Line data Source code
1 : /* C++ contracts.
2 :
3 : Copyright (C) 2020-2026 Free Software Foundation, Inc.
4 : Originally by Jeff Chapman II (jchapman@lock3software.com) for proposed
5 : C++20 contracts.
6 : Rewritten for C++26 contracts by:
7 : Nina Ranns (dinka.ranns@googlemail.com)
8 : Iain Sandoe (iain@sandoe.co.uk)
9 : Ville Voutilainen (ville.voutilainen@gmail.com).
10 :
11 : This file is part of GCC.
12 :
13 : GCC is free software; you can redistribute it and/or modify
14 : it under the terms of the GNU General Public License as published by
15 : the Free Software Foundation; either version 3, or (at your option)
16 : any later version.
17 :
18 : GCC is distributed in the hope that it will be useful,
19 : but WITHOUT ANY WARRANTY; without even the implied warranty of
20 : MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 : GNU General Public License for more details.
22 :
23 : You should have received a copy of the GNU General Public License
24 : along with GCC; see the file COPYING3. If not see
25 : <http://www.gnu.org/licenses/>. */
26 :
27 : #include "config.h"
28 : #include "system.h"
29 : #include "coretypes.h"
30 : #include "cp-tree.h"
31 : #include "stringpool.h"
32 : #include "diagnostic.h"
33 : #include "options.h"
34 : #include "contracts.h"
35 : #include "tree.h"
36 : #include "tree-inline.h"
37 : #include "attribs.h"
38 : #include "tree-iterator.h"
39 : #include "print-tree.h"
40 : #include "stor-layout.h"
41 : #include "intl.h"
42 : #include "cgraph.h"
43 : #include "opts.h"
44 : #include "output.h"
45 :
46 : /* Design notes.
47 :
48 : There are three phases:
49 : 1. Parsing and semantic checks.
50 : Most of the code for this is in the parser, with helpers provided here.
51 : 2. Emitting contract assertion AST nodes into function bodies.
52 : This is initiated from "finish_function ()"
53 : 3. Lowering the contract assertion AST nodes to control flow, constant
54 : data and calls to the violation handler.
55 : This is initiated from "cp_genericize ()".
56 :
57 : The organisation of the code in this file is intended to follow those three
58 : phases where possible.
59 :
60 : Contract Assertion State
61 : ========================
62 :
63 : contract_assert () does not require any special handling and can be
64 : represented directly by AST inserted in the function body.
65 :
66 : 'pre' and 'post' function contract specifiers require most of the special
67 : handling, since they must be tracked across re-declarations of functions and
68 : there are contraints on how such specifiers may change in these cases.
69 :
70 : The contracts specification identifies a "first declaration" of any given
71 : function - which is the first encountered when parsing a given TU.
72 : Subsequent re-declarations may not add or change the function contract
73 : specifiers from any introduced on this first declaration. It is, however,
74 : permitted to omit specifiers on re-declarations.
75 :
76 : Since the implementation of GCC's (re-)declarations is a destructive merge
77 : we need to keep some state on the side to determine whether the re-declaration
78 : rules are met. In this current design we have chosen not to add another tree
79 : to each function decl but, instead, keep a map from function decl to contract
80 : specifier state. In this state we record the 'first declaration' specifiers
81 : which are used to validate re-declaration(s) and to report the initial state
82 : in diagnostics.
83 :
84 : We need (for example) to compare
85 : pre ( x > 2 ) equal to
86 : pre ( z > 2 ) when x and z refer to the same function parameter in a
87 : re-declaration.
88 :
89 : The mechanism used to determine if two contracts are the same is to compare
90 : the folded trees. This makes use of current compiler machinery, rather than
91 : constructing some new AST comparison scheme. However, it does introduce an
92 : additional complexity in that we need to defer such comparison until parsing
93 : is complete - and function contract specifiers in class declarations must be
94 : deferred parses, since it is also permitted for specifiers to refer to class
95 : members.
96 :
97 : When we encounter a definition, the parameter names in a function decl are
98 : re-written to match those of the definition (thus the expected names will
99 : appear in debug information etc). At this point, we also need to re-map
100 : any function parameter names that appear in function contract specifiers
101 : to agree with those of the definition - although we intend to keep the
102 : 'first declaration' record consistent for diagnostics.
103 :
104 : Since we shared some code from the C++2a contracts implementation, pre and
105 : post specifiers are represented by chains of attributes, where the payload
106 : of the attribute is an AST node. However during the parse, these are not
107 : inserted into the function bodies, but kept in the decl-keyed state described
108 : above. A future improvement planned here is to store the specifiers using a
109 : tree vec instead of the attribute list.
110 :
111 : Emitting contract AST
112 : =====================
113 :
114 : When we reach `finish_function ()` and therefore are committed to potentially
115 : emitting code for an instance, we build a new variant of the function body
116 : with the pre-condition AST inserted before the user's function body, and the
117 : post condition AST (if any) linked into the function return.
118 :
119 : Lowering the contract assertion AST
120 : ===================================
121 :
122 : In all cases (pre, post, contract_assert) the AST node is lowered to control
123 : flow and (potentially) calls to the violation handler and/or termination.
124 : This is done during `cp_genericize ()`. In the current implementation, the
125 : decision on the control flow is made on the basis of the setting of a command-
126 : line flag that determines a TU-wide contract evaluation semantic, which has
127 : the following initial set of behaviours:
128 :
129 : 'ignore' : contract assertion AST is lowered to 'nothing',
130 : i.e. omitted.
131 : 'enforce' : contract assertion AST is lowered to a check, if this
132 : fails a violation handler is called, followed by
133 : std::terminate().
134 : 'quick_enforce' : contract assertion AST is lowered to a check, if this
135 : fails, std::terminate () is called.
136 : 'observe' : contract assertion AST is lowered to a check, if this
137 : fails, a violation handler is called, the code then
138 : continues.
139 :
140 : In each case, the "check" might be a simple 'if' (when it is determined that
141 : the assertion condition does not throw) or the condition evaluation will be
142 : wrapped in a try-catch block that treats any exception thrown when evaluating
143 : the check as equivalent to a failed check. It is noted in the violation data
144 : object whether a check failed because of an exception raised in evaluation.
145 :
146 : At present, a simple (but potentially space-inefficient) scheme is used to
147 : store constant data objects that represent the read-only data for the
148 : violation. The exact form of this is subject to revision as it represents
149 : ABI that must be agreed between implementations (as of this point, that
150 : discussion is not yet concluded). */
151 :
152 : /* Contract matching. */
153 :
154 : bool comparing_contracts;
155 :
156 : /* True if the contract is valid. */
157 :
158 : static bool
159 80 : contract_valid_p (tree contract)
160 : {
161 80 : return CONTRACT_CONDITION (contract) != error_mark_node;
162 : }
163 :
164 : /* True if the contract specifier is valid. */
165 :
166 : static bool
167 80 : contract_specifier_valid_p (tree contract)
168 : {
169 80 : return contract_valid_p (TREE_VALUE (TREE_VALUE (contract)));
170 : }
171 :
172 : /* Compare the contract conditions of OLD_CONTRACT and NEW_CONTRACT.
173 : Returns false if the conditions are equivalent, and true otherwise. */
174 :
175 : static bool
176 40 : mismatched_contracts_p (tree old_contract, tree new_contract)
177 : {
178 : /* Different kinds of contracts do not match. */
179 40 : if (TREE_CODE (old_contract) != TREE_CODE (new_contract))
180 : {
181 0 : auto_diagnostic_group d;
182 0 : error_at (EXPR_LOCATION (new_contract),
183 : "mismatched contract specifier in declaration");
184 0 : inform (EXPR_LOCATION (old_contract), "previous contract here");
185 0 : return true;
186 0 : }
187 :
188 : /* A deferred contract tentatively matches. */
189 40 : if (CONTRACT_CONDITION_DEFERRED_P (new_contract))
190 : return false;
191 :
192 : /* Compare the conditions of the contracts. */
193 40 : tree t1 = cp_fully_fold_init (CONTRACT_CONDITION (old_contract));
194 40 : tree t2 = cp_fully_fold_init (CONTRACT_CONDITION (new_contract));
195 :
196 : /* Compare the contracts. */
197 :
198 40 : bool saved_comparing_contracts = comparing_contracts;
199 40 : comparing_contracts = true;
200 40 : bool matching_p = cp_tree_equal (t1, t2);
201 40 : comparing_contracts = saved_comparing_contracts;
202 :
203 40 : if (!matching_p)
204 : {
205 10 : auto_diagnostic_group d;
206 10 : error_at (EXPR_LOCATION (CONTRACT_CONDITION (new_contract)),
207 : "mismatched contract condition in declaration");
208 10 : inform (EXPR_LOCATION (CONTRACT_CONDITION (old_contract)),
209 : "previous contract here");
210 10 : return true;
211 10 : }
212 :
213 : return false;
214 : }
215 :
216 : /* Compare the contract specifiers of OLDDECL and NEWDECL. Returns true
217 : if the contracts match, and false if they differ. */
218 :
219 : static bool
220 38 : match_contract_specifiers (location_t oldloc, tree old_contracts,
221 : location_t newloc, tree new_contracts)
222 : {
223 : /* Contracts only match if they are both specified. */
224 38 : if (!old_contracts || !new_contracts)
225 : return true;
226 :
227 : /* Compare each contract in turn. */
228 68 : while (old_contracts && new_contracts)
229 : {
230 : /* If either contract is ill-formed, skip the rest of the comparison,
231 : since we've already diagnosed an error. */
232 40 : if (!contract_specifier_valid_p (new_contracts)
233 40 : || !contract_specifier_valid_p (old_contracts))
234 : return false;
235 :
236 80 : if (mismatched_contracts_p (CONTRACT_STATEMENT (old_contracts),
237 40 : CONTRACT_STATEMENT (new_contracts)))
238 : return false;
239 30 : old_contracts = TREE_CHAIN (old_contracts);
240 30 : new_contracts = TREE_CHAIN (new_contracts);
241 : }
242 :
243 : /* If we didn't compare all specifiers, the contracts don't match. */
244 28 : if (old_contracts || new_contracts)
245 : {
246 4 : auto_diagnostic_group d;
247 4 : error_at (newloc,
248 : "declaration has a different number of contracts than "
249 : "previously declared");
250 4 : inform (oldloc,
251 : new_contracts
252 : ? "previous declaration with fewer contracts here"
253 : : "previous declaration with more contracts here");
254 4 : return false;
255 4 : }
256 :
257 : return true;
258 : }
259 :
260 : /* Return true if CONTRACT is checked or assumed under the current build
261 : configuration. */
262 :
263 : static bool
264 1990 : contract_active_p (tree contract)
265 : {
266 703 : return get_evaluation_semantic (contract) != CES_IGNORE;
267 : }
268 :
269 : /* True if FNDECL has any checked or assumed contracts whose TREE_CODE is
270 : C. */
271 :
272 : static bool
273 2236050 : has_active_contract_condition (tree fndecl, tree_code c)
274 : {
275 2236050 : tree as = get_fn_contract_specifiers (fndecl);
276 2236824 : for (; as != NULL_TREE; as = TREE_CHAIN (as))
277 : {
278 1477 : tree contract = TREE_VALUE (TREE_VALUE (as));
279 2180 : if (TREE_CODE (contract) == c && contract_active_p (contract))
280 : return true;
281 : }
282 : return false;
283 : }
284 :
285 : /* True if FNDECL has any checked or assumed preconditions. */
286 :
287 : static bool
288 585 : has_active_preconditions (tree fndecl)
289 : {
290 0 : return has_active_contract_condition (fndecl, PRECONDITION_STMT);
291 : }
292 :
293 : /* True if FNDECL has any checked or assumed postconditions. */
294 :
295 : static bool
296 2235465 : has_active_postconditions (tree fndecl)
297 : {
298 0 : return has_active_contract_condition (fndecl, POSTCONDITION_STMT);
299 : }
300 :
301 : /* Return true if any contract in the CONTRACT list is checked or assumed
302 : under the current build configuration. */
303 :
304 : static bool
305 296137 : contract_any_active_p (tree fndecl)
306 : {
307 296137 : tree as = get_fn_contract_specifiers (fndecl);
308 592282 : for (; as; as = TREE_CHAIN (as))
309 1287 : if (contract_active_p (TREE_VALUE (TREE_VALUE (as))))
310 : return true;
311 : return false;
312 : }
313 :
314 : /* Return true if any contract in CONTRACTS is not yet parsed. */
315 :
316 : bool
317 871 : contract_any_deferred_p (tree contracts)
318 : {
319 1675 : for (; contracts; contracts = TREE_CHAIN (contracts))
320 1088 : if (CONTRACT_CONDITION_DEFERRED_P (CONTRACT_STATEMENT (contracts)))
321 : return true;
322 : return false;
323 : }
324 :
325 : /* Returns true if function decl FNDECL has contracts and we need to
326 : process them for the purposes of either building caller or definition
327 : contract checks.
328 : This function does not take into account whether caller or definition
329 : side checking is enabled. Those checks will be done from the calling
330 : function which will be able to determine whether it is doing caller
331 : or definition contract handling. */
332 :
333 : static bool
334 699288888 : handle_contracts_p (tree fndecl)
335 : {
336 699288888 : return (flag_contracts
337 394431 : && !processing_template_decl
338 296185 : && (CONTRACT_HELPER (fndecl) == ldf_contract_none)
339 699585025 : && contract_any_active_p (fndecl));
340 : }
341 :
342 : /* For use with the tree inliner. This preserves non-mapped local variables,
343 : such as postcondition result variables, during remapping. */
344 :
345 : static tree
346 468 : retain_decl (tree decl, copy_body_data *)
347 : {
348 468 : return decl;
349 : }
350 :
351 : /* Lookup a name in std::, or inject it. */
352 :
353 : static tree
354 104 : lookup_std_type (tree name_id)
355 : {
356 104 : tree res_type = lookup_qualified_name
357 104 : (std_node, name_id, LOOK_want::TYPE | LOOK_want::HIDDEN_FRIEND);
358 :
359 104 : if (TREE_CODE (res_type) == TYPE_DECL)
360 22 : res_type = TREE_TYPE (res_type);
361 : else
362 : {
363 82 : push_nested_namespace (std_node);
364 82 : res_type = make_class_type (RECORD_TYPE);
365 82 : create_implicit_typedef (name_id, res_type);
366 82 : DECL_SOURCE_LOCATION (TYPE_NAME (res_type)) = BUILTINS_LOCATION;
367 82 : DECL_CONTEXT (TYPE_NAME (res_type)) = current_namespace;
368 82 : pushdecl_namespace_level (TYPE_NAME (res_type), /*hidden*/true);
369 82 : pop_nested_namespace (std_node);
370 : }
371 104 : return res_type;
372 : }
373 :
374 : /* Get constract_assertion_kind of the specified contract. Used when building
375 : contract_violation object. */
376 :
377 : static contract_assertion_kind
378 608 : get_contract_assertion_kind (tree contract)
379 : {
380 608 : if (CONTRACT_ASSERTION_KIND (contract))
381 : {
382 608 : tree s = CONTRACT_ASSERTION_KIND (contract);
383 608 : tree i = (TREE_CODE (s) == INTEGER_CST) ? s
384 0 : : DECL_INITIAL (STRIP_NOPS (s));
385 608 : gcc_checking_assert (!type_dependent_expression_p (s) && i);
386 608 : return (contract_assertion_kind) tree_to_uhwi (i);
387 : }
388 :
389 0 : switch (TREE_CODE (contract))
390 : {
391 : case ASSERTION_STMT: return CAK_ASSERT;
392 : case PRECONDITION_STMT: return CAK_PRE;
393 : case POSTCONDITION_STMT: return CAK_POST;
394 0 : default: break;
395 : }
396 :
397 0 : gcc_unreachable ();
398 : }
399 :
400 : /* Get contract_evaluation_semantic of the specified contract. */
401 :
402 : contract_evaluation_semantic
403 3173 : get_evaluation_semantic (const_tree contract)
404 : {
405 3173 : if (CONTRACT_EVALUATION_SEMANTIC (contract))
406 : {
407 3173 : tree s = CONTRACT_EVALUATION_SEMANTIC (contract);
408 3173 : tree i = (TREE_CODE (s) == INTEGER_CST) ? s
409 0 : : DECL_INITIAL (STRIP_NOPS (s));
410 3173 : gcc_checking_assert (!type_dependent_expression_p (s) && i);
411 3173 : switch (contract_evaluation_semantic ev =
412 3173 : (contract_evaluation_semantic) tree_to_uhwi (i))
413 : {
414 : /* This needs to be kept in step with any added semantics. */
415 3173 : case CES_IGNORE:
416 3173 : case CES_OBSERVE:
417 3173 : case CES_ENFORCE:
418 3173 : case CES_QUICK:
419 3173 : return ev;
420 : default:
421 : break;
422 : }
423 : }
424 :
425 0 : gcc_unreachable ();
426 : }
427 :
428 : /* Get location of the last contract in the CONTRACTS tree chain. */
429 :
430 : static location_t
431 881 : get_contract_end_loc (tree contracts)
432 : {
433 881 : tree last = NULL_TREE;
434 2364 : for (tree a = contracts; a; a = TREE_CHAIN (a))
435 1483 : last = a;
436 881 : gcc_checking_assert (last);
437 881 : last = CONTRACT_STATEMENT (last);
438 881 : return EXPR_LOCATION (last);
439 : }
440 :
441 : struct GTY(()) contract_decl
442 : {
443 : tree contract_specifiers;
444 : location_t note_loc;
445 : };
446 :
447 : static GTY(()) hash_map<tree, contract_decl> *contract_decl_map;
448 :
449 : /* Converts a contract condition to bool and ensures it has a location. */
450 :
451 : tree
452 1370 : finish_contract_condition (cp_expr condition)
453 : {
454 1370 : if (!condition || error_operand_p (condition))
455 : return condition;
456 :
457 : /* Ensure we have the condition location saved in case we later need to
458 : emit a conversion error during template instantiation and wouldn't
459 : otherwise have it. This differs from maybe_wrap_with_location in that
460 : it allows wrappers on EXCEPTIONAL_CLASS_P which includes CONSTRUCTORs. */
461 1360 : if (!CAN_HAVE_LOCATION_P (condition)
462 68 : && condition.get_location () != UNKNOWN_LOCATION)
463 : {
464 68 : tree_code code
465 68 : = (((CONSTANT_CLASS_P (condition) && TREE_CODE (condition) != STRING_CST)
466 0 : || (TREE_CODE (condition) == CONST_DECL && !TREE_STATIC (condition)))
467 68 : ? NON_LVALUE_EXPR : VIEW_CONVERT_EXPR);
468 68 : condition = build1_loc (condition.get_location (), code,
469 68 : TREE_TYPE (condition), condition);
470 68 : EXPR_LOCATION_WRAPPER_P (condition) = true;
471 : }
472 :
473 1360 : if (type_dependent_expression_p (condition))
474 : return condition;
475 :
476 1013 : return condition_conversion (condition);
477 : }
478 :
479 : /* Wrap the DECL into VIEW_CONVERT_EXPR representing const qualified version
480 : of the declaration. */
481 :
482 : tree
483 1637 : view_as_const (tree decl)
484 : {
485 1637 : if (!contract_const_wrapper_p (decl))
486 : {
487 1637 : tree ctype = TREE_TYPE (decl);
488 1637 : location_t loc =
489 1637 : EXPR_P (decl) ? EXPR_LOCATION (decl) : DECL_SOURCE_LOCATION (decl);
490 1637 : ctype = cp_build_qualified_type (ctype, (cp_type_quals (ctype)
491 : | TYPE_QUAL_CONST));
492 1637 : decl = build1 (VIEW_CONVERT_EXPR, ctype, decl);
493 1637 : SET_EXPR_LOCATION (decl, loc);
494 : /* Mark the VCE as contract const wrapper. */
495 1637 : CONST_WRAPPER_P (decl) = true;
496 : }
497 1637 : return decl;
498 : }
499 :
500 : /* Constify access to DECL from within the contract condition. */
501 :
502 : tree
503 1670 : constify_contract_access (tree decl)
504 : {
505 : /* We check if we have a variable, a parameter, a variable of reference type,
506 : * or a parameter of reference type
507 : */
508 1670 : if (!TREE_READONLY (decl)
509 1670 : && (VAR_P (decl)
510 1398 : || (TREE_CODE (decl) == PARM_DECL)
511 462 : || (REFERENCE_REF_P (decl)
512 90 : && (VAR_P (TREE_OPERAND (decl, 0))
513 87 : || (TREE_CODE (TREE_OPERAND (decl, 0)) == PARM_DECL)
514 5 : || (TREE_CODE (TREE_OPERAND (decl, 0))
515 : == TEMPLATE_PARM_INDEX)))))
516 1101 : decl = view_as_const (decl);
517 :
518 1670 : return decl;
519 : }
520 :
521 : /* Indicate that PARM_DECL DECL is ODR used in a postcondition. */
522 :
523 : static void
524 532 : set_parm_used_in_post (tree decl, bool constify = true)
525 : {
526 532 : gcc_checking_assert (TREE_CODE (decl) == PARM_DECL);
527 532 : DECL_LANG_FLAG_4 (decl) = constify;
528 532 : }
529 :
530 : /* Test if PARM_DECL is ODR used in a postcondition. */
531 :
532 : static bool
533 483 : parm_used_in_post_p (const_tree decl)
534 : {
535 : /* Check if this parameter is odr used within a function's postcondition */
536 483 : return ((TREE_CODE (decl) == PARM_DECL) && DECL_LANG_FLAG_4 (decl));
537 : }
538 :
539 : /* If declaration DECL is a PARM_DECL and it appears in a postcondition, then
540 : check that it is not a non-const by-value param. LOCATION is where the
541 : expression was found and is used for diagnostic purposes. */
542 :
543 : void
544 699533398 : check_param_in_postcondition (tree decl, location_t location)
545 : {
546 699533398 : if (processing_postcondition
547 1063 : && TREE_CODE (decl) == PARM_DECL
548 : /* TREE_CODE (decl) == PARM_DECL only holds for non-reference
549 : parameters. */
550 670 : && !cp_unevaluated_operand
551 : /* Return value parameter has DECL_ARTIFICIAL flag set. The flag
552 : presence of the flag should be sufficient to distinguish the
553 : return value parameter in this context. */
554 699533924 : && !(DECL_ARTIFICIAL (decl)))
555 : {
556 370 : set_parm_used_in_post (decl);
557 :
558 370 : if (!dependent_type_p (TREE_TYPE (decl))
559 370 : && !CP_TYPE_CONST_P (TREE_TYPE (decl)))
560 : {
561 76 : error_at (location,
562 : "a value parameter used in a postcondition must be const");
563 76 : inform (DECL_SOURCE_LOCATION (decl), "parameter declared here");
564 : }
565 : }
566 699533398 : }
567 :
568 : /* Check if parameters used in postconditions are const qualified on
569 : a redeclaration that does not specify contracts or on an instantiation
570 : of a function template. */
571 :
572 : void
573 149546080 : check_postconditions_in_redecl (tree olddecl, tree newdecl)
574 : {
575 149546080 : tree contract_spec = get_fn_contract_specifiers (olddecl);
576 149546080 : if (!contract_spec)
577 : return;
578 :
579 284 : tree t1 = FUNCTION_FIRST_USER_PARM (olddecl);
580 284 : tree t2 = FUNCTION_FIRST_USER_PARM (newdecl);
581 :
582 1051 : for (; t1 && t1 != void_list_node;
583 483 : t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
584 : {
585 483 : if (parm_used_in_post_p (t1))
586 : {
587 162 : set_parm_used_in_post (t2);
588 162 : if (!dependent_type_p (TREE_TYPE (t2))
589 126 : && !CP_TYPE_CONST_P (TREE_TYPE (t2))
590 224 : && !TREE_READONLY (t2))
591 : {
592 62 : error_at (DECL_SOURCE_LOCATION (t2),
593 : "value parameter %qE used in a postcondition must be const", t2);
594 62 : inform (DECL_SOURCE_LOCATION (olddecl),
595 : "previous declaration here");
596 : }
597 : }
598 : }
599 : }
600 :
601 : /* Map from FUNCTION_DECL to a FUNCTION_DECL for either the PRE_FN or POST_FN.
602 : These are used to parse contract conditions and are called inside the body
603 : of the guarded function. */
604 : static GTY(()) hash_map<tree, tree> *decl_pre_fn;
605 : static GTY(()) hash_map<tree, tree> *decl_post_fn;
606 :
607 : /* Given a pre or post function decl (for an outlined check function) return
608 : the decl for the function for which the outlined checks are being
609 : performed. */
610 : static GTY(()) hash_map<tree, tree> *orig_from_outlined;
611 :
612 : /* Makes PRE the precondition function for FNDECL. */
613 :
614 : static void
615 8 : set_precondition_function (tree fndecl, tree pre)
616 : {
617 8 : gcc_assert (pre);
618 8 : hash_map_maybe_create<hm_ggc> (decl_pre_fn);
619 8 : gcc_checking_assert (!decl_pre_fn->get (fndecl));
620 8 : decl_pre_fn->put (fndecl, pre);
621 :
622 8 : hash_map_maybe_create<hm_ggc> (orig_from_outlined);
623 8 : gcc_checking_assert (!orig_from_outlined->get (pre));
624 8 : orig_from_outlined->put (pre, fndecl);
625 8 : }
626 :
627 : /* Makes POST the postcondition function for FNDECL. */
628 :
629 : static void
630 26 : set_postcondition_function (tree fndecl, tree post)
631 : {
632 26 : gcc_checking_assert (post);
633 26 : hash_map_maybe_create<hm_ggc> (decl_post_fn);
634 26 : gcc_checking_assert (!decl_post_fn->get (fndecl));
635 26 : decl_post_fn->put (fndecl, post);
636 :
637 26 : hash_map_maybe_create<hm_ggc> (orig_from_outlined);
638 26 : gcc_checking_assert (!orig_from_outlined->get (post));
639 26 : orig_from_outlined->put (post, fndecl);
640 26 : }
641 :
642 : /* For a given pre or post condition function, find the checked function. */
643 : tree
644 18 : get_orig_for_outlined (tree fndecl)
645 : {
646 18 : gcc_checking_assert (fndecl);
647 18 : tree *result = hash_map_safe_get (orig_from_outlined, fndecl);
648 18 : return result ? *result : NULL_TREE ;
649 : }
650 :
651 : /* For a given function OLD_FN set suitable names for NEW_FN (which is an
652 : outlined contract check) usually by appending '.pre' or '.post'.
653 :
654 : For functions with special meaning names (i.e. main and cdtors) we need to
655 : make special provisions and therefore handle all the contracts function
656 : name changes here, rather than requiring a separate update to mangle.cc.
657 :
658 : PRE specifies if we need an identifier for a pre or post contract check. */
659 :
660 : static void
661 56 : contracts_fixup_names (tree new_fn, tree old_fn, bool pre, bool wrapper)
662 : {
663 56 : bool cdtor = DECL_CXX_CONSTRUCTOR_P (old_fn)
664 56 : || DECL_CXX_DESTRUCTOR_P (old_fn);
665 56 : const char *fname = IDENTIFIER_POINTER (DECL_NAME (old_fn));
666 82 : const char *append = wrapper ? "contract_wrapper"
667 34 : : (pre ? "pre" : "post");
668 56 : size_t len = strlen (fname);
669 : /* Cdtor names have a space at the end. We need to remove that space
670 : when forming the new identifier. */
671 56 : char *nn = xasprintf ("%.*s%s%s",
672 0 : cdtor ? (int)len-1 : int(len),
673 : fname,
674 : JOIN_STR,
675 : append);
676 56 : DECL_NAME (new_fn) = get_identifier (nn);
677 56 : free (nn);
678 :
679 : /* Now do the mangled version. */
680 56 : fname = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (old_fn));
681 56 : nn = xasprintf ("%s%s%s", fname, JOIN_STR, append);
682 56 : SET_DECL_ASSEMBLER_NAME (new_fn, get_identifier (nn));
683 56 : free (nn);
684 56 : }
685 :
686 : /* Build a declaration for the pre- or postcondition of a guarded FNDECL. */
687 :
688 : static tree
689 34 : build_contract_condition_function (tree fndecl, bool pre)
690 : {
691 34 : if (error_operand_p (fndecl))
692 0 : return error_mark_node;
693 :
694 : /* Start the copy. */
695 34 : tree fn = copy_decl (fndecl);
696 :
697 : /* Don't propagate declaration attributes to the checking function,
698 : including the original contracts. */
699 34 : DECL_ATTRIBUTES (fn) = NULL_TREE;
700 :
701 : /* If requested, disable optimisation of checking functions; this can, in
702 : some cases, prevent UB from eliding the checks themselves. */
703 34 : if (flag_contract_disable_optimized_checks)
704 0 : DECL_ATTRIBUTES (fn)
705 0 : = tree_cons (get_identifier ("optimize"),
706 : build_tree_list (NULL_TREE, build_string (3, "-O0")),
707 : NULL_TREE);
708 :
709 : /* Now parse and add any internal representation of these attrs to the
710 : decl. */
711 34 : if (DECL_ATTRIBUTES (fn))
712 0 : cplus_decl_attributes (&fn, DECL_ATTRIBUTES (fn), 0);
713 :
714 : /* A possible later optimization may delete unused args to prevent extra arg
715 : passing. */
716 : /* Handle the args list. */
717 34 : tree arg_types = NULL_TREE;
718 34 : tree *last = &arg_types;
719 34 : for (tree arg_type = TYPE_ARG_TYPES (TREE_TYPE (fn));
720 89 : arg_type && arg_type != void_list_node;
721 55 : arg_type = TREE_CHAIN (arg_type))
722 : {
723 55 : if (DECL_IOBJ_MEMBER_FUNCTION_P (fndecl)
724 55 : && TYPE_ARG_TYPES (TREE_TYPE (fn)) == arg_type)
725 22 : continue;
726 33 : *last = build_tree_list (TREE_PURPOSE (arg_type), TREE_VALUE (arg_type));
727 33 : last = &TREE_CHAIN (*last);
728 : }
729 :
730 : /* Copy the function parameters, if present. Disable warnings for them. */
731 34 : DECL_ARGUMENTS (fn) = NULL_TREE;
732 34 : if (DECL_ARGUMENTS (fndecl))
733 : {
734 31 : tree *last_a = &DECL_ARGUMENTS (fn);
735 86 : for (tree p = DECL_ARGUMENTS (fndecl); p; p = TREE_CHAIN (p))
736 : {
737 55 : *last_a = copy_decl (p);
738 55 : suppress_warning (*last_a);
739 55 : DECL_CONTEXT (*last_a) = fn;
740 55 : last_a = &TREE_CHAIN (*last_a);
741 : }
742 : }
743 :
744 34 : tree orig_fn_value_type = TREE_TYPE (TREE_TYPE (fn));
745 34 : if (!pre && !VOID_TYPE_P (orig_fn_value_type))
746 : {
747 : /* For post contracts that deal with a non-void function, append a
748 : parameter to pass the return value. */
749 20 : tree name = get_identifier ("__r");
750 20 : tree parm = build_lang_decl (PARM_DECL, name, orig_fn_value_type);
751 20 : DECL_CONTEXT (parm) = fn;
752 20 : DECL_ARTIFICIAL (parm) = true;
753 20 : suppress_warning (parm);
754 20 : DECL_ARGUMENTS (fn) = chainon (DECL_ARGUMENTS (fn), parm);
755 20 : *last = build_tree_list (NULL_TREE, orig_fn_value_type);
756 20 : last = &TREE_CHAIN (*last);
757 : }
758 :
759 34 : *last = void_list_node;
760 :
761 34 : tree adjusted_type = NULL_TREE;
762 :
763 : /* The handlers are void fns. */
764 34 : if (DECL_IOBJ_MEMBER_FUNCTION_P (fndecl))
765 22 : adjusted_type = build_method_type_directly (DECL_CONTEXT (fndecl),
766 : void_type_node,
767 : arg_types);
768 : else
769 12 : adjusted_type = build_function_type (void_type_node, arg_types);
770 :
771 : /* If the original function is noexcept, build a noexcept function. */
772 34 : if (flag_exceptions && type_noexcept_p (TREE_TYPE (fndecl)))
773 4 : adjusted_type = build_exception_variant (adjusted_type, noexcept_true_spec);
774 :
775 34 : TREE_TYPE (fn) = adjusted_type;
776 34 : DECL_RESULT (fn) = NULL_TREE; /* Let the start function code fill it in. */
777 :
778 : /* The contract check functions are never a cdtor, nor virtual. */
779 34 : DECL_CXX_DESTRUCTOR_P (fn) = DECL_CXX_CONSTRUCTOR_P (fn) = 0;
780 34 : DECL_VIRTUAL_P (fn) = false;
781 :
782 : /* Append .pre / .post to a usable name for the original function. */
783 34 : contracts_fixup_names (fn, fndecl, pre, /*wrapper*/false);
784 :
785 34 : DECL_INITIAL (fn) = NULL_TREE;
786 60 : CONTRACT_HELPER (fn) = pre ? ldf_contract_pre : ldf_contract_post;
787 : /* We might have a pre/post for a wrapper. */
788 34 : DECL_CONTRACT_WRAPPER (fn) = DECL_CONTRACT_WRAPPER (fndecl);
789 :
790 : /* Make these functions internal if we can, i.e. if the guarded function is
791 : not vague linkage, or if we can put them in a comdat group with the
792 : guarded function. */
793 34 : if (!DECL_WEAK (fndecl) || HAVE_COMDAT_GROUP)
794 : {
795 34 : TREE_PUBLIC (fn) = false;
796 34 : DECL_EXTERNAL (fn) = false;
797 34 : DECL_WEAK (fn) = false;
798 34 : DECL_COMDAT (fn) = false;
799 :
800 : /* We may not have set the comdat group on the guarded function yet.
801 : If we haven't, we'll add this to the same group in comdat_linkage
802 : later. Otherwise, add it to the same comdat group now. */
803 34 : if (DECL_ONE_ONLY (fndecl))
804 : {
805 0 : symtab_node *n = symtab_node::get (fndecl);
806 0 : cgraph_node::get_create (fn)->add_to_same_comdat_group (n);
807 : }
808 :
809 : }
810 :
811 34 : DECL_INTERFACE_KNOWN (fn) = true;
812 34 : DECL_ARTIFICIAL (fn) = true;
813 34 : suppress_warning (fn);
814 :
815 34 : return fn;
816 : }
817 :
818 : /* Build the precondition checking function for FNDECL. */
819 :
820 : static tree
821 15 : build_precondition_function (tree fndecl)
822 : {
823 15 : if (!has_active_preconditions (fndecl))
824 : return NULL_TREE;
825 :
826 8 : return build_contract_condition_function (fndecl, /*pre=*/true);
827 : }
828 :
829 : /* Build the postcondition checking function for FNDECL. If the return
830 : type is undeduced, don't build the function yet. We do that in
831 : apply_deduced_return_type. */
832 :
833 : static tree
834 33 : build_postcondition_function (tree fndecl)
835 : {
836 33 : if (!has_active_postconditions (fndecl))
837 : return NULL_TREE;
838 :
839 26 : tree type = TREE_TYPE (TREE_TYPE (fndecl));
840 26 : if (is_auto (type))
841 : return NULL_TREE;
842 :
843 26 : return build_contract_condition_function (fndecl, /*pre=*/false);
844 : }
845 :
846 : /* If we're outlining the contract, build the functions to do the
847 : precondition and postcondition checks, and associate them with
848 : the function decl FNDECL.
849 : */
850 :
851 : static void
852 15 : build_contract_function_decls (tree fndecl)
853 : {
854 : /* Build the pre/post functions (or not). */
855 15 : if (!get_precondition_function (fndecl))
856 15 : if (tree pre = build_precondition_function (fndecl))
857 8 : set_precondition_function (fndecl, pre);
858 :
859 15 : if (!get_postcondition_function (fndecl))
860 15 : if (tree post = build_postcondition_function (fndecl))
861 8 : set_postcondition_function (fndecl, post);
862 15 : }
863 :
864 : /* Map from FUNCTION_DECL to a FUNCTION_DECL for contract wrapper. */
865 :
866 : static GTY(()) hash_map<tree, tree> *decl_wrapper_fn = nullptr;
867 :
868 : /* Map from the function decl of a wrapper to the function that it wraps. */
869 :
870 : static GTY(()) hash_map<tree, tree> *decl_for_wrapper = nullptr;
871 :
872 : /* Makes wrapper the precondition function for FNDECL. */
873 :
874 : static void
875 22 : set_contract_wrapper_function (tree fndecl, tree wrapper)
876 : {
877 22 : gcc_checking_assert (wrapper && fndecl);
878 22 : hash_map_maybe_create<hm_ggc> (decl_wrapper_fn);
879 22 : gcc_checking_assert (decl_wrapper_fn && !decl_wrapper_fn->get (fndecl));
880 22 : decl_wrapper_fn->put (fndecl, wrapper);
881 :
882 : /* We need to know the wrapped function when composing the diagnostic. */
883 22 : hash_map_maybe_create<hm_ggc> (decl_for_wrapper);
884 22 : gcc_checking_assert (decl_for_wrapper && !decl_for_wrapper->get (wrapper));
885 22 : decl_for_wrapper->put (wrapper, fndecl);
886 22 : }
887 :
888 : /* Returns the wrapper function decl for FNDECL, or null if not set. */
889 :
890 : static tree
891 22 : get_contract_wrapper_function (tree fndecl)
892 : {
893 22 : gcc_checking_assert (fndecl);
894 22 : tree *result = hash_map_safe_get (decl_wrapper_fn, fndecl);
895 11 : return result ? *result : NULL_TREE;
896 : }
897 :
898 : /* Given a wrapper function WRAPPER, find the original function decl. */
899 :
900 : static tree
901 34 : get_orig_func_for_wrapper (tree wrapper)
902 : {
903 34 : gcc_checking_assert (wrapper);
904 34 : tree *result = hash_map_safe_get (decl_for_wrapper, wrapper);
905 34 : return result ? *result : NULL_TREE;
906 : }
907 :
908 : /* Build a declaration for the contract wrapper of a caller FNDECL.
909 : We're making a caller side contract check wrapper. For caller side contract
910 : checks, postconditions are only checked if check_post is true.
911 : Defer the attachment of the contracts to this function until the callee
912 : is non-dependent, or we get cases where the conditions can be non-dependent
913 : but still need tsubst-ing. */
914 :
915 : static tree
916 22 : build_contract_wrapper_function (tree fndecl)
917 : {
918 22 : if (error_operand_p (fndecl))
919 0 : return error_mark_node;
920 :
921 : /* We should not be trying to build wrappers for templates or functions that
922 : are still dependent. */
923 22 : gcc_checking_assert (!processing_template_decl
924 : && !TYPE_DEPENDENT_P (TREE_TYPE (fndecl)));
925 :
926 22 : location_t loc = DECL_SOURCE_LOCATION (fndecl);
927 :
928 : /* Fill in the names later. */
929 22 : tree wrapdecl
930 22 : = build_lang_decl_loc (loc, FUNCTION_DECL, NULL_TREE, TREE_TYPE (fndecl));
931 :
932 : /* Put the wrapper in the same context as the callee. */
933 22 : DECL_CONTEXT (wrapdecl) = DECL_CONTEXT (fndecl);
934 :
935 : /* This declaration is a contract wrapper function. */
936 22 : DECL_CONTRACT_WRAPPER (wrapdecl) = true;
937 :
938 22 : contracts_fixup_names (wrapdecl, fndecl, /*pre*/false, /*wrapper*/true);
939 :
940 22 : DECL_SOURCE_LOCATION (wrapdecl) = loc;
941 : /* The declaration was implicitly generated by the compiler. */
942 22 : DECL_ARTIFICIAL (wrapdecl) = true;
943 : /* Declaration, no definition yet. */
944 22 : DECL_INITIAL (wrapdecl) = NULL_TREE;
945 :
946 : /* Let the start function code fill in the result decl. */
947 22 : DECL_RESULT (wrapdecl) = NULL_TREE;
948 :
949 : /* Copy the function parameters, if present. Suppress (e.g. unused)
950 : warnings on them. */
951 22 : DECL_ARGUMENTS (wrapdecl) = NULL_TREE;
952 22 : if (tree p = DECL_ARGUMENTS (fndecl))
953 : {
954 22 : tree *last_a = &DECL_ARGUMENTS (wrapdecl);
955 70 : for (; p; p = TREE_CHAIN (p))
956 : {
957 48 : *last_a = copy_decl (p);
958 48 : suppress_warning (*last_a);
959 48 : DECL_CONTEXT (*last_a) = wrapdecl;
960 48 : last_a = &TREE_CHAIN (*last_a);
961 : }
962 : }
963 :
964 : /* Copy selected attributes from the original function. */
965 22 : TREE_USED (wrapdecl) = TREE_USED (fndecl);
966 :
967 : /* Copy any alignment added. */
968 22 : if (DECL_ALIGN (fndecl))
969 22 : SET_DECL_ALIGN (wrapdecl, DECL_ALIGN (fndecl));
970 22 : DECL_USER_ALIGN (wrapdecl) = DECL_USER_ALIGN (fndecl);
971 :
972 : /* Make this function internal. */
973 22 : TREE_PUBLIC (wrapdecl) = false;
974 22 : DECL_EXTERNAL (wrapdecl) = false;
975 22 : DECL_WEAK (wrapdecl) = false;
976 :
977 : /* We know this is an internal function. */
978 22 : DECL_INTERFACE_KNOWN (wrapdecl) = true;
979 22 : return wrapdecl;
980 : }
981 :
982 : static tree
983 22 : get_or_create_contract_wrapper_function (tree fndecl)
984 : {
985 22 : tree wrapdecl = get_contract_wrapper_function (fndecl);
986 22 : if (!wrapdecl)
987 : {
988 22 : wrapdecl = build_contract_wrapper_function (fndecl);
989 22 : set_contract_wrapper_function (fndecl, wrapdecl);
990 : }
991 22 : return wrapdecl;
992 : }
993 :
994 : void
995 166164470 : start_function_contracts (tree fndecl)
996 : {
997 166164470 : if (error_operand_p (fndecl))
998 : return;
999 :
1000 166164470 : if (!handle_contracts_p (fndecl))
1001 : return;
1002 :
1003 : /* If this is not a client side check and definition side checks are
1004 : disabled, do nothing. */
1005 354 : if (!flag_contracts_definition_check
1006 354 : && !DECL_CONTRACT_WRAPPER (fndecl))
1007 : return;
1008 :
1009 : /* Check that the postcondition result name, if any, does not shadow a
1010 : function parameter. */
1011 906 : for (tree ca = get_fn_contract_specifiers (fndecl); ca; ca = TREE_CHAIN (ca))
1012 553 : if (POSTCONDITION_P (CONTRACT_STATEMENT (ca)))
1013 245 : if (tree id = POSTCONDITION_IDENTIFIER (CONTRACT_STATEMENT (ca)))
1014 : {
1015 113 : if (id == error_mark_node)
1016 : {
1017 2 : CONTRACT_CONDITION (CONTRACT_STATEMENT (ca)) = error_mark_node;
1018 2 : continue;
1019 : }
1020 111 : tree r_name = tree_strip_any_location_wrapper (id);
1021 111 : if (TREE_CODE (id) == PARM_DECL)
1022 111 : r_name = DECL_NAME (id);
1023 111 : gcc_checking_assert (r_name && TREE_CODE (r_name) == IDENTIFIER_NODE);
1024 111 : tree seen = lookup_name (r_name);
1025 111 : if (seen
1026 2 : && TREE_CODE (seen) == PARM_DECL
1027 113 : && DECL_CONTEXT (seen) == fndecl)
1028 : {
1029 2 : auto_diagnostic_group d;
1030 2 : location_t id_l = location_wrapper_p (id)
1031 2 : ? EXPR_LOCATION (id)
1032 2 : : DECL_SOURCE_LOCATION (id);
1033 2 : location_t co_l = EXPR_LOCATION (CONTRACT_STATEMENT (ca));
1034 2 : if (id_l != UNKNOWN_LOCATION)
1035 2 : co_l = make_location (id_l, co_l, co_l);
1036 2 : error_at (co_l, "contract postcondition result name shadows a"
1037 : " function parameter");
1038 2 : inform (DECL_SOURCE_LOCATION (seen),
1039 : "parameter declared here");
1040 2 : POSTCONDITION_IDENTIFIER (CONTRACT_STATEMENT (ca))
1041 2 : = error_mark_node;
1042 2 : CONTRACT_CONDITION (CONTRACT_STATEMENT (ca)) = error_mark_node;
1043 2 : }
1044 : }
1045 :
1046 : /* If we are expanding contract assertions inline then no need to declare
1047 : the outline function decls. */
1048 353 : if (!flag_contract_checks_outlined)
1049 : return;
1050 :
1051 : /* Contracts may have just been added without a chance to parse them, though
1052 : we still need the PRE_FN available to generate a call to it. */
1053 : /* Do we already have declarations generated ? */
1054 15 : if (!DECL_PRE_FN (fndecl) && !DECL_POST_FN (fndecl))
1055 15 : build_contract_function_decls (fndecl);
1056 : }
1057 :
1058 : void
1059 2234862 : maybe_update_postconditions (tree fndecl)
1060 : {
1061 : /* Update any postconditions and the postcondition checking function
1062 : as needed. If there are postconditions, we'll use those to rewrite
1063 : return statements to check postconditions. */
1064 2234862 : if (has_active_postconditions (fndecl))
1065 : {
1066 18 : rebuild_postconditions (fndecl);
1067 18 : tree post = build_postcondition_function (fndecl);
1068 18 : set_postcondition_function (fndecl, post);
1069 : }
1070 2234862 : }
1071 :
1072 : /* Build and return an argument list containing all the parameters of the
1073 : (presumably guarded) function decl FNDECL. This can be used to forward
1074 : all of FNDECL arguments to a function taking the same list of arguments
1075 : -- namely the unchecked form of FNDECL.
1076 :
1077 : We use CALL_FROM_THUNK_P instead of forward_parm for forwarding
1078 : semantics. */
1079 :
1080 : static vec<tree, va_gc> *
1081 38 : build_arg_list (tree fndecl)
1082 : {
1083 38 : vec<tree, va_gc> *args = make_tree_vector ();
1084 109 : for (tree t = DECL_ARGUMENTS (fndecl); t; t = DECL_CHAIN (t))
1085 71 : vec_safe_push (args, t);
1086 38 : return args;
1087 : }
1088 :
1089 : /* Build and return a thunk like call to FUNC from CALLER using the supplied
1090 : arguments. The call is like a thunk call in the fact that we do not
1091 : want to create additional copies of the arguments. We can not simply reuse
1092 : the thunk machinery as it does more than we want. More specifically, we
1093 : don't want to mark the calling function as `DECL_THUNK_P` for this
1094 : particular purpose, we only want the special treatment for the parameters
1095 : of the call we are about to generate. We temporarily mark the calling
1096 : function as DECL_THUNK_P so build_call_a does the right thing. */
1097 :
1098 : static tree
1099 38 : build_thunk_like_call (tree func, int n, tree *argarray)
1100 : {
1101 38 : bool old_decl_thunk_p = DECL_THUNK_P (current_function_decl);
1102 38 : LANG_DECL_FN_CHECK (current_function_decl)->thunk_p = true;
1103 :
1104 38 : tree call = build_call_a (func, n, argarray);
1105 :
1106 : /* Revert the `DECL_THUNK_P` flag. */
1107 38 : LANG_DECL_FN_CHECK (current_function_decl)->thunk_p = old_decl_thunk_p;
1108 :
1109 : /* Mark the call as a thunk call to allow for correct gimplification
1110 : of the arguments. */
1111 38 : CALL_FROM_THUNK_P (call) = true;
1112 :
1113 38 : return call;
1114 : }
1115 :
1116 : /* If we have a precondition function and it's valid, call it. */
1117 :
1118 : static void
1119 8 : add_pre_condition_fn_call (tree fndecl)
1120 : {
1121 : /* If we're starting a guarded function with valid contracts, we need to
1122 : insert a call to the pre function. */
1123 8 : gcc_checking_assert (DECL_PRE_FN (fndecl)
1124 : && DECL_PRE_FN (fndecl) != error_mark_node);
1125 :
1126 8 : releasing_vec args = build_arg_list (fndecl);
1127 8 : tree call = build_thunk_like_call (DECL_PRE_FN (fndecl),
1128 8 : args->length (), args->address ());
1129 :
1130 8 : finish_expr_stmt (call);
1131 8 : }
1132 :
1133 : /* Returns the parameter corresponding to the return value of a guarded
1134 : function FNDECL. Returns NULL_TREE if FNDECL has no postconditions or
1135 : is void. */
1136 :
1137 : static tree
1138 8 : get_postcondition_result_parameter (tree fndecl)
1139 : {
1140 8 : if (!fndecl || fndecl == error_mark_node)
1141 : return NULL_TREE;
1142 :
1143 8 : if (VOID_TYPE_P (TREE_TYPE (TREE_TYPE (fndecl))))
1144 : return NULL_TREE;
1145 :
1146 2 : tree post = DECL_POST_FN (fndecl);
1147 2 : if (!post || post == error_mark_node)
1148 : return NULL_TREE;
1149 :
1150 : /* The last param is the return value. */
1151 2 : return tree_last (DECL_ARGUMENTS (post));
1152 : }
1153 :
1154 : /* Build and add a call to the post-condition checking function, when that
1155 : is in use. */
1156 :
1157 : static void
1158 8 : add_post_condition_fn_call (tree fndecl)
1159 : {
1160 8 : gcc_checking_assert (DECL_POST_FN (fndecl)
1161 : && DECL_POST_FN (fndecl) != error_mark_node);
1162 :
1163 8 : releasing_vec args = build_arg_list (fndecl);
1164 8 : if (get_postcondition_result_parameter (fndecl))
1165 2 : vec_safe_push (args, DECL_RESULT (fndecl));
1166 8 : tree call = build_thunk_like_call (DECL_POST_FN (fndecl),
1167 8 : args->length (), args->address ());
1168 8 : finish_expr_stmt (call);
1169 8 : }
1170 :
1171 : /* Copy (possibly a sub-set of) contracts from CONTRACTS on FNDECL. */
1172 :
1173 : static tree
1174 390 : copy_contracts_list (tree contracts, tree fndecl,
1175 : contract_match_kind remap_kind = cmk_all)
1176 : {
1177 390 : tree last = NULL_TREE, new_contracts = NULL_TREE;
1178 1065 : for (; contracts; contracts = TREE_CHAIN (contracts))
1179 : {
1180 815 : if ((remap_kind == cmk_pre
1181 365 : && (TREE_CODE (CONTRACT_STATEMENT (contracts))
1182 : == POSTCONDITION_STMT))
1183 974 : || (remap_kind == cmk_post
1184 310 : && (TREE_CODE (CONTRACT_STATEMENT (contracts))
1185 : == PRECONDITION_STMT)))
1186 140 : continue;
1187 :
1188 535 : tree c = copy_node (contracts);
1189 1070 : TREE_VALUE (c) = build_tree_list (TREE_PURPOSE (TREE_VALUE (c)),
1190 535 : copy_node (CONTRACT_STATEMENT (c)));
1191 :
1192 535 : copy_body_data id;
1193 535 : hash_map<tree, tree> decl_map;
1194 :
1195 535 : memset (&id, 0, sizeof (id));
1196 :
1197 535 : id.src_fn = fndecl;
1198 535 : id.dst_fn = fndecl;
1199 535 : id.src_cfun = DECL_STRUCT_FUNCTION (fndecl);
1200 535 : id.decl_map = &decl_map;
1201 :
1202 535 : id.copy_decl = retain_decl;
1203 :
1204 535 : id.transform_call_graph_edges = CB_CGE_DUPLICATE;
1205 535 : id.transform_new_cfg = false;
1206 535 : id.transform_return_to_modify = false;
1207 535 : id.transform_parameter = true;
1208 :
1209 : /* Make sure not to unshare trees behind the front-end's back
1210 : since front-end specific mechanisms may rely on sharing. */
1211 535 : id.regimplify = false;
1212 535 : id.do_not_unshare = true;
1213 535 : id.do_not_fold = true;
1214 :
1215 : /* We're not inside any EH region. */
1216 535 : id.eh_lp_nr = 0;
1217 535 : walk_tree (&CONTRACT_CONDITION (CONTRACT_STATEMENT (c)),
1218 : copy_tree_body_r, &id, NULL);
1219 :
1220 :
1221 1070 : CONTRACT_COMMENT (CONTRACT_STATEMENT (c))
1222 535 : = copy_node (CONTRACT_COMMENT (CONTRACT_STATEMENT (c)));
1223 :
1224 535 : chainon (last, c);
1225 535 : last = c;
1226 535 : if (!new_contracts)
1227 390 : new_contracts = c;
1228 535 : }
1229 390 : return new_contracts;
1230 : }
1231 :
1232 : /* Returns a copy of FNDECL contracts. This is used when emiting a contract.
1233 : If we were to emit the original contract tree, any folding of the contract
1234 : condition would affect the original contract too. The original contract
1235 : tree needs to be preserved in case it is used to apply to a different
1236 : function (for inheritance or wrapping reasons). */
1237 :
1238 : static tree
1239 390 : copy_contracts (tree fndecl, contract_match_kind remap_kind = cmk_all)
1240 : {
1241 390 : tree contracts = get_fn_contract_specifiers (fndecl);
1242 390 : return copy_contracts_list (contracts, fndecl, remap_kind);
1243 : }
1244 :
1245 : /* Add the contract statement CONTRACT to the current block if valid. */
1246 :
1247 : static bool
1248 553 : emit_contract_statement (tree contract)
1249 : {
1250 : /* Only add valid contracts. */
1251 553 : if (contract == error_mark_node
1252 553 : || CONTRACT_CONDITION (contract) == error_mark_node)
1253 : return false;
1254 :
1255 545 : if (get_evaluation_semantic (contract) == CES_INVALID)
1256 : return false;
1257 :
1258 545 : add_stmt (contract);
1259 545 : return true;
1260 : }
1261 :
1262 : /* Generate the statement for the given contract by adding the contract
1263 : statement to the current block. Returns the next contract in the chain. */
1264 :
1265 : static tree
1266 535 : emit_contract (tree contract)
1267 : {
1268 535 : gcc_assert (TREE_CODE (contract) == TREE_LIST);
1269 :
1270 535 : emit_contract_statement (CONTRACT_STATEMENT (contract));
1271 :
1272 535 : return TREE_CHAIN (contract);
1273 : }
1274 :
1275 : /* Add a call or a direct evaluation of the pre checks. */
1276 :
1277 : static void
1278 240 : apply_preconditions (tree fndecl)
1279 : {
1280 240 : if (flag_contract_checks_outlined)
1281 8 : add_pre_condition_fn_call (fndecl);
1282 : else
1283 : {
1284 232 : tree contract_copy = copy_contracts (fndecl, cmk_pre);
1285 763 : for (; contract_copy; contract_copy = TREE_CHAIN (contract_copy))
1286 299 : emit_contract (contract_copy);
1287 : }
1288 240 : }
1289 :
1290 : /* Add a call or a direct evaluation of the post checks. */
1291 :
1292 : static void
1293 166 : apply_postconditions (tree fndecl)
1294 : {
1295 166 : if (flag_contract_checks_outlined)
1296 8 : add_post_condition_fn_call (fndecl);
1297 : else
1298 : {
1299 158 : tree contract_copy = copy_contracts (fndecl, cmk_post);
1300 552 : for (; contract_copy; contract_copy = TREE_CHAIN (contract_copy))
1301 236 : emit_contract (contract_copy);
1302 : }
1303 166 : }
1304 :
1305 : /* Add contract handling to the function in FNDECL.
1306 :
1307 : When we have only pre-conditions, this simply prepends a call (or a direct
1308 : evaluation, for cdtors) to the existing function body.
1309 :
1310 : When we have post conditions we build a try-finally block.
1311 : If the function might throw then the handler in the try-finally is an
1312 : EH_ELSE expression, where the post condition check is applied to the
1313 : non-exceptional path, and an empty statement is added to the EH path. If
1314 : the function has a non-throwing eh spec, then the handler is simply the
1315 : post-condition checker. */
1316 :
1317 : void
1318 148595904 : maybe_apply_function_contracts (tree fndecl)
1319 : {
1320 148595904 : if (!handle_contracts_p (fndecl))
1321 : /* We did nothing and the original function body statement list will be
1322 : popped by our caller. */
1323 : return;
1324 :
1325 : /* If this is not a client side check and definition side checks are
1326 : disabled, do nothing. */
1327 354 : if (!flag_contracts_definition_check
1328 354 : && !DECL_CONTRACT_WRAPPER (fndecl))
1329 : return;
1330 :
1331 353 : bool do_pre = has_active_preconditions (fndecl);
1332 353 : bool do_post = has_active_postconditions (fndecl);
1333 : /* We should not have reached here with nothing to do... */
1334 353 : gcc_checking_assert (do_pre || do_post);
1335 :
1336 : /* If the function is noexcept, the user's written body will be wrapped in a
1337 : MUST_NOT_THROW expression. In that case we leave the MUST_NOT_THROW in
1338 : place and do our replacement inside it. */
1339 353 : tree fnbody;
1340 353 : if (TYPE_NOEXCEPT_P (TREE_TYPE (fndecl)))
1341 : {
1342 23 : tree m_n_t_expr = expr_first (DECL_SAVED_TREE (fndecl));
1343 23 : gcc_checking_assert (TREE_CODE (m_n_t_expr) == MUST_NOT_THROW_EXPR);
1344 23 : fnbody = TREE_OPERAND (m_n_t_expr, 0);
1345 23 : TREE_OPERAND (m_n_t_expr, 0) = push_stmt_list ();
1346 : }
1347 : else
1348 : {
1349 330 : fnbody = DECL_SAVED_TREE (fndecl);
1350 330 : DECL_SAVED_TREE (fndecl) = push_stmt_list ();
1351 : }
1352 :
1353 : /* Now add the pre and post conditions to the existing function body.
1354 : This copies the approach used for function try blocks. */
1355 353 : tree compound_stmt = begin_compound_stmt (0);
1356 353 : current_binding_level->artificial = true;
1357 :
1358 : /* Do not add locations for the synthesised code. */
1359 353 : location_t loc = UNKNOWN_LOCATION;
1360 :
1361 : /* For other cases, we call a function to process the check. */
1362 :
1363 : /* If we have a pre, but not a post, then just emit that and we are done. */
1364 353 : if (!do_post)
1365 : {
1366 187 : apply_preconditions (fndecl);
1367 187 : add_stmt (fnbody);
1368 187 : finish_compound_stmt (compound_stmt);
1369 187 : return;
1370 : }
1371 :
1372 166 : if (do_pre)
1373 : /* Add a precondition call, if we have one. */
1374 53 : apply_preconditions (fndecl);
1375 166 : tree try_fin = build_stmt (loc, TRY_FINALLY_EXPR, fnbody, NULL_TREE);
1376 166 : add_stmt (try_fin);
1377 166 : TREE_OPERAND (try_fin, 1) = push_stmt_list ();
1378 : /* If we have exceptions, and a function that might throw, then add
1379 : an EH_ELSE clause that allows the exception to propagate upwards
1380 : without encountering the post-condition checks. */
1381 166 : if (flag_exceptions && !type_noexcept_p (TREE_TYPE (fndecl)))
1382 : {
1383 159 : tree eh_else = build_stmt (loc, EH_ELSE_EXPR, NULL_TREE, NULL_TREE);
1384 159 : add_stmt (eh_else);
1385 159 : TREE_OPERAND (eh_else, 0) = push_stmt_list ();
1386 159 : apply_postconditions (fndecl);
1387 159 : TREE_OPERAND (eh_else, 0) = pop_stmt_list (TREE_OPERAND (eh_else, 0));
1388 159 : TREE_OPERAND (eh_else, 1) = void_node;
1389 : }
1390 : else
1391 7 : apply_postconditions (fndecl);
1392 166 : TREE_OPERAND (try_fin, 1) = pop_stmt_list (TREE_OPERAND (try_fin, 1));
1393 166 : finish_compound_stmt (compound_stmt);
1394 : /* The DECL_SAVED_TREE stmt list will be popped by our caller. */
1395 : }
1396 :
1397 : /* Rewrite the condition of contract in place, so that references to SRC's
1398 : parameters are updated to refer to DST's parameters. The postcondition
1399 : result variable is left unchanged.
1400 :
1401 : When declarations are merged, we sometimes need to update contracts to
1402 : refer to new parameters.
1403 :
1404 : If DUPLICATE_P is true, this is called by duplicate_decls to rewrite
1405 : contracts in terms of a new set of parameters. This also preserves the
1406 : references to postcondition results, which are not replaced during
1407 : merging. */
1408 :
1409 : static void
1410 238 : remap_contract (tree src, tree dst, tree contract, bool duplicate_p)
1411 : {
1412 238 : copy_body_data id;
1413 238 : hash_map<tree, tree> decl_map;
1414 :
1415 238 : memset (&id, 0, sizeof (id));
1416 238 : id.src_fn = src;
1417 238 : id.dst_fn = dst;
1418 238 : id.src_cfun = DECL_STRUCT_FUNCTION (src);
1419 238 : id.decl_map = &decl_map;
1420 :
1421 : /* If we're merging contracts, don't copy local variables. */
1422 238 : id.copy_decl = duplicate_p ? retain_decl : copy_decl_no_change;
1423 :
1424 238 : id.transform_call_graph_edges = CB_CGE_DUPLICATE;
1425 238 : id.transform_new_cfg = false;
1426 238 : id.transform_return_to_modify = false;
1427 238 : id.transform_parameter = true;
1428 :
1429 : /* Make sure not to unshare trees behind the front-end's back
1430 : since front-end specific mechanisms may rely on sharing. */
1431 238 : id.regimplify = false;
1432 238 : id.do_not_unshare = true;
1433 238 : id.do_not_fold = true;
1434 :
1435 : /* We're not inside any EH region. */
1436 238 : id.eh_lp_nr = 0;
1437 :
1438 238 : bool do_remap = false;
1439 :
1440 : /* Insert parameter remappings. */
1441 238 : gcc_checking_assert (TREE_CODE (src) == FUNCTION_DECL);
1442 238 : gcc_checking_assert (TREE_CODE (dst) == FUNCTION_DECL);
1443 :
1444 238 : int src_num_artificial_args = num_artificial_parms_for (src);
1445 238 : int dst_num_artificial_args = num_artificial_parms_for (dst);
1446 :
1447 238 : for (tree sp = DECL_ARGUMENTS (src), dp = DECL_ARGUMENTS (dst);
1448 704 : sp || dp;
1449 466 : sp = DECL_CHAIN (sp), dp = DECL_CHAIN (dp))
1450 : {
1451 469 : if (!sp && dp
1452 3 : && TREE_CODE (contract) == POSTCONDITION_STMT
1453 472 : && DECL_CHAIN (dp) == NULL_TREE)
1454 : {
1455 3 : gcc_assert (!duplicate_p);
1456 3 : if (tree result = POSTCONDITION_IDENTIFIER (contract))
1457 : {
1458 3 : gcc_assert (DECL_P (result));
1459 3 : insert_decl_map (&id, result, dp);
1460 3 : do_remap = true;
1461 : }
1462 : break;
1463 : }
1464 466 : gcc_assert (sp && dp);
1465 :
1466 466 : if (sp == dp)
1467 201 : continue;
1468 :
1469 265 : insert_decl_map (&id, sp, dp);
1470 265 : do_remap = true;
1471 :
1472 : /* First artificial arg is *this. We want to remap that. However, we
1473 : want to skip _in_charge param and __vtt_parm. Do so now. */
1474 265 : if (src_num_artificial_args > 0)
1475 : {
1476 80 : while (--src_num_artificial_args,src_num_artificial_args > 0)
1477 0 : sp = DECL_CHAIN (sp);
1478 : }
1479 265 : if (dst_num_artificial_args > 0)
1480 : {
1481 80 : while (--dst_num_artificial_args,dst_num_artificial_args > 0)
1482 0 : dp = DECL_CHAIN (dp);
1483 : }
1484 : }
1485 :
1486 238 : if (!do_remap)
1487 106 : return;
1488 :
1489 132 : walk_tree (&CONTRACT_CONDITION (contract), copy_tree_body_r, &id, NULL);
1490 238 : }
1491 :
1492 : /* Returns a copy of SOURCE contracts where any references to SOURCE's
1493 : PARM_DECLs have been rewritten to the corresponding PARM_DECL in DEST. */
1494 :
1495 : tree
1496 162 : copy_and_remap_contracts (tree dest, tree source,
1497 : contract_match_kind remap_kind)
1498 : {
1499 162 : tree last = NULL_TREE, contracts_copy= NULL_TREE;
1500 162 : tree contracts = get_fn_contract_specifiers (source);
1501 384 : for (; contracts; contracts = TREE_CHAIN (contracts))
1502 : {
1503 224 : if ((remap_kind == cmk_pre
1504 5 : && (TREE_CODE (CONTRACT_STATEMENT (contracts))
1505 : == POSTCONDITION_STMT))
1506 225 : || (remap_kind == cmk_post
1507 0 : && (TREE_CODE (CONTRACT_STATEMENT (contracts))
1508 : == PRECONDITION_STMT)))
1509 2 : continue;
1510 :
1511 : /* The first part is copying of the legacy attribute layout - eventually
1512 : this will go away. */
1513 220 : tree c = copy_node (contracts);
1514 440 : TREE_VALUE (c) = build_tree_list (TREE_PURPOSE (TREE_VALUE (c)),
1515 220 : copy_node (CONTRACT_STATEMENT (c)));
1516 : /* This is the copied contract statement. */
1517 220 : tree stmt = CONTRACT_STATEMENT (c);
1518 :
1519 : /* If we have an erroneous postcondition identifier, we also mark the
1520 : condition as invalid so only need to check that. */
1521 220 : if (CONTRACT_CONDITION (stmt) != error_mark_node)
1522 220 : remap_contract (source, dest, stmt, /*duplicate_p=*/true);
1523 :
1524 220 : if (TREE_CODE (stmt) == POSTCONDITION_STMT)
1525 : {
1526 : /* If we have a postcondition return value placeholder, then
1527 : ensure the copied one has the correct context. */
1528 77 : tree var = POSTCONDITION_IDENTIFIER (stmt);
1529 77 : if (var && var != error_mark_node)
1530 20 : DECL_CONTEXT (var) = dest;
1531 : }
1532 :
1533 220 : if (CONTRACT_COMMENT (stmt) != error_mark_node)
1534 220 : CONTRACT_COMMENT (stmt) = copy_node (CONTRACT_COMMENT (stmt));
1535 :
1536 220 : chainon (last, c);
1537 220 : last = c;
1538 220 : if (!contracts_copy)
1539 162 : contracts_copy = c;
1540 : }
1541 :
1542 162 : return contracts_copy;
1543 : }
1544 :
1545 : /* Set the (maybe) parsed contract specifier LIST for DECL. */
1546 :
1547 : void
1548 1072 : set_fn_contract_specifiers (tree decl, tree list)
1549 : {
1550 1072 : if (!decl || error_operand_p (decl))
1551 0 : return;
1552 :
1553 1072 : bool existed = false;
1554 1072 : contract_decl& rd
1555 1072 : = hash_map_safe_get_or_insert<hm_ggc> (contract_decl_map, decl, &existed);
1556 1072 : if (!existed)
1557 : {
1558 : /* This is the first time we encountered this decl, save the location
1559 : for error messages. This will ensure all error messages refer to the
1560 : contracts used for the function. */
1561 833 : location_t decl_loc = DECL_SOURCE_LOCATION (decl);
1562 833 : location_t cont_end = decl_loc;
1563 833 : if (list)
1564 833 : cont_end = get_contract_end_loc (list);
1565 833 : rd.note_loc = make_location (decl_loc, decl_loc, cont_end);
1566 : }
1567 1072 : rd.contract_specifiers = list;
1568 : }
1569 :
1570 : /* Update the entry for DECL in the map of contract specifiers with the
1571 : contracts in LIST. */
1572 :
1573 : void
1574 272 : update_fn_contract_specifiers (tree decl, tree list)
1575 : {
1576 272 : if (!decl || error_operand_p (decl))
1577 0 : return;
1578 :
1579 272 : bool existed = false;
1580 272 : contract_decl& rd
1581 272 : = hash_map_safe_get_or_insert<hm_ggc> (contract_decl_map, decl, &existed);
1582 272 : gcc_checking_assert (existed);
1583 :
1584 : /* We should only get here when we parse deferred contracts. */
1585 272 : gcc_checking_assert (!contract_any_deferred_p (list));
1586 :
1587 272 : rd.contract_specifiers = list;
1588 : }
1589 :
1590 : /* When a decl is about to be removed, then we need to release its content and
1591 : then take it out of the map. */
1592 :
1593 : void
1594 5215 : remove_decl_with_fn_contracts_specifiers (tree decl)
1595 : {
1596 5350 : if (contract_decl *p = hash_map_safe_get (contract_decl_map, decl))
1597 : {
1598 109 : p->contract_specifiers = NULL_TREE;
1599 109 : contract_decl_map->remove (decl);
1600 : }
1601 5215 : }
1602 :
1603 : /* If this function has contract specifiers, then remove them, but leave the
1604 : function registered. */
1605 :
1606 : void
1607 2345 : remove_fn_contract_specifiers (tree decl)
1608 : {
1609 2375 : if (contract_decl *p = hash_map_safe_get (contract_decl_map, decl))
1610 : {
1611 30 : p->contract_specifiers = NULL_TREE;
1612 : }
1613 2345 : }
1614 :
1615 : /* Get the contract specifier list for this DECL if there is one. */
1616 :
1617 : tree
1618 466410074 : get_fn_contract_specifiers (tree decl)
1619 : {
1620 466658967 : if (contract_decl *p = hash_map_safe_get (contract_decl_map, decl))
1621 5946 : return p->contract_specifiers;
1622 : return NULL_TREE;
1623 : }
1624 :
1625 : /* A subroutine of duplicate_decls. Diagnose issues in the redeclaration of
1626 : guarded functions. */
1627 :
1628 : void
1629 18635012 : check_redecl_contract (tree newdecl, tree olddecl)
1630 : {
1631 18635012 : if (!flag_contracts)
1632 : return;
1633 :
1634 7178 : if (TREE_CODE (newdecl) == TEMPLATE_DECL)
1635 2407 : newdecl = DECL_TEMPLATE_RESULT (newdecl);
1636 7178 : if (TREE_CODE (olddecl) == TEMPLATE_DECL)
1637 2407 : olddecl = DECL_TEMPLATE_RESULT (olddecl);
1638 :
1639 7178 : tree new_contracts = get_fn_contract_specifiers (newdecl);
1640 7178 : tree old_contracts = get_fn_contract_specifiers (olddecl);
1641 :
1642 7178 : if (!old_contracts && !new_contracts)
1643 : return;
1644 :
1645 : /* We should always be comparing with the 'first' declaration which should
1646 : have been recorded already (if it has contract specifiers). However
1647 : if the new decl is trying to add contracts, that is an error and we do
1648 : not want to create a map entry yet. */
1649 131 : contract_decl *rdp = hash_map_safe_get (contract_decl_map, olddecl);
1650 131 : gcc_checking_assert(rdp || !old_contracts);
1651 :
1652 131 : location_t new_loc = DECL_SOURCE_LOCATION (newdecl);
1653 131 : if (new_contracts && !old_contracts)
1654 : {
1655 10 : auto_diagnostic_group d;
1656 : /* If a re-declaration has contracts, they must be the same as those
1657 : that appear on the first declaration seen (they cannot be added). */
1658 10 : location_t cont_end = get_contract_end_loc (new_contracts);
1659 10 : cont_end = make_location (new_loc, new_loc, cont_end);
1660 10 : error_at (cont_end, "declaration adds contracts to %q#D", olddecl);
1661 10 : inform (DECL_SOURCE_LOCATION (olddecl), "first declared here");
1662 10 : return;
1663 10 : }
1664 :
1665 121 : if (old_contracts && !new_contracts)
1666 : /* We allow re-declarations to omit contracts declared on the initial decl.
1667 : In fact, this is required if the conditions contain lambdas. Check if
1668 : all the parameters are correctly const qualified. */
1669 79 : check_postconditions_in_redecl (olddecl, newdecl);
1670 42 : else if (old_contracts && new_contracts
1671 42 : && !contract_any_deferred_p (old_contracts)
1672 38 : && contract_any_deferred_p (new_contracts)
1673 42 : && DECL_UNIQUE_FRIEND_P (newdecl))
1674 : {
1675 : /* Put the defered contracts on the olddecl so we parse it when
1676 : we can. */
1677 0 : set_fn_contract_specifiers (olddecl, old_contracts);
1678 : }
1679 42 : else if (contract_any_deferred_p (old_contracts)
1680 42 : || contract_any_deferred_p (new_contracts))
1681 : {
1682 : /* TODO: ignore these and figure out how to process them later. */
1683 : /* Note that a friend declaration has deferred contracts, but the
1684 : declaration of the same function outside the class definition
1685 : doesn't. */
1686 : }
1687 : else
1688 : {
1689 38 : gcc_checking_assert (old_contracts);
1690 38 : location_t cont_end = get_contract_end_loc (new_contracts);
1691 38 : cont_end = make_location (new_loc, new_loc, cont_end);
1692 : /* We have two sets - they should match or we issue a diagnostic. */
1693 38 : match_contract_specifiers (rdp->note_loc, old_contracts,
1694 : cont_end, new_contracts);
1695 : }
1696 :
1697 : return;
1698 : }
1699 :
1700 : /* Update the contracts of DEST to match the argument names from contracts
1701 : of SRC. When we merge two declarations in duplicate_decls, we preserve the
1702 : arguments from the new declaration, if the new declaration is a
1703 : definition. We need to update the contracts accordingly. */
1704 :
1705 : void
1706 11593278 : update_contract_arguments (tree srcdecl, tree destdecl)
1707 : {
1708 11593278 : tree src_contracts = get_fn_contract_specifiers (srcdecl);
1709 11593278 : tree dest_contracts = get_fn_contract_specifiers (destdecl);
1710 :
1711 11593278 : if (!src_contracts && !dest_contracts)
1712 : return;
1713 :
1714 : /* Check if src even has contracts. It is possible that a redeclaration
1715 : does not have contracts. Is this is the case, first apply contracts
1716 : to src. */
1717 85 : if (!src_contracts)
1718 : {
1719 59 : if (contract_any_deferred_p (dest_contracts))
1720 : {
1721 0 : set_fn_contract_specifiers (srcdecl, dest_contracts);
1722 : /* Nothing more to do here. */
1723 0 : return;
1724 : }
1725 : else
1726 59 : set_fn_contract_specifiers
1727 59 : (srcdecl, copy_and_remap_contracts (srcdecl, destdecl));
1728 : }
1729 :
1730 : /* For deferred contracts, we currently copy the tokens from the redeclaration
1731 : onto the decl that will be preserved. This is not ideal because the
1732 : redeclaration may have erroneous contracts.
1733 : For non deferred contracts we currently do copy and remap, which is doing
1734 : more than we need. */
1735 85 : if (contract_any_deferred_p (src_contracts))
1736 4 : set_fn_contract_specifiers (destdecl, src_contracts);
1737 : else
1738 : {
1739 : /* Temporarily rename the arguments to get the right mapping. */
1740 81 : tree tmp_arguments = DECL_ARGUMENTS (destdecl);
1741 81 : DECL_ARGUMENTS (destdecl) = DECL_ARGUMENTS (srcdecl);
1742 81 : set_fn_contract_specifiers (destdecl,
1743 : copy_and_remap_contracts (destdecl, srcdecl));
1744 81 : DECL_ARGUMENTS (destdecl) = tmp_arguments;
1745 : }
1746 : }
1747 :
1748 : /* Checks if a contract check wrapper is needed for fndecl. */
1749 :
1750 : static bool
1751 217 : should_contract_wrap_call (bool do_pre, bool do_post)
1752 : {
1753 : /* Only if the target function actually has any contracts. */
1754 0 : if (!do_pre && !do_post)
1755 : return false;
1756 :
1757 :
1758 217 : return ((flag_contract_client_check > 1)
1759 217 : || ((flag_contract_client_check > 0)
1760 : && do_pre));
1761 : }
1762 :
1763 : /* Possibly replace call with a call to a wrapper function which
1764 : will do the contracts check required around a CALL to FNDECL. */
1765 :
1766 : tree
1767 225770260 : maybe_contract_wrap_call (tree fndecl, tree call)
1768 : {
1769 : /* We can be called from build_cxx_call without a known callee. */
1770 225770260 : if (!fndecl)
1771 : return call;
1772 :
1773 218364170 : if (error_operand_p (fndecl) || !call || call == error_mark_node)
1774 0 : return error_mark_node;
1775 :
1776 218364170 : if (!handle_contracts_p (fndecl))
1777 : return call;
1778 :
1779 217 : bool do_pre = has_active_preconditions (fndecl);
1780 217 : bool do_post = has_active_postconditions (fndecl);
1781 :
1782 : /* Check if we need a wrapper. */
1783 225770458 : if (!should_contract_wrap_call (do_pre, do_post))
1784 : return call;
1785 :
1786 : /* Build the declaration of the wrapper, if we need to. */
1787 22 : tree wrapdecl = get_or_create_contract_wrapper_function (fndecl);
1788 :
1789 22 : unsigned nargs = call_expr_nargs (call);
1790 22 : vec<tree, va_gc> *argwrap;
1791 22 : vec_alloc (argwrap, nargs);
1792 :
1793 22 : tree arg;
1794 22 : call_expr_arg_iterator iter;
1795 92 : FOR_EACH_CALL_EXPR_ARG (arg, iter, call)
1796 48 : argwrap->quick_push (arg);
1797 :
1798 22 : tree wrapcall = build_call_expr_loc_vec (DECL_SOURCE_LOCATION (wrapdecl),
1799 : wrapdecl, argwrap);
1800 :
1801 22 : return wrapcall;
1802 : }
1803 :
1804 : /* Map traversal callback to define a wrapper function.
1805 : This generates code for client-side contract check wrappers and the
1806 : noexcept wrapper around the contract violation handler. */
1807 :
1808 : bool
1809 48 : define_contract_wrapper_func (const tree& fndecl, const tree& wrapdecl, void*)
1810 : {
1811 : /* If we already built this function on a previous pass, then do nothing. */
1812 48 : if (DECL_INITIAL (wrapdecl) && DECL_INITIAL (wrapdecl) != error_mark_node)
1813 : return true;
1814 :
1815 22 : gcc_checking_assert (!DECL_HAS_CONTRACTS_P (wrapdecl));
1816 : /* We check postconditions if postcondition checks are enabled for clients.
1817 : We should not get here unless there are some checks to make. */
1818 22 : bool check_post = flag_contract_client_check > 1;
1819 : /* For wrappers on CDTORs we need to refer to the original contracts,
1820 : when the wrapper is around a clone. */
1821 44 : set_fn_contract_specifiers ( wrapdecl,
1822 22 : copy_and_remap_contracts (wrapdecl, DECL_ORIGIN (fndecl),
1823 : check_post? cmk_all : cmk_pre));
1824 :
1825 22 : start_preparsed_function (wrapdecl, /*DECL_ATTRIBUTES*/NULL_TREE,
1826 : SF_DEFAULT | SF_PRE_PARSED);
1827 22 : tree body = begin_function_body ();
1828 22 : tree compound_stmt = begin_compound_stmt (BCS_FN_BODY);
1829 :
1830 22 : vec<tree, va_gc> * args = build_arg_list (wrapdecl);
1831 :
1832 : /* We do not support contracts on virtual functions yet. */
1833 22 : gcc_checking_assert (!DECL_IOBJ_MEMBER_FUNCTION_P (fndecl)
1834 : || !DECL_VIRTUAL_P (fndecl));
1835 :
1836 22 : tree call = build_thunk_like_call (fndecl, args->length (), args->address ());
1837 :
1838 22 : finish_return_stmt (call);
1839 :
1840 22 : finish_compound_stmt (compound_stmt);
1841 22 : finish_function_body (body);
1842 22 : expand_or_defer_fn (finish_function (/*inline_p=*/false));
1843 22 : return true;
1844 : }
1845 :
1846 : /* If any wrapper functions have been declared, emit their definition.
1847 : This might be called multiple times, as we instantiate functions. When
1848 : the processing here adds more wrappers, then flag to the caller that
1849 : possible additional instantiations should be considered.
1850 : Once instantiations are complete, this will be called with done == true. */
1851 :
1852 : bool
1853 312 : emit_contract_wrapper_func (bool done)
1854 : {
1855 312 : if (!decl_wrapper_fn || decl_wrapper_fn->is_empty ())
1856 : return false;
1857 26 : size_t start_elements = decl_wrapper_fn->elements ();
1858 74 : decl_wrapper_fn->traverse<void *, define_contract_wrapper_func>(NULL);
1859 26 : bool more = decl_wrapper_fn->elements () > start_elements;
1860 26 : if (done)
1861 11 : decl_wrapper_fn->empty ();
1862 11 : gcc_checking_assert (!done || !more);
1863 : return more;
1864 : }
1865 :
1866 : /* Mark most of a contract as being invalid. */
1867 :
1868 : tree
1869 12 : invalidate_contract (tree contract)
1870 : {
1871 12 : if (TREE_CODE (contract) == POSTCONDITION_STMT
1872 12 : && POSTCONDITION_IDENTIFIER (contract))
1873 12 : POSTCONDITION_IDENTIFIER (contract) = error_mark_node;
1874 12 : CONTRACT_CONDITION (contract) = error_mark_node;
1875 12 : CONTRACT_COMMENT (contract) = error_mark_node;
1876 12 : return contract;
1877 : }
1878 :
1879 : /* Returns an invented parameter declaration of the form 'TYPE ID' for the
1880 : purpose of parsing the postcondition.
1881 :
1882 : We use a PARM_DECL instead of a VAR_DECL so that tsubst forces a lookup
1883 : in local specializations when we instantiate these things later. */
1884 :
1885 : tree
1886 131 : make_postcondition_variable (cp_expr id, tree type)
1887 : {
1888 131 : if (id == error_mark_node)
1889 : return id;
1890 131 : gcc_checking_assert (scope_chain && scope_chain->bindings
1891 : && scope_chain->bindings->kind == sk_contract);
1892 :
1893 131 : tree decl = build_lang_decl (PARM_DECL, id, type);
1894 131 : DECL_ARTIFICIAL (decl) = true;
1895 131 : DECL_SOURCE_LOCATION (decl) = id.get_location ();
1896 131 : return pushdecl (decl);
1897 : }
1898 :
1899 : /* As above, except that the type is unknown. */
1900 :
1901 : tree
1902 79 : make_postcondition_variable (cp_expr id)
1903 : {
1904 79 : return make_postcondition_variable (id, make_auto ());
1905 : }
1906 :
1907 : /* Check that the TYPE is valid for a named postcondition variable on
1908 : function decl FNDECL. Emit a diagnostic if it is not. Returns TRUE if
1909 : the result is OK and false otherwise. */
1910 :
1911 : bool
1912 205 : check_postcondition_result (tree fndecl, tree type, location_t loc)
1913 : {
1914 : /* Do not be confused by targetm.cxx.cdtor_return_this ();
1915 : conceptually, cdtors have no return value. */
1916 205 : if (VOID_TYPE_P (type)
1917 390 : || DECL_CONSTRUCTOR_P (fndecl)
1918 400 : || DECL_DESTRUCTOR_P (fndecl))
1919 : {
1920 30 : error_at (loc,
1921 20 : DECL_CONSTRUCTOR_P (fndecl)
1922 : ? G_("constructor does not return a value to test")
1923 8 : : DECL_DESTRUCTOR_P (fndecl)
1924 8 : ? G_("destructor does not return a value to test")
1925 : : G_("function does not return a value to test"));
1926 10 : return false;
1927 : }
1928 :
1929 : return true;
1930 : }
1931 :
1932 : /* Instantiate each postcondition with the return type to finalize the
1933 : contract specifiers on a function decl FNDECL. */
1934 :
1935 : void
1936 1062 : rebuild_postconditions (tree fndecl)
1937 : {
1938 1062 : if (!fndecl || fndecl == error_mark_node)
1939 : return;
1940 :
1941 1062 : tree type = TREE_TYPE (TREE_TYPE (fndecl));
1942 :
1943 : /* If the return type is undeduced, defer until later. */
1944 1062 : if (TREE_CODE (type) == TEMPLATE_TYPE_PARM)
1945 : return;
1946 :
1947 1004 : tree contract_spec = get_fn_contract_specifiers (fndecl);
1948 2573 : for (; contract_spec ; contract_spec = TREE_CHAIN (contract_spec))
1949 : {
1950 1909 : tree contract = TREE_VALUE (TREE_VALUE (contract_spec));
1951 1909 : if (TREE_CODE (contract) != POSTCONDITION_STMT)
1952 1454 : continue;
1953 1241 : tree condition = CONTRACT_CONDITION (contract);
1954 1241 : if (!condition || condition == error_mark_node)
1955 2 : continue;
1956 :
1957 : /* If any conditions are deferred, they're all deferred. Note that
1958 : we don't have to instantiate postconditions in that case because
1959 : the type is available through the declaration. */
1960 1239 : if (TREE_CODE (condition) == DEFERRED_PARSE)
1961 340 : return;
1962 :
1963 899 : tree oldvar = POSTCONDITION_IDENTIFIER (contract);
1964 899 : if (!oldvar)
1965 780 : continue;
1966 :
1967 119 : gcc_checking_assert (!DECL_CONTEXT (oldvar)
1968 : || DECL_CONTEXT (oldvar) == fndecl);
1969 119 : DECL_CONTEXT (oldvar) = fndecl;
1970 :
1971 : /* Check the postcondition variable. */
1972 119 : location_t loc = DECL_SOURCE_LOCATION (oldvar);
1973 119 : if (!check_postcondition_result (fndecl, type, loc))
1974 : {
1975 4 : invalidate_contract (contract);
1976 4 : continue;
1977 : }
1978 :
1979 : /* "Instantiate" the result variable using the known type. */
1980 115 : tree newvar = copy_node (oldvar);
1981 115 : TREE_TYPE (newvar) = type;
1982 :
1983 : /* Make parameters and result available for substitution. */
1984 115 : local_specialization_stack stack (lss_copy);
1985 289 : for (tree t = DECL_ARGUMENTS (fndecl); t != NULL_TREE; t = TREE_CHAIN (t))
1986 174 : register_local_identity (t);
1987 115 : register_local_specialization (newvar, oldvar);
1988 :
1989 115 : begin_scope (sk_contract, fndecl);
1990 115 : bool old_pc = processing_postcondition;
1991 115 : processing_postcondition = true;
1992 :
1993 115 : condition = tsubst_expr (condition, make_tree_vec (0),
1994 : tf_warning_or_error, fndecl);
1995 :
1996 : /* Update the contract condition and result. */
1997 115 : POSTCONDITION_IDENTIFIER (contract) = newvar;
1998 115 : CONTRACT_CONDITION (contract) = finish_contract_condition (condition);
1999 115 : processing_postcondition = old_pc;
2000 115 : gcc_checking_assert (scope_chain && scope_chain->bindings
2001 : && scope_chain->bindings->kind == sk_contract);
2002 115 : pop_bindings_and_leave_scope ();
2003 115 : }
2004 : }
2005 :
2006 : /* Make a string of the contract condition, if it is available. */
2007 :
2008 : static tree
2009 996 : build_comment (cp_expr condition)
2010 : {
2011 : /* Try to get the actual source text for the condition; if that fails pretty
2012 : print the resulting tree. */
2013 996 : char *str = get_source_text_between (global_dc->get_file_cache (),
2014 : condition.get_start (),
2015 : condition.get_finish ());
2016 996 : if (!str)
2017 : {
2018 1 : const char *str = expr_to_string (condition);
2019 1 : return build_string_literal (strlen (str) + 1, str);
2020 : }
2021 :
2022 995 : tree t = build_string_literal (strlen (str) + 1, str);
2023 995 : free (str);
2024 995 : return t;
2025 : }
2026 :
2027 : /* Build a contract statement. */
2028 :
2029 : tree
2030 1023 : grok_contract (tree contract_spec, tree mode, tree result, cp_expr condition,
2031 : location_t loc)
2032 : {
2033 1023 : if (condition == error_mark_node)
2034 : return error_mark_node;
2035 :
2036 1006 : tree_code code;
2037 1006 : contract_assertion_kind kind = CAK_INVALID;
2038 1006 : if (id_equal (contract_spec, "contract_assert"))
2039 : {
2040 : code = ASSERTION_STMT;
2041 : kind = CAK_ASSERT;
2042 : }
2043 929 : else if (id_equal (contract_spec, "pre"))
2044 : {
2045 : code = PRECONDITION_STMT;
2046 : kind = CAK_PRE;
2047 : }
2048 523 : else if (id_equal (contract_spec,"post"))
2049 : {
2050 : code = POSTCONDITION_STMT;
2051 : kind = CAK_POST;
2052 : }
2053 : else
2054 0 : gcc_unreachable ();
2055 :
2056 : /* Build the contract. The condition is added later. In the case that
2057 : the contract is deferred, result an plain identifier, not a result
2058 : variable. */
2059 523 : tree contract;
2060 523 : if (code != POSTCONDITION_STMT)
2061 483 : contract = build5_loc (loc, code, void_type_node, mode,
2062 : NULL_TREE, NULL_TREE, NULL_TREE, NULL_TREE);
2063 : else
2064 : {
2065 523 : contract = build_nt (code, mode, NULL_TREE, NULL_TREE,
2066 : NULL_TREE, NULL_TREE, result);
2067 523 : TREE_TYPE (contract) = void_type_node;
2068 523 : SET_EXPR_LOCATION (contract, loc);
2069 : }
2070 :
2071 : /* Determine the assertion kind. */
2072 1006 : CONTRACT_ASSERTION_KIND (contract) = build_int_cst (uint16_type_node, kind);
2073 :
2074 : /* Determine the evaluation semantic. This is now an override, so that if
2075 : not set we will get the default (currently enforce). */
2076 1006 : CONTRACT_EVALUATION_SEMANTIC (contract)
2077 2012 : = build_int_cst (uint16_type_node, (uint16_t)
2078 1006 : flag_contract_evaluation_semantic);
2079 :
2080 : /* If the contract is deferred, don't do anything with the condition. */
2081 1006 : if (TREE_CODE (condition) == DEFERRED_PARSE)
2082 : {
2083 509 : CONTRACT_CONDITION (contract) = condition;
2084 509 : return contract;
2085 : }
2086 :
2087 : /* Generate the comment from the original condition. */
2088 497 : CONTRACT_COMMENT (contract) = build_comment (condition);
2089 :
2090 : /* The condition is converted to bool. */
2091 497 : condition = finish_contract_condition (condition);
2092 :
2093 497 : if (condition == error_mark_node)
2094 : return error_mark_node;
2095 :
2096 495 : CONTRACT_CONDITION (contract) = condition;
2097 :
2098 495 : return contract;
2099 : }
2100 :
2101 : /* Build the contract specifier where IDENTIFIER is one of 'pre',
2102 : 'post' or 'assert' and CONTRACT is the underlying statement. */
2103 :
2104 : tree
2105 928 : finish_contract_specifier (tree identifier, tree contract)
2106 : {
2107 928 : if (contract == error_mark_node)
2108 : return error_mark_node;
2109 :
2110 928 : tree contract_spec = build_tree_list (build_tree_list (NULL_TREE, identifier),
2111 : build_tree_list (NULL_TREE, contract));
2112 :
2113 : /* Mark the contract as dependent if the condition is dependent. */
2114 928 : tree condition = CONTRACT_CONDITION (contract);
2115 928 : if (TREE_CODE (condition) != DEFERRED_PARSE
2116 928 : && value_dependent_expression_p (condition))
2117 87 : ATTR_IS_DEPENDENT (contract_spec) = true;
2118 :
2119 : return contract_spec;
2120 : }
2121 :
2122 : /* Update condition of a late-parsed contract and postcondition variable,
2123 : if any. */
2124 :
2125 : void
2126 499 : update_late_contract (tree contract, tree result, cp_expr condition)
2127 : {
2128 499 : if (TREE_CODE (contract) == POSTCONDITION_STMT)
2129 335 : POSTCONDITION_IDENTIFIER (contract) = result;
2130 :
2131 : /* Generate the comment from the original condition. */
2132 499 : CONTRACT_COMMENT (contract) = build_comment (condition);
2133 :
2134 : /* The condition is converted to bool. */
2135 499 : condition = finish_contract_condition (condition);
2136 499 : CONTRACT_CONDITION (contract) = condition;
2137 499 : }
2138 :
2139 : /* Returns the precondition funtion for FNDECL, or null if not set. */
2140 :
2141 : tree
2142 1249326 : get_precondition_function (tree fndecl)
2143 : {
2144 1249326 : gcc_checking_assert (fndecl);
2145 1249326 : tree *result = hash_map_safe_get (decl_pre_fn, fndecl);
2146 53 : return result ? *result : NULL_TREE;
2147 : }
2148 :
2149 : /* Returns the postcondition funtion for FNDECL, or null if not set. */
2150 :
2151 : tree
2152 1249328 : get_postcondition_function (tree fndecl)
2153 : {
2154 1249328 : gcc_checking_assert (fndecl);
2155 1249328 : tree *result = hash_map_safe_get (decl_post_fn, fndecl);
2156 40 : return result ? *result : NULL_TREE;
2157 : }
2158 :
2159 : /* Set the PRE and POST functions for FNDECL. Note that PRE and POST can
2160 : be null in this case. If so the functions are not recorded. Used by the
2161 : modules code. */
2162 :
2163 : void
2164 415421 : set_contract_functions (tree fndecl, tree pre, tree post)
2165 : {
2166 415421 : if (pre)
2167 0 : set_precondition_function (fndecl, pre);
2168 :
2169 415421 : if (post)
2170 0 : set_postcondition_function (fndecl, post);
2171 415421 : }
2172 :
2173 :
2174 : /* We're compiling the pre/postcondition function CONDFN; remap any FN
2175 : contracts that match CODE and emit them. */
2176 :
2177 : static void
2178 16 : remap_and_emit_conditions (tree fn, tree condfn, tree_code code)
2179 : {
2180 16 : gcc_assert (code == PRECONDITION_STMT || code == POSTCONDITION_STMT);
2181 16 : tree contract_spec = get_fn_contract_specifiers (fn);
2182 38 : for (; contract_spec; contract_spec = TREE_CHAIN (contract_spec))
2183 : {
2184 22 : tree contract = CONTRACT_STATEMENT (contract_spec);
2185 22 : if (TREE_CODE (contract) == code)
2186 : {
2187 18 : contract = copy_node (contract);
2188 18 : if (CONTRACT_CONDITION (contract) != error_mark_node)
2189 18 : remap_contract (fn, condfn, contract, /*duplicate_p=*/false);
2190 18 : emit_contract_statement (contract);
2191 : }
2192 : }
2193 16 : }
2194 :
2195 : /* Finish up the pre & post function definitions for a guarded FNDECL,
2196 : and compile those functions all the way to assembler language output. */
2197 :
2198 : void
2199 166164434 : finish_function_outlined_contracts (tree fndecl)
2200 : {
2201 : /* If the guarded func is either already decided to be ill-formed or is
2202 : not yet complete return early. */
2203 166164434 : if (error_operand_p (fndecl)
2204 166164434 : || !DECL_INITIAL (fndecl)
2205 332328868 : || DECL_INITIAL (fndecl) == error_mark_node)
2206 : return;
2207 :
2208 : /* If there are no contracts here, or we're building them in-line then we
2209 : do not need to build the outlined functions. */
2210 166164344 : if (!handle_contracts_p (fndecl)
2211 166164344 : || !flag_contract_checks_outlined)
2212 : return;
2213 :
2214 : /* If this is not a client side check and definition side checks are
2215 : disabled, do nothing. */
2216 15 : if (!flag_contracts_definition_check
2217 15 : && !DECL_CONTRACT_WRAPPER (fndecl))
2218 : return;
2219 :
2220 : /* If either the pre or post functions are bad, don't bother emitting
2221 : any contracts. The program is already ill-formed. */
2222 15 : tree pre = DECL_PRE_FN (fndecl);
2223 15 : tree post = DECL_POST_FN (fndecl);
2224 15 : if (pre == error_mark_node || post == error_mark_node)
2225 : return;
2226 :
2227 : /* We are generating code, deferred parses should be complete. */
2228 15 : tree contract_spec = get_fn_contract_specifiers (fndecl);
2229 15 : gcc_checking_assert (!contract_any_deferred_p (contract_spec));
2230 :
2231 15 : int flags = SF_DEFAULT | SF_PRE_PARSED;
2232 :
2233 15 : if (pre && !DECL_INITIAL (pre))
2234 : {
2235 8 : DECL_PENDING_INLINE_P (pre) = false;
2236 8 : start_preparsed_function (pre, DECL_ATTRIBUTES (pre), flags);
2237 8 : remap_and_emit_conditions (fndecl, pre, PRECONDITION_STMT);
2238 8 : finish_return_stmt (NULL_TREE);
2239 8 : pre = finish_function (false);
2240 8 : expand_or_defer_fn (pre);
2241 : }
2242 :
2243 15 : if (post && !DECL_INITIAL (post))
2244 : {
2245 8 : DECL_PENDING_INLINE_P (post) = false;
2246 8 : start_preparsed_function (post, DECL_ATTRIBUTES (post), flags);
2247 8 : remap_and_emit_conditions (fndecl, post, POSTCONDITION_STMT);
2248 8 : gcc_checking_assert (VOID_TYPE_P (TREE_TYPE (TREE_TYPE (post))));
2249 8 : finish_return_stmt (NULL_TREE);
2250 8 : post = finish_function (false);
2251 8 : expand_or_defer_fn (post);
2252 : }
2253 : }
2254 :
2255 : /* ===== Code generation ===== */
2256 :
2257 : /* Insert a BUILT_IN_OBSERVABLE_CHECKPOINT epoch marker. */
2258 :
2259 : static void
2260 280 : emit_builtin_observable_checkpoint ()
2261 : {
2262 280 : tree fn = builtin_decl_explicit (BUILT_IN_OBSERVABLE_CHKPT);
2263 280 : releasing_vec vec;
2264 280 : fn = finish_call_expr (fn, &vec, false, false, tf_warning_or_error);
2265 280 : finish_expr_stmt (fn);
2266 280 : }
2267 :
2268 : /* Shared code between TU-local wrappers for the violation handler. */
2269 :
2270 : static tree
2271 208 : declare_one_violation_handler_wrapper (tree fn_name, tree fn_type,
2272 : tree p1_type, tree p2_type)
2273 : {
2274 208 : location_t loc = BUILTINS_LOCATION;
2275 208 : tree fn_decl = build_lang_decl_loc (loc, FUNCTION_DECL, fn_name, fn_type);
2276 208 : DECL_CONTEXT (fn_decl) = FROB_CONTEXT (global_namespace);
2277 208 : DECL_ARTIFICIAL (fn_decl) = true;
2278 208 : DECL_INITIAL (fn_decl) = error_mark_node;
2279 : /* Let the start function code fill in the result decl. */
2280 208 : DECL_RESULT (fn_decl) = NULL_TREE;
2281 : /* Two args violation ref, dynamic info. */
2282 208 : tree parms = cp_build_parm_decl (fn_decl, NULL_TREE, p1_type);
2283 208 : TREE_USED (parms) = true;
2284 208 : DECL_READ_P (parms) = true;
2285 208 : tree p2 = cp_build_parm_decl (fn_decl, NULL_TREE, p2_type);
2286 208 : TREE_USED (p2) = true;
2287 208 : DECL_READ_P (p2) = true;
2288 208 : DECL_CHAIN (parms) = p2;
2289 208 : DECL_ARGUMENTS (fn_decl) = parms;
2290 : /* Make this function internal. */
2291 208 : TREE_PUBLIC (fn_decl) = false;
2292 208 : DECL_EXTERNAL (fn_decl) = false;
2293 208 : DECL_WEAK (fn_decl) = false;
2294 208 : return fn_decl;
2295 : }
2296 :
2297 : static GTY(()) tree tu_has_violation = NULL_TREE;
2298 : static GTY(()) tree tu_has_violation_exception = NULL_TREE;
2299 :
2300 : static void
2301 608 : declare_violation_handler_wrappers ()
2302 : {
2303 608 : if (tu_has_violation && tu_has_violation_exception)
2304 608 : return;
2305 :
2306 104 : iloc_sentinel ils (input_location);
2307 104 : input_location = BUILTINS_LOCATION;
2308 104 : tree v_obj_type = builtin_contract_violation_type;
2309 104 : v_obj_type = cp_build_qualified_type (v_obj_type, TYPE_QUAL_CONST);
2310 104 : v_obj_type = cp_build_reference_type (v_obj_type, /*rval*/false);
2311 104 : tree fn_type = build_function_type_list (void_type_node, v_obj_type,
2312 : uint16_type_node, NULL_TREE);
2313 104 : tree fn_name = get_identifier ("__tu_has_violation_exception");
2314 104 : tu_has_violation_exception
2315 104 : = declare_one_violation_handler_wrapper (fn_name, fn_type, v_obj_type,
2316 : uint16_type_node);
2317 104 : fn_name = get_identifier ("__tu_has_violation");
2318 104 : tu_has_violation
2319 104 : = declare_one_violation_handler_wrapper (fn_name, fn_type, v_obj_type,
2320 : uint16_type_node);
2321 104 : }
2322 :
2323 : static GTY(()) tree tu_terminate_wrapper = NULL_TREE;
2324 :
2325 : /* Declare a noipa wrapper around the call to std::terminate */
2326 :
2327 : static tree
2328 609 : declare_terminate_wrapper ()
2329 : {
2330 609 : if (tu_terminate_wrapper)
2331 : return tu_terminate_wrapper;
2332 :
2333 105 : iloc_sentinel ils (input_location);
2334 105 : input_location = BUILTINS_LOCATION;
2335 :
2336 105 : tree fn_type = build_function_type_list (void_type_node, NULL_TREE);
2337 105 : if (!TREE_NOTHROW (terminate_fn))
2338 0 : fn_type = build_exception_variant (fn_type, noexcept_true_spec);
2339 105 : tree fn_name = get_identifier ("__tu_terminate_wrapper");
2340 :
2341 105 : tu_terminate_wrapper
2342 105 : = build_lang_decl_loc (input_location, FUNCTION_DECL, fn_name, fn_type);
2343 105 : DECL_CONTEXT (tu_terminate_wrapper) = FROB_CONTEXT(global_namespace);
2344 105 : DECL_ARTIFICIAL (tu_terminate_wrapper) = true;
2345 105 : DECL_INITIAL (tu_terminate_wrapper) = error_mark_node;
2346 : /* Let the start function code fill in the result decl. */
2347 105 : DECL_RESULT (tu_terminate_wrapper) = NULL_TREE;
2348 :
2349 : /* Make this function internal. */
2350 105 : TREE_PUBLIC (tu_terminate_wrapper) = false;
2351 105 : DECL_EXTERNAL (tu_terminate_wrapper) = false;
2352 105 : DECL_WEAK (tu_terminate_wrapper) = false;
2353 :
2354 105 : DECL_ATTRIBUTES (tu_terminate_wrapper)
2355 105 : = tree_cons (get_identifier ("noipa"), NULL, NULL_TREE);
2356 105 : cplus_decl_attributes (&tu_terminate_wrapper,
2357 105 : DECL_ATTRIBUTES (tu_terminate_wrapper), 0);
2358 105 : return tu_terminate_wrapper;
2359 105 : }
2360 :
2361 : /* Define a noipa wrapper around the call to std::terminate */
2362 :
2363 : static void
2364 105 : build_terminate_wrapper ()
2365 : {
2366 : /* We should not be trying to build this if we never used it. */
2367 105 : gcc_checking_assert (tu_terminate_wrapper);
2368 :
2369 105 : start_preparsed_function (tu_terminate_wrapper,
2370 105 : DECL_ATTRIBUTES(tu_terminate_wrapper),
2371 : SF_DEFAULT | SF_PRE_PARSED);
2372 105 : tree body = begin_function_body ();
2373 105 : tree compound_stmt = begin_compound_stmt (BCS_FN_BODY);
2374 105 : finish_expr_stmt (build_call_a (terminate_fn, 0, nullptr));
2375 105 : finish_return_stmt (NULL_TREE);
2376 105 : finish_compound_stmt (compound_stmt);
2377 105 : finish_function_body (body);
2378 105 : tu_terminate_wrapper = finish_function (false);
2379 105 : expand_or_defer_fn (tu_terminate_wrapper);
2380 105 : }
2381 :
2382 : /* Lookup a name in std::contracts, or inject it. */
2383 :
2384 : static tree
2385 84 : lookup_std_contracts_type (tree name_id)
2386 : {
2387 84 : tree id_ns = get_identifier ("contracts");
2388 84 : tree ns = lookup_qualified_name (std_node, id_ns);
2389 :
2390 84 : tree res_type = error_mark_node;
2391 84 : if (TREE_CODE (ns) == NAMESPACE_DECL)
2392 2 : res_type = lookup_qualified_name
2393 2 : (ns, name_id, LOOK_want::TYPE | LOOK_want::HIDDEN_FRIEND);
2394 :
2395 84 : if (TREE_CODE (res_type) == TYPE_DECL)
2396 2 : res_type = TREE_TYPE (res_type);
2397 : else
2398 : {
2399 82 : push_nested_namespace (std_node);
2400 82 : push_namespace (id_ns, /*inline*/false);
2401 82 : res_type = make_class_type (RECORD_TYPE);
2402 82 : create_implicit_typedef (name_id, res_type);
2403 82 : DECL_SOURCE_LOCATION (TYPE_NAME (res_type)) = BUILTINS_LOCATION;
2404 82 : DECL_CONTEXT (TYPE_NAME (res_type)) = current_namespace;
2405 82 : pushdecl_namespace_level (TYPE_NAME (res_type), /*hidden*/true);
2406 82 : pop_namespace ();
2407 82 : pop_nested_namespace (std_node);
2408 : }
2409 84 : return res_type;
2410 : }
2411 :
2412 : /* Return handle_contract_violation (), declaring it if needed. */
2413 :
2414 : static tree
2415 208 : declare_handle_contract_violation ()
2416 : {
2417 : /* We may need to declare new types, ensure they are not considered
2418 : attached to a named module. */
2419 208 : auto module_kind_override = make_temp_override
2420 208 : (module_kind, module_kind & ~(MK_PURVIEW | MK_ATTACH | MK_EXPORTING));
2421 208 : tree fnname = get_identifier ("handle_contract_violation");
2422 208 : tree viol_name = get_identifier ("contract_violation");
2423 208 : tree l = lookup_qualified_name (global_namespace, fnname,
2424 : LOOK_want::HIDDEN_FRIEND);
2425 500 : for (tree f: lkp_range (l))
2426 208 : if (TREE_CODE (f) == FUNCTION_DECL)
2427 : {
2428 124 : tree parms = TYPE_ARG_TYPES (TREE_TYPE (f));
2429 124 : if (remaining_arguments (parms) != 1)
2430 0 : continue;
2431 124 : tree parmtype = non_reference (TREE_VALUE (parms));
2432 124 : if (CLASS_TYPE_P (parmtype)
2433 248 : && TYPE_IDENTIFIER (parmtype) == viol_name)
2434 124 : return f;
2435 : }
2436 :
2437 84 : tree violation = lookup_std_contracts_type (viol_name);
2438 84 : tree fntype = NULL_TREE;
2439 84 : tree v_obj_ref = cp_build_qualified_type (violation, TYPE_QUAL_CONST);
2440 84 : v_obj_ref = cp_build_reference_type (v_obj_ref, /*rval*/false);
2441 84 : fntype = build_function_type_list (void_type_node, v_obj_ref, NULL_TREE);
2442 :
2443 84 : push_nested_namespace (global_namespace);
2444 84 : tree fndecl
2445 84 : = build_cp_library_fn_ptr ("handle_contract_violation", fntype, ECF_COLD);
2446 84 : pushdecl_namespace_level (fndecl, /*hiding*/true);
2447 84 : pop_nested_namespace (global_namespace);
2448 :
2449 : /* Build the parameter(s). */
2450 84 : tree parms = cp_build_parm_decl (fndecl, NULL_TREE, v_obj_ref);
2451 84 : TREE_USED (parms) = true;
2452 84 : DECL_READ_P (parms) = true;
2453 84 : DECL_ARGUMENTS (fndecl) = parms;
2454 84 : return fndecl;
2455 208 : }
2456 :
2457 : /* Build the call to handle_contract_violation for VIOLATION. */
2458 :
2459 : static void
2460 208 : build_contract_handler_call (tree violation)
2461 : {
2462 208 : tree violation_fn = declare_handle_contract_violation ();
2463 208 : tree call = build_call_n (violation_fn, 1, violation);
2464 208 : finish_expr_stmt (call);
2465 208 : }
2466 :
2467 : /* If we have emitted any contracts in this TU that will call a violation
2468 : handler, then emit the wrappers for the handler. */
2469 :
2470 : void
2471 130 : maybe_emit_violation_handler_wrappers ()
2472 : {
2473 : /* We might need the terminate wrapper, even if we do not use the violation
2474 : handler wrappers. */
2475 130 : if (tu_terminate_wrapper && flag_contracts_conservative_ipa)
2476 105 : build_terminate_wrapper ();
2477 :
2478 130 : if (!tu_has_violation && !tu_has_violation_exception)
2479 : return;
2480 :
2481 104 : tree terminate_wrapper = terminate_fn;
2482 104 : if (flag_contracts_conservative_ipa)
2483 104 : terminate_wrapper = tu_terminate_wrapper;
2484 :
2485 : /* tu_has_violation */
2486 104 : start_preparsed_function (tu_has_violation, NULL_TREE,
2487 : SF_DEFAULT | SF_PRE_PARSED);
2488 104 : tree body = begin_function_body ();
2489 104 : tree compound_stmt = begin_compound_stmt (BCS_FN_BODY);
2490 104 : tree v = DECL_ARGUMENTS (tu_has_violation);
2491 104 : tree semantic = DECL_CHAIN (v);
2492 :
2493 : /* We are going to call the handler. */
2494 104 : build_contract_handler_call (v);
2495 :
2496 104 : tree if_observe = begin_if_stmt ();
2497 : /* if (observe) return; */
2498 104 : tree cond = build2 (EQ_EXPR, uint16_type_node, semantic,
2499 : build_int_cst (uint16_type_node, (uint16_t)CES_OBSERVE));
2500 104 : finish_if_stmt_cond (cond, if_observe);
2501 104 : emit_builtin_observable_checkpoint ();
2502 104 : finish_then_clause (if_observe);
2503 104 : begin_else_clause (if_observe);
2504 : /* else terminate. */
2505 104 : finish_expr_stmt (build_call_a (terminate_wrapper, 0, nullptr));
2506 104 : finish_else_clause (if_observe);
2507 104 : finish_if_stmt (if_observe);
2508 104 : finish_return_stmt (NULL_TREE);
2509 :
2510 104 : finish_compound_stmt (compound_stmt);
2511 104 : finish_function_body (body);
2512 104 : tu_has_violation = finish_function (false);
2513 104 : expand_or_defer_fn (tu_has_violation);
2514 :
2515 : /* tu_has_violation_exception */
2516 104 : start_preparsed_function (tu_has_violation_exception, NULL_TREE,
2517 : SF_DEFAULT | SF_PRE_PARSED);
2518 104 : body = begin_function_body ();
2519 104 : compound_stmt = begin_compound_stmt (BCS_FN_BODY);
2520 104 : v = DECL_ARGUMENTS (tu_has_violation_exception);
2521 104 : semantic = DECL_CHAIN (v);
2522 104 : location_t loc = DECL_SOURCE_LOCATION (tu_has_violation_exception);
2523 :
2524 104 : tree a_type = strip_top_quals (non_reference (TREE_TYPE (v)));
2525 104 : tree v2 = build_decl (loc, VAR_DECL, NULL_TREE, a_type);
2526 104 : DECL_SOURCE_LOCATION (v2) = loc;
2527 104 : DECL_CONTEXT (v2) = current_function_decl;
2528 104 : DECL_ARTIFICIAL (v2) = true;
2529 104 : layout_decl (v2, 0);
2530 104 : v2 = pushdecl (v2);
2531 104 : add_decl_expr (v2);
2532 104 : tree r = cp_build_init_expr (v2, convert_from_reference (v));
2533 104 : finish_expr_stmt (r);
2534 104 : tree memb = lookup_member (a_type, get_identifier ("_M_detection_mode"),
2535 : /*protect=*/1, /*want_type=*/0, tf_warning_or_error);
2536 104 : r = build_class_member_access_expr (v2, memb, NULL_TREE, false,
2537 : tf_warning_or_error);
2538 104 : r = cp_build_modify_expr
2539 104 : (loc, r, NOP_EXPR,
2540 : build_int_cst (uint16_type_node, (uint16_t)CDM_EVAL_EXCEPTION),
2541 : tf_warning_or_error);
2542 104 : finish_expr_stmt (r);
2543 : /* We are going to call the handler. */
2544 104 : build_contract_handler_call (v);
2545 :
2546 104 : if_observe = begin_if_stmt ();
2547 : /* if (observe) return; */
2548 104 : cond = build2 (EQ_EXPR, uint16_type_node, semantic,
2549 : build_int_cst (uint16_type_node, (uint16_t)CES_OBSERVE));
2550 104 : finish_if_stmt_cond (cond, if_observe);
2551 104 : emit_builtin_observable_checkpoint ();
2552 104 : finish_then_clause (if_observe);
2553 104 : begin_else_clause (if_observe);
2554 : /* else terminate. */
2555 104 : finish_expr_stmt (build_call_a (terminate_wrapper, 0, nullptr));
2556 104 : finish_else_clause (if_observe);
2557 104 : finish_if_stmt (if_observe);
2558 104 : finish_return_stmt (NULL_TREE);
2559 104 : finish_compound_stmt (compound_stmt);
2560 104 : finish_function_body (body);
2561 104 : tu_has_violation_exception = finish_function (false);
2562 104 : expand_or_defer_fn (tu_has_violation_exception);
2563 : }
2564 :
2565 : /* Build a layout-compatible internal version of contract_violation type. */
2566 :
2567 : static tree
2568 134 : get_contract_violation_fields ()
2569 : {
2570 134 : tree fields = NULL_TREE;
2571 : /* Must match <contracts>:
2572 : class contract_violation {
2573 : uint16_t _M_version;
2574 : assertion_kind _M_assertion_kind;
2575 : evaluation_semantic _M_evaluation_semantic;
2576 : detection_mode _M_detection_mode;
2577 : const char* _M_comment;
2578 : void *_M_src_loc_ptr;
2579 : __vendor_ext* _M_ext;
2580 : };
2581 : If this changes, also update the initializer in
2582 : build_contract_violation. */
2583 134 : const tree types[] = { uint16_type_node,
2584 : uint16_type_node,
2585 : uint16_type_node,
2586 : uint16_type_node,
2587 134 : const_string_type_node,
2588 134 : ptr_type_node,
2589 : ptr_type_node
2590 134 : };
2591 134 : const char *names[] = { "_M_version",
2592 : "_M_assertion_kind",
2593 : "_M_evaluation_semantic",
2594 : "_M_detection_mode",
2595 : "_M_comment",
2596 : "_M_src_loc_ptr",
2597 : "_M_ext",
2598 : };
2599 134 : unsigned n = 0;
2600 1072 : for (tree type : types)
2601 : {
2602 : /* finish_builtin_struct wants fields chained in reverse. */
2603 938 : tree next = build_decl (BUILTINS_LOCATION, FIELD_DECL,
2604 938 : get_identifier(names[n++]), type);
2605 938 : DECL_CHAIN (next) = fields;
2606 938 : fields = next;
2607 : }
2608 134 : return fields;
2609 : }
2610 :
2611 : /* Build a type to represent contract violation objects. */
2612 :
2613 : static tree
2614 134 : init_builtin_contract_violation_type ()
2615 : {
2616 134 : if (builtin_contract_violation_type)
2617 : return builtin_contract_violation_type;
2618 :
2619 134 : tree fields = get_contract_violation_fields ();
2620 :
2621 134 : iloc_sentinel ils (input_location);
2622 134 : input_location = BUILTINS_LOCATION;
2623 134 : builtin_contract_violation_type = make_class_type (RECORD_TYPE);
2624 134 : finish_builtin_struct (builtin_contract_violation_type,
2625 : "__builtin_contract_violation_type", fields, NULL_TREE);
2626 268 : CLASSTYPE_AS_BASE (builtin_contract_violation_type)
2627 134 : = builtin_contract_violation_type;
2628 134 : DECL_CONTEXT (TYPE_NAME (builtin_contract_violation_type))
2629 134 : = FROB_CONTEXT (global_namespace);
2630 134 : CLASSTYPE_LITERAL_P (builtin_contract_violation_type) = true;
2631 134 : CLASSTYPE_LAZY_COPY_CTOR (builtin_contract_violation_type) = true;
2632 134 : xref_basetypes (builtin_contract_violation_type, /*bases=*/NULL_TREE);
2633 134 : DECL_CONTEXT (TYPE_NAME (builtin_contract_violation_type))
2634 134 : = FROB_CONTEXT (global_namespace);
2635 134 : DECL_ARTIFICIAL (TYPE_NAME (builtin_contract_violation_type)) = true;
2636 134 : TYPE_ARTIFICIAL (builtin_contract_violation_type) = true;
2637 134 : builtin_contract_violation_type
2638 134 : = cp_build_qualified_type (builtin_contract_violation_type,
2639 : TYPE_QUAL_CONST);
2640 134 : return builtin_contract_violation_type;
2641 134 : }
2642 :
2643 : /* Early initialisation of types and functions we will use. */
2644 : void
2645 134 : init_contracts ()
2646 : {
2647 134 : init_terminate_fn ();
2648 134 : init_builtin_contract_violation_type ();
2649 134 : }
2650 :
2651 : static GTY(()) tree contracts_source_location_impl_type;
2652 :
2653 : /* Build a layout-compatible internal version of source location __impl
2654 : type. */
2655 :
2656 : static tree
2657 104 : get_contracts_source_location_impl_type (tree context = NULL_TREE)
2658 : {
2659 104 : if (contracts_source_location_impl_type)
2660 : return contracts_source_location_impl_type;
2661 :
2662 : /* First see if we have a declaration that we can use. */
2663 104 : tree contracts_source_location_type
2664 104 : = lookup_std_type (get_identifier ("source_location"));
2665 :
2666 104 : if (contracts_source_location_type
2667 104 : && contracts_source_location_type != error_mark_node
2668 208 : && TYPE_FIELDS (contracts_source_location_type))
2669 : {
2670 22 : contracts_source_location_impl_type = get_source_location_impl_type ();
2671 22 : return contracts_source_location_impl_type;
2672 : }
2673 :
2674 : /* We do not, so build the __impl layout equivalent type, which must
2675 : match <source_location>:
2676 : struct __impl
2677 : {
2678 : const char* _M_file_name;
2679 : const char* _M_function_name;
2680 : unsigned _M_line;
2681 : unsigned _M_column;
2682 : }; */
2683 82 : const tree types[] = { const_string_type_node,
2684 : const_string_type_node,
2685 82 : uint_least32_type_node,
2686 82 : uint_least32_type_node };
2687 :
2688 82 : const char *names[] = { "_M_file_name",
2689 : "_M_function_name",
2690 : "_M_line",
2691 : "_M_column",
2692 : };
2693 82 : tree fields = NULL_TREE;
2694 82 : unsigned n = 0;
2695 410 : for (tree type : types)
2696 : {
2697 : /* finish_builtin_struct wants fields chained in reverse. */
2698 328 : tree next = build_decl (BUILTINS_LOCATION, FIELD_DECL,
2699 328 : get_identifier (names[n++]), type);
2700 328 : DECL_CHAIN (next) = fields;
2701 328 : fields = next;
2702 : }
2703 :
2704 82 : iloc_sentinel ils (input_location);
2705 82 : input_location = BUILTINS_LOCATION;
2706 82 : contracts_source_location_impl_type = cxx_make_type (RECORD_TYPE);
2707 82 : finish_builtin_struct (contracts_source_location_impl_type,
2708 : "__impl", fields, NULL_TREE);
2709 82 : DECL_CONTEXT (TYPE_NAME (contracts_source_location_impl_type)) = context;
2710 82 : DECL_ARTIFICIAL (TYPE_NAME (contracts_source_location_impl_type)) = true;
2711 82 : TYPE_ARTIFICIAL (contracts_source_location_impl_type) = true;
2712 82 : contracts_source_location_impl_type
2713 82 : = cp_build_qualified_type (contracts_source_location_impl_type,
2714 : TYPE_QUAL_CONST);
2715 :
2716 82 : return contracts_source_location_impl_type;
2717 82 : }
2718 :
2719 : static tree
2720 608 : get_src_loc_impl_ptr (location_t loc)
2721 : {
2722 608 : if (!contracts_source_location_impl_type)
2723 104 : get_contracts_source_location_impl_type ();
2724 :
2725 608 : tree fndecl = current_function_decl;
2726 : /* We might be an outlined function. */
2727 608 : if (DECL_IS_PRE_FN_P (fndecl) || DECL_IS_POST_FN_P (fndecl))
2728 18 : fndecl = get_orig_for_outlined (fndecl);
2729 : /* We might be a wrapper. */
2730 608 : if (DECL_IS_WRAPPER_FN_P (fndecl))
2731 34 : fndecl = get_orig_func_for_wrapper (fndecl);
2732 :
2733 608 : gcc_checking_assert (fndecl);
2734 608 : tree impl__
2735 608 : = build_source_location_impl (loc, fndecl,
2736 : contracts_source_location_impl_type);
2737 608 : tree p = build_pointer_type (contracts_source_location_impl_type);
2738 608 : return build_fold_addr_expr_with_type_loc (loc, impl__, p);
2739 : }
2740 :
2741 : /* Build a contract_violation layout compatible object. */
2742 :
2743 : /* Constructor. At present, this should always be constant. */
2744 :
2745 : static tree
2746 608 : build_contract_violation_ctor (tree contract)
2747 : {
2748 608 : bool can_be_const = true;
2749 608 : uint16_t version = 1;
2750 : /* Default CDM_PREDICATE_FALSE. */
2751 608 : uint16_t detection_mode = CDM_PREDICATE_FALSE;
2752 :
2753 608 : tree assertion_kind = CONTRACT_ASSERTION_KIND (contract);
2754 608 : if (!assertion_kind || really_constant_p (assertion_kind))
2755 : {
2756 608 : contract_assertion_kind kind = get_contract_assertion_kind (contract);
2757 608 : assertion_kind = build_int_cst (uint16_type_node, kind);
2758 : }
2759 : else
2760 : can_be_const = false;
2761 :
2762 608 : tree eval_semantic = CONTRACT_EVALUATION_SEMANTIC (contract);
2763 608 : gcc_checking_assert (eval_semantic);
2764 608 : if (!really_constant_p (eval_semantic))
2765 0 : can_be_const = false;
2766 :
2767 608 : tree comment = CONTRACT_COMMENT (contract);
2768 608 : if (comment && !really_constant_p (comment))
2769 : can_be_const = false;
2770 :
2771 608 : tree std_src_loc_impl_ptr = CONTRACT_STD_SOURCE_LOC (contract);
2772 608 : if (std_src_loc_impl_ptr)
2773 : {
2774 0 : std_src_loc_impl_ptr = convert_from_reference (std_src_loc_impl_ptr);
2775 0 : if (!really_constant_p (std_src_loc_impl_ptr))
2776 0 : can_be_const = false;
2777 : }
2778 : else
2779 608 : std_src_loc_impl_ptr = get_src_loc_impl_ptr (EXPR_LOCATION (contract));
2780 :
2781 : /* Must match the type layout in builtin_contract_violation_type. */
2782 608 : tree f0 = next_aggregate_field (TYPE_FIELDS (builtin_contract_violation_type));
2783 608 : tree f1 = next_aggregate_field (DECL_CHAIN (f0));
2784 608 : tree f2 = next_aggregate_field (DECL_CHAIN (f1));
2785 608 : tree f3 = next_aggregate_field (DECL_CHAIN (f2));
2786 608 : tree f4 = next_aggregate_field (DECL_CHAIN (f3));
2787 608 : tree f5 = next_aggregate_field (DECL_CHAIN (f4));
2788 608 : tree f6 = next_aggregate_field (DECL_CHAIN (f5));
2789 608 : tree ctor = build_constructor_va
2790 608 : (builtin_contract_violation_type, 7,
2791 608 : f0, build_int_cst (uint16_type_node, version),
2792 : f1, assertion_kind,
2793 : f2, eval_semantic,
2794 608 : f3, build_int_cst (uint16_type_node, detection_mode),
2795 : f4, comment,
2796 : f5, std_src_loc_impl_ptr,
2797 : f6, build_zero_cst (nullptr_type_node)); // __vendor_ext
2798 :
2799 608 : TREE_READONLY (ctor) = true;
2800 608 : if (can_be_const)
2801 608 : TREE_CONSTANT (ctor) = true;
2802 :
2803 608 : return ctor;
2804 : }
2805 :
2806 : /* Build a named TU-local constant of TYPE. */
2807 :
2808 : static tree
2809 608 : contracts_tu_local_named_var (location_t loc, const char *name, tree type)
2810 : {
2811 608 : tree var_ = build_decl (loc, VAR_DECL, NULL, type);
2812 608 : DECL_NAME (var_) = generate_internal_label (name);
2813 608 : TREE_PUBLIC (var_) = false;
2814 608 : DECL_EXTERNAL (var_) = false;
2815 608 : TREE_STATIC (var_) = true;
2816 : /* Compiler-generated. */
2817 608 : DECL_ARTIFICIAL (var_) = true;
2818 608 : TREE_CONSTANT (var_) = true;
2819 608 : layout_decl (var_, 0);
2820 608 : return var_;
2821 : }
2822 :
2823 : /* Create a read-only violation object. */
2824 :
2825 : static tree
2826 608 : build_contract_violation_constant (tree ctor, tree contract)
2827 : {
2828 608 : tree viol_ = contracts_tu_local_named_var
2829 608 : (EXPR_LOCATION (contract), "Lcontract_violation",
2830 : builtin_contract_violation_type);
2831 :
2832 608 : TREE_CONSTANT (viol_) = true;
2833 608 : DECL_INITIAL (viol_) = ctor;
2834 608 : varpool_node::finalize_decl (viol_);
2835 :
2836 608 : return viol_;
2837 : }
2838 :
2839 : /* Helper to replace references to dummy this parameters with references to
2840 : the first argument of the FUNCTION_DECL DATA. */
2841 :
2842 : static tree
2843 2913 : remap_dummy_this_1 (tree *tp, int *, void *data)
2844 : {
2845 2913 : if (!is_this_parameter (*tp))
2846 : return NULL_TREE;
2847 30 : tree fn = (tree)data;
2848 30 : *tp = DECL_ARGUMENTS (fn);
2849 30 : return NULL_TREE;
2850 : }
2851 :
2852 : /* Replace all references to dummy this parameters in EXPR with references to
2853 : the first argument of the FUNCTION_DECL FNDECL. */
2854 :
2855 : static void
2856 609 : remap_dummy_this (tree fndecl, tree *expr)
2857 : {
2858 0 : walk_tree (expr, remap_dummy_this_1, fndecl, NULL);
2859 0 : }
2860 :
2861 : /* Replace uses of user's placeholder var with the actual return value. */
2862 :
2863 : struct replace_tree
2864 : {
2865 : tree from, to;
2866 : };
2867 :
2868 : static tree
2869 1179 : remap_retval_1 (tree *here, int *do_subtree, void *d)
2870 : {
2871 1179 : replace_tree *data = (replace_tree *) d;
2872 :
2873 1179 : if (*here == data->from)
2874 : {
2875 58 : *here = data->to;
2876 58 : *do_subtree = 0;
2877 : }
2878 : else
2879 1121 : *do_subtree = 1;
2880 1179 : return NULL_TREE;
2881 : }
2882 :
2883 : static void
2884 232 : remap_retval (tree fndecl, tree contract)
2885 : {
2886 232 : struct replace_tree data;
2887 232 : data.from = POSTCONDITION_IDENTIFIER (contract);
2888 232 : gcc_checking_assert (DECL_RESULT (fndecl));
2889 232 : data.to = DECL_RESULT (fndecl);
2890 232 : walk_tree (&CONTRACT_CONDITION (contract), remap_retval_1, &data, NULL);
2891 232 : }
2892 :
2893 :
2894 : /* Genericize a CONTRACT tree, but do not attach it to the current context,
2895 : the caller is responsible for that.
2896 : This is called during genericization. */
2897 :
2898 : tree
2899 610 : build_contract_check (tree contract)
2900 : {
2901 610 : contract_evaluation_semantic semantic = get_evaluation_semantic (contract);
2902 610 : bool quick = false;
2903 610 : bool calls_handler = false;
2904 610 : switch (semantic)
2905 : {
2906 1 : case CES_IGNORE:
2907 1 : return void_node;
2908 : case CES_ENFORCE:
2909 : case CES_OBSERVE:
2910 : calls_handler = true;
2911 : break;
2912 1 : case CES_QUICK:
2913 1 : quick = true;
2914 1 : break;
2915 0 : default:
2916 0 : gcc_unreachable ();
2917 : }
2918 :
2919 609 : location_t loc = EXPR_LOCATION (contract);
2920 :
2921 609 : remap_dummy_this (current_function_decl, &CONTRACT_CONDITION (contract));
2922 609 : tree condition = CONTRACT_CONDITION (contract);
2923 609 : if (condition == error_mark_node)
2924 : return NULL_TREE;
2925 :
2926 609 : if (!flag_contract_checks_outlined && POSTCONDITION_P (contract))
2927 : {
2928 232 : remap_retval (current_function_decl, contract);
2929 232 : condition = CONTRACT_CONDITION (contract);
2930 232 : if (condition == error_mark_node)
2931 : return NULL_TREE;
2932 : }
2933 :
2934 609 : tree terminate_wrapper = terminate_fn;
2935 609 : if (flag_contracts_conservative_ipa)
2936 609 : terminate_wrapper = declare_terminate_wrapper ();
2937 609 : if (calls_handler)
2938 608 : declare_violation_handler_wrappers ();
2939 :
2940 609 : bool check_might_throw = (flag_exceptions
2941 609 : && !expr_noexcept_p (condition, tf_none));
2942 :
2943 : /* Build a statement expression to hold a contract check, with the check
2944 : potentially wrapped in a try-catch expr. */
2945 609 : tree cc_bind = build3 (BIND_EXPR, void_type_node, NULL, NULL, NULL);
2946 609 : BIND_EXPR_BODY (cc_bind) = push_stmt_list ();
2947 :
2948 609 : if (TREE_CODE (contract) == ASSERTION_STMT)
2949 72 : emit_builtin_observable_checkpoint ();
2950 609 : tree cond = build_x_unary_op (loc, TRUTH_NOT_EXPR, condition, NULL_TREE,
2951 : tf_warning_or_error);
2952 609 : tree violation;
2953 609 : bool viol_is_var = false;
2954 609 : if (quick)
2955 : /* We will not be calling a handler. */
2956 1 : violation = build_zero_cst (nullptr_type_node);
2957 : else
2958 : {
2959 : /* Build a violation object, with the contract settings. */
2960 608 : tree ctor = build_contract_violation_ctor (contract);
2961 608 : gcc_checking_assert (TREE_CONSTANT (ctor));
2962 608 : violation = build_contract_violation_constant (ctor, contract);
2963 608 : violation = build_address (violation);
2964 : }
2965 :
2966 609 : tree s_const = build_int_cst (uint16_type_node, semantic);
2967 : /* So now do we need a try-catch? */
2968 609 : if (check_might_throw)
2969 : {
2970 : /* This will hold the computed condition. */
2971 118 : tree check_failed = build_decl (loc, VAR_DECL, NULL, boolean_type_node);
2972 118 : DECL_ARTIFICIAL (check_failed) = true;
2973 118 : DECL_IGNORED_P (check_failed) = true;
2974 118 : DECL_CONTEXT (check_failed) = current_function_decl;
2975 118 : layout_decl (check_failed, 0);
2976 118 : add_decl_expr (check_failed);
2977 118 : DECL_CHAIN (check_failed) = BIND_EXPR_VARS (cc_bind);
2978 118 : BIND_EXPR_VARS (cc_bind) = check_failed;
2979 118 : tree check_try = begin_try_block ();
2980 118 : finish_expr_stmt (cp_build_init_expr (check_failed, cond));
2981 118 : finish_try_block (check_try);
2982 :
2983 118 : tree handler = begin_handler ();
2984 118 : finish_handler_parms (NULL_TREE, handler); /* catch (...) */
2985 118 : if (quick)
2986 0 : finish_expr_stmt (build_call_a (terminate_wrapper, 0, nullptr));
2987 : else
2988 : {
2989 118 : if (viol_is_var)
2990 : {
2991 : /* We can update the detection mode here. */
2992 : tree memb
2993 : = lookup_member (builtin_contract_violation_type,
2994 : get_identifier ("_M_detection_mode"),
2995 : 1, 0, tf_warning_or_error);
2996 : tree r = cp_build_indirect_ref (loc, violation, RO_UNARY_STAR,
2997 : tf_warning_or_error);
2998 : r = build_class_member_access_expr (r, memb, NULL_TREE, false,
2999 : tf_warning_or_error);
3000 : r = cp_build_modify_expr
3001 : (loc, r, NOP_EXPR,
3002 : build_int_cst (uint16_type_node, (uint16_t)CDM_EVAL_EXCEPTION),
3003 : tf_warning_or_error);
3004 : finish_expr_stmt (r);
3005 : finish_expr_stmt (build_call_n (tu_has_violation, 2,
3006 : violation, s_const));
3007 : }
3008 : else
3009 : /* We need to make a copy of the violation object to update. */
3010 118 : finish_expr_stmt (build_call_n (tu_has_violation_exception, 2,
3011 : violation, s_const));
3012 : /* If we reach here, we have handled the exception thrown and do not
3013 : need further action. */
3014 118 : tree e = cp_build_modify_expr (loc, check_failed, NOP_EXPR,
3015 : boolean_false_node,
3016 : tf_warning_or_error);
3017 118 : finish_expr_stmt (e);
3018 : }
3019 118 : finish_handler (handler);
3020 118 : finish_handler_sequence (check_try);
3021 118 : cond = check_failed;
3022 118 : BIND_EXPR_VARS (cc_bind) = nreverse (BIND_EXPR_VARS (cc_bind));
3023 : }
3024 :
3025 609 : tree do_check = begin_if_stmt ();
3026 609 : finish_if_stmt_cond (cond, do_check);
3027 609 : if (quick)
3028 1 : finish_expr_stmt (build_call_a (terminate_wrapper, 0, nullptr));
3029 : else
3030 608 : finish_expr_stmt (build_call_n (tu_has_violation, 2, violation, s_const));
3031 609 : finish_then_clause (do_check);
3032 609 : finish_if_stmt (do_check);
3033 :
3034 609 : BIND_EXPR_BODY (cc_bind) = pop_stmt_list (BIND_EXPR_BODY (cc_bind));
3035 609 : return cc_bind;
3036 : }
3037 :
3038 : #include "gt-cp-contracts.h"
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