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1 : : /* coroutine-specific state, expansions and tests.
2 : :
3 : : Copyright (C) 2018-2024 Free Software Foundation, Inc.
4 : :
5 : : Contributed by Iain Sandoe <iain@sandoe.co.uk> under contract to Facebook.
6 : :
7 : : This file is part of GCC.
8 : :
9 : : GCC is free software; you can redistribute it and/or modify it under
10 : : the terms of the GNU General Public License as published by the Free
11 : : Software Foundation; either version 3, or (at your option) any later
12 : : version.
13 : :
14 : : GCC is distributed in the hope that it will be useful, but WITHOUT ANY
15 : : WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 : : FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 : : for more details.
18 : :
19 : : You should have received a copy of the GNU General Public License
20 : : along with GCC; see the file COPYING3. If not see
21 : : <http://www.gnu.org/licenses/>. */
22 : :
23 : : #include "config.h"
24 : : #include "system.h"
25 : : #include "coretypes.h"
26 : : #include "target.h"
27 : : #include "cp-tree.h"
28 : : #include "stringpool.h"
29 : : #include "stmt.h"
30 : : #include "stor-layout.h"
31 : : #include "tree-iterator.h"
32 : : #include "tree.h"
33 : : #include "gcc-rich-location.h"
34 : : #include "hash-map.h"
35 : : #include "coroutines.h"
36 : :
37 : : /* ================= Debug. ================= */
38 : :
39 : : #include "langhooks.h"
40 : : #include "cxx-pretty-print.h"
41 : :
42 : : /* Walk through the fields of the type TYP and print them to the pretty printer
43 : : PP. */
44 : :
45 : : static void
46 : 0 : dump_record_fields (cxx_pretty_printer *pp, tree typ)
47 : : {
48 : 0 : pp->type_id (typ);
49 : 0 : pp_newline_and_indent (pp, 2);
50 : 0 : pp_left_brace (pp);
51 : 0 : pp_indentation (pp) += 2;
52 : :
53 : : /* We'll be on a new line, we don't need padding. */
54 : 0 : pp->set_padding (pp_none);
55 : :
56 : 0 : for (tree tmp = TYPE_FIELDS (typ); tmp; tmp = DECL_CHAIN (tmp))
57 : : {
58 : 0 : pp_newline_and_indent (pp, 0);
59 : 0 : pp->declaration (tmp);
60 : : }
61 : :
62 : 0 : pp_newline_and_indent (pp, -2);
63 : 0 : pp_right_brace (pp);
64 : 0 : pp_newline_and_indent (pp, -2);
65 : 0 : }
66 : :
67 : : /* The lang-coro stream. */
68 : : static FILE *dmp_str = NULL;
69 : :
70 : : /* ID of the lang-coro dump. */
71 : : int coro_dump_id;
72 : :
73 : : /* Flags passed to the lang-coro dump. */
74 : : static dump_flags_t coro_dump_flags;
75 : :
76 : : /* Pretty print the function FNDECL, which ought to be a coroutine before
77 : : co_await expansion, into the lang-coro dump, if it is enabled. */
78 : :
79 : : static void
80 : 1369 : coro_maybe_dump_initial_function (tree fndecl)
81 : : {
82 : 1369 : if (!dmp_str)
83 : 1369 : return;
84 : :
85 : 0 : bool lambda_p = LAMBDA_TYPE_P (DECL_CONTEXT (fndecl));
86 : 0 : fprintf (dmp_str, "%s %s original:\n",
87 : : (lambda_p ? "Lambda" : "Function"),
88 : 0 : lang_hooks.decl_printable_name (fndecl, 2));
89 : :
90 : 0 : cxx_pretty_printer pp;
91 : 0 : pp.set_output_stream (dmp_str);
92 : 0 : pp.flags = coro_dump_flags;
93 : 0 : pp.declaration (fndecl);
94 : 0 : pp_newline_and_flush (&pp);
95 : 0 : }
96 : :
97 : : /* Pretty print the RAMP function to the lang-coro dump, if it is enabled. */
98 : :
99 : : static void
100 : 1348 : coro_maybe_dump_ramp (tree ramp)
101 : : {
102 : 1348 : if (!dmp_str)
103 : 1348 : return;
104 : :
105 : 0 : cxx_pretty_printer pp;
106 : 0 : pp.set_output_stream (dmp_str);
107 : 0 : pp.flags = coro_dump_flags;
108 : :
109 : 0 : pp_string (&pp, "Ramp function:");
110 : 0 : pp_newline_and_indent (&pp, 0);
111 : 0 : pp.declaration (ramp);
112 : 0 : pp_newline_and_flush (&pp);
113 : 0 : }
114 : :
115 : : /* For a given ACTOR and DESTROY, if lang-coro dumping is enabled, pretty-print
116 : : their contents to the lang-coro dump. */
117 : :
118 : : static void
119 : 1338 : coro_maybe_dump_transformed_functions (tree actor, tree destroy)
120 : : {
121 : 1338 : if (!dmp_str)
122 : 1338 : return;
123 : :
124 : 0 : cxx_pretty_printer pp;
125 : 0 : pp.set_output_stream (dmp_str);
126 : 0 : pp.flags = coro_dump_flags;
127 : :
128 : 0 : if (!actor || actor == error_mark_node)
129 : : {
130 : 0 : pp_string (&pp, "Transform failed");
131 : 0 : pp_newline_and_flush (&pp);
132 : 0 : return;
133 : : }
134 : :
135 : 0 : tree frame = TREE_TYPE (TREE_TYPE (DECL_ARGUMENTS (actor)));
136 : 0 : pp_string (&pp, "Frame type:");
137 : 0 : pp_newline (&pp);
138 : 0 : dump_record_fields (&pp, frame);
139 : 0 : pp_newline_and_flush (&pp);
140 : :
141 : 0 : pp_string (&pp, "Actor/resumer:");
142 : 0 : pp_newline (&pp);
143 : 0 : pp.declaration (actor);
144 : 0 : pp_newline_and_flush (&pp);
145 : :
146 : 0 : pp_string (&pp, "Destroyer:");
147 : 0 : pp_newline (&pp);
148 : 0 : pp.declaration (destroy);
149 : 0 : pp_newline_and_flush (&pp);
150 : 0 : }
151 : :
152 : : /* ================= END Debug. ================= */
153 : :
154 : : static bool coro_promise_type_found_p (tree, location_t);
155 : :
156 : : /* GCC C++ coroutines implementation.
157 : :
158 : : The user authors a function that becomes a coroutine (lazily) by
159 : : making use of any of the co_await, co_yield or co_return keywords.
160 : :
161 : : Unlike a regular function, where the activation record is placed on the
162 : : stack, and is destroyed on function exit, a coroutine has some state that
163 : : persists between calls - the coroutine frame (analogous to a stack frame).
164 : :
165 : : We transform the user's function into three pieces:
166 : : 1. A so-called ramp function, that establishes the coroutine frame and
167 : : begins execution of the coroutine.
168 : : 2. An actor function that contains the state machine corresponding to the
169 : : user's suspend/resume structure.
170 : : 3. A stub function that calls the actor function in 'destroy' mode.
171 : :
172 : : The actor function is executed:
173 : : * from "resume point 0" by the ramp.
174 : : * from resume point N ( > 0 ) for handle.resume() calls.
175 : : * from the destroy stub for destroy point N for handle.destroy() calls.
176 : :
177 : : The functions in this file carry out the necessary analysis of, and
178 : : transforms to, the AST to perform this.
179 : :
180 : : The C++ coroutine design makes use of some helper functions that are
181 : : authored in a so-called "promise" class provided by the user.
182 : :
183 : : At parse time (or post substitution) the type of the coroutine promise
184 : : will be determined. At that point, we can look up the required promise
185 : : class methods and issue diagnostics if they are missing or incorrect. To
186 : : avoid repeating these actions at code-gen time, we make use of temporary
187 : : 'proxy' variables for the coroutine handle and the promise - which will
188 : : eventually be instantiated in the coroutine frame.
189 : :
190 : : Each of the keywords will expand to a code sequence (although co_yield is
191 : : just syntactic sugar for a co_await).
192 : :
193 : : We defer the analysis and transformation until template expansion is
194 : : complete so that we have complete types at that time. */
195 : :
196 : :
197 : : /* The state that we collect during parsing (and template expansion) for
198 : : a coroutine. */
199 : :
200 : 2688 : struct GTY((for_user)) coroutine_info
201 : : {
202 : : tree function_decl; /* The original function decl. */
203 : : tree actor_decl; /* The synthesized actor function. */
204 : : tree destroy_decl; /* The synthesized destroy function. */
205 : : tree promise_type; /* The cached promise type for this function. */
206 : : tree traits_type; /* The cached traits type for this function. */
207 : : tree handle_type; /* The cached coroutine handle for this function. */
208 : : tree self_h_proxy; /* A handle instance that is used as the proxy for the
209 : : one that will eventually be allocated in the coroutine
210 : : frame. */
211 : : tree promise_proxy; /* Likewise, a proxy promise instance. */
212 : : tree from_address; /* handle_type from_address function. */
213 : : tree return_void; /* The expression for p.return_void() if it exists. */
214 : : location_t first_coro_keyword; /* The location of the keyword that made this
215 : : function into a coroutine. */
216 : :
217 : : /* Temporary variable number assigned by get_awaitable_var. */
218 : : int awaitable_number = 0;
219 : :
220 : : /* Flags to avoid repeated errors for per-function issues. */
221 : : bool coro_ret_type_error_emitted;
222 : : bool coro_promise_error_emitted;
223 : : bool coro_co_return_error_emitted;
224 : : };
225 : :
226 : : struct coroutine_info_hasher : ggc_ptr_hash<coroutine_info>
227 : : {
228 : : typedef tree compare_type; /* We only compare the function decl. */
229 : : static inline hashval_t hash (coroutine_info *);
230 : : static inline hashval_t hash (const compare_type &);
231 : : static inline bool equal (coroutine_info *, coroutine_info *);
232 : : static inline bool equal (coroutine_info *, const compare_type &);
233 : : };
234 : :
235 : : /* This table holds all the collected coroutine state for coroutines in
236 : : the current translation unit. */
237 : :
238 : : static GTY (()) hash_table<coroutine_info_hasher> *coroutine_info_table;
239 : :
240 : : /* We will initialize state lazily. */
241 : : static bool coro_initialized = false;
242 : :
243 : : /* Return a hash value for the entry pointed to by INFO.
244 : : The compare type is a tree, but the only trees we are going use are
245 : : function decls. We use the DECL_UID as the hash value since that is
246 : : stable across PCH. */
247 : :
248 : : hashval_t
249 : 59081 : coroutine_info_hasher::hash (coroutine_info *info)
250 : : {
251 : 59081 : return DECL_UID (info->function_decl);
252 : : }
253 : :
254 : : /* Return a hash value for the compare value COMP. */
255 : :
256 : : hashval_t
257 : 54717 : coroutine_info_hasher::hash (const compare_type& comp)
258 : : {
259 : 54717 : return DECL_UID (comp);
260 : : }
261 : :
262 : : /* Return true if the entries pointed to by LHS and RHS are for the
263 : : same coroutine. */
264 : :
265 : : bool
266 : : coroutine_info_hasher::equal (coroutine_info *lhs, coroutine_info *rhs)
267 : : {
268 : : return lhs->function_decl == rhs->function_decl;
269 : : }
270 : :
271 : : bool
272 : 69724 : coroutine_info_hasher::equal (coroutine_info *lhs, const compare_type& rhs)
273 : : {
274 : 69724 : return lhs->function_decl == rhs;
275 : : }
276 : :
277 : : /* Get the existing coroutine_info for FN_DECL, or insert a new one if the
278 : : entry does not yet exist. */
279 : :
280 : : coroutine_info *
281 : 9095 : get_or_insert_coroutine_info (tree fn_decl)
282 : : {
283 : 9095 : gcc_checking_assert (coroutine_info_table != NULL);
284 : :
285 : 9095 : coroutine_info **slot = coroutine_info_table->find_slot_with_hash
286 : 9095 : (fn_decl, coroutine_info_hasher::hash (fn_decl), INSERT);
287 : :
288 : 9095 : if (*slot == NULL)
289 : : {
290 : 2688 : *slot = new (ggc_cleared_alloc<coroutine_info> ()) coroutine_info ();
291 : 2688 : (*slot)->function_decl = fn_decl;
292 : : }
293 : :
294 : 9095 : return *slot;
295 : : }
296 : :
297 : : /* Get the existing coroutine_info for FN_DECL, fail if it doesn't exist. */
298 : :
299 : : coroutine_info *
300 : 45622 : get_coroutine_info (tree fn_decl)
301 : : {
302 : 45622 : if (coroutine_info_table == NULL)
303 : : return NULL;
304 : :
305 : 45622 : coroutine_info **slot = coroutine_info_table->find_slot_with_hash
306 : 45622 : (fn_decl, coroutine_info_hasher::hash (fn_decl), NO_INSERT);
307 : 45622 : if (slot)
308 : 45622 : return *slot;
309 : : return NULL;
310 : : }
311 : :
312 : : /* We will lazily create all the identifiers that are used by coroutines
313 : : on the first attempt to lookup the traits. */
314 : :
315 : : /* Identifiers that are used by all coroutines. */
316 : :
317 : : static GTY(()) tree coro_traits_identifier;
318 : : static GTY(()) tree coro_handle_identifier;
319 : : static GTY(()) tree coro_promise_type_identifier;
320 : :
321 : : /* Required promise method name identifiers. */
322 : :
323 : : static GTY(()) tree coro_await_transform_identifier;
324 : : static GTY(()) tree coro_initial_suspend_identifier;
325 : : static GTY(()) tree coro_final_suspend_identifier;
326 : : static GTY(()) tree coro_return_void_identifier;
327 : : static GTY(()) tree coro_return_value_identifier;
328 : : static GTY(()) tree coro_yield_value_identifier;
329 : : static GTY(()) tree coro_address_identifier;
330 : : static GTY(()) tree coro_from_address_identifier;
331 : : static GTY(()) tree coro_get_return_object_identifier;
332 : : static GTY(()) tree coro_gro_on_allocation_fail_identifier;
333 : : static GTY(()) tree coro_unhandled_exception_identifier;
334 : :
335 : : /* Awaitable methods. */
336 : :
337 : : static GTY(()) tree coro_await_ready_identifier;
338 : : static GTY(()) tree coro_await_suspend_identifier;
339 : : static GTY(()) tree coro_await_resume_identifier;
340 : :
341 : : /* Accessors for the coroutine frame state used by the implementation. */
342 : :
343 : : static GTY(()) tree coro_resume_fn_id;
344 : : static GTY(()) tree coro_destroy_fn_id;
345 : : static GTY(()) tree coro_promise_id;
346 : : static GTY(()) tree coro_frame_needs_free_id;
347 : : static GTY(()) tree coro_resume_index_id;
348 : : static GTY(()) tree coro_self_handle_id;
349 : : static GTY(()) tree coro_actor_continue_id;
350 : : static GTY(()) tree coro_frame_i_a_r_c_id;
351 : :
352 : : /* Create the identifiers used by the coroutines library interfaces and
353 : : the implementation frame state. */
354 : :
355 : : static void
356 : 2341 : coro_init_identifiers ()
357 : : {
358 : 2341 : coro_traits_identifier = get_identifier ("coroutine_traits");
359 : 2341 : coro_handle_identifier = get_identifier ("coroutine_handle");
360 : 2341 : coro_promise_type_identifier = get_identifier ("promise_type");
361 : :
362 : 2341 : coro_await_transform_identifier = get_identifier ("await_transform");
363 : 2341 : coro_initial_suspend_identifier = get_identifier ("initial_suspend");
364 : 2341 : coro_final_suspend_identifier = get_identifier ("final_suspend");
365 : 2341 : coro_return_void_identifier = get_identifier ("return_void");
366 : 2341 : coro_return_value_identifier = get_identifier ("return_value");
367 : 2341 : coro_yield_value_identifier = get_identifier ("yield_value");
368 : 2341 : coro_address_identifier = get_identifier ("address");
369 : 2341 : coro_from_address_identifier = get_identifier ("from_address");
370 : 2341 : coro_get_return_object_identifier = get_identifier ("get_return_object");
371 : 4682 : coro_gro_on_allocation_fail_identifier =
372 : 2341 : get_identifier ("get_return_object_on_allocation_failure");
373 : 2341 : coro_unhandled_exception_identifier = get_identifier ("unhandled_exception");
374 : :
375 : 2341 : coro_await_ready_identifier = get_identifier ("await_ready");
376 : 2341 : coro_await_suspend_identifier = get_identifier ("await_suspend");
377 : 2341 : coro_await_resume_identifier = get_identifier ("await_resume");
378 : :
379 : : /* Coroutine state frame field accessors. */
380 : 2341 : coro_resume_fn_id = get_identifier ("_Coro_resume_fn");
381 : 2341 : coro_destroy_fn_id = get_identifier ("_Coro_destroy_fn");
382 : 2341 : coro_promise_id = get_identifier ("_Coro_promise");
383 : 2341 : coro_frame_needs_free_id = get_identifier ("_Coro_frame_needs_free");
384 : 2341 : coro_frame_i_a_r_c_id = get_identifier ("_Coro_initial_await_resume_called");
385 : 2341 : coro_resume_index_id = get_identifier ("_Coro_resume_index");
386 : 2341 : coro_self_handle_id = get_identifier ("_Coro_self_handle");
387 : 2341 : coro_actor_continue_id = get_identifier ("_Coro_actor_continue");
388 : 2341 : }
389 : :
390 : : /* Trees we only need to set up once. */
391 : :
392 : : static GTY(()) tree coro_traits_templ;
393 : : static GTY(()) tree coro_handle_templ;
394 : : static GTY(()) tree void_coro_handle_type;
395 : : static GTY(()) tree void_coro_handle_address;
396 : :
397 : : /* ================= Parse, Semantics and Type checking ================= */
398 : :
399 : : /* This initial set of routines are helper for the parsing and template
400 : : expansion phases.
401 : :
402 : : At the completion of this, we will have completed trees for each of the
403 : : keywords, but making use of proxy variables for the self-handle and the
404 : : promise class instance. */
405 : :
406 : : /* [coroutine.traits]
407 : : Lookup the coroutine_traits template decl. */
408 : :
409 : : static tree
410 : 2341 : find_coro_traits_template_decl (location_t kw)
411 : : {
412 : : /* If we are missing fundamental information, such as the traits, (or the
413 : : declaration found is not a type template), then don't emit an error for
414 : : every keyword in a TU, just do it once. */
415 : 2341 : static bool traits_error_emitted = false;
416 : :
417 : 4682 : tree traits_decl = lookup_qualified_name (std_node, coro_traits_identifier,
418 : : LOOK_want::NORMAL,
419 : 2341 : /*complain=*/!traits_error_emitted);
420 : 2341 : if (traits_decl == error_mark_node
421 : 2341 : || !DECL_TYPE_TEMPLATE_P (traits_decl))
422 : : {
423 : 10 : if (!traits_error_emitted)
424 : : {
425 : 4 : auto_diagnostic_group d;
426 : 4 : gcc_rich_location richloc (kw);
427 : 4 : error_at (&richloc, "coroutines require a traits template; cannot"
428 : : " find %<%E::%E%>", std_node, coro_traits_identifier);
429 : 4 : inform (&richloc, "perhaps %<#include <coroutine>%> is missing");
430 : 4 : traits_error_emitted = true;
431 : 4 : }
432 : 10 : return NULL_TREE;
433 : : }
434 : : else
435 : : return traits_decl;
436 : : }
437 : :
438 : : /* Instantiate Coroutine traits for the function signature. */
439 : :
440 : : static tree
441 : 2688 : instantiate_coro_traits (tree fndecl, location_t kw)
442 : : {
443 : : /* [coroutine.traits.primary]
444 : : So now build up a type list for the template <typename _R, typename...>.
445 : : The types are the function's arg types and _R is the function return
446 : : type. */
447 : :
448 : 2688 : tree functyp = TREE_TYPE (fndecl);
449 : 2688 : tree arg = DECL_ARGUMENTS (fndecl);
450 : 2688 : tree arg_node = TYPE_ARG_TYPES (functyp);
451 : 2688 : tree argtypes = make_tree_vec (list_length (arg_node)-1);
452 : 2688 : unsigned p = 0;
453 : :
454 : 21690 : while (arg_node != NULL_TREE && !VOID_TYPE_P (TREE_VALUE (arg_node)))
455 : : {
456 : 6813 : if (is_this_parameter (arg)
457 : 6813 : || DECL_NAME (arg) == closure_identifier)
458 : : {
459 : : /* We pass a reference to *this to the param preview. */
460 : 1416 : tree ct = TREE_TYPE (TREE_TYPE (arg));
461 : 1416 : TREE_VEC_ELT (argtypes, p++) = cp_build_reference_type (ct, false);
462 : : }
463 : : else
464 : 5397 : TREE_VEC_ELT (argtypes, p++) = TREE_VALUE (arg_node);
465 : :
466 : 6813 : arg_node = TREE_CHAIN (arg_node);
467 : 6813 : arg = DECL_CHAIN (arg);
468 : : }
469 : :
470 : 2688 : tree argtypepack = cxx_make_type (TYPE_ARGUMENT_PACK);
471 : 2688 : ARGUMENT_PACK_ARGS (argtypepack) = argtypes;
472 : :
473 : 2688 : tree targ = make_tree_vec (2);
474 : 2688 : TREE_VEC_ELT (targ, 0) = TREE_TYPE (functyp);
475 : 2688 : TREE_VEC_ELT (targ, 1) = argtypepack;
476 : :
477 : 2688 : tree traits_class
478 : 2688 : = lookup_template_class (coro_traits_templ, targ,
479 : : /*in_decl=*/NULL_TREE, /*context=*/NULL_TREE,
480 : : tf_warning_or_error);
481 : :
482 : 2688 : if (traits_class == error_mark_node)
483 : : {
484 : 0 : error_at (kw, "cannot instantiate %<coroutine traits%>");
485 : 0 : return NULL_TREE;
486 : : }
487 : :
488 : : return traits_class;
489 : : }
490 : :
491 : : /* [coroutine.handle] */
492 : :
493 : : static tree
494 : 2331 : find_coro_handle_template_decl (location_t kw)
495 : : {
496 : : /* As for the coroutine traits, this error is per TU, so only emit
497 : : it once. */
498 : 2331 : static bool coro_handle_error_emitted = false;
499 : 4662 : tree handle_decl = lookup_qualified_name (std_node, coro_handle_identifier,
500 : : LOOK_want::NORMAL,
501 : 2331 : !coro_handle_error_emitted);
502 : 2331 : if (handle_decl == error_mark_node
503 : 2331 : || !DECL_CLASS_TEMPLATE_P (handle_decl))
504 : : {
505 : 6 : if (!coro_handle_error_emitted)
506 : 2 : error_at (kw, "coroutines require a handle class template;"
507 : : " cannot find %<%E::%E%>", std_node, coro_handle_identifier);
508 : 6 : coro_handle_error_emitted = true;
509 : 6 : return NULL_TREE;
510 : : }
511 : : else
512 : : return handle_decl;
513 : : }
514 : :
515 : : /* Get and validate HANDLE_TYPE::address. The resulting function, if any, will
516 : : be a non-overloaded member function that takes no arguments and returns
517 : : void*. If that is not the case, signals an error and returns NULL_TREE. */
518 : :
519 : : static tree
520 : 2325 : get_handle_type_address (location_t kw, tree handle_type)
521 : : {
522 : 2325 : tree addr_getter = lookup_member (handle_type, coro_address_identifier, 1,
523 : : 0, tf_warning_or_error);
524 : 2325 : if (!addr_getter || addr_getter == error_mark_node)
525 : : {
526 : 6 : qualified_name_lookup_error (handle_type, coro_address_identifier,
527 : : error_mark_node, kw);
528 : 6 : return NULL_TREE;
529 : : }
530 : :
531 : 2319 : if (!BASELINK_P (addr_getter)
532 : 2319 : || TREE_CODE (TREE_TYPE (addr_getter)) != METHOD_TYPE)
533 : : {
534 : 6 : error_at (kw, "%qE must be a non-overloaded method", addr_getter);
535 : 6 : return NULL_TREE;
536 : : }
537 : :
538 : 2313 : tree fn_t = TREE_TYPE (addr_getter);
539 : 2313 : tree arg = TYPE_ARG_TYPES (fn_t);
540 : :
541 : : /* Skip the 'this' pointer. */
542 : 2313 : arg = TREE_CHAIN (arg);
543 : :
544 : : /* Check that from_addr has the argument list (). */
545 : 2313 : if (arg != void_list_node)
546 : : {
547 : 0 : error_at (kw, "%qE must take no arguments", addr_getter);
548 : 0 : return NULL_TREE;
549 : : }
550 : :
551 : 2313 : tree ret_t = TREE_TYPE (fn_t);
552 : 2313 : if (!same_type_p (ret_t, ptr_type_node))
553 : : {
554 : 0 : error_at (kw, "%qE must return %qT, not %qT",
555 : : addr_getter, ptr_type_node, ret_t);
556 : 0 : return NULL_TREE;
557 : : }
558 : :
559 : : return addr_getter;
560 : : }
561 : :
562 : : /* Get and validate HANDLE_TYPE::from_address. The resulting function, if
563 : : any, will be a non-overloaded static function that takes a single void* and
564 : : returns HANDLE_TYPE. If that is not the case, signals an error and returns
565 : : NULL_TREE. */
566 : :
567 : : static tree
568 : 1370 : get_handle_type_from_address (location_t kw, tree handle_type)
569 : : {
570 : 1370 : tree from_addr = lookup_member (handle_type, coro_from_address_identifier, 1,
571 : : 0, tf_warning_or_error);
572 : 1370 : if (!from_addr || from_addr == error_mark_node)
573 : : {
574 : 2 : qualified_name_lookup_error (handle_type, coro_from_address_identifier,
575 : : error_mark_node, kw);
576 : 2 : return NULL_TREE;
577 : : }
578 : 1368 : if (!BASELINK_P (from_addr)
579 : 1368 : || TREE_CODE (TREE_TYPE (from_addr)) != FUNCTION_TYPE)
580 : : {
581 : 1 : error_at (kw, "%qE must be a non-overloaded static function", from_addr);
582 : 1 : return NULL_TREE;
583 : : }
584 : :
585 : 1367 : tree fn_t = TREE_TYPE (from_addr);
586 : 1367 : tree arg = TYPE_ARG_TYPES (fn_t);
587 : : /* Check that from_addr has the argument list (void*). */
588 : 1367 : if (!arg
589 : 1367 : || !same_type_p (TREE_VALUE (arg), ptr_type_node)
590 : 2734 : || TREE_CHAIN (arg) != void_list_node)
591 : : {
592 : 0 : error_at (kw, "%qE must take a single %qT", from_addr, ptr_type_node);
593 : 0 : return NULL_TREE;
594 : : }
595 : :
596 : 1367 : tree ret_t = TREE_TYPE (fn_t);
597 : 1367 : if (!same_type_p (ret_t, handle_type))
598 : : {
599 : 0 : error_at (kw, "%qE must return %qT, not %qT",
600 : : from_addr, handle_type, ret_t);
601 : 0 : return NULL_TREE;
602 : : }
603 : :
604 : : return from_addr;
605 : : }
606 : :
607 : : static tree
608 : 3695 : instantiate_coro_handle_for_promise_type (location_t kw, tree promise_type)
609 : : {
610 : : /* So now build up a type list for the template, one entry, the promise. */
611 : 3695 : tree targ = make_tree_vec (1);
612 : 3695 : TREE_VEC_ELT (targ, 0) = promise_type;
613 : 3695 : tree handle_type
614 : 3695 : = lookup_template_class (coro_handle_identifier, targ,
615 : : /* in_decl=*/NULL_TREE,
616 : : /* context=*/std_node,
617 : : tf_warning_or_error);
618 : :
619 : 3695 : if (handle_type == error_mark_node)
620 : : {
621 : 0 : error_at (kw, "cannot instantiate a %<coroutine handle%> for"
622 : : " promise type %qT", promise_type);
623 : 0 : return NULL_TREE;
624 : : }
625 : :
626 : : return handle_type;
627 : : }
628 : :
629 : : /* Look for the promise_type in the instantiated traits. */
630 : :
631 : : static tree
632 : 1378 : find_promise_type (tree traits_class)
633 : : {
634 : 1378 : tree promise_type
635 : 1378 : = lookup_member (traits_class, coro_promise_type_identifier,
636 : : /* protect=*/1, /*want_type=*/true, tf_warning_or_error);
637 : :
638 : 1378 : if (promise_type)
639 : 1372 : promise_type
640 : 1372 : = complete_type_or_else (TREE_TYPE (promise_type), promise_type);
641 : :
642 : : /* NULL_TREE on fail. */
643 : 1378 : return promise_type;
644 : : }
645 : :
646 : : /* Perform initialization of the coroutine processor state, if not done
647 : : before. */
648 : :
649 : : static bool
650 : 7745 : ensure_coro_initialized (location_t loc)
651 : : {
652 : 7745 : if (!coro_initialized)
653 : : {
654 : : /* Trees we only need to create once.
655 : : Set up the identifiers we will use. */
656 : 2341 : coro_init_identifiers ();
657 : :
658 : : /* Coroutine traits template. */
659 : 2341 : coro_traits_templ = find_coro_traits_template_decl (loc);
660 : 2341 : if (coro_traits_templ == NULL_TREE)
661 : : return false;
662 : :
663 : : /* coroutine_handle<> template. */
664 : 2331 : coro_handle_templ = find_coro_handle_template_decl (loc);
665 : 2331 : if (coro_handle_templ == NULL_TREE)
666 : : return false;
667 : :
668 : : /* We can also instantiate the void coroutine_handle<> */
669 : 2325 : void_coro_handle_type
670 : 2325 : = instantiate_coro_handle_for_promise_type (loc, void_type_node);
671 : 2325 : if (void_coro_handle_type == NULL_TREE)
672 : : return false;
673 : :
674 : 2325 : void_coro_handle_address
675 : 2325 : = get_handle_type_address (loc, void_coro_handle_type);
676 : 2325 : if (!void_coro_handle_address)
677 : : return false;
678 : :
679 : : /* A table to hold the state, per coroutine decl. */
680 : 2313 : gcc_checking_assert (coroutine_info_table == NULL);
681 : 4626 : coroutine_info_table =
682 : 2313 : hash_table<coroutine_info_hasher>::create_ggc (11);
683 : :
684 : 2313 : if (coroutine_info_table == NULL)
685 : : return false;
686 : :
687 : 2313 : coro_initialized = true;
688 : : }
689 : : return true;
690 : : }
691 : :
692 : : /* Try to get the coroutine traits class. */
693 : : static tree
694 : 5288 : coro_get_traits_class (tree fndecl, location_t loc)
695 : : {
696 : 5288 : gcc_assert (fndecl != NULL_TREE);
697 : 5288 : gcc_assert (coro_initialized);
698 : :
699 : 5288 : coroutine_info *coro_info = get_or_insert_coroutine_info (fndecl);
700 : 5288 : auto& traits_type = coro_info->traits_type;
701 : 5288 : if (!traits_type)
702 : 2688 : traits_type = instantiate_coro_traits (fndecl, loc);
703 : 5288 : return traits_type;
704 : : }
705 : :
706 : : static bool
707 : 3819 : coro_promise_type_found_p (tree fndecl, location_t loc)
708 : : {
709 : 3819 : gcc_assert (fndecl != NULL_TREE);
710 : :
711 : 3819 : if (!ensure_coro_initialized (loc))
712 : : return false;
713 : :
714 : : /* Save the coroutine data on the side to avoid the overhead on every
715 : : function decl tree. */
716 : :
717 : 3807 : coroutine_info *coro_info = get_or_insert_coroutine_info (fndecl);
718 : : /* Without this, we cannot really proceed. */
719 : 3807 : gcc_checking_assert (coro_info);
720 : :
721 : : /* If we don't already have a current promise type, try to look it up. */
722 : 3807 : if (coro_info->promise_type == NULL_TREE)
723 : : {
724 : : /* Get the coroutine traits template class instance for the function
725 : : signature we have - coroutine_traits <R, ...> */
726 : :
727 : 1378 : tree templ_class = coro_get_traits_class (fndecl, loc);
728 : :
729 : : /* Find the promise type for that. */
730 : 1378 : coro_info->promise_type = find_promise_type (templ_class);
731 : :
732 : : /* If we don't find it, punt on the rest. */
733 : 1378 : if (coro_info->promise_type == NULL_TREE)
734 : : {
735 : 6 : if (!coro_info->coro_promise_error_emitted)
736 : 2 : error_at (loc, "unable to find the promise type for"
737 : : " this coroutine");
738 : 6 : coro_info->coro_promise_error_emitted = true;
739 : 6 : return false;
740 : : }
741 : :
742 : : /* Test for errors in the promise type that can be determined now. */
743 : 1372 : tree has_ret_void = lookup_member (coro_info->promise_type,
744 : : coro_return_void_identifier,
745 : : /*protect=*/1, /*want_type=*/0,
746 : : tf_none);
747 : 1372 : tree has_ret_val = lookup_member (coro_info->promise_type,
748 : : coro_return_value_identifier,
749 : : /*protect=*/1, /*want_type=*/0,
750 : : tf_none);
751 : 1372 : if (has_ret_void && has_ret_val)
752 : : {
753 : 2 : auto_diagnostic_group d;
754 : 2 : location_t ploc = DECL_SOURCE_LOCATION (fndecl);
755 : 2 : if (!coro_info->coro_co_return_error_emitted)
756 : 2 : error_at (ploc, "the coroutine promise type %qT declares both"
757 : : " %<return_value%> and %<return_void%>",
758 : : coro_info->promise_type);
759 : 2 : inform (DECL_SOURCE_LOCATION (BASELINK_FUNCTIONS (has_ret_void)),
760 : : "%<return_void%> declared here");
761 : 2 : has_ret_val = BASELINK_FUNCTIONS (has_ret_val);
762 : 2 : const char *message = "%<return_value%> declared here";
763 : 2 : if (TREE_CODE (has_ret_val) == OVERLOAD)
764 : : {
765 : 2 : has_ret_val = OVL_FIRST (has_ret_val);
766 : : message = "%<return_value%> first declared here";
767 : : }
768 : 2 : inform (DECL_SOURCE_LOCATION (has_ret_val), message);
769 : 2 : coro_info->coro_co_return_error_emitted = true;
770 : 2 : return false;
771 : 2 : }
772 : :
773 : : /* Try to find the handle type for the promise. */
774 : 1370 : tree handle_type
775 : 1370 : = instantiate_coro_handle_for_promise_type (loc, coro_info->promise_type);
776 : 1370 : if (handle_type == NULL_TREE)
777 : : return false;
778 : 1370 : tree from_address = get_handle_type_from_address (loc, handle_type);
779 : 1370 : if (from_address == NULL_TREE)
780 : : return false;
781 : :
782 : : /* Complete this, we're going to use it. */
783 : 1367 : coro_info->handle_type = complete_type_or_else (handle_type, fndecl);
784 : 1367 : coro_info->from_address = from_address;
785 : :
786 : : /* Diagnostic would be emitted by complete_type_or_else. */
787 : 1367 : if (!coro_info->handle_type)
788 : : return false;
789 : :
790 : : /* Build a proxy for a handle to "self" as the param to
791 : : await_suspend() calls. */
792 : 1367 : coro_info->self_h_proxy
793 : 1367 : = build_lang_decl (VAR_DECL, coro_self_handle_id,
794 : : coro_info->handle_type);
795 : :
796 : : /* Build a proxy for the promise so that we can perform lookups. */
797 : 1367 : coro_info->promise_proxy
798 : 1367 : = build_lang_decl (VAR_DECL, coro_promise_id,
799 : : coro_info->promise_type);
800 : :
801 : : /* Note where we first saw a coroutine keyword. */
802 : 1367 : coro_info->first_coro_keyword = loc;
803 : : }
804 : :
805 : : return true;
806 : : }
807 : :
808 : : /* Map from actor or destroyer to ramp. */
809 : : static GTY(()) hash_map<tree, tree> *to_ramp;
810 : :
811 : : /* Given a tree that is an actor or destroy, find the ramp function. */
812 : :
813 : : tree
814 : 134744566 : coro_get_ramp_function (tree decl)
815 : : {
816 : 134744566 : if (!to_ramp)
817 : : return NULL_TREE;
818 : 497490 : tree *p = to_ramp->get (decl);
819 : 497490 : if (p)
820 : 2981 : return *p;
821 : : return NULL_TREE;
822 : : }
823 : :
824 : : /* Given the DECL for a ramp function (the user's original declaration) return
825 : : the actor function if it has been defined. */
826 : :
827 : : tree
828 : 2636 : coro_get_actor_function (tree decl)
829 : : {
830 : 2636 : if (coroutine_info *info = get_coroutine_info (decl))
831 : 2636 : return info->actor_decl;
832 : :
833 : : return NULL_TREE;
834 : : }
835 : :
836 : : /* Given the DECL for a ramp function (the user's original declaration) return
837 : : the destroy function if it has been defined. */
838 : :
839 : : tree
840 : 1318 : coro_get_destroy_function (tree decl)
841 : : {
842 : 1318 : if (coroutine_info *info = get_coroutine_info (decl))
843 : 1318 : return info->destroy_decl;
844 : :
845 : : return NULL_TREE;
846 : : }
847 : :
848 : : /* Given a CO_AWAIT_EXPR AWAIT_EXPR, return its resume call. */
849 : :
850 : : tree
851 : 112 : co_await_get_resume_call (tree await_expr)
852 : : {
853 : 112 : gcc_checking_assert (TREE_CODE (await_expr) == CO_AWAIT_EXPR);
854 : 112 : tree vec = TREE_OPERAND (await_expr, 3);
855 : 112 : if (!vec)
856 : : return nullptr;
857 : 108 : return TREE_VEC_ELT (vec, 2);
858 : : }
859 : :
860 : :
861 : : /* These functions assumes that the caller has verified that the state for
862 : : the decl has been initialized, we try to minimize work here. */
863 : :
864 : : static tree
865 : 18428 : get_coroutine_promise_type (tree decl)
866 : : {
867 : 18428 : if (coroutine_info *info = get_coroutine_info (decl))
868 : 17078 : return info->promise_type;
869 : :
870 : : return NULL_TREE;
871 : : }
872 : :
873 : : static tree
874 : 1355 : get_coroutine_handle_type (tree decl)
875 : : {
876 : 1355 : if (coroutine_info *info = get_coroutine_info (decl))
877 : 0 : return info->handle_type;
878 : :
879 : : return NULL_TREE;
880 : : }
881 : :
882 : : static tree
883 : 5064 : get_coroutine_self_handle_proxy (tree decl)
884 : : {
885 : 5064 : if (coroutine_info *info = get_coroutine_info (decl))
886 : 5064 : return info->self_h_proxy;
887 : :
888 : : return NULL_TREE;
889 : : }
890 : :
891 : : static tree
892 : 7470 : get_coroutine_promise_proxy (tree decl)
893 : : {
894 : 7470 : if (coroutine_info *info = get_coroutine_info (decl))
895 : 7470 : return info->promise_proxy;
896 : :
897 : : return NULL_TREE;
898 : : }
899 : :
900 : : static tree
901 : 1338 : get_coroutine_from_address (tree decl)
902 : : {
903 : 1338 : if (coroutine_info *info = get_coroutine_info (decl))
904 : 0 : return info->from_address;
905 : :
906 : : return NULL_TREE;
907 : : }
908 : :
909 : : static tree
910 : 11696 : lookup_promise_method (tree fndecl, tree member_id, location_t loc,
911 : : bool musthave)
912 : : {
913 : 11696 : tree promise = get_coroutine_promise_type (fndecl);
914 : 11696 : tree pm_memb
915 : 11696 : = lookup_member (promise, member_id,
916 : : /*protect=*/1, /*want_type=*/0, tf_warning_or_error);
917 : 11696 : if (musthave && pm_memb == NULL_TREE)
918 : : {
919 : 7 : error_at (loc, "no member named %qE in %qT", member_id, promise);
920 : 7 : return error_mark_node;
921 : : }
922 : : return pm_memb;
923 : : }
924 : :
925 : : /* Build an expression of the form p.method (args) where the p is a promise
926 : : object for the current coroutine.
927 : : OBJECT is the promise object instance to use, it may be NULL, in which case
928 : : we will use the promise_proxy instance for this coroutine.
929 : : ARGS may be NULL, for empty parm lists. */
930 : :
931 : : static tree
932 : 8200 : coro_build_promise_expression (tree fn, tree promise_obj, tree member_id,
933 : : location_t loc, vec<tree, va_gc> **args,
934 : : bool musthave)
935 : : {
936 : 8200 : tree meth = lookup_promise_method (fn, member_id, loc, musthave);
937 : 8200 : if (meth == error_mark_node)
938 : : return error_mark_node;
939 : :
940 : : /* If we don't find it, and it isn't needed, an empty return is OK. */
941 : 8194 : if (!meth)
942 : : return NULL_TREE;
943 : :
944 : 7294 : tree promise
945 : 7294 : = promise_obj ? promise_obj
946 : 4582 : : get_coroutine_promise_proxy (current_function_decl);
947 : 7294 : tree expr;
948 : 7294 : if (BASELINK_P (meth))
949 : 7182 : expr = build_new_method_call (promise, meth, args, NULL_TREE,
950 : : LOOKUP_NORMAL, NULL, tf_warning_or_error);
951 : : else
952 : : {
953 : 112 : expr = build_class_member_access_expr (promise, meth, NULL_TREE,
954 : : true, tf_warning_or_error);
955 : 112 : vec<tree, va_gc> *real_args;
956 : 112 : if (!args)
957 : 80 : real_args = make_tree_vector ();
958 : : else
959 : 32 : real_args = *args;
960 : 112 : expr = build_op_call (expr, &real_args, tf_warning_or_error);
961 : : }
962 : : return expr;
963 : : }
964 : :
965 : : /* Caching get for the expression p.return_void (). */
966 : :
967 : : static tree
968 : 1682 : get_coroutine_return_void_expr (tree decl, location_t loc, bool musthave)
969 : : {
970 : 1682 : if (coroutine_info *info = get_coroutine_info (decl))
971 : : {
972 : : /* If we don't have it try to build it. */
973 : 1682 : if (!info->return_void)
974 : 1351 : info->return_void
975 : 1351 : = coro_build_promise_expression (current_function_decl, NULL,
976 : : coro_return_void_identifier,
977 : : loc, NULL, musthave);
978 : : /* Don't return an error if it's an optional call. */
979 : 1682 : if (!musthave && info->return_void == error_mark_node)
980 : : return NULL_TREE;
981 : 1681 : return info->return_void;
982 : : }
983 : 0 : return musthave ? error_mark_node : NULL_TREE;
984 : : }
985 : :
986 : : /* Lookup an Awaitable member, which should be await_ready, await_suspend
987 : : or await_resume. */
988 : :
989 : : static tree
990 : 11158 : lookup_awaitable_member (tree await_type, tree member_id, location_t loc)
991 : : {
992 : 11158 : tree aw_memb
993 : 11158 : = lookup_member (await_type, member_id,
994 : : /*protect=*/1, /*want_type=*/0, tf_warning_or_error);
995 : 11158 : if (aw_memb == NULL_TREE)
996 : : {
997 : 5 : error_at (loc, "no member named %qE in %qT", member_id, await_type);
998 : 5 : return error_mark_node;
999 : : }
1000 : : return aw_memb;
1001 : : }
1002 : :
1003 : : /* Here we check the constraints that are common to all keywords (since the
1004 : : presence of a coroutine keyword makes the function into a coroutine). */
1005 : :
1006 : : static bool
1007 : 3951 : coro_common_keyword_context_valid_p (tree fndecl, location_t kw_loc,
1008 : : const char *kw_name)
1009 : : {
1010 : 3951 : if (fndecl == NULL_TREE)
1011 : : {
1012 : 4 : error_at (kw_loc, "%qs cannot be used outside a function", kw_name);
1013 : 4 : return false;
1014 : : }
1015 : :
1016 : : /* This is arranged in order of prohibitions in the std. */
1017 : 3947 : if (DECL_MAIN_P (fndecl))
1018 : : {
1019 : : /* [basic.start.main] 3. The function main shall not be a coroutine. */
1020 : 3 : error_at (kw_loc, "%qs cannot be used in the %<main%> function",
1021 : : kw_name);
1022 : 3 : return false;
1023 : : }
1024 : :
1025 : 3944 : if (DECL_DECLARED_CONSTEXPR_P (fndecl))
1026 : : {
1027 : 5 : cp_function_chain->invalid_constexpr = true;
1028 : 5 : if (!is_instantiation_of_constexpr (fndecl))
1029 : : {
1030 : : /* [dcl.constexpr] 3.3 it shall not be a coroutine. */
1031 : 3 : error_at (kw_loc, "%qs cannot be used in a %<constexpr%> function",
1032 : : kw_name);
1033 : 3 : return false;
1034 : : }
1035 : : }
1036 : :
1037 : 3941 : if (FNDECL_USED_AUTO (fndecl))
1038 : : {
1039 : : /* [dcl.spec.auto] 15. A function declared with a return type that uses
1040 : : a placeholder type shall not be a coroutine. */
1041 : 6 : error_at (kw_loc,
1042 : : "%qs cannot be used in a function with a deduced return type",
1043 : : kw_name);
1044 : 6 : return false;
1045 : : }
1046 : :
1047 : 3935 : if (varargs_function_p (fndecl))
1048 : : {
1049 : : /* [dcl.fct.def.coroutine] The parameter-declaration-clause of the
1050 : : coroutine shall not terminate with an ellipsis that is not part
1051 : : of a parameter-declaration. */
1052 : 3 : error_at (kw_loc,
1053 : : "%qs cannot be used in a varargs function", kw_name);
1054 : 3 : return false;
1055 : : }
1056 : :
1057 : 7864 : if (DECL_CONSTRUCTOR_P (fndecl))
1058 : : {
1059 : : /* [class.ctor] 7. a constructor shall not be a coroutine. */
1060 : 3 : error_at (kw_loc, "%qs cannot be used in a constructor", kw_name);
1061 : 3 : return false;
1062 : : }
1063 : :
1064 : 3929 : if (DECL_DESTRUCTOR_P (fndecl))
1065 : : {
1066 : : /* [class.dtor] 21. a destructor shall not be a coroutine. */
1067 : 3 : error_at (kw_loc, "%qs cannot be used in a destructor", kw_name);
1068 : 3 : return false;
1069 : : }
1070 : :
1071 : : return true;
1072 : : }
1073 : :
1074 : : /* Here we check the constraints that are not per keyword. */
1075 : :
1076 : : static bool
1077 : 1369 : coro_function_valid_p (tree fndecl)
1078 : : {
1079 : 1369 : location_t f_loc = DECL_SOURCE_LOCATION (fndecl);
1080 : :
1081 : : /* For cases where fundamental information cannot be found, e.g. the
1082 : : coroutine traits are missing, we need to punt early. */
1083 : 1369 : if (!coro_promise_type_found_p (fndecl, f_loc))
1084 : : return false;
1085 : :
1086 : : /* Since we think the function is a coroutine, that implies we parsed
1087 : : a keyword that triggered this. Keywords check promise validity for
1088 : : their context and thus the promise type should be known at this point. */
1089 : 1355 : if (get_coroutine_handle_type (fndecl) == NULL_TREE
1090 : 2705 : || get_coroutine_promise_type (fndecl) == NULL_TREE)
1091 : 5 : return false;
1092 : :
1093 : 1350 : if (current_function_returns_value || current_function_returns_null)
1094 : : {
1095 : : /* TODO: record or extract positions of returns (and the first coro
1096 : : keyword) so that we can add notes to the diagnostic about where
1097 : : the bad keyword is and what made the function into a coro. */
1098 : 1 : error_at (f_loc, "a %<return%> statement is not allowed in coroutine;"
1099 : : " did you mean %<co_return%>?");
1100 : 1 : return false;
1101 : : }
1102 : :
1103 : : return true;
1104 : : }
1105 : :
1106 : : enum suspend_point_kind {
1107 : : CO_AWAIT_SUSPEND_POINT = 0,
1108 : : CO_YIELD_SUSPEND_POINT,
1109 : : INITIAL_SUSPEND_POINT,
1110 : : FINAL_SUSPEND_POINT
1111 : : };
1112 : :
1113 : : /* Helper function to build a named variable for the temps we use for each
1114 : : await point. The root of the name is determined by SUSPEND_KIND, and
1115 : : the variable is of type V_TYPE. The awaitable number is reset each time
1116 : : we encounter a final suspend. */
1117 : :
1118 : : static tree
1119 : 3635 : get_awaitable_var (suspend_point_kind suspend_kind, tree v_type)
1120 : : {
1121 : 3635 : auto cinfo = get_coroutine_info (current_function_decl);
1122 : 3635 : gcc_checking_assert (cinfo);
1123 : 3635 : char *buf;
1124 : 3635 : switch (suspend_kind)
1125 : : {
1126 : 584 : default: buf = xasprintf ("Aw%d", cinfo->awaitable_number++); break;
1127 : 363 : case CO_YIELD_SUSPEND_POINT:
1128 : 363 : buf = xasprintf ("Yd%d", cinfo->awaitable_number++);
1129 : 363 : break;
1130 : 1346 : case INITIAL_SUSPEND_POINT: buf = xasprintf ("Is"); break;
1131 : 1342 : case FINAL_SUSPEND_POINT: buf = xasprintf ("Fs"); break;
1132 : : }
1133 : 3635 : tree ret = get_identifier (buf);
1134 : 3635 : free (buf);
1135 : 3635 : ret = build_lang_decl (VAR_DECL, ret, v_type);
1136 : 3635 : DECL_ARTIFICIAL (ret) = true;
1137 : 3635 : return ret;
1138 : : }
1139 : :
1140 : : /* Helpers to diagnose missing noexcept on final await expressions. */
1141 : :
1142 : : static bool
1143 : 6135 : coro_diagnose_throwing_fn (tree fndecl)
1144 : : {
1145 : 6135 : if (!TYPE_NOTHROW_P (TREE_TYPE (fndecl)))
1146 : : {
1147 : 7 : auto_diagnostic_group d;
1148 : 7 : location_t f_loc = cp_expr_loc_or_loc (fndecl,
1149 : 7 : DECL_SOURCE_LOCATION (fndecl));
1150 : 7 : error_at (f_loc, "the expression %qE is required to be non-throwing",
1151 : : fndecl);
1152 : 7 : inform (f_loc, "must be declared with %<noexcept(true)%>");
1153 : 7 : return true;
1154 : 7 : }
1155 : : return false;
1156 : : }
1157 : :
1158 : : static bool
1159 : 1347 : coro_diagnose_throwing_final_aw_expr (tree expr)
1160 : : {
1161 : 1347 : if (TREE_CODE (expr) == TARGET_EXPR)
1162 : 1346 : expr = TARGET_EXPR_INITIAL (expr);
1163 : 1347 : tree fn = NULL_TREE;
1164 : 1347 : if (TREE_CODE (expr) == CALL_EXPR)
1165 : 552 : fn = CALL_EXPR_FN (expr);
1166 : 795 : else if (TREE_CODE (expr) == AGGR_INIT_EXPR)
1167 : 795 : fn = AGGR_INIT_EXPR_FN (expr);
1168 : 0 : else if (TREE_CODE (expr) == CONSTRUCTOR)
1169 : : return false;
1170 : : else
1171 : : {
1172 : 0 : gcc_checking_assert (0 && "unhandled expression type");
1173 : : return false;
1174 : : }
1175 : 1347 : fn = TREE_OPERAND (fn, 0);
1176 : 1347 : return coro_diagnose_throwing_fn (fn);
1177 : : }
1178 : :
1179 : : /* Build a co_await suitable for later expansion. */
1180 : :
1181 : : tree
1182 : 120 : build_template_co_await_expr (location_t kw, tree type, tree expr, tree kind)
1183 : : {
1184 : 120 : tree aw_expr = build5_loc (kw, CO_AWAIT_EXPR, type, expr,
1185 : : NULL_TREE, NULL_TREE, NULL_TREE,
1186 : : kind);
1187 : 120 : TREE_SIDE_EFFECTS (aw_expr) = true;
1188 : 120 : return aw_expr;
1189 : : }
1190 : :
1191 : :
1192 : : /* This performs [expr.await] bullet 3.3 and validates the interface obtained.
1193 : : It is also used to build the initial and final suspend points.
1194 : :
1195 : : 'a', 'o' and 'e' are used as per the description in the section noted.
1196 : :
1197 : : A, the original yield/await expr, is found at source location LOC.
1198 : :
1199 : : We will be constructing a CO_AWAIT_EXPR for a suspend point of one of
1200 : : the four suspend_point_kind kinds. This is indicated by SUSPEND_KIND.
1201 : :
1202 : : In the case that we're processing a template declaration, we can't save
1203 : : actual awaiter expressions as the frame type will differ between
1204 : : instantiations, but we can generate them to type-check them and compute the
1205 : : resulting expression type. In those cases, we will return a
1206 : : template-appropriate CO_AWAIT_EXPR and throw away the rest of the results.
1207 : : Such an expression requires the original co_await operand unaltered. Pass
1208 : : it as ORIG_OPERAND. If it is the same as 'a', you can pass NULL_TREE (the
1209 : : default) to use 'a' as the value. */
1210 : :
1211 : : static tree
1212 : 3728 : build_co_await (location_t loc, tree a, suspend_point_kind suspend_kind,
1213 : : tree orig_operand = NULL_TREE)
1214 : : {
1215 : 3728 : if (orig_operand == NULL_TREE)
1216 : 3061 : orig_operand = a;
1217 : :
1218 : : /* Try and overload of operator co_await, .... */
1219 : 3728 : tree o;
1220 : 3728 : if (MAYBE_CLASS_TYPE_P (TREE_TYPE (a)))
1221 : : {
1222 : 3723 : o = build_new_op (loc, CO_AWAIT_EXPR, LOOKUP_NORMAL, a, NULL_TREE,
1223 : : NULL_TREE, NULL_TREE, NULL, tf_warning_or_error);
1224 : : /* If no viable functions are found, o is a. */
1225 : 3723 : if (!o || o == error_mark_node)
1226 : : o = a;
1227 : 118 : else if (flag_exceptions && suspend_kind == FINAL_SUSPEND_POINT)
1228 : : {
1229 : : /* We found an overload for co_await(), diagnose throwing cases. */
1230 : 7 : if (TREE_CODE (o) == TARGET_EXPR
1231 : 7 : && coro_diagnose_throwing_final_aw_expr (o))
1232 : 1 : return error_mark_node;
1233 : :
1234 : : /* We now know that the final suspend object is distinct from the
1235 : : final awaiter, so check for a non-throwing DTOR where needed. */
1236 : 6 : if (tree dummy = cxx_maybe_build_cleanup (a, tf_none))
1237 : : {
1238 : 5 : if (CONVERT_EXPR_P (dummy))
1239 : 0 : dummy = TREE_OPERAND (dummy, 0);
1240 : 5 : dummy = TREE_OPERAND (CALL_EXPR_FN (dummy), 0);
1241 : 5 : if (coro_diagnose_throwing_fn (dummy))
1242 : 1 : return error_mark_node;
1243 : : }
1244 : : }
1245 : : }
1246 : : else
1247 : : o = a; /* This is most likely about to fail anyway. */
1248 : :
1249 : 3726 : tree o_type = TREE_TYPE (o);
1250 : 3726 : if (o_type && !VOID_TYPE_P (o_type))
1251 : 3725 : o_type = complete_type_or_else (o_type, o);
1252 : :
1253 : 3725 : if (!o_type)
1254 : 3 : return error_mark_node;
1255 : :
1256 : 3723 : if (TREE_CODE (o_type) != RECORD_TYPE)
1257 : : {
1258 : 2 : error_at (loc, "awaitable type %qT is not a structure",
1259 : : o_type);
1260 : 2 : return error_mark_node;
1261 : : }
1262 : :
1263 : : /* Check for required awaitable members and their types. */
1264 : 3721 : tree awrd_meth
1265 : 3721 : = lookup_awaitable_member (o_type, coro_await_ready_identifier, loc);
1266 : 3721 : if (!awrd_meth || awrd_meth == error_mark_node)
1267 : 1 : return error_mark_node;
1268 : 3720 : tree awsp_meth
1269 : 3720 : = lookup_awaitable_member (o_type, coro_await_suspend_identifier, loc);
1270 : 3720 : if (!awsp_meth || awsp_meth == error_mark_node)
1271 : 3 : return error_mark_node;
1272 : :
1273 : : /* The type of the co_await is the return type of the awaitable's
1274 : : await_resume, so we need to look that up. */
1275 : 3717 : tree awrs_meth
1276 : 3717 : = lookup_awaitable_member (o_type, coro_await_resume_identifier, loc);
1277 : 3717 : if (!awrs_meth || awrs_meth == error_mark_node)
1278 : 1 : return error_mark_node;
1279 : :
1280 : : /* [expr.await]/3.3 If o would be a prvalue, the temporary
1281 : : materialization conversion ([conv.rval]) is applied. */
1282 : 3716 : if (!glvalue_p (o))
1283 : 3635 : o = get_target_expr (o, tf_warning_or_error);
1284 : :
1285 : 3716 : tree e_proxy = o;
1286 : 3716 : if (glvalue_p (o))
1287 : : o = NULL_TREE; /* Use the existing entity. */
1288 : : else /* We need to materialise it. */
1289 : : {
1290 : 3635 : e_proxy = get_awaitable_var (suspend_kind, o_type);
1291 : 3635 : o = cp_build_init_expr (loc, e_proxy, o);
1292 : 3635 : e_proxy = convert_from_reference (e_proxy);
1293 : : }
1294 : :
1295 : : /* I suppose we could check that this is contextually convertible to bool. */
1296 : 3716 : tree awrd_func = NULL_TREE;
1297 : 3716 : tree awrd_call
1298 : 3716 : = build_new_method_call (e_proxy, awrd_meth, NULL, NULL_TREE, LOOKUP_NORMAL,
1299 : : &awrd_func, tf_warning_or_error);
1300 : :
1301 : 3716 : if (!awrd_func || !awrd_call || awrd_call == error_mark_node)
1302 : 0 : return error_mark_node;
1303 : :
1304 : : /* The suspend method may return one of three types:
1305 : : 1. void (no special action needed).
1306 : : 2. bool (if true, we don't need to suspend).
1307 : : 3. a coroutine handle, we execute the handle.resume() call. */
1308 : 3716 : tree awsp_func = NULL_TREE;
1309 : 3716 : tree h_proxy = get_coroutine_self_handle_proxy (current_function_decl);
1310 : 3716 : vec<tree, va_gc> *args = make_tree_vector_single (h_proxy);
1311 : 3716 : tree awsp_call
1312 : 3716 : = build_new_method_call (e_proxy, awsp_meth, &args, NULL_TREE,
1313 : : LOOKUP_NORMAL, &awsp_func, tf_warning_or_error);
1314 : :
1315 : 3716 : release_tree_vector (args);
1316 : 3716 : if (!awsp_func || !awsp_call || awsp_call == error_mark_node)
1317 : 0 : return error_mark_node;
1318 : :
1319 : 3716 : bool ok = false;
1320 : 3716 : tree susp_return_type = TREE_TYPE (TREE_TYPE (awsp_func));
1321 : 3716 : if (same_type_p (susp_return_type, void_type_node))
1322 : : ok = true;
1323 : 109 : else if (same_type_p (susp_return_type, boolean_type_node))
1324 : : ok = true;
1325 : 77 : else if (TREE_CODE (susp_return_type) == RECORD_TYPE
1326 : 77 : && CLASS_TYPE_P (susp_return_type)
1327 : 154 : && CLASSTYPE_TEMPLATE_INFO (susp_return_type))
1328 : : {
1329 : 76 : tree tt = CLASSTYPE_TI_TEMPLATE (susp_return_type);
1330 : 76 : if (tt == coro_handle_templ)
1331 : : ok = true;
1332 : : }
1333 : :
1334 : : if (!ok)
1335 : : {
1336 : 1 : error_at (loc, "%<await_suspend%> must return %<void%>, %<bool%> or"
1337 : : " a coroutine handle");
1338 : 1 : return error_mark_node;
1339 : : }
1340 : :
1341 : : /* Finally, the type of e.await_resume() is the co_await's type. */
1342 : 3715 : tree awrs_func = NULL_TREE;
1343 : 3715 : tree awrs_call
1344 : 3715 : = build_new_method_call (e_proxy, awrs_meth, NULL, NULL_TREE, LOOKUP_NORMAL,
1345 : : &awrs_func, tf_warning_or_error);
1346 : :
1347 : 3715 : if (!awrs_func || !awrs_call || awrs_call == error_mark_node)
1348 : 0 : return error_mark_node;
1349 : :
1350 : 3715 : if (flag_exceptions && suspend_kind == FINAL_SUSPEND_POINT)
1351 : : {
1352 : 1335 : if (coro_diagnose_throwing_fn (awrd_func))
1353 : 1 : return error_mark_node;
1354 : 1334 : if (coro_diagnose_throwing_fn (awsp_func))
1355 : 1 : return error_mark_node;
1356 : 1333 : if (coro_diagnose_throwing_fn (awrs_func))
1357 : 1 : return error_mark_node;
1358 : 1332 : if (tree dummy = cxx_maybe_build_cleanup (e_proxy, tf_none))
1359 : : {
1360 : 781 : if (CONVERT_EXPR_P (dummy))
1361 : 0 : dummy = TREE_OPERAND (dummy, 0);
1362 : 781 : dummy = TREE_OPERAND (CALL_EXPR_FN (dummy), 0);
1363 : 781 : if (coro_diagnose_throwing_fn (dummy))
1364 : 1 : return error_mark_node;
1365 : : }
1366 : : }
1367 : :
1368 : : /* We now have three call expressions, in terms of the promise, handle and
1369 : : 'e' proxies. Save them in the await expression for later expansion. */
1370 : :
1371 : 3711 : tree awaiter_calls = make_tree_vec (3);
1372 : 3711 : TREE_VEC_ELT (awaiter_calls, 0) = awrd_call; /* await_ready(). */
1373 : 3711 : TREE_VEC_ELT (awaiter_calls, 1) = awsp_call; /* await_suspend(). */
1374 : 3711 : tree te = NULL_TREE;
1375 : 3711 : if (TREE_CODE (awrs_call) == TARGET_EXPR)
1376 : : {
1377 : 19 : te = awrs_call;
1378 : 19 : awrs_call = TARGET_EXPR_INITIAL (awrs_call);
1379 : : }
1380 : 3711 : TREE_VEC_ELT (awaiter_calls, 2) = awrs_call; /* await_resume(). */
1381 : :
1382 : 3711 : if (REFERENCE_REF_P (e_proxy))
1383 : 29 : e_proxy = TREE_OPERAND (e_proxy, 0);
1384 : :
1385 : 3711 : tree awrs_type = TREE_TYPE (TREE_TYPE (awrs_func));
1386 : 7422 : tree suspend_kind_cst = build_int_cst (integer_type_node,
1387 : 3711 : (int) suspend_kind);
1388 : 3711 : tree await_expr = build5_loc (loc, CO_AWAIT_EXPR,
1389 : : awrs_type,
1390 : : a, e_proxy, o, awaiter_calls,
1391 : : suspend_kind_cst);
1392 : 3711 : TREE_SIDE_EFFECTS (await_expr) = true;
1393 : 3711 : if (te)
1394 : : {
1395 : 19 : TREE_OPERAND (te, 1) = await_expr;
1396 : 19 : TREE_SIDE_EFFECTS (te) = true;
1397 : 19 : await_expr = te;
1398 : : }
1399 : 3711 : SET_EXPR_LOCATION (await_expr, loc);
1400 : :
1401 : 3711 : if (processing_template_decl)
1402 : 20 : return build_template_co_await_expr (loc, awrs_type, orig_operand,
1403 : 20 : suspend_kind_cst);
1404 : 3691 : return convert_from_reference (await_expr);
1405 : : }
1406 : :
1407 : : /* Returns true iff EXPR or the TRAITS_CLASS, which should be a
1408 : : coroutine_traits instance, are dependent. In those cases, we can't decide
1409 : : what the types of our co_{await,yield,return} expressions are, so we defer
1410 : : expansion entirely. */
1411 : :
1412 : : static bool
1413 : 3910 : coro_dependent_p (tree expr, tree traits_class)
1414 : : {
1415 : 3910 : return type_dependent_expression_p (expr)
1416 : 3910 : || dependent_type_p (traits_class);
1417 : : }
1418 : :
1419 : : tree
1420 : 779 : finish_co_await_expr (location_t kw, tree expr)
1421 : : {
1422 : 779 : if (!expr || error_operand_p (expr))
1423 : 0 : return error_mark_node;
1424 : :
1425 : 779 : if (!coro_common_keyword_context_valid_p (current_function_decl, kw,
1426 : : "co_await"))
1427 : 9 : return error_mark_node;
1428 : :
1429 : : /* The current function has now become a coroutine, if it wasn't already. */
1430 : 770 : DECL_COROUTINE_P (current_function_decl) = 1;
1431 : :
1432 : : /* This function will appear to have no return statement, even if it
1433 : : is declared to return non-void (most likely). This is correct - we
1434 : : synthesize the return for the ramp in the compiler. So suppress any
1435 : : extraneous warnings during substitution. */
1436 : 770 : suppress_warning (current_function_decl, OPT_Wreturn_type);
1437 : :
1438 : : /* Prepare for coroutine transformations. */
1439 : 770 : if (!ensure_coro_initialized (kw))
1440 : 2 : return error_mark_node;
1441 : :
1442 : : /* Get our traits class. */
1443 : 768 : tree traits_class = coro_get_traits_class (current_function_decl, kw);
1444 : :
1445 : : /* Defer expansion when we are processing a template, unless the traits type
1446 : : and expression would not be dependent. In the case that the types are
1447 : : not dependent but we are processing a template declaration, we will do
1448 : : most of the computation but throw away the results (except for the
1449 : : await_resume type). Otherwise, if our co_await is type-dependent
1450 : : (i.e. the promise type or operand type is dependent), we can't do much,
1451 : : and just return early with a NULL_TREE type (indicating that we cannot
1452 : : compute the type yet). */
1453 : 768 : if (coro_dependent_p (expr, traits_class))
1454 : 100 : return build_template_co_await_expr (kw, NULL_TREE, expr,
1455 : 100 : integer_zero_node);
1456 : :
1457 : : /* We must be able to look up the "await_transform" method in the scope of
1458 : : the promise type, and obtain its return type. */
1459 : 668 : if (!coro_promise_type_found_p (current_function_decl, kw))
1460 : 1 : return error_mark_node;
1461 : :
1462 : : /* [expr.await] 3.2
1463 : : The incoming cast expression might be transformed by a promise
1464 : : 'await_transform()'. */
1465 : 667 : tree at_meth
1466 : 667 : = lookup_promise_method (current_function_decl,
1467 : : coro_await_transform_identifier, kw,
1468 : : /*musthave=*/false);
1469 : 667 : if (at_meth == error_mark_node)
1470 : : return error_mark_node;
1471 : :
1472 : 667 : tree a = expr;
1473 : 667 : if (at_meth)
1474 : : {
1475 : : /* try to build a = p.await_transform (e). */
1476 : 202 : vec<tree, va_gc> *args = make_tree_vector_single (expr);
1477 : 404 : a = build_new_method_call (get_coroutine_promise_proxy (
1478 : : current_function_decl),
1479 : : at_meth, &args, NULL_TREE, LOOKUP_NORMAL,
1480 : : NULL, tf_warning_or_error);
1481 : :
1482 : : /* As I read the section.
1483 : : We saw an await_transform method, so it's mandatory that we replace
1484 : : expr with p.await_transform (expr), therefore if the method call fails
1485 : : (presumably, we don't have suitable arguments) then this part of the
1486 : : process fails. */
1487 : 202 : if (a == error_mark_node)
1488 : 0 : return error_mark_node;
1489 : : }
1490 : :
1491 : : /* Now we want to build co_await a. */
1492 : 667 : return build_co_await (kw, a, CO_AWAIT_SUSPEND_POINT, expr);
1493 : : }
1494 : :
1495 : : /* Take the EXPR given and attempt to build:
1496 : : co_await p.yield_value (expr);
1497 : : per [expr.yield] para 1. */
1498 : :
1499 : : tree
1500 : 1585 : finish_co_yield_expr (location_t kw, tree expr)
1501 : : {
1502 : 1585 : if (!expr || error_operand_p (expr))
1503 : 0 : return error_mark_node;
1504 : :
1505 : : /* Check the general requirements and simple syntax errors. */
1506 : 1585 : if (!coro_common_keyword_context_valid_p (current_function_decl, kw,
1507 : : "co_yield"))
1508 : 9 : return error_mark_node;
1509 : :
1510 : : /* The current function has now become a coroutine, if it wasn't already. */
1511 : 1576 : DECL_COROUTINE_P (current_function_decl) = 1;
1512 : :
1513 : : /* This function will appear to have no return statement, even if it
1514 : : is declared to return non-void (most likely). This is correct - we
1515 : : synthesize the return for the ramp in the compiler. So suppress any
1516 : : extraneous warnings during substitution. */
1517 : 1576 : suppress_warning (current_function_decl, OPT_Wreturn_type);
1518 : :
1519 : : /* Prepare for coroutine transformations. */
1520 : 1576 : if (!ensure_coro_initialized (kw))
1521 : 4 : return error_mark_node;
1522 : :
1523 : : /* Get our traits class. */
1524 : 1572 : tree traits_class = coro_get_traits_class (current_function_decl, kw);
1525 : :
1526 : : /* Defer expansion when we are processing a template; see note in
1527 : : finish_co_await_expr. Also note that a yield is equivalent to
1528 : :
1529 : : co_await p.yield_value(EXPR)
1530 : :
1531 : : If either p or EXPR are type-dependent, then the whole expression is
1532 : : certainly type-dependent, and we can't proceed. */
1533 : 1572 : if (coro_dependent_p (expr, traits_class))
1534 : 1204 : return build2_loc (kw, CO_YIELD_EXPR, NULL_TREE, expr, NULL_TREE);
1535 : :
1536 : 368 : if (!coro_promise_type_found_p (current_function_decl, kw))
1537 : : /* We must be able to look up the "yield_value" method in the scope of
1538 : : the promise type, and obtain its return type. */
1539 : 2 : return error_mark_node;
1540 : :
1541 : : /* [expr.yield] / 1
1542 : : Let e be the operand of the yield-expression and p be an lvalue naming
1543 : : the promise object of the enclosing coroutine, then the yield-expression
1544 : : is equivalent to the expression co_await p.yield_value(e).
1545 : : build p.yield_value(e): */
1546 : 366 : vec<tree, va_gc> *args = make_tree_vector_single (expr);
1547 : 366 : tree yield_call
1548 : 366 : = coro_build_promise_expression (current_function_decl, NULL,
1549 : : coro_yield_value_identifier, kw,
1550 : : &args, /*musthave=*/true);
1551 : 366 : release_tree_vector (args);
1552 : :
1553 : : /* Now build co_await p.yield_value (e).
1554 : : Noting that for co_yield, there is no evaluation of any potential
1555 : : promise transform_await(), so we call build_co_await directly. */
1556 : :
1557 : 366 : tree op = build_co_await (kw, yield_call, CO_YIELD_SUSPEND_POINT);
1558 : 366 : if (op != error_mark_node)
1559 : : {
1560 : 363 : if (REFERENCE_REF_P (op))
1561 : 0 : op = TREE_OPERAND (op, 0);
1562 : : /* If the await expression is wrapped in a TARGET_EXPR, then transfer
1563 : : that wrapper to the CO_YIELD_EXPR, since this is just a proxy for
1564 : : its contained await. Otherwise, just build the CO_YIELD_EXPR. */
1565 : 363 : if (TREE_CODE (op) == TARGET_EXPR)
1566 : : {
1567 : 1 : tree t = TARGET_EXPR_INITIAL (op);
1568 : 1 : t = build2_loc (kw, CO_YIELD_EXPR, TREE_TYPE (t), expr, t);
1569 : 1 : TARGET_EXPR_INITIAL (op) = t;
1570 : : }
1571 : : else
1572 : 362 : op = build2_loc (kw, CO_YIELD_EXPR, TREE_TYPE (op), expr, op);
1573 : 363 : TREE_SIDE_EFFECTS (op) = 1;
1574 : 363 : op = convert_from_reference (op);
1575 : : }
1576 : :
1577 : : return op;
1578 : : }
1579 : :
1580 : : /* Check and build a co_return statement.
1581 : : First that it's valid to have a co_return keyword here.
1582 : : If it is, then check and build the p.return_{void(),value(expr)}.
1583 : : These are built against a proxy for the promise, which will be filled
1584 : : in with the actual frame version when the function is transformed. */
1585 : :
1586 : : tree
1587 : 1587 : finish_co_return_stmt (location_t kw, tree expr)
1588 : : {
1589 : 1587 : if (expr)
1590 : 1245 : STRIP_ANY_LOCATION_WRAPPER (expr);
1591 : :
1592 : 1587 : if (error_operand_p (expr))
1593 : 0 : return error_mark_node;
1594 : :
1595 : : /* If it fails the following test, the function is not permitted to be a
1596 : : coroutine, so the co_return statement is erroneous. */
1597 : 1587 : if (!coro_common_keyword_context_valid_p (current_function_decl, kw,
1598 : : "co_return"))
1599 : 7 : return error_mark_node;
1600 : :
1601 : : /* The current function has now become a coroutine, if it wasn't
1602 : : already. */
1603 : 1580 : DECL_COROUTINE_P (current_function_decl) = 1;
1604 : :
1605 : : /* This function will appear to have no return statement, even if it
1606 : : is declared to return non-void (most likely). This is correct - we
1607 : : synthesize the return for the ramp in the compiler. So suppress any
1608 : : extraneous warnings during substitution. */
1609 : 1580 : suppress_warning (current_function_decl, OPT_Wreturn_type);
1610 : :
1611 : : /* Prepare for coroutine transformations. */
1612 : 1580 : if (!ensure_coro_initialized (kw))
1613 : 10 : return error_mark_node;
1614 : :
1615 : : /* Get our traits class. */
1616 : 1570 : tree traits_class = coro_get_traits_class (current_function_decl, kw);
1617 : :
1618 : 1570 : if (processing_template_decl
1619 : 1570 : && check_for_bare_parameter_packs (expr))
1620 : 0 : return error_mark_node;
1621 : :
1622 : : /* Defer expansion when we must and are processing a template; see note in
1623 : : finish_co_await_expr. */
1624 : 1570 : if (coro_dependent_p (expr, traits_class))
1625 : : {
1626 : : /* co_return expressions are always void type, regardless of the
1627 : : expression type. */
1628 : 156 : expr = build2_loc (kw, CO_RETURN_EXPR, void_type_node,
1629 : : expr, NULL_TREE);
1630 : 156 : expr = maybe_cleanup_point_expr_void (expr);
1631 : 156 : return add_stmt (expr);
1632 : : }
1633 : :
1634 : 1414 : if (!coro_promise_type_found_p (current_function_decl, kw))
1635 : 6 : return error_mark_node;
1636 : :
1637 : : /* Suppress -Wreturn-type for co_return, we need to check indirectly
1638 : : whether the promise type has a suitable return_void/return_value. */
1639 : 1408 : suppress_warning (current_function_decl, OPT_Wreturn_type);
1640 : :
1641 : 1408 : if (!processing_template_decl && warn_sequence_point)
1642 : 3 : verify_sequence_points (expr);
1643 : :
1644 : 1408 : if (expr)
1645 : : {
1646 : : /* If we had an id-expression obfuscated by force_paren_expr, we need
1647 : : to undo it so we can try to treat it as an rvalue below. */
1648 : 1085 : expr = maybe_undo_parenthesized_ref (expr);
1649 : :
1650 : 1085 : if (error_operand_p (expr))
1651 : 0 : return error_mark_node;
1652 : : }
1653 : :
1654 : : /* If the promise object doesn't have the correct return call then
1655 : : there's a mis-match between the co_return <expr> and this. */
1656 : 323 : tree co_ret_call = error_mark_node;
1657 : 1085 : if (expr == NULL_TREE || VOID_TYPE_P (TREE_TYPE (expr)))
1658 : 334 : co_ret_call
1659 : 334 : = get_coroutine_return_void_expr (current_function_decl, kw, true);
1660 : : else
1661 : : {
1662 : : /* [class.copy.elision] / 3.
1663 : : An implicitly movable entity is a variable of automatic storage
1664 : : duration that is either a non-volatile object or an rvalue reference
1665 : : to a non-volatile object type. For such objects in the context of
1666 : : the co_return, the overload resolution should be carried out first
1667 : : treating the object as an rvalue, if that fails, then we fall back
1668 : : to regular overload resolution. */
1669 : :
1670 : 1074 : tree arg = expr;
1671 : 1074 : if (tree moved = treat_lvalue_as_rvalue_p (expr, /*return*/true))
1672 : 262 : arg = moved;
1673 : :
1674 : 1074 : releasing_vec args = make_tree_vector_single (arg);
1675 : 1074 : co_ret_call
1676 : 1074 : = coro_build_promise_expression (current_function_decl, NULL,
1677 : : coro_return_value_identifier, kw,
1678 : : &args, /*musthave=*/true);
1679 : 1074 : }
1680 : :
1681 : : /* Makes no sense for a co-routine really. */
1682 : 1408 : if (TREE_THIS_VOLATILE (current_function_decl))
1683 : 0 : warning_at (kw, 0,
1684 : : "function declared %<noreturn%> has a"
1685 : : " %<co_return%> statement");
1686 : :
1687 : 1408 : expr = build2_loc (kw, CO_RETURN_EXPR, void_type_node, expr, co_ret_call);
1688 : 1408 : expr = maybe_cleanup_point_expr_void (expr);
1689 : 1408 : return add_stmt (expr);
1690 : : }
1691 : :
1692 : : /* We need to validate the arguments to __builtin_coro_promise, since the
1693 : : second two must be constant, and the builtins machinery doesn't seem to
1694 : : deal with that properly. */
1695 : :
1696 : : tree
1697 : 2442374 : coro_validate_builtin_call (tree call, tsubst_flags_t)
1698 : : {
1699 : 2442374 : tree fn = TREE_OPERAND (CALL_EXPR_FN (call), 0);
1700 : :
1701 : 2442374 : gcc_checking_assert (DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL);
1702 : 2442374 : switch (DECL_FUNCTION_CODE (fn))
1703 : : {
1704 : : default:
1705 : : return call;
1706 : :
1707 : 8325 : case BUILT_IN_CORO_PROMISE:
1708 : 8325 : {
1709 : : /* Argument 0 is already checked by the normal built-in machinery
1710 : : Argument 1 must be a constant of size type. It probably makes
1711 : : little sense if it's not a power of 2, but that isn't specified
1712 : : formally. */
1713 : 8325 : tree arg = CALL_EXPR_ARG (call, 1);
1714 : 8325 : location_t loc = EXPR_LOCATION (arg);
1715 : :
1716 : : /* We expect alignof expressions in templates. */
1717 : 8325 : if (TREE_CODE (arg) == ALIGNOF_EXPR)
1718 : : ;
1719 : 1913 : else if (!TREE_CONSTANT (arg))
1720 : : {
1721 : 0 : error_at (loc, "the align argument to %<__builtin_coro_promise%>"
1722 : : " must be a constant");
1723 : 0 : return error_mark_node;
1724 : : }
1725 : : /* Argument 2 is the direction - to / from handle address to promise
1726 : : address. */
1727 : 8325 : arg = CALL_EXPR_ARG (call, 2);
1728 : 8325 : loc = EXPR_LOCATION (arg);
1729 : 8325 : if (!TREE_CONSTANT (arg))
1730 : : {
1731 : 0 : error_at (loc, "the direction argument to"
1732 : : " %<__builtin_coro_promise%> must be a constant");
1733 : 0 : return error_mark_node;
1734 : : }
1735 : : return call;
1736 : : break;
1737 : : }
1738 : : }
1739 : : }
1740 : :
1741 : : /* ================= Morph and Expand. =================
1742 : :
1743 : : The entry point here is morph_fn_to_coro () which is called from
1744 : : finish_function () when we have completed any template expansion.
1745 : :
1746 : : This is preceded by helper functions that implement the phases below.
1747 : :
1748 : : The process proceeds in four phases.
1749 : :
1750 : : A Initial framing.
1751 : : The user's function body is wrapped in the initial and final suspend
1752 : : points and we begin building the coroutine frame.
1753 : : We build empty decls for the actor and destroyer functions at this
1754 : : time too.
1755 : : When exceptions are enabled, the user's function body will also be
1756 : : wrapped in a try-catch block with the catch invoking the promise
1757 : : class 'unhandled_exception' method.
1758 : :
1759 : : B Analysis.
1760 : : The user's function body is analyzed to determine the suspend points,
1761 : : if any, and to capture local variables that might persist across such
1762 : : suspensions. In most cases, it is not necessary to capture compiler
1763 : : temporaries, since the tree-lowering nests the suspensions correctly.
1764 : : However, in the case of a captured reference, there is a lifetime
1765 : : extension to the end of the full expression - which can mean across a
1766 : : suspend point in which case it must be promoted to a frame variable.
1767 : :
1768 : : At the conclusion of analysis, we have a conservative frame layout and
1769 : : maps of the local variables to their frame entry points.
1770 : :
1771 : : C Build the ramp function.
1772 : : Carry out the allocation for the coroutine frame (NOTE; the actual size
1773 : : computation is deferred until late in the middle end to allow for future
1774 : : optimizations that will be allowed to elide unused frame entries).
1775 : : We build the return object.
1776 : :
1777 : : D Build and expand the actor and destroyer function bodies.
1778 : : The destroyer is a trivial shim that sets a bit to indicate that the
1779 : : destroy dispatcher should be used and then calls into the actor.
1780 : :
1781 : : The actor function is the implementation of the user's state machine.
1782 : : The current suspend point is noted in an index.
1783 : : Each suspend point is encoded as a pair of internal functions, one in
1784 : : the relevant dispatcher, and one representing the suspend point.
1785 : :
1786 : : During this process, the user's local variables and the proxies for the
1787 : : self-handle and the promise class instance are re-written to their
1788 : : coroutine frame equivalents.
1789 : :
1790 : : The complete bodies for the ramp, actor and destroy function are passed
1791 : : back to finish_function for folding and gimplification. */
1792 : :
1793 : : /* Helper to build a coroutine state frame access expression
1794 : : CORO_FP is a frame pointer
1795 : : MEMBER_ID is an identifier for a frame field
1796 : : PRESERVE_REF is true, the expression returned will have REFERENCE_TYPE if
1797 : : the MEMBER does.
1798 : : COMPLAIN is passed to the underlying functions. */
1799 : :
1800 : : static tree
1801 : 29299 : coro_build_frame_access_expr (tree coro_ref, tree member_id, bool preserve_ref,
1802 : : tsubst_flags_t complain)
1803 : : {
1804 : 29299 : gcc_checking_assert (INDIRECT_REF_P (coro_ref));
1805 : 29299 : tree fr_type = TREE_TYPE (coro_ref);
1806 : 29299 : tree mb = lookup_member (fr_type, member_id, /*protect=*/1, /*want_type=*/0,
1807 : : complain);
1808 : 29299 : if (!mb || mb == error_mark_node)
1809 : 0 : return error_mark_node;
1810 : 29299 : tree expr
1811 : 29299 : = build_class_member_access_expr (coro_ref, mb, NULL_TREE,
1812 : : preserve_ref, complain);
1813 : 29299 : return expr;
1814 : : }
1815 : :
1816 : : /* Helpers to build EXPR_STMT and void-cast EXPR_STMT, common ops. */
1817 : :
1818 : : static tree
1819 : 2676 : coro_build_expr_stmt (tree expr, location_t loc)
1820 : : {
1821 : 2676 : return maybe_cleanup_point_expr_void (build_stmt (loc, EXPR_STMT, expr));
1822 : : }
1823 : :
1824 : : static tree
1825 : 2676 : coro_build_cvt_void_expr_stmt (tree expr, location_t loc)
1826 : : {
1827 : 2676 : tree t = build1 (CONVERT_EXPR, void_type_node, expr);
1828 : 2676 : return coro_build_expr_stmt (t, loc);
1829 : : }
1830 : :
1831 : : /* Helpers to build an artificial var, with location LOC, NAME and TYPE, in
1832 : : CTX, and with initializer INIT. */
1833 : :
1834 : : static tree
1835 : 20213 : coro_build_artificial_var (location_t loc, tree name, tree type, tree ctx,
1836 : : tree init)
1837 : : {
1838 : 20213 : tree res = build_lang_decl (VAR_DECL, name, type);
1839 : 20213 : DECL_SOURCE_LOCATION (res) = loc;
1840 : 20213 : DECL_CONTEXT (res) = ctx;
1841 : 20213 : DECL_ARTIFICIAL (res) = true;
1842 : 20213 : DECL_INITIAL (res) = init;
1843 : 20213 : return res;
1844 : : }
1845 : :
1846 : : /* As above, except allowing the name to be a string. */
1847 : :
1848 : : static tree
1849 : 4017 : coro_build_artificial_var (location_t loc, const char *name, tree type,
1850 : : tree ctx, tree init)
1851 : : {
1852 : 4017 : return coro_build_artificial_var (loc, get_identifier (name),
1853 : 4017 : type, ctx, init);
1854 : : }
1855 : :
1856 : : /* As for coro_build_artificial_var, except that we push this decl into
1857 : : the current binding scope and add the decl_expr. */
1858 : :
1859 : : static tree
1860 : 2670 : coro_build_and_push_artificial_var (location_t loc, const char *name,
1861 : : tree type, tree ctx, tree init)
1862 : : {
1863 : 2670 : tree v = coro_build_artificial_var (loc, name, type, ctx, init);
1864 : 2670 : v = pushdecl (v);
1865 : 2670 : add_decl_expr (v);
1866 : 2670 : return v;
1867 : : }
1868 : :
1869 : : /* Build a var NAME of TYPE in CTX and with INIT; add a DECL_VALUE_EXPR that
1870 : : refers to BASE.FIELD. */
1871 : :
1872 : : static tree
1873 : 8044 : coro_build_artificial_var_with_dve (location_t loc, tree name, tree type,
1874 : : tree ctx, tree init, tree base,
1875 : : tree field = NULL_TREE)
1876 : : {
1877 : 8044 : tree v = coro_build_artificial_var (loc, name, type, ctx, init);
1878 : 8044 : if (field == NULL_TREE)
1879 : 8044 : field = name;
1880 : 8044 : tree dve = coro_build_frame_access_expr (base, field, true,
1881 : : tf_warning_or_error);
1882 : 8044 : SET_DECL_VALUE_EXPR (v, dve);
1883 : 8044 : DECL_HAS_VALUE_EXPR_P (v) = true;
1884 : 8044 : return v;
1885 : : }
1886 : :
1887 : : /* As for coro_build_artificial_var_with_dve, but push into the current binding
1888 : : scope and add the decl_expr. */
1889 : :
1890 : : static tree
1891 : 8044 : coro_build_and_push_artificial_var_with_dve (location_t loc, tree name,
1892 : : tree type, tree ctx, tree init,
1893 : : tree base, tree field = NULL_TREE)
1894 : : {
1895 : 8044 : tree v = coro_build_artificial_var_with_dve (loc, name, type, ctx, init,
1896 : : base, field);
1897 : 8044 : v = pushdecl (v);
1898 : 8044 : add_decl_expr (v);
1899 : 8044 : return v;
1900 : : }
1901 : :
1902 : : /* 2. Create a named label in the specified context. */
1903 : :
1904 : : static tree
1905 : 16736 : create_named_label_with_ctx (location_t loc, const char *name, tree ctx)
1906 : : {
1907 : 16736 : tree lab_id = get_identifier (name);
1908 : 16736 : tree lab = define_label (loc, lab_id);
1909 : 16736 : DECL_CONTEXT (lab) = ctx;
1910 : 16736 : DECL_ARTIFICIAL (lab) = true;
1911 : 16736 : TREE_USED (lab) = true;
1912 : 16736 : return lab;
1913 : : }
1914 : :
1915 : : struct proxy_replace
1916 : : {
1917 : : tree from, to;
1918 : : };
1919 : :
1920 : : static tree
1921 : 10174 : replace_proxy (tree *here, int *do_subtree, void *d)
1922 : : {
1923 : 10174 : proxy_replace *data = (proxy_replace *) d;
1924 : :
1925 : 10174 : if (*here == data->from)
1926 : : {
1927 : 208 : *here = data->to;
1928 : 208 : *do_subtree = 0;
1929 : : }
1930 : : else
1931 : 9966 : *do_subtree = 1;
1932 : 10174 : return NULL_TREE;
1933 : : }
1934 : :
1935 : : /* Support for expansion of co_await statements. */
1936 : :
1937 : : struct coro_aw_data
1938 : : {
1939 : : tree actor_fn; /* Decl for context. */
1940 : : tree coro_fp; /* Frame pointer var. */
1941 : : tree resume_idx; /* This is the index var in the frame. */
1942 : : tree i_a_r_c; /* initial suspend await_resume() was called if true. */
1943 : : tree self_h; /* This is a handle to the current coro (frame var). */
1944 : : tree cleanup; /* This is where to go once we complete local destroy. */
1945 : : tree cororet; /* This is where to go if we suspend. */
1946 : : tree corocont; /* This is where to go if we continue. */
1947 : : tree dispatch; /* This is where we go if we restart the dispatch. */
1948 : : tree conthand; /* This is the handle for a continuation. */
1949 : : unsigned index; /* This is our current resume index. */
1950 : : };
1951 : :
1952 : : /* Lightweight search for the first await expression in tree-walk order.
1953 : : returns:
1954 : : The first await expression found in STMT.
1955 : : NULL_TREE if there are none.
1956 : : So can be used to determine if the statement needs to be processed for
1957 : : awaits. */
1958 : :
1959 : : static tree
1960 : 337919 : co_await_find_in_subtree (tree *stmt, int *, void *d)
1961 : : {
1962 : 337919 : tree **p = (tree **) d;
1963 : 337919 : if (TREE_CODE (*stmt) == CO_AWAIT_EXPR)
1964 : : {
1965 : 3671 : *p = stmt;
1966 : 3671 : return *stmt;
1967 : : }
1968 : : return NULL_TREE;
1969 : : }
1970 : :
1971 : : /* Starting with a statement:
1972 : :
1973 : : stmt => some tree containing one or more await expressions.
1974 : :
1975 : : We replace the statement with:
1976 : : <STATEMENT_LIST> {
1977 : : initialize awaitable
1978 : : if (!ready)
1979 : : {
1980 : : suspension context.
1981 : : }
1982 : : resume:
1983 : : revised statement with one await expression rewritten to its
1984 : : await_resume() return value.
1985 : : }
1986 : :
1987 : : We then recurse into the initializer and the revised statement
1988 : : repeating this replacement until there are no more await expressions
1989 : : in either. */
1990 : :
1991 : : static tree *
1992 : 3671 : expand_one_await_expression (tree *expr, tree *await_expr, void *d)
1993 : : {
1994 : 3671 : coro_aw_data *data = (coro_aw_data *) d;
1995 : :
1996 : 3671 : tree saved_statement = *expr;
1997 : 3671 : tree saved_co_await = *await_expr;
1998 : :
1999 : 3671 : tree actor = data->actor_fn;
2000 : 3671 : location_t loc = EXPR_LOCATION (*expr);
2001 : 3671 : tree var = TREE_OPERAND (saved_co_await, 1); /* frame slot. */
2002 : 3671 : tree init_expr = TREE_OPERAND (saved_co_await, 2); /* initializer. */
2003 : 3671 : tree awaiter_calls = TREE_OPERAND (saved_co_await, 3);
2004 : :
2005 : 3671 : tree source = TREE_OPERAND (saved_co_await, 4);
2006 : 3671 : bool is_final = (source
2007 : 3671 : && TREE_INT_CST_LOW (source) == (int) FINAL_SUSPEND_POINT);
2008 : :
2009 : : /* Build labels for the destinations of the control flow when we are resuming
2010 : : or destroying. */
2011 : 3671 : int resume_point = data->index;
2012 : 3671 : char *buf = xasprintf ("destroy.%d", resume_point);
2013 : 3671 : tree destroy_label = create_named_label_with_ctx (loc, buf, actor);
2014 : 3671 : free (buf);
2015 : 3671 : buf = xasprintf ("resume.%d", resume_point);
2016 : 3671 : tree resume_label = create_named_label_with_ctx (loc, buf, actor);
2017 : 3671 : free (buf);
2018 : :
2019 : : /* This will contain our expanded expression and replace the original
2020 : : expression. */
2021 : 3671 : tree stmt_list = push_stmt_list ();
2022 : 3671 : tree *await_init = NULL;
2023 : :
2024 : 3671 : bool needs_dtor = TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TREE_TYPE (var));
2025 : 3671 : if (!init_expr)
2026 : : needs_dtor = false; /* No need, the var's lifetime is managed elsewhere. */
2027 : : else
2028 : : {
2029 : 0 : finish_expr_stmt (init_expr);
2030 : : /* We have an initializer, which might itself contain await exprs. */
2031 : 0 : await_init = tsi_stmt_ptr (tsi_last (stmt_list));
2032 : : }
2033 : :
2034 : : /* Use the await_ready() call to test if we need to suspend. */
2035 : 3671 : tree ready_cond = TREE_VEC_ELT (awaiter_calls, 0); /* await_ready(). */
2036 : :
2037 : : /* We will resume (or continue) at the following index. */
2038 : 3671 : tree resume_idx = build_int_cst (short_unsigned_type_node, data->index);
2039 : 3671 : tree r = cp_build_init_expr (data->resume_idx, resume_idx);
2040 : 3671 : finish_expr_stmt (r);
2041 : :
2042 : : /* Convert to bool, if necessary. */
2043 : 3671 : if (TREE_CODE (TREE_TYPE (ready_cond)) != BOOLEAN_TYPE)
2044 : 2 : ready_cond = cp_convert (boolean_type_node, ready_cond,
2045 : : tf_warning_or_error);
2046 : 3671 : tree susp_if = begin_if_stmt ();
2047 : : /* Be aggressive in folding here, since there are a significant number of
2048 : : cases where the ready condition is constant. */
2049 : 3671 : ready_cond = invert_truthvalue_loc (loc, ready_cond);
2050 : 3671 : finish_if_stmt_cond (ready_cond, susp_if);
2051 : :
2052 : : /* Find out what we have to do with the awaiter's suspend method.
2053 : : [expr.await]
2054 : : (5.1) If the result of await-ready is false, the coroutine is considered
2055 : : suspended. Then:
2056 : : (5.1.1) If the type of await-suspend is std::coroutine_handle<Z>,
2057 : : await-suspend.resume() is evaluated.
2058 : : (5.1.2) if the type of await-suspend is bool, await-suspend is evaluated,
2059 : : and the coroutine is resumed if the result is false.
2060 : : (5.1.3) Otherwise, await-suspend is evaluated. */
2061 : :
2062 : 3671 : tree suspend = TREE_VEC_ELT (awaiter_calls, 1); /* await_suspend(). */
2063 : 3671 : tree susp_type = TREE_TYPE (suspend);
2064 : :
2065 : 3671 : bool is_cont = false;
2066 : : /* NOTE: final suspend can't resume; the "resume" label in that case
2067 : : corresponds to implicit destruction. */
2068 : 3671 : if (VOID_TYPE_P (susp_type))
2069 : : /* Void return - just proceed to suspend. */
2070 : 3567 : finish_expr_stmt (suspend);
2071 : 104 : else if (TREE_CODE (susp_type) == BOOLEAN_TYPE)
2072 : : {
2073 : : /* Boolean return, "continue" if the call returns false. */
2074 : 30 : tree restart_if = begin_if_stmt ();
2075 : 30 : suspend = invert_truthvalue_loc (loc, suspend);
2076 : 30 : finish_if_stmt_cond (suspend, restart_if);
2077 : : /* Resume - so restart the dispatcher, since we do not know if this
2078 : : coroutine was already resumed from within await_suspend. We must
2079 : : exit this scope without cleanups. */
2080 : 30 : r = build_call_expr_internal_loc (loc, IFN_CO_SUSPN, void_type_node, 1,
2081 : : build_address (data->dispatch));
2082 : : /* This will eventually expand to 'goto coro.restart.dispatch'. */
2083 : 30 : finish_expr_stmt (r);
2084 : 30 : finish_then_clause (restart_if);
2085 : 30 : finish_if_stmt (restart_if);
2086 : : }
2087 : : else
2088 : : {
2089 : : /* Handle return, save it to the continuation. */
2090 : 74 : r = suspend;
2091 : 74 : if (!same_type_ignoring_top_level_qualifiers_p (susp_type,
2092 : : void_coro_handle_type))
2093 : 11 : r = build1_loc (loc, VIEW_CONVERT_EXPR, void_coro_handle_type, r);
2094 : 74 : r = cp_build_init_expr (loc, data->conthand, r);
2095 : 74 : finish_expr_stmt (r);
2096 : 74 : is_cont = true;
2097 : : }
2098 : :
2099 : 3671 : tree d_l = build_address (destroy_label);
2100 : 3671 : tree r_l = build_address (resume_label);
2101 : 3671 : tree susp = build_address (data->cororet);
2102 : 3671 : tree cont = build_address (data->corocont);
2103 : 6014 : tree final_susp = build_int_cst (integer_type_node, is_final ? 1 : 0);
2104 : :
2105 : 3671 : resume_idx = build_int_cst (integer_type_node, data->index);
2106 : :
2107 : 3671 : tree sw = begin_switch_stmt ();
2108 : :
2109 : 3671 : r = build_call_expr_internal_loc (loc, IFN_CO_YIELD, integer_type_node, 5,
2110 : : resume_idx, final_susp, r_l, d_l,
2111 : : data->coro_fp);
2112 : 3671 : finish_switch_cond (r, sw);
2113 : 3671 : finish_case_label (loc, integer_zero_node, NULL_TREE); /* case 0: */
2114 : : /* Implement the suspend, a scope exit without clean ups. */
2115 : 7268 : r = build_call_expr_internal_loc (loc, IFN_CO_SUSPN, void_type_node, 1,
2116 : : is_cont ? cont : susp);
2117 : 3671 : finish_expr_stmt (r); /* This will eventually expand to 'goto return'. */
2118 : 3671 : finish_case_label (loc, integer_one_node, NULL_TREE); /* case 1: */
2119 : 3671 : add_stmt (build_stmt (loc, GOTO_EXPR, resume_label)); /* goto resume; */
2120 : 3671 : finish_case_label (loc, NULL_TREE, NULL_TREE); /* default:; */
2121 : 3671 : add_stmt (build_stmt (loc, GOTO_EXPR, destroy_label)); /* goto destroy; */
2122 : :
2123 : 3671 : finish_switch_stmt (sw);
2124 : 3671 : add_stmt (build_stmt (loc, LABEL_EXPR, destroy_label));
2125 : 3671 : if (needs_dtor)
2126 : 0 : finish_expr_stmt (build_cleanup (var));
2127 : 3671 : add_stmt (build_stmt (loc, GOTO_EXPR, data->cleanup));
2128 : :
2129 : 3671 : finish_then_clause (susp_if);
2130 : 3671 : finish_if_stmt (susp_if);
2131 : :
2132 : : /* Resume point. */
2133 : 3671 : add_stmt (build_stmt (loc, LABEL_EXPR, resume_label));
2134 : :
2135 : : /* This will produce the value (if one is provided) from the co_await
2136 : : expression. */
2137 : 3671 : tree resume_call = TREE_VEC_ELT (awaiter_calls, 2); /* await_resume(). */
2138 : 3671 : if (REFERENCE_REF_P (resume_call))
2139 : : /* Sink to await_resume call_expr. */
2140 : 41 : resume_call = TREE_OPERAND (resume_call, 0);
2141 : :
2142 : 3671 : *await_expr = resume_call; /* Replace the co_await expr with its result. */
2143 : 3671 : append_to_statement_list_force (saved_statement, &stmt_list);
2144 : : /* Get a pointer to the revised statement. */
2145 : 3671 : tree *revised = tsi_stmt_ptr (tsi_last (stmt_list));
2146 : 3671 : if (needs_dtor)
2147 : 0 : finish_expr_stmt (build_cleanup (var));
2148 : 3671 : data->index += 2;
2149 : :
2150 : : /* Replace the original expression with the expansion. */
2151 : 3671 : *expr = pop_stmt_list (stmt_list);
2152 : :
2153 : : /* Now, if the awaitable had an initializer, expand any awaits that might
2154 : : be embedded in it. */
2155 : 3671 : tree *aw_expr_ptr;
2156 : 3671 : if (await_init &&
2157 : 0 : cp_walk_tree (await_init, co_await_find_in_subtree, &aw_expr_ptr, NULL))
2158 : 0 : expand_one_await_expression (await_init, aw_expr_ptr, d);
2159 : :
2160 : : /* Expand any more await expressions in the original statement. */
2161 : 3671 : if (cp_walk_tree (revised, co_await_find_in_subtree, &aw_expr_ptr, NULL))
2162 : 16 : expand_one_await_expression (revised, aw_expr_ptr, d);
2163 : :
2164 : 3671 : return NULL;
2165 : : }
2166 : :
2167 : : /* Check to see if a statement contains at least one await expression, if
2168 : : so, then process that. */
2169 : :
2170 : : static tree
2171 : 42290 : process_one_statement (tree *stmt, void *d)
2172 : : {
2173 : 42290 : tree *aw_expr_ptr;
2174 : 42290 : if (cp_walk_tree (stmt, co_await_find_in_subtree, &aw_expr_ptr, NULL))
2175 : 3655 : expand_one_await_expression (stmt, aw_expr_ptr, d);
2176 : 42290 : return NULL_TREE;
2177 : : }
2178 : :
2179 : : static tree
2180 : 283761 : await_statement_expander (tree *stmt, int *do_subtree, void *d)
2181 : : {
2182 : 283761 : tree res = NULL_TREE;
2183 : :
2184 : : /* Process a statement at a time. */
2185 : 283761 : if (STATEMENT_CLASS_P (*stmt)
2186 : 213087 : || TREE_CODE (*stmt) == BIND_EXPR
2187 : 206526 : || TREE_CODE (*stmt) == CLEANUP_POINT_EXPR)
2188 : : return NULL_TREE; /* Just process the sub-trees. */
2189 : 174865 : else if (TREE_CODE (*stmt) == STATEMENT_LIST)
2190 : : {
2191 : 116235 : for (tree &s : tsi_range (*stmt))
2192 : : {
2193 : 100349 : res = cp_walk_tree (&s, await_statement_expander,
2194 : : d, NULL);
2195 : 100349 : if (res)
2196 : 283761 : return res;
2197 : : }
2198 : 15886 : *do_subtree = 0; /* Done subtrees. */
2199 : : }
2200 : 158979 : else if (EXPR_P (*stmt))
2201 : : {
2202 : 42290 : process_one_statement (stmt, d);
2203 : 42290 : *do_subtree = 0; /* Done subtrees. */
2204 : : }
2205 : :
2206 : : /* Continue statement walk, where required. */
2207 : : return res;
2208 : : }
2209 : :
2210 : : struct await_xform_data
2211 : : {
2212 : : tree actor_fn; /* Decl for context. */
2213 : : tree actor_frame;
2214 : : hash_map<tree, suspend_point_info> *suspend_points;
2215 : : };
2216 : :
2217 : : /* When we built the await expressions, we didn't know the coro frame
2218 : : layout, therefore no idea where to find the promise or where to put
2219 : : the awaitables. Now we know these things, fill them in. */
2220 : :
2221 : : static tree
2222 : 3671 : transform_await_expr (tree await_expr, await_xform_data *xform)
2223 : : {
2224 : 3671 : suspend_point_info *si = xform->suspend_points->get (await_expr);
2225 : 3671 : location_t loc = EXPR_LOCATION (await_expr);
2226 : 3671 : if (!si)
2227 : : {
2228 : 0 : error_at (loc, "no suspend point info for %qD", await_expr);
2229 : 0 : return error_mark_node;
2230 : : }
2231 : :
2232 : : /* So, on entry, we have:
2233 : : in : CO_AWAIT_EXPR (a, e_proxy, o, awr_call_vector, mode)
2234 : : We no longer need a [it had diagnostic value, maybe?]
2235 : : We need to replace the e_proxy in the awr_call. */
2236 : :
2237 : : /* If we have a frame var for the awaitable, get a reference to it. */
2238 : 3671 : proxy_replace data;
2239 : 3671 : if (si->await_field_id)
2240 : : {
2241 : 0 : tree as
2242 : 0 : = coro_build_frame_access_expr (xform->actor_frame, si->await_field_id,
2243 : : true, tf_warning_or_error);
2244 : : /* Replace references to the instance proxy with the frame entry now
2245 : : computed. */
2246 : 0 : data.from = TREE_OPERAND (await_expr, 1);
2247 : 0 : data.to = as;
2248 : 0 : cp_walk_tree (&await_expr, replace_proxy, &data, NULL);
2249 : :
2250 : : /* .. and replace. */
2251 : 0 : TREE_OPERAND (await_expr, 1) = as;
2252 : : }
2253 : :
2254 : 3671 : return await_expr;
2255 : : }
2256 : :
2257 : : /* A wrapper for the transform_await_expr function so that it can be a
2258 : : callback from cp_walk_tree. */
2259 : :
2260 : : static tree
2261 : 285017 : transform_await_wrapper (tree *stmt, int *do_subtree, void *d)
2262 : : {
2263 : : /* Set actor function as new DECL_CONTEXT of label_decl. */
2264 : 285017 : struct await_xform_data *xform = (struct await_xform_data *) d;
2265 : 285017 : if (TREE_CODE (*stmt) == LABEL_DECL
2266 : 285017 : && DECL_CONTEXT (*stmt) != xform->actor_fn)
2267 : 1392 : DECL_CONTEXT (*stmt) = xform->actor_fn;
2268 : :
2269 : : /* We should have already lowered co_yields to their co_await. */
2270 : 285017 : gcc_checking_assert (TREE_CODE (*stmt) != CO_YIELD_EXPR);
2271 : 285017 : if (TREE_CODE (*stmt) != CO_AWAIT_EXPR)
2272 : : return NULL_TREE;
2273 : :
2274 : 3671 : tree await_expr = *stmt;
2275 : 3671 : *stmt = transform_await_expr (await_expr, xform);
2276 : 3671 : if (*stmt == error_mark_node)
2277 : 0 : *do_subtree = 0;
2278 : : return NULL_TREE;
2279 : : }
2280 : :
2281 : : /* For figuring out what local variable usage we have. */
2282 : : struct local_vars_transform
2283 : : {
2284 : : tree context;
2285 : : tree actor_frame;
2286 : : tree coro_frame_type;
2287 : : location_t loc;
2288 : : hash_map<tree, local_var_info> *local_var_uses;
2289 : : };
2290 : :
2291 : : static tree
2292 : 440919 : transform_local_var_uses (tree *stmt, int *do_subtree, void *d)
2293 : : {
2294 : 440919 : local_vars_transform *lvd = (local_vars_transform *) d;
2295 : :
2296 : : /* For each var in this bind expr (that has a frame id, which means it was
2297 : : accessed), build a frame reference and add it as the DECL_VALUE_EXPR. */
2298 : :
2299 : 440919 : if (TREE_CODE (*stmt) == BIND_EXPR)
2300 : : {
2301 : 6563 : tree lvar;
2302 : 21645 : for (lvar = BIND_EXPR_VARS (*stmt); lvar != NULL;
2303 : 15082 : lvar = DECL_CHAIN (lvar))
2304 : : {
2305 : 15082 : bool existed;
2306 : 15082 : local_var_info &local_var
2307 : 15082 : = lvd->local_var_uses->get_or_insert (lvar, &existed);
2308 : 15082 : gcc_checking_assert (existed);
2309 : :
2310 : : /* Re-write the variable's context to be in the actor func. */
2311 : 15082 : DECL_CONTEXT (lvar) = lvd->context;
2312 : :
2313 : : /* For capture proxies, this could include the decl value expr. */
2314 : 15082 : if (local_var.is_lambda_capture || local_var.has_value_expr_p)
2315 : 143 : continue; /* No frame entry for this. */
2316 : :
2317 : : /* TODO: implement selective generation of fields when vars are
2318 : : known not-used. */
2319 : 14964 : if (local_var.field_id == NULL_TREE)
2320 : 25 : continue; /* Wasn't used. */
2321 : 14939 : tree fld_idx
2322 : 14939 : = coro_build_frame_access_expr (lvd->actor_frame,
2323 : : local_var.field_id, true,
2324 : : tf_warning_or_error);
2325 : 14939 : local_var.field_idx = fld_idx;
2326 : 14939 : SET_DECL_VALUE_EXPR (lvar, fld_idx);
2327 : 14939 : DECL_HAS_VALUE_EXPR_P (lvar) = true;
2328 : : }
2329 : 6563 : cp_walk_tree (&BIND_EXPR_BODY (*stmt), transform_local_var_uses, d, NULL);
2330 : 6563 : *do_subtree = 0; /* We've done the body already. */
2331 : 6563 : return NULL_TREE;
2332 : : }
2333 : : return NULL_TREE;
2334 : : }
2335 : :
2336 : : /* A helper to build the frame DTOR.
2337 : : [dcl.fct.def.coroutine] / 12
2338 : : The deallocation function’s name is looked up in the scope of the promise
2339 : : type. If this lookup fails, the deallocation function’s name is looked up
2340 : : in the global scope. If deallocation function lookup finds both a usual
2341 : : deallocation function with only a pointer parameter and a usual
2342 : : deallocation function with both a pointer parameter and a size parameter,
2343 : : then the selected deallocation function shall be the one with two
2344 : : parameters. Otherwise, the selected deallocation function shall be the
2345 : : function with one parameter. If no usual deallocation function is found
2346 : : the program is ill-formed. The selected deallocation function shall be
2347 : : called with the address of the block of storage to be reclaimed as its
2348 : : first argument. If a deallocation function with a parameter of type
2349 : : std::size_t is used, the size of the block is passed as the corresponding
2350 : : argument. */
2351 : :
2352 : : static tree
2353 : : build_coroutine_frame_delete_expr (tree, tree, tree, location_t);
2354 : :
2355 : : /* The actor transform. */
2356 : :
2357 : : static void
2358 : 1338 : build_actor_fn (location_t loc, tree coro_frame_type, tree actor, tree fnbody,
2359 : : tree orig, hash_map<tree, local_var_info> *local_var_uses,
2360 : : hash_map<tree, suspend_point_info> *suspend_points,
2361 : : vec<tree> *param_dtor_list,
2362 : : tree resume_idx_var, unsigned body_count, tree frame_size,
2363 : : bool inline_p)
2364 : : {
2365 : 1338 : verify_stmt_tree (fnbody);
2366 : : /* Some things we inherit from the original function. */
2367 : 1338 : tree promise_type = get_coroutine_promise_type (orig);
2368 : 1338 : tree promise_proxy = get_coroutine_promise_proxy (orig);
2369 : :
2370 : : /* One param, the coro frame pointer. */
2371 : 1338 : tree actor_fp = DECL_ARGUMENTS (actor);
2372 : :
2373 : 1338 : bool spf = start_preparsed_function (actor, NULL_TREE, SF_PRE_PARSED);
2374 : 1338 : gcc_checking_assert (spf);
2375 : 1338 : gcc_checking_assert (cfun && current_function_decl && TREE_STATIC (actor));
2376 : 1338 : tree stmt = begin_function_body ();
2377 : :
2378 : 1338 : tree actor_bind = build3 (BIND_EXPR, void_type_node, NULL, NULL, NULL);
2379 : 1338 : tree top_block = make_node (BLOCK);
2380 : 1338 : BIND_EXPR_BLOCK (actor_bind) = top_block;
2381 : :
2382 : 1338 : tree continuation = coro_build_artificial_var (loc, coro_actor_continue_id,
2383 : : void_coro_handle_type, actor,
2384 : : NULL_TREE);
2385 : :
2386 : 1338 : BIND_EXPR_VARS (actor_bind) = continuation;
2387 : 1338 : BLOCK_VARS (top_block) = BIND_EXPR_VARS (actor_bind) ;
2388 : :
2389 : : /* Link in the block associated with the outer scope of the re-written
2390 : : function body. */
2391 : 1338 : tree first = expr_first (fnbody);
2392 : 1338 : gcc_checking_assert (first && TREE_CODE (first) == BIND_EXPR);
2393 : 1338 : tree block = BIND_EXPR_BLOCK (first);
2394 : 1338 : gcc_checking_assert (BLOCK_SUPERCONTEXT (block) == NULL_TREE);
2395 : 1338 : gcc_checking_assert (BLOCK_CHAIN (block) == NULL_TREE);
2396 : 1338 : BLOCK_SUPERCONTEXT (block) = top_block;
2397 : 1338 : BLOCK_SUBBLOCKS (top_block) = block;
2398 : :
2399 : 1338 : add_stmt (actor_bind);
2400 : 1338 : tree actor_body = push_stmt_list ();
2401 : :
2402 : : /* The entry point for the actor code from the ramp. */
2403 : 1338 : tree actor_begin_label
2404 : 1338 : = create_named_label_with_ctx (loc, "actor.begin", actor);
2405 : 1338 : tree actor_frame = build1_loc (loc, INDIRECT_REF, coro_frame_type, actor_fp);
2406 : :
2407 : : /* Declare the continuation handle. */
2408 : 1338 : add_decl_expr (continuation);
2409 : :
2410 : : /* Re-write local vars, similarly. */
2411 : 1338 : local_vars_transform xform_vars_data
2412 : 1338 : = {actor, actor_frame, coro_frame_type, loc, local_var_uses};
2413 : 1338 : cp_walk_tree (&fnbody, transform_local_var_uses, &xform_vars_data, NULL);
2414 : 1338 : tree rat = coro_build_frame_access_expr (actor_frame, coro_resume_index_id,
2415 : : false, tf_warning_or_error);
2416 : 1338 : tree ret_label
2417 : 1338 : = create_named_label_with_ctx (loc, "actor.suspend.ret", actor);
2418 : :
2419 : 1338 : tree continue_label
2420 : 1338 : = create_named_label_with_ctx (loc, "actor.continue.ret", actor);
2421 : :
2422 : : /* Build the dispatcher; for each await expression there is an odd entry
2423 : : corresponding to the destruction action and an even entry for the resume
2424 : : one:
2425 : : if (resume index is odd)
2426 : : {
2427 : : switch (resume index)
2428 : : case 1:
2429 : : goto cleanup.
2430 : : case ... odd suspension point number
2431 : : .CO_ACTOR (... odd suspension point number)
2432 : : break;
2433 : : default:
2434 : : break;
2435 : : }
2436 : : else
2437 : : {
2438 : : coro.restart.dispatch:
2439 : : case 0:
2440 : : goto start.
2441 : : case ... even suspension point number
2442 : : .CO_ACTOR (... even suspension point number)
2443 : : break;
2444 : : default:
2445 : : break;
2446 : : }
2447 : : we should not get here unless something is broken badly.
2448 : : __builtin_trap ();
2449 : : */
2450 : 1338 : tree lsb_if = begin_if_stmt ();
2451 : 1338 : tree chkb0 = build2 (BIT_AND_EXPR, short_unsigned_type_node, rat,
2452 : 1338 : build_int_cst (short_unsigned_type_node, 1));
2453 : 1338 : chkb0 = build2 (NE_EXPR, short_unsigned_type_node, chkb0,
2454 : 1338 : build_int_cst (short_unsigned_type_node, 0));
2455 : 1338 : finish_if_stmt_cond (chkb0, lsb_if);
2456 : :
2457 : 1338 : tree destroy_dispatcher = begin_switch_stmt ();
2458 : 1338 : finish_switch_cond (rat, destroy_dispatcher);
2459 : :
2460 : : /* The destroy point numbered #1 is special, in that it is reached from a
2461 : : coroutine that is suspended after re-throwing from unhandled_exception().
2462 : : This label just invokes the cleanup of promise, param copies and the
2463 : : frame itself. */
2464 : 1338 : tree del_promise_label
2465 : 1338 : = create_named_label_with_ctx (loc, "coro.delete.promise", actor);
2466 : 1338 : finish_case_label (loc, build_int_cst (short_unsigned_type_node, 1),
2467 : : NULL_TREE);
2468 : 1338 : add_stmt (build_stmt (loc, GOTO_EXPR, del_promise_label));
2469 : :
2470 : 1338 : short unsigned lab_num = 3;
2471 : 5009 : for (unsigned destr_pt = 0; destr_pt < body_count; destr_pt++)
2472 : : {
2473 : 3671 : tree l_num = build_int_cst (short_unsigned_type_node, lab_num);
2474 : 3671 : finish_case_label (loc, l_num, NULL_TREE);
2475 : 3671 : tree c = build_call_expr_internal_loc (loc, IFN_CO_ACTOR, void_type_node,
2476 : : 1, l_num);
2477 : 3671 : finish_expr_stmt (c);
2478 : 3671 : finish_break_stmt ();
2479 : 3671 : lab_num += 2;
2480 : : }
2481 : 1338 : finish_case_label (loc, NULL_TREE, NULL_TREE);
2482 : 1338 : finish_break_stmt ();
2483 : :
2484 : : /* Finish the destroy dispatcher. */
2485 : 1338 : finish_switch_stmt (destroy_dispatcher);
2486 : :
2487 : 1338 : finish_then_clause (lsb_if);
2488 : 1338 : begin_else_clause (lsb_if);
2489 : :
2490 : : /* For the case of a boolean await_resume () that returns 'true' we should
2491 : : restart the dispatch, since we cannot know if additional resumes were
2492 : : executed from within the await_suspend function. */
2493 : 1338 : tree restart_dispatch_label
2494 : 1338 : = create_named_label_with_ctx (loc, "coro.restart.dispatch", actor);
2495 : 1338 : add_stmt (build_stmt (loc, LABEL_EXPR, restart_dispatch_label));
2496 : :
2497 : 1338 : tree dispatcher = begin_switch_stmt ();
2498 : 1338 : finish_switch_cond (rat, dispatcher);
2499 : 1338 : finish_case_label (loc, build_int_cst (short_unsigned_type_node, 0),
2500 : : NULL_TREE);
2501 : 1338 : add_stmt (build_stmt (loc, GOTO_EXPR, actor_begin_label));
2502 : :
2503 : 1338 : lab_num = 2;
2504 : : /* The final resume should be made to hit the default (trap, UB) entry
2505 : : although it will be unreachable via the normal entry point, since that
2506 : : is set to NULL on reaching final suspend. */
2507 : 5009 : for (unsigned resu_pt = 0; resu_pt < body_count; resu_pt++)
2508 : : {
2509 : 3671 : tree l_num = build_int_cst (short_unsigned_type_node, lab_num);
2510 : 3671 : finish_case_label (loc, l_num, NULL_TREE);
2511 : 3671 : tree c = build_call_expr_internal_loc (loc, IFN_CO_ACTOR, void_type_node,
2512 : : 1, l_num);
2513 : 3671 : finish_expr_stmt (c);
2514 : 3671 : finish_break_stmt ();
2515 : 3671 : lab_num += 2;
2516 : : }
2517 : 1338 : finish_case_label (loc, NULL_TREE, NULL_TREE);
2518 : 1338 : finish_break_stmt ();
2519 : :
2520 : : /* Finish the resume dispatcher. */
2521 : 1338 : finish_switch_stmt (dispatcher);
2522 : 1338 : finish_else_clause (lsb_if);
2523 : :
2524 : 1338 : finish_if_stmt (lsb_if);
2525 : :
2526 : : /* If we reach here then we've hit UB. */
2527 : 1338 : tree t = build_call_expr_loc (loc, builtin_decl_explicit (BUILT_IN_TRAP), 0);
2528 : 1338 : finish_expr_stmt (t);
2529 : :
2530 : : /* Now we start building the rewritten function body. */
2531 : 1338 : add_stmt (build_stmt (loc, LABEL_EXPR, actor_begin_label));
2532 : :
2533 : : /* actor's coroutine 'self handle'. */
2534 : 1338 : tree ash = coro_build_frame_access_expr (actor_frame, coro_self_handle_id,
2535 : : false, tf_warning_or_error);
2536 : : /* So construct the self-handle from the frame address. */
2537 : 1338 : tree hfa_m = get_coroutine_from_address (orig);
2538 : : /* Should have been set earlier by coro_promise_type_found_p. */
2539 : 1338 : gcc_assert (hfa_m);
2540 : :
2541 : 1338 : tree r = build1 (CONVERT_EXPR, build_pointer_type (void_type_node), actor_fp);
2542 : 1338 : vec<tree, va_gc> *args = make_tree_vector_single (r);
2543 : 1338 : tree hfa = build_new_method_call (ash, hfa_m, &args, NULL_TREE, LOOKUP_NORMAL,
2544 : : NULL, tf_warning_or_error);
2545 : 1338 : r = cp_build_init_expr (ash, hfa);
2546 : 1338 : r = coro_build_cvt_void_expr_stmt (r, loc);
2547 : 1338 : add_stmt (r);
2548 : 1338 : release_tree_vector (args);
2549 : :
2550 : : /* Now we know the real promise, and enough about the frame layout to
2551 : : decide where to put things. */
2552 : :
2553 : 1338 : await_xform_data xform = {actor, actor_frame, suspend_points};
2554 : :
2555 : : /* Transform the await expressions in the function body. Only do each
2556 : : await tree once! */
2557 : 1338 : hash_set<tree> pset;
2558 : 1338 : cp_walk_tree (&fnbody, transform_await_wrapper, &xform, &pset);
2559 : :
2560 : : /* Add in our function body with the co_returns rewritten to final form. */
2561 : 1338 : add_stmt (fnbody);
2562 : :
2563 : : /* now do the tail of the function. */
2564 : 1338 : r = build_stmt (loc, LABEL_EXPR, del_promise_label);
2565 : 1338 : add_stmt (r);
2566 : :
2567 : : /* Destructors for the things we built explicitly. */
2568 : 1338 : if (tree c = cxx_maybe_build_cleanup (promise_proxy, tf_warning_or_error))
2569 : 983 : add_stmt (c);
2570 : :
2571 : 1338 : tree del_frame_label
2572 : 1338 : = create_named_label_with_ctx (loc, "coro.delete.frame", actor);
2573 : 1338 : r = build_stmt (loc, LABEL_EXPR, del_frame_label);
2574 : 1338 : add_stmt (r);
2575 : :
2576 : : /* Here deallocate the frame (if we allocated it), which we will have at
2577 : : present. */
2578 : 1338 : tree fnf2_x
2579 : 1338 : = coro_build_frame_access_expr (actor_frame, coro_frame_needs_free_id,
2580 : : false, tf_warning_or_error);
2581 : :
2582 : 1338 : tree need_free_if = begin_if_stmt ();
2583 : 1338 : fnf2_x = build1 (CONVERT_EXPR, integer_type_node, fnf2_x);
2584 : 1338 : tree cmp = build2 (NE_EXPR, integer_type_node, fnf2_x, integer_zero_node);
2585 : 1338 : finish_if_stmt_cond (cmp, need_free_if);
2586 : 2757 : while (!param_dtor_list->is_empty ())
2587 : : {
2588 : 81 : tree parm_id = param_dtor_list->pop ();
2589 : 81 : tree a = coro_build_frame_access_expr (actor_frame, parm_id, false,
2590 : : tf_warning_or_error);
2591 : 81 : if (tree dtor = cxx_maybe_build_cleanup (a, tf_warning_or_error))
2592 : 81 : add_stmt (dtor);
2593 : : }
2594 : :
2595 : : /* Build the frame DTOR. */
2596 : 1338 : tree del_coro_fr
2597 : 1338 : = build_coroutine_frame_delete_expr (actor_fp, frame_size,
2598 : : promise_type, loc);
2599 : 1338 : finish_expr_stmt (del_coro_fr);
2600 : 1338 : finish_then_clause (need_free_if);
2601 : 1338 : tree scope = IF_SCOPE (need_free_if);
2602 : 1338 : IF_SCOPE (need_free_if) = NULL;
2603 : 1338 : r = do_poplevel (scope);
2604 : 1338 : add_stmt (r);
2605 : :
2606 : : /* done. */
2607 : 1338 : r = build_stmt (loc, RETURN_EXPR, NULL);
2608 : 1338 : suppress_warning (r); /* We don't want a warning about this. */
2609 : 1338 : r = maybe_cleanup_point_expr_void (r);
2610 : 1338 : add_stmt (r);
2611 : :
2612 : : /* This is the suspend return point. */
2613 : 1338 : r = build_stmt (loc, LABEL_EXPR, ret_label);
2614 : 1338 : add_stmt (r);
2615 : :
2616 : 1338 : r = build_stmt (loc, RETURN_EXPR, NULL);
2617 : 1338 : suppress_warning (r); /* We don't want a warning about this. */
2618 : 1338 : r = maybe_cleanup_point_expr_void (r);
2619 : 1338 : add_stmt (r);
2620 : :
2621 : : /* This is the 'continuation' return point. For such a case we have a coro
2622 : : handle (from the await_suspend() call) and we want handle.resume() to
2623 : : execute as a tailcall allowing arbitrary chaining of coroutines. */
2624 : 1338 : r = build_stmt (loc, LABEL_EXPR, continue_label);
2625 : 1338 : add_stmt (r);
2626 : :
2627 : : /* Should have been set earlier by the coro_initialized code. */
2628 : 1338 : gcc_assert (void_coro_handle_address);
2629 : :
2630 : : /* We want to force a tail-call even for O0/1, so this expands the resume
2631 : : call into its underlying implementation. */
2632 : 1338 : tree addr = build_new_method_call (continuation, void_coro_handle_address,
2633 : : NULL, NULL_TREE, LOOKUP_NORMAL, NULL,
2634 : : tf_warning_or_error);
2635 : 1338 : tree resume = build_call_expr_loc
2636 : 1338 : (loc, builtin_decl_explicit (BUILT_IN_CORO_RESUME), 1, addr);
2637 : :
2638 : : /* In order to support an arbitrary number of coroutine continuations,
2639 : : we must tail call them. However, some targets do not support indirect
2640 : : tail calls to arbitrary callees. See PR94359. */
2641 : 1338 : CALL_EXPR_TAILCALL (resume) = true;
2642 : 1338 : resume = coro_build_cvt_void_expr_stmt (resume, loc);
2643 : 1338 : add_stmt (resume);
2644 : :
2645 : 1338 : r = build_stmt (loc, RETURN_EXPR, NULL);
2646 : 1338 : gcc_checking_assert (maybe_cleanup_point_expr_void (r) == r);
2647 : 1338 : add_stmt (r);
2648 : :
2649 : : /* We've now rewritten the tree and added the initial and final
2650 : : co_awaits. Now pass over the tree and expand the co_awaits. */
2651 : :
2652 : 1338 : coro_aw_data data = {actor, actor_fp, resume_idx_var, NULL_TREE,
2653 : : ash, del_promise_label, ret_label,
2654 : 1338 : continue_label, restart_dispatch_label, continuation, 2};
2655 : 1338 : cp_walk_tree (&actor_body, await_statement_expander, &data, NULL);
2656 : :
2657 : 1338 : BIND_EXPR_BODY (actor_bind) = pop_stmt_list (actor_body);
2658 : 1338 : TREE_SIDE_EFFECTS (actor_bind) = true;
2659 : :
2660 : 1338 : cfun->coroutine_component = 1;
2661 : 1338 : finish_function_body (stmt);
2662 : 1338 : finish_function (inline_p);
2663 : 1338 : }
2664 : :
2665 : : /* The prototype 'destroy' function :
2666 : : frame->__Coro_resume_index |= 1;
2667 : : actor (frame); */
2668 : :
2669 : : static void
2670 : 1338 : build_destroy_fn (location_t loc, tree coro_frame_type, tree destroy,
2671 : : tree actor, bool inline_p)
2672 : : {
2673 : : /* One param, the coro frame pointer. */
2674 : 1338 : tree destr_fp = DECL_ARGUMENTS (destroy);
2675 : 1338 : gcc_checking_assert (POINTER_TYPE_P (TREE_TYPE (destr_fp))
2676 : : && same_type_p (coro_frame_type,
2677 : : TREE_TYPE (TREE_TYPE (destr_fp))));
2678 : :
2679 : 1338 : bool spf = start_preparsed_function (destroy, NULL_TREE, SF_PRE_PARSED);
2680 : 1338 : gcc_checking_assert (spf);
2681 : 1338 : tree dstr_stmt = begin_function_body ();
2682 : :
2683 : 1338 : tree destr_frame
2684 : 1338 : = cp_build_indirect_ref (loc, destr_fp, RO_UNARY_STAR,
2685 : : tf_warning_or_error);
2686 : :
2687 : 1338 : tree rat = coro_build_frame_access_expr (destr_frame, coro_resume_index_id,
2688 : : false, tf_warning_or_error);
2689 : :
2690 : : /* _resume_at |= 1 */
2691 : 1338 : tree dstr_idx
2692 : 1338 : = build2_loc (loc, BIT_IOR_EXPR, short_unsigned_type_node, rat,
2693 : 1338 : build_int_cst (short_unsigned_type_node, 1));
2694 : 1338 : tree r = cp_build_modify_expr (loc, rat, NOP_EXPR, dstr_idx,
2695 : : tf_warning_or_error);
2696 : 1338 : finish_expr_stmt (r);
2697 : :
2698 : : /* So .. call the actor .. */
2699 : 1338 : finish_expr_stmt (build_call_expr_loc (loc, actor, 1, destr_fp));
2700 : :
2701 : : /* done. */
2702 : 1338 : finish_return_stmt (NULL_TREE);
2703 : :
2704 : 1338 : gcc_checking_assert (cfun && current_function_decl);
2705 : 1338 : cfun->coroutine_component = 1;
2706 : 1338 : finish_function_body (dstr_stmt);
2707 : 1338 : finish_function (inline_p);
2708 : 1338 : }
2709 : :
2710 : : /* Helper that returns an identifier for an appended extension to the
2711 : : current un-mangled function name. */
2712 : :
2713 : : static tree
2714 : 1369 : get_fn_local_identifier (tree orig, const char *append)
2715 : : {
2716 : : /* Figure out the bits we need to generate names for the outlined things
2717 : : For consistency, this needs to behave the same way as
2718 : : ASM_FORMAT_PRIVATE_NAME does. */
2719 : 1369 : tree nm = DECL_NAME (orig);
2720 : 1369 : const char *sep, *pfx = "";
2721 : : #ifndef NO_DOT_IN_LABEL
2722 : 1369 : sep = ".";
2723 : : #else
2724 : : #ifndef NO_DOLLAR_IN_LABEL
2725 : : sep = "$";
2726 : : #else
2727 : : sep = "_";
2728 : : pfx = "__";
2729 : : #endif
2730 : : #endif
2731 : :
2732 : 1369 : char *an;
2733 : 1369 : if (DECL_ASSEMBLER_NAME (orig))
2734 : 1369 : an = ACONCAT ((IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (orig)), sep, append,
2735 : : (char *) 0));
2736 : 0 : else if (DECL_USE_TEMPLATE (orig) && DECL_TEMPLATE_INFO (orig)
2737 : 0 : && DECL_TI_ARGS (orig))
2738 : : {
2739 : 0 : tree tpl_args = DECL_TI_ARGS (orig);
2740 : 0 : an = ACONCAT ((pfx, IDENTIFIER_POINTER (nm), (char *) 0));
2741 : 0 : for (int i = 0; i < TREE_VEC_LENGTH (tpl_args); ++i)
2742 : : {
2743 : 0 : tree typ = DECL_NAME (TYPE_NAME (TREE_VEC_ELT (tpl_args, i)));
2744 : 0 : an = ACONCAT ((an, sep, IDENTIFIER_POINTER (typ), (char *) 0));
2745 : : }
2746 : 0 : an = ACONCAT ((an, sep, append, (char *) 0));
2747 : : }
2748 : : else
2749 : 0 : an = ACONCAT ((pfx, IDENTIFIER_POINTER (nm), sep, append, (char *) 0));
2750 : :
2751 : 1369 : return get_identifier (an);
2752 : : }
2753 : :
2754 : : /* Build an initial or final await initialized from the promise
2755 : : initial_suspend or final_suspend expression. */
2756 : :
2757 : : static tree
2758 : 2696 : build_init_or_final_await (location_t loc, bool is_final)
2759 : : {
2760 : 2696 : tree suspend_alt = is_final ? coro_final_suspend_identifier
2761 : : : coro_initial_suspend_identifier;
2762 : :
2763 : 2696 : tree setup_call
2764 : 2696 : = coro_build_promise_expression (current_function_decl, NULL, suspend_alt,
2765 : : loc, NULL, /*musthave=*/true);
2766 : :
2767 : : /* Check for noexcept on the final_suspend call. */
2768 : 2682 : if (flag_exceptions && is_final && setup_call != error_mark_node
2769 : 4036 : && coro_diagnose_throwing_final_aw_expr (setup_call))
2770 : 1 : return error_mark_node;
2771 : :
2772 : : /* So build the co_await for this */
2773 : : /* For initial/final suspends the call is "a" per [expr.await] 3.2. */
2774 : 4043 : return build_co_await (loc, setup_call, (is_final ? FINAL_SUSPEND_POINT
2775 : 2695 : : INITIAL_SUSPEND_POINT));
2776 : : }
2777 : :
2778 : : /* Callback to record the essential data for each await point found in the
2779 : : function. */
2780 : :
2781 : : static bool
2782 : 3691 : register_await_info (tree await_expr, tree aw_type, tree aw_nam,
2783 : : hash_map<tree, suspend_point_info> *suspend_points)
2784 : : {
2785 : 3691 : bool seen;
2786 : 3691 : suspend_point_info &s
2787 : 3691 : = suspend_points->get_or_insert (await_expr, &seen);
2788 : 3691 : if (seen)
2789 : : {
2790 : 0 : warning_at (EXPR_LOCATION (await_expr), 0, "duplicate info for %qE",
2791 : : await_expr);
2792 : 0 : return false;
2793 : : }
2794 : 3691 : s.awaitable_type = aw_type;
2795 : 3691 : s.await_field_id = aw_nam;
2796 : 3691 : return true;
2797 : : }
2798 : :
2799 : : /* If this is an await expression, then count it (both uniquely within the
2800 : : function and locally within a single statement). */
2801 : :
2802 : : static tree
2803 : 184814 : register_awaits (tree *stmt, int *, void *d)
2804 : : {
2805 : 184814 : tree aw_expr = *stmt;
2806 : :
2807 : : /* We should have already lowered co_yields to their co_await. */
2808 : 184814 : gcc_checking_assert (TREE_CODE (aw_expr) != CO_YIELD_EXPR);
2809 : :
2810 : 184814 : if (TREE_CODE (aw_expr) != CO_AWAIT_EXPR)
2811 : : return NULL_TREE;
2812 : :
2813 : : /* Count how many awaits the current expression contains. */
2814 : 3691 : susp_frame_data *data = (susp_frame_data *) d;
2815 : 3691 : data->saw_awaits++;
2816 : : /* Each await suspend context is unique, this is a function-wide value. */
2817 : 3691 : data->await_number++;
2818 : :
2819 : : /* Awaitables should either be user-locals or promoted to coroutine frame
2820 : : entries at this point, and their initializers should have been broken
2821 : : out. */
2822 : 3691 : tree aw = TREE_OPERAND (aw_expr, 1);
2823 : 3691 : gcc_checking_assert (!TREE_OPERAND (aw_expr, 2));
2824 : :
2825 : 3691 : tree aw_field_type = TREE_TYPE (aw);
2826 : 3691 : tree aw_field_nam = NULL_TREE;
2827 : 3691 : register_await_info (aw_expr, aw_field_type, aw_field_nam, data->suspend_points);
2828 : :
2829 : : /* Rewrite target expressions on the await_suspend () to remove extraneous
2830 : : cleanups for the awaitables, which are now promoted to frame vars and
2831 : : managed via that. */
2832 : 3691 : tree v = TREE_OPERAND (aw_expr, 3);
2833 : 3691 : tree o = TREE_VEC_ELT (v, 1);
2834 : 3691 : if (TREE_CODE (o) == TARGET_EXPR)
2835 : 76 : TREE_VEC_ELT (v, 1) = get_target_expr (TARGET_EXPR_INITIAL (o));
2836 : : return NULL_TREE;
2837 : : }
2838 : :
2839 : : /* There are cases where any await expression is relevant. */
2840 : : static tree
2841 : 392735 : find_any_await (tree *stmt, int *dosub, void *d)
2842 : : {
2843 : 392735 : if (TREE_CODE (*stmt) == CO_AWAIT_EXPR)
2844 : : {
2845 : 3756 : *dosub = 0; /* We don't need to consider this any further. */
2846 : 3756 : tree **p = (tree **) d;
2847 : 3756 : *p = stmt;
2848 : 3756 : return *stmt;
2849 : : }
2850 : : return NULL_TREE;
2851 : : }
2852 : :
2853 : : static bool
2854 : 64889 : tmp_target_expr_p (tree t)
2855 : : {
2856 : 64889 : if (TREE_CODE (t) != TARGET_EXPR)
2857 : : return false;
2858 : 4423 : tree v = TARGET_EXPR_SLOT (t);
2859 : 4423 : if (!DECL_ARTIFICIAL (v))
2860 : : return false;
2861 : 4423 : if (DECL_NAME (v))
2862 : 181 : return false;
2863 : : return true;
2864 : : }
2865 : :
2866 : : /* Structure to record sub-expressions that need to be handled by the
2867 : : statement flattener. */
2868 : :
2869 : : struct coro_interesting_subtree
2870 : : {
2871 : : tree* entry;
2872 : : hash_set<tree> *temps_used;
2873 : : };
2874 : :
2875 : : /* tree-walk callback that returns the first encountered sub-expression of
2876 : : a kind that needs to be handled specifically by the statement flattener. */
2877 : :
2878 : : static tree
2879 : 72206 : find_interesting_subtree (tree *expr_p, int *dosub, void *d)
2880 : : {
2881 : 72206 : tree expr = *expr_p;
2882 : 72206 : coro_interesting_subtree *p = (coro_interesting_subtree *)d;
2883 : 72206 : if (TREE_CODE (expr) == CO_AWAIT_EXPR)
2884 : : {
2885 : 7317 : *dosub = 0; /* We don't need to consider this any further. */
2886 : 7317 : if (TREE_OPERAND (expr, 2))
2887 : : {
2888 : 3610 : p->entry = expr_p;
2889 : 3610 : return expr;
2890 : : }
2891 : : }
2892 : 64889 : else if (tmp_target_expr_p (expr)
2893 : 4242 : && !TARGET_EXPR_ELIDING_P (expr)
2894 : 65165 : && !p->temps_used->contains (expr))
2895 : : {
2896 : 259 : p->entry = expr_p;
2897 : 259 : return expr;
2898 : : }
2899 : :
2900 : : return NULL_TREE;
2901 : : }
2902 : :
2903 : : /* Node for a doubly-linked list of promoted variables and their
2904 : : initializers. When the initializer is a conditional expression
2905 : : the 'then' and 'else' clauses are represented by a linked list
2906 : : attached to then_cl and else_cl respectively. */
2907 : :
2908 : : struct var_nest_node
2909 : : {
2910 : : var_nest_node () = default;
2911 : 7540 : var_nest_node (tree v, tree i, var_nest_node *p, var_nest_node *n)
2912 : 7540 : : var(v), init(i), prev(p), next(n), then_cl (NULL), else_cl (NULL)
2913 : : {
2914 : 7540 : if (p)
2915 : 20 : p->next = this;
2916 : 20 : if (n)
2917 : 3890 : n->prev = this;
2918 : : }
2919 : : tree var;
2920 : : tree init;
2921 : : var_nest_node *prev;
2922 : : var_nest_node *next;
2923 : : var_nest_node *then_cl;
2924 : : var_nest_node *else_cl;
2925 : : };
2926 : :
2927 : : /* This is called for single statements from the co-await statement walker.
2928 : : It checks to see if the statement contains any initializers for awaitables
2929 : : and if any of these capture items by reference. */
2930 : :
2931 : : static void
2932 : 11409 : flatten_await_stmt (var_nest_node *n, hash_set<tree> *promoted,
2933 : : hash_set<tree> *temps_used, tree *replace_in)
2934 : : {
2935 : 11517 : bool init_expr = false;
2936 : 11517 : switch (TREE_CODE (n->init))
2937 : : {
2938 : : default: break;
2939 : : /* Compound expressions must be flattened specifically. */
2940 : 5 : case COMPOUND_EXPR:
2941 : 5 : {
2942 : 5 : tree first = TREE_OPERAND (n->init, 0);
2943 : 5 : n->init = TREE_OPERAND (n->init, 1);
2944 : 5 : var_nest_node *ins
2945 : 5 : = new var_nest_node(NULL_TREE, first, n->prev, n);
2946 : : /* The compiler (but not the user) can generate temporaries with
2947 : : uses in the second arm of a compound expr. */
2948 : 5 : flatten_await_stmt (ins, promoted, temps_used, &n->init);
2949 : 5 : flatten_await_stmt (n, promoted, temps_used, NULL);
2950 : : /* The two arms have been processed separately. */
2951 : 11414 : return;
2952 : : }
2953 : 4582 : break;
2954 : : /* Handle conditional expressions. */
2955 : 4582 : case INIT_EXPR:
2956 : 4582 : init_expr = true;
2957 : : /* FALLTHROUGH */
2958 : 4988 : case MODIFY_EXPR:
2959 : 4988 : {
2960 : 4988 : tree old_expr = TREE_OPERAND (n->init, 1);
2961 : 4988 : if (TREE_CODE (old_expr) == COMPOUND_EXPR)
2962 : : {
2963 : 103 : tree first = TREE_OPERAND (old_expr, 0);
2964 : 103 : TREE_OPERAND (n->init, 1) = TREE_OPERAND (old_expr, 1);
2965 : 103 : var_nest_node *ins
2966 : 103 : = new var_nest_node(NULL_TREE, first, n->prev, n);
2967 : 103 : flatten_await_stmt (ins, promoted, temps_used,
2968 : : &TREE_OPERAND (n->init, 1));
2969 : 103 : flatten_await_stmt (n, promoted, temps_used, NULL);
2970 : 103 : return;
2971 : : }
2972 : 4885 : if (TREE_CODE (old_expr) != COND_EXPR)
2973 : : break;
2974 : : /* Reconstruct x = t ? y : z;
2975 : : as (void) t ? x = y : x = z; */
2976 : 16 : tree var = TREE_OPERAND (n->init, 0);
2977 : 16 : tree var_type = TREE_TYPE (var);
2978 : 16 : tree cond = COND_EXPR_COND (old_expr);
2979 : : /* We are allowed a void type throw in one or both of the cond
2980 : : expr arms. */
2981 : 16 : tree then_cl = COND_EXPR_THEN (old_expr);
2982 : 16 : if (!VOID_TYPE_P (TREE_TYPE (then_cl)))
2983 : : {
2984 : 16 : gcc_checking_assert (TREE_CODE (then_cl) != STATEMENT_LIST);
2985 : 16 : if (init_expr)
2986 : 16 : then_cl = cp_build_init_expr (var, then_cl);
2987 : : else
2988 : 0 : then_cl = build2 (MODIFY_EXPR, var_type, var, then_cl);
2989 : : }
2990 : 16 : tree else_cl = COND_EXPR_ELSE (old_expr);
2991 : 16 : if (!VOID_TYPE_P (TREE_TYPE (else_cl)))
2992 : : {
2993 : 16 : gcc_checking_assert (TREE_CODE (else_cl) != STATEMENT_LIST);
2994 : 16 : if (init_expr)
2995 : 16 : else_cl = cp_build_init_expr (var, else_cl);
2996 : : else
2997 : 0 : else_cl = build2 (MODIFY_EXPR, var_type, var, else_cl);
2998 : : }
2999 : 16 : n->init = build3 (COND_EXPR, var_type, cond, then_cl, else_cl);
3000 : : }
3001 : : /* FALLTHROUGH */
3002 : 17 : case COND_EXPR:
3003 : 17 : {
3004 : 17 : tree *found;
3005 : 17 : tree cond = COND_EXPR_COND (n->init);
3006 : : /* If the condition contains an await expression, then we need to
3007 : : set that first and use a separate var. */
3008 : 17 : if (cp_walk_tree (&cond, find_any_await, &found, NULL))
3009 : : {
3010 : 17 : tree cond_type = TREE_TYPE (cond);
3011 : 17 : tree cond_var = build_lang_decl (VAR_DECL, NULL_TREE, cond_type);
3012 : 17 : DECL_ARTIFICIAL (cond_var) = true;
3013 : 17 : layout_decl (cond_var, 0);
3014 : 17 : gcc_checking_assert (!TYPE_NEEDS_CONSTRUCTING (cond_type));
3015 : 17 : cond = cp_build_init_expr (cond_var, cond);
3016 : 17 : var_nest_node *ins
3017 : 17 : = new var_nest_node (cond_var, cond, n->prev, n);
3018 : 17 : COND_EXPR_COND (n->init) = cond_var;
3019 : 17 : flatten_await_stmt (ins, promoted, temps_used, NULL);
3020 : : }
3021 : :
3022 : 17 : n->then_cl
3023 : 17 : = new var_nest_node (n->var, COND_EXPR_THEN (n->init), NULL, NULL);
3024 : 17 : n->else_cl
3025 : 17 : = new var_nest_node (n->var, COND_EXPR_ELSE (n->init), NULL, NULL);
3026 : 17 : flatten_await_stmt (n->then_cl, promoted, temps_used, NULL);
3027 : : /* Point to the start of the flattened code. */
3028 : 51 : while (n->then_cl->prev)
3029 : 17 : n->then_cl = n->then_cl->prev;
3030 : 17 : flatten_await_stmt (n->else_cl, promoted, temps_used, NULL);
3031 : 34 : while (n->else_cl->prev)
3032 : 0 : n->else_cl = n->else_cl->prev;
3033 : 17 : return;
3034 : : }
3035 : 11392 : break;
3036 : : }
3037 : 11392 : coro_interesting_subtree v = { NULL, temps_used };
3038 : 11392 : tree t = cp_walk_tree (&n->init, find_interesting_subtree, (void *)&v, NULL);
3039 : 11392 : if (!t)
3040 : : return;
3041 : 3869 : switch (TREE_CODE (t))
3042 : : {
3043 : 0 : default: break;
3044 : 3610 : case CO_AWAIT_EXPR:
3045 : 3610 : {
3046 : : /* Await expressions with initializers have a compiler-temporary
3047 : : as the awaitable. 'promote' this. */
3048 : 3610 : tree var = TREE_OPERAND (t, 1);
3049 : 3610 : bool already_present = promoted->add (var);
3050 : 3610 : gcc_checking_assert (!already_present);
3051 : 3610 : tree init = TREE_OPERAND (t, 2);
3052 : 3610 : switch (TREE_CODE (init))
3053 : : {
3054 : : default: break;
3055 : 3610 : case INIT_EXPR:
3056 : 3610 : case MODIFY_EXPR:
3057 : 3610 : {
3058 : 3610 : tree inner = TREE_OPERAND (init, 1);
3059 : : /* We can have non-lvalue-expressions here, but when we see
3060 : : a target expression, mark it as already used. */
3061 : 3610 : if (TREE_CODE (inner) == TARGET_EXPR)
3062 : : {
3063 : 3610 : temps_used->add (inner);
3064 : 3610 : gcc_checking_assert
3065 : : (TREE_CODE (TARGET_EXPR_INITIAL (inner)) != COND_EXPR);
3066 : : }
3067 : : }
3068 : 3610 : break;
3069 : 0 : case CALL_EXPR:
3070 : : /* If this is a call and not a CTOR, then we didn't expect it. */
3071 : 0 : gcc_checking_assert
3072 : : (DECL_CONSTRUCTOR_P (TREE_OPERAND (CALL_EXPR_FN (init), 0)));
3073 : : break;
3074 : : }
3075 : 3610 : var_nest_node *ins = new var_nest_node (var, init, n->prev, n);
3076 : 3610 : TREE_OPERAND (t, 2) = NULL_TREE;
3077 : 3610 : flatten_await_stmt (ins, promoted, temps_used, NULL);
3078 : 3610 : flatten_await_stmt (n, promoted, temps_used, NULL);
3079 : 3610 : return;
3080 : : }
3081 : 259 : break;
3082 : 259 : case TARGET_EXPR:
3083 : 259 : {
3084 : : /* We have a temporary; promote it, but allow for the idiom in code
3085 : : generated by the compiler like
3086 : : a = (target_expr produces temp, op uses temp). */
3087 : 259 : tree init = t;
3088 : 259 : temps_used->add (init);
3089 : 259 : tree var_type = TREE_TYPE (init);
3090 : 259 : char *buf = xasprintf ("T%03u", (unsigned) temps_used->elements ());
3091 : 259 : tree var = build_lang_decl (VAR_DECL, get_identifier (buf), var_type);
3092 : 259 : DECL_ARTIFICIAL (var) = true;
3093 : 259 : free (buf);
3094 : 259 : bool already_present = promoted->add (var);
3095 : 259 : gcc_checking_assert (!already_present);
3096 : 259 : tree inner = TARGET_EXPR_INITIAL (init);
3097 : 259 : gcc_checking_assert (TREE_CODE (inner) != COND_EXPR);
3098 : 259 : init = cp_build_modify_expr (input_location, var, INIT_EXPR, init,
3099 : : tf_warning_or_error);
3100 : : /* Simplify for the case that we have an init containing the temp
3101 : : alone. */
3102 : 259 : if (t == n->init && n->var == NULL_TREE)
3103 : : {
3104 : 104 : n->var = var;
3105 : 104 : proxy_replace pr = {TARGET_EXPR_SLOT (t), var};
3106 : 104 : cp_walk_tree (&init, replace_proxy, &pr, NULL);
3107 : 104 : n->init = init;
3108 : 104 : if (replace_in)
3109 : 100 : cp_walk_tree (replace_in, replace_proxy, &pr, NULL);
3110 : 104 : flatten_await_stmt (n, promoted, temps_used, NULL);
3111 : 104 : }
3112 : : else
3113 : : {
3114 : 155 : var_nest_node *ins
3115 : 155 : = new var_nest_node (var, init, n->prev, n);
3116 : : /* We have to replace the target expr... */
3117 : 155 : *v.entry = var;
3118 : : /* ... and any uses of its var. */
3119 : 155 : proxy_replace pr = {TARGET_EXPR_SLOT (t), var};
3120 : 155 : cp_walk_tree (&n->init, replace_proxy, &pr, NULL);
3121 : : /* Compiler-generated temporaries can also have uses in
3122 : : following arms of compound expressions, which will be listed
3123 : : in 'replace_in' if present. */
3124 : 155 : if (replace_in)
3125 : 1 : cp_walk_tree (replace_in, replace_proxy, &pr, NULL);
3126 : 155 : flatten_await_stmt (ins, promoted, temps_used, NULL);
3127 : 155 : flatten_await_stmt (n, promoted, temps_used, NULL);
3128 : : }
3129 : 259 : return;
3130 : : }
3131 : 0 : break;
3132 : : }
3133 : : }
3134 : :
3135 : : /* Helper for 'process_conditional' that handles recursion into nested
3136 : : conditionals. */
3137 : :
3138 : : static void
3139 : 34 : handle_nested_conditionals (var_nest_node *n, vec<tree>& list,
3140 : : hash_map<tree, tree>& map)
3141 : : {
3142 : 51 : do
3143 : : {
3144 : 51 : if (n->var && DECL_NAME (n->var))
3145 : : {
3146 : 17 : list.safe_push (n->var);
3147 : 17 : if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TREE_TYPE (n->var)))
3148 : : {
3149 : 0 : bool existed;
3150 : 0 : tree& flag = map.get_or_insert (n->var, &existed);
3151 : 0 : if (!existed)
3152 : : {
3153 : : /* We didn't see this var before and it needs a DTOR, so
3154 : : build a guard variable for it. */
3155 : 0 : char *nam
3156 : 0 : = xasprintf ("%s_guard",
3157 : 0 : IDENTIFIER_POINTER (DECL_NAME (n->var)));
3158 : 0 : flag = build_lang_decl (VAR_DECL, get_identifier (nam),
3159 : : boolean_type_node);
3160 : 0 : free (nam);
3161 : 0 : DECL_ARTIFICIAL (flag) = true;
3162 : : }
3163 : :
3164 : : /* The initializer for this variable is replaced by a compound
3165 : : expression that performs the init and then records that the
3166 : : variable is live (and the DTOR should be run at the scope
3167 : : exit. */
3168 : 0 : tree set_flag = cp_build_init_expr (flag, boolean_true_node);
3169 : 0 : n->init
3170 : 0 : = build2 (COMPOUND_EXPR, boolean_type_node, n->init, set_flag);
3171 : : }
3172 : : }
3173 : 51 : if (TREE_CODE (n->init) == COND_EXPR)
3174 : : {
3175 : 0 : tree new_then = push_stmt_list ();
3176 : 0 : handle_nested_conditionals (n->then_cl, list, map);
3177 : 0 : new_then = pop_stmt_list (new_then);
3178 : 0 : tree new_else = push_stmt_list ();
3179 : 0 : handle_nested_conditionals (n->else_cl, list, map);
3180 : 0 : new_else = pop_stmt_list (new_else);
3181 : 0 : tree new_if
3182 : 0 : = build4 (IF_STMT, void_type_node, COND_EXPR_COND (n->init),
3183 : : new_then, new_else, NULL_TREE);
3184 : 0 : add_stmt (new_if);
3185 : : }
3186 : : else
3187 : 51 : finish_expr_stmt (n->init);
3188 : 51 : n = n->next;
3189 : 51 : } while (n);
3190 : 34 : }
3191 : :
3192 : : /* helper for 'maybe_promote_temps'.
3193 : :
3194 : : When we have a conditional expression which might embed await expressions
3195 : : and/or promoted variables, we need to handle it appropriately.
3196 : :
3197 : : The linked lists for the 'then' and 'else' clauses in a conditional node
3198 : : identify the promoted variables (but these cannot be wrapped in a regular
3199 : : cleanup).
3200 : :
3201 : : So recurse through the lists and build up a composite list of captured vars.
3202 : : Declare these and any guard variables needed to decide if a DTOR should be
3203 : : run. Then embed the conditional into a try-finally expression that handles
3204 : : running each DTOR conditionally on its guard variable. */
3205 : :
3206 : : static void
3207 : 17 : process_conditional (var_nest_node *n, tree& vlist)
3208 : : {
3209 : 17 : tree init = n->init;
3210 : 17 : hash_map<tree, tree> var_flags;
3211 : 17 : auto_vec<tree> var_list;
3212 : 17 : tree new_then = push_stmt_list ();
3213 : 17 : handle_nested_conditionals (n->then_cl, var_list, var_flags);
3214 : 17 : new_then = pop_stmt_list (new_then);
3215 : 17 : tree new_else = push_stmt_list ();
3216 : 17 : handle_nested_conditionals (n->else_cl, var_list, var_flags);
3217 : 17 : new_else = pop_stmt_list (new_else);
3218 : : /* Declare the vars. There are two loops so that the boolean flags are
3219 : : grouped in the frame. */
3220 : 68 : for (unsigned i = 0; i < var_list.length(); i++)
3221 : : {
3222 : 17 : tree var = var_list[i];
3223 : 17 : DECL_CHAIN (var) = vlist;
3224 : 17 : vlist = var;
3225 : 17 : add_decl_expr (var);
3226 : : }
3227 : : /* Define the guard flags for variables that need a DTOR. */
3228 : 34 : for (unsigned i = 0; i < var_list.length(); i++)
3229 : : {
3230 : 17 : tree *flag = var_flags.get (var_list[i]);
3231 : 17 : if (flag)
3232 : : {
3233 : 0 : DECL_INITIAL (*flag) = boolean_false_node;
3234 : 0 : DECL_CHAIN (*flag) = vlist;
3235 : 0 : vlist = *flag;
3236 : 0 : add_decl_expr (*flag);
3237 : : }
3238 : : }
3239 : 17 : tree new_if
3240 : 17 : = build4 (IF_STMT, void_type_node, COND_EXPR_COND (init),
3241 : : new_then, new_else, NULL_TREE);
3242 : : /* Build a set of conditional DTORs. */
3243 : 17 : tree final_actions = push_stmt_list ();
3244 : 51 : while (!var_list.is_empty())
3245 : : {
3246 : 17 : tree var = var_list.pop ();
3247 : 17 : tree *flag = var_flags.get (var);
3248 : 34 : if (!flag)
3249 : 17 : continue;
3250 : 0 : if (tree cleanup = cxx_maybe_build_cleanup (var, tf_warning_or_error))
3251 : : {
3252 : 0 : tree cond_cleanup = begin_if_stmt ();
3253 : 0 : finish_if_stmt_cond (*flag, cond_cleanup);
3254 : 0 : finish_expr_stmt (cleanup);
3255 : 0 : finish_then_clause (cond_cleanup);
3256 : 0 : finish_if_stmt (cond_cleanup);
3257 : : }
3258 : : }
3259 : 17 : final_actions = pop_stmt_list (final_actions);
3260 : 17 : tree try_finally
3261 : 17 : = build2 (TRY_FINALLY_EXPR, void_type_node, new_if, final_actions);
3262 : 17 : add_stmt (try_finally);
3263 : 17 : }
3264 : :
3265 : : /* Given *STMT, that contains at least one await expression.
3266 : :
3267 : : The full expression represented in the original source code will contain
3268 : : suspension points, but it is still required that the lifetime of temporary
3269 : : values extends to the end of the expression.
3270 : :
3271 : : We already have a mechanism to 'promote' user-authored local variables
3272 : : to a coroutine frame counterpart (which allows explicit management of the
3273 : : lifetime across suspensions). The transform here re-writes STMT into
3274 : : a bind expression, promotes temporary values into local variables in that
3275 : : and flattens the statement into a series of cleanups.
3276 : :
3277 : : Conditional expressions are re-written to regular 'if' statements.
3278 : : The cleanups for variables initialized inside a conditional (including
3279 : : nested cases) are wrapped in a try-finally clause, with guard variables
3280 : : to determine which DTORs need to be run. */
3281 : :
3282 : : static tree
3283 : 3616 : maybe_promote_temps (tree *stmt, void *d)
3284 : : {
3285 : 3616 : susp_frame_data *awpts = (susp_frame_data *) d;
3286 : :
3287 : 3616 : location_t sloc = EXPR_LOCATION (*stmt);
3288 : 3616 : tree expr = *stmt;
3289 : : /* Strip off uninteresting wrappers. */
3290 : 3616 : if (TREE_CODE (expr) == CLEANUP_POINT_EXPR)
3291 : 3615 : expr = TREE_OPERAND (expr, 0);
3292 : 3616 : if (TREE_CODE (expr) == EXPR_STMT)
3293 : 3616 : expr = EXPR_STMT_EXPR (expr);
3294 : 3616 : if (TREE_CODE (expr) == CONVERT_EXPR
3295 : 3616 : && VOID_TYPE_P (TREE_TYPE (expr)))
3296 : 462 : expr = TREE_OPERAND (expr, 0);
3297 : 3616 : STRIP_NOPS (expr);
3298 : :
3299 : : /* We walk the statement trees, flattening it into an ordered list of
3300 : : variables with initializers and fragments corresponding to compound
3301 : : expressions, truth or/and if and ternary conditionals. Conditional
3302 : : expressions carry a nested list of fragments for the then and else
3303 : : clauses. We anchor to the 'bottom' of the fragment list; we will write
3304 : : a cleanup nest with one shell for each variable initialized. */
3305 : 3616 : var_nest_node *root = new var_nest_node (NULL_TREE, expr, NULL, NULL);
3306 : : /* Check to see we didn't promote one twice. */
3307 : 3616 : hash_set<tree> promoted_vars;
3308 : 3616 : hash_set<tree> used_temps;
3309 : 3616 : flatten_await_stmt (root, &promoted_vars, &used_temps, NULL);
3310 : :
3311 : 3616 : gcc_checking_assert (root->next == NULL);
3312 : 3616 : tree vlist = NULL_TREE;
3313 : 3616 : var_nest_node *t = root;
3314 : : /* We build the bind scope expression from the bottom-up.
3315 : : EXPR_LIST holds the inner expression nest at the current cleanup
3316 : : level (becoming the final expression list when we've exhausted the
3317 : : number of sub-expression fragments). */
3318 : 3616 : tree expr_list = NULL_TREE;
3319 : 7489 : do
3320 : : {
3321 : 7489 : tree new_list = push_stmt_list ();
3322 : : /* When we have a promoted variable, then add that to the bind scope
3323 : : and initialize it. When there's no promoted variable, we just need
3324 : : to run the initializer.
3325 : : If the initializer is a conditional expression, we need to collect
3326 : : and declare any promoted variables nested within it. DTORs for such
3327 : : variables must be run conditionally too.
3328 : :
3329 : : Since here we're synthetically processing code here, we've already
3330 : : emitted any Wunused-result warnings. Below, however, we call
3331 : : finish_expr_stmt, which will convert its operand to void, and could
3332 : : result in such a diagnostic being emitted. To avoid that, convert to
3333 : : void ahead of time. */
3334 : 7489 : if (t->var)
3335 : : {
3336 : 3869 : tree var = t->var;
3337 : 3869 : DECL_CHAIN (var) = vlist;
3338 : 3869 : vlist = var;
3339 : 3869 : add_decl_expr (var);
3340 : 3869 : if (TREE_CODE (t->init) == COND_EXPR)
3341 : 0 : process_conditional (t, vlist);
3342 : : else
3343 : 3869 : finish_expr_stmt (convert_to_void (t->init, ICV_STATEMENT, tf_none));
3344 : 3869 : if (tree cleanup = cxx_maybe_build_cleanup (var, tf_warning_or_error))
3345 : : {
3346 : 2180 : tree cl = build_stmt (sloc, CLEANUP_STMT, expr_list, cleanup, var);
3347 : 2180 : add_stmt (cl); /* push this onto the level above. */
3348 : : }
3349 : 1689 : else if (expr_list)
3350 : : {
3351 : 1687 : if (TREE_CODE (expr_list) != STATEMENT_LIST)
3352 : 1503 : add_stmt (expr_list);
3353 : 184 : else if (!tsi_end_p (tsi_start (expr_list)))
3354 : 184 : add_stmt (expr_list);
3355 : : }
3356 : : }
3357 : : else
3358 : : {
3359 : 3620 : if (TREE_CODE (t->init) == COND_EXPR)
3360 : 17 : process_conditional (t, vlist);
3361 : : else
3362 : 3603 : finish_expr_stmt (convert_to_void (t->init, ICV_STATEMENT, tf_none));
3363 : 3620 : if (expr_list)
3364 : : {
3365 : 8 : if (TREE_CODE (expr_list) != STATEMENT_LIST)
3366 : 4 : add_stmt (expr_list);
3367 : 4 : else if (!tsi_end_p (tsi_start (expr_list)))
3368 : 4 : add_stmt (expr_list);
3369 : : }
3370 : : }
3371 : 7489 : expr_list = pop_stmt_list (new_list);
3372 : 7489 : var_nest_node *old = t;
3373 : 7489 : t = t->prev;
3374 : 7489 : delete old;
3375 : 7489 : } while (t);
3376 : :
3377 : : /* Now produce the bind expression containing the 'promoted' temporaries
3378 : : as its variable list, and the cleanup nest as the statement. */
3379 : 3616 : tree await_bind = build3_loc (sloc, BIND_EXPR, void_type_node,
3380 : : NULL, NULL, NULL);
3381 : 3616 : BIND_EXPR_BODY (await_bind) = expr_list;
3382 : 3616 : BIND_EXPR_VARS (await_bind) = nreverse (vlist);
3383 : 3616 : tree b_block = make_node (BLOCK);
3384 : 3616 : if (!awpts->block_stack->is_empty ())
3385 : : {
3386 : 3616 : tree s_block = awpts->block_stack->last ();
3387 : 3616 : if (s_block)
3388 : : {
3389 : 3616 : BLOCK_SUPERCONTEXT (b_block) = s_block;
3390 : 3616 : BLOCK_CHAIN (b_block) = BLOCK_SUBBLOCKS (s_block);
3391 : 3616 : BLOCK_SUBBLOCKS (s_block) = b_block;
3392 : : }
3393 : : }
3394 : 3616 : BLOCK_VARS (b_block) = BIND_EXPR_VARS (await_bind) ;
3395 : 3616 : BIND_EXPR_BLOCK (await_bind) = b_block;
3396 : 3616 : TREE_SIDE_EFFECTS (await_bind) = TREE_SIDE_EFFECTS (BIND_EXPR_BODY (await_bind));
3397 : 3616 : *stmt = await_bind;
3398 : 3616 : hash_set<tree> visited;
3399 : 3616 : return cp_walk_tree (stmt, register_awaits, d, &visited);
3400 : 3616 : }
3401 : :
3402 : : /* Lightweight callback to determine two key factors:
3403 : : 1) If the statement/expression contains any await expressions.
3404 : : 2) If the statement/expression potentially requires a re-write to handle
3405 : : TRUTH_{AND,OR}IF_EXPRs since, in most cases, they will need expansion
3406 : : so that the await expressions are not processed in the case of the
3407 : : short-circuit arm.
3408 : :
3409 : : CO_YIELD expressions are re-written to their underlying co_await. */
3410 : :
3411 : : static tree
3412 : 145255 : analyze_expression_awaits (tree *stmt, int *do_subtree, void *d)
3413 : : {
3414 : 145255 : susp_frame_data *awpts = (susp_frame_data *) d;
3415 : :
3416 : 145255 : switch (TREE_CODE (*stmt))
3417 : : {
3418 : : default: return NULL_TREE;
3419 : 351 : case CO_YIELD_EXPR:
3420 : : /* co_yield is syntactic sugar, re-write it to co_await. */
3421 : 351 : *stmt = TREE_OPERAND (*stmt, 1);
3422 : : /* FALLTHROUGH */
3423 : 3691 : case CO_AWAIT_EXPR:
3424 : 3691 : awpts->saw_awaits++;
3425 : : /* A non-null initializer for the awaiter means we need to expand. */
3426 : 3691 : if (TREE_OPERAND (*stmt, 2))
3427 : 3610 : awpts->has_awaiter_init = true;
3428 : : break;
3429 : 35 : case TRUTH_ANDIF_EXPR:
3430 : 35 : case TRUTH_ORIF_EXPR:
3431 : 35 : {
3432 : : /* We don't need special action for awaits in the always-executed
3433 : : arm of a TRUTH_IF. */
3434 : 35 : if (tree res = cp_walk_tree (&TREE_OPERAND (*stmt, 0),
3435 : : analyze_expression_awaits, d, NULL))
3436 : : return res;
3437 : : /* However, if there are await expressions on the conditionally
3438 : : executed branch, we must expand the TRUTH_IF to ensure that the
3439 : : expanded await expression control-flow is fully contained in the
3440 : : conditionally executed code. */
3441 : 35 : unsigned aw_count = awpts->saw_awaits;
3442 : 35 : if (tree res = cp_walk_tree (&TREE_OPERAND (*stmt, 1),
3443 : : analyze_expression_awaits, d, NULL))
3444 : : return res;
3445 : 35 : if (awpts->saw_awaits > aw_count)
3446 : : {
3447 : 17 : awpts->truth_aoif_to_expand->add (*stmt);
3448 : 17 : awpts->needs_truth_if_exp = true;
3449 : : }
3450 : : /* We've done the sub-trees here. */
3451 : 35 : *do_subtree = 0;
3452 : : }
3453 : 35 : break;
3454 : : }
3455 : :
3456 : : return NULL_TREE; /* Recurse until done. */
3457 : : }
3458 : :
3459 : : /* Given *EXPR
3460 : : If EXPR contains a TRUTH_{AND,OR}IF_EXPR, TAOIE with an await expr on
3461 : : the conditionally executed branch, change this in a ternary operator.
3462 : :
3463 : : bool not_expr = TAOIE == TRUTH_ORIF_EXPR ? NOT : NOP;
3464 : : not_expr (always-exec expr) ? conditionally-exec expr : not_expr;
3465 : :
3466 : : Apply this recursively to the condition and the conditionally-exec
3467 : : branch. */
3468 : :
3469 : : struct truth_if_transform {
3470 : : tree *orig_stmt;
3471 : : tree scratch_var;
3472 : : hash_set<tree> *truth_aoif_to_expand;
3473 : : };
3474 : :
3475 : : static tree
3476 : 2427 : expand_one_truth_if (tree *expr, int *do_subtree, void *d)
3477 : : {
3478 : 2427 : truth_if_transform *xform = (truth_if_transform *) d;
3479 : :
3480 : 2427 : bool needs_not = false;
3481 : 2427 : switch (TREE_CODE (*expr))
3482 : : {
3483 : : default: break;
3484 : 8 : case TRUTH_ORIF_EXPR:
3485 : 8 : needs_not = true;
3486 : : /* FALLTHROUGH */
3487 : 17 : case TRUTH_ANDIF_EXPR:
3488 : 17 : {
3489 : 17 : if (!xform->truth_aoif_to_expand->contains (*expr))
3490 : : break;
3491 : :
3492 : 17 : location_t sloc = EXPR_LOCATION (*expr);
3493 : : /* Transform truth expression into a cond expression with
3494 : : * the always-executed arm as the condition.
3495 : : * the conditionally-executed arm as the then clause.
3496 : : * the 'else' clause is fixed: 'true' for ||,'false' for &&. */
3497 : 17 : tree cond = TREE_OPERAND (*expr, 0);
3498 : 17 : tree test1 = TREE_OPERAND (*expr, 1);
3499 : 17 : tree fixed = needs_not ? boolean_true_node : boolean_false_node;
3500 : 9 : if (needs_not)
3501 : 8 : cond = build1 (TRUTH_NOT_EXPR, boolean_type_node, cond);
3502 : 17 : tree cond_expr
3503 : 17 : = build3_loc (sloc, COND_EXPR, boolean_type_node,
3504 : : cond, test1, fixed);
3505 : 17 : *expr = cond_expr;
3506 : 17 : if (tree res = cp_walk_tree (&COND_EXPR_COND (*expr),
3507 : : expand_one_truth_if, d, NULL))
3508 : : return res;
3509 : 17 : if (tree res = cp_walk_tree (&COND_EXPR_THEN (*expr),
3510 : : expand_one_truth_if, d, NULL))
3511 : : return res;
3512 : : /* We've manually processed necessary sub-trees here. */
3513 : 17 : *do_subtree = 0;
3514 : : }
3515 : 17 : break;
3516 : : }
3517 : : return NULL_TREE;
3518 : : }
3519 : :
3520 : : /* Helper that adds a new variable of VAR_TYPE to a bind scope BIND, the
3521 : : name is made up from NAM_ROOT, NAM_VERS. */
3522 : :
3523 : : static tree
3524 : 65 : add_var_to_bind (tree& bind, tree var_type,
3525 : : const char *nam_root, unsigned nam_vers)
3526 : : {
3527 : 65 : tree b_vars = BIND_EXPR_VARS (bind);
3528 : : /* Build a variable to hold the condition, this will be included in the
3529 : : frame as a local var. */
3530 : 65 : char *nam = xasprintf ("__%s_%d", nam_root, nam_vers);
3531 : 65 : tree newvar = build_lang_decl (VAR_DECL, get_identifier (nam), var_type);
3532 : 65 : free (nam);
3533 : 65 : DECL_CHAIN (newvar) = b_vars;
3534 : 65 : BIND_EXPR_VARS (bind) = newvar;
3535 : 65 : return newvar;
3536 : : }
3537 : :
3538 : : /* Helper to build and add if (!cond) break; */
3539 : :
3540 : : static void
3541 : 39 : coro_build_add_if_not_cond_break (tree cond)
3542 : : {
3543 : 39 : tree if_stmt = begin_if_stmt ();
3544 : 39 : tree invert = build1 (TRUTH_NOT_EXPR, boolean_type_node, cond);
3545 : 39 : finish_if_stmt_cond (invert, if_stmt);
3546 : 39 : finish_break_stmt ();
3547 : 39 : finish_then_clause (if_stmt);
3548 : 39 : finish_if_stmt (if_stmt);
3549 : 39 : }
3550 : :
3551 : : /* Tree walk callback to replace continue statements with goto label. */
3552 : : static tree
3553 : 1004 : replace_continue (tree *stmt, int *do_subtree, void *d)
3554 : : {
3555 : 1004 : tree expr = *stmt;
3556 : 1004 : if (TREE_CODE (expr) == CLEANUP_POINT_EXPR)
3557 : 36 : expr = TREE_OPERAND (expr, 0);
3558 : 1004 : if (CONVERT_EXPR_P (expr) && VOID_TYPE_P (TREE_TYPE (expr)))
3559 : 36 : expr = TREE_OPERAND (expr, 0);
3560 : 1004 : STRIP_NOPS (expr);
3561 : 1004 : if (!STATEMENT_CLASS_P (expr))
3562 : : return NULL_TREE;
3563 : :
3564 : 40 : switch (TREE_CODE (expr))
3565 : : {
3566 : : /* Unless it's a special case, just walk the subtrees as usual. */
3567 : : default: return NULL_TREE;
3568 : :
3569 : 9 : case CONTINUE_STMT:
3570 : 9 : {
3571 : 9 : tree *label = (tree *)d;
3572 : 9 : location_t loc = EXPR_LOCATION (expr);
3573 : : /* re-write a continue to goto label. */
3574 : 9 : *stmt = build_stmt (loc, GOTO_EXPR, *label);
3575 : 9 : *do_subtree = 0;
3576 : 9 : return NULL_TREE;
3577 : : }
3578 : :
3579 : : /* Statements that do not require recursion. */
3580 : 18 : case DECL_EXPR:
3581 : 18 : case BREAK_STMT:
3582 : 18 : case GOTO_EXPR:
3583 : 18 : case LABEL_EXPR:
3584 : 18 : case CASE_LABEL_EXPR:
3585 : 18 : case ASM_EXPR:
3586 : : /* These must break recursion. */
3587 : 18 : case FOR_STMT:
3588 : 18 : case WHILE_STMT:
3589 : 18 : case DO_STMT:
3590 : 18 : *do_subtree = 0;
3591 : 18 : return NULL_TREE;
3592 : : }
3593 : : }
3594 : :
3595 : : /* Tree walk callback to analyze, register and pre-process statements that
3596 : : contain await expressions. */
3597 : :
3598 : : static tree
3599 : 164202 : await_statement_walker (tree *stmt, int *do_subtree, void *d)
3600 : : {
3601 : 164202 : tree res = NULL_TREE;
3602 : 164202 : susp_frame_data *awpts = (susp_frame_data *) d;
3603 : :
3604 : : /* Process a statement at a time. */
3605 : 164202 : if (TREE_CODE (*stmt) == BIND_EXPR)
3606 : : {
3607 : : /* For conditional expressions, we might wish to add an artificial var
3608 : : to their containing bind expr. */
3609 : 2984 : vec_safe_push (awpts->bind_stack, *stmt);
3610 : : /* We might need to insert a new bind expression, and want to link it
3611 : : into the correct scope, so keep a note of the current block scope. */
3612 : 2984 : tree blk = BIND_EXPR_BLOCK (*stmt);
3613 : 2984 : vec_safe_push (awpts->block_stack, blk);
3614 : 2984 : res = cp_walk_tree (&BIND_EXPR_BODY (*stmt), await_statement_walker,
3615 : : d, NULL);
3616 : 2984 : awpts->block_stack->pop ();
3617 : 2984 : awpts->bind_stack->pop ();
3618 : 2984 : *do_subtree = 0; /* Done subtrees. */
3619 : 2984 : return res;
3620 : : }
3621 : 161218 : else if (TREE_CODE (*stmt) == STATEMENT_LIST)
3622 : : {
3623 : 39270 : for (tree &s : tsi_range (*stmt))
3624 : : {
3625 : 32497 : res = cp_walk_tree (&s, await_statement_walker,
3626 : : d, NULL);
3627 : 32497 : if (res)
3628 : 164202 : return res;
3629 : : }
3630 : 6773 : *do_subtree = 0; /* Done subtrees. */
3631 : 6773 : return NULL_TREE;
3632 : : }
3633 : :
3634 : : /* We have something to be handled as a single statement. We have to handle
3635 : : a few statements specially where await statements have to be moved out of
3636 : : constructs. */
3637 : 154445 : tree expr = *stmt;
3638 : 154445 : if (TREE_CODE (*stmt) == CLEANUP_POINT_EXPR)
3639 : 16517 : expr = TREE_OPERAND (expr, 0);
3640 : 154445 : STRIP_NOPS (expr);
3641 : :
3642 : 154445 : if (STATEMENT_CLASS_P (expr))
3643 : 23676 : switch (TREE_CODE (expr))
3644 : : {
3645 : : /* Unless it's a special case, just walk the subtrees as usual. */
3646 : : default: return NULL_TREE;
3647 : :
3648 : : /* When we have a conditional expression, which contains one or more
3649 : : await expressions, we have to break the condition out into a
3650 : : regular statement so that the control flow introduced by the await
3651 : : transforms can be implemented. */
3652 : 1671 : case IF_STMT:
3653 : 1671 : {
3654 : 1671 : tree *await_ptr;
3655 : 1671 : hash_set<tree> visited;
3656 : : /* Transform 'if (cond with awaits) then stmt1 else stmt2' into
3657 : : bool cond = cond with awaits.
3658 : : if (cond) then stmt1 else stmt2. */
3659 : 1671 : tree if_stmt = *stmt;
3660 : : /* We treat the condition as if it was a stand-alone statement,
3661 : : to see if there are any await expressions which will be analyzed
3662 : : and registered. */
3663 : 1671 : if (!(cp_walk_tree (&IF_COND (if_stmt),
3664 : : find_any_await, &await_ptr, &visited)))
3665 : : return NULL_TREE; /* Nothing special to do here. */
3666 : :
3667 : 56 : gcc_checking_assert (!awpts->bind_stack->is_empty());
3668 : 56 : tree& bind_expr = awpts->bind_stack->last ();
3669 : 112 : tree newvar = add_var_to_bind (bind_expr, boolean_type_node,
3670 : 56 : "ifcd", awpts->cond_number++);
3671 : 56 : tree insert_list = push_stmt_list ();
3672 : 56 : tree cond_inner = IF_COND (if_stmt);
3673 : 56 : if (TREE_CODE (cond_inner) == CLEANUP_POINT_EXPR)
3674 : 56 : cond_inner = TREE_OPERAND (cond_inner, 0);
3675 : 56 : add_decl_expr (newvar);
3676 : 56 : location_t sloc = EXPR_LOCATION (IF_COND (if_stmt));
3677 : : /* We want to initialize the new variable with the expression
3678 : : that contains the await(s) and potentially also needs to
3679 : : have truth_if expressions expanded. */
3680 : 56 : tree new_s = cp_build_init_expr (sloc, newvar, cond_inner);
3681 : 56 : finish_expr_stmt (new_s);
3682 : 56 : IF_COND (if_stmt) = newvar;
3683 : 56 : add_stmt (if_stmt);
3684 : 56 : *stmt = pop_stmt_list (insert_list);
3685 : : /* So now walk the new statement list. */
3686 : 56 : res = cp_walk_tree (stmt, await_statement_walker, d, NULL);
3687 : 56 : *do_subtree = 0; /* Done subtrees. */
3688 : 56 : return res;
3689 : 1671 : }
3690 : 134 : break;
3691 : 134 : case FOR_STMT:
3692 : 134 : {
3693 : 134 : tree *await_ptr;
3694 : 134 : hash_set<tree> visited;
3695 : : /* for loops only need special treatment if the condition or the
3696 : : iteration expression contain a co_await. */
3697 : 134 : tree for_stmt = *stmt;
3698 : : /* At present, the FE always generates a separate initializer for
3699 : : the FOR_INIT_STMT, when the expression has an await. Check that
3700 : : this assumption holds in the future. */
3701 : 134 : gcc_checking_assert
3702 : : (!(cp_walk_tree (&FOR_INIT_STMT (for_stmt), find_any_await,
3703 : : &await_ptr, &visited)));
3704 : :
3705 : 134 : visited.empty ();
3706 : 134 : bool for_cond_await
3707 : 134 : = cp_walk_tree (&FOR_COND (for_stmt), find_any_await,
3708 : : &await_ptr, &visited);
3709 : :
3710 : 134 : visited.empty ();
3711 : 134 : bool for_expr_await
3712 : 134 : = cp_walk_tree (&FOR_EXPR (for_stmt), find_any_await,
3713 : : &await_ptr, &visited);
3714 : :
3715 : : /* If the condition has an await, then we will need to rewrite the
3716 : : loop as
3717 : : for (init expression;true;iteration expression) {
3718 : : condition = await expression;
3719 : : if (condition)
3720 : : break;
3721 : : ...
3722 : : }
3723 : : */
3724 : 134 : if (for_cond_await)
3725 : : {
3726 : 19 : tree insert_list = push_stmt_list ();
3727 : : /* This will be expanded when the revised body is handled. */
3728 : 19 : coro_build_add_if_not_cond_break (FOR_COND (for_stmt));
3729 : : /* .. add the original for body. */
3730 : 19 : add_stmt (FOR_BODY (for_stmt));
3731 : : /* To make the new for body. */
3732 : 19 : FOR_BODY (for_stmt) = pop_stmt_list (insert_list);
3733 : 19 : FOR_COND (for_stmt) = boolean_true_node;
3734 : : }
3735 : : /* If the iteration expression has an await, it's a bit more
3736 : : tricky.
3737 : : for (init expression;condition;) {
3738 : : ...
3739 : : iteration_expr_label:
3740 : : iteration expression with await;
3741 : : }
3742 : : but, then we will need to re-write any continue statements into
3743 : : 'goto iteration_expr_label:'.
3744 : : */
3745 : 134 : if (for_expr_await)
3746 : : {
3747 : 18 : location_t sloc = EXPR_LOCATION (FOR_EXPR (for_stmt));
3748 : 18 : tree insert_list = push_stmt_list ();
3749 : : /* The original for body. */
3750 : 18 : add_stmt (FOR_BODY (for_stmt));
3751 : 18 : char *buf = xasprintf ("for.iter.expr.%u", awpts->cond_number++);
3752 : 18 : tree it_expr_label
3753 : 18 : = create_named_label_with_ctx (sloc, buf, NULL_TREE);
3754 : 18 : free (buf);
3755 : 18 : add_stmt (build_stmt (sloc, LABEL_EXPR, it_expr_label));
3756 : 18 : tree for_expr = FOR_EXPR (for_stmt);
3757 : : /* Present the iteration expression as a statement. */
3758 : 18 : if (TREE_CODE (for_expr) == CLEANUP_POINT_EXPR)
3759 : 18 : for_expr = TREE_OPERAND (for_expr, 0);
3760 : 18 : STRIP_NOPS (for_expr);
3761 : 18 : finish_expr_stmt (for_expr);
3762 : 18 : FOR_EXPR (for_stmt) = NULL_TREE;
3763 : 18 : FOR_BODY (for_stmt) = pop_stmt_list (insert_list);
3764 : : /* rewrite continue statements to goto label. */
3765 : 18 : hash_set<tree> visited_continue;
3766 : 18 : if ((res = cp_walk_tree (&FOR_BODY (for_stmt),
3767 : : replace_continue, &it_expr_label, &visited_continue)))
3768 : 0 : return res;
3769 : 18 : }
3770 : :
3771 : : /* So now walk the body statement (list), if there were no await
3772 : : expressions, then this handles the original body - and either
3773 : : way we will have finished with this statement. */
3774 : 134 : res = cp_walk_tree (&FOR_BODY (for_stmt),
3775 : : await_statement_walker, d, NULL);
3776 : 134 : *do_subtree = 0; /* Done subtrees. */
3777 : 134 : return res;
3778 : 134 : }
3779 : 11 : break;
3780 : 11 : case WHILE_STMT:
3781 : 11 : {
3782 : : /* We turn 'while (cond with awaits) stmt' into
3783 : : while (true) {
3784 : : if (!(cond with awaits))
3785 : : break;
3786 : : stmt..
3787 : : } */
3788 : 11 : tree *await_ptr;
3789 : 11 : hash_set<tree> visited;
3790 : 11 : tree while_stmt = *stmt;
3791 : 11 : if (!(cp_walk_tree (&WHILE_COND (while_stmt),
3792 : : find_any_await, &await_ptr, &visited)))
3793 : : return NULL_TREE; /* Nothing special to do here. */
3794 : :
3795 : 11 : tree insert_list = push_stmt_list ();
3796 : 11 : coro_build_add_if_not_cond_break (WHILE_COND (while_stmt));
3797 : : /* The original while body. */
3798 : 11 : add_stmt (WHILE_BODY (while_stmt));
3799 : : /* The new while body. */
3800 : 11 : WHILE_BODY (while_stmt) = pop_stmt_list (insert_list);
3801 : 11 : WHILE_COND (while_stmt) = boolean_true_node;
3802 : : /* So now walk the new statement list. */
3803 : 11 : res = cp_walk_tree (&WHILE_BODY (while_stmt),
3804 : : await_statement_walker, d, NULL);
3805 : 11 : *do_subtree = 0; /* Done subtrees. */
3806 : 11 : return res;
3807 : 11 : }
3808 : 13 : break;
3809 : 13 : case DO_STMT:
3810 : 13 : {
3811 : : /* We turn do stmt while (cond with awaits) into:
3812 : : do {
3813 : : stmt..
3814 : : if (!(cond with awaits))
3815 : : break;
3816 : : } while (true); */
3817 : 13 : tree do_stmt = *stmt;
3818 : 13 : tree *await_ptr;
3819 : 13 : hash_set<tree> visited;
3820 : 13 : if (!(cp_walk_tree (&DO_COND (do_stmt),
3821 : : find_any_await, &await_ptr, &visited)))
3822 : : return NULL_TREE; /* Nothing special to do here. */
3823 : :
3824 : 9 : tree insert_list = push_stmt_list ();
3825 : : /* The original do stmt body. */
3826 : 9 : add_stmt (DO_BODY (do_stmt));
3827 : 9 : coro_build_add_if_not_cond_break (DO_COND (do_stmt));
3828 : : /* The new while body. */
3829 : 9 : DO_BODY (do_stmt) = pop_stmt_list (insert_list);
3830 : 9 : DO_COND (do_stmt) = boolean_true_node;
3831 : : /* So now walk the new statement list. */
3832 : 9 : res = cp_walk_tree (&DO_BODY (do_stmt), await_statement_walker,
3833 : : d, NULL);
3834 : 9 : *do_subtree = 0; /* Done subtrees. */
3835 : 9 : return res;
3836 : 13 : }
3837 : 19 : break;
3838 : 19 : case SWITCH_STMT:
3839 : 19 : {
3840 : : /* We turn 'switch (cond with awaits) stmt' into
3841 : : switch_type cond = cond with awaits
3842 : : switch (cond) stmt. */
3843 : 19 : tree sw_stmt = *stmt;
3844 : 19 : tree *await_ptr;
3845 : 19 : hash_set<tree> visited;
3846 : 19 : if (!(cp_walk_tree (&SWITCH_STMT_COND (sw_stmt),
3847 : : find_any_await, &await_ptr, &visited)))
3848 : : return NULL_TREE; /* Nothing special to do here. */
3849 : :
3850 : 9 : gcc_checking_assert (!awpts->bind_stack->is_empty());
3851 : : /* Build a variable to hold the condition, this will be
3852 : : included in the frame as a local var. */
3853 : 9 : tree& bind_expr = awpts->bind_stack->last ();
3854 : 9 : tree sw_type = SWITCH_STMT_TYPE (sw_stmt);
3855 : 18 : tree newvar = add_var_to_bind (bind_expr, sw_type, "swch",
3856 : 9 : awpts->cond_number++);
3857 : 9 : tree insert_list = push_stmt_list ();
3858 : 9 : add_decl_expr (newvar);
3859 : :
3860 : 9 : tree cond_inner = SWITCH_STMT_COND (sw_stmt);
3861 : 9 : if (TREE_CODE (cond_inner) == CLEANUP_POINT_EXPR)
3862 : 9 : cond_inner = TREE_OPERAND (cond_inner, 0);
3863 : 9 : location_t sloc = EXPR_LOCATION (SWITCH_STMT_COND (sw_stmt));
3864 : 9 : tree new_s = cp_build_init_expr (sloc, newvar,
3865 : : cond_inner);
3866 : 9 : finish_expr_stmt (new_s);
3867 : 9 : SWITCH_STMT_COND (sw_stmt) = newvar;
3868 : : /* Now add the switch statement with the condition re-
3869 : : written to use the local var. */
3870 : 9 : add_stmt (sw_stmt);
3871 : 9 : *stmt = pop_stmt_list (insert_list);
3872 : : /* Process the expanded list. */
3873 : 9 : res = cp_walk_tree (stmt, await_statement_walker,
3874 : : d, NULL);
3875 : 9 : *do_subtree = 0; /* Done subtrees. */
3876 : 9 : return res;
3877 : 19 : }
3878 : 1394 : break;
3879 : 1394 : case CO_RETURN_EXPR:
3880 : 1394 : {
3881 : : /* Expand the co_return as per [stmt.return.coroutine]
3882 : : - for co_return;
3883 : : { p.return_void (); goto final_suspend; }
3884 : : - for co_return [void expr];
3885 : : { expr; p.return_void(); goto final_suspend;}
3886 : : - for co_return [non void expr];
3887 : : { p.return_value(expr); goto final_suspend; } */
3888 : 1394 : location_t loc = EXPR_LOCATION (expr);
3889 : 1394 : tree call = TREE_OPERAND (expr, 1);
3890 : 1394 : expr = TREE_OPERAND (expr, 0);
3891 : 1394 : tree ret_list = push_stmt_list ();
3892 : : /* [stmt.return.coroutine], 2.2
3893 : : If expr is present and void, it is placed immediately before
3894 : : the call for return_void; */
3895 : 1394 : if (expr && VOID_TYPE_P (TREE_TYPE (expr)))
3896 : 11 : finish_expr_stmt (expr);
3897 : : /* Insert p.return_{void,value(expr)}. */
3898 : 1394 : finish_expr_stmt (call);
3899 : 1394 : TREE_USED (awpts->fs_label) = 1;
3900 : 1394 : add_stmt (build_stmt (loc, GOTO_EXPR, awpts->fs_label));
3901 : 1394 : *stmt = pop_stmt_list (ret_list);
3902 : 1394 : res = cp_walk_tree (stmt, await_statement_walker, d, NULL);
3903 : : /* Once this is complete, we will have processed subtrees. */
3904 : 1394 : *do_subtree = 0;
3905 : 1394 : return res;
3906 : : }
3907 : 1360 : break;
3908 : 1360 : case HANDLER:
3909 : 1360 : {
3910 : : /* [expr.await] An await-expression shall appear only in a
3911 : : potentially-evaluated expression within the compound-statement
3912 : : of a function-body outside of a handler. */
3913 : 1360 : tree *await_ptr;
3914 : 1360 : hash_set<tree> visited;
3915 : 1360 : if (!(cp_walk_tree (&HANDLER_BODY (expr), find_any_await,
3916 : : &await_ptr, &visited)))
3917 : : return NULL_TREE; /* All OK. */
3918 : 1 : location_t loc = EXPR_LOCATION (*await_ptr);
3919 : 1 : error_at (loc, "await expressions are not permitted in handlers");
3920 : 1 : return NULL_TREE; /* This is going to fail later anyway. */
3921 : 1360 : }
3922 : 130769 : break;
3923 : : }
3924 : 130769 : else if (EXPR_P (expr))
3925 : : {
3926 : 60736 : hash_set<tree> visited;
3927 : 60736 : tree *await_ptr;
3928 : 60736 : if (!(cp_walk_tree (stmt, find_any_await, &await_ptr, &visited)))
3929 : : return NULL_TREE; /* Nothing special to do here. */
3930 : :
3931 : 3616 : visited.empty ();
3932 : 3616 : awpts->saw_awaits = 0;
3933 : 3616 : hash_set<tree> truth_aoif_to_expand;
3934 : 3616 : awpts->truth_aoif_to_expand = &truth_aoif_to_expand;
3935 : 3616 : awpts->needs_truth_if_exp = false;
3936 : 3616 : awpts->has_awaiter_init = false;
3937 : 3616 : if ((res = cp_walk_tree (stmt, analyze_expression_awaits, d, &visited)))
3938 : : return res;
3939 : 3616 : *do_subtree = 0; /* Done subtrees. */
3940 : 3616 : if (!awpts->saw_awaits)
3941 : : return NULL_TREE; /* Nothing special to do here. */
3942 : :
3943 : 3616 : if (awpts->needs_truth_if_exp)
3944 : : {
3945 : : /* If a truth-and/or-if expression has an await expression in the
3946 : : conditionally-taken branch, then it must be rewritten into a
3947 : : regular conditional. */
3948 : 17 : truth_if_transform xf = {stmt, NULL_TREE, &truth_aoif_to_expand};
3949 : 17 : if ((res = cp_walk_tree (stmt, expand_one_truth_if, &xf, NULL)))
3950 : 0 : return res;
3951 : : }
3952 : : /* Process this statement, which contains at least one await expression
3953 : : to 'promote' temporary values to a coroutine frame slot. */
3954 : 3616 : return maybe_promote_temps (stmt, d);
3955 : 64352 : }
3956 : : /* Continue recursion, if needed. */
3957 : : return res;
3958 : : }
3959 : :
3960 : : /* For figuring out what param usage we have. */
3961 : :
3962 : : struct param_frame_data
3963 : : {
3964 : : tree *field_list;
3965 : : hash_map<tree, param_info> *param_uses;
3966 : : hash_set<tree *> *visited;
3967 : : location_t loc;
3968 : : bool param_seen;
3969 : : };
3970 : :
3971 : : /* A tree walk callback that rewrites each parm use to the local variable
3972 : : that represents its copy in the frame. */
3973 : :
3974 : : static tree
3975 : 104427 : rewrite_param_uses (tree *stmt, int *do_subtree ATTRIBUTE_UNUSED, void *d)
3976 : : {
3977 : 104427 : param_frame_data *data = (param_frame_data *) d;
3978 : :
3979 : : /* For lambda closure content, we have to look specifically. */
3980 : 104427 : if (VAR_P (*stmt) && DECL_HAS_VALUE_EXPR_P (*stmt))
3981 : : {
3982 : 726 : tree t = DECL_VALUE_EXPR (*stmt);
3983 : 726 : return cp_walk_tree (&t, rewrite_param_uses, d, NULL);
3984 : : }
3985 : :
3986 : 103701 : if (unevaluated_p (TREE_CODE (*stmt)))
3987 : : {
3988 : : /* No odr-uses in unevaluated operands. */
3989 : 1 : *do_subtree = 0;
3990 : 1 : return NULL_TREE;
3991 : : }
3992 : :
3993 : 103700 : if (TREE_CODE (*stmt) != PARM_DECL)
3994 : : return NULL_TREE;
3995 : :
3996 : : /* If we already saw the containing expression, then we're done. */
3997 : 994 : if (data->visited->add (stmt))
3998 : : return NULL_TREE;
3999 : :
4000 : 994 : bool existed;
4001 : 994 : param_info &parm = data->param_uses->get_or_insert (*stmt, &existed);
4002 : 994 : gcc_checking_assert (existed);
4003 : :
4004 : 994 : *stmt = parm.copy_var;
4005 : 994 : return NULL_TREE;
4006 : : }
4007 : :
4008 : : /* Build up a set of info that determines how each param copy will be
4009 : : handled. */
4010 : :
4011 : : static void
4012 : 1348 : analyze_fn_parms (tree orig, hash_map<tree, param_info> *param_uses)
4013 : : {
4014 : 1348 : if (!DECL_ARGUMENTS (orig))
4015 : : return;
4016 : :
4017 : : /* Build a hash map with an entry for each param.
4018 : : The key is the param tree.
4019 : : Then we have an entry for the frame field name.
4020 : : Then a cache for the field ref when we come to use it.
4021 : : Then a tree list of the uses.
4022 : : The second two entries start out empty - and only get populated
4023 : : when we see uses. */
4024 : 841 : bool lambda_p = LAMBDA_FUNCTION_P (orig);
4025 : :
4026 : : /* Count the param copies from 1 as per the std. */
4027 : 678 : unsigned parm_num = 1;
4028 : 1561 : for (tree arg = DECL_ARGUMENTS (orig); arg != NULL;
4029 : 883 : ++parm_num, arg = DECL_CHAIN (arg))
4030 : : {
4031 : 883 : bool existed;
4032 : 883 : param_info &parm = param_uses->get_or_insert (arg, &existed);
4033 : 883 : gcc_checking_assert (!existed);
4034 : 883 : parm.body_uses = NULL;
4035 : 883 : tree actual_type = TREE_TYPE (arg);
4036 : 883 : actual_type = complete_type_or_else (actual_type, orig);
4037 : 883 : if (actual_type == NULL_TREE)
4038 : 0 : actual_type = error_mark_node;
4039 : 883 : parm.orig_type = actual_type;
4040 : 883 : parm.by_ref = parm.pt_ref = parm.rv_ref = false;
4041 : 883 : if (TREE_CODE (actual_type) == REFERENCE_TYPE)
4042 : : {
4043 : : /* If the user passes by reference, then we will save the
4044 : : pointer to the original. As noted in
4045 : : [dcl.fct.def.coroutine] / 13, if the lifetime of the
4046 : : referenced item ends and then the coroutine is resumed,
4047 : : we have UB; well, the user asked for it. */
4048 : 112 : if (TYPE_REF_IS_RVALUE (actual_type))
4049 : 32 : parm.rv_ref = true;
4050 : : else
4051 : 80 : parm.pt_ref = true;
4052 : : }
4053 : 771 : else if (TYPE_REF_P (DECL_ARG_TYPE (arg)))
4054 : 81 : parm.by_ref = true;
4055 : :
4056 : 883 : parm.frame_type = actual_type;
4057 : :
4058 : 883 : parm.this_ptr = is_this_parameter (arg);
4059 : 883 : parm.lambda_cobj = lambda_p && DECL_NAME (arg) == closure_identifier;
4060 : :
4061 : 883 : tree name = DECL_NAME (arg);
4062 : 883 : if (!name)
4063 : : {
4064 : 39 : char *buf = xasprintf ("_Coro_q%u___unnamed", parm_num);
4065 : 39 : name = get_identifier (buf);
4066 : 39 : free (buf);
4067 : : }
4068 : 883 : parm.field_id = name;
4069 : 883 : if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (parm.frame_type))
4070 : : {
4071 : 81 : char *buf = xasprintf ("_Coro_q%u_%s_live", parm_num,
4072 : 157 : DECL_NAME (arg) ? IDENTIFIER_POINTER (name)
4073 : : : "__unnamed");
4074 : 81 : parm.guard_var
4075 : 81 : = coro_build_artificial_var (UNKNOWN_LOCATION, get_identifier (buf),
4076 : : boolean_type_node, orig,
4077 : : boolean_false_node);
4078 : 81 : free (buf);
4079 : 81 : parm.trivial_dtor = false;
4080 : : }
4081 : : else
4082 : 802 : parm.trivial_dtor = true;
4083 : : }
4084 : : }
4085 : :
4086 : : /* Small helper for the repetitive task of adding a new field to the coro
4087 : : frame type. */
4088 : :
4089 : : static tree
4090 : 15030 : coro_make_frame_entry (tree *field_list, const char *name, tree fld_type,
4091 : : location_t loc)
4092 : : {
4093 : 15030 : tree id = get_identifier (name);
4094 : 15030 : tree decl = build_decl (loc, FIELD_DECL, id, fld_type);
4095 : 15030 : DECL_CHAIN (decl) = *field_list;
4096 : 15030 : *field_list = decl;
4097 : 15030 : return id;
4098 : : }
4099 : :
4100 : : /* A tree-walk callback that processes one bind expression noting local
4101 : : variables, and making a coroutine frame slot available for those that
4102 : : need it, so that they can be 'promoted' across suspension points. */
4103 : :
4104 : : static tree
4105 : 321102 : register_local_var_uses (tree *stmt, int *do_subtree, void *d)
4106 : : {
4107 : 321102 : if (TREE_CODE (*stmt) != BIND_EXPR)
4108 : : return NULL_TREE;
4109 : :
4110 : 6602 : local_vars_frame_data *lvd = (local_vars_frame_data *) d;
4111 : :
4112 : : /* As we enter a bind expression - record the vars there and then recurse.
4113 : : As we exit drop the nest depth.
4114 : : The bind index is a growing count of how many bind indices we've seen.
4115 : : We build a space in the frame for each local var. */
4116 : :
4117 : 6602 : tree lvar;
4118 : 6602 : unsigned serial = 0;
4119 : 21775 : for (lvar = BIND_EXPR_VARS (*stmt); lvar != NULL; lvar = DECL_CHAIN (lvar))
4120 : : {
4121 : 15173 : bool existed;
4122 : 15173 : local_var_info &local_var
4123 : 15173 : = lvd->local_var_uses->get_or_insert (lvar, &existed);
4124 : 15173 : gcc_checking_assert (!existed);
4125 : 15173 : local_var.def_loc = DECL_SOURCE_LOCATION (lvar);
4126 : 15173 : tree lvtype = TREE_TYPE (lvar);
4127 : 15173 : local_var.frame_type = lvtype;
4128 : 15173 : local_var.field_idx = local_var.field_id = NULL_TREE;
4129 : :
4130 : : /* Make sure that we only present vars to the tests below. */
4131 : 15173 : if (TREE_CODE (lvar) != PARM_DECL
4132 : 15173 : && TREE_CODE (lvar) != VAR_DECL)
4133 : 143 : continue;
4134 : :
4135 : : /* We don't move static vars into the frame. */
4136 : 15152 : local_var.is_static = TREE_STATIC (lvar);
4137 : 15152 : if (local_var.is_static)
4138 : 3 : continue;
4139 : :
4140 : 15149 : poly_uint64 size;
4141 : 15150 : if (TREE_CODE (lvtype) == ARRAY_TYPE
4142 : 15149 : && !poly_int_tree_p (DECL_SIZE_UNIT (lvar), &size))
4143 : : {
4144 : 1 : sorry_at (local_var.def_loc, "variable length arrays are not"
4145 : : " yet supported in coroutines");
4146 : : /* Ignore it, this is broken anyway. */
4147 : 1 : continue;
4148 : : }
4149 : :
4150 : 15148 : lvd->local_var_seen = true;
4151 : : /* If this var is a lambda capture proxy, we want to leave it alone,
4152 : : and later rewrite the DECL_VALUE_EXPR to indirect through the
4153 : : frame copy of the pointer to the lambda closure object. */
4154 : 15148 : local_var.is_lambda_capture = is_capture_proxy (lvar);
4155 : 15148 : if (local_var.is_lambda_capture)
4156 : 110 : continue;
4157 : :
4158 : : /* If a variable has a value expression, then that's what needs
4159 : : to be processed. */
4160 : 15038 : local_var.has_value_expr_p = DECL_HAS_VALUE_EXPR_P (lvar);
4161 : 15038 : if (local_var.has_value_expr_p)
4162 : 8 : continue;
4163 : :
4164 : : /* Make names depth+index unique, so that we can support nested
4165 : : scopes with identically named locals and still be able to
4166 : : identify them in the coroutine frame. */
4167 : 15030 : tree lvname = DECL_NAME (lvar);
4168 : 15030 : char *buf = NULL;
4169 : :
4170 : : /* The outermost bind scope contains the artificial variables that
4171 : : we inject to implement the coro state machine. We want to be able
4172 : : to inspect these in debugging. */
4173 : 15030 : if (lvname != NULL_TREE && lvd->nest_depth == 0)
4174 : 10312 : buf = xasprintf ("%s", IDENTIFIER_POINTER (lvname));
4175 : 4682 : else if (lvname != NULL_TREE)
4176 : 4682 : buf = xasprintf ("%s_%u_%u", IDENTIFIER_POINTER (lvname),
4177 : : lvd->nest_depth, lvd->bind_indx);
4178 : : else
4179 : 36 : buf = xasprintf ("_D%u_%u_%u", lvd->nest_depth, lvd->bind_indx,
4180 : : serial++);
4181 : :
4182 : : /* TODO: Figure out if we should build a local type that has any
4183 : : excess alignment or size from the original decl. */
4184 : 15030 : local_var.field_id = coro_make_frame_entry (lvd->field_list, buf,
4185 : : lvtype, lvd->loc);
4186 : 15030 : free (buf);
4187 : : /* We don't walk any of the local var sub-trees, they won't contain
4188 : : any bind exprs. */
4189 : : }
4190 : 6602 : lvd->bind_indx++;
4191 : 6602 : lvd->nest_depth++;
4192 : : /* Ensure we only visit each expression once. */
4193 : 6602 : cp_walk_tree_without_duplicates (&BIND_EXPR_BODY (*stmt),
4194 : : register_local_var_uses, d);
4195 : 6602 : *do_subtree = 0; /* We've done this. */
4196 : 6602 : lvd->nest_depth--;
4197 : 6602 : return NULL_TREE;
4198 : : }
4199 : :
4200 : : /* Build, return FUNCTION_DECL node based on ORIG with a type FN_TYPE which has
4201 : : a single argument of type CORO_FRAME_PTR. Build the actor function if
4202 : : ACTOR_P is true, otherwise the destroy. */
4203 : :
4204 : : static tree
4205 : 2696 : coro_build_actor_or_destroy_function (tree orig, tree fn_type,
4206 : : tree coro_frame_ptr, bool actor_p)
4207 : : {
4208 : 2696 : location_t loc = DECL_SOURCE_LOCATION (orig);
4209 : 2696 : tree fn
4210 : 2696 : = build_lang_decl (FUNCTION_DECL, copy_node (DECL_NAME (orig)), fn_type);
4211 : :
4212 : : /* Allow for locating the ramp (original) function from this one. */
4213 : 2696 : if (!to_ramp)
4214 : 1167 : to_ramp = hash_map<tree, tree>::create_ggc (10);
4215 : 2696 : to_ramp->put (fn, orig);
4216 : :
4217 : 2696 : DECL_CONTEXT (fn) = DECL_CONTEXT (orig);
4218 : 2696 : DECL_SOURCE_LOCATION (fn) = loc;
4219 : 2696 : DECL_ARTIFICIAL (fn) = true;
4220 : 2696 : DECL_INITIAL (fn) = error_mark_node;
4221 : :
4222 : 2696 : tree id = get_identifier ("frame_ptr");
4223 : 2696 : tree fp = build_lang_decl (PARM_DECL, id, coro_frame_ptr);
4224 : 2696 : DECL_ARTIFICIAL (fp) = true;
4225 : 2696 : DECL_CONTEXT (fp) = fn;
4226 : 2696 : DECL_ARG_TYPE (fp) = type_passed_as (coro_frame_ptr);
4227 : 2696 : DECL_ARGUMENTS (fn) = fp;
4228 : :
4229 : : /* Copy selected attributes from the original function. */
4230 : 2696 : TREE_USED (fn) = TREE_USED (orig);
4231 : 2696 : if (DECL_SECTION_NAME (orig))
4232 : 0 : set_decl_section_name (fn, orig);
4233 : : /* Copy any alignment that the FE added. */
4234 : 2696 : if (DECL_ALIGN (orig))
4235 : 2696 : SET_DECL_ALIGN (fn, DECL_ALIGN (orig));
4236 : : /* Copy any alignment the user added. */
4237 : 2696 : DECL_USER_ALIGN (fn) = DECL_USER_ALIGN (orig);
4238 : : /* Apply attributes from the original fn. */
4239 : 2696 : DECL_ATTRIBUTES (fn) = copy_list (DECL_ATTRIBUTES (orig));
4240 : : /* but we do not want ones for contracts. */
4241 : 2696 : remove_contract_attributes (fn);
4242 : :
4243 : : /* A void return. */
4244 : 2696 : tree resdecl = build_decl (loc, RESULT_DECL, 0, void_type_node);
4245 : 2696 : DECL_CONTEXT (resdecl) = fn;
4246 : 2696 : DECL_ARTIFICIAL (resdecl) = 1;
4247 : 2696 : DECL_IGNORED_P (resdecl) = 1;
4248 : 2696 : DECL_RESULT (fn) = resdecl;
4249 : :
4250 : : /* Set up a means to find out if a decl is one of the helpers and, if so,
4251 : : which one. */
4252 : 2696 : if (coroutine_info *info = get_coroutine_info (orig))
4253 : : {
4254 : 2696 : gcc_checking_assert ((actor_p && info->actor_decl == NULL_TREE)
4255 : : || info->destroy_decl == NULL_TREE);
4256 : 2696 : if (actor_p)
4257 : 1348 : info->actor_decl = fn;
4258 : : else
4259 : 1348 : info->destroy_decl = fn;
4260 : : }
4261 : 2696 : return fn;
4262 : : }
4263 : :
4264 : : /* Re-write the body as per [dcl.fct.def.coroutine] / 5. */
4265 : :
4266 : : void
4267 : 1348 : cp_coroutine_transform::wrap_original_function_body ()
4268 : : {
4269 : : /* Avoid the code here attaching a location that makes the debugger jump. */
4270 : 1348 : iloc_sentinel stable_input_loc (fn_start);
4271 : 1348 : location_t loc = UNKNOWN_LOCATION;
4272 : 1348 : input_location = loc;
4273 : :
4274 : : /* This will be our new outer scope. */
4275 : 1348 : tree update_body
4276 : 1348 : = build3_loc (loc, BIND_EXPR, void_type_node, NULL, NULL, NULL);
4277 : 1348 : tree top_block = make_node (BLOCK);
4278 : 1348 : BIND_EXPR_BLOCK (update_body) = top_block;
4279 : 1348 : BIND_EXPR_BODY (update_body) = push_stmt_list ();
4280 : :
4281 : : /* If the function has a top level bind expression, then connect that
4282 : : after first making sure we give it a new block. */
4283 : 1348 : tree first = expr_first (coroutine_body);
4284 : 1348 : if (first && TREE_CODE (first) == BIND_EXPR)
4285 : : {
4286 : 579 : tree block = BIND_EXPR_BLOCK (first);
4287 : 579 : gcc_checking_assert (block);
4288 : 579 : gcc_checking_assert (BLOCK_SUPERCONTEXT (block) == NULL_TREE);
4289 : 579 : gcc_checking_assert (BLOCK_CHAIN (block) == NULL_TREE);
4290 : : /* Replace the top block to avoid issues with locations for args
4291 : : appearing to be in a non-existent place. */
4292 : 579 : tree replace_blk = make_node (BLOCK);
4293 : 579 : BLOCK_VARS (replace_blk) = BLOCK_VARS (block);
4294 : 579 : BLOCK_SUBBLOCKS (replace_blk) = BLOCK_SUBBLOCKS (block);
4295 : 815 : for (tree b = BLOCK_SUBBLOCKS (replace_blk); b; b = BLOCK_CHAIN (b))
4296 : 236 : BLOCK_SUPERCONTEXT (b) = replace_blk;
4297 : 579 : BIND_EXPR_BLOCK (first) = replace_blk;
4298 : : /* The top block has one child, so far, and we have now got a
4299 : : superblock. */
4300 : 579 : BLOCK_SUPERCONTEXT (replace_blk) = top_block;
4301 : 579 : BLOCK_SUBBLOCKS (top_block) = replace_blk;
4302 : 579 : }
4303 : : else
4304 : : {
4305 : : /* We are missing a top level BIND_EXPR. We need one to ensure that we
4306 : : don't shuffle around the coroutine frame and corrupt it. */
4307 : 769 : tree bind_wrap = build3_loc (loc, BIND_EXPR, void_type_node,
4308 : : NULL, NULL, NULL);
4309 : 769 : BIND_EXPR_BODY (bind_wrap) = coroutine_body;
4310 : : /* Ensure we have a block to connect up the scopes. */
4311 : 769 : tree new_blk = make_node (BLOCK);
4312 : 769 : BIND_EXPR_BLOCK (bind_wrap) = new_blk;
4313 : 769 : BLOCK_SUBBLOCKS (top_block) = new_blk;
4314 : 769 : coroutine_body = bind_wrap;
4315 : : }
4316 : :
4317 : : /* Wrap the function body in a try {} catch (...) {} block, if exceptions
4318 : : are enabled. */
4319 : 1348 : tree var_list = NULL_TREE;
4320 : 1348 : tree initial_await = build_init_or_final_await (fn_start, false);
4321 : :
4322 : : /* [stmt.return.coroutine] / 3
4323 : : If p.return_void() is a valid expression, flowing off the end of a
4324 : : coroutine is equivalent to a co_return with no operand; otherwise
4325 : : flowing off the end of a coroutine results in undefined behavior. */
4326 : 1348 : tree return_void
4327 : 1348 : = get_coroutine_return_void_expr (orig_fn_decl, loc, false);
4328 : :
4329 : : /* The pointer to the resume function. */
4330 : 1348 : tree resume_fn_ptr
4331 : 1348 : = coro_build_artificial_var (loc, coro_resume_fn_id,
4332 : : act_des_fn_ptr_type, orig_fn_decl, NULL_TREE);
4333 : 1348 : DECL_CHAIN (resume_fn_ptr) = var_list;
4334 : 1348 : var_list = resume_fn_ptr;
4335 : 1348 : add_decl_expr (resume_fn_ptr);
4336 : :
4337 : : /* We will need to be able to set the resume function pointer to nullptr
4338 : : to signal that the coroutine is 'done'. */
4339 : 1348 : tree zero_resume
4340 : 1348 : = build1 (CONVERT_EXPR, act_des_fn_ptr_type, nullptr_node);
4341 : :
4342 : : /* The pointer to the destroy function. */
4343 : 1348 : tree var
4344 : 1348 : = coro_build_artificial_var (loc, coro_destroy_fn_id,
4345 : : act_des_fn_ptr_type, orig_fn_decl, NULL_TREE);
4346 : 1348 : DECL_CHAIN (var) = var_list;
4347 : 1348 : var_list = var;
4348 : 1348 : add_decl_expr (var);
4349 : :
4350 : : /* The promise was created on demand when parsing we now link it into
4351 : : our scope. */
4352 : 1348 : tree promise = get_coroutine_promise_proxy (orig_fn_decl);
4353 : 1348 : DECL_CONTEXT (promise) = orig_fn_decl;
4354 : 1348 : DECL_SOURCE_LOCATION (promise) = loc;
4355 : 1348 : DECL_CHAIN (promise) = var_list;
4356 : 1348 : var_list = promise;
4357 : 1348 : add_decl_expr (promise);
4358 : :
4359 : : /* We need a handle to this coroutine, which is passed to every
4360 : : await_suspend(). This was created on demand when parsing we now link it
4361 : : into our scope. */
4362 : 1348 : var = get_coroutine_self_handle_proxy (orig_fn_decl);
4363 : 1348 : DECL_CONTEXT (var) = orig_fn_decl;
4364 : 1348 : DECL_SOURCE_LOCATION (var) = loc;
4365 : 1348 : DECL_CHAIN (var) = var_list;
4366 : 1348 : var_list = var;
4367 : 1348 : add_decl_expr (var);
4368 : :
4369 : : /* If we have function parms, then these will be copied to the coroutine
4370 : : frame as per [dcl.fct.def.coroutine] / 13.
4371 : : Here, we create a local (proxy) variable for each parm, since the original
4372 : : parms will be out of scope once the ramp has finished. The proxy vars will
4373 : : get DECL_VALUE_EXPRs pointing to the frame copies, so that we can interact
4374 : : with them in the debugger. */
4375 : 1348 : if (DECL_ARGUMENTS (orig_fn_decl))
4376 : : {
4377 : : /* Add a local var for each parm. */
4378 : 1561 : for (tree arg = DECL_ARGUMENTS (orig_fn_decl); arg != NULL;
4379 : 883 : arg = DECL_CHAIN (arg))
4380 : : {
4381 : 883 : param_info *parm_i = param_uses.get (arg);
4382 : 883 : gcc_checking_assert (parm_i);
4383 : 883 : parm_i->copy_var
4384 : 883 : = build_lang_decl (VAR_DECL, parm_i->field_id, TREE_TYPE (arg));
4385 : 883 : DECL_SOURCE_LOCATION (parm_i->copy_var) = DECL_SOURCE_LOCATION (arg);
4386 : 883 : DECL_CONTEXT (parm_i->copy_var) = orig_fn_decl;
4387 : 883 : DECL_ARTIFICIAL (parm_i->copy_var) = true;
4388 : 883 : DECL_CHAIN (parm_i->copy_var) = var_list;
4389 : 883 : var_list = parm_i->copy_var;
4390 : 883 : add_decl_expr (parm_i->copy_var);
4391 : : }
4392 : :
4393 : : /* Now replace all uses of the parms in the function body with the proxy
4394 : : vars. We want to this to apply to every instance of param's use, so
4395 : : don't include a 'visited' hash_set on the tree walk, however we will
4396 : : arrange to visit each containing expression only once. */
4397 : 678 : hash_set<tree *> visited;
4398 : 678 : param_frame_data param_data = {NULL, ¶m_uses,
4399 : 678 : &visited, loc, false};
4400 : 678 : cp_walk_tree (&coroutine_body, rewrite_param_uses, ¶m_data, NULL);
4401 : 678 : }
4402 : :
4403 : : /* We create a resume index, this is initialized in the ramp. */
4404 : 1348 : resume_idx_var
4405 : 1348 : = coro_build_artificial_var (loc, coro_resume_index_id,
4406 : : short_unsigned_type_node, orig_fn_decl,
4407 : : NULL_TREE);
4408 : 1348 : DECL_CHAIN (resume_idx_var) = var_list;
4409 : 1348 : var_list = resume_idx_var;
4410 : 1348 : add_decl_expr (resume_idx_var);
4411 : :
4412 : : /* If the coroutine has a frame that needs to be freed, this will be set by
4413 : : the ramp. */
4414 : 1348 : var = coro_build_artificial_var (fn_start, coro_frame_needs_free_id,
4415 : : boolean_type_node, orig_fn_decl, NULL_TREE);
4416 : 1348 : DECL_CHAIN (var) = var_list;
4417 : 1348 : var_list = var;
4418 : 1348 : add_decl_expr (var);
4419 : :
4420 : 1348 : if (flag_exceptions)
4421 : : {
4422 : : /* Build promise.unhandled_exception(); */
4423 : 1341 : tree ueh
4424 : 1341 : = coro_build_promise_expression (orig_fn_decl, promise,
4425 : : coro_unhandled_exception_identifier,
4426 : : fn_start, NULL, /*musthave=*/true);
4427 : : /* Create and initialize the initial-await-resume-called variable per
4428 : : [dcl.fct.def.coroutine] / 5.3. */
4429 : 1341 : tree i_a_r_c
4430 : 1341 : = coro_build_artificial_var (loc, coro_frame_i_a_r_c_id,
4431 : : boolean_type_node, orig_fn_decl,
4432 : : boolean_false_node);
4433 : 1341 : DECL_CHAIN (i_a_r_c) = var_list;
4434 : 1341 : var_list = i_a_r_c;
4435 : 1341 : add_decl_expr (i_a_r_c);
4436 : : /* Start the try-catch. */
4437 : 1341 : tree tcb = build_stmt (loc, TRY_BLOCK, NULL_TREE, NULL_TREE);
4438 : 1341 : add_stmt (tcb);
4439 : 1341 : TRY_STMTS (tcb) = push_stmt_list ();
4440 : 1341 : if (initial_await != error_mark_node)
4441 : : {
4442 : : /* Build a compound expression that sets the
4443 : : initial-await-resume-called variable true and then calls the
4444 : : initial suspend expression await resume.
4445 : : In the case that the user decides to make the initial await
4446 : : await_resume() return a value, we need to discard it and, it is
4447 : : a reference type, look past the indirection. */
4448 : 1339 : if (INDIRECT_REF_P (initial_await))
4449 : 1 : initial_await = TREE_OPERAND (initial_await, 0);
4450 : : /* In the case that the initial_await returns a target expression
4451 : : we might need to look through that to update the await expr. */
4452 : 1339 : tree iaw = initial_await;
4453 : 1339 : if (TREE_CODE (iaw) == TARGET_EXPR)
4454 : 1 : iaw = TARGET_EXPR_INITIAL (iaw);
4455 : 1339 : gcc_checking_assert (TREE_CODE (iaw) == CO_AWAIT_EXPR);
4456 : 1339 : tree vec = TREE_OPERAND (iaw, 3);
4457 : 1339 : tree aw_r = TREE_VEC_ELT (vec, 2);
4458 : 1339 : aw_r = convert_to_void (aw_r, ICV_STATEMENT, tf_warning_or_error);
4459 : 1339 : tree update = build2 (MODIFY_EXPR, boolean_type_node, i_a_r_c,
4460 : : boolean_true_node);
4461 : 1339 : aw_r = cp_build_compound_expr (update, aw_r, tf_warning_or_error);
4462 : 1339 : TREE_VEC_ELT (vec, 2) = aw_r;
4463 : : }
4464 : : /* Add the initial await to the start of the user-authored function. */
4465 : 1341 : finish_expr_stmt (initial_await);
4466 : : /* Append the original function body. */
4467 : 1341 : add_stmt (coroutine_body);
4468 : 1341 : if (return_void)
4469 : 441 : add_stmt (return_void);
4470 : 1341 : TRY_STMTS (tcb) = pop_stmt_list (TRY_STMTS (tcb));
4471 : 1341 : TRY_HANDLERS (tcb) = push_stmt_list ();
4472 : : /* Mimic what the parser does for the catch. */
4473 : 1341 : tree handler = begin_handler ();
4474 : 1341 : finish_handler_parms (NULL_TREE, handler); /* catch (...) */
4475 : :
4476 : : /* Get the initial await resume called value. */
4477 : 1341 : tree not_iarc_if = begin_if_stmt ();
4478 : 1341 : tree not_iarc = build1_loc (loc, TRUTH_NOT_EXPR,
4479 : : boolean_type_node, i_a_r_c);
4480 : 1341 : finish_if_stmt_cond (not_iarc, not_iarc_if);
4481 : : /* If the initial await resume called value is false, rethrow... */
4482 : 1341 : tree rethrow = build_throw (loc, NULL_TREE, tf_warning_or_error);
4483 : 1341 : suppress_warning (rethrow);
4484 : 1341 : finish_expr_stmt (rethrow);
4485 : 1341 : finish_then_clause (not_iarc_if);
4486 : 1341 : finish_if_stmt (not_iarc_if);
4487 : : /* ... else call the promise unhandled exception method
4488 : : but first we set done = true and the resume index to 0.
4489 : : If the unhandled exception method returns, then we continue
4490 : : to the final await expression (which duplicates the clearing of
4491 : : the field). */
4492 : 1341 : tree r = build2_loc (loc, MODIFY_EXPR, act_des_fn_ptr_type, resume_fn_ptr,
4493 : : zero_resume);
4494 : 1341 : finish_expr_stmt (r);
4495 : 1341 : tree short_zero = build_int_cst (short_unsigned_type_node, 0);
4496 : 1341 : r = build2 (MODIFY_EXPR, short_unsigned_type_node, resume_idx_var,
4497 : : short_zero);
4498 : 1341 : finish_expr_stmt (r);
4499 : 1341 : finish_expr_stmt (ueh);
4500 : 1341 : finish_handler (handler);
4501 : 1341 : TRY_HANDLERS (tcb) = pop_stmt_list (TRY_HANDLERS (tcb));
4502 : : }
4503 : : else
4504 : : {
4505 : 7 : if (pedantic)
4506 : : {
4507 : : /* We still try to look for the promise method and warn if it's not
4508 : : present. */
4509 : 5 : tree ueh_meth
4510 : 5 : = lookup_promise_method (orig_fn_decl,
4511 : : coro_unhandled_exception_identifier,
4512 : : fn_start, /*musthave=*/false);
4513 : 5 : if (!ueh_meth || ueh_meth == error_mark_node)
4514 : 2 : warning_at (fn_start, 0, "no member named %qE in %qT",
4515 : : coro_unhandled_exception_identifier,
4516 : : get_coroutine_promise_type (orig_fn_decl));
4517 : : }
4518 : : /* Else we don't check and don't care if the method is missing..
4519 : : just add the initial suspend, function and return. */
4520 : 7 : finish_expr_stmt (initial_await);
4521 : : /* Append the original function body. */
4522 : 7 : add_stmt (coroutine_body);
4523 : 7 : if (return_void)
4524 : 6 : add_stmt (return_void);
4525 : : }
4526 : :
4527 : : /* co_return branches to the final_suspend label, so declare that now. */
4528 : 1348 : fs_label
4529 : 1348 : = create_named_label_with_ctx (loc, "final.suspend", NULL_TREE);
4530 : 1348 : add_stmt (build_stmt (loc, LABEL_EXPR, fs_label));
4531 : :
4532 : : /* Before entering the final suspend point, we signal that this point has
4533 : : been reached by setting the resume function pointer to zero (this is
4534 : : what the 'done()' builtin tests) as per the current ABI. */
4535 : 1348 : zero_resume = build2_loc (loc, MODIFY_EXPR, act_des_fn_ptr_type,
4536 : : resume_fn_ptr, zero_resume);
4537 : 1348 : finish_expr_stmt (zero_resume);
4538 : 1348 : finish_expr_stmt (build_init_or_final_await (fn_start, true));
4539 : 1348 : BIND_EXPR_BODY (update_body) = pop_stmt_list (BIND_EXPR_BODY (update_body));
4540 : 1348 : BIND_EXPR_VARS (update_body) = nreverse (var_list);
4541 : 1348 : BLOCK_VARS (top_block) = BIND_EXPR_VARS (update_body);
4542 : :
4543 : 1348 : coroutine_body = update_body;
4544 : 1348 : }
4545 : :
4546 : : /* Extract the body of the function we are going to outline, leaving
4547 : : to original function decl ready to build the ramp. */
4548 : :
4549 : : static tree
4550 : 1369 : split_coroutine_body_from_ramp (tree fndecl)
4551 : : {
4552 : : /* Sanity-check and punt if we have a nonsense tree because of earlier
4553 : : parse errors, perhaps. */
4554 : 1369 : if (!current_binding_level
4555 : 1369 : || current_binding_level->kind != sk_function_parms)
4556 : : return NULL_TREE;
4557 : :
4558 : : /* Once we've tied off the original user-authored body in fn_body.
4559 : : Start the replacement synthesized ramp body. */
4560 : :
4561 : 1369 : tree body;
4562 : 1369 : if (use_eh_spec_block (fndecl))
4563 : : {
4564 : 390 : body = pop_stmt_list (TREE_OPERAND (current_eh_spec_block, 0));
4565 : 390 : TREE_OPERAND (current_eh_spec_block, 0) = push_stmt_list ();
4566 : : }
4567 : : else
4568 : : {
4569 : 979 : body = pop_stmt_list (DECL_SAVED_TREE (fndecl));
4570 : 979 : DECL_SAVED_TREE (fndecl) = push_stmt_list ();
4571 : : }
4572 : :
4573 : : /* We can't validly get here with an empty statement list, since there's no
4574 : : way for the FE to decide it's a coroutine in the absence of any code. */
4575 : 1369 : gcc_checking_assert (body != NULL_TREE);
4576 : :
4577 : : /* If we have an empty or erroneous function body, do not try to transform it
4578 : : since that would potentially wrap errors. */
4579 : 1369 : tree body_start = expr_first (body);
4580 : 1369 : if (body_start == NULL_TREE || body_start == error_mark_node)
4581 : : {
4582 : : /* Restore the original state. */
4583 : 21 : add_stmt (body);
4584 : 21 : return NULL_TREE;
4585 : : }
4586 : : return body;
4587 : : }
4588 : :
4589 : : /* Build the expression to allocate the coroutine frame according to the
4590 : : rules of [dcl.fct.def.coroutine] / 9. */
4591 : :
4592 : : static tree
4593 : 1347 : build_coroutine_frame_alloc_expr (tree promise_type, tree orig_fn_decl,
4594 : : location_t fn_start, tree grooaf,
4595 : : hash_map<tree, param_info> *param_uses,
4596 : : tree frame_size)
4597 : : {
4598 : : /* Allocate the frame, this has several possibilities:
4599 : : [dcl.fct.def.coroutine] / 9 (part 1)
4600 : : The allocation function’s name is looked up in the scope of the promise
4601 : : type. It is not a failure for it to be absent see part 4, below. */
4602 : :
4603 : 1347 : tree nwname = ovl_op_identifier (false, NEW_EXPR);
4604 : 1347 : tree new_fn_call = NULL_TREE;
4605 : 1347 : tree dummy_promise
4606 : 1347 : = build_dummy_object (get_coroutine_promise_type (orig_fn_decl));
4607 : :
4608 : 1347 : if (TYPE_HAS_NEW_OPERATOR (promise_type))
4609 : : {
4610 : 133 : tree fns = lookup_promise_method (orig_fn_decl, nwname, fn_start,
4611 : : /*musthave=*/true);
4612 : : /* [dcl.fct.def.coroutine] / 9 (part 2)
4613 : : If the lookup finds an allocation function in the scope of the promise
4614 : : type, overload resolution is performed on a function call created by
4615 : : assembling an argument list. The first argument is the amount of space
4616 : : requested, and has type std::size_t. The lvalues p1...pn are the
4617 : : succeeding arguments.. */
4618 : 133 : vec<tree, va_gc> *args = make_tree_vector ();
4619 : 133 : vec_safe_push (args, frame_size); /* Space needed. */
4620 : :
4621 : 229 : for (tree arg = DECL_ARGUMENTS (orig_fn_decl); arg != NULL;
4622 : 96 : arg = DECL_CHAIN (arg))
4623 : : {
4624 : 96 : param_info *parm_i = param_uses->get (arg);
4625 : 96 : gcc_checking_assert (parm_i);
4626 : 96 : if (parm_i->this_ptr || parm_i->lambda_cobj)
4627 : : {
4628 : : /* We pass a reference to *this to the allocator lookup. */
4629 : : /* It's unsafe to use the cp_ version here since current_class_ref
4630 : : might've gotten clobbered earlier during rewrite_param_uses. */
4631 : 4 : tree this_ref = build_fold_indirect_ref (arg);
4632 : 4 : vec_safe_push (args, this_ref);
4633 : 4 : }
4634 : : else
4635 : 92 : vec_safe_push (args, convert_from_reference (arg));
4636 : : }
4637 : :
4638 : : /* Note the function selected; we test to see if it's NOTHROW. */
4639 : 133 : tree func;
4640 : : /* Failure is not an error for this attempt. */
4641 : 133 : new_fn_call = build_new_method_call (dummy_promise, fns, &args, NULL,
4642 : : LOOKUP_NORMAL, &func, tf_none);
4643 : 133 : release_tree_vector (args);
4644 : :
4645 : 133 : if (new_fn_call == error_mark_node)
4646 : : {
4647 : : /* [dcl.fct.def.coroutine] / 9 (part 3)
4648 : : If no viable function is found, overload resolution is performed
4649 : : again on a function call created by passing just the amount of
4650 : : space required as an argument of type std::size_t. */
4651 : 51 : args = make_tree_vector_single (frame_size); /* Space needed. */
4652 : 51 : new_fn_call = build_new_method_call (dummy_promise, fns, &args,
4653 : : NULL_TREE, LOOKUP_NORMAL, &func,
4654 : : tf_none);
4655 : 51 : release_tree_vector (args);
4656 : : }
4657 : :
4658 : : /* However, if the promise provides an operator new, then one of these
4659 : : two options must be available. */
4660 : 133 : if (new_fn_call == error_mark_node)
4661 : : {
4662 : 1 : error_at (fn_start, "%qE is provided by %qT but is not usable with"
4663 : : " the function signature %qD", nwname, promise_type,
4664 : : orig_fn_decl);
4665 : 2 : return error_mark_node;
4666 : : }
4667 : 132 : else if (grooaf && !TYPE_NOTHROW_P (TREE_TYPE (func)))
4668 : : {
4669 : 1 : error_at (fn_start, "%qE is provided by %qT but %qE is not marked"
4670 : : " %<throw()%> or %<noexcept%>", grooaf, promise_type, nwname);
4671 : 1 : return error_mark_node;
4672 : : }
4673 : 131 : else if (!grooaf && TYPE_NOTHROW_P (TREE_TYPE (func)))
4674 : 1 : warning_at (fn_start, 0, "%qE is marked %<throw()%> or %<noexcept%> but"
4675 : : " no usable %<get_return_object_on_allocation_failure%>"
4676 : : " is provided by %qT", nwname, promise_type);
4677 : : }
4678 : : else /* No operator new in the promise. */
4679 : : {
4680 : : /* [dcl.fct.def.coroutine] / 9 (part 4)
4681 : : If this lookup fails, the allocation function’s name is looked up in
4682 : : the global scope. */
4683 : :
4684 : 1214 : vec<tree, va_gc> *args;
4685 : : /* build_operator_new_call () will insert size needed as element 0 of
4686 : : this, and we might need to append the std::nothrow constant. */
4687 : 1214 : vec_alloc (args, 2);
4688 : 1214 : if (grooaf)
4689 : : {
4690 : : /* [dcl.fct.def.coroutine] / 10 (part 2)
4691 : : If any declarations (of the get return on allocation fail) are
4692 : : found, then the result of a call to an allocation function used
4693 : : to obtain storage for the coroutine state is assumed to return
4694 : : nullptr if it fails to obtain storage and, if a global allocation
4695 : : function is selected, the ::operator new(size_t, nothrow_t) form
4696 : : is used. The allocation function used in this case shall have a
4697 : : non-throwing noexcept-specification. So we need std::nothrow. */
4698 : 10 : tree std_nt = lookup_qualified_name (std_node,
4699 : : get_identifier ("nothrow"),
4700 : : LOOK_want::NORMAL,
4701 : 10 : /*complain=*/true);
4702 : 10 : if (!std_nt || std_nt == error_mark_node)
4703 : : {
4704 : : /* Something is seriously wrong, punt. */
4705 : 1 : error_at (fn_start, "%qE is provided by %qT but %<std::nothrow%>"
4706 : : " cannot be found", grooaf, promise_type);
4707 : 1 : return error_mark_node;
4708 : : }
4709 : 9 : vec_safe_push (args, std_nt);
4710 : : }
4711 : :
4712 : : /* If we get to this point, we must succeed in looking up the global
4713 : : operator new for the params provided. Since we are not setting
4714 : : size_check or cookie, we expect frame_size to be unaltered. */
4715 : 1213 : tree cookie = NULL;
4716 : 1213 : new_fn_call = build_operator_new_call (nwname, &args, &frame_size,
4717 : : &cookie, /*align_arg=*/NULL,
4718 : : /*size_check=*/NULL, /*fn=*/NULL,
4719 : : tf_warning_or_error);
4720 : 1213 : release_tree_vector (args);
4721 : : }
4722 : : return new_fn_call;
4723 : : }
4724 : :
4725 : : /* Build an expression to delete the coroutine state frame. */
4726 : :
4727 : : static tree
4728 : 2682 : build_coroutine_frame_delete_expr (tree coro_fp, tree frame_size,
4729 : : tree promise_type, location_t loc)
4730 : : {
4731 : : /* Cast the frame pointer to a pointer to promise so that the build op
4732 : : delete call will search the promise. */
4733 : 2682 : tree pptr_type = build_pointer_type (promise_type);
4734 : 2682 : tree frame_arg = build1_loc (loc, CONVERT_EXPR, pptr_type, coro_fp);
4735 : : /* [dcl.fct.def.coroutine] / 12 sentence 3:
4736 : : If both a usual deallocation function with only a pointer parameter and
4737 : : a usual deallocation function with both a pointer parameter and a size
4738 : : parameter are found, then the selected deallocation function shall be the
4739 : : one with two parameters. */
4740 : 2682 : tree del_coro_fr
4741 : 2682 : = build_coroutine_op_delete_call (DELETE_EXPR, frame_arg, frame_size,
4742 : : /*global_p=*/false, /*placement=*/NULL,
4743 : : /*alloc_fn=*/NULL, tf_warning_or_error);
4744 : 2682 : if (!del_coro_fr || del_coro_fr == error_mark_node)
4745 : 1 : return error_mark_node;
4746 : : return del_coro_fr;
4747 : : }
4748 : :
4749 : : /* Build the ramp function.
4750 : : Here we take the original function definition which has now had its body
4751 : : removed, and use it as the declaration of the ramp which both replaces the
4752 : : user's written function at call sites, and is responsible for starting
4753 : : the coroutine it defined.
4754 : : returns false on error.
4755 : :
4756 : : We should arrive here with the state of the compiler as if we had just
4757 : : executed start_preparsed_function(). */
4758 : :
4759 : : bool
4760 : 1348 : cp_coroutine_transform::build_ramp_function ()
4761 : : {
4762 : 1348 : gcc_checking_assert (current_binding_level
4763 : : && current_binding_level->kind == sk_function_parms);
4764 : :
4765 : : /* This is completely synthetic code, if we find an issue then we have not
4766 : : much chance to point at the most useful place in the user's code. In
4767 : : lieu of this use the function start - so at least the diagnostic relates
4768 : : to something that the user can inspect. */
4769 : 1348 : iloc_sentinel saved_position (fn_start);
4770 : 1348 : location_t loc = fn_start;
4771 : :
4772 : 1348 : tree promise_type = get_coroutine_promise_type (orig_fn_decl);
4773 : 1348 : tree fn_return_type = TREE_TYPE (TREE_TYPE (orig_fn_decl));
4774 : 1348 : bool void_ramp_p = VOID_TYPE_P (fn_return_type);
4775 : : /* We know there was no return statement, that is intentional. */
4776 : 1348 : suppress_warning (orig_fn_decl, OPT_Wreturn_type);
4777 : :
4778 : : /* [dcl.fct.def.coroutine] / 10 (part1)
4779 : : The unqualified-id get_return_object_on_allocation_failure is looked up
4780 : : in the scope of the promise type by class member access lookup. */
4781 : :
4782 : : /* We don't require this, but, if the lookup succeeds, then the function
4783 : : must be usable, punt if it is not. */
4784 : 1348 : tree grooaf_meth
4785 : 1348 : = lookup_promise_method (orig_fn_decl,
4786 : : coro_gro_on_allocation_fail_identifier, loc,
4787 : : /*musthave*/ false);
4788 : 1348 : tree grooaf = NULL_TREE;
4789 : 1348 : tree dummy_promise
4790 : 2696 : = build_dummy_object (get_coroutine_promise_type (orig_fn_decl));
4791 : 1348 : if (grooaf_meth && grooaf_meth != error_mark_node)
4792 : : {
4793 : 30 : grooaf
4794 : 30 : = coro_build_promise_expression (orig_fn_decl, dummy_promise,
4795 : : coro_gro_on_allocation_fail_identifier,
4796 : : fn_start, NULL, /*musthave=*/false);
4797 : :
4798 : : /* That should succeed. */
4799 : 30 : if (!grooaf || grooaf == error_mark_node)
4800 : : {
4801 : 1 : error_at (fn_start, "%qE is provided by %qT but is not usable with"
4802 : : " the function %qD", coro_gro_on_allocation_fail_identifier,
4803 : : promise_type, orig_fn_decl);
4804 : 1 : return false;
4805 : : }
4806 : : }
4807 : :
4808 : : /* Check early for usable allocator/deallocator, without which we cannot
4809 : : build a useful ramp; early exit if they are not available or usable. */
4810 : :
4811 : 1347 : frame_size = TYPE_SIZE_UNIT (frame_type);
4812 : :
4813 : : /* Make a var to represent the frame pointer early. */
4814 : 1347 : tree coro_fp = coro_build_artificial_var (loc, "_Coro_frameptr",
4815 : : frame_ptr_type, orig_fn_decl,
4816 : : NULL_TREE);
4817 : :
4818 : 1347 : tree new_fn_call
4819 : 1347 : = build_coroutine_frame_alloc_expr (promise_type, orig_fn_decl, fn_start,
4820 : : grooaf, ¶m_uses, frame_size);
4821 : :
4822 : : /* We must have a useable allocator to proceed. */
4823 : 1347 : if (!new_fn_call || new_fn_call == error_mark_node)
4824 : : return false;
4825 : :
4826 : : /* Likewise, we need the DTOR to delete the frame. */
4827 : 1344 : tree delete_frame_call
4828 : 1344 : = build_coroutine_frame_delete_expr (coro_fp, frame_size, promise_type,
4829 : : fn_start);
4830 : 1344 : if (!delete_frame_call || delete_frame_call == error_mark_node)
4831 : : return false;
4832 : :
4833 : : /* At least verify we can lookup the get return object method. */
4834 : 1343 : tree get_ro_meth
4835 : 1343 : = lookup_promise_method (orig_fn_decl,
4836 : : coro_get_return_object_identifier, loc,
4837 : : /*musthave*/ true);
4838 : 1343 : if (!get_ro_meth || get_ro_meth == error_mark_node)
4839 : : return false;
4840 : :
4841 : : /* So now construct the Ramp: */
4842 : :
4843 : 1342 : tree ramp_fnbody = begin_compound_stmt (BCS_FN_BODY);
4844 : 1342 : coro_fp = pushdecl (coro_fp);
4845 : 1342 : add_decl_expr (coro_fp);
4846 : :
4847 : 1342 : tree coro_promise_live = NULL_TREE;
4848 : 1342 : tree coro_gro_live = NULL_TREE;
4849 : 1342 : if (flag_exceptions)
4850 : : {
4851 : : /* Signal that we need to clean up the promise object on exception. */
4852 : 1335 : coro_promise_live
4853 : 1335 : = coro_build_and_push_artificial_var (loc, "_Coro_promise_live",
4854 : : boolean_type_node, orig_fn_decl,
4855 : : boolean_false_node);
4856 : :
4857 : : /* When the get-return-object is in the RETURN slot, we need to arrange
4858 : : for cleanup on exception. */
4859 : 1335 : coro_gro_live
4860 : 1335 : = coro_build_and_push_artificial_var (loc, "_Coro_gro_live",
4861 : : boolean_type_node, orig_fn_decl,
4862 : : boolean_false_node);
4863 : :
4864 : : /* To signal that we need to cleanup copied function args. */
4865 : 1335 : if (DECL_ARGUMENTS (orig_fn_decl))
4866 : 1559 : for (tree arg = DECL_ARGUMENTS (orig_fn_decl); arg != NULL;
4867 : 882 : arg = DECL_CHAIN (arg))
4868 : : {
4869 : 882 : param_info *parm_i = param_uses.get (arg);
4870 : 882 : if (parm_i->trivial_dtor)
4871 : 802 : continue;
4872 : 80 : parm_i->guard_var = pushdecl (parm_i->guard_var);
4873 : 80 : add_decl_expr (parm_i->guard_var);
4874 : : }
4875 : : }
4876 : :
4877 : : /* deref the frame pointer, to use in member access code. */
4878 : 1342 : tree deref_fp
4879 : 1342 : = cp_build_indirect_ref (loc, coro_fp, RO_UNARY_STAR,
4880 : : tf_warning_or_error);
4881 : 1342 : tree frame_needs_free
4882 : 1342 : = coro_build_and_push_artificial_var_with_dve (loc,
4883 : : coro_frame_needs_free_id,
4884 : : boolean_type_node,
4885 : : orig_fn_decl, NULL_TREE,
4886 : : deref_fp);
4887 : :
4888 : : /* Build the frame. */
4889 : :
4890 : : /* The CO_FRAME internal function is a mechanism to allow the middle end
4891 : : to adjust the allocation in response to optimizations. We provide the
4892 : : current conservative estimate of the frame size (as per the current)
4893 : : computed layout. */
4894 : :
4895 : 1342 : tree resizeable
4896 : 1342 : = build_call_expr_internal_loc (loc, IFN_CO_FRAME, size_type_node, 2,
4897 : : frame_size,
4898 : : build_zero_cst (frame_ptr_type));
4899 : 1342 : CALL_EXPR_ARG (new_fn_call, 0) = resizeable;
4900 : 1342 : tree allocated = build1 (CONVERT_EXPR, frame_ptr_type, new_fn_call);
4901 : 1342 : tree r = cp_build_init_expr (coro_fp, allocated);
4902 : 1342 : finish_expr_stmt (r);
4903 : :
4904 : : /* If the user provided a method to return an object on alloc fail, then
4905 : : check the returned pointer and call the func if it's null.
4906 : : Otherwise, no check, and we fail for noexcept/fno-exceptions cases. */
4907 : :
4908 : 1342 : if (grooaf)
4909 : : {
4910 : : /* [dcl.fct.def.coroutine] / 10 (part 3)
4911 : : If the allocation function returns nullptr,the coroutine returns
4912 : : control to the caller of the coroutine and the return value is
4913 : : obtained by a call to T::get_return_object_on_allocation_failure(),
4914 : : where T is the promise type. */
4915 : 27 : tree if_stmt = begin_if_stmt ();
4916 : 27 : tree cond = build1 (CONVERT_EXPR, frame_ptr_type, nullptr_node);
4917 : 27 : cond = build2 (EQ_EXPR, boolean_type_node, coro_fp, cond);
4918 : 27 : finish_if_stmt_cond (cond, if_stmt);
4919 : 27 : r = NULL_TREE;
4920 : 27 : if (void_ramp_p)
4921 : : /* Execute the get-return-object-on-alloc-fail call... */
4922 : 0 : finish_expr_stmt (grooaf);
4923 : : else
4924 : : /* Get the fallback return object. */
4925 : : r = grooaf;
4926 : 27 : finish_return_stmt (r);
4927 : 27 : finish_then_clause (if_stmt);
4928 : 27 : finish_if_stmt (if_stmt);
4929 : : }
4930 : :
4931 : : /* For now, once allocation has succeeded we always assume that this needs
4932 : : destruction, there's no impl. for frame allocation elision. */
4933 : 1342 : r = cp_build_init_expr (frame_needs_free, boolean_true_node);
4934 : 1342 : finish_expr_stmt (r);
4935 : :
4936 : : /* Set up the promise. */
4937 : 1342 : tree p
4938 : 1342 : = coro_build_and_push_artificial_var_with_dve (loc, coro_promise_id,
4939 : : promise_type, orig_fn_decl,
4940 : : NULL_TREE, deref_fp);
4941 : :
4942 : : /* Up to now any exception thrown will propagate directly to the caller.
4943 : : This is OK since the only source of such exceptions would be in allocation
4944 : : of the coroutine frame, and therefore the ramp will not have initialized
4945 : : any further state. From here, we will track state that needs explicit
4946 : : destruction in the case that promise or g.r.o setup fails or an exception
4947 : : is thrown from the initial suspend expression. */
4948 : 1342 : tree ramp_try_block = NULL_TREE;
4949 : 1342 : tree ramp_try_stmts = NULL_TREE;
4950 : 1342 : tree iarc_x = NULL_TREE;
4951 : 1342 : if (flag_exceptions)
4952 : : {
4953 : 1335 : iarc_x
4954 : 1335 : = coro_build_and_push_artificial_var_with_dve (loc,
4955 : : coro_frame_i_a_r_c_id,
4956 : : boolean_type_node,
4957 : : orig_fn_decl, NULL_TREE,
4958 : : deref_fp);
4959 : 1335 : ramp_try_block = begin_try_block ();
4960 : 1335 : ramp_try_stmts = begin_compound_stmt (BCS_TRY_BLOCK);
4961 : : }
4962 : :
4963 : : /* Put the resumer and destroyer functions in. */
4964 : :
4965 : 1342 : tree actor_addr = build1 (ADDR_EXPR, act_des_fn_ptr_type, resumer);
4966 : 1342 : coro_build_and_push_artificial_var_with_dve (loc, coro_resume_fn_id,
4967 : : act_des_fn_ptr_type,
4968 : : orig_fn_decl,
4969 : : actor_addr, deref_fp);
4970 : :
4971 : 1342 : tree destroy_addr = build1 (ADDR_EXPR, act_des_fn_ptr_type, destroyer);
4972 : 1342 : coro_build_and_push_artificial_var_with_dve (loc, coro_destroy_fn_id,
4973 : : act_des_fn_ptr_type,
4974 : : orig_fn_decl,
4975 : : destroy_addr, deref_fp);
4976 : :
4977 : : /* [dcl.fct.def.coroutine] /13
4978 : : When a coroutine is invoked, a copy is created for each coroutine
4979 : : parameter. Each such copy is an object with automatic storage duration
4980 : : that is direct-initialized from an lvalue referring to the corresponding
4981 : : parameter if the parameter is an lvalue reference, and from an xvalue
4982 : : referring to it otherwise. A reference to a parameter in the function-
4983 : : body of the coroutine and in the call to the coroutine promise
4984 : : constructor is replaced by a reference to its copy. */
4985 : :
4986 : 1342 : vec<tree, va_gc> *promise_args = NULL; /* So that we can adjust refs. */
4987 : :
4988 : : /* The initialization and destruction of each parameter copy occurs in the
4989 : : context of the called coroutine. Initializations of parameter copies are
4990 : : sequenced before the call to the coroutine promise constructor and
4991 : : indeterminately sequenced with respect to each other. The lifetime of
4992 : : parameter copies ends immediately after the lifetime of the coroutine
4993 : : promise object ends. */
4994 : :
4995 : 1342 : if (DECL_ARGUMENTS (orig_fn_decl))
4996 : : {
4997 : 678 : promise_args = make_tree_vector ();
4998 : 1561 : for (tree arg = DECL_ARGUMENTS (orig_fn_decl); arg != NULL;
4999 : 883 : arg = DECL_CHAIN (arg))
5000 : : {
5001 : 883 : bool existed;
5002 : 883 : param_info &parm = param_uses.get_or_insert (arg, &existed);
5003 : 883 : tree fld_idx
5004 : 883 : = coro_build_frame_access_expr (deref_fp, parm.field_id,
5005 : 883 : false, tf_warning_or_error);
5006 : :
5007 : : /* Add this to the promise CTOR arguments list, accounting for
5008 : : refs and special handling for method this ptr. */
5009 : 883 : if (parm.this_ptr || parm.lambda_cobj)
5010 : : {
5011 : : /* We pass a reference to *this to the param preview. */
5012 : : /* It's unsafe to use the cp_ version here since current_class_ref
5013 : : might've gotten clobbered earlier during rewrite_param_uses. */
5014 : 211 : tree this_ref = build_fold_indirect_ref (arg);
5015 : 211 : vec_safe_push (promise_args, this_ref);
5016 : 211 : }
5017 : 672 : else if (parm.rv_ref)
5018 : 32 : vec_safe_push (promise_args, move (fld_idx));
5019 : : else
5020 : 640 : vec_safe_push (promise_args, fld_idx);
5021 : :
5022 : 883 : if (parm.rv_ref || parm.pt_ref)
5023 : : /* Initialise the frame reference field directly. */
5024 : 112 : r = cp_build_modify_expr (loc, TREE_OPERAND (fld_idx, 0),
5025 : : INIT_EXPR, arg, tf_warning_or_error);
5026 : : else
5027 : : {
5028 : 771 : r = forward_parm (arg);
5029 : 771 : r = cp_build_modify_expr (loc, fld_idx, INIT_EXPR, r,
5030 : : tf_warning_or_error);
5031 : : }
5032 : 883 : finish_expr_stmt (r);
5033 : 883 : if (!parm.trivial_dtor)
5034 : : {
5035 : 81 : param_dtor_list.safe_push (parm.field_id);
5036 : : /* Cleanup this frame copy on exception. */
5037 : 81 : parm.fr_copy_dtor
5038 : 81 : = cxx_maybe_build_cleanup (fld_idx, tf_warning_or_error);
5039 : 81 : if (flag_exceptions)
5040 : : {
5041 : : /* This var is now live. */
5042 : 80 : r = build_modify_expr (loc, parm.guard_var,
5043 : : boolean_type_node, INIT_EXPR, loc,
5044 : : boolean_true_node, boolean_type_node);
5045 : 80 : finish_expr_stmt (r);
5046 : : }
5047 : : }
5048 : : }
5049 : : }
5050 : :
5051 : 1342 : if (type_build_ctor_call (promise_type))
5052 : : {
5053 : : /* Construct the promise object [dcl.fct.def.coroutine] / 5.7.
5054 : :
5055 : : First try to find a constructor with an argument list comprised of
5056 : : the parameter copies. */
5057 : :
5058 : 1031 : if (DECL_ARGUMENTS (orig_fn_decl))
5059 : : {
5060 : 601 : r = build_special_member_call (p, complete_ctor_identifier,
5061 : : &promise_args, promise_type,
5062 : : LOOKUP_NORMAL, tf_none);
5063 : 601 : release_tree_vector (promise_args);
5064 : : }
5065 : : else
5066 : : r = NULL_TREE;
5067 : :
5068 : : /* If that fails then the promise constructor argument list is empty. */
5069 : 601 : if (r == NULL_TREE || r == error_mark_node)
5070 : 751 : r = build_special_member_call (p, complete_ctor_identifier, NULL,
5071 : : promise_type, LOOKUP_NORMAL,
5072 : : tf_warning_or_error);
5073 : :
5074 : : /* If type_build_ctor_call() encounters deprecated implicit CTORs it will
5075 : : return true, and therefore we will execute this code path. However,
5076 : : we might well not actually require a CTOR and under those conditions
5077 : : the build call above will not return a call expression, but the
5078 : : original instance object. Do not attempt to add the statement unless
5079 : : it has side-effects. */
5080 : 1031 : if (r && r != error_mark_node && TREE_SIDE_EFFECTS (r))
5081 : 1023 : finish_expr_stmt (r);
5082 : : }
5083 : :
5084 : 1342 : tree promise_dtor = cxx_maybe_build_cleanup (p, tf_warning_or_error);;
5085 : 1342 : if (flag_exceptions && promise_dtor)
5086 : : {
5087 : 986 : r = cp_build_init_expr (coro_promise_live, boolean_true_node);
5088 : 986 : finish_expr_stmt (r);
5089 : : }
5090 : :
5091 : 1342 : tree get_ro
5092 : 1342 : = coro_build_promise_expression (orig_fn_decl, p,
5093 : : coro_get_return_object_identifier,
5094 : : fn_start, NULL, /*musthave=*/true);
5095 : :
5096 : : /* Without a return object we haven't got much clue what's going on. */
5097 : 1342 : if (!get_ro || get_ro == error_mark_node)
5098 : : return false;
5099 : :
5100 : : /* Check for a bad get return object type.
5101 : : [dcl.fct.def.coroutine] / 7 requires:
5102 : : The expression promise.get_return_object() is used to initialize the
5103 : : returned reference or prvalue result object ... */
5104 : 1342 : tree gro_type = TREE_TYPE (get_ro);
5105 : 1342 : if (VOID_TYPE_P (gro_type) && !void_ramp_p)
5106 : : {
5107 : 1 : error_at (fn_start, "no viable conversion from %<void%> provided by"
5108 : : " %<get_return_object%> to return type %qT", fn_return_type);
5109 : 1 : return false;
5110 : : }
5111 : :
5112 : : /* Initialize the resume_idx_var to 0, meaning "not started". */
5113 : 1341 : coro_build_and_push_artificial_var_with_dve
5114 : 1341 : (loc, coro_resume_index_id, short_unsigned_type_node, orig_fn_decl,
5115 : : build_zero_cst (short_unsigned_type_node), deref_fp);
5116 : :
5117 : 1341 : if (flag_exceptions && iarc_x)
5118 : : {
5119 : 1334 : r = cp_build_init_expr (iarc_x, boolean_false_node);
5120 : 1334 : finish_expr_stmt (r);
5121 : : }
5122 : :
5123 : : /* Used for return objects in the RESULT slot. */
5124 : 1341 : tree ret_val_dtor = NULL_TREE;
5125 : :
5126 : : /* [dcl.fct.def.coroutine] / 7
5127 : : The expression promise.get_return_object() is used to initialize the
5128 : : glvalue result or prvalue result object of a call to a coroutine. */
5129 : :
5130 : : /* We must manage the cleanups ourselves, because the responsibility for
5131 : : them changes after the initial suspend. However, any use of
5132 : : cxx_maybe_build_cleanup () can set the throwing_cleanup flag. */
5133 : 1341 : cp_function_chain->throwing_cleanup = false;
5134 : 1341 : if (void_ramp_p)
5135 : : /* We still want to call the method, even if the result is unused. */
5136 : : r = get_ro;
5137 : : else
5138 : : {
5139 : : /* The initial section of finish_return_expr (). */
5140 : 1325 : bool no_warning;
5141 : 1325 : bool dangling;
5142 : : /* Without a relevant location, bad conversions in check_return_expr
5143 : : result in unusable diagnostics, since there is not even a mention
5144 : : of the relevant function. Here we carry out the first part of
5145 : : finish_return_expr(). */
5146 : 1325 : input_location = fn_start;
5147 : 1325 : r = check_return_expr (get_ro, &no_warning, &dangling);
5148 : 1325 : input_location = UNKNOWN_LOCATION;
5149 : 1325 : gcc_checking_assert (!dangling);
5150 : : /* Check for bad things. */
5151 : 1325 : if (!r || r == error_mark_node)
5152 : 3 : return false;
5153 : : }
5154 : :
5155 : 1338 : finish_expr_stmt (r);
5156 : :
5157 : 1338 : if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (fn_return_type))
5158 : : /* If some part of the initalization code (prior to the await_resume
5159 : : of the initial suspend expression), then we need to clean up the
5160 : : return value. */
5161 : 1060 : ret_val_dtor = cxx_maybe_build_cleanup (DECL_RESULT (orig_fn_decl),
5162 : : tf_warning_or_error);
5163 : :
5164 : : /* If we have a live g.r.o in the return slot, then signal this for exception
5165 : : cleanup. */
5166 : 1338 : if (flag_exceptions && ret_val_dtor)
5167 : : {
5168 : 1060 : r = cp_build_init_expr (coro_gro_live, boolean_true_node);
5169 : 1060 : finish_expr_stmt (r);
5170 : : }
5171 : :
5172 : : /* Start the coroutine body. */
5173 : 1338 : r = build_call_expr_loc (fn_start, resumer, 1, coro_fp);
5174 : 1338 : finish_expr_stmt (r);
5175 : :
5176 : : /* The ramp is done, we just need the return statement, which we build from
5177 : : the return object we constructed before we called the actor. */
5178 : :
5179 : 1338 : r = void_ramp_p ? NULL_TREE : DECL_RESULT (orig_fn_decl);
5180 : :
5181 : : /* The reminder of finish_return_expr (). */
5182 : 1338 : r = build_stmt (loc, RETURN_EXPR, r);
5183 : 1338 : r = maybe_cleanup_point_expr_void (r);
5184 : 1338 : r = add_stmt (r);
5185 : :
5186 : 1338 : if (flag_exceptions)
5187 : : {
5188 : 1331 : finish_compound_stmt (ramp_try_stmts);
5189 : 1331 : finish_try_block (ramp_try_block);
5190 : 1331 : tree handler = begin_handler ();
5191 : 1331 : finish_handler_parms (NULL_TREE, handler); /* catch (...) */
5192 : :
5193 : : /* If we have a live G.R.O in the return slot, then run its DTOR. */
5194 : 1331 : if (ret_val_dtor && ret_val_dtor != error_mark_node)
5195 : : {
5196 : 1060 : tree gro_d_if = begin_if_stmt ();
5197 : 1060 : finish_if_stmt_cond (coro_gro_live, gro_d_if);
5198 : 1060 : finish_expr_stmt (ret_val_dtor);
5199 : 1060 : finish_then_clause (gro_d_if);
5200 : 1060 : finish_if_stmt (gro_d_if);
5201 : : }
5202 : :
5203 : : /* Before initial resume is called, the responsibility for cleanup on
5204 : : exception falls to the ramp. After that, the coroutine body code
5205 : : should do the cleanup. This is signalled by the flag
5206 : : 'initial_await_resume_called'. */
5207 : :
5208 : 1331 : tree not_iarc
5209 : 1331 : = build1_loc (loc, TRUTH_NOT_EXPR, boolean_type_node, iarc_x);
5210 : 1331 : tree cleanup_if = begin_if_stmt ();
5211 : 1331 : finish_if_stmt_cond (not_iarc, cleanup_if);
5212 : : /* If the promise is live, then run its dtor if that's available. */
5213 : 1331 : if (promise_dtor && promise_dtor != error_mark_node)
5214 : : {
5215 : 983 : tree promise_d_if = begin_if_stmt ();
5216 : 983 : finish_if_stmt_cond (coro_promise_live, promise_d_if);
5217 : 983 : finish_expr_stmt (promise_dtor);
5218 : 983 : finish_then_clause (promise_d_if);
5219 : 983 : finish_if_stmt (promise_d_if);
5220 : : }
5221 : :
5222 : : /* Clean up any frame copies of parms with non-trivial dtors.
5223 : : Do this in reverse order from their creation. */
5224 : 1331 : auto_vec<param_info *> worklist;
5225 : 1331 : if (DECL_ARGUMENTS (orig_fn_decl))
5226 : 1555 : for (tree arg = DECL_ARGUMENTS (orig_fn_decl); arg != NULL;
5227 : 880 : arg = DECL_CHAIN (arg))
5228 : : {
5229 : 880 : param_info *parm_i = param_uses.get (arg);
5230 : 880 : if (parm_i->trivial_dtor)
5231 : 800 : continue;
5232 : 80 : worklist.safe_push (parm_i);
5233 : : }
5234 : 1411 : while (!worklist.is_empty ())
5235 : : {
5236 : 80 : param_info *parm_i = worklist.pop ();
5237 : 80 : if (parm_i->fr_copy_dtor && parm_i->fr_copy_dtor != error_mark_node)
5238 : : {
5239 : 80 : tree dtor_if = begin_if_stmt ();
5240 : 80 : finish_if_stmt_cond (parm_i->guard_var, dtor_if);
5241 : 80 : finish_expr_stmt (parm_i->fr_copy_dtor);
5242 : 80 : finish_then_clause (dtor_if);
5243 : 80 : finish_if_stmt (dtor_if);
5244 : : }
5245 : : }
5246 : :
5247 : : /* No delete the frame if required. */
5248 : 1331 : tree fnf_if = begin_if_stmt ();
5249 : 1331 : finish_if_stmt_cond (frame_needs_free, fnf_if);
5250 : 1331 : finish_expr_stmt (delete_frame_call);
5251 : 1331 : finish_then_clause (fnf_if);
5252 : 1331 : finish_if_stmt (fnf_if);
5253 : :
5254 : : /* Finished cleanups conditional on "initial resume is not called". */
5255 : 1331 : finish_then_clause (cleanup_if);
5256 : 1331 : finish_if_stmt (cleanup_if);
5257 : :
5258 : 1331 : tree rethrow = build_throw (loc, NULL_TREE, tf_warning_or_error);
5259 : 1331 : suppress_warning (rethrow);
5260 : 1331 : finish_expr_stmt (rethrow);
5261 : 1331 : finish_handler (handler);
5262 : 1331 : finish_handler_sequence (ramp_try_block);
5263 : 1331 : }
5264 : 1338 : finish_compound_stmt (ramp_fnbody);
5265 : 1338 : return true;
5266 : 1348 : }
5267 : :
5268 : : /* ------- Encapsulate analysis of the couroutine -------- */
5269 : :
5270 : :
5271 : 1369 : cp_coroutine_transform::cp_coroutine_transform (tree _orig_fn, bool _inl)
5272 : 1369 : : orig_fn_decl (_orig_fn), inline_p (_inl)
5273 : : {
5274 : : /* We don't expect to be called with missing decl or e_m_n. */
5275 : 1369 : gcc_checking_assert (orig_fn_decl
5276 : : && TREE_CODE (orig_fn_decl) == FUNCTION_DECL);
5277 : 1369 : if (!coro_function_valid_p (orig_fn_decl))
5278 : : {
5279 : : /* For early errors, we do not want a diagnostic about the missing
5280 : : ramp return value, since the user cannot fix this - a 'return' is
5281 : : not allowed in a coroutine. */
5282 : 20 : suppress_warning (orig_fn_decl, OPT_Wreturn_type);
5283 : : /* Discard the body, we can't process it further... */
5284 : 20 : pop_stmt_list (DECL_SAVED_TREE (orig_fn_decl));
5285 : : /* ... and make an empty fn. */
5286 : 20 : DECL_SAVED_TREE (orig_fn_decl) = push_stmt_list ();
5287 : : /* Match the expected nesting when an eh block is in use. */
5288 : 20 : if (use_eh_spec_block (orig_fn_decl))
5289 : 0 : current_eh_spec_block = begin_eh_spec_block ();
5290 : 20 : valid_coroutine = false;
5291 : : }
5292 : :
5293 : : /* We don't have the locus of the opening brace - it's filled in later (and
5294 : : there doesn't really seem to be any easy way to get at it).
5295 : : The closing brace is assumed to be input_location. */
5296 : 1369 : fn_start = DECL_SOURCE_LOCATION (orig_fn_decl);
5297 : :
5298 : : /* Build types we need. */
5299 : 1369 : tree fr_name = get_fn_local_identifier (orig_fn_decl, "Frame");
5300 : 1369 : frame_type = xref_tag (record_type, fr_name);
5301 : 1369 : DECL_CONTEXT (TYPE_NAME (frame_type)) = DECL_CONTEXT (orig_fn_decl);
5302 : 1369 : frame_ptr_type = build_pointer_type (frame_type);
5303 : 1369 : act_des_fn_type
5304 : 1369 : = build_function_type_list (void_type_node, frame_ptr_type, NULL_TREE);
5305 : 1369 : act_des_fn_ptr_type = build_pointer_type (act_des_fn_type);
5306 : 1369 : valid_coroutine = true;
5307 : 1369 : }
5308 : :
5309 : 1369 : cp_coroutine_transform::~cp_coroutine_transform ()
5310 : : {
5311 : 1369 : }
5312 : :
5313 : : /* Here we:
5314 : : a) Check that the function and promise type are valid for a
5315 : : coroutine.
5316 : : b) Carry out the initial morph to create the skeleton of the
5317 : : coroutine ramp function and the rewritten body.
5318 : :
5319 : : Assumptions.
5320 : :
5321 : : 1. We only hit this code once all dependencies are resolved.
5322 : : 2. The function body will be either a bind expr or a statement list
5323 : : 3. That cfun and current_function_decl are valid for the case we're
5324 : : expanding.
5325 : : 4. 'input_location' will be of the final brace for the function.
5326 : :
5327 : : We do something like this:
5328 : : declare a dummy coro frame.
5329 : : struct _R_frame {
5330 : : using handle_type = coro::coroutine_handle<coro1::promise_type>;
5331 : : void (*_Coro_resume_fn)(_R_frame *);
5332 : : void (*_Coro_destroy_fn)(_R_frame *);
5333 : : coro1::promise_type _Coro_promise;
5334 : : bool _Coro_frame_needs_free; free the coro frame mem if set.
5335 : : bool _Coro_i_a_r_c; [dcl.fct.def.coroutine] / 5.3
5336 : : short _Coro_resume_index;
5337 : : handle_type _Coro_self_handle;
5338 : : parameter copies (were required).
5339 : : local variables saved (including awaitables)
5340 : : (maybe) trailing space.
5341 : : }; */
5342 : :
5343 : : void
5344 : 1369 : cp_coroutine_transform::apply_transforms ()
5345 : : {
5346 : 1369 : if (dmp_str == NULL)
5347 : 1369 : dmp_str = dump_begin (coro_dump_id, &coro_dump_flags);
5348 : :
5349 : 1369 : coro_maybe_dump_initial_function (orig_fn_decl);
5350 : :
5351 : 1369 : coroutine_body
5352 : 1369 : = split_coroutine_body_from_ramp (orig_fn_decl);
5353 : 1369 : if (!coroutine_body)
5354 : : {
5355 : 21 : valid_coroutine = false;
5356 : 21 : return;
5357 : : }
5358 : : /* Keep the original function block tree to one side and reset. */
5359 : 1348 : body_blocks = current_binding_level->blocks;
5360 : 1348 : current_binding_level->blocks = NULL_TREE;
5361 : :
5362 : : /* Collect information on the original function params and their use in the
5363 : : function body. */
5364 : 1348 : analyze_fn_parms (orig_fn_decl, ¶m_uses);
5365 : :
5366 : : /* Declare the actor and destroyer functions, the following code needs to
5367 : : see these. */
5368 : 1348 : resumer
5369 : 1348 : = coro_build_actor_or_destroy_function (orig_fn_decl, act_des_fn_type,
5370 : : frame_ptr_type, true);
5371 : 1348 : destroyer
5372 : 1348 : = coro_build_actor_or_destroy_function (orig_fn_decl, act_des_fn_type,
5373 : : frame_ptr_type, false);
5374 : :
5375 : : /* Transform the function body as per [dcl.fct.def.coroutine] / 5. */
5376 : 1348 : wrap_original_function_body ();
5377 : :
5378 : : /* Analyze the body await expressions. */
5379 : 1348 : susp_frame_data body_aw_points (fs_label, &suspend_points);
5380 : 1348 : cp_walk_tree (&coroutine_body, await_statement_walker, &body_aw_points, NULL);
5381 : 1348 : await_count = body_aw_points.await_number;
5382 : :
5383 : : /* Determine the fields for the coroutine state. */
5384 : 1348 : tree field_list = NULL_TREE;
5385 : 1348 : local_vars_frame_data local_vars_data (&field_list, &local_var_uses);
5386 : 1348 : cp_walk_tree_without_duplicates (&coroutine_body, register_local_var_uses,
5387 : : &local_vars_data);
5388 : :
5389 : : /* Conservative computation of the coroutine frame content. */
5390 : 1348 : frame_type = begin_class_definition (frame_type);
5391 : 1348 : TYPE_FIELDS (frame_type) = field_list;
5392 : 1348 : TYPE_BINFO (frame_type) = make_tree_binfo (0);
5393 : 1348 : BINFO_OFFSET (TYPE_BINFO (frame_type)) = size_zero_node;
5394 : 1348 : BINFO_TYPE (TYPE_BINFO (frame_type)) = frame_type;
5395 : 1348 : frame_type = finish_struct (frame_type, NULL_TREE);
5396 : :
5397 : 1348 : valid_coroutine = build_ramp_function ();
5398 : 1348 : coro_maybe_dump_ramp (orig_fn_decl);
5399 : : }
5400 : :
5401 : : /* Having analysed and collected the necessary data we are now in a position
5402 : : to build the outlined coroutine body and the destroyer shim. */
5403 : :
5404 : : void
5405 : 1338 : cp_coroutine_transform::finish_transforms ()
5406 : : {
5407 : 1338 : if (!valid_coroutine)
5408 : : return;
5409 : :
5410 : 1338 : current_function_decl = resumer;
5411 : 1338 : build_actor_fn (fn_start, frame_type, resumer, coroutine_body, orig_fn_decl,
5412 : : &local_var_uses, &suspend_points, ¶m_dtor_list,
5413 : 1338 : resume_idx_var, await_count, frame_size, inline_p);
5414 : :
5415 : 1338 : current_function_decl = destroyer;
5416 : 1338 : build_destroy_fn (fn_start, frame_type, destroyer, resumer, inline_p);
5417 : :
5418 : 1338 : coro_maybe_dump_transformed_functions (resumer, destroyer);
5419 : : }
5420 : :
5421 : : #include "gt-cp-coroutines.h"
5422 : :
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