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 constraints 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
159 108 : contract_valid_p (tree contract)
160 : {
161 108 : return CONTRACT_CONDITION (contract) != error_mark_node;
162 : }
163 :
164 : /* Compare the contract conditions of OLD_CONTRACT and NEW_CONTRACT.
165 : Returns false if the conditions are equivalent, and true otherwise. */
166 :
167 : static bool
168 54 : mismatched_contracts_p (tree old_contract, tree new_contract)
169 : {
170 : /* Different kinds of contracts do not match. */
171 54 : if (TREE_CODE (old_contract) != TREE_CODE (new_contract))
172 : {
173 0 : auto_diagnostic_group d;
174 0 : error_at (EXPR_LOCATION (new_contract),
175 : "mismatched contract specifier in declaration");
176 0 : inform (EXPR_LOCATION (old_contract), "previous contract here");
177 0 : return true;
178 0 : }
179 :
180 : /* A deferred contract tentatively matches. */
181 54 : if (CONTRACT_CONDITION_DEFERRED_P (new_contract))
182 : return false;
183 :
184 : /* Compare the conditions of the contracts. */
185 54 : tree t1 = cp_fully_fold_init (CONTRACT_CONDITION (old_contract));
186 54 : tree t2 = cp_fully_fold_init (CONTRACT_CONDITION (new_contract));
187 :
188 : /* Compare the contracts. */
189 :
190 54 : bool saved_comparing_contracts = comparing_contracts;
191 54 : comparing_contracts = true;
192 54 : bool matching_p = cp_tree_equal (t1, t2);
193 54 : comparing_contracts = saved_comparing_contracts;
194 :
195 54 : if (!matching_p)
196 : {
197 15 : auto_diagnostic_group d;
198 15 : error_at (EXPR_LOCATION (CONTRACT_CONDITION (new_contract)),
199 : "mismatched contract condition in declaration");
200 15 : inform (EXPR_LOCATION (CONTRACT_CONDITION (old_contract)),
201 : "previous contract here");
202 15 : return true;
203 15 : }
204 :
205 : return false;
206 : }
207 :
208 : /* Compare the contract specifiers of OLDDECL and NEWDECL. Returns true
209 : if the contracts match, and false if they differ. */
210 :
211 : static bool
212 57 : match_contract_specifiers (location_t oldloc, tree old_contracts,
213 : location_t newloc, tree new_contracts)
214 : {
215 : /* Contracts only match if they are both specified. */
216 57 : if (!old_contracts || !new_contracts)
217 : return true;
218 :
219 57 : int old_len = TREE_VEC_LENGTH (old_contracts);
220 57 : int new_len = TREE_VEC_LENGTH (new_contracts);
221 :
222 : /* If we don't have the same number, the contracts don't match. */
223 57 : if (old_len != new_len)
224 : {
225 6 : auto_diagnostic_group d;
226 6 : error_at (newloc,
227 : "declaration has a different number of contracts than "
228 : "previously declared");
229 6 : inform (oldloc,
230 : new_len > old_len
231 : ? "previous declaration with fewer contracts here"
232 : : "previous declaration with more contracts here");
233 6 : return false;
234 6 : }
235 :
236 : /* Compare each contract in turn. */
237 90 : for (int ix = 0; ix < MIN (old_len, new_len); ix++)
238 : {
239 54 : tree old_contract = TREE_VEC_ELT (old_contracts, ix);
240 54 : tree new_contract = TREE_VEC_ELT (new_contracts, ix);
241 :
242 : /* If either contract is ill-formed, skip the rest of the comparison,
243 : since we've already diagnosed an error. */
244 54 : if (!contract_valid_p (new_contract) || !contract_valid_p (old_contract))
245 : return false;
246 :
247 54 : if (mismatched_contracts_p (old_contract, new_contract))
248 : return false;
249 : }
250 :
251 :
252 : return true;
253 : }
254 :
255 : /* Return true if CONTRACT is checked under the current semantic. */
256 :
257 : static bool
258 3413 : contract_active_p (tree contract)
259 : {
260 1194 : return get_evaluation_semantic (contract) != CES_IGNORE;
261 : }
262 :
263 : /* Return true if any contract of FNDECL is checked under the
264 : current semantic. */
265 :
266 : static bool
267 62196405 : contract_any_active_p (tree fndecl)
268 : {
269 62196405 : tree contracts = get_fn_contract_specifiers (fndecl);
270 62196405 : if (!contracts)
271 : return false;
272 :
273 2227 : for (tree contract : tree_vec_range (contracts))
274 2219 : if (contract_active_p (contract))
275 2203 : return true;
276 8 : return false;
277 : }
278 :
279 : /* True if FNDECL has any checked contracts whose TREE_CODE is
280 : C. */
281 :
282 : static bool
283 1079114 : has_active_contract_condition (tree fndecl, tree_code c)
284 : {
285 1079114 : tree contracts = get_fn_contract_specifiers (fndecl);
286 1079114 : if (!contracts)
287 : return false;
288 :
289 3452 : for (tree contract : tree_vec_range (contracts))
290 3726 : if (TREE_CODE (contract) == c && contract_active_p (contract))
291 1194 : return true;
292 920 : return false;
293 : }
294 :
295 : /* True if FNDECL has any checked or assumed preconditions. */
296 :
297 : static bool
298 1011 : has_active_preconditions (tree fndecl)
299 : {
300 0 : return has_active_contract_condition (fndecl, PRECONDITION_STMT);
301 : }
302 :
303 : /* True if FNDECL has any checked or assumed postconditions. */
304 :
305 : static bool
306 1078103 : has_active_postconditions (tree fndecl)
307 : {
308 0 : return has_active_contract_condition (fndecl, POSTCONDITION_STMT);
309 : }
310 :
311 : /* Return true if any contract in CONTRACTS is not yet parsed. */
312 :
313 : bool
314 1371 : contract_any_deferred_p (tree contracts)
315 : {
316 1371 : if (!contracts)
317 : return false;
318 :
319 2524 : for (tree contract : tree_vec_range (contracts))
320 1698 : if (CONTRACT_CONDITION_DEFERRED_P (contract))
321 454 : return true;
322 826 : 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 653799139 : handle_contracts_p (tree fndecl)
335 : {
336 653799139 : return (flag_contracts
337 97279826 : && !processing_template_decl
338 62196489 : && (CONTRACT_HELPER (fndecl) == ldf_contract_none)
339 715995544 : && 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
346 752 : retain_decl (tree decl, copy_body_data *)
347 : {
348 752 : return decl;
349 : }
350 :
351 : /* Lookup a name in std::, or inject it. */
352 :
353 : static tree
354 190 : lookup_std_type (tree name_id)
355 : {
356 190 : tree res_type = lookup_qualified_name
357 190 : (std_node, name_id, LOOK_want::TYPE | LOOK_want::HIDDEN_FRIEND);
358 :
359 190 : if (TREE_CODE (res_type) == TYPE_DECL)
360 49 : res_type = TREE_TYPE (res_type);
361 : else
362 : {
363 141 : push_nested_namespace (std_node);
364 141 : res_type = make_class_type (RECORD_TYPE);
365 141 : create_implicit_typedef (name_id, res_type);
366 141 : DECL_SOURCE_LOCATION (TYPE_NAME (res_type)) = BUILTINS_LOCATION;
367 141 : DECL_CONTEXT (TYPE_NAME (res_type)) = current_namespace;
368 141 : pushdecl_namespace_level (TYPE_NAME (res_type), /*hidden*/true);
369 141 : pop_nested_namespace (std_node);
370 : }
371 190 : 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 1036 : get_contract_assertion_kind (tree contract)
379 : {
380 1036 : if (CONTRACT_ASSERTION_KIND (contract))
381 : {
382 1036 : tree s = CONTRACT_ASSERTION_KIND (contract);
383 1036 : tree i = (TREE_CODE (s) == INTEGER_CST) ? s
384 0 : : DECL_INITIAL (STRIP_NOPS (s));
385 1036 : gcc_checking_assert (!type_dependent_expression_p (s) && i);
386 1036 : 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 5415 : get_evaluation_semantic (const_tree contract)
404 : {
405 5415 : if (CONTRACT_EVALUATION_SEMANTIC (contract))
406 : {
407 5415 : tree s = CONTRACT_EVALUATION_SEMANTIC (contract);
408 5415 : tree i = (TREE_CODE (s) == INTEGER_CST) ? s
409 0 : : DECL_INITIAL (STRIP_NOPS (s));
410 5415 : gcc_checking_assert (!type_dependent_expression_p (s) && i);
411 5415 : switch (contract_evaluation_semantic ev =
412 5415 : (contract_evaluation_semantic) tree_to_uhwi (i))
413 : {
414 : /* This needs to be kept in step with any added semantics. */
415 5415 : case CES_IGNORE:
416 5415 : case CES_OBSERVE:
417 5415 : case CES_ENFORCE:
418 5415 : case CES_QUICK:
419 5415 : return ev;
420 : default:
421 : break;
422 : }
423 : }
424 :
425 0 : gcc_unreachable ();
426 : }
427 :
428 : /* Get location of the last contract in CONTRACTS. */
429 :
430 : static location_t
431 1451 : get_contract_end_loc (tree contracts)
432 : {
433 2902 : gcc_checking_assert (contracts && TREE_VEC_LENGTH (contracts) > 0);
434 1451 : tree last = TREE_VEC_ELT (contracts, TREE_VEC_LENGTH (contracts) - 1);
435 1451 : return EXPR_LOCATION (last);
436 : }
437 :
438 : /* Build the contract specifiers for a function from CONTRACTS, which are in
439 : source order. Returns NULL_TREE when there are none. */
440 :
441 : tree
442 22637523 : build_contract_specifiers (vec<tree, va_gc> *contracts)
443 : {
444 22637523 : unsigned len = vec_safe_length (contracts);
445 22637523 : if (!len)
446 : return NULL_TREE;
447 :
448 924 : tree specs = make_tree_vec (len);
449 3343 : for (unsigned ix = 0; ix < len; ix++)
450 1495 : TREE_VEC_ELT (specs, ix) = (*contracts)[ix];
451 : return specs;
452 : }
453 :
454 : /* Append the contract specifiers in SECOND to those in FIRST, either of
455 : which may be NULL_TREE. Neither input is modified. */
456 :
457 : tree
458 22792644 : contract_specifiers_concat (tree first, tree second)
459 : {
460 22792644 : if (!first)
461 : return second;
462 0 : if (!second)
463 : return first;
464 :
465 0 : int flen = TREE_VEC_LENGTH (first);
466 0 : int slen = TREE_VEC_LENGTH (second);
467 0 : tree specs = make_tree_vec (flen + slen);
468 0 : for (int ix = 0; ix < flen; ix++)
469 0 : TREE_VEC_ELT (specs, ix) = TREE_VEC_ELT (first, ix);
470 0 : for (int ix = 0; ix < slen; ix++)
471 0 : TREE_VEC_ELT (specs, flen + ix) = TREE_VEC_ELT (second, ix);
472 : return specs;
473 : }
474 :
475 : struct GTY(()) contract_decl
476 : {
477 : tree contract_specifiers;
478 : location_t note_loc;
479 : };
480 :
481 : static GTY(()) hash_map<tree, contract_decl> *contract_decl_map;
482 :
483 : /* Converts a contract condition to bool and ensures it has a location. */
484 :
485 : tree
486 2205 : finish_contract_condition (cp_expr condition)
487 : {
488 2205 : if (!condition || error_operand_p (condition))
489 : return condition;
490 :
491 : /* Ensure we have the condition location saved in case we later need to
492 : emit a conversion error during template instantiation and wouldn't
493 : otherwise have it. This differs from maybe_wrap_with_location in that
494 : it allows wrappers on EXCEPTIONAL_CLASS_P which includes CONSTRUCTORs. */
495 2185 : if (!CAN_HAVE_LOCATION_P (condition)
496 121 : && condition.get_location () != UNKNOWN_LOCATION)
497 : {
498 121 : tree_code code
499 117 : = (((CONSTANT_CLASS_P (condition) && TREE_CODE (condition) != STRING_CST)
500 4 : || (TREE_CODE (condition) == CONST_DECL && !TREE_STATIC (condition)))
501 121 : ? NON_LVALUE_EXPR : VIEW_CONVERT_EXPR);
502 121 : condition = build1_loc (condition.get_location (), code,
503 121 : TREE_TYPE (condition), condition);
504 121 : EXPR_LOCATION_WRAPPER_P (condition) = true;
505 : }
506 :
507 2185 : if (type_dependent_expression_p (condition))
508 : return condition;
509 :
510 1643 : return condition_conversion (condition);
511 : }
512 :
513 : /* Wrap the DECL into VIEW_CONVERT_EXPR representing const qualified version
514 : of the declaration. */
515 :
516 : tree
517 3431 : view_as_const (tree decl)
518 : {
519 3431 : if (decl
520 3431 : && !CP_TYPE_CONST_P (TREE_TYPE (decl)))
521 : {
522 2423 : gcc_checking_assert (!contract_const_wrapper_p (decl));
523 2423 : tree ctype = TREE_TYPE (decl);
524 2423 : location_t loc =
525 2423 : EXPR_P (decl) ? EXPR_LOCATION (decl) : DECL_SOURCE_LOCATION (decl);
526 2423 : ctype = cp_build_qualified_type (ctype, (cp_type_quals (ctype)
527 : | TYPE_QUAL_CONST));
528 2423 : decl = build1 (VIEW_CONVERT_EXPR, ctype, decl);
529 2423 : SET_EXPR_LOCATION (decl, loc);
530 : /* Mark the VCE as contract const wrapper. */
531 2423 : CONST_WRAPPER_P (decl) = true;
532 : }
533 3431 : return decl;
534 : }
535 :
536 : /* Constify access to DECL from within the contract condition. */
537 :
538 : tree
539 2615 : constify_contract_access (tree decl)
540 : {
541 : /* We check if we have a variable, a parameter, a variable of reference type,
542 : * or a parameter of reference type
543 : */
544 2615 : if (!TREE_READONLY (decl)
545 2615 : && (VAR_P (decl)
546 2156 : || (TREE_CODE (decl) == PARM_DECL)
547 722 : || (REFERENCE_REF_P (decl)
548 140 : && (VAR_P (TREE_OPERAND (decl, 0))
549 132 : || (TREE_CODE (TREE_OPERAND (decl, 0)) == PARM_DECL)
550 9 : || (TREE_CODE (TREE_OPERAND (decl, 0))
551 : == TEMPLATE_PARM_INDEX)))))
552 1754 : decl = view_as_const (decl);
553 :
554 2615 : return decl;
555 : }
556 :
557 : /* Indicate that PARM_DECL DECL is ODR used in a postcondition. */
558 :
559 : static void
560 728 : set_parm_used_in_post (tree decl, bool constify = true)
561 : {
562 728 : gcc_checking_assert (TREE_CODE (decl) == PARM_DECL);
563 728 : DECL_LANG_FLAG_4 (decl) = constify;
564 728 : }
565 :
566 : /* Test if PARM_DECL is ODR used in a postcondition. */
567 :
568 : static bool
569 785 : parm_used_in_post_p (const_tree decl)
570 : {
571 : /* Check if this parameter is odr used within a function's postcondition */
572 785 : return ((TREE_CODE (decl) == PARM_DECL) && DECL_LANG_FLAG_4 (decl));
573 : }
574 :
575 : /* If declaration DECL is a PARM_DECL and it appears in a postcondition, then
576 : check that it is not a non-const by-value param. LOCATION is where the
577 : expression was found and is used for diagnostic purposes. */
578 :
579 : void
580 751878675 : check_param_in_postcondition (tree decl, location_t location)
581 : {
582 751878675 : if (processing_postcondition
583 1498 : && TREE_CODE (decl) == PARM_DECL
584 : /* TREE_CODE (decl) == PARM_DECL only holds for non-reference
585 : parameters. */
586 907 : && !cp_unevaluated_operand
587 : /* Return value parameter has DECL_ARTIFICIAL flag set. The flag
588 : presence of the flag should be sufficient to distinguish the
589 : return value parameter in this context. */
590 751879366 : && !(DECL_ARTIFICIAL (decl)))
591 : {
592 481 : set_parm_used_in_post (decl);
593 :
594 481 : if (!dependent_type_p (TREE_TYPE (decl))
595 481 : && !CP_TYPE_CONST_P (TREE_TYPE (decl)))
596 : {
597 114 : auto_diagnostic_group d;
598 114 : error_at (location,
599 : "a value parameter used in a postcondition must be const");
600 114 : inform (DECL_SOURCE_LOCATION (decl), "parameter declared here");
601 114 : }
602 : }
603 751878675 : }
604 :
605 : /* Check if parameters used in postconditions are const qualified on
606 : a redeclaration that does not specify contracts or on an instantiation
607 : of a function template. */
608 :
609 : void
610 147971845 : check_postconditions_in_redecl (tree olddecl, tree newdecl)
611 : {
612 147971845 : tree contract_spec = get_fn_contract_specifiers (olddecl);
613 147971845 : if (!contract_spec)
614 : return;
615 :
616 478 : tree t1 = FUNCTION_FIRST_USER_PARM (olddecl);
617 478 : tree t2 = FUNCTION_FIRST_USER_PARM (newdecl);
618 :
619 1741 : for (; t1 && t1 != void_list_node;
620 785 : t1 = TREE_CHAIN (t1), t2 = TREE_CHAIN (t2))
621 : {
622 785 : if (parm_used_in_post_p (t1))
623 : {
624 247 : set_parm_used_in_post (t2);
625 247 : if (!dependent_type_p (TREE_TYPE (t2))
626 193 : && !CP_TYPE_CONST_P (TREE_TYPE (t2))
627 340 : && !TREE_READONLY (t2))
628 : {
629 93 : auto_diagnostic_group d;
630 93 : error_at (DECL_SOURCE_LOCATION (t2),
631 : "value parameter %qE used in a postcondition must be "
632 : "const", t2);
633 93 : inform (DECL_SOURCE_LOCATION (olddecl),
634 : "previous declaration here");
635 93 : }
636 : }
637 : }
638 : }
639 :
640 : /* Map from FUNCTION_DECL to a FUNCTION_DECL for either the PRE_FN or POST_FN.
641 : These are used to parse contract conditions and are called inside the body
642 : of the guarded function. */
643 : static GTY(()) hash_map<tree, tree> *decl_pre_fn;
644 : static GTY(()) hash_map<tree, tree> *decl_post_fn;
645 :
646 : /* Given a pre or post function decl (for an outlined check function) return
647 : the decl for the function for which the outlined checks are being
648 : performed. */
649 : static GTY(()) hash_map<tree, tree> *orig_from_outlined;
650 :
651 : /* Makes PRE the precondition function for FNDECL. */
652 :
653 : static void
654 14 : set_precondition_function (tree fndecl, tree pre)
655 : {
656 14 : gcc_assert (pre);
657 14 : hash_map_maybe_create<hm_ggc> (decl_pre_fn);
658 14 : gcc_checking_assert (!decl_pre_fn->get (fndecl));
659 14 : decl_pre_fn->put (fndecl, pre);
660 :
661 14 : hash_map_maybe_create<hm_ggc> (orig_from_outlined);
662 14 : gcc_checking_assert (!orig_from_outlined->get (pre));
663 14 : orig_from_outlined->put (pre, fndecl);
664 14 : }
665 :
666 : /* Makes POST the postcondition function for FNDECL. */
667 :
668 : static void
669 45 : set_postcondition_function (tree fndecl, tree post)
670 : {
671 45 : gcc_checking_assert (post);
672 45 : hash_map_maybe_create<hm_ggc> (decl_post_fn);
673 45 : gcc_checking_assert (!decl_post_fn->get (fndecl));
674 45 : decl_post_fn->put (fndecl, post);
675 :
676 45 : hash_map_maybe_create<hm_ggc> (orig_from_outlined);
677 45 : gcc_checking_assert (!orig_from_outlined->get (post));
678 45 : orig_from_outlined->put (post, fndecl);
679 45 : }
680 :
681 : /* For a given pre or post condition function, find the checked function. */
682 : tree
683 32 : get_orig_for_outlined (tree fndecl)
684 : {
685 32 : gcc_checking_assert (fndecl);
686 32 : tree *result = hash_map_safe_get (orig_from_outlined, fndecl);
687 32 : return result ? *result : NULL_TREE ;
688 : }
689 :
690 : /* For a given function OLD_FN set suitable names for NEW_FN (which is an
691 : outlined contract check) usually by appending '.pre' or '.post'.
692 :
693 : For functions with special meaning names (i.e. main and cdtors) we need to
694 : make special provisions and therefore handle all the contracts function
695 : name changes here, rather than requiring a separate update to mangle.cc.
696 :
697 : PRE specifies if we need an identifier for a pre or post contract check. */
698 :
699 : static void
700 87 : contracts_fixup_names (tree new_fn, tree old_fn, bool pre, bool wrapper)
701 : {
702 87 : bool cdtor = DECL_CXX_CONSTRUCTOR_P (old_fn)
703 87 : || DECL_CXX_DESTRUCTOR_P (old_fn);
704 87 : const char *fname = IDENTIFIER_POINTER (DECL_NAME (old_fn));
705 132 : const char *append = wrapper ? "contract_wrapper"
706 59 : : (pre ? "pre" : "post");
707 87 : size_t len = strlen (fname);
708 : /* Cdtor names have a space at the end. We need to remove that space
709 : when forming the new identifier. */
710 87 : char *nn = xasprintf ("%.*s%s%s",
711 0 : cdtor ? (int)len-1 : int(len),
712 : fname,
713 : JOIN_STR,
714 : append);
715 87 : DECL_NAME (new_fn) = get_identifier (nn);
716 87 : free (nn);
717 :
718 : /* Now do the mangled version. */
719 87 : fname = IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (old_fn));
720 87 : nn = xasprintf ("%s%s%s", fname, JOIN_STR, append);
721 87 : SET_DECL_ASSEMBLER_NAME (new_fn, get_identifier (nn));
722 87 : free (nn);
723 87 : }
724 :
725 : /* Build a declaration for the pre- or postcondition of a guarded FNDECL. */
726 :
727 : static tree
728 59 : build_contract_condition_function (tree fndecl, bool pre)
729 : {
730 59 : if (error_operand_p (fndecl))
731 0 : return error_mark_node;
732 :
733 : /* Start the copy. */
734 59 : tree fn = copy_decl (fndecl);
735 :
736 : /* Don't propagate declaration attributes to the checking function,
737 : including the original contracts. */
738 59 : DECL_ATTRIBUTES (fn) = NULL_TREE;
739 :
740 : /* If requested, disable optimisation of checking functions; this can, in
741 : some cases, prevent UB from eliding the checks themselves. */
742 59 : if (flag_contract_disable_optimized_checks)
743 0 : DECL_ATTRIBUTES (fn)
744 0 : = tree_cons (get_identifier ("optimize"),
745 : build_tree_list (NULL_TREE, build_string (3, "-O0")),
746 : NULL_TREE);
747 :
748 : /* Now parse and add any internal representation of these attrs to the
749 : decl. */
750 59 : if (DECL_ATTRIBUTES (fn))
751 0 : cplus_decl_attributes (&fn, DECL_ATTRIBUTES (fn), 0);
752 :
753 : /* A possible later optimization may delete unused args to prevent extra arg
754 : passing. */
755 : /* Handle the args list. */
756 59 : tree arg_types = NULL_TREE;
757 59 : tree *last = &arg_types;
758 59 : for (tree arg_type = TYPE_ARG_TYPES (TREE_TYPE (fn));
759 151 : arg_type && arg_type != void_list_node;
760 92 : arg_type = TREE_CHAIN (arg_type))
761 : {
762 92 : if (DECL_IOBJ_MEMBER_FUNCTION_P (fndecl)
763 92 : && TYPE_ARG_TYPES (TREE_TYPE (fn)) == arg_type)
764 36 : continue;
765 56 : *last = build_tree_list (TREE_PURPOSE (arg_type), TREE_VALUE (arg_type));
766 56 : last = &TREE_CHAIN (*last);
767 : }
768 :
769 : /* Copy the function parameters, if present. Disable warnings for them. */
770 59 : DECL_ARGUMENTS (fn) = NULL_TREE;
771 59 : if (DECL_ARGUMENTS (fndecl))
772 : {
773 54 : tree *last_a = &DECL_ARGUMENTS (fn);
774 146 : for (tree p = DECL_ARGUMENTS (fndecl); p; p = TREE_CHAIN (p))
775 : {
776 92 : *last_a = copy_decl (p);
777 92 : suppress_warning (*last_a);
778 92 : DECL_CONTEXT (*last_a) = fn;
779 92 : last_a = &TREE_CHAIN (*last_a);
780 : }
781 : }
782 :
783 59 : tree orig_fn_value_type = TREE_TYPE (TREE_TYPE (fn));
784 59 : if (!pre && !VOID_TYPE_P (orig_fn_value_type))
785 : {
786 : /* For post contracts that deal with a non-void function, append a
787 : parameter to pass the return value. */
788 35 : tree name = get_identifier ("__r");
789 35 : tree parm = build_lang_decl (PARM_DECL, name, orig_fn_value_type);
790 35 : DECL_CONTEXT (parm) = fn;
791 35 : DECL_ARTIFICIAL (parm) = true;
792 35 : suppress_warning (parm);
793 35 : DECL_ARGUMENTS (fn) = chainon (DECL_ARGUMENTS (fn), parm);
794 35 : *last = build_tree_list (NULL_TREE, orig_fn_value_type);
795 35 : last = &TREE_CHAIN (*last);
796 : }
797 :
798 59 : *last = void_list_node;
799 :
800 59 : tree adjusted_type = NULL_TREE;
801 :
802 : /* The handlers are void fns. */
803 59 : if (DECL_IOBJ_MEMBER_FUNCTION_P (fndecl))
804 36 : adjusted_type = build_method_type_directly (DECL_CONTEXT (fndecl),
805 : void_type_node,
806 : arg_types);
807 : else
808 23 : adjusted_type = build_function_type (void_type_node, arg_types);
809 :
810 : /* If the original function is noexcept, build a noexcept function. */
811 59 : if (flag_exceptions && type_noexcept_p (TREE_TYPE (fndecl)))
812 8 : adjusted_type = build_exception_variant (adjusted_type, noexcept_true_spec);
813 :
814 59 : TREE_TYPE (fn) = adjusted_type;
815 59 : DECL_RESULT (fn) = NULL_TREE; /* Let the start function code fill it in. */
816 :
817 : /* The contract check functions are never a cdtor, nor virtual. */
818 59 : DECL_CXX_DESTRUCTOR_P (fn) = DECL_CXX_CONSTRUCTOR_P (fn) = 0;
819 59 : DECL_VIRTUAL_P (fn) = false;
820 :
821 : /* Append .pre / .post to a usable name for the original function. */
822 59 : contracts_fixup_names (fn, fndecl, pre, /*wrapper*/false);
823 :
824 59 : DECL_INITIAL (fn) = NULL_TREE;
825 104 : CONTRACT_HELPER (fn) = pre ? ldf_contract_pre : ldf_contract_post;
826 : /* We might have a pre/post for a wrapper. */
827 59 : DECL_CONTRACT_WRAPPER (fn) = DECL_CONTRACT_WRAPPER (fndecl);
828 :
829 : /* Make these functions internal if we can, i.e. if the guarded function is
830 : not vague linkage, or if we can put them in a comdat group with the
831 : guarded function. */
832 59 : if (!DECL_WEAK (fndecl) || HAVE_COMDAT_GROUP)
833 : {
834 59 : TREE_PUBLIC (fn) = false;
835 59 : DECL_EXTERNAL (fn) = false;
836 59 : DECL_WEAK (fn) = false;
837 59 : DECL_COMDAT (fn) = false;
838 :
839 : /* We may not have set the comdat group on the guarded function yet.
840 : If we haven't, we'll add this to the same group in comdat_linkage
841 : later. Otherwise, add it to the same comdat group now. */
842 59 : if (DECL_ONE_ONLY (fndecl))
843 : {
844 0 : symtab_node *n = symtab_node::get (fndecl);
845 0 : cgraph_node::get_create (fn)->add_to_same_comdat_group (n);
846 : }
847 :
848 : }
849 :
850 59 : DECL_INTERFACE_KNOWN (fn) = true;
851 59 : DECL_ARTIFICIAL (fn) = true;
852 59 : suppress_warning (fn);
853 :
854 59 : return fn;
855 : }
856 :
857 : /* Build the precondition checking function for FNDECL. */
858 :
859 : static tree
860 26 : build_precondition_function (tree fndecl)
861 : {
862 26 : if (!has_active_preconditions (fndecl))
863 : return NULL_TREE;
864 :
865 14 : return build_contract_condition_function (fndecl, /*pre=*/true);
866 : }
867 :
868 : /* Build the postcondition checking function for FNDECL. If the return
869 : type is undeduced, don't build the function yet. We do that in
870 : apply_deduced_return_type. */
871 :
872 : static tree
873 57 : build_postcondition_function (tree fndecl)
874 : {
875 57 : if (!has_active_postconditions (fndecl))
876 : return NULL_TREE;
877 :
878 45 : tree type = TREE_TYPE (TREE_TYPE (fndecl));
879 45 : if (is_auto (type))
880 : return NULL_TREE;
881 :
882 45 : return build_contract_condition_function (fndecl, /*pre=*/false);
883 : }
884 :
885 : /* If we're outlining the contract, build the functions to do the
886 : precondition and postcondition checks, and associate them with
887 : the function decl FNDECL.
888 : */
889 :
890 : static void
891 26 : build_contract_function_decls (tree fndecl)
892 : {
893 : /* Build the pre/post functions (or not). */
894 26 : if (!get_precondition_function (fndecl))
895 26 : if (tree pre = build_precondition_function (fndecl))
896 14 : set_precondition_function (fndecl, pre);
897 :
898 26 : if (!get_postcondition_function (fndecl))
899 26 : if (tree post = build_postcondition_function (fndecl))
900 14 : set_postcondition_function (fndecl, post);
901 26 : }
902 :
903 : /* Map from FUNCTION_DECL to a FUNCTION_DECL for contract wrapper. */
904 :
905 : static GTY(()) hash_map<tree, tree> *decl_wrapper_fn = nullptr;
906 :
907 : /* Map from the function decl of a wrapper to the function that it wraps. */
908 :
909 : static GTY(()) hash_map<tree, tree> *decl_for_wrapper = nullptr;
910 :
911 : /* Makes wrapper the precondition function for FNDECL. */
912 :
913 : static void
914 28 : set_contract_wrapper_function (tree fndecl, tree wrapper)
915 : {
916 28 : gcc_checking_assert (wrapper && fndecl);
917 28 : hash_map_maybe_create<hm_ggc> (decl_wrapper_fn);
918 28 : gcc_checking_assert (decl_wrapper_fn && !decl_wrapper_fn->get (fndecl));
919 28 : decl_wrapper_fn->put (fndecl, wrapper);
920 :
921 : /* We need to know the wrapped function when composing the diagnostic. */
922 28 : hash_map_maybe_create<hm_ggc> (decl_for_wrapper);
923 28 : gcc_checking_assert (decl_for_wrapper && !decl_for_wrapper->get (wrapper));
924 28 : decl_for_wrapper->put (wrapper, fndecl);
925 28 : }
926 :
927 : /* Returns the wrapper function decl for FNDECL, or null if not set. */
928 :
929 : static tree
930 28 : get_contract_wrapper_function (tree fndecl)
931 : {
932 28 : gcc_checking_assert (fndecl);
933 28 : tree *result = hash_map_safe_get (decl_wrapper_fn, fndecl);
934 13 : return result ? *result : NULL_TREE;
935 : }
936 :
937 : /* Given a wrapper function WRAPPER, find the original function decl. */
938 :
939 : static tree
940 40 : get_orig_func_for_wrapper (tree wrapper)
941 : {
942 40 : gcc_checking_assert (wrapper);
943 40 : tree *result = hash_map_safe_get (decl_for_wrapper, wrapper);
944 40 : return result ? *result : NULL_TREE;
945 : }
946 :
947 : /* Build a declaration for the contract wrapper of a caller FNDECL.
948 : We're making a caller side contract check wrapper. For caller side contract
949 : checks, postconditions are only checked if check_post is true.
950 : Defer the attachment of the contracts to this function until the callee
951 : is non-dependent, or we get cases where the conditions can be non-dependent
952 : but still need tsubst-ing. */
953 :
954 : static tree
955 28 : build_contract_wrapper_function (tree fndecl)
956 : {
957 28 : if (error_operand_p (fndecl))
958 0 : return error_mark_node;
959 :
960 : /* We should not be trying to build wrappers for templates or functions that
961 : are still dependent. */
962 28 : gcc_checking_assert (!processing_template_decl
963 : && !TYPE_DEPENDENT_P (TREE_TYPE (fndecl)));
964 :
965 28 : location_t loc = DECL_SOURCE_LOCATION (fndecl);
966 :
967 : /* Fill in the names later. */
968 28 : tree wrapdecl
969 28 : = build_lang_decl_loc (loc, FUNCTION_DECL, NULL_TREE, TREE_TYPE (fndecl));
970 :
971 : /* Put the wrapper in the same context as the callee. */
972 28 : DECL_CONTEXT (wrapdecl) = DECL_CONTEXT (fndecl);
973 :
974 : /* This declaration is a contract wrapper function. */
975 28 : DECL_CONTRACT_WRAPPER (wrapdecl) = true;
976 :
977 28 : contracts_fixup_names (wrapdecl, fndecl, /*pre*/false, /*wrapper*/true);
978 :
979 28 : DECL_SOURCE_LOCATION (wrapdecl) = loc;
980 : /* The declaration was implicitly generated by the compiler. */
981 28 : DECL_ARTIFICIAL (wrapdecl) = true;
982 : /* Declaration, no definition yet. */
983 28 : DECL_INITIAL (wrapdecl) = NULL_TREE;
984 :
985 : /* Let the start function code fill in the result decl. */
986 28 : DECL_RESULT (wrapdecl) = NULL_TREE;
987 :
988 : /* Copy the function parameters, if present. Suppress (e.g. unused)
989 : warnings on them. */
990 28 : DECL_ARGUMENTS (wrapdecl) = NULL_TREE;
991 28 : if (tree p = DECL_ARGUMENTS (fndecl))
992 : {
993 28 : tree *last_a = &DECL_ARGUMENTS (wrapdecl);
994 87 : for (; p; p = TREE_CHAIN (p))
995 : {
996 59 : *last_a = copy_decl (p);
997 59 : suppress_warning (*last_a);
998 59 : DECL_CONTEXT (*last_a) = wrapdecl;
999 59 : last_a = &TREE_CHAIN (*last_a);
1000 : }
1001 : }
1002 :
1003 : /* Copy selected attributes from the original function. */
1004 28 : TREE_USED (wrapdecl) = TREE_USED (fndecl);
1005 :
1006 : /* Copy any alignment added. */
1007 28 : if (DECL_ALIGN (fndecl))
1008 28 : SET_DECL_ALIGN (wrapdecl, DECL_ALIGN (fndecl));
1009 28 : DECL_USER_ALIGN (wrapdecl) = DECL_USER_ALIGN (fndecl);
1010 :
1011 : /* Make this function internal. */
1012 28 : TREE_PUBLIC (wrapdecl) = false;
1013 28 : DECL_EXTERNAL (wrapdecl) = false;
1014 28 : DECL_WEAK (wrapdecl) = false;
1015 :
1016 : /* We know this is an internal function. */
1017 28 : DECL_INTERFACE_KNOWN (wrapdecl) = true;
1018 28 : return wrapdecl;
1019 : }
1020 :
1021 : static tree
1022 28 : get_or_create_contract_wrapper_function (tree fndecl)
1023 : {
1024 28 : tree wrapdecl = get_contract_wrapper_function (fndecl);
1025 28 : if (!wrapdecl)
1026 : {
1027 28 : wrapdecl = build_contract_wrapper_function (fndecl);
1028 28 : set_contract_wrapper_function (fndecl, wrapdecl);
1029 : }
1030 28 : return wrapdecl;
1031 : }
1032 :
1033 : void
1034 168707840 : start_function_contracts (tree fndecl)
1035 : {
1036 168707840 : if (error_operand_p (fndecl))
1037 : return;
1038 :
1039 168707840 : if (!handle_contracts_p (fndecl))
1040 : return;
1041 :
1042 : /* If this is not a client side check and definition side checks are
1043 : disabled, do nothing. */
1044 608 : if (!flag_contracts_definition_check
1045 608 : && !DECL_CONTRACT_WRAPPER (fndecl))
1046 : return;
1047 :
1048 : /* Check that the postcondition result name, if any, does not shadow a
1049 : function parameter. */
1050 606 : if (tree specs = get_fn_contract_specifiers (fndecl))
1051 1522 : for (tree ca : tree_vec_range (specs))
1052 916 : if (POSTCONDITION_P (ca))
1053 377 : if (tree id = POSTCONDITION_IDENTIFIER (ca))
1054 : {
1055 168 : if (id == error_mark_node)
1056 : {
1057 3 : CONTRACT_CONDITION (ca) = error_mark_node;
1058 3 : continue;
1059 : }
1060 165 : tree r_name = tree_strip_any_location_wrapper (id);
1061 165 : if (TREE_CODE (id) == PARM_DECL)
1062 165 : r_name = DECL_NAME (id);
1063 165 : gcc_checking_assert (r_name
1064 : && TREE_CODE (r_name) == IDENTIFIER_NODE);
1065 165 : tree seen = lookup_name (r_name);
1066 165 : if (seen
1067 3 : && TREE_CODE (seen) == PARM_DECL
1068 168 : && DECL_CONTEXT (seen) == fndecl)
1069 : {
1070 3 : auto_diagnostic_group d;
1071 3 : location_t id_l = location_wrapper_p (id)
1072 3 : ? EXPR_LOCATION (id)
1073 3 : : DECL_SOURCE_LOCATION (id);
1074 3 : location_t co_l = EXPR_LOCATION (ca);
1075 3 : if (id_l != UNKNOWN_LOCATION)
1076 3 : co_l = make_location (id_l, co_l, co_l);
1077 3 : error_at (co_l, "contract postcondition result name shadows a"
1078 : " function parameter");
1079 3 : inform (DECL_SOURCE_LOCATION (seen),
1080 : "parameter declared here");
1081 3 : POSTCONDITION_IDENTIFIER (ca) = error_mark_node;
1082 3 : CONTRACT_CONDITION (ca) = error_mark_node;
1083 3 : }
1084 : }
1085 :
1086 : /* If we are expanding contract assertions inline then no need to declare
1087 : the outline function decls. */
1088 606 : if (!flag_contract_checks_outlined)
1089 : return;
1090 :
1091 : /* Contracts may have just been added without a chance to parse them, though
1092 : we still need the PRE_FN available to generate a call to it. */
1093 : /* Do we already have declarations generated ? */
1094 26 : if (!DECL_PRE_FN (fndecl) && !DECL_POST_FN (fndecl))
1095 26 : build_contract_function_decls (fndecl);
1096 : }
1097 :
1098 : void
1099 1077061 : maybe_update_postconditions (tree fndecl)
1100 : {
1101 : /* Update any postconditions and the postcondition checking function
1102 : as needed. If there are postconditions, we'll use those to rewrite
1103 : return statements to check postconditions. */
1104 1077061 : if (has_active_postconditions (fndecl))
1105 : {
1106 31 : rebuild_postconditions (fndecl);
1107 31 : tree post = build_postcondition_function (fndecl);
1108 31 : set_postcondition_function (fndecl, post);
1109 : }
1110 1077061 : }
1111 :
1112 : /* Build and return an argument list containing all the parameters of the
1113 : (presumably guarded) function decl FNDECL. This can be used to forward
1114 : all of FNDECL arguments to a function taking the same list of arguments
1115 : -- namely the unchecked form of FNDECL.
1116 :
1117 : We use CALL_FROM_THUNK_P instead of forward_parm for forwarding
1118 : semantics. */
1119 :
1120 : static vec<tree, va_gc> *
1121 56 : build_arg_list (tree fndecl)
1122 : {
1123 56 : vec<tree, va_gc> *args = make_tree_vector ();
1124 155 : for (tree t = DECL_ARGUMENTS (fndecl); t; t = DECL_CHAIN (t))
1125 99 : vec_safe_push (args, t);
1126 56 : return args;
1127 : }
1128 :
1129 : /* Build and return a thunk like call to FUNC from CALLER using the supplied
1130 : arguments. The call is like a thunk call in the fact that we do not
1131 : want to create additional copies of the arguments. We can not simply reuse
1132 : the thunk machinery as it does more than we want. More specifically, we
1133 : don't want to mark the calling function as `DECL_THUNK_P` for this
1134 : particular purpose, we only want the special treatment for the parameters
1135 : of the call we are about to generate. We temporarily mark the calling
1136 : function as DECL_THUNK_P so build_call_a does the right thing. */
1137 :
1138 : static tree
1139 56 : build_thunk_like_call (tree func, int n, tree *argarray)
1140 : {
1141 56 : bool old_decl_thunk_p = DECL_THUNK_P (current_function_decl);
1142 56 : LANG_DECL_FN_CHECK (current_function_decl)->thunk_p = true;
1143 :
1144 56 : tree call = build_call_a (func, n, argarray);
1145 :
1146 : /* Revert the `DECL_THUNK_P` flag. */
1147 56 : LANG_DECL_FN_CHECK (current_function_decl)->thunk_p = old_decl_thunk_p;
1148 :
1149 : /* Mark the call as a thunk call to allow for correct gimplification
1150 : of the arguments. */
1151 56 : CALL_FROM_THUNK_P (call) = true;
1152 :
1153 56 : return call;
1154 : }
1155 :
1156 : /* If we have a precondition function and it's valid, call it. */
1157 :
1158 : static void
1159 14 : add_pre_condition_fn_call (tree fndecl)
1160 : {
1161 : /* If we're starting a guarded function with valid contracts, we need to
1162 : insert a call to the pre function. */
1163 14 : gcc_checking_assert (DECL_PRE_FN (fndecl)
1164 : && DECL_PRE_FN (fndecl) != error_mark_node);
1165 :
1166 14 : releasing_vec args = build_arg_list (fndecl);
1167 14 : tree call = build_thunk_like_call (DECL_PRE_FN (fndecl),
1168 14 : args->length (), args->address ());
1169 :
1170 14 : finish_expr_stmt (call);
1171 14 : }
1172 :
1173 : /* Returns the parameter corresponding to the return value of a guarded
1174 : function FNDECL. Returns NULL_TREE if FNDECL has no postconditions or
1175 : is void. */
1176 :
1177 : static tree
1178 14 : get_postcondition_result_parameter (tree fndecl)
1179 : {
1180 14 : if (!fndecl || fndecl == error_mark_node)
1181 : return NULL_TREE;
1182 :
1183 14 : if (VOID_TYPE_P (TREE_TYPE (TREE_TYPE (fndecl))))
1184 : return NULL_TREE;
1185 :
1186 4 : tree post = DECL_POST_FN (fndecl);
1187 4 : if (!post || post == error_mark_node)
1188 : return NULL_TREE;
1189 :
1190 : /* The last param is the return value. */
1191 4 : return tree_last (DECL_ARGUMENTS (post));
1192 : }
1193 :
1194 : /* Build and add a call to the post-condition checking function, when that
1195 : is in use. */
1196 :
1197 : static void
1198 14 : add_post_condition_fn_call (tree fndecl)
1199 : {
1200 14 : gcc_checking_assert (DECL_POST_FN (fndecl)
1201 : && DECL_POST_FN (fndecl) != error_mark_node);
1202 :
1203 14 : releasing_vec args = build_arg_list (fndecl);
1204 14 : if (get_postcondition_result_parameter (fndecl))
1205 4 : vec_safe_push (args, DECL_RESULT (fndecl));
1206 14 : tree call = build_thunk_like_call (DECL_POST_FN (fndecl),
1207 14 : args->length (), args->address ());
1208 14 : finish_expr_stmt (call);
1209 14 : }
1210 :
1211 : /* Copy (possibly a sub-set of) contracts from CONTRACTS on FNDECL. */
1212 :
1213 : static tree
1214 653 : copy_contracts_list (tree contracts, tree fndecl,
1215 : contract_match_kind remap_kind = cmk_all)
1216 : {
1217 653 : if (!contracts)
1218 : return NULL_TREE;
1219 :
1220 653 : auto_vec<tree> copies (TREE_VEC_LENGTH (contracts));
1221 1740 : for (tree contract : tree_vec_range (contracts))
1222 : {
1223 1087 : if ((remap_kind == cmk_pre
1224 619 : && TREE_CODE (contract) == POSTCONDITION_STMT)
1225 991 : || (remap_kind == cmk_post
1226 468 : && TREE_CODE (contract) == PRECONDITION_STMT))
1227 203 : continue;
1228 :
1229 884 : tree c = copy_node (contract);
1230 :
1231 884 : copy_body_data id;
1232 884 : hash_map<tree, tree> decl_map;
1233 :
1234 884 : memset (&id, 0, sizeof (id));
1235 :
1236 884 : id.src_fn = fndecl;
1237 884 : id.dst_fn = fndecl;
1238 884 : id.src_cfun = DECL_STRUCT_FUNCTION (fndecl);
1239 884 : id.decl_map = &decl_map;
1240 :
1241 884 : id.copy_decl = retain_decl;
1242 :
1243 884 : id.transform_call_graph_edges = CB_CGE_DUPLICATE;
1244 884 : id.transform_new_cfg = false;
1245 884 : id.transform_return_to_modify = false;
1246 884 : id.transform_parameter = true;
1247 :
1248 : /* Make sure not to unshare trees behind the front-end's back
1249 : since front-end specific mechanisms may rely on sharing. */
1250 884 : id.regimplify = false;
1251 884 : id.do_not_unshare = true;
1252 884 : id.do_not_fold = true;
1253 :
1254 : /* We're not inside any EH region. */
1255 884 : id.eh_lp_nr = 0;
1256 884 : walk_tree (&CONTRACT_CONDITION (c), copy_tree_body_r, &id, NULL);
1257 :
1258 884 : CONTRACT_COMMENT (c) = copy_node (CONTRACT_COMMENT (c));
1259 :
1260 884 : copies.quick_push (c);
1261 884 : }
1262 :
1263 653 : if (copies.is_empty ())
1264 : return NULL_TREE;
1265 :
1266 653 : tree new_contracts = make_tree_vec (copies.length ());
1267 2190 : for (unsigned ix = 0; ix < copies.length (); ix++)
1268 884 : TREE_VEC_ELT (new_contracts, ix) = copies[ix];
1269 : return new_contracts;
1270 653 : }
1271 :
1272 : /* Returns a copy of FNDECL contracts. This is used when emitting a contract.
1273 : If we were to emit the original contract tree, any folding of the contract
1274 : condition would affect the original contract too. The original contract
1275 : tree needs to be preserved in case it is used to apply to a different
1276 : function (for inheritance or wrapping reasons). */
1277 :
1278 : static tree
1279 653 : copy_contracts (tree fndecl, contract_match_kind remap_kind = cmk_all)
1280 : {
1281 653 : tree contracts = get_fn_contract_specifiers (fndecl);
1282 653 : return copy_contracts_list (contracts, fndecl, remap_kind);
1283 : }
1284 :
1285 : /* Add the contract statement CONTRACT to the current block if valid. */
1286 :
1287 : static bool
1288 916 : emit_contract_statement (tree contract)
1289 : {
1290 : /* Only add valid contracts. */
1291 916 : if (contract == error_mark_node
1292 916 : || CONTRACT_CONDITION (contract) == error_mark_node)
1293 : return false;
1294 :
1295 899 : if (get_evaluation_semantic (contract) == CES_INVALID)
1296 : return false;
1297 :
1298 899 : add_stmt (contract);
1299 899 : return true;
1300 : }
1301 :
1302 : /* Add a call or a direct evaluation of the pre checks. */
1303 :
1304 : static void
1305 427 : apply_preconditions (tree fndecl)
1306 : {
1307 427 : if (flag_contract_checks_outlined)
1308 14 : add_pre_condition_fn_call (fndecl);
1309 : else
1310 : {
1311 413 : if (tree contract_copy = copy_contracts (fndecl, cmk_pre))
1312 936 : for (tree contract : tree_vec_range (contract_copy))
1313 523 : emit_contract_statement (contract);
1314 : }
1315 427 : }
1316 :
1317 : /* Add a call or a direct evaluation of the post checks. */
1318 :
1319 : static void
1320 254 : apply_postconditions (tree fndecl)
1321 : {
1322 254 : if (flag_contract_checks_outlined)
1323 14 : add_post_condition_fn_call (fndecl);
1324 : else
1325 : {
1326 240 : if (tree contract_copy = copy_contracts (fndecl, cmk_post))
1327 601 : for (tree contract : tree_vec_range (contract_copy))
1328 361 : emit_contract_statement (contract);
1329 : }
1330 254 : }
1331 :
1332 : /* Add contract handling to the function in FNDECL.
1333 :
1334 : When we have only pre-conditions, this simply prepends a call (or a direct
1335 : evaluation, for cdtors) to the existing function body.
1336 :
1337 : When we have post conditions we build a try-finally block.
1338 : If the function might throw then the handler in the try-finally is an
1339 : EH_ELSE expression, where the post condition check is applied to the
1340 : non-exceptional path, and an empty statement is added to the EH path. If
1341 : the function has a non-throwing eh spec, then the handler is simply the
1342 : post-condition checker. */
1343 :
1344 : void
1345 151970183 : maybe_apply_function_contracts (tree fndecl)
1346 : {
1347 151970183 : if (!handle_contracts_p (fndecl))
1348 : /* We did nothing and the original function body statement list will be
1349 : popped by our caller. */
1350 : return;
1351 :
1352 : /* If this is not a client side check and definition side checks are
1353 : disabled, do nothing. */
1354 608 : if (!flag_contracts_definition_check
1355 608 : && !DECL_CONTRACT_WRAPPER (fndecl))
1356 : return;
1357 :
1358 606 : bool do_pre = has_active_preconditions (fndecl);
1359 606 : bool do_post = has_active_postconditions (fndecl);
1360 : /* We should not have reached here with nothing to do... */
1361 606 : gcc_checking_assert (do_pre || do_post);
1362 :
1363 : /* If the function is noexcept, the user's written body will be wrapped in a
1364 : MUST_NOT_THROW expression. In that case we leave the MUST_NOT_THROW in
1365 : place and do our replacement inside it. */
1366 606 : tree fnbody;
1367 606 : if (TYPE_NOEXCEPT_P (TREE_TYPE (fndecl)))
1368 : {
1369 42 : tree m_n_t_expr = expr_first (DECL_SAVED_TREE (fndecl));
1370 42 : gcc_checking_assert (TREE_CODE (m_n_t_expr) == MUST_NOT_THROW_EXPR);
1371 42 : fnbody = TREE_OPERAND (m_n_t_expr, 0);
1372 42 : TREE_OPERAND (m_n_t_expr, 0) = push_stmt_list ();
1373 : }
1374 : else
1375 : {
1376 564 : fnbody = DECL_SAVED_TREE (fndecl);
1377 564 : DECL_SAVED_TREE (fndecl) = push_stmt_list ();
1378 : }
1379 :
1380 : /* If we have a lambda with captures, ensure that those captures are in-
1381 : scope for pre and post conditions. */
1382 628 : if (LAMBDA_FUNCTION_P (fndecl)
1383 628 : && TREE_CODE (fnbody) == BIND_EXPR)
1384 : {
1385 0 : tree extract = BIND_EXPR_BODY (fnbody);
1386 0 : BIND_EXPR_BODY (fnbody) = NULL_TREE;
1387 0 : add_stmt (fnbody);
1388 0 : BIND_EXPR_BODY (fnbody) = push_stmt_list ();
1389 0 : fnbody = extract;
1390 : }
1391 :
1392 : /* Now add the pre and post conditions to the existing function body.
1393 : This copies the approach used for function try blocks. */
1394 606 : tree compound_stmt = begin_compound_stmt (0);
1395 606 : current_binding_level->artificial = true;
1396 :
1397 : /* Do not add locations for the synthesised code. */
1398 606 : location_t loc = UNKNOWN_LOCATION;
1399 :
1400 : /* For other cases, we call a function to process the check. */
1401 :
1402 : /* If we have a pre, but not a post, then just emit that and we are done. */
1403 606 : if (!do_post)
1404 : {
1405 352 : apply_preconditions (fndecl);
1406 352 : add_stmt (fnbody);
1407 352 : finish_compound_stmt (compound_stmt);
1408 352 : return;
1409 : }
1410 :
1411 254 : if (do_pre)
1412 : /* Add a precondition call, if we have one. */
1413 75 : apply_preconditions (fndecl);
1414 254 : tree try_fin = build_stmt (loc, TRY_FINALLY_EXPR, fnbody, NULL_TREE);
1415 254 : add_stmt (try_fin);
1416 254 : TREE_OPERAND (try_fin, 1) = push_stmt_list ();
1417 : /* If we have exceptions, and a function that might throw, then add
1418 : an EH_ELSE clause that allows the exception to propagate upwards
1419 : without encountering the post-condition checks. */
1420 254 : if (flag_exceptions && !type_noexcept_p (TREE_TYPE (fndecl)))
1421 : {
1422 240 : tree eh_else = build_stmt (loc, EH_ELSE_EXPR, NULL_TREE, NULL_TREE);
1423 240 : add_stmt (eh_else);
1424 240 : TREE_OPERAND (eh_else, 0) = push_stmt_list ();
1425 240 : apply_postconditions (fndecl);
1426 240 : TREE_OPERAND (eh_else, 0) = pop_stmt_list (TREE_OPERAND (eh_else, 0));
1427 240 : TREE_OPERAND (eh_else, 1) = void_node;
1428 : }
1429 : else
1430 14 : apply_postconditions (fndecl);
1431 254 : TREE_OPERAND (try_fin, 1) = pop_stmt_list (TREE_OPERAND (try_fin, 1));
1432 254 : finish_compound_stmt (compound_stmt);
1433 : /* The DECL_SAVED_TREE stmt list will be popped by our caller. */
1434 : }
1435 :
1436 : /* Rewrite the condition of contract in place, so that references to SRC's
1437 : parameters are updated to refer to DST's parameters. The postcondition
1438 : result variable is left unchanged.
1439 :
1440 : When declarations are merged, we sometimes need to update contracts to
1441 : refer to new parameters.
1442 :
1443 : If DUPLICATE_P is true, this is called by duplicate_decls to rewrite
1444 : contracts in terms of a new set of parameters. This also preserves the
1445 : references to postcondition results, which are not replaced during
1446 : merging. */
1447 :
1448 : static void
1449 356 : remap_contract (tree src, tree dst, tree contract, bool duplicate_p)
1450 : {
1451 356 : copy_body_data id;
1452 356 : hash_map<tree, tree> decl_map;
1453 :
1454 356 : memset (&id, 0, sizeof (id));
1455 356 : id.src_fn = src;
1456 356 : id.dst_fn = dst;
1457 356 : id.src_cfun = DECL_STRUCT_FUNCTION (src);
1458 356 : id.decl_map = &decl_map;
1459 :
1460 : /* If we're merging contracts, don't copy local variables. */
1461 356 : id.copy_decl = duplicate_p ? retain_decl : copy_decl_no_change;
1462 :
1463 356 : id.transform_call_graph_edges = CB_CGE_DUPLICATE;
1464 356 : id.transform_new_cfg = false;
1465 356 : id.transform_return_to_modify = false;
1466 356 : id.transform_parameter = true;
1467 :
1468 : /* Make sure not to unshare trees behind the front-end's back
1469 : since front-end specific mechanisms may rely on sharing. */
1470 356 : id.regimplify = false;
1471 356 : id.do_not_unshare = true;
1472 356 : id.do_not_fold = true;
1473 :
1474 : /* We're not inside any EH region. */
1475 356 : id.eh_lp_nr = 0;
1476 :
1477 356 : bool do_remap = false;
1478 :
1479 : /* Insert parameter remappings. */
1480 356 : gcc_checking_assert (TREE_CODE (src) == FUNCTION_DECL);
1481 356 : gcc_checking_assert (TREE_CODE (dst) == FUNCTION_DECL);
1482 :
1483 356 : int src_num_artificial_args = num_artificial_parms_for (src);
1484 356 : int dst_num_artificial_args = num_artificial_parms_for (dst);
1485 :
1486 356 : for (tree sp = DECL_ARGUMENTS (src), dp = DECL_ARGUMENTS (dst);
1487 1038 : sp || dp;
1488 682 : sp = DECL_CHAIN (sp), dp = DECL_CHAIN (dp))
1489 : {
1490 688 : if (!sp && dp
1491 6 : && TREE_CODE (contract) == POSTCONDITION_STMT
1492 694 : && DECL_CHAIN (dp) == NULL_TREE)
1493 : {
1494 6 : gcc_assert (!duplicate_p);
1495 6 : if (tree result = POSTCONDITION_IDENTIFIER (contract))
1496 : {
1497 6 : gcc_assert (DECL_P (result));
1498 6 : insert_decl_map (&id, result, dp);
1499 6 : do_remap = true;
1500 : }
1501 : break;
1502 : }
1503 682 : gcc_assert (sp && dp);
1504 :
1505 682 : if (sp == dp)
1506 304 : continue;
1507 :
1508 378 : insert_decl_map (&id, sp, dp);
1509 378 : do_remap = true;
1510 :
1511 : /* First artificial arg is *this. We want to remap that. However, we
1512 : want to skip _in_charge param and __vtt_parm. Do so now. */
1513 378 : if (src_num_artificial_args > 0)
1514 : {
1515 113 : while (--src_num_artificial_args,src_num_artificial_args > 0)
1516 0 : sp = DECL_CHAIN (sp);
1517 : }
1518 378 : if (dst_num_artificial_args > 0)
1519 : {
1520 113 : while (--dst_num_artificial_args,dst_num_artificial_args > 0)
1521 0 : dp = DECL_CHAIN (dp);
1522 : }
1523 : }
1524 :
1525 356 : if (!do_remap)
1526 162 : return;
1527 :
1528 194 : walk_tree (&CONTRACT_CONDITION (contract), copy_tree_body_r, &id, NULL);
1529 356 : }
1530 :
1531 : /* Returns a copy of SOURCE contracts where any references to SOURCE's
1532 : PARM_DECLs have been rewritten to the corresponding PARM_DECL in DEST. */
1533 :
1534 : tree
1535 243 : copy_and_remap_contracts (tree dest, tree source,
1536 : contract_match_kind remap_kind)
1537 : {
1538 243 : tree contracts = get_fn_contract_specifiers (source);
1539 243 : if (!contracts)
1540 : return NULL_TREE;
1541 :
1542 243 : auto_vec<tree> copies (TREE_VEC_LENGTH (contracts));
1543 571 : for (tree contract : tree_vec_range (contracts))
1544 : {
1545 328 : if ((remap_kind == cmk_pre
1546 10 : && TREE_CODE (contract) == POSTCONDITION_STMT)
1547 324 : || (remap_kind == cmk_post
1548 0 : && TREE_CODE (contract) == PRECONDITION_STMT))
1549 4 : continue;
1550 :
1551 324 : tree stmt = copy_node (contract);
1552 :
1553 : /* If we have an erroneous postcondition identifier, we also mark the
1554 : condition as invalid so only need to check that. */
1555 324 : if (CONTRACT_CONDITION (stmt) != error_mark_node)
1556 324 : remap_contract (source, dest, stmt, /*duplicate_p=*/true);
1557 :
1558 324 : if (TREE_CODE (stmt) == POSTCONDITION_STMT)
1559 : {
1560 : /* If we have a postcondition return value placeholder, then
1561 : ensure the copied one has the correct context. */
1562 110 : tree var = POSTCONDITION_IDENTIFIER (stmt);
1563 110 : if (var && var != error_mark_node)
1564 24 : DECL_CONTEXT (var) = dest;
1565 : }
1566 :
1567 324 : if (CONTRACT_COMMENT (stmt) != error_mark_node)
1568 324 : CONTRACT_COMMENT (stmt) = copy_node (CONTRACT_COMMENT (stmt));
1569 :
1570 324 : copies.quick_push (stmt);
1571 : }
1572 :
1573 243 : if (copies.is_empty ())
1574 : return NULL_TREE;
1575 :
1576 243 : tree contracts_copy = make_tree_vec (copies.length ());
1577 810 : for (unsigned ix = 0; ix < copies.length (); ix++)
1578 324 : TREE_VEC_ELT (contracts_copy, ix) = copies[ix];
1579 :
1580 : return contracts_copy;
1581 243 : }
1582 :
1583 : /* Set the (maybe) parsed contract specifiers CONTRACTS for DECL.
1584 : CONTRACTS is either NULL_TREE or a TREE_VEC of contract statements. */
1585 :
1586 : void
1587 1788 : set_fn_contract_specifiers (tree decl, tree contracts)
1588 : {
1589 1788 : if (!decl || error_operand_p (decl))
1590 0 : return;
1591 :
1592 1788 : gcc_checking_assert (!contracts || TREE_CODE (contracts) == TREE_VEC);
1593 :
1594 1788 : bool existed = false;
1595 1788 : contract_decl& rd
1596 1788 : = hash_map_safe_get_or_insert<hm_ggc> (contract_decl_map, decl, &existed);
1597 1788 : if (!existed)
1598 : {
1599 : /* This is the first time we encountered this decl, save the location
1600 : for error messages. This will ensure all error messages refer to the
1601 : contracts used for the function. */
1602 1379 : location_t decl_loc = DECL_SOURCE_LOCATION (decl);
1603 1379 : location_t cont_end = decl_loc;
1604 1379 : if (contracts)
1605 1379 : cont_end = get_contract_end_loc (contracts);
1606 1379 : rd.note_loc = make_location (decl_loc, decl_loc, cont_end);
1607 : }
1608 1788 : rd.contract_specifiers = contracts;
1609 : }
1610 :
1611 : /* Update the entry for DECL in the map of contract specifiers with the
1612 : contracts in CONTRACTS. */
1613 :
1614 : void
1615 436 : update_fn_contract_specifiers (tree decl, tree contracts)
1616 : {
1617 436 : if (!decl || error_operand_p (decl))
1618 0 : return;
1619 :
1620 436 : bool existed = false;
1621 436 : contract_decl& rd
1622 436 : = hash_map_safe_get_or_insert<hm_ggc> (contract_decl_map, decl, &existed);
1623 436 : gcc_checking_assert (existed);
1624 :
1625 : /* We should only get here when we parse deferred contracts. */
1626 436 : gcc_checking_assert (!contract_any_deferred_p (contracts));
1627 :
1628 436 : rd.contract_specifiers = contracts;
1629 : }
1630 :
1631 : /* When a decl is about to be removed, then we need to release its content and
1632 : then take it out of the map. */
1633 :
1634 : void
1635 1523343 : remove_decl_with_fn_contracts_specifiers (tree decl)
1636 : {
1637 1523546 : if (contract_decl *p = hash_map_safe_get (contract_decl_map, decl))
1638 : {
1639 164 : p->contract_specifiers = NULL_TREE;
1640 164 : contract_decl_map->remove (decl);
1641 : }
1642 1523343 : }
1643 :
1644 : /* If this function has contract specifiers, then remove them, but leave the
1645 : function registered. */
1646 :
1647 : void
1648 479311 : remove_fn_contract_specifiers (tree decl)
1649 : {
1650 479362 : if (contract_decl *p = hash_map_safe_get (contract_decl_map, decl))
1651 : {
1652 49 : p->contract_specifiers = NULL_TREE;
1653 : }
1654 479311 : }
1655 :
1656 : /* Get the contract specifier list for this DECL if there is one. */
1657 :
1658 : tree
1659 556540940 : get_fn_contract_specifiers (tree decl)
1660 : {
1661 557049325 : if (contract_decl *p = hash_map_safe_get (contract_decl_map, decl))
1662 9140 : return p->contract_specifiers;
1663 : return NULL_TREE;
1664 : }
1665 :
1666 : /* A subroutine of duplicate_decls. Diagnose issues in the redeclaration of
1667 : guarded functions. */
1668 :
1669 : void
1670 19829594 : check_redecl_contract (tree newdecl, tree olddecl)
1671 : {
1672 19829594 : if (!flag_contracts)
1673 : return;
1674 :
1675 1874508 : if (TREE_CODE (newdecl) == TEMPLATE_DECL)
1676 426360 : newdecl = DECL_TEMPLATE_RESULT (newdecl);
1677 1874508 : if (TREE_CODE (olddecl) == TEMPLATE_DECL)
1678 426360 : olddecl = DECL_TEMPLATE_RESULT (olddecl);
1679 :
1680 1874508 : tree new_contracts = get_fn_contract_specifiers (newdecl);
1681 1874508 : tree old_contracts = get_fn_contract_specifiers (olddecl);
1682 :
1683 1874508 : if (!old_contracts && !new_contracts)
1684 : return;
1685 :
1686 : /* We should always be comparing with the 'first' declaration which should
1687 : have been recorded already (if it has contract specifiers). However
1688 : if the new decl is trying to add contracts, that is an error and we do
1689 : not want to create a map entry yet. */
1690 199 : contract_decl *rdp = hash_map_safe_get (contract_decl_map, olddecl);
1691 199 : gcc_checking_assert(rdp || !old_contracts);
1692 :
1693 199 : location_t new_loc = DECL_SOURCE_LOCATION (newdecl);
1694 199 : if (new_contracts && !old_contracts)
1695 : {
1696 15 : auto_diagnostic_group d;
1697 : /* If a re-declaration has contracts, they must be the same as those
1698 : that appear on the first declaration seen (they cannot be added). */
1699 15 : location_t cont_end = get_contract_end_loc (new_contracts);
1700 15 : cont_end = make_location (new_loc, new_loc, cont_end);
1701 15 : error_at (cont_end, "declaration adds contracts to %q#D", olddecl);
1702 15 : inform (DECL_SOURCE_LOCATION (olddecl), "first declared here");
1703 15 : return;
1704 15 : }
1705 :
1706 184 : if (old_contracts && !new_contracts)
1707 : /* We allow re-declarations to omit contracts declared on the initial decl.
1708 : In fact, this is required if the conditions contain lambdas. Check if
1709 : all the parameters are correctly const qualified. */
1710 121 : check_postconditions_in_redecl (olddecl, newdecl);
1711 63 : else if (old_contracts && new_contracts
1712 63 : && !contract_any_deferred_p (old_contracts)
1713 57 : && contract_any_deferred_p (new_contracts)
1714 63 : && DECL_UNIQUE_FRIEND_P (newdecl))
1715 : {
1716 : /* Put the deferred contracts on the olddecl so we parse it when
1717 : we can. */
1718 0 : set_fn_contract_specifiers (olddecl, old_contracts);
1719 : }
1720 63 : else if (contract_any_deferred_p (old_contracts)
1721 63 : || contract_any_deferred_p (new_contracts))
1722 : {
1723 : /* TODO: ignore these and figure out how to process them later. */
1724 : /* Note that a friend declaration has deferred contracts, but the
1725 : declaration of the same function outside the class definition
1726 : doesn't. */
1727 : }
1728 : else
1729 : {
1730 57 : gcc_checking_assert (old_contracts);
1731 57 : location_t cont_end = get_contract_end_loc (new_contracts);
1732 57 : cont_end = make_location (new_loc, new_loc, cont_end);
1733 : /* We have two sets - they should match or we issue a diagnostic. */
1734 57 : match_contract_specifiers (rdp->note_loc, old_contracts,
1735 : cont_end, new_contracts);
1736 : }
1737 :
1738 : return;
1739 : }
1740 :
1741 : /* Update the contracts of DEST to match the argument names from contracts
1742 : of SRC. When we merge two declarations in duplicate_decls, we preserve the
1743 : arguments from the new declaration, if the new declaration is a
1744 : definition. We need to update the contracts accordingly. */
1745 :
1746 : void
1747 12347239 : update_contract_arguments (tree srcdecl, tree destdecl)
1748 : {
1749 12347239 : tree src_contracts = get_fn_contract_specifiers (srcdecl);
1750 12347239 : tree dest_contracts = get_fn_contract_specifiers (destdecl);
1751 :
1752 12347239 : if (!src_contracts && !dest_contracts)
1753 : return;
1754 :
1755 : /* Check if src even has contracts. It is possible that a redeclaration
1756 : does not have contracts. Is this is the case, first apply contracts
1757 : to src. */
1758 130 : if (!src_contracts)
1759 : {
1760 91 : if (contract_any_deferred_p (dest_contracts))
1761 : {
1762 0 : set_fn_contract_specifiers (srcdecl, dest_contracts);
1763 : /* Nothing more to do here. */
1764 0 : return;
1765 : }
1766 : else
1767 91 : set_fn_contract_specifiers
1768 91 : (srcdecl, copy_and_remap_contracts (srcdecl, destdecl));
1769 : }
1770 :
1771 : /* For deferred contracts, we currently copy the tokens from the redeclaration
1772 : onto the decl that will be preserved. This is not ideal because the
1773 : redeclaration may have erroneous contracts.
1774 : For non deferred contracts we currently do copy and remap, which is doing
1775 : more than we need. */
1776 130 : if (contract_any_deferred_p (src_contracts))
1777 6 : set_fn_contract_specifiers (destdecl, src_contracts);
1778 : else
1779 : {
1780 : /* Temporarily rename the arguments to get the right mapping. */
1781 124 : tree tmp_arguments = DECL_ARGUMENTS (destdecl);
1782 124 : DECL_ARGUMENTS (destdecl) = DECL_ARGUMENTS (srcdecl);
1783 124 : set_fn_contract_specifiers (destdecl,
1784 : copy_and_remap_contracts (destdecl, srcdecl));
1785 124 : DECL_ARGUMENTS (destdecl) = tmp_arguments;
1786 : }
1787 : }
1788 :
1789 : /* Checks if a contract check wrapper is needed for fndecl. */
1790 :
1791 : static bool
1792 379 : should_contract_wrap_call (bool do_pre, bool do_post)
1793 : {
1794 : /* Only if the target function actually has any contracts. */
1795 0 : if (!do_pre && !do_post)
1796 : return false;
1797 :
1798 :
1799 379 : return ((flag_contract_client_check > 1)
1800 379 : || ((flag_contract_client_check > 0)
1801 : && do_pre));
1802 : }
1803 :
1804 : /* Possibly replace call with a call to a wrapper function which
1805 : will do the contracts check required around a CALL to FNDECL. */
1806 :
1807 : tree
1808 171124291 : maybe_contract_wrap_call (tree fndecl, tree call)
1809 : {
1810 : /* We can be called from build_cxx_call without a known callee. */
1811 171124291 : if (!fndecl)
1812 : return call;
1813 :
1814 164413405 : if (error_operand_p (fndecl) || !call || call == error_mark_node)
1815 0 : return error_mark_node;
1816 :
1817 164413405 : if (!handle_contracts_p (fndecl))
1818 : return call;
1819 :
1820 379 : bool do_pre = has_active_preconditions (fndecl);
1821 379 : bool do_post = has_active_postconditions (fndecl);
1822 :
1823 : /* Check if we need a wrapper. */
1824 387 : if (!should_contract_wrap_call (do_pre, do_post))
1825 : return call;
1826 :
1827 : /* Build the declaration of the wrapper, if we need to. */
1828 28 : tree wrapdecl = get_or_create_contract_wrapper_function (fndecl);
1829 :
1830 28 : unsigned nargs = call_expr_nargs (call);
1831 28 : vec<tree, va_gc> *argwrap;
1832 28 : vec_alloc (argwrap, nargs);
1833 :
1834 28 : tree arg;
1835 28 : call_expr_arg_iterator iter;
1836 115 : FOR_EACH_CALL_EXPR_ARG (arg, iter, call)
1837 59 : argwrap->quick_push (arg);
1838 :
1839 28 : tree wrapcall = build_call_expr_loc_vec (DECL_SOURCE_LOCATION (wrapdecl),
1840 : wrapdecl, argwrap);
1841 :
1842 28 : return wrapcall;
1843 : }
1844 :
1845 : /* Map traversal callback to define a wrapper function.
1846 : This generates code for client-side contract check wrappers and the
1847 : noexcept wrapper around the contract violation handler. */
1848 :
1849 : bool
1850 64 : define_contract_wrapper_func (const tree& fndecl, const tree& wrapdecl, void*)
1851 : {
1852 : /* If we already built this function on a previous pass, then do nothing. */
1853 64 : if (DECL_INITIAL (wrapdecl) && DECL_INITIAL (wrapdecl) != error_mark_node)
1854 : return true;
1855 :
1856 28 : gcc_checking_assert (!DECL_HAS_CONTRACTS_P (wrapdecl));
1857 : /* We check postconditions if postcondition checks are enabled for clients.
1858 : We should not get here unless there are some checks to make. */
1859 28 : bool check_post = flag_contract_client_check > 1;
1860 : /* For wrappers on CDTORs we need to refer to the original contracts,
1861 : when the wrapper is around a clone. */
1862 56 : set_fn_contract_specifiers ( wrapdecl,
1863 28 : copy_and_remap_contracts (wrapdecl, DECL_ORIGIN (fndecl),
1864 : check_post? cmk_all : cmk_pre));
1865 :
1866 28 : start_preparsed_function (wrapdecl, /*DECL_ATTRIBUTES*/NULL_TREE,
1867 : SF_DEFAULT | SF_PRE_PARSED);
1868 28 : tree body = begin_function_body ();
1869 28 : tree compound_stmt = begin_compound_stmt (BCS_FN_BODY);
1870 :
1871 28 : vec<tree, va_gc> * args = build_arg_list (wrapdecl);
1872 :
1873 : /* We do not support contracts on virtual functions yet. */
1874 28 : gcc_checking_assert (!DECL_IOBJ_MEMBER_FUNCTION_P (fndecl)
1875 : || !DECL_VIRTUAL_P (fndecl));
1876 :
1877 28 : tree call = build_thunk_like_call (fndecl, args->length (), args->address ());
1878 :
1879 28 : finish_return_stmt (call);
1880 :
1881 28 : finish_compound_stmt (compound_stmt);
1882 28 : finish_function_body (body);
1883 28 : expand_or_defer_fn (finish_function (/*inline_p=*/false));
1884 28 : return true;
1885 : }
1886 :
1887 : /* If any wrapper functions have been declared, emit their definition.
1888 : This might be called multiple times, as we instantiate functions. When
1889 : the processing here adds more wrappers, then flag to the caller that
1890 : possible additional instantiations should be considered.
1891 : Once instantiations are complete, this will be called with done == true. */
1892 :
1893 : bool
1894 57334 : emit_contract_wrapper_func (bool done)
1895 : {
1896 57334 : if (!decl_wrapper_fn || decl_wrapper_fn->is_empty ())
1897 : return false;
1898 38 : size_t start_elements = decl_wrapper_fn->elements ();
1899 102 : decl_wrapper_fn->traverse<void *, define_contract_wrapper_func>(NULL);
1900 38 : bool more = decl_wrapper_fn->elements () > start_elements;
1901 38 : if (done)
1902 15 : decl_wrapper_fn->empty ();
1903 15 : gcc_checking_assert (!done || !more);
1904 : return more;
1905 : }
1906 :
1907 : /* Mark most of a contract as being invalid. */
1908 :
1909 : tree
1910 15 : invalidate_contract (tree contract)
1911 : {
1912 15 : if (TREE_CODE (contract) == POSTCONDITION_STMT
1913 15 : && POSTCONDITION_IDENTIFIER (contract))
1914 15 : POSTCONDITION_IDENTIFIER (contract) = error_mark_node;
1915 15 : CONTRACT_CONDITION (contract) = error_mark_node;
1916 15 : CONTRACT_COMMENT (contract) = error_mark_node;
1917 15 : return contract;
1918 : }
1919 :
1920 : /* Returns an invented parameter declaration of the form 'TYPE ID' for the
1921 : purpose of parsing the postcondition.
1922 :
1923 : We use a PARM_DECL instead of a VAR_DECL so that tsubst forces a lookup
1924 : in local specializations when we instantiate these things later. */
1925 :
1926 : tree
1927 202 : make_postcondition_variable (cp_expr id, tree type)
1928 : {
1929 202 : if (id == error_mark_node)
1930 : return id;
1931 202 : gcc_checking_assert (scope_chain && scope_chain->bindings
1932 : && scope_chain->bindings->kind == sk_contract);
1933 :
1934 202 : tree decl = build_lang_decl (PARM_DECL, id, type);
1935 202 : DECL_ARTIFICIAL (decl) = true;
1936 202 : DECL_SOURCE_LOCATION (decl) = id.get_location ();
1937 202 : return pushdecl (decl);
1938 : }
1939 :
1940 : /* As above, except that the type is unknown. */
1941 :
1942 : tree
1943 124 : make_postcondition_variable (cp_expr id)
1944 : {
1945 124 : return make_postcondition_variable (id, make_auto ());
1946 : }
1947 :
1948 : /* Check that the TYPE is valid for a named postcondition variable on
1949 : function decl FNDECL. Emit a diagnostic if it is not. Returns TRUE if
1950 : the result is OK and false otherwise. */
1951 :
1952 : bool
1953 254 : check_postcondition_result (tree fndecl, tree type, location_t loc)
1954 : {
1955 : /* Do not be confused by targetm.cxx.cdtor_return_this ();
1956 : conceptually, cdtors have no return value. */
1957 254 : if (VOID_TYPE_P (type)
1958 478 : || DECL_CONSTRUCTOR_P (fndecl)
1959 493 : || DECL_DESTRUCTOR_P (fndecl))
1960 : {
1961 45 : error_at (loc,
1962 30 : DECL_CONSTRUCTOR_P (fndecl)
1963 : ? G_("constructor does not return a value to test")
1964 12 : : DECL_DESTRUCTOR_P (fndecl)
1965 12 : ? G_("destructor does not return a value to test")
1966 : : G_("function does not return a value to test"));
1967 15 : return false;
1968 : }
1969 :
1970 : return true;
1971 : }
1972 :
1973 : /* Instantiate each postcondition with the return type to finalize the
1974 : contract specifiers on a function decl FNDECL. */
1975 :
1976 : void
1977 931 : rebuild_postconditions (tree fndecl)
1978 : {
1979 931 : if (!fndecl || fndecl == error_mark_node || processing_template_decl)
1980 : return;
1981 :
1982 572 : tree type = TREE_TYPE (TREE_TYPE (fndecl));
1983 :
1984 : /* If the return type is undeduced, defer until later. */
1985 572 : if (type_uses_auto (type))
1986 : return;
1987 :
1988 536 : tree contract_spec = get_fn_contract_specifiers (fndecl);
1989 536 : if (!contract_spec)
1990 : return;
1991 :
1992 1173 : for (tree contract : tree_vec_range (contract_spec))
1993 : {
1994 713 : if (TREE_CODE (contract) != POSTCONDITION_STMT)
1995 517 : continue;
1996 266 : tree condition = CONTRACT_CONDITION (contract);
1997 266 : if (!condition || condition == error_mark_node)
1998 0 : continue;
1999 :
2000 : /* If any conditions are deferred, they're all deferred. Note that
2001 : we don't have to instantiate postconditions in that case because
2002 : the type is available through the declaration. */
2003 266 : if (TREE_CODE (condition) == DEFERRED_PARSE)
2004 76 : return;
2005 :
2006 190 : tree oldvar = POSTCONDITION_IDENTIFIER (contract);
2007 190 : if (!oldvar)
2008 67 : continue;
2009 :
2010 123 : gcc_checking_assert (!DECL_CONTEXT (oldvar)
2011 : || DECL_CONTEXT (oldvar) == fndecl);
2012 123 : DECL_CONTEXT (oldvar) = fndecl;
2013 :
2014 : /* Check the postcondition variable. */
2015 123 : location_t loc = DECL_SOURCE_LOCATION (oldvar);
2016 123 : if (!check_postcondition_result (fndecl, type, loc))
2017 : {
2018 3 : invalidate_contract (contract);
2019 3 : continue;
2020 : }
2021 :
2022 : /* A concrete late-parsed result variable still needs validation, but
2023 : not rebuilding. Rebuild only one whose type was undeduced. */
2024 120 : if (!type_uses_auto (TREE_TYPE (oldvar)))
2025 0 : continue;
2026 :
2027 : /* "Instantiate" the result variable using the known type. */
2028 120 : tree newvar = copy_node (oldvar);
2029 120 : TREE_TYPE (newvar) = type;
2030 :
2031 : /* Make parameters and result available for substitution. */
2032 120 : local_specialization_stack stack (lss_copy);
2033 278 : for (tree t = DECL_ARGUMENTS (fndecl); t != NULL_TREE; t = TREE_CHAIN (t))
2034 158 : register_local_identity (t);
2035 120 : register_local_specialization (newvar, oldvar);
2036 :
2037 120 : begin_scope (sk_contract, fndecl);
2038 120 : bool old_pc = processing_postcondition;
2039 120 : processing_postcondition = true;
2040 :
2041 120 : condition = tsubst_expr (condition, make_tree_vec (0),
2042 : tf_warning_or_error, fndecl);
2043 :
2044 : /* Update the contract condition and result. */
2045 120 : POSTCONDITION_IDENTIFIER (contract) = newvar;
2046 120 : CONTRACT_CONDITION (contract) = finish_contract_condition (condition);
2047 120 : processing_postcondition = old_pc;
2048 120 : gcc_checking_assert (scope_chain && scope_chain->bindings
2049 : && scope_chain->bindings->kind == sk_contract);
2050 120 : pop_bindings_and_leave_scope ();
2051 120 : }
2052 : }
2053 :
2054 : /* Make a string of the contract condition, if it is available. */
2055 :
2056 : static tree
2057 1646 : build_comment (cp_expr condition)
2058 : {
2059 : /* Try to get the actual source text for the condition; if that fails pretty
2060 : print the resulting tree. */
2061 1646 : char *str = get_source_text_between (global_dc->get_file_cache (),
2062 : condition.get_start (),
2063 : condition.get_finish ());
2064 1646 : if (!str)
2065 : {
2066 2 : const char *str = expr_to_string (condition);
2067 2 : return build_string_literal (strlen (str) + 1, str);
2068 : }
2069 :
2070 1644 : tree t = build_string_literal (strlen (str) + 1, str);
2071 1644 : free (str);
2072 1644 : return t;
2073 : }
2074 :
2075 : /* Build a contract statement. */
2076 :
2077 : tree
2078 1692 : grok_contract (tree contract_spec, tree mode, tree result, cp_expr condition,
2079 : location_t loc)
2080 : {
2081 1692 : if (condition == error_mark_node)
2082 : return error_mark_node;
2083 :
2084 1661 : tree_code code;
2085 1661 : contract_assertion_kind kind = CAK_INVALID;
2086 1661 : if (id_equal (contract_spec, "contract_assert"))
2087 : {
2088 : code = ASSERTION_STMT;
2089 : kind = CAK_ASSERT;
2090 : }
2091 1497 : else if (id_equal (contract_spec, "pre"))
2092 : {
2093 : code = PRECONDITION_STMT;
2094 : kind = CAK_PRE;
2095 : }
2096 802 : else if (id_equal (contract_spec,"post"))
2097 : {
2098 : code = POSTCONDITION_STMT;
2099 : kind = CAK_POST;
2100 : }
2101 : else
2102 0 : gcc_unreachable ();
2103 :
2104 : /* Build the contract. The condition is added later. In the case that
2105 : the contract is deferred, result an plain identifier, not a result
2106 : variable. */
2107 802 : tree contract;
2108 802 : if (code != POSTCONDITION_STMT)
2109 859 : contract = build5_loc (loc, code, void_type_node, mode,
2110 : NULL_TREE, NULL_TREE, NULL_TREE, NULL_TREE);
2111 : else
2112 : {
2113 802 : contract = build_nt (code, mode, NULL_TREE, NULL_TREE,
2114 : NULL_TREE, NULL_TREE, result);
2115 802 : TREE_TYPE (contract) = void_type_node;
2116 802 : SET_EXPR_LOCATION (contract, loc);
2117 : }
2118 :
2119 : /* Determine the assertion kind. */
2120 1661 : CONTRACT_ASSERTION_KIND (contract) = build_int_cst (uint16_type_node, kind);
2121 :
2122 : /* Determine the evaluation semantic. This is now an override, so that if
2123 : not set we will get the default (currently enforce). */
2124 1661 : CONTRACT_EVALUATION_SEMANTIC (contract)
2125 3322 : = build_int_cst (uint16_type_node, (uint16_t)
2126 1661 : flag_contract_evaluation_semantic);
2127 :
2128 : /* If the contract is deferred, don't do anything with the condition. */
2129 1661 : if (TREE_CODE (condition) == DEFERRED_PARSE)
2130 : {
2131 794 : CONTRACT_CONDITION (contract) = condition;
2132 794 : return contract;
2133 : }
2134 :
2135 : /* Generate the comment from the original condition. */
2136 867 : CONTRACT_COMMENT (contract) = build_comment (condition);
2137 :
2138 : /* The condition is converted to bool. */
2139 867 : condition = finish_contract_condition (condition);
2140 :
2141 867 : if (condition == error_mark_node)
2142 : return error_mark_node;
2143 :
2144 863 : CONTRACT_CONDITION (contract) = condition;
2145 :
2146 863 : return contract;
2147 : }
2148 :
2149 : /* Update condition of a late-parsed contract and postcondition variable,
2150 : if any. */
2151 :
2152 : void
2153 779 : update_late_contract (tree contract, tree result, cp_expr condition)
2154 : {
2155 779 : if (TREE_CODE (contract) == POSTCONDITION_STMT)
2156 507 : POSTCONDITION_IDENTIFIER (contract) = result;
2157 :
2158 : /* Generate the comment from the original condition. */
2159 779 : CONTRACT_COMMENT (contract) = build_comment (condition);
2160 :
2161 : /* The condition is converted to bool. */
2162 779 : condition = finish_contract_condition (condition);
2163 779 : CONTRACT_CONDITION (contract) = condition;
2164 779 : }
2165 :
2166 : /* Returns the precondition function for FNDECL, or null if not set. */
2167 :
2168 : tree
2169 1929326 : get_precondition_function (tree fndecl)
2170 : {
2171 1929326 : gcc_checking_assert (fndecl);
2172 1929326 : tree *result = hash_map_safe_get (decl_pre_fn, fndecl);
2173 90 : return result ? *result : NULL_TREE;
2174 : }
2175 :
2176 : /* Returns the postcondition function for FNDECL, or null if not set. */
2177 :
2178 : tree
2179 1929330 : get_postcondition_function (tree fndecl)
2180 : {
2181 1929330 : gcc_checking_assert (fndecl);
2182 1929330 : tree *result = hash_map_safe_get (decl_post_fn, fndecl);
2183 70 : return result ? *result : NULL_TREE;
2184 : }
2185 :
2186 : /* Set the PRE and POST functions for FNDECL. Note that PRE and POST can
2187 : be null in this case. If so the functions are not recorded. Used by the
2188 : modules code. */
2189 :
2190 : void
2191 472632 : set_contract_functions (tree fndecl, tree pre, tree post)
2192 : {
2193 472632 : if (pre)
2194 0 : set_precondition_function (fndecl, pre);
2195 :
2196 472632 : if (post)
2197 0 : set_postcondition_function (fndecl, post);
2198 472632 : }
2199 :
2200 :
2201 : /* We're compiling the pre/postcondition function CONDFN; remap any FN
2202 : contracts that match CODE and emit them. */
2203 :
2204 : static void
2205 28 : remap_and_emit_conditions (tree fn, tree condfn, tree_code code)
2206 : {
2207 28 : gcc_assert (code == PRECONDITION_STMT || code == POSTCONDITION_STMT);
2208 28 : tree contract_spec = get_fn_contract_specifiers (fn);
2209 28 : if (!contract_spec)
2210 : return;
2211 :
2212 68 : for (tree contract : tree_vec_range (contract_spec))
2213 40 : if (TREE_CODE (contract) == code)
2214 : {
2215 32 : contract = copy_node (contract);
2216 32 : if (CONTRACT_CONDITION (contract) != error_mark_node)
2217 32 : remap_contract (fn, condfn, contract, /*duplicate_p=*/false);
2218 32 : emit_contract_statement (contract);
2219 : }
2220 : }
2221 :
2222 : /* Finish up the pre & post function definitions for a guarded FNDECL,
2223 : and compile those functions all the way to assembler language output. */
2224 :
2225 : void
2226 168707804 : finish_function_outlined_contracts (tree fndecl)
2227 : {
2228 : /* If the guarded func is either already decided to be ill-formed or is
2229 : not yet complete return early. */
2230 168707804 : if (error_operand_p (fndecl)
2231 168707804 : || !DECL_INITIAL (fndecl)
2232 337415608 : || DECL_INITIAL (fndecl) == error_mark_node)
2233 : return;
2234 :
2235 : /* If there are no contracts here, or we're building them in-line then we
2236 : do not need to build the outlined functions. */
2237 168707711 : if (!handle_contracts_p (fndecl)
2238 168707711 : || !flag_contract_checks_outlined)
2239 : return;
2240 :
2241 : /* If this is not a client side check and definition side checks are
2242 : disabled, do nothing. */
2243 26 : if (!flag_contracts_definition_check
2244 26 : && !DECL_CONTRACT_WRAPPER (fndecl))
2245 : return;
2246 :
2247 : /* If either the pre or post functions are bad, don't bother emitting
2248 : any contracts. The program is already ill-formed. */
2249 26 : tree pre = DECL_PRE_FN (fndecl);
2250 26 : tree post = DECL_POST_FN (fndecl);
2251 26 : if (pre == error_mark_node || post == error_mark_node)
2252 : return;
2253 :
2254 : /* We are generating code, deferred parses should be complete. */
2255 26 : tree contract_spec = get_fn_contract_specifiers (fndecl);
2256 26 : gcc_checking_assert (!contract_any_deferred_p (contract_spec));
2257 :
2258 26 : int flags = SF_DEFAULT | SF_PRE_PARSED;
2259 :
2260 26 : if (pre && !DECL_INITIAL (pre))
2261 : {
2262 14 : DECL_PENDING_INLINE_P (pre) = false;
2263 14 : start_preparsed_function (pre, DECL_ATTRIBUTES (pre), flags);
2264 14 : remap_and_emit_conditions (fndecl, pre, PRECONDITION_STMT);
2265 14 : finish_return_stmt (NULL_TREE);
2266 14 : pre = finish_function (false);
2267 14 : expand_or_defer_fn (pre);
2268 : }
2269 :
2270 26 : if (post && !DECL_INITIAL (post))
2271 : {
2272 14 : DECL_PENDING_INLINE_P (post) = false;
2273 14 : start_preparsed_function (post, DECL_ATTRIBUTES (post), flags);
2274 14 : remap_and_emit_conditions (fndecl, post, POSTCONDITION_STMT);
2275 14 : gcc_checking_assert (VOID_TYPE_P (TREE_TYPE (TREE_TYPE (post))));
2276 14 : finish_return_stmt (NULL_TREE);
2277 14 : post = finish_function (false);
2278 14 : expand_or_defer_fn (post);
2279 : }
2280 : }
2281 :
2282 : /* ===== Code generation ===== */
2283 :
2284 : /* Insert a BUILT_IN_OBSERVABLE_CHECKPOINT epoch marker. */
2285 :
2286 : static void
2287 534 : emit_builtin_observable_checkpoint ()
2288 : {
2289 534 : tree fn = builtin_decl_explicit (BUILT_IN_OBSERVABLE_CHKPT);
2290 534 : releasing_vec vec;
2291 534 : fn = finish_call_expr (fn, &vec, false, false, tf_warning_or_error);
2292 534 : finish_expr_stmt (fn);
2293 534 : }
2294 :
2295 : /* Shared code between TU-local wrappers for the violation handler. */
2296 :
2297 : static tree
2298 380 : declare_one_violation_handler_wrapper (tree fn_name, tree fn_type,
2299 : tree p1_type, tree p2_type)
2300 : {
2301 380 : location_t loc = BUILTINS_LOCATION;
2302 380 : tree fn_decl = build_lang_decl_loc (loc, FUNCTION_DECL, fn_name, fn_type);
2303 380 : DECL_CONTEXT (fn_decl) = FROB_CONTEXT (global_namespace);
2304 380 : DECL_ARTIFICIAL (fn_decl) = true;
2305 380 : DECL_INITIAL (fn_decl) = error_mark_node;
2306 : /* Let the start function code fill in the result decl. */
2307 380 : DECL_RESULT (fn_decl) = NULL_TREE;
2308 : /* Two args violation ref, dynamic info. */
2309 380 : tree parms = cp_build_parm_decl (fn_decl, NULL_TREE, p1_type);
2310 380 : TREE_USED (parms) = true;
2311 380 : DECL_READ_P (parms) = true;
2312 380 : tree p2 = cp_build_parm_decl (fn_decl, NULL_TREE, p2_type);
2313 380 : TREE_USED (p2) = true;
2314 380 : DECL_READ_P (p2) = true;
2315 380 : DECL_CHAIN (parms) = p2;
2316 380 : DECL_ARGUMENTS (fn_decl) = parms;
2317 : /* Make this function internal. */
2318 380 : TREE_PUBLIC (fn_decl) = false;
2319 380 : DECL_EXTERNAL (fn_decl) = false;
2320 380 : DECL_WEAK (fn_decl) = false;
2321 380 : return fn_decl;
2322 : }
2323 :
2324 : static GTY(()) tree tu_has_violation = NULL_TREE;
2325 : static GTY(()) tree tu_has_violation_exception = NULL_TREE;
2326 :
2327 : static void
2328 1036 : declare_violation_handler_wrappers ()
2329 : {
2330 1036 : if (tu_has_violation && tu_has_violation_exception)
2331 1036 : return;
2332 :
2333 190 : iloc_sentinel ils (input_location);
2334 190 : input_location = BUILTINS_LOCATION;
2335 190 : tree v_obj_type = builtin_contract_violation_type;
2336 190 : v_obj_type = cp_build_qualified_type (v_obj_type, TYPE_QUAL_CONST);
2337 190 : v_obj_type = cp_build_reference_type (v_obj_type, /*rval*/false);
2338 190 : tree fn_type = build_function_type_list (void_type_node, v_obj_type,
2339 : uint16_type_node, NULL_TREE);
2340 190 : tree fn_name = get_identifier ("__tu_has_violation_exception");
2341 190 : tu_has_violation_exception
2342 190 : = declare_one_violation_handler_wrapper (fn_name, fn_type, v_obj_type,
2343 : uint16_type_node);
2344 190 : fn_name = get_identifier ("__tu_has_violation");
2345 190 : tu_has_violation
2346 190 : = declare_one_violation_handler_wrapper (fn_name, fn_type, v_obj_type,
2347 : uint16_type_node);
2348 190 : }
2349 :
2350 : static GTY(()) tree tu_terminate_wrapper = NULL_TREE;
2351 :
2352 : /* Declare a noipa wrapper around the call to std::terminate */
2353 :
2354 : static tree
2355 1038 : declare_terminate_wrapper ()
2356 : {
2357 1038 : if (tu_terminate_wrapper)
2358 : return tu_terminate_wrapper;
2359 :
2360 192 : iloc_sentinel ils (input_location);
2361 192 : input_location = BUILTINS_LOCATION;
2362 :
2363 192 : tree fn_type = build_function_type_list (void_type_node, NULL_TREE);
2364 192 : if (!TREE_NOTHROW (terminate_fn))
2365 0 : fn_type = build_exception_variant (fn_type, noexcept_true_spec);
2366 192 : tree fn_name = get_identifier ("__tu_terminate_wrapper");
2367 :
2368 192 : tu_terminate_wrapper
2369 192 : = build_lang_decl_loc (input_location, FUNCTION_DECL, fn_name, fn_type);
2370 192 : DECL_CONTEXT (tu_terminate_wrapper) = FROB_CONTEXT(global_namespace);
2371 192 : DECL_ARTIFICIAL (tu_terminate_wrapper) = true;
2372 192 : DECL_INITIAL (tu_terminate_wrapper) = error_mark_node;
2373 : /* Let the start function code fill in the result decl. */
2374 192 : DECL_RESULT (tu_terminate_wrapper) = NULL_TREE;
2375 :
2376 : /* Make this function internal. */
2377 192 : TREE_PUBLIC (tu_terminate_wrapper) = false;
2378 192 : DECL_EXTERNAL (tu_terminate_wrapper) = false;
2379 192 : DECL_WEAK (tu_terminate_wrapper) = false;
2380 :
2381 192 : DECL_ATTRIBUTES (tu_terminate_wrapper)
2382 192 : = tree_cons (get_identifier ("noipa"), NULL, NULL_TREE);
2383 192 : cplus_decl_attributes (&tu_terminate_wrapper,
2384 192 : DECL_ATTRIBUTES (tu_terminate_wrapper), 0);
2385 192 : return tu_terminate_wrapper;
2386 192 : }
2387 :
2388 : /* Define a noipa wrapper around the call to std::terminate */
2389 :
2390 : static void
2391 192 : build_terminate_wrapper ()
2392 : {
2393 : /* We should not be trying to build this if we never used it. */
2394 192 : gcc_checking_assert (tu_terminate_wrapper);
2395 :
2396 192 : start_preparsed_function (tu_terminate_wrapper,
2397 192 : DECL_ATTRIBUTES(tu_terminate_wrapper),
2398 : SF_DEFAULT | SF_PRE_PARSED);
2399 192 : tree body = begin_function_body ();
2400 192 : tree compound_stmt = begin_compound_stmt (BCS_FN_BODY);
2401 192 : finish_expr_stmt (build_call_a (terminate_fn, 0, nullptr));
2402 192 : finish_return_stmt (NULL_TREE);
2403 192 : finish_compound_stmt (compound_stmt);
2404 192 : finish_function_body (body);
2405 192 : tu_terminate_wrapper = finish_function (false);
2406 192 : expand_or_defer_fn (tu_terminate_wrapper);
2407 192 : }
2408 :
2409 : /* Lookup a name in std::contracts, or inject it. */
2410 :
2411 : static tree
2412 148 : lookup_std_contracts_type (tree name_id)
2413 : {
2414 148 : tree id_ns = get_identifier ("contracts");
2415 148 : tree ns = lookup_qualified_name (std_node, id_ns);
2416 :
2417 148 : tree res_type = error_mark_node;
2418 148 : if (TREE_CODE (ns) == NAMESPACE_DECL)
2419 8 : res_type = lookup_qualified_name
2420 8 : (ns, name_id, LOOK_want::TYPE | LOOK_want::HIDDEN_FRIEND);
2421 :
2422 148 : if (TREE_CODE (res_type) == TYPE_DECL)
2423 8 : res_type = TREE_TYPE (res_type);
2424 : else
2425 : {
2426 140 : push_nested_namespace (std_node);
2427 140 : push_namespace (id_ns, /*inline*/false);
2428 140 : res_type = make_class_type (RECORD_TYPE);
2429 140 : create_implicit_typedef (name_id, res_type);
2430 140 : DECL_SOURCE_LOCATION (TYPE_NAME (res_type)) = BUILTINS_LOCATION;
2431 140 : DECL_CONTEXT (TYPE_NAME (res_type)) = current_namespace;
2432 140 : pushdecl_namespace_level (TYPE_NAME (res_type), /*hidden*/true);
2433 140 : pop_namespace ();
2434 140 : pop_nested_namespace (std_node);
2435 : }
2436 148 : return res_type;
2437 : }
2438 :
2439 : /* Return handle_contract_violation (), declaring it if needed. */
2440 :
2441 : static tree
2442 380 : declare_handle_contract_violation ()
2443 : {
2444 : /* We may need to declare new types, ensure they are not considered
2445 : attached to a named module. */
2446 380 : auto module_kind_override = make_temp_override
2447 380 : (module_kind, module_kind & ~(MK_PURVIEW | MK_ATTACH | MK_EXPORTING));
2448 380 : tree fnname = get_identifier ("handle_contract_violation");
2449 380 : tree viol_name = get_identifier ("contract_violation");
2450 380 : tree l = lookup_qualified_name (global_namespace, fnname,
2451 : LOOK_want::HIDDEN_FRIEND);
2452 908 : for (tree f: lkp_range (l))
2453 380 : if (TREE_CODE (f) == FUNCTION_DECL)
2454 : {
2455 232 : tree parms = TYPE_ARG_TYPES (TREE_TYPE (f));
2456 232 : if (remaining_arguments (parms) != 1)
2457 0 : continue;
2458 232 : tree parmtype = non_reference (TREE_VALUE (parms));
2459 232 : if (CLASS_TYPE_P (parmtype)
2460 464 : && TYPE_IDENTIFIER (parmtype) == viol_name)
2461 232 : return f;
2462 : }
2463 :
2464 148 : tree violation = lookup_std_contracts_type (viol_name);
2465 148 : tree fntype = NULL_TREE;
2466 148 : tree v_obj_ref = cp_build_qualified_type (violation, TYPE_QUAL_CONST);
2467 148 : v_obj_ref = cp_build_reference_type (v_obj_ref, /*rval*/false);
2468 148 : fntype = build_function_type_list (void_type_node, v_obj_ref, NULL_TREE);
2469 :
2470 148 : push_nested_namespace (global_namespace);
2471 148 : tree fndecl
2472 148 : = build_cp_library_fn_ptr ("handle_contract_violation", fntype, ECF_COLD);
2473 148 : pushdecl_namespace_level (fndecl, /*hiding*/true);
2474 148 : pop_nested_namespace (global_namespace);
2475 :
2476 : /* Build the parameter(s). */
2477 148 : tree parms = cp_build_parm_decl (fndecl, NULL_TREE, v_obj_ref);
2478 148 : TREE_USED (parms) = true;
2479 148 : DECL_READ_P (parms) = true;
2480 148 : DECL_ARGUMENTS (fndecl) = parms;
2481 148 : return fndecl;
2482 380 : }
2483 :
2484 : /* Build the call to handle_contract_violation for VIOLATION. */
2485 :
2486 : static void
2487 380 : build_contract_handler_call (tree violation)
2488 : {
2489 380 : tree violation_fn = declare_handle_contract_violation ();
2490 380 : tree call = build_call_n (violation_fn, 1, violation);
2491 380 : finish_expr_stmt (call);
2492 380 : }
2493 :
2494 : /* If we have emitted any contracts in this TU that will call a violation
2495 : handler, then emit the wrappers for the handler. */
2496 :
2497 : void
2498 25139 : maybe_emit_violation_handler_wrappers ()
2499 : {
2500 : /* We might need the terminate wrapper, even if we do not use the violation
2501 : handler wrappers. */
2502 25139 : if (tu_terminate_wrapper && flag_contracts_conservative_ipa)
2503 192 : build_terminate_wrapper ();
2504 :
2505 25139 : if (!tu_has_violation && !tu_has_violation_exception)
2506 : return;
2507 :
2508 190 : tree terminate_wrapper = terminate_fn;
2509 190 : if (flag_contracts_conservative_ipa)
2510 190 : terminate_wrapper = tu_terminate_wrapper;
2511 :
2512 : /* tu_has_violation */
2513 190 : start_preparsed_function (tu_has_violation, NULL_TREE,
2514 : SF_DEFAULT | SF_PRE_PARSED);
2515 190 : tree body = begin_function_body ();
2516 190 : tree compound_stmt = begin_compound_stmt (BCS_FN_BODY);
2517 190 : tree v = DECL_ARGUMENTS (tu_has_violation);
2518 190 : tree semantic = DECL_CHAIN (v);
2519 :
2520 : /* We are going to call the handler. */
2521 190 : build_contract_handler_call (v);
2522 :
2523 190 : tree if_observe = begin_if_stmt ();
2524 : /* if (observe) return; */
2525 190 : tree cond = build2 (EQ_EXPR, uint16_type_node, semantic,
2526 : build_int_cst (uint16_type_node, (uint16_t)CES_OBSERVE));
2527 190 : finish_if_stmt_cond (cond, if_observe);
2528 190 : emit_builtin_observable_checkpoint ();
2529 190 : finish_then_clause (if_observe);
2530 190 : begin_else_clause (if_observe);
2531 : /* else terminate. */
2532 190 : finish_expr_stmt (build_call_a (terminate_wrapper, 0, nullptr));
2533 190 : finish_else_clause (if_observe);
2534 190 : finish_if_stmt (if_observe);
2535 190 : finish_return_stmt (NULL_TREE);
2536 :
2537 190 : finish_compound_stmt (compound_stmt);
2538 190 : finish_function_body (body);
2539 190 : tu_has_violation = finish_function (false);
2540 190 : expand_or_defer_fn (tu_has_violation);
2541 :
2542 : /* tu_has_violation_exception */
2543 190 : start_preparsed_function (tu_has_violation_exception, NULL_TREE,
2544 : SF_DEFAULT | SF_PRE_PARSED);
2545 190 : body = begin_function_body ();
2546 190 : compound_stmt = begin_compound_stmt (BCS_FN_BODY);
2547 190 : v = DECL_ARGUMENTS (tu_has_violation_exception);
2548 190 : semantic = DECL_CHAIN (v);
2549 190 : location_t loc = DECL_SOURCE_LOCATION (tu_has_violation_exception);
2550 :
2551 190 : tree a_type = strip_top_quals (non_reference (TREE_TYPE (v)));
2552 190 : tree v2 = build_decl (loc, VAR_DECL, NULL_TREE, a_type);
2553 190 : DECL_SOURCE_LOCATION (v2) = loc;
2554 190 : DECL_CONTEXT (v2) = current_function_decl;
2555 190 : DECL_ARTIFICIAL (v2) = true;
2556 190 : layout_decl (v2, 0);
2557 190 : v2 = pushdecl (v2);
2558 190 : add_decl_expr (v2);
2559 190 : tree r = cp_build_init_expr (v2, convert_from_reference (v));
2560 190 : finish_expr_stmt (r);
2561 190 : tree memb = lookup_member (a_type, get_identifier ("_M_detection_mode"),
2562 : /*protect=*/1, /*want_type=*/0, tf_warning_or_error);
2563 190 : r = build_class_member_access_expr (v2, memb, NULL_TREE, false,
2564 : tf_warning_or_error);
2565 190 : r = cp_build_modify_expr
2566 190 : (loc, r, NOP_EXPR,
2567 : build_int_cst (uint16_type_node, (uint16_t)CDM_EVAL_EXCEPTION),
2568 : tf_warning_or_error);
2569 190 : finish_expr_stmt (r);
2570 : /* We are going to call the handler. */
2571 190 : build_contract_handler_call (v);
2572 :
2573 190 : if_observe = begin_if_stmt ();
2574 : /* if (observe) return; */
2575 190 : cond = build2 (EQ_EXPR, uint16_type_node, semantic,
2576 : build_int_cst (uint16_type_node, (uint16_t)CES_OBSERVE));
2577 190 : finish_if_stmt_cond (cond, if_observe);
2578 190 : emit_builtin_observable_checkpoint ();
2579 190 : finish_then_clause (if_observe);
2580 190 : begin_else_clause (if_observe);
2581 : /* else terminate. */
2582 190 : finish_expr_stmt (build_call_a (terminate_wrapper, 0, nullptr));
2583 190 : finish_else_clause (if_observe);
2584 190 : finish_if_stmt (if_observe);
2585 190 : finish_return_stmt (NULL_TREE);
2586 190 : finish_compound_stmt (compound_stmt);
2587 190 : finish_function_body (body);
2588 190 : tu_has_violation_exception = finish_function (false);
2589 190 : expand_or_defer_fn (tu_has_violation_exception);
2590 : }
2591 :
2592 : /* Build a layout-compatible internal version of contract_violation type. */
2593 :
2594 : static tree
2595 25461 : get_contract_violation_fields ()
2596 : {
2597 25461 : tree fields = NULL_TREE;
2598 : /* Must match <contracts>:
2599 : class contract_violation {
2600 : uint16_t _M_version;
2601 : assertion_kind _M_assertion_kind;
2602 : evaluation_semantic _M_evaluation_semantic;
2603 : detection_mode _M_detection_mode;
2604 : const char* _M_comment;
2605 : void *_M_src_loc_ptr;
2606 : __vendor_ext* _M_ext;
2607 : };
2608 : If this changes, also update the initializer in
2609 : build_contract_violation. */
2610 25461 : const tree types[] = { uint16_type_node,
2611 : uint16_type_node,
2612 : uint16_type_node,
2613 : uint16_type_node,
2614 25461 : const_string_type_node,
2615 25461 : ptr_type_node,
2616 : ptr_type_node
2617 25461 : };
2618 25461 : const char *names[] = { "_M_version",
2619 : "_M_assertion_kind",
2620 : "_M_evaluation_semantic",
2621 : "_M_detection_mode",
2622 : "_M_comment",
2623 : "_M_src_loc_ptr",
2624 : "_M_ext",
2625 : };
2626 25461 : unsigned n = 0;
2627 203688 : for (tree type : types)
2628 : {
2629 : /* finish_builtin_struct wants fields chained in reverse. */
2630 178227 : tree next = build_decl (BUILTINS_LOCATION, FIELD_DECL,
2631 178227 : get_identifier(names[n++]), type);
2632 178227 : DECL_CHAIN (next) = fields;
2633 178227 : fields = next;
2634 : }
2635 25461 : return fields;
2636 : }
2637 :
2638 : /* Build a type to represent contract violation objects. */
2639 :
2640 : static tree
2641 25461 : init_builtin_contract_violation_type ()
2642 : {
2643 25461 : if (builtin_contract_violation_type)
2644 : return builtin_contract_violation_type;
2645 :
2646 25461 : tree fields = get_contract_violation_fields ();
2647 :
2648 25461 : iloc_sentinel ils (input_location);
2649 25461 : input_location = BUILTINS_LOCATION;
2650 25461 : builtin_contract_violation_type = make_class_type (RECORD_TYPE);
2651 25461 : finish_builtin_struct (builtin_contract_violation_type,
2652 : "__builtin_contract_violation_type", fields, NULL_TREE);
2653 50922 : CLASSTYPE_AS_BASE (builtin_contract_violation_type)
2654 25461 : = builtin_contract_violation_type;
2655 25461 : DECL_CONTEXT (TYPE_NAME (builtin_contract_violation_type))
2656 25461 : = FROB_CONTEXT (global_namespace);
2657 25461 : CLASSTYPE_LITERAL_P (builtin_contract_violation_type) = true;
2658 25461 : CLASSTYPE_LAZY_COPY_CTOR (builtin_contract_violation_type) = true;
2659 25461 : xref_basetypes (builtin_contract_violation_type, /*bases=*/NULL_TREE);
2660 25461 : DECL_CONTEXT (TYPE_NAME (builtin_contract_violation_type))
2661 25461 : = FROB_CONTEXT (global_namespace);
2662 25461 : DECL_ARTIFICIAL (TYPE_NAME (builtin_contract_violation_type)) = true;
2663 25461 : TYPE_ARTIFICIAL (builtin_contract_violation_type) = true;
2664 25461 : builtin_contract_violation_type
2665 25461 : = cp_build_qualified_type (builtin_contract_violation_type,
2666 : TYPE_QUAL_CONST);
2667 25461 : return builtin_contract_violation_type;
2668 25461 : }
2669 :
2670 : /* Early initialisation of types and functions we will use. */
2671 : void
2672 25461 : init_contracts ()
2673 : {
2674 25461 : init_terminate_fn ();
2675 25461 : init_builtin_contract_violation_type ();
2676 25461 : }
2677 :
2678 : static GTY(()) tree contracts_source_location_impl_type;
2679 :
2680 : /* Build a layout-compatible internal version of source location __impl
2681 : type. */
2682 :
2683 : static tree
2684 190 : get_contracts_source_location_impl_type (tree context = NULL_TREE)
2685 : {
2686 190 : if (contracts_source_location_impl_type)
2687 : return contracts_source_location_impl_type;
2688 :
2689 : /* First see if we have a declaration that we can use. */
2690 190 : tree contracts_source_location_type
2691 190 : = lookup_std_type (get_identifier ("source_location"));
2692 :
2693 190 : if (contracts_source_location_type
2694 190 : && contracts_source_location_type != error_mark_node
2695 380 : && TYPE_FIELDS (contracts_source_location_type))
2696 : {
2697 49 : contracts_source_location_impl_type = get_source_location_impl_type ();
2698 49 : return contracts_source_location_impl_type;
2699 : }
2700 :
2701 : /* We do not, so build the __impl layout equivalent type, which must
2702 : match <source_location>:
2703 : struct __impl
2704 : {
2705 : const char* _M_file_name;
2706 : const char* _M_function_name;
2707 : unsigned _M_line;
2708 : unsigned _M_column;
2709 : }; */
2710 141 : const tree types[] = { const_string_type_node,
2711 : const_string_type_node,
2712 141 : uint_least32_type_node,
2713 141 : uint_least32_type_node };
2714 :
2715 141 : const char *names[] = { "_M_file_name",
2716 : "_M_function_name",
2717 : "_M_line",
2718 : "_M_column",
2719 : };
2720 141 : tree fields = NULL_TREE;
2721 141 : unsigned n = 0;
2722 705 : for (tree type : types)
2723 : {
2724 : /* finish_builtin_struct wants fields chained in reverse. */
2725 564 : tree next = build_decl (BUILTINS_LOCATION, FIELD_DECL,
2726 564 : get_identifier (names[n++]), type);
2727 564 : DECL_CHAIN (next) = fields;
2728 564 : fields = next;
2729 : }
2730 :
2731 141 : iloc_sentinel ils (input_location);
2732 141 : input_location = BUILTINS_LOCATION;
2733 141 : contracts_source_location_impl_type = cxx_make_type (RECORD_TYPE);
2734 141 : finish_builtin_struct (contracts_source_location_impl_type,
2735 : "__impl", fields, NULL_TREE);
2736 141 : DECL_CONTEXT (TYPE_NAME (contracts_source_location_impl_type)) = context;
2737 141 : DECL_ARTIFICIAL (TYPE_NAME (contracts_source_location_impl_type)) = true;
2738 141 : TYPE_ARTIFICIAL (contracts_source_location_impl_type) = true;
2739 141 : contracts_source_location_impl_type
2740 141 : = cp_build_qualified_type (contracts_source_location_impl_type,
2741 : TYPE_QUAL_CONST);
2742 :
2743 141 : return contracts_source_location_impl_type;
2744 141 : }
2745 :
2746 : static tree
2747 1036 : get_src_loc_impl_ptr (location_t loc)
2748 : {
2749 1036 : if (!contracts_source_location_impl_type)
2750 190 : get_contracts_source_location_impl_type ();
2751 :
2752 1036 : tree fndecl = current_function_decl;
2753 : /* We might be an outlined function. */
2754 1036 : if (DECL_IS_PRE_FN_P (fndecl) || DECL_IS_POST_FN_P (fndecl))
2755 32 : fndecl = get_orig_for_outlined (fndecl);
2756 : /* We might be a wrapper. */
2757 1036 : if (DECL_IS_WRAPPER_FN_P (fndecl))
2758 40 : fndecl = get_orig_func_for_wrapper (fndecl);
2759 :
2760 1036 : gcc_checking_assert (fndecl);
2761 1036 : tree impl__
2762 1036 : = build_source_location_impl (loc, fndecl,
2763 : contracts_source_location_impl_type);
2764 1036 : tree p = build_pointer_type (contracts_source_location_impl_type);
2765 1036 : return build_fold_addr_expr_with_type_loc (loc, impl__, p);
2766 : }
2767 :
2768 : /* Build a contract_violation layout compatible object. */
2769 :
2770 : /* Constructor. At present, this should always be constant. */
2771 :
2772 : static tree
2773 1036 : build_contract_violation_ctor (tree contract)
2774 : {
2775 1036 : bool can_be_const = true;
2776 1036 : uint16_t version = 1;
2777 : /* Default CDM_PREDICATE_FALSE. */
2778 1036 : uint16_t detection_mode = CDM_PREDICATE_FALSE;
2779 :
2780 1036 : tree assertion_kind = CONTRACT_ASSERTION_KIND (contract);
2781 1036 : if (!assertion_kind || really_constant_p (assertion_kind))
2782 : {
2783 1036 : contract_assertion_kind kind = get_contract_assertion_kind (contract);
2784 1036 : assertion_kind = build_int_cst (uint16_type_node, kind);
2785 : }
2786 : else
2787 : can_be_const = false;
2788 :
2789 1036 : tree eval_semantic = CONTRACT_EVALUATION_SEMANTIC (contract);
2790 1036 : gcc_checking_assert (eval_semantic);
2791 1036 : if (!really_constant_p (eval_semantic))
2792 0 : can_be_const = false;
2793 :
2794 1036 : tree comment = CONTRACT_COMMENT (contract);
2795 1036 : if (comment && !really_constant_p (comment))
2796 : can_be_const = false;
2797 :
2798 1036 : tree std_src_loc_impl_ptr = CONTRACT_STD_SOURCE_LOC (contract);
2799 1036 : if (std_src_loc_impl_ptr)
2800 : {
2801 0 : std_src_loc_impl_ptr = convert_from_reference (std_src_loc_impl_ptr);
2802 0 : if (!really_constant_p (std_src_loc_impl_ptr))
2803 0 : can_be_const = false;
2804 : }
2805 : else
2806 1036 : std_src_loc_impl_ptr = get_src_loc_impl_ptr (EXPR_LOCATION (contract));
2807 :
2808 : /* Must match the type layout in builtin_contract_violation_type. */
2809 1036 : tree f0 = next_aggregate_field (TYPE_FIELDS (builtin_contract_violation_type));
2810 1036 : tree f1 = next_aggregate_field (DECL_CHAIN (f0));
2811 1036 : tree f2 = next_aggregate_field (DECL_CHAIN (f1));
2812 1036 : tree f3 = next_aggregate_field (DECL_CHAIN (f2));
2813 1036 : tree f4 = next_aggregate_field (DECL_CHAIN (f3));
2814 1036 : tree f5 = next_aggregate_field (DECL_CHAIN (f4));
2815 1036 : tree f6 = next_aggregate_field (DECL_CHAIN (f5));
2816 1036 : tree ctor = build_constructor_va
2817 1036 : (builtin_contract_violation_type, 7,
2818 1036 : f0, build_int_cst (uint16_type_node, version),
2819 : f1, assertion_kind,
2820 : f2, eval_semantic,
2821 1036 : f3, build_int_cst (uint16_type_node, detection_mode),
2822 : f4, comment,
2823 : f5, std_src_loc_impl_ptr,
2824 : f6, build_zero_cst (nullptr_type_node)); // __vendor_ext
2825 :
2826 1036 : TREE_READONLY (ctor) = true;
2827 1036 : if (can_be_const)
2828 1036 : TREE_CONSTANT (ctor) = true;
2829 :
2830 1036 : return ctor;
2831 : }
2832 :
2833 : /* Build a named TU-local constant of TYPE. */
2834 :
2835 : static tree
2836 1036 : contracts_tu_local_named_var (location_t loc, const char *name, tree type)
2837 : {
2838 1036 : tree var_ = build_decl (loc, VAR_DECL, NULL, type);
2839 1036 : DECL_NAME (var_) = generate_internal_label (name);
2840 1036 : TREE_PUBLIC (var_) = false;
2841 1036 : DECL_EXTERNAL (var_) = false;
2842 1036 : TREE_STATIC (var_) = true;
2843 : /* Compiler-generated. */
2844 1036 : DECL_ARTIFICIAL (var_) = true;
2845 1036 : TREE_CONSTANT (var_) = true;
2846 1036 : layout_decl (var_, 0);
2847 1036 : return var_;
2848 : }
2849 :
2850 : /* Create a read-only violation object. */
2851 :
2852 : static tree
2853 1036 : build_contract_violation_constant (tree ctor, tree contract)
2854 : {
2855 1036 : tree viol_ = contracts_tu_local_named_var
2856 1036 : (EXPR_LOCATION (contract), "Lcontract_violation",
2857 : builtin_contract_violation_type);
2858 :
2859 1036 : TREE_CONSTANT (viol_) = true;
2860 1036 : DECL_INITIAL (viol_) = ctor;
2861 1036 : varpool_node::finalize_decl (viol_);
2862 :
2863 1036 : return viol_;
2864 : }
2865 :
2866 : /* Helper to replace references to dummy this parameters with references to
2867 : the first argument of the FUNCTION_DECL DATA. */
2868 :
2869 : static tree
2870 5112 : remap_dummy_this_1 (tree *tp, int *, void *data)
2871 : {
2872 5112 : if (!is_this_parameter (*tp))
2873 : return NULL_TREE;
2874 49 : tree fn = (tree)data;
2875 49 : *tp = DECL_ARGUMENTS (fn);
2876 49 : return NULL_TREE;
2877 : }
2878 :
2879 : /* Replace all references to dummy this parameters in EXPR with references to
2880 : the first argument of the FUNCTION_DECL FNDECL. */
2881 :
2882 : static void
2883 1038 : remap_dummy_this (tree fndecl, tree *expr)
2884 : {
2885 0 : walk_tree (expr, remap_dummy_this_1, fndecl, NULL);
2886 0 : }
2887 :
2888 : /* Replace uses of user's placeholder var with the actual return value. */
2889 :
2890 : struct replace_tree
2891 : {
2892 : tree from, to;
2893 : };
2894 :
2895 : static tree
2896 1793 : remap_retval_1 (tree *here, int *do_subtree, void *d)
2897 : {
2898 1793 : replace_tree *data = (replace_tree *) d;
2899 :
2900 1793 : if (*here == data->from)
2901 : {
2902 84 : *here = data->to;
2903 84 : *do_subtree = 0;
2904 : }
2905 : else
2906 1709 : *do_subtree = 1;
2907 1793 : return NULL_TREE;
2908 : }
2909 :
2910 : static void
2911 355 : remap_retval (tree fndecl, tree contract)
2912 : {
2913 355 : struct replace_tree data;
2914 355 : data.from = POSTCONDITION_IDENTIFIER (contract);
2915 355 : gcc_checking_assert (DECL_RESULT (fndecl));
2916 355 : data.to = DECL_RESULT (fndecl);
2917 355 : walk_tree (&CONTRACT_CONDITION (contract), remap_retval_1, &data, NULL);
2918 355 : }
2919 :
2920 :
2921 : /* Genericize a CONTRACT tree, but do not attach it to the current context,
2922 : the caller is responsible for that.
2923 : This is called during genericization. */
2924 :
2925 : tree
2926 1040 : build_contract_check (tree contract)
2927 : {
2928 1040 : contract_evaluation_semantic semantic = get_evaluation_semantic (contract);
2929 1040 : bool quick = false;
2930 1040 : bool calls_handler = false;
2931 1040 : switch (semantic)
2932 : {
2933 2 : case CES_IGNORE:
2934 2 : return void_node;
2935 : case CES_ENFORCE:
2936 : case CES_OBSERVE:
2937 : calls_handler = true;
2938 : break;
2939 2 : case CES_QUICK:
2940 2 : quick = true;
2941 2 : break;
2942 0 : default:
2943 0 : gcc_unreachable ();
2944 : }
2945 :
2946 1038 : location_t loc = EXPR_LOCATION (contract);
2947 :
2948 1038 : remap_dummy_this (current_function_decl, &CONTRACT_CONDITION (contract));
2949 1038 : tree condition = CONTRACT_CONDITION (contract);
2950 1038 : if (condition == error_mark_node)
2951 : return NULL_TREE;
2952 :
2953 1038 : if (!flag_contract_checks_outlined && POSTCONDITION_P (contract))
2954 : {
2955 355 : remap_retval (current_function_decl, contract);
2956 355 : condition = CONTRACT_CONDITION (contract);
2957 355 : if (condition == error_mark_node)
2958 : return NULL_TREE;
2959 : }
2960 :
2961 1038 : tree terminate_wrapper = terminate_fn;
2962 1038 : if (flag_contracts_conservative_ipa)
2963 1038 : terminate_wrapper = declare_terminate_wrapper ();
2964 1038 : if (calls_handler)
2965 1036 : declare_violation_handler_wrappers ();
2966 :
2967 1038 : bool check_might_throw = (flag_exceptions
2968 1038 : && !expr_noexcept_p (condition, tf_none));
2969 :
2970 : /* Build a statement expression to hold a contract check, with the check
2971 : potentially wrapped in a try-catch expr. */
2972 1038 : tree cc_bind = build3 (BIND_EXPR, void_type_node, NULL, NULL, NULL);
2973 1038 : BIND_EXPR_BODY (cc_bind) = push_stmt_list ();
2974 :
2975 1038 : if (TREE_CODE (contract) == ASSERTION_STMT)
2976 154 : emit_builtin_observable_checkpoint ();
2977 1038 : tree cond = build_x_unary_op (loc, TRUTH_NOT_EXPR, condition, NULL_TREE,
2978 : tf_warning_or_error);
2979 1038 : tree violation;
2980 1038 : bool viol_is_var = false;
2981 1038 : if (quick)
2982 : /* We will not be calling a handler. */
2983 2 : violation = build_zero_cst (nullptr_type_node);
2984 : else
2985 : {
2986 : /* Build a violation object, with the contract settings. */
2987 1036 : tree ctor = build_contract_violation_ctor (contract);
2988 1036 : gcc_checking_assert (TREE_CONSTANT (ctor));
2989 1036 : violation = build_contract_violation_constant (ctor, contract);
2990 1036 : violation = build_address (violation);
2991 : }
2992 :
2993 1038 : tree s_const = build_int_cst (uint16_type_node, semantic);
2994 : /* So now do we need a try-catch? */
2995 1038 : if (check_might_throw)
2996 : {
2997 : /* This will hold the computed condition. */
2998 193 : tree check_failed = build_decl (loc, VAR_DECL, NULL, boolean_type_node);
2999 193 : DECL_ARTIFICIAL (check_failed) = true;
3000 193 : DECL_IGNORED_P (check_failed) = true;
3001 193 : DECL_CONTEXT (check_failed) = current_function_decl;
3002 193 : layout_decl (check_failed, 0);
3003 193 : add_decl_expr (check_failed);
3004 193 : DECL_CHAIN (check_failed) = BIND_EXPR_VARS (cc_bind);
3005 193 : BIND_EXPR_VARS (cc_bind) = check_failed;
3006 193 : tree check_try = begin_try_block ();
3007 193 : finish_expr_stmt (cp_build_init_expr (check_failed, cond));
3008 193 : finish_try_block (check_try);
3009 :
3010 193 : tree handler = begin_handler ();
3011 193 : finish_handler_parms (NULL_TREE, handler); /* catch (...) */
3012 193 : if (quick)
3013 0 : finish_expr_stmt (build_call_a (terminate_wrapper, 0, nullptr));
3014 : else
3015 : {
3016 193 : if (viol_is_var)
3017 : {
3018 : /* We can update the detection mode here. */
3019 : tree memb
3020 : = lookup_member (builtin_contract_violation_type,
3021 : get_identifier ("_M_detection_mode"),
3022 : 1, 0, tf_warning_or_error);
3023 : tree r = cp_build_indirect_ref (loc, violation, RO_UNARY_STAR,
3024 : tf_warning_or_error);
3025 : r = build_class_member_access_expr (r, memb, NULL_TREE, false,
3026 : tf_warning_or_error);
3027 : r = cp_build_modify_expr
3028 : (loc, r, NOP_EXPR,
3029 : build_int_cst (uint16_type_node, (uint16_t)CDM_EVAL_EXCEPTION),
3030 : tf_warning_or_error);
3031 : finish_expr_stmt (r);
3032 : finish_expr_stmt (build_call_n (tu_has_violation, 2,
3033 : violation, s_const));
3034 : }
3035 : else
3036 : /* We need to make a copy of the violation object to update. */
3037 193 : finish_expr_stmt (build_call_n (tu_has_violation_exception, 2,
3038 : violation, s_const));
3039 : /* If we reach here, we have handled the exception thrown and do not
3040 : need further action. */
3041 193 : tree e = cp_build_modify_expr (loc, check_failed, NOP_EXPR,
3042 : boolean_false_node,
3043 : tf_warning_or_error);
3044 193 : finish_expr_stmt (e);
3045 : }
3046 193 : finish_handler (handler);
3047 193 : finish_handler_sequence (check_try);
3048 193 : cond = check_failed;
3049 193 : BIND_EXPR_VARS (cc_bind) = nreverse (BIND_EXPR_VARS (cc_bind));
3050 : }
3051 :
3052 1038 : tree do_check = begin_if_stmt ();
3053 1038 : finish_if_stmt_cond (cond, do_check);
3054 1038 : if (quick)
3055 2 : finish_expr_stmt (build_call_a (terminate_wrapper, 0, nullptr));
3056 : else
3057 1036 : finish_expr_stmt (build_call_n (tu_has_violation, 2, violation, s_const));
3058 1038 : finish_then_clause (do_check);
3059 1038 : finish_if_stmt (do_check);
3060 :
3061 1038 : TREE_SIDE_EFFECTS (cc_bind) = true;
3062 1038 : BIND_EXPR_BODY (cc_bind) = pop_stmt_list (BIND_EXPR_BODY (cc_bind));
3063 1038 : return cc_bind;
3064 : }
3065 :
3066 : #include "gt-cp-contracts.h"
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