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 2040 : contract_active_p (tree contract)
265 : {
266 718 : 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 899165 : has_active_contract_condition (tree fndecl, tree_code c)
274 : {
275 899165 : tree as = get_fn_contract_specifiers (fndecl);
276 899964 : for (; as != NULL_TREE; as = TREE_CHAIN (as))
277 : {
278 1517 : tree contract = TREE_VALUE (TREE_VALUE (as));
279 2235 : 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
288 600 : 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 898565 : 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 38475882 : contract_any_active_p (tree fndecl)
306 : {
307 38475882 : tree as = get_fn_contract_specifiers (fndecl);
308 76951772 : for (; as; as = TREE_CHAIN (as))
309 1322 : 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
317 887 : contract_any_deferred_p (tree contracts)
318 : {
319 1699 : for (; contracts; contracts = TREE_CHAIN (contracts))
320 1104 : 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 605135231 : handle_contracts_p (tree fndecl)
335 : {
336 605135231 : return (flag_contracts
337 60403267 : && !processing_template_decl
338 38475930 : && (CONTRACT_HELPER (fndecl) == ldf_contract_none)
339 643611113 : && 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
346 476 : retain_decl (tree decl, copy_body_data *)
347 : {
348 476 : return decl;
349 : }
350 :
351 : /* Lookup a name in std::, or inject it. */
352 :
353 : static tree
354 105 : lookup_std_type (tree name_id)
355 : {
356 105 : tree res_type = lookup_qualified_name
357 105 : (std_node, name_id, LOOK_want::TYPE | LOOK_want::HIDDEN_FRIEND);
358 :
359 105 : if (TREE_CODE (res_type) == TYPE_DECL)
360 22 : res_type = TREE_TYPE (res_type);
361 : else
362 : {
363 83 : push_nested_namespace (std_node);
364 83 : res_type = make_class_type (RECORD_TYPE);
365 83 : create_implicit_typedef (name_id, res_type);
366 83 : DECL_SOURCE_LOCATION (TYPE_NAME (res_type)) = BUILTINS_LOCATION;
367 83 : DECL_CONTEXT (TYPE_NAME (res_type)) = current_namespace;
368 83 : pushdecl_namespace_level (TYPE_NAME (res_type), /*hidden*/true);
369 83 : pop_nested_namespace (std_node);
370 : }
371 105 : 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
378 618 : get_contract_assertion_kind (tree contract)
379 : {
380 618 : if (CONTRACT_ASSERTION_KIND (contract))
381 : {
382 618 : tree s = CONTRACT_ASSERTION_KIND (contract);
383 618 : tree i = (TREE_CODE (s) == INTEGER_CST) ? s
384 0 : : DECL_INITIAL (STRIP_NOPS (s));
385 618 : gcc_checking_assert (!type_dependent_expression_p (s) && i);
386 618 : 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 3257 : get_evaluation_semantic (const_tree contract)
404 : {
405 3257 : if (CONTRACT_EVALUATION_SEMANTIC (contract))
406 : {
407 3257 : tree s = CONTRACT_EVALUATION_SEMANTIC (contract);
408 3257 : tree i = (TREE_CODE (s) == INTEGER_CST) ? s
409 0 : : DECL_INITIAL (STRIP_NOPS (s));
410 3257 : gcc_checking_assert (!type_dependent_expression_p (s) && i);
411 3257 : switch (contract_evaluation_semantic ev =
412 3257 : (contract_evaluation_semantic) tree_to_uhwi (i))
413 : {
414 : /* This needs to be kept in step with any added semantics. */
415 3257 : case CES_IGNORE:
416 3257 : case CES_OBSERVE:
417 3257 : case CES_ENFORCE:
418 3257 : case CES_QUICK:
419 3257 : 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
431 893 : get_contract_end_loc (tree contracts)
432 : {
433 893 : tree last = NULL_TREE;
434 2388 : for (tree a = contracts; a; a = TREE_CHAIN (a))
435 1495 : last = a;
436 893 : gcc_checking_assert (last);
437 893 : last = CONTRACT_STATEMENT (last);
438 893 : 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 1384 : finish_contract_condition (cp_expr condition)
453 : {
454 1384 : 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 1374 : if (!CAN_HAVE_LOCATION_P (condition)
462 72 : && condition.get_location () != UNKNOWN_LOCATION)
463 : {
464 72 : tree_code code
465 72 : = (((CONSTANT_CLASS_P (condition) && TREE_CODE (condition) != STRING_CST)
466 0 : || (TREE_CODE (condition) == CONST_DECL && !TREE_STATIC (condition)))
467 72 : ? NON_LVALUE_EXPR : VIEW_CONVERT_EXPR);
468 72 : condition = build1_loc (condition.get_location (), code,
469 72 : TREE_TYPE (condition), condition);
470 72 : EXPR_LOCATION_WRAPPER_P (condition) = true;
471 : }
472 :
473 1374 : if (type_dependent_expression_p (condition))
474 : return condition;
475 :
476 1027 : 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 2124 : view_as_const (tree decl)
484 : {
485 2124 : if (decl
486 2124 : && !CP_TYPE_CONST_P (TREE_TYPE (decl)))
487 : {
488 1530 : gcc_checking_assert (!contract_const_wrapper_p (decl));
489 1530 : tree ctype = TREE_TYPE (decl);
490 1530 : location_t loc =
491 1530 : EXPR_P (decl) ? EXPR_LOCATION (decl) : DECL_SOURCE_LOCATION (decl);
492 1530 : ctype = cp_build_qualified_type (ctype, (cp_type_quals (ctype)
493 : | TYPE_QUAL_CONST));
494 1530 : decl = build1 (VIEW_CONVERT_EXPR, ctype, decl);
495 1530 : SET_EXPR_LOCATION (decl, loc);
496 : /* Mark the VCE as contract const wrapper. */
497 1530 : CONST_WRAPPER_P (decl) = true;
498 : }
499 2124 : return decl;
500 : }
501 :
502 : /* Constify access to DECL from within the contract condition. */
503 :
504 : tree
505 1622 : constify_contract_access (tree decl)
506 : {
507 : /* We check if we have a variable, a parameter, a variable of reference type,
508 : * or a parameter of reference type
509 : */
510 1622 : if (!TREE_READONLY (decl)
511 1622 : && (VAR_P (decl)
512 1390 : || (TREE_CODE (decl) == PARM_DECL)
513 463 : || (REFERENCE_REF_P (decl)
514 91 : && (VAR_P (TREE_OPERAND (decl, 0))
515 87 : || (TREE_CODE (TREE_OPERAND (decl, 0)) == PARM_DECL)
516 5 : || (TREE_CODE (TREE_OPERAND (decl, 0))
517 : == TEMPLATE_PARM_INDEX)))))
518 1099 : decl = view_as_const (decl);
519 :
520 1622 : return decl;
521 : }
522 :
523 : /* Indicate that PARM_DECL DECL is ODR used in a postcondition. */
524 :
525 : static void
526 482 : set_parm_used_in_post (tree decl, bool constify = true)
527 : {
528 482 : gcc_checking_assert (TREE_CODE (decl) == PARM_DECL);
529 482 : DECL_LANG_FLAG_4 (decl) = constify;
530 482 : }
531 :
532 : /* Test if PARM_DECL is ODR used in a postcondition. */
533 :
534 : static bool
535 485 : parm_used_in_post_p (const_tree decl)
536 : {
537 : /* Check if this parameter is odr used within a function's postcondition */
538 485 : return ((TREE_CODE (decl) == PARM_DECL) && DECL_LANG_FLAG_4 (decl));
539 : }
540 :
541 : /* If declaration DECL is a PARM_DECL and it appears in a postcondition, then
542 : check that it is not a non-const by-value param. LOCATION is where the
543 : expression was found and is used for diagnostic purposes. */
544 :
545 : void
546 705790827 : check_param_in_postcondition (tree decl, location_t location)
547 : {
548 705790827 : if (processing_postcondition
549 1013 : && TREE_CODE (decl) == PARM_DECL
550 : /* TREE_CODE (decl) == PARM_DECL only holds for non-reference
551 : parameters. */
552 620 : && !cp_unevaluated_operand
553 : /* Return value parameter has DECL_ARTIFICIAL flag set. The flag
554 : presence of the flag should be sufficient to distinguish the
555 : return value parameter in this context. */
556 705791303 : && !(DECL_ARTIFICIAL (decl)))
557 : {
558 320 : set_parm_used_in_post (decl);
559 :
560 320 : if (!dependent_type_p (TREE_TYPE (decl))
561 320 : && !CP_TYPE_CONST_P (TREE_TYPE (decl)))
562 : {
563 76 : error_at (location,
564 : "a value parameter used in a postcondition must be const");
565 76 : inform (DECL_SOURCE_LOCATION (decl), "parameter declared here");
566 : }
567 : }
568 705790827 : }
569 :
570 : /* Check if parameters used in postconditions are const qualified on
571 : a redeclaration that does not specify contracts or on an instantiation
572 : of a function template. */
573 :
574 : void
575 137955415 : check_postconditions_in_redecl (tree olddecl, tree newdecl)
576 : {
577 137955415 : tree contract_spec = get_fn_contract_specifiers (olddecl);
578 137955415 : if (!contract_spec)
579 : return;
580 :
581 286 : tree t1 = FUNCTION_FIRST_USER_PARM (olddecl);
582 286 : tree t2 = FUNCTION_FIRST_USER_PARM (newdecl);
583 :
584 1057 : for (; t1 && t1 != void_list_node;
585 485 : t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
586 : {
587 485 : if (parm_used_in_post_p (t1))
588 : {
589 162 : set_parm_used_in_post (t2);
590 162 : if (!dependent_type_p (TREE_TYPE (t2))
591 126 : && !CP_TYPE_CONST_P (TREE_TYPE (t2))
592 224 : && !TREE_READONLY (t2))
593 : {
594 62 : error_at (DECL_SOURCE_LOCATION (t2),
595 : "value parameter %qE used in a postcondition must be const", t2);
596 62 : inform (DECL_SOURCE_LOCATION (olddecl),
597 : "previous declaration here");
598 : }
599 : }
600 : }
601 : }
602 :
603 : /* Map from FUNCTION_DECL to a FUNCTION_DECL for either the PRE_FN or POST_FN.
604 : These are used to parse contract conditions and are called inside the body
605 : of the guarded function. */
606 : static GTY(()) hash_map<tree, tree> *decl_pre_fn;
607 : static GTY(()) hash_map<tree, tree> *decl_post_fn;
608 :
609 : /* Given a pre or post function decl (for an outlined check function) return
610 : the decl for the function for which the outlined checks are being
611 : performed. */
612 : static GTY(()) hash_map<tree, tree> *orig_from_outlined;
613 :
614 : /* Makes PRE the precondition function for FNDECL. */
615 :
616 : static void
617 8 : set_precondition_function (tree fndecl, tree pre)
618 : {
619 8 : gcc_assert (pre);
620 8 : hash_map_maybe_create<hm_ggc> (decl_pre_fn);
621 8 : gcc_checking_assert (!decl_pre_fn->get (fndecl));
622 8 : decl_pre_fn->put (fndecl, pre);
623 :
624 8 : hash_map_maybe_create<hm_ggc> (orig_from_outlined);
625 8 : gcc_checking_assert (!orig_from_outlined->get (pre));
626 8 : orig_from_outlined->put (pre, fndecl);
627 8 : }
628 :
629 : /* Makes POST the postcondition function for FNDECL. */
630 :
631 : static void
632 26 : set_postcondition_function (tree fndecl, tree post)
633 : {
634 26 : gcc_checking_assert (post);
635 26 : hash_map_maybe_create<hm_ggc> (decl_post_fn);
636 26 : gcc_checking_assert (!decl_post_fn->get (fndecl));
637 26 : decl_post_fn->put (fndecl, post);
638 :
639 26 : hash_map_maybe_create<hm_ggc> (orig_from_outlined);
640 26 : gcc_checking_assert (!orig_from_outlined->get (post));
641 26 : orig_from_outlined->put (post, fndecl);
642 26 : }
643 :
644 : /* For a given pre or post condition function, find the checked function. */
645 : tree
646 18 : get_orig_for_outlined (tree fndecl)
647 : {
648 18 : gcc_checking_assert (fndecl);
649 18 : tree *result = hash_map_safe_get (orig_from_outlined, fndecl);
650 18 : return result ? *result : NULL_TREE ;
651 : }
652 :
653 : /* For a given function OLD_FN set suitable names for NEW_FN (which is an
654 : outlined contract check) usually by appending '.pre' or '.post'.
655 :
656 : For functions with special meaning names (i.e. main and cdtors) we need to
657 : make special provisions and therefore handle all the contracts function
658 : name changes here, rather than requiring a separate update to mangle.cc.
659 :
660 : PRE specifies if we need an identifier for a pre or post contract check. */
661 :
662 : static void
663 56 : contracts_fixup_names (tree new_fn, tree old_fn, bool pre, bool wrapper)
664 : {
665 56 : bool cdtor = DECL_CXX_CONSTRUCTOR_P (old_fn)
666 56 : || DECL_CXX_DESTRUCTOR_P (old_fn);
667 56 : const char *fname = IDENTIFIER_POINTER (DECL_NAME (old_fn));
668 82 : const char *append = wrapper ? "contract_wrapper"
669 34 : : (pre ? "pre" : "post");
670 56 : size_t len = strlen (fname);
671 : /* Cdtor names have a space at the end. We need to remove that space
672 : when forming the new identifier. */
673 56 : char *nn = xasprintf ("%.*s%s%s",
674 0 : cdtor ? (int)len-1 : int(len),
675 : fname,
676 : JOIN_STR,
677 : append);
678 56 : DECL_NAME (new_fn) = get_identifier (nn);
679 56 : free (nn);
680 :
681 : /* Now do the mangled version. */
682 56 : fname = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (old_fn));
683 56 : nn = xasprintf ("%s%s%s", fname, JOIN_STR, append);
684 56 : SET_DECL_ASSEMBLER_NAME (new_fn, get_identifier (nn));
685 56 : free (nn);
686 56 : }
687 :
688 : /* Build a declaration for the pre- or postcondition of a guarded FNDECL. */
689 :
690 : static tree
691 34 : build_contract_condition_function (tree fndecl, bool pre)
692 : {
693 34 : if (error_operand_p (fndecl))
694 0 : return error_mark_node;
695 :
696 : /* Start the copy. */
697 34 : tree fn = copy_decl (fndecl);
698 :
699 : /* Don't propagate declaration attributes to the checking function,
700 : including the original contracts. */
701 34 : DECL_ATTRIBUTES (fn) = NULL_TREE;
702 :
703 : /* If requested, disable optimisation of checking functions; this can, in
704 : some cases, prevent UB from eliding the checks themselves. */
705 34 : if (flag_contract_disable_optimized_checks)
706 0 : DECL_ATTRIBUTES (fn)
707 0 : = tree_cons (get_identifier ("optimize"),
708 : build_tree_list (NULL_TREE, build_string (3, "-O0")),
709 : NULL_TREE);
710 :
711 : /* Now parse and add any internal representation of these attrs to the
712 : decl. */
713 34 : if (DECL_ATTRIBUTES (fn))
714 0 : cplus_decl_attributes (&fn, DECL_ATTRIBUTES (fn), 0);
715 :
716 : /* A possible later optimization may delete unused args to prevent extra arg
717 : passing. */
718 : /* Handle the args list. */
719 34 : tree arg_types = NULL_TREE;
720 34 : tree *last = &arg_types;
721 34 : for (tree arg_type = TYPE_ARG_TYPES (TREE_TYPE (fn));
722 89 : arg_type && arg_type != void_list_node;
723 55 : arg_type = TREE_CHAIN (arg_type))
724 : {
725 55 : if (DECL_IOBJ_MEMBER_FUNCTION_P (fndecl)
726 55 : && TYPE_ARG_TYPES (TREE_TYPE (fn)) == arg_type)
727 22 : continue;
728 33 : *last = build_tree_list (TREE_PURPOSE (arg_type), TREE_VALUE (arg_type));
729 33 : last = &TREE_CHAIN (*last);
730 : }
731 :
732 : /* Copy the function parameters, if present. Disable warnings for them. */
733 34 : DECL_ARGUMENTS (fn) = NULL_TREE;
734 34 : if (DECL_ARGUMENTS (fndecl))
735 : {
736 31 : tree *last_a = &DECL_ARGUMENTS (fn);
737 86 : for (tree p = DECL_ARGUMENTS (fndecl); p; p = TREE_CHAIN (p))
738 : {
739 55 : *last_a = copy_decl (p);
740 55 : suppress_warning (*last_a);
741 55 : DECL_CONTEXT (*last_a) = fn;
742 55 : last_a = &TREE_CHAIN (*last_a);
743 : }
744 : }
745 :
746 34 : tree orig_fn_value_type = TREE_TYPE (TREE_TYPE (fn));
747 34 : if (!pre && !VOID_TYPE_P (orig_fn_value_type))
748 : {
749 : /* For post contracts that deal with a non-void function, append a
750 : parameter to pass the return value. */
751 20 : tree name = get_identifier ("__r");
752 20 : tree parm = build_lang_decl (PARM_DECL, name, orig_fn_value_type);
753 20 : DECL_CONTEXT (parm) = fn;
754 20 : DECL_ARTIFICIAL (parm) = true;
755 20 : suppress_warning (parm);
756 20 : DECL_ARGUMENTS (fn) = chainon (DECL_ARGUMENTS (fn), parm);
757 20 : *last = build_tree_list (NULL_TREE, orig_fn_value_type);
758 20 : last = &TREE_CHAIN (*last);
759 : }
760 :
761 34 : *last = void_list_node;
762 :
763 34 : tree adjusted_type = NULL_TREE;
764 :
765 : /* The handlers are void fns. */
766 34 : if (DECL_IOBJ_MEMBER_FUNCTION_P (fndecl))
767 22 : adjusted_type = build_method_type_directly (DECL_CONTEXT (fndecl),
768 : void_type_node,
769 : arg_types);
770 : else
771 12 : adjusted_type = build_function_type (void_type_node, arg_types);
772 :
773 : /* If the original function is noexcept, build a noexcept function. */
774 34 : if (flag_exceptions && type_noexcept_p (TREE_TYPE (fndecl)))
775 4 : adjusted_type = build_exception_variant (adjusted_type, noexcept_true_spec);
776 :
777 34 : TREE_TYPE (fn) = adjusted_type;
778 34 : DECL_RESULT (fn) = NULL_TREE; /* Let the start function code fill it in. */
779 :
780 : /* The contract check functions are never a cdtor, nor virtual. */
781 34 : DECL_CXX_DESTRUCTOR_P (fn) = DECL_CXX_CONSTRUCTOR_P (fn) = 0;
782 34 : DECL_VIRTUAL_P (fn) = false;
783 :
784 : /* Append .pre / .post to a usable name for the original function. */
785 34 : contracts_fixup_names (fn, fndecl, pre, /*wrapper*/false);
786 :
787 34 : DECL_INITIAL (fn) = NULL_TREE;
788 60 : CONTRACT_HELPER (fn) = pre ? ldf_contract_pre : ldf_contract_post;
789 : /* We might have a pre/post for a wrapper. */
790 34 : DECL_CONTRACT_WRAPPER (fn) = DECL_CONTRACT_WRAPPER (fndecl);
791 :
792 : /* Make these functions internal if we can, i.e. if the guarded function is
793 : not vague linkage, or if we can put them in a comdat group with the
794 : guarded function. */
795 34 : if (!DECL_WEAK (fndecl) || HAVE_COMDAT_GROUP)
796 : {
797 34 : TREE_PUBLIC (fn) = false;
798 34 : DECL_EXTERNAL (fn) = false;
799 34 : DECL_WEAK (fn) = false;
800 34 : DECL_COMDAT (fn) = false;
801 :
802 : /* We may not have set the comdat group on the guarded function yet.
803 : If we haven't, we'll add this to the same group in comdat_linkage
804 : later. Otherwise, add it to the same comdat group now. */
805 34 : if (DECL_ONE_ONLY (fndecl))
806 : {
807 0 : symtab_node *n = symtab_node::get (fndecl);
808 0 : cgraph_node::get_create (fn)->add_to_same_comdat_group (n);
809 : }
810 :
811 : }
812 :
813 34 : DECL_INTERFACE_KNOWN (fn) = true;
814 34 : DECL_ARTIFICIAL (fn) = true;
815 34 : suppress_warning (fn);
816 :
817 34 : return fn;
818 : }
819 :
820 : /* Build the precondition checking function for FNDECL. */
821 :
822 : static tree
823 15 : build_precondition_function (tree fndecl)
824 : {
825 15 : if (!has_active_preconditions (fndecl))
826 : return NULL_TREE;
827 :
828 8 : return build_contract_condition_function (fndecl, /*pre=*/true);
829 : }
830 :
831 : /* Build the postcondition checking function for FNDECL. If the return
832 : type is undeduced, don't build the function yet. We do that in
833 : apply_deduced_return_type. */
834 :
835 : static tree
836 33 : build_postcondition_function (tree fndecl)
837 : {
838 33 : if (!has_active_postconditions (fndecl))
839 : return NULL_TREE;
840 :
841 26 : tree type = TREE_TYPE (TREE_TYPE (fndecl));
842 26 : if (is_auto (type))
843 : return NULL_TREE;
844 :
845 26 : return build_contract_condition_function (fndecl, /*pre=*/false);
846 : }
847 :
848 : /* If we're outlining the contract, build the functions to do the
849 : precondition and postcondition checks, and associate them with
850 : the function decl FNDECL.
851 : */
852 :
853 : static void
854 15 : build_contract_function_decls (tree fndecl)
855 : {
856 : /* Build the pre/post functions (or not). */
857 15 : if (!get_precondition_function (fndecl))
858 15 : if (tree pre = build_precondition_function (fndecl))
859 8 : set_precondition_function (fndecl, pre);
860 :
861 15 : if (!get_postcondition_function (fndecl))
862 15 : if (tree post = build_postcondition_function (fndecl))
863 8 : set_postcondition_function (fndecl, post);
864 15 : }
865 :
866 : /* Map from FUNCTION_DECL to a FUNCTION_DECL for contract wrapper. */
867 :
868 : static GTY(()) hash_map<tree, tree> *decl_wrapper_fn = nullptr;
869 :
870 : /* Map from the function decl of a wrapper to the function that it wraps. */
871 :
872 : static GTY(()) hash_map<tree, tree> *decl_for_wrapper = nullptr;
873 :
874 : /* Makes wrapper the precondition function for FNDECL. */
875 :
876 : static void
877 22 : set_contract_wrapper_function (tree fndecl, tree wrapper)
878 : {
879 22 : gcc_checking_assert (wrapper && fndecl);
880 22 : hash_map_maybe_create<hm_ggc> (decl_wrapper_fn);
881 22 : gcc_checking_assert (decl_wrapper_fn && !decl_wrapper_fn->get (fndecl));
882 22 : decl_wrapper_fn->put (fndecl, wrapper);
883 :
884 : /* We need to know the wrapped function when composing the diagnostic. */
885 22 : hash_map_maybe_create<hm_ggc> (decl_for_wrapper);
886 22 : gcc_checking_assert (decl_for_wrapper && !decl_for_wrapper->get (wrapper));
887 22 : decl_for_wrapper->put (wrapper, fndecl);
888 22 : }
889 :
890 : /* Returns the wrapper function decl for FNDECL, or null if not set. */
891 :
892 : static tree
893 22 : get_contract_wrapper_function (tree fndecl)
894 : {
895 22 : gcc_checking_assert (fndecl);
896 22 : tree *result = hash_map_safe_get (decl_wrapper_fn, fndecl);
897 11 : return result ? *result : NULL_TREE;
898 : }
899 :
900 : /* Given a wrapper function WRAPPER, find the original function decl. */
901 :
902 : static tree
903 34 : get_orig_func_for_wrapper (tree wrapper)
904 : {
905 34 : gcc_checking_assert (wrapper);
906 34 : tree *result = hash_map_safe_get (decl_for_wrapper, wrapper);
907 34 : return result ? *result : NULL_TREE;
908 : }
909 :
910 : /* Build a declaration for the contract wrapper of a caller FNDECL.
911 : We're making a caller side contract check wrapper. For caller side contract
912 : checks, postconditions are only checked if check_post is true.
913 : Defer the attachment of the contracts to this function until the callee
914 : is non-dependent, or we get cases where the conditions can be non-dependent
915 : but still need tsubst-ing. */
916 :
917 : static tree
918 22 : build_contract_wrapper_function (tree fndecl)
919 : {
920 22 : if (error_operand_p (fndecl))
921 0 : return error_mark_node;
922 :
923 : /* We should not be trying to build wrappers for templates or functions that
924 : are still dependent. */
925 22 : gcc_checking_assert (!processing_template_decl
926 : && !TYPE_DEPENDENT_P (TREE_TYPE (fndecl)));
927 :
928 22 : location_t loc = DECL_SOURCE_LOCATION (fndecl);
929 :
930 : /* Fill in the names later. */
931 22 : tree wrapdecl
932 22 : = build_lang_decl_loc (loc, FUNCTION_DECL, NULL_TREE, TREE_TYPE (fndecl));
933 :
934 : /* Put the wrapper in the same context as the callee. */
935 22 : DECL_CONTEXT (wrapdecl) = DECL_CONTEXT (fndecl);
936 :
937 : /* This declaration is a contract wrapper function. */
938 22 : DECL_CONTRACT_WRAPPER (wrapdecl) = true;
939 :
940 22 : contracts_fixup_names (wrapdecl, fndecl, /*pre*/false, /*wrapper*/true);
941 :
942 22 : DECL_SOURCE_LOCATION (wrapdecl) = loc;
943 : /* The declaration was implicitly generated by the compiler. */
944 22 : DECL_ARTIFICIAL (wrapdecl) = true;
945 : /* Declaration, no definition yet. */
946 22 : DECL_INITIAL (wrapdecl) = NULL_TREE;
947 :
948 : /* Let the start function code fill in the result decl. */
949 22 : DECL_RESULT (wrapdecl) = NULL_TREE;
950 :
951 : /* Copy the function parameters, if present. Suppress (e.g. unused)
952 : warnings on them. */
953 22 : DECL_ARGUMENTS (wrapdecl) = NULL_TREE;
954 22 : if (tree p = DECL_ARGUMENTS (fndecl))
955 : {
956 22 : tree *last_a = &DECL_ARGUMENTS (wrapdecl);
957 70 : for (; p; p = TREE_CHAIN (p))
958 : {
959 48 : *last_a = copy_decl (p);
960 48 : suppress_warning (*last_a);
961 48 : DECL_CONTEXT (*last_a) = wrapdecl;
962 48 : last_a = &TREE_CHAIN (*last_a);
963 : }
964 : }
965 :
966 : /* Copy selected attributes from the original function. */
967 22 : TREE_USED (wrapdecl) = TREE_USED (fndecl);
968 :
969 : /* Copy any alignment added. */
970 22 : if (DECL_ALIGN (fndecl))
971 22 : SET_DECL_ALIGN (wrapdecl, DECL_ALIGN (fndecl));
972 22 : DECL_USER_ALIGN (wrapdecl) = DECL_USER_ALIGN (fndecl);
973 :
974 : /* Make this function internal. */
975 22 : TREE_PUBLIC (wrapdecl) = false;
976 22 : DECL_EXTERNAL (wrapdecl) = false;
977 22 : DECL_WEAK (wrapdecl) = false;
978 :
979 : /* We know this is an internal function. */
980 22 : DECL_INTERFACE_KNOWN (wrapdecl) = true;
981 22 : return wrapdecl;
982 : }
983 :
984 : static tree
985 22 : get_or_create_contract_wrapper_function (tree fndecl)
986 : {
987 22 : tree wrapdecl = get_contract_wrapper_function (fndecl);
988 22 : if (!wrapdecl)
989 : {
990 22 : wrapdecl = build_contract_wrapper_function (fndecl);
991 22 : set_contract_wrapper_function (fndecl, wrapdecl);
992 : }
993 22 : return wrapdecl;
994 : }
995 :
996 : void
997 157955161 : start_function_contracts (tree fndecl)
998 : {
999 157955161 : if (error_operand_p (fndecl))
1000 : return;
1001 :
1002 157955161 : if (!handle_contracts_p (fndecl))
1003 : return;
1004 :
1005 : /* If this is not a client side check and definition side checks are
1006 : disabled, do nothing. */
1007 364 : if (!flag_contracts_definition_check
1008 364 : && !DECL_CONTRACT_WRAPPER (fndecl))
1009 : return;
1010 :
1011 : /* Check that the postcondition result name, if any, does not shadow a
1012 : function parameter. */
1013 926 : for (tree ca = get_fn_contract_specifiers (fndecl); ca; ca = TREE_CHAIN (ca))
1014 563 : if (POSTCONDITION_P (CONTRACT_STATEMENT (ca)))
1015 245 : if (tree id = POSTCONDITION_IDENTIFIER (CONTRACT_STATEMENT (ca)))
1016 : {
1017 113 : if (id == error_mark_node)
1018 : {
1019 2 : CONTRACT_CONDITION (CONTRACT_STATEMENT (ca)) = error_mark_node;
1020 2 : continue;
1021 : }
1022 111 : tree r_name = tree_strip_any_location_wrapper (id);
1023 111 : if (TREE_CODE (id) == PARM_DECL)
1024 111 : r_name = DECL_NAME (id);
1025 111 : gcc_checking_assert (r_name && TREE_CODE (r_name) == IDENTIFIER_NODE);
1026 111 : tree seen = lookup_name (r_name);
1027 111 : if (seen
1028 2 : && TREE_CODE (seen) == PARM_DECL
1029 113 : && DECL_CONTEXT (seen) == fndecl)
1030 : {
1031 2 : auto_diagnostic_group d;
1032 2 : location_t id_l = location_wrapper_p (id)
1033 2 : ? EXPR_LOCATION (id)
1034 2 : : DECL_SOURCE_LOCATION (id);
1035 2 : location_t co_l = EXPR_LOCATION (CONTRACT_STATEMENT (ca));
1036 2 : if (id_l != UNKNOWN_LOCATION)
1037 2 : co_l = make_location (id_l, co_l, co_l);
1038 2 : error_at (co_l, "contract postcondition result name shadows a"
1039 : " function parameter");
1040 2 : inform (DECL_SOURCE_LOCATION (seen),
1041 : "parameter declared here");
1042 2 : POSTCONDITION_IDENTIFIER (CONTRACT_STATEMENT (ca))
1043 2 : = error_mark_node;
1044 2 : CONTRACT_CONDITION (CONTRACT_STATEMENT (ca)) = error_mark_node;
1045 2 : }
1046 : }
1047 :
1048 : /* If we are expanding contract assertions inline then no need to declare
1049 : the outline function decls. */
1050 363 : if (!flag_contract_checks_outlined)
1051 : return;
1052 :
1053 : /* Contracts may have just been added without a chance to parse them, though
1054 : we still need the PRE_FN available to generate a call to it. */
1055 : /* Do we already have declarations generated ? */
1056 15 : if (!DECL_PRE_FN (fndecl) && !DECL_POST_FN (fndecl))
1057 15 : build_contract_function_decls (fndecl);
1058 : }
1059 :
1060 : void
1061 897947 : maybe_update_postconditions (tree fndecl)
1062 : {
1063 : /* Update any postconditions and the postcondition checking function
1064 : as needed. If there are postconditions, we'll use those to rewrite
1065 : return statements to check postconditions. */
1066 897947 : if (has_active_postconditions (fndecl))
1067 : {
1068 18 : rebuild_postconditions (fndecl);
1069 18 : tree post = build_postcondition_function (fndecl);
1070 18 : set_postcondition_function (fndecl, post);
1071 : }
1072 897947 : }
1073 :
1074 : /* Build and return an argument list containing all the parameters of the
1075 : (presumably guarded) function decl FNDECL. This can be used to forward
1076 : all of FNDECL arguments to a function taking the same list of arguments
1077 : -- namely the unchecked form of FNDECL.
1078 :
1079 : We use CALL_FROM_THUNK_P instead of forward_parm for forwarding
1080 : semantics. */
1081 :
1082 : static vec<tree, va_gc> *
1083 38 : build_arg_list (tree fndecl)
1084 : {
1085 38 : vec<tree, va_gc> *args = make_tree_vector ();
1086 109 : for (tree t = DECL_ARGUMENTS (fndecl); t; t = DECL_CHAIN (t))
1087 71 : vec_safe_push (args, t);
1088 38 : return args;
1089 : }
1090 :
1091 : /* Build and return a thunk like call to FUNC from CALLER using the supplied
1092 : arguments. The call is like a thunk call in the fact that we do not
1093 : want to create additional copies of the arguments. We can not simply reuse
1094 : the thunk machinery as it does more than we want. More specifically, we
1095 : don't want to mark the calling function as `DECL_THUNK_P` for this
1096 : particular purpose, we only want the special treatment for the parameters
1097 : of the call we are about to generate. We temporarily mark the calling
1098 : function as DECL_THUNK_P so build_call_a does the right thing. */
1099 :
1100 : static tree
1101 38 : build_thunk_like_call (tree func, int n, tree *argarray)
1102 : {
1103 38 : bool old_decl_thunk_p = DECL_THUNK_P (current_function_decl);
1104 38 : LANG_DECL_FN_CHECK (current_function_decl)->thunk_p = true;
1105 :
1106 38 : tree call = build_call_a (func, n, argarray);
1107 :
1108 : /* Revert the `DECL_THUNK_P` flag. */
1109 38 : LANG_DECL_FN_CHECK (current_function_decl)->thunk_p = old_decl_thunk_p;
1110 :
1111 : /* Mark the call as a thunk call to allow for correct gimplification
1112 : of the arguments. */
1113 38 : CALL_FROM_THUNK_P (call) = true;
1114 :
1115 38 : return call;
1116 : }
1117 :
1118 : /* If we have a precondition function and it's valid, call it. */
1119 :
1120 : static void
1121 8 : add_pre_condition_fn_call (tree fndecl)
1122 : {
1123 : /* If we're starting a guarded function with valid contracts, we need to
1124 : insert a call to the pre function. */
1125 8 : gcc_checking_assert (DECL_PRE_FN (fndecl)
1126 : && DECL_PRE_FN (fndecl) != error_mark_node);
1127 :
1128 8 : releasing_vec args = build_arg_list (fndecl);
1129 8 : tree call = build_thunk_like_call (DECL_PRE_FN (fndecl),
1130 8 : args->length (), args->address ());
1131 :
1132 8 : finish_expr_stmt (call);
1133 8 : }
1134 :
1135 : /* Returns the parameter corresponding to the return value of a guarded
1136 : function FNDECL. Returns NULL_TREE if FNDECL has no postconditions or
1137 : is void. */
1138 :
1139 : static tree
1140 8 : get_postcondition_result_parameter (tree fndecl)
1141 : {
1142 8 : if (!fndecl || fndecl == error_mark_node)
1143 : return NULL_TREE;
1144 :
1145 8 : if (VOID_TYPE_P (TREE_TYPE (TREE_TYPE (fndecl))))
1146 : return NULL_TREE;
1147 :
1148 2 : tree post = DECL_POST_FN (fndecl);
1149 2 : if (!post || post == error_mark_node)
1150 : return NULL_TREE;
1151 :
1152 : /* The last param is the return value. */
1153 2 : return tree_last (DECL_ARGUMENTS (post));
1154 : }
1155 :
1156 : /* Build and add a call to the post-condition checking function, when that
1157 : is in use. */
1158 :
1159 : static void
1160 8 : add_post_condition_fn_call (tree fndecl)
1161 : {
1162 8 : gcc_checking_assert (DECL_POST_FN (fndecl)
1163 : && DECL_POST_FN (fndecl) != error_mark_node);
1164 :
1165 8 : releasing_vec args = build_arg_list (fndecl);
1166 8 : if (get_postcondition_result_parameter (fndecl))
1167 2 : vec_safe_push (args, DECL_RESULT (fndecl));
1168 8 : tree call = build_thunk_like_call (DECL_POST_FN (fndecl),
1169 8 : args->length (), args->address ());
1170 8 : finish_expr_stmt (call);
1171 8 : }
1172 :
1173 : /* Copy (possibly a sub-set of) contracts from CONTRACTS on FNDECL. */
1174 :
1175 : static tree
1176 400 : copy_contracts_list (tree contracts, tree fndecl,
1177 : contract_match_kind remap_kind = cmk_all)
1178 : {
1179 400 : tree last = NULL_TREE, new_contracts = NULL_TREE;
1180 1085 : for (; contracts; contracts = TREE_CHAIN (contracts))
1181 : {
1182 825 : if ((remap_kind == cmk_pre
1183 375 : && (TREE_CODE (CONTRACT_STATEMENT (contracts))
1184 : == POSTCONDITION_STMT))
1185 994 : || (remap_kind == cmk_post
1186 310 : && (TREE_CODE (CONTRACT_STATEMENT (contracts))
1187 : == PRECONDITION_STMT)))
1188 140 : continue;
1189 :
1190 545 : tree c = copy_node (contracts);
1191 1090 : TREE_VALUE (c) = build_tree_list (TREE_PURPOSE (TREE_VALUE (c)),
1192 545 : copy_node (CONTRACT_STATEMENT (c)));
1193 :
1194 545 : copy_body_data id;
1195 545 : hash_map<tree, tree> decl_map;
1196 :
1197 545 : memset (&id, 0, sizeof (id));
1198 :
1199 545 : id.src_fn = fndecl;
1200 545 : id.dst_fn = fndecl;
1201 545 : id.src_cfun = DECL_STRUCT_FUNCTION (fndecl);
1202 545 : id.decl_map = &decl_map;
1203 :
1204 545 : id.copy_decl = retain_decl;
1205 :
1206 545 : id.transform_call_graph_edges = CB_CGE_DUPLICATE;
1207 545 : id.transform_new_cfg = false;
1208 545 : id.transform_return_to_modify = false;
1209 545 : id.transform_parameter = true;
1210 :
1211 : /* Make sure not to unshare trees behind the front-end's back
1212 : since front-end specific mechanisms may rely on sharing. */
1213 545 : id.regimplify = false;
1214 545 : id.do_not_unshare = true;
1215 545 : id.do_not_fold = true;
1216 :
1217 : /* We're not inside any EH region. */
1218 545 : id.eh_lp_nr = 0;
1219 545 : walk_tree (&CONTRACT_CONDITION (CONTRACT_STATEMENT (c)),
1220 : copy_tree_body_r, &id, NULL);
1221 :
1222 :
1223 1090 : CONTRACT_COMMENT (CONTRACT_STATEMENT (c))
1224 545 : = copy_node (CONTRACT_COMMENT (CONTRACT_STATEMENT (c)));
1225 :
1226 545 : chainon (last, c);
1227 545 : last = c;
1228 545 : if (!new_contracts)
1229 400 : new_contracts = c;
1230 545 : }
1231 400 : return new_contracts;
1232 : }
1233 :
1234 : /* Returns a copy of FNDECL contracts. This is used when emiting a contract.
1235 : If we were to emit the original contract tree, any folding of the contract
1236 : condition would affect the original contract too. The original contract
1237 : tree needs to be preserved in case it is used to apply to a different
1238 : function (for inheritance or wrapping reasons). */
1239 :
1240 : static tree
1241 400 : copy_contracts (tree fndecl, contract_match_kind remap_kind = cmk_all)
1242 : {
1243 400 : tree contracts = get_fn_contract_specifiers (fndecl);
1244 400 : return copy_contracts_list (contracts, fndecl, remap_kind);
1245 : }
1246 :
1247 : /* Add the contract statement CONTRACT to the current block if valid. */
1248 :
1249 : static bool
1250 563 : emit_contract_statement (tree contract)
1251 : {
1252 : /* Only add valid contracts. */
1253 563 : if (contract == error_mark_node
1254 563 : || CONTRACT_CONDITION (contract) == error_mark_node)
1255 : return false;
1256 :
1257 555 : if (get_evaluation_semantic (contract) == CES_INVALID)
1258 : return false;
1259 :
1260 555 : add_stmt (contract);
1261 555 : return true;
1262 : }
1263 :
1264 : /* Generate the statement for the given contract by adding the contract
1265 : statement to the current block. Returns the next contract in the chain. */
1266 :
1267 : static tree
1268 545 : emit_contract (tree contract)
1269 : {
1270 545 : gcc_assert (TREE_CODE (contract) == TREE_LIST);
1271 :
1272 545 : emit_contract_statement (CONTRACT_STATEMENT (contract));
1273 :
1274 545 : return TREE_CHAIN (contract);
1275 : }
1276 :
1277 : /* Add a call or a direct evaluation of the pre checks. */
1278 :
1279 : static void
1280 250 : apply_preconditions (tree fndecl)
1281 : {
1282 250 : if (flag_contract_checks_outlined)
1283 8 : add_pre_condition_fn_call (fndecl);
1284 : else
1285 : {
1286 242 : tree contract_copy = copy_contracts (fndecl, cmk_pre);
1287 793 : for (; contract_copy; contract_copy = TREE_CHAIN (contract_copy))
1288 309 : emit_contract (contract_copy);
1289 : }
1290 250 : }
1291 :
1292 : /* Add a call or a direct evaluation of the post checks. */
1293 :
1294 : static void
1295 166 : apply_postconditions (tree fndecl)
1296 : {
1297 166 : if (flag_contract_checks_outlined)
1298 8 : add_post_condition_fn_call (fndecl);
1299 : else
1300 : {
1301 158 : tree contract_copy = copy_contracts (fndecl, cmk_post);
1302 552 : for (; contract_copy; contract_copy = TREE_CHAIN (contract_copy))
1303 236 : emit_contract (contract_copy);
1304 : }
1305 166 : }
1306 :
1307 : /* Add contract handling to the function in FNDECL.
1308 :
1309 : When we have only pre-conditions, this simply prepends a call (or a direct
1310 : evaluation, for cdtors) to the existing function body.
1311 :
1312 : When we have post conditions we build a try-finally block.
1313 : If the function might throw then the handler in the try-finally is an
1314 : EH_ELSE expression, where the post condition check is applied to the
1315 : non-exceptional path, and an empty statement is added to the EH path. If
1316 : the function has a non-throwing eh spec, then the handler is simply the
1317 : post-condition checker. */
1318 :
1319 : void
1320 142287294 : maybe_apply_function_contracts (tree fndecl)
1321 : {
1322 142287294 : if (!handle_contracts_p (fndecl))
1323 : /* We did nothing and the original function body statement list will be
1324 : popped by our caller. */
1325 : return;
1326 :
1327 : /* If this is not a client side check and definition side checks are
1328 : disabled, do nothing. */
1329 364 : if (!flag_contracts_definition_check
1330 364 : && !DECL_CONTRACT_WRAPPER (fndecl))
1331 : return;
1332 :
1333 363 : bool do_pre = has_active_preconditions (fndecl);
1334 363 : bool do_post = has_active_postconditions (fndecl);
1335 : /* We should not have reached here with nothing to do... */
1336 363 : gcc_checking_assert (do_pre || do_post);
1337 :
1338 : /* If the function is noexcept, the user's written body will be wrapped in a
1339 : MUST_NOT_THROW expression. In that case we leave the MUST_NOT_THROW in
1340 : place and do our replacement inside it. */
1341 363 : tree fnbody;
1342 363 : if (TYPE_NOEXCEPT_P (TREE_TYPE (fndecl)))
1343 : {
1344 23 : tree m_n_t_expr = expr_first (DECL_SAVED_TREE (fndecl));
1345 23 : gcc_checking_assert (TREE_CODE (m_n_t_expr) == MUST_NOT_THROW_EXPR);
1346 23 : fnbody = TREE_OPERAND (m_n_t_expr, 0);
1347 23 : TREE_OPERAND (m_n_t_expr, 0) = push_stmt_list ();
1348 : }
1349 : else
1350 : {
1351 340 : fnbody = DECL_SAVED_TREE (fndecl);
1352 340 : DECL_SAVED_TREE (fndecl) = push_stmt_list ();
1353 : }
1354 :
1355 : /* If we have a lambda with captures, ensure that those captures are in-
1356 : scope for pre and post conditions. */
1357 375 : if (LAMBDA_FUNCTION_P (fndecl)
1358 375 : && TREE_CODE (fnbody) == BIND_EXPR)
1359 : {
1360 0 : tree extract = BIND_EXPR_BODY (fnbody);
1361 0 : BIND_EXPR_BODY (fnbody) = NULL_TREE;
1362 0 : add_stmt (fnbody);
1363 0 : BIND_EXPR_BODY (fnbody) = push_stmt_list ();
1364 0 : fnbody = extract;
1365 : }
1366 :
1367 : /* Now add the pre and post conditions to the existing function body.
1368 : This copies the approach used for function try blocks. */
1369 363 : tree compound_stmt = begin_compound_stmt (0);
1370 363 : current_binding_level->artificial = true;
1371 :
1372 : /* Do not add locations for the synthesised code. */
1373 363 : location_t loc = UNKNOWN_LOCATION;
1374 :
1375 : /* For other cases, we call a function to process the check. */
1376 :
1377 : /* If we have a pre, but not a post, then just emit that and we are done. */
1378 363 : if (!do_post)
1379 : {
1380 197 : apply_preconditions (fndecl);
1381 197 : add_stmt (fnbody);
1382 197 : finish_compound_stmt (compound_stmt);
1383 197 : return;
1384 : }
1385 :
1386 166 : if (do_pre)
1387 : /* Add a precondition call, if we have one. */
1388 53 : apply_preconditions (fndecl);
1389 166 : tree try_fin = build_stmt (loc, TRY_FINALLY_EXPR, fnbody, NULL_TREE);
1390 166 : add_stmt (try_fin);
1391 166 : TREE_OPERAND (try_fin, 1) = push_stmt_list ();
1392 : /* If we have exceptions, and a function that might throw, then add
1393 : an EH_ELSE clause that allows the exception to propagate upwards
1394 : without encountering the post-condition checks. */
1395 166 : if (flag_exceptions && !type_noexcept_p (TREE_TYPE (fndecl)))
1396 : {
1397 159 : tree eh_else = build_stmt (loc, EH_ELSE_EXPR, NULL_TREE, NULL_TREE);
1398 159 : add_stmt (eh_else);
1399 159 : TREE_OPERAND (eh_else, 0) = push_stmt_list ();
1400 159 : apply_postconditions (fndecl);
1401 159 : TREE_OPERAND (eh_else, 0) = pop_stmt_list (TREE_OPERAND (eh_else, 0));
1402 159 : TREE_OPERAND (eh_else, 1) = void_node;
1403 : }
1404 : else
1405 7 : apply_postconditions (fndecl);
1406 166 : TREE_OPERAND (try_fin, 1) = pop_stmt_list (TREE_OPERAND (try_fin, 1));
1407 166 : finish_compound_stmt (compound_stmt);
1408 : /* The DECL_SAVED_TREE stmt list will be popped by our caller. */
1409 : }
1410 :
1411 : /* Rewrite the condition of contract in place, so that references to SRC's
1412 : parameters are updated to refer to DST's parameters. The postcondition
1413 : result variable is left unchanged.
1414 :
1415 : When declarations are merged, we sometimes need to update contracts to
1416 : refer to new parameters.
1417 :
1418 : If DUPLICATE_P is true, this is called by duplicate_decls to rewrite
1419 : contracts in terms of a new set of parameters. This also preserves the
1420 : references to postcondition results, which are not replaced during
1421 : merging. */
1422 :
1423 : static void
1424 238 : remap_contract (tree src, tree dst, tree contract, bool duplicate_p)
1425 : {
1426 238 : copy_body_data id;
1427 238 : hash_map<tree, tree> decl_map;
1428 :
1429 238 : memset (&id, 0, sizeof (id));
1430 238 : id.src_fn = src;
1431 238 : id.dst_fn = dst;
1432 238 : id.src_cfun = DECL_STRUCT_FUNCTION (src);
1433 238 : id.decl_map = &decl_map;
1434 :
1435 : /* If we're merging contracts, don't copy local variables. */
1436 238 : id.copy_decl = duplicate_p ? retain_decl : copy_decl_no_change;
1437 :
1438 238 : id.transform_call_graph_edges = CB_CGE_DUPLICATE;
1439 238 : id.transform_new_cfg = false;
1440 238 : id.transform_return_to_modify = false;
1441 238 : id.transform_parameter = true;
1442 :
1443 : /* Make sure not to unshare trees behind the front-end's back
1444 : since front-end specific mechanisms may rely on sharing. */
1445 238 : id.regimplify = false;
1446 238 : id.do_not_unshare = true;
1447 238 : id.do_not_fold = true;
1448 :
1449 : /* We're not inside any EH region. */
1450 238 : id.eh_lp_nr = 0;
1451 :
1452 238 : bool do_remap = false;
1453 :
1454 : /* Insert parameter remappings. */
1455 238 : gcc_checking_assert (TREE_CODE (src) == FUNCTION_DECL);
1456 238 : gcc_checking_assert (TREE_CODE (dst) == FUNCTION_DECL);
1457 :
1458 238 : int src_num_artificial_args = num_artificial_parms_for (src);
1459 238 : int dst_num_artificial_args = num_artificial_parms_for (dst);
1460 :
1461 238 : for (tree sp = DECL_ARGUMENTS (src), dp = DECL_ARGUMENTS (dst);
1462 704 : sp || dp;
1463 466 : sp = DECL_CHAIN (sp), dp = DECL_CHAIN (dp))
1464 : {
1465 469 : if (!sp && dp
1466 3 : && TREE_CODE (contract) == POSTCONDITION_STMT
1467 472 : && DECL_CHAIN (dp) == NULL_TREE)
1468 : {
1469 3 : gcc_assert (!duplicate_p);
1470 3 : if (tree result = POSTCONDITION_IDENTIFIER (contract))
1471 : {
1472 3 : gcc_assert (DECL_P (result));
1473 3 : insert_decl_map (&id, result, dp);
1474 3 : do_remap = true;
1475 : }
1476 : break;
1477 : }
1478 466 : gcc_assert (sp && dp);
1479 :
1480 466 : if (sp == dp)
1481 201 : continue;
1482 :
1483 265 : insert_decl_map (&id, sp, dp);
1484 265 : do_remap = true;
1485 :
1486 : /* First artificial arg is *this. We want to remap that. However, we
1487 : want to skip _in_charge param and __vtt_parm. Do so now. */
1488 265 : if (src_num_artificial_args > 0)
1489 : {
1490 80 : while (--src_num_artificial_args,src_num_artificial_args > 0)
1491 0 : sp = DECL_CHAIN (sp);
1492 : }
1493 265 : if (dst_num_artificial_args > 0)
1494 : {
1495 80 : while (--dst_num_artificial_args,dst_num_artificial_args > 0)
1496 0 : dp = DECL_CHAIN (dp);
1497 : }
1498 : }
1499 :
1500 238 : if (!do_remap)
1501 106 : return;
1502 :
1503 132 : walk_tree (&CONTRACT_CONDITION (contract), copy_tree_body_r, &id, NULL);
1504 238 : }
1505 :
1506 : /* Returns a copy of SOURCE contracts where any references to SOURCE's
1507 : PARM_DECLs have been rewritten to the corresponding PARM_DECL in DEST. */
1508 :
1509 : tree
1510 162 : copy_and_remap_contracts (tree dest, tree source,
1511 : contract_match_kind remap_kind)
1512 : {
1513 162 : tree last = NULL_TREE, contracts_copy= NULL_TREE;
1514 162 : tree contracts = get_fn_contract_specifiers (source);
1515 384 : for (; contracts; contracts = TREE_CHAIN (contracts))
1516 : {
1517 224 : if ((remap_kind == cmk_pre
1518 5 : && (TREE_CODE (CONTRACT_STATEMENT (contracts))
1519 : == POSTCONDITION_STMT))
1520 225 : || (remap_kind == cmk_post
1521 0 : && (TREE_CODE (CONTRACT_STATEMENT (contracts))
1522 : == PRECONDITION_STMT)))
1523 2 : continue;
1524 :
1525 : /* The first part is copying of the legacy attribute layout - eventually
1526 : this will go away. */
1527 220 : tree c = copy_node (contracts);
1528 440 : TREE_VALUE (c) = build_tree_list (TREE_PURPOSE (TREE_VALUE (c)),
1529 220 : copy_node (CONTRACT_STATEMENT (c)));
1530 : /* This is the copied contract statement. */
1531 220 : tree stmt = CONTRACT_STATEMENT (c);
1532 :
1533 : /* If we have an erroneous postcondition identifier, we also mark the
1534 : condition as invalid so only need to check that. */
1535 220 : if (CONTRACT_CONDITION (stmt) != error_mark_node)
1536 220 : remap_contract (source, dest, stmt, /*duplicate_p=*/true);
1537 :
1538 220 : if (TREE_CODE (stmt) == POSTCONDITION_STMT)
1539 : {
1540 : /* If we have a postcondition return value placeholder, then
1541 : ensure the copied one has the correct context. */
1542 77 : tree var = POSTCONDITION_IDENTIFIER (stmt);
1543 77 : if (var && var != error_mark_node)
1544 20 : DECL_CONTEXT (var) = dest;
1545 : }
1546 :
1547 220 : if (CONTRACT_COMMENT (stmt) != error_mark_node)
1548 220 : CONTRACT_COMMENT (stmt) = copy_node (CONTRACT_COMMENT (stmt));
1549 :
1550 220 : chainon (last, c);
1551 220 : last = c;
1552 220 : if (!contracts_copy)
1553 162 : contracts_copy = c;
1554 : }
1555 :
1556 162 : return contracts_copy;
1557 : }
1558 :
1559 : /* Set the (maybe) parsed contract specifier LIST for DECL. */
1560 :
1561 : void
1562 1086 : set_fn_contract_specifiers (tree decl, tree list)
1563 : {
1564 1086 : if (!decl || error_operand_p (decl))
1565 0 : return;
1566 :
1567 1086 : bool existed = false;
1568 1086 : contract_decl& rd
1569 1086 : = hash_map_safe_get_or_insert<hm_ggc> (contract_decl_map, decl, &existed);
1570 1086 : if (!existed)
1571 : {
1572 : /* This is the first time we encountered this decl, save the location
1573 : for error messages. This will ensure all error messages refer to the
1574 : contracts used for the function. */
1575 845 : location_t decl_loc = DECL_SOURCE_LOCATION (decl);
1576 845 : location_t cont_end = decl_loc;
1577 845 : if (list)
1578 845 : cont_end = get_contract_end_loc (list);
1579 845 : rd.note_loc = make_location (decl_loc, decl_loc, cont_end);
1580 : }
1581 1086 : rd.contract_specifiers = list;
1582 : }
1583 :
1584 : /* Update the entry for DECL in the map of contract specifiers with the
1585 : contracts in LIST. */
1586 :
1587 : void
1588 280 : update_fn_contract_specifiers (tree decl, tree list)
1589 : {
1590 280 : if (!decl || error_operand_p (decl))
1591 0 : return;
1592 :
1593 280 : bool existed = false;
1594 280 : contract_decl& rd
1595 280 : = hash_map_safe_get_or_insert<hm_ggc> (contract_decl_map, decl, &existed);
1596 280 : gcc_checking_assert (existed);
1597 :
1598 : /* We should only get here when we parse deferred contracts. */
1599 280 : gcc_checking_assert (!contract_any_deferred_p (list));
1600 :
1601 280 : rd.contract_specifiers = list;
1602 : }
1603 :
1604 : /* When a decl is about to be removed, then we need to release its content and
1605 : then take it out of the map. */
1606 :
1607 : void
1608 959176 : remove_decl_with_fn_contracts_specifiers (tree decl)
1609 : {
1610 959311 : if (contract_decl *p = hash_map_safe_get (contract_decl_map, decl))
1611 : {
1612 109 : p->contract_specifiers = NULL_TREE;
1613 109 : contract_decl_map->remove (decl);
1614 : }
1615 959176 : }
1616 :
1617 : /* If this function has contract specifiers, then remove them, but leave the
1618 : function registered. */
1619 :
1620 : void
1621 284990 : remove_fn_contract_specifiers (tree decl)
1622 : {
1623 285020 : if (contract_decl *p = hash_map_safe_get (contract_decl_map, decl))
1624 : {
1625 30 : p->contract_specifiers = NULL_TREE;
1626 : }
1627 284990 : }
1628 :
1629 : /* Get the contract specifier list for this DECL if there is one. */
1630 :
1631 : tree
1632 477173162 : get_fn_contract_specifiers (tree decl)
1633 : {
1634 477417395 : if (contract_decl *p = hash_map_safe_get (contract_decl_map, decl))
1635 6056 : return p->contract_specifiers;
1636 : return NULL_TREE;
1637 : }
1638 :
1639 : /* A subroutine of duplicate_decls. Diagnose issues in the redeclaration of
1640 : guarded functions. */
1641 :
1642 : void
1643 18708320 : check_redecl_contract (tree newdecl, tree olddecl)
1644 : {
1645 18708320 : if (!flag_contracts)
1646 : return;
1647 :
1648 1188967 : if (TREE_CODE (newdecl) == TEMPLATE_DECL)
1649 279705 : newdecl = DECL_TEMPLATE_RESULT (newdecl);
1650 1188967 : if (TREE_CODE (olddecl) == TEMPLATE_DECL)
1651 279705 : olddecl = DECL_TEMPLATE_RESULT (olddecl);
1652 :
1653 1188967 : tree new_contracts = get_fn_contract_specifiers (newdecl);
1654 1188967 : tree old_contracts = get_fn_contract_specifiers (olddecl);
1655 :
1656 1188967 : if (!old_contracts && !new_contracts)
1657 : return;
1658 :
1659 : /* We should always be comparing with the 'first' declaration which should
1660 : have been recorded already (if it has contract specifiers). However
1661 : if the new decl is trying to add contracts, that is an error and we do
1662 : not want to create a map entry yet. */
1663 131 : contract_decl *rdp = hash_map_safe_get (contract_decl_map, olddecl);
1664 131 : gcc_checking_assert(rdp || !old_contracts);
1665 :
1666 131 : location_t new_loc = DECL_SOURCE_LOCATION (newdecl);
1667 131 : if (new_contracts && !old_contracts)
1668 : {
1669 10 : auto_diagnostic_group d;
1670 : /* If a re-declaration has contracts, they must be the same as those
1671 : that appear on the first declaration seen (they cannot be added). */
1672 10 : location_t cont_end = get_contract_end_loc (new_contracts);
1673 10 : cont_end = make_location (new_loc, new_loc, cont_end);
1674 10 : error_at (cont_end, "declaration adds contracts to %q#D", olddecl);
1675 10 : inform (DECL_SOURCE_LOCATION (olddecl), "first declared here");
1676 10 : return;
1677 10 : }
1678 :
1679 121 : if (old_contracts && !new_contracts)
1680 : /* We allow re-declarations to omit contracts declared on the initial decl.
1681 : In fact, this is required if the conditions contain lambdas. Check if
1682 : all the parameters are correctly const qualified. */
1683 79 : check_postconditions_in_redecl (olddecl, newdecl);
1684 42 : else if (old_contracts && new_contracts
1685 42 : && !contract_any_deferred_p (old_contracts)
1686 38 : && contract_any_deferred_p (new_contracts)
1687 42 : && DECL_UNIQUE_FRIEND_P (newdecl))
1688 : {
1689 : /* Put the defered contracts on the olddecl so we parse it when
1690 : we can. */
1691 0 : set_fn_contract_specifiers (olddecl, old_contracts);
1692 : }
1693 42 : else if (contract_any_deferred_p (old_contracts)
1694 42 : || contract_any_deferred_p (new_contracts))
1695 : {
1696 : /* TODO: ignore these and figure out how to process them later. */
1697 : /* Note that a friend declaration has deferred contracts, but the
1698 : declaration of the same function outside the class definition
1699 : doesn't. */
1700 : }
1701 : else
1702 : {
1703 38 : gcc_checking_assert (old_contracts);
1704 38 : location_t cont_end = get_contract_end_loc (new_contracts);
1705 38 : cont_end = make_location (new_loc, new_loc, cont_end);
1706 : /* We have two sets - they should match or we issue a diagnostic. */
1707 38 : match_contract_specifiers (rdp->note_loc, old_contracts,
1708 : cont_end, new_contracts);
1709 : }
1710 :
1711 : return;
1712 : }
1713 :
1714 : /* Update the contracts of DEST to match the argument names from contracts
1715 : of SRC. When we merge two declarations in duplicate_decls, we preserve the
1716 : arguments from the new declaration, if the new declaration is a
1717 : definition. We need to update the contracts accordingly. */
1718 :
1719 : void
1720 11688588 : update_contract_arguments (tree srcdecl, tree destdecl)
1721 : {
1722 11688588 : tree src_contracts = get_fn_contract_specifiers (srcdecl);
1723 11688588 : tree dest_contracts = get_fn_contract_specifiers (destdecl);
1724 :
1725 11688588 : if (!src_contracts && !dest_contracts)
1726 : return;
1727 :
1728 : /* Check if src even has contracts. It is possible that a redeclaration
1729 : does not have contracts. Is this is the case, first apply contracts
1730 : to src. */
1731 85 : if (!src_contracts)
1732 : {
1733 59 : if (contract_any_deferred_p (dest_contracts))
1734 : {
1735 0 : set_fn_contract_specifiers (srcdecl, dest_contracts);
1736 : /* Nothing more to do here. */
1737 0 : return;
1738 : }
1739 : else
1740 59 : set_fn_contract_specifiers
1741 59 : (srcdecl, copy_and_remap_contracts (srcdecl, destdecl));
1742 : }
1743 :
1744 : /* For deferred contracts, we currently copy the tokens from the redeclaration
1745 : onto the decl that will be preserved. This is not ideal because the
1746 : redeclaration may have erroneous contracts.
1747 : For non deferred contracts we currently do copy and remap, which is doing
1748 : more than we need. */
1749 85 : if (contract_any_deferred_p (src_contracts))
1750 4 : set_fn_contract_specifiers (destdecl, src_contracts);
1751 : else
1752 : {
1753 : /* Temporarily rename the arguments to get the right mapping. */
1754 81 : tree tmp_arguments = DECL_ARGUMENTS (destdecl);
1755 81 : DECL_ARGUMENTS (destdecl) = DECL_ARGUMENTS (srcdecl);
1756 81 : set_fn_contract_specifiers (destdecl,
1757 : copy_and_remap_contracts (destdecl, srcdecl));
1758 81 : DECL_ARGUMENTS (destdecl) = tmp_arguments;
1759 : }
1760 : }
1761 :
1762 : /* Checks if a contract check wrapper is needed for fndecl. */
1763 :
1764 : static bool
1765 222 : should_contract_wrap_call (bool do_pre, bool do_post)
1766 : {
1767 : /* Only if the target function actually has any contracts. */
1768 0 : if (!do_pre && !do_post)
1769 : return false;
1770 :
1771 :
1772 222 : return ((flag_contract_client_check > 1)
1773 222 : || ((flag_contract_client_check > 0)
1774 : && do_pre));
1775 : }
1776 :
1777 : /* Possibly replace call with a call to a wrapper function which
1778 : will do the contracts check required around a CALL to FNDECL. */
1779 :
1780 : tree
1781 153425681 : maybe_contract_wrap_call (tree fndecl, tree call)
1782 : {
1783 : /* We can be called from build_cxx_call without a known callee. */
1784 153425681 : if (!fndecl)
1785 : return call;
1786 :
1787 146937741 : if (error_operand_p (fndecl) || !call || call == error_mark_node)
1788 0 : return error_mark_node;
1789 :
1790 146937741 : if (!handle_contracts_p (fndecl))
1791 : return call;
1792 :
1793 222 : bool do_pre = has_active_preconditions (fndecl);
1794 222 : bool do_post = has_active_postconditions (fndecl);
1795 :
1796 : /* Check if we need a wrapper. */
1797 153425884 : if (!should_contract_wrap_call (do_pre, do_post))
1798 : return call;
1799 :
1800 : /* Build the declaration of the wrapper, if we need to. */
1801 22 : tree wrapdecl = get_or_create_contract_wrapper_function (fndecl);
1802 :
1803 22 : unsigned nargs = call_expr_nargs (call);
1804 22 : vec<tree, va_gc> *argwrap;
1805 22 : vec_alloc (argwrap, nargs);
1806 :
1807 22 : tree arg;
1808 22 : call_expr_arg_iterator iter;
1809 92 : FOR_EACH_CALL_EXPR_ARG (arg, iter, call)
1810 48 : argwrap->quick_push (arg);
1811 :
1812 22 : tree wrapcall = build_call_expr_loc_vec (DECL_SOURCE_LOCATION (wrapdecl),
1813 : wrapdecl, argwrap);
1814 :
1815 22 : return wrapcall;
1816 : }
1817 :
1818 : /* Map traversal callback to define a wrapper function.
1819 : This generates code for client-side contract check wrappers and the
1820 : noexcept wrapper around the contract violation handler. */
1821 :
1822 : bool
1823 48 : define_contract_wrapper_func (const tree& fndecl, const tree& wrapdecl, void*)
1824 : {
1825 : /* If we already built this function on a previous pass, then do nothing. */
1826 48 : if (DECL_INITIAL (wrapdecl) && DECL_INITIAL (wrapdecl) != error_mark_node)
1827 : return true;
1828 :
1829 22 : gcc_checking_assert (!DECL_HAS_CONTRACTS_P (wrapdecl));
1830 : /* We check postconditions if postcondition checks are enabled for clients.
1831 : We should not get here unless there are some checks to make. */
1832 22 : bool check_post = flag_contract_client_check > 1;
1833 : /* For wrappers on CDTORs we need to refer to the original contracts,
1834 : when the wrapper is around a clone. */
1835 44 : set_fn_contract_specifiers ( wrapdecl,
1836 22 : copy_and_remap_contracts (wrapdecl, DECL_ORIGIN (fndecl),
1837 : check_post? cmk_all : cmk_pre));
1838 :
1839 22 : start_preparsed_function (wrapdecl, /*DECL_ATTRIBUTES*/NULL_TREE,
1840 : SF_DEFAULT | SF_PRE_PARSED);
1841 22 : tree body = begin_function_body ();
1842 22 : tree compound_stmt = begin_compound_stmt (BCS_FN_BODY);
1843 :
1844 22 : vec<tree, va_gc> * args = build_arg_list (wrapdecl);
1845 :
1846 : /* We do not support contracts on virtual functions yet. */
1847 22 : gcc_checking_assert (!DECL_IOBJ_MEMBER_FUNCTION_P (fndecl)
1848 : || !DECL_VIRTUAL_P (fndecl));
1849 :
1850 22 : tree call = build_thunk_like_call (fndecl, args->length (), args->address ());
1851 :
1852 22 : finish_return_stmt (call);
1853 :
1854 22 : finish_compound_stmt (compound_stmt);
1855 22 : finish_function_body (body);
1856 22 : expand_or_defer_fn (finish_function (/*inline_p=*/false));
1857 22 : return true;
1858 : }
1859 :
1860 : /* If any wrapper functions have been declared, emit their definition.
1861 : This might be called multiple times, as we instantiate functions. When
1862 : the processing here adds more wrappers, then flag to the caller that
1863 : possible additional instantiations should be considered.
1864 : Once instantiations are complete, this will be called with done == true. */
1865 :
1866 : bool
1867 52505 : emit_contract_wrapper_func (bool done)
1868 : {
1869 52505 : if (!decl_wrapper_fn || decl_wrapper_fn->is_empty ())
1870 : return false;
1871 26 : size_t start_elements = decl_wrapper_fn->elements ();
1872 74 : decl_wrapper_fn->traverse<void *, define_contract_wrapper_func>(NULL);
1873 26 : bool more = decl_wrapper_fn->elements () > start_elements;
1874 26 : if (done)
1875 11 : decl_wrapper_fn->empty ();
1876 11 : gcc_checking_assert (!done || !more);
1877 : return more;
1878 : }
1879 :
1880 : /* Mark most of a contract as being invalid. */
1881 :
1882 : tree
1883 12 : invalidate_contract (tree contract)
1884 : {
1885 12 : if (TREE_CODE (contract) == POSTCONDITION_STMT
1886 12 : && POSTCONDITION_IDENTIFIER (contract))
1887 12 : POSTCONDITION_IDENTIFIER (contract) = error_mark_node;
1888 12 : CONTRACT_CONDITION (contract) = error_mark_node;
1889 12 : CONTRACT_COMMENT (contract) = error_mark_node;
1890 12 : return contract;
1891 : }
1892 :
1893 : /* Returns an invented parameter declaration of the form 'TYPE ID' for the
1894 : purpose of parsing the postcondition.
1895 :
1896 : We use a PARM_DECL instead of a VAR_DECL so that tsubst forces a lookup
1897 : in local specializations when we instantiate these things later. */
1898 :
1899 : tree
1900 131 : make_postcondition_variable (cp_expr id, tree type)
1901 : {
1902 131 : if (id == error_mark_node)
1903 : return id;
1904 131 : gcc_checking_assert (scope_chain && scope_chain->bindings
1905 : && scope_chain->bindings->kind == sk_contract);
1906 :
1907 131 : tree decl = build_lang_decl (PARM_DECL, id, type);
1908 131 : DECL_ARTIFICIAL (decl) = true;
1909 131 : DECL_SOURCE_LOCATION (decl) = id.get_location ();
1910 131 : return pushdecl (decl);
1911 : }
1912 :
1913 : /* As above, except that the type is unknown. */
1914 :
1915 : tree
1916 79 : make_postcondition_variable (cp_expr id)
1917 : {
1918 79 : return make_postcondition_variable (id, make_auto ());
1919 : }
1920 :
1921 : /* Check that the TYPE is valid for a named postcondition variable on
1922 : function decl FNDECL. Emit a diagnostic if it is not. Returns TRUE if
1923 : the result is OK and false otherwise. */
1924 :
1925 : bool
1926 205 : check_postcondition_result (tree fndecl, tree type, location_t loc)
1927 : {
1928 : /* Do not be confused by targetm.cxx.cdtor_return_this ();
1929 : conceptually, cdtors have no return value. */
1930 205 : if (VOID_TYPE_P (type)
1931 390 : || DECL_CONSTRUCTOR_P (fndecl)
1932 400 : || DECL_DESTRUCTOR_P (fndecl))
1933 : {
1934 30 : error_at (loc,
1935 20 : DECL_CONSTRUCTOR_P (fndecl)
1936 : ? G_("constructor does not return a value to test")
1937 8 : : DECL_DESTRUCTOR_P (fndecl)
1938 8 : ? G_("destructor does not return a value to test")
1939 : : G_("function does not return a value to test"));
1940 10 : return false;
1941 : }
1942 :
1943 : return true;
1944 : }
1945 :
1946 : /* Instantiate each postcondition with the return type to finalize the
1947 : contract specifiers on a function decl FNDECL. */
1948 :
1949 : void
1950 1080 : rebuild_postconditions (tree fndecl)
1951 : {
1952 1080 : if (!fndecl || fndecl == error_mark_node)
1953 : return;
1954 :
1955 1080 : tree type = TREE_TYPE (TREE_TYPE (fndecl));
1956 :
1957 : /* If the return type is undeduced, defer until later. */
1958 1080 : if (TREE_CODE (type) == TEMPLATE_TYPE_PARM)
1959 : return;
1960 :
1961 1005 : tree contract_spec = get_fn_contract_specifiers (fndecl);
1962 2575 : for (; contract_spec ; contract_spec = TREE_CHAIN (contract_spec))
1963 : {
1964 1910 : tree contract = TREE_VALUE (TREE_VALUE (contract_spec));
1965 1910 : if (TREE_CODE (contract) != POSTCONDITION_STMT)
1966 1455 : continue;
1967 1241 : tree condition = CONTRACT_CONDITION (contract);
1968 1241 : if (!condition || condition == error_mark_node)
1969 2 : continue;
1970 :
1971 : /* If any conditions are deferred, they're all deferred. Note that
1972 : we don't have to instantiate postconditions in that case because
1973 : the type is available through the declaration. */
1974 1239 : if (TREE_CODE (condition) == DEFERRED_PARSE)
1975 340 : return;
1976 :
1977 899 : tree oldvar = POSTCONDITION_IDENTIFIER (contract);
1978 899 : if (!oldvar)
1979 780 : continue;
1980 :
1981 119 : gcc_checking_assert (!DECL_CONTEXT (oldvar)
1982 : || DECL_CONTEXT (oldvar) == fndecl);
1983 119 : DECL_CONTEXT (oldvar) = fndecl;
1984 :
1985 : /* Check the postcondition variable. */
1986 119 : location_t loc = DECL_SOURCE_LOCATION (oldvar);
1987 119 : if (!check_postcondition_result (fndecl, type, loc))
1988 : {
1989 4 : invalidate_contract (contract);
1990 4 : continue;
1991 : }
1992 :
1993 : /* "Instantiate" the result variable using the known type. */
1994 115 : tree newvar = copy_node (oldvar);
1995 115 : TREE_TYPE (newvar) = type;
1996 :
1997 : /* Make parameters and result available for substitution. */
1998 115 : local_specialization_stack stack (lss_copy);
1999 289 : for (tree t = DECL_ARGUMENTS (fndecl); t != NULL_TREE; t = TREE_CHAIN (t))
2000 174 : register_local_identity (t);
2001 115 : register_local_specialization (newvar, oldvar);
2002 :
2003 115 : begin_scope (sk_contract, fndecl);
2004 115 : bool old_pc = processing_postcondition;
2005 115 : processing_postcondition = true;
2006 :
2007 115 : condition = tsubst_expr (condition, make_tree_vec (0),
2008 : tf_warning_or_error, fndecl);
2009 :
2010 : /* Update the contract condition and result. */
2011 115 : POSTCONDITION_IDENTIFIER (contract) = newvar;
2012 115 : CONTRACT_CONDITION (contract) = finish_contract_condition (condition);
2013 115 : processing_postcondition = old_pc;
2014 115 : gcc_checking_assert (scope_chain && scope_chain->bindings
2015 : && scope_chain->bindings->kind == sk_contract);
2016 115 : pop_bindings_and_leave_scope ();
2017 115 : }
2018 : }
2019 :
2020 : /* Make a string of the contract condition, if it is available. */
2021 :
2022 : static tree
2023 1008 : build_comment (cp_expr condition)
2024 : {
2025 : /* Try to get the actual source text for the condition; if that fails pretty
2026 : print the resulting tree. */
2027 1008 : char *str = get_source_text_between (global_dc->get_file_cache (),
2028 : condition.get_start (),
2029 : condition.get_finish ());
2030 1008 : if (!str)
2031 : {
2032 1 : const char *str = expr_to_string (condition);
2033 1 : return build_string_literal (strlen (str) + 1, str);
2034 : }
2035 :
2036 1007 : tree t = build_string_literal (strlen (str) + 1, str);
2037 1007 : free (str);
2038 1007 : return t;
2039 : }
2040 :
2041 : /* Build a contract statement. */
2042 :
2043 : tree
2044 1035 : grok_contract (tree contract_spec, tree mode, tree result, cp_expr condition,
2045 : location_t loc)
2046 : {
2047 1035 : if (condition == error_mark_node)
2048 : return error_mark_node;
2049 :
2050 1018 : tree_code code;
2051 1018 : contract_assertion_kind kind = CAK_INVALID;
2052 1018 : if (id_equal (contract_spec, "contract_assert"))
2053 : {
2054 : code = ASSERTION_STMT;
2055 : kind = CAK_ASSERT;
2056 : }
2057 939 : else if (id_equal (contract_spec, "pre"))
2058 : {
2059 : code = PRECONDITION_STMT;
2060 : kind = CAK_PRE;
2061 : }
2062 523 : else if (id_equal (contract_spec,"post"))
2063 : {
2064 : code = POSTCONDITION_STMT;
2065 : kind = CAK_POST;
2066 : }
2067 : else
2068 0 : gcc_unreachable ();
2069 :
2070 : /* Build the contract. The condition is added later. In the case that
2071 : the contract is deferred, result an plain identifier, not a result
2072 : variable. */
2073 523 : tree contract;
2074 523 : if (code != POSTCONDITION_STMT)
2075 495 : contract = build5_loc (loc, code, void_type_node, mode,
2076 : NULL_TREE, NULL_TREE, NULL_TREE, NULL_TREE);
2077 : else
2078 : {
2079 523 : contract = build_nt (code, mode, NULL_TREE, NULL_TREE,
2080 : NULL_TREE, NULL_TREE, result);
2081 523 : TREE_TYPE (contract) = void_type_node;
2082 523 : SET_EXPR_LOCATION (contract, loc);
2083 : }
2084 :
2085 : /* Determine the assertion kind. */
2086 1018 : CONTRACT_ASSERTION_KIND (contract) = build_int_cst (uint16_type_node, kind);
2087 :
2088 : /* Determine the evaluation semantic. This is now an override, so that if
2089 : not set we will get the default (currently enforce). */
2090 1018 : CONTRACT_EVALUATION_SEMANTIC (contract)
2091 2036 : = build_int_cst (uint16_type_node, (uint16_t)
2092 1018 : flag_contract_evaluation_semantic);
2093 :
2094 : /* If the contract is deferred, don't do anything with the condition. */
2095 1018 : if (TREE_CODE (condition) == DEFERRED_PARSE)
2096 : {
2097 517 : CONTRACT_CONDITION (contract) = condition;
2098 517 : return contract;
2099 : }
2100 :
2101 : /* Generate the comment from the original condition. */
2102 501 : CONTRACT_COMMENT (contract) = build_comment (condition);
2103 :
2104 : /* The condition is converted to bool. */
2105 501 : condition = finish_contract_condition (condition);
2106 :
2107 501 : if (condition == error_mark_node)
2108 : return error_mark_node;
2109 :
2110 499 : CONTRACT_CONDITION (contract) = condition;
2111 :
2112 499 : return contract;
2113 : }
2114 :
2115 : /* Build the contract specifier where IDENTIFIER is one of 'pre',
2116 : 'post' or 'assert' and CONTRACT is the underlying statement. */
2117 :
2118 : tree
2119 938 : finish_contract_specifier (tree identifier, tree contract)
2120 : {
2121 938 : if (contract == error_mark_node)
2122 : return error_mark_node;
2123 :
2124 938 : tree contract_spec = build_tree_list (build_tree_list (NULL_TREE, identifier),
2125 : build_tree_list (NULL_TREE, contract));
2126 :
2127 : /* Mark the contract as dependent if the condition is dependent. */
2128 938 : tree condition = CONTRACT_CONDITION (contract);
2129 938 : if (TREE_CODE (condition) != DEFERRED_PARSE
2130 938 : && value_dependent_expression_p (condition))
2131 87 : ATTR_IS_DEPENDENT (contract_spec) = true;
2132 :
2133 : return contract_spec;
2134 : }
2135 :
2136 : /* Update condition of a late-parsed contract and postcondition variable,
2137 : if any. */
2138 :
2139 : void
2140 507 : update_late_contract (tree contract, tree result, cp_expr condition)
2141 : {
2142 507 : if (TREE_CODE (contract) == POSTCONDITION_STMT)
2143 335 : POSTCONDITION_IDENTIFIER (contract) = result;
2144 :
2145 : /* Generate the comment from the original condition. */
2146 507 : CONTRACT_COMMENT (contract) = build_comment (condition);
2147 :
2148 : /* The condition is converted to bool. */
2149 507 : condition = finish_contract_condition (condition);
2150 507 : CONTRACT_CONDITION (contract) = condition;
2151 507 : }
2152 :
2153 : /* Returns the precondition funtion for FNDECL, or null if not set. */
2154 :
2155 : tree
2156 1784798 : get_precondition_function (tree fndecl)
2157 : {
2158 1784798 : gcc_checking_assert (fndecl);
2159 1784798 : tree *result = hash_map_safe_get (decl_pre_fn, fndecl);
2160 53 : return result ? *result : NULL_TREE;
2161 : }
2162 :
2163 : /* Returns the postcondition funtion for FNDECL, or null if not set. */
2164 :
2165 : tree
2166 1784800 : get_postcondition_function (tree fndecl)
2167 : {
2168 1784800 : gcc_checking_assert (fndecl);
2169 1784800 : tree *result = hash_map_safe_get (decl_post_fn, fndecl);
2170 40 : return result ? *result : NULL_TREE;
2171 : }
2172 :
2173 : /* Set the PRE and POST functions for FNDECL. Note that PRE and POST can
2174 : be null in this case. If so the functions are not recorded. Used by the
2175 : modules code. */
2176 :
2177 : void
2178 459336 : set_contract_functions (tree fndecl, tree pre, tree post)
2179 : {
2180 459336 : if (pre)
2181 0 : set_precondition_function (fndecl, pre);
2182 :
2183 459336 : if (post)
2184 0 : set_postcondition_function (fndecl, post);
2185 459336 : }
2186 :
2187 :
2188 : /* We're compiling the pre/postcondition function CONDFN; remap any FN
2189 : contracts that match CODE and emit them. */
2190 :
2191 : static void
2192 16 : remap_and_emit_conditions (tree fn, tree condfn, tree_code code)
2193 : {
2194 16 : gcc_assert (code == PRECONDITION_STMT || code == POSTCONDITION_STMT);
2195 16 : tree contract_spec = get_fn_contract_specifiers (fn);
2196 38 : for (; contract_spec; contract_spec = TREE_CHAIN (contract_spec))
2197 : {
2198 22 : tree contract = CONTRACT_STATEMENT (contract_spec);
2199 22 : if (TREE_CODE (contract) == code)
2200 : {
2201 18 : contract = copy_node (contract);
2202 18 : if (CONTRACT_CONDITION (contract) != error_mark_node)
2203 18 : remap_contract (fn, condfn, contract, /*duplicate_p=*/false);
2204 18 : emit_contract_statement (contract);
2205 : }
2206 : }
2207 16 : }
2208 :
2209 : /* Finish up the pre & post function definitions for a guarded FNDECL,
2210 : and compile those functions all the way to assembler language output. */
2211 :
2212 : void
2213 157955125 : finish_function_outlined_contracts (tree fndecl)
2214 : {
2215 : /* If the guarded func is either already decided to be ill-formed or is
2216 : not yet complete return early. */
2217 157955125 : if (error_operand_p (fndecl)
2218 157955125 : || !DECL_INITIAL (fndecl)
2219 315910250 : || DECL_INITIAL (fndecl) == error_mark_node)
2220 : return;
2221 :
2222 : /* If there are no contracts here, or we're building them in-line then we
2223 : do not need to build the outlined functions. */
2224 157955035 : if (!handle_contracts_p (fndecl)
2225 157955035 : || !flag_contract_checks_outlined)
2226 : return;
2227 :
2228 : /* If this is not a client side check and definition side checks are
2229 : disabled, do nothing. */
2230 15 : if (!flag_contracts_definition_check
2231 15 : && !DECL_CONTRACT_WRAPPER (fndecl))
2232 : return;
2233 :
2234 : /* If either the pre or post functions are bad, don't bother emitting
2235 : any contracts. The program is already ill-formed. */
2236 15 : tree pre = DECL_PRE_FN (fndecl);
2237 15 : tree post = DECL_POST_FN (fndecl);
2238 15 : if (pre == error_mark_node || post == error_mark_node)
2239 : return;
2240 :
2241 : /* We are generating code, deferred parses should be complete. */
2242 15 : tree contract_spec = get_fn_contract_specifiers (fndecl);
2243 15 : gcc_checking_assert (!contract_any_deferred_p (contract_spec));
2244 :
2245 15 : int flags = SF_DEFAULT | SF_PRE_PARSED;
2246 :
2247 15 : if (pre && !DECL_INITIAL (pre))
2248 : {
2249 8 : DECL_PENDING_INLINE_P (pre) = false;
2250 8 : start_preparsed_function (pre, DECL_ATTRIBUTES (pre), flags);
2251 8 : remap_and_emit_conditions (fndecl, pre, PRECONDITION_STMT);
2252 8 : finish_return_stmt (NULL_TREE);
2253 8 : pre = finish_function (false);
2254 8 : expand_or_defer_fn (pre);
2255 : }
2256 :
2257 15 : if (post && !DECL_INITIAL (post))
2258 : {
2259 8 : DECL_PENDING_INLINE_P (post) = false;
2260 8 : start_preparsed_function (post, DECL_ATTRIBUTES (post), flags);
2261 8 : remap_and_emit_conditions (fndecl, post, POSTCONDITION_STMT);
2262 8 : gcc_checking_assert (VOID_TYPE_P (TREE_TYPE (TREE_TYPE (post))));
2263 8 : finish_return_stmt (NULL_TREE);
2264 8 : post = finish_function (false);
2265 8 : expand_or_defer_fn (post);
2266 : }
2267 : }
2268 :
2269 : /* ===== Code generation ===== */
2270 :
2271 : /* Insert a BUILT_IN_OBSERVABLE_CHECKPOINT epoch marker. */
2272 :
2273 : static void
2274 284 : emit_builtin_observable_checkpoint ()
2275 : {
2276 284 : tree fn = builtin_decl_explicit (BUILT_IN_OBSERVABLE_CHKPT);
2277 284 : releasing_vec vec;
2278 284 : fn = finish_call_expr (fn, &vec, false, false, tf_warning_or_error);
2279 284 : finish_expr_stmt (fn);
2280 284 : }
2281 :
2282 : /* Shared code between TU-local wrappers for the violation handler. */
2283 :
2284 : static tree
2285 210 : declare_one_violation_handler_wrapper (tree fn_name, tree fn_type,
2286 : tree p1_type, tree p2_type)
2287 : {
2288 210 : location_t loc = BUILTINS_LOCATION;
2289 210 : tree fn_decl = build_lang_decl_loc (loc, FUNCTION_DECL, fn_name, fn_type);
2290 210 : DECL_CONTEXT (fn_decl) = FROB_CONTEXT (global_namespace);
2291 210 : DECL_ARTIFICIAL (fn_decl) = true;
2292 210 : DECL_INITIAL (fn_decl) = error_mark_node;
2293 : /* Let the start function code fill in the result decl. */
2294 210 : DECL_RESULT (fn_decl) = NULL_TREE;
2295 : /* Two args violation ref, dynamic info. */
2296 210 : tree parms = cp_build_parm_decl (fn_decl, NULL_TREE, p1_type);
2297 210 : TREE_USED (parms) = true;
2298 210 : DECL_READ_P (parms) = true;
2299 210 : tree p2 = cp_build_parm_decl (fn_decl, NULL_TREE, p2_type);
2300 210 : TREE_USED (p2) = true;
2301 210 : DECL_READ_P (p2) = true;
2302 210 : DECL_CHAIN (parms) = p2;
2303 210 : DECL_ARGUMENTS (fn_decl) = parms;
2304 : /* Make this function internal. */
2305 210 : TREE_PUBLIC (fn_decl) = false;
2306 210 : DECL_EXTERNAL (fn_decl) = false;
2307 210 : DECL_WEAK (fn_decl) = false;
2308 210 : return fn_decl;
2309 : }
2310 :
2311 : static GTY(()) tree tu_has_violation = NULL_TREE;
2312 : static GTY(()) tree tu_has_violation_exception = NULL_TREE;
2313 :
2314 : static void
2315 618 : declare_violation_handler_wrappers ()
2316 : {
2317 618 : if (tu_has_violation && tu_has_violation_exception)
2318 618 : return;
2319 :
2320 105 : iloc_sentinel ils (input_location);
2321 105 : input_location = BUILTINS_LOCATION;
2322 105 : tree v_obj_type = builtin_contract_violation_type;
2323 105 : v_obj_type = cp_build_qualified_type (v_obj_type, TYPE_QUAL_CONST);
2324 105 : v_obj_type = cp_build_reference_type (v_obj_type, /*rval*/false);
2325 105 : tree fn_type = build_function_type_list (void_type_node, v_obj_type,
2326 : uint16_type_node, NULL_TREE);
2327 105 : tree fn_name = get_identifier ("__tu_has_violation_exception");
2328 105 : tu_has_violation_exception
2329 105 : = declare_one_violation_handler_wrapper (fn_name, fn_type, v_obj_type,
2330 : uint16_type_node);
2331 105 : fn_name = get_identifier ("__tu_has_violation");
2332 105 : tu_has_violation
2333 105 : = declare_one_violation_handler_wrapper (fn_name, fn_type, v_obj_type,
2334 : uint16_type_node);
2335 105 : }
2336 :
2337 : static GTY(()) tree tu_terminate_wrapper = NULL_TREE;
2338 :
2339 : /* Declare a noipa wrapper around the call to std::terminate */
2340 :
2341 : static tree
2342 619 : declare_terminate_wrapper ()
2343 : {
2344 619 : if (tu_terminate_wrapper)
2345 : return tu_terminate_wrapper;
2346 :
2347 106 : iloc_sentinel ils (input_location);
2348 106 : input_location = BUILTINS_LOCATION;
2349 :
2350 106 : tree fn_type = build_function_type_list (void_type_node, NULL_TREE);
2351 106 : if (!TREE_NOTHROW (terminate_fn))
2352 0 : fn_type = build_exception_variant (fn_type, noexcept_true_spec);
2353 106 : tree fn_name = get_identifier ("__tu_terminate_wrapper");
2354 :
2355 106 : tu_terminate_wrapper
2356 106 : = build_lang_decl_loc (input_location, FUNCTION_DECL, fn_name, fn_type);
2357 106 : DECL_CONTEXT (tu_terminate_wrapper) = FROB_CONTEXT(global_namespace);
2358 106 : DECL_ARTIFICIAL (tu_terminate_wrapper) = true;
2359 106 : DECL_INITIAL (tu_terminate_wrapper) = error_mark_node;
2360 : /* Let the start function code fill in the result decl. */
2361 106 : DECL_RESULT (tu_terminate_wrapper) = NULL_TREE;
2362 :
2363 : /* Make this function internal. */
2364 106 : TREE_PUBLIC (tu_terminate_wrapper) = false;
2365 106 : DECL_EXTERNAL (tu_terminate_wrapper) = false;
2366 106 : DECL_WEAK (tu_terminate_wrapper) = false;
2367 :
2368 106 : DECL_ATTRIBUTES (tu_terminate_wrapper)
2369 106 : = tree_cons (get_identifier ("noipa"), NULL, NULL_TREE);
2370 106 : cplus_decl_attributes (&tu_terminate_wrapper,
2371 106 : DECL_ATTRIBUTES (tu_terminate_wrapper), 0);
2372 106 : return tu_terminate_wrapper;
2373 106 : }
2374 :
2375 : /* Define a noipa wrapper around the call to std::terminate */
2376 :
2377 : static void
2378 106 : build_terminate_wrapper ()
2379 : {
2380 : /* We should not be trying to build this if we never used it. */
2381 106 : gcc_checking_assert (tu_terminate_wrapper);
2382 :
2383 106 : start_preparsed_function (tu_terminate_wrapper,
2384 106 : DECL_ATTRIBUTES(tu_terminate_wrapper),
2385 : SF_DEFAULT | SF_PRE_PARSED);
2386 106 : tree body = begin_function_body ();
2387 106 : tree compound_stmt = begin_compound_stmt (BCS_FN_BODY);
2388 106 : finish_expr_stmt (build_call_a (terminate_fn, 0, nullptr));
2389 106 : finish_return_stmt (NULL_TREE);
2390 106 : finish_compound_stmt (compound_stmt);
2391 106 : finish_function_body (body);
2392 106 : tu_terminate_wrapper = finish_function (false);
2393 106 : expand_or_defer_fn (tu_terminate_wrapper);
2394 106 : }
2395 :
2396 : /* Lookup a name in std::contracts, or inject it. */
2397 :
2398 : static tree
2399 85 : lookup_std_contracts_type (tree name_id)
2400 : {
2401 85 : tree id_ns = get_identifier ("contracts");
2402 85 : tree ns = lookup_qualified_name (std_node, id_ns);
2403 :
2404 85 : tree res_type = error_mark_node;
2405 85 : if (TREE_CODE (ns) == NAMESPACE_DECL)
2406 2 : res_type = lookup_qualified_name
2407 2 : (ns, name_id, LOOK_want::TYPE | LOOK_want::HIDDEN_FRIEND);
2408 :
2409 85 : if (TREE_CODE (res_type) == TYPE_DECL)
2410 2 : res_type = TREE_TYPE (res_type);
2411 : else
2412 : {
2413 83 : push_nested_namespace (std_node);
2414 83 : push_namespace (id_ns, /*inline*/false);
2415 83 : res_type = make_class_type (RECORD_TYPE);
2416 83 : create_implicit_typedef (name_id, res_type);
2417 83 : DECL_SOURCE_LOCATION (TYPE_NAME (res_type)) = BUILTINS_LOCATION;
2418 83 : DECL_CONTEXT (TYPE_NAME (res_type)) = current_namespace;
2419 83 : pushdecl_namespace_level (TYPE_NAME (res_type), /*hidden*/true);
2420 83 : pop_namespace ();
2421 83 : pop_nested_namespace (std_node);
2422 : }
2423 85 : return res_type;
2424 : }
2425 :
2426 : /* Return handle_contract_violation (), declaring it if needed. */
2427 :
2428 : static tree
2429 210 : declare_handle_contract_violation ()
2430 : {
2431 : /* We may need to declare new types, ensure they are not considered
2432 : attached to a named module. */
2433 210 : auto module_kind_override = make_temp_override
2434 210 : (module_kind, module_kind & ~(MK_PURVIEW | MK_ATTACH | MK_EXPORTING));
2435 210 : tree fnname = get_identifier ("handle_contract_violation");
2436 210 : tree viol_name = get_identifier ("contract_violation");
2437 210 : tree l = lookup_qualified_name (global_namespace, fnname,
2438 : LOOK_want::HIDDEN_FRIEND);
2439 505 : for (tree f: lkp_range (l))
2440 210 : if (TREE_CODE (f) == FUNCTION_DECL)
2441 : {
2442 125 : tree parms = TYPE_ARG_TYPES (TREE_TYPE (f));
2443 125 : if (remaining_arguments (parms) != 1)
2444 0 : continue;
2445 125 : tree parmtype = non_reference (TREE_VALUE (parms));
2446 125 : if (CLASS_TYPE_P (parmtype)
2447 250 : && TYPE_IDENTIFIER (parmtype) == viol_name)
2448 125 : return f;
2449 : }
2450 :
2451 85 : tree violation = lookup_std_contracts_type (viol_name);
2452 85 : tree fntype = NULL_TREE;
2453 85 : tree v_obj_ref = cp_build_qualified_type (violation, TYPE_QUAL_CONST);
2454 85 : v_obj_ref = cp_build_reference_type (v_obj_ref, /*rval*/false);
2455 85 : fntype = build_function_type_list (void_type_node, v_obj_ref, NULL_TREE);
2456 :
2457 85 : push_nested_namespace (global_namespace);
2458 85 : tree fndecl
2459 85 : = build_cp_library_fn_ptr ("handle_contract_violation", fntype, ECF_COLD);
2460 85 : pushdecl_namespace_level (fndecl, /*hiding*/true);
2461 85 : pop_nested_namespace (global_namespace);
2462 :
2463 : /* Build the parameter(s). */
2464 85 : tree parms = cp_build_parm_decl (fndecl, NULL_TREE, v_obj_ref);
2465 85 : TREE_USED (parms) = true;
2466 85 : DECL_READ_P (parms) = true;
2467 85 : DECL_ARGUMENTS (fndecl) = parms;
2468 85 : return fndecl;
2469 210 : }
2470 :
2471 : /* Build the call to handle_contract_violation for VIOLATION. */
2472 :
2473 : static void
2474 210 : build_contract_handler_call (tree violation)
2475 : {
2476 210 : tree violation_fn = declare_handle_contract_violation ();
2477 210 : tree call = build_call_n (violation_fn, 1, violation);
2478 210 : finish_expr_stmt (call);
2479 210 : }
2480 :
2481 : /* If we have emitted any contracts in this TU that will call a violation
2482 : handler, then emit the wrappers for the handler. */
2483 :
2484 : void
2485 23500 : maybe_emit_violation_handler_wrappers ()
2486 : {
2487 : /* We might need the terminate wrapper, even if we do not use the violation
2488 : handler wrappers. */
2489 23500 : if (tu_terminate_wrapper && flag_contracts_conservative_ipa)
2490 106 : build_terminate_wrapper ();
2491 :
2492 23500 : if (!tu_has_violation && !tu_has_violation_exception)
2493 : return;
2494 :
2495 105 : tree terminate_wrapper = terminate_fn;
2496 105 : if (flag_contracts_conservative_ipa)
2497 105 : terminate_wrapper = tu_terminate_wrapper;
2498 :
2499 : /* tu_has_violation */
2500 105 : start_preparsed_function (tu_has_violation, NULL_TREE,
2501 : SF_DEFAULT | SF_PRE_PARSED);
2502 105 : tree body = begin_function_body ();
2503 105 : tree compound_stmt = begin_compound_stmt (BCS_FN_BODY);
2504 105 : tree v = DECL_ARGUMENTS (tu_has_violation);
2505 105 : tree semantic = DECL_CHAIN (v);
2506 :
2507 : /* We are going to call the handler. */
2508 105 : build_contract_handler_call (v);
2509 :
2510 105 : tree if_observe = begin_if_stmt ();
2511 : /* if (observe) return; */
2512 105 : tree cond = build2 (EQ_EXPR, uint16_type_node, semantic,
2513 : build_int_cst (uint16_type_node, (uint16_t)CES_OBSERVE));
2514 105 : finish_if_stmt_cond (cond, if_observe);
2515 105 : emit_builtin_observable_checkpoint ();
2516 105 : finish_then_clause (if_observe);
2517 105 : begin_else_clause (if_observe);
2518 : /* else terminate. */
2519 105 : finish_expr_stmt (build_call_a (terminate_wrapper, 0, nullptr));
2520 105 : finish_else_clause (if_observe);
2521 105 : finish_if_stmt (if_observe);
2522 105 : finish_return_stmt (NULL_TREE);
2523 :
2524 105 : finish_compound_stmt (compound_stmt);
2525 105 : finish_function_body (body);
2526 105 : tu_has_violation = finish_function (false);
2527 105 : expand_or_defer_fn (tu_has_violation);
2528 :
2529 : /* tu_has_violation_exception */
2530 105 : start_preparsed_function (tu_has_violation_exception, NULL_TREE,
2531 : SF_DEFAULT | SF_PRE_PARSED);
2532 105 : body = begin_function_body ();
2533 105 : compound_stmt = begin_compound_stmt (BCS_FN_BODY);
2534 105 : v = DECL_ARGUMENTS (tu_has_violation_exception);
2535 105 : semantic = DECL_CHAIN (v);
2536 105 : location_t loc = DECL_SOURCE_LOCATION (tu_has_violation_exception);
2537 :
2538 105 : tree a_type = strip_top_quals (non_reference (TREE_TYPE (v)));
2539 105 : tree v2 = build_decl (loc, VAR_DECL, NULL_TREE, a_type);
2540 105 : DECL_SOURCE_LOCATION (v2) = loc;
2541 105 : DECL_CONTEXT (v2) = current_function_decl;
2542 105 : DECL_ARTIFICIAL (v2) = true;
2543 105 : layout_decl (v2, 0);
2544 105 : v2 = pushdecl (v2);
2545 105 : add_decl_expr (v2);
2546 105 : tree r = cp_build_init_expr (v2, convert_from_reference (v));
2547 105 : finish_expr_stmt (r);
2548 105 : tree memb = lookup_member (a_type, get_identifier ("_M_detection_mode"),
2549 : /*protect=*/1, /*want_type=*/0, tf_warning_or_error);
2550 105 : r = build_class_member_access_expr (v2, memb, NULL_TREE, false,
2551 : tf_warning_or_error);
2552 105 : r = cp_build_modify_expr
2553 105 : (loc, r, NOP_EXPR,
2554 : build_int_cst (uint16_type_node, (uint16_t)CDM_EVAL_EXCEPTION),
2555 : tf_warning_or_error);
2556 105 : finish_expr_stmt (r);
2557 : /* We are going to call the handler. */
2558 105 : build_contract_handler_call (v);
2559 :
2560 105 : if_observe = begin_if_stmt ();
2561 : /* if (observe) return; */
2562 105 : cond = build2 (EQ_EXPR, uint16_type_node, semantic,
2563 : build_int_cst (uint16_type_node, (uint16_t)CES_OBSERVE));
2564 105 : finish_if_stmt_cond (cond, if_observe);
2565 105 : emit_builtin_observable_checkpoint ();
2566 105 : finish_then_clause (if_observe);
2567 105 : begin_else_clause (if_observe);
2568 : /* else terminate. */
2569 105 : finish_expr_stmt (build_call_a (terminate_wrapper, 0, nullptr));
2570 105 : finish_else_clause (if_observe);
2571 105 : finish_if_stmt (if_observe);
2572 105 : finish_return_stmt (NULL_TREE);
2573 105 : finish_compound_stmt (compound_stmt);
2574 105 : finish_function_body (body);
2575 105 : tu_has_violation_exception = finish_function (false);
2576 105 : expand_or_defer_fn (tu_has_violation_exception);
2577 : }
2578 :
2579 : /* Build a layout-compatible internal version of contract_violation type. */
2580 :
2581 : static tree
2582 23799 : get_contract_violation_fields ()
2583 : {
2584 23799 : tree fields = NULL_TREE;
2585 : /* Must match <contracts>:
2586 : class contract_violation {
2587 : uint16_t _M_version;
2588 : assertion_kind _M_assertion_kind;
2589 : evaluation_semantic _M_evaluation_semantic;
2590 : detection_mode _M_detection_mode;
2591 : const char* _M_comment;
2592 : void *_M_src_loc_ptr;
2593 : __vendor_ext* _M_ext;
2594 : };
2595 : If this changes, also update the initializer in
2596 : build_contract_violation. */
2597 23799 : const tree types[] = { uint16_type_node,
2598 : uint16_type_node,
2599 : uint16_type_node,
2600 : uint16_type_node,
2601 23799 : const_string_type_node,
2602 23799 : ptr_type_node,
2603 : ptr_type_node
2604 23799 : };
2605 23799 : const char *names[] = { "_M_version",
2606 : "_M_assertion_kind",
2607 : "_M_evaluation_semantic",
2608 : "_M_detection_mode",
2609 : "_M_comment",
2610 : "_M_src_loc_ptr",
2611 : "_M_ext",
2612 : };
2613 23799 : unsigned n = 0;
2614 190392 : for (tree type : types)
2615 : {
2616 : /* finish_builtin_struct wants fields chained in reverse. */
2617 166593 : tree next = build_decl (BUILTINS_LOCATION, FIELD_DECL,
2618 166593 : get_identifier(names[n++]), type);
2619 166593 : DECL_CHAIN (next) = fields;
2620 166593 : fields = next;
2621 : }
2622 23799 : return fields;
2623 : }
2624 :
2625 : /* Build a type to represent contract violation objects. */
2626 :
2627 : static tree
2628 23799 : init_builtin_contract_violation_type ()
2629 : {
2630 23799 : if (builtin_contract_violation_type)
2631 : return builtin_contract_violation_type;
2632 :
2633 23799 : tree fields = get_contract_violation_fields ();
2634 :
2635 23799 : iloc_sentinel ils (input_location);
2636 23799 : input_location = BUILTINS_LOCATION;
2637 23799 : builtin_contract_violation_type = make_class_type (RECORD_TYPE);
2638 23799 : finish_builtin_struct (builtin_contract_violation_type,
2639 : "__builtin_contract_violation_type", fields, NULL_TREE);
2640 47598 : CLASSTYPE_AS_BASE (builtin_contract_violation_type)
2641 23799 : = builtin_contract_violation_type;
2642 23799 : DECL_CONTEXT (TYPE_NAME (builtin_contract_violation_type))
2643 23799 : = FROB_CONTEXT (global_namespace);
2644 23799 : CLASSTYPE_LITERAL_P (builtin_contract_violation_type) = true;
2645 23799 : CLASSTYPE_LAZY_COPY_CTOR (builtin_contract_violation_type) = true;
2646 23799 : xref_basetypes (builtin_contract_violation_type, /*bases=*/NULL_TREE);
2647 23799 : DECL_CONTEXT (TYPE_NAME (builtin_contract_violation_type))
2648 23799 : = FROB_CONTEXT (global_namespace);
2649 23799 : DECL_ARTIFICIAL (TYPE_NAME (builtin_contract_violation_type)) = true;
2650 23799 : TYPE_ARTIFICIAL (builtin_contract_violation_type) = true;
2651 23799 : builtin_contract_violation_type
2652 23799 : = cp_build_qualified_type (builtin_contract_violation_type,
2653 : TYPE_QUAL_CONST);
2654 23799 : return builtin_contract_violation_type;
2655 23799 : }
2656 :
2657 : /* Early initialisation of types and functions we will use. */
2658 : void
2659 23799 : init_contracts ()
2660 : {
2661 23799 : init_terminate_fn ();
2662 23799 : init_builtin_contract_violation_type ();
2663 23799 : }
2664 :
2665 : static GTY(()) tree contracts_source_location_impl_type;
2666 :
2667 : /* Build a layout-compatible internal version of source location __impl
2668 : type. */
2669 :
2670 : static tree
2671 105 : get_contracts_source_location_impl_type (tree context = NULL_TREE)
2672 : {
2673 105 : if (contracts_source_location_impl_type)
2674 : return contracts_source_location_impl_type;
2675 :
2676 : /* First see if we have a declaration that we can use. */
2677 105 : tree contracts_source_location_type
2678 105 : = lookup_std_type (get_identifier ("source_location"));
2679 :
2680 105 : if (contracts_source_location_type
2681 105 : && contracts_source_location_type != error_mark_node
2682 210 : && TYPE_FIELDS (contracts_source_location_type))
2683 : {
2684 22 : contracts_source_location_impl_type = get_source_location_impl_type ();
2685 22 : return contracts_source_location_impl_type;
2686 : }
2687 :
2688 : /* We do not, so build the __impl layout equivalent type, which must
2689 : match <source_location>:
2690 : struct __impl
2691 : {
2692 : const char* _M_file_name;
2693 : const char* _M_function_name;
2694 : unsigned _M_line;
2695 : unsigned _M_column;
2696 : }; */
2697 83 : const tree types[] = { const_string_type_node,
2698 : const_string_type_node,
2699 83 : uint_least32_type_node,
2700 83 : uint_least32_type_node };
2701 :
2702 83 : const char *names[] = { "_M_file_name",
2703 : "_M_function_name",
2704 : "_M_line",
2705 : "_M_column",
2706 : };
2707 83 : tree fields = NULL_TREE;
2708 83 : unsigned n = 0;
2709 415 : for (tree type : types)
2710 : {
2711 : /* finish_builtin_struct wants fields chained in reverse. */
2712 332 : tree next = build_decl (BUILTINS_LOCATION, FIELD_DECL,
2713 332 : get_identifier (names[n++]), type);
2714 332 : DECL_CHAIN (next) = fields;
2715 332 : fields = next;
2716 : }
2717 :
2718 83 : iloc_sentinel ils (input_location);
2719 83 : input_location = BUILTINS_LOCATION;
2720 83 : contracts_source_location_impl_type = cxx_make_type (RECORD_TYPE);
2721 83 : finish_builtin_struct (contracts_source_location_impl_type,
2722 : "__impl", fields, NULL_TREE);
2723 83 : DECL_CONTEXT (TYPE_NAME (contracts_source_location_impl_type)) = context;
2724 83 : DECL_ARTIFICIAL (TYPE_NAME (contracts_source_location_impl_type)) = true;
2725 83 : TYPE_ARTIFICIAL (contracts_source_location_impl_type) = true;
2726 83 : contracts_source_location_impl_type
2727 83 : = cp_build_qualified_type (contracts_source_location_impl_type,
2728 : TYPE_QUAL_CONST);
2729 :
2730 83 : return contracts_source_location_impl_type;
2731 83 : }
2732 :
2733 : static tree
2734 618 : get_src_loc_impl_ptr (location_t loc)
2735 : {
2736 618 : if (!contracts_source_location_impl_type)
2737 105 : get_contracts_source_location_impl_type ();
2738 :
2739 618 : tree fndecl = current_function_decl;
2740 : /* We might be an outlined function. */
2741 618 : if (DECL_IS_PRE_FN_P (fndecl) || DECL_IS_POST_FN_P (fndecl))
2742 18 : fndecl = get_orig_for_outlined (fndecl);
2743 : /* We might be a wrapper. */
2744 618 : if (DECL_IS_WRAPPER_FN_P (fndecl))
2745 34 : fndecl = get_orig_func_for_wrapper (fndecl);
2746 :
2747 618 : gcc_checking_assert (fndecl);
2748 618 : tree impl__
2749 618 : = build_source_location_impl (loc, fndecl,
2750 : contracts_source_location_impl_type);
2751 618 : tree p = build_pointer_type (contracts_source_location_impl_type);
2752 618 : return build_fold_addr_expr_with_type_loc (loc, impl__, p);
2753 : }
2754 :
2755 : /* Build a contract_violation layout compatible object. */
2756 :
2757 : /* Constructor. At present, this should always be constant. */
2758 :
2759 : static tree
2760 618 : build_contract_violation_ctor (tree contract)
2761 : {
2762 618 : bool can_be_const = true;
2763 618 : uint16_t version = 1;
2764 : /* Default CDM_PREDICATE_FALSE. */
2765 618 : uint16_t detection_mode = CDM_PREDICATE_FALSE;
2766 :
2767 618 : tree assertion_kind = CONTRACT_ASSERTION_KIND (contract);
2768 618 : if (!assertion_kind || really_constant_p (assertion_kind))
2769 : {
2770 618 : contract_assertion_kind kind = get_contract_assertion_kind (contract);
2771 618 : assertion_kind = build_int_cst (uint16_type_node, kind);
2772 : }
2773 : else
2774 : can_be_const = false;
2775 :
2776 618 : tree eval_semantic = CONTRACT_EVALUATION_SEMANTIC (contract);
2777 618 : gcc_checking_assert (eval_semantic);
2778 618 : if (!really_constant_p (eval_semantic))
2779 0 : can_be_const = false;
2780 :
2781 618 : tree comment = CONTRACT_COMMENT (contract);
2782 618 : if (comment && !really_constant_p (comment))
2783 : can_be_const = false;
2784 :
2785 618 : tree std_src_loc_impl_ptr = CONTRACT_STD_SOURCE_LOC (contract);
2786 618 : if (std_src_loc_impl_ptr)
2787 : {
2788 0 : std_src_loc_impl_ptr = convert_from_reference (std_src_loc_impl_ptr);
2789 0 : if (!really_constant_p (std_src_loc_impl_ptr))
2790 0 : can_be_const = false;
2791 : }
2792 : else
2793 618 : std_src_loc_impl_ptr = get_src_loc_impl_ptr (EXPR_LOCATION (contract));
2794 :
2795 : /* Must match the type layout in builtin_contract_violation_type. */
2796 618 : tree f0 = next_aggregate_field (TYPE_FIELDS (builtin_contract_violation_type));
2797 618 : tree f1 = next_aggregate_field (DECL_CHAIN (f0));
2798 618 : tree f2 = next_aggregate_field (DECL_CHAIN (f1));
2799 618 : tree f3 = next_aggregate_field (DECL_CHAIN (f2));
2800 618 : tree f4 = next_aggregate_field (DECL_CHAIN (f3));
2801 618 : tree f5 = next_aggregate_field (DECL_CHAIN (f4));
2802 618 : tree f6 = next_aggregate_field (DECL_CHAIN (f5));
2803 618 : tree ctor = build_constructor_va
2804 618 : (builtin_contract_violation_type, 7,
2805 618 : f0, build_int_cst (uint16_type_node, version),
2806 : f1, assertion_kind,
2807 : f2, eval_semantic,
2808 618 : f3, build_int_cst (uint16_type_node, detection_mode),
2809 : f4, comment,
2810 : f5, std_src_loc_impl_ptr,
2811 : f6, build_zero_cst (nullptr_type_node)); // __vendor_ext
2812 :
2813 618 : TREE_READONLY (ctor) = true;
2814 618 : if (can_be_const)
2815 618 : TREE_CONSTANT (ctor) = true;
2816 :
2817 618 : return ctor;
2818 : }
2819 :
2820 : /* Build a named TU-local constant of TYPE. */
2821 :
2822 : static tree
2823 618 : contracts_tu_local_named_var (location_t loc, const char *name, tree type)
2824 : {
2825 618 : tree var_ = build_decl (loc, VAR_DECL, NULL, type);
2826 618 : DECL_NAME (var_) = generate_internal_label (name);
2827 618 : TREE_PUBLIC (var_) = false;
2828 618 : DECL_EXTERNAL (var_) = false;
2829 618 : TREE_STATIC (var_) = true;
2830 : /* Compiler-generated. */
2831 618 : DECL_ARTIFICIAL (var_) = true;
2832 618 : TREE_CONSTANT (var_) = true;
2833 618 : layout_decl (var_, 0);
2834 618 : return var_;
2835 : }
2836 :
2837 : /* Create a read-only violation object. */
2838 :
2839 : static tree
2840 618 : build_contract_violation_constant (tree ctor, tree contract)
2841 : {
2842 618 : tree viol_ = contracts_tu_local_named_var
2843 618 : (EXPR_LOCATION (contract), "Lcontract_violation",
2844 : builtin_contract_violation_type);
2845 :
2846 618 : TREE_CONSTANT (viol_) = true;
2847 618 : DECL_INITIAL (viol_) = ctor;
2848 618 : varpool_node::finalize_decl (viol_);
2849 :
2850 618 : return viol_;
2851 : }
2852 :
2853 : /* Helper to replace references to dummy this parameters with references to
2854 : the first argument of the FUNCTION_DECL DATA. */
2855 :
2856 : static tree
2857 2958 : remap_dummy_this_1 (tree *tp, int *, void *data)
2858 : {
2859 2958 : if (!is_this_parameter (*tp))
2860 : return NULL_TREE;
2861 30 : tree fn = (tree)data;
2862 30 : *tp = DECL_ARGUMENTS (fn);
2863 30 : return NULL_TREE;
2864 : }
2865 :
2866 : /* Replace all references to dummy this parameters in EXPR with references to
2867 : the first argument of the FUNCTION_DECL FNDECL. */
2868 :
2869 : static void
2870 619 : remap_dummy_this (tree fndecl, tree *expr)
2871 : {
2872 0 : walk_tree (expr, remap_dummy_this_1, fndecl, NULL);
2873 0 : }
2874 :
2875 : /* Replace uses of user's placeholder var with the actual return value. */
2876 :
2877 : struct replace_tree
2878 : {
2879 : tree from, to;
2880 : };
2881 :
2882 : static tree
2883 1179 : remap_retval_1 (tree *here, int *do_subtree, void *d)
2884 : {
2885 1179 : replace_tree *data = (replace_tree *) d;
2886 :
2887 1179 : if (*here == data->from)
2888 : {
2889 58 : *here = data->to;
2890 58 : *do_subtree = 0;
2891 : }
2892 : else
2893 1121 : *do_subtree = 1;
2894 1179 : return NULL_TREE;
2895 : }
2896 :
2897 : static void
2898 232 : remap_retval (tree fndecl, tree contract)
2899 : {
2900 232 : struct replace_tree data;
2901 232 : data.from = POSTCONDITION_IDENTIFIER (contract);
2902 232 : gcc_checking_assert (DECL_RESULT (fndecl));
2903 232 : data.to = DECL_RESULT (fndecl);
2904 232 : walk_tree (&CONTRACT_CONDITION (contract), remap_retval_1, &data, NULL);
2905 232 : }
2906 :
2907 :
2908 : /* Genericize a CONTRACT tree, but do not attach it to the current context,
2909 : the caller is responsible for that.
2910 : This is called during genericization. */
2911 :
2912 : tree
2913 620 : build_contract_check (tree contract)
2914 : {
2915 620 : contract_evaluation_semantic semantic = get_evaluation_semantic (contract);
2916 620 : bool quick = false;
2917 620 : bool calls_handler = false;
2918 620 : switch (semantic)
2919 : {
2920 1 : case CES_IGNORE:
2921 1 : return void_node;
2922 : case CES_ENFORCE:
2923 : case CES_OBSERVE:
2924 : calls_handler = true;
2925 : break;
2926 1 : case CES_QUICK:
2927 1 : quick = true;
2928 1 : break;
2929 0 : default:
2930 0 : gcc_unreachable ();
2931 : }
2932 :
2933 619 : location_t loc = EXPR_LOCATION (contract);
2934 :
2935 619 : remap_dummy_this (current_function_decl, &CONTRACT_CONDITION (contract));
2936 619 : tree condition = CONTRACT_CONDITION (contract);
2937 619 : if (condition == error_mark_node)
2938 : return NULL_TREE;
2939 :
2940 619 : if (!flag_contract_checks_outlined && POSTCONDITION_P (contract))
2941 : {
2942 232 : remap_retval (current_function_decl, contract);
2943 232 : condition = CONTRACT_CONDITION (contract);
2944 232 : if (condition == error_mark_node)
2945 : return NULL_TREE;
2946 : }
2947 :
2948 619 : tree terminate_wrapper = terminate_fn;
2949 619 : if (flag_contracts_conservative_ipa)
2950 619 : terminate_wrapper = declare_terminate_wrapper ();
2951 619 : if (calls_handler)
2952 618 : declare_violation_handler_wrappers ();
2953 :
2954 619 : bool check_might_throw = (flag_exceptions
2955 619 : && !expr_noexcept_p (condition, tf_none));
2956 :
2957 : /* Build a statement expression to hold a contract check, with the check
2958 : potentially wrapped in a try-catch expr. */
2959 619 : tree cc_bind = build3 (BIND_EXPR, void_type_node, NULL, NULL, NULL);
2960 619 : BIND_EXPR_BODY (cc_bind) = push_stmt_list ();
2961 :
2962 619 : if (TREE_CODE (contract) == ASSERTION_STMT)
2963 74 : emit_builtin_observable_checkpoint ();
2964 619 : tree cond = build_x_unary_op (loc, TRUTH_NOT_EXPR, condition, NULL_TREE,
2965 : tf_warning_or_error);
2966 619 : tree violation;
2967 619 : bool viol_is_var = false;
2968 619 : if (quick)
2969 : /* We will not be calling a handler. */
2970 1 : violation = build_zero_cst (nullptr_type_node);
2971 : else
2972 : {
2973 : /* Build a violation object, with the contract settings. */
2974 618 : tree ctor = build_contract_violation_ctor (contract);
2975 618 : gcc_checking_assert (TREE_CONSTANT (ctor));
2976 618 : violation = build_contract_violation_constant (ctor, contract);
2977 618 : violation = build_address (violation);
2978 : }
2979 :
2980 619 : tree s_const = build_int_cst (uint16_type_node, semantic);
2981 : /* So now do we need a try-catch? */
2982 619 : if (check_might_throw)
2983 : {
2984 : /* This will hold the computed condition. */
2985 120 : tree check_failed = build_decl (loc, VAR_DECL, NULL, boolean_type_node);
2986 120 : DECL_ARTIFICIAL (check_failed) = true;
2987 120 : DECL_IGNORED_P (check_failed) = true;
2988 120 : DECL_CONTEXT (check_failed) = current_function_decl;
2989 120 : layout_decl (check_failed, 0);
2990 120 : add_decl_expr (check_failed);
2991 120 : DECL_CHAIN (check_failed) = BIND_EXPR_VARS (cc_bind);
2992 120 : BIND_EXPR_VARS (cc_bind) = check_failed;
2993 120 : tree check_try = begin_try_block ();
2994 120 : finish_expr_stmt (cp_build_init_expr (check_failed, cond));
2995 120 : finish_try_block (check_try);
2996 :
2997 120 : tree handler = begin_handler ();
2998 120 : finish_handler_parms (NULL_TREE, handler); /* catch (...) */
2999 120 : if (quick)
3000 0 : finish_expr_stmt (build_call_a (terminate_wrapper, 0, nullptr));
3001 : else
3002 : {
3003 120 : if (viol_is_var)
3004 : {
3005 : /* We can update the detection mode here. */
3006 : tree memb
3007 : = lookup_member (builtin_contract_violation_type,
3008 : get_identifier ("_M_detection_mode"),
3009 : 1, 0, tf_warning_or_error);
3010 : tree r = cp_build_indirect_ref (loc, violation, RO_UNARY_STAR,
3011 : tf_warning_or_error);
3012 : r = build_class_member_access_expr (r, memb, NULL_TREE, false,
3013 : tf_warning_or_error);
3014 : r = cp_build_modify_expr
3015 : (loc, r, NOP_EXPR,
3016 : build_int_cst (uint16_type_node, (uint16_t)CDM_EVAL_EXCEPTION),
3017 : tf_warning_or_error);
3018 : finish_expr_stmt (r);
3019 : finish_expr_stmt (build_call_n (tu_has_violation, 2,
3020 : violation, s_const));
3021 : }
3022 : else
3023 : /* We need to make a copy of the violation object to update. */
3024 120 : finish_expr_stmt (build_call_n (tu_has_violation_exception, 2,
3025 : violation, s_const));
3026 : /* If we reach here, we have handled the exception thrown and do not
3027 : need further action. */
3028 120 : tree e = cp_build_modify_expr (loc, check_failed, NOP_EXPR,
3029 : boolean_false_node,
3030 : tf_warning_or_error);
3031 120 : finish_expr_stmt (e);
3032 : }
3033 120 : finish_handler (handler);
3034 120 : finish_handler_sequence (check_try);
3035 120 : cond = check_failed;
3036 120 : BIND_EXPR_VARS (cc_bind) = nreverse (BIND_EXPR_VARS (cc_bind));
3037 : }
3038 :
3039 619 : tree do_check = begin_if_stmt ();
3040 619 : finish_if_stmt_cond (cond, do_check);
3041 619 : if (quick)
3042 1 : finish_expr_stmt (build_call_a (terminate_wrapper, 0, nullptr));
3043 : else
3044 618 : finish_expr_stmt (build_call_n (tu_has_violation, 2, violation, s_const));
3045 619 : finish_then_clause (do_check);
3046 619 : finish_if_stmt (do_check);
3047 :
3048 619 : BIND_EXPR_BODY (cc_bind) = pop_stmt_list (BIND_EXPR_BODY (cc_bind));
3049 619 : return cc_bind;
3050 : }
3051 :
3052 : #include "gt-cp-contracts.h"
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