Line data Source code
1 : // This file is part of GCC.
2 :
3 : // GCC is free software; you can redistribute it and/or modify it under
4 : // the terms of the GNU General Public License as published by the Free
5 : // Software Foundation; either version 3, or (at your option) any later
6 : // version.
7 :
8 : // GCC is distributed in the hope that it will be useful, but WITHOUT ANY
9 : // WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 : // FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
11 : // for more details.
12 :
13 : // You should have received a copy of the GNU General Public License
14 : // along with GCC; see the file COPYING3. If not see
15 : // <http://www.gnu.org/licenses/>.
16 :
17 : #include "rust-constexpr.h"
18 : #include "rust-location.h"
19 : #include "rust-diagnostics.h"
20 : #include "rust-tree.h"
21 : #include "fold-const.h"
22 : #include "realmpfr.h"
23 : #include "convert.h"
24 : #include "print-tree.h"
25 : #include "tree-pretty-print.h"
26 : #include "gimplify.h"
27 : #include "tree-iterator.h"
28 : #include "timevar.h"
29 : #include "varasm.h"
30 : #include "cgraph.h"
31 : #include "tree-inline.h"
32 : #include "vec.h"
33 : #include "function.h"
34 : #include "diagnostic.h"
35 : #include "target.h"
36 : #include "builtins.h"
37 :
38 : #define VERIFY_CONSTANT(X) \
39 : do \
40 : { \
41 : if (verify_constant ((X), ctx->quiet, non_constant_p, overflow_p)) \
42 : return t; \
43 : } \
44 : while (0)
45 :
46 : namespace Rust {
47 : namespace Compile {
48 :
49 : /* Returns true iff FUN is an instantiation of a constexpr function
50 : template or a defaulted constexpr function. */
51 :
52 : bool
53 0 : is_instantiation_of_constexpr (tree fun)
54 : {
55 0 : return DECL_DECLARED_CONSTEXPR_P (fun);
56 : }
57 :
58 : /* Return true if T is a literal type. */
59 :
60 : bool
61 0 : literal_type_p (tree t)
62 : {
63 0 : if (SCALAR_TYPE_P (t) || VECTOR_TYPE_P (t) || TYPE_REF_P (t)
64 : || (VOID_TYPE_P (t)))
65 0 : return true;
66 :
67 : if (TREE_CODE (t) == ARRAY_TYPE)
68 0 : return literal_type_p (strip_array_types (t));
69 : return false;
70 : }
71 :
72 : static bool verify_constant (tree, bool, bool *, bool *);
73 :
74 : static HOST_WIDE_INT find_array_ctor_elt (tree ary, tree dindex,
75 : bool insert = false);
76 : static int array_index_cmp (tree key, tree index);
77 : static bool potential_constant_expression_1 (tree t, bool want_rval,
78 : bool strict, bool now,
79 : tsubst_flags_t flags,
80 : tree *jump_target);
81 : bool potential_constant_expression_1 (tree t, bool want_rval, bool strict,
82 : bool now, tsubst_flags_t flags);
83 : tree unshare_constructor (tree t MEM_STAT_DECL);
84 : void maybe_save_constexpr_fundef (tree fun);
85 :
86 : static bool returns (tree *jump_target);
87 : static bool breaks (tree *jump_target);
88 : static bool continues (tree *jump_target);
89 : static bool switches (tree *jump_target);
90 :
91 5452 : struct constexpr_global_ctx
92 : {
93 : /* Values for any temporaries or local variables within the
94 : constant-expression. */
95 : hash_map<tree, tree> values;
96 : /* Number of cxx_eval_constant_expression calls (except skipped ones,
97 : on simple constants or location wrappers) encountered during current
98 : cxx_eval_outermost_constant_expr call. */
99 : HOST_WIDE_INT constexpr_ops_count;
100 : /* Heap VAR_DECLs created during the evaluation of the outermost constant
101 : expression. */
102 : auto_vec<tree, 16> heap_vars;
103 : /* Cleanups that need to be evaluated at the end of CLEANUP_POINT_EXPR. */
104 : vec<tree> *cleanups;
105 : /* If non-null, only allow modification of existing values of the variables
106 : in this set. Set by modifiable_tracker, below. */
107 : hash_set<tree> *modifiable;
108 : /* Number of heap VAR_DECL deallocations. */
109 : unsigned heap_dealloc_count;
110 : /* Constructor. */
111 5452 : constexpr_global_ctx ()
112 5452 : : constexpr_ops_count (0), cleanups (NULL), heap_dealloc_count (0)
113 5452 : {}
114 :
115 151 : tree get_value (tree t)
116 : {
117 151 : if (tree *p = values.get (t))
118 150 : if (*p != void_node)
119 150 : return *p;
120 : return NULL_TREE;
121 : }
122 : tree *get_value_ptr (tree t, bool initializing)
123 : {
124 : if (modifiable && !modifiable->contains (t))
125 : return nullptr;
126 : if (tree *p = values.get (t))
127 : {
128 : if (*p != void_node)
129 : return p;
130 : else if (initializing)
131 : {
132 : *p = NULL_TREE;
133 : return p;
134 : }
135 : }
136 : return nullptr;
137 : }
138 : void put_value (tree t, tree v)
139 : {
140 : bool already_in_map = values.put (t, v);
141 : if (!already_in_map && modifiable)
142 : modifiable->add (t);
143 : }
144 : void destroy_value (tree t)
145 : {
146 : if (TREE_CODE (t) == VAR_DECL || TREE_CODE (t) == PARM_DECL
147 : || TREE_CODE (t) == RESULT_DECL)
148 : values.put (t, void_node);
149 : else
150 : values.remove (t);
151 : }
152 : void clear_value (tree t) { values.remove (t); }
153 : };
154 :
155 : /* In constexpr.cc */
156 : /* Representation of entries in the constexpr function definition table. */
157 :
158 : struct GTY ((for_user)) rust_constexpr_fundef
159 : {
160 : tree decl;
161 : tree body;
162 : tree parms;
163 : tree result;
164 : };
165 :
166 : /* Objects of this type represent calls to constexpr functions
167 : along with the bindings of parameters to their arguments, for
168 : the purpose of compile time evaluation. */
169 :
170 : struct GTY ((for_user)) rust_constexpr_call
171 : {
172 : /* Description of the constexpr function definition. */
173 : rust_constexpr_fundef *fundef;
174 : /* Parameter bindings environment. A TREE_VEC of arguments. */
175 : tree bindings;
176 : /* Result of the call.
177 : NULL means the call is being evaluated.
178 : error_mark_node means that the evaluation was erroneous;
179 : otherwise, the actual value of the call. */
180 : tree result;
181 : /* The hash of this call; we remember it here to avoid having to
182 : recalculate it when expanding the hash table. */
183 : hashval_t hash;
184 : /* Whether __builtin_is_constant_evaluated() should evaluate to true. */
185 : bool manifestly_const_eval;
186 : };
187 :
188 : struct rust_constexpr_call_hasher : ggc_ptr_hash<rust_constexpr_call>
189 : {
190 : static hashval_t hash (rust_constexpr_call *);
191 : static bool equal (rust_constexpr_call *, rust_constexpr_call *);
192 : };
193 :
194 : enum constexpr_switch_state
195 : {
196 : /* Used when processing a switch for the first time by cxx_eval_switch_expr
197 : and default: label for that switch has not been seen yet. */
198 : css_default_not_seen,
199 : /* Used when processing a switch for the first time by cxx_eval_switch_expr
200 : and default: label for that switch has been seen already. */
201 : css_default_seen,
202 : /* Used when processing a switch for the second time by
203 : cxx_eval_switch_expr, where default: label should match. */
204 : css_default_processing
205 : };
206 :
207 : struct constexpr_ctx
208 : {
209 : /* The part of the context that needs to be unique to the whole
210 : cxx_eval_outermost_constant_expr invocation. */
211 : constexpr_global_ctx *global;
212 : /* The innermost call we're evaluating. */
213 : rust_constexpr_call *call;
214 : /* SAVE_EXPRs and TARGET_EXPR_SLOT vars of TARGET_EXPRs that we've seen
215 : within the current LOOP_EXPR. NULL if we aren't inside a loop. */
216 : vec<tree> *save_exprs;
217 : /* The CONSTRUCTOR we're currently building up for an aggregate
218 : initializer. */
219 : tree ctor;
220 : /* The object we're building the CONSTRUCTOR for. */
221 : tree object;
222 : /* If inside SWITCH_EXPR. */
223 : constexpr_switch_state *css_state;
224 : /* The aggregate initialization context inside which this one is nested. This
225 : is used by lookup_placeholder to resolve PLACEHOLDER_EXPRs. */
226 : const constexpr_ctx *parent;
227 :
228 : /* Whether we should error on a non-constant expression or fail quietly.
229 : This flag needs to be here, but some of the others could move to global
230 : if they get larger than a word. */
231 : bool quiet;
232 : /* Whether we are strictly conforming to constant expression rules or
233 : trying harder to get a constant value. */
234 : bool strict;
235 : /* Whether __builtin_is_constant_evaluated () should be true. */
236 : bool manifestly_const_eval;
237 : };
238 :
239 : struct rust_constexpr_fundef_hasher : ggc_ptr_hash<rust_constexpr_fundef>
240 : {
241 : static hashval_t hash (const rust_constexpr_fundef *);
242 : static bool equal (const rust_constexpr_fundef *,
243 : const rust_constexpr_fundef *);
244 : };
245 :
246 : /* This table holds all constexpr function definitions seen in
247 : the current translation unit. */
248 :
249 : static GTY (())
250 : hash_table<rust_constexpr_fundef_hasher> *constexpr_fundef_table;
251 :
252 : /* Utility function used for managing the constexpr function table.
253 : Return true if the entries pointed to by P and Q are for the
254 : same constexpr function. */
255 :
256 : inline bool
257 10848 : rust_constexpr_fundef_hasher::equal (const rust_constexpr_fundef *lhs,
258 : const rust_constexpr_fundef *rhs)
259 : {
260 10848 : return lhs->decl == rhs->decl;
261 : }
262 :
263 : /* Utility function used for managing the constexpr function table.
264 : Return a hash value for the entry pointed to by Q. */
265 :
266 : inline hashval_t
267 18052 : rust_constexpr_fundef_hasher::hash (const rust_constexpr_fundef *fundef)
268 : {
269 18052 : return DECL_UID (fundef->decl);
270 : }
271 :
272 : /* Return a previously saved definition of function FUN. */
273 :
274 : rust_constexpr_fundef *
275 2405 : retrieve_constexpr_fundef (tree fun)
276 : {
277 2405 : if (constexpr_fundef_table == NULL)
278 : return NULL;
279 :
280 2405 : rust_constexpr_fundef fundef = {fun, NULL_TREE, NULL_TREE, NULL_TREE};
281 2405 : return constexpr_fundef_table->find (&fundef);
282 : }
283 :
284 : /* This internal flag controls whether we should avoid doing anything during
285 : constexpr evaluation that would cause extra DECL_UID generation, such as
286 : template instantiation and function body copying. */
287 :
288 : static bool uid_sensitive_constexpr_evaluation_value;
289 :
290 : /* An internal counter that keeps track of the number of times
291 : uid_sensitive_constexpr_evaluation_p returned true. */
292 :
293 : static unsigned uid_sensitive_constexpr_evaluation_true_counter;
294 :
295 : /* The accessor for uid_sensitive_constexpr_evaluation_value which also
296 : increments the corresponding counter. */
297 :
298 : static bool
299 0 : uid_sensitive_constexpr_evaluation_p ()
300 : {
301 0 : if (uid_sensitive_constexpr_evaluation_value)
302 : {
303 0 : ++uid_sensitive_constexpr_evaluation_true_counter;
304 0 : return true;
305 : }
306 : else
307 : return false;
308 : }
309 :
310 : /* RAII sentinel that saves the value of a variable, optionally
311 : overrides it right away, and restores its value when the sentinel
312 : id destructed. */
313 :
314 : template <typename T> class temp_override
315 : {
316 : T &overridden_variable;
317 : T saved_value;
318 :
319 : public:
320 0 : temp_override (T &var) : overridden_variable (var), saved_value (var) {}
321 0 : temp_override (T &var, T overrider)
322 0 : : overridden_variable (var), saved_value (var)
323 : {
324 0 : overridden_variable = overrider;
325 : }
326 0 : ~temp_override () { overridden_variable = saved_value; }
327 : };
328 :
329 : /* An RAII sentinel used to restrict constexpr evaluation so that it
330 : doesn't do anything that causes extra DECL_UID generation. */
331 :
332 : struct uid_sensitive_constexpr_evaluation_sentinel
333 : {
334 : temp_override<bool> ovr;
335 : uid_sensitive_constexpr_evaluation_sentinel ();
336 : };
337 :
338 : /* Used to determine whether uid_sensitive_constexpr_evaluation_p was
339 : called and returned true, indicating that we've restricted constexpr
340 : evaluation in order to avoid UID generation. We use this to control
341 : updates to the fold_cache and cv_cache. */
342 :
343 : struct uid_sensitive_constexpr_evaluation_checker
344 : {
345 : const unsigned saved_counter;
346 : uid_sensitive_constexpr_evaluation_checker ();
347 : bool evaluation_restricted_p () const;
348 : };
349 :
350 : /* The default constructor for uid_sensitive_constexpr_evaluation_sentinel
351 : enables the internal flag for uid_sensitive_constexpr_evaluation_p
352 : during the lifetime of the sentinel object. Upon its destruction, the
353 : previous value of uid_sensitive_constexpr_evaluation_p is restored. */
354 :
355 0 : uid_sensitive_constexpr_evaluation_sentinel ::
356 : uid_sensitive_constexpr_evaluation_sentinel ()
357 0 : : ovr (uid_sensitive_constexpr_evaluation_value, true)
358 0 : {}
359 :
360 : /* The default constructor for uid_sensitive_constexpr_evaluation_checker
361 : records the current number of times that uid_sensitive_constexpr_evaluation_p
362 : has been called and returned true. */
363 :
364 0 : uid_sensitive_constexpr_evaluation_checker ::
365 : uid_sensitive_constexpr_evaluation_checker ()
366 0 : : saved_counter (uid_sensitive_constexpr_evaluation_true_counter)
367 0 : {}
368 :
369 : /* Returns true iff uid_sensitive_constexpr_evaluation_p is true, and
370 : some constexpr evaluation was restricted due to u_s_c_e_p being called
371 : and returning true during the lifetime of this checker object. */
372 :
373 : bool
374 0 : uid_sensitive_constexpr_evaluation_checker::evaluation_restricted_p () const
375 : {
376 0 : return (uid_sensitive_constexpr_evaluation_value
377 0 : && saved_counter != uid_sensitive_constexpr_evaluation_true_counter);
378 : }
379 :
380 : /* A table of all constexpr calls that have been evaluated by the
381 : compiler in this translation unit. */
382 :
383 : static GTY (()) hash_table<rust_constexpr_call_hasher> *constexpr_call_table;
384 :
385 : /* Compute a hash value for a constexpr call representation. */
386 :
387 : inline hashval_t
388 3450 : rust_constexpr_call_hasher::hash (rust_constexpr_call *info)
389 : {
390 3450 : return info->hash;
391 : }
392 :
393 : /* Return true if the objects pointed to by P and Q represent calls
394 : to the same constexpr function with the same arguments.
395 : Otherwise, return false. */
396 :
397 : bool
398 1176 : rust_constexpr_call_hasher::equal (rust_constexpr_call *lhs,
399 : rust_constexpr_call *rhs)
400 : {
401 1176 : if (lhs == rhs)
402 : return true;
403 1176 : if (lhs->hash != rhs->hash)
404 : return false;
405 0 : if (lhs->manifestly_const_eval != rhs->manifestly_const_eval)
406 : return false;
407 0 : if (!rust_constexpr_fundef_hasher::equal (lhs->fundef, rhs->fundef))
408 : return false;
409 0 : return rs_tree_equal (lhs->bindings, rhs->bindings);
410 : }
411 :
412 : /* Initialize the constexpr call table, if needed. */
413 :
414 : static void
415 2405 : maybe_initialize_constexpr_call_table (void)
416 : {
417 2405 : if (constexpr_call_table == NULL)
418 634 : constexpr_call_table
419 634 : = hash_table<rust_constexpr_call_hasher>::create_ggc (101);
420 2405 : }
421 :
422 : /* During constexpr CALL_EXPR evaluation, to avoid issues with sharing when
423 : a function happens to get called recursively, we unshare the callee
424 : function's body and evaluate this unshared copy instead of evaluating the
425 : original body.
426 :
427 : FUNDEF_COPIES_TABLE is a per-function freelist of these unshared function
428 : copies. The underlying data structure of FUNDEF_COPIES_TABLE is a hash_map
429 : that's keyed off of the original FUNCTION_DECL and whose value is a
430 : TREE_LIST of this function's unused copies awaiting reuse.
431 :
432 : This is not GC-deletable to avoid GC affecting UID generation. */
433 :
434 : static GTY (()) decl_tree_map *fundef_copies_table;
435 :
436 : /* Reuse a copy or create a new unshared copy of the function FUN.
437 : Return this copy. We use a TREE_LIST whose PURPOSE is body, VALUE
438 : is parms, TYPE is result. */
439 :
440 : static tree
441 2405 : get_fundef_copy (rust_constexpr_fundef *fundef)
442 : {
443 2405 : tree copy;
444 2405 : bool existed;
445 2405 : tree *slot
446 2405 : = &(hash_map_safe_get_or_insert<hm_ggc> (fundef_copies_table, fundef->decl,
447 : &existed, 127));
448 :
449 2405 : if (!existed)
450 : {
451 : /* There is no cached function available, or in use. We can use
452 : the function directly. That the slot is now created records
453 : that this function is now in use. */
454 2401 : copy = build_tree_list (fundef->body, fundef->parms);
455 2401 : TREE_TYPE (copy) = fundef->result;
456 : }
457 4 : else if (*slot == NULL_TREE)
458 : {
459 0 : if (uid_sensitive_constexpr_evaluation_p ())
460 0 : return NULL_TREE;
461 :
462 : /* We've already used the function itself, so make a copy. */
463 0 : copy = build_tree_list (NULL, NULL);
464 0 : tree saved_body = DECL_SAVED_TREE (fundef->decl);
465 0 : tree saved_parms = DECL_ARGUMENTS (fundef->decl);
466 0 : tree saved_result = DECL_RESULT (fundef->decl);
467 0 : tree saved_fn = current_function_decl;
468 0 : DECL_SAVED_TREE (fundef->decl) = fundef->body;
469 0 : DECL_ARGUMENTS (fundef->decl) = fundef->parms;
470 0 : DECL_RESULT (fundef->decl) = fundef->result;
471 0 : current_function_decl = fundef->decl;
472 0 : TREE_PURPOSE (copy)
473 0 : = copy_fn (fundef->decl, TREE_VALUE (copy), TREE_TYPE (copy));
474 0 : current_function_decl = saved_fn;
475 0 : DECL_RESULT (fundef->decl) = saved_result;
476 0 : DECL_ARGUMENTS (fundef->decl) = saved_parms;
477 0 : DECL_SAVED_TREE (fundef->decl) = saved_body;
478 : }
479 : else
480 : {
481 : /* We have a cached function available. */
482 4 : copy = *slot;
483 4 : *slot = TREE_CHAIN (copy);
484 : }
485 :
486 : return copy;
487 : }
488 :
489 : /* Save the copy COPY of function FUN for later reuse by
490 : get_fundef_copy(). By construction, there will always be an entry
491 : to find. */
492 :
493 : static void
494 2405 : save_fundef_copy (tree fun, tree copy)
495 : {
496 2405 : tree *slot = fundef_copies_table->get (fun);
497 2405 : TREE_CHAIN (copy) = *slot;
498 2405 : *slot = copy;
499 2405 : }
500 :
501 : static tree constant_value_1 (tree decl, bool strict_p,
502 : bool return_aggregate_cst_ok_p, bool unshare_p);
503 : static tree decl_really_constant_value (tree decl, bool unshare_p /*= true*/);
504 : tree decl_constant_value (tree decl, bool unshare_p);
505 :
506 : static void non_const_var_error (location_t loc, tree r);
507 :
508 : static tree eval_constant_expression (const constexpr_ctx *ctx, tree, bool,
509 : bool *, bool *, tree *jump_target);
510 :
511 : static tree constexpr_fn_retval (const constexpr_ctx *ctx, tree r);
512 :
513 : static tree eval_store_expression (const constexpr_ctx *ctx, tree r, bool,
514 : bool *, bool *, tree *jump_target);
515 :
516 : static tree eval_call_expression (const constexpr_ctx *ctx, tree r, bool,
517 : bool *, bool *, tree *);
518 :
519 : static tree eval_binary_expression (const constexpr_ctx *ctx, tree r, bool,
520 : bool *, bool *, tree *jump_target);
521 :
522 : static tree get_function_named_in_call (tree t);
523 :
524 : static tree eval_statement_list (const constexpr_ctx *ctx, tree t,
525 : bool *non_constant_p, bool *overflow_p,
526 : tree *jump_target);
527 : static tree extract_string_elt (tree string, unsigned chars_per_elt,
528 : unsigned index);
529 :
530 : static tree eval_conditional_expression (const constexpr_ctx *ctx, tree t,
531 : bool lval, bool *non_constant_p,
532 : bool *overflow_p, tree *jump_target);
533 :
534 : static tree eval_bit_field_ref (const constexpr_ctx *ctx, tree t, bool lval,
535 : bool *non_constant_p, bool *overflow_p,
536 : tree *jump_target);
537 :
538 : static tree eval_loop_expr (const constexpr_ctx *ctx, tree t,
539 : bool *non_constant_p, bool *overflow_p,
540 : tree *jump_target);
541 :
542 : static tree eval_switch_expr (const constexpr_ctx *ctx, tree t,
543 : bool *non_constant_p, bool *overflow_p,
544 : tree *jump_target);
545 :
546 : static tree eval_unary_expression (const constexpr_ctx *ctx, tree t,
547 : bool /*lval*/, bool *non_constant_p,
548 : bool *overflow_p, tree *jump_target);
549 : static bool eval_check_shift_p (location_t loc, const constexpr_ctx *ctx,
550 : enum tree_code code, tree type, tree lhs,
551 : tree rhs);
552 : static bool eval_check_overflow_p (location_t loc, const constexpr_ctx *ctx,
553 : enum tree_code code, tree type, tree lhs,
554 : tree rhs);
555 : static tree fold_pointer_plus_expression (const constexpr_ctx *ctx, tree t,
556 : tree lhs, tree rhs,
557 : bool *non_constant_p,
558 : bool *overflow_p, tree *jump_target);
559 : static tree maybe_fold_addr_pointer_plus (tree t);
560 : static tree maybe_fold_reference_address_to_pointer (tree t);
561 :
562 : /* Variables and functions to manage constexpr call expansion context.
563 : These do not need to be marked for PCH or GC. */
564 :
565 : /* FIXME remember and print actual constant arguments. */
566 : static vec<tree> call_stack;
567 : static int call_stack_tick;
568 : static int last_cx_error_tick;
569 :
570 : static int
571 2405 : push_cx_call_context (tree call)
572 : {
573 2405 : ++call_stack_tick;
574 2405 : if (!EXPR_HAS_LOCATION (call))
575 317 : SET_EXPR_LOCATION (call, input_location);
576 2405 : call_stack.safe_push (call);
577 2405 : int len = call_stack.length ();
578 2405 : if (len > max_constexpr_depth)
579 0 : return false;
580 : return len;
581 : }
582 :
583 : static void
584 2405 : pop_cx_call_context (void)
585 : {
586 2405 : ++call_stack_tick;
587 2405 : call_stack.pop ();
588 2405 : }
589 :
590 : vec<tree>
591 0 : cx_error_context (void)
592 : {
593 0 : vec<tree> r = vNULL;
594 0 : if (call_stack_tick != last_cx_error_tick && !call_stack.is_empty ())
595 : r = call_stack;
596 0 : last_cx_error_tick = call_stack_tick;
597 0 : return r;
598 : }
599 :
600 : // this is ported from cxx_eval_outermost_constant_expr
601 : tree
602 5452 : fold_expr (tree expr)
603 : {
604 5452 : bool allow_non_constant = false;
605 5452 : bool strict = true;
606 5452 : bool manifestly_const_eval = false;
607 :
608 5452 : constexpr_global_ctx global_ctx;
609 5452 : constexpr_ctx ctx
610 : = {&global_ctx, NULL,
611 : NULL, NULL,
612 : NULL, NULL,
613 : NULL, allow_non_constant,
614 5452 : strict, manifestly_const_eval || !allow_non_constant};
615 :
616 5452 : auto_vec<tree, 16> cleanups;
617 5452 : global_ctx.cleanups = &cleanups;
618 :
619 5452 : bool non_constant_p = false;
620 5452 : bool overflow_p = false;
621 :
622 5452 : tree jump_target = NULL_TREE;
623 5452 : tree folded = eval_constant_expression (&ctx, expr, false, &non_constant_p,
624 : &overflow_p, &jump_target);
625 5452 : rust_assert (folded != NULL_TREE);
626 :
627 : // more logic here to possibly port
628 5452 : return folded;
629 5452 : }
630 :
631 : static bool
632 45 : same_type_ignoring_tlq_and_bounds_p (tree type1, tree type2)
633 : {
634 45 : while (TREE_CODE (type1) == ARRAY_TYPE && TREE_CODE (type2) == ARRAY_TYPE
635 45 : && (!TYPE_DOMAIN (type1) || !TYPE_DOMAIN (type2)))
636 : {
637 0 : type1 = TREE_TYPE (type1);
638 0 : type2 = TREE_TYPE (type2);
639 : }
640 45 : return same_type_ignoring_top_level_qualifiers_p (type1, type2);
641 : }
642 :
643 : // forked from gcc/cp/constexpr.cc cxx_union_active_member
644 :
645 : /* Try to determine the currently active union member for an expression
646 : with UNION_TYPE. If it can be determined, return the FIELD_DECL,
647 : otherwise return NULL_TREE. */
648 :
649 : static tree
650 0 : union_active_member (const constexpr_ctx *ctx, tree t, tree *jump_target)
651 : {
652 0 : constexpr_ctx new_ctx = *ctx;
653 0 : new_ctx.quiet = true;
654 0 : bool non_constant_p = false, overflow_p = false;
655 0 : tree ctor = eval_constant_expression (&new_ctx, t, false, &non_constant_p,
656 : &overflow_p, jump_target);
657 0 : if (TREE_CODE (ctor) == CONSTRUCTOR && CONSTRUCTOR_NELTS (ctor) == 1
658 0 : && CONSTRUCTOR_ELT (ctor, 0)->index
659 0 : && TREE_CODE (CONSTRUCTOR_ELT (ctor, 0)->index) == FIELD_DECL)
660 : return CONSTRUCTOR_ELT (ctor, 0)->index;
661 : return NULL_TREE;
662 : }
663 :
664 : // forked from gcc/cp/constexpr.cc cxx_fold_indirect_ref_1
665 :
666 : static tree
667 0 : fold_indirect_ref_1 (const constexpr_ctx *ctx, location_t loc, tree type,
668 : tree op, unsigned HOST_WIDE_INT off, bool *empty_base,
669 : tree *jump_target)
670 : {
671 0 : tree optype = TREE_TYPE (op);
672 0 : unsigned HOST_WIDE_INT const_nunits;
673 0 : if (off == 0 && similar_type_p (optype, type))
674 : return op;
675 0 : else if (TREE_CODE (optype) == COMPLEX_TYPE
676 0 : && similar_type_p (type, TREE_TYPE (optype)))
677 : {
678 : /* *(foo *)&complexfoo => __real__ complexfoo */
679 0 : if (off == 0)
680 0 : return build1_loc (loc, REALPART_EXPR, type, op);
681 : /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */
682 0 : else if (tree_to_uhwi (TYPE_SIZE_UNIT (type)) == off)
683 0 : return build1_loc (loc, IMAGPART_EXPR, type, op);
684 : }
685 : /* ((foo*)&vectorfoo)[x] => BIT_FIELD_REF<vectorfoo,...> */
686 0 : else if (VECTOR_TYPE_P (optype) && similar_type_p (type, TREE_TYPE (optype))
687 0 : && TYPE_VECTOR_SUBPARTS (optype).is_constant (&const_nunits))
688 : {
689 0 : unsigned HOST_WIDE_INT part_width = tree_to_uhwi (TYPE_SIZE_UNIT (type));
690 0 : unsigned HOST_WIDE_INT max_offset = part_width * const_nunits;
691 0 : if (off < max_offset && off % part_width == 0)
692 : {
693 0 : tree index = bitsize_int (off * BITS_PER_UNIT);
694 0 : return build3_loc (loc, BIT_FIELD_REF, type, op, TYPE_SIZE (type),
695 0 : index);
696 : }
697 : }
698 : /* ((foo *)&fooarray)[x] => fooarray[x] */
699 0 : else if (TREE_CODE (optype) == ARRAY_TYPE
700 0 : && tree_fits_uhwi_p (TYPE_SIZE_UNIT (TREE_TYPE (optype)))
701 0 : && !integer_zerop (TYPE_SIZE_UNIT (TREE_TYPE (optype))))
702 : {
703 0 : tree type_domain = TYPE_DOMAIN (optype);
704 0 : tree min_val = size_zero_node;
705 0 : if (type_domain && TYPE_MIN_VALUE (type_domain))
706 0 : min_val = TYPE_MIN_VALUE (type_domain);
707 0 : unsigned HOST_WIDE_INT el_sz
708 0 : = tree_to_uhwi (TYPE_SIZE_UNIT (TREE_TYPE (optype)));
709 0 : unsigned HOST_WIDE_INT idx = off / el_sz;
710 0 : unsigned HOST_WIDE_INT rem = off % el_sz;
711 0 : if (tree_fits_uhwi_p (min_val))
712 : {
713 0 : tree index = size_int (idx + tree_to_uhwi (min_val));
714 0 : op = build4_loc (loc, ARRAY_REF, TREE_TYPE (optype), op, index,
715 : NULL_TREE, NULL_TREE);
716 0 : return fold_indirect_ref_1 (ctx, loc, type, op, rem, empty_base,
717 0 : jump_target);
718 : }
719 : }
720 : /* ((foo *)&struct_with_foo_field)[x] => COMPONENT_REF */
721 0 : else if (TREE_CODE (optype) == RECORD_TYPE
722 0 : || TREE_CODE (optype) == UNION_TYPE)
723 : {
724 0 : if (TREE_CODE (optype) == UNION_TYPE)
725 : /* For unions prefer the currently active member. */
726 0 : if (tree field = union_active_member (ctx, op, jump_target))
727 : {
728 0 : unsigned HOST_WIDE_INT el_sz
729 0 : = tree_to_uhwi (TYPE_SIZE_UNIT (TREE_TYPE (field)));
730 0 : if (off < el_sz)
731 : {
732 0 : tree cop = build3 (COMPONENT_REF, TREE_TYPE (field), op, field,
733 : NULL_TREE);
734 0 : if (tree ret = fold_indirect_ref_1 (ctx, loc, type, cop, off,
735 : empty_base, jump_target))
736 : return ret;
737 : }
738 : }
739 0 : for (tree field = TYPE_FIELDS (optype); field; field = DECL_CHAIN (field))
740 0 : if (TREE_CODE (field) == FIELD_DECL
741 0 : && TREE_TYPE (field) != error_mark_node
742 0 : && tree_fits_uhwi_p (TYPE_SIZE_UNIT (TREE_TYPE (field))))
743 : {
744 0 : tree pos = byte_position (field);
745 0 : if (!tree_fits_uhwi_p (pos))
746 0 : continue;
747 0 : unsigned HOST_WIDE_INT upos = tree_to_uhwi (pos);
748 0 : unsigned HOST_WIDE_INT el_sz
749 0 : = tree_to_uhwi (TYPE_SIZE_UNIT (TREE_TYPE (field)));
750 0 : if (upos <= off && off < upos + el_sz)
751 : {
752 0 : tree cop = build3 (COMPONENT_REF, TREE_TYPE (field), op, field,
753 : NULL_TREE);
754 0 : if (tree ret
755 0 : = fold_indirect_ref_1 (ctx, loc, type, cop, off - upos,
756 : empty_base, jump_target))
757 : return ret;
758 : }
759 : }
760 : /* Also handle conversion to an empty base class, which
761 : is represented with a NOP_EXPR. */
762 0 : if (is_empty_class (type) && CLASS_TYPE_P (optype))
763 : {
764 0 : *empty_base = true;
765 0 : return op;
766 : }
767 : }
768 :
769 : return NULL_TREE;
770 : }
771 :
772 : // forked from gcc/cp/constexpr.cc cxx_fold_indirect_ref
773 :
774 : /* A less strict version of fold_indirect_ref_1, which requires cv-quals to
775 : match. We want to be less strict for simple *& folding; if we have a
776 : non-const temporary that we access through a const pointer, that should
777 : work. We handle this here rather than change fold_indirect_ref_1
778 : because we're dealing with things like ADDR_EXPR of INTEGER_CST which
779 : don't really make sense outside of constant expression evaluation. Also
780 : we want to allow folding to COMPONENT_REF, which could cause trouble
781 : with TBAA in fold_indirect_ref_1. */
782 :
783 : static tree
784 4 : rs_fold_indirect_ref (const constexpr_ctx *ctx, location_t loc, tree type,
785 : tree op0, bool *empty_base, tree *jump_target)
786 : {
787 4 : tree sub = op0;
788 4 : tree subtype;
789 :
790 : /* STRIP_NOPS, but stop if REINTERPRET_CAST_P. */
791 8 : while (CONVERT_EXPR_P (sub) || TREE_CODE (sub) == NON_LVALUE_EXPR
792 11 : || TREE_CODE (sub) == VIEW_CONVERT_EXPR)
793 : {
794 3 : if (TREE_CODE (sub) == NOP_EXPR && REINTERPRET_CAST_P (sub))
795 : return NULL_TREE;
796 3 : sub = TREE_OPERAND (sub, 0);
797 : }
798 :
799 4 : subtype = TREE_TYPE (sub);
800 4 : if (!INDIRECT_TYPE_P (subtype))
801 : return NULL_TREE;
802 :
803 : /* Canonicalizes the given OBJ/OFF pair by iteratively absorbing
804 : the innermost component into the offset until it would make the
805 : offset positive, so that cxx_fold_indirect_ref_1 can identify
806 : more folding opportunities. */
807 4 : auto canonicalize_obj_off = [] (tree &obj, tree &off) {
808 0 : while (TREE_CODE (obj) == COMPONENT_REF
809 0 : && (tree_int_cst_sign_bit (off) || integer_zerop (off)))
810 : {
811 0 : tree field = TREE_OPERAND (obj, 1);
812 0 : tree pos = byte_position (field);
813 0 : if (integer_zerop (off) && integer_nonzerop (pos))
814 : /* If the offset is already 0, keep going as long as the
815 : component is at position 0. */
816 : break;
817 0 : off = int_const_binop (PLUS_EXPR, off, pos);
818 0 : obj = TREE_OPERAND (obj, 0);
819 : }
820 0 : };
821 :
822 4 : if (TREE_CODE (sub) == ADDR_EXPR)
823 : {
824 3 : tree op = TREE_OPERAND (sub, 0);
825 3 : tree optype = TREE_TYPE (op);
826 :
827 : /* *&CONST_DECL -> to the value of the const decl. */
828 3 : if (TREE_CODE (op) == CONST_DECL)
829 0 : return DECL_INITIAL (op);
830 : /* *&p => p; make sure to handle *&"str"[cst] here. */
831 3 : if (similar_type_p (optype, type))
832 : {
833 3 : tree fop = fold_read_from_constant_string (op);
834 3 : if (fop)
835 : return fop;
836 : else
837 3 : return op;
838 : }
839 : else
840 : {
841 0 : tree off = integer_zero_node;
842 0 : canonicalize_obj_off (op, off);
843 0 : gcc_assert (integer_zerop (off));
844 0 : return fold_indirect_ref_1 (ctx, loc, type, op, 0, empty_base,
845 : jump_target);
846 : }
847 : }
848 1 : else if (TREE_CODE (sub) == POINTER_PLUS_EXPR
849 1 : && tree_fits_uhwi_p (TREE_OPERAND (sub, 1)))
850 : {
851 0 : tree op00 = TREE_OPERAND (sub, 0);
852 0 : tree off = TREE_OPERAND (sub, 1);
853 :
854 0 : STRIP_NOPS (op00);
855 0 : if (TREE_CODE (op00) == ADDR_EXPR)
856 : {
857 0 : tree obj = TREE_OPERAND (op00, 0);
858 0 : canonicalize_obj_off (obj, off);
859 0 : return fold_indirect_ref_1 (ctx, loc, type, obj, tree_to_uhwi (off),
860 : empty_base, jump_target);
861 : }
862 : }
863 : /* *(foo *)fooarrptr => (*fooarrptr)[0] */
864 1 : else if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
865 1 : && similar_type_p (type, TREE_TYPE (TREE_TYPE (subtype))))
866 : {
867 0 : tree type_domain;
868 0 : tree min_val = size_zero_node;
869 0 : tree newsub = rs_fold_indirect_ref (ctx, loc, TREE_TYPE (subtype), sub,
870 : NULL, jump_target);
871 0 : if (newsub)
872 : sub = newsub;
873 : else
874 0 : sub = build1_loc (loc, INDIRECT_REF, TREE_TYPE (subtype), sub);
875 0 : type_domain = TYPE_DOMAIN (TREE_TYPE (sub));
876 0 : if (type_domain && TYPE_MIN_VALUE (type_domain))
877 0 : min_val = TYPE_MIN_VALUE (type_domain);
878 0 : return build4_loc (loc, ARRAY_REF, type, sub, min_val, NULL_TREE,
879 0 : NULL_TREE);
880 : }
881 :
882 : return NULL_TREE;
883 : }
884 :
885 : // forked from gcc/cp/constexpr.cc cxx_eval_indirect_ref
886 :
887 : static tree
888 3 : rs_eval_indirect_ref (const constexpr_ctx *ctx, tree t, bool lval,
889 : bool *non_constant_p, bool *overflow_p, tree *jump_target)
890 : {
891 3 : tree orig_op0 = TREE_OPERAND (t, 0);
892 3 : bool empty_base = false;
893 :
894 : /* We can handle a MEM_REF like an INDIRECT_REF, if MEM_REF's second
895 : operand is an integer-zero. Otherwise reject the MEM_REF for now. */
896 :
897 3 : if (TREE_CODE (t) == MEM_REF
898 3 : && (!TREE_OPERAND (t, 1) || !integer_zerop (TREE_OPERAND (t, 1))))
899 : {
900 0 : gcc_assert (ctx->quiet);
901 0 : *non_constant_p = true;
902 0 : return t;
903 : }
904 :
905 : /* First try to simplify it directly. */
906 3 : tree r = rs_fold_indirect_ref (ctx, EXPR_LOCATION (t), TREE_TYPE (t),
907 : orig_op0, &empty_base, jump_target);
908 3 : if (!r)
909 : {
910 : /* If that didn't work, evaluate the operand first. */
911 1 : tree op0 = eval_constant_expression (ctx, orig_op0,
912 : /*lval*/ false, non_constant_p,
913 : overflow_p, jump_target);
914 : /* Don't VERIFY_CONSTANT here. */
915 1 : if (*non_constant_p)
916 : return t;
917 :
918 1 : if (!lval && integer_zerop (op0))
919 : {
920 0 : if (!ctx->quiet)
921 0 : error ("dereferencing a null pointer");
922 0 : *non_constant_p = true;
923 0 : return t;
924 : }
925 :
926 1 : r = rs_fold_indirect_ref (ctx, EXPR_LOCATION (t), TREE_TYPE (t), op0,
927 : &empty_base, jump_target);
928 1 : if (r == NULL_TREE)
929 : {
930 : /* We couldn't fold to a constant value. Make sure it's not
931 : something we should have been able to fold. */
932 0 : tree sub = op0;
933 0 : STRIP_NOPS (sub);
934 0 : if (TREE_CODE (sub) == ADDR_EXPR)
935 : {
936 0 : gcc_assert (
937 : !similar_type_p (TREE_TYPE (TREE_TYPE (sub)), TREE_TYPE (t)));
938 : /* DR 1188 says we don't have to deal with this. */
939 0 : if (!ctx->quiet)
940 0 : error_at (rs_expr_loc_or_input_loc (t),
941 : "accessing value of %qE through a %qT glvalue in a "
942 : "constant expression",
943 0 : build_fold_indirect_ref (sub), TREE_TYPE (t));
944 0 : *non_constant_p = true;
945 0 : return t;
946 : }
947 :
948 0 : if (lval && op0 != orig_op0)
949 0 : return build1 (INDIRECT_REF, TREE_TYPE (t), op0);
950 0 : if (!lval)
951 0 : VERIFY_CONSTANT (t);
952 : return t;
953 : }
954 : }
955 :
956 3 : r = eval_constant_expression (ctx, r, lval, non_constant_p, overflow_p,
957 : jump_target);
958 3 : if (*non_constant_p)
959 : return t;
960 :
961 : /* If we're pulling out the value of an empty base, just return an empty
962 : CONSTRUCTOR. */
963 3 : if (empty_base && !lval)
964 : {
965 0 : r = build_constructor (TREE_TYPE (t), NULL);
966 0 : TREE_CONSTANT (r) = true;
967 : }
968 :
969 : return r;
970 : }
971 :
972 : // forked from gcc/cp/constexpr.cc cxx_eval_logical_expression
973 :
974 : /* Subroutine of cxx_eval_constant_expression.
975 : Evaluate a short-circuited logical expression T in the context
976 : of a given constexpr CALL. BAILOUT_VALUE is the value for
977 : early return. CONTINUE_VALUE is used here purely for
978 : sanity check purposes. */
979 :
980 : static tree
981 0 : eval_logical_expression (const constexpr_ctx *ctx, tree t, tree bailout_value,
982 : tree continue_value, bool lval, bool *non_constant_p,
983 : bool *overflow_p, tree *jump_target)
984 : {
985 0 : tree r;
986 0 : tree lhs = eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval,
987 : non_constant_p, overflow_p, jump_target);
988 0 : VERIFY_CONSTANT (lhs);
989 0 : if (tree_int_cst_equal (lhs, bailout_value))
990 : return lhs;
991 0 : gcc_assert (tree_int_cst_equal (lhs, continue_value));
992 0 : r = eval_constant_expression (ctx, TREE_OPERAND (t, 1), lval, non_constant_p,
993 : overflow_p, jump_target);
994 0 : VERIFY_CONSTANT (r);
995 : return r;
996 : }
997 :
998 : // forked from gcc/cp/constexp.rcc lookup_placeholder
999 :
1000 : /* Find the object of TYPE under initialization in CTX. */
1001 :
1002 : static tree
1003 0 : lookup_placeholder (const constexpr_ctx *ctx, bool lval, tree type)
1004 : {
1005 0 : if (!ctx)
1006 : return NULL_TREE;
1007 :
1008 : /* Prefer the outermost matching object, but don't cross
1009 : CONSTRUCTOR_PLACEHOLDER_BOUNDARY constructors. */
1010 0 : if (ctx->ctor && !CONSTRUCTOR_PLACEHOLDER_BOUNDARY (ctx->ctor))
1011 0 : if (tree outer_ob = lookup_placeholder (ctx->parent, lval, type))
1012 : return outer_ob;
1013 :
1014 : /* We could use ctx->object unconditionally, but using ctx->ctor when we
1015 : can is a minor optimization. */
1016 0 : if (!lval && ctx->ctor && same_type_p (TREE_TYPE (ctx->ctor), type))
1017 0 : return ctx->ctor;
1018 :
1019 0 : if (!ctx->object)
1020 : return NULL_TREE;
1021 :
1022 : /* Since an object cannot have a field of its own type, we can search outward
1023 : from ctx->object to find the unique containing object of TYPE. */
1024 : tree ob = ctx->object;
1025 0 : while (ob)
1026 : {
1027 0 : if (same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (ob), type))
1028 : break;
1029 0 : if (handled_component_p (ob))
1030 0 : ob = TREE_OPERAND (ob, 0);
1031 : else
1032 : ob = NULL_TREE;
1033 : }
1034 :
1035 : return ob;
1036 : }
1037 :
1038 : // forked from gcc/cp/constexp.rcc inline_asm_in_constexpr_error
1039 :
1040 : /* Complain about an attempt to evaluate inline assembly. */
1041 :
1042 : static void
1043 0 : inline_asm_in_constexpr_error (location_t loc)
1044 : {
1045 0 : auto_diagnostic_group d;
1046 0 : error_at (loc, "inline assembly is not a constant expression");
1047 0 : inform (loc, "only unevaluated inline assembly is allowed in a "
1048 : "%<constexpr%> function in C++20");
1049 0 : }
1050 :
1051 : // forked from gcc/cp/constexpr.cc verify_ctor_sanity
1052 :
1053 : /* We're about to process an initializer for a class or array TYPE. Make
1054 : sure that CTX is set up appropriately. */
1055 :
1056 : static void
1057 2 : verify_ctor_sanity (const constexpr_ctx *ctx, tree type)
1058 : {
1059 : /* We don't bother building a ctor for an empty base subobject. */
1060 2 : if (is_empty_class (type))
1061 : return;
1062 :
1063 : /* We're in the middle of an initializer that might involve placeholders;
1064 : our caller should have created a CONSTRUCTOR for us to put the
1065 : initializer into. We will either return that constructor or T. */
1066 2 : gcc_assert (ctx->ctor);
1067 2 : gcc_assert (
1068 : same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (ctx->ctor)));
1069 : /* We used to check that ctx->ctor was empty, but that isn't the case when
1070 : the object is zero-initialized before calling the constructor. */
1071 2 : if (ctx->object)
1072 : {
1073 1 : tree otype = TREE_TYPE (ctx->object);
1074 1 : gcc_assert (same_type_ignoring_top_level_qualifiers_p (type, otype)
1075 : /* Handle flexible array members. */
1076 : || (TREE_CODE (otype) == ARRAY_TYPE
1077 : && TYPE_DOMAIN (otype) == NULL_TREE
1078 : && TREE_CODE (type) == ARRAY_TYPE
1079 : && (same_type_ignoring_top_level_qualifiers_p (
1080 : TREE_TYPE (type), TREE_TYPE (otype)))));
1081 : }
1082 2 : gcc_assert (!ctx->object || !DECL_P (ctx->object)
1083 : || *(ctx->global->values.get (ctx->object)) == ctx->ctor);
1084 : }
1085 :
1086 : // forked from gcc/cp/constexpr.cc array_index_cmp
1087 :
1088 : /* Some of the expressions fed to the constexpr mechanism are calls to
1089 : constructors, which have type void. In that case, return the type being
1090 : initialized by the constructor. */
1091 :
1092 : static tree
1093 3 : initialized_type (tree t)
1094 : {
1095 3 : if (TYPE_P (t))
1096 : return t;
1097 3 : tree type = TREE_TYPE (t);
1098 3 : if (TREE_CODE (t) == CALL_EXPR)
1099 : {
1100 : /* A constructor call has void type, so we need to look deeper. */
1101 3 : tree fn = get_function_named_in_call (t);
1102 3 : if (fn && TREE_CODE (fn) == FUNCTION_DECL && DECL_CXX_CONSTRUCTOR_P (fn))
1103 0 : type = DECL_CONTEXT (fn);
1104 : }
1105 0 : else if (TREE_CODE (t) == COMPOUND_EXPR)
1106 0 : return initialized_type (TREE_OPERAND (t, 1));
1107 :
1108 3 : return cv_unqualified (type);
1109 : }
1110 :
1111 : // forked from gcc/cp/constexpr.cc init_subob_ctx
1112 :
1113 : /* We're about to initialize element INDEX of an array or class from VALUE.
1114 : Set up NEW_CTX appropriately by adjusting .object to refer to the
1115 : subobject and creating a new CONSTRUCTOR if the element is itself
1116 : a class or array. */
1117 :
1118 : static void
1119 3 : init_subob_ctx (const constexpr_ctx *ctx, constexpr_ctx &new_ctx, tree index,
1120 : tree &value)
1121 : {
1122 3 : new_ctx = *ctx;
1123 :
1124 3 : if (index && TREE_CODE (index) != INTEGER_CST
1125 2 : && TREE_CODE (index) != FIELD_DECL && TREE_CODE (index) != RANGE_EXPR)
1126 : /* This won't have an element in the new CONSTRUCTOR. */
1127 : return;
1128 :
1129 3 : tree type = initialized_type (value);
1130 3 : if (!AGGREGATE_TYPE_P (type) && !VECTOR_TYPE_P (type))
1131 : /* A non-aggregate member doesn't get its own CONSTRUCTOR. */
1132 : return;
1133 :
1134 : /* The sub-aggregate initializer might contain a placeholder;
1135 : update object to refer to the subobject and ctor to refer to
1136 : the (newly created) sub-initializer. */
1137 1 : if (ctx->object)
1138 : {
1139 1 : if (index == NULL_TREE || TREE_CODE (index) == RANGE_EXPR)
1140 : /* There's no well-defined subobject for this index. */
1141 0 : new_ctx.object = NULL_TREE;
1142 : else
1143 : {
1144 : // Faisal: commenting this out as not sure if it's needed and it's
1145 : // huge new_ctx.object = build_ctor_subob_ref (index, type,
1146 : // ctx->object);
1147 : }
1148 : }
1149 1 : tree elt = build_constructor (type, NULL);
1150 1 : CONSTRUCTOR_NO_CLEARING (elt) = true;
1151 1 : new_ctx.ctor = elt;
1152 :
1153 1 : if (TREE_CODE (value) == TARGET_EXPR)
1154 : /* Avoid creating another CONSTRUCTOR when we expand the TARGET_EXPR. */
1155 0 : value = TARGET_EXPR_INITIAL (value);
1156 : }
1157 :
1158 : // forked from gcc/cp/constexpr.cc base_field_constructor_elt
1159 :
1160 : /* REF is a COMPONENT_REF designating a particular field. V is a vector of
1161 : CONSTRUCTOR elements to initialize (part of) an object containing that
1162 : field. Return a pointer to the constructor_elt corresponding to the
1163 : initialization of the field. */
1164 :
1165 : static constructor_elt *
1166 0 : base_field_constructor_elt (vec<constructor_elt, va_gc> *v, tree ref)
1167 : {
1168 0 : tree aggr = TREE_OPERAND (ref, 0);
1169 0 : tree field = TREE_OPERAND (ref, 1);
1170 0 : HOST_WIDE_INT i;
1171 0 : constructor_elt *ce;
1172 :
1173 0 : gcc_assert (TREE_CODE (ref) == COMPONENT_REF);
1174 :
1175 0 : if (TREE_CODE (aggr) == COMPONENT_REF)
1176 : {
1177 0 : constructor_elt *base_ce = base_field_constructor_elt (v, aggr);
1178 0 : v = CONSTRUCTOR_ELTS (base_ce->value);
1179 : }
1180 :
1181 0 : for (i = 0; vec_safe_iterate (v, i, &ce); ++i)
1182 0 : if (ce->index == field)
1183 0 : return ce;
1184 :
1185 0 : rust_unreachable ();
1186 : return NULL;
1187 : }
1188 :
1189 : /* Return a pointer to the constructor_elt of CTOR which matches INDEX. If no
1190 : matching constructor_elt exists, then add one to CTOR.
1191 :
1192 : As an optimization, if POS_HINT is non-negative then it is used as a guess
1193 : for the (integer) index of the matching constructor_elt within CTOR. */
1194 :
1195 : static constructor_elt *
1196 6 : get_or_insert_ctor_field (tree ctor, tree index, int pos_hint = -1)
1197 : {
1198 : /* Check the hint first. */
1199 1 : if (pos_hint >= 0 && (unsigned) pos_hint < CONSTRUCTOR_NELTS (ctor)
1200 7 : && CONSTRUCTOR_ELT (ctor, pos_hint)->index == index)
1201 : return CONSTRUCTOR_ELT (ctor, pos_hint);
1202 :
1203 5 : tree type = TREE_TYPE (ctor);
1204 5 : if (TREE_CODE (type) == VECTOR_TYPE && index == NULL_TREE)
1205 : {
1206 0 : CONSTRUCTOR_APPEND_ELT (CONSTRUCTOR_ELTS (ctor), index, NULL_TREE);
1207 0 : return &CONSTRUCTOR_ELTS (ctor)->last ();
1208 : }
1209 5 : else if (TREE_CODE (type) == ARRAY_TYPE || TREE_CODE (type) == VECTOR_TYPE)
1210 : {
1211 2 : if (TREE_CODE (index) == RANGE_EXPR)
1212 : {
1213 : /* Support for RANGE_EXPR index lookups is currently limited to
1214 : accessing an existing element via POS_HINT, or appending a new
1215 : element to the end of CTOR. ??? Support for other access
1216 : patterns may also be needed. */
1217 0 : vec<constructor_elt, va_gc> *elts = CONSTRUCTOR_ELTS (ctor);
1218 0 : if (vec_safe_length (elts))
1219 : {
1220 0 : tree lo = TREE_OPERAND (index, 0);
1221 0 : gcc_assert (array_index_cmp (elts->last ().index, lo) < 0);
1222 : }
1223 0 : CONSTRUCTOR_APPEND_ELT (elts, index, NULL_TREE);
1224 0 : return &elts->last ();
1225 : }
1226 :
1227 2 : HOST_WIDE_INT i = find_array_ctor_elt (ctor, index, /*insert*/ true);
1228 2 : gcc_assert (i >= 0);
1229 2 : constructor_elt *cep = CONSTRUCTOR_ELT (ctor, i);
1230 2 : gcc_assert (cep->index == NULL_TREE
1231 : || TREE_CODE (cep->index) != RANGE_EXPR);
1232 : return cep;
1233 : }
1234 : else
1235 : {
1236 3 : gcc_assert (
1237 : TREE_CODE (index) == FIELD_DECL
1238 : && (same_type_ignoring_top_level_qualifiers_p (DECL_CONTEXT (index),
1239 : TREE_TYPE (ctor))));
1240 :
1241 : /* We must keep the CONSTRUCTOR's ELTS in FIELD order.
1242 : Usually we meet initializers in that order, but it is
1243 : possible for base types to be placed not in program
1244 : order. */
1245 3 : tree fields = TYPE_FIELDS (DECL_CONTEXT (index));
1246 3 : unsigned HOST_WIDE_INT idx = 0;
1247 3 : constructor_elt *cep = NULL;
1248 :
1249 : /* Check if we're changing the active member of a union. */
1250 0 : if (TREE_CODE (type) == UNION_TYPE && CONSTRUCTOR_NELTS (ctor)
1251 3 : && CONSTRUCTOR_ELT (ctor, 0)->index != index)
1252 0 : vec_safe_truncate (CONSTRUCTOR_ELTS (ctor), 0);
1253 : /* If the bit offset of INDEX is larger than that of the last
1254 : constructor_elt, then we can just immediately append a new
1255 : constructor_elt to the end of CTOR. */
1256 5 : else if (CONSTRUCTOR_NELTS (ctor)
1257 5 : && tree_int_cst_compare (
1258 2 : bit_position (index),
1259 2 : bit_position (CONSTRUCTOR_ELTS (ctor)->last ().index))
1260 : > 0)
1261 : {
1262 1 : idx = CONSTRUCTOR_NELTS (ctor);
1263 1 : goto insert;
1264 : }
1265 :
1266 : /* Otherwise, we need to iterate over CTOR to find or insert INDEX
1267 : appropriately. */
1268 :
1269 2 : for (; vec_safe_iterate (CONSTRUCTOR_ELTS (ctor), idx, &cep);
1270 0 : idx++, fields = DECL_CHAIN (fields))
1271 : {
1272 1 : if (index == cep->index)
1273 1 : goto found;
1274 :
1275 : /* The field we're initializing must be on the field
1276 : list. Look to see if it is present before the
1277 : field the current ELT initializes. */
1278 0 : for (; fields != cep->index; fields = DECL_CHAIN (fields))
1279 0 : if (index == fields)
1280 0 : goto insert;
1281 : }
1282 : /* We fell off the end of the CONSTRUCTOR, so insert a new
1283 : entry at the end. */
1284 :
1285 2 : insert:
1286 2 : {
1287 2 : constructor_elt ce = {index, NULL_TREE};
1288 :
1289 2 : vec_safe_insert (CONSTRUCTOR_ELTS (ctor), idx, ce);
1290 2 : cep = CONSTRUCTOR_ELT (ctor, idx);
1291 : }
1292 6 : found:;
1293 :
1294 : return cep;
1295 : }
1296 : }
1297 :
1298 : // forked from gcc/cp/constexpr.cc cxx_eval_vector_conditional_expression
1299 :
1300 : /* Subroutine of cxx_eval_constant_expression.
1301 : Attempt to evaluate vector condition expressions. Unlike
1302 : cxx_eval_conditional_expression, VEC_COND_EXPR acts like a normal
1303 : ternary arithmetics operation, where all 3 arguments have to be
1304 : evaluated as constants and then folding computes the result from
1305 : them. */
1306 :
1307 : static tree
1308 0 : eval_vector_conditional_expression (const constexpr_ctx *ctx, tree t,
1309 : bool *non_constant_p, bool *overflow_p,
1310 : tree *jump_target)
1311 : {
1312 0 : tree arg1 = eval_constant_expression (ctx, TREE_OPERAND (t, 0),
1313 : /*lval*/ false, non_constant_p,
1314 : overflow_p, jump_target);
1315 0 : VERIFY_CONSTANT (arg1);
1316 0 : tree arg2 = eval_constant_expression (ctx, TREE_OPERAND (t, 1),
1317 : /*lval*/ false, non_constant_p,
1318 : overflow_p, jump_target);
1319 0 : VERIFY_CONSTANT (arg2);
1320 0 : tree arg3 = eval_constant_expression (ctx, TREE_OPERAND (t, 2),
1321 : /*lval*/ false, non_constant_p,
1322 : overflow_p, jump_target);
1323 0 : VERIFY_CONSTANT (arg3);
1324 0 : location_t loc = EXPR_LOCATION (t);
1325 0 : tree type = TREE_TYPE (t);
1326 0 : tree r = fold_ternary_loc (loc, VEC_COND_EXPR, type, arg1, arg2, arg3);
1327 0 : if (r == NULL_TREE)
1328 : {
1329 0 : if (arg1 == TREE_OPERAND (t, 0) && arg2 == TREE_OPERAND (t, 1)
1330 0 : && arg3 == TREE_OPERAND (t, 2))
1331 : r = t;
1332 : else
1333 0 : r = build3_loc (loc, VEC_COND_EXPR, type, arg1, arg2, arg3);
1334 : }
1335 0 : VERIFY_CONSTANT (r);
1336 : return r;
1337 : }
1338 :
1339 : // forked from gcc/cp/constexpr.cc cxx_eval_bare_aggregate
1340 :
1341 : /* Subroutine of cxx_eval_constant_expression.
1342 : The expression tree T denotes a C-style array or a C-style
1343 : aggregate. Reduce it to a constant expression. */
1344 :
1345 : static tree
1346 2 : eval_bare_aggregate (const constexpr_ctx *ctx, tree t, bool lval,
1347 : bool *non_constant_p, bool *overflow_p, tree *jump_target)
1348 : {
1349 2 : vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (t);
1350 2 : bool changed = false;
1351 2 : gcc_assert (!BRACE_ENCLOSED_INITIALIZER_P (t));
1352 2 : tree type = TREE_TYPE (t);
1353 :
1354 2 : constexpr_ctx new_ctx;
1355 2 : if (TYPE_PTRMEMFUNC_P (type) || VECTOR_TYPE_P (type))
1356 : {
1357 : /* We don't really need the ctx->ctor business for a PMF or
1358 : vector, but it's simpler to use the same code. */
1359 0 : new_ctx = *ctx;
1360 0 : new_ctx.ctor = build_constructor (type, NULL);
1361 0 : new_ctx.object = NULL_TREE;
1362 0 : ctx = &new_ctx;
1363 2 : };
1364 2 : verify_ctor_sanity (ctx, type);
1365 2 : vec<constructor_elt, va_gc> **p = &CONSTRUCTOR_ELTS (ctx->ctor);
1366 4 : vec_alloc (*p, vec_safe_length (v));
1367 :
1368 2 : if (CONSTRUCTOR_PLACEHOLDER_BOUNDARY (t))
1369 0 : CONSTRUCTOR_PLACEHOLDER_BOUNDARY (ctx->ctor) = 1;
1370 :
1371 2 : unsigned i;
1372 2 : tree index, value;
1373 2 : bool constant_p = true;
1374 2 : bool side_effects_p = false;
1375 5 : FOR_EACH_CONSTRUCTOR_ELT (v, i, index, value)
1376 : {
1377 3 : tree orig_value = value;
1378 : /* Like in cxx_eval_store_expression, omit entries for empty fields. */
1379 3 : bool no_slot = TREE_CODE (type) == RECORD_TYPE && is_empty_field (index);
1380 3 : if (no_slot)
1381 0 : new_ctx = *ctx;
1382 : else
1383 3 : init_subob_ctx (ctx, new_ctx, index, value);
1384 3 : int pos_hint = -1;
1385 3 : if (new_ctx.ctor != ctx->ctor)
1386 : {
1387 : /* If we built a new CONSTRUCTOR, attach it now so that other
1388 : initializers can refer to it. */
1389 1 : constructor_elt *cep = get_or_insert_ctor_field (ctx->ctor, index);
1390 1 : cep->value = new_ctx.ctor;
1391 1 : pos_hint = cep - (*p)->begin ();
1392 : }
1393 2 : else if (TREE_CODE (type) == UNION_TYPE)
1394 : /* Otherwise if we're constructing a non-aggregate union member, set
1395 : the active union member now so that we can later detect and diagnose
1396 : if its initializer attempts to activate another member. */
1397 0 : get_or_insert_ctor_field (ctx->ctor, index);
1398 3 : tree elt
1399 3 : = eval_constant_expression (&new_ctx, value, lval, non_constant_p,
1400 : overflow_p, jump_target);
1401 : /* Don't VERIFY_CONSTANT here. */
1402 3 : if (ctx->quiet && *non_constant_p)
1403 : break;
1404 3 : if (elt != orig_value)
1405 3 : changed = true;
1406 :
1407 3 : if (!TREE_CONSTANT (elt))
1408 0 : constant_p = false;
1409 3 : if (TREE_SIDE_EFFECTS (elt))
1410 0 : side_effects_p = true;
1411 3 : if (index && TREE_CODE (index) == COMPONENT_REF)
1412 : {
1413 : /* This is an initialization of a vfield inside a base
1414 : subaggregate that we already initialized; push this
1415 : initialization into the previous initialization. */
1416 0 : constructor_elt *inner = base_field_constructor_elt (*p, index);
1417 0 : inner->value = elt;
1418 0 : changed = true;
1419 0 : }
1420 3 : else if (index
1421 3 : && (TREE_CODE (index) == NOP_EXPR
1422 3 : || TREE_CODE (index) == POINTER_PLUS_EXPR))
1423 : {
1424 : /* This is an initializer for an empty base; now that we've
1425 : checked that it's constant, we can ignore it. */
1426 0 : gcc_assert (is_empty_class (TREE_TYPE (TREE_TYPE (index))));
1427 : changed = true;
1428 : }
1429 3 : else if (no_slot)
1430 : changed = true;
1431 : else
1432 : {
1433 3 : if (TREE_CODE (type) == UNION_TYPE && (*p)->last ().index != index)
1434 : /* The initializer erroneously changed the active union member that
1435 : we're initializing. */
1436 0 : gcc_assert (*non_constant_p);
1437 : else
1438 : {
1439 : /* The initializer might have mutated the underlying CONSTRUCTOR,
1440 : so recompute the location of the target constructer_elt. */
1441 3 : constructor_elt *cep
1442 3 : = get_or_insert_ctor_field (ctx->ctor, index, pos_hint);
1443 3 : cep->value = elt;
1444 : }
1445 :
1446 : /* Adding or replacing an element might change the ctor's flags. */
1447 3 : TREE_CONSTANT (ctx->ctor) = constant_p;
1448 3 : TREE_SIDE_EFFECTS (ctx->ctor) = side_effects_p;
1449 : }
1450 : }
1451 2 : if (*non_constant_p || !changed)
1452 : return t;
1453 2 : t = ctx->ctor;
1454 : /* We're done building this CONSTRUCTOR, so now we can interpret an
1455 : element without an explicit initializer as value-initialized. */
1456 2 : CONSTRUCTOR_NO_CLEARING (t) = false;
1457 2 : TREE_CONSTANT (t) = constant_p;
1458 2 : TREE_SIDE_EFFECTS (t) = side_effects_p;
1459 2 : if (VECTOR_TYPE_P (type))
1460 0 : t = fold (t);
1461 : return t;
1462 : }
1463 :
1464 : /* Subroutine of cxx_eval_constant_expression.
1465 : Like cxx_eval_unary_expression, except for trinary expressions. */
1466 :
1467 : static tree
1468 0 : cxx_eval_trinary_expression (const constexpr_ctx *ctx, tree t, bool lval,
1469 : bool *non_constant_p, bool *overflow_p,
1470 : tree *jump_target)
1471 : {
1472 0 : int i;
1473 0 : tree args[3];
1474 0 : tree val;
1475 :
1476 0 : for (i = 0; i < 3; i++)
1477 : {
1478 0 : args[i]
1479 0 : = eval_constant_expression (ctx, TREE_OPERAND (t, i), lval,
1480 : non_constant_p, overflow_p, jump_target);
1481 0 : VERIFY_CONSTANT (args[i]);
1482 : }
1483 :
1484 0 : val = fold_ternary_loc (EXPR_LOCATION (t), TREE_CODE (t), TREE_TYPE (t),
1485 : args[0], args[1], args[2]);
1486 0 : if (val == NULL_TREE)
1487 : return t;
1488 0 : VERIFY_CONSTANT (val);
1489 : return val;
1490 : }
1491 :
1492 : /* Return true if T is a valid constant initializer. If a CONSTRUCTOR
1493 : initializes all the members, the CONSTRUCTOR_NO_CLEARING flag will be
1494 : cleared.
1495 : FIXME speed this up, it's taking 16% of compile time on sieve testcase. */
1496 :
1497 : bool
1498 263045 : reduced_constant_expression_p (tree t)
1499 : {
1500 263045 : if (t == NULL_TREE)
1501 : return false;
1502 :
1503 263045 : switch (TREE_CODE (t))
1504 : {
1505 : case PTRMEM_CST:
1506 : /* Even if we can't lower this yet, it's constant. */
1507 : return true;
1508 :
1509 78 : case CONSTRUCTOR:
1510 : /* And we need to handle PTRMEM_CST wrapped in a CONSTRUCTOR. */
1511 78 : tree field;
1512 78 : if (CONSTRUCTOR_NO_CLEARING (t))
1513 : {
1514 0 : if (TREE_CODE (TREE_TYPE (t)) == VECTOR_TYPE)
1515 : /* An initialized vector would have a VECTOR_CST. */
1516 : return false;
1517 0 : else if (TREE_CODE (TREE_TYPE (t)) == ARRAY_TYPE)
1518 : {
1519 : /* There must be a valid constant initializer at every array
1520 : index. */
1521 0 : tree min = TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (t)));
1522 0 : tree max = TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (t)));
1523 0 : tree cursor = min;
1524 0 : for (auto &e : CONSTRUCTOR_ELTS (t))
1525 : {
1526 0 : if (!reduced_constant_expression_p (e.value))
1527 : return false;
1528 0 : if (array_index_cmp (cursor, e.index) != 0)
1529 : return false;
1530 0 : if (TREE_CODE (e.index) == RANGE_EXPR)
1531 0 : cursor = TREE_OPERAND (e.index, 1);
1532 0 : cursor = int_const_binop (PLUS_EXPR, cursor, size_one_node);
1533 : }
1534 0 : if (find_array_ctor_elt (t, max) == -1)
1535 : return false;
1536 0 : goto ok;
1537 : }
1538 0 : else if (TREE_CODE (TREE_TYPE (t)) == UNION_TYPE)
1539 : {
1540 0 : if (CONSTRUCTOR_NELTS (t) == 0)
1541 : /* An initialized union has a constructor element. */
1542 : return false;
1543 : /* And it only initializes one member. */
1544 : field = NULL_TREE;
1545 : }
1546 : else
1547 0 : field = next_initializable_field (TYPE_FIELDS (TREE_TYPE (t)));
1548 : }
1549 : else
1550 : field = NULL_TREE;
1551 627 : for (auto &e : CONSTRUCTOR_ELTS (t))
1552 : {
1553 : /* If VAL is null, we're in the middle of initializing this
1554 : element. */
1555 419 : if (!reduced_constant_expression_p (e.value))
1556 : return false;
1557 : /* Empty class field may or may not have an initializer. */
1558 419 : for (; field && e.index != field;
1559 0 : field = next_initializable_field (DECL_CHAIN (field)))
1560 0 : if (!is_really_empty_class (TREE_TYPE (field),
1561 : /*ignore_vptr*/ false))
1562 : return false;
1563 419 : if (field)
1564 0 : field = next_initializable_field (DECL_CHAIN (field));
1565 : }
1566 : /* There could be a non-empty field at the end. */
1567 78 : for (; field; field = next_initializable_field (DECL_CHAIN (field)))
1568 0 : if (!is_really_empty_class (TREE_TYPE (field), /*ignore_vptr*/ false))
1569 : return false;
1570 78 : ok:
1571 78 : if (CONSTRUCTOR_NO_CLEARING (t))
1572 : /* All the fields are initialized. */
1573 0 : CONSTRUCTOR_NO_CLEARING (t) = false;
1574 : return true;
1575 :
1576 262967 : default:
1577 : /* FIXME are we calling this too much? */
1578 262967 : return initializer_constant_valid_p (t, TREE_TYPE (t)) != NULL_TREE;
1579 : }
1580 : }
1581 :
1582 : /* TEMP is the constant value of a temporary object of type TYPE. Adjust
1583 : the type of the value to match. */
1584 :
1585 : static tree
1586 14 : adjust_temp_type (tree type, tree temp)
1587 : {
1588 14 : if (same_type_p (TREE_TYPE (temp), type))
1589 : return temp;
1590 :
1591 12 : if (TREE_CODE (temp) == CONSTRUCTOR)
1592 : {
1593 1 : tree t = copy_node (temp);
1594 1 : TREE_TYPE (t) = type;
1595 1 : return t;
1596 : }
1597 :
1598 11 : gcc_assert (scalarish_type_p (type));
1599 : /* Now we know we're dealing with a scalar, and a prvalue of non-class
1600 : type is cv-unqualified. */
1601 11 : return fold_convert (cv_unqualified (type), temp);
1602 : }
1603 :
1604 : // forked from gcc/cp/constexpr.cc free_constructor
1605 :
1606 : /* If T is a CONSTRUCTOR, ggc_free T and any sub-CONSTRUCTORs. */
1607 :
1608 : static void
1609 0 : free_constructor (tree t)
1610 : {
1611 0 : if (!t || TREE_CODE (t) != CONSTRUCTOR)
1612 0 : return;
1613 0 : releasing_vec ctors;
1614 0 : vec_safe_push (ctors, t);
1615 0 : while (!ctors->is_empty ())
1616 : {
1617 0 : tree c = ctors->pop ();
1618 0 : if (vec<constructor_elt, va_gc> *elts = CONSTRUCTOR_ELTS (c))
1619 : {
1620 : constructor_elt *ce;
1621 0 : for (HOST_WIDE_INT i = 0; vec_safe_iterate (elts, i, &ce); ++i)
1622 0 : if (TREE_CODE (ce->value) == CONSTRUCTOR)
1623 0 : vec_safe_push (ctors, ce->value);
1624 0 : ggc_free (elts);
1625 : }
1626 0 : ggc_free (c);
1627 : }
1628 0 : }
1629 :
1630 : static tree eval_and_check_array_index (const constexpr_ctx *ctx, tree t,
1631 : bool allow_one_past,
1632 : bool *non_constant_p, bool *overflow_p,
1633 : tree *jump_target);
1634 :
1635 : // forked from gcc/cp/constexpr.cc cxx_eval_array_reference
1636 :
1637 : /* Subroutine of cxx_eval_constant_expression.
1638 : Attempt to reduce a reference to an array slot. */
1639 :
1640 : static tree
1641 9 : eval_array_reference (const constexpr_ctx *ctx, tree t, bool lval,
1642 : bool *non_constant_p, bool *overflow_p, tree *jump_target)
1643 : {
1644 9 : tree oldary = TREE_OPERAND (t, 0);
1645 9 : tree ary = eval_constant_expression (ctx, oldary, lval, non_constant_p,
1646 : overflow_p, jump_target);
1647 9 : if (*non_constant_p)
1648 : return t;
1649 9 : if (!lval && TREE_CODE (ary) == VIEW_CONVERT_EXPR
1650 0 : && VECTOR_TYPE_P (TREE_TYPE (TREE_OPERAND (ary, 0)))
1651 9 : && TREE_TYPE (t) == TREE_TYPE (TREE_TYPE (TREE_OPERAND (ary, 0))))
1652 0 : ary = TREE_OPERAND (ary, 0);
1653 :
1654 9 : tree oldidx = TREE_OPERAND (t, 1);
1655 9 : tree index = eval_and_check_array_index (ctx, t, lval, non_constant_p,
1656 : overflow_p, jump_target);
1657 9 : if (*non_constant_p)
1658 : return t;
1659 :
1660 8 : if (lval && ary == oldary && index == oldidx)
1661 : return t;
1662 8 : else if (lval)
1663 0 : return build4 (ARRAY_REF, TREE_TYPE (t), ary, index, NULL, NULL);
1664 :
1665 8 : unsigned len = 0, elem_nchars = 1;
1666 8 : tree elem_type = TREE_TYPE (TREE_TYPE (ary));
1667 8 : if (TREE_CODE (ary) == CONSTRUCTOR)
1668 8 : len = CONSTRUCTOR_NELTS (ary);
1669 0 : else if (TREE_CODE (ary) == STRING_CST)
1670 : {
1671 0 : elem_nchars
1672 0 : = (TYPE_PRECISION (elem_type) / TYPE_PRECISION (char_type_node));
1673 0 : len = (unsigned) TREE_STRING_LENGTH (ary) / elem_nchars;
1674 : }
1675 0 : else if (TREE_CODE (ary) == VECTOR_CST)
1676 : /* We don't create variable-length VECTOR_CSTs. */
1677 0 : len = VECTOR_CST_NELTS (ary).to_constant ();
1678 : else
1679 : {
1680 : /* We can't do anything with other tree codes, so use
1681 : VERIFY_CONSTANT to complain and fail. */
1682 0 : VERIFY_CONSTANT (ary);
1683 0 : rust_unreachable ();
1684 : }
1685 :
1686 8 : bool found;
1687 8 : HOST_WIDE_INT i = 0;
1688 8 : if (TREE_CODE (ary) == CONSTRUCTOR)
1689 : {
1690 8 : HOST_WIDE_INT ix = find_array_ctor_elt (ary, index);
1691 8 : found = (ix >= 0);
1692 8 : if (found)
1693 8 : i = ix;
1694 : }
1695 : else
1696 : {
1697 0 : i = tree_to_shwi (index);
1698 0 : found = (i < len);
1699 : }
1700 :
1701 8 : if (found)
1702 : {
1703 8 : tree r;
1704 8 : if (TREE_CODE (ary) == CONSTRUCTOR)
1705 8 : r = (*CONSTRUCTOR_ELTS (ary))[i].value;
1706 0 : else if (TREE_CODE (ary) == VECTOR_CST)
1707 0 : r = VECTOR_CST_ELT (ary, i);
1708 : else
1709 0 : r = extract_string_elt (ary, elem_nchars, i);
1710 :
1711 8 : if (r)
1712 : /* Don't VERIFY_CONSTANT here. */
1713 : return r;
1714 :
1715 : /* Otherwise the element doesn't have a value yet. */
1716 : }
1717 :
1718 : /* Not found. */
1719 :
1720 0 : if (TREE_CODE (ary) == CONSTRUCTOR && CONSTRUCTOR_NO_CLEARING (ary))
1721 : {
1722 : /* 'ary' is part of the aggregate initializer we're currently
1723 : building; if there's no initializer for this element yet,
1724 : that's an error. */
1725 0 : if (!ctx->quiet)
1726 0 : error ("accessing uninitialized array element");
1727 0 : *non_constant_p = true;
1728 0 : return t;
1729 : }
1730 :
1731 : /* If it's within the array bounds but doesn't have an explicit
1732 : initializer, it's initialized from {}. But use build_value_init
1733 : directly for non-aggregates to avoid creating a garbage CONSTRUCTOR. */
1734 0 : tree val = NULL_TREE;
1735 0 : sorry ("array size expression is not supported yet");
1736 :
1737 0 : constexpr_ctx new_ctx;
1738 0 : if (is_really_empty_class (elem_type, /*ignore_vptr*/ false))
1739 0 : return build_constructor (elem_type, NULL);
1740 : // else if (CP_AGGREGATE_TYPE_P (elem_type))
1741 : // {
1742 : // tree empty_ctor = build_constructor (init_list_type_node, NULL);
1743 : // //val = digest_init (elem_type, empty_ctor, tf_warning_or_error);
1744 : // }
1745 : // else
1746 : // val = build_value_init (elem_type, tf_warning_or_error);
1747 :
1748 0 : if (!SCALAR_TYPE_P (elem_type))
1749 : {
1750 0 : new_ctx = *ctx;
1751 0 : if (ctx->object)
1752 : /* If there was no object, don't add one: it could confuse us
1753 : into thinking we're modifying a const object. */
1754 0 : new_ctx.object = t;
1755 0 : new_ctx.ctor = build_constructor (elem_type, NULL);
1756 0 : ctx = &new_ctx;
1757 : }
1758 0 : t = eval_constant_expression (ctx, val, lval, non_constant_p, overflow_p,
1759 : jump_target);
1760 0 : if (!SCALAR_TYPE_P (elem_type) && t != ctx->ctor)
1761 0 : free_constructor (ctx->ctor);
1762 : return t;
1763 : }
1764 :
1765 : // forked from gcc/cp/constexpr.cc cxx_eval_component_reference
1766 :
1767 : /* Subroutine of cxx_eval_constant_expression.
1768 : Attempt to reduce a field access of a value of class type. */
1769 :
1770 : static tree
1771 11 : eval_component_reference (const constexpr_ctx *ctx, tree t, bool lval,
1772 : bool *non_constant_p, bool *overflow_p,
1773 : tree *jump_target)
1774 : {
1775 11 : unsigned HOST_WIDE_INT i;
1776 11 : tree field;
1777 11 : tree value;
1778 11 : tree part = TREE_OPERAND (t, 1);
1779 11 : tree orig_whole = TREE_OPERAND (t, 0);
1780 11 : tree whole = eval_constant_expression (ctx, orig_whole, lval, non_constant_p,
1781 : overflow_p, jump_target);
1782 11 : if (INDIRECT_REF_P (whole) && integer_zerop (TREE_OPERAND (whole, 0)))
1783 : {
1784 0 : if (!ctx->quiet)
1785 0 : error ("dereferencing a null pointer in %qE", orig_whole);
1786 0 : *non_constant_p = true;
1787 0 : return t;
1788 : }
1789 :
1790 11 : if (whole == orig_whole)
1791 : return t;
1792 11 : if (lval)
1793 0 : return fold_build3 (COMPONENT_REF, TREE_TYPE (t), whole, part, NULL_TREE);
1794 : /* Don't VERIFY_CONSTANT here; we only want to check that we got a
1795 : CONSTRUCTOR. */
1796 11 : if (!*non_constant_p && TREE_CODE (whole) != CONSTRUCTOR)
1797 : {
1798 0 : if (!ctx->quiet)
1799 0 : error ("%qE is not a constant expression", orig_whole);
1800 0 : *non_constant_p = true;
1801 : }
1802 11 : if (DECL_MUTABLE_P (part))
1803 : {
1804 0 : if (!ctx->quiet)
1805 0 : error ("mutable %qD is not usable in a constant expression", part);
1806 0 : *non_constant_p = true;
1807 : }
1808 11 : if (*non_constant_p)
1809 : return t;
1810 11 : bool pmf = TYPE_PTRMEMFUNC_P (TREE_TYPE (whole));
1811 12 : FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (whole), i, field, value)
1812 : {
1813 : /* Use name match for PMF fields, as a variant will have a
1814 : different FIELD_DECL with a different type. */
1815 12 : if (pmf ? DECL_NAME (field) == DECL_NAME (part) : field == part)
1816 : {
1817 11 : if (value)
1818 : {
1819 11 : STRIP_ANY_LOCATION_WRAPPER (value);
1820 11 : return value;
1821 : }
1822 : else
1823 : /* We're in the middle of initializing it. */
1824 : break;
1825 : }
1826 : }
1827 0 : if (TREE_CODE (TREE_TYPE (whole)) == UNION_TYPE
1828 0 : && CONSTRUCTOR_NELTS (whole) > 0)
1829 : {
1830 : /* DR 1188 says we don't have to deal with this. */
1831 0 : if (!ctx->quiet)
1832 : {
1833 0 : constructor_elt *cep = CONSTRUCTOR_ELT (whole, 0);
1834 0 : if (cep->value == NULL_TREE)
1835 0 : error ("accessing uninitialized member %qD", part);
1836 : else
1837 0 : error ("accessing %qD member instead of initialized %qD member in "
1838 : "constant expression",
1839 : part, cep->index);
1840 : }
1841 0 : *non_constant_p = true;
1842 0 : return t;
1843 : }
1844 :
1845 : /* We only create a CONSTRUCTOR for a subobject when we modify it, so empty
1846 : classes never get represented; throw together a value now. */
1847 0 : if (is_really_empty_class (TREE_TYPE (t), /*ignore_vptr*/ false))
1848 0 : return build_constructor (TREE_TYPE (t), NULL);
1849 :
1850 0 : gcc_assert (DECL_CONTEXT (part) == TYPE_MAIN_VARIANT (TREE_TYPE (whole)));
1851 :
1852 0 : if (CONSTRUCTOR_NO_CLEARING (whole))
1853 : {
1854 : /* 'whole' is part of the aggregate initializer we're currently
1855 : building; if there's no initializer for this member yet, that's an
1856 : error. */
1857 0 : if (!ctx->quiet)
1858 0 : error ("accessing uninitialized member %qD", part);
1859 0 : *non_constant_p = true;
1860 0 : return t;
1861 : }
1862 :
1863 0 : value = NULL_TREE;
1864 0 : sorry ("constant folding not supported for this tree code");
1865 : /* If there's no explicit init for this field, it's value-initialized. */
1866 : // Faisal: commenting this out as not sure if we need this but we need to come
1867 : // back to handle this to assign suitable value to value before sending it in
1868 : // eval_constant_expression below
1869 : // value = build_value_init (TREE_TYPE (t), tf_warning_or_error);
1870 0 : return eval_constant_expression (ctx, value, lval, non_constant_p, overflow_p,
1871 0 : jump_target);
1872 : }
1873 :
1874 : /* Subroutine of cxx_eval_statement_list. Determine whether the statement
1875 : STMT matches *jump_target. If we're looking for a case label and we see
1876 : the default label, note it in ctx->css_state. */
1877 :
1878 : static bool
1879 2 : label_matches (const constexpr_ctx *ctx, tree *jump_target, tree stmt)
1880 : {
1881 2 : switch (TREE_CODE (*jump_target))
1882 : {
1883 2 : case LABEL_DECL:
1884 2 : if (TREE_CODE (stmt) == LABEL_EXPR
1885 2 : && LABEL_EXPR_LABEL (stmt) == *jump_target)
1886 2 : return true;
1887 : break;
1888 :
1889 0 : case INTEGER_CST:
1890 0 : if (TREE_CODE (stmt) == CASE_LABEL_EXPR)
1891 : {
1892 0 : gcc_assert (ctx->css_state != NULL);
1893 0 : if (!CASE_LOW (stmt))
1894 : {
1895 : /* default: should appear just once in a SWITCH_EXPR
1896 : body (excluding nested SWITCH_EXPR). */
1897 0 : gcc_assert (*ctx->css_state != css_default_seen);
1898 : /* When evaluating SWITCH_EXPR body for the second time,
1899 : return true for the default: label. */
1900 0 : if (*ctx->css_state == css_default_processing)
1901 : return true;
1902 0 : *ctx->css_state = css_default_seen;
1903 : }
1904 0 : else if (CASE_HIGH (stmt))
1905 : {
1906 0 : if (tree_int_cst_le (CASE_LOW (stmt), *jump_target)
1907 0 : && tree_int_cst_le (*jump_target, CASE_HIGH (stmt)))
1908 : return true;
1909 : }
1910 0 : else if (tree_int_cst_equal (*jump_target, CASE_LOW (stmt)))
1911 : return true;
1912 : }
1913 : break;
1914 :
1915 : case BREAK_STMT:
1916 : case CONTINUE_STMT:
1917 : /* These two are handled directly in cxx_eval_loop_expr by testing
1918 : breaks (jump_target) or continues (jump_target). */
1919 : break;
1920 :
1921 0 : default:
1922 0 : rust_unreachable ();
1923 : }
1924 : return false;
1925 : }
1926 :
1927 : static tree
1928 1858390 : eval_constant_expression (const constexpr_ctx *ctx, tree t, bool lval,
1929 : bool *non_constant_p, bool *overflow_p,
1930 : tree *jump_target)
1931 : {
1932 1858390 : if (t == NULL_TREE)
1933 : return NULL_TREE;
1934 :
1935 1596243 : if (jump_target && *jump_target)
1936 : {
1937 : /* If we are jumping, ignore all statements/expressions except those
1938 : that could have LABEL_EXPR or CASE_LABEL_EXPR in their bodies. */
1939 7 : switch (TREE_CODE (t))
1940 : {
1941 : case BIND_EXPR:
1942 : case STATEMENT_LIST:
1943 : case LOOP_EXPR:
1944 : case COND_EXPR:
1945 : case IF_STMT:
1946 : case DO_STMT:
1947 : case WHILE_STMT:
1948 : case FOR_STMT:
1949 : break;
1950 2 : case LABEL_EXPR:
1951 2 : case CASE_LABEL_EXPR:
1952 2 : if (label_matches (ctx, jump_target, t))
1953 : /* Found it. */
1954 2 : *jump_target = NULL_TREE;
1955 : return NULL_TREE;
1956 : default:
1957 : return NULL_TREE;
1958 : }
1959 : }
1960 1596239 : if (error_operand_p (t))
1961 : {
1962 4 : *non_constant_p = true;
1963 4 : return t;
1964 : }
1965 :
1966 1596235 : location_t loc = EXPR_LOCATION (t);
1967 :
1968 1596235 : if (CONSTANT_CLASS_P (t))
1969 : {
1970 266427 : if (TREE_OVERFLOW (t))
1971 : {
1972 0 : error_at (loc, "overflow in constant expression");
1973 0 : return t;
1974 : }
1975 :
1976 : return t;
1977 : }
1978 :
1979 : // Avoid excessively long constexpr evaluations
1980 1329808 : if (++ctx->global->constexpr_ops_count >= constexpr_ops_limit)
1981 : {
1982 0 : rust_error_at (
1983 : loc,
1984 : "%<constexpr%> evaluation operation count exceeds limit of "
1985 : "%wd (use %<-fconstexpr-ops-limit=%> to increase the limit)",
1986 : constexpr_ops_limit);
1987 :
1988 0 : return t;
1989 : }
1990 :
1991 1329808 : constexpr_ctx new_ctx;
1992 1329808 : tree r = t;
1993 1329808 : tree_code tcode = TREE_CODE (t);
1994 1329808 : switch (tcode)
1995 : {
1996 263 : case VAR_DECL:
1997 263 : if (DECL_HAS_VALUE_EXPR_P (t))
1998 : {
1999 0 : r = DECL_VALUE_EXPR (t);
2000 0 : return eval_constant_expression (ctx, r, lval, non_constant_p,
2001 0 : overflow_p, jump_target);
2002 : }
2003 : /* fall through */
2004 1725 : case CONST_DECL:
2005 : /* We used to not check lval for CONST_DECL, but darwin.cc uses
2006 : CONST_DECL for aggregate constants. */
2007 1725 : if (lval)
2008 : return t;
2009 1613 : else if (t == ctx->object)
2010 0 : return ctx->ctor;
2011 1613 : if (VAR_P (t))
2012 : {
2013 151 : if (tree v = ctx->global->get_value (t))
2014 : {
2015 149 : r = v;
2016 149 : break;
2017 : }
2018 : }
2019 1464 : if (COMPLETE_TYPE_P (TREE_TYPE (t))
2020 1464 : && is_really_empty_class (TREE_TYPE (t), /*ignore_vptr*/ false))
2021 : {
2022 : /* If the class is empty, we aren't actually loading anything. */
2023 0 : r = build_constructor (TREE_TYPE (t), NULL);
2024 0 : TREE_CONSTANT (r) = true;
2025 : }
2026 1464 : else if (ctx->strict)
2027 1464 : r = decl_really_constant_value (t, /*unshare_p=*/false);
2028 : else
2029 0 : r = decl_constant_value (t, /*unshare_p=*/false);
2030 1464 : if (TREE_CODE (r) == TARGET_EXPR
2031 1464 : && TREE_CODE (TARGET_EXPR_INITIAL (r)) == CONSTRUCTOR)
2032 0 : r = TARGET_EXPR_INITIAL (r);
2033 1464 : if (DECL_P (r) && !(VAR_P (t) && TYPE_REF_P (TREE_TYPE (t))))
2034 : {
2035 2 : if (!ctx->quiet)
2036 2 : non_const_var_error (loc, r);
2037 2 : *non_constant_p = true;
2038 : }
2039 : break;
2040 :
2041 59 : case PARM_DECL:
2042 59 : if (lval && !TYPE_REF_P (TREE_TYPE (t)))
2043 : /* glvalue use. */;
2044 48 : else if (tree *p = ctx->global->values.get (r))
2045 48 : r = *p;
2046 0 : else if (lval)
2047 : /* Defer in case this is only used for its type. */;
2048 0 : else if (COMPLETE_TYPE_P (TREE_TYPE (t))
2049 0 : && is_really_empty_class (TREE_TYPE (t), /*ignore_vptr*/ false))
2050 : {
2051 : /* If the class is empty, we aren't actually loading anything. */
2052 0 : r = build_constructor (TREE_TYPE (t), NULL);
2053 0 : TREE_CONSTANT (r) = true;
2054 : }
2055 : else
2056 : {
2057 0 : if (!ctx->quiet)
2058 0 : error ("%qE is not a constant expression", t);
2059 0 : *non_constant_p = true;
2060 : }
2061 : break;
2062 :
2063 349 : case POINTER_PLUS_EXPR:
2064 349 : case POINTER_DIFF_EXPR:
2065 349 : case PLUS_EXPR:
2066 349 : case MINUS_EXPR:
2067 349 : case MULT_EXPR:
2068 349 : case TRUNC_DIV_EXPR:
2069 349 : case CEIL_DIV_EXPR:
2070 349 : case FLOOR_DIV_EXPR:
2071 349 : case ROUND_DIV_EXPR:
2072 349 : case TRUNC_MOD_EXPR:
2073 349 : case CEIL_MOD_EXPR:
2074 349 : case ROUND_MOD_EXPR:
2075 349 : case RDIV_EXPR:
2076 349 : case EXACT_DIV_EXPR:
2077 349 : case MIN_EXPR:
2078 349 : case MAX_EXPR:
2079 349 : case LSHIFT_EXPR:
2080 349 : case RSHIFT_EXPR:
2081 349 : case LROTATE_EXPR:
2082 349 : case RROTATE_EXPR:
2083 349 : case BIT_IOR_EXPR:
2084 349 : case BIT_XOR_EXPR:
2085 349 : case BIT_AND_EXPR:
2086 349 : case TRUTH_XOR_EXPR:
2087 349 : case LT_EXPR:
2088 349 : case LE_EXPR:
2089 349 : case GT_EXPR:
2090 349 : case GE_EXPR:
2091 349 : case EQ_EXPR:
2092 349 : case NE_EXPR:
2093 349 : case SPACESHIP_EXPR:
2094 349 : case UNORDERED_EXPR:
2095 349 : case ORDERED_EXPR:
2096 349 : case UNLT_EXPR:
2097 349 : case UNLE_EXPR:
2098 349 : case UNGT_EXPR:
2099 349 : case UNGE_EXPR:
2100 349 : case UNEQ_EXPR:
2101 349 : case LTGT_EXPR:
2102 349 : case RANGE_EXPR:
2103 349 : case COMPLEX_EXPR:
2104 349 : r = eval_binary_expression (ctx, t, lval, non_constant_p, overflow_p,
2105 : jump_target);
2106 349 : break;
2107 :
2108 : /* fold can introduce non-IF versions of these; still treat them as
2109 : short-circuiting. */
2110 0 : case TRUTH_AND_EXPR:
2111 0 : case TRUTH_ANDIF_EXPR:
2112 0 : r = eval_logical_expression (ctx, t, boolean_false_node,
2113 : boolean_true_node, lval, non_constant_p,
2114 : overflow_p, jump_target);
2115 0 : break;
2116 :
2117 0 : case TRUTH_OR_EXPR:
2118 0 : case TRUTH_ORIF_EXPR:
2119 0 : r = eval_logical_expression (ctx, t, boolean_true_node,
2120 : boolean_false_node, lval, non_constant_p,
2121 : overflow_p, jump_target);
2122 0 : break;
2123 :
2124 0 : case TARGET_EXPR:
2125 0 : {
2126 0 : tree type = TREE_TYPE (t);
2127 :
2128 0 : if (!literal_type_p (type))
2129 : {
2130 0 : if (!ctx->quiet)
2131 : {
2132 0 : auto_diagnostic_group d;
2133 0 : error ("temporary of non-literal type %qT in a "
2134 : "constant expression",
2135 : type);
2136 0 : explain_non_literal_class (type);
2137 0 : }
2138 0 : *non_constant_p = true;
2139 0 : break;
2140 : }
2141 0 : gcc_checking_assert (!TARGET_EXPR_DIRECT_INIT_P (t));
2142 : /* Avoid evaluating a TARGET_EXPR more than once. */
2143 0 : tree slot = TARGET_EXPR_SLOT (t);
2144 0 : if (tree *p = ctx->global->values.get (slot))
2145 : {
2146 0 : if (lval)
2147 0 : return slot;
2148 0 : r = *p;
2149 0 : break;
2150 : }
2151 0 : if ((AGGREGATE_TYPE_P (type) || VECTOR_TYPE_P (type)))
2152 : {
2153 : /* We're being expanded without an explicit target, so start
2154 : initializing a new object; expansion with an explicit target
2155 : strips the TARGET_EXPR before we get here. */
2156 0 : new_ctx = *ctx;
2157 : /* Link CTX to NEW_CTX so that lookup_placeholder can resolve
2158 : any PLACEHOLDER_EXPR within the initializer that refers to the
2159 : former object under construction. */
2160 0 : new_ctx.parent = ctx;
2161 0 : new_ctx.ctor = build_constructor (type, NULL);
2162 0 : CONSTRUCTOR_NO_CLEARING (new_ctx.ctor) = true;
2163 0 : new_ctx.object = slot;
2164 0 : ctx->global->values.put (new_ctx.object, new_ctx.ctor);
2165 0 : ctx = &new_ctx;
2166 : }
2167 : /* Pass false for 'lval' because this indicates
2168 : initialization of a temporary. */
2169 0 : r = eval_constant_expression (ctx, TREE_OPERAND (t, 1), false,
2170 : non_constant_p, overflow_p, jump_target);
2171 0 : if (*non_constant_p)
2172 : break;
2173 : /* Adjust the type of the result to the type of the temporary. */
2174 0 : r = adjust_temp_type (type, r);
2175 0 : if (TARGET_EXPR_CLEANUP (t) && !CLEANUP_EH_ONLY (t))
2176 0 : ctx->global->cleanups->safe_push (TARGET_EXPR_CLEANUP (t));
2177 0 : r = unshare_constructor (r);
2178 0 : ctx->global->values.put (slot, r);
2179 0 : if (ctx->save_exprs)
2180 0 : ctx->save_exprs->safe_push (slot);
2181 0 : if (lval)
2182 : return slot;
2183 : }
2184 0 : break;
2185 :
2186 2405 : case CALL_EXPR:
2187 2405 : r = eval_call_expression (ctx, t, lval, non_constant_p, overflow_p,
2188 : jump_target);
2189 2405 : break;
2190 :
2191 2395 : case RETURN_EXPR:
2192 2395 : if (TREE_OPERAND (t, 0) != NULL_TREE)
2193 2395 : r = eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval,
2194 : non_constant_p, overflow_p, jump_target);
2195 : /* FALLTHRU */
2196 2395 : case BREAK_STMT:
2197 2395 : case CONTINUE_STMT:
2198 2395 : if (jump_target)
2199 2395 : *jump_target = t;
2200 : else
2201 : {
2202 : /* Can happen with ({ return true; }) && false; passed to
2203 : maybe_constant_value. There is nothing to jump over in this
2204 : case, and the bug will be diagnosed later. */
2205 0 : gcc_assert (ctx->quiet);
2206 0 : *non_constant_p = true;
2207 : }
2208 : break;
2209 :
2210 2034 : case DECL_EXPR:
2211 2034 : {
2212 2034 : r = DECL_EXPR_DECL (t);
2213 :
2214 2034 : if (AGGREGATE_TYPE_P (TREE_TYPE (r)) || VECTOR_TYPE_P (TREE_TYPE (r)))
2215 : {
2216 83 : new_ctx = *ctx;
2217 83 : new_ctx.object = r;
2218 83 : new_ctx.ctor = build_constructor (TREE_TYPE (r), NULL);
2219 83 : CONSTRUCTOR_NO_CLEARING (new_ctx.ctor) = true;
2220 83 : ctx->global->values.put (r, new_ctx.ctor);
2221 83 : ctx = &new_ctx;
2222 : }
2223 :
2224 2034 : if (tree init = DECL_INITIAL (r))
2225 : {
2226 29 : init = eval_constant_expression (ctx, init, false, non_constant_p,
2227 : overflow_p, jump_target);
2228 : /* Don't share a CONSTRUCTOR that might be changed. */
2229 29 : init = unshare_constructor (init);
2230 : /* Remember that a constant object's constructor has already
2231 : run. */
2232 29 : if (CLASS_TYPE_P (TREE_TYPE (r)) && RS_TYPE_CONST_P (TREE_TYPE (r)))
2233 0 : TREE_READONLY (init) = true;
2234 29 : ctx->global->values.put (r, init);
2235 : }
2236 2005 : else if (ctx == &new_ctx)
2237 : /* We gave it a CONSTRUCTOR above. */;
2238 : else
2239 1924 : ctx->global->values.put (r, NULL_TREE);
2240 : }
2241 2034 : break;
2242 :
2243 : /* These differ from cxx_eval_unary_expression in that this doesn't
2244 : check for a constant operand or result; an address can be
2245 : constant without its operand being, and vice versa. */
2246 3 : case MEM_REF:
2247 3 : case INDIRECT_REF:
2248 3 : r = rs_eval_indirect_ref (ctx, t, lval, non_constant_p, overflow_p,
2249 : jump_target);
2250 3 : break;
2251 :
2252 0 : case VEC_PERM_EXPR:
2253 0 : r = cxx_eval_trinary_expression (ctx, t, lval, non_constant_p, overflow_p,
2254 : jump_target);
2255 0 : break;
2256 :
2257 0 : case PAREN_EXPR:
2258 0 : gcc_assert (!REF_PARENTHESIZED_P (t));
2259 : /* A PAREN_EXPR resulting from __builtin_assoc_barrier has no effect in
2260 : constant expressions since it's unaffected by -fassociative-math. */
2261 0 : r = eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval,
2262 : non_constant_p, overflow_p, jump_target);
2263 0 : break;
2264 :
2265 2516 : case MODIFY_EXPR:
2266 2516 : r = eval_store_expression (ctx, t, false, non_constant_p, overflow_p,
2267 : jump_target);
2268 2516 : break;
2269 :
2270 264641 : case STATEMENT_LIST:
2271 264641 : new_ctx = *ctx;
2272 264641 : new_ctx.ctor = new_ctx.object = NULL_TREE;
2273 264641 : return eval_statement_list (&new_ctx, t, non_constant_p, overflow_p,
2274 264641 : jump_target);
2275 :
2276 526787 : case BIND_EXPR:
2277 526787 : return eval_constant_expression (ctx, BIND_EXPR_BODY (t), lval,
2278 526787 : non_constant_p, overflow_p, jump_target);
2279 :
2280 0 : case OBJ_TYPE_REF:
2281 : /* Virtual function lookup. We don't need to do anything fancy. */
2282 0 : return eval_constant_expression (ctx, OBJ_TYPE_REF_EXPR (t), lval,
2283 0 : non_constant_p, overflow_p, jump_target);
2284 :
2285 262160 : case EXIT_EXPR:
2286 262160 : {
2287 262160 : tree cond = TREE_OPERAND (t, 0);
2288 262160 : cond
2289 262160 : = eval_constant_expression (ctx, cond, /*lval*/ false, non_constant_p,
2290 : overflow_p, jump_target);
2291 262160 : VERIFY_CONSTANT (cond);
2292 262160 : if (integer_nonzerop (cond))
2293 4 : *jump_target = t;
2294 : }
2295 : break;
2296 :
2297 2380 : case RESULT_DECL:
2298 2380 : if (lval)
2299 : return t;
2300 : /* We ask for an rvalue for the RESULT_DECL when indirecting
2301 : through an invisible reference, or in named return value
2302 : optimization. */
2303 0 : if (tree *p = ctx->global->values.get (t))
2304 0 : return *p;
2305 : else
2306 : {
2307 0 : if (!ctx->quiet)
2308 0 : error ("%qE is not a constant expression", t);
2309 0 : *non_constant_p = true;
2310 : }
2311 0 : break;
2312 :
2313 0 : case SAVE_EXPR:
2314 : /* Avoid evaluating a SAVE_EXPR more than once. */
2315 0 : if (tree *p = ctx->global->values.get (t))
2316 0 : r = *p;
2317 : else
2318 : {
2319 0 : r = eval_constant_expression (ctx, TREE_OPERAND (t, 0), false,
2320 : non_constant_p, overflow_p,
2321 : jump_target);
2322 0 : if (*non_constant_p)
2323 : break;
2324 0 : ctx->global->values.put (t, r);
2325 0 : if (ctx->save_exprs)
2326 0 : ctx->save_exprs->safe_push (t);
2327 : }
2328 : break;
2329 :
2330 9 : case ADDR_EXPR:
2331 9 : {
2332 9 : tree oldop = TREE_OPERAND (t, 0);
2333 9 : tree op = eval_constant_expression (ctx, oldop,
2334 : /*lval*/ true, non_constant_p,
2335 : overflow_p, jump_target);
2336 : /* Don't VERIFY_CONSTANT here. */
2337 9 : if (*non_constant_p)
2338 : return t;
2339 : /* This function does more aggressive folding than fold itself. */
2340 8 : r = build_fold_addr_expr_with_type (op, TREE_TYPE (t));
2341 8 : if (TREE_CODE (r) == ADDR_EXPR && TREE_OPERAND (r, 0) == oldop)
2342 : {
2343 8 : ggc_free (r);
2344 8 : return t;
2345 : }
2346 : break;
2347 : }
2348 :
2349 0 : case COMPOUND_EXPR:
2350 0 : {
2351 : /* check_return_expr sometimes wraps a TARGET_EXPR in a
2352 : COMPOUND_EXPR; don't get confused. Also handle EMPTY_CLASS_EXPR
2353 : introduced by build_call_a. */
2354 0 : tree op0 = TREE_OPERAND (t, 0);
2355 0 : tree op1 = TREE_OPERAND (t, 1);
2356 0 : STRIP_NOPS (op1);
2357 0 : if ((TREE_CODE (op0) == TARGET_EXPR && op1 == TARGET_EXPR_SLOT (op0))
2358 0 : || TREE_CODE (op1) == EMPTY_CLASS_EXPR)
2359 0 : r = eval_constant_expression (ctx, op0, lval, non_constant_p,
2360 : overflow_p, jump_target);
2361 : else
2362 : {
2363 : /* Check that the LHS is constant and then discard it. */
2364 0 : eval_constant_expression (ctx, op0, true, non_constant_p,
2365 : overflow_p, jump_target);
2366 0 : if (*non_constant_p)
2367 : return t;
2368 0 : op1 = TREE_OPERAND (t, 1);
2369 0 : r = eval_constant_expression (ctx, op1, lval, non_constant_p,
2370 : overflow_p, jump_target);
2371 : }
2372 : }
2373 : break;
2374 :
2375 0 : case REALPART_EXPR:
2376 0 : case IMAGPART_EXPR:
2377 0 : if (lval)
2378 : {
2379 0 : r = eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval,
2380 : non_constant_p, overflow_p,
2381 : jump_target);
2382 0 : if (r == error_mark_node)
2383 : ;
2384 0 : else if (r == TREE_OPERAND (t, 0))
2385 0 : r = t;
2386 : else
2387 0 : r = fold_build1 (TREE_CODE (t), TREE_TYPE (t), r);
2388 : break;
2389 : }
2390 : /* FALLTHRU */
2391 7 : case CONJ_EXPR:
2392 7 : case FIX_TRUNC_EXPR:
2393 7 : case FLOAT_EXPR:
2394 7 : case NEGATE_EXPR:
2395 7 : case ABS_EXPR:
2396 7 : case ABSU_EXPR:
2397 7 : case BIT_NOT_EXPR:
2398 7 : case TRUTH_NOT_EXPR:
2399 7 : case FIXED_CONVERT_EXPR:
2400 7 : r = eval_unary_expression (ctx, t, lval, non_constant_p, overflow_p,
2401 : jump_target);
2402 7 : break;
2403 :
2404 2 : case GOTO_EXPR:
2405 2 : {
2406 2 : tree target = TREE_OPERAND (t, 0);
2407 4 : if (breaks (&target) || continues (&target) || returns (&target)
2408 4 : || (TREE_CODE (target) == LABEL_DECL && DECL_ARTIFICIAL (target)))
2409 : {
2410 2 : if (jump_target)
2411 2 : *jump_target = target;
2412 : else
2413 : {
2414 0 : gcc_assert (ctx->quiet);
2415 0 : *non_constant_p = true;
2416 : }
2417 : }
2418 : else
2419 : {
2420 0 : if (!ctx->quiet)
2421 0 : error_at (loc, "%<goto%> is not a constant expression");
2422 0 : *non_constant_p = true;
2423 : }
2424 : }
2425 2 : break;
2426 :
2427 5 : case LOOP_EXPR:
2428 5 : case WHILE_STMT:
2429 5 : case FOR_STMT:
2430 5 : eval_loop_expr (ctx, t, non_constant_p, overflow_p, jump_target);
2431 5 : break;
2432 :
2433 0 : case SWITCH_EXPR:
2434 0 : case SWITCH_STMT:
2435 0 : eval_switch_expr (ctx, t, non_constant_p, overflow_p, jump_target);
2436 0 : break;
2437 :
2438 9 : case ARRAY_REF:
2439 9 : r = eval_array_reference (ctx, t, lval, non_constant_p, overflow_p,
2440 : jump_target);
2441 9 : break;
2442 :
2443 11 : case COMPONENT_REF:
2444 11 : if (is_overloaded_fn (t))
2445 : {
2446 : /* We can only get here in checking mode via
2447 : build_non_dependent_expr, because any expression that
2448 : calls or takes the address of the function will have
2449 : pulled a FUNCTION_DECL out of the COMPONENT_REF. */
2450 0 : gcc_checking_assert (ctx->quiet || errorcount);
2451 0 : *non_constant_p = true;
2452 0 : return t;
2453 : }
2454 11 : r = eval_component_reference (ctx, t, lval, non_constant_p, overflow_p,
2455 : jump_target);
2456 11 : break;
2457 :
2458 0 : case BIT_FIELD_REF:
2459 0 : r = eval_bit_field_ref (ctx, t, lval, non_constant_p, overflow_p,
2460 : jump_target);
2461 0 : break;
2462 :
2463 22 : case COND_EXPR:
2464 22 : case IF_STMT: // comes from cp-tree.def
2465 22 : if (jump_target && *jump_target)
2466 : {
2467 1 : tree orig_jump = *jump_target;
2468 0 : tree arg = ((TREE_CODE (t) != IF_STMT || TREE_OPERAND (t, 1))
2469 1 : ? TREE_OPERAND (t, 1)
2470 1 : : void_node);
2471 : /* When jumping to a label, the label might be either in the
2472 : then or else blocks, so process then block first in skipping
2473 : mode first, and if we are still in the skipping mode at its end,
2474 : process the else block too. */
2475 1 : r = eval_constant_expression (ctx, arg, lval, non_constant_p,
2476 : overflow_p, jump_target);
2477 : /* It's possible that we found the label in the then block. But
2478 : it could have been followed by another jumping statement, e.g.
2479 : say we're looking for case 1:
2480 : if (cond)
2481 : {
2482 : // skipped statements
2483 : case 1:; // clears up *jump_target
2484 : return 1; // and sets it to a RETURN_EXPR
2485 : }
2486 : else { ... }
2487 : in which case we need not go looking to the else block.
2488 : (goto is not allowed in a constexpr function.) */
2489 1 : if (*jump_target == orig_jump)
2490 : {
2491 1 : arg = ((TREE_CODE (t) != IF_STMT || TREE_OPERAND (t, 2))
2492 1 : ? TREE_OPERAND (t, 2)
2493 : : void_node);
2494 1 : r = eval_constant_expression (ctx, arg, lval, non_constant_p,
2495 : overflow_p, jump_target);
2496 : }
2497 : break;
2498 : }
2499 21 : r = eval_conditional_expression (ctx, t, lval, non_constant_p, overflow_p,
2500 : jump_target);
2501 21 : break;
2502 :
2503 0 : case VEC_COND_EXPR:
2504 0 : r = eval_vector_conditional_expression (ctx, t, non_constant_p,
2505 : overflow_p, jump_target);
2506 0 : break;
2507 :
2508 0 : case TRY_CATCH_EXPR:
2509 0 : if (TREE_OPERAND (t, 0) == NULL_TREE)
2510 : {
2511 0 : r = void_node;
2512 0 : break;
2513 : }
2514 0 : r = eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval,
2515 : non_constant_p, overflow_p, jump_target);
2516 0 : break;
2517 :
2518 0 : case CLEANUP_POINT_EXPR:
2519 0 : {
2520 0 : auto_vec<tree, 2> cleanups;
2521 0 : vec<tree> *prev_cleanups = ctx->global->cleanups;
2522 0 : ctx->global->cleanups = &cleanups;
2523 0 : r = eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval,
2524 : non_constant_p, overflow_p, jump_target);
2525 0 : ctx->global->cleanups = prev_cleanups;
2526 0 : unsigned int i;
2527 0 : tree cleanup;
2528 : /* Evaluate the cleanups. */
2529 0 : FOR_EACH_VEC_ELT_REVERSE (cleanups, i, cleanup)
2530 0 : eval_constant_expression (ctx, cleanup, false, non_constant_p,
2531 : overflow_p, jump_target);
2532 0 : }
2533 0 : break;
2534 :
2535 0 : case TRY_FINALLY_EXPR:
2536 0 : r = eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval,
2537 : non_constant_p, overflow_p, jump_target);
2538 0 : if (!*non_constant_p)
2539 : /* Also evaluate the cleanup. */
2540 0 : eval_constant_expression (ctx, TREE_OPERAND (t, 1), true,
2541 : non_constant_p, overflow_p, jump_target);
2542 : break;
2543 :
2544 77 : case CONSTRUCTOR:
2545 77 : if (TREE_CONSTANT (t) && reduced_constant_expression_p (t))
2546 : {
2547 : /* Don't re-process a constant CONSTRUCTOR, but do fold it to
2548 : VECTOR_CST if applicable. */
2549 75 : verify_constructor_flags (t);
2550 75 : if (TREE_CONSTANT (t))
2551 75 : return fold (t);
2552 : }
2553 2 : r = eval_bare_aggregate (ctx, t, lval, non_constant_p, overflow_p,
2554 : jump_target);
2555 2 : break;
2556 :
2557 : /* FALLTHROUGH. */
2558 49 : case NOP_EXPR:
2559 49 : case CONVERT_EXPR:
2560 49 : case VIEW_CONVERT_EXPR:
2561 49 : {
2562 49 : tree oldop = TREE_OPERAND (t, 0);
2563 :
2564 49 : tree op = eval_constant_expression (ctx, oldop, lval, non_constant_p,
2565 : overflow_p, jump_target);
2566 49 : if (*non_constant_p)
2567 : return t;
2568 48 : tree type = TREE_TYPE (t);
2569 :
2570 48 : if (VOID_TYPE_P (type))
2571 0 : return void_node;
2572 :
2573 0 : if (TREE_CODE (t) == CONVERT_EXPR && ARITHMETIC_TYPE_P (type)
2574 48 : && INDIRECT_TYPE_P (TREE_TYPE (op)) && ctx->manifestly_const_eval)
2575 : {
2576 0 : if (!ctx->quiet)
2577 0 : error_at (loc,
2578 : "conversion from pointer type %qT to arithmetic type "
2579 : "%qT in a constant expression",
2580 0 : TREE_TYPE (op), type);
2581 0 : *non_constant_p = true;
2582 0 : return t;
2583 : }
2584 :
2585 4 : if (TYPE_PTROB_P (type) && TYPE_PTR_P (TREE_TYPE (op))
2586 49 : && VOID_TYPE_P (TREE_TYPE (TREE_TYPE (op))))
2587 : {
2588 : /* Likewise, don't error when casting from void* when OP is
2589 : &heap uninit and similar. */
2590 0 : tree sop = tree_strip_nop_conversions (op);
2591 0 : if (TREE_CODE (sop) == ADDR_EXPR && VAR_P (TREE_OPERAND (sop, 0))
2592 0 : && DECL_ARTIFICIAL (TREE_OPERAND (sop, 0)))
2593 : /* OK */;
2594 : else
2595 : {
2596 0 : if (!ctx->quiet)
2597 0 : error_at (loc, "cast from %qT is not allowed",
2598 0 : TREE_TYPE (op));
2599 0 : *non_constant_p = true;
2600 0 : return t;
2601 : }
2602 : }
2603 :
2604 48 : if (INDIRECT_TYPE_P (type) && TREE_CODE (op) == INTEGER_CST)
2605 : {
2606 0 : if (integer_zerop (op))
2607 : {
2608 0 : if (TYPE_REF_P (type))
2609 : {
2610 0 : if (!ctx->quiet)
2611 0 : error_at (loc, "dereferencing a null pointer");
2612 0 : *non_constant_p = true;
2613 0 : return t;
2614 : }
2615 : }
2616 : else
2617 : {
2618 : /* This detects for example:
2619 : reinterpret_cast<void*>(sizeof 0)
2620 : */
2621 0 : if (!ctx->quiet)
2622 0 : error_at (loc,
2623 : "%<reinterpret_cast<%T>(%E)%> is not "
2624 : "a constant expression",
2625 : type, op);
2626 0 : *non_constant_p = true;
2627 0 : return t;
2628 : }
2629 : }
2630 :
2631 4 : if (INDIRECT_TYPE_P (type) && TREE_CODE (op) == NOP_EXPR
2632 1 : && TREE_TYPE (op) == ptr_type_node
2633 0 : && TREE_CODE (TREE_OPERAND (op, 0)) == ADDR_EXPR
2634 0 : && VAR_P (TREE_OPERAND (TREE_OPERAND (op, 0), 0))
2635 48 : && (DECL_NAME (TREE_OPERAND (TREE_OPERAND (op, 0), 0))
2636 0 : == heap_uninit_identifier
2637 0 : || DECL_NAME (TREE_OPERAND (TREE_OPERAND (op, 0), 0))
2638 0 : == heap_vec_uninit_identifier))
2639 : {
2640 0 : tree var = TREE_OPERAND (TREE_OPERAND (op, 0), 0);
2641 0 : tree var_size = TYPE_SIZE_UNIT (TREE_TYPE (var));
2642 0 : tree elt_type = TREE_TYPE (type);
2643 0 : tree cookie_size = NULL_TREE;
2644 0 : if (TREE_CODE (elt_type) == RECORD_TYPE
2645 0 : && TYPE_NAME (elt_type) == heap_identifier)
2646 : {
2647 0 : tree fld1 = TYPE_FIELDS (elt_type);
2648 0 : tree fld2 = DECL_CHAIN (fld1);
2649 0 : elt_type = TREE_TYPE (TREE_TYPE (fld2));
2650 0 : cookie_size = TYPE_SIZE_UNIT (TREE_TYPE (fld1));
2651 : }
2652 0 : DECL_NAME (var) = (DECL_NAME (var) == heap_uninit_identifier
2653 0 : ? heap_identifier
2654 : : heap_vec_identifier);
2655 0 : TREE_TYPE (var)
2656 0 : = build_new_constexpr_heap_type (elt_type, cookie_size, var_size);
2657 0 : TREE_TYPE (TREE_OPERAND (op, 0))
2658 0 : = build_pointer_type (TREE_TYPE (var));
2659 : }
2660 :
2661 48 : if (op == oldop)
2662 : /* We didn't fold at the top so we could check for ptr-int
2663 : conversion. */
2664 3 : return fold (t);
2665 :
2666 45 : tree sop;
2667 :
2668 : /* Handle an array's bounds having been deduced after we built
2669 : the wrapping expression. */
2670 45 : if (same_type_ignoring_tlq_and_bounds_p (type, TREE_TYPE (op)))
2671 44 : r = op;
2672 1 : else if (sop = tree_strip_nop_conversions (op),
2673 : sop != op
2674 1 : && (same_type_ignoring_tlq_and_bounds_p (type,
2675 0 : TREE_TYPE (sop))))
2676 0 : r = sop;
2677 : else
2678 1 : r = fold_build1 (tcode, type, op);
2679 :
2680 : /* Conversion of an out-of-range value has implementation-defined
2681 : behavior; the language considers it different from arithmetic
2682 : overflow, which is undefined. */
2683 45 : if (TREE_OVERFLOW_P (r) && !TREE_OVERFLOW_P (op))
2684 0 : TREE_OVERFLOW (r) = false;
2685 : }
2686 : break;
2687 :
2688 0 : case PLACEHOLDER_EXPR:
2689 : /* Use of the value or address of the current object. */
2690 0 : if (tree ctor = lookup_placeholder (ctx, lval, TREE_TYPE (t)))
2691 : {
2692 0 : if (TREE_CODE (ctor) == CONSTRUCTOR)
2693 : return ctor;
2694 : else
2695 0 : return eval_constant_expression (ctx, ctor, lval, non_constant_p,
2696 0 : overflow_p, jump_target);
2697 : }
2698 : /* A placeholder without a referent. We can get here when
2699 : checking whether NSDMIs are noexcept, or in massage_init_elt;
2700 : just say it's non-constant for now. */
2701 0 : gcc_assert (ctx->quiet);
2702 0 : *non_constant_p = true;
2703 0 : break;
2704 :
2705 0 : case ANNOTATE_EXPR:
2706 0 : r = eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval,
2707 : non_constant_p, overflow_p, jump_target);
2708 0 : break;
2709 :
2710 0 : case ASM_EXPR:
2711 0 : if (!ctx->quiet)
2712 0 : inline_asm_in_constexpr_error (loc);
2713 0 : *non_constant_p = true;
2714 0 : return t;
2715 :
2716 : default:
2717 : break;
2718 : }
2719 :
2720 535800 : return r;
2721 : }
2722 :
2723 : /* Complain about a const object OBJ being modified in a constant expression.
2724 : EXPR is the MODIFY_EXPR expression performing the modification. */
2725 :
2726 : static void
2727 0 : modifying_const_object_error (tree expr, tree obj)
2728 : {
2729 0 : location_t loc = EXPR_LOCATION (expr);
2730 0 : auto_diagnostic_group d;
2731 0 : error_at (loc,
2732 : "modifying a const object %qE is not allowed in "
2733 : "a constant expression",
2734 0 : TREE_OPERAND (expr, 0));
2735 0 : inform (location_of (obj), "originally declared %<const%> here");
2736 0 : }
2737 :
2738 : /* Return true iff DECL is an empty field, either for an empty base or a
2739 : [[no_unique_address]] data member. */
2740 :
2741 : bool
2742 1 : is_empty_field (tree decl)
2743 : {
2744 1 : if (!decl || TREE_CODE (decl) != FIELD_DECL)
2745 : return false;
2746 :
2747 1 : bool r = is_empty_class (TREE_TYPE (decl));
2748 :
2749 : /* Empty fields should have size zero. */
2750 1 : gcc_checking_assert (!r || integer_zerop (DECL_SIZE (decl)));
2751 :
2752 : return r;
2753 : }
2754 :
2755 : static tree
2756 2516 : eval_store_expression (const constexpr_ctx *ctx, tree t, bool lval,
2757 : bool *non_constant_p, bool *overflow_p,
2758 : tree *jump_target)
2759 : {
2760 2516 : constexpr_ctx new_ctx = *ctx;
2761 :
2762 2516 : tree init = TREE_OPERAND (t, 1);
2763 2516 : if (TREE_CLOBBER_P (init))
2764 : /* Just ignore clobbers. */
2765 0 : return void_node;
2766 :
2767 : /* First we figure out where we're storing to. */
2768 2516 : tree target = TREE_OPERAND (t, 0);
2769 :
2770 2516 : tree type = TREE_TYPE (target);
2771 2516 : bool preeval = SCALAR_TYPE_P (type) || TREE_CODE (t) == MODIFY_EXPR;
2772 : if (preeval)
2773 : {
2774 : /* Evaluate the value to be stored without knowing what object it will be
2775 : stored in, so that any side-effects happen first. */
2776 2516 : if (!SCALAR_TYPE_P (type))
2777 : {
2778 84 : new_ctx.ctor = new_ctx.object = NULL_TREE;
2779 84 : if (TREE_CODE (init) == CONSTRUCTOR)
2780 : {
2781 71 : new_ctx.ctor = build_constructor (TREE_TYPE (init), NULL);
2782 71 : CONSTRUCTOR_NO_CLEARING (new_ctx.ctor) = true;
2783 : }
2784 : }
2785 2516 : init = eval_constant_expression (&new_ctx, init, false, non_constant_p,
2786 : overflow_p, jump_target);
2787 2516 : if (*non_constant_p)
2788 : return t;
2789 : }
2790 :
2791 2500 : bool evaluated = false;
2792 2500 : if (lval)
2793 : {
2794 : /* If we want to return a reference to the target, we need to evaluate it
2795 : as a whole; otherwise, only evaluate the innermost piece to avoid
2796 : building up unnecessary *_REFs. */
2797 0 : target = eval_constant_expression (ctx, target, true, non_constant_p,
2798 : overflow_p, jump_target);
2799 0 : evaluated = true;
2800 0 : if (*non_constant_p)
2801 : return t;
2802 : }
2803 :
2804 : /* Find the underlying variable. */
2805 2500 : releasing_vec refs;
2806 2500 : tree object = NULL_TREE;
2807 : /* If we're modifying a const object, save it. */
2808 2500 : tree const_object_being_modified = NULL_TREE;
2809 : // bool mutable_p = false;
2810 7502 : for (tree probe = target; object == NULL_TREE;)
2811 : {
2812 5002 : switch (TREE_CODE (probe))
2813 : {
2814 2 : case BIT_FIELD_REF:
2815 2 : case COMPONENT_REF:
2816 2 : case ARRAY_REF:
2817 2 : {
2818 2 : tree ob = TREE_OPERAND (probe, 0);
2819 2 : tree elt = TREE_OPERAND (probe, 1);
2820 2 : if (TREE_CODE (elt) == FIELD_DECL /*&& DECL_MUTABLE_P (elt)*/)
2821 : {
2822 : // mutable_p = true;
2823 : }
2824 2 : if (TREE_CODE (probe) == ARRAY_REF)
2825 : {
2826 1 : elt = eval_and_check_array_index (ctx, probe, false,
2827 : non_constant_p, overflow_p,
2828 : jump_target);
2829 1 : if (*non_constant_p)
2830 0 : return t;
2831 : }
2832 : /* We don't check modifying_const_object_p for ARRAY_REFs. Given
2833 : "int a[10]", an ARRAY_REF "a[2]" can be "const int", even though
2834 : the array isn't const. Instead, check "a" in the next iteration;
2835 : that will detect modifying "const int a[10]". */
2836 : // else if (evaluated
2837 : // && modifying_const_object_p (TREE_CODE (t), probe,
2838 : // mutable_p)
2839 : // && const_object_being_modified == NULL_TREE)
2840 : // const_object_being_modified = probe;
2841 2 : vec_safe_push (refs, elt);
2842 2 : vec_safe_push (refs, TREE_TYPE (probe));
2843 2 : probe = ob;
2844 : }
2845 2 : break;
2846 :
2847 5000 : default:
2848 5000 : if (evaluated)
2849 2500 : object = probe;
2850 : else
2851 : {
2852 2500 : probe
2853 2500 : = eval_constant_expression (ctx, probe, true, non_constant_p,
2854 : overflow_p, jump_target);
2855 2500 : evaluated = true;
2856 2500 : if (*non_constant_p)
2857 : return t;
2858 : }
2859 : break;
2860 : }
2861 : }
2862 :
2863 : // if (modifying_const_object_p (TREE_CODE (t), object, mutable_p)
2864 : // && const_object_being_modified == NULL_TREE)
2865 : // const_object_being_modified = object;
2866 :
2867 : /* And then find/build up our initializer for the path to the subobject
2868 : we're initializing. */
2869 2500 : tree *valp;
2870 2500 : if (DECL_P (object))
2871 2500 : valp = ctx->global->values.get (object);
2872 : else
2873 : valp = NULL;
2874 2500 : if (!valp)
2875 : {
2876 : /* A constant-expression cannot modify objects from outside the
2877 : constant-expression. */
2878 0 : if (!ctx->quiet)
2879 0 : error ("modification of %qE is not a constant expression", object);
2880 0 : *non_constant_p = true;
2881 0 : return t;
2882 : }
2883 2500 : type = TREE_TYPE (object);
2884 2500 : bool no_zero_init = true;
2885 :
2886 5000 : releasing_vec ctors, indexes;
2887 5000 : auto_vec<int> index_pos_hints;
2888 2500 : bool activated_union_member_p = false;
2889 2502 : while (!refs->is_empty ())
2890 : {
2891 2 : if (*valp == NULL_TREE)
2892 : {
2893 0 : *valp = build_constructor (type, NULL);
2894 0 : CONSTRUCTOR_NO_CLEARING (*valp) = no_zero_init;
2895 : }
2896 2 : else if (TREE_CODE (*valp) == STRING_CST)
2897 : {
2898 : /* An array was initialized with a string constant, and now
2899 : we're writing into one of its elements. Explode the
2900 : single initialization into a set of element
2901 : initializations. */
2902 0 : gcc_assert (TREE_CODE (type) == ARRAY_TYPE);
2903 :
2904 0 : tree string = *valp;
2905 0 : tree elt_type = TREE_TYPE (type);
2906 0 : unsigned chars_per_elt
2907 0 : = (TYPE_PRECISION (elt_type) / TYPE_PRECISION (char_type_node));
2908 0 : unsigned num_elts = TREE_STRING_LENGTH (string) / chars_per_elt;
2909 0 : tree ary_ctor = build_constructor (type, NULL);
2910 :
2911 0 : vec_safe_reserve (CONSTRUCTOR_ELTS (ary_ctor), num_elts);
2912 0 : for (unsigned ix = 0; ix != num_elts; ix++)
2913 : {
2914 0 : constructor_elt elt
2915 0 : = {build_int_cst (size_type_node, ix),
2916 0 : extract_string_elt (string, chars_per_elt, ix)};
2917 0 : CONSTRUCTOR_ELTS (ary_ctor)->quick_push (elt);
2918 : }
2919 :
2920 0 : *valp = ary_ctor;
2921 : }
2922 :
2923 : /* If the value of object is already zero-initialized, any new ctors for
2924 : subobjects will also be zero-initialized. */
2925 2 : no_zero_init = CONSTRUCTOR_NO_CLEARING (*valp);
2926 :
2927 2 : enum tree_code code = TREE_CODE (type);
2928 2 : type = refs->pop ();
2929 2 : tree index = refs->pop ();
2930 :
2931 2 : if (code == RECORD_TYPE && is_empty_field (index))
2932 : /* Don't build a sub-CONSTRUCTOR for an empty base or field, as they
2933 : have no data and might have an offset lower than previously declared
2934 : fields, which confuses the middle-end. The code below will notice
2935 : that we don't have a CONSTRUCTOR for our inner target and just
2936 : return init. */
2937 : break;
2938 :
2939 0 : if (code == UNION_TYPE && CONSTRUCTOR_NELTS (*valp)
2940 2 : && CONSTRUCTOR_ELT (*valp, 0)->index != index)
2941 : {
2942 0 : if (TREE_CODE (t) == MODIFY_EXPR && CONSTRUCTOR_NO_CLEARING (*valp))
2943 : {
2944 : /* Diagnose changing the active union member while the union
2945 : is in the process of being initialized. */
2946 0 : if (!ctx->quiet)
2947 0 : error_at (EXPR_LOCATION (t),
2948 : "change of the active member of a union "
2949 : "from %qD to %qD during initialization",
2950 0 : CONSTRUCTOR_ELT (*valp, 0)->index, index);
2951 0 : *non_constant_p = true;
2952 : }
2953 : no_zero_init = true;
2954 : }
2955 :
2956 2 : vec_safe_push (ctors, *valp);
2957 2 : vec_safe_push (indexes, index);
2958 :
2959 2 : constructor_elt *cep = get_or_insert_ctor_field (*valp, index);
2960 2 : index_pos_hints.safe_push (cep - CONSTRUCTOR_ELTS (*valp)->begin ());
2961 :
2962 2 : if (code == UNION_TYPE)
2963 0 : activated_union_member_p = true;
2964 :
2965 2 : valp = &cep->value;
2966 : }
2967 :
2968 : /* Detect modifying a constant object in constexpr evaluation.
2969 : We have found a const object that is being modified. Figure out
2970 : if we need to issue an error. Consider
2971 :
2972 : struct A {
2973 : int n;
2974 : constexpr A() : n(1) { n = 2; } // #1
2975 : };
2976 : struct B {
2977 : const A a;
2978 : constexpr B() { a.n = 3; } // #2
2979 : };
2980 : constexpr B b{};
2981 :
2982 : #1 is OK, since we're modifying an object under construction, but
2983 : #2 is wrong, since "a" is const and has been fully constructed.
2984 : To track it, we use the TREE_READONLY bit in the object's CONSTRUCTOR
2985 : which means that the object is read-only. For the example above, the
2986 : *ctors stack at the point of #2 will look like:
2987 :
2988 : ctors[0] = {.a={.n=2}} TREE_READONLY = 0
2989 : ctors[1] = {.n=2} TREE_READONLY = 1
2990 :
2991 : and we're modifying "b.a", so we search the stack and see if the
2992 : constructor for "b.a" has already run. */
2993 2500 : if (const_object_being_modified)
2994 : {
2995 : bool fail = false;
2996 : tree const_objtype
2997 : = strip_array_types (TREE_TYPE (const_object_being_modified));
2998 : if (!CLASS_TYPE_P (const_objtype))
2999 : fail = true;
3000 : else
3001 : {
3002 : /* [class.ctor]p5 "A constructor can be invoked for a const,
3003 : volatile, or const volatile object. const and volatile
3004 : semantics are not applied on an object under construction.
3005 : They come into effect when the constructor for the most
3006 : derived object ends." */
3007 : for (tree elt : *ctors)
3008 : if (same_type_ignoring_top_level_qualifiers_p (
3009 : TREE_TYPE (const_object_being_modified), TREE_TYPE (elt)))
3010 : {
3011 : fail = TREE_READONLY (elt);
3012 : break;
3013 : }
3014 : }
3015 : if (fail)
3016 : {
3017 : if (!ctx->quiet)
3018 : modifying_const_object_error (t, const_object_being_modified);
3019 : *non_constant_p = true;
3020 : return t;
3021 : }
3022 : }
3023 :
3024 2500 : if (!preeval)
3025 : {
3026 : /* We're handling an INIT_EXPR of class type, so the value of the
3027 : initializer can depend on the object it's initializing. */
3028 :
3029 : /* Create a new CONSTRUCTOR in case evaluation of the initializer
3030 : wants to modify it. */
3031 0 : if (*valp == NULL_TREE)
3032 : {
3033 0 : *valp = build_constructor (type, NULL);
3034 0 : CONSTRUCTOR_NO_CLEARING (*valp) = no_zero_init;
3035 : }
3036 0 : new_ctx.ctor = *valp;
3037 0 : new_ctx.object = target;
3038 : /* Avoid temporary materialization when initializing from a TARGET_EXPR.
3039 : We don't need to mess with AGGR_EXPR_SLOT/VEC_INIT_EXPR_SLOT because
3040 : expansion of those trees uses ctx instead. */
3041 0 : if (TREE_CODE (init) == TARGET_EXPR)
3042 0 : if (tree tinit = TARGET_EXPR_INITIAL (init))
3043 0 : init = tinit;
3044 0 : init = eval_constant_expression (&new_ctx, init, false, non_constant_p,
3045 : overflow_p, jump_target);
3046 : /* The hash table might have moved since the get earlier, and the
3047 : initializer might have mutated the underlying CONSTRUCTORs, so we must
3048 : recompute VALP. */
3049 0 : valp = ctx->global->values.get (object);
3050 0 : for (unsigned i = 0; i < vec_safe_length (indexes); i++)
3051 : {
3052 0 : constructor_elt *cep
3053 0 : = get_or_insert_ctor_field (*valp, indexes[i], index_pos_hints[i]);
3054 0 : valp = &cep->value;
3055 : }
3056 : }
3057 :
3058 2500 : if (*non_constant_p)
3059 : return t;
3060 :
3061 : /* Don't share a CONSTRUCTOR that might be changed later. */
3062 2500 : init = unshare_constructor (init);
3063 2500 : if (init == NULL_TREE)
3064 : return t;
3065 :
3066 2500 : if (*valp && TREE_CODE (*valp) == CONSTRUCTOR
3067 4 : && TREE_CODE (init) == CONSTRUCTOR)
3068 : {
3069 : /* An outer ctx->ctor might be pointing to *valp, so replace
3070 : its contents. */
3071 4 : if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (init),
3072 4 : TREE_TYPE (*valp)))
3073 : {
3074 : /* For initialization of an empty base, the original target will be
3075 : *(base*)this, evaluation of which resolves to the object
3076 : argument, which has the derived type rather than the base type. In
3077 : this situation, just evaluate the initializer and return, since
3078 : there's no actual data to store. */
3079 0 : gcc_assert (is_empty_class (TREE_TYPE (init)));
3080 0 : return lval ? target : init;
3081 : }
3082 4 : CONSTRUCTOR_ELTS (*valp) = CONSTRUCTOR_ELTS (init);
3083 4 : TREE_CONSTANT (*valp) = TREE_CONSTANT (init);
3084 4 : TREE_SIDE_EFFECTS (*valp) = TREE_SIDE_EFFECTS (init);
3085 4 : CONSTRUCTOR_NO_CLEARING (*valp) = CONSTRUCTOR_NO_CLEARING (init);
3086 : }
3087 : // else if (TREE_CODE (init) == CONSTRUCTOR
3088 : // && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (init),
3089 : // type))
3090 : // {
3091 : // /* See above on initialization of empty bases. */
3092 : // // gcc_assert (is_empty_class (TREE_TYPE (init)) && !lval);
3093 : // return init;
3094 : // }
3095 : else
3096 2496 : *valp = init;
3097 :
3098 : /* After initialization, 'const' semantics apply to the value of the
3099 : object. Make a note of this fact by marking the CONSTRUCTOR
3100 : TREE_READONLY. */
3101 0 : if (TREE_CODE (t) == INIT_EXPR && TREE_CODE (*valp) == CONSTRUCTOR
3102 2500 : && TYPE_READONLY (type))
3103 : {
3104 : // this vs self? can rust's self be anything other than self or &self in
3105 : // constexpr mode? if (INDIRECT_REF_P (target)
3106 : // && (is_this_parameter (
3107 : // tree_strip_nop_conversions (TREE_OPERAND (target, 0)))))
3108 : /* We've just initialized '*this' (perhaps via the target
3109 : constructor of a delegating constructor). Leave it up to the
3110 : caller that set 'this' to set TREE_READONLY appropriately. */
3111 : // gcc_checking_assert (
3112 : // same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (target),
3113 : // type));
3114 : // else
3115 : // TREE_READONLY (*valp) = true;
3116 : }
3117 :
3118 : /* Update TREE_CONSTANT and TREE_SIDE_EFFECTS on enclosing
3119 : CONSTRUCTORs, if any. */
3120 2500 : bool c = TREE_CONSTANT (init);
3121 2500 : bool s = TREE_SIDE_EFFECTS (init);
3122 2500 : if (!c || s || activated_union_member_p)
3123 4 : for (tree elt : *ctors)
3124 : {
3125 0 : if (!c)
3126 0 : TREE_CONSTANT (elt) = false;
3127 0 : if (s)
3128 0 : TREE_SIDE_EFFECTS (elt) = true;
3129 : /* Clear CONSTRUCTOR_NO_CLEARING since we've activated a member of
3130 : this union. */
3131 0 : if (TREE_CODE (TREE_TYPE (elt)) == UNION_TYPE)
3132 0 : CONSTRUCTOR_NO_CLEARING (elt) = false;
3133 : }
3134 :
3135 2500 : if (*non_constant_p)
3136 : return t;
3137 2500 : else if (lval)
3138 : return target;
3139 : else
3140 2500 : return init;
3141 2500 : }
3142 :
3143 : /* Subroutine of cxx_eval_constant_expression.
3144 : Like cxx_eval_unary_expression, except for binary expressions. */
3145 : static tree
3146 349 : eval_binary_expression (const constexpr_ctx *ctx, tree t, bool lval,
3147 : bool *non_constant_p, bool *overflow_p,
3148 : tree *jump_target)
3149 : {
3150 349 : tree r = NULL_TREE;
3151 349 : tree orig_lhs = TREE_OPERAND (t, 0);
3152 349 : tree orig_rhs = TREE_OPERAND (t, 1);
3153 349 : tree lhs, rhs;
3154 349 : lhs = eval_constant_expression (ctx, orig_lhs, lval, non_constant_p,
3155 : overflow_p, jump_target);
3156 : /* Don't VERIFY_CONSTANT here, it's unnecessary and will break pointer
3157 : subtraction. */
3158 349 : if (*non_constant_p)
3159 : return t;
3160 348 : if (*jump_target)
3161 : return NULL_TREE;
3162 :
3163 348 : rhs = eval_constant_expression (ctx, orig_rhs, lval, non_constant_p,
3164 : overflow_p, jump_target);
3165 348 : if (*non_constant_p)
3166 : return t;
3167 348 : if (*jump_target)
3168 : return NULL_TREE;
3169 :
3170 348 : location_t loc = EXPR_LOCATION (t);
3171 348 : enum tree_code code = TREE_CODE (t);
3172 348 : tree type = TREE_TYPE (t);
3173 :
3174 348 : if (code == EQ_EXPR || code == NE_EXPR)
3175 : {
3176 19 : bool is_code_eq = (code == EQ_EXPR);
3177 :
3178 19 : if (TREE_CODE (lhs) == PTRMEM_CST && TREE_CODE (rhs) == PTRMEM_CST)
3179 : {
3180 0 : tree lmem = PTRMEM_CST_MEMBER (lhs);
3181 0 : tree rmem = PTRMEM_CST_MEMBER (rhs);
3182 0 : bool eq = false;
3183 0 : if (TREE_CODE (lmem) == TREE_CODE (rmem)
3184 0 : && TREE_CODE (lmem) == FIELD_DECL
3185 0 : && TREE_CODE (DECL_CONTEXT (lmem)) == UNION_TYPE
3186 0 : && same_type_p (DECL_CONTEXT (lmem), DECL_CONTEXT (rmem)))
3187 : /* If both refer to (possibly different) members of the same union
3188 : (12.3), they compare equal. */
3189 : eq = true;
3190 : // else
3191 : // eq = cp_tree_equal (lhs, rhs);
3192 0 : r = constant_boolean_node (eq == is_code_eq, type);
3193 0 : }
3194 19 : else if ((TREE_CODE (lhs) == PTRMEM_CST || TREE_CODE (rhs) == PTRMEM_CST)
3195 19 : && (null_member_pointer_value_p (lhs)
3196 0 : || null_member_pointer_value_p (rhs)))
3197 0 : r = constant_boolean_node (!is_code_eq, type);
3198 : }
3199 348 : if (r == NULL_TREE && TREE_CODE_CLASS (code) == tcc_comparison
3200 30 : && POINTER_TYPE_P (TREE_TYPE (lhs)))
3201 : {
3202 1 : lhs = maybe_fold_reference_address_to_pointer (lhs);
3203 1 : rhs = maybe_fold_reference_address_to_pointer (rhs);
3204 :
3205 1 : if (tree lhso = maybe_fold_addr_pointer_plus (lhs))
3206 0 : lhs = fold_convert (TREE_TYPE (lhs), lhso);
3207 1 : if (tree rhso = maybe_fold_addr_pointer_plus (rhs))
3208 0 : rhs = fold_convert (TREE_TYPE (rhs), rhso);
3209 : }
3210 0 : if (code == POINTER_PLUS_EXPR && !*non_constant_p && integer_zerop (lhs)
3211 348 : && !integer_zerop (rhs))
3212 : {
3213 0 : if (!ctx->quiet)
3214 0 : error ("arithmetic involving a null pointer in %qE", lhs);
3215 0 : *non_constant_p = true;
3216 0 : return t;
3217 : }
3218 348 : else if (code == POINTER_PLUS_EXPR)
3219 : {
3220 0 : r = fold_pointer_plus_expression (ctx, t, lhs, rhs, non_constant_p,
3221 : overflow_p, jump_target);
3222 0 : if (*jump_target)
3223 : return NULL_TREE;
3224 : }
3225 :
3226 348 : if (r == NULL_TREE)
3227 : {
3228 348 : if (ctx->manifestly_const_eval && TREE_CODE (type) != REAL_TYPE)
3229 334 : r = fold_binary_initializer_loc (loc, code, type, lhs, rhs);
3230 : else
3231 14 : r = fold_binary_loc (loc, code, type, lhs, rhs);
3232 : }
3233 :
3234 2 : if (r == NULL_TREE && (code == LSHIFT_EXPR || code == RSHIFT_EXPR)
3235 0 : && TREE_CODE (lhs) == INTEGER_CST && TREE_CODE (rhs) == INTEGER_CST
3236 350 : && wi::neg_p (wi::to_wide (rhs)))
3237 : {
3238 : /* For diagnostics and -fpermissive emulate previous behavior of
3239 : handling shifts by negative amount. */
3240 0 : tree nrhs = const_unop (NEGATE_EXPR, TREE_TYPE (rhs), rhs);
3241 0 : if (nrhs)
3242 0 : r = fold_binary_loc (loc,
3243 : code == LSHIFT_EXPR ? RSHIFT_EXPR : LSHIFT_EXPR,
3244 : type, lhs, nrhs);
3245 : }
3246 :
3247 348 : if (r == NULL_TREE)
3248 : {
3249 2 : if (lhs == orig_lhs && rhs == orig_rhs)
3250 : r = t;
3251 : else
3252 0 : r = build2_loc (loc, code, type, lhs, rhs);
3253 : }
3254 346 : else if (eval_check_shift_p (loc, ctx, code, type, lhs, rhs))
3255 0 : *non_constant_p = true;
3256 346 : else if (eval_check_overflow_p (loc, ctx, code, type, lhs, rhs))
3257 : {
3258 11 : *non_constant_p = true;
3259 : /* The overflow has been diagnosed here, with a location. Clear the
3260 : flag so that the generic TREE_OVERFLOW check in
3261 : eval_constant_expression does not report it a second time against
3262 : the folded constant, which carries no location. */
3263 11 : if (r != NULL_TREE && CONSTANT_CLASS_P (r))
3264 11 : TREE_OVERFLOW (r) = false;
3265 : }
3266 : /* Don't VERIFY_CONSTANT if this might be dealing with a pointer to
3267 : a local array in a constexpr function. */
3268 348 : bool ptr = INDIRECT_TYPE_P (TREE_TYPE (lhs));
3269 347 : if (!ptr)
3270 347 : VERIFY_CONSTANT (r);
3271 : return r;
3272 : }
3273 :
3274 : /* Helper function of cxx_bind_parameters_in_call. Return non-NULL
3275 : if *TP is address of a static variable (or part of it) currently being
3276 : constructed or of a heap artificial variable. */
3277 :
3278 : static tree
3279 24 : addr_of_non_const_var (tree *tp, int *walk_subtrees, void *data)
3280 : {
3281 24 : if (TREE_CODE (*tp) == ADDR_EXPR)
3282 4 : if (tree var = get_base_address (TREE_OPERAND (*tp, 0)))
3283 4 : if (VAR_P (var) && TREE_STATIC (var))
3284 : {
3285 0 : if (DECL_NAME (var) == heap_uninit_identifier
3286 0 : || DECL_NAME (var) == heap_identifier
3287 0 : || DECL_NAME (var) == heap_vec_uninit_identifier
3288 0 : || DECL_NAME (var) == heap_vec_identifier)
3289 0 : return var;
3290 :
3291 0 : constexpr_global_ctx *global = (constexpr_global_ctx *) data;
3292 0 : if (global->values.get (var))
3293 : return var;
3294 : }
3295 24 : if (TYPE_P (*tp))
3296 0 : *walk_subtrees = false;
3297 : return NULL_TREE;
3298 : }
3299 :
3300 : /* Subroutine of cxx_eval_call_expression.
3301 : We are processing a call expression (either CALL_EXPR or
3302 : AGGR_INIT_EXPR) in the context of CTX. Evaluate
3303 : all arguments and bind their values to correspondings
3304 : parameters, making up the NEW_CALL context. */
3305 :
3306 : static tree
3307 2405 : rs_bind_parameters_in_call (const constexpr_ctx *ctx, tree t, tree fun,
3308 : bool *non_constant_p, bool *overflow_p,
3309 : bool *non_constant_args, tree *jump_target)
3310 : {
3311 2405 : const int nargs = call_expr_nargs (t);
3312 2405 : tree parms = DECL_ARGUMENTS (fun);
3313 2405 : int i;
3314 : /* We don't record ellipsis args below. */
3315 2405 : int nparms = list_length (parms);
3316 2405 : int nbinds = nargs < nparms ? nargs : nparms;
3317 2405 : tree binds = make_tree_vec (nbinds);
3318 4826 : for (i = 0; i < nargs; ++i)
3319 : {
3320 16 : tree x, arg;
3321 16 : tree type = parms ? TREE_TYPE (parms) : void_type_node;
3322 16 : if (parms && DECL_BY_REFERENCE (parms))
3323 0 : type = TREE_TYPE (type);
3324 16 : x = CALL_EXPR_ARG (t, i);
3325 :
3326 16 : if (TREE_ADDRESSABLE (type))
3327 : /* Undo convert_for_arg_passing work here. */
3328 0 : x = convert_from_reference (x);
3329 : /* Normally we would strip a TARGET_EXPR in an initialization context
3330 : such as this, but here we do the elision differently: we keep the
3331 : TARGET_EXPR, and use its CONSTRUCTOR as the value of the parm. */
3332 16 : arg = eval_constant_expression (ctx, x, /*lval=*/false, non_constant_p,
3333 : overflow_p, jump_target);
3334 : /* Don't VERIFY_CONSTANT here. */
3335 16 : if (*non_constant_p && ctx->quiet)
3336 : break;
3337 : /* Just discard ellipsis args after checking their constantitude. */
3338 16 : if (!parms)
3339 0 : continue;
3340 :
3341 16 : if (!*non_constant_p)
3342 : {
3343 : /* Make sure the binding has the same type as the parm. But
3344 : only for constant args. */
3345 16 : if (!TYPE_REF_P (type))
3346 14 : arg = adjust_temp_type (type, arg);
3347 16 : if (!TREE_CONSTANT (arg))
3348 0 : *non_constant_args = true;
3349 16 : else if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
3350 : /* The destructor needs to see any modifications the callee makes
3351 : to the argument. */
3352 0 : *non_constant_args = true;
3353 : /* If arg is or contains address of a heap artificial variable or
3354 : of a static variable being constructed, avoid caching the
3355 : function call, as those variables might be modified by the
3356 : function, or might be modified by the callers in between
3357 : the cached function and just read by the function. */
3358 16 : else if (!*non_constant_args
3359 16 : && rs_walk_tree (&arg, addr_of_non_const_var, ctx->global,
3360 : NULL))
3361 0 : *non_constant_args = true;
3362 :
3363 : // /* For virtual calls, adjust the this argument, so that it is
3364 : // the object on which the method is called, rather than
3365 : // one of its bases. */
3366 : // if (i == 0 && DECL_VIRTUAL_P (fun))
3367 : // {
3368 : // tree addr = arg;
3369 : // STRIP_NOPS (addr);
3370 : // if (TREE_CODE (addr) == ADDR_EXPR)
3371 : // {
3372 : // tree obj = TREE_OPERAND (addr, 0);
3373 : // while (TREE_CODE (obj) == COMPONENT_REF
3374 : // && DECL_FIELD_IS_BASE (TREE_OPERAND (obj, 1))
3375 : // && !same_type_ignoring_top_level_qualifiers_p (
3376 : // TREE_TYPE (obj), DECL_CONTEXT (fun)))
3377 : // obj = TREE_OPERAND (obj, 0);
3378 : // if (obj != TREE_OPERAND (addr, 0))
3379 : // arg = build_fold_addr_expr_with_type (obj, TREE_TYPE
3380 : // (arg));
3381 : // }
3382 : // }
3383 16 : TREE_VEC_ELT (binds, i) = arg;
3384 : }
3385 16 : parms = TREE_CHAIN (parms);
3386 : }
3387 :
3388 2405 : return binds;
3389 : }
3390 :
3391 : // forked from gcc/cp/constexpr.cc cxx_eval_builtin_function_call
3392 :
3393 : /* Attempt to evaluate T which represents a call to a builtin function.
3394 : We assume here that all builtin functions evaluate to scalar types
3395 : represented by _CST nodes. */
3396 :
3397 : static tree
3398 0 : eval_builtin_function_call (const constexpr_ctx *ctx, tree t, tree fun,
3399 : bool lval, bool *non_constant_p, bool *overflow_p,
3400 : tree *jump_target)
3401 : {
3402 0 : const int nargs = call_expr_nargs (t);
3403 0 : tree *args = (tree *) alloca (nargs * sizeof (tree));
3404 0 : tree new_call;
3405 0 : int i;
3406 :
3407 : /* Don't fold __builtin_constant_p within a constexpr function. */
3408 0 : bool bi_const_p = DECL_IS_BUILTIN_CONSTANT_P (fun);
3409 :
3410 : /* If we aren't requiring a constant expression, defer __builtin_constant_p
3411 : in a constexpr function until we have values for the parameters. */
3412 0 : if (bi_const_p && !ctx->manifestly_const_eval && current_function_decl
3413 0 : && DECL_DECLARED_CONSTEXPR_P (current_function_decl))
3414 : {
3415 0 : *non_constant_p = true;
3416 0 : return t;
3417 : }
3418 :
3419 : /* For __builtin_is_constant_evaluated, defer it if not
3420 : ctx->manifestly_const_eval (as sometimes we try to constant evaluate
3421 : without manifestly_const_eval even expressions or parts thereof which
3422 : will later be manifestly const_eval evaluated), otherwise fold it to
3423 : true. */
3424 0 : if (fndecl_built_in_p (fun, CP_BUILT_IN_IS_CONSTANT_EVALUATED,
3425 : BUILT_IN_FRONTEND))
3426 : {
3427 0 : if (!ctx->manifestly_const_eval)
3428 : {
3429 0 : *non_constant_p = true;
3430 0 : return t;
3431 : }
3432 0 : return boolean_true_node;
3433 : }
3434 :
3435 0 : if (fndecl_built_in_p (fun, CP_BUILT_IN_SOURCE_LOCATION, BUILT_IN_FRONTEND))
3436 : {
3437 0 : temp_override<tree> ovr (current_function_decl);
3438 0 : if (ctx->call && ctx->call->fundef)
3439 0 : current_function_decl = ctx->call->fundef->decl;
3440 0 : return fold_builtin_source_location (EXPR_LOCATION (t));
3441 0 : }
3442 :
3443 0 : int strops = 0;
3444 0 : int strret = 0;
3445 0 : if (fndecl_built_in_p (fun, BUILT_IN_NORMAL))
3446 0 : switch (DECL_FUNCTION_CODE (fun))
3447 : {
3448 : case BUILT_IN_STRLEN:
3449 : case BUILT_IN_STRNLEN:
3450 0 : strops = 1;
3451 : break;
3452 0 : case BUILT_IN_MEMCHR:
3453 0 : case BUILT_IN_STRCHR:
3454 0 : case BUILT_IN_STRRCHR:
3455 0 : strops = 1;
3456 0 : strret = 1;
3457 0 : break;
3458 0 : case BUILT_IN_MEMCMP:
3459 0 : case BUILT_IN_STRCMP:
3460 0 : strops = 2;
3461 0 : break;
3462 0 : case BUILT_IN_STRSTR:
3463 0 : strops = 2;
3464 0 : strret = 1;
3465 0 : break;
3466 0 : case BUILT_IN_ASAN_POINTER_COMPARE:
3467 0 : case BUILT_IN_ASAN_POINTER_SUBTRACT:
3468 : /* These builtins shall be ignored during constant expression
3469 : evaluation. */
3470 0 : return void_node;
3471 : default:
3472 : break;
3473 : }
3474 :
3475 : /* Be permissive for arguments to built-ins; __builtin_constant_p should
3476 : return constant false for a non-constant argument. */
3477 0 : constexpr_ctx new_ctx = *ctx;
3478 0 : new_ctx.quiet = true;
3479 0 : for (i = 0; i < nargs; ++i)
3480 : {
3481 0 : tree arg = CALL_EXPR_ARG (t, i);
3482 0 : tree oarg = arg;
3483 :
3484 : /* To handle string built-ins we need to pass ADDR_EXPR<STRING_CST> since
3485 : expand_builtin doesn't know how to look in the values table. */
3486 0 : bool strop = i < strops;
3487 0 : if (strop)
3488 : {
3489 0 : STRIP_NOPS (arg);
3490 0 : if (TREE_CODE (arg) == ADDR_EXPR)
3491 0 : arg = TREE_OPERAND (arg, 0);
3492 : else
3493 : strop = false;
3494 : }
3495 :
3496 : /* If builtin_valid_in_constant_expr_p is true,
3497 : potential_constant_expression_1 has not recursed into the arguments
3498 : of the builtin, verify it here. */
3499 0 : if (!builtin_valid_in_constant_expr_p (fun)
3500 0 : || potential_constant_expression (arg))
3501 : {
3502 0 : bool dummy1 = false, dummy2 = false;
3503 0 : tree dummy_jump_target = NULL_TREE;
3504 0 : arg = eval_constant_expression (&new_ctx, arg, false, &dummy1,
3505 : &dummy2, &dummy_jump_target);
3506 : }
3507 :
3508 0 : if (bi_const_p)
3509 : /* For __builtin_constant_p, fold all expressions with constant values
3510 : even if they aren't C++ constant-expressions. */
3511 0 : arg = cp_fold_rvalue (arg);
3512 0 : else if (strop)
3513 : {
3514 0 : if (TREE_CODE (arg) == CONSTRUCTOR)
3515 0 : arg = braced_lists_to_strings (TREE_TYPE (arg), arg);
3516 0 : if (TREE_CODE (arg) == STRING_CST)
3517 0 : arg = build_address (arg);
3518 : else
3519 : arg = oarg;
3520 : }
3521 :
3522 0 : args[i] = arg;
3523 : }
3524 :
3525 0 : bool save_ffbcp = force_folding_builtin_constant_p;
3526 0 : force_folding_builtin_constant_p |= ctx->manifestly_const_eval;
3527 0 : tree save_cur_fn = current_function_decl;
3528 : /* Return name of ctx->call->fundef->decl for __builtin_FUNCTION (). */
3529 0 : if (fndecl_built_in_p (fun, BUILT_IN_FUNCTION) && ctx->call
3530 0 : && ctx->call->fundef)
3531 0 : current_function_decl = ctx->call->fundef->decl;
3532 0 : if (fndecl_built_in_p (fun,
3533 : CP_BUILT_IN_IS_POINTER_INTERCONVERTIBLE_WITH_CLASS,
3534 : BUILT_IN_FRONTEND))
3535 : {
3536 0 : location_t loc = EXPR_LOCATION (t);
3537 0 : if (nargs >= 1)
3538 0 : VERIFY_CONSTANT (args[0]);
3539 0 : new_call
3540 0 : = fold_builtin_is_pointer_inverconvertible_with_class (loc, nargs,
3541 : args);
3542 : }
3543 0 : else if (fndecl_built_in_p (fun, CP_BUILT_IN_IS_CORRESPONDING_MEMBER,
3544 : BUILT_IN_FRONTEND))
3545 : {
3546 0 : location_t loc = EXPR_LOCATION (t);
3547 0 : if (nargs >= 2)
3548 : {
3549 0 : VERIFY_CONSTANT (args[0]);
3550 0 : VERIFY_CONSTANT (args[1]);
3551 : }
3552 0 : new_call = fold_builtin_is_corresponding_member (loc, nargs, args);
3553 : }
3554 : else
3555 0 : new_call = fold_builtin_call_array (EXPR_LOCATION (t), TREE_TYPE (t),
3556 0 : CALL_EXPR_FN (t), nargs, args);
3557 0 : current_function_decl = save_cur_fn;
3558 0 : force_folding_builtin_constant_p = save_ffbcp;
3559 0 : if (new_call == NULL)
3560 : {
3561 0 : if (!*non_constant_p && !ctx->quiet)
3562 : {
3563 : /* Do not allow__builtin_unreachable in constexpr function.
3564 : The __builtin_unreachable call with BUILTINS_LOCATION
3565 : comes from cp_maybe_instrument_return. */
3566 0 : if (fndecl_built_in_p (fun, BUILT_IN_UNREACHABLE)
3567 0 : && EXPR_LOCATION (t) == BUILTINS_LOCATION)
3568 0 : error ("%<constexpr%> call flows off the end of the function");
3569 : else
3570 : {
3571 0 : new_call = build_call_array_loc (EXPR_LOCATION (t), TREE_TYPE (t),
3572 0 : CALL_EXPR_FN (t), nargs, args);
3573 0 : error ("%q+E is not a constant expression", new_call);
3574 : }
3575 : }
3576 0 : *non_constant_p = true;
3577 0 : return t;
3578 : }
3579 :
3580 0 : if (!potential_constant_expression (new_call))
3581 : {
3582 0 : if (!*non_constant_p && !ctx->quiet)
3583 0 : error ("%q+E is not a constant expression", new_call);
3584 0 : *non_constant_p = true;
3585 0 : return t;
3586 : }
3587 :
3588 0 : if (strret)
3589 : {
3590 : /* memchr returns a pointer into the first argument, but we replaced the
3591 : argument above with a STRING_CST; put it back it now. */
3592 0 : tree op = CALL_EXPR_ARG (t, strret - 1);
3593 0 : STRIP_NOPS (new_call);
3594 0 : if (TREE_CODE (new_call) == POINTER_PLUS_EXPR)
3595 0 : TREE_OPERAND (new_call, 0) = op;
3596 0 : else if (TREE_CODE (new_call) == ADDR_EXPR)
3597 0 : new_call = op;
3598 : }
3599 :
3600 0 : return eval_constant_expression (&new_ctx, new_call, lval, non_constant_p,
3601 0 : overflow_p, jump_target);
3602 : }
3603 :
3604 : // Subroutine of cxx_eval_constant_expression.
3605 : // Evaluate the call expression tree T in the context of OLD_CALL expression
3606 : // evaluation.
3607 : static tree
3608 2405 : eval_call_expression (const constexpr_ctx *ctx, tree t, bool lval,
3609 : bool *non_constant_p, bool *overflow_p, tree *jump_target)
3610 : {
3611 2405 : location_t loc = EXPR_LOCATION (t);
3612 2405 : tree fun = get_function_named_in_call (t);
3613 2405 : rust_constexpr_call new_call
3614 2405 : = {NULL, NULL, NULL, 0, ctx->manifestly_const_eval};
3615 2405 : int depth_ok;
3616 :
3617 2405 : if (fun == NULL_TREE)
3618 : {
3619 : // return cxx_eval_internal_function (ctx, t, lval,
3620 : // non_constant_p, overflow_p);
3621 0 : rust_unreachable ();
3622 : return error_mark_node;
3623 : }
3624 :
3625 2405 : if (TREE_CODE (fun) != FUNCTION_DECL)
3626 : {
3627 0 : if (!ctx->quiet && !*non_constant_p)
3628 0 : error_at (loc,
3629 : "expression %qE does not designate a %<constexpr%> "
3630 : "function",
3631 : fun);
3632 0 : *non_constant_p = true;
3633 0 : return t;
3634 : }
3635 :
3636 2405 : if (fndecl_built_in_p (fun))
3637 0 : return eval_builtin_function_call (ctx, t, fun, lval, non_constant_p,
3638 0 : overflow_p, jump_target);
3639 :
3640 2405 : bool non_constant_args = false;
3641 2405 : new_call.bindings
3642 2405 : = rs_bind_parameters_in_call (ctx, t, fun, non_constant_p, overflow_p,
3643 : &non_constant_args, jump_target);
3644 :
3645 : /* We build up the bindings list before we know whether we already have this
3646 : call cached. If we don't end up saving these bindings, ggc_free them when
3647 : this function exits. */
3648 2405 : class free_bindings
3649 : {
3650 : tree *bindings;
3651 :
3652 : public:
3653 2405 : free_bindings (tree &b) : bindings (&b) {}
3654 2405 : ~free_bindings ()
3655 : {
3656 2405 : if (bindings)
3657 0 : ggc_free (*bindings);
3658 2405 : }
3659 2405 : void preserve () { bindings = NULL; }
3660 2405 : } fb (new_call.bindings);
3661 :
3662 2405 : if (*non_constant_p)
3663 : return t;
3664 :
3665 : /* If in direct recursive call, optimize definition search. */
3666 2405 : if (ctx && ctx->call && ctx->call->fundef && ctx->call->fundef->decl == fun)
3667 0 : new_call.fundef = ctx->call->fundef;
3668 : else
3669 : {
3670 2405 : new_call.fundef = retrieve_constexpr_fundef (fun);
3671 2405 : if (new_call.fundef == NULL || new_call.fundef->body == NULL
3672 2405 : || new_call.fundef->result == error_mark_node
3673 2405 : || fun == current_function_decl)
3674 : {
3675 0 : if (!ctx->quiet)
3676 : {
3677 : /* We need to check for current_function_decl here in case we're
3678 : being called during cp_fold_function, because at that point
3679 : DECL_INITIAL is set properly and we have a fundef but we
3680 : haven't lowered invisirefs yet (c++/70344). */
3681 0 : if (DECL_INITIAL (fun) == error_mark_node
3682 0 : || fun == current_function_decl)
3683 0 : error_at (loc,
3684 : "%qD called in a constant expression before its "
3685 : "definition is complete",
3686 : fun);
3687 0 : else if (DECL_INITIAL (fun))
3688 : {
3689 : // /* The definition of fun was somehow unsuitable. But
3690 : // pretend
3691 : // that lambda static thunks don't exist. */
3692 : // if (!lambda_static_thunk_p (fun))
3693 : // error_at (loc, "%qD called in a constant expression",
3694 : // fun);
3695 0 : explain_invalid_constexpr_fn (fun);
3696 : }
3697 : else
3698 0 : error_at (loc, "%qD used before its definition", fun);
3699 : }
3700 0 : *non_constant_p = true;
3701 0 : return t;
3702 : }
3703 : }
3704 :
3705 2405 : depth_ok = push_cx_call_context (t);
3706 :
3707 2405 : tree result = NULL_TREE;
3708 2405 : rust_constexpr_call *entry = NULL;
3709 2405 : if (depth_ok && !non_constant_args && ctx->strict)
3710 : {
3711 2405 : new_call.hash = rust_constexpr_fundef_hasher::hash (new_call.fundef);
3712 2405 : new_call.hash = iterative_hash_object (new_call.bindings, new_call.hash);
3713 2405 : new_call.hash
3714 2405 : = iterative_hash_object (ctx->manifestly_const_eval, new_call.hash);
3715 :
3716 : /* If we have seen this call before, we are done. */
3717 2405 : maybe_initialize_constexpr_call_table ();
3718 2405 : rust_constexpr_call **slot
3719 2405 : = constexpr_call_table->find_slot (&new_call, INSERT);
3720 2405 : entry = *slot;
3721 2405 : if (entry == NULL)
3722 : {
3723 : /* Only cache up to constexpr_cache_depth to limit memory use. */
3724 2405 : if (depth_ok < constexpr_cache_depth)
3725 : {
3726 : /* We need to keep a pointer to the entry, not just the slot, as
3727 : the slot can move during evaluation of the body. */
3728 2405 : *slot = entry = ggc_alloc<rust_constexpr_call> ();
3729 2405 : *entry = new_call;
3730 2405 : fb.preserve ();
3731 : }
3732 : }
3733 : /* Calls that are in progress have their result set to NULL, so that we
3734 : can detect circular dependencies. Now that we only cache up to
3735 : constexpr_cache_depth this won't catch circular dependencies that
3736 : start deeper, but they'll hit the recursion or ops limit. */
3737 0 : else if (entry->result == NULL)
3738 : {
3739 0 : if (!ctx->quiet)
3740 0 : error ("call has circular dependency");
3741 0 : *non_constant_p = true;
3742 0 : entry->result = result = error_mark_node;
3743 : }
3744 : else
3745 : result = entry->result;
3746 : }
3747 :
3748 2405 : if (!depth_ok)
3749 : {
3750 0 : if (!ctx->quiet)
3751 0 : error ("%<constexpr%> evaluation depth exceeds maximum of %d (use "
3752 : "%<-fconstexpr-depth=%> to increase the maximum)",
3753 : max_constexpr_depth);
3754 0 : *non_constant_p = true;
3755 0 : result = error_mark_node;
3756 : }
3757 : else
3758 : {
3759 2405 : bool cacheable = true;
3760 2405 : if (result && result != error_mark_node)
3761 : /* OK */;
3762 2405 : else if (!DECL_SAVED_TREE (fun))
3763 : {
3764 : /* When at_eof >= 2, cgraph has started throwing away
3765 : DECL_SAVED_TREE, so fail quietly. FIXME we get here because of
3766 : late code generation for VEC_INIT_EXPR, which needs to be
3767 : completely reconsidered. */
3768 : // gcc_assert (at_eof >= 2 && ctx->quiet);
3769 0 : *non_constant_p = true;
3770 : }
3771 2405 : else if (tree copy = get_fundef_copy (new_call.fundef))
3772 : {
3773 2405 : tree body, parms, res;
3774 2405 : releasing_vec ctors;
3775 :
3776 : /* Reuse or create a new unshared copy of this function's body. */
3777 2405 : body = TREE_PURPOSE (copy);
3778 2405 : parms = TREE_VALUE (copy);
3779 2405 : res = TREE_TYPE (copy);
3780 :
3781 : /* Associate the bindings with the remapped parms. */
3782 2405 : tree bound = new_call.bindings;
3783 2405 : tree remapped = parms;
3784 2421 : for (int i = 0; i < TREE_VEC_LENGTH (bound); ++i)
3785 : {
3786 16 : tree arg = TREE_VEC_ELT (bound, i);
3787 16 : if (entry)
3788 : {
3789 : /* Unshare args going into the hash table to separate them
3790 : from the caller's context, for better GC and to avoid
3791 : problems with verify_gimple. */
3792 16 : arg = unshare_expr_without_location (arg);
3793 16 : TREE_VEC_ELT (bound, i) = arg;
3794 :
3795 : /* And then unshare again so the callee doesn't change the
3796 : argument values in the hash table. XXX Could we unshare
3797 : lazily in cxx_eval_store_expression? */
3798 16 : arg = unshare_constructor (arg);
3799 16 : if (TREE_CODE (arg) == CONSTRUCTOR)
3800 1 : vec_safe_push (ctors, arg);
3801 : }
3802 :
3803 16 : ctx->global->values.put (remapped, arg);
3804 16 : remapped = DECL_CHAIN (remapped);
3805 : }
3806 : /* Add the RESULT_DECL to the values map, too. */
3807 2405 : gcc_assert (!DECL_BY_REFERENCE (res));
3808 2405 : ctx->global->values.put (res, NULL_TREE);
3809 :
3810 : /* Track the callee's evaluated SAVE_EXPRs and TARGET_EXPRs so that
3811 : we can forget their values after the call. */
3812 2405 : constexpr_ctx ctx_with_save_exprs = *ctx;
3813 2405 : auto_vec<tree, 10> save_exprs;
3814 2405 : ctx_with_save_exprs.save_exprs = &save_exprs;
3815 2405 : ctx_with_save_exprs.call = &new_call;
3816 2405 : unsigned save_heap_alloc_count = ctx->global->heap_vars.length ();
3817 2405 : unsigned save_heap_dealloc_count = ctx->global->heap_dealloc_count;
3818 :
3819 2405 : tree jump_target = NULL_TREE;
3820 2405 : eval_constant_expression (&ctx_with_save_exprs, body, lval,
3821 : non_constant_p, overflow_p, &jump_target);
3822 :
3823 2405 : if (VOID_TYPE_P (TREE_TYPE (res)))
3824 0 : result = void_node;
3825 : else
3826 : {
3827 2405 : result = *ctx->global->values.get (res);
3828 2405 : if (result == NULL_TREE && !*non_constant_p)
3829 : {
3830 8 : *non_constant_p = true;
3831 : }
3832 : }
3833 :
3834 : /* Forget the saved values of the callee's SAVE_EXPRs and
3835 : TARGET_EXPRs. */
3836 7215 : for (tree save_expr : save_exprs)
3837 0 : ctx->global->values.remove (save_expr);
3838 :
3839 : /* Remove the parms/result from the values map. Is it worth
3840 : bothering to do this when the map itself is only live for
3841 : one constexpr evaluation? If so, maybe also clear out
3842 : other vars from call, maybe in BIND_EXPR handling? */
3843 2405 : ctx->global->values.remove (res);
3844 2421 : for (tree parm = parms; parm; parm = TREE_CHAIN (parm))
3845 16 : ctx->global->values.remove (parm);
3846 :
3847 : /* Make the unshared function copy we used available for re-use. */
3848 2405 : save_fundef_copy (fun, copy);
3849 :
3850 : /* If the call allocated some heap object that hasn't been
3851 : deallocated during the call, or if it deallocated some heap
3852 : object it has not allocated, the call isn't really stateless
3853 : for the constexpr evaluation and should not be cached.
3854 : It is fine if the call allocates something and deallocates it
3855 : too. */
3856 2405 : if (entry
3857 4810 : && (save_heap_alloc_count != ctx->global->heap_vars.length ()
3858 2405 : || (save_heap_dealloc_count
3859 2405 : != ctx->global->heap_dealloc_count)))
3860 : {
3861 0 : tree heap_var;
3862 0 : unsigned int i;
3863 0 : if ((ctx->global->heap_vars.length ()
3864 0 : - ctx->global->heap_dealloc_count)
3865 0 : != save_heap_alloc_count - save_heap_dealloc_count)
3866 : cacheable = false;
3867 : else
3868 2405 : FOR_EACH_VEC_ELT_FROM (ctx->global->heap_vars, i, heap_var,
3869 : save_heap_alloc_count)
3870 0 : if (DECL_NAME (heap_var) != heap_deleted_identifier)
3871 : {
3872 : cacheable = false;
3873 : break;
3874 : }
3875 : }
3876 2405 : }
3877 : else
3878 : /* Couldn't get a function copy to evaluate. */
3879 0 : *non_constant_p = true;
3880 :
3881 2405 : if (result == error_mark_node)
3882 0 : *non_constant_p = true;
3883 2405 : if (*non_constant_p || *overflow_p)
3884 : result = error_mark_node;
3885 2380 : else if (!result)
3886 0 : result = void_node;
3887 2405 : if (entry)
3888 2405 : entry->result = cacheable ? result : error_mark_node;
3889 : }
3890 :
3891 2405 : pop_cx_call_context ();
3892 2405 : return result;
3893 2405 : }
3894 :
3895 : /* Subroutine of build_data_member_initialization. MEMBER is a COMPONENT_REF
3896 : for a member of an anonymous aggregate, INIT is the initializer for that
3897 : member, and VEC_OUTER is the vector of constructor elements for the class
3898 : whose constructor we are processing. Add the initializer to the vector
3899 : and return true to indicate success. */
3900 :
3901 : // static bool
3902 : // build_anon_member_initialization (tree member, tree init,
3903 : // vec<constructor_elt, va_gc> **vec_outer)
3904 : // {
3905 : // /* MEMBER presents the relevant fields from the inside out, but we need
3906 : // to build up the initializer from the outside in so that we can reuse
3907 : // previously built CONSTRUCTORs if this is, say, the second field in an
3908 : // anonymous struct. So we use a vec as a stack. */
3909 : // auto_vec<tree, 2> fields;
3910 : // do
3911 : // {
3912 : // fields.safe_push (TREE_OPERAND (member, 1));
3913 : // member = TREE_OPERAND (member, 0);
3914 : // } while (ANON_AGGR_TYPE_P (TREE_TYPE (member))
3915 : // && TREE_CODE (member) == COMPONENT_REF);
3916 : //
3917 : // /* VEC has the constructor elements vector for the context of FIELD.
3918 : // If FIELD is an anonymous aggregate, we will push inside it. */
3919 : // vec<constructor_elt, va_gc> **vec = vec_outer;
3920 : // tree field;
3921 : // while (field = fields.pop (), ANON_AGGR_TYPE_P (TREE_TYPE (field)))
3922 : // {
3923 : // tree ctor;
3924 : // /* If there is already an outer constructor entry for the anonymous
3925 : // aggregate FIELD, use it; otherwise, insert one. */
3926 : // if (vec_safe_is_empty (*vec) || (*vec)->last ().index != field)
3927 : // {
3928 : // ctor = build_constructor (TREE_TYPE (field), NULL);
3929 : // CONSTRUCTOR_APPEND_ELT (*vec, field, ctor);
3930 : // }
3931 : // else
3932 : // ctor = (*vec)->last ().value;
3933 : // vec = &CONSTRUCTOR_ELTS (ctor);
3934 : // }
3935 : //
3936 : // /* Now we're at the innermost field, the one that isn't an anonymous
3937 : // aggregate. Add its initializer to the CONSTRUCTOR and we're done. */
3938 : // gcc_assert (fields.is_empty ());
3939 : // CONSTRUCTOR_APPEND_ELT (*vec, field, init);
3940 : //
3941 : // return true;
3942 : // }
3943 :
3944 : ///* V is a vector of constructor elements built up for the base and member
3945 : // initializers of a constructor for TYPE. They need to be in increasing
3946 : // offset order, which they might not be yet if TYPE has a primary base
3947 : // which is not first in the base-clause or a vptr and at least one base
3948 : // all of which are non-primary. */
3949 : //
3950 : // static vec<constructor_elt, va_gc> *
3951 : // sort_constexpr_mem_initializers (tree type, vec<constructor_elt, va_gc> *v)
3952 : //{
3953 : // tree pri = CLASSTYPE_PRIMARY_BINFO (type);
3954 : // tree field_type;
3955 : // unsigned i;
3956 : // constructor_elt *ce;
3957 : //
3958 : // if (pri)
3959 : // field_type = BINFO_TYPE (pri);
3960 : // else if (TYPE_CONTAINS_VPTR_P (type))
3961 : // field_type = vtbl_ptr_type_node;
3962 : // else
3963 : // return v;
3964 : //
3965 : // /* Find the element for the primary base or vptr and move it to the
3966 : // beginning of the vec. */
3967 : // for (i = 0; vec_safe_iterate (v, i, &ce); ++i)
3968 : // if (TREE_TYPE (ce->index) == field_type)
3969 : // break;
3970 : //
3971 : // if (i > 0 && i < vec_safe_length (v))
3972 : // {
3973 : // vec<constructor_elt, va_gc> &vref = *v;
3974 : // constructor_elt elt = vref[i];
3975 : // for (; i > 0; --i)
3976 : // vref[i] = vref[i - 1];
3977 : // vref[0] = elt;
3978 : // }
3979 : //
3980 : // return v;
3981 : //}
3982 :
3983 : /* Subroutine of build_constexpr_constructor_member_initializers.
3984 : The expression tree T represents a data member initialization
3985 : in a (constexpr) constructor definition. Build a pairing of
3986 : the data member with its initializer, and prepend that pair
3987 : to the existing initialization pair INITS. */
3988 :
3989 : static bool
3990 0 : build_data_member_initialization (tree t, vec<constructor_elt, va_gc> **vec)
3991 : {
3992 0 : tree member;
3993 0 : if (TREE_CODE (t) == CLEANUP_POINT_EXPR)
3994 0 : t = TREE_OPERAND (t, 0);
3995 0 : if (TREE_CODE (t) == EXPR_STMT)
3996 0 : t = TREE_OPERAND (t, 0);
3997 0 : if (t == error_mark_node)
3998 : return false;
3999 0 : if (TREE_CODE (t) == STATEMENT_LIST)
4000 : {
4001 0 : for (tree stmt : tsi_range (t))
4002 0 : if (!build_data_member_initialization (stmt, vec))
4003 0 : return false;
4004 : return true;
4005 : }
4006 0 : if (TREE_CODE (t) == CONVERT_EXPR)
4007 0 : t = TREE_OPERAND (t, 0);
4008 0 : if (TREE_CODE (t) == INIT_EXPR
4009 : /* vptr initialization shows up as a MODIFY_EXPR. In C++14 we only
4010 : use what this function builds for cx_check_missing_mem_inits, and
4011 : assignment in the ctor body doesn't count. */
4012 0 : || (TREE_CODE (t) == MODIFY_EXPR))
4013 : {
4014 0 : member = TREE_OPERAND (t, 0);
4015 : // Faisal: not sure if we need to port over break_out_target_exprs
4016 : // if not, then not sure how to handle init in this case
4017 : // init = break_out_target_exprs (TREE_OPERAND (t, 1));
4018 : }
4019 0 : else if (TREE_CODE (t) == CALL_EXPR)
4020 : {
4021 0 : tree fn = get_callee_fndecl (t);
4022 0 : if (!fn || !DECL_CONSTRUCTOR_P (fn))
4023 : /* We're only interested in calls to subobject constructors. */
4024 : return true;
4025 0 : member = CALL_EXPR_ARG (t, 0);
4026 : /* We don't use build_cplus_new here because it complains about
4027 : abstract bases. Leaving the call unwrapped means that it has the
4028 : wrong type, but cxx_eval_constant_expression doesn't care. */
4029 : // Faisal: not sure if we need to port over break_out_target_exprs
4030 : // if not, then not sure how to handle init in this case
4031 : // init = break_out_target_exprs (t);
4032 : }
4033 0 : else if (TREE_CODE (t) == BIND_EXPR)
4034 0 : return build_data_member_initialization (BIND_EXPR_BODY (t), vec);
4035 : else
4036 : /* Don't add anything else to the CONSTRUCTOR. */
4037 : return true;
4038 0 : if (INDIRECT_REF_P (member))
4039 0 : member = TREE_OPERAND (member, 0);
4040 0 : if (TREE_CODE (member) == NOP_EXPR)
4041 : {
4042 0 : tree op = member;
4043 0 : STRIP_NOPS (op);
4044 0 : if (TREE_CODE (op) == ADDR_EXPR)
4045 : {
4046 0 : gcc_assert (same_type_ignoring_top_level_qualifiers_p (
4047 : TREE_TYPE (TREE_TYPE (op)), TREE_TYPE (TREE_TYPE (member))));
4048 : /* Initializing a cv-qualified member; we need to look through
4049 : the const_cast. */
4050 : member = op;
4051 : }
4052 0 : else if (op == current_class_ptr
4053 0 : && (same_type_ignoring_top_level_qualifiers_p (
4054 0 : TREE_TYPE (TREE_TYPE (member)), current_class_type)))
4055 : /* Delegating constructor. */
4056 : member = op;
4057 : else
4058 : {
4059 : /* This is an initializer for an empty base; keep it for now so
4060 : we can check it in cxx_eval_bare_aggregate. */
4061 0 : gcc_assert (is_empty_class (TREE_TYPE (TREE_TYPE (member))));
4062 : }
4063 : }
4064 0 : if (TREE_CODE (member) == ADDR_EXPR)
4065 0 : member = TREE_OPERAND (member, 0);
4066 0 : if (TREE_CODE (member) == COMPONENT_REF)
4067 : {
4068 0 : tree aggr = TREE_OPERAND (member, 0);
4069 0 : if (TREE_CODE (aggr) == VAR_DECL)
4070 : /* Initializing a local variable, don't add anything. */
4071 : return true;
4072 0 : if (TREE_CODE (aggr) != COMPONENT_REF)
4073 : /* Normal member initialization. */
4074 0 : member = TREE_OPERAND (member, 1);
4075 0 : else if (ANON_AGGR_TYPE_P (TREE_TYPE (aggr)))
4076 : /* Initializing a member of an anonymous union. */
4077 0 : rust_sorry_at (UNDEF_LOCATION,
4078 : "cannot handle value initialization yet");
4079 : // return build_anon_member_initialization (member, init, vec);
4080 : else
4081 : /* We're initializing a vtable pointer in a base. Leave it as
4082 : COMPONENT_REF so we remember the path to get to the vfield. */
4083 0 : gcc_assert (TREE_TYPE (member) == vtbl_ptr_type_node);
4084 : }
4085 :
4086 : /* Value-initialization can produce multiple initializers for the
4087 : same field; use the last one. */
4088 0 : if (!vec_safe_is_empty (*vec) && (*vec)->last ().index == member)
4089 0 : rust_sorry_at (UNDEF_LOCATION, "cannot handle value initialization yet");
4090 : // (*vec)->last ().value = init;
4091 : else
4092 0 : rust_sorry_at (UNDEF_LOCATION, "cannot handle value initialization yet");
4093 : // CONSTRUCTOR_APPEND_ELT (*vec, member, init);
4094 : return true;
4095 : }
4096 :
4097 : ///* Build compile-time evalable representations of member-initializer list
4098 : // for a constexpr constructor. */
4099 : //
4100 : // static tree
4101 : // build_constexpr_constructor_member_initializers (tree type, tree body)
4102 : //{
4103 : // vec<constructor_elt, va_gc> *vec = NULL;
4104 : // bool ok = true;
4105 : // while (true)
4106 : // switch (TREE_CODE (body))
4107 : // {
4108 : // case STATEMENT_LIST:
4109 : // for (tree stmt : tsi_range (body))
4110 : // {
4111 : // body = stmt;
4112 : // if (TREE_CODE (body) == BIND_EXPR)
4113 : // break;
4114 : // }
4115 : // break;
4116 : //
4117 : // case BIND_EXPR:
4118 : // body = BIND_EXPR_BODY (body);
4119 : // goto found;
4120 : //
4121 : // default:
4122 : // rust_unreachable ();
4123 : // }
4124 : // found:
4125 : //
4126 : // if (TREE_CODE (body) == CLEANUP_POINT_EXPR)
4127 : // {
4128 : // body = TREE_OPERAND (body, 0);
4129 : // if (TREE_CODE (body) == EXPR_STMT)
4130 : // body = TREE_OPERAND (body, 0);
4131 : // if (TREE_CODE (body) == INIT_EXPR
4132 : // && (same_type_ignoring_top_level_qualifiers_p (
4133 : // TREE_TYPE (TREE_OPERAND (body, 0)), current_class_type)))
4134 : // {
4135 : // /* Trivial copy. */
4136 : // return TREE_OPERAND (body, 1);
4137 : // }
4138 : // ok = build_data_member_initialization (body, &vec);
4139 : // }
4140 : // else if (TREE_CODE (body) == STATEMENT_LIST)
4141 : // {
4142 : // for (tree stmt : tsi_range (body))
4143 : // {
4144 : // ok = build_data_member_initialization (stmt, &vec);
4145 : // if (!ok)
4146 : // break;
4147 : // }
4148 : // }
4149 : // else if (EXPR_P (body))
4150 : // ok = build_data_member_initialization (body, &vec);
4151 : // else
4152 : // gcc_assert (errorcount > 0);
4153 : // if (ok)
4154 : // {
4155 : // if (vec_safe_length (vec) > 0)
4156 : // {
4157 : // /* In a delegating constructor, return the target. */
4158 : // constructor_elt *ce = &(*vec)[0];
4159 : // if (ce->index == current_class_ptr)
4160 : // {
4161 : // body = ce->value;
4162 : // vec_free (vec);
4163 : // return body;
4164 : // }
4165 : // }
4166 : // vec = sort_constexpr_mem_initializers (type, vec);
4167 : // return build_constructor (type, vec);
4168 : // }
4169 : // else
4170 : // return error_mark_node;
4171 : //}
4172 :
4173 : // Subroutine of check_constexpr_fundef. BODY is the body of a function
4174 : // declared to be constexpr, or a sub-statement thereof. Returns the
4175 : // return value if suitable, error_mark_node for a statement not allowed in
4176 : // a constexpr function, or NULL_TREE if no return value was found.
4177 : static tree
4178 0 : constexpr_fn_retval (const constexpr_ctx *ctx, tree body)
4179 : {
4180 0 : switch (TREE_CODE (body))
4181 : {
4182 0 : case STATEMENT_LIST:
4183 0 : {
4184 0 : tree expr = NULL_TREE;
4185 0 : for (tree stmt : tsi_range (body))
4186 : {
4187 0 : tree s = constexpr_fn_retval (ctx, stmt);
4188 0 : if (s == error_mark_node)
4189 : return error_mark_node;
4190 0 : else if (s == NULL_TREE)
4191 : /* Keep iterating. */;
4192 0 : else if (expr)
4193 : /* Multiple return statements. */
4194 : return error_mark_node;
4195 : else
4196 : expr = s;
4197 : }
4198 : return expr;
4199 : }
4200 :
4201 0 : case RETURN_EXPR:
4202 0 : {
4203 0 : bool non_constant_p = false;
4204 0 : bool overflow_p = false;
4205 0 : return eval_constant_expression (ctx, body, false, &non_constant_p,
4206 : &overflow_p, NULL);
4207 : }
4208 0 : case DECL_EXPR:
4209 0 : {
4210 0 : tree decl = DECL_EXPR_DECL (body);
4211 0 : if (TREE_CODE (decl) == USING_DECL
4212 : /* Accept __func__, __FUNCTION__, and __PRETTY_FUNCTION__. */
4213 0 : || DECL_ARTIFICIAL (decl))
4214 : return NULL_TREE;
4215 0 : return error_mark_node;
4216 : }
4217 :
4218 0 : case CLEANUP_POINT_EXPR:
4219 0 : return constexpr_fn_retval (ctx, TREE_OPERAND (body, 0));
4220 :
4221 0 : case BIND_EXPR:
4222 0 : {
4223 0 : tree b = BIND_EXPR_BODY (body);
4224 0 : return constexpr_fn_retval (ctx, b);
4225 : }
4226 0 : break;
4227 :
4228 0 : default:
4229 0 : return error_mark_node;
4230 : }
4231 : return error_mark_node;
4232 : }
4233 :
4234 : // Taken from cp/constexpr.cc
4235 : //
4236 : // If DECL is a scalar enumeration constant or variable with a
4237 : // constant initializer, return the initializer (or, its initializers,
4238 : // recursively); otherwise, return DECL. If STRICT_P, the
4239 : // initializer is only returned if DECL is a
4240 : // constant-expression. If RETURN_AGGREGATE_CST_OK_P, it is ok to
4241 : // return an aggregate constant. If UNSHARE_P, return an unshared
4242 : // copy of the initializer.
4243 : static tree
4244 1464 : constant_value_1 (tree decl, bool, bool, bool unshare_p)
4245 : {
4246 2926 : while (TREE_CODE (decl) == CONST_DECL)
4247 : {
4248 1462 : tree init;
4249 : /* If DECL is a static data member in a template
4250 : specialization, we must instantiate it here. The
4251 : initializer for the static data member is not processed
4252 : until needed; we need it now. */
4253 :
4254 1462 : init = DECL_INITIAL (decl);
4255 1462 : if (init == error_mark_node)
4256 : {
4257 : if (TREE_CODE (decl) == CONST_DECL)
4258 : /* Treat the error as a constant to avoid cascading errors on
4259 : excessively recursive template instantiation (c++/9335). */
4260 : return init;
4261 : else
4262 : return decl;
4263 : }
4264 :
4265 : decl = init;
4266 : }
4267 1464 : return unshare_p ? unshare_expr (decl) : decl;
4268 : }
4269 :
4270 : /* Like scalar_constant_value, but can also return aggregate initializers.
4271 : If UNSHARE_P, return an unshared copy of the initializer. */
4272 :
4273 : tree
4274 1464 : decl_really_constant_value (tree decl, bool unshare_p /*= true*/)
4275 : {
4276 1464 : return constant_value_1 (decl, /*strict_p=*/true,
4277 : /*return_aggregate_cst_ok_p=*/true,
4278 0 : /*unshare_p=*/unshare_p);
4279 : }
4280 :
4281 : // A more relaxed version of decl_really_constant_value, used by the
4282 : // common C/C++ code.
4283 : tree
4284 0 : decl_constant_value (tree decl, bool unshare_p)
4285 : {
4286 0 : return constant_value_1 (decl, /*strict_p=*/false,
4287 : /*return_aggregate_cst_ok_p=*/true,
4288 0 : /*unshare_p=*/unshare_p);
4289 : }
4290 :
4291 : static void
4292 2 : non_const_var_error (location_t loc, tree r)
4293 : {
4294 2 : tree type = TREE_TYPE (r);
4295 :
4296 : /* Avoid error cascade. */
4297 2 : if (DECL_INITIAL (r) == error_mark_node)
4298 : return;
4299 2 : if (DECL_DECLARED_CONSTEXPR_P (r))
4300 0 : inform (DECL_SOURCE_LOCATION (r), "%qD used in its own initializer", r);
4301 2 : else if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
4302 : {
4303 2 : if (!DECL_INITIAL (r) || !TREE_CONSTANT (DECL_INITIAL (r))
4304 2 : || !DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r))
4305 2 : inform (DECL_SOURCE_LOCATION (r),
4306 : "%qD was not initialized with a constant "
4307 : "expression",
4308 : r);
4309 : else
4310 0 : gcc_unreachable ();
4311 : }
4312 0 : else if (TYPE_REF_P (type))
4313 0 : inform (DECL_SOURCE_LOCATION (r),
4314 : "%qD was not initialized with a constant "
4315 : "expression",
4316 : r);
4317 : else
4318 : {
4319 0 : if (!DECL_DECLARED_CONSTEXPR_P (r))
4320 0 : inform (DECL_SOURCE_LOCATION (r), "%qD was not declared %<constexpr%>",
4321 : r);
4322 : else
4323 0 : inform (DECL_SOURCE_LOCATION (r),
4324 : "%qD does not have integral or enumeration type", r);
4325 : }
4326 : }
4327 :
4328 : static tree
4329 2408 : get_callee (tree call)
4330 : {
4331 2408 : if (call == NULL_TREE)
4332 : return call;
4333 2408 : else if (TREE_CODE (call) == CALL_EXPR)
4334 2408 : return CALL_EXPR_FN (call);
4335 :
4336 : return NULL_TREE;
4337 : }
4338 :
4339 : // We have an expression tree T that represents a call, either CALL_EXPR
4340 : // or AGGR_INIT_EXPR. If the call is lexically to a named function,
4341 : // return the _DECL for that function.
4342 : static tree
4343 2408 : get_function_named_in_call (tree t)
4344 : {
4345 2408 : tree fun = get_callee (t);
4346 2408 : if (fun && TREE_CODE (fun) == ADDR_EXPR
4347 2866 : && TREE_CODE (TREE_OPERAND (fun, 0)) == FUNCTION_DECL)
4348 458 : fun = TREE_OPERAND (fun, 0);
4349 2408 : return fun;
4350 : }
4351 :
4352 : // forked from gcc/cp/constexpr.cc maybe_constexpr_fn
4353 :
4354 : /* True if a function might be declared constexpr */
4355 :
4356 : bool
4357 0 : maybe_constexpr_fn (tree t)
4358 : {
4359 0 : return (DECL_DECLARED_CONSTEXPR_P (t));
4360 : }
4361 :
4362 : // forked from gcc/cp/constexpr.cc var_in_maybe_constexpr_fn
4363 :
4364 : /* True if T was declared in a function that might be constexpr: either a
4365 : function that was declared constexpr. */
4366 :
4367 : bool
4368 0 : var_in_maybe_constexpr_fn (tree t)
4369 : {
4370 0 : return (DECL_FUNCTION_SCOPE_P (t) && maybe_constexpr_fn (DECL_CONTEXT (t)));
4371 : }
4372 :
4373 : /* P0859: A function is needed for constant evaluation if it is a constexpr
4374 : function that is named by an expression ([basic.def.odr]) that is
4375 : potentially constant evaluated.
4376 :
4377 : So we need to instantiate any constexpr functions mentioned by the
4378 : expression even if the definition isn't needed for evaluating the
4379 : expression. */
4380 :
4381 : static tree
4382 0 : instantiate_cx_fn_r (tree *tp, int *walk_subtrees, void * /*data*/)
4383 : {
4384 0 : if (TREE_CODE (*tp) == CALL_EXPR)
4385 : {
4386 0 : if (EXPR_HAS_LOCATION (*tp))
4387 0 : input_location = EXPR_LOCATION (*tp);
4388 : }
4389 :
4390 0 : if (!EXPR_P (*tp))
4391 0 : *walk_subtrees = 0;
4392 :
4393 0 : return NULL_TREE;
4394 : }
4395 :
4396 : static void
4397 0 : instantiate_constexpr_fns (tree t)
4398 : {
4399 0 : location_t loc = input_location;
4400 0 : rs_walk_tree_without_duplicates (&t, instantiate_cx_fn_r, NULL);
4401 0 : input_location = loc;
4402 0 : }
4403 :
4404 : /* Returns less than, equal to, or greater than zero if KEY is found to be
4405 : less than, to match, or to be greater than the constructor_elt's INDEX. */
4406 :
4407 : static int
4408 0 : array_index_cmp (tree key, tree index)
4409 : {
4410 0 : gcc_assert (TREE_CODE (key) == INTEGER_CST);
4411 :
4412 0 : switch (TREE_CODE (index))
4413 : {
4414 0 : case INTEGER_CST:
4415 0 : return tree_int_cst_compare (key, index);
4416 0 : case RANGE_EXPR:
4417 0 : {
4418 0 : tree lo = TREE_OPERAND (index, 0);
4419 0 : tree hi = TREE_OPERAND (index, 1);
4420 0 : if (tree_int_cst_lt (key, lo))
4421 : return -1;
4422 0 : else if (tree_int_cst_lt (hi, key))
4423 : return 1;
4424 : else
4425 0 : return 0;
4426 : }
4427 0 : default:
4428 0 : rust_unreachable ();
4429 : }
4430 : }
4431 :
4432 : /* If T is a CONSTRUCTOR, return an unshared copy of T and any
4433 : sub-CONSTRUCTORs. Otherwise return T.
4434 :
4435 : We use this whenever we initialize an object as a whole, whether it's a
4436 : parameter, a local variable, or a subobject, so that subsequent
4437 : modifications don't affect other places where it was used. */
4438 :
4439 : tree
4440 2545 : unshare_constructor (tree t MEM_STAT_DECL)
4441 : {
4442 2545 : if (!t || TREE_CODE (t) != CONSTRUCTOR)
4443 : return t;
4444 81 : auto_vec<tree *, 4> ptrs;
4445 81 : ptrs.safe_push (&t);
4446 81 : while (!ptrs.is_empty ())
4447 : {
4448 88 : tree *p = ptrs.pop ();
4449 88 : tree n = copy_node (*p PASS_MEM_STAT);
4450 176 : CONSTRUCTOR_ELTS (n)
4451 162 : = vec_safe_copy (CONSTRUCTOR_ELTS (*p) PASS_MEM_STAT);
4452 88 : *p = n;
4453 88 : vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (n);
4454 88 : constructor_elt *ce;
4455 673 : for (HOST_WIDE_INT i = 0; vec_safe_iterate (v, i, &ce); ++i)
4456 416 : if (ce->value && TREE_CODE (ce->value) == CONSTRUCTOR)
4457 7 : ptrs.safe_push (&ce->value);
4458 : }
4459 81 : return t;
4460 81 : }
4461 :
4462 : /* Returns the index of the constructor_elt of ARY which matches DINDEX, or -1
4463 : if none. If INSERT is true, insert a matching element rather than fail. */
4464 :
4465 : static HOST_WIDE_INT
4466 10 : find_array_ctor_elt (tree ary, tree dindex, bool insert)
4467 : {
4468 10 : if (tree_int_cst_sgn (dindex) < 0)
4469 : return -1;
4470 :
4471 10 : unsigned HOST_WIDE_INT i = tree_to_uhwi (dindex);
4472 10 : vec<constructor_elt, va_gc> *elts = CONSTRUCTOR_ELTS (ary);
4473 10 : unsigned HOST_WIDE_INT len = vec_safe_length (elts);
4474 :
4475 11 : unsigned HOST_WIDE_INT end = len;
4476 10 : unsigned HOST_WIDE_INT begin = 0;
4477 :
4478 : /* If the last element of the CONSTRUCTOR has its own index, we can assume
4479 : that the same is true of the other elements and index directly. */
4480 10 : if (end > 0)
4481 : {
4482 9 : tree cindex = (*elts)[end - 1].index;
4483 9 : if (cindex == NULL_TREE)
4484 : {
4485 : /* Verify that if the last index is missing, all indexes
4486 : are missing. */
4487 0 : if (flag_checking)
4488 0 : for (unsigned int j = 0; j < len - 1; ++j)
4489 0 : gcc_assert ((*elts)[j].index == NULL_TREE);
4490 0 : if (i < end)
4491 0 : return i;
4492 : else
4493 : {
4494 0 : begin = end;
4495 0 : if (i == end)
4496 : /* If the element is to be added right at the end,
4497 : make sure it is added with cleared index too. */
4498 1 : dindex = NULL_TREE;
4499 0 : else if (insert)
4500 : /* Otherwise, in order not to break the assumption
4501 : that CONSTRUCTOR either has all indexes or none,
4502 : we need to add indexes to all elements. */
4503 0 : for (unsigned int j = 0; j < len; ++j)
4504 0 : (*elts)[j].index = build_int_cst (TREE_TYPE (dindex), j);
4505 : }
4506 : }
4507 9 : else if (TREE_CODE (cindex) == INTEGER_CST
4508 9 : && compare_tree_int (cindex, end - 1) == 0)
4509 : {
4510 9 : if (i < end)
4511 9 : return i;
4512 : else
4513 1 : begin = end;
4514 : }
4515 : }
4516 :
4517 : /* Otherwise, find a matching index by means of a binary search. */
4518 1 : while (begin != end)
4519 : {
4520 0 : unsigned HOST_WIDE_INT middle = (begin + end) / 2;
4521 0 : constructor_elt &elt = (*elts)[middle];
4522 0 : tree idx = elt.index;
4523 :
4524 0 : int cmp = array_index_cmp (dindex, idx);
4525 0 : if (cmp < 0)
4526 : end = middle;
4527 0 : else if (cmp > 0)
4528 0 : begin = middle + 1;
4529 : else
4530 : {
4531 0 : if (insert && TREE_CODE (idx) == RANGE_EXPR)
4532 : {
4533 : /* We need to split the range. */
4534 0 : constructor_elt e;
4535 0 : tree lo = TREE_OPERAND (idx, 0);
4536 0 : tree hi = TREE_OPERAND (idx, 1);
4537 0 : tree value = elt.value;
4538 0 : dindex = fold_convert (sizetype, dindex);
4539 0 : if (tree_int_cst_lt (lo, dindex))
4540 : {
4541 : /* There are still some lower elts; shorten the range. */
4542 0 : tree new_hi
4543 0 : = int_const_binop (MINUS_EXPR, dindex, size_one_node);
4544 0 : if (tree_int_cst_equal (lo, new_hi))
4545 : /* Only one element left, no longer a range. */
4546 0 : elt.index = lo;
4547 : else
4548 0 : TREE_OPERAND (idx, 1) = new_hi;
4549 : /* Append the element we want to insert. */
4550 0 : ++middle;
4551 0 : e.index = dindex;
4552 0 : e.value = unshare_constructor (value);
4553 0 : vec_safe_insert (CONSTRUCTOR_ELTS (ary), middle, e);
4554 : }
4555 : else
4556 : /* No lower elts, the range elt is now ours. */
4557 0 : elt.index = dindex;
4558 :
4559 0 : if (tree_int_cst_lt (dindex, hi))
4560 : {
4561 : /* There are still some higher elts; append a range. */
4562 0 : tree new_lo
4563 0 : = int_const_binop (PLUS_EXPR, dindex, size_one_node);
4564 0 : if (tree_int_cst_equal (new_lo, hi))
4565 : e.index = hi;
4566 : else
4567 0 : e.index = build2 (RANGE_EXPR, sizetype, new_lo, hi);
4568 0 : e.value = unshare_constructor (value);
4569 0 : vec_safe_insert (CONSTRUCTOR_ELTS (ary), middle + 1, e);
4570 : }
4571 : }
4572 0 : return middle;
4573 : }
4574 : }
4575 :
4576 1 : if (insert)
4577 : {
4578 1 : constructor_elt e = {dindex, NULL_TREE};
4579 1 : vec_safe_insert (CONSTRUCTOR_ELTS (ary), end, e);
4580 1 : return end;
4581 : }
4582 :
4583 : return -1;
4584 : }
4585 :
4586 : /* Some expressions may have constant operands but are not constant
4587 : themselves, such as 1/0. Call this function to check for that
4588 : condition.
4589 :
4590 : We only call this in places that require an arithmetic constant, not in
4591 : places where we might have a non-constant expression that can be a
4592 : component of a constant expression, such as the address of a constexpr
4593 : variable that might be dereferenced later. */
4594 :
4595 : static bool
4596 262562 : verify_constant (tree t, bool allow_non_constant, bool *non_constant_p,
4597 : bool *overflow_p)
4598 : {
4599 262562 : if (!*non_constant_p && !reduced_constant_expression_p (t) && t != void_node)
4600 : {
4601 2 : if (!allow_non_constant)
4602 2 : error_at (EXPR_LOCATION (t), "is not a constant expression");
4603 2 : *non_constant_p = true;
4604 : }
4605 262562 : if (TREE_OVERFLOW_P (t))
4606 : {
4607 0 : if (!allow_non_constant)
4608 : {
4609 0 : permerror (input_location, "overflow in constant expression");
4610 : /* If we're being permissive (and are in an enforcing
4611 : context), ignore the overflow. */
4612 0 : if (flag_permissive)
4613 0 : return *non_constant_p;
4614 : }
4615 0 : *overflow_p = true;
4616 : }
4617 262562 : return *non_constant_p;
4618 : }
4619 :
4620 : // forked from gcc/cp/constexpr.cc find_heap_var_refs
4621 :
4622 : /* Look for heap variables in the expression *TP. */
4623 :
4624 : static tree
4625 0 : find_heap_var_refs (tree *tp, int *walk_subtrees, void * /*data*/)
4626 : {
4627 0 : if (VAR_P (*tp)
4628 0 : && (DECL_NAME (*tp) == heap_uninit_identifier
4629 0 : || DECL_NAME (*tp) == heap_identifier
4630 0 : || DECL_NAME (*tp) == heap_vec_uninit_identifier
4631 0 : || DECL_NAME (*tp) == heap_vec_identifier
4632 0 : || DECL_NAME (*tp) == heap_deleted_identifier))
4633 : return *tp;
4634 :
4635 0 : if (TYPE_P (*tp))
4636 0 : *walk_subtrees = 0;
4637 : return NULL_TREE;
4638 : }
4639 :
4640 : // forked from gcc/cp/constexpr.cc find_immediate_fndecl
4641 :
4642 : /* Find immediate function decls in *TP if any. */
4643 :
4644 : static tree
4645 0 : find_immediate_fndecl (tree *tp, int * /*walk_subtrees*/, void * /*data*/)
4646 : {
4647 0 : if (TREE_CODE (*tp) == FUNCTION_DECL && DECL_IMMEDIATE_FUNCTION_P (*tp))
4648 : return *tp;
4649 0 : if (TREE_CODE (*tp) == PTRMEM_CST
4650 0 : && TREE_CODE (PTRMEM_CST_MEMBER (*tp)) == FUNCTION_DECL
4651 0 : && DECL_IMMEDIATE_FUNCTION_P (PTRMEM_CST_MEMBER (*tp)))
4652 : return PTRMEM_CST_MEMBER (*tp);
4653 : return NULL_TREE;
4654 : }
4655 :
4656 : // forked in gcc/cp/constexpr.cc diag_array_subscript
4657 :
4658 : /* Under the control of CTX, issue a detailed diagnostic for
4659 : an out-of-bounds subscript INDEX into the expression ARRAY. */
4660 :
4661 : static void
4662 1 : diag_array_subscript (location_t loc, const constexpr_ctx *ctx, tree array,
4663 : tree index)
4664 : {
4665 1 : if (!ctx->quiet)
4666 : {
4667 1 : tree arraytype = TREE_TYPE (array);
4668 :
4669 : /* Convert the unsigned array subscript to a signed integer to avoid
4670 : printing huge numbers for small negative values. */
4671 1 : tree sidx = fold_convert (ssizetype, index);
4672 1 : STRIP_ANY_LOCATION_WRAPPER (array);
4673 1 : if (DECL_P (array))
4674 : {
4675 1 : if (TYPE_DOMAIN (arraytype))
4676 1 : error_at (loc,
4677 : "array subscript value %qE is outside the bounds "
4678 : "of array %qD of type %qT",
4679 : sidx, array, arraytype);
4680 : else
4681 0 : error_at (loc,
4682 : "nonzero array subscript %qE is used with array %qD of "
4683 : "type %qT with unknown bounds",
4684 : sidx, array, arraytype);
4685 1 : inform (DECL_SOURCE_LOCATION (array), "declared here");
4686 : }
4687 0 : else if (TYPE_DOMAIN (arraytype))
4688 0 : error_at (loc,
4689 : "array subscript value %qE is outside the bounds "
4690 : "of array type %qT",
4691 : sidx, arraytype);
4692 : else
4693 0 : error_at (loc,
4694 : "nonzero array subscript %qE is used with array of type %qT "
4695 : "with unknown bounds",
4696 : sidx, arraytype);
4697 : }
4698 1 : }
4699 :
4700 : // forked from gcc/cp/constexpr.cc get_array_or_vector_nelts
4701 :
4702 : /* Return the number of elements for TYPE (which is an ARRAY_TYPE or
4703 : a VECTOR_TYPE). */
4704 :
4705 : static tree
4706 10 : get_array_or_vector_nelts (const constexpr_ctx *ctx, tree type,
4707 : bool *non_constant_p, bool *overflow_p,
4708 : tree *jump_target)
4709 : {
4710 10 : tree nelts;
4711 10 : if (TREE_CODE (type) == ARRAY_TYPE)
4712 : {
4713 10 : if (TYPE_DOMAIN (type))
4714 10 : nelts = array_type_nelts_top (type);
4715 : else
4716 0 : nelts = size_zero_node;
4717 : }
4718 0 : else if (VECTOR_TYPE_P (type))
4719 0 : nelts = size_int (TYPE_VECTOR_SUBPARTS (type));
4720 : else
4721 0 : rust_unreachable ();
4722 :
4723 : /* For VLAs, the number of elements won't be an integer constant. */
4724 10 : nelts = eval_constant_expression (ctx, nelts, false, non_constant_p,
4725 : overflow_p, jump_target);
4726 10 : return nelts;
4727 : }
4728 :
4729 : // forked from gcc/cp/constexpr.cc eval_and_check_array_index
4730 :
4731 : /* Subroutine of cxx_eval_array_reference. T is an ARRAY_REF; evaluate the
4732 : subscript, diagnose any problems with it, and return the result. */
4733 :
4734 : static tree
4735 10 : eval_and_check_array_index (const constexpr_ctx *ctx, tree t,
4736 : bool allow_one_past, bool *non_constant_p,
4737 : bool *overflow_p, tree *jump_target)
4738 : {
4739 10 : location_t loc = rs_expr_loc_or_input_loc (t);
4740 10 : tree ary = TREE_OPERAND (t, 0);
4741 10 : t = TREE_OPERAND (t, 1);
4742 10 : tree index = eval_constant_expression (ctx, t, allow_one_past, non_constant_p,
4743 : overflow_p, jump_target);
4744 10 : VERIFY_CONSTANT (index);
4745 :
4746 10 : if (!tree_fits_shwi_p (index) || tree_int_cst_sgn (index) < 0)
4747 : {
4748 0 : diag_array_subscript (loc, ctx, ary, index);
4749 0 : *non_constant_p = true;
4750 0 : return t;
4751 : }
4752 :
4753 10 : tree nelts = get_array_or_vector_nelts (ctx, TREE_TYPE (ary), non_constant_p,
4754 : overflow_p, jump_target);
4755 10 : VERIFY_CONSTANT (nelts);
4756 20 : if (allow_one_past ? !tree_int_cst_le (index, nelts)
4757 10 : : !tree_int_cst_lt (index, nelts))
4758 : {
4759 1 : diag_array_subscript (loc, ctx, ary, index);
4760 1 : *non_constant_p = true;
4761 1 : return t;
4762 : }
4763 :
4764 : return index;
4765 : }
4766 :
4767 : // forked from gcc/cp/constexpr.cc extract_string_elt
4768 :
4769 : /* Extract element INDEX consisting of CHARS_PER_ELT chars from
4770 : STRING_CST STRING. */
4771 :
4772 : static tree
4773 0 : extract_string_elt (tree string, unsigned chars_per_elt, unsigned index)
4774 : {
4775 0 : tree type = cv_unqualified (TREE_TYPE (TREE_TYPE (string)));
4776 0 : tree r;
4777 :
4778 0 : if (chars_per_elt == 1)
4779 0 : r = build_int_cst (type, TREE_STRING_POINTER (string)[index]);
4780 : else
4781 : {
4782 0 : const unsigned char *ptr
4783 0 : = ((const unsigned char *) TREE_STRING_POINTER (string)
4784 0 : + index * chars_per_elt);
4785 0 : r = native_interpret_expr (type, ptr, chars_per_elt);
4786 : }
4787 0 : return r;
4788 : }
4789 :
4790 : /* Check whether the parameter and return types of FUN are valid for a
4791 : constexpr function, and complain if COMPLAIN. */
4792 :
4793 : bool
4794 0 : is_valid_constexpr_fn (tree fun, bool complain)
4795 : {
4796 0 : bool ret = true;
4797 :
4798 0 : for (tree parm = FUNCTION_FIRST_USER_PARM (fun); parm != NULL_TREE;
4799 0 : parm = TREE_CHAIN (parm))
4800 0 : if (!literal_type_p (TREE_TYPE (parm)))
4801 : {
4802 0 : ret = false;
4803 0 : if (complain)
4804 : {
4805 : // auto_diagnostic_group d;
4806 : // error ("invalid type for parameter %d of %<constexpr%> "
4807 : // "function %q+#D",
4808 : // DECL_PARM_INDEX (parm), fun);
4809 0 : location_t locus = DECL_SOURCE_LOCATION (fun);
4810 0 : rust_error_at (
4811 : locus, "invalid type for parameter %d of %<constexpr%> function",
4812 0 : DECL_PARM_INDEX (parm));
4813 : }
4814 : }
4815 :
4816 0 : return ret;
4817 : }
4818 :
4819 : void
4820 0 : explain_invalid_constexpr_fn (tree fun)
4821 : {
4822 0 : static hash_set<tree> *diagnosed;
4823 : // tree body;
4824 :
4825 0 : if (diagnosed == NULL)
4826 0 : diagnosed = new hash_set<tree>;
4827 0 : if (diagnosed->add (fun))
4828 : /* Already explained. */
4829 0 : return;
4830 :
4831 0 : iloc_sentinel ils = input_location;
4832 : // if (!lambda_static_thunk_p (fun))
4833 : // {
4834 : // /* Diagnostics should completely ignore the static thunk, so leave
4835 : // input_location set to our caller's location. */
4836 : // input_location = DECL_SOURCE_LOCATION (fun);
4837 : // inform (input_location,
4838 : // "%qD is not usable as a %<constexpr%> function because:",
4839 : // fun);
4840 : // }
4841 :
4842 : /* First check the declaration. */
4843 0 : if (is_valid_constexpr_fn (fun, true))
4844 : {
4845 : // /* Then if it's OK, the body. */
4846 : // if (!DECL_DECLARED_CONSTEXPR_P (fun))
4847 : // explain_implicit_non_constexpr (fun);
4848 : // else
4849 : // {
4850 : // if (constexpr_fundef *fd = retrieve_constexpr_fundef (fun))
4851 : // body = fd->body;
4852 : // else
4853 : // body = DECL_SAVED_TREE (fun);
4854 : // body = massage_constexpr_body (fun, body);
4855 : // require_potential_rvalue_constant_expression (body);
4856 : // }
4857 : }
4858 0 : }
4859 :
4860 : /* BODY is a validated and massaged definition of a constexpr
4861 : function. Register it in the hash table. */
4862 :
4863 : void
4864 6084 : register_constexpr_fundef (const rust_constexpr_fundef &value)
4865 : {
4866 : /* Create the constexpr function table if necessary. */
4867 6084 : if (constexpr_fundef_table == NULL)
4868 962 : constexpr_fundef_table
4869 962 : = hash_table<rust_constexpr_fundef_hasher>::create_ggc (101);
4870 :
4871 12168 : rust_constexpr_fundef **slot = constexpr_fundef_table->find_slot (
4872 6084 : const_cast<rust_constexpr_fundef *> (&value), INSERT);
4873 :
4874 6084 : gcc_assert (*slot == NULL);
4875 6084 : *slot = ggc_alloc<rust_constexpr_fundef> ();
4876 6084 : **slot = value;
4877 6084 : }
4878 :
4879 : /* We are processing the definition of the constexpr function FUN.
4880 : Check that its body fulfills the apropriate requirements and
4881 : enter it in the constexpr function definition table. */
4882 :
4883 : void
4884 6084 : maybe_save_constexpr_fundef (tree fun)
4885 : {
4886 : // FIXME
4887 :
4888 6084 : rust_constexpr_fundef entry = {fun, NULL_TREE, NULL_TREE, NULL_TREE};
4889 6084 : bool clear_ctx = false;
4890 6084 : if (DECL_RESULT (fun) && DECL_CONTEXT (DECL_RESULT (fun)) == NULL_TREE)
4891 : {
4892 0 : clear_ctx = true;
4893 0 : DECL_CONTEXT (DECL_RESULT (fun)) = fun;
4894 : }
4895 6084 : tree saved_fn = current_function_decl;
4896 6084 : current_function_decl = fun;
4897 6084 : entry.body = copy_fn (entry.decl, entry.parms, entry.result);
4898 6084 : current_function_decl = saved_fn;
4899 6084 : if (clear_ctx)
4900 0 : DECL_CONTEXT (DECL_RESULT (entry.decl)) = NULL_TREE;
4901 :
4902 6084 : register_constexpr_fundef (entry);
4903 6084 : }
4904 :
4905 : /* Evaluate a STATEMENT_LIST for side-effects. Handles various jump
4906 : semantics, for switch, break, continue, and return. */
4907 :
4908 : static tree
4909 264641 : eval_statement_list (const constexpr_ctx *ctx, tree t, bool *non_constant_p,
4910 : bool *overflow_p, tree *jump_target)
4911 : {
4912 264641 : tree local_target;
4913 : /* In a statement-expression we want to return the last value.
4914 : For empty statement expression return void_node. */
4915 264641 : tree r = void_node;
4916 264641 : if (!jump_target)
4917 : {
4918 0 : local_target = NULL_TREE;
4919 0 : jump_target = &local_target;
4920 : }
4921 1053311 : for (tree stmt : tsi_range (t))
4922 : {
4923 : /* We've found a continue, so skip everything until we reach
4924 : the label its jumping to. */
4925 791109 : if (continues (jump_target))
4926 : {
4927 0 : if (label_matches (ctx, jump_target, stmt))
4928 : /* Found it. */
4929 0 : *jump_target = NULL_TREE;
4930 : else
4931 0 : continue;
4932 : }
4933 791109 : if (TREE_CODE (stmt) == DEBUG_BEGIN_STMT)
4934 0 : continue;
4935 791109 : r = eval_constant_expression (ctx, stmt, false, non_constant_p,
4936 : overflow_p, jump_target);
4937 791109 : if (*non_constant_p)
4938 : break;
4939 791091 : if (returns (jump_target) || breaks (jump_target))
4940 : break;
4941 : }
4942 264641 : if (*jump_target && jump_target == &local_target)
4943 : {
4944 : /* We aren't communicating the jump to our caller, so give up. We don't
4945 : need to support evaluation of jumps out of statement-exprs. */
4946 0 : if (!ctx->quiet)
4947 0 : error_at (EXPR_LOCATION (r), "statement is not a constant expression");
4948 0 : *non_constant_p = true;
4949 : }
4950 264641 : return r;
4951 : }
4952 :
4953 : // forked from gcc/cp/constexpr.cc cxx_eval_conditional_expression
4954 :
4955 : /* Subroutine of cxx_eval_constant_expression.
4956 : Attempt to evaluate condition expressions. Dead branches are not
4957 : looked into. */
4958 :
4959 : static tree
4960 21 : eval_conditional_expression (const constexpr_ctx *ctx, tree t, bool lval,
4961 : bool *non_constant_p, bool *overflow_p,
4962 : tree *jump_target)
4963 : {
4964 21 : tree val = eval_constant_expression (ctx, TREE_OPERAND (t, 0),
4965 : /*lval*/ false, non_constant_p,
4966 : overflow_p, jump_target);
4967 21 : VERIFY_CONSTANT (val);
4968 21 : if (TREE_CODE (t) == IF_STMT && IF_STMT_CONSTEVAL_P (t))
4969 : {
4970 : /* Evaluate the condition as if it was
4971 : if (__builtin_is_constant_evaluated ()), i.e. defer it if not
4972 : ctx->manifestly_const_eval (as sometimes we try to constant evaluate
4973 : without manifestly_const_eval even expressions or parts thereof which
4974 : will later be manifestly const_eval evaluated), otherwise fold it to
4975 : true. */
4976 0 : if (ctx->manifestly_const_eval)
4977 0 : val = boolean_true_node;
4978 : else
4979 : {
4980 0 : *non_constant_p = true;
4981 0 : return t;
4982 : }
4983 : }
4984 : /* Don't VERIFY_CONSTANT the other operands. */
4985 21 : if (integer_zerop (val))
4986 13 : val = TREE_OPERAND (t, 2);
4987 : else
4988 8 : val = TREE_OPERAND (t, 1);
4989 21 : if (/*TREE_CODE (t) == IF_STMT && */ !val)
4990 12 : val = void_node;
4991 21 : return eval_constant_expression (ctx, val, lval, non_constant_p, overflow_p,
4992 21 : jump_target);
4993 : }
4994 :
4995 : // forked from gcc/cp/constexpr.cc cxx_eval_bit_field_ref
4996 :
4997 : /* Subroutine of cxx_eval_constant_expression.
4998 : Attempt to reduce a field access of a value of class type that is
4999 : expressed as a BIT_FIELD_REF. */
5000 :
5001 : static tree
5002 0 : eval_bit_field_ref (const constexpr_ctx *ctx, tree t, bool lval,
5003 : bool *non_constant_p, bool *overflow_p, tree *jump_target)
5004 : {
5005 0 : tree orig_whole = TREE_OPERAND (t, 0);
5006 0 : tree retval, fldval, utype, mask;
5007 0 : bool fld_seen = false;
5008 0 : HOST_WIDE_INT istart, isize;
5009 0 : tree whole = eval_constant_expression (ctx, orig_whole, lval, non_constant_p,
5010 : overflow_p, jump_target);
5011 0 : tree start, field, value;
5012 0 : unsigned HOST_WIDE_INT i;
5013 :
5014 0 : if (whole == orig_whole)
5015 : return t;
5016 : /* Don't VERIFY_CONSTANT here; we only want to check that we got a
5017 : CONSTRUCTOR. */
5018 0 : if (!*non_constant_p && TREE_CODE (whole) != VECTOR_CST
5019 0 : && TREE_CODE (whole) != CONSTRUCTOR)
5020 : {
5021 0 : if (!ctx->quiet)
5022 0 : error ("%qE is not a constant expression", orig_whole);
5023 0 : *non_constant_p = true;
5024 : }
5025 0 : if (*non_constant_p)
5026 : return t;
5027 :
5028 0 : if (TREE_CODE (whole) == VECTOR_CST)
5029 0 : return fold_ternary (BIT_FIELD_REF, TREE_TYPE (t), whole,
5030 : TREE_OPERAND (t, 1), TREE_OPERAND (t, 2));
5031 :
5032 0 : start = TREE_OPERAND (t, 2);
5033 0 : istart = tree_to_shwi (start);
5034 0 : isize = tree_to_shwi (TREE_OPERAND (t, 1));
5035 0 : utype = TREE_TYPE (t);
5036 0 : if (!TYPE_UNSIGNED (utype))
5037 0 : utype = build_nonstandard_integer_type (TYPE_PRECISION (utype), 1);
5038 0 : retval = build_int_cst (utype, 0);
5039 0 : FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (whole), i, field, value)
5040 : {
5041 0 : tree bitpos = bit_position (field);
5042 0 : STRIP_ANY_LOCATION_WRAPPER (value);
5043 0 : if (bitpos == start && DECL_SIZE (field) == TREE_OPERAND (t, 1))
5044 : return value;
5045 0 : if (TREE_CODE (TREE_TYPE (field)) == INTEGER_TYPE
5046 0 : && TREE_CODE (value) == INTEGER_CST && tree_fits_shwi_p (bitpos)
5047 0 : && tree_fits_shwi_p (DECL_SIZE (field)))
5048 : {
5049 0 : HOST_WIDE_INT bit = tree_to_shwi (bitpos);
5050 0 : HOST_WIDE_INT sz = tree_to_shwi (DECL_SIZE (field));
5051 0 : HOST_WIDE_INT shift;
5052 0 : if (bit >= istart && bit + sz <= istart + isize)
5053 : {
5054 0 : fldval = fold_convert (utype, value);
5055 0 : mask = build_int_cst_type (utype, -1);
5056 0 : mask = fold_build2 (LSHIFT_EXPR, utype, mask,
5057 : size_int (TYPE_PRECISION (utype) - sz));
5058 0 : mask = fold_build2 (RSHIFT_EXPR, utype, mask,
5059 : size_int (TYPE_PRECISION (utype) - sz));
5060 0 : fldval = fold_build2 (BIT_AND_EXPR, utype, fldval, mask);
5061 0 : shift = bit - istart;
5062 0 : if (BYTES_BIG_ENDIAN)
5063 : shift = TYPE_PRECISION (utype) - shift - sz;
5064 0 : fldval
5065 0 : = fold_build2 (LSHIFT_EXPR, utype, fldval, size_int (shift));
5066 0 : retval = fold_build2 (BIT_IOR_EXPR, utype, retval, fldval);
5067 0 : fld_seen = true;
5068 : }
5069 : }
5070 : }
5071 0 : if (fld_seen)
5072 0 : return fold_convert (TREE_TYPE (t), retval);
5073 0 : rust_unreachable ();
5074 : return error_mark_node;
5075 : }
5076 :
5077 : // forked from gcc/cp/constexpr.cc returns
5078 :
5079 : /* Predicates for the meaning of *jump_target. */
5080 :
5081 : static bool
5082 1053256 : returns (tree *jump_target)
5083 : {
5084 1053256 : return *jump_target
5085 1053256 : && (TREE_CODE (*jump_target) == RETURN_EXPR
5086 16 : || (TREE_CODE (*jump_target) == LABEL_DECL
5087 9 : && LABEL_DECL_CDTOR (*jump_target)));
5088 : }
5089 :
5090 : // forked from gcc/cp/constexpr.cc breaks
5091 :
5092 : static bool
5093 1313010 : breaks (tree *jump_target)
5094 : {
5095 1313010 : return *jump_target
5096 1313010 : && ((TREE_CODE (*jump_target) == LABEL_DECL
5097 9 : && LABEL_DECL_BREAK (*jump_target))
5098 20 : || TREE_CODE (*jump_target) == BREAK_STMT
5099 20 : || TREE_CODE (*jump_target) == EXIT_EXPR);
5100 : }
5101 :
5102 : // forked from gcc/cp/constexpr.cc continues
5103 :
5104 : static bool
5105 1053274 : continues (tree *jump_target)
5106 : {
5107 1053274 : return *jump_target
5108 1053274 : && ((TREE_CODE (*jump_target) == LABEL_DECL
5109 7 : && LABEL_DECL_CONTINUE (*jump_target))
5110 7 : || TREE_CODE (*jump_target) == CONTINUE_STMT);
5111 : }
5112 :
5113 : // forked from gcc/cp/constexpr.cc switches
5114 :
5115 : static bool
5116 262163 : switches (tree *jump_target)
5117 : {
5118 262163 : return *jump_target && TREE_CODE (*jump_target) == INTEGER_CST;
5119 : }
5120 :
5121 : // forked from gcc/cp/constexpr.cc cxx_eval_loop_expr
5122 :
5123 : /* Evaluate a LOOP_EXPR for side-effects. Handles break and return
5124 : semantics; continue semantics are covered by cxx_eval_statement_list. */
5125 :
5126 : static tree
5127 5 : eval_loop_expr (const constexpr_ctx *ctx, tree t, bool *non_constant_p,
5128 : bool *overflow_p, tree *jump_target)
5129 : {
5130 5 : constexpr_ctx new_ctx = *ctx;
5131 5 : tree local_target;
5132 5 : if (!jump_target)
5133 : {
5134 0 : local_target = NULL_TREE;
5135 0 : jump_target = &local_target;
5136 : }
5137 :
5138 5 : tree body, cond = NULL_TREE, expr = NULL_TREE;
5139 5 : int count = 0;
5140 5 : switch (TREE_CODE (t))
5141 : {
5142 5 : case LOOP_EXPR:
5143 5 : body = LOOP_EXPR_BODY (t);
5144 5 : break;
5145 0 : case WHILE_STMT:
5146 0 : body = WHILE_BODY (t);
5147 0 : cond = WHILE_COND (t);
5148 0 : count = -1;
5149 0 : break;
5150 0 : case FOR_STMT:
5151 0 : if (FOR_INIT_STMT (t))
5152 0 : eval_constant_expression (ctx, FOR_INIT_STMT (t), /*lval*/ false,
5153 : non_constant_p, overflow_p, jump_target);
5154 0 : if (*non_constant_p)
5155 : return NULL_TREE;
5156 0 : body = FOR_BODY (t);
5157 0 : cond = FOR_COND (t);
5158 0 : expr = FOR_EXPR (t);
5159 0 : count = -1;
5160 0 : break;
5161 0 : default:
5162 0 : rust_unreachable ();
5163 : }
5164 10 : auto_vec<tree, 10> save_exprs;
5165 5 : new_ctx.save_exprs = &save_exprs;
5166 262168 : do
5167 : {
5168 262168 : if (count != -1)
5169 : {
5170 262168 : if (body)
5171 262168 : eval_constant_expression (&new_ctx, body, /*lval*/ false,
5172 : non_constant_p, overflow_p, jump_target);
5173 262168 : if (breaks (jump_target))
5174 : {
5175 4 : *jump_target = NULL_TREE;
5176 4 : break;
5177 : }
5178 :
5179 262164 : if (TREE_CODE (t) != LOOP_EXPR && continues (jump_target))
5180 0 : *jump_target = NULL_TREE;
5181 :
5182 262164 : if (expr)
5183 0 : eval_constant_expression (&new_ctx, expr, /*lval*/ false,
5184 : non_constant_p, overflow_p, jump_target);
5185 : }
5186 :
5187 262164 : if (cond)
5188 : {
5189 0 : tree res = eval_constant_expression (&new_ctx, cond, /*lval*/ false,
5190 : non_constant_p, overflow_p,
5191 : jump_target);
5192 0 : if (res)
5193 : {
5194 0 : if (verify_constant (res, ctx->quiet, non_constant_p, overflow_p))
5195 : break;
5196 0 : if (integer_zerop (res))
5197 : break;
5198 : }
5199 : else
5200 0 : gcc_assert (*jump_target);
5201 : }
5202 :
5203 : /* Forget saved values of SAVE_EXPRs and TARGET_EXPRs. */
5204 786492 : for (tree save_expr : save_exprs)
5205 0 : ctx->global->values.remove (save_expr);
5206 262164 : save_exprs.truncate (0);
5207 :
5208 262164 : if (++count >= constexpr_loop_limit)
5209 : {
5210 1 : if (!ctx->quiet)
5211 2 : error_at (rs_expr_loc_or_input_loc (t),
5212 : "%<constexpr%> loop iteration count exceeds limit of %d "
5213 : "(use %<-fconstexpr-loop-limit=%> to increase the limit)",
5214 : constexpr_loop_limit);
5215 1 : *non_constant_p = true;
5216 1 : break;
5217 : }
5218 : }
5219 262163 : while (!returns (jump_target) && !breaks (jump_target)
5220 262163 : && !continues (jump_target) && (!switches (jump_target) || count == 0)
5221 524326 : && !*non_constant_p);
5222 :
5223 : /* Forget saved values of SAVE_EXPRs and TARGET_EXPRs. */
5224 15 : for (tree save_expr : save_exprs)
5225 0 : ctx->global->values.remove (save_expr);
5226 :
5227 5 : return NULL_TREE;
5228 : }
5229 :
5230 : // forked from gcc/cp/constexpr.cc cxx_eval_switch_expr
5231 :
5232 : /* Evaluate a SWITCH_EXPR for side-effects. Handles switch and break jump
5233 : semantics. */
5234 :
5235 : static tree
5236 0 : eval_switch_expr (const constexpr_ctx *ctx, tree t, bool *non_constant_p,
5237 : bool *overflow_p, tree *jump_target)
5238 : {
5239 0 : tree cond
5240 0 : = TREE_CODE (t) == SWITCH_STMT ? SWITCH_STMT_COND (t) : SWITCH_COND (t);
5241 0 : cond = eval_constant_expression (ctx, cond, false, non_constant_p, overflow_p,
5242 : jump_target);
5243 0 : VERIFY_CONSTANT (cond);
5244 0 : *jump_target = cond;
5245 :
5246 0 : tree body
5247 0 : = TREE_CODE (t) == SWITCH_STMT ? SWITCH_STMT_BODY (t) : SWITCH_BODY (t);
5248 0 : constexpr_ctx new_ctx = *ctx;
5249 0 : constexpr_switch_state css = css_default_not_seen;
5250 0 : new_ctx.css_state = &css;
5251 0 : eval_constant_expression (&new_ctx, body, false, non_constant_p, overflow_p,
5252 : jump_target);
5253 0 : if (switches (jump_target) && css == css_default_seen)
5254 : {
5255 : /* If the SWITCH_EXPR body has default: label, process it once again,
5256 : this time instructing label_matches to return true for default:
5257 : label on switches (jump_target). */
5258 0 : css = css_default_processing;
5259 0 : eval_constant_expression (&new_ctx, body, false, non_constant_p,
5260 : overflow_p, jump_target);
5261 : }
5262 0 : if (breaks (jump_target) || switches (jump_target))
5263 0 : *jump_target = NULL_TREE;
5264 : return NULL_TREE;
5265 : }
5266 :
5267 : // forked from gcc/cp/constexpr.cc eval_unary_expression
5268 :
5269 : /* Subroutine of cxx_eval_constant_expression.
5270 : Attempt to reduce the unary expression tree T to a compile time value.
5271 : If successful, return the value. Otherwise issue a diagnostic
5272 : and return error_mark_node. */
5273 :
5274 : static tree
5275 7 : eval_unary_expression (const constexpr_ctx *ctx, tree t, bool /*lval*/,
5276 : bool *non_constant_p, bool *overflow_p,
5277 : tree *jump_target)
5278 : {
5279 7 : tree r;
5280 7 : tree orig_arg = TREE_OPERAND (t, 0);
5281 7 : tree arg = eval_constant_expression (ctx, orig_arg, /*lval*/ false,
5282 : non_constant_p, overflow_p, jump_target);
5283 7 : VERIFY_CONSTANT (arg);
5284 7 : location_t loc = EXPR_LOCATION (t);
5285 7 : enum tree_code code = TREE_CODE (t);
5286 7 : tree type = TREE_TYPE (t);
5287 7 : r = fold_unary_loc (loc, code, type, arg);
5288 7 : if (r == NULL_TREE)
5289 : {
5290 0 : if (arg == orig_arg)
5291 : r = t;
5292 : else
5293 0 : r = build1_loc (loc, code, type, arg);
5294 : }
5295 7 : VERIFY_CONSTANT (r);
5296 : return r;
5297 : }
5298 :
5299 : // forked from gcc/cp/constexpr.cc cxx_eval_outermost_constant_expr
5300 :
5301 : /* ALLOW_NON_CONSTANT is false if T is required to be a constant expression.
5302 : STRICT has the same sense as for constant_value_1: true if we only allow
5303 : conforming C++ constant expressions, or false if we want a constant value
5304 : even if it doesn't conform.
5305 : MANIFESTLY_CONST_EVAL is true if T is manifestly const-evaluated as
5306 : per P0595 even when ALLOW_NON_CONSTANT is true.
5307 : CONSTEXPR_DTOR is true when evaluating the dtor of a constexpr variable.
5308 : OBJECT must be non-NULL in that case. */
5309 :
5310 : static tree
5311 0 : cxx_eval_outermost_constant_expr (tree t, bool allow_non_constant,
5312 : bool strict = true,
5313 : bool manifestly_const_eval = false,
5314 : bool constexpr_dtor = false,
5315 : tree object = NULL_TREE)
5316 : {
5317 0 : auto_timevar time (TV_CONSTEXPR);
5318 :
5319 0 : bool non_constant_p = false;
5320 0 : bool overflow_p = false;
5321 :
5322 0 : if (BRACE_ENCLOSED_INITIALIZER_P (t))
5323 : {
5324 0 : gcc_checking_assert (allow_non_constant);
5325 : return t;
5326 : }
5327 :
5328 0 : constexpr_global_ctx global_ctx;
5329 0 : constexpr_ctx ctx
5330 : = {&global_ctx, NULL,
5331 : NULL, NULL,
5332 : NULL, NULL,
5333 : NULL, allow_non_constant,
5334 0 : strict, manifestly_const_eval || !allow_non_constant};
5335 :
5336 : /* Turn off -frounding-math for manifestly constant evaluation. */
5337 0 : warning_sentinel rm (flag_rounding_math, ctx.manifestly_const_eval);
5338 0 : tree type = initialized_type (t);
5339 0 : tree r = t;
5340 0 : bool is_consteval = false;
5341 0 : if (VOID_TYPE_P (type))
5342 : {
5343 0 : if (constexpr_dtor)
5344 : /* Used for destructors of array elements. */
5345 0 : type = TREE_TYPE (object);
5346 : else
5347 : {
5348 0 : if (TREE_CODE (t) != CALL_EXPR)
5349 : return t;
5350 : /* Calls to immediate functions returning void need to be
5351 : evaluated. */
5352 0 : tree fndecl = rs_get_callee_fndecl_nofold (t);
5353 0 : if (fndecl == NULL_TREE || !DECL_IMMEDIATE_FUNCTION_P (fndecl))
5354 : return t;
5355 : else
5356 : is_consteval = true;
5357 : }
5358 : }
5359 0 : else if ((TREE_CODE (t) == CALL_EXPR || TREE_CODE (t) == TARGET_EXPR))
5360 : {
5361 : /* For non-concept checks, determine if it is consteval. */
5362 0 : tree x = t;
5363 0 : if (TREE_CODE (x) == TARGET_EXPR)
5364 0 : x = TARGET_EXPR_INITIAL (x);
5365 0 : tree fndecl = rs_get_callee_fndecl_nofold (x);
5366 0 : if (fndecl && DECL_IMMEDIATE_FUNCTION_P (fndecl))
5367 : is_consteval = true;
5368 : }
5369 0 : if (AGGREGATE_TYPE_P (type) || VECTOR_TYPE_P (type))
5370 : {
5371 : /* In C++14 an NSDMI can participate in aggregate initialization,
5372 : and can refer to the address of the object being initialized, so
5373 : we need to pass in the relevant VAR_DECL if we want to do the
5374 : evaluation in a single pass. The evaluation will dynamically
5375 : update ctx.values for the VAR_DECL. We use the same strategy
5376 : for C++11 constexpr constructors that refer to the object being
5377 : initialized. */
5378 0 : if (constexpr_dtor)
5379 : {
5380 0 : gcc_assert (object && VAR_P (object));
5381 0 : gcc_assert (DECL_DECLARED_CONSTEXPR_P (object));
5382 0 : gcc_assert (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (object));
5383 0 : if (error_operand_p (DECL_INITIAL (object)))
5384 : return t;
5385 0 : ctx.ctor = unshare_expr (DECL_INITIAL (object));
5386 0 : TREE_READONLY (ctx.ctor) = false;
5387 : /* Temporarily force decl_really_constant_value to return false
5388 : for it, we want to use ctx.ctor for the current value instead. */
5389 0 : DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (object) = false;
5390 : }
5391 : else
5392 : {
5393 0 : ctx.ctor = build_constructor (type, NULL);
5394 0 : CONSTRUCTOR_NO_CLEARING (ctx.ctor) = true;
5395 : }
5396 0 : if (!object)
5397 : {
5398 0 : if (TREE_CODE (t) == TARGET_EXPR)
5399 0 : object = TARGET_EXPR_SLOT (t);
5400 : }
5401 0 : ctx.object = object;
5402 0 : if (object)
5403 0 : gcc_assert (
5404 : same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (object)));
5405 0 : if (object && DECL_P (object))
5406 0 : global_ctx.values.put (object, ctx.ctor);
5407 0 : if (TREE_CODE (r) == TARGET_EXPR)
5408 : /* Avoid creating another CONSTRUCTOR when we expand the
5409 : TARGET_EXPR. */
5410 0 : r = TARGET_EXPR_INITIAL (r);
5411 : }
5412 :
5413 0 : auto_vec<tree, 16> cleanups;
5414 0 : global_ctx.cleanups = &cleanups;
5415 :
5416 0 : if (manifestly_const_eval)
5417 0 : instantiate_constexpr_fns (r);
5418 0 : tree jump_target = NULL_TREE;
5419 0 : r = eval_constant_expression (&ctx, r, false, &non_constant_p, &overflow_p,
5420 : &jump_target);
5421 :
5422 0 : if (!constexpr_dtor)
5423 0 : verify_constant (r, allow_non_constant, &non_constant_p, &overflow_p);
5424 : else
5425 0 : DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (object) = true;
5426 :
5427 0 : unsigned int i;
5428 0 : tree cleanup;
5429 : /* Evaluate the cleanups. */
5430 0 : FOR_EACH_VEC_ELT_REVERSE (cleanups, i, cleanup)
5431 0 : eval_constant_expression (&ctx, cleanup, false, &non_constant_p,
5432 : &overflow_p, NULL);
5433 :
5434 : /* Mutable logic is a bit tricky: we want to allow initialization of
5435 : constexpr variables with mutable members, but we can't copy those
5436 : members to another constexpr variable. */
5437 0 : if (TREE_CODE (r) == CONSTRUCTOR && CONSTRUCTOR_MUTABLE_POISON (r))
5438 : {
5439 0 : if (!allow_non_constant)
5440 0 : error ("%qE is not a constant expression because it refers to "
5441 : "mutable subobjects of %qT",
5442 : t, type);
5443 0 : non_constant_p = true;
5444 : }
5445 :
5446 0 : if (TREE_CODE (r) == CONSTRUCTOR && CONSTRUCTOR_NO_CLEARING (r))
5447 : {
5448 0 : if (!allow_non_constant)
5449 0 : error ("%qE is not a constant expression because it refers to "
5450 : "an incompletely initialized variable",
5451 : t);
5452 0 : TREE_CONSTANT (r) = false;
5453 0 : non_constant_p = true;
5454 : }
5455 :
5456 0 : if (!global_ctx.heap_vars.is_empty ())
5457 : {
5458 0 : tree heap_var
5459 0 : = rs_walk_tree_without_duplicates (&r, find_heap_var_refs, NULL);
5460 0 : unsigned int i;
5461 0 : if (heap_var)
5462 : {
5463 0 : if (!allow_non_constant && !non_constant_p)
5464 0 : error_at (DECL_SOURCE_LOCATION (heap_var),
5465 : "%qE is not a constant expression because it refers to "
5466 : "a result of %<operator new%>",
5467 : t);
5468 0 : r = t;
5469 0 : non_constant_p = true;
5470 : }
5471 0 : FOR_EACH_VEC_ELT (global_ctx.heap_vars, i, heap_var)
5472 : {
5473 0 : if (DECL_NAME (heap_var) != heap_deleted_identifier)
5474 : {
5475 0 : if (!allow_non_constant && !non_constant_p)
5476 0 : error_at (DECL_SOURCE_LOCATION (heap_var),
5477 : "%qE is not a constant expression because allocated "
5478 : "storage has not been deallocated",
5479 : t);
5480 0 : r = t;
5481 0 : non_constant_p = true;
5482 : }
5483 0 : varpool_node::get (heap_var)->remove ();
5484 : }
5485 : }
5486 :
5487 : /* Check that immediate invocation does not return an expression referencing
5488 : any immediate function decls. */
5489 0 : if (is_consteval || in_immediate_context ())
5490 0 : if (tree immediate_fndecl
5491 0 : = rs_walk_tree_without_duplicates (&r, find_immediate_fndecl, NULL))
5492 : {
5493 0 : if (!allow_non_constant && !non_constant_p)
5494 0 : error_at (rs_expr_loc_or_input_loc (t),
5495 : "immediate evaluation returns address of immediate "
5496 : "function %qD",
5497 : immediate_fndecl);
5498 0 : r = t;
5499 0 : non_constant_p = true;
5500 : }
5501 :
5502 0 : if (non_constant_p)
5503 : /* If we saw something bad, go back to our argument. The wrapping below is
5504 : only for the cases of TREE_CONSTANT argument or overflow. */
5505 0 : r = t;
5506 :
5507 0 : if (!non_constant_p && overflow_p)
5508 0 : non_constant_p = true;
5509 :
5510 : /* Unshare the result. */
5511 0 : bool should_unshare = true;
5512 0 : if (r == t || (TREE_CODE (t) == TARGET_EXPR && TARGET_EXPR_INITIAL (t) == r))
5513 : should_unshare = false;
5514 :
5515 0 : if (non_constant_p && !allow_non_constant)
5516 0 : return error_mark_node;
5517 0 : else if (constexpr_dtor)
5518 : return r;
5519 0 : else if (non_constant_p && TREE_CONSTANT (r))
5520 : {
5521 : /* This isn't actually constant, so unset TREE_CONSTANT.
5522 : Don't clear TREE_CONSTANT on ADDR_EXPR, as the middle-end requires
5523 : it to be set if it is invariant address, even when it is not
5524 : a valid C++ constant expression. Wrap it with a NOP_EXPR
5525 : instead. */
5526 0 : if (EXPR_P (r) && TREE_CODE (r) != ADDR_EXPR)
5527 0 : r = copy_node (r);
5528 0 : else if (TREE_CODE (r) == CONSTRUCTOR)
5529 0 : r = build1 (VIEW_CONVERT_EXPR, TREE_TYPE (r), r);
5530 : else
5531 0 : r = build_nop (TREE_TYPE (r), r);
5532 0 : TREE_CONSTANT (r) = false;
5533 : }
5534 0 : else if (non_constant_p)
5535 : return t;
5536 :
5537 0 : if (should_unshare)
5538 0 : r = unshare_expr (r);
5539 :
5540 0 : if (TREE_CODE (r) == CONSTRUCTOR && CLASS_TYPE_P (TREE_TYPE (r)))
5541 : {
5542 0 : r = adjust_temp_type (type, r);
5543 0 : if (TREE_CODE (t) == TARGET_EXPR && TARGET_EXPR_INITIAL (t) == r)
5544 : return t;
5545 : }
5546 :
5547 : /* Remember the original location if that wouldn't need a wrapper. */
5548 0 : if (location_t loc = EXPR_LOCATION (t))
5549 0 : protected_set_expr_location (r, loc);
5550 :
5551 0 : return r;
5552 0 : }
5553 :
5554 : /* Like is_constant_expression, but allow const variables that are not allowed
5555 : under constexpr rules. */
5556 :
5557 : bool
5558 0 : is_static_init_expression (tree t)
5559 : {
5560 0 : return potential_constant_expression_1 (t, false, false, true, tf_none);
5561 : }
5562 :
5563 : /* Like potential_constant_expression, but don't consider possible constexpr
5564 : substitution of the current function. That is, PARM_DECL qualifies under
5565 : potential_constant_expression, but not here.
5566 :
5567 : This is basically what you can check when any actual constant values might
5568 : be value-dependent. */
5569 :
5570 : bool
5571 0 : is_constant_expression (tree t)
5572 : {
5573 0 : return potential_constant_expression_1 (t, false, true, true, tf_none);
5574 : }
5575 :
5576 : /* Returns true if T is a potential static initializer expression that is not
5577 : instantiation-dependent. */
5578 :
5579 : bool
5580 0 : is_nondependent_static_init_expression (tree t)
5581 : {
5582 0 : return (!type_unknown_p (t) && is_static_init_expression (t));
5583 : }
5584 :
5585 : /* Like maybe_constant_value, but returns a CONSTRUCTOR directly, rather
5586 : than wrapped in a TARGET_EXPR.
5587 : ALLOW_NON_CONSTANT is false if T is required to be a constant expression.
5588 : MANIFESTLY_CONST_EVAL is true if T is manifestly const-evaluated as
5589 : per P0595 even when ALLOW_NON_CONSTANT is true. */
5590 :
5591 : static tree
5592 0 : maybe_constant_init_1 (tree t, tree decl, bool allow_non_constant,
5593 : bool manifestly_const_eval)
5594 : {
5595 0 : if (!t)
5596 : return t;
5597 0 : if (TREE_CODE (t) == EXPR_STMT)
5598 0 : t = TREE_OPERAND (t, 0);
5599 0 : if (TREE_CODE (t) == CONVERT_EXPR && VOID_TYPE_P (TREE_TYPE (t)))
5600 0 : t = TREE_OPERAND (t, 0);
5601 0 : if (TREE_CODE (t) == INIT_EXPR)
5602 0 : t = TREE_OPERAND (t, 1);
5603 0 : if (TREE_CODE (t) == TARGET_EXPR)
5604 0 : t = TARGET_EXPR_INITIAL (t);
5605 0 : if (!is_nondependent_static_init_expression (t))
5606 : /* Don't try to evaluate it. */;
5607 0 : else if (CONSTANT_CLASS_P (t) && allow_non_constant)
5608 : /* No evaluation needed. */;
5609 : else
5610 0 : t = cxx_eval_outermost_constant_expr (t, allow_non_constant,
5611 : /*strict*/ false,
5612 : manifestly_const_eval, false, decl);
5613 0 : if (TREE_CODE (t) == TARGET_EXPR)
5614 : {
5615 0 : tree init = TARGET_EXPR_INITIAL (t);
5616 0 : if (TREE_CODE (init) == CONSTRUCTOR)
5617 0 : t = init;
5618 : }
5619 : return t;
5620 : }
5621 :
5622 : /* Wrapper for maybe_constant_init_1 which permits non constants. */
5623 :
5624 : tree
5625 0 : maybe_constant_init (tree t, tree decl, bool manifestly_const_eval)
5626 : {
5627 0 : return maybe_constant_init_1 (t, decl, true, manifestly_const_eval);
5628 : }
5629 :
5630 : /* Returns true if T is a potential constant expression that is not
5631 : instantiation-dependent, and therefore a candidate for constant folding even
5632 : in a template. */
5633 :
5634 : bool
5635 0 : is_nondependent_constant_expression (tree t)
5636 : {
5637 0 : return (!type_unknown_p (t) && is_constant_expression (t)
5638 0 : && !instantiation_dependent_expression_p (t));
5639 : }
5640 :
5641 : // forked from gcc/cp/parser.cc cp_unevaluated_operand
5642 :
5643 : /* Nonzero if we are parsing an unevaluated operand: an operand to
5644 : sizeof, typeof, or alignof. */
5645 : int cp_unevaluated_operand;
5646 :
5647 : // forked from gcc/cp/constexpr.cc cv_cache
5648 :
5649 : /* If T is a constant expression, returns its reduced value.
5650 : Otherwise, if T does not have TREE_CONSTANT set, returns T.
5651 : Otherwise, returns a version of T without TREE_CONSTANT.
5652 : MANIFESTLY_CONST_EVAL is true if T is manifestly const-evaluated
5653 : as per P0595. */
5654 :
5655 : static GTY ((deletable)) hash_map<tree, tree> *cv_cache;
5656 :
5657 : // forked from gcc/cp/constexpr.cc maybe_constant_value
5658 :
5659 : tree
5660 0 : maybe_constant_value (tree t, tree decl, bool manifestly_const_eval)
5661 : {
5662 0 : tree r;
5663 :
5664 0 : if (!is_nondependent_constant_expression (t))
5665 : {
5666 0 : if (TREE_OVERFLOW_P (t))
5667 : {
5668 0 : t = build_nop (TREE_TYPE (t), t);
5669 0 : TREE_CONSTANT (t) = false;
5670 : }
5671 0 : return t;
5672 : }
5673 0 : else if (CONSTANT_CLASS_P (t))
5674 : /* No caching or evaluation needed. */
5675 : return t;
5676 :
5677 0 : if (manifestly_const_eval)
5678 0 : return cxx_eval_outermost_constant_expr (t, true, true, true, false, decl);
5679 :
5680 0 : if (cv_cache == NULL)
5681 0 : cv_cache = hash_map<tree, tree>::create_ggc (101);
5682 0 : if (tree *cached = cv_cache->get (t))
5683 : {
5684 0 : r = *cached;
5685 0 : if (r != t)
5686 : {
5687 : // Faisal: commenting this out as not sure if it's needed and it's
5688 : // huge r = break_out_target_exprs (r, /*clear_loc*/true);
5689 0 : protected_set_expr_location (r, EXPR_LOCATION (t));
5690 : }
5691 : return r;
5692 : }
5693 :
5694 : /* Don't evaluate an unevaluated operand. */
5695 0 : if (cp_unevaluated_operand)
5696 : return t;
5697 :
5698 0 : uid_sensitive_constexpr_evaluation_checker c;
5699 0 : r = cxx_eval_outermost_constant_expr (t, true, true, false, false, decl);
5700 0 : gcc_checking_assert (
5701 : r == t || CONVERT_EXPR_P (t) || TREE_CODE (t) == VIEW_CONVERT_EXPR
5702 : || (TREE_CONSTANT (t) && !TREE_CONSTANT (r)) || !rs_tree_equal (r, t));
5703 0 : if (!c.evaluation_restricted_p ())
5704 0 : cv_cache->put (t, r);
5705 : return r;
5706 : }
5707 :
5708 : // forked from gcc/cp/constexpr.cc
5709 :
5710 : bool
5711 0 : potential_constant_expression (tree t)
5712 : {
5713 0 : return potential_constant_expression_1 (t, false, true, false, tf_none);
5714 : }
5715 :
5716 : /* Data structure for passing data from potential_constant_expression_1
5717 : to check_for_return_continue via cp_walk_tree. */
5718 : struct check_for_return_continue_data
5719 : {
5720 : hash_set<tree> *pset;
5721 : tree continue_stmt;
5722 : tree break_stmt;
5723 : };
5724 :
5725 : /* Helper function for potential_constant_expression_1 SWITCH_STMT handling,
5726 : called through cp_walk_tree. Return the first RETURN_EXPR found, or note
5727 : the first CONTINUE_STMT and/or BREAK_STMT if RETURN_EXPR is not found. */
5728 : static tree
5729 0 : check_for_return_continue (tree *tp, int *walk_subtrees, void *data)
5730 : {
5731 0 : tree t = *tp, s, b;
5732 0 : check_for_return_continue_data *d = (check_for_return_continue_data *) data;
5733 0 : switch (TREE_CODE (t))
5734 : {
5735 : case RETURN_EXPR:
5736 : return t;
5737 :
5738 0 : case CONTINUE_STMT:
5739 0 : if (d->continue_stmt == NULL_TREE)
5740 0 : d->continue_stmt = t;
5741 : break;
5742 :
5743 0 : case BREAK_STMT:
5744 0 : if (d->break_stmt == NULL_TREE)
5745 0 : d->break_stmt = t;
5746 : break;
5747 :
5748 : #define RECUR(x) \
5749 : if (tree r = rs_walk_tree (&x, check_for_return_continue, data, d->pset)) \
5750 : return r
5751 :
5752 : /* For loops, walk subtrees manually, so that continue stmts found
5753 : inside of the bodies of the loops are ignored. */
5754 :
5755 0 : case WHILE_STMT:
5756 0 : *walk_subtrees = 0;
5757 0 : RECUR (WHILE_COND (t));
5758 0 : s = d->continue_stmt;
5759 0 : b = d->break_stmt;
5760 0 : RECUR (WHILE_BODY (t));
5761 0 : d->continue_stmt = s;
5762 0 : d->break_stmt = b;
5763 0 : break;
5764 :
5765 0 : case FOR_STMT:
5766 0 : *walk_subtrees = 0;
5767 0 : RECUR (FOR_INIT_STMT (t));
5768 0 : RECUR (FOR_COND (t));
5769 0 : RECUR (FOR_EXPR (t));
5770 0 : s = d->continue_stmt;
5771 0 : b = d->break_stmt;
5772 0 : RECUR (FOR_BODY (t));
5773 0 : d->continue_stmt = s;
5774 0 : d->break_stmt = b;
5775 0 : break;
5776 :
5777 0 : case RANGE_FOR_STMT:
5778 0 : *walk_subtrees = 0;
5779 0 : RECUR (RANGE_FOR_EXPR (t));
5780 0 : s = d->continue_stmt;
5781 0 : b = d->break_stmt;
5782 0 : RECUR (RANGE_FOR_BODY (t));
5783 0 : d->continue_stmt = s;
5784 0 : d->break_stmt = b;
5785 0 : break;
5786 :
5787 0 : case SWITCH_STMT:
5788 0 : *walk_subtrees = 0;
5789 0 : RECUR (SWITCH_STMT_COND (t));
5790 0 : b = d->break_stmt;
5791 0 : RECUR (SWITCH_STMT_BODY (t));
5792 0 : d->break_stmt = b;
5793 0 : break;
5794 : #undef RECUR
5795 :
5796 : case STATEMENT_LIST:
5797 : case CONSTRUCTOR:
5798 : break;
5799 :
5800 0 : default:
5801 0 : if (!EXPR_P (t))
5802 0 : *walk_subtrees = 0;
5803 : break;
5804 : }
5805 :
5806 : return NULL_TREE;
5807 : }
5808 :
5809 : /* Returns the namespace that contains DECL, whether directly or
5810 : indirectly. */
5811 :
5812 : tree
5813 0 : decl_namespace_context (tree decl)
5814 : {
5815 0 : while (1)
5816 : {
5817 0 : if (TREE_CODE (decl) == NAMESPACE_DECL)
5818 0 : return decl;
5819 0 : else if (TYPE_P (decl))
5820 0 : decl = CP_DECL_CONTEXT (TYPE_MAIN_DECL (decl));
5821 : else
5822 0 : decl = CP_DECL_CONTEXT (decl);
5823 : }
5824 : }
5825 :
5826 : /* Returns true if DECL is in the std namespace. */
5827 :
5828 : bool
5829 0 : decl_in_std_namespace_p (tree decl)
5830 : {
5831 0 : while (decl)
5832 : {
5833 0 : decl = decl_namespace_context (decl);
5834 0 : if (DECL_NAMESPACE_STD_P (decl))
5835 : return true;
5836 : /* Allow inline namespaces inside of std namespace, e.g. with
5837 : --enable-symvers=gnu-versioned-namespace std::forward would be
5838 : actually std::_8::forward. */
5839 0 : if (!DECL_NAMESPACE_INLINE_P (decl))
5840 : return false;
5841 0 : decl = CP_DECL_CONTEXT (decl);
5842 : }
5843 : return false;
5844 : }
5845 :
5846 : /* Return true if FNDECL is std::construct_at. */
5847 :
5848 : static inline bool
5849 : is_std_construct_at (tree fndecl)
5850 : {
5851 : if (!decl_in_std_namespace_p (fndecl))
5852 : return false;
5853 :
5854 : tree name = DECL_NAME (fndecl);
5855 : return name && id_equal (name, "construct_at");
5856 : }
5857 :
5858 : /* Return true if FNDECL is __dynamic_cast. */
5859 :
5860 : static inline bool
5861 : cxx_dynamic_cast_fn_p (tree fndecl)
5862 : {
5863 : return (id_equal (DECL_NAME (fndecl), "__dynamic_cast")
5864 : && CP_DECL_CONTEXT (fndecl) == global_namespace);
5865 : }
5866 :
5867 : /* Return true if FNDECL is std::allocator<T>::{,de}allocate. */
5868 :
5869 : static inline bool
5870 : is_std_allocator_allocate (tree fndecl)
5871 : {
5872 : tree name = DECL_NAME (fndecl);
5873 : if (name == NULL_TREE
5874 : || !(id_equal (name, "allocate") || id_equal (name, "deallocate")))
5875 : return false;
5876 :
5877 : tree ctx = DECL_CONTEXT (fndecl);
5878 : if (ctx == NULL_TREE || !CLASS_TYPE_P (ctx) || !TYPE_MAIN_DECL (ctx))
5879 : return false;
5880 :
5881 : tree decl = TYPE_MAIN_DECL (ctx);
5882 : name = DECL_NAME (decl);
5883 : if (name == NULL_TREE || !id_equal (name, "allocator"))
5884 : return false;
5885 :
5886 : return decl_in_std_namespace_p (decl);
5887 : }
5888 :
5889 : /* Overload for the above taking rust_constexpr_call*. */
5890 :
5891 : static inline bool
5892 : is_std_allocator_allocate (const rust_constexpr_call *call)
5893 : {
5894 : return (call && call->fundef
5895 : && is_std_allocator_allocate (call->fundef->decl));
5896 : }
5897 :
5898 : /* Return true if T denotes a potentially constant expression. Issue
5899 : diagnostic as appropriate under control of FLAGS. If WANT_RVAL is true,
5900 : an lvalue-rvalue conversion is implied. If NOW is true, we want to
5901 : consider the expression in the current context, independent of constexpr
5902 : substitution.
5903 :
5904 : C++0x [expr.const] used to say
5905 :
5906 : 6 An expression is a potential constant expression if it is
5907 : a constant expression where all occurrences of function
5908 : parameters are replaced by arbitrary constant expressions
5909 : of the appropriate type.
5910 :
5911 : 2 A conditional expression is a constant expression unless it
5912 : involves one of the following as a potentially evaluated
5913 : subexpression (3.2), but subexpressions of logical AND (5.14),
5914 : logical OR (5.15), and conditional (5.16) operations that are
5915 : not evaluated are not considered. */
5916 :
5917 : static bool
5918 0 : potential_constant_expression_1 (tree t, bool want_rval, bool strict, bool now,
5919 : tsubst_flags_t flags, tree *jump_target)
5920 : {
5921 : #define RECUR(T, RV) \
5922 : potential_constant_expression_1 ((T), (RV), strict, now, flags, jump_target)
5923 :
5924 0 : enum
5925 : {
5926 : any = false,
5927 : rval = true
5928 : };
5929 0 : int i;
5930 0 : tree tmp;
5931 :
5932 0 : if (t == error_mark_node)
5933 : return false;
5934 0 : if (t == NULL_TREE)
5935 : return true;
5936 0 : location_t loc = rs_expr_loc_or_input_loc (t);
5937 :
5938 0 : if (*jump_target)
5939 : /* If we are jumping, ignore everything. This is simpler than the
5940 : cxx_eval_constant_expression handling because we only need to be
5941 : conservatively correct, and we don't necessarily have a constant value
5942 : available, so we don't bother with switch tracking. */
5943 : return true;
5944 :
5945 0 : if (TREE_THIS_VOLATILE (t) && want_rval)
5946 : {
5947 0 : if (flags & tf_error)
5948 0 : error_at (loc,
5949 : "lvalue-to-rvalue conversion of a volatile lvalue "
5950 : "%qE with type %qT",
5951 0 : t, TREE_TYPE (t));
5952 : return false;
5953 : }
5954 0 : if (CONSTANT_CLASS_P (t))
5955 : return true;
5956 0 : if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_TYPED)
5957 0 : && TREE_TYPE (t) == error_mark_node)
5958 : return false;
5959 :
5960 0 : switch (TREE_CODE (t))
5961 : {
5962 : case FUNCTION_DECL:
5963 : case OVERLOAD:
5964 : case LABEL_DECL:
5965 : case CASE_LABEL_EXPR:
5966 : case PREDICT_EXPR:
5967 : case CONST_DECL:
5968 : case IDENTIFIER_NODE:
5969 : /* We can see a FIELD_DECL in a pointer-to-member expression. */
5970 : case FIELD_DECL:
5971 : case RESULT_DECL:
5972 : case PLACEHOLDER_EXPR:
5973 : case STATIC_ASSERT:
5974 : return true;
5975 :
5976 0 : case RETURN_EXPR:
5977 0 : if (!RECUR (TREE_OPERAND (t, 0), any))
5978 : return false;
5979 : /* FALLTHROUGH */
5980 :
5981 0 : case BREAK_STMT:
5982 0 : case CONTINUE_STMT:
5983 0 : *jump_target = t;
5984 0 : return true;
5985 :
5986 0 : case PARM_DECL:
5987 0 : if (now && want_rval)
5988 : {
5989 0 : tree type = TREE_TYPE (t);
5990 0 : if (is_really_empty_class (type, /*ignore_vptr*/ false))
5991 : /* An empty class has no data to read. */
5992 : return true;
5993 0 : if (flags & tf_error)
5994 0 : error ("%qE is not a constant expression", t);
5995 : return false;
5996 : }
5997 : return true;
5998 :
5999 0 : case CALL_EXPR:
6000 : /* -- an invocation of a function other than a constexpr function
6001 : or a constexpr constructor. */
6002 0 : {
6003 0 : tree fun = get_function_named_in_call (t);
6004 0 : const int nargs = call_expr_nargs (t);
6005 0 : i = 0;
6006 :
6007 0 : if (fun == NULL_TREE)
6008 : {
6009 : /* Reset to allow the function to continue past the end
6010 : of the block below. Otherwise return early. */
6011 0 : bool bail = true;
6012 :
6013 0 : if (TREE_CODE (t) == CALL_EXPR && CALL_EXPR_FN (t) == NULL_TREE)
6014 0 : switch (CALL_EXPR_IFN (t))
6015 : {
6016 : /* These should be ignored, they are optimized away from
6017 : constexpr functions. */
6018 : case IFN_UBSAN_NULL:
6019 : case IFN_UBSAN_BOUNDS:
6020 : case IFN_UBSAN_VPTR:
6021 : case IFN_FALLTHROUGH:
6022 : return true;
6023 :
6024 : case IFN_ADD_OVERFLOW:
6025 : case IFN_SUB_OVERFLOW:
6026 : case IFN_MUL_OVERFLOW:
6027 : case IFN_LAUNDER:
6028 : case IFN_VEC_CONVERT:
6029 : bail = false;
6030 : break;
6031 :
6032 : default:
6033 : break;
6034 : }
6035 :
6036 : if (bail)
6037 : {
6038 : /* fold_call_expr can't do anything with IFN calls. */
6039 0 : if (flags & tf_error)
6040 0 : error_at (loc, "call to internal function %qE", t);
6041 : return false;
6042 : }
6043 : }
6044 :
6045 0 : if (fun && is_overloaded_fn (fun))
6046 : {
6047 0 : if (TREE_CODE (fun) == FUNCTION_DECL)
6048 : {
6049 0 : if (builtin_valid_in_constant_expr_p (fun))
6050 : return true;
6051 0 : if (!maybe_constexpr_fn (fun)
6052 : /* Allow any built-in function; if the expansion
6053 : isn't constant, we'll deal with that then. */
6054 0 : && !fndecl_built_in_p (fun)
6055 : /* In C++20, replaceable global allocation functions
6056 : are constant expressions. */
6057 0 : && (/* !cxx_replaceable_global_alloc_fn (fun)
6058 0 : ||*/ TREE_CODE (t) != CALL_EXPR
6059 0 : || (!CALL_FROM_NEW_OR_DELETE_P (t)
6060 0 : && (current_function_decl == NULL_TREE
6061 : /*|| !is_std_allocator_allocate(current_function_decl)*/)))
6062 : /* Allow placement new in std::construct_at. */
6063 0 : && (/*!cxx_placement_new_fn (fun)
6064 : ||*/ TREE_CODE (t) != CALL_EXPR
6065 0 : || current_function_decl == NULL_TREE
6066 : /*|| !is_std_construct_at (current_function_decl)*/)
6067 : /* && !cxx_dynamic_cast_fn_p (fun)*/)
6068 : {
6069 0 : if (flags & tf_error)
6070 : {
6071 0 : error_at (loc, "call to non-%<constexpr%> function %qD",
6072 : fun);
6073 0 : explain_invalid_constexpr_fn (fun);
6074 : }
6075 : return false;
6076 : }
6077 : /* A call to a non-static member function takes the address
6078 : of the object as the first argument. But in a constant
6079 : expression the address will be folded away, so look
6080 : through it now. */
6081 0 : if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fun)
6082 0 : && !DECL_CONSTRUCTOR_P (fun))
6083 : {
6084 0 : tree x = CALL_EXPR_ARG (t, 0);
6085 :
6086 : /* Don't require an immediately constant value, as
6087 : constexpr substitution might not use the value. */
6088 0 : bool sub_now = false;
6089 0 : if (!potential_constant_expression_1 (x, rval, strict,
6090 : sub_now, flags,
6091 : jump_target))
6092 : return false;
6093 : i = 1;
6094 : }
6095 : }
6096 : else
6097 : {
6098 0 : if (!RECUR (fun, true))
6099 : return false;
6100 0 : fun = get_first_fn (fun);
6101 : }
6102 0 : fun = DECL_ORIGIN (fun);
6103 : }
6104 0 : else if (fun)
6105 : {
6106 0 : if (RECUR (fun, rval))
6107 : /* Might end up being a constant function pointer. */;
6108 : else
6109 : return false;
6110 : }
6111 0 : for (; i < nargs; ++i)
6112 : {
6113 0 : tree x = CALL_EXPR_ARG (t, i);
6114 : /* In a template, reference arguments haven't been converted to
6115 : REFERENCE_TYPE and we might not even know if the parameter
6116 : is a reference, so accept lvalue constants too. */
6117 0 : bool rv = rval;
6118 : /* Don't require an immediately constant value, as constexpr
6119 : substitution might not use the value of the argument. */
6120 0 : bool sub_now = false;
6121 0 : if (!potential_constant_expression_1 (x, rv, strict, sub_now, flags,
6122 : jump_target))
6123 : return false;
6124 : }
6125 : return true;
6126 : }
6127 :
6128 0 : case NON_LVALUE_EXPR:
6129 : /* -- an lvalue-to-rvalue conversion (4.1) unless it is applied to
6130 : -- an lvalue of integral type that refers to a non-volatile
6131 : const variable or static data member initialized with
6132 : constant expressions, or
6133 :
6134 : -- an lvalue of literal type that refers to non-volatile
6135 : object defined with constexpr, or that refers to a
6136 : sub-object of such an object; */
6137 0 : return RECUR (TREE_OPERAND (t, 0), rval);
6138 :
6139 0 : case VAR_DECL:
6140 0 : if (DECL_HAS_VALUE_EXPR_P (t))
6141 : {
6142 0 : return RECUR (DECL_VALUE_EXPR (t), rval);
6143 : }
6144 0 : if (want_rval && !var_in_maybe_constexpr_fn (t)
6145 0 : && !decl_maybe_constant_var_p (t)
6146 0 : && (strict || !RS_TYPE_CONST_NON_VOLATILE_P (TREE_TYPE (t))
6147 0 : || (DECL_INITIAL (t)
6148 0 : && !DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (t)))
6149 0 : && COMPLETE_TYPE_P (TREE_TYPE (t))
6150 0 : && !is_really_empty_class (TREE_TYPE (t), /*ignore_vptr*/ false))
6151 : {
6152 0 : if (flags & tf_error)
6153 0 : non_const_var_error (loc, t);
6154 : return false;
6155 : }
6156 : return true;
6157 :
6158 : /* FALLTHRU */
6159 0 : case NOP_EXPR:
6160 0 : case CONVERT_EXPR:
6161 0 : case VIEW_CONVERT_EXPR:
6162 : /* -- a reinterpret_cast. FIXME not implemented, and this rule
6163 : may change to something more specific to type-punning (DR 1312). */
6164 0 : {
6165 0 : tree from = TREE_OPERAND (t, 0);
6166 0 : if (location_wrapper_p (t))
6167 : return (RECUR (from, want_rval));
6168 0 : if (INDIRECT_TYPE_P (TREE_TYPE (t)))
6169 : {
6170 0 : STRIP_ANY_LOCATION_WRAPPER (from);
6171 0 : if (TREE_CODE (from) == INTEGER_CST && !integer_zerop (from))
6172 : {
6173 0 : if (flags & tf_error)
6174 0 : error_at (loc,
6175 : "%<reinterpret_cast%> from integer to pointer");
6176 : return false;
6177 : }
6178 : }
6179 0 : return (RECUR (from, TREE_CODE (t) != VIEW_CONVERT_EXPR));
6180 : }
6181 :
6182 0 : case ADDR_EXPR:
6183 : /* -- a unary operator & that is applied to an lvalue that
6184 : designates an object with thread or automatic storage
6185 : duration; */
6186 0 : t = TREE_OPERAND (t, 0);
6187 :
6188 0 : if (TREE_CODE (t) == OFFSET_REF && PTRMEM_OK_P (t))
6189 : /* A pointer-to-member constant. */
6190 : return true;
6191 :
6192 : #if 0
6193 : /* FIXME adjust when issue 1197 is fully resolved. For now don't do
6194 : any checking here, as we might dereference the pointer later. If
6195 : we remove this code, also remove check_automatic_or_tls. */
6196 : i = check_automatic_or_tls (t);
6197 : if (i == ck_ok)
6198 : return true;
6199 : if (i == ck_bad)
6200 : {
6201 : if (flags & tf_error)
6202 : error ("address-of an object %qE with thread local or "
6203 : "automatic storage is not a constant expression", t);
6204 : return false;
6205 : }
6206 : #endif
6207 : return RECUR (t, any);
6208 :
6209 0 : case COMPONENT_REF:
6210 : /* -- a class member access unless its postfix-expression is
6211 : of literal type or of pointer to literal type. */
6212 : /* This test would be redundant, as it follows from the
6213 : postfix-expression being a potential constant expression. */
6214 0 : if (type_unknown_p (t))
6215 : return true;
6216 0 : if (is_overloaded_fn (t))
6217 : /* In a template, a COMPONENT_REF of a function expresses ob.fn(),
6218 : which uses ob as an lvalue. */
6219 0 : want_rval = false;
6220 0 : gcc_fallthrough ();
6221 :
6222 0 : case REALPART_EXPR:
6223 0 : case IMAGPART_EXPR:
6224 0 : case BIT_FIELD_REF:
6225 0 : return RECUR (TREE_OPERAND (t, 0), want_rval);
6226 :
6227 0 : case INDIRECT_REF:
6228 0 : {
6229 0 : tree x = TREE_OPERAND (t, 0);
6230 0 : STRIP_NOPS (x);
6231 0 : return RECUR (x, rval);
6232 : }
6233 :
6234 0 : case STATEMENT_LIST:
6235 0 : for (tree stmt : tsi_range (t))
6236 0 : if (!RECUR (stmt, any))
6237 0 : return false;
6238 : return true;
6239 :
6240 0 : case MODIFY_EXPR:
6241 0 : if (!RECUR (TREE_OPERAND (t, 0), any))
6242 : return false;
6243 : /* Just ignore clobbers. */
6244 0 : if (TREE_CLOBBER_P (TREE_OPERAND (t, 1)))
6245 : return true;
6246 0 : if (!RECUR (TREE_OPERAND (t, 1), rval))
6247 : return false;
6248 : return true;
6249 :
6250 0 : case FOR_STMT:
6251 0 : if (!RECUR (FOR_INIT_STMT (t), any))
6252 : return false;
6253 0 : tmp = FOR_COND (t);
6254 0 : if (!RECUR (tmp, rval))
6255 : return false;
6256 0 : if (tmp)
6257 : {
6258 0 : tmp = cxx_eval_outermost_constant_expr (tmp, true);
6259 : /* If we couldn't evaluate the condition, it might not ever be
6260 : true. */
6261 0 : if (!integer_onep (tmp))
6262 : {
6263 : /* Before returning true, check if the for body can contain
6264 : a return. */
6265 0 : hash_set<tree> pset;
6266 0 : check_for_return_continue_data data
6267 0 : = {&pset, NULL_TREE, NULL_TREE};
6268 0 : if (tree ret_expr
6269 0 : = rs_walk_tree (&FOR_BODY (t), check_for_return_continue,
6270 : &data, &pset))
6271 0 : *jump_target = ret_expr;
6272 0 : return true;
6273 0 : }
6274 : }
6275 0 : if (!RECUR (FOR_EXPR (t), any))
6276 : return false;
6277 0 : if (!RECUR (FOR_BODY (t), any))
6278 : return false;
6279 0 : if (breaks (jump_target) || continues (jump_target))
6280 0 : *jump_target = NULL_TREE;
6281 : return true;
6282 :
6283 0 : case WHILE_STMT:
6284 0 : tmp = WHILE_COND (t);
6285 0 : if (!RECUR (tmp, rval))
6286 : return false;
6287 :
6288 0 : tmp = cxx_eval_outermost_constant_expr (tmp, true);
6289 : /* If we couldn't evaluate the condition, it might not ever be true. */
6290 0 : if (!integer_onep (tmp))
6291 : {
6292 : /* Before returning true, check if the while body can contain
6293 : a return. */
6294 0 : hash_set<tree> pset;
6295 0 : check_for_return_continue_data data = {&pset, NULL_TREE, NULL_TREE};
6296 0 : if (tree ret_expr
6297 0 : = rs_walk_tree (&WHILE_BODY (t), check_for_return_continue, &data,
6298 : &pset))
6299 0 : *jump_target = ret_expr;
6300 0 : return true;
6301 0 : }
6302 0 : if (!RECUR (WHILE_BODY (t), any))
6303 : return false;
6304 0 : if (breaks (jump_target) || continues (jump_target))
6305 0 : *jump_target = NULL_TREE;
6306 : return true;
6307 :
6308 0 : case SWITCH_STMT:
6309 0 : if (!RECUR (SWITCH_STMT_COND (t), rval))
6310 : return false;
6311 : /* FIXME we don't check SWITCH_STMT_BODY currently, because even
6312 : unreachable labels would be checked and it is enough if there is
6313 : a single switch cond value for which it is a valid constant
6314 : expression. We need to check if there are any RETURN_EXPRs
6315 : or CONTINUE_STMTs inside of the body though, as in that case
6316 : we need to set *jump_target. */
6317 : else
6318 : {
6319 0 : hash_set<tree> pset;
6320 0 : check_for_return_continue_data data = {&pset, NULL_TREE, NULL_TREE};
6321 0 : if (tree ret_expr
6322 0 : = rs_walk_tree (&SWITCH_STMT_BODY (t), check_for_return_continue,
6323 : &data, &pset))
6324 : /* The switch might return. */
6325 0 : *jump_target = ret_expr;
6326 0 : else if (data.continue_stmt)
6327 : /* The switch can't return, but might continue. */
6328 0 : *jump_target = data.continue_stmt;
6329 0 : }
6330 0 : return true;
6331 :
6332 0 : case DYNAMIC_CAST_EXPR:
6333 0 : case PSEUDO_DTOR_EXPR:
6334 0 : case NEW_EXPR:
6335 0 : case VEC_NEW_EXPR:
6336 0 : case DELETE_EXPR:
6337 0 : case VEC_DELETE_EXPR:
6338 0 : case THROW_EXPR:
6339 0 : case OMP_PARALLEL:
6340 0 : case OMP_TASK:
6341 0 : case OMP_FOR:
6342 0 : case OMP_SIMD:
6343 0 : case OMP_DISTRIBUTE:
6344 0 : case OMP_TASKLOOP:
6345 0 : case OMP_LOOP:
6346 0 : case OMP_TEAMS:
6347 0 : case OMP_TARGET_DATA:
6348 0 : case OMP_TARGET:
6349 0 : case OMP_SECTIONS:
6350 0 : case OMP_ORDERED:
6351 0 : case OMP_CRITICAL:
6352 0 : case OMP_SINGLE:
6353 0 : case OMP_SECTION:
6354 0 : case OMP_MASTER:
6355 0 : case OMP_MASKED:
6356 0 : case OMP_TASKGROUP:
6357 0 : case OMP_TARGET_UPDATE:
6358 0 : case OMP_TARGET_ENTER_DATA:
6359 0 : case OMP_TARGET_EXIT_DATA:
6360 0 : case OMP_ATOMIC:
6361 0 : case OMP_ATOMIC_READ:
6362 0 : case OMP_ATOMIC_CAPTURE_OLD:
6363 0 : case OMP_ATOMIC_CAPTURE_NEW:
6364 0 : case OMP_DEPOBJ:
6365 0 : case OACC_PARALLEL:
6366 0 : case OACC_KERNELS:
6367 0 : case OACC_SERIAL:
6368 0 : case OACC_DATA:
6369 0 : case OACC_HOST_DATA:
6370 0 : case OACC_LOOP:
6371 0 : case OACC_CACHE:
6372 0 : case OACC_DECLARE:
6373 0 : case OACC_ENTER_DATA:
6374 0 : case OACC_EXIT_DATA:
6375 0 : case OACC_UPDATE:
6376 : /* GCC internal stuff. */
6377 0 : case VA_ARG_EXPR:
6378 0 : case TRANSACTION_EXPR:
6379 0 : case AT_ENCODE_EXPR:
6380 :
6381 0 : if (flags & tf_error)
6382 0 : error_at (loc, "expression %qE is not a constant expression", t);
6383 : return false;
6384 :
6385 0 : case ASM_EXPR:
6386 0 : if (flags & tf_error)
6387 0 : inline_asm_in_constexpr_error (loc);
6388 : return false;
6389 :
6390 : case OBJ_TYPE_REF:
6391 : return true;
6392 :
6393 0 : case POINTER_DIFF_EXPR:
6394 0 : case MINUS_EXPR:
6395 0 : want_rval = true;
6396 0 : goto binary;
6397 :
6398 0 : case LT_EXPR:
6399 0 : case LE_EXPR:
6400 0 : case GT_EXPR:
6401 0 : case GE_EXPR:
6402 0 : case EQ_EXPR:
6403 0 : case NE_EXPR:
6404 0 : case SPACESHIP_EXPR:
6405 0 : want_rval = true;
6406 0 : goto binary;
6407 :
6408 0 : case PREINCREMENT_EXPR:
6409 0 : case POSTINCREMENT_EXPR:
6410 0 : case PREDECREMENT_EXPR:
6411 0 : case POSTDECREMENT_EXPR:
6412 0 : goto unary;
6413 :
6414 0 : case BIT_NOT_EXPR:
6415 : /* A destructor. */
6416 0 : if (TYPE_P (TREE_OPERAND (t, 0)))
6417 : return true;
6418 : /* fall through. */
6419 :
6420 0 : case CONJ_EXPR:
6421 0 : case SAVE_EXPR:
6422 0 : case FIX_TRUNC_EXPR:
6423 0 : case FLOAT_EXPR:
6424 0 : case NEGATE_EXPR:
6425 0 : case ABS_EXPR:
6426 0 : case ABSU_EXPR:
6427 0 : case TRUTH_NOT_EXPR:
6428 0 : case FIXED_CONVERT_EXPR:
6429 0 : case UNARY_PLUS_EXPR:
6430 0 : case UNARY_LEFT_FOLD_EXPR:
6431 0 : case UNARY_RIGHT_FOLD_EXPR:
6432 0 : unary:
6433 0 : return RECUR (TREE_OPERAND (t, 0), rval);
6434 :
6435 0 : case BIND_EXPR:
6436 0 : return RECUR (BIND_EXPR_BODY (t), want_rval);
6437 :
6438 0 : case CLEANUP_POINT_EXPR:
6439 0 : case EXPR_STMT:
6440 0 : case PAREN_EXPR:
6441 : /* For convenience. */
6442 0 : case LOOP_EXPR:
6443 0 : case EXIT_EXPR:
6444 0 : return RECUR (TREE_OPERAND (t, 0), want_rval);
6445 :
6446 0 : case DECL_EXPR:
6447 0 : tmp = DECL_EXPR_DECL (t);
6448 0 : if (VAR_P (tmp) && !DECL_ARTIFICIAL (tmp))
6449 : {
6450 0 : if (RS_DECL_THREAD_LOCAL_P (tmp))
6451 : {
6452 0 : if (flags & tf_error)
6453 0 : error_at (DECL_SOURCE_LOCATION (tmp),
6454 : "%qD declared "
6455 : "%<thread_local%> in %<constexpr%> context",
6456 : tmp);
6457 : return false;
6458 : }
6459 0 : else if (TREE_STATIC (tmp))
6460 : {
6461 0 : if (flags & tf_error)
6462 0 : error_at (DECL_SOURCE_LOCATION (tmp),
6463 : "%qD declared "
6464 : "%<static%> in %<constexpr%> context",
6465 : tmp);
6466 : return false;
6467 : }
6468 0 : else if (!check_for_uninitialized_const_var (
6469 : tmp, /*constexpr_context_p=*/true, flags))
6470 : return false;
6471 : }
6472 : return RECUR (tmp, want_rval);
6473 :
6474 0 : case TRY_FINALLY_EXPR:
6475 0 : return (RECUR (TREE_OPERAND (t, 0), want_rval)
6476 0 : && RECUR (TREE_OPERAND (t, 1), any));
6477 :
6478 0 : case SCOPE_REF:
6479 0 : return RECUR (TREE_OPERAND (t, 1), want_rval);
6480 :
6481 0 : case TARGET_EXPR:
6482 0 : if (!TARGET_EXPR_DIRECT_INIT_P (t) && !literal_type_p (TREE_TYPE (t)))
6483 : {
6484 0 : if (flags & tf_error)
6485 : {
6486 0 : auto_diagnostic_group d;
6487 0 : error_at (loc,
6488 : "temporary of non-literal type %qT in a "
6489 : "constant expression",
6490 0 : TREE_TYPE (t));
6491 0 : explain_non_literal_class (TREE_TYPE (t));
6492 0 : }
6493 : return false;
6494 : }
6495 : /* FALLTHRU */
6496 0 : case INIT_EXPR:
6497 0 : return RECUR (TREE_OPERAND (t, 1), rval);
6498 :
6499 0 : case CONSTRUCTOR:
6500 0 : {
6501 0 : vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (t);
6502 0 : constructor_elt *ce;
6503 0 : for (i = 0; vec_safe_iterate (v, i, &ce); ++i)
6504 0 : if (!RECUR (ce->value, want_rval))
6505 : return false;
6506 : return true;
6507 : }
6508 :
6509 0 : case TREE_LIST:
6510 0 : {
6511 0 : gcc_assert (TREE_PURPOSE (t) == NULL_TREE || DECL_P (TREE_PURPOSE (t)));
6512 0 : if (!RECUR (TREE_VALUE (t), want_rval))
6513 : return false;
6514 0 : if (TREE_CHAIN (t) == NULL_TREE)
6515 : return true;
6516 0 : return RECUR (TREE_CHAIN (t), want_rval);
6517 : }
6518 :
6519 0 : case TRUNC_DIV_EXPR:
6520 0 : case CEIL_DIV_EXPR:
6521 0 : case FLOOR_DIV_EXPR:
6522 0 : case ROUND_DIV_EXPR:
6523 0 : case TRUNC_MOD_EXPR:
6524 0 : case CEIL_MOD_EXPR:
6525 0 : case ROUND_MOD_EXPR:
6526 0 : {
6527 0 : tree denom = TREE_OPERAND (t, 1);
6528 0 : if (!RECUR (denom, rval))
6529 : return false;
6530 : /* We can't call cxx_eval_outermost_constant_expr on an expression
6531 : that hasn't been through instantiate_non_dependent_expr yet. */
6532 0 : denom = cxx_eval_outermost_constant_expr (denom, true);
6533 0 : if (integer_zerop (denom))
6534 : {
6535 0 : if (flags & tf_error)
6536 0 : error ("division by zero is not a constant expression");
6537 : return false;
6538 : }
6539 : else
6540 : {
6541 0 : want_rval = true;
6542 0 : return RECUR (TREE_OPERAND (t, 0), want_rval);
6543 : }
6544 : }
6545 :
6546 0 : case COMPOUND_EXPR:
6547 0 : {
6548 : /* check_return_expr sometimes wraps a TARGET_EXPR in a
6549 : COMPOUND_EXPR; don't get confused. */
6550 0 : tree op0 = TREE_OPERAND (t, 0);
6551 0 : tree op1 = TREE_OPERAND (t, 1);
6552 0 : STRIP_NOPS (op1);
6553 0 : if (TREE_CODE (op0) == TARGET_EXPR && op1 == TARGET_EXPR_SLOT (op0))
6554 : return RECUR (op0, want_rval);
6555 : else
6556 0 : goto binary;
6557 : }
6558 :
6559 : /* If the first operand is the non-short-circuit constant, look at
6560 : the second operand; otherwise we only care about the first one for
6561 : potentiality. */
6562 0 : case TRUTH_AND_EXPR:
6563 0 : case TRUTH_ANDIF_EXPR:
6564 0 : tmp = boolean_true_node;
6565 0 : goto truth;
6566 0 : case TRUTH_OR_EXPR:
6567 0 : case TRUTH_ORIF_EXPR:
6568 0 : tmp = boolean_false_node;
6569 0 : truth:
6570 0 : {
6571 0 : tree op0 = TREE_OPERAND (t, 0);
6572 0 : tree op1 = TREE_OPERAND (t, 1);
6573 0 : if (!RECUR (op0, rval))
6574 : return false;
6575 0 : if (!(flags & tf_error) && RECUR (op1, rval))
6576 : /* When quiet, try to avoid expensive trial evaluation by first
6577 : checking potentiality of the second operand. */
6578 : return true;
6579 0 : op0 = cxx_eval_outermost_constant_expr (op0, true);
6580 0 : if (tree_int_cst_equal (op0, tmp))
6581 0 : return (flags & tf_error) ? RECUR (op1, rval) : false;
6582 : else
6583 : return true;
6584 : }
6585 :
6586 : case PLUS_EXPR:
6587 : case MULT_EXPR:
6588 : case POINTER_PLUS_EXPR:
6589 : case RDIV_EXPR:
6590 : case EXACT_DIV_EXPR:
6591 : case MIN_EXPR:
6592 : case MAX_EXPR:
6593 : case LSHIFT_EXPR:
6594 : case RSHIFT_EXPR:
6595 : case LROTATE_EXPR:
6596 : case RROTATE_EXPR:
6597 : case BIT_IOR_EXPR:
6598 : case BIT_XOR_EXPR:
6599 : case BIT_AND_EXPR:
6600 : case TRUTH_XOR_EXPR:
6601 : case UNORDERED_EXPR:
6602 : case ORDERED_EXPR:
6603 : case UNLT_EXPR:
6604 : case UNLE_EXPR:
6605 : case UNGT_EXPR:
6606 : case UNGE_EXPR:
6607 : case UNEQ_EXPR:
6608 : case LTGT_EXPR:
6609 : case RANGE_EXPR:
6610 : case COMPLEX_EXPR:
6611 0 : want_rval = true;
6612 : /* Fall through. */
6613 0 : case ARRAY_REF:
6614 0 : case ARRAY_RANGE_REF:
6615 0 : case MEMBER_REF:
6616 0 : case DOTSTAR_EXPR:
6617 0 : case MEM_REF:
6618 0 : case BINARY_LEFT_FOLD_EXPR:
6619 0 : case BINARY_RIGHT_FOLD_EXPR:
6620 0 : binary:
6621 0 : for (i = 0; i < 2; ++i)
6622 0 : if (!RECUR (TREE_OPERAND (t, i), want_rval))
6623 : return false;
6624 : return true;
6625 :
6626 : case VEC_PERM_EXPR:
6627 0 : for (i = 0; i < 3; ++i)
6628 0 : if (!RECUR (TREE_OPERAND (t, i), true))
6629 : return false;
6630 : return true;
6631 :
6632 0 : case COND_EXPR:
6633 0 : if (COND_EXPR_IS_VEC_DELETE (t))
6634 : {
6635 0 : if (flags & tf_error)
6636 0 : error_at (loc, "%<delete[]%> is not a constant expression");
6637 : return false;
6638 : }
6639 : /* Fall through. */
6640 0 : case IF_STMT:
6641 0 : case VEC_COND_EXPR:
6642 : /* If the condition is a known constant, we know which of the legs we
6643 : care about; otherwise we only require that the condition and
6644 : either of the legs be potentially constant. */
6645 0 : tmp = TREE_OPERAND (t, 0);
6646 0 : if (!RECUR (tmp, rval))
6647 : return false;
6648 :
6649 0 : tmp = cxx_eval_outermost_constant_expr (tmp, true);
6650 : /* potential_constant_expression* isn't told if it is called for
6651 : manifestly_const_eval or not, so for consteval if always
6652 : process both branches as if the condition is not a known
6653 : constant. */
6654 0 : if (TREE_CODE (t) != IF_STMT || !IF_STMT_CONSTEVAL_P (t))
6655 : {
6656 0 : if (integer_zerop (tmp))
6657 0 : return RECUR (TREE_OPERAND (t, 2), want_rval);
6658 0 : else if (TREE_CODE (tmp) == INTEGER_CST)
6659 0 : return RECUR (TREE_OPERAND (t, 1), want_rval);
6660 : }
6661 0 : tmp = *jump_target;
6662 0 : for (i = 1; i < 3; ++i)
6663 : {
6664 0 : tree this_jump_target = tmp;
6665 0 : if (potential_constant_expression_1 (TREE_OPERAND (t, i), want_rval,
6666 : strict, now, tf_none,
6667 : &this_jump_target))
6668 : {
6669 0 : if (returns (&this_jump_target))
6670 0 : *jump_target = this_jump_target;
6671 0 : else if (!returns (jump_target))
6672 : {
6673 0 : if (breaks (&this_jump_target)
6674 0 : || continues (&this_jump_target))
6675 0 : *jump_target = this_jump_target;
6676 0 : if (i == 1)
6677 : {
6678 : /* If the then branch is potentially constant, but
6679 : does not return, check if the else branch
6680 : couldn't return, break or continue. */
6681 0 : hash_set<tree> pset;
6682 0 : check_for_return_continue_data data
6683 0 : = {&pset, NULL_TREE, NULL_TREE};
6684 0 : if (tree ret_expr
6685 0 : = rs_walk_tree (&TREE_OPERAND (t, 2),
6686 : check_for_return_continue, &data,
6687 : &pset))
6688 0 : *jump_target = ret_expr;
6689 0 : else if (*jump_target == NULL_TREE)
6690 : {
6691 0 : if (data.continue_stmt)
6692 0 : *jump_target = data.continue_stmt;
6693 0 : else if (data.break_stmt)
6694 0 : *jump_target = data.break_stmt;
6695 : }
6696 0 : }
6697 : }
6698 0 : return true;
6699 : }
6700 : }
6701 0 : if (flags & tf_error)
6702 0 : error_at (loc, "expression %qE is not a constant expression", t);
6703 : return false;
6704 :
6705 : case TYPE_DECL:
6706 : /* We can see these in statement-expressions. */
6707 : return true;
6708 :
6709 0 : case GOTO_EXPR:
6710 0 : {
6711 0 : tree *target = &TREE_OPERAND (t, 0);
6712 0 : if (breaks (target) || continues (target) || returns (target))
6713 : {
6714 0 : *jump_target = *target;
6715 0 : return true;
6716 : }
6717 0 : if (TREE_CODE (*target) == LABEL_DECL && DECL_ARTIFICIAL (*target))
6718 : return true;
6719 0 : if (flags & tf_error)
6720 0 : error_at (loc, "%<goto%> is not a constant expression");
6721 : return false;
6722 : }
6723 :
6724 0 : case LABEL_EXPR:
6725 0 : t = LABEL_EXPR_LABEL (t);
6726 0 : if (DECL_ARTIFICIAL (t))
6727 : return true;
6728 0 : else if (flags & tf_error)
6729 0 : error_at (loc, "label definition in %<constexpr%> function only "
6730 : "available with %<-std=c++2b%> or %<-std=gnu++2b%>");
6731 : return false;
6732 :
6733 0 : case ANNOTATE_EXPR:
6734 0 : return RECUR (TREE_OPERAND (t, 0), rval);
6735 :
6736 0 : case BIT_CAST_EXPR:
6737 0 : return RECUR (TREE_OPERAND (t, 0), rval);
6738 :
6739 0 : default:
6740 0 : sorry ("unexpected AST of kind %s", get_tree_code_name (TREE_CODE (t)));
6741 0 : rust_unreachable ();
6742 : return false;
6743 : }
6744 : #undef RECUR
6745 : }
6746 :
6747 : bool
6748 0 : potential_constant_expression_1 (tree t, bool want_rval, bool strict, bool now,
6749 : tsubst_flags_t flags)
6750 : {
6751 0 : if (flags & tf_error)
6752 : {
6753 : /* Check potentiality quietly first, as that could be performed more
6754 : efficiently in some cases (currently only for TRUTH_*_EXPR). If
6755 : that fails, replay the check noisily to give errors. */
6756 0 : flags &= ~tf_error;
6757 0 : if (potential_constant_expression_1 (t, want_rval, strict, now, flags))
6758 : return true;
6759 0 : flags |= tf_error;
6760 : }
6761 :
6762 0 : tree target = NULL_TREE;
6763 0 : return potential_constant_expression_1 (t, want_rval, strict, now, flags,
6764 0 : &target);
6765 : }
6766 :
6767 : // forked from gcc/cp/constexpr.cc fold_non_dependent_init
6768 :
6769 : /* Like maybe_constant_init but first fully instantiate the argument. */
6770 :
6771 : tree
6772 0 : fold_non_dependent_init (tree t, tsubst_flags_t /*=tf_warning_or_error*/,
6773 : bool manifestly_const_eval /*=false*/,
6774 : tree object /* = NULL_TREE */)
6775 : {
6776 0 : if (t == NULL_TREE)
6777 : return NULL_TREE;
6778 :
6779 0 : return maybe_constant_init (t, object, manifestly_const_eval);
6780 : }
6781 :
6782 : /* Check whether the shift operation with code CODE and type TYPE on LHS
6783 : and RHS is undefined. If it is, give an error with an explanation,
6784 : and return true; return false otherwise. */
6785 :
6786 : static bool
6787 346 : eval_check_shift_p (location_t loc, const constexpr_ctx *ctx,
6788 : enum tree_code code, tree type, tree lhs, tree rhs)
6789 : {
6790 346 : if ((code != LSHIFT_EXPR && code != RSHIFT_EXPR)
6791 2 : || TREE_CODE (lhs) != INTEGER_CST || TREE_CODE (rhs) != INTEGER_CST)
6792 : return false;
6793 :
6794 2 : tree lhstype = TREE_TYPE (lhs);
6795 2 : unsigned HOST_WIDE_INT uprec = TYPE_PRECISION (TREE_TYPE (lhs));
6796 :
6797 : /* [expr.shift] The behavior is undefined if the right operand
6798 : is negative, or greater than or equal to the length in bits
6799 : of the promoted left operand. */
6800 2 : if (tree_int_cst_sgn (rhs) == -1)
6801 : {
6802 0 : if (!ctx->quiet)
6803 0 : permerror (loc, "right operand of shift expression %q+E is negative",
6804 : build2_loc (loc, code, type, lhs, rhs));
6805 0 : return (!flag_permissive || ctx->quiet);
6806 : }
6807 2 : if (compare_tree_int (rhs, uprec) >= 0)
6808 : {
6809 0 : if (!ctx->quiet)
6810 0 : permerror (loc,
6811 : "right operand of shift expression %q+E is greater "
6812 : "than or equal to the precision %wu of the left operand",
6813 : build2_loc (loc, code, type, lhs, rhs), uprec);
6814 0 : return (!flag_permissive || ctx->quiet);
6815 : }
6816 :
6817 : /* The value of E1 << E2 is E1 left-shifted E2 bit positions; [...]
6818 : if E1 has a signed type and non-negative value, and E1x2^E2 is
6819 : representable in the corresponding unsigned type of the result type,
6820 : then that value, converted to the result type, is the resulting value;
6821 : otherwise, the behavior is undefined.
6822 : For C++20:
6823 : The value of E1 << E2 is the unique value congruent to E1 x 2^E2 modulo
6824 : 2^N, where N is the range exponent of the type of the result. */
6825 2 : if (code == LSHIFT_EXPR && !TYPE_OVERFLOW_WRAPS (lhstype))
6826 : {
6827 0 : if (tree_int_cst_sgn (lhs) == -1)
6828 : {
6829 0 : if (!ctx->quiet)
6830 0 : permerror (loc, "left operand of shift expression %q+E is negative",
6831 : build2_loc (loc, code, type, lhs, rhs));
6832 0 : return (!flag_permissive || ctx->quiet);
6833 : }
6834 : /* For signed x << y the following:
6835 : (unsigned) x >> ((prec (lhs) - 1) - y)
6836 : if > 1, is undefined. The right-hand side of this formula
6837 : is the highest bit of the LHS that can be set (starting from 0),
6838 : so that the shift doesn't overflow. We then right-shift the LHS
6839 : to see whether any other bit is set making the original shift
6840 : undefined -- the result is not representable in the corresponding
6841 : unsigned type. */
6842 0 : tree t = build_int_cst (unsigned_type_node, uprec - 1);
6843 0 : t = fold_build2 (MINUS_EXPR, unsigned_type_node, t, rhs);
6844 0 : tree ulhs = fold_convert (unsigned_type_for (lhstype), lhs);
6845 0 : t = fold_build2 (RSHIFT_EXPR, TREE_TYPE (ulhs), ulhs, t);
6846 0 : if (tree_int_cst_lt (integer_one_node, t))
6847 : {
6848 0 : if (!ctx->quiet)
6849 0 : permerror (loc, "shift expression %q+E overflows",
6850 : build2_loc (loc, code, type, lhs, rhs));
6851 0 : return (!flag_permissive || ctx->quiet);
6852 : }
6853 : }
6854 : return false;
6855 : }
6856 :
6857 : /* Rust rejects arithmetic overflow during constant evaluation for both signed
6858 : and unsigned types, unlike C where unsigned wraparound is well defined, so
6859 : TREE_OVERFLOW alone is not enough: GCC only sets it for signed operations.
6860 :
6861 : Operations built in a constant context are left unfolded by
6862 : Backend::arithmetic_or_logical_expression, so that we still see the
6863 : operation and its operands here rather than an INTEGER_CST which would
6864 : carry neither a location nor, for unsigned types, any trace of the
6865 : overflow.
6866 :
6867 : Returns true when the operation overflows, in which case the expression is
6868 : not a constant. */
6869 :
6870 : static bool
6871 346 : eval_check_overflow_p (location_t loc, const constexpr_ctx *ctx,
6872 : enum tree_code code, tree type, tree lhs, tree rhs)
6873 : {
6874 346 : if ((code != PLUS_EXPR && code != MINUS_EXPR && code != MULT_EXPR)
6875 313 : || TREE_CODE (lhs) != INTEGER_CST || TREE_CODE (rhs) != INTEGER_CST
6876 299 : || !INTEGRAL_TYPE_P (type)
6877 299 : || TYPE_PRECISION (TREE_TYPE (lhs)) != TYPE_PRECISION (type)
6878 645 : || TYPE_PRECISION (TREE_TYPE (rhs)) != TYPE_PRECISION (type))
6879 : return false;
6880 :
6881 : /* Note we deliberately do not check TYPE_OVERFLOW_WRAPS here: it is set for
6882 : unsigned types because wrapping is defined in C, but Rust rejects it. */
6883 299 : signop sgn = TYPE_SIGN (type);
6884 299 : wide_int lw = wi::to_wide (lhs);
6885 299 : wide_int rw = wi::to_wide (rhs);
6886 299 : wi::overflow_type ovf = wi::OVF_NONE;
6887 :
6888 299 : switch (code)
6889 : {
6890 188 : case PLUS_EXPR:
6891 188 : wi::add (lw, rw, sgn, &ovf);
6892 188 : break;
6893 2 : case MINUS_EXPR:
6894 2 : wi::sub (lw, rw, sgn, &ovf);
6895 2 : break;
6896 109 : case MULT_EXPR:
6897 109 : wi::mul (lw, rw, sgn, &ovf);
6898 109 : break;
6899 : default:
6900 : gcc_unreachable ();
6901 : }
6902 :
6903 299 : if (ovf == wi::OVF_NONE)
6904 : return false;
6905 :
6906 : /* Unlike the shift checks above this is a hard error, not a permerror:
6907 : overflow in a constant is always rejected by Rust. */
6908 11 : if (!ctx->quiet)
6909 : {
6910 11 : char *expr_str
6911 11 : = print_generic_expr_to_str (build2_loc (loc, code, type, lhs, rhs));
6912 11 : rust_error_at (loc, ErrorCode::E0080,
6913 : "attempt to compute %qs, which would overflow", expr_str);
6914 11 : free (expr_str);
6915 : }
6916 :
6917 : return true;
6918 299 : }
6919 :
6920 : /* Helper function for cxx_eval_binary_expression. Try to optimize
6921 : original POINTER_PLUS_EXPR T, LHS p+ RHS, return NULL_TREE if the
6922 : generic folding should be used. */
6923 :
6924 : static tree
6925 0 : fold_pointer_plus_expression (const constexpr_ctx *ctx, tree t, tree lhs,
6926 : tree rhs, bool *non_constant_p, bool *overflow_p,
6927 : tree *jump_target)
6928 : {
6929 0 : STRIP_NOPS (lhs);
6930 0 : if (TREE_CODE (lhs) != ADDR_EXPR)
6931 : return NULL_TREE;
6932 :
6933 0 : lhs = TREE_OPERAND (lhs, 0);
6934 :
6935 : /* &A[i] p+ j => &A[i + j] */
6936 0 : if (TREE_CODE (lhs) == ARRAY_REF
6937 0 : && TREE_CODE (TREE_OPERAND (lhs, 1)) == INTEGER_CST
6938 0 : && TREE_CODE (rhs) == INTEGER_CST && TYPE_SIZE_UNIT (TREE_TYPE (lhs))
6939 0 : && TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (lhs))) == INTEGER_CST)
6940 : {
6941 0 : tree orig_type = TREE_TYPE (t);
6942 0 : location_t loc = EXPR_LOCATION (t);
6943 0 : tree type = TREE_TYPE (lhs);
6944 :
6945 0 : t = fold_convert_loc (loc, ssizetype, TREE_OPERAND (lhs, 1));
6946 0 : tree nelts = array_type_nelts_top (TREE_TYPE (TREE_OPERAND (lhs, 0)));
6947 0 : nelts = eval_constant_expression (ctx, nelts, true, non_constant_p,
6948 : overflow_p, jump_target);
6949 0 : if (*non_constant_p)
6950 : return NULL_TREE;
6951 0 : if (*jump_target)
6952 : return NULL_TREE;
6953 : /* Don't fold an out-of-bound access. */
6954 0 : if (!tree_int_cst_le (t, nelts))
6955 : return NULL_TREE;
6956 0 : rhs = fold_convert (ssizetype, rhs);
6957 : /* Don't fold if rhs can't be divided exactly by TYPE_SIZE_UNIT.
6958 : constexpr int A[1]; ... (char *)&A[0] + 1 */
6959 0 : if (!integer_zerop (fold_build2_loc (loc, TRUNC_MOD_EXPR, sizetype, rhs,
6960 0 : TYPE_SIZE_UNIT (type))))
6961 : return NULL_TREE;
6962 : /* Make sure to treat the second operand of POINTER_PLUS_EXPR
6963 : as signed. */
6964 0 : rhs = fold_build2_loc (loc, EXACT_DIV_EXPR, ssizetype, rhs,
6965 0 : TYPE_SIZE_UNIT (type));
6966 0 : t = size_binop_loc (loc, PLUS_EXPR, rhs, t);
6967 0 : t = build4_loc (loc, ARRAY_REF, type, TREE_OPERAND (lhs, 0), t, NULL_TREE,
6968 : NULL_TREE);
6969 0 : t = build_fold_addr_expr (t);
6970 0 : t = fold_convert (orig_type, t);
6971 0 : return eval_constant_expression (ctx, t, true, non_constant_p, overflow_p,
6972 0 : jump_target);
6973 : }
6974 :
6975 : return NULL_TREE;
6976 : }
6977 :
6978 : /* Try to fold expressions like
6979 : (struct S *) (&a[0].D.2378 + 12)
6980 : into
6981 : &MEM <struct T> [(void *)&a + 12B]
6982 : This is something normally done by gimple_fold_stmt_to_constant_1
6983 : on GIMPLE, but is undesirable on GENERIC if we are e.g. going to
6984 : dereference the address because some details are lost.
6985 : For pointer comparisons we want such folding though so that
6986 : match.pd address_compare optimization works. */
6987 :
6988 : static tree
6989 2 : maybe_fold_addr_pointer_plus (tree t)
6990 : {
6991 2 : while (CONVERT_EXPR_P (t) && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (t, 0))))
6992 0 : t = TREE_OPERAND (t, 0);
6993 2 : if (TREE_CODE (t) != POINTER_PLUS_EXPR)
6994 : return NULL_TREE;
6995 0 : tree op0 = TREE_OPERAND (t, 0);
6996 0 : tree op1 = TREE_OPERAND (t, 1);
6997 0 : if (TREE_CODE (op1) != INTEGER_CST)
6998 : return NULL_TREE;
6999 0 : while (CONVERT_EXPR_P (op0)
7000 0 : && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (op0, 0))))
7001 0 : op0 = TREE_OPERAND (op0, 0);
7002 0 : if (TREE_CODE (op0) != ADDR_EXPR)
7003 : return NULL_TREE;
7004 0 : op1 = fold_convert (ptr_type_node, op1);
7005 0 : tree r = fold_build2 (MEM_REF, TREE_TYPE (TREE_TYPE (op0)), op0, op1);
7006 0 : return build1_loc (EXPR_LOCATION (t), ADDR_EXPR, TREE_TYPE (op0), r);
7007 : }
7008 :
7009 : static tree
7010 2 : maybe_fold_reference_address_to_pointer (tree t)
7011 : {
7012 2 : if (!CONVERT_EXPR_P (t) || !POINTER_TYPE_P (TREE_TYPE (t)))
7013 : return t;
7014 :
7015 2 : tree op = TREE_OPERAND (t, 0);
7016 2 : if (TREE_CODE (op) != ADDR_EXPR || !TYPE_REF_P (TREE_TYPE (op)))
7017 : return t;
7018 :
7019 2 : return build_fold_addr_expr_with_type_loc (EXPR_LOCATION (t),
7020 2 : TREE_OPERAND (op, 0),
7021 4 : TREE_TYPE (t));
7022 : }
7023 :
7024 : } // namespace Compile
7025 : } // namespace Rust
7026 :
7027 : using namespace Rust::Compile;
7028 :
7029 : #include "gt-rust-rust-constexpr.h"
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