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 "gimplify.h"
26 : #include "tree-iterator.h"
27 : #include "timevar.h"
28 : #include "varasm.h"
29 : #include "cgraph.h"
30 : #include "tree-inline.h"
31 : #include "vec.h"
32 : #include "function.h"
33 : #include "diagnostic.h"
34 : #include "target.h"
35 : #include "builtins.h"
36 :
37 : #define VERIFY_CONSTANT(X) \
38 : do \
39 : { \
40 : if (verify_constant ((X), ctx->quiet, non_constant_p, overflow_p)) \
41 : return t; \
42 : } \
43 : while (0)
44 :
45 : namespace Rust {
46 : namespace Compile {
47 :
48 : /* Returns true iff FUN is an instantiation of a constexpr function
49 : template or a defaulted constexpr function. */
50 :
51 : bool
52 0 : is_instantiation_of_constexpr (tree fun)
53 : {
54 0 : return DECL_DECLARED_CONSTEXPR_P (fun);
55 : }
56 :
57 : /* Return true if T is a literal type. */
58 :
59 : bool
60 0 : literal_type_p (tree t)
61 : {
62 0 : if (SCALAR_TYPE_P (t) || VECTOR_TYPE_P (t) || TYPE_REF_P (t)
63 : || (VOID_TYPE_P (t)))
64 0 : return true;
65 :
66 : if (TREE_CODE (t) == ARRAY_TYPE)
67 0 : return literal_type_p (strip_array_types (t));
68 : return false;
69 : }
70 :
71 : static bool verify_constant (tree, bool, bool *, bool *);
72 :
73 : static HOST_WIDE_INT find_array_ctor_elt (tree ary, tree dindex,
74 : bool insert = false);
75 : static int array_index_cmp (tree key, tree index);
76 : static bool potential_constant_expression_1 (tree t, bool want_rval,
77 : bool strict, bool now,
78 : tsubst_flags_t flags,
79 : tree *jump_target);
80 : bool potential_constant_expression_1 (tree t, bool want_rval, bool strict,
81 : bool now, tsubst_flags_t flags);
82 : tree unshare_constructor (tree t MEM_STAT_DECL);
83 : void maybe_save_constexpr_fundef (tree fun);
84 :
85 : static bool returns (tree *jump_target);
86 : static bool breaks (tree *jump_target);
87 : static bool continues (tree *jump_target);
88 : static bool switches (tree *jump_target);
89 :
90 4950 : struct constexpr_global_ctx
91 : {
92 : /* Values for any temporaries or local variables within the
93 : constant-expression. */
94 : hash_map<tree, tree> values;
95 : /* Number of cxx_eval_constant_expression calls (except skipped ones,
96 : on simple constants or location wrappers) encountered during current
97 : cxx_eval_outermost_constant_expr call. */
98 : HOST_WIDE_INT constexpr_ops_count;
99 : /* Heap VAR_DECLs created during the evaluation of the outermost constant
100 : expression. */
101 : auto_vec<tree, 16> heap_vars;
102 : /* Cleanups that need to be evaluated at the end of CLEANUP_POINT_EXPR. */
103 : vec<tree> *cleanups;
104 : /* If non-null, only allow modification of existing values of the variables
105 : in this set. Set by modifiable_tracker, below. */
106 : hash_set<tree> *modifiable;
107 : /* Number of heap VAR_DECL deallocations. */
108 : unsigned heap_dealloc_count;
109 : /* Constructor. */
110 4950 : constexpr_global_ctx ()
111 4950 : : constexpr_ops_count (0), cleanups (NULL), heap_dealloc_count (0)
112 4950 : {}
113 :
114 35 : tree get_value (tree t)
115 : {
116 35 : if (tree *p = values.get (t))
117 34 : if (*p != void_node)
118 34 : return *p;
119 : return NULL_TREE;
120 : }
121 : tree *get_value_ptr (tree t, bool initializing)
122 : {
123 : if (modifiable && !modifiable->contains (t))
124 : return nullptr;
125 : if (tree *p = values.get (t))
126 : {
127 : if (*p != void_node)
128 : return p;
129 : else if (initializing)
130 : {
131 : *p = NULL_TREE;
132 : return p;
133 : }
134 : }
135 : return nullptr;
136 : }
137 : void put_value (tree t, tree v)
138 : {
139 : bool already_in_map = values.put (t, v);
140 : if (!already_in_map && modifiable)
141 : modifiable->add (t);
142 : }
143 : void destroy_value (tree t)
144 : {
145 : if (TREE_CODE (t) == VAR_DECL || TREE_CODE (t) == PARM_DECL
146 : || TREE_CODE (t) == RESULT_DECL)
147 : values.put (t, void_node);
148 : else
149 : values.remove (t);
150 : }
151 : void clear_value (tree t) { values.remove (t); }
152 : };
153 :
154 : /* In constexpr.cc */
155 : /* Representation of entries in the constexpr function definition table. */
156 :
157 : struct GTY ((for_user)) rust_constexpr_fundef
158 : {
159 : tree decl;
160 : tree body;
161 : tree parms;
162 : tree result;
163 : };
164 :
165 : /* Objects of this type represent calls to constexpr functions
166 : along with the bindings of parameters to their arguments, for
167 : the purpose of compile time evaluation. */
168 :
169 : struct GTY ((for_user)) rust_constexpr_call
170 : {
171 : /* Description of the constexpr function definition. */
172 : rust_constexpr_fundef *fundef;
173 : /* Parameter bindings environment. A TREE_VEC of arguments. */
174 : tree bindings;
175 : /* Result of the call.
176 : NULL means the call is being evaluated.
177 : error_mark_node means that the evaluation was erroneous;
178 : otherwise, the actual value of the call. */
179 : tree result;
180 : /* The hash of this call; we remember it here to avoid having to
181 : recalculate it when expanding the hash table. */
182 : hashval_t hash;
183 : /* Whether __builtin_is_constant_evaluated() should evaluate to true. */
184 : bool manifestly_const_eval;
185 : };
186 :
187 : struct rust_constexpr_call_hasher : ggc_ptr_hash<rust_constexpr_call>
188 : {
189 : static hashval_t hash (rust_constexpr_call *);
190 : static bool equal (rust_constexpr_call *, rust_constexpr_call *);
191 : };
192 :
193 : enum constexpr_switch_state
194 : {
195 : /* Used when processing a switch for the first time by cxx_eval_switch_expr
196 : and default: label for that switch has not been seen yet. */
197 : css_default_not_seen,
198 : /* Used when processing a switch for the first time by cxx_eval_switch_expr
199 : and default: label for that switch has been seen already. */
200 : css_default_seen,
201 : /* Used when processing a switch for the second time by
202 : cxx_eval_switch_expr, where default: label should match. */
203 : css_default_processing
204 : };
205 :
206 : struct constexpr_ctx
207 : {
208 : /* The part of the context that needs to be unique to the whole
209 : cxx_eval_outermost_constant_expr invocation. */
210 : constexpr_global_ctx *global;
211 : /* The innermost call we're evaluating. */
212 : rust_constexpr_call *call;
213 : /* SAVE_EXPRs and TARGET_EXPR_SLOT vars of TARGET_EXPRs that we've seen
214 : within the current LOOP_EXPR. NULL if we aren't inside a loop. */
215 : vec<tree> *save_exprs;
216 : /* The CONSTRUCTOR we're currently building up for an aggregate
217 : initializer. */
218 : tree ctor;
219 : /* The object we're building the CONSTRUCTOR for. */
220 : tree object;
221 : /* If inside SWITCH_EXPR. */
222 : constexpr_switch_state *css_state;
223 : /* The aggregate initialization context inside which this one is nested. This
224 : is used by lookup_placeholder to resolve PLACEHOLDER_EXPRs. */
225 : const constexpr_ctx *parent;
226 :
227 : /* Whether we should error on a non-constant expression or fail quietly.
228 : This flag needs to be here, but some of the others could move to global
229 : if they get larger than a word. */
230 : bool quiet;
231 : /* Whether we are strictly conforming to constant expression rules or
232 : trying harder to get a constant value. */
233 : bool strict;
234 : /* Whether __builtin_is_constant_evaluated () should be true. */
235 : bool manifestly_const_eval;
236 : };
237 :
238 : struct rust_constexpr_fundef_hasher : ggc_ptr_hash<rust_constexpr_fundef>
239 : {
240 : static hashval_t hash (const rust_constexpr_fundef *);
241 : static bool equal (const rust_constexpr_fundef *,
242 : const rust_constexpr_fundef *);
243 : };
244 :
245 : /* This table holds all constexpr function definitions seen in
246 : the current translation unit. */
247 :
248 : static GTY (())
249 : hash_table<rust_constexpr_fundef_hasher> *constexpr_fundef_table;
250 :
251 : /* Utility function used for managing the constexpr function table.
252 : Return true if the entries pointed to by P and Q are for the
253 : same constexpr function. */
254 :
255 : inline bool
256 10462 : rust_constexpr_fundef_hasher::equal (const rust_constexpr_fundef *lhs,
257 : const rust_constexpr_fundef *rhs)
258 : {
259 10462 : return lhs->decl == rhs->decl;
260 : }
261 :
262 : /* Utility function used for managing the constexpr function table.
263 : Return a hash value for the entry pointed to by Q. */
264 :
265 : inline hashval_t
266 16101 : rust_constexpr_fundef_hasher::hash (const rust_constexpr_fundef *fundef)
267 : {
268 16101 : return DECL_UID (fundef->decl);
269 : }
270 :
271 : /* Return a previously saved definition of function FUN. */
272 :
273 : rust_constexpr_fundef *
274 2103 : retrieve_constexpr_fundef (tree fun)
275 : {
276 2103 : if (constexpr_fundef_table == NULL)
277 : return NULL;
278 :
279 2103 : rust_constexpr_fundef fundef = {fun, NULL_TREE, NULL_TREE, NULL_TREE};
280 2103 : return constexpr_fundef_table->find (&fundef);
281 : }
282 :
283 : /* This internal flag controls whether we should avoid doing anything during
284 : constexpr evaluation that would cause extra DECL_UID generation, such as
285 : template instantiation and function body copying. */
286 :
287 : static bool uid_sensitive_constexpr_evaluation_value;
288 :
289 : /* An internal counter that keeps track of the number of times
290 : uid_sensitive_constexpr_evaluation_p returned true. */
291 :
292 : static unsigned uid_sensitive_constexpr_evaluation_true_counter;
293 :
294 : /* The accessor for uid_sensitive_constexpr_evaluation_value which also
295 : increments the corresponding counter. */
296 :
297 : static bool
298 0 : uid_sensitive_constexpr_evaluation_p ()
299 : {
300 0 : if (uid_sensitive_constexpr_evaluation_value)
301 : {
302 0 : ++uid_sensitive_constexpr_evaluation_true_counter;
303 0 : return true;
304 : }
305 : else
306 : return false;
307 : }
308 :
309 : /* RAII sentinel that saves the value of a variable, optionally
310 : overrides it right away, and restores its value when the sentinel
311 : id destructed. */
312 :
313 : template <typename T> class temp_override
314 : {
315 : T &overridden_variable;
316 : T saved_value;
317 :
318 : public:
319 0 : temp_override (T &var) : overridden_variable (var), saved_value (var) {}
320 0 : temp_override (T &var, T overrider)
321 0 : : overridden_variable (var), saved_value (var)
322 : {
323 0 : overridden_variable = overrider;
324 : }
325 0 : ~temp_override () { overridden_variable = saved_value; }
326 : };
327 :
328 : /* An RAII sentinel used to restrict constexpr evaluation so that it
329 : doesn't do anything that causes extra DECL_UID generation. */
330 :
331 : struct uid_sensitive_constexpr_evaluation_sentinel
332 : {
333 : temp_override<bool> ovr;
334 : uid_sensitive_constexpr_evaluation_sentinel ();
335 : };
336 :
337 : /* Used to determine whether uid_sensitive_constexpr_evaluation_p was
338 : called and returned true, indicating that we've restricted constexpr
339 : evaluation in order to avoid UID generation. We use this to control
340 : updates to the fold_cache and cv_cache. */
341 :
342 : struct uid_sensitive_constexpr_evaluation_checker
343 : {
344 : const unsigned saved_counter;
345 : uid_sensitive_constexpr_evaluation_checker ();
346 : bool evaluation_restricted_p () const;
347 : };
348 :
349 : /* The default constructor for uid_sensitive_constexpr_evaluation_sentinel
350 : enables the internal flag for uid_sensitive_constexpr_evaluation_p
351 : during the lifetime of the sentinel object. Upon its destruction, the
352 : previous value of uid_sensitive_constexpr_evaluation_p is restored. */
353 :
354 0 : uid_sensitive_constexpr_evaluation_sentinel ::
355 0 : uid_sensitive_constexpr_evaluation_sentinel ()
356 0 : : ovr (uid_sensitive_constexpr_evaluation_value, true)
357 0 : {}
358 :
359 : /* The default constructor for uid_sensitive_constexpr_evaluation_checker
360 : records the current number of times that uid_sensitive_constexpr_evaluation_p
361 : has been called and returned true. */
362 :
363 0 : uid_sensitive_constexpr_evaluation_checker ::
364 0 : uid_sensitive_constexpr_evaluation_checker ()
365 0 : : saved_counter (uid_sensitive_constexpr_evaluation_true_counter)
366 0 : {}
367 :
368 : /* Returns true iff uid_sensitive_constexpr_evaluation_p is true, and
369 : some constexpr evaluation was restricted due to u_s_c_e_p being called
370 : and returning true during the lifetime of this checker object. */
371 :
372 : bool
373 0 : uid_sensitive_constexpr_evaluation_checker::evaluation_restricted_p () const
374 : {
375 0 : return (uid_sensitive_constexpr_evaluation_value
376 0 : && saved_counter != uid_sensitive_constexpr_evaluation_true_counter);
377 : }
378 :
379 : /* A table of all constexpr calls that have been evaluated by the
380 : compiler in this translation unit. */
381 :
382 : static GTY (()) hash_table<rust_constexpr_call_hasher> *constexpr_call_table;
383 :
384 : /* Compute a hash value for a constexpr call representation. */
385 :
386 : inline hashval_t
387 2824 : rust_constexpr_call_hasher::hash (rust_constexpr_call *info)
388 : {
389 2824 : return info->hash;
390 : }
391 :
392 : /* Return true if the objects pointed to by P and Q represent calls
393 : to the same constexpr function with the same arguments.
394 : Otherwise, return false. */
395 :
396 : bool
397 818 : rust_constexpr_call_hasher::equal (rust_constexpr_call *lhs,
398 : rust_constexpr_call *rhs)
399 : {
400 818 : if (lhs == rhs)
401 : return true;
402 818 : if (lhs->hash != rhs->hash)
403 : return false;
404 0 : if (lhs->manifestly_const_eval != rhs->manifestly_const_eval)
405 : return false;
406 0 : if (!rust_constexpr_fundef_hasher::equal (lhs->fundef, rhs->fundef))
407 : return false;
408 0 : return rs_tree_equal (lhs->bindings, rhs->bindings);
409 : }
410 :
411 : /* Initialize the constexpr call table, if needed. */
412 :
413 : static void
414 2103 : maybe_initialize_constexpr_call_table (void)
415 : {
416 2103 : if (constexpr_call_table == NULL)
417 585 : constexpr_call_table
418 585 : = hash_table<rust_constexpr_call_hasher>::create_ggc (101);
419 2103 : }
420 :
421 : /* During constexpr CALL_EXPR evaluation, to avoid issues with sharing when
422 : a function happens to get called recursively, we unshare the callee
423 : function's body and evaluate this unshared copy instead of evaluating the
424 : original body.
425 :
426 : FUNDEF_COPIES_TABLE is a per-function freelist of these unshared function
427 : copies. The underlying data structure of FUNDEF_COPIES_TABLE is a hash_map
428 : that's keyed off of the original FUNCTION_DECL and whose value is a
429 : TREE_LIST of this function's unused copies awaiting reuse.
430 :
431 : This is not GC-deletable to avoid GC affecting UID generation. */
432 :
433 : static GTY (()) decl_tree_map *fundef_copies_table;
434 :
435 : /* Reuse a copy or create a new unshared copy of the function FUN.
436 : Return this copy. We use a TREE_LIST whose PURPOSE is body, VALUE
437 : is parms, TYPE is result. */
438 :
439 : static tree
440 2103 : get_fundef_copy (rust_constexpr_fundef *fundef)
441 : {
442 2103 : tree copy;
443 2103 : bool existed;
444 2103 : tree *slot
445 2103 : = &(hash_map_safe_get_or_insert<hm_ggc> (fundef_copies_table, fundef->decl,
446 : &existed, 127));
447 :
448 2103 : if (!existed)
449 : {
450 : /* There is no cached function available, or in use. We can use
451 : the function directly. That the slot is now created records
452 : that this function is now in use. */
453 2102 : copy = build_tree_list (fundef->body, fundef->parms);
454 2102 : TREE_TYPE (copy) = fundef->result;
455 : }
456 1 : else if (*slot == NULL_TREE)
457 : {
458 0 : if (uid_sensitive_constexpr_evaluation_p ())
459 0 : return NULL_TREE;
460 :
461 : /* We've already used the function itself, so make a copy. */
462 0 : copy = build_tree_list (NULL, NULL);
463 0 : tree saved_body = DECL_SAVED_TREE (fundef->decl);
464 0 : tree saved_parms = DECL_ARGUMENTS (fundef->decl);
465 0 : tree saved_result = DECL_RESULT (fundef->decl);
466 0 : tree saved_fn = current_function_decl;
467 0 : DECL_SAVED_TREE (fundef->decl) = fundef->body;
468 0 : DECL_ARGUMENTS (fundef->decl) = fundef->parms;
469 0 : DECL_RESULT (fundef->decl) = fundef->result;
470 0 : current_function_decl = fundef->decl;
471 0 : TREE_PURPOSE (copy)
472 0 : = copy_fn (fundef->decl, TREE_VALUE (copy), TREE_TYPE (copy));
473 0 : current_function_decl = saved_fn;
474 0 : DECL_RESULT (fundef->decl) = saved_result;
475 0 : DECL_ARGUMENTS (fundef->decl) = saved_parms;
476 0 : DECL_SAVED_TREE (fundef->decl) = saved_body;
477 : }
478 : else
479 : {
480 : /* We have a cached function available. */
481 1 : copy = *slot;
482 1 : *slot = TREE_CHAIN (copy);
483 : }
484 :
485 : return copy;
486 : }
487 :
488 : /* Save the copy COPY of function FUN for later reuse by
489 : get_fundef_copy(). By construction, there will always be an entry
490 : to find. */
491 :
492 : static void
493 2103 : save_fundef_copy (tree fun, tree copy)
494 : {
495 2103 : tree *slot = fundef_copies_table->get (fun);
496 2103 : TREE_CHAIN (copy) = *slot;
497 2103 : *slot = copy;
498 2103 : }
499 :
500 : static tree constant_value_1 (tree decl, bool strict_p,
501 : bool return_aggregate_cst_ok_p, bool unshare_p);
502 : static tree decl_really_constant_value (tree decl, bool unshare_p /*= true*/);
503 : tree decl_constant_value (tree decl, bool unshare_p);
504 :
505 : static void non_const_var_error (location_t loc, tree r);
506 :
507 : static tree eval_constant_expression (const constexpr_ctx *ctx, tree, bool,
508 : bool *, bool *, tree *jump_target);
509 :
510 : static tree constexpr_fn_retval (const constexpr_ctx *ctx, tree r);
511 :
512 : static tree eval_store_expression (const constexpr_ctx *ctx, tree r, bool,
513 : bool *, bool *, tree *jump_target);
514 :
515 : static tree eval_call_expression (const constexpr_ctx *ctx, tree r, bool,
516 : bool *, bool *, tree *);
517 :
518 : static tree eval_binary_expression (const constexpr_ctx *ctx, tree r, bool,
519 : bool *, bool *, tree *jump_target);
520 :
521 : static tree get_function_named_in_call (tree t);
522 :
523 : static tree eval_statement_list (const constexpr_ctx *ctx, tree t,
524 : bool *non_constant_p, bool *overflow_p,
525 : tree *jump_target);
526 : static tree extract_string_elt (tree string, unsigned chars_per_elt,
527 : unsigned index);
528 :
529 : static tree eval_conditional_expression (const constexpr_ctx *ctx, tree t,
530 : bool lval, bool *non_constant_p,
531 : bool *overflow_p, tree *jump_target);
532 :
533 : static tree eval_bit_field_ref (const constexpr_ctx *ctx, tree t, bool lval,
534 : bool *non_constant_p, bool *overflow_p,
535 : tree *jump_target);
536 :
537 : static tree eval_loop_expr (const constexpr_ctx *ctx, tree t,
538 : bool *non_constant_p, bool *overflow_p,
539 : tree *jump_target);
540 :
541 : static tree eval_switch_expr (const constexpr_ctx *ctx, tree t,
542 : bool *non_constant_p, bool *overflow_p,
543 : tree *jump_target);
544 :
545 : static tree eval_unary_expression (const constexpr_ctx *ctx, tree t,
546 : bool /*lval*/, bool *non_constant_p,
547 : bool *overflow_p, tree *jump_target);
548 : static bool eval_check_shift_p (location_t loc, const constexpr_ctx *ctx,
549 : enum tree_code code, tree type, tree lhs,
550 : tree rhs);
551 : static tree fold_pointer_plus_expression (const constexpr_ctx *ctx, tree t,
552 : tree lhs, tree rhs,
553 : bool *non_constant_p,
554 : bool *overflow_p, tree *jump_target);
555 : static tree maybe_fold_addr_pointer_plus (tree t);
556 :
557 : /* Variables and functions to manage constexpr call expansion context.
558 : These do not need to be marked for PCH or GC. */
559 :
560 : /* FIXME remember and print actual constant arguments. */
561 : static vec<tree> call_stack;
562 : static int call_stack_tick;
563 : static int last_cx_error_tick;
564 :
565 : static int
566 2103 : push_cx_call_context (tree call)
567 : {
568 2103 : ++call_stack_tick;
569 2103 : if (!EXPR_HAS_LOCATION (call))
570 303 : SET_EXPR_LOCATION (call, input_location);
571 2103 : call_stack.safe_push (call);
572 2103 : int len = call_stack.length ();
573 2103 : if (len > max_constexpr_depth)
574 0 : return false;
575 : return len;
576 : }
577 :
578 : static void
579 2103 : pop_cx_call_context (void)
580 : {
581 2103 : ++call_stack_tick;
582 2103 : call_stack.pop ();
583 2103 : }
584 :
585 : vec<tree>
586 0 : cx_error_context (void)
587 : {
588 0 : vec<tree> r = vNULL;
589 0 : if (call_stack_tick != last_cx_error_tick && !call_stack.is_empty ())
590 : r = call_stack;
591 0 : last_cx_error_tick = call_stack_tick;
592 0 : return r;
593 : }
594 :
595 : // this is ported from cxx_eval_outermost_constant_expr
596 : tree
597 4950 : fold_expr (tree expr)
598 : {
599 4950 : bool allow_non_constant = false;
600 4950 : bool strict = true;
601 4950 : bool manifestly_const_eval = false;
602 :
603 4950 : constexpr_global_ctx global_ctx;
604 4950 : constexpr_ctx ctx
605 : = {&global_ctx, NULL,
606 : NULL, NULL,
607 : NULL, NULL,
608 : NULL, allow_non_constant,
609 4950 : strict, manifestly_const_eval || !allow_non_constant};
610 :
611 4950 : auto_vec<tree, 16> cleanups;
612 4950 : global_ctx.cleanups = &cleanups;
613 :
614 4950 : bool non_constant_p = false;
615 4950 : bool overflow_p = false;
616 :
617 4950 : tree jump_target = NULL_TREE;
618 4950 : tree folded = eval_constant_expression (&ctx, expr, false, &non_constant_p,
619 : &overflow_p, &jump_target);
620 4950 : rust_assert (folded != NULL_TREE);
621 :
622 : // more logic here to possibly port
623 4950 : return folded;
624 4950 : }
625 :
626 : static bool
627 7 : same_type_ignoring_tlq_and_bounds_p (tree type1, tree type2)
628 : {
629 7 : while (TREE_CODE (type1) == ARRAY_TYPE && TREE_CODE (type2) == ARRAY_TYPE
630 7 : && (!TYPE_DOMAIN (type1) || !TYPE_DOMAIN (type2)))
631 : {
632 0 : type1 = TREE_TYPE (type1);
633 0 : type2 = TREE_TYPE (type2);
634 : }
635 7 : return same_type_ignoring_top_level_qualifiers_p (type1, type2);
636 : }
637 :
638 : // forked from gcc/cp/constexpr.cc cxx_union_active_member
639 :
640 : /* Try to determine the currently active union member for an expression
641 : with UNION_TYPE. If it can be determined, return the FIELD_DECL,
642 : otherwise return NULL_TREE. */
643 :
644 : static tree
645 0 : union_active_member (const constexpr_ctx *ctx, tree t, tree *jump_target)
646 : {
647 0 : constexpr_ctx new_ctx = *ctx;
648 0 : new_ctx.quiet = true;
649 0 : bool non_constant_p = false, overflow_p = false;
650 0 : tree ctor = eval_constant_expression (&new_ctx, t, false, &non_constant_p,
651 : &overflow_p, jump_target);
652 0 : if (TREE_CODE (ctor) == CONSTRUCTOR && CONSTRUCTOR_NELTS (ctor) == 1
653 0 : && CONSTRUCTOR_ELT (ctor, 0)->index
654 0 : && TREE_CODE (CONSTRUCTOR_ELT (ctor, 0)->index) == FIELD_DECL)
655 : return CONSTRUCTOR_ELT (ctor, 0)->index;
656 : return NULL_TREE;
657 : }
658 :
659 : // forked from gcc/cp/constexpr.cc cxx_fold_indirect_ref_1
660 :
661 : static tree
662 0 : fold_indirect_ref_1 (const constexpr_ctx *ctx, location_t loc, tree type,
663 : tree op, unsigned HOST_WIDE_INT off, bool *empty_base,
664 : tree *jump_target)
665 : {
666 0 : tree optype = TREE_TYPE (op);
667 0 : unsigned HOST_WIDE_INT const_nunits;
668 0 : if (off == 0 && similar_type_p (optype, type))
669 : return op;
670 0 : else if (TREE_CODE (optype) == COMPLEX_TYPE
671 0 : && similar_type_p (type, TREE_TYPE (optype)))
672 : {
673 : /* *(foo *)&complexfoo => __real__ complexfoo */
674 0 : if (off == 0)
675 0 : return build1_loc (loc, REALPART_EXPR, type, op);
676 : /* ((foo*)&complexfoo)[1] => __imag__ complexfoo */
677 0 : else if (tree_to_uhwi (TYPE_SIZE_UNIT (type)) == off)
678 0 : return build1_loc (loc, IMAGPART_EXPR, type, op);
679 : }
680 : /* ((foo*)&vectorfoo)[x] => BIT_FIELD_REF<vectorfoo,...> */
681 0 : else if (VECTOR_TYPE_P (optype) && similar_type_p (type, TREE_TYPE (optype))
682 0 : && TYPE_VECTOR_SUBPARTS (optype).is_constant (&const_nunits))
683 : {
684 0 : unsigned HOST_WIDE_INT part_width = tree_to_uhwi (TYPE_SIZE_UNIT (type));
685 0 : unsigned HOST_WIDE_INT max_offset = part_width * const_nunits;
686 0 : if (off < max_offset && off % part_width == 0)
687 : {
688 0 : tree index = bitsize_int (off * BITS_PER_UNIT);
689 0 : return build3_loc (loc, BIT_FIELD_REF, type, op, TYPE_SIZE (type),
690 0 : index);
691 : }
692 : }
693 : /* ((foo *)&fooarray)[x] => fooarray[x] */
694 0 : else if (TREE_CODE (optype) == ARRAY_TYPE
695 0 : && tree_fits_uhwi_p (TYPE_SIZE_UNIT (TREE_TYPE (optype)))
696 0 : && !integer_zerop (TYPE_SIZE_UNIT (TREE_TYPE (optype))))
697 : {
698 0 : tree type_domain = TYPE_DOMAIN (optype);
699 0 : tree min_val = size_zero_node;
700 0 : if (type_domain && TYPE_MIN_VALUE (type_domain))
701 0 : min_val = TYPE_MIN_VALUE (type_domain);
702 0 : unsigned HOST_WIDE_INT el_sz
703 0 : = tree_to_uhwi (TYPE_SIZE_UNIT (TREE_TYPE (optype)));
704 0 : unsigned HOST_WIDE_INT idx = off / el_sz;
705 0 : unsigned HOST_WIDE_INT rem = off % el_sz;
706 0 : if (tree_fits_uhwi_p (min_val))
707 : {
708 0 : tree index = size_int (idx + tree_to_uhwi (min_val));
709 0 : op = build4_loc (loc, ARRAY_REF, TREE_TYPE (optype), op, index,
710 : NULL_TREE, NULL_TREE);
711 0 : return fold_indirect_ref_1 (ctx, loc, type, op, rem, empty_base,
712 0 : jump_target);
713 : }
714 : }
715 : /* ((foo *)&struct_with_foo_field)[x] => COMPONENT_REF */
716 0 : else if (TREE_CODE (optype) == RECORD_TYPE
717 0 : || TREE_CODE (optype) == UNION_TYPE)
718 : {
719 0 : if (TREE_CODE (optype) == UNION_TYPE)
720 : /* For unions prefer the currently active member. */
721 0 : if (tree field = union_active_member (ctx, op, jump_target))
722 : {
723 0 : unsigned HOST_WIDE_INT el_sz
724 0 : = tree_to_uhwi (TYPE_SIZE_UNIT (TREE_TYPE (field)));
725 0 : if (off < el_sz)
726 : {
727 0 : tree cop = build3 (COMPONENT_REF, TREE_TYPE (field), op, field,
728 : NULL_TREE);
729 0 : if (tree ret = fold_indirect_ref_1 (ctx, loc, type, cop, off,
730 : empty_base, jump_target))
731 : return ret;
732 : }
733 : }
734 0 : for (tree field = TYPE_FIELDS (optype); field; field = DECL_CHAIN (field))
735 0 : if (TREE_CODE (field) == FIELD_DECL
736 0 : && TREE_TYPE (field) != error_mark_node
737 0 : && tree_fits_uhwi_p (TYPE_SIZE_UNIT (TREE_TYPE (field))))
738 : {
739 0 : tree pos = byte_position (field);
740 0 : if (!tree_fits_uhwi_p (pos))
741 0 : continue;
742 0 : unsigned HOST_WIDE_INT upos = tree_to_uhwi (pos);
743 0 : unsigned HOST_WIDE_INT el_sz
744 0 : = tree_to_uhwi (TYPE_SIZE_UNIT (TREE_TYPE (field)));
745 0 : if (upos <= off && off < upos + el_sz)
746 : {
747 0 : tree cop = build3 (COMPONENT_REF, TREE_TYPE (field), op, field,
748 : NULL_TREE);
749 0 : if (tree ret
750 0 : = fold_indirect_ref_1 (ctx, loc, type, cop, off - upos,
751 : empty_base, jump_target))
752 : return ret;
753 : }
754 : }
755 : /* Also handle conversion to an empty base class, which
756 : is represented with a NOP_EXPR. */
757 0 : if (is_empty_class (type) && CLASS_TYPE_P (optype))
758 : {
759 0 : *empty_base = true;
760 0 : return op;
761 : }
762 : }
763 :
764 : return NULL_TREE;
765 : }
766 :
767 : // forked from gcc/cp/constexpr.cc cxx_fold_indirect_ref
768 :
769 : /* A less strict version of fold_indirect_ref_1, which requires cv-quals to
770 : match. We want to be less strict for simple *& folding; if we have a
771 : non-const temporary that we access through a const pointer, that should
772 : work. We handle this here rather than change fold_indirect_ref_1
773 : because we're dealing with things like ADDR_EXPR of INTEGER_CST which
774 : don't really make sense outside of constant expression evaluation. Also
775 : we want to allow folding to COMPONENT_REF, which could cause trouble
776 : with TBAA in fold_indirect_ref_1. */
777 :
778 : static tree
779 0 : rs_fold_indirect_ref (const constexpr_ctx *ctx, location_t loc, tree type,
780 : tree op0, bool *empty_base, tree *jump_target)
781 : {
782 0 : tree sub = op0;
783 0 : tree subtype;
784 :
785 : /* STRIP_NOPS, but stop if REINTERPRET_CAST_P. */
786 0 : while (CONVERT_EXPR_P (sub) || TREE_CODE (sub) == NON_LVALUE_EXPR
787 0 : || TREE_CODE (sub) == VIEW_CONVERT_EXPR)
788 : {
789 0 : if (TREE_CODE (sub) == NOP_EXPR && REINTERPRET_CAST_P (sub))
790 : return NULL_TREE;
791 0 : sub = TREE_OPERAND (sub, 0);
792 : }
793 :
794 0 : subtype = TREE_TYPE (sub);
795 0 : if (!INDIRECT_TYPE_P (subtype))
796 : return NULL_TREE;
797 :
798 : /* Canonicalizes the given OBJ/OFF pair by iteratively absorbing
799 : the innermost component into the offset until it would make the
800 : offset positive, so that cxx_fold_indirect_ref_1 can identify
801 : more folding opportunities. */
802 0 : auto canonicalize_obj_off = [] (tree &obj, tree &off) {
803 0 : while (TREE_CODE (obj) == COMPONENT_REF
804 0 : && (tree_int_cst_sign_bit (off) || integer_zerop (off)))
805 : {
806 0 : tree field = TREE_OPERAND (obj, 1);
807 0 : tree pos = byte_position (field);
808 0 : if (integer_zerop (off) && integer_nonzerop (pos))
809 : /* If the offset is already 0, keep going as long as the
810 : component is at position 0. */
811 : break;
812 0 : off = int_const_binop (PLUS_EXPR, off, pos);
813 0 : obj = TREE_OPERAND (obj, 0);
814 : }
815 0 : };
816 :
817 0 : if (TREE_CODE (sub) == ADDR_EXPR)
818 : {
819 0 : tree op = TREE_OPERAND (sub, 0);
820 0 : tree optype = TREE_TYPE (op);
821 :
822 : /* *&CONST_DECL -> to the value of the const decl. */
823 0 : if (TREE_CODE (op) == CONST_DECL)
824 0 : return DECL_INITIAL (op);
825 : /* *&p => p; make sure to handle *&"str"[cst] here. */
826 0 : if (similar_type_p (optype, type))
827 : {
828 0 : tree fop = fold_read_from_constant_string (op);
829 0 : if (fop)
830 : return fop;
831 : else
832 0 : return op;
833 : }
834 : else
835 : {
836 0 : tree off = integer_zero_node;
837 0 : canonicalize_obj_off (op, off);
838 0 : gcc_assert (integer_zerop (off));
839 0 : return fold_indirect_ref_1 (ctx, loc, type, op, 0, empty_base,
840 : jump_target);
841 : }
842 : }
843 0 : else if (TREE_CODE (sub) == POINTER_PLUS_EXPR
844 0 : && tree_fits_uhwi_p (TREE_OPERAND (sub, 1)))
845 : {
846 0 : tree op00 = TREE_OPERAND (sub, 0);
847 0 : tree off = TREE_OPERAND (sub, 1);
848 :
849 0 : STRIP_NOPS (op00);
850 0 : if (TREE_CODE (op00) == ADDR_EXPR)
851 : {
852 0 : tree obj = TREE_OPERAND (op00, 0);
853 0 : canonicalize_obj_off (obj, off);
854 0 : return fold_indirect_ref_1 (ctx, loc, type, obj, tree_to_uhwi (off),
855 : empty_base, jump_target);
856 : }
857 : }
858 : /* *(foo *)fooarrptr => (*fooarrptr)[0] */
859 0 : else if (TREE_CODE (TREE_TYPE (subtype)) == ARRAY_TYPE
860 0 : && similar_type_p (type, TREE_TYPE (TREE_TYPE (subtype))))
861 : {
862 0 : tree type_domain;
863 0 : tree min_val = size_zero_node;
864 0 : tree newsub = rs_fold_indirect_ref (ctx, loc, TREE_TYPE (subtype), sub,
865 : NULL, jump_target);
866 0 : if (newsub)
867 : sub = newsub;
868 : else
869 0 : sub = build1_loc (loc, INDIRECT_REF, TREE_TYPE (subtype), sub);
870 0 : type_domain = TYPE_DOMAIN (TREE_TYPE (sub));
871 0 : if (type_domain && TYPE_MIN_VALUE (type_domain))
872 0 : min_val = TYPE_MIN_VALUE (type_domain);
873 0 : return build4_loc (loc, ARRAY_REF, type, sub, min_val, NULL_TREE,
874 0 : NULL_TREE);
875 : }
876 :
877 : return NULL_TREE;
878 : }
879 :
880 : // forked from gcc/cp/constexpr.cc cxx_eval_indirect_ref
881 :
882 : static tree
883 0 : rs_eval_indirect_ref (const constexpr_ctx *ctx, tree t, bool lval,
884 : bool *non_constant_p, bool *overflow_p, tree *jump_target)
885 : {
886 0 : tree orig_op0 = TREE_OPERAND (t, 0);
887 0 : bool empty_base = false;
888 :
889 : /* We can handle a MEM_REF like an INDIRECT_REF, if MEM_REF's second
890 : operand is an integer-zero. Otherwise reject the MEM_REF for now. */
891 :
892 0 : if (TREE_CODE (t) == MEM_REF
893 0 : && (!TREE_OPERAND (t, 1) || !integer_zerop (TREE_OPERAND (t, 1))))
894 : {
895 0 : gcc_assert (ctx->quiet);
896 0 : *non_constant_p = true;
897 0 : return t;
898 : }
899 :
900 : /* First try to simplify it directly. */
901 0 : tree r = rs_fold_indirect_ref (ctx, EXPR_LOCATION (t), TREE_TYPE (t),
902 : orig_op0, &empty_base, jump_target);
903 0 : if (!r)
904 : {
905 : /* If that didn't work, evaluate the operand first. */
906 0 : tree op0 = eval_constant_expression (ctx, orig_op0,
907 : /*lval*/ false, non_constant_p,
908 : overflow_p, jump_target);
909 : /* Don't VERIFY_CONSTANT here. */
910 0 : if (*non_constant_p)
911 : return t;
912 :
913 0 : if (!lval && integer_zerop (op0))
914 : {
915 0 : if (!ctx->quiet)
916 0 : error ("dereferencing a null pointer");
917 0 : *non_constant_p = true;
918 0 : return t;
919 : }
920 :
921 0 : r = rs_fold_indirect_ref (ctx, EXPR_LOCATION (t), TREE_TYPE (t), op0,
922 : &empty_base, jump_target);
923 0 : if (r == NULL_TREE)
924 : {
925 : /* We couldn't fold to a constant value. Make sure it's not
926 : something we should have been able to fold. */
927 0 : tree sub = op0;
928 0 : STRIP_NOPS (sub);
929 0 : if (TREE_CODE (sub) == ADDR_EXPR)
930 : {
931 0 : gcc_assert (
932 : !similar_type_p (TREE_TYPE (TREE_TYPE (sub)), TREE_TYPE (t)));
933 : /* DR 1188 says we don't have to deal with this. */
934 0 : if (!ctx->quiet)
935 0 : error_at (rs_expr_loc_or_input_loc (t),
936 : "accessing value of %qE through a %qT glvalue in a "
937 : "constant expression",
938 0 : build_fold_indirect_ref (sub), TREE_TYPE (t));
939 0 : *non_constant_p = true;
940 0 : return t;
941 : }
942 :
943 0 : if (lval && op0 != orig_op0)
944 0 : return build1 (INDIRECT_REF, TREE_TYPE (t), op0);
945 0 : if (!lval)
946 0 : VERIFY_CONSTANT (t);
947 0 : return t;
948 : }
949 : }
950 :
951 0 : r = eval_constant_expression (ctx, r, lval, non_constant_p, overflow_p,
952 : jump_target);
953 0 : if (*non_constant_p)
954 : return t;
955 :
956 : /* If we're pulling out the value of an empty base, just return an empty
957 : CONSTRUCTOR. */
958 0 : if (empty_base && !lval)
959 : {
960 0 : r = build_constructor (TREE_TYPE (t), NULL);
961 0 : TREE_CONSTANT (r) = true;
962 : }
963 :
964 : return r;
965 : }
966 :
967 : // forked from gcc/cp/constexpr.cc cxx_eval_logical_expression
968 :
969 : /* Subroutine of cxx_eval_constant_expression.
970 : Evaluate a short-circuited logical expression T in the context
971 : of a given constexpr CALL. BAILOUT_VALUE is the value for
972 : early return. CONTINUE_VALUE is used here purely for
973 : sanity check purposes. */
974 :
975 : static tree
976 0 : eval_logical_expression (const constexpr_ctx *ctx, tree t, tree bailout_value,
977 : tree continue_value, bool lval, bool *non_constant_p,
978 : bool *overflow_p, tree *jump_target)
979 : {
980 0 : tree r;
981 0 : tree lhs = eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval,
982 : non_constant_p, overflow_p, jump_target);
983 0 : VERIFY_CONSTANT (lhs);
984 0 : if (tree_int_cst_equal (lhs, bailout_value))
985 : return lhs;
986 0 : gcc_assert (tree_int_cst_equal (lhs, continue_value));
987 0 : r = eval_constant_expression (ctx, TREE_OPERAND (t, 1), lval, non_constant_p,
988 : overflow_p, jump_target);
989 0 : VERIFY_CONSTANT (r);
990 : return r;
991 : }
992 :
993 : // forked from gcc/cp/constexp.rcc lookup_placeholder
994 :
995 : /* Find the object of TYPE under initialization in CTX. */
996 :
997 : static tree
998 0 : lookup_placeholder (const constexpr_ctx *ctx, bool lval, tree type)
999 : {
1000 0 : if (!ctx)
1001 : return NULL_TREE;
1002 :
1003 : /* Prefer the outermost matching object, but don't cross
1004 : CONSTRUCTOR_PLACEHOLDER_BOUNDARY constructors. */
1005 0 : if (ctx->ctor && !CONSTRUCTOR_PLACEHOLDER_BOUNDARY (ctx->ctor))
1006 0 : if (tree outer_ob = lookup_placeholder (ctx->parent, lval, type))
1007 : return outer_ob;
1008 :
1009 : /* We could use ctx->object unconditionally, but using ctx->ctor when we
1010 : can is a minor optimization. */
1011 0 : if (!lval && ctx->ctor && same_type_p (TREE_TYPE (ctx->ctor), type))
1012 0 : return ctx->ctor;
1013 :
1014 0 : if (!ctx->object)
1015 : return NULL_TREE;
1016 :
1017 : /* Since an object cannot have a field of its own type, we can search outward
1018 : from ctx->object to find the unique containing object of TYPE. */
1019 : tree ob = ctx->object;
1020 0 : while (ob)
1021 : {
1022 0 : if (same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (ob), type))
1023 : break;
1024 0 : if (handled_component_p (ob))
1025 0 : ob = TREE_OPERAND (ob, 0);
1026 : else
1027 : ob = NULL_TREE;
1028 : }
1029 :
1030 : return ob;
1031 : }
1032 :
1033 : // forked from gcc/cp/constexp.rcc inline_asm_in_constexpr_error
1034 :
1035 : /* Complain about an attempt to evaluate inline assembly. */
1036 :
1037 : static void
1038 0 : inline_asm_in_constexpr_error (location_t loc)
1039 : {
1040 0 : auto_diagnostic_group d;
1041 0 : error_at (loc, "inline assembly is not a constant expression");
1042 0 : inform (loc, "only unevaluated inline assembly is allowed in a "
1043 : "%<constexpr%> function in C++20");
1044 0 : }
1045 :
1046 : // forked from gcc/cp/constexpr.cc verify_ctor_sanity
1047 :
1048 : /* We're about to process an initializer for a class or array TYPE. Make
1049 : sure that CTX is set up appropriately. */
1050 :
1051 : static void
1052 0 : verify_ctor_sanity (const constexpr_ctx *ctx, tree type)
1053 : {
1054 : /* We don't bother building a ctor for an empty base subobject. */
1055 0 : if (is_empty_class (type))
1056 : return;
1057 :
1058 : /* We're in the middle of an initializer that might involve placeholders;
1059 : our caller should have created a CONSTRUCTOR for us to put the
1060 : initializer into. We will either return that constructor or T. */
1061 0 : gcc_assert (ctx->ctor);
1062 0 : gcc_assert (
1063 : same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (ctx->ctor)));
1064 : /* We used to check that ctx->ctor was empty, but that isn't the case when
1065 : the object is zero-initialized before calling the constructor. */
1066 0 : if (ctx->object)
1067 : {
1068 0 : tree otype = TREE_TYPE (ctx->object);
1069 0 : gcc_assert (same_type_ignoring_top_level_qualifiers_p (type, otype)
1070 : /* Handle flexible array members. */
1071 : || (TREE_CODE (otype) == ARRAY_TYPE
1072 : && TYPE_DOMAIN (otype) == NULL_TREE
1073 : && TREE_CODE (type) == ARRAY_TYPE
1074 : && (same_type_ignoring_top_level_qualifiers_p (
1075 : TREE_TYPE (type), TREE_TYPE (otype)))));
1076 : }
1077 0 : gcc_assert (!ctx->object || !DECL_P (ctx->object)
1078 : || *(ctx->global->values.get (ctx->object)) == ctx->ctor);
1079 : }
1080 :
1081 : // forked from gcc/cp/constexpr.cc array_index_cmp
1082 :
1083 : /* Some of the expressions fed to the constexpr mechanism are calls to
1084 : constructors, which have type void. In that case, return the type being
1085 : initialized by the constructor. */
1086 :
1087 : static tree
1088 0 : initialized_type (tree t)
1089 : {
1090 0 : if (TYPE_P (t))
1091 : return t;
1092 0 : tree type = TREE_TYPE (t);
1093 0 : if (TREE_CODE (t) == CALL_EXPR)
1094 : {
1095 : /* A constructor call has void type, so we need to look deeper. */
1096 0 : tree fn = get_function_named_in_call (t);
1097 0 : if (fn && TREE_CODE (fn) == FUNCTION_DECL && DECL_CXX_CONSTRUCTOR_P (fn))
1098 0 : type = DECL_CONTEXT (fn);
1099 : }
1100 0 : else if (TREE_CODE (t) == COMPOUND_EXPR)
1101 0 : return initialized_type (TREE_OPERAND (t, 1));
1102 :
1103 0 : return cv_unqualified (type);
1104 : }
1105 :
1106 : // forked from gcc/cp/constexpr.cc init_subob_ctx
1107 :
1108 : /* We're about to initialize element INDEX of an array or class from VALUE.
1109 : Set up NEW_CTX appropriately by adjusting .object to refer to the
1110 : subobject and creating a new CONSTRUCTOR if the element is itself
1111 : a class or array. */
1112 :
1113 : static void
1114 0 : init_subob_ctx (const constexpr_ctx *ctx, constexpr_ctx &new_ctx, tree index,
1115 : tree &value)
1116 : {
1117 0 : new_ctx = *ctx;
1118 :
1119 0 : if (index && TREE_CODE (index) != INTEGER_CST
1120 0 : && TREE_CODE (index) != FIELD_DECL && TREE_CODE (index) != RANGE_EXPR)
1121 : /* This won't have an element in the new CONSTRUCTOR. */
1122 : return;
1123 :
1124 0 : tree type = initialized_type (value);
1125 0 : if (!AGGREGATE_TYPE_P (type) && !VECTOR_TYPE_P (type))
1126 : /* A non-aggregate member doesn't get its own CONSTRUCTOR. */
1127 : return;
1128 :
1129 : /* The sub-aggregate initializer might contain a placeholder;
1130 : update object to refer to the subobject and ctor to refer to
1131 : the (newly created) sub-initializer. */
1132 0 : if (ctx->object)
1133 : {
1134 0 : if (index == NULL_TREE || TREE_CODE (index) == RANGE_EXPR)
1135 : /* There's no well-defined subobject for this index. */
1136 0 : new_ctx.object = NULL_TREE;
1137 : else
1138 : {
1139 : // Faisal: commenting this out as not sure if it's needed and it's
1140 : // huge new_ctx.object = build_ctor_subob_ref (index, type,
1141 : // ctx->object);
1142 : }
1143 : }
1144 0 : tree elt = build_constructor (type, NULL);
1145 0 : CONSTRUCTOR_NO_CLEARING (elt) = true;
1146 0 : new_ctx.ctor = elt;
1147 :
1148 0 : if (TREE_CODE (value) == TARGET_EXPR)
1149 : /* Avoid creating another CONSTRUCTOR when we expand the TARGET_EXPR. */
1150 0 : value = TARGET_EXPR_INITIAL (value);
1151 : }
1152 :
1153 : // forked from gcc/cp/constexpr.cc base_field_constructor_elt
1154 :
1155 : /* REF is a COMPONENT_REF designating a particular field. V is a vector of
1156 : CONSTRUCTOR elements to initialize (part of) an object containing that
1157 : field. Return a pointer to the constructor_elt corresponding to the
1158 : initialization of the field. */
1159 :
1160 : static constructor_elt *
1161 0 : base_field_constructor_elt (vec<constructor_elt, va_gc> *v, tree ref)
1162 : {
1163 0 : tree aggr = TREE_OPERAND (ref, 0);
1164 0 : tree field = TREE_OPERAND (ref, 1);
1165 0 : HOST_WIDE_INT i;
1166 0 : constructor_elt *ce;
1167 :
1168 0 : gcc_assert (TREE_CODE (ref) == COMPONENT_REF);
1169 :
1170 0 : if (TREE_CODE (aggr) == COMPONENT_REF)
1171 : {
1172 0 : constructor_elt *base_ce = base_field_constructor_elt (v, aggr);
1173 0 : v = CONSTRUCTOR_ELTS (base_ce->value);
1174 : }
1175 :
1176 0 : for (i = 0; vec_safe_iterate (v, i, &ce); ++i)
1177 0 : if (ce->index == field)
1178 0 : return ce;
1179 :
1180 0 : rust_unreachable ();
1181 : return NULL;
1182 : }
1183 :
1184 : /* Return a pointer to the constructor_elt of CTOR which matches INDEX. If no
1185 : matching constructor_elt exists, then add one to CTOR.
1186 :
1187 : As an optimization, if POS_HINT is non-negative then it is used as a guess
1188 : for the (integer) index of the matching constructor_elt within CTOR. */
1189 :
1190 : static constructor_elt *
1191 2 : get_or_insert_ctor_field (tree ctor, tree index, int pos_hint = -1)
1192 : {
1193 : /* Check the hint first. */
1194 0 : if (pos_hint >= 0 && (unsigned) pos_hint < CONSTRUCTOR_NELTS (ctor)
1195 2 : && CONSTRUCTOR_ELT (ctor, pos_hint)->index == index)
1196 : return CONSTRUCTOR_ELT (ctor, pos_hint);
1197 :
1198 2 : tree type = TREE_TYPE (ctor);
1199 2 : if (TREE_CODE (type) == VECTOR_TYPE && index == NULL_TREE)
1200 : {
1201 0 : CONSTRUCTOR_APPEND_ELT (CONSTRUCTOR_ELTS (ctor), index, NULL_TREE);
1202 0 : return &CONSTRUCTOR_ELTS (ctor)->last ();
1203 : }
1204 2 : else if (TREE_CODE (type) == ARRAY_TYPE || TREE_CODE (type) == VECTOR_TYPE)
1205 : {
1206 1 : if (TREE_CODE (index) == RANGE_EXPR)
1207 : {
1208 : /* Support for RANGE_EXPR index lookups is currently limited to
1209 : accessing an existing element via POS_HINT, or appending a new
1210 : element to the end of CTOR. ??? Support for other access
1211 : patterns may also be needed. */
1212 0 : vec<constructor_elt, va_gc> *elts = CONSTRUCTOR_ELTS (ctor);
1213 0 : if (vec_safe_length (elts))
1214 : {
1215 0 : tree lo = TREE_OPERAND (index, 0);
1216 0 : gcc_assert (array_index_cmp (elts->last ().index, lo) < 0);
1217 : }
1218 0 : CONSTRUCTOR_APPEND_ELT (elts, index, NULL_TREE);
1219 0 : return &elts->last ();
1220 : }
1221 :
1222 1 : HOST_WIDE_INT i = find_array_ctor_elt (ctor, index, /*insert*/ true);
1223 1 : gcc_assert (i >= 0);
1224 1 : constructor_elt *cep = CONSTRUCTOR_ELT (ctor, i);
1225 1 : gcc_assert (cep->index == NULL_TREE
1226 : || TREE_CODE (cep->index) != RANGE_EXPR);
1227 : return cep;
1228 : }
1229 : else
1230 : {
1231 1 : gcc_assert (
1232 : TREE_CODE (index) == FIELD_DECL
1233 : && (same_type_ignoring_top_level_qualifiers_p (DECL_CONTEXT (index),
1234 : TREE_TYPE (ctor))));
1235 :
1236 : /* We must keep the CONSTRUCTOR's ELTS in FIELD order.
1237 : Usually we meet initializers in that order, but it is
1238 : possible for base types to be placed not in program
1239 : order. */
1240 1 : tree fields = TYPE_FIELDS (DECL_CONTEXT (index));
1241 1 : unsigned HOST_WIDE_INT idx = 0;
1242 1 : constructor_elt *cep = NULL;
1243 :
1244 : /* Check if we're changing the active member of a union. */
1245 0 : if (TREE_CODE (type) == UNION_TYPE && CONSTRUCTOR_NELTS (ctor)
1246 1 : && CONSTRUCTOR_ELT (ctor, 0)->index != index)
1247 0 : vec_safe_truncate (CONSTRUCTOR_ELTS (ctor), 0);
1248 : /* If the bit offset of INDEX is larger than that of the last
1249 : constructor_elt, then we can just immediately append a new
1250 : constructor_elt to the end of CTOR. */
1251 1 : else if (CONSTRUCTOR_NELTS (ctor)
1252 2 : && tree_int_cst_compare (
1253 1 : bit_position (index),
1254 1 : bit_position (CONSTRUCTOR_ELTS (ctor)->last ().index))
1255 : > 0)
1256 : {
1257 0 : idx = CONSTRUCTOR_NELTS (ctor);
1258 0 : goto insert;
1259 : }
1260 :
1261 : /* Otherwise, we need to iterate over CTOR to find or insert INDEX
1262 : appropriately. */
1263 :
1264 1 : for (; vec_safe_iterate (CONSTRUCTOR_ELTS (ctor), idx, &cep);
1265 0 : idx++, fields = DECL_CHAIN (fields))
1266 : {
1267 1 : if (index == cep->index)
1268 1 : goto found;
1269 :
1270 : /* The field we're initializing must be on the field
1271 : list. Look to see if it is present before the
1272 : field the current ELT initializes. */
1273 0 : for (; fields != cep->index; fields = DECL_CHAIN (fields))
1274 0 : if (index == fields)
1275 0 : goto insert;
1276 : }
1277 : /* We fell off the end of the CONSTRUCTOR, so insert a new
1278 : entry at the end. */
1279 :
1280 0 : insert:
1281 0 : {
1282 0 : constructor_elt ce = {index, NULL_TREE};
1283 :
1284 0 : vec_safe_insert (CONSTRUCTOR_ELTS (ctor), idx, ce);
1285 0 : cep = CONSTRUCTOR_ELT (ctor, idx);
1286 : }
1287 1 : found:;
1288 :
1289 1 : return cep;
1290 : }
1291 : }
1292 :
1293 : // forked from gcc/cp/constexpr.cc cxx_eval_vector_conditional_expression
1294 :
1295 : /* Subroutine of cxx_eval_constant_expression.
1296 : Attempt to evaluate vector condition expressions. Unlike
1297 : cxx_eval_conditional_expression, VEC_COND_EXPR acts like a normal
1298 : ternary arithmetics operation, where all 3 arguments have to be
1299 : evaluated as constants and then folding computes the result from
1300 : them. */
1301 :
1302 : static tree
1303 0 : eval_vector_conditional_expression (const constexpr_ctx *ctx, tree t,
1304 : bool *non_constant_p, bool *overflow_p,
1305 : tree *jump_target)
1306 : {
1307 0 : tree arg1 = eval_constant_expression (ctx, TREE_OPERAND (t, 0),
1308 : /*lval*/ false, non_constant_p,
1309 : overflow_p, jump_target);
1310 0 : VERIFY_CONSTANT (arg1);
1311 0 : tree arg2 = eval_constant_expression (ctx, TREE_OPERAND (t, 1),
1312 : /*lval*/ false, non_constant_p,
1313 : overflow_p, jump_target);
1314 0 : VERIFY_CONSTANT (arg2);
1315 0 : tree arg3 = eval_constant_expression (ctx, TREE_OPERAND (t, 2),
1316 : /*lval*/ false, non_constant_p,
1317 : overflow_p, jump_target);
1318 0 : VERIFY_CONSTANT (arg3);
1319 0 : location_t loc = EXPR_LOCATION (t);
1320 0 : tree type = TREE_TYPE (t);
1321 0 : tree r = fold_ternary_loc (loc, VEC_COND_EXPR, type, arg1, arg2, arg3);
1322 0 : if (r == NULL_TREE)
1323 : {
1324 0 : if (arg1 == TREE_OPERAND (t, 0) && arg2 == TREE_OPERAND (t, 1)
1325 0 : && arg3 == TREE_OPERAND (t, 2))
1326 : r = t;
1327 : else
1328 0 : r = build3_loc (loc, VEC_COND_EXPR, type, arg1, arg2, arg3);
1329 : }
1330 0 : VERIFY_CONSTANT (r);
1331 : return r;
1332 : }
1333 :
1334 : // forked from gcc/cp/constexpr.cc cxx_eval_bare_aggregate
1335 :
1336 : /* Subroutine of cxx_eval_constant_expression.
1337 : The expression tree T denotes a C-style array or a C-style
1338 : aggregate. Reduce it to a constant expression. */
1339 :
1340 : static tree
1341 0 : eval_bare_aggregate (const constexpr_ctx *ctx, tree t, bool lval,
1342 : bool *non_constant_p, bool *overflow_p, tree *jump_target)
1343 : {
1344 0 : vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (t);
1345 0 : bool changed = false;
1346 0 : gcc_assert (!BRACE_ENCLOSED_INITIALIZER_P (t));
1347 0 : tree type = TREE_TYPE (t);
1348 :
1349 0 : constexpr_ctx new_ctx;
1350 0 : if (TYPE_PTRMEMFUNC_P (type) || VECTOR_TYPE_P (type))
1351 : {
1352 : /* We don't really need the ctx->ctor business for a PMF or
1353 : vector, but it's simpler to use the same code. */
1354 0 : new_ctx = *ctx;
1355 0 : new_ctx.ctor = build_constructor (type, NULL);
1356 0 : new_ctx.object = NULL_TREE;
1357 0 : ctx = &new_ctx;
1358 0 : };
1359 0 : verify_ctor_sanity (ctx, type);
1360 0 : vec<constructor_elt, va_gc> **p = &CONSTRUCTOR_ELTS (ctx->ctor);
1361 0 : vec_alloc (*p, vec_safe_length (v));
1362 :
1363 0 : if (CONSTRUCTOR_PLACEHOLDER_BOUNDARY (t))
1364 0 : CONSTRUCTOR_PLACEHOLDER_BOUNDARY (ctx->ctor) = 1;
1365 :
1366 : unsigned i;
1367 : tree index, value;
1368 : bool constant_p = true;
1369 : bool side_effects_p = false;
1370 0 : FOR_EACH_CONSTRUCTOR_ELT (v, i, index, value)
1371 : {
1372 0 : tree orig_value = value;
1373 : /* Like in cxx_eval_store_expression, omit entries for empty fields. */
1374 0 : bool no_slot = TREE_CODE (type) == RECORD_TYPE && is_empty_field (index);
1375 0 : if (no_slot)
1376 0 : new_ctx = *ctx;
1377 : else
1378 0 : init_subob_ctx (ctx, new_ctx, index, value);
1379 0 : int pos_hint = -1;
1380 0 : if (new_ctx.ctor != ctx->ctor)
1381 : {
1382 : /* If we built a new CONSTRUCTOR, attach it now so that other
1383 : initializers can refer to it. */
1384 0 : constructor_elt *cep = get_or_insert_ctor_field (ctx->ctor, index);
1385 0 : cep->value = new_ctx.ctor;
1386 0 : pos_hint = cep - (*p)->begin ();
1387 : }
1388 0 : else if (TREE_CODE (type) == UNION_TYPE)
1389 : /* Otherwise if we're constructing a non-aggregate union member, set
1390 : the active union member now so that we can later detect and diagnose
1391 : if its initializer attempts to activate another member. */
1392 0 : get_or_insert_ctor_field (ctx->ctor, index);
1393 0 : tree elt
1394 0 : = eval_constant_expression (&new_ctx, value, lval, non_constant_p,
1395 : overflow_p, jump_target);
1396 : /* Don't VERIFY_CONSTANT here. */
1397 0 : if (ctx->quiet && *non_constant_p)
1398 : break;
1399 0 : if (elt != orig_value)
1400 0 : changed = true;
1401 :
1402 0 : if (!TREE_CONSTANT (elt))
1403 0 : constant_p = false;
1404 0 : if (TREE_SIDE_EFFECTS (elt))
1405 0 : side_effects_p = true;
1406 0 : if (index && TREE_CODE (index) == COMPONENT_REF)
1407 : {
1408 : /* This is an initialization of a vfield inside a base
1409 : subaggregate that we already initialized; push this
1410 : initialization into the previous initialization. */
1411 0 : constructor_elt *inner = base_field_constructor_elt (*p, index);
1412 0 : inner->value = elt;
1413 0 : changed = true;
1414 0 : }
1415 0 : else if (index
1416 0 : && (TREE_CODE (index) == NOP_EXPR
1417 0 : || TREE_CODE (index) == POINTER_PLUS_EXPR))
1418 : {
1419 : /* This is an initializer for an empty base; now that we've
1420 : checked that it's constant, we can ignore it. */
1421 0 : gcc_assert (is_empty_class (TREE_TYPE (TREE_TYPE (index))));
1422 : changed = true;
1423 : }
1424 0 : else if (no_slot)
1425 : changed = true;
1426 : else
1427 : {
1428 0 : if (TREE_CODE (type) == UNION_TYPE && (*p)->last ().index != index)
1429 : /* The initializer erroneously changed the active union member that
1430 : we're initializing. */
1431 0 : gcc_assert (*non_constant_p);
1432 : else
1433 : {
1434 : /* The initializer might have mutated the underlying CONSTRUCTOR,
1435 : so recompute the location of the target constructer_elt. */
1436 0 : constructor_elt *cep
1437 0 : = get_or_insert_ctor_field (ctx->ctor, index, pos_hint);
1438 0 : cep->value = elt;
1439 : }
1440 :
1441 : /* Adding or replacing an element might change the ctor's flags. */
1442 0 : TREE_CONSTANT (ctx->ctor) = constant_p;
1443 0 : TREE_SIDE_EFFECTS (ctx->ctor) = side_effects_p;
1444 : }
1445 : }
1446 0 : if (*non_constant_p || !changed)
1447 : return t;
1448 0 : t = ctx->ctor;
1449 : /* We're done building this CONSTRUCTOR, so now we can interpret an
1450 : element without an explicit initializer as value-initialized. */
1451 0 : CONSTRUCTOR_NO_CLEARING (t) = false;
1452 0 : TREE_CONSTANT (t) = constant_p;
1453 0 : TREE_SIDE_EFFECTS (t) = side_effects_p;
1454 0 : if (VECTOR_TYPE_P (type))
1455 0 : t = fold (t);
1456 : return t;
1457 : }
1458 :
1459 : /* Subroutine of cxx_eval_constant_expression.
1460 : Like cxx_eval_unary_expression, except for trinary expressions. */
1461 :
1462 : static tree
1463 0 : cxx_eval_trinary_expression (const constexpr_ctx *ctx, tree t, bool lval,
1464 : bool *non_constant_p, bool *overflow_p,
1465 : tree *jump_target)
1466 : {
1467 0 : int i;
1468 0 : tree args[3];
1469 0 : tree val;
1470 :
1471 0 : for (i = 0; i < 3; i++)
1472 : {
1473 0 : args[i]
1474 0 : = eval_constant_expression (ctx, TREE_OPERAND (t, i), lval,
1475 : non_constant_p, overflow_p, jump_target);
1476 0 : VERIFY_CONSTANT (args[i]);
1477 : }
1478 :
1479 0 : val = fold_ternary_loc (EXPR_LOCATION (t), TREE_CODE (t), TREE_TYPE (t),
1480 : args[0], args[1], args[2]);
1481 0 : if (val == NULL_TREE)
1482 : return t;
1483 0 : VERIFY_CONSTANT (val);
1484 : return val;
1485 : }
1486 :
1487 : /* Return true if T is a valid constant initializer. If a CONSTRUCTOR
1488 : initializes all the members, the CONSTRUCTOR_NO_CLEARING flag will be
1489 : cleared.
1490 : FIXME speed this up, it's taking 16% of compile time on sieve testcase. */
1491 :
1492 : bool
1493 262676 : reduced_constant_expression_p (tree t)
1494 : {
1495 262676 : if (t == NULL_TREE)
1496 : return false;
1497 :
1498 262676 : switch (TREE_CODE (t))
1499 : {
1500 : case PTRMEM_CST:
1501 : /* Even if we can't lower this yet, it's constant. */
1502 : return true;
1503 :
1504 63 : case CONSTRUCTOR:
1505 : /* And we need to handle PTRMEM_CST wrapped in a CONSTRUCTOR. */
1506 63 : tree field;
1507 63 : if (CONSTRUCTOR_NO_CLEARING (t))
1508 : {
1509 0 : if (TREE_CODE (TREE_TYPE (t)) == VECTOR_TYPE)
1510 : /* An initialized vector would have a VECTOR_CST. */
1511 : return false;
1512 0 : else if (TREE_CODE (TREE_TYPE (t)) == ARRAY_TYPE)
1513 : {
1514 : /* There must be a valid constant initializer at every array
1515 : index. */
1516 0 : tree min = TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (t)));
1517 0 : tree max = TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (t)));
1518 0 : tree cursor = min;
1519 0 : for (auto &e : CONSTRUCTOR_ELTS (t))
1520 : {
1521 0 : if (!reduced_constant_expression_p (e.value))
1522 : return false;
1523 0 : if (array_index_cmp (cursor, e.index) != 0)
1524 : return false;
1525 0 : if (TREE_CODE (e.index) == RANGE_EXPR)
1526 0 : cursor = TREE_OPERAND (e.index, 1);
1527 0 : cursor = int_const_binop (PLUS_EXPR, cursor, size_one_node);
1528 : }
1529 0 : if (find_array_ctor_elt (t, max) == -1)
1530 : return false;
1531 0 : goto ok;
1532 : }
1533 0 : else if (TREE_CODE (TREE_TYPE (t)) == UNION_TYPE)
1534 : {
1535 0 : if (CONSTRUCTOR_NELTS (t) == 0)
1536 : /* An initialized union has a constructor element. */
1537 : return false;
1538 : /* And it only initializes one member. */
1539 : field = NULL_TREE;
1540 : }
1541 : else
1542 0 : field = next_initializable_field (TYPE_FIELDS (TREE_TYPE (t)));
1543 : }
1544 : else
1545 : field = NULL_TREE;
1546 550 : for (auto &e : CONSTRUCTOR_ELTS (t))
1547 : {
1548 : /* If VAL is null, we're in the middle of initializing this
1549 : element. */
1550 371 : if (!reduced_constant_expression_p (e.value))
1551 : return false;
1552 : /* Empty class field may or may not have an initializer. */
1553 371 : for (; field && e.index != field;
1554 0 : field = next_initializable_field (DECL_CHAIN (field)))
1555 0 : if (!is_really_empty_class (TREE_TYPE (field),
1556 : /*ignore_vptr*/ false))
1557 : return false;
1558 371 : if (field)
1559 0 : field = next_initializable_field (DECL_CHAIN (field));
1560 : }
1561 : /* There could be a non-empty field at the end. */
1562 63 : for (; field; field = next_initializable_field (DECL_CHAIN (field)))
1563 0 : if (!is_really_empty_class (TREE_TYPE (field), /*ignore_vptr*/ false))
1564 : return false;
1565 63 : ok:
1566 63 : if (CONSTRUCTOR_NO_CLEARING (t))
1567 : /* All the fields are initialized. */
1568 0 : CONSTRUCTOR_NO_CLEARING (t) = false;
1569 : return true;
1570 :
1571 262613 : default:
1572 : /* FIXME are we calling this too much? */
1573 262613 : return initializer_constant_valid_p (t, TREE_TYPE (t)) != NULL_TREE;
1574 : }
1575 : }
1576 :
1577 : /* TEMP is the constant value of a temporary object of type TYPE. Adjust
1578 : the type of the value to match. */
1579 :
1580 : static tree
1581 3 : adjust_temp_type (tree type, tree temp)
1582 : {
1583 3 : if (same_type_p (TREE_TYPE (temp), type))
1584 : return temp;
1585 :
1586 2 : gcc_assert (scalarish_type_p (type));
1587 : /* Now we know we're dealing with a scalar, and a prvalue of non-class
1588 : type is cv-unqualified. */
1589 2 : return fold_convert (cv_unqualified (type), temp);
1590 : }
1591 :
1592 : // forked from gcc/cp/constexpr.cc free_constructor
1593 :
1594 : /* If T is a CONSTRUCTOR, ggc_free T and any sub-CONSTRUCTORs. */
1595 :
1596 : static void
1597 0 : free_constructor (tree t)
1598 : {
1599 0 : if (!t || TREE_CODE (t) != CONSTRUCTOR)
1600 0 : return;
1601 0 : releasing_vec ctors;
1602 0 : vec_safe_push (ctors, t);
1603 0 : while (!ctors->is_empty ())
1604 : {
1605 0 : tree c = ctors->pop ();
1606 0 : if (vec<constructor_elt, va_gc> *elts = CONSTRUCTOR_ELTS (c))
1607 : {
1608 : constructor_elt *ce;
1609 0 : for (HOST_WIDE_INT i = 0; vec_safe_iterate (elts, i, &ce); ++i)
1610 0 : if (TREE_CODE (ce->value) == CONSTRUCTOR)
1611 0 : vec_safe_push (ctors, ce->value);
1612 0 : ggc_free (elts);
1613 : }
1614 0 : ggc_free (c);
1615 : }
1616 0 : }
1617 :
1618 : static tree eval_and_check_array_index (const constexpr_ctx *ctx, tree t,
1619 : bool allow_one_past,
1620 : bool *non_constant_p, bool *overflow_p,
1621 : tree *jump_target);
1622 :
1623 : // forked from gcc/cp/constexpr.cc cxx_eval_array_reference
1624 :
1625 : /* Subroutine of cxx_eval_constant_expression.
1626 : Attempt to reduce a reference to an array slot. */
1627 :
1628 : static tree
1629 9 : eval_array_reference (const constexpr_ctx *ctx, tree t, bool lval,
1630 : bool *non_constant_p, bool *overflow_p, tree *jump_target)
1631 : {
1632 9 : tree oldary = TREE_OPERAND (t, 0);
1633 9 : tree ary = eval_constant_expression (ctx, oldary, lval, non_constant_p,
1634 : overflow_p, jump_target);
1635 9 : if (*non_constant_p)
1636 : return t;
1637 9 : if (!lval && TREE_CODE (ary) == VIEW_CONVERT_EXPR
1638 0 : && VECTOR_TYPE_P (TREE_TYPE (TREE_OPERAND (ary, 0)))
1639 9 : && TREE_TYPE (t) == TREE_TYPE (TREE_TYPE (TREE_OPERAND (ary, 0))))
1640 0 : ary = TREE_OPERAND (ary, 0);
1641 :
1642 9 : tree oldidx = TREE_OPERAND (t, 1);
1643 9 : tree index = eval_and_check_array_index (ctx, t, lval, non_constant_p,
1644 : overflow_p, jump_target);
1645 9 : if (*non_constant_p)
1646 : return t;
1647 :
1648 8 : if (lval && ary == oldary && index == oldidx)
1649 : return t;
1650 8 : else if (lval)
1651 0 : return build4 (ARRAY_REF, TREE_TYPE (t), ary, index, NULL, NULL);
1652 :
1653 8 : unsigned len = 0, elem_nchars = 1;
1654 8 : tree elem_type = TREE_TYPE (TREE_TYPE (ary));
1655 8 : if (TREE_CODE (ary) == CONSTRUCTOR)
1656 8 : len = CONSTRUCTOR_NELTS (ary);
1657 0 : else if (TREE_CODE (ary) == STRING_CST)
1658 : {
1659 0 : elem_nchars
1660 0 : = (TYPE_PRECISION (elem_type) / TYPE_PRECISION (char_type_node));
1661 0 : len = (unsigned) TREE_STRING_LENGTH (ary) / elem_nchars;
1662 : }
1663 0 : else if (TREE_CODE (ary) == VECTOR_CST)
1664 : /* We don't create variable-length VECTOR_CSTs. */
1665 0 : len = VECTOR_CST_NELTS (ary).to_constant ();
1666 : else
1667 : {
1668 : /* We can't do anything with other tree codes, so use
1669 : VERIFY_CONSTANT to complain and fail. */
1670 0 : VERIFY_CONSTANT (ary);
1671 0 : rust_unreachable ();
1672 : }
1673 :
1674 8 : bool found;
1675 8 : HOST_WIDE_INT i = 0;
1676 8 : if (TREE_CODE (ary) == CONSTRUCTOR)
1677 : {
1678 8 : HOST_WIDE_INT ix = find_array_ctor_elt (ary, index);
1679 8 : found = (ix >= 0);
1680 8 : if (found)
1681 8 : i = ix;
1682 : }
1683 : else
1684 : {
1685 0 : i = tree_to_shwi (index);
1686 0 : found = (i < len);
1687 : }
1688 :
1689 8 : if (found)
1690 : {
1691 8 : tree r;
1692 8 : if (TREE_CODE (ary) == CONSTRUCTOR)
1693 8 : r = (*CONSTRUCTOR_ELTS (ary))[i].value;
1694 0 : else if (TREE_CODE (ary) == VECTOR_CST)
1695 0 : r = VECTOR_CST_ELT (ary, i);
1696 : else
1697 0 : r = extract_string_elt (ary, elem_nchars, i);
1698 :
1699 8 : if (r)
1700 : /* Don't VERIFY_CONSTANT here. */
1701 : return r;
1702 :
1703 : /* Otherwise the element doesn't have a value yet. */
1704 : }
1705 :
1706 : /* Not found. */
1707 :
1708 0 : if (TREE_CODE (ary) == CONSTRUCTOR && CONSTRUCTOR_NO_CLEARING (ary))
1709 : {
1710 : /* 'ary' is part of the aggregate initializer we're currently
1711 : building; if there's no initializer for this element yet,
1712 : that's an error. */
1713 0 : if (!ctx->quiet)
1714 0 : error ("accessing uninitialized array element");
1715 0 : *non_constant_p = true;
1716 0 : return t;
1717 : }
1718 :
1719 : /* If it's within the array bounds but doesn't have an explicit
1720 : initializer, it's initialized from {}. But use build_value_init
1721 : directly for non-aggregates to avoid creating a garbage CONSTRUCTOR. */
1722 0 : tree val = NULL_TREE;
1723 0 : sorry ("array size expression is not supported yet");
1724 :
1725 0 : constexpr_ctx new_ctx;
1726 0 : if (is_really_empty_class (elem_type, /*ignore_vptr*/ false))
1727 0 : return build_constructor (elem_type, NULL);
1728 : // else if (CP_AGGREGATE_TYPE_P (elem_type))
1729 : // {
1730 : // tree empty_ctor = build_constructor (init_list_type_node, NULL);
1731 : // //val = digest_init (elem_type, empty_ctor, tf_warning_or_error);
1732 : // }
1733 : // else
1734 : // val = build_value_init (elem_type, tf_warning_or_error);
1735 :
1736 0 : if (!SCALAR_TYPE_P (elem_type))
1737 : {
1738 0 : new_ctx = *ctx;
1739 0 : if (ctx->object)
1740 : /* If there was no object, don't add one: it could confuse us
1741 : into thinking we're modifying a const object. */
1742 0 : new_ctx.object = t;
1743 0 : new_ctx.ctor = build_constructor (elem_type, NULL);
1744 0 : ctx = &new_ctx;
1745 : }
1746 0 : t = eval_constant_expression (ctx, val, lval, non_constant_p, overflow_p,
1747 : jump_target);
1748 0 : if (!SCALAR_TYPE_P (elem_type) && t != ctx->ctor)
1749 0 : free_constructor (ctx->ctor);
1750 : return t;
1751 : }
1752 :
1753 : // forked from gcc/cp/constexpr.cc cxx_eval_component_reference
1754 :
1755 : /* Subroutine of cxx_eval_constant_expression.
1756 : Attempt to reduce a field access of a value of class type. */
1757 :
1758 : static tree
1759 5 : eval_component_reference (const constexpr_ctx *ctx, tree t, bool lval,
1760 : bool *non_constant_p, bool *overflow_p,
1761 : tree *jump_target)
1762 : {
1763 5 : unsigned HOST_WIDE_INT i;
1764 5 : tree field;
1765 5 : tree value;
1766 5 : tree part = TREE_OPERAND (t, 1);
1767 5 : tree orig_whole = TREE_OPERAND (t, 0);
1768 5 : tree whole = eval_constant_expression (ctx, orig_whole, lval, non_constant_p,
1769 : overflow_p, jump_target);
1770 5 : if (INDIRECT_REF_P (whole) && integer_zerop (TREE_OPERAND (whole, 0)))
1771 : {
1772 0 : if (!ctx->quiet)
1773 0 : error ("dereferencing a null pointer in %qE", orig_whole);
1774 0 : *non_constant_p = true;
1775 0 : return t;
1776 : }
1777 :
1778 5 : if (whole == orig_whole)
1779 : return t;
1780 5 : if (lval)
1781 0 : return fold_build3 (COMPONENT_REF, TREE_TYPE (t), whole, part, NULL_TREE);
1782 : /* Don't VERIFY_CONSTANT here; we only want to check that we got a
1783 : CONSTRUCTOR. */
1784 5 : if (!*non_constant_p && TREE_CODE (whole) != CONSTRUCTOR)
1785 : {
1786 0 : if (!ctx->quiet)
1787 0 : error ("%qE is not a constant expression", orig_whole);
1788 0 : *non_constant_p = true;
1789 : }
1790 5 : if (DECL_MUTABLE_P (part))
1791 : {
1792 0 : if (!ctx->quiet)
1793 0 : error ("mutable %qD is not usable in a constant expression", part);
1794 0 : *non_constant_p = true;
1795 : }
1796 5 : if (*non_constant_p)
1797 : return t;
1798 5 : bool pmf = TYPE_PTRMEMFUNC_P (TREE_TYPE (whole));
1799 6 : FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (whole), i, field, value)
1800 : {
1801 : /* Use name match for PMF fields, as a variant will have a
1802 : different FIELD_DECL with a different type. */
1803 6 : if (pmf ? DECL_NAME (field) == DECL_NAME (part) : field == part)
1804 : {
1805 5 : if (value)
1806 : {
1807 5 : STRIP_ANY_LOCATION_WRAPPER (value);
1808 5 : return value;
1809 : }
1810 : else
1811 : /* We're in the middle of initializing it. */
1812 : break;
1813 : }
1814 : }
1815 0 : if (TREE_CODE (TREE_TYPE (whole)) == UNION_TYPE
1816 0 : && CONSTRUCTOR_NELTS (whole) > 0)
1817 : {
1818 : /* DR 1188 says we don't have to deal with this. */
1819 0 : if (!ctx->quiet)
1820 : {
1821 0 : constructor_elt *cep = CONSTRUCTOR_ELT (whole, 0);
1822 0 : if (cep->value == NULL_TREE)
1823 0 : error ("accessing uninitialized member %qD", part);
1824 : else
1825 0 : error ("accessing %qD member instead of initialized %qD member in "
1826 : "constant expression",
1827 : part, cep->index);
1828 : }
1829 0 : *non_constant_p = true;
1830 0 : return t;
1831 : }
1832 :
1833 : /* We only create a CONSTRUCTOR for a subobject when we modify it, so empty
1834 : classes never get represented; throw together a value now. */
1835 0 : if (is_really_empty_class (TREE_TYPE (t), /*ignore_vptr*/ false))
1836 0 : return build_constructor (TREE_TYPE (t), NULL);
1837 :
1838 0 : gcc_assert (DECL_CONTEXT (part) == TYPE_MAIN_VARIANT (TREE_TYPE (whole)));
1839 :
1840 0 : if (CONSTRUCTOR_NO_CLEARING (whole))
1841 : {
1842 : /* 'whole' is part of the aggregate initializer we're currently
1843 : building; if there's no initializer for this member yet, that's an
1844 : error. */
1845 0 : if (!ctx->quiet)
1846 0 : error ("accessing uninitialized member %qD", part);
1847 0 : *non_constant_p = true;
1848 0 : return t;
1849 : }
1850 :
1851 0 : value = NULL_TREE;
1852 0 : sorry ("constant folding not supported for this tree code");
1853 : /* If there's no explicit init for this field, it's value-initialized. */
1854 : // Faisal: commenting this out as not sure if we need this but we need to come
1855 : // back to handle this to assign suitable value to value before sending it in
1856 : // eval_constant_expression below
1857 : // value = build_value_init (TREE_TYPE (t), tf_warning_or_error);
1858 0 : return eval_constant_expression (ctx, value, lval, non_constant_p, overflow_p,
1859 0 : jump_target);
1860 : }
1861 :
1862 : /* Subroutine of cxx_eval_statement_list. Determine whether the statement
1863 : STMT matches *jump_target. If we're looking for a case label and we see
1864 : the default label, note it in ctx->css_state. */
1865 :
1866 : static bool
1867 0 : label_matches (const constexpr_ctx *ctx, tree *jump_target, tree stmt)
1868 : {
1869 0 : switch (TREE_CODE (*jump_target))
1870 : {
1871 0 : case LABEL_DECL:
1872 0 : if (TREE_CODE (stmt) == LABEL_EXPR
1873 0 : && LABEL_EXPR_LABEL (stmt) == *jump_target)
1874 : return true;
1875 : break;
1876 :
1877 0 : case INTEGER_CST:
1878 0 : if (TREE_CODE (stmt) == CASE_LABEL_EXPR)
1879 : {
1880 0 : gcc_assert (ctx->css_state != NULL);
1881 0 : if (!CASE_LOW (stmt))
1882 : {
1883 : /* default: should appear just once in a SWITCH_EXPR
1884 : body (excluding nested SWITCH_EXPR). */
1885 0 : gcc_assert (*ctx->css_state != css_default_seen);
1886 : /* When evaluating SWITCH_EXPR body for the second time,
1887 : return true for the default: label. */
1888 0 : if (*ctx->css_state == css_default_processing)
1889 : return true;
1890 0 : *ctx->css_state = css_default_seen;
1891 : }
1892 0 : else if (CASE_HIGH (stmt))
1893 : {
1894 0 : if (tree_int_cst_le (CASE_LOW (stmt), *jump_target)
1895 0 : && tree_int_cst_le (*jump_target, CASE_HIGH (stmt)))
1896 : return true;
1897 : }
1898 0 : else if (tree_int_cst_equal (*jump_target, CASE_LOW (stmt)))
1899 : return true;
1900 : }
1901 : break;
1902 :
1903 : case BREAK_STMT:
1904 : case CONTINUE_STMT:
1905 : /* These two are handled directly in cxx_eval_loop_expr by testing
1906 : breaks (jump_target) or continues (jump_target). */
1907 : break;
1908 :
1909 0 : default:
1910 0 : rust_unreachable ();
1911 : }
1912 : return false;
1913 : }
1914 :
1915 : static tree
1916 1854717 : eval_constant_expression (const constexpr_ctx *ctx, tree t, bool lval,
1917 : bool *non_constant_p, bool *overflow_p,
1918 : tree *jump_target)
1919 : {
1920 1854717 : if (jump_target && *jump_target)
1921 : {
1922 : /* If we are jumping, ignore all statements/expressions except those
1923 : that could have LABEL_EXPR or CASE_LABEL_EXPR in their bodies. */
1924 0 : switch (TREE_CODE (t))
1925 : {
1926 : case BIND_EXPR:
1927 : case STATEMENT_LIST:
1928 : case LOOP_EXPR:
1929 : case COND_EXPR:
1930 : case IF_STMT:
1931 : case DO_STMT:
1932 : case WHILE_STMT:
1933 : case FOR_STMT:
1934 : break;
1935 0 : case LABEL_EXPR:
1936 0 : case CASE_LABEL_EXPR:
1937 0 : if (label_matches (ctx, jump_target, t))
1938 : /* Found it. */
1939 0 : *jump_target = NULL_TREE;
1940 0 : return NULL_TREE;
1941 : default:
1942 : return NULL_TREE;
1943 : }
1944 : }
1945 1854717 : if (error_operand_p (t))
1946 : {
1947 3 : *non_constant_p = true;
1948 3 : return t;
1949 : }
1950 :
1951 1854714 : location_t loc = EXPR_LOCATION (t);
1952 :
1953 1854714 : if (t == NULL_TREE)
1954 : return NULL_TREE;
1955 :
1956 1592570 : if (CONSTANT_CLASS_P (t))
1957 : {
1958 265815 : if (TREE_OVERFLOW (t))
1959 : {
1960 0 : error_at (loc, "overflow in constant expression");
1961 0 : return t;
1962 : }
1963 :
1964 : return t;
1965 : }
1966 :
1967 : // Avoid excessively long constexpr evaluations
1968 1326755 : if (++ctx->global->constexpr_ops_count >= constexpr_ops_limit)
1969 : {
1970 0 : rust_error_at (
1971 : loc,
1972 : "%<constexpr%> evaluation operation count exceeds limit of "
1973 : "%wd (use %<-fconstexpr-ops-limit=%> to increase the limit)",
1974 : constexpr_ops_limit);
1975 :
1976 0 : return t;
1977 : }
1978 :
1979 1326755 : constexpr_ctx new_ctx;
1980 1326755 : tree r = t;
1981 1326755 : tree_code tcode = TREE_CODE (t);
1982 1326755 : switch (tcode)
1983 : {
1984 50 : case VAR_DECL:
1985 50 : if (DECL_HAS_VALUE_EXPR_P (t))
1986 : {
1987 0 : r = DECL_VALUE_EXPR (t);
1988 0 : return eval_constant_expression (ctx, r, lval, non_constant_p,
1989 0 : overflow_p, jump_target);
1990 : }
1991 : /* fall through */
1992 1346 : case CONST_DECL:
1993 : /* We used to not check lval for CONST_DECL, but darwin.cc uses
1994 : CONST_DECL for aggregate constants. */
1995 1346 : if (lval)
1996 : return t;
1997 1331 : else if (t == ctx->object)
1998 0 : return ctx->ctor;
1999 1331 : if (VAR_P (t))
2000 : {
2001 35 : if (tree v = ctx->global->get_value (t))
2002 : {
2003 34 : r = v;
2004 34 : break;
2005 : }
2006 : }
2007 1297 : if (COMPLETE_TYPE_P (TREE_TYPE (t))
2008 1297 : && is_really_empty_class (TREE_TYPE (t), /*ignore_vptr*/ false))
2009 : {
2010 : /* If the class is empty, we aren't actually loading anything. */
2011 0 : r = build_constructor (TREE_TYPE (t), NULL);
2012 0 : TREE_CONSTANT (r) = true;
2013 : }
2014 1297 : else if (ctx->strict)
2015 1297 : r = decl_really_constant_value (t, /*unshare_p=*/false);
2016 : else
2017 0 : r = decl_constant_value (t, /*unshare_p=*/false);
2018 1297 : if (TREE_CODE (r) == TARGET_EXPR
2019 1297 : && TREE_CODE (TARGET_EXPR_INITIAL (r)) == CONSTRUCTOR)
2020 0 : r = TARGET_EXPR_INITIAL (r);
2021 1297 : if (DECL_P (r) && !(VAR_P (t) && TYPE_REF_P (TREE_TYPE (t))))
2022 : {
2023 1 : if (!ctx->quiet)
2024 1 : non_const_var_error (loc, r);
2025 1 : *non_constant_p = true;
2026 : }
2027 : break;
2028 :
2029 35 : case PARM_DECL:
2030 35 : if (lval && !TYPE_REF_P (TREE_TYPE (t)))
2031 : /* glvalue use. */;
2032 25 : else if (tree *p = ctx->global->values.get (r))
2033 25 : r = *p;
2034 0 : else if (lval)
2035 : /* Defer in case this is only used for its type. */;
2036 0 : else if (COMPLETE_TYPE_P (TREE_TYPE (t))
2037 0 : && is_really_empty_class (TREE_TYPE (t), /*ignore_vptr*/ false))
2038 : {
2039 : /* If the class is empty, we aren't actually loading anything. */
2040 0 : r = build_constructor (TREE_TYPE (t), NULL);
2041 0 : TREE_CONSTANT (r) = true;
2042 : }
2043 : else
2044 : {
2045 0 : if (!ctx->quiet)
2046 0 : error ("%qE is not a constant expression", t);
2047 0 : *non_constant_p = true;
2048 : }
2049 : break;
2050 :
2051 45 : case POINTER_PLUS_EXPR:
2052 45 : case POINTER_DIFF_EXPR:
2053 45 : case PLUS_EXPR:
2054 45 : case MINUS_EXPR:
2055 45 : case MULT_EXPR:
2056 45 : case TRUNC_DIV_EXPR:
2057 45 : case CEIL_DIV_EXPR:
2058 45 : case FLOOR_DIV_EXPR:
2059 45 : case ROUND_DIV_EXPR:
2060 45 : case TRUNC_MOD_EXPR:
2061 45 : case CEIL_MOD_EXPR:
2062 45 : case ROUND_MOD_EXPR:
2063 45 : case RDIV_EXPR:
2064 45 : case EXACT_DIV_EXPR:
2065 45 : case MIN_EXPR:
2066 45 : case MAX_EXPR:
2067 45 : case LSHIFT_EXPR:
2068 45 : case RSHIFT_EXPR:
2069 45 : case LROTATE_EXPR:
2070 45 : case RROTATE_EXPR:
2071 45 : case BIT_IOR_EXPR:
2072 45 : case BIT_XOR_EXPR:
2073 45 : case BIT_AND_EXPR:
2074 45 : case TRUTH_XOR_EXPR:
2075 45 : case LT_EXPR:
2076 45 : case LE_EXPR:
2077 45 : case GT_EXPR:
2078 45 : case GE_EXPR:
2079 45 : case EQ_EXPR:
2080 45 : case NE_EXPR:
2081 45 : case SPACESHIP_EXPR:
2082 45 : case UNORDERED_EXPR:
2083 45 : case ORDERED_EXPR:
2084 45 : case UNLT_EXPR:
2085 45 : case UNLE_EXPR:
2086 45 : case UNGT_EXPR:
2087 45 : case UNGE_EXPR:
2088 45 : case UNEQ_EXPR:
2089 45 : case LTGT_EXPR:
2090 45 : case RANGE_EXPR:
2091 45 : case COMPLEX_EXPR:
2092 45 : r = eval_binary_expression (ctx, t, lval, non_constant_p, overflow_p,
2093 : jump_target);
2094 45 : break;
2095 :
2096 : /* fold can introduce non-IF versions of these; still treat them as
2097 : short-circuiting. */
2098 0 : case TRUTH_AND_EXPR:
2099 0 : case TRUTH_ANDIF_EXPR:
2100 0 : r = eval_logical_expression (ctx, t, boolean_false_node,
2101 : boolean_true_node, lval, non_constant_p,
2102 : overflow_p, jump_target);
2103 0 : break;
2104 :
2105 0 : case TRUTH_OR_EXPR:
2106 0 : case TRUTH_ORIF_EXPR:
2107 0 : r = eval_logical_expression (ctx, t, boolean_true_node,
2108 : boolean_false_node, lval, non_constant_p,
2109 : overflow_p, jump_target);
2110 0 : break;
2111 :
2112 0 : case TARGET_EXPR:
2113 0 : {
2114 0 : tree type = TREE_TYPE (t);
2115 :
2116 0 : if (!literal_type_p (type))
2117 : {
2118 0 : if (!ctx->quiet)
2119 : {
2120 0 : auto_diagnostic_group d;
2121 0 : error ("temporary of non-literal type %qT in a "
2122 : "constant expression",
2123 : type);
2124 0 : explain_non_literal_class (type);
2125 0 : }
2126 0 : *non_constant_p = true;
2127 0 : break;
2128 : }
2129 0 : gcc_checking_assert (!TARGET_EXPR_DIRECT_INIT_P (t));
2130 : /* Avoid evaluating a TARGET_EXPR more than once. */
2131 0 : tree slot = TARGET_EXPR_SLOT (t);
2132 0 : if (tree *p = ctx->global->values.get (slot))
2133 : {
2134 0 : if (lval)
2135 0 : return slot;
2136 0 : r = *p;
2137 0 : break;
2138 : }
2139 0 : if ((AGGREGATE_TYPE_P (type) || VECTOR_TYPE_P (type)))
2140 : {
2141 : /* We're being expanded without an explicit target, so start
2142 : initializing a new object; expansion with an explicit target
2143 : strips the TARGET_EXPR before we get here. */
2144 0 : new_ctx = *ctx;
2145 : /* Link CTX to NEW_CTX so that lookup_placeholder can resolve
2146 : any PLACEHOLDER_EXPR within the initializer that refers to the
2147 : former object under construction. */
2148 0 : new_ctx.parent = ctx;
2149 0 : new_ctx.ctor = build_constructor (type, NULL);
2150 0 : CONSTRUCTOR_NO_CLEARING (new_ctx.ctor) = true;
2151 0 : new_ctx.object = slot;
2152 0 : ctx->global->values.put (new_ctx.object, new_ctx.ctor);
2153 0 : ctx = &new_ctx;
2154 : }
2155 : /* Pass false for 'lval' because this indicates
2156 : initialization of a temporary. */
2157 0 : r = eval_constant_expression (ctx, TREE_OPERAND (t, 1), false,
2158 : non_constant_p, overflow_p, jump_target);
2159 0 : if (*non_constant_p)
2160 : break;
2161 : /* Adjust the type of the result to the type of the temporary. */
2162 0 : r = adjust_temp_type (type, r);
2163 0 : if (TARGET_EXPR_CLEANUP (t) && !CLEANUP_EH_ONLY (t))
2164 0 : ctx->global->cleanups->safe_push (TARGET_EXPR_CLEANUP (t));
2165 0 : r = unshare_constructor (r);
2166 0 : ctx->global->values.put (slot, r);
2167 0 : if (ctx->save_exprs)
2168 0 : ctx->save_exprs->safe_push (slot);
2169 0 : if (lval)
2170 : return slot;
2171 : }
2172 0 : break;
2173 :
2174 2103 : case CALL_EXPR:
2175 2103 : r = eval_call_expression (ctx, t, lval, non_constant_p, overflow_p,
2176 : jump_target);
2177 2103 : break;
2178 :
2179 2094 : case RETURN_EXPR:
2180 2094 : if (TREE_OPERAND (t, 0) != NULL_TREE)
2181 2094 : r = eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval,
2182 : non_constant_p, overflow_p, jump_target);
2183 : /* FALLTHRU */
2184 2094 : case BREAK_STMT:
2185 2094 : case CONTINUE_STMT:
2186 2094 : if (jump_target)
2187 2094 : *jump_target = t;
2188 : else
2189 : {
2190 : /* Can happen with ({ return true; }) && false; passed to
2191 : maybe_constant_value. There is nothing to jump over in this
2192 : case, and the bug will be diagnosed later. */
2193 0 : gcc_assert (ctx->quiet);
2194 0 : *non_constant_p = true;
2195 : }
2196 : break;
2197 :
2198 1806 : case DECL_EXPR:
2199 1806 : {
2200 1806 : r = DECL_EXPR_DECL (t);
2201 :
2202 1806 : if (AGGREGATE_TYPE_P (TREE_TYPE (r)) || VECTOR_TYPE_P (TREE_TYPE (r)))
2203 : {
2204 68 : new_ctx = *ctx;
2205 68 : new_ctx.object = r;
2206 68 : new_ctx.ctor = build_constructor (TREE_TYPE (r), NULL);
2207 68 : CONSTRUCTOR_NO_CLEARING (new_ctx.ctor) = true;
2208 68 : ctx->global->values.put (r, new_ctx.ctor);
2209 68 : ctx = &new_ctx;
2210 : }
2211 :
2212 1806 : if (tree init = DECL_INITIAL (r))
2213 : {
2214 26 : init = eval_constant_expression (ctx, init, false, non_constant_p,
2215 : overflow_p, jump_target);
2216 : /* Don't share a CONSTRUCTOR that might be changed. */
2217 26 : init = unshare_constructor (init);
2218 : /* Remember that a constant object's constructor has already
2219 : run. */
2220 26 : if (CLASS_TYPE_P (TREE_TYPE (r)) && RS_TYPE_CONST_P (TREE_TYPE (r)))
2221 0 : TREE_READONLY (init) = true;
2222 26 : ctx->global->values.put (r, init);
2223 : }
2224 1780 : else if (ctx == &new_ctx)
2225 : /* We gave it a CONSTRUCTOR above. */;
2226 : else
2227 1713 : ctx->global->values.put (r, NULL_TREE);
2228 : }
2229 1806 : break;
2230 :
2231 : /* These differ from cxx_eval_unary_expression in that this doesn't
2232 : check for a constant operand or result; an address can be
2233 : constant without its operand being, and vice versa. */
2234 0 : case MEM_REF:
2235 0 : case INDIRECT_REF:
2236 0 : r = rs_eval_indirect_ref (ctx, t, lval, non_constant_p, overflow_p,
2237 : jump_target);
2238 0 : break;
2239 :
2240 0 : case VEC_PERM_EXPR:
2241 0 : r = cxx_eval_trinary_expression (ctx, t, lval, non_constant_p, overflow_p,
2242 : jump_target);
2243 0 : break;
2244 :
2245 0 : case PAREN_EXPR:
2246 0 : gcc_assert (!REF_PARENTHESIZED_P (t));
2247 : /* A PAREN_EXPR resulting from __builtin_assoc_barrier has no effect in
2248 : constant expressions since it's unaffected by -fassociative-math. */
2249 0 : r = eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval,
2250 : non_constant_p, overflow_p, jump_target);
2251 0 : break;
2252 :
2253 2120 : case MODIFY_EXPR:
2254 2120 : r = eval_store_expression (ctx, t, false, non_constant_p, overflow_p,
2255 : jump_target);
2256 2120 : break;
2257 :
2258 264281 : case STATEMENT_LIST:
2259 264281 : new_ctx = *ctx;
2260 264281 : new_ctx.ctor = new_ctx.object = NULL_TREE;
2261 264281 : return eval_statement_list (&new_ctx, t, non_constant_p, overflow_p,
2262 264281 : jump_target);
2263 :
2264 526425 : case BIND_EXPR:
2265 526425 : return eval_constant_expression (ctx, BIND_EXPR_BODY (t), lval,
2266 526425 : non_constant_p, overflow_p, jump_target);
2267 :
2268 0 : case OBJ_TYPE_REF:
2269 : /* Virtual function lookup. We don't need to do anything fancy. */
2270 0 : return eval_constant_expression (ctx, OBJ_TYPE_REF_EXPR (t), lval,
2271 0 : non_constant_p, overflow_p, jump_target);
2272 :
2273 262149 : case EXIT_EXPR:
2274 262149 : {
2275 262149 : tree cond = TREE_OPERAND (t, 0);
2276 262149 : cond
2277 262149 : = eval_constant_expression (ctx, cond, /*lval*/ false, non_constant_p,
2278 : overflow_p, jump_target);
2279 262149 : VERIFY_CONSTANT (cond);
2280 262149 : if (integer_nonzerop (cond))
2281 3 : *jump_target = t;
2282 : }
2283 : break;
2284 :
2285 2091 : case RESULT_DECL:
2286 2091 : if (lval)
2287 : return t;
2288 : /* We ask for an rvalue for the RESULT_DECL when indirecting
2289 : through an invisible reference, or in named return value
2290 : optimization. */
2291 0 : if (tree *p = ctx->global->values.get (t))
2292 0 : return *p;
2293 : else
2294 : {
2295 0 : if (!ctx->quiet)
2296 0 : error ("%qE is not a constant expression", t);
2297 0 : *non_constant_p = true;
2298 : }
2299 0 : break;
2300 :
2301 0 : case SAVE_EXPR:
2302 : /* Avoid evaluating a SAVE_EXPR more than once. */
2303 0 : if (tree *p = ctx->global->values.get (t))
2304 0 : r = *p;
2305 : else
2306 : {
2307 0 : r = eval_constant_expression (ctx, TREE_OPERAND (t, 0), false,
2308 : non_constant_p, overflow_p,
2309 : jump_target);
2310 0 : if (*non_constant_p)
2311 : break;
2312 0 : ctx->global->values.put (t, r);
2313 0 : if (ctx->save_exprs)
2314 0 : ctx->save_exprs->safe_push (t);
2315 : }
2316 : break;
2317 :
2318 2 : case ADDR_EXPR:
2319 2 : {
2320 2 : tree oldop = TREE_OPERAND (t, 0);
2321 2 : tree op = eval_constant_expression (ctx, oldop,
2322 : /*lval*/ true, non_constant_p,
2323 : overflow_p, jump_target);
2324 : /* Don't VERIFY_CONSTANT here. */
2325 2 : if (*non_constant_p)
2326 : return t;
2327 : /* This function does more aggressive folding than fold itself. */
2328 1 : r = build_fold_addr_expr_with_type (op, TREE_TYPE (t));
2329 1 : if (TREE_CODE (r) == ADDR_EXPR && TREE_OPERAND (r, 0) == oldop)
2330 : {
2331 1 : ggc_free (r);
2332 1 : return t;
2333 : }
2334 : break;
2335 : }
2336 :
2337 0 : case COMPOUND_EXPR:
2338 0 : {
2339 : /* check_return_expr sometimes wraps a TARGET_EXPR in a
2340 : COMPOUND_EXPR; don't get confused. Also handle EMPTY_CLASS_EXPR
2341 : introduced by build_call_a. */
2342 0 : tree op0 = TREE_OPERAND (t, 0);
2343 0 : tree op1 = TREE_OPERAND (t, 1);
2344 0 : STRIP_NOPS (op1);
2345 0 : if ((TREE_CODE (op0) == TARGET_EXPR && op1 == TARGET_EXPR_SLOT (op0))
2346 0 : || TREE_CODE (op1) == EMPTY_CLASS_EXPR)
2347 0 : r = eval_constant_expression (ctx, op0, lval, non_constant_p,
2348 : overflow_p, jump_target);
2349 : else
2350 : {
2351 : /* Check that the LHS is constant and then discard it. */
2352 0 : eval_constant_expression (ctx, op0, true, non_constant_p,
2353 : overflow_p, jump_target);
2354 0 : if (*non_constant_p)
2355 : return t;
2356 0 : op1 = TREE_OPERAND (t, 1);
2357 0 : r = eval_constant_expression (ctx, op1, lval, non_constant_p,
2358 : overflow_p, jump_target);
2359 : }
2360 : }
2361 : break;
2362 :
2363 0 : case REALPART_EXPR:
2364 0 : case IMAGPART_EXPR:
2365 0 : if (lval)
2366 : {
2367 0 : r = eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval,
2368 : non_constant_p, overflow_p,
2369 : jump_target);
2370 0 : if (r == error_mark_node)
2371 : ;
2372 0 : else if (r == TREE_OPERAND (t, 0))
2373 0 : r = t;
2374 : else
2375 0 : r = fold_build1 (TREE_CODE (t), TREE_TYPE (t), r);
2376 : break;
2377 : }
2378 : /* FALLTHRU */
2379 7 : case CONJ_EXPR:
2380 7 : case FIX_TRUNC_EXPR:
2381 7 : case FLOAT_EXPR:
2382 7 : case NEGATE_EXPR:
2383 7 : case ABS_EXPR:
2384 7 : case ABSU_EXPR:
2385 7 : case BIT_NOT_EXPR:
2386 7 : case TRUTH_NOT_EXPR:
2387 7 : case FIXED_CONVERT_EXPR:
2388 7 : r = eval_unary_expression (ctx, t, lval, non_constant_p, overflow_p,
2389 : jump_target);
2390 7 : break;
2391 :
2392 4 : case LOOP_EXPR:
2393 4 : case WHILE_STMT:
2394 4 : case FOR_STMT:
2395 4 : eval_loop_expr (ctx, t, non_constant_p, overflow_p, jump_target);
2396 4 : break;
2397 :
2398 0 : case SWITCH_EXPR:
2399 0 : case SWITCH_STMT:
2400 0 : eval_switch_expr (ctx, t, non_constant_p, overflow_p, jump_target);
2401 0 : break;
2402 :
2403 9 : case ARRAY_REF:
2404 9 : r = eval_array_reference (ctx, t, lval, non_constant_p, overflow_p,
2405 : jump_target);
2406 9 : break;
2407 :
2408 5 : case COMPONENT_REF:
2409 5 : if (is_overloaded_fn (t))
2410 : {
2411 : /* We can only get here in checking mode via
2412 : build_non_dependent_expr, because any expression that
2413 : calls or takes the address of the function will have
2414 : pulled a FUNCTION_DECL out of the COMPONENT_REF. */
2415 0 : gcc_checking_assert (ctx->quiet || errorcount);
2416 0 : *non_constant_p = true;
2417 0 : return t;
2418 : }
2419 5 : r = eval_component_reference (ctx, t, lval, non_constant_p, overflow_p,
2420 : jump_target);
2421 5 : break;
2422 :
2423 0 : case BIT_FIELD_REF:
2424 0 : r = eval_bit_field_ref (ctx, t, lval, non_constant_p, overflow_p,
2425 : jump_target);
2426 0 : break;
2427 :
2428 16 : case COND_EXPR:
2429 16 : case IF_STMT: // comes from cp-tree.def
2430 16 : if (jump_target && *jump_target)
2431 : {
2432 0 : tree orig_jump = *jump_target;
2433 0 : tree arg = ((TREE_CODE (t) != IF_STMT || TREE_OPERAND (t, 1))
2434 0 : ? TREE_OPERAND (t, 1)
2435 0 : : void_node);
2436 : /* When jumping to a label, the label might be either in the
2437 : then or else blocks, so process then block first in skipping
2438 : mode first, and if we are still in the skipping mode at its end,
2439 : process the else block too. */
2440 0 : r = eval_constant_expression (ctx, arg, lval, non_constant_p,
2441 : overflow_p, jump_target);
2442 : /* It's possible that we found the label in the then block. But
2443 : it could have been followed by another jumping statement, e.g.
2444 : say we're looking for case 1:
2445 : if (cond)
2446 : {
2447 : // skipped statements
2448 : case 1:; // clears up *jump_target
2449 : return 1; // and sets it to a RETURN_EXPR
2450 : }
2451 : else { ... }
2452 : in which case we need not go looking to the else block.
2453 : (goto is not allowed in a constexpr function.) */
2454 0 : if (*jump_target == orig_jump)
2455 : {
2456 0 : arg = ((TREE_CODE (t) != IF_STMT || TREE_OPERAND (t, 2))
2457 0 : ? TREE_OPERAND (t, 2)
2458 : : void_node);
2459 0 : r = eval_constant_expression (ctx, arg, lval, non_constant_p,
2460 : overflow_p, jump_target);
2461 : }
2462 : break;
2463 : }
2464 16 : r = eval_conditional_expression (ctx, t, lval, non_constant_p, overflow_p,
2465 : jump_target);
2466 16 : break;
2467 :
2468 0 : case VEC_COND_EXPR:
2469 0 : r = eval_vector_conditional_expression (ctx, t, non_constant_p,
2470 : overflow_p, jump_target);
2471 0 : break;
2472 :
2473 0 : case TRY_CATCH_EXPR:
2474 0 : if (TREE_OPERAND (t, 0) == NULL_TREE)
2475 : {
2476 0 : r = void_node;
2477 0 : break;
2478 : }
2479 0 : r = eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval,
2480 : non_constant_p, overflow_p, jump_target);
2481 0 : break;
2482 :
2483 0 : case CLEANUP_POINT_EXPR:
2484 0 : {
2485 0 : auto_vec<tree, 2> cleanups;
2486 0 : vec<tree> *prev_cleanups = ctx->global->cleanups;
2487 0 : ctx->global->cleanups = &cleanups;
2488 0 : r = eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval,
2489 : non_constant_p, overflow_p, jump_target);
2490 0 : ctx->global->cleanups = prev_cleanups;
2491 0 : unsigned int i;
2492 0 : tree cleanup;
2493 : /* Evaluate the cleanups. */
2494 0 : FOR_EACH_VEC_ELT_REVERSE (cleanups, i, cleanup)
2495 0 : eval_constant_expression (ctx, cleanup, false, non_constant_p,
2496 : overflow_p, jump_target);
2497 0 : }
2498 0 : break;
2499 :
2500 0 : case TRY_FINALLY_EXPR:
2501 0 : r = eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval,
2502 : non_constant_p, overflow_p, jump_target);
2503 0 : if (!*non_constant_p)
2504 : /* Also evaluate the cleanup. */
2505 0 : eval_constant_expression (ctx, TREE_OPERAND (t, 1), true,
2506 : non_constant_p, overflow_p, jump_target);
2507 : break;
2508 :
2509 62 : case CONSTRUCTOR:
2510 62 : if (TREE_CONSTANT (t) && reduced_constant_expression_p (t))
2511 : {
2512 : /* Don't re-process a constant CONSTRUCTOR, but do fold it to
2513 : VECTOR_CST if applicable. */
2514 62 : verify_constructor_flags (t);
2515 62 : if (TREE_CONSTANT (t))
2516 62 : return fold (t);
2517 : }
2518 0 : r = eval_bare_aggregate (ctx, t, lval, non_constant_p, overflow_p,
2519 : jump_target);
2520 0 : break;
2521 :
2522 : /* FALLTHROUGH. */
2523 8 : case NOP_EXPR:
2524 8 : case CONVERT_EXPR:
2525 8 : case VIEW_CONVERT_EXPR:
2526 8 : {
2527 8 : tree oldop = TREE_OPERAND (t, 0);
2528 :
2529 8 : tree op = eval_constant_expression (ctx, oldop, lval, non_constant_p,
2530 : overflow_p, jump_target);
2531 8 : if (*non_constant_p)
2532 : return t;
2533 7 : tree type = TREE_TYPE (t);
2534 :
2535 7 : if (VOID_TYPE_P (type))
2536 0 : return void_node;
2537 :
2538 0 : if (TREE_CODE (t) == CONVERT_EXPR && ARITHMETIC_TYPE_P (type)
2539 7 : && INDIRECT_TYPE_P (TREE_TYPE (op)) && ctx->manifestly_const_eval)
2540 : {
2541 0 : if (!ctx->quiet)
2542 0 : error_at (loc,
2543 : "conversion from pointer type %qT to arithmetic type "
2544 : "%qT in a constant expression",
2545 0 : TREE_TYPE (op), type);
2546 0 : *non_constant_p = true;
2547 0 : return t;
2548 : }
2549 :
2550 0 : if (TYPE_PTROB_P (type) && TYPE_PTR_P (TREE_TYPE (op))
2551 7 : && VOID_TYPE_P (TREE_TYPE (TREE_TYPE (op))))
2552 : {
2553 : /* Likewise, don't error when casting from void* when OP is
2554 : &heap uninit and similar. */
2555 0 : tree sop = tree_strip_nop_conversions (op);
2556 0 : if (TREE_CODE (sop) == ADDR_EXPR && VAR_P (TREE_OPERAND (sop, 0))
2557 0 : && DECL_ARTIFICIAL (TREE_OPERAND (sop, 0)))
2558 : /* OK */;
2559 : else
2560 : {
2561 0 : if (!ctx->quiet)
2562 0 : error_at (loc, "cast from %qT is not allowed",
2563 0 : TREE_TYPE (op));
2564 0 : *non_constant_p = true;
2565 0 : return t;
2566 : }
2567 : }
2568 :
2569 7 : if (INDIRECT_TYPE_P (type) && TREE_CODE (op) == INTEGER_CST)
2570 : {
2571 0 : if (integer_zerop (op))
2572 : {
2573 0 : if (TYPE_REF_P (type))
2574 : {
2575 0 : if (!ctx->quiet)
2576 0 : error_at (loc, "dereferencing a null pointer");
2577 0 : *non_constant_p = true;
2578 0 : return t;
2579 : }
2580 : }
2581 : else
2582 : {
2583 : /* This detects for example:
2584 : reinterpret_cast<void*>(sizeof 0)
2585 : */
2586 0 : if (!ctx->quiet)
2587 0 : error_at (loc,
2588 : "%<reinterpret_cast<%T>(%E)%> is not "
2589 : "a constant expression",
2590 : type, op);
2591 0 : *non_constant_p = true;
2592 0 : return t;
2593 : }
2594 : }
2595 :
2596 0 : if (INDIRECT_TYPE_P (type) && TREE_CODE (op) == NOP_EXPR
2597 0 : && TREE_TYPE (op) == ptr_type_node
2598 0 : && TREE_CODE (TREE_OPERAND (op, 0)) == ADDR_EXPR
2599 0 : && VAR_P (TREE_OPERAND (TREE_OPERAND (op, 0), 0))
2600 7 : && (DECL_NAME (TREE_OPERAND (TREE_OPERAND (op, 0), 0))
2601 0 : == heap_uninit_identifier
2602 0 : || DECL_NAME (TREE_OPERAND (TREE_OPERAND (op, 0), 0))
2603 0 : == heap_vec_uninit_identifier))
2604 : {
2605 0 : tree var = TREE_OPERAND (TREE_OPERAND (op, 0), 0);
2606 0 : tree var_size = TYPE_SIZE_UNIT (TREE_TYPE (var));
2607 0 : tree elt_type = TREE_TYPE (type);
2608 0 : tree cookie_size = NULL_TREE;
2609 0 : if (TREE_CODE (elt_type) == RECORD_TYPE
2610 0 : && TYPE_NAME (elt_type) == heap_identifier)
2611 : {
2612 0 : tree fld1 = TYPE_FIELDS (elt_type);
2613 0 : tree fld2 = DECL_CHAIN (fld1);
2614 0 : elt_type = TREE_TYPE (TREE_TYPE (fld2));
2615 0 : cookie_size = TYPE_SIZE_UNIT (TREE_TYPE (fld1));
2616 : }
2617 0 : DECL_NAME (var) = (DECL_NAME (var) == heap_uninit_identifier
2618 0 : ? heap_identifier
2619 : : heap_vec_identifier);
2620 0 : TREE_TYPE (var)
2621 0 : = build_new_constexpr_heap_type (elt_type, cookie_size, var_size);
2622 0 : TREE_TYPE (TREE_OPERAND (op, 0))
2623 0 : = build_pointer_type (TREE_TYPE (var));
2624 : }
2625 :
2626 7 : if (op == oldop)
2627 : /* We didn't fold at the top so we could check for ptr-int
2628 : conversion. */
2629 0 : return fold (t);
2630 :
2631 7 : tree sop;
2632 :
2633 : /* Handle an array's bounds having been deduced after we built
2634 : the wrapping expression. */
2635 7 : if (same_type_ignoring_tlq_and_bounds_p (type, TREE_TYPE (op)))
2636 7 : r = op;
2637 0 : else if (sop = tree_strip_nop_conversions (op),
2638 : sop != op
2639 0 : && (same_type_ignoring_tlq_and_bounds_p (type,
2640 0 : TREE_TYPE (sop))))
2641 0 : r = sop;
2642 : else
2643 0 : r = fold_build1 (tcode, type, op);
2644 :
2645 : /* Conversion of an out-of-range value has implementation-defined
2646 : behavior; the language considers it different from arithmetic
2647 : overflow, which is undefined. */
2648 7 : if (TREE_OVERFLOW_P (r) && !TREE_OVERFLOW_P (op))
2649 0 : TREE_OVERFLOW (r) = false;
2650 : }
2651 : break;
2652 :
2653 0 : case PLACEHOLDER_EXPR:
2654 : /* Use of the value or address of the current object. */
2655 0 : if (tree ctor = lookup_placeholder (ctx, lval, TREE_TYPE (t)))
2656 : {
2657 0 : if (TREE_CODE (ctor) == CONSTRUCTOR)
2658 : return ctor;
2659 : else
2660 0 : return eval_constant_expression (ctx, ctor, lval, non_constant_p,
2661 0 : overflow_p, jump_target);
2662 : }
2663 : /* A placeholder without a referent. We can get here when
2664 : checking whether NSDMIs are noexcept, or in massage_init_elt;
2665 : just say it's non-constant for now. */
2666 0 : gcc_assert (ctx->quiet);
2667 0 : *non_constant_p = true;
2668 0 : break;
2669 :
2670 0 : case ANNOTATE_EXPR:
2671 0 : r = eval_constant_expression (ctx, TREE_OPERAND (t, 0), lval,
2672 : non_constant_p, overflow_p, jump_target);
2673 0 : break;
2674 :
2675 0 : case ASM_EXPR:
2676 0 : if (!ctx->quiet)
2677 0 : inline_asm_in_constexpr_error (loc);
2678 0 : *non_constant_p = true;
2679 0 : return t;
2680 :
2681 : default:
2682 : break;
2683 : }
2684 :
2685 533878 : return r;
2686 : }
2687 :
2688 : /* Complain about a const object OBJ being modified in a constant expression.
2689 : EXPR is the MODIFY_EXPR expression performing the modification. */
2690 :
2691 : static void
2692 0 : modifying_const_object_error (tree expr, tree obj)
2693 : {
2694 0 : location_t loc = EXPR_LOCATION (expr);
2695 0 : auto_diagnostic_group d;
2696 0 : error_at (loc,
2697 : "modifying a const object %qE is not allowed in "
2698 : "a constant expression",
2699 0 : TREE_OPERAND (expr, 0));
2700 0 : inform (location_of (obj), "originally declared %<const%> here");
2701 0 : }
2702 :
2703 : /* Return true iff DECL is an empty field, either for an empty base or a
2704 : [[no_unique_address]] data member. */
2705 :
2706 : bool
2707 1 : is_empty_field (tree decl)
2708 : {
2709 1 : if (!decl || TREE_CODE (decl) != FIELD_DECL)
2710 : return false;
2711 :
2712 1 : bool r = is_empty_class (TREE_TYPE (decl));
2713 :
2714 : /* Empty fields should have size zero. */
2715 1 : gcc_checking_assert (!r || integer_zerop (DECL_SIZE (decl)));
2716 :
2717 : return r;
2718 : }
2719 :
2720 : static tree
2721 2120 : eval_store_expression (const constexpr_ctx *ctx, tree t, bool lval,
2722 : bool *non_constant_p, bool *overflow_p,
2723 : tree *jump_target)
2724 : {
2725 2120 : constexpr_ctx new_ctx = *ctx;
2726 :
2727 2120 : tree init = TREE_OPERAND (t, 1);
2728 2120 : if (TREE_CLOBBER_P (init))
2729 : /* Just ignore clobbers. */
2730 0 : return void_node;
2731 :
2732 : /* First we figure out where we're storing to. */
2733 2120 : tree target = TREE_OPERAND (t, 0);
2734 :
2735 2120 : tree type = TREE_TYPE (target);
2736 2120 : bool preeval = SCALAR_TYPE_P (type) || TREE_CODE (t) == MODIFY_EXPR;
2737 : if (preeval)
2738 : {
2739 : /* Evaluate the value to be stored without knowing what object it will be
2740 : stored in, so that any side-effects happen first. */
2741 2120 : if (!SCALAR_TYPE_P (type))
2742 64 : new_ctx.ctor = new_ctx.object = NULL_TREE;
2743 2120 : init = eval_constant_expression (&new_ctx, init, false, non_constant_p,
2744 : overflow_p, jump_target);
2745 2120 : if (*non_constant_p)
2746 : return t;
2747 : }
2748 :
2749 2116 : bool evaluated = false;
2750 2116 : if (lval)
2751 : {
2752 : /* If we want to return a reference to the target, we need to evaluate it
2753 : as a whole; otherwise, only evaluate the innermost piece to avoid
2754 : building up unnecessary *_REFs. */
2755 0 : target = eval_constant_expression (ctx, target, true, non_constant_p,
2756 : overflow_p, jump_target);
2757 0 : evaluated = true;
2758 0 : if (*non_constant_p)
2759 : return t;
2760 : }
2761 :
2762 : /* Find the underlying variable. */
2763 2116 : releasing_vec refs;
2764 2116 : tree object = NULL_TREE;
2765 : /* If we're modifying a const object, save it. */
2766 2116 : tree const_object_being_modified = NULL_TREE;
2767 : // bool mutable_p = false;
2768 6350 : for (tree probe = target; object == NULL_TREE;)
2769 : {
2770 4234 : switch (TREE_CODE (probe))
2771 : {
2772 2 : case BIT_FIELD_REF:
2773 2 : case COMPONENT_REF:
2774 2 : case ARRAY_REF:
2775 2 : {
2776 2 : tree ob = TREE_OPERAND (probe, 0);
2777 2 : tree elt = TREE_OPERAND (probe, 1);
2778 2 : if (TREE_CODE (elt) == FIELD_DECL /*&& DECL_MUTABLE_P (elt)*/)
2779 : {
2780 : // mutable_p = true;
2781 : }
2782 2 : if (TREE_CODE (probe) == ARRAY_REF)
2783 : {
2784 1 : elt = eval_and_check_array_index (ctx, probe, false,
2785 : non_constant_p, overflow_p,
2786 : jump_target);
2787 1 : if (*non_constant_p)
2788 0 : return t;
2789 : }
2790 : /* We don't check modifying_const_object_p for ARRAY_REFs. Given
2791 : "int a[10]", an ARRAY_REF "a[2]" can be "const int", even though
2792 : the array isn't const. Instead, check "a" in the next iteration;
2793 : that will detect modifying "const int a[10]". */
2794 : // else if (evaluated
2795 : // && modifying_const_object_p (TREE_CODE (t), probe,
2796 : // mutable_p)
2797 : // && const_object_being_modified == NULL_TREE)
2798 : // const_object_being_modified = probe;
2799 2 : vec_safe_push (refs, elt);
2800 2 : vec_safe_push (refs, TREE_TYPE (probe));
2801 2 : probe = ob;
2802 : }
2803 2 : break;
2804 :
2805 4232 : default:
2806 4232 : if (evaluated)
2807 2116 : object = probe;
2808 : else
2809 : {
2810 2116 : probe
2811 2116 : = eval_constant_expression (ctx, probe, true, non_constant_p,
2812 : overflow_p, jump_target);
2813 2116 : evaluated = true;
2814 2116 : if (*non_constant_p)
2815 : return t;
2816 : }
2817 : break;
2818 : }
2819 : }
2820 :
2821 : // if (modifying_const_object_p (TREE_CODE (t), object, mutable_p)
2822 : // && const_object_being_modified == NULL_TREE)
2823 : // const_object_being_modified = object;
2824 :
2825 : /* And then find/build up our initializer for the path to the subobject
2826 : we're initializing. */
2827 2116 : tree *valp;
2828 2116 : if (DECL_P (object))
2829 2116 : valp = ctx->global->values.get (object);
2830 : else
2831 : valp = NULL;
2832 2116 : if (!valp)
2833 : {
2834 : /* A constant-expression cannot modify objects from outside the
2835 : constant-expression. */
2836 0 : if (!ctx->quiet)
2837 0 : error ("modification of %qE is not a constant expression", object);
2838 0 : *non_constant_p = true;
2839 0 : return t;
2840 : }
2841 2116 : type = TREE_TYPE (object);
2842 2116 : bool no_zero_init = true;
2843 :
2844 4232 : releasing_vec ctors, indexes;
2845 4232 : auto_vec<int> index_pos_hints;
2846 2116 : bool activated_union_member_p = false;
2847 2118 : while (!refs->is_empty ())
2848 : {
2849 2 : if (*valp == NULL_TREE)
2850 : {
2851 0 : *valp = build_constructor (type, NULL);
2852 0 : CONSTRUCTOR_NO_CLEARING (*valp) = no_zero_init;
2853 : }
2854 2 : else if (TREE_CODE (*valp) == STRING_CST)
2855 : {
2856 : /* An array was initialized with a string constant, and now
2857 : we're writing into one of its elements. Explode the
2858 : single initialization into a set of element
2859 : initializations. */
2860 0 : gcc_assert (TREE_CODE (type) == ARRAY_TYPE);
2861 :
2862 0 : tree string = *valp;
2863 0 : tree elt_type = TREE_TYPE (type);
2864 0 : unsigned chars_per_elt
2865 0 : = (TYPE_PRECISION (elt_type) / TYPE_PRECISION (char_type_node));
2866 0 : unsigned num_elts = TREE_STRING_LENGTH (string) / chars_per_elt;
2867 0 : tree ary_ctor = build_constructor (type, NULL);
2868 :
2869 0 : vec_safe_reserve (CONSTRUCTOR_ELTS (ary_ctor), num_elts);
2870 0 : for (unsigned ix = 0; ix != num_elts; ix++)
2871 : {
2872 0 : constructor_elt elt
2873 0 : = {build_int_cst (size_type_node, ix),
2874 0 : extract_string_elt (string, chars_per_elt, ix)};
2875 0 : CONSTRUCTOR_ELTS (ary_ctor)->quick_push (elt);
2876 : }
2877 :
2878 0 : *valp = ary_ctor;
2879 : }
2880 :
2881 : /* If the value of object is already zero-initialized, any new ctors for
2882 : subobjects will also be zero-initialized. */
2883 2 : no_zero_init = CONSTRUCTOR_NO_CLEARING (*valp);
2884 :
2885 2 : enum tree_code code = TREE_CODE (type);
2886 2 : type = refs->pop ();
2887 2 : tree index = refs->pop ();
2888 :
2889 2 : if (code == RECORD_TYPE && is_empty_field (index))
2890 : /* Don't build a sub-CONSTRUCTOR for an empty base or field, as they
2891 : have no data and might have an offset lower than previously declared
2892 : fields, which confuses the middle-end. The code below will notice
2893 : that we don't have a CONSTRUCTOR for our inner target and just
2894 : return init. */
2895 : break;
2896 :
2897 0 : if (code == UNION_TYPE && CONSTRUCTOR_NELTS (*valp)
2898 2 : && CONSTRUCTOR_ELT (*valp, 0)->index != index)
2899 : {
2900 0 : if (TREE_CODE (t) == MODIFY_EXPR && CONSTRUCTOR_NO_CLEARING (*valp))
2901 : {
2902 : /* Diagnose changing the active union member while the union
2903 : is in the process of being initialized. */
2904 0 : if (!ctx->quiet)
2905 0 : error_at (EXPR_LOCATION (t),
2906 : "change of the active member of a union "
2907 : "from %qD to %qD during initialization",
2908 0 : CONSTRUCTOR_ELT (*valp, 0)->index, index);
2909 0 : *non_constant_p = true;
2910 : }
2911 : no_zero_init = true;
2912 : }
2913 :
2914 2 : vec_safe_push (ctors, *valp);
2915 2 : vec_safe_push (indexes, index);
2916 :
2917 2 : constructor_elt *cep = get_or_insert_ctor_field (*valp, index);
2918 2 : index_pos_hints.safe_push (cep - CONSTRUCTOR_ELTS (*valp)->begin ());
2919 :
2920 2 : if (code == UNION_TYPE)
2921 0 : activated_union_member_p = true;
2922 :
2923 2 : valp = &cep->value;
2924 : }
2925 :
2926 : /* Detect modifying a constant object in constexpr evaluation.
2927 : We have found a const object that is being modified. Figure out
2928 : if we need to issue an error. Consider
2929 :
2930 : struct A {
2931 : int n;
2932 : constexpr A() : n(1) { n = 2; } // #1
2933 : };
2934 : struct B {
2935 : const A a;
2936 : constexpr B() { a.n = 3; } // #2
2937 : };
2938 : constexpr B b{};
2939 :
2940 : #1 is OK, since we're modifying an object under construction, but
2941 : #2 is wrong, since "a" is const and has been fully constructed.
2942 : To track it, we use the TREE_READONLY bit in the object's CONSTRUCTOR
2943 : which means that the object is read-only. For the example above, the
2944 : *ctors stack at the point of #2 will look like:
2945 :
2946 : ctors[0] = {.a={.n=2}} TREE_READONLY = 0
2947 : ctors[1] = {.n=2} TREE_READONLY = 1
2948 :
2949 : and we're modifying "b.a", so we search the stack and see if the
2950 : constructor for "b.a" has already run. */
2951 2116 : if (const_object_being_modified)
2952 : {
2953 : bool fail = false;
2954 : tree const_objtype
2955 : = strip_array_types (TREE_TYPE (const_object_being_modified));
2956 : if (!CLASS_TYPE_P (const_objtype))
2957 : fail = true;
2958 : else
2959 : {
2960 : /* [class.ctor]p5 "A constructor can be invoked for a const,
2961 : volatile, or const volatile object. const and volatile
2962 : semantics are not applied on an object under construction.
2963 : They come into effect when the constructor for the most
2964 : derived object ends." */
2965 : for (tree elt : *ctors)
2966 : if (same_type_ignoring_top_level_qualifiers_p (
2967 : TREE_TYPE (const_object_being_modified), TREE_TYPE (elt)))
2968 : {
2969 : fail = TREE_READONLY (elt);
2970 : break;
2971 : }
2972 : }
2973 : if (fail)
2974 : {
2975 : if (!ctx->quiet)
2976 : modifying_const_object_error (t, const_object_being_modified);
2977 : *non_constant_p = true;
2978 : return t;
2979 : }
2980 : }
2981 :
2982 2116 : if (!preeval)
2983 : {
2984 : /* We're handling an INIT_EXPR of class type, so the value of the
2985 : initializer can depend on the object it's initializing. */
2986 :
2987 : /* Create a new CONSTRUCTOR in case evaluation of the initializer
2988 : wants to modify it. */
2989 0 : if (*valp == NULL_TREE)
2990 : {
2991 0 : *valp = build_constructor (type, NULL);
2992 0 : CONSTRUCTOR_NO_CLEARING (*valp) = no_zero_init;
2993 : }
2994 0 : new_ctx.ctor = *valp;
2995 0 : new_ctx.object = target;
2996 : /* Avoid temporary materialization when initializing from a TARGET_EXPR.
2997 : We don't need to mess with AGGR_EXPR_SLOT/VEC_INIT_EXPR_SLOT because
2998 : expansion of those trees uses ctx instead. */
2999 0 : if (TREE_CODE (init) == TARGET_EXPR)
3000 0 : if (tree tinit = TARGET_EXPR_INITIAL (init))
3001 0 : init = tinit;
3002 0 : init = eval_constant_expression (&new_ctx, init, false, non_constant_p,
3003 : overflow_p, jump_target);
3004 : /* The hash table might have moved since the get earlier, and the
3005 : initializer might have mutated the underlying CONSTRUCTORs, so we must
3006 : recompute VALP. */
3007 0 : valp = ctx->global->values.get (object);
3008 0 : for (unsigned i = 0; i < vec_safe_length (indexes); i++)
3009 : {
3010 0 : constructor_elt *cep
3011 0 : = get_or_insert_ctor_field (*valp, indexes[i], index_pos_hints[i]);
3012 0 : valp = &cep->value;
3013 : }
3014 : }
3015 :
3016 2116 : if (*non_constant_p)
3017 : return t;
3018 :
3019 : /* Don't share a CONSTRUCTOR that might be changed later. */
3020 2116 : init = unshare_constructor (init);
3021 2116 : if (init == NULL_TREE)
3022 : return t;
3023 :
3024 2116 : if (*valp && TREE_CODE (*valp) == CONSTRUCTOR
3025 1 : && TREE_CODE (init) == CONSTRUCTOR)
3026 : {
3027 : /* An outer ctx->ctor might be pointing to *valp, so replace
3028 : its contents. */
3029 1 : if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (init),
3030 1 : TREE_TYPE (*valp)))
3031 : {
3032 : /* For initialization of an empty base, the original target will be
3033 : *(base*)this, evaluation of which resolves to the object
3034 : argument, which has the derived type rather than the base type. In
3035 : this situation, just evaluate the initializer and return, since
3036 : there's no actual data to store. */
3037 0 : gcc_assert (is_empty_class (TREE_TYPE (init)));
3038 0 : return lval ? target : init;
3039 : }
3040 1 : CONSTRUCTOR_ELTS (*valp) = CONSTRUCTOR_ELTS (init);
3041 1 : TREE_CONSTANT (*valp) = TREE_CONSTANT (init);
3042 1 : TREE_SIDE_EFFECTS (*valp) = TREE_SIDE_EFFECTS (init);
3043 1 : CONSTRUCTOR_NO_CLEARING (*valp) = CONSTRUCTOR_NO_CLEARING (init);
3044 : }
3045 : // else if (TREE_CODE (init) == CONSTRUCTOR
3046 : // && !same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (init),
3047 : // type))
3048 : // {
3049 : // /* See above on initialization of empty bases. */
3050 : // // gcc_assert (is_empty_class (TREE_TYPE (init)) && !lval);
3051 : // return init;
3052 : // }
3053 : else
3054 2115 : *valp = init;
3055 :
3056 : /* After initialization, 'const' semantics apply to the value of the
3057 : object. Make a note of this fact by marking the CONSTRUCTOR
3058 : TREE_READONLY. */
3059 0 : if (TREE_CODE (t) == INIT_EXPR && TREE_CODE (*valp) == CONSTRUCTOR
3060 2116 : && TYPE_READONLY (type))
3061 : {
3062 : // this vs self? can rust's self be anything other than self or &self in
3063 : // constexpr mode? if (INDIRECT_REF_P (target)
3064 : // && (is_this_parameter (
3065 : // tree_strip_nop_conversions (TREE_OPERAND (target, 0)))))
3066 : /* We've just initialized '*this' (perhaps via the target
3067 : constructor of a delegating constructor). Leave it up to the
3068 : caller that set 'this' to set TREE_READONLY appropriately. */
3069 : // gcc_checking_assert (
3070 : // same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (target),
3071 : // type));
3072 : // else
3073 : // TREE_READONLY (*valp) = true;
3074 : }
3075 :
3076 : /* Update TREE_CONSTANT and TREE_SIDE_EFFECTS on enclosing
3077 : CONSTRUCTORs, if any. */
3078 2116 : bool c = TREE_CONSTANT (init);
3079 2116 : bool s = TREE_SIDE_EFFECTS (init);
3080 2116 : if (!c || s || activated_union_member_p)
3081 1 : for (tree elt : *ctors)
3082 : {
3083 0 : if (!c)
3084 0 : TREE_CONSTANT (elt) = false;
3085 0 : if (s)
3086 0 : TREE_SIDE_EFFECTS (elt) = true;
3087 : /* Clear CONSTRUCTOR_NO_CLEARING since we've activated a member of
3088 : this union. */
3089 0 : if (TREE_CODE (TREE_TYPE (elt)) == UNION_TYPE)
3090 0 : CONSTRUCTOR_NO_CLEARING (elt) = false;
3091 : }
3092 :
3093 2116 : if (*non_constant_p)
3094 : return t;
3095 2116 : else if (lval)
3096 : return target;
3097 : else
3098 2116 : return init;
3099 2116 : }
3100 :
3101 : /* Subroutine of cxx_eval_constant_expression.
3102 : Like cxx_eval_unary_expression, except for binary expressions. */
3103 : static tree
3104 45 : eval_binary_expression (const constexpr_ctx *ctx, tree t, bool lval,
3105 : bool *non_constant_p, bool *overflow_p,
3106 : tree *jump_target)
3107 : {
3108 45 : tree r = NULL_TREE;
3109 45 : tree orig_lhs = TREE_OPERAND (t, 0);
3110 45 : tree orig_rhs = TREE_OPERAND (t, 1);
3111 45 : tree lhs, rhs;
3112 45 : lhs = eval_constant_expression (ctx, orig_lhs, lval, non_constant_p,
3113 : overflow_p, jump_target);
3114 : /* Don't VERIFY_CONSTANT here, it's unnecessary and will break pointer
3115 : subtraction. */
3116 45 : if (*non_constant_p)
3117 : return t;
3118 44 : if (*jump_target)
3119 : return NULL_TREE;
3120 :
3121 44 : rhs = eval_constant_expression (ctx, orig_rhs, lval, non_constant_p,
3122 : overflow_p, jump_target);
3123 44 : if (*non_constant_p)
3124 : return t;
3125 44 : if (*jump_target)
3126 : return NULL_TREE;
3127 :
3128 44 : location_t loc = EXPR_LOCATION (t);
3129 44 : enum tree_code code = TREE_CODE (t);
3130 44 : tree type = TREE_TYPE (t);
3131 :
3132 44 : if (code == EQ_EXPR || code == NE_EXPR)
3133 : {
3134 15 : bool is_code_eq = (code == EQ_EXPR);
3135 :
3136 15 : if (TREE_CODE (lhs) == PTRMEM_CST && TREE_CODE (rhs) == PTRMEM_CST)
3137 : {
3138 0 : tree lmem = PTRMEM_CST_MEMBER (lhs);
3139 0 : tree rmem = PTRMEM_CST_MEMBER (rhs);
3140 0 : bool eq = false;
3141 0 : if (TREE_CODE (lmem) == TREE_CODE (rmem)
3142 0 : && TREE_CODE (lmem) == FIELD_DECL
3143 0 : && TREE_CODE (DECL_CONTEXT (lmem)) == UNION_TYPE
3144 0 : && same_type_p (DECL_CONTEXT (lmem), DECL_CONTEXT (rmem)))
3145 : /* If both refer to (possibly different) members of the same union
3146 : (12.3), they compare equal. */
3147 : eq = true;
3148 : // else
3149 : // eq = cp_tree_equal (lhs, rhs);
3150 0 : r = constant_boolean_node (eq == is_code_eq, type);
3151 0 : }
3152 15 : else if ((TREE_CODE (lhs) == PTRMEM_CST || TREE_CODE (rhs) == PTRMEM_CST)
3153 15 : && (null_member_pointer_value_p (lhs)
3154 0 : || null_member_pointer_value_p (rhs)))
3155 0 : r = constant_boolean_node (!is_code_eq, type);
3156 : }
3157 44 : if (r == NULL_TREE && TREE_CODE_CLASS (code) == tcc_comparison
3158 15 : && POINTER_TYPE_P (TREE_TYPE (lhs)))
3159 : {
3160 0 : if (tree lhso = maybe_fold_addr_pointer_plus (lhs))
3161 0 : lhs = fold_convert (TREE_TYPE (lhs), lhso);
3162 0 : if (tree rhso = maybe_fold_addr_pointer_plus (rhs))
3163 0 : rhs = fold_convert (TREE_TYPE (rhs), rhso);
3164 : }
3165 0 : if (code == POINTER_PLUS_EXPR && !*non_constant_p && integer_zerop (lhs)
3166 44 : && !integer_zerop (rhs))
3167 : {
3168 0 : if (!ctx->quiet)
3169 0 : error ("arithmetic involving a null pointer in %qE", lhs);
3170 0 : *non_constant_p = true;
3171 0 : return t;
3172 : }
3173 44 : else if (code == POINTER_PLUS_EXPR)
3174 : {
3175 0 : r = fold_pointer_plus_expression (ctx, t, lhs, rhs, non_constant_p,
3176 : overflow_p, jump_target);
3177 0 : if (*jump_target)
3178 : return NULL_TREE;
3179 : }
3180 :
3181 44 : if (r == NULL_TREE)
3182 : {
3183 44 : r = fold_binary_loc (loc, code, type, lhs, rhs);
3184 : }
3185 :
3186 2 : if (r == NULL_TREE && (code == LSHIFT_EXPR || code == RSHIFT_EXPR)
3187 0 : && TREE_CODE (lhs) == INTEGER_CST && TREE_CODE (rhs) == INTEGER_CST
3188 46 : && wi::neg_p (wi::to_wide (rhs)))
3189 : {
3190 : /* For diagnostics and -fpermissive emulate previous behavior of
3191 : handling shifts by negative amount. */
3192 0 : tree nrhs = const_unop (NEGATE_EXPR, TREE_TYPE (rhs), rhs);
3193 0 : if (nrhs)
3194 0 : r = fold_binary_loc (loc,
3195 : code == LSHIFT_EXPR ? RSHIFT_EXPR : LSHIFT_EXPR,
3196 : type, lhs, nrhs);
3197 : }
3198 :
3199 44 : if (r == NULL_TREE)
3200 : {
3201 2 : if (lhs == orig_lhs && rhs == orig_rhs)
3202 : r = t;
3203 : else
3204 0 : r = build2_loc (loc, code, type, lhs, rhs);
3205 : }
3206 42 : else if (eval_check_shift_p (loc, ctx, code, type, lhs, rhs))
3207 0 : *non_constant_p = true;
3208 : /* Don't VERIFY_CONSTANT if this might be dealing with a pointer to
3209 : a local array in a constexpr function. */
3210 44 : bool ptr = INDIRECT_TYPE_P (TREE_TYPE (lhs));
3211 44 : if (!ptr)
3212 44 : VERIFY_CONSTANT (r);
3213 : return r;
3214 : }
3215 :
3216 : /* Helper function of cxx_bind_parameters_in_call. Return non-NULL
3217 : if *TP is address of a static variable (or part of it) currently being
3218 : constructed or of a heap artificial variable. */
3219 :
3220 : static tree
3221 3 : addr_of_non_const_var (tree *tp, int *walk_subtrees, void *data)
3222 : {
3223 3 : if (TREE_CODE (*tp) == ADDR_EXPR)
3224 0 : if (tree var = get_base_address (TREE_OPERAND (*tp, 0)))
3225 0 : if (VAR_P (var) && TREE_STATIC (var))
3226 : {
3227 0 : if (DECL_NAME (var) == heap_uninit_identifier
3228 0 : || DECL_NAME (var) == heap_identifier
3229 0 : || DECL_NAME (var) == heap_vec_uninit_identifier
3230 0 : || DECL_NAME (var) == heap_vec_identifier)
3231 0 : return var;
3232 :
3233 0 : constexpr_global_ctx *global = (constexpr_global_ctx *) data;
3234 0 : if (global->values.get (var))
3235 : return var;
3236 : }
3237 3 : if (TYPE_P (*tp))
3238 0 : *walk_subtrees = false;
3239 : return NULL_TREE;
3240 : }
3241 :
3242 : /* Subroutine of cxx_eval_call_expression.
3243 : We are processing a call expression (either CALL_EXPR or
3244 : AGGR_INIT_EXPR) in the context of CTX. Evaluate
3245 : all arguments and bind their values to correspondings
3246 : parameters, making up the NEW_CALL context. */
3247 :
3248 : static tree
3249 2103 : rs_bind_parameters_in_call (const constexpr_ctx *ctx, tree t, tree fun,
3250 : bool *non_constant_p, bool *overflow_p,
3251 : bool *non_constant_args, tree *jump_target)
3252 : {
3253 2103 : const int nargs = call_expr_nargs (t);
3254 2103 : tree parms = DECL_ARGUMENTS (fun);
3255 2103 : int i;
3256 : /* We don't record ellipsis args below. */
3257 2103 : int nparms = list_length (parms);
3258 2103 : int nbinds = nargs < nparms ? nargs : nparms;
3259 2103 : tree binds = make_tree_vec (nbinds);
3260 2106 : for (i = 0; i < nargs; ++i)
3261 : {
3262 3 : tree x, arg;
3263 3 : tree type = parms ? TREE_TYPE (parms) : void_type_node;
3264 3 : if (parms && DECL_BY_REFERENCE (parms))
3265 0 : type = TREE_TYPE (type);
3266 3 : x = CALL_EXPR_ARG (t, i);
3267 :
3268 3 : if (TREE_ADDRESSABLE (type))
3269 : /* Undo convert_for_arg_passing work here. */
3270 0 : x = convert_from_reference (x);
3271 : /* Normally we would strip a TARGET_EXPR in an initialization context
3272 : such as this, but here we do the elision differently: we keep the
3273 : TARGET_EXPR, and use its CONSTRUCTOR as the value of the parm. */
3274 3 : arg = eval_constant_expression (ctx, x, /*lval=*/false, non_constant_p,
3275 : overflow_p, jump_target);
3276 : /* Don't VERIFY_CONSTANT here. */
3277 3 : if (*non_constant_p && ctx->quiet)
3278 : break;
3279 : /* Just discard ellipsis args after checking their constantitude. */
3280 3 : if (!parms)
3281 0 : continue;
3282 :
3283 3 : if (!*non_constant_p)
3284 : {
3285 : /* Make sure the binding has the same type as the parm. But
3286 : only for constant args. */
3287 3 : if (!TYPE_REF_P (type))
3288 3 : arg = adjust_temp_type (type, arg);
3289 3 : if (!TREE_CONSTANT (arg))
3290 0 : *non_constant_args = true;
3291 3 : else if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
3292 : /* The destructor needs to see any modifications the callee makes
3293 : to the argument. */
3294 0 : *non_constant_args = true;
3295 : /* If arg is or contains address of a heap artificial variable or
3296 : of a static variable being constructed, avoid caching the
3297 : function call, as those variables might be modified by the
3298 : function, or might be modified by the callers in between
3299 : the cached function and just read by the function. */
3300 3 : else if (!*non_constant_args
3301 3 : && rs_walk_tree (&arg, addr_of_non_const_var, ctx->global,
3302 : NULL))
3303 0 : *non_constant_args = true;
3304 :
3305 : // /* For virtual calls, adjust the this argument, so that it is
3306 : // the object on which the method is called, rather than
3307 : // one of its bases. */
3308 : // if (i == 0 && DECL_VIRTUAL_P (fun))
3309 : // {
3310 : // tree addr = arg;
3311 : // STRIP_NOPS (addr);
3312 : // if (TREE_CODE (addr) == ADDR_EXPR)
3313 : // {
3314 : // tree obj = TREE_OPERAND (addr, 0);
3315 : // while (TREE_CODE (obj) == COMPONENT_REF
3316 : // && DECL_FIELD_IS_BASE (TREE_OPERAND (obj, 1))
3317 : // && !same_type_ignoring_top_level_qualifiers_p (
3318 : // TREE_TYPE (obj), DECL_CONTEXT (fun)))
3319 : // obj = TREE_OPERAND (obj, 0);
3320 : // if (obj != TREE_OPERAND (addr, 0))
3321 : // arg = build_fold_addr_expr_with_type (obj, TREE_TYPE
3322 : // (arg));
3323 : // }
3324 : // }
3325 3 : TREE_VEC_ELT (binds, i) = arg;
3326 : }
3327 3 : parms = TREE_CHAIN (parms);
3328 : }
3329 :
3330 2103 : return binds;
3331 : }
3332 :
3333 : // forked from gcc/cp/constexpr.cc cxx_eval_builtin_function_call
3334 :
3335 : /* Attempt to evaluate T which represents a call to a builtin function.
3336 : We assume here that all builtin functions evaluate to scalar types
3337 : represented by _CST nodes. */
3338 :
3339 : static tree
3340 0 : eval_builtin_function_call (const constexpr_ctx *ctx, tree t, tree fun,
3341 : bool lval, bool *non_constant_p, bool *overflow_p,
3342 : tree *jump_target)
3343 : {
3344 0 : const int nargs = call_expr_nargs (t);
3345 0 : tree *args = (tree *) alloca (nargs * sizeof (tree));
3346 0 : tree new_call;
3347 0 : int i;
3348 :
3349 : /* Don't fold __builtin_constant_p within a constexpr function. */
3350 0 : bool bi_const_p = DECL_IS_BUILTIN_CONSTANT_P (fun);
3351 :
3352 : /* If we aren't requiring a constant expression, defer __builtin_constant_p
3353 : in a constexpr function until we have values for the parameters. */
3354 0 : if (bi_const_p && !ctx->manifestly_const_eval && current_function_decl
3355 0 : && DECL_DECLARED_CONSTEXPR_P (current_function_decl))
3356 : {
3357 0 : *non_constant_p = true;
3358 0 : return t;
3359 : }
3360 :
3361 : /* For __builtin_is_constant_evaluated, defer it if not
3362 : ctx->manifestly_const_eval (as sometimes we try to constant evaluate
3363 : without manifestly_const_eval even expressions or parts thereof which
3364 : will later be manifestly const_eval evaluated), otherwise fold it to
3365 : true. */
3366 0 : if (fndecl_built_in_p (fun, CP_BUILT_IN_IS_CONSTANT_EVALUATED,
3367 : BUILT_IN_FRONTEND))
3368 : {
3369 0 : if (!ctx->manifestly_const_eval)
3370 : {
3371 0 : *non_constant_p = true;
3372 0 : return t;
3373 : }
3374 0 : return boolean_true_node;
3375 : }
3376 :
3377 0 : if (fndecl_built_in_p (fun, CP_BUILT_IN_SOURCE_LOCATION, BUILT_IN_FRONTEND))
3378 : {
3379 0 : temp_override<tree> ovr (current_function_decl);
3380 0 : if (ctx->call && ctx->call->fundef)
3381 0 : current_function_decl = ctx->call->fundef->decl;
3382 0 : return fold_builtin_source_location (EXPR_LOCATION (t));
3383 0 : }
3384 :
3385 0 : int strops = 0;
3386 0 : int strret = 0;
3387 0 : if (fndecl_built_in_p (fun, BUILT_IN_NORMAL))
3388 0 : switch (DECL_FUNCTION_CODE (fun))
3389 : {
3390 : case BUILT_IN_STRLEN:
3391 : case BUILT_IN_STRNLEN:
3392 0 : strops = 1;
3393 : break;
3394 0 : case BUILT_IN_MEMCHR:
3395 0 : case BUILT_IN_STRCHR:
3396 0 : case BUILT_IN_STRRCHR:
3397 0 : strops = 1;
3398 0 : strret = 1;
3399 0 : break;
3400 0 : case BUILT_IN_MEMCMP:
3401 0 : case BUILT_IN_STRCMP:
3402 0 : strops = 2;
3403 0 : break;
3404 0 : case BUILT_IN_STRSTR:
3405 0 : strops = 2;
3406 0 : strret = 1;
3407 0 : break;
3408 0 : case BUILT_IN_ASAN_POINTER_COMPARE:
3409 0 : case BUILT_IN_ASAN_POINTER_SUBTRACT:
3410 : /* These builtins shall be ignored during constant expression
3411 : evaluation. */
3412 0 : return void_node;
3413 : default:
3414 : break;
3415 : }
3416 :
3417 : /* Be permissive for arguments to built-ins; __builtin_constant_p should
3418 : return constant false for a non-constant argument. */
3419 0 : constexpr_ctx new_ctx = *ctx;
3420 0 : new_ctx.quiet = true;
3421 0 : for (i = 0; i < nargs; ++i)
3422 : {
3423 0 : tree arg = CALL_EXPR_ARG (t, i);
3424 0 : tree oarg = arg;
3425 :
3426 : /* To handle string built-ins we need to pass ADDR_EXPR<STRING_CST> since
3427 : expand_builtin doesn't know how to look in the values table. */
3428 0 : bool strop = i < strops;
3429 0 : if (strop)
3430 : {
3431 0 : STRIP_NOPS (arg);
3432 0 : if (TREE_CODE (arg) == ADDR_EXPR)
3433 0 : arg = TREE_OPERAND (arg, 0);
3434 : else
3435 : strop = false;
3436 : }
3437 :
3438 : /* If builtin_valid_in_constant_expr_p is true,
3439 : potential_constant_expression_1 has not recursed into the arguments
3440 : of the builtin, verify it here. */
3441 0 : if (!builtin_valid_in_constant_expr_p (fun)
3442 0 : || potential_constant_expression (arg))
3443 : {
3444 0 : bool dummy1 = false, dummy2 = false;
3445 0 : tree dummy_jump_target = NULL_TREE;
3446 0 : arg = eval_constant_expression (&new_ctx, arg, false, &dummy1,
3447 : &dummy2, &dummy_jump_target);
3448 : }
3449 :
3450 0 : if (bi_const_p)
3451 : /* For __builtin_constant_p, fold all expressions with constant values
3452 : even if they aren't C++ constant-expressions. */
3453 0 : arg = cp_fold_rvalue (arg);
3454 0 : else if (strop)
3455 : {
3456 0 : if (TREE_CODE (arg) == CONSTRUCTOR)
3457 0 : arg = braced_lists_to_strings (TREE_TYPE (arg), arg);
3458 0 : if (TREE_CODE (arg) == STRING_CST)
3459 0 : arg = build_address (arg);
3460 : else
3461 : arg = oarg;
3462 : }
3463 :
3464 0 : args[i] = arg;
3465 : }
3466 :
3467 0 : bool save_ffbcp = force_folding_builtin_constant_p;
3468 0 : force_folding_builtin_constant_p |= ctx->manifestly_const_eval;
3469 0 : tree save_cur_fn = current_function_decl;
3470 : /* Return name of ctx->call->fundef->decl for __builtin_FUNCTION (). */
3471 0 : if (fndecl_built_in_p (fun, BUILT_IN_FUNCTION) && ctx->call
3472 0 : && ctx->call->fundef)
3473 0 : current_function_decl = ctx->call->fundef->decl;
3474 0 : if (fndecl_built_in_p (fun,
3475 : CP_BUILT_IN_IS_POINTER_INTERCONVERTIBLE_WITH_CLASS,
3476 : BUILT_IN_FRONTEND))
3477 : {
3478 0 : location_t loc = EXPR_LOCATION (t);
3479 0 : if (nargs >= 1)
3480 0 : VERIFY_CONSTANT (args[0]);
3481 0 : new_call
3482 0 : = fold_builtin_is_pointer_inverconvertible_with_class (loc, nargs,
3483 : args);
3484 : }
3485 0 : else if (fndecl_built_in_p (fun, CP_BUILT_IN_IS_CORRESPONDING_MEMBER,
3486 : BUILT_IN_FRONTEND))
3487 : {
3488 0 : location_t loc = EXPR_LOCATION (t);
3489 0 : if (nargs >= 2)
3490 : {
3491 0 : VERIFY_CONSTANT (args[0]);
3492 0 : VERIFY_CONSTANT (args[1]);
3493 : }
3494 0 : new_call = fold_builtin_is_corresponding_member (loc, nargs, args);
3495 : }
3496 : else
3497 0 : new_call = fold_builtin_call_array (EXPR_LOCATION (t), TREE_TYPE (t),
3498 0 : CALL_EXPR_FN (t), nargs, args);
3499 0 : current_function_decl = save_cur_fn;
3500 0 : force_folding_builtin_constant_p = save_ffbcp;
3501 0 : if (new_call == NULL)
3502 : {
3503 0 : if (!*non_constant_p && !ctx->quiet)
3504 : {
3505 : /* Do not allow__builtin_unreachable in constexpr function.
3506 : The __builtin_unreachable call with BUILTINS_LOCATION
3507 : comes from cp_maybe_instrument_return. */
3508 0 : if (fndecl_built_in_p (fun, BUILT_IN_UNREACHABLE)
3509 0 : && EXPR_LOCATION (t) == BUILTINS_LOCATION)
3510 0 : error ("%<constexpr%> call flows off the end of the function");
3511 : else
3512 : {
3513 0 : new_call = build_call_array_loc (EXPR_LOCATION (t), TREE_TYPE (t),
3514 0 : CALL_EXPR_FN (t), nargs, args);
3515 0 : error ("%q+E is not a constant expression", new_call);
3516 : }
3517 : }
3518 0 : *non_constant_p = true;
3519 0 : return t;
3520 : }
3521 :
3522 0 : if (!potential_constant_expression (new_call))
3523 : {
3524 0 : if (!*non_constant_p && !ctx->quiet)
3525 0 : error ("%q+E is not a constant expression", new_call);
3526 0 : *non_constant_p = true;
3527 0 : return t;
3528 : }
3529 :
3530 0 : if (strret)
3531 : {
3532 : /* memchr returns a pointer into the first argument, but we replaced the
3533 : argument above with a STRING_CST; put it back it now. */
3534 0 : tree op = CALL_EXPR_ARG (t, strret - 1);
3535 0 : STRIP_NOPS (new_call);
3536 0 : if (TREE_CODE (new_call) == POINTER_PLUS_EXPR)
3537 0 : TREE_OPERAND (new_call, 0) = op;
3538 0 : else if (TREE_CODE (new_call) == ADDR_EXPR)
3539 0 : new_call = op;
3540 : }
3541 :
3542 0 : return eval_constant_expression (&new_ctx, new_call, lval, non_constant_p,
3543 0 : overflow_p, jump_target);
3544 : }
3545 :
3546 : // Subroutine of cxx_eval_constant_expression.
3547 : // Evaluate the call expression tree T in the context of OLD_CALL expression
3548 : // evaluation.
3549 : static tree
3550 2103 : eval_call_expression (const constexpr_ctx *ctx, tree t, bool lval,
3551 : bool *non_constant_p, bool *overflow_p, tree *jump_target)
3552 : {
3553 2103 : location_t loc = EXPR_LOCATION (t);
3554 2103 : tree fun = get_function_named_in_call (t);
3555 2103 : rust_constexpr_call new_call
3556 2103 : = {NULL, NULL, NULL, 0, ctx->manifestly_const_eval};
3557 2103 : int depth_ok;
3558 :
3559 2103 : if (fun == NULL_TREE)
3560 : {
3561 : // return cxx_eval_internal_function (ctx, t, lval,
3562 : // non_constant_p, overflow_p);
3563 0 : rust_unreachable ();
3564 : return error_mark_node;
3565 : }
3566 :
3567 2103 : if (TREE_CODE (fun) != FUNCTION_DECL)
3568 : {
3569 0 : if (!ctx->quiet && !*non_constant_p)
3570 0 : error_at (loc,
3571 : "expression %qE does not designate a %<constexpr%> "
3572 : "function",
3573 : fun);
3574 0 : *non_constant_p = true;
3575 0 : return t;
3576 : }
3577 :
3578 2103 : if (fndecl_built_in_p (fun))
3579 0 : return eval_builtin_function_call (ctx, t, fun, lval, non_constant_p,
3580 0 : overflow_p, jump_target);
3581 :
3582 2103 : bool non_constant_args = false;
3583 2103 : new_call.bindings
3584 2103 : = rs_bind_parameters_in_call (ctx, t, fun, non_constant_p, overflow_p,
3585 : &non_constant_args, jump_target);
3586 :
3587 : /* We build up the bindings list before we know whether we already have this
3588 : call cached. If we don't end up saving these bindings, ggc_free them when
3589 : this function exits. */
3590 2103 : class free_bindings
3591 : {
3592 : tree *bindings;
3593 :
3594 : public:
3595 2103 : free_bindings (tree &b) : bindings (&b) {}
3596 2103 : ~free_bindings ()
3597 : {
3598 2103 : if (bindings)
3599 0 : ggc_free (*bindings);
3600 2103 : }
3601 2103 : void preserve () { bindings = NULL; }
3602 2103 : } fb (new_call.bindings);
3603 :
3604 2103 : if (*non_constant_p)
3605 : return t;
3606 :
3607 : /* If in direct recursive call, optimize definition search. */
3608 2103 : if (ctx && ctx->call && ctx->call->fundef && ctx->call->fundef->decl == fun)
3609 0 : new_call.fundef = ctx->call->fundef;
3610 : else
3611 : {
3612 2103 : new_call.fundef = retrieve_constexpr_fundef (fun);
3613 2103 : if (new_call.fundef == NULL || new_call.fundef->body == NULL
3614 2103 : || new_call.fundef->result == error_mark_node
3615 2103 : || fun == current_function_decl)
3616 : {
3617 0 : if (!ctx->quiet)
3618 : {
3619 : /* We need to check for current_function_decl here in case we're
3620 : being called during cp_fold_function, because at that point
3621 : DECL_INITIAL is set properly and we have a fundef but we
3622 : haven't lowered invisirefs yet (c++/70344). */
3623 0 : if (DECL_INITIAL (fun) == error_mark_node
3624 0 : || fun == current_function_decl)
3625 0 : error_at (loc,
3626 : "%qD called in a constant expression before its "
3627 : "definition is complete",
3628 : fun);
3629 0 : else if (DECL_INITIAL (fun))
3630 : {
3631 : // /* The definition of fun was somehow unsuitable. But
3632 : // pretend
3633 : // that lambda static thunks don't exist. */
3634 : // if (!lambda_static_thunk_p (fun))
3635 : // error_at (loc, "%qD called in a constant expression",
3636 : // fun);
3637 0 : explain_invalid_constexpr_fn (fun);
3638 : }
3639 : else
3640 0 : error_at (loc, "%qD used before its definition", fun);
3641 : }
3642 0 : *non_constant_p = true;
3643 0 : return t;
3644 : }
3645 : }
3646 :
3647 2103 : depth_ok = push_cx_call_context (t);
3648 :
3649 2103 : tree result = NULL_TREE;
3650 2103 : rust_constexpr_call *entry = NULL;
3651 2103 : if (depth_ok && !non_constant_args && ctx->strict)
3652 : {
3653 2103 : new_call.hash = rust_constexpr_fundef_hasher::hash (new_call.fundef);
3654 2103 : new_call.hash = iterative_hash_object (new_call.bindings, new_call.hash);
3655 2103 : new_call.hash
3656 2103 : = iterative_hash_object (ctx->manifestly_const_eval, new_call.hash);
3657 :
3658 : /* If we have seen this call before, we are done. */
3659 2103 : maybe_initialize_constexpr_call_table ();
3660 2103 : rust_constexpr_call **slot
3661 2103 : = constexpr_call_table->find_slot (&new_call, INSERT);
3662 2103 : entry = *slot;
3663 2103 : if (entry == NULL)
3664 : {
3665 : /* Only cache up to constexpr_cache_depth to limit memory use. */
3666 2103 : if (depth_ok < constexpr_cache_depth)
3667 : {
3668 : /* We need to keep a pointer to the entry, not just the slot, as
3669 : the slot can move during evaluation of the body. */
3670 2103 : *slot = entry = ggc_alloc<rust_constexpr_call> ();
3671 2103 : *entry = new_call;
3672 2103 : fb.preserve ();
3673 : }
3674 : }
3675 : /* Calls that are in progress have their result set to NULL, so that we
3676 : can detect circular dependencies. Now that we only cache up to
3677 : constexpr_cache_depth this won't catch circular dependencies that
3678 : start deeper, but they'll hit the recursion or ops limit. */
3679 0 : else if (entry->result == NULL)
3680 : {
3681 0 : if (!ctx->quiet)
3682 0 : error ("call has circular dependency");
3683 0 : *non_constant_p = true;
3684 0 : entry->result = result = error_mark_node;
3685 : }
3686 : else
3687 : result = entry->result;
3688 : }
3689 :
3690 2103 : if (!depth_ok)
3691 : {
3692 0 : if (!ctx->quiet)
3693 0 : error ("%<constexpr%> evaluation depth exceeds maximum of %d (use "
3694 : "%<-fconstexpr-depth=%> to increase the maximum)",
3695 : max_constexpr_depth);
3696 0 : *non_constant_p = true;
3697 0 : result = error_mark_node;
3698 : }
3699 : else
3700 : {
3701 2103 : bool cacheable = true;
3702 2103 : if (result && result != error_mark_node)
3703 : /* OK */;
3704 2103 : else if (!DECL_SAVED_TREE (fun))
3705 : {
3706 : /* When at_eof >= 2, cgraph has started throwing away
3707 : DECL_SAVED_TREE, so fail quietly. FIXME we get here because of
3708 : late code generation for VEC_INIT_EXPR, which needs to be
3709 : completely reconsidered. */
3710 : // gcc_assert (at_eof >= 2 && ctx->quiet);
3711 0 : *non_constant_p = true;
3712 : }
3713 2103 : else if (tree copy = get_fundef_copy (new_call.fundef))
3714 : {
3715 2103 : tree body, parms, res;
3716 2103 : releasing_vec ctors;
3717 :
3718 : /* Reuse or create a new unshared copy of this function's body. */
3719 2103 : body = TREE_PURPOSE (copy);
3720 2103 : parms = TREE_VALUE (copy);
3721 2103 : res = TREE_TYPE (copy);
3722 :
3723 : /* Associate the bindings with the remapped parms. */
3724 2103 : tree bound = new_call.bindings;
3725 2103 : tree remapped = parms;
3726 2106 : for (int i = 0; i < TREE_VEC_LENGTH (bound); ++i)
3727 : {
3728 3 : tree arg = TREE_VEC_ELT (bound, i);
3729 3 : if (entry)
3730 : {
3731 : /* Unshare args going into the hash table to separate them
3732 : from the caller's context, for better GC and to avoid
3733 : problems with verify_gimple. */
3734 3 : arg = unshare_expr_without_location (arg);
3735 3 : TREE_VEC_ELT (bound, i) = arg;
3736 :
3737 : /* And then unshare again so the callee doesn't change the
3738 : argument values in the hash table. XXX Could we unshare
3739 : lazily in cxx_eval_store_expression? */
3740 3 : arg = unshare_constructor (arg);
3741 3 : if (TREE_CODE (arg) == CONSTRUCTOR)
3742 0 : vec_safe_push (ctors, arg);
3743 : }
3744 :
3745 3 : ctx->global->values.put (remapped, arg);
3746 3 : remapped = DECL_CHAIN (remapped);
3747 : }
3748 : /* Add the RESULT_DECL to the values map, too. */
3749 2103 : gcc_assert (!DECL_BY_REFERENCE (res));
3750 2103 : ctx->global->values.put (res, NULL_TREE);
3751 :
3752 : /* Track the callee's evaluated SAVE_EXPRs and TARGET_EXPRs so that
3753 : we can forget their values after the call. */
3754 2103 : constexpr_ctx ctx_with_save_exprs = *ctx;
3755 2103 : auto_vec<tree, 10> save_exprs;
3756 2103 : ctx_with_save_exprs.save_exprs = &save_exprs;
3757 2103 : ctx_with_save_exprs.call = &new_call;
3758 2103 : unsigned save_heap_alloc_count = ctx->global->heap_vars.length ();
3759 2103 : unsigned save_heap_dealloc_count = ctx->global->heap_dealloc_count;
3760 :
3761 2103 : tree jump_target = NULL_TREE;
3762 2103 : eval_constant_expression (&ctx_with_save_exprs, body, lval,
3763 : non_constant_p, overflow_p, &jump_target);
3764 :
3765 2103 : if (VOID_TYPE_P (TREE_TYPE (res)))
3766 0 : result = void_node;
3767 : else
3768 : {
3769 2103 : result = *ctx->global->values.get (res);
3770 2103 : if (result == NULL_TREE && !*non_constant_p)
3771 : {
3772 7 : *non_constant_p = true;
3773 : }
3774 : }
3775 :
3776 : /* Forget the saved values of the callee's SAVE_EXPRs and
3777 : TARGET_EXPRs. */
3778 6309 : for (tree save_expr : save_exprs)
3779 0 : ctx->global->values.remove (save_expr);
3780 :
3781 : /* Remove the parms/result from the values map. Is it worth
3782 : bothering to do this when the map itself is only live for
3783 : one constexpr evaluation? If so, maybe also clear out
3784 : other vars from call, maybe in BIND_EXPR handling? */
3785 2103 : ctx->global->values.remove (res);
3786 2106 : for (tree parm = parms; parm; parm = TREE_CHAIN (parm))
3787 3 : ctx->global->values.remove (parm);
3788 :
3789 : /* Make the unshared function copy we used available for re-use. */
3790 2103 : save_fundef_copy (fun, copy);
3791 :
3792 : /* If the call allocated some heap object that hasn't been
3793 : deallocated during the call, or if it deallocated some heap
3794 : object it has not allocated, the call isn't really stateless
3795 : for the constexpr evaluation and should not be cached.
3796 : It is fine if the call allocates something and deallocates it
3797 : too. */
3798 2103 : if (entry
3799 4206 : && (save_heap_alloc_count != ctx->global->heap_vars.length ()
3800 2103 : || (save_heap_dealloc_count
3801 2103 : != ctx->global->heap_dealloc_count)))
3802 : {
3803 0 : tree heap_var;
3804 0 : unsigned int i;
3805 0 : if ((ctx->global->heap_vars.length ()
3806 0 : - ctx->global->heap_dealloc_count)
3807 0 : != save_heap_alloc_count - save_heap_dealloc_count)
3808 : cacheable = false;
3809 : else
3810 2103 : FOR_EACH_VEC_ELT_FROM (ctx->global->heap_vars, i, heap_var,
3811 : save_heap_alloc_count)
3812 0 : if (DECL_NAME (heap_var) != heap_deleted_identifier)
3813 : {
3814 : cacheable = false;
3815 : break;
3816 : }
3817 : }
3818 2103 : }
3819 : else
3820 : /* Couldn't get a function copy to evaluate. */
3821 0 : *non_constant_p = true;
3822 :
3823 2103 : if (result == error_mark_node)
3824 0 : *non_constant_p = true;
3825 2103 : if (*non_constant_p || *overflow_p)
3826 : result = error_mark_node;
3827 2091 : else if (!result)
3828 0 : result = void_node;
3829 2103 : if (entry)
3830 2103 : entry->result = cacheable ? result : error_mark_node;
3831 : }
3832 :
3833 2103 : pop_cx_call_context ();
3834 2103 : return result;
3835 2103 : }
3836 :
3837 : /* Subroutine of build_data_member_initialization. MEMBER is a COMPONENT_REF
3838 : for a member of an anonymous aggregate, INIT is the initializer for that
3839 : member, and VEC_OUTER is the vector of constructor elements for the class
3840 : whose constructor we are processing. Add the initializer to the vector
3841 : and return true to indicate success. */
3842 :
3843 : // static bool
3844 : // build_anon_member_initialization (tree member, tree init,
3845 : // vec<constructor_elt, va_gc> **vec_outer)
3846 : // {
3847 : // /* MEMBER presents the relevant fields from the inside out, but we need
3848 : // to build up the initializer from the outside in so that we can reuse
3849 : // previously built CONSTRUCTORs if this is, say, the second field in an
3850 : // anonymous struct. So we use a vec as a stack. */
3851 : // auto_vec<tree, 2> fields;
3852 : // do
3853 : // {
3854 : // fields.safe_push (TREE_OPERAND (member, 1));
3855 : // member = TREE_OPERAND (member, 0);
3856 : // } while (ANON_AGGR_TYPE_P (TREE_TYPE (member))
3857 : // && TREE_CODE (member) == COMPONENT_REF);
3858 : //
3859 : // /* VEC has the constructor elements vector for the context of FIELD.
3860 : // If FIELD is an anonymous aggregate, we will push inside it. */
3861 : // vec<constructor_elt, va_gc> **vec = vec_outer;
3862 : // tree field;
3863 : // while (field = fields.pop (), ANON_AGGR_TYPE_P (TREE_TYPE (field)))
3864 : // {
3865 : // tree ctor;
3866 : // /* If there is already an outer constructor entry for the anonymous
3867 : // aggregate FIELD, use it; otherwise, insert one. */
3868 : // if (vec_safe_is_empty (*vec) || (*vec)->last ().index != field)
3869 : // {
3870 : // ctor = build_constructor (TREE_TYPE (field), NULL);
3871 : // CONSTRUCTOR_APPEND_ELT (*vec, field, ctor);
3872 : // }
3873 : // else
3874 : // ctor = (*vec)->last ().value;
3875 : // vec = &CONSTRUCTOR_ELTS (ctor);
3876 : // }
3877 : //
3878 : // /* Now we're at the innermost field, the one that isn't an anonymous
3879 : // aggregate. Add its initializer to the CONSTRUCTOR and we're done. */
3880 : // gcc_assert (fields.is_empty ());
3881 : // CONSTRUCTOR_APPEND_ELT (*vec, field, init);
3882 : //
3883 : // return true;
3884 : // }
3885 :
3886 : ///* V is a vector of constructor elements built up for the base and member
3887 : // initializers of a constructor for TYPE. They need to be in increasing
3888 : // offset order, which they might not be yet if TYPE has a primary base
3889 : // which is not first in the base-clause or a vptr and at least one base
3890 : // all of which are non-primary. */
3891 : //
3892 : // static vec<constructor_elt, va_gc> *
3893 : // sort_constexpr_mem_initializers (tree type, vec<constructor_elt, va_gc> *v)
3894 : //{
3895 : // tree pri = CLASSTYPE_PRIMARY_BINFO (type);
3896 : // tree field_type;
3897 : // unsigned i;
3898 : // constructor_elt *ce;
3899 : //
3900 : // if (pri)
3901 : // field_type = BINFO_TYPE (pri);
3902 : // else if (TYPE_CONTAINS_VPTR_P (type))
3903 : // field_type = vtbl_ptr_type_node;
3904 : // else
3905 : // return v;
3906 : //
3907 : // /* Find the element for the primary base or vptr and move it to the
3908 : // beginning of the vec. */
3909 : // for (i = 0; vec_safe_iterate (v, i, &ce); ++i)
3910 : // if (TREE_TYPE (ce->index) == field_type)
3911 : // break;
3912 : //
3913 : // if (i > 0 && i < vec_safe_length (v))
3914 : // {
3915 : // vec<constructor_elt, va_gc> &vref = *v;
3916 : // constructor_elt elt = vref[i];
3917 : // for (; i > 0; --i)
3918 : // vref[i] = vref[i - 1];
3919 : // vref[0] = elt;
3920 : // }
3921 : //
3922 : // return v;
3923 : //}
3924 :
3925 : /* Subroutine of build_constexpr_constructor_member_initializers.
3926 : The expression tree T represents a data member initialization
3927 : in a (constexpr) constructor definition. Build a pairing of
3928 : the data member with its initializer, and prepend that pair
3929 : to the existing initialization pair INITS. */
3930 :
3931 : static bool
3932 0 : build_data_member_initialization (tree t, vec<constructor_elt, va_gc> **vec)
3933 : {
3934 0 : tree member;
3935 0 : if (TREE_CODE (t) == CLEANUP_POINT_EXPR)
3936 0 : t = TREE_OPERAND (t, 0);
3937 0 : if (TREE_CODE (t) == EXPR_STMT)
3938 0 : t = TREE_OPERAND (t, 0);
3939 0 : if (t == error_mark_node)
3940 : return false;
3941 0 : if (TREE_CODE (t) == STATEMENT_LIST)
3942 : {
3943 0 : for (tree stmt : tsi_range (t))
3944 0 : if (!build_data_member_initialization (stmt, vec))
3945 0 : return false;
3946 : return true;
3947 : }
3948 0 : if (TREE_CODE (t) == CONVERT_EXPR)
3949 0 : t = TREE_OPERAND (t, 0);
3950 0 : if (TREE_CODE (t) == INIT_EXPR
3951 : /* vptr initialization shows up as a MODIFY_EXPR. In C++14 we only
3952 : use what this function builds for cx_check_missing_mem_inits, and
3953 : assignment in the ctor body doesn't count. */
3954 0 : || (TREE_CODE (t) == MODIFY_EXPR))
3955 : {
3956 0 : member = TREE_OPERAND (t, 0);
3957 : // Faisal: not sure if we need to port over break_out_target_exprs
3958 : // if not, then not sure how to handle init in this case
3959 : // init = break_out_target_exprs (TREE_OPERAND (t, 1));
3960 : }
3961 0 : else if (TREE_CODE (t) == CALL_EXPR)
3962 : {
3963 0 : tree fn = get_callee_fndecl (t);
3964 0 : if (!fn || !DECL_CONSTRUCTOR_P (fn))
3965 : /* We're only interested in calls to subobject constructors. */
3966 : return true;
3967 0 : member = CALL_EXPR_ARG (t, 0);
3968 : /* We don't use build_cplus_new here because it complains about
3969 : abstract bases. Leaving the call unwrapped means that it has the
3970 : wrong type, but cxx_eval_constant_expression doesn't care. */
3971 : // Faisal: not sure if we need to port over break_out_target_exprs
3972 : // if not, then not sure how to handle init in this case
3973 : // init = break_out_target_exprs (t);
3974 : }
3975 0 : else if (TREE_CODE (t) == BIND_EXPR)
3976 0 : return build_data_member_initialization (BIND_EXPR_BODY (t), vec);
3977 : else
3978 : /* Don't add anything else to the CONSTRUCTOR. */
3979 : return true;
3980 0 : if (INDIRECT_REF_P (member))
3981 0 : member = TREE_OPERAND (member, 0);
3982 0 : if (TREE_CODE (member) == NOP_EXPR)
3983 : {
3984 0 : tree op = member;
3985 0 : STRIP_NOPS (op);
3986 0 : if (TREE_CODE (op) == ADDR_EXPR)
3987 : {
3988 0 : gcc_assert (same_type_ignoring_top_level_qualifiers_p (
3989 : TREE_TYPE (TREE_TYPE (op)), TREE_TYPE (TREE_TYPE (member))));
3990 : /* Initializing a cv-qualified member; we need to look through
3991 : the const_cast. */
3992 : member = op;
3993 : }
3994 0 : else if (op == current_class_ptr
3995 0 : && (same_type_ignoring_top_level_qualifiers_p (
3996 0 : TREE_TYPE (TREE_TYPE (member)), current_class_type)))
3997 : /* Delegating constructor. */
3998 : member = op;
3999 : else
4000 : {
4001 : /* This is an initializer for an empty base; keep it for now so
4002 : we can check it in cxx_eval_bare_aggregate. */
4003 0 : gcc_assert (is_empty_class (TREE_TYPE (TREE_TYPE (member))));
4004 : }
4005 : }
4006 0 : if (TREE_CODE (member) == ADDR_EXPR)
4007 0 : member = TREE_OPERAND (member, 0);
4008 0 : if (TREE_CODE (member) == COMPONENT_REF)
4009 : {
4010 0 : tree aggr = TREE_OPERAND (member, 0);
4011 0 : if (TREE_CODE (aggr) == VAR_DECL)
4012 : /* Initializing a local variable, don't add anything. */
4013 : return true;
4014 0 : if (TREE_CODE (aggr) != COMPONENT_REF)
4015 : /* Normal member initialization. */
4016 0 : member = TREE_OPERAND (member, 1);
4017 0 : else if (ANON_AGGR_TYPE_P (TREE_TYPE (aggr)))
4018 : /* Initializing a member of an anonymous union. */
4019 0 : rust_sorry_at (UNDEF_LOCATION,
4020 : "cannot handle value initialization yet");
4021 : // return build_anon_member_initialization (member, init, vec);
4022 : else
4023 : /* We're initializing a vtable pointer in a base. Leave it as
4024 : COMPONENT_REF so we remember the path to get to the vfield. */
4025 0 : gcc_assert (TREE_TYPE (member) == vtbl_ptr_type_node);
4026 : }
4027 :
4028 : /* Value-initialization can produce multiple initializers for the
4029 : same field; use the last one. */
4030 0 : if (!vec_safe_is_empty (*vec) && (*vec)->last ().index == member)
4031 0 : rust_sorry_at (UNDEF_LOCATION, "cannot handle value initialization yet");
4032 : // (*vec)->last ().value = init;
4033 : else
4034 0 : rust_sorry_at (UNDEF_LOCATION, "cannot handle value initialization yet");
4035 : // CONSTRUCTOR_APPEND_ELT (*vec, member, init);
4036 : return true;
4037 : }
4038 :
4039 : ///* Build compile-time evalable representations of member-initializer list
4040 : // for a constexpr constructor. */
4041 : //
4042 : // static tree
4043 : // build_constexpr_constructor_member_initializers (tree type, tree body)
4044 : //{
4045 : // vec<constructor_elt, va_gc> *vec = NULL;
4046 : // bool ok = true;
4047 : // while (true)
4048 : // switch (TREE_CODE (body))
4049 : // {
4050 : // case STATEMENT_LIST:
4051 : // for (tree stmt : tsi_range (body))
4052 : // {
4053 : // body = stmt;
4054 : // if (TREE_CODE (body) == BIND_EXPR)
4055 : // break;
4056 : // }
4057 : // break;
4058 : //
4059 : // case BIND_EXPR:
4060 : // body = BIND_EXPR_BODY (body);
4061 : // goto found;
4062 : //
4063 : // default:
4064 : // rust_unreachable ();
4065 : // }
4066 : // found:
4067 : //
4068 : // if (TREE_CODE (body) == CLEANUP_POINT_EXPR)
4069 : // {
4070 : // body = TREE_OPERAND (body, 0);
4071 : // if (TREE_CODE (body) == EXPR_STMT)
4072 : // body = TREE_OPERAND (body, 0);
4073 : // if (TREE_CODE (body) == INIT_EXPR
4074 : // && (same_type_ignoring_top_level_qualifiers_p (
4075 : // TREE_TYPE (TREE_OPERAND (body, 0)), current_class_type)))
4076 : // {
4077 : // /* Trivial copy. */
4078 : // return TREE_OPERAND (body, 1);
4079 : // }
4080 : // ok = build_data_member_initialization (body, &vec);
4081 : // }
4082 : // else if (TREE_CODE (body) == STATEMENT_LIST)
4083 : // {
4084 : // for (tree stmt : tsi_range (body))
4085 : // {
4086 : // ok = build_data_member_initialization (stmt, &vec);
4087 : // if (!ok)
4088 : // break;
4089 : // }
4090 : // }
4091 : // else if (EXPR_P (body))
4092 : // ok = build_data_member_initialization (body, &vec);
4093 : // else
4094 : // gcc_assert (errorcount > 0);
4095 : // if (ok)
4096 : // {
4097 : // if (vec_safe_length (vec) > 0)
4098 : // {
4099 : // /* In a delegating constructor, return the target. */
4100 : // constructor_elt *ce = &(*vec)[0];
4101 : // if (ce->index == current_class_ptr)
4102 : // {
4103 : // body = ce->value;
4104 : // vec_free (vec);
4105 : // return body;
4106 : // }
4107 : // }
4108 : // vec = sort_constexpr_mem_initializers (type, vec);
4109 : // return build_constructor (type, vec);
4110 : // }
4111 : // else
4112 : // return error_mark_node;
4113 : //}
4114 :
4115 : // Subroutine of check_constexpr_fundef. BODY is the body of a function
4116 : // declared to be constexpr, or a sub-statement thereof. Returns the
4117 : // return value if suitable, error_mark_node for a statement not allowed in
4118 : // a constexpr function, or NULL_TREE if no return value was found.
4119 : static tree
4120 0 : constexpr_fn_retval (const constexpr_ctx *ctx, tree body)
4121 : {
4122 0 : switch (TREE_CODE (body))
4123 : {
4124 0 : case STATEMENT_LIST:
4125 0 : {
4126 0 : tree expr = NULL_TREE;
4127 0 : for (tree stmt : tsi_range (body))
4128 : {
4129 0 : tree s = constexpr_fn_retval (ctx, stmt);
4130 0 : if (s == error_mark_node)
4131 : return error_mark_node;
4132 0 : else if (s == NULL_TREE)
4133 : /* Keep iterating. */;
4134 0 : else if (expr)
4135 : /* Multiple return statements. */
4136 : return error_mark_node;
4137 : else
4138 : expr = s;
4139 : }
4140 : return expr;
4141 : }
4142 :
4143 0 : case RETURN_EXPR:
4144 0 : {
4145 0 : bool non_constant_p = false;
4146 0 : bool overflow_p = false;
4147 0 : return eval_constant_expression (ctx, body, false, &non_constant_p,
4148 : &overflow_p, NULL);
4149 : }
4150 0 : case DECL_EXPR:
4151 0 : {
4152 0 : tree decl = DECL_EXPR_DECL (body);
4153 0 : if (TREE_CODE (decl) == USING_DECL
4154 : /* Accept __func__, __FUNCTION__, and __PRETTY_FUNCTION__. */
4155 0 : || DECL_ARTIFICIAL (decl))
4156 : return NULL_TREE;
4157 0 : return error_mark_node;
4158 : }
4159 :
4160 0 : case CLEANUP_POINT_EXPR:
4161 0 : return constexpr_fn_retval (ctx, TREE_OPERAND (body, 0));
4162 :
4163 0 : case BIND_EXPR:
4164 0 : {
4165 0 : tree b = BIND_EXPR_BODY (body);
4166 0 : return constexpr_fn_retval (ctx, b);
4167 : }
4168 0 : break;
4169 :
4170 0 : default:
4171 0 : return error_mark_node;
4172 : }
4173 : return error_mark_node;
4174 : }
4175 :
4176 : // Taken from cp/constexpr.cc
4177 : //
4178 : // If DECL is a scalar enumeration constant or variable with a
4179 : // constant initializer, return the initializer (or, its initializers,
4180 : // recursively); otherwise, return DECL. If STRICT_P, the
4181 : // initializer is only returned if DECL is a
4182 : // constant-expression. If RETURN_AGGREGATE_CST_OK_P, it is ok to
4183 : // return an aggregate constant. If UNSHARE_P, return an unshared
4184 : // copy of the initializer.
4185 : static tree
4186 1297 : constant_value_1 (tree decl, bool, bool, bool unshare_p)
4187 : {
4188 2593 : while (TREE_CODE (decl) == CONST_DECL)
4189 : {
4190 1296 : tree init;
4191 : /* If DECL is a static data member in a template
4192 : specialization, we must instantiate it here. The
4193 : initializer for the static data member is not processed
4194 : until needed; we need it now. */
4195 :
4196 1296 : init = DECL_INITIAL (decl);
4197 1296 : if (init == error_mark_node)
4198 : {
4199 : if (TREE_CODE (decl) == CONST_DECL)
4200 : /* Treat the error as a constant to avoid cascading errors on
4201 : excessively recursive template instantiation (c++/9335). */
4202 : return init;
4203 : else
4204 : return decl;
4205 : }
4206 :
4207 : decl = init;
4208 : }
4209 1297 : return unshare_p ? unshare_expr (decl) : decl;
4210 : }
4211 :
4212 : /* Like scalar_constant_value, but can also return aggregate initializers.
4213 : If UNSHARE_P, return an unshared copy of the initializer. */
4214 :
4215 : tree
4216 1297 : decl_really_constant_value (tree decl, bool unshare_p /*= true*/)
4217 : {
4218 1297 : return constant_value_1 (decl, /*strict_p=*/true,
4219 : /*return_aggregate_cst_ok_p=*/true,
4220 0 : /*unshare_p=*/unshare_p);
4221 : }
4222 :
4223 : // A more relaxed version of decl_really_constant_value, used by the
4224 : // common C/C++ code.
4225 : tree
4226 0 : decl_constant_value (tree decl, bool unshare_p)
4227 : {
4228 0 : return constant_value_1 (decl, /*strict_p=*/false,
4229 : /*return_aggregate_cst_ok_p=*/true,
4230 0 : /*unshare_p=*/unshare_p);
4231 : }
4232 :
4233 : static void
4234 1 : non_const_var_error (location_t loc, tree r)
4235 : {
4236 1 : tree type = TREE_TYPE (r);
4237 :
4238 : /* Avoid error cascade. */
4239 1 : if (DECL_INITIAL (r) == error_mark_node)
4240 : return;
4241 1 : if (DECL_DECLARED_CONSTEXPR_P (r))
4242 0 : inform (DECL_SOURCE_LOCATION (r), "%qD used in its own initializer", r);
4243 1 : else if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
4244 : {
4245 1 : if (!DECL_INITIAL (r) || !TREE_CONSTANT (DECL_INITIAL (r))
4246 1 : || !DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r))
4247 1 : inform (DECL_SOURCE_LOCATION (r),
4248 : "%qD was not initialized with a constant "
4249 : "expression",
4250 : r);
4251 : else
4252 0 : gcc_unreachable ();
4253 : }
4254 0 : else if (TYPE_REF_P (type))
4255 0 : inform (DECL_SOURCE_LOCATION (r),
4256 : "%qD was not initialized with a constant "
4257 : "expression",
4258 : r);
4259 : else
4260 : {
4261 0 : if (!DECL_DECLARED_CONSTEXPR_P (r))
4262 0 : inform (DECL_SOURCE_LOCATION (r), "%qD was not declared %<constexpr%>",
4263 : r);
4264 : else
4265 0 : inform (DECL_SOURCE_LOCATION (r),
4266 : "%qD does not have integral or enumeration type", r);
4267 : }
4268 : }
4269 :
4270 : static tree
4271 2103 : get_callee (tree call)
4272 : {
4273 2103 : if (call == NULL_TREE)
4274 : return call;
4275 2103 : else if (TREE_CODE (call) == CALL_EXPR)
4276 2103 : return CALL_EXPR_FN (call);
4277 :
4278 : return NULL_TREE;
4279 : }
4280 :
4281 : // We have an expression tree T that represents a call, either CALL_EXPR
4282 : // or AGGR_INIT_EXPR. If the call is lexically to a named function,
4283 : // return the _DECL for that function.
4284 : static tree
4285 2103 : get_function_named_in_call (tree t)
4286 : {
4287 2103 : tree fun = get_callee (t);
4288 2103 : if (fun && TREE_CODE (fun) == ADDR_EXPR
4289 2463 : && TREE_CODE (TREE_OPERAND (fun, 0)) == FUNCTION_DECL)
4290 360 : fun = TREE_OPERAND (fun, 0);
4291 2103 : return fun;
4292 : }
4293 :
4294 : // forked from gcc/cp/constexpr.cc maybe_constexpr_fn
4295 :
4296 : /* True if a function might be declared constexpr */
4297 :
4298 : bool
4299 0 : maybe_constexpr_fn (tree t)
4300 : {
4301 0 : return (DECL_DECLARED_CONSTEXPR_P (t));
4302 : }
4303 :
4304 : // forked from gcc/cp/constexpr.cc var_in_maybe_constexpr_fn
4305 :
4306 : /* True if T was declared in a function that might be constexpr: either a
4307 : function that was declared constexpr. */
4308 :
4309 : bool
4310 0 : var_in_maybe_constexpr_fn (tree t)
4311 : {
4312 0 : return (DECL_FUNCTION_SCOPE_P (t) && maybe_constexpr_fn (DECL_CONTEXT (t)));
4313 : }
4314 :
4315 : /* P0859: A function is needed for constant evaluation if it is a constexpr
4316 : function that is named by an expression ([basic.def.odr]) that is
4317 : potentially constant evaluated.
4318 :
4319 : So we need to instantiate any constexpr functions mentioned by the
4320 : expression even if the definition isn't needed for evaluating the
4321 : expression. */
4322 :
4323 : static tree
4324 0 : instantiate_cx_fn_r (tree *tp, int *walk_subtrees, void * /*data*/)
4325 : {
4326 0 : if (TREE_CODE (*tp) == CALL_EXPR)
4327 : {
4328 0 : if (EXPR_HAS_LOCATION (*tp))
4329 0 : input_location = EXPR_LOCATION (*tp);
4330 : }
4331 :
4332 0 : if (!EXPR_P (*tp))
4333 0 : *walk_subtrees = 0;
4334 :
4335 0 : return NULL_TREE;
4336 : }
4337 :
4338 : static void
4339 0 : instantiate_constexpr_fns (tree t)
4340 : {
4341 0 : location_t loc = input_location;
4342 0 : rs_walk_tree_without_duplicates (&t, instantiate_cx_fn_r, NULL);
4343 0 : input_location = loc;
4344 0 : }
4345 :
4346 : /* Returns less than, equal to, or greater than zero if KEY is found to be
4347 : less than, to match, or to be greater than the constructor_elt's INDEX. */
4348 :
4349 : static int
4350 0 : array_index_cmp (tree key, tree index)
4351 : {
4352 0 : gcc_assert (TREE_CODE (key) == INTEGER_CST);
4353 :
4354 0 : switch (TREE_CODE (index))
4355 : {
4356 0 : case INTEGER_CST:
4357 0 : return tree_int_cst_compare (key, index);
4358 0 : case RANGE_EXPR:
4359 0 : {
4360 0 : tree lo = TREE_OPERAND (index, 0);
4361 0 : tree hi = TREE_OPERAND (index, 1);
4362 0 : if (tree_int_cst_lt (key, lo))
4363 : return -1;
4364 0 : else if (tree_int_cst_lt (hi, key))
4365 : return 1;
4366 : else
4367 0 : return 0;
4368 : }
4369 0 : default:
4370 0 : rust_unreachable ();
4371 : }
4372 : }
4373 :
4374 : /* If T is a CONSTRUCTOR, return an unshared copy of T and any
4375 : sub-CONSTRUCTORs. Otherwise return T.
4376 :
4377 : We use this whenever we initialize an object as a whole, whether it's a
4378 : parameter, a local variable, or a subobject, so that subsequent
4379 : modifications don't affect other places where it was used. */
4380 :
4381 : tree
4382 2145 : unshare_constructor (tree t MEM_STAT_DECL)
4383 : {
4384 2145 : if (!t || TREE_CODE (t) != CONSTRUCTOR)
4385 : return t;
4386 63 : auto_vec<tree *, 4> ptrs;
4387 63 : ptrs.safe_push (&t);
4388 63 : while (!ptrs.is_empty ())
4389 : {
4390 66 : tree *p = ptrs.pop ();
4391 66 : tree n = copy_node (*p PASS_MEM_STAT);
4392 132 : CONSTRUCTOR_ELTS (n)
4393 127 : = vec_safe_copy (CONSTRUCTOR_ELTS (*p) PASS_MEM_STAT);
4394 66 : *p = n;
4395 66 : vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (n);
4396 66 : constructor_elt *ce;
4397 585 : for (HOST_WIDE_INT i = 0; vec_safe_iterate (v, i, &ce); ++i)
4398 390 : if (ce->value && TREE_CODE (ce->value) == CONSTRUCTOR)
4399 3 : ptrs.safe_push (&ce->value);
4400 : }
4401 63 : return t;
4402 63 : }
4403 :
4404 : /* Returns the index of the constructor_elt of ARY which matches DINDEX, or -1
4405 : if none. If INSERT is true, insert a matching element rather than fail. */
4406 :
4407 : static HOST_WIDE_INT
4408 9 : find_array_ctor_elt (tree ary, tree dindex, bool insert)
4409 : {
4410 9 : if (tree_int_cst_sgn (dindex) < 0)
4411 : return -1;
4412 :
4413 9 : unsigned HOST_WIDE_INT i = tree_to_uhwi (dindex);
4414 9 : vec<constructor_elt, va_gc> *elts = CONSTRUCTOR_ELTS (ary);
4415 9 : unsigned HOST_WIDE_INT len = vec_safe_length (elts);
4416 :
4417 9 : unsigned HOST_WIDE_INT end = len;
4418 9 : unsigned HOST_WIDE_INT begin = 0;
4419 :
4420 : /* If the last element of the CONSTRUCTOR has its own index, we can assume
4421 : that the same is true of the other elements and index directly. */
4422 9 : if (end > 0)
4423 : {
4424 9 : tree cindex = (*elts)[end - 1].index;
4425 9 : if (cindex == NULL_TREE)
4426 : {
4427 : /* Verify that if the last index is missing, all indexes
4428 : are missing. */
4429 0 : if (flag_checking)
4430 0 : for (unsigned int j = 0; j < len - 1; ++j)
4431 0 : gcc_assert ((*elts)[j].index == NULL_TREE);
4432 0 : if (i < end)
4433 0 : return i;
4434 : else
4435 : {
4436 0 : begin = end;
4437 0 : if (i == end)
4438 : /* If the element is to be added right at the end,
4439 : make sure it is added with cleared index too. */
4440 0 : dindex = NULL_TREE;
4441 0 : else if (insert)
4442 : /* Otherwise, in order not to break the assumption
4443 : that CONSTRUCTOR either has all indexes or none,
4444 : we need to add indexes to all elements. */
4445 0 : for (unsigned int j = 0; j < len; ++j)
4446 0 : (*elts)[j].index = build_int_cst (TREE_TYPE (dindex), j);
4447 : }
4448 : }
4449 9 : else if (TREE_CODE (cindex) == INTEGER_CST
4450 9 : && compare_tree_int (cindex, end - 1) == 0)
4451 : {
4452 9 : if (i < end)
4453 9 : return i;
4454 : else
4455 0 : begin = end;
4456 : }
4457 : }
4458 :
4459 : /* Otherwise, find a matching index by means of a binary search. */
4460 0 : while (begin != end)
4461 : {
4462 0 : unsigned HOST_WIDE_INT middle = (begin + end) / 2;
4463 0 : constructor_elt &elt = (*elts)[middle];
4464 0 : tree idx = elt.index;
4465 :
4466 0 : int cmp = array_index_cmp (dindex, idx);
4467 0 : if (cmp < 0)
4468 : end = middle;
4469 0 : else if (cmp > 0)
4470 0 : begin = middle + 1;
4471 : else
4472 : {
4473 0 : if (insert && TREE_CODE (idx) == RANGE_EXPR)
4474 : {
4475 : /* We need to split the range. */
4476 0 : constructor_elt e;
4477 0 : tree lo = TREE_OPERAND (idx, 0);
4478 0 : tree hi = TREE_OPERAND (idx, 1);
4479 0 : tree value = elt.value;
4480 0 : dindex = fold_convert (sizetype, dindex);
4481 0 : if (tree_int_cst_lt (lo, dindex))
4482 : {
4483 : /* There are still some lower elts; shorten the range. */
4484 0 : tree new_hi
4485 0 : = int_const_binop (MINUS_EXPR, dindex, size_one_node);
4486 0 : if (tree_int_cst_equal (lo, new_hi))
4487 : /* Only one element left, no longer a range. */
4488 0 : elt.index = lo;
4489 : else
4490 0 : TREE_OPERAND (idx, 1) = new_hi;
4491 : /* Append the element we want to insert. */
4492 0 : ++middle;
4493 0 : e.index = dindex;
4494 0 : e.value = unshare_constructor (value);
4495 0 : vec_safe_insert (CONSTRUCTOR_ELTS (ary), middle, e);
4496 : }
4497 : else
4498 : /* No lower elts, the range elt is now ours. */
4499 0 : elt.index = dindex;
4500 :
4501 0 : if (tree_int_cst_lt (dindex, hi))
4502 : {
4503 : /* There are still some higher elts; append a range. */
4504 0 : tree new_lo
4505 0 : = int_const_binop (PLUS_EXPR, dindex, size_one_node);
4506 0 : if (tree_int_cst_equal (new_lo, hi))
4507 0 : e.index = hi;
4508 : else
4509 0 : e.index = build2 (RANGE_EXPR, sizetype, new_lo, hi);
4510 0 : e.value = unshare_constructor (value);
4511 0 : vec_safe_insert (CONSTRUCTOR_ELTS (ary), middle + 1, e);
4512 : }
4513 : }
4514 0 : return middle;
4515 : }
4516 : }
4517 :
4518 0 : if (insert)
4519 : {
4520 0 : constructor_elt e = {dindex, NULL_TREE};
4521 0 : vec_safe_insert (CONSTRUCTOR_ELTS (ary), end, e);
4522 0 : return end;
4523 : }
4524 :
4525 : return -1;
4526 : }
4527 :
4528 : /* Some expressions may have constant operands but are not constant
4529 : themselves, such as 1/0. Call this function to check for that
4530 : condition.
4531 :
4532 : We only call this in places that require an arithmetic constant, not in
4533 : places where we might have a non-constant expression that can be a
4534 : component of a constant expression, such as the address of a constexpr
4535 : variable that might be dereferenced later. */
4536 :
4537 : static bool
4538 262243 : verify_constant (tree t, bool allow_non_constant, bool *non_constant_p,
4539 : bool *overflow_p)
4540 : {
4541 262243 : if (!*non_constant_p && !reduced_constant_expression_p (t) && t != void_node)
4542 : {
4543 2 : if (!allow_non_constant)
4544 2 : error_at (EXPR_LOCATION (t), "is not a constant expression");
4545 2 : *non_constant_p = true;
4546 : }
4547 262243 : if (TREE_OVERFLOW_P (t))
4548 : {
4549 0 : if (!allow_non_constant)
4550 : {
4551 0 : permerror (input_location, "overflow in constant expression");
4552 : /* If we're being permissive (and are in an enforcing
4553 : context), ignore the overflow. */
4554 0 : if (flag_permissive)
4555 0 : return *non_constant_p;
4556 : }
4557 0 : *overflow_p = true;
4558 : }
4559 262243 : return *non_constant_p;
4560 : }
4561 :
4562 : // forked from gcc/cp/constexpr.cc find_heap_var_refs
4563 :
4564 : /* Look for heap variables in the expression *TP. */
4565 :
4566 : static tree
4567 0 : find_heap_var_refs (tree *tp, int *walk_subtrees, void * /*data*/)
4568 : {
4569 0 : if (VAR_P (*tp)
4570 0 : && (DECL_NAME (*tp) == heap_uninit_identifier
4571 0 : || DECL_NAME (*tp) == heap_identifier
4572 0 : || DECL_NAME (*tp) == heap_vec_uninit_identifier
4573 0 : || DECL_NAME (*tp) == heap_vec_identifier
4574 0 : || DECL_NAME (*tp) == heap_deleted_identifier))
4575 : return *tp;
4576 :
4577 0 : if (TYPE_P (*tp))
4578 0 : *walk_subtrees = 0;
4579 : return NULL_TREE;
4580 : }
4581 :
4582 : // forked from gcc/cp/constexpr.cc find_immediate_fndecl
4583 :
4584 : /* Find immediate function decls in *TP if any. */
4585 :
4586 : static tree
4587 0 : find_immediate_fndecl (tree *tp, int * /*walk_subtrees*/, void * /*data*/)
4588 : {
4589 0 : if (TREE_CODE (*tp) == FUNCTION_DECL && DECL_IMMEDIATE_FUNCTION_P (*tp))
4590 : return *tp;
4591 0 : if (TREE_CODE (*tp) == PTRMEM_CST
4592 0 : && TREE_CODE (PTRMEM_CST_MEMBER (*tp)) == FUNCTION_DECL
4593 0 : && DECL_IMMEDIATE_FUNCTION_P (PTRMEM_CST_MEMBER (*tp)))
4594 : return PTRMEM_CST_MEMBER (*tp);
4595 : return NULL_TREE;
4596 : }
4597 :
4598 : // forked in gcc/cp/constexpr.cc diag_array_subscript
4599 :
4600 : /* Under the control of CTX, issue a detailed diagnostic for
4601 : an out-of-bounds subscript INDEX into the expression ARRAY. */
4602 :
4603 : static void
4604 1 : diag_array_subscript (location_t loc, const constexpr_ctx *ctx, tree array,
4605 : tree index)
4606 : {
4607 1 : if (!ctx->quiet)
4608 : {
4609 1 : tree arraytype = TREE_TYPE (array);
4610 :
4611 : /* Convert the unsigned array subscript to a signed integer to avoid
4612 : printing huge numbers for small negative values. */
4613 1 : tree sidx = fold_convert (ssizetype, index);
4614 1 : STRIP_ANY_LOCATION_WRAPPER (array);
4615 1 : if (DECL_P (array))
4616 : {
4617 1 : if (TYPE_DOMAIN (arraytype))
4618 1 : error_at (loc,
4619 : "array subscript value %qE is outside the bounds "
4620 : "of array %qD of type %qT",
4621 : sidx, array, arraytype);
4622 : else
4623 0 : error_at (loc,
4624 : "nonzero array subscript %qE is used with array %qD of "
4625 : "type %qT with unknown bounds",
4626 : sidx, array, arraytype);
4627 1 : inform (DECL_SOURCE_LOCATION (array), "declared here");
4628 : }
4629 0 : else if (TYPE_DOMAIN (arraytype))
4630 0 : error_at (loc,
4631 : "array subscript value %qE is outside the bounds "
4632 : "of array type %qT",
4633 : sidx, arraytype);
4634 : else
4635 0 : error_at (loc,
4636 : "nonzero array subscript %qE is used with array of type %qT "
4637 : "with unknown bounds",
4638 : sidx, arraytype);
4639 : }
4640 1 : }
4641 :
4642 : // forked from gcc/cp/constexpr.cc get_array_or_vector_nelts
4643 :
4644 : /* Return the number of elements for TYPE (which is an ARRAY_TYPE or
4645 : a VECTOR_TYPE). */
4646 :
4647 : static tree
4648 10 : get_array_or_vector_nelts (const constexpr_ctx *ctx, tree type,
4649 : bool *non_constant_p, bool *overflow_p,
4650 : tree *jump_target)
4651 : {
4652 10 : tree nelts;
4653 10 : if (TREE_CODE (type) == ARRAY_TYPE)
4654 : {
4655 10 : if (TYPE_DOMAIN (type))
4656 10 : nelts = array_type_nelts_top (type);
4657 : else
4658 0 : nelts = size_zero_node;
4659 : }
4660 0 : else if (VECTOR_TYPE_P (type))
4661 0 : nelts = size_int (TYPE_VECTOR_SUBPARTS (type));
4662 : else
4663 0 : rust_unreachable ();
4664 :
4665 : /* For VLAs, the number of elements won't be an integer constant. */
4666 10 : nelts = eval_constant_expression (ctx, nelts, false, non_constant_p,
4667 : overflow_p, jump_target);
4668 10 : return nelts;
4669 : }
4670 :
4671 : // forked from gcc/cp/constexpr.cc eval_and_check_array_index
4672 :
4673 : /* Subroutine of cxx_eval_array_reference. T is an ARRAY_REF; evaluate the
4674 : subscript, diagnose any problems with it, and return the result. */
4675 :
4676 : static tree
4677 10 : eval_and_check_array_index (const constexpr_ctx *ctx, tree t,
4678 : bool allow_one_past, bool *non_constant_p,
4679 : bool *overflow_p, tree *jump_target)
4680 : {
4681 10 : location_t loc = rs_expr_loc_or_input_loc (t);
4682 10 : tree ary = TREE_OPERAND (t, 0);
4683 10 : t = TREE_OPERAND (t, 1);
4684 10 : tree index = eval_constant_expression (ctx, t, allow_one_past, non_constant_p,
4685 : overflow_p, jump_target);
4686 10 : VERIFY_CONSTANT (index);
4687 :
4688 10 : if (!tree_fits_shwi_p (index) || tree_int_cst_sgn (index) < 0)
4689 : {
4690 0 : diag_array_subscript (loc, ctx, ary, index);
4691 0 : *non_constant_p = true;
4692 0 : return t;
4693 : }
4694 :
4695 10 : tree nelts = get_array_or_vector_nelts (ctx, TREE_TYPE (ary), non_constant_p,
4696 : overflow_p, jump_target);
4697 10 : VERIFY_CONSTANT (nelts);
4698 20 : if (allow_one_past ? !tree_int_cst_le (index, nelts)
4699 10 : : !tree_int_cst_lt (index, nelts))
4700 : {
4701 1 : diag_array_subscript (loc, ctx, ary, index);
4702 1 : *non_constant_p = true;
4703 1 : return t;
4704 : }
4705 :
4706 : return index;
4707 : }
4708 :
4709 : // forked from gcc/cp/constexpr.cc extract_string_elt
4710 :
4711 : /* Extract element INDEX consisting of CHARS_PER_ELT chars from
4712 : STRING_CST STRING. */
4713 :
4714 : static tree
4715 0 : extract_string_elt (tree string, unsigned chars_per_elt, unsigned index)
4716 : {
4717 0 : tree type = cv_unqualified (TREE_TYPE (TREE_TYPE (string)));
4718 0 : tree r;
4719 :
4720 0 : if (chars_per_elt == 1)
4721 0 : r = build_int_cst (type, TREE_STRING_POINTER (string)[index]);
4722 : else
4723 : {
4724 0 : const unsigned char *ptr
4725 0 : = ((const unsigned char *) TREE_STRING_POINTER (string)
4726 0 : + index * chars_per_elt);
4727 0 : r = native_interpret_expr (type, ptr, chars_per_elt);
4728 : }
4729 0 : return r;
4730 : }
4731 :
4732 : /* Check whether the parameter and return types of FUN are valid for a
4733 : constexpr function, and complain if COMPLAIN. */
4734 :
4735 : bool
4736 0 : is_valid_constexpr_fn (tree fun, bool complain)
4737 : {
4738 0 : bool ret = true;
4739 :
4740 0 : for (tree parm = FUNCTION_FIRST_USER_PARM (fun); parm != NULL_TREE;
4741 0 : parm = TREE_CHAIN (parm))
4742 0 : if (!literal_type_p (TREE_TYPE (parm)))
4743 : {
4744 0 : ret = false;
4745 0 : if (complain)
4746 : {
4747 : // auto_diagnostic_group d;
4748 : // error ("invalid type for parameter %d of %<constexpr%> "
4749 : // "function %q+#D",
4750 : // DECL_PARM_INDEX (parm), fun);
4751 0 : location_t locus = DECL_SOURCE_LOCATION (fun);
4752 0 : rust_error_at (
4753 : locus, "invalid type for parameter %d of %<constexpr%> function",
4754 0 : DECL_PARM_INDEX (parm));
4755 : }
4756 : }
4757 :
4758 0 : return ret;
4759 : }
4760 :
4761 : void
4762 0 : explain_invalid_constexpr_fn (tree fun)
4763 : {
4764 0 : static hash_set<tree> *diagnosed;
4765 : // tree body;
4766 :
4767 0 : if (diagnosed == NULL)
4768 0 : diagnosed = new hash_set<tree>;
4769 0 : if (diagnosed->add (fun))
4770 : /* Already explained. */
4771 0 : return;
4772 :
4773 0 : iloc_sentinel ils = input_location;
4774 : // if (!lambda_static_thunk_p (fun))
4775 : // {
4776 : // /* Diagnostics should completely ignore the static thunk, so leave
4777 : // input_location set to our caller's location. */
4778 : // input_location = DECL_SOURCE_LOCATION (fun);
4779 : // inform (input_location,
4780 : // "%qD is not usable as a %<constexpr%> function because:",
4781 : // fun);
4782 : // }
4783 :
4784 : /* First check the declaration. */
4785 0 : if (is_valid_constexpr_fn (fun, true))
4786 : {
4787 : // /* Then if it's OK, the body. */
4788 : // if (!DECL_DECLARED_CONSTEXPR_P (fun))
4789 : // explain_implicit_non_constexpr (fun);
4790 : // else
4791 : // {
4792 : // if (constexpr_fundef *fd = retrieve_constexpr_fundef (fun))
4793 : // body = fd->body;
4794 : // else
4795 : // body = DECL_SAVED_TREE (fun);
4796 : // body = massage_constexpr_body (fun, body);
4797 : // require_potential_rvalue_constant_expression (body);
4798 : // }
4799 : }
4800 0 : }
4801 :
4802 : /* BODY is a validated and massaged definition of a constexpr
4803 : function. Register it in the hash table. */
4804 :
4805 : void
4806 4575 : register_constexpr_fundef (const rust_constexpr_fundef &value)
4807 : {
4808 : /* Create the constexpr function table if necessary. */
4809 4575 : if (constexpr_fundef_table == NULL)
4810 746 : constexpr_fundef_table
4811 746 : = hash_table<rust_constexpr_fundef_hasher>::create_ggc (101);
4812 :
4813 9150 : rust_constexpr_fundef **slot = constexpr_fundef_table->find_slot (
4814 4575 : const_cast<rust_constexpr_fundef *> (&value), INSERT);
4815 :
4816 4575 : gcc_assert (*slot == NULL);
4817 4575 : *slot = ggc_alloc<rust_constexpr_fundef> ();
4818 4575 : **slot = value;
4819 4575 : }
4820 :
4821 : /* We are processing the definition of the constexpr function FUN.
4822 : Check that its body fulfills the apropriate requirements and
4823 : enter it in the constexpr function definition table. */
4824 :
4825 : void
4826 4575 : maybe_save_constexpr_fundef (tree fun)
4827 : {
4828 : // FIXME
4829 :
4830 4575 : rust_constexpr_fundef entry = {fun, NULL_TREE, NULL_TREE, NULL_TREE};
4831 4575 : bool clear_ctx = false;
4832 4575 : if (DECL_RESULT (fun) && DECL_CONTEXT (DECL_RESULT (fun)) == NULL_TREE)
4833 : {
4834 0 : clear_ctx = true;
4835 0 : DECL_CONTEXT (DECL_RESULT (fun)) = fun;
4836 : }
4837 4575 : tree saved_fn = current_function_decl;
4838 4575 : current_function_decl = fun;
4839 4575 : entry.body = copy_fn (entry.decl, entry.parms, entry.result);
4840 4575 : current_function_decl = saved_fn;
4841 4575 : if (clear_ctx)
4842 0 : DECL_CONTEXT (DECL_RESULT (entry.decl)) = NULL_TREE;
4843 :
4844 4575 : register_constexpr_fundef (entry);
4845 4575 : }
4846 :
4847 : /* Evaluate a STATEMENT_LIST for side-effects. Handles various jump
4848 : semantics, for switch, break, continue, and return. */
4849 :
4850 : static tree
4851 264281 : eval_statement_list (const constexpr_ctx *ctx, tree t, bool *non_constant_p,
4852 : bool *overflow_p, tree *jump_target)
4853 : {
4854 264281 : tree local_target;
4855 : /* In a statement-expression we want to return the last value.
4856 : For empty statement expression return void_node. */
4857 264281 : tree r = void_node;
4858 264281 : if (!jump_target)
4859 : {
4860 0 : local_target = NULL_TREE;
4861 0 : jump_target = &local_target;
4862 : }
4863 1052577 : for (tree stmt : tsi_range (t))
4864 : {
4865 : /* We've found a continue, so skip everything until we reach
4866 : the label its jumping to. */
4867 790402 : if (continues (jump_target))
4868 : {
4869 0 : if (label_matches (ctx, jump_target, stmt))
4870 : /* Found it. */
4871 0 : *jump_target = NULL_TREE;
4872 : else
4873 0 : continue;
4874 : }
4875 790402 : if (TREE_CODE (stmt) == DEBUG_BEGIN_STMT)
4876 0 : continue;
4877 790402 : r = eval_constant_expression (ctx, stmt, false, non_constant_p,
4878 : overflow_p, jump_target);
4879 790402 : if (*non_constant_p)
4880 : break;
4881 790396 : if (returns (jump_target) || breaks (jump_target))
4882 : break;
4883 : }
4884 264281 : if (*jump_target && jump_target == &local_target)
4885 : {
4886 : /* We aren't communicating the jump to our caller, so give up. We don't
4887 : need to support evaluation of jumps out of statement-exprs. */
4888 0 : if (!ctx->quiet)
4889 0 : error_at (EXPR_LOCATION (r), "statement is not a constant expression");
4890 0 : *non_constant_p = true;
4891 : }
4892 264281 : return r;
4893 : }
4894 :
4895 : // forked from gcc/cp/constexpr.cc cxx_eval_conditional_expression
4896 :
4897 : /* Subroutine of cxx_eval_constant_expression.
4898 : Attempt to evaluate condition expressions. Dead branches are not
4899 : looked into. */
4900 :
4901 : static tree
4902 16 : eval_conditional_expression (const constexpr_ctx *ctx, tree t, bool lval,
4903 : bool *non_constant_p, bool *overflow_p,
4904 : tree *jump_target)
4905 : {
4906 16 : tree val = eval_constant_expression (ctx, TREE_OPERAND (t, 0),
4907 : /*lval*/ false, non_constant_p,
4908 : overflow_p, jump_target);
4909 16 : VERIFY_CONSTANT (val);
4910 16 : if (TREE_CODE (t) == IF_STMT && IF_STMT_CONSTEVAL_P (t))
4911 : {
4912 : /* Evaluate the condition as if it was
4913 : if (__builtin_is_constant_evaluated ()), i.e. defer it if not
4914 : ctx->manifestly_const_eval (as sometimes we try to constant evaluate
4915 : without manifestly_const_eval even expressions or parts thereof which
4916 : will later be manifestly const_eval evaluated), otherwise fold it to
4917 : true. */
4918 0 : if (ctx->manifestly_const_eval)
4919 0 : val = boolean_true_node;
4920 : else
4921 : {
4922 0 : *non_constant_p = true;
4923 0 : return t;
4924 : }
4925 : }
4926 : /* Don't VERIFY_CONSTANT the other operands. */
4927 16 : if (integer_zerop (val))
4928 12 : val = TREE_OPERAND (t, 2);
4929 : else
4930 4 : val = TREE_OPERAND (t, 1);
4931 16 : if (/*TREE_CODE (t) == IF_STMT && */ !val)
4932 11 : val = void_node;
4933 16 : return eval_constant_expression (ctx, val, lval, non_constant_p, overflow_p,
4934 16 : jump_target);
4935 : }
4936 :
4937 : // forked from gcc/cp/constexpr.cc cxx_eval_bit_field_ref
4938 :
4939 : /* Subroutine of cxx_eval_constant_expression.
4940 : Attempt to reduce a field access of a value of class type that is
4941 : expressed as a BIT_FIELD_REF. */
4942 :
4943 : static tree
4944 0 : eval_bit_field_ref (const constexpr_ctx *ctx, tree t, bool lval,
4945 : bool *non_constant_p, bool *overflow_p, tree *jump_target)
4946 : {
4947 0 : tree orig_whole = TREE_OPERAND (t, 0);
4948 0 : tree retval, fldval, utype, mask;
4949 0 : bool fld_seen = false;
4950 0 : HOST_WIDE_INT istart, isize;
4951 0 : tree whole = eval_constant_expression (ctx, orig_whole, lval, non_constant_p,
4952 : overflow_p, jump_target);
4953 0 : tree start, field, value;
4954 0 : unsigned HOST_WIDE_INT i;
4955 :
4956 0 : if (whole == orig_whole)
4957 : return t;
4958 : /* Don't VERIFY_CONSTANT here; we only want to check that we got a
4959 : CONSTRUCTOR. */
4960 0 : if (!*non_constant_p && TREE_CODE (whole) != VECTOR_CST
4961 0 : && TREE_CODE (whole) != CONSTRUCTOR)
4962 : {
4963 0 : if (!ctx->quiet)
4964 0 : error ("%qE is not a constant expression", orig_whole);
4965 0 : *non_constant_p = true;
4966 : }
4967 0 : if (*non_constant_p)
4968 : return t;
4969 :
4970 0 : if (TREE_CODE (whole) == VECTOR_CST)
4971 0 : return fold_ternary (BIT_FIELD_REF, TREE_TYPE (t), whole,
4972 : TREE_OPERAND (t, 1), TREE_OPERAND (t, 2));
4973 :
4974 0 : start = TREE_OPERAND (t, 2);
4975 0 : istart = tree_to_shwi (start);
4976 0 : isize = tree_to_shwi (TREE_OPERAND (t, 1));
4977 0 : utype = TREE_TYPE (t);
4978 0 : if (!TYPE_UNSIGNED (utype))
4979 0 : utype = build_nonstandard_integer_type (TYPE_PRECISION (utype), 1);
4980 0 : retval = build_int_cst (utype, 0);
4981 0 : FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (whole), i, field, value)
4982 : {
4983 0 : tree bitpos = bit_position (field);
4984 0 : STRIP_ANY_LOCATION_WRAPPER (value);
4985 0 : if (bitpos == start && DECL_SIZE (field) == TREE_OPERAND (t, 1))
4986 : return value;
4987 0 : if (TREE_CODE (TREE_TYPE (field)) == INTEGER_TYPE
4988 0 : && TREE_CODE (value) == INTEGER_CST && tree_fits_shwi_p (bitpos)
4989 0 : && tree_fits_shwi_p (DECL_SIZE (field)))
4990 : {
4991 0 : HOST_WIDE_INT bit = tree_to_shwi (bitpos);
4992 0 : HOST_WIDE_INT sz = tree_to_shwi (DECL_SIZE (field));
4993 0 : HOST_WIDE_INT shift;
4994 0 : if (bit >= istart && bit + sz <= istart + isize)
4995 : {
4996 0 : fldval = fold_convert (utype, value);
4997 0 : mask = build_int_cst_type (utype, -1);
4998 0 : mask = fold_build2 (LSHIFT_EXPR, utype, mask,
4999 : size_int (TYPE_PRECISION (utype) - sz));
5000 0 : mask = fold_build2 (RSHIFT_EXPR, utype, mask,
5001 : size_int (TYPE_PRECISION (utype) - sz));
5002 0 : fldval = fold_build2 (BIT_AND_EXPR, utype, fldval, mask);
5003 0 : shift = bit - istart;
5004 0 : if (BYTES_BIG_ENDIAN)
5005 : shift = TYPE_PRECISION (utype) - shift - sz;
5006 0 : fldval
5007 0 : = fold_build2 (LSHIFT_EXPR, utype, fldval, size_int (shift));
5008 0 : retval = fold_build2 (BIT_IOR_EXPR, utype, retval, fldval);
5009 0 : fld_seen = true;
5010 : }
5011 : }
5012 : }
5013 0 : if (fld_seen)
5014 0 : return fold_convert (TREE_TYPE (t), retval);
5015 0 : rust_unreachable ();
5016 : return error_mark_node;
5017 : }
5018 :
5019 : // forked from gcc/cp/constexpr.cc returns
5020 :
5021 : /* Predicates for the meaning of *jump_target. */
5022 :
5023 : static bool
5024 1052549 : returns (tree *jump_target)
5025 : {
5026 1052549 : return *jump_target
5027 1052549 : && (TREE_CODE (*jump_target) == RETURN_EXPR
5028 6 : || (TREE_CODE (*jump_target) == LABEL_DECL
5029 0 : && LABEL_DECL_CDTOR (*jump_target)));
5030 : }
5031 :
5032 : // forked from gcc/cp/constexpr.cc breaks
5033 :
5034 : static bool
5035 1312612 : breaks (tree *jump_target)
5036 : {
5037 1312612 : return *jump_target
5038 1312612 : && ((TREE_CODE (*jump_target) == LABEL_DECL
5039 0 : && LABEL_DECL_BREAK (*jump_target))
5040 9 : || TREE_CODE (*jump_target) == BREAK_STMT
5041 9 : || TREE_CODE (*jump_target) == EXIT_EXPR);
5042 : }
5043 :
5044 : // forked from gcc/cp/constexpr.cc continues
5045 :
5046 : static bool
5047 1052555 : continues (tree *jump_target)
5048 : {
5049 1052555 : return *jump_target
5050 1052555 : && ((TREE_CODE (*jump_target) == LABEL_DECL
5051 0 : && LABEL_DECL_CONTINUE (*jump_target))
5052 0 : || TREE_CODE (*jump_target) == CONTINUE_STMT);
5053 : }
5054 :
5055 : // forked from gcc/cp/constexpr.cc switches
5056 :
5057 : static bool
5058 262153 : switches (tree *jump_target)
5059 : {
5060 262153 : return *jump_target && TREE_CODE (*jump_target) == INTEGER_CST;
5061 : }
5062 :
5063 : // forked from gcc/cp/constexpr.cc cxx_eval_loop_expr
5064 :
5065 : /* Evaluate a LOOP_EXPR for side-effects. Handles break and return
5066 : semantics; continue semantics are covered by cxx_eval_statement_list. */
5067 :
5068 : static tree
5069 4 : eval_loop_expr (const constexpr_ctx *ctx, tree t, bool *non_constant_p,
5070 : bool *overflow_p, tree *jump_target)
5071 : {
5072 4 : constexpr_ctx new_ctx = *ctx;
5073 4 : tree local_target;
5074 4 : if (!jump_target)
5075 : {
5076 0 : local_target = NULL_TREE;
5077 0 : jump_target = &local_target;
5078 : }
5079 :
5080 4 : tree body, cond = NULL_TREE, expr = NULL_TREE;
5081 4 : int count = 0;
5082 4 : switch (TREE_CODE (t))
5083 : {
5084 4 : case LOOP_EXPR:
5085 4 : body = LOOP_EXPR_BODY (t);
5086 4 : break;
5087 0 : case WHILE_STMT:
5088 0 : body = WHILE_BODY (t);
5089 0 : cond = WHILE_COND (t);
5090 0 : count = -1;
5091 0 : break;
5092 0 : case FOR_STMT:
5093 0 : if (FOR_INIT_STMT (t))
5094 0 : eval_constant_expression (ctx, FOR_INIT_STMT (t), /*lval*/ false,
5095 : non_constant_p, overflow_p, jump_target);
5096 0 : if (*non_constant_p)
5097 : return NULL_TREE;
5098 0 : body = FOR_BODY (t);
5099 0 : cond = FOR_COND (t);
5100 0 : expr = FOR_EXPR (t);
5101 0 : count = -1;
5102 0 : break;
5103 0 : default:
5104 0 : rust_unreachable ();
5105 : }
5106 8 : auto_vec<tree, 10> save_exprs;
5107 4 : new_ctx.save_exprs = &save_exprs;
5108 262157 : do
5109 : {
5110 262157 : if (count != -1)
5111 : {
5112 262157 : if (body)
5113 262157 : eval_constant_expression (&new_ctx, body, /*lval*/ false,
5114 : non_constant_p, overflow_p, jump_target);
5115 262157 : if (breaks (jump_target))
5116 : {
5117 3 : *jump_target = NULL_TREE;
5118 3 : break;
5119 : }
5120 :
5121 262154 : if (TREE_CODE (t) != LOOP_EXPR && continues (jump_target))
5122 0 : *jump_target = NULL_TREE;
5123 :
5124 262154 : if (expr)
5125 0 : eval_constant_expression (&new_ctx, expr, /*lval*/ false,
5126 : non_constant_p, overflow_p, jump_target);
5127 : }
5128 :
5129 262154 : if (cond)
5130 : {
5131 0 : tree res = eval_constant_expression (&new_ctx, cond, /*lval*/ false,
5132 : non_constant_p, overflow_p,
5133 : jump_target);
5134 0 : if (res)
5135 : {
5136 0 : if (verify_constant (res, ctx->quiet, non_constant_p, overflow_p))
5137 : break;
5138 0 : if (integer_zerop (res))
5139 : break;
5140 : }
5141 : else
5142 0 : gcc_assert (*jump_target);
5143 : }
5144 :
5145 : /* Forget saved values of SAVE_EXPRs and TARGET_EXPRs. */
5146 786462 : for (tree save_expr : save_exprs)
5147 0 : ctx->global->values.remove (save_expr);
5148 262154 : save_exprs.truncate (0);
5149 :
5150 262154 : if (++count >= constexpr_loop_limit)
5151 : {
5152 1 : if (!ctx->quiet)
5153 2 : error_at (rs_expr_loc_or_input_loc (t),
5154 : "%<constexpr%> loop iteration count exceeds limit of %d "
5155 : "(use %<-fconstexpr-loop-limit=%> to increase the limit)",
5156 : constexpr_loop_limit);
5157 1 : *non_constant_p = true;
5158 1 : break;
5159 : }
5160 : }
5161 262153 : while (!returns (jump_target) && !breaks (jump_target)
5162 262153 : && !continues (jump_target) && (!switches (jump_target) || count == 0)
5163 524306 : && !*non_constant_p);
5164 :
5165 : /* Forget saved values of SAVE_EXPRs and TARGET_EXPRs. */
5166 12 : for (tree save_expr : save_exprs)
5167 0 : ctx->global->values.remove (save_expr);
5168 :
5169 4 : return NULL_TREE;
5170 : }
5171 :
5172 : // forked from gcc/cp/constexpr.cc cxx_eval_switch_expr
5173 :
5174 : /* Evaluate a SWITCH_EXPR for side-effects. Handles switch and break jump
5175 : semantics. */
5176 :
5177 : static tree
5178 0 : eval_switch_expr (const constexpr_ctx *ctx, tree t, bool *non_constant_p,
5179 : bool *overflow_p, tree *jump_target)
5180 : {
5181 0 : tree cond
5182 0 : = TREE_CODE (t) == SWITCH_STMT ? SWITCH_STMT_COND (t) : SWITCH_COND (t);
5183 0 : cond = eval_constant_expression (ctx, cond, false, non_constant_p, overflow_p,
5184 : jump_target);
5185 0 : VERIFY_CONSTANT (cond);
5186 0 : *jump_target = cond;
5187 :
5188 0 : tree body
5189 0 : = TREE_CODE (t) == SWITCH_STMT ? SWITCH_STMT_BODY (t) : SWITCH_BODY (t);
5190 0 : constexpr_ctx new_ctx = *ctx;
5191 0 : constexpr_switch_state css = css_default_not_seen;
5192 0 : new_ctx.css_state = &css;
5193 0 : eval_constant_expression (&new_ctx, body, false, non_constant_p, overflow_p,
5194 : jump_target);
5195 0 : if (switches (jump_target) && css == css_default_seen)
5196 : {
5197 : /* If the SWITCH_EXPR body has default: label, process it once again,
5198 : this time instructing label_matches to return true for default:
5199 : label on switches (jump_target). */
5200 0 : css = css_default_processing;
5201 0 : eval_constant_expression (&new_ctx, body, false, non_constant_p,
5202 : overflow_p, jump_target);
5203 : }
5204 0 : if (breaks (jump_target) || switches (jump_target))
5205 0 : *jump_target = NULL_TREE;
5206 : return NULL_TREE;
5207 : }
5208 :
5209 : // forked from gcc/cp/constexpr.cc eval_unary_expression
5210 :
5211 : /* Subroutine of cxx_eval_constant_expression.
5212 : Attempt to reduce the unary expression tree T to a compile time value.
5213 : If successful, return the value. Otherwise issue a diagnostic
5214 : and return error_mark_node. */
5215 :
5216 : static tree
5217 7 : eval_unary_expression (const constexpr_ctx *ctx, tree t, bool /*lval*/,
5218 : bool *non_constant_p, bool *overflow_p,
5219 : tree *jump_target)
5220 : {
5221 7 : tree r;
5222 7 : tree orig_arg = TREE_OPERAND (t, 0);
5223 7 : tree arg = eval_constant_expression (ctx, orig_arg, /*lval*/ false,
5224 : non_constant_p, overflow_p, jump_target);
5225 7 : VERIFY_CONSTANT (arg);
5226 7 : location_t loc = EXPR_LOCATION (t);
5227 7 : enum tree_code code = TREE_CODE (t);
5228 7 : tree type = TREE_TYPE (t);
5229 7 : r = fold_unary_loc (loc, code, type, arg);
5230 7 : if (r == NULL_TREE)
5231 : {
5232 0 : if (arg == orig_arg)
5233 : r = t;
5234 : else
5235 0 : r = build1_loc (loc, code, type, arg);
5236 : }
5237 7 : VERIFY_CONSTANT (r);
5238 : return r;
5239 : }
5240 :
5241 : // forked from gcc/cp/constexpr.cc cxx_eval_outermost_constant_expr
5242 :
5243 : /* ALLOW_NON_CONSTANT is false if T is required to be a constant expression.
5244 : STRICT has the same sense as for constant_value_1: true if we only allow
5245 : conforming C++ constant expressions, or false if we want a constant value
5246 : even if it doesn't conform.
5247 : MANIFESTLY_CONST_EVAL is true if T is manifestly const-evaluated as
5248 : per P0595 even when ALLOW_NON_CONSTANT is true.
5249 : CONSTEXPR_DTOR is true when evaluating the dtor of a constexpr variable.
5250 : OBJECT must be non-NULL in that case. */
5251 :
5252 : static tree
5253 0 : cxx_eval_outermost_constant_expr (tree t, bool allow_non_constant,
5254 : bool strict = true,
5255 : bool manifestly_const_eval = false,
5256 : bool constexpr_dtor = false,
5257 : tree object = NULL_TREE)
5258 : {
5259 0 : auto_timevar time (TV_CONSTEXPR);
5260 :
5261 0 : bool non_constant_p = false;
5262 0 : bool overflow_p = false;
5263 :
5264 0 : if (BRACE_ENCLOSED_INITIALIZER_P (t))
5265 : {
5266 0 : gcc_checking_assert (allow_non_constant);
5267 : return t;
5268 : }
5269 :
5270 0 : constexpr_global_ctx global_ctx;
5271 0 : constexpr_ctx ctx
5272 : = {&global_ctx, NULL,
5273 : NULL, NULL,
5274 : NULL, NULL,
5275 : NULL, allow_non_constant,
5276 0 : strict, manifestly_const_eval || !allow_non_constant};
5277 :
5278 : /* Turn off -frounding-math for manifestly constant evaluation. */
5279 0 : warning_sentinel rm (flag_rounding_math, ctx.manifestly_const_eval);
5280 0 : tree type = initialized_type (t);
5281 0 : tree r = t;
5282 0 : bool is_consteval = false;
5283 0 : if (VOID_TYPE_P (type))
5284 : {
5285 0 : if (constexpr_dtor)
5286 : /* Used for destructors of array elements. */
5287 0 : type = TREE_TYPE (object);
5288 : else
5289 : {
5290 0 : if (TREE_CODE (t) != CALL_EXPR)
5291 : return t;
5292 : /* Calls to immediate functions returning void need to be
5293 : evaluated. */
5294 0 : tree fndecl = rs_get_callee_fndecl_nofold (t);
5295 0 : if (fndecl == NULL_TREE || !DECL_IMMEDIATE_FUNCTION_P (fndecl))
5296 : return t;
5297 : else
5298 : is_consteval = true;
5299 : }
5300 : }
5301 0 : else if ((TREE_CODE (t) == CALL_EXPR || TREE_CODE (t) == TARGET_EXPR))
5302 : {
5303 : /* For non-concept checks, determine if it is consteval. */
5304 0 : tree x = t;
5305 0 : if (TREE_CODE (x) == TARGET_EXPR)
5306 0 : x = TARGET_EXPR_INITIAL (x);
5307 0 : tree fndecl = rs_get_callee_fndecl_nofold (x);
5308 0 : if (fndecl && DECL_IMMEDIATE_FUNCTION_P (fndecl))
5309 : is_consteval = true;
5310 : }
5311 0 : if (AGGREGATE_TYPE_P (type) || VECTOR_TYPE_P (type))
5312 : {
5313 : /* In C++14 an NSDMI can participate in aggregate initialization,
5314 : and can refer to the address of the object being initialized, so
5315 : we need to pass in the relevant VAR_DECL if we want to do the
5316 : evaluation in a single pass. The evaluation will dynamically
5317 : update ctx.values for the VAR_DECL. We use the same strategy
5318 : for C++11 constexpr constructors that refer to the object being
5319 : initialized. */
5320 0 : if (constexpr_dtor)
5321 : {
5322 0 : gcc_assert (object && VAR_P (object));
5323 0 : gcc_assert (DECL_DECLARED_CONSTEXPR_P (object));
5324 0 : gcc_assert (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (object));
5325 0 : if (error_operand_p (DECL_INITIAL (object)))
5326 : return t;
5327 0 : ctx.ctor = unshare_expr (DECL_INITIAL (object));
5328 0 : TREE_READONLY (ctx.ctor) = false;
5329 : /* Temporarily force decl_really_constant_value to return false
5330 : for it, we want to use ctx.ctor for the current value instead. */
5331 0 : DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (object) = false;
5332 : }
5333 : else
5334 : {
5335 0 : ctx.ctor = build_constructor (type, NULL);
5336 0 : CONSTRUCTOR_NO_CLEARING (ctx.ctor) = true;
5337 : }
5338 0 : if (!object)
5339 : {
5340 0 : if (TREE_CODE (t) == TARGET_EXPR)
5341 0 : object = TARGET_EXPR_SLOT (t);
5342 : }
5343 0 : ctx.object = object;
5344 0 : if (object)
5345 0 : gcc_assert (
5346 : same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (object)));
5347 0 : if (object && DECL_P (object))
5348 0 : global_ctx.values.put (object, ctx.ctor);
5349 0 : if (TREE_CODE (r) == TARGET_EXPR)
5350 : /* Avoid creating another CONSTRUCTOR when we expand the
5351 : TARGET_EXPR. */
5352 0 : r = TARGET_EXPR_INITIAL (r);
5353 : }
5354 :
5355 0 : auto_vec<tree, 16> cleanups;
5356 0 : global_ctx.cleanups = &cleanups;
5357 :
5358 0 : if (manifestly_const_eval)
5359 0 : instantiate_constexpr_fns (r);
5360 0 : tree jump_target = NULL_TREE;
5361 0 : r = eval_constant_expression (&ctx, r, false, &non_constant_p, &overflow_p,
5362 : &jump_target);
5363 :
5364 0 : if (!constexpr_dtor)
5365 0 : verify_constant (r, allow_non_constant, &non_constant_p, &overflow_p);
5366 : else
5367 0 : DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (object) = true;
5368 :
5369 0 : unsigned int i;
5370 0 : tree cleanup;
5371 : /* Evaluate the cleanups. */
5372 0 : FOR_EACH_VEC_ELT_REVERSE (cleanups, i, cleanup)
5373 0 : eval_constant_expression (&ctx, cleanup, false, &non_constant_p,
5374 : &overflow_p, NULL);
5375 :
5376 : /* Mutable logic is a bit tricky: we want to allow initialization of
5377 : constexpr variables with mutable members, but we can't copy those
5378 : members to another constexpr variable. */
5379 0 : if (TREE_CODE (r) == CONSTRUCTOR && CONSTRUCTOR_MUTABLE_POISON (r))
5380 : {
5381 0 : if (!allow_non_constant)
5382 0 : error ("%qE is not a constant expression because it refers to "
5383 : "mutable subobjects of %qT",
5384 : t, type);
5385 0 : non_constant_p = true;
5386 : }
5387 :
5388 0 : if (TREE_CODE (r) == CONSTRUCTOR && CONSTRUCTOR_NO_CLEARING (r))
5389 : {
5390 0 : if (!allow_non_constant)
5391 0 : error ("%qE is not a constant expression because it refers to "
5392 : "an incompletely initialized variable",
5393 : t);
5394 0 : TREE_CONSTANT (r) = false;
5395 0 : non_constant_p = true;
5396 : }
5397 :
5398 0 : if (!global_ctx.heap_vars.is_empty ())
5399 : {
5400 0 : tree heap_var
5401 0 : = rs_walk_tree_without_duplicates (&r, find_heap_var_refs, NULL);
5402 0 : unsigned int i;
5403 0 : if (heap_var)
5404 : {
5405 0 : if (!allow_non_constant && !non_constant_p)
5406 0 : error_at (DECL_SOURCE_LOCATION (heap_var),
5407 : "%qE is not a constant expression because it refers to "
5408 : "a result of %<operator new%>",
5409 : t);
5410 0 : r = t;
5411 0 : non_constant_p = true;
5412 : }
5413 0 : FOR_EACH_VEC_ELT (global_ctx.heap_vars, i, heap_var)
5414 : {
5415 0 : if (DECL_NAME (heap_var) != heap_deleted_identifier)
5416 : {
5417 0 : if (!allow_non_constant && !non_constant_p)
5418 0 : error_at (DECL_SOURCE_LOCATION (heap_var),
5419 : "%qE is not a constant expression because allocated "
5420 : "storage has not been deallocated",
5421 : t);
5422 0 : r = t;
5423 0 : non_constant_p = true;
5424 : }
5425 0 : varpool_node::get (heap_var)->remove ();
5426 : }
5427 : }
5428 :
5429 : /* Check that immediate invocation does not return an expression referencing
5430 : any immediate function decls. */
5431 0 : if (is_consteval || in_immediate_context ())
5432 0 : if (tree immediate_fndecl
5433 0 : = rs_walk_tree_without_duplicates (&r, find_immediate_fndecl, NULL))
5434 : {
5435 0 : if (!allow_non_constant && !non_constant_p)
5436 0 : error_at (rs_expr_loc_or_input_loc (t),
5437 : "immediate evaluation returns address of immediate "
5438 : "function %qD",
5439 : immediate_fndecl);
5440 0 : r = t;
5441 0 : non_constant_p = true;
5442 : }
5443 :
5444 0 : if (non_constant_p)
5445 : /* If we saw something bad, go back to our argument. The wrapping below is
5446 : only for the cases of TREE_CONSTANT argument or overflow. */
5447 0 : r = t;
5448 :
5449 0 : if (!non_constant_p && overflow_p)
5450 0 : non_constant_p = true;
5451 :
5452 : /* Unshare the result. */
5453 0 : bool should_unshare = true;
5454 0 : if (r == t || (TREE_CODE (t) == TARGET_EXPR && TARGET_EXPR_INITIAL (t) == r))
5455 : should_unshare = false;
5456 :
5457 0 : if (non_constant_p && !allow_non_constant)
5458 0 : return error_mark_node;
5459 0 : else if (constexpr_dtor)
5460 : return r;
5461 0 : else if (non_constant_p && TREE_CONSTANT (r))
5462 : {
5463 : /* This isn't actually constant, so unset TREE_CONSTANT.
5464 : Don't clear TREE_CONSTANT on ADDR_EXPR, as the middle-end requires
5465 : it to be set if it is invariant address, even when it is not
5466 : a valid C++ constant expression. Wrap it with a NOP_EXPR
5467 : instead. */
5468 0 : if (EXPR_P (r) && TREE_CODE (r) != ADDR_EXPR)
5469 0 : r = copy_node (r);
5470 0 : else if (TREE_CODE (r) == CONSTRUCTOR)
5471 0 : r = build1 (VIEW_CONVERT_EXPR, TREE_TYPE (r), r);
5472 : else
5473 0 : r = build_nop (TREE_TYPE (r), r);
5474 0 : TREE_CONSTANT (r) = false;
5475 : }
5476 0 : else if (non_constant_p)
5477 : return t;
5478 :
5479 0 : if (should_unshare)
5480 0 : r = unshare_expr (r);
5481 :
5482 0 : if (TREE_CODE (r) == CONSTRUCTOR && CLASS_TYPE_P (TREE_TYPE (r)))
5483 : {
5484 0 : r = adjust_temp_type (type, r);
5485 0 : if (TREE_CODE (t) == TARGET_EXPR && TARGET_EXPR_INITIAL (t) == r)
5486 : return t;
5487 : }
5488 :
5489 : /* Remember the original location if that wouldn't need a wrapper. */
5490 0 : if (location_t loc = EXPR_LOCATION (t))
5491 0 : protected_set_expr_location (r, loc);
5492 :
5493 0 : return r;
5494 0 : }
5495 :
5496 : /* Like is_constant_expression, but allow const variables that are not allowed
5497 : under constexpr rules. */
5498 :
5499 : bool
5500 0 : is_static_init_expression (tree t)
5501 : {
5502 0 : return potential_constant_expression_1 (t, false, false, true, tf_none);
5503 : }
5504 :
5505 : /* Like potential_constant_expression, but don't consider possible constexpr
5506 : substitution of the current function. That is, PARM_DECL qualifies under
5507 : potential_constant_expression, but not here.
5508 :
5509 : This is basically what you can check when any actual constant values might
5510 : be value-dependent. */
5511 :
5512 : bool
5513 0 : is_constant_expression (tree t)
5514 : {
5515 0 : return potential_constant_expression_1 (t, false, true, true, tf_none);
5516 : }
5517 :
5518 : /* Returns true if T is a potential static initializer expression that is not
5519 : instantiation-dependent. */
5520 :
5521 : bool
5522 0 : is_nondependent_static_init_expression (tree t)
5523 : {
5524 0 : return (!type_unknown_p (t) && is_static_init_expression (t));
5525 : }
5526 :
5527 : /* Like maybe_constant_value, but returns a CONSTRUCTOR directly, rather
5528 : than wrapped in a TARGET_EXPR.
5529 : ALLOW_NON_CONSTANT is false if T is required to be a constant expression.
5530 : MANIFESTLY_CONST_EVAL is true if T is manifestly const-evaluated as
5531 : per P0595 even when ALLOW_NON_CONSTANT is true. */
5532 :
5533 : static tree
5534 0 : maybe_constant_init_1 (tree t, tree decl, bool allow_non_constant,
5535 : bool manifestly_const_eval)
5536 : {
5537 0 : if (!t)
5538 : return t;
5539 0 : if (TREE_CODE (t) == EXPR_STMT)
5540 0 : t = TREE_OPERAND (t, 0);
5541 0 : if (TREE_CODE (t) == CONVERT_EXPR && VOID_TYPE_P (TREE_TYPE (t)))
5542 0 : t = TREE_OPERAND (t, 0);
5543 0 : if (TREE_CODE (t) == INIT_EXPR)
5544 0 : t = TREE_OPERAND (t, 1);
5545 0 : if (TREE_CODE (t) == TARGET_EXPR)
5546 0 : t = TARGET_EXPR_INITIAL (t);
5547 0 : if (!is_nondependent_static_init_expression (t))
5548 : /* Don't try to evaluate it. */;
5549 0 : else if (CONSTANT_CLASS_P (t) && allow_non_constant)
5550 : /* No evaluation needed. */;
5551 : else
5552 0 : t = cxx_eval_outermost_constant_expr (t, allow_non_constant,
5553 : /*strict*/ false,
5554 : manifestly_const_eval, false, decl);
5555 0 : if (TREE_CODE (t) == TARGET_EXPR)
5556 : {
5557 0 : tree init = TARGET_EXPR_INITIAL (t);
5558 0 : if (TREE_CODE (init) == CONSTRUCTOR)
5559 0 : t = init;
5560 : }
5561 : return t;
5562 : }
5563 :
5564 : /* Wrapper for maybe_constant_init_1 which permits non constants. */
5565 :
5566 : tree
5567 0 : maybe_constant_init (tree t, tree decl, bool manifestly_const_eval)
5568 : {
5569 0 : return maybe_constant_init_1 (t, decl, true, manifestly_const_eval);
5570 : }
5571 :
5572 : /* Returns true if T is a potential constant expression that is not
5573 : instantiation-dependent, and therefore a candidate for constant folding even
5574 : in a template. */
5575 :
5576 : bool
5577 0 : is_nondependent_constant_expression (tree t)
5578 : {
5579 0 : return (!type_unknown_p (t) && is_constant_expression (t)
5580 0 : && !instantiation_dependent_expression_p (t));
5581 : }
5582 :
5583 : // forked from gcc/cp/parser.cc cp_unevaluated_operand
5584 :
5585 : /* Nonzero if we are parsing an unevaluated operand: an operand to
5586 : sizeof, typeof, or alignof. */
5587 : int cp_unevaluated_operand;
5588 :
5589 : // forked from gcc/cp/constexpr.cc cv_cache
5590 :
5591 : /* If T is a constant expression, returns its reduced value.
5592 : Otherwise, if T does not have TREE_CONSTANT set, returns T.
5593 : Otherwise, returns a version of T without TREE_CONSTANT.
5594 : MANIFESTLY_CONST_EVAL is true if T is manifestly const-evaluated
5595 : as per P0595. */
5596 :
5597 : static GTY ((deletable)) hash_map<tree, tree> *cv_cache;
5598 :
5599 : // forked from gcc/cp/constexpr.cc maybe_constant_value
5600 :
5601 : tree
5602 0 : maybe_constant_value (tree t, tree decl, bool manifestly_const_eval)
5603 : {
5604 0 : tree r;
5605 :
5606 0 : if (!is_nondependent_constant_expression (t))
5607 : {
5608 0 : if (TREE_OVERFLOW_P (t))
5609 : {
5610 0 : t = build_nop (TREE_TYPE (t), t);
5611 0 : TREE_CONSTANT (t) = false;
5612 : }
5613 0 : return t;
5614 : }
5615 0 : else if (CONSTANT_CLASS_P (t))
5616 : /* No caching or evaluation needed. */
5617 : return t;
5618 :
5619 0 : if (manifestly_const_eval)
5620 0 : return cxx_eval_outermost_constant_expr (t, true, true, true, false, decl);
5621 :
5622 0 : if (cv_cache == NULL)
5623 0 : cv_cache = hash_map<tree, tree>::create_ggc (101);
5624 0 : if (tree *cached = cv_cache->get (t))
5625 : {
5626 0 : r = *cached;
5627 0 : if (r != t)
5628 : {
5629 : // Faisal: commenting this out as not sure if it's needed and it's
5630 : // huge r = break_out_target_exprs (r, /*clear_loc*/true);
5631 0 : protected_set_expr_location (r, EXPR_LOCATION (t));
5632 : }
5633 0 : return r;
5634 : }
5635 :
5636 : /* Don't evaluate an unevaluated operand. */
5637 0 : if (cp_unevaluated_operand)
5638 : return t;
5639 :
5640 0 : uid_sensitive_constexpr_evaluation_checker c;
5641 0 : r = cxx_eval_outermost_constant_expr (t, true, true, false, false, decl);
5642 0 : gcc_checking_assert (
5643 : r == t || CONVERT_EXPR_P (t) || TREE_CODE (t) == VIEW_CONVERT_EXPR
5644 : || (TREE_CONSTANT (t) && !TREE_CONSTANT (r)) || !rs_tree_equal (r, t));
5645 0 : if (!c.evaluation_restricted_p ())
5646 0 : cv_cache->put (t, r);
5647 : return r;
5648 : }
5649 :
5650 : // forked from gcc/cp/constexpr.cc
5651 :
5652 : bool
5653 0 : potential_constant_expression (tree t)
5654 : {
5655 0 : return potential_constant_expression_1 (t, false, true, false, tf_none);
5656 : }
5657 :
5658 : /* Data structure for passing data from potential_constant_expression_1
5659 : to check_for_return_continue via cp_walk_tree. */
5660 : struct check_for_return_continue_data
5661 : {
5662 : hash_set<tree> *pset;
5663 : tree continue_stmt;
5664 : tree break_stmt;
5665 : };
5666 :
5667 : /* Helper function for potential_constant_expression_1 SWITCH_STMT handling,
5668 : called through cp_walk_tree. Return the first RETURN_EXPR found, or note
5669 : the first CONTINUE_STMT and/or BREAK_STMT if RETURN_EXPR is not found. */
5670 : static tree
5671 0 : check_for_return_continue (tree *tp, int *walk_subtrees, void *data)
5672 : {
5673 0 : tree t = *tp, s, b;
5674 0 : check_for_return_continue_data *d = (check_for_return_continue_data *) data;
5675 0 : switch (TREE_CODE (t))
5676 : {
5677 : case RETURN_EXPR:
5678 : return t;
5679 :
5680 0 : case CONTINUE_STMT:
5681 0 : if (d->continue_stmt == NULL_TREE)
5682 0 : d->continue_stmt = t;
5683 : break;
5684 :
5685 0 : case BREAK_STMT:
5686 0 : if (d->break_stmt == NULL_TREE)
5687 0 : d->break_stmt = t;
5688 : break;
5689 :
5690 : #define RECUR(x) \
5691 : if (tree r = rs_walk_tree (&x, check_for_return_continue, data, d->pset)) \
5692 : return r
5693 :
5694 : /* For loops, walk subtrees manually, so that continue stmts found
5695 : inside of the bodies of the loops are ignored. */
5696 :
5697 0 : case WHILE_STMT:
5698 0 : *walk_subtrees = 0;
5699 0 : RECUR (WHILE_COND (t));
5700 0 : s = d->continue_stmt;
5701 0 : b = d->break_stmt;
5702 0 : RECUR (WHILE_BODY (t));
5703 0 : d->continue_stmt = s;
5704 0 : d->break_stmt = b;
5705 0 : break;
5706 :
5707 0 : case FOR_STMT:
5708 0 : *walk_subtrees = 0;
5709 0 : RECUR (FOR_INIT_STMT (t));
5710 0 : RECUR (FOR_COND (t));
5711 0 : RECUR (FOR_EXPR (t));
5712 0 : s = d->continue_stmt;
5713 0 : b = d->break_stmt;
5714 0 : RECUR (FOR_BODY (t));
5715 0 : d->continue_stmt = s;
5716 0 : d->break_stmt = b;
5717 0 : break;
5718 :
5719 0 : case RANGE_FOR_STMT:
5720 0 : *walk_subtrees = 0;
5721 0 : RECUR (RANGE_FOR_EXPR (t));
5722 0 : s = d->continue_stmt;
5723 0 : b = d->break_stmt;
5724 0 : RECUR (RANGE_FOR_BODY (t));
5725 0 : d->continue_stmt = s;
5726 0 : d->break_stmt = b;
5727 0 : break;
5728 :
5729 0 : case SWITCH_STMT:
5730 0 : *walk_subtrees = 0;
5731 0 : RECUR (SWITCH_STMT_COND (t));
5732 0 : b = d->break_stmt;
5733 0 : RECUR (SWITCH_STMT_BODY (t));
5734 0 : d->break_stmt = b;
5735 0 : break;
5736 : #undef RECUR
5737 :
5738 : case STATEMENT_LIST:
5739 : case CONSTRUCTOR:
5740 : break;
5741 :
5742 0 : default:
5743 0 : if (!EXPR_P (t))
5744 0 : *walk_subtrees = 0;
5745 : break;
5746 : }
5747 :
5748 : return NULL_TREE;
5749 : }
5750 :
5751 : /* Returns the namespace that contains DECL, whether directly or
5752 : indirectly. */
5753 :
5754 : tree
5755 0 : decl_namespace_context (tree decl)
5756 : {
5757 0 : while (1)
5758 : {
5759 0 : if (TREE_CODE (decl) == NAMESPACE_DECL)
5760 0 : return decl;
5761 0 : else if (TYPE_P (decl))
5762 0 : decl = CP_DECL_CONTEXT (TYPE_MAIN_DECL (decl));
5763 : else
5764 0 : decl = CP_DECL_CONTEXT (decl);
5765 : }
5766 : }
5767 :
5768 : /* Returns true if DECL is in the std namespace. */
5769 :
5770 : bool
5771 0 : decl_in_std_namespace_p (tree decl)
5772 : {
5773 0 : while (decl)
5774 : {
5775 0 : decl = decl_namespace_context (decl);
5776 0 : if (DECL_NAMESPACE_STD_P (decl))
5777 : return true;
5778 : /* Allow inline namespaces inside of std namespace, e.g. with
5779 : --enable-symvers=gnu-versioned-namespace std::forward would be
5780 : actually std::_8::forward. */
5781 0 : if (!DECL_NAMESPACE_INLINE_P (decl))
5782 : return false;
5783 0 : decl = CP_DECL_CONTEXT (decl);
5784 : }
5785 : return false;
5786 : }
5787 :
5788 : /* Return true if FNDECL is std::construct_at. */
5789 :
5790 : static inline bool
5791 : is_std_construct_at (tree fndecl)
5792 : {
5793 : if (!decl_in_std_namespace_p (fndecl))
5794 : return false;
5795 :
5796 : tree name = DECL_NAME (fndecl);
5797 : return name && id_equal (name, "construct_at");
5798 : }
5799 :
5800 : /* Return true if FNDECL is __dynamic_cast. */
5801 :
5802 : static inline bool
5803 : cxx_dynamic_cast_fn_p (tree fndecl)
5804 : {
5805 : return (id_equal (DECL_NAME (fndecl), "__dynamic_cast")
5806 : && CP_DECL_CONTEXT (fndecl) == global_namespace);
5807 : }
5808 :
5809 : /* Return true if FNDECL is std::allocator<T>::{,de}allocate. */
5810 :
5811 : static inline bool
5812 : is_std_allocator_allocate (tree fndecl)
5813 : {
5814 : tree name = DECL_NAME (fndecl);
5815 : if (name == NULL_TREE
5816 : || !(id_equal (name, "allocate") || id_equal (name, "deallocate")))
5817 : return false;
5818 :
5819 : tree ctx = DECL_CONTEXT (fndecl);
5820 : if (ctx == NULL_TREE || !CLASS_TYPE_P (ctx) || !TYPE_MAIN_DECL (ctx))
5821 : return false;
5822 :
5823 : tree decl = TYPE_MAIN_DECL (ctx);
5824 : name = DECL_NAME (decl);
5825 : if (name == NULL_TREE || !id_equal (name, "allocator"))
5826 : return false;
5827 :
5828 : return decl_in_std_namespace_p (decl);
5829 : }
5830 :
5831 : /* Overload for the above taking rust_constexpr_call*. */
5832 :
5833 : static inline bool
5834 : is_std_allocator_allocate (const rust_constexpr_call *call)
5835 : {
5836 : return (call && call->fundef
5837 : && is_std_allocator_allocate (call->fundef->decl));
5838 : }
5839 :
5840 : /* Return true if T denotes a potentially constant expression. Issue
5841 : diagnostic as appropriate under control of FLAGS. If WANT_RVAL is true,
5842 : an lvalue-rvalue conversion is implied. If NOW is true, we want to
5843 : consider the expression in the current context, independent of constexpr
5844 : substitution.
5845 :
5846 : C++0x [expr.const] used to say
5847 :
5848 : 6 An expression is a potential constant expression if it is
5849 : a constant expression where all occurrences of function
5850 : parameters are replaced by arbitrary constant expressions
5851 : of the appropriate type.
5852 :
5853 : 2 A conditional expression is a constant expression unless it
5854 : involves one of the following as a potentially evaluated
5855 : subexpression (3.2), but subexpressions of logical AND (5.14),
5856 : logical OR (5.15), and conditional (5.16) operations that are
5857 : not evaluated are not considered. */
5858 :
5859 : static bool
5860 0 : potential_constant_expression_1 (tree t, bool want_rval, bool strict, bool now,
5861 : tsubst_flags_t flags, tree *jump_target)
5862 : {
5863 : #define RECUR(T, RV) \
5864 : potential_constant_expression_1 ((T), (RV), strict, now, flags, jump_target)
5865 :
5866 0 : enum
5867 : {
5868 : any = false,
5869 : rval = true
5870 : };
5871 0 : int i;
5872 0 : tree tmp;
5873 :
5874 0 : if (t == error_mark_node)
5875 : return false;
5876 0 : if (t == NULL_TREE)
5877 : return true;
5878 0 : location_t loc = rs_expr_loc_or_input_loc (t);
5879 :
5880 0 : if (*jump_target)
5881 : /* If we are jumping, ignore everything. This is simpler than the
5882 : cxx_eval_constant_expression handling because we only need to be
5883 : conservatively correct, and we don't necessarily have a constant value
5884 : available, so we don't bother with switch tracking. */
5885 : return true;
5886 :
5887 0 : if (TREE_THIS_VOLATILE (t) && want_rval)
5888 : {
5889 0 : if (flags & tf_error)
5890 0 : error_at (loc,
5891 : "lvalue-to-rvalue conversion of a volatile lvalue "
5892 : "%qE with type %qT",
5893 0 : t, TREE_TYPE (t));
5894 0 : return false;
5895 : }
5896 0 : if (CONSTANT_CLASS_P (t))
5897 : return true;
5898 0 : if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_TYPED)
5899 0 : && TREE_TYPE (t) == error_mark_node)
5900 : return false;
5901 :
5902 0 : switch (TREE_CODE (t))
5903 : {
5904 : case FUNCTION_DECL:
5905 : case OVERLOAD:
5906 : case LABEL_DECL:
5907 : case CASE_LABEL_EXPR:
5908 : case PREDICT_EXPR:
5909 : case CONST_DECL:
5910 : case IDENTIFIER_NODE:
5911 : /* We can see a FIELD_DECL in a pointer-to-member expression. */
5912 : case FIELD_DECL:
5913 : case RESULT_DECL:
5914 : case PLACEHOLDER_EXPR:
5915 : case STATIC_ASSERT:
5916 : return true;
5917 :
5918 0 : case RETURN_EXPR:
5919 0 : if (!RECUR (TREE_OPERAND (t, 0), any))
5920 : return false;
5921 : /* FALLTHROUGH */
5922 :
5923 0 : case BREAK_STMT:
5924 0 : case CONTINUE_STMT:
5925 0 : *jump_target = t;
5926 0 : return true;
5927 :
5928 0 : case PARM_DECL:
5929 0 : if (now && want_rval)
5930 : {
5931 0 : tree type = TREE_TYPE (t);
5932 0 : if (is_really_empty_class (type, /*ignore_vptr*/ false))
5933 : /* An empty class has no data to read. */
5934 : return true;
5935 0 : if (flags & tf_error)
5936 0 : error ("%qE is not a constant expression", t);
5937 0 : return false;
5938 : }
5939 : return true;
5940 :
5941 0 : case CALL_EXPR:
5942 : /* -- an invocation of a function other than a constexpr function
5943 : or a constexpr constructor. */
5944 0 : {
5945 0 : tree fun = get_function_named_in_call (t);
5946 0 : const int nargs = call_expr_nargs (t);
5947 0 : i = 0;
5948 :
5949 0 : if (fun == NULL_TREE)
5950 : {
5951 : /* Reset to allow the function to continue past the end
5952 : of the block below. Otherwise return early. */
5953 0 : bool bail = true;
5954 :
5955 0 : if (TREE_CODE (t) == CALL_EXPR && CALL_EXPR_FN (t) == NULL_TREE)
5956 0 : switch (CALL_EXPR_IFN (t))
5957 : {
5958 : /* These should be ignored, they are optimized away from
5959 : constexpr functions. */
5960 : case IFN_UBSAN_NULL:
5961 : case IFN_UBSAN_BOUNDS:
5962 : case IFN_UBSAN_VPTR:
5963 : case IFN_FALLTHROUGH:
5964 : return true;
5965 :
5966 : case IFN_ADD_OVERFLOW:
5967 : case IFN_SUB_OVERFLOW:
5968 : case IFN_MUL_OVERFLOW:
5969 : case IFN_LAUNDER:
5970 : case IFN_VEC_CONVERT:
5971 : bail = false;
5972 : break;
5973 :
5974 : default:
5975 : break;
5976 : }
5977 :
5978 : if (bail)
5979 : {
5980 : /* fold_call_expr can't do anything with IFN calls. */
5981 0 : if (flags & tf_error)
5982 0 : error_at (loc, "call to internal function %qE", t);
5983 0 : return false;
5984 : }
5985 : }
5986 :
5987 0 : if (fun && is_overloaded_fn (fun))
5988 : {
5989 0 : if (TREE_CODE (fun) == FUNCTION_DECL)
5990 : {
5991 0 : if (builtin_valid_in_constant_expr_p (fun))
5992 : return true;
5993 0 : if (!maybe_constexpr_fn (fun)
5994 : /* Allow any built-in function; if the expansion
5995 : isn't constant, we'll deal with that then. */
5996 0 : && !fndecl_built_in_p (fun)
5997 : /* In C++20, replaceable global allocation functions
5998 : are constant expressions. */
5999 0 : && (/* !cxx_replaceable_global_alloc_fn (fun)
6000 0 : ||*/ TREE_CODE (t) != CALL_EXPR
6001 0 : || (!CALL_FROM_NEW_OR_DELETE_P (t)
6002 0 : && (current_function_decl == NULL_TREE
6003 : /*|| !is_std_allocator_allocate(current_function_decl)*/)))
6004 : /* Allow placement new in std::construct_at. */
6005 0 : && (/*!cxx_placement_new_fn (fun)
6006 : ||*/ TREE_CODE (t) != CALL_EXPR
6007 0 : || current_function_decl == NULL_TREE
6008 : /*|| !is_std_construct_at (current_function_decl)*/)
6009 : /* && !cxx_dynamic_cast_fn_p (fun)*/)
6010 : {
6011 0 : if (flags & tf_error)
6012 : {
6013 0 : error_at (loc, "call to non-%<constexpr%> function %qD",
6014 : fun);
6015 0 : explain_invalid_constexpr_fn (fun);
6016 : }
6017 0 : return false;
6018 : }
6019 : /* A call to a non-static member function takes the address
6020 : of the object as the first argument. But in a constant
6021 : expression the address will be folded away, so look
6022 : through it now. */
6023 0 : if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fun)
6024 0 : && !DECL_CONSTRUCTOR_P (fun))
6025 : {
6026 0 : tree x = CALL_EXPR_ARG (t, 0);
6027 :
6028 : /* Don't require an immediately constant value, as
6029 : constexpr substitution might not use the value. */
6030 0 : bool sub_now = false;
6031 0 : if (!potential_constant_expression_1 (x, rval, strict,
6032 : sub_now, flags,
6033 : jump_target))
6034 : return false;
6035 : i = 1;
6036 : }
6037 : }
6038 : else
6039 : {
6040 0 : if (!RECUR (fun, true))
6041 : return false;
6042 0 : fun = get_first_fn (fun);
6043 : }
6044 0 : fun = DECL_ORIGIN (fun);
6045 : }
6046 0 : else if (fun)
6047 : {
6048 0 : if (RECUR (fun, rval))
6049 : /* Might end up being a constant function pointer. */;
6050 : else
6051 : return false;
6052 : }
6053 0 : for (; i < nargs; ++i)
6054 : {
6055 0 : tree x = CALL_EXPR_ARG (t, i);
6056 : /* In a template, reference arguments haven't been converted to
6057 : REFERENCE_TYPE and we might not even know if the parameter
6058 : is a reference, so accept lvalue constants too. */
6059 0 : bool rv = rval;
6060 : /* Don't require an immediately constant value, as constexpr
6061 : substitution might not use the value of the argument. */
6062 0 : bool sub_now = false;
6063 0 : if (!potential_constant_expression_1 (x, rv, strict, sub_now, flags,
6064 : jump_target))
6065 : return false;
6066 : }
6067 : return true;
6068 : }
6069 :
6070 0 : case NON_LVALUE_EXPR:
6071 : /* -- an lvalue-to-rvalue conversion (4.1) unless it is applied to
6072 : -- an lvalue of integral type that refers to a non-volatile
6073 : const variable or static data member initialized with
6074 : constant expressions, or
6075 :
6076 : -- an lvalue of literal type that refers to non-volatile
6077 : object defined with constexpr, or that refers to a
6078 : sub-object of such an object; */
6079 0 : return RECUR (TREE_OPERAND (t, 0), rval);
6080 :
6081 0 : case VAR_DECL:
6082 0 : if (DECL_HAS_VALUE_EXPR_P (t))
6083 : {
6084 0 : return RECUR (DECL_VALUE_EXPR (t), rval);
6085 : }
6086 0 : if (want_rval && !var_in_maybe_constexpr_fn (t)
6087 0 : && !decl_maybe_constant_var_p (t)
6088 0 : && (strict || !RS_TYPE_CONST_NON_VOLATILE_P (TREE_TYPE (t))
6089 0 : || (DECL_INITIAL (t)
6090 0 : && !DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (t)))
6091 0 : && COMPLETE_TYPE_P (TREE_TYPE (t))
6092 0 : && !is_really_empty_class (TREE_TYPE (t), /*ignore_vptr*/ false))
6093 : {
6094 0 : if (flags & tf_error)
6095 0 : non_const_var_error (loc, t);
6096 0 : return false;
6097 : }
6098 : return true;
6099 :
6100 : /* FALLTHRU */
6101 0 : case NOP_EXPR:
6102 0 : case CONVERT_EXPR:
6103 0 : case VIEW_CONVERT_EXPR:
6104 : /* -- a reinterpret_cast. FIXME not implemented, and this rule
6105 : may change to something more specific to type-punning (DR 1312). */
6106 0 : {
6107 0 : tree from = TREE_OPERAND (t, 0);
6108 0 : if (location_wrapper_p (t))
6109 0 : return (RECUR (from, want_rval));
6110 0 : if (INDIRECT_TYPE_P (TREE_TYPE (t)))
6111 : {
6112 0 : STRIP_ANY_LOCATION_WRAPPER (from);
6113 0 : if (TREE_CODE (from) == INTEGER_CST && !integer_zerop (from))
6114 : {
6115 0 : if (flags & tf_error)
6116 0 : error_at (loc,
6117 : "%<reinterpret_cast%> from integer to pointer");
6118 0 : return false;
6119 : }
6120 : }
6121 0 : return (RECUR (from, TREE_CODE (t) != VIEW_CONVERT_EXPR));
6122 : }
6123 :
6124 0 : case ADDR_EXPR:
6125 : /* -- a unary operator & that is applied to an lvalue that
6126 : designates an object with thread or automatic storage
6127 : duration; */
6128 0 : t = TREE_OPERAND (t, 0);
6129 :
6130 0 : if (TREE_CODE (t) == OFFSET_REF && PTRMEM_OK_P (t))
6131 : /* A pointer-to-member constant. */
6132 : return true;
6133 :
6134 : #if 0
6135 : /* FIXME adjust when issue 1197 is fully resolved. For now don't do
6136 : any checking here, as we might dereference the pointer later. If
6137 : we remove this code, also remove check_automatic_or_tls. */
6138 : i = check_automatic_or_tls (t);
6139 : if (i == ck_ok)
6140 : return true;
6141 : if (i == ck_bad)
6142 : {
6143 : if (flags & tf_error)
6144 : error ("address-of an object %qE with thread local or "
6145 : "automatic storage is not a constant expression", t);
6146 : return false;
6147 : }
6148 : #endif
6149 0 : return RECUR (t, any);
6150 :
6151 0 : case COMPONENT_REF:
6152 : /* -- a class member access unless its postfix-expression is
6153 : of literal type or of pointer to literal type. */
6154 : /* This test would be redundant, as it follows from the
6155 : postfix-expression being a potential constant expression. */
6156 0 : if (type_unknown_p (t))
6157 : return true;
6158 0 : if (is_overloaded_fn (t))
6159 : /* In a template, a COMPONENT_REF of a function expresses ob.fn(),
6160 : which uses ob as an lvalue. */
6161 0 : want_rval = false;
6162 0 : gcc_fallthrough ();
6163 :
6164 0 : case REALPART_EXPR:
6165 0 : case IMAGPART_EXPR:
6166 0 : case BIT_FIELD_REF:
6167 0 : return RECUR (TREE_OPERAND (t, 0), want_rval);
6168 :
6169 0 : case INDIRECT_REF:
6170 0 : {
6171 0 : tree x = TREE_OPERAND (t, 0);
6172 0 : STRIP_NOPS (x);
6173 0 : return RECUR (x, rval);
6174 : }
6175 :
6176 0 : case STATEMENT_LIST:
6177 0 : for (tree stmt : tsi_range (t))
6178 0 : if (!RECUR (stmt, any))
6179 0 : return false;
6180 : return true;
6181 :
6182 0 : case MODIFY_EXPR:
6183 0 : if (!RECUR (TREE_OPERAND (t, 0), any))
6184 : return false;
6185 : /* Just ignore clobbers. */
6186 0 : if (TREE_CLOBBER_P (TREE_OPERAND (t, 1)))
6187 : return true;
6188 0 : if (!RECUR (TREE_OPERAND (t, 1), rval))
6189 : return false;
6190 : return true;
6191 :
6192 0 : case FOR_STMT:
6193 0 : if (!RECUR (FOR_INIT_STMT (t), any))
6194 : return false;
6195 0 : tmp = FOR_COND (t);
6196 0 : if (!RECUR (tmp, rval))
6197 : return false;
6198 0 : if (tmp)
6199 : {
6200 0 : tmp = cxx_eval_outermost_constant_expr (tmp, true);
6201 : /* If we couldn't evaluate the condition, it might not ever be
6202 : true. */
6203 0 : if (!integer_onep (tmp))
6204 : {
6205 : /* Before returning true, check if the for body can contain
6206 : a return. */
6207 0 : hash_set<tree> pset;
6208 0 : check_for_return_continue_data data
6209 0 : = {&pset, NULL_TREE, NULL_TREE};
6210 0 : if (tree ret_expr
6211 0 : = rs_walk_tree (&FOR_BODY (t), check_for_return_continue,
6212 : &data, &pset))
6213 0 : *jump_target = ret_expr;
6214 0 : return true;
6215 0 : }
6216 : }
6217 0 : if (!RECUR (FOR_EXPR (t), any))
6218 : return false;
6219 0 : if (!RECUR (FOR_BODY (t), any))
6220 : return false;
6221 0 : if (breaks (jump_target) || continues (jump_target))
6222 0 : *jump_target = NULL_TREE;
6223 : return true;
6224 :
6225 0 : case WHILE_STMT:
6226 0 : tmp = WHILE_COND (t);
6227 0 : if (!RECUR (tmp, rval))
6228 : return false;
6229 :
6230 0 : tmp = cxx_eval_outermost_constant_expr (tmp, true);
6231 : /* If we couldn't evaluate the condition, it might not ever be true. */
6232 0 : if (!integer_onep (tmp))
6233 : {
6234 : /* Before returning true, check if the while body can contain
6235 : a return. */
6236 0 : hash_set<tree> pset;
6237 0 : check_for_return_continue_data data = {&pset, NULL_TREE, NULL_TREE};
6238 0 : if (tree ret_expr
6239 0 : = rs_walk_tree (&WHILE_BODY (t), check_for_return_continue, &data,
6240 : &pset))
6241 0 : *jump_target = ret_expr;
6242 0 : return true;
6243 0 : }
6244 0 : if (!RECUR (WHILE_BODY (t), any))
6245 : return false;
6246 0 : if (breaks (jump_target) || continues (jump_target))
6247 0 : *jump_target = NULL_TREE;
6248 : return true;
6249 :
6250 0 : case SWITCH_STMT:
6251 0 : if (!RECUR (SWITCH_STMT_COND (t), rval))
6252 : return false;
6253 : /* FIXME we don't check SWITCH_STMT_BODY currently, because even
6254 : unreachable labels would be checked and it is enough if there is
6255 : a single switch cond value for which it is a valid constant
6256 : expression. We need to check if there are any RETURN_EXPRs
6257 : or CONTINUE_STMTs inside of the body though, as in that case
6258 : we need to set *jump_target. */
6259 : else
6260 : {
6261 0 : hash_set<tree> pset;
6262 0 : check_for_return_continue_data data = {&pset, NULL_TREE, NULL_TREE};
6263 0 : if (tree ret_expr
6264 0 : = rs_walk_tree (&SWITCH_STMT_BODY (t), check_for_return_continue,
6265 : &data, &pset))
6266 : /* The switch might return. */
6267 0 : *jump_target = ret_expr;
6268 0 : else if (data.continue_stmt)
6269 : /* The switch can't return, but might continue. */
6270 0 : *jump_target = data.continue_stmt;
6271 0 : }
6272 0 : return true;
6273 :
6274 0 : case DYNAMIC_CAST_EXPR:
6275 0 : case PSEUDO_DTOR_EXPR:
6276 0 : case NEW_EXPR:
6277 0 : case VEC_NEW_EXPR:
6278 0 : case DELETE_EXPR:
6279 0 : case VEC_DELETE_EXPR:
6280 0 : case THROW_EXPR:
6281 0 : case OMP_PARALLEL:
6282 0 : case OMP_TASK:
6283 0 : case OMP_FOR:
6284 0 : case OMP_SIMD:
6285 0 : case OMP_DISTRIBUTE:
6286 0 : case OMP_TASKLOOP:
6287 0 : case OMP_LOOP:
6288 0 : case OMP_TEAMS:
6289 0 : case OMP_TARGET_DATA:
6290 0 : case OMP_TARGET:
6291 0 : case OMP_SECTIONS:
6292 0 : case OMP_ORDERED:
6293 0 : case OMP_CRITICAL:
6294 0 : case OMP_SINGLE:
6295 0 : case OMP_SECTION:
6296 0 : case OMP_MASTER:
6297 0 : case OMP_MASKED:
6298 0 : case OMP_TASKGROUP:
6299 0 : case OMP_TARGET_UPDATE:
6300 0 : case OMP_TARGET_ENTER_DATA:
6301 0 : case OMP_TARGET_EXIT_DATA:
6302 0 : case OMP_ATOMIC:
6303 0 : case OMP_ATOMIC_READ:
6304 0 : case OMP_ATOMIC_CAPTURE_OLD:
6305 0 : case OMP_ATOMIC_CAPTURE_NEW:
6306 0 : case OMP_DEPOBJ:
6307 0 : case OACC_PARALLEL:
6308 0 : case OACC_KERNELS:
6309 0 : case OACC_SERIAL:
6310 0 : case OACC_DATA:
6311 0 : case OACC_HOST_DATA:
6312 0 : case OACC_LOOP:
6313 0 : case OACC_CACHE:
6314 0 : case OACC_DECLARE:
6315 0 : case OACC_ENTER_DATA:
6316 0 : case OACC_EXIT_DATA:
6317 0 : case OACC_UPDATE:
6318 : /* GCC internal stuff. */
6319 0 : case VA_ARG_EXPR:
6320 0 : case TRANSACTION_EXPR:
6321 0 : case AT_ENCODE_EXPR:
6322 :
6323 0 : if (flags & tf_error)
6324 0 : error_at (loc, "expression %qE is not a constant expression", t);
6325 : return false;
6326 :
6327 0 : case ASM_EXPR:
6328 0 : if (flags & tf_error)
6329 0 : inline_asm_in_constexpr_error (loc);
6330 : return false;
6331 :
6332 : case OBJ_TYPE_REF:
6333 : return true;
6334 :
6335 0 : case POINTER_DIFF_EXPR:
6336 0 : case MINUS_EXPR:
6337 0 : want_rval = true;
6338 0 : goto binary;
6339 :
6340 0 : case LT_EXPR:
6341 0 : case LE_EXPR:
6342 0 : case GT_EXPR:
6343 0 : case GE_EXPR:
6344 0 : case EQ_EXPR:
6345 0 : case NE_EXPR:
6346 0 : case SPACESHIP_EXPR:
6347 0 : want_rval = true;
6348 0 : goto binary;
6349 :
6350 0 : case PREINCREMENT_EXPR:
6351 0 : case POSTINCREMENT_EXPR:
6352 0 : case PREDECREMENT_EXPR:
6353 0 : case POSTDECREMENT_EXPR:
6354 0 : goto unary;
6355 :
6356 0 : case BIT_NOT_EXPR:
6357 : /* A destructor. */
6358 0 : if (TYPE_P (TREE_OPERAND (t, 0)))
6359 : return true;
6360 : /* fall through. */
6361 :
6362 0 : case CONJ_EXPR:
6363 0 : case SAVE_EXPR:
6364 0 : case FIX_TRUNC_EXPR:
6365 0 : case FLOAT_EXPR:
6366 0 : case NEGATE_EXPR:
6367 0 : case ABS_EXPR:
6368 0 : case ABSU_EXPR:
6369 0 : case TRUTH_NOT_EXPR:
6370 0 : case FIXED_CONVERT_EXPR:
6371 0 : case UNARY_PLUS_EXPR:
6372 0 : case UNARY_LEFT_FOLD_EXPR:
6373 0 : case UNARY_RIGHT_FOLD_EXPR:
6374 0 : unary:
6375 0 : return RECUR (TREE_OPERAND (t, 0), rval);
6376 :
6377 0 : case BIND_EXPR:
6378 0 : return RECUR (BIND_EXPR_BODY (t), want_rval);
6379 :
6380 0 : case CLEANUP_POINT_EXPR:
6381 0 : case EXPR_STMT:
6382 0 : case PAREN_EXPR:
6383 : /* For convenience. */
6384 0 : case LOOP_EXPR:
6385 0 : case EXIT_EXPR:
6386 0 : return RECUR (TREE_OPERAND (t, 0), want_rval);
6387 :
6388 0 : case DECL_EXPR:
6389 0 : tmp = DECL_EXPR_DECL (t);
6390 0 : if (VAR_P (tmp) && !DECL_ARTIFICIAL (tmp))
6391 : {
6392 0 : if (RS_DECL_THREAD_LOCAL_P (tmp))
6393 : {
6394 0 : if (flags & tf_error)
6395 0 : error_at (DECL_SOURCE_LOCATION (tmp),
6396 : "%qD declared "
6397 : "%<thread_local%> in %<constexpr%> context",
6398 : tmp);
6399 0 : return false;
6400 : }
6401 0 : else if (TREE_STATIC (tmp))
6402 : {
6403 0 : if (flags & tf_error)
6404 0 : error_at (DECL_SOURCE_LOCATION (tmp),
6405 : "%qD declared "
6406 : "%<static%> in %<constexpr%> context",
6407 : tmp);
6408 0 : return false;
6409 : }
6410 0 : else if (!check_for_uninitialized_const_var (
6411 : tmp, /*constexpr_context_p=*/true, flags))
6412 : return false;
6413 : }
6414 0 : return RECUR (tmp, want_rval);
6415 :
6416 0 : case TRY_FINALLY_EXPR:
6417 0 : return (RECUR (TREE_OPERAND (t, 0), want_rval)
6418 0 : && RECUR (TREE_OPERAND (t, 1), any));
6419 :
6420 0 : case SCOPE_REF:
6421 0 : return RECUR (TREE_OPERAND (t, 1), want_rval);
6422 :
6423 0 : case TARGET_EXPR:
6424 0 : if (!TARGET_EXPR_DIRECT_INIT_P (t) && !literal_type_p (TREE_TYPE (t)))
6425 : {
6426 0 : if (flags & tf_error)
6427 : {
6428 0 : auto_diagnostic_group d;
6429 0 : error_at (loc,
6430 : "temporary of non-literal type %qT in a "
6431 : "constant expression",
6432 0 : TREE_TYPE (t));
6433 0 : explain_non_literal_class (TREE_TYPE (t));
6434 0 : }
6435 0 : return false;
6436 : }
6437 : /* FALLTHRU */
6438 0 : case INIT_EXPR:
6439 0 : return RECUR (TREE_OPERAND (t, 1), rval);
6440 :
6441 0 : case CONSTRUCTOR:
6442 0 : {
6443 0 : vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (t);
6444 0 : constructor_elt *ce;
6445 0 : for (i = 0; vec_safe_iterate (v, i, &ce); ++i)
6446 0 : if (!RECUR (ce->value, want_rval))
6447 : return false;
6448 : return true;
6449 : }
6450 :
6451 0 : case TREE_LIST:
6452 0 : {
6453 0 : gcc_assert (TREE_PURPOSE (t) == NULL_TREE || DECL_P (TREE_PURPOSE (t)));
6454 0 : if (!RECUR (TREE_VALUE (t), want_rval))
6455 : return false;
6456 0 : if (TREE_CHAIN (t) == NULL_TREE)
6457 : return true;
6458 0 : return RECUR (TREE_CHAIN (t), want_rval);
6459 : }
6460 :
6461 0 : case TRUNC_DIV_EXPR:
6462 0 : case CEIL_DIV_EXPR:
6463 0 : case FLOOR_DIV_EXPR:
6464 0 : case ROUND_DIV_EXPR:
6465 0 : case TRUNC_MOD_EXPR:
6466 0 : case CEIL_MOD_EXPR:
6467 0 : case ROUND_MOD_EXPR:
6468 0 : {
6469 0 : tree denom = TREE_OPERAND (t, 1);
6470 0 : if (!RECUR (denom, rval))
6471 : return false;
6472 : /* We can't call cxx_eval_outermost_constant_expr on an expression
6473 : that hasn't been through instantiate_non_dependent_expr yet. */
6474 0 : denom = cxx_eval_outermost_constant_expr (denom, true);
6475 0 : if (integer_zerop (denom))
6476 : {
6477 0 : if (flags & tf_error)
6478 0 : error ("division by zero is not a constant expression");
6479 0 : return false;
6480 : }
6481 : else
6482 : {
6483 0 : want_rval = true;
6484 0 : return RECUR (TREE_OPERAND (t, 0), want_rval);
6485 : }
6486 : }
6487 :
6488 0 : case COMPOUND_EXPR:
6489 0 : {
6490 : /* check_return_expr sometimes wraps a TARGET_EXPR in a
6491 : COMPOUND_EXPR; don't get confused. */
6492 0 : tree op0 = TREE_OPERAND (t, 0);
6493 0 : tree op1 = TREE_OPERAND (t, 1);
6494 0 : STRIP_NOPS (op1);
6495 0 : if (TREE_CODE (op0) == TARGET_EXPR && op1 == TARGET_EXPR_SLOT (op0))
6496 0 : return RECUR (op0, want_rval);
6497 : else
6498 0 : goto binary;
6499 : }
6500 :
6501 : /* If the first operand is the non-short-circuit constant, look at
6502 : the second operand; otherwise we only care about the first one for
6503 : potentiality. */
6504 0 : case TRUTH_AND_EXPR:
6505 0 : case TRUTH_ANDIF_EXPR:
6506 0 : tmp = boolean_true_node;
6507 0 : goto truth;
6508 0 : case TRUTH_OR_EXPR:
6509 0 : case TRUTH_ORIF_EXPR:
6510 0 : tmp = boolean_false_node;
6511 0 : truth:
6512 0 : {
6513 0 : tree op0 = TREE_OPERAND (t, 0);
6514 0 : tree op1 = TREE_OPERAND (t, 1);
6515 0 : if (!RECUR (op0, rval))
6516 : return false;
6517 0 : if (!(flags & tf_error) && RECUR (op1, rval))
6518 : /* When quiet, try to avoid expensive trial evaluation by first
6519 : checking potentiality of the second operand. */
6520 : return true;
6521 0 : op0 = cxx_eval_outermost_constant_expr (op0, true);
6522 0 : if (tree_int_cst_equal (op0, tmp))
6523 0 : return (flags & tf_error) ? RECUR (op1, rval) : false;
6524 : else
6525 : return true;
6526 : }
6527 :
6528 : case PLUS_EXPR:
6529 : case MULT_EXPR:
6530 : case POINTER_PLUS_EXPR:
6531 : case RDIV_EXPR:
6532 : case EXACT_DIV_EXPR:
6533 : case MIN_EXPR:
6534 : case MAX_EXPR:
6535 : case LSHIFT_EXPR:
6536 : case RSHIFT_EXPR:
6537 : case LROTATE_EXPR:
6538 : case RROTATE_EXPR:
6539 : case BIT_IOR_EXPR:
6540 : case BIT_XOR_EXPR:
6541 : case BIT_AND_EXPR:
6542 : case TRUTH_XOR_EXPR:
6543 : case UNORDERED_EXPR:
6544 : case ORDERED_EXPR:
6545 : case UNLT_EXPR:
6546 : case UNLE_EXPR:
6547 : case UNGT_EXPR:
6548 : case UNGE_EXPR:
6549 : case UNEQ_EXPR:
6550 : case LTGT_EXPR:
6551 : case RANGE_EXPR:
6552 : case COMPLEX_EXPR:
6553 0 : want_rval = true;
6554 : /* Fall through. */
6555 0 : case ARRAY_REF:
6556 0 : case ARRAY_RANGE_REF:
6557 0 : case MEMBER_REF:
6558 0 : case DOTSTAR_EXPR:
6559 0 : case MEM_REF:
6560 0 : case BINARY_LEFT_FOLD_EXPR:
6561 0 : case BINARY_RIGHT_FOLD_EXPR:
6562 0 : binary:
6563 0 : for (i = 0; i < 2; ++i)
6564 0 : if (!RECUR (TREE_OPERAND (t, i), want_rval))
6565 : return false;
6566 : return true;
6567 :
6568 : case VEC_PERM_EXPR:
6569 0 : for (i = 0; i < 3; ++i)
6570 0 : if (!RECUR (TREE_OPERAND (t, i), true))
6571 : return false;
6572 : return true;
6573 :
6574 0 : case COND_EXPR:
6575 0 : if (COND_EXPR_IS_VEC_DELETE (t))
6576 : {
6577 0 : if (flags & tf_error)
6578 0 : error_at (loc, "%<delete[]%> is not a constant expression");
6579 0 : return false;
6580 : }
6581 : /* Fall through. */
6582 0 : case IF_STMT:
6583 0 : case VEC_COND_EXPR:
6584 : /* If the condition is a known constant, we know which of the legs we
6585 : care about; otherwise we only require that the condition and
6586 : either of the legs be potentially constant. */
6587 0 : tmp = TREE_OPERAND (t, 0);
6588 0 : if (!RECUR (tmp, rval))
6589 : return false;
6590 :
6591 0 : tmp = cxx_eval_outermost_constant_expr (tmp, true);
6592 : /* potential_constant_expression* isn't told if it is called for
6593 : manifestly_const_eval or not, so for consteval if always
6594 : process both branches as if the condition is not a known
6595 : constant. */
6596 0 : if (TREE_CODE (t) != IF_STMT || !IF_STMT_CONSTEVAL_P (t))
6597 : {
6598 0 : if (integer_zerop (tmp))
6599 0 : return RECUR (TREE_OPERAND (t, 2), want_rval);
6600 0 : else if (TREE_CODE (tmp) == INTEGER_CST)
6601 0 : return RECUR (TREE_OPERAND (t, 1), want_rval);
6602 : }
6603 0 : tmp = *jump_target;
6604 0 : for (i = 1; i < 3; ++i)
6605 : {
6606 0 : tree this_jump_target = tmp;
6607 0 : if (potential_constant_expression_1 (TREE_OPERAND (t, i), want_rval,
6608 : strict, now, tf_none,
6609 : &this_jump_target))
6610 : {
6611 0 : if (returns (&this_jump_target))
6612 0 : *jump_target = this_jump_target;
6613 0 : else if (!returns (jump_target))
6614 : {
6615 0 : if (breaks (&this_jump_target)
6616 0 : || continues (&this_jump_target))
6617 0 : *jump_target = this_jump_target;
6618 0 : if (i == 1)
6619 : {
6620 : /* If the then branch is potentially constant, but
6621 : does not return, check if the else branch
6622 : couldn't return, break or continue. */
6623 0 : hash_set<tree> pset;
6624 0 : check_for_return_continue_data data
6625 0 : = {&pset, NULL_TREE, NULL_TREE};
6626 0 : if (tree ret_expr
6627 0 : = rs_walk_tree (&TREE_OPERAND (t, 2),
6628 : check_for_return_continue, &data,
6629 : &pset))
6630 0 : *jump_target = ret_expr;
6631 0 : else if (*jump_target == NULL_TREE)
6632 : {
6633 0 : if (data.continue_stmt)
6634 0 : *jump_target = data.continue_stmt;
6635 0 : else if (data.break_stmt)
6636 0 : *jump_target = data.break_stmt;
6637 : }
6638 0 : }
6639 : }
6640 0 : return true;
6641 : }
6642 : }
6643 0 : if (flags & tf_error)
6644 0 : error_at (loc, "expression %qE is not a constant expression", t);
6645 : return false;
6646 :
6647 : case TYPE_DECL:
6648 : /* We can see these in statement-expressions. */
6649 : return true;
6650 :
6651 0 : case LABEL_EXPR:
6652 0 : t = LABEL_EXPR_LABEL (t);
6653 0 : if (DECL_ARTIFICIAL (t))
6654 : return true;
6655 0 : else if (flags & tf_error)
6656 0 : error_at (loc, "label definition in %<constexpr%> function only "
6657 : "available with %<-std=c++2b%> or %<-std=gnu++2b%>");
6658 : return false;
6659 :
6660 0 : case ANNOTATE_EXPR:
6661 0 : return RECUR (TREE_OPERAND (t, 0), rval);
6662 :
6663 0 : case BIT_CAST_EXPR:
6664 0 : return RECUR (TREE_OPERAND (t, 0), rval);
6665 :
6666 0 : default:
6667 0 : sorry ("unexpected AST of kind %s", get_tree_code_name (TREE_CODE (t)));
6668 0 : rust_unreachable ();
6669 : return false;
6670 : }
6671 : #undef RECUR
6672 : }
6673 :
6674 : bool
6675 0 : potential_constant_expression_1 (tree t, bool want_rval, bool strict, bool now,
6676 : tsubst_flags_t flags)
6677 : {
6678 0 : if (flags & tf_error)
6679 : {
6680 : /* Check potentiality quietly first, as that could be performed more
6681 : efficiently in some cases (currently only for TRUTH_*_EXPR). If
6682 : that fails, replay the check noisily to give errors. */
6683 0 : flags &= ~tf_error;
6684 0 : if (potential_constant_expression_1 (t, want_rval, strict, now, flags))
6685 : return true;
6686 0 : flags |= tf_error;
6687 : }
6688 :
6689 0 : tree target = NULL_TREE;
6690 0 : return potential_constant_expression_1 (t, want_rval, strict, now, flags,
6691 0 : &target);
6692 : }
6693 :
6694 : // forked from gcc/cp/constexpr.cc fold_non_dependent_init
6695 :
6696 : /* Like maybe_constant_init but first fully instantiate the argument. */
6697 :
6698 : tree
6699 0 : fold_non_dependent_init (tree t, tsubst_flags_t /*=tf_warning_or_error*/,
6700 : bool manifestly_const_eval /*=false*/,
6701 : tree object /* = NULL_TREE */)
6702 : {
6703 0 : if (t == NULL_TREE)
6704 : return NULL_TREE;
6705 :
6706 0 : return maybe_constant_init (t, object, manifestly_const_eval);
6707 : }
6708 :
6709 : /* Check whether the shift operation with code CODE and type TYPE on LHS
6710 : and RHS is undefined. If it is, give an error with an explanation,
6711 : and return true; return false otherwise. */
6712 :
6713 : static bool
6714 42 : eval_check_shift_p (location_t loc, const constexpr_ctx *ctx,
6715 : enum tree_code code, tree type, tree lhs, tree rhs)
6716 : {
6717 42 : if ((code != LSHIFT_EXPR && code != RSHIFT_EXPR)
6718 0 : || TREE_CODE (lhs) != INTEGER_CST || TREE_CODE (rhs) != INTEGER_CST)
6719 : return false;
6720 :
6721 0 : tree lhstype = TREE_TYPE (lhs);
6722 0 : unsigned HOST_WIDE_INT uprec = TYPE_PRECISION (TREE_TYPE (lhs));
6723 :
6724 : /* [expr.shift] The behavior is undefined if the right operand
6725 : is negative, or greater than or equal to the length in bits
6726 : of the promoted left operand. */
6727 0 : if (tree_int_cst_sgn (rhs) == -1)
6728 : {
6729 0 : if (!ctx->quiet)
6730 0 : permerror (loc, "right operand of shift expression %q+E is negative",
6731 : build2_loc (loc, code, type, lhs, rhs));
6732 0 : return (!flag_permissive || ctx->quiet);
6733 : }
6734 0 : if (compare_tree_int (rhs, uprec) >= 0)
6735 : {
6736 0 : if (!ctx->quiet)
6737 0 : permerror (loc,
6738 : "right operand of shift expression %q+E is greater "
6739 : "than or equal to the precision %wu of the left operand",
6740 : build2_loc (loc, code, type, lhs, rhs), uprec);
6741 0 : return (!flag_permissive || ctx->quiet);
6742 : }
6743 :
6744 : /* The value of E1 << E2 is E1 left-shifted E2 bit positions; [...]
6745 : if E1 has a signed type and non-negative value, and E1x2^E2 is
6746 : representable in the corresponding unsigned type of the result type,
6747 : then that value, converted to the result type, is the resulting value;
6748 : otherwise, the behavior is undefined.
6749 : For C++20:
6750 : The value of E1 << E2 is the unique value congruent to E1 x 2^E2 modulo
6751 : 2^N, where N is the range exponent of the type of the result. */
6752 0 : if (code == LSHIFT_EXPR && !TYPE_OVERFLOW_WRAPS (lhstype))
6753 : {
6754 0 : if (tree_int_cst_sgn (lhs) == -1)
6755 : {
6756 0 : if (!ctx->quiet)
6757 0 : permerror (loc, "left operand of shift expression %q+E is negative",
6758 : build2_loc (loc, code, type, lhs, rhs));
6759 0 : return (!flag_permissive || ctx->quiet);
6760 : }
6761 : /* For signed x << y the following:
6762 : (unsigned) x >> ((prec (lhs) - 1) - y)
6763 : if > 1, is undefined. The right-hand side of this formula
6764 : is the highest bit of the LHS that can be set (starting from 0),
6765 : so that the shift doesn't overflow. We then right-shift the LHS
6766 : to see whether any other bit is set making the original shift
6767 : undefined -- the result is not representable in the corresponding
6768 : unsigned type. */
6769 0 : tree t = build_int_cst (unsigned_type_node, uprec - 1);
6770 0 : t = fold_build2 (MINUS_EXPR, unsigned_type_node, t, rhs);
6771 0 : tree ulhs = fold_convert (unsigned_type_for (lhstype), lhs);
6772 0 : t = fold_build2 (RSHIFT_EXPR, TREE_TYPE (ulhs), ulhs, t);
6773 0 : if (tree_int_cst_lt (integer_one_node, t))
6774 : {
6775 0 : if (!ctx->quiet)
6776 0 : permerror (loc, "shift expression %q+E overflows",
6777 : build2_loc (loc, code, type, lhs, rhs));
6778 0 : return (!flag_permissive || ctx->quiet);
6779 : }
6780 : }
6781 : return false;
6782 : }
6783 :
6784 : /* Helper function for cxx_eval_binary_expression. Try to optimize
6785 : original POINTER_PLUS_EXPR T, LHS p+ RHS, return NULL_TREE if the
6786 : generic folding should be used. */
6787 :
6788 : static tree
6789 0 : fold_pointer_plus_expression (const constexpr_ctx *ctx, tree t, tree lhs,
6790 : tree rhs, bool *non_constant_p, bool *overflow_p,
6791 : tree *jump_target)
6792 : {
6793 0 : STRIP_NOPS (lhs);
6794 0 : if (TREE_CODE (lhs) != ADDR_EXPR)
6795 : return NULL_TREE;
6796 :
6797 0 : lhs = TREE_OPERAND (lhs, 0);
6798 :
6799 : /* &A[i] p+ j => &A[i + j] */
6800 0 : if (TREE_CODE (lhs) == ARRAY_REF
6801 0 : && TREE_CODE (TREE_OPERAND (lhs, 1)) == INTEGER_CST
6802 0 : && TREE_CODE (rhs) == INTEGER_CST && TYPE_SIZE_UNIT (TREE_TYPE (lhs))
6803 0 : && TREE_CODE (TYPE_SIZE_UNIT (TREE_TYPE (lhs))) == INTEGER_CST)
6804 : {
6805 0 : tree orig_type = TREE_TYPE (t);
6806 0 : location_t loc = EXPR_LOCATION (t);
6807 0 : tree type = TREE_TYPE (lhs);
6808 :
6809 0 : t = fold_convert_loc (loc, ssizetype, TREE_OPERAND (lhs, 1));
6810 0 : tree nelts = array_type_nelts_top (TREE_TYPE (TREE_OPERAND (lhs, 0)));
6811 0 : nelts = eval_constant_expression (ctx, nelts, true, non_constant_p,
6812 : overflow_p, jump_target);
6813 0 : if (*non_constant_p)
6814 : return NULL_TREE;
6815 0 : if (*jump_target)
6816 : return NULL_TREE;
6817 : /* Don't fold an out-of-bound access. */
6818 0 : if (!tree_int_cst_le (t, nelts))
6819 : return NULL_TREE;
6820 0 : rhs = fold_convert (ssizetype, rhs);
6821 : /* Don't fold if rhs can't be divided exactly by TYPE_SIZE_UNIT.
6822 : constexpr int A[1]; ... (char *)&A[0] + 1 */
6823 0 : if (!integer_zerop (fold_build2_loc (loc, TRUNC_MOD_EXPR, sizetype, rhs,
6824 0 : TYPE_SIZE_UNIT (type))))
6825 : return NULL_TREE;
6826 : /* Make sure to treat the second operand of POINTER_PLUS_EXPR
6827 : as signed. */
6828 0 : rhs = fold_build2_loc (loc, EXACT_DIV_EXPR, ssizetype, rhs,
6829 0 : TYPE_SIZE_UNIT (type));
6830 0 : t = size_binop_loc (loc, PLUS_EXPR, rhs, t);
6831 0 : t = build4_loc (loc, ARRAY_REF, type, TREE_OPERAND (lhs, 0), t, NULL_TREE,
6832 : NULL_TREE);
6833 0 : t = build_fold_addr_expr (t);
6834 0 : t = fold_convert (orig_type, t);
6835 0 : return eval_constant_expression (ctx, t, true, non_constant_p, overflow_p,
6836 0 : jump_target);
6837 : }
6838 :
6839 : return NULL_TREE;
6840 : }
6841 :
6842 : /* Try to fold expressions like
6843 : (struct S *) (&a[0].D.2378 + 12)
6844 : into
6845 : &MEM <struct T> [(void *)&a + 12B]
6846 : This is something normally done by gimple_fold_stmt_to_constant_1
6847 : on GIMPLE, but is undesirable on GENERIC if we are e.g. going to
6848 : dereference the address because some details are lost.
6849 : For pointer comparisons we want such folding though so that
6850 : match.pd address_compare optimization works. */
6851 :
6852 : static tree
6853 0 : maybe_fold_addr_pointer_plus (tree t)
6854 : {
6855 0 : while (CONVERT_EXPR_P (t) && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (t, 0))))
6856 0 : t = TREE_OPERAND (t, 0);
6857 0 : if (TREE_CODE (t) != POINTER_PLUS_EXPR)
6858 : return NULL_TREE;
6859 0 : tree op0 = TREE_OPERAND (t, 0);
6860 0 : tree op1 = TREE_OPERAND (t, 1);
6861 0 : if (TREE_CODE (op1) != INTEGER_CST)
6862 : return NULL_TREE;
6863 0 : while (CONVERT_EXPR_P (op0)
6864 0 : && POINTER_TYPE_P (TREE_TYPE (TREE_OPERAND (op0, 0))))
6865 0 : op0 = TREE_OPERAND (op0, 0);
6866 0 : if (TREE_CODE (op0) != ADDR_EXPR)
6867 : return NULL_TREE;
6868 0 : op1 = fold_convert (ptr_type_node, op1);
6869 0 : tree r = fold_build2 (MEM_REF, TREE_TYPE (TREE_TYPE (op0)), op0, op1);
6870 0 : return build1_loc (EXPR_LOCATION (t), ADDR_EXPR, TREE_TYPE (op0), r);
6871 : }
6872 :
6873 : } // namespace Compile
6874 : } // namespace Rust
6875 :
6876 : using namespace Rust::Compile;
6877 :
6878 : #include "gt-rust-rust-constexpr.h"
|
