Line data Source code
1 : /* Pass to detect and issue warnings for invalid accesses, including
2 : invalid or mismatched allocation/deallocation calls.
3 :
4 : Copyright (C) 2020-2026 Free Software Foundation, Inc.
5 : Contributed by Martin Sebor <msebor@redhat.com>.
6 :
7 : This file is part of GCC.
8 :
9 : GCC is free software; you can redistribute it and/or modify it under
10 : the terms of the GNU General Public License as published by the Free
11 : Software Foundation; either version 3, or (at your option) any later
12 : version.
13 :
14 : GCC is distributed in the hope that it will be useful, but WITHOUT ANY
15 : WARRANTY; without even the implied warranty of MERCHANTABILITY or
16 : FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 : for more details.
18 :
19 : You should have received a copy of the GNU General Public License
20 : along with GCC; see the file COPYING3. If not see
21 : <http://www.gnu.org/licenses/>. */
22 :
23 : #define INCLUDE_STRING
24 : #include "config.h"
25 : #include "system.h"
26 : #include "coretypes.h"
27 : #include "backend.h"
28 : #include "tree.h"
29 : #include "gimple.h"
30 : #include "tree-pass.h"
31 : #include "builtins.h"
32 : #include "diagnostic.h"
33 : #include "ssa.h"
34 : #include "gimple-pretty-print.h"
35 : #include "gimple-ssa-warn-access.h"
36 : #include "gimple-ssa-warn-restrict.h"
37 : #include "diagnostic-core.h"
38 : #include "fold-const.h"
39 : #include "gimple-iterator.h"
40 : #include "gimple-fold.h"
41 : #include "langhooks.h"
42 : #include "memmodel.h"
43 : #include "target.h"
44 : #include "tree-dfa.h"
45 : #include "tree-ssa.h"
46 : #include "tree-cfg.h"
47 : #include "tree-object-size.h"
48 : #include "tree-ssa-strlen.h"
49 : #include "calls.h"
50 : #include "cfganal.h"
51 : #include "intl.h"
52 : #include "gimple-range.h"
53 : #include "stringpool.h"
54 : #include "attribs.h"
55 : #include "demangle.h"
56 : #include "attr-fnspec.h"
57 : #include "pointer-query.h"
58 : #include "pretty-print-markup.h"
59 : #include "gcc-urlifier.h"
60 : #include "diagnostic-context-rich-location.h"
61 :
62 : /* Return true if tree node X has an associated location. */
63 :
64 : static inline location_t
65 117 : has_location (const_tree x)
66 : {
67 117 : if (DECL_P (x))
68 92 : return DECL_SOURCE_LOCATION (x) != UNKNOWN_LOCATION;
69 :
70 25 : if (EXPR_P (x))
71 0 : return EXPR_HAS_LOCATION (x);
72 :
73 : return false;
74 : }
75 :
76 : /* Return the associated location of STMT. */
77 :
78 : static inline location_t
79 2044106 : get_location (const gimple *stmt)
80 : {
81 1864723 : return gimple_location (stmt);
82 : }
83 :
84 : /* Return the associated location of tree node X. */
85 :
86 : static inline location_t
87 2047 : get_location (tree x)
88 : {
89 2047 : if (DECL_P (x))
90 981 : return DECL_SOURCE_LOCATION (x);
91 :
92 1066 : if (EXPR_P (x))
93 1066 : return EXPR_LOCATION (x);
94 :
95 : return UNKNOWN_LOCATION;
96 : }
97 :
98 : /* Overload of the nascent tree function for GIMPLE STMT. */
99 :
100 : static inline tree
101 1066692 : get_callee_fndecl (const gimple *stmt)
102 : {
103 623 : return gimple_call_fndecl (stmt);
104 : }
105 :
106 : static inline unsigned
107 27708782 : call_nargs (const gimple *stmt)
108 : {
109 2180319 : return gimple_call_num_args (stmt);
110 : }
111 :
112 : static inline unsigned
113 356 : call_nargs (const_tree expr)
114 : {
115 356 : return call_expr_nargs (expr);
116 : }
117 :
118 :
119 : static inline tree
120 10007957 : call_arg (const gimple *stmt, unsigned argno)
121 : {
122 1365552 : return gimple_call_arg (stmt, argno);
123 : }
124 :
125 : static inline tree
126 302 : call_arg (tree expr, unsigned argno)
127 : {
128 302 : return CALL_EXPR_ARG (expr, argno);
129 : }
130 :
131 : /* For a call EXPR at LOC to a function FNAME that expects a string
132 : in the argument ARG, issue a diagnostic due to it being a called
133 : with an argument that is a character array with no terminating
134 : NUL. SIZE is the EXACT size of the array, and BNDRNG the number
135 : of characters in which the NUL is expected. Either EXPR or FNAME
136 : may be null but noth both. SIZE may be null when BNDRNG is null. */
137 :
138 : template <class GimpleOrTree>
139 : static void
140 8080 : warn_string_no_nul (location_t loc, GimpleOrTree expr, const char *fname,
141 : tree arg, tree decl, tree size, bool exact,
142 : const wide_int bndrng[2] /* = NULL */)
143 : {
144 8080 : const opt_code opt = OPT_Wstringop_overread;
145 1390 : if ((expr && warning_suppressed_p (expr, opt))
146 8884 : || warning_suppressed_p (arg, opt))
147 1139 : return;
148 :
149 6941 : loc = expansion_point_location_if_in_system_header (loc);
150 : bool warned;
151 :
152 : /* Format the bound range as a string to keep the number of messages
153 : from exploding. */
154 : char bndstr[80];
155 6941 : *bndstr = 0;
156 6941 : if (bndrng)
157 : {
158 144 : if (bndrng[0] == bndrng[1])
159 132 : sprintf (bndstr, "%llu", (unsigned long long) bndrng[0].to_uhwi ());
160 : else
161 12 : sprintf (bndstr, "[%llu, %llu]",
162 12 : (unsigned long long) bndrng[0].to_uhwi (),
163 12 : (unsigned long long) bndrng[1].to_uhwi ());
164 : }
165 :
166 6941 : auto_diagnostic_group d;
167 :
168 6941 : const tree maxobjsize = max_object_size ();
169 6941 : const wide_int maxsiz = wi::to_wide (maxobjsize);
170 6941 : if (expr)
171 : {
172 765 : tree func = get_callee_fndecl (expr);
173 765 : rich_location_with_details richloc (loc, expr);
174 :
175 765 : if (bndrng)
176 : {
177 144 : if (wi::ltu_p (maxsiz, bndrng[0]))
178 0 : warned = warning_at (&richloc, opt,
179 : "%qD specified bound %s exceeds "
180 : "maximum object size %E",
181 : func, bndstr, maxobjsize);
182 : else
183 : {
184 144 : bool maybe = wi::to_wide (size) == bndrng[0];
185 191 : warned = warning_at (&richloc, opt,
186 : exact
187 : ? G_("%qD specified bound %s exceeds "
188 : "the size %E of unterminated array")
189 : : (maybe
190 47 : ? G_("%qD specified bound %s may "
191 : "exceed the size of at most %E "
192 : "of unterminated array")
193 : : G_("%qD specified bound %s exceeds "
194 : "the size of at most %E "
195 : "of unterminated array")),
196 : func, bndstr, size);
197 : }
198 : }
199 : else
200 621 : warned = warning_at (&richloc, opt,
201 : "%qD argument missing terminating nul",
202 : func);
203 765 : }
204 : else
205 : {
206 6176 : if (bndrng)
207 : {
208 0 : if (wi::ltu_p (maxsiz, bndrng[0]))
209 0 : warned = warning_at (loc, opt,
210 : "%qs specified bound %s exceeds "
211 : "maximum object size %E",
212 : fname, bndstr, maxobjsize);
213 : else
214 : {
215 0 : bool maybe = wi::to_wide (size) == bndrng[0];
216 0 : warned = warning_at (loc, opt,
217 : exact
218 : ? G_("%qs specified bound %s exceeds "
219 : "the size %E of unterminated array")
220 : : (maybe
221 0 : ? G_("%qs specified bound %s may "
222 : "exceed the size of at most %E "
223 : "of unterminated array")
224 : : G_("%qs specified bound %s exceeds "
225 : "the size of at most %E "
226 : "of unterminated array")),
227 : fname, bndstr, size);
228 : }
229 : }
230 : else
231 6176 : warned = warning_at (loc, opt,
232 : "%qs argument missing terminating nul",
233 : fname);
234 : }
235 :
236 6941 : if (warned)
237 : {
238 521 : inform (get_location (decl),
239 : "referenced argument declared here");
240 521 : suppress_warning (arg, opt);
241 521 : if (expr)
242 441 : suppress_warning (expr, opt);
243 : }
244 6941 : }
245 :
246 : void
247 819 : warn_string_no_nul (location_t loc, gimple *stmt, const char *fname,
248 : tree arg, tree decl, tree size /* = NULL_TREE */,
249 : bool exact /* = false */,
250 : const wide_int bndrng[2] /* = NULL */)
251 : {
252 819 : return warn_string_no_nul<gimple *> (loc, stmt, fname,
253 819 : arg, decl, size, exact, bndrng);
254 : }
255 :
256 : void
257 7232 : warn_string_no_nul (location_t loc, tree expr, const char *fname,
258 : tree arg, tree decl, tree size /* = NULL_TREE */,
259 : bool exact /* = false */,
260 : const wide_int bndrng[2] /* = NULL */)
261 : {
262 7232 : return warn_string_no_nul<tree> (loc, expr, fname,
263 7232 : arg, decl, size, exact, bndrng);
264 : }
265 :
266 : /* If EXP refers to an unterminated constant character array return
267 : the declaration of the object of which the array is a member or
268 : element and if SIZE is not null, set *SIZE to the size of
269 : the unterminated array and set *EXACT if the size is exact or
270 : clear it otherwise. Otherwise return null. */
271 :
272 : tree
273 623614 : unterminated_array (tree exp, tree *size /* = NULL */, bool *exact /* = NULL */)
274 : {
275 : /* C_STRLEN will return NULL and set DECL in the info
276 : structure if EXP references a unterminated array. */
277 623614 : c_strlen_data lendata = { };
278 623614 : tree len = c_strlen (exp, 1, &lendata);
279 623614 : if (len || !lendata.minlen || !lendata.decl)
280 : return NULL_TREE;
281 :
282 1765 : if (!size)
283 : return lendata.decl;
284 :
285 1765 : len = lendata.minlen;
286 1765 : if (lendata.off)
287 : {
288 : /* Constant offsets are already accounted for in LENDATA.MINLEN,
289 : but not in a SSA_NAME + CST expression. */
290 1765 : if (TREE_CODE (lendata.off) == INTEGER_CST)
291 1386 : *exact = true;
292 379 : else if (TREE_CODE (lendata.off) == PLUS_EXPR
293 379 : && TREE_CODE (TREE_OPERAND (lendata.off, 1)) == INTEGER_CST)
294 : {
295 : /* Subtract the offset from the size of the array. */
296 113 : *exact = false;
297 113 : tree temp = TREE_OPERAND (lendata.off, 1);
298 113 : temp = fold_convert (ssizetype, temp);
299 113 : len = fold_build2 (MINUS_EXPR, ssizetype, len, temp);
300 : }
301 : else
302 266 : *exact = false;
303 : }
304 : else
305 0 : *exact = true;
306 :
307 1765 : *size = len;
308 1765 : return lendata.decl;
309 : }
310 :
311 : /* For a call EXPR (which may be null) that expects a string argument
312 : SRC as an argument, returns false if SRC is a character array with
313 : no terminating NUL. When nonnull, BOUND is the number of characters
314 : in which to expect the terminating NUL. When EXPR is nonnull also
315 : issues a warning. */
316 :
317 : template <class GimpleOrTree>
318 : static bool
319 617377 : check_nul_terminated_array (GimpleOrTree expr, tree src, tree bound)
320 : {
321 : /* The constant size of the array SRC points to. The actual size
322 : may be less of EXACT is true, but not more. */
323 : tree size;
324 : /* True if SRC involves a non-constant offset into the array. */
325 : bool exact;
326 : /* The unterminated constant array SRC points to. */
327 617377 : tree nonstr = unterminated_array (src, &size, &exact);
328 617377 : if (!nonstr)
329 : return true;
330 :
331 : /* NONSTR refers to the non-nul terminated constant array and SIZE
332 : is the constant size of the array in bytes. EXACT is true when
333 : SIZE is exact. */
334 :
335 4990 : wide_int bndrng[2];
336 998 : if (bound)
337 : {
338 357 : int_range_max r (TREE_TYPE (bound));
339 :
340 714 : get_range_query (cfun)->range_of_expr (r, bound);
341 :
342 357 : if (r.undefined_p () || r.varying_p ())
343 : return true;
344 :
345 356 : bndrng[0] = r.lower_bound ();
346 356 : bndrng[1] = r.upper_bound ();
347 :
348 356 : if (exact)
349 : {
350 206 : if (wi::leu_p (bndrng[0], wi::to_wide (size)))
351 : return true;
352 : }
353 150 : else if (wi::lt_p (bndrng[0], wi::to_wide (size), UNSIGNED))
354 : return true;
355 357 : }
356 :
357 788 : if (expr)
358 1059 : warn_string_no_nul (get_location (expr), expr, NULL, src, nonstr,
359 : size, exact, bound ? bndrng : NULL);
360 :
361 : return false;
362 2994 : }
363 :
364 : bool
365 322191 : check_nul_terminated_array (gimple *stmt, tree src, tree bound /* = NULL_TREE */)
366 : {
367 322191 : return check_nul_terminated_array<gimple *>(stmt, src, bound);
368 : }
369 :
370 : bool
371 282752 : check_nul_terminated_array (tree expr, tree src, tree bound /* = NULL_TREE */)
372 : {
373 282752 : return check_nul_terminated_array<tree>(expr, src, bound);
374 : }
375 :
376 : /* Warn about passing a non-string array/pointer to a built-in function
377 : that expects a nul-terminated string argument. Returns true if
378 : a warning has been issued.*/
379 :
380 : template <class GimpleOrTree>
381 : static bool
382 7214333 : maybe_warn_nonstring_arg (tree fndecl, GimpleOrTree exp)
383 : {
384 7214333 : if (!fndecl || !fndecl_built_in_p (fndecl, BUILT_IN_NORMAL))
385 : return false;
386 :
387 2192442 : if (!warn_stringop_overread
388 2192442 : || warning_suppressed_p (exp, OPT_Wstringop_overread))
389 11767 : return false;
390 :
391 : /* Avoid clearly invalid calls (more checking done below). */
392 2180675 : unsigned nargs = call_nargs (exp);
393 2180675 : if (!nargs)
394 : return false;
395 :
396 : /* The bound argument to a bounded string function like strncpy. */
397 1864369 : tree bound = NULL_TREE;
398 :
399 : /* The longest known or possible string argument to one of the comparison
400 : functions. If the length is less than the bound it is used instead.
401 : Since the length is only used for warning and not for code generation
402 : disable strict mode in the calls to get_range_strlen below. */
403 1864369 : tree maxlen = NULL_TREE;
404 :
405 : /* It's safe to call "bounded" string functions with a non-string
406 : argument since the functions provide an explicit bound for this
407 : purpose. The exception is strncat where the bound may refer to
408 : either the destination or the source. */
409 1864369 : int fncode = DECL_FUNCTION_CODE (fndecl);
410 1864369 : switch (fncode)
411 : {
412 : case BUILT_IN_STRCMP:
413 : case BUILT_IN_STRNCMP:
414 : case BUILT_IN_STRNCASECMP:
415 : {
416 : /* For these, if one argument refers to one or more of a set
417 : of string constants or arrays of known size, determine
418 : the range of their known or possible lengths and use it
419 : conservatively as the bound for the unbounded function,
420 : and to adjust the range of the bound of the bounded ones. */
421 392400 : for (unsigned argno = 0;
422 783878 : argno < MIN (nargs, 2)
423 783878 : && !(maxlen && TREE_CODE (maxlen) == INTEGER_CST); argno++)
424 : {
425 392400 : tree arg = call_arg (exp, argno);
426 392400 : if (!get_attr_nonstring_decl (arg))
427 : {
428 391460 : c_strlen_data lendata = { };
429 : /* Set MAXBOUND to an arbitrary non-null non-integer
430 : node as a request to have it set to the length of
431 : the longest string in a PHI. */
432 391460 : lendata.maxbound = arg;
433 391460 : get_range_strlen (arg, &lendata, /* eltsize = */ 1);
434 391460 : maxlen = lendata.maxbound;
435 : }
436 : }
437 : }
438 : /* Fall through. */
439 :
440 : case BUILT_IN_STRNCAT:
441 : case BUILT_IN_STPNCPY:
442 : case BUILT_IN_STRNCPY:
443 397469 : if (nargs > 2)
444 11366 : bound = call_arg (exp, 2);
445 : break;
446 :
447 722 : case BUILT_IN_STRNDUP:
448 722 : if (nargs < 2)
449 : return false;
450 722 : bound = call_arg (exp, 1);
451 722 : break;
452 :
453 1471 : case BUILT_IN_STRNLEN:
454 : {
455 1471 : tree arg = call_arg (exp, 0);
456 1471 : if (!get_attr_nonstring_decl (arg))
457 : {
458 1333 : c_strlen_data lendata = { };
459 : /* Set MAXBOUND to an arbitrary non-null non-integer
460 : node as a request to have it set to the length of
461 : the longest string in a PHI. */
462 1333 : lendata.maxbound = arg;
463 1333 : get_range_strlen (arg, &lendata, /* eltsize = */ 1);
464 1333 : maxlen = lendata.maxbound;
465 : }
466 1471 : if (nargs > 1)
467 1470 : bound = call_arg (exp, 1);
468 : break;
469 : }
470 :
471 : default:
472 : break;
473 : }
474 :
475 : /* Determine the range of the bound argument (if specified). */
476 1864369 : tree bndrng[2] = { NULL_TREE, NULL_TREE };
477 1864369 : if (bound)
478 : {
479 13558 : STRIP_NOPS (bound);
480 13558 : get_size_range (bound, bndrng);
481 : }
482 :
483 1864369 : location_t loc = get_location (exp);
484 :
485 1864369 : if (bndrng[0])
486 : {
487 : /* Diagnose excessive bound prior to the adjustment below and
488 : regardless of attribute nonstring. */
489 13538 : tree maxobjsize = max_object_size ();
490 13538 : if (tree_int_cst_lt (maxobjsize, bndrng[0]))
491 : {
492 131 : rich_location_with_details richloc (loc, exp);
493 :
494 131 : bool warned = false;
495 131 : if (tree_int_cst_equal (bndrng[0], bndrng[1]))
496 114 : warned = warning_at (&richloc, OPT_Wstringop_overread,
497 : "%qD specified bound %E "
498 : "exceeds maximum object size %E",
499 : fndecl, bndrng[0], maxobjsize);
500 : else
501 17 : warned = warning_at (&richloc, OPT_Wstringop_overread,
502 : "%qD specified bound [%E, %E] "
503 : "exceeds maximum object size %E",
504 : fndecl, bndrng[0], bndrng[1],
505 : maxobjsize);
506 131 : if (warned)
507 45 : suppress_warning (exp, OPT_Wstringop_overread);
508 :
509 : return warned;
510 131 : }
511 : }
512 :
513 1864238 : if (maxlen && !integer_all_onesp (maxlen))
514 : {
515 : /* Add one for the nul. */
516 6954 : maxlen = const_binop (PLUS_EXPR, TREE_TYPE (maxlen), maxlen,
517 : size_one_node);
518 :
519 6954 : if (!bndrng[0])
520 : {
521 : /* Conservatively use the upper bound of the lengths for
522 : both the lower and the upper bound of the operation. */
523 4592 : bndrng[0] = maxlen;
524 4592 : bndrng[1] = maxlen;
525 4592 : bound = void_type_node;
526 : }
527 2362 : else if (maxlen)
528 : {
529 : /* Replace the bound on the operation with the upper bound
530 : of the length of the string if the latter is smaller. */
531 2353 : if (tree_int_cst_lt (maxlen, bndrng[0]))
532 200 : bndrng[0] = maxlen;
533 2153 : else if (tree_int_cst_lt (maxlen, bndrng[1]))
534 527 : bndrng[1] = maxlen;
535 : }
536 : }
537 :
538 1864238 : bool any_arg_warned = false;
539 : /* Iterate over the built-in function's formal arguments and check
540 : each const char* against the actual argument. If the actual
541 : argument is declared attribute non-string issue a warning unless
542 : the argument's maximum length is bounded. */
543 : function_args_iterator it;
544 1864238 : function_args_iter_init (&it, TREE_TYPE (fndecl));
545 :
546 5906878 : for (unsigned argno = 0; ; ++argno, function_args_iter_next (&it))
547 : {
548 : /* Avoid iterating past the declared argument in a call
549 : to function declared without a prototype. */
550 5903924 : if (argno >= nargs)
551 : break;
552 :
553 4198712 : tree argtype = function_args_iter_cond (&it);
554 4198712 : if (!argtype)
555 : break;
556 :
557 4039686 : if (!POINTER_TYPE_P (argtype))
558 4036732 : continue;
559 :
560 2477915 : argtype = TREE_TYPE (argtype);
561 :
562 3971488 : if (TREE_CODE (argtype) != INTEGER_TYPE
563 2477915 : || !TYPE_READONLY (argtype))
564 1493573 : continue;
565 :
566 984342 : argtype = TYPE_MAIN_VARIANT (argtype);
567 984342 : if (argtype != char_type_node)
568 11376 : continue;
569 :
570 972966 : tree callarg = call_arg (exp, argno);
571 972966 : if (TREE_CODE (callarg) == ADDR_EXPR)
572 537906 : callarg = TREE_OPERAND (callarg, 0);
573 :
574 : /* See if the destination is declared with attribute "nonstring". */
575 972966 : tree decl = get_attr_nonstring_decl (callarg);
576 972966 : if (!decl)
577 970012 : continue;
578 :
579 : /* The maximum number of array elements accessed. */
580 2954 : offset_int wibnd = 0;
581 :
582 2954 : if (argno && fncode == BUILT_IN_STRNCAT)
583 : {
584 : /* See if the bound in strncat is derived from the length
585 : of the strlen of the destination (as it's expected to be).
586 : If so, reset BOUND and FNCODE to trigger a warning. */
587 488 : tree dstarg = call_arg (exp, 0);
588 488 : if (is_strlen_related_p (dstarg, bound))
589 : {
590 : /* The bound applies to the destination, not to the source,
591 : so reset these to trigger a warning without mentioning
592 : the bound. */
593 : bound = NULL;
594 : fncode = 0;
595 : }
596 480 : else if (bndrng[1])
597 : /* Use the upper bound of the range for strncat. */
598 480 : wibnd = wi::to_offset (bndrng[1]);
599 : }
600 2466 : else if (bndrng[0])
601 : /* Use the lower bound of the range for functions other than
602 : strncat. */
603 2010 : wibnd = wi::to_offset (bndrng[0]);
604 :
605 : /* Determine the size of the argument array if it is one. */
606 2954 : offset_int asize = wibnd;
607 2954 : bool known_size = false;
608 2954 : tree type = TREE_TYPE (decl);
609 :
610 2954 : while (TREE_CODE (type) == ARRAY_TYPE
611 4146 : && TREE_CODE (TREE_TYPE (type)) == ARRAY_TYPE)
612 1192 : type = TREE_TYPE (type);
613 :
614 : /* Determine the array size. For arrays of unknown bound and
615 : pointers reset BOUND to trigger the appropriate warning. */
616 2954 : if (TREE_CODE (type) == ARRAY_TYPE)
617 : {
618 2490 : if (tree arrbnd = TYPE_DOMAIN (type))
619 : {
620 2428 : if ((arrbnd = TYPE_MAX_VALUE (arrbnd))
621 2428 : && TREE_CODE (arrbnd) == INTEGER_CST)
622 : {
623 2426 : asize = wi::to_offset (arrbnd) + 1;
624 2426 : known_size = true;
625 : }
626 : }
627 62 : else if (bound == void_type_node)
628 2954 : bound = NULL_TREE;
629 : }
630 464 : else if (bound == void_type_node)
631 2954 : bound = NULL_TREE;
632 :
633 : /* In a call to strncat with a bound in a range whose lower but
634 : not upper bound is less than the array size, reset ASIZE to
635 : be the same as the bound and the other variable to trigger
636 : the appropriate warning below. */
637 : if (fncode == BUILT_IN_STRNCAT
638 480 : && bndrng[0] != bndrng[1]
639 3114 : && wi::ltu_p (wi::to_offset (bndrng[0]), asize)
640 3146 : && (!known_size
641 184 : || wi::ltu_p (asize, wibnd)))
642 : {
643 32 : asize = wibnd;
644 32 : bound = NULL_TREE;
645 32 : fncode = 0;
646 : }
647 :
648 2954 : bool warned = false;
649 :
650 2954 : auto_diagnostic_group d;
651 2954 : if (wi::ltu_p (asize, wibnd))
652 : {
653 369 : rich_location_with_details richloc (loc, exp);
654 369 : if (bndrng[0] == bndrng[1])
655 312 : warned = warning_at (&richloc, OPT_Wstringop_overread,
656 : "%qD argument %i declared attribute "
657 : "%<nonstring%> is smaller than the specified "
658 : "bound %wu",
659 : fndecl, argno + 1, wibnd.to_uhwi ());
660 57 : else if (wi::ltu_p (asize, wi::to_offset (bndrng[0])))
661 41 : warned = warning_at (&richloc, OPT_Wstringop_overread,
662 : "%qD argument %i declared attribute "
663 : "%<nonstring%> is smaller than "
664 : "the specified bound [%E, %E]",
665 : fndecl, argno + 1, bndrng[0], bndrng[1]);
666 : else
667 16 : warned = warning_at (&richloc, OPT_Wstringop_overread,
668 : "%qD argument %i declared attribute "
669 : "%<nonstring%> may be smaller than "
670 : "the specified bound [%E, %E]",
671 : fndecl, argno + 1, bndrng[0], bndrng[1]);
672 369 : }
673 2585 : else if (fncode == BUILT_IN_STRNCAT)
674 : ; /* Avoid warning for calls to strncat() when the bound
675 : is equal to the size of the non-string argument. */
676 2177 : else if (!bound)
677 528 : warned = warning_at (loc, OPT_Wstringop_overread,
678 : "%qD argument %i declared attribute %<nonstring%>",
679 : fndecl, argno + 1);
680 :
681 897 : if (warned)
682 : {
683 897 : inform (DECL_SOURCE_LOCATION (decl),
684 : "argument %qD declared here", decl);
685 897 : any_arg_warned = true;
686 : }
687 : }
688 :
689 1864238 : if (any_arg_warned)
690 897 : suppress_warning (exp, OPT_Wstringop_overread);
691 :
692 : return any_arg_warned;
693 : }
694 :
695 : bool
696 360332 : maybe_warn_nonstring_arg (tree fndecl, gimple *stmt)
697 : {
698 360332 : return maybe_warn_nonstring_arg<gimple *>(fndecl, stmt);
699 : }
700 :
701 :
702 : bool
703 356 : maybe_warn_nonstring_arg (tree fndecl, tree expr)
704 : {
705 356 : return maybe_warn_nonstring_arg<tree>(fndecl, expr);
706 : }
707 :
708 : /* Issue a warning OPT for a bounded call EXP with a bound in RANGE
709 : accessing an object with SIZE. */
710 :
711 : template <class GimpleOrTree>
712 : static bool
713 464 : maybe_warn_for_bound (opt_code opt, location_t loc, GimpleOrTree exp, tree func,
714 : tree bndrng[2], tree size, const access_data *pad)
715 : {
716 464 : if (!bndrng[0] || warning_suppressed_p (exp, opt))
717 91 : return false;
718 :
719 373 : tree maxobjsize = max_object_size ();
720 :
721 373 : bool warned = false;
722 :
723 373 : if (opt == OPT_Wstringop_overread)
724 : {
725 162 : bool maybe = pad && pad->src.phi ();
726 : if (maybe)
727 : {
728 : /* Issue a "maybe" warning only if the PHI refers to objects
729 : at least one of which has more space remaining than the bound.
730 : Otherwise, if the bound is greater, use the definitive form. */
731 2 : offset_int remmax = pad->src.size_remaining ();
732 2 : if (remmax < wi::to_offset (bndrng[0]))
733 2 : maybe = false;
734 : }
735 :
736 162 : auto_diagnostic_group d;
737 162 : if (tree_int_cst_lt (maxobjsize, bndrng[0]))
738 : {
739 75 : rich_location_with_details richloc (loc, exp);
740 75 : if (bndrng[0] == bndrng[1])
741 73 : warned = (func
742 146 : ? warning_at (&richloc, opt,
743 : (maybe
744 : ? G_("%qD specified bound %E may "
745 : "exceed maximum object size %E")
746 : : G_("%qD specified bound %E "
747 : "exceeds maximum object size %E")),
748 : func, bndrng[0], maxobjsize)
749 73 : : warning_at (&richloc, opt,
750 : (maybe
751 : ? G_("specified bound %E may "
752 : "exceed maximum object size %E")
753 : : G_("specified bound %E "
754 : "exceeds maximum object size %E")),
755 : bndrng[0], maxobjsize));
756 : else
757 2 : warned = (func
758 4 : ? warning_at (&richloc, opt,
759 : (maybe
760 : ? G_("%qD specified bound [%E, %E] may "
761 : "exceed maximum object size %E")
762 : : G_("%qD specified bound [%E, %E] "
763 : "exceeds maximum object size %E")),
764 : func,
765 : bndrng[0], bndrng[1], maxobjsize)
766 2 : : warning_at (&richloc, opt,
767 : (maybe
768 : ? G_("specified bound [%E, %E] may "
769 : "exceed maximum object size %E")
770 : : G_("specified bound [%E, %E] "
771 : "exceeds maximum object size %E")),
772 : bndrng[0], bndrng[1], maxobjsize));
773 75 : }
774 87 : else if (!size || tree_int_cst_le (bndrng[0], size))
775 4 : return false;
776 83 : else if (tree_int_cst_equal (bndrng[0], bndrng[1]))
777 : {
778 73 : rich_location_with_details richloc (loc, exp);
779 73 : warned = (func
780 146 : ? warning_at (&richloc, opt,
781 : (maybe
782 : ? G_("%qD specified bound %E may exceed "
783 : "source size %E")
784 : : G_("%qD specified bound %E exceeds "
785 : "source size %E")),
786 : func, bndrng[0], size)
787 0 : : warning_at (&richloc, opt,
788 : (maybe
789 : ? G_("specified bound %E may exceed "
790 : "source size %E")
791 : : G_("specified bound %E exceeds "
792 : "source size %E")),
793 : bndrng[0], size));
794 73 : }
795 : else
796 : {
797 10 : rich_location_with_details richloc (loc, exp);
798 10 : warned = (func
799 20 : ? warning_at (&richloc, opt,
800 : (maybe
801 : ? G_("%qD specified bound [%E, %E] may "
802 : "exceed source size %E")
803 : : G_("%qD specified bound [%E, %E] exceeds "
804 : "source size %E")),
805 : func, bndrng[0], bndrng[1], size)
806 0 : : warning_at (&richloc, opt,
807 : (maybe
808 : ? G_("specified bound [%E, %E] may exceed "
809 : "source size %E")
810 : : G_("specified bound [%E, %E] exceeds "
811 : "source size %E")),
812 : bndrng[0], bndrng[1], size));
813 10 : }
814 158 : if (warned)
815 : {
816 77 : if (pad && pad->src.ref
817 150 : && has_location (pad->src.ref))
818 49 : inform (get_location (pad->src.ref),
819 : "source object allocated here");
820 78 : suppress_warning (exp, opt);
821 : }
822 :
823 158 : return warned;
824 162 : }
825 :
826 414 : bool maybe = pad && pad->dst.phi ();
827 211 : rich_location_with_details richloc (loc, exp);
828 211 : if (maybe)
829 : {
830 : /* Issue a "maybe" warning only if the PHI refers to objects
831 : at least one of which has more space remaining than the bound.
832 : Otherwise, if the bound is greater, use the definitive form. */
833 8 : offset_int remmax = pad->dst.size_remaining ();
834 8 : if (remmax < wi::to_offset (bndrng[0]))
835 8 : maybe = false;
836 : }
837 211 : if (tree_int_cst_lt (maxobjsize, bndrng[0]))
838 : {
839 100 : if (bndrng[0] == bndrng[1])
840 81 : warned = (func
841 162 : ? warning_at (&richloc, opt,
842 : (maybe
843 : ? G_("%qD specified size %E may "
844 : "exceed maximum object size %E")
845 : : G_("%qD specified size %E "
846 : "exceeds maximum object size %E")),
847 : func, bndrng[0], maxobjsize)
848 81 : : warning_at (&richloc, opt,
849 : (maybe
850 : ? G_("specified size %E may exceed "
851 : "maximum object size %E")
852 : : G_("specified size %E exceeds "
853 : "maximum object size %E")),
854 : bndrng[0], maxobjsize));
855 : else
856 19 : warned = (func
857 38 : ? warning_at (&richloc, opt,
858 : (maybe
859 : ? G_("%qD specified size between %E and %E "
860 : "may exceed maximum object size %E")
861 : : G_("%qD specified size between %E and %E "
862 : "exceeds maximum object size %E")),
863 : func, bndrng[0], bndrng[1], maxobjsize)
864 19 : : warning_at (&richloc, opt,
865 : (maybe
866 : ? G_("specified size between %E and %E "
867 : "may exceed maximum object size %E")
868 : : G_("specified size between %E and %E "
869 : "exceeds maximum object size %E")),
870 : bndrng[0], bndrng[1], maxobjsize));
871 : }
872 111 : else if (!size || tree_int_cst_le (bndrng[0], size))
873 0 : return false;
874 111 : else if (tree_int_cst_equal (bndrng[0], bndrng[1]))
875 102 : warned = (func
876 204 : ? warning_at (&richloc, opt,
877 : (maybe
878 : ? G_("%qD specified bound %E may exceed "
879 : "destination size %E")
880 : : G_("%qD specified bound %E exceeds "
881 : "destination size %E")),
882 : func, bndrng[0], size)
883 102 : : warning_at (&richloc, opt,
884 : (maybe
885 : ? G_("specified bound %E may exceed "
886 : "destination size %E")
887 : : G_("specified bound %E exceeds "
888 : "destination size %E")),
889 : bndrng[0], size));
890 : else
891 9 : warned = (func
892 18 : ? warning_at (&richloc, opt,
893 : (maybe
894 : ? G_("%qD specified bound [%E, %E] may exceed "
895 : "destination size %E")
896 : : G_("%qD specified bound [%E, %E] exceeds "
897 : "destination size %E")),
898 : func, bndrng[0], bndrng[1], size)
899 9 : : warning_at (&richloc, opt,
900 : (maybe
901 : ? G_("specified bound [%E, %E] exceeds "
902 : "destination size %E")
903 : : G_("specified bound [%E, %E] exceeds "
904 : "destination size %E")),
905 : bndrng[0], bndrng[1], size));
906 :
907 211 : if (warned)
908 : {
909 48 : if (pad && pad->dst.ref
910 97 : && has_location (pad->dst.ref))
911 43 : inform (get_location (pad->dst.ref),
912 : "destination object allocated here");
913 52 : suppress_warning (exp, opt);
914 : }
915 :
916 : return warned;
917 211 : }
918 :
919 : bool
920 276 : maybe_warn_for_bound (opt_code opt, location_t loc, gimple *stmt, tree func,
921 : tree bndrng[2], tree size,
922 : const access_data *pad /* = NULL */)
923 : {
924 276 : return maybe_warn_for_bound<gimple *> (opt, loc, stmt, func, bndrng, size,
925 276 : pad);
926 : }
927 :
928 : bool
929 73 : maybe_warn_for_bound (opt_code opt, location_t loc, tree expr, tree func,
930 : tree bndrng[2], tree size,
931 : const access_data *pad /* = NULL */)
932 : {
933 73 : return maybe_warn_for_bound<tree> (opt, loc, expr, func, bndrng, size, pad);
934 : }
935 :
936 : /* For an expression EXP issue an access warning controlled by option OPT
937 : with access to a region SIZE bytes in size in the RANGE of sizes.
938 : WRITE is true for a write access, READ for a read access, neither for
939 : call that may or may not perform an access but for which the range
940 : is expected to valid.
941 : Returns true when a warning has been issued. */
942 :
943 : template <class GimpleOrTree>
944 : static bool
945 1898 : warn_for_access (location_t loc, tree func, GimpleOrTree exp, int opt,
946 : tree range[2], tree size, bool write, bool read, bool maybe)
947 : {
948 1898 : bool warned = false;
949 :
950 1898 : rich_location_with_details richloc (loc, exp);
951 :
952 1898 : if (write && read)
953 : {
954 138 : if (tree_int_cst_equal (range[0], range[1]))
955 138 : warned = (func
956 264 : ? warning_n (&richloc, opt, tree_to_uhwi (range[0]),
957 : (maybe
958 : ? G_("%qD may access %E byte in a region "
959 : "of size %E")
960 : : G_("%qD accessing %E byte in a region "
961 : "of size %E")),
962 : (maybe
963 : ? G_ ("%qD may access %E bytes in a region "
964 : "of size %E")
965 : : G_ ("%qD accessing %E bytes in a region "
966 : "of size %E")),
967 : func, range[0], size)
968 150 : : warning_n (&richloc, opt, tree_to_uhwi (range[0]),
969 : (maybe
970 : ? G_("may access %E byte in a region "
971 : "of size %E")
972 : : G_("accessing %E byte in a region "
973 : "of size %E")),
974 : (maybe
975 : ? G_("may access %E bytes in a region "
976 : "of size %E")
977 : : G_("accessing %E bytes in a region "
978 : "of size %E")),
979 : range[0], size));
980 0 : else if (tree_int_cst_sign_bit (range[1]))
981 : {
982 : /* Avoid printing the upper bound if it's invalid. */
983 0 : warned = (func
984 0 : ? warning_at (&richloc, opt,
985 : (maybe
986 : ? G_("%qD may access %E or more bytes "
987 : "in a region of size %E")
988 : : G_("%qD accessing %E or more bytes "
989 : "in a region of size %E")),
990 : func, range[0], size)
991 0 : : warning_at (&richloc, opt,
992 : (maybe
993 : ? G_("may access %E or more bytes "
994 : "in a region of size %E")
995 : : G_("accessing %E or more bytes "
996 : "in a region of size %E")),
997 : range[0], size));
998 : }
999 : else
1000 0 : warned = (func
1001 0 : ? warning_at (&richloc, opt,
1002 : (maybe
1003 : ? G_("%qD may access between %E and %E "
1004 : "bytes in a region of size %E")
1005 : : G_("%qD accessing between %E and %E "
1006 : "bytes in a region of size %E")),
1007 : func, range[0], range[1], size)
1008 0 : : warning_at (&richloc, opt,
1009 : (maybe
1010 : ? G_("may access between %E and %E bytes "
1011 : "in a region of size %E")
1012 : : G_("accessing between %E and %E bytes "
1013 : "in a region of size %E")),
1014 : range[0], range[1], size));
1015 138 : return warned;
1016 : }
1017 :
1018 1760 : if (write)
1019 : {
1020 1177 : if (tree_int_cst_equal (range[0], range[1]))
1021 1066 : warned = (func
1022 2130 : ? warning_n (&richloc, opt, tree_to_uhwi (range[0]),
1023 : (maybe
1024 : ? G_("%qD may write %E byte into a region "
1025 : "of size %E")
1026 : : G_("%qD writing %E byte into a region "
1027 : "of size %E overflows the destination")),
1028 : (maybe
1029 : ? G_("%qD may write %E bytes into a region "
1030 : "of size %E")
1031 : : G_("%qD writing %E bytes into a region "
1032 : "of size %E overflows the destination")),
1033 : func, range[0], size)
1034 1068 : : warning_n (&richloc, opt, tree_to_uhwi (range[0]),
1035 : (maybe
1036 : ? G_("may write %E byte into a region "
1037 : "of size %E")
1038 : : G_("writing %E byte into a region "
1039 : "of size %E overflows the destination")),
1040 : (maybe
1041 : ? G_("may write %E bytes into a region "
1042 : "of size %E")
1043 : : G_("writing %E bytes into a region "
1044 : "of size %E overflows the destination")),
1045 : range[0], size));
1046 111 : else if (tree_int_cst_sign_bit (range[1]))
1047 : {
1048 : /* Avoid printing the upper bound if it's invalid. */
1049 51 : warned = (func
1050 102 : ? warning_at (&richloc, opt,
1051 : (maybe
1052 : ? G_("%qD may write %E or more bytes "
1053 : "into a region of size %E")
1054 : : G_("%qD writing %E or more bytes "
1055 : "into a region of size %E overflows "
1056 : "the destination")),
1057 : func, range[0], size)
1058 51 : : warning_at (&richloc, opt,
1059 : (maybe
1060 : ? G_("may write %E or more bytes into "
1061 : "a region of size %E")
1062 : : G_("writing %E or more bytes into "
1063 : "a region of size %E overflows "
1064 : "the destination")),
1065 : range[0], size));
1066 : }
1067 : else
1068 60 : warned = (func
1069 120 : ? warning_at (&richloc, opt,
1070 : (maybe
1071 : ? G_("%qD may write between %E and %E bytes "
1072 : "into a region of size %E")
1073 : : G_("%qD writing between %E and %E bytes "
1074 : "into a region of size %E overflows "
1075 : "the destination")),
1076 : func, range[0], range[1], size)
1077 60 : : warning_at (&richloc, opt,
1078 : (maybe
1079 : ? G_("may write between %E and %E bytes "
1080 : "into a region of size %E")
1081 : : G_("writing between %E and %E bytes "
1082 : "into a region of size %E overflows "
1083 : "the destination")),
1084 : range[0], range[1], size));
1085 1177 : return warned;
1086 : }
1087 :
1088 583 : if (read)
1089 : {
1090 580 : if (tree_int_cst_equal (range[0], range[1]))
1091 248 : warned = (func
1092 494 : ? warning_n (&richloc, OPT_Wstringop_overread,
1093 : tree_to_uhwi (range[0]),
1094 : (maybe
1095 : ? G_("%qD may read %E byte from a region "
1096 : "of size %E")
1097 : : G_("%qD reading %E byte from a region "
1098 : "of size %E")),
1099 : (maybe
1100 : ? G_("%qD may read %E bytes from a region "
1101 : "of size %E")
1102 : : G_("%qD reading %E bytes from a region "
1103 : "of size %E")),
1104 : func, range[0], size)
1105 250 : : warning_n (&richloc, OPT_Wstringop_overread,
1106 : tree_to_uhwi (range[0]),
1107 : (maybe
1108 : ? G_("may read %E byte from a region "
1109 : "of size %E")
1110 : : G_("reading %E byte from a region "
1111 : "of size %E")),
1112 : (maybe
1113 : ? G_("may read %E bytes from a region "
1114 : "of size %E")
1115 : : G_("reading %E bytes from a region "
1116 : "of size %E")),
1117 : range[0], size));
1118 332 : else if (tree_int_cst_sign_bit (range[1]))
1119 : {
1120 : /* Avoid printing the upper bound if it's invalid. */
1121 306 : warned = (func
1122 612 : ? warning_at (&richloc, OPT_Wstringop_overread,
1123 : (maybe
1124 : ? G_("%qD may read %E or more bytes "
1125 : "from a region of size %E")
1126 : : G_("%qD reading %E or more bytes "
1127 : "from a region of size %E")),
1128 : func, range[0], size)
1129 306 : : warning_at (&richloc, OPT_Wstringop_overread,
1130 : (maybe
1131 : ? G_("may read %E or more bytes "
1132 : "from a region of size %E")
1133 : : G_("reading %E or more bytes "
1134 : "from a region of size %E")),
1135 : range[0], size));
1136 : }
1137 : else
1138 26 : warned = (func
1139 52 : ? warning_at (&richloc, OPT_Wstringop_overread,
1140 : (maybe
1141 : ? G_("%qD may read between %E and %E bytes "
1142 : "from a region of size %E")
1143 : : G_("%qD reading between %E and %E bytes "
1144 : "from a region of size %E")),
1145 : func, range[0], range[1], size)
1146 26 : : warning_at (&richloc, opt,
1147 : (maybe
1148 : ? G_("may read between %E and %E bytes "
1149 : "from a region of size %E")
1150 : : G_("reading between %E and %E bytes "
1151 : "from a region of size %E")),
1152 : range[0], range[1], size));
1153 :
1154 580 : if (warned)
1155 401 : suppress_warning (exp, OPT_Wstringop_overread);
1156 :
1157 580 : return warned;
1158 : }
1159 :
1160 3 : if (tree_int_cst_equal (range[0], range[1])
1161 3 : || tree_int_cst_sign_bit (range[1]))
1162 3 : warned = (func
1163 3 : ? warning_n (&richloc, OPT_Wstringop_overread,
1164 : tree_to_uhwi (range[0]),
1165 : "%qD expecting %E byte in a region of size %E",
1166 : "%qD expecting %E bytes in a region of size %E",
1167 : func, range[0], size)
1168 3 : : warning_n (&richloc, OPT_Wstringop_overread,
1169 : tree_to_uhwi (range[0]),
1170 : "expecting %E byte in a region of size %E",
1171 : "expecting %E bytes in a region of size %E",
1172 : range[0], size));
1173 0 : else if (tree_int_cst_sign_bit (range[1]))
1174 : {
1175 : /* Avoid printing the upper bound if it's invalid. */
1176 0 : warned = (func
1177 0 : ? warning_at (&richloc, OPT_Wstringop_overread,
1178 : "%qD expecting %E or more bytes in a region "
1179 : "of size %E",
1180 : func, range[0], size)
1181 0 : : warning_at (&richloc, OPT_Wstringop_overread,
1182 : "expecting %E or more bytes in a region "
1183 : "of size %E",
1184 : range[0], size));
1185 : }
1186 : else
1187 0 : warned = (func
1188 0 : ? warning_at (&richloc, OPT_Wstringop_overread,
1189 : "%qD expecting between %E and %E bytes in "
1190 : "a region of size %E",
1191 : func, range[0], range[1], size)
1192 0 : : warning_at (&richloc, OPT_Wstringop_overread,
1193 : "expecting between %E and %E bytes in "
1194 : "a region of size %E",
1195 : range[0], range[1], size));
1196 :
1197 3 : if (warned)
1198 3 : suppress_warning (exp, OPT_Wstringop_overread);
1199 :
1200 : return warned;
1201 1898 : }
1202 :
1203 : static bool
1204 1443 : warn_for_access (location_t loc, tree func, gimple *stmt, int opt,
1205 : tree range[2], tree size, bool write, bool read, bool maybe)
1206 : {
1207 0 : return warn_for_access<gimple *>(loc, func, stmt, opt, range, size,
1208 0 : write, read, maybe);
1209 : }
1210 :
1211 : static bool
1212 275 : warn_for_access (location_t loc, tree func, tree expr, int opt,
1213 : tree range[2], tree size, bool write, bool read, bool maybe)
1214 : {
1215 0 : return warn_for_access<tree>(loc, func, expr, opt, range, size,
1216 0 : write, read, maybe);
1217 : }
1218 :
1219 : /* Helper to set RANGE to the range of BOUND if it's nonnull, bounded
1220 : by BNDRNG if nonnull and valid. */
1221 :
1222 : static void
1223 1274046 : get_size_range (range_query *query, tree bound, gimple *stmt, tree range[2],
1224 : int flags, const offset_int bndrng[2])
1225 : {
1226 1274046 : if (bound)
1227 495400 : get_size_range (query, bound, stmt, range, flags);
1228 :
1229 1274046 : if (!bndrng || (bndrng[0] == 0 && bndrng[1] == HOST_WIDE_INT_M1U))
1230 908707 : return;
1231 :
1232 365339 : if (range[0] && TREE_CODE (range[0]) == INTEGER_CST)
1233 : {
1234 365303 : offset_int r[] =
1235 365303 : { wi::to_offset (range[0]), wi::to_offset (range[1]) };
1236 365303 : if (r[0] < bndrng[0])
1237 0 : range[0] = wide_int_to_tree (sizetype, bndrng[0]);
1238 365303 : if (bndrng[1] < r[1])
1239 3 : range[1] = wide_int_to_tree (sizetype, bndrng[1]);
1240 365303 : }
1241 : else
1242 : {
1243 36 : range[0] = wide_int_to_tree (sizetype, bndrng[0]);
1244 36 : range[1] = wide_int_to_tree (sizetype, bndrng[1]);
1245 : }
1246 : }
1247 :
1248 : /* Try to verify that the sizes and lengths of the arguments to a string
1249 : manipulation function given by EXP are within valid bounds and that
1250 : the operation does not lead to buffer overflow or read past the end.
1251 : Arguments other than EXP may be null. When non-null, the arguments
1252 : have the following meaning:
1253 : DST is the destination of a copy call or NULL otherwise.
1254 : SRC is the source of a copy call or NULL otherwise.
1255 : DSTWRITE is the number of bytes written into the destination obtained
1256 : from the user-supplied size argument to the function (such as in
1257 : memcpy(DST, SRCs, DSTWRITE) or strncpy(DST, DRC, DSTWRITE).
1258 : MAXREAD is the user-supplied bound on the length of the source sequence
1259 : (such as in strncat(d, s, N). It specifies the upper limit on the number
1260 : of bytes to write. If NULL, it's taken to be the same as DSTWRITE.
1261 : SRCSTR is the source string (such as in strcpy(DST, SRC)) when the
1262 : expression EXP is a string function call (as opposed to a memory call
1263 : like memcpy). As an exception, SRCSTR can also be an integer denoting
1264 : the precomputed size of the source string or object (for functions like
1265 : memcpy).
1266 : DSTSIZE is the size of the destination object.
1267 :
1268 : When DSTWRITE is null LEN is checked to verify that it doesn't exceed
1269 : SIZE_MAX.
1270 :
1271 : WRITE is true for write accesses, READ is true for reads. Both are
1272 : false for simple size checks in calls to functions that neither read
1273 : from nor write to the region.
1274 :
1275 : When nonnull, PAD points to a more detailed description of the access.
1276 :
1277 : If the call is successfully verified as safe return true, otherwise
1278 : return false. */
1279 :
1280 : template <class GimpleOrTree>
1281 : static bool
1282 741145 : check_access (GimpleOrTree exp, tree dstwrite,
1283 : tree maxread, tree srcstr, tree dstsize,
1284 : access_mode mode, const access_data *pad,
1285 : range_query *rvals)
1286 : {
1287 : /* The size of the largest object is half the address space, or
1288 : PTRDIFF_MAX. (This is way too permissive.) */
1289 741145 : tree maxobjsize = max_object_size ();
1290 :
1291 : /* Either an approximate/minimum the length of the source string for
1292 : string functions or the size of the source object for raw memory
1293 : functions. */
1294 741145 : tree slen = NULL_TREE;
1295 :
1296 : /* The range of the access in bytes; first set to the write access
1297 : for functions that write and then read for those that also (or
1298 : just) read. */
1299 741145 : tree range[2] = { NULL_TREE, NULL_TREE };
1300 :
1301 : /* Set to true when the exact number of bytes written by a string
1302 : function like strcpy is not known and the only thing that is
1303 : known is that it must be at least one (for the terminating nul). */
1304 741145 : bool at_least_one = false;
1305 741145 : if (srcstr)
1306 : {
1307 : /* SRCSTR is normally a pointer to string but as a special case
1308 : it can be an integer denoting the length of a string. */
1309 446091 : if (POINTER_TYPE_P (TREE_TYPE (srcstr)))
1310 : {
1311 328834 : if (!check_nul_terminated_array (exp, srcstr, maxread))
1312 : /* Return if the array is not nul-terminated and a warning
1313 : has been issued. */
1314 550 : return false;
1315 :
1316 : /* Try to determine the range of lengths the source string
1317 : refers to. If it can be determined and is less than
1318 : the upper bound given by MAXREAD add one to it for
1319 : the terminating nul. Otherwise, set it to one for
1320 : the same reason, or to MAXREAD as appropriate. */
1321 328284 : c_strlen_data lendata = { };
1322 328284 : get_range_strlen (srcstr, &lendata, /* eltsize = */ 1);
1323 328284 : range[0] = lendata.minlen;
1324 328284 : range[1] = lendata.maxbound ? lendata.maxbound : lendata.maxlen;
1325 328284 : if (range[0]
1326 328284 : && TREE_CODE (range[0]) == INTEGER_CST
1327 328279 : && TREE_CODE (range[1]) == INTEGER_CST
1328 328279 : && (!maxread || TREE_CODE (maxread) == INTEGER_CST))
1329 : {
1330 29387 : if (maxread && tree_int_cst_le (maxread, range[0]))
1331 364 : range[0] = range[1] = maxread;
1332 : else
1333 316413 : range[0] = fold_build2 (PLUS_EXPR, size_type_node,
1334 : range[0], size_one_node);
1335 :
1336 316777 : if (maxread && tree_int_cst_le (maxread, range[1]))
1337 12357 : range[1] = maxread;
1338 304420 : else if (!integer_all_onesp (range[1]))
1339 158189 : range[1] = fold_build2 (PLUS_EXPR, size_type_node,
1340 : range[1], size_one_node);
1341 :
1342 316777 : slen = range[0];
1343 : }
1344 : else
1345 : {
1346 11507 : at_least_one = true;
1347 11507 : slen = size_one_node;
1348 : }
1349 : }
1350 : else
1351 : slen = srcstr;
1352 : }
1353 :
1354 740595 : if (!dstwrite && !maxread)
1355 : {
1356 : /* When the only available piece of data is the object size
1357 : there is nothing to do. */
1358 287534 : if (!slen)
1359 : return true;
1360 :
1361 : /* Otherwise, when the length of the source sequence is known
1362 : (as with strlen), set DSTWRITE to it. */
1363 287215 : if (!range[0])
1364 67 : dstwrite = slen;
1365 : }
1366 :
1367 740276 : if (!dstsize)
1368 322937 : dstsize = maxobjsize;
1369 :
1370 : /* Set RANGE to that of DSTWRITE if non-null, bounded by PAD->DST_BNDRNG
1371 : if valid. */
1372 740276 : gimple *stmt = pad ? pad->stmt : nullptr;
1373 2218361 : get_size_range (rvals, dstwrite, stmt, range,
1374 : /* If the destination has known zero size prefer a zero
1375 : size range to avoid false positives if that's a
1376 : possibility. */
1377 740276 : integer_zerop (dstsize) ? SR_ALLOW_ZERO : 0,
1378 : pad ? pad->dst_bndrng : NULL);
1379 :
1380 740276 : tree func = get_callee_fndecl (exp);
1381 : /* Read vs write access by built-ins can be determined from the const
1382 : qualifiers on the pointer argument. In the absence of attribute
1383 : access, non-const qualified pointer arguments to user-defined
1384 : functions are assumed to both read and write the objects. */
1385 740276 : const bool builtin = func ? fndecl_built_in_p (func) : false;
1386 :
1387 : /* First check the number of bytes to be written against the maximum
1388 : object size. */
1389 740276 : if (range[0]
1390 739116 : && TREE_CODE (range[0]) == INTEGER_CST
1391 1479388 : && tree_int_cst_lt (maxobjsize, range[0]))
1392 : {
1393 138 : location_t loc = get_location (exp);
1394 138 : maybe_warn_for_bound (OPT_Wstringop_overflow_, loc, exp, func, range,
1395 : NULL_TREE, pad);
1396 138 : return false;
1397 : }
1398 :
1399 : /* The number of bytes to write is "exact" if DSTWRITE is non-null,
1400 : constant, and in range of unsigned HOST_WIDE_INT. */
1401 740138 : bool exactwrite = dstwrite && tree_fits_uhwi_p (dstwrite);
1402 :
1403 : /* Next check the number of bytes to be written against the destination
1404 : object size. */
1405 740138 : if (range[0] || !exactwrite || integer_all_onesp (dstwrite))
1406 : {
1407 740138 : if (range[0]
1408 738978 : && TREE_CODE (range[0]) == INTEGER_CST
1409 1479112 : && ((tree_fits_uhwi_p (dstsize)
1410 738657 : && tree_int_cst_lt (dstsize, range[0]))
1411 737367 : || (dstwrite
1412 411929 : && tree_fits_uhwi_p (dstwrite)
1413 326902 : && tree_int_cst_lt (dstwrite, range[0]))))
1414 : {
1415 1607 : const opt_code opt = OPT_Wstringop_overflow_;
1416 1607 : if (warning_suppressed_p (exp, opt)
1417 1607 : || (pad && pad->dst.ref
1418 902 : && warning_suppressed_p (pad->dst.ref, opt)))
1419 281 : return false;
1420 :
1421 1326 : auto_diagnostic_group d;
1422 1326 : location_t loc = get_location (exp);
1423 1326 : rich_location_with_details richloc (loc, exp);
1424 :
1425 1326 : bool warned = false;
1426 1326 : if (dstwrite == slen && at_least_one)
1427 : {
1428 : /* This is a call to strcpy with a destination of 0 size
1429 : and a source of unknown length. The call will write
1430 : at least one byte past the end of the destination. */
1431 0 : warned = (func
1432 0 : ? warning_at (&richloc, opt,
1433 : "%qD writing %E or more bytes into "
1434 : "a region of size %E overflows "
1435 : "the destination",
1436 : func, range[0], dstsize)
1437 0 : : warning_at (&richloc, opt,
1438 : "writing %E or more bytes into "
1439 : "a region of size %E overflows "
1440 : "the destination",
1441 : range[0], dstsize));
1442 : }
1443 : else
1444 : {
1445 1326 : const bool read
1446 1326 : = mode == access_read_only || mode == access_read_write;
1447 1326 : const bool write
1448 1326 : = mode == access_write_only || mode == access_read_write;
1449 1326 : const bool maybe = pad && pad->dst.parmarray;
1450 1326 : warned = warn_for_access (loc, func, exp,
1451 : OPT_Wstringop_overflow_,
1452 : range, dstsize,
1453 1326 : write, read && !builtin, maybe);
1454 : }
1455 :
1456 1326 : if (warned)
1457 : {
1458 926 : suppress_warning (exp, OPT_Wstringop_overflow_);
1459 926 : if (pad)
1460 837 : pad->dst.inform_access (pad->mode);
1461 : }
1462 :
1463 : /* Return error when an overflow has been detected. */
1464 : return false;
1465 1326 : }
1466 : }
1467 :
1468 : /* Check the maximum length of the source sequence against the size
1469 : of the destination object if known, or against the maximum size
1470 : of an object. */
1471 738531 : if (maxread)
1472 : {
1473 : /* Set RANGE to that of MAXREAD, bounded by PAD->SRC_BNDRNG if
1474 : PAD is nonnull and BNDRNG is valid. */
1475 41938 : get_size_range (rvals, maxread, stmt, range, 0,
1476 : pad ? pad->src_bndrng : NULL);
1477 :
1478 41938 : location_t loc = get_location (exp);
1479 41938 : tree size = dstsize;
1480 41938 : if (pad && pad->mode == access_read_only)
1481 38321 : size = wide_int_to_tree (sizetype, pad->src.size_remaining ());
1482 :
1483 41938 : if (range[0] && maxread && tree_fits_uhwi_p (size))
1484 : {
1485 41894 : if (tree_int_cst_lt (maxobjsize, range[0]))
1486 : {
1487 87 : maybe_warn_for_bound (OPT_Wstringop_overread, loc, exp, func,
1488 : range, size, pad);
1489 87 : return false;
1490 : }
1491 :
1492 41807 : if (size != maxobjsize && tree_int_cst_lt (size, range[0]))
1493 : {
1494 107 : opt_code opt = (dstwrite || mode != access_read_only
1495 218 : ? OPT_Wstringop_overflow_
1496 : : OPT_Wstringop_overread);
1497 218 : maybe_warn_for_bound (opt, loc, exp, func, range, size, pad);
1498 218 : return false;
1499 : }
1500 : }
1501 :
1502 41633 : maybe_warn_nonstring_arg (func, exp);
1503 : }
1504 :
1505 : /* Check for reading past the end of SRC. */
1506 1476452 : bool overread = (slen
1507 738226 : && slen == srcstr
1508 116643 : && dstwrite
1509 115824 : && range[0]
1510 115824 : && TREE_CODE (slen) == INTEGER_CST
1511 854050 : && tree_int_cst_lt (slen, range[0]));
1512 : /* If none is determined try to get a better answer based on the details
1513 : in PAD. */
1514 738226 : if (!overread
1515 738226 : && pad
1516 736376 : && pad->src.sizrng[1] >= 0
1517 501802 : && pad->src.offrng[0] >= 0
1518 1474602 : && (pad->src.offrng[1] < 0
1519 489284 : || pad->src.offrng[0] <= pad->src.offrng[1]))
1520 : {
1521 : /* Set RANGE to that of MAXREAD, bounded by PAD->SRC_BNDRNG if
1522 : PAD is nonnull and BNDRNG is valid. */
1523 489284 : get_size_range (rvals, maxread, stmt, range, 0,
1524 : pad ? pad->src_bndrng : NULL);
1525 : /* Set OVERREAD for reads starting just past the end of an object. */
1526 489284 : overread = pad->src.sizrng[1] - pad->src.offrng[0] < pad->src_bndrng[0];
1527 489284 : range[0] = wide_int_to_tree (sizetype, pad->src_bndrng[0]);
1528 489284 : slen = size_zero_node;
1529 : }
1530 :
1531 738226 : if (overread)
1532 : {
1533 667 : const opt_code opt = OPT_Wstringop_overread;
1534 667 : if (warning_suppressed_p (exp, opt)
1535 600 : || (srcstr && warning_suppressed_p (srcstr, opt))
1536 1239 : || (pad && pad->src.ref
1537 572 : && warning_suppressed_p (pad->src.ref, opt)))
1538 95 : return false;
1539 :
1540 572 : location_t loc = get_location (exp);
1541 572 : const bool read
1542 572 : = mode == access_read_only || mode == access_read_write;
1543 572 : const bool maybe = pad && pad->dst.parmarray;
1544 572 : auto_diagnostic_group d;
1545 572 : if (warn_for_access (loc, func, exp, opt, range, slen, false, read,
1546 : maybe))
1547 : {
1548 393 : suppress_warning (exp, opt);
1549 393 : if (pad)
1550 393 : pad->src.inform_access (access_read_only);
1551 : }
1552 : return false;
1553 572 : }
1554 :
1555 : return true;
1556 : }
1557 :
1558 : static bool
1559 732436 : check_access (gimple *stmt, tree dstwrite,
1560 : tree maxread, tree srcstr, tree dstsize,
1561 : access_mode mode, const access_data *pad,
1562 : range_query *rvals)
1563 : {
1564 0 : return check_access<gimple *> (stmt, dstwrite, maxread, srcstr, dstsize,
1565 0 : mode, pad, rvals);
1566 : }
1567 :
1568 : bool
1569 1983 : check_access (tree expr, tree dstwrite,
1570 : tree maxread, tree srcstr, tree dstsize,
1571 : access_mode mode, const access_data *pad /* = NULL */)
1572 : {
1573 1983 : return check_access<tree> (expr, dstwrite, maxread, srcstr, dstsize,
1574 1983 : mode, pad, nullptr);
1575 : }
1576 :
1577 : /* Return true if STMT is a call to an allocation function. Unless
1578 : ALL_ALLOC is set, consider only functions that return dynamically
1579 : allocated objects. Otherwise return true even for all forms of
1580 : alloca (including VLA). */
1581 :
1582 : static bool
1583 45959 : fndecl_alloc_p (tree fndecl, bool all_alloc)
1584 : {
1585 45959 : if (!fndecl)
1586 : return false;
1587 :
1588 : /* A call to operator new isn't recognized as one to a built-in. */
1589 45854 : if (DECL_IS_OPERATOR_NEW_P (fndecl))
1590 : return true;
1591 :
1592 33893 : if (fndecl_built_in_p (fndecl, BUILT_IN_NORMAL))
1593 : {
1594 29416 : switch (DECL_FUNCTION_CODE (fndecl))
1595 : {
1596 : case BUILT_IN_ALLOCA:
1597 : case BUILT_IN_ALLOCA_WITH_ALIGN:
1598 : return all_alloc;
1599 : case BUILT_IN_ALIGNED_ALLOC:
1600 : case BUILT_IN_CALLOC:
1601 : case BUILT_IN_GOMP_ALLOC:
1602 : case BUILT_IN_GOMP_REALLOC:
1603 : case BUILT_IN_MALLOC:
1604 : case BUILT_IN_REALLOC:
1605 : case BUILT_IN_STRDUP:
1606 : case BUILT_IN_STRNDUP:
1607 : return true;
1608 : default:
1609 : break;
1610 : }
1611 : }
1612 :
1613 : /* A function is considered an allocation function if it's declared
1614 : with attribute malloc with an argument naming its associated
1615 : deallocation function. */
1616 4488 : tree attrs = DECL_ATTRIBUTES (fndecl);
1617 4488 : if (!attrs)
1618 : return false;
1619 :
1620 103 : for (tree allocs = attrs;
1621 1837 : (allocs = lookup_attribute ("malloc", allocs));
1622 103 : allocs = TREE_CHAIN (allocs))
1623 : {
1624 1005 : tree args = TREE_VALUE (allocs);
1625 1005 : if (!args)
1626 103 : continue;
1627 :
1628 902 : if (TREE_VALUE (args))
1629 : return true;
1630 : }
1631 :
1632 : return false;
1633 : }
1634 :
1635 : /* Return true if STMT is a call to an allocation function. A wrapper
1636 : around fndecl_alloc_p. */
1637 :
1638 : static bool
1639 45959 : gimple_call_alloc_p (gimple *stmt, bool all_alloc = false)
1640 : {
1641 45959 : return fndecl_alloc_p (gimple_call_fndecl (stmt), all_alloc);
1642 : }
1643 :
1644 : /* Return true if DELC doesn't refer to an operator delete that's
1645 : suitable to call with a pointer returned from the operator new
1646 : described by NEWC. */
1647 :
1648 : static bool
1649 2438 : new_delete_mismatch_p (const demangle_component &newc,
1650 : const demangle_component &delc)
1651 : {
1652 3752 : if (newc.type != delc.type)
1653 : return true;
1654 :
1655 3636 : switch (newc.type)
1656 : {
1657 1015 : case DEMANGLE_COMPONENT_NAME:
1658 1015 : {
1659 1015 : int len = newc.u.s_name.len;
1660 1015 : const char *news = newc.u.s_name.s;
1661 1015 : const char *dels = delc.u.s_name.s;
1662 1015 : if (len != delc.u.s_name.len || memcmp (news, dels, len))
1663 : return true;
1664 :
1665 1000 : if (news[len] == 'n')
1666 : {
1667 369 : if (news[len + 1] == 'a')
1668 126 : return dels[len] != 'd' || dels[len + 1] != 'a';
1669 264 : if (news[len + 1] == 'w')
1670 276 : return dels[len] != 'd' || dels[len + 1] != 'l';
1671 : }
1672 : return false;
1673 : }
1674 :
1675 : case DEMANGLE_COMPONENT_OPERATOR:
1676 : /* Operator mismatches are handled above. */
1677 : return false;
1678 :
1679 0 : case DEMANGLE_COMPONENT_EXTENDED_OPERATOR:
1680 0 : if (newc.u.s_extended_operator.args != delc.u.s_extended_operator.args)
1681 : return true;
1682 0 : return new_delete_mismatch_p (*newc.u.s_extended_operator.name,
1683 0 : *delc.u.s_extended_operator.name);
1684 :
1685 0 : case DEMANGLE_COMPONENT_FIXED_TYPE:
1686 0 : if (newc.u.s_fixed.accum != delc.u.s_fixed.accum
1687 0 : || newc.u.s_fixed.sat != delc.u.s_fixed.sat)
1688 : return true;
1689 0 : return new_delete_mismatch_p (*newc.u.s_fixed.length,
1690 0 : *delc.u.s_fixed.length);
1691 :
1692 0 : case DEMANGLE_COMPONENT_CTOR:
1693 0 : if (newc.u.s_ctor.kind != delc.u.s_ctor.kind)
1694 : return true;
1695 0 : return new_delete_mismatch_p (*newc.u.s_ctor.name,
1696 0 : *delc.u.s_ctor.name);
1697 :
1698 0 : case DEMANGLE_COMPONENT_DTOR:
1699 0 : if (newc.u.s_dtor.kind != delc.u.s_dtor.kind)
1700 : return true;
1701 0 : return new_delete_mismatch_p (*newc.u.s_dtor.name,
1702 0 : *delc.u.s_dtor.name);
1703 :
1704 327 : case DEMANGLE_COMPONENT_EXTENDED_BUILTIN_TYPE:
1705 327 : case DEMANGLE_COMPONENT_BUILTIN_TYPE:
1706 327 : {
1707 : /* The demangler API provides no better way to compare built-in
1708 : types except to by comparing their demangled names. */
1709 327 : size_t nsz, dsz;
1710 327 : demangle_component *pnc = const_cast<demangle_component *>(&newc);
1711 327 : demangle_component *pdc = const_cast<demangle_component *>(&delc);
1712 327 : char *nts = cplus_demangle_print (0, pnc, 16, &nsz);
1713 327 : char *dts = cplus_demangle_print (0, pdc, 16, &dsz);
1714 327 : if (!nts != !dts)
1715 : return true;
1716 327 : bool mismatch = strcmp (nts, dts);
1717 327 : free (nts);
1718 327 : free (dts);
1719 327 : return mismatch;
1720 : }
1721 :
1722 0 : case DEMANGLE_COMPONENT_SUB_STD:
1723 0 : if (newc.u.s_string.len != delc.u.s_string.len)
1724 : return true;
1725 0 : return memcmp (newc.u.s_string.string, delc.u.s_string.string,
1726 0 : newc.u.s_string.len);
1727 :
1728 6 : case DEMANGLE_COMPONENT_FUNCTION_PARAM:
1729 6 : case DEMANGLE_COMPONENT_TEMPLATE_PARAM:
1730 6 : case DEMANGLE_COMPONENT_UNNAMED_TYPE:
1731 6 : return newc.u.s_number.number != delc.u.s_number.number;
1732 :
1733 0 : case DEMANGLE_COMPONENT_CHARACTER:
1734 0 : return newc.u.s_character.character != delc.u.s_character.character;
1735 :
1736 0 : case DEMANGLE_COMPONENT_DEFAULT_ARG:
1737 0 : case DEMANGLE_COMPONENT_LAMBDA:
1738 0 : if (newc.u.s_unary_num.num != delc.u.s_unary_num.num)
1739 : return true;
1740 0 : return new_delete_mismatch_p (*newc.u.s_unary_num.sub,
1741 0 : *delc.u.s_unary_num.sub);
1742 1753 : default:
1743 1753 : break;
1744 : }
1745 :
1746 1753 : if (!newc.u.s_binary.left != !delc.u.s_binary.left)
1747 : return true;
1748 :
1749 1753 : if (!newc.u.s_binary.left)
1750 : return false;
1751 :
1752 1727 : if (new_delete_mismatch_p (*newc.u.s_binary.left, *delc.u.s_binary.left)
1753 1727 : || !newc.u.s_binary.right != !delc.u.s_binary.right)
1754 : return true;
1755 :
1756 1613 : if (newc.u.s_binary.right)
1757 : return new_delete_mismatch_p (*newc.u.s_binary.right,
1758 : *delc.u.s_binary.right);
1759 : return false;
1760 : }
1761 :
1762 : /* Return true if DELETE_DECL is an operator delete that's not suitable
1763 : to call with a pointer returned from NEW_DECL. */
1764 :
1765 : static bool
1766 11932 : new_delete_mismatch_p (tree new_decl, tree delete_decl)
1767 : {
1768 11932 : tree new_name = DECL_ASSEMBLER_NAME (new_decl);
1769 11932 : tree delete_name = DECL_ASSEMBLER_NAME (delete_decl);
1770 :
1771 : /* valid_new_delete_pair_p() returns a conservative result (currently
1772 : it only handles global operators). A true result is reliable but
1773 : a false result doesn't necessarily mean the operators don't match
1774 : unless CERTAIN is set. */
1775 11932 : bool certain;
1776 11932 : if (valid_new_delete_pair_p (new_name, delete_name, &certain))
1777 : return false;
1778 : /* CERTAIN is set when the negative result is certain. */
1779 760 : if (certain)
1780 : return true;
1781 :
1782 : /* For anything not handled by valid_new_delete_pair_p() such as member
1783 : operators compare the individual demangled components of the mangled
1784 : name. */
1785 717 : const char *new_str = IDENTIFIER_POINTER (new_name);
1786 717 : const char *del_str = IDENTIFIER_POINTER (delete_name);
1787 :
1788 717 : void *np = NULL, *dp = NULL;
1789 717 : demangle_component *ndc = cplus_demangle_v3_components (new_str, 0, &np);
1790 717 : demangle_component *ddc = cplus_demangle_v3_components (del_str, 0, &dp);
1791 :
1792 : /* Sometimes, notably quite often with coroutines, 'operator new' is
1793 : templated. However, template arguments can't change whether a given
1794 : new/delete is a singleton or array one, nor what it is a member of, so
1795 : the template arguments can be safely ignored for the purposes of checking
1796 : for mismatches. */
1797 :
1798 2139 : auto strip_dc_template = [] (demangle_component* dc)
1799 : {
1800 711 : if (dc->type == DEMANGLE_COMPONENT_TEMPLATE)
1801 57 : dc = dc->u.s_binary.left;
1802 1422 : return dc;
1803 : };
1804 :
1805 717 : bool mismatch = (ndc && ddc
1806 1428 : && new_delete_mismatch_p (*strip_dc_template (ndc),
1807 711 : *strip_dc_template (ddc)));
1808 717 : free (np);
1809 717 : free (dp);
1810 717 : return mismatch;
1811 : }
1812 :
1813 : /* ALLOC_DECL and DEALLOC_DECL are pair of allocation and deallocation
1814 : functions. Return true if the latter is suitable to deallocate objects
1815 : allocated by calls to the former. */
1816 :
1817 : static bool
1818 44590 : matching_alloc_calls_p (tree alloc_decl, tree dealloc_decl)
1819 : {
1820 : /* Set to alloc_kind_t::builtin if ALLOC_DECL is associated with
1821 : a built-in deallocator. */
1822 44590 : enum class alloc_kind_t { none, builtin, user }
1823 44590 : alloc_dealloc_kind = alloc_kind_t::none;
1824 :
1825 44590 : if (DECL_IS_OPERATOR_NEW_P (alloc_decl))
1826 : {
1827 11961 : if (DECL_IS_OPERATOR_DELETE_P (dealloc_decl))
1828 : /* Return true iff both functions are of the same array or
1829 : singleton form and false otherwise. */
1830 11932 : return !new_delete_mismatch_p (alloc_decl, dealloc_decl);
1831 :
1832 : /* Return false for deallocation functions that are known not
1833 : to match. */
1834 29 : if (fndecl_built_in_p (dealloc_decl, BUILT_IN_FREE, BUILT_IN_REALLOC))
1835 : return false;
1836 : /* Otherwise proceed below to check the deallocation function's
1837 : "*dealloc" attributes to look for one that mentions this operator
1838 : new. */
1839 : }
1840 32629 : else if (fndecl_built_in_p (alloc_decl, BUILT_IN_NORMAL))
1841 : {
1842 31715 : switch (DECL_FUNCTION_CODE (alloc_decl))
1843 : {
1844 : case BUILT_IN_ALLOCA:
1845 : case BUILT_IN_ALLOCA_WITH_ALIGN:
1846 : return false;
1847 :
1848 1223 : case BUILT_IN_GOMP_ALLOC:
1849 1223 : case BUILT_IN_GOMP_REALLOC:
1850 1223 : if (DECL_IS_OPERATOR_DELETE_P (dealloc_decl))
1851 : return false;
1852 :
1853 1223 : if (fndecl_built_in_p (dealloc_decl, BUILT_IN_GOMP_FREE,
1854 : BUILT_IN_GOMP_REALLOC))
1855 : return true;
1856 :
1857 : alloc_dealloc_kind = alloc_kind_t::builtin;
1858 : break;
1859 :
1860 30492 : case BUILT_IN_ALIGNED_ALLOC:
1861 30492 : case BUILT_IN_CALLOC:
1862 30492 : case BUILT_IN_MALLOC:
1863 30492 : case BUILT_IN_REALLOC:
1864 30492 : case BUILT_IN_STRDUP:
1865 30492 : case BUILT_IN_STRNDUP:
1866 30492 : if (DECL_IS_OPERATOR_DELETE_P (dealloc_decl))
1867 : return false;
1868 :
1869 30417 : if (fndecl_built_in_p (dealloc_decl, BUILT_IN_FREE,
1870 : BUILT_IN_REALLOC))
1871 : return true;
1872 :
1873 : alloc_dealloc_kind = alloc_kind_t::builtin;
1874 : break;
1875 :
1876 : default:
1877 : break;
1878 : }
1879 : }
1880 :
1881 : /* Set if DEALLOC_DECL both allocates and deallocates. */
1882 953 : alloc_kind_t realloc_kind = alloc_kind_t::none;
1883 :
1884 953 : if (fndecl_built_in_p (dealloc_decl, BUILT_IN_NORMAL))
1885 : {
1886 129 : built_in_function dealloc_code = DECL_FUNCTION_CODE (dealloc_decl);
1887 129 : if (dealloc_code == BUILT_IN_REALLOC
1888 129 : || dealloc_code == BUILT_IN_GOMP_REALLOC)
1889 26 : realloc_kind = alloc_kind_t::builtin;
1890 :
1891 129 : for (tree amats = DECL_ATTRIBUTES (alloc_decl);
1892 224 : (amats = lookup_attribute ("malloc", amats));
1893 95 : amats = TREE_CHAIN (amats))
1894 : {
1895 163 : tree args = TREE_VALUE (amats);
1896 163 : if (!args)
1897 0 : continue;
1898 :
1899 163 : tree fndecl = TREE_VALUE (args);
1900 163 : if (!fndecl || !DECL_P (fndecl))
1901 0 : continue;
1902 :
1903 163 : if (fndecl_built_in_p (fndecl, BUILT_IN_NORMAL)
1904 163 : && dealloc_code == DECL_FUNCTION_CODE (fndecl))
1905 : return true;
1906 : }
1907 : }
1908 :
1909 885 : const bool alloc_builtin = fndecl_built_in_p (alloc_decl, BUILT_IN_NORMAL);
1910 885 : alloc_kind_t realloc_dealloc_kind = alloc_kind_t::none;
1911 :
1912 : /* If DEALLOC_DECL has an internal "*dealloc" attribute scan the list
1913 : of its associated allocation functions for ALLOC_DECL.
1914 : If the corresponding ALLOC_DECL is found they're a matching pair,
1915 : otherwise they're not.
1916 : With DDATS set to the Deallocator's *Dealloc ATtributes... */
1917 885 : for (tree ddats = DECL_ATTRIBUTES (dealloc_decl);
1918 3131 : (ddats = lookup_attribute ("*dealloc", ddats));
1919 2246 : ddats = TREE_CHAIN (ddats))
1920 : {
1921 2964 : tree args = TREE_VALUE (ddats);
1922 2964 : if (!args)
1923 0 : continue;
1924 :
1925 2964 : tree alloc = TREE_VALUE (args);
1926 2964 : if (!alloc)
1927 0 : continue;
1928 :
1929 2964 : if (alloc == DECL_NAME (dealloc_decl))
1930 44 : realloc_kind = alloc_kind_t::user;
1931 :
1932 2964 : if (DECL_P (alloc))
1933 : {
1934 0 : gcc_checking_assert (fndecl_built_in_p (alloc, BUILT_IN_NORMAL));
1935 :
1936 0 : switch (DECL_FUNCTION_CODE (alloc))
1937 : {
1938 0 : case BUILT_IN_ALIGNED_ALLOC:
1939 0 : case BUILT_IN_CALLOC:
1940 0 : case BUILT_IN_GOMP_ALLOC:
1941 0 : case BUILT_IN_GOMP_REALLOC:
1942 0 : case BUILT_IN_MALLOC:
1943 0 : case BUILT_IN_REALLOC:
1944 0 : case BUILT_IN_STRDUP:
1945 0 : case BUILT_IN_STRNDUP:
1946 0 : realloc_dealloc_kind = alloc_kind_t::builtin;
1947 0 : break;
1948 : default:
1949 : break;
1950 : }
1951 :
1952 0 : if (!alloc_builtin)
1953 0 : continue;
1954 :
1955 0 : if (DECL_FUNCTION_CODE (alloc) != DECL_FUNCTION_CODE (alloc_decl))
1956 0 : continue;
1957 :
1958 : return true;
1959 : }
1960 :
1961 2964 : if (alloc == DECL_NAME (alloc_decl))
1962 : return true;
1963 : }
1964 :
1965 167 : if (realloc_kind == alloc_kind_t::none)
1966 : return false;
1967 :
1968 108 : hash_set<tree> common_deallocs;
1969 : /* Special handling for deallocators. Iterate over both the allocator's
1970 : and the reallocator's associated deallocator functions looking for
1971 : the first one in common. If one is found, the de/reallocator is
1972 : a match for the allocator even though the latter isn't directly
1973 : associated with the former. This simplifies declarations in system
1974 : headers.
1975 : With AMATS set to the Allocator's Malloc ATtributes,
1976 : and RMATS set to Reallocator's Malloc ATtributes... */
1977 114 : for (tree amats = DECL_ATTRIBUTES (alloc_decl);
1978 114 : (amats = lookup_attribute ("malloc", amats));
1979 60 : amats = amats ? TREE_CHAIN (amats) : NULL_TREE)
1980 68 : if (tree args = amats ? TREE_VALUE (amats) : NULL_TREE)
1981 58 : if (tree adealloc = TREE_VALUE (args))
1982 : {
1983 58 : if (DECL_P (adealloc)
1984 58 : && fndecl_built_in_p (adealloc, BUILT_IN_NORMAL))
1985 : {
1986 12 : built_in_function fncode = DECL_FUNCTION_CODE (adealloc);
1987 12 : if (fncode == BUILT_IN_FREE || fncode == BUILT_IN_REALLOC)
1988 : {
1989 12 : if (realloc_kind == alloc_kind_t::builtin)
1990 8 : return true;
1991 : alloc_dealloc_kind = alloc_kind_t::builtin;
1992 : }
1993 4 : continue;
1994 4 : }
1995 :
1996 46 : common_deallocs.add (adealloc);
1997 : }
1998 82 : for (tree rmats = DECL_ATTRIBUTES (dealloc_decl);
1999 82 : (rmats = lookup_attribute ("malloc", rmats));
2000 36 : rmats = rmats ? TREE_CHAIN (rmats) : NULL_TREE)
2001 56 : if (tree args = rmats ? TREE_VALUE (rmats) : NULL_TREE)
2002 56 : if (tree ddealloc = TREE_VALUE (args))
2003 : {
2004 56 : if (DECL_P (ddealloc)
2005 56 : && fndecl_built_in_p (ddealloc, BUILT_IN_NORMAL))
2006 : {
2007 16 : built_in_function fncode = DECL_FUNCTION_CODE (ddealloc);
2008 16 : if (fncode == BUILT_IN_FREE || fncode == BUILT_IN_REALLOC)
2009 : {
2010 16 : if (alloc_dealloc_kind == alloc_kind_t::builtin)
2011 20 : return true;
2012 : realloc_dealloc_kind = alloc_kind_t::builtin;
2013 : }
2014 1 : continue;
2015 1 : }
2016 :
2017 40 : if (common_deallocs.contains (ddealloc))
2018 : return true;
2019 : }
2020 :
2021 : /* Succeed only if ALLOC_DECL and the reallocator DEALLOC_DECL share
2022 : a built-in deallocator. */
2023 26 : return (alloc_dealloc_kind == alloc_kind_t::builtin
2024 26 : && realloc_dealloc_kind == alloc_kind_t::builtin);
2025 : }
2026 :
2027 : /* Return true if DEALLOC_DECL is a function suitable to deallocate
2028 : objects allocated by the ALLOC call. */
2029 :
2030 : static bool
2031 44590 : matching_alloc_calls_p (gimple *alloc, tree dealloc_decl)
2032 : {
2033 44590 : tree alloc_decl = gimple_call_fndecl (alloc);
2034 44590 : if (!alloc_decl)
2035 : return true;
2036 :
2037 44590 : return matching_alloc_calls_p (alloc_decl, dealloc_decl);
2038 : }
2039 :
2040 : /* Diagnose a call EXP to deallocate a pointer referenced by AREF if it
2041 : includes a nonzero offset. Such a pointer cannot refer to the beginning
2042 : of an allocated object. A negative offset may refer to it only if
2043 : the target pointer is unknown. */
2044 :
2045 : static bool
2046 164137 : warn_dealloc_offset (location_t loc, gimple *call, const access_ref &aref)
2047 : {
2048 164137 : if (aref.deref || aref.offrng[0] <= 0 || aref.offrng[1] <= 0)
2049 164062 : return false;
2050 :
2051 75 : tree dealloc_decl = gimple_call_fndecl (call);
2052 75 : if (!dealloc_decl)
2053 : return false;
2054 :
2055 75 : if (DECL_IS_OPERATOR_DELETE_P (dealloc_decl)
2056 75 : && !DECL_IS_REPLACEABLE_OPERATOR (dealloc_decl))
2057 : {
2058 : /* A call to a user-defined operator delete with a pointer plus offset
2059 : may be valid if it's returned from an unknown function (i.e., one
2060 : that's not operator new). */
2061 6 : if (TREE_CODE (aref.ref) == SSA_NAME)
2062 : {
2063 6 : gimple *def_stmt = SSA_NAME_DEF_STMT (aref.ref);
2064 6 : if (is_gimple_call (def_stmt))
2065 : {
2066 6 : tree alloc_decl = gimple_call_fndecl (def_stmt);
2067 9 : if (!alloc_decl || !DECL_IS_OPERATOR_NEW_P (alloc_decl))
2068 : return false;
2069 : }
2070 : }
2071 : }
2072 :
2073 69 : char offstr[80];
2074 69 : offstr[0] = '\0';
2075 69 : if (wi::fits_shwi_p (aref.offrng[0]))
2076 : {
2077 69 : if (aref.offrng[0] == aref.offrng[1]
2078 69 : || !wi::fits_shwi_p (aref.offrng[1]))
2079 55 : sprintf (offstr, " %lli",
2080 55 : (long long)aref.offrng[0].to_shwi ());
2081 : else
2082 14 : sprintf (offstr, " [%lli, %lli]",
2083 14 : (long long)aref.offrng[0].to_shwi (),
2084 14 : (long long)aref.offrng[1].to_shwi ());
2085 : }
2086 :
2087 69 : auto_diagnostic_group d;
2088 69 : if (!warning_at (loc, OPT_Wfree_nonheap_object,
2089 : "%qD called on pointer %qE with nonzero offset%s",
2090 69 : dealloc_decl, aref.ref, offstr))
2091 : return false;
2092 :
2093 69 : if (DECL_P (aref.ref))
2094 8 : inform (get_location (aref.ref), "declared here");
2095 61 : else if (TREE_CODE (aref.ref) == SSA_NAME)
2096 : {
2097 59 : gimple *def_stmt = SSA_NAME_DEF_STMT (aref.ref);
2098 59 : if (is_gimple_call (def_stmt))
2099 : {
2100 53 : location_t def_loc = get_location (def_stmt);
2101 53 : tree alloc_decl = gimple_call_fndecl (def_stmt);
2102 53 : if (alloc_decl)
2103 53 : inform (def_loc,
2104 : "returned from %qD", alloc_decl);
2105 0 : else if (tree alloc_fntype = gimple_call_fntype (def_stmt))
2106 0 : inform (def_loc,
2107 : "returned from %qT", alloc_fntype);
2108 : else
2109 0 : inform (def_loc, "obtained here");
2110 : }
2111 : }
2112 :
2113 : return true;
2114 69 : }
2115 :
2116 : namespace {
2117 :
2118 : const pass_data pass_data_waccess = {
2119 : GIMPLE_PASS,
2120 : "waccess",
2121 : OPTGROUP_NONE,
2122 : TV_WARN_ACCESS, /* timer variable */
2123 : PROP_cfg, /* properties_required */
2124 : 0, /* properties_provided */
2125 : 0, /* properties_destroyed */
2126 : 0, /* properties_start */
2127 : 0, /* properties_finish */
2128 : };
2129 :
2130 : /* Pass to detect invalid accesses. */
2131 : class pass_waccess : public gimple_opt_pass
2132 : {
2133 : public:
2134 : pass_waccess (gcc::context *);
2135 :
2136 : ~pass_waccess ();
2137 :
2138 : opt_pass *clone () final override;
2139 :
2140 : bool gate (function *) final override;
2141 :
2142 : void set_pass_param (unsigned, bool) final override;
2143 :
2144 : unsigned int execute (function *) final override;
2145 :
2146 : private:
2147 : /* Not copyable or assignable. */
2148 : pass_waccess (pass_waccess &) = delete;
2149 : void operator= (pass_waccess &) = delete;
2150 :
2151 : /* Check a call to an atomic built-in function. */
2152 : bool check_atomic_builtin (gcall *);
2153 :
2154 : /* Check a call to a built-in function. */
2155 : bool check_builtin (gcall *);
2156 :
2157 : /* Check a call to an ordinary function for invalid accesses. */
2158 : bool check_call_access (gcall *);
2159 :
2160 : /* Check a non-call statement. */
2161 : void check_stmt (gimple *);
2162 :
2163 : /* Check statements in a basic block. */
2164 : void check_block (basic_block);
2165 :
2166 : /* Check a call to a function. */
2167 : void check_call (gcall *);
2168 :
2169 : /* Check a call to the named built-in function. */
2170 : void check_alloca (gcall *);
2171 : void check_alloc_size_call (gcall *);
2172 : void check_strcat (gcall *);
2173 : void check_strncat (gcall *);
2174 : void check_stxcpy (gcall *);
2175 : void check_stxncpy (gcall *);
2176 : void check_strncmp (gcall *);
2177 : void check_memop_access (gimple *, tree, tree, tree);
2178 : void check_read_access (gimple *, tree, tree = NULL_TREE, int = 1);
2179 :
2180 : void maybe_check_dealloc_call (gcall *);
2181 : void maybe_check_access_sizes (rdwr_map *, tree, tree, gimple *);
2182 : bool maybe_warn_memmodel (gimple *, tree, tree, const unsigned char *);
2183 : void check_atomic_memmodel (gimple *, tree, tree, const unsigned char *);
2184 :
2185 : /* Check for uses of indeterminate pointers. */
2186 : void check_pointer_uses (gimple *, tree, tree = NULL_TREE, bool = false);
2187 :
2188 : /* Return the argument that a call returns. */
2189 : tree gimple_call_return_arg (gcall *);
2190 :
2191 : /* Check a call for uses of a dangling pointer arguments. */
2192 : void check_call_dangling (gcall *);
2193 :
2194 : /* Check uses of a dangling pointer or those derived from it. */
2195 : void check_dangling_uses (tree, tree, bool = false, bool = false);
2196 : void check_dangling_uses ();
2197 : void check_dangling_stores ();
2198 : bool check_dangling_stores (basic_block, hash_set<tree> &);
2199 :
2200 : void warn_invalid_pointer (tree, gimple *, gimple *, tree, bool, bool = false);
2201 :
2202 : /* Return true if use follows an invalidating statement. */
2203 : bool use_after_inval_p (gimple *, gimple *, bool = false);
2204 :
2205 : /* A pointer_query object to store information about pointers and
2206 : their targets in. */
2207 : pointer_query m_ptr_qry;
2208 : /* Mapping from DECLs and their clobber statements in the function. */
2209 : hash_map<tree, gimple *> m_clobbers;
2210 : /* A bit is set for each basic block whose statements have been assigned
2211 : valid UIDs. */
2212 : bitmap m_bb_uids_set;
2213 : /* The current function. */
2214 : function *m_func;
2215 : /* True to run checks for uses of dangling pointers. */
2216 : bool m_check_dangling_p;
2217 : /* True to run checks early on in the optimization pipeline. */
2218 : bool m_early_checks_p;
2219 : };
2220 :
2221 : /* Construct the pass. */
2222 :
2223 857166 : pass_waccess::pass_waccess (gcc::context *ctxt)
2224 : : gimple_opt_pass (pass_data_waccess, ctxt),
2225 857166 : m_ptr_qry (NULL),
2226 857166 : m_clobbers (),
2227 857166 : m_bb_uids_set (),
2228 857166 : m_func (),
2229 857166 : m_check_dangling_p (),
2230 857166 : m_early_checks_p ()
2231 : {
2232 857166 : }
2233 :
2234 : /* Return a copy of the pass with RUN_NUMBER one greater than THIS. */
2235 :
2236 : opt_pass*
2237 571444 : pass_waccess::clone ()
2238 : {
2239 571444 : return new pass_waccess (m_ctxt);
2240 : }
2241 :
2242 : /* Release pointer_query cache. */
2243 :
2244 1539726 : pass_waccess::~pass_waccess ()
2245 : {
2246 769863 : m_ptr_qry.flush_cache ();
2247 1539726 : }
2248 :
2249 : void
2250 1714332 : pass_waccess::set_pass_param (unsigned int n, bool param)
2251 : {
2252 : /* Check for dangling pointers in the earliest runs of the pass.
2253 : The latest point -Wdangling-pointer should run is just before
2254 : loop unrolling which introduces uses after clobbers. Most cases
2255 : can be detected without optimization; cases where the address of
2256 : the local variable is passed to and then returned from a user-
2257 : defined function before its lifetime ends and the returned pointer
2258 : becomes dangling depend on inlining. */
2259 1714332 : if (n == 0)
2260 857166 : m_early_checks_p = param;
2261 857166 : else if (n == 1)
2262 857166 : m_check_dangling_p = param;
2263 : else
2264 0 : __builtin_unreachable ();
2265 1714332 : }
2266 :
2267 : /* Return true when any checks performed by the pass are enabled. */
2268 :
2269 : bool
2270 5362298 : pass_waccess::gate (function *)
2271 : {
2272 5362298 : return (warn_free_nonheap_object
2273 117 : || warn_mismatched_alloc
2274 5362415 : || warn_mismatched_new_delete);
2275 : }
2276 :
2277 : /* Initialize ALLOC_OBJECT_SIZE_LIMIT based on the -Walloc-size-larger-than=
2278 : setting if the option is specified, or to the maximum object size if it
2279 : is not. Return the initialized value. */
2280 :
2281 : static tree
2282 74326 : alloc_max_size (void)
2283 : {
2284 74326 : HOST_WIDE_INT limit = warn_alloc_size_limit;
2285 74326 : if (limit == HOST_WIDE_INT_MAX)
2286 73930 : limit = tree_to_shwi (TYPE_MAX_VALUE (ptrdiff_type_node));
2287 :
2288 74326 : return build_int_cst (size_type_node, limit);
2289 : }
2290 :
2291 : /* Diagnose a call EXP to function FN decorated with attribute alloc_size
2292 : whose argument numbers given by IDX with values given by ARGS exceed
2293 : the maximum object size or cause an unsigned overflow (wrapping) when
2294 : multiplied. FN is null when EXP is a call via a function pointer.
2295 : When ARGS[0] is null the function does nothing. ARGS[1] may be null
2296 : for functions like malloc, and non-null for those like calloc that
2297 : are decorated with a two-argument attribute alloc_size. */
2298 :
2299 : void
2300 74326 : maybe_warn_alloc_args_overflow (gimple *stmt, const tree args[2],
2301 : const int idx[2])
2302 : {
2303 : /* The range each of the (up to) two arguments is known to be in. */
2304 74326 : tree argrange[2][2] = { { NULL_TREE, NULL_TREE }, { NULL_TREE, NULL_TREE } };
2305 :
2306 : /* Maximum object size set by -Walloc-size-larger-than= or SIZE_MAX / 2. */
2307 74326 : tree maxobjsize = alloc_max_size ();
2308 :
2309 74326 : location_t loc = get_location (stmt);
2310 :
2311 74326 : tree fn = gimple_call_fndecl (stmt);
2312 74326 : tree fntype = fn ? TREE_TYPE (fn) : gimple_call_fntype (stmt);
2313 74326 : bool warned = false;
2314 :
2315 : /* Validate each argument individually. */
2316 149935 : for (unsigned i = 0; i != 2 && args[i]; ++i)
2317 : {
2318 75609 : if (TREE_CODE (args[i]) == INTEGER_CST)
2319 : {
2320 38488 : argrange[i][0] = args[i];
2321 38488 : argrange[i][1] = args[i];
2322 :
2323 38488 : if (tree_int_cst_lt (args[i], integer_zero_node))
2324 : {
2325 24 : warned = warning_at (loc, OPT_Walloc_size_larger_than_,
2326 : "argument %i value %qE is negative",
2327 24 : idx[i] + 1, args[i]);
2328 : }
2329 38464 : else if (integer_zerop (args[i]))
2330 : {
2331 : /* Avoid issuing -Walloc-zero for allocation functions other
2332 : than __builtin_alloca that are declared with attribute
2333 : returns_nonnull because there's no portability risk. This
2334 : avoids warning for such calls to libiberty's xmalloc and
2335 : friends.
2336 : Also avoid issuing the warning for calls to function named
2337 : "alloca". */
2338 942 : if (fn && fndecl_built_in_p (fn, BUILT_IN_ALLOCA)
2339 964 : ? IDENTIFIER_LENGTH (DECL_NAME (fn)) != 6
2340 482 : : !lookup_attribute ("returns_nonnull",
2341 482 : TYPE_ATTRIBUTES (fntype)))
2342 475 : warned = warning_at (loc, OPT_Walloc_zero,
2343 : "argument %i value is zero",
2344 475 : idx[i] + 1);
2345 : }
2346 37982 : else if (tree_int_cst_lt (maxobjsize, args[i]))
2347 : {
2348 : /* G++ emits calls to ::operator new[](SIZE_MAX) in C++98 mode or
2349 : with -fno-exceptions as a way to indicate array size overflow.
2350 : Avoid diagnosing these calls. Additionally, see e.g. PR99934,
2351 : G++ also potentially generates such calls in C++11 and later as
2352 : well, so suppress the diagnostic in all C++ modes. */
2353 130 : if (i == 0
2354 107 : && fn
2355 89 : && !args[1]
2356 81 : && DECL_IS_OPERATOR_NEW_P (fn)
2357 130 : && integer_all_onesp (args[i]))
2358 23 : continue;
2359 :
2360 84 : warned = warning_at (loc, OPT_Walloc_size_larger_than_,
2361 : "argument %i value %qE exceeds "
2362 : "maximum object size %E",
2363 84 : idx[i] + 1, args[i], maxobjsize);
2364 : }
2365 : }
2366 37121 : else if (TREE_CODE (args[i]) == SSA_NAME
2367 37121 : && get_size_range (args[i], argrange[i]))
2368 : {
2369 : /* Verify that the argument's range is not negative (including
2370 : upper bound of zero). */
2371 37108 : if (tree_int_cst_lt (argrange[i][0], integer_zero_node)
2372 37108 : && tree_int_cst_le (argrange[i][1], integer_zero_node))
2373 : {
2374 31 : warned = warning_at (loc, OPT_Walloc_size_larger_than_,
2375 : "argument %i range [%E, %E] is negative",
2376 31 : idx[i] + 1,
2377 : argrange[i][0], argrange[i][1]);
2378 : }
2379 37077 : else if (tree_int_cst_lt (maxobjsize, argrange[i][0]))
2380 : {
2381 33 : warned = warning_at (loc, OPT_Walloc_size_larger_than_,
2382 : "argument %i range [%E, %E] exceeds "
2383 : "maximum object size %E",
2384 33 : idx[i] + 1,
2385 : argrange[i][0], argrange[i][1],
2386 : maxobjsize);
2387 : }
2388 : }
2389 : }
2390 :
2391 74326 : if (!argrange[0][0])
2392 10 : return;
2393 :
2394 : /* For a two-argument alloc_size, validate the product of the two
2395 : arguments if both of their values or ranges are known. */
2396 74093 : if (!warned && tree_fits_uhwi_p (argrange[0][0])
2397 74060 : && argrange[1][0] && tree_fits_uhwi_p (argrange[1][0])
2398 1183 : && !integer_onep (argrange[0][0])
2399 75162 : && !integer_onep (argrange[1][0]))
2400 : {
2401 : /* Check for overflow in the product of a function decorated with
2402 : attribute alloc_size (X, Y). */
2403 445 : unsigned szprec = TYPE_PRECISION (size_type_node);
2404 445 : wide_int x = wi::to_wide (argrange[0][0], szprec);
2405 445 : wide_int y = wi::to_wide (argrange[1][0], szprec);
2406 :
2407 445 : wi::overflow_type vflow;
2408 445 : wide_int prod = wi::umul (x, y, &vflow);
2409 :
2410 445 : if (vflow)
2411 4 : warned = warning_at (loc, OPT_Walloc_size_larger_than_,
2412 : "product %<%E * %E%> of arguments %i and %i "
2413 : "exceeds %<SIZE_MAX%>",
2414 : argrange[0][0], argrange[1][0],
2415 4 : idx[0] + 1, idx[1] + 1);
2416 441 : else if (wi::ltu_p (wi::to_wide (maxobjsize, szprec), prod))
2417 14 : warned = warning_at (loc, OPT_Walloc_size_larger_than_,
2418 : "product %<%E * %E%> of arguments %i and %i "
2419 : "exceeds maximum object size %E",
2420 : argrange[0][0], argrange[1][0],
2421 14 : idx[0] + 1, idx[1] + 1,
2422 : maxobjsize);
2423 :
2424 445 : if (warned)
2425 : {
2426 : /* Print the full range of each of the two arguments to make
2427 : it clear when it is, in fact, in a range and not constant. */
2428 16 : if (argrange[0][0] != argrange [0][1])
2429 1 : inform (loc, "argument %i in the range [%E, %E]",
2430 1 : idx[0] + 1, argrange[0][0], argrange[0][1]);
2431 16 : if (argrange[1][0] != argrange [1][1])
2432 1 : inform (loc, "argument %i in the range [%E, %E]",
2433 1 : idx[1] + 1, argrange[1][0], argrange[1][1]);
2434 : }
2435 445 : }
2436 :
2437 74316 : if (warned && fn)
2438 : {
2439 214 : location_t fnloc = DECL_SOURCE_LOCATION (fn);
2440 :
2441 214 : if (DECL_IS_UNDECLARED_BUILTIN (fn))
2442 64 : inform (loc,
2443 : "in a call to built-in allocation function %qD", fn);
2444 : else
2445 150 : inform (fnloc,
2446 : "in a call to allocation function %qD declared here", fn);
2447 : }
2448 : }
2449 :
2450 : /* Check a call to an alloca function for an excessive size. */
2451 :
2452 : void
2453 31277 : pass_waccess::check_alloca (gcall *stmt)
2454 : {
2455 31277 : if (m_early_checks_p)
2456 : return;
2457 :
2458 14526 : if ((warn_vla_limit >= HOST_WIDE_INT_MAX
2459 14499 : && warn_alloc_size_limit < warn_vla_limit)
2460 14516 : || (warn_alloca_limit >= HOST_WIDE_INT_MAX
2461 14453 : && warn_alloc_size_limit < warn_alloca_limit))
2462 : {
2463 : /* -Walloca-larger-than and -Wvla-larger-than settings of less
2464 : than HWI_MAX override the more general -Walloc-size-larger-than
2465 : so unless either of the former options is smaller than the last
2466 : one (which would imply that the call was already checked), check
2467 : the alloca arguments for overflow. */
2468 10 : const tree alloc_args[] = { call_arg (stmt, 0), NULL_TREE };
2469 10 : const int idx[] = { 0, -1 };
2470 10 : maybe_warn_alloc_args_overflow (stmt, alloc_args, idx);
2471 : }
2472 : }
2473 :
2474 : /* Check a call to an allocation function for an excessive size. */
2475 :
2476 : void
2477 2967763 : pass_waccess::check_alloc_size_call (gcall *stmt)
2478 : {
2479 2967763 : if (m_early_checks_p)
2480 2893447 : return;
2481 :
2482 1418088 : if (gimple_call_num_args (stmt) < 1)
2483 : /* Avoid invalid calls to functions without a prototype. */
2484 : return;
2485 :
2486 1181043 : tree fndecl = gimple_call_fndecl (stmt);
2487 1181043 : if (fndecl && gimple_call_builtin_p (stmt, BUILT_IN_NORMAL))
2488 : {
2489 : /* Alloca is handled separately. */
2490 566976 : switch (DECL_FUNCTION_CODE (fndecl))
2491 : {
2492 : case BUILT_IN_ALLOCA:
2493 : case BUILT_IN_ALLOCA_WITH_ALIGN:
2494 : case BUILT_IN_ALLOCA_WITH_ALIGN_AND_MAX:
2495 : return;
2496 : default:
2497 : break;
2498 : }
2499 : }
2500 :
2501 1171868 : tree fntype = gimple_call_fntype (stmt);
2502 1171868 : tree fntypeattrs = TYPE_ATTRIBUTES (fntype);
2503 :
2504 1171868 : tree alloc_size = lookup_attribute ("alloc_size", fntypeattrs);
2505 1171868 : if (!alloc_size)
2506 : return;
2507 :
2508 : /* Extract attribute alloc_size from the type of the called expression
2509 : (which could be a function or a function pointer) and if set, store
2510 : the indices of the corresponding arguments in ALLOC_IDX, and then
2511 : the actual argument(s) at those indices in ALLOC_ARGS. */
2512 74321 : int idx[2] = { -1, -1 };
2513 74321 : tree alloc_args[] = { NULL_TREE, NULL_TREE };
2514 74321 : unsigned nargs = gimple_call_num_args (stmt);
2515 :
2516 74321 : tree args = TREE_VALUE (alloc_size);
2517 74321 : idx[0] = TREE_INT_CST_LOW (TREE_VALUE (args)) - 1;
2518 : /* Avoid invalid calls to functions without a prototype. */
2519 74321 : if ((unsigned) idx[0] >= nargs)
2520 : return;
2521 74316 : alloc_args[0] = call_arg (stmt, idx[0]);
2522 74316 : if (TREE_CHAIN (args))
2523 : {
2524 1283 : idx[1] = TREE_INT_CST_LOW (TREE_VALUE (TREE_CHAIN (args))) - 1;
2525 1283 : if ((unsigned) idx[1] >= nargs)
2526 : return;
2527 1283 : alloc_args[1] = call_arg (stmt, idx[1]);
2528 : }
2529 :
2530 74316 : maybe_warn_alloc_args_overflow (stmt, alloc_args, idx);
2531 : }
2532 :
2533 : /* Check a call STMT to strcat() for overflow and warn if it does. */
2534 :
2535 : void
2536 1657 : pass_waccess::check_strcat (gcall *stmt)
2537 : {
2538 1657 : if (m_early_checks_p)
2539 938 : return;
2540 :
2541 719 : if (!warn_stringop_overflow && !warn_stringop_overread)
2542 : return;
2543 :
2544 719 : tree dest = call_arg (stmt, 0);
2545 719 : tree src = call_arg (stmt, 1);
2546 :
2547 : /* There is no way here to determine the length of the string in
2548 : the destination to which the SRC string is being appended so
2549 : just diagnose cases when the source string is longer than
2550 : the destination object. */
2551 719 : access_data data (m_ptr_qry.rvals, stmt, access_read_write, NULL_TREE,
2552 719 : true, NULL_TREE, true);
2553 719 : const int ost = warn_stringop_overflow ? warn_stringop_overflow - 1 : 1;
2554 719 : compute_objsize (src, stmt, ost, &data.src, &m_ptr_qry);
2555 719 : tree destsize = compute_objsize (dest, stmt, ost, &data.dst, &m_ptr_qry);
2556 :
2557 719 : check_access (stmt, /*dstwrite=*/NULL_TREE, /*maxread=*/NULL_TREE,
2558 : src, destsize, data.mode, &data, m_ptr_qry.rvals);
2559 : }
2560 :
2561 : /* Check a call STMT to strcat() for overflow and warn if it does. */
2562 :
2563 : void
2564 1667 : pass_waccess::check_strncat (gcall *stmt)
2565 : {
2566 1667 : if (m_early_checks_p)
2567 867 : return;
2568 :
2569 842 : if (!warn_stringop_overflow && !warn_stringop_overread)
2570 : return;
2571 :
2572 823 : tree dest = call_arg (stmt, 0);
2573 823 : tree src = call_arg (stmt, 1);
2574 : /* The upper bound on the number of bytes to write. */
2575 823 : tree maxread = call_arg (stmt, 2);
2576 :
2577 : /* Detect unterminated source (only). */
2578 823 : if (!check_nul_terminated_array (stmt, src, maxread))
2579 : return;
2580 :
2581 : /* The length of the source sequence. */
2582 817 : tree slen = c_strlen (src, 1);
2583 :
2584 : /* Try to determine the range of lengths that the source expression
2585 : refers to. Since the lengths are only used for warning and not
2586 : for code generation disable strict mode below. */
2587 817 : tree maxlen = slen;
2588 817 : if (!maxlen)
2589 : {
2590 710 : c_strlen_data lendata = { };
2591 710 : get_range_strlen (src, &lendata, /* eltsize = */ 1);
2592 710 : maxlen = lendata.maxbound;
2593 : }
2594 :
2595 817 : access_data data (m_ptr_qry.rvals, stmt, access_read_write);
2596 : /* Try to verify that the destination is big enough for the shortest
2597 : string. First try to determine the size of the destination object
2598 : into which the source is being copied. */
2599 817 : const int ost = warn_stringop_overflow - 1;
2600 817 : tree destsize = compute_objsize (dest, stmt, ost, &data.dst, &m_ptr_qry);
2601 :
2602 : /* Add one for the terminating nul. */
2603 817 : tree srclen = (maxlen
2604 817 : ? fold_build2 (PLUS_EXPR, size_type_node, maxlen,
2605 : size_one_node)
2606 : : NULL_TREE);
2607 :
2608 : /* The strncat function copies at most MAXREAD bytes and always appends
2609 : the terminating nul so the specified upper bound should never be equal
2610 : to (or greater than) the size of the destination. */
2611 324 : if (tree_fits_uhwi_p (maxread) && tree_fits_uhwi_p (destsize)
2612 1141 : && tree_int_cst_equal (destsize, maxread))
2613 : {
2614 17 : location_t loc = get_location (stmt);
2615 17 : rich_location_with_details richloc (loc, stmt);
2616 :
2617 17 : warning_at (&richloc, OPT_Wstringop_overflow_,
2618 : "%qD specified bound %E equals destination size",
2619 : get_callee_fndecl (stmt), maxread);
2620 :
2621 17 : return;
2622 17 : }
2623 :
2624 800 : if (!srclen
2625 800 : || (maxread && tree_fits_uhwi_p (maxread)
2626 237 : && tree_fits_uhwi_p (srclen)
2627 237 : && tree_int_cst_lt (maxread, srclen)))
2628 : srclen = maxread;
2629 :
2630 800 : check_access (stmt, /*dstwrite=*/NULL_TREE, maxread, srclen,
2631 : destsize, data.mode, &data, m_ptr_qry.rvals);
2632 : }
2633 :
2634 : /* Check a call STMT to stpcpy() or strcpy() for overflow and warn
2635 : if it does. */
2636 :
2637 : void
2638 7225 : pass_waccess::check_stxcpy (gcall *stmt)
2639 : {
2640 7225 : if (m_early_checks_p)
2641 4399 : return;
2642 :
2643 2968 : tree dst = call_arg (stmt, 0);
2644 2968 : tree src = call_arg (stmt, 1);
2645 :
2646 2968 : tree size;
2647 2968 : bool exact;
2648 2968 : if (tree nonstr = unterminated_array (src, &size, &exact))
2649 : {
2650 : /* NONSTR refers to the non-nul terminated constant array. */
2651 142 : warn_string_no_nul (get_location (stmt), stmt, NULL, src, nonstr,
2652 : size, exact);
2653 142 : return;
2654 : }
2655 :
2656 2826 : if (warn_stringop_overflow)
2657 : {
2658 2621 : access_data data (m_ptr_qry.rvals, stmt, access_read_write, NULL_TREE,
2659 2621 : true, NULL_TREE, true);
2660 2621 : const int ost = warn_stringop_overflow ? warn_stringop_overflow - 1 : 1;
2661 2621 : compute_objsize (src, stmt, ost, &data.src, &m_ptr_qry);
2662 2621 : tree dstsize = compute_objsize (dst, stmt, ost, &data.dst, &m_ptr_qry);
2663 2621 : check_access (stmt, /*dstwrite=*/ NULL_TREE,
2664 : /*maxread=*/ NULL_TREE, /*srcstr=*/ src,
2665 : dstsize, data.mode, &data, m_ptr_qry.rvals);
2666 : }
2667 :
2668 : /* Check to see if the argument was declared attribute nonstring
2669 : and if so, issue a warning since at this point it's not known
2670 : to be nul-terminated. */
2671 2826 : tree fndecl = get_callee_fndecl (stmt);
2672 2826 : maybe_warn_nonstring_arg (fndecl, stmt);
2673 : }
2674 :
2675 : /* Check a call STMT to stpncpy() or strncpy() for overflow and warn
2676 : if it does. */
2677 :
2678 : void
2679 5890 : pass_waccess::check_stxncpy (gcall *stmt)
2680 : {
2681 5890 : if (m_early_checks_p || !warn_stringop_overflow)
2682 3304 : return;
2683 :
2684 2586 : tree dst = call_arg (stmt, 0);
2685 2586 : tree src = call_arg (stmt, 1);
2686 : /* The number of bytes to write (not the maximum). */
2687 2586 : tree len = call_arg (stmt, 2);
2688 :
2689 2586 : access_data data (m_ptr_qry.rvals, stmt, access_read_write, len, true, len,
2690 2586 : true);
2691 2586 : const int ost = warn_stringop_overflow ? warn_stringop_overflow - 1 : 1;
2692 2586 : compute_objsize (src, stmt, ost, &data.src, &m_ptr_qry);
2693 2586 : tree dstsize = compute_objsize (dst, stmt, ost, &data.dst, &m_ptr_qry);
2694 :
2695 2586 : check_access (stmt, /*dstwrite=*/len, /*maxread=*/len, src, dstsize,
2696 : data.mode, &data, m_ptr_qry.rvals);
2697 : }
2698 :
2699 : /* Check a call STMT to stpncpy() or strncpy() for overflow and warn
2700 : if it does. */
2701 :
2702 : void
2703 6070 : pass_waccess::check_strncmp (gcall *stmt)
2704 : {
2705 6070 : if (m_early_checks_p || !warn_stringop_overread)
2706 3974 : return;
2707 :
2708 2844 : tree arg1 = call_arg (stmt, 0);
2709 2844 : tree arg2 = call_arg (stmt, 1);
2710 2844 : tree bound = call_arg (stmt, 2);
2711 :
2712 : /* First check each argument separately, considering the bound. */
2713 2844 : if (!check_nul_terminated_array (stmt, arg1, bound)
2714 2844 : || !check_nul_terminated_array (stmt, arg2, bound))
2715 6 : return;
2716 :
2717 : /* A strncmp read from each argument is constrained not just by
2718 : the bound but also by the length of the shorter string. Specifying
2719 : a bound that's larger than the size of either array makes no sense
2720 : and is likely a bug. When the length of neither of the two strings
2721 : is known but the sizes of both of the arrays they are stored in is,
2722 : issue a warning if the bound is larger than the size of
2723 : the larger of the two arrays. */
2724 :
2725 2838 : c_strlen_data lendata1{ }, lendata2{ };
2726 2838 : tree len1 = c_strlen (arg1, 1, &lendata1);
2727 2838 : tree len2 = c_strlen (arg2, 1, &lendata2);
2728 :
2729 2838 : if (len1 && TREE_CODE (len1) != INTEGER_CST)
2730 2571 : len1 = NULL_TREE;
2731 2838 : if (len2 && TREE_CODE (len2) != INTEGER_CST)
2732 1563 : len2 = NULL_TREE;
2733 :
2734 2838 : if (len1 && len2)
2735 : /* If the length of both arguments was computed they must both be
2736 : nul-terminated and no further checking is necessary regardless
2737 : of the bound. */
2738 : return;
2739 :
2740 : /* Check to see if the argument was declared with attribute nonstring
2741 : and if so, issue a warning since at this point it's not known to be
2742 : nul-terminated. */
2743 2721 : if (maybe_warn_nonstring_arg (get_callee_fndecl (stmt), stmt))
2744 : return;
2745 :
2746 2548 : access_data adata1 (m_ptr_qry.rvals, stmt, access_read_only, NULL_TREE, false,
2747 2548 : bound, true);
2748 2548 : access_data adata2 (m_ptr_qry.rvals, stmt, access_read_only, NULL_TREE, false,
2749 2548 : bound, true);
2750 :
2751 : /* Determine the range of the bound first and bail if it fails; it's
2752 : cheaper than computing the size of the objects. */
2753 2548 : tree bndrng[2] = { NULL_TREE, NULL_TREE };
2754 2548 : get_size_range (m_ptr_qry.rvals, bound, stmt, bndrng, 0, adata1.src_bndrng);
2755 2548 : if (!bndrng[0] || integer_zerop (bndrng[0]))
2756 452 : return;
2757 :
2758 2096 : if (len1 && tree_int_cst_lt (len1, bndrng[0]))
2759 20 : bndrng[0] = len1;
2760 2096 : if (len2 && tree_int_cst_lt (len2, bndrng[0]))
2761 54 : bndrng[0] = len2;
2762 :
2763 : /* compute_objsize almost never fails (and ultimately should never
2764 : fail). Don't bother to handle the rare case when it does. */
2765 2096 : if (!compute_objsize (arg1, stmt, 1, &adata1.src, &m_ptr_qry)
2766 2096 : || !compute_objsize (arg2, stmt, 1, &adata2.src, &m_ptr_qry))
2767 0 : return;
2768 :
2769 : /* Compute the size of the remaining space in each array after
2770 : subtracting any offset into it. */
2771 2096 : offset_int rem1 = adata1.src.size_remaining ();
2772 2096 : offset_int rem2 = adata2.src.size_remaining ();
2773 :
2774 : /* Cap REM1 and REM2 at the other if the other's argument is known
2775 : to be an unterminated array, either because there's no space
2776 : left in it after adding its offset or because it's constant and
2777 : has no nul. */
2778 4189 : if (rem1 == 0 || (rem1 < rem2 && lendata1.decl))
2779 5 : rem2 = rem1;
2780 4181 : else if (rem2 == 0 || (rem2 < rem1 && lendata2.decl))
2781 3 : rem1 = rem2;
2782 :
2783 : /* Point PAD at the array to reference in the note if a warning
2784 : is issued. */
2785 2096 : access_data *pad = len1 ? &adata2 : &adata1;
2786 2096 : offset_int maxrem = wi::max (rem1, rem2, UNSIGNED);
2787 2094 : if (lendata1.decl || lendata2.decl
2788 4188 : || maxrem < wi::to_offset (bndrng[0]))
2789 : {
2790 : /* Warn when either argument isn't nul-terminated or the maximum
2791 : remaining space in the two arrays is less than the bound. */
2792 21 : tree func = get_callee_fndecl (stmt);
2793 21 : location_t loc = gimple_location (stmt);
2794 42 : maybe_warn_for_bound (OPT_Wstringop_overread, loc, stmt, func,
2795 42 : bndrng, wide_int_to_tree (sizetype, maxrem),
2796 : pad);
2797 : }
2798 : }
2799 :
2800 : /* Determine and check the sizes of the source and the destination
2801 : of calls to __builtin_{bzero,memcpy,mempcpy,memset} calls. STMT is
2802 : the call statement, DEST is the destination argument, SRC is the source
2803 : argument or null, and SIZE is the number of bytes being accessed. Use
2804 : Object Size type-0 regardless of the OPT_Wstringop_overflow_ setting.
2805 : Return true on success (no overflow or invalid sizes), false otherwise. */
2806 :
2807 : void
2808 627977 : pass_waccess::check_memop_access (gimple *stmt, tree dest, tree src, tree size)
2809 : {
2810 627977 : if (m_early_checks_p)
2811 279374 : return;
2812 :
2813 : /* For functions like memset and memcpy that operate on raw memory
2814 : try to determine the size of the largest source and destination
2815 : object using type-0 Object Size regardless of the object size
2816 : type specified by the option. */
2817 348603 : access_data data (m_ptr_qry.rvals, stmt, access_read_write);
2818 348603 : tree srcsize
2819 348603 : = src ? compute_objsize (src, stmt, 0, &data.src, &m_ptr_qry) : NULL_TREE;
2820 348603 : tree dstsize = compute_objsize (dest, stmt, 0, &data.dst, &m_ptr_qry);
2821 :
2822 348603 : check_access (stmt, size, /*maxread=*/NULL_TREE, srcsize, dstsize,
2823 : data.mode, &data, m_ptr_qry.rvals);
2824 : }
2825 :
2826 : /* A convenience wrapper for check_access to check access by a read-only
2827 : function like puts or strcmp. */
2828 :
2829 : void
2830 843345 : pass_waccess::check_read_access (gimple *stmt, tree src,
2831 : tree bound /* = NULL_TREE */,
2832 : int ost /* = 1 */)
2833 : {
2834 843345 : if (m_early_checks_p || !warn_stringop_overread)
2835 521154 : return;
2836 :
2837 322191 : if (bound && !useless_type_conversion_p (size_type_node, TREE_TYPE (bound)))
2838 0 : bound = fold_convert (size_type_node, bound);
2839 :
2840 322191 : tree fndecl = get_callee_fndecl (stmt);
2841 322191 : maybe_warn_nonstring_arg (fndecl, stmt);
2842 :
2843 322191 : access_data data (m_ptr_qry.rvals, stmt, access_read_only, NULL_TREE,
2844 322191 : false, bound, true);
2845 322191 : compute_objsize (src, stmt, ost, &data.src, &m_ptr_qry);
2846 322191 : check_access (stmt, /*dstwrite=*/ NULL_TREE, /*maxread=*/ bound,
2847 : /*srcstr=*/ src, /*dstsize=*/ NULL_TREE, data.mode,
2848 : &data, m_ptr_qry.rvals);
2849 : }
2850 :
2851 : /* Return true if memory model ORD is constant in the context of STMT and
2852 : set *CSTVAL to the constant value. Otherwise return false. Warn for
2853 : invalid ORD. */
2854 :
2855 : bool
2856 242239 : memmodel_to_uhwi (tree ord, gimple *stmt, unsigned HOST_WIDE_INT *cstval)
2857 : {
2858 242239 : unsigned HOST_WIDE_INT val;
2859 :
2860 242239 : if (TREE_CODE (ord) == INTEGER_CST)
2861 : {
2862 239485 : if (!tree_fits_uhwi_p (ord))
2863 : return false;
2864 239477 : val = tree_to_uhwi (ord);
2865 : }
2866 : else
2867 : {
2868 : /* Use the range query to determine constant values in the absence
2869 : of constant propagation (such as at -O0). */
2870 2754 : int_range_max rng (TREE_TYPE (ord));
2871 5508 : if (!get_range_query (cfun)->range_of_expr (rng, ord, stmt)
2872 2754 : || !rng.singleton_p (&ord))
2873 2304 : return false;
2874 :
2875 450 : wide_int lob = rng.lower_bound ();
2876 450 : if (!wi::fits_uhwi_p (lob))
2877 0 : return false;
2878 :
2879 450 : val = lob.to_shwi ();
2880 2754 : }
2881 :
2882 239927 : if (targetm.memmodel_check)
2883 : /* This might warn for an invalid VAL but return a conservatively
2884 : valid result. */
2885 239927 : val = targetm.memmodel_check (val);
2886 0 : else if (val & ~MEMMODEL_MASK)
2887 : {
2888 0 : tree fndecl = gimple_call_fndecl (stmt);
2889 0 : location_t loc = gimple_location (stmt);
2890 0 : loc = expansion_point_location_if_in_system_header (loc);
2891 :
2892 0 : warning_at (loc, OPT_Winvalid_memory_model,
2893 : "unknown architecture specifier in memory model "
2894 : "%wi for %qD", val, fndecl);
2895 0 : return false;
2896 : }
2897 :
2898 239927 : *cstval = val;
2899 :
2900 239927 : return true;
2901 : }
2902 :
2903 : /* Valid memory model for each set of atomic built-in functions. */
2904 :
2905 : struct memmodel_pair
2906 : {
2907 : memmodel modval;
2908 : const char* modname;
2909 :
2910 : #define MEMMODEL_PAIR(val, str) \
2911 : { MEMMODEL_ ## val, "memory_order_" str }
2912 : };
2913 :
2914 : /* Valid memory models in the order of increasing strength. */
2915 :
2916 : static const memmodel_pair memory_models[] =
2917 : { MEMMODEL_PAIR (RELAXED, "relaxed"),
2918 : MEMMODEL_PAIR (SEQ_CST, "seq_cst"),
2919 : MEMMODEL_PAIR (ACQUIRE, "acquire"),
2920 : MEMMODEL_PAIR (CONSUME, "consume"),
2921 : MEMMODEL_PAIR (RELEASE, "release"),
2922 : MEMMODEL_PAIR (ACQ_REL, "acq_rel")
2923 : };
2924 :
2925 : /* Return the name of the memory model VAL. */
2926 :
2927 : static const char*
2928 230 : memmodel_name (unsigned HOST_WIDE_INT val)
2929 : {
2930 230 : val = memmodel_base (val);
2931 :
2932 988 : for (unsigned i = 0; i != ARRAY_SIZE (memory_models); ++i)
2933 : {
2934 971 : if (val == memory_models[i].modval)
2935 213 : return memory_models[i].modname;
2936 : }
2937 : return NULL;
2938 : }
2939 :
2940 : /* Indices of valid MEMORY_MODELS above for corresponding atomic operations. */
2941 : static const unsigned char load_models[] = { 0, 1, 2, 3, UCHAR_MAX };
2942 : static const unsigned char store_models[] = { 0, 1, 4, UCHAR_MAX };
2943 : static const unsigned char xchg_models[] = { 0, 1, 3, 4, 5, UCHAR_MAX };
2944 : static const unsigned char flag_clr_models[] = { 0, 1, 4, UCHAR_MAX };
2945 : static const unsigned char all_models[] = { 0, 1, 2, 3, 4, 5, UCHAR_MAX };
2946 :
2947 : /* Check the success memory model argument ORD_SUCS to the call STMT to
2948 : an atomic function and warn if it's invalid. If nonnull, also check
2949 : the failure memory model ORD_FAIL and warn if it's invalid. Return
2950 : true if a warning has been issued. */
2951 :
2952 : bool
2953 219684 : pass_waccess::maybe_warn_memmodel (gimple *stmt, tree ord_sucs,
2954 : tree ord_fail, const unsigned char *valid)
2955 : {
2956 219684 : unsigned HOST_WIDE_INT sucs, fail = 0;
2957 219684 : if (!memmodel_to_uhwi (ord_sucs, stmt, &sucs)
2958 219684 : || (ord_fail && !memmodel_to_uhwi (ord_fail, stmt, &fail)))
2959 2312 : return false;
2960 :
2961 217372 : bool is_valid = false;
2962 217372 : if (valid)
2963 457734 : for (unsigned i = 0; valid[i] != UCHAR_MAX; ++i)
2964 : {
2965 457652 : memmodel model = memory_models[valid[i]].modval;
2966 457652 : if (memmodel_base (sucs) == model)
2967 : {
2968 : is_valid = true;
2969 : break;
2970 : }
2971 : }
2972 : else
2973 : is_valid = true;
2974 :
2975 217372 : tree fndecl = gimple_call_fndecl (stmt);
2976 217372 : location_t loc = gimple_location (stmt);
2977 217372 : loc = expansion_point_location_if_in_system_header (loc);
2978 :
2979 217372 : if (!is_valid)
2980 : {
2981 82 : bool warned = false;
2982 82 : auto_diagnostic_group d;
2983 82 : if (const char *modname = memmodel_name (sucs))
2984 65 : warned = warning_at (loc, OPT_Winvalid_memory_model,
2985 : "invalid memory model %qs for %qD",
2986 : modname, fndecl);
2987 : else
2988 17 : warned = warning_at (loc, OPT_Winvalid_memory_model,
2989 : "invalid memory model %wi for %qD",
2990 : sucs, fndecl);
2991 :
2992 82 : if (!warned)
2993 : return false;
2994 :
2995 : /* Print a note with the valid memory models. */
2996 82 : auto_vec<const char *> strings;
2997 401 : for (unsigned i = 0; valid[i] != UCHAR_MAX; ++i)
2998 : {
2999 319 : const char *modname = memory_models[valid[i]].modname;
3000 319 : strings.safe_push (modname);
3001 : }
3002 82 : pp_markup::comma_separated_quoted_strings e (strings);
3003 82 : inform (loc, "valid models are %e", &e);
3004 82 : return true;
3005 82 : }
3006 :
3007 217290 : if (!ord_fail)
3008 : return false;
3009 :
3010 22543 : if (fail == MEMMODEL_RELEASE || fail == MEMMODEL_ACQ_REL)
3011 60 : if (const char *failname = memmodel_name (fail))
3012 : {
3013 : /* If both memory model arguments are valid but their combination
3014 : is not, use their names in the warning. */
3015 60 : auto_diagnostic_group d;
3016 60 : if (!warning_at (loc, OPT_Winvalid_memory_model,
3017 : "invalid failure memory model %qs for %qD",
3018 : failname, fndecl))
3019 : return false;
3020 :
3021 60 : inform (loc,
3022 : "valid failure models are %qs, %qs, %qs, %qs",
3023 : "memory_order_relaxed", "memory_order_seq_cst",
3024 : "memory_order_acquire", "memory_order_consume");
3025 60 : return true;
3026 60 : }
3027 :
3028 22483 : if (memmodel_base (fail) <= memmodel_base (sucs))
3029 : return false;
3030 :
3031 44 : if (const char *sucsname = memmodel_name (sucs))
3032 44 : if (const char *failname = memmodel_name (fail))
3033 : {
3034 : /* If both memory model arguments are valid but their combination
3035 : is not, use their names in the warning. */
3036 44 : auto_diagnostic_group d;
3037 44 : if (!warning_at (loc, OPT_Winvalid_memory_model,
3038 : "failure memory model %qs cannot be stronger "
3039 : "than success memory model %qs for %qD",
3040 : failname, sucsname, fndecl))
3041 : return false;
3042 :
3043 : /* Print a note with the valid failure memory models which are
3044 : those with a value less than or equal to the success mode. */
3045 44 : auto_vec<const char *> strings;
3046 88 : for (unsigned i = 0;
3047 88 : memory_models[i].modval <= memmodel_base (sucs); ++i)
3048 : {
3049 44 : const char *modname = memory_models[valid[i]].modname;
3050 44 : strings.safe_push (modname);
3051 : }
3052 44 : pp_markup::comma_separated_quoted_strings e (strings);
3053 :
3054 44 : inform (loc, "valid models are %e", &e);
3055 44 : return true;
3056 44 : }
3057 :
3058 : /* If either memory model argument value is invalid use the numerical
3059 : value of both in the message. */
3060 0 : return warning_at (loc, OPT_Winvalid_memory_model,
3061 : "failure memory model %wi cannot be stronger "
3062 : "than success memory model %wi for %qD",
3063 : fail, sucs, fndecl);
3064 : }
3065 :
3066 : /* Wrapper for the above. */
3067 :
3068 : void
3069 219711 : pass_waccess::check_atomic_memmodel (gimple *stmt, tree ord_sucs,
3070 : tree ord_fail, const unsigned char *valid)
3071 : {
3072 219711 : if (warning_suppressed_p (stmt, OPT_Winvalid_memory_model))
3073 : return;
3074 :
3075 219684 : if (!maybe_warn_memmodel (stmt, ord_sucs, ord_fail, valid))
3076 : return;
3077 :
3078 186 : suppress_warning (stmt, OPT_Winvalid_memory_model);
3079 : }
3080 :
3081 : /* Check a call STMT to an atomic or sync built-in. */
3082 :
3083 : bool
3084 2539067 : pass_waccess::check_atomic_builtin (gcall *stmt)
3085 : {
3086 2539067 : tree callee = gimple_call_fndecl (stmt);
3087 2539067 : if (!callee)
3088 : return false;
3089 :
3090 : /* The size in bytes of the access by the function, and the number
3091 : of the second argument to check (if any). */
3092 2539067 : unsigned bytes = 0, arg2 = UINT_MAX;
3093 2539067 : unsigned sucs_arg = UINT_MAX, fail_arg = UINT_MAX;
3094 : /* Points to the array of indices of valid memory models. */
3095 2539067 : const unsigned char *pvalid_models = NULL;
3096 :
3097 2539067 : switch (DECL_FUNCTION_CODE (callee))
3098 : {
3099 : #define BUILTIN_ACCESS_SIZE_FNSPEC(N) \
3100 : BUILT_IN_SYNC_FETCH_AND_ADD_ ## N: \
3101 : case BUILT_IN_SYNC_FETCH_AND_SUB_ ## N: \
3102 : case BUILT_IN_SYNC_FETCH_AND_OR_ ## N: \
3103 : case BUILT_IN_SYNC_FETCH_AND_AND_ ## N: \
3104 : case BUILT_IN_SYNC_FETCH_AND_XOR_ ## N: \
3105 : case BUILT_IN_SYNC_FETCH_AND_NAND_ ## N: \
3106 : case BUILT_IN_SYNC_ADD_AND_FETCH_ ## N: \
3107 : case BUILT_IN_SYNC_SUB_AND_FETCH_ ## N: \
3108 : case BUILT_IN_SYNC_OR_AND_FETCH_ ## N: \
3109 : case BUILT_IN_SYNC_AND_AND_FETCH_ ## N: \
3110 : case BUILT_IN_SYNC_XOR_AND_FETCH_ ## N: \
3111 : case BUILT_IN_SYNC_NAND_AND_FETCH_ ## N: \
3112 : case BUILT_IN_SYNC_LOCK_TEST_AND_SET_ ## N: \
3113 : case BUILT_IN_SYNC_BOOL_COMPARE_AND_SWAP_ ## N: \
3114 : case BUILT_IN_SYNC_VAL_COMPARE_AND_SWAP_ ## N: \
3115 : case BUILT_IN_SYNC_LOCK_RELEASE_ ## N: \
3116 : bytes = N; \
3117 : break; \
3118 : case BUILT_IN_ATOMIC_LOAD_ ## N: \
3119 : pvalid_models = load_models; \
3120 : sucs_arg = 1; \
3121 : /* FALLTHROUGH */ \
3122 : case BUILT_IN_ATOMIC_STORE_ ## N: \
3123 : if (!pvalid_models) \
3124 : pvalid_models = store_models; \
3125 : /* FALLTHROUGH */ \
3126 : case BUILT_IN_ATOMIC_ADD_FETCH_ ## N: \
3127 : case BUILT_IN_ATOMIC_SUB_FETCH_ ## N: \
3128 : case BUILT_IN_ATOMIC_AND_FETCH_ ## N: \
3129 : case BUILT_IN_ATOMIC_NAND_FETCH_ ## N: \
3130 : case BUILT_IN_ATOMIC_XOR_FETCH_ ## N: \
3131 : case BUILT_IN_ATOMIC_OR_FETCH_ ## N: \
3132 : case BUILT_IN_ATOMIC_FETCH_ADD_ ## N: \
3133 : case BUILT_IN_ATOMIC_FETCH_SUB_ ## N: \
3134 : case BUILT_IN_ATOMIC_FETCH_AND_ ## N: \
3135 : case BUILT_IN_ATOMIC_FETCH_NAND_ ## N: \
3136 : case BUILT_IN_ATOMIC_FETCH_OR_ ## N: \
3137 : case BUILT_IN_ATOMIC_FETCH_XOR_ ## N: \
3138 : bytes = N; \
3139 : if (sucs_arg == UINT_MAX) \
3140 : sucs_arg = 2; \
3141 : if (!pvalid_models) \
3142 : pvalid_models = all_models; \
3143 : break; \
3144 : case BUILT_IN_ATOMIC_EXCHANGE_ ## N: \
3145 : bytes = N; \
3146 : sucs_arg = 3; \
3147 : pvalid_models = xchg_models; \
3148 : break; \
3149 : case BUILT_IN_ATOMIC_COMPARE_EXCHANGE_ ## N: \
3150 : bytes = N; \
3151 : sucs_arg = 4; \
3152 : fail_arg = 5; \
3153 : pvalid_models = all_models; \
3154 : arg2 = 1
3155 :
3156 63300 : case BUILTIN_ACCESS_SIZE_FNSPEC (1);
3157 4820 : break;
3158 17051 : case BUILTIN_ACCESS_SIZE_FNSPEC (2);
3159 1813 : break;
3160 79515 : case BUILTIN_ACCESS_SIZE_FNSPEC (4);
3161 5656 : break;
3162 64784 : case BUILTIN_ACCESS_SIZE_FNSPEC (8);
3163 7212 : break;
3164 15087 : case BUILTIN_ACCESS_SIZE_FNSPEC (16);
3165 3438 : break;
3166 :
3167 104 : case BUILT_IN_ATOMIC_CLEAR:
3168 104 : sucs_arg = 1;
3169 104 : pvalid_models = flag_clr_models;
3170 104 : break;
3171 :
3172 : default:
3173 : return false;
3174 : }
3175 :
3176 233753 : unsigned nargs = gimple_call_num_args (stmt);
3177 233753 : if (sucs_arg < nargs)
3178 : {
3179 219711 : tree ord_sucs = gimple_call_arg (stmt, sucs_arg);
3180 219711 : tree ord_fail = NULL_TREE;
3181 219711 : if (fail_arg < nargs)
3182 22939 : ord_fail = gimple_call_arg (stmt, fail_arg);
3183 219711 : check_atomic_memmodel (stmt, ord_sucs, ord_fail, pvalid_models);
3184 : }
3185 :
3186 233753 : if (!bytes)
3187 : return true;
3188 :
3189 233649 : tree size = build_int_cstu (sizetype, bytes);
3190 233649 : tree dst = gimple_call_arg (stmt, 0);
3191 233649 : check_memop_access (stmt, dst, NULL_TREE, size);
3192 :
3193 233649 : if (arg2 != UINT_MAX)
3194 : {
3195 22939 : tree dst = gimple_call_arg (stmt, arg2);
3196 22939 : check_memop_access (stmt, dst, NULL_TREE, size);
3197 : }
3198 :
3199 : return true;
3200 : }
3201 :
3202 : /* Check call STMT to a built-in function for invalid accesses. Return
3203 : true if a call has been handled. */
3204 :
3205 : bool
3206 3554216 : pass_waccess::check_builtin (gcall *stmt)
3207 : {
3208 3554216 : tree callee = gimple_call_fndecl (stmt);
3209 3554216 : if (!callee)
3210 : return false;
3211 :
3212 3554216 : switch (DECL_FUNCTION_CODE (callee))
3213 : {
3214 31277 : case BUILT_IN_ALLOCA:
3215 31277 : case BUILT_IN_ALLOCA_WITH_ALIGN:
3216 31277 : case BUILT_IN_ALLOCA_WITH_ALIGN_AND_MAX:
3217 31277 : check_alloca (stmt);
3218 31277 : return true;
3219 :
3220 62 : case BUILT_IN_EXECL:
3221 62 : case BUILT_IN_EXECLE:
3222 62 : case BUILT_IN_EXECLP:
3223 62 : case BUILT_IN_EXECV:
3224 62 : case BUILT_IN_EXECVE:
3225 62 : case BUILT_IN_EXECVP:
3226 62 : check_read_access (stmt, call_arg (stmt, 0));
3227 62 : return true;
3228 :
3229 140347 : case BUILT_IN_FREE:
3230 140347 : case BUILT_IN_REALLOC:
3231 140347 : if (!m_early_checks_p)
3232 : {
3233 66168 : tree arg = call_arg (stmt, 0);
3234 66168 : if (TREE_CODE (arg) == SSA_NAME)
3235 66084 : check_pointer_uses (stmt, arg);
3236 : }
3237 : return true;
3238 :
3239 10222 : case BUILT_IN_GETTEXT:
3240 10222 : case BUILT_IN_PUTS:
3241 10222 : case BUILT_IN_PUTS_UNLOCKED:
3242 10222 : case BUILT_IN_STRDUP:
3243 10222 : check_read_access (stmt, call_arg (stmt, 0));
3244 10222 : return true;
3245 :
3246 34357 : case BUILT_IN_INDEX:
3247 34357 : case BUILT_IN_RINDEX:
3248 34357 : case BUILT_IN_STRCHR:
3249 34357 : case BUILT_IN_STRRCHR:
3250 34357 : case BUILT_IN_STRLEN:
3251 34357 : check_read_access (stmt, call_arg (stmt, 0));
3252 34357 : return true;
3253 :
3254 2903 : case BUILT_IN_FPUTS:
3255 2903 : case BUILT_IN_FPUTS_UNLOCKED:
3256 2903 : check_read_access (stmt, call_arg (stmt, 0));
3257 2903 : return true;
3258 :
3259 2201 : case BUILT_IN_STRNDUP:
3260 2201 : case BUILT_IN_STRNLEN:
3261 2201 : {
3262 2201 : tree str = call_arg (stmt, 0);
3263 2201 : tree len = call_arg (stmt, 1);
3264 2201 : check_read_access (stmt, str, len);
3265 2201 : return true;
3266 : }
3267 :
3268 1657 : case BUILT_IN_STRCAT:
3269 1657 : check_strcat (stmt);
3270 1657 : return true;
3271 :
3272 1667 : case BUILT_IN_STRNCAT:
3273 1667 : check_strncat (stmt);
3274 1667 : return true;
3275 :
3276 7225 : case BUILT_IN_STPCPY:
3277 7225 : case BUILT_IN_STRCPY:
3278 7225 : check_stxcpy (stmt);
3279 7225 : return true;
3280 :
3281 5890 : case BUILT_IN_STPNCPY:
3282 5890 : case BUILT_IN_STRNCPY:
3283 5890 : check_stxncpy (stmt);
3284 5890 : return true;
3285 :
3286 259367 : case BUILT_IN_STRCASECMP:
3287 259367 : case BUILT_IN_STRCMP:
3288 259367 : case BUILT_IN_STRPBRK:
3289 259367 : case BUILT_IN_STRSPN:
3290 259367 : case BUILT_IN_STRCSPN:
3291 259367 : case BUILT_IN_STRSTR:
3292 259367 : check_read_access (stmt, call_arg (stmt, 0));
3293 259367 : check_read_access (stmt, call_arg (stmt, 1));
3294 259367 : return true;
3295 :
3296 6070 : case BUILT_IN_STRNCASECMP:
3297 6070 : case BUILT_IN_STRNCMP:
3298 6070 : check_strncmp (stmt);
3299 6070 : return true;
3300 :
3301 134351 : case BUILT_IN_MEMCMP:
3302 134351 : {
3303 134351 : tree a1 = call_arg (stmt, 0);
3304 134351 : tree a2 = call_arg (stmt, 1);
3305 134351 : tree len = call_arg (stmt, 2);
3306 134351 : check_read_access (stmt, a1, len, 0);
3307 134351 : check_read_access (stmt, a2, len, 0);
3308 134351 : return true;
3309 : }
3310 :
3311 191442 : case BUILT_IN_MEMCPY:
3312 191442 : case BUILT_IN_MEMPCPY:
3313 191442 : case BUILT_IN_MEMMOVE:
3314 191442 : {
3315 191442 : tree dst = call_arg (stmt, 0);
3316 191442 : tree src = call_arg (stmt, 1);
3317 191442 : tree len = call_arg (stmt, 2);
3318 191442 : check_memop_access (stmt, dst, src, len);
3319 191442 : return true;
3320 : }
3321 :
3322 6164 : case BUILT_IN_MEMCHR:
3323 6164 : {
3324 6164 : tree src = call_arg (stmt, 0);
3325 6164 : tree len = call_arg (stmt, 2);
3326 6164 : check_read_access (stmt, src, len, 0);
3327 6164 : return true;
3328 : }
3329 :
3330 179947 : case BUILT_IN_MEMSET:
3331 179947 : {
3332 179947 : tree dst = call_arg (stmt, 0);
3333 179947 : tree len = call_arg (stmt, 2);
3334 179947 : check_memop_access (stmt, dst, NULL_TREE, len);
3335 179947 : return true;
3336 : }
3337 :
3338 2539067 : default:
3339 2539067 : if (check_atomic_builtin (stmt))
3340 : return true;
3341 : break;
3342 : }
3343 :
3344 : return false;
3345 : }
3346 :
3347 : /* Returns the type of the argument ARGNO to function with type FNTYPE
3348 : or null when the type cannot be determined or no such argument exists. */
3349 :
3350 : static tree
3351 61677 : fntype_argno_type (tree fntype, unsigned argno)
3352 : {
3353 61677 : if (!prototype_p (fntype))
3354 : return NULL_TREE;
3355 :
3356 61673 : tree argtype;
3357 61673 : function_args_iterator it;
3358 124948 : FOREACH_FUNCTION_ARGS (fntype, argtype, it)
3359 124948 : if (argno-- == 0)
3360 : return argtype;
3361 :
3362 : return NULL_TREE;
3363 : }
3364 :
3365 : /* Helper to append the "human readable" attribute access specification
3366 : described by ACCESS to the array ATTRSTR with size STRSIZE. Used in
3367 : diagnostics. */
3368 :
3369 : static inline void
3370 280 : append_attrname (const std::pair<int, attr_access> &access,
3371 : char *attrstr, size_t strsize)
3372 : {
3373 280 : if (access.second.internal_p)
3374 : return;
3375 :
3376 262 : tree str = access.second.to_external_string ();
3377 262 : gcc_assert (strsize >= (size_t) TREE_STRING_LENGTH (str));
3378 262 : strcpy (attrstr, TREE_STRING_POINTER (str));
3379 : }
3380 :
3381 : /* Iterate over attribute access read-only, read-write, and write-only
3382 : arguments and diagnose past-the-end accesses and related problems
3383 : in the function call EXP. */
3384 :
3385 : void
3386 2967763 : pass_waccess::maybe_check_access_sizes (rdwr_map *rwm, tree fndecl, tree fntype,
3387 : gimple *stmt)
3388 : {
3389 2967763 : if (warning_suppressed_p (stmt, OPT_Wnonnull)
3390 2967763 : || warning_suppressed_p (stmt, OPT_Wstringop_overflow_))
3391 19435 : return;
3392 :
3393 2948332 : auto_diagnostic_group adg;
3394 :
3395 : /* Set if a warning has been issued for any argument (used to decide
3396 : whether to emit an informational note at the end). */
3397 2948332 : opt_code opt_warned = no_warning;
3398 :
3399 : /* A string describing the attributes that the warnings issued by this
3400 : function apply to. Used to print one informational note per function
3401 : call, rather than one per warning. That reduces clutter. */
3402 2948332 : char attrstr[80];
3403 2948332 : attrstr[0] = 0;
3404 :
3405 3074988 : for (rdwr_map::iterator it = rwm->begin (); it != rwm->end (); ++it)
3406 : {
3407 63332 : std::pair<int, attr_access> access = *it;
3408 :
3409 : /* Get the function call arguments corresponding to the attribute's
3410 : positional arguments. When both arguments have been specified
3411 : there will be two entries in *RWM, one for each. They are
3412 : cross-referenced by their respective argument numbers in
3413 : ACCESS.PTRARG and ACCESS.SIZARG. */
3414 63332 : const int ptridx = access.second.ptrarg;
3415 63332 : const int sizidx = access.second.sizarg;
3416 :
3417 63332 : gcc_assert (ptridx != -1);
3418 63332 : gcc_assert (access.first == ptridx || access.first == sizidx);
3419 :
3420 : /* The pointer is set to null for the entry corresponding to
3421 : the size argument. Skip it. It's handled when the entry
3422 : corresponding to the pointer argument comes up. */
3423 63332 : if (!access.second.ptr)
3424 1686 : continue;
3425 :
3426 61677 : tree ptrtype = fntype_argno_type (fntype, ptridx);
3427 61677 : if (!ptrtype)
3428 : /* A function with a prototype was redeclared without one and
3429 : the prototype has been lost. See pr102759. Avoid dealing
3430 : with this pathological case. */
3431 4 : return;
3432 :
3433 61673 : tree argtype = TREE_TYPE (ptrtype);
3434 :
3435 : /* The size of the access by the call in elements. */
3436 61673 : tree access_nelts;
3437 61673 : if (sizidx == -1)
3438 : {
3439 : /* If only the pointer attribute operand was specified and
3440 : not size, set SIZE to the greater of MINSIZE or size of
3441 : one element of the pointed to type to detect smaller
3442 : objects (null pointers are diagnosed in this case only
3443 : if the pointer is also declared with attribute nonnull. */
3444 60019 : if (access.second.minsize
3445 60019 : && access.second.minsize != HOST_WIDE_INT_M1U)
3446 50389 : access_nelts = build_int_cstu (sizetype, access.second.minsize);
3447 9630 : else if (VOID_TYPE_P (argtype) && access.second.mode == access_none)
3448 : /* Treat access mode none on a void* argument as expecting
3449 : as little as zero bytes. */
3450 242 : access_nelts = size_zero_node;
3451 : else
3452 9388 : access_nelts = size_one_node;
3453 : }
3454 : else
3455 1654 : access_nelts = rwm->get (sizidx)->size;
3456 :
3457 : /* If access_nelts is e.g. a PARM_DECL with larger precision than
3458 : sizetype, such as __int128 or _BitInt(34123) parameters,
3459 : cast it to sizetype. */
3460 61673 : if (access_nelts
3461 61673 : && INTEGRAL_TYPE_P (TREE_TYPE (access_nelts))
3462 123346 : && (TYPE_PRECISION (TREE_TYPE (access_nelts))
3463 61673 : > TYPE_PRECISION (sizetype)))
3464 2 : access_nelts = fold_convert (sizetype, access_nelts);
3465 :
3466 : /* Format the value or range to avoid an explosion of messages. */
3467 61673 : char sizstr[80];
3468 61673 : tree sizrng[2] = { size_zero_node, build_all_ones_cst (sizetype) };
3469 61673 : if (get_size_range (m_ptr_qry.rvals, access_nelts, stmt, sizrng, 1))
3470 : {
3471 61673 : char *s0 = print_generic_expr_to_str (sizrng[0]);
3472 61673 : if (tree_int_cst_equal (sizrng[0], sizrng[1]))
3473 : {
3474 61222 : gcc_checking_assert (strlen (s0) < sizeof sizstr);
3475 61222 : strcpy (sizstr, s0);
3476 : }
3477 : else
3478 : {
3479 451 : char *s1 = print_generic_expr_to_str (sizrng[1]);
3480 451 : gcc_checking_assert (strlen (s0) + strlen (s1)
3481 : < sizeof sizstr - 4);
3482 451 : sprintf (sizstr, "[%.37s, %.37s]", s0, s1);
3483 451 : free (s1);
3484 : }
3485 61673 : free (s0);
3486 : }
3487 : else
3488 0 : *sizstr = '\0';
3489 :
3490 : /* Set if a warning has been issued for the current argument. */
3491 61673 : opt_code arg_warned = no_warning;
3492 61673 : location_t loc = get_location (stmt);
3493 61673 : tree ptr = access.second.ptr;
3494 61673 : if (*sizstr
3495 61673 : && tree_int_cst_sgn (sizrng[0]) < 0
3496 61820 : && tree_int_cst_sgn (sizrng[1]) < 0)
3497 : {
3498 53 : rich_location_with_details richloc (loc, stmt);
3499 : /* Warn about negative sizes. */
3500 53 : if (access.second.internal_p)
3501 : {
3502 18 : const std::string argtypestr
3503 18 : = access.second.array_as_string (ptrtype);
3504 :
3505 18 : if (warning_at (&richloc, OPT_Wstringop_overflow_,
3506 : "bound argument %i value %s is "
3507 : "negative for a variable length array "
3508 : "argument %i of type %s",
3509 : sizidx + 1, sizstr,
3510 : ptridx + 1, argtypestr.c_str ()))
3511 18 : arg_warned = OPT_Wstringop_overflow_;
3512 18 : }
3513 35 : else if (warning_at (&richloc, OPT_Wstringop_overflow_,
3514 : "argument %i value %s is negative",
3515 : sizidx + 1, sizstr))
3516 : arg_warned = OPT_Wstringop_overflow_;
3517 :
3518 18 : if (arg_warned != no_warning)
3519 : {
3520 23 : append_attrname (access, attrstr, sizeof attrstr);
3521 : /* Remember a warning has been issued and avoid warning
3522 : again below for the same attribute. */
3523 23 : opt_warned = arg_warned;
3524 23 : continue;
3525 : }
3526 53 : }
3527 :
3528 : /* The size of the access by the call in bytes. */
3529 61650 : tree access_size = NULL_TREE;
3530 61650 : if (tree_int_cst_sgn (sizrng[0]) >= 0)
3531 : {
3532 61526 : if (COMPLETE_TYPE_P (argtype))
3533 : {
3534 : /* Multiply ACCESS_SIZE by the size of the type the pointer
3535 : argument points to. If it's incomplete the size is used
3536 : as is. */
3537 58823 : if (tree argsize = TYPE_SIZE_UNIT (argtype))
3538 58823 : if (TREE_CODE (argsize) == INTEGER_CST)
3539 : {
3540 58595 : const int prec = TYPE_PRECISION (sizetype);
3541 58595 : wide_int minsize = wi::to_wide (sizrng[0], prec);
3542 58595 : minsize *= wi::to_wide (argsize, prec);
3543 58595 : access_size = wide_int_to_tree (sizetype, minsize);
3544 58595 : }
3545 : }
3546 : else
3547 : access_size = access_nelts;
3548 : }
3549 :
3550 61650 : if (integer_zerop (ptr))
3551 : {
3552 1409 : if (!access.second.internal_p
3553 1409 : && sizidx >= 0 && tree_int_cst_sgn (sizrng[0]) > 0)
3554 : {
3555 : /* Warn about null pointers with positive sizes. This is
3556 : different from also declaring the pointer argument with
3557 : attribute nonnull when the function accepts null pointers
3558 : only when the corresponding size is zero. */
3559 26 : if (warning_at (loc, OPT_Wnonnull,
3560 : "argument %i is null but "
3561 : "the corresponding size argument "
3562 : "%i value is %s",
3563 : ptridx + 1, sizidx + 1, sizstr))
3564 8 : arg_warned = OPT_Wnonnull;
3565 : }
3566 :
3567 16 : if (arg_warned != no_warning)
3568 : {
3569 8 : append_attrname (access, attrstr, sizeof attrstr);
3570 : /* Remember a warning has been issued and avoid warning
3571 : again below for the same attribute. */
3572 8 : opt_warned = OPT_Wnonnull;
3573 8 : continue;
3574 : }
3575 : }
3576 :
3577 61642 : access_data data (m_ptr_qry.rvals, stmt, access.second.mode,
3578 61642 : NULL_TREE, false, NULL_TREE, false);
3579 60759 : access_ref* const pobj = (access.second.mode == access_write_only
3580 61642 : ? &data.dst : &data.src);
3581 61642 : tree objsize = compute_objsize (ptr, stmt, 1, pobj, &m_ptr_qry);
3582 :
3583 : /* The size of the destination or source object. */
3584 61642 : tree dstsize = NULL_TREE, srcsize = NULL_TREE;
3585 61642 : if (access.second.mode == access_read_only
3586 : || access.second.mode == access_none)
3587 : {
3588 : /* For a read-only argument there is no destination. For
3589 : no access, set the source as well and differentiate via
3590 : the access flag below. */
3591 1276 : srcsize = objsize;
3592 1276 : if (access.second.mode == access_read_only
3593 : || access.second.mode == access_none)
3594 : {
3595 : /* For a read-only attribute there is no destination so
3596 : clear OBJSIZE. This emits "reading N bytes" kind of
3597 : diagnostics instead of the "writing N bytes" kind,
3598 : unless MODE is none. */
3599 1276 : objsize = NULL_TREE;
3600 : }
3601 : }
3602 : else
3603 : dstsize = objsize;
3604 :
3605 : /* Clear the no-warning bit in case it was set by check_access
3606 : in a prior iteration so that accesses via different arguments
3607 : are diagnosed. */
3608 61642 : suppress_warning (stmt, OPT_Wstringop_overflow_, false);
3609 61642 : access_mode mode = data.mode;
3610 61642 : if (mode == access_deferred)
3611 58981 : mode = TYPE_READONLY (argtype) ? access_read_only : access_read_write;
3612 61642 : check_access (stmt, access_size, /*maxread=*/ NULL_TREE, srcsize,
3613 : dstsize, mode, &data, m_ptr_qry.rvals);
3614 :
3615 61642 : if (warning_suppressed_p (stmt, OPT_Wstringop_overflow_))
3616 : opt_warned = OPT_Wstringop_overflow_;
3617 61435 : if (opt_warned != no_warning)
3618 : {
3619 322 : if (access.second.internal_p)
3620 : {
3621 73 : unsigned HOST_WIDE_INT nelts =
3622 73 : access_nelts ? access.second.minsize : HOST_WIDE_INT_M1U;
3623 73 : tree arrtype = build_printable_array_type (argtype, nelts);
3624 73 : inform (loc, "referencing argument %u of type %qT",
3625 : ptridx + 1, arrtype);
3626 : }
3627 : else
3628 : /* If check_access issued a warning above, append the relevant
3629 : attribute to the string. */
3630 249 : append_attrname (access, attrstr, sizeof attrstr);
3631 : }
3632 : }
3633 :
3634 2948328 : if (*attrstr)
3635 : {
3636 145 : if (fndecl)
3637 129 : inform (get_location (fndecl),
3638 : "in a call to function %qD declared with attribute %qs",
3639 : fndecl, attrstr);
3640 : else
3641 16 : inform (get_location (stmt),
3642 : "in a call with type %qT and attribute %qs",
3643 : fntype, attrstr);
3644 : }
3645 2948183 : else if (opt_warned != no_warning)
3646 : {
3647 91 : if (fndecl)
3648 91 : inform (get_location (fndecl),
3649 : "in a call to function %qD", fndecl);
3650 : else
3651 0 : inform (get_location (stmt),
3652 : "in a call with type %qT", fntype);
3653 : }
3654 :
3655 : /* Set the bit in case it was cleared and not set above. */
3656 236 : if (opt_warned != no_warning)
3657 236 : suppress_warning (stmt, opt_warned);
3658 2948332 : }
3659 :
3660 : /* Check call STMT to an ordinary (non-built-in) function for invalid
3661 : accesses. Return true if a call has been handled. */
3662 :
3663 : bool
3664 17142495 : pass_waccess::check_call_access (gcall *stmt)
3665 : {
3666 17142495 : tree fntype = gimple_call_fntype (stmt);
3667 16435203 : if (!fntype)
3668 : return false;
3669 :
3670 16435203 : tree fntypeattrs = TYPE_ATTRIBUTES (fntype);
3671 16435203 : if (!fntypeattrs)
3672 : return false;
3673 :
3674 : /* Map of attribute access specifications for function arguments. */
3675 2967763 : rdwr_map rdwr_idx;
3676 2967763 : init_attr_rdwr_indices (&rdwr_idx, fntypeattrs);
3677 :
3678 2967763 : unsigned nargs = call_nargs (stmt);
3679 9179082 : for (unsigned i = 0; i != nargs; ++i)
3680 : {
3681 6211319 : tree arg = call_arg (stmt, i);
3682 :
3683 : /* Save the actual argument that corresponds to the access attribute
3684 : operand for later processing. */
3685 6211319 : if (attr_access *access = rdwr_idx.get (i))
3686 : {
3687 63979 : if (POINTER_TYPE_P (TREE_TYPE (arg)))
3688 : {
3689 62263 : access->ptr = arg;
3690 : /* A nonnull ACCESS->SIZE contains VLA bounds. */
3691 : }
3692 : else
3693 : {
3694 1716 : access->size = arg;
3695 1716 : gcc_assert (access->ptr == NULL_TREE);
3696 : }
3697 : }
3698 : }
3699 :
3700 : /* Check attribute access arguments. */
3701 2967763 : tree fndecl = gimple_call_fndecl (stmt);
3702 2967763 : maybe_check_access_sizes (&rdwr_idx, fndecl, fntype, stmt);
3703 :
3704 2967763 : check_alloc_size_call (stmt);
3705 2967763 : return true;
3706 2967763 : }
3707 :
3708 : /* Check arguments in a call STMT for attribute nonstring. */
3709 :
3710 : static void
3711 6844928 : check_nonstring_args (gcall *stmt)
3712 : {
3713 6844928 : tree fndecl = gimple_call_fndecl (stmt);
3714 :
3715 : /* Detect passing non-string arguments to functions expecting
3716 : nul-terminated strings. */
3717 6844928 : maybe_warn_nonstring_arg (fndecl, stmt);
3718 6844928 : }
3719 :
3720 : /* Issue a warning if a deallocation function such as free, realloc,
3721 : or C++ operator delete is called with an argument not returned by
3722 : a matching allocation function such as malloc or the corresponding
3723 : form of C++ operator new. */
3724 :
3725 : void
3726 6844928 : pass_waccess::maybe_check_dealloc_call (gcall *call)
3727 : {
3728 6844928 : tree fndecl = gimple_call_fndecl (call);
3729 6844928 : if (!fndecl)
3730 6635483 : return;
3731 :
3732 6435822 : unsigned argno = fndecl_dealloc_argno (fndecl);
3733 6435822 : if ((unsigned) call_nargs (call) <= argno)
3734 : return;
3735 :
3736 210128 : tree ptr = gimple_call_arg (call, argno);
3737 210128 : if (integer_zerop (ptr))
3738 : return;
3739 :
3740 210034 : access_ref aref;
3741 210034 : if (!compute_objsize (ptr, call, 0, &aref, &m_ptr_qry))
3742 : return;
3743 :
3744 210034 : tree ref = aref.ref;
3745 210034 : if (integer_zerop (ref))
3746 : return;
3747 :
3748 209922 : tree dealloc_decl = fndecl;
3749 209922 : location_t loc = gimple_location (call);
3750 :
3751 209922 : if (DECL_P (ref) || EXPR_P (ref))
3752 : {
3753 : /* Diagnose freeing a declared object. */
3754 118752 : if (aref.ref_declared ())
3755 : {
3756 152 : auto_diagnostic_group d;
3757 152 : if (warning_at (loc, OPT_Wfree_nonheap_object,
3758 : "%qD called on unallocated object %qD",
3759 : dealloc_decl, ref))
3760 : {
3761 140 : inform (get_location (ref), "declared here");
3762 140 : return;
3763 : }
3764 152 : }
3765 :
3766 : /* Diagnose freeing a pointer that includes a positive offset.
3767 : Such a pointer cannot refer to the beginning of an allocated
3768 : object. A negative offset may refer to it. */
3769 118612 : if (aref.sizrng[0] != aref.sizrng[1]
3770 118612 : && warn_dealloc_offset (loc, call, aref))
3771 : return;
3772 : }
3773 91170 : else if (CONSTANT_CLASS_P (ref))
3774 : {
3775 38 : auto_diagnostic_group d;
3776 38 : if (warning_at (loc, OPT_Wfree_nonheap_object,
3777 : "%qD called on a pointer to an unallocated "
3778 : "object %qE", dealloc_decl, ref))
3779 : {
3780 38 : if (TREE_CODE (ptr) == SSA_NAME)
3781 : {
3782 12 : gimple *def_stmt = SSA_NAME_DEF_STMT (ptr);
3783 12 : if (is_gimple_assign (def_stmt))
3784 : {
3785 12 : location_t loc = gimple_location (def_stmt);
3786 12 : inform (loc, "assigned here");
3787 : }
3788 : }
3789 38 : return;
3790 : }
3791 38 : }
3792 91132 : else if (TREE_CODE (ref) == SSA_NAME)
3793 : {
3794 : /* Also warn if the pointer argument refers to the result
3795 : of an allocation call like alloca or VLA. */
3796 91132 : gimple *def_stmt = SSA_NAME_DEF_STMT (ref);
3797 91132 : if (!def_stmt)
3798 : return;
3799 :
3800 91132 : if (is_gimple_call (def_stmt))
3801 : {
3802 45959 : auto_diagnostic_group d;
3803 45959 : bool warned = false;
3804 45959 : if (gimple_call_alloc_p (def_stmt))
3805 : {
3806 42248 : if (matching_alloc_calls_p (def_stmt, dealloc_decl))
3807 : {
3808 41828 : if (warn_dealloc_offset (loc, call, aref))
3809 : return;
3810 : }
3811 : else
3812 : {
3813 420 : tree alloc_decl = gimple_call_fndecl (def_stmt);
3814 420 : const opt_code opt =
3815 420 : (DECL_IS_OPERATOR_NEW_P (alloc_decl)
3816 172 : || DECL_IS_OPERATOR_DELETE_P (dealloc_decl)
3817 420 : ? OPT_Wmismatched_new_delete
3818 : : OPT_Wmismatched_dealloc);
3819 420 : warned = warning_at (loc, opt,
3820 : "%qD called on pointer returned "
3821 : "from a mismatched allocation "
3822 : "function", dealloc_decl);
3823 : }
3824 : }
3825 3711 : else if (gimple_call_builtin_p (def_stmt, BUILT_IN_ALLOCA)
3826 3711 : || gimple_call_builtin_p (def_stmt,
3827 : BUILT_IN_ALLOCA_WITH_ALIGN))
3828 20 : warned = warning_at (loc, OPT_Wfree_nonheap_object,
3829 : "%qD called on pointer to "
3830 : "an unallocated object",
3831 : dealloc_decl);
3832 3691 : else if (warn_dealloc_offset (loc, call, aref))
3833 : return;
3834 :
3835 440 : if (warned)
3836 : {
3837 230 : tree fndecl = gimple_call_fndecl (def_stmt);
3838 230 : inform (gimple_location (def_stmt),
3839 : "returned from %qD", fndecl);
3840 230 : return;
3841 : }
3842 45959 : }
3843 45173 : else if (gimple_nop_p (def_stmt))
3844 : {
3845 14543 : ref = SSA_NAME_VAR (ref);
3846 : /* Diagnose freeing a pointer that includes a positive offset. */
3847 14543 : if (TREE_CODE (ref) == PARM_DECL
3848 14452 : && !aref.deref
3849 14452 : && aref.sizrng[0] != aref.sizrng[1]
3850 14543 : && aref.offrng[0] > 0 && aref.offrng[1] > 0
3851 14549 : && warn_dealloc_offset (loc, call, aref))
3852 6 : return;
3853 : }
3854 : }
3855 : }
3856 :
3857 : /* Return true if either USE_STMT's basic block (that of a pointer's use)
3858 : is dominated by INVAL_STMT's (that of a pointer's invalidating statement,
3859 : which is either a clobber or a deallocation call), or if they're in
3860 : the same block, USE_STMT follows INVAL_STMT. */
3861 :
3862 : bool
3863 5204412 : pass_waccess::use_after_inval_p (gimple *inval_stmt, gimple *use_stmt,
3864 : bool last_block /* = false */)
3865 : {
3866 5204412 : tree clobvar =
3867 5204412 : gimple_clobber_p (inval_stmt) ? gimple_assign_lhs (inval_stmt) : NULL_TREE;
3868 :
3869 5204412 : basic_block inval_bb = gimple_bb (inval_stmt);
3870 5204412 : basic_block use_bb = gimple_bb (use_stmt);
3871 :
3872 5204412 : if (!inval_bb || !use_bb)
3873 : return false;
3874 :
3875 5203410 : if (inval_bb != use_bb)
3876 : {
3877 4544603 : if (dominated_by_p (CDI_DOMINATORS, use_bb, inval_bb))
3878 : return true;
3879 :
3880 4543588 : if (!clobvar || !last_block)
3881 : return false;
3882 :
3883 : /* Proceed only when looking for uses of dangling pointers. */
3884 3318270 : auto gsi = gsi_for_stmt (use_stmt);
3885 :
3886 : /* A use statement in the last basic block in a function or one that
3887 : falls through to it is after any other prior clobber of the used
3888 : variable unless it's followed by a clobber of the same variable. */
3889 3318270 : basic_block bb = use_bb;
3890 3318270 : while (bb != inval_bb
3891 4042274 : && single_succ_p (bb)
3892 5591449 : && !(single_succ_edge (bb)->flags
3893 1281639 : & (EDGE_EH | EDGE_ABNORMAL | EDGE_DFS_BACK)))
3894 : {
3895 10949245 : for (; !gsi_end_p (gsi); gsi_next_nondebug (&gsi))
3896 : {
3897 9957705 : gimple *stmt = gsi_stmt (gsi);
3898 9957705 : if (gimple_clobber_p (stmt))
3899 : {
3900 309111 : if (clobvar == gimple_assign_lhs (stmt))
3901 : /* The use is followed by a clobber. */
3902 : return false;
3903 : }
3904 : }
3905 :
3906 991540 : bb = single_succ (bb);
3907 1983080 : gsi = gsi_start_bb (bb);
3908 : }
3909 :
3910 : /* The use is one of a dangling pointer if a clobber of the variable
3911 : [the pointer points to] has not been found before the function exit
3912 : point. */
3913 3301581 : return bb == EXIT_BLOCK_PTR_FOR_FN (cfun);
3914 : }
3915 :
3916 658807 : if (bitmap_set_bit (m_bb_uids_set, inval_bb->index))
3917 : /* The first time this basic block is visited assign increasing ids
3918 : to consecutive statements in it. Use the ids to determine which
3919 : precedes which. This avoids the linear traversal on subsequent
3920 : visits to the same block. */
3921 338910 : renumber_gimple_stmt_uids_in_block (m_func, inval_bb);
3922 :
3923 658807 : return gimple_uid (inval_stmt) < gimple_uid (use_stmt);
3924 : }
3925 :
3926 : /* Issue a warning for the USE_STMT of pointer or reference REF rendered
3927 : invalid by INVAL_STMT. REF may be null when it's been optimized away.
3928 : When nonnull, INVAL_STMT is the deallocation function that rendered
3929 : the pointer or reference dangling. Otherwise, VAR is the auto variable
3930 : (including an unnamed temporary such as a compound literal) whose
3931 : lifetime's rended it dangling. MAYBE is true to issue the "maybe"
3932 : kind of warning. EQUALITY is true when the pointer is used in
3933 : an equality expression. */
3934 :
3935 : void
3936 18150 : pass_waccess::warn_invalid_pointer (tree ref, gimple *use_stmt,
3937 : gimple *inval_stmt, tree var,
3938 : bool maybe, bool equality /* = false */)
3939 : {
3940 : /* Avoid printing the unhelpful "<unknown>" in the diagnostics. */
3941 18150 : if (ref && TREE_CODE (ref) == SSA_NAME)
3942 : {
3943 18123 : tree var = SSA_NAME_VAR (ref);
3944 17431 : if (!var)
3945 : ref = NULL_TREE;
3946 : /* Don't warn for cases like when a cdtor returns 'this' on ARM. */
3947 17431 : else if (warning_suppressed_p (var, OPT_Wuse_after_free))
3948 : return;
3949 17431 : else if (DECL_ARTIFICIAL (var))
3950 728 : ref = NULL_TREE;
3951 : }
3952 :
3953 18150 : location_t use_loc = gimple_location (use_stmt);
3954 18150 : if (use_loc == UNKNOWN_LOCATION)
3955 : {
3956 0 : use_loc = m_func->function_end_locus;
3957 0 : if (!ref)
3958 : /* Avoid issuing a warning with no context other than
3959 : the function. That would make it difficult to debug
3960 : in any but very simple cases. */
3961 : return;
3962 : }
3963 :
3964 18150 : if (is_gimple_call (inval_stmt))
3965 : {
3966 17863 : if (!m_early_checks_p
3967 5878 : || (equality && warn_use_after_free < 3)
3968 5617 : || (maybe && warn_use_after_free < 2)
3969 23439 : || warning_suppressed_p (use_stmt, OPT_Wuse_after_free))
3970 12287 : return;
3971 :
3972 5576 : const tree inval_decl = gimple_call_fndecl (inval_stmt);
3973 :
3974 5576 : auto_diagnostic_group d;
3975 11030 : if ((ref && warning_at (use_loc, OPT_Wuse_after_free,
3976 : (maybe
3977 : ? G_("pointer %qE may be used after %qD")
3978 : : G_("pointer %qE used after %qD")),
3979 : ref, inval_decl))
3980 10800 : || (!ref && warning_at (use_loc, OPT_Wuse_after_free,
3981 : (maybe
3982 : ? G_("pointer may be used after %qD")
3983 : : G_("pointer used after %qD")),
3984 : inval_decl)))
3985 : {
3986 355 : location_t loc = gimple_location (inval_stmt);
3987 355 : inform (loc, "call to %qD here", inval_decl);
3988 355 : suppress_warning (use_stmt, OPT_Wuse_after_free);
3989 : }
3990 5576 : return;
3991 5576 : }
3992 :
3993 287 : if (equality
3994 281 : || (maybe && warn_dangling_pointer < 2)
3995 563 : || warning_suppressed_p (use_stmt, OPT_Wdangling_pointer_))
3996 66 : return;
3997 :
3998 221 : if (DECL_NAME (var))
3999 : {
4000 207 : auto_diagnostic_group d;
4001 207 : if ((ref
4002 174 : && warning_at (use_loc, OPT_Wdangling_pointer_,
4003 : (maybe
4004 : ? G_("dangling pointer %qE to %qD may be used")
4005 : : G_("using dangling pointer %qE to %qD")),
4006 : ref, var))
4007 207 : || (!ref
4008 214 : && warning_at (use_loc, OPT_Wdangling_pointer_,
4009 : (maybe
4010 : ? G_("dangling pointer to %qD may be used")
4011 : : G_("using a dangling pointer to %qD")),
4012 : var)))
4013 98 : inform (DECL_SOURCE_LOCATION (var),
4014 : "%qD declared here", var);
4015 207 : suppress_warning (use_stmt, OPT_Wdangling_pointer_);
4016 207 : return;
4017 207 : }
4018 :
4019 14 : if ((ref
4020 14 : && warning_at (use_loc, OPT_Wdangling_pointer_,
4021 : (maybe
4022 : ? G_("dangling pointer %qE to an unnamed temporary "
4023 : "may be used")
4024 : : G_("using dangling pointer %qE to an unnamed "
4025 : "temporary")),
4026 : ref))
4027 14 : || (!ref
4028 12 : && warning_at (use_loc, OPT_Wdangling_pointer_,
4029 : (maybe
4030 : ? G_("dangling pointer to an unnamed temporary "
4031 : "may be used")
4032 : : G_("using a dangling pointer to an unnamed "
4033 : "temporary")))))
4034 : {
4035 14 : inform (DECL_SOURCE_LOCATION (var),
4036 : "unnamed temporary defined here");
4037 14 : suppress_warning (use_stmt, OPT_Wdangling_pointer_);
4038 : }
4039 : }
4040 :
4041 : /* If STMT is a call to either the standard realloc or to a user-defined
4042 : reallocation function returns its LHS and set *PTR to the reallocated
4043 : pointer. Otherwise return null. */
4044 :
4045 : static tree
4046 568609 : get_realloc_lhs (gimple *stmt, tree *ptr)
4047 : {
4048 568609 : if (gimple_call_builtin_p (stmt, BUILT_IN_REALLOC))
4049 : {
4050 20653 : *ptr = gimple_call_arg (stmt, 0);
4051 20653 : return gimple_call_lhs (stmt);
4052 : }
4053 :
4054 920803 : gcall *call = dyn_cast<gcall *>(stmt);
4055 372987 : if (!call)
4056 : return NULL_TREE;
4057 :
4058 372987 : tree fnattr = NULL_TREE;
4059 372987 : tree fndecl = gimple_call_fndecl (call);
4060 372987 : if (fndecl)
4061 372987 : fnattr = DECL_ATTRIBUTES (fndecl);
4062 : else
4063 : {
4064 0 : tree fntype = gimple_call_fntype (stmt);
4065 0 : if (!fntype)
4066 : return NULL_TREE;
4067 0 : fnattr = TYPE_ATTRIBUTES (fntype);
4068 : }
4069 :
4070 372987 : if (!fnattr)
4071 : return NULL_TREE;
4072 :
4073 365816 : for (tree ats = fnattr; (ats = lookup_attribute ("*dealloc", ats));
4074 12453 : ats = TREE_CHAIN (ats))
4075 : {
4076 12593 : tree args = TREE_VALUE (ats);
4077 12593 : if (!args)
4078 0 : continue;
4079 :
4080 12593 : tree alloc = TREE_VALUE (args);
4081 12593 : if (!alloc)
4082 0 : continue;
4083 :
4084 12593 : if (alloc == DECL_NAME (fndecl))
4085 : {
4086 140 : unsigned argno = 0;
4087 140 : if (tree index = TREE_CHAIN (args))
4088 82 : argno = TREE_INT_CST_LOW (TREE_VALUE (index)) - 1;
4089 140 : *ptr = gimple_call_arg (stmt, argno);
4090 140 : return gimple_call_lhs (stmt);
4091 : }
4092 : }
4093 :
4094 : return NULL_TREE;
4095 : }
4096 :
4097 : /* Warn if STMT is a call to a deallocation function that's not a match
4098 : for the REALLOC_STMT call. Return true if warned. */
4099 :
4100 : static bool
4101 83077 : maybe_warn_mismatched_realloc (tree ptr, gimple *realloc_stmt, gimple *stmt)
4102 : {
4103 83077 : if (!is_gimple_call (stmt))
4104 : return false;
4105 :
4106 39503 : tree fndecl = gimple_call_fndecl (stmt);
4107 39503 : if (!fndecl)
4108 : return false;
4109 :
4110 39503 : unsigned argno = fndecl_dealloc_argno (fndecl);
4111 39503 : if (call_nargs (stmt) <= argno)
4112 : return false;
4113 :
4114 2342 : if (matching_alloc_calls_p (realloc_stmt, fndecl))
4115 : return false;
4116 :
4117 : /* Avoid printing the unhelpful "<unknown>" in the diagnostics. */
4118 42 : if (ptr && TREE_CODE (ptr) == SSA_NAME
4119 84 : && (!SSA_NAME_VAR (ptr) || DECL_ARTIFICIAL (SSA_NAME_VAR (ptr))))
4120 : ptr = NULL_TREE;
4121 :
4122 42 : location_t loc = gimple_location (stmt);
4123 42 : tree realloc_decl = gimple_call_fndecl (realloc_stmt);
4124 42 : tree dealloc_decl = gimple_call_fndecl (stmt);
4125 42 : if (ptr && !warning_at (loc, OPT_Wmismatched_dealloc,
4126 : "%qD called on pointer %qE passed to mismatched "
4127 : "allocation function %qD",
4128 : dealloc_decl, ptr, realloc_decl))
4129 3 : return false;
4130 39 : if (!ptr && !warning_at (loc, OPT_Wmismatched_dealloc,
4131 : "%qD called on a pointer passed to mismatched "
4132 : "reallocation function %qD",
4133 : dealloc_decl, realloc_decl))
4134 0 : return false;
4135 :
4136 39 : inform (gimple_location (realloc_stmt),
4137 : "call to %qD", realloc_decl);
4138 39 : return true;
4139 : }
4140 :
4141 : /* Return true if P and Q point to the same object, and false if they
4142 : either don't or their relationship cannot be determined. */
4143 :
4144 : static bool
4145 83048 : pointers_related_p (gimple *stmt, tree p, tree q, pointer_query &qry,
4146 : auto_bitmap &visited)
4147 : {
4148 83048 : if (!ptr_derefs_may_alias_p (p, q))
4149 : return false;
4150 :
4151 : /* TODO: Work harder to rule out relatedness. */
4152 83048 : access_ref pref, qref;
4153 83048 : if (!qry.get_ref (p, stmt, &pref, 0)
4154 83048 : || !qry.get_ref (q, stmt, &qref, 0))
4155 : /* GET_REF() only rarely fails. When it does, it's likely because
4156 : it involves a self-referential PHI. Return a conservative result. */
4157 0 : return false;
4158 :
4159 83048 : if (pref.ref == qref.ref)
4160 : return true;
4161 :
4162 : /* If either pointer is a PHI, iterate over all its operands and
4163 : return true if they're all related to the other pointer. */
4164 108 : tree ptr = q;
4165 108 : unsigned version;
4166 108 : gphi *phi = pref.phi ();
4167 108 : if (phi)
4168 108 : version = SSA_NAME_VERSION (pref.ref);
4169 : else
4170 : {
4171 0 : phi = qref.phi ();
4172 0 : if (!phi)
4173 : return false;
4174 :
4175 0 : ptr = p;
4176 0 : version = SSA_NAME_VERSION (qref.ref);
4177 : }
4178 :
4179 108 : if (!bitmap_set_bit (visited, version))
4180 : return true;
4181 :
4182 60 : unsigned nargs = gimple_phi_num_args (phi);
4183 180 : for (unsigned i = 0; i != nargs; ++i)
4184 : {
4185 120 : tree arg = gimple_phi_arg_def (phi, i);
4186 120 : if (!pointers_related_p (stmt, arg, ptr, qry, visited))
4187 : return false;
4188 : }
4189 :
4190 : return true;
4191 : }
4192 :
4193 : /* Convenience wrapper for the above. */
4194 :
4195 : static bool
4196 82928 : pointers_related_p (gimple *stmt, tree p, tree q, pointer_query &qry)
4197 : {
4198 82928 : auto_bitmap visited;
4199 82928 : return pointers_related_p (stmt, p, q, qry, visited);
4200 82928 : }
4201 :
4202 : /* For a STMT either a call to a deallocation function or a clobber, warn
4203 : for uses of the pointer PTR it was called with (including its copies
4204 : or others derived from it by pointer arithmetic). If STMT is a clobber,
4205 : VAR is the decl of the clobbered variable. When MAYBE is true use
4206 : a "maybe" form of diagnostic. */
4207 :
4208 : void
4209 568609 : pass_waccess::check_pointer_uses (gimple *stmt, tree ptr,
4210 : tree var /* = NULL_TREE */,
4211 : bool maybe /* = false */)
4212 : {
4213 568609 : gcc_assert (TREE_CODE (ptr) == SSA_NAME);
4214 :
4215 568609 : const bool check_dangling = !is_gimple_call (stmt);
4216 568609 : basic_block stmt_bb = gimple_bb (stmt);
4217 :
4218 : /* If STMT is a reallocation function set to the reallocated pointer
4219 : and the LHS of the call, respectively. */
4220 568609 : tree realloc_ptr = NULL_TREE;
4221 568609 : tree realloc_lhs = get_realloc_lhs (stmt, &realloc_ptr);
4222 :
4223 568609 : auto_bitmap visited;
4224 :
4225 568609 : auto_vec<tree, 8> pointers;
4226 568609 : pointers.quick_push (ptr);
4227 568609 : hash_map<tree, int> *phi_map = nullptr;
4228 :
4229 : /* Starting with PTR, iterate over POINTERS added by the loop, and
4230 : either warn for their uses in basic blocks dominated by the STMT
4231 : or in statements that follow it in the same basic block, or add
4232 : them to POINTERS if they point into the same object as PTR (i.e.,
4233 : are obtained by pointer arithmetic on PTR). */
4234 2605634 : for (unsigned i = 0; i != pointers.length (); ++i)
4235 : {
4236 734208 : tree ptr = pointers[i];
4237 734208 : if (!bitmap_set_bit (visited, SSA_NAME_VERSION (ptr)))
4238 : /* Avoid revisiting the same pointer. */
4239 43 : continue;
4240 :
4241 734165 : use_operand_p use_p;
4242 734165 : imm_use_iterator iter;
4243 4626338 : FOR_EACH_IMM_USE_FAST (use_p, iter, ptr)
4244 : {
4245 3158008 : gimple *use_stmt = USE_STMT (use_p);
4246 3158008 : if (use_stmt == stmt || is_gimple_debug (use_stmt))
4247 1391458 : continue;
4248 :
4249 : /* A clobber isn't a use. */
4250 1766550 : if (gimple_clobber_p (use_stmt))
4251 62820 : continue;
4252 :
4253 1703730 : if (realloc_lhs)
4254 : {
4255 : /* Check to see if USE_STMT is a mismatched deallocation
4256 : call for the pointer passed to realloc. That's a bug
4257 : regardless of the pointer's value and so warn. */
4258 83077 : if (maybe_warn_mismatched_realloc (*use_p->use, stmt, use_stmt))
4259 149 : continue;
4260 :
4261 : /* Pointers passed to realloc that are used in basic blocks
4262 : where the realloc call is known to have failed are valid.
4263 : Ignore pointers that nothing is known about. Those could
4264 : have escaped along with their nullness. */
4265 83038 : prange vr;
4266 83038 : if (m_ptr_qry.rvals->range_of_expr (vr, realloc_lhs, use_stmt))
4267 : {
4268 83038 : if (vr.zero_p ())
4269 110 : continue;
4270 :
4271 82928 : if (!pointers_related_p (stmt, ptr, realloc_ptr, m_ptr_qry))
4272 0 : continue;
4273 : }
4274 83038 : }
4275 :
4276 1703790 : if (check_dangling
4277 1703581 : && gimple_code (use_stmt) == GIMPLE_RETURN)
4278 : /* Avoid interfering with -Wreturn-local-addr (which runs only
4279 : with optimization enabled so it won't diagnose cases that
4280 : would be caught here when optimization is disabled). */
4281 209 : continue;
4282 :
4283 1703372 : bool equality = false;
4284 1703372 : if (is_gimple_assign (use_stmt))
4285 : {
4286 984276 : tree_code code = gimple_assign_rhs_code (use_stmt);
4287 984276 : equality = code == EQ_EXPR || code == NE_EXPR;
4288 : }
4289 719096 : else if (gcond *cond = dyn_cast<gcond *>(use_stmt))
4290 : {
4291 209716 : tree_code code = gimple_cond_code (cond);
4292 209716 : equality = code == EQ_EXPR || code == NE_EXPR;
4293 : }
4294 509380 : else if (gphi *phi = dyn_cast <gphi *> (use_stmt))
4295 : {
4296 : /* Only add a PHI result to POINTERS if all its
4297 : operands are related to PTR, otherwise continue. The
4298 : PHI result is related once we've reached all arguments
4299 : through this iteration. That also means any invariant
4300 : argument will make the PHI not related. For arguments
4301 : flowing over natural loop backedges we are optimistic
4302 : (and diagnose the first iteration). */
4303 132507 : tree lhs = gimple_phi_result (phi);
4304 132507 : if (!phi_map)
4305 47358 : phi_map = new hash_map<tree, int>;
4306 132507 : bool existed_p;
4307 132507 : int &related = phi_map->get_or_insert (lhs, &existed_p);
4308 132507 : if (!existed_p)
4309 : {
4310 70478 : related = gimple_phi_num_args (phi) - 1;
4311 348253 : for (unsigned j = 0; j < gimple_phi_num_args (phi); ++j)
4312 : {
4313 277775 : if ((unsigned) phi_arg_index_from_use (use_p) == j)
4314 70478 : continue;
4315 207297 : tree arg = gimple_phi_arg_def (phi, j);
4316 207297 : edge e = gimple_phi_arg_edge (phi, j);
4317 207297 : basic_block arg_bb;
4318 207297 : if (dominated_by_p (CDI_DOMINATORS, e->src, e->dest)
4319 : /* Make sure we are not forward visiting a
4320 : backedge argument. */
4321 207297 : && (TREE_CODE (arg) != SSA_NAME
4322 25665 : || (!SSA_NAME_IS_DEFAULT_DEF (arg)
4323 25665 : && ((arg_bb
4324 25665 : = gimple_bb (SSA_NAME_DEF_STMT (arg)))
4325 25665 : != e->dest)
4326 13567 : && !dominated_by_p (CDI_DOMINATORS,
4327 : e->dest, arg_bb))))
4328 13567 : related--;
4329 : }
4330 : }
4331 : else
4332 62029 : related--;
4333 :
4334 132507 : if (related == 0)
4335 20794 : pointers.safe_push (lhs);
4336 132507 : continue;
4337 132507 : }
4338 :
4339 : /* Warn if USE_STMT is dominated by the deallocation STMT.
4340 : Otherwise, add the pointer to POINTERS so that the uses
4341 : of any other pointers derived from it can be checked. */
4342 1570865 : if (use_after_inval_p (stmt, use_stmt, check_dangling))
4343 : {
4344 18027 : basic_block use_bb = gimple_bb (use_stmt);
4345 18027 : bool this_maybe
4346 : = (maybe
4347 18027 : || !dominated_by_p (CDI_POST_DOMINATORS, stmt_bb, use_bb));
4348 18027 : warn_invalid_pointer (*use_p->use, use_stmt, stmt, var,
4349 : this_maybe, equality);
4350 18027 : continue;
4351 18027 : }
4352 :
4353 1552838 : if (is_gimple_assign (use_stmt))
4354 : {
4355 982430 : tree lhs = gimple_assign_lhs (use_stmt);
4356 982430 : if (TREE_CODE (lhs) == SSA_NAME)
4357 : {
4358 650447 : tree_code rhs_code = gimple_assign_rhs_code (use_stmt);
4359 650447 : if (rhs_code == POINTER_PLUS_EXPR || rhs_code == SSA_NAME)
4360 143475 : pointers.safe_push (lhs);
4361 : }
4362 982430 : continue;
4363 982430 : }
4364 :
4365 3728416 : if (gcall *call = dyn_cast <gcall *>(use_stmt))
4366 : {
4367 359893 : if (gimple_call_return_arg (call) == ptr)
4368 36272 : if (tree lhs = gimple_call_lhs (call))
4369 1330 : if (TREE_CODE (lhs) == SSA_NAME)
4370 1330 : pointers.safe_push (lhs);
4371 359893 : continue;
4372 359893 : }
4373 734165 : }
4374 : }
4375 :
4376 568609 : if (phi_map)
4377 47358 : delete phi_map;
4378 568609 : }
4379 :
4380 : /* Check call STMT for invalid accesses. */
4381 :
4382 : void
4383 22978828 : pass_waccess::check_call (gcall *stmt)
4384 : {
4385 : /* Skip special calls generated by the compiler. */
4386 22978828 : if (gimple_call_from_thunk_p (stmt))
4387 : return;
4388 :
4389 : /* .ASAN_MARK doesn't access any vars, only modifies shadow memory. */
4390 22975836 : if (gimple_call_internal_p (stmt)
4391 22975836 : && gimple_call_internal_fn (stmt) == IFN_ASAN_MARK)
4392 : return;
4393 :
4394 22963286 : if (m_check_dangling_p)
4395 : {
4396 16118358 : check_call_dangling (stmt);
4397 :
4398 : /* Don't do any other checks when doing dangling pointer checks the
4399 : second time. */
4400 16118358 : if (!m_early_checks_p)
4401 : return;
4402 : }
4403 :
4404 17142495 : if (gimple_call_builtin_p (stmt, BUILT_IN_NORMAL))
4405 3554216 : check_builtin (stmt);
4406 :
4407 17142495 : if (tree callee = gimple_call_fndecl (stmt))
4408 : {
4409 : /* Check for uses of the pointer passed to either a standard
4410 : or a user-defined deallocation function. */
4411 16085375 : unsigned argno = fndecl_dealloc_argno (callee);
4412 16085375 : if (argno < (unsigned) call_nargs (stmt))
4413 : {
4414 327866 : tree arg = call_arg (stmt, argno);
4415 327866 : if (TREE_CODE (arg) == SSA_NAME)
4416 327556 : check_pointer_uses (stmt, arg);
4417 : }
4418 : }
4419 :
4420 17142495 : check_call_access (stmt);
4421 :
4422 17142495 : if (m_early_checks_p)
4423 : return;
4424 :
4425 6844928 : maybe_check_dealloc_call (stmt);
4426 6844928 : check_nonstring_args (stmt);
4427 : }
4428 :
4429 : /* Check non-call STMT for invalid accesses. */
4430 :
4431 : void
4432 132345833 : pass_waccess::check_stmt (gimple *stmt)
4433 : {
4434 132345833 : if (m_check_dangling_p
4435 132345833 : && gimple_clobber_p (stmt, CLOBBER_STORAGE_END))
4436 : {
4437 : /* Ignore clobber statements in blocks with exceptional edges. */
4438 3352878 : basic_block bb = gimple_bb (stmt);
4439 3352878 : edge e = EDGE_PRED (bb, 0);
4440 3352878 : if (e->flags & EDGE_EH)
4441 : return;
4442 :
4443 2591897 : tree var = gimple_assign_lhs (stmt);
4444 2591897 : m_clobbers.put (var, stmt);
4445 2591897 : return;
4446 : }
4447 :
4448 128992955 : if (is_gimple_assign (stmt))
4449 : {
4450 : /* Clobbered unnamed temporaries such as compound literals can be
4451 : revived. Check for an assignment to one and remove it from
4452 : M_CLOBBERS. */
4453 95987696 : tree lhs = gimple_assign_lhs (stmt);
4454 119782484 : while (handled_component_p (lhs))
4455 23794788 : lhs = TREE_OPERAND (lhs, 0);
4456 :
4457 95987696 : if (auto_var_p (lhs))
4458 15497510 : m_clobbers.remove (lhs);
4459 95987696 : return;
4460 : }
4461 :
4462 33005259 : if (greturn *ret = dyn_cast <greturn *> (stmt))
4463 : {
4464 5272919 : if (optimize && flag_isolate_erroneous_paths_dereference)
4465 : /* Avoid interfering with -Wreturn-local-addr (which runs only
4466 : with optimization enabled). */
4467 5272918 : return;
4468 :
4469 1105375 : tree arg = gimple_return_retval (ret);
4470 1105375 : if (!arg || TREE_CODE (arg) != ADDR_EXPR)
4471 : return;
4472 :
4473 313 : arg = TREE_OPERAND (arg, 0);
4474 421 : while (handled_component_p (arg))
4475 108 : arg = TREE_OPERAND (arg, 0);
4476 :
4477 313 : if (!auto_var_p (arg))
4478 : return;
4479 :
4480 3 : gimple **pclobber = m_clobbers.get (arg);
4481 3 : if (!pclobber)
4482 : return;
4483 :
4484 1 : if (!use_after_inval_p (*pclobber, stmt))
4485 : return;
4486 :
4487 1 : warn_invalid_pointer (NULL_TREE, stmt, *pclobber, arg, false);
4488 : }
4489 : }
4490 :
4491 : /* Check basic block BB for invalid accesses. */
4492 :
4493 : void
4494 44245572 : pass_waccess::check_block (basic_block bb)
4495 : {
4496 : /* Iterate over statements, looking for function calls. */
4497 243815805 : for (auto si = gsi_start_bb (bb); !gsi_end_p (si);
4498 155324661 : gsi_next_nondebug (&si))
4499 : {
4500 155324661 : gimple *stmt = gsi_stmt (si);
4501 155324661 : if (gcall *call = dyn_cast <gcall *> (stmt))
4502 22978828 : check_call (call);
4503 : else
4504 132345833 : check_stmt (stmt);
4505 : }
4506 44245572 : }
4507 :
4508 : /* Return the argument that the call STMT to a built-in function returns
4509 : (including with an offset) or null if it doesn't. */
4510 :
4511 : tree
4512 2344676 : pass_waccess::gimple_call_return_arg (gcall *call)
4513 : {
4514 : /* Check for attribute fn spec to see if the function returns one
4515 : of its arguments. */
4516 2344676 : attr_fnspec fnspec = gimple_call_fnspec (call);
4517 2344676 : unsigned int argno;
4518 2344676 : if (!fnspec.returns_arg (&argno))
4519 : {
4520 2270645 : if (gimple_call_num_args (call) < 1)
4521 : return NULL_TREE;
4522 :
4523 2201888 : if (!gimple_call_builtin_p (call, BUILT_IN_NORMAL))
4524 : return NULL_TREE;
4525 :
4526 295639 : tree fndecl = gimple_call_fndecl (call);
4527 295639 : switch (DECL_FUNCTION_CODE (fndecl))
4528 : {
4529 : case BUILT_IN_MEMPCPY:
4530 : case BUILT_IN_MEMPCPY_CHK:
4531 : case BUILT_IN_MEMCHR:
4532 : case BUILT_IN_STRCHR:
4533 : case BUILT_IN_STRRCHR:
4534 : case BUILT_IN_STRSTR:
4535 : case BUILT_IN_STPCPY:
4536 : case BUILT_IN_STPCPY_CHK:
4537 : case BUILT_IN_STPNCPY:
4538 : case BUILT_IN_STPNCPY_CHK:
4539 : argno = 0;
4540 : break;
4541 :
4542 : default:
4543 : return NULL_TREE;
4544 : }
4545 : }
4546 :
4547 89733 : if (gimple_call_num_args (call) <= argno)
4548 : return NULL_TREE;
4549 :
4550 89733 : return gimple_call_arg (call, argno);
4551 : }
4552 :
4553 : /* Check for and diagnose all uses of the dangling pointer VAR to the auto
4554 : object DECL whose lifetime has ended. OBJREF is true when VAR denotes
4555 : an access to a DECL that may have been clobbered. */
4556 :
4557 : void
4558 14641991 : pass_waccess::check_dangling_uses (tree var, tree decl, bool maybe /* = false */,
4559 : bool objref /* = false */)
4560 : {
4561 14641991 : if (!decl || !auto_var_p (decl))
4562 6504068 : return;
4563 :
4564 8137923 : gimple **pclob = m_clobbers.get (decl);
4565 8137923 : if (!pclob)
4566 : return;
4567 :
4568 3632210 : if (!objref)
4569 : {
4570 174969 : check_pointer_uses (*pclob, var, decl, maybe);
4571 174969 : return;
4572 : }
4573 :
4574 3457241 : gimple *use_stmt = SSA_NAME_DEF_STMT (var);
4575 3457241 : if (!use_after_inval_p (*pclob, use_stmt, true))
4576 : return;
4577 :
4578 96 : basic_block use_bb = gimple_bb (use_stmt);
4579 96 : basic_block clob_bb = gimple_bb (*pclob);
4580 96 : maybe = maybe || !dominated_by_p (CDI_POST_DOMINATORS, clob_bb, use_bb);
4581 96 : warn_invalid_pointer (var, use_stmt, *pclob, decl, maybe, false);
4582 : }
4583 :
4584 : /* Diagnose stores in BB and (recursively) its predecessors of the addresses
4585 : of local variables into nonlocal pointers that are left dangling after
4586 : the function returns. Returns true when we can continue walking
4587 : the CFG to predecessors. */
4588 :
4589 : bool
4590 15730471 : pass_waccess::check_dangling_stores (basic_block bb,
4591 : hash_set<tree> &stores)
4592 : {
4593 : /* Iterate backwards over the statements looking for a store of
4594 : the address of a local variable into a nonlocal pointer. */
4595 52949139 : for (auto gsi = gsi_last_nondebug_bb (bb); ; gsi_prev_nondebug (&gsi))
4596 : {
4597 52949139 : gimple *stmt = gsi_stmt (gsi);
4598 52949139 : if (!stmt)
4599 : break;
4600 :
4601 41069759 : if (warning_suppressed_p (stmt, OPT_Wdangling_pointer_))
4602 37218049 : continue;
4603 :
4604 41013862 : if (is_gimple_call (stmt)
4605 41013862 : && !(gimple_call_flags (stmt) & (ECF_CONST | ECF_PURE)))
4606 : /* Avoid looking before nonconst, nonpure calls since those might
4607 : use the escaped locals. */
4608 3851091 : return false;
4609 :
4610 37322245 : if (!is_gimple_assign (stmt) || gimple_clobber_p (stmt)
4611 61819587 : || !gimple_store_p (stmt))
4612 32086293 : continue;
4613 :
4614 5235952 : access_ref lhs_ref;
4615 5235952 : tree lhs = gimple_assign_lhs (stmt);
4616 5235952 : if (!m_ptr_qry.get_ref (lhs, stmt, &lhs_ref, 0))
4617 9350 : continue;
4618 :
4619 5226602 : if (TREE_CODE (lhs_ref.ref) == MEM_REF)
4620 : {
4621 23369 : lhs_ref.ref = TREE_OPERAND (lhs_ref.ref, 0);
4622 23369 : ++lhs_ref.deref;
4623 : }
4624 5226602 : if (TREE_CODE (lhs_ref.ref) == ADDR_EXPR)
4625 : {
4626 10646 : lhs_ref.ref = TREE_OPERAND (lhs_ref.ref, 0);
4627 10646 : --lhs_ref.deref;
4628 : }
4629 5226602 : if (TREE_CODE (lhs_ref.ref) == SSA_NAME)
4630 : {
4631 1072420 : gimple *def_stmt = SSA_NAME_DEF_STMT (lhs_ref.ref);
4632 1072420 : if (!gimple_nop_p (def_stmt))
4633 : /* Avoid looking at or before stores into unknown objects. */
4634 : return false;
4635 :
4636 912946 : lhs_ref.ref = SSA_NAME_VAR (lhs_ref.ref);
4637 : }
4638 :
4639 5067128 : if (TREE_CODE (lhs_ref.ref) == PARM_DECL
4640 5067128 : && (lhs_ref.deref - DECL_BY_REFERENCE (lhs_ref.ref)) > 0)
4641 : /* Assignment through a (real) pointer/reference parameter. */;
4642 7397600 : else if (VAR_P (lhs_ref.ref)
4643 4219689 : && !auto_var_p (lhs_ref.ref))
4644 : /* Assignment to/through a non-local variable. */;
4645 : else
4646 : /* Something else, don't warn. */
4647 3177911 : continue;
4648 :
4649 1889217 : if (stores.add (lhs_ref.ref))
4650 1291132 : continue;
4651 :
4652 : /* FIXME: Handle stores of alloca() and VLA. */
4653 598085 : access_ref rhs_ref;
4654 598085 : tree rhs = gimple_assign_rhs1 (stmt);
4655 598085 : if (!m_ptr_qry.get_ref (rhs, stmt, &rhs_ref, 0)
4656 598085 : || rhs_ref.deref != -1)
4657 570562 : continue;
4658 :
4659 27523 : if (!auto_var_p (rhs_ref.ref))
4660 26904 : continue;
4661 :
4662 619 : auto_diagnostic_group d;
4663 619 : location_t loc = gimple_location (stmt);
4664 619 : if (warning_at (loc, OPT_Wdangling_pointer_,
4665 : "storing the address of local variable %qD in %qE",
4666 : rhs_ref.ref, lhs))
4667 : {
4668 45 : suppress_warning (stmt, OPT_Wdangling_pointer_);
4669 :
4670 45 : location_t loc = DECL_SOURCE_LOCATION (rhs_ref.ref);
4671 45 : inform (loc, "%qD declared here", rhs_ref.ref);
4672 :
4673 45 : loc = DECL_SOURCE_LOCATION (lhs_ref.ref);
4674 45 : inform (loc, "%qD declared here", lhs_ref.ref);
4675 : }
4676 37219287 : }
4677 :
4678 11879380 : return true;
4679 : }
4680 :
4681 : /* Diagnose stores of the addresses of local variables into nonlocal
4682 : pointers that are left dangling after the function returns. */
4683 :
4684 : void
4685 3889864 : pass_waccess::check_dangling_stores ()
4686 : {
4687 3889864 : if (EDGE_COUNT (EXIT_BLOCK_PTR_FOR_FN (m_func)->preds) == 0)
4688 58241 : return;
4689 :
4690 3831623 : auto_bitmap bbs;
4691 3831623 : hash_set<tree> stores;
4692 3831623 : auto_vec<edge_iterator, 8> worklist (n_basic_blocks_for_fn (cfun) + 1);
4693 3831623 : worklist.quick_push (ei_start (EXIT_BLOCK_PTR_FOR_FN (m_func)->preds));
4694 34256897 : do
4695 : {
4696 34256897 : edge_iterator ei = worklist.last ();
4697 34256897 : basic_block src = ei_edge (ei)->src;
4698 34256897 : if (bitmap_set_bit (bbs, src->index))
4699 : {
4700 15730471 : if (check_dangling_stores (src, stores)
4701 15730471 : && EDGE_COUNT (src->preds) > 0)
4702 10323226 : worklist.quick_push (ei_start (src->preds));
4703 : }
4704 : else
4705 : {
4706 18526426 : if (ei_one_before_end_p (ei))
4707 14154849 : worklist.pop ();
4708 : else
4709 4371577 : ei_next (&worklist.last ());
4710 : }
4711 : }
4712 68513794 : while (!worklist.is_empty ());
4713 3831623 : }
4714 :
4715 : /* Check for and diagnose uses of dangling pointers to auto objects
4716 : whose lifetime has ended. */
4717 :
4718 : void
4719 3889864 : pass_waccess::check_dangling_uses ()
4720 : {
4721 3889864 : tree var;
4722 3889864 : unsigned i;
4723 114936872 : FOR_EACH_SSA_NAME (i, var, m_func)
4724 : {
4725 : /* For each SSA_NAME pointer VAR find the object it points to.
4726 : If the object is a clobbered local variable, check to see
4727 : if any of VAR's uses (or those of other pointers derived
4728 : from VAR) happens after the clobber. If so, warn. */
4729 :
4730 106106986 : gimple *def_stmt = SSA_NAME_DEF_STMT (var);
4731 106106986 : if (is_gimple_assign (def_stmt))
4732 : {
4733 67824567 : tree rhs = gimple_assign_rhs1 (def_stmt);
4734 67824567 : if (TREE_CODE (rhs) == ADDR_EXPR)
4735 : {
4736 4551542 : if (!POINTER_TYPE_P (TREE_TYPE (var)))
4737 2030438 : continue;
4738 2521104 : check_dangling_uses (var, TREE_OPERAND (rhs, 0));
4739 : }
4740 : else
4741 : {
4742 : /* For other expressions, check the base DECL to see
4743 : if it's been clobbered, most likely as a result of
4744 : inlining a reference to it. */
4745 63273025 : tree decl = get_base_address (rhs);
4746 63273025 : if (DECL_P (decl))
4747 11891589 : check_dangling_uses (var, decl, false, true);
4748 : }
4749 : }
4750 38282419 : else if (POINTER_TYPE_P (TREE_TYPE (var)))
4751 : {
4752 6317315 : if (gcall *call = dyn_cast<gcall *>(def_stmt))
4753 : {
4754 1984783 : if (tree arg = gimple_call_return_arg (call))
4755 : {
4756 31959 : access_ref aref;
4757 31959 : if (m_ptr_qry.get_ref (arg, call, &aref, 0)
4758 31959 : && aref.deref < 0)
4759 9551 : check_dangling_uses (var, aref.ref);
4760 : }
4761 : }
4762 111656453 : else if (gphi *phi = dyn_cast <gphi *>(def_stmt))
4763 : {
4764 609445 : unsigned nargs = gimple_phi_num_args (phi);
4765 2094356 : for (unsigned i = 0; i != nargs; ++i)
4766 : {
4767 1484911 : access_ref aref;
4768 1484911 : tree arg = gimple_phi_arg_def (phi, i);
4769 1484911 : if (m_ptr_qry.get_ref (arg, phi, &aref, 0)
4770 1484911 : && aref.deref < 0)
4771 219747 : check_dangling_uses (var, aref.ref, true);
4772 : }
4773 : }
4774 : }
4775 : }
4776 3889864 : }
4777 :
4778 : /* Check CALL arguments for dangling pointers (those that have been
4779 : clobbered) and warn if found. */
4780 :
4781 : void
4782 16118358 : pass_waccess::check_call_dangling (gcall *call)
4783 : {
4784 16118358 : unsigned nargs = gimple_call_num_args (call);
4785 47050956 : for (unsigned i = 0; i != nargs; ++i)
4786 : {
4787 30932598 : tree arg = gimple_call_arg (call, i);
4788 30932598 : if (TREE_CODE (arg) != ADDR_EXPR)
4789 30932572 : continue;
4790 :
4791 8586030 : arg = TREE_OPERAND (arg, 0);
4792 8586030 : if (!DECL_P (arg))
4793 2835801 : continue;
4794 :
4795 5750229 : gimple **pclobber = m_clobbers.get (arg);
4796 5750229 : if (!pclobber)
4797 5573924 : continue;
4798 :
4799 176305 : if (!use_after_inval_p (*pclobber, call))
4800 176279 : continue;
4801 :
4802 26 : warn_invalid_pointer (NULL_TREE, call, *pclobber, arg, false);
4803 : }
4804 16118358 : }
4805 :
4806 : /* Check function FUN for invalid accesses. */
4807 :
4808 : unsigned
4809 5361948 : pass_waccess::execute (function *fun)
4810 : {
4811 5361948 : auto_urlify_attributes sentinel;
4812 :
4813 5361948 : calculate_dominance_info (CDI_DOMINATORS);
4814 5361948 : calculate_dominance_info (CDI_POST_DOMINATORS);
4815 :
4816 : /* Set or clear EDGE_DFS_BACK bits on back edges. */
4817 5361948 : mark_dfs_back_edges (fun);
4818 :
4819 : /* Create a new ranger instance and associate it with FUN. */
4820 5361948 : m_ptr_qry.rvals = enable_ranger (fun);
4821 5361948 : m_func = fun;
4822 :
4823 5361948 : auto_bitmap bb_uids_set (&bitmap_default_obstack);
4824 5361948 : m_bb_uids_set = bb_uids_set;
4825 :
4826 5361948 : set_gimple_stmt_max_uid (m_func, 0);
4827 :
4828 5361948 : basic_block bb;
4829 49607520 : FOR_EACH_BB_FN (bb, fun)
4830 44245572 : check_block (bb);
4831 :
4832 5361948 : if (m_check_dangling_p)
4833 : {
4834 3889864 : check_dangling_uses ();
4835 3889864 : check_dangling_stores ();
4836 : }
4837 :
4838 5361948 : if (dump_file)
4839 167 : m_ptr_qry.dump (dump_file, (dump_flags & TDF_DETAILS) != 0);
4840 :
4841 5361948 : m_ptr_qry.flush_cache ();
4842 :
4843 : /* Release the ranger instance and replace it with a global ranger.
4844 : Also reset the pointer since calling disable_ranger() deletes it. */
4845 5361948 : disable_ranger (fun);
4846 5361948 : m_ptr_qry.rvals = NULL;
4847 :
4848 5361948 : m_clobbers.empty ();
4849 5361948 : m_bb_uids_set = NULL;
4850 :
4851 5361948 : free_dominance_info (CDI_POST_DOMINATORS);
4852 5361948 : free_dominance_info (CDI_DOMINATORS);
4853 5361948 : return 0;
4854 5361948 : }
4855 :
4856 : } // namespace
4857 :
4858 : /* Return a new instance of the pass. */
4859 :
4860 : gimple_opt_pass *
4861 285722 : make_pass_warn_access (gcc::context *ctxt)
4862 : {
4863 285722 : return new pass_waccess (ctxt);
4864 : }
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