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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 | ||
4 | Copyright (C) 2020-2021 Free Software Foundation, Inc. | |
5 | Contributed by Martin Sebor <msebor@redhat.com>. | |
6 | ||
7 | This file is part of GCC. | |
8 | ||
9 | GCC is free software; you can redistribute it and/or modify it under | |
10 | the terms of the GNU General Public License as published by the Free | |
11 | Software Foundation; either version 3, or (at your option) any later | |
12 | version. | |
13 | ||
14 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
15 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
16 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
17 | for more details. | |
18 | ||
19 | You should have received a copy of the GNU General Public License | |
20 | along with GCC; see the file COPYING3. If not see | |
21 | <http://www.gnu.org/licenses/>. */ | |
22 | ||
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" | |
32 | #include "ssa.h" | |
33 | #include "gimple-pretty-print.h" | |
34 | #include "gimple-ssa-warn-access.h" | |
35 | #include "gimple-ssa-warn-restrict.h" | |
36 | #include "diagnostic-core.h" | |
37 | #include "fold-const.h" | |
38 | #include "gimple-fold.h" | |
39 | #include "gimple-iterator.h" | |
b48d4e68 | 40 | #include "langhooks.h" |
2a837de2 MS |
41 | #include "tree-dfa.h" |
42 | #include "tree-ssa.h" | |
43 | #include "tree-cfg.h" | |
44 | #include "tree-object-size.h" | |
81d6cdd3 | 45 | #include "tree-ssa-strlen.h" |
2a837de2 MS |
46 | #include "calls.h" |
47 | #include "cfgloop.h" | |
48 | #include "intl.h" | |
49 | #include "gimple-range.h" | |
50 | #include "stringpool.h" | |
51 | #include "attribs.h" | |
52 | #include "demangle.h" | |
53 | #include "pointer-query.h" | |
54 | ||
81d6cdd3 MS |
55 | /* Return true if tree node X has an associated location. */ |
56 | ||
57 | static inline location_t | |
58 | has_location (const_tree x) | |
59 | { | |
60 | if (DECL_P (x)) | |
61 | return DECL_SOURCE_LOCATION (x) != UNKNOWN_LOCATION; | |
62 | ||
63 | if (EXPR_P (x)) | |
64 | return EXPR_HAS_LOCATION (x); | |
65 | ||
66 | return false; | |
67 | } | |
68 | ||
69 | /* Return the associated location of STMT. */ | |
70 | ||
71 | static inline location_t | |
72 | get_location (const gimple *stmt) | |
73 | { | |
74 | return gimple_location (stmt); | |
75 | } | |
76 | ||
77 | /* Return the associated location of tree node X. */ | |
78 | ||
79 | static inline location_t | |
80 | get_location (tree x) | |
81 | { | |
82 | if (DECL_P (x)) | |
83 | return DECL_SOURCE_LOCATION (x); | |
84 | ||
85 | if (EXPR_P (x)) | |
86 | return EXPR_LOCATION (x); | |
87 | ||
88 | return UNKNOWN_LOCATION; | |
89 | } | |
90 | ||
91 | /* Overload of the nascent tree function for GIMPLE STMT. */ | |
92 | ||
93 | static inline tree | |
94 | get_callee_fndecl (const gimple *stmt) | |
95 | { | |
96 | return gimple_call_fndecl (stmt); | |
97 | } | |
98 | ||
99 | static inline unsigned | |
100 | call_nargs (const gimple *stmt) | |
101 | { | |
102 | return gimple_call_num_args (stmt); | |
103 | } | |
104 | ||
105 | static inline unsigned | |
106 | call_nargs (const_tree expr) | |
107 | { | |
108 | return call_expr_nargs (expr); | |
109 | } | |
110 | ||
111 | ||
112 | static inline tree | |
113 | call_arg (const gimple *stmt, unsigned argno) | |
114 | { | |
115 | return gimple_call_arg (stmt, argno); | |
116 | } | |
117 | ||
118 | static inline tree | |
119 | call_arg (tree expr, unsigned argno) | |
120 | { | |
121 | return CALL_EXPR_ARG (expr, argno); | |
122 | } | |
123 | ||
2a837de2 MS |
124 | /* For a call EXPR at LOC to a function FNAME that expects a string |
125 | in the argument ARG, issue a diagnostic due to it being a called | |
126 | with an argument that is a character array with no terminating | |
127 | NUL. SIZE is the EXACT size of the array, and BNDRNG the number | |
128 | of characters in which the NUL is expected. Either EXPR or FNAME | |
129 | may be null but noth both. SIZE may be null when BNDRNG is null. */ | |
130 | ||
81d6cdd3 MS |
131 | template <class GimpleOrTree> |
132 | static void | |
133 | warn_string_no_nul (location_t loc, GimpleOrTree expr, const char *fname, | |
134 | tree arg, tree decl, tree size, bool exact, | |
2a837de2 MS |
135 | const wide_int bndrng[2] /* = NULL */) |
136 | { | |
137 | const opt_code opt = OPT_Wstringop_overread; | |
138 | if ((expr && warning_suppressed_p (expr, opt)) | |
139 | || warning_suppressed_p (arg, opt)) | |
140 | return; | |
141 | ||
142 | loc = expansion_point_location_if_in_system_header (loc); | |
143 | bool warned; | |
144 | ||
145 | /* Format the bound range as a string to keep the nuber of messages | |
146 | from exploding. */ | |
147 | char bndstr[80]; | |
148 | *bndstr = 0; | |
149 | if (bndrng) | |
150 | { | |
151 | if (bndrng[0] == bndrng[1]) | |
152 | sprintf (bndstr, "%llu", (unsigned long long) bndrng[0].to_uhwi ()); | |
153 | else | |
154 | sprintf (bndstr, "[%llu, %llu]", | |
155 | (unsigned long long) bndrng[0].to_uhwi (), | |
156 | (unsigned long long) bndrng[1].to_uhwi ()); | |
157 | } | |
158 | ||
159 | const tree maxobjsize = max_object_size (); | |
160 | const wide_int maxsiz = wi::to_wide (maxobjsize); | |
161 | if (expr) | |
162 | { | |
163 | tree func = get_callee_fndecl (expr); | |
164 | if (bndrng) | |
165 | { | |
166 | if (wi::ltu_p (maxsiz, bndrng[0])) | |
167 | warned = warning_at (loc, opt, | |
168 | "%qD specified bound %s exceeds " | |
169 | "maximum object size %E", | |
170 | func, bndstr, maxobjsize); | |
171 | else | |
172 | { | |
173 | bool maybe = wi::to_wide (size) == bndrng[0]; | |
174 | warned = warning_at (loc, opt, | |
175 | exact | |
176 | ? G_("%qD specified bound %s exceeds " | |
177 | "the size %E of unterminated array") | |
178 | : (maybe | |
179 | ? G_("%qD specified bound %s may " | |
180 | "exceed the size of at most %E " | |
181 | "of unterminated array") | |
182 | : G_("%qD specified bound %s exceeds " | |
183 | "the size of at most %E " | |
184 | "of unterminated array")), | |
185 | func, bndstr, size); | |
186 | } | |
187 | } | |
188 | else | |
189 | warned = warning_at (loc, opt, | |
190 | "%qD argument missing terminating nul", | |
191 | func); | |
192 | } | |
193 | else | |
194 | { | |
195 | if (bndrng) | |
196 | { | |
197 | if (wi::ltu_p (maxsiz, bndrng[0])) | |
198 | warned = warning_at (loc, opt, | |
199 | "%qs specified bound %s exceeds " | |
200 | "maximum object size %E", | |
201 | fname, bndstr, maxobjsize); | |
202 | else | |
203 | { | |
204 | bool maybe = wi::to_wide (size) == bndrng[0]; | |
205 | warned = warning_at (loc, opt, | |
206 | exact | |
207 | ? G_("%qs specified bound %s exceeds " | |
208 | "the size %E of unterminated array") | |
209 | : (maybe | |
210 | ? G_("%qs specified bound %s may " | |
211 | "exceed the size of at most %E " | |
212 | "of unterminated array") | |
213 | : G_("%qs specified bound %s exceeds " | |
214 | "the size of at most %E " | |
215 | "of unterminated array")), | |
216 | fname, bndstr, size); | |
217 | } | |
218 | } | |
219 | else | |
220 | warned = warning_at (loc, opt, | |
221 | "%qs argument missing terminating nul", | |
222 | fname); | |
223 | } | |
224 | ||
225 | if (warned) | |
226 | { | |
81d6cdd3 | 227 | inform (get_location (decl), |
2a837de2 MS |
228 | "referenced argument declared here"); |
229 | suppress_warning (arg, opt); | |
230 | if (expr) | |
231 | suppress_warning (expr, opt); | |
232 | } | |
233 | } | |
234 | ||
81d6cdd3 MS |
235 | void |
236 | warn_string_no_nul (location_t loc, gimple *stmt, const char *fname, | |
237 | tree arg, tree decl, tree size /* = NULL_TREE */, | |
238 | bool exact /* = false */, | |
239 | const wide_int bndrng[2] /* = NULL */) | |
240 | { | |
241 | return warn_string_no_nul<gimple *> (loc, stmt, fname, | |
242 | arg, decl, size, exact, bndrng); | |
243 | } | |
244 | ||
245 | void | |
246 | warn_string_no_nul (location_t loc, tree expr, const char *fname, | |
247 | tree arg, tree decl, tree size /* = NULL_TREE */, | |
248 | bool exact /* = false */, | |
249 | const wide_int bndrng[2] /* = NULL */) | |
250 | { | |
251 | return warn_string_no_nul<tree> (loc, expr, fname, | |
252 | arg, decl, size, exact, bndrng); | |
253 | } | |
254 | ||
255 | /* If EXP refers to an unterminated constant character array return | |
256 | the declaration of the object of which the array is a member or | |
257 | element and if SIZE is not null, set *SIZE to the size of | |
258 | the unterminated array and set *EXACT if the size is exact or | |
259 | clear it otherwise. Otherwise return null. */ | |
260 | ||
261 | tree | |
262 | unterminated_array (tree exp, tree *size /* = NULL */, bool *exact /* = NULL */) | |
263 | { | |
264 | /* C_STRLEN will return NULL and set DECL in the info | |
265 | structure if EXP references a unterminated array. */ | |
266 | c_strlen_data lendata = { }; | |
267 | tree len = c_strlen (exp, 1, &lendata); | |
268 | if (len || !lendata.minlen || !lendata.decl) | |
269 | return NULL_TREE; | |
270 | ||
271 | if (!size) | |
272 | return lendata.decl; | |
273 | ||
274 | len = lendata.minlen; | |
275 | if (lendata.off) | |
276 | { | |
277 | /* Constant offsets are already accounted for in LENDATA.MINLEN, | |
278 | but not in a SSA_NAME + CST expression. */ | |
279 | if (TREE_CODE (lendata.off) == INTEGER_CST) | |
280 | *exact = true; | |
281 | else if (TREE_CODE (lendata.off) == PLUS_EXPR | |
282 | && TREE_CODE (TREE_OPERAND (lendata.off, 1)) == INTEGER_CST) | |
283 | { | |
284 | /* Subtract the offset from the size of the array. */ | |
285 | *exact = false; | |
286 | tree temp = TREE_OPERAND (lendata.off, 1); | |
287 | temp = fold_convert (ssizetype, temp); | |
288 | len = fold_build2 (MINUS_EXPR, ssizetype, len, temp); | |
289 | } | |
290 | else | |
291 | *exact = false; | |
292 | } | |
293 | else | |
294 | *exact = true; | |
295 | ||
296 | *size = len; | |
297 | return lendata.decl; | |
298 | } | |
299 | ||
2a837de2 MS |
300 | /* For a call EXPR (which may be null) that expects a string argument |
301 | SRC as an argument, returns false if SRC is a character array with | |
302 | no terminating NUL. When nonnull, BOUND is the number of characters | |
81d6cdd3 MS |
303 | in which to expect the terminating NUL. When EXPR is nonnull also |
304 | issues a warning. */ | |
2a837de2 | 305 | |
81d6cdd3 MS |
306 | template <class GimpleOrTree> |
307 | static bool | |
308 | check_nul_terminated_array (GimpleOrTree expr, tree src, tree bound) | |
2a837de2 MS |
309 | { |
310 | /* The constant size of the array SRC points to. The actual size | |
311 | may be less of EXACT is true, but not more. */ | |
312 | tree size; | |
313 | /* True if SRC involves a non-constant offset into the array. */ | |
314 | bool exact; | |
315 | /* The unterminated constant array SRC points to. */ | |
316 | tree nonstr = unterminated_array (src, &size, &exact); | |
317 | if (!nonstr) | |
318 | return true; | |
319 | ||
320 | /* NONSTR refers to the non-nul terminated constant array and SIZE | |
321 | is the constant size of the array in bytes. EXACT is true when | |
322 | SIZE is exact. */ | |
323 | ||
324 | wide_int bndrng[2]; | |
325 | if (bound) | |
326 | { | |
327 | value_range r; | |
328 | ||
329 | get_global_range_query ()->range_of_expr (r, bound); | |
330 | ||
331 | if (r.kind () != VR_RANGE) | |
332 | return true; | |
333 | ||
334 | bndrng[0] = r.lower_bound (); | |
335 | bndrng[1] = r.upper_bound (); | |
336 | ||
337 | if (exact) | |
338 | { | |
339 | if (wi::leu_p (bndrng[0], wi::to_wide (size))) | |
340 | return true; | |
341 | } | |
342 | else if (wi::lt_p (bndrng[0], wi::to_wide (size), UNSIGNED)) | |
343 | return true; | |
344 | } | |
345 | ||
346 | if (expr) | |
81d6cdd3 | 347 | warn_string_no_nul (get_location (expr), expr, NULL, src, nonstr, |
2a837de2 MS |
348 | size, exact, bound ? bndrng : NULL); |
349 | ||
350 | return false; | |
351 | } | |
352 | ||
81d6cdd3 MS |
353 | bool |
354 | check_nul_terminated_array (gimple *stmt, tree src, tree bound /* = NULL_TREE */) | |
355 | { | |
356 | return check_nul_terminated_array<gimple *>(stmt, src, bound); | |
357 | } | |
2a837de2 | 358 | |
81d6cdd3 MS |
359 | bool |
360 | check_nul_terminated_array (tree expr, tree src, tree bound /* = NULL_TREE */) | |
2a837de2 | 361 | { |
81d6cdd3 MS |
362 | return check_nul_terminated_array<tree>(expr, src, bound); |
363 | } | |
364 | ||
365 | /* Warn about passing a non-string array/pointer to a built-in function | |
366 | that expects a nul-terminated string argument. Returns true if | |
367 | a warning has been issued.*/ | |
368 | ||
369 | template <class GimpleOrTree> | |
370 | static bool | |
371 | maybe_warn_nonstring_arg (tree fndecl, GimpleOrTree exp) | |
372 | { | |
373 | if (!fndecl || !fndecl_built_in_p (fndecl, BUILT_IN_NORMAL)) | |
374 | return false; | |
375 | ||
376 | if (!warn_stringop_overread | |
377 | || warning_suppressed_p (exp, OPT_Wstringop_overread)) | |
378 | return false; | |
379 | ||
380 | /* Avoid clearly invalid calls (more checking done below). */ | |
381 | unsigned nargs = call_nargs (exp); | |
382 | if (!nargs) | |
383 | return false; | |
384 | ||
385 | /* The bound argument to a bounded string function like strncpy. */ | |
386 | tree bound = NULL_TREE; | |
387 | ||
388 | /* The longest known or possible string argument to one of the comparison | |
389 | functions. If the length is less than the bound it is used instead. | |
390 | Since the length is only used for warning and not for code generation | |
391 | disable strict mode in the calls to get_range_strlen below. */ | |
392 | tree maxlen = NULL_TREE; | |
393 | ||
394 | /* It's safe to call "bounded" string functions with a non-string | |
395 | argument since the functions provide an explicit bound for this | |
396 | purpose. The exception is strncat where the bound may refer to | |
397 | either the destination or the source. */ | |
398 | int fncode = DECL_FUNCTION_CODE (fndecl); | |
399 | switch (fncode) | |
400 | { | |
401 | case BUILT_IN_STRCMP: | |
402 | case BUILT_IN_STRNCMP: | |
403 | case BUILT_IN_STRNCASECMP: | |
404 | { | |
405 | /* For these, if one argument refers to one or more of a set | |
406 | of string constants or arrays of known size, determine | |
407 | the range of their known or possible lengths and use it | |
408 | conservatively as the bound for the unbounded function, | |
409 | and to adjust the range of the bound of the bounded ones. */ | |
410 | for (unsigned argno = 0; | |
411 | argno < MIN (nargs, 2) | |
412 | && !(maxlen && TREE_CODE (maxlen) == INTEGER_CST); argno++) | |
413 | { | |
414 | tree arg = call_arg (exp, argno); | |
415 | if (!get_attr_nonstring_decl (arg)) | |
416 | { | |
417 | c_strlen_data lendata = { }; | |
418 | /* Set MAXBOUND to an arbitrary non-null non-integer | |
419 | node as a request to have it set to the length of | |
420 | the longest string in a PHI. */ | |
421 | lendata.maxbound = arg; | |
422 | get_range_strlen (arg, &lendata, /* eltsize = */ 1); | |
423 | maxlen = lendata.maxbound; | |
424 | } | |
425 | } | |
426 | } | |
427 | /* Fall through. */ | |
428 | ||
429 | case BUILT_IN_STRNCAT: | |
430 | case BUILT_IN_STPNCPY: | |
431 | case BUILT_IN_STRNCPY: | |
432 | if (nargs > 2) | |
433 | bound = call_arg (exp, 2); | |
434 | break; | |
435 | ||
436 | case BUILT_IN_STRNDUP: | |
437 | if (nargs < 2) | |
438 | return false; | |
439 | bound = call_arg (exp, 1); | |
440 | break; | |
441 | ||
442 | case BUILT_IN_STRNLEN: | |
443 | { | |
444 | tree arg = call_arg (exp, 0); | |
445 | if (!get_attr_nonstring_decl (arg)) | |
446 | { | |
447 | c_strlen_data lendata = { }; | |
448 | /* Set MAXBOUND to an arbitrary non-null non-integer | |
449 | node as a request to have it set to the length of | |
450 | the longest string in a PHI. */ | |
451 | lendata.maxbound = arg; | |
452 | get_range_strlen (arg, &lendata, /* eltsize = */ 1); | |
453 | maxlen = lendata.maxbound; | |
454 | } | |
455 | if (nargs > 1) | |
456 | bound = call_arg (exp, 1); | |
457 | break; | |
458 | } | |
459 | ||
460 | default: | |
461 | break; | |
462 | } | |
463 | ||
464 | /* Determine the range of the bound argument (if specified). */ | |
465 | tree bndrng[2] = { NULL_TREE, NULL_TREE }; | |
466 | if (bound) | |
467 | { | |
468 | STRIP_NOPS (bound); | |
469 | get_size_range (bound, bndrng); | |
470 | } | |
471 | ||
472 | location_t loc = get_location (exp); | |
473 | ||
474 | if (bndrng[0]) | |
475 | { | |
476 | /* Diagnose excessive bound prior to the adjustment below and | |
477 | regardless of attribute nonstring. */ | |
478 | tree maxobjsize = max_object_size (); | |
479 | if (tree_int_cst_lt (maxobjsize, bndrng[0])) | |
2a837de2 | 480 | { |
81d6cdd3 MS |
481 | bool warned = false; |
482 | if (tree_int_cst_equal (bndrng[0], bndrng[1])) | |
483 | warned = warning_at (loc, OPT_Wstringop_overread, | |
484 | "%qD specified bound %E " | |
485 | "exceeds maximum object size %E", | |
486 | fndecl, bndrng[0], maxobjsize); | |
487 | else | |
488 | warned = warning_at (loc, OPT_Wstringop_overread, | |
489 | "%qD specified bound [%E, %E] " | |
490 | "exceeds maximum object size %E", | |
491 | fndecl, bndrng[0], bndrng[1], | |
492 | maxobjsize); | |
493 | if (warned) | |
494 | suppress_warning (exp, OPT_Wstringop_overread); | |
495 | ||
496 | return warned; | |
497 | } | |
498 | } | |
499 | ||
500 | if (maxlen && !integer_all_onesp (maxlen)) | |
501 | { | |
502 | /* Add one for the nul. */ | |
503 | maxlen = const_binop (PLUS_EXPR, TREE_TYPE (maxlen), maxlen, | |
504 | size_one_node); | |
505 | ||
506 | if (!bndrng[0]) | |
507 | { | |
508 | /* Conservatively use the upper bound of the lengths for | |
509 | both the lower and the upper bound of the operation. */ | |
510 | bndrng[0] = maxlen; | |
511 | bndrng[1] = maxlen; | |
512 | bound = void_type_node; | |
513 | } | |
514 | else if (maxlen) | |
515 | { | |
516 | /* Replace the bound on the operation with the upper bound | |
517 | of the length of the string if the latter is smaller. */ | |
518 | if (tree_int_cst_lt (maxlen, bndrng[0])) | |
519 | bndrng[0] = maxlen; | |
520 | else if (tree_int_cst_lt (maxlen, bndrng[1])) | |
521 | bndrng[1] = maxlen; | |
522 | } | |
523 | } | |
524 | ||
525 | bool any_arg_warned = false; | |
526 | /* Iterate over the built-in function's formal arguments and check | |
527 | each const char* against the actual argument. If the actual | |
528 | argument is declared attribute non-string issue a warning unless | |
529 | the argument's maximum length is bounded. */ | |
530 | function_args_iterator it; | |
531 | function_args_iter_init (&it, TREE_TYPE (fndecl)); | |
532 | ||
533 | for (unsigned argno = 0; ; ++argno, function_args_iter_next (&it)) | |
534 | { | |
535 | /* Avoid iterating past the declared argument in a call | |
536 | to function declared without a prototype. */ | |
537 | if (argno >= nargs) | |
538 | break; | |
539 | ||
540 | tree argtype = function_args_iter_cond (&it); | |
541 | if (!argtype) | |
542 | break; | |
543 | ||
544 | if (TREE_CODE (argtype) != POINTER_TYPE) | |
545 | continue; | |
546 | ||
547 | argtype = TREE_TYPE (argtype); | |
548 | ||
549 | if (TREE_CODE (argtype) != INTEGER_TYPE | |
550 | || !TYPE_READONLY (argtype)) | |
551 | continue; | |
552 | ||
553 | argtype = TYPE_MAIN_VARIANT (argtype); | |
554 | if (argtype != char_type_node) | |
555 | continue; | |
556 | ||
557 | tree callarg = call_arg (exp, argno); | |
558 | if (TREE_CODE (callarg) == ADDR_EXPR) | |
559 | callarg = TREE_OPERAND (callarg, 0); | |
560 | ||
561 | /* See if the destination is declared with attribute "nonstring". */ | |
562 | tree decl = get_attr_nonstring_decl (callarg); | |
563 | if (!decl) | |
564 | continue; | |
565 | ||
566 | /* The maximum number of array elements accessed. */ | |
567 | offset_int wibnd = 0; | |
568 | ||
569 | if (argno && fncode == BUILT_IN_STRNCAT) | |
570 | { | |
571 | /* See if the bound in strncat is derived from the length | |
572 | of the strlen of the destination (as it's expected to be). | |
573 | If so, reset BOUND and FNCODE to trigger a warning. */ | |
574 | tree dstarg = call_arg (exp, 0); | |
575 | if (is_strlen_related_p (dstarg, bound)) | |
576 | { | |
577 | /* The bound applies to the destination, not to the source, | |
578 | so reset these to trigger a warning without mentioning | |
579 | the bound. */ | |
580 | bound = NULL; | |
581 | fncode = 0; | |
582 | } | |
583 | else if (bndrng[1]) | |
584 | /* Use the upper bound of the range for strncat. */ | |
585 | wibnd = wi::to_offset (bndrng[1]); | |
586 | } | |
587 | else if (bndrng[0]) | |
588 | /* Use the lower bound of the range for functions other than | |
589 | strncat. */ | |
590 | wibnd = wi::to_offset (bndrng[0]); | |
591 | ||
592 | /* Determine the size of the argument array if it is one. */ | |
593 | offset_int asize = wibnd; | |
594 | bool known_size = false; | |
595 | tree type = TREE_TYPE (decl); | |
596 | ||
597 | /* Determine the array size. For arrays of unknown bound and | |
598 | pointers reset BOUND to trigger the appropriate warning. */ | |
599 | if (TREE_CODE (type) == ARRAY_TYPE) | |
600 | { | |
601 | if (tree arrbnd = TYPE_DOMAIN (type)) | |
2a837de2 | 602 | { |
81d6cdd3 | 603 | if ((arrbnd = TYPE_MAX_VALUE (arrbnd))) |
2a837de2 | 604 | { |
81d6cdd3 MS |
605 | asize = wi::to_offset (arrbnd) + 1; |
606 | known_size = true; | |
2a837de2 | 607 | } |
2a837de2 | 608 | } |
81d6cdd3 MS |
609 | else if (bound == void_type_node) |
610 | bound = NULL_TREE; | |
611 | } | |
612 | else if (bound == void_type_node) | |
613 | bound = NULL_TREE; | |
614 | ||
615 | /* In a call to strncat with a bound in a range whose lower but | |
616 | not upper bound is less than the array size, reset ASIZE to | |
617 | be the same as the bound and the other variable to trigger | |
618 | the apprpriate warning below. */ | |
619 | if (fncode == BUILT_IN_STRNCAT | |
620 | && bndrng[0] != bndrng[1] | |
621 | && wi::ltu_p (wi::to_offset (bndrng[0]), asize) | |
622 | && (!known_size | |
623 | || wi::ltu_p (asize, wibnd))) | |
624 | { | |
625 | asize = wibnd; | |
626 | bound = NULL_TREE; | |
627 | fncode = 0; | |
628 | } | |
629 | ||
630 | bool warned = false; | |
631 | ||
632 | auto_diagnostic_group d; | |
633 | if (wi::ltu_p (asize, wibnd)) | |
634 | { | |
635 | if (bndrng[0] == bndrng[1]) | |
636 | warned = warning_at (loc, OPT_Wstringop_overread, | |
637 | "%qD argument %i declared attribute " | |
638 | "%<nonstring%> is smaller than the specified " | |
639 | "bound %wu", | |
640 | fndecl, argno + 1, wibnd.to_uhwi ()); | |
641 | else if (wi::ltu_p (asize, wi::to_offset (bndrng[0]))) | |
642 | warned = warning_at (loc, OPT_Wstringop_overread, | |
643 | "%qD argument %i declared attribute " | |
644 | "%<nonstring%> is smaller than " | |
645 | "the specified bound [%E, %E]", | |
646 | fndecl, argno + 1, bndrng[0], bndrng[1]); | |
2a837de2 | 647 | else |
81d6cdd3 MS |
648 | warned = warning_at (loc, OPT_Wstringop_overread, |
649 | "%qD argument %i declared attribute " | |
650 | "%<nonstring%> may be smaller than " | |
651 | "the specified bound [%E, %E]", | |
652 | fndecl, argno + 1, bndrng[0], bndrng[1]); | |
653 | } | |
654 | else if (fncode == BUILT_IN_STRNCAT) | |
655 | ; /* Avoid warning for calls to strncat() when the bound | |
656 | is equal to the size of the non-string argument. */ | |
657 | else if (!bound) | |
658 | warned = warning_at (loc, OPT_Wstringop_overread, | |
659 | "%qD argument %i declared attribute %<nonstring%>", | |
660 | fndecl, argno + 1); | |
2a837de2 | 661 | |
81d6cdd3 MS |
662 | if (warned) |
663 | { | |
664 | inform (DECL_SOURCE_LOCATION (decl), | |
665 | "argument %qD declared here", decl); | |
666 | any_arg_warned = true; | |
2a837de2 | 667 | } |
81d6cdd3 MS |
668 | } |
669 | ||
670 | if (any_arg_warned) | |
671 | suppress_warning (exp, OPT_Wstringop_overread); | |
672 | ||
673 | return any_arg_warned; | |
674 | } | |
675 | ||
676 | bool | |
677 | maybe_warn_nonstring_arg (tree fndecl, gimple *stmt) | |
678 | { | |
679 | return maybe_warn_nonstring_arg<gimple *>(fndecl, stmt); | |
680 | } | |
2a837de2 | 681 | |
81d6cdd3 MS |
682 | |
683 | bool | |
684 | maybe_warn_nonstring_arg (tree fndecl, tree expr) | |
685 | { | |
686 | return maybe_warn_nonstring_arg<tree>(fndecl, expr); | |
2a837de2 MS |
687 | } |
688 | ||
689 | /* Issue a warning OPT for a bounded call EXP with a bound in RANGE | |
690 | accessing an object with SIZE. */ | |
691 | ||
81d6cdd3 MS |
692 | template <class GimpleOrTree> |
693 | static bool | |
694 | maybe_warn_for_bound (opt_code opt, location_t loc, GimpleOrTree exp, tree func, | |
695 | tree bndrng[2], tree size, const access_data *pad) | |
2a837de2 MS |
696 | { |
697 | if (!bndrng[0] || warning_suppressed_p (exp, opt)) | |
698 | return false; | |
699 | ||
700 | tree maxobjsize = max_object_size (); | |
701 | ||
702 | bool warned = false; | |
703 | ||
704 | if (opt == OPT_Wstringop_overread) | |
705 | { | |
706 | bool maybe = pad && pad->src.phi (); | |
820f0940 MS |
707 | if (maybe) |
708 | { | |
709 | /* Issue a "maybe" warning only if the PHI refers to objects | |
710 | at least one of which has more space remaining than the bound. | |
711 | Otherwise, if the bound is greater, use the definitive form. */ | |
712 | offset_int remmax = pad->src.size_remaining (); | |
713 | if (remmax < wi::to_offset (bndrng[0])) | |
714 | maybe = false; | |
715 | } | |
2a837de2 MS |
716 | |
717 | if (tree_int_cst_lt (maxobjsize, bndrng[0])) | |
718 | { | |
719 | if (bndrng[0] == bndrng[1]) | |
720 | warned = (func | |
721 | ? warning_at (loc, opt, | |
722 | (maybe | |
723 | ? G_("%qD specified bound %E may " | |
724 | "exceed maximum object size %E") | |
725 | : G_("%qD specified bound %E " | |
726 | "exceeds maximum object size %E")), | |
727 | func, bndrng[0], maxobjsize) | |
728 | : warning_at (loc, opt, | |
729 | (maybe | |
730 | ? G_("specified bound %E may " | |
731 | "exceed maximum object size %E") | |
732 | : G_("specified bound %E " | |
733 | "exceeds maximum object size %E")), | |
734 | bndrng[0], maxobjsize)); | |
735 | else | |
736 | warned = (func | |
737 | ? warning_at (loc, opt, | |
738 | (maybe | |
739 | ? G_("%qD specified bound [%E, %E] may " | |
740 | "exceed maximum object size %E") | |
741 | : G_("%qD specified bound [%E, %E] " | |
742 | "exceeds maximum object size %E")), | |
743 | func, | |
744 | bndrng[0], bndrng[1], maxobjsize) | |
745 | : warning_at (loc, opt, | |
746 | (maybe | |
747 | ? G_("specified bound [%E, %E] may " | |
748 | "exceed maximum object size %E") | |
749 | : G_("specified bound [%E, %E] " | |
750 | "exceeds maximum object size %E")), | |
751 | bndrng[0], bndrng[1], maxobjsize)); | |
752 | } | |
753 | else if (!size || tree_int_cst_le (bndrng[0], size)) | |
754 | return false; | |
755 | else if (tree_int_cst_equal (bndrng[0], bndrng[1])) | |
756 | warned = (func | |
757 | ? warning_at (loc, opt, | |
758 | (maybe | |
759 | ? G_("%qD specified bound %E may exceed " | |
760 | "source size %E") | |
761 | : G_("%qD specified bound %E exceeds " | |
762 | "source size %E")), | |
763 | func, bndrng[0], size) | |
764 | : warning_at (loc, opt, | |
765 | (maybe | |
766 | ? G_("specified bound %E may exceed " | |
767 | "source size %E") | |
768 | : G_("specified bound %E exceeds " | |
769 | "source size %E")), | |
770 | bndrng[0], size)); | |
771 | else | |
772 | warned = (func | |
773 | ? warning_at (loc, opt, | |
774 | (maybe | |
775 | ? G_("%qD specified bound [%E, %E] may " | |
776 | "exceed source size %E") | |
777 | : G_("%qD specified bound [%E, %E] exceeds " | |
778 | "source size %E")), | |
779 | func, bndrng[0], bndrng[1], size) | |
780 | : warning_at (loc, opt, | |
781 | (maybe | |
782 | ? G_("specified bound [%E, %E] may exceed " | |
783 | "source size %E") | |
784 | : G_("specified bound [%E, %E] exceeds " | |
785 | "source size %E")), | |
786 | bndrng[0], bndrng[1], size)); | |
787 | if (warned) | |
788 | { | |
81d6cdd3 MS |
789 | if (pad && pad->src.ref |
790 | && has_location (pad->src.ref)) | |
791 | inform (get_location (pad->src.ref), | |
792 | "source object allocated here"); | |
2a837de2 MS |
793 | suppress_warning (exp, opt); |
794 | } | |
795 | ||
796 | return warned; | |
797 | } | |
798 | ||
799 | bool maybe = pad && pad->dst.phi (); | |
820f0940 MS |
800 | if (maybe) |
801 | { | |
802 | /* Issue a "maybe" warning only if the PHI refers to objects | |
803 | at least one of which has more space remaining than the bound. | |
804 | Otherwise, if the bound is greater, use the definitive form. */ | |
805 | offset_int remmax = pad->dst.size_remaining (); | |
806 | if (remmax < wi::to_offset (bndrng[0])) | |
807 | maybe = false; | |
808 | } | |
2a837de2 MS |
809 | if (tree_int_cst_lt (maxobjsize, bndrng[0])) |
810 | { | |
811 | if (bndrng[0] == bndrng[1]) | |
812 | warned = (func | |
813 | ? warning_at (loc, opt, | |
814 | (maybe | |
815 | ? G_("%qD specified size %E may " | |
816 | "exceed maximum object size %E") | |
817 | : G_("%qD specified size %E " | |
818 | "exceeds maximum object size %E")), | |
819 | func, bndrng[0], maxobjsize) | |
820 | : warning_at (loc, opt, | |
821 | (maybe | |
822 | ? G_("specified size %E may exceed " | |
823 | "maximum object size %E") | |
824 | : G_("specified size %E exceeds " | |
825 | "maximum object size %E")), | |
826 | bndrng[0], maxobjsize)); | |
827 | else | |
828 | warned = (func | |
829 | ? warning_at (loc, opt, | |
830 | (maybe | |
831 | ? G_("%qD specified size between %E and %E " | |
832 | "may exceed maximum object size %E") | |
833 | : G_("%qD specified size between %E and %E " | |
834 | "exceeds maximum object size %E")), | |
835 | func, bndrng[0], bndrng[1], maxobjsize) | |
836 | : warning_at (loc, opt, | |
837 | (maybe | |
838 | ? G_("specified size between %E and %E " | |
839 | "may exceed maximum object size %E") | |
840 | : G_("specified size between %E and %E " | |
841 | "exceeds maximum object size %E")), | |
842 | bndrng[0], bndrng[1], maxobjsize)); | |
843 | } | |
844 | else if (!size || tree_int_cst_le (bndrng[0], size)) | |
845 | return false; | |
846 | else if (tree_int_cst_equal (bndrng[0], bndrng[1])) | |
847 | warned = (func | |
848 | ? warning_at (loc, opt, | |
849 | (maybe | |
850 | ? G_("%qD specified bound %E may exceed " | |
851 | "destination size %E") | |
852 | : G_("%qD specified bound %E exceeds " | |
853 | "destination size %E")), | |
854 | func, bndrng[0], size) | |
855 | : warning_at (loc, opt, | |
856 | (maybe | |
857 | ? G_("specified bound %E may exceed " | |
858 | "destination size %E") | |
859 | : G_("specified bound %E exceeds " | |
860 | "destination size %E")), | |
861 | bndrng[0], size)); | |
862 | else | |
863 | warned = (func | |
864 | ? warning_at (loc, opt, | |
865 | (maybe | |
866 | ? G_("%qD specified bound [%E, %E] may exceed " | |
867 | "destination size %E") | |
868 | : G_("%qD specified bound [%E, %E] exceeds " | |
869 | "destination size %E")), | |
870 | func, bndrng[0], bndrng[1], size) | |
871 | : warning_at (loc, opt, | |
872 | (maybe | |
873 | ? G_("specified bound [%E, %E] exceeds " | |
874 | "destination size %E") | |
875 | : G_("specified bound [%E, %E] exceeds " | |
876 | "destination size %E")), | |
877 | bndrng[0], bndrng[1], size)); | |
878 | ||
879 | if (warned) | |
880 | { | |
81d6cdd3 MS |
881 | if (pad && pad->dst.ref |
882 | && has_location (pad->dst.ref)) | |
883 | inform (get_location (pad->dst.ref), | |
884 | "destination object allocated here"); | |
2a837de2 MS |
885 | suppress_warning (exp, opt); |
886 | } | |
887 | ||
888 | return warned; | |
889 | } | |
890 | ||
81d6cdd3 MS |
891 | bool |
892 | maybe_warn_for_bound (opt_code opt, location_t loc, gimple *stmt, tree func, | |
893 | tree bndrng[2], tree size, | |
894 | const access_data *pad /* = NULL */) | |
895 | { | |
896 | return maybe_warn_for_bound<gimple *> (opt, loc, stmt, func, bndrng, size, | |
897 | pad); | |
898 | } | |
899 | ||
900 | bool | |
901 | maybe_warn_for_bound (opt_code opt, location_t loc, tree expr, tree func, | |
902 | tree bndrng[2], tree size, | |
903 | const access_data *pad /* = NULL */) | |
904 | { | |
905 | return maybe_warn_for_bound<tree> (opt, loc, expr, func, bndrng, size, pad); | |
906 | } | |
907 | ||
2a837de2 MS |
908 | /* For an expression EXP issue an access warning controlled by option OPT |
909 | with access to a region SIZE bytes in size in the RANGE of sizes. | |
910 | WRITE is true for a write access, READ for a read access, neither for | |
911 | call that may or may not perform an access but for which the range | |
912 | is expected to valid. | |
913 | Returns true when a warning has been issued. */ | |
914 | ||
81d6cdd3 | 915 | template <class GimpleOrTree> |
2a837de2 | 916 | static bool |
81d6cdd3 MS |
917 | warn_for_access (location_t loc, tree func, GimpleOrTree exp, int opt, |
918 | tree range[2], tree size, bool write, bool read, bool maybe) | |
2a837de2 MS |
919 | { |
920 | bool warned = false; | |
921 | ||
922 | if (write && read) | |
923 | { | |
924 | if (tree_int_cst_equal (range[0], range[1])) | |
925 | warned = (func | |
926 | ? warning_n (loc, opt, tree_to_uhwi (range[0]), | |
927 | (maybe | |
928 | ? G_("%qD may access %E byte in a region " | |
929 | "of size %E") | |
930 | : G_("%qD accessing %E byte in a region " | |
931 | "of size %E")), | |
932 | (maybe | |
933 | ? G_ ("%qD may access %E bytes in a region " | |
934 | "of size %E") | |
935 | : G_ ("%qD accessing %E bytes in a region " | |
936 | "of size %E")), | |
937 | func, range[0], size) | |
938 | : warning_n (loc, opt, tree_to_uhwi (range[0]), | |
939 | (maybe | |
940 | ? G_("may access %E byte in a region " | |
941 | "of size %E") | |
942 | : G_("accessing %E byte in a region " | |
943 | "of size %E")), | |
944 | (maybe | |
945 | ? G_("may access %E bytes in a region " | |
946 | "of size %E") | |
947 | : G_("accessing %E bytes in a region " | |
948 | "of size %E")), | |
949 | range[0], size)); | |
950 | else if (tree_int_cst_sign_bit (range[1])) | |
951 | { | |
952 | /* Avoid printing the upper bound if it's invalid. */ | |
953 | warned = (func | |
954 | ? warning_at (loc, opt, | |
955 | (maybe | |
956 | ? G_("%qD may access %E or more bytes " | |
957 | "in a region of size %E") | |
958 | : G_("%qD accessing %E or more bytes " | |
959 | "in a region of size %E")), | |
960 | func, range[0], size) | |
961 | : warning_at (loc, opt, | |
962 | (maybe | |
963 | ? G_("may access %E or more bytes " | |
964 | "in a region of size %E") | |
965 | : G_("accessing %E or more bytes " | |
966 | "in a region of size %E")), | |
967 | range[0], size)); | |
968 | } | |
969 | else | |
970 | warned = (func | |
971 | ? warning_at (loc, opt, | |
972 | (maybe | |
973 | ? G_("%qD may access between %E and %E " | |
974 | "bytes in a region of size %E") | |
975 | : G_("%qD accessing between %E and %E " | |
976 | "bytes in a region of size %E")), | |
977 | func, range[0], range[1], size) | |
978 | : warning_at (loc, opt, | |
979 | (maybe | |
980 | ? G_("may access between %E and %E bytes " | |
981 | "in a region of size %E") | |
982 | : G_("accessing between %E and %E bytes " | |
983 | "in a region of size %E")), | |
984 | range[0], range[1], size)); | |
985 | return warned; | |
986 | } | |
987 | ||
988 | if (write) | |
989 | { | |
990 | if (tree_int_cst_equal (range[0], range[1])) | |
991 | warned = (func | |
992 | ? warning_n (loc, opt, tree_to_uhwi (range[0]), | |
993 | (maybe | |
994 | ? G_("%qD may write %E byte into a region " | |
995 | "of size %E") | |
996 | : G_("%qD writing %E byte into a region " | |
997 | "of size %E overflows the destination")), | |
998 | (maybe | |
999 | ? G_("%qD may write %E bytes into a region " | |
1000 | "of size %E") | |
1001 | : G_("%qD writing %E bytes into a region " | |
1002 | "of size %E overflows the destination")), | |
1003 | func, range[0], size) | |
1004 | : warning_n (loc, opt, tree_to_uhwi (range[0]), | |
1005 | (maybe | |
1006 | ? G_("may write %E byte into a region " | |
1007 | "of size %E") | |
1008 | : G_("writing %E byte into a region " | |
1009 | "of size %E overflows the destination")), | |
1010 | (maybe | |
1011 | ? G_("may write %E bytes into a region " | |
1012 | "of size %E") | |
1013 | : G_("writing %E bytes into a region " | |
1014 | "of size %E overflows the destination")), | |
1015 | range[0], size)); | |
1016 | else if (tree_int_cst_sign_bit (range[1])) | |
1017 | { | |
1018 | /* Avoid printing the upper bound if it's invalid. */ | |
1019 | warned = (func | |
1020 | ? warning_at (loc, opt, | |
1021 | (maybe | |
1022 | ? G_("%qD may write %E or more bytes " | |
1023 | "into a region of size %E") | |
1024 | : G_("%qD writing %E or more bytes " | |
1025 | "into a region of size %E overflows " | |
1026 | "the destination")), | |
1027 | func, range[0], size) | |
1028 | : warning_at (loc, opt, | |
1029 | (maybe | |
1030 | ? G_("may write %E or more bytes into " | |
1031 | "a region of size %E") | |
1032 | : G_("writing %E or more bytes into " | |
1033 | "a region of size %E overflows " | |
1034 | "the destination")), | |
1035 | range[0], size)); | |
1036 | } | |
1037 | else | |
1038 | warned = (func | |
1039 | ? warning_at (loc, opt, | |
1040 | (maybe | |
1041 | ? G_("%qD may write between %E and %E bytes " | |
1042 | "into a region of size %E") | |
1043 | : G_("%qD writing between %E and %E bytes " | |
1044 | "into a region of size %E overflows " | |
1045 | "the destination")), | |
1046 | func, range[0], range[1], size) | |
1047 | : warning_at (loc, opt, | |
1048 | (maybe | |
1049 | ? G_("may write between %E and %E bytes " | |
1050 | "into a region of size %E") | |
1051 | : G_("writing between %E and %E bytes " | |
1052 | "into a region of size %E overflows " | |
1053 | "the destination")), | |
1054 | range[0], range[1], size)); | |
1055 | return warned; | |
1056 | } | |
1057 | ||
1058 | if (read) | |
1059 | { | |
1060 | if (tree_int_cst_equal (range[0], range[1])) | |
1061 | warned = (func | |
1062 | ? warning_n (loc, OPT_Wstringop_overread, | |
1063 | tree_to_uhwi (range[0]), | |
1064 | (maybe | |
1065 | ? G_("%qD may read %E byte from a region " | |
1066 | "of size %E") | |
1067 | : G_("%qD reading %E byte from a region " | |
1068 | "of size %E")), | |
1069 | (maybe | |
1070 | ? G_("%qD may read %E bytes from a region " | |
1071 | "of size %E") | |
1072 | : G_("%qD reading %E bytes from a region " | |
1073 | "of size %E")), | |
1074 | func, range[0], size) | |
1075 | : warning_n (loc, OPT_Wstringop_overread, | |
1076 | tree_to_uhwi (range[0]), | |
1077 | (maybe | |
1078 | ? G_("may read %E byte from a region " | |
1079 | "of size %E") | |
1080 | : G_("reading %E byte from a region " | |
1081 | "of size %E")), | |
1082 | (maybe | |
1083 | ? G_("may read %E bytes from a region " | |
1084 | "of size %E") | |
1085 | : G_("reading %E bytes from a region " | |
1086 | "of size %E")), | |
1087 | range[0], size)); | |
1088 | else if (tree_int_cst_sign_bit (range[1])) | |
1089 | { | |
1090 | /* Avoid printing the upper bound if it's invalid. */ | |
1091 | warned = (func | |
1092 | ? warning_at (loc, OPT_Wstringop_overread, | |
1093 | (maybe | |
1094 | ? G_("%qD may read %E or more bytes " | |
1095 | "from a region of size %E") | |
1096 | : G_("%qD reading %E or more bytes " | |
1097 | "from a region of size %E")), | |
1098 | func, range[0], size) | |
1099 | : warning_at (loc, OPT_Wstringop_overread, | |
1100 | (maybe | |
1101 | ? G_("may read %E or more bytes " | |
1102 | "from a region of size %E") | |
1103 | : G_("reading %E or more bytes " | |
1104 | "from a region of size %E")), | |
1105 | range[0], size)); | |
1106 | } | |
1107 | else | |
1108 | warned = (func | |
1109 | ? warning_at (loc, OPT_Wstringop_overread, | |
1110 | (maybe | |
1111 | ? G_("%qD may read between %E and %E bytes " | |
1112 | "from a region of size %E") | |
1113 | : G_("%qD reading between %E and %E bytes " | |
1114 | "from a region of size %E")), | |
1115 | func, range[0], range[1], size) | |
1116 | : warning_at (loc, opt, | |
1117 | (maybe | |
1118 | ? G_("may read between %E and %E bytes " | |
1119 | "from a region of size %E") | |
1120 | : G_("reading between %E and %E bytes " | |
1121 | "from a region of size %E")), | |
1122 | range[0], range[1], size)); | |
1123 | ||
1124 | if (warned) | |
1125 | suppress_warning (exp, OPT_Wstringop_overread); | |
1126 | ||
1127 | return warned; | |
1128 | } | |
1129 | ||
1130 | if (tree_int_cst_equal (range[0], range[1]) | |
1131 | || tree_int_cst_sign_bit (range[1])) | |
1132 | warned = (func | |
1133 | ? warning_n (loc, OPT_Wstringop_overread, | |
1134 | tree_to_uhwi (range[0]), | |
1135 | "%qD expecting %E byte in a region of size %E", | |
1136 | "%qD expecting %E bytes in a region of size %E", | |
1137 | func, range[0], size) | |
1138 | : warning_n (loc, OPT_Wstringop_overread, | |
1139 | tree_to_uhwi (range[0]), | |
1140 | "expecting %E byte in a region of size %E", | |
1141 | "expecting %E bytes in a region of size %E", | |
1142 | range[0], size)); | |
1143 | else if (tree_int_cst_sign_bit (range[1])) | |
1144 | { | |
1145 | /* Avoid printing the upper bound if it's invalid. */ | |
1146 | warned = (func | |
1147 | ? warning_at (loc, OPT_Wstringop_overread, | |
1148 | "%qD expecting %E or more bytes in a region " | |
1149 | "of size %E", | |
1150 | func, range[0], size) | |
1151 | : warning_at (loc, OPT_Wstringop_overread, | |
1152 | "expecting %E or more bytes in a region " | |
1153 | "of size %E", | |
1154 | range[0], size)); | |
1155 | } | |
1156 | else | |
1157 | warned = (func | |
1158 | ? warning_at (loc, OPT_Wstringop_overread, | |
1159 | "%qD expecting between %E and %E bytes in " | |
1160 | "a region of size %E", | |
1161 | func, range[0], range[1], size) | |
1162 | : warning_at (loc, OPT_Wstringop_overread, | |
1163 | "expecting between %E and %E bytes in " | |
1164 | "a region of size %E", | |
1165 | range[0], range[1], size)); | |
1166 | ||
1167 | if (warned) | |
1168 | suppress_warning (exp, OPT_Wstringop_overread); | |
1169 | ||
1170 | return warned; | |
1171 | } | |
1172 | ||
81d6cdd3 MS |
1173 | static bool |
1174 | warn_for_access (location_t loc, tree func, gimple *stmt, int opt, | |
1175 | tree range[2], tree size, bool write, bool read, bool maybe) | |
1176 | { | |
1177 | return warn_for_access<gimple *>(loc, func, stmt, opt, range, size, | |
1178 | write, read, maybe); | |
1179 | } | |
1180 | ||
1181 | static bool | |
1182 | warn_for_access (location_t loc, tree func, tree expr, int opt, | |
1183 | tree range[2], tree size, bool write, bool read, bool maybe) | |
1184 | { | |
1185 | return warn_for_access<tree>(loc, func, expr, opt, range, size, | |
1186 | write, read, maybe); | |
1187 | } | |
1188 | ||
2a837de2 MS |
1189 | /* Helper to set RANGE to the range of BOUND if it's nonnull, bounded |
1190 | by BNDRNG if nonnull and valid. */ | |
1191 | ||
b48d4e68 | 1192 | static void |
9a27acc3 | 1193 | get_size_range (range_query *query, tree bound, gimple *stmt, tree range[2], |
ece28da9 | 1194 | const offset_int bndrng[2]) |
2a837de2 MS |
1195 | { |
1196 | if (bound) | |
9a27acc3 | 1197 | get_size_range (query, bound, stmt, range); |
2a837de2 MS |
1198 | |
1199 | if (!bndrng || (bndrng[0] == 0 && bndrng[1] == HOST_WIDE_INT_M1U)) | |
1200 | return; | |
1201 | ||
1202 | if (range[0] && TREE_CODE (range[0]) == INTEGER_CST) | |
1203 | { | |
1204 | offset_int r[] = | |
1205 | { wi::to_offset (range[0]), wi::to_offset (range[1]) }; | |
1206 | if (r[0] < bndrng[0]) | |
1207 | range[0] = wide_int_to_tree (sizetype, bndrng[0]); | |
1208 | if (bndrng[1] < r[1]) | |
1209 | range[1] = wide_int_to_tree (sizetype, bndrng[1]); | |
1210 | } | |
1211 | else | |
1212 | { | |
1213 | range[0] = wide_int_to_tree (sizetype, bndrng[0]); | |
1214 | range[1] = wide_int_to_tree (sizetype, bndrng[1]); | |
1215 | } | |
1216 | } | |
1217 | ||
1218 | /* Try to verify that the sizes and lengths of the arguments to a string | |
1219 | manipulation function given by EXP are within valid bounds and that | |
1220 | the operation does not lead to buffer overflow or read past the end. | |
1221 | Arguments other than EXP may be null. When non-null, the arguments | |
1222 | have the following meaning: | |
1223 | DST is the destination of a copy call or NULL otherwise. | |
1224 | SRC is the source of a copy call or NULL otherwise. | |
1225 | DSTWRITE is the number of bytes written into the destination obtained | |
1226 | from the user-supplied size argument to the function (such as in | |
1227 | memcpy(DST, SRCs, DSTWRITE) or strncpy(DST, DRC, DSTWRITE). | |
1228 | MAXREAD is the user-supplied bound on the length of the source sequence | |
1229 | (such as in strncat(d, s, N). It specifies the upper limit on the number | |
1230 | of bytes to write. If NULL, it's taken to be the same as DSTWRITE. | |
1231 | SRCSTR is the source string (such as in strcpy(DST, SRC)) when the | |
1232 | expression EXP is a string function call (as opposed to a memory call | |
1233 | like memcpy). As an exception, SRCSTR can also be an integer denoting | |
1234 | the precomputed size of the source string or object (for functions like | |
1235 | memcpy). | |
1236 | DSTSIZE is the size of the destination object. | |
1237 | ||
1238 | When DSTWRITE is null LEN is checked to verify that it doesn't exceed | |
1239 | SIZE_MAX. | |
1240 | ||
1241 | WRITE is true for write accesses, READ is true for reads. Both are | |
1242 | false for simple size checks in calls to functions that neither read | |
1243 | from nor write to the region. | |
1244 | ||
1245 | When nonnull, PAD points to a more detailed description of the access. | |
1246 | ||
1247 | If the call is successfully verified as safe return true, otherwise | |
1248 | return false. */ | |
1249 | ||
81d6cdd3 MS |
1250 | template <class GimpleOrTree> |
1251 | static bool | |
1252 | check_access (GimpleOrTree exp, tree dstwrite, | |
2a837de2 | 1253 | tree maxread, tree srcstr, tree dstsize, |
9a27acc3 MS |
1254 | access_mode mode, const access_data *pad, |
1255 | range_query *rvals) | |
2a837de2 MS |
1256 | { |
1257 | /* The size of the largest object is half the address space, or | |
1258 | PTRDIFF_MAX. (This is way too permissive.) */ | |
1259 | tree maxobjsize = max_object_size (); | |
1260 | ||
1261 | /* Either an approximate/minimum the length of the source string for | |
1262 | string functions or the size of the source object for raw memory | |
1263 | functions. */ | |
1264 | tree slen = NULL_TREE; | |
1265 | ||
1266 | /* The range of the access in bytes; first set to the write access | |
1267 | for functions that write and then read for those that also (or | |
1268 | just) read. */ | |
1269 | tree range[2] = { NULL_TREE, NULL_TREE }; | |
1270 | ||
1271 | /* Set to true when the exact number of bytes written by a string | |
1272 | function like strcpy is not known and the only thing that is | |
1273 | known is that it must be at least one (for the terminating nul). */ | |
1274 | bool at_least_one = false; | |
1275 | if (srcstr) | |
1276 | { | |
1277 | /* SRCSTR is normally a pointer to string but as a special case | |
1278 | it can be an integer denoting the length of a string. */ | |
1279 | if (POINTER_TYPE_P (TREE_TYPE (srcstr))) | |
1280 | { | |
1281 | if (!check_nul_terminated_array (exp, srcstr, maxread)) | |
81d6cdd3 MS |
1282 | /* Return if the array is not nul-terminated and a warning |
1283 | has been issued. */ | |
2a837de2 | 1284 | return false; |
81d6cdd3 | 1285 | |
2a837de2 MS |
1286 | /* Try to determine the range of lengths the source string |
1287 | refers to. If it can be determined and is less than | |
1288 | the upper bound given by MAXREAD add one to it for | |
1289 | the terminating nul. Otherwise, set it to one for | |
1290 | the same reason, or to MAXREAD as appropriate. */ | |
1291 | c_strlen_data lendata = { }; | |
1292 | get_range_strlen (srcstr, &lendata, /* eltsize = */ 1); | |
1293 | range[0] = lendata.minlen; | |
1294 | range[1] = lendata.maxbound ? lendata.maxbound : lendata.maxlen; | |
1295 | if (range[0] | |
1296 | && TREE_CODE (range[0]) == INTEGER_CST | |
1297 | && TREE_CODE (range[1]) == INTEGER_CST | |
1298 | && (!maxread || TREE_CODE (maxread) == INTEGER_CST)) | |
1299 | { | |
1300 | if (maxread && tree_int_cst_le (maxread, range[0])) | |
1301 | range[0] = range[1] = maxread; | |
1302 | else | |
1303 | range[0] = fold_build2 (PLUS_EXPR, size_type_node, | |
1304 | range[0], size_one_node); | |
1305 | ||
1306 | if (maxread && tree_int_cst_le (maxread, range[1])) | |
1307 | range[1] = maxread; | |
1308 | else if (!integer_all_onesp (range[1])) | |
1309 | range[1] = fold_build2 (PLUS_EXPR, size_type_node, | |
1310 | range[1], size_one_node); | |
1311 | ||
1312 | slen = range[0]; | |
1313 | } | |
1314 | else | |
1315 | { | |
1316 | at_least_one = true; | |
1317 | slen = size_one_node; | |
1318 | } | |
1319 | } | |
1320 | else | |
1321 | slen = srcstr; | |
1322 | } | |
1323 | ||
1324 | if (!dstwrite && !maxread) | |
1325 | { | |
1326 | /* When the only available piece of data is the object size | |
1327 | there is nothing to do. */ | |
1328 | if (!slen) | |
1329 | return true; | |
1330 | ||
1331 | /* Otherwise, when the length of the source sequence is known | |
1332 | (as with strlen), set DSTWRITE to it. */ | |
1333 | if (!range[0]) | |
1334 | dstwrite = slen; | |
1335 | } | |
1336 | ||
1337 | if (!dstsize) | |
1338 | dstsize = maxobjsize; | |
1339 | ||
f9379fcb | 1340 | /* Set RANGE to that of DSTWRITE if non-null, bounded by PAD->DST_BNDRNG |
2a837de2 | 1341 | if valid. */ |
9a27acc3 | 1342 | gimple *stmt = pad ? pad->stmt : nullptr; |
f9379fcb | 1343 | get_size_range (rvals, dstwrite, stmt, range, pad ? pad->dst_bndrng : NULL); |
2a837de2 MS |
1344 | |
1345 | tree func = get_callee_fndecl (exp); | |
1346 | /* Read vs write access by built-ins can be determined from the const | |
1347 | qualifiers on the pointer argument. In the absence of attribute | |
1348 | access, non-const qualified pointer arguments to user-defined | |
1349 | functions are assumed to both read and write the objects. */ | |
1350 | const bool builtin = func ? fndecl_built_in_p (func) : false; | |
1351 | ||
1352 | /* First check the number of bytes to be written against the maximum | |
1353 | object size. */ | |
1354 | if (range[0] | |
1355 | && TREE_CODE (range[0]) == INTEGER_CST | |
1356 | && tree_int_cst_lt (maxobjsize, range[0])) | |
1357 | { | |
81d6cdd3 | 1358 | location_t loc = get_location (exp); |
2a837de2 MS |
1359 | maybe_warn_for_bound (OPT_Wstringop_overflow_, loc, exp, func, range, |
1360 | NULL_TREE, pad); | |
1361 | return false; | |
1362 | } | |
1363 | ||
1364 | /* The number of bytes to write is "exact" if DSTWRITE is non-null, | |
1365 | constant, and in range of unsigned HOST_WIDE_INT. */ | |
1366 | bool exactwrite = dstwrite && tree_fits_uhwi_p (dstwrite); | |
1367 | ||
1368 | /* Next check the number of bytes to be written against the destination | |
1369 | object size. */ | |
1370 | if (range[0] || !exactwrite || integer_all_onesp (dstwrite)) | |
1371 | { | |
1372 | if (range[0] | |
1373 | && TREE_CODE (range[0]) == INTEGER_CST | |
1374 | && ((tree_fits_uhwi_p (dstsize) | |
1375 | && tree_int_cst_lt (dstsize, range[0])) | |
1376 | || (dstwrite | |
1377 | && tree_fits_uhwi_p (dstwrite) | |
1378 | && tree_int_cst_lt (dstwrite, range[0])))) | |
1379 | { | |
1380 | const opt_code opt = OPT_Wstringop_overflow_; | |
1381 | if (warning_suppressed_p (exp, opt) | |
1382 | || (pad && pad->dst.ref | |
1383 | && warning_suppressed_p (pad->dst.ref, opt))) | |
1384 | return false; | |
1385 | ||
81d6cdd3 | 1386 | location_t loc = get_location (exp); |
2a837de2 MS |
1387 | bool warned = false; |
1388 | if (dstwrite == slen && at_least_one) | |
1389 | { | |
1390 | /* This is a call to strcpy with a destination of 0 size | |
1391 | and a source of unknown length. The call will write | |
1392 | at least one byte past the end of the destination. */ | |
1393 | warned = (func | |
1394 | ? warning_at (loc, opt, | |
1395 | "%qD writing %E or more bytes into " | |
1396 | "a region of size %E overflows " | |
1397 | "the destination", | |
1398 | func, range[0], dstsize) | |
1399 | : warning_at (loc, opt, | |
1400 | "writing %E or more bytes into " | |
1401 | "a region of size %E overflows " | |
1402 | "the destination", | |
1403 | range[0], dstsize)); | |
1404 | } | |
1405 | else | |
1406 | { | |
1407 | const bool read | |
1408 | = mode == access_read_only || mode == access_read_write; | |
1409 | const bool write | |
1410 | = mode == access_write_only || mode == access_read_write; | |
1411 | const bool maybe = pad && pad->dst.parmarray; | |
1412 | warned = warn_for_access (loc, func, exp, | |
1413 | OPT_Wstringop_overflow_, | |
1414 | range, dstsize, | |
1415 | write, read && !builtin, maybe); | |
1416 | } | |
1417 | ||
1418 | if (warned) | |
1419 | { | |
1420 | suppress_warning (exp, OPT_Wstringop_overflow_); | |
1421 | if (pad) | |
1422 | pad->dst.inform_access (pad->mode); | |
1423 | } | |
1424 | ||
1425 | /* Return error when an overflow has been detected. */ | |
1426 | return false; | |
1427 | } | |
1428 | } | |
1429 | ||
1430 | /* Check the maximum length of the source sequence against the size | |
1431 | of the destination object if known, or against the maximum size | |
1432 | of an object. */ | |
1433 | if (maxread) | |
1434 | { | |
f9379fcb | 1435 | /* Set RANGE to that of MAXREAD, bounded by PAD->SRC_BNDRNG if |
2a837de2 | 1436 | PAD is nonnull and BNDRNG is valid. */ |
f9379fcb | 1437 | get_size_range (rvals, maxread, stmt, range, pad ? pad->src_bndrng : NULL); |
2a837de2 | 1438 | |
81d6cdd3 | 1439 | location_t loc = get_location (exp); |
2a837de2 MS |
1440 | tree size = dstsize; |
1441 | if (pad && pad->mode == access_read_only) | |
820f0940 | 1442 | size = wide_int_to_tree (sizetype, pad->src.size_remaining ()); |
2a837de2 MS |
1443 | |
1444 | if (range[0] && maxread && tree_fits_uhwi_p (size)) | |
1445 | { | |
1446 | if (tree_int_cst_lt (maxobjsize, range[0])) | |
1447 | { | |
1448 | maybe_warn_for_bound (OPT_Wstringop_overread, loc, exp, func, | |
1449 | range, size, pad); | |
1450 | return false; | |
1451 | } | |
1452 | ||
1453 | if (size != maxobjsize && tree_int_cst_lt (size, range[0])) | |
1454 | { | |
1455 | opt_code opt = (dstwrite || mode != access_read_only | |
1456 | ? OPT_Wstringop_overflow_ | |
1457 | : OPT_Wstringop_overread); | |
1458 | maybe_warn_for_bound (opt, loc, exp, func, range, size, pad); | |
1459 | return false; | |
1460 | } | |
1461 | } | |
1462 | ||
1463 | maybe_warn_nonstring_arg (func, exp); | |
1464 | } | |
1465 | ||
1466 | /* Check for reading past the end of SRC. */ | |
1467 | bool overread = (slen | |
1468 | && slen == srcstr | |
1469 | && dstwrite | |
1470 | && range[0] | |
1471 | && TREE_CODE (slen) == INTEGER_CST | |
1472 | && tree_int_cst_lt (slen, range[0])); | |
1473 | /* If none is determined try to get a better answer based on the details | |
1474 | in PAD. */ | |
1475 | if (!overread | |
1476 | && pad | |
1477 | && pad->src.sizrng[1] >= 0 | |
1478 | && pad->src.offrng[0] >= 0 | |
1479 | && (pad->src.offrng[1] < 0 | |
1480 | || pad->src.offrng[0] <= pad->src.offrng[1])) | |
1481 | { | |
f9379fcb | 1482 | /* Set RANGE to that of MAXREAD, bounded by PAD->SRC_BNDRNG if |
2a837de2 | 1483 | PAD is nonnull and BNDRNG is valid. */ |
f9379fcb | 1484 | get_size_range (rvals, maxread, stmt, range, pad ? pad->src_bndrng : NULL); |
2a837de2 | 1485 | /* Set OVERREAD for reads starting just past the end of an object. */ |
f9379fcb MS |
1486 | overread = pad->src.sizrng[1] - pad->src.offrng[0] < pad->src_bndrng[0]; |
1487 | range[0] = wide_int_to_tree (sizetype, pad->src_bndrng[0]); | |
2a837de2 MS |
1488 | slen = size_zero_node; |
1489 | } | |
1490 | ||
1491 | if (overread) | |
1492 | { | |
1493 | const opt_code opt = OPT_Wstringop_overread; | |
1494 | if (warning_suppressed_p (exp, opt) | |
1495 | || (srcstr && warning_suppressed_p (srcstr, opt)) | |
1496 | || (pad && pad->src.ref | |
1497 | && warning_suppressed_p (pad->src.ref, opt))) | |
1498 | return false; | |
1499 | ||
81d6cdd3 | 1500 | location_t loc = get_location (exp); |
2a837de2 MS |
1501 | const bool read |
1502 | = mode == access_read_only || mode == access_read_write; | |
1503 | const bool maybe = pad && pad->dst.parmarray; | |
1504 | if (warn_for_access (loc, func, exp, opt, range, slen, false, read, | |
1505 | maybe)) | |
1506 | { | |
1507 | suppress_warning (exp, opt); | |
1508 | if (pad) | |
1509 | pad->src.inform_access (access_read_only); | |
1510 | } | |
1511 | return false; | |
1512 | } | |
1513 | ||
1514 | return true; | |
1515 | } | |
1516 | ||
9a27acc3 | 1517 | static bool |
81d6cdd3 MS |
1518 | check_access (gimple *stmt, tree dstwrite, |
1519 | tree maxread, tree srcstr, tree dstsize, | |
9a27acc3 MS |
1520 | access_mode mode, const access_data *pad, |
1521 | range_query *rvals) | |
81d6cdd3 | 1522 | { |
9a27acc3 MS |
1523 | return check_access<gimple *> (stmt, dstwrite, maxread, srcstr, dstsize, |
1524 | mode, pad, rvals); | |
81d6cdd3 MS |
1525 | } |
1526 | ||
1527 | bool | |
1528 | check_access (tree expr, tree dstwrite, | |
1529 | tree maxread, tree srcstr, tree dstsize, | |
1530 | access_mode mode, const access_data *pad /* = NULL */) | |
1531 | { | |
9a27acc3 MS |
1532 | return check_access<tree> (expr, dstwrite, maxread, srcstr, dstsize, |
1533 | mode, pad, nullptr); | |
81d6cdd3 MS |
1534 | } |
1535 | ||
2a837de2 MS |
1536 | /* Return true if STMT is a call to an allocation function. Unless |
1537 | ALL_ALLOC is set, consider only functions that return dynmamically | |
1538 | allocated objects. Otherwise return true even for all forms of | |
1539 | alloca (including VLA). */ | |
1540 | ||
1541 | static bool | |
1542 | fndecl_alloc_p (tree fndecl, bool all_alloc) | |
1543 | { | |
1544 | if (!fndecl) | |
1545 | return false; | |
1546 | ||
1547 | /* A call to operator new isn't recognized as one to a built-in. */ | |
1548 | if (DECL_IS_OPERATOR_NEW_P (fndecl)) | |
1549 | return true; | |
1550 | ||
1551 | if (fndecl_built_in_p (fndecl, BUILT_IN_NORMAL)) | |
1552 | { | |
1553 | switch (DECL_FUNCTION_CODE (fndecl)) | |
1554 | { | |
1555 | case BUILT_IN_ALLOCA: | |
1556 | case BUILT_IN_ALLOCA_WITH_ALIGN: | |
1557 | return all_alloc; | |
1558 | case BUILT_IN_ALIGNED_ALLOC: | |
1559 | case BUILT_IN_CALLOC: | |
1560 | case BUILT_IN_GOMP_ALLOC: | |
1561 | case BUILT_IN_MALLOC: | |
1562 | case BUILT_IN_REALLOC: | |
1563 | case BUILT_IN_STRDUP: | |
1564 | case BUILT_IN_STRNDUP: | |
1565 | return true; | |
1566 | default: | |
1567 | break; | |
1568 | } | |
1569 | } | |
1570 | ||
1571 | /* A function is considered an allocation function if it's declared | |
1572 | with attribute malloc with an argument naming its associated | |
1573 | deallocation function. */ | |
1574 | tree attrs = DECL_ATTRIBUTES (fndecl); | |
1575 | if (!attrs) | |
1576 | return false; | |
1577 | ||
1578 | for (tree allocs = attrs; | |
1579 | (allocs = lookup_attribute ("malloc", allocs)); | |
1580 | allocs = TREE_CHAIN (allocs)) | |
1581 | { | |
1582 | tree args = TREE_VALUE (allocs); | |
1583 | if (!args) | |
1584 | continue; | |
1585 | ||
1586 | if (TREE_VALUE (args)) | |
1587 | return true; | |
1588 | } | |
1589 | ||
1590 | return false; | |
1591 | } | |
1592 | ||
1593 | /* Return true if STMT is a call to an allocation function. A wrapper | |
1594 | around fndecl_alloc_p. */ | |
1595 | ||
1596 | static bool | |
1597 | gimple_call_alloc_p (gimple *stmt, bool all_alloc = false) | |
1598 | { | |
1599 | return fndecl_alloc_p (gimple_call_fndecl (stmt), all_alloc); | |
1600 | } | |
1601 | ||
1602 | /* Return true if DELC doesn't refer to an operator delete that's | |
1603 | suitable to call with a pointer returned from the operator new | |
1604 | described by NEWC. */ | |
1605 | ||
1606 | static bool | |
1607 | new_delete_mismatch_p (const demangle_component &newc, | |
1608 | const demangle_component &delc) | |
1609 | { | |
1610 | if (newc.type != delc.type) | |
1611 | return true; | |
1612 | ||
1613 | switch (newc.type) | |
1614 | { | |
1615 | case DEMANGLE_COMPONENT_NAME: | |
1616 | { | |
1617 | int len = newc.u.s_name.len; | |
1618 | const char *news = newc.u.s_name.s; | |
1619 | const char *dels = delc.u.s_name.s; | |
1620 | if (len != delc.u.s_name.len || memcmp (news, dels, len)) | |
1621 | return true; | |
1622 | ||
1623 | if (news[len] == 'n') | |
1624 | { | |
1625 | if (news[len + 1] == 'a') | |
1626 | return dels[len] != 'd' || dels[len + 1] != 'a'; | |
1627 | if (news[len + 1] == 'w') | |
1628 | return dels[len] != 'd' || dels[len + 1] != 'l'; | |
1629 | } | |
1630 | return false; | |
1631 | } | |
1632 | ||
1633 | case DEMANGLE_COMPONENT_OPERATOR: | |
1634 | /* Operator mismatches are handled above. */ | |
1635 | return false; | |
1636 | ||
1637 | case DEMANGLE_COMPONENT_EXTENDED_OPERATOR: | |
1638 | if (newc.u.s_extended_operator.args != delc.u.s_extended_operator.args) | |
1639 | return true; | |
1640 | return new_delete_mismatch_p (*newc.u.s_extended_operator.name, | |
1641 | *delc.u.s_extended_operator.name); | |
1642 | ||
1643 | case DEMANGLE_COMPONENT_FIXED_TYPE: | |
1644 | if (newc.u.s_fixed.accum != delc.u.s_fixed.accum | |
1645 | || newc.u.s_fixed.sat != delc.u.s_fixed.sat) | |
1646 | return true; | |
1647 | return new_delete_mismatch_p (*newc.u.s_fixed.length, | |
1648 | *delc.u.s_fixed.length); | |
1649 | ||
1650 | case DEMANGLE_COMPONENT_CTOR: | |
1651 | if (newc.u.s_ctor.kind != delc.u.s_ctor.kind) | |
1652 | return true; | |
1653 | return new_delete_mismatch_p (*newc.u.s_ctor.name, | |
1654 | *delc.u.s_ctor.name); | |
1655 | ||
1656 | case DEMANGLE_COMPONENT_DTOR: | |
1657 | if (newc.u.s_dtor.kind != delc.u.s_dtor.kind) | |
1658 | return true; | |
1659 | return new_delete_mismatch_p (*newc.u.s_dtor.name, | |
1660 | *delc.u.s_dtor.name); | |
1661 | ||
1662 | case DEMANGLE_COMPONENT_BUILTIN_TYPE: | |
1663 | { | |
1664 | /* The demangler API provides no better way to compare built-in | |
1665 | types except to by comparing their demangled names. */ | |
1666 | size_t nsz, dsz; | |
1667 | demangle_component *pnc = const_cast<demangle_component *>(&newc); | |
1668 | demangle_component *pdc = const_cast<demangle_component *>(&delc); | |
1669 | char *nts = cplus_demangle_print (0, pnc, 16, &nsz); | |
1670 | char *dts = cplus_demangle_print (0, pdc, 16, &dsz); | |
1671 | if (!nts != !dts) | |
1672 | return true; | |
1673 | bool mismatch = strcmp (nts, dts); | |
1674 | free (nts); | |
1675 | free (dts); | |
1676 | return mismatch; | |
1677 | } | |
1678 | ||
1679 | case DEMANGLE_COMPONENT_SUB_STD: | |
1680 | if (newc.u.s_string.len != delc.u.s_string.len) | |
1681 | return true; | |
1682 | return memcmp (newc.u.s_string.string, delc.u.s_string.string, | |
1683 | newc.u.s_string.len); | |
1684 | ||
1685 | case DEMANGLE_COMPONENT_FUNCTION_PARAM: | |
1686 | case DEMANGLE_COMPONENT_TEMPLATE_PARAM: | |
1687 | return newc.u.s_number.number != delc.u.s_number.number; | |
1688 | ||
1689 | case DEMANGLE_COMPONENT_CHARACTER: | |
1690 | return newc.u.s_character.character != delc.u.s_character.character; | |
1691 | ||
1692 | case DEMANGLE_COMPONENT_DEFAULT_ARG: | |
1693 | case DEMANGLE_COMPONENT_LAMBDA: | |
1694 | if (newc.u.s_unary_num.num != delc.u.s_unary_num.num) | |
1695 | return true; | |
1696 | return new_delete_mismatch_p (*newc.u.s_unary_num.sub, | |
1697 | *delc.u.s_unary_num.sub); | |
1698 | default: | |
1699 | break; | |
1700 | } | |
1701 | ||
1702 | if (!newc.u.s_binary.left != !delc.u.s_binary.left) | |
1703 | return true; | |
1704 | ||
1705 | if (!newc.u.s_binary.left) | |
1706 | return false; | |
1707 | ||
1708 | if (new_delete_mismatch_p (*newc.u.s_binary.left, *delc.u.s_binary.left) | |
1709 | || !newc.u.s_binary.right != !delc.u.s_binary.right) | |
1710 | return true; | |
1711 | ||
1712 | if (newc.u.s_binary.right) | |
1713 | return new_delete_mismatch_p (*newc.u.s_binary.right, | |
1714 | *delc.u.s_binary.right); | |
1715 | return false; | |
1716 | } | |
1717 | ||
1718 | /* Return true if DELETE_DECL is an operator delete that's not suitable | |
1719 | to call with a pointer returned fron NEW_DECL. */ | |
1720 | ||
1721 | static bool | |
1722 | new_delete_mismatch_p (tree new_decl, tree delete_decl) | |
1723 | { | |
1724 | tree new_name = DECL_ASSEMBLER_NAME (new_decl); | |
1725 | tree delete_name = DECL_ASSEMBLER_NAME (delete_decl); | |
1726 | ||
1727 | /* valid_new_delete_pair_p() returns a conservative result (currently | |
1728 | it only handles global operators). A true result is reliable but | |
96194a07 MS |
1729 | a false result doesn't necessarily mean the operators don't match |
1730 | unless CERTAIN is set. */ | |
1731 | bool certain; | |
1732 | if (valid_new_delete_pair_p (new_name, delete_name, &certain)) | |
2a837de2 | 1733 | return false; |
96194a07 MS |
1734 | /* CERTAIN is set when the negative result is certain. */ |
1735 | if (certain) | |
1736 | return true; | |
2a837de2 MS |
1737 | |
1738 | /* For anything not handled by valid_new_delete_pair_p() such as member | |
1739 | operators compare the individual demangled components of the mangled | |
1740 | name. */ | |
1741 | const char *new_str = IDENTIFIER_POINTER (new_name); | |
1742 | const char *del_str = IDENTIFIER_POINTER (delete_name); | |
1743 | ||
1744 | void *np = NULL, *dp = NULL; | |
1745 | demangle_component *ndc = cplus_demangle_v3_components (new_str, 0, &np); | |
1746 | demangle_component *ddc = cplus_demangle_v3_components (del_str, 0, &dp); | |
1747 | bool mismatch = new_delete_mismatch_p (*ndc, *ddc); | |
1748 | free (np); | |
1749 | free (dp); | |
1750 | return mismatch; | |
1751 | } | |
1752 | ||
1753 | /* ALLOC_DECL and DEALLOC_DECL are pair of allocation and deallocation | |
1754 | functions. Return true if the latter is suitable to deallocate objects | |
1755 | allocated by calls to the former. */ | |
1756 | ||
1757 | static bool | |
1758 | matching_alloc_calls_p (tree alloc_decl, tree dealloc_decl) | |
1759 | { | |
1760 | /* Set to alloc_kind_t::builtin if ALLOC_DECL is associated with | |
1761 | a built-in deallocator. */ | |
1762 | enum class alloc_kind_t { none, builtin, user } | |
1763 | alloc_dealloc_kind = alloc_kind_t::none; | |
1764 | ||
1765 | if (DECL_IS_OPERATOR_NEW_P (alloc_decl)) | |
1766 | { | |
1767 | if (DECL_IS_OPERATOR_DELETE_P (dealloc_decl)) | |
1768 | /* Return true iff both functions are of the same array or | |
1769 | singleton form and false otherwise. */ | |
1770 | return !new_delete_mismatch_p (alloc_decl, dealloc_decl); | |
1771 | ||
1772 | /* Return false for deallocation functions that are known not | |
1773 | to match. */ | |
1774 | if (fndecl_built_in_p (dealloc_decl, BUILT_IN_FREE) | |
1775 | || fndecl_built_in_p (dealloc_decl, BUILT_IN_REALLOC)) | |
1776 | return false; | |
1777 | /* Otherwise proceed below to check the deallocation function's | |
1778 | "*dealloc" attributes to look for one that mentions this operator | |
1779 | new. */ | |
1780 | } | |
1781 | else if (fndecl_built_in_p (alloc_decl, BUILT_IN_NORMAL)) | |
1782 | { | |
1783 | switch (DECL_FUNCTION_CODE (alloc_decl)) | |
1784 | { | |
1785 | case BUILT_IN_ALLOCA: | |
1786 | case BUILT_IN_ALLOCA_WITH_ALIGN: | |
1787 | return false; | |
1788 | ||
1789 | case BUILT_IN_ALIGNED_ALLOC: | |
1790 | case BUILT_IN_CALLOC: | |
1791 | case BUILT_IN_GOMP_ALLOC: | |
1792 | case BUILT_IN_MALLOC: | |
1793 | case BUILT_IN_REALLOC: | |
1794 | case BUILT_IN_STRDUP: | |
1795 | case BUILT_IN_STRNDUP: | |
1796 | if (DECL_IS_OPERATOR_DELETE_P (dealloc_decl)) | |
1797 | return false; | |
1798 | ||
1799 | if (fndecl_built_in_p (dealloc_decl, BUILT_IN_FREE) | |
1800 | || fndecl_built_in_p (dealloc_decl, BUILT_IN_REALLOC)) | |
1801 | return true; | |
1802 | ||
1803 | alloc_dealloc_kind = alloc_kind_t::builtin; | |
1804 | break; | |
1805 | ||
1806 | default: | |
1807 | break; | |
1808 | } | |
1809 | } | |
1810 | ||
1811 | /* Set if DEALLOC_DECL both allocates and deallocates. */ | |
1812 | alloc_kind_t realloc_kind = alloc_kind_t::none; | |
1813 | ||
1814 | if (fndecl_built_in_p (dealloc_decl, BUILT_IN_NORMAL)) | |
1815 | { | |
1816 | built_in_function dealloc_code = DECL_FUNCTION_CODE (dealloc_decl); | |
1817 | if (dealloc_code == BUILT_IN_REALLOC) | |
1818 | realloc_kind = alloc_kind_t::builtin; | |
1819 | ||
1820 | for (tree amats = DECL_ATTRIBUTES (alloc_decl); | |
1821 | (amats = lookup_attribute ("malloc", amats)); | |
1822 | amats = TREE_CHAIN (amats)) | |
1823 | { | |
1824 | tree args = TREE_VALUE (amats); | |
1825 | if (!args) | |
1826 | continue; | |
1827 | ||
1828 | tree fndecl = TREE_VALUE (args); | |
1829 | if (!fndecl || !DECL_P (fndecl)) | |
1830 | continue; | |
1831 | ||
1832 | if (fndecl_built_in_p (fndecl, BUILT_IN_NORMAL) | |
1833 | && dealloc_code == DECL_FUNCTION_CODE (fndecl)) | |
1834 | return true; | |
1835 | } | |
1836 | } | |
1837 | ||
1838 | const bool alloc_builtin = fndecl_built_in_p (alloc_decl, BUILT_IN_NORMAL); | |
1839 | alloc_kind_t realloc_dealloc_kind = alloc_kind_t::none; | |
1840 | ||
1841 | /* If DEALLOC_DECL has an internal "*dealloc" attribute scan the list | |
1842 | of its associated allocation functions for ALLOC_DECL. | |
1843 | If the corresponding ALLOC_DECL is found they're a matching pair, | |
1844 | otherwise they're not. | |
1845 | With DDATS set to the Deallocator's *Dealloc ATtributes... */ | |
1846 | for (tree ddats = DECL_ATTRIBUTES (dealloc_decl); | |
1847 | (ddats = lookup_attribute ("*dealloc", ddats)); | |
1848 | ddats = TREE_CHAIN (ddats)) | |
1849 | { | |
1850 | tree args = TREE_VALUE (ddats); | |
1851 | if (!args) | |
1852 | continue; | |
1853 | ||
1854 | tree alloc = TREE_VALUE (args); | |
1855 | if (!alloc) | |
1856 | continue; | |
1857 | ||
1858 | if (alloc == DECL_NAME (dealloc_decl)) | |
1859 | realloc_kind = alloc_kind_t::user; | |
1860 | ||
1861 | if (DECL_P (alloc)) | |
1862 | { | |
1863 | gcc_checking_assert (fndecl_built_in_p (alloc, BUILT_IN_NORMAL)); | |
1864 | ||
1865 | switch (DECL_FUNCTION_CODE (alloc)) | |
1866 | { | |
1867 | case BUILT_IN_ALIGNED_ALLOC: | |
1868 | case BUILT_IN_CALLOC: | |
1869 | case BUILT_IN_GOMP_ALLOC: | |
1870 | case BUILT_IN_MALLOC: | |
1871 | case BUILT_IN_REALLOC: | |
1872 | case BUILT_IN_STRDUP: | |
1873 | case BUILT_IN_STRNDUP: | |
1874 | realloc_dealloc_kind = alloc_kind_t::builtin; | |
1875 | break; | |
1876 | default: | |
1877 | break; | |
1878 | } | |
1879 | ||
1880 | if (!alloc_builtin) | |
1881 | continue; | |
1882 | ||
1883 | if (DECL_FUNCTION_CODE (alloc) != DECL_FUNCTION_CODE (alloc_decl)) | |
1884 | continue; | |
1885 | ||
1886 | return true; | |
1887 | } | |
1888 | ||
1889 | if (alloc == DECL_NAME (alloc_decl)) | |
1890 | return true; | |
1891 | } | |
1892 | ||
1893 | if (realloc_kind == alloc_kind_t::none) | |
1894 | return false; | |
1895 | ||
1896 | hash_set<tree> common_deallocs; | |
1897 | /* Special handling for deallocators. Iterate over both the allocator's | |
1898 | and the reallocator's associated deallocator functions looking for | |
1899 | the first one in common. If one is found, the de/reallocator is | |
1900 | a match for the allocator even though the latter isn't directly | |
1901 | associated with the former. This simplifies declarations in system | |
1902 | headers. | |
1903 | With AMATS set to the Allocator's Malloc ATtributes, | |
1904 | and RMATS set to Reallocator's Malloc ATtributes... */ | |
1905 | for (tree amats = DECL_ATTRIBUTES (alloc_decl), | |
1906 | rmats = DECL_ATTRIBUTES (dealloc_decl); | |
1907 | (amats = lookup_attribute ("malloc", amats)) | |
1908 | || (rmats = lookup_attribute ("malloc", rmats)); | |
1909 | amats = amats ? TREE_CHAIN (amats) : NULL_TREE, | |
1910 | rmats = rmats ? TREE_CHAIN (rmats) : NULL_TREE) | |
1911 | { | |
1912 | if (tree args = amats ? TREE_VALUE (amats) : NULL_TREE) | |
1913 | if (tree adealloc = TREE_VALUE (args)) | |
1914 | { | |
1915 | if (DECL_P (adealloc) | |
1916 | && fndecl_built_in_p (adealloc, BUILT_IN_NORMAL)) | |
1917 | { | |
1918 | built_in_function fncode = DECL_FUNCTION_CODE (adealloc); | |
1919 | if (fncode == BUILT_IN_FREE || fncode == BUILT_IN_REALLOC) | |
1920 | { | |
1921 | if (realloc_kind == alloc_kind_t::builtin) | |
1922 | return true; | |
1923 | alloc_dealloc_kind = alloc_kind_t::builtin; | |
1924 | } | |
1925 | continue; | |
1926 | } | |
1927 | ||
1928 | common_deallocs.add (adealloc); | |
1929 | } | |
1930 | ||
1931 | if (tree args = rmats ? TREE_VALUE (rmats) : NULL_TREE) | |
1932 | if (tree ddealloc = TREE_VALUE (args)) | |
1933 | { | |
1934 | if (DECL_P (ddealloc) | |
1935 | && fndecl_built_in_p (ddealloc, BUILT_IN_NORMAL)) | |
1936 | { | |
1937 | built_in_function fncode = DECL_FUNCTION_CODE (ddealloc); | |
1938 | if (fncode == BUILT_IN_FREE || fncode == BUILT_IN_REALLOC) | |
1939 | { | |
1940 | if (alloc_dealloc_kind == alloc_kind_t::builtin) | |
1941 | return true; | |
1942 | realloc_dealloc_kind = alloc_kind_t::builtin; | |
1943 | } | |
1944 | continue; | |
1945 | } | |
1946 | ||
1947 | if (common_deallocs.add (ddealloc)) | |
1948 | return true; | |
1949 | } | |
1950 | } | |
1951 | ||
1952 | /* Succeed only if ALLOC_DECL and the reallocator DEALLOC_DECL share | |
1953 | a built-in deallocator. */ | |
1954 | return (alloc_dealloc_kind == alloc_kind_t::builtin | |
1955 | && realloc_dealloc_kind == alloc_kind_t::builtin); | |
1956 | } | |
1957 | ||
1958 | /* Return true if DEALLOC_DECL is a function suitable to deallocate | |
1959 | objectes allocated by the ALLOC call. */ | |
1960 | ||
1961 | static bool | |
1962 | matching_alloc_calls_p (gimple *alloc, tree dealloc_decl) | |
1963 | { | |
1964 | tree alloc_decl = gimple_call_fndecl (alloc); | |
1965 | if (!alloc_decl) | |
1966 | return true; | |
1967 | ||
1968 | return matching_alloc_calls_p (alloc_decl, dealloc_decl); | |
1969 | } | |
1970 | ||
1971 | /* Diagnose a call EXP to deallocate a pointer referenced by AREF if it | |
1972 | includes a nonzero offset. Such a pointer cannot refer to the beginning | |
1973 | of an allocated object. A negative offset may refer to it only if | |
1974 | the target pointer is unknown. */ | |
1975 | ||
1976 | static bool | |
1977 | warn_dealloc_offset (location_t loc, gimple *call, const access_ref &aref) | |
1978 | { | |
1979 | if (aref.deref || aref.offrng[0] <= 0 || aref.offrng[1] <= 0) | |
1980 | return false; | |
1981 | ||
1982 | tree dealloc_decl = gimple_call_fndecl (call); | |
1983 | if (!dealloc_decl) | |
1984 | return false; | |
1985 | ||
1986 | if (DECL_IS_OPERATOR_DELETE_P (dealloc_decl) | |
1987 | && !DECL_IS_REPLACEABLE_OPERATOR (dealloc_decl)) | |
1988 | { | |
1989 | /* A call to a user-defined operator delete with a pointer plus offset | |
1990 | may be valid if it's returned from an unknown function (i.e., one | |
1991 | that's not operator new). */ | |
1992 | if (TREE_CODE (aref.ref) == SSA_NAME) | |
1993 | { | |
1994 | gimple *def_stmt = SSA_NAME_DEF_STMT (aref.ref); | |
1995 | if (is_gimple_call (def_stmt)) | |
1996 | { | |
1997 | tree alloc_decl = gimple_call_fndecl (def_stmt); | |
1998 | if (!alloc_decl || !DECL_IS_OPERATOR_NEW_P (alloc_decl)) | |
1999 | return false; | |
2000 | } | |
2001 | } | |
2002 | } | |
2003 | ||
2004 | char offstr[80]; | |
2005 | offstr[0] = '\0'; | |
2006 | if (wi::fits_shwi_p (aref.offrng[0])) | |
2007 | { | |
2008 | if (aref.offrng[0] == aref.offrng[1] | |
2009 | || !wi::fits_shwi_p (aref.offrng[1])) | |
2010 | sprintf (offstr, " %lli", | |
2011 | (long long)aref.offrng[0].to_shwi ()); | |
2012 | else | |
2013 | sprintf (offstr, " [%lli, %lli]", | |
2014 | (long long)aref.offrng[0].to_shwi (), | |
2015 | (long long)aref.offrng[1].to_shwi ()); | |
2016 | } | |
2017 | ||
2018 | if (!warning_at (loc, OPT_Wfree_nonheap_object, | |
2019 | "%qD called on pointer %qE with nonzero offset%s", | |
2020 | dealloc_decl, aref.ref, offstr)) | |
2021 | return false; | |
2022 | ||
2023 | if (DECL_P (aref.ref)) | |
81d6cdd3 | 2024 | inform (get_location (aref.ref), "declared here"); |
2a837de2 MS |
2025 | else if (TREE_CODE (aref.ref) == SSA_NAME) |
2026 | { | |
2027 | gimple *def_stmt = SSA_NAME_DEF_STMT (aref.ref); | |
2028 | if (is_gimple_call (def_stmt)) | |
2029 | { | |
81d6cdd3 | 2030 | location_t def_loc = get_location (def_stmt); |
2a837de2 MS |
2031 | tree alloc_decl = gimple_call_fndecl (def_stmt); |
2032 | if (alloc_decl) | |
2033 | inform (def_loc, | |
2034 | "returned from %qD", alloc_decl); | |
2035 | else if (tree alloc_fntype = gimple_call_fntype (def_stmt)) | |
2036 | inform (def_loc, | |
2037 | "returned from %qT", alloc_fntype); | |
2038 | else | |
2039 | inform (def_loc, "obtained here"); | |
2040 | } | |
2041 | } | |
2042 | ||
2043 | return true; | |
2044 | } | |
2045 | ||
2a837de2 MS |
2046 | namespace { |
2047 | ||
2048 | const pass_data pass_data_waccess = { | |
2049 | GIMPLE_PASS, | |
2050 | "waccess", | |
2051 | OPTGROUP_NONE, | |
2052 | TV_NONE, | |
2053 | PROP_cfg, /* properties_required */ | |
2054 | 0, /* properties_provided */ | |
2055 | 0, /* properties_destroyed */ | |
2056 | 0, /* properties_start */ | |
2057 | 0, /* properties_finish */ | |
2058 | }; | |
2059 | ||
2060 | /* Pass to detect invalid accesses. */ | |
2061 | class pass_waccess : public gimple_opt_pass | |
2062 | { | |
2063 | public: | |
b48d4e68 MS |
2064 | pass_waccess (gcc::context *); |
2065 | ||
2066 | ~pass_waccess (); | |
2a837de2 MS |
2067 | |
2068 | opt_pass *clone () { return new pass_waccess (m_ctxt); } | |
2069 | ||
2070 | virtual bool gate (function *); | |
2071 | virtual unsigned int execute (function *); | |
2072 | ||
ece28da9 MS |
2073 | private: |
2074 | /* Not copyable or assignable. */ | |
2075 | pass_waccess (pass_waccess &) = delete; | |
2076 | void operator= (pass_waccess &) = delete; | |
2077 | ||
88b504b7 MS |
2078 | /* Check a call to an atomic built-in function. */ |
2079 | bool check_atomic_builtin (gcall *); | |
2080 | ||
81d6cdd3 MS |
2081 | /* Check a call to a built-in function. */ |
2082 | bool check_builtin (gcall *); | |
2083 | ||
b48d4e68 MS |
2084 | /* Check a call to an ordinary function. */ |
2085 | bool check_call (gcall *); | |
2086 | ||
81d6cdd3 | 2087 | /* Check statements in a basic block. */ |
2a837de2 | 2088 | void check (basic_block); |
81d6cdd3 MS |
2089 | |
2090 | /* Check a call to a function. */ | |
ece28da9 | 2091 | void check (gcall *); |
2a837de2 | 2092 | |
ece28da9 MS |
2093 | /* Check a call to the named built-in function. */ |
2094 | void check_alloca (gcall *); | |
2095 | void check_alloc_size_call (gcall *); | |
2096 | void check_strcat (gcall *); | |
2097 | void check_strncat (gcall *); | |
2098 | void check_stxcpy (gcall *); | |
2099 | void check_stxncpy (gcall *); | |
2100 | void check_strncmp (gcall *); | |
2101 | void check_memop_access (gimple *, tree, tree, tree); | |
9a27acc3 | 2102 | void check_read_access (gimple *, tree, tree = NULL_TREE, int = 1); |
ece28da9 MS |
2103 | |
2104 | void maybe_check_dealloc_call (gcall *); | |
2105 | void maybe_check_access_sizes (rdwr_map *, tree, tree, gimple *); | |
b48d4e68 MS |
2106 | |
2107 | /* A pointer_query object and its cache to store information about | |
2108 | pointers and their targets in. */ | |
ece28da9 MS |
2109 | pointer_query m_ptr_qry; |
2110 | pointer_query::cache_type m_var_cache; | |
2a837de2 MS |
2111 | }; |
2112 | ||
b48d4e68 MS |
2113 | /* Construct the pass. */ |
2114 | ||
2115 | pass_waccess::pass_waccess (gcc::context *ctxt) | |
2116 | : gimple_opt_pass (pass_data_waccess, ctxt), | |
ece28da9 MS |
2117 | m_ptr_qry (NULL, &m_var_cache), |
2118 | m_var_cache () | |
b48d4e68 MS |
2119 | { |
2120 | } | |
2121 | ||
2122 | /* Release pointer_query cache. */ | |
2123 | ||
2124 | pass_waccess::~pass_waccess () | |
2125 | { | |
ece28da9 | 2126 | m_ptr_qry.flush_cache (); |
b48d4e68 MS |
2127 | } |
2128 | ||
2a837de2 MS |
2129 | /* Return true when any checks performed by the pass are enabled. */ |
2130 | ||
2131 | bool | |
2132 | pass_waccess::gate (function *) | |
2133 | { | |
2134 | return (warn_free_nonheap_object | |
2135 | || warn_mismatched_alloc | |
2136 | || warn_mismatched_new_delete); | |
2137 | } | |
2138 | ||
b48d4e68 MS |
2139 | /* Initialize ALLOC_OBJECT_SIZE_LIMIT based on the -Walloc-size-larger-than= |
2140 | setting if the option is specified, or to the maximum object size if it | |
2141 | is not. Return the initialized value. */ | |
2142 | ||
2143 | static tree | |
2144 | alloc_max_size (void) | |
2145 | { | |
2146 | HOST_WIDE_INT limit = warn_alloc_size_limit; | |
2147 | if (limit == HOST_WIDE_INT_MAX) | |
2148 | limit = tree_to_shwi (TYPE_MAX_VALUE (ptrdiff_type_node)); | |
2149 | ||
2150 | return build_int_cst (size_type_node, limit); | |
2151 | } | |
2152 | ||
2153 | /* Diagnose a call EXP to function FN decorated with attribute alloc_size | |
2154 | whose argument numbers given by IDX with values given by ARGS exceed | |
2155 | the maximum object size or cause an unsigned oveflow (wrapping) when | |
2156 | multiplied. FN is null when EXP is a call via a function pointer. | |
2157 | When ARGS[0] is null the function does nothing. ARGS[1] may be null | |
2158 | for functions like malloc, and non-null for those like calloc that | |
2159 | are decorated with a two-argument attribute alloc_size. */ | |
2160 | ||
2161 | void | |
2162 | maybe_warn_alloc_args_overflow (gimple *stmt, const tree args[2], | |
2163 | const int idx[2]) | |
2164 | { | |
2165 | /* The range each of the (up to) two arguments is known to be in. */ | |
2166 | tree argrange[2][2] = { { NULL_TREE, NULL_TREE }, { NULL_TREE, NULL_TREE } }; | |
2167 | ||
2168 | /* Maximum object size set by -Walloc-size-larger-than= or SIZE_MAX / 2. */ | |
2169 | tree maxobjsize = alloc_max_size (); | |
2170 | ||
2171 | location_t loc = get_location (stmt); | |
2172 | ||
2173 | tree fn = gimple_call_fndecl (stmt); | |
2174 | tree fntype = fn ? TREE_TYPE (fn) : gimple_call_fntype (stmt); | |
2175 | bool warned = false; | |
2176 | ||
2177 | /* Validate each argument individually. */ | |
2178 | for (unsigned i = 0; i != 2 && args[i]; ++i) | |
2179 | { | |
2180 | if (TREE_CODE (args[i]) == INTEGER_CST) | |
2181 | { | |
2182 | argrange[i][0] = args[i]; | |
2183 | argrange[i][1] = args[i]; | |
2184 | ||
2185 | if (tree_int_cst_lt (args[i], integer_zero_node)) | |
2186 | { | |
2187 | warned = warning_at (loc, OPT_Walloc_size_larger_than_, | |
2188 | "argument %i value %qE is negative", | |
2189 | idx[i] + 1, args[i]); | |
2190 | } | |
2191 | else if (integer_zerop (args[i])) | |
2192 | { | |
2193 | /* Avoid issuing -Walloc-zero for allocation functions other | |
2194 | than __builtin_alloca that are declared with attribute | |
2195 | returns_nonnull because there's no portability risk. This | |
2196 | avoids warning for such calls to libiberty's xmalloc and | |
2197 | friends. | |
2198 | Also avoid issuing the warning for calls to function named | |
2199 | "alloca". */ | |
2200 | if (fn && fndecl_built_in_p (fn, BUILT_IN_ALLOCA) | |
2201 | ? IDENTIFIER_LENGTH (DECL_NAME (fn)) != 6 | |
2202 | : !lookup_attribute ("returns_nonnull", | |
2203 | TYPE_ATTRIBUTES (fntype))) | |
2204 | warned = warning_at (loc, OPT_Walloc_zero, | |
2205 | "argument %i value is zero", | |
2206 | idx[i] + 1); | |
2207 | } | |
2208 | else if (tree_int_cst_lt (maxobjsize, args[i])) | |
2209 | { | |
2210 | /* G++ emits calls to ::operator new[](SIZE_MAX) in C++98 | |
2211 | mode and with -fno-exceptions as a way to indicate array | |
2212 | size overflow. There's no good way to detect C++98 here | |
2213 | so avoid diagnosing these calls for all C++ modes. */ | |
2214 | if (i == 0 | |
2215 | && fn | |
2216 | && !args[1] | |
2217 | && lang_GNU_CXX () | |
2218 | && DECL_IS_OPERATOR_NEW_P (fn) | |
2219 | && integer_all_onesp (args[i])) | |
2220 | continue; | |
2221 | ||
2222 | warned = warning_at (loc, OPT_Walloc_size_larger_than_, | |
2223 | "argument %i value %qE exceeds " | |
2224 | "maximum object size %E", | |
2225 | idx[i] + 1, args[i], maxobjsize); | |
2226 | } | |
2227 | } | |
2228 | else if (TREE_CODE (args[i]) == SSA_NAME | |
2229 | && get_size_range (args[i], argrange[i])) | |
2230 | { | |
2231 | /* Verify that the argument's range is not negative (including | |
2232 | upper bound of zero). */ | |
2233 | if (tree_int_cst_lt (argrange[i][0], integer_zero_node) | |
2234 | && tree_int_cst_le (argrange[i][1], integer_zero_node)) | |
2235 | { | |
2236 | warned = warning_at (loc, OPT_Walloc_size_larger_than_, | |
2237 | "argument %i range [%E, %E] is negative", | |
2238 | idx[i] + 1, | |
2239 | argrange[i][0], argrange[i][1]); | |
2240 | } | |
2241 | else if (tree_int_cst_lt (maxobjsize, argrange[i][0])) | |
2242 | { | |
2243 | warned = warning_at (loc, OPT_Walloc_size_larger_than_, | |
2244 | "argument %i range [%E, %E] exceeds " | |
2245 | "maximum object size %E", | |
2246 | idx[i] + 1, | |
2247 | argrange[i][0], argrange[i][1], | |
2248 | maxobjsize); | |
2249 | } | |
2250 | } | |
2251 | } | |
2252 | ||
b3aa3288 | 2253 | if (!argrange[0][0]) |
b48d4e68 MS |
2254 | return; |
2255 | ||
2256 | /* For a two-argument alloc_size, validate the product of the two | |
2257 | arguments if both of their values or ranges are known. */ | |
2258 | if (!warned && tree_fits_uhwi_p (argrange[0][0]) | |
2259 | && argrange[1][0] && tree_fits_uhwi_p (argrange[1][0]) | |
2260 | && !integer_onep (argrange[0][0]) | |
2261 | && !integer_onep (argrange[1][0])) | |
2262 | { | |
2263 | /* Check for overflow in the product of a function decorated with | |
2264 | attribute alloc_size (X, Y). */ | |
2265 | unsigned szprec = TYPE_PRECISION (size_type_node); | |
2266 | wide_int x = wi::to_wide (argrange[0][0], szprec); | |
2267 | wide_int y = wi::to_wide (argrange[1][0], szprec); | |
2268 | ||
2269 | wi::overflow_type vflow; | |
2270 | wide_int prod = wi::umul (x, y, &vflow); | |
2271 | ||
2272 | if (vflow) | |
2273 | warned = warning_at (loc, OPT_Walloc_size_larger_than_, | |
2274 | "product %<%E * %E%> of arguments %i and %i " | |
2275 | "exceeds %<SIZE_MAX%>", | |
2276 | argrange[0][0], argrange[1][0], | |
2277 | idx[0] + 1, idx[1] + 1); | |
2278 | else if (wi::ltu_p (wi::to_wide (maxobjsize, szprec), prod)) | |
2279 | warned = warning_at (loc, OPT_Walloc_size_larger_than_, | |
2280 | "product %<%E * %E%> of arguments %i and %i " | |
2281 | "exceeds maximum object size %E", | |
2282 | argrange[0][0], argrange[1][0], | |
2283 | idx[0] + 1, idx[1] + 1, | |
2284 | maxobjsize); | |
2285 | ||
2286 | if (warned) | |
2287 | { | |
2288 | /* Print the full range of each of the two arguments to make | |
2289 | it clear when it is, in fact, in a range and not constant. */ | |
2290 | if (argrange[0][0] != argrange [0][1]) | |
2291 | inform (loc, "argument %i in the range [%E, %E]", | |
2292 | idx[0] + 1, argrange[0][0], argrange[0][1]); | |
2293 | if (argrange[1][0] != argrange [1][1]) | |
2294 | inform (loc, "argument %i in the range [%E, %E]", | |
2295 | idx[1] + 1, argrange[1][0], argrange[1][1]); | |
2296 | } | |
2297 | } | |
2298 | ||
2299 | if (warned && fn) | |
2300 | { | |
2301 | location_t fnloc = DECL_SOURCE_LOCATION (fn); | |
2302 | ||
2303 | if (DECL_IS_UNDECLARED_BUILTIN (fn)) | |
2304 | inform (loc, | |
2305 | "in a call to built-in allocation function %qD", fn); | |
2306 | else | |
2307 | inform (fnloc, | |
2308 | "in a call to allocation function %qD declared here", fn); | |
2309 | } | |
2310 | } | |
2311 | ||
2312 | /* Check a call to an alloca function for an excessive size. */ | |
2313 | ||
ece28da9 MS |
2314 | void |
2315 | pass_waccess::check_alloca (gcall *stmt) | |
b48d4e68 MS |
2316 | { |
2317 | if ((warn_vla_limit >= HOST_WIDE_INT_MAX | |
2318 | && warn_alloc_size_limit < warn_vla_limit) | |
2319 | || (warn_alloca_limit >= HOST_WIDE_INT_MAX | |
2320 | && warn_alloc_size_limit < warn_alloca_limit)) | |
2321 | { | |
2322 | /* -Walloca-larger-than and -Wvla-larger-than settings of less | |
2323 | than HWI_MAX override the more general -Walloc-size-larger-than | |
2324 | so unless either of the former options is smaller than the last | |
2325 | one (wchich would imply that the call was already checked), check | |
2326 | the alloca arguments for overflow. */ | |
2327 | const tree alloc_args[] = { call_arg (stmt, 0), NULL_TREE }; | |
2328 | const int idx[] = { 0, -1 }; | |
2329 | maybe_warn_alloc_args_overflow (stmt, alloc_args, idx); | |
2330 | } | |
2331 | } | |
2332 | ||
2333 | /* Check a call to an allocation function for an excessive size. */ | |
2334 | ||
ece28da9 MS |
2335 | void |
2336 | pass_waccess::check_alloc_size_call (gcall *stmt) | |
b48d4e68 | 2337 | { |
b48d4e68 MS |
2338 | tree fndecl = gimple_call_fndecl (stmt); |
2339 | if (fndecl && gimple_call_builtin_p (stmt, BUILT_IN_NORMAL)) | |
2340 | { | |
2341 | /* Alloca is handled separately. */ | |
2342 | switch (DECL_FUNCTION_CODE (fndecl)) | |
2343 | { | |
2344 | case BUILT_IN_ALLOCA: | |
2345 | case BUILT_IN_ALLOCA_WITH_ALIGN: | |
2346 | case BUILT_IN_ALLOCA_WITH_ALIGN_AND_MAX: | |
2347 | return; | |
2348 | default: | |
2349 | break; | |
2350 | } | |
2351 | } | |
2352 | ||
2353 | tree fntype = gimple_call_fntype (stmt); | |
2354 | tree fntypeattrs = TYPE_ATTRIBUTES (fntype); | |
2355 | ||
2356 | tree alloc_size = lookup_attribute ("alloc_size", fntypeattrs); | |
2357 | if (!alloc_size) | |
2358 | return; | |
2359 | ||
2360 | /* Extract attribute alloc_size from the type of the called expression | |
2361 | (which could be a function or a function pointer) and if set, store | |
2362 | the indices of the corresponding arguments in ALLOC_IDX, and then | |
2363 | the actual argument(s) at those indices in ALLOC_ARGS. */ | |
2364 | int idx[2] = { -1, -1 }; | |
2365 | tree alloc_args[] = { NULL_TREE, NULL_TREE }; | |
eacdfaf7 | 2366 | unsigned nargs = gimple_call_num_args (stmt); |
b48d4e68 MS |
2367 | |
2368 | tree args = TREE_VALUE (alloc_size); | |
2369 | idx[0] = TREE_INT_CST_LOW (TREE_VALUE (args)) - 1; | |
eacdfaf7 JJ |
2370 | /* Avoid invalid calls to functions without a prototype. */ |
2371 | if ((unsigned) idx[0] >= nargs) | |
2372 | return; | |
b48d4e68 MS |
2373 | alloc_args[0] = call_arg (stmt, idx[0]); |
2374 | if (TREE_CHAIN (args)) | |
2375 | { | |
2376 | idx[1] = TREE_INT_CST_LOW (TREE_VALUE (TREE_CHAIN (args))) - 1; | |
eacdfaf7 JJ |
2377 | if ((unsigned) idx[1] >= nargs) |
2378 | return; | |
b48d4e68 MS |
2379 | alloc_args[1] = call_arg (stmt, idx[1]); |
2380 | } | |
2381 | ||
2382 | maybe_warn_alloc_args_overflow (stmt, alloc_args, idx); | |
2383 | } | |
2384 | ||
81d6cdd3 MS |
2385 | /* Check a call STMT to strcat() for overflow and warn if it does. */ |
2386 | ||
ece28da9 MS |
2387 | void |
2388 | pass_waccess::check_strcat (gcall *stmt) | |
81d6cdd3 | 2389 | { |
b48d4e68 | 2390 | if (!warn_stringop_overflow && !warn_stringop_overread) |
81d6cdd3 MS |
2391 | return; |
2392 | ||
2393 | tree dest = call_arg (stmt, 0); | |
2394 | tree src = call_arg (stmt, 1); | |
2395 | ||
2396 | /* There is no way here to determine the length of the string in | |
2397 | the destination to which the SRC string is being appended so | |
2398 | just diagnose cases when the souce string is longer than | |
2399 | the destination object. */ | |
9a27acc3 MS |
2400 | access_data data (m_ptr_qry.rvals, stmt, access_read_write, NULL_TREE, |
2401 | true, NULL_TREE, true); | |
81d6cdd3 | 2402 | const int ost = warn_stringop_overflow ? warn_stringop_overflow - 1 : 1; |
9a27acc3 MS |
2403 | compute_objsize (src, stmt, ost, &data.src, &m_ptr_qry); |
2404 | tree destsize = compute_objsize (dest, stmt, ost, &data.dst, &m_ptr_qry); | |
81d6cdd3 MS |
2405 | |
2406 | check_access (stmt, /*dstwrite=*/NULL_TREE, /*maxread=*/NULL_TREE, | |
9a27acc3 | 2407 | src, destsize, data.mode, &data, m_ptr_qry.rvals); |
81d6cdd3 MS |
2408 | } |
2409 | ||
2410 | /* Check a call STMT to strcat() for overflow and warn if it does. */ | |
2411 | ||
ece28da9 MS |
2412 | void |
2413 | pass_waccess::check_strncat (gcall *stmt) | |
81d6cdd3 | 2414 | { |
b48d4e68 | 2415 | if (!warn_stringop_overflow && !warn_stringop_overread) |
81d6cdd3 MS |
2416 | return; |
2417 | ||
2418 | tree dest = call_arg (stmt, 0); | |
2419 | tree src = call_arg (stmt, 1); | |
2420 | /* The upper bound on the number of bytes to write. */ | |
2421 | tree maxread = call_arg (stmt, 2); | |
2422 | ||
2423 | /* Detect unterminated source (only). */ | |
2424 | if (!check_nul_terminated_array (stmt, src, maxread)) | |
2425 | return; | |
2426 | ||
2427 | /* The length of the source sequence. */ | |
2428 | tree slen = c_strlen (src, 1); | |
2429 | ||
2430 | /* Try to determine the range of lengths that the source expression | |
2431 | refers to. Since the lengths are only used for warning and not | |
2432 | for code generation disable strict mode below. */ | |
2433 | tree maxlen = slen; | |
2434 | if (!maxlen) | |
2435 | { | |
2436 | c_strlen_data lendata = { }; | |
2437 | get_range_strlen (src, &lendata, /* eltsize = */ 1); | |
2438 | maxlen = lendata.maxbound; | |
2439 | } | |
2440 | ||
9a27acc3 | 2441 | access_data data (m_ptr_qry.rvals, stmt, access_read_write); |
81d6cdd3 MS |
2442 | /* Try to verify that the destination is big enough for the shortest |
2443 | string. First try to determine the size of the destination object | |
2444 | into which the source is being copied. */ | |
ece28da9 | 2445 | const int ost = warn_stringop_overflow - 1; |
9a27acc3 | 2446 | tree destsize = compute_objsize (dest, stmt, ost, &data.dst, &m_ptr_qry); |
81d6cdd3 MS |
2447 | |
2448 | /* Add one for the terminating nul. */ | |
2449 | tree srclen = (maxlen | |
2450 | ? fold_build2 (PLUS_EXPR, size_type_node, maxlen, | |
2451 | size_one_node) | |
2452 | : NULL_TREE); | |
2453 | ||
2454 | /* The strncat function copies at most MAXREAD bytes and always appends | |
2455 | the terminating nul so the specified upper bound should never be equal | |
2456 | to (or greater than) the size of the destination. */ | |
2457 | if (tree_fits_uhwi_p (maxread) && tree_fits_uhwi_p (destsize) | |
2458 | && tree_int_cst_equal (destsize, maxread)) | |
2459 | { | |
2460 | location_t loc = get_location (stmt); | |
2461 | warning_at (loc, OPT_Wstringop_overflow_, | |
2462 | "%qD specified bound %E equals destination size", | |
2463 | get_callee_fndecl (stmt), maxread); | |
2464 | ||
2465 | return; | |
2466 | } | |
2467 | ||
2468 | if (!srclen | |
2469 | || (maxread && tree_fits_uhwi_p (maxread) | |
2470 | && tree_fits_uhwi_p (srclen) | |
2471 | && tree_int_cst_lt (maxread, srclen))) | |
2472 | srclen = maxread; | |
2473 | ||
2474 | check_access (stmt, /*dstwrite=*/NULL_TREE, maxread, srclen, | |
9a27acc3 | 2475 | destsize, data.mode, &data, m_ptr_qry.rvals); |
81d6cdd3 MS |
2476 | } |
2477 | ||
2478 | /* Check a call STMT to stpcpy() or strcpy() for overflow and warn | |
2479 | if it does. */ | |
2480 | ||
ece28da9 MS |
2481 | void |
2482 | pass_waccess::check_stxcpy (gcall *stmt) | |
81d6cdd3 MS |
2483 | { |
2484 | tree dst = call_arg (stmt, 0); | |
2485 | tree src = call_arg (stmt, 1); | |
2486 | ||
2487 | tree size; | |
2488 | bool exact; | |
2489 | if (tree nonstr = unterminated_array (src, &size, &exact)) | |
2490 | { | |
2491 | /* NONSTR refers to the non-nul terminated constant array. */ | |
2492 | warn_string_no_nul (get_location (stmt), stmt, NULL, src, nonstr, | |
2493 | size, exact); | |
2494 | return; | |
2495 | } | |
2496 | ||
2497 | if (warn_stringop_overflow) | |
2498 | { | |
9a27acc3 MS |
2499 | access_data data (m_ptr_qry.rvals, stmt, access_read_write, NULL_TREE, |
2500 | true, NULL_TREE, true); | |
81d6cdd3 | 2501 | const int ost = warn_stringop_overflow ? warn_stringop_overflow - 1 : 1; |
9a27acc3 MS |
2502 | compute_objsize (src, stmt, ost, &data.src, &m_ptr_qry); |
2503 | tree dstsize = compute_objsize (dst, stmt, ost, &data.dst, &m_ptr_qry); | |
81d6cdd3 MS |
2504 | check_access (stmt, /*dstwrite=*/ NULL_TREE, |
2505 | /*maxread=*/ NULL_TREE, /*srcstr=*/ src, | |
9a27acc3 | 2506 | dstsize, data.mode, &data, m_ptr_qry.rvals); |
81d6cdd3 MS |
2507 | } |
2508 | ||
2509 | /* Check to see if the argument was declared attribute nonstring | |
2510 | and if so, issue a warning since at this point it's not known | |
2511 | to be nul-terminated. */ | |
2512 | tree fndecl = get_callee_fndecl (stmt); | |
2513 | maybe_warn_nonstring_arg (fndecl, stmt); | |
2514 | } | |
2515 | ||
2516 | /* Check a call STMT to stpncpy() or strncpy() for overflow and warn | |
2517 | if it does. */ | |
2518 | ||
ece28da9 MS |
2519 | void |
2520 | pass_waccess::check_stxncpy (gcall *stmt) | |
81d6cdd3 MS |
2521 | { |
2522 | if (!warn_stringop_overflow) | |
2523 | return; | |
2524 | ||
2525 | tree dst = call_arg (stmt, 0); | |
2526 | tree src = call_arg (stmt, 1); | |
2527 | /* The number of bytes to write (not the maximum). */ | |
2528 | tree len = call_arg (stmt, 2); | |
2529 | ||
9a27acc3 MS |
2530 | access_data data (m_ptr_qry.rvals, stmt, access_read_write, len, true, len, |
2531 | true); | |
81d6cdd3 | 2532 | const int ost = warn_stringop_overflow ? warn_stringop_overflow - 1 : 1; |
9a27acc3 MS |
2533 | compute_objsize (src, stmt, ost, &data.src, &m_ptr_qry); |
2534 | tree dstsize = compute_objsize (dst, stmt, ost, &data.dst, &m_ptr_qry); | |
81d6cdd3 | 2535 | |
9a27acc3 MS |
2536 | check_access (stmt, /*dstwrite=*/len, /*maxread=*/len, src, dstsize, |
2537 | data.mode, &data, m_ptr_qry.rvals); | |
81d6cdd3 MS |
2538 | } |
2539 | ||
2540 | /* Check a call STMT to stpncpy() or strncpy() for overflow and warn | |
2541 | if it does. */ | |
2542 | ||
ece28da9 MS |
2543 | void |
2544 | pass_waccess::check_strncmp (gcall *stmt) | |
81d6cdd3 MS |
2545 | { |
2546 | if (!warn_stringop_overread) | |
2547 | return; | |
2548 | ||
2549 | tree arg1 = call_arg (stmt, 0); | |
2550 | tree arg2 = call_arg (stmt, 1); | |
2551 | tree bound = call_arg (stmt, 2); | |
2552 | ||
2553 | /* First check each argument separately, considering the bound. */ | |
2554 | if (!check_nul_terminated_array (stmt, arg1, bound) | |
2555 | || !check_nul_terminated_array (stmt, arg2, bound)) | |
2556 | return; | |
2557 | ||
2558 | /* A strncmp read from each argument is constrained not just by | |
2559 | the bound but also by the length of the shorter string. Specifying | |
2560 | a bound that's larger than the size of either array makes no sense | |
2561 | and is likely a bug. When the length of neither of the two strings | |
2562 | is known but the sizes of both of the arrays they are stored in is, | |
2563 | issue a warning if the bound is larger than than the size of | |
2564 | the larger of the two arrays. */ | |
2565 | ||
2566 | c_strlen_data lendata1{ }, lendata2{ }; | |
2567 | tree len1 = c_strlen (arg1, 1, &lendata1); | |
2568 | tree len2 = c_strlen (arg2, 1, &lendata2); | |
2569 | ||
9a27acc3 MS |
2570 | if (len1 && TREE_CODE (len1) != INTEGER_CST) |
2571 | len1 = NULL_TREE; | |
2572 | if (len2 && TREE_CODE (len2) != INTEGER_CST) | |
2573 | len2 = NULL_TREE; | |
2574 | ||
81d6cdd3 MS |
2575 | if (len1 && len2) |
2576 | /* If the length of both arguments was computed they must both be | |
2577 | nul-terminated and no further checking is necessary regardless | |
2578 | of the bound. */ | |
2579 | return; | |
2580 | ||
2581 | /* Check to see if the argument was declared with attribute nonstring | |
2582 | and if so, issue a warning since at this point it's not known to be | |
2583 | nul-terminated. */ | |
2584 | if (maybe_warn_nonstring_arg (get_callee_fndecl (stmt), stmt)) | |
2585 | return; | |
2586 | ||
9a27acc3 MS |
2587 | access_data adata1 (m_ptr_qry.rvals, stmt, access_read_only, NULL_TREE, false, |
2588 | bound, true); | |
2589 | access_data adata2 (m_ptr_qry.rvals, stmt, access_read_only, NULL_TREE, false, | |
2590 | bound, true); | |
81d6cdd3 MS |
2591 | |
2592 | /* Determine the range of the bound first and bail if it fails; it's | |
2593 | cheaper than computing the size of the objects. */ | |
2594 | tree bndrng[2] = { NULL_TREE, NULL_TREE }; | |
f9379fcb | 2595 | get_size_range (m_ptr_qry.rvals, bound, stmt, bndrng, adata1.src_bndrng); |
81d6cdd3 MS |
2596 | if (!bndrng[0] || integer_zerop (bndrng[0])) |
2597 | return; | |
2598 | ||
2599 | if (len1 && tree_int_cst_lt (len1, bndrng[0])) | |
2600 | bndrng[0] = len1; | |
2601 | if (len2 && tree_int_cst_lt (len2, bndrng[0])) | |
2602 | bndrng[0] = len2; | |
2603 | ||
2604 | /* compute_objsize almost never fails (and ultimately should never | |
2605 | fail). Don't bother to handle the rare case when it does. */ | |
9a27acc3 MS |
2606 | if (!compute_objsize (arg1, stmt, 1, &adata1.src, &m_ptr_qry) |
2607 | || !compute_objsize (arg2, stmt, 1, &adata2.src, &m_ptr_qry)) | |
81d6cdd3 MS |
2608 | return; |
2609 | ||
2610 | /* Compute the size of the remaining space in each array after | |
2611 | subtracting any offset into it. */ | |
2612 | offset_int rem1 = adata1.src.size_remaining (); | |
2613 | offset_int rem2 = adata2.src.size_remaining (); | |
2614 | ||
2615 | /* Cap REM1 and REM2 at the other if the other's argument is known | |
2616 | to be an unterminated array, either because there's no space | |
2617 | left in it after adding its offset or because it's constant and | |
2618 | has no nul. */ | |
2619 | if (rem1 == 0 || (rem1 < rem2 && lendata1.decl)) | |
2620 | rem2 = rem1; | |
2621 | else if (rem2 == 0 || (rem2 < rem1 && lendata2.decl)) | |
2622 | rem1 = rem2; | |
2623 | ||
2624 | /* Point PAD at the array to reference in the note if a warning | |
2625 | is issued. */ | |
2626 | access_data *pad = len1 ? &adata2 : &adata1; | |
2627 | offset_int maxrem = wi::max (rem1, rem2, UNSIGNED); | |
2628 | if (lendata1.decl || lendata2.decl | |
2629 | || maxrem < wi::to_offset (bndrng[0])) | |
2630 | { | |
2631 | /* Warn when either argument isn't nul-terminated or the maximum | |
2632 | remaining space in the two arrays is less than the bound. */ | |
2633 | tree func = get_callee_fndecl (stmt); | |
2634 | location_t loc = gimple_location (stmt); | |
2635 | maybe_warn_for_bound (OPT_Wstringop_overread, loc, stmt, func, | |
2636 | bndrng, wide_int_to_tree (sizetype, maxrem), | |
2637 | pad); | |
2638 | } | |
2639 | } | |
2640 | ||
ece28da9 MS |
2641 | /* Determine and check the sizes of the source and the destination |
2642 | of calls to __builtin_{bzero,memcpy,mempcpy,memset} calls. STMT is | |
2643 | the call statement, DEST is the destination argument, SRC is the source | |
2644 | argument or null, and SIZE is the number of bytes being accessed. Use | |
2645 | Object Size type-0 regardless of the OPT_Wstringop_overflow_ setting. | |
2646 | Return true on success (no overflow or invalid sizes), false otherwise. */ | |
2647 | ||
2648 | void | |
2649 | pass_waccess::check_memop_access (gimple *stmt, tree dest, tree src, tree size) | |
2650 | { | |
2651 | /* For functions like memset and memcpy that operate on raw memory | |
2652 | try to determine the size of the largest source and destination | |
2653 | object using type-0 Object Size regardless of the object size | |
2654 | type specified by the option. */ | |
9a27acc3 | 2655 | access_data data (m_ptr_qry.rvals, stmt, access_read_write); |
ece28da9 | 2656 | tree srcsize |
9a27acc3 MS |
2657 | = src ? compute_objsize (src, stmt, 0, &data.src, &m_ptr_qry) : NULL_TREE; |
2658 | tree dstsize = compute_objsize (dest, stmt, 0, &data.dst, &m_ptr_qry); | |
2659 | ||
2660 | check_access (stmt, size, /*maxread=*/NULL_TREE, srcsize, dstsize, | |
2661 | data.mode, &data, m_ptr_qry.rvals); | |
2662 | } | |
2663 | ||
2664 | /* A convenience wrapper for check_access to check access by a read-only | |
2665 | function like puts or strcmp. */ | |
2666 | ||
2667 | void | |
2668 | pass_waccess::check_read_access (gimple *stmt, tree src, | |
2669 | tree bound /* = NULL_TREE */, | |
2670 | int ost /* = 1 */) | |
2671 | { | |
2672 | if (!warn_stringop_overread) | |
2673 | return; | |
2674 | ||
2675 | if (bound && !useless_type_conversion_p (size_type_node, TREE_TYPE (bound))) | |
2676 | bound = fold_convert (size_type_node, bound); | |
2677 | ||
2678 | tree fndecl = get_callee_fndecl (stmt); | |
2679 | maybe_warn_nonstring_arg (fndecl, stmt); | |
ece28da9 | 2680 | |
9a27acc3 MS |
2681 | access_data data (m_ptr_qry.rvals, stmt, access_read_only, NULL_TREE, |
2682 | false, bound, true); | |
2683 | compute_objsize (src, stmt, ost, &data.src, &m_ptr_qry); | |
2684 | check_access (stmt, /*dstwrite=*/ NULL_TREE, /*maxread=*/ bound, | |
2685 | /*srcstr=*/ src, /*dstsize=*/ NULL_TREE, data.mode, | |
2686 | &data, m_ptr_qry.rvals); | |
ece28da9 MS |
2687 | } |
2688 | ||
9a27acc3 | 2689 | |
88b504b7 MS |
2690 | /* Check a call STMT to an atomic or sync built-in. */ |
2691 | ||
2692 | bool | |
2693 | pass_waccess::check_atomic_builtin (gcall *stmt) | |
2694 | { | |
2695 | tree callee = gimple_call_fndecl (stmt); | |
2696 | if (!callee) | |
2697 | return false; | |
2698 | ||
2699 | /* The size in bytes of the access by the function, and the number | |
2700 | of the second argument to check (if any). */ | |
2701 | unsigned bytes = 0, arg2 = UINT_MAX; | |
2702 | ||
2703 | switch (DECL_FUNCTION_CODE (callee)) | |
2704 | { | |
2705 | #define BUILTIN_ACCESS_SIZE_FNSPEC(N) \ | |
2706 | BUILT_IN_ATOMIC_LOAD_ ## N: \ | |
2707 | case BUILT_IN_SYNC_FETCH_AND_ADD_ ## N: \ | |
2708 | case BUILT_IN_SYNC_FETCH_AND_SUB_ ## N: \ | |
2709 | case BUILT_IN_SYNC_FETCH_AND_OR_ ## N: \ | |
2710 | case BUILT_IN_SYNC_FETCH_AND_AND_ ## N: \ | |
2711 | case BUILT_IN_SYNC_FETCH_AND_XOR_ ## N: \ | |
2712 | case BUILT_IN_SYNC_FETCH_AND_NAND_ ## N: \ | |
2713 | case BUILT_IN_SYNC_ADD_AND_FETCH_ ## N: \ | |
2714 | case BUILT_IN_SYNC_SUB_AND_FETCH_ ## N: \ | |
2715 | case BUILT_IN_SYNC_OR_AND_FETCH_ ## N: \ | |
2716 | case BUILT_IN_SYNC_AND_AND_FETCH_ ## N: \ | |
2717 | case BUILT_IN_SYNC_XOR_AND_FETCH_ ## N: \ | |
2718 | case BUILT_IN_SYNC_NAND_AND_FETCH_ ## N: \ | |
2719 | case BUILT_IN_SYNC_LOCK_TEST_AND_SET_ ## N: \ | |
2720 | case BUILT_IN_SYNC_BOOL_COMPARE_AND_SWAP_ ## N: \ | |
2721 | case BUILT_IN_SYNC_VAL_COMPARE_AND_SWAP_ ## N: \ | |
2722 | case BUILT_IN_SYNC_LOCK_RELEASE_ ## N: \ | |
2723 | case BUILT_IN_ATOMIC_EXCHANGE_ ## N: \ | |
2724 | case BUILT_IN_ATOMIC_STORE_ ## N: \ | |
2725 | case BUILT_IN_ATOMIC_ADD_FETCH_ ## N: \ | |
2726 | case BUILT_IN_ATOMIC_SUB_FETCH_ ## N: \ | |
2727 | case BUILT_IN_ATOMIC_AND_FETCH_ ## N: \ | |
2728 | case BUILT_IN_ATOMIC_NAND_FETCH_ ## N: \ | |
2729 | case BUILT_IN_ATOMIC_XOR_FETCH_ ## N: \ | |
2730 | case BUILT_IN_ATOMIC_OR_FETCH_ ## N: \ | |
2731 | case BUILT_IN_ATOMIC_FETCH_ADD_ ## N: \ | |
2732 | case BUILT_IN_ATOMIC_FETCH_SUB_ ## N: \ | |
2733 | case BUILT_IN_ATOMIC_FETCH_AND_ ## N: \ | |
2734 | case BUILT_IN_ATOMIC_FETCH_NAND_ ## N: \ | |
2735 | case BUILT_IN_ATOMIC_FETCH_OR_ ## N: \ | |
2736 | case BUILT_IN_ATOMIC_FETCH_XOR_ ## N: \ | |
2737 | bytes = N; \ | |
2738 | break; \ | |
2739 | case BUILT_IN_ATOMIC_COMPARE_EXCHANGE_ ## N: \ | |
2740 | bytes = N; \ | |
2741 | arg2 = 1 | |
2742 | ||
2743 | case BUILTIN_ACCESS_SIZE_FNSPEC (1); | |
2744 | break; | |
2745 | case BUILTIN_ACCESS_SIZE_FNSPEC (2); | |
2746 | break; | |
2747 | case BUILTIN_ACCESS_SIZE_FNSPEC (4); | |
2748 | break; | |
2749 | case BUILTIN_ACCESS_SIZE_FNSPEC (8); | |
2750 | break; | |
2751 | case BUILTIN_ACCESS_SIZE_FNSPEC (16); | |
2752 | break; | |
2753 | ||
2754 | default: | |
2755 | return false; | |
2756 | } | |
2757 | ||
2758 | tree size = build_int_cstu (sizetype, bytes); | |
2759 | tree dst = gimple_call_arg (stmt, 0); | |
2760 | check_memop_access (stmt, dst, NULL_TREE, size); | |
2761 | ||
2762 | if (arg2 != UINT_MAX) | |
2763 | { | |
2764 | tree dst = gimple_call_arg (stmt, arg2); | |
2765 | check_memop_access (stmt, dst, NULL_TREE, size); | |
2766 | } | |
2767 | ||
2768 | return true; | |
2769 | } | |
2770 | ||
81d6cdd3 MS |
2771 | /* Check call STMT to a built-in function for invalid accesses. Return |
2772 | true if a call has been handled. */ | |
2773 | ||
2774 | bool | |
2775 | pass_waccess::check_builtin (gcall *stmt) | |
2776 | { | |
2777 | tree callee = gimple_call_fndecl (stmt); | |
2778 | if (!callee) | |
2779 | return false; | |
2780 | ||
2781 | switch (DECL_FUNCTION_CODE (callee)) | |
2782 | { | |
b48d4e68 MS |
2783 | case BUILT_IN_ALLOCA: |
2784 | case BUILT_IN_ALLOCA_WITH_ALIGN: | |
2785 | case BUILT_IN_ALLOCA_WITH_ALIGN_AND_MAX: | |
2786 | check_alloca (stmt); | |
2787 | return true; | |
2788 | ||
9a27acc3 MS |
2789 | case BUILT_IN_EXECL: |
2790 | case BUILT_IN_EXECLE: | |
2791 | case BUILT_IN_EXECLP: | |
2792 | case BUILT_IN_EXECV: | |
2793 | case BUILT_IN_EXECVE: | |
2794 | case BUILT_IN_EXECVP: | |
2795 | check_read_access (stmt, call_arg (stmt, 0)); | |
2796 | return true; | |
2797 | ||
81d6cdd3 MS |
2798 | case BUILT_IN_GETTEXT: |
2799 | case BUILT_IN_PUTS: | |
2800 | case BUILT_IN_PUTS_UNLOCKED: | |
2801 | case BUILT_IN_STRDUP: | |
2802 | check_read_access (stmt, call_arg (stmt, 0)); | |
2803 | return true; | |
2804 | ||
2805 | case BUILT_IN_INDEX: | |
2806 | case BUILT_IN_RINDEX: | |
2807 | case BUILT_IN_STRCHR: | |
2808 | case BUILT_IN_STRRCHR: | |
2809 | case BUILT_IN_STRLEN: | |
2810 | check_read_access (stmt, call_arg (stmt, 0)); | |
2811 | return true; | |
2812 | ||
2813 | case BUILT_IN_FPUTS: | |
2814 | case BUILT_IN_FPUTS_UNLOCKED: | |
2815 | check_read_access (stmt, call_arg (stmt, 0)); | |
2816 | return true; | |
2817 | ||
2818 | case BUILT_IN_STRNDUP: | |
2819 | case BUILT_IN_STRNLEN: | |
9a27acc3 MS |
2820 | { |
2821 | tree str = call_arg (stmt, 0); | |
2822 | tree len = call_arg (stmt, 1); | |
2823 | check_read_access (stmt, str, len); | |
2824 | return true; | |
2825 | } | |
81d6cdd3 MS |
2826 | |
2827 | case BUILT_IN_STRCAT: | |
2828 | check_strcat (stmt); | |
2829 | return true; | |
2830 | ||
2831 | case BUILT_IN_STRNCAT: | |
2832 | check_strncat (stmt); | |
2833 | return true; | |
2834 | ||
2835 | case BUILT_IN_STPCPY: | |
2836 | case BUILT_IN_STRCPY: | |
2837 | check_stxcpy (stmt); | |
2838 | return true; | |
2839 | ||
2840 | case BUILT_IN_STPNCPY: | |
2841 | case BUILT_IN_STRNCPY: | |
2842 | check_stxncpy (stmt); | |
2843 | return true; | |
2844 | ||
2845 | case BUILT_IN_STRCASECMP: | |
2846 | case BUILT_IN_STRCMP: | |
2847 | case BUILT_IN_STRPBRK: | |
2848 | case BUILT_IN_STRSPN: | |
2849 | case BUILT_IN_STRCSPN: | |
2850 | case BUILT_IN_STRSTR: | |
2851 | check_read_access (stmt, call_arg (stmt, 0)); | |
2852 | check_read_access (stmt, call_arg (stmt, 1)); | |
2853 | return true; | |
2854 | ||
2855 | case BUILT_IN_STRNCASECMP: | |
2856 | case BUILT_IN_STRNCMP: | |
2857 | check_strncmp (stmt); | |
2858 | return true; | |
2859 | ||
2860 | case BUILT_IN_MEMCMP: | |
2861 | { | |
2862 | tree a1 = call_arg (stmt, 0); | |
2863 | tree a2 = call_arg (stmt, 1); | |
2864 | tree len = call_arg (stmt, 2); | |
2865 | check_read_access (stmt, a1, len, 0); | |
2866 | check_read_access (stmt, a2, len, 0); | |
2867 | return true; | |
2868 | } | |
2869 | ||
2870 | case BUILT_IN_MEMCPY: | |
2871 | case BUILT_IN_MEMPCPY: | |
2872 | case BUILT_IN_MEMMOVE: | |
2873 | { | |
2874 | tree dst = call_arg (stmt, 0); | |
2875 | tree src = call_arg (stmt, 1); | |
2876 | tree len = call_arg (stmt, 2); | |
2877 | check_memop_access (stmt, dst, src, len); | |
2878 | return true; | |
2879 | } | |
2880 | ||
2881 | case BUILT_IN_MEMCHR: | |
2882 | { | |
2883 | tree src = call_arg (stmt, 0); | |
2884 | tree len = call_arg (stmt, 2); | |
2885 | check_read_access (stmt, src, len, 0); | |
2886 | return true; | |
2887 | } | |
2888 | ||
2889 | case BUILT_IN_MEMSET: | |
2890 | { | |
2891 | tree dst = call_arg (stmt, 0); | |
2892 | tree len = call_arg (stmt, 2); | |
2893 | check_memop_access (stmt, dst, NULL_TREE, len); | |
2894 | return true; | |
2895 | } | |
2896 | ||
2897 | default: | |
88b504b7 MS |
2898 | if (check_atomic_builtin (stmt)) |
2899 | return true; | |
2900 | break; | |
81d6cdd3 | 2901 | } |
88b504b7 | 2902 | return false; |
81d6cdd3 MS |
2903 | } |
2904 | ||
b48d4e68 MS |
2905 | /* Returns the type of the argument ARGNO to function with type FNTYPE |
2906 | or null when the typoe cannot be determined or no such argument exists. */ | |
2907 | ||
2908 | static tree | |
2909 | fntype_argno_type (tree fntype, unsigned argno) | |
2910 | { | |
2911 | if (!prototype_p (fntype)) | |
2912 | return NULL_TREE; | |
2913 | ||
2914 | tree argtype; | |
2915 | function_args_iterator it; | |
2916 | FOREACH_FUNCTION_ARGS (fntype, argtype, it) | |
2917 | if (argno-- == 0) | |
2918 | return argtype; | |
2919 | ||
2920 | return NULL_TREE; | |
2921 | } | |
2922 | ||
2923 | /* Helper to append the "human readable" attribute access specification | |
2924 | described by ACCESS to the array ATTRSTR with size STRSIZE. Used in | |
2925 | diagnostics. */ | |
2926 | ||
2927 | static inline void | |
2928 | append_attrname (const std::pair<int, attr_access> &access, | |
2929 | char *attrstr, size_t strsize) | |
2930 | { | |
2931 | if (access.second.internal_p) | |
2932 | return; | |
2933 | ||
2934 | tree str = access.second.to_external_string (); | |
2935 | gcc_assert (strsize >= (size_t) TREE_STRING_LENGTH (str)); | |
2936 | strcpy (attrstr, TREE_STRING_POINTER (str)); | |
2937 | } | |
2938 | ||
2939 | /* Iterate over attribute access read-only, read-write, and write-only | |
2940 | arguments and diagnose past-the-end accesses and related problems | |
2941 | in the function call EXP. */ | |
2942 | ||
ece28da9 MS |
2943 | void |
2944 | pass_waccess::maybe_check_access_sizes (rdwr_map *rwm, tree fndecl, tree fntype, | |
2945 | gimple *stmt) | |
b48d4e68 MS |
2946 | { |
2947 | auto_diagnostic_group adg; | |
2948 | ||
2949 | /* Set if a warning has been issued for any argument (used to decide | |
2950 | whether to emit an informational note at the end). */ | |
2951 | opt_code opt_warned = no_warning; | |
2952 | ||
2953 | /* A string describing the attributes that the warnings issued by this | |
2954 | function apply to. Used to print one informational note per function | |
2955 | call, rather than one per warning. That reduces clutter. */ | |
2956 | char attrstr[80]; | |
2957 | attrstr[0] = 0; | |
2958 | ||
2959 | for (rdwr_map::iterator it = rwm->begin (); it != rwm->end (); ++it) | |
2960 | { | |
2961 | std::pair<int, attr_access> access = *it; | |
2962 | ||
2963 | /* Get the function call arguments corresponding to the attribute's | |
2964 | positional arguments. When both arguments have been specified | |
2965 | there will be two entries in *RWM, one for each. They are | |
2966 | cross-referenced by their respective argument numbers in | |
2967 | ACCESS.PTRARG and ACCESS.SIZARG. */ | |
2968 | const int ptridx = access.second.ptrarg; | |
2969 | const int sizidx = access.second.sizarg; | |
2970 | ||
2971 | gcc_assert (ptridx != -1); | |
2972 | gcc_assert (access.first == ptridx || access.first == sizidx); | |
2973 | ||
2974 | /* The pointer is set to null for the entry corresponding to | |
2975 | the size argument. Skip it. It's handled when the entry | |
2976 | corresponding to the pointer argument comes up. */ | |
2977 | if (!access.second.ptr) | |
2978 | continue; | |
2979 | ||
2980 | tree ptrtype = fntype_argno_type (fntype, ptridx); | |
ea9e0d6c MS |
2981 | if (!ptrtype) |
2982 | /* A function with a prototype was redeclared without one and | |
2983 | the protype has been lost. See pr102759. Avoid dealing | |
2984 | with this pathological case. */ | |
2985 | return; | |
2986 | ||
b48d4e68 MS |
2987 | tree argtype = TREE_TYPE (ptrtype); |
2988 | ||
ea9e0d6c MS |
2989 | /* The size of the access by the call in elements. */ |
2990 | tree access_nelts; | |
b48d4e68 MS |
2991 | if (sizidx == -1) |
2992 | { | |
2993 | /* If only the pointer attribute operand was specified and | |
2994 | not size, set SIZE to the greater of MINSIZE or size of | |
2995 | one element of the pointed to type to detect smaller | |
2996 | objects (null pointers are diagnosed in this case only | |
2997 | if the pointer is also declared with attribute nonnull. */ | |
2998 | if (access.second.minsize | |
2999 | && access.second.minsize != HOST_WIDE_INT_M1U) | |
ea9e0d6c | 3000 | access_nelts = build_int_cstu (sizetype, access.second.minsize); |
b48d4e68 | 3001 | else |
ea9e0d6c | 3002 | access_nelts = size_one_node; |
b48d4e68 MS |
3003 | } |
3004 | else | |
ea9e0d6c | 3005 | access_nelts = rwm->get (sizidx)->size; |
b48d4e68 MS |
3006 | |
3007 | /* Format the value or range to avoid an explosion of messages. */ | |
3008 | char sizstr[80]; | |
3009 | tree sizrng[2] = { size_zero_node, build_all_ones_cst (sizetype) }; | |
ea9e0d6c | 3010 | if (get_size_range (m_ptr_qry.rvals, access_nelts, stmt, sizrng, 1)) |
b48d4e68 MS |
3011 | { |
3012 | char *s0 = print_generic_expr_to_str (sizrng[0]); | |
3013 | if (tree_int_cst_equal (sizrng[0], sizrng[1])) | |
3014 | { | |
3015 | gcc_checking_assert (strlen (s0) < sizeof sizstr); | |
3016 | strcpy (sizstr, s0); | |
3017 | } | |
3018 | else | |
3019 | { | |
3020 | char *s1 = print_generic_expr_to_str (sizrng[1]); | |
3021 | gcc_checking_assert (strlen (s0) + strlen (s1) | |
3022 | < sizeof sizstr - 4); | |
6b8b9596 | 3023 | sprintf (sizstr, "[%.37s, %.37s]", s0, s1); |
b48d4e68 MS |
3024 | free (s1); |
3025 | } | |
3026 | free (s0); | |
3027 | } | |
3028 | else | |
3029 | *sizstr = '\0'; | |
3030 | ||
3031 | /* Set if a warning has been issued for the current argument. */ | |
3032 | opt_code arg_warned = no_warning; | |
3033 | location_t loc = get_location (stmt); | |
3034 | tree ptr = access.second.ptr; | |
3035 | if (*sizstr | |
3036 | && tree_int_cst_sgn (sizrng[0]) < 0 | |
3037 | && tree_int_cst_sgn (sizrng[1]) < 0) | |
3038 | { | |
3039 | /* Warn about negative sizes. */ | |
3040 | if (access.second.internal_p) | |
3041 | { | |
3042 | const std::string argtypestr | |
3043 | = access.second.array_as_string (ptrtype); | |
3044 | ||
3045 | if (warning_at (loc, OPT_Wstringop_overflow_, | |
3046 | "bound argument %i value %s is " | |
3047 | "negative for a variable length array " | |
3048 | "argument %i of type %s", | |
3049 | sizidx + 1, sizstr, | |
3050 | ptridx + 1, argtypestr.c_str ())) | |
3051 | arg_warned = OPT_Wstringop_overflow_; | |
3052 | } | |
3053 | else if (warning_at (loc, OPT_Wstringop_overflow_, | |
3054 | "argument %i value %s is negative", | |
3055 | sizidx + 1, sizstr)) | |
3056 | arg_warned = OPT_Wstringop_overflow_; | |
3057 | ||
3058 | if (arg_warned != no_warning) | |
3059 | { | |
3060 | append_attrname (access, attrstr, sizeof attrstr); | |
3061 | /* Remember a warning has been issued and avoid warning | |
3062 | again below for the same attribute. */ | |
3063 | opt_warned = arg_warned; | |
3064 | continue; | |
3065 | } | |
3066 | } | |
3067 | ||
ea9e0d6c MS |
3068 | /* The size of the access by the call in bytes. */ |
3069 | tree access_size = NULL_TREE; | |
b48d4e68 MS |
3070 | if (tree_int_cst_sgn (sizrng[0]) >= 0) |
3071 | { | |
3072 | if (COMPLETE_TYPE_P (argtype)) | |
3073 | { | |
3074 | /* Multiply ACCESS_SIZE by the size of the type the pointer | |
3075 | argument points to. If it's incomplete the size is used | |
3076 | as is. */ | |
3077 | if (tree argsize = TYPE_SIZE_UNIT (argtype)) | |
3078 | if (TREE_CODE (argsize) == INTEGER_CST) | |
3079 | { | |
3080 | const int prec = TYPE_PRECISION (sizetype); | |
3081 | wide_int minsize = wi::to_wide (sizrng[0], prec); | |
3082 | minsize *= wi::to_wide (argsize, prec); | |
3083 | access_size = wide_int_to_tree (sizetype, minsize); | |
3084 | } | |
3085 | } | |
ea9e0d6c MS |
3086 | else |
3087 | access_size = access_nelts; | |
b48d4e68 | 3088 | } |
b48d4e68 MS |
3089 | |
3090 | if (integer_zerop (ptr)) | |
3091 | { | |
3092 | if (sizidx >= 0 && tree_int_cst_sgn (sizrng[0]) > 0) | |
3093 | { | |
3094 | /* Warn about null pointers with positive sizes. This is | |
3095 | different from also declaring the pointer argument with | |
3096 | attribute nonnull when the function accepts null pointers | |
3097 | only when the corresponding size is zero. */ | |
3098 | if (access.second.internal_p) | |
3099 | { | |
3100 | const std::string argtypestr | |
3101 | = access.second.array_as_string (ptrtype); | |
3102 | ||
3103 | if (warning_at (loc, OPT_Wnonnull, | |
3104 | "argument %i of variable length " | |
3105 | "array %s is null but " | |
3106 | "the corresponding bound argument " | |
3107 | "%i value is %s", | |
3108 | ptridx + 1, argtypestr.c_str (), | |
3109 | sizidx + 1, sizstr)) | |
3110 | arg_warned = OPT_Wnonnull; | |
3111 | } | |
3112 | else if (warning_at (loc, OPT_Wnonnull, | |
3113 | "argument %i is null but " | |
3114 | "the corresponding size argument " | |
3115 | "%i value is %s", | |
3116 | ptridx + 1, sizidx + 1, sizstr)) | |
3117 | arg_warned = OPT_Wnonnull; | |
3118 | } | |
3119 | else if (access_size && access.second.static_p) | |
3120 | { | |
3121 | /* Warn about null pointers for [static N] array arguments | |
3122 | but do not warn for ordinary (i.e., nonstatic) arrays. */ | |
3123 | if (warning_at (loc, OPT_Wnonnull, | |
3124 | "argument %i to %<%T[static %E]%> " | |
3125 | "is null where non-null expected", | |
3126 | ptridx + 1, argtype, access_size)) | |
3127 | arg_warned = OPT_Wnonnull; | |
3128 | } | |
3129 | ||
3130 | if (arg_warned != no_warning) | |
3131 | { | |
3132 | append_attrname (access, attrstr, sizeof attrstr); | |
3133 | /* Remember a warning has been issued and avoid warning | |
3134 | again below for the same attribute. */ | |
3135 | opt_warned = OPT_Wnonnull; | |
3136 | continue; | |
3137 | } | |
3138 | } | |
3139 | ||
9a27acc3 MS |
3140 | access_data data (m_ptr_qry.rvals, stmt, access.second.mode, |
3141 | NULL_TREE, false, NULL_TREE, false); | |
b48d4e68 MS |
3142 | access_ref* const pobj = (access.second.mode == access_write_only |
3143 | ? &data.dst : &data.src); | |
9a27acc3 | 3144 | tree objsize = compute_objsize (ptr, stmt, 1, pobj, &m_ptr_qry); |
b48d4e68 MS |
3145 | |
3146 | /* The size of the destination or source object. */ | |
3147 | tree dstsize = NULL_TREE, srcsize = NULL_TREE; | |
3148 | if (access.second.mode == access_read_only | |
3149 | || access.second.mode == access_none) | |
3150 | { | |
3151 | /* For a read-only argument there is no destination. For | |
3152 | no access, set the source as well and differentiate via | |
3153 | the access flag below. */ | |
3154 | srcsize = objsize; | |
3155 | if (access.second.mode == access_read_only | |
3156 | || access.second.mode == access_none) | |
3157 | { | |
3158 | /* For a read-only attribute there is no destination so | |
3159 | clear OBJSIZE. This emits "reading N bytes" kind of | |
3160 | diagnostics instead of the "writing N bytes" kind, | |
3161 | unless MODE is none. */ | |
3162 | objsize = NULL_TREE; | |
3163 | } | |
3164 | } | |
3165 | else | |
3166 | dstsize = objsize; | |
3167 | ||
3168 | /* Clear the no-warning bit in case it was set by check_access | |
3169 | in a prior iteration so that accesses via different arguments | |
3170 | are diagnosed. */ | |
3171 | suppress_warning (stmt, OPT_Wstringop_overflow_, false); | |
3172 | access_mode mode = data.mode; | |
3173 | if (mode == access_deferred) | |
3174 | mode = TYPE_READONLY (argtype) ? access_read_only : access_read_write; | |
3175 | check_access (stmt, access_size, /*maxread=*/ NULL_TREE, srcsize, | |
9a27acc3 | 3176 | dstsize, mode, &data, m_ptr_qry.rvals); |
b48d4e68 MS |
3177 | |
3178 | if (warning_suppressed_p (stmt, OPT_Wstringop_overflow_)) | |
3179 | opt_warned = OPT_Wstringop_overflow_; | |
3180 | if (opt_warned != no_warning) | |
3181 | { | |
3182 | if (access.second.internal_p) | |
ea9e0d6c MS |
3183 | { |
3184 | unsigned HOST_WIDE_INT nelts = | |
3185 | access_nelts ? access.second.minsize : HOST_WIDE_INT_M1U; | |
3186 | tree arrtype = build_printable_array_type (argtype, nelts); | |
3187 | inform (loc, "referencing argument %u of type %qT", | |
3188 | ptridx + 1, arrtype); | |
3189 | } | |
b48d4e68 MS |
3190 | else |
3191 | /* If check_access issued a warning above, append the relevant | |
3192 | attribute to the string. */ | |
3193 | append_attrname (access, attrstr, sizeof attrstr); | |
3194 | } | |
3195 | } | |
3196 | ||
3197 | if (*attrstr) | |
3198 | { | |
3199 | if (fndecl) | |
3200 | inform (get_location (fndecl), | |
3201 | "in a call to function %qD declared with attribute %qs", | |
3202 | fndecl, attrstr); | |
3203 | else | |
3204 | inform (get_location (stmt), | |
3205 | "in a call with type %qT and attribute %qs", | |
3206 | fntype, attrstr); | |
3207 | } | |
3208 | else if (opt_warned != no_warning) | |
3209 | { | |
3210 | if (fndecl) | |
3211 | inform (get_location (fndecl), | |
3212 | "in a call to function %qD", fndecl); | |
3213 | else | |
3214 | inform (get_location (stmt), | |
3215 | "in a call with type %qT", fntype); | |
3216 | } | |
3217 | ||
3218 | /* Set the bit in case if was cleared and not set above. */ | |
3219 | if (opt_warned != no_warning) | |
3220 | suppress_warning (stmt, opt_warned); | |
3221 | } | |
3222 | ||
3223 | /* Check call STMT to an ordinary (non-built-in) function for invalid | |
3224 | accesses. Return true if a call has been handled. */ | |
3225 | ||
3226 | bool | |
3227 | pass_waccess::check_call (gcall *stmt) | |
3228 | { | |
3229 | tree fntype = gimple_call_fntype (stmt); | |
3230 | if (!fntype) | |
3231 | return false; | |
3232 | ||
3233 | tree fntypeattrs = TYPE_ATTRIBUTES (fntype); | |
3234 | if (!fntypeattrs) | |
3235 | return false; | |
3236 | ||
3237 | /* Map of attribute accewss specifications for function arguments. */ | |
3238 | rdwr_map rdwr_idx; | |
3239 | init_attr_rdwr_indices (&rdwr_idx, fntypeattrs); | |
3240 | ||
3241 | unsigned nargs = call_nargs (stmt); | |
3242 | for (unsigned i = 0; i != nargs; ++i) | |
3243 | { | |
3244 | tree arg = call_arg (stmt, i); | |
3245 | ||
3246 | /* Save the actual argument that corresponds to the access attribute | |
3247 | operand for later processing. */ | |
3248 | if (attr_access *access = rdwr_idx.get (i)) | |
3249 | { | |
3250 | if (POINTER_TYPE_P (TREE_TYPE (arg))) | |
3251 | { | |
3252 | access->ptr = arg; | |
3253 | // A nonnull ACCESS->SIZE contains VLA bounds. */ | |
3254 | } | |
3255 | else | |
3256 | { | |
3257 | access->size = arg; | |
3258 | gcc_assert (access->ptr == NULL_TREE); | |
3259 | } | |
3260 | } | |
3261 | } | |
3262 | ||
3263 | /* Check attribute access arguments. */ | |
3264 | tree fndecl = gimple_call_fndecl (stmt); | |
ece28da9 | 3265 | maybe_check_access_sizes (&rdwr_idx, fndecl, fntype, stmt); |
b48d4e68 MS |
3266 | |
3267 | check_alloc_size_call (stmt); | |
3268 | return true; | |
3269 | } | |
3270 | ||
3271 | /* Check arguments in a call STMT for attribute nonstring. */ | |
3272 | ||
3273 | static void | |
3274 | check_nonstring_args (gcall *stmt) | |
3275 | { | |
3276 | tree fndecl = gimple_call_fndecl (stmt); | |
3277 | ||
3278 | /* Detect passing non-string arguments to functions expecting | |
3279 | nul-terminated strings. */ | |
3280 | maybe_warn_nonstring_arg (fndecl, stmt); | |
3281 | } | |
3282 | ||
ece28da9 MS |
3283 | /* Issue a warning if a deallocation function such as free, realloc, |
3284 | or C++ operator delete is called with an argument not returned by | |
3285 | a matching allocation function such as malloc or the corresponding | |
3286 | form of C++ operatorn new. */ | |
3287 | ||
3288 | void | |
3289 | pass_waccess::maybe_check_dealloc_call (gcall *call) | |
3290 | { | |
3291 | tree fndecl = gimple_call_fndecl (call); | |
3292 | if (!fndecl) | |
3293 | return; | |
3294 | ||
3295 | unsigned argno = fndecl_dealloc_argno (fndecl); | |
3296 | if ((unsigned) call_nargs (call) <= argno) | |
3297 | return; | |
3298 | ||
3299 | tree ptr = gimple_call_arg (call, argno); | |
3300 | if (integer_zerop (ptr)) | |
3301 | return; | |
3302 | ||
3303 | access_ref aref; | |
9a27acc3 | 3304 | if (!compute_objsize (ptr, call, 0, &aref, &m_ptr_qry)) |
ece28da9 MS |
3305 | return; |
3306 | ||
3307 | tree ref = aref.ref; | |
3308 | if (integer_zerop (ref)) | |
3309 | return; | |
3310 | ||
3311 | tree dealloc_decl = fndecl; | |
3312 | location_t loc = gimple_location (call); | |
3313 | ||
3314 | if (DECL_P (ref) || EXPR_P (ref)) | |
3315 | { | |
3316 | /* Diagnose freeing a declared object. */ | |
3317 | if (aref.ref_declared () | |
3318 | && warning_at (loc, OPT_Wfree_nonheap_object, | |
3319 | "%qD called on unallocated object %qD", | |
3320 | dealloc_decl, ref)) | |
3321 | { | |
3322 | inform (get_location (ref), "declared here"); | |
3323 | return; | |
3324 | } | |
3325 | ||
3326 | /* Diagnose freeing a pointer that includes a positive offset. | |
3327 | Such a pointer cannot refer to the beginning of an allocated | |
3328 | object. A negative offset may refer to it. */ | |
3329 | if (aref.sizrng[0] != aref.sizrng[1] | |
3330 | && warn_dealloc_offset (loc, call, aref)) | |
3331 | return; | |
3332 | } | |
3333 | else if (CONSTANT_CLASS_P (ref)) | |
3334 | { | |
3335 | if (warning_at (loc, OPT_Wfree_nonheap_object, | |
3336 | "%qD called on a pointer to an unallocated " | |
3337 | "object %qE", dealloc_decl, ref)) | |
3338 | { | |
3339 | if (TREE_CODE (ptr) == SSA_NAME) | |
3340 | { | |
3341 | gimple *def_stmt = SSA_NAME_DEF_STMT (ptr); | |
3342 | if (is_gimple_assign (def_stmt)) | |
3343 | { | |
3344 | location_t loc = gimple_location (def_stmt); | |
3345 | inform (loc, "assigned here"); | |
3346 | } | |
3347 | } | |
3348 | return; | |
3349 | } | |
3350 | } | |
3351 | else if (TREE_CODE (ref) == SSA_NAME) | |
3352 | { | |
3353 | /* Also warn if the pointer argument refers to the result | |
3354 | of an allocation call like alloca or VLA. */ | |
3355 | gimple *def_stmt = SSA_NAME_DEF_STMT (ref); | |
3356 | if (!def_stmt) | |
3357 | return; | |
3358 | ||
3359 | if (is_gimple_call (def_stmt)) | |
3360 | { | |
3361 | bool warned = false; | |
3362 | if (gimple_call_alloc_p (def_stmt)) | |
3363 | { | |
3364 | if (matching_alloc_calls_p (def_stmt, dealloc_decl)) | |
3365 | { | |
3366 | if (warn_dealloc_offset (loc, call, aref)) | |
3367 | return; | |
3368 | } | |
3369 | else | |
3370 | { | |
3371 | tree alloc_decl = gimple_call_fndecl (def_stmt); | |
3372 | const opt_code opt = | |
3373 | (DECL_IS_OPERATOR_NEW_P (alloc_decl) | |
3374 | || DECL_IS_OPERATOR_DELETE_P (dealloc_decl) | |
3375 | ? OPT_Wmismatched_new_delete | |
3376 | : OPT_Wmismatched_dealloc); | |
3377 | warned = warning_at (loc, opt, | |
3378 | "%qD called on pointer returned " | |
3379 | "from a mismatched allocation " | |
3380 | "function", dealloc_decl); | |
3381 | } | |
3382 | } | |
3383 | else if (gimple_call_builtin_p (def_stmt, BUILT_IN_ALLOCA) | |
3384 | || gimple_call_builtin_p (def_stmt, | |
3385 | BUILT_IN_ALLOCA_WITH_ALIGN)) | |
3386 | warned = warning_at (loc, OPT_Wfree_nonheap_object, | |
3387 | "%qD called on pointer to " | |
3388 | "an unallocated object", | |
3389 | dealloc_decl); | |
3390 | else if (warn_dealloc_offset (loc, call, aref)) | |
3391 | return; | |
3392 | ||
3393 | if (warned) | |
3394 | { | |
3395 | tree fndecl = gimple_call_fndecl (def_stmt); | |
3396 | inform (gimple_location (def_stmt), | |
3397 | "returned from %qD", fndecl); | |
3398 | return; | |
3399 | } | |
3400 | } | |
3401 | else if (gimple_nop_p (def_stmt)) | |
3402 | { | |
3403 | ref = SSA_NAME_VAR (ref); | |
3404 | /* Diagnose freeing a pointer that includes a positive offset. */ | |
3405 | if (TREE_CODE (ref) == PARM_DECL | |
3406 | && !aref.deref | |
3407 | && aref.sizrng[0] != aref.sizrng[1] | |
3408 | && aref.offrng[0] > 0 && aref.offrng[1] > 0 | |
3409 | && warn_dealloc_offset (loc, call, aref)) | |
3410 | return; | |
3411 | } | |
3412 | } | |
3413 | } | |
3414 | ||
2a837de2 MS |
3415 | /* Check call STMT for invalid accesses. */ |
3416 | ||
3417 | void | |
3418 | pass_waccess::check (gcall *stmt) | |
3419 | { | |
b48d4e68 MS |
3420 | if (gimple_call_builtin_p (stmt, BUILT_IN_NORMAL)) |
3421 | check_builtin (stmt); | |
81d6cdd3 | 3422 | |
b48d4e68 MS |
3423 | if (is_gimple_call (stmt)) |
3424 | check_call (stmt); | |
3425 | ||
3426 | maybe_check_dealloc_call (stmt); | |
3427 | ||
3428 | check_nonstring_args (stmt); | |
2a837de2 MS |
3429 | } |
3430 | ||
3431 | /* Check basic block BB for invalid accesses. */ | |
3432 | ||
3433 | void | |
3434 | pass_waccess::check (basic_block bb) | |
3435 | { | |
3436 | /* Iterate over statements, looking for function calls. */ | |
3437 | for (auto si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si)) | |
3438 | { | |
3439 | if (gcall *call = dyn_cast <gcall *> (gsi_stmt (si))) | |
3440 | check (call); | |
3441 | } | |
3442 | } | |
3443 | ||
3444 | /* Check function FUN for invalid accesses. */ | |
3445 | ||
3446 | unsigned | |
3447 | pass_waccess::execute (function *fun) | |
3448 | { | |
81501087 | 3449 | /* Create a new ranger instance and associate it with FUN. */ |
ece28da9 | 3450 | m_ptr_qry.rvals = enable_ranger (fun); |
b48d4e68 | 3451 | |
2a837de2 MS |
3452 | basic_block bb; |
3453 | FOR_EACH_BB_FN (bb, fun) | |
3454 | check (bb); | |
3455 | ||
ece28da9 MS |
3456 | if (dump_file) |
3457 | m_ptr_qry.dump (dump_file, (dump_flags & TDF_DETAILS) != 0); | |
3458 | ||
3459 | m_ptr_qry.flush_cache (); | |
3460 | ||
3461 | /* Release the ranger instance and replace it with a global ranger. | |
3462 | Also reset the pointer since calling disable_ranger() deletes it. */ | |
81501087 | 3463 | disable_ranger (fun); |
ece28da9 | 3464 | m_ptr_qry.rvals = NULL; |
81501087 | 3465 | |
2a837de2 MS |
3466 | return 0; |
3467 | } | |
3468 | ||
3469 | } // namespace | |
3470 | ||
3471 | /* Return a new instance of the pass. */ | |
3472 | ||
3473 | gimple_opt_pass * | |
3474 | make_pass_warn_access (gcc::context *ctxt) | |
3475 | { | |
3476 | return new pass_waccess (ctxt); | |
3477 | } |