
4498 | ||
4499 | if (cond) | |
4500 | { | |
4501 | tree res | |
4502 | = cxx_eval_constant_expression (&new_ctx, cond, /*lval*/false, | |
4503 | non_constant_p, overflow_p, | |
4504 | jump_target); | |
4505 | if (res) | |
4506 | { | |
4507 | if (verify_constant (res, ctx->quiet, non_constant_p, | |
4508 | overflow_p)) | |
4509 | break; | |
4510 | if (integer_zerop (res)) | |
4511 | break; | |
4512 | } | |
4513 | else | |
4514 | gcc_assert (*jump_target); | |
4515 | } | |
39dce2b7 JM |
4516 | |
4517 | /* Forget saved values of SAVE_EXPRs. */ | |
0ee28590 JJ |
4518 | unsigned int i; |
4519 | tree save_expr; | |
4520 | FOR_EACH_VEC_ELT (save_exprs, i, save_expr) | |
8e007055 | 4521 | ctx->global->values.remove (save_expr); |
0ee28590 | 4522 | save_exprs.truncate (0); |
43574e4f | 4523 | |
5ec2cd9f JM |
4524 | if (++count >= constexpr_loop_limit) |
4525 | { | |
4526 | if (!ctx->quiet) | |
f9d0ca40 | 4527 | error_at (cp_expr_loc_or_input_loc (t), |
84fa214d | 4528 | "%<constexpr%> loop iteration count exceeds limit of %d " |
a3f9f006 | 4529 | "(use %<-fconstexpr-loop-limit=%> to increase the limit)", |
5ec2cd9f JM |
4530 | constexpr_loop_limit); |
4531 | *non_constant_p = true; | |
4532 | break; | |
4533 | } | |
56632b27 | 4534 | } |
4b390698 JJ |
4535 | while (!returns (jump_target) |
4536 | && !breaks (jump_target) | |
43574e4f JJ |
4537 | && !continues (jump_target) |
4538 | && (!switches (jump_target) || count == 0) | |
4b390698 | 4539 | && !*non_constant_p); |
d259b234 | 4540 | |
43574e4f | 4541 | /* Forget saved values of SAVE_EXPRs. */ |
0ee28590 JJ |
4542 | unsigned int i; |
4543 | tree save_expr; | |
4544 | FOR_EACH_VEC_ELT (save_exprs, i, save_expr) | |
8e007055 | 4545 | ctx->global->values.remove (save_expr); |
39dce2b7 | 4546 | |
56632b27 JM |
4547 | return NULL_TREE; |
4548 | } | |
4549 | ||
4550 | /* Evaluate a SWITCH_EXPR for side-effects. Handles switch and break jump | |
4551 | semantics. */ | |
4552 | ||
4553 | static tree | |
4554 | cxx_eval_switch_expr (const constexpr_ctx *ctx, tree t, | |
56632b27 JM |
4555 | bool *non_constant_p, bool *overflow_p, |
4556 | tree *jump_target) | |
4557 | { | |
43574e4f JJ |
4558 | tree cond |
4559 | = TREE_CODE (t) == SWITCH_STMT ? SWITCH_STMT_COND (t) : SWITCH_COND (t); | |
2b3ab879 | 4560 | cond = cxx_eval_constant_expression (ctx, cond, false, |
5a804683 | 4561 | non_constant_p, overflow_p); |
56632b27 JM |
4562 | VERIFY_CONSTANT (cond); |
4563 | *jump_target = cond; | |
4564 | ||
43574e4f JJ |
4565 | tree body |
4566 | = TREE_CODE (t) == SWITCH_STMT ? SWITCH_STMT_BODY (t) : SWITCH_BODY (t); | |
4b390698 JJ |
4567 | constexpr_ctx new_ctx = *ctx; |
4568 | constexpr_switch_state css = css_default_not_seen; | |
4569 | new_ctx.css_state = &css; | |
4570 | cxx_eval_constant_expression (&new_ctx, body, false, | |
4571 | non_constant_p, overflow_p, jump_target); | |
4572 | if (switches (jump_target) && css == css_default_seen) | |
4573 | { | |
4574 | /* If the SWITCH_EXPR body has default: label, process it once again, | |
4575 | this time instructing label_matches to return true for default: | |
4576 | label on switches (jump_target). */ | |
4577 | css = css_default_processing; | |
4578 | cxx_eval_constant_expression (&new_ctx, body, false, | |
4579 | non_constant_p, overflow_p, jump_target); | |
4580 | } | |
56632b27 JM |
4581 | if (breaks (jump_target) || switches (jump_target)) |
4582 | *jump_target = NULL_TREE; | |
4583 | return NULL_TREE; | |
4584 | } | |
4585 | ||
89262ec6 JM |
4586 | /* Find the object of TYPE under initialization in CTX. */ |
4587 | ||
4588 | static tree | |
4589 | lookup_placeholder (const constexpr_ctx *ctx, bool lval, tree type) | |
4590 | { | |
fbd603c4 | 4591 | if (!ctx) |
89262ec6 JM |
4592 | return NULL_TREE; |
4593 | ||
4594 | /* We could use ctx->object unconditionally, but using ctx->ctor when we | |
4595 | can is a minor optimization. */ | |
fbd603c4 | 4596 | if (!lval && ctx->ctor && same_type_p (TREE_TYPE (ctx->ctor), type)) |
89262ec6 JM |
4597 | return ctx->ctor; |
4598 | ||
fbd603c4 JM |
4599 | if (!ctx->object) |
4600 | return NULL_TREE; | |
4601 | ||
89262ec6 JM |
4602 | /* Since an object cannot have a field of its own type, we can search outward |
4603 | from ctx->object to find the unique containing object of TYPE. */ | |
4604 | tree ob = ctx->object; | |
4605 | while (ob) | |
4606 | { | |
4607 | if (same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (ob), type)) | |
4608 | break; | |
4609 | if (handled_component_p (ob)) | |
4610 | ob = TREE_OPERAND (ob, 0); | |
4611 | else | |
4612 | ob = NULL_TREE; | |
4613 | } | |
4614 | ||
4615 | return ob; | |
4616 | } | |
4617 | ||
7c814975 MP |
4618 | /* Complain about an attempt to evaluate inline assembly. */ |
4619 | ||
4620 | static void | |
4621 | inline_asm_in_constexpr_error (location_t loc) | |
4622 | { | |
4623 | auto_diagnostic_group d; | |
4624 | error_at (loc, "inline assembly is not a constant expression"); | |
4625 | inform (loc, "only unevaluated inline assembly is allowed in a " | |
4626 | "%<constexpr%> function in C++2a"); | |
4627 | } | |
4628 | ||
2d76680f PC |
4629 | /* Attempt to reduce the expression T to a constant value. |
4630 | On failure, issue diagnostic and return error_mark_node. */ | |
4631 | /* FIXME unify with c_fully_fold */ | |
60813a46 | 4632 | /* FIXME overflow_p is too global */ |
2d76680f PC |
4633 | |
4634 | static tree | |
3e605b20 | 4635 | cxx_eval_constant_expression (const constexpr_ctx *ctx, tree t, |
92a596e8 | 4636 | bool lval, |
56632b27 | 4637 | bool *non_constant_p, bool *overflow_p, |
3075affd | 4638 | tree *jump_target /* = NULL */) |
2d76680f | 4639 | { |
4b390698 JJ |
4640 | if (jump_target && *jump_target) |
4641 | { | |
4642 | /* If we are jumping, ignore all statements/expressions except those | |
4643 | that could have LABEL_EXPR or CASE_LABEL_EXPR in their bodies. */ | |
4644 | switch (TREE_CODE (t)) | |
4645 | { | |
4646 | case BIND_EXPR: | |
4647 | case STATEMENT_LIST: | |
4648 | case LOOP_EXPR: | |
4649 | case COND_EXPR: | |
43574e4f JJ |
4650 | case IF_STMT: |
4651 | case DO_STMT: | |
4652 | case WHILE_STMT: | |
4653 | case FOR_STMT: | |
4b390698 JJ |
4654 | break; |
4655 | case LABEL_EXPR: | |
4656 | case CASE_LABEL_EXPR: | |
4657 | if (label_matches (ctx, jump_target, t)) | |
4658 | /* Found it. */ | |
4659 | *jump_target = NULL_TREE; | |
4660 | return NULL_TREE; | |
4661 | default: | |
4662 | return NULL_TREE; | |
4663 | } | |
4664 | } | |
3075affd | 4665 | if (error_operand_p (t)) |
2d76680f PC |
4666 | { |
4667 | *non_constant_p = true; | |
4668 | return t; | |
4669 | } | |
7a649ef5 JM |
4670 | |
4671 | STRIP_ANY_LOCATION_WRAPPER (t); | |
4672 | ||
2d76680f PC |
4673 | if (CONSTANT_CLASS_P (t)) |
4674 | { | |
61637db3 JJ |
4675 | if (TREE_OVERFLOW (t)) |
4676 | { | |
4677 | if (!ctx->quiet) | |
4678 | permerror (input_location, "overflow in constant expression"); | |
4679 | if (!flag_permissive || ctx->quiet) | |
4680 | *overflow_p = true; | |
4681 | } | |
8bada5cd MS |
4682 | |
4683 | if (TREE_CODE (t) == INTEGER_CST | |
9f613f06 | 4684 | && TYPE_PTR_P (TREE_TYPE (t)) |
8bada5cd MS |
4685 | && !integer_zerop (t)) |
4686 | { | |
4687 | if (!ctx->quiet) | |
4688 | error ("value %qE of type %qT is not a constant expression", | |
4689 | t, TREE_TYPE (t)); | |
4690 | *non_constant_p = true; | |
4691 | } | |
4692 | ||
2d76680f PC |
4693 | return t; |
4694 | } | |
2d76680f | 4695 | |
a15ffa22 | 4696 | /* Avoid excessively long constexpr evaluations. */ |
8e007055 | 4697 | if (++ctx->global->constexpr_ops_count >= constexpr_ops_limit) |
a15ffa22 JJ |
4698 | { |
4699 | if (!ctx->quiet) | |
f9d0ca40 | 4700 | error_at (cp_expr_loc_or_input_loc (t), |
a15ffa22 | 4701 | "%<constexpr%> evaluation operation count exceeds limit of " |
a9c697b8 | 4702 | "%wd (use %<-fconstexpr-ops-limit=%> to increase the limit)", |
a15ffa22 | 4703 | constexpr_ops_limit); |
8e007055 | 4704 | ctx->global->constexpr_ops_count = INTTYPE_MINIMUM (HOST_WIDE_INT); |
a15ffa22 JJ |
4705 | *non_constant_p = true; |
4706 | return t; | |
4707 | } | |
4708 | ||
7a649ef5 JM |
4709 | constexpr_ctx new_ctx; |
4710 | tree r = t; | |
4711 | ||
8bada5cd MS |
4712 | tree_code tcode = TREE_CODE (t); |
4713 | switch (tcode) | |
2d76680f | 4714 | { |
60813a46 | 4715 | case RESULT_DECL: |
92a596e8 | 4716 | if (lval) |
60813a46 JM |
4717 | return t; |
4718 | /* We ask for an rvalue for the RESULT_DECL when indirecting | |
bf66b9b4 AH |
4719 | through an invisible reference, or in named return value |
4720 | optimization. */ | |
8e007055 | 4721 | if (tree *p = ctx->global->values.get (t)) |
1efb1dc2 MP |
4722 | return *p; |
4723 | else | |
4724 | { | |
4725 | if (!ctx->quiet) | |
4726 | error ("%qE is not a constant expression", t); | |
4727 | *non_constant_p = true; | |
4728 | } | |
4729 | break; | |
60813a46 | 4730 | |
2d76680f | 4731 | case VAR_DECL: |
70f40fea | 4732 | if (DECL_HAS_VALUE_EXPR_P (t)) |
c59fa7ea JM |
4733 | { |
4734 | if (is_normal_capture_proxy (t) | |
4735 | && current_function_decl == DECL_CONTEXT (t)) | |
4736 | { | |
4737 | /* Function parms aren't constexpr within the function | |
4738 | definition, so don't try to look at the closure. But if the | |
4739 | captured variable is constant, try to evaluate it directly. */ | |
4740 | r = DECL_CAPTURED_VARIABLE (t); | |
4741 | tree type = TREE_TYPE (t); | |
4742 | if (TYPE_REF_P (type) != TYPE_REF_P (TREE_TYPE (r))) | |
4743 | { | |
4744 | /* Adjust r to match the reference-ness of t. */ | |
4745 | if (TYPE_REF_P (type)) | |
4746 | r = build_address (r); | |
4747 | else | |
4748 | r = convert_from_reference (r); | |
4749 | } | |
4750 | } | |
4751 | else | |
4752 | r = DECL_VALUE_EXPR (t); | |
4753 | return cxx_eval_constant_expression (ctx, r, lval, non_constant_p, | |
4754 | overflow_p); | |
4755 | } | |
191816a3 | 4756 | /* fall through */ |
7c83622c JM |
4757 | case CONST_DECL: |
4758 | /* We used to not check lval for CONST_DECL, but darwin.c uses | |
4759 | CONST_DECL for aggregate constants. */ | |
92a596e8 | 4760 | if (lval) |
2d76680f | 4761 | return t; |
f4fce183 | 4762 | if (COMPLETE_TYPE_P (TREE_TYPE (t)) |
dbcd32f8 | 4763 | && is_really_empty_class (TREE_TYPE (t), /*ignore_vptr*/false)) |
7dc2b4a2 JM |
4764 | { |
4765 | /* If the class is empty, we aren't actually loading anything. */ | |
4766 | r = build_constructor (TREE_TYPE (t), NULL); | |
4767 | TREE_CONSTANT (r) = true; | |
4768 | } | |
4769 | else if (ctx->strict) | |
69eb4fde JM |
4770 | r = decl_really_constant_value (t); |
4771 | else | |
4772 | r = decl_constant_value (t); | |
2d76680f PC |
4773 | if (TREE_CODE (r) == TARGET_EXPR |
4774 | && TREE_CODE (TARGET_EXPR_INITIAL (r)) == CONSTRUCTOR) | |
4775 | r = TARGET_EXPR_INITIAL (r); | |
56a6f1d3 | 4776 | if (VAR_P (r)) |
8e007055 | 4777 | if (tree *p = ctx->global->values.get (r)) |
bd8f5bb2 MP |
4778 | if (*p != NULL_TREE) |
4779 | r = *p; | |
2d76680f PC |
4780 | if (DECL_P (r)) |
4781 | { | |
2b3ab879 | 4782 | if (!ctx->quiet) |
2d76680f PC |
4783 | non_const_var_error (r); |
4784 | *non_constant_p = true; | |
4785 | } | |
4786 | break; | |
4787 | ||
96a95ac1 AO |
4788 | case DEBUG_BEGIN_STMT: |
4789 | /* ??? It might be nice to retain this information somehow, so | |
4790 | as to be able to step into a constexpr function call. */ | |
4791 | /* Fall through. */ | |
4792 | ||
2d76680f PC |
4793 | case FUNCTION_DECL: |
4794 | case TEMPLATE_DECL: | |
4795 | case LABEL_DECL: | |
56632b27 JM |
4796 | case LABEL_EXPR: |
4797 | case CASE_LABEL_EXPR: | |
4b390698 | 4798 | case PREDICT_EXPR: |
2d76680f PC |
4799 | return t; |
4800 | ||
4801 | case PARM_DECL: | |
9f613f06 | 4802 | if (lval && !TYPE_REF_P (TREE_TYPE (t))) |
60813a46 | 4803 | /* glvalue use. */; |
8e007055 | 4804 | else if (tree *p = ctx->global->values.get (r)) |
60813a46 | 4805 | r = *p; |
92a596e8 | 4806 | else if (lval) |
2d76680f | 4807 | /* Defer in case this is only used for its type. */; |
9f613f06 | 4808 | else if (TYPE_REF_P (TREE_TYPE (t))) |
f2acb8ad | 4809 | /* Defer, there's no lvalue->rvalue conversion. */; |
1c2f613f | 4810 | else if (COMPLETE_TYPE_P (TREE_TYPE (t)) |
dbcd32f8 | 4811 | && is_really_empty_class (TREE_TYPE (t), /*ignore_vptr*/false)) |
052beba4 JM |
4812 | { |
4813 | /* If the class is empty, we aren't actually loading anything. */ | |
4814 | r = build_constructor (TREE_TYPE (t), NULL); | |
4815 | TREE_CONSTANT (r) = true; | |
4816 | } | |
2d76680f PC |
4817 | else |
4818 | { | |
2b3ab879 | 4819 | if (!ctx->quiet) |
2d76680f PC |
4820 | error ("%qE is not a constant expression", t); |
4821 | *non_constant_p = true; | |
4822 | } | |
4823 | break; | |
4824 | ||
4825 | case CALL_EXPR: | |
4826 | case AGGR_INIT_EXPR: | |
92a596e8 | 4827 | r = cxx_eval_call_expression (ctx, t, lval, |
2d76680f PC |
4828 | non_constant_p, overflow_p); |
4829 | break; | |
4830 | ||
60813a46 JM |
4831 | case DECL_EXPR: |
4832 | { | |
4833 | r = DECL_EXPR_DECL (t); | |
43574e4f JJ |
4834 | if (TREE_CODE (r) == USING_DECL) |
4835 | { | |
4836 | r = void_node; | |
4837 | break; | |
4838 | } | |
60813a46 JM |
4839 | if (AGGREGATE_TYPE_P (TREE_TYPE (r)) |
4840 | || VECTOR_TYPE_P (TREE_TYPE (r))) | |
4841 | { | |
4842 | new_ctx = *ctx; | |
4843 | new_ctx.object = r; | |
4844 | new_ctx.ctor = build_constructor (TREE_TYPE (r), NULL); | |
e8c48716 | 4845 | CONSTRUCTOR_NO_CLEARING (new_ctx.ctor) = true; |
8e007055 | 4846 | ctx->global->values.put (r, new_ctx.ctor); |
60813a46 JM |
4847 | ctx = &new_ctx; |
4848 | } | |
4849 | ||
4850 | if (tree init = DECL_INITIAL (r)) | |
4851 | { | |
4852 | init = cxx_eval_constant_expression (ctx, init, | |
2b3ab879 | 4853 | false, |
5a804683 | 4854 | non_constant_p, overflow_p); |
7f0e23e9 | 4855 | /* Don't share a CONSTRUCTOR that might be changed. */ |
0146e25f | 4856 | init = unshare_constructor (init); |
04e1749c MP |
4857 | /* Remember that a constant object's constructor has already |
4858 | run. */ | |
4859 | if (CLASS_TYPE_P (TREE_TYPE (r)) | |
4860 | && CP_TYPE_CONST_P (TREE_TYPE (r))) | |
4861 | TREE_READONLY (init) = true; | |
8e007055 | 4862 | ctx->global->values.put (r, init); |
60813a46 JM |
4863 | } |
4864 | else if (ctx == &new_ctx) | |
4865 | /* We gave it a CONSTRUCTOR above. */; | |
4866 | else | |
8e007055 | 4867 | ctx->global->values.put (r, NULL_TREE); |
60813a46 JM |
4868 | } |
4869 | break; | |
4870 | ||
2d76680f PC |
4871 | case TARGET_EXPR: |
4872 | if (!literal_type_p (TREE_TYPE (t))) | |
4873 | { | |
2b3ab879 | 4874 | if (!ctx->quiet) |
2d76680f | 4875 | { |
097f82ec | 4876 | auto_diagnostic_group d; |
2d76680f PC |
4877 | error ("temporary of non-literal type %qT in a " |
4878 | "constant expression", TREE_TYPE (t)); | |
4879 | explain_non_literal_class (TREE_TYPE (t)); | |
4880 | } | |
4881 | *non_constant_p = true; | |
4882 | break; | |
4883 | } | |
3e605b20 JM |
4884 | if ((AGGREGATE_TYPE_P (TREE_TYPE (t)) || VECTOR_TYPE_P (TREE_TYPE (t)))) |
4885 | { | |
4886 | /* We're being expanded without an explicit target, so start | |
4887 | initializing a new object; expansion with an explicit target | |
4888 | strips the TARGET_EXPR before we get here. */ | |
4889 | new_ctx = *ctx; | |
4890 | new_ctx.ctor = build_constructor (TREE_TYPE (t), NULL); | |
e8c48716 | 4891 | CONSTRUCTOR_NO_CLEARING (new_ctx.ctor) = true; |
3e605b20 | 4892 | new_ctx.object = TARGET_EXPR_SLOT (t); |
8e007055 | 4893 | ctx->global->values.put (new_ctx.object, new_ctx.ctor); |
3e605b20 JM |
4894 | ctx = &new_ctx; |
4895 | } | |
92a596e8 | 4896 | /* Pass false for 'lval' because this indicates |
2d76680f | 4897 | initialization of a temporary. */ |
3e605b20 | 4898 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), |
2b3ab879 | 4899 | false, |
5a804683 | 4900 | non_constant_p, overflow_p); |
2d76680f PC |
4901 | if (!*non_constant_p) |
4902 | /* Adjust the type of the result to the type of the temporary. */ | |
4903 | r = adjust_temp_type (TREE_TYPE (t), r); | |
92a596e8 | 4904 | if (lval) |
f2acb8ad JM |
4905 | { |
4906 | tree slot = TARGET_EXPR_SLOT (t); | |
0146e25f | 4907 | r = unshare_constructor (r); |
8e007055 | 4908 | ctx->global->values.put (slot, r); |
f2acb8ad JM |
4909 | return slot; |
4910 | } | |
2d76680f PC |
4911 | break; |
4912 | ||
60813a46 | 4913 | case INIT_EXPR: |
60813a46 | 4914 | case MODIFY_EXPR: |
4b390698 | 4915 | gcc_assert (jump_target == NULL || *jump_target == NULL_TREE); |
92a596e8 | 4916 | r = cxx_eval_store_expression (ctx, t, lval, |
60813a46 JM |
4917 | non_constant_p, overflow_p); |
4918 | break; | |
4919 | ||
2d76680f | 4920 | case SCOPE_REF: |
3e605b20 | 4921 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), |
92a596e8 | 4922 | lval, |
5a804683 | 4923 | non_constant_p, overflow_p); |
2d76680f PC |
4924 | break; |
4925 | ||
4926 | case RETURN_EXPR: | |
75e0295b MP |
4927 | if (TREE_OPERAND (t, 0) != NULL_TREE) |
4928 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), | |
4929 | lval, | |
4930 | non_constant_p, overflow_p); | |
43574e4f JJ |
4931 | /* FALLTHRU */ |
4932 | case BREAK_STMT: | |
4933 | case CONTINUE_STMT: | |
019e0ae8 MP |
4934 | if (jump_target) |
4935 | *jump_target = t; | |
4936 | else | |
4937 | { | |
4938 | /* Can happen with ({ return true; }) && false; passed to | |
4939 | maybe_constant_value. There is nothing to jump over in this | |
4940 | case, and the bug will be diagnosed later. */ | |
4941 | gcc_assert (ctx->quiet); | |
4942 | *non_constant_p = true; | |
4943 | } | |
56632b27 JM |
4944 | break; |
4945 | ||
cabaf50a JM |
4946 | case SAVE_EXPR: |
4947 | /* Avoid evaluating a SAVE_EXPR more than once. */ | |
8e007055 | 4948 | if (tree *p = ctx->global->values.get (t)) |
cabaf50a JM |
4949 | r = *p; |
4950 | else | |
4951 | { | |
12d9ce19 | 4952 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), false, |
cabaf50a | 4953 | non_constant_p, overflow_p); |
8e007055 | 4954 | ctx->global->values.put (t, r); |
39dce2b7 | 4955 | if (ctx->save_exprs) |
0ee28590 | 4956 | ctx->save_exprs->safe_push (t); |
cabaf50a JM |
4957 | } |
4958 | break; | |
4959 | ||
2d76680f PC |
4960 | case NON_LVALUE_EXPR: |
4961 | case TRY_CATCH_EXPR: | |
769430b2 | 4962 | case TRY_BLOCK: |
2d76680f PC |
4963 | case CLEANUP_POINT_EXPR: |
4964 | case MUST_NOT_THROW_EXPR: | |
60813a46 JM |
4965 | case EXPR_STMT: |
4966 | case EH_SPEC_BLOCK: | |
3e605b20 | 4967 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), |
92a596e8 | 4968 | lval, |
56632b27 JM |
4969 | non_constant_p, overflow_p, |
4970 | jump_target); | |
2d76680f PC |
4971 | break; |
4972 | ||
769430b2 JM |
4973 | case TRY_FINALLY_EXPR: |
4974 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval, | |
4975 | non_constant_p, overflow_p, | |
4976 | jump_target); | |
4977 | if (!*non_constant_p) | |
4978 | /* Also evaluate the cleanup. */ | |
4979 | cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), true, | |
4980 | non_constant_p, overflow_p, | |
4981 | jump_target); | |
4982 | break; | |
4983 | ||
43574e4f | 4984 | case CLEANUP_STMT: |
1006c9d4 JJ |
4985 | { |
4986 | tree initial_jump_target = jump_target ? *jump_target : NULL_TREE; | |
4987 | r = cxx_eval_constant_expression (ctx, CLEANUP_BODY (t), lval, | |
4988 | non_constant_p, overflow_p, | |
4989 | jump_target); | |
4990 | if (!CLEANUP_EH_ONLY (t) && !*non_constant_p) | |
acfdb960 JJ |
4991 | { |
4992 | location_t loc = input_location; | |
4993 | if (EXPR_HAS_LOCATION (t)) | |
4994 | input_location = EXPR_LOCATION (t); | |
4995 | /* Also evaluate the cleanup. If we weren't skipping at the | |
4996 | start of the CLEANUP_BODY, change jump_target temporarily | |
4997 | to &initial_jump_target, so that even a return or break or | |
4998 | continue in the body doesn't skip the cleanup. */ | |
4999 | cxx_eval_constant_expression (ctx, CLEANUP_EXPR (t), true, | |
5000 | non_constant_p, overflow_p, | |
5001 | jump_target ? &initial_jump_target | |
5002 | : NULL); | |
5003 | input_location = loc; | |
5004 | } | |
1006c9d4 | 5005 | } |
43574e4f JJ |
5006 | break; |
5007 | ||
2d76680f PC |
5008 | /* These differ from cxx_eval_unary_expression in that this doesn't |
5009 | check for a constant operand or result; an address can be | |
5010 | constant without its operand being, and vice versa. */ | |
cda0a029 | 5011 | case MEM_REF: |
2d76680f | 5012 | case INDIRECT_REF: |
92a596e8 | 5013 | r = cxx_eval_indirect_ref (ctx, t, lval, |
2d76680f PC |
5014 | non_constant_p, overflow_p); |
5015 | break; | |
5016 | ||
5017 | case ADDR_EXPR: | |
5018 | { | |
5019 | tree oldop = TREE_OPERAND (t, 0); | |
3e605b20 | 5020 | tree op = cxx_eval_constant_expression (ctx, oldop, |
92a596e8 | 5021 | /*lval*/true, |
5a804683 | 5022 | non_constant_p, overflow_p); |
2d76680f PC |
5023 | /* Don't VERIFY_CONSTANT here. */ |
5024 | if (*non_constant_p) | |
5025 | return t; | |
f2acb8ad | 5026 | gcc_checking_assert (TREE_CODE (op) != CONSTRUCTOR); |
2d76680f PC |
5027 | /* This function does more aggressive folding than fold itself. */ |
5028 | r = build_fold_addr_expr_with_type (op, TREE_TYPE (t)); | |
5029 | if (TREE_CODE (r) == ADDR_EXPR && TREE_OPERAND (r, 0) == oldop) | |
7a649ef5 JM |
5030 | { |
5031 | ggc_free (r); | |
5032 | return t; | |
5033 | } | |
2d76680f PC |
5034 | break; |
5035 | } | |
5036 | ||
5037 | case REALPART_EXPR: | |
5038 | case IMAGPART_EXPR: | |
87713c6a JJ |
5039 | if (lval) |
5040 | { | |
5041 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval, | |
5042 | non_constant_p, overflow_p); | |
5043 | if (r == error_mark_node) | |
5044 | ; | |
5045 | else if (r == TREE_OPERAND (t, 0)) | |
5046 | r = t; | |
5047 | else | |
5048 | r = fold_build1 (TREE_CODE (t), TREE_TYPE (t), r); | |
5049 | break; | |
5050 | } | |
5051 | /* FALLTHRU */ | |
2d76680f PC |
5052 | case CONJ_EXPR: |
5053 | case FIX_TRUNC_EXPR: | |
5054 | case FLOAT_EXPR: | |
5055 | case NEGATE_EXPR: | |
5056 | case ABS_EXPR: | |
e28fadbc | 5057 | case ABSU_EXPR: |
2d76680f PC |
5058 | case BIT_NOT_EXPR: |
5059 | case TRUTH_NOT_EXPR: | |
5060 | case FIXED_CONVERT_EXPR: | |
92a596e8 | 5061 | r = cxx_eval_unary_expression (ctx, t, lval, |
2d76680f PC |
5062 | non_constant_p, overflow_p); |
5063 | break; | |
5064 | ||
5065 | case SIZEOF_EXPR: | |
99e764a2 MP |
5066 | r = fold_sizeof_expr (t); |
5067 | /* In a template, fold_sizeof_expr may merely create a new SIZEOF_EXPR, | |
5068 | which could lead to an infinite recursion. */ | |
5069 | if (TREE_CODE (r) != SIZEOF_EXPR) | |
5070 | r = cxx_eval_constant_expression (ctx, r, lval, | |
5071 | non_constant_p, overflow_p, | |
5072 | jump_target); | |
5073 | else | |
5074 | { | |
5075 | *non_constant_p = true; | |
5076 | gcc_assert (ctx->quiet); | |
5077 | } | |
5078 | ||
2d76680f PC |
5079 | break; |
5080 | ||
5081 | case COMPOUND_EXPR: | |
5082 | { | |
5083 | /* check_return_expr sometimes wraps a TARGET_EXPR in a | |
5084 | COMPOUND_EXPR; don't get confused. Also handle EMPTY_CLASS_EXPR | |
5085 | introduced by build_call_a. */ | |
5086 | tree op0 = TREE_OPERAND (t, 0); | |
5087 | tree op1 = TREE_OPERAND (t, 1); | |
5088 | STRIP_NOPS (op1); | |
5089 | if ((TREE_CODE (op0) == TARGET_EXPR && op1 == TARGET_EXPR_SLOT (op0)) | |
5090 | || TREE_CODE (op1) == EMPTY_CLASS_EXPR) | |
2b3ab879 | 5091 | r = cxx_eval_constant_expression (ctx, op0, |
92a596e8 | 5092 | lval, non_constant_p, overflow_p, |
56632b27 | 5093 | jump_target); |
2d76680f PC |
5094 | else |
5095 | { | |
5096 | /* Check that the LHS is constant and then discard it. */ | |
2b3ab879 | 5097 | cxx_eval_constant_expression (ctx, op0, |
12d9ce19 | 5098 | true, non_constant_p, overflow_p, |
56632b27 | 5099 | jump_target); |
06ec22b7 JM |
5100 | if (*non_constant_p) |
5101 | return t; | |
2d76680f | 5102 | op1 = TREE_OPERAND (t, 1); |
2b3ab879 | 5103 | r = cxx_eval_constant_expression (ctx, op1, |
92a596e8 | 5104 | lval, non_constant_p, overflow_p, |
56632b27 | 5105 | jump_target); |
2d76680f PC |
5106 | } |
5107 | } | |
5108 | break; | |
5109 | ||
5110 | case POINTER_PLUS_EXPR: | |
1af4ebf5 | 5111 | case POINTER_DIFF_EXPR: |
2d76680f PC |
5112 | case PLUS_EXPR: |
5113 | case MINUS_EXPR: | |
5114 | case MULT_EXPR: | |
5115 | case TRUNC_DIV_EXPR: | |
5116 | case CEIL_DIV_EXPR: | |
5117 | case FLOOR_DIV_EXPR: | |
5118 | case ROUND_DIV_EXPR: | |
5119 | case TRUNC_MOD_EXPR: | |
5120 | case CEIL_MOD_EXPR: | |
5121 | case ROUND_MOD_EXPR: | |
5122 | case RDIV_EXPR: | |
5123 | case EXACT_DIV_EXPR: | |
5124 | case MIN_EXPR: | |
5125 | case MAX_EXPR: | |
5126 | case LSHIFT_EXPR: | |
5127 | case RSHIFT_EXPR: | |
2d76680f PC |
5128 | case BIT_IOR_EXPR: |
5129 | case BIT_XOR_EXPR: | |
5130 | case BIT_AND_EXPR: | |
5131 | case TRUTH_XOR_EXPR: | |
5132 | case LT_EXPR: | |
5133 | case LE_EXPR: | |
5134 | case GT_EXPR: | |
5135 | case GE_EXPR: | |
5136 | case EQ_EXPR: | |
5137 | case NE_EXPR: | |
5138 | case UNORDERED_EXPR: | |
5139 | case ORDERED_EXPR: | |
5140 | case UNLT_EXPR: | |
5141 | case UNLE_EXPR: | |
5142 | case UNGT_EXPR: | |
5143 | case UNGE_EXPR: | |
5144 | case UNEQ_EXPR: | |
5145 | case LTGT_EXPR: | |
5146 | case RANGE_EXPR: | |
5147 | case COMPLEX_EXPR: | |
92a596e8 | 5148 | r = cxx_eval_binary_expression (ctx, t, lval, |
2d76680f PC |
5149 | non_constant_p, overflow_p); |
5150 | break; | |
5151 | ||
5152 | /* fold can introduce non-IF versions of these; still treat them as | |
5153 | short-circuiting. */ | |
5154 | case TRUTH_AND_EXPR: | |
5155 | case TRUTH_ANDIF_EXPR: | |
3e605b20 | 5156 | r = cxx_eval_logical_expression (ctx, t, boolean_false_node, |
2d76680f | 5157 | boolean_true_node, |
92a596e8 | 5158 | lval, |
2d76680f PC |
5159 | non_constant_p, overflow_p); |
5160 | break; | |
5161 | ||
5162 | case TRUTH_OR_EXPR: | |
5163 | case TRUTH_ORIF_EXPR: | |
3e605b20 | 5164 | r = cxx_eval_logical_expression (ctx, t, boolean_true_node, |
2d76680f | 5165 | boolean_false_node, |
92a596e8 | 5166 | lval, |
2d76680f PC |
5167 | non_constant_p, overflow_p); |
5168 | break; | |
5169 | ||
5170 | case ARRAY_REF: | |
92a596e8 | 5171 | r = cxx_eval_array_reference (ctx, t, lval, |
2d76680f PC |
5172 | non_constant_p, overflow_p); |
5173 | break; | |
5174 | ||
5175 | case COMPONENT_REF: | |
5176 | if (is_overloaded_fn (t)) | |
5177 | { | |
5178 | /* We can only get here in checking mode via | |
5179 | build_non_dependent_expr, because any expression that | |
5180 | calls or takes the address of the function will have | |
5181 | pulled a FUNCTION_DECL out of the COMPONENT_REF. */ | |
2b3ab879 | 5182 | gcc_checking_assert (ctx->quiet || errorcount); |
2d76680f PC |
5183 | *non_constant_p = true; |
5184 | return t; | |
5185 | } | |
92a596e8 | 5186 | r = cxx_eval_component_reference (ctx, t, lval, |
2d76680f PC |
5187 | non_constant_p, overflow_p); |
5188 | break; | |
5189 | ||
5190 | case BIT_FIELD_REF: | |
92a596e8 | 5191 | r = cxx_eval_bit_field_ref (ctx, t, lval, |
2d76680f PC |
5192 | non_constant_p, overflow_p); |
5193 | break; | |
5194 | ||
5195 | case COND_EXPR: | |
43574e4f | 5196 | case IF_STMT: |
4b390698 JJ |
5197 | if (jump_target && *jump_target) |
5198 | { | |
e9fa2f6d | 5199 | tree orig_jump = *jump_target; |
43574e4f JJ |
5200 | tree arg = ((TREE_CODE (t) != IF_STMT || TREE_OPERAND (t, 1)) |
5201 | ? TREE_OPERAND (t, 1) : void_node); | |
4b390698 JJ |
5202 | /* When jumping to a label, the label might be either in the |
5203 | then or else blocks, so process then block first in skipping | |
5204 | mode first, and if we are still in the skipping mode at its end, | |
5205 | process the else block too. */ | |
43574e4f JJ |
5206 | r = cxx_eval_constant_expression (ctx, arg, lval, non_constant_p, |
5207 | overflow_p, jump_target); | |
e9fa2f6d MP |
5208 | /* It's possible that we found the label in the then block. But |
5209 | it could have been followed by another jumping statement, e.g. | |
5210 | say we're looking for case 1: | |
5211 | if (cond) | |
5212 | { | |
5213 | // skipped statements | |
5214 | case 1:; // clears up *jump_target | |
5215 | return 1; // and sets it to a RETURN_EXPR | |
5216 | } | |
5217 | else { ... } | |
5218 | in which case we need not go looking to the else block. | |
5219 | (goto is not allowed in a constexpr function.) */ | |
5220 | if (*jump_target == orig_jump) | |
43574e4f JJ |
5221 | { |
5222 | arg = ((TREE_CODE (t) != IF_STMT || TREE_OPERAND (t, 2)) | |
5223 | ? TREE_OPERAND (t, 2) : void_node); | |
5224 | r = cxx_eval_constant_expression (ctx, arg, lval, non_constant_p, | |
5225 | overflow_p, jump_target); | |
5226 | } | |
4b390698 JJ |
5227 | break; |
5228 | } | |
92a596e8 | 5229 | r = cxx_eval_conditional_expression (ctx, t, lval, |
56632b27 JM |
5230 | non_constant_p, overflow_p, |
5231 | jump_target); | |
2d76680f | 5232 | break; |
f370e36d JJ |
5233 | case VEC_COND_EXPR: |
5234 | r = cxx_eval_vector_conditional_expression (ctx, t, non_constant_p, | |
5235 | overflow_p); | |
5236 | break; | |
2d76680f PC |
5237 | |
5238 | case CONSTRUCTOR: | |
35d87f01 | 5239 | if (TREE_CONSTANT (t) && reduced_constant_expression_p (t)) |
2d63bc39 JM |
5240 | { |
5241 | /* Don't re-process a constant CONSTRUCTOR, but do fold it to | |
5242 | VECTOR_CST if applicable. */ | |
ac9ec198 | 5243 | verify_constructor_flags (t); |
2d63bc39 JM |
5244 | if (TREE_CONSTANT (t)) |
5245 | return fold (t); | |
5246 | } | |
92a596e8 | 5247 | r = cxx_eval_bare_aggregate (ctx, t, lval, |
2d76680f PC |
5248 | non_constant_p, overflow_p); |
5249 | break; | |
5250 | ||
5251 | case VEC_INIT_EXPR: | |
5252 | /* We can get this in a defaulted constructor for a class with a | |
5253 | non-static data member of array type. Either the initializer will | |
5254 | be NULL, meaning default-initialization, or it will be an lvalue | |
5255 | or xvalue of the same type, meaning direct-initialization from the | |
5256 | corresponding member. */ | |
92a596e8 | 5257 | r = cxx_eval_vec_init (ctx, t, lval, |
2d76680f PC |
5258 | non_constant_p, overflow_p); |
5259 | break; | |
5260 | ||
2d76680f | 5261 | case VEC_PERM_EXPR: |
92a596e8 | 5262 | r = cxx_eval_trinary_expression (ctx, t, lval, |
2d76680f PC |
5263 | non_constant_p, overflow_p); |
5264 | break; | |
5265 | ||
7d75ea04 JJ |
5266 | case NOP_EXPR: |
5267 | if (REINTERPRET_CAST_P (t)) | |
5268 | { | |
5269 | if (!ctx->quiet) | |
f9d0ca40 | 5270 | error_at (cp_expr_loc_or_input_loc (t), |
a9c697b8 | 5271 | "%<reinterpret_cast%> is not a constant expression"); |
7d75ea04 JJ |
5272 | *non_constant_p = true; |
5273 | return t; | |
5274 | } | |
5275 | /* FALLTHROUGH. */ | |
2d76680f PC |
5276 | case CONVERT_EXPR: |
5277 | case VIEW_CONVERT_EXPR: | |
cda0a029 | 5278 | case UNARY_PLUS_EXPR: |
2d76680f PC |
5279 | { |
5280 | tree oldop = TREE_OPERAND (t, 0); | |
cda0a029 | 5281 | |
3e605b20 | 5282 | tree op = cxx_eval_constant_expression (ctx, oldop, |
92a596e8 | 5283 | lval, |
5a804683 | 5284 | non_constant_p, overflow_p); |
2d76680f PC |
5285 | if (*non_constant_p) |
5286 | return t; | |
dcdbc004 | 5287 | tree type = TREE_TYPE (t); |
02a8575c JM |
5288 | |
5289 | if (VOID_TYPE_P (type)) | |
5290 | return void_node; | |
5291 | ||
8e007055 | 5292 | if (TREE_CODE (op) == PTRMEM_CST && !TYPE_PTRMEM_P (type)) |
dcdbc004 | 5293 | op = cplus_expand_constant (op); |
7d75ea04 | 5294 | |
05bf54c3 MP |
5295 | if (TREE_CODE (op) == PTRMEM_CST && tcode == NOP_EXPR) |
5296 | { | |
7d75ea04 JJ |
5297 | if (!same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (op)) |
5298 | && !can_convert_qual (type, op)) | |
5299 | op = cplus_expand_constant (op); | |
5300 | return cp_fold_convert (type, op); | |
05bf54c3 | 5301 | } |
8bada5cd | 5302 | |
71a93b08 | 5303 | if (INDIRECT_TYPE_P (type) && TREE_CODE (op) == INTEGER_CST) |
2d76680f | 5304 | { |
8bada5cd MS |
5305 | if (integer_zerop (op)) |
5306 | { | |
9f613f06 | 5307 | if (TYPE_REF_P (type)) |
8bada5cd MS |
5308 | { |
5309 | if (!ctx->quiet) | |
f9d0ca40 | 5310 | error_at (cp_expr_loc_or_input_loc (t), |
8bada5cd MS |
5311 | "dereferencing a null pointer"); |
5312 | *non_constant_p = true; | |
5313 | return t; | |
5314 | } | |
9f613f06 | 5315 | else if (TYPE_PTR_P (TREE_TYPE (op))) |
8bada5cd MS |
5316 | { |
5317 | tree from = TREE_TYPE (op); | |
5318 | ||
5319 | if (!can_convert (type, from, tf_none)) | |
5320 | { | |
5321 | if (!ctx->quiet) | |
f9d0ca40 | 5322 | error_at (cp_expr_loc_or_input_loc (t), |
8bada5cd MS |
5323 | "conversion of %qT null pointer to %qT " |
5324 | "is not a constant expression", | |
5325 | from, type); | |
5326 | *non_constant_p = true; | |
5327 | return t; | |
5328 | } | |
5329 | } | |
5330 | } | |
5331 | else | |
5332 | { | |
5333 | /* This detects for example: | |
5334 | reinterpret_cast<void*>(sizeof 0) | |
5335 | */ | |
5336 | if (!ctx->quiet) | |
f9d0ca40 | 5337 | error_at (cp_expr_loc_or_input_loc (t), |
8bada5cd | 5338 | "%<reinterpret_cast<%T>(%E)%> is not " |
64d6d399 | 5339 | "a constant expression", |
8bada5cd MS |
5340 | type, op); |
5341 | *non_constant_p = true; | |
5342 | return t; | |
5343 | } | |
2d76680f | 5344 | } |
7d75ea04 | 5345 | |
8e007055 JJ |
5346 | if (INDIRECT_TYPE_P (type) |
5347 | && TREE_CODE (op) == NOP_EXPR | |
5348 | && TREE_TYPE (op) == ptr_type_node | |
5349 | && TREE_CODE (TREE_OPERAND (op, 0)) == ADDR_EXPR | |
5350 | && VAR_P (TREE_OPERAND (TREE_OPERAND (op, 0), 0)) | |
5351 | && DECL_NAME (TREE_OPERAND (TREE_OPERAND (op, 0), | |
5352 | 0)) == heap_uninit_identifier) | |
5353 | { | |
5354 | tree var = TREE_OPERAND (TREE_OPERAND (op, 0), 0); | |
5355 | tree var_size = TYPE_SIZE_UNIT (TREE_TYPE (var)); | |
5356 | tree elt_type = TREE_TYPE (type); | |
5357 | tree cookie_size = NULL_TREE; | |
5358 | if (TREE_CODE (elt_type) == RECORD_TYPE | |
5359 | && TYPE_NAME (elt_type) == heap_identifier) | |
5360 | { | |
5361 | tree fld1 = TYPE_FIELDS (elt_type); | |
5362 | tree fld2 = DECL_CHAIN (fld1); | |
5363 | elt_type = TREE_TYPE (TREE_TYPE (fld2)); | |
5364 | cookie_size = TYPE_SIZE_UNIT (TREE_TYPE (fld1)); | |
5365 | } | |
5366 | DECL_NAME (var) = heap_identifier; | |
5367 | TREE_TYPE (var) | |
5368 | = build_new_constexpr_heap_type (elt_type, cookie_size, | |
5369 | var_size); | |
5370 | TREE_TYPE (TREE_OPERAND (op, 0)) | |
5371 | = build_pointer_type (TREE_TYPE (var)); | |
5372 | } | |
5373 | ||
cda0a029 | 5374 | if (op == oldop && tcode != UNARY_PLUS_EXPR) |
2d76680f PC |
5375 | /* We didn't fold at the top so we could check for ptr-int |
5376 | conversion. */ | |
5377 | return fold (t); | |
7d75ea04 | 5378 | |
02a8575c JM |
5379 | tree sop; |
5380 | ||
e4511ca2 JM |
5381 | /* Handle an array's bounds having been deduced after we built |
5382 | the wrapping expression. */ | |
5383 | if (same_type_ignoring_tlq_and_bounds_p (type, TREE_TYPE (op))) | |
5384 | r = op; | |
02a8575c JM |
5385 | else if (sop = tree_strip_nop_conversions (op), |
5386 | sop != op && (same_type_ignoring_tlq_and_bounds_p | |
5387 | (type, TREE_TYPE (sop)))) | |
5388 | r = sop; | |
e4511ca2 | 5389 | else if (tcode == UNARY_PLUS_EXPR) |
cda0a029 JM |
5390 | r = fold_convert (TREE_TYPE (t), op); |
5391 | else | |
5392 | r = fold_build1 (tcode, type, op); | |
7d75ea04 | 5393 | |
2d76680f PC |
5394 | /* Conversion of an out-of-range value has implementation-defined |
5395 | behavior; the language considers it different from arithmetic | |
5396 | overflow, which is undefined. */ | |
5397 | if (TREE_OVERFLOW_P (r) && !TREE_OVERFLOW_P (op)) | |
5398 | TREE_OVERFLOW (r) = false; | |
5399 | } | |
5400 | break; | |
5401 | ||
5402 | case EMPTY_CLASS_EXPR: | |
5403 | /* This is good enough for a function argument that might not get | |
5404 | used, and they can't do anything with it, so just return it. */ | |
5405 | return t; | |
5406 | ||
60813a46 | 5407 | case STATEMENT_LIST: |
56632b27 JM |
5408 | new_ctx = *ctx; |
5409 | new_ctx.ctor = new_ctx.object = NULL_TREE; | |
2b3ab879 | 5410 | return cxx_eval_statement_list (&new_ctx, t, |
56632b27 | 5411 | non_constant_p, overflow_p, jump_target); |
60813a46 JM |
5412 | |
5413 | case BIND_EXPR: | |
5414 | return cxx_eval_constant_expression (ctx, BIND_EXPR_BODY (t), | |
92a596e8 | 5415 | lval, |
56632b27 JM |
5416 | non_constant_p, overflow_p, |
5417 | jump_target); | |
60813a46 | 5418 | |
2d76680f PC |
5419 | case PREINCREMENT_EXPR: |
5420 | case POSTINCREMENT_EXPR: | |
5421 | case PREDECREMENT_EXPR: | |
5422 | case POSTDECREMENT_EXPR: | |
2b3ab879 | 5423 | return cxx_eval_increment_expression (ctx, t, |
92a596e8 | 5424 | lval, non_constant_p, overflow_p); |
60813a46 JM |
5425 | |
5426 | case LAMBDA_EXPR: | |
2d76680f PC |
5427 | case NEW_EXPR: |
5428 | case VEC_NEW_EXPR: | |
5429 | case DELETE_EXPR: | |
5430 | case VEC_DELETE_EXPR: | |
5431 | case THROW_EXPR: | |
2d76680f PC |
5432 | case MODOP_EXPR: |
5433 | /* GCC internal stuff. */ | |
5434 | case VA_ARG_EXPR: | |
2d76680f PC |
5435 | case NON_DEPENDENT_EXPR: |
5436 | case BASELINK: | |
2d76680f | 5437 | case OFFSET_REF: |
2b3ab879 | 5438 | if (!ctx->quiet) |
f9d0ca40 | 5439 | error_at (cp_expr_loc_or_input_loc (t), |
64d6d399 | 5440 | "expression %qE is not a constant expression", t); |
2d76680f PC |
5441 | *non_constant_p = true; |
5442 | break; | |
5443 | ||
bf8d8309 MP |
5444 | case OBJ_TYPE_REF: |
5445 | { | |
5446 | /* Virtual function call. Let the constexpr machinery figure out | |
5447 | the dynamic type. */ | |
5448 | int token = tree_to_shwi (OBJ_TYPE_REF_TOKEN (t)); | |
5449 | tree obj = OBJ_TYPE_REF_OBJECT (t); | |
5450 | obj = cxx_eval_constant_expression (ctx, obj, lval, non_constant_p, | |
5451 | overflow_p); | |
5452 | /* We expect something in the form of &x.D.2103.D.2094; get x. */ | |
6a3ebcc6 JJ |
5453 | if (TREE_CODE (obj) != ADDR_EXPR |
5454 | || !DECL_P (get_base_address (TREE_OPERAND (obj, 0)))) | |
bf8d8309 MP |
5455 | { |
5456 | if (!ctx->quiet) | |
f9d0ca40 | 5457 | error_at (cp_expr_loc_or_input_loc (t), |
bf8d8309 MP |
5458 | "expression %qE is not a constant expression", t); |
5459 | *non_constant_p = true; | |
5460 | return t; | |
5461 | } | |
5462 | obj = TREE_OPERAND (obj, 0); | |
69deaf14 JJ |
5463 | while (TREE_CODE (obj) == COMPONENT_REF |
5464 | && DECL_FIELD_IS_BASE (TREE_OPERAND (obj, 1))) | |
bf8d8309 MP |
5465 | obj = TREE_OPERAND (obj, 0); |
5466 | tree objtype = TREE_TYPE (obj); | |
5467 | /* Find the function decl in the virtual functions list. TOKEN is | |
5468 | the DECL_VINDEX that says which function we're looking for. */ | |
5469 | tree virtuals = BINFO_VIRTUALS (TYPE_BINFO (objtype)); | |
582d2481 JJ |
5470 | if (TARGET_VTABLE_USES_DESCRIPTORS) |
5471 | token /= MAX (TARGET_VTABLE_USES_DESCRIPTORS, 1); | |
bf8d8309 MP |
5472 | r = TREE_VALUE (chain_index (token, virtuals)); |
5473 | break; | |
5474 | } | |
5475 | ||
3e605b20 | 5476 | case PLACEHOLDER_EXPR: |
89262ec6 JM |
5477 | /* Use of the value or address of the current object. */ |
5478 | if (tree ctor = lookup_placeholder (ctx, lval, TREE_TYPE (t))) | |
5479 | return cxx_eval_constant_expression (ctx, ctor, lval, | |
5480 | non_constant_p, overflow_p); | |
5481 | /* A placeholder without a referent. We can get here when | |
5482 | checking whether NSDMIs are noexcept, or in massage_init_elt; | |
5483 | just say it's non-constant for now. */ | |
5484 | gcc_assert (ctx->quiet); | |
5485 | *non_constant_p = true; | |
3e605b20 JM |
5486 | break; |
5487 | ||
06ec22b7 JM |
5488 | case EXIT_EXPR: |
5489 | { | |
5490 | tree cond = TREE_OPERAND (t, 0); | |
5491 | cond = cxx_eval_constant_expression (ctx, cond, /*lval*/false, | |
5492 | non_constant_p, overflow_p); | |
5493 | VERIFY_CONSTANT (cond); | |
5494 | if (integer_nonzerop (cond)) | |
5495 | *jump_target = t; | |
5496 | } | |
5497 | break; | |
5498 | ||
60813a46 | 5499 | case GOTO_EXPR: |
56632b27 | 5500 | *jump_target = TREE_OPERAND (t, 0); |
d49318d9 PC |
5501 | gcc_assert (breaks (jump_target) || continues (jump_target) |
5502 | /* Allow for jumping to a cdtor_label. */ | |
5503 | || returns (jump_target)); | |
56632b27 JM |
5504 | break; |
5505 | ||
60813a46 | 5506 | case LOOP_EXPR: |
43574e4f JJ |
5507 | case DO_STMT: |
5508 | case WHILE_STMT: | |
5509 | case FOR_STMT: | |
2b3ab879 | 5510 | cxx_eval_loop_expr (ctx, t, |
56632b27 JM |
5511 | non_constant_p, overflow_p, jump_target); |
5512 | break; | |
5513 | ||
60813a46 | 5514 | case SWITCH_EXPR: |
43574e4f | 5515 | case SWITCH_STMT: |
2b3ab879 | 5516 | cxx_eval_switch_expr (ctx, t, |
56632b27 | 5517 | non_constant_p, overflow_p, jump_target); |
60813a46 JM |
5518 | break; |
5519 | ||
971e17ff AS |
5520 | case REQUIRES_EXPR: |
5521 | /* It's possible to get a requires-expression in a constant | |
5522 | expression. For example: | |
5523 | ||
5524 | template<typename T> concept bool C() { | |
5525 | return requires (T t) { t; }; | |
5526 | } | |
5527 | ||
5528 | template<typename T> requires !C<T>() void f(T); | |
5529 | ||
5530 | Normalization leaves f with the associated constraint | |
5531 | '!requires (T t) { ... }' which is not transformed into | |
5532 | a constraint. */ | |
5533 | if (!processing_template_decl) | |
cb57504a | 5534 | return satisfy_constraint_expression (t); |
971e17ff AS |
5535 | else |
5536 | *non_constant_p = true; | |
5537 | return t; | |
5538 | ||
98e09245 | 5539 | case ANNOTATE_EXPR: |
98e09245 JJ |
5540 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), |
5541 | lval, | |
5542 | non_constant_p, overflow_p, | |
5543 | jump_target); | |
5544 | break; | |
5545 | ||
3664e317 JM |
5546 | case USING_STMT: |
5547 | r = void_node; | |
5548 | break; | |
5549 | ||
cb57504a JM |
5550 | case TEMPLATE_ID_EXPR: |
5551 | { | |
5552 | /* We can evaluate template-id that refers to a concept only if | |
5553 | the template arguments are non-dependent. */ | |
5554 | if (!concept_definition_p (TREE_OPERAND (t, 0))) | |
5555 | internal_error ("unexpected template-id %qE", t); | |
5556 | ||
5557 | if (!processing_template_decl) | |
5558 | return satisfy_constraint_expression (t); | |
5559 | else | |
5560 | *non_constant_p = true; | |
5561 | return t; | |
5562 | } | |
5563 | ||
529bc410 MP |
5564 | case ASM_EXPR: |
5565 | if (!ctx->quiet) | |
7c814975 | 5566 | inline_asm_in_constexpr_error (cp_expr_loc_or_input_loc (t)); |
529bc410 MP |
5567 | *non_constant_p = true; |
5568 | return t; | |
5569 | ||
2d76680f | 5570 | default: |
c6e7c499 JM |
5571 | if (STATEMENT_CODE_P (TREE_CODE (t))) |
5572 | { | |
5573 | /* This function doesn't know how to deal with pre-genericize | |
5574 | statements; this can only happen with statement-expressions, | |
5575 | so for now just fail. */ | |
5576 | if (!ctx->quiet) | |
5577 | error_at (EXPR_LOCATION (t), | |
64d6d399 | 5578 | "statement is not a constant expression"); |
c6e7c499 JM |
5579 | } |
5580 | else | |
5581 | internal_error ("unexpected expression %qE of kind %s", t, | |
5582 | get_tree_code_name (TREE_CODE (t))); | |
2d76680f PC |
5583 | *non_constant_p = true; |
5584 | break; | |
5585 | } | |
5586 | ||
5587 | if (r == error_mark_node) | |
5588 | *non_constant_p = true; | |
5589 | ||
5590 | if (*non_constant_p) | |
5591 | return t; | |
5592 | else | |
5593 | return r; | |
5594 | } | |
5595 | ||
e079dced JM |
5596 | /* P0859: A function is needed for constant evaluation if it is a constexpr |
5597 | function that is named by an expression ([basic.def.odr]) that is | |
5598 | potentially constant evaluated. | |
5599 | ||
5600 | So we need to instantiate any constexpr functions mentioned by the | |
5601 | expression even if the definition isn't needed for evaluating the | |
5602 | expression. */ | |
5603 | ||
5604 | static tree | |
5605 | instantiate_cx_fn_r (tree *tp, int *walk_subtrees, void */*data*/) | |
5606 | { | |
5607 | if (TREE_CODE (*tp) == FUNCTION_DECL | |
5608 | && DECL_DECLARED_CONSTEXPR_P (*tp) | |
5609 | && !DECL_INITIAL (*tp) | |
4fdda3ce | 5610 | && !trivial_fn_p (*tp) |
e079dced JM |
5611 | && DECL_TEMPLOID_INSTANTIATION (*tp)) |
5612 | { | |
5613 | ++function_depth; | |
5614 | instantiate_decl (*tp, /*defer_ok*/false, /*expl_inst*/false); | |
5615 | --function_depth; | |
5616 | } | |
5617 | else if (TREE_CODE (*tp) == CALL_EXPR | |
5618 | || TREE_CODE (*tp) == AGGR_INIT_EXPR) | |
5619 | { | |
5620 | if (EXPR_HAS_LOCATION (*tp)) | |
5621 | input_location = EXPR_LOCATION (*tp); | |
5622 | } | |
5623 | ||
5624 | if (!EXPR_P (*tp)) | |
5625 | *walk_subtrees = 0; | |
5626 | ||
5627 | return NULL_TREE; | |
5628 | } | |
8e007055 | 5629 | |
e079dced JM |
5630 | static void |
5631 | instantiate_constexpr_fns (tree t) | |
5632 | { | |
5633 | location_t loc = input_location; | |
5634 | cp_walk_tree_without_duplicates (&t, instantiate_cx_fn_r, NULL); | |
5635 | input_location = loc; | |
5636 | } | |
5637 | ||
8e007055 JJ |
5638 | /* Look for heap variables in the expression *TP. */ |
5639 | ||
5640 | static tree | |
5641 | find_heap_var_refs (tree *tp, int *walk_subtrees, void */*data*/) | |
5642 | { | |
5643 | if (VAR_P (*tp) | |
5644 | && (DECL_NAME (*tp) == heap_uninit_identifier | |
5645 | || DECL_NAME (*tp) == heap_identifier | |
5646 | || DECL_NAME (*tp) == heap_deleted_identifier)) | |
5647 | return *tp; | |
5648 | ||
5649 | if (TYPE_P (*tp)) | |
5650 | *walk_subtrees = 0; | |
5651 | return NULL_TREE; | |
5652 | } | |
5653 | ||
e4082611 | 5654 | /* ALLOW_NON_CONSTANT is false if T is required to be a constant expression. |
d4accef3 JM |
5655 | STRICT has the same sense as for constant_value_1: true if we only allow |
5656 | conforming C++ constant expressions, or false if we want a constant value | |
5657 | even if it doesn't conform. | |
13de99bc | 5658 | MANIFESTLY_CONST_EVAL is true if T is manifestly const-evaluated as |
8e007055 JJ |
5659 | per P0595 even when ALLOW_NON_CONSTANT is true. |
5660 | CONSTEXPR_DTOR is true when evaluating the dtor of a constexpr variable. | |
5661 | OBJECT must be non-NULL in that case. */ | |
e4082611 | 5662 | |
2d76680f | 5663 | static tree |
3e605b20 | 5664 | cxx_eval_outermost_constant_expr (tree t, bool allow_non_constant, |
e4082611 | 5665 | bool strict = true, |
13de99bc | 5666 | bool manifestly_const_eval = false, |
8e007055 | 5667 | bool constexpr_dtor = false, |
e4082611 | 5668 | tree object = NULL_TREE) |
2d76680f | 5669 | { |
8108ea30 JM |
5670 | auto_timevar time (TV_CONSTEXPR); |
5671 | ||
2d76680f PC |
5672 | bool non_constant_p = false; |
5673 | bool overflow_p = false; | |
39dce2b7 | 5674 | |
8e007055 JJ |
5675 | constexpr_global_ctx global_ctx; |
5676 | constexpr_ctx ctx = { &global_ctx, NULL, NULL, NULL, NULL, NULL, | |
5677 | allow_non_constant, strict, | |
13de99bc | 5678 | manifestly_const_eval || !allow_non_constant }; |
39dce2b7 | 5679 | |
3e605b20 | 5680 | tree type = initialized_type (t); |
3e605b20 | 5681 | tree r = t; |
4d0c18c6 | 5682 | if (VOID_TYPE_P (type)) |
8e007055 JJ |
5683 | { |
5684 | if (constexpr_dtor) | |
5685 | /* Used for destructors of array elements. */ | |
5686 | type = TREE_TYPE (object); | |
5687 | else | |
5688 | return t; | |
5689 | } | |
3e605b20 JM |
5690 | if (AGGREGATE_TYPE_P (type) || VECTOR_TYPE_P (type)) |
5691 | { | |
5692 | /* In C++14 an NSDMI can participate in aggregate initialization, | |
5693 | and can refer to the address of the object being initialized, so | |
5694 | we need to pass in the relevant VAR_DECL if we want to do the | |
5695 | evaluation in a single pass. The evaluation will dynamically | |
5696 | update ctx.values for the VAR_DECL. We use the same strategy | |
5697 | for C++11 constexpr constructors that refer to the object being | |
5698 | initialized. */ | |
8e007055 JJ |
5699 | if (constexpr_dtor) |
5700 | { | |
5701 | gcc_assert (object && VAR_P (object)); | |
5702 | gcc_assert (DECL_DECLARED_CONSTEXPR_P (object)); | |
5703 | gcc_assert (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (object)); | |
5704 | ctx.ctor = unshare_expr (DECL_INITIAL (object)); | |
5705 | TREE_READONLY (ctx.ctor) = false; | |
5706 | /* Temporarily force decl_really_constant_value to return false | |
5707 | for it, we want to use ctx.ctor for the current value instead. */ | |
5708 | DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (object) = false; | |
5709 | } | |
5710 | else | |
5711 | { | |
5712 | ctx.ctor = build_constructor (type, NULL); | |
5713 | CONSTRUCTOR_NO_CLEARING (ctx.ctor) = true; | |
5714 | } | |
60813a46 JM |
5715 | if (!object) |
5716 | { | |
5717 | if (TREE_CODE (t) == TARGET_EXPR) | |
5718 | object = TARGET_EXPR_SLOT (t); | |
5719 | else if (TREE_CODE (t) == AGGR_INIT_EXPR) | |
5720 | object = AGGR_INIT_EXPR_SLOT (t); | |
5721 | } | |
3e605b20 JM |
5722 | ctx.object = object; |
5723 | if (object) | |
5724 | gcc_assert (same_type_ignoring_top_level_qualifiers_p | |
5725 | (type, TREE_TYPE (object))); | |
5726 | if (object && DECL_P (object)) | |
8e007055 | 5727 | global_ctx.values.put (object, ctx.ctor); |
3e605b20 JM |
5728 | if (TREE_CODE (r) == TARGET_EXPR) |
5729 | /* Avoid creating another CONSTRUCTOR when we expand the | |
5730 | TARGET_EXPR. */ | |
5731 | r = TARGET_EXPR_INITIAL (r); | |
5732 | } | |
5733 | ||
e079dced | 5734 | instantiate_constexpr_fns (r); |
2b3ab879 | 5735 | r = cxx_eval_constant_expression (&ctx, r, |
5a804683 | 5736 | false, &non_constant_p, &overflow_p); |
2d76680f | 5737 | |
8e007055 JJ |
5738 | if (!constexpr_dtor) |
5739 | verify_constant (r, allow_non_constant, &non_constant_p, &overflow_p); | |
5740 | else | |
5741 | DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (object) = true; | |
2d76680f | 5742 | |
023d89c7 JM |
5743 | /* Mutable logic is a bit tricky: we want to allow initialization of |
5744 | constexpr variables with mutable members, but we can't copy those | |
5745 | members to another constexpr variable. */ | |
8e007055 | 5746 | if (TREE_CODE (r) == CONSTRUCTOR && CONSTRUCTOR_MUTABLE_POISON (r)) |
2d76680f | 5747 | { |
2d76680f | 5748 | if (!allow_non_constant) |
023d89c7 JM |
5749 | error ("%qE is not a constant expression because it refers to " |
5750 | "mutable subobjects of %qT", t, type); | |
2d76680f PC |
5751 | non_constant_p = true; |
5752 | } | |
5753 | ||
8e007055 | 5754 | if (TREE_CODE (r) == CONSTRUCTOR && CONSTRUCTOR_NO_CLEARING (r)) |
f64e0c02 JM |
5755 | { |
5756 | if (!allow_non_constant) | |
5757 | error ("%qE is not a constant expression because it refers to " | |
5758 | "an incompletely initialized variable", t); | |
5759 | TREE_CONSTANT (r) = false; | |
5760 | non_constant_p = true; | |
5761 | } | |
5762 | ||
8e007055 JJ |
5763 | if (!global_ctx.heap_vars.is_empty ()) |
5764 | { | |
5765 | tree heap_var = cp_walk_tree_without_duplicates (&r, find_heap_var_refs, | |
5766 | NULL); | |
5767 | unsigned int i; | |
5768 | if (heap_var) | |
5769 | { | |
5770 | if (!allow_non_constant && !non_constant_p) | |
5771 | error_at (DECL_SOURCE_LOCATION (heap_var), | |
5772 | "%qE is not a constant expression because it refers to " | |
5773 | "a result of %<operator new%>", t); | |
5774 | r = t; | |
5775 | non_constant_p = true; | |
5776 | } | |
5777 | FOR_EACH_VEC_ELT (global_ctx.heap_vars, i, heap_var) | |
5778 | if (DECL_NAME (heap_var) != heap_deleted_identifier) | |
5779 | { | |
5780 | if (!allow_non_constant && !non_constant_p) | |
5781 | error_at (DECL_SOURCE_LOCATION (heap_var), | |
5782 | "%qE is not a constant expression because allocated " | |
5783 | "storage has not been deallocated", t); | |
5784 | r = t; | |
5785 | non_constant_p = true; | |
5786 | } | |
5787 | } | |
5788 | ||
2d76680f PC |
5789 | /* Technically we should check this for all subexpressions, but that |
5790 | runs into problems with our internal representation of pointer | |
5791 | subtraction and the 5.19 rules are still in flux. */ | |
5792 | if (CONVERT_EXPR_CODE_P (TREE_CODE (r)) | |
5793 | && ARITHMETIC_TYPE_P (TREE_TYPE (r)) | |
5794 | && TREE_CODE (TREE_OPERAND (r, 0)) == ADDR_EXPR) | |
5795 | { | |
5796 | if (!allow_non_constant) | |
5797 | error ("conversion from pointer type %qT " | |
64d6d399 | 5798 | "to arithmetic type %qT in a constant expression", |
2d76680f PC |
5799 | TREE_TYPE (TREE_OPERAND (r, 0)), TREE_TYPE (r)); |
5800 | non_constant_p = true; | |
5801 | } | |
5802 | ||
5803 | if (!non_constant_p && overflow_p) | |
5804 | non_constant_p = true; | |
5805 | ||
56cfb596 PP |
5806 | /* Unshare the result unless it's a CONSTRUCTOR in which case it's already |
5807 | unshared. */ | |
5808 | bool should_unshare = true; | |
5809 | if (r == t || TREE_CODE (r) == CONSTRUCTOR) | |
5810 | should_unshare = false; | |
5811 | ||
2d76680f PC |
5812 | if (non_constant_p && !allow_non_constant) |
5813 | return error_mark_node; | |
8e007055 JJ |
5814 | else if (constexpr_dtor) |
5815 | return r; | |
2d76680f PC |
5816 | else if (non_constant_p && TREE_CONSTANT (r)) |
5817 | { | |
e4082611 JJ |
5818 | /* If __builtin_is_constant_evaluated () was evaluated to true |
5819 | and the result is not a valid constant expression, we need to | |
5820 | punt. */ | |
13de99bc | 5821 | if (manifestly_const_eval) |
e4082611 | 5822 | return cxx_eval_outermost_constant_expr (t, true, strict, |
8e007055 | 5823 | false, false, object); |
eddd715c JM |
5824 | /* This isn't actually constant, so unset TREE_CONSTANT. |
5825 | Don't clear TREE_CONSTANT on ADDR_EXPR, as the middle-end requires | |
5826 | it to be set if it is invariant address, even when it is not | |
5827 | a valid C++ constant expression. Wrap it with a NOP_EXPR | |
5828 | instead. */ | |
5829 | if (EXPR_P (r) && TREE_CODE (r) != ADDR_EXPR) | |
2d76680f PC |
5830 | r = copy_node (r); |
5831 | else if (TREE_CODE (r) == CONSTRUCTOR) | |
5832 | r = build1 (VIEW_CONVERT_EXPR, TREE_TYPE (r), r); | |
5833 | else | |
5834 | r = build_nop (TREE_TYPE (r), r); | |
5835 | TREE_CONSTANT (r) = false; | |
5836 | } | |
5dab8b11 | 5837 | else if (non_constant_p) |
2d76680f PC |
5838 | return t; |
5839 | ||
56cfb596 PP |
5840 | if (should_unshare) |
5841 | r = unshare_expr (r); | |
5842 | ||
2d76680f PC |
5843 | if (TREE_CODE (r) == CONSTRUCTOR && CLASS_TYPE_P (TREE_TYPE (r))) |
5844 | { | |
5dab8b11 | 5845 | r = adjust_temp_type (type, r); |
2d76680f PC |
5846 | if (TREE_CODE (t) == TARGET_EXPR |
5847 | && TARGET_EXPR_INITIAL (t) == r) | |
5848 | return t; | |
5dab8b11 | 5849 | else if (TREE_CODE (t) != CONSTRUCTOR) |
2d76680f | 5850 | { |
8e007055 | 5851 | r = get_target_expr_sfinae (r, tf_warning_or_error | tf_no_cleanup); |
2d76680f | 5852 | TREE_CONSTANT (r) = true; |
2d76680f PC |
5853 | } |
5854 | } | |
5dab8b11 JM |
5855 | |
5856 | return r; | |
2d76680f PC |
5857 | } |
5858 | ||
2d76680f PC |
5859 | /* If T represents a constant expression returns its reduced value. |
5860 | Otherwise return error_mark_node. If T is dependent, then | |
5861 | return NULL. */ | |
5862 | ||
5863 | tree | |
3e605b20 | 5864 | cxx_constant_value (tree t, tree decl) |
2d76680f | 5865 | { |
8e007055 JJ |
5866 | return cxx_eval_outermost_constant_expr (t, false, true, true, false, decl); |
5867 | } | |
5868 | ||
5869 | /* Like cxx_constant_value, but used for evaluation of constexpr destructors | |
5870 | of constexpr variables. The actual initializer of DECL is not modified. */ | |
5871 | ||
5872 | void | |
5873 | cxx_constant_dtor (tree t, tree decl) | |
5874 | { | |
5875 | cxx_eval_outermost_constant_expr (t, false, true, true, true, decl); | |
2d76680f PC |
5876 | } |
5877 | ||
cda0a029 JM |
5878 | /* Helper routine for fold_simple function. Either return simplified |
5879 | expression T, otherwise NULL_TREE. | |
5880 | In contrast to cp_fully_fold, and to maybe_constant_value, we try to fold | |
5881 | even if we are within template-declaration. So be careful on call, as in | |
5882 | such case types can be undefined. */ | |
5883 | ||
5884 | static tree | |
5885 | fold_simple_1 (tree t) | |
5886 | { | |
5887 | tree op1; | |
5888 | enum tree_code code = TREE_CODE (t); | |
5889 | ||
5890 | switch (code) | |
5891 | { | |
5892 | case INTEGER_CST: | |
5893 | case REAL_CST: | |
5894 | case VECTOR_CST: | |
5895 | case FIXED_CST: | |
5896 | case COMPLEX_CST: | |
5897 | return t; | |
5898 | ||
5899 | case SIZEOF_EXPR: | |
5900 | return fold_sizeof_expr (t); | |
5901 | ||
5902 | case ABS_EXPR: | |
e28fadbc | 5903 | case ABSU_EXPR: |
cda0a029 JM |
5904 | case CONJ_EXPR: |
5905 | case REALPART_EXPR: | |
5906 | case IMAGPART_EXPR: | |
5907 | case NEGATE_EXPR: | |
5908 | case BIT_NOT_EXPR: | |
5909 | case TRUTH_NOT_EXPR: | |
5910 | case NOP_EXPR: | |
5911 | case VIEW_CONVERT_EXPR: | |
5912 | case CONVERT_EXPR: | |
5913 | case FLOAT_EXPR: | |
5914 | case FIX_TRUNC_EXPR: | |
5915 | case FIXED_CONVERT_EXPR: | |
5916 | case ADDR_SPACE_CONVERT_EXPR: | |
5917 | ||
5918 | op1 = TREE_OPERAND (t, 0); | |
5919 | ||
5920 | t = const_unop (code, TREE_TYPE (t), op1); | |
5921 | if (!t) | |
5922 | return NULL_TREE; | |
5923 | ||
5924 | if (CONVERT_EXPR_CODE_P (code) | |
5925 | && TREE_OVERFLOW_P (t) && !TREE_OVERFLOW_P (op1)) | |
5926 | TREE_OVERFLOW (t) = false; | |
5927 | return t; | |
5928 | ||
5929 | default: | |
5930 | return NULL_TREE; | |
5931 | } | |
5932 | } | |
5933 | ||
5934 | /* If T is a simple constant expression, returns its simplified value. | |
dba99244 | 5935 | Otherwise returns T. In contrast to maybe_constant_value we |
cda0a029 JM |
5936 | simplify only few operations on constant-expressions, and we don't |
5937 | try to simplify constexpressions. */ | |
5938 | ||
5939 | tree | |
5940 | fold_simple (tree t) | |
5941 | { | |
cda0a029 JM |
5942 | if (processing_template_decl) |
5943 | return t; | |
5944 | ||
dba99244 MP |
5945 | tree r = fold_simple_1 (t); |
5946 | if (r) | |
5947 | return r; | |
cda0a029 | 5948 | |
dba99244 | 5949 | return t; |
cda0a029 JM |
5950 | } |
5951 | ||
2d76680f PC |
5952 | /* If T is a constant expression, returns its reduced value. |
5953 | Otherwise, if T does not have TREE_CONSTANT set, returns T. | |
13de99bc JJ |
5954 | Otherwise, returns a version of T without TREE_CONSTANT. |
5955 | MANIFESTLY_CONST_EVAL is true if T is manifestly const-evaluated | |
5956 | as per P0595. */ | |
2d76680f | 5957 | |
8a87daca JM |
5958 | static GTY((deletable)) hash_map<tree, tree> *cv_cache; |
5959 | ||
5960 | tree | |
13de99bc | 5961 | maybe_constant_value (tree t, tree decl, bool manifestly_const_eval) |
2d76680f PC |
5962 | { |
5963 | tree r; | |
5964 | ||
a0ab7ccd | 5965 | if (!is_nondependent_constant_expression (t)) |
2d76680f PC |
5966 | { |
5967 | if (TREE_OVERFLOW_P (t)) | |
5968 | { | |
5969 | t = build_nop (TREE_TYPE (t), t); | |
5970 | TREE_CONSTANT (t) = false; | |
5971 | } | |
5972 | return t; | |
5973 | } | |
8a87daca JM |
5974 | else if (CONSTANT_CLASS_P (t)) |
5975 | /* No caching or evaluation needed. */ | |
5976 | return t; | |
5977 | ||
13de99bc | 5978 | if (manifestly_const_eval) |
8e007055 | 5979 | return cxx_eval_outermost_constant_expr (t, true, true, true, false, decl); |
13de99bc | 5980 | |
8a87daca JM |
5981 | if (cv_cache == NULL) |
5982 | cv_cache = hash_map<tree, tree>::create_ggc (101); | |
5983 | if (tree *cached = cv_cache->get (t)) | |
5984 | return *cached; | |
2d76680f | 5985 | |
8e007055 | 5986 | r = cxx_eval_outermost_constant_expr (t, true, true, false, false, decl); |
595278be MM |
5987 | gcc_checking_assert (r == t |
5988 | || CONVERT_EXPR_P (t) | |
5989 | || TREE_CODE (t) == VIEW_CONVERT_EXPR | |
5990 | || (TREE_CONSTANT (t) && !TREE_CONSTANT (r)) | |
5991 | || !cp_tree_equal (r, t)); | |
8a87daca | 5992 | cv_cache->put (t, r); |
2d76680f PC |
5993 | return r; |
5994 | } | |
5995 | ||
7a7ac32a PP |
5996 | /* Dispose of the whole CV_CACHE. */ |
5997 | ||
5998 | static void | |
5999 | clear_cv_cache (void) | |
6000 | { | |
6001 | if (cv_cache != NULL) | |
6002 | cv_cache->empty (); | |
6003 | } | |
6004 | ||
cb57504a | 6005 | /* Dispose of the whole CV_CACHE, FOLD_CACHE, and satisfaction caches. */ |
1e297006 MP |
6006 | |
6007 | void | |
cb57504a | 6008 | clear_cv_and_fold_caches (bool sat /*= true*/) |
1e297006 | 6009 | { |
7a7ac32a | 6010 | clear_cv_cache (); |
eba9e839 | 6011 | clear_fold_cache (); |
cb57504a JM |
6012 | if (sat) |
6013 | clear_satisfaction_cache (); | |
1e297006 MP |
6014 | } |
6015 | ||
a81c8e8c MP |
6016 | /* Internal function handling expressions in templates for |
6017 | fold_non_dependent_expr and fold_non_dependent_init. | |
6018 | ||
6019 | If we're in a template, but T isn't value dependent, simplify | |
6020 | it. We're supposed to treat: | |
6021 | ||
6022 | template <typename T> void f(T[1 + 1]); | |
6023 | template <typename T> void f(T[2]); | |
6024 | ||
6025 | as two declarations of the same function, for example. */ | |
6026 | ||
6027 | static tree | |
6028 | fold_non_dependent_expr_template (tree t, tsubst_flags_t complain, | |
6029 | bool manifestly_const_eval) | |
6030 | { | |
6031 | gcc_assert (processing_template_decl); | |
6032 | ||
6033 | if (is_nondependent_constant_expression (t)) | |
6034 | { | |
6035 | processing_template_decl_sentinel s; | |
6036 | t = instantiate_non_dependent_expr_internal (t, complain); | |
6037 | ||
6038 | if (type_unknown_p (t) || BRACE_ENCLOSED_INITIALIZER_P (t)) | |
6039 | { | |
6040 | if (TREE_OVERFLOW_P (t)) | |
6041 | { | |
6042 | t = build_nop (TREE_TYPE (t), t); | |
6043 | TREE_CONSTANT (t) = false; | |
6044 | } | |
6045 | return t; | |
6046 | } | |
6047 | ||
6048 | tree r = cxx_eval_outermost_constant_expr (t, true, true, | |
6049 | manifestly_const_eval, | |
8e007055 | 6050 | false, NULL_TREE); |
a81c8e8c MP |
6051 | /* cp_tree_equal looks through NOPs, so allow them. */ |
6052 | gcc_checking_assert (r == t | |
6053 | || CONVERT_EXPR_P (t) | |
6054 | || TREE_CODE (t) == VIEW_CONVERT_EXPR | |
6055 | || (TREE_CONSTANT (t) && !TREE_CONSTANT (r)) | |
6056 | || !cp_tree_equal (r, t)); | |
6057 | return r; | |
6058 | } | |
6059 | else if (TREE_OVERFLOW_P (t)) | |
6060 | { | |
6061 | t = build_nop (TREE_TYPE (t), t); | |
6062 | TREE_CONSTANT (t) = false; | |
6063 | } | |
6064 | ||
6065 | return t; | |
6066 | } | |
6067 | ||
234bef96 PC |
6068 | /* Like maybe_constant_value but first fully instantiate the argument. |
6069 | ||
6070 | Note: this is equivalent to instantiate_non_dependent_expr_sfinae | |
e56f6629 JM |
6071 | (t, complain) followed by maybe_constant_value but is more efficient, |
6072 | because it calls instantiation_dependent_expression_p and | |
6073 | potential_constant_expression at most once. | |
4cd3e7df | 6074 | The manifestly_const_eval argument is passed to maybe_constant_value. |
e56f6629 JM |
6075 | |
6076 | Callers should generally pass their active complain, or if they are in a | |
6077 | non-template, diagnosing context, they can use the default of | |
6078 | tf_warning_or_error. Callers that might be within a template context, don't | |
6079 | have a complain parameter, and aren't going to remember the result for long | |
6080 | (e.g. null_ptr_cst_p), can pass tf_none and deal with error_mark_node | |
6081 | appropriately. */ | |
234bef96 PC |
6082 | |
6083 | tree | |
e56f6629 | 6084 | fold_non_dependent_expr (tree t, |
4cd3e7df JJ |
6085 | tsubst_flags_t complain /* = tf_warning_or_error */, |
6086 | bool manifestly_const_eval /* = false */) | |
234bef96 PC |
6087 | { |
6088 | if (t == NULL_TREE) | |
6089 | return NULL_TREE; | |
6090 | ||
a81c8e8c MP |
6091 | if (processing_template_decl) |
6092 | return fold_non_dependent_expr_template (t, complain, | |
6093 | manifestly_const_eval); | |
234bef96 | 6094 | |
a81c8e8c MP |
6095 | return maybe_constant_value (t, NULL_TREE, manifestly_const_eval); |
6096 | } | |
234bef96 | 6097 | |
234bef96 | 6098 | |
a81c8e8c | 6099 | /* Like maybe_constant_init but first fully instantiate the argument. */ |
234bef96 | 6100 | |
a81c8e8c MP |
6101 | tree |
6102 | fold_non_dependent_init (tree t, | |
6103 | tsubst_flags_t complain /*=tf_warning_or_error*/, | |
6104 | bool manifestly_const_eval /*=false*/) | |
6105 | { | |
6106 | if (t == NULL_TREE) | |
6107 | return NULL_TREE; | |
6108 | ||
6109 | if (processing_template_decl) | |
6110 | { | |
6111 | t = fold_non_dependent_expr_template (t, complain, | |
6112 | manifestly_const_eval); | |
6113 | /* maybe_constant_init does this stripping, so do it here too. */ | |
6114 | if (TREE_CODE (t) == TARGET_EXPR) | |
234bef96 | 6115 | { |
a81c8e8c MP |
6116 | tree init = TARGET_EXPR_INITIAL (t); |
6117 | if (TREE_CODE (init) == CONSTRUCTOR) | |
6118 | t = init; | |
234bef96 PC |
6119 | } |
6120 | return t; | |
6121 | } | |
6122 | ||
a81c8e8c | 6123 | return maybe_constant_init (t, NULL_TREE, manifestly_const_eval); |
234bef96 PC |
6124 | } |
6125 | ||
2d76680f | 6126 | /* Like maybe_constant_value, but returns a CONSTRUCTOR directly, rather |
e4082611 JJ |
6127 | than wrapped in a TARGET_EXPR. |
6128 | ALLOW_NON_CONSTANT is false if T is required to be a constant expression. | |
13de99bc | 6129 | MANIFESTLY_CONST_EVAL is true if T is manifestly const-evaluated as |
e4082611 | 6130 | per P0595 even when ALLOW_NON_CONSTANT is true. */ |
2d76680f | 6131 | |
118cd6ba | 6132 | static tree |
e4082611 | 6133 | maybe_constant_init_1 (tree t, tree decl, bool allow_non_constant, |
13de99bc | 6134 | bool manifestly_const_eval) |
2d76680f | 6135 | { |
cda0a029 JM |
6136 | if (!t) |
6137 | return t; | |
2d76680f PC |
6138 | if (TREE_CODE (t) == EXPR_STMT) |
6139 | t = TREE_OPERAND (t, 0); | |
6140 | if (TREE_CODE (t) == CONVERT_EXPR | |
6141 | && VOID_TYPE_P (TREE_TYPE (t))) | |
6142 | t = TREE_OPERAND (t, 0); | |
60813a46 JM |
6143 | if (TREE_CODE (t) == INIT_EXPR) |
6144 | t = TREE_OPERAND (t, 1); | |
f64e0c02 JM |
6145 | if (TREE_CODE (t) == TARGET_EXPR) |
6146 | t = TARGET_EXPR_INITIAL (t); | |
a0ab7ccd | 6147 | if (!is_nondependent_static_init_expression (t)) |
69eb4fde | 6148 | /* Don't try to evaluate it. */; |
118cd6ba | 6149 | else if (CONSTANT_CLASS_P (t) && allow_non_constant) |
8a87daca | 6150 | /* No evaluation needed. */; |
69eb4fde | 6151 | else |
e4082611 | 6152 | t = cxx_eval_outermost_constant_expr (t, allow_non_constant, |
38295573 | 6153 | /*strict*/false, |
8e007055 | 6154 | manifestly_const_eval, false, decl); |
2d76680f PC |
6155 | if (TREE_CODE (t) == TARGET_EXPR) |
6156 | { | |
6157 | tree init = TARGET_EXPR_INITIAL (t); | |
6158 | if (TREE_CODE (init) == CONSTRUCTOR) | |
6159 | t = init; | |
6160 | } | |
6161 | return t; | |
6162 | } | |
6163 | ||
118cd6ba MP |
6164 | /* Wrapper for maybe_constant_init_1 which permits non constants. */ |
6165 | ||
6166 | tree | |
13de99bc | 6167 | maybe_constant_init (tree t, tree decl, bool manifestly_const_eval) |
118cd6ba | 6168 | { |
13de99bc | 6169 | return maybe_constant_init_1 (t, decl, true, manifestly_const_eval); |
118cd6ba MP |
6170 | } |
6171 | ||
6172 | /* Wrapper for maybe_constant_init_1 which does not permit non constants. */ | |
6173 | ||
6174 | tree | |
6175 | cxx_constant_init (tree t, tree decl) | |
6176 | { | |
e4082611 | 6177 | return maybe_constant_init_1 (t, decl, false, true); |
118cd6ba MP |
6178 | } |
6179 | ||
2d76680f PC |
6180 | #if 0 |
6181 | /* FIXME see ADDR_EXPR section in potential_constant_expression_1. */ | |
6182 | /* Return true if the object referred to by REF has automatic or thread | |
6183 | local storage. */ | |
6184 | ||
6185 | enum { ck_ok, ck_bad, ck_unknown }; | |
6186 | static int | |
6187 | check_automatic_or_tls (tree ref) | |
6188 | { | |
ef4bddc2 | 6189 | machine_mode mode; |
f37fac2b | 6190 | poly_int64 bitsize, bitpos; |
2d76680f PC |
6191 | tree offset; |
6192 | int volatilep = 0, unsignedp = 0; | |
6193 | tree decl = get_inner_reference (ref, &bitsize, &bitpos, &offset, | |
6194 | &mode, &unsignedp, &volatilep, false); | |
6195 | duration_kind dk; | |
6196 | ||
6197 | /* If there isn't a decl in the middle, we don't know the linkage here, | |
6198 | and this isn't a constant expression anyway. */ | |
6199 | if (!DECL_P (decl)) | |
6200 | return ck_unknown; | |
6201 | dk = decl_storage_duration (decl); | |
6202 | return (dk == dk_auto || dk == dk_thread) ? ck_bad : ck_ok; | |
6203 | } | |
6204 | #endif | |
6205 | ||
c7a53bdb JJ |
6206 | /* Data structure for passing data from potential_constant_expression_1 |
6207 | to check_for_return_continue via cp_walk_tree. */ | |
6208 | struct check_for_return_continue_data { | |
6209 | hash_set<tree> *pset; | |
6210 | tree continue_stmt; | |
6211 | }; | |
6212 | ||
6213 | /* Helper function for potential_constant_expression_1 SWITCH_STMT handling, | |
6214 | called through cp_walk_tree. Return the first RETURN_EXPR found, or note | |
6215 | the first CONTINUE_STMT if RETURN_EXPR is not found. */ | |
6216 | static tree | |
6217 | check_for_return_continue (tree *tp, int *walk_subtrees, void *data) | |
6218 | { | |
6219 | tree t = *tp, s; | |
6220 | check_for_return_continue_data *d = (check_for_return_continue_data *) data; | |
6221 | switch (TREE_CODE (t)) | |
6222 | { | |
6223 | case RETURN_EXPR: | |
6224 | return t; | |
6225 | ||
6226 | case CONTINUE_STMT: | |
6227 | if (d->continue_stmt == NULL_TREE) | |
6228 | d->continue_stmt = t; | |
6229 | break; | |
6230 | ||
6231 | #define RECUR(x) \ | |
6232 | if (tree r = cp_walk_tree (&x, check_for_return_continue, data, \ | |
6233 | d->pset)) \ | |
6234 | return r | |
6235 | ||
6236 | /* For loops, walk subtrees manually, so that continue stmts found | |
6237 | inside of the bodies of the loops are ignored. */ | |
6238 | case DO_STMT: | |
6239 | *walk_subtrees = 0; | |
6240 | RECUR (DO_COND (t)); | |
6241 | s = d->continue_stmt; | |
6242 | RECUR (DO_BODY (t)); | |
6243 | d->continue_stmt = s; | |
6244 | break; | |
6245 | ||
6246 | case WHILE_STMT: | |
6247 | *walk_subtrees = 0; | |
6248 | RECUR (WHILE_COND (t)); | |
6249 | s = d->continue_stmt; | |
6250 | RECUR (WHILE_BODY (t)); | |
6251 | d->continue_stmt = s; | |
6252 | break; | |
6253 | ||
6254 | case FOR_STMT: | |
6255 | *walk_subtrees = 0; | |
6256 | RECUR (FOR_INIT_STMT (t)); | |
6257 | RECUR (FOR_COND (t)); | |
6258 | RECUR (FOR_EXPR (t)); | |
6259 | s = d->continue_stmt; | |
6260 | RECUR (FOR_BODY (t)); | |
6261 | d->continue_stmt = s; | |
6262 | break; | |
6263 | ||
6264 | case RANGE_FOR_STMT: | |
6265 | *walk_subtrees = 0; | |
6266 | RECUR (RANGE_FOR_EXPR (t)); | |
6267 | s = d->continue_stmt; | |
6268 | RECUR (RANGE_FOR_BODY (t)); | |
6269 | d->continue_stmt = s; | |
6270 | break; | |
6271 | #undef RECUR | |
6272 | ||
6273 | case STATEMENT_LIST: | |
6274 | case CONSTRUCTOR: | |
6275 | break; | |
6276 | ||
6277 | default: | |
6278 | if (!EXPR_P (t)) | |
6279 | *walk_subtrees = 0; | |
6280 | break; | |
6281 | } | |
6282 | ||
6283 | return NULL_TREE; | |
6284 | } | |
6285 | ||
2d76680f PC |
6286 | /* Return true if T denotes a potentially constant expression. Issue |
6287 | diagnostic as appropriate under control of FLAGS. If WANT_RVAL is true, | |
a0ab7ccd JM |
6288 | an lvalue-rvalue conversion is implied. If NOW is true, we want to |
6289 | consider the expression in the current context, independent of constexpr | |
6290 | substitution. | |
2d76680f PC |
6291 | |
6292 | C++0x [expr.const] used to say | |
6293 | ||
6294 | 6 An expression is a potential constant expression if it is | |
6295 | a constant expression where all occurrences of function | |
6296 | parameters are replaced by arbitrary constant expressions | |
6297 | of the appropriate type. | |
6298 | ||
6299 | 2 A conditional expression is a constant expression unless it | |
6300 | involves one of the following as a potentially evaluated | |
6301 | subexpression (3.2), but subexpressions of logical AND (5.14), | |
6302 | logical OR (5.15), and conditional (5.16) operations that are | |
6303 | not evaluated are not considered. */ | |
6304 | ||
6305 | static bool | |
a0ab7ccd | 6306 | potential_constant_expression_1 (tree t, bool want_rval, bool strict, bool now, |
3075affd | 6307 | tsubst_flags_t flags, tree *jump_target) |
2d76680f | 6308 | { |
a0ab7ccd | 6309 | #define RECUR(T,RV) \ |
3075affd | 6310 | potential_constant_expression_1 ((T), (RV), strict, now, flags, jump_target) |
a0ab7ccd | 6311 | |
2d76680f PC |
6312 | enum { any = false, rval = true }; |
6313 | int i; | |
6314 | tree tmp; | |
6315 | ||
6316 | if (t == error_mark_node) | |
6317 | return false; | |
6318 | if (t == NULL_TREE) | |
6319 | return true; | |
f9d0ca40 | 6320 | location_t loc = cp_expr_loc_or_input_loc (t); |
3075affd JM |
6321 | |
6322 | if (*jump_target) | |
6323 | /* If we are jumping, ignore everything. This is simpler than the | |
6324 | cxx_eval_constant_expression handling because we only need to be | |
6325 | conservatively correct, and we don't necessarily have a constant value | |
6326 | available, so we don't bother with switch tracking. */ | |
6327 | return true; | |
6328 | ||
3c393a2c | 6329 | if (TREE_THIS_VOLATILE (t) && want_rval) |
2d76680f PC |
6330 | { |
6331 | if (flags & tf_error) | |
3c393a2c MP |
6332 | error_at (loc, "lvalue-to-rvalue conversion of a volatile lvalue " |
6333 | "%qE with type %qT", t, TREE_TYPE (t)); | |
2d76680f PC |
6334 | return false; |
6335 | } | |
6336 | if (CONSTANT_CLASS_P (t)) | |
6337 | return true; | |
7dc2b4a2 JM |
6338 | if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_TYPED) |
6339 | && TREE_TYPE (t) == error_mark_node) | |
6340 | return false; | |
2d76680f PC |
6341 | |
6342 | switch (TREE_CODE (t)) | |
6343 | { | |
6344 | case FUNCTION_DECL: | |
6345 | case BASELINK: | |
6346 | case TEMPLATE_DECL: | |
6347 | case OVERLOAD: | |
6348 | case TEMPLATE_ID_EXPR: | |
6349 | case LABEL_DECL: | |
6350 | case LABEL_EXPR: | |
60813a46 | 6351 | case CASE_LABEL_EXPR: |
2d76680f PC |
6352 | case CONST_DECL: |
6353 | case SIZEOF_EXPR: | |
6354 | case ALIGNOF_EXPR: | |
6355 | case OFFSETOF_EXPR: | |
6356 | case NOEXCEPT_EXPR: | |
6357 | case TEMPLATE_PARM_INDEX: | |
6358 | case TRAIT_EXPR: | |
6359 | case IDENTIFIER_NODE: | |
6360 | case USERDEF_LITERAL: | |
6361 | /* We can see a FIELD_DECL in a pointer-to-member expression. */ | |
6362 | case FIELD_DECL: | |
cda0a029 | 6363 | case RESULT_DECL: |
2d76680f | 6364 | case USING_DECL: |
60813a46 | 6365 | case USING_STMT: |
3e605b20 | 6366 | case PLACEHOLDER_EXPR: |
971e17ff | 6367 | case REQUIRES_EXPR: |
98e5a19a | 6368 | case STATIC_ASSERT: |
96a95ac1 | 6369 | case DEBUG_BEGIN_STMT: |
2d76680f PC |
6370 | return true; |
6371 | ||
3075affd JM |
6372 | case RETURN_EXPR: |
6373 | if (!RECUR (TREE_OPERAND (t, 0), any)) | |
6374 | return false; | |
6375 | /* FALLTHROUGH */ | |
6376 | ||
6377 | case BREAK_STMT: | |
6378 | case CONTINUE_STMT: | |
6379 | *jump_target = t; | |
6380 | return true; | |
6381 | ||
a0ab7ccd JM |
6382 | case PARM_DECL: |
6383 | if (now) | |
6384 | { | |
6385 | if (flags & tf_error) | |
6386 | error ("%qE is not a constant expression", t); | |
6387 | return false; | |
6388 | } | |
6389 | return true; | |
6390 | ||
2d76680f PC |
6391 | case AGGR_INIT_EXPR: |
6392 | case CALL_EXPR: | |
6393 | /* -- an invocation of a function other than a constexpr function | |
6394 | or a constexpr constructor. */ | |
6395 | { | |
6396 | tree fun = get_function_named_in_call (t); | |
6397 | const int nargs = call_expr_nargs (t); | |
6398 | i = 0; | |
6399 | ||
60813a46 JM |
6400 | if (fun == NULL_TREE) |
6401 | { | |
44a845ca MS |
6402 | /* Reset to allow the function to continue past the end |
6403 | of the block below. Otherwise return early. */ | |
6404 | bool bail = true; | |
6405 | ||
35228ac7 JJ |
6406 | if (TREE_CODE (t) == CALL_EXPR |
6407 | && CALL_EXPR_FN (t) == NULL_TREE) | |
6408 | switch (CALL_EXPR_IFN (t)) | |
6409 | { | |
6410 | /* These should be ignored, they are optimized away from | |
6411 | constexpr functions. */ | |
6412 | case IFN_UBSAN_NULL: | |
6413 | case IFN_UBSAN_BOUNDS: | |
6414 | case IFN_UBSAN_VPTR: | |
81fea426 | 6415 | case IFN_FALLTHROUGH: |
35228ac7 | 6416 | return true; |
44a845ca MS |
6417 | |
6418 | case IFN_ADD_OVERFLOW: | |
6419 | case IFN_SUB_OVERFLOW: | |
6420 | case IFN_MUL_OVERFLOW: | |
e16f1cc7 | 6421 | case IFN_LAUNDER: |
d8fcab68 | 6422 | case IFN_VEC_CONVERT: |
44a845ca | 6423 | bail = false; |
d8fcab68 | 6424 | break; |
44a845ca | 6425 | |
35228ac7 JJ |
6426 | default: |
6427 | break; | |
6428 | } | |
44a845ca MS |
6429 | |
6430 | if (bail) | |
6431 | { | |
6432 | /* fold_call_expr can't do anything with IFN calls. */ | |
6433 | if (flags & tf_error) | |
e40b6fc7 | 6434 | error_at (loc, "call to internal function %qE", t); |
44a845ca MS |
6435 | return false; |
6436 | } | |
60813a46 | 6437 | } |
44a845ca MS |
6438 | |
6439 | if (fun && is_overloaded_fn (fun)) | |
2d76680f PC |
6440 | { |
6441 | if (TREE_CODE (fun) == FUNCTION_DECL) | |
6442 | { | |
6443 | if (builtin_valid_in_constant_expr_p (fun)) | |
6444 | return true; | |
6445 | if (!DECL_DECLARED_CONSTEXPR_P (fun) | |
6446 | /* Allow any built-in function; if the expansion | |
6447 | isn't constant, we'll deal with that then. */ | |
8e007055 JJ |
6448 | && !fndecl_built_in_p (fun) |
6449 | /* In C++2a, replaceable global allocation functions | |
6450 | are constant expressions. */ | |
6451 | && !cxx_replaceable_global_alloc_fn (fun)) | |
2d76680f PC |
6452 | { |
6453 | if (flags & tf_error) | |
6454 | { | |
84fa214d | 6455 | error_at (loc, "call to non-%<constexpr%> function %qD", |
e40b6fc7 | 6456 | fun); |
2d76680f PC |
6457 | explain_invalid_constexpr_fn (fun); |
6458 | } | |
6459 | return false; | |
6460 | } | |
6461 | /* A call to a non-static member function takes the address | |
6462 | of the object as the first argument. But in a constant | |
6463 | expression the address will be folded away, so look | |
6464 | through it now. */ | |
6465 | if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fun) | |
6466 | && !DECL_CONSTRUCTOR_P (fun)) | |
6467 | { | |
6468 | tree x = get_nth_callarg (t, 0); | |
6469 | if (is_this_parameter (x)) | |
3e605b20 | 6470 | return true; |
a0ab7ccd JM |
6471 | /* Don't require an immediately constant value, as |
6472 | constexpr substitution might not use the value. */ | |
6473 | bool sub_now = false; | |
6474 | if (!potential_constant_expression_1 (x, rval, strict, | |
3075affd JM |
6475 | sub_now, flags, |
6476 | jump_target)) | |
2d76680f PC |
6477 | return false; |
6478 | i = 1; | |
6479 | } | |
6480 | } | |
6481 | else | |
6482 | { | |
69eb4fde | 6483 | if (!RECUR (fun, true)) |
2d76680f PC |
6484 | return false; |
6485 | fun = get_first_fn (fun); | |
6486 | } | |
6487 | /* Skip initial arguments to base constructors. */ | |
6488 | if (DECL_BASE_CONSTRUCTOR_P (fun)) | |
6489 | i = num_artificial_parms_for (fun); | |
6490 | fun = DECL_ORIGIN (fun); | |
6491 | } | |
44a845ca | 6492 | else if (fun) |
2d76680f | 6493 | { |
69eb4fde | 6494 | if (RECUR (fun, rval)) |
2d76680f PC |
6495 | /* Might end up being a constant function pointer. */; |
6496 | else | |
6497 | return false; | |
6498 | } | |
6499 | for (; i < nargs; ++i) | |
6500 | { | |
6501 | tree x = get_nth_callarg (t, i); | |
c3c29ba5 JM |
6502 | /* In a template, reference arguments haven't been converted to |
6503 | REFERENCE_TYPE and we might not even know if the parameter | |
6504 | is a reference, so accept lvalue constants too. */ | |
6505 | bool rv = processing_template_decl ? any : rval; | |
a0ab7ccd JM |
6506 | /* Don't require an immediately constant value, as constexpr |
6507 | substitution might not use the value of the argument. */ | |
6508 | bool sub_now = false; | |
6509 | if (!potential_constant_expression_1 (x, rv, strict, | |
3075affd | 6510 | sub_now, flags, jump_target)) |
2d76680f PC |
6511 | return false; |
6512 | } | |
6513 | return true; | |
6514 | } | |
6515 | ||
6516 | case NON_LVALUE_EXPR: | |
6517 | /* -- an lvalue-to-rvalue conversion (4.1) unless it is applied to | |
6518 | -- an lvalue of integral type that refers to a non-volatile | |
6519 | const variable or static data member initialized with | |
6520 | constant expressions, or | |
6521 | ||
6522 | -- an lvalue of literal type that refers to non-volatile | |
6523 | object defined with constexpr, or that refers to a | |
6524 | sub-object of such an object; */ | |
69eb4fde | 6525 | return RECUR (TREE_OPERAND (t, 0), rval); |
2d76680f PC |
6526 | |
6527 | case VAR_DECL: | |
70f40fea | 6528 | if (DECL_HAS_VALUE_EXPR_P (t)) |
c1051bf7 | 6529 | { |
68ad1bf7 | 6530 | if (now && is_normal_capture_proxy (t)) |
c1051bf7 JM |
6531 | { |
6532 | /* -- in a lambda-expression, a reference to this or to a | |
6533 | variable with automatic storage duration defined outside that | |
6534 | lambda-expression, where the reference would be an | |
6535 | odr-use. */ | |
6536 | if (flags & tf_error) | |
6537 | { | |
6538 | tree cap = DECL_CAPTURED_VARIABLE (t); | |
6539 | error ("lambda capture of %qE is not a constant expression", | |
6540 | cap); | |
6541 | if (!want_rval && decl_constant_var_p (cap)) | |
6542 | inform (input_location, "because it is used as a glvalue"); | |
6543 | } | |
6544 | return false; | |
6545 | } | |
6546 | return RECUR (DECL_VALUE_EXPR (t), rval); | |
6547 | } | |
69eb4fde | 6548 | if (want_rval |
98e5a19a | 6549 | && !var_in_maybe_constexpr_fn (t) |
7dc2b4a2 | 6550 | && !type_dependent_expression_p (t) |
4b691b13 | 6551 | && !decl_maybe_constant_var_p (t) |
69eb4fde JM |
6552 | && (strict |
6553 | || !CP_TYPE_CONST_NON_VOLATILE_P (TREE_TYPE (t)) | |
4b691b13 JM |
6554 | || (DECL_INITIAL (t) |
6555 | && !DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (t))) | |
7dc2b4a2 | 6556 | && COMPLETE_TYPE_P (TREE_TYPE (t)) |
dbcd32f8 | 6557 | && !is_really_empty_class (TREE_TYPE (t), /*ignore_vptr*/false)) |
2d76680f PC |
6558 | { |
6559 | if (flags & tf_error) | |
6560 | non_const_var_error (t); | |
6561 | return false; | |
6562 | } | |
6563 | return true; | |
6564 | ||
6565 | case NOP_EXPR: | |
ed3ea9f2 JJ |
6566 | if (REINTERPRET_CAST_P (t)) |
6567 | { | |
6568 | if (flags & tf_error) | |
a9c697b8 | 6569 | error_at (loc, "%<reinterpret_cast%> is not a constant expression"); |
ed3ea9f2 JJ |
6570 | return false; |
6571 | } | |
6572 | /* FALLTHRU */ | |
2d76680f PC |
6573 | case CONVERT_EXPR: |
6574 | case VIEW_CONVERT_EXPR: | |
6575 | /* -- a reinterpret_cast. FIXME not implemented, and this rule | |
6576 | may change to something more specific to type-punning (DR 1312). */ | |
6577 | { | |
6578 | tree from = TREE_OPERAND (t, 0); | |
dfd7fdca DM |
6579 | if (location_wrapper_p (t)) |
6580 | return (RECUR (from, want_rval)); | |
6581 | if (INDIRECT_TYPE_P (TREE_TYPE (t))) | |
2d76680f | 6582 | { |
dfd7fdca DM |
6583 | STRIP_ANY_LOCATION_WRAPPER (from); |
6584 | if (TREE_CODE (from) == INTEGER_CST | |
6585 | && !integer_zerop (from)) | |
6586 | { | |
6587 | if (flags & tf_error) | |
a9c697b8 MS |
6588 | error_at (loc, |
6589 | "%<reinterpret_cast%> from integer to pointer"); | |
dfd7fdca DM |
6590 | return false; |
6591 | } | |
2d76680f | 6592 | } |
69eb4fde | 6593 | return (RECUR (from, TREE_CODE (t) != VIEW_CONVERT_EXPR)); |
2d76680f PC |
6594 | } |
6595 | ||
be845b04 JJ |
6596 | case ADDRESSOF_EXPR: |
6597 | /* This is like ADDR_EXPR, except it won't form pointer-to-member. */ | |
6598 | t = TREE_OPERAND (t, 0); | |
6599 | goto handle_addr_expr; | |
6600 | ||
2d76680f PC |
6601 | case ADDR_EXPR: |
6602 | /* -- a unary operator & that is applied to an lvalue that | |
6603 | designates an object with thread or automatic storage | |
6604 | duration; */ | |
6605 | t = TREE_OPERAND (t, 0); | |
6606 | ||
6607 | if (TREE_CODE (t) == OFFSET_REF && PTRMEM_OK_P (t)) | |
6608 | /* A pointer-to-member constant. */ | |
6609 | return true; | |
6610 | ||
be845b04 | 6611 | handle_addr_expr: |
2d76680f PC |
6612 | #if 0 |
6613 | /* FIXME adjust when issue 1197 is fully resolved. For now don't do | |
6614 | any checking here, as we might dereference the pointer later. If | |
6615 | we remove this code, also remove check_automatic_or_tls. */ | |
6616 | i = check_automatic_or_tls (t); | |
6617 | if (i == ck_ok) | |
6618 | return true; | |
6619 | if (i == ck_bad) | |
6620 | { | |
6621 | if (flags & tf_error) | |
6622 | error ("address-of an object %qE with thread local or " | |
6623 | "automatic storage is not a constant expression", t); | |
6624 | return false; | |
6625 | } | |
6626 | #endif | |
69eb4fde | 6627 | return RECUR (t, any); |
2d76680f | 6628 | |
dc8d2d00 JM |
6629 | case REALPART_EXPR: |
6630 | case IMAGPART_EXPR: | |
2d76680f PC |
6631 | case COMPONENT_REF: |
6632 | case BIT_FIELD_REF: | |
6633 | case ARROW_EXPR: | |
6634 | case OFFSET_REF: | |
6635 | /* -- a class member access unless its postfix-expression is | |
6636 | of literal type or of pointer to literal type. */ | |
6637 | /* This test would be redundant, as it follows from the | |
6638 | postfix-expression being a potential constant expression. */ | |
19dedccf JM |
6639 | if (type_unknown_p (t)) |
6640 | return true; | |
69eb4fde | 6641 | return RECUR (TREE_OPERAND (t, 0), want_rval); |
2d76680f PC |
6642 | |
6643 | case EXPR_PACK_EXPANSION: | |
69eb4fde | 6644 | return RECUR (PACK_EXPANSION_PATTERN (t), want_rval); |
2d76680f PC |
6645 | |
6646 | case INDIRECT_REF: | |
6647 | { | |
6648 | tree x = TREE_OPERAND (t, 0); | |
6649 | STRIP_NOPS (x); | |
948d0d91 | 6650 | if (is_this_parameter (x) && !is_capture_proxy (x)) |
2d76680f | 6651 | { |
5d4e573b | 6652 | if (!var_in_maybe_constexpr_fn (x)) |
2d76680f PC |
6653 | { |
6654 | if (flags & tf_error) | |
e40b6fc7 | 6655 | error_at (loc, "use of %<this%> in a constant expression"); |
2d76680f PC |
6656 | return false; |
6657 | } | |
2d76680f PC |
6658 | return true; |
6659 | } | |
69eb4fde | 6660 | return RECUR (x, rval); |
2d76680f PC |
6661 | } |
6662 | ||
60813a46 JM |
6663 | case STATEMENT_LIST: |
6664 | { | |
6665 | tree_stmt_iterator i; | |
6666 | for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i)) | |
6667 | { | |
69eb4fde | 6668 | if (!RECUR (tsi_stmt (i), any)) |
60813a46 JM |
6669 | return false; |
6670 | } | |
6671 | return true; | |
6672 | } | |
6673 | break; | |
6674 | ||
6675 | case MODIFY_EXPR: | |
6676 | if (cxx_dialect < cxx14) | |
6677 | goto fail; | |
69eb4fde | 6678 | if (!RECUR (TREE_OPERAND (t, 0), any)) |
60813a46 | 6679 | return false; |
8e007055 JJ |
6680 | /* Just ignore clobbers. */ |
6681 | if (TREE_CLOBBER_P (TREE_OPERAND (t, 1))) | |
6682 | return true; | |
69eb4fde | 6683 | if (!RECUR (TREE_OPERAND (t, 1), rval)) |
60813a46 JM |
6684 | return false; |
6685 | return true; | |
6686 | ||
6687 | case MODOP_EXPR: | |
6688 | if (cxx_dialect < cxx14) | |
6689 | goto fail; | |
69eb4fde | 6690 | if (!RECUR (TREE_OPERAND (t, 0), rval)) |
60813a46 | 6691 | return false; |
69eb4fde | 6692 | if (!RECUR (TREE_OPERAND (t, 2), rval)) |
60813a46 JM |
6693 | return false; |
6694 | return true; | |
6695 | ||
60813a46 | 6696 | case DO_STMT: |
69eb4fde | 6697 | if (!RECUR (DO_COND (t), rval)) |
60813a46 | 6698 | return false; |
69eb4fde | 6699 | if (!RECUR (DO_BODY (t), any)) |
60813a46 | 6700 | return false; |
3075affd JM |
6701 | if (breaks (jump_target) || continues (jump_target)) |
6702 | *jump_target = NULL_TREE; | |
60813a46 JM |
6703 | return true; |
6704 | ||
6705 | case FOR_STMT: | |
69eb4fde | 6706 | if (!RECUR (FOR_INIT_STMT (t), any)) |
60813a46 | 6707 | return false; |
8e9558f0 MP |
6708 | tmp = FOR_COND (t); |
6709 | if (!RECUR (tmp, rval)) | |
60813a46 | 6710 | return false; |
8e9558f0 MP |
6711 | if (tmp) |
6712 | { | |
6713 | if (!processing_template_decl) | |
6714 | tmp = cxx_eval_outermost_constant_expr (tmp, true); | |
a385474c MP |
6715 | /* If we couldn't evaluate the condition, it might not ever be |
6716 | true. */ | |
6717 | if (!integer_onep (tmp)) | |
8e9558f0 MP |
6718 | return true; |
6719 | } | |
69eb4fde | 6720 | if (!RECUR (FOR_EXPR (t), any)) |
60813a46 | 6721 | return false; |
69eb4fde | 6722 | if (!RECUR (FOR_BODY (t), any)) |
60813a46 | 6723 | return false; |
3075affd JM |
6724 | if (breaks (jump_target) || continues (jump_target)) |
6725 | *jump_target = NULL_TREE; | |
60813a46 JM |
6726 | return true; |
6727 | ||
98e5a19a | 6728 | case RANGE_FOR_STMT: |
8112667c MP |
6729 | if (!RECUR (RANGE_FOR_INIT_STMT (t), any)) |
6730 | return false; | |
98e5a19a JM |
6731 | if (!RECUR (RANGE_FOR_EXPR (t), any)) |
6732 | return false; | |
6733 | if (!RECUR (RANGE_FOR_BODY (t), any)) | |
6734 | return false; | |
3075affd JM |
6735 | if (breaks (jump_target) || continues (jump_target)) |
6736 | *jump_target = NULL_TREE; | |
98e5a19a JM |
6737 | return true; |
6738 | ||
60813a46 | 6739 | case WHILE_STMT: |
8e9558f0 MP |
6740 | tmp = WHILE_COND (t); |
6741 | if (!RECUR (tmp, rval)) | |
60813a46 | 6742 | return false; |
8e9558f0 MP |
6743 | if (!processing_template_decl) |
6744 | tmp = cxx_eval_outermost_constant_expr (tmp, true); | |
a385474c MP |
6745 | /* If we couldn't evaluate the condition, it might not ever be true. */ |
6746 | if (!integer_onep (tmp)) | |
8e9558f0 | 6747 | return true; |
69eb4fde | 6748 | if (!RECUR (WHILE_BODY (t), any)) |
60813a46 | 6749 | return false; |
3075affd JM |
6750 | if (breaks (jump_target) || continues (jump_target)) |
6751 | *jump_target = NULL_TREE; | |
60813a46 JM |
6752 | return true; |
6753 | ||
6754 | case SWITCH_STMT: | |
69eb4fde | 6755 | if (!RECUR (SWITCH_STMT_COND (t), rval)) |
60813a46 | 6756 | return false; |
ce965730 | 6757 | /* FIXME we don't check SWITCH_STMT_BODY currently, because even |
c7a53bdb JJ |
6758 | unreachable labels would be checked and it is enough if there is |
6759 | a single switch cond value for which it is a valid constant | |
6760 | expression. We need to check if there are any RETURN_EXPRs | |
6761 | or CONTINUE_STMTs inside of the body though, as in that case | |
6762 | we need to set *jump_target. */ | |
6763 | else | |
6764 | { | |
6765 | hash_set<tree> pset; | |
6766 | check_for_return_continue_data data = { &pset, NULL_TREE }; | |
6767 | if (tree ret_expr | |
6768 | = cp_walk_tree (&SWITCH_STMT_BODY (t), check_for_return_continue, | |
6769 | &data, &pset)) | |
6770 | /* The switch might return. */ | |
6771 | *jump_target = ret_expr; | |
6772 | else if (data.continue_stmt) | |
6773 | /* The switch can't return, but might continue. */ | |
6774 | *jump_target = data.continue_stmt; | |
6775 | } | |
60813a46 JM |
6776 | return true; |
6777 | ||
58611fb6 | 6778 | case STMT_EXPR: |
69eb4fde | 6779 | return RECUR (STMT_EXPR_STMT (t), rval); |
58611fb6 | 6780 | |
2d76680f | 6781 | case LAMBDA_EXPR: |
899ac3b8 JM |
6782 | if (cxx_dialect >= cxx17) |
6783 | /* In C++17 lambdas can be constexpr, don't give up yet. */ | |
6784 | return true; | |
6785 | else if (flags & tf_error) | |
6786 | error_at (loc, "lambda-expression is not a constant expression " | |
6787 | "before C++17"); | |
6788 | return false; | |
6789 | ||
2d76680f PC |
6790 | case DYNAMIC_CAST_EXPR: |
6791 | case PSEUDO_DTOR_EXPR: | |
2d76680f PC |
6792 | case NEW_EXPR: |
6793 | case VEC_NEW_EXPR: | |
6794 | case DELETE_EXPR: | |
6795 | case VEC_DELETE_EXPR: | |
6796 | case THROW_EXPR: | |
e40b6fc7 JJ |
6797 | case OMP_PARALLEL: |
6798 | case OMP_TASK: | |
6799 | case OMP_FOR: | |
897064e2 | 6800 | case OMP_SIMD: |
e40b6fc7 JJ |
6801 | case OMP_DISTRIBUTE: |
6802 | case OMP_TASKLOOP: | |
d81ab49d | 6803 | case OMP_LOOP: |
e40b6fc7 JJ |
6804 | case OMP_TEAMS: |
6805 | case OMP_TARGET_DATA: | |
6806 | case OMP_TARGET: | |
6807 | case OMP_SECTIONS: | |
6808 | case OMP_ORDERED: | |
6809 | case OMP_CRITICAL: | |
6810 | case OMP_SINGLE: | |
6811 | case OMP_SECTION: | |
6812 | case OMP_MASTER: | |
6813 | case OMP_TASKGROUP: | |
6814 | case OMP_TARGET_UPDATE: | |
6815 | case OMP_TARGET_ENTER_DATA: | |
6816 | case OMP_TARGET_EXIT_DATA: | |
2d76680f PC |
6817 | case OMP_ATOMIC: |
6818 | case OMP_ATOMIC_READ: | |
6819 | case OMP_ATOMIC_CAPTURE_OLD: | |
6820 | case OMP_ATOMIC_CAPTURE_NEW: | |
28567c40 | 6821 | case OMP_DEPOBJ: |
e40b6fc7 JJ |
6822 | case OACC_PARALLEL: |
6823 | case OACC_KERNELS: | |
6824 | case OACC_DATA: | |
6825 | case OACC_HOST_DATA: | |
6826 | case OACC_LOOP: | |
6827 | case OACC_CACHE: | |
6828 | case OACC_DECLARE: | |
6829 | case OACC_ENTER_DATA: | |
6830 | case OACC_EXIT_DATA: | |
6831 | case OACC_UPDATE: | |
2d76680f PC |
6832 | /* GCC internal stuff. */ |
6833 | case VA_ARG_EXPR: | |
2d76680f | 6834 | case TRANSACTION_EXPR: |
81b6a6c5 | 6835 | case AT_ENCODE_EXPR: |
60813a46 | 6836 | fail: |
2d76680f | 6837 | if (flags & tf_error) |
e40b6fc7 | 6838 | error_at (loc, "expression %qE is not a constant expression", t); |
2d76680f PC |
6839 | return false; |
6840 | ||
529bc410 | 6841 | case ASM_EXPR: |
7c814975 MP |
6842 | if (flags & tf_error) |
6843 | inline_asm_in_constexpr_error (loc); | |
6844 | return false; | |
529bc410 | 6845 | |
bf8d8309 MP |
6846 | case OBJ_TYPE_REF: |
6847 | if (cxx_dialect >= cxx2a) | |
6848 | /* In C++2a virtual calls can be constexpr, don't give up yet. */ | |
6849 | return true; | |
6850 | else if (flags & tf_error) | |
a9c697b8 MS |
6851 | error_at (loc, |
6852 | "virtual functions cannot be %<constexpr%> before C++2a"); | |
bf8d8309 MP |
6853 | return false; |
6854 | ||
2d76680f PC |
6855 | case TYPEID_EXPR: |
6856 | /* -- a typeid expression whose operand is of polymorphic | |
6857 | class type; */ | |
6858 | { | |
6859 | tree e = TREE_OPERAND (t, 0); | |
6860 | if (!TYPE_P (e) && !type_dependent_expression_p (e) | |
6861 | && TYPE_POLYMORPHIC_P (TREE_TYPE (e))) | |
6862 | { | |
6863 | if (flags & tf_error) | |
a9c697b8 | 6864 | error_at (loc, "%<typeid%> is not a constant expression " |
e40b6fc7 | 6865 | "because %qE is of polymorphic type", e); |
2d76680f PC |
6866 | return false; |
6867 | } | |
6868 | return true; | |
6869 | } | |
6870 | ||
1af4ebf5 | 6871 | case POINTER_DIFF_EXPR: |
2d76680f | 6872 | case MINUS_EXPR: |
2d76680f PC |
6873 | want_rval = true; |
6874 | goto binary; | |
6875 | ||
6876 | case LT_EXPR: | |
6877 | case LE_EXPR: | |
6878 | case GT_EXPR: | |
6879 | case GE_EXPR: | |
6880 | case EQ_EXPR: | |
6881 | case NE_EXPR: | |
2d76680f PC |
6882 | want_rval = true; |
6883 | goto binary; | |
6884 | ||
60813a46 JM |
6885 | case PREINCREMENT_EXPR: |
6886 | case POSTINCREMENT_EXPR: | |
6887 | case PREDECREMENT_EXPR: | |
6888 | case POSTDECREMENT_EXPR: | |
6889 | if (cxx_dialect < cxx14) | |
6890 | goto fail; | |
6891 | goto unary; | |
6892 | ||
2d76680f PC |
6893 | case BIT_NOT_EXPR: |
6894 | /* A destructor. */ | |
6895 | if (TYPE_P (TREE_OPERAND (t, 0))) | |
6896 | return true; | |
191816a3 | 6897 | /* fall through. */ |
2d76680f | 6898 | |
2d76680f PC |
6899 | case CONJ_EXPR: |
6900 | case SAVE_EXPR: | |
6901 | case FIX_TRUNC_EXPR: | |
6902 | case FLOAT_EXPR: | |
6903 | case NEGATE_EXPR: | |
6904 | case ABS_EXPR: | |
e197e64e | 6905 | case ABSU_EXPR: |
2d76680f PC |
6906 | case TRUTH_NOT_EXPR: |
6907 | case FIXED_CONVERT_EXPR: | |
6908 | case UNARY_PLUS_EXPR: | |
4856a1f0 PC |
6909 | case UNARY_LEFT_FOLD_EXPR: |
6910 | case UNARY_RIGHT_FOLD_EXPR: | |
60813a46 | 6911 | unary: |
69eb4fde | 6912 | return RECUR (TREE_OPERAND (t, 0), rval); |
2d76680f PC |
6913 | |
6914 | case CAST_EXPR: | |
6915 | case CONST_CAST_EXPR: | |
6916 | case STATIC_CAST_EXPR: | |
6917 | case REINTERPRET_CAST_EXPR: | |
6918 | case IMPLICIT_CONV_EXPR: | |
6919 | if (cxx_dialect < cxx11 | |
6920 | && !dependent_type_p (TREE_TYPE (t)) | |
6921 | && !INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))) | |
6922 | /* In C++98, a conversion to non-integral type can't be part of a | |
6923 | constant expression. */ | |
6924 | { | |
6925 | if (flags & tf_error) | |
e40b6fc7 JJ |
6926 | error_at (loc, |
6927 | "cast to non-integral type %qT in a constant expression", | |
6928 | TREE_TYPE (t)); | |
2d76680f PC |
6929 | return false; |
6930 | } | |
fe0604d3 MP |
6931 | /* This might be a conversion from a class to a (potentially) literal |
6932 | type. Let's consider it potentially constant since the conversion | |
6933 | might be a constexpr user-defined conversion. */ | |
6934 | else if (cxx_dialect >= cxx11 | |
6935 | && (dependent_type_p (TREE_TYPE (t)) | |
6936 | || !COMPLETE_TYPE_P (TREE_TYPE (t)) | |
6937 | || literal_type_p (TREE_TYPE (t))) | |
6938 | && TREE_OPERAND (t, 0)) | |
6939 | { | |
6940 | tree type = TREE_TYPE (TREE_OPERAND (t, 0)); | |
6941 | /* If this is a dependent type, it could end up being a class | |
6942 | with conversions. */ | |
6943 | if (type == NULL_TREE || WILDCARD_TYPE_P (type)) | |
6944 | return true; | |
6945 | /* Or a non-dependent class which has conversions. */ | |
6946 | else if (CLASS_TYPE_P (type) | |
6947 | && (TYPE_HAS_CONVERSION (type) || dependent_scope_p (type))) | |
6948 | return true; | |
6949 | } | |
2d76680f | 6950 | |
69eb4fde | 6951 | return (RECUR (TREE_OPERAND (t, 0), |
9f613f06 | 6952 | !TYPE_REF_P (TREE_TYPE (t)))); |
2d76680f | 6953 | |
60813a46 | 6954 | case BIND_EXPR: |
69eb4fde | 6955 | return RECUR (BIND_EXPR_BODY (t), want_rval); |
60813a46 | 6956 | |
60813a46 JM |
6957 | case CLEANUP_POINT_EXPR: |
6958 | case MUST_NOT_THROW_EXPR: | |
6959 | case TRY_CATCH_EXPR: | |
769430b2 | 6960 | case TRY_BLOCK: |
60813a46 JM |
6961 | case EH_SPEC_BLOCK: |
6962 | case EXPR_STMT: | |
2d76680f PC |
6963 | case PAREN_EXPR: |
6964 | case NON_DEPENDENT_EXPR: | |
6965 | /* For convenience. */ | |
f937929e JM |
6966 | case LOOP_EXPR: |
6967 | case EXIT_EXPR: | |
69eb4fde | 6968 | return RECUR (TREE_OPERAND (t, 0), want_rval); |
2d76680f | 6969 | |
98e5a19a JM |
6970 | case DECL_EXPR: |
6971 | tmp = DECL_EXPR_DECL (t); | |
6972 | if (VAR_P (tmp) && !DECL_ARTIFICIAL (tmp)) | |
6973 | { | |
6974 | if (TREE_STATIC (tmp)) | |
6975 | { | |
6976 | if (flags & tf_error) | |
6977 | error_at (DECL_SOURCE_LOCATION (tmp), "%qD declared " | |
4b691b13 | 6978 | "%<static%> in %<constexpr%> context", tmp); |
98e5a19a JM |
6979 | return false; |
6980 | } | |
6981 | else if (CP_DECL_THREAD_LOCAL_P (tmp)) | |
6982 | { | |
6983 | if (flags & tf_error) | |
6984 | error_at (DECL_SOURCE_LOCATION (tmp), "%qD declared " | |
4b691b13 | 6985 | "%<thread_local%> in %<constexpr%> context", tmp); |
98e5a19a JM |
6986 | return false; |
6987 | } | |
3885527d PC |
6988 | else if (!check_for_uninitialized_const_var |
6989 | (tmp, /*constexpr_context_p=*/true, flags)) | |
6990 | return false; | |
98e5a19a JM |
6991 | } |
6992 | return RECUR (tmp, want_rval); | |
6993 | ||
769430b2 JM |
6994 | case TRY_FINALLY_EXPR: |
6995 | return (RECUR (TREE_OPERAND (t, 0), want_rval) | |
6996 | && RECUR (TREE_OPERAND (t, 1), any)); | |
6997 | ||
2d76680f | 6998 | case SCOPE_REF: |
69eb4fde | 6999 | return RECUR (TREE_OPERAND (t, 1), want_rval); |
2d76680f PC |
7000 | |
7001 | case TARGET_EXPR: | |
d3a9902e JM |
7002 | if (!TARGET_EXPR_DIRECT_INIT_P (t) |
7003 | && !literal_type_p (TREE_TYPE (t))) | |
2d76680f PC |
7004 | { |
7005 | if (flags & tf_error) | |
7006 | { | |
097f82ec | 7007 | auto_diagnostic_group d; |
e40b6fc7 JJ |
7008 | error_at (loc, "temporary of non-literal type %qT in a " |
7009 | "constant expression", TREE_TYPE (t)); | |
2d76680f PC |
7010 | explain_non_literal_class (TREE_TYPE (t)); |
7011 | } | |
7012 | return false; | |
7013 | } | |
191816a3 | 7014 | /* FALLTHRU */ |
2d76680f | 7015 | case INIT_EXPR: |
69eb4fde | 7016 | return RECUR (TREE_OPERAND (t, 1), rval); |
2d76680f PC |
7017 | |
7018 | case CONSTRUCTOR: | |
7019 | { | |
7020 | vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (t); | |
7021 | constructor_elt *ce; | |
7022 | for (i = 0; vec_safe_iterate (v, i, &ce); ++i) | |
69eb4fde | 7023 | if (!RECUR (ce->value, want_rval)) |
2d76680f PC |
7024 | return false; |
7025 | return true; | |
7026 | } | |
7027 | ||
7028 | case TREE_LIST: | |
7029 | { | |
7030 | gcc_assert (TREE_PURPOSE (t) == NULL_TREE | |
7031 | || DECL_P (TREE_PURPOSE (t))); | |
69eb4fde | 7032 | if (!RECUR (TREE_VALUE (t), want_rval)) |
2d76680f PC |
7033 | return false; |
7034 | if (TREE_CHAIN (t) == NULL_TREE) | |
7035 | return true; | |
69eb4fde | 7036 | return RECUR (TREE_CHAIN (t), want_rval); |
2d76680f PC |
7037 | } |
7038 | ||
7039 | case TRUNC_DIV_EXPR: | |
7040 | case CEIL_DIV_EXPR: | |
7041 | case FLOOR_DIV_EXPR: | |
7042 | case ROUND_DIV_EXPR: | |
7043 | case TRUNC_MOD_EXPR: | |
7044 | case CEIL_MOD_EXPR: | |
7045 | case ROUND_MOD_EXPR: | |
7046 | { | |
7047 | tree denom = TREE_OPERAND (t, 1); | |
69eb4fde | 7048 | if (!RECUR (denom, rval)) |
2d76680f PC |
7049 | return false; |
7050 | /* We can't call cxx_eval_outermost_constant_expr on an expression | |
234bef96 | 7051 | that hasn't been through instantiate_non_dependent_expr yet. */ |
2d76680f PC |
7052 | if (!processing_template_decl) |
7053 | denom = cxx_eval_outermost_constant_expr (denom, true); | |
7054 | if (integer_zerop (denom)) | |
7055 | { | |
7056 | if (flags & tf_error) | |
64d6d399 | 7057 | error ("division by zero is not a constant expression"); |
2d76680f PC |
7058 | return false; |
7059 | } | |
7060 | else | |
7061 | { | |
7062 | want_rval = true; | |
69eb4fde | 7063 | return RECUR (TREE_OPERAND (t, 0), want_rval); |
2d76680f PC |
7064 | } |
7065 | } | |
7066 | ||
7067 | case COMPOUND_EXPR: | |
7068 | { | |
7069 | /* check_return_expr sometimes wraps a TARGET_EXPR in a | |
7070 | COMPOUND_EXPR; don't get confused. Also handle EMPTY_CLASS_EXPR | |
7071 | introduced by build_call_a. */ | |
7072 | tree op0 = TREE_OPERAND (t, 0); | |
7073 | tree op1 = TREE_OPERAND (t, 1); | |
7074 | STRIP_NOPS (op1); | |
7075 | if ((TREE_CODE (op0) == TARGET_EXPR && op1 == TARGET_EXPR_SLOT (op0)) | |
7076 | || TREE_CODE (op1) == EMPTY_CLASS_EXPR) | |
69eb4fde | 7077 | return RECUR (op0, want_rval); |
2d76680f PC |
7078 | else |
7079 | goto binary; | |
7080 | } | |
7081 | ||
7082 | /* If the first operand is the non-short-circuit constant, look at | |
7083 | the second operand; otherwise we only care about the first one for | |
7084 | potentiality. */ | |
7085 | case TRUTH_AND_EXPR: | |
7086 | case TRUTH_ANDIF_EXPR: | |
7087 | tmp = boolean_true_node; | |
7088 | goto truth; | |
7089 | case TRUTH_OR_EXPR: | |
7090 | case TRUTH_ORIF_EXPR: | |
7091 | tmp = boolean_false_node; | |
7092 | truth: | |
7093 | { | |
7094 | tree op = TREE_OPERAND (t, 0); | |
69eb4fde | 7095 | if (!RECUR (op, rval)) |
2d76680f PC |
7096 | return false; |
7097 | if (!processing_template_decl) | |
7098 | op = cxx_eval_outermost_constant_expr (op, true); | |
7099 | if (tree_int_cst_equal (op, tmp)) | |
69eb4fde | 7100 | return RECUR (TREE_OPERAND (t, 1), rval); |
2d76680f PC |
7101 | else |
7102 | return true; | |
7103 | } | |
7104 | ||
7105 | case PLUS_EXPR: | |
7106 | case MULT_EXPR: | |
7107 | case POINTER_PLUS_EXPR: | |
7108 | case RDIV_EXPR: | |
7109 | case EXACT_DIV_EXPR: | |
7110 | case MIN_EXPR: | |
7111 | case MAX_EXPR: | |
7112 | case LSHIFT_EXPR: | |
7113 | case RSHIFT_EXPR: | |
2d76680f PC |
7114 | case BIT_IOR_EXPR: |
7115 | case BIT_XOR_EXPR: | |
7116 | case BIT_AND_EXPR: | |
7117 | case TRUTH_XOR_EXPR: | |
7118 | case UNORDERED_EXPR: | |
7119 | case ORDERED_EXPR: | |
7120 | case UNLT_EXPR: | |
7121 | case UNLE_EXPR: | |
7122 | case UNGT_EXPR: | |
7123 | case UNGE_EXPR: | |
7124 | case UNEQ_EXPR: | |
7125 | case LTGT_EXPR: | |
7126 | case RANGE_EXPR: | |
7127 | case COMPLEX_EXPR: | |
7128 | want_rval = true; | |
7129 | /* Fall through. */ | |
7130 | case ARRAY_REF: | |
7131 | case ARRAY_RANGE_REF: | |
7132 | case MEMBER_REF: | |
7133 | case DOTSTAR_EXPR: | |
41b38772 | 7134 | case MEM_REF: |
4856a1f0 PC |
7135 | case BINARY_LEFT_FOLD_EXPR: |
7136 | case BINARY_RIGHT_FOLD_EXPR: | |
2d76680f PC |
7137 | binary: |
7138 | for (i = 0; i < 2; ++i) | |
69eb4fde | 7139 | if (!RECUR (TREE_OPERAND (t, i), want_rval)) |
2d76680f PC |
7140 | return false; |
7141 | return true; | |
7142 | ||
2d76680f PC |
7143 | case VEC_PERM_EXPR: |
7144 | for (i = 0; i < 3; ++i) | |
69eb4fde | 7145 | if (!RECUR (TREE_OPERAND (t, i), true)) |
2d76680f PC |
7146 | return false; |
7147 | return true; | |
7148 | ||
7149 | case COND_EXPR: | |
8e007055 | 7150 | if (COND_EXPR_IS_VEC_DELETE (t) && cxx_dialect < cxx2a) |
d5bcd6d4 JM |
7151 | { |
7152 | if (flags & tf_error) | |
e40b6fc7 | 7153 | error_at (loc, "%<delete[]%> is not a constant expression"); |
d5bcd6d4 JM |
7154 | return false; |
7155 | } | |
7156 | /* Fall through. */ | |
7157 | case IF_STMT: | |
2d76680f PC |
7158 | case VEC_COND_EXPR: |
7159 | /* If the condition is a known constant, we know which of the legs we | |
7160 | care about; otherwise we only require that the condition and | |
7161 | either of the legs be potentially constant. */ | |
7162 | tmp = TREE_OPERAND (t, 0); | |
69eb4fde | 7163 | if (!RECUR (tmp, rval)) |
2d76680f PC |
7164 | return false; |
7165 | if (!processing_template_decl) | |
7166 | tmp = cxx_eval_outermost_constant_expr (tmp, true); | |
7167 | if (integer_zerop (tmp)) | |
69eb4fde | 7168 | return RECUR (TREE_OPERAND (t, 2), want_rval); |
2d76680f | 7169 | else if (TREE_CODE (tmp) == INTEGER_CST) |
69eb4fde | 7170 | return RECUR (TREE_OPERAND (t, 1), want_rval); |
2d76680f PC |
7171 | for (i = 1; i < 3; ++i) |
7172 | if (potential_constant_expression_1 (TREE_OPERAND (t, i), | |
3075affd JM |
7173 | want_rval, strict, now, |
7174 | tf_none, jump_target)) | |
2d76680f PC |
7175 | return true; |
7176 | if (flags & tf_error) | |
e40b6fc7 | 7177 | error_at (loc, "expression %qE is not a constant expression", t); |
2d76680f PC |
7178 | return false; |
7179 | ||
7180 | case VEC_INIT_EXPR: | |
7181 | if (VEC_INIT_EXPR_IS_CONSTEXPR (t)) | |
7182 | return true; | |
7183 | if (flags & tf_error) | |
7184 | { | |
e40b6fc7 | 7185 | error_at (loc, "non-constant array initialization"); |
2d76680f PC |
7186 | diagnose_non_constexpr_vec_init (t); |
7187 | } | |
7188 | return false; | |
7189 | ||
133bc698 JM |
7190 | case TYPE_DECL: |
7191 | case TAG_DEFN: | |
7192 | /* We can see these in statement-expressions. */ | |
7193 | return true; | |
7194 | ||
baf9ebc8 | 7195 | case CLEANUP_STMT: |
1006c9d4 JJ |
7196 | if (!RECUR (CLEANUP_BODY (t), any)) |
7197 | return false; | |
7198 | if (!CLEANUP_EH_ONLY (t) && !RECUR (CLEANUP_EXPR (t), any)) | |
7199 | return false; | |
7200 | return true; | |
7201 | ||
cda0a029 | 7202 | case EMPTY_CLASS_EXPR: |
7fef86d3 | 7203 | case PREDICT_EXPR: |
cda0a029 JM |
7204 | return false; |
7205 | ||
f937929e JM |
7206 | case GOTO_EXPR: |
7207 | { | |
7208 | tree *target = &TREE_OPERAND (t, 0); | |
ab3af181 JJ |
7209 | /* Gotos representing break and continue are OK. */ |
7210 | if (breaks (target) || continues (target)) | |
3075affd JM |
7211 | { |
7212 | *jump_target = *target; | |
7213 | return true; | |
7214 | } | |
ab3af181 | 7215 | if (flags & tf_error) |
e40b6fc7 | 7216 | error_at (loc, "%<goto%> is not a constant expression"); |
ab3af181 | 7217 | return false; |
f937929e JM |
7218 | } |
7219 | ||
98e09245 | 7220 | case ANNOTATE_EXPR: |
98e09245 JJ |
7221 | return RECUR (TREE_OPERAND (t, 0), rval); |
7222 | ||
2d76680f PC |
7223 | default: |
7224 | if (objc_is_property_ref (t)) | |
7225 | return false; | |
7226 | ||
7227 | sorry ("unexpected AST of kind %s", get_tree_code_name (TREE_CODE (t))); | |
ab3af181 | 7228 | gcc_unreachable (); |
2d76680f PC |
7229 | return false; |
7230 | } | |
69eb4fde | 7231 | #undef RECUR |
2d76680f PC |
7232 | } |
7233 | ||
3075affd JM |
7234 | bool |
7235 | potential_constant_expression_1 (tree t, bool want_rval, bool strict, bool now, | |
7236 | tsubst_flags_t flags) | |
7237 | { | |
7238 | tree target = NULL_TREE; | |
7239 | return potential_constant_expression_1 (t, want_rval, strict, now, | |
7240 | flags, &target); | |
7241 | } | |
7242 | ||
2d76680f PC |
7243 | /* The main entry point to the above. */ |
7244 | ||
7245 | bool | |
7246 | potential_constant_expression (tree t) | |
7247 | { | |
a0ab7ccd | 7248 | return potential_constant_expression_1 (t, false, true, false, tf_none); |
2d76680f PC |
7249 | } |
7250 | ||
7251 | /* As above, but require a constant rvalue. */ | |
7252 | ||
7253 | bool | |
7254 | potential_rvalue_constant_expression (tree t) | |
7255 | { | |
a0ab7ccd | 7256 | return potential_constant_expression_1 (t, true, true, false, tf_none); |
2d76680f PC |
7257 | } |
7258 | ||
7259 | /* Like above, but complain about non-constant expressions. */ | |
7260 | ||
7261 | bool | |
7262 | require_potential_constant_expression (tree t) | |
7263 | { | |
d8cff23f MP |
7264 | return potential_constant_expression_1 (t, false, true, false, |
7265 | tf_warning_or_error); | |
2d76680f PC |
7266 | } |
7267 | ||
7268 | /* Cross product of the above. */ | |
7269 | ||
7270 | bool | |
7271 | require_potential_rvalue_constant_expression (tree t) | |
7272 | { | |
d8cff23f MP |
7273 | return potential_constant_expression_1 (t, true, true, false, |
7274 | tf_warning_or_error); | |
7275 | } | |
7276 | ||
7277 | /* Like above, but don't consider PARM_DECL a potential_constant_expression. */ | |
7278 | ||
7279 | bool | |
7280 | require_rvalue_constant_expression (tree t) | |
7281 | { | |
7282 | return potential_constant_expression_1 (t, true, true, true, | |
7283 | tf_warning_or_error); | |
a0ab7ccd JM |
7284 | } |
7285 | ||
7286 | /* Like potential_constant_expression, but don't consider possible constexpr | |
7287 | substitution of the current function. That is, PARM_DECL qualifies under | |
7288 | potential_constant_expression, but not here. | |
7289 | ||
7290 | This is basically what you can check when any actual constant values might | |
7291 | be value-dependent. */ | |
7292 | ||
7293 | bool | |
7294 | is_constant_expression (tree t) | |
7295 | { | |
7296 | return potential_constant_expression_1 (t, false, true, true, tf_none); | |
7297 | } | |
7298 | ||
7299 | /* Like above, but complain about non-constant expressions. */ | |
7300 | ||
7301 | bool | |
7302 | require_constant_expression (tree t) | |
7303 | { | |
7304 | return potential_constant_expression_1 (t, false, true, true, | |
7305 | tf_warning_or_error); | |
7306 | } | |
7307 | ||
7308 | /* Like is_constant_expression, but allow const variables that are not allowed | |
7309 | under constexpr rules. */ | |
7310 | ||
7311 | bool | |
7312 | is_static_init_expression (tree t) | |
7313 | { | |
7314 | return potential_constant_expression_1 (t, false, false, true, tf_none); | |
2d76680f PC |
7315 | } |
7316 | ||
eb07f187 JM |
7317 | /* Returns true if T is a potential constant expression that is not |
7318 | instantiation-dependent, and therefore a candidate for constant folding even | |
7319 | in a template. */ | |
7320 | ||
7321 | bool | |
a0ab7ccd | 7322 | is_nondependent_constant_expression (tree t) |
eb07f187 JM |
7323 | { |
7324 | return (!type_unknown_p (t) | |
7325 | && !BRACE_ENCLOSED_INITIALIZER_P (t) | |
a0ab7ccd | 7326 | && is_constant_expression (t) |
eb07f187 JM |
7327 | && !instantiation_dependent_expression_p (t)); |
7328 | } | |
7329 | ||
7330 | /* Returns true if T is a potential static initializer expression that is not | |
7331 | instantiation-dependent. */ | |
7332 | ||
7333 | bool | |
a0ab7ccd | 7334 | is_nondependent_static_init_expression (tree t) |
eb07f187 JM |
7335 | { |
7336 | return (!type_unknown_p (t) | |
7337 | && !BRACE_ENCLOSED_INITIALIZER_P (t) | |
a0ab7ccd | 7338 | && is_static_init_expression (t) |
eb07f187 JM |
7339 | && !instantiation_dependent_expression_p (t)); |
7340 | } | |
7341 | ||
97f3003f JM |
7342 | /* Finalize constexpr processing after parsing. */ |
7343 | ||
7344 | void | |
7345 | fini_constexpr (void) | |
7346 | { | |
7347 | /* The contexpr call and fundef copies tables are no longer needed. */ | |
7348 | constexpr_call_table = NULL; | |
7349 | fundef_copies_table = NULL; | |
7350 | } | |
7351 | ||
2d76680f | 7352 | #include "gt-cp-constexpr.h" |