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Commit | Line | Data |
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2a837de2 MS |
1 | /* Pass to detect and issue warnings for invalid accesses, including |
2 | invalid or mismatched allocation/deallocation calls. | |
3 | ||
aeee4812 | 4 | Copyright (C) 2020-2023 Free Software Foundation, Inc. |
2a837de2 MS |
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 | ||
b48d4e68 | 23 | #define INCLUDE_STRING |
2a837de2 MS |
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" | |
5a431b60 | 32 | #include "diagnostic.h" |
2a837de2 MS |
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" | |
2a837de2 | 39 | #include "gimple-iterator.h" |
ba206889 | 40 | #include "gimple-fold.h" |
b48d4e68 | 41 | #include "langhooks.h" |
5a431b60 MS |
42 | #include "memmodel.h" |
43 | #include "target.h" | |
2a837de2 MS |
44 | #include "tree-dfa.h" |
45 | #include "tree-ssa.h" | |
46 | #include "tree-cfg.h" | |
47 | #include "tree-object-size.h" | |
81d6cdd3 | 48 | #include "tree-ssa-strlen.h" |
2a837de2 | 49 | #include "calls.h" |
51149a05 | 50 | #include "cfganal.h" |
2a837de2 MS |
51 | #include "intl.h" |
52 | #include "gimple-range.h" | |
53 | #include "stringpool.h" | |
54 | #include "attribs.h" | |
55 | #include "demangle.h" | |
671a2836 | 56 | #include "attr-fnspec.h" |
2a837de2 MS |
57 | #include "pointer-query.h" |
58 | ||
81d6cdd3 MS |
59 | /* Return true if tree node X has an associated location. */ |
60 | ||
61 | static inline location_t | |
62 | has_location (const_tree x) | |
63 | { | |
64 | if (DECL_P (x)) | |
65 | return DECL_SOURCE_LOCATION (x) != UNKNOWN_LOCATION; | |
66 | ||
67 | if (EXPR_P (x)) | |
68 | return EXPR_HAS_LOCATION (x); | |
69 | ||
70 | return false; | |
71 | } | |
72 | ||
73 | /* Return the associated location of STMT. */ | |
74 | ||
75 | static inline location_t | |
76 | get_location (const gimple *stmt) | |
77 | { | |
78 | return gimple_location (stmt); | |
79 | } | |
80 | ||
81 | /* Return the associated location of tree node X. */ | |
82 | ||
83 | static inline location_t | |
84 | get_location (tree x) | |
85 | { | |
86 | if (DECL_P (x)) | |
87 | return DECL_SOURCE_LOCATION (x); | |
88 | ||
89 | if (EXPR_P (x)) | |
90 | return EXPR_LOCATION (x); | |
91 | ||
92 | return UNKNOWN_LOCATION; | |
93 | } | |
94 | ||
95 | /* Overload of the nascent tree function for GIMPLE STMT. */ | |
96 | ||
97 | static inline tree | |
98 | get_callee_fndecl (const gimple *stmt) | |
99 | { | |
100 | return gimple_call_fndecl (stmt); | |
101 | } | |
102 | ||
103 | static inline unsigned | |
104 | call_nargs (const gimple *stmt) | |
105 | { | |
106 | return gimple_call_num_args (stmt); | |
107 | } | |
108 | ||
109 | static inline unsigned | |
110 | call_nargs (const_tree expr) | |
111 | { | |
112 | return call_expr_nargs (expr); | |
113 | } | |
114 | ||
115 | ||
116 | static inline tree | |
117 | call_arg (const gimple *stmt, unsigned argno) | |
118 | { | |
119 | return gimple_call_arg (stmt, argno); | |
120 | } | |
121 | ||
122 | static inline tree | |
123 | call_arg (tree expr, unsigned argno) | |
124 | { | |
125 | return CALL_EXPR_ARG (expr, argno); | |
126 | } | |
127 | ||
2a837de2 MS |
128 | /* For a call EXPR at LOC to a function FNAME that expects a string |
129 | in the argument ARG, issue a diagnostic due to it being a called | |
130 | with an argument that is a character array with no terminating | |
131 | NUL. SIZE is the EXACT size of the array, and BNDRNG the number | |
132 | of characters in which the NUL is expected. Either EXPR or FNAME | |
133 | may be null but noth both. SIZE may be null when BNDRNG is null. */ | |
134 | ||
81d6cdd3 MS |
135 | template <class GimpleOrTree> |
136 | static void | |
137 | warn_string_no_nul (location_t loc, GimpleOrTree expr, const char *fname, | |
138 | tree arg, tree decl, tree size, bool exact, | |
2a837de2 MS |
139 | const wide_int bndrng[2] /* = NULL */) |
140 | { | |
141 | const opt_code opt = OPT_Wstringop_overread; | |
142 | if ((expr && warning_suppressed_p (expr, opt)) | |
143 | || warning_suppressed_p (arg, opt)) | |
144 | return; | |
145 | ||
146 | loc = expansion_point_location_if_in_system_header (loc); | |
147 | bool warned; | |
148 | ||
4a1c20df | 149 | /* Format the bound range as a string to keep the number of messages |
2a837de2 MS |
150 | from exploding. */ |
151 | char bndstr[80]; | |
152 | *bndstr = 0; | |
153 | if (bndrng) | |
154 | { | |
155 | if (bndrng[0] == bndrng[1]) | |
156 | sprintf (bndstr, "%llu", (unsigned long long) bndrng[0].to_uhwi ()); | |
157 | else | |
158 | sprintf (bndstr, "[%llu, %llu]", | |
159 | (unsigned long long) bndrng[0].to_uhwi (), | |
160 | (unsigned long long) bndrng[1].to_uhwi ()); | |
161 | } | |
162 | ||
6ab98d8b DM |
163 | auto_diagnostic_group d; |
164 | ||
2a837de2 MS |
165 | const tree maxobjsize = max_object_size (); |
166 | const wide_int maxsiz = wi::to_wide (maxobjsize); | |
167 | if (expr) | |
168 | { | |
169 | tree func = get_callee_fndecl (expr); | |
170 | if (bndrng) | |
171 | { | |
172 | if (wi::ltu_p (maxsiz, bndrng[0])) | |
173 | warned = warning_at (loc, opt, | |
174 | "%qD specified bound %s exceeds " | |
175 | "maximum object size %E", | |
176 | func, bndstr, maxobjsize); | |
177 | else | |
178 | { | |
179 | bool maybe = wi::to_wide (size) == bndrng[0]; | |
180 | warned = warning_at (loc, opt, | |
181 | exact | |
182 | ? G_("%qD specified bound %s exceeds " | |
183 | "the size %E of unterminated array") | |
184 | : (maybe | |
185 | ? G_("%qD specified bound %s may " | |
186 | "exceed the size of at most %E " | |
187 | "of unterminated array") | |
188 | : G_("%qD specified bound %s exceeds " | |
189 | "the size of at most %E " | |
190 | "of unterminated array")), | |
191 | func, bndstr, size); | |
192 | } | |
193 | } | |
194 | else | |
195 | warned = warning_at (loc, opt, | |
196 | "%qD argument missing terminating nul", | |
197 | func); | |
198 | } | |
199 | else | |
200 | { | |
201 | if (bndrng) | |
202 | { | |
203 | if (wi::ltu_p (maxsiz, bndrng[0])) | |
204 | warned = warning_at (loc, opt, | |
205 | "%qs specified bound %s exceeds " | |
206 | "maximum object size %E", | |
207 | fname, bndstr, maxobjsize); | |
208 | else | |
209 | { | |
210 | bool maybe = wi::to_wide (size) == bndrng[0]; | |
211 | warned = warning_at (loc, opt, | |
212 | exact | |
213 | ? G_("%qs specified bound %s exceeds " | |
214 | "the size %E of unterminated array") | |
215 | : (maybe | |
216 | ? G_("%qs specified bound %s may " | |
217 | "exceed the size of at most %E " | |
218 | "of unterminated array") | |
219 | : G_("%qs specified bound %s exceeds " | |
220 | "the size of at most %E " | |
221 | "of unterminated array")), | |
222 | fname, bndstr, size); | |
223 | } | |
224 | } | |
225 | else | |
226 | warned = warning_at (loc, opt, | |
227 | "%qs argument missing terminating nul", | |
228 | fname); | |
229 | } | |
230 | ||
231 | if (warned) | |
232 | { | |
81d6cdd3 | 233 | inform (get_location (decl), |
2a837de2 MS |
234 | "referenced argument declared here"); |
235 | suppress_warning (arg, opt); | |
236 | if (expr) | |
237 | suppress_warning (expr, opt); | |
238 | } | |
239 | } | |
240 | ||
81d6cdd3 MS |
241 | void |
242 | warn_string_no_nul (location_t loc, gimple *stmt, const char *fname, | |
243 | tree arg, tree decl, tree size /* = NULL_TREE */, | |
244 | bool exact /* = false */, | |
245 | const wide_int bndrng[2] /* = NULL */) | |
246 | { | |
247 | return warn_string_no_nul<gimple *> (loc, stmt, fname, | |
248 | arg, decl, size, exact, bndrng); | |
249 | } | |
250 | ||
251 | void | |
252 | warn_string_no_nul (location_t loc, tree expr, const char *fname, | |
253 | tree arg, tree decl, tree size /* = NULL_TREE */, | |
254 | bool exact /* = false */, | |
255 | const wide_int bndrng[2] /* = NULL */) | |
256 | { | |
257 | return warn_string_no_nul<tree> (loc, expr, fname, | |
258 | arg, decl, size, exact, bndrng); | |
259 | } | |
260 | ||
261 | /* If EXP refers to an unterminated constant character array return | |
262 | the declaration of the object of which the array is a member or | |
263 | element and if SIZE is not null, set *SIZE to the size of | |
264 | the unterminated array and set *EXACT if the size is exact or | |
265 | clear it otherwise. Otherwise return null. */ | |
266 | ||
267 | tree | |
268 | unterminated_array (tree exp, tree *size /* = NULL */, bool *exact /* = NULL */) | |
269 | { | |
270 | /* C_STRLEN will return NULL and set DECL in the info | |
271 | structure if EXP references a unterminated array. */ | |
272 | c_strlen_data lendata = { }; | |
273 | tree len = c_strlen (exp, 1, &lendata); | |
274 | if (len || !lendata.minlen || !lendata.decl) | |
275 | return NULL_TREE; | |
276 | ||
277 | if (!size) | |
278 | return lendata.decl; | |
279 | ||
280 | len = lendata.minlen; | |
281 | if (lendata.off) | |
282 | { | |
283 | /* Constant offsets are already accounted for in LENDATA.MINLEN, | |
284 | but not in a SSA_NAME + CST expression. */ | |
285 | if (TREE_CODE (lendata.off) == INTEGER_CST) | |
286 | *exact = true; | |
287 | else if (TREE_CODE (lendata.off) == PLUS_EXPR | |
288 | && TREE_CODE (TREE_OPERAND (lendata.off, 1)) == INTEGER_CST) | |
289 | { | |
290 | /* Subtract the offset from the size of the array. */ | |
291 | *exact = false; | |
292 | tree temp = TREE_OPERAND (lendata.off, 1); | |
293 | temp = fold_convert (ssizetype, temp); | |
294 | len = fold_build2 (MINUS_EXPR, ssizetype, len, temp); | |
295 | } | |
296 | else | |
297 | *exact = false; | |
298 | } | |
299 | else | |
300 | *exact = true; | |
301 | ||
302 | *size = len; | |
303 | return lendata.decl; | |
304 | } | |
305 | ||
2a837de2 MS |
306 | /* For a call EXPR (which may be null) that expects a string argument |
307 | SRC as an argument, returns false if SRC is a character array with | |
308 | no terminating NUL. When nonnull, BOUND is the number of characters | |
81d6cdd3 MS |
309 | in which to expect the terminating NUL. When EXPR is nonnull also |
310 | issues a warning. */ | |
2a837de2 | 311 | |
81d6cdd3 MS |
312 | template <class GimpleOrTree> |
313 | static bool | |
314 | check_nul_terminated_array (GimpleOrTree expr, tree src, tree bound) | |
2a837de2 MS |
315 | { |
316 | /* The constant size of the array SRC points to. The actual size | |
317 | may be less of EXACT is true, but not more. */ | |
318 | tree size; | |
319 | /* True if SRC involves a non-constant offset into the array. */ | |
320 | bool exact; | |
321 | /* The unterminated constant array SRC points to. */ | |
322 | tree nonstr = unterminated_array (src, &size, &exact); | |
323 | if (!nonstr) | |
324 | return true; | |
325 | ||
326 | /* NONSTR refers to the non-nul terminated constant array and SIZE | |
327 | is the constant size of the array in bytes. EXACT is true when | |
328 | SIZE is exact. */ | |
329 | ||
330 | wide_int bndrng[2]; | |
331 | if (bound) | |
332 | { | |
45c8523d | 333 | Value_Range r (TREE_TYPE (bound)); |
2a837de2 MS |
334 | |
335 | get_global_range_query ()->range_of_expr (r, bound); | |
336 | ||
45c8523d | 337 | if (r.undefined_p () || r.varying_p ()) |
2a837de2 MS |
338 | return true; |
339 | ||
340 | bndrng[0] = r.lower_bound (); | |
341 | bndrng[1] = r.upper_bound (); | |
342 | ||
343 | if (exact) | |
344 | { | |
345 | if (wi::leu_p (bndrng[0], wi::to_wide (size))) | |
346 | return true; | |
347 | } | |
348 | else if (wi::lt_p (bndrng[0], wi::to_wide (size), UNSIGNED)) | |
349 | return true; | |
350 | } | |
351 | ||
352 | if (expr) | |
81d6cdd3 | 353 | warn_string_no_nul (get_location (expr), expr, NULL, src, nonstr, |
2a837de2 MS |
354 | size, exact, bound ? bndrng : NULL); |
355 | ||
356 | return false; | |
357 | } | |
358 | ||
81d6cdd3 MS |
359 | bool |
360 | check_nul_terminated_array (gimple *stmt, tree src, tree bound /* = NULL_TREE */) | |
361 | { | |
362 | return check_nul_terminated_array<gimple *>(stmt, src, bound); | |
363 | } | |
2a837de2 | 364 | |
81d6cdd3 MS |
365 | bool |
366 | check_nul_terminated_array (tree expr, tree src, tree bound /* = NULL_TREE */) | |
2a837de2 | 367 | { |
81d6cdd3 MS |
368 | return check_nul_terminated_array<tree>(expr, src, bound); |
369 | } | |
370 | ||
371 | /* Warn about passing a non-string array/pointer to a built-in function | |
372 | that expects a nul-terminated string argument. Returns true if | |
373 | a warning has been issued.*/ | |
374 | ||
375 | template <class GimpleOrTree> | |
376 | static bool | |
377 | maybe_warn_nonstring_arg (tree fndecl, GimpleOrTree exp) | |
378 | { | |
379 | if (!fndecl || !fndecl_built_in_p (fndecl, BUILT_IN_NORMAL)) | |
380 | return false; | |
381 | ||
382 | if (!warn_stringop_overread | |
383 | || warning_suppressed_p (exp, OPT_Wstringop_overread)) | |
384 | return false; | |
385 | ||
386 | /* Avoid clearly invalid calls (more checking done below). */ | |
387 | unsigned nargs = call_nargs (exp); | |
388 | if (!nargs) | |
389 | return false; | |
390 | ||
391 | /* The bound argument to a bounded string function like strncpy. */ | |
392 | tree bound = NULL_TREE; | |
393 | ||
394 | /* The longest known or possible string argument to one of the comparison | |
395 | functions. If the length is less than the bound it is used instead. | |
396 | Since the length is only used for warning and not for code generation | |
397 | disable strict mode in the calls to get_range_strlen below. */ | |
398 | tree maxlen = NULL_TREE; | |
399 | ||
400 | /* It's safe to call "bounded" string functions with a non-string | |
401 | argument since the functions provide an explicit bound for this | |
402 | purpose. The exception is strncat where the bound may refer to | |
403 | either the destination or the source. */ | |
404 | int fncode = DECL_FUNCTION_CODE (fndecl); | |
405 | switch (fncode) | |
406 | { | |
407 | case BUILT_IN_STRCMP: | |
408 | case BUILT_IN_STRNCMP: | |
409 | case BUILT_IN_STRNCASECMP: | |
410 | { | |
411 | /* For these, if one argument refers to one or more of a set | |
412 | of string constants or arrays of known size, determine | |
413 | the range of their known or possible lengths and use it | |
414 | conservatively as the bound for the unbounded function, | |
415 | and to adjust the range of the bound of the bounded ones. */ | |
416 | for (unsigned argno = 0; | |
417 | argno < MIN (nargs, 2) | |
418 | && !(maxlen && TREE_CODE (maxlen) == INTEGER_CST); argno++) | |
419 | { | |
420 | tree arg = call_arg (exp, argno); | |
421 | if (!get_attr_nonstring_decl (arg)) | |
422 | { | |
423 | c_strlen_data lendata = { }; | |
424 | /* Set MAXBOUND to an arbitrary non-null non-integer | |
425 | node as a request to have it set to the length of | |
426 | the longest string in a PHI. */ | |
427 | lendata.maxbound = arg; | |
428 | get_range_strlen (arg, &lendata, /* eltsize = */ 1); | |
429 | maxlen = lendata.maxbound; | |
430 | } | |
431 | } | |
432 | } | |
433 | /* Fall through. */ | |
434 | ||
435 | case BUILT_IN_STRNCAT: | |
436 | case BUILT_IN_STPNCPY: | |
437 | case BUILT_IN_STRNCPY: | |
438 | if (nargs > 2) | |
439 | bound = call_arg (exp, 2); | |
440 | break; | |
441 | ||
442 | case BUILT_IN_STRNDUP: | |
443 | if (nargs < 2) | |
444 | return false; | |
445 | bound = call_arg (exp, 1); | |
446 | break; | |
447 | ||
448 | case BUILT_IN_STRNLEN: | |
449 | { | |
450 | tree arg = call_arg (exp, 0); | |
451 | if (!get_attr_nonstring_decl (arg)) | |
452 | { | |
453 | c_strlen_data lendata = { }; | |
454 | /* Set MAXBOUND to an arbitrary non-null non-integer | |
455 | node as a request to have it set to the length of | |
456 | the longest string in a PHI. */ | |
457 | lendata.maxbound = arg; | |
458 | get_range_strlen (arg, &lendata, /* eltsize = */ 1); | |
459 | maxlen = lendata.maxbound; | |
460 | } | |
461 | if (nargs > 1) | |
462 | bound = call_arg (exp, 1); | |
463 | break; | |
464 | } | |
465 | ||
466 | default: | |
467 | break; | |
468 | } | |
469 | ||
470 | /* Determine the range of the bound argument (if specified). */ | |
471 | tree bndrng[2] = { NULL_TREE, NULL_TREE }; | |
472 | if (bound) | |
473 | { | |
474 | STRIP_NOPS (bound); | |
475 | get_size_range (bound, bndrng); | |
476 | } | |
477 | ||
478 | location_t loc = get_location (exp); | |
479 | ||
480 | if (bndrng[0]) | |
481 | { | |
482 | /* Diagnose excessive bound prior to the adjustment below and | |
483 | regardless of attribute nonstring. */ | |
484 | tree maxobjsize = max_object_size (); | |
485 | if (tree_int_cst_lt (maxobjsize, bndrng[0])) | |
2a837de2 | 486 | { |
81d6cdd3 MS |
487 | bool warned = false; |
488 | if (tree_int_cst_equal (bndrng[0], bndrng[1])) | |
489 | warned = warning_at (loc, OPT_Wstringop_overread, | |
490 | "%qD specified bound %E " | |
491 | "exceeds maximum object size %E", | |
492 | fndecl, bndrng[0], maxobjsize); | |
493 | else | |
494 | warned = warning_at (loc, OPT_Wstringop_overread, | |
495 | "%qD specified bound [%E, %E] " | |
496 | "exceeds maximum object size %E", | |
497 | fndecl, bndrng[0], bndrng[1], | |
498 | maxobjsize); | |
499 | if (warned) | |
500 | suppress_warning (exp, OPT_Wstringop_overread); | |
501 | ||
502 | return warned; | |
503 | } | |
504 | } | |
505 | ||
506 | if (maxlen && !integer_all_onesp (maxlen)) | |
507 | { | |
508 | /* Add one for the nul. */ | |
509 | maxlen = const_binop (PLUS_EXPR, TREE_TYPE (maxlen), maxlen, | |
510 | size_one_node); | |
511 | ||
512 | if (!bndrng[0]) | |
513 | { | |
514 | /* Conservatively use the upper bound of the lengths for | |
515 | both the lower and the upper bound of the operation. */ | |
516 | bndrng[0] = maxlen; | |
517 | bndrng[1] = maxlen; | |
518 | bound = void_type_node; | |
519 | } | |
520 | else if (maxlen) | |
521 | { | |
522 | /* Replace the bound on the operation with the upper bound | |
523 | of the length of the string if the latter is smaller. */ | |
524 | if (tree_int_cst_lt (maxlen, bndrng[0])) | |
525 | bndrng[0] = maxlen; | |
526 | else if (tree_int_cst_lt (maxlen, bndrng[1])) | |
527 | bndrng[1] = maxlen; | |
528 | } | |
529 | } | |
530 | ||
531 | bool any_arg_warned = false; | |
532 | /* Iterate over the built-in function's formal arguments and check | |
533 | each const char* against the actual argument. If the actual | |
534 | argument is declared attribute non-string issue a warning unless | |
535 | the argument's maximum length is bounded. */ | |
536 | function_args_iterator it; | |
537 | function_args_iter_init (&it, TREE_TYPE (fndecl)); | |
538 | ||
539 | for (unsigned argno = 0; ; ++argno, function_args_iter_next (&it)) | |
540 | { | |
541 | /* Avoid iterating past the declared argument in a call | |
542 | to function declared without a prototype. */ | |
543 | if (argno >= nargs) | |
544 | break; | |
545 | ||
546 | tree argtype = function_args_iter_cond (&it); | |
547 | if (!argtype) | |
548 | break; | |
549 | ||
550 | if (TREE_CODE (argtype) != POINTER_TYPE) | |
551 | continue; | |
552 | ||
553 | argtype = TREE_TYPE (argtype); | |
554 | ||
555 | if (TREE_CODE (argtype) != INTEGER_TYPE | |
556 | || !TYPE_READONLY (argtype)) | |
557 | continue; | |
558 | ||
559 | argtype = TYPE_MAIN_VARIANT (argtype); | |
560 | if (argtype != char_type_node) | |
561 | continue; | |
562 | ||
563 | tree callarg = call_arg (exp, argno); | |
564 | if (TREE_CODE (callarg) == ADDR_EXPR) | |
565 | callarg = TREE_OPERAND (callarg, 0); | |
566 | ||
567 | /* See if the destination is declared with attribute "nonstring". */ | |
568 | tree decl = get_attr_nonstring_decl (callarg); | |
569 | if (!decl) | |
570 | continue; | |
571 | ||
572 | /* The maximum number of array elements accessed. */ | |
573 | offset_int wibnd = 0; | |
574 | ||
575 | if (argno && fncode == BUILT_IN_STRNCAT) | |
576 | { | |
577 | /* See if the bound in strncat is derived from the length | |
578 | of the strlen of the destination (as it's expected to be). | |
579 | If so, reset BOUND and FNCODE to trigger a warning. */ | |
580 | tree dstarg = call_arg (exp, 0); | |
581 | if (is_strlen_related_p (dstarg, bound)) | |
582 | { | |
583 | /* The bound applies to the destination, not to the source, | |
584 | so reset these to trigger a warning without mentioning | |
585 | the bound. */ | |
586 | bound = NULL; | |
587 | fncode = 0; | |
588 | } | |
589 | else if (bndrng[1]) | |
590 | /* Use the upper bound of the range for strncat. */ | |
591 | wibnd = wi::to_offset (bndrng[1]); | |
592 | } | |
593 | else if (bndrng[0]) | |
594 | /* Use the lower bound of the range for functions other than | |
595 | strncat. */ | |
596 | wibnd = wi::to_offset (bndrng[0]); | |
597 | ||
598 | /* Determine the size of the argument array if it is one. */ | |
599 | offset_int asize = wibnd; | |
600 | bool known_size = false; | |
601 | tree type = TREE_TYPE (decl); | |
602 | ||
603 | /* Determine the array size. For arrays of unknown bound and | |
604 | pointers reset BOUND to trigger the appropriate warning. */ | |
605 | if (TREE_CODE (type) == ARRAY_TYPE) | |
606 | { | |
607 | if (tree arrbnd = TYPE_DOMAIN (type)) | |
2a837de2 | 608 | { |
81d6cdd3 | 609 | if ((arrbnd = TYPE_MAX_VALUE (arrbnd))) |
2a837de2 | 610 | { |
81d6cdd3 MS |
611 | asize = wi::to_offset (arrbnd) + 1; |
612 | known_size = true; | |
2a837de2 | 613 | } |
2a837de2 | 614 | } |
81d6cdd3 MS |
615 | else if (bound == void_type_node) |
616 | bound = NULL_TREE; | |
617 | } | |
618 | else if (bound == void_type_node) | |
619 | bound = NULL_TREE; | |
620 | ||
621 | /* In a call to strncat with a bound in a range whose lower but | |
622 | not upper bound is less than the array size, reset ASIZE to | |
623 | be the same as the bound and the other variable to trigger | |
4a1c20df | 624 | the appropriate warning below. */ |
81d6cdd3 MS |
625 | if (fncode == BUILT_IN_STRNCAT |
626 | && bndrng[0] != bndrng[1] | |
627 | && wi::ltu_p (wi::to_offset (bndrng[0]), asize) | |
628 | && (!known_size | |
629 | || wi::ltu_p (asize, wibnd))) | |
630 | { | |
631 | asize = wibnd; | |
632 | bound = NULL_TREE; | |
633 | fncode = 0; | |
634 | } | |
635 | ||
636 | bool warned = false; | |
637 | ||
638 | auto_diagnostic_group d; | |
639 | if (wi::ltu_p (asize, wibnd)) | |
640 | { | |
641 | if (bndrng[0] == bndrng[1]) | |
642 | warned = warning_at (loc, OPT_Wstringop_overread, | |
643 | "%qD argument %i declared attribute " | |
644 | "%<nonstring%> is smaller than the specified " | |
645 | "bound %wu", | |
646 | fndecl, argno + 1, wibnd.to_uhwi ()); | |
647 | else if (wi::ltu_p (asize, wi::to_offset (bndrng[0]))) | |
648 | warned = warning_at (loc, OPT_Wstringop_overread, | |
649 | "%qD argument %i declared attribute " | |
650 | "%<nonstring%> is smaller than " | |
651 | "the specified bound [%E, %E]", | |
652 | fndecl, argno + 1, bndrng[0], bndrng[1]); | |
2a837de2 | 653 | else |
81d6cdd3 MS |
654 | warned = warning_at (loc, OPT_Wstringop_overread, |
655 | "%qD argument %i declared attribute " | |
656 | "%<nonstring%> may be smaller than " | |
657 | "the specified bound [%E, %E]", | |
658 | fndecl, argno + 1, bndrng[0], bndrng[1]); | |
659 | } | |
660 | else if (fncode == BUILT_IN_STRNCAT) | |
661 | ; /* Avoid warning for calls to strncat() when the bound | |
662 | is equal to the size of the non-string argument. */ | |
663 | else if (!bound) | |
664 | warned = warning_at (loc, OPT_Wstringop_overread, | |
665 | "%qD argument %i declared attribute %<nonstring%>", | |
666 | fndecl, argno + 1); | |
2a837de2 | 667 | |
81d6cdd3 MS |
668 | if (warned) |
669 | { | |
670 | inform (DECL_SOURCE_LOCATION (decl), | |
671 | "argument %qD declared here", decl); | |
672 | any_arg_warned = true; | |
2a837de2 | 673 | } |
81d6cdd3 MS |
674 | } |
675 | ||
676 | if (any_arg_warned) | |
677 | suppress_warning (exp, OPT_Wstringop_overread); | |
678 | ||
679 | return any_arg_warned; | |
680 | } | |
681 | ||
682 | bool | |
683 | maybe_warn_nonstring_arg (tree fndecl, gimple *stmt) | |
684 | { | |
685 | return maybe_warn_nonstring_arg<gimple *>(fndecl, stmt); | |
686 | } | |
2a837de2 | 687 | |
81d6cdd3 MS |
688 | |
689 | bool | |
690 | maybe_warn_nonstring_arg (tree fndecl, tree expr) | |
691 | { | |
692 | return maybe_warn_nonstring_arg<tree>(fndecl, expr); | |
2a837de2 MS |
693 | } |
694 | ||
695 | /* Issue a warning OPT for a bounded call EXP with a bound in RANGE | |
696 | accessing an object with SIZE. */ | |
697 | ||
81d6cdd3 MS |
698 | template <class GimpleOrTree> |
699 | static bool | |
700 | maybe_warn_for_bound (opt_code opt, location_t loc, GimpleOrTree exp, tree func, | |
701 | tree bndrng[2], tree size, const access_data *pad) | |
2a837de2 MS |
702 | { |
703 | if (!bndrng[0] || warning_suppressed_p (exp, opt)) | |
704 | return false; | |
705 | ||
706 | tree maxobjsize = max_object_size (); | |
707 | ||
708 | bool warned = false; | |
709 | ||
710 | if (opt == OPT_Wstringop_overread) | |
711 | { | |
712 | bool maybe = pad && pad->src.phi (); | |
820f0940 MS |
713 | if (maybe) |
714 | { | |
715 | /* Issue a "maybe" warning only if the PHI refers to objects | |
716 | at least one of which has more space remaining than the bound. | |
717 | Otherwise, if the bound is greater, use the definitive form. */ | |
718 | offset_int remmax = pad->src.size_remaining (); | |
719 | if (remmax < wi::to_offset (bndrng[0])) | |
720 | maybe = false; | |
721 | } | |
2a837de2 | 722 | |
6ab98d8b | 723 | auto_diagnostic_group d; |
2a837de2 MS |
724 | if (tree_int_cst_lt (maxobjsize, bndrng[0])) |
725 | { | |
726 | if (bndrng[0] == bndrng[1]) | |
727 | warned = (func | |
728 | ? warning_at (loc, opt, | |
729 | (maybe | |
730 | ? G_("%qD specified bound %E may " | |
731 | "exceed maximum object size %E") | |
732 | : G_("%qD specified bound %E " | |
733 | "exceeds maximum object size %E")), | |
734 | func, bndrng[0], maxobjsize) | |
735 | : warning_at (loc, opt, | |
736 | (maybe | |
737 | ? G_("specified bound %E may " | |
738 | "exceed maximum object size %E") | |
739 | : G_("specified bound %E " | |
740 | "exceeds maximum object size %E")), | |
741 | bndrng[0], maxobjsize)); | |
742 | else | |
743 | warned = (func | |
744 | ? warning_at (loc, opt, | |
745 | (maybe | |
746 | ? G_("%qD specified bound [%E, %E] may " | |
747 | "exceed maximum object size %E") | |
748 | : G_("%qD specified bound [%E, %E] " | |
749 | "exceeds maximum object size %E")), | |
750 | func, | |
751 | bndrng[0], bndrng[1], maxobjsize) | |
752 | : warning_at (loc, opt, | |
753 | (maybe | |
754 | ? G_("specified bound [%E, %E] may " | |
755 | "exceed maximum object size %E") | |
756 | : G_("specified bound [%E, %E] " | |
757 | "exceeds maximum object size %E")), | |
758 | bndrng[0], bndrng[1], maxobjsize)); | |
759 | } | |
760 | else if (!size || tree_int_cst_le (bndrng[0], size)) | |
761 | return false; | |
762 | else if (tree_int_cst_equal (bndrng[0], bndrng[1])) | |
763 | warned = (func | |
764 | ? warning_at (loc, opt, | |
765 | (maybe | |
766 | ? G_("%qD specified bound %E may exceed " | |
767 | "source size %E") | |
768 | : G_("%qD specified bound %E exceeds " | |
769 | "source size %E")), | |
770 | func, bndrng[0], size) | |
771 | : warning_at (loc, opt, | |
772 | (maybe | |
773 | ? G_("specified bound %E may exceed " | |
774 | "source size %E") | |
775 | : G_("specified bound %E exceeds " | |
776 | "source size %E")), | |
777 | bndrng[0], size)); | |
778 | else | |
779 | warned = (func | |
780 | ? warning_at (loc, opt, | |
781 | (maybe | |
782 | ? G_("%qD specified bound [%E, %E] may " | |
783 | "exceed source size %E") | |
784 | : G_("%qD specified bound [%E, %E] exceeds " | |
785 | "source size %E")), | |
786 | func, bndrng[0], bndrng[1], size) | |
787 | : warning_at (loc, opt, | |
788 | (maybe | |
789 | ? G_("specified bound [%E, %E] may exceed " | |
790 | "source size %E") | |
791 | : G_("specified bound [%E, %E] exceeds " | |
792 | "source size %E")), | |
793 | bndrng[0], bndrng[1], size)); | |
794 | if (warned) | |
795 | { | |
81d6cdd3 MS |
796 | if (pad && pad->src.ref |
797 | && has_location (pad->src.ref)) | |
798 | inform (get_location (pad->src.ref), | |
799 | "source object allocated here"); | |
2a837de2 MS |
800 | suppress_warning (exp, opt); |
801 | } | |
802 | ||
803 | return warned; | |
804 | } | |
805 | ||
806 | bool maybe = pad && pad->dst.phi (); | |
820f0940 MS |
807 | if (maybe) |
808 | { | |
809 | /* Issue a "maybe" warning only if the PHI refers to objects | |
810 | at least one of which has more space remaining than the bound. | |
811 | Otherwise, if the bound is greater, use the definitive form. */ | |
812 | offset_int remmax = pad->dst.size_remaining (); | |
813 | if (remmax < wi::to_offset (bndrng[0])) | |
814 | maybe = false; | |
815 | } | |
2a837de2 MS |
816 | if (tree_int_cst_lt (maxobjsize, bndrng[0])) |
817 | { | |
818 | if (bndrng[0] == bndrng[1]) | |
819 | warned = (func | |
820 | ? warning_at (loc, opt, | |
821 | (maybe | |
822 | ? G_("%qD specified size %E may " | |
823 | "exceed maximum object size %E") | |
824 | : G_("%qD specified size %E " | |
825 | "exceeds maximum object size %E")), | |
826 | func, bndrng[0], maxobjsize) | |
827 | : warning_at (loc, opt, | |
828 | (maybe | |
829 | ? G_("specified size %E may exceed " | |
830 | "maximum object size %E") | |
831 | : G_("specified size %E exceeds " | |
832 | "maximum object size %E")), | |
833 | bndrng[0], maxobjsize)); | |
834 | else | |
835 | warned = (func | |
836 | ? warning_at (loc, opt, | |
837 | (maybe | |
838 | ? G_("%qD specified size between %E and %E " | |
839 | "may exceed maximum object size %E") | |
840 | : G_("%qD specified size between %E and %E " | |
841 | "exceeds maximum object size %E")), | |
842 | func, bndrng[0], bndrng[1], maxobjsize) | |
843 | : warning_at (loc, opt, | |
844 | (maybe | |
845 | ? G_("specified size between %E and %E " | |
846 | "may exceed maximum object size %E") | |
847 | : G_("specified size between %E and %E " | |
848 | "exceeds maximum object size %E")), | |
849 | bndrng[0], bndrng[1], maxobjsize)); | |
850 | } | |
851 | else if (!size || tree_int_cst_le (bndrng[0], size)) | |
852 | return false; | |
853 | else if (tree_int_cst_equal (bndrng[0], bndrng[1])) | |
854 | warned = (func | |
855 | ? warning_at (loc, opt, | |
856 | (maybe | |
857 | ? G_("%qD specified bound %E may exceed " | |
858 | "destination size %E") | |
859 | : G_("%qD specified bound %E exceeds " | |
860 | "destination size %E")), | |
861 | func, bndrng[0], size) | |
862 | : warning_at (loc, opt, | |
863 | (maybe | |
864 | ? G_("specified bound %E may exceed " | |
865 | "destination size %E") | |
866 | : G_("specified bound %E exceeds " | |
867 | "destination size %E")), | |
868 | bndrng[0], size)); | |
869 | else | |
870 | warned = (func | |
871 | ? warning_at (loc, opt, | |
872 | (maybe | |
873 | ? G_("%qD specified bound [%E, %E] may exceed " | |
874 | "destination size %E") | |
875 | : G_("%qD specified bound [%E, %E] exceeds " | |
876 | "destination size %E")), | |
877 | func, bndrng[0], bndrng[1], size) | |
878 | : warning_at (loc, opt, | |
879 | (maybe | |
880 | ? G_("specified bound [%E, %E] exceeds " | |
881 | "destination size %E") | |
882 | : G_("specified bound [%E, %E] exceeds " | |
883 | "destination size %E")), | |
884 | bndrng[0], bndrng[1], size)); | |
885 | ||
886 | if (warned) | |
887 | { | |
81d6cdd3 MS |
888 | if (pad && pad->dst.ref |
889 | && has_location (pad->dst.ref)) | |
890 | inform (get_location (pad->dst.ref), | |
891 | "destination object allocated here"); | |
2a837de2 MS |
892 | suppress_warning (exp, opt); |
893 | } | |
894 | ||
895 | return warned; | |
896 | } | |
897 | ||
81d6cdd3 MS |
898 | bool |
899 | maybe_warn_for_bound (opt_code opt, location_t loc, gimple *stmt, tree func, | |
900 | tree bndrng[2], tree size, | |
901 | const access_data *pad /* = NULL */) | |
902 | { | |
903 | return maybe_warn_for_bound<gimple *> (opt, loc, stmt, func, bndrng, size, | |
904 | pad); | |
905 | } | |
906 | ||
907 | bool | |
908 | maybe_warn_for_bound (opt_code opt, location_t loc, tree expr, tree func, | |
909 | tree bndrng[2], tree size, | |
910 | const access_data *pad /* = NULL */) | |
911 | { | |
912 | return maybe_warn_for_bound<tree> (opt, loc, expr, func, bndrng, size, pad); | |
913 | } | |
914 | ||
2a837de2 MS |
915 | /* For an expression EXP issue an access warning controlled by option OPT |
916 | with access to a region SIZE bytes in size in the RANGE of sizes. | |
917 | WRITE is true for a write access, READ for a read access, neither for | |
918 | call that may or may not perform an access but for which the range | |
919 | is expected to valid. | |
920 | Returns true when a warning has been issued. */ | |
921 | ||
81d6cdd3 | 922 | template <class GimpleOrTree> |
2a837de2 | 923 | static bool |
81d6cdd3 MS |
924 | warn_for_access (location_t loc, tree func, GimpleOrTree exp, int opt, |
925 | tree range[2], tree size, bool write, bool read, bool maybe) | |
2a837de2 MS |
926 | { |
927 | bool warned = false; | |
928 | ||
929 | if (write && read) | |
930 | { | |
931 | if (tree_int_cst_equal (range[0], range[1])) | |
932 | warned = (func | |
933 | ? warning_n (loc, opt, tree_to_uhwi (range[0]), | |
934 | (maybe | |
935 | ? G_("%qD may access %E byte in a region " | |
936 | "of size %E") | |
937 | : G_("%qD accessing %E byte in a region " | |
938 | "of size %E")), | |
939 | (maybe | |
940 | ? G_ ("%qD may access %E bytes in a region " | |
941 | "of size %E") | |
942 | : G_ ("%qD accessing %E bytes in a region " | |
943 | "of size %E")), | |
944 | func, range[0], size) | |
945 | : warning_n (loc, opt, tree_to_uhwi (range[0]), | |
946 | (maybe | |
947 | ? G_("may access %E byte in a region " | |
948 | "of size %E") | |
949 | : G_("accessing %E byte in a region " | |
950 | "of size %E")), | |
951 | (maybe | |
952 | ? G_("may access %E bytes in a region " | |
953 | "of size %E") | |
954 | : G_("accessing %E bytes in a region " | |
955 | "of size %E")), | |
956 | range[0], size)); | |
957 | else if (tree_int_cst_sign_bit (range[1])) | |
958 | { | |
959 | /* Avoid printing the upper bound if it's invalid. */ | |
960 | warned = (func | |
961 | ? warning_at (loc, opt, | |
962 | (maybe | |
963 | ? G_("%qD may access %E or more bytes " | |
964 | "in a region of size %E") | |
965 | : G_("%qD accessing %E or more bytes " | |
966 | "in a region of size %E")), | |
967 | func, range[0], size) | |
968 | : warning_at (loc, opt, | |
969 | (maybe | |
970 | ? G_("may access %E or more bytes " | |
971 | "in a region of size %E") | |
972 | : G_("accessing %E or more bytes " | |
973 | "in a region of size %E")), | |
974 | range[0], size)); | |
975 | } | |
976 | else | |
977 | warned = (func | |
978 | ? warning_at (loc, opt, | |
979 | (maybe | |
980 | ? G_("%qD may access between %E and %E " | |
981 | "bytes in a region of size %E") | |
982 | : G_("%qD accessing between %E and %E " | |
983 | "bytes in a region of size %E")), | |
984 | func, range[0], range[1], size) | |
985 | : warning_at (loc, opt, | |
986 | (maybe | |
987 | ? G_("may access between %E and %E bytes " | |
988 | "in a region of size %E") | |
989 | : G_("accessing between %E and %E bytes " | |
990 | "in a region of size %E")), | |
991 | range[0], range[1], size)); | |
992 | return warned; | |
993 | } | |
994 | ||
995 | if (write) | |
996 | { | |
997 | if (tree_int_cst_equal (range[0], range[1])) | |
998 | warned = (func | |
999 | ? warning_n (loc, opt, tree_to_uhwi (range[0]), | |
1000 | (maybe | |
1001 | ? G_("%qD may write %E byte into a region " | |
1002 | "of size %E") | |
1003 | : G_("%qD writing %E byte into a region " | |
1004 | "of size %E overflows the destination")), | |
1005 | (maybe | |
1006 | ? G_("%qD may write %E bytes into a region " | |
1007 | "of size %E") | |
1008 | : G_("%qD writing %E bytes into a region " | |
1009 | "of size %E overflows the destination")), | |
1010 | func, range[0], size) | |
1011 | : warning_n (loc, opt, tree_to_uhwi (range[0]), | |
1012 | (maybe | |
1013 | ? G_("may write %E byte into a region " | |
1014 | "of size %E") | |
1015 | : G_("writing %E byte into a region " | |
1016 | "of size %E overflows the destination")), | |
1017 | (maybe | |
1018 | ? G_("may write %E bytes into a region " | |
1019 | "of size %E") | |
1020 | : G_("writing %E bytes into a region " | |
1021 | "of size %E overflows the destination")), | |
1022 | range[0], size)); | |
1023 | else if (tree_int_cst_sign_bit (range[1])) | |
1024 | { | |
1025 | /* Avoid printing the upper bound if it's invalid. */ | |
1026 | warned = (func | |
1027 | ? warning_at (loc, opt, | |
1028 | (maybe | |
1029 | ? G_("%qD may write %E or more bytes " | |
1030 | "into a region of size %E") | |
1031 | : G_("%qD writing %E or more bytes " | |
1032 | "into a region of size %E overflows " | |
1033 | "the destination")), | |
1034 | func, range[0], size) | |
1035 | : warning_at (loc, opt, | |
1036 | (maybe | |
1037 | ? G_("may write %E or more bytes into " | |
1038 | "a region of size %E") | |
1039 | : G_("writing %E or more bytes into " | |
1040 | "a region of size %E overflows " | |
1041 | "the destination")), | |
1042 | range[0], size)); | |
1043 | } | |
1044 | else | |
1045 | warned = (func | |
1046 | ? warning_at (loc, opt, | |
1047 | (maybe | |
1048 | ? G_("%qD may write between %E and %E bytes " | |
1049 | "into a region of size %E") | |
1050 | : G_("%qD writing between %E and %E bytes " | |
1051 | "into a region of size %E overflows " | |
1052 | "the destination")), | |
1053 | func, range[0], range[1], size) | |
1054 | : warning_at (loc, opt, | |
1055 | (maybe | |
1056 | ? G_("may write between %E and %E bytes " | |
1057 | "into a region of size %E") | |
1058 | : G_("writing between %E and %E bytes " | |
1059 | "into a region of size %E overflows " | |
1060 | "the destination")), | |
1061 | range[0], range[1], size)); | |
1062 | return warned; | |
1063 | } | |
1064 | ||
1065 | if (read) | |
1066 | { | |
1067 | if (tree_int_cst_equal (range[0], range[1])) | |
1068 | warned = (func | |
1069 | ? warning_n (loc, OPT_Wstringop_overread, | |
1070 | tree_to_uhwi (range[0]), | |
1071 | (maybe | |
1072 | ? G_("%qD may read %E byte from a region " | |
1073 | "of size %E") | |
1074 | : G_("%qD reading %E byte from a region " | |
1075 | "of size %E")), | |
1076 | (maybe | |
1077 | ? G_("%qD may read %E bytes from a region " | |
1078 | "of size %E") | |
1079 | : G_("%qD reading %E bytes from a region " | |
1080 | "of size %E")), | |
1081 | func, range[0], size) | |
1082 | : warning_n (loc, OPT_Wstringop_overread, | |
1083 | tree_to_uhwi (range[0]), | |
1084 | (maybe | |
1085 | ? G_("may read %E byte from a region " | |
1086 | "of size %E") | |
1087 | : G_("reading %E byte from a region " | |
1088 | "of size %E")), | |
1089 | (maybe | |
1090 | ? G_("may read %E bytes from a region " | |
1091 | "of size %E") | |
1092 | : G_("reading %E bytes from a region " | |
1093 | "of size %E")), | |
1094 | range[0], size)); | |
1095 | else if (tree_int_cst_sign_bit (range[1])) | |
1096 | { | |
1097 | /* Avoid printing the upper bound if it's invalid. */ | |
1098 | warned = (func | |
1099 | ? warning_at (loc, OPT_Wstringop_overread, | |
1100 | (maybe | |
1101 | ? G_("%qD may read %E or more bytes " | |
1102 | "from a region of size %E") | |
1103 | : G_("%qD reading %E or more bytes " | |
1104 | "from a region of size %E")), | |
1105 | func, range[0], size) | |
1106 | : warning_at (loc, OPT_Wstringop_overread, | |
1107 | (maybe | |
1108 | ? G_("may read %E or more bytes " | |
1109 | "from a region of size %E") | |
1110 | : G_("reading %E or more bytes " | |
1111 | "from a region of size %E")), | |
1112 | range[0], size)); | |
1113 | } | |
1114 | else | |
1115 | warned = (func | |
1116 | ? warning_at (loc, OPT_Wstringop_overread, | |
1117 | (maybe | |
1118 | ? G_("%qD may read between %E and %E bytes " | |
1119 | "from a region of size %E") | |
1120 | : G_("%qD reading between %E and %E bytes " | |
1121 | "from a region of size %E")), | |
1122 | func, range[0], range[1], size) | |
1123 | : warning_at (loc, opt, | |
1124 | (maybe | |
1125 | ? G_("may read between %E and %E bytes " | |
1126 | "from a region of size %E") | |
1127 | : G_("reading between %E and %E bytes " | |
1128 | "from a region of size %E")), | |
1129 | range[0], range[1], size)); | |
1130 | ||
1131 | if (warned) | |
1132 | suppress_warning (exp, OPT_Wstringop_overread); | |
1133 | ||
1134 | return warned; | |
1135 | } | |
1136 | ||
1137 | if (tree_int_cst_equal (range[0], range[1]) | |
1138 | || tree_int_cst_sign_bit (range[1])) | |
1139 | warned = (func | |
1140 | ? warning_n (loc, OPT_Wstringop_overread, | |
1141 | tree_to_uhwi (range[0]), | |
1142 | "%qD expecting %E byte in a region of size %E", | |
1143 | "%qD expecting %E bytes in a region of size %E", | |
1144 | func, range[0], size) | |
1145 | : warning_n (loc, OPT_Wstringop_overread, | |
1146 | tree_to_uhwi (range[0]), | |
1147 | "expecting %E byte in a region of size %E", | |
1148 | "expecting %E bytes in a region of size %E", | |
1149 | range[0], size)); | |
1150 | else if (tree_int_cst_sign_bit (range[1])) | |
1151 | { | |
1152 | /* Avoid printing the upper bound if it's invalid. */ | |
1153 | warned = (func | |
1154 | ? warning_at (loc, OPT_Wstringop_overread, | |
1155 | "%qD expecting %E or more bytes in a region " | |
1156 | "of size %E", | |
1157 | func, range[0], size) | |
1158 | : warning_at (loc, OPT_Wstringop_overread, | |
1159 | "expecting %E or more bytes in a region " | |
1160 | "of size %E", | |
1161 | range[0], size)); | |
1162 | } | |
1163 | else | |
1164 | warned = (func | |
1165 | ? warning_at (loc, OPT_Wstringop_overread, | |
1166 | "%qD expecting between %E and %E bytes in " | |
1167 | "a region of size %E", | |
1168 | func, range[0], range[1], size) | |
1169 | : warning_at (loc, OPT_Wstringop_overread, | |
1170 | "expecting between %E and %E bytes in " | |
1171 | "a region of size %E", | |
1172 | range[0], range[1], size)); | |
1173 | ||
1174 | if (warned) | |
1175 | suppress_warning (exp, OPT_Wstringop_overread); | |
1176 | ||
1177 | return warned; | |
1178 | } | |
1179 | ||
81d6cdd3 MS |
1180 | static bool |
1181 | warn_for_access (location_t loc, tree func, gimple *stmt, int opt, | |
1182 | tree range[2], tree size, bool write, bool read, bool maybe) | |
1183 | { | |
1184 | return warn_for_access<gimple *>(loc, func, stmt, opt, range, size, | |
1185 | write, read, maybe); | |
1186 | } | |
1187 | ||
1188 | static bool | |
1189 | warn_for_access (location_t loc, tree func, tree expr, int opt, | |
1190 | tree range[2], tree size, bool write, bool read, bool maybe) | |
1191 | { | |
1192 | return warn_for_access<tree>(loc, func, expr, opt, range, size, | |
1193 | write, read, maybe); | |
1194 | } | |
1195 | ||
2a837de2 MS |
1196 | /* Helper to set RANGE to the range of BOUND if it's nonnull, bounded |
1197 | by BNDRNG if nonnull and valid. */ | |
1198 | ||
b48d4e68 | 1199 | static void |
9a27acc3 | 1200 | get_size_range (range_query *query, tree bound, gimple *stmt, tree range[2], |
ece28da9 | 1201 | const offset_int bndrng[2]) |
2a837de2 MS |
1202 | { |
1203 | if (bound) | |
9a27acc3 | 1204 | get_size_range (query, bound, stmt, range); |
2a837de2 MS |
1205 | |
1206 | if (!bndrng || (bndrng[0] == 0 && bndrng[1] == HOST_WIDE_INT_M1U)) | |
1207 | return; | |
1208 | ||
1209 | if (range[0] && TREE_CODE (range[0]) == INTEGER_CST) | |
1210 | { | |
1211 | offset_int r[] = | |
1212 | { wi::to_offset (range[0]), wi::to_offset (range[1]) }; | |
1213 | if (r[0] < bndrng[0]) | |
1214 | range[0] = wide_int_to_tree (sizetype, bndrng[0]); | |
1215 | if (bndrng[1] < r[1]) | |
1216 | range[1] = wide_int_to_tree (sizetype, bndrng[1]); | |
1217 | } | |
1218 | else | |
1219 | { | |
1220 | range[0] = wide_int_to_tree (sizetype, bndrng[0]); | |
1221 | range[1] = wide_int_to_tree (sizetype, bndrng[1]); | |
1222 | } | |
1223 | } | |
1224 | ||
1225 | /* Try to verify that the sizes and lengths of the arguments to a string | |
1226 | manipulation function given by EXP are within valid bounds and that | |
1227 | the operation does not lead to buffer overflow or read past the end. | |
1228 | Arguments other than EXP may be null. When non-null, the arguments | |
1229 | have the following meaning: | |
1230 | DST is the destination of a copy call or NULL otherwise. | |
1231 | SRC is the source of a copy call or NULL otherwise. | |
1232 | DSTWRITE is the number of bytes written into the destination obtained | |
1233 | from the user-supplied size argument to the function (such as in | |
1234 | memcpy(DST, SRCs, DSTWRITE) or strncpy(DST, DRC, DSTWRITE). | |
1235 | MAXREAD is the user-supplied bound on the length of the source sequence | |
1236 | (such as in strncat(d, s, N). It specifies the upper limit on the number | |
1237 | of bytes to write. If NULL, it's taken to be the same as DSTWRITE. | |
1238 | SRCSTR is the source string (such as in strcpy(DST, SRC)) when the | |
1239 | expression EXP is a string function call (as opposed to a memory call | |
1240 | like memcpy). As an exception, SRCSTR can also be an integer denoting | |
1241 | the precomputed size of the source string or object (for functions like | |
1242 | memcpy). | |
1243 | DSTSIZE is the size of the destination object. | |
1244 | ||
1245 | When DSTWRITE is null LEN is checked to verify that it doesn't exceed | |
1246 | SIZE_MAX. | |
1247 | ||
1248 | WRITE is true for write accesses, READ is true for reads. Both are | |
1249 | false for simple size checks in calls to functions that neither read | |
1250 | from nor write to the region. | |
1251 | ||
1252 | When nonnull, PAD points to a more detailed description of the access. | |
1253 | ||
1254 | If the call is successfully verified as safe return true, otherwise | |
1255 | return false. */ | |
1256 | ||
81d6cdd3 MS |
1257 | template <class GimpleOrTree> |
1258 | static bool | |
1259 | check_access (GimpleOrTree exp, tree dstwrite, | |
2a837de2 | 1260 | tree maxread, tree srcstr, tree dstsize, |
9a27acc3 MS |
1261 | access_mode mode, const access_data *pad, |
1262 | range_query *rvals) | |
2a837de2 MS |
1263 | { |
1264 | /* The size of the largest object is half the address space, or | |
1265 | PTRDIFF_MAX. (This is way too permissive.) */ | |
1266 | tree maxobjsize = max_object_size (); | |
1267 | ||
1268 | /* Either an approximate/minimum the length of the source string for | |
1269 | string functions or the size of the source object for raw memory | |
1270 | functions. */ | |
1271 | tree slen = NULL_TREE; | |
1272 | ||
1273 | /* The range of the access in bytes; first set to the write access | |
1274 | for functions that write and then read for those that also (or | |
1275 | just) read. */ | |
1276 | tree range[2] = { NULL_TREE, NULL_TREE }; | |
1277 | ||
1278 | /* Set to true when the exact number of bytes written by a string | |
1279 | function like strcpy is not known and the only thing that is | |
1280 | known is that it must be at least one (for the terminating nul). */ | |
1281 | bool at_least_one = false; | |
1282 | if (srcstr) | |
1283 | { | |
1284 | /* SRCSTR is normally a pointer to string but as a special case | |
1285 | it can be an integer denoting the length of a string. */ | |
1286 | if (POINTER_TYPE_P (TREE_TYPE (srcstr))) | |
1287 | { | |
1288 | if (!check_nul_terminated_array (exp, srcstr, maxread)) | |
81d6cdd3 MS |
1289 | /* Return if the array is not nul-terminated and a warning |
1290 | has been issued. */ | |
2a837de2 | 1291 | return false; |
81d6cdd3 | 1292 | |
2a837de2 MS |
1293 | /* Try to determine the range of lengths the source string |
1294 | refers to. If it can be determined and is less than | |
1295 | the upper bound given by MAXREAD add one to it for | |
1296 | the terminating nul. Otherwise, set it to one for | |
1297 | the same reason, or to MAXREAD as appropriate. */ | |
1298 | c_strlen_data lendata = { }; | |
1299 | get_range_strlen (srcstr, &lendata, /* eltsize = */ 1); | |
1300 | range[0] = lendata.minlen; | |
1301 | range[1] = lendata.maxbound ? lendata.maxbound : lendata.maxlen; | |
1302 | if (range[0] | |
1303 | && TREE_CODE (range[0]) == INTEGER_CST | |
1304 | && TREE_CODE (range[1]) == INTEGER_CST | |
1305 | && (!maxread || TREE_CODE (maxread) == INTEGER_CST)) | |
1306 | { | |
1307 | if (maxread && tree_int_cst_le (maxread, range[0])) | |
1308 | range[0] = range[1] = maxread; | |
1309 | else | |
1310 | range[0] = fold_build2 (PLUS_EXPR, size_type_node, | |
1311 | range[0], size_one_node); | |
1312 | ||
1313 | if (maxread && tree_int_cst_le (maxread, range[1])) | |
1314 | range[1] = maxread; | |
1315 | else if (!integer_all_onesp (range[1])) | |
1316 | range[1] = fold_build2 (PLUS_EXPR, size_type_node, | |
1317 | range[1], size_one_node); | |
1318 | ||
1319 | slen = range[0]; | |
1320 | } | |
1321 | else | |
1322 | { | |
1323 | at_least_one = true; | |
1324 | slen = size_one_node; | |
1325 | } | |
1326 | } | |
1327 | else | |
1328 | slen = srcstr; | |
1329 | } | |
1330 | ||
1331 | if (!dstwrite && !maxread) | |
1332 | { | |
1333 | /* When the only available piece of data is the object size | |
1334 | there is nothing to do. */ | |
1335 | if (!slen) | |
1336 | return true; | |
1337 | ||
1338 | /* Otherwise, when the length of the source sequence is known | |
1339 | (as with strlen), set DSTWRITE to it. */ | |
1340 | if (!range[0]) | |
1341 | dstwrite = slen; | |
1342 | } | |
1343 | ||
1344 | if (!dstsize) | |
1345 | dstsize = maxobjsize; | |
1346 | ||
f9379fcb | 1347 | /* Set RANGE to that of DSTWRITE if non-null, bounded by PAD->DST_BNDRNG |
2a837de2 | 1348 | if valid. */ |
9a27acc3 | 1349 | gimple *stmt = pad ? pad->stmt : nullptr; |
f9379fcb | 1350 | get_size_range (rvals, dstwrite, stmt, range, pad ? pad->dst_bndrng : NULL); |
2a837de2 MS |
1351 | |
1352 | tree func = get_callee_fndecl (exp); | |
1353 | /* Read vs write access by built-ins can be determined from the const | |
1354 | qualifiers on the pointer argument. In the absence of attribute | |
1355 | access, non-const qualified pointer arguments to user-defined | |
1356 | functions are assumed to both read and write the objects. */ | |
1357 | const bool builtin = func ? fndecl_built_in_p (func) : false; | |
1358 | ||
1359 | /* First check the number of bytes to be written against the maximum | |
1360 | object size. */ | |
1361 | if (range[0] | |
1362 | && TREE_CODE (range[0]) == INTEGER_CST | |
1363 | && tree_int_cst_lt (maxobjsize, range[0])) | |
1364 | { | |
81d6cdd3 | 1365 | location_t loc = get_location (exp); |
2a837de2 MS |
1366 | maybe_warn_for_bound (OPT_Wstringop_overflow_, loc, exp, func, range, |
1367 | NULL_TREE, pad); | |
1368 | return false; | |
1369 | } | |
1370 | ||
1371 | /* The number of bytes to write is "exact" if DSTWRITE is non-null, | |
1372 | constant, and in range of unsigned HOST_WIDE_INT. */ | |
1373 | bool exactwrite = dstwrite && tree_fits_uhwi_p (dstwrite); | |
1374 | ||
1375 | /* Next check the number of bytes to be written against the destination | |
1376 | object size. */ | |
1377 | if (range[0] || !exactwrite || integer_all_onesp (dstwrite)) | |
1378 | { | |
1379 | if (range[0] | |
1380 | && TREE_CODE (range[0]) == INTEGER_CST | |
1381 | && ((tree_fits_uhwi_p (dstsize) | |
1382 | && tree_int_cst_lt (dstsize, range[0])) | |
1383 | || (dstwrite | |
1384 | && tree_fits_uhwi_p (dstwrite) | |
1385 | && tree_int_cst_lt (dstwrite, range[0])))) | |
1386 | { | |
1387 | const opt_code opt = OPT_Wstringop_overflow_; | |
1388 | if (warning_suppressed_p (exp, opt) | |
1389 | || (pad && pad->dst.ref | |
1390 | && warning_suppressed_p (pad->dst.ref, opt))) | |
1391 | return false; | |
1392 | ||
6ab98d8b | 1393 | auto_diagnostic_group d; |
81d6cdd3 | 1394 | location_t loc = get_location (exp); |
2a837de2 MS |
1395 | bool warned = false; |
1396 | if (dstwrite == slen && at_least_one) | |
1397 | { | |
1398 | /* This is a call to strcpy with a destination of 0 size | |
1399 | and a source of unknown length. The call will write | |
1400 | at least one byte past the end of the destination. */ | |
1401 | warned = (func | |
1402 | ? warning_at (loc, opt, | |
1403 | "%qD writing %E or more bytes into " | |
1404 | "a region of size %E overflows " | |
1405 | "the destination", | |
1406 | func, range[0], dstsize) | |
1407 | : warning_at (loc, opt, | |
1408 | "writing %E or more bytes into " | |
1409 | "a region of size %E overflows " | |
1410 | "the destination", | |
1411 | range[0], dstsize)); | |
1412 | } | |
1413 | else | |
1414 | { | |
1415 | const bool read | |
1416 | = mode == access_read_only || mode == access_read_write; | |
1417 | const bool write | |
1418 | = mode == access_write_only || mode == access_read_write; | |
1419 | const bool maybe = pad && pad->dst.parmarray; | |
1420 | warned = warn_for_access (loc, func, exp, | |
1421 | OPT_Wstringop_overflow_, | |
1422 | range, dstsize, | |
1423 | write, read && !builtin, maybe); | |
1424 | } | |
1425 | ||
1426 | if (warned) | |
1427 | { | |
1428 | suppress_warning (exp, OPT_Wstringop_overflow_); | |
1429 | if (pad) | |
1430 | pad->dst.inform_access (pad->mode); | |
1431 | } | |
1432 | ||
1433 | /* Return error when an overflow has been detected. */ | |
1434 | return false; | |
1435 | } | |
1436 | } | |
1437 | ||
1438 | /* Check the maximum length of the source sequence against the size | |
1439 | of the destination object if known, or against the maximum size | |
1440 | of an object. */ | |
1441 | if (maxread) | |
1442 | { | |
f9379fcb | 1443 | /* Set RANGE to that of MAXREAD, bounded by PAD->SRC_BNDRNG if |
2a837de2 | 1444 | PAD is nonnull and BNDRNG is valid. */ |
f9379fcb | 1445 | get_size_range (rvals, maxread, stmt, range, pad ? pad->src_bndrng : NULL); |
2a837de2 | 1446 | |
81d6cdd3 | 1447 | location_t loc = get_location (exp); |
2a837de2 MS |
1448 | tree size = dstsize; |
1449 | if (pad && pad->mode == access_read_only) | |
820f0940 | 1450 | size = wide_int_to_tree (sizetype, pad->src.size_remaining ()); |
2a837de2 MS |
1451 | |
1452 | if (range[0] && maxread && tree_fits_uhwi_p (size)) | |
1453 | { | |
1454 | if (tree_int_cst_lt (maxobjsize, range[0])) | |
1455 | { | |
1456 | maybe_warn_for_bound (OPT_Wstringop_overread, loc, exp, func, | |
1457 | range, size, pad); | |
1458 | return false; | |
1459 | } | |
1460 | ||
1461 | if (size != maxobjsize && tree_int_cst_lt (size, range[0])) | |
1462 | { | |
1463 | opt_code opt = (dstwrite || mode != access_read_only | |
1464 | ? OPT_Wstringop_overflow_ | |
1465 | : OPT_Wstringop_overread); | |
1466 | maybe_warn_for_bound (opt, loc, exp, func, range, size, pad); | |
1467 | return false; | |
1468 | } | |
1469 | } | |
1470 | ||
1471 | maybe_warn_nonstring_arg (func, exp); | |
1472 | } | |
1473 | ||
1474 | /* Check for reading past the end of SRC. */ | |
1475 | bool overread = (slen | |
1476 | && slen == srcstr | |
1477 | && dstwrite | |
1478 | && range[0] | |
1479 | && TREE_CODE (slen) == INTEGER_CST | |
1480 | && tree_int_cst_lt (slen, range[0])); | |
1481 | /* If none is determined try to get a better answer based on the details | |
1482 | in PAD. */ | |
1483 | if (!overread | |
1484 | && pad | |
1485 | && pad->src.sizrng[1] >= 0 | |
1486 | && pad->src.offrng[0] >= 0 | |
1487 | && (pad->src.offrng[1] < 0 | |
1488 | || pad->src.offrng[0] <= pad->src.offrng[1])) | |
1489 | { | |
f9379fcb | 1490 | /* Set RANGE to that of MAXREAD, bounded by PAD->SRC_BNDRNG if |
2a837de2 | 1491 | PAD is nonnull and BNDRNG is valid. */ |
f9379fcb | 1492 | get_size_range (rvals, maxread, stmt, range, pad ? pad->src_bndrng : NULL); |
2a837de2 | 1493 | /* Set OVERREAD for reads starting just past the end of an object. */ |
f9379fcb MS |
1494 | overread = pad->src.sizrng[1] - pad->src.offrng[0] < pad->src_bndrng[0]; |
1495 | range[0] = wide_int_to_tree (sizetype, pad->src_bndrng[0]); | |
2a837de2 MS |
1496 | slen = size_zero_node; |
1497 | } | |
1498 | ||
1499 | if (overread) | |
1500 | { | |
1501 | const opt_code opt = OPT_Wstringop_overread; | |
1502 | if (warning_suppressed_p (exp, opt) | |
1503 | || (srcstr && warning_suppressed_p (srcstr, opt)) | |
1504 | || (pad && pad->src.ref | |
1505 | && warning_suppressed_p (pad->src.ref, opt))) | |
1506 | return false; | |
1507 | ||
81d6cdd3 | 1508 | location_t loc = get_location (exp); |
2a837de2 MS |
1509 | const bool read |
1510 | = mode == access_read_only || mode == access_read_write; | |
1511 | const bool maybe = pad && pad->dst.parmarray; | |
6ab98d8b | 1512 | auto_diagnostic_group d; |
2a837de2 MS |
1513 | if (warn_for_access (loc, func, exp, opt, range, slen, false, read, |
1514 | maybe)) | |
1515 | { | |
1516 | suppress_warning (exp, opt); | |
1517 | if (pad) | |
1518 | pad->src.inform_access (access_read_only); | |
1519 | } | |
1520 | return false; | |
1521 | } | |
1522 | ||
1523 | return true; | |
1524 | } | |
1525 | ||
9a27acc3 | 1526 | static bool |
81d6cdd3 MS |
1527 | check_access (gimple *stmt, tree dstwrite, |
1528 | tree maxread, tree srcstr, tree dstsize, | |
9a27acc3 MS |
1529 | access_mode mode, const access_data *pad, |
1530 | range_query *rvals) | |
81d6cdd3 | 1531 | { |
9a27acc3 MS |
1532 | return check_access<gimple *> (stmt, dstwrite, maxread, srcstr, dstsize, |
1533 | mode, pad, rvals); | |
81d6cdd3 MS |
1534 | } |
1535 | ||
1536 | bool | |
1537 | check_access (tree expr, tree dstwrite, | |
1538 | tree maxread, tree srcstr, tree dstsize, | |
1539 | access_mode mode, const access_data *pad /* = NULL */) | |
1540 | { | |
9a27acc3 MS |
1541 | return check_access<tree> (expr, dstwrite, maxread, srcstr, dstsize, |
1542 | mode, pad, nullptr); | |
81d6cdd3 MS |
1543 | } |
1544 | ||
2a837de2 | 1545 | /* Return true if STMT is a call to an allocation function. Unless |
4a1c20df | 1546 | ALL_ALLOC is set, consider only functions that return dynamically |
2a837de2 MS |
1547 | allocated objects. Otherwise return true even for all forms of |
1548 | alloca (including VLA). */ | |
1549 | ||
1550 | static bool | |
1551 | fndecl_alloc_p (tree fndecl, bool all_alloc) | |
1552 | { | |
1553 | if (!fndecl) | |
1554 | return false; | |
1555 | ||
1556 | /* A call to operator new isn't recognized as one to a built-in. */ | |
1557 | if (DECL_IS_OPERATOR_NEW_P (fndecl)) | |
1558 | return true; | |
1559 | ||
1560 | if (fndecl_built_in_p (fndecl, BUILT_IN_NORMAL)) | |
1561 | { | |
1562 | switch (DECL_FUNCTION_CODE (fndecl)) | |
1563 | { | |
1564 | case BUILT_IN_ALLOCA: | |
1565 | case BUILT_IN_ALLOCA_WITH_ALIGN: | |
1566 | return all_alloc; | |
1567 | case BUILT_IN_ALIGNED_ALLOC: | |
1568 | case BUILT_IN_CALLOC: | |
1569 | case BUILT_IN_GOMP_ALLOC: | |
1570 | case BUILT_IN_MALLOC: | |
1571 | case BUILT_IN_REALLOC: | |
1572 | case BUILT_IN_STRDUP: | |
1573 | case BUILT_IN_STRNDUP: | |
1574 | return true; | |
1575 | default: | |
1576 | break; | |
1577 | } | |
1578 | } | |
1579 | ||
1580 | /* A function is considered an allocation function if it's declared | |
1581 | with attribute malloc with an argument naming its associated | |
1582 | deallocation function. */ | |
1583 | tree attrs = DECL_ATTRIBUTES (fndecl); | |
1584 | if (!attrs) | |
1585 | return false; | |
1586 | ||
1587 | for (tree allocs = attrs; | |
1588 | (allocs = lookup_attribute ("malloc", allocs)); | |
1589 | allocs = TREE_CHAIN (allocs)) | |
1590 | { | |
1591 | tree args = TREE_VALUE (allocs); | |
1592 | if (!args) | |
1593 | continue; | |
1594 | ||
1595 | if (TREE_VALUE (args)) | |
1596 | return true; | |
1597 | } | |
1598 | ||
1599 | return false; | |
1600 | } | |
1601 | ||
1602 | /* Return true if STMT is a call to an allocation function. A wrapper | |
1603 | around fndecl_alloc_p. */ | |
1604 | ||
1605 | static bool | |
1606 | gimple_call_alloc_p (gimple *stmt, bool all_alloc = false) | |
1607 | { | |
1608 | return fndecl_alloc_p (gimple_call_fndecl (stmt), all_alloc); | |
1609 | } | |
1610 | ||
1611 | /* Return true if DELC doesn't refer to an operator delete that's | |
1612 | suitable to call with a pointer returned from the operator new | |
1613 | described by NEWC. */ | |
1614 | ||
1615 | static bool | |
1616 | new_delete_mismatch_p (const demangle_component &newc, | |
1617 | const demangle_component &delc) | |
1618 | { | |
1619 | if (newc.type != delc.type) | |
1620 | return true; | |
1621 | ||
1622 | switch (newc.type) | |
1623 | { | |
1624 | case DEMANGLE_COMPONENT_NAME: | |
1625 | { | |
1626 | int len = newc.u.s_name.len; | |
1627 | const char *news = newc.u.s_name.s; | |
1628 | const char *dels = delc.u.s_name.s; | |
1629 | if (len != delc.u.s_name.len || memcmp (news, dels, len)) | |
1630 | return true; | |
1631 | ||
1632 | if (news[len] == 'n') | |
1633 | { | |
1634 | if (news[len + 1] == 'a') | |
1635 | return dels[len] != 'd' || dels[len + 1] != 'a'; | |
1636 | if (news[len + 1] == 'w') | |
1637 | return dels[len] != 'd' || dels[len + 1] != 'l'; | |
1638 | } | |
1639 | return false; | |
1640 | } | |
1641 | ||
1642 | case DEMANGLE_COMPONENT_OPERATOR: | |
1643 | /* Operator mismatches are handled above. */ | |
1644 | return false; | |
1645 | ||
1646 | case DEMANGLE_COMPONENT_EXTENDED_OPERATOR: | |
1647 | if (newc.u.s_extended_operator.args != delc.u.s_extended_operator.args) | |
1648 | return true; | |
1649 | return new_delete_mismatch_p (*newc.u.s_extended_operator.name, | |
1650 | *delc.u.s_extended_operator.name); | |
1651 | ||
1652 | case DEMANGLE_COMPONENT_FIXED_TYPE: | |
1653 | if (newc.u.s_fixed.accum != delc.u.s_fixed.accum | |
1654 | || newc.u.s_fixed.sat != delc.u.s_fixed.sat) | |
1655 | return true; | |
1656 | return new_delete_mismatch_p (*newc.u.s_fixed.length, | |
1657 | *delc.u.s_fixed.length); | |
1658 | ||
1659 | case DEMANGLE_COMPONENT_CTOR: | |
1660 | if (newc.u.s_ctor.kind != delc.u.s_ctor.kind) | |
1661 | return true; | |
1662 | return new_delete_mismatch_p (*newc.u.s_ctor.name, | |
1663 | *delc.u.s_ctor.name); | |
1664 | ||
1665 | case DEMANGLE_COMPONENT_DTOR: | |
1666 | if (newc.u.s_dtor.kind != delc.u.s_dtor.kind) | |
1667 | return true; | |
1668 | return new_delete_mismatch_p (*newc.u.s_dtor.name, | |
1669 | *delc.u.s_dtor.name); | |
1670 | ||
1671 | case DEMANGLE_COMPONENT_BUILTIN_TYPE: | |
1672 | { | |
1673 | /* The demangler API provides no better way to compare built-in | |
1674 | types except to by comparing their demangled names. */ | |
1675 | size_t nsz, dsz; | |
1676 | demangle_component *pnc = const_cast<demangle_component *>(&newc); | |
1677 | demangle_component *pdc = const_cast<demangle_component *>(&delc); | |
1678 | char *nts = cplus_demangle_print (0, pnc, 16, &nsz); | |
1679 | char *dts = cplus_demangle_print (0, pdc, 16, &dsz); | |
1680 | if (!nts != !dts) | |
1681 | return true; | |
1682 | bool mismatch = strcmp (nts, dts); | |
1683 | free (nts); | |
1684 | free (dts); | |
1685 | return mismatch; | |
1686 | } | |
1687 | ||
1688 | case DEMANGLE_COMPONENT_SUB_STD: | |
1689 | if (newc.u.s_string.len != delc.u.s_string.len) | |
1690 | return true; | |
1691 | return memcmp (newc.u.s_string.string, delc.u.s_string.string, | |
1692 | newc.u.s_string.len); | |
1693 | ||
1694 | case DEMANGLE_COMPONENT_FUNCTION_PARAM: | |
1695 | case DEMANGLE_COMPONENT_TEMPLATE_PARAM: | |
1696 | return newc.u.s_number.number != delc.u.s_number.number; | |
1697 | ||
1698 | case DEMANGLE_COMPONENT_CHARACTER: | |
1699 | return newc.u.s_character.character != delc.u.s_character.character; | |
1700 | ||
1701 | case DEMANGLE_COMPONENT_DEFAULT_ARG: | |
1702 | case DEMANGLE_COMPONENT_LAMBDA: | |
1703 | if (newc.u.s_unary_num.num != delc.u.s_unary_num.num) | |
1704 | return true; | |
1705 | return new_delete_mismatch_p (*newc.u.s_unary_num.sub, | |
1706 | *delc.u.s_unary_num.sub); | |
1707 | default: | |
1708 | break; | |
1709 | } | |
1710 | ||
1711 | if (!newc.u.s_binary.left != !delc.u.s_binary.left) | |
1712 | return true; | |
1713 | ||
1714 | if (!newc.u.s_binary.left) | |
1715 | return false; | |
1716 | ||
1717 | if (new_delete_mismatch_p (*newc.u.s_binary.left, *delc.u.s_binary.left) | |
1718 | || !newc.u.s_binary.right != !delc.u.s_binary.right) | |
1719 | return true; | |
1720 | ||
1721 | if (newc.u.s_binary.right) | |
1722 | return new_delete_mismatch_p (*newc.u.s_binary.right, | |
1723 | *delc.u.s_binary.right); | |
1724 | return false; | |
1725 | } | |
1726 | ||
1727 | /* Return true if DELETE_DECL is an operator delete that's not suitable | |
4a1c20df | 1728 | to call with a pointer returned from NEW_DECL. */ |
2a837de2 MS |
1729 | |
1730 | static bool | |
1731 | new_delete_mismatch_p (tree new_decl, tree delete_decl) | |
1732 | { | |
1733 | tree new_name = DECL_ASSEMBLER_NAME (new_decl); | |
1734 | tree delete_name = DECL_ASSEMBLER_NAME (delete_decl); | |
1735 | ||
1736 | /* valid_new_delete_pair_p() returns a conservative result (currently | |
1737 | it only handles global operators). A true result is reliable but | |
96194a07 MS |
1738 | a false result doesn't necessarily mean the operators don't match |
1739 | unless CERTAIN is set. */ | |
1740 | bool certain; | |
1741 | if (valid_new_delete_pair_p (new_name, delete_name, &certain)) | |
2a837de2 | 1742 | return false; |
96194a07 MS |
1743 | /* CERTAIN is set when the negative result is certain. */ |
1744 | if (certain) | |
1745 | return true; | |
2a837de2 MS |
1746 | |
1747 | /* For anything not handled by valid_new_delete_pair_p() such as member | |
1748 | operators compare the individual demangled components of the mangled | |
1749 | name. */ | |
1750 | const char *new_str = IDENTIFIER_POINTER (new_name); | |
1751 | const char *del_str = IDENTIFIER_POINTER (delete_name); | |
1752 | ||
1753 | void *np = NULL, *dp = NULL; | |
1754 | demangle_component *ndc = cplus_demangle_v3_components (new_str, 0, &np); | |
1755 | demangle_component *ddc = cplus_demangle_v3_components (del_str, 0, &dp); | |
1756 | bool mismatch = new_delete_mismatch_p (*ndc, *ddc); | |
1757 | free (np); | |
1758 | free (dp); | |
1759 | return mismatch; | |
1760 | } | |
1761 | ||
1762 | /* ALLOC_DECL and DEALLOC_DECL are pair of allocation and deallocation | |
1763 | functions. Return true if the latter is suitable to deallocate objects | |
1764 | allocated by calls to the former. */ | |
1765 | ||
1766 | static bool | |
1767 | matching_alloc_calls_p (tree alloc_decl, tree dealloc_decl) | |
1768 | { | |
1769 | /* Set to alloc_kind_t::builtin if ALLOC_DECL is associated with | |
1770 | a built-in deallocator. */ | |
1771 | enum class alloc_kind_t { none, builtin, user } | |
1772 | alloc_dealloc_kind = alloc_kind_t::none; | |
1773 | ||
1774 | if (DECL_IS_OPERATOR_NEW_P (alloc_decl)) | |
1775 | { | |
1776 | if (DECL_IS_OPERATOR_DELETE_P (dealloc_decl)) | |
1777 | /* Return true iff both functions are of the same array or | |
1778 | singleton form and false otherwise. */ | |
1779 | return !new_delete_mismatch_p (alloc_decl, dealloc_decl); | |
1780 | ||
1781 | /* Return false for deallocation functions that are known not | |
1782 | to match. */ | |
1783 | if (fndecl_built_in_p (dealloc_decl, BUILT_IN_FREE) | |
1784 | || fndecl_built_in_p (dealloc_decl, BUILT_IN_REALLOC)) | |
1785 | return false; | |
1786 | /* Otherwise proceed below to check the deallocation function's | |
1787 | "*dealloc" attributes to look for one that mentions this operator | |
1788 | new. */ | |
1789 | } | |
1790 | else if (fndecl_built_in_p (alloc_decl, BUILT_IN_NORMAL)) | |
1791 | { | |
1792 | switch (DECL_FUNCTION_CODE (alloc_decl)) | |
1793 | { | |
1794 | case BUILT_IN_ALLOCA: | |
1795 | case BUILT_IN_ALLOCA_WITH_ALIGN: | |
1796 | return false; | |
1797 | ||
1798 | case BUILT_IN_ALIGNED_ALLOC: | |
1799 | case BUILT_IN_CALLOC: | |
1800 | case BUILT_IN_GOMP_ALLOC: | |
1801 | case BUILT_IN_MALLOC: | |
1802 | case BUILT_IN_REALLOC: | |
1803 | case BUILT_IN_STRDUP: | |
1804 | case BUILT_IN_STRNDUP: | |
1805 | if (DECL_IS_OPERATOR_DELETE_P (dealloc_decl)) | |
1806 | return false; | |
1807 | ||
1808 | if (fndecl_built_in_p (dealloc_decl, BUILT_IN_FREE) | |
1809 | || fndecl_built_in_p (dealloc_decl, BUILT_IN_REALLOC)) | |
1810 | return true; | |
1811 | ||
1812 | alloc_dealloc_kind = alloc_kind_t::builtin; | |
1813 | break; | |
1814 | ||
1815 | default: | |
1816 | break; | |
1817 | } | |
1818 | } | |
1819 | ||
1820 | /* Set if DEALLOC_DECL both allocates and deallocates. */ | |
1821 | alloc_kind_t realloc_kind = alloc_kind_t::none; | |
1822 | ||
1823 | if (fndecl_built_in_p (dealloc_decl, BUILT_IN_NORMAL)) | |
1824 | { | |
1825 | built_in_function dealloc_code = DECL_FUNCTION_CODE (dealloc_decl); | |
1826 | if (dealloc_code == BUILT_IN_REALLOC) | |
1827 | realloc_kind = alloc_kind_t::builtin; | |
1828 | ||
1829 | for (tree amats = DECL_ATTRIBUTES (alloc_decl); | |
1830 | (amats = lookup_attribute ("malloc", amats)); | |
1831 | amats = TREE_CHAIN (amats)) | |
1832 | { | |
1833 | tree args = TREE_VALUE (amats); | |
1834 | if (!args) | |
1835 | continue; | |
1836 | ||
1837 | tree fndecl = TREE_VALUE (args); | |
1838 | if (!fndecl || !DECL_P (fndecl)) | |
1839 | continue; | |
1840 | ||
1841 | if (fndecl_built_in_p (fndecl, BUILT_IN_NORMAL) | |
1842 | && dealloc_code == DECL_FUNCTION_CODE (fndecl)) | |
1843 | return true; | |
1844 | } | |
1845 | } | |
1846 | ||
1847 | const bool alloc_builtin = fndecl_built_in_p (alloc_decl, BUILT_IN_NORMAL); | |
1848 | alloc_kind_t realloc_dealloc_kind = alloc_kind_t::none; | |
1849 | ||
1850 | /* If DEALLOC_DECL has an internal "*dealloc" attribute scan the list | |
1851 | of its associated allocation functions for ALLOC_DECL. | |
1852 | If the corresponding ALLOC_DECL is found they're a matching pair, | |
1853 | otherwise they're not. | |
1854 | With DDATS set to the Deallocator's *Dealloc ATtributes... */ | |
1855 | for (tree ddats = DECL_ATTRIBUTES (dealloc_decl); | |
1856 | (ddats = lookup_attribute ("*dealloc", ddats)); | |
1857 | ddats = TREE_CHAIN (ddats)) | |
1858 | { | |
1859 | tree args = TREE_VALUE (ddats); | |
1860 | if (!args) | |
1861 | continue; | |
1862 | ||
1863 | tree alloc = TREE_VALUE (args); | |
1864 | if (!alloc) | |
1865 | continue; | |
1866 | ||
1867 | if (alloc == DECL_NAME (dealloc_decl)) | |
1868 | realloc_kind = alloc_kind_t::user; | |
1869 | ||
1870 | if (DECL_P (alloc)) | |
1871 | { | |
1872 | gcc_checking_assert (fndecl_built_in_p (alloc, BUILT_IN_NORMAL)); | |
1873 | ||
1874 | switch (DECL_FUNCTION_CODE (alloc)) | |
1875 | { | |
1876 | case BUILT_IN_ALIGNED_ALLOC: | |
1877 | case BUILT_IN_CALLOC: | |
1878 | case BUILT_IN_GOMP_ALLOC: | |
1879 | case BUILT_IN_MALLOC: | |
1880 | case BUILT_IN_REALLOC: | |
1881 | case BUILT_IN_STRDUP: | |
1882 | case BUILT_IN_STRNDUP: | |
1883 | realloc_dealloc_kind = alloc_kind_t::builtin; | |
1884 | break; | |
1885 | default: | |
1886 | break; | |
1887 | } | |
1888 | ||
1889 | if (!alloc_builtin) | |
1890 | continue; | |
1891 | ||
1892 | if (DECL_FUNCTION_CODE (alloc) != DECL_FUNCTION_CODE (alloc_decl)) | |
1893 | continue; | |
1894 | ||
1895 | return true; | |
1896 | } | |
1897 | ||
1898 | if (alloc == DECL_NAME (alloc_decl)) | |
1899 | return true; | |
1900 | } | |
1901 | ||
1902 | if (realloc_kind == alloc_kind_t::none) | |
1903 | return false; | |
1904 | ||
1905 | hash_set<tree> common_deallocs; | |
1906 | /* Special handling for deallocators. Iterate over both the allocator's | |
1907 | and the reallocator's associated deallocator functions looking for | |
1908 | the first one in common. If one is found, the de/reallocator is | |
1909 | a match for the allocator even though the latter isn't directly | |
1910 | associated with the former. This simplifies declarations in system | |
1911 | headers. | |
1912 | With AMATS set to the Allocator's Malloc ATtributes, | |
1913 | and RMATS set to Reallocator's Malloc ATtributes... */ | |
1914 | for (tree amats = DECL_ATTRIBUTES (alloc_decl), | |
1915 | rmats = DECL_ATTRIBUTES (dealloc_decl); | |
1916 | (amats = lookup_attribute ("malloc", amats)) | |
1917 | || (rmats = lookup_attribute ("malloc", rmats)); | |
1918 | amats = amats ? TREE_CHAIN (amats) : NULL_TREE, | |
1919 | rmats = rmats ? TREE_CHAIN (rmats) : NULL_TREE) | |
1920 | { | |
1921 | if (tree args = amats ? TREE_VALUE (amats) : NULL_TREE) | |
1922 | if (tree adealloc = TREE_VALUE (args)) | |
1923 | { | |
1924 | if (DECL_P (adealloc) | |
1925 | && fndecl_built_in_p (adealloc, BUILT_IN_NORMAL)) | |
1926 | { | |
1927 | built_in_function fncode = DECL_FUNCTION_CODE (adealloc); | |
1928 | if (fncode == BUILT_IN_FREE || fncode == BUILT_IN_REALLOC) | |
1929 | { | |
1930 | if (realloc_kind == alloc_kind_t::builtin) | |
1931 | return true; | |
1932 | alloc_dealloc_kind = alloc_kind_t::builtin; | |
1933 | } | |
1934 | continue; | |
1935 | } | |
1936 | ||
1937 | common_deallocs.add (adealloc); | |
1938 | } | |
1939 | ||
1940 | if (tree args = rmats ? TREE_VALUE (rmats) : NULL_TREE) | |
1941 | if (tree ddealloc = TREE_VALUE (args)) | |
1942 | { | |
1943 | if (DECL_P (ddealloc) | |
1944 | && fndecl_built_in_p (ddealloc, BUILT_IN_NORMAL)) | |
1945 | { | |
1946 | built_in_function fncode = DECL_FUNCTION_CODE (ddealloc); | |
1947 | if (fncode == BUILT_IN_FREE || fncode == BUILT_IN_REALLOC) | |
1948 | { | |
1949 | if (alloc_dealloc_kind == alloc_kind_t::builtin) | |
1950 | return true; | |
1951 | realloc_dealloc_kind = alloc_kind_t::builtin; | |
1952 | } | |
1953 | continue; | |
1954 | } | |
1955 | ||
1956 | if (common_deallocs.add (ddealloc)) | |
1957 | return true; | |
1958 | } | |
1959 | } | |
1960 | ||
1961 | /* Succeed only if ALLOC_DECL and the reallocator DEALLOC_DECL share | |
1962 | a built-in deallocator. */ | |
1963 | return (alloc_dealloc_kind == alloc_kind_t::builtin | |
1964 | && realloc_dealloc_kind == alloc_kind_t::builtin); | |
1965 | } | |
1966 | ||
1967 | /* Return true if DEALLOC_DECL is a function suitable to deallocate | |
4a1c20df | 1968 | objects allocated by the ALLOC call. */ |
2a837de2 MS |
1969 | |
1970 | static bool | |
1971 | matching_alloc_calls_p (gimple *alloc, tree dealloc_decl) | |
1972 | { | |
1973 | tree alloc_decl = gimple_call_fndecl (alloc); | |
1974 | if (!alloc_decl) | |
1975 | return true; | |
1976 | ||
1977 | return matching_alloc_calls_p (alloc_decl, dealloc_decl); | |
1978 | } | |
1979 | ||
1980 | /* Diagnose a call EXP to deallocate a pointer referenced by AREF if it | |
1981 | includes a nonzero offset. Such a pointer cannot refer to the beginning | |
1982 | of an allocated object. A negative offset may refer to it only if | |
1983 | the target pointer is unknown. */ | |
1984 | ||
1985 | static bool | |
1986 | warn_dealloc_offset (location_t loc, gimple *call, const access_ref &aref) | |
1987 | { | |
1988 | if (aref.deref || aref.offrng[0] <= 0 || aref.offrng[1] <= 0) | |
1989 | return false; | |
1990 | ||
1991 | tree dealloc_decl = gimple_call_fndecl (call); | |
1992 | if (!dealloc_decl) | |
1993 | return false; | |
1994 | ||
1995 | if (DECL_IS_OPERATOR_DELETE_P (dealloc_decl) | |
1996 | && !DECL_IS_REPLACEABLE_OPERATOR (dealloc_decl)) | |
1997 | { | |
1998 | /* A call to a user-defined operator delete with a pointer plus offset | |
1999 | may be valid if it's returned from an unknown function (i.e., one | |
2000 | that's not operator new). */ | |
2001 | if (TREE_CODE (aref.ref) == SSA_NAME) | |
2002 | { | |
2003 | gimple *def_stmt = SSA_NAME_DEF_STMT (aref.ref); | |
2004 | if (is_gimple_call (def_stmt)) | |
2005 | { | |
2006 | tree alloc_decl = gimple_call_fndecl (def_stmt); | |
2007 | if (!alloc_decl || !DECL_IS_OPERATOR_NEW_P (alloc_decl)) | |
2008 | return false; | |
2009 | } | |
2010 | } | |
2011 | } | |
2012 | ||
2013 | char offstr[80]; | |
2014 | offstr[0] = '\0'; | |
2015 | if (wi::fits_shwi_p (aref.offrng[0])) | |
2016 | { | |
2017 | if (aref.offrng[0] == aref.offrng[1] | |
2018 | || !wi::fits_shwi_p (aref.offrng[1])) | |
2019 | sprintf (offstr, " %lli", | |
2020 | (long long)aref.offrng[0].to_shwi ()); | |
2021 | else | |
2022 | sprintf (offstr, " [%lli, %lli]", | |
2023 | (long long)aref.offrng[0].to_shwi (), | |
2024 | (long long)aref.offrng[1].to_shwi ()); | |
2025 | } | |
2026 | ||
6ab98d8b | 2027 | auto_diagnostic_group d; |
2a837de2 MS |
2028 | if (!warning_at (loc, OPT_Wfree_nonheap_object, |
2029 | "%qD called on pointer %qE with nonzero offset%s", | |
2030 | dealloc_decl, aref.ref, offstr)) | |
2031 | return false; | |
2032 | ||
2033 | if (DECL_P (aref.ref)) | |
81d6cdd3 | 2034 | inform (get_location (aref.ref), "declared here"); |
2a837de2 MS |
2035 | else if (TREE_CODE (aref.ref) == SSA_NAME) |
2036 | { | |
2037 | gimple *def_stmt = SSA_NAME_DEF_STMT (aref.ref); | |
2038 | if (is_gimple_call (def_stmt)) | |
2039 | { | |
81d6cdd3 | 2040 | location_t def_loc = get_location (def_stmt); |
2a837de2 MS |
2041 | tree alloc_decl = gimple_call_fndecl (def_stmt); |
2042 | if (alloc_decl) | |
2043 | inform (def_loc, | |
2044 | "returned from %qD", alloc_decl); | |
2045 | else if (tree alloc_fntype = gimple_call_fntype (def_stmt)) | |
2046 | inform (def_loc, | |
2047 | "returned from %qT", alloc_fntype); | |
2048 | else | |
2049 | inform (def_loc, "obtained here"); | |
2050 | } | |
2051 | } | |
2052 | ||
2053 | return true; | |
2054 | } | |
2055 | ||
2a837de2 MS |
2056 | namespace { |
2057 | ||
2058 | const pass_data pass_data_waccess = { | |
2059 | GIMPLE_PASS, | |
2060 | "waccess", | |
2061 | OPTGROUP_NONE, | |
58ec0964 | 2062 | TV_WARN_ACCESS, /* timer variable */ |
2a837de2 MS |
2063 | PROP_cfg, /* properties_required */ |
2064 | 0, /* properties_provided */ | |
2065 | 0, /* properties_destroyed */ | |
2066 | 0, /* properties_start */ | |
2067 | 0, /* properties_finish */ | |
2068 | }; | |
2069 | ||
2070 | /* Pass to detect invalid accesses. */ | |
2071 | class pass_waccess : public gimple_opt_pass | |
2072 | { | |
2073 | public: | |
b48d4e68 MS |
2074 | pass_waccess (gcc::context *); |
2075 | ||
2076 | ~pass_waccess (); | |
2a837de2 | 2077 | |
725793af | 2078 | opt_pass *clone () final override; |
2a837de2 | 2079 | |
725793af | 2080 | bool gate (function *) final override; |
671a2836 | 2081 | |
725793af | 2082 | void set_pass_param (unsigned, bool) final override; |
9d6a0f38 | 2083 | |
725793af | 2084 | unsigned int execute (function *) final override; |
2a837de2 | 2085 | |
ece28da9 MS |
2086 | private: |
2087 | /* Not copyable or assignable. */ | |
2088 | pass_waccess (pass_waccess &) = delete; | |
2089 | void operator= (pass_waccess &) = delete; | |
2090 | ||
88b504b7 MS |
2091 | /* Check a call to an atomic built-in function. */ |
2092 | bool check_atomic_builtin (gcall *); | |
2093 | ||
81d6cdd3 MS |
2094 | /* Check a call to a built-in function. */ |
2095 | bool check_builtin (gcall *); | |
2096 | ||
671a2836 MS |
2097 | /* Check a call to an ordinary function for invalid accesses. */ |
2098 | bool check_call_access (gcall *); | |
b48d4e68 | 2099 | |
9d6a0f38 MS |
2100 | /* Check a non-call statement. */ |
2101 | void check_stmt (gimple *); | |
2102 | ||
81d6cdd3 | 2103 | /* Check statements in a basic block. */ |
671a2836 | 2104 | void check_block (basic_block); |
81d6cdd3 MS |
2105 | |
2106 | /* Check a call to a function. */ | |
671a2836 | 2107 | void check_call (gcall *); |
2a837de2 | 2108 | |
ece28da9 MS |
2109 | /* Check a call to the named built-in function. */ |
2110 | void check_alloca (gcall *); | |
2111 | void check_alloc_size_call (gcall *); | |
2112 | void check_strcat (gcall *); | |
2113 | void check_strncat (gcall *); | |
2114 | void check_stxcpy (gcall *); | |
2115 | void check_stxncpy (gcall *); | |
2116 | void check_strncmp (gcall *); | |
2117 | void check_memop_access (gimple *, tree, tree, tree); | |
9a27acc3 | 2118 | void check_read_access (gimple *, tree, tree = NULL_TREE, int = 1); |
ece28da9 MS |
2119 | |
2120 | void maybe_check_dealloc_call (gcall *); | |
2121 | void maybe_check_access_sizes (rdwr_map *, tree, tree, gimple *); | |
5a431b60 MS |
2122 | bool maybe_warn_memmodel (gimple *, tree, tree, const unsigned char *); |
2123 | void check_atomic_memmodel (gimple *, tree, tree, const unsigned char *); | |
b48d4e68 | 2124 | |
671a2836 | 2125 | /* Check for uses of indeterminate pointers. */ |
9d6a0f38 | 2126 | void check_pointer_uses (gimple *, tree, tree = NULL_TREE, bool = false); |
671a2836 MS |
2127 | |
2128 | /* Return the argument that a call returns. */ | |
2129 | tree gimple_call_return_arg (gcall *); | |
9d6a0f38 MS |
2130 | |
2131 | /* Check a call for uses of a dangling pointer arguments. */ | |
2132 | void check_call_dangling (gcall *); | |
2133 | ||
2134 | /* Check uses of a dangling pointer or those derived from it. */ | |
2135 | void check_dangling_uses (tree, tree, bool = false, bool = false); | |
2136 | void check_dangling_uses (); | |
2137 | void check_dangling_stores (); | |
2138 | void check_dangling_stores (basic_block, hash_set<tree> &, auto_bitmap &); | |
671a2836 | 2139 | |
9d6a0f38 | 2140 | void warn_invalid_pointer (tree, gimple *, gimple *, tree, bool, bool = false); |
671a2836 MS |
2141 | |
2142 | /* Return true if use follows an invalidating statement. */ | |
9d6a0f38 | 2143 | bool use_after_inval_p (gimple *, gimple *, bool = false); |
671a2836 | 2144 | |
68e9b7b6 MS |
2145 | /* A pointer_query object to store information about pointers and |
2146 | their targets in. */ | |
ece28da9 | 2147 | pointer_query m_ptr_qry; |
9d6a0f38 MS |
2148 | /* Mapping from DECLs and their clobber statements in the function. */ |
2149 | hash_map<tree, gimple *> m_clobbers; | |
671a2836 MS |
2150 | /* A bit is set for each basic block whose statements have been assigned |
2151 | valid UIDs. */ | |
2152 | bitmap m_bb_uids_set; | |
2153 | /* The current function. */ | |
2154 | function *m_func; | |
9d6a0f38 MS |
2155 | /* True to run checks for uses of dangling pointers. */ |
2156 | bool m_check_dangling_p; | |
2157 | /* True to run checks early on in the optimization pipeline. */ | |
2158 | bool m_early_checks_p; | |
2a837de2 MS |
2159 | }; |
2160 | ||
b48d4e68 MS |
2161 | /* Construct the pass. */ |
2162 | ||
2163 | pass_waccess::pass_waccess (gcc::context *ctxt) | |
2164 | : gimple_opt_pass (pass_data_waccess, ctxt), | |
68e9b7b6 | 2165 | m_ptr_qry (NULL), |
9d6a0f38 | 2166 | m_clobbers (), |
671a2836 | 2167 | m_bb_uids_set (), |
9d6a0f38 MS |
2168 | m_func (), |
2169 | m_check_dangling_p (), | |
2170 | m_early_checks_p () | |
b48d4e68 MS |
2171 | { |
2172 | } | |
2173 | ||
9d6a0f38 MS |
2174 | /* Return a copy of the pass with RUN_NUMBER one greater than THIS. */ |
2175 | ||
2176 | opt_pass* | |
2177 | pass_waccess::clone () | |
2178 | { | |
2179 | return new pass_waccess (m_ctxt); | |
2180 | } | |
2181 | ||
b48d4e68 MS |
2182 | /* Release pointer_query cache. */ |
2183 | ||
2184 | pass_waccess::~pass_waccess () | |
2185 | { | |
ece28da9 | 2186 | m_ptr_qry.flush_cache (); |
b48d4e68 MS |
2187 | } |
2188 | ||
9d6a0f38 MS |
2189 | void |
2190 | pass_waccess::set_pass_param (unsigned int n, bool early) | |
2191 | { | |
2192 | gcc_assert (n == 0); | |
2193 | ||
2194 | m_early_checks_p = early; | |
2195 | } | |
2196 | ||
2a837de2 MS |
2197 | /* Return true when any checks performed by the pass are enabled. */ |
2198 | ||
2199 | bool | |
2200 | pass_waccess::gate (function *) | |
2201 | { | |
2202 | return (warn_free_nonheap_object | |
2203 | || warn_mismatched_alloc | |
2204 | || warn_mismatched_new_delete); | |
2205 | } | |
2206 | ||
b48d4e68 MS |
2207 | /* Initialize ALLOC_OBJECT_SIZE_LIMIT based on the -Walloc-size-larger-than= |
2208 | setting if the option is specified, or to the maximum object size if it | |
2209 | is not. Return the initialized value. */ | |
2210 | ||
2211 | static tree | |
2212 | alloc_max_size (void) | |
2213 | { | |
2214 | HOST_WIDE_INT limit = warn_alloc_size_limit; | |
2215 | if (limit == HOST_WIDE_INT_MAX) | |
2216 | limit = tree_to_shwi (TYPE_MAX_VALUE (ptrdiff_type_node)); | |
2217 | ||
2218 | return build_int_cst (size_type_node, limit); | |
2219 | } | |
2220 | ||
2221 | /* Diagnose a call EXP to function FN decorated with attribute alloc_size | |
2222 | whose argument numbers given by IDX with values given by ARGS exceed | |
4a1c20df | 2223 | the maximum object size or cause an unsigned overflow (wrapping) when |
b48d4e68 MS |
2224 | multiplied. FN is null when EXP is a call via a function pointer. |
2225 | When ARGS[0] is null the function does nothing. ARGS[1] may be null | |
2226 | for functions like malloc, and non-null for those like calloc that | |
2227 | are decorated with a two-argument attribute alloc_size. */ | |
2228 | ||
2229 | void | |
2230 | maybe_warn_alloc_args_overflow (gimple *stmt, const tree args[2], | |
2231 | const int idx[2]) | |
2232 | { | |
2233 | /* The range each of the (up to) two arguments is known to be in. */ | |
2234 | tree argrange[2][2] = { { NULL_TREE, NULL_TREE }, { NULL_TREE, NULL_TREE } }; | |
2235 | ||
2236 | /* Maximum object size set by -Walloc-size-larger-than= or SIZE_MAX / 2. */ | |
2237 | tree maxobjsize = alloc_max_size (); | |
2238 | ||
2239 | location_t loc = get_location (stmt); | |
2240 | ||
2241 | tree fn = gimple_call_fndecl (stmt); | |
2242 | tree fntype = fn ? TREE_TYPE (fn) : gimple_call_fntype (stmt); | |
2243 | bool warned = false; | |
2244 | ||
2245 | /* Validate each argument individually. */ | |
2246 | for (unsigned i = 0; i != 2 && args[i]; ++i) | |
2247 | { | |
2248 | if (TREE_CODE (args[i]) == INTEGER_CST) | |
2249 | { | |
2250 | argrange[i][0] = args[i]; | |
2251 | argrange[i][1] = args[i]; | |
2252 | ||
2253 | if (tree_int_cst_lt (args[i], integer_zero_node)) | |
2254 | { | |
2255 | warned = warning_at (loc, OPT_Walloc_size_larger_than_, | |
2256 | "argument %i value %qE is negative", | |
2257 | idx[i] + 1, args[i]); | |
2258 | } | |
2259 | else if (integer_zerop (args[i])) | |
2260 | { | |
2261 | /* Avoid issuing -Walloc-zero for allocation functions other | |
2262 | than __builtin_alloca that are declared with attribute | |
2263 | returns_nonnull because there's no portability risk. This | |
2264 | avoids warning for such calls to libiberty's xmalloc and | |
2265 | friends. | |
2266 | Also avoid issuing the warning for calls to function named | |
2267 | "alloca". */ | |
2268 | if (fn && fndecl_built_in_p (fn, BUILT_IN_ALLOCA) | |
2269 | ? IDENTIFIER_LENGTH (DECL_NAME (fn)) != 6 | |
2270 | : !lookup_attribute ("returns_nonnull", | |
2271 | TYPE_ATTRIBUTES (fntype))) | |
2272 | warned = warning_at (loc, OPT_Walloc_zero, | |
2273 | "argument %i value is zero", | |
2274 | idx[i] + 1); | |
2275 | } | |
2276 | else if (tree_int_cst_lt (maxobjsize, args[i])) | |
2277 | { | |
2278 | /* G++ emits calls to ::operator new[](SIZE_MAX) in C++98 | |
2279 | mode and with -fno-exceptions as a way to indicate array | |
2280 | size overflow. There's no good way to detect C++98 here | |
2281 | so avoid diagnosing these calls for all C++ modes. */ | |
2282 | if (i == 0 | |
2283 | && fn | |
2284 | && !args[1] | |
2285 | && lang_GNU_CXX () | |
2286 | && DECL_IS_OPERATOR_NEW_P (fn) | |
2287 | && integer_all_onesp (args[i])) | |
2288 | continue; | |
2289 | ||
2290 | warned = warning_at (loc, OPT_Walloc_size_larger_than_, | |
2291 | "argument %i value %qE exceeds " | |
2292 | "maximum object size %E", | |
2293 | idx[i] + 1, args[i], maxobjsize); | |
2294 | } | |
2295 | } | |
2296 | else if (TREE_CODE (args[i]) == SSA_NAME | |
2297 | && get_size_range (args[i], argrange[i])) | |
2298 | { | |
2299 | /* Verify that the argument's range is not negative (including | |
2300 | upper bound of zero). */ | |
2301 | if (tree_int_cst_lt (argrange[i][0], integer_zero_node) | |
2302 | && tree_int_cst_le (argrange[i][1], integer_zero_node)) | |
2303 | { | |
2304 | warned = warning_at (loc, OPT_Walloc_size_larger_than_, | |
2305 | "argument %i range [%E, %E] is negative", | |
2306 | idx[i] + 1, | |
2307 | argrange[i][0], argrange[i][1]); | |
2308 | } | |
2309 | else if (tree_int_cst_lt (maxobjsize, argrange[i][0])) | |
2310 | { | |
2311 | warned = warning_at (loc, OPT_Walloc_size_larger_than_, | |
2312 | "argument %i range [%E, %E] exceeds " | |
2313 | "maximum object size %E", | |
2314 | idx[i] + 1, | |
2315 | argrange[i][0], argrange[i][1], | |
2316 | maxobjsize); | |
2317 | } | |
2318 | } | |
2319 | } | |
2320 | ||
b3aa3288 | 2321 | if (!argrange[0][0]) |
b48d4e68 MS |
2322 | return; |
2323 | ||
2324 | /* For a two-argument alloc_size, validate the product of the two | |
2325 | arguments if both of their values or ranges are known. */ | |
2326 | if (!warned && tree_fits_uhwi_p (argrange[0][0]) | |
2327 | && argrange[1][0] && tree_fits_uhwi_p (argrange[1][0]) | |
2328 | && !integer_onep (argrange[0][0]) | |
2329 | && !integer_onep (argrange[1][0])) | |
2330 | { | |
2331 | /* Check for overflow in the product of a function decorated with | |
2332 | attribute alloc_size (X, Y). */ | |
2333 | unsigned szprec = TYPE_PRECISION (size_type_node); | |
2334 | wide_int x = wi::to_wide (argrange[0][0], szprec); | |
2335 | wide_int y = wi::to_wide (argrange[1][0], szprec); | |
2336 | ||
2337 | wi::overflow_type vflow; | |
2338 | wide_int prod = wi::umul (x, y, &vflow); | |
2339 | ||
2340 | if (vflow) | |
2341 | warned = warning_at (loc, OPT_Walloc_size_larger_than_, | |
2342 | "product %<%E * %E%> of arguments %i and %i " | |
2343 | "exceeds %<SIZE_MAX%>", | |
2344 | argrange[0][0], argrange[1][0], | |
2345 | idx[0] + 1, idx[1] + 1); | |
2346 | else if (wi::ltu_p (wi::to_wide (maxobjsize, szprec), prod)) | |
2347 | warned = warning_at (loc, OPT_Walloc_size_larger_than_, | |
2348 | "product %<%E * %E%> of arguments %i and %i " | |
2349 | "exceeds maximum object size %E", | |
2350 | argrange[0][0], argrange[1][0], | |
2351 | idx[0] + 1, idx[1] + 1, | |
2352 | maxobjsize); | |
2353 | ||
2354 | if (warned) | |
2355 | { | |
2356 | /* Print the full range of each of the two arguments to make | |
2357 | it clear when it is, in fact, in a range and not constant. */ | |
2358 | if (argrange[0][0] != argrange [0][1]) | |
2359 | inform (loc, "argument %i in the range [%E, %E]", | |
2360 | idx[0] + 1, argrange[0][0], argrange[0][1]); | |
2361 | if (argrange[1][0] != argrange [1][1]) | |
2362 | inform (loc, "argument %i in the range [%E, %E]", | |
2363 | idx[1] + 1, argrange[1][0], argrange[1][1]); | |
2364 | } | |
2365 | } | |
2366 | ||
2367 | if (warned && fn) | |
2368 | { | |
2369 | location_t fnloc = DECL_SOURCE_LOCATION (fn); | |
2370 | ||
2371 | if (DECL_IS_UNDECLARED_BUILTIN (fn)) | |
2372 | inform (loc, | |
2373 | "in a call to built-in allocation function %qD", fn); | |
2374 | else | |
2375 | inform (fnloc, | |
2376 | "in a call to allocation function %qD declared here", fn); | |
2377 | } | |
2378 | } | |
2379 | ||
2380 | /* Check a call to an alloca function for an excessive size. */ | |
2381 | ||
ece28da9 MS |
2382 | void |
2383 | pass_waccess::check_alloca (gcall *stmt) | |
b48d4e68 | 2384 | { |
9d6a0f38 MS |
2385 | if (m_early_checks_p) |
2386 | return; | |
2387 | ||
b48d4e68 MS |
2388 | if ((warn_vla_limit >= HOST_WIDE_INT_MAX |
2389 | && warn_alloc_size_limit < warn_vla_limit) | |
2390 | || (warn_alloca_limit >= HOST_WIDE_INT_MAX | |
2391 | && warn_alloc_size_limit < warn_alloca_limit)) | |
2392 | { | |
2393 | /* -Walloca-larger-than and -Wvla-larger-than settings of less | |
2394 | than HWI_MAX override the more general -Walloc-size-larger-than | |
2395 | so unless either of the former options is smaller than the last | |
4a1c20df | 2396 | one (which would imply that the call was already checked), check |
b48d4e68 MS |
2397 | the alloca arguments for overflow. */ |
2398 | const tree alloc_args[] = { call_arg (stmt, 0), NULL_TREE }; | |
2399 | const int idx[] = { 0, -1 }; | |
2400 | maybe_warn_alloc_args_overflow (stmt, alloc_args, idx); | |
2401 | } | |
2402 | } | |
2403 | ||
2404 | /* Check a call to an allocation function for an excessive size. */ | |
2405 | ||
ece28da9 MS |
2406 | void |
2407 | pass_waccess::check_alloc_size_call (gcall *stmt) | |
b48d4e68 | 2408 | { |
9d6a0f38 MS |
2409 | if (m_early_checks_p) |
2410 | return; | |
2411 | ||
2412 | if (gimple_call_num_args (stmt) < 1) | |
2413 | /* Avoid invalid calls to functions without a prototype. */ | |
2414 | return; | |
2415 | ||
b48d4e68 MS |
2416 | tree fndecl = gimple_call_fndecl (stmt); |
2417 | if (fndecl && gimple_call_builtin_p (stmt, BUILT_IN_NORMAL)) | |
2418 | { | |
2419 | /* Alloca is handled separately. */ | |
2420 | switch (DECL_FUNCTION_CODE (fndecl)) | |
2421 | { | |
2422 | case BUILT_IN_ALLOCA: | |
2423 | case BUILT_IN_ALLOCA_WITH_ALIGN: | |
2424 | case BUILT_IN_ALLOCA_WITH_ALIGN_AND_MAX: | |
2425 | return; | |
2426 | default: | |
2427 | break; | |
2428 | } | |
2429 | } | |
2430 | ||
2431 | tree fntype = gimple_call_fntype (stmt); | |
2432 | tree fntypeattrs = TYPE_ATTRIBUTES (fntype); | |
2433 | ||
2434 | tree alloc_size = lookup_attribute ("alloc_size", fntypeattrs); | |
2435 | if (!alloc_size) | |
2436 | return; | |
2437 | ||
2438 | /* Extract attribute alloc_size from the type of the called expression | |
2439 | (which could be a function or a function pointer) and if set, store | |
2440 | the indices of the corresponding arguments in ALLOC_IDX, and then | |
2441 | the actual argument(s) at those indices in ALLOC_ARGS. */ | |
2442 | int idx[2] = { -1, -1 }; | |
2443 | tree alloc_args[] = { NULL_TREE, NULL_TREE }; | |
eacdfaf7 | 2444 | unsigned nargs = gimple_call_num_args (stmt); |
b48d4e68 MS |
2445 | |
2446 | tree args = TREE_VALUE (alloc_size); | |
2447 | idx[0] = TREE_INT_CST_LOW (TREE_VALUE (args)) - 1; | |
eacdfaf7 JJ |
2448 | /* Avoid invalid calls to functions without a prototype. */ |
2449 | if ((unsigned) idx[0] >= nargs) | |
2450 | return; | |
b48d4e68 MS |
2451 | alloc_args[0] = call_arg (stmt, idx[0]); |
2452 | if (TREE_CHAIN (args)) | |
2453 | { | |
2454 | idx[1] = TREE_INT_CST_LOW (TREE_VALUE (TREE_CHAIN (args))) - 1; | |
eacdfaf7 JJ |
2455 | if ((unsigned) idx[1] >= nargs) |
2456 | return; | |
b48d4e68 MS |
2457 | alloc_args[1] = call_arg (stmt, idx[1]); |
2458 | } | |
2459 | ||
2460 | maybe_warn_alloc_args_overflow (stmt, alloc_args, idx); | |
2461 | } | |
2462 | ||
81d6cdd3 MS |
2463 | /* Check a call STMT to strcat() for overflow and warn if it does. */ |
2464 | ||
ece28da9 MS |
2465 | void |
2466 | pass_waccess::check_strcat (gcall *stmt) | |
81d6cdd3 | 2467 | { |
9d6a0f38 MS |
2468 | if (m_early_checks_p) |
2469 | return; | |
2470 | ||
b48d4e68 | 2471 | if (!warn_stringop_overflow && !warn_stringop_overread) |
81d6cdd3 MS |
2472 | return; |
2473 | ||
2474 | tree dest = call_arg (stmt, 0); | |
2475 | tree src = call_arg (stmt, 1); | |
2476 | ||
2477 | /* There is no way here to determine the length of the string in | |
2478 | the destination to which the SRC string is being appended so | |
4a1c20df | 2479 | just diagnose cases when the source string is longer than |
81d6cdd3 | 2480 | the destination object. */ |
9a27acc3 MS |
2481 | access_data data (m_ptr_qry.rvals, stmt, access_read_write, NULL_TREE, |
2482 | true, NULL_TREE, true); | |
81d6cdd3 | 2483 | const int ost = warn_stringop_overflow ? warn_stringop_overflow - 1 : 1; |
9a27acc3 MS |
2484 | compute_objsize (src, stmt, ost, &data.src, &m_ptr_qry); |
2485 | tree destsize = compute_objsize (dest, stmt, ost, &data.dst, &m_ptr_qry); | |
81d6cdd3 MS |
2486 | |
2487 | check_access (stmt, /*dstwrite=*/NULL_TREE, /*maxread=*/NULL_TREE, | |
9a27acc3 | 2488 | src, destsize, data.mode, &data, m_ptr_qry.rvals); |
81d6cdd3 MS |
2489 | } |
2490 | ||
2491 | /* Check a call STMT to strcat() for overflow and warn if it does. */ | |
2492 | ||
ece28da9 MS |
2493 | void |
2494 | pass_waccess::check_strncat (gcall *stmt) | |
81d6cdd3 | 2495 | { |
9d6a0f38 MS |
2496 | if (m_early_checks_p) |
2497 | return; | |
2498 | ||
b48d4e68 | 2499 | if (!warn_stringop_overflow && !warn_stringop_overread) |
81d6cdd3 MS |
2500 | return; |
2501 | ||
2502 | tree dest = call_arg (stmt, 0); | |
2503 | tree src = call_arg (stmt, 1); | |
2504 | /* The upper bound on the number of bytes to write. */ | |
2505 | tree maxread = call_arg (stmt, 2); | |
2506 | ||
2507 | /* Detect unterminated source (only). */ | |
2508 | if (!check_nul_terminated_array (stmt, src, maxread)) | |
2509 | return; | |
2510 | ||
2511 | /* The length of the source sequence. */ | |
2512 | tree slen = c_strlen (src, 1); | |
2513 | ||
2514 | /* Try to determine the range of lengths that the source expression | |
2515 | refers to. Since the lengths are only used for warning and not | |
2516 | for code generation disable strict mode below. */ | |
2517 | tree maxlen = slen; | |
2518 | if (!maxlen) | |
2519 | { | |
2520 | c_strlen_data lendata = { }; | |
2521 | get_range_strlen (src, &lendata, /* eltsize = */ 1); | |
2522 | maxlen = lendata.maxbound; | |
2523 | } | |
2524 | ||
9a27acc3 | 2525 | access_data data (m_ptr_qry.rvals, stmt, access_read_write); |
81d6cdd3 MS |
2526 | /* Try to verify that the destination is big enough for the shortest |
2527 | string. First try to determine the size of the destination object | |
2528 | into which the source is being copied. */ | |
ece28da9 | 2529 | const int ost = warn_stringop_overflow - 1; |
9a27acc3 | 2530 | tree destsize = compute_objsize (dest, stmt, ost, &data.dst, &m_ptr_qry); |
81d6cdd3 MS |
2531 | |
2532 | /* Add one for the terminating nul. */ | |
2533 | tree srclen = (maxlen | |
2534 | ? fold_build2 (PLUS_EXPR, size_type_node, maxlen, | |
2535 | size_one_node) | |
2536 | : NULL_TREE); | |
2537 | ||
2538 | /* The strncat function copies at most MAXREAD bytes and always appends | |
2539 | the terminating nul so the specified upper bound should never be equal | |
2540 | to (or greater than) the size of the destination. */ | |
2541 | if (tree_fits_uhwi_p (maxread) && tree_fits_uhwi_p (destsize) | |
2542 | && tree_int_cst_equal (destsize, maxread)) | |
2543 | { | |
2544 | location_t loc = get_location (stmt); | |
2545 | warning_at (loc, OPT_Wstringop_overflow_, | |
2546 | "%qD specified bound %E equals destination size", | |
2547 | get_callee_fndecl (stmt), maxread); | |
2548 | ||
2549 | return; | |
2550 | } | |
2551 | ||
2552 | if (!srclen | |
2553 | || (maxread && tree_fits_uhwi_p (maxread) | |
2554 | && tree_fits_uhwi_p (srclen) | |
2555 | && tree_int_cst_lt (maxread, srclen))) | |
2556 | srclen = maxread; | |
2557 | ||
2558 | check_access (stmt, /*dstwrite=*/NULL_TREE, maxread, srclen, | |
9a27acc3 | 2559 | destsize, data.mode, &data, m_ptr_qry.rvals); |
81d6cdd3 MS |
2560 | } |
2561 | ||
2562 | /* Check a call STMT to stpcpy() or strcpy() for overflow and warn | |
2563 | if it does. */ | |
2564 | ||
ece28da9 MS |
2565 | void |
2566 | pass_waccess::check_stxcpy (gcall *stmt) | |
81d6cdd3 | 2567 | { |
9d6a0f38 MS |
2568 | if (m_early_checks_p) |
2569 | return; | |
2570 | ||
81d6cdd3 MS |
2571 | tree dst = call_arg (stmt, 0); |
2572 | tree src = call_arg (stmt, 1); | |
2573 | ||
2574 | tree size; | |
2575 | bool exact; | |
2576 | if (tree nonstr = unterminated_array (src, &size, &exact)) | |
2577 | { | |
2578 | /* NONSTR refers to the non-nul terminated constant array. */ | |
2579 | warn_string_no_nul (get_location (stmt), stmt, NULL, src, nonstr, | |
2580 | size, exact); | |
2581 | return; | |
2582 | } | |
2583 | ||
2584 | if (warn_stringop_overflow) | |
2585 | { | |
9a27acc3 MS |
2586 | access_data data (m_ptr_qry.rvals, stmt, access_read_write, NULL_TREE, |
2587 | true, NULL_TREE, true); | |
81d6cdd3 | 2588 | const int ost = warn_stringop_overflow ? warn_stringop_overflow - 1 : 1; |
9a27acc3 MS |
2589 | compute_objsize (src, stmt, ost, &data.src, &m_ptr_qry); |
2590 | tree dstsize = compute_objsize (dst, stmt, ost, &data.dst, &m_ptr_qry); | |
81d6cdd3 MS |
2591 | check_access (stmt, /*dstwrite=*/ NULL_TREE, |
2592 | /*maxread=*/ NULL_TREE, /*srcstr=*/ src, | |
9a27acc3 | 2593 | dstsize, data.mode, &data, m_ptr_qry.rvals); |
81d6cdd3 MS |
2594 | } |
2595 | ||
2596 | /* Check to see if the argument was declared attribute nonstring | |
2597 | and if so, issue a warning since at this point it's not known | |
2598 | to be nul-terminated. */ | |
2599 | tree fndecl = get_callee_fndecl (stmt); | |
2600 | maybe_warn_nonstring_arg (fndecl, stmt); | |
2601 | } | |
2602 | ||
2603 | /* Check a call STMT to stpncpy() or strncpy() for overflow and warn | |
2604 | if it does. */ | |
2605 | ||
ece28da9 MS |
2606 | void |
2607 | pass_waccess::check_stxncpy (gcall *stmt) | |
81d6cdd3 | 2608 | { |
9d6a0f38 | 2609 | if (m_early_checks_p || !warn_stringop_overflow) |
81d6cdd3 MS |
2610 | return; |
2611 | ||
2612 | tree dst = call_arg (stmt, 0); | |
2613 | tree src = call_arg (stmt, 1); | |
2614 | /* The number of bytes to write (not the maximum). */ | |
2615 | tree len = call_arg (stmt, 2); | |
2616 | ||
9a27acc3 MS |
2617 | access_data data (m_ptr_qry.rvals, stmt, access_read_write, len, true, len, |
2618 | true); | |
81d6cdd3 | 2619 | const int ost = warn_stringop_overflow ? warn_stringop_overflow - 1 : 1; |
9a27acc3 MS |
2620 | compute_objsize (src, stmt, ost, &data.src, &m_ptr_qry); |
2621 | tree dstsize = compute_objsize (dst, stmt, ost, &data.dst, &m_ptr_qry); | |
81d6cdd3 | 2622 | |
9a27acc3 MS |
2623 | check_access (stmt, /*dstwrite=*/len, /*maxread=*/len, src, dstsize, |
2624 | data.mode, &data, m_ptr_qry.rvals); | |
81d6cdd3 MS |
2625 | } |
2626 | ||
2627 | /* Check a call STMT to stpncpy() or strncpy() for overflow and warn | |
2628 | if it does. */ | |
2629 | ||
ece28da9 MS |
2630 | void |
2631 | pass_waccess::check_strncmp (gcall *stmt) | |
81d6cdd3 | 2632 | { |
9d6a0f38 | 2633 | if (m_early_checks_p || !warn_stringop_overread) |
81d6cdd3 MS |
2634 | return; |
2635 | ||
2636 | tree arg1 = call_arg (stmt, 0); | |
2637 | tree arg2 = call_arg (stmt, 1); | |
2638 | tree bound = call_arg (stmt, 2); | |
2639 | ||
2640 | /* First check each argument separately, considering the bound. */ | |
2641 | if (!check_nul_terminated_array (stmt, arg1, bound) | |
2642 | || !check_nul_terminated_array (stmt, arg2, bound)) | |
2643 | return; | |
2644 | ||
2645 | /* A strncmp read from each argument is constrained not just by | |
2646 | the bound but also by the length of the shorter string. Specifying | |
2647 | a bound that's larger than the size of either array makes no sense | |
2648 | and is likely a bug. When the length of neither of the two strings | |
2649 | is known but the sizes of both of the arrays they are stored in is, | |
027e3041 | 2650 | issue a warning if the bound is larger than the size of |
81d6cdd3 MS |
2651 | the larger of the two arrays. */ |
2652 | ||
2653 | c_strlen_data lendata1{ }, lendata2{ }; | |
2654 | tree len1 = c_strlen (arg1, 1, &lendata1); | |
2655 | tree len2 = c_strlen (arg2, 1, &lendata2); | |
2656 | ||
9a27acc3 MS |
2657 | if (len1 && TREE_CODE (len1) != INTEGER_CST) |
2658 | len1 = NULL_TREE; | |
2659 | if (len2 && TREE_CODE (len2) != INTEGER_CST) | |
2660 | len2 = NULL_TREE; | |
2661 | ||
81d6cdd3 MS |
2662 | if (len1 && len2) |
2663 | /* If the length of both arguments was computed they must both be | |
2664 | nul-terminated and no further checking is necessary regardless | |
2665 | of the bound. */ | |
2666 | return; | |
2667 | ||
2668 | /* Check to see if the argument was declared with attribute nonstring | |
2669 | and if so, issue a warning since at this point it's not known to be | |
2670 | nul-terminated. */ | |
2671 | if (maybe_warn_nonstring_arg (get_callee_fndecl (stmt), stmt)) | |
2672 | return; | |
2673 | ||
9a27acc3 MS |
2674 | access_data adata1 (m_ptr_qry.rvals, stmt, access_read_only, NULL_TREE, false, |
2675 | bound, true); | |
2676 | access_data adata2 (m_ptr_qry.rvals, stmt, access_read_only, NULL_TREE, false, | |
2677 | bound, true); | |
81d6cdd3 MS |
2678 | |
2679 | /* Determine the range of the bound first and bail if it fails; it's | |
2680 | cheaper than computing the size of the objects. */ | |
2681 | tree bndrng[2] = { NULL_TREE, NULL_TREE }; | |
f9379fcb | 2682 | get_size_range (m_ptr_qry.rvals, bound, stmt, bndrng, adata1.src_bndrng); |
81d6cdd3 MS |
2683 | if (!bndrng[0] || integer_zerop (bndrng[0])) |
2684 | return; | |
2685 | ||
2686 | if (len1 && tree_int_cst_lt (len1, bndrng[0])) | |
2687 | bndrng[0] = len1; | |
2688 | if (len2 && tree_int_cst_lt (len2, bndrng[0])) | |
2689 | bndrng[0] = len2; | |
2690 | ||
2691 | /* compute_objsize almost never fails (and ultimately should never | |
2692 | fail). Don't bother to handle the rare case when it does. */ | |
9a27acc3 MS |
2693 | if (!compute_objsize (arg1, stmt, 1, &adata1.src, &m_ptr_qry) |
2694 | || !compute_objsize (arg2, stmt, 1, &adata2.src, &m_ptr_qry)) | |
81d6cdd3 MS |
2695 | return; |
2696 | ||
2697 | /* Compute the size of the remaining space in each array after | |
2698 | subtracting any offset into it. */ | |
2699 | offset_int rem1 = adata1.src.size_remaining (); | |
2700 | offset_int rem2 = adata2.src.size_remaining (); | |
2701 | ||
2702 | /* Cap REM1 and REM2 at the other if the other's argument is known | |
2703 | to be an unterminated array, either because there's no space | |
2704 | left in it after adding its offset or because it's constant and | |
2705 | has no nul. */ | |
2706 | if (rem1 == 0 || (rem1 < rem2 && lendata1.decl)) | |
2707 | rem2 = rem1; | |
2708 | else if (rem2 == 0 || (rem2 < rem1 && lendata2.decl)) | |
2709 | rem1 = rem2; | |
2710 | ||
2711 | /* Point PAD at the array to reference in the note if a warning | |
2712 | is issued. */ | |
2713 | access_data *pad = len1 ? &adata2 : &adata1; | |
2714 | offset_int maxrem = wi::max (rem1, rem2, UNSIGNED); | |
2715 | if (lendata1.decl || lendata2.decl | |
2716 | || maxrem < wi::to_offset (bndrng[0])) | |
2717 | { | |
2718 | /* Warn when either argument isn't nul-terminated or the maximum | |
2719 | remaining space in the two arrays is less than the bound. */ | |
2720 | tree func = get_callee_fndecl (stmt); | |
2721 | location_t loc = gimple_location (stmt); | |
2722 | maybe_warn_for_bound (OPT_Wstringop_overread, loc, stmt, func, | |
2723 | bndrng, wide_int_to_tree (sizetype, maxrem), | |
2724 | pad); | |
2725 | } | |
2726 | } | |
2727 | ||
ece28da9 MS |
2728 | /* Determine and check the sizes of the source and the destination |
2729 | of calls to __builtin_{bzero,memcpy,mempcpy,memset} calls. STMT is | |
2730 | the call statement, DEST is the destination argument, SRC is the source | |
2731 | argument or null, and SIZE is the number of bytes being accessed. Use | |
2732 | Object Size type-0 regardless of the OPT_Wstringop_overflow_ setting. | |
2733 | Return true on success (no overflow or invalid sizes), false otherwise. */ | |
2734 | ||
2735 | void | |
2736 | pass_waccess::check_memop_access (gimple *stmt, tree dest, tree src, tree size) | |
2737 | { | |
9d6a0f38 MS |
2738 | if (m_early_checks_p) |
2739 | return; | |
2740 | ||
ece28da9 MS |
2741 | /* For functions like memset and memcpy that operate on raw memory |
2742 | try to determine the size of the largest source and destination | |
2743 | object using type-0 Object Size regardless of the object size | |
2744 | type specified by the option. */ | |
9a27acc3 | 2745 | access_data data (m_ptr_qry.rvals, stmt, access_read_write); |
ece28da9 | 2746 | tree srcsize |
9a27acc3 MS |
2747 | = src ? compute_objsize (src, stmt, 0, &data.src, &m_ptr_qry) : NULL_TREE; |
2748 | tree dstsize = compute_objsize (dest, stmt, 0, &data.dst, &m_ptr_qry); | |
2749 | ||
2750 | check_access (stmt, size, /*maxread=*/NULL_TREE, srcsize, dstsize, | |
2751 | data.mode, &data, m_ptr_qry.rvals); | |
2752 | } | |
2753 | ||
2754 | /* A convenience wrapper for check_access to check access by a read-only | |
2755 | function like puts or strcmp. */ | |
2756 | ||
2757 | void | |
2758 | pass_waccess::check_read_access (gimple *stmt, tree src, | |
2759 | tree bound /* = NULL_TREE */, | |
2760 | int ost /* = 1 */) | |
2761 | { | |
9d6a0f38 | 2762 | if (m_early_checks_p || !warn_stringop_overread) |
9a27acc3 MS |
2763 | return; |
2764 | ||
2765 | if (bound && !useless_type_conversion_p (size_type_node, TREE_TYPE (bound))) | |
2766 | bound = fold_convert (size_type_node, bound); | |
2767 | ||
2768 | tree fndecl = get_callee_fndecl (stmt); | |
2769 | maybe_warn_nonstring_arg (fndecl, stmt); | |
ece28da9 | 2770 | |
9a27acc3 MS |
2771 | access_data data (m_ptr_qry.rvals, stmt, access_read_only, NULL_TREE, |
2772 | false, bound, true); | |
2773 | compute_objsize (src, stmt, ost, &data.src, &m_ptr_qry); | |
2774 | check_access (stmt, /*dstwrite=*/ NULL_TREE, /*maxread=*/ bound, | |
2775 | /*srcstr=*/ src, /*dstsize=*/ NULL_TREE, data.mode, | |
2776 | &data, m_ptr_qry.rvals); | |
ece28da9 MS |
2777 | } |
2778 | ||
5a431b60 MS |
2779 | /* Return true if memory model ORD is constant in the context of STMT and |
2780 | set *CSTVAL to the constant value. Otherwise return false. Warn for | |
2781 | invalid ORD. */ | |
2782 | ||
2783 | bool | |
2784 | memmodel_to_uhwi (tree ord, gimple *stmt, unsigned HOST_WIDE_INT *cstval) | |
2785 | { | |
2786 | unsigned HOST_WIDE_INT val; | |
2787 | ||
2788 | if (TREE_CODE (ord) == INTEGER_CST) | |
2789 | { | |
2790 | if (!tree_fits_uhwi_p (ord)) | |
2791 | return false; | |
2792 | val = tree_to_uhwi (ord); | |
2793 | } | |
2794 | else | |
2795 | { | |
2796 | /* Use the range query to determine constant values in the absence | |
4a1c20df | 2797 | of constant propagation (such as at -O0). */ |
45c8523d | 2798 | Value_Range rng (TREE_TYPE (ord)); |
5a431b60 | 2799 | if (!get_range_query (cfun)->range_of_expr (rng, ord, stmt) |
5a431b60 MS |
2800 | || !rng.singleton_p (&ord)) |
2801 | return false; | |
2802 | ||
2803 | wide_int lob = rng.lower_bound (); | |
2804 | if (!wi::fits_uhwi_p (lob)) | |
2805 | return false; | |
2806 | ||
2807 | val = lob.to_shwi (); | |
2808 | } | |
2809 | ||
2810 | if (targetm.memmodel_check) | |
2811 | /* This might warn for an invalid VAL but return a conservatively | |
2812 | valid result. */ | |
2813 | val = targetm.memmodel_check (val); | |
2814 | else if (val & ~MEMMODEL_MASK) | |
2815 | { | |
2816 | tree fndecl = gimple_call_fndecl (stmt); | |
2817 | location_t loc = gimple_location (stmt); | |
2818 | loc = expansion_point_location_if_in_system_header (loc); | |
2819 | ||
2820 | warning_at (loc, OPT_Winvalid_memory_model, | |
2821 | "unknown architecture specifier in memory model " | |
2822 | "%wi for %qD", val, fndecl); | |
2823 | return false; | |
2824 | } | |
2825 | ||
2826 | *cstval = val; | |
2827 | ||
2828 | return true; | |
2829 | } | |
2830 | ||
2831 | /* Valid memory model for each set of atomic built-in functions. */ | |
2832 | ||
2833 | struct memmodel_pair | |
2834 | { | |
2835 | memmodel modval; | |
2836 | const char* modname; | |
2837 | ||
2838 | #define MEMMODEL_PAIR(val, str) \ | |
2839 | { MEMMODEL_ ## val, "memory_order_" str } | |
2840 | }; | |
2841 | ||
2842 | /* Valid memory models in the order of increasing strength. */ | |
2843 | ||
2844 | static const memmodel_pair memory_models[] = | |
2845 | { MEMMODEL_PAIR (RELAXED, "relaxed"), | |
2846 | MEMMODEL_PAIR (SEQ_CST, "seq_cst"), | |
2847 | MEMMODEL_PAIR (ACQUIRE, "acquire"), | |
2848 | MEMMODEL_PAIR (CONSUME, "consume"), | |
2849 | MEMMODEL_PAIR (RELEASE, "release"), | |
2850 | MEMMODEL_PAIR (ACQ_REL, "acq_rel") | |
2851 | }; | |
2852 | ||
2853 | /* Return the name of the memory model VAL. */ | |
2854 | ||
2855 | static const char* | |
2856 | memmodel_name (unsigned HOST_WIDE_INT val) | |
2857 | { | |
2858 | val = memmodel_base (val); | |
2859 | ||
ca32b29e | 2860 | for (unsigned i = 0; i != ARRAY_SIZE (memory_models); ++i) |
5a431b60 MS |
2861 | { |
2862 | if (val == memory_models[i].modval) | |
2863 | return memory_models[i].modname; | |
2864 | } | |
2865 | return NULL; | |
2866 | } | |
2867 | ||
2868 | /* Indices of valid MEMORY_MODELS above for corresponding atomic operations. */ | |
2869 | static const unsigned char load_models[] = { 0, 1, 2, 3, UCHAR_MAX }; | |
2870 | static const unsigned char store_models[] = { 0, 1, 4, UCHAR_MAX }; | |
2871 | static const unsigned char xchg_models[] = { 0, 1, 3, 4, 5, UCHAR_MAX }; | |
2872 | static const unsigned char flag_clr_models[] = { 0, 1, 4, UCHAR_MAX }; | |
2873 | static const unsigned char all_models[] = { 0, 1, 2, 3, 4, 5, UCHAR_MAX }; | |
2874 | ||
2875 | /* Check the success memory model argument ORD_SUCS to the call STMT to | |
2876 | an atomic function and warn if it's invalid. If nonnull, also check | |
2877 | the failure memory model ORD_FAIL and warn if it's invalid. Return | |
2878 | true if a warning has been issued. */ | |
2879 | ||
2880 | bool | |
2881 | pass_waccess::maybe_warn_memmodel (gimple *stmt, tree ord_sucs, | |
2882 | tree ord_fail, const unsigned char *valid) | |
2883 | { | |
2884 | unsigned HOST_WIDE_INT sucs, fail = 0; | |
2885 | if (!memmodel_to_uhwi (ord_sucs, stmt, &sucs) | |
2886 | || (ord_fail && !memmodel_to_uhwi (ord_fail, stmt, &fail))) | |
2887 | return false; | |
2888 | ||
2889 | bool is_valid = false; | |
2890 | if (valid) | |
2891 | for (unsigned i = 0; valid[i] != UCHAR_MAX; ++i) | |
2892 | { | |
2893 | memmodel model = memory_models[valid[i]].modval; | |
2894 | if (memmodel_base (sucs) == model) | |
2895 | { | |
2896 | is_valid = true; | |
2897 | break; | |
2898 | } | |
2899 | } | |
2900 | else | |
2901 | is_valid = true; | |
2902 | ||
2903 | tree fndecl = gimple_call_fndecl (stmt); | |
2904 | location_t loc = gimple_location (stmt); | |
2905 | loc = expansion_point_location_if_in_system_header (loc); | |
2906 | ||
2907 | if (!is_valid) | |
2908 | { | |
2909 | bool warned = false; | |
6ab98d8b | 2910 | auto_diagnostic_group d; |
5a431b60 MS |
2911 | if (const char *modname = memmodel_name (sucs)) |
2912 | warned = warning_at (loc, OPT_Winvalid_memory_model, | |
2913 | "invalid memory model %qs for %qD", | |
2914 | modname, fndecl); | |
2915 | else | |
2916 | warned = warning_at (loc, OPT_Winvalid_memory_model, | |
2917 | "invalid memory model %wi for %qD", | |
2918 | sucs, fndecl); | |
2919 | ||
2920 | if (!warned) | |
2921 | return false; | |
2922 | ||
2923 | /* Print a note with the valid memory models. */ | |
2924 | pretty_printer pp; | |
2925 | pp_show_color (&pp) = pp_show_color (global_dc->printer); | |
2926 | for (unsigned i = 0; valid[i] != UCHAR_MAX; ++i) | |
2927 | { | |
2928 | const char *modname = memory_models[valid[i]].modname; | |
194f712f | 2929 | pp_printf (&pp, "%s%qs", i ? ", " : "", modname); |
5a431b60 MS |
2930 | } |
2931 | ||
2932 | inform (loc, "valid models are %s", pp_formatted_text (&pp)); | |
2933 | return true; | |
2934 | } | |
2935 | ||
2936 | if (!ord_fail) | |
2937 | return false; | |
2938 | ||
2939 | if (fail == MEMMODEL_RELEASE || fail == MEMMODEL_ACQ_REL) | |
2940 | if (const char *failname = memmodel_name (fail)) | |
2941 | { | |
2942 | /* If both memory model arguments are valid but their combination | |
2943 | is not, use their names in the warning. */ | |
6ab98d8b | 2944 | auto_diagnostic_group d; |
5a431b60 MS |
2945 | if (!warning_at (loc, OPT_Winvalid_memory_model, |
2946 | "invalid failure memory model %qs for %qD", | |
2947 | failname, fndecl)) | |
2948 | return false; | |
2949 | ||
2950 | inform (loc, | |
2951 | "valid failure models are %qs, %qs, %qs, %qs", | |
2952 | "memory_order_relaxed", "memory_order_seq_cst", | |
2953 | "memory_order_acquire", "memory_order_consume"); | |
2954 | return true; | |
2955 | } | |
2956 | ||
2957 | if (memmodel_base (fail) <= memmodel_base (sucs)) | |
2958 | return false; | |
2959 | ||
2960 | if (const char *sucsname = memmodel_name (sucs)) | |
2961 | if (const char *failname = memmodel_name (fail)) | |
2962 | { | |
2963 | /* If both memory model arguments are valid but their combination | |
2964 | is not, use their names in the warning. */ | |
6ab98d8b | 2965 | auto_diagnostic_group d; |
5a431b60 MS |
2966 | if (!warning_at (loc, OPT_Winvalid_memory_model, |
2967 | "failure memory model %qs cannot be stronger " | |
2968 | "than success memory model %qs for %qD", | |
2969 | failname, sucsname, fndecl)) | |
2970 | return false; | |
2971 | ||
2972 | /* Print a note with the valid failure memory models which are | |
2973 | those with a value less than or equal to the success mode. */ | |
2974 | char buf[120]; | |
2975 | *buf = '\0'; | |
2976 | for (unsigned i = 0; | |
2977 | memory_models[i].modval <= memmodel_base (sucs); ++i) | |
2978 | { | |
2979 | if (*buf) | |
2980 | strcat (buf, ", "); | |
2981 | ||
2982 | const char *modname = memory_models[valid[i]].modname; | |
2983 | sprintf (buf + strlen (buf), "'%s'", modname); | |
2984 | } | |
2985 | ||
2986 | inform (loc, "valid models are %s", buf); | |
2987 | return true; | |
2988 | } | |
2989 | ||
2990 | /* If either memory model argument value is invalid use the numerical | |
2991 | value of both in the message. */ | |
2992 | return warning_at (loc, OPT_Winvalid_memory_model, | |
2993 | "failure memory model %wi cannot be stronger " | |
2994 | "than success memory model %wi for %qD", | |
2995 | fail, sucs, fndecl); | |
2996 | } | |
2997 | ||
2998 | /* Wrapper for the above. */ | |
2999 | ||
3000 | void | |
3001 | pass_waccess::check_atomic_memmodel (gimple *stmt, tree ord_sucs, | |
3002 | tree ord_fail, const unsigned char *valid) | |
3003 | { | |
3004 | if (warning_suppressed_p (stmt, OPT_Winvalid_memory_model)) | |
3005 | return; | |
3006 | ||
9d6a0f38 | 3007 | if (!maybe_warn_memmodel (stmt, ord_sucs, ord_fail, valid)) |
5a431b60 MS |
3008 | return; |
3009 | ||
3010 | suppress_warning (stmt, OPT_Winvalid_memory_model); | |
3011 | } | |
9a27acc3 | 3012 | |
88b504b7 MS |
3013 | /* Check a call STMT to an atomic or sync built-in. */ |
3014 | ||
3015 | bool | |
3016 | pass_waccess::check_atomic_builtin (gcall *stmt) | |
3017 | { | |
3018 | tree callee = gimple_call_fndecl (stmt); | |
3019 | if (!callee) | |
3020 | return false; | |
3021 | ||
3022 | /* The size in bytes of the access by the function, and the number | |
3023 | of the second argument to check (if any). */ | |
3024 | unsigned bytes = 0, arg2 = UINT_MAX; | |
5a431b60 MS |
3025 | unsigned sucs_arg = UINT_MAX, fail_arg = UINT_MAX; |
3026 | /* Points to the array of indices of valid memory models. */ | |
3027 | const unsigned char *pvalid_models = NULL; | |
88b504b7 MS |
3028 | |
3029 | switch (DECL_FUNCTION_CODE (callee)) | |
3030 | { | |
3031 | #define BUILTIN_ACCESS_SIZE_FNSPEC(N) \ | |
5a431b60 | 3032 | BUILT_IN_SYNC_FETCH_AND_ADD_ ## N: \ |
88b504b7 MS |
3033 | case BUILT_IN_SYNC_FETCH_AND_SUB_ ## N: \ |
3034 | case BUILT_IN_SYNC_FETCH_AND_OR_ ## N: \ | |
3035 | case BUILT_IN_SYNC_FETCH_AND_AND_ ## N: \ | |
3036 | case BUILT_IN_SYNC_FETCH_AND_XOR_ ## N: \ | |
3037 | case BUILT_IN_SYNC_FETCH_AND_NAND_ ## N: \ | |
3038 | case BUILT_IN_SYNC_ADD_AND_FETCH_ ## N: \ | |
3039 | case BUILT_IN_SYNC_SUB_AND_FETCH_ ## N: \ | |
3040 | case BUILT_IN_SYNC_OR_AND_FETCH_ ## N: \ | |
3041 | case BUILT_IN_SYNC_AND_AND_FETCH_ ## N: \ | |
3042 | case BUILT_IN_SYNC_XOR_AND_FETCH_ ## N: \ | |
3043 | case BUILT_IN_SYNC_NAND_AND_FETCH_ ## N: \ | |
3044 | case BUILT_IN_SYNC_LOCK_TEST_AND_SET_ ## N: \ | |
3045 | case BUILT_IN_SYNC_BOOL_COMPARE_AND_SWAP_ ## N: \ | |
3046 | case BUILT_IN_SYNC_VAL_COMPARE_AND_SWAP_ ## N: \ | |
3047 | case BUILT_IN_SYNC_LOCK_RELEASE_ ## N: \ | |
5a431b60 MS |
3048 | bytes = N; \ |
3049 | break; \ | |
3050 | case BUILT_IN_ATOMIC_LOAD_ ## N: \ | |
3051 | pvalid_models = load_models; \ | |
3052 | sucs_arg = 1; \ | |
3053 | /* FALLTHROUGH */ \ | |
88b504b7 | 3054 | case BUILT_IN_ATOMIC_STORE_ ## N: \ |
5a431b60 MS |
3055 | if (!pvalid_models) \ |
3056 | pvalid_models = store_models; \ | |
3057 | /* FALLTHROUGH */ \ | |
88b504b7 MS |
3058 | case BUILT_IN_ATOMIC_ADD_FETCH_ ## N: \ |
3059 | case BUILT_IN_ATOMIC_SUB_FETCH_ ## N: \ | |
3060 | case BUILT_IN_ATOMIC_AND_FETCH_ ## N: \ | |
3061 | case BUILT_IN_ATOMIC_NAND_FETCH_ ## N: \ | |
3062 | case BUILT_IN_ATOMIC_XOR_FETCH_ ## N: \ | |
3063 | case BUILT_IN_ATOMIC_OR_FETCH_ ## N: \ | |
3064 | case BUILT_IN_ATOMIC_FETCH_ADD_ ## N: \ | |
3065 | case BUILT_IN_ATOMIC_FETCH_SUB_ ## N: \ | |
3066 | case BUILT_IN_ATOMIC_FETCH_AND_ ## N: \ | |
3067 | case BUILT_IN_ATOMIC_FETCH_NAND_ ## N: \ | |
3068 | case BUILT_IN_ATOMIC_FETCH_OR_ ## N: \ | |
3069 | case BUILT_IN_ATOMIC_FETCH_XOR_ ## N: \ | |
3070 | bytes = N; \ | |
5a431b60 MS |
3071 | if (sucs_arg == UINT_MAX) \ |
3072 | sucs_arg = 2; \ | |
3073 | if (!pvalid_models) \ | |
3074 | pvalid_models = all_models; \ | |
3075 | break; \ | |
3076 | case BUILT_IN_ATOMIC_EXCHANGE_ ## N: \ | |
3077 | bytes = N; \ | |
3078 | sucs_arg = 3; \ | |
3079 | pvalid_models = xchg_models; \ | |
88b504b7 MS |
3080 | break; \ |
3081 | case BUILT_IN_ATOMIC_COMPARE_EXCHANGE_ ## N: \ | |
3082 | bytes = N; \ | |
5a431b60 MS |
3083 | sucs_arg = 4; \ |
3084 | fail_arg = 5; \ | |
3085 | pvalid_models = all_models; \ | |
88b504b7 MS |
3086 | arg2 = 1 |
3087 | ||
3088 | case BUILTIN_ACCESS_SIZE_FNSPEC (1); | |
3089 | break; | |
3090 | case BUILTIN_ACCESS_SIZE_FNSPEC (2); | |
3091 | break; | |
3092 | case BUILTIN_ACCESS_SIZE_FNSPEC (4); | |
3093 | break; | |
3094 | case BUILTIN_ACCESS_SIZE_FNSPEC (8); | |
3095 | break; | |
3096 | case BUILTIN_ACCESS_SIZE_FNSPEC (16); | |
3097 | break; | |
3098 | ||
5a431b60 MS |
3099 | case BUILT_IN_ATOMIC_CLEAR: |
3100 | sucs_arg = 1; | |
3101 | pvalid_models = flag_clr_models; | |
3102 | break; | |
3103 | ||
88b504b7 MS |
3104 | default: |
3105 | return false; | |
3106 | } | |
3107 | ||
5a431b60 MS |
3108 | unsigned nargs = gimple_call_num_args (stmt); |
3109 | if (sucs_arg < nargs) | |
3110 | { | |
3111 | tree ord_sucs = gimple_call_arg (stmt, sucs_arg); | |
3112 | tree ord_fail = NULL_TREE; | |
3113 | if (fail_arg < nargs) | |
3114 | ord_fail = gimple_call_arg (stmt, fail_arg); | |
3115 | check_atomic_memmodel (stmt, ord_sucs, ord_fail, pvalid_models); | |
3116 | } | |
3117 | ||
3118 | if (!bytes) | |
3119 | return true; | |
3120 | ||
88b504b7 MS |
3121 | tree size = build_int_cstu (sizetype, bytes); |
3122 | tree dst = gimple_call_arg (stmt, 0); | |
3123 | check_memop_access (stmt, dst, NULL_TREE, size); | |
3124 | ||
3125 | if (arg2 != UINT_MAX) | |
3126 | { | |
3127 | tree dst = gimple_call_arg (stmt, arg2); | |
3128 | check_memop_access (stmt, dst, NULL_TREE, size); | |
3129 | } | |
3130 | ||
3131 | return true; | |
3132 | } | |
3133 | ||
81d6cdd3 MS |
3134 | /* Check call STMT to a built-in function for invalid accesses. Return |
3135 | true if a call has been handled. */ | |
3136 | ||
3137 | bool | |
3138 | pass_waccess::check_builtin (gcall *stmt) | |
3139 | { | |
3140 | tree callee = gimple_call_fndecl (stmt); | |
3141 | if (!callee) | |
3142 | return false; | |
3143 | ||
3144 | switch (DECL_FUNCTION_CODE (callee)) | |
3145 | { | |
b48d4e68 MS |
3146 | case BUILT_IN_ALLOCA: |
3147 | case BUILT_IN_ALLOCA_WITH_ALIGN: | |
3148 | case BUILT_IN_ALLOCA_WITH_ALIGN_AND_MAX: | |
3149 | check_alloca (stmt); | |
3150 | return true; | |
3151 | ||
9a27acc3 MS |
3152 | case BUILT_IN_EXECL: |
3153 | case BUILT_IN_EXECLE: | |
3154 | case BUILT_IN_EXECLP: | |
3155 | case BUILT_IN_EXECV: | |
3156 | case BUILT_IN_EXECVE: | |
3157 | case BUILT_IN_EXECVP: | |
3158 | check_read_access (stmt, call_arg (stmt, 0)); | |
3159 | return true; | |
3160 | ||
671a2836 MS |
3161 | case BUILT_IN_FREE: |
3162 | case BUILT_IN_REALLOC: | |
9d6a0f38 MS |
3163 | if (!m_early_checks_p) |
3164 | { | |
3165 | tree arg = call_arg (stmt, 0); | |
3166 | if (TREE_CODE (arg) == SSA_NAME) | |
3167 | check_pointer_uses (stmt, arg); | |
3168 | } | |
671a2836 MS |
3169 | return true; |
3170 | ||
81d6cdd3 MS |
3171 | case BUILT_IN_GETTEXT: |
3172 | case BUILT_IN_PUTS: | |
3173 | case BUILT_IN_PUTS_UNLOCKED: | |
3174 | case BUILT_IN_STRDUP: | |
3175 | check_read_access (stmt, call_arg (stmt, 0)); | |
3176 | return true; | |
3177 | ||
3178 | case BUILT_IN_INDEX: | |
3179 | case BUILT_IN_RINDEX: | |
3180 | case BUILT_IN_STRCHR: | |
3181 | case BUILT_IN_STRRCHR: | |
3182 | case BUILT_IN_STRLEN: | |
3183 | check_read_access (stmt, call_arg (stmt, 0)); | |
3184 | return true; | |
3185 | ||
3186 | case BUILT_IN_FPUTS: | |
3187 | case BUILT_IN_FPUTS_UNLOCKED: | |
3188 | check_read_access (stmt, call_arg (stmt, 0)); | |
3189 | return true; | |
3190 | ||
3191 | case BUILT_IN_STRNDUP: | |
3192 | case BUILT_IN_STRNLEN: | |
9a27acc3 MS |
3193 | { |
3194 | tree str = call_arg (stmt, 0); | |
3195 | tree len = call_arg (stmt, 1); | |
3196 | check_read_access (stmt, str, len); | |
3197 | return true; | |
3198 | } | |
81d6cdd3 MS |
3199 | |
3200 | case BUILT_IN_STRCAT: | |
3201 | check_strcat (stmt); | |
3202 | return true; | |
3203 | ||
3204 | case BUILT_IN_STRNCAT: | |
3205 | check_strncat (stmt); | |
3206 | return true; | |
3207 | ||
3208 | case BUILT_IN_STPCPY: | |
3209 | case BUILT_IN_STRCPY: | |
3210 | check_stxcpy (stmt); | |
3211 | return true; | |
3212 | ||
3213 | case BUILT_IN_STPNCPY: | |
3214 | case BUILT_IN_STRNCPY: | |
3215 | check_stxncpy (stmt); | |
3216 | return true; | |
3217 | ||
3218 | case BUILT_IN_STRCASECMP: | |
3219 | case BUILT_IN_STRCMP: | |
3220 | case BUILT_IN_STRPBRK: | |
3221 | case BUILT_IN_STRSPN: | |
3222 | case BUILT_IN_STRCSPN: | |
3223 | case BUILT_IN_STRSTR: | |
3224 | check_read_access (stmt, call_arg (stmt, 0)); | |
3225 | check_read_access (stmt, call_arg (stmt, 1)); | |
3226 | return true; | |
3227 | ||
3228 | case BUILT_IN_STRNCASECMP: | |
3229 | case BUILT_IN_STRNCMP: | |
3230 | check_strncmp (stmt); | |
3231 | return true; | |
3232 | ||
3233 | case BUILT_IN_MEMCMP: | |
3234 | { | |
3235 | tree a1 = call_arg (stmt, 0); | |
3236 | tree a2 = call_arg (stmt, 1); | |
3237 | tree len = call_arg (stmt, 2); | |
3238 | check_read_access (stmt, a1, len, 0); | |
3239 | check_read_access (stmt, a2, len, 0); | |
3240 | return true; | |
3241 | } | |
3242 | ||
3243 | case BUILT_IN_MEMCPY: | |
3244 | case BUILT_IN_MEMPCPY: | |
3245 | case BUILT_IN_MEMMOVE: | |
3246 | { | |
3247 | tree dst = call_arg (stmt, 0); | |
3248 | tree src = call_arg (stmt, 1); | |
3249 | tree len = call_arg (stmt, 2); | |
3250 | check_memop_access (stmt, dst, src, len); | |
3251 | return true; | |
3252 | } | |
3253 | ||
3254 | case BUILT_IN_MEMCHR: | |
3255 | { | |
3256 | tree src = call_arg (stmt, 0); | |
3257 | tree len = call_arg (stmt, 2); | |
3258 | check_read_access (stmt, src, len, 0); | |
3259 | return true; | |
3260 | } | |
3261 | ||
3262 | case BUILT_IN_MEMSET: | |
3263 | { | |
3264 | tree dst = call_arg (stmt, 0); | |
3265 | tree len = call_arg (stmt, 2); | |
3266 | check_memop_access (stmt, dst, NULL_TREE, len); | |
3267 | return true; | |
3268 | } | |
3269 | ||
3270 | default: | |
88b504b7 MS |
3271 | if (check_atomic_builtin (stmt)) |
3272 | return true; | |
3273 | break; | |
81d6cdd3 | 3274 | } |
671a2836 | 3275 | |
88b504b7 | 3276 | return false; |
81d6cdd3 MS |
3277 | } |
3278 | ||
b48d4e68 | 3279 | /* Returns the type of the argument ARGNO to function with type FNTYPE |
4a1c20df | 3280 | or null when the type cannot be determined or no such argument exists. */ |
b48d4e68 MS |
3281 | |
3282 | static tree | |
3283 | fntype_argno_type (tree fntype, unsigned argno) | |
3284 | { | |
3285 | if (!prototype_p (fntype)) | |
3286 | return NULL_TREE; | |
3287 | ||
3288 | tree argtype; | |
3289 | function_args_iterator it; | |
3290 | FOREACH_FUNCTION_ARGS (fntype, argtype, it) | |
3291 | if (argno-- == 0) | |
3292 | return argtype; | |
3293 | ||
3294 | return NULL_TREE; | |
3295 | } | |
3296 | ||
3297 | /* Helper to append the "human readable" attribute access specification | |
3298 | described by ACCESS to the array ATTRSTR with size STRSIZE. Used in | |
3299 | diagnostics. */ | |
3300 | ||
3301 | static inline void | |
3302 | append_attrname (const std::pair<int, attr_access> &access, | |
3303 | char *attrstr, size_t strsize) | |
3304 | { | |
3305 | if (access.second.internal_p) | |
3306 | return; | |
3307 | ||
3308 | tree str = access.second.to_external_string (); | |
3309 | gcc_assert (strsize >= (size_t) TREE_STRING_LENGTH (str)); | |
3310 | strcpy (attrstr, TREE_STRING_POINTER (str)); | |
3311 | } | |
3312 | ||
3313 | /* Iterate over attribute access read-only, read-write, and write-only | |
3314 | arguments and diagnose past-the-end accesses and related problems | |
3315 | in the function call EXP. */ | |
3316 | ||
ece28da9 MS |
3317 | void |
3318 | pass_waccess::maybe_check_access_sizes (rdwr_map *rwm, tree fndecl, tree fntype, | |
3319 | gimple *stmt) | |
b48d4e68 MS |
3320 | { |
3321 | auto_diagnostic_group adg; | |
3322 | ||
3323 | /* Set if a warning has been issued for any argument (used to decide | |
3324 | whether to emit an informational note at the end). */ | |
3325 | opt_code opt_warned = no_warning; | |
3326 | ||
3327 | /* A string describing the attributes that the warnings issued by this | |
3328 | function apply to. Used to print one informational note per function | |
3329 | call, rather than one per warning. That reduces clutter. */ | |
3330 | char attrstr[80]; | |
3331 | attrstr[0] = 0; | |
3332 | ||
3333 | for (rdwr_map::iterator it = rwm->begin (); it != rwm->end (); ++it) | |
3334 | { | |
3335 | std::pair<int, attr_access> access = *it; | |
3336 | ||
3337 | /* Get the function call arguments corresponding to the attribute's | |
3338 | positional arguments. When both arguments have been specified | |
3339 | there will be two entries in *RWM, one for each. They are | |
3340 | cross-referenced by their respective argument numbers in | |
3341 | ACCESS.PTRARG and ACCESS.SIZARG. */ | |
3342 | const int ptridx = access.second.ptrarg; | |
3343 | const int sizidx = access.second.sizarg; | |
3344 | ||
3345 | gcc_assert (ptridx != -1); | |
3346 | gcc_assert (access.first == ptridx || access.first == sizidx); | |
3347 | ||
3348 | /* The pointer is set to null for the entry corresponding to | |
3349 | the size argument. Skip it. It's handled when the entry | |
3350 | corresponding to the pointer argument comes up. */ | |
3351 | if (!access.second.ptr) | |
3352 | continue; | |
3353 | ||
3354 | tree ptrtype = fntype_argno_type (fntype, ptridx); | |
ea9e0d6c MS |
3355 | if (!ptrtype) |
3356 | /* A function with a prototype was redeclared without one and | |
4a1c20df | 3357 | the prototype has been lost. See pr102759. Avoid dealing |
ea9e0d6c MS |
3358 | with this pathological case. */ |
3359 | return; | |
3360 | ||
b48d4e68 MS |
3361 | tree argtype = TREE_TYPE (ptrtype); |
3362 | ||
ea9e0d6c MS |
3363 | /* The size of the access by the call in elements. */ |
3364 | tree access_nelts; | |
b48d4e68 MS |
3365 | if (sizidx == -1) |
3366 | { | |
3367 | /* If only the pointer attribute operand was specified and | |
3368 | not size, set SIZE to the greater of MINSIZE or size of | |
3369 | one element of the pointed to type to detect smaller | |
3370 | objects (null pointers are diagnosed in this case only | |
3371 | if the pointer is also declared with attribute nonnull. */ | |
3372 | if (access.second.minsize | |
3373 | && access.second.minsize != HOST_WIDE_INT_M1U) | |
ea9e0d6c | 3374 | access_nelts = build_int_cstu (sizetype, access.second.minsize); |
9eeca99c MS |
3375 | else if (VOID_TYPE_P (argtype) && access.second.mode == access_none) |
3376 | /* Treat access mode none on a void* argument as expecting | |
3377 | as little as zero bytes. */ | |
3378 | access_nelts = size_zero_node; | |
b48d4e68 | 3379 | else |
ea9e0d6c | 3380 | access_nelts = size_one_node; |
b48d4e68 MS |
3381 | } |
3382 | else | |
ea9e0d6c | 3383 | access_nelts = rwm->get (sizidx)->size; |
b48d4e68 MS |
3384 | |
3385 | /* Format the value or range to avoid an explosion of messages. */ | |
3386 | char sizstr[80]; | |
3387 | tree sizrng[2] = { size_zero_node, build_all_ones_cst (sizetype) }; | |
ea9e0d6c | 3388 | if (get_size_range (m_ptr_qry.rvals, access_nelts, stmt, sizrng, 1)) |
b48d4e68 MS |
3389 | { |
3390 | char *s0 = print_generic_expr_to_str (sizrng[0]); | |
3391 | if (tree_int_cst_equal (sizrng[0], sizrng[1])) | |
3392 | { | |
3393 | gcc_checking_assert (strlen (s0) < sizeof sizstr); | |
3394 | strcpy (sizstr, s0); | |
3395 | } | |
3396 | else | |
3397 | { | |
3398 | char *s1 = print_generic_expr_to_str (sizrng[1]); | |
3399 | gcc_checking_assert (strlen (s0) + strlen (s1) | |
3400 | < sizeof sizstr - 4); | |
6b8b9596 | 3401 | sprintf (sizstr, "[%.37s, %.37s]", s0, s1); |
b48d4e68 MS |
3402 | free (s1); |
3403 | } | |
3404 | free (s0); | |
3405 | } | |
3406 | else | |
3407 | *sizstr = '\0'; | |
3408 | ||
3409 | /* Set if a warning has been issued for the current argument. */ | |
3410 | opt_code arg_warned = no_warning; | |
3411 | location_t loc = get_location (stmt); | |
3412 | tree ptr = access.second.ptr; | |
3413 | if (*sizstr | |
3414 | && tree_int_cst_sgn (sizrng[0]) < 0 | |
3415 | && tree_int_cst_sgn (sizrng[1]) < 0) | |
3416 | { | |
3417 | /* Warn about negative sizes. */ | |
3418 | if (access.second.internal_p) | |
3419 | { | |
3420 | const std::string argtypestr | |
3421 | = access.second.array_as_string (ptrtype); | |
3422 | ||
3423 | if (warning_at (loc, OPT_Wstringop_overflow_, | |
3424 | "bound argument %i value %s is " | |
3425 | "negative for a variable length array " | |
3426 | "argument %i of type %s", | |
3427 | sizidx + 1, sizstr, | |
3428 | ptridx + 1, argtypestr.c_str ())) | |
3429 | arg_warned = OPT_Wstringop_overflow_; | |
3430 | } | |
3431 | else if (warning_at (loc, OPT_Wstringop_overflow_, | |
3432 | "argument %i value %s is negative", | |
3433 | sizidx + 1, sizstr)) | |
3434 | arg_warned = OPT_Wstringop_overflow_; | |
3435 | ||
3436 | if (arg_warned != no_warning) | |
3437 | { | |
3438 | append_attrname (access, attrstr, sizeof attrstr); | |
3439 | /* Remember a warning has been issued and avoid warning | |
3440 | again below for the same attribute. */ | |
3441 | opt_warned = arg_warned; | |
3442 | continue; | |
3443 | } | |
3444 | } | |
3445 | ||
ea9e0d6c MS |
3446 | /* The size of the access by the call in bytes. */ |
3447 | tree access_size = NULL_TREE; | |
b48d4e68 MS |
3448 | if (tree_int_cst_sgn (sizrng[0]) >= 0) |
3449 | { | |
3450 | if (COMPLETE_TYPE_P (argtype)) | |
3451 | { | |
3452 | /* Multiply ACCESS_SIZE by the size of the type the pointer | |
3453 | argument points to. If it's incomplete the size is used | |
3454 | as is. */ | |
3455 | if (tree argsize = TYPE_SIZE_UNIT (argtype)) | |
3456 | if (TREE_CODE (argsize) == INTEGER_CST) | |
3457 | { | |
3458 | const int prec = TYPE_PRECISION (sizetype); | |
3459 | wide_int minsize = wi::to_wide (sizrng[0], prec); | |
3460 | minsize *= wi::to_wide (argsize, prec); | |
3461 | access_size = wide_int_to_tree (sizetype, minsize); | |
3462 | } | |
3463 | } | |
ea9e0d6c MS |
3464 | else |
3465 | access_size = access_nelts; | |
b48d4e68 | 3466 | } |
b48d4e68 MS |
3467 | |
3468 | if (integer_zerop (ptr)) | |
3469 | { | |
3470 | if (sizidx >= 0 && tree_int_cst_sgn (sizrng[0]) > 0) | |
3471 | { | |
3472 | /* Warn about null pointers with positive sizes. This is | |
3473 | different from also declaring the pointer argument with | |
3474 | attribute nonnull when the function accepts null pointers | |
3475 | only when the corresponding size is zero. */ | |
3476 | if (access.second.internal_p) | |
3477 | { | |
3478 | const std::string argtypestr | |
3479 | = access.second.array_as_string (ptrtype); | |
3480 | ||
3481 | if (warning_at (loc, OPT_Wnonnull, | |
3482 | "argument %i of variable length " | |
3483 | "array %s is null but " | |
3484 | "the corresponding bound argument " | |
3485 | "%i value is %s", | |
3486 | ptridx + 1, argtypestr.c_str (), | |
3487 | sizidx + 1, sizstr)) | |
3488 | arg_warned = OPT_Wnonnull; | |
3489 | } | |
3490 | else if (warning_at (loc, OPT_Wnonnull, | |
3491 | "argument %i is null but " | |
3492 | "the corresponding size argument " | |
3493 | "%i value is %s", | |
3494 | ptridx + 1, sizidx + 1, sizstr)) | |
3495 | arg_warned = OPT_Wnonnull; | |
3496 | } | |
3497 | else if (access_size && access.second.static_p) | |
3498 | { | |
3499 | /* Warn about null pointers for [static N] array arguments | |
3500 | but do not warn for ordinary (i.e., nonstatic) arrays. */ | |
3501 | if (warning_at (loc, OPT_Wnonnull, | |
3502 | "argument %i to %<%T[static %E]%> " | |
3503 | "is null where non-null expected", | |
3504 | ptridx + 1, argtype, access_size)) | |
3505 | arg_warned = OPT_Wnonnull; | |
3506 | } | |
3507 | ||
3508 | if (arg_warned != no_warning) | |
3509 | { | |
3510 | append_attrname (access, attrstr, sizeof attrstr); | |
3511 | /* Remember a warning has been issued and avoid warning | |
3512 | again below for the same attribute. */ | |
3513 | opt_warned = OPT_Wnonnull; | |
3514 | continue; | |
3515 | } | |
3516 | } | |
3517 | ||
9a27acc3 MS |
3518 | access_data data (m_ptr_qry.rvals, stmt, access.second.mode, |
3519 | NULL_TREE, false, NULL_TREE, false); | |
b48d4e68 MS |
3520 | access_ref* const pobj = (access.second.mode == access_write_only |
3521 | ? &data.dst : &data.src); | |
9a27acc3 | 3522 | tree objsize = compute_objsize (ptr, stmt, 1, pobj, &m_ptr_qry); |
b48d4e68 MS |
3523 | |
3524 | /* The size of the destination or source object. */ | |
3525 | tree dstsize = NULL_TREE, srcsize = NULL_TREE; | |
3526 | if (access.second.mode == access_read_only | |
3527 | || access.second.mode == access_none) | |
3528 | { | |
3529 | /* For a read-only argument there is no destination. For | |
3530 | no access, set the source as well and differentiate via | |
3531 | the access flag below. */ | |
3532 | srcsize = objsize; | |
3533 | if (access.second.mode == access_read_only | |
3534 | || access.second.mode == access_none) | |
3535 | { | |
3536 | /* For a read-only attribute there is no destination so | |
3537 | clear OBJSIZE. This emits "reading N bytes" kind of | |
3538 | diagnostics instead of the "writing N bytes" kind, | |
3539 | unless MODE is none. */ | |
3540 | objsize = NULL_TREE; | |
3541 | } | |
3542 | } | |
3543 | else | |
3544 | dstsize = objsize; | |
3545 | ||
3546 | /* Clear the no-warning bit in case it was set by check_access | |
3547 | in a prior iteration so that accesses via different arguments | |
3548 | are diagnosed. */ | |
3549 | suppress_warning (stmt, OPT_Wstringop_overflow_, false); | |
3550 | access_mode mode = data.mode; | |
3551 | if (mode == access_deferred) | |
3552 | mode = TYPE_READONLY (argtype) ? access_read_only : access_read_write; | |
3553 | check_access (stmt, access_size, /*maxread=*/ NULL_TREE, srcsize, | |
9a27acc3 | 3554 | dstsize, mode, &data, m_ptr_qry.rvals); |
b48d4e68 MS |
3555 | |
3556 | if (warning_suppressed_p (stmt, OPT_Wstringop_overflow_)) | |
3557 | opt_warned = OPT_Wstringop_overflow_; | |
3558 | if (opt_warned != no_warning) | |
3559 | { | |
3560 | if (access.second.internal_p) | |
ea9e0d6c MS |
3561 | { |
3562 | unsigned HOST_WIDE_INT nelts = | |
3563 | access_nelts ? access.second.minsize : HOST_WIDE_INT_M1U; | |
3564 | tree arrtype = build_printable_array_type (argtype, nelts); | |
3565 | inform (loc, "referencing argument %u of type %qT", | |
3566 | ptridx + 1, arrtype); | |
3567 | } | |
b48d4e68 MS |
3568 | else |
3569 | /* If check_access issued a warning above, append the relevant | |
3570 | attribute to the string. */ | |
3571 | append_attrname (access, attrstr, sizeof attrstr); | |
3572 | } | |
3573 | } | |
3574 | ||
3575 | if (*attrstr) | |
3576 | { | |
3577 | if (fndecl) | |
3578 | inform (get_location (fndecl), | |
3579 | "in a call to function %qD declared with attribute %qs", | |
3580 | fndecl, attrstr); | |
3581 | else | |
3582 | inform (get_location (stmt), | |
3583 | "in a call with type %qT and attribute %qs", | |
3584 | fntype, attrstr); | |
3585 | } | |
3586 | else if (opt_warned != no_warning) | |
3587 | { | |
3588 | if (fndecl) | |
3589 | inform (get_location (fndecl), | |
3590 | "in a call to function %qD", fndecl); | |
3591 | else | |
3592 | inform (get_location (stmt), | |
3593 | "in a call with type %qT", fntype); | |
3594 | } | |
3595 | ||
3596 | /* Set the bit in case if was cleared and not set above. */ | |
3597 | if (opt_warned != no_warning) | |
3598 | suppress_warning (stmt, opt_warned); | |
3599 | } | |
3600 | ||
3601 | /* Check call STMT to an ordinary (non-built-in) function for invalid | |
3602 | accesses. Return true if a call has been handled. */ | |
3603 | ||
3604 | bool | |
671a2836 | 3605 | pass_waccess::check_call_access (gcall *stmt) |
b48d4e68 MS |
3606 | { |
3607 | tree fntype = gimple_call_fntype (stmt); | |
3608 | if (!fntype) | |
3609 | return false; | |
3610 | ||
3611 | tree fntypeattrs = TYPE_ATTRIBUTES (fntype); | |
3612 | if (!fntypeattrs) | |
3613 | return false; | |
3614 | ||
4a1c20df | 3615 | /* Map of attribute access specifications for function arguments. */ |
b48d4e68 MS |
3616 | rdwr_map rdwr_idx; |
3617 | init_attr_rdwr_indices (&rdwr_idx, fntypeattrs); | |
3618 | ||
3619 | unsigned nargs = call_nargs (stmt); | |
3620 | for (unsigned i = 0; i != nargs; ++i) | |
3621 | { | |
3622 | tree arg = call_arg (stmt, i); | |
3623 | ||
3624 | /* Save the actual argument that corresponds to the access attribute | |
3625 | operand for later processing. */ | |
3626 | if (attr_access *access = rdwr_idx.get (i)) | |
3627 | { | |
3628 | if (POINTER_TYPE_P (TREE_TYPE (arg))) | |
3629 | { | |
3630 | access->ptr = arg; | |
4a1c20df | 3631 | /* A nonnull ACCESS->SIZE contains VLA bounds. */ |
b48d4e68 MS |
3632 | } |
3633 | else | |
3634 | { | |
3635 | access->size = arg; | |
3636 | gcc_assert (access->ptr == NULL_TREE); | |
3637 | } | |
3638 | } | |
3639 | } | |
3640 | ||
3641 | /* Check attribute access arguments. */ | |
3642 | tree fndecl = gimple_call_fndecl (stmt); | |
ece28da9 | 3643 | maybe_check_access_sizes (&rdwr_idx, fndecl, fntype, stmt); |
b48d4e68 MS |
3644 | |
3645 | check_alloc_size_call (stmt); | |
3646 | return true; | |
3647 | } | |
3648 | ||
3649 | /* Check arguments in a call STMT for attribute nonstring. */ | |
3650 | ||
3651 | static void | |
3652 | check_nonstring_args (gcall *stmt) | |
3653 | { | |
3654 | tree fndecl = gimple_call_fndecl (stmt); | |
3655 | ||
3656 | /* Detect passing non-string arguments to functions expecting | |
3657 | nul-terminated strings. */ | |
3658 | maybe_warn_nonstring_arg (fndecl, stmt); | |
3659 | } | |
3660 | ||
ece28da9 MS |
3661 | /* Issue a warning if a deallocation function such as free, realloc, |
3662 | or C++ operator delete is called with an argument not returned by | |
3663 | a matching allocation function such as malloc or the corresponding | |
4a1c20df | 3664 | form of C++ operator new. */ |
ece28da9 MS |
3665 | |
3666 | void | |
3667 | pass_waccess::maybe_check_dealloc_call (gcall *call) | |
3668 | { | |
3669 | tree fndecl = gimple_call_fndecl (call); | |
3670 | if (!fndecl) | |
3671 | return; | |
3672 | ||
3673 | unsigned argno = fndecl_dealloc_argno (fndecl); | |
3674 | if ((unsigned) call_nargs (call) <= argno) | |
3675 | return; | |
3676 | ||
3677 | tree ptr = gimple_call_arg (call, argno); | |
3678 | if (integer_zerop (ptr)) | |
3679 | return; | |
3680 | ||
3681 | access_ref aref; | |
9a27acc3 | 3682 | if (!compute_objsize (ptr, call, 0, &aref, &m_ptr_qry)) |
ece28da9 MS |
3683 | return; |
3684 | ||
3685 | tree ref = aref.ref; | |
3686 | if (integer_zerop (ref)) | |
3687 | return; | |
3688 | ||
3689 | tree dealloc_decl = fndecl; | |
3690 | location_t loc = gimple_location (call); | |
3691 | ||
3692 | if (DECL_P (ref) || EXPR_P (ref)) | |
3693 | { | |
3694 | /* Diagnose freeing a declared object. */ | |
6ab98d8b | 3695 | if (aref.ref_declared ()) |
ece28da9 | 3696 | { |
6ab98d8b DM |
3697 | auto_diagnostic_group d; |
3698 | if (warning_at (loc, OPT_Wfree_nonheap_object, | |
3699 | "%qD called on unallocated object %qD", | |
3700 | dealloc_decl, ref)) | |
3701 | { | |
3702 | inform (get_location (ref), "declared here"); | |
3703 | return; | |
3704 | } | |
ece28da9 MS |
3705 | } |
3706 | ||
3707 | /* Diagnose freeing a pointer that includes a positive offset. | |
3708 | Such a pointer cannot refer to the beginning of an allocated | |
3709 | object. A negative offset may refer to it. */ | |
3710 | if (aref.sizrng[0] != aref.sizrng[1] | |
3711 | && warn_dealloc_offset (loc, call, aref)) | |
3712 | return; | |
3713 | } | |
3714 | else if (CONSTANT_CLASS_P (ref)) | |
3715 | { | |
6ab98d8b | 3716 | auto_diagnostic_group d; |
ece28da9 MS |
3717 | if (warning_at (loc, OPT_Wfree_nonheap_object, |
3718 | "%qD called on a pointer to an unallocated " | |
3719 | "object %qE", dealloc_decl, ref)) | |
3720 | { | |
3721 | if (TREE_CODE (ptr) == SSA_NAME) | |
3722 | { | |
3723 | gimple *def_stmt = SSA_NAME_DEF_STMT (ptr); | |
3724 | if (is_gimple_assign (def_stmt)) | |
3725 | { | |
3726 | location_t loc = gimple_location (def_stmt); | |
3727 | inform (loc, "assigned here"); | |
3728 | } | |
3729 | } | |
3730 | return; | |
3731 | } | |
3732 | } | |
3733 | else if (TREE_CODE (ref) == SSA_NAME) | |
3734 | { | |
3735 | /* Also warn if the pointer argument refers to the result | |
3736 | of an allocation call like alloca or VLA. */ | |
3737 | gimple *def_stmt = SSA_NAME_DEF_STMT (ref); | |
3738 | if (!def_stmt) | |
3739 | return; | |
3740 | ||
3741 | if (is_gimple_call (def_stmt)) | |
3742 | { | |
3743 | bool warned = false; | |
3744 | if (gimple_call_alloc_p (def_stmt)) | |
3745 | { | |
3746 | if (matching_alloc_calls_p (def_stmt, dealloc_decl)) | |
3747 | { | |
3748 | if (warn_dealloc_offset (loc, call, aref)) | |
3749 | return; | |
3750 | } | |
3751 | else | |
3752 | { | |
3753 | tree alloc_decl = gimple_call_fndecl (def_stmt); | |
3754 | const opt_code opt = | |
3755 | (DECL_IS_OPERATOR_NEW_P (alloc_decl) | |
3756 | || DECL_IS_OPERATOR_DELETE_P (dealloc_decl) | |
3757 | ? OPT_Wmismatched_new_delete | |
3758 | : OPT_Wmismatched_dealloc); | |
3759 | warned = warning_at (loc, opt, | |
3760 | "%qD called on pointer returned " | |
3761 | "from a mismatched allocation " | |
3762 | "function", dealloc_decl); | |
3763 | } | |
3764 | } | |
3765 | else if (gimple_call_builtin_p (def_stmt, BUILT_IN_ALLOCA) | |
3766 | || gimple_call_builtin_p (def_stmt, | |
3767 | BUILT_IN_ALLOCA_WITH_ALIGN)) | |
3768 | warned = warning_at (loc, OPT_Wfree_nonheap_object, | |
3769 | "%qD called on pointer to " | |
3770 | "an unallocated object", | |
3771 | dealloc_decl); | |
3772 | else if (warn_dealloc_offset (loc, call, aref)) | |
3773 | return; | |
3774 | ||
3775 | if (warned) | |
3776 | { | |
3777 | tree fndecl = gimple_call_fndecl (def_stmt); | |
3778 | inform (gimple_location (def_stmt), | |
3779 | "returned from %qD", fndecl); | |
3780 | return; | |
3781 | } | |
3782 | } | |
3783 | else if (gimple_nop_p (def_stmt)) | |
3784 | { | |
3785 | ref = SSA_NAME_VAR (ref); | |
3786 | /* Diagnose freeing a pointer that includes a positive offset. */ | |
3787 | if (TREE_CODE (ref) == PARM_DECL | |
3788 | && !aref.deref | |
3789 | && aref.sizrng[0] != aref.sizrng[1] | |
3790 | && aref.offrng[0] > 0 && aref.offrng[1] > 0 | |
3791 | && warn_dealloc_offset (loc, call, aref)) | |
3792 | return; | |
3793 | } | |
3794 | } | |
3795 | } | |
3796 | ||
671a2836 MS |
3797 | /* Return true if either USE_STMT's basic block (that of a pointer's use) |
3798 | is dominated by INVAL_STMT's (that of a pointer's invalidating statement, | |
9d6a0f38 MS |
3799 | which is either a clobber or a deallocation call), or if they're in |
3800 | the same block, USE_STMT follows INVAL_STMT. */ | |
671a2836 MS |
3801 | |
3802 | bool | |
9d6a0f38 MS |
3803 | pass_waccess::use_after_inval_p (gimple *inval_stmt, gimple *use_stmt, |
3804 | bool last_block /* = false */) | |
671a2836 | 3805 | { |
9d6a0f38 MS |
3806 | tree clobvar = |
3807 | gimple_clobber_p (inval_stmt) ? gimple_assign_lhs (inval_stmt) : NULL_TREE; | |
3808 | ||
671a2836 MS |
3809 | basic_block inval_bb = gimple_bb (inval_stmt); |
3810 | basic_block use_bb = gimple_bb (use_stmt); | |
3811 | ||
9d6a0f38 MS |
3812 | if (!inval_bb || !use_bb) |
3813 | return false; | |
3814 | ||
671a2836 | 3815 | if (inval_bb != use_bb) |
9d6a0f38 MS |
3816 | { |
3817 | if (dominated_by_p (CDI_DOMINATORS, use_bb, inval_bb)) | |
3818 | return true; | |
3819 | ||
3820 | if (!clobvar || !last_block) | |
3821 | return false; | |
3822 | ||
3823 | /* Proceed only when looking for uses of dangling pointers. */ | |
3824 | auto gsi = gsi_for_stmt (use_stmt); | |
3825 | ||
9d6a0f38 MS |
3826 | /* A use statement in the last basic block in a function or one that |
3827 | falls through to it is after any other prior clobber of the used | |
3828 | variable unless it's followed by a clobber of the same variable. */ | |
3829 | basic_block bb = use_bb; | |
3830 | while (bb != inval_bb | |
3831 | && single_succ_p (bb) | |
dab41c9d JJ |
3832 | && !(single_succ_edge (bb)->flags |
3833 | & (EDGE_EH | EDGE_ABNORMAL | EDGE_DFS_BACK))) | |
9d6a0f38 | 3834 | { |
9d6a0f38 MS |
3835 | for (; !gsi_end_p (gsi); gsi_next_nondebug (&gsi)) |
3836 | { | |
3837 | gimple *stmt = gsi_stmt (gsi); | |
3838 | if (gimple_clobber_p (stmt)) | |
3839 | { | |
3840 | if (clobvar == gimple_assign_lhs (stmt)) | |
3841 | /* The use is followed by a clobber. */ | |
3842 | return false; | |
3843 | } | |
3844 | } | |
3845 | ||
3846 | bb = single_succ (bb); | |
3847 | gsi = gsi_start_bb (bb); | |
3848 | } | |
3849 | ||
3850 | /* The use is one of a dangling pointer if a clobber of the variable | |
3851 | [the pointer points to] has not been found before the function exit | |
3852 | point. */ | |
3853 | return bb == EXIT_BLOCK_PTR_FOR_FN (cfun); | |
3854 | } | |
671a2836 MS |
3855 | |
3856 | if (bitmap_set_bit (m_bb_uids_set, inval_bb->index)) | |
3857 | /* The first time this basic block is visited assign increasing ids | |
3858 | to consecutive statements in it. Use the ids to determine which | |
3859 | precedes which. This avoids the linear traversal on subsequent | |
3860 | visits to the same block. */ | |
3861 | for (auto si = gsi_start_bb (inval_bb); !gsi_end_p (si); | |
3862 | gsi_next_nondebug (&si)) | |
3863 | { | |
3864 | gimple *stmt = gsi_stmt (si); | |
3865 | unsigned uid = inc_gimple_stmt_max_uid (m_func); | |
3866 | gimple_set_uid (stmt, uid); | |
3867 | } | |
3868 | ||
3869 | return gimple_uid (inval_stmt) < gimple_uid (use_stmt); | |
3870 | } | |
3871 | ||
9d6a0f38 MS |
3872 | /* Issue a warning for the USE_STMT of pointer or reference REF rendered |
3873 | invalid by INVAL_STMT. REF may be null when it's been optimized away. | |
3874 | When nonnull, INVAL_STMT is the deallocation function that rendered | |
3875 | the pointer or reference dangling. Otherwise, VAR is the auto variable | |
3876 | (including an unnamed temporary such as a compound literal) whose | |
3877 | lifetime's rended it dangling. MAYBE is true to issue the "maybe" | |
3878 | kind of warning. EQUALITY is true when the pointer is used in | |
3879 | an equality expression. */ | |
671a2836 MS |
3880 | |
3881 | void | |
9d6a0f38 MS |
3882 | pass_waccess::warn_invalid_pointer (tree ref, gimple *use_stmt, |
3883 | gimple *inval_stmt, tree var, | |
3884 | bool maybe, bool equality /* = false */) | |
671a2836 MS |
3885 | { |
3886 | /* Avoid printing the unhelpful "<unknown>" in the diagnostics. */ | |
7bd1e129 MP |
3887 | if (ref && TREE_CODE (ref) == SSA_NAME) |
3888 | { | |
3889 | tree var = SSA_NAME_VAR (ref); | |
3890 | if (!var) | |
3891 | ref = NULL_TREE; | |
3892 | /* Don't warn for cases like when a cdtor returns 'this' on ARM. */ | |
3893 | else if (warning_suppressed_p (var, OPT_Wuse_after_free)) | |
3894 | return; | |
3895 | else if (DECL_ARTIFICIAL (var)) | |
3896 | ref = NULL_TREE; | |
3897 | } | |
671a2836 MS |
3898 | |
3899 | location_t use_loc = gimple_location (use_stmt); | |
3900 | if (use_loc == UNKNOWN_LOCATION) | |
3901 | { | |
9d6a0f38 MS |
3902 | use_loc = m_func->function_end_locus; |
3903 | if (!ref) | |
671a2836 MS |
3904 | /* Avoid issuing a warning with no context other than |
3905 | the function. That would make it difficult to debug | |
3906 | in any but very simple cases. */ | |
3907 | return; | |
3908 | } | |
3909 | ||
3910 | if (is_gimple_call (inval_stmt)) | |
3911 | { | |
3912 | if ((equality && warn_use_after_free < 3) | |
3913 | || (maybe && warn_use_after_free < 2) | |
3914 | || warning_suppressed_p (use_stmt, OPT_Wuse_after_free)) | |
3915 | return; | |
3916 | ||
3917 | const tree inval_decl = gimple_call_fndecl (inval_stmt); | |
3918 | ||
6ab98d8b | 3919 | auto_diagnostic_group d; |
9d6a0f38 | 3920 | if ((ref && warning_at (use_loc, OPT_Wuse_after_free, |
671a2836 MS |
3921 | (maybe |
3922 | ? G_("pointer %qE may be used after %qD") | |
3923 | : G_("pointer %qE used after %qD")), | |
9d6a0f38 MS |
3924 | ref, inval_decl)) |
3925 | || (!ref && warning_at (use_loc, OPT_Wuse_after_free, | |
671a2836 MS |
3926 | (maybe |
3927 | ? G_("pointer may be used after %qD") | |
3928 | : G_("pointer used after %qD")), | |
3929 | inval_decl))) | |
3930 | { | |
3931 | location_t loc = gimple_location (inval_stmt); | |
3932 | inform (loc, "call to %qD here", inval_decl); | |
3933 | suppress_warning (use_stmt, OPT_Wuse_after_free); | |
3934 | } | |
3935 | return; | |
3936 | } | |
9d6a0f38 | 3937 | |
9aaaae7e RB |
3938 | if (equality |
3939 | || (maybe && warn_dangling_pointer < 2) | |
9d6a0f38 MS |
3940 | || warning_suppressed_p (use_stmt, OPT_Wdangling_pointer_)) |
3941 | return; | |
3942 | ||
3943 | if (DECL_NAME (var)) | |
3944 | { | |
6ab98d8b | 3945 | auto_diagnostic_group d; |
9d6a0f38 MS |
3946 | if ((ref |
3947 | && warning_at (use_loc, OPT_Wdangling_pointer_, | |
3948 | (maybe | |
3949 | ? G_("dangling pointer %qE to %qD may be used") | |
3950 | : G_("using dangling pointer %qE to %qD")), | |
3951 | ref, var)) | |
3952 | || (!ref | |
3953 | && warning_at (use_loc, OPT_Wdangling_pointer_, | |
3954 | (maybe | |
3955 | ? G_("dangling pointer to %qD may be used") | |
3956 | : G_("using a dangling pointer to %qD")), | |
3957 | var))) | |
3958 | inform (DECL_SOURCE_LOCATION (var), | |
3959 | "%qD declared here", var); | |
3960 | suppress_warning (use_stmt, OPT_Wdangling_pointer_); | |
3961 | return; | |
3962 | } | |
3963 | ||
3964 | if ((ref | |
3965 | && warning_at (use_loc, OPT_Wdangling_pointer_, | |
3966 | (maybe | |
3967 | ? G_("dangling pointer %qE to an unnamed temporary " | |
3968 | "may be used") | |
3969 | : G_("using dangling pointer %qE to an unnamed " | |
3970 | "temporary")), | |
3e0b19f1 | 3971 | ref)) |
9d6a0f38 MS |
3972 | || (!ref |
3973 | && warning_at (use_loc, OPT_Wdangling_pointer_, | |
3974 | (maybe | |
3975 | ? G_("dangling pointer to an unnamed temporary " | |
3976 | "may be used") | |
3977 | : G_("using a dangling pointer to an unnamed " | |
3e0b19f1 | 3978 | "temporary"))))) |
9d6a0f38 MS |
3979 | { |
3980 | inform (DECL_SOURCE_LOCATION (var), | |
3981 | "unnamed temporary defined here"); | |
3982 | suppress_warning (use_stmt, OPT_Wdangling_pointer_); | |
3983 | } | |
671a2836 MS |
3984 | } |
3985 | ||
3986 | /* If STMT is a call to either the standard realloc or to a user-defined | |
3987 | reallocation function returns its LHS and set *PTR to the reallocated | |
3988 | pointer. Otherwise return null. */ | |
3989 | ||
3990 | static tree | |
3991 | get_realloc_lhs (gimple *stmt, tree *ptr) | |
3992 | { | |
3993 | if (gimple_call_builtin_p (stmt, BUILT_IN_REALLOC)) | |
3994 | { | |
3995 | *ptr = gimple_call_arg (stmt, 0); | |
3996 | return gimple_call_lhs (stmt); | |
3997 | } | |
3998 | ||
3999 | gcall *call = dyn_cast<gcall *>(stmt); | |
4000 | if (!call) | |
4001 | return NULL_TREE; | |
4002 | ||
4003 | tree fnattr = NULL_TREE; | |
4004 | tree fndecl = gimple_call_fndecl (call); | |
4005 | if (fndecl) | |
4006 | fnattr = DECL_ATTRIBUTES (fndecl); | |
4007 | else | |
4008 | { | |
4009 | tree fntype = gimple_call_fntype (stmt); | |
4010 | if (!fntype) | |
4011 | return NULL_TREE; | |
4012 | fnattr = TYPE_ATTRIBUTES (fntype); | |
4013 | } | |
4014 | ||
4015 | if (!fnattr) | |
4016 | return NULL_TREE; | |
4017 | ||
4018 | for (tree ats = fnattr; (ats = lookup_attribute ("*dealloc", ats)); | |
4019 | ats = TREE_CHAIN (ats)) | |
4020 | { | |
4021 | tree args = TREE_VALUE (ats); | |
4022 | if (!args) | |
4023 | continue; | |
4024 | ||
4025 | tree alloc = TREE_VALUE (args); | |
4026 | if (!alloc) | |
4027 | continue; | |
4028 | ||
4029 | if (alloc == DECL_NAME (fndecl)) | |
4030 | { | |
4031 | unsigned argno = 0; | |
4032 | if (tree index = TREE_CHAIN (args)) | |
4033 | argno = TREE_INT_CST_LOW (TREE_VALUE (index)) - 1; | |
4034 | *ptr = gimple_call_arg (stmt, argno); | |
4035 | return gimple_call_lhs (stmt); | |
4036 | } | |
4037 | } | |
4038 | ||
4039 | return NULL_TREE; | |
4040 | } | |
4041 | ||
4042 | /* Warn if STMT is a call to a deallocation function that's not a match | |
4043 | for the REALLOC_STMT call. Return true if warned. */ | |
4044 | ||
4045 | static bool | |
4046 | maybe_warn_mismatched_realloc (tree ptr, gimple *realloc_stmt, gimple *stmt) | |
4047 | { | |
4048 | if (!is_gimple_call (stmt)) | |
4049 | return false; | |
4050 | ||
4051 | tree fndecl = gimple_call_fndecl (stmt); | |
4052 | if (!fndecl) | |
4053 | return false; | |
4054 | ||
4055 | unsigned argno = fndecl_dealloc_argno (fndecl); | |
4056 | if (call_nargs (stmt) <= argno) | |
4057 | return false; | |
4058 | ||
4059 | if (matching_alloc_calls_p (realloc_stmt, fndecl)) | |
4060 | return false; | |
4061 | ||
4062 | /* Avoid printing the unhelpful "<unknown>" in the diagnostics. */ | |
4063 | if (ptr && TREE_CODE (ptr) == SSA_NAME | |
4064 | && (!SSA_NAME_VAR (ptr) || DECL_ARTIFICIAL (SSA_NAME_VAR (ptr)))) | |
4065 | ptr = NULL_TREE; | |
4066 | ||
4067 | location_t loc = gimple_location (stmt); | |
4068 | tree realloc_decl = gimple_call_fndecl (realloc_stmt); | |
4069 | tree dealloc_decl = gimple_call_fndecl (stmt); | |
4070 | if (ptr && !warning_at (loc, OPT_Wmismatched_dealloc, | |
4071 | "%qD called on pointer %qE passed to mismatched " | |
4072 | "allocation function %qD", | |
4073 | dealloc_decl, ptr, realloc_decl)) | |
4074 | return false; | |
4075 | if (!ptr && !warning_at (loc, OPT_Wmismatched_dealloc, | |
4076 | "%qD called on a pointer passed to mismatched " | |
4077 | "reallocation function %qD", | |
4078 | dealloc_decl, realloc_decl)) | |
4079 | return false; | |
4080 | ||
4081 | inform (gimple_location (realloc_stmt), | |
4082 | "call to %qD", realloc_decl); | |
4083 | return true; | |
4084 | } | |
4085 | ||
4086 | /* Return true if P and Q point to the same object, and false if they | |
4087 | either don't or their relationship cannot be determined. */ | |
4088 | ||
4089 | static bool | |
48d3191e MS |
4090 | pointers_related_p (gimple *stmt, tree p, tree q, pointer_query &qry, |
4091 | auto_bitmap &visited) | |
671a2836 MS |
4092 | { |
4093 | if (!ptr_derefs_may_alias_p (p, q)) | |
4094 | return false; | |
4095 | ||
4096 | /* TODO: Work harder to rule out relatedness. */ | |
4097 | access_ref pref, qref; | |
4098 | if (!qry.get_ref (p, stmt, &pref, 0) | |
4099 | || !qry.get_ref (q, stmt, &qref, 0)) | |
2f714642 MS |
4100 | /* GET_REF() only rarely fails. When it does, it's likely because |
4101 | it involves a self-referential PHI. Return a conservative result. */ | |
4102 | return false; | |
671a2836 | 4103 | |
48d3191e MS |
4104 | if (pref.ref == qref.ref) |
4105 | return true; | |
4106 | ||
4107 | /* If either pointer is a PHI, iterate over all its operands and | |
4108 | return true if they're all related to the other pointer. */ | |
4109 | tree ptr = q; | |
4110 | unsigned version; | |
4111 | gphi *phi = pref.phi (); | |
4112 | if (phi) | |
4113 | version = SSA_NAME_VERSION (pref.ref); | |
4114 | else | |
4115 | { | |
4116 | phi = qref.phi (); | |
4117 | if (!phi) | |
4118 | return false; | |
4119 | ||
4120 | ptr = p; | |
4121 | version = SSA_NAME_VERSION (qref.ref); | |
4122 | } | |
4123 | ||
4124 | if (!bitmap_set_bit (visited, version)) | |
4125 | return true; | |
4126 | ||
4127 | unsigned nargs = gimple_phi_num_args (phi); | |
4128 | for (unsigned i = 0; i != nargs; ++i) | |
4129 | { | |
4130 | tree arg = gimple_phi_arg_def (phi, i); | |
4131 | if (!pointers_related_p (stmt, arg, ptr, qry, visited)) | |
4132 | return false; | |
4133 | } | |
4134 | ||
4135 | return true; | |
4136 | } | |
4137 | ||
4138 | /* Convenience wrapper for the above. */ | |
4139 | ||
4140 | static bool | |
4141 | pointers_related_p (gimple *stmt, tree p, tree q, pointer_query &qry) | |
4142 | { | |
4143 | auto_bitmap visited; | |
4144 | return pointers_related_p (stmt, p, q, qry, visited); | |
671a2836 MS |
4145 | } |
4146 | ||
4147 | /* For a STMT either a call to a deallocation function or a clobber, warn | |
4148 | for uses of the pointer PTR it was called with (including its copies | |
9d6a0f38 MS |
4149 | or others derived from it by pointer arithmetic). If STMT is a clobber, |
4150 | VAR is the decl of the clobbered variable. When MAYBE is true use | |
4151 | a "maybe" form of diagnostic. */ | |
671a2836 MS |
4152 | |
4153 | void | |
9d6a0f38 MS |
4154 | pass_waccess::check_pointer_uses (gimple *stmt, tree ptr, |
4155 | tree var /* = NULL_TREE */, | |
4156 | bool maybe /* = false */) | |
671a2836 MS |
4157 | { |
4158 | gcc_assert (TREE_CODE (ptr) == SSA_NAME); | |
4159 | ||
4160 | const bool check_dangling = !is_gimple_call (stmt); | |
4161 | basic_block stmt_bb = gimple_bb (stmt); | |
4162 | ||
4163 | /* If STMT is a reallocation function set to the reallocated pointer | |
4164 | and the LHS of the call, respectively. */ | |
4165 | tree realloc_ptr = NULL_TREE; | |
4166 | tree realloc_lhs = get_realloc_lhs (stmt, &realloc_ptr); | |
4167 | ||
4168 | auto_bitmap visited; | |
4169 | ||
4170 | auto_vec<tree> pointers; | |
4171 | pointers.safe_push (ptr); | |
4172 | ||
4173 | /* Starting with PTR, iterate over POINTERS added by the loop, and | |
4174 | either warn for their uses in basic blocks dominated by the STMT | |
4175 | or in statements that follow it in the same basic block, or add | |
4176 | them to POINTERS if they point into the same object as PTR (i.e., | |
4177 | are obtained by pointer arithmetic on PTR). */ | |
4178 | for (unsigned i = 0; i != pointers.length (); ++i) | |
4179 | { | |
4180 | tree ptr = pointers[i]; | |
1a0e3bba | 4181 | if (!bitmap_set_bit (visited, SSA_NAME_VERSION (ptr))) |
671a2836 MS |
4182 | /* Avoid revisiting the same pointer. */ |
4183 | continue; | |
4184 | ||
4185 | use_operand_p use_p; | |
4186 | imm_use_iterator iter; | |
4187 | FOR_EACH_IMM_USE_FAST (use_p, iter, ptr) | |
4188 | { | |
4189 | gimple *use_stmt = USE_STMT (use_p); | |
4190 | if (use_stmt == stmt || is_gimple_debug (use_stmt)) | |
4191 | continue; | |
4192 | ||
4193 | if (realloc_lhs) | |
4194 | { | |
4195 | /* Check to see if USE_STMT is a mismatched deallocation | |
4196 | call for the pointer passed to realloc. That's a bug | |
4197 | regardless of the pointer's value and so warn. */ | |
4198 | if (maybe_warn_mismatched_realloc (*use_p->use, stmt, use_stmt)) | |
4199 | continue; | |
4200 | ||
4201 | /* Pointers passed to realloc that are used in basic blocks | |
4202 | where the realloc call is known to have failed are valid. | |
4203 | Ignore pointers that nothing is known about. Those could | |
4204 | have escaped along with their nullness. */ | |
4205 | value_range vr; | |
4206 | if (m_ptr_qry.rvals->range_of_expr (vr, realloc_lhs, use_stmt)) | |
4207 | { | |
4208 | if (vr.zero_p ()) | |
4209 | continue; | |
4210 | ||
4211 | if (!pointers_related_p (stmt, ptr, realloc_ptr, m_ptr_qry)) | |
4212 | continue; | |
4213 | } | |
4214 | } | |
4215 | ||
4216 | if (check_dangling | |
4217 | && gimple_code (use_stmt) == GIMPLE_RETURN) | |
4218 | /* Avoid interfering with -Wreturn-local-addr (which runs only | |
4219 | with optimization enabled so it won't diagnose cases that | |
4220 | would be caught here when optimization is disabled). */ | |
4221 | continue; | |
4222 | ||
4223 | bool equality = false; | |
4224 | if (is_gimple_assign (use_stmt)) | |
4225 | { | |
4226 | tree_code code = gimple_assign_rhs_code (use_stmt); | |
4227 | equality = code == EQ_EXPR || code == NE_EXPR; | |
4228 | } | |
4229 | else if (gcond *cond = dyn_cast<gcond *>(use_stmt)) | |
4230 | { | |
4231 | tree_code code = gimple_cond_code (cond); | |
4232 | equality = code == EQ_EXPR || code == NE_EXPR; | |
4233 | } | |
4234 | ||
4235 | /* Warn if USE_STMT is dominated by the deallocation STMT. | |
4236 | Otherwise, add the pointer to POINTERS so that the uses | |
4237 | of any other pointers derived from it can be checked. */ | |
9d6a0f38 | 4238 | if (use_after_inval_p (stmt, use_stmt, check_dangling)) |
671a2836 | 4239 | { |
9d6a0f38 | 4240 | if (gimple_code (use_stmt) == GIMPLE_PHI) |
671a2836 | 4241 | { |
48d3191e MS |
4242 | /* Only add a PHI result to POINTERS if all its |
4243 | operands are related to PTR, otherwise continue. */ | |
9d6a0f38 | 4244 | tree lhs = gimple_phi_result (use_stmt); |
48d3191e MS |
4245 | if (!pointers_related_p (stmt, lhs, ptr, m_ptr_qry)) |
4246 | continue; | |
4247 | ||
9d6a0f38 MS |
4248 | if (TREE_CODE (lhs) == SSA_NAME) |
4249 | { | |
4250 | pointers.safe_push (lhs); | |
4251 | continue; | |
4252 | } | |
671a2836 | 4253 | } |
9d6a0f38 MS |
4254 | |
4255 | basic_block use_bb = gimple_bb (use_stmt); | |
4256 | bool this_maybe | |
4257 | = (maybe | |
9aaaae7e | 4258 | || !dominated_by_p (CDI_POST_DOMINATORS, stmt_bb, use_bb)); |
9d6a0f38 MS |
4259 | warn_invalid_pointer (*use_p->use, use_stmt, stmt, var, |
4260 | this_maybe, equality); | |
4261 | continue; | |
671a2836 MS |
4262 | } |
4263 | ||
4264 | if (is_gimple_assign (use_stmt)) | |
4265 | { | |
4266 | tree lhs = gimple_assign_lhs (use_stmt); | |
4267 | if (TREE_CODE (lhs) == SSA_NAME) | |
4268 | { | |
4269 | tree_code rhs_code = gimple_assign_rhs_code (use_stmt); | |
4270 | if (rhs_code == POINTER_PLUS_EXPR || rhs_code == SSA_NAME) | |
4271 | pointers.safe_push (lhs); | |
4272 | } | |
4273 | continue; | |
4274 | } | |
4275 | ||
4276 | if (gcall *call = dyn_cast <gcall *>(use_stmt)) | |
4277 | { | |
1a0e3bba | 4278 | if (gimple_call_return_arg (call) == ptr) |
671a2836 MS |
4279 | if (tree lhs = gimple_call_lhs (call)) |
4280 | if (TREE_CODE (lhs) == SSA_NAME) | |
4281 | pointers.safe_push (lhs); | |
4282 | continue; | |
4283 | } | |
4284 | } | |
4285 | } | |
4286 | } | |
4287 | ||
2a837de2 MS |
4288 | /* Check call STMT for invalid accesses. */ |
4289 | ||
4290 | void | |
671a2836 | 4291 | pass_waccess::check_call (gcall *stmt) |
2a837de2 | 4292 | { |
c26d335f EB |
4293 | /* Skip special calls generated by the compiler. */ |
4294 | if (gimple_call_from_thunk_p (stmt)) | |
4295 | return; | |
81d6cdd3 | 4296 | |
53836c88 JJ |
4297 | /* .ASAN_MARK doesn't access any vars, only modifies shadow memory. */ |
4298 | if (gimple_call_internal_p (stmt) | |
4299 | && gimple_call_internal_fn (stmt) == IFN_ASAN_MARK) | |
4300 | return; | |
4301 | ||
c26d335f EB |
4302 | if (gimple_call_builtin_p (stmt, BUILT_IN_NORMAL)) |
4303 | check_builtin (stmt); | |
4304 | ||
9d6a0f38 MS |
4305 | if (!m_early_checks_p) |
4306 | if (tree callee = gimple_call_fndecl (stmt)) | |
4307 | { | |
4308 | /* Check for uses of the pointer passed to either a standard | |
4309 | or a user-defined deallocation function. */ | |
4310 | unsigned argno = fndecl_dealloc_argno (callee); | |
4311 | if (argno < (unsigned) call_nargs (stmt)) | |
4312 | { | |
4313 | tree arg = call_arg (stmt, argno); | |
4314 | if (TREE_CODE (arg) == SSA_NAME) | |
4315 | check_pointer_uses (stmt, arg); | |
4316 | } | |
4317 | } | |
b48d4e68 | 4318 | |
671a2836 | 4319 | check_call_access (stmt); |
9d6a0f38 MS |
4320 | check_call_dangling (stmt); |
4321 | ||
4322 | if (m_early_checks_p) | |
4323 | return; | |
b48d4e68 | 4324 | |
671a2836 | 4325 | maybe_check_dealloc_call (stmt); |
b48d4e68 | 4326 | check_nonstring_args (stmt); |
2a837de2 MS |
4327 | } |
4328 | ||
671a2836 | 4329 | |
9d6a0f38 MS |
4330 | /* Return true of X is a DECL with automatic storage duration. */ |
4331 | ||
4332 | static inline bool | |
4333 | is_auto_decl (tree x) | |
4334 | { | |
4335 | return DECL_P (x) && !DECL_EXTERNAL (x) && !TREE_STATIC (x); | |
4336 | } | |
4337 | ||
4338 | /* Check non-call STMT for invalid accesses. */ | |
4339 | ||
4340 | void | |
4341 | pass_waccess::check_stmt (gimple *stmt) | |
4342 | { | |
551aa757 RB |
4343 | if (m_check_dangling_p |
4344 | && gimple_clobber_p (stmt, CLOBBER_EOL)) | |
9d6a0f38 | 4345 | { |
4a1c20df | 4346 | /* Ignore clobber statements in blocks with exceptional edges. */ |
9d6a0f38 MS |
4347 | basic_block bb = gimple_bb (stmt); |
4348 | edge e = EDGE_PRED (bb, 0); | |
4349 | if (e->flags & EDGE_EH) | |
4350 | return; | |
4351 | ||
4352 | tree var = gimple_assign_lhs (stmt); | |
4353 | m_clobbers.put (var, stmt); | |
4354 | return; | |
4355 | } | |
4356 | ||
4357 | if (is_gimple_assign (stmt)) | |
4358 | { | |
4359 | /* Clobbered unnamed temporaries such as compound literals can be | |
4360 | revived. Check for an assignment to one and remove it from | |
4361 | M_CLOBBERS. */ | |
4362 | tree lhs = gimple_assign_lhs (stmt); | |
4363 | while (handled_component_p (lhs)) | |
4364 | lhs = TREE_OPERAND (lhs, 0); | |
4365 | ||
4366 | if (is_auto_decl (lhs)) | |
4367 | m_clobbers.remove (lhs); | |
4368 | return; | |
4369 | } | |
4370 | ||
4371 | if (greturn *ret = dyn_cast <greturn *> (stmt)) | |
4372 | { | |
4373 | if (optimize && flag_isolate_erroneous_paths_dereference) | |
4374 | /* Avoid interfering with -Wreturn-local-addr (which runs only | |
4375 | with optimization enabled). */ | |
4376 | return; | |
4377 | ||
4378 | tree arg = gimple_return_retval (ret); | |
4379 | if (!arg || TREE_CODE (arg) != ADDR_EXPR) | |
4380 | return; | |
4381 | ||
4382 | arg = TREE_OPERAND (arg, 0); | |
4383 | while (handled_component_p (arg)) | |
4384 | arg = TREE_OPERAND (arg, 0); | |
4385 | ||
4386 | if (!is_auto_decl (arg)) | |
4387 | return; | |
4388 | ||
4389 | gimple **pclobber = m_clobbers.get (arg); | |
4390 | if (!pclobber) | |
4391 | return; | |
4392 | ||
4393 | if (!use_after_inval_p (*pclobber, stmt)) | |
4394 | return; | |
4395 | ||
4396 | warn_invalid_pointer (NULL_TREE, stmt, *pclobber, arg, false); | |
4397 | } | |
4398 | } | |
4399 | ||
2a837de2 MS |
4400 | /* Check basic block BB for invalid accesses. */ |
4401 | ||
4402 | void | |
671a2836 | 4403 | pass_waccess::check_block (basic_block bb) |
2a837de2 MS |
4404 | { |
4405 | /* Iterate over statements, looking for function calls. */ | |
671a2836 MS |
4406 | for (auto si = gsi_start_bb (bb); !gsi_end_p (si); |
4407 | gsi_next_nondebug (&si)) | |
2a837de2 | 4408 | { |
671a2836 MS |
4409 | gimple *stmt = gsi_stmt (si); |
4410 | if (gcall *call = dyn_cast <gcall *> (stmt)) | |
4411 | check_call (call); | |
9d6a0f38 MS |
4412 | else |
4413 | check_stmt (stmt); | |
2a837de2 MS |
4414 | } |
4415 | } | |
4416 | ||
671a2836 MS |
4417 | /* Return the argument that the call STMT to a built-in function returns |
4418 | (including with an offset) or null if it doesn't. */ | |
4419 | ||
4420 | tree | |
4421 | pass_waccess::gimple_call_return_arg (gcall *call) | |
4422 | { | |
4423 | /* Check for attribute fn spec to see if the function returns one | |
4424 | of its arguments. */ | |
4425 | attr_fnspec fnspec = gimple_call_fnspec (call); | |
4426 | unsigned int argno; | |
4427 | if (!fnspec.returns_arg (&argno)) | |
4428 | { | |
4429 | if (gimple_call_num_args (call) < 1) | |
4430 | return NULL_TREE; | |
4431 | ||
4432 | if (!gimple_call_builtin_p (call, BUILT_IN_NORMAL)) | |
4433 | return NULL_TREE; | |
4434 | ||
4435 | tree fndecl = gimple_call_fndecl (call); | |
4436 | switch (DECL_FUNCTION_CODE (fndecl)) | |
4437 | { | |
4438 | case BUILT_IN_MEMPCPY: | |
4439 | case BUILT_IN_MEMPCPY_CHK: | |
4440 | case BUILT_IN_MEMCHR: | |
4441 | case BUILT_IN_STRCHR: | |
4442 | case BUILT_IN_STRRCHR: | |
4443 | case BUILT_IN_STRSTR: | |
4444 | case BUILT_IN_STPCPY: | |
4445 | case BUILT_IN_STPCPY_CHK: | |
4446 | case BUILT_IN_STPNCPY: | |
4447 | case BUILT_IN_STPNCPY_CHK: | |
4448 | argno = 0; | |
4449 | break; | |
4450 | ||
4451 | default: | |
4452 | return NULL_TREE; | |
4453 | } | |
4454 | } | |
4455 | ||
4456 | if (gimple_call_num_args (call) <= argno) | |
4457 | return NULL_TREE; | |
4458 | ||
4459 | return gimple_call_arg (call, argno); | |
4460 | } | |
4461 | ||
9d6a0f38 MS |
4462 | /* Check for and diagnose all uses of the dangling pointer VAR to the auto |
4463 | object DECL whose lifetime has ended. OBJREF is true when VAR denotes | |
4464 | an access to a DECL that may have been clobbered. */ | |
4465 | ||
4466 | void | |
4467 | pass_waccess::check_dangling_uses (tree var, tree decl, bool maybe /* = false */, | |
4468 | bool objref /* = false */) | |
4469 | { | |
4470 | if (!decl || !is_auto_decl (decl)) | |
4471 | return; | |
4472 | ||
4473 | gimple **pclob = m_clobbers.get (decl); | |
4474 | if (!pclob) | |
4475 | return; | |
4476 | ||
4477 | if (!objref) | |
4478 | { | |
4479 | check_pointer_uses (*pclob, var, decl, maybe); | |
4480 | return; | |
4481 | } | |
4482 | ||
4483 | gimple *use_stmt = SSA_NAME_DEF_STMT (var); | |
4484 | if (!use_after_inval_p (*pclob, use_stmt, true)) | |
4485 | return; | |
4486 | ||
4487 | basic_block use_bb = gimple_bb (use_stmt); | |
4488 | basic_block clob_bb = gimple_bb (*pclob); | |
9aaaae7e | 4489 | maybe = maybe || !dominated_by_p (CDI_POST_DOMINATORS, clob_bb, use_bb); |
9d6a0f38 MS |
4490 | warn_invalid_pointer (var, use_stmt, *pclob, decl, maybe, false); |
4491 | } | |
4492 | ||
4493 | /* Diagnose stores in BB and (recursively) its predecessors of the addresses | |
4494 | of local variables into nonlocal pointers that are left dangling after | |
4495 | the function returns. BBS is a bitmap of basic blocks visited. */ | |
4496 | ||
4497 | void | |
4498 | pass_waccess::check_dangling_stores (basic_block bb, | |
4499 | hash_set<tree> &stores, | |
4500 | auto_bitmap &bbs) | |
4501 | { | |
4502 | if (!bitmap_set_bit (bbs, bb->index)) | |
4503 | /* Avoid cycles. */ | |
4504 | return; | |
4505 | ||
4506 | /* Iterate backwards over the statements looking for a store of | |
4507 | the address of a local variable into a nonlocal pointer. */ | |
4508 | for (auto gsi = gsi_last_nondebug_bb (bb); ; gsi_prev_nondebug (&gsi)) | |
4509 | { | |
4510 | gimple *stmt = gsi_stmt (gsi); | |
4511 | if (!stmt) | |
4512 | break; | |
4513 | ||
373a2dc2 MS |
4514 | if (warning_suppressed_p (stmt, OPT_Wdangling_pointer_)) |
4515 | continue; | |
4516 | ||
9d6a0f38 MS |
4517 | if (is_gimple_call (stmt) |
4518 | && !(gimple_call_flags (stmt) & (ECF_CONST | ECF_PURE))) | |
4519 | /* Avoid looking before nonconst, nonpure calls since those might | |
4520 | use the escaped locals. */ | |
4521 | return; | |
4522 | ||
4523 | if (!is_gimple_assign (stmt) || gimple_clobber_p (stmt)) | |
4524 | continue; | |
4525 | ||
4526 | access_ref lhs_ref; | |
4527 | tree lhs = gimple_assign_lhs (stmt); | |
4528 | if (!m_ptr_qry.get_ref (lhs, stmt, &lhs_ref, 0)) | |
4529 | continue; | |
4530 | ||
4531 | if (is_auto_decl (lhs_ref.ref)) | |
4532 | continue; | |
4533 | ||
4534 | if (DECL_P (lhs_ref.ref)) | |
4535 | { | |
4536 | if (!POINTER_TYPE_P (TREE_TYPE (lhs_ref.ref)) | |
4537 | || lhs_ref.deref > 0) | |
4538 | continue; | |
4539 | } | |
4540 | else if (TREE_CODE (lhs_ref.ref) == SSA_NAME) | |
4541 | { | |
9d6a0f38 MS |
4542 | gimple *def_stmt = SSA_NAME_DEF_STMT (lhs_ref.ref); |
4543 | if (!gimple_nop_p (def_stmt)) | |
373a2dc2 | 4544 | /* Avoid looking at or before stores into unknown objects. */ |
9d6a0f38 | 4545 | return; |
373a2dc2 MS |
4546 | |
4547 | tree var = SSA_NAME_VAR (lhs_ref.ref); | |
4548 | if (TREE_CODE (var) == PARM_DECL && DECL_BY_REFERENCE (var)) | |
4549 | /* Avoid by-value arguments transformed into by-reference. */ | |
4550 | continue; | |
4551 | ||
9d6a0f38 MS |
4552 | } |
4553 | else if (TREE_CODE (lhs_ref.ref) == MEM_REF) | |
4554 | { | |
4555 | tree arg = TREE_OPERAND (lhs_ref.ref, 0); | |
4556 | if (TREE_CODE (arg) == SSA_NAME) | |
4557 | { | |
4558 | gimple *def_stmt = SSA_NAME_DEF_STMT (arg); | |
4559 | if (!gimple_nop_p (def_stmt)) | |
4560 | return; | |
4561 | } | |
4562 | } | |
4563 | else | |
4564 | continue; | |
4565 | ||
4566 | if (stores.add (lhs_ref.ref)) | |
4567 | continue; | |
4568 | ||
4569 | /* FIXME: Handle stores of alloca() and VLA. */ | |
4570 | access_ref rhs_ref; | |
4571 | tree rhs = gimple_assign_rhs1 (stmt); | |
4572 | if (!m_ptr_qry.get_ref (rhs, stmt, &rhs_ref, 0) | |
4573 | || rhs_ref.deref != -1) | |
4574 | continue; | |
4575 | ||
4576 | if (!is_auto_decl (rhs_ref.ref)) | |
4577 | continue; | |
4578 | ||
6ab98d8b | 4579 | auto_diagnostic_group d; |
9d6a0f38 MS |
4580 | location_t loc = gimple_location (stmt); |
4581 | if (warning_at (loc, OPT_Wdangling_pointer_, | |
4582 | "storing the address of local variable %qD in %qE", | |
4583 | rhs_ref.ref, lhs)) | |
4584 | { | |
373a2dc2 MS |
4585 | suppress_warning (stmt, OPT_Wdangling_pointer_); |
4586 | ||
9d6a0f38 MS |
4587 | location_t loc = DECL_SOURCE_LOCATION (rhs_ref.ref); |
4588 | inform (loc, "%qD declared here", rhs_ref.ref); | |
4589 | ||
4590 | if (DECL_P (lhs_ref.ref)) | |
4591 | loc = DECL_SOURCE_LOCATION (lhs_ref.ref); | |
4592 | else if (EXPR_HAS_LOCATION (lhs_ref.ref)) | |
4593 | loc = EXPR_LOCATION (lhs_ref.ref); | |
4594 | ||
4595 | if (loc != UNKNOWN_LOCATION) | |
4596 | inform (loc, "%qE declared here", lhs_ref.ref); | |
4597 | } | |
4598 | } | |
4599 | ||
4600 | edge e; | |
4601 | edge_iterator ei; | |
4602 | FOR_EACH_EDGE (e, ei, bb->preds) | |
4603 | { | |
4604 | basic_block pred = e->src; | |
4605 | check_dangling_stores (pred, stores, bbs); | |
4606 | } | |
4607 | } | |
4608 | ||
4609 | /* Diagnose stores of the addresses of local variables into nonlocal | |
4610 | pointers that are left dangling after the function returns. */ | |
4611 | ||
4612 | void | |
4613 | pass_waccess::check_dangling_stores () | |
4614 | { | |
4615 | auto_bitmap bbs; | |
4616 | hash_set<tree> stores; | |
4617 | check_dangling_stores (EXIT_BLOCK_PTR_FOR_FN (m_func), stores, bbs); | |
4618 | } | |
4619 | ||
4620 | /* Check for and diagnose uses of dangling pointers to auto objects | |
4621 | whose lifetime has ended. */ | |
4622 | ||
4623 | void | |
4624 | pass_waccess::check_dangling_uses () | |
4625 | { | |
4626 | tree var; | |
4627 | unsigned i; | |
4628 | FOR_EACH_SSA_NAME (i, var, m_func) | |
4629 | { | |
d492d50f RB |
4630 | /* For each SSA_NAME pointer VAR find the object it points to. |
4631 | If the object is a clobbered local variable, check to see | |
9d6a0f38 MS |
4632 | if any of VAR's uses (or those of other pointers derived |
4633 | from VAR) happens after the clobber. If so, warn. */ | |
9d6a0f38 MS |
4634 | |
4635 | gimple *def_stmt = SSA_NAME_DEF_STMT (var); | |
4636 | if (is_gimple_assign (def_stmt)) | |
4637 | { | |
4638 | tree rhs = gimple_assign_rhs1 (def_stmt); | |
4639 | if (TREE_CODE (rhs) == ADDR_EXPR) | |
4640 | { | |
4641 | if (!POINTER_TYPE_P (TREE_TYPE (var))) | |
4642 | continue; | |
d492d50f | 4643 | check_dangling_uses (var, TREE_OPERAND (rhs, 0)); |
9d6a0f38 MS |
4644 | } |
4645 | else | |
4646 | { | |
4647 | /* For other expressions, check the base DECL to see | |
4648 | if it's been clobbered, most likely as a result of | |
4649 | inlining a reference to it. */ | |
d492d50f | 4650 | tree decl = get_base_address (rhs); |
9d6a0f38 MS |
4651 | if (DECL_P (decl)) |
4652 | check_dangling_uses (var, decl, false, true); | |
9d6a0f38 MS |
4653 | } |
4654 | } | |
4655 | else if (POINTER_TYPE_P (TREE_TYPE (var))) | |
4656 | { | |
4657 | if (gcall *call = dyn_cast<gcall *>(def_stmt)) | |
d492d50f RB |
4658 | { |
4659 | if (tree arg = gimple_call_return_arg (call)) | |
4660 | { | |
4661 | access_ref aref; | |
4662 | if (m_ptr_qry.get_ref (arg, call, &aref, 0) | |
4663 | && aref.deref < 0) | |
4664 | check_dangling_uses (var, aref.ref); | |
4665 | } | |
4666 | } | |
9d6a0f38 MS |
4667 | else if (gphi *phi = dyn_cast <gphi *>(def_stmt)) |
4668 | { | |
4669 | unsigned nargs = gimple_phi_num_args (phi); | |
4670 | for (unsigned i = 0; i != nargs; ++i) | |
4671 | { | |
4672 | access_ref aref; | |
4673 | tree arg = gimple_phi_arg_def (phi, i); | |
d492d50f RB |
4674 | if (m_ptr_qry.get_ref (arg, phi, &aref, 0) |
4675 | && aref.deref < 0) | |
4676 | check_dangling_uses (var, aref.ref, true); | |
9d6a0f38 | 4677 | } |
9d6a0f38 | 4678 | } |
9d6a0f38 | 4679 | } |
9d6a0f38 MS |
4680 | } |
4681 | } | |
4682 | ||
4683 | /* Check CALL arguments for dangling pointers (those that have been | |
4684 | clobbered) and warn if found. */ | |
4685 | ||
4686 | void | |
4687 | pass_waccess::check_call_dangling (gcall *call) | |
4688 | { | |
4689 | unsigned nargs = gimple_call_num_args (call); | |
4690 | for (unsigned i = 0; i != nargs; ++i) | |
4691 | { | |
4692 | tree arg = gimple_call_arg (call, i); | |
4693 | if (TREE_CODE (arg) != ADDR_EXPR) | |
4694 | continue; | |
4695 | ||
4696 | arg = TREE_OPERAND (arg, 0); | |
4697 | if (!DECL_P (arg)) | |
4698 | continue; | |
4699 | ||
4700 | gimple **pclobber = m_clobbers.get (arg); | |
4701 | if (!pclobber) | |
4702 | continue; | |
4703 | ||
4704 | if (!use_after_inval_p (*pclobber, call)) | |
4705 | continue; | |
4706 | ||
4707 | warn_invalid_pointer (NULL_TREE, call, *pclobber, arg, false); | |
4708 | } | |
4709 | } | |
4710 | ||
2a837de2 MS |
4711 | /* Check function FUN for invalid accesses. */ |
4712 | ||
4713 | unsigned | |
4714 | pass_waccess::execute (function *fun) | |
4715 | { | |
671a2836 MS |
4716 | calculate_dominance_info (CDI_DOMINATORS); |
4717 | calculate_dominance_info (CDI_POST_DOMINATORS); | |
4718 | ||
51149a05 MS |
4719 | /* Set or clear EDGE_DFS_BACK bits on back edges. */ |
4720 | mark_dfs_back_edges (fun); | |
4721 | ||
81501087 | 4722 | /* Create a new ranger instance and associate it with FUN. */ |
ece28da9 | 4723 | m_ptr_qry.rvals = enable_ranger (fun); |
671a2836 MS |
4724 | m_func = fun; |
4725 | ||
9d6a0f38 MS |
4726 | /* Check for dangling pointers in the earliest run of the pass. |
4727 | The latest point -Wdangling-pointer should run is just before | |
4728 | loop unrolling which introduces uses after clobbers. Most cases | |
4729 | can be detected without optimization; cases where the address of | |
4730 | the local variable is passed to and then returned from a user- | |
4731 | defined function before its lifetime ends and the returned pointer | |
4732 | becomes dangling depend on inlining. */ | |
4733 | m_check_dangling_p = m_early_checks_p; | |
4734 | ||
671a2836 MS |
4735 | auto_bitmap bb_uids_set (&bitmap_default_obstack); |
4736 | m_bb_uids_set = bb_uids_set; | |
4737 | ||
4738 | set_gimple_stmt_max_uid (m_func, 0); | |
b48d4e68 | 4739 | |
2a837de2 MS |
4740 | basic_block bb; |
4741 | FOR_EACH_BB_FN (bb, fun) | |
671a2836 | 4742 | check_block (bb); |
2a837de2 | 4743 | |
9d6a0f38 MS |
4744 | if (m_check_dangling_p) |
4745 | { | |
4746 | check_dangling_uses (); | |
4747 | check_dangling_stores (); | |
4748 | } | |
4749 | ||
ece28da9 MS |
4750 | if (dump_file) |
4751 | m_ptr_qry.dump (dump_file, (dump_flags & TDF_DETAILS) != 0); | |
4752 | ||
4753 | m_ptr_qry.flush_cache (); | |
4754 | ||
4755 | /* Release the ranger instance and replace it with a global ranger. | |
4756 | Also reset the pointer since calling disable_ranger() deletes it. */ | |
81501087 | 4757 | disable_ranger (fun); |
ece28da9 | 4758 | m_ptr_qry.rvals = NULL; |
81501087 | 4759 | |
9d6a0f38 | 4760 | m_clobbers.empty (); |
671a2836 MS |
4761 | m_bb_uids_set = NULL; |
4762 | ||
4763 | free_dominance_info (CDI_POST_DOMINATORS); | |
4764 | free_dominance_info (CDI_DOMINATORS); | |
2a837de2 MS |
4765 | return 0; |
4766 | } | |
4767 | ||
4768 | } // namespace | |
4769 | ||
4770 | /* Return a new instance of the pass. */ | |
4771 | ||
4772 | gimple_opt_pass * | |
4773 | make_pass_warn_access (gcc::context *ctxt) | |
4774 | { | |
4775 | return new pass_waccess (ctxt); | |
4776 | } |