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f9885b8a | 1 | /* Perform -*- C++ -*- constant expression evaluation, including calls to |
2 | constexpr functions. These routines are used both during actual parsing | |
09b42213 | 3 | and during the instantiation of template functions. |
4 | ||
fbd26352 | 5 | Copyright (C) 1998-2019 Free Software Foundation, Inc. |
09b42213 | 6 | |
7 | This file is part of GCC. | |
8 | ||
9 | GCC is free software; you can redistribute it and/or modify it | |
10 | under the terms of the GNU General Public License as published by | |
11 | the Free Software Foundation; either version 3, or (at your option) | |
12 | any later version. | |
13 | ||
14 | GCC is distributed in the hope that it will be useful, but | |
15 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
17 | General Public License for more details. | |
18 | ||
19 | You should have received a copy of the GNU General Public License | |
20 | along with GCC; see the file COPYING3. If not see | |
21 | <http://www.gnu.org/licenses/>. */ | |
22 | ||
23 | #include "config.h" | |
24 | #include "system.h" | |
25 | #include "coretypes.h" | |
09b42213 | 26 | #include "cp-tree.h" |
4cba6f60 | 27 | #include "varasm.h" |
09b42213 | 28 | #include "c-family/c-objc.h" |
29 | #include "tree-iterator.h" | |
30 | #include "gimplify.h" | |
31 | #include "builtins.h" | |
9c96033c | 32 | #include "tree-inline.h" |
6b71bdb4 | 33 | #include "ubsan.h" |
732905bb | 34 | #include "gimple-fold.h" |
c300fe28 | 35 | #include "timevar.h" |
59409f09 | 36 | #include "fold-const-call.h" |
09b42213 | 37 | |
38 | static bool verify_constant (tree, bool, bool *, bool *); | |
39 | #define VERIFY_CONSTANT(X) \ | |
40 | do { \ | |
f83e6885 | 41 | if (verify_constant ((X), ctx->quiet, non_constant_p, overflow_p)) \ |
09b42213 | 42 | return t; \ |
43 | } while (0) | |
44 | ||
9a97d94a | 45 | static HOST_WIDE_INT find_array_ctor_elt (tree ary, tree dindex, |
46 | bool insert = false); | |
47 | ||
09b42213 | 48 | /* Returns true iff FUN is an instantiation of a constexpr function |
49 | template or a defaulted constexpr function. */ | |
50 | ||
51 | bool | |
52 | is_instantiation_of_constexpr (tree fun) | |
53 | { | |
54 | return ((DECL_TEMPLOID_INSTANTIATION (fun) | |
55 | && DECL_DECLARED_CONSTEXPR_P (DECL_TI_TEMPLATE (fun))) | |
56 | || (DECL_DEFAULTED_FN (fun) | |
57 | && DECL_DECLARED_CONSTEXPR_P (fun))); | |
58 | } | |
59 | ||
60 | /* Return true if T is a literal type. */ | |
61 | ||
62 | bool | |
63 | literal_type_p (tree t) | |
64 | { | |
65 | if (SCALAR_TYPE_P (t) | |
76249021 | 66 | || VECTOR_TYPE_P (t) |
90ad495b | 67 | || TYPE_REF_P (t) |
dd418b39 | 68 | || (VOID_TYPE_P (t) && cxx_dialect >= cxx14)) |
09b42213 | 69 | return true; |
70 | if (CLASS_TYPE_P (t)) | |
71 | { | |
72 | t = complete_type (t); | |
73 | gcc_assert (COMPLETE_TYPE_P (t) || errorcount); | |
74 | return CLASSTYPE_LITERAL_P (t); | |
75 | } | |
76 | if (TREE_CODE (t) == ARRAY_TYPE) | |
77 | return literal_type_p (strip_array_types (t)); | |
78 | return false; | |
79 | } | |
80 | ||
81 | /* If DECL is a variable declared `constexpr', require its type | |
e89257db | 82 | be literal. Return error_mark_node if we give an error, the |
83 | DECL otherwise. */ | |
09b42213 | 84 | |
85 | tree | |
86 | ensure_literal_type_for_constexpr_object (tree decl) | |
87 | { | |
88 | tree type = TREE_TYPE (decl); | |
89 | if (VAR_P (decl) | |
90 | && (DECL_DECLARED_CONSTEXPR_P (decl) | |
91 | || var_in_constexpr_fn (decl)) | |
92 | && !processing_template_decl) | |
93 | { | |
94 | tree stype = strip_array_types (type); | |
95 | if (CLASS_TYPE_P (stype) && !COMPLETE_TYPE_P (complete_type (stype))) | |
96 | /* Don't complain here, we'll complain about incompleteness | |
97 | when we try to initialize the variable. */; | |
03dbe51b | 98 | else if (type_uses_auto (type)) |
99 | /* We don't know the actual type yet. */; | |
09b42213 | 100 | else if (!literal_type_p (type)) |
101 | { | |
102 | if (DECL_DECLARED_CONSTEXPR_P (decl)) | |
e45408ff | 103 | { |
bc35ef65 | 104 | auto_diagnostic_group d; |
04e6d9db | 105 | error_at (DECL_SOURCE_LOCATION (decl), |
106 | "the type %qT of %<constexpr%> variable %qD " | |
107 | "is not literal", type, decl); | |
e45408ff | 108 | explain_non_literal_class (type); |
e89257db | 109 | decl = error_mark_node; |
e45408ff | 110 | } |
09b42213 | 111 | else |
9c96033c | 112 | { |
b7e4a558 | 113 | if (!is_instantiation_of_constexpr (current_function_decl)) |
e45408ff | 114 | { |
bc35ef65 | 115 | auto_diagnostic_group d; |
04e6d9db | 116 | error_at (DECL_SOURCE_LOCATION (decl), |
117 | "variable %qD of non-literal type %qT in " | |
118 | "%<constexpr%> function", decl, type); | |
e45408ff | 119 | explain_non_literal_class (type); |
e89257db | 120 | decl = error_mark_node; |
e45408ff | 121 | } |
9c96033c | 122 | cp_function_chain->invalid_constexpr = true; |
123 | } | |
09b42213 | 124 | } |
fdafeeb7 | 125 | else if (DECL_DECLARED_CONSTEXPR_P (decl) |
126 | && variably_modified_type_p (type, NULL_TREE)) | |
127 | { | |
04e6d9db | 128 | error_at (DECL_SOURCE_LOCATION (decl), |
129 | "%<constexpr%> variable %qD has variably-modified " | |
130 | "type %qT", decl, type); | |
fdafeeb7 | 131 | decl = error_mark_node; |
132 | } | |
09b42213 | 133 | } |
134 | return decl; | |
135 | } | |
136 | ||
137 | /* Representation of entries in the constexpr function definition table. */ | |
138 | ||
139 | struct GTY((for_user)) constexpr_fundef { | |
140 | tree decl; | |
141 | tree body; | |
02d7a132 | 142 | tree parms; |
143 | tree result; | |
09b42213 | 144 | }; |
145 | ||
b594087e | 146 | struct constexpr_fundef_hasher : ggc_ptr_hash<constexpr_fundef> |
09b42213 | 147 | { |
148 | static hashval_t hash (constexpr_fundef *); | |
149 | static bool equal (constexpr_fundef *, constexpr_fundef *); | |
150 | }; | |
151 | ||
152 | /* This table holds all constexpr function definitions seen in | |
153 | the current translation unit. */ | |
154 | ||
155 | static GTY (()) hash_table<constexpr_fundef_hasher> *constexpr_fundef_table; | |
156 | ||
157 | /* Utility function used for managing the constexpr function table. | |
158 | Return true if the entries pointed to by P and Q are for the | |
159 | same constexpr function. */ | |
160 | ||
161 | inline bool | |
162 | constexpr_fundef_hasher::equal (constexpr_fundef *lhs, constexpr_fundef *rhs) | |
163 | { | |
164 | return lhs->decl == rhs->decl; | |
165 | } | |
166 | ||
167 | /* Utility function used for managing the constexpr function table. | |
168 | Return a hash value for the entry pointed to by Q. */ | |
169 | ||
170 | inline hashval_t | |
171 | constexpr_fundef_hasher::hash (constexpr_fundef *fundef) | |
172 | { | |
173 | return DECL_UID (fundef->decl); | |
174 | } | |
175 | ||
176 | /* Return a previously saved definition of function FUN. */ | |
177 | ||
178 | static constexpr_fundef * | |
179 | retrieve_constexpr_fundef (tree fun) | |
180 | { | |
09b42213 | 181 | if (constexpr_fundef_table == NULL) |
182 | return NULL; | |
183 | ||
02d7a132 | 184 | constexpr_fundef fundef = { fun, NULL, NULL, NULL }; |
09b42213 | 185 | return constexpr_fundef_table->find (&fundef); |
186 | } | |
187 | ||
188 | /* Check whether the parameter and return types of FUN are valid for a | |
189 | constexpr function, and complain if COMPLAIN. */ | |
190 | ||
33603066 | 191 | bool |
09b42213 | 192 | is_valid_constexpr_fn (tree fun, bool complain) |
193 | { | |
194 | bool ret = true; | |
195 | ||
7896267d | 196 | if (DECL_INHERITED_CTOR (fun) |
09b42213 | 197 | && TREE_CODE (fun) == TEMPLATE_DECL) |
198 | { | |
199 | ret = false; | |
200 | if (complain) | |
5967b28b | 201 | error ("inherited constructor %qD is not %<constexpr%>", |
7896267d | 202 | DECL_INHERITED_CTOR (fun)); |
09b42213 | 203 | } |
204 | else | |
205 | { | |
206 | for (tree parm = FUNCTION_FIRST_USER_PARM (fun); | |
207 | parm != NULL_TREE; parm = TREE_CHAIN (parm)) | |
208 | if (!literal_type_p (TREE_TYPE (parm))) | |
209 | { | |
210 | ret = false; | |
211 | if (complain) | |
212 | { | |
bc35ef65 | 213 | auto_diagnostic_group d; |
5967b28b | 214 | error ("invalid type for parameter %d of %<constexpr%> " |
09b42213 | 215 | "function %q+#D", DECL_PARM_INDEX (parm), fun); |
216 | explain_non_literal_class (TREE_TYPE (parm)); | |
217 | } | |
218 | } | |
219 | } | |
220 | ||
672871ce | 221 | if (LAMBDA_TYPE_P (CP_DECL_CONTEXT (fun)) && cxx_dialect < cxx17) |
222 | { | |
223 | ret = false; | |
224 | if (complain) | |
225 | inform (DECL_SOURCE_LOCATION (fun), | |
5967b28b | 226 | "lambdas are implicitly %<constexpr%> only in C++17 and later"); |
672871ce | 227 | } |
228 | else if (!DECL_CONSTRUCTOR_P (fun)) | |
09b42213 | 229 | { |
230 | tree rettype = TREE_TYPE (TREE_TYPE (fun)); | |
231 | if (!literal_type_p (rettype)) | |
232 | { | |
233 | ret = false; | |
234 | if (complain) | |
235 | { | |
bc35ef65 | 236 | auto_diagnostic_group d; |
5967b28b | 237 | error ("invalid return type %qT of %<constexpr%> function %q+D", |
09b42213 | 238 | rettype, fun); |
239 | explain_non_literal_class (rettype); | |
240 | } | |
241 | } | |
242 | ||
d66f34cf | 243 | /* C++14 DR 1684 removed this restriction. */ |
244 | if (cxx_dialect < cxx14 | |
245 | && DECL_NONSTATIC_MEMBER_FUNCTION_P (fun) | |
09b42213 | 246 | && !CLASSTYPE_LITERAL_P (DECL_CONTEXT (fun))) |
247 | { | |
248 | ret = false; | |
bc35ef65 | 249 | if (complain) |
250 | { | |
251 | auto_diagnostic_group d; | |
252 | if (pedwarn (DECL_SOURCE_LOCATION (fun), OPT_Wpedantic, | |
253 | "enclosing class of %<constexpr%> non-static" | |
254 | " member function %q+#D is not a literal type", | |
255 | fun)) | |
256 | explain_non_literal_class (DECL_CONTEXT (fun)); | |
257 | } | |
09b42213 | 258 | } |
259 | } | |
260 | else if (CLASSTYPE_VBASECLASSES (DECL_CONTEXT (fun))) | |
261 | { | |
262 | ret = false; | |
263 | if (complain) | |
264 | error ("%q#T has virtual base classes", DECL_CONTEXT (fun)); | |
265 | } | |
266 | ||
267 | return ret; | |
268 | } | |
269 | ||
270 | /* Subroutine of build_data_member_initialization. MEMBER is a COMPONENT_REF | |
271 | for a member of an anonymous aggregate, INIT is the initializer for that | |
272 | member, and VEC_OUTER is the vector of constructor elements for the class | |
273 | whose constructor we are processing. Add the initializer to the vector | |
274 | and return true to indicate success. */ | |
275 | ||
276 | static bool | |
277 | build_anon_member_initialization (tree member, tree init, | |
278 | vec<constructor_elt, va_gc> **vec_outer) | |
279 | { | |
280 | /* MEMBER presents the relevant fields from the inside out, but we need | |
281 | to build up the initializer from the outside in so that we can reuse | |
282 | previously built CONSTRUCTORs if this is, say, the second field in an | |
283 | anonymous struct. So we use a vec as a stack. */ | |
284 | auto_vec<tree, 2> fields; | |
285 | do | |
286 | { | |
287 | fields.safe_push (TREE_OPERAND (member, 1)); | |
288 | member = TREE_OPERAND (member, 0); | |
289 | } | |
290 | while (ANON_AGGR_TYPE_P (TREE_TYPE (member)) | |
291 | && TREE_CODE (member) == COMPONENT_REF); | |
292 | ||
293 | /* VEC has the constructor elements vector for the context of FIELD. | |
294 | If FIELD is an anonymous aggregate, we will push inside it. */ | |
295 | vec<constructor_elt, va_gc> **vec = vec_outer; | |
296 | tree field; | |
297 | while (field = fields.pop(), | |
298 | ANON_AGGR_TYPE_P (TREE_TYPE (field))) | |
299 | { | |
300 | tree ctor; | |
301 | /* If there is already an outer constructor entry for the anonymous | |
302 | aggregate FIELD, use it; otherwise, insert one. */ | |
303 | if (vec_safe_is_empty (*vec) | |
304 | || (*vec)->last().index != field) | |
305 | { | |
306 | ctor = build_constructor (TREE_TYPE (field), NULL); | |
307 | CONSTRUCTOR_APPEND_ELT (*vec, field, ctor); | |
308 | } | |
309 | else | |
310 | ctor = (*vec)->last().value; | |
311 | vec = &CONSTRUCTOR_ELTS (ctor); | |
312 | } | |
313 | ||
314 | /* Now we're at the innermost field, the one that isn't an anonymous | |
315 | aggregate. Add its initializer to the CONSTRUCTOR and we're done. */ | |
316 | gcc_assert (fields.is_empty()); | |
317 | CONSTRUCTOR_APPEND_ELT (*vec, field, init); | |
318 | ||
319 | return true; | |
320 | } | |
321 | ||
322 | /* Subroutine of build_constexpr_constructor_member_initializers. | |
323 | The expression tree T represents a data member initialization | |
324 | in a (constexpr) constructor definition. Build a pairing of | |
325 | the data member with its initializer, and prepend that pair | |
326 | to the existing initialization pair INITS. */ | |
327 | ||
328 | static bool | |
329 | build_data_member_initialization (tree t, vec<constructor_elt, va_gc> **vec) | |
330 | { | |
331 | tree member, init; | |
332 | if (TREE_CODE (t) == CLEANUP_POINT_EXPR) | |
333 | t = TREE_OPERAND (t, 0); | |
334 | if (TREE_CODE (t) == EXPR_STMT) | |
335 | t = TREE_OPERAND (t, 0); | |
336 | if (t == error_mark_node) | |
337 | return false; | |
338 | if (TREE_CODE (t) == STATEMENT_LIST) | |
339 | { | |
340 | tree_stmt_iterator i; | |
341 | for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i)) | |
342 | { | |
343 | if (! build_data_member_initialization (tsi_stmt (i), vec)) | |
344 | return false; | |
345 | } | |
346 | return true; | |
347 | } | |
348 | if (TREE_CODE (t) == CLEANUP_STMT) | |
349 | { | |
350 | /* We can't see a CLEANUP_STMT in a constructor for a literal class, | |
351 | but we can in a constexpr constructor for a non-literal class. Just | |
352 | ignore it; either all the initialization will be constant, in which | |
353 | case the cleanup can't run, or it can't be constexpr. | |
354 | Still recurse into CLEANUP_BODY. */ | |
355 | return build_data_member_initialization (CLEANUP_BODY (t), vec); | |
356 | } | |
357 | if (TREE_CODE (t) == CONVERT_EXPR) | |
358 | t = TREE_OPERAND (t, 0); | |
359 | if (TREE_CODE (t) == INIT_EXPR | |
9c96033c | 360 | /* vptr initialization shows up as a MODIFY_EXPR. In C++14 we only |
361 | use what this function builds for cx_check_missing_mem_inits, and | |
362 | assignment in the ctor body doesn't count. */ | |
363 | || (cxx_dialect < cxx14 && TREE_CODE (t) == MODIFY_EXPR)) | |
09b42213 | 364 | { |
365 | member = TREE_OPERAND (t, 0); | |
366 | init = break_out_target_exprs (TREE_OPERAND (t, 1)); | |
367 | } | |
368 | else if (TREE_CODE (t) == CALL_EXPR) | |
369 | { | |
9c96033c | 370 | tree fn = get_callee_fndecl (t); |
371 | if (!fn || !DECL_CONSTRUCTOR_P (fn)) | |
372 | /* We're only interested in calls to subobject constructors. */ | |
373 | return true; | |
09b42213 | 374 | member = CALL_EXPR_ARG (t, 0); |
375 | /* We don't use build_cplus_new here because it complains about | |
376 | abstract bases. Leaving the call unwrapped means that it has the | |
377 | wrong type, but cxx_eval_constant_expression doesn't care. */ | |
378 | init = break_out_target_exprs (t); | |
379 | } | |
380 | else if (TREE_CODE (t) == BIND_EXPR) | |
381 | return build_data_member_initialization (BIND_EXPR_BODY (t), vec); | |
09b42213 | 382 | else |
9c96033c | 383 | /* Don't add anything else to the CONSTRUCTOR. */ |
384 | return true; | |
09b42213 | 385 | if (INDIRECT_REF_P (member)) |
386 | member = TREE_OPERAND (member, 0); | |
387 | if (TREE_CODE (member) == NOP_EXPR) | |
388 | { | |
389 | tree op = member; | |
390 | STRIP_NOPS (op); | |
391 | if (TREE_CODE (op) == ADDR_EXPR) | |
392 | { | |
393 | gcc_assert (same_type_ignoring_top_level_qualifiers_p | |
394 | (TREE_TYPE (TREE_TYPE (op)), | |
395 | TREE_TYPE (TREE_TYPE (member)))); | |
396 | /* Initializing a cv-qualified member; we need to look through | |
397 | the const_cast. */ | |
398 | member = op; | |
399 | } | |
400 | else if (op == current_class_ptr | |
401 | && (same_type_ignoring_top_level_qualifiers_p | |
402 | (TREE_TYPE (TREE_TYPE (member)), | |
403 | current_class_type))) | |
404 | /* Delegating constructor. */ | |
405 | member = op; | |
406 | else | |
407 | { | |
408 | /* This is an initializer for an empty base; keep it for now so | |
409 | we can check it in cxx_eval_bare_aggregate. */ | |
410 | gcc_assert (is_empty_class (TREE_TYPE (TREE_TYPE (member)))); | |
411 | } | |
412 | } | |
413 | if (TREE_CODE (member) == ADDR_EXPR) | |
414 | member = TREE_OPERAND (member, 0); | |
415 | if (TREE_CODE (member) == COMPONENT_REF) | |
416 | { | |
417 | tree aggr = TREE_OPERAND (member, 0); | |
4952bc85 | 418 | if (TREE_CODE (aggr) == VAR_DECL) |
419 | /* Initializing a local variable, don't add anything. */ | |
420 | return true; | |
09b42213 | 421 | if (TREE_CODE (aggr) != COMPONENT_REF) |
422 | /* Normal member initialization. */ | |
423 | member = TREE_OPERAND (member, 1); | |
424 | else if (ANON_AGGR_TYPE_P (TREE_TYPE (aggr))) | |
425 | /* Initializing a member of an anonymous union. */ | |
426 | return build_anon_member_initialization (member, init, vec); | |
427 | else | |
428 | /* We're initializing a vtable pointer in a base. Leave it as | |
429 | COMPONENT_REF so we remember the path to get to the vfield. */ | |
430 | gcc_assert (TREE_TYPE (member) == vtbl_ptr_type_node); | |
431 | } | |
432 | ||
c678e23e | 433 | /* Value-initialization can produce multiple initializers for the |
434 | same field; use the last one. */ | |
435 | if (!vec_safe_is_empty (*vec) && (*vec)->last().index == member) | |
436 | (*vec)->last().value = init; | |
437 | else | |
438 | CONSTRUCTOR_APPEND_ELT (*vec, member, init); | |
09b42213 | 439 | return true; |
440 | } | |
441 | ||
442 | /* Subroutine of check_constexpr_ctor_body_1 and constexpr_fn_retval. | |
443 | In C++11 mode checks that the TYPE_DECLs in the BIND_EXPR_VARS of a | |
444 | BIND_EXPR conform to 7.1.5/3/4 on typedef and alias declarations. */ | |
445 | ||
446 | static bool | |
447 | check_constexpr_bind_expr_vars (tree t) | |
448 | { | |
449 | gcc_assert (TREE_CODE (t) == BIND_EXPR); | |
450 | ||
09b42213 | 451 | for (tree var = BIND_EXPR_VARS (t); var; var = DECL_CHAIN (var)) |
452 | if (TREE_CODE (var) == TYPE_DECL | |
04103c39 | 453 | && DECL_IMPLICIT_TYPEDEF_P (var) |
454 | && !LAMBDA_TYPE_P (TREE_TYPE (var))) | |
09b42213 | 455 | return false; |
456 | return true; | |
457 | } | |
458 | ||
459 | /* Subroutine of check_constexpr_ctor_body. */ | |
460 | ||
461 | static bool | |
462 | check_constexpr_ctor_body_1 (tree last, tree list) | |
463 | { | |
464 | switch (TREE_CODE (list)) | |
465 | { | |
466 | case DECL_EXPR: | |
810702a2 | 467 | if (TREE_CODE (DECL_EXPR_DECL (list)) == USING_DECL |
468 | || TREE_CODE (DECL_EXPR_DECL (list)) == TYPE_DECL) | |
09b42213 | 469 | return true; |
09b42213 | 470 | return false; |
471 | ||
472 | case CLEANUP_POINT_EXPR: | |
473 | return check_constexpr_ctor_body (last, TREE_OPERAND (list, 0), | |
474 | /*complain=*/false); | |
475 | ||
476 | case BIND_EXPR: | |
477 | if (!check_constexpr_bind_expr_vars (list) | |
478 | || !check_constexpr_ctor_body (last, BIND_EXPR_BODY (list), | |
479 | /*complain=*/false)) | |
480 | return false; | |
481 | return true; | |
482 | ||
483 | case USING_STMT: | |
484 | case STATIC_ASSERT: | |
90567983 | 485 | case DEBUG_BEGIN_STMT: |
09b42213 | 486 | return true; |
487 | ||
488 | default: | |
489 | return false; | |
490 | } | |
491 | } | |
492 | ||
493 | /* Make sure that there are no statements after LAST in the constructor | |
494 | body represented by LIST. */ | |
495 | ||
496 | bool | |
497 | check_constexpr_ctor_body (tree last, tree list, bool complain) | |
498 | { | |
9c96033c | 499 | /* C++14 doesn't require a constexpr ctor to have an empty body. */ |
500 | if (cxx_dialect >= cxx14) | |
501 | return true; | |
502 | ||
09b42213 | 503 | bool ok = true; |
504 | if (TREE_CODE (list) == STATEMENT_LIST) | |
505 | { | |
506 | tree_stmt_iterator i = tsi_last (list); | |
507 | for (; !tsi_end_p (i); tsi_prev (&i)) | |
508 | { | |
509 | tree t = tsi_stmt (i); | |
510 | if (t == last) | |
511 | break; | |
512 | if (!check_constexpr_ctor_body_1 (last, t)) | |
513 | { | |
514 | ok = false; | |
515 | break; | |
516 | } | |
517 | } | |
518 | } | |
519 | else if (list != last | |
520 | && !check_constexpr_ctor_body_1 (last, list)) | |
521 | ok = false; | |
522 | if (!ok) | |
523 | { | |
524 | if (complain) | |
5967b28b | 525 | error ("%<constexpr%> constructor does not have empty body"); |
09b42213 | 526 | DECL_DECLARED_CONSTEXPR_P (current_function_decl) = false; |
527 | } | |
528 | return ok; | |
529 | } | |
530 | ||
531 | /* V is a vector of constructor elements built up for the base and member | |
532 | initializers of a constructor for TYPE. They need to be in increasing | |
533 | offset order, which they might not be yet if TYPE has a primary base | |
534 | which is not first in the base-clause or a vptr and at least one base | |
535 | all of which are non-primary. */ | |
536 | ||
537 | static vec<constructor_elt, va_gc> * | |
538 | sort_constexpr_mem_initializers (tree type, vec<constructor_elt, va_gc> *v) | |
539 | { | |
540 | tree pri = CLASSTYPE_PRIMARY_BINFO (type); | |
541 | tree field_type; | |
542 | unsigned i; | |
543 | constructor_elt *ce; | |
544 | ||
545 | if (pri) | |
546 | field_type = BINFO_TYPE (pri); | |
547 | else if (TYPE_CONTAINS_VPTR_P (type)) | |
548 | field_type = vtbl_ptr_type_node; | |
549 | else | |
550 | return v; | |
551 | ||
552 | /* Find the element for the primary base or vptr and move it to the | |
553 | beginning of the vec. */ | |
554 | for (i = 0; vec_safe_iterate (v, i, &ce); ++i) | |
555 | if (TREE_TYPE (ce->index) == field_type) | |
556 | break; | |
557 | ||
558 | if (i > 0 && i < vec_safe_length (v)) | |
559 | { | |
560 | vec<constructor_elt, va_gc> &vref = *v; | |
561 | constructor_elt elt = vref[i]; | |
562 | for (; i > 0; --i) | |
563 | vref[i] = vref[i-1]; | |
564 | vref[0] = elt; | |
565 | } | |
566 | ||
567 | return v; | |
568 | } | |
569 | ||
570 | /* Build compile-time evalable representations of member-initializer list | |
571 | for a constexpr constructor. */ | |
572 | ||
573 | static tree | |
574 | build_constexpr_constructor_member_initializers (tree type, tree body) | |
575 | { | |
576 | vec<constructor_elt, va_gc> *vec = NULL; | |
577 | bool ok = true; | |
816919e1 | 578 | while (true) |
579 | switch (TREE_CODE (body)) | |
580 | { | |
581 | case MUST_NOT_THROW_EXPR: | |
582 | case EH_SPEC_BLOCK: | |
583 | body = TREE_OPERAND (body, 0); | |
584 | break; | |
585 | ||
586 | case STATEMENT_LIST: | |
587 | for (tree_stmt_iterator i = tsi_start (body); | |
588 | !tsi_end_p (i); tsi_next (&i)) | |
589 | { | |
590 | body = tsi_stmt (i); | |
591 | if (TREE_CODE (body) == BIND_EXPR) | |
592 | break; | |
593 | } | |
594 | break; | |
595 | ||
596 | case BIND_EXPR: | |
597 | body = BIND_EXPR_BODY (body); | |
598 | goto found; | |
599 | ||
600 | default: | |
601 | gcc_unreachable (); | |
8a36d0ec | 602 | } |
816919e1 | 603 | found: |
b279a142 | 604 | if (TREE_CODE (body) == TRY_BLOCK) |
605 | { | |
606 | body = TREE_OPERAND (body, 0); | |
607 | if (TREE_CODE (body) == BIND_EXPR) | |
608 | body = BIND_EXPR_BODY (body); | |
609 | } | |
09b42213 | 610 | if (TREE_CODE (body) == CLEANUP_POINT_EXPR) |
611 | { | |
612 | body = TREE_OPERAND (body, 0); | |
613 | if (TREE_CODE (body) == EXPR_STMT) | |
614 | body = TREE_OPERAND (body, 0); | |
615 | if (TREE_CODE (body) == INIT_EXPR | |
616 | && (same_type_ignoring_top_level_qualifiers_p | |
617 | (TREE_TYPE (TREE_OPERAND (body, 0)), | |
618 | current_class_type))) | |
619 | { | |
620 | /* Trivial copy. */ | |
621 | return TREE_OPERAND (body, 1); | |
622 | } | |
623 | ok = build_data_member_initialization (body, &vec); | |
624 | } | |
625 | else if (TREE_CODE (body) == STATEMENT_LIST) | |
626 | { | |
627 | tree_stmt_iterator i; | |
628 | for (i = tsi_start (body); !tsi_end_p (i); tsi_next (&i)) | |
629 | { | |
630 | ok = build_data_member_initialization (tsi_stmt (i), &vec); | |
631 | if (!ok) | |
632 | break; | |
633 | } | |
634 | } | |
09b42213 | 635 | else if (EXPR_P (body)) |
636 | ok = build_data_member_initialization (body, &vec); | |
637 | else | |
638 | gcc_assert (errorcount > 0); | |
639 | if (ok) | |
640 | { | |
641 | if (vec_safe_length (vec) > 0) | |
642 | { | |
643 | /* In a delegating constructor, return the target. */ | |
644 | constructor_elt *ce = &(*vec)[0]; | |
645 | if (ce->index == current_class_ptr) | |
646 | { | |
647 | body = ce->value; | |
648 | vec_free (vec); | |
649 | return body; | |
650 | } | |
651 | } | |
652 | vec = sort_constexpr_mem_initializers (type, vec); | |
653 | return build_constructor (type, vec); | |
654 | } | |
655 | else | |
656 | return error_mark_node; | |
657 | } | |
658 | ||
2fb20ba2 | 659 | /* We have an expression tree T that represents a call, either CALL_EXPR |
660 | or AGGR_INIT_EXPR. If the call is lexically to a named function, | |
661 | retrun the _DECL for that function. */ | |
662 | ||
663 | static tree | |
664 | get_function_named_in_call (tree t) | |
665 | { | |
666 | tree fun = cp_get_callee (t); | |
667 | if (fun && TREE_CODE (fun) == ADDR_EXPR | |
668 | && TREE_CODE (TREE_OPERAND (fun, 0)) == FUNCTION_DECL) | |
669 | fun = TREE_OPERAND (fun, 0); | |
670 | return fun; | |
671 | } | |
672 | ||
09b42213 | 673 | /* Subroutine of register_constexpr_fundef. BODY is the body of a function |
674 | declared to be constexpr, or a sub-statement thereof. Returns the | |
675 | return value if suitable, error_mark_node for a statement not allowed in | |
676 | a constexpr function, or NULL_TREE if no return value was found. */ | |
677 | ||
c49bd35e | 678 | tree |
09b42213 | 679 | constexpr_fn_retval (tree body) |
680 | { | |
681 | switch (TREE_CODE (body)) | |
682 | { | |
683 | case STATEMENT_LIST: | |
684 | { | |
685 | tree_stmt_iterator i; | |
686 | tree expr = NULL_TREE; | |
687 | for (i = tsi_start (body); !tsi_end_p (i); tsi_next (&i)) | |
688 | { | |
689 | tree s = constexpr_fn_retval (tsi_stmt (i)); | |
690 | if (s == error_mark_node) | |
691 | return error_mark_node; | |
692 | else if (s == NULL_TREE) | |
693 | /* Keep iterating. */; | |
694 | else if (expr) | |
695 | /* Multiple return statements. */ | |
696 | return error_mark_node; | |
697 | else | |
698 | expr = s; | |
699 | } | |
700 | return expr; | |
701 | } | |
702 | ||
703 | case RETURN_EXPR: | |
704 | return break_out_target_exprs (TREE_OPERAND (body, 0)); | |
705 | ||
706 | case DECL_EXPR: | |
394aed6a | 707 | { |
708 | tree decl = DECL_EXPR_DECL (body); | |
709 | if (TREE_CODE (decl) == USING_DECL | |
710 | /* Accept __func__, __FUNCTION__, and __PRETTY_FUNCTION__. */ | |
711 | || DECL_ARTIFICIAL (decl)) | |
712 | return NULL_TREE; | |
713 | return error_mark_node; | |
714 | } | |
09b42213 | 715 | |
716 | case CLEANUP_POINT_EXPR: | |
717 | return constexpr_fn_retval (TREE_OPERAND (body, 0)); | |
718 | ||
719 | case BIND_EXPR: | |
720 | if (!check_constexpr_bind_expr_vars (body)) | |
721 | return error_mark_node; | |
722 | return constexpr_fn_retval (BIND_EXPR_BODY (body)); | |
723 | ||
724 | case USING_STMT: | |
90567983 | 725 | case DEBUG_BEGIN_STMT: |
09b42213 | 726 | return NULL_TREE; |
727 | ||
2fb20ba2 | 728 | case CALL_EXPR: |
729 | { | |
730 | tree fun = get_function_named_in_call (body); | |
731 | if (fun != NULL_TREE | |
a0e9bfbb | 732 | && fndecl_built_in_p (fun, BUILT_IN_UNREACHABLE)) |
2fb20ba2 | 733 | return NULL_TREE; |
734 | } | |
735 | /* Fallthru. */ | |
736 | ||
09b42213 | 737 | default: |
738 | return error_mark_node; | |
739 | } | |
740 | } | |
741 | ||
742 | /* Subroutine of register_constexpr_fundef. BODY is the DECL_SAVED_TREE of | |
743 | FUN; do the necessary transformations to turn it into a single expression | |
744 | that we can store in the hash table. */ | |
745 | ||
746 | static tree | |
747 | massage_constexpr_body (tree fun, tree body) | |
748 | { | |
749 | if (DECL_CONSTRUCTOR_P (fun)) | |
750 | body = build_constexpr_constructor_member_initializers | |
751 | (DECL_CONTEXT (fun), body); | |
9c96033c | 752 | else if (cxx_dialect < cxx14) |
09b42213 | 753 | { |
754 | if (TREE_CODE (body) == EH_SPEC_BLOCK) | |
755 | body = EH_SPEC_STMTS (body); | |
756 | if (TREE_CODE (body) == MUST_NOT_THROW_EXPR) | |
757 | body = TREE_OPERAND (body, 0); | |
758 | body = constexpr_fn_retval (body); | |
759 | } | |
760 | return body; | |
761 | } | |
762 | ||
2f4cab3c | 763 | /* CTYPE is a type constructed from BODY. Return true if some |
764 | bases/fields are uninitialized, and complain if COMPLAIN. */ | |
09b42213 | 765 | |
766 | static bool | |
2f4cab3c | 767 | cx_check_missing_mem_inits (tree ctype, tree body, bool complain) |
09b42213 | 768 | { |
2f4cab3c | 769 | unsigned nelts = 0; |
770 | ||
771 | if (body) | |
772 | { | |
773 | if (TREE_CODE (body) != CONSTRUCTOR) | |
774 | return false; | |
775 | nelts = CONSTRUCTOR_NELTS (body); | |
776 | } | |
777 | tree field = TYPE_FIELDS (ctype); | |
09b42213 | 778 | |
779 | if (TREE_CODE (ctype) == UNION_TYPE) | |
780 | { | |
781 | if (nelts == 0 && next_initializable_field (field)) | |
782 | { | |
783 | if (complain) | |
784 | error ("%<constexpr%> constructor for union %qT must " | |
785 | "initialize exactly one non-static data member", ctype); | |
786 | return true; | |
787 | } | |
788 | return false; | |
789 | } | |
790 | ||
2f4cab3c | 791 | /* Iterate over the CONSTRUCTOR, checking any missing fields don't |
792 | need an explicit initialization. */ | |
793 | bool bad = false; | |
794 | for (unsigned i = 0; i <= nelts; ++i) | |
09b42213 | 795 | { |
2f4cab3c | 796 | tree index = NULL_TREE; |
797 | if (i < nelts) | |
09b42213 | 798 | { |
799 | index = CONSTRUCTOR_ELT (body, i)->index; | |
800 | /* Skip base and vtable inits. */ | |
801 | if (TREE_CODE (index) != FIELD_DECL | |
802 | || DECL_ARTIFICIAL (index)) | |
803 | continue; | |
804 | } | |
2f4cab3c | 805 | |
09b42213 | 806 | for (; field != index; field = DECL_CHAIN (field)) |
807 | { | |
808 | tree ftype; | |
2f4cab3c | 809 | if (TREE_CODE (field) != FIELD_DECL) |
810 | continue; | |
3cde3c29 | 811 | if (DECL_UNNAMED_BIT_FIELD (field)) |
09b42213 | 812 | continue; |
2f4cab3c | 813 | if (DECL_ARTIFICIAL (field)) |
814 | continue; | |
815 | if (ANON_AGGR_TYPE_P (TREE_TYPE (field))) | |
816 | { | |
817 | /* Recurse to check the anonummous aggregate member. */ | |
818 | bad |= cx_check_missing_mem_inits | |
819 | (TREE_TYPE (field), NULL_TREE, complain); | |
820 | if (bad && !complain) | |
821 | return true; | |
822 | continue; | |
823 | } | |
09b42213 | 824 | ftype = strip_array_types (TREE_TYPE (field)); |
825 | if (type_has_constexpr_default_constructor (ftype)) | |
826 | { | |
827 | /* It's OK to skip a member with a trivial constexpr ctor. | |
828 | A constexpr ctor that isn't trivial should have been | |
829 | added in by now. */ | |
830 | gcc_checking_assert (!TYPE_HAS_COMPLEX_DFLT (ftype) | |
831 | || errorcount != 0); | |
832 | continue; | |
833 | } | |
834 | if (!complain) | |
835 | return true; | |
bc35ef65 | 836 | auto_diagnostic_group d; |
859e2c29 | 837 | error ("member %qD must be initialized by mem-initializer " |
838 | "in %<constexpr%> constructor", field); | |
839 | inform (DECL_SOURCE_LOCATION (field), "declared here"); | |
09b42213 | 840 | bad = true; |
841 | } | |
842 | if (field == NULL_TREE) | |
843 | break; | |
2f4cab3c | 844 | |
845 | if (ANON_AGGR_TYPE_P (TREE_TYPE (index))) | |
846 | { | |
847 | /* Check the anonymous aggregate initializer is valid. */ | |
848 | bad |= cx_check_missing_mem_inits | |
849 | (TREE_TYPE (index), CONSTRUCTOR_ELT (body, i)->value, complain); | |
850 | if (bad && !complain) | |
851 | return true; | |
852 | } | |
09b42213 | 853 | field = DECL_CHAIN (field); |
854 | } | |
855 | ||
856 | return bad; | |
857 | } | |
858 | ||
859 | /* We are processing the definition of the constexpr function FUN. | |
860 | Check that its BODY fulfills the propriate requirements and | |
861 | enter it in the constexpr function definition table. | |
862 | For constructor BODY is actually the TREE_LIST of the | |
863 | member-initializer list. */ | |
864 | ||
865 | tree | |
866 | register_constexpr_fundef (tree fun, tree body) | |
867 | { | |
868 | constexpr_fundef entry; | |
869 | constexpr_fundef **slot; | |
870 | ||
871 | if (!is_valid_constexpr_fn (fun, !DECL_GENERATED_P (fun))) | |
872 | return NULL; | |
873 | ||
6a385150 | 874 | tree massaged = massage_constexpr_body (fun, body); |
875 | if (massaged == NULL_TREE || massaged == error_mark_node) | |
09b42213 | 876 | { |
877 | if (!DECL_CONSTRUCTOR_P (fun)) | |
5967b28b | 878 | error ("body of %<constexpr%> function %qD not a return-statement", |
879 | fun); | |
09b42213 | 880 | return NULL; |
881 | } | |
882 | ||
6a385150 | 883 | if (!potential_rvalue_constant_expression (massaged)) |
09b42213 | 884 | { |
885 | if (!DECL_GENERATED_P (fun)) | |
6a385150 | 886 | require_potential_rvalue_constant_expression (massaged); |
09b42213 | 887 | return NULL; |
888 | } | |
889 | ||
890 | if (DECL_CONSTRUCTOR_P (fun) | |
2f4cab3c | 891 | && cx_check_missing_mem_inits (DECL_CONTEXT (fun), |
892 | massaged, !DECL_GENERATED_P (fun))) | |
09b42213 | 893 | return NULL; |
894 | ||
895 | /* Create the constexpr function table if necessary. */ | |
896 | if (constexpr_fundef_table == NULL) | |
897 | constexpr_fundef_table | |
898 | = hash_table<constexpr_fundef_hasher>::create_ggc (101); | |
899 | ||
900 | entry.decl = fun; | |
02d7a132 | 901 | tree saved_fn = current_function_decl; |
902 | bool clear_ctx = false; | |
903 | current_function_decl = fun; | |
904 | if (DECL_RESULT (fun) && DECL_CONTEXT (DECL_RESULT (fun)) == NULL_TREE) | |
905 | { | |
906 | clear_ctx = true; | |
907 | DECL_CONTEXT (DECL_RESULT (fun)) = fun; | |
908 | } | |
909 | entry.body = copy_fn (fun, entry.parms, entry.result); | |
910 | current_function_decl = saved_fn; | |
09b42213 | 911 | slot = constexpr_fundef_table->find_slot (&entry, INSERT); |
02d7a132 | 912 | if (clear_ctx) |
913 | DECL_CONTEXT (DECL_RESULT (fun)) = NULL_TREE; | |
09b42213 | 914 | |
915 | gcc_assert (*slot == NULL); | |
916 | *slot = ggc_alloc<constexpr_fundef> (); | |
917 | **slot = entry; | |
918 | ||
919 | return fun; | |
920 | } | |
921 | ||
922 | /* FUN is a non-constexpr function called in a context that requires a | |
923 | constant expression. If it comes from a constexpr template, explain why | |
924 | the instantiation isn't constexpr. */ | |
925 | ||
926 | void | |
927 | explain_invalid_constexpr_fn (tree fun) | |
928 | { | |
929 | static hash_set<tree> *diagnosed; | |
930 | tree body; | |
931 | location_t save_loc; | |
33603066 | 932 | /* Only diagnose defaulted functions, lambdas, or instantiations. */ |
09b42213 | 933 | if (!DECL_DEFAULTED_FN (fun) |
33603066 | 934 | && !LAMBDA_TYPE_P (CP_DECL_CONTEXT (fun)) |
09b42213 | 935 | && !is_instantiation_of_constexpr (fun)) |
936 | return; | |
937 | if (diagnosed == NULL) | |
938 | diagnosed = new hash_set<tree>; | |
939 | if (diagnosed->add (fun)) | |
940 | /* Already explained. */ | |
941 | return; | |
942 | ||
943 | save_loc = input_location; | |
33603066 | 944 | if (!lambda_static_thunk_p (fun)) |
945 | { | |
946 | /* Diagnostics should completely ignore the static thunk, so leave | |
947 | input_location set to our caller's location. */ | |
948 | input_location = DECL_SOURCE_LOCATION (fun); | |
949 | inform (input_location, | |
5967b28b | 950 | "%qD is not usable as a %<constexpr%> function because:", fun); |
33603066 | 951 | } |
09b42213 | 952 | /* First check the declaration. */ |
953 | if (is_valid_constexpr_fn (fun, true)) | |
954 | { | |
955 | /* Then if it's OK, the body. */ | |
33603066 | 956 | if (!DECL_DECLARED_CONSTEXPR_P (fun) |
957 | && !LAMBDA_TYPE_P (CP_DECL_CONTEXT (fun))) | |
09b42213 | 958 | explain_implicit_non_constexpr (fun); |
959 | else | |
960 | { | |
961 | body = massage_constexpr_body (fun, DECL_SAVED_TREE (fun)); | |
962 | require_potential_rvalue_constant_expression (body); | |
963 | if (DECL_CONSTRUCTOR_P (fun)) | |
2f4cab3c | 964 | cx_check_missing_mem_inits (DECL_CONTEXT (fun), body, true); |
09b42213 | 965 | } |
966 | } | |
967 | input_location = save_loc; | |
968 | } | |
969 | ||
970 | /* Objects of this type represent calls to constexpr functions | |
971 | along with the bindings of parameters to their arguments, for | |
972 | the purpose of compile time evaluation. */ | |
973 | ||
974 | struct GTY((for_user)) constexpr_call { | |
975 | /* Description of the constexpr function definition. */ | |
976 | constexpr_fundef *fundef; | |
7a429a9d | 977 | /* Parameter bindings environment. A TREE_VEC of arguments. */ |
09b42213 | 978 | tree bindings; |
979 | /* Result of the call. | |
980 | NULL means the call is being evaluated. | |
981 | error_mark_node means that the evaluation was erroneous; | |
982 | otherwise, the actuall value of the call. */ | |
983 | tree result; | |
984 | /* The hash of this call; we remember it here to avoid having to | |
985 | recalculate it when expanding the hash table. */ | |
986 | hashval_t hash; | |
919873c7 | 987 | /* Whether __builtin_is_constant_evaluated() should evaluate to true. */ |
1562c831 | 988 | bool manifestly_const_eval; |
09b42213 | 989 | }; |
990 | ||
b594087e | 991 | struct constexpr_call_hasher : ggc_ptr_hash<constexpr_call> |
09b42213 | 992 | { |
993 | static hashval_t hash (constexpr_call *); | |
994 | static bool equal (constexpr_call *, constexpr_call *); | |
cf72f34d | 995 | }; |
996 | ||
2a2770c6 | 997 | enum constexpr_switch_state { |
998 | /* Used when processing a switch for the first time by cxx_eval_switch_expr | |
999 | and default: label for that switch has not been seen yet. */ | |
1000 | css_default_not_seen, | |
1001 | /* Used when processing a switch for the first time by cxx_eval_switch_expr | |
1002 | and default: label for that switch has been seen already. */ | |
1003 | css_default_seen, | |
1004 | /* Used when processing a switch for the second time by | |
1005 | cxx_eval_switch_expr, where default: label should match. */ | |
1006 | css_default_processing | |
1007 | }; | |
1008 | ||
cf72f34d | 1009 | /* The constexpr expansion context. CALL is the current function |
1010 | expansion, CTOR is the current aggregate initializer, OBJECT is the | |
1011 | object being initialized by CTOR, either a VAR_DECL or a _REF. VALUES | |
1012 | is a map of values of variables initialized within the expression. */ | |
1013 | ||
1014 | struct constexpr_ctx { | |
f9885b8a | 1015 | /* The innermost call we're evaluating. */ |
cf72f34d | 1016 | constexpr_call *call; |
f9885b8a | 1017 | /* Values for any temporaries or local variables within the |
1018 | constant-expression. */ | |
cf72f34d | 1019 | hash_map<tree,tree> *values; |
2631cb67 | 1020 | /* SAVE_EXPRs that we've seen within the current LOOP_EXPR. NULL if we |
1021 | aren't inside a loop. */ | |
d0782a7e | 1022 | vec<tree> *save_exprs; |
f9885b8a | 1023 | /* The CONSTRUCTOR we're currently building up for an aggregate |
1024 | initializer. */ | |
cf72f34d | 1025 | tree ctor; |
f9885b8a | 1026 | /* The object we're building the CONSTRUCTOR for. */ |
cf72f34d | 1027 | tree object; |
2a2770c6 | 1028 | /* If inside SWITCH_EXPR. */ |
1029 | constexpr_switch_state *css_state; | |
84f13b2f | 1030 | /* Number of cxx_eval_constant_expression calls (except skipped ones, |
1031 | on simple constants or location wrappers) encountered during current | |
1032 | cxx_eval_outermost_constant_expr call. */ | |
1033 | HOST_WIDE_INT *constexpr_ops_count; | |
1034 | ||
f9885b8a | 1035 | /* Whether we should error on a non-constant expression or fail quietly. */ |
f83e6885 | 1036 | bool quiet; |
f9885b8a | 1037 | /* Whether we are strictly conforming to constant expression rules or |
1038 | trying harder to get a constant value. */ | |
2055d27a | 1039 | bool strict; |
18d371d3 | 1040 | /* Whether __builtin_is_constant_evaluated () should be true. */ |
1562c831 | 1041 | bool manifestly_const_eval; |
cf72f34d | 1042 | }; |
09b42213 | 1043 | |
1044 | /* A table of all constexpr calls that have been evaluated by the | |
1045 | compiler in this translation unit. */ | |
1046 | ||
a050099a | 1047 | static GTY (()) hash_table<constexpr_call_hasher> *constexpr_call_table; |
09b42213 | 1048 | |
cf72f34d | 1049 | static tree cxx_eval_constant_expression (const constexpr_ctx *, tree, |
b2a43197 | 1050 | bool, bool *, bool *, tree * = NULL); |
09b42213 | 1051 | |
1052 | /* Compute a hash value for a constexpr call representation. */ | |
1053 | ||
1054 | inline hashval_t | |
1055 | constexpr_call_hasher::hash (constexpr_call *info) | |
1056 | { | |
1057 | return info->hash; | |
1058 | } | |
1059 | ||
1060 | /* Return true if the objects pointed to by P and Q represent calls | |
1061 | to the same constexpr function with the same arguments. | |
1062 | Otherwise, return false. */ | |
1063 | ||
1064 | bool | |
1065 | constexpr_call_hasher::equal (constexpr_call *lhs, constexpr_call *rhs) | |
1066 | { | |
09b42213 | 1067 | if (lhs == rhs) |
c751e2cd | 1068 | return true; |
1069 | if (lhs->hash != rhs->hash) | |
1070 | return false; | |
1562c831 | 1071 | if (lhs->manifestly_const_eval != rhs->manifestly_const_eval) |
919873c7 | 1072 | return false; |
09b42213 | 1073 | if (!constexpr_fundef_hasher::equal (lhs->fundef, rhs->fundef)) |
c751e2cd | 1074 | return false; |
7a429a9d | 1075 | return cp_tree_equal (lhs->bindings, rhs->bindings); |
09b42213 | 1076 | } |
1077 | ||
1078 | /* Initialize the constexpr call table, if needed. */ | |
1079 | ||
1080 | static void | |
1081 | maybe_initialize_constexpr_call_table (void) | |
1082 | { | |
1083 | if (constexpr_call_table == NULL) | |
1084 | constexpr_call_table = hash_table<constexpr_call_hasher>::create_ggc (101); | |
1085 | } | |
1086 | ||
4f7ebe46 | 1087 | /* During constexpr CALL_EXPR evaluation, to avoid issues with sharing when |
1088 | a function happens to get called recursively, we unshare the callee | |
1089 | function's body and evaluate this unshared copy instead of evaluating the | |
1090 | original body. | |
1091 | ||
1092 | FUNDEF_COPIES_TABLE is a per-function freelist of these unshared function | |
1093 | copies. The underlying data structure of FUNDEF_COPIES_TABLE is a hash_map | |
a050099a | 1094 | that's keyed off of the original FUNCTION_DECL and whose value is a |
1095 | TREE_LIST of this function's unused copies awaiting reuse. | |
4f7ebe46 | 1096 | |
a050099a | 1097 | This is not GC-deletable to avoid GC affecting UID generation. */ |
4f7ebe46 | 1098 | |
a050099a | 1099 | static GTY(()) hash_map<tree, tree> *fundef_copies_table; |
4f7ebe46 | 1100 | |
1101 | /* Initialize FUNDEF_COPIES_TABLE if it's not initialized. */ | |
1102 | ||
1103 | static void | |
1104 | maybe_initialize_fundef_copies_table () | |
1105 | { | |
a050099a | 1106 | if (fundef_copies_table == NULL) |
1107 | fundef_copies_table = hash_map<tree,tree>::create_ggc (101); | |
4f7ebe46 | 1108 | } |
1109 | ||
1110 | /* Reuse a copy or create a new unshared copy of the function FUN. | |
886d5463 | 1111 | Return this copy. We use a TREE_LIST whose PURPOSE is body, VALUE |
1112 | is parms, TYPE is result. */ | |
4f7ebe46 | 1113 | |
a050099a | 1114 | static tree |
02d7a132 | 1115 | get_fundef_copy (constexpr_fundef *fundef) |
4f7ebe46 | 1116 | { |
1117 | maybe_initialize_fundef_copies_table (); | |
1118 | ||
a050099a | 1119 | tree copy; |
886d5463 | 1120 | bool existed; |
02d7a132 | 1121 | tree *slot = &fundef_copies_table->get_or_insert (fundef->decl, &existed); |
886d5463 | 1122 | |
1123 | if (!existed) | |
4f7ebe46 | 1124 | { |
886d5463 | 1125 | /* There is no cached function available, or in use. We can use |
1126 | the function directly. That the slot is now created records | |
1127 | that this function is now in use. */ | |
02d7a132 | 1128 | copy = build_tree_list (fundef->body, fundef->parms); |
1129 | TREE_TYPE (copy) = fundef->result; | |
886d5463 | 1130 | } |
1131 | else if (*slot == NULL_TREE) | |
1132 | { | |
1133 | /* We've already used the function itself, so make a copy. */ | |
a050099a | 1134 | copy = build_tree_list (NULL, NULL); |
02d7a132 | 1135 | tree saved_body = DECL_SAVED_TREE (fundef->decl); |
1136 | tree saved_parms = DECL_ARGUMENTS (fundef->decl); | |
1137 | tree saved_result = DECL_RESULT (fundef->decl); | |
1138 | tree saved_fn = current_function_decl; | |
1139 | DECL_SAVED_TREE (fundef->decl) = fundef->body; | |
1140 | DECL_ARGUMENTS (fundef->decl) = fundef->parms; | |
1141 | DECL_RESULT (fundef->decl) = fundef->result; | |
1142 | current_function_decl = fundef->decl; | |
1143 | TREE_PURPOSE (copy) = copy_fn (fundef->decl, TREE_VALUE (copy), | |
1144 | TREE_TYPE (copy)); | |
1145 | current_function_decl = saved_fn; | |
1146 | DECL_RESULT (fundef->decl) = saved_result; | |
1147 | DECL_ARGUMENTS (fundef->decl) = saved_parms; | |
1148 | DECL_SAVED_TREE (fundef->decl) = saved_body; | |
4f7ebe46 | 1149 | } |
1150 | else | |
1151 | { | |
886d5463 | 1152 | /* We have a cached function available. */ |
4f7ebe46 | 1153 | copy = *slot; |
a050099a | 1154 | *slot = TREE_CHAIN (copy); |
4f7ebe46 | 1155 | } |
1156 | ||
1157 | return copy; | |
1158 | } | |
1159 | ||
886d5463 | 1160 | /* Save the copy COPY of function FUN for later reuse by |
1161 | get_fundef_copy(). By construction, there will always be an entry | |
1162 | to find. */ | |
4f7ebe46 | 1163 | |
1164 | static void | |
a050099a | 1165 | save_fundef_copy (tree fun, tree copy) |
4f7ebe46 | 1166 | { |
886d5463 | 1167 | tree *slot = fundef_copies_table->get (fun); |
a050099a | 1168 | TREE_CHAIN (copy) = *slot; |
4f7ebe46 | 1169 | *slot = copy; |
1170 | } | |
1171 | ||
09b42213 | 1172 | /* We have an expression tree T that represents a call, either CALL_EXPR |
1173 | or AGGR_INIT_EXPR. Return the Nth argument. */ | |
1174 | ||
1175 | static inline tree | |
1176 | get_nth_callarg (tree t, int n) | |
1177 | { | |
1178 | switch (TREE_CODE (t)) | |
1179 | { | |
1180 | case CALL_EXPR: | |
1181 | return CALL_EXPR_ARG (t, n); | |
1182 | ||
1183 | case AGGR_INIT_EXPR: | |
1184 | return AGGR_INIT_EXPR_ARG (t, n); | |
1185 | ||
1186 | default: | |
1187 | gcc_unreachable (); | |
1188 | return NULL; | |
1189 | } | |
1190 | } | |
1191 | ||
09b42213 | 1192 | /* Attempt to evaluate T which represents a call to a builtin function. |
1193 | We assume here that all builtin functions evaluate to scalar types | |
1194 | represented by _CST nodes. */ | |
1195 | ||
1196 | static tree | |
f1c6af10 | 1197 | cxx_eval_builtin_function_call (const constexpr_ctx *ctx, tree t, tree fun, |
1227ba74 | 1198 | bool lval, |
09b42213 | 1199 | bool *non_constant_p, bool *overflow_p) |
1200 | { | |
1201 | const int nargs = call_expr_nargs (t); | |
1202 | tree *args = (tree *) alloca (nargs * sizeof (tree)); | |
1203 | tree new_call; | |
1204 | int i; | |
f1c6af10 | 1205 | |
1206 | /* Don't fold __builtin_constant_p within a constexpr function. */ | |
18d371d3 | 1207 | bool bi_const_p = DECL_IS_BUILTIN_CONSTANT_P (fun); |
efe6a40a | 1208 | |
0f5cec54 | 1209 | /* If we aren't requiring a constant expression, defer __builtin_constant_p |
1210 | in a constexpr function until we have values for the parameters. */ | |
efe6a40a | 1211 | if (bi_const_p |
4749c4ac | 1212 | && !ctx->manifestly_const_eval |
f1c6af10 | 1213 | && current_function_decl |
1214 | && DECL_DECLARED_CONSTEXPR_P (current_function_decl)) | |
09b42213 | 1215 | { |
f1c6af10 | 1216 | *non_constant_p = true; |
1217 | return t; | |
09b42213 | 1218 | } |
f1c6af10 | 1219 | |
18d371d3 | 1220 | /* For __builtin_is_constant_evaluated, defer it if not |
1562c831 | 1221 | ctx->manifestly_const_eval, otherwise fold it to true. */ |
a0e9bfbb | 1222 | if (fndecl_built_in_p (fun, CP_BUILT_IN_IS_CONSTANT_EVALUATED, |
1562c831 | 1223 | BUILT_IN_FRONTEND)) |
18d371d3 | 1224 | { |
1562c831 | 1225 | if (!ctx->manifestly_const_eval) |
18d371d3 | 1226 | { |
1227 | *non_constant_p = true; | |
1228 | return t; | |
1229 | } | |
1230 | return boolean_true_node; | |
1231 | } | |
1232 | ||
f1c6af10 | 1233 | /* Be permissive for arguments to built-ins; __builtin_constant_p should |
1234 | return constant false for a non-constant argument. */ | |
1235 | constexpr_ctx new_ctx = *ctx; | |
1236 | new_ctx.quiet = true; | |
f1c6af10 | 1237 | for (i = 0; i < nargs; ++i) |
efe6a40a | 1238 | { |
91b66c3c | 1239 | args[i] = CALL_EXPR_ARG (t, i); |
1240 | /* If builtin_valid_in_constant_expr_p is true, | |
1241 | potential_constant_expression_1 has not recursed into the arguments | |
1242 | of the builtin, verify it here. */ | |
1243 | if (!builtin_valid_in_constant_expr_p (fun) | |
1244 | || potential_constant_expression (args[i])) | |
4749c4ac | 1245 | { |
1246 | bool dummy1 = false, dummy2 = false; | |
1247 | args[i] = cxx_eval_constant_expression (&new_ctx, args[i], false, | |
1248 | &dummy1, &dummy2); | |
1249 | } | |
1250 | ||
efe6a40a | 1251 | if (bi_const_p) |
4749c4ac | 1252 | /* For __builtin_constant_p, fold all expressions with constant values |
efe6a40a | 1253 | even if they aren't C++ constant-expressions. */ |
4749c4ac | 1254 | args[i] = cp_fold_rvalue (args[i]); |
efe6a40a | 1255 | } |
f1c6af10 | 1256 | |
1257 | bool save_ffbcp = force_folding_builtin_constant_p; | |
1258 | force_folding_builtin_constant_p = true; | |
02d7a132 | 1259 | tree save_cur_fn = current_function_decl; |
1260 | /* Return name of ctx->call->fundef->decl for __builtin_FUNCTION (). */ | |
1261 | if (fndecl_built_in_p (fun, BUILT_IN_FUNCTION) | |
1262 | && ctx->call | |
1263 | && ctx->call->fundef) | |
1264 | current_function_decl = ctx->call->fundef->decl; | |
051eb924 | 1265 | new_call = fold_builtin_call_array (EXPR_LOCATION (t), TREE_TYPE (t), |
1266 | CALL_EXPR_FN (t), nargs, args); | |
02d7a132 | 1267 | current_function_decl = save_cur_fn; |
f1c6af10 | 1268 | force_folding_builtin_constant_p = save_ffbcp; |
051eb924 | 1269 | if (new_call == NULL) |
1270 | { | |
1271 | if (!*non_constant_p && !ctx->quiet) | |
1272 | { | |
2fb20ba2 | 1273 | /* Do not allow__builtin_unreachable in constexpr function. |
1274 | The __builtin_unreachable call with BUILTINS_LOCATION | |
1275 | comes from cp_maybe_instrument_return. */ | |
a0e9bfbb | 1276 | if (fndecl_built_in_p (fun, BUILT_IN_UNREACHABLE) |
2fb20ba2 | 1277 | && EXPR_LOCATION (t) == BUILTINS_LOCATION) |
5967b28b | 1278 | error ("%<constexpr%> call flows off the end of the function"); |
2fb20ba2 | 1279 | else |
1280 | { | |
1281 | new_call = build_call_array_loc (EXPR_LOCATION (t), TREE_TYPE (t), | |
1282 | CALL_EXPR_FN (t), nargs, args); | |
1283 | error ("%q+E is not a constant expression", new_call); | |
1284 | } | |
051eb924 | 1285 | } |
1286 | *non_constant_p = true; | |
1287 | return t; | |
1288 | } | |
1289 | ||
02d7a132 | 1290 | if (!potential_constant_expression (new_call)) |
051eb924 | 1291 | { |
1292 | if (!*non_constant_p && !ctx->quiet) | |
1293 | error ("%q+E is not a constant expression", new_call); | |
1294 | *non_constant_p = true; | |
1295 | return t; | |
1296 | } | |
1297 | ||
1298 | return cxx_eval_constant_expression (&new_ctx, new_call, lval, | |
1299 | non_constant_p, overflow_p); | |
09b42213 | 1300 | } |
1301 | ||
1302 | /* TEMP is the constant value of a temporary object of type TYPE. Adjust | |
1303 | the type of the value to match. */ | |
1304 | ||
1305 | static tree | |
1306 | adjust_temp_type (tree type, tree temp) | |
1307 | { | |
6d82dbcd | 1308 | if (same_type_p (TREE_TYPE (temp), type)) |
09b42213 | 1309 | return temp; |
1310 | /* Avoid wrapping an aggregate value in a NOP_EXPR. */ | |
1311 | if (TREE_CODE (temp) == CONSTRUCTOR) | |
c8f861a0 | 1312 | { |
1313 | /* build_constructor wouldn't retain various CONSTRUCTOR flags. */ | |
1314 | tree t = copy_node (temp); | |
1315 | TREE_TYPE (t) = type; | |
1316 | return t; | |
1317 | } | |
71c3d84e | 1318 | if (TREE_CODE (temp) == EMPTY_CLASS_EXPR) |
1319 | return build0 (EMPTY_CLASS_EXPR, type); | |
09b42213 | 1320 | gcc_assert (scalarish_type_p (type)); |
6233ade9 | 1321 | /* Now we know we're dealing with a scalar, and a prvalue of non-class |
1322 | type is cv-unqualified. */ | |
1323 | return cp_fold_convert (cv_unqualified (type), temp); | |
09b42213 | 1324 | } |
1325 | ||
e25c1ab4 | 1326 | /* If T is a CONSTRUCTOR, return an unshared copy of T and any |
1327 | sub-CONSTRUCTORs. Otherwise return T. | |
e283bb4f | 1328 | |
e25c1ab4 | 1329 | We use this whenever we initialize an object as a whole, whether it's a |
1330 | parameter, a local variable, or a subobject, so that subsequent | |
1331 | modifications don't affect other places where it was used. */ | |
e283bb4f | 1332 | |
33e6651d | 1333 | tree |
1dbba015 | 1334 | unshare_constructor (tree t MEM_STAT_DECL) |
e283bb4f | 1335 | { |
e25c1ab4 | 1336 | if (!t || TREE_CODE (t) != CONSTRUCTOR) |
1337 | return t; | |
1338 | auto_vec <tree*, 4> ptrs; | |
1339 | ptrs.safe_push (&t); | |
1340 | while (!ptrs.is_empty ()) | |
1341 | { | |
1342 | tree *p = ptrs.pop (); | |
1dbba015 | 1343 | tree n = copy_node (*p PASS_MEM_STAT); |
1344 | CONSTRUCTOR_ELTS (n) = vec_safe_copy (CONSTRUCTOR_ELTS (*p) PASS_MEM_STAT); | |
e25c1ab4 | 1345 | *p = n; |
1346 | vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (n); | |
1347 | constructor_elt *ce; | |
1348 | for (HOST_WIDE_INT i = 0; vec_safe_iterate (v, i, &ce); ++i) | |
1349 | if (TREE_CODE (ce->value) == CONSTRUCTOR) | |
1350 | ptrs.safe_push (&ce->value); | |
1351 | } | |
e283bb4f | 1352 | return t; |
1353 | } | |
1354 | ||
714c2a31 | 1355 | /* If T is a CONSTRUCTOR, ggc_free T and any sub-CONSTRUCTORs. */ |
1356 | ||
1357 | static void | |
1358 | free_constructor (tree t) | |
1359 | { | |
1360 | if (!t || TREE_CODE (t) != CONSTRUCTOR) | |
1361 | return; | |
1362 | releasing_vec ctors; | |
1363 | vec_safe_push (ctors, t); | |
1364 | while (!ctors->is_empty ()) | |
1365 | { | |
1366 | tree c = ctors->pop (); | |
1367 | if (vec<constructor_elt, va_gc> *elts = CONSTRUCTOR_ELTS (c)) | |
1368 | { | |
1369 | constructor_elt *ce; | |
1370 | for (HOST_WIDE_INT i = 0; vec_safe_iterate (elts, i, &ce); ++i) | |
1371 | if (TREE_CODE (ce->value) == CONSTRUCTOR) | |
1372 | vec_safe_push (ctors, ce->value); | |
1373 | ggc_free (elts); | |
1374 | } | |
1375 | ggc_free (c); | |
1376 | } | |
1377 | } | |
1378 | ||
09b42213 | 1379 | /* Subroutine of cxx_eval_call_expression. |
1380 | We are processing a call expression (either CALL_EXPR or | |
cf72f34d | 1381 | AGGR_INIT_EXPR) in the context of CTX. Evaluate |
09b42213 | 1382 | all arguments and bind their values to correspondings |
1383 | parameters, making up the NEW_CALL context. */ | |
1384 | ||
1385 | static void | |
cf72f34d | 1386 | cxx_bind_parameters_in_call (const constexpr_ctx *ctx, tree t, |
09b42213 | 1387 | constexpr_call *new_call, |
c8f6aeb1 | 1388 | bool *non_constant_p, bool *overflow_p, |
1389 | bool *non_constant_args) | |
09b42213 | 1390 | { |
1391 | const int nargs = call_expr_nargs (t); | |
1392 | tree fun = new_call->fundef->decl; | |
02d7a132 | 1393 | tree parms = new_call->fundef->parms; |
09b42213 | 1394 | int i; |
7a429a9d | 1395 | /* We don't record ellipsis args below. */ |
1396 | int nparms = list_length (parms); | |
1397 | int nbinds = nargs < nparms ? nargs : nparms; | |
1398 | tree binds = new_call->bindings = make_tree_vec (nbinds); | |
09b42213 | 1399 | for (i = 0; i < nargs; ++i) |
1400 | { | |
1401 | tree x, arg; | |
1402 | tree type = parms ? TREE_TYPE (parms) : void_type_node; | |
09b42213 | 1403 | x = get_nth_callarg (t, i); |
cf72f34d | 1404 | /* For member function, the first argument is a pointer to the implied |
1405 | object. For a constructor, it might still be a dummy object, in | |
9c96033c | 1406 | which case we get the real argument from ctx. */ |
cf72f34d | 1407 | if (i == 0 && DECL_CONSTRUCTOR_P (fun) |
1408 | && is_dummy_object (x)) | |
1409 | { | |
1410 | x = ctx->object; | |
c017458d | 1411 | x = build_address (x); |
cf72f34d | 1412 | } |
02d7a132 | 1413 | if (TREE_ADDRESSABLE (type)) |
1414 | /* Undo convert_for_arg_passing work here. */ | |
1415 | x = convert_from_reference (x); | |
2e1c71c2 | 1416 | arg = cxx_eval_constant_expression (ctx, x, /*lval=*/false, |
b2a43197 | 1417 | non_constant_p, overflow_p); |
09b42213 | 1418 | /* Don't VERIFY_CONSTANT here. */ |
f83e6885 | 1419 | if (*non_constant_p && ctx->quiet) |
09b42213 | 1420 | return; |
1421 | /* Just discard ellipsis args after checking their constantitude. */ | |
1422 | if (!parms) | |
1423 | continue; | |
2ba934c7 | 1424 | |
1425 | if (!*non_constant_p) | |
1426 | { | |
714c2a31 | 1427 | /* Unsharing here isn't necessary for correctness, but it |
1428 | significantly improves memory performance for some reason. */ | |
24d5b4f0 | 1429 | arg = unshare_constructor (arg); |
2ba934c7 | 1430 | /* Make sure the binding has the same type as the parm. But |
1431 | only for constant args. */ | |
90ad495b | 1432 | if (!TYPE_REF_P (type)) |
2ba934c7 | 1433 | arg = adjust_temp_type (type, arg); |
1434 | if (!TREE_CONSTANT (arg)) | |
1435 | *non_constant_args = true; | |
7a429a9d | 1436 | TREE_VEC_ELT (binds, i) = arg; |
2ba934c7 | 1437 | } |
09b42213 | 1438 | parms = TREE_CHAIN (parms); |
1439 | } | |
1440 | } | |
1441 | ||
1442 | /* Variables and functions to manage constexpr call expansion context. | |
1443 | These do not need to be marked for PCH or GC. */ | |
1444 | ||
1445 | /* FIXME remember and print actual constant arguments. */ | |
16fb756f | 1446 | static vec<tree> call_stack; |
09b42213 | 1447 | static int call_stack_tick; |
1448 | static int last_cx_error_tick; | |
1449 | ||
1450 | static bool | |
1451 | push_cx_call_context (tree call) | |
1452 | { | |
1453 | ++call_stack_tick; | |
1454 | if (!EXPR_HAS_LOCATION (call)) | |
1455 | SET_EXPR_LOCATION (call, input_location); | |
1456 | call_stack.safe_push (call); | |
1457 | if (call_stack.length () > (unsigned) max_constexpr_depth) | |
1458 | return false; | |
1459 | return true; | |
1460 | } | |
1461 | ||
1462 | static void | |
1463 | pop_cx_call_context (void) | |
1464 | { | |
1465 | ++call_stack_tick; | |
1466 | call_stack.pop (); | |
1467 | } | |
1468 | ||
1469 | vec<tree> | |
1470 | cx_error_context (void) | |
1471 | { | |
1472 | vec<tree> r = vNULL; | |
1473 | if (call_stack_tick != last_cx_error_tick | |
1474 | && !call_stack.is_empty ()) | |
1475 | r = call_stack; | |
1476 | last_cx_error_tick = call_stack_tick; | |
1477 | return r; | |
1478 | } | |
1479 | ||
732905bb | 1480 | /* Evaluate a call T to a GCC internal function when possible and return |
1481 | the evaluated result or, under the control of CTX, give an error, set | |
1482 | NON_CONSTANT_P, and return the unevaluated call T otherwise. */ | |
1483 | ||
1484 | static tree | |
1485 | cxx_eval_internal_function (const constexpr_ctx *ctx, tree t, | |
1486 | bool lval, | |
1487 | bool *non_constant_p, bool *overflow_p) | |
1488 | { | |
1489 | enum tree_code opcode = ERROR_MARK; | |
1490 | ||
1491 | switch (CALL_EXPR_IFN (t)) | |
1492 | { | |
1493 | case IFN_UBSAN_NULL: | |
1494 | case IFN_UBSAN_BOUNDS: | |
1495 | case IFN_UBSAN_VPTR: | |
3c77f69c | 1496 | case IFN_FALLTHROUGH: |
732905bb | 1497 | return void_node; |
1498 | ||
1499 | case IFN_ADD_OVERFLOW: | |
1500 | opcode = PLUS_EXPR; | |
1501 | break; | |
1502 | case IFN_SUB_OVERFLOW: | |
1503 | opcode = MINUS_EXPR; | |
1504 | break; | |
1505 | case IFN_MUL_OVERFLOW: | |
1506 | opcode = MULT_EXPR; | |
1507 | break; | |
1508 | ||
6e1b2ffb | 1509 | case IFN_LAUNDER: |
1510 | return cxx_eval_constant_expression (ctx, CALL_EXPR_ARG (t, 0), | |
1511 | false, non_constant_p, overflow_p); | |
1512 | ||
59409f09 | 1513 | case IFN_VEC_CONVERT: |
1514 | { | |
1515 | tree arg = cxx_eval_constant_expression (ctx, CALL_EXPR_ARG (t, 0), | |
1516 | false, non_constant_p, | |
1517 | overflow_p); | |
1518 | if (TREE_CODE (arg) == VECTOR_CST) | |
1519 | return fold_const_call (CFN_VEC_CONVERT, TREE_TYPE (t), arg); | |
1520 | else | |
1521 | { | |
1522 | *non_constant_p = true; | |
1523 | return t; | |
1524 | } | |
1525 | } | |
1526 | ||
732905bb | 1527 | default: |
1528 | if (!ctx->quiet) | |
d3a3cfb8 | 1529 | error_at (cp_expr_loc_or_loc (t, input_location), |
732905bb | 1530 | "call to internal function %qE", t); |
1531 | *non_constant_p = true; | |
1532 | return t; | |
1533 | } | |
1534 | ||
1535 | /* Evaluate constant arguments using OPCODE and return a complex | |
1536 | number containing the result and the overflow bit. */ | |
1537 | tree arg0 = cxx_eval_constant_expression (ctx, CALL_EXPR_ARG (t, 0), lval, | |
1538 | non_constant_p, overflow_p); | |
1539 | tree arg1 = cxx_eval_constant_expression (ctx, CALL_EXPR_ARG (t, 1), lval, | |
1540 | non_constant_p, overflow_p); | |
1541 | ||
1542 | if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST) | |
1543 | { | |
d3a3cfb8 | 1544 | location_t loc = cp_expr_loc_or_loc (t, input_location); |
732905bb | 1545 | tree type = TREE_TYPE (TREE_TYPE (t)); |
1546 | tree result = fold_binary_loc (loc, opcode, type, | |
1547 | fold_convert_loc (loc, type, arg0), | |
1548 | fold_convert_loc (loc, type, arg1)); | |
1549 | tree ovf | |
1550 | = build_int_cst (type, arith_overflowed_p (opcode, type, arg0, arg1)); | |
1551 | /* Reset TREE_OVERFLOW to avoid warnings for the overflow. */ | |
1552 | if (TREE_OVERFLOW (result)) | |
1553 | TREE_OVERFLOW (result) = 0; | |
1554 | ||
1555 | return build_complex (TREE_TYPE (t), result, ovf); | |
1556 | } | |
1557 | ||
1558 | *non_constant_p = true; | |
1559 | return t; | |
1560 | } | |
1561 | ||
165d0d5b | 1562 | /* Clean CONSTRUCTOR_NO_CLEARING from CTOR and its sub-aggregates. */ |
79cdb4f5 | 1563 | |
1564 | static void | |
1565 | clear_no_implicit_zero (tree ctor) | |
1566 | { | |
165d0d5b | 1567 | if (CONSTRUCTOR_NO_CLEARING (ctor)) |
79cdb4f5 | 1568 | { |
165d0d5b | 1569 | CONSTRUCTOR_NO_CLEARING (ctor) = false; |
79cdb4f5 | 1570 | tree elt; unsigned HOST_WIDE_INT idx; |
1571 | FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), idx, elt) | |
1572 | if (TREE_CODE (elt) == CONSTRUCTOR) | |
1573 | clear_no_implicit_zero (elt); | |
1574 | } | |
1575 | } | |
1576 | ||
09b42213 | 1577 | /* Subroutine of cxx_eval_constant_expression. |
1578 | Evaluate the call expression tree T in the context of OLD_CALL expression | |
1579 | evaluation. */ | |
1580 | ||
1581 | static tree | |
cf72f34d | 1582 | cxx_eval_call_expression (const constexpr_ctx *ctx, tree t, |
1227ba74 | 1583 | bool lval, |
09b42213 | 1584 | bool *non_constant_p, bool *overflow_p) |
1585 | { | |
d3a3cfb8 | 1586 | location_t loc = cp_expr_loc_or_loc (t, input_location); |
09b42213 | 1587 | tree fun = get_function_named_in_call (t); |
919873c7 | 1588 | constexpr_call new_call |
1562c831 | 1589 | = { NULL, NULL, NULL, 0, ctx->manifestly_const_eval }; |
09b42213 | 1590 | bool depth_ok; |
1591 | ||
6b71bdb4 | 1592 | if (fun == NULL_TREE) |
732905bb | 1593 | return cxx_eval_internal_function (ctx, t, lval, |
1594 | non_constant_p, overflow_p); | |
6b71bdb4 | 1595 | |
09b42213 | 1596 | if (TREE_CODE (fun) != FUNCTION_DECL) |
1597 | { | |
1598 | /* Might be a constexpr function pointer. */ | |
f83e6885 | 1599 | fun = cxx_eval_constant_expression (ctx, fun, |
1227ba74 | 1600 | /*lval*/false, non_constant_p, |
b2a43197 | 1601 | overflow_p); |
09b42213 | 1602 | STRIP_NOPS (fun); |
1603 | if (TREE_CODE (fun) == ADDR_EXPR) | |
1604 | fun = TREE_OPERAND (fun, 0); | |
9a97d94a | 1605 | /* For TARGET_VTABLE_USES_DESCRIPTORS targets, there is no |
1606 | indirection, the called expression is a pointer into the | |
1607 | virtual table which should contain FDESC_EXPR. Extract the | |
1608 | FUNCTION_DECL from there. */ | |
1609 | else if (TARGET_VTABLE_USES_DESCRIPTORS | |
1610 | && TREE_CODE (fun) == POINTER_PLUS_EXPR | |
1611 | && TREE_CODE (TREE_OPERAND (fun, 0)) == ADDR_EXPR | |
1612 | && TREE_CODE (TREE_OPERAND (fun, 1)) == INTEGER_CST) | |
1613 | { | |
1614 | tree d = TREE_OPERAND (TREE_OPERAND (fun, 0), 0); | |
1615 | if (VAR_P (d) | |
1616 | && DECL_VTABLE_OR_VTT_P (d) | |
1617 | && TREE_CODE (TREE_TYPE (d)) == ARRAY_TYPE | |
1618 | && TREE_TYPE (TREE_TYPE (d)) == vtable_entry_type | |
1619 | && DECL_INITIAL (d) | |
1620 | && TREE_CODE (DECL_INITIAL (d)) == CONSTRUCTOR) | |
1621 | { | |
1622 | tree i = int_const_binop (TRUNC_DIV_EXPR, TREE_OPERAND (fun, 1), | |
1623 | TYPE_SIZE_UNIT (vtable_entry_type)); | |
1624 | HOST_WIDE_INT idx = find_array_ctor_elt (DECL_INITIAL (d), i); | |
1625 | if (idx >= 0) | |
1626 | { | |
1627 | tree fdesc | |
1628 | = (*CONSTRUCTOR_ELTS (DECL_INITIAL (d)))[idx].value; | |
1629 | if (TREE_CODE (fdesc) == FDESC_EXPR | |
1630 | && integer_zerop (TREE_OPERAND (fdesc, 1))) | |
1631 | fun = TREE_OPERAND (fdesc, 0); | |
1632 | } | |
1633 | } | |
1634 | } | |
09b42213 | 1635 | } |
1636 | if (TREE_CODE (fun) != FUNCTION_DECL) | |
1637 | { | |
f83e6885 | 1638 | if (!ctx->quiet && !*non_constant_p) |
5967b28b | 1639 | error_at (loc, "expression %qE does not designate a %<constexpr%> " |
09b42213 | 1640 | "function", fun); |
1641 | *non_constant_p = true; | |
1642 | return t; | |
1643 | } | |
1644 | if (DECL_CLONED_FUNCTION_P (fun)) | |
1645 | fun = DECL_CLONED_FUNCTION (fun); | |
6b71bdb4 | 1646 | |
1647 | if (is_ubsan_builtin_p (fun)) | |
1648 | return void_node; | |
1649 | ||
a0e9bfbb | 1650 | if (fndecl_built_in_p (fun)) |
f1c6af10 | 1651 | return cxx_eval_builtin_function_call (ctx, t, fun, |
1227ba74 | 1652 | lval, non_constant_p, overflow_p); |
09b42213 | 1653 | if (!DECL_DECLARED_CONSTEXPR_P (fun)) |
1654 | { | |
f83e6885 | 1655 | if (!ctx->quiet) |
09b42213 | 1656 | { |
1dcd84cf | 1657 | if (!lambda_static_thunk_p (fun)) |
5967b28b | 1658 | error_at (loc, "call to non-%<constexpr%> function %qD", fun); |
09b42213 | 1659 | explain_invalid_constexpr_fn (fun); |
1660 | } | |
1661 | *non_constant_p = true; | |
1662 | return t; | |
1663 | } | |
1664 | ||
9ebe2ea3 | 1665 | constexpr_ctx new_ctx = *ctx; |
1666 | if (DECL_CONSTRUCTOR_P (fun) && !ctx->object | |
1667 | && TREE_CODE (t) == AGGR_INIT_EXPR) | |
1668 | { | |
1669 | /* We want to have an initialization target for an AGGR_INIT_EXPR. | |
1670 | If we don't already have one in CTX, use the AGGR_INIT_EXPR_SLOT. */ | |
1671 | new_ctx.object = AGGR_INIT_EXPR_SLOT (t); | |
1672 | tree ctor = new_ctx.ctor = build_constructor (DECL_CONTEXT (fun), NULL); | |
165d0d5b | 1673 | CONSTRUCTOR_NO_CLEARING (ctor) = true; |
9ebe2ea3 | 1674 | ctx->values->put (new_ctx.object, ctor); |
1675 | ctx = &new_ctx; | |
1676 | } | |
1677 | ||
09b42213 | 1678 | /* Shortcut trivial constructor/op=. */ |
1679 | if (trivial_fn_p (fun)) | |
1680 | { | |
9ebe2ea3 | 1681 | tree init = NULL_TREE; |
09b42213 | 1682 | if (call_expr_nargs (t) == 2) |
9ebe2ea3 | 1683 | init = convert_from_reference (get_nth_callarg (t, 1)); |
09b42213 | 1684 | else if (TREE_CODE (t) == AGGR_INIT_EXPR |
1685 | && AGGR_INIT_ZERO_FIRST (t)) | |
9ebe2ea3 | 1686 | init = build_zero_init (DECL_CONTEXT (fun), NULL_TREE, false); |
1687 | if (init) | |
1688 | { | |
1689 | tree op = get_nth_callarg (t, 0); | |
1690 | if (is_dummy_object (op)) | |
1691 | op = ctx->object; | |
1692 | else | |
1693 | op = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (op)), op); | |
1694 | tree set = build2 (MODIFY_EXPR, TREE_TYPE (op), op, init); | |
0ce12360 | 1695 | new_ctx.call = &new_call; |
1696 | return cxx_eval_constant_expression (&new_ctx, set, lval, | |
9ebe2ea3 | 1697 | non_constant_p, overflow_p); |
1698 | } | |
09b42213 | 1699 | } |
1700 | ||
8afcf831 | 1701 | /* We can't defer instantiating the function any longer. */ |
1702 | if (!DECL_INITIAL (fun) | |
1703 | && DECL_TEMPLOID_INSTANTIATION (fun)) | |
1704 | { | |
31db86df | 1705 | location_t save_loc = input_location; |
1706 | input_location = loc; | |
8afcf831 | 1707 | ++function_depth; |
1708 | instantiate_decl (fun, /*defer_ok*/false, /*expl_inst*/false); | |
1709 | --function_depth; | |
31db86df | 1710 | input_location = save_loc; |
8afcf831 | 1711 | } |
1712 | ||
09b42213 | 1713 | /* If in direct recursive call, optimize definition search. */ |
0ce12360 | 1714 | if (ctx && ctx->call && ctx->call->fundef && ctx->call->fundef->decl == fun) |
cf72f34d | 1715 | new_call.fundef = ctx->call->fundef; |
09b42213 | 1716 | else |
1717 | { | |
1718 | new_call.fundef = retrieve_constexpr_fundef (fun); | |
d2a9b1c1 | 1719 | if (new_call.fundef == NULL || new_call.fundef->body == NULL |
1720 | || fun == current_function_decl) | |
09b42213 | 1721 | { |
f83e6885 | 1722 | if (!ctx->quiet) |
09b42213 | 1723 | { |
d2a9b1c1 | 1724 | /* We need to check for current_function_decl here in case we're |
1725 | being called during cp_fold_function, because at that point | |
1726 | DECL_INITIAL is set properly and we have a fundef but we | |
1727 | haven't lowered invisirefs yet (c++/70344). */ | |
1728 | if (DECL_INITIAL (fun) == error_mark_node | |
1729 | || fun == current_function_decl) | |
a0efa758 | 1730 | error_at (loc, "%qD called in a constant expression before its " |
1731 | "definition is complete", fun); | |
1732 | else if (DECL_INITIAL (fun)) | |
09b42213 | 1733 | { |
33603066 | 1734 | /* The definition of fun was somehow unsuitable. But pretend |
1735 | that lambda static thunks don't exist. */ | |
1736 | if (!lambda_static_thunk_p (fun)) | |
1737 | error_at (loc, "%qD called in a constant expression", fun); | |
09b42213 | 1738 | explain_invalid_constexpr_fn (fun); |
1739 | } | |
1740 | else | |
1741 | error_at (loc, "%qD used before its definition", fun); | |
1742 | } | |
1743 | *non_constant_p = true; | |
1744 | return t; | |
1745 | } | |
1746 | } | |
9c96033c | 1747 | |
c8f6aeb1 | 1748 | bool non_constant_args = false; |
cf72f34d | 1749 | cxx_bind_parameters_in_call (ctx, t, &new_call, |
c8f6aeb1 | 1750 | non_constant_p, overflow_p, &non_constant_args); |
8a9112cd | 1751 | |
1752 | /* We build up the bindings list before we know whether we already have this | |
1753 | call cached. If we don't end up saving these bindings, ggc_free them when | |
1754 | this function exits. */ | |
1755 | struct free_bindings | |
1756 | { | |
1757 | tree &bindings; | |
1758 | bool do_free; | |
1759 | free_bindings (tree &b): bindings (b), do_free(true) { } | |
1760 | void preserve () { do_free = false; } | |
1761 | ~free_bindings () { | |
1762 | if (do_free) | |
714c2a31 | 1763 | { |
1764 | for (int i = 0; i < TREE_VEC_LENGTH (bindings); ++i) | |
1765 | free_constructor (TREE_VEC_ELT (bindings, i)); | |
1766 | ggc_free (bindings); | |
1767 | } | |
8a9112cd | 1768 | } |
1769 | } fb (new_call.bindings); | |
1770 | ||
09b42213 | 1771 | if (*non_constant_p) |
1772 | return t; | |
1773 | ||
1774 | depth_ok = push_cx_call_context (t); | |
1775 | ||
c8f6aeb1 | 1776 | tree result = NULL_TREE; |
09b42213 | 1777 | |
c8f6aeb1 | 1778 | constexpr_call *entry = NULL; |
167a09fb | 1779 | if (depth_ok && !non_constant_args && ctx->strict) |
09b42213 | 1780 | { |
919873c7 | 1781 | new_call.hash = constexpr_fundef_hasher::hash (new_call.fundef); |
1782 | new_call.hash | |
1783 | = iterative_hash_template_arg (new_call.bindings, new_call.hash); | |
1784 | new_call.hash | |
1562c831 | 1785 | = iterative_hash_object (ctx->manifestly_const_eval, new_call.hash); |
c8f6aeb1 | 1786 | |
1787 | /* If we have seen this call before, we are done. */ | |
1788 | maybe_initialize_constexpr_call_table (); | |
1789 | constexpr_call **slot | |
1790 | = constexpr_call_table->find_slot (&new_call, INSERT); | |
1791 | entry = *slot; | |
1792 | if (entry == NULL) | |
1793 | { | |
1794 | /* We need to keep a pointer to the entry, not just the slot, as the | |
1795 | slot can move in the call to cxx_eval_builtin_function_call. */ | |
1796 | *slot = entry = ggc_alloc<constexpr_call> (); | |
1797 | *entry = new_call; | |
8a9112cd | 1798 | fb.preserve (); |
c8f6aeb1 | 1799 | } |
2ba934c7 | 1800 | /* Calls that are in progress have their result set to NULL, |
c8f6aeb1 | 1801 | so that we can detect circular dependencies. */ |
1802 | else if (entry->result == NULL) | |
1803 | { | |
1804 | if (!ctx->quiet) | |
1805 | error ("call has circular dependency"); | |
1806 | *non_constant_p = true; | |
1807 | entry->result = result = error_mark_node; | |
1808 | } | |
1809 | else | |
1810 | result = entry->result; | |
09b42213 | 1811 | } |
1812 | ||
1813 | if (!depth_ok) | |
1814 | { | |
f83e6885 | 1815 | if (!ctx->quiet) |
5967b28b | 1816 | error ("%<constexpr%> evaluation depth exceeds maximum of %d (use " |
f91d3a9d | 1817 | "%<-fconstexpr-depth=%> to increase the maximum)", |
09b42213 | 1818 | max_constexpr_depth); |
1819 | *non_constant_p = true; | |
c8f6aeb1 | 1820 | result = error_mark_node; |
09b42213 | 1821 | } |
1822 | else | |
1823 | { | |
ab099088 | 1824 | if (result && result != error_mark_node) |
1825 | /* OK */; | |
1826 | else if (!DECL_SAVED_TREE (fun)) | |
1827 | { | |
1828 | /* When at_eof >= 2, cgraph has started throwing away | |
1829 | DECL_SAVED_TREE, so fail quietly. FIXME we get here because of | |
1830 | late code generation for VEC_INIT_EXPR, which needs to be | |
1831 | completely reconsidered. */ | |
1832 | gcc_assert (at_eof >= 2 && ctx->quiet); | |
1833 | *non_constant_p = true; | |
1834 | } | |
1835 | else | |
cf72f34d | 1836 | { |
4f7ebe46 | 1837 | tree body, parms, res; |
714c2a31 | 1838 | releasing_vec ctors; |
88a59139 | 1839 | |
4f7ebe46 | 1840 | /* Reuse or create a new unshared copy of this function's body. */ |
02d7a132 | 1841 | tree copy = get_fundef_copy (new_call.fundef); |
a050099a | 1842 | body = TREE_PURPOSE (copy); |
1843 | parms = TREE_VALUE (copy); | |
1844 | res = TREE_TYPE (copy); | |
88a59139 | 1845 | |
1846 | /* Associate the bindings with the remapped parms. */ | |
1847 | tree bound = new_call.bindings; | |
1848 | tree remapped = parms; | |
7a429a9d | 1849 | for (int i = 0; i < TREE_VEC_LENGTH (bound); ++i) |
9c96033c | 1850 | { |
7a429a9d | 1851 | tree arg = TREE_VEC_ELT (bound, i); |
5898f0d7 | 1852 | /* Don't share a CONSTRUCTOR that might be changed. */ |
e283bb4f | 1853 | arg = unshare_constructor (arg); |
714c2a31 | 1854 | if (TREE_CODE (arg) == CONSTRUCTOR) |
1855 | vec_safe_push (ctors, arg); | |
88a59139 | 1856 | ctx->values->put (remapped, arg); |
88a59139 | 1857 | remapped = DECL_CHAIN (remapped); |
9c96033c | 1858 | } |
88a59139 | 1859 | /* Add the RESULT_DECL to the values map, too. */ |
1860 | tree slot = NULL_TREE; | |
1861 | if (DECL_BY_REFERENCE (res)) | |
9c96033c | 1862 | { |
88a59139 | 1863 | slot = AGGR_INIT_EXPR_SLOT (t); |
1864 | tree addr = build_address (slot); | |
1865 | addr = build_nop (TREE_TYPE (res), addr); | |
1866 | ctx->values->put (res, addr); | |
1867 | ctx->values->put (slot, NULL_TREE); | |
1868 | } | |
1869 | else | |
1870 | ctx->values->put (res, NULL_TREE); | |
9c96033c | 1871 | |
4f7ebe46 | 1872 | /* Track the callee's evaluated SAVE_EXPRs so that we can forget |
1873 | their values after the call. */ | |
1874 | constexpr_ctx ctx_with_save_exprs = *ctx; | |
d0782a7e | 1875 | auto_vec<tree, 10> save_exprs; |
4f7ebe46 | 1876 | ctx_with_save_exprs.save_exprs = &save_exprs; |
43b7271d | 1877 | ctx_with_save_exprs.call = &new_call; |
4f7ebe46 | 1878 | |
88a59139 | 1879 | tree jump_target = NULL_TREE; |
4f7ebe46 | 1880 | cxx_eval_constant_expression (&ctx_with_save_exprs, body, |
88a59139 | 1881 | lval, non_constant_p, overflow_p, |
1882 | &jump_target); | |
9c96033c | 1883 | |
88a59139 | 1884 | if (DECL_CONSTRUCTOR_P (fun)) |
1885 | /* This can be null for a subobject constructor call, in | |
1886 | which case what we care about is the initialization | |
1887 | side-effects rather than the value. We could get at the | |
1888 | value by evaluating *this, but we don't bother; there's | |
1889 | no need to put such a call in the hash table. */ | |
1890 | result = lval ? ctx->object : ctx->ctor; | |
1891 | else if (VOID_TYPE_P (TREE_TYPE (res))) | |
1892 | result = void_node; | |
1893 | else | |
1894 | { | |
1895 | result = *ctx->values->get (slot ? slot : res); | |
1896 | if (result == NULL_TREE && !*non_constant_p) | |
9c96033c | 1897 | { |
88a59139 | 1898 | if (!ctx->quiet) |
5967b28b | 1899 | error ("%<constexpr%> call flows off the end " |
88a59139 | 1900 | "of the function"); |
1901 | *non_constant_p = true; | |
9c96033c | 1902 | } |
9c96033c | 1903 | } |
88a59139 | 1904 | |
4f7ebe46 | 1905 | /* Forget the saved values of the callee's SAVE_EXPRs. */ |
d0782a7e | 1906 | unsigned int i; |
1907 | tree save_expr; | |
1908 | FOR_EACH_VEC_ELT (save_exprs, i, save_expr) | |
1909 | ctx_with_save_exprs.values->remove (save_expr); | |
4f7ebe46 | 1910 | |
88a59139 | 1911 | /* Remove the parms/result from the values map. Is it worth |
1912 | bothering to do this when the map itself is only live for | |
1913 | one constexpr evaluation? If so, maybe also clear out | |
1914 | other vars from call, maybe in BIND_EXPR handling? */ | |
1915 | ctx->values->remove (res); | |
1916 | if (slot) | |
1917 | ctx->values->remove (slot); | |
1918 | for (tree parm = parms; parm; parm = TREE_CHAIN (parm)) | |
1919 | ctx->values->remove (parm); | |
4f7ebe46 | 1920 | |
714c2a31 | 1921 | /* Free any parameter CONSTRUCTORs we aren't returning directly. */ |
1922 | while (!ctors->is_empty ()) | |
1923 | { | |
1924 | tree c = ctors->pop (); | |
1925 | if (c != result) | |
1926 | free_constructor (c); | |
1927 | } | |
1928 | ||
4f7ebe46 | 1929 | /* Make the unshared function copy we used available for re-use. */ |
1930 | save_fundef_copy (fun, copy); | |
cf72f34d | 1931 | } |
9c96033c | 1932 | |
09b42213 | 1933 | if (result == error_mark_node) |
1934 | *non_constant_p = true; | |
c3f376bf | 1935 | if (*non_constant_p || *overflow_p) |
c8f6aeb1 | 1936 | result = error_mark_node; |
88a59139 | 1937 | else if (!result) |
9c96033c | 1938 | result = void_node; |
c8f6aeb1 | 1939 | if (entry) |
1940 | entry->result = result; | |
09b42213 | 1941 | } |
1942 | ||
c6d97004 | 1943 | /* The result of a constexpr function must be completely initialized. */ |
1944 | if (TREE_CODE (result) == CONSTRUCTOR) | |
79cdb4f5 | 1945 | clear_no_implicit_zero (result); |
c6d97004 | 1946 | |
09b42213 | 1947 | pop_cx_call_context (); |
e25c1ab4 | 1948 | return result; |
09b42213 | 1949 | } |
1950 | ||
1951 | /* FIXME speed this up, it's taking 16% of compile time on sieve testcase. */ | |
1952 | ||
1953 | bool | |
1954 | reduced_constant_expression_p (tree t) | |
1955 | { | |
a34934c2 | 1956 | if (t == NULL_TREE) |
1957 | return false; | |
1958 | ||
09b42213 | 1959 | switch (TREE_CODE (t)) |
1960 | { | |
1961 | case PTRMEM_CST: | |
1962 | /* Even if we can't lower this yet, it's constant. */ | |
1963 | return true; | |
1964 | ||
1965 | case CONSTRUCTOR: | |
1966 | /* And we need to handle PTRMEM_CST wrapped in a CONSTRUCTOR. */ | |
56da7fe6 | 1967 | tree idx, val, field; unsigned HOST_WIDE_INT i; |
165d0d5b | 1968 | if (CONSTRUCTOR_NO_CLEARING (t)) |
c4210852 | 1969 | { |
1970 | if (TREE_CODE (TREE_TYPE (t)) == VECTOR_TYPE) | |
1971 | /* An initialized vector would have a VECTOR_CST. */ | |
1972 | return false; | |
1973 | else | |
1974 | field = next_initializable_field (TYPE_FIELDS (TREE_TYPE (t))); | |
1975 | } | |
56da7fe6 | 1976 | else |
1977 | field = NULL_TREE; | |
1978 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (t), i, idx, val) | |
ce4ffd9e | 1979 | { |
a34934c2 | 1980 | /* If VAL is null, we're in the middle of initializing this |
1981 | element. */ | |
56da7fe6 | 1982 | if (!reduced_constant_expression_p (val)) |
ce4ffd9e | 1983 | return false; |
56da7fe6 | 1984 | if (field) |
1985 | { | |
1986 | if (idx != field) | |
1987 | return false; | |
1988 | field = next_initializable_field (DECL_CHAIN (field)); | |
1989 | } | |
ce4ffd9e | 1990 | } |
56da7fe6 | 1991 | if (field) |
1992 | return false; | |
165d0d5b | 1993 | else if (CONSTRUCTOR_NO_CLEARING (t)) |
56da7fe6 | 1994 | /* All the fields are initialized. */ |
165d0d5b | 1995 | CONSTRUCTOR_NO_CLEARING (t) = false; |
09b42213 | 1996 | return true; |
1997 | ||
1998 | default: | |
1999 | /* FIXME are we calling this too much? */ | |
2000 | return initializer_constant_valid_p (t, TREE_TYPE (t)) != NULL_TREE; | |
2001 | } | |
2002 | } | |
2003 | ||
2004 | /* Some expressions may have constant operands but are not constant | |
941fafa5 | 2005 | themselves, such as 1/0. Call this function to check for that |
2006 | condition. | |
09b42213 | 2007 | |
2008 | We only call this in places that require an arithmetic constant, not in | |
2009 | places where we might have a non-constant expression that can be a | |
2010 | component of a constant expression, such as the address of a constexpr | |
2011 | variable that might be dereferenced later. */ | |
2012 | ||
2013 | static bool | |
2014 | verify_constant (tree t, bool allow_non_constant, bool *non_constant_p, | |
2015 | bool *overflow_p) | |
2016 | { | |
2017 | if (!*non_constant_p && !reduced_constant_expression_p (t)) | |
2018 | { | |
2019 | if (!allow_non_constant) | |
2020 | error ("%q+E is not a constant expression", t); | |
2021 | *non_constant_p = true; | |
2022 | } | |
2023 | if (TREE_OVERFLOW_P (t)) | |
2024 | { | |
2025 | if (!allow_non_constant) | |
2026 | { | |
2027 | permerror (input_location, "overflow in constant expression"); | |
2028 | /* If we're being permissive (and are in an enforcing | |
2029 | context), ignore the overflow. */ | |
2030 | if (flag_permissive) | |
2031 | return *non_constant_p; | |
2032 | } | |
2033 | *overflow_p = true; | |
2034 | } | |
2035 | return *non_constant_p; | |
2036 | } | |
2037 | ||
2b035ffe | 2038 | /* Check whether the shift operation with code CODE and type TYPE on LHS |
2039 | and RHS is undefined. If it is, give an error with an explanation, | |
2040 | and return true; return false otherwise. */ | |
2041 | ||
2042 | static bool | |
2043 | cxx_eval_check_shift_p (location_t loc, const constexpr_ctx *ctx, | |
2044 | enum tree_code code, tree type, tree lhs, tree rhs) | |
2045 | { | |
2046 | if ((code != LSHIFT_EXPR && code != RSHIFT_EXPR) | |
2047 | || TREE_CODE (lhs) != INTEGER_CST | |
2048 | || TREE_CODE (rhs) != INTEGER_CST) | |
2049 | return false; | |
2050 | ||
2051 | tree lhstype = TREE_TYPE (lhs); | |
2052 | unsigned HOST_WIDE_INT uprec = TYPE_PRECISION (TREE_TYPE (lhs)); | |
2053 | ||
2054 | /* [expr.shift] The behavior is undefined if the right operand | |
2055 | is negative, or greater than or equal to the length in bits | |
2056 | of the promoted left operand. */ | |
2057 | if (tree_int_cst_sgn (rhs) == -1) | |
2058 | { | |
2059 | if (!ctx->quiet) | |
91d87e22 | 2060 | permerror (loc, "right operand of shift expression %q+E is negative", |
2061 | build2_loc (loc, code, type, lhs, rhs)); | |
2062 | return (!flag_permissive || ctx->quiet); | |
2b035ffe | 2063 | } |
2064 | if (compare_tree_int (rhs, uprec) >= 0) | |
2065 | { | |
2066 | if (!ctx->quiet) | |
85b9be9b | 2067 | permerror (loc, "right operand of shift expression %q+E is greater " |
2068 | "than or equal to the precision %wu of the left operand", | |
2069 | build2_loc (loc, code, type, lhs, rhs), uprec); | |
91d87e22 | 2070 | return (!flag_permissive || ctx->quiet); |
2b035ffe | 2071 | } |
2072 | ||
2073 | /* The value of E1 << E2 is E1 left-shifted E2 bit positions; [...] | |
2074 | if E1 has a signed type and non-negative value, and E1x2^E2 is | |
2075 | representable in the corresponding unsigned type of the result type, | |
2076 | then that value, converted to the result type, is the resulting value; | |
1170ee75 | 2077 | otherwise, the behavior is undefined. |
2078 | For C++2a: | |
2079 | The value of E1 << E2 is the unique value congruent to E1 x 2^E2 modulo | |
2080 | 2^N, where N is the range exponent of the type of the result. */ | |
2081 | if (code == LSHIFT_EXPR | |
2082 | && !TYPE_UNSIGNED (lhstype) | |
2083 | && cxx_dialect >= cxx11 | |
2084 | && cxx_dialect < cxx2a) | |
2b035ffe | 2085 | { |
2086 | if (tree_int_cst_sgn (lhs) == -1) | |
2087 | { | |
2088 | if (!ctx->quiet) | |
91d87e22 | 2089 | permerror (loc, |
2090 | "left operand of shift expression %q+E is negative", | |
2091 | build2_loc (loc, code, type, lhs, rhs)); | |
2092 | return (!flag_permissive || ctx->quiet); | |
2b035ffe | 2093 | } |
2094 | /* For signed x << y the following: | |
2095 | (unsigned) x >> ((prec (lhs) - 1) - y) | |
2096 | if > 1, is undefined. The right-hand side of this formula | |
2097 | is the highest bit of the LHS that can be set (starting from 0), | |
2098 | so that the shift doesn't overflow. We then right-shift the LHS | |
2099 | to see whether any other bit is set making the original shift | |
2100 | undefined -- the result is not representable in the corresponding | |
2101 | unsigned type. */ | |
2102 | tree t = build_int_cst (unsigned_type_node, uprec - 1); | |
2103 | t = fold_build2 (MINUS_EXPR, unsigned_type_node, t, rhs); | |
2104 | tree ulhs = fold_convert (unsigned_type_for (lhstype), lhs); | |
2105 | t = fold_build2 (RSHIFT_EXPR, TREE_TYPE (ulhs), ulhs, t); | |
2106 | if (tree_int_cst_lt (integer_one_node, t)) | |
2107 | { | |
2108 | if (!ctx->quiet) | |
91d87e22 | 2109 | permerror (loc, "shift expression %q+E overflows", |
2110 | build2_loc (loc, code, type, lhs, rhs)); | |
2111 | return (!flag_permissive || ctx->quiet); | |
2b035ffe | 2112 | } |
2113 | } | |
2114 | return false; | |
2115 | } | |
2116 | ||
09b42213 | 2117 | /* Subroutine of cxx_eval_constant_expression. |
2118 | Attempt to reduce the unary expression tree T to a compile time value. | |
2119 | If successful, return the value. Otherwise issue a diagnostic | |
2120 | and return error_mark_node. */ | |
2121 | ||
2122 | static tree | |
cf72f34d | 2123 | cxx_eval_unary_expression (const constexpr_ctx *ctx, tree t, |
c8f6aeb1 | 2124 | bool /*lval*/, |
09b42213 | 2125 | bool *non_constant_p, bool *overflow_p) |
2126 | { | |
2127 | tree r; | |
2128 | tree orig_arg = TREE_OPERAND (t, 0); | |
c8f6aeb1 | 2129 | tree arg = cxx_eval_constant_expression (ctx, orig_arg, /*lval*/false, |
2130 | non_constant_p, overflow_p); | |
09b42213 | 2131 | VERIFY_CONSTANT (arg); |
93add516 | 2132 | location_t loc = EXPR_LOCATION (t); |
2133 | enum tree_code code = TREE_CODE (t); | |
2134 | tree type = TREE_TYPE (t); | |
2135 | r = fold_unary_loc (loc, code, type, arg); | |
2136 | if (r == NULL_TREE) | |
2137 | { | |
2138 | if (arg == orig_arg) | |
2139 | r = t; | |
2140 | else | |
2141 | r = build1_loc (loc, code, type, arg); | |
2142 | } | |
09b42213 | 2143 | VERIFY_CONSTANT (r); |
2144 | return r; | |
2145 | } | |
2146 | ||
46fad8d5 | 2147 | /* Helper function for cxx_eval_binary_expression. Try to optimize |
2148 | original POINTER_PLUS_EXPR T, LHS p+ RHS, return NULL_TREE if the | |
2149 | generic folding should be used. */ | |
2150 | ||
2151 | static tree | |
2152 | cxx_fold_pointer_plus_expression (const constexpr_ctx *ctx, tree t, | |
2153 | tree lhs, tree rhs, bool *non_constant_p, | |
2154 | bool *overflow_p) | |
2155 | { | |
2156 | STRIP_NOPS (lhs); | |
2157 | if (TREE_CODE (lhs) != ADDR_EXPR) | |
2158 | return NULL_TREE; | |
2159 | ||
2160 | lhs = TREE_OPERAND (lhs, 0); | |
2161 | ||
2162 | /* &A[i] p+ j => &A[i + j] */ | |
2163 | if (TREE_CODE (lhs) == ARRAY_REF | |
2164 | && TREE_CODE (TREE_OPERAND (lhs, 1)) == INTEGER_CST | |
2165 | && TREE_CODE (rhs) == INTEGER_CST | |
2166 | && TYPE_SIZE_UNIT (TREE_TYPE (lhs)) | |
2167 | && TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (lhs))) == INTEGER_CST) | |
2168 | { | |
2169 | tree orig_type = TREE_TYPE (t); | |
2170 | location_t loc = EXPR_LOCATION (t); | |
2171 | tree type = TREE_TYPE (lhs); | |
2172 | ||
2173 | t = fold_convert_loc (loc, ssizetype, TREE_OPERAND (lhs, 1)); | |
2174 | tree nelts = array_type_nelts_top (TREE_TYPE (TREE_OPERAND (lhs, 0))); | |
2175 | nelts = cxx_eval_constant_expression (ctx, nelts, false, non_constant_p, | |
2176 | overflow_p); | |
2177 | if (*non_constant_p) | |
2178 | return NULL_TREE; | |
2179 | /* Don't fold an out-of-bound access. */ | |
2180 | if (!tree_int_cst_le (t, nelts)) | |
2181 | return NULL_TREE; | |
2182 | rhs = cp_fold_convert (ssizetype, rhs); | |
2183 | /* Don't fold if rhs can't be divided exactly by TYPE_SIZE_UNIT. | |
2184 | constexpr int A[1]; ... (char *)&A[0] + 1 */ | |
2185 | if (!integer_zerop (fold_build2_loc (loc, TRUNC_MOD_EXPR, sizetype, | |
2186 | rhs, TYPE_SIZE_UNIT (type)))) | |
2187 | return NULL_TREE; | |
2188 | /* Make sure to treat the second operand of POINTER_PLUS_EXPR | |
2189 | as signed. */ | |
2190 | rhs = fold_build2_loc (loc, EXACT_DIV_EXPR, ssizetype, rhs, | |
2191 | TYPE_SIZE_UNIT (type)); | |
2192 | t = size_binop_loc (loc, PLUS_EXPR, rhs, t); | |
2193 | t = build4_loc (loc, ARRAY_REF, type, TREE_OPERAND (lhs, 0), | |
2194 | t, NULL_TREE, NULL_TREE); | |
2195 | t = cp_build_addr_expr (t, tf_warning_or_error); | |
2196 | t = cp_fold_convert (orig_type, t); | |
2197 | return cxx_eval_constant_expression (ctx, t, /*lval*/false, | |
2198 | non_constant_p, overflow_p); | |
2199 | } | |
2200 | ||
2201 | return NULL_TREE; | |
2202 | } | |
2203 | ||
09b42213 | 2204 | /* Subroutine of cxx_eval_constant_expression. |
2205 | Like cxx_eval_unary_expression, except for binary expressions. */ | |
2206 | ||
2207 | static tree | |
cf72f34d | 2208 | cxx_eval_binary_expression (const constexpr_ctx *ctx, tree t, |
c8f6aeb1 | 2209 | bool /*lval*/, |
09b42213 | 2210 | bool *non_constant_p, bool *overflow_p) |
2211 | { | |
f7ef5392 | 2212 | tree r = NULL_TREE; |
09b42213 | 2213 | tree orig_lhs = TREE_OPERAND (t, 0); |
2214 | tree orig_rhs = TREE_OPERAND (t, 1); | |
2215 | tree lhs, rhs; | |
c8f6aeb1 | 2216 | lhs = cxx_eval_constant_expression (ctx, orig_lhs, /*lval*/false, |
b2a43197 | 2217 | non_constant_p, overflow_p); |
6d6737d9 | 2218 | /* Don't VERIFY_CONSTANT here, it's unnecessary and will break pointer |
2219 | subtraction. */ | |
2220 | if (*non_constant_p) | |
2221 | return t; | |
c8f6aeb1 | 2222 | rhs = cxx_eval_constant_expression (ctx, orig_rhs, /*lval*/false, |
b2a43197 | 2223 | non_constant_p, overflow_p); |
6d6737d9 | 2224 | if (*non_constant_p) |
2225 | return t; | |
93add516 | 2226 | |
2227 | location_t loc = EXPR_LOCATION (t); | |
2228 | enum tree_code code = TREE_CODE (t); | |
2229 | tree type = TREE_TYPE (t); | |
f7ef5392 | 2230 | |
2231 | if (code == EQ_EXPR || code == NE_EXPR) | |
2232 | { | |
2233 | bool is_code_eq = (code == EQ_EXPR); | |
2234 | ||
2235 | if (TREE_CODE (lhs) == PTRMEM_CST | |
2236 | && TREE_CODE (rhs) == PTRMEM_CST) | |
e9f29fe5 | 2237 | { |
2238 | tree lmem = PTRMEM_CST_MEMBER (lhs); | |
2239 | tree rmem = PTRMEM_CST_MEMBER (rhs); | |
2240 | bool eq; | |
2241 | if (TREE_CODE (lmem) == TREE_CODE (rmem) | |
2242 | && TREE_CODE (lmem) == FIELD_DECL | |
2243 | && TREE_CODE (DECL_CONTEXT (lmem)) == UNION_TYPE | |
2244 | && same_type_p (DECL_CONTEXT (lmem), | |
2245 | DECL_CONTEXT (rmem))) | |
2246 | /* If both refer to (possibly different) members of the same union | |
2247 | (12.3), they compare equal. */ | |
2248 | eq = true; | |
2249 | else | |
2250 | eq = cp_tree_equal (lhs, rhs); | |
2251 | r = constant_boolean_node (eq == is_code_eq, type); | |
2252 | } | |
f7ef5392 | 2253 | else if ((TREE_CODE (lhs) == PTRMEM_CST |
2254 | || TREE_CODE (rhs) == PTRMEM_CST) | |
2255 | && (null_member_pointer_value_p (lhs) | |
2256 | || null_member_pointer_value_p (rhs))) | |
2257 | r = constant_boolean_node (!is_code_eq, type); | |
f31f4e9c | 2258 | else if (TREE_CODE (lhs) == PTRMEM_CST) |
2259 | lhs = cplus_expand_constant (lhs); | |
2260 | else if (TREE_CODE (rhs) == PTRMEM_CST) | |
2261 | rhs = cplus_expand_constant (rhs); | |
f7ef5392 | 2262 | } |
cb768824 | 2263 | if (code == POINTER_PLUS_EXPR && !*non_constant_p |
2264 | && integer_zerop (lhs) && !integer_zerop (rhs)) | |
2265 | { | |
2266 | if (!ctx->quiet) | |
2267 | error ("arithmetic involving a null pointer in %qE", lhs); | |
2b1749c4 | 2268 | *non_constant_p = true; |
cb768824 | 2269 | return t; |
2270 | } | |
46fad8d5 | 2271 | else if (code == POINTER_PLUS_EXPR) |
2272 | r = cxx_fold_pointer_plus_expression (ctx, t, lhs, rhs, non_constant_p, | |
2273 | overflow_p); | |
f7ef5392 | 2274 | |
2275 | if (r == NULL_TREE) | |
2276 | r = fold_binary_loc (loc, code, type, lhs, rhs); | |
2277 | ||
93add516 | 2278 | if (r == NULL_TREE) |
2279 | { | |
2280 | if (lhs == orig_lhs && rhs == orig_rhs) | |
2281 | r = t; | |
2282 | else | |
2283 | r = build2_loc (loc, code, type, lhs, rhs); | |
2284 | } | |
2b035ffe | 2285 | else if (cxx_eval_check_shift_p (loc, ctx, code, type, lhs, rhs)) |
2286 | *non_constant_p = true; | |
6d6737d9 | 2287 | /* Don't VERIFY_CONSTANT if this might be dealing with a pointer to |
2288 | a local array in a constexpr function. */ | |
d03fa520 | 2289 | bool ptr = INDIRECT_TYPE_P (TREE_TYPE (lhs)); |
35f2c28f | 2290 | if (!ptr) |
aae7465c | 2291 | VERIFY_CONSTANT (r); |
09b42213 | 2292 | return r; |
2293 | } | |
2294 | ||
2295 | /* Subroutine of cxx_eval_constant_expression. | |
2296 | Attempt to evaluate condition expressions. Dead branches are not | |
2297 | looked into. */ | |
2298 | ||
2299 | static tree | |
cf72f34d | 2300 | cxx_eval_conditional_expression (const constexpr_ctx *ctx, tree t, |
1227ba74 | 2301 | bool lval, |
00f21715 | 2302 | bool *non_constant_p, bool *overflow_p, |
2303 | tree *jump_target) | |
09b42213 | 2304 | { |
cf72f34d | 2305 | tree val = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), |
c8f6aeb1 | 2306 | /*lval*/false, |
b2a43197 | 2307 | non_constant_p, overflow_p); |
09b42213 | 2308 | VERIFY_CONSTANT (val); |
2309 | /* Don't VERIFY_CONSTANT the other operands. */ | |
2310 | if (integer_zerop (val)) | |
02d7a132 | 2311 | val = TREE_OPERAND (t, 2); |
2312 | else | |
2313 | val = TREE_OPERAND (t, 1); | |
2314 | if (TREE_CODE (t) == IF_STMT && !val) | |
2315 | val = void_node; | |
2316 | return cxx_eval_constant_expression (ctx, val, lval, non_constant_p, | |
2317 | overflow_p, jump_target); | |
09b42213 | 2318 | } |
2319 | ||
31595caf | 2320 | /* Subroutine of cxx_eval_constant_expression. |
2321 | Attempt to evaluate vector condition expressions. Unlike | |
2322 | cxx_eval_conditional_expression, VEC_COND_EXPR acts like a normal | |
2323 | ternary arithmetics operation, where all 3 arguments have to be | |
2324 | evaluated as constants and then folding computes the result from | |
2325 | them. */ | |
2326 | ||
2327 | static tree | |
2328 | cxx_eval_vector_conditional_expression (const constexpr_ctx *ctx, tree t, | |
2329 | bool *non_constant_p, bool *overflow_p) | |
2330 | { | |
2331 | tree arg1 = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), | |
2332 | /*lval*/false, | |
2333 | non_constant_p, overflow_p); | |
2334 | VERIFY_CONSTANT (arg1); | |
2335 | tree arg2 = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), | |
2336 | /*lval*/false, | |
2337 | non_constant_p, overflow_p); | |
2338 | VERIFY_CONSTANT (arg2); | |
2339 | tree arg3 = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 2), | |
2340 | /*lval*/false, | |
2341 | non_constant_p, overflow_p); | |
2342 | VERIFY_CONSTANT (arg3); | |
2343 | location_t loc = EXPR_LOCATION (t); | |
2344 | tree type = TREE_TYPE (t); | |
2345 | tree r = fold_ternary_loc (loc, VEC_COND_EXPR, type, arg1, arg2, arg3); | |
2346 | if (r == NULL_TREE) | |
2347 | { | |
2348 | if (arg1 == TREE_OPERAND (t, 0) | |
2349 | && arg2 == TREE_OPERAND (t, 1) | |
2350 | && arg3 == TREE_OPERAND (t, 2)) | |
2351 | r = t; | |
2352 | else | |
2353 | r = build3_loc (loc, VEC_COND_EXPR, type, arg1, arg2, arg3); | |
2354 | } | |
2355 | VERIFY_CONSTANT (r); | |
2356 | return r; | |
2357 | } | |
2358 | ||
7963b19d | 2359 | /* Returns less than, equal to, or greater than zero if KEY is found to be |
2360 | less than, to match, or to be greater than the constructor_elt's INDEX. */ | |
2361 | ||
2362 | static int | |
2363 | array_index_cmp (tree key, tree index) | |
2364 | { | |
2365 | gcc_assert (TREE_CODE (key) == INTEGER_CST); | |
2366 | ||
2367 | switch (TREE_CODE (index)) | |
2368 | { | |
2369 | case INTEGER_CST: | |
2370 | return tree_int_cst_compare (key, index); | |
2371 | case RANGE_EXPR: | |
2372 | { | |
2373 | tree lo = TREE_OPERAND (index, 0); | |
2374 | tree hi = TREE_OPERAND (index, 1); | |
2375 | if (tree_int_cst_lt (key, lo)) | |
2376 | return -1; | |
2377 | else if (tree_int_cst_lt (hi, key)) | |
2378 | return 1; | |
2379 | else | |
2380 | return 0; | |
2381 | } | |
2382 | default: | |
2383 | gcc_unreachable (); | |
2384 | } | |
2385 | } | |
2386 | ||
2387 | /* Returns the index of the constructor_elt of ARY which matches DINDEX, or -1 | |
2388 | if none. If INSERT is true, insert a matching element rather than fail. */ | |
2389 | ||
2390 | static HOST_WIDE_INT | |
9a97d94a | 2391 | find_array_ctor_elt (tree ary, tree dindex, bool insert) |
7963b19d | 2392 | { |
2393 | if (tree_int_cst_sgn (dindex) < 0) | |
2394 | return -1; | |
2395 | ||
2396 | unsigned HOST_WIDE_INT i = tree_to_uhwi (dindex); | |
2397 | vec<constructor_elt, va_gc> *elts = CONSTRUCTOR_ELTS (ary); | |
2398 | unsigned HOST_WIDE_INT len = vec_safe_length (elts); | |
2399 | ||
2400 | unsigned HOST_WIDE_INT end = len; | |
2401 | unsigned HOST_WIDE_INT begin = 0; | |
2402 | ||
2403 | /* If the last element of the CONSTRUCTOR has its own index, we can assume | |
2404 | that the same is true of the other elements and index directly. */ | |
2405 | if (end > 0) | |
2406 | { | |
e99466d6 | 2407 | tree cindex = (*elts)[end - 1].index; |
7963b19d | 2408 | if (TREE_CODE (cindex) == INTEGER_CST |
e99466d6 | 2409 | && compare_tree_int (cindex, end - 1) == 0) |
7963b19d | 2410 | { |
2411 | if (i < end) | |
2412 | return i; | |
2413 | else | |
2414 | begin = end; | |
2415 | } | |
2416 | } | |
2417 | ||
2418 | /* Otherwise, find a matching index by means of a binary search. */ | |
2419 | while (begin != end) | |
2420 | { | |
2421 | unsigned HOST_WIDE_INT middle = (begin + end) / 2; | |
f0b916c7 | 2422 | constructor_elt &elt = (*elts)[middle]; |
2423 | tree idx = elt.index; | |
7963b19d | 2424 | |
f0b916c7 | 2425 | int cmp = array_index_cmp (dindex, idx); |
7963b19d | 2426 | if (cmp < 0) |
2427 | end = middle; | |
2428 | else if (cmp > 0) | |
2429 | begin = middle + 1; | |
2430 | else | |
f0b916c7 | 2431 | { |
2432 | if (insert && TREE_CODE (idx) == RANGE_EXPR) | |
2433 | { | |
2434 | /* We need to split the range. */ | |
2435 | constructor_elt e; | |
2436 | tree lo = TREE_OPERAND (idx, 0); | |
2437 | tree hi = TREE_OPERAND (idx, 1); | |
e99466d6 | 2438 | tree value = elt.value; |
2439 | dindex = fold_convert (sizetype, dindex); | |
f0b916c7 | 2440 | if (tree_int_cst_lt (lo, dindex)) |
2441 | { | |
2442 | /* There are still some lower elts; shorten the range. */ | |
2443 | tree new_hi = int_const_binop (MINUS_EXPR, dindex, | |
2444 | size_one_node); | |
2445 | if (tree_int_cst_equal (lo, new_hi)) | |
2446 | /* Only one element left, no longer a range. */ | |
2447 | elt.index = lo; | |
2448 | else | |
2449 | TREE_OPERAND (idx, 1) = new_hi; | |
2450 | /* Append the element we want to insert. */ | |
2451 | ++middle; | |
2452 | e.index = dindex; | |
e99466d6 | 2453 | e.value = unshare_constructor (value); |
f0b916c7 | 2454 | vec_safe_insert (CONSTRUCTOR_ELTS (ary), middle, e); |
2455 | } | |
2456 | else | |
2457 | /* No lower elts, the range elt is now ours. */ | |
2458 | elt.index = dindex; | |
2459 | ||
2460 | if (tree_int_cst_lt (dindex, hi)) | |
2461 | { | |
2462 | /* There are still some higher elts; append a range. */ | |
2463 | tree new_lo = int_const_binop (PLUS_EXPR, dindex, | |
2464 | size_one_node); | |
2465 | if (tree_int_cst_equal (new_lo, hi)) | |
2466 | e.index = hi; | |
2467 | else | |
2468 | e.index = build2 (RANGE_EXPR, sizetype, new_lo, hi); | |
e99466d6 | 2469 | e.value = unshare_constructor (value); |
2470 | vec_safe_insert (CONSTRUCTOR_ELTS (ary), middle + 1, e); | |
f0b916c7 | 2471 | } |
2472 | } | |
2473 | return middle; | |
2474 | } | |
7963b19d | 2475 | } |
2476 | ||
2477 | if (insert) | |
2478 | { | |
2479 | constructor_elt e = { dindex, NULL_TREE }; | |
2480 | vec_safe_insert (CONSTRUCTOR_ELTS (ary), end, e); | |
2481 | return end; | |
2482 | } | |
2483 | ||
2484 | return -1; | |
2485 | } | |
2486 | ||
40df9099 | 2487 | /* Under the control of CTX, issue a detailed diagnostic for |
2488 | an out-of-bounds subscript INDEX into the expression ARRAY. */ | |
2489 | ||
2490 | static void | |
2491 | diag_array_subscript (const constexpr_ctx *ctx, tree array, tree index) | |
2492 | { | |
2493 | if (!ctx->quiet) | |
2494 | { | |
2495 | tree arraytype = TREE_TYPE (array); | |
2496 | ||
2497 | /* Convert the unsigned array subscript to a signed integer to avoid | |
2498 | printing huge numbers for small negative values. */ | |
2499 | tree sidx = fold_convert (ssizetype, index); | |
2500 | if (DECL_P (array)) | |
2501 | { | |
d7d265db | 2502 | if (TYPE_DOMAIN (arraytype)) |
2503 | error ("array subscript value %qE is outside the bounds " | |
2504 | "of array %qD of type %qT", sidx, array, arraytype); | |
2505 | else | |
62c34df8 | 2506 | error ("nonzero array subscript %qE is used with array %qD of " |
d7d265db | 2507 | "type %qT with unknown bounds", sidx, array, arraytype); |
40df9099 | 2508 | inform (DECL_SOURCE_LOCATION (array), "declared here"); |
2509 | } | |
d7d265db | 2510 | else if (TYPE_DOMAIN (arraytype)) |
40df9099 | 2511 | error ("array subscript value %qE is outside the bounds " |
2512 | "of array type %qT", sidx, arraytype); | |
d7d265db | 2513 | else |
62c34df8 | 2514 | error ("nonzero array subscript %qE is used with array of type %qT " |
d7d265db | 2515 | "with unknown bounds", sidx, arraytype); |
40df9099 | 2516 | } |
2517 | } | |
7963b19d | 2518 | |
51f0c7e2 | 2519 | /* Return the number of elements for TYPE (which is an ARRAY_TYPE or |
2520 | a VECTOR_TYPE). */ | |
2521 | ||
2522 | static tree | |
2523 | get_array_or_vector_nelts (const constexpr_ctx *ctx, tree type, | |
2524 | bool *non_constant_p, bool *overflow_p) | |
2525 | { | |
2526 | tree nelts; | |
2527 | if (TREE_CODE (type) == ARRAY_TYPE) | |
2528 | { | |
2529 | if (TYPE_DOMAIN (type)) | |
2530 | nelts = array_type_nelts_top (type); | |
2531 | else | |
2532 | nelts = size_zero_node; | |
2533 | } | |
2534 | else if (VECTOR_TYPE_P (type)) | |
2535 | nelts = size_int (TYPE_VECTOR_SUBPARTS (type)); | |
2536 | else | |
2537 | gcc_unreachable (); | |
2538 | ||
2539 | /* For VLAs, the number of elements won't be an integer constant. */ | |
2540 | nelts = cxx_eval_constant_expression (ctx, nelts, false, | |
2541 | non_constant_p, overflow_p); | |
2542 | return nelts; | |
2543 | } | |
2544 | ||
92fe8840 | 2545 | /* Extract element INDEX consisting of CHARS_PER_ELT chars from |
2546 | STRING_CST STRING. */ | |
2547 | ||
2548 | static tree | |
2549 | extract_string_elt (tree string, unsigned chars_per_elt, unsigned index) | |
2550 | { | |
2551 | tree type = cv_unqualified (TREE_TYPE (TREE_TYPE (string))); | |
2552 | tree r; | |
2553 | ||
2554 | if (chars_per_elt == 1) | |
2555 | r = build_int_cst (type, TREE_STRING_POINTER (string)[index]); | |
2556 | else | |
2557 | { | |
2558 | const unsigned char *ptr | |
2559 | = ((const unsigned char *)TREE_STRING_POINTER (string) | |
2560 | + index * chars_per_elt); | |
2561 | r = native_interpret_expr (type, ptr, chars_per_elt); | |
2562 | } | |
2563 | return r; | |
2564 | } | |
2565 | ||
09b42213 | 2566 | /* Subroutine of cxx_eval_constant_expression. |
2567 | Attempt to reduce a reference to an array slot. */ | |
2568 | ||
2569 | static tree | |
cf72f34d | 2570 | cxx_eval_array_reference (const constexpr_ctx *ctx, tree t, |
1227ba74 | 2571 | bool lval, |
09b42213 | 2572 | bool *non_constant_p, bool *overflow_p) |
2573 | { | |
2574 | tree oldary = TREE_OPERAND (t, 0); | |
cf72f34d | 2575 | tree ary = cxx_eval_constant_expression (ctx, oldary, |
1227ba74 | 2576 | lval, |
b2a43197 | 2577 | non_constant_p, overflow_p); |
09b42213 | 2578 | tree index, oldidx; |
cf3cefc9 | 2579 | HOST_WIDE_INT i = 0; |
2580 | tree elem_type = NULL_TREE; | |
2581 | unsigned len = 0, elem_nchars = 1; | |
09b42213 | 2582 | if (*non_constant_p) |
2583 | return t; | |
2584 | oldidx = TREE_OPERAND (t, 1); | |
cf72f34d | 2585 | index = cxx_eval_constant_expression (ctx, oldidx, |
f83e6885 | 2586 | false, |
b2a43197 | 2587 | non_constant_p, overflow_p); |
09b42213 | 2588 | VERIFY_CONSTANT (index); |
cf3cefc9 | 2589 | if (!lval) |
09b42213 | 2590 | { |
cf3cefc9 | 2591 | elem_type = TREE_TYPE (TREE_TYPE (ary)); |
2592 | if (TREE_CODE (ary) == VIEW_CONVERT_EXPR | |
2593 | && VECTOR_TYPE_P (TREE_TYPE (TREE_OPERAND (ary, 0))) | |
2594 | && TREE_TYPE (t) == TREE_TYPE (TREE_TYPE (TREE_OPERAND (ary, 0)))) | |
2595 | ary = TREE_OPERAND (ary, 0); | |
2596 | if (TREE_CODE (ary) == CONSTRUCTOR) | |
2597 | len = CONSTRUCTOR_NELTS (ary); | |
2598 | else if (TREE_CODE (ary) == STRING_CST) | |
2599 | { | |
2600 | elem_nchars = (TYPE_PRECISION (elem_type) | |
2601 | / TYPE_PRECISION (char_type_node)); | |
2602 | len = (unsigned) TREE_STRING_LENGTH (ary) / elem_nchars; | |
2603 | } | |
2604 | else if (TREE_CODE (ary) == VECTOR_CST) | |
f08ee65f | 2605 | /* We don't create variable-length VECTOR_CSTs. */ |
2606 | len = VECTOR_CST_NELTS (ary).to_constant (); | |
cf3cefc9 | 2607 | else |
2608 | { | |
2609 | /* We can't do anything with other tree codes, so use | |
2610 | VERIFY_CONSTANT to complain and fail. */ | |
2611 | VERIFY_CONSTANT (ary); | |
2612 | gcc_unreachable (); | |
2613 | } | |
aed8dc7f | 2614 | |
cf3cefc9 | 2615 | if (!tree_fits_shwi_p (index) |
2616 | || (i = tree_to_shwi (index)) < 0) | |
2617 | { | |
2618 | diag_array_subscript (ctx, ary, index); | |
2619 | *non_constant_p = true; | |
2620 | return t; | |
2621 | } | |
7963b19d | 2622 | } |
2623 | ||
51f0c7e2 | 2624 | tree nelts = get_array_or_vector_nelts (ctx, TREE_TYPE (ary), non_constant_p, |
2625 | overflow_p); | |
ce6a6978 | 2626 | VERIFY_CONSTANT (nelts); |
0acc6340 | 2627 | if ((lval |
2628 | ? !tree_int_cst_le (index, nelts) | |
2629 | : !tree_int_cst_lt (index, nelts)) | |
2630 | || tree_int_cst_sgn (index) < 0) | |
ce6a6978 | 2631 | { |
40df9099 | 2632 | diag_array_subscript (ctx, ary, index); |
ce6a6978 | 2633 | *non_constant_p = true; |
2634 | return t; | |
2635 | } | |
2636 | ||
cf3cefc9 | 2637 | if (lval && ary == oldary && index == oldidx) |
2638 | return t; | |
2639 | else if (lval) | |
2640 | return build4 (ARRAY_REF, TREE_TYPE (t), ary, index, NULL, NULL); | |
2641 | ||
7963b19d | 2642 | bool found; |
2643 | if (TREE_CODE (ary) == CONSTRUCTOR) | |
2644 | { | |
2645 | HOST_WIDE_INT ix = find_array_ctor_elt (ary, index); | |
2646 | found = (ix >= 0); | |
2647 | if (found) | |
2648 | i = ix; | |
aed8dc7f | 2649 | } |
7963b19d | 2650 | else |
2651 | found = (i < len); | |
aed8dc7f | 2652 | |
14869f28 | 2653 | if (found) |
2654 | { | |
2655 | tree r; | |
2656 | if (TREE_CODE (ary) == CONSTRUCTOR) | |
2657 | r = (*CONSTRUCTOR_ELTS (ary))[i].value; | |
2658 | else if (TREE_CODE (ary) == VECTOR_CST) | |
2659 | r = VECTOR_CST_ELT (ary, i); | |
14869f28 | 2660 | else |
92fe8840 | 2661 | r = extract_string_elt (ary, elem_nchars, i); |
2662 | ||
14869f28 | 2663 | if (r) |
2664 | /* Don't VERIFY_CONSTANT here. */ | |
2665 | return r; | |
09b42213 | 2666 | |
14869f28 | 2667 | /* Otherwise the element doesn't have a value yet. */ |
09b42213 | 2668 | } |
aed8dc7f | 2669 | |
14869f28 | 2670 | /* Not found. */ |
2671 | ||
2672 | if (TREE_CODE (ary) == CONSTRUCTOR | |
165d0d5b | 2673 | && CONSTRUCTOR_NO_CLEARING (ary)) |
09b42213 | 2674 | { |
14869f28 | 2675 | /* 'ary' is part of the aggregate initializer we're currently |
2676 | building; if there's no initializer for this element yet, | |
2677 | that's an error. */ | |
2678 | if (!ctx->quiet) | |
2679 | error ("accessing uninitialized array element"); | |
2680 | *non_constant_p = true; | |
2681 | return t; | |
09b42213 | 2682 | } |
14869f28 | 2683 | |
2684 | /* If it's within the array bounds but doesn't have an explicit | |
2685 | initializer, it's value-initialized. */ | |
2686 | tree val = build_value_init (elem_type, tf_warning_or_error); | |
2687 | return cxx_eval_constant_expression (ctx, val, lval, non_constant_p, | |
2688 | overflow_p); | |
09b42213 | 2689 | } |
2690 | ||
2691 | /* Subroutine of cxx_eval_constant_expression. | |
2692 | Attempt to reduce a field access of a value of class type. */ | |
2693 | ||
2694 | static tree | |
cf72f34d | 2695 | cxx_eval_component_reference (const constexpr_ctx *ctx, tree t, |
1227ba74 | 2696 | bool lval, |
09b42213 | 2697 | bool *non_constant_p, bool *overflow_p) |
2698 | { | |
2699 | unsigned HOST_WIDE_INT i; | |
2700 | tree field; | |
2701 | tree value; | |
2702 | tree part = TREE_OPERAND (t, 1); | |
2703 | tree orig_whole = TREE_OPERAND (t, 0); | |
cf72f34d | 2704 | tree whole = cxx_eval_constant_expression (ctx, orig_whole, |
1227ba74 | 2705 | lval, |
b2a43197 | 2706 | non_constant_p, overflow_p); |
7ab20d7c | 2707 | if (INDIRECT_REF_P (whole) |
2b1749c4 | 2708 | && integer_zerop (TREE_OPERAND (whole, 0))) |
2709 | { | |
2710 | if (!ctx->quiet) | |
2711 | error ("dereferencing a null pointer in %qE", orig_whole); | |
2712 | *non_constant_p = true; | |
2713 | return t; | |
2714 | } | |
cb768824 | 2715 | |
f16ed232 | 2716 | if (TREE_CODE (whole) == PTRMEM_CST) |
2717 | whole = cplus_expand_constant (whole); | |
09b42213 | 2718 | if (whole == orig_whole) |
2719 | return t; | |
1227ba74 | 2720 | if (lval) |
09b42213 | 2721 | return fold_build3 (COMPONENT_REF, TREE_TYPE (t), |
2722 | whole, part, NULL_TREE); | |
2723 | /* Don't VERIFY_CONSTANT here; we only want to check that we got a | |
2724 | CONSTRUCTOR. */ | |
2725 | if (!*non_constant_p && TREE_CODE (whole) != CONSTRUCTOR) | |
2726 | { | |
f83e6885 | 2727 | if (!ctx->quiet) |
09b42213 | 2728 | error ("%qE is not a constant expression", orig_whole); |
2729 | *non_constant_p = true; | |
2730 | } | |
2731 | if (DECL_MUTABLE_P (part)) | |
2732 | { | |
f83e6885 | 2733 | if (!ctx->quiet) |
09b42213 | 2734 | error ("mutable %qD is not usable in a constant expression", part); |
2735 | *non_constant_p = true; | |
2736 | } | |
2737 | if (*non_constant_p) | |
2738 | return t; | |
a4360e57 | 2739 | bool pmf = TYPE_PTRMEMFUNC_P (TREE_TYPE (whole)); |
09b42213 | 2740 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (whole), i, field, value) |
2741 | { | |
a4360e57 | 2742 | /* Use name match for PMF fields, as a variant will have a |
2743 | different FIELD_DECL with a different type. */ | |
2744 | if (pmf ? DECL_NAME (field) == DECL_NAME (part) | |
2745 | : field == part) | |
9c96033c | 2746 | { |
2747 | if (value) | |
2748 | return value; | |
2749 | else | |
2750 | /* We're in the middle of initializing it. */ | |
2751 | break; | |
2752 | } | |
09b42213 | 2753 | } |
2754 | if (TREE_CODE (TREE_TYPE (whole)) == UNION_TYPE | |
2755 | && CONSTRUCTOR_NELTS (whole) > 0) | |
2756 | { | |
2757 | /* DR 1188 says we don't have to deal with this. */ | |
f83e6885 | 2758 | if (!ctx->quiet) |
09b42213 | 2759 | error ("accessing %qD member instead of initialized %qD member in " |
2760 | "constant expression", part, CONSTRUCTOR_ELT (whole, 0)->index); | |
2761 | *non_constant_p = true; | |
2762 | return t; | |
2763 | } | |
2764 | ||
f894a056 | 2765 | /* We only create a CONSTRUCTOR for a subobject when we modify it, so empty |
2766 | classes never get represented; throw together a value now. */ | |
cd5a9ed1 | 2767 | if (is_really_empty_class (TREE_TYPE (t), /*ignore_vptr*/false)) |
f894a056 | 2768 | return build_constructor (TREE_TYPE (t), NULL); |
2769 | ||
a4360e57 | 2770 | gcc_assert (DECL_CONTEXT (part) == TYPE_MAIN_VARIANT (TREE_TYPE (whole))); |
2771 | ||
165d0d5b | 2772 | if (CONSTRUCTOR_NO_CLEARING (whole)) |
cf72f34d | 2773 | { |
2774 | /* 'whole' is part of the aggregate initializer we're currently | |
2775 | building; if there's no initializer for this member yet, that's an | |
f894a056 | 2776 | error. */ |
f83e6885 | 2777 | if (!ctx->quiet) |
cf72f34d | 2778 | error ("accessing uninitialized member %qD", part); |
2779 | *non_constant_p = true; | |
2780 | return t; | |
2781 | } | |
2782 | ||
09b42213 | 2783 | /* If there's no explicit init for this field, it's value-initialized. */ |
2784 | value = build_value_init (TREE_TYPE (t), tf_warning_or_error); | |
cf72f34d | 2785 | return cxx_eval_constant_expression (ctx, value, |
1227ba74 | 2786 | lval, |
b2a43197 | 2787 | non_constant_p, overflow_p); |
09b42213 | 2788 | } |
2789 | ||
2790 | /* Subroutine of cxx_eval_constant_expression. | |
2791 | Attempt to reduce a field access of a value of class type that is | |
2792 | expressed as a BIT_FIELD_REF. */ | |
2793 | ||
2794 | static tree | |
cf72f34d | 2795 | cxx_eval_bit_field_ref (const constexpr_ctx *ctx, tree t, |
1227ba74 | 2796 | bool lval, |
09b42213 | 2797 | bool *non_constant_p, bool *overflow_p) |
2798 | { | |
2799 | tree orig_whole = TREE_OPERAND (t, 0); | |
2800 | tree retval, fldval, utype, mask; | |
2801 | bool fld_seen = false; | |
2802 | HOST_WIDE_INT istart, isize; | |
cf72f34d | 2803 | tree whole = cxx_eval_constant_expression (ctx, orig_whole, |
1227ba74 | 2804 | lval, |
b2a43197 | 2805 | non_constant_p, overflow_p); |
09b42213 | 2806 | tree start, field, value; |
2807 | unsigned HOST_WIDE_INT i; | |
2808 | ||
2809 | if (whole == orig_whole) | |
2810 | return t; | |
2811 | /* Don't VERIFY_CONSTANT here; we only want to check that we got a | |
2812 | CONSTRUCTOR. */ | |
2813 | if (!*non_constant_p | |
2814 | && TREE_CODE (whole) != VECTOR_CST | |
2815 | && TREE_CODE (whole) != CONSTRUCTOR) | |
2816 | { | |
f83e6885 | 2817 | if (!ctx->quiet) |
09b42213 | 2818 | error ("%qE is not a constant expression", orig_whole); |
2819 | *non_constant_p = true; | |
2820 | } | |
2821 | if (*non_constant_p) | |
2822 | return t; | |
2823 | ||
2824 | if (TREE_CODE (whole) == VECTOR_CST) | |
2825 | return fold_ternary (BIT_FIELD_REF, TREE_TYPE (t), whole, | |
2826 | TREE_OPERAND (t, 1), TREE_OPERAND (t, 2)); | |
2827 | ||
2828 | start = TREE_OPERAND (t, 2); | |
2829 | istart = tree_to_shwi (start); | |
2830 | isize = tree_to_shwi (TREE_OPERAND (t, 1)); | |
2831 | utype = TREE_TYPE (t); | |
2832 | if (!TYPE_UNSIGNED (utype)) | |
2833 | utype = build_nonstandard_integer_type (TYPE_PRECISION (utype), 1); | |
2834 | retval = build_int_cst (utype, 0); | |
2835 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (whole), i, field, value) | |
2836 | { | |
2837 | tree bitpos = bit_position (field); | |
2838 | if (bitpos == start && DECL_SIZE (field) == TREE_OPERAND (t, 1)) | |
2839 | return value; | |
2840 | if (TREE_CODE (TREE_TYPE (field)) == INTEGER_TYPE | |
2841 | && TREE_CODE (value) == INTEGER_CST | |
2842 | && tree_fits_shwi_p (bitpos) | |
2843 | && tree_fits_shwi_p (DECL_SIZE (field))) | |
2844 | { | |
2845 | HOST_WIDE_INT bit = tree_to_shwi (bitpos); | |
2846 | HOST_WIDE_INT sz = tree_to_shwi (DECL_SIZE (field)); | |
2847 | HOST_WIDE_INT shift; | |
2848 | if (bit >= istart && bit + sz <= istart + isize) | |
2849 | { | |
2850 | fldval = fold_convert (utype, value); | |
2851 | mask = build_int_cst_type (utype, -1); | |
2852 | mask = fold_build2 (LSHIFT_EXPR, utype, mask, | |
2853 | size_int (TYPE_PRECISION (utype) - sz)); | |
2854 | mask = fold_build2 (RSHIFT_EXPR, utype, mask, | |
2855 | size_int (TYPE_PRECISION (utype) - sz)); | |
2856 | fldval = fold_build2 (BIT_AND_EXPR, utype, fldval, mask); | |
2857 | shift = bit - istart; | |
2858 | if (BYTES_BIG_ENDIAN) | |
2859 | shift = TYPE_PRECISION (utype) - shift - sz; | |
2860 | fldval = fold_build2 (LSHIFT_EXPR, utype, fldval, | |
2861 | size_int (shift)); | |
2862 | retval = fold_build2 (BIT_IOR_EXPR, utype, retval, fldval); | |
2863 | fld_seen = true; | |
2864 | } | |
2865 | } | |
2866 | } | |
2867 | if (fld_seen) | |
2868 | return fold_convert (TREE_TYPE (t), retval); | |
2869 | gcc_unreachable (); | |
2870 | return error_mark_node; | |
2871 | } | |
2872 | ||
2873 | /* Subroutine of cxx_eval_constant_expression. | |
2874 | Evaluate a short-circuited logical expression T in the context | |
2875 | of a given constexpr CALL. BAILOUT_VALUE is the value for | |
2876 | early return. CONTINUE_VALUE is used here purely for | |
2877 | sanity check purposes. */ | |
2878 | ||
2879 | static tree | |
cf72f34d | 2880 | cxx_eval_logical_expression (const constexpr_ctx *ctx, tree t, |
09b42213 | 2881 | tree bailout_value, tree continue_value, |
1227ba74 | 2882 | bool lval, |
09b42213 | 2883 | bool *non_constant_p, bool *overflow_p) |
2884 | { | |
2885 | tree r; | |
cf72f34d | 2886 | tree lhs = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), |
1227ba74 | 2887 | lval, |
b2a43197 | 2888 | non_constant_p, overflow_p); |
09b42213 | 2889 | VERIFY_CONSTANT (lhs); |
2890 | if (tree_int_cst_equal (lhs, bailout_value)) | |
2891 | return lhs; | |
2892 | gcc_assert (tree_int_cst_equal (lhs, continue_value)); | |
cf72f34d | 2893 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), |
1227ba74 | 2894 | lval, non_constant_p, |
b2a43197 | 2895 | overflow_p); |
09b42213 | 2896 | VERIFY_CONSTANT (r); |
2897 | return r; | |
2898 | } | |
2899 | ||
2900 | /* REF is a COMPONENT_REF designating a particular field. V is a vector of | |
2901 | CONSTRUCTOR elements to initialize (part of) an object containing that | |
2902 | field. Return a pointer to the constructor_elt corresponding to the | |
2903 | initialization of the field. */ | |
2904 | ||
2905 | static constructor_elt * | |
2906 | base_field_constructor_elt (vec<constructor_elt, va_gc> *v, tree ref) | |
2907 | { | |
2908 | tree aggr = TREE_OPERAND (ref, 0); | |
2909 | tree field = TREE_OPERAND (ref, 1); | |
2910 | HOST_WIDE_INT i; | |
2911 | constructor_elt *ce; | |
2912 | ||
2913 | gcc_assert (TREE_CODE (ref) == COMPONENT_REF); | |
2914 | ||
2915 | if (TREE_CODE (aggr) == COMPONENT_REF) | |
2916 | { | |
2917 | constructor_elt *base_ce | |
2918 | = base_field_constructor_elt (v, aggr); | |
2919 | v = CONSTRUCTOR_ELTS (base_ce->value); | |
2920 | } | |
2921 | ||
2922 | for (i = 0; vec_safe_iterate (v, i, &ce); ++i) | |
2923 | if (ce->index == field) | |
2924 | return ce; | |
2925 | ||
2926 | gcc_unreachable (); | |
2927 | return NULL; | |
2928 | } | |
2929 | ||
cf72f34d | 2930 | /* Some of the expressions fed to the constexpr mechanism are calls to |
2931 | constructors, which have type void. In that case, return the type being | |
2932 | initialized by the constructor. */ | |
2933 | ||
2934 | static tree | |
2935 | initialized_type (tree t) | |
2936 | { | |
2937 | if (TYPE_P (t)) | |
2938 | return t; | |
59183fff | 2939 | tree type = TREE_TYPE (t); |
48c03f15 | 2940 | if (TREE_CODE (t) == CALL_EXPR) |
cf72f34d | 2941 | { |
2942 | /* A constructor call has void type, so we need to look deeper. */ | |
2943 | tree fn = get_function_named_in_call (t); | |
2944 | if (fn && TREE_CODE (fn) == FUNCTION_DECL | |
2945 | && DECL_CXX_CONSTRUCTOR_P (fn)) | |
2946 | type = DECL_CONTEXT (fn); | |
2947 | } | |
48c03f15 | 2948 | else if (TREE_CODE (t) == COMPOUND_EXPR) |
2949 | return initialized_type (TREE_OPERAND (t, 1)); | |
59183fff | 2950 | else if (TREE_CODE (t) == AGGR_INIT_EXPR) |
2951 | type = TREE_TYPE (AGGR_INIT_EXPR_SLOT (t)); | |
2952 | return cv_unqualified (type); | |
cf72f34d | 2953 | } |
2954 | ||
2955 | /* We're about to initialize element INDEX of an array or class from VALUE. | |
2956 | Set up NEW_CTX appropriately by adjusting .object to refer to the | |
2957 | subobject and creating a new CONSTRUCTOR if the element is itself | |
2958 | a class or array. */ | |
2959 | ||
2960 | static void | |
2961 | init_subob_ctx (const constexpr_ctx *ctx, constexpr_ctx &new_ctx, | |
2962 | tree index, tree &value) | |
2963 | { | |
2964 | new_ctx = *ctx; | |
2965 | ||
2966 | if (index && TREE_CODE (index) != INTEGER_CST | |
2967 | && TREE_CODE (index) != FIELD_DECL) | |
2968 | /* This won't have an element in the new CONSTRUCTOR. */ | |
2969 | return; | |
2970 | ||
2971 | tree type = initialized_type (value); | |
2972 | if (!AGGREGATE_TYPE_P (type) && !VECTOR_TYPE_P (type)) | |
2973 | /* A non-aggregate member doesn't get its own CONSTRUCTOR. */ | |
2974 | return; | |
2975 | ||
2976 | /* The sub-aggregate initializer might contain a placeholder; | |
2977 | update object to refer to the subobject and ctor to refer to | |
2978 | the (newly created) sub-initializer. */ | |
2979 | if (ctx->object) | |
2980 | new_ctx.object = build_ctor_subob_ref (index, type, ctx->object); | |
2981 | tree elt = build_constructor (type, NULL); | |
165d0d5b | 2982 | CONSTRUCTOR_NO_CLEARING (elt) = true; |
cf72f34d | 2983 | new_ctx.ctor = elt; |
2984 | ||
2985 | if (TREE_CODE (value) == TARGET_EXPR) | |
2986 | /* Avoid creating another CONSTRUCTOR when we expand the TARGET_EXPR. */ | |
2987 | value = TARGET_EXPR_INITIAL (value); | |
2988 | } | |
2989 | ||
2990 | /* We're about to process an initializer for a class or array TYPE. Make | |
2991 | sure that CTX is set up appropriately. */ | |
2992 | ||
2993 | static void | |
2994 | verify_ctor_sanity (const constexpr_ctx *ctx, tree type) | |
2995 | { | |
2996 | /* We don't bother building a ctor for an empty base subobject. */ | |
2997 | if (is_empty_class (type)) | |
2998 | return; | |
2999 | ||
3000 | /* We're in the middle of an initializer that might involve placeholders; | |
3001 | our caller should have created a CONSTRUCTOR for us to put the | |
3002 | initializer into. We will either return that constructor or T. */ | |
3003 | gcc_assert (ctx->ctor); | |
3004 | gcc_assert (same_type_ignoring_top_level_qualifiers_p | |
3005 | (type, TREE_TYPE (ctx->ctor))); | |
bbf58224 | 3006 | /* We used to check that ctx->ctor was empty, but that isn't the case when |
3007 | the object is zero-initialized before calling the constructor. */ | |
cf72f34d | 3008 | if (ctx->object) |
d9751a3c | 3009 | { |
3010 | tree otype = TREE_TYPE (ctx->object); | |
3011 | gcc_assert (same_type_ignoring_top_level_qualifiers_p (type, otype) | |
3012 | /* Handle flexible array members. */ | |
3013 | || (TREE_CODE (otype) == ARRAY_TYPE | |
3014 | && TYPE_DOMAIN (otype) == NULL_TREE | |
3015 | && TREE_CODE (type) == ARRAY_TYPE | |
3016 | && (same_type_ignoring_top_level_qualifiers_p | |
3017 | (TREE_TYPE (type), TREE_TYPE (otype))))); | |
3018 | } | |
cf72f34d | 3019 | gcc_assert (!ctx->object || !DECL_P (ctx->object) |
3020 | || *(ctx->values->get (ctx->object)) == ctx->ctor); | |
3021 | } | |
3022 | ||
09b42213 | 3023 | /* Subroutine of cxx_eval_constant_expression. |
3024 | The expression tree T denotes a C-style array or a C-style | |
3025 | aggregate. Reduce it to a constant expression. */ | |
3026 | ||
3027 | static tree | |
cf72f34d | 3028 | cxx_eval_bare_aggregate (const constexpr_ctx *ctx, tree t, |
1227ba74 | 3029 | bool lval, |
09b42213 | 3030 | bool *non_constant_p, bool *overflow_p) |
3031 | { | |
3032 | vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (t); | |
09b42213 | 3033 | bool changed = false; |
3034 | gcc_assert (!BRACE_ENCLOSED_INITIALIZER_P (t)); | |
68464393 | 3035 | tree type = TREE_TYPE (t); |
cf72f34d | 3036 | |
68464393 | 3037 | constexpr_ctx new_ctx; |
d2dd85e3 | 3038 | if (TYPE_PTRMEMFUNC_P (type) || VECTOR_TYPE_P (type)) |
68464393 | 3039 | { |
d2dd85e3 | 3040 | /* We don't really need the ctx->ctor business for a PMF or |
3041 | vector, but it's simpler to use the same code. */ | |
68464393 | 3042 | new_ctx = *ctx; |
3043 | new_ctx.ctor = build_constructor (type, NULL); | |
3044 | new_ctx.object = NULL_TREE; | |
3045 | ctx = &new_ctx; | |
3046 | }; | |
3047 | verify_ctor_sanity (ctx, type); | |
cf72f34d | 3048 | vec<constructor_elt, va_gc> **p = &CONSTRUCTOR_ELTS (ctx->ctor); |
3049 | vec_alloc (*p, vec_safe_length (v)); | |
3050 | ||
58b0f9ce | 3051 | unsigned i; |
3052 | tree index, value; | |
3053 | bool constant_p = true; | |
3054 | bool side_effects_p = false; | |
cf72f34d | 3055 | FOR_EACH_CONSTRUCTOR_ELT (v, i, index, value) |
09b42213 | 3056 | { |
5ae773e4 | 3057 | tree orig_value = value; |
cf72f34d | 3058 | init_subob_ctx (ctx, new_ctx, index, value); |
3059 | if (new_ctx.ctor != ctx->ctor) | |
3060 | /* If we built a new CONSTRUCTOR, attach it now so that other | |
3061 | initializers can refer to it. */ | |
3062 | CONSTRUCTOR_APPEND_ELT (*p, index, new_ctx.ctor); | |
3063 | tree elt = cxx_eval_constant_expression (&new_ctx, value, | |
1227ba74 | 3064 | lval, |
b2a43197 | 3065 | non_constant_p, overflow_p); |
09b42213 | 3066 | /* Don't VERIFY_CONSTANT here. */ |
f83e6885 | 3067 | if (ctx->quiet && *non_constant_p) |
cf72f34d | 3068 | break; |
5ae773e4 | 3069 | if (elt != orig_value) |
09b42213 | 3070 | changed = true; |
58b0f9ce | 3071 | |
3072 | if (!TREE_CONSTANT (elt)) | |
3073 | constant_p = false; | |
3074 | if (TREE_SIDE_EFFECTS (elt)) | |
3075 | side_effects_p = true; | |
cf72f34d | 3076 | if (index && TREE_CODE (index) == COMPONENT_REF) |
09b42213 | 3077 | { |
3078 | /* This is an initialization of a vfield inside a base | |
3079 | subaggregate that we already initialized; push this | |
3080 | initialization into the previous initialization. */ | |
cf72f34d | 3081 | constructor_elt *inner = base_field_constructor_elt (*p, index); |
09b42213 | 3082 | inner->value = elt; |
cf72f34d | 3083 | changed = true; |
09b42213 | 3084 | } |
cf72f34d | 3085 | else if (index |
3086 | && (TREE_CODE (index) == NOP_EXPR | |
3087 | || TREE_CODE (index) == POINTER_PLUS_EXPR)) | |
09b42213 | 3088 | { |
3089 | /* This is an initializer for an empty base; now that we've | |
3090 | checked that it's constant, we can ignore it. */ | |
cf72f34d | 3091 | gcc_assert (is_empty_class (TREE_TYPE (TREE_TYPE (index)))); |
3092 | changed = true; | |
3093 | } | |
09b42213 | 3094 | else |
79e65a6b | 3095 | { |
0dd49b5a | 3096 | if (new_ctx.ctor != ctx->ctor) |
3097 | { | |
3098 | /* We appended this element above; update the value. */ | |
3099 | gcc_assert ((*p)->last().index == index); | |
3100 | (*p)->last().value = elt; | |
3101 | } | |
3102 | else | |
3103 | CONSTRUCTOR_APPEND_ELT (*p, index, elt); | |
3104 | /* Adding or replacing an element might change the ctor's flags. */ | |
79e65a6b | 3105 | TREE_CONSTANT (ctx->ctor) = constant_p; |
3106 | TREE_SIDE_EFFECTS (ctx->ctor) = side_effects_p; | |
3107 | } | |
09b42213 | 3108 | } |
3109 | if (*non_constant_p || !changed) | |
cf72f34d | 3110 | return t; |
3111 | t = ctx->ctor; | |
3112 | /* We're done building this CONSTRUCTOR, so now we can interpret an | |
3113 | element without an explicit initializer as value-initialized. */ | |
165d0d5b | 3114 | CONSTRUCTOR_NO_CLEARING (t) = false; |
58b0f9ce | 3115 | TREE_CONSTANT (t) = constant_p; |
3116 | TREE_SIDE_EFFECTS (t) = side_effects_p; | |
68464393 | 3117 | if (VECTOR_TYPE_P (type)) |
09b42213 | 3118 | t = fold (t); |
3119 | return t; | |
3120 | } | |
3121 | ||
3122 | /* Subroutine of cxx_eval_constant_expression. | |
3123 | The expression tree T is a VEC_INIT_EXPR which denotes the desired | |
3124 | initialization of a non-static data member of array type. Reduce it to a | |
3125 | CONSTRUCTOR. | |
3126 | ||
3127 | Note that apart from value-initialization (when VALUE_INIT is true), | |
3128 | this is only intended to support value-initialization and the | |
3129 | initializations done by defaulted constructors for classes with | |
3130 | non-static data members of array type. In this case, VEC_INIT_EXPR_INIT | |
3131 | will either be NULL_TREE for the default constructor, or a COMPONENT_REF | |
3132 | for the copy/move constructor. */ | |
3133 | ||
3134 | static tree | |
cf72f34d | 3135 | cxx_eval_vec_init_1 (const constexpr_ctx *ctx, tree atype, tree init, |
1227ba74 | 3136 | bool value_init, bool lval, |
09b42213 | 3137 | bool *non_constant_p, bool *overflow_p) |
3138 | { | |
3139 | tree elttype = TREE_TYPE (atype); | |
cf72f34d | 3140 | verify_ctor_sanity (ctx, atype); |
3141 | vec<constructor_elt, va_gc> **p = &CONSTRUCTOR_ELTS (ctx->ctor); | |
09b42213 | 3142 | bool pre_init = false; |
3e520b97 | 3143 | unsigned HOST_WIDE_INT i; |
c4970310 | 3144 | tsubst_flags_t complain = ctx->quiet ? tf_none : tf_warning_or_error; |
09b42213 | 3145 | |
3146 | /* For the default constructor, build up a call to the default | |
3147 | constructor of the element type. We only need to handle class types | |
3148 | here, as for a constructor to be constexpr, all members must be | |
3149 | initialized, which for a defaulted default constructor means they must | |
3150 | be of a class type with a constexpr default constructor. */ | |
3151 | if (TREE_CODE (elttype) == ARRAY_TYPE) | |
3152 | /* We only do this at the lowest level. */; | |
3153 | else if (value_init) | |
3154 | { | |
c4970310 | 3155 | init = build_value_init (elttype, complain); |
09b42213 | 3156 | pre_init = true; |
3157 | } | |
3158 | else if (!init) | |
3159 | { | |
02fafda8 | 3160 | releasing_vec argvec; |
09b42213 | 3161 | init = build_special_member_call (NULL_TREE, complete_ctor_identifier, |
3162 | &argvec, elttype, LOOKUP_NORMAL, | |
c4970310 | 3163 | complain); |
59183fff | 3164 | init = build_aggr_init_expr (elttype, init); |
09b42213 | 3165 | pre_init = true; |
3166 | } | |
3167 | ||
51f0c7e2 | 3168 | tree nelts = get_array_or_vector_nelts (ctx, atype, non_constant_p, |
3169 | overflow_p); | |
3170 | unsigned HOST_WIDE_INT max = tree_to_uhwi (nelts); | |
3e520b97 | 3171 | for (i = 0; i < max; ++i) |
09b42213 | 3172 | { |
3173 | tree idx = build_int_cst (size_type_node, i); | |
3174 | tree eltinit; | |
d9377ad5 | 3175 | bool reuse = false; |
cf72f34d | 3176 | constexpr_ctx new_ctx; |
3177 | init_subob_ctx (ctx, new_ctx, idx, pre_init ? init : elttype); | |
3178 | if (new_ctx.ctor != ctx->ctor) | |
3179 | CONSTRUCTOR_APPEND_ELT (*p, idx, new_ctx.ctor); | |
09b42213 | 3180 | if (TREE_CODE (elttype) == ARRAY_TYPE) |
3181 | { | |
3182 | /* A multidimensional array; recurse. */ | |
3183 | if (value_init || init == NULL_TREE) | |
d9377ad5 | 3184 | { |
3185 | eltinit = NULL_TREE; | |
3186 | reuse = i == 0; | |
3187 | } | |
09b42213 | 3188 | else |
c4970310 | 3189 | eltinit = cp_build_array_ref (input_location, init, idx, complain); |
cf72f34d | 3190 | eltinit = cxx_eval_vec_init_1 (&new_ctx, elttype, eltinit, value_init, |
1227ba74 | 3191 | lval, |
09b42213 | 3192 | non_constant_p, overflow_p); |
3193 | } | |
3194 | else if (pre_init) | |
3195 | { | |
3196 | /* Initializing an element using value or default initialization | |
3197 | we just pre-built above. */ | |
0e9064d2 | 3198 | if (init == void_node) |
3199 | /* Trivial default-init, don't do anything to the CONSTRUCTOR. */ | |
3200 | return ctx->ctor; | |
d9377ad5 | 3201 | eltinit = cxx_eval_constant_expression (&new_ctx, init, lval, |
3202 | non_constant_p, overflow_p); | |
3203 | reuse = i == 0; | |
09b42213 | 3204 | } |
3205 | else | |
3206 | { | |
3207 | /* Copying an element. */ | |
3208 | gcc_assert (same_type_ignoring_top_level_qualifiers_p | |
3209 | (atype, TREE_TYPE (init))); | |
c4970310 | 3210 | eltinit = cp_build_array_ref (input_location, init, idx, complain); |
18bede74 | 3211 | if (!lvalue_p (init)) |
09b42213 | 3212 | eltinit = move (eltinit); |
c4970310 | 3213 | eltinit = force_rvalue (eltinit, complain); |
eb7c25cc | 3214 | eltinit = cxx_eval_constant_expression (&new_ctx, eltinit, lval, |
3215 | non_constant_p, overflow_p); | |
09b42213 | 3216 | } |
f83e6885 | 3217 | if (*non_constant_p && !ctx->quiet) |
cf72f34d | 3218 | break; |
3219 | if (new_ctx.ctor != ctx->ctor) | |
3220 | { | |
3221 | /* We appended this element above; update the value. */ | |
3222 | gcc_assert ((*p)->last().index == idx); | |
3223 | (*p)->last().value = eltinit; | |
3224 | } | |
3225 | else | |
3226 | CONSTRUCTOR_APPEND_ELT (*p, idx, eltinit); | |
d9377ad5 | 3227 | /* Reuse the result of cxx_eval_constant_expression call |
eb7c25cc | 3228 | from the first iteration to all others if it is a constant |
3229 | initializer that doesn't require relocations. */ | |
d9377ad5 | 3230 | if (reuse |
3231 | && max > 1 | |
eb7c25cc | 3232 | && (eltinit == NULL_TREE |
3233 | || (initializer_constant_valid_p (eltinit, TREE_TYPE (eltinit)) | |
3234 | == null_pointer_node))) | |
d9377ad5 | 3235 | { |
3236 | if (new_ctx.ctor != ctx->ctor) | |
3237 | eltinit = new_ctx.ctor; | |
228a2cd8 | 3238 | tree range = build2 (RANGE_EXPR, size_type_node, |
3239 | build_int_cst (size_type_node, 1), | |
3240 | build_int_cst (size_type_node, max - 1)); | |
3241 | CONSTRUCTOR_APPEND_ELT (*p, range, unshare_constructor (eltinit)); | |
d9377ad5 | 3242 | break; |
3243 | } | |
228a2cd8 | 3244 | else if (i == 0) |
3245 | vec_safe_reserve (*p, max); | |
09b42213 | 3246 | } |
3247 | ||
3248 | if (!*non_constant_p) | |
3249 | { | |
cf72f34d | 3250 | init = ctx->ctor; |
165d0d5b | 3251 | CONSTRUCTOR_NO_CLEARING (init) = false; |
09b42213 | 3252 | } |
09b42213 | 3253 | return init; |
3254 | } | |
3255 | ||
3256 | static tree | |
cf72f34d | 3257 | cxx_eval_vec_init (const constexpr_ctx *ctx, tree t, |
1227ba74 | 3258 | bool lval, |
09b42213 | 3259 | bool *non_constant_p, bool *overflow_p) |
3260 | { | |
3261 | tree atype = TREE_TYPE (t); | |
3262 | tree init = VEC_INIT_EXPR_INIT (t); | |
cf72f34d | 3263 | tree r = cxx_eval_vec_init_1 (ctx, atype, init, |
09b42213 | 3264 | VEC_INIT_EXPR_VALUE_INIT (t), |
1227ba74 | 3265 | lval, non_constant_p, overflow_p); |
09b42213 | 3266 | if (*non_constant_p) |
3267 | return t; | |
3268 | else | |
3269 | return r; | |
3270 | } | |
3271 | ||
6b53d686 | 3272 | /* Like same_type_ignoring_top_level_qualifiers_p, but also handle the case |
3273 | where the desired type is an array of unknown bounds because the variable | |
3274 | has had its bounds deduced since the wrapping expression was created. */ | |
3275 | ||
3276 | static bool | |
3277 | same_type_ignoring_tlq_and_bounds_p (tree type1, tree type2) | |
3278 | { | |
3279 | while (TREE_CODE (type1) == ARRAY_TYPE | |
3280 | && TREE_CODE (type2) == ARRAY_TYPE | |
3281 | && (!TYPE_DOMAIN (type1) || !TYPE_DOMAIN (type2))) | |
3282 | { | |
3283 | type1 = TREE_TYPE (type1); | |
3284 | type2 = TREE_TYPE (type2); | |
3285 | } | |
3286 | return same_type_ignoring_top_level_qualifiers_p (type1, type2); | |
3287 | } | |
3288 | ||
09b42213 | 3289 | /* A less strict version of fold_indirect_ref_1, which requires cv-quals to |
3290 | match. We want to be less strict for simple *& folding; if we have a | |
3291 | non-const temporary that we access through a const pointer, that should | |
3292 | work. We handle this here rather than change fold_indirect_ref_1 | |
3293 | because we're dealing with things like ADDR_EXPR of INTEGER_CST which | |
3294 | don't really make sense outside of constant expression evaluation. Also | |
3295 | we want to allow folding to COMPONENT_REF, which could cause trouble | |
3296 | with TBAA in fold_indirect_ref_1. | |
3297 | ||
3298 | Try to keep this function synced with fold_indirect_ref_1. */ | |
3299 | ||
3300 | static tree | |
3301 | cxx_fold_indirect_ref (location_t loc, tree type, tree op0, bool *empty_base) | |
3302 | { | |
7d8e655d | 3303 | tree sub = op0; |
3304 | tree subtype; | |
3305 | poly_uint64 const_op01; | |
09b42213 | 3306 | |
09b42213 | 3307 | STRIP_NOPS (sub); |
3308 | subtype = TREE_TYPE (sub); | |
d03fa520 | 3309 | if (!INDIRECT_TYPE_P (subtype)) |
09b42213 | 3310 | return NULL_TREE; |
3311 | ||
3312 | if (TREE_CODE (sub) == ADDR_EXPR) | |
3313 | { | |
3314 | tree op = TREE_OPERAND (sub, 0); | |
3315 | tree optype = TREE_TYPE (op); | |
3316 | ||
3317 | /* *&CONST_DECL -> to the value of the const decl. */ | |
3318 | if (TREE_CODE (op) == CONST_DECL) | |
3319 | return DECL_INITIAL (op); | |
3320 | /* *&p => p; make sure to handle *&"str"[cst] here. */ | |
6b53d686 | 3321 | if (same_type_ignoring_tlq_and_bounds_p (optype, type)) |
09b42213 | 3322 | { |
3323 | tree fop = fold_read_from_constant_string (op); | |
3324 | if (fop) | |
3325 | return fop; | |
3326 | else | |
3327 | return op; | |
3328 | } | |
3329 | /* *(foo *)&fooarray => fooarray[0] */ | |
3330 | else if (TREE_CODE (optype) == ARRAY_TYPE | |
3331 | && (same_type_ignoring_top_level_qualifiers_p | |
3332 | (type, TREE_TYPE (optype)))) | |
3333 | { | |
3334 | tree type_domain = TYPE_DOMAIN (optype); | |
3335 | tree min_val = size_zero_node; | |
3336 | if (type_domain && TYPE_MIN_VALUE (type_domain)) | |
3337 | min_val = TYPE_MIN_VALUE (type_domain); | |
3338 | return build4_loc (loc, ARRAY_REF, type, op, min_val, | |
3339 | NULL_TREE, NULL_TREE); | |
3340 | } | |
3341 | /* *(foo *)&complexfoo => __real__ complexfoo */ | |
3342 | else if (TREE_CODE (optype) == COMPLEX_TYPE | |
3343 | && (same_type_ignoring_top_level_qualifiers_p | |
3344 | (type, TREE_TYPE (optype)))) | |
3345 | return fold_build1_loc (loc, REALPART_EXPR, type, op); | |
3346 | /* *(foo *)&vectorfoo => BIT_FIELD_REF<vectorfoo,...> */ | |
76249021 | 3347 | else if (VECTOR_TYPE_P (optype) |
09b42213 | 3348 | && (same_type_ignoring_top_level_qualifiers_p |
3349 | (type, TREE_TYPE (optype)))) | |
3350 | { | |
3351 | tree part_width = TYPE_SIZE (type); | |
3352 | tree index = bitsize_int (0); | |
7d8e655d | 3353 | return fold_build3_loc (loc, BIT_FIELD_REF, type, op, part_width, |
3354 | index); | |
09b42213 | 3355 | } |
3356 | /* Also handle conversion to an empty base class, which | |
3357 | is represented with a NOP_EXPR. */ | |
3358 | else if (is_empty_class (type) | |
3359 | && CLASS_TYPE_P (optype) | |
3360 | && DERIVED_FROM_P (type, optype)) | |
3361 | { | |
3362 | *empty_base = true; | |
3363 | return op; | |
3364 | } | |
3365 | /* *(foo *)&struct_with_foo_field => COMPONENT_REF */ | |
3366 | else if (RECORD_OR_UNION_TYPE_P (optype)) | |
3367 | { | |
3368 | tree field = TYPE_FIELDS (optype); | |
3369 | for (; field; field = DECL_CHAIN (field)) | |
3370 | if (TREE_CODE (field) == FIELD_DECL | |
a48667ee | 3371 | && TREE_TYPE (field) != error_mark_node |
09b42213 | 3372 | && integer_zerop (byte_position (field)) |
3373 | && (same_type_ignoring_top_level_qualifiers_p | |
3374 | (TREE_TYPE (field), type))) | |
a48667ee | 3375 | return fold_build3 (COMPONENT_REF, type, op, field, NULL_TREE); |
09b42213 | 3376 | } |
3377 | } | |
3378 | else if (TREE_CODE (sub) == POINTER_PLUS_EXPR | |
7d8e655d | 3379 | && poly_int_tree_p (TREE_OPERAND (sub, 1), &const_op01)) |
09b42213 | 3380 | { |
3381 | tree op00 = TREE_OPERAND (sub, 0); | |
3382 | tree op01 = TREE_OPERAND (sub, 1); | |
3383 | ||
3384 | STRIP_NOPS (op00); | |
3385 | if (TREE_CODE (op00) == ADDR_EXPR) | |
3386 | { | |
3387 | tree op00type; | |
3388 | op00 = TREE_OPERAND (op00, 0); | |
3389 | op00type = TREE_TYPE (op00); | |
3390 | ||
3391 | /* ((foo*)&vectorfoo)[1] => BIT_FIELD_REF<vectorfoo,...> */ | |
76249021 | 3392 | if (VECTOR_TYPE_P (op00type) |
7d8e655d | 3393 | && same_type_ignoring_top_level_qualifiers_p |
3394 | (type, TREE_TYPE (op00type)) | |
3395 | /* POINTER_PLUS_EXPR second operand is sizetype, unsigned, | |
3396 | but we want to treat offsets with MSB set as negative. | |
3397 | For the code below negative offsets are invalid and | |
3398 | TYPE_SIZE of the element is something unsigned, so | |
3399 | check whether op01 fits into poly_int64, which implies | |
3400 | it is from 0 to INTTYPE_MAXIMUM (HOST_WIDE_INT), and | |
3401 | then just use poly_uint64 because we want to treat the | |
3402 | value as unsigned. */ | |
3403 | && tree_fits_poly_int64_p (op01)) | |
09b42213 | 3404 | { |
09b42213 | 3405 | tree part_width = TYPE_SIZE (type); |
7d8e655d | 3406 | poly_uint64 max_offset |
3407 | = (tree_to_uhwi (part_width) / BITS_PER_UNIT | |
3408 | * TYPE_VECTOR_SUBPARTS (op00type)); | |
3409 | if (known_lt (const_op01, max_offset)) | |
3410 | { | |
3411 | tree index = bitsize_int (const_op01 * BITS_PER_UNIT); | |
3412 | return fold_build3_loc (loc, | |
3413 | BIT_FIELD_REF, type, op00, | |
3414 | part_width, index); | |
3415 | } | |
09b42213 | 3416 | } |
3417 | /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */ | |
3418 | else if (TREE_CODE (op00type) == COMPLEX_TYPE | |
3419 | && (same_type_ignoring_top_level_qualifiers_p | |
3420 | (type, TREE_TYPE (op00type)))) | |
3421 | { | |
7d8e655d | 3422 | if (known_eq (wi::to_poly_offset (TYPE_SIZE_UNIT (type)), |
3423 | const_op01)) | |
09b42213 | 3424 | return fold_build1_loc (loc, IMAGPART_EXPR, type, op00); |
3425 | } | |
3426 | /* ((foo *)&fooarray)[1] => fooarray[1] */ | |
3427 | else if (TREE_CODE (op00type) == ARRAY_TYPE | |
3428 | && (same_type_ignoring_top_level_qualifiers_p | |
3429 | (type, TREE_TYPE (op00type)))) | |
3430 | { | |
3431 | tree type_domain = TYPE_DOMAIN (op00type); | |
3432 | tree min_val = size_zero_node; | |
3433 | if (type_domain && TYPE_MIN_VALUE (type_domain)) | |
3434 | min_val = TYPE_MIN_VALUE (type_domain); | |
53fa96c0 | 3435 | offset_int off = wi::to_offset (op01); |
3436 | offset_int el_sz = wi::to_offset (TYPE_SIZE_UNIT (type)); | |
3437 | offset_int remainder; | |
3438 | off = wi::divmod_trunc (off, el_sz, SIGNED, &remainder); | |
3439 | if (remainder == 0 && TREE_CODE (min_val) == INTEGER_CST) | |
3440 | { | |
3441 | off = off + wi::to_offset (min_val); | |
3442 | op01 = wide_int_to_tree (sizetype, off); | |
3443 | return build4_loc (loc, ARRAY_REF, type, op00, op01, | |
3444 | NULL_TREE, NULL_TREE); | |
3445 | } | |
09b42213 | 3446 | } |
3447 | /* Also handle conversion to an empty base class, which | |
3448 | is represented with a NOP_EXPR. */ | |
3449 | else if (is_empty_class (type) | |
3450 | && CLASS_TYPE_P (op00type) | |
3451 | && DERIVED_FROM_P (type, op00type)) | |
3452 | { | |
3453 | *empty_base = true; | |
3454 | return op00; | |
3455 | } | |
3456 | /* ((foo *)&struct_with_foo_field)[1] => COMPONENT_REF */ | |
3457 | else if (RECORD_OR_UNION_TYPE_P (op00type)) | |
3458 | { | |
3459 | tree field = TYPE_FIELDS (op00type); | |
3460 | for (; field; field = DECL_CHAIN (field)) | |
3461 | if (TREE_CODE (field) == FIELD_DECL | |
a48667ee | 3462 | && TREE_TYPE (field) != error_mark_node |
09b42213 | 3463 | && tree_int_cst_equal (byte_position (field), op01) |
3464 | && (same_type_ignoring_top_level_qualifiers_p | |
3465 | (TREE_TYPE (field), type))) | |
a48667ee | 3466 | return fold_build3 (COMPONENT_REF, type, op00, |
3467 | field, NULL_TREE); | |
09b42213 | 3468 | } |
3469 | } | |
3470 | } | |
3471 | /* *(foo *)fooarrptr => (*fooarrptr)[0] */ | |
3472 | else if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE | |
3473 | && (same_type_ignoring_top_level_qualifiers_p | |
3474 | (type, TREE_TYPE (TREE_TYPE (subtype))))) | |
3475 | { | |
3476 | tree type_domain; | |
3477 | tree min_val = size_zero_node; | |
7d8e655d | 3478 | tree newsub |
3479 | = cxx_fold_indirect_ref (loc, TREE_TYPE (subtype), sub, NULL); | |
09b42213 | 3480 | if (newsub) |
3481 | sub = newsub; | |
3482 | else | |
3483 | sub = build1_loc (loc, INDIRECT_REF, TREE_TYPE (subtype), sub); | |
3484 | type_domain = TYPE_DOMAIN (TREE_TYPE (sub)); | |
3485 | if (type_domain && TYPE_MIN_VALUE (type_domain)) | |
3486 | min_val = TYPE_MIN_VALUE (type_domain); | |
3487 | return build4_loc (loc, ARRAY_REF, type, sub, min_val, NULL_TREE, | |
3488 | NULL_TREE); | |
3489 | } | |
3490 | ||
3491 | return NULL_TREE; | |
3492 | } | |
3493 | ||
3494 | static tree | |
cf72f34d | 3495 | cxx_eval_indirect_ref (const constexpr_ctx *ctx, tree t, |
1227ba74 | 3496 | bool lval, |
09b42213 | 3497 | bool *non_constant_p, bool *overflow_p) |
3498 | { | |
3499 | tree orig_op0 = TREE_OPERAND (t, 0); | |
09b42213 | 3500 | bool empty_base = false; |
09b42213 | 3501 | |
d2c63826 | 3502 | /* We can handle a MEM_REF like an INDIRECT_REF, if MEM_REF's second |
3503 | operand is an integer-zero. Otherwise reject the MEM_REF for now. */ | |
3504 | ||
3505 | if (TREE_CODE (t) == MEM_REF | |
3506 | && (!TREE_OPERAND (t, 1) || !integer_zerop (TREE_OPERAND (t, 1)))) | |
3507 | { | |
3508 | gcc_assert (ctx->quiet); | |
3509 | *non_constant_p = true; | |
3510 | return t; | |
3511 | } | |
3512 | ||
7e0f3388 | 3513 | /* First try to simplify it directly. */ |
3514 | tree r = cxx_fold_indirect_ref (EXPR_LOCATION (t), TREE_TYPE (t), orig_op0, | |
3515 | &empty_base); | |
3516 | if (!r) | |
09b42213 | 3517 | { |
7e0f3388 | 3518 | /* If that didn't work, evaluate the operand first. */ |
3519 | tree op0 = cxx_eval_constant_expression (ctx, orig_op0, | |
3520 | /*lval*/false, non_constant_p, | |
3521 | overflow_p); | |
3522 | /* Don't VERIFY_CONSTANT here. */ | |
3523 | if (*non_constant_p) | |
3524 | return t; | |
3525 | ||
cb768824 | 3526 | if (!lval && integer_zerop (op0)) |
3527 | { | |
3528 | if (!ctx->quiet) | |
3529 | error ("dereferencing a null pointer"); | |
3530 | *non_constant_p = true; | |
3531 | return t; | |
3532 | } | |
3533 | ||
7e0f3388 | 3534 | r = cxx_fold_indirect_ref (EXPR_LOCATION (t), TREE_TYPE (t), op0, |
3535 | &empty_base); | |
3536 | if (r == NULL_TREE) | |
09b42213 | 3537 | { |
3538 | /* We couldn't fold to a constant value. Make sure it's not | |
3539 | something we should have been able to fold. */ | |
7e0f3388 | 3540 | tree sub = op0; |
3541 | STRIP_NOPS (sub); | |
3542 | if (TREE_CODE (sub) == ADDR_EXPR) | |
3543 | { | |
3544 | gcc_assert (!same_type_ignoring_top_level_qualifiers_p | |
3545 | (TREE_TYPE (TREE_TYPE (sub)), TREE_TYPE (t))); | |
3546 | /* DR 1188 says we don't have to deal with this. */ | |
3547 | if (!ctx->quiet) | |
3548 | error ("accessing value of %qE through a %qT glvalue in a " | |
3549 | "constant expression", build_fold_indirect_ref (sub), | |
3550 | TREE_TYPE (t)); | |
3551 | *non_constant_p = true; | |
3552 | return t; | |
3553 | } | |
3554 | ||
3555 | if (lval && op0 != orig_op0) | |
3556 | return build1 (INDIRECT_REF, TREE_TYPE (t), op0); | |
3557 | if (!lval) | |
3558 | VERIFY_CONSTANT (t); | |
09b42213 | 3559 | return t; |
3560 | } | |
3561 | } | |
3562 | ||
7e0f3388 | 3563 | r = cxx_eval_constant_expression (ctx, r, |
3564 | lval, non_constant_p, overflow_p); | |
3565 | if (*non_constant_p) | |
3566 | return t; | |
3567 | ||
ce4ffd9e | 3568 | /* If we're pulling out the value of an empty base, just return an empty |
09b42213 | 3569 | CONSTRUCTOR. */ |
1227ba74 | 3570 | if (empty_base && !lval) |
09b42213 | 3571 | { |
09b42213 | 3572 | r = build_constructor (TREE_TYPE (t), NULL); |
3573 | TREE_CONSTANT (r) = true; | |
3574 | } | |
3575 | ||
09b42213 | 3576 | return r; |
3577 | } | |
3578 | ||
3579 | /* Complain about R, a VAR_DECL, not being usable in a constant expression. | |
3580 | Shared between potential_constant_expression and | |
3581 | cxx_eval_constant_expression. */ | |
3582 | ||
3583 | static void | |
3584 | non_const_var_error (tree r) | |
3585 | { | |
3586 | tree type = TREE_TYPE (r); | |
3587 | error ("the value of %qD is not usable in a constant " | |
3588 | "expression", r); | |
3589 | /* Avoid error cascade. */ | |
3590 | if (DECL_INITIAL (r) == error_mark_node) | |
3591 | return; | |
3592 | if (DECL_DECLARED_CONSTEXPR_P (r)) | |
3593 | inform (DECL_SOURCE_LOCATION (r), | |
3594 | "%qD used in its own initializer", r); | |
3595 | else if (INTEGRAL_OR_ENUMERATION_TYPE_P (type)) | |
3596 | { | |
3597 | if (!CP_TYPE_CONST_P (type)) | |
3598 | inform (DECL_SOURCE_LOCATION (r), | |
3599 | "%q#D is not const", r); | |
3600 | else if (CP_TYPE_VOLATILE_P (type)) | |
3601 | inform (DECL_SOURCE_LOCATION (r), | |
3602 | "%q#D is volatile", r); | |
3603 | else if (!DECL_INITIAL (r) | |
c8e3e744 | 3604 | || !TREE_CONSTANT (DECL_INITIAL (r)) |
3605 | || !DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r)) | |
09b42213 | 3606 | inform (DECL_SOURCE_LOCATION (r), |
3607 | "%qD was not initialized with a constant " | |
3608 | "expression", r); | |
3609 | else | |
3610 | gcc_unreachable (); | |
3611 | } | |
90ad495b | 3612 | else if (TYPE_REF_P (type)) |
ac6641ca | 3613 | inform (DECL_SOURCE_LOCATION (r), |
3614 | "%qD was not initialized with a constant " | |
3615 | "expression", r); | |
09b42213 | 3616 | else |
3617 | { | |
3618 | if (cxx_dialect >= cxx11 && !DECL_DECLARED_CONSTEXPR_P (r)) | |
3619 | inform (DECL_SOURCE_LOCATION (r), | |
3620 | "%qD was not declared %<constexpr%>", r); | |
3621 | else | |
3622 | inform (DECL_SOURCE_LOCATION (r), | |
3623 | "%qD does not have integral or enumeration type", | |
3624 | r); | |
3625 | } | |
3626 | } | |
3627 | ||
3628 | /* Subroutine of cxx_eval_constant_expression. | |
3629 | Like cxx_eval_unary_expression, except for trinary expressions. */ | |
3630 | ||
3631 | static tree | |
cf72f34d | 3632 | cxx_eval_trinary_expression (const constexpr_ctx *ctx, tree t, |
1227ba74 | 3633 | bool lval, |
09b42213 | 3634 | bool *non_constant_p, bool *overflow_p) |
3635 | { | |
3636 | int i; | |
3637 | tree args[3]; | |
3638 | tree val; | |
3639 | ||
3640 | for (i = 0; i < 3; i++) | |
3641 | { | |
cf72f34d | 3642 | args[i] = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, i), |
1227ba74 | 3643 | lval, |
b2a43197 | 3644 | non_constant_p, overflow_p); |
09b42213 | 3645 | VERIFY_CONSTANT (args[i]); |
3646 | } | |
3647 | ||
3648 | val = fold_ternary_loc (EXPR_LOCATION (t), TREE_CODE (t), TREE_TYPE (t), | |
3649 | args[0], args[1], args[2]); | |
3650 | if (val == NULL_TREE) | |
3651 | return t; | |
3652 | VERIFY_CONSTANT (val); | |
3653 | return val; | |
3654 | } | |
3655 | ||
33603066 | 3656 | /* True if T was declared in a function declared to be constexpr, and |
3657 | therefore potentially constant in C++14. */ | |
3658 | ||
09b42213 | 3659 | bool |
3660 | var_in_constexpr_fn (tree t) | |
3661 | { | |
3662 | tree ctx = DECL_CONTEXT (t); | |
33603066 | 3663 | return (ctx && TREE_CODE (ctx) == FUNCTION_DECL |
09b42213 | 3664 | && DECL_DECLARED_CONSTEXPR_P (ctx)); |
3665 | } | |
3666 | ||
33603066 | 3667 | /* True if T was declared in a function that might be constexpr: either a |
3668 | function that was declared constexpr, or a C++17 lambda op(). */ | |
3669 | ||
3670 | bool | |
3671 | var_in_maybe_constexpr_fn (tree t) | |
3672 | { | |
40e2decb | 3673 | if (cxx_dialect >= cxx17 |
33603066 | 3674 | && DECL_FUNCTION_SCOPE_P (t) |
3675 | && LAMBDA_FUNCTION_P (DECL_CONTEXT (t))) | |
3676 | return true; | |
3677 | return var_in_constexpr_fn (t); | |
3678 | } | |
3679 | ||
93312944 | 3680 | /* We're assigning INIT to TARGET. In do_build_copy_constructor and |
3681 | build_over_call we implement trivial copy of a class with tail padding using | |
3682 | assignment of character arrays, which is valid in normal code, but not in | |
3683 | constexpr evaluation. We don't need to worry about clobbering tail padding | |
3684 | in constexpr evaluation, so strip the type punning. */ | |
3685 | ||
3686 | static void | |
3687 | maybe_simplify_trivial_copy (tree &target, tree &init) | |
3688 | { | |
3689 | if (TREE_CODE (target) == MEM_REF | |
3690 | && TREE_CODE (init) == MEM_REF | |
3691 | && TREE_TYPE (target) == TREE_TYPE (init) | |
3692 | && TREE_CODE (TREE_TYPE (target)) == ARRAY_TYPE | |
3693 | && TREE_TYPE (TREE_TYPE (target)) == unsigned_char_type_node) | |
3694 | { | |
3695 | target = build_fold_indirect_ref (TREE_OPERAND (target, 0)); | |
3696 | init = build_fold_indirect_ref (TREE_OPERAND (init, 0)); | |
3697 | } | |
3698 | } | |
3699 | ||
9c96033c | 3700 | /* Evaluate an INIT_EXPR or MODIFY_EXPR. */ |
3701 | ||
3702 | static tree | |
3703 | cxx_eval_store_expression (const constexpr_ctx *ctx, tree t, | |
1227ba74 | 3704 | bool lval, |
9c96033c | 3705 | bool *non_constant_p, bool *overflow_p) |
3706 | { | |
3707 | constexpr_ctx new_ctx = *ctx; | |
3708 | ||
8a36d0ec | 3709 | tree init = TREE_OPERAND (t, 1); |
3710 | if (TREE_CLOBBER_P (init)) | |
3711 | /* Just ignore clobbers. */ | |
3712 | return void_node; | |
3713 | ||
9c96033c | 3714 | /* First we figure out where we're storing to. */ |
3715 | tree target = TREE_OPERAND (t, 0); | |
93312944 | 3716 | |
3717 | maybe_simplify_trivial_copy (target, init); | |
3718 | ||
9db9fc38 | 3719 | tree type = TREE_TYPE (target); |
6aaacaf1 | 3720 | bool preeval = SCALAR_TYPE_P (type) || TREE_CODE (t) == MODIFY_EXPR; |
3721 | if (preeval) | |
3722 | { | |
3723 | /* Evaluate the value to be stored without knowing what object it will be | |
3724 | stored in, so that any side-effects happen first. */ | |
3725 | if (!SCALAR_TYPE_P (type)) | |
3726 | new_ctx.ctor = new_ctx.object = NULL_TREE; | |
3727 | init = cxx_eval_constant_expression (&new_ctx, init, false, | |
3728 | non_constant_p, overflow_p); | |
3729 | if (*non_constant_p) | |
3730 | return t; | |
3731 | } | |
9c96033c | 3732 | target = cxx_eval_constant_expression (ctx, target, |
f83e6885 | 3733 | true, |
b2a43197 | 3734 | non_constant_p, overflow_p); |
9c96033c | 3735 | if (*non_constant_p) |
3736 | return t; | |
3737 | ||
cf3cefc9 | 3738 | /* cxx_eval_array_reference for lval = true allows references one past |
3739 | end of array, because it does not know if it is just taking address | |
3740 | (which is valid), or actual dereference. Here we know it is | |
3741 | a dereference, so diagnose it here. */ | |
3742 | for (tree probe = target; probe; ) | |
3743 | { | |
3744 | switch (TREE_CODE (probe)) | |
3745 | { | |
3746 | case ARRAY_REF: | |
3747 | tree nelts, ary; | |
3748 | ary = TREE_OPERAND (probe, 0); | |
51f0c7e2 | 3749 | nelts = get_array_or_vector_nelts (ctx, TREE_TYPE (ary), |
3750 | non_constant_p, overflow_p); | |
cf3cefc9 | 3751 | VERIFY_CONSTANT (nelts); |
3752 | gcc_assert (TREE_CODE (nelts) == INTEGER_CST | |
3753 | && TREE_CODE (TREE_OPERAND (probe, 1)) == INTEGER_CST); | |
cb7bca5f | 3754 | if (wi::to_widest (TREE_OPERAND (probe, 1)) == wi::to_widest (nelts)) |
cf3cefc9 | 3755 | { |
3756 | diag_array_subscript (ctx, ary, TREE_OPERAND (probe, 1)); | |
3757 | *non_constant_p = true; | |
3758 | return t; | |
3759 | } | |
3760 | /* FALLTHRU */ | |
3761 | ||
3762 | case BIT_FIELD_REF: | |
3763 | case COMPONENT_REF: | |
3764 | probe = TREE_OPERAND (probe, 0); | |
3765 | continue; | |
3766 | ||
3767 | default: | |
3768 | probe = NULL_TREE; | |
3769 | continue; | |
3770 | } | |
3771 | } | |
3772 | ||
9db9fc38 | 3773 | if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (target), type)) |
3774 | { | |
3775 | /* For initialization of an empty base, the original target will be | |
3776 | *(base*)this, which the above evaluation resolves to the object | |
3777 | argument, which has the derived type rather than the base type. In | |
3778 | this situation, just evaluate the initializer and return, since | |
3779 | there's no actual data to store. */ | |
3780 | gcc_assert (is_empty_class (type)); | |
3781 | return cxx_eval_constant_expression (ctx, init, false, | |
3782 | non_constant_p, overflow_p); | |
3783 | } | |
3784 | ||
9c96033c | 3785 | /* And then find the underlying variable. */ |
02fafda8 | 3786 | releasing_vec refs; |
9c96033c | 3787 | tree object = NULL_TREE; |
3788 | for (tree probe = target; object == NULL_TREE; ) | |
3789 | { | |
3790 | switch (TREE_CODE (probe)) | |
3791 | { | |
3792 | case BIT_FIELD_REF: | |
3793 | case COMPONENT_REF: | |
3794 | case ARRAY_REF: | |
3795 | vec_safe_push (refs, TREE_OPERAND (probe, 1)); | |
3796 | vec_safe_push (refs, TREE_TYPE (probe)); | |
3797 | probe = TREE_OPERAND (probe, 0); | |
3798 | break; | |
3799 | ||
3800 | default: | |
3801 | object = probe; | |
9c96033c | 3802 | } |
3803 | } | |
3804 | ||
3805 | /* And then find/build up our initializer for the path to the subobject | |
3806 | we're initializing. */ | |
6fe83e54 | 3807 | tree *valp; |
43b7271d | 3808 | if (object == ctx->object && VAR_P (object) |
3809 | && DECL_NAME (object) && ctx->call == NULL) | |
3810 | /* The variable we're building up an aggregate initializer for is outside | |
3811 | the constant-expression, so don't evaluate the store. We check | |
3812 | DECL_NAME to handle TARGET_EXPR temporaries, which are fair game. */ | |
3813 | valp = NULL; | |
3814 | else if (DECL_P (object)) | |
6fe83e54 | 3815 | valp = ctx->values->get (object); |
3816 | else | |
3817 | valp = NULL; | |
9c96033c | 3818 | if (!valp) |
3819 | { | |
3820 | /* A constant-expression cannot modify objects from outside the | |
3821 | constant-expression. */ | |
f83e6885 | 3822 | if (!ctx->quiet) |
ea034e2c | 3823 | error ("modification of %qE is not a constant expression", object); |
9c96033c | 3824 | *non_constant_p = true; |
3825 | return t; | |
3826 | } | |
9db9fc38 | 3827 | type = TREE_TYPE (object); |
a02b42fe | 3828 | bool no_zero_init = true; |
58b0f9ce | 3829 | |
02fafda8 | 3830 | releasing_vec ctors; |
9c96033c | 3831 | while (!refs->is_empty()) |
3832 | { | |
3833 | if (*valp == NULL_TREE) | |
3834 | { | |
3835 | *valp = build_constructor (type, NULL); | |
165d0d5b | 3836 | CONSTRUCTOR_NO_CLEARING (*valp) = no_zero_init; |
9c96033c | 3837 | } |
92fe8840 | 3838 | else if (TREE_CODE (*valp) == STRING_CST) |
3839 | { | |
3840 | /* An array was initialized with a string constant, and now | |
3841 | we're writing into one of its elements. Explode the | |
3842 | single initialization into a set of element | |
3843 | initializations. */ | |
3844 | gcc_assert (TREE_CODE (type) == ARRAY_TYPE); | |
3845 | ||
3846 | tree string = *valp; | |
3847 | tree elt_type = TREE_TYPE (type); | |
3848 | unsigned chars_per_elt = (TYPE_PRECISION (elt_type) | |
3849 | / TYPE_PRECISION (char_type_node)); | |
3850 | unsigned num_elts = TREE_STRING_LENGTH (string) / chars_per_elt; | |
3851 | tree ary_ctor = build_constructor (type, NULL); | |
3852 | ||
3853 | vec_safe_reserve (CONSTRUCTOR_ELTS (ary_ctor), num_elts); | |
3854 | for (unsigned ix = 0; ix != num_elts; ix++) | |
3855 | { | |
3856 | constructor_elt elt = | |
3857 | { | |
3858 | build_int_cst (size_type_node, ix), | |
3859 | extract_string_elt (string, chars_per_elt, ix) | |
3860 | }; | |
3861 | CONSTRUCTOR_ELTS (ary_ctor)->quick_push (elt); | |
3862 | } | |
3863 | ||
3864 | *valp = ary_ctor; | |
3865 | } | |
3866 | ||
a02b42fe | 3867 | /* If the value of object is already zero-initialized, any new ctors for |
3868 | subobjects will also be zero-initialized. */ | |
165d0d5b | 3869 | no_zero_init = CONSTRUCTOR_NO_CLEARING (*valp); |
9c96033c | 3870 | |
58b0f9ce | 3871 | vec_safe_push (ctors, *valp); |
3872 | ||
7963b19d | 3873 | enum tree_code code = TREE_CODE (type); |
9c96033c | 3874 | type = refs->pop(); |
7963b19d | 3875 | tree index = refs->pop(); |
9c96033c | 3876 | |
9c96033c | 3877 | constructor_elt *cep = NULL; |
7963b19d | 3878 | if (code == ARRAY_TYPE) |
3879 | { | |
3880 | HOST_WIDE_INT i | |
3881 | = find_array_ctor_elt (*valp, index, /*insert*/true); | |
3882 | gcc_assert (i >= 0); | |
3883 | cep = CONSTRUCTOR_ELT (*valp, i); | |
3884 | gcc_assert (TREE_CODE (cep->index) != RANGE_EXPR); | |
3885 | } | |
3886 | else | |
3887 | { | |
3888 | gcc_assert (TREE_CODE (index) == FIELD_DECL); | |
13ee2de7 | 3889 | |
3890 | /* We must keep the CONSTRUCTOR's ELTS in FIELD order. | |
3891 | Usually we meet initializers in that order, but it is | |
3892 | possible for base types to be placed not in program | |
3893 | order. */ | |
3894 | tree fields = TYPE_FIELDS (DECL_CONTEXT (index)); | |
3895 | unsigned HOST_WIDE_INT idx; | |
3896 | ||
ef782365 | 3897 | if (code == UNION_TYPE && CONSTRUCTOR_NELTS (*valp) |
3898 | && CONSTRUCTOR_ELT (*valp, 0)->index != index) | |
b47245f1 | 3899 | { |
3900 | if (cxx_dialect < cxx2a) | |
3901 | { | |
3902 | if (!ctx->quiet) | |
3903 | error_at (cp_expr_loc_or_loc (t, input_location), | |
3904 | "change of the active member of a union " | |
3905 | "from %qD to %qD", | |
3906 | CONSTRUCTOR_ELT (*valp, 0)->index, | |
3907 | index); | |
3908 | *non_constant_p = true; | |
3909 | } | |
3910 | /* Changing active member. */ | |
3911 | vec_safe_truncate (CONSTRUCTOR_ELTS (*valp), 0); | |
a165fd90 | 3912 | no_zero_init = true; |
b47245f1 | 3913 | } |
ef782365 | 3914 | |
13ee2de7 | 3915 | for (idx = 0; |
7963b19d | 3916 | vec_safe_iterate (CONSTRUCTOR_ELTS (*valp), idx, &cep); |
13ee2de7 | 3917 | idx++, fields = DECL_CHAIN (fields)) |
7963b19d | 3918 | { |
13ee2de7 | 3919 | if (index == cep->index) |
3920 | goto found; | |
3921 | ||
3922 | /* The field we're initializing must be on the field | |
3923 | list. Look to see if it is present before the | |
3924 | field the current ELT initializes. */ | |
3925 | for (; fields != cep->index; fields = DECL_CHAIN (fields)) | |
3926 | if (index == fields) | |
3927 | goto insert; | |
7963b19d | 3928 | } |
13ee2de7 | 3929 | |
3930 | /* We fell off the end of the CONSTRUCTOR, so insert a new | |
3931 | entry at the end. */ | |
3932 | insert: | |
3933 | { | |
3934 | constructor_elt ce = { index, NULL_TREE }; | |
3935 | ||
3936 | vec_safe_insert (CONSTRUCTOR_ELTS (*valp), idx, ce); | |
3937 | cep = CONSTRUCTOR_ELT (*valp, idx); | |
3938 | } | |
3939 | found:; | |
7963b19d | 3940 | } |
9c96033c | 3941 | valp = &cep->value; |
3942 | } | |
9c96033c | 3943 | |
6aaacaf1 | 3944 | if (!preeval) |
9c96033c | 3945 | { |
3946 | /* Create a new CONSTRUCTOR in case evaluation of the initializer | |
3947 | wants to modify it. */ | |
469dc5a6 | 3948 | if (*valp == NULL_TREE) |
6cded085 | 3949 | { |
6993e708 | 3950 | *valp = build_constructor (type, NULL); |
165d0d5b | 3951 | CONSTRUCTOR_NO_CLEARING (*valp) = no_zero_init; |
6cded085 | 3952 | } |
6993e708 | 3953 | new_ctx.ctor = *valp; |
9c96033c | 3954 | new_ctx.object = target; |
6aaacaf1 | 3955 | init = cxx_eval_constant_expression (&new_ctx, init, false, |
3956 | non_constant_p, overflow_p); | |
3957 | if (target == object) | |
3958 | /* The hash table might have moved since the get earlier. */ | |
3959 | valp = ctx->values->get (object); | |
9c96033c | 3960 | } |
3961 | ||
7b9f713d | 3962 | /* Don't share a CONSTRUCTOR that might be changed later. */ |
e283bb4f | 3963 | init = unshare_constructor (init); |
5579a199 | 3964 | |
6aaacaf1 | 3965 | if (*valp && TREE_CODE (*valp) == CONSTRUCTOR |
3966 | && TREE_CODE (init) == CONSTRUCTOR) | |
469dc5a6 | 3967 | { |
5579a199 | 3968 | /* An outer ctx->ctor might be pointing to *valp, so replace |
3969 | its contents. */ | |
3970 | CONSTRUCTOR_ELTS (*valp) = CONSTRUCTOR_ELTS (init); | |
3971 | TREE_CONSTANT (*valp) = TREE_CONSTANT (init); | |
3972 | TREE_SIDE_EFFECTS (*valp) = TREE_SIDE_EFFECTS (init); | |
165d0d5b | 3973 | CONSTRUCTOR_NO_CLEARING (*valp) |
3974 | = CONSTRUCTOR_NO_CLEARING (init); | |
469dc5a6 | 3975 | } |
9c96033c | 3976 | else |
5579a199 | 3977 | *valp = init; |
58b0f9ce | 3978 | |
5579a199 | 3979 | /* Update TREE_CONSTANT and TREE_SIDE_EFFECTS on enclosing |
3980 | CONSTRUCTORs, if any. */ | |
3981 | tree elt; | |
3982 | unsigned i; | |
3983 | bool c = TREE_CONSTANT (init); | |
3984 | bool s = TREE_SIDE_EFFECTS (init); | |
3985 | if (!c || s) | |
02fafda8 | 3986 | FOR_EACH_VEC_ELT (*ctors, i, elt) |
5579a199 | 3987 | { |
3988 | if (!c) | |
3989 | TREE_CONSTANT (elt) = false; | |
3990 | if (s) | |
3991 | TREE_SIDE_EFFECTS (elt) = true; | |
3992 | } | |
9c96033c | 3993 | |
3994 | if (*non_constant_p) | |
3995 | return t; | |
1227ba74 | 3996 | else if (lval) |
9c96033c | 3997 | return target; |
3998 | else | |
dfac7dd2 | 3999 | return init; |
9c96033c | 4000 | } |
4001 | ||
4002 | /* Evaluate a ++ or -- expression. */ | |
4003 | ||
4004 | static tree | |
4005 | cxx_eval_increment_expression (const constexpr_ctx *ctx, tree t, | |
1227ba74 | 4006 | bool lval, |
9c96033c | 4007 | bool *non_constant_p, bool *overflow_p) |
4008 | { | |
4009 | enum tree_code code = TREE_CODE (t); | |
4010 | tree type = TREE_TYPE (t); | |
4011 | tree op = TREE_OPERAND (t, 0); | |
4012 | tree offset = TREE_OPERAND (t, 1); | |
4013 | gcc_assert (TREE_CONSTANT (offset)); | |
4014 | ||
4015 | /* The operand as an lvalue. */ | |
f83e6885 | 4016 | op = cxx_eval_constant_expression (ctx, op, true, |
b2a43197 | 4017 | non_constant_p, overflow_p); |
9c96033c | 4018 | |
4019 | /* The operand as an rvalue. */ | |
c017458d | 4020 | tree val |
4021 | = cxx_eval_constant_expression (ctx, op, false, | |
4022 | non_constant_p, overflow_p); | |
35f2c28f | 4023 | /* Don't VERIFY_CONSTANT if this might be dealing with a pointer to |
4024 | a local array in a constexpr function. */ | |
d03fa520 | 4025 | bool ptr = INDIRECT_TYPE_P (TREE_TYPE (val)); |
35f2c28f | 4026 | if (!ptr) |
4027 | VERIFY_CONSTANT (val); | |
9c96033c | 4028 | |
4029 | /* The modified value. */ | |
4030 | bool inc = (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR); | |
c8a8f7ad | 4031 | tree mod; |
d03fa520 | 4032 | if (INDIRECT_TYPE_P (type)) |
c8a8f7ad | 4033 | { |
4034 | /* The middle end requires pointers to use POINTER_PLUS_EXPR. */ | |
4035 | offset = convert_to_ptrofftype (offset); | |
4036 | if (!inc) | |
4037 | offset = fold_build1 (NEGATE_EXPR, TREE_TYPE (offset), offset); | |
4038 | mod = fold_build2 (POINTER_PLUS_EXPR, type, val, offset); | |
4039 | } | |
4040 | else | |
4041 | mod = fold_build2 (inc ? PLUS_EXPR : MINUS_EXPR, type, val, offset); | |
35f2c28f | 4042 | if (!ptr) |
4043 | VERIFY_CONSTANT (mod); | |
9c96033c | 4044 | |
4045 | /* Storing the modified value. */ | |
4046 | tree store = build2 (MODIFY_EXPR, type, op, mod); | |
f83e6885 | 4047 | cxx_eval_constant_expression (ctx, store, |
b2a43197 | 4048 | true, non_constant_p, overflow_p); |
8a9112cd | 4049 | ggc_free (store); |
9c96033c | 4050 | |
4051 | /* And the value of the expression. */ | |
4052 | if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR) | |
4053 | { | |
4054 | /* Prefix ops are lvalues. */ | |
1227ba74 | 4055 | if (lval) |
9c96033c | 4056 | return op; |
4057 | else | |
4058 | /* But we optimize when the caller wants an rvalue. */ | |
4059 | return mod; | |
4060 | } | |
4061 | else | |
4062 | /* Postfix ops are rvalues. */ | |
4063 | return val; | |
4064 | } | |
4065 | ||
00f21715 | 4066 | /* Predicates for the meaning of *jump_target. */ |
4067 | ||
4068 | static bool | |
4069 | returns (tree *jump_target) | |
4070 | { | |
4071 | return *jump_target | |
d29e4e8c | 4072 | && (TREE_CODE (*jump_target) == RETURN_EXPR |
4073 | || (TREE_CODE (*jump_target) == LABEL_DECL | |
4074 | && LABEL_DECL_CDTOR (*jump_target))); | |
00f21715 | 4075 | } |
4076 | ||
4077 | static bool | |
4078 | breaks (tree *jump_target) | |
4079 | { | |
4080 | return *jump_target | |
cf03ba19 | 4081 | && ((TREE_CODE (*jump_target) == LABEL_DECL |
4082 | && LABEL_DECL_BREAK (*jump_target)) | |
32fee334 | 4083 | || TREE_CODE (*jump_target) == BREAK_STMT |
cf03ba19 | 4084 | || TREE_CODE (*jump_target) == EXIT_EXPR); |
00f21715 | 4085 | } |
4086 | ||
4087 | static bool | |
4088 | continues (tree *jump_target) | |
4089 | { | |
4090 | return *jump_target | |
32fee334 | 4091 | && ((TREE_CODE (*jump_target) == LABEL_DECL |
4092 | && LABEL_DECL_CONTINUE (*jump_target)) | |
4093 | || TREE_CODE (*jump_target) == CONTINUE_STMT); | |
4094 | ||
00f21715 | 4095 | } |
4096 | ||
4097 | static bool | |
4098 | switches (tree *jump_target) | |
4099 | { | |
4100 | return *jump_target | |
4101 | && TREE_CODE (*jump_target) == INTEGER_CST; | |
4102 | } | |
4103 | ||
4104 | /* Subroutine of cxx_eval_statement_list. Determine whether the statement | |
2a2770c6 | 4105 | STMT matches *jump_target. If we're looking for a case label and we see |
4106 | the default label, note it in ctx->css_state. */ | |
00f21715 | 4107 | |
4108 | static bool | |
2a2770c6 | 4109 | label_matches (const constexpr_ctx *ctx, tree *jump_target, tree stmt) |
00f21715 | 4110 | { |
00f21715 | 4111 | switch (TREE_CODE (*jump_target)) |
4112 | { | |
4113 | case LABEL_DECL: | |
4114 | if (TREE_CODE (stmt) == LABEL_EXPR | |
4115 | && LABEL_EXPR_LABEL (stmt) == *jump_target) | |
4116 | return true; | |
4117 | break; | |
4118 | ||
4119 | case INTEGER_CST: | |
4120 | if (TREE_CODE (stmt) == CASE_LABEL_EXPR) | |
4121 | { | |
2a2770c6 | 4122 | gcc_assert (ctx->css_state != NULL); |
00f21715 | 4123 | if (!CASE_LOW (stmt)) |
2a2770c6 | 4124 | { |
4125 | /* default: should appear just once in a SWITCH_EXPR | |
4126 | body (excluding nested SWITCH_EXPR). */ | |
4127 | gcc_assert (*ctx->css_state != css_default_seen); | |
4128 | /* When evaluating SWITCH_EXPR body for the second time, | |
4129 | return true for the default: label. */ | |
4130 | if (*ctx->css_state == css_default_processing) | |
4131 | return true; | |
4132 | *ctx->css_state = css_default_seen; | |
4133 | } | |
83c375ba | 4134 | else if (CASE_HIGH (stmt)) |
4135 | { | |
4136 | if (tree_int_cst_le (CASE_LOW (stmt), *jump_target) | |
4137 | && tree_int_cst_le (*jump_target, CASE_HIGH (stmt))) | |
4138 | return true; | |
4139 | } | |
00f21715 | 4140 | else if (tree_int_cst_equal (*jump_target, CASE_LOW (stmt))) |
4141 | return true; | |
4142 | } | |
4143 | break; | |
4144 | ||
02d7a132 | 4145 | case BREAK_STMT: |
4146 | case CONTINUE_STMT: | |
4147 | /* These two are handled directly in cxx_eval_loop_expr by testing | |
4148 | breaks (jump_target) or continues (jump_target). */ | |
4149 | break; | |
4150 | ||
00f21715 | 4151 | default: |
4152 | gcc_unreachable (); | |
4153 | } | |
4154 | return false; | |
4155 | } | |
4156 | ||
4157 | /* Evaluate a STATEMENT_LIST for side-effects. Handles various jump | |
4158 | semantics, for switch, break, continue, and return. */ | |
4159 | ||
4160 | static tree | |
4161 | cxx_eval_statement_list (const constexpr_ctx *ctx, tree t, | |
00f21715 | 4162 | bool *non_constant_p, bool *overflow_p, |
4163 | tree *jump_target) | |
4164 | { | |
4165 | tree_stmt_iterator i; | |
da7981e0 | 4166 | tree local_target; |
efea7c64 | 4167 | /* In a statement-expression we want to return the last value. |
4168 | For empty statement expression return void_node. */ | |
4169 | tree r = void_node; | |
da7981e0 | 4170 | if (!jump_target) |
4171 | { | |
4172 | local_target = NULL_TREE; | |
4173 | jump_target = &local_target; | |
4174 | } | |
00f21715 | 4175 | for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i)) |
4176 | { | |
00f21715 | 4177 | tree stmt = tsi_stmt (i); |
ba0f90e4 | 4178 | /* We've found a continue, so skip everything until we reach |
4179 | the label its jumping to. */ | |
4180 | if (continues (jump_target)) | |
4181 | { | |
4182 | if (label_matches (ctx, jump_target, stmt)) | |
4183 | /* Found it. */ | |
4184 | *jump_target = NULL_TREE; | |
4185 | else | |
4186 | continue; | |
4187 | } | |
442c4003 | 4188 | if (TREE_CODE (stmt) == DEBUG_BEGIN_STMT) |
4189 | continue; | |
da7981e0 | 4190 | r = cxx_eval_constant_expression (ctx, stmt, false, |
4191 | non_constant_p, overflow_p, | |
4192 | jump_target); | |
00f21715 | 4193 | if (*non_constant_p) |
4194 | break; | |
4195 | if (returns (jump_target) || breaks (jump_target)) | |
4196 | break; | |
4197 | } | |
071a07da | 4198 | if (*jump_target && jump_target == &local_target) |
4199 | { | |
4200 | /* We aren't communicating the jump to our caller, so give up. We don't | |
4201 | need to support evaluation of jumps out of statement-exprs. */ | |
4202 | if (!ctx->quiet) | |
4203 | error_at (cp_expr_loc_or_loc (r, input_location), | |
4204 | "statement is not a constant expression"); | |
4205 | *non_constant_p = true; | |
4206 | } | |
da7981e0 | 4207 | return r; |
00f21715 | 4208 | } |
4209 | ||
4210 | /* Evaluate a LOOP_EXPR for side-effects. Handles break and return | |
4211 | semantics; continue semantics are covered by cxx_eval_statement_list. */ | |
4212 | ||
4213 | static tree | |
4214 | cxx_eval_loop_expr (const constexpr_ctx *ctx, tree t, | |
00f21715 | 4215 | bool *non_constant_p, bool *overflow_p, |
4216 | tree *jump_target) | |
4217 | { | |
2631cb67 | 4218 | constexpr_ctx new_ctx = *ctx; |
4219 | ||
02d7a132 | 4220 | tree body, cond = NULL_TREE, expr = NULL_TREE; |
21483ab7 | 4221 | int count = 0; |
02d7a132 | 4222 | switch (TREE_CODE (t)) |
4223 | { | |
4224 | case LOOP_EXPR: | |
4225 | body = LOOP_EXPR_BODY (t); | |
4226 | break; | |
4227 | case DO_STMT: | |
4228 | body = DO_BODY (t); | |
4229 | cond = DO_COND (t); | |
4230 | break; | |
4231 | case WHILE_STMT: | |
4232 | body = WHILE_BODY (t); | |
4233 | cond = WHILE_COND (t); | |
4234 | count = -1; | |
4235 | break; | |
4236 | case FOR_STMT: | |
4237 | if (FOR_INIT_STMT (t)) | |
4238 | cxx_eval_constant_expression (ctx, FOR_INIT_STMT (t), /*lval*/false, | |
4239 | non_constant_p, overflow_p, jump_target); | |
4240 | if (*non_constant_p) | |
4241 | return NULL_TREE; | |
4242 | body = FOR_BODY (t); | |
4243 | cond = FOR_COND (t); | |
4244 | expr = FOR_EXPR (t); | |
4245 | count = -1; | |
4246 | break; | |
4247 | default: | |
4248 | gcc_unreachable (); | |
4249 | } | |
d0782a7e | 4250 | auto_vec<tree, 10> save_exprs; |
02d7a132 | 4251 | new_ctx.save_exprs = &save_exprs; |
5370eb8d | 4252 | do |
00f21715 | 4253 | { |
02d7a132 | 4254 | if (count != -1) |
4255 | { | |
4256 | if (body) | |
4257 | cxx_eval_constant_expression (&new_ctx, body, /*lval*/false, | |
4258 | non_constant_p, overflow_p, | |
4259 | jump_target); | |
4260 | if (breaks (jump_target)) | |
4261 | { | |
4262 | *jump_target = NULL_TREE; | |
4263 | break; | |
4264 | } | |
2631cb67 | 4265 | |
02d7a132 | 4266 | if (TREE_CODE (t) != LOOP_EXPR && continues (jump_target)) |
4267 | *jump_target = NULL_TREE; | |
4268 | ||
4269 | if (expr) | |
4270 | cxx_eval_constant_expression (&new_ctx, expr, /*lval*/false, | |
4271 | non_constant_p, overflow_p, | |
4272 | jump_target); | |
4273 | } | |
4274 | ||
4275 | if (cond) | |
4276 | { | |
4277 | tree res | |
4278 | = cxx_eval_constant_expression (&new_ctx, cond, /*lval*/false, | |
4279 | non_constant_p, overflow_p, | |
4280 | jump_target); | |
4281 | if (res) | |
4282 | { | |
4283 | if (verify_constant (res, ctx->quiet, non_constant_p, | |
4284 | overflow_p)) | |
4285 | break; | |
4286 | if (integer_zerop (res)) | |
4287 | break; | |
4288 | } | |
4289 | else | |
4290 | gcc_assert (*jump_target); | |
4291 | } | |
2631cb67 | 4292 | |
4293 | /* Forget saved values of SAVE_EXPRs. */ | |
d0782a7e | 4294 | unsigned int i; |
4295 | tree save_expr; | |
4296 | FOR_EACH_VEC_ELT (save_exprs, i, save_expr) | |
4297 | new_ctx.values->remove (save_expr); | |
4298 | save_exprs.truncate (0); | |
02d7a132 | 4299 | |
21483ab7 | 4300 | if (++count >= constexpr_loop_limit) |
4301 | { | |
4302 | if (!ctx->quiet) | |
d3a3cfb8 | 4303 | error_at (cp_expr_loc_or_loc (t, input_location), |
5967b28b | 4304 | "%<constexpr%> loop iteration count exceeds limit of %d " |
2f6d557f | 4305 | "(use %<-fconstexpr-loop-limit=%> to increase the limit)", |
21483ab7 | 4306 | constexpr_loop_limit); |
4307 | *non_constant_p = true; | |
4308 | break; | |
4309 | } | |
00f21715 | 4310 | } |
2a2770c6 | 4311 | while (!returns (jump_target) |
4312 | && !breaks (jump_target) | |
02d7a132 | 4313 | && !continues (jump_target) |
4314 | && (!switches (jump_target) || count == 0) | |
2a2770c6 | 4315 | && !*non_constant_p); |
5370eb8d | 4316 | |
02d7a132 | 4317 | /* Forget saved values of SAVE_EXPRs. */ |
d0782a7e | 4318 | unsigned int i; |
4319 | tree save_expr; | |
4320 | FOR_EACH_VEC_ELT (save_exprs, i, save_expr) | |
4321 | new_ctx.values->remove (save_expr); | |
2631cb67 | 4322 | |
00f21715 | 4323 | return NULL_TREE; |
4324 | } | |
4325 | ||
4326 | /* Evaluate a SWITCH_EXPR for side-effects. Handles switch and break jump | |
4327 | semantics. */ | |
4328 | ||
4329 | static tree | |
4330 | cxx_eval_switch_expr (const constexpr_ctx *ctx, tree t, | |
00f21715 | 4331 | bool *non_constant_p, bool *overflow_p, |
4332 | tree *jump_target) | |
4333 | { | |
02d7a132 | 4334 | tree cond |
4335 | = TREE_CODE (t) == SWITCH_STMT ? SWITCH_STMT_COND (t) : SWITCH_COND (t); | |
f83e6885 | 4336 | cond = cxx_eval_constant_expression (ctx, cond, false, |
b2a43197 | 4337 | non_constant_p, overflow_p); |
00f21715 | 4338 | VERIFY_CONSTANT (cond); |
4339 | *jump_target = cond; | |
4340 | ||
02d7a132 | 4341 | tree body |
4342 | = TREE_CODE (t) == SWITCH_STMT ? SWITCH_STMT_BODY (t) : SWITCH_BODY (t); | |
2a2770c6 | 4343 | constexpr_ctx new_ctx = *ctx; |
4344 | constexpr_switch_state css = css_default_not_seen; | |
4345 | new_ctx.css_state = &css; | |
4346 | cxx_eval_constant_expression (&new_ctx, body, false, | |
4347 | non_constant_p, overflow_p, jump_target); | |
4348 | if (switches (jump_target) && css == css_default_seen) | |
4349 | { | |
4350 | /* If the SWITCH_EXPR body has default: label, process it once again, | |
4351 | this time instructing label_matches to return true for default: | |
4352 | label on switches (jump_target). */ | |
4353 | css = css_default_processing; | |
4354 | cxx_eval_constant_expression (&new_ctx, body, false, | |
4355 | non_constant_p, overflow_p, jump_target); | |
4356 | } | |
00f21715 | 4357 | if (breaks (jump_target) || switches (jump_target)) |
4358 | *jump_target = NULL_TREE; | |
4359 | return NULL_TREE; | |
4360 | } | |
4361 | ||
85de9604 | 4362 | /* Find the object of TYPE under initialization in CTX. */ |
4363 | ||
4364 | static tree | |
4365 | lookup_placeholder (const constexpr_ctx *ctx, bool lval, tree type) | |
4366 | { | |
def8e41f | 4367 | if (!ctx) |
85de9604 | 4368 | return NULL_TREE; |
4369 | ||
4370 | /* We could use ctx->object unconditionally, but using ctx->ctor when we | |
4371 | can is a minor optimization. */ | |
def8e41f | 4372 | if (!lval && ctx->ctor && same_type_p (TREE_TYPE (ctx->ctor), type)) |
85de9604 | 4373 | return ctx->ctor; |
4374 | ||
def8e41f | 4375 | if (!ctx->object) |
4376 | return NULL_TREE; | |
4377 | ||
85de9604 | 4378 | /* Since an object cannot have a field of its own type, we can search outward |
4379 | from ctx->object to find the unique containing object of TYPE. */ | |
4380 | tree ob = ctx->object; | |
4381 | while (ob) | |
4382 | { | |
4383 | if (same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (ob), type)) | |
4384 | break; | |
4385 | if (handled_component_p (ob)) | |
4386 | ob = TREE_OPERAND (ob, 0); | |
4387 | else | |
4388 | ob = NULL_TREE; | |
4389 | } | |
4390 | ||
4391 | return ob; | |
4392 | } | |
4393 | ||
09b42213 | 4394 | /* Attempt to reduce the expression T to a constant value. |
4395 | On failure, issue diagnostic and return error_mark_node. */ | |
4396 | /* FIXME unify with c_fully_fold */ | |
9c96033c | 4397 | /* FIXME overflow_p is too global */ |
09b42213 | 4398 | |
4399 | static tree | |
cf72f34d | 4400 | cxx_eval_constant_expression (const constexpr_ctx *ctx, tree t, |
1227ba74 | 4401 | bool lval, |
00f21715 | 4402 | bool *non_constant_p, bool *overflow_p, |
32fee334 | 4403 | tree *jump_target /* = NULL */) |
09b42213 | 4404 | { |
2a2770c6 | 4405 | if (jump_target && *jump_target) |
4406 | { | |
4407 | /* If we are jumping, ignore all statements/expressions except those | |
4408 | that could have LABEL_EXPR or CASE_LABEL_EXPR in their bodies. */ | |
4409 | switch (TREE_CODE (t)) | |
4410 | { | |
4411 | case BIND_EXPR: | |
4412 | case STATEMENT_LIST: | |
4413 | case LOOP_EXPR: | |
4414 | case COND_EXPR: | |
02d7a132 | 4415 | case IF_STMT: |
4416 | case DO_STMT: | |
4417 | case WHILE_STMT: | |
4418 | case FOR_STMT: | |
2a2770c6 | 4419 | break; |
4420 | case LABEL_EXPR: | |
4421 | case CASE_LABEL_EXPR: | |
4422 | if (label_matches (ctx, jump_target, t)) | |
4423 | /* Found it. */ | |
4424 | *jump_target = NULL_TREE; | |
4425 | return NULL_TREE; | |
4426 | default: | |
4427 | return NULL_TREE; | |
4428 | } | |
4429 | } | |
32fee334 | 4430 | if (error_operand_p (t)) |
09b42213 | 4431 | { |
4432 | *non_constant_p = true; | |
4433 | return t; | |
4434 | } | |
5f93e2e7 | 4435 | |
4436 | STRIP_ANY_LOCATION_WRAPPER (t); | |
4437 | ||
09b42213 | 4438 | if (CONSTANT_CLASS_P (t)) |
4439 | { | |
c4fa85c9 | 4440 | if (TREE_OVERFLOW (t)) |
4441 | { | |
4442 | if (!ctx->quiet) | |
4443 | permerror (input_location, "overflow in constant expression"); | |
4444 | if (!flag_permissive || ctx->quiet) | |
4445 | *overflow_p = true; | |
4446 | } | |
cb768824 | 4447 | |
4448 | if (TREE_CODE (t) == INTEGER_CST | |
90ad495b | 4449 | && TYPE_PTR_P (TREE_TYPE (t)) |
cb768824 | 4450 | && !integer_zerop (t)) |
4451 | { | |
4452 | if (!ctx->quiet) | |
4453 | error ("value %qE of type %qT is not a constant expression", | |
4454 | t, TREE_TYPE (t)); | |
4455 | *non_constant_p = true; | |
4456 | } | |
4457 | ||
09b42213 | 4458 | return t; |
4459 | } | |
09b42213 | 4460 | |
84f13b2f | 4461 | /* Avoid excessively long constexpr evaluations. */ |
5f93e2e7 | 4462 | if (++*ctx->constexpr_ops_count >= constexpr_ops_limit) |
84f13b2f | 4463 | { |
4464 | if (!ctx->quiet) | |
4465 | error_at (cp_expr_loc_or_loc (t, input_location), | |
4466 | "%<constexpr%> evaluation operation count exceeds limit of " | |
85b9be9b | 4467 | "%wd (use %<-fconstexpr-ops-limit=%> to increase the limit)", |
84f13b2f | 4468 | constexpr_ops_limit); |
4469 | *ctx->constexpr_ops_count = INTTYPE_MINIMUM (HOST_WIDE_INT); | |
4470 | *non_constant_p = true; | |
4471 | return t; | |
4472 | } | |
4473 | ||
5f93e2e7 | 4474 | constexpr_ctx new_ctx; |
4475 | tree r = t; | |
4476 | ||
cb768824 | 4477 | tree_code tcode = TREE_CODE (t); |
4478 | switch (tcode) | |
09b42213 | 4479 | { |
9c96033c | 4480 | case RESULT_DECL: |
1227ba74 | 4481 | if (lval) |
9c96033c | 4482 | return t; |
4483 | /* We ask for an rvalue for the RESULT_DECL when indirecting | |
92a9c89e | 4484 | through an invisible reference, or in named return value |
4485 | optimization. */ | |
8ea8d065 | 4486 | if (tree *p = ctx->values->get (t)) |
4487 | return *p; | |
4488 | else | |
4489 | { | |
4490 | if (!ctx->quiet) | |
4491 | error ("%qE is not a constant expression", t); | |
4492 | *non_constant_p = true; | |
4493 | } | |
4494 | break; | |
9c96033c | 4495 | |
09b42213 | 4496 | case VAR_DECL: |
9c8aeb66 | 4497 | if (DECL_HAS_VALUE_EXPR_P (t)) |
460e6a8c | 4498 | { |
4499 | if (is_normal_capture_proxy (t) | |
4500 | && current_function_decl == DECL_CONTEXT (t)) | |
4501 | { | |
4502 | /* Function parms aren't constexpr within the function | |
4503 | definition, so don't try to look at the closure. But if the | |
4504 | captured variable is constant, try to evaluate it directly. */ | |
4505 | r = DECL_CAPTURED_VARIABLE (t); | |
4506 | tree type = TREE_TYPE (t); | |
4507 | if (TYPE_REF_P (type) != TYPE_REF_P (TREE_TYPE (r))) | |
4508 | { | |
4509 | /* Adjust r to match the reference-ness of t. */ | |
4510 | if (TYPE_REF_P (type)) | |
4511 | r = build_address (r); | |
4512 | else | |
4513 | r = convert_from_reference (r); | |
4514 | } | |
4515 | } | |
4516 | else | |
4517 | r = DECL_VALUE_EXPR (t); | |
4518 | return cxx_eval_constant_expression (ctx, r, lval, non_constant_p, | |
4519 | overflow_p); | |
4520 | } | |
e3533433 | 4521 | /* fall through */ |
8b2b2f24 | 4522 | case CONST_DECL: |
4523 | /* We used to not check lval for CONST_DECL, but darwin.c uses | |
4524 | CONST_DECL for aggregate constants. */ | |
1227ba74 | 4525 | if (lval) |
09b42213 | 4526 | return t; |
594cc00c | 4527 | if (COMPLETE_TYPE_P (TREE_TYPE (t)) |
cd5a9ed1 | 4528 | && is_really_empty_class (TREE_TYPE (t), /*ignore_vptr*/false)) |
c7282bf2 | 4529 | { |
4530 | /* If the class is empty, we aren't actually loading anything. */ | |
4531 | r = build_constructor (TREE_TYPE (t), NULL); | |
4532 | TREE_CONSTANT (r) = true; | |
4533 | } | |
4534 | else if (ctx->strict) | |
2055d27a | 4535 | r = decl_really_constant_value (t); |
4536 | else | |
4537 | r = decl_constant_value (t); | |
09b42213 | 4538 | if (TREE_CODE (r) == TARGET_EXPR |
4539 | && TREE_CODE (TARGET_EXPR_INITIAL (r)) == CONSTRUCTOR) | |
4540 | r = TARGET_EXPR_INITIAL (r); | |
f4ae4202 | 4541 | if (VAR_P (r)) |
cf72f34d | 4542 | if (tree *p = ctx->values->get (r)) |
a143e277 | 4543 | if (*p != NULL_TREE) |
4544 | r = *p; | |
09b42213 | 4545 | if (DECL_P (r)) |
4546 | { | |
f83e6885 | 4547 | if (!ctx->quiet) |
09b42213 | 4548 | non_const_var_error (r); |
4549 | *non_constant_p = true; | |
4550 | } | |
4551 | break; | |
4552 | ||
90567983 | 4553 | case DEBUG_BEGIN_STMT: |
4554 | /* ??? It might be nice to retain this information somehow, so | |
4555 | as to be able to step into a constexpr function call. */ | |
4556 | /* Fall through. */ | |
4557 | ||
09b42213 | 4558 | case FUNCTION_DECL: |
4559 | case TEMPLATE_DECL: | |
4560 | case LABEL_DECL: | |
00f21715 | 4561 | case LABEL_EXPR: |
4562 | case CASE_LABEL_EXPR: | |
2a2770c6 | 4563 | case PREDICT_EXPR: |
09b42213 | 4564 | return t; |
4565 | ||
4566 | case PARM_DECL: | |
90ad495b | 4567 | if (lval && !TYPE_REF_P (TREE_TYPE (t))) |
9c96033c | 4568 | /* glvalue use. */; |
4569 | else if (tree *p = ctx->values->get (r)) | |
4570 | r = *p; | |
1227ba74 | 4571 | else if (lval) |
09b42213 | 4572 | /* Defer in case this is only used for its type. */; |
90ad495b | 4573 | else if (TYPE_REF_P (TREE_TYPE (t))) |
1eb418cc | 4574 | /* Defer, there's no lvalue->rvalue conversion. */; |
53d2f3de | 4575 | else if (COMPLETE_TYPE_P (TREE_TYPE (t)) |
cd5a9ed1 | 4576 | && is_really_empty_class (TREE_TYPE (t), /*ignore_vptr*/false)) |
a6613de7 | 4577 | { |
4578 | /* If the class is empty, we aren't actually loading anything. */ | |
4579 | r = build_constructor (TREE_TYPE (t), NULL); | |
4580 | TREE_CONSTANT (r) = true; | |
4581 | } | |
09b42213 | 4582 | else |
4583 | { | |
f83e6885 | 4584 | if (!ctx->quiet) |
09b42213 | 4585 | error ("%qE is not a constant expression", t); |
4586 | *non_constant_p = true; | |
4587 | } | |
4588 | break; | |
4589 | ||
4590 | case CALL_EXPR: | |
4591 | case AGGR_INIT_EXPR: | |
1227ba74 | 4592 | r = cxx_eval_call_expression (ctx, t, lval, |
09b42213 | 4593 | non_constant_p, overflow_p); |
4594 | break; | |
4595 | ||
9c96033c | 4596 | case DECL_EXPR: |
4597 | { | |
4598 | r = DECL_EXPR_DECL (t); | |
02d7a132 | 4599 | if (TREE_CODE (r) == USING_DECL) |
4600 | { | |
4601 | r = void_node; | |
4602 | break; | |
4603 | } | |
9c96033c | 4604 | if (AGGREGATE_TYPE_P (TREE_TYPE (r)) |
4605 | || VECTOR_TYPE_P (TREE_TYPE (r))) | |
4606 | { | |
4607 | new_ctx = *ctx; | |
4608 | new_ctx.object = r; | |
4609 | new_ctx.ctor = build_constructor (TREE_TYPE (r), NULL); | |
165d0d5b | 4610 | CONSTRUCTOR_NO_CLEARING (new_ctx.ctor) = true; |
9c96033c | 4611 | new_ctx.values->put (r, new_ctx.ctor); |
4612 | ctx = &new_ctx; | |
4613 | } | |
4614 | ||
4615 | if (tree init = DECL_INITIAL (r)) | |
4616 | { | |
4617 | init = cxx_eval_constant_expression (ctx, init, | |
f83e6885 | 4618 | false, |
b2a43197 | 4619 | non_constant_p, overflow_p); |
5898f0d7 | 4620 | /* Don't share a CONSTRUCTOR that might be changed. */ |
e283bb4f | 4621 | init = unshare_constructor (init); |
9c96033c | 4622 | ctx->values->put (r, init); |
4623 | } | |
4624 | else if (ctx == &new_ctx) | |
4625 | /* We gave it a CONSTRUCTOR above. */; | |
4626 | else | |
4627 | ctx->values->put (r, NULL_TREE); | |
4628 | } | |
4629 | break; | |
4630 | ||
09b42213 | 4631 | case TARGET_EXPR: |
4632 | if (!literal_type_p (TREE_TYPE (t))) | |
4633 | { | |
f83e6885 | 4634 | if (!ctx->quiet) |
09b42213 | 4635 | { |
bc35ef65 | 4636 | auto_diagnostic_group d; |
09b42213 | 4637 | error ("temporary of non-literal type %qT in a " |
4638 | "constant expression", TREE_TYPE (t)); | |
4639 | explain_non_literal_class (TREE_TYPE (t)); | |
4640 | } | |
4641 | *non_constant_p = true; | |
4642 | break; | |
4643 | } | |
cf72f34d | 4644 | if ((AGGREGATE_TYPE_P (TREE_TYPE (t)) || VECTOR_TYPE_P (TREE_TYPE (t)))) |
4645 | { | |
4646 | /* We're being expanded without an explicit target, so start | |
4647 | initializing a new object; expansion with an explicit target | |
4648 | strips the TARGET_EXPR before we get here. */ | |
4649 | new_ctx = *ctx; | |
4650 | new_ctx.ctor = build_constructor (TREE_TYPE (t), NULL); | |
165d0d5b | 4651 | CONSTRUCTOR_NO_CLEARING (new_ctx.ctor) = true; |
cf72f34d | 4652 | new_ctx.object = TARGET_EXPR_SLOT (t); |
4653 | ctx->values->put (new_ctx.object, new_ctx.ctor); | |
4654 | ctx = &new_ctx; | |
4655 | } | |
1227ba74 | 4656 | /* Pass false for 'lval' because this indicates |
09b42213 | 4657 | initialization of a temporary. */ |
cf72f34d | 4658 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), |
f83e6885 | 4659 | false, |
b2a43197 | 4660 | non_constant_p, overflow_p); |
09b42213 | 4661 | if (!*non_constant_p) |
4662 | /* Adjust the type of the result to the type of the temporary. */ | |
4663 | r = adjust_temp_type (TREE_TYPE (t), r); | |
1227ba74 | 4664 | if (lval) |
1eb418cc | 4665 | { |
4666 | tree slot = TARGET_EXPR_SLOT (t); | |
e283bb4f | 4667 | r = unshare_constructor (r); |
1eb418cc | 4668 | ctx->values->put (slot, r); |
4669 | return slot; | |
4670 | } | |
09b42213 | 4671 | break; |
4672 | ||
9c96033c | 4673 | case INIT_EXPR: |
9c96033c | 4674 | case MODIFY_EXPR: |
2a2770c6 | 4675 | gcc_assert (jump_target == NULL || *jump_target == NULL_TREE); |
1227ba74 | 4676 | r = cxx_eval_store_expression (ctx, t, lval, |
9c96033c | 4677 | non_constant_p, overflow_p); |
4678 | break; | |
4679 | ||
09b42213 | 4680 | case SCOPE_REF: |
cf72f34d | 4681 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), |
1227ba74 | 4682 | lval, |
b2a43197 | 4683 | non_constant_p, overflow_p); |
09b42213 | 4684 | break; |
4685 | ||
4686 | case RETURN_EXPR: | |
10fb495c | 4687 | if (TREE_OPERAND (t, 0) != NULL_TREE) |
4688 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), | |
4689 | lval, | |
4690 | non_constant_p, overflow_p); | |
02d7a132 | 4691 | /* FALLTHRU */ |
4692 | case BREAK_STMT: | |
4693 | case CONTINUE_STMT: | |
2c572f5f | 4694 | if (jump_target) |
4695 | *jump_target = t; | |
4696 | else | |
4697 | { | |
4698 | /* Can happen with ({ return true; }) && false; passed to | |
4699 | maybe_constant_value. There is nothing to jump over in this | |
4700 | case, and the bug will be diagnosed later. */ | |
4701 | gcc_assert (ctx->quiet); | |
4702 | *non_constant_p = true; | |
4703 | } | |
00f21715 | 4704 | break; |
4705 | ||
e0e672a0 | 4706 | case SAVE_EXPR: |
4707 | /* Avoid evaluating a SAVE_EXPR more than once. */ | |
4708 | if (tree *p = ctx->values->get (t)) | |
4709 | r = *p; | |
4710 | else | |
4711 | { | |
c8f6aeb1 | 4712 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), false, |
e0e672a0 | 4713 | non_constant_p, overflow_p); |
4714 | ctx->values->put (t, r); | |
2631cb67 | 4715 | if (ctx->save_exprs) |
d0782a7e | 4716 | ctx->save_exprs->safe_push (t); |
e0e672a0 | 4717 | } |
4718 | break; | |
4719 | ||
09b42213 | 4720 | case NON_LVALUE_EXPR: |
4721 | case TRY_CATCH_EXPR: | |
7f67d68c | 4722 | case TRY_BLOCK: |
09b42213 | 4723 | case CLEANUP_POINT_EXPR: |
4724 | case MUST_NOT_THROW_EXPR: | |
9c96033c | 4725 | case EXPR_STMT: |
4726 | case EH_SPEC_BLOCK: | |
cf72f34d | 4727 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), |
1227ba74 | 4728 | lval, |
00f21715 | 4729 | non_constant_p, overflow_p, |
4730 | jump_target); | |
09b42213 | 4731 | break; |
4732 | ||
7f67d68c | 4733 | case TRY_FINALLY_EXPR: |
4734 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval, | |
4735 | non_constant_p, overflow_p, | |
4736 | jump_target); | |
4737 | if (!*non_constant_p) | |
4738 | /* Also evaluate the cleanup. */ | |
4739 | cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), true, | |
4740 | non_constant_p, overflow_p, | |
4741 | jump_target); | |
4742 | break; | |
4743 | ||
02d7a132 | 4744 | case CLEANUP_STMT: |
4745 | r = cxx_eval_constant_expression (ctx, CLEANUP_BODY (t), lval, | |
4746 | non_constant_p, overflow_p, | |
4747 | jump_target); | |
4748 | if (!CLEANUP_EH_ONLY (t) && !*non_constant_p) | |
4749 | /* Also evaluate the cleanup. */ | |
4750 | cxx_eval_constant_expression (ctx, CLEANUP_EXPR (t), true, | |
4751 | non_constant_p, overflow_p, | |
4752 | jump_target); | |
4753 | break; | |
4754 | ||
09b42213 | 4755 | /* These differ from cxx_eval_unary_expression in that this doesn't |
4756 | check for a constant operand or result; an address can be | |
4757 | constant without its operand being, and vice versa. */ | |
d2c63826 | 4758 | case MEM_REF: |
09b42213 | 4759 | case INDIRECT_REF: |
1227ba74 | 4760 | r = cxx_eval_indirect_ref (ctx, t, lval, |
09b42213 | 4761 | non_constant_p, overflow_p); |
4762 | break; | |
4763 | ||
4764 | case ADDR_EXPR: | |
4765 | { | |
4766 | tree oldop = TREE_OPERAND (t, 0); | |
cf72f34d | 4767 | tree op = cxx_eval_constant_expression (ctx, oldop, |
1227ba74 | 4768 | /*lval*/true, |
b2a43197 | 4769 | non_constant_p, overflow_p); |
09b42213 | 4770 | /* Don't VERIFY_CONSTANT here. */ |
4771 | if (*non_constant_p) | |
4772 | return t; | |
1eb418cc | 4773 | gcc_checking_assert (TREE_CODE (op) != CONSTRUCTOR); |
09b42213 | 4774 | /* This function does more aggressive folding than fold itself. */ |
4775 | r = build_fold_addr_expr_with_type (op, TREE_TYPE (t)); | |
4776 | if (TREE_CODE (r) == ADDR_EXPR && TREE_OPERAND (r, 0) == oldop) | |
5f93e2e7 | 4777 | { |
4778 | ggc_free (r); | |
4779 | return t; | |
4780 | } | |
09b42213 | 4781 | break; |
4782 | } | |
4783 | ||
4784 | case REALPART_EXPR: | |
4785 | case IMAGPART_EXPR: | |
6fe424c2 | 4786 | if (lval) |
4787 | { | |
4788 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval, | |
4789 | non_constant_p, overflow_p); | |
4790 | if (r == error_mark_node) | |
4791 | ; | |
4792 | else if (r == TREE_OPERAND (t, 0)) | |
4793 | r = t; | |
4794 | else | |
4795 | r = fold_build1 (TREE_CODE (t), TREE_TYPE (t), r); | |
4796 | break; | |
4797 | } | |
4798 | /* FALLTHRU */ | |
09b42213 | 4799 | case CONJ_EXPR: |
4800 | case FIX_TRUNC_EXPR: | |
4801 | case FLOAT_EXPR: | |
4802 | case NEGATE_EXPR: | |
4803 | case ABS_EXPR: | |
19b4138e | 4804 | case ABSU_EXPR: |
09b42213 | 4805 | case BIT_NOT_EXPR: |
4806 | case TRUTH_NOT_EXPR: | |
4807 | case FIXED_CONVERT_EXPR: | |
1227ba74 | 4808 | r = cxx_eval_unary_expression (ctx, t, lval, |
09b42213 | 4809 | non_constant_p, overflow_p); |
4810 | break; | |
4811 | ||
4812 | case SIZEOF_EXPR: | |
518af62d | 4813 | r = fold_sizeof_expr (t); |
4814 | /* In a template, fold_sizeof_expr may merely create a new SIZEOF_EXPR, | |
4815 | which could lead to an infinite recursion. */ | |
4816 | if (TREE_CODE (r) != SIZEOF_EXPR) | |
4817 | r = cxx_eval_constant_expression (ctx, r, lval, | |
4818 | non_constant_p, overflow_p, | |
4819 | jump_target); | |
4820 | else | |
4821 | { | |
4822 | *non_constant_p = true; | |
4823 | gcc_assert (ctx->quiet); | |
4824 | } | |
4825 | ||
09b42213 | 4826 | break; |
4827 | ||
4828 | case COMPOUND_EXPR: | |
4829 | { | |
4830 | /* check_return_expr sometimes wraps a TARGET_EXPR in a | |
4831 | COMPOUND_EXPR; don't get confused. Also handle EMPTY_CLASS_EXPR | |
4832 | introduced by build_call_a. */ | |
4833 | tree op0 = TREE_OPERAND (t, 0); | |
4834 | tree op1 = TREE_OPERAND (t, 1); | |
4835 | STRIP_NOPS (op1); | |
4836 | if ((TREE_CODE (op0) == TARGET_EXPR && op1 == TARGET_EXPR_SLOT (op0)) | |
4837 | || TREE_CODE (op1) == EMPTY_CLASS_EXPR) | |
f83e6885 | 4838 | r = cxx_eval_constant_expression (ctx, op0, |
1227ba74 | 4839 | lval, non_constant_p, overflow_p, |
00f21715 | 4840 | jump_target); |
09b42213 | 4841 | else |
4842 | { | |
4843 | /* Check that the LHS is constant and then discard it. */ | |
f83e6885 | 4844 | cxx_eval_constant_expression (ctx, op0, |
c8f6aeb1 | 4845 | true, non_constant_p, overflow_p, |
00f21715 | 4846 | jump_target); |
cf03ba19 | 4847 | if (*non_constant_p) |
4848 | return t; | |
09b42213 | 4849 | op1 = TREE_OPERAND (t, 1); |
f83e6885 | 4850 | r = cxx_eval_constant_expression (ctx, op1, |
1227ba74 | 4851 | lval, non_constant_p, overflow_p, |
00f21715 | 4852 | jump_target); |
09b42213 | 4853 | } |
4854 | } | |
4855 | break; | |
4856 | ||
4857 | case POINTER_PLUS_EXPR: | |
57e83b58 | 4858 | case POINTER_DIFF_EXPR: |
09b42213 | 4859 | case PLUS_EXPR: |
4860 | case MINUS_EXPR: | |
4861 | case MULT_EXPR: | |
4862 | case TRUNC_DIV_EXPR: | |
4863 | case CEIL_DIV_EXPR: | |
4864 | case FLOOR_DIV_EXPR: | |
4865 | case ROUND_DIV_EXPR: | |
4866 | case TRUNC_MOD_EXPR: | |
4867 | case CEIL_MOD_EXPR: | |
4868 | case ROUND_MOD_EXPR: | |
4869 | case RDIV_EXPR: | |
4870 | case EXACT_DIV_EXPR: | |
4871 | case MIN_EXPR: | |
4872 | case MAX_EXPR: | |
4873 | case LSHIFT_EXPR: | |
4874 | case RSHIFT_EXPR: | |
4875 | case LROTATE_EXPR: | |
4876 | case RROTATE_EXPR: | |
4877 | case BIT_IOR_EXPR: | |
4878 | case BIT_XOR_EXPR: | |
4879 | case BIT_AND_EXPR: | |
4880 | case TRUTH_XOR_EXPR: | |
4881 | case LT_EXPR: | |
4882 | case LE_EXPR: | |
4883 | case GT_EXPR: | |
4884 | case GE_EXPR: | |
4885 | case EQ_EXPR: | |
4886 | case NE_EXPR: | |
4887 | case UNORDERED_EXPR: | |
4888 | case ORDERED_EXPR: | |
4889 | case UNLT_EXPR: | |
4890 | case UNLE_EXPR: | |
4891 | case UNGT_EXPR: | |
4892 | case UNGE_EXPR: | |
4893 | case UNEQ_EXPR: | |
4894 | case LTGT_EXPR: | |
4895 | case RANGE_EXPR: | |
4896 | case COMPLEX_EXPR: | |
1227ba74 | 4897 | r = cxx_eval_binary_expression (ctx, t, lval, |
09b42213 | 4898 | non_constant_p, overflow_p); |
4899 | break; | |
4900 | ||
4901 | /* fold can introduce non-IF versions of these; still treat them as | |
4902 | short-circuiting. */ | |
4903 | case TRUTH_AND_EXPR: | |
4904 | case TRUTH_ANDIF_EXPR: | |
cf72f34d | 4905 | r = cxx_eval_logical_expression (ctx, t, boolean_false_node, |
09b42213 | 4906 | boolean_true_node, |
1227ba74 | 4907 | lval, |
09b42213 | 4908 | non_constant_p, overflow_p); |
4909 | break; | |
4910 | ||
4911 | case TRUTH_OR_EXPR: | |
4912 | case TRUTH_ORIF_EXPR: | |
cf72f34d | 4913 | r = cxx_eval_logical_expression (ctx, t, boolean_true_node, |
09b42213 | 4914 | boolean_false_node, |
1227ba74 | 4915 | lval, |
09b42213 | 4916 | non_constant_p, overflow_p); |
4917 | break; | |
4918 | ||
4919 | case ARRAY_REF: | |
1227ba74 | 4920 | r = cxx_eval_array_reference (ctx, t, lval, |
09b42213 | 4921 | non_constant_p, overflow_p); |
4922 | break; | |
4923 | ||
4924 | case COMPONENT_REF: | |
4925 | if (is_overloaded_fn (t)) | |
4926 | { | |
4927 | /* We can only get here in checking mode via | |
4928 | build_non_dependent_expr, because any expression that | |
4929 | calls or takes the address of the function will have | |
4930 | pulled a FUNCTION_DECL out of the COMPONENT_REF. */ | |
f83e6885 | 4931 | gcc_checking_assert (ctx->quiet || errorcount); |
09b42213 | 4932 | *non_constant_p = true; |
4933 | return t; | |
4934 | } | |
1227ba74 | 4935 | r = cxx_eval_component_reference (ctx, t, lval, |
09b42213 | 4936 | non_constant_p, overflow_p); |
4937 | break; | |
4938 | ||
4939 | case BIT_FIELD_REF: | |
1227ba74 | 4940 | r = cxx_eval_bit_field_ref (ctx, t, lval, |
09b42213 | 4941 | non_constant_p, overflow_p); |
4942 | break; | |
4943 | ||
4944 | case COND_EXPR: | |
02d7a132 | 4945 | case IF_STMT: |
2a2770c6 | 4946 | if (jump_target && *jump_target) |
4947 | { | |
f1329be6 | 4948 | tree orig_jump = *jump_target; |
02d7a132 | 4949 | tree arg = ((TREE_CODE (t) != IF_STMT || TREE_OPERAND (t, 1)) |
4950 | ? TREE_OPERAND (t, 1) : void_node); | |
2a2770c6 | 4951 | /* When jumping to a label, the label might be either in the |
4952 | then or else blocks, so process then block first in skipping | |
4953 | mode first, and if we are still in the skipping mode at its end, | |
4954 | process the else block too. */ | |
02d7a132 | 4955 | r = cxx_eval_constant_expression (ctx, arg, lval, non_constant_p, |
4956 | overflow_p, jump_target); | |
f1329be6 | 4957 | /* It's possible that we found the label in the then block. But |
4958 | it could have been followed by another jumping statement, e.g. | |
4959 | say we're looking for case 1: | |
4960 | if (cond) | |
4961 | { | |
4962 | // skipped statements | |
4963 | case 1:; // clears up *jump_target | |
4964 | return 1; // and sets it to a RETURN_EXPR | |
4965 | } | |
4966 | else { ... } | |
4967 | in which case we need not go looking to the else block. | |
4968 | (goto is not allowed in a constexpr function.) */ | |
4969 | if (*jump_target == orig_jump) | |
02d7a132 | 4970 | { |
4971 | arg = ((TREE_CODE (t) != IF_STMT || TREE_OPERAND (t, 2)) | |
4972 | ? TREE_OPERAND (t, 2) : void_node); | |
4973 | r = cxx_eval_constant_expression (ctx, arg, lval, non_constant_p, | |
4974 | overflow_p, jump_target); | |
4975 | } | |
2a2770c6 | 4976 | break; |
4977 | } | |
1227ba74 | 4978 | r = cxx_eval_conditional_expression (ctx, t, lval, |
00f21715 | 4979 | non_constant_p, overflow_p, |
4980 | jump_target); | |
09b42213 | 4981 | break; |
31595caf | 4982 | case VEC_COND_EXPR: |
4983 | r = cxx_eval_vector_conditional_expression (ctx, t, non_constant_p, | |
4984 | overflow_p); | |
4985 | break; | |
09b42213 | 4986 | |
4987 | case CONSTRUCTOR: | |
8f46b677 | 4988 | if (TREE_CONSTANT (t) && reduced_constant_expression_p (t)) |
58b0f9ce | 4989 | { |
4990 | /* Don't re-process a constant CONSTRUCTOR, but do fold it to | |
4991 | VECTOR_CST if applicable. */ | |
79e65a6b | 4992 | verify_constructor_flags (t); |
58b0f9ce | 4993 | if (TREE_CONSTANT (t)) |
4994 | return fold (t); | |
4995 | } | |
1227ba74 | 4996 | r = cxx_eval_bare_aggregate (ctx, t, lval, |
09b42213 | 4997 | non_constant_p, overflow_p); |
4998 | break; | |
4999 | ||
5000 | case VEC_INIT_EXPR: | |
5001 | /* We can get this in a defaulted constructor for a class with a | |
5002 | non-static data member of array type. Either the initializer will | |
5003 | be NULL, meaning default-initialization, or it will be an lvalue | |
5004 | or xvalue of the same type, meaning direct-initialization from the | |
5005 | corresponding member. */ | |
1227ba74 | 5006 | r = cxx_eval_vec_init (ctx, t, lval, |
09b42213 | 5007 | non_constant_p, overflow_p); |
5008 | break; | |
5009 | ||
09b42213 | 5010 | case VEC_PERM_EXPR: |
1227ba74 | 5011 | r = cxx_eval_trinary_expression (ctx, t, lval, |
09b42213 | 5012 | non_constant_p, overflow_p); |
5013 | break; | |
5014 | ||
941fafa5 | 5015 | case NOP_EXPR: |
5016 | if (REINTERPRET_CAST_P (t)) | |
5017 | { | |
5018 | if (!ctx->quiet) | |
d3a3cfb8 | 5019 | error_at (cp_expr_loc_or_loc (t, input_location), |
85b9be9b | 5020 | "%<reinterpret_cast%> is not a constant expression"); |
941fafa5 | 5021 | *non_constant_p = true; |
5022 | return t; | |
5023 | } | |
5024 | /* FALLTHROUGH. */ | |
09b42213 | 5025 | case CONVERT_EXPR: |
5026 | case VIEW_CONVERT_EXPR: | |
d2c63826 | 5027 | case UNARY_PLUS_EXPR: |
09b42213 | 5028 | { |
5029 | tree oldop = TREE_OPERAND (t, 0); | |
d2c63826 | 5030 | |
cf72f34d | 5031 | tree op = cxx_eval_constant_expression (ctx, oldop, |
1227ba74 | 5032 | lval, |
b2a43197 | 5033 | non_constant_p, overflow_p); |
09b42213 | 5034 | if (*non_constant_p) |
5035 | return t; | |
f16ed232 | 5036 | tree type = TREE_TYPE (t); |
e8e065dc | 5037 | |
5038 | if (VOID_TYPE_P (type)) | |
5039 | return void_node; | |
5040 | ||
f16ed232 | 5041 | if (TREE_CODE (op) == PTRMEM_CST |
5042 | && !TYPE_PTRMEM_P (type)) | |
5043 | op = cplus_expand_constant (op); | |
941fafa5 | 5044 | |
6a9b35ef | 5045 | if (TREE_CODE (op) == PTRMEM_CST && tcode == NOP_EXPR) |
5046 | { | |
941fafa5 | 5047 | if (!same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (op)) |
5048 | && !can_convert_qual (type, op)) | |
5049 | op = cplus_expand_constant (op); | |
5050 | return cp_fold_convert (type, op); | |
6a9b35ef | 5051 | } |
cb768824 | 5052 | |
d03fa520 | 5053 | if (INDIRECT_TYPE_P (type) && TREE_CODE (op) == INTEGER_CST) |
09b42213 | 5054 | { |
cb768824 | 5055 | if (integer_zerop (op)) |
5056 | { | |
90ad495b | 5057 | if (TYPE_REF_P (type)) |
cb768824 | 5058 | { |
5059 | if (!ctx->quiet) | |
d3a3cfb8 | 5060 | error_at (cp_expr_loc_or_loc (t, input_location), |
cb768824 | 5061 | "dereferencing a null pointer"); |
5062 | *non_constant_p = true; | |
5063 | return t; | |
5064 | } | |
90ad495b | 5065 | else if (TYPE_PTR_P (TREE_TYPE (op))) |
cb768824 | 5066 | { |
5067 | tree from = TREE_TYPE (op); | |
5068 | ||
5069 | if (!can_convert (type, from, tf_none)) | |
5070 | { | |
5071 | if (!ctx->quiet) | |
d3a3cfb8 | 5072 | error_at (cp_expr_loc_or_loc (t, input_location), |
cb768824 | 5073 | "conversion of %qT null pointer to %qT " |
5074 | "is not a constant expression", | |
5075 | from, type); | |
5076 | *non_constant_p = true; | |
5077 | return t; | |
5078 | } | |
5079 | } | |
5080 | } | |
5081 | else | |
5082 | { | |
5083 | /* This detects for example: | |
5084 | reinterpret_cast<void*>(sizeof 0) | |
5085 | */ | |
5086 | if (!ctx->quiet) | |
d3a3cfb8 | 5087 | error_at (cp_expr_loc_or_loc (t, input_location), |
cb768824 | 5088 | "%<reinterpret_cast<%T>(%E)%> is not " |
ea034e2c | 5089 | "a constant expression", |
cb768824 | 5090 | type, op); |
5091 | *non_constant_p = true; | |
5092 | return t; | |
5093 | } | |
09b42213 | 5094 | } |
941fafa5 | 5095 | |
d2c63826 | 5096 | if (op == oldop && tcode != UNARY_PLUS_EXPR) |
09b42213 | 5097 | /* We didn't fold at the top so we could check for ptr-int |
5098 | conversion. */ | |
5099 | return fold (t); | |
941fafa5 | 5100 | |
e8e065dc | 5101 | tree sop; |
5102 | ||
6b53d686 | 5103 | /* Handle an array's bounds having been deduced after we built |
5104 | the wrapping expression. */ | |
5105 | if (same_type_ignoring_tlq_and_bounds_p (type, TREE_TYPE (op))) | |
5106 | r = op; | |
e8e065dc | 5107 | else if (sop = tree_strip_nop_conversions (op), |
5108 | sop != op && (same_type_ignoring_tlq_and_bounds_p | |
5109 | (type, TREE_TYPE (sop)))) | |
5110 | r = sop; | |
6b53d686 | 5111 | else if (tcode == UNARY_PLUS_EXPR) |
d2c63826 | 5112 | r = fold_convert (TREE_TYPE (t), op); |
5113 | else | |
5114 | r = fold_build1 (tcode, type, op); | |
941fafa5 | 5115 | |
09b42213 | 5116 | /* Conversion of an out-of-range value has implementation-defined |
5117 | behavior; the language considers it different from arithmetic | |
5118 | overflow, which is undefined. */ | |
5119 | if (TREE_OVERFLOW_P (r) && !TREE_OVERFLOW_P (op)) | |
5120 | TREE_OVERFLOW (r) = false; | |
5121 | } | |
5122 | break; | |
5123 | ||
5124 | case EMPTY_CLASS_EXPR: | |
5125 | /* This is good enough for a function argument that might not get | |
5126 | used, and they can't do anything with it, so just return it. */ | |
5127 | return t; | |
5128 | ||
9c96033c | 5129 | case STATEMENT_LIST: |
00f21715 | 5130 | new_ctx = *ctx; |
5131 | new_ctx.ctor = new_ctx.object = NULL_TREE; | |
f83e6885 | 5132 | return cxx_eval_statement_list (&new_ctx, t, |
00f21715 | 5133 | non_constant_p, overflow_p, jump_target); |
9c96033c | 5134 | |
5135 | case BIND_EXPR: | |
5136 | return cxx_eval_constant_expression (ctx, BIND_EXPR_BODY (t), | |
1227ba74 | 5137 | lval, |
00f21715 | 5138 | non_constant_p, overflow_p, |
5139 | jump_target); | |
9c96033c | 5140 | |
09b42213 | 5141 | case PREINCREMENT_EXPR: |
5142 | case POSTINCREMENT_EXPR: | |
5143 | case PREDECREMENT_EXPR: | |
5144 | case POSTDECREMENT_EXPR: | |
f83e6885 | 5145 | return cxx_eval_increment_expression (ctx, t, |
1227ba74 | 5146 | lval, non_constant_p, overflow_p); |
9c96033c | 5147 | |
5148 | case LAMBDA_EXPR: | |
09b42213 | 5149 | case NEW_EXPR: |
5150 | case VEC_NEW_EXPR: | |
5151 | case DELETE_EXPR: | |
5152 | case VEC_DELETE_EXPR: | |
5153 | case THROW_EXPR: | |
09b42213 | 5154 | case MODOP_EXPR: |
5155 | /* GCC internal stuff. */ | |
5156 | case VA_ARG_EXPR: | |
09b42213 | 5157 | case NON_DEPENDENT_EXPR: |
5158 | case BASELINK: | |
09b42213 | 5159 | case OFFSET_REF: |
f83e6885 | 5160 | if (!ctx->quiet) |
d3a3cfb8 | 5161 | error_at (cp_expr_loc_or_loc (t, input_location), |
ea034e2c | 5162 | "expression %qE is not a constant expression", t); |
09b42213 | 5163 | *non_constant_p = true; |
5164 | break; | |
5165 | ||
bb6e576c | 5166 | case OBJ_TYPE_REF: |
5167 | { | |
5168 | /* Virtual function call. Let the constexpr machinery figure out | |
5169 | the dynamic type. */ | |
5170 | int token = tree_to_shwi (OBJ_TYPE_REF_TOKEN (t)); | |
5171 | tree obj = OBJ_TYPE_REF_OBJECT (t); | |
5172 | obj = cxx_eval_constant_expression (ctx, obj, lval, non_constant_p, | |
5173 | overflow_p); | |
5174 | /* We expect something in the form of &x.D.2103.D.2094; get x. */ | |
85c4b1bb | 5175 | if (TREE_CODE (obj) != ADDR_EXPR |
5176 | || !DECL_P (get_base_address (TREE_OPERAND (obj, 0)))) | |
bb6e576c | 5177 | { |
5178 | if (!ctx->quiet) | |
5179 | error_at (cp_expr_loc_or_loc (t, input_location), | |
5180 | "expression %qE is not a constant expression", t); | |
5181 | *non_constant_p = true; | |
5182 | return t; | |
5183 | } | |
5184 | obj = TREE_OPERAND (obj, 0); | |
e3cb8102 | 5185 | while (TREE_CODE (obj) == COMPONENT_REF |
5186 | && DECL_FIELD_IS_BASE (TREE_OPERAND (obj, 1))) | |
bb6e576c | 5187 | obj = TREE_OPERAND (obj, 0); |
5188 | tree objtype = TREE_TYPE (obj); | |
5189 | /* Find the function decl in the virtual functions list. TOKEN is | |
5190 | the DECL_VINDEX that says which function we're looking for. */ | |
5191 | tree virtuals = BINFO_VIRTUALS (TYPE_BINFO (objtype)); | |
9a97d94a | 5192 | if (TARGET_VTABLE_USES_DESCRIPTORS) |
5193 | token /= MAX (TARGET_VTABLE_USES_DESCRIPTORS, 1); | |
bb6e576c | 5194 | r = TREE_VALUE (chain_index (token, virtuals)); |
5195 | break; | |
5196 | } | |
5197 | ||
cf72f34d | 5198 | case PLACEHOLDER_EXPR: |
85de9604 | 5199 | /* Use of the value or address of the current object. */ |
5200 | if (tree ctor = lookup_placeholder (ctx, lval, TREE_TYPE (t))) | |
5201 | return cxx_eval_constant_expression (ctx, ctor, lval, | |
5202 | non_constant_p, overflow_p); | |
5203 | /* A placeholder without a referent. We can get here when | |
5204 | checking whether NSDMIs are noexcept, or in massage_init_elt; | |
5205 | just say it's non-constant for now. */ | |
5206 | gcc_assert (ctx->quiet); | |
5207 | *non_constant_p = true; | |
cf72f34d | 5208 | break; |
5209 | ||
cf03ba19 | 5210 | case EXIT_EXPR: |
5211 | { | |
5212 | tree cond = TREE_OPERAND (t, 0); | |
5213 | cond = cxx_eval_constant_expression (ctx, cond, /*lval*/false, | |
5214 | non_constant_p, overflow_p); | |
5215 | VERIFY_CONSTANT (cond); | |
5216 | if (integer_nonzerop (cond)) | |
5217 | *jump_target = t; | |
5218 | } | |
5219 | break; | |
5220 | ||
9c96033c | 5221 | case GOTO_EXPR: |
00f21715 | 5222 | *jump_target = TREE_OPERAND (t, 0); |
d29e4e8c | 5223 | gcc_assert (breaks (jump_target) || continues (jump_target) |
5224 | /* Allow for jumping to a cdtor_label. */ | |
5225 | || returns (jump_target)); | |
00f21715 | 5226 | break; |
5227 | ||
9c96033c | 5228 | case LOOP_EXPR: |
02d7a132 | 5229 | case DO_STMT: |
5230 | case WHILE_STMT: | |
5231 | case FOR_STMT: | |
f83e6885 | 5232 | cxx_eval_loop_expr (ctx, t, |
00f21715 | 5233 | non_constant_p, overflow_p, jump_target); |
5234 | break; | |
5235 | ||
9c96033c | 5236 | case SWITCH_EXPR: |
02d7a132 | 5237 | case SWITCH_STMT: |
f83e6885 | 5238 | cxx_eval_switch_expr (ctx, t, |
00f21715 | 5239 | non_constant_p, overflow_p, jump_target); |
9c96033c | 5240 | break; |
5241 | ||
56c12fd4 | 5242 | case REQUIRES_EXPR: |
5243 | /* It's possible to get a requires-expression in a constant | |
5244 | expression. For example: | |
5245 | ||
5246 | template<typename T> concept bool C() { | |
5247 | return requires (T t) { t; }; | |
5248 | } | |
5249 | ||
5250 | template<typename T> requires !C<T>() void f(T); | |
5251 | ||
5252 | Normalization leaves f with the associated constraint | |
5253 | '!requires (T t) { ... }' which is not transformed into | |
5254 | a constraint. */ | |
5255 | if (!processing_template_decl) | |
5256 | return evaluate_constraint_expression (t, NULL_TREE); | |
5257 | else | |
5258 | *non_constant_p = true; | |
5259 | return t; | |
5260 | ||
24c6ee98 | 5261 | case ANNOTATE_EXPR: |
24c6ee98 | 5262 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), |
5263 | lval, | |
5264 | non_constant_p, overflow_p, | |
5265 | jump_target); | |
5266 | break; | |
5267 | ||
7285637a | 5268 | case USING_STMT: |
5269 | r = void_node; | |
5270 | break; | |
5271 | ||
09b42213 | 5272 | default: |
b9a3af23 | 5273 | if (STATEMENT_CODE_P (TREE_CODE (t))) |
5274 | { | |
5275 | /* This function doesn't know how to deal with pre-genericize | |
5276 | statements; this can only happen with statement-expressions, | |
5277 | so for now just fail. */ | |
5278 | if (!ctx->quiet) | |
5279 | error_at (EXPR_LOCATION (t), | |
ea034e2c | 5280 | "statement is not a constant expression"); |
b9a3af23 | 5281 | } |
5282 | else | |
5283 | internal_error ("unexpected expression %qE of kind %s", t, | |
5284 | get_tree_code_name (TREE_CODE (t))); | |
09b42213 | 5285 | *non_constant_p = true; |
5286 | break; | |
5287 | } | |
5288 | ||
5289 | if (r == error_mark_node) | |
5290 | *non_constant_p = true; | |
5291 | ||
5292 | if (*non_constant_p) | |
5293 | return t; | |
5294 | else | |
5295 | return r; | |
5296 | } | |
5297 | ||
6e1bbaae | 5298 | /* P0859: A function is needed for constant evaluation if it is a constexpr |
5299 | function that is named by an expression ([basic.def.odr]) that is | |
5300 | potentially constant evaluated. | |
5301 | ||
5302 | So we need to instantiate any constexpr functions mentioned by the | |
5303 | expression even if the definition isn't needed for evaluating the | |
5304 | expression. */ | |
5305 | ||
5306 | static tree | |
5307 | instantiate_cx_fn_r (tree *tp, int *walk_subtrees, void */*data*/) | |
5308 | { | |
5309 | if (TREE_CODE (*tp) == FUNCTION_DECL | |
5310 | && DECL_DECLARED_CONSTEXPR_P (*tp) | |
5311 | && !DECL_INITIAL (*tp) | |
eed138cf | 5312 | && !trivial_fn_p (*tp) |
6e1bbaae | 5313 | && DECL_TEMPLOID_INSTANTIATION (*tp)) |
5314 | { | |
5315 | ++function_depth; | |
5316 | instantiate_decl (*tp, /*defer_ok*/false, /*expl_inst*/false); | |
5317 | --function_depth; | |
5318 | } | |
5319 | else if (TREE_CODE (*tp) == CALL_EXPR | |
5320 | || TREE_CODE (*tp) == AGGR_INIT_EXPR) | |
5321 | { | |
5322 | if (EXPR_HAS_LOCATION (*tp)) | |
5323 | input_location = EXPR_LOCATION (*tp); | |
5324 | } | |
5325 | ||
5326 | if (!EXPR_P (*tp)) | |
5327 | *walk_subtrees = 0; | |
5328 | ||
5329 | return NULL_TREE; | |
5330 | } | |
5331 | static void | |
5332 | instantiate_constexpr_fns (tree t) | |
5333 | { | |
5334 | location_t loc = input_location; | |
5335 | cp_walk_tree_without_duplicates (&t, instantiate_cx_fn_r, NULL); | |
5336 | input_location = loc; | |
5337 | } | |
5338 | ||
18d371d3 | 5339 | /* ALLOW_NON_CONSTANT is false if T is required to be a constant expression. |
3f892eaf | 5340 | STRICT has the same sense as for constant_value_1: true if we only allow |
5341 | conforming C++ constant expressions, or false if we want a constant value | |
5342 | even if it doesn't conform. | |
1562c831 | 5343 | MANIFESTLY_CONST_EVAL is true if T is manifestly const-evaluated as |
18d371d3 | 5344 | per P0595 even when ALLOW_NON_CONSTANT is true. */ |
5345 | ||
09b42213 | 5346 | static tree |
cf72f34d | 5347 | cxx_eval_outermost_constant_expr (tree t, bool allow_non_constant, |
18d371d3 | 5348 | bool strict = true, |
1562c831 | 5349 | bool manifestly_const_eval = false, |
18d371d3 | 5350 | tree object = NULL_TREE) |
09b42213 | 5351 | { |
c300fe28 | 5352 | auto_timevar time (TV_CONSTEXPR); |
5353 | ||
09b42213 | 5354 | bool non_constant_p = false; |
5355 | bool overflow_p = false; | |
cf72f34d | 5356 | hash_map<tree,tree> map; |
84f13b2f | 5357 | HOST_WIDE_INT constexpr_ctx_count = 0; |
2631cb67 | 5358 | |
2a2770c6 | 5359 | constexpr_ctx ctx = { NULL, &map, NULL, NULL, NULL, NULL, |
84f13b2f | 5360 | &constexpr_ctx_count, allow_non_constant, strict, |
1562c831 | 5361 | manifestly_const_eval || !allow_non_constant }; |
2631cb67 | 5362 | |
cf72f34d | 5363 | tree type = initialized_type (t); |
cf72f34d | 5364 | tree r = t; |
48c03f15 | 5365 | if (VOID_TYPE_P (type)) |
5366 | return t; | |
cf72f34d | 5367 | if (AGGREGATE_TYPE_P (type) || VECTOR_TYPE_P (type)) |
5368 | { | |
5369 | /* In C++14 an NSDMI can participate in aggregate initialization, | |
5370 | and can refer to the address of the object being initialized, so | |
5371 | we need to pass in the relevant VAR_DECL if we want to do the | |
5372 | evaluation in a single pass. The evaluation will dynamically | |
5373 | update ctx.values for the VAR_DECL. We use the same strategy | |
5374 | for C++11 constexpr constructors that refer to the object being | |
5375 | initialized. */ | |
5376 | ctx.ctor = build_constructor (type, NULL); | |
165d0d5b | 5377 | CONSTRUCTOR_NO_CLEARING (ctx.ctor) = true; |
9c96033c | 5378 | if (!object) |
5379 | { | |
5380 | if (TREE_CODE (t) == TARGET_EXPR) | |
5381 | object = TARGET_EXPR_SLOT (t); | |
5382 | else if (TREE_CODE (t) == AGGR_INIT_EXPR) | |
5383 | object = AGGR_INIT_EXPR_SLOT (t); | |
5384 | } | |
cf72f34d | 5385 | ctx.object = object; |
5386 | if (object) | |
5387 | gcc_assert (same_type_ignoring_top_level_qualifiers_p | |
5388 | (type, TREE_TYPE (object))); | |
5389 | if (object && DECL_P (object)) | |
5390 | map.put (object, ctx.ctor); | |
5391 | if (TREE_CODE (r) == TARGET_EXPR) | |
5392 | /* Avoid creating another CONSTRUCTOR when we expand the | |
5393 | TARGET_EXPR. */ | |
5394 | r = TARGET_EXPR_INITIAL (r); | |
5395 | } | |
5396 | ||
6e1bbaae | 5397 | instantiate_constexpr_fns (r); |
f83e6885 | 5398 | r = cxx_eval_constant_expression (&ctx, r, |
b2a43197 | 5399 | false, &non_constant_p, &overflow_p); |
09b42213 | 5400 | |
5401 | verify_constant (r, allow_non_constant, &non_constant_p, &overflow_p); | |
5402 | ||
bbcc9042 | 5403 | /* Mutable logic is a bit tricky: we want to allow initialization of |
5404 | constexpr variables with mutable members, but we can't copy those | |
5405 | members to another constexpr variable. */ | |
5406 | if (TREE_CODE (r) == CONSTRUCTOR | |
5407 | && CONSTRUCTOR_MUTABLE_POISON (r)) | |
09b42213 | 5408 | { |
09b42213 | 5409 | if (!allow_non_constant) |
bbcc9042 | 5410 | error ("%qE is not a constant expression because it refers to " |
5411 | "mutable subobjects of %qT", t, type); | |
09b42213 | 5412 | non_constant_p = true; |
5413 | } | |
5414 | ||
c6d97004 | 5415 | if (TREE_CODE (r) == CONSTRUCTOR |
165d0d5b | 5416 | && CONSTRUCTOR_NO_CLEARING (r)) |
c6d97004 | 5417 | { |
5418 | if (!allow_non_constant) | |
5419 | error ("%qE is not a constant expression because it refers to " | |
5420 | "an incompletely initialized variable", t); | |
5421 | TREE_CONSTANT (r) = false; | |
5422 | non_constant_p = true; | |
5423 | } | |
5424 | ||
09b42213 | 5425 | /* Technically we should check this for all subexpressions, but that |
5426 | runs into problems with our internal representation of pointer | |
5427 | subtraction and the 5.19 rules are still in flux. */ | |
5428 | if (CONVERT_EXPR_CODE_P (TREE_CODE (r)) | |
5429 | && ARITHMETIC_TYPE_P (TREE_TYPE (r)) | |
5430 | && TREE_CODE (TREE_OPERAND (r, 0)) == ADDR_EXPR) | |
5431 | { | |
5432 | if (!allow_non_constant) | |
5433 | error ("conversion from pointer type %qT " | |
ea034e2c | 5434 | "to arithmetic type %qT in a constant expression", |
09b42213 | 5435 | TREE_TYPE (TREE_OPERAND (r, 0)), TREE_TYPE (r)); |
5436 | non_constant_p = true; | |
5437 | } | |
5438 | ||
5439 | if (!non_constant_p && overflow_p) | |
5440 | non_constant_p = true; | |
5441 | ||
c6c0523b | 5442 | /* Unshare the result unless it's a CONSTRUCTOR in which case it's already |
5443 | unshared. */ | |
5444 | bool should_unshare = true; | |
5445 | if (r == t || TREE_CODE (r) == CONSTRUCTOR) | |
5446 | should_unshare = false; | |
5447 | ||
09b42213 | 5448 | if (non_constant_p && !allow_non_constant) |
5449 | return error_mark_node; | |
5450 | else if (non_constant_p && TREE_CONSTANT (r)) | |
5451 | { | |
18d371d3 | 5452 | /* If __builtin_is_constant_evaluated () was evaluated to true |
5453 | and the result is not a valid constant expression, we need to | |
5454 | punt. */ | |
1562c831 | 5455 | if (manifestly_const_eval) |
18d371d3 | 5456 | return cxx_eval_outermost_constant_expr (t, true, strict, |
5457 | false, object); | |
1d29f4ea | 5458 | /* This isn't actually constant, so unset TREE_CONSTANT. |
5459 | Don't clear TREE_CONSTANT on ADDR_EXPR, as the middle-end requires | |
5460 | it to be set if it is invariant address, even when it is not | |
5461 | a valid C++ constant expression. Wrap it with a NOP_EXPR | |
5462 | instead. */ | |
5463 | if (EXPR_P (r) && TREE_CODE (r) != ADDR_EXPR) | |
09b42213 | 5464 | r = copy_node (r); |
5465 | else if (TREE_CODE (r) == CONSTRUCTOR) | |
5466 | r = build1 (VIEW_CONVERT_EXPR, TREE_TYPE (r), r); | |
5467 | else | |
5468 | r = build_nop (TREE_TYPE (r), r); | |
5469 | TREE_CONSTANT (r) = false; | |
5470 | } | |
59183fff | 5471 | else if (non_constant_p) |
09b42213 | 5472 | return t; |
5473 | ||
c6c0523b | 5474 | if (should_unshare) |
5475 | r = unshare_expr (r); | |
5476 | ||
09b42213 | 5477 | if (TREE_CODE (r) == CONSTRUCTOR && CLASS_TYPE_P (TREE_TYPE (r))) |
5478 | { | |
59183fff | 5479 | r = adjust_temp_type (type, r); |
09b42213 | 5480 | if (TREE_CODE (t) == TARGET_EXPR |
5481 | && TARGET_EXPR_INITIAL (t) == r) | |
5482 | return t; | |
59183fff | 5483 | else if (TREE_CODE (t) != CONSTRUCTOR) |
09b42213 | 5484 | { |
5485 | r = get_target_expr (r); | |
5486 | TREE_CONSTANT (r) = true; | |
09b42213 | 5487 | } |
5488 | } | |
59183fff | 5489 | |
5490 | return r; | |
09b42213 | 5491 | } |
5492 | ||
09b42213 | 5493 | /* If T represents a constant expression returns its reduced value. |
5494 | Otherwise return error_mark_node. If T is dependent, then | |
5495 | return NULL. */ | |
5496 | ||
5497 | tree | |
cf72f34d | 5498 | cxx_constant_value (tree t, tree decl) |
09b42213 | 5499 | { |
18d371d3 | 5500 | return cxx_eval_outermost_constant_expr (t, false, true, true, decl); |
09b42213 | 5501 | } |
5502 | ||
d2c63826 | 5503 | /* Helper routine for fold_simple function. Either return simplified |
5504 | expression T, otherwise NULL_TREE. | |
5505 | In contrast to cp_fully_fold, and to maybe_constant_value, we try to fold | |
5506 | even if we are within template-declaration. So be careful on call, as in | |
5507 | such case types can be undefined. */ | |
5508 | ||
5509 | static tree | |
5510 | fold_simple_1 (tree t) | |
5511 | { | |
5512 | tree op1; | |
5513 | enum tree_code code = TREE_CODE (t); | |
5514 | ||
5515 | switch (code) | |
5516 | { | |
5517 | case INTEGER_CST: | |
5518 | case REAL_CST: | |
5519 | case VECTOR_CST: | |
5520 | case FIXED_CST: | |
5521 | case COMPLEX_CST: | |
5522 | return t; | |
5523 | ||
5524 | case SIZEOF_EXPR: | |
5525 | return fold_sizeof_expr (t); | |
5526 | ||
5527 | case ABS_EXPR: | |
19b4138e | 5528 | case ABSU_EXPR: |
d2c63826 | 5529 | case CONJ_EXPR: |
5530 | case REALPART_EXPR: | |
5531 | case IMAGPART_EXPR: | |
5532 | case NEGATE_EXPR: | |
5533 | case BIT_NOT_EXPR: | |
5534 | case TRUTH_NOT_EXPR: | |
5535 | case NOP_EXPR: | |
5536 | case VIEW_CONVERT_EXPR: | |
5537 | case CONVERT_EXPR: | |
5538 | case FLOAT_EXPR: | |
5539 | case FIX_TRUNC_EXPR: | |
5540 | case FIXED_CONVERT_EXPR: | |
5541 | case ADDR_SPACE_CONVERT_EXPR: | |
5542 | ||
5543 | op1 = TREE_OPERAND (t, 0); | |
5544 | ||
5545 | t = const_unop (code, TREE_TYPE (t), op1); | |
5546 | if (!t) | |
5547 | return NULL_TREE; | |
5548 | ||
5549 | if (CONVERT_EXPR_CODE_P (code) | |
5550 | && TREE_OVERFLOW_P (t) && !TREE_OVERFLOW_P (op1)) | |
5551 | TREE_OVERFLOW (t) = false; | |
5552 | return t; | |
5553 | ||
5554 | default: | |
5555 | return NULL_TREE; | |
5556 | } | |
5557 | } | |
5558 | ||
5559 | /* If T is a simple constant expression, returns its simplified value. | |
6fe5fea9 | 5560 | Otherwise returns T. In contrast to maybe_constant_value we |
d2c63826 | 5561 | simplify only few operations on constant-expressions, and we don't |
5562 | try to simplify constexpressions. */ | |
5563 | ||
5564 | tree | |
5565 | fold_simple (tree t) | |
5566 | { | |
d2c63826 | 5567 | if (processing_template_decl) |
5568 | return t; | |
5569 | ||
6fe5fea9 | 5570 | tree r = fold_simple_1 (t); |
5571 | if (r) | |
5572 | return r; | |
d2c63826 | 5573 | |
6fe5fea9 | 5574 | return t; |
d2c63826 | 5575 | } |
5576 | ||
09b42213 | 5577 | /* If T is a constant expression, returns its reduced value. |
5578 | Otherwise, if T does not have TREE_CONSTANT set, returns T. | |
1562c831 | 5579 | Otherwise, returns a version of T without TREE_CONSTANT. |
5580 | MANIFESTLY_CONST_EVAL is true if T is manifestly const-evaluated | |
5581 | as per P0595. */ | |
09b42213 | 5582 | |
b601ad30 | 5583 | static GTY((deletable)) hash_map<tree, tree> *cv_cache; |
5584 | ||
5585 | tree | |
1562c831 | 5586 | maybe_constant_value (tree t, tree decl, bool manifestly_const_eval) |
09b42213 | 5587 | { |
5588 | tree r; | |
5589 | ||
7e1f8be4 | 5590 | if (!is_nondependent_constant_expression (t)) |
09b42213 | 5591 | { |
5592 | if (TREE_OVERFLOW_P (t)) | |
5593 | { | |
5594 | t = build_nop (TREE_TYPE (t), t); | |
5595 | TREE_CONSTANT (t) = false; | |
5596 | } | |
5597 | return t; | |
5598 | } | |
b601ad30 | 5599 | else if (CONSTANT_CLASS_P (t)) |
5600 | /* No caching or evaluation needed. */ | |
5601 | return t; | |
5602 | ||
1562c831 | 5603 | if (manifestly_const_eval) |
5604 | return cxx_eval_outermost_constant_expr (t, true, true, true, decl); | |
5605 | ||
b601ad30 | 5606 | if (cv_cache == NULL) |
5607 | cv_cache = hash_map<tree, tree>::create_ggc (101); | |
5608 | if (tree *cached = cv_cache->get (t)) | |
5609 | return *cached; | |
09b42213 | 5610 | |
18d371d3 | 5611 | r = cxx_eval_outermost_constant_expr (t, true, true, false, decl); |
5e8689fb | 5612 | gcc_checking_assert (r == t |
5613 | || CONVERT_EXPR_P (t) | |
5614 | || TREE_CODE (t) == VIEW_CONVERT_EXPR | |
5615 | || (TREE_CONSTANT (t) && !TREE_CONSTANT (r)) | |
5616 | || !cp_tree_equal (r, t)); | |
b601ad30 | 5617 | cv_cache->put (t, r); |
09b42213 | 5618 | return r; |
5619 | } | |
5620 | ||
2a655a4c | 5621 | /* Dispose of the whole CV_CACHE. */ |
5622 | ||
5623 | static void | |
5624 | clear_cv_cache (void) | |
5625 | { | |
5626 | if (cv_cache != NULL) | |
5627 | cv_cache->empty (); | |
5628 | } | |
5629 | ||
f553d9f8 | 5630 | /* Dispose of the whole CV_CACHE and FOLD_CACHE. */ |
a0c919f7 | 5631 | |
5632 | void | |
f553d9f8 | 5633 | clear_cv_and_fold_caches (void) |
a0c919f7 | 5634 | { |
2a655a4c | 5635 | clear_cv_cache (); |
f553d9f8 | 5636 | clear_fold_cache (); |
a0c919f7 | 5637 | } |
5638 | ||
cf13db0c | 5639 | /* Internal function handling expressions in templates for |
5640 | fold_non_dependent_expr and fold_non_dependent_init. | |
5641 | ||
5642 | If we're in a template, but T isn't value dependent, simplify | |
5643 | it. We're supposed to treat: | |
5644 | ||
5645 | template <typename T> void f(T[1 + 1]); | |
5646 | template <typename T> void f(T[2]); | |
5647 | ||
5648 | as two declarations of the same function, for example. */ | |
5649 | ||
5650 | static tree | |
5651 | fold_non_dependent_expr_template (tree t, tsubst_flags_t complain, | |
5652 | bool manifestly_const_eval) | |
5653 | { | |
5654 | gcc_assert (processing_template_decl); | |
5655 | ||
5656 | if (is_nondependent_constant_expression (t)) | |
5657 | { | |
5658 | processing_template_decl_sentinel s; | |
5659 | t = instantiate_non_dependent_expr_internal (t, complain); | |
5660 | ||
5661 | if (type_unknown_p (t) || BRACE_ENCLOSED_INITIALIZER_P (t)) | |
5662 | { | |
5663 | if (TREE_OVERFLOW_P (t)) | |
5664 | { | |
5665 | t = build_nop (TREE_TYPE (t), t); | |
5666 | TREE_CONSTANT (t) = false; | |
5667 | } | |
5668 | return t; | |
5669 | } | |
5670 | ||
5671 | tree r = cxx_eval_outermost_constant_expr (t, true, true, | |
5672 | manifestly_const_eval, | |
5673 | NULL_TREE); | |
5674 | /* cp_tree_equal looks through NOPs, so allow them. */ | |
5675 | gcc_checking_assert (r == t | |
5676 | || CONVERT_EXPR_P (t) | |
5677 | || TREE_CODE (t) == VIEW_CONVERT_EXPR | |
5678 | || (TREE_CONSTANT (t) && !TREE_CONSTANT (r)) | |
5679 | || !cp_tree_equal (r, t)); | |
5680 | return r; | |
5681 | } | |
5682 | else if (TREE_OVERFLOW_P (t)) | |
5683 | { | |
5684 | t = build_nop (TREE_TYPE (t), t); | |
5685 | TREE_CONSTANT (t) = false; | |
5686 | } | |
5687 | ||
5688 | return t; | |
5689 | } | |
5690 | ||
21131a05 | 5691 | /* Like maybe_constant_value but first fully instantiate the argument. |
5692 | ||
5693 | Note: this is equivalent to instantiate_non_dependent_expr_sfinae | |
006b503a | 5694 | (t, complain) followed by maybe_constant_value but is more efficient, |
5695 | because it calls instantiation_dependent_expression_p and | |
5696 | potential_constant_expression at most once. | |
4749c4ac | 5697 | The manifestly_const_eval argument is passed to maybe_constant_value. |
006b503a | 5698 | |
5699 | Callers should generally pass their active complain, or if they are in a | |
5700 | non-template, diagnosing context, they can use the default of | |
5701 | tf_warning_or_error. Callers that might be within a template context, don't | |
5702 | have a complain parameter, and aren't going to remember the result for long | |
5703 | (e.g. null_ptr_cst_p), can pass tf_none and deal with error_mark_node | |
5704 | appropriately. */ | |
21131a05 | 5705 | |
5706 | tree | |
006b503a | 5707 | fold_non_dependent_expr (tree t, |
4749c4ac | 5708 | tsubst_flags_t complain /* = tf_warning_or_error */, |
5709 | bool manifestly_const_eval /* = false */) | |
21131a05 | 5710 | { |
5711 | if (t == NULL_TREE) | |
5712 | return NULL_TREE; | |
5713 | ||
cf13db0c | 5714 | if (processing_template_decl) |
5715 | return fold_non_dependent_expr_template (t, complain, | |
5716 | manifestly_const_eval); | |
21131a05 | 5717 | |
cf13db0c | 5718 | return maybe_constant_value (t, NULL_TREE, manifestly_const_eval); |
5719 | } | |
21131a05 | 5720 | |
21131a05 | 5721 | |
cf13db0c | 5722 | /* Like maybe_constant_init but first fully instantiate the argument. */ |
21131a05 | 5723 | |
cf13db0c | 5724 | tree |
5725 | fold_non_dependent_init (tree t, | |
5726 | tsubst_flags_t complain /*=tf_warning_or_error*/, | |
5727 | bool manifestly_const_eval /*=false*/) | |
5728 | { | |
5729 | if (t == NULL_TREE) | |
5730 | return NULL_TREE; | |
5731 | ||
5732 | if (processing_template_decl) | |
5733 | { | |
5734 | t = fold_non_dependent_expr_template (t, complain, | |
5735 | manifestly_const_eval); | |
5736 | /* maybe_constant_init does this stripping, so do it here too. */ | |
5737 | if (TREE_CODE (t) == TARGET_EXPR) | |
21131a05 | 5738 | { |
cf13db0c | 5739 | tree init = TARGET_EXPR_INITIAL (t); |
5740 | if (TREE_CODE (init) == CONSTRUCTOR) | |
5741 | t = init; | |
21131a05 | 5742 | } |
5743 | return t; | |
5744 | } | |
5745 | ||
cf13db0c | 5746 | return maybe_constant_init (t, NULL_TREE, manifestly_const_eval); |
21131a05 | 5747 | } |
5748 | ||
09b42213 | 5749 | /* Like maybe_constant_value, but returns a CONSTRUCTOR directly, rather |
18d371d3 | 5750 | than wrapped in a TARGET_EXPR. |
5751 | ALLOW_NON_CONSTANT is false if T is required to be a constant expression. | |
1562c831 | 5752 | MANIFESTLY_CONST_EVAL is true if T is manifestly const-evaluated as |
18d371d3 | 5753 | per P0595 even when ALLOW_NON_CONSTANT is true. */ |
09b42213 | 5754 | |
0c703e14 | 5755 | static tree |
18d371d3 | 5756 | maybe_constant_init_1 (tree t, tree decl, bool allow_non_constant, |
1562c831 | 5757 | bool manifestly_const_eval) |
09b42213 | 5758 | { |
d2c63826 | 5759 | if (!t) |
5760 | return t; | |
09b42213 | 5761 | if (TREE_CODE (t) == EXPR_STMT) |
5762 | t = TREE_OPERAND (t, 0); | |
5763 | if (TREE_CODE (t) == CONVERT_EXPR | |
5764 | && VOID_TYPE_P (TREE_TYPE (t))) | |
5765 | t = TREE_OPERAND (t, 0); | |
9c96033c | 5766 | if (TREE_CODE (t) == INIT_EXPR) |
5767 | t = TREE_OPERAND (t, 1); | |
c6d97004 | 5768 | if (TREE_CODE (t) == TARGET_EXPR) |
5769 | t = TARGET_EXPR_INITIAL (t); | |
7e1f8be4 | 5770 | if (!is_nondependent_static_init_expression (t)) |
2055d27a | 5771 | /* Don't try to evaluate it. */; |
0c703e14 | 5772 | else if (CONSTANT_CLASS_P (t) && allow_non_constant) |
b601ad30 | 5773 | /* No evaluation needed. */; |
2055d27a | 5774 | else |
18d371d3 | 5775 | t = cxx_eval_outermost_constant_expr (t, allow_non_constant, |
fbe79a84 | 5776 | /*strict*/false, |
1562c831 | 5777 | manifestly_const_eval, decl); |
09b42213 | 5778 | if (TREE_CODE (t) == TARGET_EXPR) |
5779 | { | |
5780 | tree init = TARGET_EXPR_INITIAL (t); | |
5781 | if (TREE_CODE (init) == CONSTRUCTOR) | |
5782 | t = init; | |
5783 | } | |
5784 | return t; | |
5785 | } | |
5786 | ||
0c703e14 | 5787 | /* Wrapper for maybe_constant_init_1 which permits non constants. */ |
5788 | ||
5789 | tree | |
1562c831 | 5790 | maybe_constant_init (tree t, tree decl, bool manifestly_const_eval) |
0c703e14 | 5791 | { |
1562c831 | 5792 | return maybe_constant_init_1 (t, decl, true, manifestly_const_eval); |
0c703e14 | 5793 | } |
5794 | ||
5795 | /* Wrapper for maybe_constant_init_1 which does not permit non constants. */ | |
5796 | ||
5797 | tree | |
5798 | cxx_constant_init (tree t, tree decl) | |
5799 | { | |
18d371d3 | 5800 | return maybe_constant_init_1 (t, decl, false, true); |
0c703e14 | 5801 | } |
5802 | ||
09b42213 | 5803 | #if 0 |
5804 | /* FIXME see ADDR_EXPR section in potential_constant_expression_1. */ | |
5805 | /* Return true if the object referred to by REF has automatic or thread | |
5806 | local storage. */ | |
5807 | ||
5808 | enum { ck_ok, ck_bad, ck_unknown }; | |
5809 | static int | |
5810 | check_automatic_or_tls (tree ref) | |
5811 | { | |
3754d046 | 5812 | machine_mode mode; |
81bc0f0f | 5813 | poly_int64 bitsize, bitpos; |
09b42213 | 5814 | tree offset; |
5815 | int volatilep = 0, unsignedp = 0; | |
5816 | tree decl = get_inner_reference (ref, &bitsize, &bitpos, &offset, | |
5817 | &mode, &unsignedp, &volatilep, false); | |
5818 | duration_kind dk; | |
5819 | ||
5820 | /* If there isn't a decl in the middle, we don't know the linkage here, | |
5821 | and this isn't a constant expression anyway. */ | |
5822 | if (!DECL_P (decl)) | |
5823 | return ck_unknown; | |
5824 | dk = decl_storage_duration (decl); | |
5825 | return (dk == dk_auto || dk == dk_thread) ? ck_bad : ck_ok; | |
5826 | } | |
5827 | #endif | |
5828 | ||
ad6978a6 | 5829 | /* Data structure for passing data from potential_constant_expression_1 |
5830 | to check_for_return_continue via cp_walk_tree. */ | |
5831 | struct check_for_return_continue_data { | |
5832 | hash_set<tree> *pset; | |
5833 | tree continue_stmt; | |
5834 | }; | |
5835 | ||
5836 | /* Helper function for potential_constant_expression_1 SWITCH_STMT handling, | |
5837 | called through cp_walk_tree. Return the first RETURN_EXPR found, or note | |
5838 | the first CONTINUE_STMT if RETURN_EXPR is not found. */ | |
5839 | static tree | |
5840 | check_for_return_continue (tree *tp, int *walk_subtrees, void *data) | |
5841 | { | |
5842 | tree t = *tp, s; | |
5843 | check_for_return_continue_data *d = (check_for_return_continue_data *) data; | |
5844 | switch (TREE_CODE (t)) | |
5845 | { | |
5846 | case RETURN_EXPR: | |
5847 | return t; | |
5848 | ||
5849 | case CONTINUE_STMT: | |
5850 | if (d->continue_stmt == NULL_TREE) | |
5851 | d->continue_stmt = t; | |
5852 | break; | |
5853 | ||
5854 | #define RECUR(x) \ | |
5855 | if (tree r = cp_walk_tree (&x, check_for_return_continue, data, \ | |
5856 | d->pset)) \ | |
5857 | return r | |
5858 | ||
5859 | /* For loops, walk subtrees manually, so that continue stmts found | |
5860 | inside of the bodies of the loops are ignored. */ | |
5861 | case DO_STMT: | |
5862 | *walk_subtrees = 0; | |
5863 | RECUR (DO_COND (t)); | |
5864 | s = d->continue_stmt; | |
5865 | RECUR (DO_BODY (t)); | |
5866 | d->continue_stmt = s; | |
5867 | break; | |
5868 | ||
5869 | case WHILE_STMT: | |
5870 | *walk_subtrees = 0; | |
5871 | RECUR (WHILE_COND (t)); | |
5872 | s = d->continue_stmt; | |
5873 | RECUR (WHILE_BODY (t)); | |
5874 | d->continue_stmt = s; | |
5875 | break; | |
5876 | ||
5877 | case FOR_STMT: | |
5878 | *walk_subtrees = 0; | |
5879 | RECUR (FOR_INIT_STMT (t)); | |
5880 | RECUR (FOR_COND (t)); | |
5881 | RECUR (FOR_EXPR (t)); | |
5882 | s = d->continue_stmt; | |
5883 | RECUR (FOR_BODY (t)); | |
5884 | d->continue_stmt = s; | |
5885 | break; | |
5886 | ||
5887 | case RANGE_FOR_STMT: | |
5888 | *walk_subtrees = 0; | |
5889 | RECUR (RANGE_FOR_EXPR (t)); | |
5890 | s = d->continue_stmt; | |
5891 | RECUR (RANGE_FOR_BODY (t)); | |
5892 | d->continue_stmt = s; | |
5893 | break; | |
5894 | #undef RECUR | |
5895 | ||
5896 | case STATEMENT_LIST: | |
5897 | case CONSTRUCTOR: | |
5898 | break; | |
5899 | ||
5900 | default: | |
5901 | if (!EXPR_P (t)) | |
5902 | *walk_subtrees = 0; | |
5903 | break; | |
5904 | } | |
5905 | ||
5906 | return NULL_TREE; | |
5907 | } | |
5908 | ||
09b42213 | 5909 | /* Return true if T denotes a potentially constant expression. Issue |
5910 | diagnostic as appropriate under control of FLAGS. If WANT_RVAL is true, | |
7e1f8be4 | 5911 | an lvalue-rvalue conversion is implied. If NOW is true, we want to |
5912 | consider the expression in the current context, independent of constexpr | |
5913 | substitution. | |
09b42213 | 5914 | |
5915 | C++0x [expr.const] used to say | |
5916 | ||
5917 | 6 An expression is a potential constant expression if it is | |
5918 | a constant expression where all occurrences of function | |
5919 | parameters are replaced by arbitrary constant expressions | |
5920 | of the appropriate type. | |
5921 | ||
5922 | 2 A conditional expression is a constant expression unless it | |
5923 | involves one of the following as a potentially evaluated | |
5924 | subexpression (3.2), but subexpressions of logical AND (5.14), | |
5925 | logical OR (5.15), and conditional (5.16) operations that are | |
5926 | not evaluated are not considered. */ | |
5927 | ||
5928 | static bool | |
7e1f8be4 | 5929 | potential_constant_expression_1 (tree t, bool want_rval, bool strict, bool now, |
32fee334 | 5930 | tsubst_flags_t flags, tree *jump_target) |
09b42213 | 5931 | { |
7e1f8be4 | 5932 | #define RECUR(T,RV) \ |
32fee334 | 5933 | potential_constant_expression_1 ((T), (RV), strict, now, flags, jump_target) |
7e1f8be4 | 5934 | |
09b42213 | 5935 | enum { any = false, rval = true }; |
5936 | int i; | |
5937 | tree tmp; | |
5938 | ||
5939 | if (t == error_mark_node) | |
5940 | return false; | |
5941 | if (t == NULL_TREE) | |
5942 | return true; | |
d3a3cfb8 | 5943 | location_t loc = cp_expr_loc_or_loc (t, input_location); |
32fee334 | 5944 | |
5945 | if (*jump_target) | |
5946 | /* If we are jumping, ignore everything. This is simpler than the | |
5947 | cxx_eval_constant_expression handling because we only need to be | |
5948 | conservatively correct, and we don't necessarily have a constant value | |
5949 | available, so we don't bother with switch tracking. */ | |
5950 | return true; | |
5951 | ||
04ced4a2 | 5952 | if (TREE_THIS_VOLATILE (t) && want_rval) |
09b42213 | 5953 | { |
5954 | if (flags & tf_error) | |
04ced4a2 | 5955 | error_at (loc, "lvalue-to-rvalue conversion of a volatile lvalue " |
5956 | "%qE with type %qT", t, TREE_TYPE (t)); | |
09b42213 | 5957 | return false; |
5958 | } | |
5959 | if (CONSTANT_CLASS_P (t)) | |
5960 | return true; | |
c7282bf2 | 5961 | if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_TYPED) |
5962 | && TREE_TYPE (t) == error_mark_node) | |
5963 | return false; | |
09b42213 | 5964 | |
5965 | switch (TREE_CODE (t)) | |
5966 | { | |
5967 | case FUNCTION_DECL: | |
5968 | case BASELINK: | |
5969 | case TEMPLATE_DECL: | |
5970 | case OVERLOAD: | |
5971 | case TEMPLATE_ID_EXPR: | |
5972 | case LABEL_DECL: | |
5973 | case LABEL_EXPR: | |
9c96033c | 5974 | case CASE_LABEL_EXPR: |
09b42213 | 5975 | case CONST_DECL: |
5976 | case SIZEOF_EXPR: | |
5977 | case ALIGNOF_EXPR: | |
5978 | case OFFSETOF_EXPR: | |
5979 | case NOEXCEPT_EXPR: | |
5980 | case TEMPLATE_PARM_INDEX: | |
5981 | case TRAIT_EXPR: | |
5982 | case IDENTIFIER_NODE: | |
5983 | case USERDEF_LITERAL: | |
5984 | /* We can see a FIELD_DECL in a pointer-to-member expression. */ | |
5985 | case FIELD_DECL: | |
d2c63826 | 5986 | case RESULT_DECL: |
09b42213 | 5987 | case USING_DECL: |
9c96033c | 5988 | case USING_STMT: |
cf72f34d | 5989 | case PLACEHOLDER_EXPR: |
56c12fd4 | 5990 | case REQUIRES_EXPR: |
33603066 | 5991 | case STATIC_ASSERT: |
90567983 | 5992 | case DEBUG_BEGIN_STMT: |
09b42213 | 5993 | return true; |
5994 | ||
32fee334 | 5995 | case RETURN_EXPR: |
5996 | if (!RECUR (TREE_OPERAND (t, 0), any)) | |
5997 | return false; | |
5998 | /* FALLTHROUGH */ | |
5999 | ||
6000 | case BREAK_STMT: | |
6001 | case CONTINUE_STMT: | |
6002 | *jump_target = t; | |
6003 | return true; | |
6004 | ||
7e1f8be4 | 6005 | case PARM_DECL: |
6006 | if (now) | |
6007 | { | |
6008 | if (flags & tf_error) | |
6009 | error ("%qE is not a constant expression", t); | |
6010 | return false; | |
6011 | } | |
6012 | return true; | |
6013 | ||
09b42213 | 6014 | case AGGR_INIT_EXPR: |
6015 | case CALL_EXPR: | |
6016 | /* -- an invocation of a function other than a constexpr function | |
6017 | or a constexpr constructor. */ | |
6018 | { | |
6019 | tree fun = get_function_named_in_call (t); | |
6020 | const int nargs = call_expr_nargs (t); | |
6021 | i = 0; | |
6022 | ||
9c96033c | 6023 | if (fun == NULL_TREE) |
6024 | { | |
732905bb | 6025 | /* Reset to allow the function to continue past the end |
6026 | of the block below. Otherwise return early. */ | |
6027 | bool bail = true; | |
6028 | ||
32cf7025 | 6029 | if (TREE_CODE (t) == CALL_EXPR |
6030 | && CALL_EXPR_FN (t) == NULL_TREE) | |
6031 | switch (CALL_EXPR_IFN (t)) | |
6032 | { | |
6033 | /* These should be ignored, they are optimized away from | |
6034 | constexpr functions. */ | |
6035 | case IFN_UBSAN_NULL: | |
6036 | case IFN_UBSAN_BOUNDS: | |
6037 | case IFN_UBSAN_VPTR: | |
3c77f69c | 6038 | case IFN_FALLTHROUGH: |
32cf7025 | 6039 | return true; |
732905bb | 6040 | |
6041 | case IFN_ADD_OVERFLOW: | |
6042 | case IFN_SUB_OVERFLOW: | |
6043 | case IFN_MUL_OVERFLOW: | |
6e1b2ffb | 6044 | case IFN_LAUNDER: |
59409f09 | 6045 | case IFN_VEC_CONVERT: |
732905bb | 6046 | bail = false; |
59409f09 | 6047 | break; |
732905bb | 6048 | |
32cf7025 | 6049 | default: |
6050 | break; | |
6051 | } | |
732905bb | 6052 | |
6053 | if (bail) | |
6054 | { | |
6055 | /* fold_call_expr can't do anything with IFN calls. */ | |
6056 | if (flags & tf_error) | |
d6a08f5c | 6057 | error_at (loc, "call to internal function %qE", t); |
732905bb | 6058 | return false; |
6059 | } | |
9c96033c | 6060 | } |
732905bb | 6061 | |
6062 | if (fun && is_overloaded_fn (fun)) | |
09b42213 | 6063 | { |
6064 | if (TREE_CODE (fun) == FUNCTION_DECL) | |
6065 | { | |
6066 | if (builtin_valid_in_constant_expr_p (fun)) | |
6067 | return true; | |
6068 | if (!DECL_DECLARED_CONSTEXPR_P (fun) | |
6069 | /* Allow any built-in function; if the expansion | |
6070 | isn't constant, we'll deal with that then. */ | |
a0e9bfbb | 6071 | && !fndecl_built_in_p (fun)) |
09b42213 | 6072 | { |
6073 | if (flags & tf_error) | |
6074 | { | |
5967b28b | 6075 | error_at (loc, "call to non-%<constexpr%> function %qD", |
d6a08f5c | 6076 | fun); |
09b42213 | 6077 | explain_invalid_constexpr_fn (fun); |
6078 | } | |
6079 | return false; | |
6080 | } | |
6081 | /* A call to a non-static member function takes the address | |
6082 | of the object as the first argument. But in a constant | |
6083 | expression the address will be folded away, so look | |
6084 | through it now. */ | |
6085 | if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fun) | |
6086 | && !DECL_CONSTRUCTOR_P (fun)) | |
6087 | { | |
6088 | tree x = get_nth_callarg (t, 0); | |
6089 | if (is_this_parameter (x)) | |
cf72f34d | 6090 | return true; |
7e1f8be4 | 6091 | /* Don't require an immediately constant value, as |
6092 | constexpr substitution might not use the value. */ | |
6093 | bool sub_now = false; | |
6094 | if (!potential_constant_expression_1 (x, rval, strict, | |
32fee334 | 6095 | sub_now, flags, |
6096 | jump_target)) | |
09b42213 | 6097 | return false; |
6098 | i = 1; | |
6099 | } | |
6100 | } | |
6101 | else | |
6102 | { | |
2055d27a | 6103 | if (!RECUR (fun, true)) |
09b42213 | 6104 | return false; |
6105 | fun = get_first_fn (fun); | |
6106 | } | |
6107 | /* Skip initial arguments to base constructors. */ | |
6108 | if (DECL_BASE_CONSTRUCTOR_P (fun)) | |
6109 | i = num_artificial_parms_for (fun); | |
6110 | fun = DECL_ORIGIN (fun); | |
6111 | } | |
732905bb | 6112 | else if (fun) |
09b42213 | 6113 | { |
2055d27a | 6114 | if (RECUR (fun, rval)) |
09b42213 | 6115 | /* Might end up being a constant function pointer. */; |
6116 | else | |
6117 | return false; | |
6118 | } | |
6119 | for (; i < nargs; ++i) | |
6120 | { | |
6121 | tree x = get_nth_callarg (t, i); | |
b2742b58 | 6122 | /* In a template, reference arguments haven't been converted to |
6123 | REFERENCE_TYPE and we might not even know if the parameter | |
6124 | is a reference, so accept lvalue constants too. */ | |
6125 | bool rv = processing_template_decl ? any : rval; | |
7e1f8be4 | 6126 | /* Don't require an immediately constant value, as constexpr |
6127 | substitution might not use the value of the argument. */ | |
6128 | bool sub_now = false; | |
6129 | if (!potential_constant_expression_1 (x, rv, strict, | |
32fee334 | 6130 | sub_now, flags, jump_target)) |
09b42213 | 6131 | return false; |
6132 | } | |
6133 | return true; | |
6134 | } | |
6135 | ||
6136 | case NON_LVALUE_EXPR: | |
6137 | /* -- an lvalue-to-rvalue conversion (4.1) unless it is applied to | |
6138 | -- an lvalue of integral type that refers to a non-volatile | |
6139 | const variable or static data member initialized with | |
6140 | constant expressions, or | |
6141 | ||
6142 | -- an lvalue of literal type that refers to non-volatile | |
6143 | object defined with constexpr, or that refers to a | |
6144 | sub-object of such an object; */ | |
2055d27a | 6145 | return RECUR (TREE_OPERAND (t, 0), rval); |
09b42213 | 6146 | |
6147 | case VAR_DECL: | |
9c8aeb66 | 6148 | if (DECL_HAS_VALUE_EXPR_P (t)) |
297de7bc | 6149 | { |
d0e2b7e7 | 6150 | if (now && is_normal_capture_proxy (t)) |
297de7bc | 6151 | { |
6152 | /* -- in a lambda-expression, a reference to this or to a | |
6153 | variable with automatic storage duration defined outside that | |
6154 | lambda-expression, where the reference would be an | |
6155 | odr-use. */ | |
6156 | if (flags & tf_error) | |
6157 | { | |
6158 | tree cap = DECL_CAPTURED_VARIABLE (t); | |
6159 | error ("lambda capture of %qE is not a constant expression", | |
6160 | cap); | |
6161 | if (!want_rval && decl_constant_var_p (cap)) | |
6162 | inform (input_location, "because it is used as a glvalue"); | |
6163 | } | |
6164 | return false; | |
6165 | } | |
6166 | return RECUR (DECL_VALUE_EXPR (t), rval); | |
6167 | } | |
2055d27a | 6168 | if (want_rval |
33603066 | 6169 | && !var_in_maybe_constexpr_fn (t) |
c7282bf2 | 6170 | && !type_dependent_expression_p (t) |
8d6486e1 | 6171 | && !decl_maybe_constant_var_p (t) |
2055d27a | 6172 | && (strict |
6173 | || !CP_TYPE_CONST_NON_VOLATILE_P (TREE_TYPE (t)) | |
8d6486e1 | 6174 | || (DECL_INITIAL (t) |
6175 | && !DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (t))) | |
c7282bf2 | 6176 | && COMPLETE_TYPE_P (TREE_TYPE (t)) |
cd5a9ed1 | 6177 | && !is_really_empty_class (TREE_TYPE (t), /*ignore_vptr*/false)) |
09b42213 | 6178 | { |
6179 | if (flags & tf_error) | |
6180 | non_const_var_error (t); | |
6181 | return false; | |
6182 | } | |
6183 | return true; | |
6184 | ||
6185 | case NOP_EXPR: | |
92651efb | 6186 | if (REINTERPRET_CAST_P (t)) |
6187 | { | |
6188 | if (flags & tf_error) | |
85b9be9b | 6189 | error_at (loc, "%<reinterpret_cast%> is not a constant expression"); |
92651efb | 6190 | return false; |
6191 | } | |
6192 | /* FALLTHRU */ | |
09b42213 | 6193 | case CONVERT_EXPR: |
6194 | case VIEW_CONVERT_EXPR: | |
6195 | /* -- a reinterpret_cast. FIXME not implemented, and this rule | |
6196 | may change to something more specific to type-punning (DR 1312). */ | |
6197 | { | |
6198 | tree from = TREE_OPERAND (t, 0); | |
d582d140 | 6199 | if (location_wrapper_p (t)) |
6200 | return (RECUR (from, want_rval)); | |
6201 | if (INDIRECT_TYPE_P (TREE_TYPE (t))) | |
09b42213 | 6202 | { |
d582d140 | 6203 | STRIP_ANY_LOCATION_WRAPPER (from); |
6204 | if (TREE_CODE (from) == INTEGER_CST | |
6205 | && !integer_zerop (from)) | |
6206 | { | |
6207 | if (flags & tf_error) | |
85b9be9b | 6208 | error_at (loc, |
6209 | "%<reinterpret_cast%> from integer to pointer"); | |
d582d140 | 6210 | return false; |
6211 | } | |
09b42213 | 6212 | } |
2055d27a | 6213 | return (RECUR (from, TREE_CODE (t) != VIEW_CONVERT_EXPR)); |
09b42213 | 6214 | } |
6215 | ||
cd45162d | 6216 | case ADDRESSOF_EXPR: |
6217 | /* This is like ADDR_EXPR, except it won't form pointer-to-member. */ | |
6218 | t = TREE_OPERAND (t, 0); | |
6219 | goto handle_addr_expr; | |
6220 | ||
09b42213 | 6221 | case ADDR_EXPR: |
6222 | /* -- a unary operator & that is applied to an lvalue that | |
6223 | designates an object with thread or automatic storage | |
6224 | duration; */ | |
6225 | t = TREE_OPERAND (t, 0); | |
6226 | ||
6227 | if (TREE_CODE (t) == OFFSET_REF && PTRMEM_OK_P (t)) | |
6228 | /* A pointer-to-member constant. */ | |
6229 | return true; | |
6230 | ||
cd45162d | 6231 | handle_addr_expr: |
09b42213 | 6232 | #if 0 |
6233 | /* FIXME adjust when issue 1197 is fully resolved. For now don't do | |
6234 | any checking here, as we might dereference the pointer later. If | |
6235 | we remove this code, also remove check_automatic_or_tls. */ | |
6236 | i = check_automatic_or_tls (t); | |
6237 | if (i == ck_ok) | |
6238 | return true; | |
6239 | if (i == ck_bad) | |
6240 | { | |
6241 | if (flags & tf_error) | |
6242 | error ("address-of an object %qE with thread local or " | |
6243 | "automatic storage is not a constant expression", t); | |
6244 | return false; | |
6245 | } | |
6246 | #endif | |
2055d27a | 6247 | return RECUR (t, any); |
09b42213 | 6248 | |
20b34a56 | 6249 | case REALPART_EXPR: |
6250 | case IMAGPART_EXPR: | |
09b42213 | 6251 | case COMPONENT_REF: |
6252 | case BIT_FIELD_REF: | |
6253 | case ARROW_EXPR: | |
6254 | case OFFSET_REF: | |
6255 | /* -- a class member access unless its postfix-expression is | |
6256 | of literal type or of pointer to literal type. */ | |
6257 | /* This test would be redundant, as it follows from the | |
6258 | postfix-expression being a potential constant expression. */ | |
eade0940 | 6259 | if (type_unknown_p (t)) |
6260 | return true; | |
2055d27a | 6261 | return RECUR (TREE_OPERAND (t, 0), want_rval); |
09b42213 | 6262 | |
6263 | case EXPR_PACK_EXPANSION: | |
2055d27a | 6264 | return RECUR (PACK_EXPANSION_PATTERN (t), want_rval); |
09b42213 | 6265 | |
6266 | case INDIRECT_REF: | |
6267 | { | |
6268 | tree x = TREE_OPERAND (t, 0); | |
6269 | STRIP_NOPS (x); | |
997bbf70 | 6270 | if (is_this_parameter (x) && !is_capture_proxy (x)) |
09b42213 | 6271 | { |
b7e4a558 | 6272 | if (!var_in_maybe_constexpr_fn (x)) |
09b42213 | 6273 | { |
6274 | if (flags & tf_error) | |
d6a08f5c | 6275 | error_at (loc, "use of %<this%> in a constant expression"); |
09b42213 | 6276 | return false; |
6277 | } | |
09b42213 | 6278 | return true; |
6279 | } | |
2055d27a | 6280 | return RECUR (x, rval); |
09b42213 | 6281 | } |
6282 | ||
9c96033c | 6283 | case STATEMENT_LIST: |
6284 | { | |
6285 | tree_stmt_iterator i; | |
6286 | for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i)) | |
6287 | { | |
2055d27a | 6288 | if (!RECUR (tsi_stmt (i), any)) |
9c96033c | 6289 | return false; |
6290 | } | |
6291 | return true; | |
6292 | } | |
6293 | break; | |
6294 | ||
6295 | case MODIFY_EXPR: | |
6296 | if (cxx_dialect < cxx14) | |
6297 | goto fail; | |
2055d27a | 6298 | if (!RECUR (TREE_OPERAND (t, 0), any)) |
9c96033c | 6299 | return false; |
2055d27a | 6300 | if (!RECUR (TREE_OPERAND (t, 1), rval)) |
9c96033c | 6301 | return false; |
6302 | return true; | |
6303 | ||
6304 | case MODOP_EXPR: | |
6305 | if (cxx_dialect < cxx14) | |
6306 | goto fail; | |
2055d27a | 6307 | if (!RECUR (TREE_OPERAND (t, 0), rval)) |
9c96033c | 6308 | return false; |
2055d27a | 6309 | if (!RECUR (TREE_OPERAND (t, 2), rval)) |
9c96033c | 6310 | return false; |
6311 | return true; | |
6312 | ||
9c96033c | 6313 | case DO_STMT: |
2055d27a | 6314 | if (!RECUR (DO_COND (t), rval)) |
9c96033c | 6315 | return false; |
2055d27a | 6316 | if (!RECUR (DO_BODY (t), any)) |
9c96033c | 6317 | return false; |
32fee334 | 6318 | if (breaks (jump_target) || continues (jump_target)) |
6319 | *jump_target = NULL_TREE; | |
9c96033c | 6320 | return true; |
6321 | ||
6322 | case FOR_STMT: | |
2055d27a | 6323 | if (!RECUR (FOR_INIT_STMT (t), any)) |
9c96033c | 6324 | return false; |
10811950 | 6325 | tmp = FOR_COND (t); |
6326 | if (!RECUR (tmp, rval)) | |
9c96033c | 6327 | return false; |
10811950 | 6328 | if (tmp) |
6329 | { | |
6330 | if (!processing_template_decl) | |
6331 | tmp = cxx_eval_outermost_constant_expr (tmp, true); | |
f807ff66 | 6332 | /* If we couldn't evaluate the condition, it might not ever be |
6333 | true. */ | |
6334 | if (!integer_onep (tmp)) | |
10811950 | 6335 | return true; |
6336 | } | |
2055d27a | 6337 | if (!RECUR (FOR_EXPR (t), any)) |
9c96033c | 6338 | return false; |
2055d27a | 6339 | if (!RECUR (FOR_BODY (t), any)) |
9c96033c | 6340 | return false; |
32fee334 | 6341 | if (breaks (jump_target) || continues (jump_target)) |
6342 | *jump_target = NULL_TREE; | |
9c96033c | 6343 | return true; |
6344 | ||
33603066 | 6345 | case RANGE_FOR_STMT: |
f4416678 | 6346 | if (!RECUR (RANGE_FOR_INIT_STMT (t), any)) |
6347 | return false; | |
33603066 | 6348 | if (!RECUR (RANGE_FOR_EXPR (t), any)) |
6349 | return false; | |
6350 | if (!RECUR (RANGE_FOR_BODY (t), any)) | |
6351 | return false; | |
32fee334 | 6352 | if (breaks (jump_target) || continues (jump_target)) |
6353 | *jump_target = NULL_TREE; | |
33603066 | 6354 | return true; |
6355 | ||
9c96033c | 6356 | case WHILE_STMT: |
10811950 | 6357 | tmp = WHILE_COND (t); |
6358 | if (!RECUR (tmp, rval)) | |
9c96033c | 6359 | return false; |
10811950 | 6360 | if (!processing_template_decl) |
6361 | tmp = cxx_eval_outermost_constant_expr (tmp, true); | |
f807ff66 | 6362 | /* If we couldn't evaluate the condition, it might not ever be true. */ |
6363 | if (!integer_onep (tmp)) | |
10811950 | 6364 | return true; |
2055d27a | 6365 | if (!RECUR (WHILE_BODY (t), any)) |
9c96033c | 6366 | return false; |
32fee334 | 6367 | if (breaks (jump_target) || continues (jump_target)) |
6368 | *jump_target = NULL_TREE; | |
9c96033c | 6369 | return true; |
6370 | ||
6371 | case SWITCH_STMT: | |
2055d27a | 6372 | if (!RECUR (SWITCH_STMT_COND (t), rval)) |
9c96033c | 6373 | return false; |
748c426a | 6374 | /* FIXME we don't check SWITCH_STMT_BODY currently, because even |
ad6978a6 | 6375 | unreachable labels would be checked and it is enough if there is |
6376 | a single switch cond value for which it is a valid constant | |
6377 | expression. We need to check if there are any RETURN_EXPRs | |
6378 | or CONTINUE_STMTs inside of the body though, as in that case | |
6379 | we need to set *jump_target. */ | |
6380 | else | |
6381 | { | |
6382 | hash_set<tree> pset; | |
6383 | check_for_return_continue_data data = { &pset, NULL_TREE }; | |
6384 | if (tree ret_expr | |
6385 | = cp_walk_tree (&SWITCH_STMT_BODY (t), check_for_return_continue, | |
6386 | &data, &pset)) | |
6387 | /* The switch might return. */ | |
6388 | *jump_target = ret_expr; | |
6389 | else if (data.continue_stmt) | |
6390 | /* The switch can't return, but might continue. */ | |
6391 | *jump_target = data.continue_stmt; | |
6392 | } | |
9c96033c | 6393 | return true; |
6394 | ||
da7981e0 | 6395 | case STMT_EXPR: |
2055d27a | 6396 | return RECUR (STMT_EXPR_STMT (t), rval); |
da7981e0 | 6397 | |
09b42213 | 6398 | case LAMBDA_EXPR: |
27db1f50 | 6399 | if (cxx_dialect >= cxx17) |
6400 | /* In C++17 lambdas can be constexpr, don't give up yet. */ | |
6401 | return true; | |
6402 | else if (flags & tf_error) | |
6403 | error_at (loc, "lambda-expression is not a constant expression " | |
6404 | "before C++17"); | |
6405 | return false; | |
6406 | ||
09b42213 | 6407 | case DYNAMIC_CAST_EXPR: |
6408 | case PSEUDO_DTOR_EXPR: | |
09b42213 | 6409 | case NEW_EXPR: |
6410 | case VEC_NEW_EXPR: | |
6411 | case DELETE_EXPR: | |
6412 | case VEC_DELETE_EXPR: | |
6413 | case THROW_EXPR: | |
d6a08f5c | 6414 | case OMP_PARALLEL: |
6415 | case OMP_TASK: | |
6416 | case OMP_FOR: | |
83728168 | 6417 | case OMP_SIMD: |
d6a08f5c | 6418 | case OMP_DISTRIBUTE: |
6419 | case OMP_TASKLOOP: | |
6420 | case OMP_TEAMS: | |
6421 | case OMP_TARGET_DATA: | |
6422 | case OMP_TARGET: | |
6423 | case OMP_SECTIONS: | |
6424 | case OMP_ORDERED: | |
6425 | case OMP_CRITICAL: | |
6426 | case OMP_SINGLE: | |
6427 | case OMP_SECTION: | |
6428 | case OMP_MASTER: | |
6429 | case OMP_TASKGROUP: | |
6430 | case OMP_TARGET_UPDATE: | |
6431 | case OMP_TARGET_ENTER_DATA: | |
6432 | case OMP_TARGET_EXIT_DATA: | |
09b42213 | 6433 | case OMP_ATOMIC: |
6434 | case OMP_ATOMIC_READ: | |
6435 | case OMP_ATOMIC_CAPTURE_OLD: | |
6436 | case OMP_ATOMIC_CAPTURE_NEW: | |
7e5a76c8 | 6437 | case OMP_DEPOBJ: |
d6a08f5c | 6438 | case OACC_PARALLEL: |
6439 | case OACC_KERNELS: | |
6440 | case OACC_DATA: | |
6441 | case OACC_HOST_DATA: | |
6442 | case OACC_LOOP: | |
6443 | case OACC_CACHE: | |
6444 | case OACC_DECLARE: | |
6445 | case OACC_ENTER_DATA: | |
6446 | case OACC_EXIT_DATA: | |
6447 | case OACC_UPDATE: | |
09b42213 | 6448 | /* GCC internal stuff. */ |
6449 | case VA_ARG_EXPR: | |
09b42213 | 6450 | case TRANSACTION_EXPR: |
9c96033c | 6451 | case ASM_EXPR: |
9abecca2 | 6452 | case AT_ENCODE_EXPR: |
9c96033c | 6453 | fail: |
09b42213 | 6454 | if (flags & tf_error) |
d6a08f5c | 6455 | error_at (loc, "expression %qE is not a constant expression", t); |
09b42213 | 6456 | return false; |
6457 | ||
bb6e576c | 6458 | case OBJ_TYPE_REF: |
6459 | if (cxx_dialect >= cxx2a) | |
6460 | /* In C++2a virtual calls can be constexpr, don't give up yet. */ | |
6461 | return true; | |
6462 | else if (flags & tf_error) | |
85b9be9b | 6463 | error_at (loc, |
6464 | "virtual functions cannot be %<constexpr%> before C++2a"); | |
bb6e576c | 6465 | return false; |
6466 | ||
09b42213 | 6467 | case TYPEID_EXPR: |
6468 | /* -- a typeid expression whose operand is of polymorphic | |
6469 | class type; */ | |
6470 | { | |
6471 | tree e = TREE_OPERAND (t, 0); | |
6472 | if (!TYPE_P (e) && !type_dependent_expression_p (e) | |
6473 | && TYPE_POLYMORPHIC_P (TREE_TYPE (e))) | |
6474 | { | |
6475 | if (flags & tf_error) | |
85b9be9b | 6476 | error_at (loc, "%<typeid%> is not a constant expression " |
d6a08f5c | 6477 | "because %qE is of polymorphic type", e); |
09b42213 | 6478 | return false; |
6479 | } | |
6480 | return true; | |
6481 | } | |
6482 | ||
57e83b58 | 6483 | case POINTER_DIFF_EXPR: |
09b42213 | 6484 | case MINUS_EXPR: |
09b42213 | 6485 | want_rval = true; |
6486 | goto binary; | |
6487 | ||
6488 | case LT_EXPR: | |
6489 | case LE_EXPR: | |
6490 | case GT_EXPR: | |
6491 | case GE_EXPR: | |
6492 | case EQ_EXPR: | |
6493 | case NE_EXPR: | |
09b42213 | 6494 | want_rval = true; |
6495 | goto binary; | |
6496 | ||
9c96033c | 6497 | case PREINCREMENT_EXPR: |
6498 | case POSTINCREMENT_EXPR: | |
6499 | case PREDECREMENT_EXPR: | |
6500 | case POSTDECREMENT_EXPR: | |
6501 | if (cxx_dialect < cxx14) | |
6502 | goto fail; | |
6503 | goto unary; | |
6504 | ||
09b42213 | 6505 | case BIT_NOT_EXPR: |
6506 | /* A destructor. */ | |
6507 | if (TYPE_P (TREE_OPERAND (t, 0))) | |
6508 | return true; | |
e3533433 | 6509 | /* fall through. */ |
09b42213 | 6510 | |
09b42213 | 6511 | case CONJ_EXPR: |
6512 | case SAVE_EXPR: | |
6513 | case FIX_TRUNC_EXPR: | |
6514 | case FLOAT_EXPR: | |
6515 | case NEGATE_EXPR: | |
6516 | case ABS_EXPR: | |
1c67942e | 6517 | case ABSU_EXPR: |
09b42213 | 6518 | case TRUTH_NOT_EXPR: |
6519 | case FIXED_CONVERT_EXPR: | |
6520 | case UNARY_PLUS_EXPR: | |
6fdf70f5 | 6521 | case UNARY_LEFT_FOLD_EXPR: |
6522 | case UNARY_RIGHT_FOLD_EXPR: | |
9c96033c | 6523 | unary: |
2055d27a | 6524 | return RECUR (TREE_OPERAND (t, 0), rval); |
09b42213 | 6525 | |
6526 | case CAST_EXPR: | |
6527 | case CONST_CAST_EXPR: | |
6528 | case STATIC_CAST_EXPR: | |
6529 | case REINTERPRET_CAST_EXPR: | |
6530 | case IMPLICIT_CONV_EXPR: | |
6531 | if (cxx_dialect < cxx11 | |
6532 | && !dependent_type_p (TREE_TYPE (t)) | |
6533 | && !INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))) | |
6534 | /* In C++98, a conversion to non-integral type can't be part of a | |
6535 | constant expression. */ | |
6536 | { | |
6537 | if (flags & tf_error) | |
d6a08f5c | 6538 | error_at (loc, |
6539 | "cast to non-integral type %qT in a constant expression", | |
6540 | TREE_TYPE (t)); | |
09b42213 | 6541 | return false; |
6542 | } | |
e0ccd480 | 6543 | /* This might be a conversion from a class to a (potentially) literal |
6544 | type. Let's consider it potentially constant since the conversion | |
6545 | might be a constexpr user-defined conversion. */ | |
6546 | else if (cxx_dialect >= cxx11 | |
6547 | && (dependent_type_p (TREE_TYPE (t)) | |
6548 | || !COMPLETE_TYPE_P (TREE_TYPE (t)) | |
6549 | || literal_type_p (TREE_TYPE (t))) | |
6550 | && TREE_OPERAND (t, 0)) | |
6551 | { | |
6552 | tree type = TREE_TYPE (TREE_OPERAND (t, 0)); | |
6553 | /* If this is a dependent type, it could end up being a class | |
6554 | with conversions. */ | |
6555 | if (type == NULL_TREE || WILDCARD_TYPE_P (type)) | |
6556 | return true; | |
6557 | /* Or a non-dependent class which has conversions. */ | |
6558 | else if (CLASS_TYPE_P (type) | |
6559 | && (TYPE_HAS_CONVERSION (type) || dependent_scope_p (type))) | |
6560 | return true; | |
6561 | } | |
09b42213 | 6562 | |
2055d27a | 6563 | return (RECUR (TREE_OPERAND (t, 0), |
90ad495b | 6564 | !TYPE_REF_P (TREE_TYPE (t)))); |
09b42213 | 6565 | |
9c96033c | 6566 | case BIND_EXPR: |
2055d27a | 6567 | return RECUR (BIND_EXPR_BODY (t), want_rval); |
9c96033c | 6568 | |
9c96033c | 6569 | case CLEANUP_POINT_EXPR: |
6570 | case MUST_NOT_THROW_EXPR: | |
6571 | case TRY_CATCH_EXPR: | |
7f67d68c | 6572 | case TRY_BLOCK: |
9c96033c | 6573 | case EH_SPEC_BLOCK: |
6574 | case EXPR_STMT: | |
09b42213 | 6575 | case PAREN_EXPR: |
6576 | case NON_DEPENDENT_EXPR: | |
6577 | /* For convenience. */ | |
d1980671 | 6578 | case LOOP_EXPR: |
6579 | case EXIT_EXPR: | |
2055d27a | 6580 | return RECUR (TREE_OPERAND (t, 0), want_rval); |
09b42213 | 6581 | |
33603066 | 6582 | case DECL_EXPR: |
6583 | tmp = DECL_EXPR_DECL (t); | |
6584 | if (VAR_P (tmp) && !DECL_ARTIFICIAL (tmp)) | |
6585 | { | |
6586 | if (TREE_STATIC (tmp)) | |
6587 | { | |
6588 | if (flags & tf_error) | |
6589 | error_at (DECL_SOURCE_LOCATION (tmp), "%qD declared " | |
8d6486e1 | 6590 | "%<static%> in %<constexpr%> context", tmp); |
33603066 | 6591 | return false; |
6592 | } | |
6593 | else if (CP_DECL_THREAD_LOCAL_P (tmp)) | |
6594 | { | |
6595 | if (flags & tf_error) | |
6596 | error_at (DECL_SOURCE_LOCATION (tmp), "%qD declared " | |
8d6486e1 | 6597 | "%<thread_local%> in %<constexpr%> context", tmp); |
33603066 | 6598 | return false; |
6599 | } | |
282ea908 | 6600 | else if (!check_for_uninitialized_const_var |
6601 | (tmp, /*constexpr_context_p=*/true, flags)) | |
6602 | return false; | |
33603066 | 6603 | } |
6604 | return RECUR (tmp, want_rval); | |
6605 | ||
7f67d68c | 6606 | case TRY_FINALLY_EXPR: |
6607 | return (RECUR (TREE_OPERAND (t, 0), want_rval) | |
6608 | && RECUR (TREE_OPERAND (t, 1), any)); | |
6609 | ||
09b42213 | 6610 | case SCOPE_REF: |
2055d27a | 6611 | return RECUR (TREE_OPERAND (t, 1), want_rval); |
09b42213 | 6612 | |
6613 | case TARGET_EXPR: | |
07d8961c | 6614 | if (!TARGET_EXPR_DIRECT_INIT_P (t) |
6615 | && !literal_type_p (TREE_TYPE (t))) | |
09b42213 | 6616 | { |
6617 | if (flags & tf_error) | |
6618 | { | |
bc35ef65 | 6619 | auto_diagnostic_group d; |
d6a08f5c | 6620 | error_at (loc, "temporary of non-literal type %qT in a " |
6621 | "constant expression", TREE_TYPE (t)); | |
09b42213 | 6622 | explain_non_literal_class (TREE_TYPE (t)); |
6623 | } | |
6624 | return false; | |
6625 | } | |
e3533433 | 6626 | /* FALLTHRU */ |
09b42213 | 6627 | case INIT_EXPR: |
2055d27a | 6628 | return RECUR (TREE_OPERAND (t, 1), rval); |
09b42213 | 6629 | |
6630 | case CONSTRUCTOR: | |
6631 | { | |
6632 | vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (t); | |
6633 | constructor_elt *ce; | |
6634 | for (i = 0; vec_safe_iterate (v, i, &ce); ++i) | |
2055d27a | 6635 | if (!RECUR (ce->value, want_rval)) |
09b42213 | 6636 | return false; |
6637 | return true; | |
6638 | } | |
6639 | ||
6640 | case TREE_LIST: | |
6641 | { | |
6642 | gcc_assert (TREE_PURPOSE (t) == NULL_TREE | |
6643 | || DECL_P (TREE_PURPOSE (t))); | |
2055d27a | 6644 | if (!RECUR (TREE_VALUE (t), want_rval)) |
09b42213 | 6645 | return false; |
6646 | if (TREE_CHAIN (t) == NULL_TREE) | |
6647 | return true; | |
2055d27a | 6648 | return RECUR (TREE_CHAIN (t), want_rval); |
09b42213 | 6649 | } |
6650 | ||
6651 | case TRUNC_DIV_EXPR: | |
6652 | case CEIL_DIV_EXPR: | |
6653 | case FLOOR_DIV_EXPR: | |
6654 | case ROUND_DIV_EXPR: | |
6655 | case TRUNC_MOD_EXPR: | |
6656 | case CEIL_MOD_EXPR: | |
6657 | case ROUND_MOD_EXPR: | |
6658 | { | |
6659 | tree denom = TREE_OPERAND (t, 1); | |
2055d27a | 6660 | if (!RECUR (denom, rval)) |
09b42213 | 6661 | return false; |
6662 | /* We can't call cxx_eval_outermost_constant_expr on an expression | |
21131a05 | 6663 | that hasn't been through instantiate_non_dependent_expr yet. */ |
09b42213 | 6664 | if (!processing_template_decl) |
6665 | denom = cxx_eval_outermost_constant_expr (denom, true); | |
6666 | if (integer_zerop (denom)) | |
6667 | { | |
6668 | if (flags & tf_error) | |
ea034e2c | 6669 | error ("division by zero is not a constant expression"); |
09b42213 | 6670 | return false; |
6671 | } | |
6672 | else | |
6673 | { | |
6674 | want_rval = true; | |
2055d27a | 6675 | return RECUR (TREE_OPERAND (t, 0), want_rval); |
09b42213 | 6676 | } |
6677 | } | |
6678 | ||
6679 | case COMPOUND_EXPR: | |
6680 | { | |
6681 | /* check_return_expr sometimes wraps a TARGET_EXPR in a | |
6682 | COMPOUND_EXPR; don't get confused. Also handle EMPTY_CLASS_EXPR | |
6683 | introduced by build_call_a. */ | |
6684 | tree op0 = TREE_OPERAND (t, 0); | |
6685 | tree op1 = TREE_OPERAND (t, 1); | |
6686 | STRIP_NOPS (op1); | |
6687 | if ((TREE_CODE (op0) == TARGET_EXPR && op1 == TARGET_EXPR_SLOT (op0)) | |
6688 | || TREE_CODE (op1) == EMPTY_CLASS_EXPR) | |
2055d27a | 6689 | return RECUR (op0, want_rval); |
09b42213 | 6690 | else |
6691 | goto binary; | |
6692 | } | |
6693 | ||
6694 | /* If the first operand is the non-short-circuit constant, look at | |
6695 | the second operand; otherwise we only care about the first one for | |
6696 | potentiality. */ | |
6697 | case TRUTH_AND_EXPR: | |
6698 | case TRUTH_ANDIF_EXPR: | |
6699 | tmp = boolean_true_node; | |
6700 | goto truth; | |
6701 | case TRUTH_OR_EXPR: | |
6702 | case TRUTH_ORIF_EXPR: | |
6703 | tmp = boolean_false_node; | |
6704 | truth: | |
6705 | { | |
6706 | tree op = TREE_OPERAND (t, 0); | |
2055d27a | 6707 | if (!RECUR (op, rval)) |
09b42213 | 6708 | return false; |
6709 | if (!processing_template_decl) | |
6710 | op = cxx_eval_outermost_constant_expr (op, true); | |
6711 | if (tree_int_cst_equal (op, tmp)) | |
2055d27a | 6712 | return RECUR (TREE_OPERAND (t, 1), rval); |
09b42213 | 6713 | else |
6714 | return true; | |
6715 | } | |
6716 | ||
6717 | case PLUS_EXPR: | |
6718 | case MULT_EXPR: | |
6719 | case POINTER_PLUS_EXPR: | |
6720 | case RDIV_EXPR: | |
6721 | case EXACT_DIV_EXPR: | |
6722 | case MIN_EXPR: | |
6723 | case MAX_EXPR: | |
6724 | case LSHIFT_EXPR: | |
6725 | case RSHIFT_EXPR: | |
6726 | case LROTATE_EXPR: | |
6727 | case RROTATE_EXPR: | |
6728 | case BIT_IOR_EXPR: | |
6729 | case BIT_XOR_EXPR: | |
6730 | case BIT_AND_EXPR: | |
6731 | case TRUTH_XOR_EXPR: | |
6732 | case UNORDERED_EXPR: | |
6733 | case ORDERED_EXPR: | |
6734 | case UNLT_EXPR: | |
6735 | case UNLE_EXPR: | |
6736 | case UNGT_EXPR: | |
6737 | case UNGE_EXPR: | |
6738 | case UNEQ_EXPR: | |
6739 | case LTGT_EXPR: | |
6740 | case RANGE_EXPR: | |
6741 | case COMPLEX_EXPR: | |
6742 | want_rval = true; | |
6743 | /* Fall through. */ | |
6744 | case ARRAY_REF: | |
6745 | case ARRAY_RANGE_REF: | |
6746 | case MEMBER_REF: | |
6747 | case DOTSTAR_EXPR: | |
f0abe78f | 6748 | case MEM_REF: |
6fdf70f5 | 6749 | case BINARY_LEFT_FOLD_EXPR: |
6750 | case BINARY_RIGHT_FOLD_EXPR: | |
09b42213 | 6751 | binary: |
6752 | for (i = 0; i < 2; ++i) | |
2055d27a | 6753 | if (!RECUR (TREE_OPERAND (t, i), want_rval)) |
09b42213 | 6754 | return false; |
6755 | return true; | |
6756 | ||
09b42213 | 6757 | case VEC_PERM_EXPR: |
6758 | for (i = 0; i < 3; ++i) | |
2055d27a | 6759 | if (!RECUR (TREE_OPERAND (t, i), true)) |
09b42213 | 6760 | return false; |
6761 | return true; | |
6762 | ||
6763 | case COND_EXPR: | |
b0fe8b95 | 6764 | if (COND_EXPR_IS_VEC_DELETE (t)) |
6765 | { | |
6766 | if (flags & tf_error) | |
d6a08f5c | 6767 | error_at (loc, "%<delete[]%> is not a constant expression"); |
b0fe8b95 | 6768 | return false; |
6769 | } | |
6770 | /* Fall through. */ | |
6771 | case IF_STMT: | |
09b42213 | 6772 | case VEC_COND_EXPR: |
6773 | /* If the condition is a known constant, we know which of the legs we | |
6774 | care about; otherwise we only require that the condition and | |
6775 | either of the legs be potentially constant. */ | |
6776 | tmp = TREE_OPERAND (t, 0); | |
2055d27a | 6777 | if (!RECUR (tmp, rval)) |
09b42213 | 6778 | return false; |
6779 | if (!processing_template_decl) | |
6780 | tmp = cxx_eval_outermost_constant_expr (tmp, true); | |
6781 | if (integer_zerop (tmp)) | |
2055d27a | 6782 | return RECUR (TREE_OPERAND (t, 2), want_rval); |
09b42213 | 6783 | else if (TREE_CODE (tmp) == INTEGER_CST) |
2055d27a | 6784 | return RECUR (TREE_OPERAND (t, 1), want_rval); |
09b42213 | 6785 | for (i = 1; i < 3; ++i) |
6786 | if (potential_constant_expression_1 (TREE_OPERAND (t, i), | |
32fee334 | 6787 | want_rval, strict, now, |
6788 | tf_none, jump_target)) | |
09b42213 | 6789 | return true; |
6790 | if (flags & tf_error) | |
d6a08f5c | 6791 | error_at (loc, "expression %qE is not a constant expression", t); |
09b42213 | 6792 | return false; |
6793 | ||
6794 | case VEC_INIT_EXPR: | |
6795 | if (VEC_INIT_EXPR_IS_CONSTEXPR (t)) | |
6796 | return true; | |
6797 | if (flags & tf_error) | |
6798 | { | |
d6a08f5c | 6799 | error_at (loc, "non-constant array initialization"); |
09b42213 | 6800 | diagnose_non_constexpr_vec_init (t); |
6801 | } | |
6802 | return false; | |
6803 | ||
db1ae94f | 6804 | case TYPE_DECL: |
6805 | case TAG_DEFN: | |
6806 | /* We can see these in statement-expressions. */ | |
6807 | return true; | |
6808 | ||
fd130325 | 6809 | case CLEANUP_STMT: |
d2c63826 | 6810 | case EMPTY_CLASS_EXPR: |
38ef3642 | 6811 | case PREDICT_EXPR: |
d2c63826 | 6812 | return false; |
6813 | ||
d1980671 | 6814 | case GOTO_EXPR: |
6815 | { | |
6816 | tree *target = &TREE_OPERAND (t, 0); | |
d40a1eac | 6817 | /* Gotos representing break and continue are OK. */ |
6818 | if (breaks (target) || continues (target)) | |
32fee334 | 6819 | { |
6820 | *jump_target = *target; | |
6821 | return true; | |
6822 | } | |
d40a1eac | 6823 | if (flags & tf_error) |
d6a08f5c | 6824 | error_at (loc, "%<goto%> is not a constant expression"); |
d40a1eac | 6825 | return false; |
d1980671 | 6826 | } |
6827 | ||
24c6ee98 | 6828 | case ANNOTATE_EXPR: |
24c6ee98 | 6829 | return RECUR (TREE_OPERAND (t, 0), rval); |
6830 | ||
09b42213 | 6831 | default: |
6832 | if (objc_is_property_ref (t)) | |
6833 | return false; | |
6834 | ||
6835 | sorry ("unexpected AST of kind %s", get_tree_code_name (TREE_CODE (t))); | |
d40a1eac | 6836 | gcc_unreachable (); |
09b42213 | 6837 | return false; |
6838 | } | |
2055d27a | 6839 | #undef RECUR |
09b42213 | 6840 | } |
6841 | ||
32fee334 | 6842 | bool |
6843 | potential_constant_expression_1 (tree t, bool want_rval, bool strict, bool now, | |
6844 | tsubst_flags_t flags) | |
6845 | { | |
6846 | tree target = NULL_TREE; | |
6847 | return potential_constant_expression_1 (t, want_rval, strict, now, | |
6848 | flags, &target); | |
6849 | } | |
6850 | ||
09b42213 | 6851 | /* The main entry point to the above. */ |
6852 | ||
6853 | bool | |
6854 | potential_constant_expression (tree t) | |
6855 | { | |
7e1f8be4 | 6856 | return potential_constant_expression_1 (t, false, true, false, tf_none); |
09b42213 | 6857 | } |
6858 | ||
6859 | /* As above, but require a constant rvalue. */ | |
6860 | ||
6861 | bool | |
6862 | potential_rvalue_constant_expression (tree t) | |
6863 | { | |
7e1f8be4 | 6864 | return potential_constant_expression_1 (t, true, true, false, tf_none); |
09b42213 | 6865 | } |
6866 | ||
6867 | /* Like above, but complain about non-constant expressions. */ | |
6868 | ||
6869 | bool | |
6870 | require_potential_constant_expression (tree t) | |
6871 | { | |
786721dc | 6872 | return potential_constant_expression_1 (t, false, true, false, |
6873 | tf_warning_or_error); | |
09b42213 | 6874 | } |
6875 | ||
6876 | /* Cross product of the above. */ | |
6877 | ||
6878 | bool | |
6879 | require_potential_rvalue_constant_expression (tree t) | |
6880 | { | |
786721dc | 6881 | return potential_constant_expression_1 (t, true, true, false, |
6882 | tf_warning_or_error); | |
6883 | } | |
6884 | ||
6885 | /* Like above, but don't consider PARM_DECL a potential_constant_expression. */ | |
6886 | ||
6887 | bool | |
6888 | require_rvalue_constant_expression (tree t) | |
6889 | { | |
6890 | return potential_constant_expression_1 (t, true, true, true, | |
6891 | tf_warning_or_error); | |
7e1f8be4 | 6892 | } |
6893 | ||
6894 | /* Like potential_constant_expression, but don't consider possible constexpr | |
6895 | substitution of the current function. That is, PARM_DECL qualifies under | |
6896 | potential_constant_expression, but not here. | |
6897 | ||
6898 | This is basically what you can check when any actual constant values might | |
6899 | be value-dependent. */ | |
6900 | ||
6901 | bool | |
6902 | is_constant_expression (tree t) | |
6903 | { | |
6904 | return potential_constant_expression_1 (t, false, true, true, tf_none); | |
6905 | } | |
6906 | ||
6907 | /* Like above, but complain about non-constant expressions. */ | |
6908 | ||
6909 | bool | |
6910 | require_constant_expression (tree t) | |
6911 | { | |
6912 | return potential_constant_expression_1 (t, false, true, true, | |
6913 | tf_warning_or_error); | |
6914 | } | |
6915 | ||
6916 | /* Like is_constant_expression, but allow const variables that are not allowed | |
6917 | under constexpr rules. */ | |
6918 | ||
6919 | bool | |
6920 | is_static_init_expression (tree t) | |
6921 | { | |
6922 | return potential_constant_expression_1 (t, false, false, true, tf_none); | |
09b42213 | 6923 | } |
6924 | ||
29cf24ec | 6925 | /* Returns true if T is a potential constant expression that is not |
6926 | instantiation-dependent, and therefore a candidate for constant folding even | |
6927 | in a template. */ | |
6928 | ||
6929 | bool | |
7e1f8be4 | 6930 | is_nondependent_constant_expression (tree t) |
29cf24ec | 6931 | { |
6932 | return (!type_unknown_p (t) | |
6933 | && !BRACE_ENCLOSED_INITIALIZER_P (t) | |
7e1f8be4 | 6934 | && is_constant_expression (t) |
29cf24ec | 6935 | && !instantiation_dependent_expression_p (t)); |
6936 | } | |
6937 | ||
6938 | /* Returns true if T is a potential static initializer expression that is not | |
6939 | instantiation-dependent. */ | |
6940 | ||
6941 | bool | |
7e1f8be4 | 6942 | is_nondependent_static_init_expression (tree t) |
29cf24ec | 6943 | { |
6944 | return (!type_unknown_p (t) | |
6945 | && !BRACE_ENCLOSED_INITIALIZER_P (t) | |
7e1f8be4 | 6946 | && is_static_init_expression (t) |
29cf24ec | 6947 | && !instantiation_dependent_expression_p (t)); |
6948 | } | |
6949 | ||
a050099a | 6950 | /* Finalize constexpr processing after parsing. */ |
6951 | ||
6952 | void | |
6953 | fini_constexpr (void) | |
6954 | { | |
6955 | /* The contexpr call and fundef copies tables are no longer needed. */ | |
6956 | constexpr_call_table = NULL; | |
6957 | fundef_copies_table = NULL; | |
6958 | } | |
6959 | ||
09b42213 | 6960 | #include "gt-cp-constexpr.h" |