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Commit | Line | Data |
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13f649f6 JM |
1 | /* Perform -*- C++ -*- constant expression evaluation, including calls to |
2 | constexpr functions. These routines are used both during actual parsing | |
2d76680f PC |
3 | and during the instantiation of template functions. |
4 | ||
85ec4feb | 5 | Copyright (C) 1998-2018 Free Software Foundation, Inc. |
2d76680f PC |
6 | |
7 | This file is part of GCC. | |
8 | ||
9 | GCC is free software; you can redistribute it and/or modify it | |
10 | under the terms of the GNU General Public License as published by | |
11 | the Free Software Foundation; either version 3, or (at your option) | |
12 | any later version. | |
13 | ||
14 | GCC is distributed in the hope that it will be useful, but | |
15 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
17 | General Public License for more details. | |
18 | ||
19 | You should have received a copy of the GNU General Public License | |
20 | along with GCC; see the file COPYING3. If not see | |
21 | <http://www.gnu.org/licenses/>. */ | |
22 | ||
23 | #include "config.h" | |
24 | #include "system.h" | |
25 | #include "coretypes.h" | |
2d76680f | 26 | #include "cp-tree.h" |
2adfab87 | 27 | #include "varasm.h" |
2d76680f PC |
28 | #include "c-family/c-objc.h" |
29 | #include "tree-iterator.h" | |
30 | #include "gimplify.h" | |
31 | #include "builtins.h" | |
60813a46 | 32 | #include "tree-inline.h" |
0b274c17 | 33 | #include "ubsan.h" |
44a845ca | 34 | #include "gimple-fold.h" |
8108ea30 | 35 | #include "timevar.h" |
2d76680f PC |
36 | |
37 | static bool verify_constant (tree, bool, bool *, bool *); | |
38 | #define VERIFY_CONSTANT(X) \ | |
39 | do { \ | |
2b3ab879 | 40 | if (verify_constant ((X), ctx->quiet, non_constant_p, overflow_p)) \ |
2d76680f PC |
41 | return t; \ |
42 | } while (0) | |
43 | ||
44 | /* Returns true iff FUN is an instantiation of a constexpr function | |
45 | template or a defaulted constexpr function. */ | |
46 | ||
47 | bool | |
48 | is_instantiation_of_constexpr (tree fun) | |
49 | { | |
50 | return ((DECL_TEMPLOID_INSTANTIATION (fun) | |
51 | && DECL_DECLARED_CONSTEXPR_P (DECL_TI_TEMPLATE (fun))) | |
52 | || (DECL_DEFAULTED_FN (fun) | |
53 | && DECL_DECLARED_CONSTEXPR_P (fun))); | |
54 | } | |
55 | ||
56 | /* Return true if T is a literal type. */ | |
57 | ||
58 | bool | |
59 | literal_type_p (tree t) | |
60 | { | |
61 | if (SCALAR_TYPE_P (t) | |
b55b02ea | 62 | || VECTOR_TYPE_P (t) |
e42c407c MP |
63 | || TREE_CODE (t) == REFERENCE_TYPE |
64 | || (VOID_TYPE_P (t) && cxx_dialect >= cxx14)) | |
2d76680f PC |
65 | return true; |
66 | if (CLASS_TYPE_P (t)) | |
67 | { | |
68 | t = complete_type (t); | |
69 | gcc_assert (COMPLETE_TYPE_P (t) || errorcount); | |
70 | return CLASSTYPE_LITERAL_P (t); | |
71 | } | |
72 | if (TREE_CODE (t) == ARRAY_TYPE) | |
73 | return literal_type_p (strip_array_types (t)); | |
74 | return false; | |
75 | } | |
76 | ||
77 | /* If DECL is a variable declared `constexpr', require its type | |
78 | be literal. Return the DECL if OK, otherwise NULL. */ | |
79 | ||
80 | tree | |
81 | ensure_literal_type_for_constexpr_object (tree decl) | |
82 | { | |
83 | tree type = TREE_TYPE (decl); | |
84 | if (VAR_P (decl) | |
85 | && (DECL_DECLARED_CONSTEXPR_P (decl) | |
86 | || var_in_constexpr_fn (decl)) | |
87 | && !processing_template_decl) | |
88 | { | |
89 | tree stype = strip_array_types (type); | |
90 | if (CLASS_TYPE_P (stype) && !COMPLETE_TYPE_P (complete_type (stype))) | |
91 | /* Don't complain here, we'll complain about incompleteness | |
92 | when we try to initialize the variable. */; | |
93 | else if (!literal_type_p (type)) | |
94 | { | |
95 | if (DECL_DECLARED_CONSTEXPR_P (decl)) | |
f1eac182 | 96 | { |
84fa214d ML |
97 | error ("the type %qT of %<constexpr%> variable %qD " |
98 | "is not literal", type, decl); | |
f1eac182 JM |
99 | explain_non_literal_class (type); |
100 | } | |
2d76680f | 101 | else |
60813a46 | 102 | { |
5d4e573b | 103 | if (!is_instantiation_of_constexpr (current_function_decl)) |
f1eac182 JM |
104 | { |
105 | error ("variable %qD of non-literal type %qT in %<constexpr%> " | |
106 | "function", decl, type); | |
107 | explain_non_literal_class (type); | |
108 | } | |
60813a46 JM |
109 | cp_function_chain->invalid_constexpr = true; |
110 | } | |
2d76680f PC |
111 | return NULL; |
112 | } | |
113 | } | |
114 | return decl; | |
115 | } | |
116 | ||
117 | /* Representation of entries in the constexpr function definition table. */ | |
118 | ||
119 | struct GTY((for_user)) constexpr_fundef { | |
120 | tree decl; | |
121 | tree body; | |
122 | }; | |
123 | ||
ca752f39 | 124 | struct constexpr_fundef_hasher : ggc_ptr_hash<constexpr_fundef> |
2d76680f PC |
125 | { |
126 | static hashval_t hash (constexpr_fundef *); | |
127 | static bool equal (constexpr_fundef *, constexpr_fundef *); | |
128 | }; | |
129 | ||
130 | /* This table holds all constexpr function definitions seen in | |
131 | the current translation unit. */ | |
132 | ||
133 | static GTY (()) hash_table<constexpr_fundef_hasher> *constexpr_fundef_table; | |
134 | ||
135 | /* Utility function used for managing the constexpr function table. | |
136 | Return true if the entries pointed to by P and Q are for the | |
137 | same constexpr function. */ | |
138 | ||
139 | inline bool | |
140 | constexpr_fundef_hasher::equal (constexpr_fundef *lhs, constexpr_fundef *rhs) | |
141 | { | |
142 | return lhs->decl == rhs->decl; | |
143 | } | |
144 | ||
145 | /* Utility function used for managing the constexpr function table. | |
146 | Return a hash value for the entry pointed to by Q. */ | |
147 | ||
148 | inline hashval_t | |
149 | constexpr_fundef_hasher::hash (constexpr_fundef *fundef) | |
150 | { | |
151 | return DECL_UID (fundef->decl); | |
152 | } | |
153 | ||
154 | /* Return a previously saved definition of function FUN. */ | |
155 | ||
156 | static constexpr_fundef * | |
157 | retrieve_constexpr_fundef (tree fun) | |
158 | { | |
159 | constexpr_fundef fundef = { NULL, NULL }; | |
160 | if (constexpr_fundef_table == NULL) | |
161 | return NULL; | |
162 | ||
163 | fundef.decl = fun; | |
164 | return constexpr_fundef_table->find (&fundef); | |
165 | } | |
166 | ||
167 | /* Check whether the parameter and return types of FUN are valid for a | |
168 | constexpr function, and complain if COMPLAIN. */ | |
169 | ||
98e5a19a | 170 | bool |
2d76680f PC |
171 | is_valid_constexpr_fn (tree fun, bool complain) |
172 | { | |
173 | bool ret = true; | |
174 | ||
31f7f784 | 175 | if (DECL_INHERITED_CTOR (fun) |
2d76680f PC |
176 | && TREE_CODE (fun) == TEMPLATE_DECL) |
177 | { | |
178 | ret = false; | |
179 | if (complain) | |
84fa214d | 180 | error ("inherited constructor %qD is not %<constexpr%>", |
31f7f784 | 181 | DECL_INHERITED_CTOR (fun)); |
2d76680f PC |
182 | } |
183 | else | |
184 | { | |
185 | for (tree parm = FUNCTION_FIRST_USER_PARM (fun); | |
186 | parm != NULL_TREE; parm = TREE_CHAIN (parm)) | |
187 | if (!literal_type_p (TREE_TYPE (parm))) | |
188 | { | |
189 | ret = false; | |
190 | if (complain) | |
191 | { | |
84fa214d | 192 | error ("invalid type for parameter %d of %<constexpr%> " |
2d76680f PC |
193 | "function %q+#D", DECL_PARM_INDEX (parm), fun); |
194 | explain_non_literal_class (TREE_TYPE (parm)); | |
195 | } | |
196 | } | |
197 | } | |
198 | ||
e1bea341 JM |
199 | if (LAMBDA_TYPE_P (CP_DECL_CONTEXT (fun)) && cxx_dialect < cxx17) |
200 | { | |
201 | ret = false; | |
202 | if (complain) | |
203 | inform (DECL_SOURCE_LOCATION (fun), | |
84fa214d | 204 | "lambdas are implicitly %<constexpr%> only in C++17 and later"); |
e1bea341 JM |
205 | } |
206 | else if (!DECL_CONSTRUCTOR_P (fun)) | |
2d76680f PC |
207 | { |
208 | tree rettype = TREE_TYPE (TREE_TYPE (fun)); | |
209 | if (!literal_type_p (rettype)) | |
210 | { | |
211 | ret = false; | |
212 | if (complain) | |
213 | { | |
84fa214d | 214 | error ("invalid return type %qT of %<constexpr%> function %q+D", |
2d76680f PC |
215 | rettype, fun); |
216 | explain_non_literal_class (rettype); | |
217 | } | |
218 | } | |
219 | ||
54069e59 JM |
220 | /* C++14 DR 1684 removed this restriction. */ |
221 | if (cxx_dialect < cxx14 | |
222 | && DECL_NONSTATIC_MEMBER_FUNCTION_P (fun) | |
2d76680f PC |
223 | && !CLASSTYPE_LITERAL_P (DECL_CONTEXT (fun))) |
224 | { | |
225 | ret = false; | |
54069e59 JM |
226 | if (complain |
227 | && pedwarn (DECL_SOURCE_LOCATION (fun), OPT_Wpedantic, | |
84fa214d | 228 | "enclosing class of %<constexpr%> non-static member " |
54069e59 JM |
229 | "function %q+#D is not a literal type", fun)) |
230 | explain_non_literal_class (DECL_CONTEXT (fun)); | |
2d76680f PC |
231 | } |
232 | } | |
233 | else if (CLASSTYPE_VBASECLASSES (DECL_CONTEXT (fun))) | |
234 | { | |
235 | ret = false; | |
236 | if (complain) | |
237 | error ("%q#T has virtual base classes", DECL_CONTEXT (fun)); | |
238 | } | |
239 | ||
240 | return ret; | |
241 | } | |
242 | ||
243 | /* Subroutine of build_data_member_initialization. MEMBER is a COMPONENT_REF | |
244 | for a member of an anonymous aggregate, INIT is the initializer for that | |
245 | member, and VEC_OUTER is the vector of constructor elements for the class | |
246 | whose constructor we are processing. Add the initializer to the vector | |
247 | and return true to indicate success. */ | |
248 | ||
249 | static bool | |
250 | build_anon_member_initialization (tree member, tree init, | |
251 | vec<constructor_elt, va_gc> **vec_outer) | |
252 | { | |
253 | /* MEMBER presents the relevant fields from the inside out, but we need | |
254 | to build up the initializer from the outside in so that we can reuse | |
255 | previously built CONSTRUCTORs if this is, say, the second field in an | |
256 | anonymous struct. So we use a vec as a stack. */ | |
257 | auto_vec<tree, 2> fields; | |
258 | do | |
259 | { | |
260 | fields.safe_push (TREE_OPERAND (member, 1)); | |
261 | member = TREE_OPERAND (member, 0); | |
262 | } | |
263 | while (ANON_AGGR_TYPE_P (TREE_TYPE (member)) | |
264 | && TREE_CODE (member) == COMPONENT_REF); | |
265 | ||
266 | /* VEC has the constructor elements vector for the context of FIELD. | |
267 | If FIELD is an anonymous aggregate, we will push inside it. */ | |
268 | vec<constructor_elt, va_gc> **vec = vec_outer; | |
269 | tree field; | |
270 | while (field = fields.pop(), | |
271 | ANON_AGGR_TYPE_P (TREE_TYPE (field))) | |
272 | { | |
273 | tree ctor; | |
274 | /* If there is already an outer constructor entry for the anonymous | |
275 | aggregate FIELD, use it; otherwise, insert one. */ | |
276 | if (vec_safe_is_empty (*vec) | |
277 | || (*vec)->last().index != field) | |
278 | { | |
279 | ctor = build_constructor (TREE_TYPE (field), NULL); | |
280 | CONSTRUCTOR_APPEND_ELT (*vec, field, ctor); | |
281 | } | |
282 | else | |
283 | ctor = (*vec)->last().value; | |
284 | vec = &CONSTRUCTOR_ELTS (ctor); | |
285 | } | |
286 | ||
287 | /* Now we're at the innermost field, the one that isn't an anonymous | |
288 | aggregate. Add its initializer to the CONSTRUCTOR and we're done. */ | |
289 | gcc_assert (fields.is_empty()); | |
290 | CONSTRUCTOR_APPEND_ELT (*vec, field, init); | |
291 | ||
292 | return true; | |
293 | } | |
294 | ||
295 | /* Subroutine of build_constexpr_constructor_member_initializers. | |
296 | The expression tree T represents a data member initialization | |
297 | in a (constexpr) constructor definition. Build a pairing of | |
298 | the data member with its initializer, and prepend that pair | |
299 | to the existing initialization pair INITS. */ | |
300 | ||
301 | static bool | |
302 | build_data_member_initialization (tree t, vec<constructor_elt, va_gc> **vec) | |
303 | { | |
304 | tree member, init; | |
305 | if (TREE_CODE (t) == CLEANUP_POINT_EXPR) | |
306 | t = TREE_OPERAND (t, 0); | |
307 | if (TREE_CODE (t) == EXPR_STMT) | |
308 | t = TREE_OPERAND (t, 0); | |
309 | if (t == error_mark_node) | |
310 | return false; | |
311 | if (TREE_CODE (t) == STATEMENT_LIST) | |
312 | { | |
313 | tree_stmt_iterator i; | |
314 | for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i)) | |
315 | { | |
316 | if (! build_data_member_initialization (tsi_stmt (i), vec)) | |
317 | return false; | |
318 | } | |
319 | return true; | |
320 | } | |
321 | if (TREE_CODE (t) == CLEANUP_STMT) | |
322 | { | |
323 | /* We can't see a CLEANUP_STMT in a constructor for a literal class, | |
324 | but we can in a constexpr constructor for a non-literal class. Just | |
325 | ignore it; either all the initialization will be constant, in which | |
326 | case the cleanup can't run, or it can't be constexpr. | |
327 | Still recurse into CLEANUP_BODY. */ | |
328 | return build_data_member_initialization (CLEANUP_BODY (t), vec); | |
329 | } | |
330 | if (TREE_CODE (t) == CONVERT_EXPR) | |
331 | t = TREE_OPERAND (t, 0); | |
332 | if (TREE_CODE (t) == INIT_EXPR | |
60813a46 JM |
333 | /* vptr initialization shows up as a MODIFY_EXPR. In C++14 we only |
334 | use what this function builds for cx_check_missing_mem_inits, and | |
335 | assignment in the ctor body doesn't count. */ | |
336 | || (cxx_dialect < cxx14 && TREE_CODE (t) == MODIFY_EXPR)) | |
2d76680f PC |
337 | { |
338 | member = TREE_OPERAND (t, 0); | |
339 | init = break_out_target_exprs (TREE_OPERAND (t, 1)); | |
340 | } | |
341 | else if (TREE_CODE (t) == CALL_EXPR) | |
342 | { | |
60813a46 JM |
343 | tree fn = get_callee_fndecl (t); |
344 | if (!fn || !DECL_CONSTRUCTOR_P (fn)) | |
345 | /* We're only interested in calls to subobject constructors. */ | |
346 | return true; | |
2d76680f PC |
347 | member = CALL_EXPR_ARG (t, 0); |
348 | /* We don't use build_cplus_new here because it complains about | |
349 | abstract bases. Leaving the call unwrapped means that it has the | |
350 | wrong type, but cxx_eval_constant_expression doesn't care. */ | |
351 | init = break_out_target_exprs (t); | |
352 | } | |
353 | else if (TREE_CODE (t) == BIND_EXPR) | |
354 | return build_data_member_initialization (BIND_EXPR_BODY (t), vec); | |
2d76680f | 355 | else |
60813a46 JM |
356 | /* Don't add anything else to the CONSTRUCTOR. */ |
357 | return true; | |
2d76680f PC |
358 | if (INDIRECT_REF_P (member)) |
359 | member = TREE_OPERAND (member, 0); | |
360 | if (TREE_CODE (member) == NOP_EXPR) | |
361 | { | |
362 | tree op = member; | |
363 | STRIP_NOPS (op); | |
364 | if (TREE_CODE (op) == ADDR_EXPR) | |
365 | { | |
366 | gcc_assert (same_type_ignoring_top_level_qualifiers_p | |
367 | (TREE_TYPE (TREE_TYPE (op)), | |
368 | TREE_TYPE (TREE_TYPE (member)))); | |
369 | /* Initializing a cv-qualified member; we need to look through | |
370 | the const_cast. */ | |
371 | member = op; | |
372 | } | |
373 | else if (op == current_class_ptr | |
374 | && (same_type_ignoring_top_level_qualifiers_p | |
375 | (TREE_TYPE (TREE_TYPE (member)), | |
376 | current_class_type))) | |
377 | /* Delegating constructor. */ | |
378 | member = op; | |
379 | else | |
380 | { | |
381 | /* This is an initializer for an empty base; keep it for now so | |
382 | we can check it in cxx_eval_bare_aggregate. */ | |
383 | gcc_assert (is_empty_class (TREE_TYPE (TREE_TYPE (member)))); | |
384 | } | |
385 | } | |
386 | if (TREE_CODE (member) == ADDR_EXPR) | |
387 | member = TREE_OPERAND (member, 0); | |
388 | if (TREE_CODE (member) == COMPONENT_REF) | |
389 | { | |
390 | tree aggr = TREE_OPERAND (member, 0); | |
8cb7aaa1 JM |
391 | if (TREE_CODE (aggr) == VAR_DECL) |
392 | /* Initializing a local variable, don't add anything. */ | |
393 | return true; | |
2d76680f PC |
394 | if (TREE_CODE (aggr) != COMPONENT_REF) |
395 | /* Normal member initialization. */ | |
396 | member = TREE_OPERAND (member, 1); | |
397 | else if (ANON_AGGR_TYPE_P (TREE_TYPE (aggr))) | |
398 | /* Initializing a member of an anonymous union. */ | |
399 | return build_anon_member_initialization (member, init, vec); | |
400 | else | |
401 | /* We're initializing a vtable pointer in a base. Leave it as | |
402 | COMPONENT_REF so we remember the path to get to the vfield. */ | |
403 | gcc_assert (TREE_TYPE (member) == vtbl_ptr_type_node); | |
404 | } | |
405 | ||
49b5925f JM |
406 | /* Value-initialization can produce multiple initializers for the |
407 | same field; use the last one. */ | |
408 | if (!vec_safe_is_empty (*vec) && (*vec)->last().index == member) | |
409 | (*vec)->last().value = init; | |
410 | else | |
411 | CONSTRUCTOR_APPEND_ELT (*vec, member, init); | |
2d76680f PC |
412 | return true; |
413 | } | |
414 | ||
415 | /* Subroutine of check_constexpr_ctor_body_1 and constexpr_fn_retval. | |
416 | In C++11 mode checks that the TYPE_DECLs in the BIND_EXPR_VARS of a | |
417 | BIND_EXPR conform to 7.1.5/3/4 on typedef and alias declarations. */ | |
418 | ||
419 | static bool | |
420 | check_constexpr_bind_expr_vars (tree t) | |
421 | { | |
422 | gcc_assert (TREE_CODE (t) == BIND_EXPR); | |
423 | ||
2d76680f PC |
424 | for (tree var = BIND_EXPR_VARS (t); var; var = DECL_CHAIN (var)) |
425 | if (TREE_CODE (var) == TYPE_DECL | |
4414e22e PC |
426 | && DECL_IMPLICIT_TYPEDEF_P (var) |
427 | && !LAMBDA_TYPE_P (TREE_TYPE (var))) | |
2d76680f PC |
428 | return false; |
429 | return true; | |
430 | } | |
431 | ||
432 | /* Subroutine of check_constexpr_ctor_body. */ | |
433 | ||
434 | static bool | |
435 | check_constexpr_ctor_body_1 (tree last, tree list) | |
436 | { | |
437 | switch (TREE_CODE (list)) | |
438 | { | |
439 | case DECL_EXPR: | |
a0008434 MP |
440 | if (TREE_CODE (DECL_EXPR_DECL (list)) == USING_DECL |
441 | || TREE_CODE (DECL_EXPR_DECL (list)) == TYPE_DECL) | |
2d76680f | 442 | return true; |
2d76680f PC |
443 | return false; |
444 | ||
445 | case CLEANUP_POINT_EXPR: | |
446 | return check_constexpr_ctor_body (last, TREE_OPERAND (list, 0), | |
447 | /*complain=*/false); | |
448 | ||
449 | case BIND_EXPR: | |
450 | if (!check_constexpr_bind_expr_vars (list) | |
451 | || !check_constexpr_ctor_body (last, BIND_EXPR_BODY (list), | |
452 | /*complain=*/false)) | |
453 | return false; | |
454 | return true; | |
455 | ||
456 | case USING_STMT: | |
457 | case STATIC_ASSERT: | |
96a95ac1 | 458 | case DEBUG_BEGIN_STMT: |
2d76680f PC |
459 | return true; |
460 | ||
461 | default: | |
462 | return false; | |
463 | } | |
464 | } | |
465 | ||
466 | /* Make sure that there are no statements after LAST in the constructor | |
467 | body represented by LIST. */ | |
468 | ||
469 | bool | |
470 | check_constexpr_ctor_body (tree last, tree list, bool complain) | |
471 | { | |
60813a46 JM |
472 | /* C++14 doesn't require a constexpr ctor to have an empty body. */ |
473 | if (cxx_dialect >= cxx14) | |
474 | return true; | |
475 | ||
2d76680f PC |
476 | bool ok = true; |
477 | if (TREE_CODE (list) == STATEMENT_LIST) | |
478 | { | |
479 | tree_stmt_iterator i = tsi_last (list); | |
480 | for (; !tsi_end_p (i); tsi_prev (&i)) | |
481 | { | |
482 | tree t = tsi_stmt (i); | |
483 | if (t == last) | |
484 | break; | |
485 | if (!check_constexpr_ctor_body_1 (last, t)) | |
486 | { | |
487 | ok = false; | |
488 | break; | |
489 | } | |
490 | } | |
491 | } | |
492 | else if (list != last | |
493 | && !check_constexpr_ctor_body_1 (last, list)) | |
494 | ok = false; | |
495 | if (!ok) | |
496 | { | |
497 | if (complain) | |
84fa214d | 498 | error ("%<constexpr%> constructor does not have empty body"); |
2d76680f PC |
499 | DECL_DECLARED_CONSTEXPR_P (current_function_decl) = false; |
500 | } | |
501 | return ok; | |
502 | } | |
503 | ||
504 | /* V is a vector of constructor elements built up for the base and member | |
505 | initializers of a constructor for TYPE. They need to be in increasing | |
506 | offset order, which they might not be yet if TYPE has a primary base | |
507 | which is not first in the base-clause or a vptr and at least one base | |
508 | all of which are non-primary. */ | |
509 | ||
510 | static vec<constructor_elt, va_gc> * | |
511 | sort_constexpr_mem_initializers (tree type, vec<constructor_elt, va_gc> *v) | |
512 | { | |
513 | tree pri = CLASSTYPE_PRIMARY_BINFO (type); | |
514 | tree field_type; | |
515 | unsigned i; | |
516 | constructor_elt *ce; | |
517 | ||
518 | if (pri) | |
519 | field_type = BINFO_TYPE (pri); | |
520 | else if (TYPE_CONTAINS_VPTR_P (type)) | |
521 | field_type = vtbl_ptr_type_node; | |
522 | else | |
523 | return v; | |
524 | ||
525 | /* Find the element for the primary base or vptr and move it to the | |
526 | beginning of the vec. */ | |
527 | for (i = 0; vec_safe_iterate (v, i, &ce); ++i) | |
528 | if (TREE_TYPE (ce->index) == field_type) | |
529 | break; | |
530 | ||
531 | if (i > 0 && i < vec_safe_length (v)) | |
532 | { | |
533 | vec<constructor_elt, va_gc> &vref = *v; | |
534 | constructor_elt elt = vref[i]; | |
535 | for (; i > 0; --i) | |
536 | vref[i] = vref[i-1]; | |
537 | vref[0] = elt; | |
538 | } | |
539 | ||
540 | return v; | |
541 | } | |
542 | ||
543 | /* Build compile-time evalable representations of member-initializer list | |
544 | for a constexpr constructor. */ | |
545 | ||
546 | static tree | |
547 | build_constexpr_constructor_member_initializers (tree type, tree body) | |
548 | { | |
549 | vec<constructor_elt, va_gc> *vec = NULL; | |
550 | bool ok = true; | |
fa837fb6 JM |
551 | while (true) |
552 | switch (TREE_CODE (body)) | |
553 | { | |
554 | case MUST_NOT_THROW_EXPR: | |
555 | case EH_SPEC_BLOCK: | |
556 | body = TREE_OPERAND (body, 0); | |
557 | break; | |
558 | ||
559 | case STATEMENT_LIST: | |
560 | for (tree_stmt_iterator i = tsi_start (body); | |
561 | !tsi_end_p (i); tsi_next (&i)) | |
562 | { | |
563 | body = tsi_stmt (i); | |
564 | if (TREE_CODE (body) == BIND_EXPR) | |
565 | break; | |
566 | } | |
567 | break; | |
568 | ||
569 | case BIND_EXPR: | |
570 | body = BIND_EXPR_BODY (body); | |
571 | goto found; | |
572 | ||
573 | default: | |
574 | gcc_unreachable (); | |
58cc255c | 575 | } |
fa837fb6 | 576 | found: |
2d76680f PC |
577 | if (TREE_CODE (body) == CLEANUP_POINT_EXPR) |
578 | { | |
579 | body = TREE_OPERAND (body, 0); | |
580 | if (TREE_CODE (body) == EXPR_STMT) | |
581 | body = TREE_OPERAND (body, 0); | |
582 | if (TREE_CODE (body) == INIT_EXPR | |
583 | && (same_type_ignoring_top_level_qualifiers_p | |
584 | (TREE_TYPE (TREE_OPERAND (body, 0)), | |
585 | current_class_type))) | |
586 | { | |
587 | /* Trivial copy. */ | |
588 | return TREE_OPERAND (body, 1); | |
589 | } | |
590 | ok = build_data_member_initialization (body, &vec); | |
591 | } | |
592 | else if (TREE_CODE (body) == STATEMENT_LIST) | |
593 | { | |
594 | tree_stmt_iterator i; | |
595 | for (i = tsi_start (body); !tsi_end_p (i); tsi_next (&i)) | |
596 | { | |
597 | ok = build_data_member_initialization (tsi_stmt (i), &vec); | |
598 | if (!ok) | |
599 | break; | |
600 | } | |
601 | } | |
602 | else if (TREE_CODE (body) == TRY_BLOCK) | |
603 | { | |
604 | error ("body of %<constexpr%> constructor cannot be " | |
605 | "a function-try-block"); | |
606 | return error_mark_node; | |
607 | } | |
608 | else if (EXPR_P (body)) | |
609 | ok = build_data_member_initialization (body, &vec); | |
610 | else | |
611 | gcc_assert (errorcount > 0); | |
612 | if (ok) | |
613 | { | |
614 | if (vec_safe_length (vec) > 0) | |
615 | { | |
616 | /* In a delegating constructor, return the target. */ | |
617 | constructor_elt *ce = &(*vec)[0]; | |
618 | if (ce->index == current_class_ptr) | |
619 | { | |
620 | body = ce->value; | |
621 | vec_free (vec); | |
622 | return body; | |
623 | } | |
624 | } | |
625 | vec = sort_constexpr_mem_initializers (type, vec); | |
626 | return build_constructor (type, vec); | |
627 | } | |
628 | else | |
629 | return error_mark_node; | |
630 | } | |
631 | ||
1b6fa695 ML |
632 | /* We have an expression tree T that represents a call, either CALL_EXPR |
633 | or AGGR_INIT_EXPR. If the call is lexically to a named function, | |
634 | retrun the _DECL for that function. */ | |
635 | ||
636 | static tree | |
637 | get_function_named_in_call (tree t) | |
638 | { | |
639 | tree fun = cp_get_callee (t); | |
640 | if (fun && TREE_CODE (fun) == ADDR_EXPR | |
641 | && TREE_CODE (TREE_OPERAND (fun, 0)) == FUNCTION_DECL) | |
642 | fun = TREE_OPERAND (fun, 0); | |
643 | return fun; | |
644 | } | |
645 | ||
2d76680f PC |
646 | /* Subroutine of register_constexpr_fundef. BODY is the body of a function |
647 | declared to be constexpr, or a sub-statement thereof. Returns the | |
648 | return value if suitable, error_mark_node for a statement not allowed in | |
649 | a constexpr function, or NULL_TREE if no return value was found. */ | |
650 | ||
651 | static tree | |
652 | constexpr_fn_retval (tree body) | |
653 | { | |
654 | switch (TREE_CODE (body)) | |
655 | { | |
656 | case STATEMENT_LIST: | |
657 | { | |
658 | tree_stmt_iterator i; | |
659 | tree expr = NULL_TREE; | |
660 | for (i = tsi_start (body); !tsi_end_p (i); tsi_next (&i)) | |
661 | { | |
662 | tree s = constexpr_fn_retval (tsi_stmt (i)); | |
663 | if (s == error_mark_node) | |
664 | return error_mark_node; | |
665 | else if (s == NULL_TREE) | |
666 | /* Keep iterating. */; | |
667 | else if (expr) | |
668 | /* Multiple return statements. */ | |
669 | return error_mark_node; | |
670 | else | |
671 | expr = s; | |
672 | } | |
673 | return expr; | |
674 | } | |
675 | ||
676 | case RETURN_EXPR: | |
677 | return break_out_target_exprs (TREE_OPERAND (body, 0)); | |
678 | ||
679 | case DECL_EXPR: | |
0162cb3b PC |
680 | { |
681 | tree decl = DECL_EXPR_DECL (body); | |
682 | if (TREE_CODE (decl) == USING_DECL | |
683 | /* Accept __func__, __FUNCTION__, and __PRETTY_FUNCTION__. */ | |
684 | || DECL_ARTIFICIAL (decl)) | |
685 | return NULL_TREE; | |
686 | return error_mark_node; | |
687 | } | |
2d76680f PC |
688 | |
689 | case CLEANUP_POINT_EXPR: | |
690 | return constexpr_fn_retval (TREE_OPERAND (body, 0)); | |
691 | ||
692 | case BIND_EXPR: | |
693 | if (!check_constexpr_bind_expr_vars (body)) | |
694 | return error_mark_node; | |
695 | return constexpr_fn_retval (BIND_EXPR_BODY (body)); | |
696 | ||
697 | case USING_STMT: | |
96a95ac1 | 698 | case DEBUG_BEGIN_STMT: |
2d76680f PC |
699 | return NULL_TREE; |
700 | ||
1b6fa695 ML |
701 | case CALL_EXPR: |
702 | { | |
703 | tree fun = get_function_named_in_call (body); | |
704 | if (fun != NULL_TREE | |
705 | && DECL_FUNCTION_CODE (fun) == BUILT_IN_UNREACHABLE) | |
706 | return NULL_TREE; | |
707 | } | |
708 | /* Fallthru. */ | |
709 | ||
2d76680f PC |
710 | default: |
711 | return error_mark_node; | |
712 | } | |
713 | } | |
714 | ||
715 | /* Subroutine of register_constexpr_fundef. BODY is the DECL_SAVED_TREE of | |
716 | FUN; do the necessary transformations to turn it into a single expression | |
717 | that we can store in the hash table. */ | |
718 | ||
719 | static tree | |
720 | massage_constexpr_body (tree fun, tree body) | |
721 | { | |
722 | if (DECL_CONSTRUCTOR_P (fun)) | |
723 | body = build_constexpr_constructor_member_initializers | |
724 | (DECL_CONTEXT (fun), body); | |
60813a46 | 725 | else if (cxx_dialect < cxx14) |
2d76680f PC |
726 | { |
727 | if (TREE_CODE (body) == EH_SPEC_BLOCK) | |
728 | body = EH_SPEC_STMTS (body); | |
729 | if (TREE_CODE (body) == MUST_NOT_THROW_EXPR) | |
730 | body = TREE_OPERAND (body, 0); | |
731 | body = constexpr_fn_retval (body); | |
732 | } | |
733 | return body; | |
734 | } | |
735 | ||
3e4b91f2 NS |
736 | /* CTYPE is a type constructed from BODY. Return true if some |
737 | bases/fields are uninitialized, and complain if COMPLAIN. */ | |
2d76680f PC |
738 | |
739 | static bool | |
3e4b91f2 | 740 | cx_check_missing_mem_inits (tree ctype, tree body, bool complain) |
2d76680f | 741 | { |
3e4b91f2 NS |
742 | unsigned nelts = 0; |
743 | ||
744 | if (body) | |
745 | { | |
746 | if (TREE_CODE (body) != CONSTRUCTOR) | |
747 | return false; | |
748 | nelts = CONSTRUCTOR_NELTS (body); | |
749 | } | |
750 | tree field = TYPE_FIELDS (ctype); | |
2d76680f PC |
751 | |
752 | if (TREE_CODE (ctype) == UNION_TYPE) | |
753 | { | |
754 | if (nelts == 0 && next_initializable_field (field)) | |
755 | { | |
756 | if (complain) | |
757 | error ("%<constexpr%> constructor for union %qT must " | |
758 | "initialize exactly one non-static data member", ctype); | |
759 | return true; | |
760 | } | |
761 | return false; | |
762 | } | |
763 | ||
3e4b91f2 NS |
764 | /* Iterate over the CONSTRUCTOR, checking any missing fields don't |
765 | need an explicit initialization. */ | |
766 | bool bad = false; | |
767 | for (unsigned i = 0; i <= nelts; ++i) | |
2d76680f | 768 | { |
3e4b91f2 NS |
769 | tree index = NULL_TREE; |
770 | if (i < nelts) | |
2d76680f PC |
771 | { |
772 | index = CONSTRUCTOR_ELT (body, i)->index; | |
773 | /* Skip base and vtable inits. */ | |
774 | if (TREE_CODE (index) != FIELD_DECL | |
775 | || DECL_ARTIFICIAL (index)) | |
776 | continue; | |
777 | } | |
3e4b91f2 | 778 | |
2d76680f PC |
779 | for (; field != index; field = DECL_CHAIN (field)) |
780 | { | |
781 | tree ftype; | |
3e4b91f2 NS |
782 | if (TREE_CODE (field) != FIELD_DECL) |
783 | continue; | |
784 | if (DECL_C_BIT_FIELD (field) && !DECL_NAME (field)) | |
2d76680f | 785 | continue; |
3e4b91f2 NS |
786 | if (DECL_ARTIFICIAL (field)) |
787 | continue; | |
788 | if (ANON_AGGR_TYPE_P (TREE_TYPE (field))) | |
789 | { | |
790 | /* Recurse to check the anonummous aggregate member. */ | |
791 | bad |= cx_check_missing_mem_inits | |
792 | (TREE_TYPE (field), NULL_TREE, complain); | |
793 | if (bad && !complain) | |
794 | return true; | |
795 | continue; | |
796 | } | |
2d76680f PC |
797 | ftype = strip_array_types (TREE_TYPE (field)); |
798 | if (type_has_constexpr_default_constructor (ftype)) | |
799 | { | |
800 | /* It's OK to skip a member with a trivial constexpr ctor. | |
801 | A constexpr ctor that isn't trivial should have been | |
802 | added in by now. */ | |
803 | gcc_checking_assert (!TYPE_HAS_COMPLEX_DFLT (ftype) | |
804 | || errorcount != 0); | |
805 | continue; | |
806 | } | |
807 | if (!complain) | |
808 | return true; | |
b8cd3996 JM |
809 | error ("member %qD must be initialized by mem-initializer " |
810 | "in %<constexpr%> constructor", field); | |
811 | inform (DECL_SOURCE_LOCATION (field), "declared here"); | |
2d76680f PC |
812 | bad = true; |
813 | } | |
814 | if (field == NULL_TREE) | |
815 | break; | |
3e4b91f2 NS |
816 | |
817 | if (ANON_AGGR_TYPE_P (TREE_TYPE (index))) | |
818 | { | |
819 | /* Check the anonymous aggregate initializer is valid. */ | |
820 | bad |= cx_check_missing_mem_inits | |
821 | (TREE_TYPE (index), CONSTRUCTOR_ELT (body, i)->value, complain); | |
822 | if (bad && !complain) | |
823 | return true; | |
824 | } | |
2d76680f PC |
825 | field = DECL_CHAIN (field); |
826 | } | |
827 | ||
828 | return bad; | |
829 | } | |
830 | ||
831 | /* We are processing the definition of the constexpr function FUN. | |
832 | Check that its BODY fulfills the propriate requirements and | |
833 | enter it in the constexpr function definition table. | |
834 | For constructor BODY is actually the TREE_LIST of the | |
835 | member-initializer list. */ | |
836 | ||
837 | tree | |
838 | register_constexpr_fundef (tree fun, tree body) | |
839 | { | |
840 | constexpr_fundef entry; | |
841 | constexpr_fundef **slot; | |
842 | ||
843 | if (!is_valid_constexpr_fn (fun, !DECL_GENERATED_P (fun))) | |
844 | return NULL; | |
845 | ||
ca30abcd JM |
846 | tree massaged = massage_constexpr_body (fun, body); |
847 | if (massaged == NULL_TREE || massaged == error_mark_node) | |
2d76680f PC |
848 | { |
849 | if (!DECL_CONSTRUCTOR_P (fun)) | |
84fa214d ML |
850 | error ("body of %<constexpr%> function %qD not a return-statement", |
851 | fun); | |
2d76680f PC |
852 | return NULL; |
853 | } | |
854 | ||
ca30abcd | 855 | if (!potential_rvalue_constant_expression (massaged)) |
2d76680f PC |
856 | { |
857 | if (!DECL_GENERATED_P (fun)) | |
ca30abcd | 858 | require_potential_rvalue_constant_expression (massaged); |
2d76680f PC |
859 | return NULL; |
860 | } | |
861 | ||
862 | if (DECL_CONSTRUCTOR_P (fun) | |
3e4b91f2 NS |
863 | && cx_check_missing_mem_inits (DECL_CONTEXT (fun), |
864 | massaged, !DECL_GENERATED_P (fun))) | |
2d76680f PC |
865 | return NULL; |
866 | ||
867 | /* Create the constexpr function table if necessary. */ | |
868 | if (constexpr_fundef_table == NULL) | |
869 | constexpr_fundef_table | |
870 | = hash_table<constexpr_fundef_hasher>::create_ggc (101); | |
871 | ||
872 | entry.decl = fun; | |
873 | entry.body = body; | |
874 | slot = constexpr_fundef_table->find_slot (&entry, INSERT); | |
875 | ||
876 | gcc_assert (*slot == NULL); | |
877 | *slot = ggc_alloc<constexpr_fundef> (); | |
878 | **slot = entry; | |
879 | ||
880 | return fun; | |
881 | } | |
882 | ||
883 | /* FUN is a non-constexpr function called in a context that requires a | |
884 | constant expression. If it comes from a constexpr template, explain why | |
885 | the instantiation isn't constexpr. */ | |
886 | ||
887 | void | |
888 | explain_invalid_constexpr_fn (tree fun) | |
889 | { | |
890 | static hash_set<tree> *diagnosed; | |
891 | tree body; | |
892 | location_t save_loc; | |
98e5a19a | 893 | /* Only diagnose defaulted functions, lambdas, or instantiations. */ |
2d76680f | 894 | if (!DECL_DEFAULTED_FN (fun) |
98e5a19a | 895 | && !LAMBDA_TYPE_P (CP_DECL_CONTEXT (fun)) |
2d76680f PC |
896 | && !is_instantiation_of_constexpr (fun)) |
897 | return; | |
898 | if (diagnosed == NULL) | |
899 | diagnosed = new hash_set<tree>; | |
900 | if (diagnosed->add (fun)) | |
901 | /* Already explained. */ | |
902 | return; | |
903 | ||
904 | save_loc = input_location; | |
98e5a19a JM |
905 | if (!lambda_static_thunk_p (fun)) |
906 | { | |
907 | /* Diagnostics should completely ignore the static thunk, so leave | |
908 | input_location set to our caller's location. */ | |
909 | input_location = DECL_SOURCE_LOCATION (fun); | |
910 | inform (input_location, | |
84fa214d | 911 | "%qD is not usable as a %<constexpr%> function because:", fun); |
98e5a19a | 912 | } |
2d76680f PC |
913 | /* First check the declaration. */ |
914 | if (is_valid_constexpr_fn (fun, true)) | |
915 | { | |
916 | /* Then if it's OK, the body. */ | |
98e5a19a JM |
917 | if (!DECL_DECLARED_CONSTEXPR_P (fun) |
918 | && !LAMBDA_TYPE_P (CP_DECL_CONTEXT (fun))) | |
2d76680f PC |
919 | explain_implicit_non_constexpr (fun); |
920 | else | |
921 | { | |
922 | body = massage_constexpr_body (fun, DECL_SAVED_TREE (fun)); | |
923 | require_potential_rvalue_constant_expression (body); | |
924 | if (DECL_CONSTRUCTOR_P (fun)) | |
3e4b91f2 | 925 | cx_check_missing_mem_inits (DECL_CONTEXT (fun), body, true); |
2d76680f PC |
926 | } |
927 | } | |
928 | input_location = save_loc; | |
929 | } | |
930 | ||
931 | /* Objects of this type represent calls to constexpr functions | |
932 | along with the bindings of parameters to their arguments, for | |
933 | the purpose of compile time evaluation. */ | |
934 | ||
935 | struct GTY((for_user)) constexpr_call { | |
936 | /* Description of the constexpr function definition. */ | |
937 | constexpr_fundef *fundef; | |
938 | /* Parameter bindings environment. A TREE_LIST where each TREE_PURPOSE | |
939 | is a parameter _DECL and the TREE_VALUE is the value of the parameter. | |
940 | Note: This arrangement is made to accommodate the use of | |
941 | iterative_hash_template_arg (see pt.c). If you change this | |
942 | representation, also change the hash calculation in | |
943 | cxx_eval_call_expression. */ | |
944 | tree bindings; | |
945 | /* Result of the call. | |
946 | NULL means the call is being evaluated. | |
947 | error_mark_node means that the evaluation was erroneous; | |
948 | otherwise, the actuall value of the call. */ | |
949 | tree result; | |
950 | /* The hash of this call; we remember it here to avoid having to | |
951 | recalculate it when expanding the hash table. */ | |
952 | hashval_t hash; | |
953 | }; | |
954 | ||
ca752f39 | 955 | struct constexpr_call_hasher : ggc_ptr_hash<constexpr_call> |
2d76680f PC |
956 | { |
957 | static hashval_t hash (constexpr_call *); | |
958 | static bool equal (constexpr_call *, constexpr_call *); | |
3e605b20 JM |
959 | }; |
960 | ||
4b390698 JJ |
961 | enum constexpr_switch_state { |
962 | /* Used when processing a switch for the first time by cxx_eval_switch_expr | |
963 | and default: label for that switch has not been seen yet. */ | |
964 | css_default_not_seen, | |
965 | /* Used when processing a switch for the first time by cxx_eval_switch_expr | |
966 | and default: label for that switch has been seen already. */ | |
967 | css_default_seen, | |
968 | /* Used when processing a switch for the second time by | |
969 | cxx_eval_switch_expr, where default: label should match. */ | |
970 | css_default_processing | |
971 | }; | |
972 | ||
3e605b20 JM |
973 | /* The constexpr expansion context. CALL is the current function |
974 | expansion, CTOR is the current aggregate initializer, OBJECT is the | |
975 | object being initialized by CTOR, either a VAR_DECL or a _REF. VALUES | |
976 | is a map of values of variables initialized within the expression. */ | |
977 | ||
978 | struct constexpr_ctx { | |
13f649f6 | 979 | /* The innermost call we're evaluating. */ |
3e605b20 | 980 | constexpr_call *call; |
13f649f6 JM |
981 | /* Values for any temporaries or local variables within the |
982 | constant-expression. */ | |
3e605b20 | 983 | hash_map<tree,tree> *values; |
39dce2b7 JM |
984 | /* SAVE_EXPRs that we've seen within the current LOOP_EXPR. NULL if we |
985 | aren't inside a loop. */ | |
986 | hash_set<tree> *save_exprs; | |
13f649f6 JM |
987 | /* The CONSTRUCTOR we're currently building up for an aggregate |
988 | initializer. */ | |
3e605b20 | 989 | tree ctor; |
13f649f6 | 990 | /* The object we're building the CONSTRUCTOR for. */ |
3e605b20 | 991 | tree object; |
4b390698 JJ |
992 | /* If inside SWITCH_EXPR. */ |
993 | constexpr_switch_state *css_state; | |
13f649f6 | 994 | /* Whether we should error on a non-constant expression or fail quietly. */ |
2b3ab879 | 995 | bool quiet; |
13f649f6 JM |
996 | /* Whether we are strictly conforming to constant expression rules or |
997 | trying harder to get a constant value. */ | |
69eb4fde | 998 | bool strict; |
3e605b20 | 999 | }; |
2d76680f PC |
1000 | |
1001 | /* A table of all constexpr calls that have been evaluated by the | |
1002 | compiler in this translation unit. */ | |
1003 | ||
97f3003f | 1004 | static GTY (()) hash_table<constexpr_call_hasher> *constexpr_call_table; |
2d76680f | 1005 | |
3e605b20 | 1006 | static tree cxx_eval_constant_expression (const constexpr_ctx *, tree, |
5a804683 | 1007 | bool, bool *, bool *, tree * = NULL); |
2d76680f PC |
1008 | |
1009 | /* Compute a hash value for a constexpr call representation. */ | |
1010 | ||
1011 | inline hashval_t | |
1012 | constexpr_call_hasher::hash (constexpr_call *info) | |
1013 | { | |
1014 | return info->hash; | |
1015 | } | |
1016 | ||
1017 | /* Return true if the objects pointed to by P and Q represent calls | |
1018 | to the same constexpr function with the same arguments. | |
1019 | Otherwise, return false. */ | |
1020 | ||
1021 | bool | |
1022 | constexpr_call_hasher::equal (constexpr_call *lhs, constexpr_call *rhs) | |
1023 | { | |
1024 | tree lhs_bindings; | |
1025 | tree rhs_bindings; | |
1026 | if (lhs == rhs) | |
1027 | return 1; | |
1028 | if (!constexpr_fundef_hasher::equal (lhs->fundef, rhs->fundef)) | |
1029 | return 0; | |
1030 | lhs_bindings = lhs->bindings; | |
1031 | rhs_bindings = rhs->bindings; | |
1032 | while (lhs_bindings != NULL && rhs_bindings != NULL) | |
1033 | { | |
1034 | tree lhs_arg = TREE_VALUE (lhs_bindings); | |
1035 | tree rhs_arg = TREE_VALUE (rhs_bindings); | |
1036 | gcc_assert (TREE_TYPE (lhs_arg) == TREE_TYPE (rhs_arg)); | |
1037 | if (!cp_tree_equal (lhs_arg, rhs_arg)) | |
1038 | return 0; | |
1039 | lhs_bindings = TREE_CHAIN (lhs_bindings); | |
1040 | rhs_bindings = TREE_CHAIN (rhs_bindings); | |
1041 | } | |
1042 | return lhs_bindings == rhs_bindings; | |
1043 | } | |
1044 | ||
1045 | /* Initialize the constexpr call table, if needed. */ | |
1046 | ||
1047 | static void | |
1048 | maybe_initialize_constexpr_call_table (void) | |
1049 | { | |
1050 | if (constexpr_call_table == NULL) | |
1051 | constexpr_call_table = hash_table<constexpr_call_hasher>::create_ggc (101); | |
1052 | } | |
1053 | ||
c0daf32d PP |
1054 | /* During constexpr CALL_EXPR evaluation, to avoid issues with sharing when |
1055 | a function happens to get called recursively, we unshare the callee | |
1056 | function's body and evaluate this unshared copy instead of evaluating the | |
1057 | original body. | |
1058 | ||
1059 | FUNDEF_COPIES_TABLE is a per-function freelist of these unshared function | |
1060 | copies. The underlying data structure of FUNDEF_COPIES_TABLE is a hash_map | |
97f3003f JM |
1061 | that's keyed off of the original FUNCTION_DECL and whose value is a |
1062 | TREE_LIST of this function's unused copies awaiting reuse. | |
c0daf32d | 1063 | |
97f3003f | 1064 | This is not GC-deletable to avoid GC affecting UID generation. */ |
c0daf32d | 1065 | |
97f3003f | 1066 | static GTY(()) hash_map<tree, tree> *fundef_copies_table; |
c0daf32d PP |
1067 | |
1068 | /* Initialize FUNDEF_COPIES_TABLE if it's not initialized. */ | |
1069 | ||
1070 | static void | |
1071 | maybe_initialize_fundef_copies_table () | |
1072 | { | |
97f3003f JM |
1073 | if (fundef_copies_table == NULL) |
1074 | fundef_copies_table = hash_map<tree,tree>::create_ggc (101); | |
c0daf32d PP |
1075 | } |
1076 | ||
1077 | /* Reuse a copy or create a new unshared copy of the function FUN. | |
3c98ff9b NS |
1078 | Return this copy. We use a TREE_LIST whose PURPOSE is body, VALUE |
1079 | is parms, TYPE is result. */ | |
c0daf32d | 1080 | |
97f3003f | 1081 | static tree |
c0daf32d PP |
1082 | get_fundef_copy (tree fun) |
1083 | { | |
1084 | maybe_initialize_fundef_copies_table (); | |
1085 | ||
97f3003f | 1086 | tree copy; |
3c98ff9b NS |
1087 | bool existed; |
1088 | tree *slot = &fundef_copies_table->get_or_insert (fun, &existed); | |
1089 | ||
1090 | if (!existed) | |
c0daf32d | 1091 | { |
3c98ff9b NS |
1092 | /* There is no cached function available, or in use. We can use |
1093 | the function directly. That the slot is now created records | |
1094 | that this function is now in use. */ | |
1095 | copy = build_tree_list (DECL_SAVED_TREE (fun), DECL_ARGUMENTS (fun)); | |
1096 | TREE_TYPE (copy) = DECL_RESULT (fun); | |
1097 | } | |
1098 | else if (*slot == NULL_TREE) | |
1099 | { | |
1100 | /* We've already used the function itself, so make a copy. */ | |
97f3003f | 1101 | copy = build_tree_list (NULL, NULL); |
97f3003f | 1102 | TREE_PURPOSE (copy) = copy_fn (fun, TREE_VALUE (copy), TREE_TYPE (copy)); |
c0daf32d PP |
1103 | } |
1104 | else | |
1105 | { | |
3c98ff9b | 1106 | /* We have a cached function available. */ |
c0daf32d | 1107 | copy = *slot; |
97f3003f | 1108 | *slot = TREE_CHAIN (copy); |
c0daf32d PP |
1109 | } |
1110 | ||
1111 | return copy; | |
1112 | } | |
1113 | ||
3c98ff9b NS |
1114 | /* Save the copy COPY of function FUN for later reuse by |
1115 | get_fundef_copy(). By construction, there will always be an entry | |
1116 | to find. */ | |
c0daf32d PP |
1117 | |
1118 | static void | |
97f3003f | 1119 | save_fundef_copy (tree fun, tree copy) |
c0daf32d | 1120 | { |
3c98ff9b | 1121 | tree *slot = fundef_copies_table->get (fun); |
97f3003f | 1122 | TREE_CHAIN (copy) = *slot; |
c0daf32d PP |
1123 | *slot = copy; |
1124 | } | |
1125 | ||
2d76680f PC |
1126 | /* We have an expression tree T that represents a call, either CALL_EXPR |
1127 | or AGGR_INIT_EXPR. Return the Nth argument. */ | |
1128 | ||
1129 | static inline tree | |
1130 | get_nth_callarg (tree t, int n) | |
1131 | { | |
1132 | switch (TREE_CODE (t)) | |
1133 | { | |
1134 | case CALL_EXPR: | |
1135 | return CALL_EXPR_ARG (t, n); | |
1136 | ||
1137 | case AGGR_INIT_EXPR: | |
1138 | return AGGR_INIT_EXPR_ARG (t, n); | |
1139 | ||
1140 | default: | |
1141 | gcc_unreachable (); | |
1142 | return NULL; | |
1143 | } | |
1144 | } | |
1145 | ||
2d76680f PC |
1146 | /* Attempt to evaluate T which represents a call to a builtin function. |
1147 | We assume here that all builtin functions evaluate to scalar types | |
1148 | represented by _CST nodes. */ | |
1149 | ||
1150 | static tree | |
5756d0f9 | 1151 | cxx_eval_builtin_function_call (const constexpr_ctx *ctx, tree t, tree fun, |
92a596e8 | 1152 | bool lval, |
2d76680f PC |
1153 | bool *non_constant_p, bool *overflow_p) |
1154 | { | |
1155 | const int nargs = call_expr_nargs (t); | |
1156 | tree *args = (tree *) alloca (nargs * sizeof (tree)); | |
1157 | tree new_call; | |
1158 | int i; | |
5756d0f9 JM |
1159 | |
1160 | /* Don't fold __builtin_constant_p within a constexpr function. */ | |
b925d25d JM |
1161 | bool bi_const_p = (DECL_FUNCTION_CODE (fun) == BUILT_IN_CONSTANT_P); |
1162 | ||
1163 | if (bi_const_p | |
5756d0f9 JM |
1164 | && current_function_decl |
1165 | && DECL_DECLARED_CONSTEXPR_P (current_function_decl)) | |
2d76680f | 1166 | { |
5756d0f9 JM |
1167 | *non_constant_p = true; |
1168 | return t; | |
2d76680f | 1169 | } |
5756d0f9 JM |
1170 | |
1171 | /* Be permissive for arguments to built-ins; __builtin_constant_p should | |
1172 | return constant false for a non-constant argument. */ | |
1173 | constexpr_ctx new_ctx = *ctx; | |
1174 | new_ctx.quiet = true; | |
1175 | bool dummy1 = false, dummy2 = false; | |
1176 | for (i = 0; i < nargs; ++i) | |
b925d25d JM |
1177 | { |
1178 | args[i] = cxx_eval_constant_expression (&new_ctx, CALL_EXPR_ARG (t, i), | |
109d2197 | 1179 | false, &dummy1, &dummy2); |
b925d25d JM |
1180 | if (bi_const_p) |
1181 | /* For __built_in_constant_p, fold all expressions with constant values | |
1182 | even if they aren't C++ constant-expressions. */ | |
1183 | args[i] = cp_fully_fold (args[i]); | |
1184 | } | |
5756d0f9 JM |
1185 | |
1186 | bool save_ffbcp = force_folding_builtin_constant_p; | |
1187 | force_folding_builtin_constant_p = true; | |
109d2197 JJ |
1188 | new_call = fold_builtin_call_array (EXPR_LOCATION (t), TREE_TYPE (t), |
1189 | CALL_EXPR_FN (t), nargs, args); | |
5756d0f9 | 1190 | force_folding_builtin_constant_p = save_ffbcp; |
109d2197 JJ |
1191 | if (new_call == NULL) |
1192 | { | |
1193 | if (!*non_constant_p && !ctx->quiet) | |
1194 | { | |
1b6fa695 ML |
1195 | /* Do not allow__builtin_unreachable in constexpr function. |
1196 | The __builtin_unreachable call with BUILTINS_LOCATION | |
1197 | comes from cp_maybe_instrument_return. */ | |
1198 | if (DECL_FUNCTION_CODE (fun) == BUILT_IN_UNREACHABLE | |
1199 | && EXPR_LOCATION (t) == BUILTINS_LOCATION) | |
84fa214d | 1200 | error ("%<constexpr%> call flows off the end of the function"); |
1b6fa695 ML |
1201 | else |
1202 | { | |
1203 | new_call = build_call_array_loc (EXPR_LOCATION (t), TREE_TYPE (t), | |
1204 | CALL_EXPR_FN (t), nargs, args); | |
1205 | error ("%q+E is not a constant expression", new_call); | |
1206 | } | |
109d2197 JJ |
1207 | } |
1208 | *non_constant_p = true; | |
1209 | return t; | |
1210 | } | |
1211 | ||
a0ab7ccd | 1212 | if (!is_constant_expression (new_call)) |
109d2197 JJ |
1213 | { |
1214 | if (!*non_constant_p && !ctx->quiet) | |
1215 | error ("%q+E is not a constant expression", new_call); | |
1216 | *non_constant_p = true; | |
1217 | return t; | |
1218 | } | |
1219 | ||
1220 | return cxx_eval_constant_expression (&new_ctx, new_call, lval, | |
1221 | non_constant_p, overflow_p); | |
2d76680f PC |
1222 | } |
1223 | ||
1224 | /* TEMP is the constant value of a temporary object of type TYPE. Adjust | |
1225 | the type of the value to match. */ | |
1226 | ||
1227 | static tree | |
1228 | adjust_temp_type (tree type, tree temp) | |
1229 | { | |
1230 | if (TREE_TYPE (temp) == type) | |
1231 | return temp; | |
1232 | /* Avoid wrapping an aggregate value in a NOP_EXPR. */ | |
1233 | if (TREE_CODE (temp) == CONSTRUCTOR) | |
1234 | return build_constructor (type, CONSTRUCTOR_ELTS (temp)); | |
1235 | gcc_assert (scalarish_type_p (type)); | |
1236 | return cp_fold_convert (type, temp); | |
1237 | } | |
1238 | ||
0146e25f PP |
1239 | /* Callback for walk_tree used by unshare_constructor. */ |
1240 | ||
1241 | static tree | |
1242 | find_constructor (tree *tp, int *walk_subtrees, void *) | |
1243 | { | |
1244 | if (TYPE_P (*tp)) | |
1245 | *walk_subtrees = 0; | |
1246 | if (TREE_CODE (*tp) == CONSTRUCTOR) | |
1247 | return *tp; | |
1248 | return NULL_TREE; | |
1249 | } | |
1250 | ||
1251 | /* If T is a CONSTRUCTOR or an expression that has a CONSTRUCTOR node as a | |
1252 | subexpression, return an unshared copy of T. Otherwise return T. */ | |
1253 | ||
1254 | static tree | |
1255 | unshare_constructor (tree t) | |
1256 | { | |
1257 | tree ctor = walk_tree (&t, find_constructor, NULL, NULL); | |
1258 | if (ctor != NULL_TREE) | |
1259 | return unshare_expr (t); | |
1260 | return t; | |
1261 | } | |
1262 | ||
2d76680f PC |
1263 | /* Subroutine of cxx_eval_call_expression. |
1264 | We are processing a call expression (either CALL_EXPR or | |
3e605b20 | 1265 | AGGR_INIT_EXPR) in the context of CTX. Evaluate |
2d76680f PC |
1266 | all arguments and bind their values to correspondings |
1267 | parameters, making up the NEW_CALL context. */ | |
1268 | ||
1269 | static void | |
3e605b20 | 1270 | cxx_bind_parameters_in_call (const constexpr_ctx *ctx, tree t, |
2d76680f | 1271 | constexpr_call *new_call, |
12d9ce19 JM |
1272 | bool *non_constant_p, bool *overflow_p, |
1273 | bool *non_constant_args) | |
2d76680f PC |
1274 | { |
1275 | const int nargs = call_expr_nargs (t); | |
1276 | tree fun = new_call->fundef->decl; | |
1277 | tree parms = DECL_ARGUMENTS (fun); | |
1278 | int i; | |
60813a46 | 1279 | tree *p = &new_call->bindings; |
2d76680f PC |
1280 | for (i = 0; i < nargs; ++i) |
1281 | { | |
1282 | tree x, arg; | |
1283 | tree type = parms ? TREE_TYPE (parms) : void_type_node; | |
2d76680f | 1284 | x = get_nth_callarg (t, i); |
3e605b20 JM |
1285 | /* For member function, the first argument is a pointer to the implied |
1286 | object. For a constructor, it might still be a dummy object, in | |
60813a46 | 1287 | which case we get the real argument from ctx. */ |
3e605b20 JM |
1288 | if (i == 0 && DECL_CONSTRUCTOR_P (fun) |
1289 | && is_dummy_object (x)) | |
1290 | { | |
1291 | x = ctx->object; | |
84dd815f | 1292 | x = build_address (x); |
3e605b20 | 1293 | } |
0e038601 | 1294 | arg = cxx_eval_constant_expression (ctx, x, /*lval=*/false, |
5a804683 | 1295 | non_constant_p, overflow_p); |
2d76680f | 1296 | /* Don't VERIFY_CONSTANT here. */ |
2b3ab879 | 1297 | if (*non_constant_p && ctx->quiet) |
2d76680f PC |
1298 | return; |
1299 | /* Just discard ellipsis args after checking their constantitude. */ | |
1300 | if (!parms) | |
1301 | continue; | |
4727d4c6 NS |
1302 | |
1303 | if (!*non_constant_p) | |
1304 | { | |
1305 | /* Make sure the binding has the same type as the parm. But | |
1306 | only for constant args. */ | |
1307 | if (TREE_CODE (type) != REFERENCE_TYPE) | |
1308 | arg = adjust_temp_type (type, arg); | |
1309 | if (!TREE_CONSTANT (arg)) | |
1310 | *non_constant_args = true; | |
1311 | *p = build_tree_list (parms, arg); | |
1312 | p = &TREE_CHAIN (*p); | |
1313 | } | |
2d76680f PC |
1314 | parms = TREE_CHAIN (parms); |
1315 | } | |
1316 | } | |
1317 | ||
1318 | /* Variables and functions to manage constexpr call expansion context. | |
1319 | These do not need to be marked for PCH or GC. */ | |
1320 | ||
1321 | /* FIXME remember and print actual constant arguments. */ | |
7de76362 | 1322 | static vec<tree> call_stack; |
2d76680f PC |
1323 | static int call_stack_tick; |
1324 | static int last_cx_error_tick; | |
1325 | ||
1326 | static bool | |
1327 | push_cx_call_context (tree call) | |
1328 | { | |
1329 | ++call_stack_tick; | |
1330 | if (!EXPR_HAS_LOCATION (call)) | |
1331 | SET_EXPR_LOCATION (call, input_location); | |
1332 | call_stack.safe_push (call); | |
1333 | if (call_stack.length () > (unsigned) max_constexpr_depth) | |
1334 | return false; | |
1335 | return true; | |
1336 | } | |
1337 | ||
1338 | static void | |
1339 | pop_cx_call_context (void) | |
1340 | { | |
1341 | ++call_stack_tick; | |
1342 | call_stack.pop (); | |
1343 | } | |
1344 | ||
1345 | vec<tree> | |
1346 | cx_error_context (void) | |
1347 | { | |
1348 | vec<tree> r = vNULL; | |
1349 | if (call_stack_tick != last_cx_error_tick | |
1350 | && !call_stack.is_empty ()) | |
1351 | r = call_stack; | |
1352 | last_cx_error_tick = call_stack_tick; | |
1353 | return r; | |
1354 | } | |
1355 | ||
44a845ca MS |
1356 | /* Evaluate a call T to a GCC internal function when possible and return |
1357 | the evaluated result or, under the control of CTX, give an error, set | |
1358 | NON_CONSTANT_P, and return the unevaluated call T otherwise. */ | |
1359 | ||
1360 | static tree | |
1361 | cxx_eval_internal_function (const constexpr_ctx *ctx, tree t, | |
1362 | bool lval, | |
1363 | bool *non_constant_p, bool *overflow_p) | |
1364 | { | |
1365 | enum tree_code opcode = ERROR_MARK; | |
1366 | ||
1367 | switch (CALL_EXPR_IFN (t)) | |
1368 | { | |
1369 | case IFN_UBSAN_NULL: | |
1370 | case IFN_UBSAN_BOUNDS: | |
1371 | case IFN_UBSAN_VPTR: | |
81fea426 | 1372 | case IFN_FALLTHROUGH: |
44a845ca MS |
1373 | return void_node; |
1374 | ||
1375 | case IFN_ADD_OVERFLOW: | |
1376 | opcode = PLUS_EXPR; | |
1377 | break; | |
1378 | case IFN_SUB_OVERFLOW: | |
1379 | opcode = MINUS_EXPR; | |
1380 | break; | |
1381 | case IFN_MUL_OVERFLOW: | |
1382 | opcode = MULT_EXPR; | |
1383 | break; | |
1384 | ||
e16f1cc7 JJ |
1385 | case IFN_LAUNDER: |
1386 | return cxx_eval_constant_expression (ctx, CALL_EXPR_ARG (t, 0), | |
1387 | false, non_constant_p, overflow_p); | |
1388 | ||
44a845ca MS |
1389 | default: |
1390 | if (!ctx->quiet) | |
1391 | error_at (EXPR_LOC_OR_LOC (t, input_location), | |
1392 | "call to internal function %qE", t); | |
1393 | *non_constant_p = true; | |
1394 | return t; | |
1395 | } | |
1396 | ||
1397 | /* Evaluate constant arguments using OPCODE and return a complex | |
1398 | number containing the result and the overflow bit. */ | |
1399 | tree arg0 = cxx_eval_constant_expression (ctx, CALL_EXPR_ARG (t, 0), lval, | |
1400 | non_constant_p, overflow_p); | |
1401 | tree arg1 = cxx_eval_constant_expression (ctx, CALL_EXPR_ARG (t, 1), lval, | |
1402 | non_constant_p, overflow_p); | |
1403 | ||
1404 | if (TREE_CODE (arg0) == INTEGER_CST && TREE_CODE (arg1) == INTEGER_CST) | |
1405 | { | |
1406 | location_t loc = EXPR_LOC_OR_LOC (t, input_location); | |
1407 | tree type = TREE_TYPE (TREE_TYPE (t)); | |
1408 | tree result = fold_binary_loc (loc, opcode, type, | |
1409 | fold_convert_loc (loc, type, arg0), | |
1410 | fold_convert_loc (loc, type, arg1)); | |
1411 | tree ovf | |
1412 | = build_int_cst (type, arith_overflowed_p (opcode, type, arg0, arg1)); | |
1413 | /* Reset TREE_OVERFLOW to avoid warnings for the overflow. */ | |
1414 | if (TREE_OVERFLOW (result)) | |
1415 | TREE_OVERFLOW (result) = 0; | |
1416 | ||
1417 | return build_complex (TREE_TYPE (t), result, ovf); | |
1418 | } | |
1419 | ||
1420 | *non_constant_p = true; | |
1421 | return t; | |
1422 | } | |
1423 | ||
ecc57615 JM |
1424 | /* Clean CONSTRUCTOR_NO_IMPLICIT_ZERO from CTOR and its sub-aggregates. */ |
1425 | ||
1426 | static void | |
1427 | clear_no_implicit_zero (tree ctor) | |
1428 | { | |
1429 | if (CONSTRUCTOR_NO_IMPLICIT_ZERO (ctor)) | |
1430 | { | |
1431 | CONSTRUCTOR_NO_IMPLICIT_ZERO (ctor) = false; | |
1432 | tree elt; unsigned HOST_WIDE_INT idx; | |
1433 | FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), idx, elt) | |
1434 | if (TREE_CODE (elt) == CONSTRUCTOR) | |
1435 | clear_no_implicit_zero (elt); | |
1436 | } | |
1437 | } | |
1438 | ||
2d76680f PC |
1439 | /* Subroutine of cxx_eval_constant_expression. |
1440 | Evaluate the call expression tree T in the context of OLD_CALL expression | |
1441 | evaluation. */ | |
1442 | ||
1443 | static tree | |
3e605b20 | 1444 | cxx_eval_call_expression (const constexpr_ctx *ctx, tree t, |
92a596e8 | 1445 | bool lval, |
2d76680f PC |
1446 | bool *non_constant_p, bool *overflow_p) |
1447 | { | |
1448 | location_t loc = EXPR_LOC_OR_LOC (t, input_location); | |
1449 | tree fun = get_function_named_in_call (t); | |
2d76680f | 1450 | constexpr_call new_call = { NULL, NULL, NULL, 0 }; |
2d76680f PC |
1451 | bool depth_ok; |
1452 | ||
0b274c17 | 1453 | if (fun == NULL_TREE) |
44a845ca MS |
1454 | return cxx_eval_internal_function (ctx, t, lval, |
1455 | non_constant_p, overflow_p); | |
0b274c17 | 1456 | |
2d76680f PC |
1457 | if (TREE_CODE (fun) != FUNCTION_DECL) |
1458 | { | |
1459 | /* Might be a constexpr function pointer. */ | |
2b3ab879 | 1460 | fun = cxx_eval_constant_expression (ctx, fun, |
92a596e8 | 1461 | /*lval*/false, non_constant_p, |
5a804683 | 1462 | overflow_p); |
2d76680f PC |
1463 | STRIP_NOPS (fun); |
1464 | if (TREE_CODE (fun) == ADDR_EXPR) | |
1465 | fun = TREE_OPERAND (fun, 0); | |
1466 | } | |
1467 | if (TREE_CODE (fun) != FUNCTION_DECL) | |
1468 | { | |
2b3ab879 | 1469 | if (!ctx->quiet && !*non_constant_p) |
84fa214d | 1470 | error_at (loc, "expression %qE does not designate a %<constexpr%> " |
2d76680f PC |
1471 | "function", fun); |
1472 | *non_constant_p = true; | |
1473 | return t; | |
1474 | } | |
1475 | if (DECL_CLONED_FUNCTION_P (fun)) | |
1476 | fun = DECL_CLONED_FUNCTION (fun); | |
0b274c17 MP |
1477 | |
1478 | if (is_ubsan_builtin_p (fun)) | |
1479 | return void_node; | |
1480 | ||
2d76680f | 1481 | if (is_builtin_fn (fun)) |
5756d0f9 | 1482 | return cxx_eval_builtin_function_call (ctx, t, fun, |
92a596e8 | 1483 | lval, non_constant_p, overflow_p); |
2d76680f PC |
1484 | if (!DECL_DECLARED_CONSTEXPR_P (fun)) |
1485 | { | |
2b3ab879 | 1486 | if (!ctx->quiet) |
2d76680f | 1487 | { |
11399477 | 1488 | if (!lambda_static_thunk_p (fun)) |
84fa214d | 1489 | error_at (loc, "call to non-%<constexpr%> function %qD", fun); |
2d76680f PC |
1490 | explain_invalid_constexpr_fn (fun); |
1491 | } | |
1492 | *non_constant_p = true; | |
1493 | return t; | |
1494 | } | |
1495 | ||
86461cad JM |
1496 | constexpr_ctx new_ctx = *ctx; |
1497 | if (DECL_CONSTRUCTOR_P (fun) && !ctx->object | |
1498 | && TREE_CODE (t) == AGGR_INIT_EXPR) | |
1499 | { | |
1500 | /* We want to have an initialization target for an AGGR_INIT_EXPR. | |
1501 | If we don't already have one in CTX, use the AGGR_INIT_EXPR_SLOT. */ | |
1502 | new_ctx.object = AGGR_INIT_EXPR_SLOT (t); | |
1503 | tree ctor = new_ctx.ctor = build_constructor (DECL_CONTEXT (fun), NULL); | |
1504 | CONSTRUCTOR_NO_IMPLICIT_ZERO (ctor) = true; | |
1505 | ctx->values->put (new_ctx.object, ctor); | |
1506 | ctx = &new_ctx; | |
1507 | } | |
1508 | ||
2d76680f PC |
1509 | /* Shortcut trivial constructor/op=. */ |
1510 | if (trivial_fn_p (fun)) | |
1511 | { | |
86461cad | 1512 | tree init = NULL_TREE; |
2d76680f | 1513 | if (call_expr_nargs (t) == 2) |
86461cad | 1514 | init = convert_from_reference (get_nth_callarg (t, 1)); |
2d76680f PC |
1515 | else if (TREE_CODE (t) == AGGR_INIT_EXPR |
1516 | && AGGR_INIT_ZERO_FIRST (t)) | |
86461cad JM |
1517 | init = build_zero_init (DECL_CONTEXT (fun), NULL_TREE, false); |
1518 | if (init) | |
1519 | { | |
1520 | tree op = get_nth_callarg (t, 0); | |
1521 | if (is_dummy_object (op)) | |
1522 | op = ctx->object; | |
1523 | else | |
1524 | op = build1 (INDIRECT_REF, TREE_TYPE (TREE_TYPE (op)), op); | |
1525 | tree set = build2 (MODIFY_EXPR, TREE_TYPE (op), op, init); | |
c8816908 JM |
1526 | new_ctx.call = &new_call; |
1527 | return cxx_eval_constant_expression (&new_ctx, set, lval, | |
86461cad JM |
1528 | non_constant_p, overflow_p); |
1529 | } | |
2d76680f PC |
1530 | } |
1531 | ||
81371eff JM |
1532 | /* We can't defer instantiating the function any longer. */ |
1533 | if (!DECL_INITIAL (fun) | |
1534 | && DECL_TEMPLOID_INSTANTIATION (fun)) | |
1535 | { | |
f065303f JM |
1536 | location_t save_loc = input_location; |
1537 | input_location = loc; | |
81371eff JM |
1538 | ++function_depth; |
1539 | instantiate_decl (fun, /*defer_ok*/false, /*expl_inst*/false); | |
1540 | --function_depth; | |
f065303f | 1541 | input_location = save_loc; |
81371eff JM |
1542 | } |
1543 | ||
2d76680f | 1544 | /* If in direct recursive call, optimize definition search. */ |
c8816908 | 1545 | if (ctx && ctx->call && ctx->call->fundef && ctx->call->fundef->decl == fun) |
3e605b20 | 1546 | new_call.fundef = ctx->call->fundef; |
2d76680f PC |
1547 | else |
1548 | { | |
1549 | new_call.fundef = retrieve_constexpr_fundef (fun); | |
4ddcdbf9 JM |
1550 | if (new_call.fundef == NULL || new_call.fundef->body == NULL |
1551 | || fun == current_function_decl) | |
2d76680f | 1552 | { |
2b3ab879 | 1553 | if (!ctx->quiet) |
2d76680f | 1554 | { |
4ddcdbf9 JM |
1555 | /* We need to check for current_function_decl here in case we're |
1556 | being called during cp_fold_function, because at that point | |
1557 | DECL_INITIAL is set properly and we have a fundef but we | |
1558 | haven't lowered invisirefs yet (c++/70344). */ | |
1559 | if (DECL_INITIAL (fun) == error_mark_node | |
1560 | || fun == current_function_decl) | |
ddd6d421 JM |
1561 | error_at (loc, "%qD called in a constant expression before its " |
1562 | "definition is complete", fun); | |
1563 | else if (DECL_INITIAL (fun)) | |
2d76680f | 1564 | { |
98e5a19a JM |
1565 | /* The definition of fun was somehow unsuitable. But pretend |
1566 | that lambda static thunks don't exist. */ | |
1567 | if (!lambda_static_thunk_p (fun)) | |
1568 | error_at (loc, "%qD called in a constant expression", fun); | |
2d76680f PC |
1569 | explain_invalid_constexpr_fn (fun); |
1570 | } | |
1571 | else | |
1572 | error_at (loc, "%qD used before its definition", fun); | |
1573 | } | |
1574 | *non_constant_p = true; | |
1575 | return t; | |
1576 | } | |
1577 | } | |
60813a46 | 1578 | |
12d9ce19 | 1579 | bool non_constant_args = false; |
3e605b20 | 1580 | cxx_bind_parameters_in_call (ctx, t, &new_call, |
12d9ce19 | 1581 | non_constant_p, overflow_p, &non_constant_args); |
2d76680f PC |
1582 | if (*non_constant_p) |
1583 | return t; | |
1584 | ||
1585 | depth_ok = push_cx_call_context (t); | |
1586 | ||
12d9ce19 | 1587 | tree result = NULL_TREE; |
2d76680f | 1588 | |
12d9ce19 | 1589 | constexpr_call *entry = NULL; |
4a58d2fe | 1590 | if (depth_ok && !non_constant_args && ctx->strict) |
2d76680f | 1591 | { |
12d9ce19 JM |
1592 | new_call.hash = iterative_hash_template_arg |
1593 | (new_call.bindings, constexpr_fundef_hasher::hash (new_call.fundef)); | |
1594 | ||
1595 | /* If we have seen this call before, we are done. */ | |
1596 | maybe_initialize_constexpr_call_table (); | |
1597 | constexpr_call **slot | |
1598 | = constexpr_call_table->find_slot (&new_call, INSERT); | |
1599 | entry = *slot; | |
1600 | if (entry == NULL) | |
1601 | { | |
1602 | /* We need to keep a pointer to the entry, not just the slot, as the | |
1603 | slot can move in the call to cxx_eval_builtin_function_call. */ | |
1604 | *slot = entry = ggc_alloc<constexpr_call> (); | |
1605 | *entry = new_call; | |
1606 | } | |
4727d4c6 | 1607 | /* Calls that are in progress have their result set to NULL, |
12d9ce19 JM |
1608 | so that we can detect circular dependencies. */ |
1609 | else if (entry->result == NULL) | |
1610 | { | |
1611 | if (!ctx->quiet) | |
1612 | error ("call has circular dependency"); | |
1613 | *non_constant_p = true; | |
1614 | entry->result = result = error_mark_node; | |
1615 | } | |
1616 | else | |
1617 | result = entry->result; | |
2d76680f PC |
1618 | } |
1619 | ||
1620 | if (!depth_ok) | |
1621 | { | |
2b3ab879 | 1622 | if (!ctx->quiet) |
84fa214d | 1623 | error ("%<constexpr%> evaluation depth exceeds maximum of %d (use " |
2d76680f PC |
1624 | "-fconstexpr-depth= to increase the maximum)", |
1625 | max_constexpr_depth); | |
1626 | *non_constant_p = true; | |
12d9ce19 | 1627 | result = error_mark_node; |
2d76680f PC |
1628 | } |
1629 | else | |
1630 | { | |
de54de93 JM |
1631 | if (result && result != error_mark_node) |
1632 | /* OK */; | |
1633 | else if (!DECL_SAVED_TREE (fun)) | |
1634 | { | |
1635 | /* When at_eof >= 2, cgraph has started throwing away | |
1636 | DECL_SAVED_TREE, so fail quietly. FIXME we get here because of | |
1637 | late code generation for VEC_INIT_EXPR, which needs to be | |
1638 | completely reconsidered. */ | |
1639 | gcc_assert (at_eof >= 2 && ctx->quiet); | |
1640 | *non_constant_p = true; | |
1641 | } | |
1642 | else | |
3e605b20 | 1643 | { |
c0daf32d | 1644 | tree body, parms, res; |
0567dcd2 | 1645 | |
c0daf32d | 1646 | /* Reuse or create a new unshared copy of this function's body. */ |
97f3003f JM |
1647 | tree copy = get_fundef_copy (fun); |
1648 | body = TREE_PURPOSE (copy); | |
1649 | parms = TREE_VALUE (copy); | |
1650 | res = TREE_TYPE (copy); | |
0567dcd2 MP |
1651 | |
1652 | /* Associate the bindings with the remapped parms. */ | |
1653 | tree bound = new_call.bindings; | |
1654 | tree remapped = parms; | |
1655 | while (bound) | |
60813a46 | 1656 | { |
0567dcd2 MP |
1657 | tree oparm = TREE_PURPOSE (bound); |
1658 | tree arg = TREE_VALUE (bound); | |
1659 | gcc_assert (DECL_NAME (remapped) == DECL_NAME (oparm)); | |
7f0e23e9 | 1660 | /* Don't share a CONSTRUCTOR that might be changed. */ |
0146e25f | 1661 | arg = unshare_constructor (arg); |
0567dcd2 MP |
1662 | ctx->values->put (remapped, arg); |
1663 | bound = TREE_CHAIN (bound); | |
1664 | remapped = DECL_CHAIN (remapped); | |
60813a46 | 1665 | } |
0567dcd2 MP |
1666 | /* Add the RESULT_DECL to the values map, too. */ |
1667 | tree slot = NULL_TREE; | |
1668 | if (DECL_BY_REFERENCE (res)) | |
60813a46 | 1669 | { |
0567dcd2 MP |
1670 | slot = AGGR_INIT_EXPR_SLOT (t); |
1671 | tree addr = build_address (slot); | |
1672 | addr = build_nop (TREE_TYPE (res), addr); | |
1673 | ctx->values->put (res, addr); | |
1674 | ctx->values->put (slot, NULL_TREE); | |
1675 | } | |
1676 | else | |
1677 | ctx->values->put (res, NULL_TREE); | |
60813a46 | 1678 | |
c0daf32d PP |
1679 | /* Track the callee's evaluated SAVE_EXPRs so that we can forget |
1680 | their values after the call. */ | |
1681 | constexpr_ctx ctx_with_save_exprs = *ctx; | |
1682 | hash_set<tree> save_exprs; | |
1683 | ctx_with_save_exprs.save_exprs = &save_exprs; | |
1e163090 | 1684 | ctx_with_save_exprs.call = &new_call; |
c0daf32d | 1685 | |
0567dcd2 | 1686 | tree jump_target = NULL_TREE; |
c0daf32d | 1687 | cxx_eval_constant_expression (&ctx_with_save_exprs, body, |
0567dcd2 MP |
1688 | lval, non_constant_p, overflow_p, |
1689 | &jump_target); | |
60813a46 | 1690 | |
0567dcd2 MP |
1691 | if (DECL_CONSTRUCTOR_P (fun)) |
1692 | /* This can be null for a subobject constructor call, in | |
1693 | which case what we care about is the initialization | |
1694 | side-effects rather than the value. We could get at the | |
1695 | value by evaluating *this, but we don't bother; there's | |
1696 | no need to put such a call in the hash table. */ | |
1697 | result = lval ? ctx->object : ctx->ctor; | |
1698 | else if (VOID_TYPE_P (TREE_TYPE (res))) | |
1699 | result = void_node; | |
1700 | else | |
1701 | { | |
1702 | result = *ctx->values->get (slot ? slot : res); | |
1703 | if (result == NULL_TREE && !*non_constant_p) | |
60813a46 | 1704 | { |
0567dcd2 | 1705 | if (!ctx->quiet) |
84fa214d | 1706 | error ("%<constexpr%> call flows off the end " |
0567dcd2 MP |
1707 | "of the function"); |
1708 | *non_constant_p = true; | |
60813a46 | 1709 | } |
60813a46 | 1710 | } |
0567dcd2 | 1711 | |
c0daf32d PP |
1712 | /* Forget the saved values of the callee's SAVE_EXPRs. */ |
1713 | for (hash_set<tree>::iterator iter = save_exprs.begin(); | |
1714 | iter != save_exprs.end(); ++iter) | |
1715 | ctx_with_save_exprs.values->remove (*iter); | |
1716 | ||
0567dcd2 MP |
1717 | /* Remove the parms/result from the values map. Is it worth |
1718 | bothering to do this when the map itself is only live for | |
1719 | one constexpr evaluation? If so, maybe also clear out | |
1720 | other vars from call, maybe in BIND_EXPR handling? */ | |
1721 | ctx->values->remove (res); | |
1722 | if (slot) | |
1723 | ctx->values->remove (slot); | |
1724 | for (tree parm = parms; parm; parm = TREE_CHAIN (parm)) | |
1725 | ctx->values->remove (parm); | |
c0daf32d PP |
1726 | |
1727 | /* Make the unshared function copy we used available for re-use. */ | |
1728 | save_fundef_copy (fun, copy); | |
3e605b20 | 1729 | } |
60813a46 | 1730 | |
2d76680f PC |
1731 | if (result == error_mark_node) |
1732 | *non_constant_p = true; | |
52228180 | 1733 | if (*non_constant_p || *overflow_p) |
12d9ce19 | 1734 | result = error_mark_node; |
0567dcd2 | 1735 | else if (!result) |
60813a46 | 1736 | result = void_node; |
12d9ce19 JM |
1737 | if (entry) |
1738 | entry->result = result; | |
2d76680f PC |
1739 | } |
1740 | ||
f64e0c02 JM |
1741 | /* The result of a constexpr function must be completely initialized. */ |
1742 | if (TREE_CODE (result) == CONSTRUCTOR) | |
ecc57615 | 1743 | clear_no_implicit_zero (result); |
f64e0c02 | 1744 | |
2d76680f | 1745 | pop_cx_call_context (); |
0146e25f | 1746 | return unshare_constructor (result); |
2d76680f PC |
1747 | } |
1748 | ||
1749 | /* FIXME speed this up, it's taking 16% of compile time on sieve testcase. */ | |
1750 | ||
1751 | bool | |
1752 | reduced_constant_expression_p (tree t) | |
1753 | { | |
1754 | switch (TREE_CODE (t)) | |
1755 | { | |
1756 | case PTRMEM_CST: | |
1757 | /* Even if we can't lower this yet, it's constant. */ | |
1758 | return true; | |
1759 | ||
1760 | case CONSTRUCTOR: | |
1761 | /* And we need to handle PTRMEM_CST wrapped in a CONSTRUCTOR. */ | |
7368cfa4 JM |
1762 | tree idx, val, field; unsigned HOST_WIDE_INT i; |
1763 | if (CONSTRUCTOR_NO_IMPLICIT_ZERO (t)) | |
1764 | field = next_initializable_field (TYPE_FIELDS (TREE_TYPE (t))); | |
1765 | else | |
1766 | field = NULL_TREE; | |
1767 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (t), i, idx, val) | |
125db6a1 | 1768 | { |
7368cfa4 | 1769 | if (!val) |
125db6a1 JM |
1770 | /* We're in the middle of initializing this element. */ |
1771 | return false; | |
7368cfa4 | 1772 | if (!reduced_constant_expression_p (val)) |
125db6a1 | 1773 | return false; |
7368cfa4 JM |
1774 | if (field) |
1775 | { | |
1776 | if (idx != field) | |
1777 | return false; | |
1778 | field = next_initializable_field (DECL_CHAIN (field)); | |
1779 | } | |
125db6a1 | 1780 | } |
7368cfa4 JM |
1781 | if (field) |
1782 | return false; | |
1783 | else if (CONSTRUCTOR_NO_IMPLICIT_ZERO (t)) | |
1784 | /* All the fields are initialized. */ | |
1785 | CONSTRUCTOR_NO_IMPLICIT_ZERO (t) = false; | |
2d76680f PC |
1786 | return true; |
1787 | ||
1788 | default: | |
1789 | /* FIXME are we calling this too much? */ | |
1790 | return initializer_constant_valid_p (t, TREE_TYPE (t)) != NULL_TREE; | |
1791 | } | |
1792 | } | |
1793 | ||
1794 | /* Some expressions may have constant operands but are not constant | |
1795 | themselves, such as 1/0. Call this function (or rather, the macro | |
1796 | following it) to check for that condition. | |
1797 | ||
1798 | We only call this in places that require an arithmetic constant, not in | |
1799 | places where we might have a non-constant expression that can be a | |
1800 | component of a constant expression, such as the address of a constexpr | |
1801 | variable that might be dereferenced later. */ | |
1802 | ||
1803 | static bool | |
1804 | verify_constant (tree t, bool allow_non_constant, bool *non_constant_p, | |
1805 | bool *overflow_p) | |
1806 | { | |
1807 | if (!*non_constant_p && !reduced_constant_expression_p (t)) | |
1808 | { | |
1809 | if (!allow_non_constant) | |
1810 | error ("%q+E is not a constant expression", t); | |
1811 | *non_constant_p = true; | |
1812 | } | |
1813 | if (TREE_OVERFLOW_P (t)) | |
1814 | { | |
1815 | if (!allow_non_constant) | |
1816 | { | |
1817 | permerror (input_location, "overflow in constant expression"); | |
1818 | /* If we're being permissive (and are in an enforcing | |
1819 | context), ignore the overflow. */ | |
1820 | if (flag_permissive) | |
1821 | return *non_constant_p; | |
1822 | } | |
1823 | *overflow_p = true; | |
1824 | } | |
1825 | return *non_constant_p; | |
1826 | } | |
1827 | ||
253a921b MP |
1828 | /* Check whether the shift operation with code CODE and type TYPE on LHS |
1829 | and RHS is undefined. If it is, give an error with an explanation, | |
1830 | and return true; return false otherwise. */ | |
1831 | ||
1832 | static bool | |
1833 | cxx_eval_check_shift_p (location_t loc, const constexpr_ctx *ctx, | |
1834 | enum tree_code code, tree type, tree lhs, tree rhs) | |
1835 | { | |
1836 | if ((code != LSHIFT_EXPR && code != RSHIFT_EXPR) | |
1837 | || TREE_CODE (lhs) != INTEGER_CST | |
1838 | || TREE_CODE (rhs) != INTEGER_CST) | |
1839 | return false; | |
1840 | ||
1841 | tree lhstype = TREE_TYPE (lhs); | |
1842 | unsigned HOST_WIDE_INT uprec = TYPE_PRECISION (TREE_TYPE (lhs)); | |
1843 | ||
1844 | /* [expr.shift] The behavior is undefined if the right operand | |
1845 | is negative, or greater than or equal to the length in bits | |
1846 | of the promoted left operand. */ | |
1847 | if (tree_int_cst_sgn (rhs) == -1) | |
1848 | { | |
1849 | if (!ctx->quiet) | |
5342156c MP |
1850 | permerror (loc, "right operand of shift expression %q+E is negative", |
1851 | build2_loc (loc, code, type, lhs, rhs)); | |
1852 | return (!flag_permissive || ctx->quiet); | |
253a921b MP |
1853 | } |
1854 | if (compare_tree_int (rhs, uprec) >= 0) | |
1855 | { | |
1856 | if (!ctx->quiet) | |
5342156c MP |
1857 | permerror (loc, "right operand of shift expression %q+E is >= than " |
1858 | "the precision of the left operand", | |
1859 | build2_loc (loc, code, type, lhs, rhs)); | |
1860 | return (!flag_permissive || ctx->quiet); | |
253a921b MP |
1861 | } |
1862 | ||
1863 | /* The value of E1 << E2 is E1 left-shifted E2 bit positions; [...] | |
1864 | if E1 has a signed type and non-negative value, and E1x2^E2 is | |
1865 | representable in the corresponding unsigned type of the result type, | |
1866 | then that value, converted to the result type, is the resulting value; | |
1867 | otherwise, the behavior is undefined. */ | |
1868 | if (code == LSHIFT_EXPR && !TYPE_UNSIGNED (lhstype) | |
1869 | && (cxx_dialect >= cxx11)) | |
1870 | { | |
1871 | if (tree_int_cst_sgn (lhs) == -1) | |
1872 | { | |
1873 | if (!ctx->quiet) | |
5342156c MP |
1874 | permerror (loc, |
1875 | "left operand of shift expression %q+E is negative", | |
1876 | build2_loc (loc, code, type, lhs, rhs)); | |
1877 | return (!flag_permissive || ctx->quiet); | |
253a921b MP |
1878 | } |
1879 | /* For signed x << y the following: | |
1880 | (unsigned) x >> ((prec (lhs) - 1) - y) | |
1881 | if > 1, is undefined. The right-hand side of this formula | |
1882 | is the highest bit of the LHS that can be set (starting from 0), | |
1883 | so that the shift doesn't overflow. We then right-shift the LHS | |
1884 | to see whether any other bit is set making the original shift | |
1885 | undefined -- the result is not representable in the corresponding | |
1886 | unsigned type. */ | |
1887 | tree t = build_int_cst (unsigned_type_node, uprec - 1); | |
1888 | t = fold_build2 (MINUS_EXPR, unsigned_type_node, t, rhs); | |
1889 | tree ulhs = fold_convert (unsigned_type_for (lhstype), lhs); | |
1890 | t = fold_build2 (RSHIFT_EXPR, TREE_TYPE (ulhs), ulhs, t); | |
1891 | if (tree_int_cst_lt (integer_one_node, t)) | |
1892 | { | |
1893 | if (!ctx->quiet) | |
5342156c MP |
1894 | permerror (loc, "shift expression %q+E overflows", |
1895 | build2_loc (loc, code, type, lhs, rhs)); | |
1896 | return (!flag_permissive || ctx->quiet); | |
253a921b MP |
1897 | } |
1898 | } | |
1899 | return false; | |
1900 | } | |
1901 | ||
2d76680f PC |
1902 | /* Subroutine of cxx_eval_constant_expression. |
1903 | Attempt to reduce the unary expression tree T to a compile time value. | |
1904 | If successful, return the value. Otherwise issue a diagnostic | |
1905 | and return error_mark_node. */ | |
1906 | ||
1907 | static tree | |
3e605b20 | 1908 | cxx_eval_unary_expression (const constexpr_ctx *ctx, tree t, |
12d9ce19 | 1909 | bool /*lval*/, |
2d76680f PC |
1910 | bool *non_constant_p, bool *overflow_p) |
1911 | { | |
1912 | tree r; | |
1913 | tree orig_arg = TREE_OPERAND (t, 0); | |
12d9ce19 JM |
1914 | tree arg = cxx_eval_constant_expression (ctx, orig_arg, /*lval*/false, |
1915 | non_constant_p, overflow_p); | |
2d76680f | 1916 | VERIFY_CONSTANT (arg); |
f899317e JM |
1917 | location_t loc = EXPR_LOCATION (t); |
1918 | enum tree_code code = TREE_CODE (t); | |
1919 | tree type = TREE_TYPE (t); | |
1920 | r = fold_unary_loc (loc, code, type, arg); | |
1921 | if (r == NULL_TREE) | |
1922 | { | |
1923 | if (arg == orig_arg) | |
1924 | r = t; | |
1925 | else | |
1926 | r = build1_loc (loc, code, type, arg); | |
1927 | } | |
2d76680f PC |
1928 | VERIFY_CONSTANT (r); |
1929 | return r; | |
1930 | } | |
1931 | ||
ea8661cd JJ |
1932 | /* Helper function for cxx_eval_binary_expression. Try to optimize |
1933 | original POINTER_PLUS_EXPR T, LHS p+ RHS, return NULL_TREE if the | |
1934 | generic folding should be used. */ | |
1935 | ||
1936 | static tree | |
1937 | cxx_fold_pointer_plus_expression (const constexpr_ctx *ctx, tree t, | |
1938 | tree lhs, tree rhs, bool *non_constant_p, | |
1939 | bool *overflow_p) | |
1940 | { | |
1941 | STRIP_NOPS (lhs); | |
1942 | if (TREE_CODE (lhs) != ADDR_EXPR) | |
1943 | return NULL_TREE; | |
1944 | ||
1945 | lhs = TREE_OPERAND (lhs, 0); | |
1946 | ||
1947 | /* &A[i] p+ j => &A[i + j] */ | |
1948 | if (TREE_CODE (lhs) == ARRAY_REF | |
1949 | && TREE_CODE (TREE_OPERAND (lhs, 1)) == INTEGER_CST | |
1950 | && TREE_CODE (rhs) == INTEGER_CST | |
1951 | && TYPE_SIZE_UNIT (TREE_TYPE (lhs)) | |
1952 | && TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (lhs))) == INTEGER_CST) | |
1953 | { | |
1954 | tree orig_type = TREE_TYPE (t); | |
1955 | location_t loc = EXPR_LOCATION (t); | |
1956 | tree type = TREE_TYPE (lhs); | |
1957 | ||
1958 | t = fold_convert_loc (loc, ssizetype, TREE_OPERAND (lhs, 1)); | |
1959 | tree nelts = array_type_nelts_top (TREE_TYPE (TREE_OPERAND (lhs, 0))); | |
1960 | nelts = cxx_eval_constant_expression (ctx, nelts, false, non_constant_p, | |
1961 | overflow_p); | |
1962 | if (*non_constant_p) | |
1963 | return NULL_TREE; | |
1964 | /* Don't fold an out-of-bound access. */ | |
1965 | if (!tree_int_cst_le (t, nelts)) | |
1966 | return NULL_TREE; | |
1967 | rhs = cp_fold_convert (ssizetype, rhs); | |
1968 | /* Don't fold if rhs can't be divided exactly by TYPE_SIZE_UNIT. | |
1969 | constexpr int A[1]; ... (char *)&A[0] + 1 */ | |
1970 | if (!integer_zerop (fold_build2_loc (loc, TRUNC_MOD_EXPR, sizetype, | |
1971 | rhs, TYPE_SIZE_UNIT (type)))) | |
1972 | return NULL_TREE; | |
1973 | /* Make sure to treat the second operand of POINTER_PLUS_EXPR | |
1974 | as signed. */ | |
1975 | rhs = fold_build2_loc (loc, EXACT_DIV_EXPR, ssizetype, rhs, | |
1976 | TYPE_SIZE_UNIT (type)); | |
1977 | t = size_binop_loc (loc, PLUS_EXPR, rhs, t); | |
1978 | t = build4_loc (loc, ARRAY_REF, type, TREE_OPERAND (lhs, 0), | |
1979 | t, NULL_TREE, NULL_TREE); | |
1980 | t = cp_build_addr_expr (t, tf_warning_or_error); | |
1981 | t = cp_fold_convert (orig_type, t); | |
1982 | return cxx_eval_constant_expression (ctx, t, /*lval*/false, | |
1983 | non_constant_p, overflow_p); | |
1984 | } | |
1985 | ||
1986 | return NULL_TREE; | |
1987 | } | |
1988 | ||
2d76680f PC |
1989 | /* Subroutine of cxx_eval_constant_expression. |
1990 | Like cxx_eval_unary_expression, except for binary expressions. */ | |
1991 | ||
1992 | static tree | |
3e605b20 | 1993 | cxx_eval_binary_expression (const constexpr_ctx *ctx, tree t, |
12d9ce19 | 1994 | bool /*lval*/, |
2d76680f PC |
1995 | bool *non_constant_p, bool *overflow_p) |
1996 | { | |
618d6c1c | 1997 | tree r = NULL_TREE; |
2d76680f PC |
1998 | tree orig_lhs = TREE_OPERAND (t, 0); |
1999 | tree orig_rhs = TREE_OPERAND (t, 1); | |
2000 | tree lhs, rhs; | |
12d9ce19 | 2001 | lhs = cxx_eval_constant_expression (ctx, orig_lhs, /*lval*/false, |
5a804683 | 2002 | non_constant_p, overflow_p); |
c8a66fc9 JM |
2003 | /* Don't VERIFY_CONSTANT here, it's unnecessary and will break pointer |
2004 | subtraction. */ | |
2005 | if (*non_constant_p) | |
2006 | return t; | |
12d9ce19 | 2007 | rhs = cxx_eval_constant_expression (ctx, orig_rhs, /*lval*/false, |
5a804683 | 2008 | non_constant_p, overflow_p); |
c8a66fc9 JM |
2009 | if (*non_constant_p) |
2010 | return t; | |
f899317e JM |
2011 | |
2012 | location_t loc = EXPR_LOCATION (t); | |
2013 | enum tree_code code = TREE_CODE (t); | |
2014 | tree type = TREE_TYPE (t); | |
618d6c1c PP |
2015 | |
2016 | if (code == EQ_EXPR || code == NE_EXPR) | |
2017 | { | |
2018 | bool is_code_eq = (code == EQ_EXPR); | |
2019 | ||
2020 | if (TREE_CODE (lhs) == PTRMEM_CST | |
2021 | && TREE_CODE (rhs) == PTRMEM_CST) | |
2022 | r = constant_boolean_node (cp_tree_equal (lhs, rhs) == is_code_eq, | |
2023 | type); | |
2024 | else if ((TREE_CODE (lhs) == PTRMEM_CST | |
2025 | || TREE_CODE (rhs) == PTRMEM_CST) | |
2026 | && (null_member_pointer_value_p (lhs) | |
2027 | || null_member_pointer_value_p (rhs))) | |
2028 | r = constant_boolean_node (!is_code_eq, type); | |
dd5dda56 JM |
2029 | else if (TREE_CODE (lhs) == PTRMEM_CST) |
2030 | lhs = cplus_expand_constant (lhs); | |
2031 | else if (TREE_CODE (rhs) == PTRMEM_CST) | |
2032 | rhs = cplus_expand_constant (rhs); | |
618d6c1c | 2033 | } |
8bada5cd MS |
2034 | if (code == POINTER_PLUS_EXPR && !*non_constant_p |
2035 | && integer_zerop (lhs) && !integer_zerop (rhs)) | |
2036 | { | |
2037 | if (!ctx->quiet) | |
2038 | error ("arithmetic involving a null pointer in %qE", lhs); | |
2039 | return t; | |
2040 | } | |
ea8661cd JJ |
2041 | else if (code == POINTER_PLUS_EXPR) |
2042 | r = cxx_fold_pointer_plus_expression (ctx, t, lhs, rhs, non_constant_p, | |
2043 | overflow_p); | |
618d6c1c PP |
2044 | |
2045 | if (r == NULL_TREE) | |
2046 | r = fold_binary_loc (loc, code, type, lhs, rhs); | |
2047 | ||
f899317e JM |
2048 | if (r == NULL_TREE) |
2049 | { | |
2050 | if (lhs == orig_lhs && rhs == orig_rhs) | |
2051 | r = t; | |
2052 | else | |
2053 | r = build2_loc (loc, code, type, lhs, rhs); | |
2054 | } | |
253a921b MP |
2055 | else if (cxx_eval_check_shift_p (loc, ctx, code, type, lhs, rhs)) |
2056 | *non_constant_p = true; | |
c8a66fc9 JM |
2057 | /* Don't VERIFY_CONSTANT if this might be dealing with a pointer to |
2058 | a local array in a constexpr function. */ | |
2059 | bool ptr = POINTER_TYPE_P (TREE_TYPE (lhs)); | |
caee690e | 2060 | if (!ptr) |
134efa82 | 2061 | VERIFY_CONSTANT (r); |
2d76680f PC |
2062 | return r; |
2063 | } | |
2064 | ||
2065 | /* Subroutine of cxx_eval_constant_expression. | |
2066 | Attempt to evaluate condition expressions. Dead branches are not | |
2067 | looked into. */ | |
2068 | ||
2069 | static tree | |
3e605b20 | 2070 | cxx_eval_conditional_expression (const constexpr_ctx *ctx, tree t, |
92a596e8 | 2071 | bool lval, |
56632b27 JM |
2072 | bool *non_constant_p, bool *overflow_p, |
2073 | tree *jump_target) | |
2d76680f | 2074 | { |
3e605b20 | 2075 | tree val = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), |
12d9ce19 | 2076 | /*lval*/false, |
5a804683 | 2077 | non_constant_p, overflow_p); |
2d76680f PC |
2078 | VERIFY_CONSTANT (val); |
2079 | /* Don't VERIFY_CONSTANT the other operands. */ | |
2080 | if (integer_zerop (val)) | |
3e605b20 | 2081 | return cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 2), |
92a596e8 | 2082 | lval, |
56632b27 JM |
2083 | non_constant_p, overflow_p, |
2084 | jump_target); | |
3e605b20 | 2085 | return cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), |
92a596e8 | 2086 | lval, |
56632b27 JM |
2087 | non_constant_p, overflow_p, |
2088 | jump_target); | |
2d76680f PC |
2089 | } |
2090 | ||
f370e36d JJ |
2091 | /* Subroutine of cxx_eval_constant_expression. |
2092 | Attempt to evaluate vector condition expressions. Unlike | |
2093 | cxx_eval_conditional_expression, VEC_COND_EXPR acts like a normal | |
2094 | ternary arithmetics operation, where all 3 arguments have to be | |
2095 | evaluated as constants and then folding computes the result from | |
2096 | them. */ | |
2097 | ||
2098 | static tree | |
2099 | cxx_eval_vector_conditional_expression (const constexpr_ctx *ctx, tree t, | |
2100 | bool *non_constant_p, bool *overflow_p) | |
2101 | { | |
2102 | tree arg1 = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), | |
2103 | /*lval*/false, | |
2104 | non_constant_p, overflow_p); | |
2105 | VERIFY_CONSTANT (arg1); | |
2106 | tree arg2 = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), | |
2107 | /*lval*/false, | |
2108 | non_constant_p, overflow_p); | |
2109 | VERIFY_CONSTANT (arg2); | |
2110 | tree arg3 = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 2), | |
2111 | /*lval*/false, | |
2112 | non_constant_p, overflow_p); | |
2113 | VERIFY_CONSTANT (arg3); | |
2114 | location_t loc = EXPR_LOCATION (t); | |
2115 | tree type = TREE_TYPE (t); | |
2116 | tree r = fold_ternary_loc (loc, VEC_COND_EXPR, type, arg1, arg2, arg3); | |
2117 | if (r == NULL_TREE) | |
2118 | { | |
2119 | if (arg1 == TREE_OPERAND (t, 0) | |
2120 | && arg2 == TREE_OPERAND (t, 1) | |
2121 | && arg3 == TREE_OPERAND (t, 2)) | |
2122 | r = t; | |
2123 | else | |
2124 | r = build3_loc (loc, VEC_COND_EXPR, type, arg1, arg2, arg3); | |
2125 | } | |
2126 | VERIFY_CONSTANT (r); | |
2127 | return r; | |
2128 | } | |
2129 | ||
ceaaf873 JM |
2130 | /* Returns less than, equal to, or greater than zero if KEY is found to be |
2131 | less than, to match, or to be greater than the constructor_elt's INDEX. */ | |
2132 | ||
2133 | static int | |
2134 | array_index_cmp (tree key, tree index) | |
2135 | { | |
2136 | gcc_assert (TREE_CODE (key) == INTEGER_CST); | |
2137 | ||
2138 | switch (TREE_CODE (index)) | |
2139 | { | |
2140 | case INTEGER_CST: | |
2141 | return tree_int_cst_compare (key, index); | |
2142 | case RANGE_EXPR: | |
2143 | { | |
2144 | tree lo = TREE_OPERAND (index, 0); | |
2145 | tree hi = TREE_OPERAND (index, 1); | |
2146 | if (tree_int_cst_lt (key, lo)) | |
2147 | return -1; | |
2148 | else if (tree_int_cst_lt (hi, key)) | |
2149 | return 1; | |
2150 | else | |
2151 | return 0; | |
2152 | } | |
2153 | default: | |
2154 | gcc_unreachable (); | |
2155 | } | |
2156 | } | |
2157 | ||
2158 | /* Returns the index of the constructor_elt of ARY which matches DINDEX, or -1 | |
2159 | if none. If INSERT is true, insert a matching element rather than fail. */ | |
2160 | ||
2161 | static HOST_WIDE_INT | |
2162 | find_array_ctor_elt (tree ary, tree dindex, bool insert = false) | |
2163 | { | |
2164 | if (tree_int_cst_sgn (dindex) < 0) | |
2165 | return -1; | |
2166 | ||
2167 | unsigned HOST_WIDE_INT i = tree_to_uhwi (dindex); | |
2168 | vec<constructor_elt, va_gc> *elts = CONSTRUCTOR_ELTS (ary); | |
2169 | unsigned HOST_WIDE_INT len = vec_safe_length (elts); | |
2170 | ||
2171 | unsigned HOST_WIDE_INT end = len; | |
2172 | unsigned HOST_WIDE_INT begin = 0; | |
2173 | ||
2174 | /* If the last element of the CONSTRUCTOR has its own index, we can assume | |
2175 | that the same is true of the other elements and index directly. */ | |
2176 | if (end > 0) | |
2177 | { | |
2178 | tree cindex = (*elts)[end-1].index; | |
2179 | if (TREE_CODE (cindex) == INTEGER_CST | |
2180 | && compare_tree_int (cindex, end-1) == 0) | |
2181 | { | |
2182 | if (i < end) | |
2183 | return i; | |
2184 | else | |
2185 | begin = end; | |
2186 | } | |
2187 | } | |
2188 | ||
2189 | /* Otherwise, find a matching index by means of a binary search. */ | |
2190 | while (begin != end) | |
2191 | { | |
2192 | unsigned HOST_WIDE_INT middle = (begin + end) / 2; | |
a7ccb9e7 JM |
2193 | constructor_elt &elt = (*elts)[middle]; |
2194 | tree idx = elt.index; | |
ceaaf873 | 2195 | |
a7ccb9e7 | 2196 | int cmp = array_index_cmp (dindex, idx); |
ceaaf873 JM |
2197 | if (cmp < 0) |
2198 | end = middle; | |
2199 | else if (cmp > 0) | |
2200 | begin = middle + 1; | |
2201 | else | |
a7ccb9e7 JM |
2202 | { |
2203 | if (insert && TREE_CODE (idx) == RANGE_EXPR) | |
2204 | { | |
2205 | /* We need to split the range. */ | |
2206 | constructor_elt e; | |
2207 | tree lo = TREE_OPERAND (idx, 0); | |
2208 | tree hi = TREE_OPERAND (idx, 1); | |
2209 | if (tree_int_cst_lt (lo, dindex)) | |
2210 | { | |
2211 | /* There are still some lower elts; shorten the range. */ | |
2212 | tree new_hi = int_const_binop (MINUS_EXPR, dindex, | |
2213 | size_one_node); | |
2214 | if (tree_int_cst_equal (lo, new_hi)) | |
2215 | /* Only one element left, no longer a range. */ | |
2216 | elt.index = lo; | |
2217 | else | |
2218 | TREE_OPERAND (idx, 1) = new_hi; | |
2219 | /* Append the element we want to insert. */ | |
2220 | ++middle; | |
2221 | e.index = dindex; | |
0146e25f | 2222 | e.value = unshare_constructor (elt.value); |
a7ccb9e7 JM |
2223 | vec_safe_insert (CONSTRUCTOR_ELTS (ary), middle, e); |
2224 | } | |
2225 | else | |
2226 | /* No lower elts, the range elt is now ours. */ | |
2227 | elt.index = dindex; | |
2228 | ||
2229 | if (tree_int_cst_lt (dindex, hi)) | |
2230 | { | |
2231 | /* There are still some higher elts; append a range. */ | |
2232 | tree new_lo = int_const_binop (PLUS_EXPR, dindex, | |
2233 | size_one_node); | |
2234 | if (tree_int_cst_equal (new_lo, hi)) | |
2235 | e.index = hi; | |
2236 | else | |
2237 | e.index = build2 (RANGE_EXPR, sizetype, new_lo, hi); | |
0146e25f | 2238 | e.value = unshare_constructor (elt.value); |
a7ccb9e7 JM |
2239 | vec_safe_insert (CONSTRUCTOR_ELTS (ary), middle+1, e); |
2240 | } | |
2241 | } | |
2242 | return middle; | |
2243 | } | |
ceaaf873 JM |
2244 | } |
2245 | ||
2246 | if (insert) | |
2247 | { | |
2248 | constructor_elt e = { dindex, NULL_TREE }; | |
2249 | vec_safe_insert (CONSTRUCTOR_ELTS (ary), end, e); | |
2250 | return end; | |
2251 | } | |
2252 | ||
2253 | return -1; | |
2254 | } | |
2255 | ||
abdc16c8 MS |
2256 | /* Under the control of CTX, issue a detailed diagnostic for |
2257 | an out-of-bounds subscript INDEX into the expression ARRAY. */ | |
2258 | ||
2259 | static void | |
2260 | diag_array_subscript (const constexpr_ctx *ctx, tree array, tree index) | |
2261 | { | |
2262 | if (!ctx->quiet) | |
2263 | { | |
2264 | tree arraytype = TREE_TYPE (array); | |
2265 | ||
2266 | /* Convert the unsigned array subscript to a signed integer to avoid | |
2267 | printing huge numbers for small negative values. */ | |
2268 | tree sidx = fold_convert (ssizetype, index); | |
2269 | if (DECL_P (array)) | |
2270 | { | |
2271 | error ("array subscript value %qE is outside the bounds " | |
2272 | "of array %qD of type %qT", sidx, array, arraytype); | |
2273 | inform (DECL_SOURCE_LOCATION (array), "declared here"); | |
2274 | } | |
2275 | else | |
2276 | error ("array subscript value %qE is outside the bounds " | |
2277 | "of array type %qT", sidx, arraytype); | |
2278 | } | |
2279 | } | |
ceaaf873 | 2280 | |
d6b46fca NS |
2281 | /* Extract element INDEX consisting of CHARS_PER_ELT chars from |
2282 | STRING_CST STRING. */ | |
2283 | ||
2284 | static tree | |
2285 | extract_string_elt (tree string, unsigned chars_per_elt, unsigned index) | |
2286 | { | |
2287 | tree type = cv_unqualified (TREE_TYPE (TREE_TYPE (string))); | |
2288 | tree r; | |
2289 | ||
2290 | if (chars_per_elt == 1) | |
2291 | r = build_int_cst (type, TREE_STRING_POINTER (string)[index]); | |
2292 | else | |
2293 | { | |
2294 | const unsigned char *ptr | |
2295 | = ((const unsigned char *)TREE_STRING_POINTER (string) | |
2296 | + index * chars_per_elt); | |
2297 | r = native_interpret_expr (type, ptr, chars_per_elt); | |
2298 | } | |
2299 | return r; | |
2300 | } | |
2301 | ||
2d76680f PC |
2302 | /* Subroutine of cxx_eval_constant_expression. |
2303 | Attempt to reduce a reference to an array slot. */ | |
2304 | ||
2305 | static tree | |
3e605b20 | 2306 | cxx_eval_array_reference (const constexpr_ctx *ctx, tree t, |
92a596e8 | 2307 | bool lval, |
2d76680f PC |
2308 | bool *non_constant_p, bool *overflow_p) |
2309 | { | |
2310 | tree oldary = TREE_OPERAND (t, 0); | |
3e605b20 | 2311 | tree ary = cxx_eval_constant_expression (ctx, oldary, |
92a596e8 | 2312 | lval, |
5a804683 | 2313 | non_constant_p, overflow_p); |
2d76680f | 2314 | tree index, oldidx; |
bc2a38df JJ |
2315 | HOST_WIDE_INT i = 0; |
2316 | tree elem_type = NULL_TREE; | |
2317 | unsigned len = 0, elem_nchars = 1; | |
2d76680f PC |
2318 | if (*non_constant_p) |
2319 | return t; | |
2320 | oldidx = TREE_OPERAND (t, 1); | |
3e605b20 | 2321 | index = cxx_eval_constant_expression (ctx, oldidx, |
2b3ab879 | 2322 | false, |
5a804683 | 2323 | non_constant_p, overflow_p); |
2d76680f | 2324 | VERIFY_CONSTANT (index); |
bc2a38df | 2325 | if (!lval) |
2d76680f | 2326 | { |
bc2a38df JJ |
2327 | elem_type = TREE_TYPE (TREE_TYPE (ary)); |
2328 | if (TREE_CODE (ary) == VIEW_CONVERT_EXPR | |
2329 | && VECTOR_TYPE_P (TREE_TYPE (TREE_OPERAND (ary, 0))) | |
2330 | && TREE_TYPE (t) == TREE_TYPE (TREE_TYPE (TREE_OPERAND (ary, 0)))) | |
2331 | ary = TREE_OPERAND (ary, 0); | |
2332 | if (TREE_CODE (ary) == CONSTRUCTOR) | |
2333 | len = CONSTRUCTOR_NELTS (ary); | |
2334 | else if (TREE_CODE (ary) == STRING_CST) | |
2335 | { | |
2336 | elem_nchars = (TYPE_PRECISION (elem_type) | |
2337 | / TYPE_PRECISION (char_type_node)); | |
2338 | len = (unsigned) TREE_STRING_LENGTH (ary) / elem_nchars; | |
2339 | } | |
2340 | else if (TREE_CODE (ary) == VECTOR_CST) | |
2341 | len = VECTOR_CST_NELTS (ary); | |
2342 | else | |
2343 | { | |
2344 | /* We can't do anything with other tree codes, so use | |
2345 | VERIFY_CONSTANT to complain and fail. */ | |
2346 | VERIFY_CONSTANT (ary); | |
2347 | gcc_unreachable (); | |
2348 | } | |
3b9997bb | 2349 | |
bc2a38df JJ |
2350 | if (!tree_fits_shwi_p (index) |
2351 | || (i = tree_to_shwi (index)) < 0) | |
2352 | { | |
2353 | diag_array_subscript (ctx, ary, index); | |
2354 | *non_constant_p = true; | |
2355 | return t; | |
2356 | } | |
ceaaf873 JM |
2357 | } |
2358 | ||
f17a223d RB |
2359 | tree nelts; |
2360 | if (TREE_CODE (TREE_TYPE (ary)) == ARRAY_TYPE) | |
2361 | nelts = array_type_nelts_top (TREE_TYPE (ary)); | |
2362 | else if (VECTOR_TYPE_P (TREE_TYPE (ary))) | |
2363 | nelts = size_int (TYPE_VECTOR_SUBPARTS (TREE_TYPE (ary))); | |
2364 | else | |
2365 | gcc_unreachable (); | |
2366 | ||
5453bfed MP |
2367 | /* For VLAs, the number of elements won't be an integer constant. */ |
2368 | nelts = cxx_eval_constant_expression (ctx, nelts, false, non_constant_p, | |
2369 | overflow_p); | |
2370 | VERIFY_CONSTANT (nelts); | |
3bb43119 JJ |
2371 | if ((lval |
2372 | ? !tree_int_cst_le (index, nelts) | |
2373 | : !tree_int_cst_lt (index, nelts)) | |
2374 | || tree_int_cst_sgn (index) < 0) | |
5453bfed | 2375 | { |
abdc16c8 | 2376 | diag_array_subscript (ctx, ary, index); |
5453bfed MP |
2377 | *non_constant_p = true; |
2378 | return t; | |
2379 | } | |
2380 | ||
bc2a38df JJ |
2381 | if (lval && ary == oldary && index == oldidx) |
2382 | return t; | |
2383 | else if (lval) | |
2384 | return build4 (ARRAY_REF, TREE_TYPE (t), ary, index, NULL, NULL); | |
2385 | ||
ceaaf873 JM |
2386 | bool found; |
2387 | if (TREE_CODE (ary) == CONSTRUCTOR) | |
2388 | { | |
2389 | HOST_WIDE_INT ix = find_array_ctor_elt (ary, index); | |
2390 | found = (ix >= 0); | |
2391 | if (found) | |
2392 | i = ix; | |
3b9997bb | 2393 | } |
ceaaf873 JM |
2394 | else |
2395 | found = (i < len); | |
3b9997bb | 2396 | |
fd2bfee5 JM |
2397 | if (found) |
2398 | { | |
2399 | tree r; | |
2400 | if (TREE_CODE (ary) == CONSTRUCTOR) | |
2401 | r = (*CONSTRUCTOR_ELTS (ary))[i].value; | |
2402 | else if (TREE_CODE (ary) == VECTOR_CST) | |
2403 | r = VECTOR_CST_ELT (ary, i); | |
fd2bfee5 | 2404 | else |
d6b46fca NS |
2405 | r = extract_string_elt (ary, elem_nchars, i); |
2406 | ||
fd2bfee5 JM |
2407 | if (r) |
2408 | /* Don't VERIFY_CONSTANT here. */ | |
2409 | return r; | |
2d76680f | 2410 | |
fd2bfee5 | 2411 | /* Otherwise the element doesn't have a value yet. */ |
2d76680f | 2412 | } |
3b9997bb | 2413 | |
fd2bfee5 JM |
2414 | /* Not found. */ |
2415 | ||
2416 | if (TREE_CODE (ary) == CONSTRUCTOR | |
2417 | && CONSTRUCTOR_NO_IMPLICIT_ZERO (ary)) | |
2d76680f | 2418 | { |
fd2bfee5 JM |
2419 | /* 'ary' is part of the aggregate initializer we're currently |
2420 | building; if there's no initializer for this element yet, | |
2421 | that's an error. */ | |
2422 | if (!ctx->quiet) | |
2423 | error ("accessing uninitialized array element"); | |
2424 | *non_constant_p = true; | |
2425 | return t; | |
2d76680f | 2426 | } |
fd2bfee5 JM |
2427 | |
2428 | /* If it's within the array bounds but doesn't have an explicit | |
2429 | initializer, it's value-initialized. */ | |
2430 | tree val = build_value_init (elem_type, tf_warning_or_error); | |
2431 | return cxx_eval_constant_expression (ctx, val, lval, non_constant_p, | |
2432 | overflow_p); | |
2d76680f PC |
2433 | } |
2434 | ||
2435 | /* Subroutine of cxx_eval_constant_expression. | |
2436 | Attempt to reduce a field access of a value of class type. */ | |
2437 | ||
2438 | static tree | |
3e605b20 | 2439 | cxx_eval_component_reference (const constexpr_ctx *ctx, tree t, |
92a596e8 | 2440 | bool lval, |
2d76680f PC |
2441 | bool *non_constant_p, bool *overflow_p) |
2442 | { | |
2443 | unsigned HOST_WIDE_INT i; | |
2444 | tree field; | |
2445 | tree value; | |
2446 | tree part = TREE_OPERAND (t, 1); | |
2447 | tree orig_whole = TREE_OPERAND (t, 0); | |
3e605b20 | 2448 | tree whole = cxx_eval_constant_expression (ctx, orig_whole, |
92a596e8 | 2449 | lval, |
5a804683 | 2450 | non_constant_p, overflow_p); |
8bada5cd MS |
2451 | if (TREE_CODE (whole) == INDIRECT_REF |
2452 | && integer_zerop (TREE_OPERAND (whole, 0)) | |
2453 | && !ctx->quiet) | |
2454 | error ("dereferencing a null pointer in %qE", orig_whole); | |
2455 | ||
dcdbc004 JM |
2456 | if (TREE_CODE (whole) == PTRMEM_CST) |
2457 | whole = cplus_expand_constant (whole); | |
2d76680f PC |
2458 | if (whole == orig_whole) |
2459 | return t; | |
92a596e8 | 2460 | if (lval) |
2d76680f PC |
2461 | return fold_build3 (COMPONENT_REF, TREE_TYPE (t), |
2462 | whole, part, NULL_TREE); | |
2463 | /* Don't VERIFY_CONSTANT here; we only want to check that we got a | |
2464 | CONSTRUCTOR. */ | |
2465 | if (!*non_constant_p && TREE_CODE (whole) != CONSTRUCTOR) | |
2466 | { | |
2b3ab879 | 2467 | if (!ctx->quiet) |
2d76680f PC |
2468 | error ("%qE is not a constant expression", orig_whole); |
2469 | *non_constant_p = true; | |
2470 | } | |
2471 | if (DECL_MUTABLE_P (part)) | |
2472 | { | |
2b3ab879 | 2473 | if (!ctx->quiet) |
2d76680f PC |
2474 | error ("mutable %qD is not usable in a constant expression", part); |
2475 | *non_constant_p = true; | |
2476 | } | |
2477 | if (*non_constant_p) | |
2478 | return t; | |
2db613e5 | 2479 | bool pmf = TYPE_PTRMEMFUNC_P (TREE_TYPE (whole)); |
2d76680f PC |
2480 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (whole), i, field, value) |
2481 | { | |
2db613e5 JM |
2482 | /* Use name match for PMF fields, as a variant will have a |
2483 | different FIELD_DECL with a different type. */ | |
2484 | if (pmf ? DECL_NAME (field) == DECL_NAME (part) | |
2485 | : field == part) | |
60813a46 JM |
2486 | { |
2487 | if (value) | |
2488 | return value; | |
2489 | else | |
2490 | /* We're in the middle of initializing it. */ | |
2491 | break; | |
2492 | } | |
2d76680f PC |
2493 | } |
2494 | if (TREE_CODE (TREE_TYPE (whole)) == UNION_TYPE | |
2495 | && CONSTRUCTOR_NELTS (whole) > 0) | |
2496 | { | |
2497 | /* DR 1188 says we don't have to deal with this. */ | |
2b3ab879 | 2498 | if (!ctx->quiet) |
2d76680f PC |
2499 | error ("accessing %qD member instead of initialized %qD member in " |
2500 | "constant expression", part, CONSTRUCTOR_ELT (whole, 0)->index); | |
2501 | *non_constant_p = true; | |
2502 | return t; | |
2503 | } | |
2504 | ||
188e53bd JM |
2505 | /* We only create a CONSTRUCTOR for a subobject when we modify it, so empty |
2506 | classes never get represented; throw together a value now. */ | |
2507 | if (is_really_empty_class (TREE_TYPE (t))) | |
2508 | return build_constructor (TREE_TYPE (t), NULL); | |
2509 | ||
2db613e5 JM |
2510 | gcc_assert (DECL_CONTEXT (part) == TYPE_MAIN_VARIANT (TREE_TYPE (whole))); |
2511 | ||
188e53bd | 2512 | if (CONSTRUCTOR_NO_IMPLICIT_ZERO (whole)) |
3e605b20 JM |
2513 | { |
2514 | /* 'whole' is part of the aggregate initializer we're currently | |
2515 | building; if there's no initializer for this member yet, that's an | |
188e53bd | 2516 | error. */ |
2b3ab879 | 2517 | if (!ctx->quiet) |
3e605b20 JM |
2518 | error ("accessing uninitialized member %qD", part); |
2519 | *non_constant_p = true; | |
2520 | return t; | |
2521 | } | |
2522 | ||
2d76680f PC |
2523 | /* If there's no explicit init for this field, it's value-initialized. */ |
2524 | value = build_value_init (TREE_TYPE (t), tf_warning_or_error); | |
3e605b20 | 2525 | return cxx_eval_constant_expression (ctx, value, |
92a596e8 | 2526 | lval, |
5a804683 | 2527 | non_constant_p, overflow_p); |
2d76680f PC |
2528 | } |
2529 | ||
2530 | /* Subroutine of cxx_eval_constant_expression. | |
2531 | Attempt to reduce a field access of a value of class type that is | |
2532 | expressed as a BIT_FIELD_REF. */ | |
2533 | ||
2534 | static tree | |
3e605b20 | 2535 | cxx_eval_bit_field_ref (const constexpr_ctx *ctx, tree t, |
92a596e8 | 2536 | bool lval, |
2d76680f PC |
2537 | bool *non_constant_p, bool *overflow_p) |
2538 | { | |
2539 | tree orig_whole = TREE_OPERAND (t, 0); | |
2540 | tree retval, fldval, utype, mask; | |
2541 | bool fld_seen = false; | |
2542 | HOST_WIDE_INT istart, isize; | |
3e605b20 | 2543 | tree whole = cxx_eval_constant_expression (ctx, orig_whole, |
92a596e8 | 2544 | lval, |
5a804683 | 2545 | non_constant_p, overflow_p); |
2d76680f PC |
2546 | tree start, field, value; |
2547 | unsigned HOST_WIDE_INT i; | |
2548 | ||
2549 | if (whole == orig_whole) | |
2550 | return t; | |
2551 | /* Don't VERIFY_CONSTANT here; we only want to check that we got a | |
2552 | CONSTRUCTOR. */ | |
2553 | if (!*non_constant_p | |
2554 | && TREE_CODE (whole) != VECTOR_CST | |
2555 | && TREE_CODE (whole) != CONSTRUCTOR) | |
2556 | { | |
2b3ab879 | 2557 | if (!ctx->quiet) |
2d76680f PC |
2558 | error ("%qE is not a constant expression", orig_whole); |
2559 | *non_constant_p = true; | |
2560 | } | |
2561 | if (*non_constant_p) | |
2562 | return t; | |
2563 | ||
2564 | if (TREE_CODE (whole) == VECTOR_CST) | |
2565 | return fold_ternary (BIT_FIELD_REF, TREE_TYPE (t), whole, | |
2566 | TREE_OPERAND (t, 1), TREE_OPERAND (t, 2)); | |
2567 | ||
2568 | start = TREE_OPERAND (t, 2); | |
2569 | istart = tree_to_shwi (start); | |
2570 | isize = tree_to_shwi (TREE_OPERAND (t, 1)); | |
2571 | utype = TREE_TYPE (t); | |
2572 | if (!TYPE_UNSIGNED (utype)) | |
2573 | utype = build_nonstandard_integer_type (TYPE_PRECISION (utype), 1); | |
2574 | retval = build_int_cst (utype, 0); | |
2575 | FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (whole), i, field, value) | |
2576 | { | |
2577 | tree bitpos = bit_position (field); | |
2578 | if (bitpos == start && DECL_SIZE (field) == TREE_OPERAND (t, 1)) | |
2579 | return value; | |
2580 | if (TREE_CODE (TREE_TYPE (field)) == INTEGER_TYPE | |
2581 | && TREE_CODE (value) == INTEGER_CST | |
2582 | && tree_fits_shwi_p (bitpos) | |
2583 | && tree_fits_shwi_p (DECL_SIZE (field))) | |
2584 | { | |
2585 | HOST_WIDE_INT bit = tree_to_shwi (bitpos); | |
2586 | HOST_WIDE_INT sz = tree_to_shwi (DECL_SIZE (field)); | |
2587 | HOST_WIDE_INT shift; | |
2588 | if (bit >= istart && bit + sz <= istart + isize) | |
2589 | { | |
2590 | fldval = fold_convert (utype, value); | |
2591 | mask = build_int_cst_type (utype, -1); | |
2592 | mask = fold_build2 (LSHIFT_EXPR, utype, mask, | |
2593 | size_int (TYPE_PRECISION (utype) - sz)); | |
2594 | mask = fold_build2 (RSHIFT_EXPR, utype, mask, | |
2595 | size_int (TYPE_PRECISION (utype) - sz)); | |
2596 | fldval = fold_build2 (BIT_AND_EXPR, utype, fldval, mask); | |
2597 | shift = bit - istart; | |
2598 | if (BYTES_BIG_ENDIAN) | |
2599 | shift = TYPE_PRECISION (utype) - shift - sz; | |
2600 | fldval = fold_build2 (LSHIFT_EXPR, utype, fldval, | |
2601 | size_int (shift)); | |
2602 | retval = fold_build2 (BIT_IOR_EXPR, utype, retval, fldval); | |
2603 | fld_seen = true; | |
2604 | } | |
2605 | } | |
2606 | } | |
2607 | if (fld_seen) | |
2608 | return fold_convert (TREE_TYPE (t), retval); | |
2609 | gcc_unreachable (); | |
2610 | return error_mark_node; | |
2611 | } | |
2612 | ||
2613 | /* Subroutine of cxx_eval_constant_expression. | |
2614 | Evaluate a short-circuited logical expression T in the context | |
2615 | of a given constexpr CALL. BAILOUT_VALUE is the value for | |
2616 | early return. CONTINUE_VALUE is used here purely for | |
2617 | sanity check purposes. */ | |
2618 | ||
2619 | static tree | |
3e605b20 | 2620 | cxx_eval_logical_expression (const constexpr_ctx *ctx, tree t, |
2d76680f | 2621 | tree bailout_value, tree continue_value, |
92a596e8 | 2622 | bool lval, |
2d76680f PC |
2623 | bool *non_constant_p, bool *overflow_p) |
2624 | { | |
2625 | tree r; | |
3e605b20 | 2626 | tree lhs = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), |
92a596e8 | 2627 | lval, |
5a804683 | 2628 | non_constant_p, overflow_p); |
2d76680f PC |
2629 | VERIFY_CONSTANT (lhs); |
2630 | if (tree_int_cst_equal (lhs, bailout_value)) | |
2631 | return lhs; | |
2632 | gcc_assert (tree_int_cst_equal (lhs, continue_value)); | |
3e605b20 | 2633 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), |
92a596e8 | 2634 | lval, non_constant_p, |
5a804683 | 2635 | overflow_p); |
2d76680f PC |
2636 | VERIFY_CONSTANT (r); |
2637 | return r; | |
2638 | } | |
2639 | ||
2640 | /* REF is a COMPONENT_REF designating a particular field. V is a vector of | |
2641 | CONSTRUCTOR elements to initialize (part of) an object containing that | |
2642 | field. Return a pointer to the constructor_elt corresponding to the | |
2643 | initialization of the field. */ | |
2644 | ||
2645 | static constructor_elt * | |
2646 | base_field_constructor_elt (vec<constructor_elt, va_gc> *v, tree ref) | |
2647 | { | |
2648 | tree aggr = TREE_OPERAND (ref, 0); | |
2649 | tree field = TREE_OPERAND (ref, 1); | |
2650 | HOST_WIDE_INT i; | |
2651 | constructor_elt *ce; | |
2652 | ||
2653 | gcc_assert (TREE_CODE (ref) == COMPONENT_REF); | |
2654 | ||
2655 | if (TREE_CODE (aggr) == COMPONENT_REF) | |
2656 | { | |
2657 | constructor_elt *base_ce | |
2658 | = base_field_constructor_elt (v, aggr); | |
2659 | v = CONSTRUCTOR_ELTS (base_ce->value); | |
2660 | } | |
2661 | ||
2662 | for (i = 0; vec_safe_iterate (v, i, &ce); ++i) | |
2663 | if (ce->index == field) | |
2664 | return ce; | |
2665 | ||
2666 | gcc_unreachable (); | |
2667 | return NULL; | |
2668 | } | |
2669 | ||
3e605b20 JM |
2670 | /* Some of the expressions fed to the constexpr mechanism are calls to |
2671 | constructors, which have type void. In that case, return the type being | |
2672 | initialized by the constructor. */ | |
2673 | ||
2674 | static tree | |
2675 | initialized_type (tree t) | |
2676 | { | |
2677 | if (TYPE_P (t)) | |
2678 | return t; | |
2679 | tree type = cv_unqualified (TREE_TYPE (t)); | |
2680 | if (TREE_CODE (t) == CALL_EXPR || TREE_CODE (t) == AGGR_INIT_EXPR) | |
2681 | { | |
2682 | /* A constructor call has void type, so we need to look deeper. */ | |
2683 | tree fn = get_function_named_in_call (t); | |
2684 | if (fn && TREE_CODE (fn) == FUNCTION_DECL | |
2685 | && DECL_CXX_CONSTRUCTOR_P (fn)) | |
2686 | type = DECL_CONTEXT (fn); | |
2687 | } | |
2688 | return type; | |
2689 | } | |
2690 | ||
2691 | /* We're about to initialize element INDEX of an array or class from VALUE. | |
2692 | Set up NEW_CTX appropriately by adjusting .object to refer to the | |
2693 | subobject and creating a new CONSTRUCTOR if the element is itself | |
2694 | a class or array. */ | |
2695 | ||
2696 | static void | |
2697 | init_subob_ctx (const constexpr_ctx *ctx, constexpr_ctx &new_ctx, | |
2698 | tree index, tree &value) | |
2699 | { | |
2700 | new_ctx = *ctx; | |
2701 | ||
2702 | if (index && TREE_CODE (index) != INTEGER_CST | |
2703 | && TREE_CODE (index) != FIELD_DECL) | |
2704 | /* This won't have an element in the new CONSTRUCTOR. */ | |
2705 | return; | |
2706 | ||
2707 | tree type = initialized_type (value); | |
2708 | if (!AGGREGATE_TYPE_P (type) && !VECTOR_TYPE_P (type)) | |
2709 | /* A non-aggregate member doesn't get its own CONSTRUCTOR. */ | |
2710 | return; | |
2711 | ||
2712 | /* The sub-aggregate initializer might contain a placeholder; | |
2713 | update object to refer to the subobject and ctor to refer to | |
2714 | the (newly created) sub-initializer. */ | |
2715 | if (ctx->object) | |
2716 | new_ctx.object = build_ctor_subob_ref (index, type, ctx->object); | |
2717 | tree elt = build_constructor (type, NULL); | |
2718 | CONSTRUCTOR_NO_IMPLICIT_ZERO (elt) = true; | |
2719 | new_ctx.ctor = elt; | |
2720 | ||
2721 | if (TREE_CODE (value) == TARGET_EXPR) | |
2722 | /* Avoid creating another CONSTRUCTOR when we expand the TARGET_EXPR. */ | |
2723 | value = TARGET_EXPR_INITIAL (value); | |
2724 | } | |
2725 | ||
2726 | /* We're about to process an initializer for a class or array TYPE. Make | |
2727 | sure that CTX is set up appropriately. */ | |
2728 | ||
2729 | static void | |
2730 | verify_ctor_sanity (const constexpr_ctx *ctx, tree type) | |
2731 | { | |
2732 | /* We don't bother building a ctor for an empty base subobject. */ | |
2733 | if (is_empty_class (type)) | |
2734 | return; | |
2735 | ||
2736 | /* We're in the middle of an initializer that might involve placeholders; | |
2737 | our caller should have created a CONSTRUCTOR for us to put the | |
2738 | initializer into. We will either return that constructor or T. */ | |
2739 | gcc_assert (ctx->ctor); | |
2740 | gcc_assert (same_type_ignoring_top_level_qualifiers_p | |
2741 | (type, TREE_TYPE (ctx->ctor))); | |
fe69277d JM |
2742 | /* We used to check that ctx->ctor was empty, but that isn't the case when |
2743 | the object is zero-initialized before calling the constructor. */ | |
3e605b20 | 2744 | if (ctx->object) |
176e79b5 JM |
2745 | { |
2746 | tree otype = TREE_TYPE (ctx->object); | |
2747 | gcc_assert (same_type_ignoring_top_level_qualifiers_p (type, otype) | |
2748 | /* Handle flexible array members. */ | |
2749 | || (TREE_CODE (otype) == ARRAY_TYPE | |
2750 | && TYPE_DOMAIN (otype) == NULL_TREE | |
2751 | && TREE_CODE (type) == ARRAY_TYPE | |
2752 | && (same_type_ignoring_top_level_qualifiers_p | |
2753 | (TREE_TYPE (type), TREE_TYPE (otype))))); | |
2754 | } | |
3e605b20 JM |
2755 | gcc_assert (!ctx->object || !DECL_P (ctx->object) |
2756 | || *(ctx->values->get (ctx->object)) == ctx->ctor); | |
2757 | } | |
2758 | ||
2d76680f PC |
2759 | /* Subroutine of cxx_eval_constant_expression. |
2760 | The expression tree T denotes a C-style array or a C-style | |
2761 | aggregate. Reduce it to a constant expression. */ | |
2762 | ||
2763 | static tree | |
3e605b20 | 2764 | cxx_eval_bare_aggregate (const constexpr_ctx *ctx, tree t, |
92a596e8 | 2765 | bool lval, |
2d76680f PC |
2766 | bool *non_constant_p, bool *overflow_p) |
2767 | { | |
2768 | vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (t); | |
2d76680f PC |
2769 | bool changed = false; |
2770 | gcc_assert (!BRACE_ENCLOSED_INITIALIZER_P (t)); | |
8a29084d | 2771 | tree type = TREE_TYPE (t); |
3e605b20 | 2772 | |
8a29084d | 2773 | constexpr_ctx new_ctx; |
d4619dc1 | 2774 | if (TYPE_PTRMEMFUNC_P (type) || VECTOR_TYPE_P (type)) |
8a29084d | 2775 | { |
d4619dc1 NS |
2776 | /* We don't really need the ctx->ctor business for a PMF or |
2777 | vector, but it's simpler to use the same code. */ | |
8a29084d JM |
2778 | new_ctx = *ctx; |
2779 | new_ctx.ctor = build_constructor (type, NULL); | |
2780 | new_ctx.object = NULL_TREE; | |
2781 | ctx = &new_ctx; | |
2782 | }; | |
2783 | verify_ctor_sanity (ctx, type); | |
3e605b20 JM |
2784 | vec<constructor_elt, va_gc> **p = &CONSTRUCTOR_ELTS (ctx->ctor); |
2785 | vec_alloc (*p, vec_safe_length (v)); | |
2786 | ||
2d63bc39 JM |
2787 | unsigned i; |
2788 | tree index, value; | |
2789 | bool constant_p = true; | |
2790 | bool side_effects_p = false; | |
3e605b20 | 2791 | FOR_EACH_CONSTRUCTOR_ELT (v, i, index, value) |
2d76680f | 2792 | { |
bcb5f3c9 | 2793 | tree orig_value = value; |
3e605b20 JM |
2794 | init_subob_ctx (ctx, new_ctx, index, value); |
2795 | if (new_ctx.ctor != ctx->ctor) | |
2796 | /* If we built a new CONSTRUCTOR, attach it now so that other | |
2797 | initializers can refer to it. */ | |
2798 | CONSTRUCTOR_APPEND_ELT (*p, index, new_ctx.ctor); | |
2799 | tree elt = cxx_eval_constant_expression (&new_ctx, value, | |
92a596e8 | 2800 | lval, |
5a804683 | 2801 | non_constant_p, overflow_p); |
2d76680f | 2802 | /* Don't VERIFY_CONSTANT here. */ |
2b3ab879 | 2803 | if (ctx->quiet && *non_constant_p) |
3e605b20 | 2804 | break; |
bcb5f3c9 | 2805 | if (elt != orig_value) |
2d76680f | 2806 | changed = true; |
2d63bc39 JM |
2807 | |
2808 | if (!TREE_CONSTANT (elt)) | |
2809 | constant_p = false; | |
2810 | if (TREE_SIDE_EFFECTS (elt)) | |
2811 | side_effects_p = true; | |
3e605b20 | 2812 | if (index && TREE_CODE (index) == COMPONENT_REF) |
2d76680f PC |
2813 | { |
2814 | /* This is an initialization of a vfield inside a base | |
2815 | subaggregate that we already initialized; push this | |
2816 | initialization into the previous initialization. */ | |
3e605b20 | 2817 | constructor_elt *inner = base_field_constructor_elt (*p, index); |
2d76680f | 2818 | inner->value = elt; |
3e605b20 | 2819 | changed = true; |
2d76680f | 2820 | } |
3e605b20 JM |
2821 | else if (index |
2822 | && (TREE_CODE (index) == NOP_EXPR | |
2823 | || TREE_CODE (index) == POINTER_PLUS_EXPR)) | |
2d76680f PC |
2824 | { |
2825 | /* This is an initializer for an empty base; now that we've | |
2826 | checked that it's constant, we can ignore it. */ | |
3e605b20 JM |
2827 | gcc_assert (is_empty_class (TREE_TYPE (TREE_TYPE (index)))); |
2828 | changed = true; | |
2829 | } | |
2830 | else if (new_ctx.ctor != ctx->ctor) | |
2831 | { | |
2832 | /* We appended this element above; update the value. */ | |
2833 | gcc_assert ((*p)->last().index == index); | |
2834 | (*p)->last().value = elt; | |
2d76680f PC |
2835 | } |
2836 | else | |
3e605b20 | 2837 | CONSTRUCTOR_APPEND_ELT (*p, index, elt); |
2d76680f PC |
2838 | } |
2839 | if (*non_constant_p || !changed) | |
3e605b20 JM |
2840 | return t; |
2841 | t = ctx->ctor; | |
2842 | /* We're done building this CONSTRUCTOR, so now we can interpret an | |
2843 | element without an explicit initializer as value-initialized. */ | |
2844 | CONSTRUCTOR_NO_IMPLICIT_ZERO (t) = false; | |
2d63bc39 JM |
2845 | TREE_CONSTANT (t) = constant_p; |
2846 | TREE_SIDE_EFFECTS (t) = side_effects_p; | |
8a29084d | 2847 | if (VECTOR_TYPE_P (type)) |
2d76680f PC |
2848 | t = fold (t); |
2849 | return t; | |
2850 | } | |
2851 | ||
2852 | /* Subroutine of cxx_eval_constant_expression. | |
2853 | The expression tree T is a VEC_INIT_EXPR which denotes the desired | |
2854 | initialization of a non-static data member of array type. Reduce it to a | |
2855 | CONSTRUCTOR. | |
2856 | ||
2857 | Note that apart from value-initialization (when VALUE_INIT is true), | |
2858 | this is only intended to support value-initialization and the | |
2859 | initializations done by defaulted constructors for classes with | |
2860 | non-static data members of array type. In this case, VEC_INIT_EXPR_INIT | |
2861 | will either be NULL_TREE for the default constructor, or a COMPONENT_REF | |
2862 | for the copy/move constructor. */ | |
2863 | ||
2864 | static tree | |
3e605b20 | 2865 | cxx_eval_vec_init_1 (const constexpr_ctx *ctx, tree atype, tree init, |
92a596e8 | 2866 | bool value_init, bool lval, |
2d76680f PC |
2867 | bool *non_constant_p, bool *overflow_p) |
2868 | { | |
2869 | tree elttype = TREE_TYPE (atype); | |
4784470a | 2870 | unsigned HOST_WIDE_INT max = tree_to_uhwi (array_type_nelts_top (atype)); |
3e605b20 JM |
2871 | verify_ctor_sanity (ctx, atype); |
2872 | vec<constructor_elt, va_gc> **p = &CONSTRUCTOR_ELTS (ctx->ctor); | |
2873 | vec_alloc (*p, max + 1); | |
2d76680f | 2874 | bool pre_init = false; |
4784470a | 2875 | unsigned HOST_WIDE_INT i; |
2d76680f PC |
2876 | |
2877 | /* For the default constructor, build up a call to the default | |
2878 | constructor of the element type. We only need to handle class types | |
2879 | here, as for a constructor to be constexpr, all members must be | |
2880 | initialized, which for a defaulted default constructor means they must | |
2881 | be of a class type with a constexpr default constructor. */ | |
2882 | if (TREE_CODE (elttype) == ARRAY_TYPE) | |
2883 | /* We only do this at the lowest level. */; | |
2884 | else if (value_init) | |
2885 | { | |
2886 | init = build_value_init (elttype, tf_warning_or_error); | |
2d76680f PC |
2887 | pre_init = true; |
2888 | } | |
2889 | else if (!init) | |
2890 | { | |
2891 | vec<tree, va_gc> *argvec = make_tree_vector (); | |
2892 | init = build_special_member_call (NULL_TREE, complete_ctor_identifier, | |
2893 | &argvec, elttype, LOOKUP_NORMAL, | |
2894 | tf_warning_or_error); | |
2895 | release_tree_vector (argvec); | |
60813a46 | 2896 | init = build_aggr_init_expr (TREE_TYPE (init), init); |
2d76680f PC |
2897 | pre_init = true; |
2898 | } | |
2899 | ||
4784470a | 2900 | for (i = 0; i < max; ++i) |
2d76680f PC |
2901 | { |
2902 | tree idx = build_int_cst (size_type_node, i); | |
2903 | tree eltinit; | |
928af3bf | 2904 | bool reuse = false; |
3e605b20 JM |
2905 | constexpr_ctx new_ctx; |
2906 | init_subob_ctx (ctx, new_ctx, idx, pre_init ? init : elttype); | |
2907 | if (new_ctx.ctor != ctx->ctor) | |
2908 | CONSTRUCTOR_APPEND_ELT (*p, idx, new_ctx.ctor); | |
2d76680f PC |
2909 | if (TREE_CODE (elttype) == ARRAY_TYPE) |
2910 | { | |
2911 | /* A multidimensional array; recurse. */ | |
2912 | if (value_init || init == NULL_TREE) | |
928af3bf JJ |
2913 | { |
2914 | eltinit = NULL_TREE; | |
2915 | reuse = i == 0; | |
2916 | } | |
2d76680f PC |
2917 | else |
2918 | eltinit = cp_build_array_ref (input_location, init, idx, | |
2919 | tf_warning_or_error); | |
3e605b20 | 2920 | eltinit = cxx_eval_vec_init_1 (&new_ctx, elttype, eltinit, value_init, |
92a596e8 | 2921 | lval, |
2d76680f PC |
2922 | non_constant_p, overflow_p); |
2923 | } | |
2924 | else if (pre_init) | |
2925 | { | |
2926 | /* Initializing an element using value or default initialization | |
2927 | we just pre-built above. */ | |
928af3bf JJ |
2928 | eltinit = cxx_eval_constant_expression (&new_ctx, init, lval, |
2929 | non_constant_p, overflow_p); | |
2930 | reuse = i == 0; | |
2d76680f PC |
2931 | } |
2932 | else | |
2933 | { | |
2934 | /* Copying an element. */ | |
2935 | gcc_assert (same_type_ignoring_top_level_qualifiers_p | |
2936 | (atype, TREE_TYPE (init))); | |
2937 | eltinit = cp_build_array_ref (input_location, init, idx, | |
2938 | tf_warning_or_error); | |
72b3e203 | 2939 | if (!lvalue_p (init)) |
2d76680f PC |
2940 | eltinit = move (eltinit); |
2941 | eltinit = force_rvalue (eltinit, tf_warning_or_error); | |
3e605b20 | 2942 | eltinit = (cxx_eval_constant_expression |
92a596e8 | 2943 | (&new_ctx, eltinit, lval, |
5a804683 | 2944 | non_constant_p, overflow_p)); |
2d76680f | 2945 | } |
2b3ab879 | 2946 | if (*non_constant_p && !ctx->quiet) |
3e605b20 JM |
2947 | break; |
2948 | if (new_ctx.ctor != ctx->ctor) | |
2949 | { | |
2950 | /* We appended this element above; update the value. */ | |
2951 | gcc_assert ((*p)->last().index == idx); | |
2952 | (*p)->last().value = eltinit; | |
2953 | } | |
2954 | else | |
2955 | CONSTRUCTOR_APPEND_ELT (*p, idx, eltinit); | |
928af3bf JJ |
2956 | /* Reuse the result of cxx_eval_constant_expression call |
2957 | from the first iteration to all others if it is a constant | |
2958 | initializer that doesn't require relocations. */ | |
2959 | if (reuse | |
2960 | && max > 1 | |
2961 | && (initializer_constant_valid_p (eltinit, TREE_TYPE (eltinit)) | |
2962 | == null_pointer_node)) | |
2963 | { | |
2964 | if (new_ctx.ctor != ctx->ctor) | |
2965 | eltinit = new_ctx.ctor; | |
2966 | for (i = 1; i < max; ++i) | |
2967 | { | |
2968 | idx = build_int_cst (size_type_node, i); | |
0146e25f | 2969 | CONSTRUCTOR_APPEND_ELT (*p, idx, unshare_constructor (eltinit)); |
928af3bf JJ |
2970 | } |
2971 | break; | |
2972 | } | |
2d76680f PC |
2973 | } |
2974 | ||
2975 | if (!*non_constant_p) | |
2976 | { | |
3e605b20 JM |
2977 | init = ctx->ctor; |
2978 | CONSTRUCTOR_NO_IMPLICIT_ZERO (init) = false; | |
2d76680f | 2979 | } |
2d76680f PC |
2980 | return init; |
2981 | } | |
2982 | ||
2983 | static tree | |
3e605b20 | 2984 | cxx_eval_vec_init (const constexpr_ctx *ctx, tree t, |
92a596e8 | 2985 | bool lval, |
2d76680f PC |
2986 | bool *non_constant_p, bool *overflow_p) |
2987 | { | |
2988 | tree atype = TREE_TYPE (t); | |
2989 | tree init = VEC_INIT_EXPR_INIT (t); | |
3e605b20 | 2990 | tree r = cxx_eval_vec_init_1 (ctx, atype, init, |
2d76680f | 2991 | VEC_INIT_EXPR_VALUE_INIT (t), |
92a596e8 | 2992 | lval, non_constant_p, overflow_p); |
2d76680f PC |
2993 | if (*non_constant_p) |
2994 | return t; | |
2995 | else | |
2996 | return r; | |
2997 | } | |
2998 | ||
2999 | /* A less strict version of fold_indirect_ref_1, which requires cv-quals to | |
3000 | match. We want to be less strict for simple *& folding; if we have a | |
3001 | non-const temporary that we access through a const pointer, that should | |
3002 | work. We handle this here rather than change fold_indirect_ref_1 | |
3003 | because we're dealing with things like ADDR_EXPR of INTEGER_CST which | |
3004 | don't really make sense outside of constant expression evaluation. Also | |
3005 | we want to allow folding to COMPONENT_REF, which could cause trouble | |
3006 | with TBAA in fold_indirect_ref_1. | |
3007 | ||
3008 | Try to keep this function synced with fold_indirect_ref_1. */ | |
3009 | ||
3010 | static tree | |
3011 | cxx_fold_indirect_ref (location_t loc, tree type, tree op0, bool *empty_base) | |
3012 | { | |
3013 | tree sub, subtype; | |
3014 | ||
3015 | sub = op0; | |
3016 | STRIP_NOPS (sub); | |
3017 | subtype = TREE_TYPE (sub); | |
3018 | if (!POINTER_TYPE_P (subtype)) | |
3019 | return NULL_TREE; | |
3020 | ||
3021 | if (TREE_CODE (sub) == ADDR_EXPR) | |
3022 | { | |
3023 | tree op = TREE_OPERAND (sub, 0); | |
3024 | tree optype = TREE_TYPE (op); | |
3025 | ||
3026 | /* *&CONST_DECL -> to the value of the const decl. */ | |
3027 | if (TREE_CODE (op) == CONST_DECL) | |
3028 | return DECL_INITIAL (op); | |
3029 | /* *&p => p; make sure to handle *&"str"[cst] here. */ | |
fe71aa4e JM |
3030 | if (same_type_ignoring_top_level_qualifiers_p (optype, type) |
3031 | /* Also handle the case where the desired type is an array of unknown | |
3032 | bounds because the variable has had its bounds deduced since the | |
3033 | ADDR_EXPR was created. */ | |
3034 | || (TREE_CODE (type) == ARRAY_TYPE | |
3035 | && TREE_CODE (optype) == ARRAY_TYPE | |
3036 | && TYPE_DOMAIN (type) == NULL_TREE | |
3037 | && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (optype), | |
3038 | TREE_TYPE (type)))) | |
2d76680f PC |
3039 | { |
3040 | tree fop = fold_read_from_constant_string (op); | |
3041 | if (fop) | |
3042 | return fop; | |
3043 | else | |
3044 | return op; | |
3045 | } | |
3046 | /* *(foo *)&fooarray => fooarray[0] */ | |
3047 | else if (TREE_CODE (optype) == ARRAY_TYPE | |
3048 | && (same_type_ignoring_top_level_qualifiers_p | |
3049 | (type, TREE_TYPE (optype)))) | |
3050 | { | |
3051 | tree type_domain = TYPE_DOMAIN (optype); | |
3052 | tree min_val = size_zero_node; | |
3053 | if (type_domain && TYPE_MIN_VALUE (type_domain)) | |
3054 | min_val = TYPE_MIN_VALUE (type_domain); | |
3055 | return build4_loc (loc, ARRAY_REF, type, op, min_val, | |
3056 | NULL_TREE, NULL_TREE); | |
3057 | } | |
3058 | /* *(foo *)&complexfoo => __real__ complexfoo */ | |
3059 | else if (TREE_CODE (optype) == COMPLEX_TYPE | |
3060 | && (same_type_ignoring_top_level_qualifiers_p | |
3061 | (type, TREE_TYPE (optype)))) | |
3062 | return fold_build1_loc (loc, REALPART_EXPR, type, op); | |
3063 | /* *(foo *)&vectorfoo => BIT_FIELD_REF<vectorfoo,...> */ | |
b55b02ea | 3064 | else if (VECTOR_TYPE_P (optype) |
2d76680f PC |
3065 | && (same_type_ignoring_top_level_qualifiers_p |
3066 | (type, TREE_TYPE (optype)))) | |
3067 | { | |
3068 | tree part_width = TYPE_SIZE (type); | |
3069 | tree index = bitsize_int (0); | |
3070 | return fold_build3_loc (loc, BIT_FIELD_REF, type, op, part_width, index); | |
3071 | } | |
3072 | /* Also handle conversion to an empty base class, which | |
3073 | is represented with a NOP_EXPR. */ | |
3074 | else if (is_empty_class (type) | |
3075 | && CLASS_TYPE_P (optype) | |
3076 | && DERIVED_FROM_P (type, optype)) | |
3077 | { | |
3078 | *empty_base = true; | |
3079 | return op; | |
3080 | } | |
3081 | /* *(foo *)&struct_with_foo_field => COMPONENT_REF */ | |
3082 | else if (RECORD_OR_UNION_TYPE_P (optype)) | |
3083 | { | |
3084 | tree field = TYPE_FIELDS (optype); | |
3085 | for (; field; field = DECL_CHAIN (field)) | |
3086 | if (TREE_CODE (field) == FIELD_DECL | |
b912f962 | 3087 | && TREE_TYPE (field) != error_mark_node |
2d76680f PC |
3088 | && integer_zerop (byte_position (field)) |
3089 | && (same_type_ignoring_top_level_qualifiers_p | |
3090 | (TREE_TYPE (field), type))) | |
b912f962 | 3091 | return fold_build3 (COMPONENT_REF, type, op, field, NULL_TREE); |
2d76680f PC |
3092 | } |
3093 | } | |
3094 | else if (TREE_CODE (sub) == POINTER_PLUS_EXPR | |
3095 | && TREE_CODE (TREE_OPERAND (sub, 1)) == INTEGER_CST) | |
3096 | { | |
3097 | tree op00 = TREE_OPERAND (sub, 0); | |
3098 | tree op01 = TREE_OPERAND (sub, 1); | |
3099 | ||
3100 | STRIP_NOPS (op00); | |
3101 | if (TREE_CODE (op00) == ADDR_EXPR) | |
3102 | { | |
3103 | tree op00type; | |
3104 | op00 = TREE_OPERAND (op00, 0); | |
3105 | op00type = TREE_TYPE (op00); | |
3106 | ||
3107 | /* ((foo*)&vectorfoo)[1] => BIT_FIELD_REF<vectorfoo,...> */ | |
b55b02ea | 3108 | if (VECTOR_TYPE_P (op00type) |
2d76680f PC |
3109 | && (same_type_ignoring_top_level_qualifiers_p |
3110 | (type, TREE_TYPE (op00type)))) | |
3111 | { | |
3112 | HOST_WIDE_INT offset = tree_to_shwi (op01); | |
3113 | tree part_width = TYPE_SIZE (type); | |
3114 | unsigned HOST_WIDE_INT part_widthi = tree_to_shwi (part_width)/BITS_PER_UNIT; | |
3115 | unsigned HOST_WIDE_INT indexi = offset * BITS_PER_UNIT; | |
3116 | tree index = bitsize_int (indexi); | |
3117 | ||
3118 | if (offset / part_widthi < TYPE_VECTOR_SUBPARTS (op00type)) | |
3119 | return fold_build3_loc (loc, | |
3120 | BIT_FIELD_REF, type, op00, | |
3121 | part_width, index); | |
3122 | ||
3123 | } | |
3124 | /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */ | |
3125 | else if (TREE_CODE (op00type) == COMPLEX_TYPE | |
3126 | && (same_type_ignoring_top_level_qualifiers_p | |
3127 | (type, TREE_TYPE (op00type)))) | |
3128 | { | |
3129 | tree size = TYPE_SIZE_UNIT (type); | |
3130 | if (tree_int_cst_equal (size, op01)) | |
3131 | return fold_build1_loc (loc, IMAGPART_EXPR, type, op00); | |
3132 | } | |
3133 | /* ((foo *)&fooarray)[1] => fooarray[1] */ | |
3134 | else if (TREE_CODE (op00type) == ARRAY_TYPE | |
3135 | && (same_type_ignoring_top_level_qualifiers_p | |
3136 | (type, TREE_TYPE (op00type)))) | |
3137 | { | |
3138 | tree type_domain = TYPE_DOMAIN (op00type); | |
3139 | tree min_val = size_zero_node; | |
3140 | if (type_domain && TYPE_MIN_VALUE (type_domain)) | |
3141 | min_val = TYPE_MIN_VALUE (type_domain); | |
3142 | op01 = size_binop_loc (loc, EXACT_DIV_EXPR, op01, | |
3143 | TYPE_SIZE_UNIT (type)); | |
3144 | op01 = size_binop_loc (loc, PLUS_EXPR, op01, min_val); | |
3145 | return build4_loc (loc, ARRAY_REF, type, op00, op01, | |
3146 | NULL_TREE, NULL_TREE); | |
3147 | } | |
3148 | /* Also handle conversion to an empty base class, which | |
3149 | is represented with a NOP_EXPR. */ | |
3150 | else if (is_empty_class (type) | |
3151 | && CLASS_TYPE_P (op00type) | |
3152 | && DERIVED_FROM_P (type, op00type)) | |
3153 | { | |
3154 | *empty_base = true; | |
3155 | return op00; | |
3156 | } | |
3157 | /* ((foo *)&struct_with_foo_field)[1] => COMPONENT_REF */ | |
3158 | else if (RECORD_OR_UNION_TYPE_P (op00type)) | |
3159 | { | |
3160 | tree field = TYPE_FIELDS (op00type); | |
3161 | for (; field; field = DECL_CHAIN (field)) | |
3162 | if (TREE_CODE (field) == FIELD_DECL | |
b912f962 | 3163 | && TREE_TYPE (field) != error_mark_node |
2d76680f PC |
3164 | && tree_int_cst_equal (byte_position (field), op01) |
3165 | && (same_type_ignoring_top_level_qualifiers_p | |
3166 | (TREE_TYPE (field), type))) | |
b912f962 JJ |
3167 | return fold_build3 (COMPONENT_REF, type, op00, |
3168 | field, NULL_TREE); | |
2d76680f PC |
3169 | } |
3170 | } | |
3171 | } | |
3172 | /* *(foo *)fooarrptr => (*fooarrptr)[0] */ | |
3173 | else if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE | |
3174 | && (same_type_ignoring_top_level_qualifiers_p | |
3175 | (type, TREE_TYPE (TREE_TYPE (subtype))))) | |
3176 | { | |
3177 | tree type_domain; | |
3178 | tree min_val = size_zero_node; | |
3179 | tree newsub = cxx_fold_indirect_ref (loc, TREE_TYPE (subtype), sub, NULL); | |
3180 | if (newsub) | |
3181 | sub = newsub; | |
3182 | else | |
3183 | sub = build1_loc (loc, INDIRECT_REF, TREE_TYPE (subtype), sub); | |
3184 | type_domain = TYPE_DOMAIN (TREE_TYPE (sub)); | |
3185 | if (type_domain && TYPE_MIN_VALUE (type_domain)) | |
3186 | min_val = TYPE_MIN_VALUE (type_domain); | |
3187 | return build4_loc (loc, ARRAY_REF, type, sub, min_val, NULL_TREE, | |
3188 | NULL_TREE); | |
3189 | } | |
3190 | ||
3191 | return NULL_TREE; | |
3192 | } | |
3193 | ||
3194 | static tree | |
3e605b20 | 3195 | cxx_eval_indirect_ref (const constexpr_ctx *ctx, tree t, |
92a596e8 | 3196 | bool lval, |
2d76680f PC |
3197 | bool *non_constant_p, bool *overflow_p) |
3198 | { | |
3199 | tree orig_op0 = TREE_OPERAND (t, 0); | |
2d76680f | 3200 | bool empty_base = false; |
2d76680f | 3201 | |
cda0a029 JM |
3202 | /* We can handle a MEM_REF like an INDIRECT_REF, if MEM_REF's second |
3203 | operand is an integer-zero. Otherwise reject the MEM_REF for now. */ | |
3204 | ||
3205 | if (TREE_CODE (t) == MEM_REF | |
3206 | && (!TREE_OPERAND (t, 1) || !integer_zerop (TREE_OPERAND (t, 1)))) | |
3207 | { | |
3208 | gcc_assert (ctx->quiet); | |
3209 | *non_constant_p = true; | |
3210 | return t; | |
3211 | } | |
3212 | ||
255a48d6 JM |
3213 | /* First try to simplify it directly. */ |
3214 | tree r = cxx_fold_indirect_ref (EXPR_LOCATION (t), TREE_TYPE (t), orig_op0, | |
3215 | &empty_base); | |
3216 | if (!r) | |
2d76680f | 3217 | { |
255a48d6 JM |
3218 | /* If that didn't work, evaluate the operand first. */ |
3219 | tree op0 = cxx_eval_constant_expression (ctx, orig_op0, | |
3220 | /*lval*/false, non_constant_p, | |
3221 | overflow_p); | |
3222 | /* Don't VERIFY_CONSTANT here. */ | |
3223 | if (*non_constant_p) | |
3224 | return t; | |
3225 | ||
8bada5cd MS |
3226 | if (!lval && integer_zerop (op0)) |
3227 | { | |
3228 | if (!ctx->quiet) | |
3229 | error ("dereferencing a null pointer"); | |
3230 | *non_constant_p = true; | |
3231 | return t; | |
3232 | } | |
3233 | ||
255a48d6 JM |
3234 | r = cxx_fold_indirect_ref (EXPR_LOCATION (t), TREE_TYPE (t), op0, |
3235 | &empty_base); | |
3236 | if (r == NULL_TREE) | |
2d76680f PC |
3237 | { |
3238 | /* We couldn't fold to a constant value. Make sure it's not | |
3239 | something we should have been able to fold. */ | |
255a48d6 JM |
3240 | tree sub = op0; |
3241 | STRIP_NOPS (sub); | |
3242 | if (TREE_CODE (sub) == ADDR_EXPR) | |
3243 | { | |
3244 | gcc_assert (!same_type_ignoring_top_level_qualifiers_p | |
3245 | (TREE_TYPE (TREE_TYPE (sub)), TREE_TYPE (t))); | |
3246 | /* DR 1188 says we don't have to deal with this. */ | |
3247 | if (!ctx->quiet) | |
3248 | error ("accessing value of %qE through a %qT glvalue in a " | |
3249 | "constant expression", build_fold_indirect_ref (sub), | |
3250 | TREE_TYPE (t)); | |
3251 | *non_constant_p = true; | |
3252 | return t; | |
3253 | } | |
3254 | ||
3255 | if (lval && op0 != orig_op0) | |
3256 | return build1 (INDIRECT_REF, TREE_TYPE (t), op0); | |
3257 | if (!lval) | |
3258 | VERIFY_CONSTANT (t); | |
2d76680f PC |
3259 | return t; |
3260 | } | |
3261 | } | |
3262 | ||
255a48d6 JM |
3263 | r = cxx_eval_constant_expression (ctx, r, |
3264 | lval, non_constant_p, overflow_p); | |
3265 | if (*non_constant_p) | |
3266 | return t; | |
3267 | ||
125db6a1 | 3268 | /* If we're pulling out the value of an empty base, just return an empty |
2d76680f | 3269 | CONSTRUCTOR. */ |
92a596e8 | 3270 | if (empty_base && !lval) |
2d76680f | 3271 | { |
2d76680f PC |
3272 | r = build_constructor (TREE_TYPE (t), NULL); |
3273 | TREE_CONSTANT (r) = true; | |
3274 | } | |
3275 | ||
2d76680f PC |
3276 | return r; |
3277 | } | |
3278 | ||
3279 | /* Complain about R, a VAR_DECL, not being usable in a constant expression. | |
3280 | Shared between potential_constant_expression and | |
3281 | cxx_eval_constant_expression. */ | |
3282 | ||
3283 | static void | |
3284 | non_const_var_error (tree r) | |
3285 | { | |
3286 | tree type = TREE_TYPE (r); | |
3287 | error ("the value of %qD is not usable in a constant " | |
3288 | "expression", r); | |
3289 | /* Avoid error cascade. */ | |
3290 | if (DECL_INITIAL (r) == error_mark_node) | |
3291 | return; | |
3292 | if (DECL_DECLARED_CONSTEXPR_P (r)) | |
3293 | inform (DECL_SOURCE_LOCATION (r), | |
3294 | "%qD used in its own initializer", r); | |
3295 | else if (INTEGRAL_OR_ENUMERATION_TYPE_P (type)) | |
3296 | { | |
3297 | if (!CP_TYPE_CONST_P (type)) | |
3298 | inform (DECL_SOURCE_LOCATION (r), | |
3299 | "%q#D is not const", r); | |
3300 | else if (CP_TYPE_VOLATILE_P (type)) | |
3301 | inform (DECL_SOURCE_LOCATION (r), | |
3302 | "%q#D is volatile", r); | |
3303 | else if (!DECL_INITIAL (r) | |
a3e2b438 PP |
3304 | || !TREE_CONSTANT (DECL_INITIAL (r)) |
3305 | || !DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r)) | |
2d76680f PC |
3306 | inform (DECL_SOURCE_LOCATION (r), |
3307 | "%qD was not initialized with a constant " | |
3308 | "expression", r); | |
3309 | else | |
3310 | gcc_unreachable (); | |
3311 | } | |
fd338b13 JM |
3312 | else if (TREE_CODE (type) == REFERENCE_TYPE) |
3313 | inform (DECL_SOURCE_LOCATION (r), | |
3314 | "%qD was not initialized with a constant " | |
3315 | "expression", r); | |
2d76680f PC |
3316 | else |
3317 | { | |
3318 | if (cxx_dialect >= cxx11 && !DECL_DECLARED_CONSTEXPR_P (r)) | |
3319 | inform (DECL_SOURCE_LOCATION (r), | |
3320 | "%qD was not declared %<constexpr%>", r); | |
3321 | else | |
3322 | inform (DECL_SOURCE_LOCATION (r), | |
3323 | "%qD does not have integral or enumeration type", | |
3324 | r); | |
3325 | } | |
3326 | } | |
3327 | ||
3328 | /* Subroutine of cxx_eval_constant_expression. | |
3329 | Like cxx_eval_unary_expression, except for trinary expressions. */ | |
3330 | ||
3331 | static tree | |
3e605b20 | 3332 | cxx_eval_trinary_expression (const constexpr_ctx *ctx, tree t, |
92a596e8 | 3333 | bool lval, |
2d76680f PC |
3334 | bool *non_constant_p, bool *overflow_p) |
3335 | { | |
3336 | int i; | |
3337 | tree args[3]; | |
3338 | tree val; | |
3339 | ||
3340 | for (i = 0; i < 3; i++) | |
3341 | { | |
3e605b20 | 3342 | args[i] = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, i), |
92a596e8 | 3343 | lval, |
5a804683 | 3344 | non_constant_p, overflow_p); |
2d76680f PC |
3345 | VERIFY_CONSTANT (args[i]); |
3346 | } | |
3347 | ||
3348 | val = fold_ternary_loc (EXPR_LOCATION (t), TREE_CODE (t), TREE_TYPE (t), | |
3349 | args[0], args[1], args[2]); | |
3350 | if (val == NULL_TREE) | |
3351 | return t; | |
3352 | VERIFY_CONSTANT (val); | |
3353 | return val; | |
3354 | } | |
3355 | ||
98e5a19a JM |
3356 | /* True if T was declared in a function declared to be constexpr, and |
3357 | therefore potentially constant in C++14. */ | |
3358 | ||
2d76680f PC |
3359 | bool |
3360 | var_in_constexpr_fn (tree t) | |
3361 | { | |
3362 | tree ctx = DECL_CONTEXT (t); | |
98e5a19a | 3363 | return (ctx && TREE_CODE (ctx) == FUNCTION_DECL |
2d76680f PC |
3364 | && DECL_DECLARED_CONSTEXPR_P (ctx)); |
3365 | } | |
3366 | ||
98e5a19a JM |
3367 | /* True if T was declared in a function that might be constexpr: either a |
3368 | function that was declared constexpr, or a C++17 lambda op(). */ | |
3369 | ||
3370 | bool | |
3371 | var_in_maybe_constexpr_fn (tree t) | |
3372 | { | |
7b936140 | 3373 | if (cxx_dialect >= cxx17 |
98e5a19a JM |
3374 | && DECL_FUNCTION_SCOPE_P (t) |
3375 | && LAMBDA_FUNCTION_P (DECL_CONTEXT (t))) | |
3376 | return true; | |
3377 | return var_in_constexpr_fn (t); | |
3378 | } | |
3379 | ||
68d01920 JM |
3380 | /* We're assigning INIT to TARGET. In do_build_copy_constructor and |
3381 | build_over_call we implement trivial copy of a class with tail padding using | |
3382 | assignment of character arrays, which is valid in normal code, but not in | |
3383 | constexpr evaluation. We don't need to worry about clobbering tail padding | |
3384 | in constexpr evaluation, so strip the type punning. */ | |
3385 | ||
3386 | static void | |
3387 | maybe_simplify_trivial_copy (tree &target, tree &init) | |
3388 | { | |
3389 | if (TREE_CODE (target) == MEM_REF | |
3390 | && TREE_CODE (init) == MEM_REF | |
3391 | && TREE_TYPE (target) == TREE_TYPE (init) | |
3392 | && TREE_CODE (TREE_TYPE (target)) == ARRAY_TYPE | |
3393 | && TREE_TYPE (TREE_TYPE (target)) == unsigned_char_type_node) | |
3394 | { | |
3395 | target = build_fold_indirect_ref (TREE_OPERAND (target, 0)); | |
3396 | init = build_fold_indirect_ref (TREE_OPERAND (init, 0)); | |
3397 | } | |
3398 | } | |
3399 | ||
60813a46 JM |
3400 | /* Evaluate an INIT_EXPR or MODIFY_EXPR. */ |
3401 | ||
3402 | static tree | |
3403 | cxx_eval_store_expression (const constexpr_ctx *ctx, tree t, | |
92a596e8 | 3404 | bool lval, |
60813a46 JM |
3405 | bool *non_constant_p, bool *overflow_p) |
3406 | { | |
3407 | constexpr_ctx new_ctx = *ctx; | |
3408 | ||
58cc255c JM |
3409 | tree init = TREE_OPERAND (t, 1); |
3410 | if (TREE_CLOBBER_P (init)) | |
3411 | /* Just ignore clobbers. */ | |
3412 | return void_node; | |
3413 | ||
60813a46 JM |
3414 | /* First we figure out where we're storing to. */ |
3415 | tree target = TREE_OPERAND (t, 0); | |
68d01920 JM |
3416 | |
3417 | maybe_simplify_trivial_copy (target, init); | |
3418 | ||
3f8e2835 | 3419 | tree type = TREE_TYPE (target); |
60813a46 | 3420 | target = cxx_eval_constant_expression (ctx, target, |
2b3ab879 | 3421 | true, |
5a804683 | 3422 | non_constant_p, overflow_p); |
60813a46 JM |
3423 | if (*non_constant_p) |
3424 | return t; | |
3425 | ||
bc2a38df JJ |
3426 | /* cxx_eval_array_reference for lval = true allows references one past |
3427 | end of array, because it does not know if it is just taking address | |
3428 | (which is valid), or actual dereference. Here we know it is | |
3429 | a dereference, so diagnose it here. */ | |
3430 | for (tree probe = target; probe; ) | |
3431 | { | |
3432 | switch (TREE_CODE (probe)) | |
3433 | { | |
3434 | case ARRAY_REF: | |
3435 | tree nelts, ary; | |
3436 | ary = TREE_OPERAND (probe, 0); | |
3437 | if (TREE_CODE (TREE_TYPE (ary)) == ARRAY_TYPE) | |
3438 | nelts = array_type_nelts_top (TREE_TYPE (ary)); | |
3439 | else if (VECTOR_TYPE_P (TREE_TYPE (ary))) | |
3440 | nelts = size_int (TYPE_VECTOR_SUBPARTS (TREE_TYPE (ary))); | |
3441 | else | |
3442 | gcc_unreachable (); | |
3443 | nelts = cxx_eval_constant_expression (ctx, nelts, false, | |
3444 | non_constant_p, overflow_p); | |
3445 | VERIFY_CONSTANT (nelts); | |
3446 | gcc_assert (TREE_CODE (nelts) == INTEGER_CST | |
3447 | && TREE_CODE (TREE_OPERAND (probe, 1)) == INTEGER_CST); | |
a1488398 | 3448 | if (wi::to_widest (TREE_OPERAND (probe, 1)) == wi::to_widest (nelts)) |
bc2a38df JJ |
3449 | { |
3450 | diag_array_subscript (ctx, ary, TREE_OPERAND (probe, 1)); | |
3451 | *non_constant_p = true; | |
3452 | return t; | |
3453 | } | |
3454 | /* FALLTHRU */ | |
3455 | ||
3456 | case BIT_FIELD_REF: | |
3457 | case COMPONENT_REF: | |
3458 | probe = TREE_OPERAND (probe, 0); | |
3459 | continue; | |
3460 | ||
3461 | default: | |
3462 | probe = NULL_TREE; | |
3463 | continue; | |
3464 | } | |
3465 | } | |
3466 | ||
3f8e2835 JM |
3467 | if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (target), type)) |
3468 | { | |
3469 | /* For initialization of an empty base, the original target will be | |
3470 | *(base*)this, which the above evaluation resolves to the object | |
3471 | argument, which has the derived type rather than the base type. In | |
3472 | this situation, just evaluate the initializer and return, since | |
3473 | there's no actual data to store. */ | |
3474 | gcc_assert (is_empty_class (type)); | |
3475 | return cxx_eval_constant_expression (ctx, init, false, | |
3476 | non_constant_p, overflow_p); | |
3477 | } | |
3478 | ||
60813a46 JM |
3479 | /* And then find the underlying variable. */ |
3480 | vec<tree,va_gc> *refs = make_tree_vector(); | |
3481 | tree object = NULL_TREE; | |
3482 | for (tree probe = target; object == NULL_TREE; ) | |
3483 | { | |
3484 | switch (TREE_CODE (probe)) | |
3485 | { | |
3486 | case BIT_FIELD_REF: | |
3487 | case COMPONENT_REF: | |
3488 | case ARRAY_REF: | |
3489 | vec_safe_push (refs, TREE_OPERAND (probe, 1)); | |
3490 | vec_safe_push (refs, TREE_TYPE (probe)); | |
3491 | probe = TREE_OPERAND (probe, 0); | |
3492 | break; | |
3493 | ||
3494 | default: | |
3495 | object = probe; | |
60813a46 JM |
3496 | } |
3497 | } | |
3498 | ||
3499 | /* And then find/build up our initializer for the path to the subobject | |
3500 | we're initializing. */ | |
a1408b7e | 3501 | tree *valp; |
1e163090 JM |
3502 | if (object == ctx->object && VAR_P (object) |
3503 | && DECL_NAME (object) && ctx->call == NULL) | |
3504 | /* The variable we're building up an aggregate initializer for is outside | |
3505 | the constant-expression, so don't evaluate the store. We check | |
3506 | DECL_NAME to handle TARGET_EXPR temporaries, which are fair game. */ | |
3507 | valp = NULL; | |
3508 | else if (DECL_P (object)) | |
a1408b7e JM |
3509 | valp = ctx->values->get (object); |
3510 | else | |
3511 | valp = NULL; | |
60813a46 JM |
3512 | if (!valp) |
3513 | { | |
3514 | /* A constant-expression cannot modify objects from outside the | |
3515 | constant-expression. */ | |
2b3ab879 | 3516 | if (!ctx->quiet) |
64d6d399 | 3517 | error ("modification of %qE is not a constant expression", object); |
60813a46 JM |
3518 | *non_constant_p = true; |
3519 | return t; | |
3520 | } | |
3f8e2835 | 3521 | type = TREE_TYPE (object); |
c75ce530 | 3522 | bool no_zero_init = true; |
2d63bc39 JM |
3523 | |
3524 | vec<tree,va_gc> *ctors = make_tree_vector (); | |
60813a46 JM |
3525 | while (!refs->is_empty()) |
3526 | { | |
3527 | if (*valp == NULL_TREE) | |
3528 | { | |
3529 | *valp = build_constructor (type, NULL); | |
c75ce530 | 3530 | CONSTRUCTOR_NO_IMPLICIT_ZERO (*valp) = no_zero_init; |
60813a46 | 3531 | } |
d6b46fca NS |
3532 | else if (TREE_CODE (*valp) == STRING_CST) |
3533 | { | |
3534 | /* An array was initialized with a string constant, and now | |
3535 | we're writing into one of its elements. Explode the | |
3536 | single initialization into a set of element | |
3537 | initializations. */ | |
3538 | gcc_assert (TREE_CODE (type) == ARRAY_TYPE); | |
3539 | ||
3540 | tree string = *valp; | |
3541 | tree elt_type = TREE_TYPE (type); | |
3542 | unsigned chars_per_elt = (TYPE_PRECISION (elt_type) | |
3543 | / TYPE_PRECISION (char_type_node)); | |
3544 | unsigned num_elts = TREE_STRING_LENGTH (string) / chars_per_elt; | |
3545 | tree ary_ctor = build_constructor (type, NULL); | |
3546 | ||
3547 | vec_safe_reserve (CONSTRUCTOR_ELTS (ary_ctor), num_elts); | |
3548 | for (unsigned ix = 0; ix != num_elts; ix++) | |
3549 | { | |
3550 | constructor_elt elt = | |
3551 | { | |
3552 | build_int_cst (size_type_node, ix), | |
3553 | extract_string_elt (string, chars_per_elt, ix) | |
3554 | }; | |
3555 | CONSTRUCTOR_ELTS (ary_ctor)->quick_push (elt); | |
3556 | } | |
3557 | ||
3558 | *valp = ary_ctor; | |
3559 | } | |
3560 | ||
c75ce530 JM |
3561 | /* If the value of object is already zero-initialized, any new ctors for |
3562 | subobjects will also be zero-initialized. */ | |
3563 | no_zero_init = CONSTRUCTOR_NO_IMPLICIT_ZERO (*valp); | |
60813a46 | 3564 | |
2d63bc39 JM |
3565 | vec_safe_push (ctors, *valp); |
3566 | ||
ceaaf873 | 3567 | enum tree_code code = TREE_CODE (type); |
60813a46 | 3568 | type = refs->pop(); |
ceaaf873 | 3569 | tree index = refs->pop(); |
60813a46 | 3570 | |
60813a46 | 3571 | constructor_elt *cep = NULL; |
ceaaf873 JM |
3572 | if (code == ARRAY_TYPE) |
3573 | { | |
3574 | HOST_WIDE_INT i | |
3575 | = find_array_ctor_elt (*valp, index, /*insert*/true); | |
3576 | gcc_assert (i >= 0); | |
3577 | cep = CONSTRUCTOR_ELT (*valp, i); | |
3578 | gcc_assert (TREE_CODE (cep->index) != RANGE_EXPR); | |
3579 | } | |
3580 | else | |
3581 | { | |
3582 | gcc_assert (TREE_CODE (index) == FIELD_DECL); | |
88504f34 NS |
3583 | |
3584 | /* We must keep the CONSTRUCTOR's ELTS in FIELD order. | |
3585 | Usually we meet initializers in that order, but it is | |
3586 | possible for base types to be placed not in program | |
3587 | order. */ | |
3588 | tree fields = TYPE_FIELDS (DECL_CONTEXT (index)); | |
3589 | unsigned HOST_WIDE_INT idx; | |
3590 | ||
5c97093b JM |
3591 | if (code == UNION_TYPE && CONSTRUCTOR_NELTS (*valp) |
3592 | && CONSTRUCTOR_ELT (*valp, 0)->index != index) | |
3593 | /* Changing active member. */ | |
3594 | vec_safe_truncate (CONSTRUCTOR_ELTS (*valp), 0); | |
3595 | ||
88504f34 | 3596 | for (idx = 0; |
ceaaf873 | 3597 | vec_safe_iterate (CONSTRUCTOR_ELTS (*valp), idx, &cep); |
88504f34 | 3598 | idx++, fields = DECL_CHAIN (fields)) |
ceaaf873 | 3599 | { |
88504f34 NS |
3600 | if (index == cep->index) |
3601 | goto found; | |
3602 | ||
3603 | /* The field we're initializing must be on the field | |
3604 | list. Look to see if it is present before the | |
3605 | field the current ELT initializes. */ | |
3606 | for (; fields != cep->index; fields = DECL_CHAIN (fields)) | |
3607 | if (index == fields) | |
3608 | goto insert; | |
ceaaf873 | 3609 | } |
88504f34 NS |
3610 | |
3611 | /* We fell off the end of the CONSTRUCTOR, so insert a new | |
3612 | entry at the end. */ | |
3613 | insert: | |
3614 | { | |
3615 | constructor_elt ce = { index, NULL_TREE }; | |
3616 | ||
3617 | vec_safe_insert (CONSTRUCTOR_ELTS (*valp), idx, ce); | |
3618 | cep = CONSTRUCTOR_ELT (*valp, idx); | |
3619 | } | |
3620 | found:; | |
ceaaf873 | 3621 | } |
60813a46 JM |
3622 | valp = &cep->value; |
3623 | } | |
3624 | release_tree_vector (refs); | |
3625 | ||
acb2970c | 3626 | if (AGGREGATE_TYPE_P (type) || VECTOR_TYPE_P (type)) |
60813a46 JM |
3627 | { |
3628 | /* Create a new CONSTRUCTOR in case evaluation of the initializer | |
3629 | wants to modify it. */ | |
acb2970c | 3630 | if (*valp == NULL_TREE) |
73a84269 | 3631 | { |
664beaf2 JJ |
3632 | *valp = build_constructor (type, NULL); |
3633 | CONSTRUCTOR_NO_IMPLICIT_ZERO (*valp) = no_zero_init; | |
73a84269 | 3634 | } |
664beaf2 JJ |
3635 | else if (TREE_CODE (*valp) == PTRMEM_CST) |
3636 | *valp = cplus_expand_constant (*valp); | |
3637 | new_ctx.ctor = *valp; | |
60813a46 JM |
3638 | new_ctx.object = target; |
3639 | } | |
3640 | ||
58cc255c JM |
3641 | init = cxx_eval_constant_expression (&new_ctx, init, false, |
3642 | non_constant_p, overflow_p); | |
7574c916 | 3643 | /* Don't share a CONSTRUCTOR that might be changed later. */ |
0146e25f | 3644 | init = unshare_constructor (init); |
60813a46 | 3645 | if (target == object) |
d96e8407 JM |
3646 | /* The hash table might have moved since the get earlier. */ |
3647 | valp = ctx->values->get (object); | |
3648 | ||
3649 | if (TREE_CODE (init) == CONSTRUCTOR) | |
acb2970c | 3650 | { |
d96e8407 JM |
3651 | /* An outer ctx->ctor might be pointing to *valp, so replace |
3652 | its contents. */ | |
3653 | CONSTRUCTOR_ELTS (*valp) = CONSTRUCTOR_ELTS (init); | |
3654 | TREE_CONSTANT (*valp) = TREE_CONSTANT (init); | |
3655 | TREE_SIDE_EFFECTS (*valp) = TREE_SIDE_EFFECTS (init); | |
3ae9a8b7 JM |
3656 | CONSTRUCTOR_NO_IMPLICIT_ZERO (*valp) |
3657 | = CONSTRUCTOR_NO_IMPLICIT_ZERO (init); | |
acb2970c | 3658 | } |
60813a46 | 3659 | else |
d96e8407 | 3660 | *valp = init; |
2d63bc39 | 3661 | |
d96e8407 JM |
3662 | /* Update TREE_CONSTANT and TREE_SIDE_EFFECTS on enclosing |
3663 | CONSTRUCTORs, if any. */ | |
3664 | tree elt; | |
3665 | unsigned i; | |
3666 | bool c = TREE_CONSTANT (init); | |
3667 | bool s = TREE_SIDE_EFFECTS (init); | |
3668 | if (!c || s) | |
3669 | FOR_EACH_VEC_SAFE_ELT (ctors, i, elt) | |
3670 | { | |
3671 | if (!c) | |
3672 | TREE_CONSTANT (elt) = false; | |
3673 | if (s) | |
3674 | TREE_SIDE_EFFECTS (elt) = true; | |
3675 | } | |
2d63bc39 | 3676 | release_tree_vector (ctors); |
60813a46 JM |
3677 | |
3678 | if (*non_constant_p) | |
3679 | return t; | |
92a596e8 | 3680 | else if (lval) |
60813a46 JM |
3681 | return target; |
3682 | else | |
3bdf0a9b | 3683 | return init; |
60813a46 JM |
3684 | } |
3685 | ||
3686 | /* Evaluate a ++ or -- expression. */ | |
3687 | ||
3688 | static tree | |
3689 | cxx_eval_increment_expression (const constexpr_ctx *ctx, tree t, | |
92a596e8 | 3690 | bool lval, |
60813a46 JM |
3691 | bool *non_constant_p, bool *overflow_p) |
3692 | { | |
3693 | enum tree_code code = TREE_CODE (t); | |
3694 | tree type = TREE_TYPE (t); | |
3695 | tree op = TREE_OPERAND (t, 0); | |
3696 | tree offset = TREE_OPERAND (t, 1); | |
3697 | gcc_assert (TREE_CONSTANT (offset)); | |
3698 | ||
3699 | /* The operand as an lvalue. */ | |
2b3ab879 | 3700 | op = cxx_eval_constant_expression (ctx, op, true, |
5a804683 | 3701 | non_constant_p, overflow_p); |
60813a46 JM |
3702 | |
3703 | /* The operand as an rvalue. */ | |
84dd815f JM |
3704 | tree val |
3705 | = cxx_eval_constant_expression (ctx, op, false, | |
3706 | non_constant_p, overflow_p); | |
caee690e JM |
3707 | /* Don't VERIFY_CONSTANT if this might be dealing with a pointer to |
3708 | a local array in a constexpr function. */ | |
3709 | bool ptr = POINTER_TYPE_P (TREE_TYPE (val)); | |
3710 | if (!ptr) | |
3711 | VERIFY_CONSTANT (val); | |
60813a46 JM |
3712 | |
3713 | /* The modified value. */ | |
3714 | bool inc = (code == PREINCREMENT_EXPR || code == POSTINCREMENT_EXPR); | |
ac2f8d26 JM |
3715 | tree mod; |
3716 | if (POINTER_TYPE_P (type)) | |
3717 | { | |
3718 | /* The middle end requires pointers to use POINTER_PLUS_EXPR. */ | |
3719 | offset = convert_to_ptrofftype (offset); | |
3720 | if (!inc) | |
3721 | offset = fold_build1 (NEGATE_EXPR, TREE_TYPE (offset), offset); | |
3722 | mod = fold_build2 (POINTER_PLUS_EXPR, type, val, offset); | |
3723 | } | |
3724 | else | |
3725 | mod = fold_build2 (inc ? PLUS_EXPR : MINUS_EXPR, type, val, offset); | |
caee690e JM |
3726 | if (!ptr) |
3727 | VERIFY_CONSTANT (mod); | |
60813a46 JM |
3728 | |
3729 | /* Storing the modified value. */ | |
3730 | tree store = build2 (MODIFY_EXPR, type, op, mod); | |
2b3ab879 | 3731 | cxx_eval_constant_expression (ctx, store, |
5a804683 | 3732 | true, non_constant_p, overflow_p); |
60813a46 JM |
3733 | |
3734 | /* And the value of the expression. */ | |
3735 | if (code == PREINCREMENT_EXPR || code == PREDECREMENT_EXPR) | |
3736 | { | |
3737 | /* Prefix ops are lvalues. */ | |
92a596e8 | 3738 | if (lval) |
60813a46 JM |
3739 | return op; |
3740 | else | |
3741 | /* But we optimize when the caller wants an rvalue. */ | |
3742 | return mod; | |
3743 | } | |
3744 | else | |
3745 | /* Postfix ops are rvalues. */ | |
3746 | return val; | |
3747 | } | |
3748 | ||
56632b27 JM |
3749 | /* Predicates for the meaning of *jump_target. */ |
3750 | ||
3751 | static bool | |
3752 | returns (tree *jump_target) | |
3753 | { | |
3754 | return *jump_target | |
d49318d9 PC |
3755 | && (TREE_CODE (*jump_target) == RETURN_EXPR |
3756 | || (TREE_CODE (*jump_target) == LABEL_DECL | |
3757 | && LABEL_DECL_CDTOR (*jump_target))); | |
56632b27 JM |
3758 | } |
3759 | ||
3760 | static bool | |
3761 | breaks (tree *jump_target) | |
3762 | { | |
3763 | return *jump_target | |
06ec22b7 JM |
3764 | && ((TREE_CODE (*jump_target) == LABEL_DECL |
3765 | && LABEL_DECL_BREAK (*jump_target)) | |
3766 | || TREE_CODE (*jump_target) == EXIT_EXPR); | |
56632b27 JM |
3767 | } |
3768 | ||
3769 | static bool | |
3770 | continues (tree *jump_target) | |
3771 | { | |
3772 | return *jump_target | |
3773 | && TREE_CODE (*jump_target) == LABEL_DECL | |
3774 | && LABEL_DECL_CONTINUE (*jump_target); | |
3775 | } | |
3776 | ||
3777 | static bool | |
3778 | switches (tree *jump_target) | |
3779 | { | |
3780 | return *jump_target | |
3781 | && TREE_CODE (*jump_target) == INTEGER_CST; | |
3782 | } | |
3783 | ||
3784 | /* Subroutine of cxx_eval_statement_list. Determine whether the statement | |
4b390698 JJ |
3785 | STMT matches *jump_target. If we're looking for a case label and we see |
3786 | the default label, note it in ctx->css_state. */ | |
56632b27 JM |
3787 | |
3788 | static bool | |
4b390698 | 3789 | label_matches (const constexpr_ctx *ctx, tree *jump_target, tree stmt) |
56632b27 | 3790 | { |
56632b27 JM |
3791 | switch (TREE_CODE (*jump_target)) |
3792 | { | |
3793 | case LABEL_DECL: | |
3794 | if (TREE_CODE (stmt) == LABEL_EXPR | |
3795 | && LABEL_EXPR_LABEL (stmt) == *jump_target) | |
3796 | return true; | |
3797 | break; | |
3798 | ||
3799 | case INTEGER_CST: | |
3800 | if (TREE_CODE (stmt) == CASE_LABEL_EXPR) | |
3801 | { | |
4b390698 | 3802 | gcc_assert (ctx->css_state != NULL); |
56632b27 | 3803 | if (!CASE_LOW (stmt)) |
4b390698 JJ |
3804 | { |
3805 | /* default: should appear just once in a SWITCH_EXPR | |
3806 | body (excluding nested SWITCH_EXPR). */ | |
3807 | gcc_assert (*ctx->css_state != css_default_seen); | |
3808 | /* When evaluating SWITCH_EXPR body for the second time, | |
3809 | return true for the default: label. */ | |
3810 | if (*ctx->css_state == css_default_processing) | |
3811 | return true; | |
3812 | *ctx->css_state = css_default_seen; | |
3813 | } | |
385ed708 JJ |
3814 | else if (CASE_HIGH (stmt)) |
3815 | { | |
3816 | if (tree_int_cst_le (CASE_LOW (stmt), *jump_target) | |
3817 | && tree_int_cst_le (*jump_target, CASE_HIGH (stmt))) | |
3818 | return true; | |
3819 | } | |
56632b27 JM |
3820 | else if (tree_int_cst_equal (*jump_target, CASE_LOW (stmt))) |
3821 | return true; | |
3822 | } | |
3823 | break; | |
3824 | ||
3825 | default: | |
3826 | gcc_unreachable (); | |
3827 | } | |
3828 | return false; | |
3829 | } | |
3830 | ||
3831 | /* Evaluate a STATEMENT_LIST for side-effects. Handles various jump | |
3832 | semantics, for switch, break, continue, and return. */ | |
3833 | ||
3834 | static tree | |
3835 | cxx_eval_statement_list (const constexpr_ctx *ctx, tree t, | |
56632b27 JM |
3836 | bool *non_constant_p, bool *overflow_p, |
3837 | tree *jump_target) | |
3838 | { | |
3839 | tree_stmt_iterator i; | |
58611fb6 | 3840 | tree local_target; |
345edb37 JJ |
3841 | /* In a statement-expression we want to return the last value. |
3842 | For empty statement expression return void_node. */ | |
3843 | tree r = void_node; | |
58611fb6 JM |
3844 | if (!jump_target) |
3845 | { | |
3846 | local_target = NULL_TREE; | |
3847 | jump_target = &local_target; | |
3848 | } | |
56632b27 JM |
3849 | for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i)) |
3850 | { | |
56632b27 | 3851 | tree stmt = tsi_stmt (i); |
58611fb6 JM |
3852 | r = cxx_eval_constant_expression (ctx, stmt, false, |
3853 | non_constant_p, overflow_p, | |
3854 | jump_target); | |
56632b27 JM |
3855 | if (*non_constant_p) |
3856 | break; | |
3857 | if (returns (jump_target) || breaks (jump_target)) | |
3858 | break; | |
3859 | } | |
96a95ac1 AO |
3860 | /* Make sure we don't use the "result" of a debug-only marker. That |
3861 | would be wrong. We should be using the result of the previous | |
3862 | statement, or NULL if there isn't one. In practice, this should | |
3863 | never happen: the statement after the marker should override the | |
3864 | result of the marker, so its value shouldn't survive in R. Now, | |
3865 | should that ever change, we'll need some fixing here to stop | |
3866 | markers from modifying the generated executable code. */ | |
3867 | gcc_checking_assert (!r || TREE_CODE (r) != DEBUG_BEGIN_STMT); | |
58611fb6 | 3868 | return r; |
56632b27 JM |
3869 | } |
3870 | ||
3871 | /* Evaluate a LOOP_EXPR for side-effects. Handles break and return | |
3872 | semantics; continue semantics are covered by cxx_eval_statement_list. */ | |
3873 | ||
3874 | static tree | |
3875 | cxx_eval_loop_expr (const constexpr_ctx *ctx, tree t, | |
56632b27 JM |
3876 | bool *non_constant_p, bool *overflow_p, |
3877 | tree *jump_target) | |
3878 | { | |
39dce2b7 JM |
3879 | constexpr_ctx new_ctx = *ctx; |
3880 | ||
56632b27 | 3881 | tree body = TREE_OPERAND (t, 0); |
5ec2cd9f | 3882 | int count = 0; |
d259b234 | 3883 | do |
56632b27 | 3884 | { |
39dce2b7 JM |
3885 | hash_set<tree> save_exprs; |
3886 | new_ctx.save_exprs = &save_exprs; | |
3887 | ||
06ec22b7 JM |
3888 | cxx_eval_constant_expression (&new_ctx, body, /*lval*/false, |
3889 | non_constant_p, overflow_p, jump_target); | |
39dce2b7 JM |
3890 | |
3891 | /* Forget saved values of SAVE_EXPRs. */ | |
3892 | for (hash_set<tree>::iterator iter = save_exprs.begin(); | |
3893 | iter != save_exprs.end(); ++iter) | |
3894 | new_ctx.values->remove (*iter); | |
5ec2cd9f JM |
3895 | if (++count >= constexpr_loop_limit) |
3896 | { | |
3897 | if (!ctx->quiet) | |
3898 | error_at (EXPR_LOC_OR_LOC (t, input_location), | |
84fa214d | 3899 | "%<constexpr%> loop iteration count exceeds limit of %d " |
5ec2cd9f JM |
3900 | "(use -fconstexpr-loop-limit= to increase the limit)", |
3901 | constexpr_loop_limit); | |
3902 | *non_constant_p = true; | |
3903 | break; | |
3904 | } | |
56632b27 | 3905 | } |
4b390698 JJ |
3906 | while (!returns (jump_target) |
3907 | && !breaks (jump_target) | |
3908 | && !switches (jump_target) | |
3909 | && !*non_constant_p); | |
d259b234 | 3910 | |
56632b27 JM |
3911 | if (breaks (jump_target)) |
3912 | *jump_target = NULL_TREE; | |
39dce2b7 | 3913 | |
56632b27 JM |
3914 | return NULL_TREE; |
3915 | } | |
3916 | ||
3917 | /* Evaluate a SWITCH_EXPR for side-effects. Handles switch and break jump | |
3918 | semantics. */ | |
3919 | ||
3920 | static tree | |
3921 | cxx_eval_switch_expr (const constexpr_ctx *ctx, tree t, | |
56632b27 JM |
3922 | bool *non_constant_p, bool *overflow_p, |
3923 | tree *jump_target) | |
3924 | { | |
3925 | tree cond = TREE_OPERAND (t, 0); | |
2b3ab879 | 3926 | cond = cxx_eval_constant_expression (ctx, cond, false, |
5a804683 | 3927 | non_constant_p, overflow_p); |
56632b27 JM |
3928 | VERIFY_CONSTANT (cond); |
3929 | *jump_target = cond; | |
3930 | ||
3931 | tree body = TREE_OPERAND (t, 1); | |
4b390698 JJ |
3932 | constexpr_ctx new_ctx = *ctx; |
3933 | constexpr_switch_state css = css_default_not_seen; | |
3934 | new_ctx.css_state = &css; | |
3935 | cxx_eval_constant_expression (&new_ctx, body, false, | |
3936 | non_constant_p, overflow_p, jump_target); | |
3937 | if (switches (jump_target) && css == css_default_seen) | |
3938 | { | |
3939 | /* If the SWITCH_EXPR body has default: label, process it once again, | |
3940 | this time instructing label_matches to return true for default: | |
3941 | label on switches (jump_target). */ | |
3942 | css = css_default_processing; | |
3943 | cxx_eval_constant_expression (&new_ctx, body, false, | |
3944 | non_constant_p, overflow_p, jump_target); | |
3945 | } | |
56632b27 JM |
3946 | if (breaks (jump_target) || switches (jump_target)) |
3947 | *jump_target = NULL_TREE; | |
3948 | return NULL_TREE; | |
3949 | } | |
3950 | ||
89262ec6 JM |
3951 | /* Find the object of TYPE under initialization in CTX. */ |
3952 | ||
3953 | static tree | |
3954 | lookup_placeholder (const constexpr_ctx *ctx, bool lval, tree type) | |
3955 | { | |
fbd603c4 | 3956 | if (!ctx) |
89262ec6 JM |
3957 | return NULL_TREE; |
3958 | ||
3959 | /* We could use ctx->object unconditionally, but using ctx->ctor when we | |
3960 | can is a minor optimization. */ | |
fbd603c4 | 3961 | if (!lval && ctx->ctor && same_type_p (TREE_TYPE (ctx->ctor), type)) |
89262ec6 JM |
3962 | return ctx->ctor; |
3963 | ||
fbd603c4 JM |
3964 | if (!ctx->object) |
3965 | return NULL_TREE; | |
3966 | ||
89262ec6 JM |
3967 | /* Since an object cannot have a field of its own type, we can search outward |
3968 | from ctx->object to find the unique containing object of TYPE. */ | |
3969 | tree ob = ctx->object; | |
3970 | while (ob) | |
3971 | { | |
3972 | if (same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (ob), type)) | |
3973 | break; | |
3974 | if (handled_component_p (ob)) | |
3975 | ob = TREE_OPERAND (ob, 0); | |
3976 | else | |
3977 | ob = NULL_TREE; | |
3978 | } | |
3979 | ||
3980 | return ob; | |
3981 | } | |
3982 | ||
2d76680f PC |
3983 | /* Attempt to reduce the expression T to a constant value. |
3984 | On failure, issue diagnostic and return error_mark_node. */ | |
3985 | /* FIXME unify with c_fully_fold */ | |
60813a46 | 3986 | /* FIXME overflow_p is too global */ |
2d76680f PC |
3987 | |
3988 | static tree | |
3e605b20 | 3989 | cxx_eval_constant_expression (const constexpr_ctx *ctx, tree t, |
92a596e8 | 3990 | bool lval, |
56632b27 JM |
3991 | bool *non_constant_p, bool *overflow_p, |
3992 | tree *jump_target) | |
2d76680f | 3993 | { |
3e605b20 | 3994 | constexpr_ctx new_ctx; |
2d76680f PC |
3995 | tree r = t; |
3996 | ||
4b390698 JJ |
3997 | if (jump_target && *jump_target) |
3998 | { | |
3999 | /* If we are jumping, ignore all statements/expressions except those | |
4000 | that could have LABEL_EXPR or CASE_LABEL_EXPR in their bodies. */ | |
4001 | switch (TREE_CODE (t)) | |
4002 | { | |
4003 | case BIND_EXPR: | |
4004 | case STATEMENT_LIST: | |
4005 | case LOOP_EXPR: | |
4006 | case COND_EXPR: | |
4007 | break; | |
4008 | case LABEL_EXPR: | |
4009 | case CASE_LABEL_EXPR: | |
4010 | if (label_matches (ctx, jump_target, t)) | |
4011 | /* Found it. */ | |
4012 | *jump_target = NULL_TREE; | |
4013 | return NULL_TREE; | |
4014 | default: | |
4015 | return NULL_TREE; | |
4016 | } | |
4017 | } | |
2d76680f PC |
4018 | if (t == error_mark_node) |
4019 | { | |
4020 | *non_constant_p = true; | |
4021 | return t; | |
4022 | } | |
4023 | if (CONSTANT_CLASS_P (t)) | |
4024 | { | |
61637db3 JJ |
4025 | if (TREE_OVERFLOW (t)) |
4026 | { | |
4027 | if (!ctx->quiet) | |
4028 | permerror (input_location, "overflow in constant expression"); | |
4029 | if (!flag_permissive || ctx->quiet) | |
4030 | *overflow_p = true; | |
4031 | } | |
8bada5cd MS |
4032 | |
4033 | if (TREE_CODE (t) == INTEGER_CST | |
4034 | && TREE_CODE (TREE_TYPE (t)) == POINTER_TYPE | |
4035 | && !integer_zerop (t)) | |
4036 | { | |
4037 | if (!ctx->quiet) | |
4038 | error ("value %qE of type %qT is not a constant expression", | |
4039 | t, TREE_TYPE (t)); | |
4040 | *non_constant_p = true; | |
4041 | } | |
4042 | ||
2d76680f PC |
4043 | return t; |
4044 | } | |
2d76680f | 4045 | |
8bada5cd MS |
4046 | tree_code tcode = TREE_CODE (t); |
4047 | switch (tcode) | |
2d76680f | 4048 | { |
60813a46 | 4049 | case RESULT_DECL: |
92a596e8 | 4050 | if (lval) |
60813a46 JM |
4051 | return t; |
4052 | /* We ask for an rvalue for the RESULT_DECL when indirecting | |
bf66b9b4 AH |
4053 | through an invisible reference, or in named return value |
4054 | optimization. */ | |
60813a46 JM |
4055 | return (*ctx->values->get (t)); |
4056 | ||
2d76680f | 4057 | case VAR_DECL: |
70f40fea | 4058 | if (DECL_HAS_VALUE_EXPR_P (t)) |
98e5a19a JM |
4059 | return cxx_eval_constant_expression (ctx, DECL_VALUE_EXPR (t), |
4060 | lval, non_constant_p, overflow_p); | |
191816a3 | 4061 | /* fall through */ |
7c83622c JM |
4062 | case CONST_DECL: |
4063 | /* We used to not check lval for CONST_DECL, but darwin.c uses | |
4064 | CONST_DECL for aggregate constants. */ | |
92a596e8 | 4065 | if (lval) |
2d76680f | 4066 | return t; |
f4fce183 JM |
4067 | if (COMPLETE_TYPE_P (TREE_TYPE (t)) |
4068 | && is_really_empty_class (TREE_TYPE (t))) | |
7dc2b4a2 JM |
4069 | { |
4070 | /* If the class is empty, we aren't actually loading anything. */ | |
4071 | r = build_constructor (TREE_TYPE (t), NULL); | |
4072 | TREE_CONSTANT (r) = true; | |
4073 | } | |
4074 | else if (ctx->strict) | |
69eb4fde JM |
4075 | r = decl_really_constant_value (t); |
4076 | else | |
4077 | r = decl_constant_value (t); | |
2d76680f PC |
4078 | if (TREE_CODE (r) == TARGET_EXPR |
4079 | && TREE_CODE (TARGET_EXPR_INITIAL (r)) == CONSTRUCTOR) | |
4080 | r = TARGET_EXPR_INITIAL (r); | |
56a6f1d3 | 4081 | if (VAR_P (r)) |
3e605b20 | 4082 | if (tree *p = ctx->values->get (r)) |
bd8f5bb2 MP |
4083 | if (*p != NULL_TREE) |
4084 | r = *p; | |
2d76680f PC |
4085 | if (DECL_P (r)) |
4086 | { | |
2b3ab879 | 4087 | if (!ctx->quiet) |
2d76680f PC |
4088 | non_const_var_error (r); |
4089 | *non_constant_p = true; | |
4090 | } | |
4091 | break; | |
4092 | ||
96a95ac1 AO |
4093 | case DEBUG_BEGIN_STMT: |
4094 | /* ??? It might be nice to retain this information somehow, so | |
4095 | as to be able to step into a constexpr function call. */ | |
4096 | /* Fall through. */ | |
4097 | ||
2d76680f PC |
4098 | case FUNCTION_DECL: |
4099 | case TEMPLATE_DECL: | |
4100 | case LABEL_DECL: | |
56632b27 JM |
4101 | case LABEL_EXPR: |
4102 | case CASE_LABEL_EXPR: | |
4b390698 | 4103 | case PREDICT_EXPR: |
2d76680f PC |
4104 | return t; |
4105 | ||
4106 | case PARM_DECL: | |
0567dcd2 | 4107 | if (lval && TREE_CODE (TREE_TYPE (t)) != REFERENCE_TYPE) |
60813a46 JM |
4108 | /* glvalue use. */; |
4109 | else if (tree *p = ctx->values->get (r)) | |
4110 | r = *p; | |
92a596e8 | 4111 | else if (lval) |
2d76680f | 4112 | /* Defer in case this is only used for its type. */; |
f2acb8ad JM |
4113 | else if (TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE) |
4114 | /* Defer, there's no lvalue->rvalue conversion. */; | |
1c2f613f JJ |
4115 | else if (COMPLETE_TYPE_P (TREE_TYPE (t)) |
4116 | && is_really_empty_class (TREE_TYPE (t))) | |
052beba4 JM |
4117 | { |
4118 | /* If the class is empty, we aren't actually loading anything. */ | |
4119 | r = build_constructor (TREE_TYPE (t), NULL); | |
4120 | TREE_CONSTANT (r) = true; | |
4121 | } | |
2d76680f PC |
4122 | else |
4123 | { | |
2b3ab879 | 4124 | if (!ctx->quiet) |
2d76680f PC |
4125 | error ("%qE is not a constant expression", t); |
4126 | *non_constant_p = true; | |
4127 | } | |
4128 | break; | |
4129 | ||
4130 | case CALL_EXPR: | |
4131 | case AGGR_INIT_EXPR: | |
92a596e8 | 4132 | r = cxx_eval_call_expression (ctx, t, lval, |
2d76680f PC |
4133 | non_constant_p, overflow_p); |
4134 | break; | |
4135 | ||
60813a46 JM |
4136 | case DECL_EXPR: |
4137 | { | |
4138 | r = DECL_EXPR_DECL (t); | |
4139 | if (AGGREGATE_TYPE_P (TREE_TYPE (r)) | |
4140 | || VECTOR_TYPE_P (TREE_TYPE (r))) | |
4141 | { | |
4142 | new_ctx = *ctx; | |
4143 | new_ctx.object = r; | |
4144 | new_ctx.ctor = build_constructor (TREE_TYPE (r), NULL); | |
4145 | CONSTRUCTOR_NO_IMPLICIT_ZERO (new_ctx.ctor) = true; | |
4146 | new_ctx.values->put (r, new_ctx.ctor); | |
4147 | ctx = &new_ctx; | |
4148 | } | |
4149 | ||
4150 | if (tree init = DECL_INITIAL (r)) | |
4151 | { | |
4152 | init = cxx_eval_constant_expression (ctx, init, | |
2b3ab879 | 4153 | false, |
5a804683 | 4154 | non_constant_p, overflow_p); |
7f0e23e9 | 4155 | /* Don't share a CONSTRUCTOR that might be changed. */ |
0146e25f | 4156 | init = unshare_constructor (init); |
60813a46 JM |
4157 | ctx->values->put (r, init); |
4158 | } | |
4159 | else if (ctx == &new_ctx) | |
4160 | /* We gave it a CONSTRUCTOR above. */; | |
4161 | else | |
4162 | ctx->values->put (r, NULL_TREE); | |
4163 | } | |
4164 | break; | |
4165 | ||
2d76680f PC |
4166 | case TARGET_EXPR: |
4167 | if (!literal_type_p (TREE_TYPE (t))) | |
4168 | { | |
2b3ab879 | 4169 | if (!ctx->quiet) |
2d76680f PC |
4170 | { |
4171 | error ("temporary of non-literal type %qT in a " | |
4172 | "constant expression", TREE_TYPE (t)); | |
4173 | explain_non_literal_class (TREE_TYPE (t)); | |
4174 | } | |
4175 | *non_constant_p = true; | |
4176 | break; | |
4177 | } | |
3e605b20 JM |
4178 | if ((AGGREGATE_TYPE_P (TREE_TYPE (t)) || VECTOR_TYPE_P (TREE_TYPE (t)))) |
4179 | { | |
4180 | /* We're being expanded without an explicit target, so start | |
4181 | initializing a new object; expansion with an explicit target | |
4182 | strips the TARGET_EXPR before we get here. */ | |
4183 | new_ctx = *ctx; | |
4184 | new_ctx.ctor = build_constructor (TREE_TYPE (t), NULL); | |
4185 | CONSTRUCTOR_NO_IMPLICIT_ZERO (new_ctx.ctor) = true; | |
4186 | new_ctx.object = TARGET_EXPR_SLOT (t); | |
4187 | ctx->values->put (new_ctx.object, new_ctx.ctor); | |
4188 | ctx = &new_ctx; | |
4189 | } | |
92a596e8 | 4190 | /* Pass false for 'lval' because this indicates |
2d76680f | 4191 | initialization of a temporary. */ |
3e605b20 | 4192 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), |
2b3ab879 | 4193 | false, |
5a804683 | 4194 | non_constant_p, overflow_p); |
2d76680f PC |
4195 | if (!*non_constant_p) |
4196 | /* Adjust the type of the result to the type of the temporary. */ | |
4197 | r = adjust_temp_type (TREE_TYPE (t), r); | |
92a596e8 | 4198 | if (lval) |
f2acb8ad JM |
4199 | { |
4200 | tree slot = TARGET_EXPR_SLOT (t); | |
0146e25f | 4201 | r = unshare_constructor (r); |
f2acb8ad JM |
4202 | ctx->values->put (slot, r); |
4203 | return slot; | |
4204 | } | |
2d76680f PC |
4205 | break; |
4206 | ||
60813a46 | 4207 | case INIT_EXPR: |
60813a46 | 4208 | case MODIFY_EXPR: |
4b390698 | 4209 | gcc_assert (jump_target == NULL || *jump_target == NULL_TREE); |
92a596e8 | 4210 | r = cxx_eval_store_expression (ctx, t, lval, |
60813a46 JM |
4211 | non_constant_p, overflow_p); |
4212 | break; | |
4213 | ||
2d76680f | 4214 | case SCOPE_REF: |
3e605b20 | 4215 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), |
92a596e8 | 4216 | lval, |
5a804683 | 4217 | non_constant_p, overflow_p); |
2d76680f PC |
4218 | break; |
4219 | ||
4220 | case RETURN_EXPR: | |
75e0295b MP |
4221 | if (TREE_OPERAND (t, 0) != NULL_TREE) |
4222 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), | |
4223 | lval, | |
4224 | non_constant_p, overflow_p); | |
56632b27 JM |
4225 | *jump_target = t; |
4226 | break; | |
4227 | ||
cabaf50a JM |
4228 | case SAVE_EXPR: |
4229 | /* Avoid evaluating a SAVE_EXPR more than once. */ | |
4230 | if (tree *p = ctx->values->get (t)) | |
4231 | r = *p; | |
4232 | else | |
4233 | { | |
12d9ce19 | 4234 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), false, |
cabaf50a JM |
4235 | non_constant_p, overflow_p); |
4236 | ctx->values->put (t, r); | |
39dce2b7 JM |
4237 | if (ctx->save_exprs) |
4238 | ctx->save_exprs->add (t); | |
cabaf50a JM |
4239 | } |
4240 | break; | |
4241 | ||
2d76680f PC |
4242 | case NON_LVALUE_EXPR: |
4243 | case TRY_CATCH_EXPR: | |
769430b2 | 4244 | case TRY_BLOCK: |
2d76680f PC |
4245 | case CLEANUP_POINT_EXPR: |
4246 | case MUST_NOT_THROW_EXPR: | |
60813a46 JM |
4247 | case EXPR_STMT: |
4248 | case EH_SPEC_BLOCK: | |
3e605b20 | 4249 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), |
92a596e8 | 4250 | lval, |
56632b27 JM |
4251 | non_constant_p, overflow_p, |
4252 | jump_target); | |
2d76680f PC |
4253 | break; |
4254 | ||
769430b2 JM |
4255 | case TRY_FINALLY_EXPR: |
4256 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval, | |
4257 | non_constant_p, overflow_p, | |
4258 | jump_target); | |
4259 | if (!*non_constant_p) | |
4260 | /* Also evaluate the cleanup. */ | |
4261 | cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), true, | |
4262 | non_constant_p, overflow_p, | |
4263 | jump_target); | |
4264 | break; | |
4265 | ||
2d76680f PC |
4266 | /* These differ from cxx_eval_unary_expression in that this doesn't |
4267 | check for a constant operand or result; an address can be | |
4268 | constant without its operand being, and vice versa. */ | |
cda0a029 | 4269 | case MEM_REF: |
2d76680f | 4270 | case INDIRECT_REF: |
92a596e8 | 4271 | r = cxx_eval_indirect_ref (ctx, t, lval, |
2d76680f PC |
4272 | non_constant_p, overflow_p); |
4273 | break; | |
4274 | ||
4275 | case ADDR_EXPR: | |
4276 | { | |
4277 | tree oldop = TREE_OPERAND (t, 0); | |
3e605b20 | 4278 | tree op = cxx_eval_constant_expression (ctx, oldop, |
92a596e8 | 4279 | /*lval*/true, |
5a804683 | 4280 | non_constant_p, overflow_p); |
2d76680f PC |
4281 | /* Don't VERIFY_CONSTANT here. */ |
4282 | if (*non_constant_p) | |
4283 | return t; | |
f2acb8ad | 4284 | gcc_checking_assert (TREE_CODE (op) != CONSTRUCTOR); |
2d76680f PC |
4285 | /* This function does more aggressive folding than fold itself. */ |
4286 | r = build_fold_addr_expr_with_type (op, TREE_TYPE (t)); | |
4287 | if (TREE_CODE (r) == ADDR_EXPR && TREE_OPERAND (r, 0) == oldop) | |
4288 | return t; | |
4289 | break; | |
4290 | } | |
4291 | ||
4292 | case REALPART_EXPR: | |
4293 | case IMAGPART_EXPR: | |
87713c6a JJ |
4294 | if (lval) |
4295 | { | |
4296 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval, | |
4297 | non_constant_p, overflow_p); | |
4298 | if (r == error_mark_node) | |
4299 | ; | |
4300 | else if (r == TREE_OPERAND (t, 0)) | |
4301 | r = t; | |
4302 | else | |
4303 | r = fold_build1 (TREE_CODE (t), TREE_TYPE (t), r); | |
4304 | break; | |
4305 | } | |
4306 | /* FALLTHRU */ | |
2d76680f PC |
4307 | case CONJ_EXPR: |
4308 | case FIX_TRUNC_EXPR: | |
4309 | case FLOAT_EXPR: | |
4310 | case NEGATE_EXPR: | |
4311 | case ABS_EXPR: | |
4312 | case BIT_NOT_EXPR: | |
4313 | case TRUTH_NOT_EXPR: | |
4314 | case FIXED_CONVERT_EXPR: | |
92a596e8 | 4315 | r = cxx_eval_unary_expression (ctx, t, lval, |
2d76680f PC |
4316 | non_constant_p, overflow_p); |
4317 | break; | |
4318 | ||
4319 | case SIZEOF_EXPR: | |
cda0a029 | 4320 | r = fold_sizeof_expr (t); |
2d76680f PC |
4321 | VERIFY_CONSTANT (r); |
4322 | break; | |
4323 | ||
4324 | case COMPOUND_EXPR: | |
4325 | { | |
4326 | /* check_return_expr sometimes wraps a TARGET_EXPR in a | |
4327 | COMPOUND_EXPR; don't get confused. Also handle EMPTY_CLASS_EXPR | |
4328 | introduced by build_call_a. */ | |
4329 | tree op0 = TREE_OPERAND (t, 0); | |
4330 | tree op1 = TREE_OPERAND (t, 1); | |
4331 | STRIP_NOPS (op1); | |
4332 | if ((TREE_CODE (op0) == TARGET_EXPR && op1 == TARGET_EXPR_SLOT (op0)) | |
4333 | || TREE_CODE (op1) == EMPTY_CLASS_EXPR) | |
2b3ab879 | 4334 | r = cxx_eval_constant_expression (ctx, op0, |
92a596e8 | 4335 | lval, non_constant_p, overflow_p, |
56632b27 | 4336 | jump_target); |
2d76680f PC |
4337 | else |
4338 | { | |
4339 | /* Check that the LHS is constant and then discard it. */ | |
2b3ab879 | 4340 | cxx_eval_constant_expression (ctx, op0, |
12d9ce19 | 4341 | true, non_constant_p, overflow_p, |
56632b27 | 4342 | jump_target); |
06ec22b7 JM |
4343 | if (*non_constant_p) |
4344 | return t; | |
2d76680f | 4345 | op1 = TREE_OPERAND (t, 1); |
2b3ab879 | 4346 | r = cxx_eval_constant_expression (ctx, op1, |
92a596e8 | 4347 | lval, non_constant_p, overflow_p, |
56632b27 | 4348 | jump_target); |
2d76680f PC |
4349 | } |
4350 | } | |
4351 | break; | |
4352 | ||
4353 | case POINTER_PLUS_EXPR: | |
1af4ebf5 | 4354 | case POINTER_DIFF_EXPR: |
2d76680f PC |
4355 | case PLUS_EXPR: |
4356 | case MINUS_EXPR: | |
4357 | case MULT_EXPR: | |
4358 | case TRUNC_DIV_EXPR: | |
4359 | case CEIL_DIV_EXPR: | |
4360 | case FLOOR_DIV_EXPR: | |
4361 | case ROUND_DIV_EXPR: | |
4362 | case TRUNC_MOD_EXPR: | |
4363 | case CEIL_MOD_EXPR: | |
4364 | case ROUND_MOD_EXPR: | |
4365 | case RDIV_EXPR: | |
4366 | case EXACT_DIV_EXPR: | |
4367 | case MIN_EXPR: | |
4368 | case MAX_EXPR: | |
4369 | case LSHIFT_EXPR: | |
4370 | case RSHIFT_EXPR: | |
4371 | case LROTATE_EXPR: | |
4372 | case RROTATE_EXPR: | |
4373 | case BIT_IOR_EXPR: | |
4374 | case BIT_XOR_EXPR: | |
4375 | case BIT_AND_EXPR: | |
4376 | case TRUTH_XOR_EXPR: | |
4377 | case LT_EXPR: | |
4378 | case LE_EXPR: | |
4379 | case GT_EXPR: | |
4380 | case GE_EXPR: | |
4381 | case EQ_EXPR: | |
4382 | case NE_EXPR: | |
4383 | case UNORDERED_EXPR: | |
4384 | case ORDERED_EXPR: | |
4385 | case UNLT_EXPR: | |
4386 | case UNLE_EXPR: | |
4387 | case UNGT_EXPR: | |
4388 | case UNGE_EXPR: | |
4389 | case UNEQ_EXPR: | |
4390 | case LTGT_EXPR: | |
4391 | case RANGE_EXPR: | |
4392 | case COMPLEX_EXPR: | |
92a596e8 | 4393 | r = cxx_eval_binary_expression (ctx, t, lval, |
2d76680f PC |
4394 | non_constant_p, overflow_p); |
4395 | break; | |
4396 | ||
4397 | /* fold can introduce non-IF versions of these; still treat them as | |
4398 | short-circuiting. */ | |
4399 | case TRUTH_AND_EXPR: | |
4400 | case TRUTH_ANDIF_EXPR: | |
3e605b20 | 4401 | r = cxx_eval_logical_expression (ctx, t, boolean_false_node, |
2d76680f | 4402 | boolean_true_node, |
92a596e8 | 4403 | lval, |
2d76680f PC |
4404 | non_constant_p, overflow_p); |
4405 | break; | |
4406 | ||
4407 | case TRUTH_OR_EXPR: | |
4408 | case TRUTH_ORIF_EXPR: | |
3e605b20 | 4409 | r = cxx_eval_logical_expression (ctx, t, boolean_true_node, |
2d76680f | 4410 | boolean_false_node, |
92a596e8 | 4411 | lval, |
2d76680f PC |
4412 | non_constant_p, overflow_p); |
4413 | break; | |
4414 | ||
4415 | case ARRAY_REF: | |
92a596e8 | 4416 | r = cxx_eval_array_reference (ctx, t, lval, |
2d76680f PC |
4417 | non_constant_p, overflow_p); |
4418 | break; | |
4419 | ||
4420 | case COMPONENT_REF: | |
4421 | if (is_overloaded_fn (t)) | |
4422 | { | |
4423 | /* We can only get here in checking mode via | |
4424 | build_non_dependent_expr, because any expression that | |
4425 | calls or takes the address of the function will have | |
4426 | pulled a FUNCTION_DECL out of the COMPONENT_REF. */ | |
2b3ab879 | 4427 | gcc_checking_assert (ctx->quiet || errorcount); |
2d76680f PC |
4428 | *non_constant_p = true; |
4429 | return t; | |
4430 | } | |
92a596e8 | 4431 | r = cxx_eval_component_reference (ctx, t, lval, |
2d76680f PC |
4432 | non_constant_p, overflow_p); |
4433 | break; | |
4434 | ||
4435 | case BIT_FIELD_REF: | |
92a596e8 | 4436 | r = cxx_eval_bit_field_ref (ctx, t, lval, |
2d76680f PC |
4437 | non_constant_p, overflow_p); |
4438 | break; | |
4439 | ||
4440 | case COND_EXPR: | |
4b390698 JJ |
4441 | if (jump_target && *jump_target) |
4442 | { | |
4443 | /* When jumping to a label, the label might be either in the | |
4444 | then or else blocks, so process then block first in skipping | |
4445 | mode first, and if we are still in the skipping mode at its end, | |
4446 | process the else block too. */ | |
4447 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 1), | |
4448 | lval, non_constant_p, overflow_p, | |
4449 | jump_target); | |
4450 | if (*jump_target) | |
4451 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 2), | |
4452 | lval, non_constant_p, overflow_p, | |
4453 | jump_target); | |
4454 | break; | |
4455 | } | |
92a596e8 | 4456 | r = cxx_eval_conditional_expression (ctx, t, lval, |
56632b27 JM |
4457 | non_constant_p, overflow_p, |
4458 | jump_target); | |
2d76680f | 4459 | break; |
f370e36d JJ |
4460 | case VEC_COND_EXPR: |
4461 | r = cxx_eval_vector_conditional_expression (ctx, t, non_constant_p, | |
4462 | overflow_p); | |
4463 | break; | |
2d76680f PC |
4464 | |
4465 | case CONSTRUCTOR: | |
b85a3242 | 4466 | if (TREE_CONSTANT (t)) |
2d63bc39 JM |
4467 | { |
4468 | /* Don't re-process a constant CONSTRUCTOR, but do fold it to | |
4469 | VECTOR_CST if applicable. */ | |
4470 | /* FIXME after GCC 6 branches, make the verify unconditional. */ | |
4471 | if (CHECKING_P) | |
4472 | verify_constructor_flags (t); | |
4473 | else | |
4474 | recompute_constructor_flags (t); | |
4475 | if (TREE_CONSTANT (t)) | |
4476 | return fold (t); | |
4477 | } | |
92a596e8 | 4478 | r = cxx_eval_bare_aggregate (ctx, t, lval, |
2d76680f PC |
4479 | non_constant_p, overflow_p); |
4480 | break; | |
4481 | ||
4482 | case VEC_INIT_EXPR: | |
4483 | /* We can get this in a defaulted constructor for a class with a | |
4484 | non-static data member of array type. Either the initializer will | |
4485 | be NULL, meaning default-initialization, or it will be an lvalue | |
4486 | or xvalue of the same type, meaning direct-initialization from the | |
4487 | corresponding member. */ | |
92a596e8 | 4488 | r = cxx_eval_vec_init (ctx, t, lval, |
2d76680f PC |
4489 | non_constant_p, overflow_p); |
4490 | break; | |
4491 | ||
4492 | case FMA_EXPR: | |
4493 | case VEC_PERM_EXPR: | |
92a596e8 | 4494 | r = cxx_eval_trinary_expression (ctx, t, lval, |
2d76680f PC |
4495 | non_constant_p, overflow_p); |
4496 | break; | |
4497 | ||
4498 | case CONVERT_EXPR: | |
4499 | case VIEW_CONVERT_EXPR: | |
4500 | case NOP_EXPR: | |
cda0a029 | 4501 | case UNARY_PLUS_EXPR: |
2d76680f PC |
4502 | { |
4503 | tree oldop = TREE_OPERAND (t, 0); | |
cda0a029 | 4504 | |
3e605b20 | 4505 | tree op = cxx_eval_constant_expression (ctx, oldop, |
92a596e8 | 4506 | lval, |
5a804683 | 4507 | non_constant_p, overflow_p); |
2d76680f PC |
4508 | if (*non_constant_p) |
4509 | return t; | |
dcdbc004 JM |
4510 | tree type = TREE_TYPE (t); |
4511 | if (TREE_CODE (op) == PTRMEM_CST | |
4512 | && !TYPE_PTRMEM_P (type)) | |
4513 | op = cplus_expand_constant (op); | |
05bf54c3 MP |
4514 | if (TREE_CODE (op) == PTRMEM_CST && tcode == NOP_EXPR) |
4515 | { | |
4516 | if (same_type_ignoring_top_level_qualifiers_p (type, | |
8b8b203a JM |
4517 | TREE_TYPE (op)) |
4518 | || can_convert_qual (type, op)) | |
f9438bbb | 4519 | return cp_fold_convert (type, op); |
05bf54c3 MP |
4520 | else |
4521 | { | |
4522 | if (!ctx->quiet) | |
4523 | error_at (EXPR_LOC_OR_LOC (t, input_location), | |
64d6d399 | 4524 | "a reinterpret_cast is not a constant expression"); |
05bf54c3 MP |
4525 | *non_constant_p = true; |
4526 | return t; | |
4527 | } | |
4528 | } | |
8bada5cd MS |
4529 | |
4530 | if (POINTER_TYPE_P (type) && TREE_CODE (op) == INTEGER_CST) | |
2d76680f | 4531 | { |
8bada5cd MS |
4532 | if (integer_zerop (op)) |
4533 | { | |
4534 | if (TREE_CODE (type) == REFERENCE_TYPE) | |
4535 | { | |
4536 | if (!ctx->quiet) | |
4537 | error_at (EXPR_LOC_OR_LOC (t, input_location), | |
4538 | "dereferencing a null pointer"); | |
4539 | *non_constant_p = true; | |
4540 | return t; | |
4541 | } | |
4542 | else if (TREE_CODE (TREE_TYPE (op)) == POINTER_TYPE) | |
4543 | { | |
4544 | tree from = TREE_TYPE (op); | |
4545 | ||
4546 | if (!can_convert (type, from, tf_none)) | |
4547 | { | |
4548 | if (!ctx->quiet) | |
4549 | error_at (EXPR_LOC_OR_LOC (t, input_location), | |
4550 | "conversion of %qT null pointer to %qT " | |
4551 | "is not a constant expression", | |
4552 | from, type); | |
4553 | *non_constant_p = true; | |
4554 | return t; | |
4555 | } | |
4556 | } | |
4557 | } | |
4558 | else | |
4559 | { | |
4560 | /* This detects for example: | |
4561 | reinterpret_cast<void*>(sizeof 0) | |
4562 | */ | |
4563 | if (!ctx->quiet) | |
4564 | error_at (EXPR_LOC_OR_LOC (t, input_location), | |
4565 | "%<reinterpret_cast<%T>(%E)%> is not " | |
64d6d399 | 4566 | "a constant expression", |
8bada5cd MS |
4567 | type, op); |
4568 | *non_constant_p = true; | |
4569 | return t; | |
4570 | } | |
2d76680f | 4571 | } |
cda0a029 | 4572 | if (op == oldop && tcode != UNARY_PLUS_EXPR) |
2d76680f PC |
4573 | /* We didn't fold at the top so we could check for ptr-int |
4574 | conversion. */ | |
4575 | return fold (t); | |
cda0a029 JM |
4576 | if (tcode == UNARY_PLUS_EXPR) |
4577 | r = fold_convert (TREE_TYPE (t), op); | |
4578 | else | |
4579 | r = fold_build1 (tcode, type, op); | |
2d76680f PC |
4580 | /* Conversion of an out-of-range value has implementation-defined |
4581 | behavior; the language considers it different from arithmetic | |
4582 | overflow, which is undefined. */ | |
4583 | if (TREE_OVERFLOW_P (r) && !TREE_OVERFLOW_P (op)) | |
4584 | TREE_OVERFLOW (r) = false; | |
4585 | } | |
4586 | break; | |
4587 | ||
4588 | case EMPTY_CLASS_EXPR: | |
4589 | /* This is good enough for a function argument that might not get | |
4590 | used, and they can't do anything with it, so just return it. */ | |
4591 | return t; | |
4592 | ||
60813a46 | 4593 | case STATEMENT_LIST: |
56632b27 JM |
4594 | new_ctx = *ctx; |
4595 | new_ctx.ctor = new_ctx.object = NULL_TREE; | |
2b3ab879 | 4596 | return cxx_eval_statement_list (&new_ctx, t, |
56632b27 | 4597 | non_constant_p, overflow_p, jump_target); |
60813a46 JM |
4598 | |
4599 | case BIND_EXPR: | |
4600 | return cxx_eval_constant_expression (ctx, BIND_EXPR_BODY (t), | |
92a596e8 | 4601 | lval, |
56632b27 JM |
4602 | non_constant_p, overflow_p, |
4603 | jump_target); | |
60813a46 | 4604 | |
2d76680f PC |
4605 | case PREINCREMENT_EXPR: |
4606 | case POSTINCREMENT_EXPR: | |
4607 | case PREDECREMENT_EXPR: | |
4608 | case POSTDECREMENT_EXPR: | |
2b3ab879 | 4609 | return cxx_eval_increment_expression (ctx, t, |
92a596e8 | 4610 | lval, non_constant_p, overflow_p); |
60813a46 JM |
4611 | |
4612 | case LAMBDA_EXPR: | |
2d76680f PC |
4613 | case NEW_EXPR: |
4614 | case VEC_NEW_EXPR: | |
4615 | case DELETE_EXPR: | |
4616 | case VEC_DELETE_EXPR: | |
4617 | case THROW_EXPR: | |
2d76680f PC |
4618 | case MODOP_EXPR: |
4619 | /* GCC internal stuff. */ | |
4620 | case VA_ARG_EXPR: | |
4621 | case OBJ_TYPE_REF: | |
2d76680f PC |
4622 | case NON_DEPENDENT_EXPR: |
4623 | case BASELINK: | |
2d76680f | 4624 | case OFFSET_REF: |
2b3ab879 | 4625 | if (!ctx->quiet) |
2d76680f | 4626 | error_at (EXPR_LOC_OR_LOC (t, input_location), |
64d6d399 | 4627 | "expression %qE is not a constant expression", t); |
2d76680f PC |
4628 | *non_constant_p = true; |
4629 | break; | |
4630 | ||
3e605b20 | 4631 | case PLACEHOLDER_EXPR: |
89262ec6 JM |
4632 | /* Use of the value or address of the current object. */ |
4633 | if (tree ctor = lookup_placeholder (ctx, lval, TREE_TYPE (t))) | |
4634 | return cxx_eval_constant_expression (ctx, ctor, lval, | |
4635 | non_constant_p, overflow_p); | |
4636 | /* A placeholder without a referent. We can get here when | |
4637 | checking whether NSDMIs are noexcept, or in massage_init_elt; | |
4638 | just say it's non-constant for now. */ | |
4639 | gcc_assert (ctx->quiet); | |
4640 | *non_constant_p = true; | |
3e605b20 JM |
4641 | break; |
4642 | ||
06ec22b7 JM |
4643 | case EXIT_EXPR: |
4644 | { | |
4645 | tree cond = TREE_OPERAND (t, 0); | |
4646 | cond = cxx_eval_constant_expression (ctx, cond, /*lval*/false, | |
4647 | non_constant_p, overflow_p); | |
4648 | VERIFY_CONSTANT (cond); | |
4649 | if (integer_nonzerop (cond)) | |
4650 | *jump_target = t; | |
4651 | } | |
4652 | break; | |
4653 | ||
60813a46 | 4654 | case GOTO_EXPR: |
56632b27 | 4655 | *jump_target = TREE_OPERAND (t, 0); |
d49318d9 PC |
4656 | gcc_assert (breaks (jump_target) || continues (jump_target) |
4657 | /* Allow for jumping to a cdtor_label. */ | |
4658 | || returns (jump_target)); | |
56632b27 JM |
4659 | break; |
4660 | ||
60813a46 | 4661 | case LOOP_EXPR: |
2b3ab879 | 4662 | cxx_eval_loop_expr (ctx, t, |
56632b27 JM |
4663 | non_constant_p, overflow_p, jump_target); |
4664 | break; | |
4665 | ||
60813a46 | 4666 | case SWITCH_EXPR: |
2b3ab879 | 4667 | cxx_eval_switch_expr (ctx, t, |
56632b27 | 4668 | non_constant_p, overflow_p, jump_target); |
60813a46 JM |
4669 | break; |
4670 | ||
971e17ff AS |
4671 | case REQUIRES_EXPR: |
4672 | /* It's possible to get a requires-expression in a constant | |
4673 | expression. For example: | |
4674 | ||
4675 | template<typename T> concept bool C() { | |
4676 | return requires (T t) { t; }; | |
4677 | } | |
4678 | ||
4679 | template<typename T> requires !C<T>() void f(T); | |
4680 | ||
4681 | Normalization leaves f with the associated constraint | |
4682 | '!requires (T t) { ... }' which is not transformed into | |
4683 | a constraint. */ | |
4684 | if (!processing_template_decl) | |
4685 | return evaluate_constraint_expression (t, NULL_TREE); | |
4686 | else | |
4687 | *non_constant_p = true; | |
4688 | return t; | |
4689 | ||
98e09245 | 4690 | case ANNOTATE_EXPR: |
98e09245 JJ |
4691 | r = cxx_eval_constant_expression (ctx, TREE_OPERAND (t, 0), |
4692 | lval, | |
4693 | non_constant_p, overflow_p, | |
4694 | jump_target); | |
4695 | break; | |
4696 | ||
2d76680f | 4697 | default: |
c6e7c499 JM |
4698 | if (STATEMENT_CODE_P (TREE_CODE (t))) |
4699 | { | |
4700 | /* This function doesn't know how to deal with pre-genericize | |
4701 | statements; this can only happen with statement-expressions, | |
4702 | so for now just fail. */ | |
4703 | if (!ctx->quiet) | |
4704 | error_at (EXPR_LOCATION (t), | |
64d6d399 | 4705 | "statement is not a constant expression"); |
c6e7c499 JM |
4706 | } |
4707 | else | |
4708 | internal_error ("unexpected expression %qE of kind %s", t, | |
4709 | get_tree_code_name (TREE_CODE (t))); | |
2d76680f PC |
4710 | *non_constant_p = true; |
4711 | break; | |
4712 | } | |
4713 | ||
4714 | if (r == error_mark_node) | |
4715 | *non_constant_p = true; | |
4716 | ||
4717 | if (*non_constant_p) | |
4718 | return t; | |
4719 | else | |
4720 | return r; | |
4721 | } | |
4722 | ||
4723 | static tree | |
3e605b20 | 4724 | cxx_eval_outermost_constant_expr (tree t, bool allow_non_constant, |
69eb4fde | 4725 | bool strict = true, tree object = NULL_TREE) |
2d76680f | 4726 | { |
8108ea30 JM |
4727 | auto_timevar time (TV_CONSTEXPR); |
4728 | ||
2d76680f PC |
4729 | bool non_constant_p = false; |
4730 | bool overflow_p = false; | |
3e605b20 | 4731 | hash_map<tree,tree> map; |
39dce2b7 | 4732 | |
4b390698 | 4733 | constexpr_ctx ctx = { NULL, &map, NULL, NULL, NULL, NULL, |
39dce2b7 JM |
4734 | allow_non_constant, strict }; |
4735 | ||
3e605b20 | 4736 | tree type = initialized_type (t); |
3e605b20 JM |
4737 | tree r = t; |
4738 | if (AGGREGATE_TYPE_P (type) || VECTOR_TYPE_P (type)) | |
4739 | { | |
4740 | /* In C++14 an NSDMI can participate in aggregate initialization, | |
4741 | and can refer to the address of the object being initialized, so | |
4742 | we need to pass in the relevant VAR_DECL if we want to do the | |
4743 | evaluation in a single pass. The evaluation will dynamically | |
4744 | update ctx.values for the VAR_DECL. We use the same strategy | |
4745 | for C++11 constexpr constructors that refer to the object being | |
4746 | initialized. */ | |
4747 | ctx.ctor = build_constructor (type, NULL); | |
4748 | CONSTRUCTOR_NO_IMPLICIT_ZERO (ctx.ctor) = true; | |
60813a46 JM |
4749 | if (!object) |
4750 | { | |
4751 | if (TREE_CODE (t) == TARGET_EXPR) | |
4752 | object = TARGET_EXPR_SLOT (t); | |
4753 | else if (TREE_CODE (t) == AGGR_INIT_EXPR) | |
4754 | object = AGGR_INIT_EXPR_SLOT (t); | |
4755 | } | |
3e605b20 JM |
4756 | ctx.object = object; |
4757 | if (object) | |
4758 | gcc_assert (same_type_ignoring_top_level_qualifiers_p | |
4759 | (type, TREE_TYPE (object))); | |
4760 | if (object && DECL_P (object)) | |
4761 | map.put (object, ctx.ctor); | |
4762 | if (TREE_CODE (r) == TARGET_EXPR) | |
4763 | /* Avoid creating another CONSTRUCTOR when we expand the | |
4764 | TARGET_EXPR. */ | |
4765 | r = TARGET_EXPR_INITIAL (r); | |
4766 | } | |
4767 | ||
2b3ab879 | 4768 | r = cxx_eval_constant_expression (&ctx, r, |
5a804683 | 4769 | false, &non_constant_p, &overflow_p); |
2d76680f PC |
4770 | |
4771 | verify_constant (r, allow_non_constant, &non_constant_p, &overflow_p); | |
4772 | ||
023d89c7 JM |
4773 | /* Mutable logic is a bit tricky: we want to allow initialization of |
4774 | constexpr variables with mutable members, but we can't copy those | |
4775 | members to another constexpr variable. */ | |
4776 | if (TREE_CODE (r) == CONSTRUCTOR | |
4777 | && CONSTRUCTOR_MUTABLE_POISON (r)) | |
2d76680f | 4778 | { |
2d76680f | 4779 | if (!allow_non_constant) |
023d89c7 JM |
4780 | error ("%qE is not a constant expression because it refers to " |
4781 | "mutable subobjects of %qT", t, type); | |
2d76680f PC |
4782 | non_constant_p = true; |
4783 | } | |
4784 | ||
f64e0c02 JM |
4785 | if (TREE_CODE (r) == CONSTRUCTOR |
4786 | && CONSTRUCTOR_NO_IMPLICIT_ZERO (r)) | |
4787 | { | |
4788 | if (!allow_non_constant) | |
4789 | error ("%qE is not a constant expression because it refers to " | |
4790 | "an incompletely initialized variable", t); | |
4791 | TREE_CONSTANT (r) = false; | |
4792 | non_constant_p = true; | |
4793 | } | |
4794 | ||
2d76680f PC |
4795 | /* Technically we should check this for all subexpressions, but that |
4796 | runs into problems with our internal representation of pointer | |
4797 | subtraction and the 5.19 rules are still in flux. */ | |
4798 | if (CONVERT_EXPR_CODE_P (TREE_CODE (r)) | |
4799 | && ARITHMETIC_TYPE_P (TREE_TYPE (r)) | |
4800 | && TREE_CODE (TREE_OPERAND (r, 0)) == ADDR_EXPR) | |
4801 | { | |
4802 | if (!allow_non_constant) | |
4803 | error ("conversion from pointer type %qT " | |
64d6d399 | 4804 | "to arithmetic type %qT in a constant expression", |
2d76680f PC |
4805 | TREE_TYPE (TREE_OPERAND (r, 0)), TREE_TYPE (r)); |
4806 | non_constant_p = true; | |
4807 | } | |
4808 | ||
4809 | if (!non_constant_p && overflow_p) | |
4810 | non_constant_p = true; | |
4811 | ||
56cfb596 PP |
4812 | /* Unshare the result unless it's a CONSTRUCTOR in which case it's already |
4813 | unshared. */ | |
4814 | bool should_unshare = true; | |
4815 | if (r == t || TREE_CODE (r) == CONSTRUCTOR) | |
4816 | should_unshare = false; | |
4817 | ||
2d76680f PC |
4818 | if (non_constant_p && !allow_non_constant) |
4819 | return error_mark_node; | |
4820 | else if (non_constant_p && TREE_CONSTANT (r)) | |
4821 | { | |
4822 | /* This isn't actually constant, so unset TREE_CONSTANT. */ | |
4823 | if (EXPR_P (r)) | |
4824 | r = copy_node (r); | |
4825 | else if (TREE_CODE (r) == CONSTRUCTOR) | |
4826 | r = build1 (VIEW_CONVERT_EXPR, TREE_TYPE (r), r); | |
4827 | else | |
4828 | r = build_nop (TREE_TYPE (r), r); | |
4829 | TREE_CONSTANT (r) = false; | |
4830 | } | |
4831 | else if (non_constant_p || r == t) | |
4832 | return t; | |
4833 | ||
56cfb596 PP |
4834 | if (should_unshare) |
4835 | r = unshare_expr (r); | |
4836 | ||
2d76680f PC |
4837 | if (TREE_CODE (r) == CONSTRUCTOR && CLASS_TYPE_P (TREE_TYPE (r))) |
4838 | { | |
4839 | if (TREE_CODE (t) == TARGET_EXPR | |
4840 | && TARGET_EXPR_INITIAL (t) == r) | |
4841 | return t; | |
4842 | else | |
4843 | { | |
4844 | r = get_target_expr (r); | |
4845 | TREE_CONSTANT (r) = true; | |
4846 | return r; | |
4847 | } | |
4848 | } | |
4849 | else | |
4850 | return r; | |
4851 | } | |
4852 | ||
4853 | /* Returns true if T is a valid subexpression of a constant expression, | |
4854 | even if it isn't itself a constant expression. */ | |
4855 | ||
4856 | bool | |
4857 | is_sub_constant_expr (tree t) | |
4858 | { | |
4859 | bool non_constant_p = false; | |
4860 | bool overflow_p = false; | |
3e605b20 | 4861 | hash_map <tree, tree> map; |
39dce2b7 | 4862 | |
4b390698 | 4863 | constexpr_ctx ctx = { NULL, &map, NULL, NULL, NULL, NULL, true, true }; |
39dce2b7 | 4864 | |
2b3ab879 | 4865 | cxx_eval_constant_expression (&ctx, t, false, &non_constant_p, |
5a804683 | 4866 | &overflow_p); |
2d76680f PC |
4867 | return !non_constant_p && !overflow_p; |
4868 | } | |
4869 | ||
4870 | /* If T represents a constant expression returns its reduced value. | |
4871 | Otherwise return error_mark_node. If T is dependent, then | |
4872 | return NULL. */ | |
4873 | ||
4874 | tree | |
3e605b20 | 4875 | cxx_constant_value (tree t, tree decl) |
2d76680f | 4876 | { |
69eb4fde | 4877 | return cxx_eval_outermost_constant_expr (t, false, true, decl); |
2d76680f PC |
4878 | } |
4879 | ||
cda0a029 JM |
4880 | /* Helper routine for fold_simple function. Either return simplified |
4881 | expression T, otherwise NULL_TREE. | |
4882 | In contrast to cp_fully_fold, and to maybe_constant_value, we try to fold | |
4883 | even if we are within template-declaration. So be careful on call, as in | |
4884 | such case types can be undefined. */ | |
4885 | ||
4886 | static tree | |
4887 | fold_simple_1 (tree t) | |
4888 | { | |
4889 | tree op1; | |
4890 | enum tree_code code = TREE_CODE (t); | |
4891 | ||
4892 | switch (code) | |
4893 | { | |
4894 | case INTEGER_CST: | |
4895 | case REAL_CST: | |
4896 | case VECTOR_CST: | |
4897 | case FIXED_CST: | |
4898 | case COMPLEX_CST: | |
4899 | return t; | |
4900 | ||
4901 | case SIZEOF_EXPR: | |
4902 | return fold_sizeof_expr (t); | |
4903 | ||
4904 | case ABS_EXPR: | |
4905 | case CONJ_EXPR: | |
4906 | case REALPART_EXPR: | |
4907 | case IMAGPART_EXPR: | |
4908 | case NEGATE_EXPR: | |
4909 | case BIT_NOT_EXPR: | |
4910 | case TRUTH_NOT_EXPR: | |
4911 | case NOP_EXPR: | |
4912 | case VIEW_CONVERT_EXPR: | |
4913 | case CONVERT_EXPR: | |
4914 | case FLOAT_EXPR: | |
4915 | case FIX_TRUNC_EXPR: | |
4916 | case FIXED_CONVERT_EXPR: | |
4917 | case ADDR_SPACE_CONVERT_EXPR: | |
4918 | ||
4919 | op1 = TREE_OPERAND (t, 0); | |
4920 | ||
4921 | t = const_unop (code, TREE_TYPE (t), op1); | |
4922 | if (!t) | |
4923 | return NULL_TREE; | |
4924 | ||
4925 | if (CONVERT_EXPR_CODE_P (code) | |
4926 | && TREE_OVERFLOW_P (t) && !TREE_OVERFLOW_P (op1)) | |
4927 | TREE_OVERFLOW (t) = false; | |
4928 | return t; | |
4929 | ||
4930 | default: | |
4931 | return NULL_TREE; | |
4932 | } | |
4933 | } | |
4934 | ||
4935 | /* If T is a simple constant expression, returns its simplified value. | |
4936 | Otherwise returns T. In contrast to maybe_constant_value do we | |
4937 | simplify only few operations on constant-expressions, and we don't | |
4938 | try to simplify constexpressions. */ | |
4939 | ||
4940 | tree | |
4941 | fold_simple (tree t) | |
4942 | { | |
4943 | tree r = NULL_TREE; | |
4944 | if (processing_template_decl) | |
4945 | return t; | |
4946 | ||
4947 | r = fold_simple_1 (t); | |
4948 | if (!r) | |
4949 | r = t; | |
4950 | ||
4951 | return r; | |
4952 | } | |
4953 | ||
2d76680f PC |
4954 | /* If T is a constant expression, returns its reduced value. |
4955 | Otherwise, if T does not have TREE_CONSTANT set, returns T. | |
4956 | Otherwise, returns a version of T without TREE_CONSTANT. */ | |
4957 | ||
8a87daca JM |
4958 | static GTY((deletable)) hash_map<tree, tree> *cv_cache; |
4959 | ||
4960 | tree | |
4961 | maybe_constant_value (tree t, tree decl) | |
2d76680f PC |
4962 | { |
4963 | tree r; | |
4964 | ||
a0ab7ccd | 4965 | if (!is_nondependent_constant_expression (t)) |
2d76680f PC |
4966 | { |
4967 | if (TREE_OVERFLOW_P (t)) | |
4968 | { | |
4969 | t = build_nop (TREE_TYPE (t), t); | |
4970 | TREE_CONSTANT (t) = false; | |
4971 | } | |
4972 | return t; | |
4973 | } | |
8a87daca JM |
4974 | else if (CONSTANT_CLASS_P (t)) |
4975 | /* No caching or evaluation needed. */ | |
4976 | return t; | |
4977 | ||
4978 | if (cv_cache == NULL) | |
4979 | cv_cache = hash_map<tree, tree>::create_ggc (101); | |
4980 | if (tree *cached = cv_cache->get (t)) | |
4981 | return *cached; | |
2d76680f | 4982 | |
69eb4fde | 4983 | r = cxx_eval_outermost_constant_expr (t, true, true, decl); |
595278be MM |
4984 | gcc_checking_assert (r == t |
4985 | || CONVERT_EXPR_P (t) | |
4986 | || TREE_CODE (t) == VIEW_CONVERT_EXPR | |
4987 | || (TREE_CONSTANT (t) && !TREE_CONSTANT (r)) | |
4988 | || !cp_tree_equal (r, t)); | |
8a87daca | 4989 | cv_cache->put (t, r); |
2d76680f PC |
4990 | return r; |
4991 | } | |
4992 | ||
7a7ac32a PP |
4993 | /* Dispose of the whole CV_CACHE. */ |
4994 | ||
4995 | static void | |
4996 | clear_cv_cache (void) | |
4997 | { | |
4998 | if (cv_cache != NULL) | |
4999 | cv_cache->empty (); | |
5000 | } | |
5001 | ||
eba9e839 | 5002 | /* Dispose of the whole CV_CACHE and FOLD_CACHE. */ |
1e297006 MP |
5003 | |
5004 | void | |
eba9e839 | 5005 | clear_cv_and_fold_caches (void) |
1e297006 | 5006 | { |
7a7ac32a | 5007 | clear_cv_cache (); |
eba9e839 | 5008 | clear_fold_cache (); |
1e297006 MP |
5009 | } |
5010 | ||
234bef96 PC |
5011 | /* Like maybe_constant_value but first fully instantiate the argument. |
5012 | ||
5013 | Note: this is equivalent to instantiate_non_dependent_expr_sfinae | |
5014 | (t, tf_none) followed by maybe_constant_value but is more efficient, | |
5015 | because calls instantiation_dependent_expression_p and | |
5016 | potential_constant_expression at most once. */ | |
5017 | ||
5018 | tree | |
5019 | fold_non_dependent_expr (tree t) | |
5020 | { | |
5021 | if (t == NULL_TREE) | |
5022 | return NULL_TREE; | |
5023 | ||
5024 | /* If we're in a template, but T isn't value dependent, simplify | |
5025 | it. We're supposed to treat: | |
5026 | ||
5027 | template <typename T> void f(T[1 + 1]); | |
5028 | template <typename T> void f(T[2]); | |
5029 | ||
5030 | as two declarations of the same function, for example. */ | |
5031 | if (processing_template_decl) | |
5032 | { | |
a0ab7ccd | 5033 | if (is_nondependent_constant_expression (t)) |
234bef96 | 5034 | { |
1b5695e6 JM |
5035 | processing_template_decl_sentinel s; |
5036 | t = instantiate_non_dependent_expr_internal (t, tf_none); | |
234bef96 PC |
5037 | |
5038 | if (type_unknown_p (t) | |
5039 | || BRACE_ENCLOSED_INITIALIZER_P (t)) | |
5040 | { | |
5041 | if (TREE_OVERFLOW_P (t)) | |
5042 | { | |
5043 | t = build_nop (TREE_TYPE (t), t); | |
5044 | TREE_CONSTANT (t) = false; | |
5045 | } | |
5046 | return t; | |
5047 | } | |
5048 | ||
69eb4fde | 5049 | tree r = cxx_eval_outermost_constant_expr (t, true, true, NULL_TREE); |
234bef96 | 5050 | /* cp_tree_equal looks through NOPs, so allow them. */ |
595278be MM |
5051 | gcc_checking_assert (r == t |
5052 | || CONVERT_EXPR_P (t) | |
5053 | || TREE_CODE (t) == VIEW_CONVERT_EXPR | |
5054 | || (TREE_CONSTANT (t) && !TREE_CONSTANT (r)) | |
5055 | || !cp_tree_equal (r, t)); | |
234bef96 PC |
5056 | return r; |
5057 | } | |
5058 | else if (TREE_OVERFLOW_P (t)) | |
5059 | { | |
5060 | t = build_nop (TREE_TYPE (t), t); | |
5061 | TREE_CONSTANT (t) = false; | |
5062 | } | |
5063 | return t; | |
5064 | } | |
5065 | ||
5066 | return maybe_constant_value (t); | |
5067 | } | |
5068 | ||
2d76680f PC |
5069 | /* Like maybe_constant_value, but returns a CONSTRUCTOR directly, rather |
5070 | than wrapped in a TARGET_EXPR. */ | |
5071 | ||
5072 | tree | |
3e605b20 | 5073 | maybe_constant_init (tree t, tree decl) |
2d76680f | 5074 | { |
cda0a029 JM |
5075 | if (!t) |
5076 | return t; | |
2d76680f PC |
5077 | if (TREE_CODE (t) == EXPR_STMT) |
5078 | t = TREE_OPERAND (t, 0); | |
5079 | if (TREE_CODE (t) == CONVERT_EXPR | |
5080 | && VOID_TYPE_P (TREE_TYPE (t))) | |
5081 | t = TREE_OPERAND (t, 0); | |
60813a46 JM |
5082 | if (TREE_CODE (t) == INIT_EXPR) |
5083 | t = TREE_OPERAND (t, 1); | |
f64e0c02 JM |
5084 | if (TREE_CODE (t) == TARGET_EXPR) |
5085 | t = TARGET_EXPR_INITIAL (t); | |
a0ab7ccd | 5086 | if (!is_nondependent_static_init_expression (t)) |
69eb4fde | 5087 | /* Don't try to evaluate it. */; |
8a87daca JM |
5088 | else if (CONSTANT_CLASS_P (t)) |
5089 | /* No evaluation needed. */; | |
69eb4fde JM |
5090 | else |
5091 | t = cxx_eval_outermost_constant_expr (t, true, false, decl); | |
2d76680f PC |
5092 | if (TREE_CODE (t) == TARGET_EXPR) |
5093 | { | |
5094 | tree init = TARGET_EXPR_INITIAL (t); | |
5095 | if (TREE_CODE (init) == CONSTRUCTOR) | |
5096 | t = init; | |
5097 | } | |
5098 | return t; | |
5099 | } | |
5100 | ||
5101 | #if 0 | |
5102 | /* FIXME see ADDR_EXPR section in potential_constant_expression_1. */ | |
5103 | /* Return true if the object referred to by REF has automatic or thread | |
5104 | local storage. */ | |
5105 | ||
5106 | enum { ck_ok, ck_bad, ck_unknown }; | |
5107 | static int | |
5108 | check_automatic_or_tls (tree ref) | |
5109 | { | |
ef4bddc2 | 5110 | machine_mode mode; |
f37fac2b | 5111 | poly_int64 bitsize, bitpos; |
2d76680f PC |
5112 | tree offset; |
5113 | int volatilep = 0, unsignedp = 0; | |
5114 | tree decl = get_inner_reference (ref, &bitsize, &bitpos, &offset, | |
5115 | &mode, &unsignedp, &volatilep, false); | |
5116 | duration_kind dk; | |
5117 | ||
5118 | /* If there isn't a decl in the middle, we don't know the linkage here, | |
5119 | and this isn't a constant expression anyway. */ | |
5120 | if (!DECL_P (decl)) | |
5121 | return ck_unknown; | |
5122 | dk = decl_storage_duration (decl); | |
5123 | return (dk == dk_auto || dk == dk_thread) ? ck_bad : ck_ok; | |
5124 | } | |
5125 | #endif | |
5126 | ||
5127 | /* Return true if T denotes a potentially constant expression. Issue | |
5128 | diagnostic as appropriate under control of FLAGS. If WANT_RVAL is true, | |
a0ab7ccd JM |
5129 | an lvalue-rvalue conversion is implied. If NOW is true, we want to |
5130 | consider the expression in the current context, independent of constexpr | |
5131 | substitution. | |
2d76680f PC |
5132 | |
5133 | C++0x [expr.const] used to say | |
5134 | ||
5135 | 6 An expression is a potential constant expression if it is | |
5136 | a constant expression where all occurrences of function | |
5137 | parameters are replaced by arbitrary constant expressions | |
5138 | of the appropriate type. | |
5139 | ||
5140 | 2 A conditional expression is a constant expression unless it | |
5141 | involves one of the following as a potentially evaluated | |
5142 | subexpression (3.2), but subexpressions of logical AND (5.14), | |
5143 | logical OR (5.15), and conditional (5.16) operations that are | |
5144 | not evaluated are not considered. */ | |
5145 | ||
5146 | static bool | |
a0ab7ccd | 5147 | potential_constant_expression_1 (tree t, bool want_rval, bool strict, bool now, |
69eb4fde | 5148 | tsubst_flags_t flags) |
2d76680f | 5149 | { |
a0ab7ccd JM |
5150 | #define RECUR(T,RV) \ |
5151 | potential_constant_expression_1 ((T), (RV), strict, now, flags) | |
5152 | ||
2d76680f PC |
5153 | enum { any = false, rval = true }; |
5154 | int i; | |
5155 | tree tmp; | |
5156 | ||
5157 | if (t == error_mark_node) | |
5158 | return false; | |
5159 | if (t == NULL_TREE) | |
5160 | return true; | |
e40b6fc7 | 5161 | location_t loc = EXPR_LOC_OR_LOC (t, input_location); |
19dedccf | 5162 | if (TREE_THIS_VOLATILE (t) && !DECL_P (t)) |
2d76680f PC |
5163 | { |
5164 | if (flags & tf_error) | |
e40b6fc7 | 5165 | error_at (loc, "expression %qE has side-effects", t); |
2d76680f PC |
5166 | return false; |
5167 | } | |
5168 | if (CONSTANT_CLASS_P (t)) | |
5169 | return true; | |
7dc2b4a2 JM |
5170 | if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_TYPED) |
5171 | && TREE_TYPE (t) == error_mark_node) | |
5172 | return false; | |
2d76680f PC |
5173 | |
5174 | switch (TREE_CODE (t)) | |
5175 | { | |
5176 | case FUNCTION_DECL: | |
5177 | case BASELINK: | |
5178 | case TEMPLATE_DECL: | |
5179 | case OVERLOAD: | |
5180 | case TEMPLATE_ID_EXPR: | |
5181 | case LABEL_DECL: | |
5182 | case LABEL_EXPR: | |
60813a46 | 5183 | case CASE_LABEL_EXPR: |
2d76680f PC |
5184 | case CONST_DECL: |
5185 | case SIZEOF_EXPR: | |
5186 | case ALIGNOF_EXPR: | |
5187 | case OFFSETOF_EXPR: | |
5188 | case NOEXCEPT_EXPR: | |
5189 | case TEMPLATE_PARM_INDEX: | |
5190 | case TRAIT_EXPR: | |
5191 | case IDENTIFIER_NODE: | |
5192 | case USERDEF_LITERAL: | |
5193 | /* We can see a FIELD_DECL in a pointer-to-member expression. */ | |
5194 | case FIELD_DECL: | |
cda0a029 | 5195 | case RESULT_DECL: |
2d76680f | 5196 | case USING_DECL: |
60813a46 | 5197 | case USING_STMT: |
3e605b20 | 5198 | case PLACEHOLDER_EXPR: |
60813a46 JM |
5199 | case BREAK_STMT: |
5200 | case CONTINUE_STMT: | |
971e17ff | 5201 | case REQUIRES_EXPR: |
98e5a19a | 5202 | case STATIC_ASSERT: |
96a95ac1 | 5203 | case DEBUG_BEGIN_STMT: |
2d76680f PC |
5204 | return true; |
5205 | ||
a0ab7ccd JM |
5206 | case PARM_DECL: |
5207 | if (now) | |
5208 | { | |
5209 | if (flags & tf_error) | |
5210 | error ("%qE is not a constant expression", t); | |
5211 | return false; | |
5212 | } | |
5213 | return true; | |
5214 | ||
2d76680f PC |
5215 | case AGGR_INIT_EXPR: |
5216 | case CALL_EXPR: | |
5217 | /* -- an invocation of a function other than a constexpr function | |
5218 | or a constexpr constructor. */ | |
5219 | { | |
5220 | tree fun = get_function_named_in_call (t); | |
5221 | const int nargs = call_expr_nargs (t); | |
5222 | i = 0; | |
5223 | ||
60813a46 JM |
5224 | if (fun == NULL_TREE) |
5225 | { | |
44a845ca MS |
5226 | /* Reset to allow the function to continue past the end |
5227 | of the block below. Otherwise return early. */ | |
5228 | bool bail = true; | |
5229 | ||
35228ac7 JJ |
5230 | if (TREE_CODE (t) == CALL_EXPR |
5231 | && CALL_EXPR_FN (t) == NULL_TREE) | |
5232 | switch (CALL_EXPR_IFN (t)) | |
5233 | { | |
5234 | /* These should be ignored, they are optimized away from | |
5235 | constexpr functions. */ | |
5236 | case IFN_UBSAN_NULL: | |
5237 | case IFN_UBSAN_BOUNDS: | |
5238 | case IFN_UBSAN_VPTR: | |
81fea426 | 5239 | case IFN_FALLTHROUGH: |
35228ac7 | 5240 | return true; |
44a845ca MS |
5241 | |
5242 | case IFN_ADD_OVERFLOW: | |
5243 | case IFN_SUB_OVERFLOW: | |
5244 | case IFN_MUL_OVERFLOW: | |
e16f1cc7 | 5245 | case IFN_LAUNDER: |
44a845ca MS |
5246 | bail = false; |
5247 | ||
35228ac7 JJ |
5248 | default: |
5249 | break; | |
5250 | } | |
44a845ca MS |
5251 | |
5252 | if (bail) | |
5253 | { | |
5254 | /* fold_call_expr can't do anything with IFN calls. */ | |
5255 | if (flags & tf_error) | |
e40b6fc7 | 5256 | error_at (loc, "call to internal function %qE", t); |
44a845ca MS |
5257 | return false; |
5258 | } | |
60813a46 | 5259 | } |
44a845ca MS |
5260 | |
5261 | if (fun && is_overloaded_fn (fun)) | |
2d76680f PC |
5262 | { |
5263 | if (TREE_CODE (fun) == FUNCTION_DECL) | |
5264 | { | |
5265 | if (builtin_valid_in_constant_expr_p (fun)) | |
5266 | return true; | |
5267 | if (!DECL_DECLARED_CONSTEXPR_P (fun) | |
5268 | /* Allow any built-in function; if the expansion | |
5269 | isn't constant, we'll deal with that then. */ | |
5270 | && !is_builtin_fn (fun)) | |
5271 | { | |
5272 | if (flags & tf_error) | |
5273 | { | |
84fa214d | 5274 | error_at (loc, "call to non-%<constexpr%> function %qD", |
e40b6fc7 | 5275 | fun); |
2d76680f PC |
5276 | explain_invalid_constexpr_fn (fun); |
5277 | } | |
5278 | return false; | |
5279 | } | |
5280 | /* A call to a non-static member function takes the address | |
5281 | of the object as the first argument. But in a constant | |
5282 | expression the address will be folded away, so look | |
5283 | through it now. */ | |
5284 | if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fun) | |
5285 | && !DECL_CONSTRUCTOR_P (fun)) | |
5286 | { | |
5287 | tree x = get_nth_callarg (t, 0); | |
5288 | if (is_this_parameter (x)) | |
3e605b20 | 5289 | return true; |
a0ab7ccd JM |
5290 | /* Don't require an immediately constant value, as |
5291 | constexpr substitution might not use the value. */ | |
5292 | bool sub_now = false; | |
5293 | if (!potential_constant_expression_1 (x, rval, strict, | |
5294 | sub_now, flags)) | |
2d76680f PC |
5295 | return false; |
5296 | i = 1; | |
5297 | } | |
5298 | } | |
5299 | else | |
5300 | { | |
69eb4fde | 5301 | if (!RECUR (fun, true)) |
2d76680f PC |
5302 | return false; |
5303 | fun = get_first_fn (fun); | |
5304 | } | |
5305 | /* Skip initial arguments to base constructors. */ | |
5306 | if (DECL_BASE_CONSTRUCTOR_P (fun)) | |
5307 | i = num_artificial_parms_for (fun); | |
5308 | fun = DECL_ORIGIN (fun); | |
5309 | } | |
44a845ca | 5310 | else if (fun) |
2d76680f | 5311 | { |
69eb4fde | 5312 | if (RECUR (fun, rval)) |
2d76680f PC |
5313 | /* Might end up being a constant function pointer. */; |
5314 | else | |
5315 | return false; | |
5316 | } | |
5317 | for (; i < nargs; ++i) | |
5318 | { | |
5319 | tree x = get_nth_callarg (t, i); | |
c3c29ba5 JM |
5320 | /* In a template, reference arguments haven't been converted to |
5321 | REFERENCE_TYPE and we might not even know if the parameter | |
5322 | is a reference, so accept lvalue constants too. */ | |
5323 | bool rv = processing_template_decl ? any : rval; | |
a0ab7ccd JM |
5324 | /* Don't require an immediately constant value, as constexpr |
5325 | substitution might not use the value of the argument. */ | |
5326 | bool sub_now = false; | |
5327 | if (!potential_constant_expression_1 (x, rv, strict, | |
5328 | sub_now, flags)) | |
2d76680f PC |
5329 | return false; |
5330 | } | |
5331 | return true; | |
5332 | } | |
5333 | ||
5334 | case NON_LVALUE_EXPR: | |
5335 | /* -- an lvalue-to-rvalue conversion (4.1) unless it is applied to | |
5336 | -- an lvalue of integral type that refers to a non-volatile | |
5337 | const variable or static data member initialized with | |
5338 | constant expressions, or | |
5339 | ||
5340 | -- an lvalue of literal type that refers to non-volatile | |
5341 | object defined with constexpr, or that refers to a | |
5342 | sub-object of such an object; */ | |
69eb4fde | 5343 | return RECUR (TREE_OPERAND (t, 0), rval); |
2d76680f PC |
5344 | |
5345 | case VAR_DECL: | |
70f40fea | 5346 | if (DECL_HAS_VALUE_EXPR_P (t)) |
c1051bf7 JM |
5347 | { |
5348 | if (now && is_normal_capture_proxy (t)) | |
5349 | { | |
5350 | /* -- in a lambda-expression, a reference to this or to a | |
5351 | variable with automatic storage duration defined outside that | |
5352 | lambda-expression, where the reference would be an | |
5353 | odr-use. */ | |
5354 | if (flags & tf_error) | |
5355 | { | |
5356 | tree cap = DECL_CAPTURED_VARIABLE (t); | |
5357 | error ("lambda capture of %qE is not a constant expression", | |
5358 | cap); | |
5359 | if (!want_rval && decl_constant_var_p (cap)) | |
5360 | inform (input_location, "because it is used as a glvalue"); | |
5361 | } | |
5362 | return false; | |
5363 | } | |
5364 | return RECUR (DECL_VALUE_EXPR (t), rval); | |
5365 | } | |
69eb4fde | 5366 | if (want_rval |
98e5a19a | 5367 | && !var_in_maybe_constexpr_fn (t) |
7dc2b4a2 | 5368 | && !type_dependent_expression_p (t) |
4b691b13 | 5369 | && !decl_maybe_constant_var_p (t) |
69eb4fde JM |
5370 | && (strict |
5371 | || !CP_TYPE_CONST_NON_VOLATILE_P (TREE_TYPE (t)) | |
4b691b13 JM |
5372 | || (DECL_INITIAL (t) |
5373 | && !DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (t))) | |
7dc2b4a2 JM |
5374 | && COMPLETE_TYPE_P (TREE_TYPE (t)) |
5375 | && !is_really_empty_class (TREE_TYPE (t))) | |
2d76680f PC |
5376 | { |
5377 | if (flags & tf_error) | |
5378 | non_const_var_error (t); | |
5379 | return false; | |
5380 | } | |
5381 | return true; | |
5382 | ||
5383 | case NOP_EXPR: | |
5384 | case CONVERT_EXPR: | |
5385 | case VIEW_CONVERT_EXPR: | |
5386 | /* -- a reinterpret_cast. FIXME not implemented, and this rule | |
5387 | may change to something more specific to type-punning (DR 1312). */ | |
5388 | { | |
5389 | tree from = TREE_OPERAND (t, 0); | |
5390 | if (POINTER_TYPE_P (TREE_TYPE (t)) | |
5391 | && TREE_CODE (from) == INTEGER_CST | |
5392 | && !integer_zerop (from)) | |
5393 | { | |
5394 | if (flags & tf_error) | |
e40b6fc7 | 5395 | error_at (loc, "reinterpret_cast from integer to pointer"); |
2d76680f PC |
5396 | return false; |
5397 | } | |
69eb4fde | 5398 | return (RECUR (from, TREE_CODE (t) != VIEW_CONVERT_EXPR)); |
2d76680f PC |
5399 | } |
5400 | ||
be845b04 JJ |
5401 | case ADDRESSOF_EXPR: |
5402 | /* This is like ADDR_EXPR, except it won't form pointer-to-member. */ | |
5403 | t = TREE_OPERAND (t, 0); | |
5404 | goto handle_addr_expr; | |
5405 | ||
2d76680f PC |
5406 | case ADDR_EXPR: |
5407 | /* -- a unary operator & that is applied to an lvalue that | |
5408 | designates an object with thread or automatic storage | |
5409 | duration; */ | |
5410 | t = TREE_OPERAND (t, 0); | |
5411 | ||
5412 | if (TREE_CODE (t) == OFFSET_REF && PTRMEM_OK_P (t)) | |
5413 | /* A pointer-to-member constant. */ | |
5414 | return true; | |
5415 | ||
be845b04 | 5416 | handle_addr_expr: |
2d76680f PC |
5417 | #if 0 |
5418 | /* FIXME adjust when issue 1197 is fully resolved. For now don't do | |
5419 | any checking here, as we might dereference the pointer later. If | |
5420 | we remove this code, also remove check_automatic_or_tls. */ | |
5421 | i = check_automatic_or_tls (t); | |
5422 | if (i == ck_ok) | |
5423 | return true; | |
5424 | if (i == ck_bad) | |
5425 | { | |
5426 | if (flags & tf_error) | |
5427 | error ("address-of an object %qE with thread local or " | |
5428 | "automatic storage is not a constant expression", t); | |
5429 | return false; | |
5430 | } | |
5431 | #endif | |
69eb4fde | 5432 | return RECUR (t, any); |
2d76680f | 5433 | |
dc8d2d00 JM |
5434 | case REALPART_EXPR: |
5435 | case IMAGPART_EXPR: | |
2d76680f PC |
5436 | case COMPONENT_REF: |
5437 | case BIT_FIELD_REF: | |
5438 | case ARROW_EXPR: | |
5439 | case OFFSET_REF: | |
5440 | /* -- a class member access unless its postfix-expression is | |
5441 | of literal type or of pointer to literal type. */ | |
5442 | /* This test would be redundant, as it follows from the | |
5443 | postfix-expression being a potential constant expression. */ | |
19dedccf JM |
5444 | if (type_unknown_p (t)) |
5445 | return true; | |
69eb4fde | 5446 | return RECUR (TREE_OPERAND (t, 0), want_rval); |
2d76680f PC |
5447 | |
5448 | case EXPR_PACK_EXPANSION: | |
69eb4fde | 5449 | return RECUR (PACK_EXPANSION_PATTERN (t), want_rval); |
2d76680f PC |
5450 | |
5451 | case INDIRECT_REF: | |
5452 | { | |
5453 | tree x = TREE_OPERAND (t, 0); | |
5454 | STRIP_NOPS (x); | |
948d0d91 | 5455 | if (is_this_parameter (x) && !is_capture_proxy (x)) |
2d76680f | 5456 | { |
5d4e573b | 5457 | if (!var_in_maybe_constexpr_fn (x)) |
2d76680f PC |
5458 | { |
5459 | if (flags & tf_error) | |
e40b6fc7 | 5460 | error_at (loc, "use of %<this%> in a constant expression"); |
2d76680f PC |
5461 | return false; |
5462 | } | |
2d76680f PC |
5463 | return true; |
5464 | } | |
69eb4fde | 5465 | return RECUR (x, rval); |
2d76680f PC |
5466 | } |
5467 | ||
60813a46 JM |
5468 | case STATEMENT_LIST: |
5469 | { | |
5470 | tree_stmt_iterator i; | |
5471 | for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i)) | |
5472 | { | |
69eb4fde | 5473 | if (!RECUR (tsi_stmt (i), any)) |
60813a46 JM |
5474 | return false; |
5475 | } | |
5476 | return true; | |
5477 | } | |
5478 | break; | |
5479 | ||
5480 | case MODIFY_EXPR: | |
5481 | if (cxx_dialect < cxx14) | |
5482 | goto fail; | |
69eb4fde | 5483 | if (!RECUR (TREE_OPERAND (t, 0), any)) |
60813a46 | 5484 | return false; |
69eb4fde | 5485 | if (!RECUR (TREE_OPERAND (t, 1), rval)) |
60813a46 JM |
5486 | return false; |
5487 | return true; | |
5488 | ||
5489 | case MODOP_EXPR: | |
5490 | if (cxx_dialect < cxx14) | |
5491 | goto fail; | |
69eb4fde | 5492 | if (!RECUR (TREE_OPERAND (t, 0), rval)) |
60813a46 | 5493 | return false; |
69eb4fde | 5494 | if (!RECUR (TREE_OPERAND (t, 2), rval)) |
60813a46 JM |
5495 | return false; |
5496 | return true; | |
5497 | ||
60813a46 | 5498 | case DO_STMT: |
69eb4fde | 5499 | if (!RECUR (DO_COND (t), rval)) |
60813a46 | 5500 | return false; |
69eb4fde | 5501 | if (!RECUR (DO_BODY (t), any)) |
60813a46 JM |
5502 | return false; |
5503 | return true; | |
5504 | ||
5505 | case FOR_STMT: | |
69eb4fde | 5506 | if (!RECUR (FOR_INIT_STMT (t), any)) |
60813a46 | 5507 | return false; |
69eb4fde | 5508 | if (!RECUR (FOR_COND (t), rval)) |
60813a46 | 5509 | return false; |
69eb4fde | 5510 | if (!RECUR (FOR_EXPR (t), any)) |
60813a46 | 5511 | return false; |
69eb4fde | 5512 | if (!RECUR (FOR_BODY (t), any)) |
60813a46 JM |
5513 | return false; |
5514 | return true; | |
5515 | ||
98e5a19a JM |
5516 | case RANGE_FOR_STMT: |
5517 | if (!RECUR (RANGE_FOR_EXPR (t), any)) | |
5518 | return false; | |
5519 | if (!RECUR (RANGE_FOR_BODY (t), any)) | |
5520 | return false; | |
5521 | return true; | |
5522 | ||
60813a46 | 5523 | case WHILE_STMT: |
69eb4fde | 5524 | if (!RECUR (WHILE_COND (t), rval)) |
60813a46 | 5525 | return false; |
69eb4fde | 5526 | if (!RECUR (WHILE_BODY (t), any)) |
60813a46 JM |
5527 | return false; |
5528 | return true; | |
5529 | ||
5530 | case SWITCH_STMT: | |
69eb4fde | 5531 | if (!RECUR (SWITCH_STMT_COND (t), rval)) |
60813a46 | 5532 | return false; |
ce965730 MT |
5533 | /* FIXME we don't check SWITCH_STMT_BODY currently, because even |
5534 | unreachable labels would be checked. */ | |
60813a46 JM |
5535 | return true; |
5536 | ||
58611fb6 | 5537 | case STMT_EXPR: |
69eb4fde | 5538 | return RECUR (STMT_EXPR_STMT (t), rval); |
58611fb6 | 5539 | |
2d76680f | 5540 | case LAMBDA_EXPR: |
899ac3b8 JM |
5541 | if (cxx_dialect >= cxx17) |
5542 | /* In C++17 lambdas can be constexpr, don't give up yet. */ | |
5543 | return true; | |
5544 | else if (flags & tf_error) | |
5545 | error_at (loc, "lambda-expression is not a constant expression " | |
5546 | "before C++17"); | |
5547 | return false; | |
5548 | ||
2d76680f PC |
5549 | case DYNAMIC_CAST_EXPR: |
5550 | case PSEUDO_DTOR_EXPR: | |
2d76680f PC |
5551 | case NEW_EXPR: |
5552 | case VEC_NEW_EXPR: | |
5553 | case DELETE_EXPR: | |
5554 | case VEC_DELETE_EXPR: | |
5555 | case THROW_EXPR: | |
e40b6fc7 JJ |
5556 | case OMP_PARALLEL: |
5557 | case OMP_TASK: | |
5558 | case OMP_FOR: | |
5559 | case OMP_DISTRIBUTE: | |
5560 | case OMP_TASKLOOP: | |
5561 | case OMP_TEAMS: | |
5562 | case OMP_TARGET_DATA: | |
5563 | case OMP_TARGET: | |
5564 | case OMP_SECTIONS: | |
5565 | case OMP_ORDERED: | |
5566 | case OMP_CRITICAL: | |
5567 | case OMP_SINGLE: | |
5568 | case OMP_SECTION: | |
5569 | case OMP_MASTER: | |
5570 | case OMP_TASKGROUP: | |
5571 | case OMP_TARGET_UPDATE: | |
5572 | case OMP_TARGET_ENTER_DATA: | |
5573 | case OMP_TARGET_EXIT_DATA: | |
2d76680f PC |
5574 | case OMP_ATOMIC: |
5575 | case OMP_ATOMIC_READ: | |
5576 | case OMP_ATOMIC_CAPTURE_OLD: | |
5577 | case OMP_ATOMIC_CAPTURE_NEW: | |
e40b6fc7 JJ |
5578 | case OACC_PARALLEL: |
5579 | case OACC_KERNELS: | |
5580 | case OACC_DATA: | |
5581 | case OACC_HOST_DATA: | |
5582 | case OACC_LOOP: | |
5583 | case OACC_CACHE: | |
5584 | case OACC_DECLARE: | |
5585 | case OACC_ENTER_DATA: | |
5586 | case OACC_EXIT_DATA: | |
5587 | case OACC_UPDATE: | |
2d76680f PC |
5588 | /* GCC internal stuff. */ |
5589 | case VA_ARG_EXPR: | |
5590 | case OBJ_TYPE_REF: | |
2d76680f | 5591 | case TRANSACTION_EXPR: |
60813a46 | 5592 | case ASM_EXPR: |
81b6a6c5 | 5593 | case AT_ENCODE_EXPR: |
60813a46 | 5594 | fail: |
2d76680f | 5595 | if (flags & tf_error) |
e40b6fc7 | 5596 | error_at (loc, "expression %qE is not a constant expression", t); |
2d76680f PC |
5597 | return false; |
5598 | ||
5599 | case TYPEID_EXPR: | |
5600 | /* -- a typeid expression whose operand is of polymorphic | |
5601 | class type; */ | |
5602 | { | |
5603 | tree e = TREE_OPERAND (t, 0); | |
5604 | if (!TYPE_P (e) && !type_dependent_expression_p (e) | |
5605 | && TYPE_POLYMORPHIC_P (TREE_TYPE (e))) | |
5606 | { | |
5607 | if (flags & tf_error) | |
e40b6fc7 JJ |
5608 | error_at (loc, "typeid-expression is not a constant expression " |
5609 | "because %qE is of polymorphic type", e); | |
2d76680f PC |
5610 | return false; |
5611 | } | |
5612 | return true; | |
5613 | } | |
5614 | ||
1af4ebf5 | 5615 | case POINTER_DIFF_EXPR: |
2d76680f | 5616 | case MINUS_EXPR: |
2d76680f PC |
5617 | want_rval = true; |
5618 | goto binary; | |
5619 | ||
5620 | case LT_EXPR: | |
5621 | case LE_EXPR: | |
5622 | case GT_EXPR: | |
5623 | case GE_EXPR: | |
5624 | case EQ_EXPR: | |
5625 | case NE_EXPR: | |
2d76680f PC |
5626 | want_rval = true; |
5627 | goto binary; | |
5628 | ||
60813a46 JM |
5629 | case PREINCREMENT_EXPR: |
5630 | case POSTINCREMENT_EXPR: | |
5631 | case PREDECREMENT_EXPR: | |
5632 | case POSTDECREMENT_EXPR: | |
5633 | if (cxx_dialect < cxx14) | |
5634 | goto fail; | |
5635 | goto unary; | |
5636 | ||
2d76680f PC |
5637 | case BIT_NOT_EXPR: |
5638 | /* A destructor. */ | |
5639 | if (TYPE_P (TREE_OPERAND (t, 0))) | |
5640 | return true; | |
191816a3 | 5641 | /* fall through. */ |
2d76680f | 5642 | |
2d76680f PC |
5643 | case CONJ_EXPR: |
5644 | case SAVE_EXPR: | |
5645 | case FIX_TRUNC_EXPR: | |
5646 | case FLOAT_EXPR: | |
5647 | case NEGATE_EXPR: | |
5648 | case ABS_EXPR: | |
5649 | case TRUTH_NOT_EXPR: | |
5650 | case FIXED_CONVERT_EXPR: | |
5651 | case UNARY_PLUS_EXPR: | |
4856a1f0 PC |
5652 | case UNARY_LEFT_FOLD_EXPR: |
5653 | case UNARY_RIGHT_FOLD_EXPR: | |
60813a46 | 5654 | unary: |
69eb4fde | 5655 | return RECUR (TREE_OPERAND (t, 0), rval); |
2d76680f PC |
5656 | |
5657 | case CAST_EXPR: | |
5658 | case CONST_CAST_EXPR: | |
5659 | case STATIC_CAST_EXPR: | |
5660 | case REINTERPRET_CAST_EXPR: | |
5661 | case IMPLICIT_CONV_EXPR: | |
5662 | if (cxx_dialect < cxx11 | |
5663 | && !dependent_type_p (TREE_TYPE (t)) | |
5664 | && !INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))) | |
5665 | /* In C++98, a conversion to non-integral type can't be part of a | |
5666 | constant expression. */ | |
5667 | { | |
5668 | if (flags & tf_error) | |
e40b6fc7 JJ |
5669 | error_at (loc, |
5670 | "cast to non-integral type %qT in a constant expression", | |
5671 | TREE_TYPE (t)); | |
2d76680f PC |
5672 | return false; |
5673 | } | |
5674 | ||
69eb4fde JM |
5675 | return (RECUR (TREE_OPERAND (t, 0), |
5676 | TREE_CODE (TREE_TYPE (t)) != REFERENCE_TYPE)); | |
2d76680f | 5677 | |
60813a46 | 5678 | case BIND_EXPR: |
69eb4fde | 5679 | return RECUR (BIND_EXPR_BODY (t), want_rval); |
60813a46 | 5680 | |
60813a46 JM |
5681 | case CLEANUP_POINT_EXPR: |
5682 | case MUST_NOT_THROW_EXPR: | |
5683 | case TRY_CATCH_EXPR: | |
769430b2 | 5684 | case TRY_BLOCK: |
60813a46 JM |
5685 | case EH_SPEC_BLOCK: |
5686 | case EXPR_STMT: | |
2d76680f PC |
5687 | case PAREN_EXPR: |
5688 | case NON_DEPENDENT_EXPR: | |
5689 | /* For convenience. */ | |
5690 | case RETURN_EXPR: | |
f937929e JM |
5691 | case LOOP_EXPR: |
5692 | case EXIT_EXPR: | |
69eb4fde | 5693 | return RECUR (TREE_OPERAND (t, 0), want_rval); |
2d76680f | 5694 | |
98e5a19a JM |
5695 | case DECL_EXPR: |
5696 | tmp = DECL_EXPR_DECL (t); | |
5697 | if (VAR_P (tmp) && !DECL_ARTIFICIAL (tmp)) | |
5698 | { | |
5699 | if (TREE_STATIC (tmp)) | |
5700 | { | |
5701 | if (flags & tf_error) | |
5702 | error_at (DECL_SOURCE_LOCATION (tmp), "%qD declared " | |
4b691b13 | 5703 | "%<static%> in %<constexpr%> context", tmp); |
98e5a19a JM |
5704 | return false; |
5705 | } | |
5706 | else if (CP_DECL_THREAD_LOCAL_P (tmp)) | |
5707 | { | |
5708 | if (flags & tf_error) | |
5709 | error_at (DECL_SOURCE_LOCATION (tmp), "%qD declared " | |
4b691b13 | 5710 | "%<thread_local%> in %<constexpr%> context", tmp); |
98e5a19a JM |
5711 | return false; |
5712 | } | |
5713 | else if (!DECL_NONTRIVIALLY_INITIALIZED_P (tmp)) | |
5714 | { | |
5715 | if (flags & tf_error) | |
5716 | error_at (DECL_SOURCE_LOCATION (tmp), "uninitialized " | |
4b691b13 | 5717 | "variable %qD in %<constexpr%> context", tmp); |
98e5a19a JM |
5718 | return false; |
5719 | } | |
5720 | } | |
5721 | return RECUR (tmp, want_rval); | |
5722 | ||
769430b2 JM |
5723 | case TRY_FINALLY_EXPR: |
5724 | return (RECUR (TREE_OPERAND (t, 0), want_rval) | |
5725 | && RECUR (TREE_OPERAND (t, 1), any)); | |
5726 | ||
2d76680f | 5727 | case SCOPE_REF: |
69eb4fde | 5728 | return RECUR (TREE_OPERAND (t, 1), want_rval); |
2d76680f PC |
5729 | |
5730 | case TARGET_EXPR: | |
5731 | if (!literal_type_p (TREE_TYPE (t))) | |
5732 | { | |
5733 | if (flags & tf_error) | |
5734 | { | |
e40b6fc7 JJ |
5735 | error_at (loc, "temporary of non-literal type %qT in a " |
5736 | "constant expression", TREE_TYPE (t)); | |
2d76680f PC |
5737 | explain_non_literal_class (TREE_TYPE (t)); |
5738 | } | |
5739 | return false; | |
5740 | } | |
191816a3 | 5741 | /* FALLTHRU */ |
2d76680f | 5742 | case INIT_EXPR: |
69eb4fde | 5743 | return RECUR (TREE_OPERAND (t, 1), rval); |
2d76680f PC |
5744 | |
5745 | case CONSTRUCTOR: | |
5746 | { | |
5747 | vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (t); | |
5748 | constructor_elt *ce; | |
5749 | for (i = 0; vec_safe_iterate (v, i, &ce); ++i) | |
69eb4fde | 5750 | if (!RECUR (ce->value, want_rval)) |
2d76680f PC |
5751 | return false; |
5752 | return true; | |
5753 | } | |
5754 | ||
5755 | case TREE_LIST: | |
5756 | { | |
5757 | gcc_assert (TREE_PURPOSE (t) == NULL_TREE | |
5758 | || DECL_P (TREE_PURPOSE (t))); | |
69eb4fde | 5759 | if (!RECUR (TREE_VALUE (t), want_rval)) |
2d76680f PC |
5760 | return false; |
5761 | if (TREE_CHAIN (t) == NULL_TREE) | |
5762 | return true; | |
69eb4fde | 5763 | return RECUR (TREE_CHAIN (t), want_rval); |
2d76680f PC |
5764 | } |
5765 | ||
5766 | case TRUNC_DIV_EXPR: | |
5767 | case CEIL_DIV_EXPR: | |
5768 | case FLOOR_DIV_EXPR: | |
5769 | case ROUND_DIV_EXPR: | |
5770 | case TRUNC_MOD_EXPR: | |
5771 | case CEIL_MOD_EXPR: | |
5772 | case ROUND_MOD_EXPR: | |
5773 | { | |
5774 | tree denom = TREE_OPERAND (t, 1); | |
69eb4fde | 5775 | if (!RECUR (denom, rval)) |
2d76680f PC |
5776 | return false; |
5777 | /* We can't call cxx_eval_outermost_constant_expr on an expression | |
234bef96 | 5778 | that hasn't been through instantiate_non_dependent_expr yet. */ |
2d76680f PC |
5779 | if (!processing_template_decl) |
5780 | denom = cxx_eval_outermost_constant_expr (denom, true); | |
5781 | if (integer_zerop (denom)) | |
5782 | { | |
5783 | if (flags & tf_error) | |
64d6d399 | 5784 | error ("division by zero is not a constant expression"); |
2d76680f PC |
5785 | return false; |
5786 | } | |
5787 | else | |
5788 | { | |
5789 | want_rval = true; | |
69eb4fde | 5790 | return RECUR (TREE_OPERAND (t, 0), want_rval); |
2d76680f PC |
5791 | } |
5792 | } | |
5793 | ||
5794 | case COMPOUND_EXPR: | |
5795 | { | |
5796 | /* check_return_expr sometimes wraps a TARGET_EXPR in a | |
5797 | COMPOUND_EXPR; don't get confused. Also handle EMPTY_CLASS_EXPR | |
5798 | introduced by build_call_a. */ | |
5799 | tree op0 = TREE_OPERAND (t, 0); | |
5800 | tree op1 = TREE_OPERAND (t, 1); | |
5801 | STRIP_NOPS (op1); | |
5802 | if ((TREE_CODE (op0) == TARGET_EXPR && op1 == TARGET_EXPR_SLOT (op0)) | |
5803 | || TREE_CODE (op1) == EMPTY_CLASS_EXPR) | |
69eb4fde | 5804 | return RECUR (op0, want_rval); |
2d76680f PC |
5805 | else |
5806 | goto binary; | |
5807 | } | |
5808 | ||
5809 | /* If the first operand is the non-short-circuit constant, look at | |
5810 | the second operand; otherwise we only care about the first one for | |
5811 | potentiality. */ | |
5812 | case TRUTH_AND_EXPR: | |
5813 | case TRUTH_ANDIF_EXPR: | |
5814 | tmp = boolean_true_node; | |
5815 | goto truth; | |
5816 | case TRUTH_OR_EXPR: | |
5817 | case TRUTH_ORIF_EXPR: | |
5818 | tmp = boolean_false_node; | |
5819 | truth: | |
5820 | { | |
5821 | tree op = TREE_OPERAND (t, 0); | |
69eb4fde | 5822 | if (!RECUR (op, rval)) |
2d76680f PC |
5823 | return false; |
5824 | if (!processing_template_decl) | |
5825 | op = cxx_eval_outermost_constant_expr (op, true); | |
5826 | if (tree_int_cst_equal (op, tmp)) | |
69eb4fde | 5827 | return RECUR (TREE_OPERAND (t, 1), rval); |
2d76680f PC |
5828 | else |
5829 | return true; | |
5830 | } | |
5831 | ||
5832 | case PLUS_EXPR: | |
5833 | case MULT_EXPR: | |
5834 | case POINTER_PLUS_EXPR: | |
5835 | case RDIV_EXPR: | |
5836 | case EXACT_DIV_EXPR: | |
5837 | case MIN_EXPR: | |
5838 | case MAX_EXPR: | |
5839 | case LSHIFT_EXPR: | |
5840 | case RSHIFT_EXPR: | |
5841 | case LROTATE_EXPR: | |
5842 | case RROTATE_EXPR: | |
5843 | case BIT_IOR_EXPR: | |
5844 | case BIT_XOR_EXPR: | |
5845 | case BIT_AND_EXPR: | |
5846 | case TRUTH_XOR_EXPR: | |
5847 | case UNORDERED_EXPR: | |
5848 | case ORDERED_EXPR: | |
5849 | case UNLT_EXPR: | |
5850 | case UNLE_EXPR: | |
5851 | case UNGT_EXPR: | |
5852 | case UNGE_EXPR: | |
5853 | case UNEQ_EXPR: | |
5854 | case LTGT_EXPR: | |
5855 | case RANGE_EXPR: | |
5856 | case COMPLEX_EXPR: | |
5857 | want_rval = true; | |
5858 | /* Fall through. */ | |
5859 | case ARRAY_REF: | |
5860 | case ARRAY_RANGE_REF: | |
5861 | case MEMBER_REF: | |
5862 | case DOTSTAR_EXPR: | |
41b38772 | 5863 | case MEM_REF: |
4856a1f0 PC |
5864 | case BINARY_LEFT_FOLD_EXPR: |
5865 | case BINARY_RIGHT_FOLD_EXPR: | |
2d76680f PC |
5866 | binary: |
5867 | for (i = 0; i < 2; ++i) | |
69eb4fde | 5868 | if (!RECUR (TREE_OPERAND (t, i), want_rval)) |
2d76680f PC |
5869 | return false; |
5870 | return true; | |
5871 | ||
2d76680f PC |
5872 | case FMA_EXPR: |
5873 | case VEC_PERM_EXPR: | |
5874 | for (i = 0; i < 3; ++i) | |
69eb4fde | 5875 | if (!RECUR (TREE_OPERAND (t, i), true)) |
2d76680f PC |
5876 | return false; |
5877 | return true; | |
5878 | ||
5879 | case COND_EXPR: | |
d5bcd6d4 JM |
5880 | if (COND_EXPR_IS_VEC_DELETE (t)) |
5881 | { | |
5882 | if (flags & tf_error) | |
e40b6fc7 | 5883 | error_at (loc, "%<delete[]%> is not a constant expression"); |
d5bcd6d4 JM |
5884 | return false; |
5885 | } | |
5886 | /* Fall through. */ | |
5887 | case IF_STMT: | |
2d76680f PC |
5888 | case VEC_COND_EXPR: |
5889 | /* If the condition is a known constant, we know which of the legs we | |
5890 | care about; otherwise we only require that the condition and | |
5891 | either of the legs be potentially constant. */ | |
5892 | tmp = TREE_OPERAND (t, 0); | |
69eb4fde | 5893 | if (!RECUR (tmp, rval)) |
2d76680f PC |
5894 | return false; |
5895 | if (!processing_template_decl) | |
5896 | tmp = cxx_eval_outermost_constant_expr (tmp, true); | |
5897 | if (integer_zerop (tmp)) | |
69eb4fde | 5898 | return RECUR (TREE_OPERAND (t, 2), want_rval); |
2d76680f | 5899 | else if (TREE_CODE (tmp) == INTEGER_CST) |
69eb4fde | 5900 | return RECUR (TREE_OPERAND (t, 1), want_rval); |
2d76680f PC |
5901 | for (i = 1; i < 3; ++i) |
5902 | if (potential_constant_expression_1 (TREE_OPERAND (t, i), | |
a0ab7ccd | 5903 | want_rval, strict, now, tf_none)) |
2d76680f PC |
5904 | return true; |
5905 | if (flags & tf_error) | |
e40b6fc7 | 5906 | error_at (loc, "expression %qE is not a constant expression", t); |
2d76680f PC |
5907 | return false; |
5908 | ||
5909 | case VEC_INIT_EXPR: | |
5910 | if (VEC_INIT_EXPR_IS_CONSTEXPR (t)) | |
5911 | return true; | |
5912 | if (flags & tf_error) | |
5913 | { | |
e40b6fc7 | 5914 | error_at (loc, "non-constant array initialization"); |
2d76680f PC |
5915 | diagnose_non_constexpr_vec_init (t); |
5916 | } | |
5917 | return false; | |
5918 | ||
133bc698 JM |
5919 | case TYPE_DECL: |
5920 | case TAG_DEFN: | |
5921 | /* We can see these in statement-expressions. */ | |
5922 | return true; | |
5923 | ||
baf9ebc8 | 5924 | case CLEANUP_STMT: |
cda0a029 | 5925 | case EMPTY_CLASS_EXPR: |
7fef86d3 | 5926 | case PREDICT_EXPR: |
cda0a029 JM |
5927 | return false; |
5928 | ||
f937929e JM |
5929 | case GOTO_EXPR: |
5930 | { | |
5931 | tree *target = &TREE_OPERAND (t, 0); | |
ab3af181 JJ |
5932 | /* Gotos representing break and continue are OK. */ |
5933 | if (breaks (target) || continues (target)) | |
5934 | return true; | |
5935 | if (flags & tf_error) | |
e40b6fc7 | 5936 | error_at (loc, "%<goto%> is not a constant expression"); |
ab3af181 | 5937 | return false; |
f937929e JM |
5938 | } |
5939 | ||
98e09245 | 5940 | case ANNOTATE_EXPR: |
98e09245 JJ |
5941 | return RECUR (TREE_OPERAND (t, 0), rval); |
5942 | ||
2d76680f PC |
5943 | default: |
5944 | if (objc_is_property_ref (t)) | |
5945 | return false; | |
5946 | ||
5947 | sorry ("unexpected AST of kind %s", get_tree_code_name (TREE_CODE (t))); | |
ab3af181 | 5948 | gcc_unreachable (); |
2d76680f PC |
5949 | return false; |
5950 | } | |
69eb4fde | 5951 | #undef RECUR |
2d76680f PC |
5952 | } |
5953 | ||
5954 | /* The main entry point to the above. */ | |
5955 | ||
5956 | bool | |
5957 | potential_constant_expression (tree t) | |
5958 | { | |
a0ab7ccd | 5959 | return potential_constant_expression_1 (t, false, true, false, tf_none); |
2d76680f PC |
5960 | } |
5961 | ||
5962 | /* As above, but require a constant rvalue. */ | |
5963 | ||
5964 | bool | |
5965 | potential_rvalue_constant_expression (tree t) | |
5966 | { | |
a0ab7ccd | 5967 | return potential_constant_expression_1 (t, true, true, false, tf_none); |
2d76680f PC |
5968 | } |
5969 | ||
5970 | /* Like above, but complain about non-constant expressions. */ | |
5971 | ||
5972 | bool | |
5973 | require_potential_constant_expression (tree t) | |
5974 | { | |
a0ab7ccd | 5975 | return potential_constant_expression_1 (t, false, true, false, tf_warning_or_error); |
2d76680f PC |
5976 | } |
5977 | ||
5978 | /* Cross product of the above. */ | |
5979 | ||
5980 | bool | |
5981 | require_potential_rvalue_constant_expression (tree t) | |
5982 | { | |
a0ab7ccd JM |
5983 | return potential_constant_expression_1 (t, true, true, false, tf_warning_or_error); |
5984 | } | |
5985 | ||
5986 | /* Like potential_constant_expression, but don't consider possible constexpr | |
5987 | substitution of the current function. That is, PARM_DECL qualifies under | |
5988 | potential_constant_expression, but not here. | |
5989 | ||
5990 | This is basically what you can check when any actual constant values might | |
5991 | be value-dependent. */ | |
5992 | ||
5993 | bool | |
5994 | is_constant_expression (tree t) | |
5995 | { | |
5996 | return potential_constant_expression_1 (t, false, true, true, tf_none); | |
5997 | } | |
5998 | ||
5999 | /* Like above, but complain about non-constant expressions. */ | |
6000 | ||
6001 | bool | |
6002 | require_constant_expression (tree t) | |
6003 | { | |
6004 | return potential_constant_expression_1 (t, false, true, true, | |
6005 | tf_warning_or_error); | |
6006 | } | |
6007 | ||
6008 | /* Like is_constant_expression, but allow const variables that are not allowed | |
6009 | under constexpr rules. */ | |
6010 | ||
6011 | bool | |
6012 | is_static_init_expression (tree t) | |
6013 | { | |
6014 | return potential_constant_expression_1 (t, false, false, true, tf_none); | |
2d76680f PC |
6015 | } |
6016 | ||
eb07f187 JM |
6017 | /* Returns true if T is a potential constant expression that is not |
6018 | instantiation-dependent, and therefore a candidate for constant folding even | |
6019 | in a template. */ | |
6020 | ||
6021 | bool | |
a0ab7ccd | 6022 | is_nondependent_constant_expression (tree t) |
eb07f187 JM |
6023 | { |
6024 | return (!type_unknown_p (t) | |
6025 | && !BRACE_ENCLOSED_INITIALIZER_P (t) | |
a0ab7ccd | 6026 | && is_constant_expression (t) |
eb07f187 JM |
6027 | && !instantiation_dependent_expression_p (t)); |
6028 | } | |
6029 | ||
6030 | /* Returns true if T is a potential static initializer expression that is not | |
6031 | instantiation-dependent. */ | |
6032 | ||
6033 | bool | |
a0ab7ccd | 6034 | is_nondependent_static_init_expression (tree t) |
eb07f187 JM |
6035 | { |
6036 | return (!type_unknown_p (t) | |
6037 | && !BRACE_ENCLOSED_INITIALIZER_P (t) | |
a0ab7ccd | 6038 | && is_static_init_expression (t) |
eb07f187 JM |
6039 | && !instantiation_dependent_expression_p (t)); |
6040 | } | |
6041 | ||
97f3003f JM |
6042 | /* Finalize constexpr processing after parsing. */ |
6043 | ||
6044 | void | |
6045 | fini_constexpr (void) | |
6046 | { | |
6047 | /* The contexpr call and fundef copies tables are no longer needed. */ | |
6048 | constexpr_call_table = NULL; | |
6049 | fundef_copies_table = NULL; | |
6050 | } | |
6051 | ||
2d76680f | 6052 | #include "gt-cp-constexpr.h" |