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cc8bea0a MS |
1 | /* Pass to detect and issue warnings for violations of the restrict |
2 | qualifier. | |
a5544970 | 3 | Copyright (C) 2017-2019 Free Software Foundation, Inc. |
cc8bea0a MS |
4 | Contributed by Martin Sebor <msebor@redhat.com>. |
5 | ||
6 | This file is part of GCC. | |
7 | ||
8 | GCC is free software; you can redistribute it and/or modify it under | |
9 | the terms of the GNU General Public License as published by the Free | |
10 | Software Foundation; either version 3, or (at your option) any later | |
11 | version. | |
12 | ||
13 | GCC is distributed in the hope that it will be useful, but WITHOUT ANY | |
14 | WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
15 | FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
16 | for more details. | |
17 | ||
18 | You should have received a copy of the GNU General Public License | |
19 | along with GCC; see the file COPYING3. If not see | |
20 | <http://www.gnu.org/licenses/>. */ | |
21 | ||
22 | #include "config.h" | |
23 | #include "system.h" | |
24 | #include "coretypes.h" | |
25 | #include "backend.h" | |
26 | #include "tree.h" | |
27 | #include "gimple.h" | |
28 | #include "domwalk.h" | |
29 | #include "tree-pass.h" | |
30 | #include "builtins.h" | |
31 | #include "ssa.h" | |
32 | #include "gimple-pretty-print.h" | |
33 | #include "gimple-ssa-warn-restrict.h" | |
34 | #include "diagnostic-core.h" | |
35 | #include "fold-const.h" | |
36 | #include "gimple-iterator.h" | |
37 | #include "tree-dfa.h" | |
38 | #include "tree-ssa.h" | |
39 | #include "params.h" | |
40 | #include "tree-cfg.h" | |
41 | #include "tree-object-size.h" | |
42 | #include "calls.h" | |
43 | #include "cfgloop.h" | |
44 | #include "intl.h" | |
45 | ||
46 | namespace { | |
47 | ||
48 | const pass_data pass_data_wrestrict = { | |
49 | GIMPLE_PASS, | |
50 | "wrestrict", | |
51 | OPTGROUP_NONE, | |
52 | TV_NONE, | |
53 | PROP_cfg, /* Properties_required. */ | |
54 | 0, /* properties_provided. */ | |
55 | 0, /* properties_destroyed. */ | |
56 | 0, /* properties_start */ | |
57 | 0, /* properties_finish */ | |
58 | }; | |
59 | ||
60 | /* Pass to detect violations of strict aliasing requirements in calls | |
61 | to built-in string and raw memory functions. */ | |
62 | class pass_wrestrict : public gimple_opt_pass | |
63 | { | |
64 | public: | |
65 | pass_wrestrict (gcc::context *ctxt) | |
66 | : gimple_opt_pass (pass_data_wrestrict, ctxt) | |
67 | { } | |
68 | ||
69 | opt_pass *clone () { return new pass_wrestrict (m_ctxt); } | |
70 | ||
71 | virtual bool gate (function *); | |
72 | virtual unsigned int execute (function *); | |
73 | }; | |
74 | ||
75 | bool | |
76 | pass_wrestrict::gate (function *fun ATTRIBUTE_UNUSED) | |
77 | { | |
287ef129 | 78 | return warn_array_bounds || warn_restrict || warn_stringop_overflow; |
cc8bea0a MS |
79 | } |
80 | ||
81 | /* Class to walk the basic blocks of a function in dominator order. */ | |
82 | class wrestrict_dom_walker : public dom_walker | |
83 | { | |
84 | public: | |
85 | wrestrict_dom_walker () : dom_walker (CDI_DOMINATORS) {} | |
86 | ||
87 | edge before_dom_children (basic_block) FINAL OVERRIDE; | |
88 | bool handle_gimple_call (gimple_stmt_iterator *); | |
89 | ||
90 | private: | |
8a45b051 | 91 | void check_call (gimple *); |
cc8bea0a MS |
92 | }; |
93 | ||
94 | edge | |
95 | wrestrict_dom_walker::before_dom_children (basic_block bb) | |
96 | { | |
97 | /* Iterate over statements, looking for function calls. */ | |
98 | for (gimple_stmt_iterator si = gsi_start_bb (bb); !gsi_end_p (si); | |
99 | gsi_next (&si)) | |
100 | { | |
101 | gimple *stmt = gsi_stmt (si); | |
102 | if (!is_gimple_call (stmt)) | |
103 | continue; | |
104 | ||
8a45b051 | 105 | check_call (stmt); |
cc8bea0a MS |
106 | } |
107 | ||
108 | return NULL; | |
109 | } | |
110 | ||
111 | /* Execute the pass for function FUN, walking in dominator order. */ | |
112 | ||
113 | unsigned | |
114 | pass_wrestrict::execute (function *fun) | |
115 | { | |
116 | calculate_dominance_info (CDI_DOMINATORS); | |
117 | ||
118 | wrestrict_dom_walker walker; | |
119 | walker.walk (ENTRY_BLOCK_PTR_FOR_FN (fun)); | |
120 | ||
121 | return 0; | |
122 | } | |
123 | ||
124 | /* Description of a memory reference by a built-in function. This | |
125 | is similar to ao_ref but made especially suitable for -Wrestrict | |
126 | and not for optimization. */ | |
6c1dae73 | 127 | class builtin_memref |
cc8bea0a | 128 | { |
6c1dae73 | 129 | public: |
cc8bea0a MS |
130 | /* The original pointer argument to the built-in function. */ |
131 | tree ptr; | |
132 | /* The referenced subobject or NULL if not available, and the base | |
133 | object of the memory reference or NULL. */ | |
134 | tree ref; | |
135 | tree base; | |
136 | ||
137 | /* The size of the BASE object, PTRDIFF_MAX if indeterminate, | |
138 | and negative until (possibly lazily) initialized. */ | |
139 | offset_int basesize; | |
140 | ||
141 | /* The non-negative offset of the referenced subobject. Used to avoid | |
142 | warnings for (apparently) possibly but not definitively overlapping | |
143 | accesses to member arrays. Negative when unknown/invalid. */ | |
144 | offset_int refoff; | |
145 | ||
146 | /* The offset range relative to the base. */ | |
147 | offset_int offrange[2]; | |
148 | /* The size range of the access to this reference. */ | |
149 | offset_int sizrange[2]; | |
150 | ||
a411ae9b MS |
151 | /* Cached result of get_max_objsize(). */ |
152 | const offset_int maxobjsize; | |
153 | ||
cc8bea0a MS |
154 | /* True for "bounded" string functions like strncat, and strncpy |
155 | and their variants that specify either an exact or upper bound | |
156 | on the size of the accesses they perform. For strncat both | |
157 | the source and destination references are bounded. For strncpy | |
158 | only the destination reference is. */ | |
159 | bool strbounded_p; | |
160 | ||
161 | builtin_memref (tree, tree); | |
162 | ||
163 | tree offset_out_of_bounds (int, offset_int[2]) const; | |
5e27f0d5 MS |
164 | |
165 | private: | |
166 | ||
167 | /* Ctor helper to set or extend OFFRANGE based on argument. */ | |
168 | void extend_offset_range (tree); | |
169 | ||
170 | /* Ctor helper to determine BASE and OFFRANGE from argument. */ | |
171 | void set_base_and_offset (tree); | |
cc8bea0a MS |
172 | }; |
173 | ||
174 | /* Description of a memory access by a raw memory or string built-in | |
175 | function involving a pair of builtin_memref's. */ | |
176 | class builtin_access | |
177 | { | |
178 | public: | |
179 | /* Destination and source memory reference. */ | |
180 | builtin_memref* const dstref; | |
181 | builtin_memref* const srcref; | |
182 | /* The size range of the access. It's the greater of the accesses | |
183 | to the two references. */ | |
184 | HOST_WIDE_INT sizrange[2]; | |
185 | ||
186 | /* The minimum and maximum offset of an overlap of the access | |
187 | (if it does, in fact, overlap), and the size of the overlap. */ | |
188 | HOST_WIDE_INT ovloff[2]; | |
189 | HOST_WIDE_INT ovlsiz[2]; | |
190 | ||
191 | /* True to consider valid only accesses to the smallest subobject | |
192 | and false for raw memory functions. */ | |
193 | bool strict () const | |
194 | { | |
195 | return detect_overlap != &builtin_access::generic_overlap; | |
196 | } | |
197 | ||
8a45b051 | 198 | builtin_access (gimple *, builtin_memref &, builtin_memref &); |
cc8bea0a MS |
199 | |
200 | /* Entry point to determine overlap. */ | |
201 | bool overlap (); | |
202 | ||
203 | private: | |
204 | /* Implementation functions used to determine overlap. */ | |
205 | bool generic_overlap (); | |
206 | bool strcat_overlap (); | |
207 | bool strcpy_overlap (); | |
208 | ||
209 | bool no_overlap () | |
210 | { | |
211 | return false; | |
212 | } | |
213 | ||
214 | offset_int overlap_size (const offset_int [2], const offset_int[2], | |
215 | offset_int [2]); | |
216 | ||
217 | private: | |
218 | /* Temporaries used to compute the final result. */ | |
219 | offset_int dstoff[2]; | |
220 | offset_int srcoff[2]; | |
221 | offset_int dstsiz[2]; | |
222 | offset_int srcsiz[2]; | |
223 | ||
224 | /* Pointer to a member function to call to determine overlap. */ | |
225 | bool (builtin_access::*detect_overlap) (); | |
226 | }; | |
227 | ||
228 | /* Initialize a memory reference representation from a pointer EXPR and | |
229 | a size SIZE in bytes. If SIZE is NULL_TREE then the size is assumed | |
230 | to be unknown. */ | |
231 | ||
232 | builtin_memref::builtin_memref (tree expr, tree size) | |
233 | : ptr (expr), | |
234 | ref (), | |
235 | base (), | |
236 | basesize (-1), | |
237 | refoff (HOST_WIDE_INT_MIN), | |
238 | offrange (), | |
239 | sizrange (), | |
a411ae9b | 240 | maxobjsize (tree_to_shwi (max_object_size ())), |
cc8bea0a MS |
241 | strbounded_p () |
242 | { | |
243 | /* Unfortunately, wide_int default ctor is a no-op so array members | |
244 | of the type must be set individually. */ | |
245 | offrange[0] = offrange[1] = 0; | |
246 | sizrange[0] = sizrange[1] = 0; | |
247 | ||
a411ae9b MS |
248 | if (!expr) |
249 | return; | |
cc8bea0a | 250 | |
5e27f0d5 MS |
251 | /* Find the BASE object or pointer referenced by EXPR and set |
252 | the offset range OFFRANGE in the process. */ | |
253 | set_base_and_offset (expr); | |
254 | ||
255 | if (size) | |
256 | { | |
257 | tree range[2]; | |
258 | /* Determine the size range, allowing for the result to be [0, 0] | |
259 | for SIZE in the anti-range ~[0, N] where N >= PTRDIFF_MAX. */ | |
260 | get_size_range (size, range, true); | |
261 | sizrange[0] = wi::to_offset (range[0]); | |
262 | sizrange[1] = wi::to_offset (range[1]); | |
263 | /* get_size_range returns SIZE_MAX for the maximum size. | |
264 | Constrain it to the real maximum of PTRDIFF_MAX. */ | |
287ef129 | 265 | if (sizrange[0] <= maxobjsize && sizrange[1] > maxobjsize) |
5e27f0d5 MS |
266 | sizrange[1] = maxobjsize; |
267 | } | |
268 | else | |
269 | sizrange[1] = maxobjsize; | |
270 | ||
7ad491c6 MS |
271 | if (!DECL_P (base)) |
272 | return; | |
273 | ||
274 | /* If the offset could be in the range of the referenced object | |
275 | constrain its bounds so neither exceeds those of the object. */ | |
276 | if (offrange[0] < 0 && offrange[1] > 0) | |
277 | offrange[0] = 0; | |
278 | ||
279 | offset_int maxoff = maxobjsize; | |
5e27f0d5 | 280 | tree basetype = TREE_TYPE (base); |
1486eb79 MS |
281 | if (TREE_CODE (basetype) == ARRAY_TYPE) |
282 | { | |
283 | if (ref && array_at_struct_end_p (ref)) | |
284 | ; /* Use the maximum possible offset for last member arrays. */ | |
285 | else if (tree basesize = TYPE_SIZE_UNIT (basetype)) | |
286 | if (TREE_CODE (basesize) == INTEGER_CST) | |
287 | /* Size could be non-constant for a variable-length type such | |
288 | as a struct with a VLA member (a GCC extension). */ | |
289 | maxoff = wi::to_offset (basesize); | |
290 | } | |
7ad491c6 MS |
291 | |
292 | if (offrange[0] >= 0) | |
5e27f0d5 | 293 | { |
7ad491c6 MS |
294 | if (offrange[1] < 0) |
295 | offrange[1] = offrange[0] <= maxoff ? maxoff : maxobjsize; | |
296 | else if (offrange[0] <= maxoff && offrange[1] > maxoff) | |
297 | offrange[1] = maxoff; | |
5e27f0d5 MS |
298 | } |
299 | } | |
300 | ||
a411ae9b MS |
301 | /* Ctor helper to set or extend OFFRANGE based on the OFFSET argument. |
302 | Pointer offsets are represented as unsigned sizetype but must be | |
303 | treated as signed. */ | |
5e27f0d5 MS |
304 | |
305 | void | |
306 | builtin_memref::extend_offset_range (tree offset) | |
307 | { | |
5e27f0d5 MS |
308 | if (TREE_CODE (offset) == INTEGER_CST) |
309 | { | |
310 | offset_int off = int_cst_value (offset); | |
311 | if (off != 0) | |
312 | { | |
313 | offrange[0] += off; | |
314 | offrange[1] += off; | |
315 | } | |
316 | return; | |
317 | } | |
318 | ||
319 | if (TREE_CODE (offset) == SSA_NAME) | |
320 | { | |
a411ae9b MS |
321 | /* A pointer offset is represented as sizetype but treated |
322 | as signed. */ | |
5e27f0d5 | 323 | wide_int min, max; |
54994253 | 324 | value_range_kind rng = get_range_info (offset, &min, &max); |
a411ae9b MS |
325 | if (rng == VR_ANTI_RANGE && wi::lts_p (max, min)) |
326 | { | |
327 | /* Convert an anti-range whose upper bound is less than | |
328 | its lower bound to a signed range. */ | |
329 | offrange[0] += offset_int::from (max + 1, SIGNED); | |
330 | offrange[1] += offset_int::from (min - 1, SIGNED); | |
331 | return; | |
332 | } | |
333 | ||
334 | if (rng == VR_RANGE | |
335 | && (DECL_P (base) || wi::lts_p (min, max))) | |
5e27f0d5 | 336 | { |
a411ae9b MS |
337 | /* Preserve the bounds of the range for an offset into |
338 | a known object (it may be adjusted later relative to | |
339 | a constant offset from its beginning). Otherwise use | |
340 | the bounds only when they are ascending when treated | |
341 | as signed. */ | |
5e27f0d5 MS |
342 | offrange[0] += offset_int::from (min, SIGNED); |
343 | offrange[1] += offset_int::from (max, SIGNED); | |
a411ae9b | 344 | return; |
5e27f0d5 | 345 | } |
a411ae9b MS |
346 | |
347 | /* Handle an anti-range the same as no range at all. */ | |
348 | gimple *stmt = SSA_NAME_DEF_STMT (offset); | |
349 | tree type; | |
350 | if (is_gimple_assign (stmt) | |
351 | && (type = TREE_TYPE (gimple_assign_rhs1 (stmt))) | |
352 | && INTEGRAL_TYPE_P (type)) | |
5e27f0d5 | 353 | { |
a411ae9b MS |
354 | tree_code code = gimple_assign_rhs_code (stmt); |
355 | if (code == NOP_EXPR) | |
5e27f0d5 MS |
356 | { |
357 | /* Use the bounds of the type of the NOP_EXPR operand | |
358 | even if it's signed. The result doesn't trigger | |
359 | warnings but makes their output more readable. */ | |
360 | offrange[0] += wi::to_offset (TYPE_MIN_VALUE (type)); | |
361 | offrange[1] += wi::to_offset (TYPE_MAX_VALUE (type)); | |
a411ae9b | 362 | return; |
5e27f0d5 | 363 | } |
5e27f0d5 | 364 | } |
5e27f0d5 MS |
365 | } |
366 | ||
a411ae9b MS |
367 | const offset_int maxoff = tree_to_shwi (max_object_size ()) >> 1; |
368 | const offset_int minoff = -maxoff - 1; | |
369 | ||
370 | offrange[0] += minoff; | |
371 | offrange[1] += maxoff; | |
5e27f0d5 MS |
372 | } |
373 | ||
374 | /* Determines the base object or pointer of the reference EXPR | |
375 | and the offset range from the beginning of the base. */ | |
376 | ||
377 | void | |
378 | builtin_memref::set_base_and_offset (tree expr) | |
379 | { | |
a411ae9b | 380 | tree offset = NULL_TREE; |
5e27f0d5 | 381 | |
cc8bea0a MS |
382 | if (TREE_CODE (expr) == SSA_NAME) |
383 | { | |
384 | /* Try to tease the offset out of the pointer. */ | |
385 | gimple *stmt = SSA_NAME_DEF_STMT (expr); | |
5e27f0d5 MS |
386 | if (!base |
387 | && gimple_assign_single_p (stmt) | |
cc8bea0a MS |
388 | && gimple_assign_rhs_code (stmt) == ADDR_EXPR) |
389 | expr = gimple_assign_rhs1 (stmt); | |
390 | else if (is_gimple_assign (stmt)) | |
391 | { | |
392 | tree_code code = gimple_assign_rhs_code (stmt); | |
393 | if (code == NOP_EXPR) | |
394 | { | |
395 | tree rhs = gimple_assign_rhs1 (stmt); | |
396 | if (POINTER_TYPE_P (TREE_TYPE (rhs))) | |
397 | expr = gimple_assign_rhs1 (stmt); | |
5e27f0d5 MS |
398 | else |
399 | { | |
400 | base = expr; | |
401 | return; | |
402 | } | |
cc8bea0a MS |
403 | } |
404 | else if (code == POINTER_PLUS_EXPR) | |
405 | { | |
406 | expr = gimple_assign_rhs1 (stmt); | |
a411ae9b | 407 | offset = gimple_assign_rhs2 (stmt); |
cc8bea0a | 408 | } |
5e27f0d5 MS |
409 | else |
410 | { | |
411 | base = expr; | |
412 | return; | |
413 | } | |
414 | } | |
415 | else | |
416 | { | |
a411ae9b MS |
417 | /* FIXME: Handle PHI nodes in case like: |
418 | _12 = &MEM[(void *)&a + 2B] + _10; | |
419 | ||
420 | <bb> [local count: 1073741824]: | |
421 | # prephitmp_13 = PHI <_12, &MEM[(void *)&a + 2B]> | |
422 | memcpy (prephitmp_13, p_7(D), 6); */ | |
5e27f0d5 MS |
423 | base = expr; |
424 | return; | |
cc8bea0a MS |
425 | } |
426 | } | |
427 | ||
428 | if (TREE_CODE (expr) == ADDR_EXPR) | |
5e27f0d5 | 429 | expr = TREE_OPERAND (expr, 0); |
cc8bea0a | 430 | |
8286793a MS |
431 | /* Stash the reference for offset validation. */ |
432 | ref = expr; | |
433 | ||
5e27f0d5 MS |
434 | poly_int64 bitsize, bitpos; |
435 | tree var_off; | |
436 | machine_mode mode; | |
437 | int sign, reverse, vol; | |
cc8bea0a | 438 | |
5e27f0d5 MS |
439 | /* Determine the base object or pointer of the reference and |
440 | the constant bit offset from the beginning of the base. | |
441 | If the offset has a non-constant component, it will be in | |
442 | VAR_OFF. MODE, SIGN, REVERSE, and VOL are write only and | |
443 | unused here. */ | |
444 | base = get_inner_reference (expr, &bitsize, &bitpos, &var_off, | |
445 | &mode, &sign, &reverse, &vol); | |
cc8bea0a | 446 | |
8286793a MS |
447 | /* get_inner_reference is not expected to return null. */ |
448 | gcc_assert (base != NULL); | |
449 | ||
a411ae9b MS |
450 | if (offset) |
451 | extend_offset_range (offset); | |
452 | ||
5e27f0d5 | 453 | poly_int64 bytepos = exact_div (bitpos, BITS_PER_UNIT); |
cc8bea0a | 454 | |
ce811fc4 | 455 | /* Convert the poly_int64 offset to offset_int. The offset |
8286793a MS |
456 | should be constant but be prepared for it not to be just in |
457 | case. */ | |
458 | offset_int cstoff; | |
459 | if (bytepos.is_constant (&cstoff)) | |
5e27f0d5 | 460 | { |
8286793a MS |
461 | offrange[0] += cstoff; |
462 | offrange[1] += cstoff; | |
cc8bea0a | 463 | |
8286793a MS |
464 | /* Besides the reference saved above, also stash the offset |
465 | for validation. */ | |
466 | if (TREE_CODE (expr) == COMPONENT_REF) | |
467 | refoff = cstoff; | |
468 | } | |
469 | else | |
470 | offrange[1] += maxobjsize; | |
cc8bea0a | 471 | |
5e27f0d5 | 472 | if (var_off) |
cc8bea0a | 473 | { |
5e27f0d5 | 474 | if (TREE_CODE (var_off) == INTEGER_CST) |
aca52e6f | 475 | { |
8286793a | 476 | cstoff = wi::to_offset (var_off); |
5e27f0d5 MS |
477 | offrange[0] += cstoff; |
478 | offrange[1] += cstoff; | |
aca52e6f RS |
479 | } |
480 | else | |
5e27f0d5 | 481 | offrange[1] += maxobjsize; |
cc8bea0a MS |
482 | } |
483 | ||
5e27f0d5 | 484 | if (TREE_CODE (base) == MEM_REF) |
816fad6e | 485 | { |
5e27f0d5 MS |
486 | tree memrefoff = TREE_OPERAND (base, 1); |
487 | extend_offset_range (memrefoff); | |
488 | base = TREE_OPERAND (base, 0); | |
816fad6e MS |
489 | } |
490 | ||
5e27f0d5 MS |
491 | if (TREE_CODE (base) == SSA_NAME) |
492 | set_base_and_offset (base); | |
cc8bea0a MS |
493 | } |
494 | ||
495 | /* Return error_mark_node if the signed offset exceeds the bounds | |
496 | of the address space (PTRDIFF_MAX). Otherwise, return either | |
497 | BASE or REF when the offset exceeds the bounds of the BASE or | |
498 | REF object, and set OOBOFF to the past-the-end offset formed | |
499 | by the reference, including its size. When STRICT is non-zero | |
500 | use REF size, when available, otherwise use BASE size. When | |
501 | STRICT is greater than 1, use the size of the last array member | |
502 | as the bound, otherwise treat such a member as a flexible array | |
503 | member. Return NULL when the offset is in bounds. */ | |
504 | ||
505 | tree | |
506 | builtin_memref::offset_out_of_bounds (int strict, offset_int ooboff[2]) const | |
507 | { | |
a411ae9b MS |
508 | if (!ptr) |
509 | return NULL_TREE; | |
cc8bea0a MS |
510 | |
511 | /* A temporary, possibly adjusted, copy of the offset range. */ | |
512 | offset_int offrng[2] = { offrange[0], offrange[1] }; | |
513 | ||
514 | if (DECL_P (base) && TREE_CODE (TREE_TYPE (base)) == ARRAY_TYPE) | |
515 | { | |
56735d40 MS |
516 | /* Check for offset in an anti-range with a negative lower bound. |
517 | For such a range, consider only the non-negative subrange. */ | |
518 | if (offrng[1] < offrng[0] && offrng[1] < 0) | |
cc8bea0a MS |
519 | offrng[1] = maxobjsize; |
520 | } | |
521 | ||
522 | /* Conservative offset of the last byte of the referenced object. */ | |
523 | offset_int endoff; | |
524 | ||
525 | /* The bounds need not be ordered. Set HIB to use as the index | |
526 | of the larger of the bounds and LOB as the opposite. */ | |
527 | bool hib = wi::les_p (offrng[0], offrng[1]); | |
528 | bool lob = !hib; | |
529 | ||
530 | if (basesize < 0) | |
531 | { | |
532 | endoff = offrng[lob] + sizrange[0]; | |
533 | ||
534 | /* For a reference through a pointer to an object of unknown size | |
535 | all initial offsets are considered valid, positive as well as | |
536 | negative, since the pointer itself can point past the beginning | |
537 | of the object. However, the sum of the lower bound of the offset | |
538 | and that of the size must be less than or equal than PTRDIFF_MAX. */ | |
539 | if (endoff > maxobjsize) | |
540 | return error_mark_node; | |
541 | ||
542 | return NULL_TREE; | |
543 | } | |
544 | ||
545 | /* A reference to an object of known size must be within the bounds | |
546 | of the base object. */ | |
547 | if (offrng[hib] < 0 || offrng[lob] > basesize) | |
548 | return base; | |
549 | ||
550 | /* The extent of the reference must also be within the bounds of | |
551 | the base object (if known) or the maximum object size otherwise. */ | |
552 | endoff = wi::smax (offrng[lob], 0) + sizrange[0]; | |
553 | if (endoff > maxobjsize) | |
554 | return error_mark_node; | |
555 | ||
556 | offset_int size = basesize; | |
557 | tree obj = base; | |
558 | ||
559 | if (strict | |
560 | && DECL_P (obj) | |
561 | && ref | |
562 | && refoff >= 0 | |
563 | && TREE_CODE (ref) == COMPONENT_REF | |
564 | && (strict > 1 | |
565 | || !array_at_struct_end_p (ref))) | |
566 | { | |
567 | /* If the reference is to a member subobject, the offset must | |
568 | be within the bounds of the subobject. */ | |
569 | tree field = TREE_OPERAND (ref, 1); | |
570 | tree type = TREE_TYPE (field); | |
571 | if (tree sz = TYPE_SIZE_UNIT (type)) | |
572 | if (TREE_CODE (sz) == INTEGER_CST) | |
573 | { | |
574 | size = refoff + wi::to_offset (sz); | |
575 | obj = ref; | |
576 | } | |
577 | } | |
578 | ||
579 | if (endoff <= size) | |
580 | return NULL_TREE; | |
581 | ||
582 | /* Set the out-of-bounds offset range to be one greater than | |
583 | that delimited by the reference including its size. */ | |
584 | ooboff[lob] = size + 1; | |
585 | ||
586 | if (endoff > ooboff[lob]) | |
587 | ooboff[hib] = endoff; | |
588 | else | |
589 | ooboff[hib] = wi::smax (offrng[lob], 0) + sizrange[1]; | |
590 | ||
591 | return obj; | |
592 | } | |
593 | ||
594 | /* Create an association between the memory references DST and SRC | |
595 | for access by a call EXPR to a memory or string built-in funtion. */ | |
596 | ||
8a45b051 | 597 | builtin_access::builtin_access (gimple *call, builtin_memref &dst, |
cc8bea0a MS |
598 | builtin_memref &src) |
599 | : dstref (&dst), srcref (&src), sizrange (), ovloff (), ovlsiz (), | |
600 | dstoff (), srcoff (), dstsiz (), srcsiz () | |
601 | { | |
602 | /* Zero out since the offset_int ctors invoked above are no-op. */ | |
603 | dstoff[0] = dstoff[1] = 0; | |
604 | srcoff[0] = srcoff[1] = 0; | |
605 | dstsiz[0] = dstsiz[1] = 0; | |
606 | srcsiz[0] = srcsiz[1] = 0; | |
607 | ||
608 | /* Object Size Type to use to determine the size of the destination | |
609 | and source objects. Overridden below for raw memory functions. */ | |
610 | int ostype = 1; | |
611 | ||
612 | /* True when the size of one reference depends on the offset of | |
613 | itself or the other. */ | |
614 | bool depends_p = true; | |
615 | ||
616 | /* True when the size of the destination reference DSTREF has been | |
617 | determined from SRCREF and so needs to be adjusted by the latter's | |
618 | offset. Only meaningful for bounded string functions like strncpy. */ | |
619 | bool dstadjust_p = false; | |
620 | ||
621 | /* The size argument number (depends on the built-in). */ | |
622 | unsigned sizeargno = 2; | |
cc8bea0a MS |
623 | |
624 | tree func = gimple_call_fndecl (call); | |
625 | switch (DECL_FUNCTION_CODE (func)) | |
626 | { | |
627 | case BUILT_IN_MEMCPY: | |
628 | case BUILT_IN_MEMCPY_CHK: | |
cc8bea0a MS |
629 | case BUILT_IN_MEMPCPY: |
630 | case BUILT_IN_MEMPCPY_CHK: | |
cc8bea0a MS |
631 | ostype = 0; |
632 | depends_p = false; | |
633 | detect_overlap = &builtin_access::generic_overlap; | |
634 | break; | |
635 | ||
636 | case BUILT_IN_MEMMOVE: | |
637 | case BUILT_IN_MEMMOVE_CHK: | |
cc8bea0a MS |
638 | /* For memmove there is never any overlap to check for. */ |
639 | ostype = 0; | |
640 | depends_p = false; | |
641 | detect_overlap = &builtin_access::no_overlap; | |
642 | break; | |
643 | ||
a411ae9b MS |
644 | case BUILT_IN_MEMSET: |
645 | case BUILT_IN_MEMSET_CHK: | |
646 | /* For memset there is never any overlap to check for. */ | |
647 | ostype = 0; | |
648 | depends_p = false; | |
649 | detect_overlap = &builtin_access::no_overlap; | |
650 | break; | |
651 | ||
cc8bea0a MS |
652 | case BUILT_IN_STPNCPY: |
653 | case BUILT_IN_STPNCPY_CHK: | |
654 | case BUILT_IN_STRNCPY: | |
655 | case BUILT_IN_STRNCPY_CHK: | |
656 | dstref->strbounded_p = true; | |
657 | detect_overlap = &builtin_access::strcpy_overlap; | |
658 | break; | |
659 | ||
660 | case BUILT_IN_STPCPY: | |
661 | case BUILT_IN_STPCPY_CHK: | |
cc8bea0a MS |
662 | case BUILT_IN_STRCPY: |
663 | case BUILT_IN_STRCPY_CHK: | |
cc8bea0a MS |
664 | detect_overlap = &builtin_access::strcpy_overlap; |
665 | break; | |
666 | ||
667 | case BUILT_IN_STRCAT: | |
668 | case BUILT_IN_STRCAT_CHK: | |
cc8bea0a MS |
669 | detect_overlap = &builtin_access::strcat_overlap; |
670 | break; | |
671 | ||
672 | case BUILT_IN_STRNCAT: | |
673 | case BUILT_IN_STRNCAT_CHK: | |
674 | dstref->strbounded_p = true; | |
675 | srcref->strbounded_p = true; | |
676 | detect_overlap = &builtin_access::strcat_overlap; | |
677 | break; | |
678 | ||
679 | default: | |
680 | /* Handle other string functions here whose access may need | |
681 | to be validated for in-bounds offsets and non-overlapping | |
31db0fe0 | 682 | copies. */ |
cc8bea0a MS |
683 | return; |
684 | } | |
685 | ||
a411ae9b | 686 | const offset_int maxobjsize = dst.maxobjsize; |
cc8bea0a MS |
687 | |
688 | /* Try to determine the size of the base object. compute_objsize | |
689 | expects a pointer so create one if BASE is a non-pointer object. */ | |
690 | tree addr; | |
691 | if (dst.basesize < 0) | |
692 | { | |
693 | addr = dst.base; | |
694 | if (!POINTER_TYPE_P (TREE_TYPE (addr))) | |
695 | addr = build1 (ADDR_EXPR, (TREE_TYPE (addr)), addr); | |
696 | ||
697 | if (tree dstsize = compute_objsize (addr, ostype)) | |
698 | dst.basesize = wi::to_offset (dstsize); | |
699 | else if (POINTER_TYPE_P (TREE_TYPE (addr))) | |
700 | dst.basesize = HOST_WIDE_INT_MIN; | |
701 | else | |
702 | dst.basesize = maxobjsize; | |
703 | } | |
704 | ||
a411ae9b | 705 | if (src.base && src.basesize < 0) |
cc8bea0a MS |
706 | { |
707 | addr = src.base; | |
708 | if (!POINTER_TYPE_P (TREE_TYPE (addr))) | |
709 | addr = build1 (ADDR_EXPR, (TREE_TYPE (addr)), addr); | |
710 | ||
711 | if (tree srcsize = compute_objsize (addr, ostype)) | |
712 | src.basesize = wi::to_offset (srcsize); | |
713 | else if (POINTER_TYPE_P (TREE_TYPE (addr))) | |
714 | src.basesize = HOST_WIDE_INT_MIN; | |
715 | else | |
716 | src.basesize = maxobjsize; | |
717 | } | |
718 | ||
719 | /* If there is no dependency between the references or the base | |
720 | objects of the two references aren't the same there's nothing | |
721 | else to do. */ | |
722 | if (depends_p && dstref->base != srcref->base) | |
723 | return; | |
724 | ||
725 | /* ...otherwise, make adjustments for references to the same object | |
726 | by string built-in functions to reflect the constraints imposed | |
727 | by the function. */ | |
728 | ||
729 | /* For bounded string functions determine the range of the bound | |
730 | on the access. For others, the range stays unbounded. */ | |
731 | offset_int bounds[2] = { maxobjsize, maxobjsize }; | |
732 | if (dstref->strbounded_p) | |
733 | { | |
9a0cbb60 MS |
734 | unsigned nargs = gimple_call_num_args (call); |
735 | if (nargs <= sizeargno) | |
736 | return; | |
737 | ||
cc8bea0a MS |
738 | tree size = gimple_call_arg (call, sizeargno); |
739 | tree range[2]; | |
740 | if (get_size_range (size, range, true)) | |
741 | { | |
742 | bounds[0] = wi::to_offset (range[0]); | |
743 | bounds[1] = wi::to_offset (range[1]); | |
744 | } | |
745 | ||
746 | /* If both references' size ranges are indeterminate use the last | |
747 | (size) argument from the function call as a substitute. This | |
748 | may only be necessary for strncpy (but not for memcpy where | |
749 | the size range would have been already determined this way). */ | |
750 | if (dstref->sizrange[0] == 0 && dstref->sizrange[1] == maxobjsize | |
751 | && srcref->sizrange[0] == 0 && srcref->sizrange[1] == maxobjsize) | |
752 | { | |
753 | dstref->sizrange[0] = bounds[0]; | |
754 | dstref->sizrange[1] = bounds[1]; | |
755 | } | |
756 | } | |
757 | ||
758 | /* The size range of one reference involving the same base object | |
759 | can be determined from the size range of the other reference. | |
760 | This makes it possible to compute accurate offsets for warnings | |
761 | involving functions like strcpy where the length of just one of | |
762 | the two arguments is known (determined by tree-ssa-strlen). */ | |
763 | if (dstref->sizrange[0] == 0 && dstref->sizrange[1] == maxobjsize) | |
764 | { | |
765 | /* When the destination size is unknown set it to the size of | |
766 | the source. */ | |
767 | dstref->sizrange[0] = srcref->sizrange[0]; | |
768 | dstref->sizrange[1] = srcref->sizrange[1]; | |
769 | } | |
770 | else if (srcref->sizrange[0] == 0 && srcref->sizrange[1] == maxobjsize) | |
771 | { | |
772 | /* When the source size is unknown set it to the size of | |
773 | the destination. */ | |
774 | srcref->sizrange[0] = dstref->sizrange[0]; | |
775 | srcref->sizrange[1] = dstref->sizrange[1]; | |
776 | ||
777 | if (depends_p) | |
778 | { | |
779 | if (dstref->strbounded_p) | |
780 | { | |
781 | /* Read access by strncpy is bounded. */ | |
782 | if (bounds[0] < srcref->sizrange[0]) | |
783 | srcref->sizrange[0] = bounds[0]; | |
784 | if (bounds[1] < srcref->sizrange[1]) | |
785 | srcref->sizrange[1] = bounds[1]; | |
786 | } | |
787 | ||
788 | /* For string functions, adjust the size range of the source | |
789 | reference by the inverse boundaries of the offset (because | |
c7c9468a | 790 | the higher the offset into the string the shorter its |
cc8bea0a | 791 | length). */ |
c7c9468a JL |
792 | if (srcref->offrange[1] >= 0 |
793 | && srcref->offrange[1] < srcref->sizrange[0]) | |
cc8bea0a MS |
794 | srcref->sizrange[0] -= srcref->offrange[1]; |
795 | else | |
796 | srcref->sizrange[0] = 0; | |
797 | ||
798 | if (srcref->offrange[0] > 0) | |
799 | { | |
800 | if (srcref->offrange[0] < srcref->sizrange[1]) | |
801 | srcref->sizrange[1] -= srcref->offrange[0]; | |
802 | else | |
803 | srcref->sizrange[1] = 0; | |
804 | } | |
805 | ||
806 | dstadjust_p = true; | |
807 | } | |
808 | } | |
809 | ||
810 | if (detect_overlap == &builtin_access::generic_overlap) | |
811 | { | |
812 | if (dstref->strbounded_p) | |
813 | { | |
814 | dstref->sizrange[0] = bounds[0]; | |
815 | dstref->sizrange[1] = bounds[1]; | |
816 | ||
817 | if (dstref->sizrange[0] < srcref->sizrange[0]) | |
818 | srcref->sizrange[0] = dstref->sizrange[0]; | |
819 | ||
820 | if (dstref->sizrange[1] < srcref->sizrange[1]) | |
821 | srcref->sizrange[1] = dstref->sizrange[1]; | |
822 | } | |
823 | } | |
824 | else if (detect_overlap == &builtin_access::strcpy_overlap) | |
825 | { | |
826 | if (!dstref->strbounded_p) | |
827 | { | |
828 | /* For strcpy, adjust the destination size range to match that | |
829 | of the source computed above. */ | |
830 | if (depends_p && dstadjust_p) | |
831 | { | |
832 | dstref->sizrange[0] = srcref->sizrange[0]; | |
833 | dstref->sizrange[1] = srcref->sizrange[1]; | |
834 | } | |
835 | } | |
836 | } | |
837 | ||
838 | if (dstref->strbounded_p) | |
839 | { | |
840 | /* For strncpy, adjust the destination size range to match that | |
841 | of the source computed above. */ | |
842 | dstref->sizrange[0] = bounds[0]; | |
843 | dstref->sizrange[1] = bounds[1]; | |
844 | ||
845 | if (bounds[0] < srcref->sizrange[0]) | |
846 | srcref->sizrange[0] = bounds[0]; | |
847 | ||
848 | if (bounds[1] < srcref->sizrange[1]) | |
849 | srcref->sizrange[1] = bounds[1]; | |
850 | } | |
851 | } | |
852 | ||
853 | offset_int | |
854 | builtin_access::overlap_size (const offset_int a[2], const offset_int b[2], | |
855 | offset_int *off) | |
856 | { | |
857 | const offset_int *p = a; | |
858 | const offset_int *q = b; | |
859 | ||
860 | /* Point P at the bigger of the two ranges and Q at the smaller. */ | |
861 | if (wi::lts_p (a[1] - a[0], b[1] - b[0])) | |
862 | { | |
863 | p = b; | |
864 | q = a; | |
865 | } | |
866 | ||
867 | if (p[0] < q[0]) | |
868 | { | |
869 | if (p[1] < q[0]) | |
870 | return 0; | |
871 | ||
872 | *off = q[0]; | |
873 | return wi::smin (p[1], q[1]) - q[0]; | |
874 | } | |
875 | ||
876 | if (q[1] < p[0]) | |
877 | return 0; | |
878 | ||
879 | off[0] = p[0]; | |
880 | return q[1] - p[0]; | |
881 | } | |
882 | ||
883 | /* Return true if the bounded mempry (memcpy amd similar) or string function | |
884 | access (strncpy and similar) ACS overlaps. */ | |
885 | ||
886 | bool | |
887 | builtin_access::generic_overlap () | |
888 | { | |
889 | builtin_access &acs = *this; | |
890 | const builtin_memref *dstref = acs.dstref; | |
891 | const builtin_memref *srcref = acs.srcref; | |
892 | ||
893 | gcc_assert (dstref->base == srcref->base); | |
894 | ||
a411ae9b | 895 | const offset_int maxobjsize = acs.dstref->maxobjsize; |
cc8bea0a MS |
896 | |
897 | offset_int maxsize = dstref->basesize < 0 ? maxobjsize : dstref->basesize; | |
898 | gcc_assert (maxsize <= maxobjsize); | |
899 | ||
900 | /* Adjust the larger bounds of the offsets (which may be the first | |
901 | element if the lower bound is larger than the upper bound) to | |
902 | make them valid for the smallest access (if possible) but no smaller | |
903 | than the smaller bounds. */ | |
904 | gcc_assert (wi::les_p (acs.dstoff[0], acs.dstoff[1])); | |
905 | ||
906 | if (maxsize < acs.dstoff[1] + acs.dstsiz[0]) | |
907 | acs.dstoff[1] = maxsize - acs.dstsiz[0]; | |
908 | if (acs.dstoff[1] < acs.dstoff[0]) | |
909 | acs.dstoff[1] = acs.dstoff[0]; | |
910 | ||
911 | gcc_assert (wi::les_p (acs.srcoff[0], acs.srcoff[1])); | |
912 | ||
913 | if (maxsize < acs.srcoff[1] + acs.srcsiz[0]) | |
914 | acs.srcoff[1] = maxsize - acs.srcsiz[0]; | |
915 | if (acs.srcoff[1] < acs.srcoff[0]) | |
916 | acs.srcoff[1] = acs.srcoff[0]; | |
917 | ||
918 | /* Determine the minimum and maximum space for the access given | |
919 | the offsets. */ | |
920 | offset_int space[2]; | |
921 | space[0] = wi::abs (acs.dstoff[0] - acs.srcoff[0]); | |
922 | space[1] = space[0]; | |
923 | ||
924 | offset_int d = wi::abs (acs.dstoff[0] - acs.srcoff[1]); | |
925 | if (acs.srcsiz[0] > 0) | |
926 | { | |
927 | if (d < space[0]) | |
928 | space[0] = d; | |
929 | ||
930 | if (space[1] < d) | |
931 | space[1] = d; | |
932 | } | |
933 | else | |
934 | space[1] = acs.dstsiz[1]; | |
935 | ||
936 | d = wi::abs (acs.dstoff[1] - acs.srcoff[0]); | |
937 | if (d < space[0]) | |
938 | space[0] = d; | |
939 | ||
940 | if (space[1] < d) | |
941 | space[1] = d; | |
942 | ||
943 | /* Treat raw memory functions both of whose references are bounded | |
944 | as special and permit uncertain overlaps to go undetected. For | |
945 | all kinds of constant offset and constant size accesses, if | |
946 | overlap isn't certain it is not possible. */ | |
947 | bool overlap_possible = space[0] < acs.dstsiz[1]; | |
948 | if (!overlap_possible) | |
949 | return false; | |
950 | ||
951 | bool overlap_certain = space[1] < acs.dstsiz[0]; | |
952 | ||
953 | /* True when the size of one reference depends on the offset of | |
954 | the other. */ | |
955 | bool depends_p = detect_overlap != &builtin_access::generic_overlap; | |
956 | ||
5e27f0d5 MS |
957 | if (!overlap_certain) |
958 | { | |
959 | if (!dstref->strbounded_p && !depends_p) | |
8286793a | 960 | /* Memcpy only considers certain overlap. */ |
5e27f0d5 MS |
961 | return false; |
962 | ||
963 | /* There's no way to distinguish an access to the same member | |
964 | of a structure from one to two distinct members of the same | |
965 | structure. Give up to avoid excessive false positives. */ | |
8286793a MS |
966 | tree basetype = TREE_TYPE (dstref->base); |
967 | ||
968 | if (POINTER_TYPE_P (basetype)) | |
969 | basetype = TREE_TYPE (basetype); | |
970 | else | |
971 | while (TREE_CODE (basetype) == ARRAY_TYPE) | |
972 | basetype = TREE_TYPE (basetype); | |
973 | ||
5e27f0d5 MS |
974 | if (RECORD_OR_UNION_TYPE_P (basetype)) |
975 | return false; | |
976 | } | |
cc8bea0a MS |
977 | |
978 | /* True for stpcpy and strcpy. */ | |
979 | bool stxcpy_p = (!dstref->strbounded_p | |
980 | && detect_overlap == &builtin_access::strcpy_overlap); | |
981 | ||
982 | if (dstref->refoff >= 0 | |
983 | && srcref->refoff >= 0 | |
984 | && dstref->refoff != srcref->refoff | |
985 | && (stxcpy_p || dstref->strbounded_p || srcref->strbounded_p)) | |
986 | return false; | |
987 | ||
988 | offset_int siz[2] = { maxobjsize + 1, 0 }; | |
989 | ||
990 | ovloff[0] = HOST_WIDE_INT_MAX; | |
991 | ovloff[1] = HOST_WIDE_INT_MIN; | |
992 | ||
993 | /* Adjustment to the lower bound of the offset of the overlap to | |
994 | account for a subset of unbounded string calls where the size | |
995 | of the destination string depends on the length of the source | |
996 | which in turn depends on the offset into it. */ | |
997 | bool sub1; | |
998 | ||
999 | if (stxcpy_p) | |
1000 | { | |
1001 | sub1 = acs.dstoff[0] <= acs.srcoff[0]; | |
1002 | ||
1003 | /* Iterate over the extreme locations (on the horizontal axis formed | |
1004 | by their offsets) and sizes of two regions and find their smallest | |
1005 | and largest overlap and the corresponding offsets. */ | |
1006 | for (unsigned i = 0; i != 2; ++i) | |
1007 | { | |
1008 | const offset_int a[2] = { | |
1009 | acs.dstoff[i], acs.dstoff[i] + acs.dstsiz[!i] | |
1010 | }; | |
1011 | ||
1012 | const offset_int b[2] = { | |
1013 | acs.srcoff[i], acs.srcoff[i] + acs.srcsiz[!i] | |
1014 | }; | |
1015 | ||
1016 | offset_int off; | |
1017 | offset_int sz = overlap_size (a, b, &off); | |
1018 | if (sz < siz[0]) | |
1019 | siz[0] = sz; | |
1020 | ||
1021 | if (siz[1] <= sz) | |
1022 | siz[1] = sz; | |
1023 | ||
1024 | if (sz != 0) | |
1025 | { | |
1026 | if (wi::lts_p (off, ovloff[0])) | |
1027 | ovloff[0] = off.to_shwi (); | |
1028 | if (wi::lts_p (ovloff[1], off)) | |
1029 | ovloff[1] = off.to_shwi (); | |
1030 | } | |
1031 | } | |
1032 | } | |
1033 | else | |
1034 | { | |
1035 | sub1 = !depends_p; | |
1036 | ||
1037 | /* Iterate over the extreme locations (on the horizontal axis | |
1038 | formed by their offsets) and sizes of two regions and find | |
1039 | their smallest and largest overlap and the corresponding | |
1040 | offsets. */ | |
1041 | ||
1042 | for (unsigned io = 0; io != 2; ++io) | |
1043 | for (unsigned is = 0; is != 2; ++is) | |
1044 | { | |
1045 | const offset_int a[2] = { | |
1046 | acs.dstoff[io], acs.dstoff[io] + acs.dstsiz[is] | |
1047 | }; | |
1048 | ||
1049 | for (unsigned jo = 0; jo != 2; ++jo) | |
1050 | for (unsigned js = 0; js != 2; ++js) | |
1051 | { | |
1052 | if (depends_p) | |
1053 | { | |
1054 | /* For st{p,r}ncpy the size of the source sequence | |
1055 | depends on the offset into it. */ | |
1056 | if (js) | |
1057 | break; | |
1058 | js = !jo; | |
1059 | } | |
1060 | ||
1061 | const offset_int b[2] = { | |
1062 | acs.srcoff[jo], acs.srcoff[jo] + acs.srcsiz[js] | |
1063 | }; | |
1064 | ||
1065 | offset_int off; | |
1066 | offset_int sz = overlap_size (a, b, &off); | |
1067 | if (sz < siz[0]) | |
1068 | siz[0] = sz; | |
1069 | ||
1070 | if (siz[1] <= sz) | |
1071 | siz[1] = sz; | |
1072 | ||
1073 | if (sz != 0) | |
1074 | { | |
1075 | if (wi::lts_p (off, ovloff[0])) | |
1076 | ovloff[0] = off.to_shwi (); | |
1077 | if (wi::lts_p (ovloff[1], off)) | |
1078 | ovloff[1] = off.to_shwi (); | |
1079 | } | |
1080 | } | |
1081 | } | |
1082 | } | |
1083 | ||
1084 | ovlsiz[0] = siz[0].to_shwi (); | |
1085 | ovlsiz[1] = siz[1].to_shwi (); | |
1086 | ||
1087 | if (ovlsiz[0] == 0 && ovlsiz[1] > 1) | |
1088 | ovloff[0] = ovloff[1] + ovlsiz[1] - 1 - sub1; | |
1089 | ||
1090 | return true; | |
1091 | } | |
1092 | ||
1093 | /* Return true if the strcat-like access overlaps. */ | |
1094 | ||
1095 | bool | |
1096 | builtin_access::strcat_overlap () | |
1097 | { | |
1098 | builtin_access &acs = *this; | |
1099 | const builtin_memref *dstref = acs.dstref; | |
1100 | const builtin_memref *srcref = acs.srcref; | |
1101 | ||
1102 | gcc_assert (dstref->base == srcref->base); | |
1103 | ||
a411ae9b | 1104 | const offset_int maxobjsize = acs.dstref->maxobjsize; |
cc8bea0a MS |
1105 | |
1106 | gcc_assert (dstref->base && dstref->base == srcref->base); | |
1107 | ||
1108 | /* Adjust for strcat-like accesses. */ | |
1109 | ||
1110 | /* As a special case for strcat, set the DSTREF offsets to the length | |
1111 | of the source string since the function starts writing at the first | |
1112 | nul, and set the size to 1 for the length of the nul. */ | |
1113 | acs.dstoff[0] += acs.dstsiz[0]; | |
1114 | acs.dstoff[1] += acs.dstsiz[1]; | |
1115 | ||
1116 | bool strfunc_unknown_args = acs.dstsiz[0] == 0 && acs.dstsiz[1] != 0; | |
1117 | ||
1118 | /* The lower bound is zero when the size is unknown because then | |
1119 | overlap is not certain. */ | |
1120 | acs.dstsiz[0] = strfunc_unknown_args ? 0 : 1; | |
1121 | acs.dstsiz[1] = 1; | |
1122 | ||
1123 | offset_int maxsize = dstref->basesize < 0 ? maxobjsize : dstref->basesize; | |
1124 | gcc_assert (maxsize <= maxobjsize); | |
1125 | ||
1126 | /* For references to the same base object, determine if there's a pair | |
1127 | of valid offsets into the two references such that access between | |
1128 | them doesn't overlap. Adjust both upper bounds to be valid for | |
1129 | the smaller size (i.e., at most MAXSIZE - SIZE). */ | |
1130 | ||
1131 | if (maxsize < acs.dstoff[1] + acs.dstsiz[0]) | |
1132 | acs.dstoff[1] = maxsize - acs.dstsiz[0]; | |
1133 | ||
1134 | if (maxsize < acs.srcoff[1] + acs.srcsiz[0]) | |
1135 | acs.srcoff[1] = maxsize - acs.srcsiz[0]; | |
1136 | ||
1137 | /* Check to see if there's enough space for both accesses without | |
1138 | overlap. Determine the optimistic (maximum) amount of available | |
1139 | space. */ | |
1140 | offset_int space; | |
1141 | if (acs.dstoff[0] <= acs.srcoff[0]) | |
1142 | { | |
1143 | if (acs.dstoff[1] < acs.srcoff[1]) | |
1144 | space = acs.srcoff[1] + acs.srcsiz[0] - acs.dstoff[0]; | |
1145 | else | |
1146 | space = acs.dstoff[1] + acs.dstsiz[0] - acs.srcoff[0]; | |
1147 | } | |
1148 | else | |
1149 | space = acs.dstoff[1] + acs.dstsiz[0] - acs.srcoff[0]; | |
1150 | ||
1151 | /* Overlap is certain if the distance between the farthest offsets | |
1152 | of the opposite accesses is less than the sum of the lower bounds | |
1153 | of the sizes of the two accesses. */ | |
1154 | bool overlap_certain = space < acs.dstsiz[0] + acs.srcsiz[0]; | |
1155 | ||
1156 | /* For a constant-offset, constant size access, consider the largest | |
1157 | distance between the offset bounds and the lower bound of the access | |
1158 | size. If the overlap isn't certain return success. */ | |
1159 | if (!overlap_certain | |
1160 | && acs.dstoff[0] == acs.dstoff[1] | |
1161 | && acs.srcoff[0] == acs.srcoff[1] | |
1162 | && acs.dstsiz[0] == acs.dstsiz[1] | |
1163 | && acs.srcsiz[0] == acs.srcsiz[1]) | |
1164 | return false; | |
1165 | ||
1166 | /* Overlap is not certain but may be possible. */ | |
1167 | ||
1168 | offset_int access_min = acs.dstsiz[0] + acs.srcsiz[0]; | |
1169 | ||
1170 | /* Determine the conservative (minimum) amount of space. */ | |
1171 | space = wi::abs (acs.dstoff[0] - acs.srcoff[0]); | |
1172 | offset_int d = wi::abs (acs.dstoff[0] - acs.srcoff[1]); | |
1173 | if (d < space) | |
1174 | space = d; | |
1175 | d = wi::abs (acs.dstoff[1] - acs.srcoff[0]); | |
1176 | if (d < space) | |
1177 | space = d; | |
1178 | ||
1179 | /* For a strict test (used for strcpy and similar with unknown or | |
1180 | variable bounds or sizes), consider the smallest distance between | |
1181 | the offset bounds and either the upper bound of the access size | |
1182 | if known, or the lower bound otherwise. */ | |
1183 | if (access_min <= space && (access_min != 0 || !strfunc_unknown_args)) | |
1184 | return false; | |
1185 | ||
1186 | /* When strcat overlap is certain it is always a single byte: | |
816fad6e | 1187 | the terminating NUL, regardless of offsets and sizes. When |
cc8bea0a MS |
1188 | overlap is only possible its range is [0, 1]. */ |
1189 | acs.ovlsiz[0] = dstref->sizrange[0] == dstref->sizrange[1] ? 1 : 0; | |
1190 | acs.ovlsiz[1] = 1; | |
cc8bea0a | 1191 | |
816fad6e MS |
1192 | offset_int endoff = dstref->offrange[0] + dstref->sizrange[0]; |
1193 | if (endoff <= srcref->offrange[0]) | |
1194 | acs.ovloff[0] = wi::smin (maxobjsize, srcref->offrange[0]).to_shwi (); | |
1195 | else | |
1196 | acs.ovloff[0] = wi::smin (maxobjsize, endoff).to_shwi (); | |
1197 | ||
1198 | acs.sizrange[0] = wi::smax (wi::abs (endoff - srcref->offrange[0]) + 1, | |
1199 | srcref->sizrange[0]).to_shwi (); | |
1200 | if (dstref->offrange[0] == dstref->offrange[1]) | |
1201 | { | |
1202 | if (srcref->offrange[0] == srcref->offrange[1]) | |
1203 | acs.ovloff[1] = acs.ovloff[0]; | |
1204 | else | |
1205 | acs.ovloff[1] | |
1206 | = wi::smin (maxobjsize, | |
1207 | srcref->offrange[1] + srcref->sizrange[1]).to_shwi (); | |
1208 | } | |
1209 | else | |
1210 | acs.ovloff[1] | |
1211 | = wi::smin (maxobjsize, | |
1212 | dstref->offrange[1] + dstref->sizrange[1]).to_shwi (); | |
1213 | ||
1214 | if (acs.sizrange[0] == 0) | |
1215 | acs.sizrange[0] = 1; | |
cc8bea0a MS |
1216 | acs.sizrange[1] = wi::smax (acs.dstsiz[1], srcref->sizrange[1]).to_shwi (); |
1217 | return true; | |
1218 | } | |
1219 | ||
1220 | /* Return true if the strcpy-like access overlaps. */ | |
1221 | ||
1222 | bool | |
1223 | builtin_access::strcpy_overlap () | |
1224 | { | |
1225 | return generic_overlap (); | |
1226 | } | |
1227 | ||
1228 | ||
1229 | /* Return true if DSTREF and SRCREF describe accesses that either overlap | |
1230 | one another or that, in order not to overlap, would imply that the size | |
1231 | of the referenced object(s) exceeds the maximum size of an object. Set | |
1232 | Otherwise, if DSTREF and SRCREF do not definitely overlap (even though | |
1233 | they may overlap in a way that's not apparent from the available data), | |
1234 | return false. */ | |
1235 | ||
1236 | bool | |
1237 | builtin_access::overlap () | |
1238 | { | |
1239 | builtin_access &acs = *this; | |
1240 | ||
a411ae9b | 1241 | const offset_int maxobjsize = dstref->maxobjsize; |
cc8bea0a MS |
1242 | |
1243 | acs.sizrange[0] = wi::smax (dstref->sizrange[0], | |
1244 | srcref->sizrange[0]).to_shwi (); | |
1245 | acs.sizrange[1] = wi::smax (dstref->sizrange[1], | |
1246 | srcref->sizrange[1]).to_shwi (); | |
1247 | ||
1248 | /* Check to see if the two references refer to regions that are | |
1249 | too large not to overlap in the address space (whose maximum | |
1250 | size is PTRDIFF_MAX). */ | |
1251 | offset_int size = dstref->sizrange[0] + srcref->sizrange[0]; | |
1252 | if (maxobjsize < size) | |
1253 | { | |
1254 | acs.ovloff[0] = (maxobjsize - dstref->sizrange[0]).to_shwi (); | |
1255 | acs.ovlsiz[0] = (size - maxobjsize).to_shwi (); | |
1256 | return true; | |
1257 | } | |
1258 | ||
1259 | /* If both base objects aren't known return the maximum possible | |
1260 | offset that would make them not overlap. */ | |
1261 | if (!dstref->base || !srcref->base) | |
1262 | return false; | |
1263 | ||
c7c9468a JL |
1264 | /* Set the access offsets. */ |
1265 | acs.dstoff[0] = dstref->offrange[0]; | |
1266 | acs.dstoff[1] = dstref->offrange[1]; | |
1267 | ||
1268 | /* If the base object is an array adjust the bounds of the offset | |
1269 | to be non-negative and within the bounds of the array if possible. */ | |
cc8bea0a MS |
1270 | if (dstref->base |
1271 | && TREE_CODE (TREE_TYPE (dstref->base)) == ARRAY_TYPE) | |
c7c9468a JL |
1272 | { |
1273 | if (acs.dstoff[0] < 0 && acs.dstoff[1] >= 0) | |
1274 | acs.dstoff[0] = 0; | |
cc8bea0a | 1275 | |
c7c9468a JL |
1276 | if (acs.dstoff[1] < acs.dstoff[0]) |
1277 | { | |
1278 | if (tree size = TYPE_SIZE_UNIT (TREE_TYPE (dstref->base))) | |
1279 | acs.dstoff[1] = wi::umin (acs.dstoff[1], wi::to_offset (size)); | |
1280 | else | |
1281 | acs.dstoff[1] = wi::umin (acs.dstoff[1], maxobjsize); | |
1282 | } | |
1283 | } | |
1284 | ||
1285 | acs.srcoff[0] = srcref->offrange[0]; | |
1286 | acs.srcoff[1] = srcref->offrange[1]; | |
cc8bea0a MS |
1287 | |
1288 | if (srcref->base | |
1289 | && TREE_CODE (TREE_TYPE (srcref->base)) == ARRAY_TYPE) | |
c7c9468a JL |
1290 | { |
1291 | if (acs.srcoff[0] < 0 && acs.srcoff[1] >= 0) | |
1292 | acs.srcoff[0] = 0; | |
cc8bea0a | 1293 | |
c7c9468a JL |
1294 | if (tree size = TYPE_SIZE_UNIT (TREE_TYPE (srcref->base))) |
1295 | acs.srcoff[1] = wi::umin (acs.srcoff[1], wi::to_offset (size)); | |
1296 | else if (acs.srcoff[1] < acs.srcoff[0]) | |
1297 | acs.srcoff[1] = wi::umin (acs.srcoff[1], maxobjsize); | |
1298 | } | |
cc8bea0a | 1299 | |
c7c9468a JL |
1300 | /* When the upper bound of the offset is less than the lower bound |
1301 | the former is the result of a negative offset being represented | |
1302 | as a large positive value or vice versa. The resulting range is | |
1303 | a union of two subranges: [MIN, UB] and [LB, MAX]. Since such | |
1304 | a union is not representable using the current data structure | |
1305 | replace it with the full range of offsets. */ | |
cc8bea0a | 1306 | if (acs.dstoff[1] < acs.dstoff[0]) |
c7c9468a JL |
1307 | { |
1308 | acs.dstoff[0] = -maxobjsize - 1; | |
1309 | acs.dstoff[1] = maxobjsize; | |
1310 | } | |
cc8bea0a MS |
1311 | |
1312 | /* Validate the offset and size of each reference on its own first. | |
1313 | This is independent of whether or not the base objects are the | |
1314 | same. Normally, this would have already been detected and | |
1315 | diagnosed by -Warray-bounds, unless it has been disabled. */ | |
1316 | offset_int maxoff = acs.dstoff[0] + dstref->sizrange[0]; | |
1317 | if (maxobjsize < maxoff) | |
1318 | { | |
1319 | acs.ovlsiz[0] = (maxoff - maxobjsize).to_shwi (); | |
1320 | acs.ovloff[0] = acs.dstoff[0].to_shwi () - acs.ovlsiz[0]; | |
1321 | return true; | |
1322 | } | |
1323 | ||
1324 | /* Repeat the same as above but for the source offsets. */ | |
1325 | if (acs.srcoff[1] < acs.srcoff[0]) | |
c7c9468a JL |
1326 | { |
1327 | acs.srcoff[0] = -maxobjsize - 1; | |
1328 | acs.srcoff[1] = maxobjsize; | |
1329 | } | |
cc8bea0a MS |
1330 | |
1331 | maxoff = acs.srcoff[0] + srcref->sizrange[0]; | |
1332 | if (maxobjsize < maxoff) | |
1333 | { | |
1334 | acs.ovlsiz[0] = (maxoff - maxobjsize).to_shwi (); | |
1335 | acs.ovlsiz[1] = (acs.srcoff[0] + srcref->sizrange[1] | |
1336 | - maxobjsize).to_shwi (); | |
1337 | acs.ovloff[0] = acs.srcoff[0].to_shwi () - acs.ovlsiz[0]; | |
1338 | return true; | |
1339 | } | |
1340 | ||
1341 | if (dstref->base != srcref->base) | |
1342 | return false; | |
1343 | ||
1344 | acs.dstsiz[0] = dstref->sizrange[0]; | |
1345 | acs.dstsiz[1] = dstref->sizrange[1]; | |
1346 | ||
1347 | acs.srcsiz[0] = srcref->sizrange[0]; | |
1348 | acs.srcsiz[1] = srcref->sizrange[1]; | |
1349 | ||
1350 | /* Call the appropriate function to determine the overlap. */ | |
1351 | if ((this->*detect_overlap) ()) | |
1352 | { | |
816fad6e MS |
1353 | if (!sizrange[1]) |
1354 | { | |
1355 | /* Unless the access size range has already been set, do so here. */ | |
1356 | sizrange[0] = wi::smax (acs.dstsiz[0], srcref->sizrange[0]).to_shwi (); | |
1357 | sizrange[1] = wi::smax (acs.dstsiz[1], srcref->sizrange[1]).to_shwi (); | |
1358 | } | |
cc8bea0a MS |
1359 | return true; |
1360 | } | |
1361 | ||
1362 | return false; | |
1363 | } | |
1364 | ||
1365 | /* Attempt to detect and diagnose an overlapping copy in a call expression | |
1366 | EXPR involving an an access ACS to a built-in memory or string function. | |
1367 | Return true when one has been detected, false otherwise. */ | |
1368 | ||
1369 | static bool | |
8a45b051 | 1370 | maybe_diag_overlap (location_t loc, gimple *call, builtin_access &acs) |
cc8bea0a MS |
1371 | { |
1372 | if (!acs.overlap ()) | |
1373 | return false; | |
1374 | ||
213694e5 MS |
1375 | if (gimple_no_warning_p (call)) |
1376 | return true; | |
1377 | ||
cc8bea0a MS |
1378 | /* For convenience. */ |
1379 | const builtin_memref &dstref = *acs.dstref; | |
1380 | const builtin_memref &srcref = *acs.srcref; | |
1381 | ||
1382 | /* Determine the range of offsets and sizes of the overlap if it | |
1383 | exists and issue diagnostics. */ | |
1384 | HOST_WIDE_INT *ovloff = acs.ovloff; | |
1385 | HOST_WIDE_INT *ovlsiz = acs.ovlsiz; | |
1386 | HOST_WIDE_INT *sizrange = acs.sizrange; | |
1387 | ||
1388 | tree func = gimple_call_fndecl (call); | |
1389 | ||
1390 | /* To avoid a combinatorial explosion of diagnostics format the offsets | |
1391 | or their ranges as strings and use them in the warning calls below. */ | |
1392 | char offstr[3][64]; | |
1393 | ||
1394 | if (dstref.offrange[0] == dstref.offrange[1] | |
1395 | || dstref.offrange[1] > HOST_WIDE_INT_MAX) | |
a6fd2cd7 MS |
1396 | sprintf (offstr[0], HOST_WIDE_INT_PRINT_DEC, |
1397 | dstref.offrange[0].to_shwi ()); | |
cc8bea0a | 1398 | else |
a6fd2cd7 MS |
1399 | sprintf (offstr[0], |
1400 | "[" HOST_WIDE_INT_PRINT_DEC ", " HOST_WIDE_INT_PRINT_DEC "]", | |
1401 | dstref.offrange[0].to_shwi (), | |
1402 | dstref.offrange[1].to_shwi ()); | |
cc8bea0a MS |
1403 | |
1404 | if (srcref.offrange[0] == srcref.offrange[1] | |
1405 | || srcref.offrange[1] > HOST_WIDE_INT_MAX) | |
a6fd2cd7 MS |
1406 | sprintf (offstr[1], |
1407 | HOST_WIDE_INT_PRINT_DEC, | |
1408 | srcref.offrange[0].to_shwi ()); | |
cc8bea0a | 1409 | else |
a6fd2cd7 MS |
1410 | sprintf (offstr[1], |
1411 | "[" HOST_WIDE_INT_PRINT_DEC ", " HOST_WIDE_INT_PRINT_DEC "]", | |
1412 | srcref.offrange[0].to_shwi (), | |
1413 | srcref.offrange[1].to_shwi ()); | |
cc8bea0a MS |
1414 | |
1415 | if (ovloff[0] == ovloff[1] || !ovloff[1]) | |
a6fd2cd7 | 1416 | sprintf (offstr[2], HOST_WIDE_INT_PRINT_DEC, ovloff[0]); |
cc8bea0a | 1417 | else |
a6fd2cd7 MS |
1418 | sprintf (offstr[2], |
1419 | "[" HOST_WIDE_INT_PRINT_DEC ", " HOST_WIDE_INT_PRINT_DEC "]", | |
1420 | ovloff[0], ovloff[1]); | |
cc8bea0a | 1421 | |
a411ae9b | 1422 | const offset_int maxobjsize = dstref.maxobjsize; |
cc8bea0a MS |
1423 | bool must_overlap = ovlsiz[0] > 0; |
1424 | ||
1425 | if (ovlsiz[1] == 0) | |
1426 | ovlsiz[1] = ovlsiz[0]; | |
1427 | ||
1428 | if (must_overlap) | |
1429 | { | |
1430 | /* Issue definitive "overlaps" diagnostic in this block. */ | |
1431 | ||
1432 | if (sizrange[0] == sizrange[1]) | |
1433 | { | |
1434 | if (ovlsiz[0] == ovlsiz[1]) | |
1435 | warning_at (loc, OPT_Wrestrict, | |
1436 | sizrange[0] == 1 | |
1437 | ? (ovlsiz[0] == 1 | |
1438 | ? G_("%G%qD accessing %wu byte at offsets %s " | |
1439 | "and %s overlaps %wu byte at offset %s") | |
1440 | : G_("%G%qD accessing %wu byte at offsets %s " | |
1441 | "and %s overlaps %wu bytes at offset " | |
1442 | "%s")) | |
1443 | : (ovlsiz[0] == 1 | |
1444 | ? G_("%G%qD accessing %wu bytes at offsets %s " | |
1445 | "and %s overlaps %wu byte at offset %s") | |
1446 | : G_("%G%qD accessing %wu bytes at offsets %s " | |
1447 | "and %s overlaps %wu bytes at offset " | |
1448 | "%s")), | |
1449 | call, func, sizrange[0], | |
1450 | offstr[0], offstr[1], ovlsiz[0], offstr[2]); | |
1451 | else if (ovlsiz[1] >= 0 && ovlsiz[1] < maxobjsize.to_shwi ()) | |
15d3974b JJ |
1452 | warning_n (loc, OPT_Wrestrict, sizrange[0], |
1453 | "%G%qD accessing %wu byte at offsets %s " | |
1454 | "and %s overlaps between %wu and %wu bytes " | |
1455 | "at offset %s", | |
1456 | "%G%qD accessing %wu bytes at offsets %s " | |
1457 | "and %s overlaps between %wu and %wu bytes " | |
1458 | "at offset %s", | |
1459 | call, func, sizrange[0], offstr[0], offstr[1], | |
1460 | ovlsiz[0], ovlsiz[1], offstr[2]); | |
cc8bea0a | 1461 | else |
15d3974b JJ |
1462 | warning_n (loc, OPT_Wrestrict, sizrange[0], |
1463 | "%G%qD accessing %wu byte at offsets %s and " | |
1464 | "%s overlaps %wu or more bytes at offset %s", | |
1465 | "%G%qD accessing %wu bytes at offsets %s and " | |
1466 | "%s overlaps %wu or more bytes at offset %s", | |
1467 | call, func, sizrange[0], | |
1468 | offstr[0], offstr[1], ovlsiz[0], offstr[2]); | |
cc8bea0a MS |
1469 | return true; |
1470 | } | |
1471 | ||
1472 | if (sizrange[1] >= 0 && sizrange[1] < maxobjsize.to_shwi ()) | |
1473 | { | |
1474 | if (ovlsiz[0] == ovlsiz[1]) | |
15d3974b JJ |
1475 | warning_n (loc, OPT_Wrestrict, ovlsiz[0], |
1476 | "%G%qD accessing between %wu and %wu bytes " | |
1477 | "at offsets %s and %s overlaps %wu byte at " | |
1478 | "offset %s", | |
1479 | "%G%qD accessing between %wu and %wu bytes " | |
1480 | "at offsets %s and %s overlaps %wu bytes " | |
1481 | "at offset %s", | |
1482 | call, func, sizrange[0], sizrange[1], | |
1483 | offstr[0], offstr[1], ovlsiz[0], offstr[2]); | |
cc8bea0a MS |
1484 | else if (ovlsiz[1] >= 0 && ovlsiz[1] < maxobjsize.to_shwi ()) |
1485 | warning_at (loc, OPT_Wrestrict, | |
1486 | "%G%qD accessing between %wu and %wu bytes at " | |
1487 | "offsets %s and %s overlaps between %wu and %wu " | |
1488 | "bytes at offset %s", | |
1489 | call, func, sizrange[0], sizrange[1], | |
1490 | offstr[0], offstr[1], ovlsiz[0], ovlsiz[1], | |
1491 | offstr[2]); | |
1492 | else | |
1493 | warning_at (loc, OPT_Wrestrict, | |
1494 | "%G%qD accessing between %wu and %wu bytes at " | |
1495 | "offsets %s and %s overlaps %wu or more bytes " | |
1496 | "at offset %s", | |
1497 | call, func, sizrange[0], sizrange[1], | |
1498 | offstr[0], offstr[1], ovlsiz[0], offstr[2]); | |
1499 | return true; | |
1500 | } | |
1501 | ||
1502 | if (ovlsiz[0] != ovlsiz[1]) | |
1503 | ovlsiz[1] = maxobjsize.to_shwi (); | |
1504 | ||
1505 | if (ovlsiz[0] == ovlsiz[1]) | |
15d3974b JJ |
1506 | warning_n (loc, OPT_Wrestrict, ovlsiz[0], |
1507 | "%G%qD accessing %wu or more bytes at offsets " | |
1508 | "%s and %s overlaps %wu byte at offset %s", | |
1509 | "%G%qD accessing %wu or more bytes at offsets " | |
1510 | "%s and %s overlaps %wu bytes at offset %s", | |
1511 | call, func, sizrange[0], offstr[0], offstr[1], | |
1512 | ovlsiz[0], offstr[2]); | |
cc8bea0a MS |
1513 | else if (ovlsiz[1] >= 0 && ovlsiz[1] < maxobjsize.to_shwi ()) |
1514 | warning_at (loc, OPT_Wrestrict, | |
1515 | "%G%qD accessing %wu or more bytes at offsets %s " | |
1516 | "and %s overlaps between %wu and %wu bytes " | |
1517 | "at offset %s", | |
1518 | call, func, sizrange[0], offstr[0], offstr[1], | |
1519 | ovlsiz[0], ovlsiz[1], offstr[2]); | |
1520 | else | |
1521 | warning_at (loc, OPT_Wrestrict, | |
1522 | "%G%qD accessing %wu or more bytes at offsets %s " | |
1523 | "and %s overlaps %wu or more bytes at offset %s", | |
1524 | call, func, sizrange[0], offstr[0], offstr[1], | |
1525 | ovlsiz[0], offstr[2]); | |
1526 | return true; | |
1527 | } | |
1528 | ||
cc8bea0a MS |
1529 | /* Use more concise wording when one of the offsets is unbounded |
1530 | to avoid confusing the user with large and mostly meaningless | |
1531 | numbers. */ | |
816fad6e MS |
1532 | bool open_range; |
1533 | if (DECL_P (dstref.base) && TREE_CODE (TREE_TYPE (dstref.base)) == ARRAY_TYPE) | |
1534 | open_range = ((dstref.offrange[0] == 0 | |
1535 | && dstref.offrange[1] == maxobjsize) | |
1536 | || (srcref.offrange[0] == 0 | |
1537 | && srcref.offrange[1] == maxobjsize)); | |
1538 | else | |
1539 | open_range = ((dstref.offrange[0] == -maxobjsize - 1 | |
1540 | && dstref.offrange[1] == maxobjsize) | |
1541 | || (srcref.offrange[0] == -maxobjsize - 1 | |
1542 | && srcref.offrange[1] == maxobjsize)); | |
cc8bea0a MS |
1543 | |
1544 | if (sizrange[0] == sizrange[1] || sizrange[1] == 1) | |
1545 | { | |
1546 | if (ovlsiz[1] == 1) | |
1547 | { | |
1548 | if (open_range) | |
15d3974b JJ |
1549 | warning_n (loc, OPT_Wrestrict, sizrange[1], |
1550 | "%G%qD accessing %wu byte may overlap " | |
1551 | "%wu byte", | |
1552 | "%G%qD accessing %wu bytes may overlap " | |
1553 | "%wu byte", | |
1554 | call, func, sizrange[1], ovlsiz[1]); | |
cc8bea0a | 1555 | else |
15d3974b JJ |
1556 | warning_n (loc, OPT_Wrestrict, sizrange[1], |
1557 | "%G%qD accessing %wu byte at offsets %s " | |
1558 | "and %s may overlap %wu byte at offset %s", | |
1559 | "%G%qD accessing %wu bytes at offsets %s " | |
1560 | "and %s may overlap %wu byte at offset %s", | |
1561 | call, func, sizrange[1], offstr[0], offstr[1], | |
1562 | ovlsiz[1], offstr[2]); | |
cc8bea0a MS |
1563 | return true; |
1564 | } | |
1565 | ||
1566 | if (open_range) | |
15d3974b JJ |
1567 | warning_n (loc, OPT_Wrestrict, sizrange[1], |
1568 | "%G%qD accessing %wu byte may overlap " | |
1569 | "up to %wu bytes", | |
1570 | "%G%qD accessing %wu bytes may overlap " | |
1571 | "up to %wu bytes", | |
1572 | call, func, sizrange[1], ovlsiz[1]); | |
cc8bea0a | 1573 | else |
15d3974b JJ |
1574 | warning_n (loc, OPT_Wrestrict, sizrange[1], |
1575 | "%G%qD accessing %wu byte at offsets %s and " | |
1576 | "%s may overlap up to %wu bytes at offset %s", | |
1577 | "%G%qD accessing %wu bytes at offsets %s and " | |
1578 | "%s may overlap up to %wu bytes at offset %s", | |
1579 | call, func, sizrange[1], offstr[0], offstr[1], | |
1580 | ovlsiz[1], offstr[2]); | |
cc8bea0a MS |
1581 | return true; |
1582 | } | |
1583 | ||
1584 | if (sizrange[1] >= 0 && sizrange[1] < maxobjsize.to_shwi ()) | |
1585 | { | |
1586 | if (open_range) | |
15d3974b JJ |
1587 | warning_n (loc, OPT_Wrestrict, ovlsiz[1], |
1588 | "%G%qD accessing between %wu and %wu bytes " | |
1589 | "may overlap %wu byte", | |
1590 | "%G%qD accessing between %wu and %wu bytes " | |
1591 | "may overlap up to %wu bytes", | |
1592 | call, func, sizrange[0], sizrange[1], ovlsiz[1]); | |
cc8bea0a | 1593 | else |
15d3974b JJ |
1594 | warning_n (loc, OPT_Wrestrict, ovlsiz[1], |
1595 | "%G%qD accessing between %wu and %wu bytes " | |
1596 | "at offsets %s and %s may overlap %wu byte " | |
1597 | "at offset %s", | |
1598 | "%G%qD accessing between %wu and %wu bytes " | |
1599 | "at offsets %s and %s may overlap up to %wu " | |
1600 | "bytes at offset %s", | |
1601 | call, func, sizrange[0], sizrange[1], | |
1602 | offstr[0], offstr[1], ovlsiz[1], offstr[2]); | |
cc8bea0a MS |
1603 | return true; |
1604 | } | |
1605 | ||
15d3974b JJ |
1606 | warning_n (loc, OPT_Wrestrict, ovlsiz[1], |
1607 | "%G%qD accessing %wu or more bytes at offsets %s " | |
1608 | "and %s may overlap %wu byte at offset %s", | |
1609 | "%G%qD accessing %wu or more bytes at offsets %s " | |
1610 | "and %s may overlap up to %wu bytes at offset %s", | |
1611 | call, func, sizrange[0], offstr[0], offstr[1], | |
1612 | ovlsiz[1], offstr[2]); | |
cc8bea0a MS |
1613 | |
1614 | return true; | |
1615 | } | |
1616 | ||
287ef129 MS |
1617 | /* Validate REF size and offsets in an expression passed as an argument |
1618 | to a CALL to a built-in function FUNC to make sure they are within | |
1619 | the bounds of the referenced object if its size is known, or | |
1620 | PTRDIFF_MAX otherwise. DO_WARN is true when a diagnostic should | |
1621 | be issued, false otherwise. | |
1622 | Both initial values of the offsets and their final value computed | |
1623 | by the function by incrementing the initial value by the size are | |
cc8bea0a | 1624 | validated. Return true if the offsets are not valid and a diagnostic |
287ef129 | 1625 | has been issued, or would have been issued if DO_WARN had been true. */ |
cc8bea0a MS |
1626 | |
1627 | static bool | |
287ef129 | 1628 | maybe_diag_access_bounds (location_t loc, gimple *call, tree func, int strict, |
213694e5 | 1629 | const builtin_memref &ref, bool do_warn) |
cc8bea0a | 1630 | { |
a411ae9b | 1631 | const offset_int maxobjsize = ref.maxobjsize; |
287ef129 MS |
1632 | |
1633 | /* Check for excessive size first and regardless of warning options | |
1634 | since the result is used to make codegen decisions. */ | |
1635 | if (ref.sizrange[0] > maxobjsize) | |
1636 | { | |
1637 | /* Return true without issuing a warning. */ | |
1638 | if (!do_warn) | |
1639 | return true; | |
1640 | ||
1641 | if (ref.ref && TREE_NO_WARNING (ref.ref)) | |
1642 | return false; | |
1643 | ||
1644 | if (warn_stringop_overflow) | |
1645 | { | |
1646 | if (EXPR_HAS_LOCATION (ref.ptr)) | |
1647 | loc = EXPR_LOCATION (ref.ptr); | |
1648 | ||
1649 | loc = expansion_point_location_if_in_system_header (loc); | |
1650 | ||
1651 | if (ref.sizrange[0] == ref.sizrange[1]) | |
1652 | return warning_at (loc, OPT_Wstringop_overflow_, | |
1653 | "%G%qD specified bound %wu " | |
1654 | "exceeds maximum object size %wu", | |
1655 | call, func, ref.sizrange[0].to_uhwi (), | |
1656 | maxobjsize.to_uhwi ()); | |
1657 | ||
1658 | return warning_at (loc, OPT_Wstringop_overflow_, | |
1659 | "%G%qD specified bound between %wu and %wu " | |
1660 | "exceeds maximum object size %wu", | |
1661 | call, func, ref.sizrange[0].to_uhwi (), | |
1662 | ref.sizrange[1].to_uhwi (), | |
1663 | maxobjsize.to_uhwi ()); | |
1664 | } | |
1665 | } | |
1666 | ||
213694e5 MS |
1667 | /* Check for out-bounds pointers regardless of warning options since |
1668 | the result is used to make codegen decisions. */ | |
1669 | offset_int ooboff[] = { ref.offrange[0], ref.offrange[1] }; | |
1670 | tree oobref = ref.offset_out_of_bounds (strict, ooboff); | |
1671 | if (!oobref) | |
cc8bea0a MS |
1672 | return false; |
1673 | ||
213694e5 MS |
1674 | /* Return true without issuing a warning. */ |
1675 | if (!do_warn) | |
1676 | return true; | |
1677 | ||
1678 | if (!warn_array_bounds) | |
21150aba JJ |
1679 | return false; |
1680 | ||
213694e5 | 1681 | if (ref.ref && TREE_NO_WARNING (ref.ref)) |
cc8bea0a MS |
1682 | return false; |
1683 | ||
213694e5 MS |
1684 | if (EXPR_HAS_LOCATION (ref.ptr)) |
1685 | loc = EXPR_LOCATION (ref.ptr); | |
cc8bea0a MS |
1686 | |
1687 | loc = expansion_point_location_if_in_system_header (loc); | |
1688 | ||
cc8bea0a MS |
1689 | char rangestr[2][64]; |
1690 | if (ooboff[0] == ooboff[1] | |
1691 | || (ooboff[0] != ref.offrange[0] | |
1692 | && ooboff[0].to_shwi () >= ooboff[1].to_shwi ())) | |
1693 | sprintf (rangestr[0], "%lli", (long long) ooboff[0].to_shwi ()); | |
1694 | else | |
1695 | sprintf (rangestr[0], "[%lli, %lli]", | |
1696 | (long long) ooboff[0].to_shwi (), | |
1697 | (long long) ooboff[1].to_shwi ()); | |
1698 | ||
e3329a78 MS |
1699 | bool warned = false; |
1700 | ||
cc8bea0a MS |
1701 | if (oobref == error_mark_node) |
1702 | { | |
1703 | if (ref.sizrange[0] == ref.sizrange[1]) | |
287ef129 MS |
1704 | sprintf (rangestr[1], "%llu", |
1705 | (unsigned long long) ref.sizrange[0].to_shwi ()); | |
cc8bea0a MS |
1706 | else |
1707 | sprintf (rangestr[1], "[%lli, %lli]", | |
287ef129 MS |
1708 | (unsigned long long) ref.sizrange[0].to_uhwi (), |
1709 | (unsigned long long) ref.sizrange[1].to_uhwi ()); | |
cc8bea0a | 1710 | |
e3329a78 MS |
1711 | tree type; |
1712 | ||
cc8bea0a MS |
1713 | if (DECL_P (ref.base) |
1714 | && TREE_CODE (type = TREE_TYPE (ref.base)) == ARRAY_TYPE) | |
1715 | { | |
097f82ec | 1716 | auto_diagnostic_group d; |
cc8bea0a MS |
1717 | if (warning_at (loc, OPT_Warray_bounds, |
1718 | "%G%qD pointer overflow between offset %s " | |
1719 | "and size %s accessing array %qD with type %qT", | |
1720 | call, func, rangestr[0], rangestr[1], ref.base, type)) | |
e3329a78 MS |
1721 | { |
1722 | inform (DECL_SOURCE_LOCATION (ref.base), | |
1723 | "array %qD declared here", ref.base); | |
1724 | warned = true; | |
1725 | } | |
cc8bea0a | 1726 | else |
e3329a78 MS |
1727 | warned = warning_at (loc, OPT_Warray_bounds, |
1728 | "%G%qD pointer overflow between offset %s " | |
1729 | "and size %s", | |
1730 | call, func, rangestr[0], rangestr[1]); | |
cc8bea0a MS |
1731 | } |
1732 | else | |
e3329a78 MS |
1733 | warned = warning_at (loc, OPT_Warray_bounds, |
1734 | "%G%qD pointer overflow between offset %s " | |
1735 | "and size %s", | |
1736 | call, func, rangestr[0], rangestr[1]); | |
cc8bea0a MS |
1737 | } |
1738 | else if (oobref == ref.base) | |
1739 | { | |
cc8bea0a MS |
1740 | /* True when the offset formed by an access to the reference |
1741 | is out of bounds, rather than the initial offset wich is | |
1742 | in bounds. This implies access past the end. */ | |
1743 | bool form = ooboff[0] != ref.offrange[0]; | |
1744 | ||
1745 | if (DECL_P (ref.base)) | |
1746 | { | |
097f82ec | 1747 | auto_diagnostic_group d; |
cc8bea0a MS |
1748 | if ((ref.basesize < maxobjsize |
1749 | && warning_at (loc, OPT_Warray_bounds, | |
1750 | form | |
1751 | ? G_("%G%qD forming offset %s is out of " | |
1752 | "the bounds [0, %wu] of object %qD with " | |
1753 | "type %qT") | |
1754 | : G_("%G%qD offset %s is out of the bounds " | |
1755 | "[0, %wu] of object %qD with type %qT"), | |
1756 | call, func, rangestr[0], ref.basesize.to_uhwi (), | |
1757 | ref.base, TREE_TYPE (ref.base))) | |
1758 | || warning_at (loc, OPT_Warray_bounds, | |
1759 | form | |
1760 | ? G_("%G%qD forming offset %s is out of " | |
1761 | "the bounds of object %qD with type %qT") | |
1762 | : G_("%G%qD offset %s is out of the bounds " | |
1763 | "of object %qD with type %qT"), | |
1764 | call, func, rangestr[0], | |
1765 | ref.base, TREE_TYPE (ref.base))) | |
e3329a78 MS |
1766 | { |
1767 | inform (DECL_SOURCE_LOCATION (ref.base), | |
1768 | "%qD declared here", ref.base); | |
1769 | warned = true; | |
1770 | } | |
cc8bea0a MS |
1771 | } |
1772 | else if (ref.basesize < maxobjsize) | |
e3329a78 MS |
1773 | warned = warning_at (loc, OPT_Warray_bounds, |
1774 | form | |
1775 | ? G_("%G%qD forming offset %s is out " | |
1776 | "of the bounds [0, %wu]") | |
1777 | : G_("%G%qD offset %s is out " | |
1778 | "of the bounds [0, %wu]"), | |
1779 | call, func, rangestr[0], ref.basesize.to_uhwi ()); | |
cc8bea0a | 1780 | else |
e3329a78 MS |
1781 | warned = warning_at (loc, OPT_Warray_bounds, |
1782 | form | |
1783 | ? G_("%G%qD forming offset %s is out of bounds") | |
1784 | : G_("%G%qD offset %s is out of bounds"), | |
1785 | call, func, rangestr[0]); | |
cc8bea0a MS |
1786 | } |
1787 | else if (TREE_CODE (ref.ref) == MEM_REF) | |
1788 | { | |
1789 | tree type = TREE_TYPE (TREE_OPERAND (ref.ref, 0)); | |
1790 | if (POINTER_TYPE_P (type)) | |
1791 | type = TREE_TYPE (type); | |
1792 | type = TYPE_MAIN_VARIANT (type); | |
1793 | ||
e3329a78 MS |
1794 | warned = warning_at (loc, OPT_Warray_bounds, |
1795 | "%G%qD offset %s from the object at %qE is out " | |
1796 | "of the bounds of %qT", | |
1797 | call, func, rangestr[0], ref.base, type); | |
cc8bea0a MS |
1798 | } |
1799 | else | |
1800 | { | |
e3329a78 MS |
1801 | tree type = TYPE_MAIN_VARIANT (TREE_TYPE (ref.ref)); |
1802 | ||
1803 | warned = warning_at (loc, OPT_Warray_bounds, | |
1804 | "%G%qD offset %s from the object at %qE is out " | |
1805 | "of the bounds of referenced subobject %qD with " | |
1806 | "type %qT at offset %wu", | |
1807 | call, func, rangestr[0], ref.base, | |
1808 | TREE_OPERAND (ref.ref, 1), type, | |
1809 | ref.refoff.to_uhwi ()); | |
cc8bea0a MS |
1810 | } |
1811 | ||
e3329a78 | 1812 | return warned; |
cc8bea0a MS |
1813 | } |
1814 | ||
1815 | /* Check a CALL statement for restrict-violations and issue warnings | |
1816 | if/when appropriate. */ | |
1817 | ||
1818 | void | |
8a45b051 | 1819 | wrestrict_dom_walker::check_call (gimple *call) |
cc8bea0a MS |
1820 | { |
1821 | /* Avoid checking the call if it has already been diagnosed for | |
1822 | some reason. */ | |
1823 | if (gimple_no_warning_p (call)) | |
1824 | return; | |
1825 | ||
1826 | tree func = gimple_call_fndecl (call); | |
3d78e008 | 1827 | if (!func || !fndecl_built_in_p (func, BUILT_IN_NORMAL)) |
cc8bea0a MS |
1828 | return; |
1829 | ||
cc8bea0a MS |
1830 | /* Argument number to extract from the call (depends on the built-in |
1831 | and its kind). */ | |
1832 | unsigned dst_idx = -1; | |
1833 | unsigned src_idx = -1; | |
1834 | unsigned bnd_idx = -1; | |
1835 | ||
1836 | /* Is this CALL to a string function (as opposed to one to a raw | |
1837 | memory function). */ | |
1838 | bool strfun = true; | |
1839 | ||
1840 | switch (DECL_FUNCTION_CODE (func)) | |
1841 | { | |
1842 | case BUILT_IN_MEMCPY: | |
1843 | case BUILT_IN_MEMCPY_CHK: | |
cc8bea0a MS |
1844 | case BUILT_IN_MEMPCPY: |
1845 | case BUILT_IN_MEMPCPY_CHK: | |
cc8bea0a MS |
1846 | case BUILT_IN_MEMMOVE: |
1847 | case BUILT_IN_MEMMOVE_CHK: | |
cc8bea0a MS |
1848 | strfun = false; |
1849 | /* Fall through. */ | |
1850 | ||
1851 | case BUILT_IN_STPNCPY: | |
1852 | case BUILT_IN_STPNCPY_CHK: | |
1853 | case BUILT_IN_STRNCAT: | |
1854 | case BUILT_IN_STRNCAT_CHK: | |
1855 | case BUILT_IN_STRNCPY: | |
1856 | case BUILT_IN_STRNCPY_CHK: | |
1857 | dst_idx = 0; | |
31db0fe0 ML |
1858 | src_idx = 1; |
1859 | bnd_idx = 2; | |
cc8bea0a MS |
1860 | break; |
1861 | ||
a411ae9b MS |
1862 | case BUILT_IN_MEMSET: |
1863 | case BUILT_IN_MEMSET_CHK: | |
1864 | dst_idx = 0; | |
1865 | bnd_idx = 2; | |
1866 | break; | |
1867 | ||
cc8bea0a MS |
1868 | case BUILT_IN_STPCPY: |
1869 | case BUILT_IN_STPCPY_CHK: | |
cc8bea0a MS |
1870 | case BUILT_IN_STRCPY: |
1871 | case BUILT_IN_STRCPY_CHK: | |
cc8bea0a MS |
1872 | case BUILT_IN_STRCAT: |
1873 | case BUILT_IN_STRCAT_CHK: | |
cc8bea0a | 1874 | dst_idx = 0; |
31db0fe0 | 1875 | src_idx = 1; |
cc8bea0a MS |
1876 | break; |
1877 | ||
1878 | default: | |
1879 | /* Handle other string functions here whose access may need | |
1880 | to be validated for in-bounds offsets and non-overlapping | |
31db0fe0 | 1881 | copies. */ |
cc8bea0a MS |
1882 | return; |
1883 | } | |
1884 | ||
1885 | unsigned nargs = gimple_call_num_args (call); | |
1886 | ||
1887 | tree dst = dst_idx < nargs ? gimple_call_arg (call, dst_idx) : NULL_TREE; | |
1888 | tree src = src_idx < nargs ? gimple_call_arg (call, src_idx) : NULL_TREE; | |
1889 | tree dstwr = bnd_idx < nargs ? gimple_call_arg (call, bnd_idx) : NULL_TREE; | |
1890 | ||
1891 | /* For string functions with an unspecified or unknown bound, | |
1892 | assume the size of the access is one. */ | |
1893 | if (!dstwr && strfun) | |
1894 | dstwr = size_one_node; | |
1895 | ||
2438cb6a MS |
1896 | /* DST and SRC can be null for a call with an insufficient number |
1897 | of arguments to a built-in function declared without a protype. */ | |
a411ae9b | 1898 | if (!dst || (src_idx < nargs && !src)) |
cf3fc0e8 MS |
1899 | return; |
1900 | ||
1901 | /* DST, SRC, or DSTWR can also have the wrong type in a call to | |
1902 | a function declared without a prototype. Avoid checking such | |
1903 | invalid calls. */ | |
1904 | if (TREE_CODE (TREE_TYPE (dst)) != POINTER_TYPE | |
a411ae9b | 1905 | || (src && TREE_CODE (TREE_TYPE (src)) != POINTER_TYPE) |
cf3fc0e8 MS |
1906 | || (dstwr && !INTEGRAL_TYPE_P (TREE_TYPE (dstwr)))) |
1907 | return; | |
1908 | ||
213694e5 | 1909 | if (!check_bounds_or_overlap (call, dst, src, dstwr, NULL_TREE)) |
cc8bea0a MS |
1910 | return; |
1911 | ||
1912 | /* Avoid diagnosing the call again. */ | |
1913 | gimple_set_no_warning (call, true); | |
1914 | } | |
1915 | ||
1916 | } /* anonymous namespace */ | |
1917 | ||
1918 | /* Attempt to detect and diagnose invalid offset bounds and (except for | |
1919 | memmove) overlapping copy in a call expression EXPR from SRC to DST | |
1920 | and DSTSIZE and SRCSIZE bytes, respectively. Both DSTSIZE and | |
213694e5 MS |
1921 | SRCSIZE may be NULL. DO_WARN is false to detect either problem |
1922 | without issue a warning. Return the OPT_Wxxx constant corresponding | |
1923 | to the warning if one has been detected and zero otherwise. */ | |
cc8bea0a | 1924 | |
213694e5 | 1925 | int |
8a45b051 | 1926 | check_bounds_or_overlap (gimple *call, tree dst, tree src, tree dstsize, |
213694e5 MS |
1927 | tree srcsize, bool bounds_only /* = false */, |
1928 | bool do_warn /* = true */) | |
cc8bea0a | 1929 | { |
e3329a78 | 1930 | location_t loc = gimple_nonartificial_location (call); |
cc8bea0a MS |
1931 | loc = expansion_point_location_if_in_system_header (loc); |
1932 | ||
1933 | tree func = gimple_call_fndecl (call); | |
1934 | ||
1935 | builtin_memref dstref (dst, dstsize); | |
1936 | builtin_memref srcref (src, srcsize); | |
1937 | ||
1938 | builtin_access acs (call, dstref, srcref); | |
1939 | ||
1940 | /* Set STRICT to the value of the -Warray-bounds=N argument for | |
1941 | string functions or when N > 1. */ | |
1942 | int strict = (acs.strict () || warn_array_bounds > 1 ? warn_array_bounds : 0); | |
1943 | ||
1944 | /* Validate offsets first to make sure they are within the bounds | |
1945 | of the destination object if its size is known, or PTRDIFF_MAX | |
1946 | otherwise. */ | |
287ef129 MS |
1947 | if (maybe_diag_access_bounds (loc, call, func, strict, dstref, do_warn) |
1948 | || maybe_diag_access_bounds (loc, call, func, strict, srcref, do_warn)) | |
cc8bea0a | 1949 | { |
213694e5 MS |
1950 | if (do_warn) |
1951 | gimple_set_no_warning (call, true); | |
1952 | return OPT_Warray_bounds; | |
cc8bea0a MS |
1953 | } |
1954 | ||
a411ae9b | 1955 | if (!warn_restrict || bounds_only || !src) |
213694e5 | 1956 | return 0; |
cc8bea0a | 1957 | |
a411ae9b MS |
1958 | if (!bounds_only) |
1959 | { | |
1960 | switch (DECL_FUNCTION_CODE (func)) | |
1961 | { | |
1962 | case BUILT_IN_MEMMOVE: | |
1963 | case BUILT_IN_MEMMOVE_CHK: | |
1964 | case BUILT_IN_MEMSET: | |
1965 | case BUILT_IN_MEMSET_CHK: | |
1966 | return 0; | |
1967 | default: | |
1968 | break; | |
1969 | } | |
1970 | } | |
1971 | ||
cc8bea0a MS |
1972 | if (operand_equal_p (dst, src, 0)) |
1973 | { | |
8cd95cec MS |
1974 | /* Issue -Wrestrict unless the pointers are null (those do |
1975 | not point to objects and so do not indicate an overlap; | |
1976 | such calls could be the result of sanitization and jump | |
1977 | threading). */ | |
1978 | if (!integer_zerop (dst) && !gimple_no_warning_p (call)) | |
1979 | { | |
1980 | warning_at (loc, OPT_Wrestrict, | |
1981 | "%G%qD source argument is the same as destination", | |
1982 | call, func); | |
1983 | gimple_set_no_warning (call, true); | |
213694e5 | 1984 | return OPT_Wrestrict; |
8cd95cec MS |
1985 | } |
1986 | ||
213694e5 | 1987 | return 0; |
cc8bea0a MS |
1988 | } |
1989 | ||
1990 | /* Return false when overlap has been detected. */ | |
1991 | if (maybe_diag_overlap (loc, call, acs)) | |
1992 | { | |
1993 | gimple_set_no_warning (call, true); | |
213694e5 | 1994 | return OPT_Wrestrict; |
cc8bea0a MS |
1995 | } |
1996 | ||
213694e5 | 1997 | return 0; |
cc8bea0a MS |
1998 | } |
1999 | ||
2000 | gimple_opt_pass * | |
2001 | make_pass_warn_restrict (gcc::context *ctxt) | |
2002 | { | |
2003 | return new pass_wrestrict (ctxt); | |
2004 | } |