Line data Source code
1 : /* Perform the semantic phase of lambda parsing, i.e., the process of
2 : building tree structure, checking semantic consistency, and
3 : building RTL. These routines are used both during actual parsing
4 : and during the instantiation of template functions.
5 :
6 : Copyright (C) 1998-2026 Free Software Foundation, Inc.
7 :
8 : This file is part of GCC.
9 :
10 : GCC is free software; you can redistribute it and/or modify it
11 : under the terms of the GNU General Public License as published by
12 : the Free Software Foundation; either version 3, or (at your option)
13 : any later version.
14 :
15 : GCC is distributed in the hope that it will be useful, but
16 : WITHOUT ANY WARRANTY; without even the implied warranty of
17 : MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 : General Public License for more details.
19 :
20 : You should have received a copy of the GNU General Public License
21 : along with GCC; see the file COPYING3. If not see
22 : <http://www.gnu.org/licenses/>. */
23 :
24 : #include "config.h"
25 : #include "system.h"
26 : #include "coretypes.h"
27 : #include "cp-tree.h"
28 : #include "stringpool.h"
29 : #include "cgraph.h"
30 : #include "tree-iterator.h"
31 : #include "toplev.h"
32 : #include "gimplify.h"
33 : #include "target.h"
34 : #include "decl.h"
35 : #include "flags.h"
36 : #include "contracts.h"
37 :
38 : /* Constructor for a lambda expression. */
39 :
40 : tree
41 1773921 : build_lambda_expr (void)
42 : {
43 1773921 : tree lambda = make_node (LAMBDA_EXPR);
44 1773921 : LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (lambda) = CPLD_NONE;
45 1773921 : LAMBDA_EXPR_CAPTURE_LIST (lambda) = NULL_TREE;
46 1773921 : LAMBDA_EXPR_THIS_CAPTURE (lambda) = NULL_TREE;
47 1773921 : LAMBDA_EXPR_REGEN_INFO (lambda) = NULL_TREE;
48 1773921 : LAMBDA_EXPR_PENDING_PROXIES (lambda) = NULL;
49 1773921 : return lambda;
50 : }
51 :
52 : /* Create the closure object for a LAMBDA_EXPR. */
53 :
54 : tree
55 1773980 : build_lambda_object (tree lambda_expr)
56 : {
57 : /* Build aggregate constructor call.
58 : - cp_parser_braced_list
59 : - cp_parser_functional_cast */
60 1773980 : vec<constructor_elt, va_gc> *elts = NULL;
61 1773980 : tree node, expr, type;
62 :
63 1773980 : if (processing_template_decl && !in_template_context
64 75 : && current_binding_level->requires_expression)
65 : /* As in cp_parser_lambda_expression, don't get confused by
66 : cp_parser_requires_expression setting processing_template_decl. In that
67 : case we want to return the result of finish_compound_literal, to avoid
68 : tsubst_lambda_expr. */;
69 1773965 : else if (processing_template_decl || lambda_expr == error_mark_node)
70 : return lambda_expr;
71 :
72 : /* Make sure any error messages refer to the lambda-introducer. */
73 678631 : location_t loc = LAMBDA_EXPR_LOCATION (lambda_expr);
74 678631 : iloc_sentinel il (loc);
75 :
76 678631 : for (node = LAMBDA_EXPR_CAPTURE_LIST (lambda_expr);
77 2122546 : node;
78 1443915 : node = TREE_CHAIN (node))
79 : {
80 1443915 : tree field = TREE_PURPOSE (node);
81 1443915 : tree val = TREE_VALUE (node);
82 :
83 1443915 : if (field == error_mark_node)
84 : {
85 0 : expr = error_mark_node;
86 0 : goto out;
87 : }
88 :
89 1443915 : if (TREE_CODE (val) == TREE_LIST)
90 0 : val = build_x_compound_expr_from_list (val, ELK_INIT,
91 : tf_warning_or_error);
92 :
93 1443915 : if (DECL_P (val))
94 859270 : mark_used (val);
95 :
96 : /* Mere mortals can't copy arrays with aggregate initialization, so
97 : do some magic to make it work here. */
98 1443915 : if (TREE_CODE (TREE_TYPE (field)) == ARRAY_TYPE)
99 19 : val = build_array_copy (val);
100 1443896 : else if (DECL_NORMAL_CAPTURE_P (field)
101 1442896 : && !DECL_VLA_CAPTURE_P (field)
102 2886750 : && !TYPE_REF_P (TREE_TYPE (field)))
103 : {
104 : /* "the entities that are captured by copy are used to
105 : direct-initialize each corresponding non-static data
106 : member of the resulting closure object."
107 :
108 : There's normally no way to express direct-initialization
109 : from an element of a CONSTRUCTOR, so we build up a special
110 : TARGET_EXPR to bypass the usual copy-initialization. */
111 343551 : val = force_rvalue (val, tf_warning_or_error);
112 343551 : if (TREE_CODE (val) == TARGET_EXPR)
113 737 : TARGET_EXPR_DIRECT_INIT_P (val) = true;
114 : }
115 :
116 1443915 : CONSTRUCTOR_APPEND_ELT (elts, DECL_NAME (field), val);
117 : }
118 :
119 678631 : expr = build_constructor (init_list_type_node, elts);
120 678631 : CONSTRUCTOR_IS_DIRECT_INIT (expr) = 1;
121 :
122 : /* N2927: "[The closure] class type is not an aggregate."
123 : But we briefly treat it as an aggregate to make this simpler. */
124 678631 : type = LAMBDA_EXPR_CLOSURE (lambda_expr);
125 678631 : CLASSTYPE_NON_AGGREGATE (type) = 0;
126 678631 : expr = finish_compound_literal (type, expr, tf_warning_or_error);
127 678631 : protected_set_expr_location (expr, loc);
128 678631 : CLASSTYPE_NON_AGGREGATE (type) = 1;
129 :
130 678631 : out:
131 678631 : return expr;
132 678631 : }
133 :
134 : /* Return an initialized RECORD_TYPE for LAMBDA.
135 : LAMBDA must have its explicit captures already. */
136 :
137 : tree
138 1773912 : begin_lambda_type (tree lambda)
139 : {
140 : /* Lambda names are nearly but not quite anonymous. */
141 1773912 : tree name = make_anon_name ();
142 1773912 : IDENTIFIER_LAMBDA_P (name) = true;
143 :
144 : /* Create the new RECORD_TYPE for this lambda. */
145 1773912 : tree type = xref_tag (/*tag_code=*/record_type, name);
146 1773912 : if (type == error_mark_node)
147 : return error_mark_node;
148 :
149 : /* Designate it as a struct so that we can use aggregate initialization. */
150 1773912 : CLASSTYPE_DECLARED_CLASS (type) = false;
151 :
152 : /* Cross-reference the expression and the type. */
153 1773912 : LAMBDA_EXPR_CLOSURE (lambda) = type;
154 1773912 : SET_CLASSTYPE_LAMBDA_EXPR (type, lambda);
155 :
156 : /* In C++17, assume the closure is literal; we'll clear the flag later if
157 : necessary. */
158 1773912 : if (cxx_dialect >= cxx17)
159 1770165 : CLASSTYPE_LITERAL_P (type) = true;
160 :
161 : /* Clear base types. */
162 1773912 : xref_basetypes (type, /*bases=*/NULL_TREE);
163 :
164 : /* Start the class. */
165 1773912 : type = begin_class_definition (type);
166 :
167 1773912 : return type;
168 : }
169 :
170 : /* Given a LAMBDA_EXPR or closure type LAMBDA, return the op() of the
171 : closure type. */
172 :
173 : tree
174 18070056 : lambda_function (tree lambda)
175 : {
176 18070056 : tree type;
177 18070056 : if (TREE_CODE (lambda) == LAMBDA_EXPR)
178 7028282 : type = LAMBDA_EXPR_CLOSURE (lambda);
179 : else
180 : type = lambda;
181 36140112 : gcc_assert (LAMBDA_TYPE_P (type));
182 : /* Don't let debug_tree cause instantiation. */
183 18070056 : if (CLASSTYPE_TEMPLATE_INSTANTIATION (type)
184 18070056 : && !COMPLETE_OR_OPEN_TYPE_P (type))
185 : return NULL_TREE;
186 18070056 : lambda = get_class_binding_direct (type, call_op_identifier);
187 18070056 : if (lambda)
188 18070025 : lambda = STRIP_TEMPLATE (get_first_fn (lambda));
189 : return lambda;
190 : }
191 :
192 : /* True if EXPR is an expression whose type can be used directly in lambda
193 : capture. Not to be used for 'auto'. */
194 :
195 : static bool
196 2076082 : type_deducible_expression_p (tree expr)
197 : {
198 2076082 : if (!type_dependent_expression_p (expr))
199 : return true;
200 0 : if (BRACE_ENCLOSED_INITIALIZER_P (expr)
201 1090767 : || TREE_CODE (expr) == EXPR_PACK_EXPANSION)
202 : return false;
203 1090767 : tree t = non_reference (TREE_TYPE (expr));
204 1090767 : return (t && TREE_CODE (t) != TYPE_PACK_EXPANSION
205 467146 : && !WILDCARD_TYPE_P (t) && !LAMBDA_TYPE_P (t)
206 554825 : && !array_of_unknown_bound_p (t)
207 1645567 : && !type_uses_auto (t));
208 : }
209 :
210 : /* Returns the type to use for the FIELD_DECL corresponding to the
211 : capture of EXPR. EXPLICIT_INIT_P indicates whether this is a
212 : C++14 init capture, and BY_REFERENCE_P indicates whether we're
213 : capturing by reference. */
214 :
215 : tree
216 2088485 : lambda_capture_field_type (tree expr, bool explicit_init_p,
217 : bool by_reference_p)
218 : {
219 2088485 : tree type;
220 2088485 : bool is_this = is_this_parameter (tree_strip_nop_conversions (expr));
221 :
222 2088485 : if (explicit_init_p)
223 : {
224 12403 : if (uses_parameter_packs (expr))
225 : {
226 : /* Stick with 'auto...' even if the type could be deduced. */
227 174 : type = make_auto_pack ();
228 174 : if (by_reference_p)
229 73 : type = build_reference_type (type);
230 : }
231 : else
232 : {
233 12229 : tree auto_node = make_auto ();
234 12229 : type = auto_node;
235 12229 : if (by_reference_p)
236 : /* Add the reference now, so deduction doesn't lose
237 : outermost CV qualifiers of EXPR. */
238 53 : type = build_reference_type (type);
239 12229 : type = do_auto_deduction (type, expr, auto_node);
240 : }
241 : }
242 2076082 : else if (!type_deducible_expression_p (expr))
243 : {
244 535970 : type = cxx_make_type (DECLTYPE_TYPE);
245 535970 : DECLTYPE_TYPE_EXPR (type) = expr;
246 535970 : DECLTYPE_FOR_LAMBDA_CAPTURE (type) = true;
247 535970 : DECLTYPE_FOR_REF_CAPTURE (type) = by_reference_p;
248 535970 : SET_TYPE_STRUCTURAL_EQUALITY (type);
249 : }
250 : else
251 : {
252 1540112 : STRIP_ANY_LOCATION_WRAPPER (expr);
253 :
254 1540112 : if (!by_reference_p && is_capture_proxy (expr))
255 : {
256 : /* When capturing by-value another capture proxy from an enclosing
257 : lambda, consider the type of the corresponding field instead,
258 : as the proxy may be additionally const-qualifed if the enclosing
259 : lambda is non-mutable (PR94376). */
260 227 : gcc_assert (TREE_CODE (DECL_VALUE_EXPR (expr)) == COMPONENT_REF);
261 227 : expr = TREE_OPERAND (DECL_VALUE_EXPR (expr), 1);
262 : }
263 :
264 1540112 : type = non_reference (unlowered_expr_type (expr));
265 :
266 1540112 : if ((by_reference_p && !is_this) || TREE_CODE (type) == FUNCTION_TYPE)
267 954663 : type = build_reference_type (type);
268 : }
269 :
270 2088485 : return type;
271 : }
272 :
273 : /* Returns true iff DECL is a lambda capture proxy variable created by
274 : build_capture_proxy. */
275 :
276 : bool
277 5759233454 : is_capture_proxy (tree decl)
278 : {
279 : /* Location wrappers should be stripped or otherwise handled by the
280 : caller before using this predicate. */
281 5759233454 : gcc_checking_assert (!location_wrapper_p (decl));
282 :
283 5759233454 : return (VAR_P (decl)
284 1682166291 : && DECL_HAS_VALUE_EXPR_P (decl)
285 62789141 : && !DECL_ANON_UNION_VAR_P (decl)
286 62786896 : && !DECL_DECOMPOSITION_P (decl)
287 59105071 : && !DECL_FNAME_P (decl)
288 58781741 : && !(DECL_ARTIFICIAL (decl)
289 58780021 : && DECL_LANG_SPECIFIC (decl)
290 57874660 : && DECL_OMP_PRIVATIZED_MEMBER (decl))
291 5876759307 : && LAMBDA_FUNCTION_P (DECL_CONTEXT (decl)));
292 : }
293 :
294 : /* Returns true iff DECL is a capture proxy for a normal capture
295 : (i.e. without explicit initializer). */
296 :
297 : bool
298 5587602586 : is_normal_capture_proxy (tree decl)
299 : {
300 5587602586 : if (!is_capture_proxy (decl))
301 : /* It's not a capture proxy. */
302 : return false;
303 :
304 47423114 : return (DECL_LANG_SPECIFIC (decl)
305 47423114 : && DECL_CAPTURED_VARIABLE (decl));
306 : }
307 :
308 : /* If DECL is a normal capture proxy, return the variable it captures.
309 : Otherwise, just return DECL. */
310 :
311 : tree
312 6610939 : strip_normal_capture_proxy (tree decl)
313 : {
314 6644310 : while (is_normal_capture_proxy (decl))
315 33371 : decl = DECL_CAPTURED_VARIABLE (decl);
316 6610939 : return decl;
317 : }
318 :
319 : /* Returns true iff DECL is a capture proxy for a normal capture
320 : of a constant variable. */
321 :
322 : bool
323 17393 : is_constant_capture_proxy (tree decl)
324 : {
325 17393 : if (is_normal_capture_proxy (decl))
326 2195 : return decl_constant_var_p (DECL_CAPTURED_VARIABLE (decl));
327 : return false;
328 : }
329 :
330 : /* VAR is a capture proxy created by build_capture_proxy; add it to the
331 : current function, which is the operator() for the appropriate lambda. */
332 :
333 : void
334 3654438 : insert_capture_proxy (tree var)
335 : {
336 3654438 : if (is_normal_capture_proxy (var))
337 : {
338 3641292 : tree cap = DECL_CAPTURED_VARIABLE (var);
339 3641292 : if (CHECKING_P)
340 : {
341 3641292 : gcc_assert (!is_normal_capture_proxy (cap));
342 3641292 : tree old = retrieve_local_specialization (cap);
343 3641292 : if (old)
344 14796 : gcc_assert (DECL_CONTEXT (old) != DECL_CONTEXT (var));
345 : }
346 3641292 : register_local_specialization (var, cap);
347 : }
348 :
349 : /* Put the capture proxy in the extra body block so that it won't clash
350 : with a later local variable. */
351 3654438 : pushdecl_outermost_localscope (var);
352 :
353 : /* And put a DECL_EXPR in the STATEMENT_LIST for the same block. */
354 3654438 : var = build_stmt (DECL_SOURCE_LOCATION (var), DECL_EXPR, var);
355 : /* The first stmt_list is from start_preparsed_function. Then there's a
356 : possible stmt_list from begin_eh_spec_block, then the one from the
357 : lambda's outer {}. */
358 3654438 : unsigned index = 1 + use_eh_spec_block (current_function_decl);
359 3654438 : tree stmt_list = (*stmt_list_stack)[index];
360 3654438 : gcc_assert (stmt_list);
361 3654438 : append_to_statement_list_force (var, &stmt_list);
362 3654438 : }
363 :
364 : /* We've just finished processing a lambda; if the containing scope is also
365 : a lambda, insert any capture proxies that were created while processing
366 : the nested lambda. */
367 :
368 : void
369 1773912 : insert_pending_capture_proxies (void)
370 : {
371 1773912 : tree lam;
372 1773912 : vec<tree, va_gc> *proxies;
373 1773912 : unsigned i;
374 :
375 1866560 : if (!current_function_decl || !LAMBDA_FUNCTION_P (current_function_decl))
376 : return;
377 :
378 17909 : lam = CLASSTYPE_LAMBDA_EXPR (DECL_CONTEXT (current_function_decl));
379 17909 : proxies = LAMBDA_EXPR_PENDING_PROXIES (lam);
380 20879 : for (i = 0; i < vec_safe_length (proxies); ++i)
381 : {
382 2970 : tree var = (*proxies)[i];
383 2970 : insert_capture_proxy (var);
384 : }
385 17909 : release_tree_vector (LAMBDA_EXPR_PENDING_PROXIES (lam));
386 17909 : LAMBDA_EXPR_PENDING_PROXIES (lam) = NULL;
387 : }
388 :
389 : /* Given REF, a COMPONENT_REF designating a field in the lambda closure,
390 : return the type we want the proxy to have: the type of the field itself,
391 : with added const-qualification if the lambda isn't mutable and the
392 : capture is by value. */
393 :
394 : tree
395 3903125 : lambda_proxy_type (tree ref)
396 : {
397 3903125 : tree type;
398 3903125 : if (ref == error_mark_node)
399 : return error_mark_node;
400 3903107 : if (REFERENCE_REF_P (ref))
401 0 : ref = TREE_OPERAND (ref, 0);
402 3903107 : gcc_assert (TREE_CODE (ref) == COMPONENT_REF);
403 3903107 : type = TREE_TYPE (ref);
404 3903107 : if (!type || WILDCARD_TYPE_P (non_reference (type)))
405 : {
406 661556 : type = cxx_make_type (DECLTYPE_TYPE);
407 661556 : DECLTYPE_TYPE_EXPR (type) = ref;
408 661556 : DECLTYPE_FOR_LAMBDA_PROXY (type) = true;
409 661556 : SET_TYPE_STRUCTURAL_EQUALITY (type);
410 : }
411 3903107 : if (DECL_PACK_P (TREE_OPERAND (ref, 1)))
412 2316 : type = make_pack_expansion (type);
413 : return type;
414 : }
415 :
416 : /* MEMBER is a capture field in a lambda closure class. Now that we're
417 : inside the operator(), build a placeholder var for future lookups and
418 : debugging. But if EARLY_P is true, we do not have the real operator()
419 : yet and we have to proceed differently. */
420 :
421 : tree
422 4735082 : build_capture_proxy (tree member, tree init, bool early_p)
423 : {
424 4735082 : tree var, object, fn, closure, name, lam, type;
425 :
426 4735082 : if (PACK_EXPANSION_P (member))
427 2298 : member = PACK_EXPANSION_PATTERN (member);
428 :
429 4735082 : closure = DECL_CONTEXT (member);
430 4735082 : fn = lambda_function (closure);
431 4735082 : lam = CLASSTYPE_LAMBDA_EXPR (closure);
432 :
433 4735082 : object = DECL_ARGUMENTS (fn);
434 : /* The proxy variable forwards to the capture field. */
435 4735082 : if (INDIRECT_TYPE_P (TREE_TYPE (object)))
436 4734940 : object = build_fold_indirect_ref (object);
437 4735082 : object = finish_non_static_data_member (member, object, NULL_TREE);
438 4735082 : if (REFERENCE_REF_P (object))
439 2785280 : object = TREE_OPERAND (object, 0);
440 :
441 : /* Remove the __ inserted by add_capture. */
442 4735082 : if (IDENTIFIER_POINTER (DECL_NAME (member))[2] == '_'
443 4735082 : && IDENTIFIER_POINTER (DECL_NAME (member))[3] == '.')
444 36 : name = get_identifier ("_");
445 : else
446 4735046 : name = get_identifier (IDENTIFIER_POINTER (DECL_NAME (member)) + 2);
447 :
448 4735082 : if (name == this_identifier && TYPE_PTR_P (TREE_TYPE (member)))
449 : /* Avoid DECLTYPE_TYPE for by-ref 'this' capture in an xobj lambda; the
450 : constness of the closure doesn't matter just like it doesn't matter to
451 : other by-ref capture. It's simpler to handle this special case here
452 : than in lambda_proxy_type. */
453 832144 : type = TREE_TYPE (member);
454 : else
455 : {
456 3902938 : type = lambda_proxy_type (object);
457 3902938 : if (name == this_identifier)
458 : {
459 266 : type = build_pointer_type (type);
460 266 : type = cp_build_qualified_type (type, TYPE_QUAL_CONST);
461 266 : object = build_fold_addr_expr_with_type (object, type);
462 : }
463 : }
464 :
465 4735082 : if (DECL_VLA_CAPTURE_P (member))
466 : {
467 : /* Rebuild the VLA type from the pointer and maxindex. */
468 78 : tree field = next_aggregate_field (TYPE_FIELDS (type));
469 78 : tree ptr = build_simple_component_ref (object, field);
470 78 : field = next_aggregate_field (DECL_CHAIN (field));
471 78 : tree max = build_simple_component_ref (object, field);
472 78 : type = build_cplus_array_type (TREE_TYPE (TREE_TYPE (ptr)),
473 : build_index_type (max));
474 78 : type = build_reference_type (type);
475 78 : object = convert (type, ptr);
476 : }
477 :
478 4735082 : complete_type (type);
479 :
480 4735082 : var = build_decl (input_location, VAR_DECL, name, type);
481 4735082 : SET_DECL_VALUE_EXPR (var, object);
482 4735082 : DECL_HAS_VALUE_EXPR_P (var) = 1;
483 4735082 : DECL_ARTIFICIAL (var) = 1;
484 4735082 : TREE_USED (var) = 1;
485 4735082 : DECL_CONTEXT (var) = fn;
486 :
487 4735082 : if (DECL_NORMAL_CAPTURE_P (member))
488 : {
489 4708958 : if (DECL_VLA_CAPTURE_P (member))
490 : {
491 72 : init = CONSTRUCTOR_ELT (init, 0)->value;
492 72 : init = TREE_OPERAND (init, 0); // Strip ADDR_EXPR.
493 72 : init = TREE_OPERAND (init, 0); // Strip ARRAY_REF.
494 : }
495 : else
496 : {
497 4708886 : if (PACK_EXPANSION_P (init))
498 1974 : init = PACK_EXPANSION_PATTERN (init);
499 : }
500 :
501 4708958 : init = strip_contract_const_wrapper (init);
502 :
503 4708958 : if (INDIRECT_REF_P (init))
504 668373 : init = TREE_OPERAND (init, 0);
505 4708958 : STRIP_NOPS (init);
506 :
507 4708958 : gcc_assert (VAR_P (init) || TREE_CODE (init) == PARM_DECL);
508 4708958 : init = strip_normal_capture_proxy (init);
509 4708958 : retrofit_lang_decl (var);
510 4708958 : DECL_CAPTURED_VARIABLE (var) = init;
511 : }
512 :
513 4735082 : if (name == this_identifier)
514 : {
515 832410 : if (early_p)
516 : return var;
517 439154 : gcc_assert (LAMBDA_EXPR_THIS_CAPTURE (lam) == member);
518 439154 : LAMBDA_EXPR_THIS_CAPTURE (lam) = var;
519 : }
520 :
521 4341826 : if (early_p)
522 : {
523 1507748 : gcc_checking_assert (current_binding_level->kind == sk_lambda);
524 : /* insert_capture_proxy below wouldn't push into the lambda scope. */
525 1507748 : pushdecl (var);
526 : }
527 2834078 : else if (fn == current_function_decl)
528 2831108 : insert_capture_proxy (var);
529 : else
530 2970 : vec_safe_push (LAMBDA_EXPR_PENDING_PROXIES (lam), var);
531 :
532 : return var;
533 : }
534 :
535 : static GTY(()) tree ptr_id;
536 : static GTY(()) tree max_id;
537 :
538 : /* Return a struct containing a pointer and a length for lambda capture of
539 : an array of runtime length. */
540 :
541 : static tree
542 45 : vla_capture_type (tree array_type)
543 : {
544 45 : tree type = xref_tag (record_type, make_anon_name ());
545 45 : xref_basetypes (type, NULL_TREE);
546 45 : type = begin_class_definition (type);
547 45 : if (!ptr_id)
548 : {
549 36 : ptr_id = get_identifier ("ptr");
550 36 : max_id = get_identifier ("max");
551 : }
552 45 : tree ptrtype = build_pointer_type (TREE_TYPE (array_type));
553 45 : tree field = build_decl (input_location, FIELD_DECL, ptr_id, ptrtype);
554 45 : finish_member_declaration (field);
555 45 : field = build_decl (input_location, FIELD_DECL, max_id, sizetype);
556 45 : finish_member_declaration (field);
557 45 : return finish_struct (type, NULL_TREE);
558 : }
559 :
560 : /* From an ID and INITIALIZER, create a capture (by reference if
561 : BY_REFERENCE_P is true), add it to the capture-list for LAMBDA,
562 : and return it. If ID is `this', BY_REFERENCE_P says whether
563 : `*this' is captured by reference. */
564 :
565 : tree
566 1638832 : add_capture (tree lambda, tree id, tree orig_init, bool by_reference_p,
567 : bool explicit_init_p, unsigned *name_independent_cnt)
568 : {
569 1638832 : char *buf;
570 1638832 : tree type, member, name;
571 1638832 : bool vla = false;
572 1638832 : bool variadic = false;
573 1638832 : tree initializer = orig_init;
574 :
575 1638832 : if (PACK_EXPANSION_P (initializer))
576 : {
577 1149 : initializer = PACK_EXPANSION_PATTERN (initializer);
578 : variadic = true;
579 : }
580 :
581 1638832 : if (TREE_CODE (initializer) == TREE_LIST
582 : /* A pack expansion might end up with multiple elements. */
583 1638832 : && !PACK_EXPANSION_P (TREE_VALUE (initializer)))
584 15 : initializer = build_x_compound_expr_from_list (initializer, ELK_INIT,
585 : tf_warning_or_error);
586 1638832 : type = TREE_TYPE (initializer);
587 1638832 : if (type == error_mark_node)
588 : return error_mark_node;
589 :
590 1638809 : if (!dependent_type_p (type) && array_of_runtime_bound_p (type))
591 : {
592 45 : vla = true;
593 45 : if (!by_reference_p)
594 3 : error ("array of runtime bound cannot be captured by copy, "
595 : "only by reference");
596 :
597 : /* For a VLA, we capture the address of the first element and the
598 : maximum index, and then reconstruct the VLA for the proxy. */
599 45 : tree elt = cp_build_array_ref (input_location, initializer,
600 : integer_zero_node, tf_warning_or_error);
601 45 : initializer = build_constructor_va (init_list_type_node, 2,
602 : NULL_TREE, build_address (elt),
603 : NULL_TREE,
604 : array_type_nelts_minus_one (type));
605 45 : type = vla_capture_type (type);
606 : }
607 1638764 : else if (!dependent_type_p (type)
608 1638764 : && variably_modified_type_p (type, NULL_TREE))
609 : {
610 18 : auto_diagnostic_group d;
611 18 : sorry ("capture of variably-modified type %qT that is not an N3639 array "
612 : "of runtime bound", type);
613 18 : if (TREE_CODE (type) == ARRAY_TYPE
614 18 : && variably_modified_type_p (TREE_TYPE (type), NULL_TREE))
615 12 : inform (input_location, "because the array element type %qT has "
616 12 : "variable size", TREE_TYPE (type));
617 18 : return error_mark_node;
618 18 : }
619 : else
620 : {
621 1638746 : type = lambda_capture_field_type (initializer, explicit_init_p,
622 : by_reference_p);
623 1638746 : if (type == error_mark_node)
624 : return error_mark_node;
625 :
626 1638743 : if (id == this_identifier && !by_reference_p)
627 : {
628 127 : gcc_assert (INDIRECT_TYPE_P (type));
629 127 : type = TREE_TYPE (type);
630 127 : initializer = cp_build_fold_indirect_ref (initializer);
631 : }
632 :
633 1638743 : if (dependent_type_p (type))
634 : ;
635 537685 : else if (id != this_identifier && by_reference_p)
636 : {
637 232166 : if (!lvalue_p (initializer))
638 : {
639 3 : error ("cannot capture %qE by reference", initializer);
640 3 : return error_mark_node;
641 : }
642 : }
643 : else
644 : {
645 : /* Capture by copy requires a complete type. */
646 305519 : type = complete_type (type);
647 305519 : if (!COMPLETE_TYPE_P (type))
648 : {
649 6 : auto_diagnostic_group d;
650 6 : error ("capture by copy of incomplete type %qT", type);
651 6 : cxx_incomplete_type_inform (type);
652 6 : return error_mark_node;
653 6 : }
654 305513 : else if (!verify_type_context (input_location,
655 : TCTX_CAPTURE_BY_COPY, type))
656 0 : return error_mark_node;
657 : }
658 :
659 1638734 : if (cxx_dialect < cxx20 && !explicit_init_p)
660 : {
661 7902 : auto_diagnostic_group d;
662 7902 : tree stripped_init = tree_strip_any_location_wrapper (initializer);
663 4166 : if (DECL_DECOMPOSITION_P (stripped_init)
664 12068 : && pedwarn (input_location, OPT_Wc__20_extensions,
665 : "captured structured bindings are a C++20 extension"))
666 179 : inform (DECL_SOURCE_LOCATION (stripped_init), "declared here");
667 7902 : }
668 : }
669 :
670 : /* Add __ to the beginning of the field name so that user code
671 : won't find the field with name lookup. We can't just leave the name
672 : unset because template instantiation uses the name to find
673 : instantiated fields. */
674 1638779 : if (id_equal (id, "_") && name_independent_cnt)
675 : {
676 48 : if (*name_independent_cnt == 0)
677 30 : name = get_identifier ("___");
678 : else
679 : {
680 : /* For 2nd and later name-independent capture use
681 : unique names. */
682 18 : char buf2[5 + (HOST_BITS_PER_INT + 2) / 3];
683 18 : sprintf (buf2, "___.%u", *name_independent_cnt);
684 18 : name = get_identifier (buf2);
685 : }
686 48 : name_independent_cnt[0]++;
687 : }
688 : else
689 : {
690 1638731 : buf = XALLOCAVEC (char, IDENTIFIER_LENGTH (id) + 3);
691 1638731 : buf[1] = buf[0] = '_';
692 1638731 : memcpy (buf + 2, IDENTIFIER_POINTER (id),
693 1638731 : IDENTIFIER_LENGTH (id) + 1);
694 1638731 : name = get_identifier (buf);
695 : }
696 :
697 1638779 : if (variadic)
698 : {
699 1149 : type = make_pack_expansion (type);
700 1149 : if (explicit_init_p)
701 : /* With an explicit initializer 'type' is auto, which isn't really a
702 : parameter pack in this context. We will want as many fields as we
703 : have elements in the expansion of the initializer, so use its packs
704 : instead. */
705 : {
706 336 : PACK_EXPANSION_PARAMETER_PACKS (type)
707 168 : = uses_parameter_packs (initializer);
708 168 : PACK_EXPANSION_AUTO_P (type) = true;
709 : }
710 : }
711 :
712 : /* Make member variable. */
713 1638779 : member = build_decl (input_location, FIELD_DECL, name, type);
714 1638779 : DECL_VLA_CAPTURE_P (member) = vla;
715 :
716 1638779 : if (!explicit_init_p)
717 : /* Normal captures are invisible to name lookup but uses are replaced
718 : with references to the capture field; we implement this by only
719 : really making them invisible in unevaluated context; see
720 : qualify_lookup. For now, let's make explicitly initialized captures
721 : always visible. */
722 1626379 : DECL_NORMAL_CAPTURE_P (member) = true;
723 :
724 1638779 : if (id == this_identifier)
725 326692 : LAMBDA_EXPR_THIS_CAPTURE (lambda) = member;
726 :
727 : /* Add it to the appropriate closure class if we've started it. */
728 1638779 : if (current_class_type
729 1638779 : && current_class_type == LAMBDA_EXPR_CLOSURE (lambda))
730 : {
731 933076 : if (COMPLETE_TYPE_P (current_class_type))
732 0 : internal_error ("trying to capture %qD in instantiation of "
733 : "generic lambda", id);
734 933076 : finish_member_declaration (member);
735 : }
736 :
737 1638779 : tree listmem = member;
738 1638779 : if (variadic)
739 : {
740 1149 : listmem = make_pack_expansion (member);
741 1149 : initializer = orig_init;
742 : }
743 1638779 : LAMBDA_EXPR_CAPTURE_LIST (lambda)
744 1638779 : = tree_cons (listmem, initializer, LAMBDA_EXPR_CAPTURE_LIST (lambda));
745 :
746 1638779 : if (LAMBDA_EXPR_CLOSURE (lambda))
747 933076 : return build_capture_proxy (member, initializer, /*early_p=*/false);
748 : /* For explicit captures we haven't started the function yet, so we wait
749 : and build the proxy from cp_parser_lambda_body. */
750 705703 : LAMBDA_CAPTURE_EXPLICIT_P (LAMBDA_EXPR_CAPTURE_LIST (lambda)) = true;
751 705703 : return NULL_TREE;
752 : }
753 :
754 : /* Register all the capture members on the list CAPTURES, which is the
755 : LAMBDA_EXPR_CAPTURE_LIST for the lambda after the introducer. */
756 :
757 : void
758 3674916 : register_capture_members (tree captures)
759 : {
760 3674916 : if (captures == NULL_TREE)
761 : return;
762 :
763 1901004 : register_capture_members (TREE_CHAIN (captures));
764 :
765 1901004 : tree field = TREE_PURPOSE (captures);
766 1901004 : if (PACK_EXPANSION_P (field))
767 1149 : field = PACK_EXPANSION_PATTERN (field);
768 :
769 1901004 : finish_member_declaration (field);
770 : }
771 :
772 : /* Similar to add_capture, except this works on a stack of nested lambdas.
773 : BY_REFERENCE_P in this case is derived from the default capture mode.
774 : Returns the capture for the lambda at the bottom of the stack. */
775 :
776 : tree
777 930124 : add_default_capture (tree lambda_stack, tree id, tree initializer)
778 : {
779 930124 : bool this_capture_p = (id == this_identifier);
780 930124 : tree var = NULL_TREE;
781 930124 : tree saved_class_type = current_class_type;
782 :
783 930124 : for (tree node = lambda_stack;
784 1863224 : node;
785 933100 : node = TREE_CHAIN (node))
786 : {
787 933100 : tree lambda = TREE_VALUE (node);
788 :
789 933100 : current_class_type = LAMBDA_EXPR_CLOSURE (lambda);
790 933100 : if (DECL_PACK_P (initializer))
791 0 : initializer = make_pack_expansion (initializer);
792 933100 : var = add_capture (lambda,
793 : id,
794 : initializer,
795 : /*by_reference_p=*/
796 : (this_capture_p
797 933100 : || (LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (lambda)
798 887202 : == CPLD_REFERENCE)),
799 : /*explicit_init_p=*/false, NULL);
800 933100 : initializer = convert_from_reference (var);
801 :
802 : /* Warn about deprecated implicit capture of this via [=]. */
803 933100 : if (cxx_dialect >= cxx20
804 927040 : && this_capture_p
805 978752 : && LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (lambda) == CPLD_COPY)
806 : {
807 62 : auto_diagnostic_group d;
808 62 : if (warning_at (LAMBDA_EXPR_LOCATION (lambda), OPT_Wdeprecated,
809 : "implicit capture of %qE via %<[=]%> is deprecated "
810 : "in C++20", this_identifier))
811 58 : inform (LAMBDA_EXPR_LOCATION (lambda), "add explicit %<this%> or "
812 : "%<*this%> capture");
813 62 : }
814 : }
815 :
816 930124 : current_class_type = saved_class_type;
817 :
818 930124 : return var;
819 : }
820 :
821 : /* Return the capture pertaining to a use of 'this' in LAMBDA, in the
822 : form of an INDIRECT_REF, possibly adding it through default
823 : capturing, if ADD_CAPTURE_P is nonzero. If ADD_CAPTURE_P is negative,
824 : try to capture but don't complain if we can't. */
825 :
826 : tree
827 1108835 : lambda_expr_this_capture (tree lambda, int add_capture_p)
828 : {
829 1108835 : tree result;
830 :
831 1108835 : tree this_capture = LAMBDA_EXPR_THIS_CAPTURE (lambda);
832 1108835 : if (this_capture)
833 998300 : if (tree spec = retrieve_local_specialization (this_capture))
834 : {
835 1955 : gcc_checking_assert (generic_lambda_fn_p (lambda_function (lambda)));
836 : this_capture = spec;
837 : }
838 :
839 : /* In unevaluated context this isn't an odr-use, so don't capture. */
840 1108835 : if (cp_unevaluated_operand)
841 122 : add_capture_p = false;
842 :
843 : /* If we captured 'this' but don't have a capture proxy yet, look up the
844 : captured 'this' again. */
845 1108835 : if (this_capture && TREE_CODE (this_capture) == FIELD_DECL)
846 : {
847 0 : gcc_assert (!add_capture_p);
848 : this_capture = NULL_TREE;
849 : }
850 :
851 : /* Try to default capture 'this' if we can. */
852 : if (!this_capture)
853 : {
854 : tree lambda_stack = NULL_TREE;
855 112270 : tree init = NULL_TREE;
856 : bool saw_complete = false;
857 :
858 : /* If we are in a lambda function, we can move out until we hit:
859 : 1. a non-lambda function or NSDMI,
860 : 2. a lambda function capturing 'this', or
861 : 3. a non-default capturing lambda function. */
862 : for (tree tlambda = lambda; ;)
863 : {
864 112270 : if (add_capture_p
865 158187 : && LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (tlambda) == CPLD_NONE)
866 : /* tlambda won't let us capture 'this'. */
867 : break;
868 :
869 112254 : if (add_capture_p)
870 45901 : lambda_stack = tree_cons (NULL_TREE,
871 : tlambda,
872 : lambda_stack);
873 :
874 112254 : tree closure = LAMBDA_EXPR_CLOSURE (tlambda);
875 112254 : if (COMPLETE_TYPE_P (closure))
876 : /* We're instantiating a generic lambda op(), the containing
877 : scope may be gone. */
878 6109 : saw_complete = true;
879 :
880 112254 : tree containing_function
881 112254 : = decl_function_context (TYPE_NAME (closure));
882 :
883 112254 : tree ex = LAMBDA_EXPR_EXTRA_SCOPE (tlambda);
884 112254 : if (ex && TREE_CODE (ex) == FIELD_DECL)
885 : {
886 : /* Lambda in an NSDMI. We don't have a function to look up
887 : 'this' in, but we can find (or rebuild) the fake one from
888 : inject_this_parameter. */
889 63 : if (!containing_function && !saw_complete)
890 : /* If we're parsing a lambda in a non-local class,
891 : we can find the fake 'this' in scope_chain. */
892 45 : init = scope_chain->x_current_class_ptr;
893 : else
894 : /* Otherwise it's either gone or buried in
895 : function_context_stack, so make another. */
896 18 : init = build_this_parm (NULL_TREE, DECL_CONTEXT (ex),
897 : TYPE_UNQUALIFIED);
898 63 : gcc_checking_assert
899 : (init && (TREE_TYPE (TREE_TYPE (init))
900 : == current_nonlambda_class_type ()));
901 : break;
902 : }
903 :
904 112191 : if (containing_function == NULL_TREE)
905 : /* We ran out of scopes; there's no 'this' to capture. */
906 : break;
907 :
908 111125 : if (!LAMBDA_FUNCTION_P (containing_function))
909 : {
910 : /* We found a non-lambda function.
911 : There is no this pointer in xobj member functions. */
912 107461 : if (DECL_IOBJ_MEMBER_FUNCTION_P (containing_function))
913 : /* First parameter is 'this'. */
914 99812 : init = DECL_ARGUMENTS (containing_function);
915 : break;
916 : }
917 :
918 1757 : tlambda
919 1757 : = CLASSTYPE_LAMBDA_EXPR (DECL_CONTEXT (containing_function));
920 :
921 1757 : if (LAMBDA_EXPR_THIS_CAPTURE (tlambda))
922 : {
923 : /* An outer lambda has already captured 'this'. */
924 : init = LAMBDA_EXPR_THIS_CAPTURE (tlambda);
925 : break;
926 : }
927 : }
928 :
929 102886 : if (init)
930 : {
931 99897 : if (add_capture_p)
932 45870 : this_capture = add_default_capture (lambda_stack,
933 : /*id=*/this_identifier,
934 : init);
935 : else
936 : this_capture = init;
937 : }
938 : }
939 :
940 1108835 : if (cp_unevaluated_operand)
941 : result = this_capture;
942 1108713 : else if (!this_capture)
943 : {
944 10626 : if (add_capture_p == 1)
945 : {
946 16 : error ("%<this%> was not captured for this lambda function");
947 16 : result = error_mark_node;
948 : }
949 : else
950 : result = NULL_TREE;
951 : }
952 : else
953 : {
954 : /* To make sure that current_class_ref is for the lambda. */
955 1098087 : gcc_assert (!current_class_ref
956 : || (TYPE_MAIN_VARIANT (TREE_TYPE (current_class_ref))
957 : == LAMBDA_EXPR_CLOSURE (lambda)));
958 :
959 1098087 : result = this_capture;
960 :
961 : /* If 'this' is captured, each use of 'this' is transformed into an
962 : access to the corresponding unnamed data member of the closure
963 : type cast (_expr.cast_ 5.4) to the type of 'this'. [ The cast
964 : ensures that the transformed expression is an rvalue. ] */
965 1098087 : result = rvalue (result);
966 : }
967 :
968 1098225 : gcc_checking_assert (!result || result == error_mark_node
969 : || TYPE_PTR_P (TREE_TYPE (result)));
970 :
971 1108835 : return result;
972 : }
973 :
974 : /* Return the innermost LAMBDA_EXPR we're currently in, if any. */
975 :
976 : tree
977 97479027 : current_lambda_expr (void)
978 : {
979 97479027 : tree type = current_class_type;
980 187004441 : while (type && !LAMBDA_TYPE_P (type))
981 41933837 : type = decl_type_context (TYPE_NAME (type));
982 97479027 : if (type)
983 5814436 : return CLASSTYPE_LAMBDA_EXPR (type);
984 : else
985 : return NULL_TREE;
986 : }
987 :
988 : /* Return the current LAMBDA_EXPR, if this is a resolvable dummy
989 : object. NULL otherwise.. */
990 :
991 : static tree
992 269132858 : resolvable_dummy_lambda (tree object)
993 : {
994 269132858 : if (!is_dummy_object (object))
995 : return NULL_TREE;
996 :
997 12742652 : tree type = TYPE_MAIN_VARIANT (TREE_TYPE (object));
998 12742652 : gcc_assert (!TYPE_PTR_P (type));
999 :
1000 12742652 : tree fn;
1001 12742652 : if (type != current_class_type
1002 9199109 : && current_class_type
1003 10340755 : && LAMBDA_TYPE_P (current_class_type)
1004 503784 : && (fn = lambda_function (current_class_type))
1005 : /* Even dummy lambdas have an operator() since P2036, but the
1006 : dummy operator() doesn't have this set. */
1007 503774 : && DECL_LAMBDA_FUNCTION_P (fn)
1008 13246423 : && DERIVED_FROM_P (type, nonlambda_method_basetype()))
1009 473601 : return CLASSTYPE_LAMBDA_EXPR (current_class_type);
1010 :
1011 : return NULL_TREE;
1012 : }
1013 :
1014 : /* We don't want to capture 'this' until we know we need it, i.e. after
1015 : overload resolution has chosen a non-static member function. At that
1016 : point we call this function to turn a dummy object into a use of the
1017 : 'this' capture. */
1018 :
1019 : tree
1020 174054252 : maybe_resolve_dummy (tree object, bool add_capture_p)
1021 : {
1022 174054252 : if (tree lam = resolvable_dummy_lambda (object))
1023 430630 : if (tree cap = lambda_expr_this_capture (lam, add_capture_p))
1024 430630 : if (cap != error_mark_node)
1025 430624 : object = build_fold_indirect_ref (cap);
1026 :
1027 174054252 : return object;
1028 : }
1029 :
1030 : /* When parsing a generic lambda containing an argument-dependent
1031 : member function call we defer overload resolution to instantiation
1032 : time. But we have to know now whether to capture this or not.
1033 : Do that if FNS contains any non-static fns as per
1034 : [expr.prim.lambda.capture]/7.1. */
1035 :
1036 : void
1037 95078606 : maybe_generic_this_capture (tree object, tree fns)
1038 : {
1039 95078606 : if (tree lam = resolvable_dummy_lambda (object))
1040 42971 : if (!LAMBDA_EXPR_THIS_CAPTURE (lam))
1041 : {
1042 : /* We've not yet captured, so look at the function set of
1043 : interest. */
1044 2820 : if (BASELINK_P (fns))
1045 2103 : fns = BASELINK_FUNCTIONS (fns);
1046 2820 : bool id_expr = TREE_CODE (fns) == TEMPLATE_ID_EXPR;
1047 2820 : if (id_expr)
1048 723 : fns = TREE_OPERAND (fns, 0);
1049 :
1050 2829 : for (lkp_iterator iter (fns); iter; ++iter)
1051 2106 : if (((!id_expr && TREE_CODE (*iter) != USING_DECL)
1052 726 : || TREE_CODE (*iter) == TEMPLATE_DECL)
1053 5655 : && DECL_OBJECT_MEMBER_FUNCTION_P (*iter))
1054 : {
1055 : /* Found a non-static member. Capture this. */
1056 2820 : lambda_expr_this_capture (lam, /*maybe*/-1);
1057 2820 : break;
1058 : }
1059 : }
1060 95078606 : }
1061 :
1062 : /* Returns the innermost non-lambda function. If ONLY_SKIP_CONSTEVAL_BLOCK_P,
1063 : we only skip lambda functions that represent consteval blocks. */
1064 :
1065 : tree
1066 224726 : current_nonlambda_function (bool only_skip_consteval_block_p/*=false*/)
1067 : {
1068 224726 : tree fn = current_function_decl;
1069 224726 : tree lam;
1070 454683 : while (fn && LAMBDA_FUNCTION_P (fn)
1071 225285 : && (!only_skip_consteval_block_p
1072 : /* Only keep going if FN represents a consteval block. */
1073 544 : || ((lam = CLASSTYPE_LAMBDA_EXPR (CP_DECL_CONTEXT (fn)))
1074 544 : && LAMBDA_EXPR_CONSTEVAL_BLOCK_P (lam))))
1075 12 : fn = decl_function_context (fn);
1076 224726 : return fn;
1077 : }
1078 :
1079 : /* Returns the method basetype of the innermost non-lambda function, including
1080 : a hypothetical constructor if inside an NSDMI, or NULL_TREE if none. */
1081 :
1082 : tree
1083 504174 : nonlambda_method_basetype (void)
1084 : {
1085 504174 : tree type = current_class_type;
1086 1008050 : if (!type || !LAMBDA_TYPE_P (type))
1087 692 : return current_class_ref ? type : NULL_TREE;
1088 :
1089 507355 : while (true)
1090 : {
1091 505569 : tree lam = CLASSTYPE_LAMBDA_EXPR (type);
1092 505569 : tree ex = LAMBDA_EXPR_EXTRA_SCOPE (lam);
1093 505569 : if (ex && TREE_CODE (ex) == FIELD_DECL)
1094 : /* Lambda in an NSDMI. */
1095 30 : return DECL_CONTEXT (ex);
1096 :
1097 505539 : tree fn = TYPE_CONTEXT (type);
1098 505539 : if (!fn || TREE_CODE (fn) != FUNCTION_DECL
1099 1008087 : || !DECL_OBJECT_MEMBER_FUNCTION_P (fn))
1100 : /* No enclosing non-lambda method. */
1101 : return NULL_TREE;
1102 496403 : if (!LAMBDA_FUNCTION_P (fn))
1103 : /* Found an enclosing non-lambda method. */
1104 492750 : return TYPE_METHOD_BASETYPE (TREE_TYPE (fn));
1105 1786 : type = DECL_CONTEXT (fn);
1106 1786 : }
1107 : }
1108 :
1109 : /* Like current_scope, but looking through lambdas. If ONLY_SKIP_CLOSURES_P,
1110 : only look through closure types. */
1111 :
1112 : tree
1113 49491359 : current_nonlambda_scope (bool only_skip_closures_p/*=false*/)
1114 : {
1115 49491359 : tree scope = current_scope ();
1116 50181990 : for (;;)
1117 : {
1118 50872454 : if (!only_skip_closures_p
1119 49768032 : && TREE_CODE (scope) == FUNCTION_DECL
1120 95053620 : && LAMBDA_FUNCTION_P (scope))
1121 : {
1122 690464 : scope = CP_TYPE_CONTEXT (DECL_CONTEXT (scope));
1123 690464 : continue;
1124 : }
1125 55937324 : else if (LAMBDA_TYPE_P (scope))
1126 : {
1127 167 : scope = CP_TYPE_CONTEXT (scope);
1128 167 : continue;
1129 : }
1130 49491359 : break;
1131 : }
1132 49491359 : return scope;
1133 : }
1134 :
1135 : /* Helper function for maybe_add_lambda_conv_op; build a CALL_EXPR with
1136 : indicated FN and NARGS, but do not initialize the return type or any of the
1137 : argument slots. */
1138 :
1139 : static tree
1140 50162 : prepare_op_call (tree fn, int nargs)
1141 : {
1142 50162 : tree t;
1143 :
1144 50162 : t = build_vl_exp (CALL_EXPR, nargs + 3);
1145 50162 : CALL_EXPR_FN (t) = fn;
1146 50162 : CALL_EXPR_STATIC_CHAIN (t) = NULL;
1147 :
1148 50162 : return t;
1149 : }
1150 :
1151 : /* Return true iff CALLOP is the op() for a generic lambda. */
1152 :
1153 : bool
1154 602246770 : generic_lambda_fn_p (tree callop)
1155 : {
1156 653247355 : return (callop && LAMBDA_FUNCTION_P (callop)
1157 7272513 : && DECL_TEMPLATE_INFO (callop)
1158 609433745 : && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (callop)));
1159 : }
1160 :
1161 : /* If the closure TYPE has a static op(), also add a conversion to function
1162 : pointer. */
1163 :
1164 : void
1165 1773866 : maybe_add_lambda_conv_op (tree type)
1166 : {
1167 1773866 : bool nested = (cfun != NULL);
1168 1773866 : bool nested_def = decl_function_context (TYPE_MAIN_DECL (type));
1169 1773866 : tree callop = lambda_function (type);
1170 1773866 : tree lam = CLASSTYPE_LAMBDA_EXPR (type);
1171 :
1172 1773866 : if (LAMBDA_EXPR_CAPTURE_LIST (lam) != NULL_TREE
1173 481960 : || LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (lam) != CPLD_NONE
1174 : /* CWG2561 ...and no explicit object parameter. */
1175 2244839 : || DECL_XOBJ_MEMBER_FUNCTION_P (callop))
1176 1663653 : return;
1177 :
1178 470843 : if (processing_template_decl)
1179 : return;
1180 :
1181 110730 : bool const generic_lambda_p = generic_lambda_fn_p (callop);
1182 :
1183 110730 : if (!generic_lambda_p && undeduced_auto_decl (callop))
1184 : {
1185 : /* If the op() wasn't deduced due to errors, give up. */
1186 34 : gcc_assert (errorcount || sorrycount);
1187 : return;
1188 : }
1189 :
1190 : /* Non-generic non-capturing lambdas only have a conversion function to
1191 : pointer to function when the trailing requires-clause's constraints are
1192 : satisfied. */
1193 110696 : if (!generic_lambda_p && !constraints_satisfied_p (callop))
1194 : return;
1195 :
1196 : /* Non-template conversion operators are defined directly with build_call_a
1197 : and using DIRECT_ARGVEC for arguments (including 'this'). Templates are
1198 : deferred and the CALL is built in-place. In the case of a deduced return
1199 : call op, the decltype expression, DECLTYPE_CALL, used as a substitute for
1200 : the return type is also built in-place. The arguments of DECLTYPE_CALL in
1201 : the return expression may differ in flags from those in the body CALL. In
1202 : particular, parameter pack expansions are marked PACK_EXPANSION_LOCAL_P in
1203 : the body CALL, but not in DECLTYPE_CALL. */
1204 :
1205 110678 : vec<tree, va_gc> *direct_argvec = 0;
1206 110678 : tree decltype_call = 0, call = 0;
1207 110678 : tree optype = TREE_TYPE (callop);
1208 110678 : tree fn_result = TREE_TYPE (optype);
1209 :
1210 110678 : tree thisarg = NULL_TREE;
1211 110678 : if (TREE_CODE (optype) == METHOD_TYPE)
1212 110418 : thisarg = build_int_cst (TREE_TYPE (DECL_ARGUMENTS (callop)), 0);
1213 110678 : if (generic_lambda_p)
1214 : {
1215 25192 : ++processing_template_decl;
1216 :
1217 : /* Prepare the dependent member call for the static member function
1218 : '_FUN' and, potentially, prepare another call to be used in a decltype
1219 : return expression for a deduced return call op to allow for simple
1220 : implementation of the conversion operator. */
1221 :
1222 25192 : tree objfn;
1223 25192 : int nargs = list_length (DECL_ARGUMENTS (callop));
1224 25192 : if (thisarg)
1225 : {
1226 25167 : tree instance = cp_build_fold_indirect_ref (thisarg);
1227 25167 : objfn = lookup_template_function (DECL_NAME (callop),
1228 25167 : DECL_TI_ARGS (callop));
1229 25167 : objfn = build_min (COMPONENT_REF, NULL_TREE,
1230 : instance, objfn, NULL_TREE);
1231 25167 : --nargs;
1232 25167 : call = prepare_op_call (objfn, nargs);
1233 : }
1234 : else
1235 : objfn = callop;
1236 :
1237 25192 : if (type_uses_auto (fn_result))
1238 24995 : decltype_call = prepare_op_call (objfn, nargs);
1239 : }
1240 85486 : else if (thisarg)
1241 : {
1242 85251 : direct_argvec = make_tree_vector ();
1243 85251 : direct_argvec->quick_push (thisarg);
1244 : }
1245 :
1246 : /* Copy CALLOP's argument list (as per 'copy_list') as FN_ARGS in order to
1247 : declare the static member function "_FUN" below. For each arg append to
1248 : DIRECT_ARGVEC (for the non-template case) or populate the pre-allocated
1249 : call args (for the template case). If a parameter pack is found, expand
1250 : it, flagging it as PACK_EXPANSION_LOCAL_P for the body call. */
1251 :
1252 110678 : tree fn_args = NULL_TREE;
1253 110678 : {
1254 110678 : int ix = 0;
1255 110678 : tree src = FUNCTION_FIRST_USER_PARM (callop);
1256 110678 : tree tgt = NULL;
1257 :
1258 110678 : if (!thisarg && !decltype_call)
1259 110678 : src = NULL_TREE;
1260 209883 : while (src)
1261 : {
1262 99205 : tree new_node = copy_node (src);
1263 : /* We set DECL_CONTEXT of NEW_NODE to the statfn below.
1264 : Notice this is creating a recursive type! */
1265 :
1266 : /* Clear TREE_ADDRESSABLE on thunk arguments. */
1267 99205 : TREE_ADDRESSABLE (new_node) = 0;
1268 :
1269 99205 : if (!fn_args)
1270 66255 : fn_args = tgt = new_node;
1271 : else
1272 : {
1273 32950 : TREE_CHAIN (tgt) = new_node;
1274 32950 : tgt = new_node;
1275 : }
1276 :
1277 99205 : mark_exp_read (tgt);
1278 :
1279 99205 : if (generic_lambda_p)
1280 : {
1281 45939 : tree a = tgt;
1282 45939 : if (thisarg)
1283 : {
1284 45912 : if (DECL_PACK_P (tgt))
1285 : {
1286 583 : a = make_pack_expansion (a);
1287 583 : PACK_EXPANSION_LOCAL_P (a) = true;
1288 : }
1289 45912 : CALL_EXPR_ARG (call, ix) = a;
1290 : }
1291 :
1292 45939 : if (decltype_call)
1293 : {
1294 : /* Avoid capturing variables in this context. */
1295 45657 : ++cp_unevaluated_operand;
1296 45657 : CALL_EXPR_ARG (decltype_call, ix) = forward_parm (tgt);
1297 45657 : --cp_unevaluated_operand;
1298 : }
1299 :
1300 45939 : ++ix;
1301 : }
1302 : else
1303 53266 : vec_safe_push (direct_argvec, tgt);
1304 :
1305 99205 : src = TREE_CHAIN (src);
1306 : }
1307 : }
1308 :
1309 110678 : if (generic_lambda_p)
1310 : {
1311 25192 : if (decltype_call)
1312 : {
1313 24995 : fn_result = finish_decltype_type
1314 24995 : (decltype_call, /*id_expression_or_member_access_p=*/false,
1315 : tf_warning_or_error);
1316 : }
1317 : }
1318 85486 : else if (thisarg)
1319 : {
1320 : /* Don't warn on deprecated or unavailable lambda declarations, unless
1321 : the lambda is actually called. */
1322 85251 : auto du = make_temp_override (deprecated_state,
1323 85251 : UNAVAILABLE_DEPRECATED_SUPPRESS);
1324 85251 : call = build_call_a (callop, direct_argvec->length (),
1325 : direct_argvec->address ());
1326 85251 : }
1327 :
1328 110678 : if (thisarg)
1329 : {
1330 110418 : CALL_FROM_THUNK_P (call) = 1;
1331 110418 : SET_EXPR_LOCATION (call, UNKNOWN_LOCATION);
1332 : }
1333 :
1334 110678 : tree stattype
1335 110678 : = cp_build_function_type (fn_result,
1336 110678 : FUNCTION_FIRST_USER_PARMTYPE (callop));
1337 110678 : stattype = cp_build_type_attribute_variant (stattype,
1338 110678 : TYPE_ATTRIBUTES (optype));
1339 110678 : if (flag_noexcept_type
1340 110678 : && TYPE_NOTHROW_P (TREE_TYPE (callop)))
1341 82 : stattype = build_exception_variant (stattype, noexcept_true_spec);
1342 :
1343 110678 : if (generic_lambda_p)
1344 25192 : --processing_template_decl;
1345 :
1346 : /* First build up the conversion op. */
1347 :
1348 110678 : tree rettype = build_pointer_type (stattype);
1349 110678 : tree name = make_conv_op_name (rettype);
1350 110678 : tree thistype = cp_build_qualified_type (type, TYPE_QUAL_CONST);
1351 110678 : tree fntype = build_method_type_directly (thistype, rettype, void_list_node);
1352 : /* DR 1722: The conversion function should be noexcept. */
1353 110678 : fntype = build_exception_variant (fntype, noexcept_true_spec);
1354 110678 : tree convfn = build_lang_decl (FUNCTION_DECL, name, fntype);
1355 110678 : SET_DECL_LANGUAGE (convfn, lang_cplusplus);
1356 110678 : tree fn = convfn;
1357 110678 : DECL_SOURCE_LOCATION (fn) = DECL_SOURCE_LOCATION (callop);
1358 110678 : SET_DECL_ALIGN (fn, MINIMUM_METHOD_BOUNDARY);
1359 110678 : grokclassfn (type, fn, NO_SPECIAL);
1360 110678 : set_linkage_according_to_type (type, fn);
1361 110678 : rest_of_decl_compilation (fn, namespace_bindings_p (), at_eof);
1362 110678 : DECL_IN_AGGR_P (fn) = 1;
1363 110678 : DECL_ARTIFICIAL (fn) = 1;
1364 110678 : DECL_NOT_REALLY_EXTERN (fn) = 1;
1365 110678 : DECL_DECLARED_INLINE_P (fn) = 1;
1366 110678 : DECL_DECLARED_CONSTEXPR_P (fn) = DECL_DECLARED_CONSTEXPR_P (callop);
1367 221356 : if (DECL_IMMEDIATE_FUNCTION_P (callop))
1368 3112 : SET_DECL_IMMEDIATE_FUNCTION_P (fn);
1369 110678 : DECL_ARGUMENTS (fn) = build_this_parm (fn, fntype, TYPE_QUAL_CONST);
1370 :
1371 110678 : if (nested_def)
1372 105544 : DECL_INTERFACE_KNOWN (fn) = 1;
1373 :
1374 110678 : if (generic_lambda_p)
1375 25192 : fn = add_inherited_template_parms (fn, DECL_TI_TEMPLATE (callop));
1376 :
1377 110678 : add_method (type, fn, false);
1378 :
1379 110678 : if (thisarg == NULL_TREE)
1380 : {
1381 : /* For static lambda, just return operator(). */
1382 260 : if (nested)
1383 85 : push_function_context ();
1384 : else
1385 : /* Still increment function_depth so that we don't GC in the
1386 : middle of an expression. */
1387 175 : ++function_depth;
1388 :
1389 : /* Generate the body of the conversion op. */
1390 :
1391 260 : start_preparsed_function (convfn, NULL_TREE,
1392 : SF_PRE_PARSED | SF_INCLASS_INLINE);
1393 260 : tree body = begin_function_body ();
1394 260 : tree compound_stmt = begin_compound_stmt (0);
1395 :
1396 : /* decl_needed_p needs to see that it's used. */
1397 260 : TREE_USED (callop) = 1;
1398 260 : finish_return_stmt (decay_conversion (callop, tf_warning_or_error));
1399 :
1400 260 : finish_compound_stmt (compound_stmt);
1401 260 : finish_function_body (body);
1402 :
1403 260 : fn = finish_function (/*inline_p=*/true);
1404 260 : if (!generic_lambda_p)
1405 235 : expand_or_defer_fn (fn);
1406 :
1407 260 : if (nested)
1408 85 : pop_function_context ();
1409 : else
1410 175 : --function_depth;
1411 260 : return;
1412 : }
1413 :
1414 : /* Generic thunk code fails for varargs; we'll complain in mark_used if
1415 : the conversion op is used. */
1416 110418 : if (varargs_function_p (callop))
1417 : {
1418 205 : DECL_DELETED_FN (fn) = 1;
1419 205 : return;
1420 : }
1421 :
1422 : /* Now build up the thunk to be returned. */
1423 :
1424 110213 : tree statfn = build_lang_decl (FUNCTION_DECL, fun_identifier, stattype);
1425 110213 : SET_DECL_LANGUAGE (statfn, lang_cplusplus);
1426 110213 : fn = statfn;
1427 110213 : DECL_SOURCE_LOCATION (fn) = DECL_SOURCE_LOCATION (callop);
1428 110213 : grokclassfn (type, fn, NO_SPECIAL);
1429 110213 : set_linkage_according_to_type (type, fn);
1430 110213 : rest_of_decl_compilation (fn, namespace_bindings_p (), at_eof);
1431 110213 : DECL_IN_AGGR_P (fn) = 1;
1432 110213 : DECL_ARTIFICIAL (fn) = 1;
1433 110213 : DECL_NOT_REALLY_EXTERN (fn) = 1;
1434 110213 : DECL_DECLARED_INLINE_P (fn) = 1;
1435 110213 : DECL_STATIC_FUNCTION_P (fn) = 1;
1436 110213 : DECL_DECLARED_CONSTEXPR_P (fn) = DECL_DECLARED_CONSTEXPR_P (callop);
1437 220426 : if (DECL_IMMEDIATE_FUNCTION_P (callop))
1438 2902 : SET_DECL_IMMEDIATE_FUNCTION_P (fn);
1439 110213 : DECL_ARGUMENTS (fn) = fn_args;
1440 209199 : for (tree arg = fn_args; arg; arg = DECL_CHAIN (arg))
1441 : {
1442 : /* Avoid duplicate -Wshadow warnings. */
1443 98986 : DECL_NAME (arg) = NULL_TREE;
1444 98986 : DECL_CONTEXT (arg) = fn;
1445 : }
1446 110213 : if (nested_def)
1447 105266 : DECL_INTERFACE_KNOWN (fn) = 1;
1448 :
1449 110213 : if (generic_lambda_p)
1450 25155 : fn = add_inherited_template_parms (fn, DECL_TI_TEMPLATE (callop));
1451 :
1452 110213 : if (flag_sanitize & SANITIZE_NULL)
1453 : /* Don't UBsan this function; we're deliberately calling op() with a null
1454 : object argument. */
1455 37 : add_no_sanitize_value (fn, SANITIZE_UNDEFINED);
1456 :
1457 110213 : add_method (type, fn, false);
1458 :
1459 110213 : if (nested)
1460 105325 : push_function_context ();
1461 : else
1462 : /* Still increment function_depth so that we don't GC in the
1463 : middle of an expression. */
1464 4888 : ++function_depth;
1465 :
1466 : /* Generate the body of the thunk. */
1467 :
1468 110213 : start_preparsed_function (statfn, NULL_TREE,
1469 : SF_PRE_PARSED | SF_INCLASS_INLINE);
1470 110213 : tree body = begin_function_body ();
1471 110213 : tree compound_stmt = begin_compound_stmt (0);
1472 110213 : if (!generic_lambda_p)
1473 : {
1474 85058 : set_flags_from_callee (call);
1475 85058 : if (MAYBE_CLASS_TYPE_P (TREE_TYPE (call)))
1476 2272 : call = build_cplus_new (TREE_TYPE (call), call, tf_warning_or_error);
1477 : }
1478 110213 : call = convert_from_reference (call);
1479 110213 : finish_return_stmt (call);
1480 :
1481 110213 : finish_compound_stmt (compound_stmt);
1482 110213 : finish_function_body (body);
1483 :
1484 110213 : fn = finish_function (/*inline_p=*/true);
1485 110213 : if (!generic_lambda_p)
1486 85058 : expand_or_defer_fn (fn);
1487 :
1488 : /* Generate the body of the conversion op. */
1489 :
1490 110213 : start_preparsed_function (convfn, NULL_TREE,
1491 : SF_PRE_PARSED | SF_INCLASS_INLINE);
1492 110213 : body = begin_function_body ();
1493 110213 : compound_stmt = begin_compound_stmt (0);
1494 :
1495 : /* decl_needed_p needs to see that it's used. */
1496 110213 : TREE_USED (statfn) = 1;
1497 110213 : finish_return_stmt (decay_conversion (statfn, tf_warning_or_error));
1498 :
1499 110213 : finish_compound_stmt (compound_stmt);
1500 110213 : finish_function_body (body);
1501 :
1502 110213 : fn = finish_function (/*inline_p=*/true);
1503 110213 : if (!generic_lambda_p)
1504 85058 : expand_or_defer_fn (fn);
1505 :
1506 110213 : if (nested)
1507 105325 : pop_function_context ();
1508 : else
1509 4888 : --function_depth;
1510 : }
1511 :
1512 : /* True if FN is the static function "_FUN" that gets returned from the lambda
1513 : conversion operator. */
1514 :
1515 : bool
1516 1581814 : lambda_static_thunk_p (tree fn)
1517 : {
1518 1581814 : return (fn && TREE_CODE (fn) == FUNCTION_DECL
1519 1581814 : && DECL_ARTIFICIAL (fn)
1520 126753 : && DECL_STATIC_FUNCTION_P (fn)
1521 1829992 : && LAMBDA_TYPE_P (CP_DECL_CONTEXT (fn)));
1522 : }
1523 :
1524 : bool
1525 274479825 : call_from_lambda_thunk_p (tree call)
1526 : {
1527 274479825 : return (CALL_FROM_THUNK_P (call)
1528 274479825 : && lambda_static_thunk_p (current_function_decl));
1529 : }
1530 :
1531 : /* Returns true iff VAL is a lambda-related declaration which should
1532 : be ignored by unqualified lookup. */
1533 :
1534 : bool
1535 3518095978 : is_lambda_ignored_entity (tree val)
1536 : {
1537 : /* Look past normal, non-VLA capture proxies. */
1538 3518095978 : if (is_normal_capture_proxy (val)
1539 3518095978 : && !variably_modified_type_p (TREE_TYPE (val), NULL_TREE))
1540 : return true;
1541 :
1542 : /* Always ignore lambda fields, their names are only for debugging. */
1543 3510928661 : if (TREE_CODE (val) == FIELD_DECL
1544 3510928661 : && CLASSTYPE_LAMBDA_EXPR (DECL_CONTEXT (val)))
1545 : return true;
1546 :
1547 : /* None of the lookups that use qualify_lookup want the op() from the
1548 : lambda; they want the one from the enclosing class. */
1549 3510928634 : if (tree fns = maybe_get_fns (val))
1550 1159570636 : if (LAMBDA_FUNCTION_P (OVL_FIRST (fns)))
1551 : return true;
1552 :
1553 : return false;
1554 : }
1555 :
1556 : /* Lambdas that appear in variable initializer or default argument
1557 : scope get that in their mangling, so we need to record it. Also,
1558 : multiple lambdas in the same scope may need a mangling
1559 : discriminator. In ABI <= 17, there is a single per-scope sequence
1560 : number. In ABI >= 18, there are per-scope per-signature sequence
1561 : numbers. */
1562 : struct GTY(()) lambda_sig_count
1563 : {
1564 : tree fn; // The lambda fn whose sig this is.
1565 : unsigned count;
1566 : };
1567 : struct GTY(()) lambda_discriminator
1568 : {
1569 : tree scope;
1570 : unsigned nesting; // Inside a function, VAR_DECLs get the function
1571 : // as scope. This counts that nesting.
1572 : unsigned count; // The per-scope counter.
1573 : vec<lambda_sig_count, va_gc> *discriminators; // Per-signature counters
1574 : };
1575 : // The current scope.
1576 : static GTY(()) lambda_discriminator lambda_scope;
1577 : // Stack of previous scopes.
1578 : static GTY(()) vec<lambda_discriminator, va_gc> *lambda_scope_stack;
1579 :
1580 : // Push DECL as lambda extra scope, also new discriminator counters.
1581 :
1582 : void
1583 338600937 : start_lambda_scope (tree decl)
1584 : {
1585 338600937 : gcc_checking_assert (decl);
1586 338600937 : if (current_function_decl && VAR_P (decl))
1587 : // If we're inside a function, we ignore variable scope. Don't push.
1588 48307382 : lambda_scope.nesting++;
1589 : else
1590 : {
1591 290293555 : vec_safe_push (lambda_scope_stack, lambda_scope);
1592 290293555 : lambda_scope.scope = decl;
1593 290293555 : lambda_scope.nesting = 0;
1594 290293555 : lambda_scope.count = 0;
1595 290293555 : lambda_scope.discriminators = nullptr;
1596 : }
1597 338600937 : }
1598 :
1599 : // Pop from the current lambda extra scope.
1600 :
1601 : void
1602 338598117 : finish_lambda_scope (void)
1603 : {
1604 338598117 : if (!lambda_scope.nesting--)
1605 : {
1606 290290735 : lambda_scope = lambda_scope_stack->last ();
1607 290290735 : lambda_scope_stack->pop ();
1608 : }
1609 338598117 : }
1610 :
1611 : // Record the current lambda scope into LAMBDA
1612 :
1613 : void
1614 1773412 : record_lambda_scope (tree lambda)
1615 : {
1616 1773412 : tree closure = LAMBDA_EXPR_CLOSURE (lambda);
1617 1773412 : gcc_checking_assert (closure);
1618 :
1619 : /* Before ABI v20, lambdas in static data member initializers did not
1620 : get a dedicated lambda scope. */
1621 1773412 : tree scope = lambda_scope.scope;
1622 1773412 : if (is_static_data_member_initialized_in_class (scope))
1623 : {
1624 148246 : if (!abi_version_at_least (20))
1625 148246 : scope = NULL_TREE;
1626 443495 : if (warn_abi && abi_version_crosses (20) && !processing_template_decl)
1627 : {
1628 18 : if (abi_version_at_least (20))
1629 18 : warning_at (location_of (closure), OPT_Wabi,
1630 : "the mangled name of %qT changed in "
1631 : "%<-fabi-version=20%> (GCC 15.1)", closure);
1632 : else
1633 0 : warning_at (location_of (closure), OPT_Wabi,
1634 : "the mangled name of %qT changes in "
1635 : "%<-fabi-version=20%> (GCC 15.1)", closure);
1636 : }
1637 : }
1638 :
1639 : /* An otherwise unattached class-scope lambda in a member template
1640 : should not have a mangling scope, as the mangling scope will not
1641 : correctly inherit on instantiation. */
1642 1773412 : tree ctx = TYPE_CONTEXT (closure);
1643 1773412 : if (scope
1644 1773412 : && ctx
1645 1772834 : && CLASS_TYPE_P (ctx)
1646 149647 : && ctx == TREE_TYPE (scope)
1647 1774418 : && current_template_depth > template_class_depth (ctx))
1648 : scope = NULL_TREE;
1649 :
1650 1773412 : LAMBDA_EXPR_EXTRA_SCOPE (lambda) = scope;
1651 1773412 : if (scope)
1652 1772797 : maybe_key_decl (scope, TYPE_NAME (closure));
1653 1773412 : }
1654 :
1655 : // Compare lambda template heads TMPL_A and TMPL_B, used for both
1656 : // templated lambdas, and template template parameters of said lambda.
1657 :
1658 : static bool
1659 28154 : compare_lambda_template_head (tree tmpl_a, tree tmpl_b)
1660 : {
1661 : // We only need one level of template parms
1662 28154 : tree inner_a = INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (tmpl_a));
1663 28154 : tree inner_b = INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (tmpl_b));
1664 :
1665 : // We only compare explicit template parms, ignoring trailing
1666 : // synthetic ones.
1667 28154 : int len_a = TREE_VEC_LENGTH (inner_a);
1668 28154 : int len_b = TREE_VEC_LENGTH (inner_b);
1669 :
1670 28870 : for (int ix = 0, len = MAX (len_a, len_b); ix != len; ix++)
1671 : {
1672 28201 : tree parm_a = NULL_TREE;
1673 28201 : if (ix < len_a)
1674 : {
1675 28189 : parm_a = TREE_VEC_ELT (inner_a, ix);
1676 28189 : if (parm_a == error_mark_node)
1677 : return false;
1678 28189 : parm_a = TREE_VALUE (parm_a);
1679 28189 : if (parm_a == error_mark_node)
1680 : return false;
1681 28189 : if (DECL_VIRTUAL_P (parm_a))
1682 14564 : parm_a = NULL_TREE;
1683 : }
1684 :
1685 28201 : tree parm_b = NULL_TREE;
1686 28201 : if (ix < len_b)
1687 : {
1688 28181 : parm_b = TREE_VEC_ELT (inner_b, ix);
1689 28181 : if (parm_b == error_mark_node)
1690 : return false;
1691 28181 : parm_b = TREE_VALUE (parm_b);
1692 28181 : if (parm_b == error_mark_node)
1693 : return false;
1694 28175 : if (DECL_VIRTUAL_P (parm_b))
1695 15187 : parm_b = NULL_TREE;
1696 : }
1697 :
1698 28195 : if (!parm_a && !parm_b)
1699 : // we're done
1700 : break;
1701 :
1702 13704 : if (!(parm_a && parm_b))
1703 : return false;
1704 :
1705 12940 : if (TREE_CODE (parm_a) != TREE_CODE (parm_b))
1706 : return false;
1707 :
1708 12530 : if (TREE_CODE (parm_a) == PARM_DECL)
1709 : {
1710 11832 : if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm_a))
1711 11832 : != TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm_b)))
1712 : return false;
1713 :
1714 27 : if (!same_type_p (TREE_TYPE (parm_a), TREE_TYPE (parm_b)))
1715 : return false;
1716 : }
1717 : else
1718 : {
1719 698 : if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm_a))
1720 698 : != TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm_b)))
1721 : return false;
1722 :
1723 698 : if (TREE_CODE (parm_a) != TEMPLATE_DECL)
1724 698 : gcc_checking_assert (TREE_CODE (parm_a) == TYPE_DECL);
1725 0 : else if (!compare_lambda_template_head (parm_a, parm_b))
1726 : return false;
1727 : }
1728 : }
1729 :
1730 : return true;
1731 : }
1732 :
1733 : // Compare lambda signatures FN_A and FN_B, they may be TEMPLATE_DECLs too.
1734 :
1735 : static bool
1736 369054 : compare_lambda_sig (tree fn_a, tree fn_b)
1737 : {
1738 369054 : if (TREE_CODE (fn_a) == TEMPLATE_DECL
1739 56979 : && TREE_CODE (fn_b) == TEMPLATE_DECL)
1740 : {
1741 28154 : if (!compare_lambda_template_head (fn_a, fn_b))
1742 : return false;
1743 15160 : fn_a = DECL_TEMPLATE_RESULT (fn_a);
1744 15160 : fn_b = DECL_TEMPLATE_RESULT (fn_b);
1745 : }
1746 340900 : else if (TREE_CODE (fn_a) == TEMPLATE_DECL
1747 312075 : || TREE_CODE (fn_b) == TEMPLATE_DECL)
1748 : return false;
1749 :
1750 326912 : if (fn_a == error_mark_node
1751 326910 : || fn_b == error_mark_node)
1752 : return false;
1753 :
1754 653818 : for (tree args_a = FUNCTION_FIRST_USER_PARMTYPE (fn_a),
1755 326909 : args_b = FUNCTION_FIRST_USER_PARMTYPE (fn_b);
1756 605452 : args_a || args_b;
1757 278543 : args_a = TREE_CHAIN (args_a), args_b = TREE_CHAIN (args_b))
1758 : {
1759 447373 : if (!args_a || !args_b)
1760 : return false;
1761 : // This check also deals with differing variadicness
1762 447369 : if (!same_type_p (TREE_VALUE (args_a), TREE_VALUE (args_b)))
1763 : return false;
1764 : }
1765 :
1766 : return true;
1767 : }
1768 :
1769 : // Record the per-scope discriminator of LAMBDA. If the extra scope
1770 : // is empty, we must use the empty scope counter, which might not be
1771 : // the live one.
1772 :
1773 : void
1774 1773912 : record_lambda_scope_discriminator (tree lambda)
1775 : {
1776 3547112 : auto *slot = (vec_safe_is_empty (lambda_scope_stack)
1777 1773200 : || LAMBDA_EXPR_EXTRA_SCOPE (lambda)
1778 403 : ? &lambda_scope : lambda_scope_stack->begin ());
1779 1773912 : LAMBDA_EXPR_SCOPE_ONLY_DISCRIMINATOR (lambda) = slot->count++;
1780 1773912 : }
1781 :
1782 : // Record the per-scope per-signature discriminator of LAMBDA. If the
1783 : // extra scope is empty, we must use the empty scope counter, which
1784 : // might not be the live one.
1785 :
1786 : void
1787 1773900 : record_lambda_scope_sig_discriminator (tree lambda, tree fn)
1788 : {
1789 3547088 : auto *slot = (vec_safe_is_empty (lambda_scope_stack)
1790 1773188 : || LAMBDA_EXPR_EXTRA_SCOPE (lambda)
1791 400 : ? &lambda_scope : lambda_scope_stack->begin ());
1792 1773900 : gcc_checking_assert (LAMBDA_EXPR_EXTRA_SCOPE (lambda) == slot->scope);
1793 :
1794 : // A linear search, we're not expecting this to be a big list, and
1795 : // this avoids needing a signature hash function.
1796 1773900 : lambda_sig_count *sig;
1797 1773900 : if (unsigned ix = vec_safe_length (slot->discriminators))
1798 559644 : for (sig = slot->discriminators->begin (); ix--; sig++)
1799 369054 : if (compare_lambda_sig (fn, sig->fn))
1800 158079 : goto found;
1801 1615821 : {
1802 1615821 : lambda_sig_count init = {fn, 0};
1803 1615821 : sig = vec_safe_push (slot->discriminators, init);
1804 : }
1805 1773900 : found:
1806 1773900 : LAMBDA_EXPR_SCOPE_SIG_DISCRIMINATOR (lambda) = sig->count++;
1807 1773900 : }
1808 :
1809 : /* Push the proxies for any explicit captures in LAMBDA_EXPR.
1810 : If EARLY_P, we do not have the real operator() yet. */
1811 :
1812 : void
1813 3547778 : push_capture_proxies (tree lambda_expr, bool early_p)
1814 : {
1815 7349784 : for (tree cap = LAMBDA_EXPR_CAPTURE_LIST (lambda_expr); cap;
1816 3802006 : cap = TREE_CHAIN (cap))
1817 3802006 : build_capture_proxy (TREE_PURPOSE (cap), TREE_VALUE (cap), early_p);
1818 3547778 : }
1819 :
1820 : tree
1821 1773866 : start_lambda_function (tree fco, tree lambda_expr)
1822 : {
1823 : /* Let the front end know that we are going to be defining this
1824 : function. */
1825 1773866 : start_preparsed_function (fco,
1826 : NULL_TREE,
1827 : SF_PRE_PARSED | SF_INCLASS_INLINE);
1828 :
1829 1773866 : tree body = begin_function_body ();
1830 :
1831 : /* Push the proxies for any explicit captures. */
1832 1773866 : push_capture_proxies (lambda_expr);
1833 :
1834 1773866 : return body;
1835 : }
1836 :
1837 : /* Subroutine of prune_lambda_captures: CAP is a node in
1838 : LAMBDA_EXPR_CAPTURE_LIST. Return the variable it captures for which we
1839 : might optimize away the capture, or NULL_TREE if there is no such
1840 : variable. */
1841 :
1842 : static tree
1843 1236 : var_to_maybe_prune (tree cap)
1844 : {
1845 1236 : if (LAMBDA_CAPTURE_EXPLICIT_P (cap))
1846 : /* Don't prune explicit captures. */
1847 : return NULL_TREE;
1848 :
1849 1227 : tree mem = TREE_PURPOSE (cap);
1850 2454 : if (!DECL_P (mem) || !DECL_NORMAL_CAPTURE_P (mem))
1851 : /* Packs and init-captures aren't captures of constant vars. */
1852 : return NULL_TREE;
1853 :
1854 1227 : tree init = TREE_VALUE (cap);
1855 1227 : if (is_normal_capture_proxy (init))
1856 0 : init = DECL_CAPTURED_VARIABLE (init);
1857 1227 : if (decl_constant_var_p (init))
1858 : return init;
1859 :
1860 : return NULL_TREE;
1861 : }
1862 :
1863 : /* walk_tree helper for prune_lambda_captures: Remember which capture proxies
1864 : for constant variables are actually used in the lambda body.
1865 :
1866 : There will always be a DECL_EXPR for the capture proxy; remember it when we
1867 : see it, but replace it with any other use. */
1868 :
1869 : static tree
1870 17854 : mark_const_cap_r (tree *t, int *walk_subtrees, void *data)
1871 : {
1872 17854 : hash_map<tree,tree*> &const_vars = *(hash_map<tree,tree*>*)data;
1873 :
1874 17854 : tree var = NULL_TREE;
1875 17854 : if (TREE_CODE (*t) == DECL_EXPR)
1876 : {
1877 1842 : tree decl = DECL_EXPR_DECL (*t);
1878 1842 : if (is_constant_capture_proxy (decl))
1879 : {
1880 443 : var = DECL_CAPTURED_VARIABLE (decl);
1881 443 : *walk_subtrees = 0;
1882 : }
1883 : }
1884 16012 : else if (!location_wrapper_p (*t) /* is_capture_proxy dislikes them. */
1885 16012 : && is_constant_capture_proxy (*t))
1886 166 : var = DECL_CAPTURED_VARIABLE (*t);
1887 :
1888 17854 : if (var)
1889 : {
1890 609 : tree *&slot = const_vars.get_or_insert (var);
1891 609 : if (!slot || VAR_P (*t))
1892 609 : slot = t;
1893 : }
1894 :
1895 17854 : return NULL_TREE;
1896 : }
1897 :
1898 : /* We're at the end of processing a lambda; go back and remove any captures of
1899 : constant variables for which we've folded away all uses. */
1900 :
1901 : static void
1902 1773866 : prune_lambda_captures (tree body)
1903 : {
1904 1773866 : tree lam = current_lambda_expr ();
1905 1773866 : if (!LAMBDA_EXPR_CAPTURE_OPTIMIZED (lam))
1906 : /* No uses were optimized away. */
1907 1773557 : return;
1908 391 : if (LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (lam) == CPLD_NONE)
1909 : /* No default captures, and we don't prune explicit captures. */
1910 : return;
1911 : /* Don't bother pruning in a template, we'll prune at instantiation time. */
1912 361 : if (dependent_type_p (TREE_TYPE (lam)))
1913 : return;
1914 :
1915 309 : hash_map<tree,tree*> const_vars;
1916 :
1917 309 : cp_walk_tree_without_duplicates (&body, mark_const_cap_r, &const_vars);
1918 :
1919 309 : tree bind_expr = expr_single (DECL_SAVED_TREE (lambda_function (lam)));
1920 630 : bool noexcept_p = (bind_expr
1921 309 : && TREE_CODE (bind_expr) == MUST_NOT_THROW_EXPR);
1922 12 : if (noexcept_p)
1923 12 : bind_expr = expr_single (TREE_OPERAND (bind_expr, 0));
1924 :
1925 309 : tree *fieldp = &TYPE_FIELDS (LAMBDA_EXPR_CLOSURE (lam));
1926 1545 : for (tree *capp = &LAMBDA_EXPR_CAPTURE_LIST (lam); *capp; )
1927 : {
1928 1236 : tree cap = *capp;
1929 1236 : if (tree var = var_to_maybe_prune (cap))
1930 : {
1931 437 : tree **use = const_vars.get (var);
1932 437 : if (TREE_CODE (**use) == DECL_EXPR)
1933 : {
1934 : /* All uses of this capture were folded away, leaving only the
1935 : proxy declaration. */
1936 :
1937 271 : if (noexcept_p)
1938 : {
1939 : /* We didn't handle noexcept lambda captures correctly before
1940 : the fix for PR c++/119764. */
1941 33 : if (abi_version_crosses (21))
1942 3 : warning_at (location_of (lam), OPT_Wabi, "%qD is no longer"
1943 : " captured in noexcept lambda in ABI v21 "
1944 : "(GCC 16)", var);
1945 12 : if (!abi_version_at_least (21))
1946 0 : goto next;
1947 : }
1948 :
1949 : /* Splice the capture out of LAMBDA_EXPR_CAPTURE_LIST. */
1950 271 : *capp = TREE_CHAIN (cap);
1951 :
1952 : /* And out of TYPE_FIELDS. */
1953 271 : tree field = TREE_PURPOSE (cap);
1954 807 : while (*fieldp != field)
1955 536 : fieldp = &DECL_CHAIN (*fieldp);
1956 271 : *fieldp = DECL_CHAIN (*fieldp);
1957 :
1958 : /* And out of the bindings for the function. */
1959 271 : tree *blockp = &BLOCK_VARS (current_binding_level->blocks);
1960 657 : while (*blockp != DECL_EXPR_DECL (**use))
1961 386 : blockp = &DECL_CHAIN (*blockp);
1962 271 : *blockp = DECL_CHAIN (*blockp);
1963 :
1964 : /* And maybe out of the vars declared in the containing
1965 : BIND_EXPR, if it's listed there. */
1966 271 : tree *bindp = &BIND_EXPR_VARS (bind_expr);
1967 602 : while (*bindp && *bindp != DECL_EXPR_DECL (**use))
1968 60 : bindp = &DECL_CHAIN (*bindp);
1969 271 : if (*bindp)
1970 126 : *bindp = DECL_CHAIN (*bindp);
1971 :
1972 : /* And remove the capture proxy declaration. */
1973 271 : **use = void_node;
1974 271 : continue;
1975 271 : }
1976 : }
1977 :
1978 965 : next:
1979 965 : capp = &TREE_CHAIN (cap);
1980 : }
1981 309 : }
1982 :
1983 : // Record the per-scope per-signature discriminator of LAMBDA. If the
1984 : // extra scope is empty, we must use the empty scope counter, which
1985 : // might not be the live one.
1986 :
1987 : void
1988 1773866 : finish_lambda_function (tree body)
1989 : {
1990 1773866 : finish_function_body (body);
1991 :
1992 1773866 : prune_lambda_captures (cur_stmt_list);
1993 :
1994 : /* Finish the function and generate code for it if necessary. */
1995 1773866 : tree fn = finish_function (/*inline_p=*/true);
1996 :
1997 : /* Only expand if the call op is not a template. */
1998 1773866 : if (!DECL_TEMPLATE_INFO (fn))
1999 599708 : expand_or_defer_fn (fn);
2000 1773866 : }
2001 :
2002 : #include "gt-cp-lambda.h"
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