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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; | |
977 | /* Parameter bindings environment. A TREE_LIST where each TREE_PURPOSE | |
978 | is a parameter _DECL and the TREE_VALUE is the value of the parameter. | |
979 | Note: This arrangement is made to accommodate the use of | |
980 | iterative_hash_template_arg (see pt.c). If you change this | |
981 | representation, also change the hash calculation in | |
982 | cxx_eval_call_expression. */ | |
983 | tree bindings; | |
984 | /* Result of the call. | |
985 | NULL means the call is being evaluated. | |
986 | error_mark_node means that the evaluation was erroneous; | |
987 | otherwise, the actuall value of the call. */ | |
988 | tree result; | |
989 | /* The hash of this call; we remember it here to avoid having to | |
990 | recalculate it when expanding the hash table. */ | |
991 | hashval_t hash; | |
919873c7 | 992 | /* Whether __builtin_is_constant_evaluated() should evaluate to true. */ |
1562c831 | 993 | bool manifestly_const_eval; |
09b42213 | 994 | }; |
995 | ||
b594087e | 996 | struct constexpr_call_hasher : ggc_ptr_hash<constexpr_call> |
09b42213 | 997 | { |
998 | static hashval_t hash (constexpr_call *); | |
999 | static bool equal (constexpr_call *, constexpr_call *); | |
cf72f34d | 1000 | }; |
1001 | ||
2a2770c6 | 1002 | enum constexpr_switch_state { |
1003 | /* Used when processing a switch for the first time by cxx_eval_switch_expr | |
1004 | and default: label for that switch has not been seen yet. */ | |
1005 | css_default_not_seen, | |
1006 | /* Used when processing a switch for the first time by cxx_eval_switch_expr | |
1007 | and default: label for that switch has been seen already. */ | |
1008 | css_default_seen, | |
1009 | /* Used when processing a switch for the second time by | |
1010 | cxx_eval_switch_expr, where default: label should match. */ | |
1011 | css_default_processing | |
1012 | }; | |
1013 | ||
cf72f34d | 1014 | /* The constexpr expansion context. CALL is the current function |
1015 | expansion, CTOR is the current aggregate initializer, OBJECT is the | |
1016 | object being initialized by CTOR, either a VAR_DECL or a _REF. VALUES | |
1017 | is a map of values of variables initialized within the expression. */ | |
1018 | ||
1019 | struct constexpr_ctx { | |
f9885b8a | 1020 | /* The innermost call we're evaluating. */ |
cf72f34d | 1021 | constexpr_call *call; |
f9885b8a | 1022 | /* Values for any temporaries or local variables within the |
1023 | constant-expression. */ | |
cf72f34d | 1024 | hash_map<tree,tree> *values; |
2631cb67 | 1025 | /* SAVE_EXPRs that we've seen within the current LOOP_EXPR. NULL if we |
1026 | aren't inside a loop. */ | |
d0782a7e | 1027 | vec<tree> *save_exprs; |
f9885b8a | 1028 | /* The CONSTRUCTOR we're currently building up for an aggregate |
1029 | initializer. */ | |
cf72f34d | 1030 | tree ctor; |
f9885b8a | 1031 | /* The object we're building the CONSTRUCTOR for. */ |
cf72f34d | 1032 | tree object; |
2a2770c6 | 1033 | /* If inside SWITCH_EXPR. */ |
1034 | constexpr_switch_state *css_state; | |
84f13b2f | 1035 | /* Number of cxx_eval_constant_expression calls (except skipped ones, |
1036 | on simple constants or location wrappers) encountered during current | |
1037 | cxx_eval_outermost_constant_expr call. */ | |
1038 | HOST_WIDE_INT *constexpr_ops_count; | |
1039 | ||
f9885b8a | 1040 | /* Whether we should error on a non-constant expression or fail quietly. */ |
f83e6885 | 1041 | bool quiet; |
f9885b8a | 1042 | /* Whether we are strictly conforming to constant expression rules or |
1043 | trying harder to get a constant value. */ | |
2055d27a | 1044 | bool strict; |
18d371d3 | 1045 | /* Whether __builtin_is_constant_evaluated () should be true. */ |
1562c831 | 1046 | bool manifestly_const_eval; |
cf72f34d | 1047 | }; |
09b42213 | 1048 | |
1049 | /* A table of all constexpr calls that have been evaluated by the | |
1050 | compiler in this translation unit. */ | |
1051 | ||
a050099a | 1052 | static GTY (()) hash_table<constexpr_call_hasher> *constexpr_call_table; |
09b42213 | 1053 | |
cf72f34d | 1054 | static tree cxx_eval_constant_expression (const constexpr_ctx *, tree, |
b2a43197 | 1055 | bool, bool *, bool *, tree * = NULL); |
09b42213 | 1056 | |
1057 | /* Compute a hash value for a constexpr call representation. */ | |
1058 | ||
1059 | inline hashval_t | |
1060 | constexpr_call_hasher::hash (constexpr_call *info) | |
1061 | { | |
1062 | return info->hash; | |
1063 | } | |
1064 | ||
1065 | /* Return true if the objects pointed to by P and Q represent calls | |
1066 | to the same constexpr function with the same arguments. | |
1067 | Otherwise, return false. */ | |
1068 | ||
1069 | bool | |
1070 | constexpr_call_hasher::equal (constexpr_call *lhs, constexpr_call *rhs) | |
1071 | { | |
1072 | tree lhs_bindings; | |
1073 | tree rhs_bindings; | |
1074 | if (lhs == rhs) | |
c751e2cd | 1075 | return true; |
1076 | if (lhs->hash != rhs->hash) | |
1077 | return false; | |
1562c831 | 1078 | if (lhs->manifestly_const_eval != rhs->manifestly_const_eval) |
919873c7 | 1079 | return false; |
09b42213 | 1080 | if (!constexpr_fundef_hasher::equal (lhs->fundef, rhs->fundef)) |
c751e2cd | 1081 | return false; |
09b42213 | 1082 | lhs_bindings = lhs->bindings; |
1083 | rhs_bindings = rhs->bindings; | |
1084 | while (lhs_bindings != NULL && rhs_bindings != NULL) | |
1085 | { | |
1086 | tree lhs_arg = TREE_VALUE (lhs_bindings); | |
1087 | tree rhs_arg = TREE_VALUE (rhs_bindings); | |
6d82dbcd | 1088 | gcc_assert (same_type_p (TREE_TYPE (lhs_arg), TREE_TYPE (rhs_arg))); |
09b42213 | 1089 | if (!cp_tree_equal (lhs_arg, rhs_arg)) |
c751e2cd | 1090 | return false; |
09b42213 | 1091 | lhs_bindings = TREE_CHAIN (lhs_bindings); |
1092 | rhs_bindings = TREE_CHAIN (rhs_bindings); | |
1093 | } | |
1094 | return lhs_bindings == rhs_bindings; | |
1095 | } | |
1096 | ||
1097 | /* Initialize the constexpr call table, if needed. */ | |
1098 | ||
1099 | static void | |
1100 | maybe_initialize_constexpr_call_table (void) | |
1101 | { | |
1102 | if (constexpr_call_table == NULL) | |
1103 | constexpr_call_table = hash_table<constexpr_call_hasher>::create_ggc (101); | |
1104 | } | |
1105 | ||
4f7ebe46 | 1106 | /* During constexpr CALL_EXPR evaluation, to avoid issues with sharing when |
1107 | a function happens to get called recursively, we unshare the callee | |
1108 | function's body and evaluate this unshared copy instead of evaluating the | |
1109 | original body. | |
1110 | ||
1111 | FUNDEF_COPIES_TABLE is a per-function freelist of these unshared function | |
1112 | copies. The underlying data structure of FUNDEF_COPIES_TABLE is a hash_map | |
a050099a | 1113 | that's keyed off of the original FUNCTION_DECL and whose value is a |
1114 | TREE_LIST of this function's unused copies awaiting reuse. | |
4f7ebe46 | 1115 | |
a050099a | 1116 | This is not GC-deletable to avoid GC affecting UID generation. */ |
4f7ebe46 | 1117 | |
a050099a | 1118 | static GTY(()) hash_map<tree, tree> *fundef_copies_table; |
4f7ebe46 | 1119 | |
1120 | /* Initialize FUNDEF_COPIES_TABLE if it's not initialized. */ | |
1121 | ||
1122 | static void | |
1123 | maybe_initialize_fundef_copies_table () | |
1124 | { | |
a050099a | 1125 | if (fundef_copies_table == NULL) |
1126 | fundef_copies_table = hash_map<tree,tree>::create_ggc (101); | |
4f7ebe46 | 1127 | } |
1128 | ||
1129 | /* Reuse a copy or create a new unshared copy of the function FUN. | |
886d5463 | 1130 | Return this copy. We use a TREE_LIST whose PURPOSE is body, VALUE |
1131 | is parms, TYPE is result. */ | |
4f7ebe46 | 1132 | |
a050099a | 1133 | static tree |
02d7a132 | 1134 | get_fundef_copy (constexpr_fundef *fundef) |
4f7ebe46 | 1135 | { |
1136 | maybe_initialize_fundef_copies_table (); | |
1137 | ||
a050099a | 1138 | tree copy; |
886d5463 | 1139 | bool existed; |
02d7a132 | 1140 | tree *slot = &fundef_copies_table->get_or_insert (fundef->decl, &existed); |
886d5463 | 1141 | |
1142 | if (!existed) | |
4f7ebe46 | 1143 | { |
886d5463 | 1144 | /* There is no cached function available, or in use. We can use |
1145 | the function directly. That the slot is now created records | |
1146 | that this function is now in use. */ | |
02d7a132 | 1147 | copy = build_tree_list (fundef->body, fundef->parms); |
1148 | TREE_TYPE (copy) = fundef->result; | |
886d5463 | 1149 | } |
1150 | else if (*slot == NULL_TREE) | |
1151 | { | |
1152 | /* We've already used the function itself, so make a copy. */ | |
a050099a | 1153 | copy = build_tree_list (NULL, NULL); |
02d7a132 | 1154 | tree saved_body = DECL_SAVED_TREE (fundef->decl); |
1155 | tree saved_parms = DECL_ARGUMENTS (fundef->decl); | |
1156 | tree saved_result = DECL_RESULT (fundef->decl); | |
1157 | tree saved_fn = current_function_decl; | |
1158 | DECL_SAVED_TREE (fundef->decl) = fundef->body; | |
1159 | DECL_ARGUMENTS (fundef->decl) = fundef->parms; | |
1160 | DECL_RESULT (fundef->decl) = fundef->result; | |
1161 | current_function_decl = fundef->decl; | |
1162 | TREE_PURPOSE (copy) = copy_fn (fundef->decl, TREE_VALUE (copy), | |
1163 | TREE_TYPE (copy)); | |
1164 | current_function_decl = saved_fn; | |
1165 | DECL_RESULT (fundef->decl) = saved_result; | |
1166 | DECL_ARGUMENTS (fundef->decl) = saved_parms; | |
1167 | DECL_SAVED_TREE (fundef->decl) = saved_body; | |
4f7ebe46 | 1168 | } |
1169 | else | |
1170 | { | |
886d5463 | 1171 | /* We have a cached function available. */ |
4f7ebe46 | 1172 | copy = *slot; |
a050099a | 1173 | *slot = TREE_CHAIN (copy); |
4f7ebe46 | 1174 | } |
1175 | ||
1176 | return copy; | |
1177 | } | |
1178 | ||
886d5463 | 1179 | /* Save the copy COPY of function FUN for later reuse by |
1180 | get_fundef_copy(). By construction, there will always be an entry | |
1181 | to find. */ | |
4f7ebe46 | 1182 | |
1183 | static void | |
a050099a | 1184 | save_fundef_copy (tree fun, tree copy) |
4f7ebe46 | 1185 | { |
886d5463 | 1186 | tree *slot = fundef_copies_table->get (fun); |
a050099a | 1187 | TREE_CHAIN (copy) = *slot; |
4f7ebe46 | 1188 | *slot = copy; |
1189 | } | |
1190 | ||
09b42213 | 1191 | /* We have an expression tree T that represents a call, either CALL_EXPR |
1192 | or AGGR_INIT_EXPR. Return the Nth argument. */ | |
1193 | ||
1194 | static inline tree | |
1195 | get_nth_callarg (tree t, int n) | |
1196 | { | |
1197 | switch (TREE_CODE (t)) | |
1198 | { | |
1199 | case CALL_EXPR: | |
1200 | return CALL_EXPR_ARG (t, n); | |
1201 | ||
1202 | case AGGR_INIT_EXPR: | |
1203 | return AGGR_INIT_EXPR_ARG (t, n); | |
1204 | ||
1205 | default: | |
1206 | gcc_unreachable (); | |
1207 | return NULL; | |
1208 | } | |
1209 | } | |
1210 | ||
09b42213 | 1211 | /* Attempt to evaluate T which represents a call to a builtin function. |
1212 | We assume here that all builtin functions evaluate to scalar types | |
1213 | represented by _CST nodes. */ | |
1214 | ||
1215 | static tree | |
f1c6af10 | 1216 | cxx_eval_builtin_function_call (const constexpr_ctx *ctx, tree t, tree fun, |
1227ba74 | 1217 | bool lval, |
09b42213 | 1218 | bool *non_constant_p, bool *overflow_p) |
1219 | { | |
1220 | const int nargs = call_expr_nargs (t); | |
1221 | tree *args = (tree *) alloca (nargs * sizeof (tree)); | |
1222 | tree new_call; | |
1223 | int i; | |
f1c6af10 | 1224 | |
1225 | /* Don't fold __builtin_constant_p within a constexpr function. */ | |
18d371d3 | 1226 | bool bi_const_p = DECL_IS_BUILTIN_CONSTANT_P (fun); |
efe6a40a | 1227 | |
0f5cec54 | 1228 | /* If we aren't requiring a constant expression, defer __builtin_constant_p |
1229 | in a constexpr function until we have values for the parameters. */ | |
efe6a40a | 1230 | if (bi_const_p |
4749c4ac | 1231 | && !ctx->manifestly_const_eval |
f1c6af10 | 1232 | && current_function_decl |
1233 | && DECL_DECLARED_CONSTEXPR_P (current_function_decl)) | |
09b42213 | 1234 | { |
f1c6af10 | 1235 | *non_constant_p = true; |
1236 | return t; | |
09b42213 | 1237 | } |
f1c6af10 | 1238 | |
18d371d3 | 1239 | /* For __builtin_is_constant_evaluated, defer it if not |
1562c831 | 1240 | ctx->manifestly_const_eval, otherwise fold it to true. */ |
a0e9bfbb | 1241 | if (fndecl_built_in_p (fun, CP_BUILT_IN_IS_CONSTANT_EVALUATED, |
1562c831 | 1242 | BUILT_IN_FRONTEND)) |
18d371d3 | 1243 | { |
1562c831 | 1244 | if (!ctx->manifestly_const_eval) |
18d371d3 | 1245 | { |
1246 | *non_constant_p = true; | |
1247 | return t; | |
1248 | } | |
1249 | return boolean_true_node; | |
1250 | } | |
1251 | ||
f1c6af10 | 1252 | /* Be permissive for arguments to built-ins; __builtin_constant_p should |
1253 | return constant false for a non-constant argument. */ | |
1254 | constexpr_ctx new_ctx = *ctx; | |
1255 | new_ctx.quiet = true; | |
f1c6af10 | 1256 | for (i = 0; i < nargs; ++i) |
efe6a40a | 1257 | { |
91b66c3c | 1258 | args[i] = CALL_EXPR_ARG (t, i); |
1259 | /* If builtin_valid_in_constant_expr_p is true, | |
1260 | potential_constant_expression_1 has not recursed into the arguments | |
1261 | of the builtin, verify it here. */ | |
1262 | if (!builtin_valid_in_constant_expr_p (fun) | |
1263 | || potential_constant_expression (args[i])) | |
4749c4ac | 1264 | { |
1265 | bool dummy1 = false, dummy2 = false; | |
1266 | args[i] = cxx_eval_constant_expression (&new_ctx, args[i], false, | |
1267 | &dummy1, &dummy2); | |
1268 | } | |
1269 | ||
efe6a40a | 1270 | if (bi_const_p) |
4749c4ac | 1271 | /* For __builtin_constant_p, fold all expressions with constant values |
efe6a40a | 1272 | even if they aren't C++ constant-expressions. */ |
4749c4ac | 1273 | args[i] = cp_fold_rvalue (args[i]); |
efe6a40a | 1274 | } |
f1c6af10 | 1275 | |
1276 | bool save_ffbcp = force_folding_builtin_constant_p; | |
1277 | force_folding_builtin_constant_p = true; | |
02d7a132 | 1278 | tree save_cur_fn = current_function_decl; |
1279 | /* Return name of ctx->call->fundef->decl for __builtin_FUNCTION (). */ | |
1280 | if (fndecl_built_in_p (fun, BUILT_IN_FUNCTION) | |
1281 | && ctx->call | |
1282 | && ctx->call->fundef) | |
1283 | current_function_decl = ctx->call->fundef->decl; | |
051eb924 | 1284 | new_call = fold_builtin_call_array (EXPR_LOCATION (t), TREE_TYPE (t), |
1285 | CALL_EXPR_FN (t), nargs, args); | |
02d7a132 | 1286 | current_function_decl = save_cur_fn; |
f1c6af10 | 1287 | force_folding_builtin_constant_p = save_ffbcp; |
051eb924 | 1288 | if (new_call == NULL) |
1289 | { | |
1290 | if (!*non_constant_p && !ctx->quiet) | |
1291 | { | |
2fb20ba2 | 1292 | /* Do not allow__builtin_unreachable in constexpr function. |
1293 | The __builtin_unreachable call with BUILTINS_LOCATION | |
1294 | comes from cp_maybe_instrument_return. */ | |
a0e9bfbb | 1295 | if (fndecl_built_in_p (fun, BUILT_IN_UNREACHABLE) |
2fb20ba2 | 1296 | && EXPR_LOCATION (t) == BUILTINS_LOCATION) |
5967b28b | 1297 | error ("%<constexpr%> call flows off the end of the function"); |
2fb20ba2 | 1298 | else |
1299 | { | |
1300 | new_call = build_call_array_loc (EXPR_LOCATION (t), TREE_TYPE (t), | |
1301 | CALL_EXPR_FN (t), nargs, args); | |
1302 | error ("%q+E is not a constant expression", new_call); | |
1303 | } | |
051eb924 | 1304 | } |
1305 | *non_constant_p = true; | |
1306 | return t; | |
1307 | } | |
1308 | ||
02d7a132 | 1309 | if (!potential_constant_expression (new_call)) |
051eb924 | 1310 | { |
1311 | if (!*non_constant_p && !ctx->quiet) | |
1312 | error ("%q+E is not a constant expression", new_call); | |
1313 | *non_constant_p = true; | |
1314 | return t; | |
1315 | } | |
1316 | ||
1317 | return cxx_eval_constant_expression (&new_ctx, new_call, lval, | |
1318 | non_constant_p, overflow_p); | |
09b42213 | 1319 | } |
1320 | ||
1321 | /* TEMP is the constant value of a temporary object of type TYPE. Adjust | |
1322 | the type of the value to match. */ | |
1323 | ||
1324 | static tree | |
1325 | adjust_temp_type (tree type, tree temp) | |
1326 | { | |
6d82dbcd | 1327 | if (same_type_p (TREE_TYPE (temp), type)) |
09b42213 | 1328 | return temp; |
1329 | /* Avoid wrapping an aggregate value in a NOP_EXPR. */ | |
1330 | if (TREE_CODE (temp) == CONSTRUCTOR) | |
c8f861a0 | 1331 | { |
1332 | /* build_constructor wouldn't retain various CONSTRUCTOR flags. */ | |
1333 | tree t = copy_node (temp); | |
1334 | TREE_TYPE (t) = type; | |
1335 | return t; | |
1336 | } | |
71c3d84e | 1337 | if (TREE_CODE (temp) == EMPTY_CLASS_EXPR) |
1338 | return build0 (EMPTY_CLASS_EXPR, type); | |
09b42213 | 1339 | gcc_assert (scalarish_type_p (type)); |
1340 | return cp_fold_convert (type, temp); | |
1341 | } | |
1342 | ||
e283bb4f | 1343 | /* Callback for walk_tree used by unshare_constructor. */ |
1344 | ||
1345 | static tree | |
1346 | find_constructor (tree *tp, int *walk_subtrees, void *) | |
1347 | { | |
1348 | if (TYPE_P (*tp)) | |
1349 | *walk_subtrees = 0; | |
1350 | if (TREE_CODE (*tp) == CONSTRUCTOR) | |
1351 | return *tp; | |
1352 | return NULL_TREE; | |
1353 | } | |
1354 | ||
1355 | /* If T is a CONSTRUCTOR or an expression that has a CONSTRUCTOR node as a | |
1356 | subexpression, return an unshared copy of T. Otherwise return T. */ | |
1357 | ||
33e6651d | 1358 | tree |
e283bb4f | 1359 | unshare_constructor (tree t) |
1360 | { | |
1361 | tree ctor = walk_tree (&t, find_constructor, NULL, NULL); | |
1362 | if (ctor != NULL_TREE) | |
1363 | return unshare_expr (t); | |
1364 | return t; | |
1365 | } | |
1366 | ||
09b42213 | 1367 | /* Subroutine of cxx_eval_call_expression. |
1368 | We are processing a call expression (either CALL_EXPR or | |
cf72f34d | 1369 | AGGR_INIT_EXPR) in the context of CTX. Evaluate |
09b42213 | 1370 | all arguments and bind their values to correspondings |
1371 | parameters, making up the NEW_CALL context. */ | |
1372 | ||
1373 | static void | |
cf72f34d | 1374 | cxx_bind_parameters_in_call (const constexpr_ctx *ctx, tree t, |
09b42213 | 1375 | constexpr_call *new_call, |
c8f6aeb1 | 1376 | bool *non_constant_p, bool *overflow_p, |
1377 | bool *non_constant_args) | |
09b42213 | 1378 | { |
1379 | const int nargs = call_expr_nargs (t); | |
1380 | tree fun = new_call->fundef->decl; | |
02d7a132 | 1381 | tree parms = new_call->fundef->parms; |
09b42213 | 1382 | int i; |
9c96033c | 1383 | tree *p = &new_call->bindings; |
09b42213 | 1384 | for (i = 0; i < nargs; ++i) |
1385 | { | |
1386 | tree x, arg; | |
1387 | tree type = parms ? TREE_TYPE (parms) : void_type_node; | |
09b42213 | 1388 | x = get_nth_callarg (t, i); |
cf72f34d | 1389 | /* For member function, the first argument is a pointer to the implied |
1390 | object. For a constructor, it might still be a dummy object, in | |
9c96033c | 1391 | which case we get the real argument from ctx. */ |
cf72f34d | 1392 | if (i == 0 && DECL_CONSTRUCTOR_P (fun) |
1393 | && is_dummy_object (x)) | |
1394 | { | |
1395 | x = ctx->object; | |
c017458d | 1396 | x = build_address (x); |
cf72f34d | 1397 | } |
02d7a132 | 1398 | if (TREE_ADDRESSABLE (type)) |
1399 | /* Undo convert_for_arg_passing work here. */ | |
1400 | x = convert_from_reference (x); | |
2e1c71c2 | 1401 | arg = cxx_eval_constant_expression (ctx, x, /*lval=*/false, |
b2a43197 | 1402 | non_constant_p, overflow_p); |
09b42213 | 1403 | /* Don't VERIFY_CONSTANT here. */ |
f83e6885 | 1404 | if (*non_constant_p && ctx->quiet) |
09b42213 | 1405 | return; |
1406 | /* Just discard ellipsis args after checking their constantitude. */ | |
1407 | if (!parms) | |
1408 | continue; | |
2ba934c7 | 1409 | |
1410 | if (!*non_constant_p) | |
1411 | { | |
24d5b4f0 | 1412 | /* Don't share a CONSTRUCTOR that might be changed. */ |
1413 | arg = unshare_constructor (arg); | |
2ba934c7 | 1414 | /* Make sure the binding has the same type as the parm. But |
1415 | only for constant args. */ | |
90ad495b | 1416 | if (!TYPE_REF_P (type)) |
2ba934c7 | 1417 | arg = adjust_temp_type (type, arg); |
1418 | if (!TREE_CONSTANT (arg)) | |
1419 | *non_constant_args = true; | |
1420 | *p = build_tree_list (parms, arg); | |
1421 | p = &TREE_CHAIN (*p); | |
1422 | } | |
09b42213 | 1423 | parms = TREE_CHAIN (parms); |
1424 | } | |
1425 | } | |
1426 | ||
1427 | /* Variables and functions to manage constexpr call expansion context. | |
1428 | These do not need to be marked for PCH or GC. */ | |
1429 | ||
1430 | /* FIXME remember and print actual constant arguments. */ | |
16fb756f | 1431 | static vec<tree> call_stack; |
09b42213 | 1432 | static int call_stack_tick; |
1433 | static int last_cx_error_tick; | |
1434 | ||
1435 | static bool | |
1436 | push_cx_call_context (tree call) | |
1437 | { | |
1438 | ++call_stack_tick; | |
1439 | if (!EXPR_HAS_LOCATION (call)) | |
1440 | SET_EXPR_LOCATION (call, input_location); | |
1441 | call_stack.safe_push (call); | |
1442 | if (call_stack.length () > (unsigned) max_constexpr_depth) | |
1443 | return false; | |
1444 | return true; | |
1445 | } | |
1446 | ||
1447 | static void | |
1448 | pop_cx_call_context (void) | |
1449 | { | |
1450 | ++call_stack_tick; | |
1451 | call_stack.pop (); | |
1452 | } | |
1453 | ||
1454 | vec<tree> | |
1455 | cx_error_context (void) | |
1456 | { | |
1457 | vec<tree> r = vNULL; | |
1458 | if (call_stack_tick != last_cx_error_tick | |
1459 | && !call_stack.is_empty ()) | |
1460 | r = call_stack; | |
1461 | last_cx_error_tick = call_stack_tick; | |
1462 | return r; | |
1463 | } | |
1464 | ||
732905bb | 1465 | /* Evaluate a call T to a GCC internal function when possible and return |
1466 | the evaluated result or, under the control of CTX, give an error, set | |
1467 | NON_CONSTANT_P, and return the unevaluated call T otherwise. */ | |
1468 | ||
1469 | static tree | |
1470 | cxx_eval_internal_function (const constexpr_ctx *ctx, tree t, | |
1471 | bool lval, | |
1472 | bool *non_constant_p, bool *overflow_p) | |
1473 | { | |
1474 | enum tree_code opcode = ERROR_MARK; | |
1475 | ||
1476 | switch (CALL_EXPR_IFN (t)) | |
1477 | { | |
1478 | case IFN_UBSAN_NULL: | |
1479 | case IFN_UBSAN_BOUNDS: | |
1480 | case IFN_UBSAN_VPTR: | |
3c77f69c | 1481 | case IFN_FALLTHROUGH: |
732905bb | 1482 | return void_node; |
1483 | ||
1484 | case IFN_ADD_OVERFLOW: | |
1485 | opcode = PLUS_EXPR; | |
1486 | break; | |
1487 | case IFN_SUB_OVERFLOW: | |
1488 | opcode = MINUS_EXPR; | |
1489 | break; | |
1490 | case IFN_MUL_OVERFLOW: | |
1491 | opcode = MULT_EXPR; | |
1492 | break; | |
1493 | ||
6e1b2ffb | 1494 | case IFN_LAUNDER: |
1495 | return cxx_eval_constant_expression (ctx, CALL_EXPR_ARG (t, 0), | |
1496 | false, non_constant_p, overflow_p); | |
1497 | ||
59409f09 | 1498 | case IFN_VEC_CONVERT: |
1499 | { | |
1500 | tree arg = cxx_eval_constant_expression (ctx, CALL_EXPR_ARG (t, 0), | |
1501 | false, non_constant_p, | |
1502 | overflow_p); | |
1503 | if (TREE_CODE (arg) == VECTOR_CST) | |
1504 | return fold_const_call (CFN_VEC_CONVERT, TREE_TYPE (t), arg); | |
1505 | else | |
1506 | { | |
1507 | *non_constant_p = true; | |
1508 | return t; | |
1509 | } | |
1510 | } | |
1511 | ||
732905bb | 1512 | default: |
1513 | if (!ctx->quiet) | |
d3a3cfb8 | 1514 | error_at (cp_expr_loc_or_loc (t, input_location), |
732905bb | 1515 | "call to internal function %qE", t); |
1516 | *non_constant_p = true; | |
1517 | return t; | |
1518 | } | |
1519 | ||
1520 | /* Evaluate constant arguments using OPCODE and return a complex | |
1521 | number containing the result and the overflow bit. */ | |
1522 | tree arg0 = cxx_eval_constant_expression (ctx, CALL_EXPR_ARG (t, 0), lval, | |
1523 | non_constant_p, overflow_p); | |
1524 | tree arg1 = cxx_eval_constant_expression (ctx, CALL_EXPR_ARG (t, 1), lval, | |
1525 | non_constant_p, overflow_p); | |
1526 | ||
1527 | if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST) | |
1528 | { | |
d3a3cfb8 | 1529 | location_t loc = cp_expr_loc_or_loc (t, input_location); |
732905bb | 1530 | tree type = TREE_TYPE (TREE_TYPE (t)); |
1531 | tree result = fold_binary_loc (loc, opcode, type, | |
1532 | fold_convert_loc (loc, type, arg0), | |
1533 | fold_convert_loc (loc, type, arg1)); | |
1534 | tree ovf | |
1535 | = build_int_cst (type, arith_overflowed_p (opcode, type, arg0, arg1)); | |
1536 | /* Reset TREE_OVERFLOW to avoid warnings for the overflow. */ | |
1537 | if (TREE_OVERFLOW (result)) | |
1538 | TREE_OVERFLOW (result) = 0; | |
1539 | ||
1540 | return build_complex (TREE_TYPE (t), result, ovf); | |
1541 | } | |
1542 | ||
1543 | *non_constant_p = true; | |
1544 | return t; | |
1545 | } | |
1546 | ||
165d0d5b | 1547 | /* Clean CONSTRUCTOR_NO_CLEARING from CTOR and its sub-aggregates. */ |
79cdb4f5 | 1548 | |
1549 | static void | |
1550 | clear_no_implicit_zero (tree ctor) | |
1551 | { | |
165d0d5b | 1552 | if (CONSTRUCTOR_NO_CLEARING (ctor)) |
79cdb4f5 | 1553 | { |
165d0d5b | 1554 | CONSTRUCTOR_NO_CLEARING (ctor) = false; |
79cdb4f5 | 1555 | tree elt; unsigned HOST_WIDE_INT idx; |
1556 | FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), idx, elt) | |
1557 | if (TREE_CODE (elt) == CONSTRUCTOR) | |
1558 | clear_no_implicit_zero (elt); | |
1559 | } | |
1560 | } | |
1561 | ||
09b42213 | 1562 | /* Subroutine of cxx_eval_constant_expression. |
1563 | Evaluate the call expression tree T in the context of OLD_CALL expression | |
1564 | evaluation. */ | |
1565 | ||
1566 | static tree | |
cf72f34d | 1567 | cxx_eval_call_expression (const constexpr_ctx *ctx, tree t, |
1227ba74 | 1568 | bool lval, |
09b42213 | 1569 | bool *non_constant_p, bool *overflow_p) |
1570 | { | |
d3a3cfb8 | 1571 | location_t loc = cp_expr_loc_or_loc (t, input_location); |
09b42213 | 1572 | tree fun = get_function_named_in_call (t); |
919873c7 | 1573 | constexpr_call new_call |
1562c831 | 1574 | = { NULL, NULL, NULL, 0, ctx->manifestly_const_eval }; |
09b42213 | 1575 | bool depth_ok; |
1576 | ||
6b71bdb4 | 1577 | if (fun == NULL_TREE) |
732905bb | 1578 | return cxx_eval_internal_function (ctx, t, lval, |
1579 | non_constant_p, overflow_p); | |
6b71bdb4 | 1580 | |
09b42213 | 1581 | if (TREE_CODE (fun) != FUNCTION_DECL) |
1582 | { | |
1583 | /* Might be a constexpr function pointer. */ | |
f83e6885 | 1584 | fun = cxx_eval_constant_expression (ctx, fun, |
1227ba74 | 1585 | /*lval*/false, non_constant_p, |
b2a43197 | 1586 | overflow_p); |
09b42213 | 1587 | STRIP_NOPS (fun); |
1588 | if (TREE_CODE (fun) == ADDR_EXPR) | |
1589 | fun = TREE_OPERAND (fun, 0); | |
9a97d94a | 1590 | /* For TARGET_VTABLE_USES_DESCRIPTORS targets, there is no |
1591 | indirection, the called expression is a pointer into the | |
1592 | virtual table which should contain FDESC_EXPR. Extract the | |
1593 | FUNCTION_DECL from there. */ | |
1594 | else if (TARGET_VTABLE_USES_DESCRIPTORS | |
1595 | && TREE_CODE (fun) == POINTER_PLUS_EXPR | |
1596 | && TREE_CODE (TREE_OPERAND (fun, 0)) == ADDR_EXPR | |
1597 | && TREE_CODE (TREE_OPERAND (fun, 1)) == INTEGER_CST) | |
1598 | { | |
1599 | tree d = TREE_OPERAND (TREE_OPERAND (fun, 0), 0); | |
1600 | if (VAR_P (d) | |
1601 | && DECL_VTABLE_OR_VTT_P (d) | |
1602 | && TREE_CODE (TREE_TYPE (d)) == ARRAY_TYPE | |
1603 | && TREE_TYPE (TREE_TYPE (d)) == vtable_entry_type | |
1604 | && DECL_INITIAL (d) | |
1605 | && TREE_CODE (DECL_INITIAL (d)) == CONSTRUCTOR) | |
1606 | { | |
1607 | tree i = int_const_binop (TRUNC_DIV_EXPR, TREE_OPERAND (fun, 1), | |
1608 | TYPE_SIZE_UNIT (vtable_entry_type)); | |
1609 | HOST_WIDE_INT idx = find_array_ctor_elt (DECL_INITIAL (d), i); | |
1610 | if (idx >= 0) | |
1611 | { | |
1612 | tree fdesc | |
1613 | = (*CONSTRUCTOR_ELTS (DECL_INITIAL (d)))[idx].value; | |
1614 | if (TREE_CODE (fdesc) == FDESC_EXPR | |
1615 | && integer_zerop (TREE_OPERAND (fdesc, 1))) | |
1616 | fun = TREE_OPERAND (fdesc, 0); | |
1617 | } | |
1618 | } | |
1619 | } | |
09b42213 | 1620 | } |
1621 | if (TREE_CODE (fun) != FUNCTION_DECL) | |
1622 | { | |
f83e6885 | 1623 | if (!ctx->quiet && !*non_constant_p) |
5967b28b | 1624 | error_at (loc, "expression %qE does not designate a %<constexpr%> " |
09b42213 | 1625 | "function", fun); |
1626 | *non_constant_p = true; | |
1627 | return t; | |
1628 | } | |
1629 | if (DECL_CLONED_FUNCTION_P (fun)) | |
1630 | fun = DECL_CLONED_FUNCTION (fun); | |
6b71bdb4 | 1631 | |
1632 | if (is_ubsan_builtin_p (fun)) | |
1633 | return void_node; | |
1634 | ||
a0e9bfbb | 1635 | if (fndecl_built_in_p (fun)) |
f1c6af10 | 1636 | return cxx_eval_builtin_function_call (ctx, t, fun, |
1227ba74 | 1637 | lval, non_constant_p, overflow_p); |
09b42213 | 1638 | if (!DECL_DECLARED_CONSTEXPR_P (fun)) |
1639 | { | |
f83e6885 | 1640 | if (!ctx->quiet) |
09b42213 | 1641 | { |
1dcd84cf | 1642 | if (!lambda_static_thunk_p (fun)) |
5967b28b | 1643 | error_at (loc, "call to non-%<constexpr%> function %qD", fun); |
09b42213 | 1644 | explain_invalid_constexpr_fn (fun); |
1645 | } | |
1646 | *non_constant_p = true; | |
1647 | return t; | |
1648 | } | |
1649 | ||
9ebe2ea3 | 1650 | constexpr_ctx new_ctx = *ctx; |
1651 | if (DECL_CONSTRUCTOR_P (fun) && !ctx->object | |
1652 | && TREE_CODE (t) == AGGR_INIT_EXPR) | |
1653 | { | |
1654 | /* We want to have an initialization target for an AGGR_INIT_EXPR. | |
1655 | If we don't already have one in CTX, use the AGGR_INIT_EXPR_SLOT. */ | |
1656 | new_ctx.object = AGGR_INIT_EXPR_SLOT (t); | |
1657 | tree ctor = new_ctx.ctor = build_constructor (DECL_CONTEXT (fun), NULL); | |
165d0d5b | 1658 | CONSTRUCTOR_NO_CLEARING (ctor) = true; |
9ebe2ea3 | 1659 | ctx->values->put (new_ctx.object, ctor); |
1660 | ctx = &new_ctx; | |
1661 | } | |
1662 | ||
09b42213 | 1663 | /* Shortcut trivial constructor/op=. */ |
1664 | if (trivial_fn_p (fun)) | |
1665 | { | |
9ebe2ea3 | 1666 | tree init = NULL_TREE; |
09b42213 | 1667 | if (call_expr_nargs (t) == 2) |
9ebe2ea3 | 1668 | init = convert_from_reference (get_nth_callarg (t, 1)); |
09b42213 | 1669 | else if (TREE_CODE (t) == AGGR_INIT_EXPR |
1670 | && AGGR_INIT_ZERO_FIRST (t)) | |
9ebe2ea3 | 1671 | init = build_zero_init (DECL_CONTEXT (fun), NULL_TREE, false); |
1672 | if (init) | |
1673 | { | |
1674 | tree op = get_nth_callarg (t, 0); | |
1675 | if (is_dummy_object (op)) | |
1676 | op = ctx->object; | |
1677 | else | |
1678 | op = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (op)), op); | |
1679 | tree set = build2 (MODIFY_EXPR, TREE_TYPE (op), op, init); | |
0ce12360 | 1680 | new_ctx.call = &new_call; |
1681 | return cxx_eval_constant_expression (&new_ctx, set, lval, | |
9ebe2ea3 | 1682 | non_constant_p, overflow_p); |
1683 | } | |
09b42213 | 1684 | } |
1685 | ||
8afcf831 | 1686 | /* We can't defer instantiating the function any longer. */ |
1687 | if (!DECL_INITIAL (fun) | |
1688 | && DECL_TEMPLOID_INSTANTIATION (fun)) | |
1689 | { | |
31db86df | 1690 | location_t save_loc = input_location; |
1691 | input_location = loc; | |
8afcf831 | 1692 | ++function_depth; |
1693 | instantiate_decl (fun, /*defer_ok*/false, /*expl_inst*/false); | |
1694 | --function_depth; | |
31db86df | 1695 | input_location = save_loc; |
8afcf831 | 1696 | } |
1697 | ||
09b42213 | 1698 | /* If in direct recursive call, optimize definition search. */ |
0ce12360 | 1699 | if (ctx && ctx->call && ctx->call->fundef && ctx->call->fundef->decl == fun) |
cf72f34d | 1700 | new_call.fundef = ctx->call->fundef; |
09b42213 | 1701 | else |
1702 | { | |
1703 | new_call.fundef = retrieve_constexpr_fundef (fun); | |
d2a9b1c1 | 1704 | if (new_call.fundef == NULL || new_call.fundef->body == NULL |
1705 | || fun == current_function_decl) | |
09b42213 | 1706 | { |
f83e6885 | 1707 | if (!ctx->quiet) |
09b42213 | 1708 | { |
d2a9b1c1 | 1709 | /* We need to check for current_function_decl here in case we're |
1710 | being called during cp_fold_function, because at that point | |
1711 | DECL_INITIAL is set properly and we have a fundef but we | |
1712 | haven't lowered invisirefs yet (c++/70344). */ | |
1713 | if (DECL_INITIAL (fun) == error_mark_node | |
1714 | || fun == current_function_decl) | |
a0efa758 | 1715 | error_at (loc, "%qD called in a constant expression before its " |
1716 | "definition is complete", fun); | |
1717 | else if (DECL_INITIAL (fun)) | |
09b42213 | 1718 | { |
33603066 | 1719 | /* The definition of fun was somehow unsuitable. But pretend |
1720 | that lambda static thunks don't exist. */ | |
1721 | if (!lambda_static_thunk_p (fun)) | |
1722 | error_at (loc, "%qD called in a constant expression", fun); | |
09b42213 | 1723 | explain_invalid_constexpr_fn (fun); |
1724 | } | |
1725 | else | |
1726 | error_at (loc, "%qD used before its definition", fun); | |
1727 | } | |
1728 | *non_constant_p = true; | |
1729 | return t; | |
1730 | } | |
1731 | } | |
9c96033c | 1732 | |
c8f6aeb1 | 1733 | bool non_constant_args = false; |
cf72f34d | 1734 | cxx_bind_parameters_in_call (ctx, t, &new_call, |
c8f6aeb1 | 1735 | non_constant_p, overflow_p, &non_constant_args); |
09b42213 | 1736 | if (*non_constant_p) |
1737 | return t; | |
1738 | ||
1739 | depth_ok = push_cx_call_context (t); | |
1740 | ||
c8f6aeb1 | 1741 | tree result = NULL_TREE; |
09b42213 | 1742 | |
c8f6aeb1 | 1743 | constexpr_call *entry = NULL; |
167a09fb | 1744 | if (depth_ok && !non_constant_args && ctx->strict) |
09b42213 | 1745 | { |
919873c7 | 1746 | new_call.hash = constexpr_fundef_hasher::hash (new_call.fundef); |
1747 | new_call.hash | |
1748 | = iterative_hash_template_arg (new_call.bindings, new_call.hash); | |
1749 | new_call.hash | |
1562c831 | 1750 | = iterative_hash_object (ctx->manifestly_const_eval, new_call.hash); |
c8f6aeb1 | 1751 | |
1752 | /* If we have seen this call before, we are done. */ | |
1753 | maybe_initialize_constexpr_call_table (); | |
1754 | constexpr_call **slot | |
1755 | = constexpr_call_table->find_slot (&new_call, INSERT); | |
1756 | entry = *slot; | |
1757 | if (entry == NULL) | |
1758 | { | |
1759 | /* We need to keep a pointer to the entry, not just the slot, as the | |
1760 | slot can move in the call to cxx_eval_builtin_function_call. */ | |
1761 | *slot = entry = ggc_alloc<constexpr_call> (); | |
1762 | *entry = new_call; | |
1763 | } | |
2ba934c7 | 1764 | /* Calls that are in progress have their result set to NULL, |
c8f6aeb1 | 1765 | so that we can detect circular dependencies. */ |
1766 | else if (entry->result == NULL) | |
1767 | { | |
1768 | if (!ctx->quiet) | |
1769 | error ("call has circular dependency"); | |
1770 | *non_constant_p = true; | |
1771 | entry->result = result = error_mark_node; | |
1772 | } | |
1773 | else | |
1774 | result = entry->result; | |
09b42213 | 1775 | } |
1776 | ||
1777 | if (!depth_ok) | |
1778 | { | |
f83e6885 | 1779 | if (!ctx->quiet) |
5967b28b | 1780 | error ("%<constexpr%> evaluation depth exceeds maximum of %d (use " |
f91d3a9d | 1781 | "%<-fconstexpr-depth=%> to increase the maximum)", |
09b42213 | 1782 | max_constexpr_depth); |
1783 | *non_constant_p = true; | |
c8f6aeb1 | 1784 | result = error_mark_node; |
09b42213 | 1785 | } |
1786 | else | |
1787 | { | |
ab099088 | 1788 | if (result && result != error_mark_node) |
1789 | /* OK */; | |
1790 | else if (!DECL_SAVED_TREE (fun)) | |
1791 | { | |
1792 | /* When at_eof >= 2, cgraph has started throwing away | |
1793 | DECL_SAVED_TREE, so fail quietly. FIXME we get here because of | |
1794 | late code generation for VEC_INIT_EXPR, which needs to be | |
1795 | completely reconsidered. */ | |
1796 | gcc_assert (at_eof >= 2 && ctx->quiet); | |
1797 | *non_constant_p = true; | |
1798 | } | |
1799 | else | |
cf72f34d | 1800 | { |
4f7ebe46 | 1801 | tree body, parms, res; |
88a59139 | 1802 | |
4f7ebe46 | 1803 | /* Reuse or create a new unshared copy of this function's body. */ |
02d7a132 | 1804 | tree copy = get_fundef_copy (new_call.fundef); |
a050099a | 1805 | body = TREE_PURPOSE (copy); |
1806 | parms = TREE_VALUE (copy); | |
1807 | res = TREE_TYPE (copy); | |
88a59139 | 1808 | |
1809 | /* Associate the bindings with the remapped parms. */ | |
1810 | tree bound = new_call.bindings; | |
1811 | tree remapped = parms; | |
1812 | while (bound) | |
9c96033c | 1813 | { |
88a59139 | 1814 | tree oparm = TREE_PURPOSE (bound); |
1815 | tree arg = TREE_VALUE (bound); | |
1816 | gcc_assert (DECL_NAME (remapped) == DECL_NAME (oparm)); | |
5898f0d7 | 1817 | /* Don't share a CONSTRUCTOR that might be changed. */ |
e283bb4f | 1818 | arg = unshare_constructor (arg); |
88a59139 | 1819 | ctx->values->put (remapped, arg); |
1820 | bound = TREE_CHAIN (bound); | |
1821 | remapped = DECL_CHAIN (remapped); | |
9c96033c | 1822 | } |
88a59139 | 1823 | /* Add the RESULT_DECL to the values map, too. */ |
1824 | tree slot = NULL_TREE; | |
1825 | if (DECL_BY_REFERENCE (res)) | |
9c96033c | 1826 | { |
88a59139 | 1827 | slot = AGGR_INIT_EXPR_SLOT (t); |
1828 | tree addr = build_address (slot); | |
1829 | addr = build_nop (TREE_TYPE (res), addr); | |
1830 | ctx->values->put (res, addr); | |
1831 | ctx->values->put (slot, NULL_TREE); | |
1832 | } | |
1833 | else | |
1834 | ctx->values->put (res, NULL_TREE); | |
9c96033c | 1835 | |
4f7ebe46 | 1836 | /* Track the callee's evaluated SAVE_EXPRs so that we can forget |
1837 | their values after the call. */ | |
1838 | constexpr_ctx ctx_with_save_exprs = *ctx; | |
d0782a7e | 1839 | auto_vec<tree, 10> save_exprs; |
4f7ebe46 | 1840 | ctx_with_save_exprs.save_exprs = &save_exprs; |
43b7271d | 1841 | ctx_with_save_exprs.call = &new_call; |
4f7ebe46 | 1842 | |
88a59139 | 1843 | tree jump_target = NULL_TREE; |
4f7ebe46 | 1844 | cxx_eval_constant_expression (&ctx_with_save_exprs, body, |
88a59139 | 1845 | lval, non_constant_p, overflow_p, |
1846 | &jump_target); | |
9c96033c | 1847 | |
88a59139 | 1848 | if (DECL_CONSTRUCTOR_P (fun)) |
1849 | /* This can be null for a subobject constructor call, in | |
1850 | which case what we care about is the initialization | |
1851 | side-effects rather than the value. We could get at the | |
1852 | value by evaluating *this, but we don't bother; there's | |
1853 | no need to put such a call in the hash table. */ | |
1854 | result = lval ? ctx->object : ctx->ctor; | |
1855 | else if (VOID_TYPE_P (TREE_TYPE (res))) | |
1856 | result = void_node; | |
1857 | else | |
1858 | { | |
1859 | result = *ctx->values->get (slot ? slot : res); | |
1860 | if (result == NULL_TREE && !*non_constant_p) | |
9c96033c | 1861 | { |
88a59139 | 1862 | if (!ctx->quiet) |
5967b28b | 1863 | error ("%<constexpr%> call flows off the end " |
88a59139 | 1864 | "of the function"); |
1865 | *non_constant_p = true; | |
9c96033c | 1866 | } |
9c96033c | 1867 | } |
88a59139 | 1868 | |
4f7ebe46 | 1869 | /* Forget the saved values of the callee's SAVE_EXPRs. */ |
d0782a7e | 1870 | unsigned int i; |
1871 | tree save_expr; | |
1872 | FOR_EACH_VEC_ELT (save_exprs, i, save_expr) | |
1873 | ctx_with_save_exprs.values->remove (save_expr); | |
4f7ebe46 | 1874 | |
88a59139 | 1875 | /* Remove the parms/result from the values map. Is it worth |
1876 | bothering to do this when the map itself is only live for | |
1877 | one constexpr evaluation? If so, maybe also clear out | |
1878 | other vars from call, maybe in BIND_EXPR handling? */ | |
1879 | ctx->values->remove (res); | |
1880 | if (slot) | |
1881 | ctx->values->remove (slot); | |
1882 | for (tree parm = parms; parm; parm = TREE_CHAIN (parm)) | |
1883 | ctx->values->remove (parm); | |
4f7ebe46 | 1884 | |
1885 | /* Make the unshared function copy we used available for re-use. */ | |
1886 | save_fundef_copy (fun, copy); | |
cf72f34d | 1887 | } |
9c96033c | 1888 | |
09b42213 | 1889 | if (result == error_mark_node) |
1890 | *non_constant_p = true; | |
c3f376bf | 1891 | if (*non_constant_p || *overflow_p) |
c8f6aeb1 | 1892 | result = error_mark_node; |
88a59139 | 1893 | else if (!result) |
9c96033c | 1894 | result = void_node; |
c8f6aeb1 | 1895 | if (entry) |
1896 | entry->result = result; | |
09b42213 | 1897 | } |
1898 | ||
c6d97004 | 1899 | /* The result of a constexpr function must be completely initialized. */ |
1900 | if (TREE_CODE (result) == CONSTRUCTOR) | |
79cdb4f5 | 1901 | clear_no_implicit_zero (result); |
c6d97004 | 1902 | |
09b42213 | 1903 | pop_cx_call_context (); |
e283bb4f | 1904 | return unshare_constructor (result); |
09b42213 | 1905 | } |
1906 | ||
1907 | /* FIXME speed this up, it's taking 16% of compile time on sieve testcase. */ | |
1908 | ||
1909 | bool | |
1910 | reduced_constant_expression_p (tree t) | |
1911 | { | |
a34934c2 | 1912 | if (t == NULL_TREE) |
1913 | return false; | |
1914 | ||
09b42213 | 1915 | switch (TREE_CODE (t)) |
1916 | { | |
1917 | case PTRMEM_CST: | |
1918 | /* Even if we can't lower this yet, it's constant. */ | |
1919 | return true; | |
1920 | ||
1921 | case CONSTRUCTOR: | |
1922 | /* And we need to handle PTRMEM_CST wrapped in a CONSTRUCTOR. */ | |
56da7fe6 | 1923 | tree idx, val, field; unsigned HOST_WIDE_INT i; |
165d0d5b | 1924 | if (CONSTRUCTOR_NO_CLEARING (t)) |
c4210852 | 1925 | { |
1926 | if (TREE_CODE (TREE_TYPE (t)) == VECTOR_TYPE) | |
1927 | /* An initialized vector would have a VECTOR_CST. */ | |
1928 | return false; | |
1929 | else | |
1930 | field = next_initializable_field (TYPE_FIELDS (TREE_TYPE (t))); | |
1931 | } | |
56da7fe6 | 1932 | else |
1933 | field = NULL_TREE; | |
1934 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (t), i, idx, val) | |
ce4ffd9e | 1935 | { |
a34934c2 | 1936 | /* If VAL is null, we're in the middle of initializing this |
1937 | element. */ | |
56da7fe6 | 1938 | if (!reduced_constant_expression_p (val)) |
ce4ffd9e | 1939 | return false; |
56da7fe6 | 1940 | if (field) |
1941 | { | |
1942 | if (idx != field) | |
1943 | return false; | |
1944 | field = next_initializable_field (DECL_CHAIN (field)); | |
1945 | } | |
ce4ffd9e | 1946 | } |
56da7fe6 | 1947 | if (field) |
1948 | return false; | |
165d0d5b | 1949 | else if (CONSTRUCTOR_NO_CLEARING (t)) |
56da7fe6 | 1950 | /* All the fields are initialized. */ |
165d0d5b | 1951 | CONSTRUCTOR_NO_CLEARING (t) = false; |
09b42213 | 1952 | return true; |
1953 | ||
1954 | default: | |
1955 | /* FIXME are we calling this too much? */ | |
1956 | return initializer_constant_valid_p (t, TREE_TYPE (t)) != NULL_TREE; | |
1957 | } | |
1958 | } | |
1959 | ||
1960 | /* Some expressions may have constant operands but are not constant | |
941fafa5 | 1961 | themselves, such as 1/0. Call this function to check for that |
1962 | condition. | |
09b42213 | 1963 | |
1964 | We only call this in places that require an arithmetic constant, not in | |
1965 | places where we might have a non-constant expression that can be a | |
1966 | component of a constant expression, such as the address of a constexpr | |
1967 | variable that might be dereferenced later. */ | |
1968 | ||
1969 | static bool | |
1970 | verify_constant (tree t, bool allow_non_constant, bool *non_constant_p, | |
1971 | bool *overflow_p) | |
1972 | { | |
1973 | if (!*non_constant_p && !reduced_constant_expression_p (t)) | |
1974 | { | |
1975 | if (!allow_non_constant) | |
1976 | error ("%q+E is not a constant expression", t); | |
1977 | *non_constant_p = true; | |
1978 | } | |
1979 | if (TREE_OVERFLOW_P (t)) | |
1980 | { | |
1981 | if (!allow_non_constant) | |
1982 | { | |
1983 | permerror (input_location, "overflow in constant expression"); | |
1984 | /* If we're being permissive (and are in an enforcing | |
1985 | context), ignore the overflow. */ | |
1986 | if (flag_permissive) | |
1987 | return *non_constant_p; | |
1988 | } | |
1989 | *overflow_p = true; | |
1990 | } | |
1991 | return *non_constant_p; | |
1992 | } | |
1993 | ||
2b035ffe | 1994 | /* Check whether the shift operation with code CODE and type TYPE on LHS |
1995 | and RHS is undefined. If it is, give an error with an explanation, | |
1996 | and return true; return false otherwise. */ | |
1997 | ||
1998 | static bool | |
1999 | cxx_eval_check_shift_p (location_t loc, const constexpr_ctx *ctx, | |
2000 | enum tree_code code, tree type, tree lhs, tree rhs) | |
2001 | { | |
2002 | if ((code != LSHIFT_EXPR && code != RSHIFT_EXPR) | |
2003 | || TREE_CODE (lhs) != INTEGER_CST | |
2004 | || TREE_CODE (rhs) != INTEGER_CST) | |
2005 | return false; | |
2006 | ||
2007 | tree lhstype = TREE_TYPE (lhs); | |
2008 | unsigned HOST_WIDE_INT uprec = TYPE_PRECISION (TREE_TYPE (lhs)); | |
2009 | ||
2010 | /* [expr.shift] The behavior is undefined if the right operand | |
2011 | is negative, or greater than or equal to the length in bits | |
2012 | of the promoted left operand. */ | |
2013 | if (tree_int_cst_sgn (rhs) == -1) | |
2014 | { | |
2015 | if (!ctx->quiet) | |
91d87e22 | 2016 | permerror (loc, "right operand of shift expression %q+E is negative", |
2017 | build2_loc (loc, code, type, lhs, rhs)); | |
2018 | return (!flag_permissive || ctx->quiet); | |
2b035ffe | 2019 | } |
2020 | if (compare_tree_int (rhs, uprec) >= 0) | |
2021 | { | |
2022 | if (!ctx->quiet) | |
91d87e22 | 2023 | permerror (loc, "right operand of shift expression %q+E is >= than " |
2024 | "the precision of the left operand", | |
2025 | build2_loc (loc, code, type, lhs, rhs)); | |
2026 | return (!flag_permissive || ctx->quiet); | |
2b035ffe | 2027 | } |
2028 | ||
2029 | /* The value of E1 << E2 is E1 left-shifted E2 bit positions; [...] | |
2030 | if E1 has a signed type and non-negative value, and E1x2^E2 is | |
2031 | representable in the corresponding unsigned type of the result type, | |
2032 | then that value, converted to the result type, is the resulting value; | |
1170ee75 | 2033 | otherwise, the behavior is undefined. |
2034 | For C++2a: | |
2035 | The value of E1 << E2 is the unique value congruent to E1 x 2^E2 modulo | |
2036 | 2^N, where N is the range exponent of the type of the result. */ | |
2037 | if (code == LSHIFT_EXPR | |
2038 | && !TYPE_UNSIGNED (lhstype) | |
2039 | && cxx_dialect >= cxx11 | |
2040 | && cxx_dialect < cxx2a) | |
2b035ffe | 2041 | { |
2042 | if (tree_int_cst_sgn (lhs) == -1) | |
2043 | { | |
2044 | if (!ctx->quiet) | |
91d87e22 | 2045 | permerror (loc, |
2046 | "left operand of shift expression %q+E is negative", | |
2047 | build2_loc (loc, code, type, lhs, rhs)); | |
2048 | return (!flag_permissive || ctx->quiet); | |
2b035ffe | 2049 | } |
2050 | /* For signed x << y the following: | |
2051 | (unsigned) x >> ((prec (lhs) - 1) - y) | |
2052 | if > 1, is undefined. The right-hand side of this formula | |
2053 | is the highest bit of the LHS that can be set (starting from 0), | |
2054 | so that the shift doesn't overflow. We then right-shift the LHS | |
2055 | to see whether any other bit is set making the original shift | |
2056 | undefined -- the result is not representable in the corresponding | |
2057 | unsigned type. */ | |
2058 | tree t = build_int_cst (unsigned_type_node, uprec - 1); | |
2059 | t = fold_build2 (MINUS_EXPR, unsigned_type_node, t, rhs); | |
2060 | tree ulhs = fold_convert (unsigned_type_for (lhstype), lhs); | |
2061 | t = fold_build2 (RSHIFT_EXPR, TREE_TYPE (ulhs), ulhs, t); | |
2062 | if (tree_int_cst_lt (integer_one_node, t)) | |
2063 | { | |
2064 | if (!ctx->quiet) | |
91d87e22 | 2065 | permerror (loc, "shift expression %q+E overflows", |
2066 | build2_loc (loc, code, type, lhs, rhs)); | |
2067 | return (!flag_permissive || ctx->quiet); | |
2b035ffe | 2068 | } |
2069 | } | |
2070 | return false; | |
2071 | } | |
2072 | ||
09b42213 | 2073 | /* Subroutine of cxx_eval_constant_expression. |
2074 | Attempt to reduce the unary expression tree T to a compile time value. | |
2075 | If successful, return the value. Otherwise issue a diagnostic | |
2076 | and return error_mark_node. */ | |
2077 | ||
2078 | static tree | |
cf72f34d | 2079 | cxx_eval_unary_expression (const constexpr_ctx *ctx, tree t, |
c8f6aeb1 | 2080 | bool /*lval*/, |
09b42213 | 2081 | bool *non_constant_p, bool *overflow_p) |
2082 | { | |
2083 | tree r; | |
2084 | tree orig_arg = TREE_OPERAND (t, 0); | |
c8f6aeb1 | 2085 | tree arg = cxx_eval_constant_expression (ctx, orig_arg, /*lval*/false, |
2086 | non_constant_p, overflow_p); | |
09b42213 | 2087 | VERIFY_CONSTANT (arg); |
93add516 | 2088 | location_t loc = EXPR_LOCATION (t); |
2089 | enum tree_code code = TREE_CODE (t); | |
2090 | tree type = TREE_TYPE (t); | |
2091 | r = fold_unary_loc (loc, code, type, arg); | |
2092 | if (r == NULL_TREE) | |
2093 | { | |
2094 | if (arg == orig_arg) | |
2095 | r = t; | |
2096 | else | |
2097 | r = build1_loc (loc, code, type, arg); | |
2098 | } | |
09b42213 | 2099 | VERIFY_CONSTANT (r); |
2100 | return r; | |
2101 | } | |
2102 | ||
46fad8d5 | 2103 | /* Helper function for cxx_eval_binary_expression. Try to optimize |
2104 | original POINTER_PLUS_EXPR T, LHS p+ RHS, return NULL_TREE if the | |
2105 | generic folding should be used. */ | |
2106 | ||
2107 | static tree | |
2108 | cxx_fold_pointer_plus_expression (const constexpr_ctx *ctx, tree t, | |
2109 | tree lhs, tree rhs, bool *non_constant_p, | |
2110 | bool *overflow_p) | |
2111 | { | |
2112 | STRIP_NOPS (lhs); | |
2113 | if (TREE_CODE (lhs) != ADDR_EXPR) | |
2114 | return NULL_TREE; | |
2115 | ||
2116 | lhs = TREE_OPERAND (lhs, 0); | |
2117 | ||
2118 | /* &A[i] p+ j => &A[i + j] */ | |
2119 | if (TREE_CODE (lhs) == ARRAY_REF | |
2120 | && TREE_CODE (TREE_OPERAND (lhs, 1)) == INTEGER_CST | |
2121 | && TREE_CODE (rhs) == INTEGER_CST | |
2122 | && TYPE_SIZE_UNIT (TREE_TYPE (lhs)) | |
2123 | && TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (lhs))) == INTEGER_CST) | |
2124 | { | |
2125 | tree orig_type = TREE_TYPE (t); | |
2126 | location_t loc = EXPR_LOCATION (t); | |
2127 | tree type = TREE_TYPE (lhs); | |
2128 | ||
2129 | t = fold_convert_loc (loc, ssizetype, TREE_OPERAND (lhs, 1)); | |
2130 | tree nelts = array_type_nelts_top (TREE_TYPE (TREE_OPERAND (lhs, 0))); | |
2131 | nelts = cxx_eval_constant_expression (ctx, nelts, false, non_constant_p, | |
2132 | overflow_p); | |
2133 | if (*non_constant_p) | |
2134 | return NULL_TREE; | |
2135 | /* Don't fold an out-of-bound access. */ | |
2136 | if (!tree_int_cst_le (t, nelts)) | |
2137 | return NULL_TREE; | |
2138 | rhs = cp_fold_convert (ssizetype, rhs); | |
2139 | /* Don't fold if rhs can't be divided exactly by TYPE_SIZE_UNIT. | |
2140 | constexpr int A[1]; ... (char *)&A[0] + 1 */ | |
2141 | if (!integer_zerop (fold_build2_loc (loc, TRUNC_MOD_EXPR, sizetype, | |
2142 | rhs, TYPE_SIZE_UNIT (type)))) | |
2143 | return NULL_TREE; | |
2144 | /* Make sure to treat the second operand of POINTER_PLUS_EXPR | |
2145 | as signed. */ | |
2146 | rhs = fold_build2_loc (loc, EXACT_DIV_EXPR, ssizetype, rhs, | |
2147 | TYPE_SIZE_UNIT (type)); | |
2148 | t = size_binop_loc (loc, PLUS_EXPR, rhs, t); | |
2149 | t = build4_loc (loc, ARRAY_REF, type, TREE_OPERAND (lhs, 0), | |
2150 | t, NULL_TREE, NULL_TREE); | |
2151 | t = cp_build_addr_expr (t, tf_warning_or_error); | |
2152 | t = cp_fold_convert (orig_type, t); | |
2153 | return cxx_eval_constant_expression (ctx, t, /*lval*/false, | |
2154 | non_constant_p, overflow_p); | |
2155 | } | |
2156 | ||
2157 | return NULL_TREE; | |
2158 | } | |
2159 | ||
09b42213 | 2160 | /* Subroutine of cxx_eval_constant_expression. |
2161 | Like cxx_eval_unary_expression, except for binary expressions. */ | |
2162 | ||
2163 | static tree | |
cf72f34d | 2164 | cxx_eval_binary_expression (const constexpr_ctx *ctx, tree t, |
c8f6aeb1 | 2165 | bool /*lval*/, |
09b42213 | 2166 | bool *non_constant_p, bool *overflow_p) |
2167 | { | |
f7ef5392 | 2168 | tree r = NULL_TREE; |
09b42213 | 2169 | tree orig_lhs = TREE_OPERAND (t, 0); |
2170 | tree orig_rhs = TREE_OPERAND (t, 1); | |
2171 | tree lhs, rhs; | |
c8f6aeb1 | 2172 | lhs = cxx_eval_constant_expression (ctx, orig_lhs, /*lval*/false, |
b2a43197 | 2173 | non_constant_p, overflow_p); |
6d6737d9 | 2174 | /* Don't VERIFY_CONSTANT here, it's unnecessary and will break pointer |
2175 | subtraction. */ | |
2176 | if (*non_constant_p) | |
2177 | return t; | |
c8f6aeb1 | 2178 | rhs = cxx_eval_constant_expression (ctx, orig_rhs, /*lval*/false, |
b2a43197 | 2179 | non_constant_p, overflow_p); |
6d6737d9 | 2180 | if (*non_constant_p) |
2181 | return t; | |
93add516 | 2182 | |
2183 | location_t loc = EXPR_LOCATION (t); | |
2184 | enum tree_code code = TREE_CODE (t); | |
2185 | tree type = TREE_TYPE (t); | |
f7ef5392 | 2186 | |
2187 | if (code == EQ_EXPR || code == NE_EXPR) | |
2188 | { | |
2189 | bool is_code_eq = (code == EQ_EXPR); | |
2190 | ||
2191 | if (TREE_CODE (lhs) == PTRMEM_CST | |
2192 | && TREE_CODE (rhs) == PTRMEM_CST) | |
e9f29fe5 | 2193 | { |
2194 | tree lmem = PTRMEM_CST_MEMBER (lhs); | |
2195 | tree rmem = PTRMEM_CST_MEMBER (rhs); | |
2196 | bool eq; | |
2197 | if (TREE_CODE (lmem) == TREE_CODE (rmem) | |
2198 | && TREE_CODE (lmem) == FIELD_DECL | |
2199 | && TREE_CODE (DECL_CONTEXT (lmem)) == UNION_TYPE | |
2200 | && same_type_p (DECL_CONTEXT (lmem), | |
2201 | DECL_CONTEXT (rmem))) | |
2202 | /* If both refer to (possibly different) members of the same union | |
2203 | (12.3), they compare equal. */ | |
2204 | eq = true; | |
2205 | else | |
2206 | eq = cp_tree_equal (lhs, rhs); | |
2207 | r = constant_boolean_node (eq == is_code_eq, type); | |
2208 | } | |
f7ef5392 | 2209 | else if ((TREE_CODE (lhs) == PTRMEM_CST |
2210 | || TREE_CODE (rhs) == PTRMEM_CST) | |
2211 | && (null_member_pointer_value_p (lhs) | |
2212 | || null_member_pointer_value_p (rhs))) | |
2213 | r = constant_boolean_node (!is_code_eq, type); | |
f31f4e9c | 2214 | else if (TREE_CODE (lhs) == PTRMEM_CST) |
2215 | lhs = cplus_expand_constant (lhs); | |
2216 | else if (TREE_CODE (rhs) == PTRMEM_CST) | |
2217 | rhs = cplus_expand_constant (rhs); | |
f7ef5392 | 2218 | } |
cb768824 | 2219 | if (code == POINTER_PLUS_EXPR && !*non_constant_p |
2220 | && integer_zerop (lhs) && !integer_zerop (rhs)) | |
2221 | { | |
2222 | if (!ctx->quiet) | |
2223 | error ("arithmetic involving a null pointer in %qE", lhs); | |
2b1749c4 | 2224 | *non_constant_p = true; |
cb768824 | 2225 | return t; |
2226 | } | |
46fad8d5 | 2227 | else if (code == POINTER_PLUS_EXPR) |
2228 | r = cxx_fold_pointer_plus_expression (ctx, t, lhs, rhs, non_constant_p, | |
2229 | overflow_p); | |
f7ef5392 | 2230 | |
2231 | if (r == NULL_TREE) | |
2232 | r = fold_binary_loc (loc, code, type, lhs, rhs); | |
2233 | ||
93add516 | 2234 | if (r == NULL_TREE) |
2235 | { | |
2236 | if (lhs == orig_lhs && rhs == orig_rhs) | |
2237 | r = t; | |
2238 | else | |
2239 | r = build2_loc (loc, code, type, lhs, rhs); | |
2240 | } | |
2b035ffe | 2241 | else if (cxx_eval_check_shift_p (loc, ctx, code, type, lhs, rhs)) |
2242 | *non_constant_p = true; | |
6d6737d9 | 2243 | /* Don't VERIFY_CONSTANT if this might be dealing with a pointer to |
2244 | a local array in a constexpr function. */ | |
d03fa520 | 2245 | bool ptr = INDIRECT_TYPE_P (TREE_TYPE (lhs)); |
35f2c28f | 2246 | if (!ptr) |
aae7465c | 2247 | VERIFY_CONSTANT (r); |
09b42213 | 2248 | return r; |
2249 | } | |
2250 | ||
2251 | /* Subroutine of cxx_eval_constant_expression. | |
2252 | Attempt to evaluate condition expressions. Dead branches are not | |
2253 | looked into. */ | |
2254 | ||
2255 | static tree | |
cf72f34d | 2256 | cxx_eval_conditional_expression (const constexpr_ctx *ctx, tree t, |
1227ba74 | 2257 | bool lval, |
00f21715 | 2258 | bool *non_constant_p, bool *overflow_p, |
2259 | tree *jump_target) | |
09b42213 | 2260 | { |
cf72f34d | 2261 | tree val = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), |
c8f6aeb1 | 2262 | /*lval*/false, |
b2a43197 | 2263 | non_constant_p, overflow_p); |
09b42213 | 2264 | VERIFY_CONSTANT (val); |
2265 | /* Don't VERIFY_CONSTANT the other operands. */ | |
2266 | if (integer_zerop (val)) | |
02d7a132 | 2267 | val = TREE_OPERAND (t, 2); |
2268 | else | |
2269 | val = TREE_OPERAND (t, 1); | |
2270 | if (TREE_CODE (t) == IF_STMT && !val) | |
2271 | val = void_node; | |
2272 | return cxx_eval_constant_expression (ctx, val, lval, non_constant_p, | |
2273 | overflow_p, jump_target); | |
09b42213 | 2274 | } |
2275 | ||
31595caf | 2276 | /* Subroutine of cxx_eval_constant_expression. |
2277 | Attempt to evaluate vector condition expressions. Unlike | |
2278 | cxx_eval_conditional_expression, VEC_COND_EXPR acts like a normal | |
2279 | ternary arithmetics operation, where all 3 arguments have to be | |
2280 | evaluated as constants and then folding computes the result from | |
2281 | them. */ | |
2282 | ||
2283 | static tree | |
2284 | cxx_eval_vector_conditional_expression (const constexpr_ctx *ctx, tree t, | |
2285 | bool *non_constant_p, bool *overflow_p) | |
2286 | { | |
2287 | tree arg1 = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), | |
2288 | /*lval*/false, | |
2289 | non_constant_p, overflow_p); | |
2290 | VERIFY_CONSTANT (arg1); | |
2291 | tree arg2 = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), | |
2292 | /*lval*/false, | |
2293 | non_constant_p, overflow_p); | |
2294 | VERIFY_CONSTANT (arg2); | |
2295 | tree arg3 = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 2), | |
2296 | /*lval*/false, | |
2297 | non_constant_p, overflow_p); | |
2298 | VERIFY_CONSTANT (arg3); | |
2299 | location_t loc = EXPR_LOCATION (t); | |
2300 | tree type = TREE_TYPE (t); | |
2301 | tree r = fold_ternary_loc (loc, VEC_COND_EXPR, type, arg1, arg2, arg3); | |
2302 | if (r == NULL_TREE) | |
2303 | { | |
2304 | if (arg1 == TREE_OPERAND (t, 0) | |
2305 | && arg2 == TREE_OPERAND (t, 1) | |
2306 | && arg3 == TREE_OPERAND (t, 2)) | |
2307 | r = t; | |
2308 | else | |
2309 | r = build3_loc (loc, VEC_COND_EXPR, type, arg1, arg2, arg3); | |
2310 | } | |
2311 | VERIFY_CONSTANT (r); | |
2312 | return r; | |
2313 | } | |
2314 | ||
7963b19d | 2315 | /* Returns less than, equal to, or greater than zero if KEY is found to be |
2316 | less than, to match, or to be greater than the constructor_elt's INDEX. */ | |
2317 | ||
2318 | static int | |
2319 | array_index_cmp (tree key, tree index) | |
2320 | { | |
2321 | gcc_assert (TREE_CODE (key) == INTEGER_CST); | |
2322 | ||
2323 | switch (TREE_CODE (index)) | |
2324 | { | |
2325 | case INTEGER_CST: | |
2326 | return tree_int_cst_compare (key, index); | |
2327 | case RANGE_EXPR: | |
2328 | { | |
2329 | tree lo = TREE_OPERAND (index, 0); | |
2330 | tree hi = TREE_OPERAND (index, 1); | |
2331 | if (tree_int_cst_lt (key, lo)) | |
2332 | return -1; | |
2333 | else if (tree_int_cst_lt (hi, key)) | |
2334 | return 1; | |
2335 | else | |
2336 | return 0; | |
2337 | } | |
2338 | default: | |
2339 | gcc_unreachable (); | |
2340 | } | |
2341 | } | |
2342 | ||
2343 | /* Returns the index of the constructor_elt of ARY which matches DINDEX, or -1 | |
2344 | if none. If INSERT is true, insert a matching element rather than fail. */ | |
2345 | ||
2346 | static HOST_WIDE_INT | |
9a97d94a | 2347 | find_array_ctor_elt (tree ary, tree dindex, bool insert) |
7963b19d | 2348 | { |
2349 | if (tree_int_cst_sgn (dindex) < 0) | |
2350 | return -1; | |
2351 | ||
2352 | unsigned HOST_WIDE_INT i = tree_to_uhwi (dindex); | |
2353 | vec<constructor_elt, va_gc> *elts = CONSTRUCTOR_ELTS (ary); | |
2354 | unsigned HOST_WIDE_INT len = vec_safe_length (elts); | |
2355 | ||
2356 | unsigned HOST_WIDE_INT end = len; | |
2357 | unsigned HOST_WIDE_INT begin = 0; | |
2358 | ||
2359 | /* If the last element of the CONSTRUCTOR has its own index, we can assume | |
2360 | that the same is true of the other elements and index directly. */ | |
2361 | if (end > 0) | |
2362 | { | |
e99466d6 | 2363 | tree cindex = (*elts)[end - 1].index; |
7963b19d | 2364 | if (TREE_CODE (cindex) == INTEGER_CST |
e99466d6 | 2365 | && compare_tree_int (cindex, end - 1) == 0) |
7963b19d | 2366 | { |
2367 | if (i < end) | |
2368 | return i; | |
2369 | else | |
2370 | begin = end; | |
2371 | } | |
2372 | } | |
2373 | ||
2374 | /* Otherwise, find a matching index by means of a binary search. */ | |
2375 | while (begin != end) | |
2376 | { | |
2377 | unsigned HOST_WIDE_INT middle = (begin + end) / 2; | |
f0b916c7 | 2378 | constructor_elt &elt = (*elts)[middle]; |
2379 | tree idx = elt.index; | |
7963b19d | 2380 | |
f0b916c7 | 2381 | int cmp = array_index_cmp (dindex, idx); |
7963b19d | 2382 | if (cmp < 0) |
2383 | end = middle; | |
2384 | else if (cmp > 0) | |
2385 | begin = middle + 1; | |
2386 | else | |
f0b916c7 | 2387 | { |
2388 | if (insert && TREE_CODE (idx) == RANGE_EXPR) | |
2389 | { | |
2390 | /* We need to split the range. */ | |
2391 | constructor_elt e; | |
2392 | tree lo = TREE_OPERAND (idx, 0); | |
2393 | tree hi = TREE_OPERAND (idx, 1); | |
e99466d6 | 2394 | tree value = elt.value; |
2395 | dindex = fold_convert (sizetype, dindex); | |
f0b916c7 | 2396 | if (tree_int_cst_lt (lo, dindex)) |
2397 | { | |
2398 | /* There are still some lower elts; shorten the range. */ | |
2399 | tree new_hi = int_const_binop (MINUS_EXPR, dindex, | |
2400 | size_one_node); | |
2401 | if (tree_int_cst_equal (lo, new_hi)) | |
2402 | /* Only one element left, no longer a range. */ | |
2403 | elt.index = lo; | |
2404 | else | |
2405 | TREE_OPERAND (idx, 1) = new_hi; | |
2406 | /* Append the element we want to insert. */ | |
2407 | ++middle; | |
2408 | e.index = dindex; | |
e99466d6 | 2409 | e.value = unshare_constructor (value); |
f0b916c7 | 2410 | vec_safe_insert (CONSTRUCTOR_ELTS (ary), middle, e); |
2411 | } | |
2412 | else | |
2413 | /* No lower elts, the range elt is now ours. */ | |
2414 | elt.index = dindex; | |
2415 | ||
2416 | if (tree_int_cst_lt (dindex, hi)) | |
2417 | { | |
2418 | /* There are still some higher elts; append a range. */ | |
2419 | tree new_lo = int_const_binop (PLUS_EXPR, dindex, | |
2420 | size_one_node); | |
2421 | if (tree_int_cst_equal (new_lo, hi)) | |
2422 | e.index = hi; | |
2423 | else | |
2424 | e.index = build2 (RANGE_EXPR, sizetype, new_lo, hi); | |
e99466d6 | 2425 | e.value = unshare_constructor (value); |
2426 | vec_safe_insert (CONSTRUCTOR_ELTS (ary), middle + 1, e); | |
f0b916c7 | 2427 | } |
2428 | } | |
2429 | return middle; | |
2430 | } | |
7963b19d | 2431 | } |
2432 | ||
2433 | if (insert) | |
2434 | { | |
2435 | constructor_elt e = { dindex, NULL_TREE }; | |
2436 | vec_safe_insert (CONSTRUCTOR_ELTS (ary), end, e); | |
2437 | return end; | |
2438 | } | |
2439 | ||
2440 | return -1; | |
2441 | } | |
2442 | ||
40df9099 | 2443 | /* Under the control of CTX, issue a detailed diagnostic for |
2444 | an out-of-bounds subscript INDEX into the expression ARRAY. */ | |
2445 | ||
2446 | static void | |
2447 | diag_array_subscript (const constexpr_ctx *ctx, tree array, tree index) | |
2448 | { | |
2449 | if (!ctx->quiet) | |
2450 | { | |
2451 | tree arraytype = TREE_TYPE (array); | |
2452 | ||
2453 | /* Convert the unsigned array subscript to a signed integer to avoid | |
2454 | printing huge numbers for small negative values. */ | |
2455 | tree sidx = fold_convert (ssizetype, index); | |
2456 | if (DECL_P (array)) | |
2457 | { | |
d7d265db | 2458 | if (TYPE_DOMAIN (arraytype)) |
2459 | error ("array subscript value %qE is outside the bounds " | |
2460 | "of array %qD of type %qT", sidx, array, arraytype); | |
2461 | else | |
2462 | error ("non-zero array subscript %qE is used with array %qD of " | |
2463 | "type %qT with unknown bounds", sidx, array, arraytype); | |
40df9099 | 2464 | inform (DECL_SOURCE_LOCATION (array), "declared here"); |
2465 | } | |
d7d265db | 2466 | else if (TYPE_DOMAIN (arraytype)) |
40df9099 | 2467 | error ("array subscript value %qE is outside the bounds " |
2468 | "of array type %qT", sidx, arraytype); | |
d7d265db | 2469 | else |
2470 | error ("non-zero array subscript %qE is used with array of type %qT " | |
2471 | "with unknown bounds", sidx, arraytype); | |
40df9099 | 2472 | } |
2473 | } | |
7963b19d | 2474 | |
51f0c7e2 | 2475 | /* Return the number of elements for TYPE (which is an ARRAY_TYPE or |
2476 | a VECTOR_TYPE). */ | |
2477 | ||
2478 | static tree | |
2479 | get_array_or_vector_nelts (const constexpr_ctx *ctx, tree type, | |
2480 | bool *non_constant_p, bool *overflow_p) | |
2481 | { | |
2482 | tree nelts; | |
2483 | if (TREE_CODE (type) == ARRAY_TYPE) | |
2484 | { | |
2485 | if (TYPE_DOMAIN (type)) | |
2486 | nelts = array_type_nelts_top (type); | |
2487 | else | |
2488 | nelts = size_zero_node; | |
2489 | } | |
2490 | else if (VECTOR_TYPE_P (type)) | |
2491 | nelts = size_int (TYPE_VECTOR_SUBPARTS (type)); | |
2492 | else | |
2493 | gcc_unreachable (); | |
2494 | ||
2495 | /* For VLAs, the number of elements won't be an integer constant. */ | |
2496 | nelts = cxx_eval_constant_expression (ctx, nelts, false, | |
2497 | non_constant_p, overflow_p); | |
2498 | return nelts; | |
2499 | } | |
2500 | ||
92fe8840 | 2501 | /* Extract element INDEX consisting of CHARS_PER_ELT chars from |
2502 | STRING_CST STRING. */ | |
2503 | ||
2504 | static tree | |
2505 | extract_string_elt (tree string, unsigned chars_per_elt, unsigned index) | |
2506 | { | |
2507 | tree type = cv_unqualified (TREE_TYPE (TREE_TYPE (string))); | |
2508 | tree r; | |
2509 | ||
2510 | if (chars_per_elt == 1) | |
2511 | r = build_int_cst (type, TREE_STRING_POINTER (string)[index]); | |
2512 | else | |
2513 | { | |
2514 | const unsigned char *ptr | |
2515 | = ((const unsigned char *)TREE_STRING_POINTER (string) | |
2516 | + index * chars_per_elt); | |
2517 | r = native_interpret_expr (type, ptr, chars_per_elt); | |
2518 | } | |
2519 | return r; | |
2520 | } | |
2521 | ||
09b42213 | 2522 | /* Subroutine of cxx_eval_constant_expression. |
2523 | Attempt to reduce a reference to an array slot. */ | |
2524 | ||
2525 | static tree | |
cf72f34d | 2526 | cxx_eval_array_reference (const constexpr_ctx *ctx, tree t, |
1227ba74 | 2527 | bool lval, |
09b42213 | 2528 | bool *non_constant_p, bool *overflow_p) |
2529 | { | |
2530 | tree oldary = TREE_OPERAND (t, 0); | |
cf72f34d | 2531 | tree ary = cxx_eval_constant_expression (ctx, oldary, |
1227ba74 | 2532 | lval, |
b2a43197 | 2533 | non_constant_p, overflow_p); |
09b42213 | 2534 | tree index, oldidx; |
cf3cefc9 | 2535 | HOST_WIDE_INT i = 0; |
2536 | tree elem_type = NULL_TREE; | |
2537 | unsigned len = 0, elem_nchars = 1; | |
09b42213 | 2538 | if (*non_constant_p) |
2539 | return t; | |
2540 | oldidx = TREE_OPERAND (t, 1); | |
cf72f34d | 2541 | index = cxx_eval_constant_expression (ctx, oldidx, |
f83e6885 | 2542 | false, |
b2a43197 | 2543 | non_constant_p, overflow_p); |
09b42213 | 2544 | VERIFY_CONSTANT (index); |
cf3cefc9 | 2545 | if (!lval) |
09b42213 | 2546 | { |
cf3cefc9 | 2547 | elem_type = TREE_TYPE (TREE_TYPE (ary)); |
2548 | if (TREE_CODE (ary) == VIEW_CONVERT_EXPR | |
2549 | && VECTOR_TYPE_P (TREE_TYPE (TREE_OPERAND (ary, 0))) | |
2550 | && TREE_TYPE (t) == TREE_TYPE (TREE_TYPE (TREE_OPERAND (ary, 0)))) | |
2551 | ary = TREE_OPERAND (ary, 0); | |
2552 | if (TREE_CODE (ary) == CONSTRUCTOR) | |
2553 | len = CONSTRUCTOR_NELTS (ary); | |
2554 | else if (TREE_CODE (ary) == STRING_CST) | |
2555 | { | |
2556 | elem_nchars = (TYPE_PRECISION (elem_type) | |
2557 | / TYPE_PRECISION (char_type_node)); | |
2558 | len = (unsigned) TREE_STRING_LENGTH (ary) / elem_nchars; | |
2559 | } | |
2560 | else if (TREE_CODE (ary) == VECTOR_CST) | |
f08ee65f | 2561 | /* We don't create variable-length VECTOR_CSTs. */ |
2562 | len = VECTOR_CST_NELTS (ary).to_constant (); | |
cf3cefc9 | 2563 | else |
2564 | { | |
2565 | /* We can't do anything with other tree codes, so use | |
2566 | VERIFY_CONSTANT to complain and fail. */ | |
2567 | VERIFY_CONSTANT (ary); | |
2568 | gcc_unreachable (); | |
2569 | } | |
aed8dc7f | 2570 | |
cf3cefc9 | 2571 | if (!tree_fits_shwi_p (index) |
2572 | || (i = tree_to_shwi (index)) < 0) | |
2573 | { | |
2574 | diag_array_subscript (ctx, ary, index); | |
2575 | *non_constant_p = true; | |
2576 | return t; | |
2577 | } | |
7963b19d | 2578 | } |
2579 | ||
51f0c7e2 | 2580 | tree nelts = get_array_or_vector_nelts (ctx, TREE_TYPE (ary), non_constant_p, |
2581 | overflow_p); | |
ce6a6978 | 2582 | VERIFY_CONSTANT (nelts); |
0acc6340 | 2583 | if ((lval |
2584 | ? !tree_int_cst_le (index, nelts) | |
2585 | : !tree_int_cst_lt (index, nelts)) | |
2586 | || tree_int_cst_sgn (index) < 0) | |
ce6a6978 | 2587 | { |
40df9099 | 2588 | diag_array_subscript (ctx, ary, index); |
ce6a6978 | 2589 | *non_constant_p = true; |
2590 | return t; | |
2591 | } | |
2592 | ||
cf3cefc9 | 2593 | if (lval && ary == oldary && index == oldidx) |
2594 | return t; | |
2595 | else if (lval) | |
2596 | return build4 (ARRAY_REF, TREE_TYPE (t), ary, index, NULL, NULL); | |
2597 | ||
7963b19d | 2598 | bool found; |
2599 | if (TREE_CODE (ary) == CONSTRUCTOR) | |
2600 | { | |
2601 | HOST_WIDE_INT ix = find_array_ctor_elt (ary, index); | |
2602 | found = (ix >= 0); | |
2603 | if (found) | |
2604 | i = ix; | |
aed8dc7f | 2605 | } |
7963b19d | 2606 | else |
2607 | found = (i < len); | |
aed8dc7f | 2608 | |
14869f28 | 2609 | if (found) |
2610 | { | |
2611 | tree r; | |
2612 | if (TREE_CODE (ary) == CONSTRUCTOR) | |
2613 | r = (*CONSTRUCTOR_ELTS (ary))[i].value; | |
2614 | else if (TREE_CODE (ary) == VECTOR_CST) | |
2615 | r = VECTOR_CST_ELT (ary, i); | |
14869f28 | 2616 | else |
92fe8840 | 2617 | r = extract_string_elt (ary, elem_nchars, i); |
2618 | ||
14869f28 | 2619 | if (r) |
2620 | /* Don't VERIFY_CONSTANT here. */ | |
2621 | return r; | |
09b42213 | 2622 | |
14869f28 | 2623 | /* Otherwise the element doesn't have a value yet. */ |
09b42213 | 2624 | } |
aed8dc7f | 2625 | |
14869f28 | 2626 | /* Not found. */ |
2627 | ||
2628 | if (TREE_CODE (ary) == CONSTRUCTOR | |
165d0d5b | 2629 | && CONSTRUCTOR_NO_CLEARING (ary)) |
09b42213 | 2630 | { |
14869f28 | 2631 | /* 'ary' is part of the aggregate initializer we're currently |
2632 | building; if there's no initializer for this element yet, | |
2633 | that's an error. */ | |
2634 | if (!ctx->quiet) | |
2635 | error ("accessing uninitialized array element"); | |
2636 | *non_constant_p = true; | |
2637 | return t; | |
09b42213 | 2638 | } |
14869f28 | 2639 | |
2640 | /* If it's within the array bounds but doesn't have an explicit | |
2641 | initializer, it's value-initialized. */ | |
2642 | tree val = build_value_init (elem_type, tf_warning_or_error); | |
2643 | return cxx_eval_constant_expression (ctx, val, lval, non_constant_p, | |
2644 | overflow_p); | |
09b42213 | 2645 | } |
2646 | ||
2647 | /* Subroutine of cxx_eval_constant_expression. | |
2648 | Attempt to reduce a field access of a value of class type. */ | |
2649 | ||
2650 | static tree | |
cf72f34d | 2651 | cxx_eval_component_reference (const constexpr_ctx *ctx, tree t, |
1227ba74 | 2652 | bool lval, |
09b42213 | 2653 | bool *non_constant_p, bool *overflow_p) |
2654 | { | |
2655 | unsigned HOST_WIDE_INT i; | |
2656 | tree field; | |
2657 | tree value; | |
2658 | tree part = TREE_OPERAND (t, 1); | |
2659 | tree orig_whole = TREE_OPERAND (t, 0); | |
cf72f34d | 2660 | tree whole = cxx_eval_constant_expression (ctx, orig_whole, |
1227ba74 | 2661 | lval, |
b2a43197 | 2662 | non_constant_p, overflow_p); |
7ab20d7c | 2663 | if (INDIRECT_REF_P (whole) |
2b1749c4 | 2664 | && integer_zerop (TREE_OPERAND (whole, 0))) |
2665 | { | |
2666 | if (!ctx->quiet) | |
2667 | error ("dereferencing a null pointer in %qE", orig_whole); | |
2668 | *non_constant_p = true; | |
2669 | return t; | |
2670 | } | |
cb768824 | 2671 | |
f16ed232 | 2672 | if (TREE_CODE (whole) == PTRMEM_CST) |
2673 | whole = cplus_expand_constant (whole); | |
09b42213 | 2674 | if (whole == orig_whole) |
2675 | return t; | |
1227ba74 | 2676 | if (lval) |
09b42213 | 2677 | return fold_build3 (COMPONENT_REF, TREE_TYPE (t), |
2678 | whole, part, NULL_TREE); | |
2679 | /* Don't VERIFY_CONSTANT here; we only want to check that we got a | |
2680 | CONSTRUCTOR. */ | |
2681 | if (!*non_constant_p && TREE_CODE (whole) != CONSTRUCTOR) | |
2682 | { | |
f83e6885 | 2683 | if (!ctx->quiet) |
09b42213 | 2684 | error ("%qE is not a constant expression", orig_whole); |
2685 | *non_constant_p = true; | |
2686 | } | |
2687 | if (DECL_MUTABLE_P (part)) | |
2688 | { | |
f83e6885 | 2689 | if (!ctx->quiet) |
09b42213 | 2690 | error ("mutable %qD is not usable in a constant expression", part); |
2691 | *non_constant_p = true; | |
2692 | } | |
2693 | if (*non_constant_p) | |
2694 | return t; | |
a4360e57 | 2695 | bool pmf = TYPE_PTRMEMFUNC_P (TREE_TYPE (whole)); |
09b42213 | 2696 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (whole), i, field, value) |
2697 | { | |
a4360e57 | 2698 | /* Use name match for PMF fields, as a variant will have a |
2699 | different FIELD_DECL with a different type. */ | |
2700 | if (pmf ? DECL_NAME (field) == DECL_NAME (part) | |
2701 | : field == part) | |
9c96033c | 2702 | { |
2703 | if (value) | |
2704 | return value; | |
2705 | else | |
2706 | /* We're in the middle of initializing it. */ | |
2707 | break; | |
2708 | } | |
09b42213 | 2709 | } |
2710 | if (TREE_CODE (TREE_TYPE (whole)) == UNION_TYPE | |
2711 | && CONSTRUCTOR_NELTS (whole) > 0) | |
2712 | { | |
2713 | /* DR 1188 says we don't have to deal with this. */ | |
f83e6885 | 2714 | if (!ctx->quiet) |
09b42213 | 2715 | error ("accessing %qD member instead of initialized %qD member in " |
2716 | "constant expression", part, CONSTRUCTOR_ELT (whole, 0)->index); | |
2717 | *non_constant_p = true; | |
2718 | return t; | |
2719 | } | |
2720 | ||
f894a056 | 2721 | /* We only create a CONSTRUCTOR for a subobject when we modify it, so empty |
2722 | classes never get represented; throw together a value now. */ | |
cd5a9ed1 | 2723 | if (is_really_empty_class (TREE_TYPE (t), /*ignore_vptr*/false)) |
f894a056 | 2724 | return build_constructor (TREE_TYPE (t), NULL); |
2725 | ||
a4360e57 | 2726 | gcc_assert (DECL_CONTEXT (part) == TYPE_MAIN_VARIANT (TREE_TYPE (whole))); |
2727 | ||
165d0d5b | 2728 | if (CONSTRUCTOR_NO_CLEARING (whole)) |
cf72f34d | 2729 | { |
2730 | /* 'whole' is part of the aggregate initializer we're currently | |
2731 | building; if there's no initializer for this member yet, that's an | |
f894a056 | 2732 | error. */ |
f83e6885 | 2733 | if (!ctx->quiet) |
cf72f34d | 2734 | error ("accessing uninitialized member %qD", part); |
2735 | *non_constant_p = true; | |
2736 | return t; | |
2737 | } | |
2738 | ||
09b42213 | 2739 | /* If there's no explicit init for this field, it's value-initialized. */ |
2740 | value = build_value_init (TREE_TYPE (t), tf_warning_or_error); | |
cf72f34d | 2741 | return cxx_eval_constant_expression (ctx, value, |
1227ba74 | 2742 | lval, |
b2a43197 | 2743 | non_constant_p, overflow_p); |
09b42213 | 2744 | } |
2745 | ||
2746 | /* Subroutine of cxx_eval_constant_expression. | |
2747 | Attempt to reduce a field access of a value of class type that is | |
2748 | expressed as a BIT_FIELD_REF. */ | |
2749 | ||
2750 | static tree | |
cf72f34d | 2751 | cxx_eval_bit_field_ref (const constexpr_ctx *ctx, tree t, |
1227ba74 | 2752 | bool lval, |
09b42213 | 2753 | bool *non_constant_p, bool *overflow_p) |
2754 | { | |
2755 | tree orig_whole = TREE_OPERAND (t, 0); | |
2756 | tree retval, fldval, utype, mask; | |
2757 | bool fld_seen = false; | |
2758 | HOST_WIDE_INT istart, isize; | |
cf72f34d | 2759 | tree whole = cxx_eval_constant_expression (ctx, orig_whole, |
1227ba74 | 2760 | lval, |
b2a43197 | 2761 | non_constant_p, overflow_p); |
09b42213 | 2762 | tree start, field, value; |
2763 | unsigned HOST_WIDE_INT i; | |
2764 | ||
2765 | if (whole == orig_whole) | |
2766 | return t; | |
2767 | /* Don't VERIFY_CONSTANT here; we only want to check that we got a | |
2768 | CONSTRUCTOR. */ | |
2769 | if (!*non_constant_p | |
2770 | && TREE_CODE (whole) != VECTOR_CST | |
2771 | && TREE_CODE (whole) != CONSTRUCTOR) | |
2772 | { | |
f83e6885 | 2773 | if (!ctx->quiet) |
09b42213 | 2774 | error ("%qE is not a constant expression", orig_whole); |
2775 | *non_constant_p = true; | |
2776 | } | |
2777 | if (*non_constant_p) | |
2778 | return t; | |
2779 | ||
2780 | if (TREE_CODE (whole) == VECTOR_CST) | |
2781 | return fold_ternary (BIT_FIELD_REF, TREE_TYPE (t), whole, | |
2782 | TREE_OPERAND (t, 1), TREE_OPERAND (t, 2)); | |
2783 | ||
2784 | start = TREE_OPERAND (t, 2); | |
2785 | istart = tree_to_shwi (start); | |
2786 | isize = tree_to_shwi (TREE_OPERAND (t, 1)); | |
2787 | utype = TREE_TYPE (t); | |
2788 | if (!TYPE_UNSIGNED (utype)) | |
2789 | utype = build_nonstandard_integer_type (TYPE_PRECISION (utype), 1); | |
2790 | retval = build_int_cst (utype, 0); | |
2791 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (whole), i, field, value) | |
2792 | { | |
2793 | tree bitpos = bit_position (field); | |
2794 | if (bitpos == start && DECL_SIZE (field) == TREE_OPERAND (t, 1)) | |
2795 | return value; | |
2796 | if (TREE_CODE (TREE_TYPE (field)) == INTEGER_TYPE | |
2797 | && TREE_CODE (value) == INTEGER_CST | |
2798 | && tree_fits_shwi_p (bitpos) | |
2799 | && tree_fits_shwi_p (DECL_SIZE (field))) | |
2800 | { | |
2801 | HOST_WIDE_INT bit = tree_to_shwi (bitpos); | |
2802 | HOST_WIDE_INT sz = tree_to_shwi (DECL_SIZE (field)); | |
2803 | HOST_WIDE_INT shift; | |
2804 | if (bit >= istart && bit + sz <= istart + isize) | |
2805 | { | |
2806 | fldval = fold_convert (utype, value); | |
2807 | mask = build_int_cst_type (utype, -1); | |
2808 | mask = fold_build2 (LSHIFT_EXPR, utype, mask, | |
2809 | size_int (TYPE_PRECISION (utype) - sz)); | |
2810 | mask = fold_build2 (RSHIFT_EXPR, utype, mask, | |
2811 | size_int (TYPE_PRECISION (utype) - sz)); | |
2812 | fldval = fold_build2 (BIT_AND_EXPR, utype, fldval, mask); | |
2813 | shift = bit - istart; | |
2814 | if (BYTES_BIG_ENDIAN) | |
2815 | shift = TYPE_PRECISION (utype) - shift - sz; | |
2816 | fldval = fold_build2 (LSHIFT_EXPR, utype, fldval, | |
2817 | size_int (shift)); | |
2818 | retval = fold_build2 (BIT_IOR_EXPR, utype, retval, fldval); | |
2819 | fld_seen = true; | |
2820 | } | |
2821 | } | |
2822 | } | |
2823 | if (fld_seen) | |
2824 | return fold_convert (TREE_TYPE (t), retval); | |
2825 | gcc_unreachable (); | |
2826 | return error_mark_node; | |
2827 | } | |
2828 | ||
2829 | /* Subroutine of cxx_eval_constant_expression. | |
2830 | Evaluate a short-circuited logical expression T in the context | |
2831 | of a given constexpr CALL. BAILOUT_VALUE is the value for | |
2832 | early return. CONTINUE_VALUE is used here purely for | |
2833 | sanity check purposes. */ | |
2834 | ||
2835 | static tree | |
cf72f34d | 2836 | cxx_eval_logical_expression (const constexpr_ctx *ctx, tree t, |
09b42213 | 2837 | tree bailout_value, tree continue_value, |
1227ba74 | 2838 | bool lval, |
09b42213 | 2839 | bool *non_constant_p, bool *overflow_p) |
2840 | { | |
2841 | tree r; | |
cf72f34d | 2842 | tree lhs = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), |
1227ba74 | 2843 | lval, |
b2a43197 | 2844 | non_constant_p, overflow_p); |
09b42213 | 2845 | VERIFY_CONSTANT (lhs); |
2846 | if (tree_int_cst_equal (lhs, bailout_value)) | |
2847 | return lhs; | |
2848 | gcc_assert (tree_int_cst_equal (lhs, continue_value)); | |
cf72f34d | 2849 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), |
1227ba74 | 2850 | lval, non_constant_p, |
b2a43197 | 2851 | overflow_p); |
09b42213 | 2852 | VERIFY_CONSTANT (r); |
2853 | return r; | |
2854 | } | |
2855 | ||
2856 | /* REF is a COMPONENT_REF designating a particular field. V is a vector of | |
2857 | CONSTRUCTOR elements to initialize (part of) an object containing that | |
2858 | field. Return a pointer to the constructor_elt corresponding to the | |
2859 | initialization of the field. */ | |
2860 | ||
2861 | static constructor_elt * | |
2862 | base_field_constructor_elt (vec<constructor_elt, va_gc> *v, tree ref) | |
2863 | { | |
2864 | tree aggr = TREE_OPERAND (ref, 0); | |
2865 | tree field = TREE_OPERAND (ref, 1); | |
2866 | HOST_WIDE_INT i; | |
2867 | constructor_elt *ce; | |
2868 | ||
2869 | gcc_assert (TREE_CODE (ref) == COMPONENT_REF); | |
2870 | ||
2871 | if (TREE_CODE (aggr) == COMPONENT_REF) | |
2872 | { | |
2873 | constructor_elt *base_ce | |
2874 | = base_field_constructor_elt (v, aggr); | |
2875 | v = CONSTRUCTOR_ELTS (base_ce->value); | |
2876 | } | |
2877 | ||
2878 | for (i = 0; vec_safe_iterate (v, i, &ce); ++i) | |
2879 | if (ce->index == field) | |
2880 | return ce; | |
2881 | ||
2882 | gcc_unreachable (); | |
2883 | return NULL; | |
2884 | } | |
2885 | ||
cf72f34d | 2886 | /* Some of the expressions fed to the constexpr mechanism are calls to |
2887 | constructors, which have type void. In that case, return the type being | |
2888 | initialized by the constructor. */ | |
2889 | ||
2890 | static tree | |
2891 | initialized_type (tree t) | |
2892 | { | |
2893 | if (TYPE_P (t)) | |
2894 | return t; | |
59183fff | 2895 | tree type = TREE_TYPE (t); |
48c03f15 | 2896 | if (TREE_CODE (t) == CALL_EXPR) |
cf72f34d | 2897 | { |
2898 | /* A constructor call has void type, so we need to look deeper. */ | |
2899 | tree fn = get_function_named_in_call (t); | |
2900 | if (fn && TREE_CODE (fn) == FUNCTION_DECL | |
2901 | && DECL_CXX_CONSTRUCTOR_P (fn)) | |
2902 | type = DECL_CONTEXT (fn); | |
2903 | } | |
48c03f15 | 2904 | else if (TREE_CODE (t) == COMPOUND_EXPR) |
2905 | return initialized_type (TREE_OPERAND (t, 1)); | |
59183fff | 2906 | else if (TREE_CODE (t) == AGGR_INIT_EXPR) |
2907 | type = TREE_TYPE (AGGR_INIT_EXPR_SLOT (t)); | |
2908 | return cv_unqualified (type); | |
cf72f34d | 2909 | } |
2910 | ||
2911 | /* We're about to initialize element INDEX of an array or class from VALUE. | |
2912 | Set up NEW_CTX appropriately by adjusting .object to refer to the | |
2913 | subobject and creating a new CONSTRUCTOR if the element is itself | |
2914 | a class or array. */ | |
2915 | ||
2916 | static void | |
2917 | init_subob_ctx (const constexpr_ctx *ctx, constexpr_ctx &new_ctx, | |
2918 | tree index, tree &value) | |
2919 | { | |
2920 | new_ctx = *ctx; | |
2921 | ||
2922 | if (index && TREE_CODE (index) != INTEGER_CST | |
2923 | && TREE_CODE (index) != FIELD_DECL) | |
2924 | /* This won't have an element in the new CONSTRUCTOR. */ | |
2925 | return; | |
2926 | ||
2927 | tree type = initialized_type (value); | |
2928 | if (!AGGREGATE_TYPE_P (type) && !VECTOR_TYPE_P (type)) | |
2929 | /* A non-aggregate member doesn't get its own CONSTRUCTOR. */ | |
2930 | return; | |
2931 | ||
2932 | /* The sub-aggregate initializer might contain a placeholder; | |
2933 | update object to refer to the subobject and ctor to refer to | |
2934 | the (newly created) sub-initializer. */ | |
2935 | if (ctx->object) | |
2936 | new_ctx.object = build_ctor_subob_ref (index, type, ctx->object); | |
2937 | tree elt = build_constructor (type, NULL); | |
165d0d5b | 2938 | CONSTRUCTOR_NO_CLEARING (elt) = true; |
cf72f34d | 2939 | new_ctx.ctor = elt; |
2940 | ||
2941 | if (TREE_CODE (value) == TARGET_EXPR) | |
2942 | /* Avoid creating another CONSTRUCTOR when we expand the TARGET_EXPR. */ | |
2943 | value = TARGET_EXPR_INITIAL (value); | |
2944 | } | |
2945 | ||
2946 | /* We're about to process an initializer for a class or array TYPE. Make | |
2947 | sure that CTX is set up appropriately. */ | |
2948 | ||
2949 | static void | |
2950 | verify_ctor_sanity (const constexpr_ctx *ctx, tree type) | |
2951 | { | |
2952 | /* We don't bother building a ctor for an empty base subobject. */ | |
2953 | if (is_empty_class (type)) | |
2954 | return; | |
2955 | ||
2956 | /* We're in the middle of an initializer that might involve placeholders; | |
2957 | our caller should have created a CONSTRUCTOR for us to put the | |
2958 | initializer into. We will either return that constructor or T. */ | |
2959 | gcc_assert (ctx->ctor); | |
2960 | gcc_assert (same_type_ignoring_top_level_qualifiers_p | |
2961 | (type, TREE_TYPE (ctx->ctor))); | |
bbf58224 | 2962 | /* We used to check that ctx->ctor was empty, but that isn't the case when |
2963 | the object is zero-initialized before calling the constructor. */ | |
cf72f34d | 2964 | if (ctx->object) |
d9751a3c | 2965 | { |
2966 | tree otype = TREE_TYPE (ctx->object); | |
2967 | gcc_assert (same_type_ignoring_top_level_qualifiers_p (type, otype) | |
2968 | /* Handle flexible array members. */ | |
2969 | || (TREE_CODE (otype) == ARRAY_TYPE | |
2970 | && TYPE_DOMAIN (otype) == NULL_TREE | |
2971 | && TREE_CODE (type) == ARRAY_TYPE | |
2972 | && (same_type_ignoring_top_level_qualifiers_p | |
2973 | (TREE_TYPE (type), TREE_TYPE (otype))))); | |
2974 | } | |
cf72f34d | 2975 | gcc_assert (!ctx->object || !DECL_P (ctx->object) |
2976 | || *(ctx->values->get (ctx->object)) == ctx->ctor); | |
2977 | } | |
2978 | ||
09b42213 | 2979 | /* Subroutine of cxx_eval_constant_expression. |
2980 | The expression tree T denotes a C-style array or a C-style | |
2981 | aggregate. Reduce it to a constant expression. */ | |
2982 | ||
2983 | static tree | |
cf72f34d | 2984 | cxx_eval_bare_aggregate (const constexpr_ctx *ctx, tree t, |
1227ba74 | 2985 | bool lval, |
09b42213 | 2986 | bool *non_constant_p, bool *overflow_p) |
2987 | { | |
2988 | vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (t); | |
09b42213 | 2989 | bool changed = false; |
2990 | gcc_assert (!BRACE_ENCLOSED_INITIALIZER_P (t)); | |
68464393 | 2991 | tree type = TREE_TYPE (t); |
cf72f34d | 2992 | |
68464393 | 2993 | constexpr_ctx new_ctx; |
d2dd85e3 | 2994 | if (TYPE_PTRMEMFUNC_P (type) || VECTOR_TYPE_P (type)) |
68464393 | 2995 | { |
d2dd85e3 | 2996 | /* We don't really need the ctx->ctor business for a PMF or |
2997 | vector, but it's simpler to use the same code. */ | |
68464393 | 2998 | new_ctx = *ctx; |
2999 | new_ctx.ctor = build_constructor (type, NULL); | |
3000 | new_ctx.object = NULL_TREE; | |
3001 | ctx = &new_ctx; | |
3002 | }; | |
3003 | verify_ctor_sanity (ctx, type); | |
cf72f34d | 3004 | vec<constructor_elt, va_gc> **p = &CONSTRUCTOR_ELTS (ctx->ctor); |
3005 | vec_alloc (*p, vec_safe_length (v)); | |
3006 | ||
58b0f9ce | 3007 | unsigned i; |
3008 | tree index, value; | |
3009 | bool constant_p = true; | |
3010 | bool side_effects_p = false; | |
cf72f34d | 3011 | FOR_EACH_CONSTRUCTOR_ELT (v, i, index, value) |
09b42213 | 3012 | { |
5ae773e4 | 3013 | tree orig_value = value; |
cf72f34d | 3014 | init_subob_ctx (ctx, new_ctx, index, value); |
3015 | if (new_ctx.ctor != ctx->ctor) | |
3016 | /* If we built a new CONSTRUCTOR, attach it now so that other | |
3017 | initializers can refer to it. */ | |
3018 | CONSTRUCTOR_APPEND_ELT (*p, index, new_ctx.ctor); | |
3019 | tree elt = cxx_eval_constant_expression (&new_ctx, value, | |
1227ba74 | 3020 | lval, |
b2a43197 | 3021 | non_constant_p, overflow_p); |
09b42213 | 3022 | /* Don't VERIFY_CONSTANT here. */ |
f83e6885 | 3023 | if (ctx->quiet && *non_constant_p) |
cf72f34d | 3024 | break; |
5ae773e4 | 3025 | if (elt != orig_value) |
09b42213 | 3026 | changed = true; |
58b0f9ce | 3027 | |
3028 | if (!TREE_CONSTANT (elt)) | |
3029 | constant_p = false; | |
3030 | if (TREE_SIDE_EFFECTS (elt)) | |
3031 | side_effects_p = true; | |
cf72f34d | 3032 | if (index && TREE_CODE (index) == COMPONENT_REF) |
09b42213 | 3033 | { |
3034 | /* This is an initialization of a vfield inside a base | |
3035 | subaggregate that we already initialized; push this | |
3036 | initialization into the previous initialization. */ | |
cf72f34d | 3037 | constructor_elt *inner = base_field_constructor_elt (*p, index); |
09b42213 | 3038 | inner->value = elt; |
cf72f34d | 3039 | changed = true; |
09b42213 | 3040 | } |
cf72f34d | 3041 | else if (index |
3042 | && (TREE_CODE (index) == NOP_EXPR | |
3043 | || TREE_CODE (index) == POINTER_PLUS_EXPR)) | |
09b42213 | 3044 | { |
3045 | /* This is an initializer for an empty base; now that we've | |
3046 | checked that it's constant, we can ignore it. */ | |
cf72f34d | 3047 | gcc_assert (is_empty_class (TREE_TYPE (TREE_TYPE (index)))); |
3048 | changed = true; | |
3049 | } | |
09b42213 | 3050 | else |
79e65a6b | 3051 | { |
0dd49b5a | 3052 | if (new_ctx.ctor != ctx->ctor) |
3053 | { | |
3054 | /* We appended this element above; update the value. */ | |
3055 | gcc_assert ((*p)->last().index == index); | |
3056 | (*p)->last().value = elt; | |
3057 | } | |
3058 | else | |
3059 | CONSTRUCTOR_APPEND_ELT (*p, index, elt); | |
3060 | /* Adding or replacing an element might change the ctor's flags. */ | |
79e65a6b | 3061 | TREE_CONSTANT (ctx->ctor) = constant_p; |
3062 | TREE_SIDE_EFFECTS (ctx->ctor) = side_effects_p; | |
3063 | } | |
09b42213 | 3064 | } |
3065 | if (*non_constant_p || !changed) | |
cf72f34d | 3066 | return t; |
3067 | t = ctx->ctor; | |
3068 | /* We're done building this CONSTRUCTOR, so now we can interpret an | |
3069 | element without an explicit initializer as value-initialized. */ | |
165d0d5b | 3070 | CONSTRUCTOR_NO_CLEARING (t) = false; |
58b0f9ce | 3071 | TREE_CONSTANT (t) = constant_p; |
3072 | TREE_SIDE_EFFECTS (t) = side_effects_p; | |
68464393 | 3073 | if (VECTOR_TYPE_P (type)) |
09b42213 | 3074 | t = fold (t); |
3075 | return t; | |
3076 | } | |
3077 | ||
3078 | /* Subroutine of cxx_eval_constant_expression. | |
3079 | The expression tree T is a VEC_INIT_EXPR which denotes the desired | |
3080 | initialization of a non-static data member of array type. Reduce it to a | |
3081 | CONSTRUCTOR. | |
3082 | ||
3083 | Note that apart from value-initialization (when VALUE_INIT is true), | |
3084 | this is only intended to support value-initialization and the | |
3085 | initializations done by defaulted constructors for classes with | |
3086 | non-static data members of array type. In this case, VEC_INIT_EXPR_INIT | |
3087 | will either be NULL_TREE for the default constructor, or a COMPONENT_REF | |
3088 | for the copy/move constructor. */ | |
3089 | ||
3090 | static tree | |
cf72f34d | 3091 | cxx_eval_vec_init_1 (const constexpr_ctx *ctx, tree atype, tree init, |
1227ba74 | 3092 | bool value_init, bool lval, |
09b42213 | 3093 | bool *non_constant_p, bool *overflow_p) |
3094 | { | |
3095 | tree elttype = TREE_TYPE (atype); | |
cf72f34d | 3096 | verify_ctor_sanity (ctx, atype); |
3097 | vec<constructor_elt, va_gc> **p = &CONSTRUCTOR_ELTS (ctx->ctor); | |
09b42213 | 3098 | bool pre_init = false; |
3e520b97 | 3099 | unsigned HOST_WIDE_INT i; |
c4970310 | 3100 | tsubst_flags_t complain = ctx->quiet ? tf_none : tf_warning_or_error; |
09b42213 | 3101 | |
3102 | /* For the default constructor, build up a call to the default | |
3103 | constructor of the element type. We only need to handle class types | |
3104 | here, as for a constructor to be constexpr, all members must be | |
3105 | initialized, which for a defaulted default constructor means they must | |
3106 | be of a class type with a constexpr default constructor. */ | |
3107 | if (TREE_CODE (elttype) == ARRAY_TYPE) | |
3108 | /* We only do this at the lowest level. */; | |
3109 | else if (value_init) | |
3110 | { | |
c4970310 | 3111 | init = build_value_init (elttype, complain); |
09b42213 | 3112 | pre_init = true; |
3113 | } | |
3114 | else if (!init) | |
3115 | { | |
3116 | vec<tree, va_gc> *argvec = make_tree_vector (); | |
3117 | init = build_special_member_call (NULL_TREE, complete_ctor_identifier, | |
3118 | &argvec, elttype, LOOKUP_NORMAL, | |
c4970310 | 3119 | complain); |
09b42213 | 3120 | release_tree_vector (argvec); |
59183fff | 3121 | init = build_aggr_init_expr (elttype, init); |
09b42213 | 3122 | pre_init = true; |
3123 | } | |
3124 | ||
51f0c7e2 | 3125 | tree nelts = get_array_or_vector_nelts (ctx, atype, non_constant_p, |
3126 | overflow_p); | |
3127 | unsigned HOST_WIDE_INT max = tree_to_uhwi (nelts); | |
3e520b97 | 3128 | for (i = 0; i < max; ++i) |
09b42213 | 3129 | { |
3130 | tree idx = build_int_cst (size_type_node, i); | |
3131 | tree eltinit; | |
d9377ad5 | 3132 | bool reuse = false; |
cf72f34d | 3133 | constexpr_ctx new_ctx; |
3134 | init_subob_ctx (ctx, new_ctx, idx, pre_init ? init : elttype); | |
3135 | if (new_ctx.ctor != ctx->ctor) | |
3136 | CONSTRUCTOR_APPEND_ELT (*p, idx, new_ctx.ctor); | |
09b42213 | 3137 | if (TREE_CODE (elttype) == ARRAY_TYPE) |
3138 | { | |
3139 | /* A multidimensional array; recurse. */ | |
3140 | if (value_init || init == NULL_TREE) | |
d9377ad5 | 3141 | { |
3142 | eltinit = NULL_TREE; | |
3143 | reuse = i == 0; | |
3144 | } | |
09b42213 | 3145 | else |
c4970310 | 3146 | eltinit = cp_build_array_ref (input_location, init, idx, complain); |
cf72f34d | 3147 | eltinit = cxx_eval_vec_init_1 (&new_ctx, elttype, eltinit, value_init, |
1227ba74 | 3148 | lval, |
09b42213 | 3149 | non_constant_p, overflow_p); |
3150 | } | |
3151 | else if (pre_init) | |
3152 | { | |
3153 | /* Initializing an element using value or default initialization | |
3154 | we just pre-built above. */ | |
0e9064d2 | 3155 | if (init == void_node) |
3156 | /* Trivial default-init, don't do anything to the CONSTRUCTOR. */ | |
3157 | return ctx->ctor; | |
d9377ad5 | 3158 | eltinit = cxx_eval_constant_expression (&new_ctx, init, lval, |
3159 | non_constant_p, overflow_p); | |
3160 | reuse = i == 0; | |
09b42213 | 3161 | } |
3162 | else | |
3163 | { | |
3164 | /* Copying an element. */ | |
3165 | gcc_assert (same_type_ignoring_top_level_qualifiers_p | |
3166 | (atype, TREE_TYPE (init))); | |
c4970310 | 3167 | eltinit = cp_build_array_ref (input_location, init, idx, complain); |
18bede74 | 3168 | if (!lvalue_p (init)) |
09b42213 | 3169 | eltinit = move (eltinit); |
c4970310 | 3170 | eltinit = force_rvalue (eltinit, complain); |
eb7c25cc | 3171 | eltinit = cxx_eval_constant_expression (&new_ctx, eltinit, lval, |
3172 | non_constant_p, overflow_p); | |
09b42213 | 3173 | } |
f83e6885 | 3174 | if (*non_constant_p && !ctx->quiet) |
cf72f34d | 3175 | break; |
3176 | if (new_ctx.ctor != ctx->ctor) | |
3177 | { | |
3178 | /* We appended this element above; update the value. */ | |
3179 | gcc_assert ((*p)->last().index == idx); | |
3180 | (*p)->last().value = eltinit; | |
3181 | } | |
3182 | else | |
3183 | CONSTRUCTOR_APPEND_ELT (*p, idx, eltinit); | |
d9377ad5 | 3184 | /* Reuse the result of cxx_eval_constant_expression call |
eb7c25cc | 3185 | from the first iteration to all others if it is a constant |
3186 | initializer that doesn't require relocations. */ | |
d9377ad5 | 3187 | if (reuse |
3188 | && max > 1 | |
eb7c25cc | 3189 | && (eltinit == NULL_TREE |
3190 | || (initializer_constant_valid_p (eltinit, TREE_TYPE (eltinit)) | |
3191 | == null_pointer_node))) | |
d9377ad5 | 3192 | { |
3193 | if (new_ctx.ctor != ctx->ctor) | |
3194 | eltinit = new_ctx.ctor; | |
228a2cd8 | 3195 | tree range = build2 (RANGE_EXPR, size_type_node, |
3196 | build_int_cst (size_type_node, 1), | |
3197 | build_int_cst (size_type_node, max - 1)); | |
3198 | CONSTRUCTOR_APPEND_ELT (*p, range, unshare_constructor (eltinit)); | |
d9377ad5 | 3199 | break; |
3200 | } | |
228a2cd8 | 3201 | else if (i == 0) |
3202 | vec_safe_reserve (*p, max); | |
09b42213 | 3203 | } |
3204 | ||
3205 | if (!*non_constant_p) | |
3206 | { | |
cf72f34d | 3207 | init = ctx->ctor; |
165d0d5b | 3208 | CONSTRUCTOR_NO_CLEARING (init) = false; |
09b42213 | 3209 | } |
09b42213 | 3210 | return init; |
3211 | } | |
3212 | ||
3213 | static tree | |
cf72f34d | 3214 | cxx_eval_vec_init (const constexpr_ctx *ctx, tree t, |
1227ba74 | 3215 | bool lval, |
09b42213 | 3216 | bool *non_constant_p, bool *overflow_p) |
3217 | { | |
3218 | tree atype = TREE_TYPE (t); | |
3219 | tree init = VEC_INIT_EXPR_INIT (t); | |
cf72f34d | 3220 | tree r = cxx_eval_vec_init_1 (ctx, atype, init, |
09b42213 | 3221 | VEC_INIT_EXPR_VALUE_INIT (t), |
1227ba74 | 3222 | lval, non_constant_p, overflow_p); |
09b42213 | 3223 | if (*non_constant_p) |
3224 | return t; | |
3225 | else | |
3226 | return r; | |
3227 | } | |
3228 | ||
6b53d686 | 3229 | /* Like same_type_ignoring_top_level_qualifiers_p, but also handle the case |
3230 | where the desired type is an array of unknown bounds because the variable | |
3231 | has had its bounds deduced since the wrapping expression was created. */ | |
3232 | ||
3233 | static bool | |
3234 | same_type_ignoring_tlq_and_bounds_p (tree type1, tree type2) | |
3235 | { | |
3236 | while (TREE_CODE (type1) == ARRAY_TYPE | |
3237 | && TREE_CODE (type2) == ARRAY_TYPE | |
3238 | && (!TYPE_DOMAIN (type1) || !TYPE_DOMAIN (type2))) | |
3239 | { | |
3240 | type1 = TREE_TYPE (type1); | |
3241 | type2 = TREE_TYPE (type2); | |
3242 | } | |
3243 | return same_type_ignoring_top_level_qualifiers_p (type1, type2); | |
3244 | } | |
3245 | ||
09b42213 | 3246 | /* A less strict version of fold_indirect_ref_1, which requires cv-quals to |
3247 | match. We want to be less strict for simple *& folding; if we have a | |
3248 | non-const temporary that we access through a const pointer, that should | |
3249 | work. We handle this here rather than change fold_indirect_ref_1 | |
3250 | because we're dealing with things like ADDR_EXPR of INTEGER_CST which | |
3251 | don't really make sense outside of constant expression evaluation. Also | |
3252 | we want to allow folding to COMPONENT_REF, which could cause trouble | |
3253 | with TBAA in fold_indirect_ref_1. | |
3254 | ||
3255 | Try to keep this function synced with fold_indirect_ref_1. */ | |
3256 | ||
3257 | static tree | |
3258 | cxx_fold_indirect_ref (location_t loc, tree type, tree op0, bool *empty_base) | |
3259 | { | |
7d8e655d | 3260 | tree sub = op0; |
3261 | tree subtype; | |
3262 | poly_uint64 const_op01; | |
09b42213 | 3263 | |
09b42213 | 3264 | STRIP_NOPS (sub); |
3265 | subtype = TREE_TYPE (sub); | |
d03fa520 | 3266 | if (!INDIRECT_TYPE_P (subtype)) |
09b42213 | 3267 | return NULL_TREE; |
3268 | ||
3269 | if (TREE_CODE (sub) == ADDR_EXPR) | |
3270 | { | |
3271 | tree op = TREE_OPERAND (sub, 0); | |
3272 | tree optype = TREE_TYPE (op); | |
3273 | ||
3274 | /* *&CONST_DECL -> to the value of the const decl. */ | |
3275 | if (TREE_CODE (op) == CONST_DECL) | |
3276 | return DECL_INITIAL (op); | |
3277 | /* *&p => p; make sure to handle *&"str"[cst] here. */ | |
6b53d686 | 3278 | if (same_type_ignoring_tlq_and_bounds_p (optype, type)) |
09b42213 | 3279 | { |
3280 | tree fop = fold_read_from_constant_string (op); | |
3281 | if (fop) | |
3282 | return fop; | |
3283 | else | |
3284 | return op; | |
3285 | } | |
3286 | /* *(foo *)&fooarray => fooarray[0] */ | |
3287 | else if (TREE_CODE (optype) == ARRAY_TYPE | |
3288 | && (same_type_ignoring_top_level_qualifiers_p | |
3289 | (type, TREE_TYPE (optype)))) | |
3290 | { | |
3291 | tree type_domain = TYPE_DOMAIN (optype); | |
3292 | tree min_val = size_zero_node; | |
3293 | if (type_domain && TYPE_MIN_VALUE (type_domain)) | |
3294 | min_val = TYPE_MIN_VALUE (type_domain); | |
3295 | return build4_loc (loc, ARRAY_REF, type, op, min_val, | |
3296 | NULL_TREE, NULL_TREE); | |
3297 | } | |
3298 | /* *(foo *)&complexfoo => __real__ complexfoo */ | |
3299 | else if (TREE_CODE (optype) == COMPLEX_TYPE | |
3300 | && (same_type_ignoring_top_level_qualifiers_p | |
3301 | (type, TREE_TYPE (optype)))) | |
3302 | return fold_build1_loc (loc, REALPART_EXPR, type, op); | |
3303 | /* *(foo *)&vectorfoo => BIT_FIELD_REF<vectorfoo,...> */ | |
76249021 | 3304 | else if (VECTOR_TYPE_P (optype) |
09b42213 | 3305 | && (same_type_ignoring_top_level_qualifiers_p |
3306 | (type, TREE_TYPE (optype)))) | |
3307 | { | |
3308 | tree part_width = TYPE_SIZE (type); | |
3309 | tree index = bitsize_int (0); | |
7d8e655d | 3310 | return fold_build3_loc (loc, BIT_FIELD_REF, type, op, part_width, |
3311 | index); | |
09b42213 | 3312 | } |
3313 | /* Also handle conversion to an empty base class, which | |
3314 | is represented with a NOP_EXPR. */ | |
3315 | else if (is_empty_class (type) | |
3316 | && CLASS_TYPE_P (optype) | |
3317 | && DERIVED_FROM_P (type, optype)) | |
3318 | { | |
3319 | *empty_base = true; | |
3320 | return op; | |
3321 | } | |
3322 | /* *(foo *)&struct_with_foo_field => COMPONENT_REF */ | |
3323 | else if (RECORD_OR_UNION_TYPE_P (optype)) | |
3324 | { | |
3325 | tree field = TYPE_FIELDS (optype); | |
3326 | for (; field; field = DECL_CHAIN (field)) | |
3327 | if (TREE_CODE (field) == FIELD_DECL | |
a48667ee | 3328 | && TREE_TYPE (field) != error_mark_node |
09b42213 | 3329 | && integer_zerop (byte_position (field)) |
3330 | && (same_type_ignoring_top_level_qualifiers_p | |
3331 | (TREE_TYPE (field), type))) | |
a48667ee | 3332 | return fold_build3 (COMPONENT_REF, type, op, field, NULL_TREE); |
09b42213 | 3333 | } |
3334 | } | |
3335 | else if (TREE_CODE (sub) == POINTER_PLUS_EXPR | |
7d8e655d | 3336 | && poly_int_tree_p (TREE_OPERAND (sub, 1), &const_op01)) |
09b42213 | 3337 | { |
3338 | tree op00 = TREE_OPERAND (sub, 0); | |
3339 | tree op01 = TREE_OPERAND (sub, 1); | |
3340 | ||
3341 | STRIP_NOPS (op00); | |
3342 | if (TREE_CODE (op00) == ADDR_EXPR) | |
3343 | { | |
3344 | tree op00type; | |
3345 | op00 = TREE_OPERAND (op00, 0); | |
3346 | op00type = TREE_TYPE (op00); | |
3347 | ||
3348 | /* ((foo*)&vectorfoo)[1] => BIT_FIELD_REF<vectorfoo,...> */ | |
76249021 | 3349 | if (VECTOR_TYPE_P (op00type) |
7d8e655d | 3350 | && same_type_ignoring_top_level_qualifiers_p |
3351 | (type, TREE_TYPE (op00type)) | |
3352 | /* POINTER_PLUS_EXPR second operand is sizetype, unsigned, | |
3353 | but we want to treat offsets with MSB set as negative. | |
3354 | For the code below negative offsets are invalid and | |
3355 | TYPE_SIZE of the element is something unsigned, so | |
3356 | check whether op01 fits into poly_int64, which implies | |
3357 | it is from 0 to INTTYPE_MAXIMUM (HOST_WIDE_INT), and | |
3358 | then just use poly_uint64 because we want to treat the | |
3359 | value as unsigned. */ | |
3360 | && tree_fits_poly_int64_p (op01)) | |
09b42213 | 3361 | { |
09b42213 | 3362 | tree part_width = TYPE_SIZE (type); |
7d8e655d | 3363 | poly_uint64 max_offset |
3364 | = (tree_to_uhwi (part_width) / BITS_PER_UNIT | |
3365 | * TYPE_VECTOR_SUBPARTS (op00type)); | |
3366 | if (known_lt (const_op01, max_offset)) | |
3367 | { | |
3368 | tree index = bitsize_int (const_op01 * BITS_PER_UNIT); | |
3369 | return fold_build3_loc (loc, | |
3370 | BIT_FIELD_REF, type, op00, | |
3371 | part_width, index); | |
3372 | } | |
09b42213 | 3373 | } |
3374 | /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */ | |
3375 | else if (TREE_CODE (op00type) == COMPLEX_TYPE | |
3376 | && (same_type_ignoring_top_level_qualifiers_p | |
3377 | (type, TREE_TYPE (op00type)))) | |
3378 | { | |
7d8e655d | 3379 | if (known_eq (wi::to_poly_offset (TYPE_SIZE_UNIT (type)), |
3380 | const_op01)) | |
09b42213 | 3381 | return fold_build1_loc (loc, IMAGPART_EXPR, type, op00); |
3382 | } | |
3383 | /* ((foo *)&fooarray)[1] => fooarray[1] */ | |
3384 | else if (TREE_CODE (op00type) == ARRAY_TYPE | |
3385 | && (same_type_ignoring_top_level_qualifiers_p | |
3386 | (type, TREE_TYPE (op00type)))) | |
3387 | { | |
3388 | tree type_domain = TYPE_DOMAIN (op00type); | |
3389 | tree min_val = size_zero_node; | |
3390 | if (type_domain && TYPE_MIN_VALUE (type_domain)) | |
3391 | min_val = TYPE_MIN_VALUE (type_domain); | |
53fa96c0 | 3392 | offset_int off = wi::to_offset (op01); |
3393 | offset_int el_sz = wi::to_offset (TYPE_SIZE_UNIT (type)); | |
3394 | offset_int remainder; | |
3395 | off = wi::divmod_trunc (off, el_sz, SIGNED, &remainder); | |
3396 | if (remainder == 0 && TREE_CODE (min_val) == INTEGER_CST) | |
3397 | { | |
3398 | off = off + wi::to_offset (min_val); | |
3399 | op01 = wide_int_to_tree (sizetype, off); | |
3400 | return build4_loc (loc, ARRAY_REF, type, op00, op01, | |
3401 | NULL_TREE, NULL_TREE); | |
3402 | } | |
09b42213 | 3403 | } |
3404 | /* Also handle conversion to an empty base class, which | |
3405 | is represented with a NOP_EXPR. */ | |
3406 | else if (is_empty_class (type) | |
3407 | && CLASS_TYPE_P (op00type) | |
3408 | && DERIVED_FROM_P (type, op00type)) | |
3409 | { | |
3410 | *empty_base = true; | |
3411 | return op00; | |
3412 | } | |
3413 | /* ((foo *)&struct_with_foo_field)[1] => COMPONENT_REF */ | |
3414 | else if (RECORD_OR_UNION_TYPE_P (op00type)) | |
3415 | { | |
3416 | tree field = TYPE_FIELDS (op00type); | |
3417 | for (; field; field = DECL_CHAIN (field)) | |
3418 | if (TREE_CODE (field) == FIELD_DECL | |
a48667ee | 3419 | && TREE_TYPE (field) != error_mark_node |
09b42213 | 3420 | && tree_int_cst_equal (byte_position (field), op01) |
3421 | && (same_type_ignoring_top_level_qualifiers_p | |
3422 | (TREE_TYPE (field), type))) | |
a48667ee | 3423 | return fold_build3 (COMPONENT_REF, type, op00, |
3424 | field, NULL_TREE); | |
09b42213 | 3425 | } |
3426 | } | |
3427 | } | |
3428 | /* *(foo *)fooarrptr => (*fooarrptr)[0] */ | |
3429 | else if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE | |
3430 | && (same_type_ignoring_top_level_qualifiers_p | |
3431 | (type, TREE_TYPE (TREE_TYPE (subtype))))) | |
3432 | { | |
3433 | tree type_domain; | |
3434 | tree min_val = size_zero_node; | |
7d8e655d | 3435 | tree newsub |
3436 | = cxx_fold_indirect_ref (loc, TREE_TYPE (subtype), sub, NULL); | |
09b42213 | 3437 | if (newsub) |
3438 | sub = newsub; | |
3439 | else | |
3440 | sub = build1_loc (loc, INDIRECT_REF, TREE_TYPE (subtype), sub); | |
3441 | type_domain = TYPE_DOMAIN (TREE_TYPE (sub)); | |
3442 | if (type_domain && TYPE_MIN_VALUE (type_domain)) | |
3443 | min_val = TYPE_MIN_VALUE (type_domain); | |
3444 | return build4_loc (loc, ARRAY_REF, type, sub, min_val, NULL_TREE, | |
3445 | NULL_TREE); | |
3446 | } | |
3447 | ||
3448 | return NULL_TREE; | |
3449 | } | |
3450 | ||
3451 | static tree | |
cf72f34d | 3452 | cxx_eval_indirect_ref (const constexpr_ctx *ctx, tree t, |
1227ba74 | 3453 | bool lval, |
09b42213 | 3454 | bool *non_constant_p, bool *overflow_p) |
3455 | { | |
3456 | tree orig_op0 = TREE_OPERAND (t, 0); | |
09b42213 | 3457 | bool empty_base = false; |
09b42213 | 3458 | |
d2c63826 | 3459 | /* We can handle a MEM_REF like an INDIRECT_REF, if MEM_REF's second |
3460 | operand is an integer-zero. Otherwise reject the MEM_REF for now. */ | |
3461 | ||
3462 | if (TREE_CODE (t) == MEM_REF | |
3463 | && (!TREE_OPERAND (t, 1) || !integer_zerop (TREE_OPERAND (t, 1)))) | |
3464 | { | |
3465 | gcc_assert (ctx->quiet); | |
3466 | *non_constant_p = true; | |
3467 | return t; | |
3468 | } | |
3469 | ||
7e0f3388 | 3470 | /* First try to simplify it directly. */ |
3471 | tree r = cxx_fold_indirect_ref (EXPR_LOCATION (t), TREE_TYPE (t), orig_op0, | |
3472 | &empty_base); | |
3473 | if (!r) | |
09b42213 | 3474 | { |
7e0f3388 | 3475 | /* If that didn't work, evaluate the operand first. */ |
3476 | tree op0 = cxx_eval_constant_expression (ctx, orig_op0, | |
3477 | /*lval*/false, non_constant_p, | |
3478 | overflow_p); | |
3479 | /* Don't VERIFY_CONSTANT here. */ | |
3480 | if (*non_constant_p) | |
3481 | return t; | |
3482 | ||
cb768824 | 3483 | if (!lval && integer_zerop (op0)) |
3484 | { | |
3485 | if (!ctx->quiet) | |
3486 | error ("dereferencing a null pointer"); | |
3487 | *non_constant_p = true; | |
3488 | return t; | |
3489 | } | |
3490 | ||
7e0f3388 | 3491 | r = cxx_fold_indirect_ref (EXPR_LOCATION (t), TREE_TYPE (t), op0, |
3492 | &empty_base); | |
3493 | if (r == NULL_TREE) | |
09b42213 | 3494 | { |
3495 | /* We couldn't fold to a constant value. Make sure it's not | |
3496 | something we should have been able to fold. */ | |
7e0f3388 | 3497 | tree sub = op0; |
3498 | STRIP_NOPS (sub); | |
3499 | if (TREE_CODE (sub) == ADDR_EXPR) | |
3500 | { | |
3501 | gcc_assert (!same_type_ignoring_top_level_qualifiers_p | |
3502 | (TREE_TYPE (TREE_TYPE (sub)), TREE_TYPE (t))); | |
3503 | /* DR 1188 says we don't have to deal with this. */ | |
3504 | if (!ctx->quiet) | |
3505 | error ("accessing value of %qE through a %qT glvalue in a " | |
3506 | "constant expression", build_fold_indirect_ref (sub), | |
3507 | TREE_TYPE (t)); | |
3508 | *non_constant_p = true; | |
3509 | return t; | |
3510 | } | |
3511 | ||
3512 | if (lval && op0 != orig_op0) | |
3513 | return build1 (INDIRECT_REF, TREE_TYPE (t), op0); | |
3514 | if (!lval) | |
3515 | VERIFY_CONSTANT (t); | |
09b42213 | 3516 | return t; |
3517 | } | |
3518 | } | |
3519 | ||
7e0f3388 | 3520 | r = cxx_eval_constant_expression (ctx, r, |
3521 | lval, non_constant_p, overflow_p); | |
3522 | if (*non_constant_p) | |
3523 | return t; | |
3524 | ||
ce4ffd9e | 3525 | /* If we're pulling out the value of an empty base, just return an empty |
09b42213 | 3526 | CONSTRUCTOR. */ |
1227ba74 | 3527 | if (empty_base && !lval) |
09b42213 | 3528 | { |
09b42213 | 3529 | r = build_constructor (TREE_TYPE (t), NULL); |
3530 | TREE_CONSTANT (r) = true; | |
3531 | } | |
3532 | ||
09b42213 | 3533 | return r; |
3534 | } | |
3535 | ||
3536 | /* Complain about R, a VAR_DECL, not being usable in a constant expression. | |
3537 | Shared between potential_constant_expression and | |
3538 | cxx_eval_constant_expression. */ | |
3539 | ||
3540 | static void | |
3541 | non_const_var_error (tree r) | |
3542 | { | |
3543 | tree type = TREE_TYPE (r); | |
3544 | error ("the value of %qD is not usable in a constant " | |
3545 | "expression", r); | |
3546 | /* Avoid error cascade. */ | |
3547 | if (DECL_INITIAL (r) == error_mark_node) | |
3548 | return; | |
3549 | if (DECL_DECLARED_CONSTEXPR_P (r)) | |
3550 | inform (DECL_SOURCE_LOCATION (r), | |
3551 | "%qD used in its own initializer", r); | |
3552 | else if (INTEGRAL_OR_ENUMERATION_TYPE_P (type)) | |
3553 | { | |
3554 | if (!CP_TYPE_CONST_P (type)) | |
3555 | inform (DECL_SOURCE_LOCATION (r), | |
3556 | "%q#D is not const", r); | |
3557 | else if (CP_TYPE_VOLATILE_P (type)) | |
3558 | inform (DECL_SOURCE_LOCATION (r), | |
3559 | "%q#D is volatile", r); | |
3560 | else if (!DECL_INITIAL (r) | |
c8e3e744 | 3561 | || !TREE_CONSTANT (DECL_INITIAL (r)) |
3562 | || !DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r)) | |
09b42213 | 3563 | inform (DECL_SOURCE_LOCATION (r), |
3564 | "%qD was not initialized with a constant " | |
3565 | "expression", r); | |
3566 | else | |
3567 | gcc_unreachable (); | |
3568 | } | |
90ad495b | 3569 | else if (TYPE_REF_P (type)) |
ac6641ca | 3570 | inform (DECL_SOURCE_LOCATION (r), |
3571 | "%qD was not initialized with a constant " | |
3572 | "expression", r); | |
09b42213 | 3573 | else |
3574 | { | |
3575 | if (cxx_dialect >= cxx11 && !DECL_DECLARED_CONSTEXPR_P (r)) | |
3576 | inform (DECL_SOURCE_LOCATION (r), | |
3577 | "%qD was not declared %<constexpr%>", r); | |
3578 | else | |
3579 | inform (DECL_SOURCE_LOCATION (r), | |
3580 | "%qD does not have integral or enumeration type", | |
3581 | r); | |
3582 | } | |
3583 | } | |
3584 | ||
3585 | /* Subroutine of cxx_eval_constant_expression. | |
3586 | Like cxx_eval_unary_expression, except for trinary expressions. */ | |
3587 | ||
3588 | static tree | |
cf72f34d | 3589 | cxx_eval_trinary_expression (const constexpr_ctx *ctx, tree t, |
1227ba74 | 3590 | bool lval, |
09b42213 | 3591 | bool *non_constant_p, bool *overflow_p) |
3592 | { | |
3593 | int i; | |
3594 | tree args[3]; | |
3595 | tree val; | |
3596 | ||
3597 | for (i = 0; i < 3; i++) | |
3598 | { | |
cf72f34d | 3599 | args[i] = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, i), |
1227ba74 | 3600 | lval, |
b2a43197 | 3601 | non_constant_p, overflow_p); |
09b42213 | 3602 | VERIFY_CONSTANT (args[i]); |
3603 | } | |
3604 | ||
3605 | val = fold_ternary_loc (EXPR_LOCATION (t), TREE_CODE (t), TREE_TYPE (t), | |
3606 | args[0], args[1], args[2]); | |
3607 | if (val == NULL_TREE) | |
3608 | return t; | |
3609 | VERIFY_CONSTANT (val); | |
3610 | return val; | |
3611 | } | |
3612 | ||
33603066 | 3613 | /* True if T was declared in a function declared to be constexpr, and |
3614 | therefore potentially constant in C++14. */ | |
3615 | ||
09b42213 | 3616 | bool |
3617 | var_in_constexpr_fn (tree t) | |
3618 | { | |
3619 | tree ctx = DECL_CONTEXT (t); | |
33603066 | 3620 | return (ctx && TREE_CODE (ctx) == FUNCTION_DECL |
09b42213 | 3621 | && DECL_DECLARED_CONSTEXPR_P (ctx)); |
3622 | } | |
3623 | ||
33603066 | 3624 | /* True if T was declared in a function that might be constexpr: either a |
3625 | function that was declared constexpr, or a C++17 lambda op(). */ | |
3626 | ||
3627 | bool | |
3628 | var_in_maybe_constexpr_fn (tree t) | |
3629 | { | |
40e2decb | 3630 | if (cxx_dialect >= cxx17 |
33603066 | 3631 | && DECL_FUNCTION_SCOPE_P (t) |
3632 | && LAMBDA_FUNCTION_P (DECL_CONTEXT (t))) | |
3633 | return true; | |
3634 | return var_in_constexpr_fn (t); | |
3635 | } | |
3636 | ||
93312944 | 3637 | /* We're assigning INIT to TARGET. In do_build_copy_constructor and |
3638 | build_over_call we implement trivial copy of a class with tail padding using | |
3639 | assignment of character arrays, which is valid in normal code, but not in | |
3640 | constexpr evaluation. We don't need to worry about clobbering tail padding | |
3641 | in constexpr evaluation, so strip the type punning. */ | |
3642 | ||
3643 | static void | |
3644 | maybe_simplify_trivial_copy (tree &target, tree &init) | |
3645 | { | |
3646 | if (TREE_CODE (target) == MEM_REF | |
3647 | && TREE_CODE (init) == MEM_REF | |
3648 | && TREE_TYPE (target) == TREE_TYPE (init) | |
3649 | && TREE_CODE (TREE_TYPE (target)) == ARRAY_TYPE | |
3650 | && TREE_TYPE (TREE_TYPE (target)) == unsigned_char_type_node) | |
3651 | { | |
3652 | target = build_fold_indirect_ref (TREE_OPERAND (target, 0)); | |
3653 | init = build_fold_indirect_ref (TREE_OPERAND (init, 0)); | |
3654 | } | |
3655 | } | |
3656 | ||
9c96033c | 3657 | /* Evaluate an INIT_EXPR or MODIFY_EXPR. */ |
3658 | ||
3659 | static tree | |
3660 | cxx_eval_store_expression (const constexpr_ctx *ctx, tree t, | |
1227ba74 | 3661 | bool lval, |
9c96033c | 3662 | bool *non_constant_p, bool *overflow_p) |
3663 | { | |
3664 | constexpr_ctx new_ctx = *ctx; | |
3665 | ||
8a36d0ec | 3666 | tree init = TREE_OPERAND (t, 1); |
3667 | if (TREE_CLOBBER_P (init)) | |
3668 | /* Just ignore clobbers. */ | |
3669 | return void_node; | |
3670 | ||
9c96033c | 3671 | /* First we figure out where we're storing to. */ |
3672 | tree target = TREE_OPERAND (t, 0); | |
93312944 | 3673 | |
3674 | maybe_simplify_trivial_copy (target, init); | |
3675 | ||
9db9fc38 | 3676 | tree type = TREE_TYPE (target); |
6aaacaf1 | 3677 | bool preeval = SCALAR_TYPE_P (type) || TREE_CODE (t) == MODIFY_EXPR; |
3678 | if (preeval) | |
3679 | { | |
3680 | /* Evaluate the value to be stored without knowing what object it will be | |
3681 | stored in, so that any side-effects happen first. */ | |
3682 | if (!SCALAR_TYPE_P (type)) | |
3683 | new_ctx.ctor = new_ctx.object = NULL_TREE; | |
3684 | init = cxx_eval_constant_expression (&new_ctx, init, false, | |
3685 | non_constant_p, overflow_p); | |
3686 | if (*non_constant_p) | |
3687 | return t; | |
3688 | } | |
9c96033c | 3689 | target = cxx_eval_constant_expression (ctx, target, |
f83e6885 | 3690 | true, |
b2a43197 | 3691 | non_constant_p, overflow_p); |
9c96033c | 3692 | if (*non_constant_p) |
3693 | return t; | |
3694 | ||
cf3cefc9 | 3695 | /* cxx_eval_array_reference for lval = true allows references one past |
3696 | end of array, because it does not know if it is just taking address | |
3697 | (which is valid), or actual dereference. Here we know it is | |
3698 | a dereference, so diagnose it here. */ | |
3699 | for (tree probe = target; probe; ) | |
3700 | { | |
3701 | switch (TREE_CODE (probe)) | |
3702 | { | |
3703 | case ARRAY_REF: | |
3704 | tree nelts, ary; | |
3705 | ary = TREE_OPERAND (probe, 0); | |
51f0c7e2 | 3706 | nelts = get_array_or_vector_nelts (ctx, TREE_TYPE (ary), |
3707 | non_constant_p, overflow_p); | |
cf3cefc9 | 3708 | VERIFY_CONSTANT (nelts); |
3709 | gcc_assert (TREE_CODE (nelts) == INTEGER_CST | |
3710 | && TREE_CODE (TREE_OPERAND (probe, 1)) == INTEGER_CST); | |
cb7bca5f | 3711 | if (wi::to_widest (TREE_OPERAND (probe, 1)) == wi::to_widest (nelts)) |
cf3cefc9 | 3712 | { |
3713 | diag_array_subscript (ctx, ary, TREE_OPERAND (probe, 1)); | |
3714 | *non_constant_p = true; | |
3715 | return t; | |
3716 | } | |
3717 | /* FALLTHRU */ | |
3718 | ||
3719 | case BIT_FIELD_REF: | |
3720 | case COMPONENT_REF: | |
3721 | probe = TREE_OPERAND (probe, 0); | |
3722 | continue; | |
3723 | ||
3724 | default: | |
3725 | probe = NULL_TREE; | |
3726 | continue; | |
3727 | } | |
3728 | } | |
3729 | ||
9db9fc38 | 3730 | if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (target), type)) |
3731 | { | |
3732 | /* For initialization of an empty base, the original target will be | |
3733 | *(base*)this, which the above evaluation resolves to the object | |
3734 | argument, which has the derived type rather than the base type. In | |
3735 | this situation, just evaluate the initializer and return, since | |
3736 | there's no actual data to store. */ | |
3737 | gcc_assert (is_empty_class (type)); | |
3738 | return cxx_eval_constant_expression (ctx, init, false, | |
3739 | non_constant_p, overflow_p); | |
3740 | } | |
3741 | ||
9c96033c | 3742 | /* And then find the underlying variable. */ |
3743 | vec<tree,va_gc> *refs = make_tree_vector(); | |
3744 | tree object = NULL_TREE; | |
3745 | for (tree probe = target; object == NULL_TREE; ) | |
3746 | { | |
3747 | switch (TREE_CODE (probe)) | |
3748 | { | |
3749 | case BIT_FIELD_REF: | |
3750 | case COMPONENT_REF: | |
3751 | case ARRAY_REF: | |
3752 | vec_safe_push (refs, TREE_OPERAND (probe, 1)); | |
3753 | vec_safe_push (refs, TREE_TYPE (probe)); | |
3754 | probe = TREE_OPERAND (probe, 0); | |
3755 | break; | |
3756 | ||
3757 | default: | |
3758 | object = probe; | |
9c96033c | 3759 | } |
3760 | } | |
3761 | ||
3762 | /* And then find/build up our initializer for the path to the subobject | |
3763 | we're initializing. */ | |
6fe83e54 | 3764 | tree *valp; |
43b7271d | 3765 | if (object == ctx->object && VAR_P (object) |
3766 | && DECL_NAME (object) && ctx->call == NULL) | |
3767 | /* The variable we're building up an aggregate initializer for is outside | |
3768 | the constant-expression, so don't evaluate the store. We check | |
3769 | DECL_NAME to handle TARGET_EXPR temporaries, which are fair game. */ | |
3770 | valp = NULL; | |
3771 | else if (DECL_P (object)) | |
6fe83e54 | 3772 | valp = ctx->values->get (object); |
3773 | else | |
3774 | valp = NULL; | |
9c96033c | 3775 | if (!valp) |
3776 | { | |
3777 | /* A constant-expression cannot modify objects from outside the | |
3778 | constant-expression. */ | |
f83e6885 | 3779 | if (!ctx->quiet) |
ea034e2c | 3780 | error ("modification of %qE is not a constant expression", object); |
9c96033c | 3781 | *non_constant_p = true; |
3782 | return t; | |
3783 | } | |
9db9fc38 | 3784 | type = TREE_TYPE (object); |
a02b42fe | 3785 | bool no_zero_init = true; |
58b0f9ce | 3786 | |
3787 | vec<tree,va_gc> *ctors = make_tree_vector (); | |
9c96033c | 3788 | while (!refs->is_empty()) |
3789 | { | |
3790 | if (*valp == NULL_TREE) | |
3791 | { | |
3792 | *valp = build_constructor (type, NULL); | |
165d0d5b | 3793 | CONSTRUCTOR_NO_CLEARING (*valp) = no_zero_init; |
9c96033c | 3794 | } |
92fe8840 | 3795 | else if (TREE_CODE (*valp) == STRING_CST) |
3796 | { | |
3797 | /* An array was initialized with a string constant, and now | |
3798 | we're writing into one of its elements. Explode the | |
3799 | single initialization into a set of element | |
3800 | initializations. */ | |
3801 | gcc_assert (TREE_CODE (type) == ARRAY_TYPE); | |
3802 | ||
3803 | tree string = *valp; | |
3804 | tree elt_type = TREE_TYPE (type); | |
3805 | unsigned chars_per_elt = (TYPE_PRECISION (elt_type) | |
3806 | / TYPE_PRECISION (char_type_node)); | |
3807 | unsigned num_elts = TREE_STRING_LENGTH (string) / chars_per_elt; | |
3808 | tree ary_ctor = build_constructor (type, NULL); | |
3809 | ||
3810 | vec_safe_reserve (CONSTRUCTOR_ELTS (ary_ctor), num_elts); | |
3811 | for (unsigned ix = 0; ix != num_elts; ix++) | |
3812 | { | |
3813 | constructor_elt elt = | |
3814 | { | |
3815 | build_int_cst (size_type_node, ix), | |
3816 | extract_string_elt (string, chars_per_elt, ix) | |
3817 | }; | |
3818 | CONSTRUCTOR_ELTS (ary_ctor)->quick_push (elt); | |
3819 | } | |
3820 | ||
3821 | *valp = ary_ctor; | |
3822 | } | |
3823 | ||
a02b42fe | 3824 | /* If the value of object is already zero-initialized, any new ctors for |
3825 | subobjects will also be zero-initialized. */ | |
165d0d5b | 3826 | no_zero_init = CONSTRUCTOR_NO_CLEARING (*valp); |
9c96033c | 3827 | |
58b0f9ce | 3828 | vec_safe_push (ctors, *valp); |
3829 | ||
7963b19d | 3830 | enum tree_code code = TREE_CODE (type); |
9c96033c | 3831 | type = refs->pop(); |
7963b19d | 3832 | tree index = refs->pop(); |
9c96033c | 3833 | |
9c96033c | 3834 | constructor_elt *cep = NULL; |
7963b19d | 3835 | if (code == ARRAY_TYPE) |
3836 | { | |
3837 | HOST_WIDE_INT i | |
3838 | = find_array_ctor_elt (*valp, index, /*insert*/true); | |
3839 | gcc_assert (i >= 0); | |
3840 | cep = CONSTRUCTOR_ELT (*valp, i); | |
3841 | gcc_assert (TREE_CODE (cep->index) != RANGE_EXPR); | |
3842 | } | |
3843 | else | |
3844 | { | |
3845 | gcc_assert (TREE_CODE (index) == FIELD_DECL); | |
13ee2de7 | 3846 | |
3847 | /* We must keep the CONSTRUCTOR's ELTS in FIELD order. | |
3848 | Usually we meet initializers in that order, but it is | |
3849 | possible for base types to be placed not in program | |
3850 | order. */ | |
3851 | tree fields = TYPE_FIELDS (DECL_CONTEXT (index)); | |
3852 | unsigned HOST_WIDE_INT idx; | |
3853 | ||
ef782365 | 3854 | if (code == UNION_TYPE && CONSTRUCTOR_NELTS (*valp) |
3855 | && CONSTRUCTOR_ELT (*valp, 0)->index != index) | |
b47245f1 | 3856 | { |
3857 | if (cxx_dialect < cxx2a) | |
3858 | { | |
3859 | if (!ctx->quiet) | |
3860 | error_at (cp_expr_loc_or_loc (t, input_location), | |
3861 | "change of the active member of a union " | |
3862 | "from %qD to %qD", | |
3863 | CONSTRUCTOR_ELT (*valp, 0)->index, | |
3864 | index); | |
3865 | *non_constant_p = true; | |
3866 | } | |
3867 | /* Changing active member. */ | |
3868 | vec_safe_truncate (CONSTRUCTOR_ELTS (*valp), 0); | |
a165fd90 | 3869 | no_zero_init = true; |
b47245f1 | 3870 | } |
ef782365 | 3871 | |
13ee2de7 | 3872 | for (idx = 0; |
7963b19d | 3873 | vec_safe_iterate (CONSTRUCTOR_ELTS (*valp), idx, &cep); |
13ee2de7 | 3874 | idx++, fields = DECL_CHAIN (fields)) |
7963b19d | 3875 | { |
13ee2de7 | 3876 | if (index == cep->index) |
3877 | goto found; | |
3878 | ||
3879 | /* The field we're initializing must be on the field | |
3880 | list. Look to see if it is present before the | |
3881 | field the current ELT initializes. */ | |
3882 | for (; fields != cep->index; fields = DECL_CHAIN (fields)) | |
3883 | if (index == fields) | |
3884 | goto insert; | |
7963b19d | 3885 | } |
13ee2de7 | 3886 | |
3887 | /* We fell off the end of the CONSTRUCTOR, so insert a new | |
3888 | entry at the end. */ | |
3889 | insert: | |
3890 | { | |
3891 | constructor_elt ce = { index, NULL_TREE }; | |
3892 | ||
3893 | vec_safe_insert (CONSTRUCTOR_ELTS (*valp), idx, ce); | |
3894 | cep = CONSTRUCTOR_ELT (*valp, idx); | |
3895 | } | |
3896 | found:; | |
7963b19d | 3897 | } |
9c96033c | 3898 | valp = &cep->value; |
3899 | } | |
3900 | release_tree_vector (refs); | |
3901 | ||
6aaacaf1 | 3902 | if (!preeval) |
9c96033c | 3903 | { |
3904 | /* Create a new CONSTRUCTOR in case evaluation of the initializer | |
3905 | wants to modify it. */ | |
469dc5a6 | 3906 | if (*valp == NULL_TREE) |
6cded085 | 3907 | { |
6993e708 | 3908 | *valp = build_constructor (type, NULL); |
165d0d5b | 3909 | CONSTRUCTOR_NO_CLEARING (*valp) = no_zero_init; |
6cded085 | 3910 | } |
6993e708 | 3911 | new_ctx.ctor = *valp; |
9c96033c | 3912 | new_ctx.object = target; |
6aaacaf1 | 3913 | init = cxx_eval_constant_expression (&new_ctx, init, false, |
3914 | non_constant_p, overflow_p); | |
3915 | if (target == object) | |
3916 | /* The hash table might have moved since the get earlier. */ | |
3917 | valp = ctx->values->get (object); | |
9c96033c | 3918 | } |
3919 | ||
7b9f713d | 3920 | /* Don't share a CONSTRUCTOR that might be changed later. */ |
e283bb4f | 3921 | init = unshare_constructor (init); |
5579a199 | 3922 | |
6aaacaf1 | 3923 | if (*valp && TREE_CODE (*valp) == CONSTRUCTOR |
3924 | && TREE_CODE (init) == CONSTRUCTOR) | |
469dc5a6 | 3925 | { |
5579a199 | 3926 | /* An outer ctx->ctor might be pointing to *valp, so replace |
3927 | its contents. */ | |
3928 | CONSTRUCTOR_ELTS (*valp) = CONSTRUCTOR_ELTS (init); | |
3929 | TREE_CONSTANT (*valp) = TREE_CONSTANT (init); | |
3930 | TREE_SIDE_EFFECTS (*valp) = TREE_SIDE_EFFECTS (init); | |
165d0d5b | 3931 | CONSTRUCTOR_NO_CLEARING (*valp) |
3932 | = CONSTRUCTOR_NO_CLEARING (init); | |
469dc5a6 | 3933 | } |
9c96033c | 3934 | else |
5579a199 | 3935 | *valp = init; |
58b0f9ce | 3936 | |
5579a199 | 3937 | /* Update TREE_CONSTANT and TREE_SIDE_EFFECTS on enclosing |
3938 | CONSTRUCTORs, if any. */ | |
3939 | tree elt; | |
3940 | unsigned i; | |
3941 | bool c = TREE_CONSTANT (init); | |
3942 | bool s = TREE_SIDE_EFFECTS (init); | |
3943 | if (!c || s) | |
3944 | FOR_EACH_VEC_SAFE_ELT (ctors, i, elt) | |
3945 | { | |
3946 | if (!c) | |
3947 | TREE_CONSTANT (elt) = false; | |
3948 | if (s) | |
3949 | TREE_SIDE_EFFECTS (elt) = true; | |
3950 | } | |
58b0f9ce | 3951 | release_tree_vector (ctors); |
9c96033c | 3952 | |
3953 | if (*non_constant_p) | |
3954 | return t; | |
1227ba74 | 3955 | else if (lval) |
9c96033c | 3956 | return target; |
3957 | else | |
dfac7dd2 | 3958 | return init; |
9c96033c | 3959 | } |
3960 | ||
3961 | /* Evaluate a ++ or -- expression. */ | |
3962 | ||
3963 | static tree | |
3964 | cxx_eval_increment_expression (const constexpr_ctx *ctx, tree t, | |
1227ba74 | 3965 | bool lval, |
9c96033c | 3966 | bool *non_constant_p, bool *overflow_p) |
3967 | { | |
3968 | enum tree_code code = TREE_CODE (t); | |
3969 | tree type = TREE_TYPE (t); | |
3970 | tree op = TREE_OPERAND (t, 0); | |
3971 | tree offset = TREE_OPERAND (t, 1); | |
3972 | gcc_assert (TREE_CONSTANT (offset)); | |
3973 | ||
3974 | /* The operand as an lvalue. */ | |
f83e6885 | 3975 | op = cxx_eval_constant_expression (ctx, op, true, |
b2a43197 | 3976 | non_constant_p, overflow_p); |
9c96033c | 3977 | |
3978 | /* The operand as an rvalue. */ | |
c017458d | 3979 | tree val |
3980 | = cxx_eval_constant_expression (ctx, op, false, | |
3981 | non_constant_p, overflow_p); | |
35f2c28f | 3982 | /* Don't VERIFY_CONSTANT if this might be dealing with a pointer to |
3983 | a local array in a constexpr function. */ | |
d03fa520 | 3984 | bool ptr = INDIRECT_TYPE_P (TREE_TYPE (val)); |
35f2c28f | 3985 | if (!ptr) |
3986 | VERIFY_CONSTANT (val); | |
9c96033c | 3987 | |
3988 | /* The modified value. */ | |
3989 | bool inc = (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR); | |
c8a8f7ad | 3990 | tree mod; |
d03fa520 | 3991 | if (INDIRECT_TYPE_P (type)) |
c8a8f7ad | 3992 | { |
3993 | /* The middle end requires pointers to use POINTER_PLUS_EXPR. */ | |
3994 | offset = convert_to_ptrofftype (offset); | |
3995 | if (!inc) | |
3996 | offset = fold_build1 (NEGATE_EXPR, TREE_TYPE (offset), offset); | |
3997 | mod = fold_build2 (POINTER_PLUS_EXPR, type, val, offset); | |
3998 | } | |
3999 | else | |
4000 | mod = fold_build2 (inc ? PLUS_EXPR : MINUS_EXPR, type, val, offset); | |
35f2c28f | 4001 | if (!ptr) |
4002 | VERIFY_CONSTANT (mod); | |
9c96033c | 4003 | |
4004 | /* Storing the modified value. */ | |
4005 | tree store = build2 (MODIFY_EXPR, type, op, mod); | |
f83e6885 | 4006 | cxx_eval_constant_expression (ctx, store, |
b2a43197 | 4007 | true, non_constant_p, overflow_p); |
9c96033c | 4008 | |
4009 | /* And the value of the expression. */ | |
4010 | if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR) | |
4011 | { | |
4012 | /* Prefix ops are lvalues. */ | |
1227ba74 | 4013 | if (lval) |
9c96033c | 4014 | return op; |
4015 | else | |
4016 | /* But we optimize when the caller wants an rvalue. */ | |
4017 | return mod; | |
4018 | } | |
4019 | else | |
4020 | /* Postfix ops are rvalues. */ | |
4021 | return val; | |
4022 | } | |
4023 | ||
00f21715 | 4024 | /* Predicates for the meaning of *jump_target. */ |
4025 | ||
4026 | static bool | |
4027 | returns (tree *jump_target) | |
4028 | { | |
4029 | return *jump_target | |
d29e4e8c | 4030 | && (TREE_CODE (*jump_target) == RETURN_EXPR |
4031 | || (TREE_CODE (*jump_target) == LABEL_DECL | |
4032 | && LABEL_DECL_CDTOR (*jump_target))); | |
00f21715 | 4033 | } |
4034 | ||
4035 | static bool | |
4036 | breaks (tree *jump_target) | |
4037 | { | |
4038 | return *jump_target | |
cf03ba19 | 4039 | && ((TREE_CODE (*jump_target) == LABEL_DECL |
4040 | && LABEL_DECL_BREAK (*jump_target)) | |
32fee334 | 4041 | || TREE_CODE (*jump_target) == BREAK_STMT |
cf03ba19 | 4042 | || TREE_CODE (*jump_target) == EXIT_EXPR); |
00f21715 | 4043 | } |
4044 | ||
4045 | static bool | |
4046 | continues (tree *jump_target) | |
4047 | { | |
4048 | return *jump_target | |
32fee334 | 4049 | && ((TREE_CODE (*jump_target) == LABEL_DECL |
4050 | && LABEL_DECL_CONTINUE (*jump_target)) | |
4051 | || TREE_CODE (*jump_target) == CONTINUE_STMT); | |
4052 | ||
00f21715 | 4053 | } |
4054 | ||
4055 | static bool | |
4056 | switches (tree *jump_target) | |
4057 | { | |
4058 | return *jump_target | |
4059 | && TREE_CODE (*jump_target) == INTEGER_CST; | |
4060 | } | |
4061 | ||
4062 | /* Subroutine of cxx_eval_statement_list. Determine whether the statement | |
2a2770c6 | 4063 | STMT matches *jump_target. If we're looking for a case label and we see |
4064 | the default label, note it in ctx->css_state. */ | |
00f21715 | 4065 | |
4066 | static bool | |
2a2770c6 | 4067 | label_matches (const constexpr_ctx *ctx, tree *jump_target, tree stmt) |
00f21715 | 4068 | { |
00f21715 | 4069 | switch (TREE_CODE (*jump_target)) |
4070 | { | |
4071 | case LABEL_DECL: | |
4072 | if (TREE_CODE (stmt) == LABEL_EXPR | |
4073 | && LABEL_EXPR_LABEL (stmt) == *jump_target) | |
4074 | return true; | |
4075 | break; | |
4076 | ||
4077 | case INTEGER_CST: | |
4078 | if (TREE_CODE (stmt) == CASE_LABEL_EXPR) | |
4079 | { | |
2a2770c6 | 4080 | gcc_assert (ctx->css_state != NULL); |
00f21715 | 4081 | if (!CASE_LOW (stmt)) |
2a2770c6 | 4082 | { |
4083 | /* default: should appear just once in a SWITCH_EXPR | |
4084 | body (excluding nested SWITCH_EXPR). */ | |
4085 | gcc_assert (*ctx->css_state != css_default_seen); | |
4086 | /* When evaluating SWITCH_EXPR body for the second time, | |
4087 | return true for the default: label. */ | |
4088 | if (*ctx->css_state == css_default_processing) | |
4089 | return true; | |
4090 | *ctx->css_state = css_default_seen; | |
4091 | } | |
83c375ba | 4092 | else if (CASE_HIGH (stmt)) |
4093 | { | |
4094 | if (tree_int_cst_le (CASE_LOW (stmt), *jump_target) | |
4095 | && tree_int_cst_le (*jump_target, CASE_HIGH (stmt))) | |
4096 | return true; | |
4097 | } | |
00f21715 | 4098 | else if (tree_int_cst_equal (*jump_target, CASE_LOW (stmt))) |
4099 | return true; | |
4100 | } | |
4101 | break; | |
4102 | ||
02d7a132 | 4103 | case BREAK_STMT: |
4104 | case CONTINUE_STMT: | |
4105 | /* These two are handled directly in cxx_eval_loop_expr by testing | |
4106 | breaks (jump_target) or continues (jump_target). */ | |
4107 | break; | |
4108 | ||
00f21715 | 4109 | default: |
4110 | gcc_unreachable (); | |
4111 | } | |
4112 | return false; | |
4113 | } | |
4114 | ||
4115 | /* Evaluate a STATEMENT_LIST for side-effects. Handles various jump | |
4116 | semantics, for switch, break, continue, and return. */ | |
4117 | ||
4118 | static tree | |
4119 | cxx_eval_statement_list (const constexpr_ctx *ctx, tree t, | |
00f21715 | 4120 | bool *non_constant_p, bool *overflow_p, |
4121 | tree *jump_target) | |
4122 | { | |
4123 | tree_stmt_iterator i; | |
da7981e0 | 4124 | tree local_target; |
efea7c64 | 4125 | /* In a statement-expression we want to return the last value. |
4126 | For empty statement expression return void_node. */ | |
4127 | tree r = void_node; | |
da7981e0 | 4128 | if (!jump_target) |
4129 | { | |
4130 | local_target = NULL_TREE; | |
4131 | jump_target = &local_target; | |
4132 | } | |
00f21715 | 4133 | for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i)) |
4134 | { | |
00f21715 | 4135 | tree stmt = tsi_stmt (i); |
ba0f90e4 | 4136 | /* We've found a continue, so skip everything until we reach |
4137 | the label its jumping to. */ | |
4138 | if (continues (jump_target)) | |
4139 | { | |
4140 | if (label_matches (ctx, jump_target, stmt)) | |
4141 | /* Found it. */ | |
4142 | *jump_target = NULL_TREE; | |
4143 | else | |
4144 | continue; | |
4145 | } | |
442c4003 | 4146 | if (TREE_CODE (stmt) == DEBUG_BEGIN_STMT) |
4147 | continue; | |
da7981e0 | 4148 | r = cxx_eval_constant_expression (ctx, stmt, false, |
4149 | non_constant_p, overflow_p, | |
4150 | jump_target); | |
00f21715 | 4151 | if (*non_constant_p) |
4152 | break; | |
4153 | if (returns (jump_target) || breaks (jump_target)) | |
4154 | break; | |
4155 | } | |
da7981e0 | 4156 | return r; |
00f21715 | 4157 | } |
4158 | ||
4159 | /* Evaluate a LOOP_EXPR for side-effects. Handles break and return | |
4160 | semantics; continue semantics are covered by cxx_eval_statement_list. */ | |
4161 | ||
4162 | static tree | |
4163 | cxx_eval_loop_expr (const constexpr_ctx *ctx, tree t, | |
00f21715 | 4164 | bool *non_constant_p, bool *overflow_p, |
4165 | tree *jump_target) | |
4166 | { | |
2631cb67 | 4167 | constexpr_ctx new_ctx = *ctx; |
4168 | ||
02d7a132 | 4169 | tree body, cond = NULL_TREE, expr = NULL_TREE; |
21483ab7 | 4170 | int count = 0; |
02d7a132 | 4171 | switch (TREE_CODE (t)) |
4172 | { | |
4173 | case LOOP_EXPR: | |
4174 | body = LOOP_EXPR_BODY (t); | |
4175 | break; | |
4176 | case DO_STMT: | |
4177 | body = DO_BODY (t); | |
4178 | cond = DO_COND (t); | |
4179 | break; | |
4180 | case WHILE_STMT: | |
4181 | body = WHILE_BODY (t); | |
4182 | cond = WHILE_COND (t); | |
4183 | count = -1; | |
4184 | break; | |
4185 | case FOR_STMT: | |
4186 | if (FOR_INIT_STMT (t)) | |
4187 | cxx_eval_constant_expression (ctx, FOR_INIT_STMT (t), /*lval*/false, | |
4188 | non_constant_p, overflow_p, jump_target); | |
4189 | if (*non_constant_p) | |
4190 | return NULL_TREE; | |
4191 | body = FOR_BODY (t); | |
4192 | cond = FOR_COND (t); | |
4193 | expr = FOR_EXPR (t); | |
4194 | count = -1; | |
4195 | break; | |
4196 | default: | |
4197 | gcc_unreachable (); | |
4198 | } | |
d0782a7e | 4199 | auto_vec<tree, 10> save_exprs; |
02d7a132 | 4200 | new_ctx.save_exprs = &save_exprs; |
5370eb8d | 4201 | do |
00f21715 | 4202 | { |
02d7a132 | 4203 | if (count != -1) |
4204 | { | |
4205 | if (body) | |
4206 | cxx_eval_constant_expression (&new_ctx, body, /*lval*/false, | |
4207 | non_constant_p, overflow_p, | |
4208 | jump_target); | |
4209 | if (breaks (jump_target)) | |
4210 | { | |
4211 | *jump_target = NULL_TREE; | |
4212 | break; | |
4213 | } | |
2631cb67 | 4214 | |
02d7a132 | 4215 | if (TREE_CODE (t) != LOOP_EXPR && continues (jump_target)) |
4216 | *jump_target = NULL_TREE; | |
4217 | ||
4218 | if (expr) | |
4219 | cxx_eval_constant_expression (&new_ctx, expr, /*lval*/false, | |
4220 | non_constant_p, overflow_p, | |
4221 | jump_target); | |
4222 | } | |
4223 | ||
4224 | if (cond) | |
4225 | { | |
4226 | tree res | |
4227 | = cxx_eval_constant_expression (&new_ctx, cond, /*lval*/false, | |
4228 | non_constant_p, overflow_p, | |
4229 | jump_target); | |
4230 | if (res) | |
4231 | { | |
4232 | if (verify_constant (res, ctx->quiet, non_constant_p, | |
4233 | overflow_p)) | |
4234 | break; | |
4235 | if (integer_zerop (res)) | |
4236 | break; | |
4237 | } | |
4238 | else | |
4239 | gcc_assert (*jump_target); | |
4240 | } | |
2631cb67 | 4241 | |
4242 | /* Forget saved values of SAVE_EXPRs. */ | |
d0782a7e | 4243 | unsigned int i; |
4244 | tree save_expr; | |
4245 | FOR_EACH_VEC_ELT (save_exprs, i, save_expr) | |
4246 | new_ctx.values->remove (save_expr); | |
4247 | save_exprs.truncate (0); | |
02d7a132 | 4248 | |
21483ab7 | 4249 | if (++count >= constexpr_loop_limit) |
4250 | { | |
4251 | if (!ctx->quiet) | |
d3a3cfb8 | 4252 | error_at (cp_expr_loc_or_loc (t, input_location), |
5967b28b | 4253 | "%<constexpr%> loop iteration count exceeds limit of %d " |
2f6d557f | 4254 | "(use %<-fconstexpr-loop-limit=%> to increase the limit)", |
21483ab7 | 4255 | constexpr_loop_limit); |
4256 | *non_constant_p = true; | |
4257 | break; | |
4258 | } | |
00f21715 | 4259 | } |
2a2770c6 | 4260 | while (!returns (jump_target) |
4261 | && !breaks (jump_target) | |
02d7a132 | 4262 | && !continues (jump_target) |
4263 | && (!switches (jump_target) || count == 0) | |
2a2770c6 | 4264 | && !*non_constant_p); |
5370eb8d | 4265 | |
02d7a132 | 4266 | /* Forget saved values of SAVE_EXPRs. */ |
d0782a7e | 4267 | unsigned int i; |
4268 | tree save_expr; | |
4269 | FOR_EACH_VEC_ELT (save_exprs, i, save_expr) | |
4270 | new_ctx.values->remove (save_expr); | |
2631cb67 | 4271 | |
00f21715 | 4272 | return NULL_TREE; |
4273 | } | |
4274 | ||
4275 | /* Evaluate a SWITCH_EXPR for side-effects. Handles switch and break jump | |
4276 | semantics. */ | |
4277 | ||
4278 | static tree | |
4279 | cxx_eval_switch_expr (const constexpr_ctx *ctx, tree t, | |
00f21715 | 4280 | bool *non_constant_p, bool *overflow_p, |
4281 | tree *jump_target) | |
4282 | { | |
02d7a132 | 4283 | tree cond |
4284 | = TREE_CODE (t) == SWITCH_STMT ? SWITCH_STMT_COND (t) : SWITCH_COND (t); | |
f83e6885 | 4285 | cond = cxx_eval_constant_expression (ctx, cond, false, |
b2a43197 | 4286 | non_constant_p, overflow_p); |
00f21715 | 4287 | VERIFY_CONSTANT (cond); |
4288 | *jump_target = cond; | |
4289 | ||
02d7a132 | 4290 | tree body |
4291 | = TREE_CODE (t) == SWITCH_STMT ? SWITCH_STMT_BODY (t) : SWITCH_BODY (t); | |
2a2770c6 | 4292 | constexpr_ctx new_ctx = *ctx; |
4293 | constexpr_switch_state css = css_default_not_seen; | |
4294 | new_ctx.css_state = &css; | |
4295 | cxx_eval_constant_expression (&new_ctx, body, false, | |
4296 | non_constant_p, overflow_p, jump_target); | |
4297 | if (switches (jump_target) && css == css_default_seen) | |
4298 | { | |
4299 | /* If the SWITCH_EXPR body has default: label, process it once again, | |
4300 | this time instructing label_matches to return true for default: | |
4301 | label on switches (jump_target). */ | |
4302 | css = css_default_processing; | |
4303 | cxx_eval_constant_expression (&new_ctx, body, false, | |
4304 | non_constant_p, overflow_p, jump_target); | |
4305 | } | |
00f21715 | 4306 | if (breaks (jump_target) || switches (jump_target)) |
4307 | *jump_target = NULL_TREE; | |
4308 | return NULL_TREE; | |
4309 | } | |
4310 | ||
85de9604 | 4311 | /* Find the object of TYPE under initialization in CTX. */ |
4312 | ||
4313 | static tree | |
4314 | lookup_placeholder (const constexpr_ctx *ctx, bool lval, tree type) | |
4315 | { | |
def8e41f | 4316 | if (!ctx) |
85de9604 | 4317 | return NULL_TREE; |
4318 | ||
4319 | /* We could use ctx->object unconditionally, but using ctx->ctor when we | |
4320 | can is a minor optimization. */ | |
def8e41f | 4321 | if (!lval && ctx->ctor && same_type_p (TREE_TYPE (ctx->ctor), type)) |
85de9604 | 4322 | return ctx->ctor; |
4323 | ||
def8e41f | 4324 | if (!ctx->object) |
4325 | return NULL_TREE; | |
4326 | ||
85de9604 | 4327 | /* Since an object cannot have a field of its own type, we can search outward |
4328 | from ctx->object to find the unique containing object of TYPE. */ | |
4329 | tree ob = ctx->object; | |
4330 | while (ob) | |
4331 | { | |
4332 | if (same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (ob), type)) | |
4333 | break; | |
4334 | if (handled_component_p (ob)) | |
4335 | ob = TREE_OPERAND (ob, 0); | |
4336 | else | |
4337 | ob = NULL_TREE; | |
4338 | } | |
4339 | ||
4340 | return ob; | |
4341 | } | |
4342 | ||
09b42213 | 4343 | /* Attempt to reduce the expression T to a constant value. |
4344 | On failure, issue diagnostic and return error_mark_node. */ | |
4345 | /* FIXME unify with c_fully_fold */ | |
9c96033c | 4346 | /* FIXME overflow_p is too global */ |
09b42213 | 4347 | |
4348 | static tree | |
cf72f34d | 4349 | cxx_eval_constant_expression (const constexpr_ctx *ctx, tree t, |
1227ba74 | 4350 | bool lval, |
00f21715 | 4351 | bool *non_constant_p, bool *overflow_p, |
32fee334 | 4352 | tree *jump_target /* = NULL */) |
09b42213 | 4353 | { |
cf72f34d | 4354 | constexpr_ctx new_ctx; |
09b42213 | 4355 | tree r = t; |
4356 | ||
2a2770c6 | 4357 | if (jump_target && *jump_target) |
4358 | { | |
4359 | /* If we are jumping, ignore all statements/expressions except those | |
4360 | that could have LABEL_EXPR or CASE_LABEL_EXPR in their bodies. */ | |
4361 | switch (TREE_CODE (t)) | |
4362 | { | |
4363 | case BIND_EXPR: | |
4364 | case STATEMENT_LIST: | |
4365 | case LOOP_EXPR: | |
4366 | case COND_EXPR: | |
02d7a132 | 4367 | case IF_STMT: |
4368 | case DO_STMT: | |
4369 | case WHILE_STMT: | |
4370 | case FOR_STMT: | |
2a2770c6 | 4371 | break; |
4372 | case LABEL_EXPR: | |
4373 | case CASE_LABEL_EXPR: | |
4374 | if (label_matches (ctx, jump_target, t)) | |
4375 | /* Found it. */ | |
4376 | *jump_target = NULL_TREE; | |
4377 | return NULL_TREE; | |
4378 | default: | |
4379 | return NULL_TREE; | |
4380 | } | |
4381 | } | |
32fee334 | 4382 | if (error_operand_p (t)) |
09b42213 | 4383 | { |
4384 | *non_constant_p = true; | |
4385 | return t; | |
4386 | } | |
4387 | if (CONSTANT_CLASS_P (t)) | |
4388 | { | |
c4fa85c9 | 4389 | if (TREE_OVERFLOW (t)) |
4390 | { | |
4391 | if (!ctx->quiet) | |
4392 | permerror (input_location, "overflow in constant expression"); | |
4393 | if (!flag_permissive || ctx->quiet) | |
4394 | *overflow_p = true; | |
4395 | } | |
cb768824 | 4396 | |
4397 | if (TREE_CODE (t) == INTEGER_CST | |
90ad495b | 4398 | && TYPE_PTR_P (TREE_TYPE (t)) |
cb768824 | 4399 | && !integer_zerop (t)) |
4400 | { | |
4401 | if (!ctx->quiet) | |
4402 | error ("value %qE of type %qT is not a constant expression", | |
4403 | t, TREE_TYPE (t)); | |
4404 | *non_constant_p = true; | |
4405 | } | |
4406 | ||
09b42213 | 4407 | return t; |
4408 | } | |
09b42213 | 4409 | |
84f13b2f | 4410 | /* Avoid excessively long constexpr evaluations. */ |
4411 | if (!location_wrapper_p (t) | |
4412 | && ++*ctx->constexpr_ops_count >= constexpr_ops_limit) | |
4413 | { | |
4414 | if (!ctx->quiet) | |
4415 | error_at (cp_expr_loc_or_loc (t, input_location), | |
4416 | "%<constexpr%> evaluation operation count exceeds limit of " | |
4417 | "%wd (use -fconstexpr-ops-limit= to increase the limit)", | |
4418 | constexpr_ops_limit); | |
4419 | *ctx->constexpr_ops_count = INTTYPE_MINIMUM (HOST_WIDE_INT); | |
4420 | *non_constant_p = true; | |
4421 | return t; | |
4422 | } | |
4423 | ||
cb768824 | 4424 | tree_code tcode = TREE_CODE (t); |
4425 | switch (tcode) | |
09b42213 | 4426 | { |
9c96033c | 4427 | case RESULT_DECL: |
1227ba74 | 4428 | if (lval) |
9c96033c | 4429 | return t; |
4430 | /* We ask for an rvalue for the RESULT_DECL when indirecting | |
92a9c89e | 4431 | through an invisible reference, or in named return value |
4432 | optimization. */ | |
8ea8d065 | 4433 | if (tree *p = ctx->values->get (t)) |
4434 | return *p; | |
4435 | else | |
4436 | { | |
4437 | if (!ctx->quiet) | |
4438 | error ("%qE is not a constant expression", t); | |
4439 | *non_constant_p = true; | |
4440 | } | |
4441 | break; | |
9c96033c | 4442 | |
09b42213 | 4443 | case VAR_DECL: |
9c8aeb66 | 4444 | if (DECL_HAS_VALUE_EXPR_P (t)) |
33603066 | 4445 | return cxx_eval_constant_expression (ctx, DECL_VALUE_EXPR (t), |
4446 | lval, non_constant_p, overflow_p); | |
e3533433 | 4447 | /* fall through */ |
8b2b2f24 | 4448 | case CONST_DECL: |
4449 | /* We used to not check lval for CONST_DECL, but darwin.c uses | |
4450 | CONST_DECL for aggregate constants. */ | |
1227ba74 | 4451 | if (lval) |
09b42213 | 4452 | return t; |
594cc00c | 4453 | if (COMPLETE_TYPE_P (TREE_TYPE (t)) |
cd5a9ed1 | 4454 | && is_really_empty_class (TREE_TYPE (t), /*ignore_vptr*/false)) |
c7282bf2 | 4455 | { |
4456 | /* If the class is empty, we aren't actually loading anything. */ | |
4457 | r = build_constructor (TREE_TYPE (t), NULL); | |
4458 | TREE_CONSTANT (r) = true; | |
4459 | } | |
4460 | else if (ctx->strict) | |
2055d27a | 4461 | r = decl_really_constant_value (t); |
4462 | else | |
4463 | r = decl_constant_value (t); | |
09b42213 | 4464 | if (TREE_CODE (r) == TARGET_EXPR |
4465 | && TREE_CODE (TARGET_EXPR_INITIAL (r)) == CONSTRUCTOR) | |
4466 | r = TARGET_EXPR_INITIAL (r); | |
f4ae4202 | 4467 | if (VAR_P (r)) |
cf72f34d | 4468 | if (tree *p = ctx->values->get (r)) |
a143e277 | 4469 | if (*p != NULL_TREE) |
4470 | r = *p; | |
09b42213 | 4471 | if (DECL_P (r)) |
4472 | { | |
f83e6885 | 4473 | if (!ctx->quiet) |
09b42213 | 4474 | non_const_var_error (r); |
4475 | *non_constant_p = true; | |
4476 | } | |
4477 | break; | |
4478 | ||
90567983 | 4479 | case DEBUG_BEGIN_STMT: |
4480 | /* ??? It might be nice to retain this information somehow, so | |
4481 | as to be able to step into a constexpr function call. */ | |
4482 | /* Fall through. */ | |
4483 | ||
09b42213 | 4484 | case FUNCTION_DECL: |
4485 | case TEMPLATE_DECL: | |
4486 | case LABEL_DECL: | |
00f21715 | 4487 | case LABEL_EXPR: |
4488 | case CASE_LABEL_EXPR: | |
2a2770c6 | 4489 | case PREDICT_EXPR: |
09b42213 | 4490 | return t; |
4491 | ||
4492 | case PARM_DECL: | |
90ad495b | 4493 | if (lval && !TYPE_REF_P (TREE_TYPE (t))) |
9c96033c | 4494 | /* glvalue use. */; |
4495 | else if (tree *p = ctx->values->get (r)) | |
4496 | r = *p; | |
1227ba74 | 4497 | else if (lval) |
09b42213 | 4498 | /* Defer in case this is only used for its type. */; |
90ad495b | 4499 | else if (TYPE_REF_P (TREE_TYPE (t))) |
1eb418cc | 4500 | /* Defer, there's no lvalue->rvalue conversion. */; |
53d2f3de | 4501 | else if (COMPLETE_TYPE_P (TREE_TYPE (t)) |
cd5a9ed1 | 4502 | && is_really_empty_class (TREE_TYPE (t), /*ignore_vptr*/false)) |
a6613de7 | 4503 | { |
4504 | /* If the class is empty, we aren't actually loading anything. */ | |
4505 | r = build_constructor (TREE_TYPE (t), NULL); | |
4506 | TREE_CONSTANT (r) = true; | |
4507 | } | |
09b42213 | 4508 | else |
4509 | { | |
f83e6885 | 4510 | if (!ctx->quiet) |
09b42213 | 4511 | error ("%qE is not a constant expression", t); |
4512 | *non_constant_p = true; | |
4513 | } | |
4514 | break; | |
4515 | ||
4516 | case CALL_EXPR: | |
4517 | case AGGR_INIT_EXPR: | |
1227ba74 | 4518 | r = cxx_eval_call_expression (ctx, t, lval, |
09b42213 | 4519 | non_constant_p, overflow_p); |
4520 | break; | |
4521 | ||
9c96033c | 4522 | case DECL_EXPR: |
4523 | { | |
4524 | r = DECL_EXPR_DECL (t); | |
02d7a132 | 4525 | if (TREE_CODE (r) == USING_DECL) |
4526 | { | |
4527 | r = void_node; | |
4528 | break; | |
4529 | } | |
9c96033c | 4530 | if (AGGREGATE_TYPE_P (TREE_TYPE (r)) |
4531 | || VECTOR_TYPE_P (TREE_TYPE (r))) | |
4532 | { | |
4533 | new_ctx = *ctx; | |
4534 | new_ctx.object = r; | |
4535 | new_ctx.ctor = build_constructor (TREE_TYPE (r), NULL); | |
165d0d5b | 4536 | CONSTRUCTOR_NO_CLEARING (new_ctx.ctor) = true; |
9c96033c | 4537 | new_ctx.values->put (r, new_ctx.ctor); |
4538 | ctx = &new_ctx; | |
4539 | } | |
4540 | ||
4541 | if (tree init = DECL_INITIAL (r)) | |
4542 | { | |
4543 | init = cxx_eval_constant_expression (ctx, init, | |
f83e6885 | 4544 | false, |
b2a43197 | 4545 | non_constant_p, overflow_p); |
5898f0d7 | 4546 | /* Don't share a CONSTRUCTOR that might be changed. */ |
e283bb4f | 4547 | init = unshare_constructor (init); |
9c96033c | 4548 | ctx->values->put (r, init); |
4549 | } | |
4550 | else if (ctx == &new_ctx) | |
4551 | /* We gave it a CONSTRUCTOR above. */; | |
4552 | else | |
4553 | ctx->values->put (r, NULL_TREE); | |
4554 | } | |
4555 | break; | |
4556 | ||
09b42213 | 4557 | case TARGET_EXPR: |
4558 | if (!literal_type_p (TREE_TYPE (t))) | |
4559 | { | |
f83e6885 | 4560 | if (!ctx->quiet) |
09b42213 | 4561 | { |
bc35ef65 | 4562 | auto_diagnostic_group d; |
09b42213 | 4563 | error ("temporary of non-literal type %qT in a " |
4564 | "constant expression", TREE_TYPE (t)); | |
4565 | explain_non_literal_class (TREE_TYPE (t)); | |
4566 | } | |
4567 | *non_constant_p = true; | |
4568 | break; | |
4569 | } | |
cf72f34d | 4570 | if ((AGGREGATE_TYPE_P (TREE_TYPE (t)) || VECTOR_TYPE_P (TREE_TYPE (t)))) |
4571 | { | |
4572 | /* We're being expanded without an explicit target, so start | |
4573 | initializing a new object; expansion with an explicit target | |
4574 | strips the TARGET_EXPR before we get here. */ | |
4575 | new_ctx = *ctx; | |
4576 | new_ctx.ctor = build_constructor (TREE_TYPE (t), NULL); | |
165d0d5b | 4577 | CONSTRUCTOR_NO_CLEARING (new_ctx.ctor) = true; |
cf72f34d | 4578 | new_ctx.object = TARGET_EXPR_SLOT (t); |
4579 | ctx->values->put (new_ctx.object, new_ctx.ctor); | |
4580 | ctx = &new_ctx; | |
4581 | } | |
1227ba74 | 4582 | /* Pass false for 'lval' because this indicates |
09b42213 | 4583 | initialization of a temporary. */ |
cf72f34d | 4584 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), |
f83e6885 | 4585 | false, |
b2a43197 | 4586 | non_constant_p, overflow_p); |
09b42213 | 4587 | if (!*non_constant_p) |
4588 | /* Adjust the type of the result to the type of the temporary. */ | |
4589 | r = adjust_temp_type (TREE_TYPE (t), r); | |
1227ba74 | 4590 | if (lval) |
1eb418cc | 4591 | { |
4592 | tree slot = TARGET_EXPR_SLOT (t); | |
e283bb4f | 4593 | r = unshare_constructor (r); |
1eb418cc | 4594 | ctx->values->put (slot, r); |
4595 | return slot; | |
4596 | } | |
09b42213 | 4597 | break; |
4598 | ||
9c96033c | 4599 | case INIT_EXPR: |
9c96033c | 4600 | case MODIFY_EXPR: |
2a2770c6 | 4601 | gcc_assert (jump_target == NULL || *jump_target == NULL_TREE); |
1227ba74 | 4602 | r = cxx_eval_store_expression (ctx, t, lval, |
9c96033c | 4603 | non_constant_p, overflow_p); |
4604 | break; | |
4605 | ||
09b42213 | 4606 | case SCOPE_REF: |
cf72f34d | 4607 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), |
1227ba74 | 4608 | lval, |
b2a43197 | 4609 | non_constant_p, overflow_p); |
09b42213 | 4610 | break; |
4611 | ||
4612 | case RETURN_EXPR: | |
10fb495c | 4613 | if (TREE_OPERAND (t, 0) != NULL_TREE) |
4614 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), | |
4615 | lval, | |
4616 | non_constant_p, overflow_p); | |
02d7a132 | 4617 | /* FALLTHRU */ |
4618 | case BREAK_STMT: | |
4619 | case CONTINUE_STMT: | |
2c572f5f | 4620 | if (jump_target) |
4621 | *jump_target = t; | |
4622 | else | |
4623 | { | |
4624 | /* Can happen with ({ return true; }) && false; passed to | |
4625 | maybe_constant_value. There is nothing to jump over in this | |
4626 | case, and the bug will be diagnosed later. */ | |
4627 | gcc_assert (ctx->quiet); | |
4628 | *non_constant_p = true; | |
4629 | } | |
00f21715 | 4630 | break; |
4631 | ||
e0e672a0 | 4632 | case SAVE_EXPR: |
4633 | /* Avoid evaluating a SAVE_EXPR more than once. */ | |
4634 | if (tree *p = ctx->values->get (t)) | |
4635 | r = *p; | |
4636 | else | |
4637 | { | |
c8f6aeb1 | 4638 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), false, |
e0e672a0 | 4639 | non_constant_p, overflow_p); |
4640 | ctx->values->put (t, r); | |
2631cb67 | 4641 | if (ctx->save_exprs) |
d0782a7e | 4642 | ctx->save_exprs->safe_push (t); |
e0e672a0 | 4643 | } |
4644 | break; | |
4645 | ||
09b42213 | 4646 | case NON_LVALUE_EXPR: |
4647 | case TRY_CATCH_EXPR: | |
7f67d68c | 4648 | case TRY_BLOCK: |
09b42213 | 4649 | case CLEANUP_POINT_EXPR: |
4650 | case MUST_NOT_THROW_EXPR: | |
9c96033c | 4651 | case EXPR_STMT: |
4652 | case EH_SPEC_BLOCK: | |
cf72f34d | 4653 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), |
1227ba74 | 4654 | lval, |
00f21715 | 4655 | non_constant_p, overflow_p, |
4656 | jump_target); | |
09b42213 | 4657 | break; |
4658 | ||
7f67d68c | 4659 | case TRY_FINALLY_EXPR: |
4660 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval, | |
4661 | non_constant_p, overflow_p, | |
4662 | jump_target); | |
4663 | if (!*non_constant_p) | |
4664 | /* Also evaluate the cleanup. */ | |
4665 | cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), true, | |
4666 | non_constant_p, overflow_p, | |
4667 | jump_target); | |
4668 | break; | |
4669 | ||
02d7a132 | 4670 | case CLEANUP_STMT: |
4671 | r = cxx_eval_constant_expression (ctx, CLEANUP_BODY (t), lval, | |
4672 | non_constant_p, overflow_p, | |
4673 | jump_target); | |
4674 | if (!CLEANUP_EH_ONLY (t) && !*non_constant_p) | |
4675 | /* Also evaluate the cleanup. */ | |
4676 | cxx_eval_constant_expression (ctx, CLEANUP_EXPR (t), true, | |
4677 | non_constant_p, overflow_p, | |
4678 | jump_target); | |
4679 | break; | |
4680 | ||
09b42213 | 4681 | /* These differ from cxx_eval_unary_expression in that this doesn't |
4682 | check for a constant operand or result; an address can be | |
4683 | constant without its operand being, and vice versa. */ | |
d2c63826 | 4684 | case MEM_REF: |
09b42213 | 4685 | case INDIRECT_REF: |
1227ba74 | 4686 | r = cxx_eval_indirect_ref (ctx, t, lval, |
09b42213 | 4687 | non_constant_p, overflow_p); |
4688 | break; | |
4689 | ||
4690 | case ADDR_EXPR: | |
4691 | { | |
4692 | tree oldop = TREE_OPERAND (t, 0); | |
cf72f34d | 4693 | tree op = cxx_eval_constant_expression (ctx, oldop, |
1227ba74 | 4694 | /*lval*/true, |
b2a43197 | 4695 | non_constant_p, overflow_p); |
09b42213 | 4696 | /* Don't VERIFY_CONSTANT here. */ |
4697 | if (*non_constant_p) | |
4698 | return t; | |
1eb418cc | 4699 | gcc_checking_assert (TREE_CODE (op) != CONSTRUCTOR); |
09b42213 | 4700 | /* This function does more aggressive folding than fold itself. */ |
4701 | r = build_fold_addr_expr_with_type (op, TREE_TYPE (t)); | |
4702 | if (TREE_CODE (r) == ADDR_EXPR && TREE_OPERAND (r, 0) == oldop) | |
4703 | return t; | |
4704 | break; | |
4705 | } | |
4706 | ||
4707 | case REALPART_EXPR: | |
4708 | case IMAGPART_EXPR: | |
6fe424c2 | 4709 | if (lval) |
4710 | { | |
4711 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval, | |
4712 | non_constant_p, overflow_p); | |
4713 | if (r == error_mark_node) | |
4714 | ; | |
4715 | else if (r == TREE_OPERAND (t, 0)) | |
4716 | r = t; | |
4717 | else | |
4718 | r = fold_build1 (TREE_CODE (t), TREE_TYPE (t), r); | |
4719 | break; | |
4720 | } | |
4721 | /* FALLTHRU */ | |
09b42213 | 4722 | case CONJ_EXPR: |
4723 | case FIX_TRUNC_EXPR: | |
4724 | case FLOAT_EXPR: | |
4725 | case NEGATE_EXPR: | |
4726 | case ABS_EXPR: | |
19b4138e | 4727 | case ABSU_EXPR: |
09b42213 | 4728 | case BIT_NOT_EXPR: |
4729 | case TRUTH_NOT_EXPR: | |
4730 | case FIXED_CONVERT_EXPR: | |
1227ba74 | 4731 | r = cxx_eval_unary_expression (ctx, t, lval, |
09b42213 | 4732 | non_constant_p, overflow_p); |
4733 | break; | |
4734 | ||
4735 | case SIZEOF_EXPR: | |
02d7a132 | 4736 | r = cxx_eval_constant_expression (ctx, fold_sizeof_expr (t), lval, |
4737 | non_constant_p, overflow_p, | |
4738 | jump_target); | |
09b42213 | 4739 | break; |
4740 | ||
4741 | case COMPOUND_EXPR: | |
4742 | { | |
4743 | /* check_return_expr sometimes wraps a TARGET_EXPR in a | |
4744 | COMPOUND_EXPR; don't get confused. Also handle EMPTY_CLASS_EXPR | |
4745 | introduced by build_call_a. */ | |
4746 | tree op0 = TREE_OPERAND (t, 0); | |
4747 | tree op1 = TREE_OPERAND (t, 1); | |
4748 | STRIP_NOPS (op1); | |
4749 | if ((TREE_CODE (op0) == TARGET_EXPR && op1 == TARGET_EXPR_SLOT (op0)) | |
4750 | || TREE_CODE (op1) == EMPTY_CLASS_EXPR) | |
f83e6885 | 4751 | r = cxx_eval_constant_expression (ctx, op0, |
1227ba74 | 4752 | lval, non_constant_p, overflow_p, |
00f21715 | 4753 | jump_target); |
09b42213 | 4754 | else |
4755 | { | |
4756 | /* Check that the LHS is constant and then discard it. */ | |
f83e6885 | 4757 | cxx_eval_constant_expression (ctx, op0, |
c8f6aeb1 | 4758 | true, non_constant_p, overflow_p, |
00f21715 | 4759 | jump_target); |
cf03ba19 | 4760 | if (*non_constant_p) |
4761 | return t; | |
09b42213 | 4762 | op1 = TREE_OPERAND (t, 1); |
f83e6885 | 4763 | r = cxx_eval_constant_expression (ctx, op1, |
1227ba74 | 4764 | lval, non_constant_p, overflow_p, |
00f21715 | 4765 | jump_target); |
09b42213 | 4766 | } |
4767 | } | |
4768 | break; | |
4769 | ||
4770 | case POINTER_PLUS_EXPR: | |
57e83b58 | 4771 | case POINTER_DIFF_EXPR: |
09b42213 | 4772 | case PLUS_EXPR: |
4773 | case MINUS_EXPR: | |
4774 | case MULT_EXPR: | |
4775 | case TRUNC_DIV_EXPR: | |
4776 | case CEIL_DIV_EXPR: | |
4777 | case FLOOR_DIV_EXPR: | |
4778 | case ROUND_DIV_EXPR: | |
4779 | case TRUNC_MOD_EXPR: | |
4780 | case CEIL_MOD_EXPR: | |
4781 | case ROUND_MOD_EXPR: | |
4782 | case RDIV_EXPR: | |
4783 | case EXACT_DIV_EXPR: | |
4784 | case MIN_EXPR: | |
4785 | case MAX_EXPR: | |
4786 | case LSHIFT_EXPR: | |
4787 | case RSHIFT_EXPR: | |
4788 | case LROTATE_EXPR: | |
4789 | case RROTATE_EXPR: | |
4790 | case BIT_IOR_EXPR: | |
4791 | case BIT_XOR_EXPR: | |
4792 | case BIT_AND_EXPR: | |
4793 | case TRUTH_XOR_EXPR: | |
4794 | case LT_EXPR: | |
4795 | case LE_EXPR: | |
4796 | case GT_EXPR: | |
4797 | case GE_EXPR: | |
4798 | case EQ_EXPR: | |
4799 | case NE_EXPR: | |
4800 | case UNORDERED_EXPR: | |
4801 | case ORDERED_EXPR: | |
4802 | case UNLT_EXPR: | |
4803 | case UNLE_EXPR: | |
4804 | case UNGT_EXPR: | |
4805 | case UNGE_EXPR: | |
4806 | case UNEQ_EXPR: | |
4807 | case LTGT_EXPR: | |
4808 | case RANGE_EXPR: | |
4809 | case COMPLEX_EXPR: | |
1227ba74 | 4810 | r = cxx_eval_binary_expression (ctx, t, lval, |
09b42213 | 4811 | non_constant_p, overflow_p); |
4812 | break; | |
4813 | ||
4814 | /* fold can introduce non-IF versions of these; still treat them as | |
4815 | short-circuiting. */ | |
4816 | case TRUTH_AND_EXPR: | |
4817 | case TRUTH_ANDIF_EXPR: | |
cf72f34d | 4818 | r = cxx_eval_logical_expression (ctx, t, boolean_false_node, |
09b42213 | 4819 | boolean_true_node, |
1227ba74 | 4820 | lval, |
09b42213 | 4821 | non_constant_p, overflow_p); |
4822 | break; | |
4823 | ||
4824 | case TRUTH_OR_EXPR: | |
4825 | case TRUTH_ORIF_EXPR: | |
cf72f34d | 4826 | r = cxx_eval_logical_expression (ctx, t, boolean_true_node, |
09b42213 | 4827 | boolean_false_node, |
1227ba74 | 4828 | lval, |
09b42213 | 4829 | non_constant_p, overflow_p); |
4830 | break; | |
4831 | ||
4832 | case ARRAY_REF: | |
1227ba74 | 4833 | r = cxx_eval_array_reference (ctx, t, lval, |
09b42213 | 4834 | non_constant_p, overflow_p); |
4835 | break; | |
4836 | ||
4837 | case COMPONENT_REF: | |
4838 | if (is_overloaded_fn (t)) | |
4839 | { | |
4840 | /* We can only get here in checking mode via | |
4841 | build_non_dependent_expr, because any expression that | |
4842 | calls or takes the address of the function will have | |
4843 | pulled a FUNCTION_DECL out of the COMPONENT_REF. */ | |
f83e6885 | 4844 | gcc_checking_assert (ctx->quiet || errorcount); |
09b42213 | 4845 | *non_constant_p = true; |
4846 | return t; | |
4847 | } | |
1227ba74 | 4848 | r = cxx_eval_component_reference (ctx, t, lval, |
09b42213 | 4849 | non_constant_p, overflow_p); |
4850 | break; | |
4851 | ||
4852 | case BIT_FIELD_REF: | |
1227ba74 | 4853 | r = cxx_eval_bit_field_ref (ctx, t, lval, |
09b42213 | 4854 | non_constant_p, overflow_p); |
4855 | break; | |
4856 | ||
4857 | case COND_EXPR: | |
02d7a132 | 4858 | case IF_STMT: |
2a2770c6 | 4859 | if (jump_target && *jump_target) |
4860 | { | |
f1329be6 | 4861 | tree orig_jump = *jump_target; |
02d7a132 | 4862 | tree arg = ((TREE_CODE (t) != IF_STMT || TREE_OPERAND (t, 1)) |
4863 | ? TREE_OPERAND (t, 1) : void_node); | |
2a2770c6 | 4864 | /* When jumping to a label, the label might be either in the |
4865 | then or else blocks, so process then block first in skipping | |
4866 | mode first, and if we are still in the skipping mode at its end, | |
4867 | process the else block too. */ | |
02d7a132 | 4868 | r = cxx_eval_constant_expression (ctx, arg, lval, non_constant_p, |
4869 | overflow_p, jump_target); | |
f1329be6 | 4870 | /* It's possible that we found the label in the then block. But |
4871 | it could have been followed by another jumping statement, e.g. | |
4872 | say we're looking for case 1: | |
4873 | if (cond) | |
4874 | { | |
4875 | // skipped statements | |
4876 | case 1:; // clears up *jump_target | |
4877 | return 1; // and sets it to a RETURN_EXPR | |
4878 | } | |
4879 | else { ... } | |
4880 | in which case we need not go looking to the else block. | |
4881 | (goto is not allowed in a constexpr function.) */ | |
4882 | if (*jump_target == orig_jump) | |
02d7a132 | 4883 | { |
4884 | arg = ((TREE_CODE (t) != IF_STMT || TREE_OPERAND (t, 2)) | |
4885 | ? TREE_OPERAND (t, 2) : void_node); | |
4886 | r = cxx_eval_constant_expression (ctx, arg, lval, non_constant_p, | |
4887 | overflow_p, jump_target); | |
4888 | } | |
2a2770c6 | 4889 | break; |
4890 | } | |
1227ba74 | 4891 | r = cxx_eval_conditional_expression (ctx, t, lval, |
00f21715 | 4892 | non_constant_p, overflow_p, |
4893 | jump_target); | |
09b42213 | 4894 | break; |
31595caf | 4895 | case VEC_COND_EXPR: |
4896 | r = cxx_eval_vector_conditional_expression (ctx, t, non_constant_p, | |
4897 | overflow_p); | |
4898 | break; | |
09b42213 | 4899 | |
4900 | case CONSTRUCTOR: | |
8f46b677 | 4901 | if (TREE_CONSTANT (t) && reduced_constant_expression_p (t)) |
58b0f9ce | 4902 | { |
4903 | /* Don't re-process a constant CONSTRUCTOR, but do fold it to | |
4904 | VECTOR_CST if applicable. */ | |
79e65a6b | 4905 | verify_constructor_flags (t); |
58b0f9ce | 4906 | if (TREE_CONSTANT (t)) |
4907 | return fold (t); | |
4908 | } | |
1227ba74 | 4909 | r = cxx_eval_bare_aggregate (ctx, t, lval, |
09b42213 | 4910 | non_constant_p, overflow_p); |
4911 | break; | |
4912 | ||
4913 | case VEC_INIT_EXPR: | |
4914 | /* We can get this in a defaulted constructor for a class with a | |
4915 | non-static data member of array type. Either the initializer will | |
4916 | be NULL, meaning default-initialization, or it will be an lvalue | |
4917 | or xvalue of the same type, meaning direct-initialization from the | |
4918 | corresponding member. */ | |
1227ba74 | 4919 | r = cxx_eval_vec_init (ctx, t, lval, |
09b42213 | 4920 | non_constant_p, overflow_p); |
4921 | break; | |
4922 | ||
09b42213 | 4923 | case VEC_PERM_EXPR: |
1227ba74 | 4924 | r = cxx_eval_trinary_expression (ctx, t, lval, |
09b42213 | 4925 | non_constant_p, overflow_p); |
4926 | break; | |
4927 | ||
941fafa5 | 4928 | case NOP_EXPR: |
4929 | if (REINTERPRET_CAST_P (t)) | |
4930 | { | |
4931 | if (!ctx->quiet) | |
d3a3cfb8 | 4932 | error_at (cp_expr_loc_or_loc (t, input_location), |
941fafa5 | 4933 | "a reinterpret_cast is not a constant expression"); |
4934 | *non_constant_p = true; | |
4935 | return t; | |
4936 | } | |
4937 | /* FALLTHROUGH. */ | |
09b42213 | 4938 | case CONVERT_EXPR: |
4939 | case VIEW_CONVERT_EXPR: | |
d2c63826 | 4940 | case UNARY_PLUS_EXPR: |
09b42213 | 4941 | { |
4942 | tree oldop = TREE_OPERAND (t, 0); | |
d2c63826 | 4943 | |
cf72f34d | 4944 | tree op = cxx_eval_constant_expression (ctx, oldop, |
1227ba74 | 4945 | lval, |
b2a43197 | 4946 | non_constant_p, overflow_p); |
09b42213 | 4947 | if (*non_constant_p) |
4948 | return t; | |
f16ed232 | 4949 | tree type = TREE_TYPE (t); |
4950 | if (TREE_CODE (op) == PTRMEM_CST | |
4951 | && !TYPE_PTRMEM_P (type)) | |
4952 | op = cplus_expand_constant (op); | |
941fafa5 | 4953 | |
6a9b35ef | 4954 | if (TREE_CODE (op) == PTRMEM_CST && tcode == NOP_EXPR) |
4955 | { | |
941fafa5 | 4956 | if (!same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (op)) |
4957 | && !can_convert_qual (type, op)) | |
4958 | op = cplus_expand_constant (op); | |
4959 | return cp_fold_convert (type, op); | |
6a9b35ef | 4960 | } |
cb768824 | 4961 | |
d03fa520 | 4962 | if (INDIRECT_TYPE_P (type) && TREE_CODE (op) == INTEGER_CST) |
09b42213 | 4963 | { |
cb768824 | 4964 | if (integer_zerop (op)) |
4965 | { | |
90ad495b | 4966 | if (TYPE_REF_P (type)) |
cb768824 | 4967 | { |
4968 | if (!ctx->quiet) | |
d3a3cfb8 | 4969 | error_at (cp_expr_loc_or_loc (t, input_location), |
cb768824 | 4970 | "dereferencing a null pointer"); |
4971 | *non_constant_p = true; | |
4972 | return t; | |
4973 | } | |
90ad495b | 4974 | else if (TYPE_PTR_P (TREE_TYPE (op))) |
cb768824 | 4975 | { |
4976 | tree from = TREE_TYPE (op); | |
4977 | ||
4978 | if (!can_convert (type, from, tf_none)) | |
4979 | { | |
4980 | if (!ctx->quiet) | |
d3a3cfb8 | 4981 | error_at (cp_expr_loc_or_loc (t, input_location), |
cb768824 | 4982 | "conversion of %qT null pointer to %qT " |
4983 | "is not a constant expression", | |
4984 | from, type); | |
4985 | *non_constant_p = true; | |
4986 | return t; | |
4987 | } | |
4988 | } | |
4989 | } | |
4990 | else | |
4991 | { | |
4992 | /* This detects for example: | |
4993 | reinterpret_cast<void*>(sizeof 0) | |
4994 | */ | |
4995 | if (!ctx->quiet) | |
d3a3cfb8 | 4996 | error_at (cp_expr_loc_or_loc (t, input_location), |
cb768824 | 4997 | "%<reinterpret_cast<%T>(%E)%> is not " |
ea034e2c | 4998 | "a constant expression", |
cb768824 | 4999 | type, op); |
5000 | *non_constant_p = true; | |
5001 | return t; | |
5002 | } | |
09b42213 | 5003 | } |
941fafa5 | 5004 | |
d2c63826 | 5005 | if (op == oldop && tcode != UNARY_PLUS_EXPR) |
09b42213 | 5006 | /* We didn't fold at the top so we could check for ptr-int |
5007 | conversion. */ | |
5008 | return fold (t); | |
941fafa5 | 5009 | |
6b53d686 | 5010 | /* Handle an array's bounds having been deduced after we built |
5011 | the wrapping expression. */ | |
5012 | if (same_type_ignoring_tlq_and_bounds_p (type, TREE_TYPE (op))) | |
5013 | r = op; | |
5014 | else if (tcode == UNARY_PLUS_EXPR) | |
d2c63826 | 5015 | r = fold_convert (TREE_TYPE (t), op); |
5016 | else | |
5017 | r = fold_build1 (tcode, type, op); | |
941fafa5 | 5018 | |
09b42213 | 5019 | /* Conversion of an out-of-range value has implementation-defined |
5020 | behavior; the language considers it different from arithmetic | |
5021 | overflow, which is undefined. */ | |
5022 | if (TREE_OVERFLOW_P (r) && !TREE_OVERFLOW_P (op)) | |
5023 | TREE_OVERFLOW (r) = false; | |
5024 | } | |
5025 | break; | |
5026 | ||
5027 | case EMPTY_CLASS_EXPR: | |
5028 | /* This is good enough for a function argument that might not get | |
5029 | used, and they can't do anything with it, so just return it. */ | |
5030 | return t; | |
5031 | ||
9c96033c | 5032 | case STATEMENT_LIST: |
00f21715 | 5033 | new_ctx = *ctx; |
5034 | new_ctx.ctor = new_ctx.object = NULL_TREE; | |
f83e6885 | 5035 | return cxx_eval_statement_list (&new_ctx, t, |
00f21715 | 5036 | non_constant_p, overflow_p, jump_target); |
9c96033c | 5037 | |
5038 | case BIND_EXPR: | |
5039 | return cxx_eval_constant_expression (ctx, BIND_EXPR_BODY (t), | |
1227ba74 | 5040 | lval, |
00f21715 | 5041 | non_constant_p, overflow_p, |
5042 | jump_target); | |
9c96033c | 5043 | |
09b42213 | 5044 | case PREINCREMENT_EXPR: |
5045 | case POSTINCREMENT_EXPR: | |
5046 | case PREDECREMENT_EXPR: | |
5047 | case POSTDECREMENT_EXPR: | |
f83e6885 | 5048 | return cxx_eval_increment_expression (ctx, t, |
1227ba74 | 5049 | lval, non_constant_p, overflow_p); |
9c96033c | 5050 | |
5051 | case LAMBDA_EXPR: | |
09b42213 | 5052 | case NEW_EXPR: |
5053 | case VEC_NEW_EXPR: | |
5054 | case DELETE_EXPR: | |
5055 | case VEC_DELETE_EXPR: | |
5056 | case THROW_EXPR: | |
09b42213 | 5057 | case MODOP_EXPR: |
5058 | /* GCC internal stuff. */ | |
5059 | case VA_ARG_EXPR: | |
09b42213 | 5060 | case NON_DEPENDENT_EXPR: |
5061 | case BASELINK: | |
09b42213 | 5062 | case OFFSET_REF: |
f83e6885 | 5063 | if (!ctx->quiet) |
d3a3cfb8 | 5064 | error_at (cp_expr_loc_or_loc (t, input_location), |
ea034e2c | 5065 | "expression %qE is not a constant expression", t); |
09b42213 | 5066 | *non_constant_p = true; |
5067 | break; | |
5068 | ||
bb6e576c | 5069 | case OBJ_TYPE_REF: |
5070 | { | |
5071 | /* Virtual function call. Let the constexpr machinery figure out | |
5072 | the dynamic type. */ | |
5073 | int token = tree_to_shwi (OBJ_TYPE_REF_TOKEN (t)); | |
5074 | tree obj = OBJ_TYPE_REF_OBJECT (t); | |
5075 | obj = cxx_eval_constant_expression (ctx, obj, lval, non_constant_p, | |
5076 | overflow_p); | |
5077 | /* We expect something in the form of &x.D.2103.D.2094; get x. */ | |
85c4b1bb | 5078 | if (TREE_CODE (obj) != ADDR_EXPR |
5079 | || !DECL_P (get_base_address (TREE_OPERAND (obj, 0)))) | |
bb6e576c | 5080 | { |
5081 | if (!ctx->quiet) | |
5082 | error_at (cp_expr_loc_or_loc (t, input_location), | |
5083 | "expression %qE is not a constant expression", t); | |
5084 | *non_constant_p = true; | |
5085 | return t; | |
5086 | } | |
5087 | obj = TREE_OPERAND (obj, 0); | |
e3cb8102 | 5088 | while (TREE_CODE (obj) == COMPONENT_REF |
5089 | && DECL_FIELD_IS_BASE (TREE_OPERAND (obj, 1))) | |
bb6e576c | 5090 | obj = TREE_OPERAND (obj, 0); |
5091 | tree objtype = TREE_TYPE (obj); | |
5092 | /* Find the function decl in the virtual functions list. TOKEN is | |
5093 | the DECL_VINDEX that says which function we're looking for. */ | |
5094 | tree virtuals = BINFO_VIRTUALS (TYPE_BINFO (objtype)); | |
9a97d94a | 5095 | if (TARGET_VTABLE_USES_DESCRIPTORS) |
5096 | token /= MAX (TARGET_VTABLE_USES_DESCRIPTORS, 1); | |
bb6e576c | 5097 | r = TREE_VALUE (chain_index (token, virtuals)); |
5098 | break; | |
5099 | } | |
5100 | ||
cf72f34d | 5101 | case PLACEHOLDER_EXPR: |
85de9604 | 5102 | /* Use of the value or address of the current object. */ |
5103 | if (tree ctor = lookup_placeholder (ctx, lval, TREE_TYPE (t))) | |
5104 | return cxx_eval_constant_expression (ctx, ctor, lval, | |
5105 | non_constant_p, overflow_p); | |
5106 | /* A placeholder without a referent. We can get here when | |
5107 | checking whether NSDMIs are noexcept, or in massage_init_elt; | |
5108 | just say it's non-constant for now. */ | |
5109 | gcc_assert (ctx->quiet); | |
5110 | *non_constant_p = true; | |
cf72f34d | 5111 | break; |
5112 | ||
cf03ba19 | 5113 | case EXIT_EXPR: |
5114 | { | |
5115 | tree cond = TREE_OPERAND (t, 0); | |
5116 | cond = cxx_eval_constant_expression (ctx, cond, /*lval*/false, | |
5117 | non_constant_p, overflow_p); | |
5118 | VERIFY_CONSTANT (cond); | |
5119 | if (integer_nonzerop (cond)) | |
5120 | *jump_target = t; | |
5121 | } | |
5122 | break; | |
5123 | ||
9c96033c | 5124 | case GOTO_EXPR: |
00f21715 | 5125 | *jump_target = TREE_OPERAND (t, 0); |
d29e4e8c | 5126 | gcc_assert (breaks (jump_target) || continues (jump_target) |
5127 | /* Allow for jumping to a cdtor_label. */ | |
5128 | || returns (jump_target)); | |
00f21715 | 5129 | break; |
5130 | ||
9c96033c | 5131 | case LOOP_EXPR: |
02d7a132 | 5132 | case DO_STMT: |
5133 | case WHILE_STMT: | |
5134 | case FOR_STMT: | |
f83e6885 | 5135 | cxx_eval_loop_expr (ctx, t, |
00f21715 | 5136 | non_constant_p, overflow_p, jump_target); |
5137 | break; | |
5138 | ||
9c96033c | 5139 | case SWITCH_EXPR: |
02d7a132 | 5140 | case SWITCH_STMT: |
f83e6885 | 5141 | cxx_eval_switch_expr (ctx, t, |
00f21715 | 5142 | non_constant_p, overflow_p, jump_target); |
9c96033c | 5143 | break; |
5144 | ||
56c12fd4 | 5145 | case REQUIRES_EXPR: |
5146 | /* It's possible to get a requires-expression in a constant | |
5147 | expression. For example: | |
5148 | ||
5149 | template<typename T> concept bool C() { | |
5150 | return requires (T t) { t; }; | |
5151 | } | |
5152 | ||
5153 | template<typename T> requires !C<T>() void f(T); | |
5154 | ||
5155 | Normalization leaves f with the associated constraint | |
5156 | '!requires (T t) { ... }' which is not transformed into | |
5157 | a constraint. */ | |
5158 | if (!processing_template_decl) | |
5159 | return evaluate_constraint_expression (t, NULL_TREE); | |
5160 | else | |
5161 | *non_constant_p = true; | |
5162 | return t; | |
5163 | ||
24c6ee98 | 5164 | case ANNOTATE_EXPR: |
24c6ee98 | 5165 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), |
5166 | lval, | |
5167 | non_constant_p, overflow_p, | |
5168 | jump_target); | |
5169 | break; | |
5170 | ||
7285637a | 5171 | case USING_STMT: |
5172 | r = void_node; | |
5173 | break; | |
5174 | ||
09b42213 | 5175 | default: |
b9a3af23 | 5176 | if (STATEMENT_CODE_P (TREE_CODE (t))) |
5177 | { | |
5178 | /* This function doesn't know how to deal with pre-genericize | |
5179 | statements; this can only happen with statement-expressions, | |
5180 | so for now just fail. */ | |
5181 | if (!ctx->quiet) | |
5182 | error_at (EXPR_LOCATION (t), | |
ea034e2c | 5183 | "statement is not a constant expression"); |
b9a3af23 | 5184 | } |
5185 | else | |
5186 | internal_error ("unexpected expression %qE of kind %s", t, | |
5187 | get_tree_code_name (TREE_CODE (t))); | |
09b42213 | 5188 | *non_constant_p = true; |
5189 | break; | |
5190 | } | |
5191 | ||
5192 | if (r == error_mark_node) | |
5193 | *non_constant_p = true; | |
5194 | ||
5195 | if (*non_constant_p) | |
5196 | return t; | |
5197 | else | |
5198 | return r; | |
5199 | } | |
5200 | ||
6e1bbaae | 5201 | /* P0859: A function is needed for constant evaluation if it is a constexpr |
5202 | function that is named by an expression ([basic.def.odr]) that is | |
5203 | potentially constant evaluated. | |
5204 | ||
5205 | So we need to instantiate any constexpr functions mentioned by the | |
5206 | expression even if the definition isn't needed for evaluating the | |
5207 | expression. */ | |
5208 | ||
5209 | static tree | |
5210 | instantiate_cx_fn_r (tree *tp, int *walk_subtrees, void */*data*/) | |
5211 | { | |
5212 | if (TREE_CODE (*tp) == FUNCTION_DECL | |
5213 | && DECL_DECLARED_CONSTEXPR_P (*tp) | |
5214 | && !DECL_INITIAL (*tp) | |
eed138cf | 5215 | && !trivial_fn_p (*tp) |
6e1bbaae | 5216 | && DECL_TEMPLOID_INSTANTIATION (*tp)) |
5217 | { | |
5218 | ++function_depth; | |
5219 | instantiate_decl (*tp, /*defer_ok*/false, /*expl_inst*/false); | |
5220 | --function_depth; | |
5221 | } | |
5222 | else if (TREE_CODE (*tp) == CALL_EXPR | |
5223 | || TREE_CODE (*tp) == AGGR_INIT_EXPR) | |
5224 | { | |
5225 | if (EXPR_HAS_LOCATION (*tp)) | |
5226 | input_location = EXPR_LOCATION (*tp); | |
5227 | } | |
5228 | ||
5229 | if (!EXPR_P (*tp)) | |
5230 | *walk_subtrees = 0; | |
5231 | ||
5232 | return NULL_TREE; | |
5233 | } | |
5234 | static void | |
5235 | instantiate_constexpr_fns (tree t) | |
5236 | { | |
5237 | location_t loc = input_location; | |
5238 | cp_walk_tree_without_duplicates (&t, instantiate_cx_fn_r, NULL); | |
5239 | input_location = loc; | |
5240 | } | |
5241 | ||
18d371d3 | 5242 | /* ALLOW_NON_CONSTANT is false if T is required to be a constant expression. |
3f892eaf | 5243 | STRICT has the same sense as for constant_value_1: true if we only allow |
5244 | conforming C++ constant expressions, or false if we want a constant value | |
5245 | even if it doesn't conform. | |
1562c831 | 5246 | MANIFESTLY_CONST_EVAL is true if T is manifestly const-evaluated as |
18d371d3 | 5247 | per P0595 even when ALLOW_NON_CONSTANT is true. */ |
5248 | ||
09b42213 | 5249 | static tree |
cf72f34d | 5250 | cxx_eval_outermost_constant_expr (tree t, bool allow_non_constant, |
18d371d3 | 5251 | bool strict = true, |
1562c831 | 5252 | bool manifestly_const_eval = false, |
18d371d3 | 5253 | tree object = NULL_TREE) |
09b42213 | 5254 | { |
c300fe28 | 5255 | auto_timevar time (TV_CONSTEXPR); |
5256 | ||
09b42213 | 5257 | bool non_constant_p = false; |
5258 | bool overflow_p = false; | |
cf72f34d | 5259 | hash_map<tree,tree> map; |
84f13b2f | 5260 | HOST_WIDE_INT constexpr_ctx_count = 0; |
2631cb67 | 5261 | |
2a2770c6 | 5262 | constexpr_ctx ctx = { NULL, &map, NULL, NULL, NULL, NULL, |
84f13b2f | 5263 | &constexpr_ctx_count, allow_non_constant, strict, |
1562c831 | 5264 | manifestly_const_eval || !allow_non_constant }; |
2631cb67 | 5265 | |
cf72f34d | 5266 | tree type = initialized_type (t); |
cf72f34d | 5267 | tree r = t; |
48c03f15 | 5268 | if (VOID_TYPE_P (type)) |
5269 | return t; | |
cf72f34d | 5270 | if (AGGREGATE_TYPE_P (type) || VECTOR_TYPE_P (type)) |
5271 | { | |
5272 | /* In C++14 an NSDMI can participate in aggregate initialization, | |
5273 | and can refer to the address of the object being initialized, so | |
5274 | we need to pass in the relevant VAR_DECL if we want to do the | |
5275 | evaluation in a single pass. The evaluation will dynamically | |
5276 | update ctx.values for the VAR_DECL. We use the same strategy | |
5277 | for C++11 constexpr constructors that refer to the object being | |
5278 | initialized. */ | |
5279 | ctx.ctor = build_constructor (type, NULL); | |
165d0d5b | 5280 | CONSTRUCTOR_NO_CLEARING (ctx.ctor) = true; |
9c96033c | 5281 | if (!object) |
5282 | { | |
5283 | if (TREE_CODE (t) == TARGET_EXPR) | |
5284 | object = TARGET_EXPR_SLOT (t); | |
5285 | else if (TREE_CODE (t) == AGGR_INIT_EXPR) | |
5286 | object = AGGR_INIT_EXPR_SLOT (t); | |
5287 | } | |
cf72f34d | 5288 | ctx.object = object; |
5289 | if (object) | |
5290 | gcc_assert (same_type_ignoring_top_level_qualifiers_p | |
5291 | (type, TREE_TYPE (object))); | |
5292 | if (object && DECL_P (object)) | |
5293 | map.put (object, ctx.ctor); | |
5294 | if (TREE_CODE (r) == TARGET_EXPR) | |
5295 | /* Avoid creating another CONSTRUCTOR when we expand the | |
5296 | TARGET_EXPR. */ | |
5297 | r = TARGET_EXPR_INITIAL (r); | |
5298 | } | |
5299 | ||
6e1bbaae | 5300 | instantiate_constexpr_fns (r); |
f83e6885 | 5301 | r = cxx_eval_constant_expression (&ctx, r, |
b2a43197 | 5302 | false, &non_constant_p, &overflow_p); |
09b42213 | 5303 | |
5304 | verify_constant (r, allow_non_constant, &non_constant_p, &overflow_p); | |
5305 | ||
bbcc9042 | 5306 | /* Mutable logic is a bit tricky: we want to allow initialization of |
5307 | constexpr variables with mutable members, but we can't copy those | |
5308 | members to another constexpr variable. */ | |
5309 | if (TREE_CODE (r) == CONSTRUCTOR | |
5310 | && CONSTRUCTOR_MUTABLE_POISON (r)) | |
09b42213 | 5311 | { |
09b42213 | 5312 | if (!allow_non_constant) |
bbcc9042 | 5313 | error ("%qE is not a constant expression because it refers to " |
5314 | "mutable subobjects of %qT", t, type); | |
09b42213 | 5315 | non_constant_p = true; |
5316 | } | |
5317 | ||
c6d97004 | 5318 | if (TREE_CODE (r) == CONSTRUCTOR |
165d0d5b | 5319 | && CONSTRUCTOR_NO_CLEARING (r)) |
c6d97004 | 5320 | { |
5321 | if (!allow_non_constant) | |
5322 | error ("%qE is not a constant expression because it refers to " | |
5323 | "an incompletely initialized variable", t); | |
5324 | TREE_CONSTANT (r) = false; | |
5325 | non_constant_p = true; | |
5326 | } | |
5327 | ||
09b42213 | 5328 | /* Technically we should check this for all subexpressions, but that |
5329 | runs into problems with our internal representation of pointer | |
5330 | subtraction and the 5.19 rules are still in flux. */ | |
5331 | if (CONVERT_EXPR_CODE_P (TREE_CODE (r)) | |
5332 | && ARITHMETIC_TYPE_P (TREE_TYPE (r)) | |
5333 | && TREE_CODE (TREE_OPERAND (r, 0)) == ADDR_EXPR) | |
5334 | { | |
5335 | if (!allow_non_constant) | |
5336 | error ("conversion from pointer type %qT " | |
ea034e2c | 5337 | "to arithmetic type %qT in a constant expression", |
09b42213 | 5338 | TREE_TYPE (TREE_OPERAND (r, 0)), TREE_TYPE (r)); |
5339 | non_constant_p = true; | |
5340 | } | |
5341 | ||
5342 | if (!non_constant_p && overflow_p) | |
5343 | non_constant_p = true; | |
5344 | ||
c6c0523b | 5345 | /* Unshare the result unless it's a CONSTRUCTOR in which case it's already |
5346 | unshared. */ | |
5347 | bool should_unshare = true; | |
5348 | if (r == t || TREE_CODE (r) == CONSTRUCTOR) | |
5349 | should_unshare = false; | |
5350 | ||
09b42213 | 5351 | if (non_constant_p && !allow_non_constant) |
5352 | return error_mark_node; | |
5353 | else if (non_constant_p && TREE_CONSTANT (r)) | |
5354 | { | |
18d371d3 | 5355 | /* If __builtin_is_constant_evaluated () was evaluated to true |
5356 | and the result is not a valid constant expression, we need to | |
5357 | punt. */ | |
1562c831 | 5358 | if (manifestly_const_eval) |
18d371d3 | 5359 | return cxx_eval_outermost_constant_expr (t, true, strict, |
5360 | false, object); | |
1d29f4ea | 5361 | /* This isn't actually constant, so unset TREE_CONSTANT. |
5362 | Don't clear TREE_CONSTANT on ADDR_EXPR, as the middle-end requires | |
5363 | it to be set if it is invariant address, even when it is not | |
5364 | a valid C++ constant expression. Wrap it with a NOP_EXPR | |
5365 | instead. */ | |
5366 | if (EXPR_P (r) && TREE_CODE (r) != ADDR_EXPR) | |
09b42213 | 5367 | r = copy_node (r); |
5368 | else if (TREE_CODE (r) == CONSTRUCTOR) | |
5369 | r = build1 (VIEW_CONVERT_EXPR, TREE_TYPE (r), r); | |
5370 | else | |
5371 | r = build_nop (TREE_TYPE (r), r); | |
5372 | TREE_CONSTANT (r) = false; | |
5373 | } | |
59183fff | 5374 | else if (non_constant_p) |
09b42213 | 5375 | return t; |
5376 | ||
c6c0523b | 5377 | if (should_unshare) |
5378 | r = unshare_expr (r); | |
5379 | ||
09b42213 | 5380 | if (TREE_CODE (r) == CONSTRUCTOR && CLASS_TYPE_P (TREE_TYPE (r))) |
5381 | { | |
59183fff | 5382 | r = adjust_temp_type (type, r); |
09b42213 | 5383 | if (TREE_CODE (t) == TARGET_EXPR |
5384 | && TARGET_EXPR_INITIAL (t) == r) | |
5385 | return t; | |
59183fff | 5386 | else if (TREE_CODE (t) != CONSTRUCTOR) |
09b42213 | 5387 | { |
5388 | r = get_target_expr (r); | |
5389 | TREE_CONSTANT (r) = true; | |
09b42213 | 5390 | } |
5391 | } | |
59183fff | 5392 | |
5393 | return r; | |
09b42213 | 5394 | } |
5395 | ||
5396 | /* Returns true if T is a valid subexpression of a constant expression, | |
5397 | even if it isn't itself a constant expression. */ | |
5398 | ||
5399 | bool | |
5400 | is_sub_constant_expr (tree t) | |
5401 | { | |
5402 | bool non_constant_p = false; | |
5403 | bool overflow_p = false; | |
cf72f34d | 5404 | hash_map <tree, tree> map; |
84f13b2f | 5405 | HOST_WIDE_INT constexpr_ops_count = 0; |
2631cb67 | 5406 | |
18d371d3 | 5407 | constexpr_ctx ctx |
84f13b2f | 5408 | = { NULL, &map, NULL, NULL, NULL, NULL, &constexpr_ops_count, |
5409 | true, true, false }; | |
2631cb67 | 5410 | |
6e1bbaae | 5411 | instantiate_constexpr_fns (t); |
f83e6885 | 5412 | cxx_eval_constant_expression (&ctx, t, false, &non_constant_p, |
b2a43197 | 5413 | &overflow_p); |
09b42213 | 5414 | return !non_constant_p && !overflow_p; |
5415 | } | |
5416 | ||
5417 | /* If T represents a constant expression returns its reduced value. | |
5418 | Otherwise return error_mark_node. If T is dependent, then | |
5419 | return NULL. */ | |
5420 | ||
5421 | tree | |
cf72f34d | 5422 | cxx_constant_value (tree t, tree decl) |
09b42213 | 5423 | { |
18d371d3 | 5424 | return cxx_eval_outermost_constant_expr (t, false, true, true, decl); |
09b42213 | 5425 | } |
5426 | ||
d2c63826 | 5427 | /* Helper routine for fold_simple function. Either return simplified |
5428 | expression T, otherwise NULL_TREE. | |
5429 | In contrast to cp_fully_fold, and to maybe_constant_value, we try to fold | |
5430 | even if we are within template-declaration. So be careful on call, as in | |
5431 | such case types can be undefined. */ | |
5432 | ||
5433 | static tree | |
5434 | fold_simple_1 (tree t) | |
5435 | { | |
5436 | tree op1; | |
5437 | enum tree_code code = TREE_CODE (t); | |
5438 | ||
5439 | switch (code) | |
5440 | { | |
5441 | case INTEGER_CST: | |
5442 | case REAL_CST: | |
5443 | case VECTOR_CST: | |
5444 | case FIXED_CST: | |
5445 | case COMPLEX_CST: | |
5446 | return t; | |
5447 | ||
5448 | case SIZEOF_EXPR: | |
5449 | return fold_sizeof_expr (t); | |
5450 | ||
5451 | case ABS_EXPR: | |
19b4138e | 5452 | case ABSU_EXPR: |
d2c63826 | 5453 | case CONJ_EXPR: |
5454 | case REALPART_EXPR: | |
5455 | case IMAGPART_EXPR: | |
5456 | case NEGATE_EXPR: | |
5457 | case BIT_NOT_EXPR: | |
5458 | case TRUTH_NOT_EXPR: | |
5459 | case NOP_EXPR: | |
5460 | case VIEW_CONVERT_EXPR: | |
5461 | case CONVERT_EXPR: | |
5462 | case FLOAT_EXPR: | |
5463 | case FIX_TRUNC_EXPR: | |
5464 | case FIXED_CONVERT_EXPR: | |
5465 | case ADDR_SPACE_CONVERT_EXPR: | |
5466 | ||
5467 | op1 = TREE_OPERAND (t, 0); | |
5468 | ||
5469 | t = const_unop (code, TREE_TYPE (t), op1); | |
5470 | if (!t) | |
5471 | return NULL_TREE; | |
5472 | ||
5473 | if (CONVERT_EXPR_CODE_P (code) | |
5474 | && TREE_OVERFLOW_P (t) && !TREE_OVERFLOW_P (op1)) | |
5475 | TREE_OVERFLOW (t) = false; | |
5476 | return t; | |
5477 | ||
5478 | default: | |
5479 | return NULL_TREE; | |
5480 | } | |
5481 | } | |
5482 | ||
5483 | /* If T is a simple constant expression, returns its simplified value. | |
6fe5fea9 | 5484 | Otherwise returns T. In contrast to maybe_constant_value we |
d2c63826 | 5485 | simplify only few operations on constant-expressions, and we don't |
5486 | try to simplify constexpressions. */ | |
5487 | ||
5488 | tree | |
5489 | fold_simple (tree t) | |
5490 | { | |
d2c63826 | 5491 | if (processing_template_decl) |
5492 | return t; | |
5493 | ||
6fe5fea9 | 5494 | tree r = fold_simple_1 (t); |
5495 | if (r) | |
5496 | return r; | |
d2c63826 | 5497 | |
6fe5fea9 | 5498 | return t; |
d2c63826 | 5499 | } |
5500 | ||
09b42213 | 5501 | /* If T is a constant expression, returns its reduced value. |
5502 | Otherwise, if T does not have TREE_CONSTANT set, returns T. | |
1562c831 | 5503 | Otherwise, returns a version of T without TREE_CONSTANT. |
5504 | MANIFESTLY_CONST_EVAL is true if T is manifestly const-evaluated | |
5505 | as per P0595. */ | |
09b42213 | 5506 | |
b601ad30 | 5507 | static GTY((deletable)) hash_map<tree, tree> *cv_cache; |
5508 | ||
5509 | tree | |
1562c831 | 5510 | maybe_constant_value (tree t, tree decl, bool manifestly_const_eval) |
09b42213 | 5511 | { |
5512 | tree r; | |
5513 | ||
7e1f8be4 | 5514 | if (!is_nondependent_constant_expression (t)) |
09b42213 | 5515 | { |
5516 | if (TREE_OVERFLOW_P (t)) | |
5517 | { | |
5518 | t = build_nop (TREE_TYPE (t), t); | |
5519 | TREE_CONSTANT (t) = false; | |
5520 | } | |
5521 | return t; | |
5522 | } | |
b601ad30 | 5523 | else if (CONSTANT_CLASS_P (t)) |
5524 | /* No caching or evaluation needed. */ | |
5525 | return t; | |
5526 | ||
1562c831 | 5527 | if (manifestly_const_eval) |
5528 | return cxx_eval_outermost_constant_expr (t, true, true, true, decl); | |
5529 | ||
b601ad30 | 5530 | if (cv_cache == NULL) |
5531 | cv_cache = hash_map<tree, tree>::create_ggc (101); | |
5532 | if (tree *cached = cv_cache->get (t)) | |
5533 | return *cached; | |
09b42213 | 5534 | |
18d371d3 | 5535 | r = cxx_eval_outermost_constant_expr (t, true, true, false, decl); |
5e8689fb | 5536 | gcc_checking_assert (r == t |
5537 | || CONVERT_EXPR_P (t) | |
5538 | || TREE_CODE (t) == VIEW_CONVERT_EXPR | |
5539 | || (TREE_CONSTANT (t) && !TREE_CONSTANT (r)) | |
5540 | || !cp_tree_equal (r, t)); | |
b601ad30 | 5541 | cv_cache->put (t, r); |
09b42213 | 5542 | return r; |
5543 | } | |
5544 | ||
2a655a4c | 5545 | /* Dispose of the whole CV_CACHE. */ |
5546 | ||
5547 | static void | |
5548 | clear_cv_cache (void) | |
5549 | { | |
5550 | if (cv_cache != NULL) | |
5551 | cv_cache->empty (); | |
5552 | } | |
5553 | ||
f553d9f8 | 5554 | /* Dispose of the whole CV_CACHE and FOLD_CACHE. */ |
a0c919f7 | 5555 | |
5556 | void | |
f553d9f8 | 5557 | clear_cv_and_fold_caches (void) |
a0c919f7 | 5558 | { |
2a655a4c | 5559 | clear_cv_cache (); |
f553d9f8 | 5560 | clear_fold_cache (); |
a0c919f7 | 5561 | } |
5562 | ||
21131a05 | 5563 | /* Like maybe_constant_value but first fully instantiate the argument. |
5564 | ||
5565 | Note: this is equivalent to instantiate_non_dependent_expr_sfinae | |
006b503a | 5566 | (t, complain) followed by maybe_constant_value but is more efficient, |
5567 | because it calls instantiation_dependent_expression_p and | |
5568 | potential_constant_expression at most once. | |
4749c4ac | 5569 | The manifestly_const_eval argument is passed to maybe_constant_value. |
006b503a | 5570 | |
5571 | Callers should generally pass their active complain, or if they are in a | |
5572 | non-template, diagnosing context, they can use the default of | |
5573 | tf_warning_or_error. Callers that might be within a template context, don't | |
5574 | have a complain parameter, and aren't going to remember the result for long | |
5575 | (e.g. null_ptr_cst_p), can pass tf_none and deal with error_mark_node | |
5576 | appropriately. */ | |
21131a05 | 5577 | |
5578 | tree | |
006b503a | 5579 | fold_non_dependent_expr (tree t, |
4749c4ac | 5580 | tsubst_flags_t complain /* = tf_warning_or_error */, |
5581 | bool manifestly_const_eval /* = false */) | |
21131a05 | 5582 | { |
5583 | if (t == NULL_TREE) | |
5584 | return NULL_TREE; | |
5585 | ||
5586 | /* If we're in a template, but T isn't value dependent, simplify | |
5587 | it. We're supposed to treat: | |
5588 | ||
5589 | template <typename T> void f(T[1 + 1]); | |
5590 | template <typename T> void f(T[2]); | |
5591 | ||
5592 | as two declarations of the same function, for example. */ | |
5593 | if (processing_template_decl) | |
5594 | { | |
7e1f8be4 | 5595 | if (is_nondependent_constant_expression (t)) |
21131a05 | 5596 | { |
c8a9f04c | 5597 | processing_template_decl_sentinel s; |
006b503a | 5598 | t = instantiate_non_dependent_expr_internal (t, complain); |
21131a05 | 5599 | |
5600 | if (type_unknown_p (t) | |
5601 | || BRACE_ENCLOSED_INITIALIZER_P (t)) | |
5602 | { | |
5603 | if (TREE_OVERFLOW_P (t)) | |
5604 | { | |
5605 | t = build_nop (TREE_TYPE (t), t); | |
5606 | TREE_CONSTANT (t) = false; | |
5607 | } | |
5608 | return t; | |
5609 | } | |
5610 | ||
4749c4ac | 5611 | tree r = cxx_eval_outermost_constant_expr (t, true, true, |
5612 | manifestly_const_eval, | |
18d371d3 | 5613 | NULL_TREE); |
21131a05 | 5614 | /* cp_tree_equal looks through NOPs, so allow them. */ |
5e8689fb | 5615 | gcc_checking_assert (r == t |
5616 | || CONVERT_EXPR_P (t) | |
5617 | || TREE_CODE (t) == VIEW_CONVERT_EXPR | |
5618 | || (TREE_CONSTANT (t) && !TREE_CONSTANT (r)) | |
5619 | || !cp_tree_equal (r, t)); | |
21131a05 | 5620 | return r; |
5621 | } | |
5622 | else if (TREE_OVERFLOW_P (t)) | |
5623 | { | |
5624 | t = build_nop (TREE_TYPE (t), t); | |
5625 | TREE_CONSTANT (t) = false; | |
5626 | } | |
5627 | return t; | |
5628 | } | |
5629 | ||
4749c4ac | 5630 | return maybe_constant_value (t, NULL_TREE, manifestly_const_eval); |
21131a05 | 5631 | } |
5632 | ||
09b42213 | 5633 | /* Like maybe_constant_value, but returns a CONSTRUCTOR directly, rather |
18d371d3 | 5634 | than wrapped in a TARGET_EXPR. |
5635 | ALLOW_NON_CONSTANT is false if T is required to be a constant expression. | |
1562c831 | 5636 | MANIFESTLY_CONST_EVAL is true if T is manifestly const-evaluated as |
18d371d3 | 5637 | per P0595 even when ALLOW_NON_CONSTANT is true. */ |
09b42213 | 5638 | |
0c703e14 | 5639 | static tree |
18d371d3 | 5640 | maybe_constant_init_1 (tree t, tree decl, bool allow_non_constant, |
1562c831 | 5641 | bool manifestly_const_eval) |
09b42213 | 5642 | { |
d2c63826 | 5643 | if (!t) |
5644 | return t; | |
09b42213 | 5645 | if (TREE_CODE (t) == EXPR_STMT) |
5646 | t = TREE_OPERAND (t, 0); | |
5647 | if (TREE_CODE (t) == CONVERT_EXPR | |
5648 | && VOID_TYPE_P (TREE_TYPE (t))) | |
5649 | t = TREE_OPERAND (t, 0); | |
9c96033c | 5650 | if (TREE_CODE (t) == INIT_EXPR) |
5651 | t = TREE_OPERAND (t, 1); | |
c6d97004 | 5652 | if (TREE_CODE (t) == TARGET_EXPR) |
5653 | t = TARGET_EXPR_INITIAL (t); | |
7e1f8be4 | 5654 | if (!is_nondependent_static_init_expression (t)) |
2055d27a | 5655 | /* Don't try to evaluate it. */; |
0c703e14 | 5656 | else if (CONSTANT_CLASS_P (t) && allow_non_constant) |
b601ad30 | 5657 | /* No evaluation needed. */; |
2055d27a | 5658 | else |
18d371d3 | 5659 | t = cxx_eval_outermost_constant_expr (t, allow_non_constant, |
fbe79a84 | 5660 | /*strict*/false, |
1562c831 | 5661 | manifestly_const_eval, decl); |
09b42213 | 5662 | if (TREE_CODE (t) == TARGET_EXPR) |
5663 | { | |
5664 | tree init = TARGET_EXPR_INITIAL (t); | |
5665 | if (TREE_CODE (init) == CONSTRUCTOR) | |
5666 | t = init; | |
5667 | } | |
5668 | return t; | |
5669 | } | |
5670 | ||
0c703e14 | 5671 | /* Wrapper for maybe_constant_init_1 which permits non constants. */ |
5672 | ||
5673 | tree | |
1562c831 | 5674 | maybe_constant_init (tree t, tree decl, bool manifestly_const_eval) |
0c703e14 | 5675 | { |
1562c831 | 5676 | return maybe_constant_init_1 (t, decl, true, manifestly_const_eval); |
0c703e14 | 5677 | } |
5678 | ||
5679 | /* Wrapper for maybe_constant_init_1 which does not permit non constants. */ | |
5680 | ||
5681 | tree | |
5682 | cxx_constant_init (tree t, tree decl) | |
5683 | { | |
18d371d3 | 5684 | return maybe_constant_init_1 (t, decl, false, true); |
0c703e14 | 5685 | } |
5686 | ||
09b42213 | 5687 | #if 0 |
5688 | /* FIXME see ADDR_EXPR section in potential_constant_expression_1. */ | |
5689 | /* Return true if the object referred to by REF has automatic or thread | |
5690 | local storage. */ | |
5691 | ||
5692 | enum { ck_ok, ck_bad, ck_unknown }; | |
5693 | static int | |
5694 | check_automatic_or_tls (tree ref) | |
5695 | { | |
3754d046 | 5696 | machine_mode mode; |
81bc0f0f | 5697 | poly_int64 bitsize, bitpos; |
09b42213 | 5698 | tree offset; |
5699 | int volatilep = 0, unsignedp = 0; | |
5700 | tree decl = get_inner_reference (ref, &bitsize, &bitpos, &offset, | |
5701 | &mode, &unsignedp, &volatilep, false); | |
5702 | duration_kind dk; | |
5703 | ||
5704 | /* If there isn't a decl in the middle, we don't know the linkage here, | |
5705 | and this isn't a constant expression anyway. */ | |
5706 | if (!DECL_P (decl)) | |
5707 | return ck_unknown; | |
5708 | dk = decl_storage_duration (decl); | |
5709 | return (dk == dk_auto || dk == dk_thread) ? ck_bad : ck_ok; | |
5710 | } | |
5711 | #endif | |
5712 | ||
5713 | /* Return true if T denotes a potentially constant expression. Issue | |
5714 | diagnostic as appropriate under control of FLAGS. If WANT_RVAL is true, | |
7e1f8be4 | 5715 | an lvalue-rvalue conversion is implied. If NOW is true, we want to |
5716 | consider the expression in the current context, independent of constexpr | |
5717 | substitution. | |
09b42213 | 5718 | |
5719 | C++0x [expr.const] used to say | |
5720 | ||
5721 | 6 An expression is a potential constant expression if it is | |
5722 | a constant expression where all occurrences of function | |
5723 | parameters are replaced by arbitrary constant expressions | |
5724 | of the appropriate type. | |
5725 | ||
5726 | 2 A conditional expression is a constant expression unless it | |
5727 | involves one of the following as a potentially evaluated | |
5728 | subexpression (3.2), but subexpressions of logical AND (5.14), | |
5729 | logical OR (5.15), and conditional (5.16) operations that are | |
5730 | not evaluated are not considered. */ | |
5731 | ||
5732 | static bool | |
7e1f8be4 | 5733 | potential_constant_expression_1 (tree t, bool want_rval, bool strict, bool now, |
32fee334 | 5734 | tsubst_flags_t flags, tree *jump_target) |
09b42213 | 5735 | { |
7e1f8be4 | 5736 | #define RECUR(T,RV) \ |
32fee334 | 5737 | potential_constant_expression_1 ((T), (RV), strict, now, flags, jump_target) |
7e1f8be4 | 5738 | |
09b42213 | 5739 | enum { any = false, rval = true }; |
5740 | int i; | |
5741 | tree tmp; | |
5742 | ||
5743 | if (t == error_mark_node) | |
5744 | return false; | |
5745 | if (t == NULL_TREE) | |
5746 | return true; | |
d3a3cfb8 | 5747 | location_t loc = cp_expr_loc_or_loc (t, input_location); |
32fee334 | 5748 | |
5749 | if (*jump_target) | |
5750 | /* If we are jumping, ignore everything. This is simpler than the | |
5751 | cxx_eval_constant_expression handling because we only need to be | |
5752 | conservatively correct, and we don't necessarily have a constant value | |
5753 | available, so we don't bother with switch tracking. */ | |
5754 | return true; | |
5755 | ||
04ced4a2 | 5756 | if (TREE_THIS_VOLATILE (t) && want_rval) |
09b42213 | 5757 | { |
5758 | if (flags & tf_error) | |
04ced4a2 | 5759 | error_at (loc, "lvalue-to-rvalue conversion of a volatile lvalue " |
5760 | "%qE with type %qT", t, TREE_TYPE (t)); | |
09b42213 | 5761 | return false; |
5762 | } | |
5763 | if (CONSTANT_CLASS_P (t)) | |
5764 | return true; | |
c7282bf2 | 5765 | if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_TYPED) |
5766 | && TREE_TYPE (t) == error_mark_node) | |
5767 | return false; | |
09b42213 | 5768 | |
5769 | switch (TREE_CODE (t)) | |
5770 | { | |
5771 | case FUNCTION_DECL: | |
5772 | case BASELINK: | |
5773 | case TEMPLATE_DECL: | |
5774 | case OVERLOAD: | |
5775 | case TEMPLATE_ID_EXPR: | |
5776 | case LABEL_DECL: | |
5777 | case LABEL_EXPR: | |
9c96033c | 5778 | case CASE_LABEL_EXPR: |
09b42213 | 5779 | case CONST_DECL: |
5780 | case SIZEOF_EXPR: | |
5781 | case ALIGNOF_EXPR: | |
5782 | case OFFSETOF_EXPR: | |
5783 | case NOEXCEPT_EXPR: | |
5784 | case TEMPLATE_PARM_INDEX: | |
5785 | case TRAIT_EXPR: | |
5786 | case IDENTIFIER_NODE: | |
5787 | case USERDEF_LITERAL: | |
5788 | /* We can see a FIELD_DECL in a pointer-to-member expression. */ | |
5789 | case FIELD_DECL: | |
d2c63826 | 5790 | case RESULT_DECL: |
09b42213 | 5791 | case USING_DECL: |
9c96033c | 5792 | case USING_STMT: |
cf72f34d | 5793 | case PLACEHOLDER_EXPR: |
56c12fd4 | 5794 | case REQUIRES_EXPR: |
33603066 | 5795 | case STATIC_ASSERT: |
90567983 | 5796 | case DEBUG_BEGIN_STMT: |
09b42213 | 5797 | return true; |
5798 | ||
32fee334 | 5799 | case RETURN_EXPR: |
5800 | if (!RECUR (TREE_OPERAND (t, 0), any)) | |
5801 | return false; | |
5802 | /* FALLTHROUGH */ | |
5803 | ||
5804 | case BREAK_STMT: | |
5805 | case CONTINUE_STMT: | |
5806 | *jump_target = t; | |
5807 | return true; | |
5808 | ||
7e1f8be4 | 5809 | case PARM_DECL: |
5810 | if (now) | |
5811 | { | |
5812 | if (flags & tf_error) | |
5813 | error ("%qE is not a constant expression", t); | |
5814 | return false; | |
5815 | } | |
5816 | return true; | |
5817 | ||
09b42213 | 5818 | case AGGR_INIT_EXPR: |
5819 | case CALL_EXPR: | |
5820 | /* -- an invocation of a function other than a constexpr function | |
5821 | or a constexpr constructor. */ | |
5822 | { | |
5823 | tree fun = get_function_named_in_call (t); | |
5824 | const int nargs = call_expr_nargs (t); | |
5825 | i = 0; | |
5826 | ||
9c96033c | 5827 | if (fun == NULL_TREE) |
5828 | { | |
732905bb | 5829 | /* Reset to allow the function to continue past the end |
5830 | of the block below. Otherwise return early. */ | |
5831 | bool bail = true; | |
5832 | ||
32cf7025 | 5833 | if (TREE_CODE (t) == CALL_EXPR |
5834 | && CALL_EXPR_FN (t) == NULL_TREE) | |
5835 | switch (CALL_EXPR_IFN (t)) | |
5836 | { | |
5837 | /* These should be ignored, they are optimized away from | |
5838 | constexpr functions. */ | |
5839 | case IFN_UBSAN_NULL: | |
5840 | case IFN_UBSAN_BOUNDS: | |
5841 | case IFN_UBSAN_VPTR: | |
3c77f69c | 5842 | case IFN_FALLTHROUGH: |
32cf7025 | 5843 | return true; |
732905bb | 5844 | |
5845 | case IFN_ADD_OVERFLOW: | |
5846 | case IFN_SUB_OVERFLOW: | |
5847 | case IFN_MUL_OVERFLOW: | |
6e1b2ffb | 5848 | case IFN_LAUNDER: |
59409f09 | 5849 | case IFN_VEC_CONVERT: |
732905bb | 5850 | bail = false; |
59409f09 | 5851 | break; |
732905bb | 5852 | |
32cf7025 | 5853 | default: |
5854 | break; | |
5855 | } | |
732905bb | 5856 | |
5857 | if (bail) | |
5858 | { | |
5859 | /* fold_call_expr can't do anything with IFN calls. */ | |
5860 | if (flags & tf_error) | |
d6a08f5c | 5861 | error_at (loc, "call to internal function %qE", t); |
732905bb | 5862 | return false; |
5863 | } | |
9c96033c | 5864 | } |
732905bb | 5865 | |
5866 | if (fun && is_overloaded_fn (fun)) | |
09b42213 | 5867 | { |
5868 | if (TREE_CODE (fun) == FUNCTION_DECL) | |
5869 | { | |
5870 | if (builtin_valid_in_constant_expr_p (fun)) | |
5871 | return true; | |
5872 | if (!DECL_DECLARED_CONSTEXPR_P (fun) | |
5873 | /* Allow any built-in function; if the expansion | |
5874 | isn't constant, we'll deal with that then. */ | |
a0e9bfbb | 5875 | && !fndecl_built_in_p (fun)) |
09b42213 | 5876 | { |
5877 | if (flags & tf_error) | |
5878 | { | |
5967b28b | 5879 | error_at (loc, "call to non-%<constexpr%> function %qD", |
d6a08f5c | 5880 | fun); |
09b42213 | 5881 | explain_invalid_constexpr_fn (fun); |
5882 | } | |
5883 | return false; | |
5884 | } | |
5885 | /* A call to a non-static member function takes the address | |
5886 | of the object as the first argument. But in a constant | |
5887 | expression the address will be folded away, so look | |
5888 | through it now. */ | |
5889 | if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fun) | |
5890 | && !DECL_CONSTRUCTOR_P (fun)) | |
5891 | { | |
5892 | tree x = get_nth_callarg (t, 0); | |
5893 | if (is_this_parameter (x)) | |
cf72f34d | 5894 | return true; |
7e1f8be4 | 5895 | /* Don't require an immediately constant value, as |
5896 | constexpr substitution might not use the value. */ | |
5897 | bool sub_now = false; | |
5898 | if (!potential_constant_expression_1 (x, rval, strict, | |
32fee334 | 5899 | sub_now, flags, |
5900 | jump_target)) | |
09b42213 | 5901 | return false; |
5902 | i = 1; | |
5903 | } | |
5904 | } | |
5905 | else | |
5906 | { | |
2055d27a | 5907 | if (!RECUR (fun, true)) |
09b42213 | 5908 | return false; |
5909 | fun = get_first_fn (fun); | |
5910 | } | |
5911 | /* Skip initial arguments to base constructors. */ | |
5912 | if (DECL_BASE_CONSTRUCTOR_P (fun)) | |
5913 | i = num_artificial_parms_for (fun); | |
5914 | fun = DECL_ORIGIN (fun); | |
5915 | } | |
732905bb | 5916 | else if (fun) |
09b42213 | 5917 | { |
2055d27a | 5918 | if (RECUR (fun, rval)) |
09b42213 | 5919 | /* Might end up being a constant function pointer. */; |
5920 | else | |
5921 | return false; | |
5922 | } | |
5923 | for (; i < nargs; ++i) | |
5924 | { | |
5925 | tree x = get_nth_callarg (t, i); | |
b2742b58 | 5926 | /* In a template, reference arguments haven't been converted to |
5927 | REFERENCE_TYPE and we might not even know if the parameter | |
5928 | is a reference, so accept lvalue constants too. */ | |
5929 | bool rv = processing_template_decl ? any : rval; | |
7e1f8be4 | 5930 | /* Don't require an immediately constant value, as constexpr |
5931 | substitution might not use the value of the argument. */ | |
5932 | bool sub_now = false; | |
5933 | if (!potential_constant_expression_1 (x, rv, strict, | |
32fee334 | 5934 | sub_now, flags, jump_target)) |
09b42213 | 5935 | return false; |
5936 | } | |
5937 | return true; | |
5938 | } | |
5939 | ||
5940 | case NON_LVALUE_EXPR: | |
5941 | /* -- an lvalue-to-rvalue conversion (4.1) unless it is applied to | |
5942 | -- an lvalue of integral type that refers to a non-volatile | |
5943 | const variable or static data member initialized with | |
5944 | constant expressions, or | |
5945 | ||
5946 | -- an lvalue of literal type that refers to non-volatile | |
5947 | object defined with constexpr, or that refers to a | |
5948 | sub-object of such an object; */ | |
2055d27a | 5949 | return RECUR (TREE_OPERAND (t, 0), rval); |
09b42213 | 5950 | |
5951 | case VAR_DECL: | |
9c8aeb66 | 5952 | if (DECL_HAS_VALUE_EXPR_P (t)) |
297de7bc | 5953 | { |
d0e2b7e7 | 5954 | if (now && is_normal_capture_proxy (t)) |
297de7bc | 5955 | { |
5956 | /* -- in a lambda-expression, a reference to this or to a | |
5957 | variable with automatic storage duration defined outside that | |
5958 | lambda-expression, where the reference would be an | |
5959 | odr-use. */ | |
5960 | if (flags & tf_error) | |
5961 | { | |
5962 | tree cap = DECL_CAPTURED_VARIABLE (t); | |
5963 | error ("lambda capture of %qE is not a constant expression", | |
5964 | cap); | |
5965 | if (!want_rval && decl_constant_var_p (cap)) | |
5966 | inform (input_location, "because it is used as a glvalue"); | |
5967 | } | |
5968 | return false; | |
5969 | } | |
5970 | return RECUR (DECL_VALUE_EXPR (t), rval); | |
5971 | } | |
2055d27a | 5972 | if (want_rval |
33603066 | 5973 | && !var_in_maybe_constexpr_fn (t) |
c7282bf2 | 5974 | && !type_dependent_expression_p (t) |
8d6486e1 | 5975 | && !decl_maybe_constant_var_p (t) |
2055d27a | 5976 | && (strict |
5977 | || !CP_TYPE_CONST_NON_VOLATILE_P (TREE_TYPE (t)) | |
8d6486e1 | 5978 | || (DECL_INITIAL (t) |
5979 | && !DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (t))) | |
c7282bf2 | 5980 | && COMPLETE_TYPE_P (TREE_TYPE (t)) |
cd5a9ed1 | 5981 | && !is_really_empty_class (TREE_TYPE (t), /*ignore_vptr*/false)) |
09b42213 | 5982 | { |
5983 | if (flags & tf_error) | |
5984 | non_const_var_error (t); | |
5985 | return false; | |
5986 | } | |
5987 | return true; | |
5988 | ||
5989 | case NOP_EXPR: | |
92651efb | 5990 | if (REINTERPRET_CAST_P (t)) |
5991 | { | |
5992 | if (flags & tf_error) | |
5993 | error_at (loc, "a reinterpret_cast is not a constant expression"); | |
5994 | return false; | |
5995 | } | |
5996 | /* FALLTHRU */ | |
09b42213 | 5997 | case CONVERT_EXPR: |
5998 | case VIEW_CONVERT_EXPR: | |
5999 | /* -- a reinterpret_cast. FIXME not implemented, and this rule | |
6000 | may change to something more specific to type-punning (DR 1312). */ | |
6001 | { | |
6002 | tree from = TREE_OPERAND (t, 0); | |
d582d140 | 6003 | if (location_wrapper_p (t)) |
6004 | return (RECUR (from, want_rval)); | |
6005 | if (INDIRECT_TYPE_P (TREE_TYPE (t))) | |
09b42213 | 6006 | { |
d582d140 | 6007 | STRIP_ANY_LOCATION_WRAPPER (from); |
6008 | if (TREE_CODE (from) == INTEGER_CST | |
6009 | && !integer_zerop (from)) | |
6010 | { | |
6011 | if (flags & tf_error) | |
6012 | error_at (loc, "reinterpret_cast from integer to pointer"); | |
6013 | return false; | |
6014 | } | |
09b42213 | 6015 | } |
2055d27a | 6016 | return (RECUR (from, TREE_CODE (t) != VIEW_CONVERT_EXPR)); |
09b42213 | 6017 | } |
6018 | ||
cd45162d | 6019 | case ADDRESSOF_EXPR: |
6020 | /* This is like ADDR_EXPR, except it won't form pointer-to-member. */ | |
6021 | t = TREE_OPERAND (t, 0); | |
6022 | goto handle_addr_expr; | |
6023 | ||
09b42213 | 6024 | case ADDR_EXPR: |
6025 | /* -- a unary operator & that is applied to an lvalue that | |
6026 | designates an object with thread or automatic storage | |
6027 | duration; */ | |
6028 | t = TREE_OPERAND (t, 0); | |
6029 | ||
6030 | if (TREE_CODE (t) == OFFSET_REF && PTRMEM_OK_P (t)) | |
6031 | /* A pointer-to-member constant. */ | |
6032 | return true; | |
6033 | ||
cd45162d | 6034 | handle_addr_expr: |
09b42213 | 6035 | #if 0 |
6036 | /* FIXME adjust when issue 1197 is fully resolved. For now don't do | |
6037 | any checking here, as we might dereference the pointer later. If | |
6038 | we remove this code, also remove check_automatic_or_tls. */ | |
6039 | i = check_automatic_or_tls (t); | |
6040 | if (i == ck_ok) | |
6041 | return true; | |
6042 | if (i == ck_bad) | |
6043 | { | |
6044 | if (flags & tf_error) | |
6045 | error ("address-of an object %qE with thread local or " | |
6046 | "automatic storage is not a constant expression", t); | |
6047 | return false; | |
6048 | } | |
6049 | #endif | |
2055d27a | 6050 | return RECUR (t, any); |
09b42213 | 6051 | |
20b34a56 | 6052 | case REALPART_EXPR: |
6053 | case IMAGPART_EXPR: | |
09b42213 | 6054 | case COMPONENT_REF: |
6055 | case BIT_FIELD_REF: | |
6056 | case ARROW_EXPR: | |
6057 | case OFFSET_REF: | |
6058 | /* -- a class member access unless its postfix-expression is | |
6059 | of literal type or of pointer to literal type. */ | |
6060 | /* This test would be redundant, as it follows from the | |
6061 | postfix-expression being a potential constant expression. */ | |
eade0940 | 6062 | if (type_unknown_p (t)) |
6063 | return true; | |
2055d27a | 6064 | return RECUR (TREE_OPERAND (t, 0), want_rval); |
09b42213 | 6065 | |
6066 | case EXPR_PACK_EXPANSION: | |
2055d27a | 6067 | return RECUR (PACK_EXPANSION_PATTERN (t), want_rval); |
09b42213 | 6068 | |
6069 | case INDIRECT_REF: | |
6070 | { | |
6071 | tree x = TREE_OPERAND (t, 0); | |
6072 | STRIP_NOPS (x); | |
997bbf70 | 6073 | if (is_this_parameter (x) && !is_capture_proxy (x)) |
09b42213 | 6074 | { |
b7e4a558 | 6075 | if (!var_in_maybe_constexpr_fn (x)) |
09b42213 | 6076 | { |
6077 | if (flags & tf_error) | |
d6a08f5c | 6078 | error_at (loc, "use of %<this%> in a constant expression"); |
09b42213 | 6079 | return false; |
6080 | } | |
09b42213 | 6081 | return true; |
6082 | } | |
2055d27a | 6083 | return RECUR (x, rval); |
09b42213 | 6084 | } |
6085 | ||
9c96033c | 6086 | case STATEMENT_LIST: |
6087 | { | |
6088 | tree_stmt_iterator i; | |
6089 | for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i)) | |
6090 | { | |
2055d27a | 6091 | if (!RECUR (tsi_stmt (i), any)) |
9c96033c | 6092 | return false; |
6093 | } | |
6094 | return true; | |
6095 | } | |
6096 | break; | |
6097 | ||
6098 | case MODIFY_EXPR: | |
6099 | if (cxx_dialect < cxx14) | |
6100 | goto fail; | |
2055d27a | 6101 | if (!RECUR (TREE_OPERAND (t, 0), any)) |
9c96033c | 6102 | return false; |
2055d27a | 6103 | if (!RECUR (TREE_OPERAND (t, 1), rval)) |
9c96033c | 6104 | return false; |
6105 | return true; | |
6106 | ||
6107 | case MODOP_EXPR: | |
6108 | if (cxx_dialect < cxx14) | |
6109 | goto fail; | |
2055d27a | 6110 | if (!RECUR (TREE_OPERAND (t, 0), rval)) |
9c96033c | 6111 | return false; |
2055d27a | 6112 | if (!RECUR (TREE_OPERAND (t, 2), rval)) |
9c96033c | 6113 | return false; |
6114 | return true; | |
6115 | ||
9c96033c | 6116 | case DO_STMT: |
2055d27a | 6117 | if (!RECUR (DO_COND (t), rval)) |
9c96033c | 6118 | return false; |
2055d27a | 6119 | if (!RECUR (DO_BODY (t), any)) |
9c96033c | 6120 | return false; |
32fee334 | 6121 | if (breaks (jump_target) || continues (jump_target)) |
6122 | *jump_target = NULL_TREE; | |
9c96033c | 6123 | return true; |
6124 | ||
6125 | case FOR_STMT: | |
2055d27a | 6126 | if (!RECUR (FOR_INIT_STMT (t), any)) |
9c96033c | 6127 | return false; |
10811950 | 6128 | tmp = FOR_COND (t); |
6129 | if (!RECUR (tmp, rval)) | |
9c96033c | 6130 | return false; |
10811950 | 6131 | if (tmp) |
6132 | { | |
6133 | if (!processing_template_decl) | |
6134 | tmp = cxx_eval_outermost_constant_expr (tmp, true); | |
f807ff66 | 6135 | /* If we couldn't evaluate the condition, it might not ever be |
6136 | true. */ | |
6137 | if (!integer_onep (tmp)) | |
10811950 | 6138 | return true; |
6139 | } | |
2055d27a | 6140 | if (!RECUR (FOR_EXPR (t), any)) |
9c96033c | 6141 | return false; |
2055d27a | 6142 | if (!RECUR (FOR_BODY (t), any)) |
9c96033c | 6143 | return false; |
32fee334 | 6144 | if (breaks (jump_target) || continues (jump_target)) |
6145 | *jump_target = NULL_TREE; | |
9c96033c | 6146 | return true; |
6147 | ||
33603066 | 6148 | case RANGE_FOR_STMT: |
f4416678 | 6149 | if (!RECUR (RANGE_FOR_INIT_STMT (t), any)) |
6150 | return false; | |
33603066 | 6151 | if (!RECUR (RANGE_FOR_EXPR (t), any)) |
6152 | return false; | |
6153 | if (!RECUR (RANGE_FOR_BODY (t), any)) | |
6154 | return false; | |
32fee334 | 6155 | if (breaks (jump_target) || continues (jump_target)) |
6156 | *jump_target = NULL_TREE; | |
33603066 | 6157 | return true; |
6158 | ||
9c96033c | 6159 | case WHILE_STMT: |
10811950 | 6160 | tmp = WHILE_COND (t); |
6161 | if (!RECUR (tmp, rval)) | |
9c96033c | 6162 | return false; |
10811950 | 6163 | if (!processing_template_decl) |
6164 | tmp = cxx_eval_outermost_constant_expr (tmp, true); | |
f807ff66 | 6165 | /* If we couldn't evaluate the condition, it might not ever be true. */ |
6166 | if (!integer_onep (tmp)) | |
10811950 | 6167 | return true; |
2055d27a | 6168 | if (!RECUR (WHILE_BODY (t), any)) |
9c96033c | 6169 | return false; |
32fee334 | 6170 | if (breaks (jump_target) || continues (jump_target)) |
6171 | *jump_target = NULL_TREE; | |
9c96033c | 6172 | return true; |
6173 | ||
6174 | case SWITCH_STMT: | |
2055d27a | 6175 | if (!RECUR (SWITCH_STMT_COND (t), rval)) |
9c96033c | 6176 | return false; |
748c426a | 6177 | /* FIXME we don't check SWITCH_STMT_BODY currently, because even |
6178 | unreachable labels would be checked. */ | |
9c96033c | 6179 | return true; |
6180 | ||
da7981e0 | 6181 | case STMT_EXPR: |
2055d27a | 6182 | return RECUR (STMT_EXPR_STMT (t), rval); |
da7981e0 | 6183 | |
09b42213 | 6184 | case LAMBDA_EXPR: |
27db1f50 | 6185 | if (cxx_dialect >= cxx17) |
6186 | /* In C++17 lambdas can be constexpr, don't give up yet. */ | |
6187 | return true; | |
6188 | else if (flags & tf_error) | |
6189 | error_at (loc, "lambda-expression is not a constant expression " | |
6190 | "before C++17"); | |
6191 | return false; | |
6192 | ||
09b42213 | 6193 | case DYNAMIC_CAST_EXPR: |
6194 | case PSEUDO_DTOR_EXPR: | |
09b42213 | 6195 | case NEW_EXPR: |
6196 | case VEC_NEW_EXPR: | |
6197 | case DELETE_EXPR: | |
6198 | case VEC_DELETE_EXPR: | |
6199 | case THROW_EXPR: | |
d6a08f5c | 6200 | case OMP_PARALLEL: |
6201 | case OMP_TASK: | |
6202 | case OMP_FOR: | |
83728168 | 6203 | case OMP_SIMD: |
d6a08f5c | 6204 | case OMP_DISTRIBUTE: |
6205 | case OMP_TASKLOOP: | |
6206 | case OMP_TEAMS: | |
6207 | case OMP_TARGET_DATA: | |
6208 | case OMP_TARGET: | |
6209 | case OMP_SECTIONS: | |
6210 | case OMP_ORDERED: | |
6211 | case OMP_CRITICAL: | |
6212 | case OMP_SINGLE: | |
6213 | case OMP_SECTION: | |
6214 | case OMP_MASTER: | |
6215 | case OMP_TASKGROUP: | |
6216 | case OMP_TARGET_UPDATE: | |
6217 | case OMP_TARGET_ENTER_DATA: | |
6218 | case OMP_TARGET_EXIT_DATA: | |
09b42213 | 6219 | case OMP_ATOMIC: |
6220 | case OMP_ATOMIC_READ: | |
6221 | case OMP_ATOMIC_CAPTURE_OLD: | |
6222 | case OMP_ATOMIC_CAPTURE_NEW: | |
7e5a76c8 | 6223 | case OMP_DEPOBJ: |
d6a08f5c | 6224 | case OACC_PARALLEL: |
6225 | case OACC_KERNELS: | |
6226 | case OACC_DATA: | |
6227 | case OACC_HOST_DATA: | |
6228 | case OACC_LOOP: | |
6229 | case OACC_CACHE: | |
6230 | case OACC_DECLARE: | |
6231 | case OACC_ENTER_DATA: | |
6232 | case OACC_EXIT_DATA: | |
6233 | case OACC_UPDATE: | |
09b42213 | 6234 | /* GCC internal stuff. */ |
6235 | case VA_ARG_EXPR: | |
09b42213 | 6236 | case TRANSACTION_EXPR: |
9c96033c | 6237 | case ASM_EXPR: |
9abecca2 | 6238 | case AT_ENCODE_EXPR: |
9c96033c | 6239 | fail: |
09b42213 | 6240 | if (flags & tf_error) |
d6a08f5c | 6241 | error_at (loc, "expression %qE is not a constant expression", t); |
09b42213 | 6242 | return false; |
6243 | ||
bb6e576c | 6244 | case OBJ_TYPE_REF: |
6245 | if (cxx_dialect >= cxx2a) | |
6246 | /* In C++2a virtual calls can be constexpr, don't give up yet. */ | |
6247 | return true; | |
6248 | else if (flags & tf_error) | |
6249 | error_at (loc, "virtual functions cannot be constexpr before C++2a"); | |
6250 | return false; | |
6251 | ||
09b42213 | 6252 | case TYPEID_EXPR: |
6253 | /* -- a typeid expression whose operand is of polymorphic | |
6254 | class type; */ | |
6255 | { | |
6256 | tree e = TREE_OPERAND (t, 0); | |
6257 | if (!TYPE_P (e) && !type_dependent_expression_p (e) | |
6258 | && TYPE_POLYMORPHIC_P (TREE_TYPE (e))) | |
6259 | { | |
6260 | if (flags & tf_error) | |
d6a08f5c | 6261 | error_at (loc, "typeid-expression is not a constant expression " |
6262 | "because %qE is of polymorphic type", e); | |
09b42213 | 6263 | return false; |
6264 | } | |
6265 | return true; | |
6266 | } | |
6267 | ||
57e83b58 | 6268 | case POINTER_DIFF_EXPR: |
09b42213 | 6269 | case MINUS_EXPR: |
09b42213 | 6270 | want_rval = true; |
6271 | goto binary; | |
6272 | ||
6273 | case LT_EXPR: | |
6274 | case LE_EXPR: | |
6275 | case GT_EXPR: | |
6276 | case GE_EXPR: | |
6277 | case EQ_EXPR: | |
6278 | case NE_EXPR: | |
09b42213 | 6279 | want_rval = true; |
6280 | goto binary; | |
6281 | ||
9c96033c | 6282 | case PREINCREMENT_EXPR: |
6283 | case POSTINCREMENT_EXPR: | |
6284 | case PREDECREMENT_EXPR: | |
6285 | case POSTDECREMENT_EXPR: | |
6286 | if (cxx_dialect < cxx14) | |
6287 | goto fail; | |
6288 | goto unary; | |
6289 | ||
09b42213 | 6290 | case BIT_NOT_EXPR: |
6291 | /* A destructor. */ | |
6292 | if (TYPE_P (TREE_OPERAND (t, 0))) | |
6293 | return true; | |
e3533433 | 6294 | /* fall through. */ |
09b42213 | 6295 | |
09b42213 | 6296 | case CONJ_EXPR: |
6297 | case SAVE_EXPR: | |
6298 | case FIX_TRUNC_EXPR: | |
6299 | case FLOAT_EXPR: | |
6300 | case NEGATE_EXPR: | |
6301 | case ABS_EXPR: | |
1c67942e | 6302 | case ABSU_EXPR: |
09b42213 | 6303 | case TRUTH_NOT_EXPR: |
6304 | case FIXED_CONVERT_EXPR: | |
6305 | case UNARY_PLUS_EXPR: | |
6fdf70f5 | 6306 | case UNARY_LEFT_FOLD_EXPR: |
6307 | case UNARY_RIGHT_FOLD_EXPR: | |
9c96033c | 6308 | unary: |
2055d27a | 6309 | return RECUR (TREE_OPERAND (t, 0), rval); |
09b42213 | 6310 | |
6311 | case CAST_EXPR: | |
6312 | case CONST_CAST_EXPR: | |
6313 | case STATIC_CAST_EXPR: | |
6314 | case REINTERPRET_CAST_EXPR: | |
6315 | case IMPLICIT_CONV_EXPR: | |
6316 | if (cxx_dialect < cxx11 | |
6317 | && !dependent_type_p (TREE_TYPE (t)) | |
6318 | && !INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))) | |
6319 | /* In C++98, a conversion to non-integral type can't be part of a | |
6320 | constant expression. */ | |
6321 | { | |
6322 | if (flags & tf_error) | |
d6a08f5c | 6323 | error_at (loc, |
6324 | "cast to non-integral type %qT in a constant expression", | |
6325 | TREE_TYPE (t)); | |
09b42213 | 6326 | return false; |
6327 | } | |
e0ccd480 | 6328 | /* This might be a conversion from a class to a (potentially) literal |
6329 | type. Let's consider it potentially constant since the conversion | |
6330 | might be a constexpr user-defined conversion. */ | |
6331 | else if (cxx_dialect >= cxx11 | |
6332 | && (dependent_type_p (TREE_TYPE (t)) | |
6333 | || !COMPLETE_TYPE_P (TREE_TYPE (t)) | |
6334 | || literal_type_p (TREE_TYPE (t))) | |
6335 | && TREE_OPERAND (t, 0)) | |
6336 | { | |
6337 | tree type = TREE_TYPE (TREE_OPERAND (t, 0)); | |
6338 | /* If this is a dependent type, it could end up being a class | |
6339 | with conversions. */ | |
6340 | if (type == NULL_TREE || WILDCARD_TYPE_P (type)) | |
6341 | return true; | |
6342 | /* Or a non-dependent class which has conversions. */ | |
6343 | else if (CLASS_TYPE_P (type) | |
6344 | && (TYPE_HAS_CONVERSION (type) || dependent_scope_p (type))) | |
6345 | return true; | |
6346 | } | |
09b42213 | 6347 | |
2055d27a | 6348 | return (RECUR (TREE_OPERAND (t, 0), |
90ad495b | 6349 | !TYPE_REF_P (TREE_TYPE (t)))); |
09b42213 | 6350 | |
9c96033c | 6351 | case BIND_EXPR: |
2055d27a | 6352 | return RECUR (BIND_EXPR_BODY (t), want_rval); |
9c96033c | 6353 | |
9c96033c | 6354 | case CLEANUP_POINT_EXPR: |
6355 | case MUST_NOT_THROW_EXPR: | |
6356 | case TRY_CATCH_EXPR: | |
7f67d68c | 6357 | case TRY_BLOCK: |
9c96033c | 6358 | case EH_SPEC_BLOCK: |
6359 | case EXPR_STMT: | |
09b42213 | 6360 | case PAREN_EXPR: |
6361 | case NON_DEPENDENT_EXPR: | |
6362 | /* For convenience. */ | |
d1980671 | 6363 | case LOOP_EXPR: |
6364 | case EXIT_EXPR: | |
2055d27a | 6365 | return RECUR (TREE_OPERAND (t, 0), want_rval); |
09b42213 | 6366 | |
33603066 | 6367 | case DECL_EXPR: |
6368 | tmp = DECL_EXPR_DECL (t); | |
6369 | if (VAR_P (tmp) && !DECL_ARTIFICIAL (tmp)) | |
6370 | { | |
6371 | if (TREE_STATIC (tmp)) | |
6372 | { | |
6373 | if (flags & tf_error) | |
6374 | error_at (DECL_SOURCE_LOCATION (tmp), "%qD declared " | |
8d6486e1 | 6375 | "%<static%> in %<constexpr%> context", tmp); |
33603066 | 6376 | return false; |
6377 | } | |
6378 | else if (CP_DECL_THREAD_LOCAL_P (tmp)) | |
6379 | { | |
6380 | if (flags & tf_error) | |
6381 | error_at (DECL_SOURCE_LOCATION (tmp), "%qD declared " | |
8d6486e1 | 6382 | "%<thread_local%> in %<constexpr%> context", tmp); |
33603066 | 6383 | return false; |
6384 | } | |
282ea908 | 6385 | else if (!check_for_uninitialized_const_var |
6386 | (tmp, /*constexpr_context_p=*/true, flags)) | |
6387 | return false; | |
33603066 | 6388 | } |
6389 | return RECUR (tmp, want_rval); | |
6390 | ||
7f67d68c | 6391 | case TRY_FINALLY_EXPR: |
6392 | return (RECUR (TREE_OPERAND (t, 0), want_rval) | |
6393 | && RECUR (TREE_OPERAND (t, 1), any)); | |
6394 | ||
09b42213 | 6395 | case SCOPE_REF: |
2055d27a | 6396 | return RECUR (TREE_OPERAND (t, 1), want_rval); |
09b42213 | 6397 | |
6398 | case TARGET_EXPR: | |
07d8961c | 6399 | if (!TARGET_EXPR_DIRECT_INIT_P (t) |
6400 | && !literal_type_p (TREE_TYPE (t))) | |
09b42213 | 6401 | { |
6402 | if (flags & tf_error) | |
6403 | { | |
bc35ef65 | 6404 | auto_diagnostic_group d; |
d6a08f5c | 6405 | error_at (loc, "temporary of non-literal type %qT in a " |
6406 | "constant expression", TREE_TYPE (t)); | |
09b42213 | 6407 | explain_non_literal_class (TREE_TYPE (t)); |
6408 | } | |
6409 | return false; | |
6410 | } | |
e3533433 | 6411 | /* FALLTHRU */ |
09b42213 | 6412 | case INIT_EXPR: |
2055d27a | 6413 | return RECUR (TREE_OPERAND (t, 1), rval); |
09b42213 | 6414 | |
6415 | case CONSTRUCTOR: | |
6416 | { | |
6417 | vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (t); | |
6418 | constructor_elt *ce; | |
6419 | for (i = 0; vec_safe_iterate (v, i, &ce); ++i) | |
2055d27a | 6420 | if (!RECUR (ce->value, want_rval)) |
09b42213 | 6421 | return false; |
6422 | return true; | |
6423 | } | |
6424 | ||
6425 | case TREE_LIST: | |
6426 | { | |
6427 | gcc_assert (TREE_PURPOSE (t) == NULL_TREE | |
6428 | || DECL_P (TREE_PURPOSE (t))); | |
2055d27a | 6429 | if (!RECUR (TREE_VALUE (t), want_rval)) |
09b42213 | 6430 | return false; |
6431 | if (TREE_CHAIN (t) == NULL_TREE) | |
6432 | return true; | |
2055d27a | 6433 | return RECUR (TREE_CHAIN (t), want_rval); |
09b42213 | 6434 | } |
6435 | ||
6436 | case TRUNC_DIV_EXPR: | |
6437 | case CEIL_DIV_EXPR: | |
6438 | case FLOOR_DIV_EXPR: | |
6439 | case ROUND_DIV_EXPR: | |
6440 | case TRUNC_MOD_EXPR: | |
6441 | case CEIL_MOD_EXPR: | |
6442 | case ROUND_MOD_EXPR: | |
6443 | { | |
6444 | tree denom = TREE_OPERAND (t, 1); | |
2055d27a | 6445 | if (!RECUR (denom, rval)) |
09b42213 | 6446 | return false; |
6447 | /* We can't call cxx_eval_outermost_constant_expr on an expression | |
21131a05 | 6448 | that hasn't been through instantiate_non_dependent_expr yet. */ |
09b42213 | 6449 | if (!processing_template_decl) |
6450 | denom = cxx_eval_outermost_constant_expr (denom, true); | |
6451 | if (integer_zerop (denom)) | |
6452 | { | |
6453 | if (flags & tf_error) | |
ea034e2c | 6454 | error ("division by zero is not a constant expression"); |
09b42213 | 6455 | return false; |
6456 | } | |
6457 | else | |
6458 | { | |
6459 | want_rval = true; | |
2055d27a | 6460 | return RECUR (TREE_OPERAND (t, 0), want_rval); |
09b42213 | 6461 | } |
6462 | } | |
6463 | ||
6464 | case COMPOUND_EXPR: | |
6465 | { | |
6466 | /* check_return_expr sometimes wraps a TARGET_EXPR in a | |
6467 | COMPOUND_EXPR; don't get confused. Also handle EMPTY_CLASS_EXPR | |
6468 | introduced by build_call_a. */ | |
6469 | tree op0 = TREE_OPERAND (t, 0); | |
6470 | tree op1 = TREE_OPERAND (t, 1); | |
6471 | STRIP_NOPS (op1); | |
6472 | if ((TREE_CODE (op0) == TARGET_EXPR && op1 == TARGET_EXPR_SLOT (op0)) | |
6473 | || TREE_CODE (op1) == EMPTY_CLASS_EXPR) | |
2055d27a | 6474 | return RECUR (op0, want_rval); |
09b42213 | 6475 | else |
6476 | goto binary; | |
6477 | } | |
6478 | ||
6479 | /* If the first operand is the non-short-circuit constant, look at | |
6480 | the second operand; otherwise we only care about the first one for | |
6481 | potentiality. */ | |
6482 | case TRUTH_AND_EXPR: | |
6483 | case TRUTH_ANDIF_EXPR: | |
6484 | tmp = boolean_true_node; | |
6485 | goto truth; | |
6486 | case TRUTH_OR_EXPR: | |
6487 | case TRUTH_ORIF_EXPR: | |
6488 | tmp = boolean_false_node; | |
6489 | truth: | |
6490 | { | |
6491 | tree op = TREE_OPERAND (t, 0); | |
2055d27a | 6492 | if (!RECUR (op, rval)) |
09b42213 | 6493 | return false; |
6494 | if (!processing_template_decl) | |
6495 | op = cxx_eval_outermost_constant_expr (op, true); | |
6496 | if (tree_int_cst_equal (op, tmp)) | |
2055d27a | 6497 | return RECUR (TREE_OPERAND (t, 1), rval); |
09b42213 | 6498 | else |
6499 | return true; | |
6500 | } | |
6501 | ||
6502 | case PLUS_EXPR: | |
6503 | case MULT_EXPR: | |
6504 | case POINTER_PLUS_EXPR: | |
6505 | case RDIV_EXPR: | |
6506 | case EXACT_DIV_EXPR: | |
6507 | case MIN_EXPR: | |
6508 | case MAX_EXPR: | |
6509 | case LSHIFT_EXPR: | |
6510 | case RSHIFT_EXPR: | |
6511 | case LROTATE_EXPR: | |
6512 | case RROTATE_EXPR: | |
6513 | case BIT_IOR_EXPR: | |
6514 | case BIT_XOR_EXPR: | |
6515 | case BIT_AND_EXPR: | |
6516 | case TRUTH_XOR_EXPR: | |
6517 | case UNORDERED_EXPR: | |
6518 | case ORDERED_EXPR: | |
6519 | case UNLT_EXPR: | |
6520 | case UNLE_EXPR: | |
6521 | case UNGT_EXPR: | |
6522 | case UNGE_EXPR: | |
6523 | case UNEQ_EXPR: | |
6524 | case LTGT_EXPR: | |
6525 | case RANGE_EXPR: | |
6526 | case COMPLEX_EXPR: | |
6527 | want_rval = true; | |
6528 | /* Fall through. */ | |
6529 | case ARRAY_REF: | |
6530 | case ARRAY_RANGE_REF: | |
6531 | case MEMBER_REF: | |
6532 | case DOTSTAR_EXPR: | |
f0abe78f | 6533 | case MEM_REF: |
6fdf70f5 | 6534 | case BINARY_LEFT_FOLD_EXPR: |
6535 | case BINARY_RIGHT_FOLD_EXPR: | |
09b42213 | 6536 | binary: |
6537 | for (i = 0; i < 2; ++i) | |
2055d27a | 6538 | if (!RECUR (TREE_OPERAND (t, i), want_rval)) |
09b42213 | 6539 | return false; |
6540 | return true; | |
6541 | ||
09b42213 | 6542 | case VEC_PERM_EXPR: |
6543 | for (i = 0; i < 3; ++i) | |
2055d27a | 6544 | if (!RECUR (TREE_OPERAND (t, i), true)) |
09b42213 | 6545 | return false; |
6546 | return true; | |
6547 | ||
6548 | case COND_EXPR: | |
b0fe8b95 | 6549 | if (COND_EXPR_IS_VEC_DELETE (t)) |
6550 | { | |
6551 | if (flags & tf_error) | |
d6a08f5c | 6552 | error_at (loc, "%<delete[]%> is not a constant expression"); |
b0fe8b95 | 6553 | return false; |
6554 | } | |
6555 | /* Fall through. */ | |
6556 | case IF_STMT: | |
09b42213 | 6557 | case VEC_COND_EXPR: |
6558 | /* If the condition is a known constant, we know which of the legs we | |
6559 | care about; otherwise we only require that the condition and | |
6560 | either of the legs be potentially constant. */ | |
6561 | tmp = TREE_OPERAND (t, 0); | |
2055d27a | 6562 | if (!RECUR (tmp, rval)) |
09b42213 | 6563 | return false; |
6564 | if (!processing_template_decl) | |
6565 | tmp = cxx_eval_outermost_constant_expr (tmp, true); | |
6566 | if (integer_zerop (tmp)) | |
2055d27a | 6567 | return RECUR (TREE_OPERAND (t, 2), want_rval); |
09b42213 | 6568 | else if (TREE_CODE (tmp) == INTEGER_CST) |
2055d27a | 6569 | return RECUR (TREE_OPERAND (t, 1), want_rval); |
09b42213 | 6570 | for (i = 1; i < 3; ++i) |
6571 | if (potential_constant_expression_1 (TREE_OPERAND (t, i), | |
32fee334 | 6572 | want_rval, strict, now, |
6573 | tf_none, jump_target)) | |
09b42213 | 6574 | return true; |
6575 | if (flags & tf_error) | |
d6a08f5c | 6576 | error_at (loc, "expression %qE is not a constant expression", t); |
09b42213 | 6577 | return false; |
6578 | ||
6579 | case VEC_INIT_EXPR: | |
6580 | if (VEC_INIT_EXPR_IS_CONSTEXPR (t)) | |
6581 | return true; | |
6582 | if (flags & tf_error) | |
6583 | { | |
d6a08f5c | 6584 | error_at (loc, "non-constant array initialization"); |
09b42213 | 6585 | diagnose_non_constexpr_vec_init (t); |
6586 | } | |
6587 | return false; | |
6588 | ||
db1ae94f | 6589 | case TYPE_DECL: |
6590 | case TAG_DEFN: | |
6591 | /* We can see these in statement-expressions. */ | |
6592 | return true; | |
6593 | ||
fd130325 | 6594 | case CLEANUP_STMT: |
d2c63826 | 6595 | case EMPTY_CLASS_EXPR: |
38ef3642 | 6596 | case PREDICT_EXPR: |
d2c63826 | 6597 | return false; |
6598 | ||
d1980671 | 6599 | case GOTO_EXPR: |
6600 | { | |
6601 | tree *target = &TREE_OPERAND (t, 0); | |
d40a1eac | 6602 | /* Gotos representing break and continue are OK. */ |
6603 | if (breaks (target) || continues (target)) | |
32fee334 | 6604 | { |
6605 | *jump_target = *target; | |
6606 | return true; | |
6607 | } | |
d40a1eac | 6608 | if (flags & tf_error) |
d6a08f5c | 6609 | error_at (loc, "%<goto%> is not a constant expression"); |
d40a1eac | 6610 | return false; |
d1980671 | 6611 | } |
6612 | ||
24c6ee98 | 6613 | case ANNOTATE_EXPR: |
24c6ee98 | 6614 | return RECUR (TREE_OPERAND (t, 0), rval); |
6615 | ||
09b42213 | 6616 | default: |
6617 | if (objc_is_property_ref (t)) | |
6618 | return false; | |
6619 | ||
6620 | sorry ("unexpected AST of kind %s", get_tree_code_name (TREE_CODE (t))); | |
d40a1eac | 6621 | gcc_unreachable (); |
09b42213 | 6622 | return false; |
6623 | } | |
2055d27a | 6624 | #undef RECUR |
09b42213 | 6625 | } |
6626 | ||
32fee334 | 6627 | bool |
6628 | potential_constant_expression_1 (tree t, bool want_rval, bool strict, bool now, | |
6629 | tsubst_flags_t flags) | |
6630 | { | |
6631 | tree target = NULL_TREE; | |
6632 | return potential_constant_expression_1 (t, want_rval, strict, now, | |
6633 | flags, &target); | |
6634 | } | |
6635 | ||
09b42213 | 6636 | /* The main entry point to the above. */ |
6637 | ||
6638 | bool | |
6639 | potential_constant_expression (tree t) | |
6640 | { | |
7e1f8be4 | 6641 | return potential_constant_expression_1 (t, false, true, false, tf_none); |
09b42213 | 6642 | } |
6643 | ||
6644 | /* As above, but require a constant rvalue. */ | |
6645 | ||
6646 | bool | |
6647 | potential_rvalue_constant_expression (tree t) | |
6648 | { | |
7e1f8be4 | 6649 | return potential_constant_expression_1 (t, true, true, false, tf_none); |
09b42213 | 6650 | } |
6651 | ||
6652 | /* Like above, but complain about non-constant expressions. */ | |
6653 | ||
6654 | bool | |
6655 | require_potential_constant_expression (tree t) | |
6656 | { | |
786721dc | 6657 | return potential_constant_expression_1 (t, false, true, false, |
6658 | tf_warning_or_error); | |
09b42213 | 6659 | } |
6660 | ||
6661 | /* Cross product of the above. */ | |
6662 | ||
6663 | bool | |
6664 | require_potential_rvalue_constant_expression (tree t) | |
6665 | { | |
786721dc | 6666 | return potential_constant_expression_1 (t, true, true, false, |
6667 | tf_warning_or_error); | |
6668 | } | |
6669 | ||
6670 | /* Like above, but don't consider PARM_DECL a potential_constant_expression. */ | |
6671 | ||
6672 | bool | |
6673 | require_rvalue_constant_expression (tree t) | |
6674 | { | |
6675 | return potential_constant_expression_1 (t, true, true, true, | |
6676 | tf_warning_or_error); | |
7e1f8be4 | 6677 | } |
6678 | ||
6679 | /* Like potential_constant_expression, but don't consider possible constexpr | |
6680 | substitution of the current function. That is, PARM_DECL qualifies under | |
6681 | potential_constant_expression, but not here. | |
6682 | ||
6683 | This is basically what you can check when any actual constant values might | |
6684 | be value-dependent. */ | |
6685 | ||
6686 | bool | |
6687 | is_constant_expression (tree t) | |
6688 | { | |
6689 | return potential_constant_expression_1 (t, false, true, true, tf_none); | |
6690 | } | |
6691 | ||
6692 | /* Like above, but complain about non-constant expressions. */ | |
6693 | ||
6694 | bool | |
6695 | require_constant_expression (tree t) | |
6696 | { | |
6697 | return potential_constant_expression_1 (t, false, true, true, | |
6698 | tf_warning_or_error); | |
6699 | } | |
6700 | ||
6701 | /* Like is_constant_expression, but allow const variables that are not allowed | |
6702 | under constexpr rules. */ | |
6703 | ||
6704 | bool | |
6705 | is_static_init_expression (tree t) | |
6706 | { | |
6707 | return potential_constant_expression_1 (t, false, false, true, tf_none); | |
09b42213 | 6708 | } |
6709 | ||
29cf24ec | 6710 | /* Returns true if T is a potential constant expression that is not |
6711 | instantiation-dependent, and therefore a candidate for constant folding even | |
6712 | in a template. */ | |
6713 | ||
6714 | bool | |
7e1f8be4 | 6715 | is_nondependent_constant_expression (tree t) |
29cf24ec | 6716 | { |
6717 | return (!type_unknown_p (t) | |
6718 | && !BRACE_ENCLOSED_INITIALIZER_P (t) | |
7e1f8be4 | 6719 | && is_constant_expression (t) |
29cf24ec | 6720 | && !instantiation_dependent_expression_p (t)); |
6721 | } | |
6722 | ||
6723 | /* Returns true if T is a potential static initializer expression that is not | |
6724 | instantiation-dependent. */ | |
6725 | ||
6726 | bool | |
7e1f8be4 | 6727 | is_nondependent_static_init_expression (tree t) |
29cf24ec | 6728 | { |
6729 | return (!type_unknown_p (t) | |
6730 | && !BRACE_ENCLOSED_INITIALIZER_P (t) | |
7e1f8be4 | 6731 | && is_static_init_expression (t) |
29cf24ec | 6732 | && !instantiation_dependent_expression_p (t)); |
6733 | } | |
6734 | ||
a050099a | 6735 | /* Finalize constexpr processing after parsing. */ |
6736 | ||
6737 | void | |
6738 | fini_constexpr (void) | |
6739 | { | |
6740 | /* The contexpr call and fundef copies tables are no longer needed. */ | |
6741 | constexpr_call_table = NULL; | |
6742 | fundef_copies_table = NULL; | |
6743 | } | |
6744 | ||
09b42213 | 6745 | #include "gt-cp-constexpr.h" |