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cc8bea0a MS |
1 | /* Pass to detect and issue warnings for violations of the restrict |
2 | qualifier. | |
99dee823 | 3 | Copyright (C) 2017-2021 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" | |
cc8bea0a MS |
28 | #include "tree-pass.h" |
29 | #include "builtins.h" | |
30 | #include "ssa.h" | |
31 | #include "gimple-pretty-print.h" | |
32 | #include "gimple-ssa-warn-restrict.h" | |
33 | #include "diagnostic-core.h" | |
34 | #include "fold-const.h" | |
35 | #include "gimple-iterator.h" | |
36 | #include "tree-dfa.h" | |
37 | #include "tree-ssa.h" | |
cc8bea0a MS |
38 | #include "tree-cfg.h" |
39 | #include "tree-object-size.h" | |
40 | #include "calls.h" | |
41 | #include "cfgloop.h" | |
42 | #include "intl.h" | |
e864d395 | 43 | #include "gimple-range.h" |
cc8bea0a MS |
44 | |
45 | namespace { | |
46 | ||
47 | const pass_data pass_data_wrestrict = { | |
48 | GIMPLE_PASS, | |
49 | "wrestrict", | |
50 | OPTGROUP_NONE, | |
51 | TV_NONE, | |
52 | PROP_cfg, /* Properties_required. */ | |
53 | 0, /* properties_provided. */ | |
54 | 0, /* properties_destroyed. */ | |
55 | 0, /* properties_start */ | |
56 | 0, /* properties_finish */ | |
57 | }; | |
58 | ||
59 | /* Pass to detect violations of strict aliasing requirements in calls | |
60 | to built-in string and raw memory functions. */ | |
61 | class pass_wrestrict : public gimple_opt_pass | |
62 | { | |
63 | public: | |
64 | pass_wrestrict (gcc::context *ctxt) | |
65 | : gimple_opt_pass (pass_data_wrestrict, ctxt) | |
66 | { } | |
67 | ||
68 | opt_pass *clone () { return new pass_wrestrict (m_ctxt); } | |
69 | ||
70 | virtual bool gate (function *); | |
71 | virtual unsigned int execute (function *); | |
72 | }; | |
73 | ||
74 | bool | |
75 | pass_wrestrict::gate (function *fun ATTRIBUTE_UNUSED) | |
76 | { | |
287ef129 | 77 | return warn_array_bounds || warn_restrict || warn_stringop_overflow; |
cc8bea0a MS |
78 | } |
79 | ||
e864d395 | 80 | static void check_call (range_query *, gimple *); |
cc8bea0a | 81 | |
e864d395 AH |
82 | static void |
83 | wrestrict_walk (range_query *query, basic_block bb) | |
cc8bea0a MS |
84 | { |
85 | /* Iterate over statements, looking for function calls. */ | |
86 | for (gimple_stmt_iterator si = gsi_start_bb (bb); !gsi_end_p (si); | |
87 | gsi_next (&si)) | |
88 | { | |
89 | gimple *stmt = gsi_stmt (si); | |
90 | if (!is_gimple_call (stmt)) | |
91 | continue; | |
92 | ||
e864d395 | 93 | check_call (query, stmt); |
cc8bea0a | 94 | } |
cc8bea0a MS |
95 | } |
96 | ||
cc8bea0a MS |
97 | unsigned |
98 | pass_wrestrict::execute (function *fun) | |
99 | { | |
e864d395 AH |
100 | gimple_ranger ranger; |
101 | basic_block bb; | |
102 | FOR_EACH_BB_FN (bb, fun) | |
103 | wrestrict_walk (&ranger, bb); | |
cc8bea0a MS |
104 | |
105 | return 0; | |
106 | } | |
107 | ||
108 | /* Description of a memory reference by a built-in function. This | |
109 | is similar to ao_ref but made especially suitable for -Wrestrict | |
110 | and not for optimization. */ | |
6c1dae73 | 111 | class builtin_memref |
cc8bea0a | 112 | { |
6c1dae73 | 113 | public: |
cc8bea0a MS |
114 | /* The original pointer argument to the built-in function. */ |
115 | tree ptr; | |
116 | /* The referenced subobject or NULL if not available, and the base | |
117 | object of the memory reference or NULL. */ | |
118 | tree ref; | |
119 | tree base; | |
120 | ||
121 | /* The size of the BASE object, PTRDIFF_MAX if indeterminate, | |
122 | and negative until (possibly lazily) initialized. */ | |
123 | offset_int basesize; | |
6889a3ac MS |
124 | /* Same for the subobject. */ |
125 | offset_int refsize; | |
cc8bea0a MS |
126 | |
127 | /* The non-negative offset of the referenced subobject. Used to avoid | |
128 | warnings for (apparently) possibly but not definitively overlapping | |
129 | accesses to member arrays. Negative when unknown/invalid. */ | |
130 | offset_int refoff; | |
131 | ||
132 | /* The offset range relative to the base. */ | |
133 | offset_int offrange[2]; | |
134 | /* The size range of the access to this reference. */ | |
135 | offset_int sizrange[2]; | |
136 | ||
a411ae9b MS |
137 | /* Cached result of get_max_objsize(). */ |
138 | const offset_int maxobjsize; | |
139 | ||
cc8bea0a MS |
140 | /* True for "bounded" string functions like strncat, and strncpy |
141 | and their variants that specify either an exact or upper bound | |
142 | on the size of the accesses they perform. For strncat both | |
143 | the source and destination references are bounded. For strncpy | |
144 | only the destination reference is. */ | |
145 | bool strbounded_p; | |
146 | ||
e864d395 | 147 | builtin_memref (range_query *, gimple *, tree, tree); |
cc8bea0a | 148 | |
6889a3ac | 149 | tree offset_out_of_bounds (int, offset_int[3]) const; |
5e27f0d5 MS |
150 | |
151 | private: | |
e864d395 AH |
152 | /* Call statement to the built-in. */ |
153 | gimple *stmt; | |
154 | ||
155 | range_query *query; | |
5e27f0d5 MS |
156 | |
157 | /* Ctor helper to set or extend OFFRANGE based on argument. */ | |
158 | void extend_offset_range (tree); | |
159 | ||
160 | /* Ctor helper to determine BASE and OFFRANGE from argument. */ | |
161 | void set_base_and_offset (tree); | |
cc8bea0a MS |
162 | }; |
163 | ||
164 | /* Description of a memory access by a raw memory or string built-in | |
165 | function involving a pair of builtin_memref's. */ | |
166 | class builtin_access | |
167 | { | |
168 | public: | |
169 | /* Destination and source memory reference. */ | |
170 | builtin_memref* const dstref; | |
171 | builtin_memref* const srcref; | |
172 | /* The size range of the access. It's the greater of the accesses | |
173 | to the two references. */ | |
174 | HOST_WIDE_INT sizrange[2]; | |
175 | ||
176 | /* The minimum and maximum offset of an overlap of the access | |
177 | (if it does, in fact, overlap), and the size of the overlap. */ | |
178 | HOST_WIDE_INT ovloff[2]; | |
179 | HOST_WIDE_INT ovlsiz[2]; | |
180 | ||
181 | /* True to consider valid only accesses to the smallest subobject | |
182 | and false for raw memory functions. */ | |
183 | bool strict () const | |
184 | { | |
6889a3ac MS |
185 | return (detect_overlap != &builtin_access::generic_overlap |
186 | && detect_overlap != &builtin_access::no_overlap); | |
cc8bea0a MS |
187 | } |
188 | ||
e864d395 | 189 | builtin_access (range_query *, gimple *, builtin_memref &, builtin_memref &); |
cc8bea0a MS |
190 | |
191 | /* Entry point to determine overlap. */ | |
192 | bool overlap (); | |
193 | ||
6889a3ac MS |
194 | offset_int write_off (tree) const; |
195 | ||
196 | void dump (FILE *) const; | |
197 | ||
cc8bea0a MS |
198 | private: |
199 | /* Implementation functions used to determine overlap. */ | |
200 | bool generic_overlap (); | |
201 | bool strcat_overlap (); | |
202 | bool strcpy_overlap (); | |
203 | ||
204 | bool no_overlap () | |
205 | { | |
206 | return false; | |
207 | } | |
208 | ||
209 | offset_int overlap_size (const offset_int [2], const offset_int[2], | |
210 | offset_int [2]); | |
211 | ||
212 | private: | |
213 | /* Temporaries used to compute the final result. */ | |
214 | offset_int dstoff[2]; | |
215 | offset_int srcoff[2]; | |
216 | offset_int dstsiz[2]; | |
217 | offset_int srcsiz[2]; | |
218 | ||
219 | /* Pointer to a member function to call to determine overlap. */ | |
220 | bool (builtin_access::*detect_overlap) (); | |
221 | }; | |
222 | ||
223 | /* Initialize a memory reference representation from a pointer EXPR and | |
224 | a size SIZE in bytes. If SIZE is NULL_TREE then the size is assumed | |
e864d395 | 225 | to be unknown. STMT is the statement in which expr appears in. */ |
cc8bea0a | 226 | |
e864d395 AH |
227 | builtin_memref::builtin_memref (range_query *query, gimple *stmt, tree expr, |
228 | tree size) | |
cc8bea0a MS |
229 | : ptr (expr), |
230 | ref (), | |
231 | base (), | |
232 | basesize (-1), | |
6889a3ac | 233 | refsize (-1), |
cc8bea0a MS |
234 | refoff (HOST_WIDE_INT_MIN), |
235 | offrange (), | |
236 | sizrange (), | |
a411ae9b | 237 | maxobjsize (tree_to_shwi (max_object_size ())), |
e864d395 AH |
238 | strbounded_p (), |
239 | stmt (stmt), | |
240 | query (query) | |
cc8bea0a MS |
241 | { |
242 | /* Unfortunately, wide_int default ctor is a no-op so array members | |
243 | of the type must be set individually. */ | |
244 | offrange[0] = offrange[1] = 0; | |
245 | sizrange[0] = sizrange[1] = 0; | |
246 | ||
a411ae9b MS |
247 | if (!expr) |
248 | return; | |
cc8bea0a | 249 | |
5e27f0d5 MS |
250 | /* Find the BASE object or pointer referenced by EXPR and set |
251 | the offset range OFFRANGE in the process. */ | |
252 | set_base_and_offset (expr); | |
253 | ||
254 | if (size) | |
255 | { | |
256 | tree range[2]; | |
257 | /* Determine the size range, allowing for the result to be [0, 0] | |
258 | for SIZE in the anti-range ~[0, N] where N >= PTRDIFF_MAX. */ | |
e864d395 | 259 | get_size_range (query, size, stmt, range, SR_ALLOW_ZERO); |
5e27f0d5 MS |
260 | sizrange[0] = wi::to_offset (range[0]); |
261 | sizrange[1] = wi::to_offset (range[1]); | |
262 | /* get_size_range returns SIZE_MAX for the maximum size. | |
263 | Constrain it to the real maximum of PTRDIFF_MAX. */ | |
287ef129 | 264 | if (sizrange[0] <= maxobjsize && sizrange[1] > maxobjsize) |
5e27f0d5 MS |
265 | sizrange[1] = maxobjsize; |
266 | } | |
267 | else | |
268 | sizrange[1] = maxobjsize; | |
269 | ||
7ad491c6 MS |
270 | if (!DECL_P (base)) |
271 | return; | |
272 | ||
273 | /* If the offset could be in the range of the referenced object | |
274 | constrain its bounds so neither exceeds those of the object. */ | |
275 | if (offrange[0] < 0 && offrange[1] > 0) | |
276 | offrange[0] = 0; | |
277 | ||
278 | offset_int maxoff = maxobjsize; | |
5e27f0d5 | 279 | tree basetype = TREE_TYPE (base); |
1486eb79 MS |
280 | if (TREE_CODE (basetype) == ARRAY_TYPE) |
281 | { | |
282 | if (ref && array_at_struct_end_p (ref)) | |
283 | ; /* Use the maximum possible offset for last member arrays. */ | |
284 | else if (tree basesize = TYPE_SIZE_UNIT (basetype)) | |
285 | if (TREE_CODE (basesize) == INTEGER_CST) | |
286 | /* Size could be non-constant for a variable-length type such | |
287 | as a struct with a VLA member (a GCC extension). */ | |
288 | maxoff = wi::to_offset (basesize); | |
289 | } | |
7ad491c6 MS |
290 | |
291 | if (offrange[0] >= 0) | |
5e27f0d5 | 292 | { |
7ad491c6 MS |
293 | if (offrange[1] < 0) |
294 | offrange[1] = offrange[0] <= maxoff ? maxoff : maxobjsize; | |
295 | else if (offrange[0] <= maxoff && offrange[1] > maxoff) | |
296 | offrange[1] = maxoff; | |
5e27f0d5 MS |
297 | } |
298 | } | |
299 | ||
6889a3ac MS |
300 | /* Based on the initial length of the destination STARTLEN, returns |
301 | the offset of the first write access from the beginning of | |
302 | the destination. Nonzero only for strcat-type of calls. */ | |
303 | ||
304 | offset_int builtin_access::write_off (tree startlen) const | |
305 | { | |
306 | if (detect_overlap != &builtin_access::strcat_overlap | |
307 | || !startlen || TREE_CODE (startlen) != INTEGER_CST) | |
308 | return 0; | |
309 | ||
310 | return wi::to_offset (startlen); | |
311 | } | |
312 | ||
a411ae9b MS |
313 | /* Ctor helper to set or extend OFFRANGE based on the OFFSET argument. |
314 | Pointer offsets are represented as unsigned sizetype but must be | |
315 | treated as signed. */ | |
5e27f0d5 MS |
316 | |
317 | void | |
318 | builtin_memref::extend_offset_range (tree offset) | |
319 | { | |
5e27f0d5 MS |
320 | if (TREE_CODE (offset) == INTEGER_CST) |
321 | { | |
322 | offset_int off = int_cst_value (offset); | |
323 | if (off != 0) | |
324 | { | |
325 | offrange[0] += off; | |
326 | offrange[1] += off; | |
327 | } | |
328 | return; | |
329 | } | |
330 | ||
331 | if (TREE_CODE (offset) == SSA_NAME) | |
332 | { | |
a411ae9b MS |
333 | /* A pointer offset is represented as sizetype but treated |
334 | as signed. */ | |
5e27f0d5 | 335 | wide_int min, max; |
e864d395 AH |
336 | value_range_kind rng; |
337 | value_range vr; | |
338 | if (query && query->range_of_expr (vr, offset, stmt)) | |
339 | { | |
340 | rng = vr.kind (); | |
341 | if (!vr.undefined_p ()) | |
342 | { | |
343 | min = wi::to_wide (vr.min ()); | |
344 | max = wi::to_wide (vr.max ()); | |
345 | } | |
346 | } | |
347 | else | |
348 | { | |
349 | /* There is a global version here because | |
350 | check_bounds_or_overlap may be called from gimple | |
351 | fold during gimple lowering. */ | |
352 | rng = get_range_info (offset, &min, &max); | |
353 | } | |
a411ae9b MS |
354 | if (rng == VR_ANTI_RANGE && wi::lts_p (max, min)) |
355 | { | |
356 | /* Convert an anti-range whose upper bound is less than | |
357 | its lower bound to a signed range. */ | |
358 | offrange[0] += offset_int::from (max + 1, SIGNED); | |
359 | offrange[1] += offset_int::from (min - 1, SIGNED); | |
360 | return; | |
361 | } | |
362 | ||
363 | if (rng == VR_RANGE | |
364 | && (DECL_P (base) || wi::lts_p (min, max))) | |
5e27f0d5 | 365 | { |
a411ae9b MS |
366 | /* Preserve the bounds of the range for an offset into |
367 | a known object (it may be adjusted later relative to | |
368 | a constant offset from its beginning). Otherwise use | |
369 | the bounds only when they are ascending when treated | |
370 | as signed. */ | |
5e27f0d5 MS |
371 | offrange[0] += offset_int::from (min, SIGNED); |
372 | offrange[1] += offset_int::from (max, SIGNED); | |
a411ae9b | 373 | return; |
5e27f0d5 | 374 | } |
a411ae9b MS |
375 | |
376 | /* Handle an anti-range the same as no range at all. */ | |
377 | gimple *stmt = SSA_NAME_DEF_STMT (offset); | |
378 | tree type; | |
379 | if (is_gimple_assign (stmt) | |
380 | && (type = TREE_TYPE (gimple_assign_rhs1 (stmt))) | |
381 | && INTEGRAL_TYPE_P (type)) | |
5e27f0d5 | 382 | { |
a411ae9b MS |
383 | tree_code code = gimple_assign_rhs_code (stmt); |
384 | if (code == NOP_EXPR) | |
5e27f0d5 MS |
385 | { |
386 | /* Use the bounds of the type of the NOP_EXPR operand | |
387 | even if it's signed. The result doesn't trigger | |
388 | warnings but makes their output more readable. */ | |
389 | offrange[0] += wi::to_offset (TYPE_MIN_VALUE (type)); | |
390 | offrange[1] += wi::to_offset (TYPE_MAX_VALUE (type)); | |
a411ae9b | 391 | return; |
5e27f0d5 | 392 | } |
5e27f0d5 | 393 | } |
5e27f0d5 MS |
394 | } |
395 | ||
a411ae9b MS |
396 | const offset_int maxoff = tree_to_shwi (max_object_size ()) >> 1; |
397 | const offset_int minoff = -maxoff - 1; | |
398 | ||
399 | offrange[0] += minoff; | |
400 | offrange[1] += maxoff; | |
5e27f0d5 MS |
401 | } |
402 | ||
403 | /* Determines the base object or pointer of the reference EXPR | |
404 | and the offset range from the beginning of the base. */ | |
405 | ||
406 | void | |
407 | builtin_memref::set_base_and_offset (tree expr) | |
408 | { | |
a411ae9b | 409 | tree offset = NULL_TREE; |
5e27f0d5 | 410 | |
cc8bea0a MS |
411 | if (TREE_CODE (expr) == SSA_NAME) |
412 | { | |
413 | /* Try to tease the offset out of the pointer. */ | |
414 | gimple *stmt = SSA_NAME_DEF_STMT (expr); | |
5e27f0d5 MS |
415 | if (!base |
416 | && gimple_assign_single_p (stmt) | |
cc8bea0a MS |
417 | && gimple_assign_rhs_code (stmt) == ADDR_EXPR) |
418 | expr = gimple_assign_rhs1 (stmt); | |
419 | else if (is_gimple_assign (stmt)) | |
420 | { | |
421 | tree_code code = gimple_assign_rhs_code (stmt); | |
422 | if (code == NOP_EXPR) | |
423 | { | |
424 | tree rhs = gimple_assign_rhs1 (stmt); | |
425 | if (POINTER_TYPE_P (TREE_TYPE (rhs))) | |
426 | expr = gimple_assign_rhs1 (stmt); | |
5e27f0d5 MS |
427 | else |
428 | { | |
429 | base = expr; | |
430 | return; | |
431 | } | |
cc8bea0a MS |
432 | } |
433 | else if (code == POINTER_PLUS_EXPR) | |
434 | { | |
435 | expr = gimple_assign_rhs1 (stmt); | |
a411ae9b | 436 | offset = gimple_assign_rhs2 (stmt); |
cc8bea0a | 437 | } |
5e27f0d5 MS |
438 | else |
439 | { | |
440 | base = expr; | |
441 | return; | |
442 | } | |
443 | } | |
444 | else | |
445 | { | |
a411ae9b MS |
446 | /* FIXME: Handle PHI nodes in case like: |
447 | _12 = &MEM[(void *)&a + 2B] + _10; | |
448 | ||
449 | <bb> [local count: 1073741824]: | |
450 | # prephitmp_13 = PHI <_12, &MEM[(void *)&a + 2B]> | |
451 | memcpy (prephitmp_13, p_7(D), 6); */ | |
5e27f0d5 MS |
452 | base = expr; |
453 | return; | |
cc8bea0a MS |
454 | } |
455 | } | |
456 | ||
457 | if (TREE_CODE (expr) == ADDR_EXPR) | |
5e27f0d5 | 458 | expr = TREE_OPERAND (expr, 0); |
cc8bea0a | 459 | |
8286793a MS |
460 | /* Stash the reference for offset validation. */ |
461 | ref = expr; | |
462 | ||
5e27f0d5 MS |
463 | poly_int64 bitsize, bitpos; |
464 | tree var_off; | |
465 | machine_mode mode; | |
466 | int sign, reverse, vol; | |
cc8bea0a | 467 | |
5e27f0d5 MS |
468 | /* Determine the base object or pointer of the reference and |
469 | the constant bit offset from the beginning of the base. | |
470 | If the offset has a non-constant component, it will be in | |
471 | VAR_OFF. MODE, SIGN, REVERSE, and VOL are write only and | |
472 | unused here. */ | |
473 | base = get_inner_reference (expr, &bitsize, &bitpos, &var_off, | |
474 | &mode, &sign, &reverse, &vol); | |
cc8bea0a | 475 | |
8286793a MS |
476 | /* get_inner_reference is not expected to return null. */ |
477 | gcc_assert (base != NULL); | |
478 | ||
a411ae9b MS |
479 | if (offset) |
480 | extend_offset_range (offset); | |
481 | ||
5e27f0d5 | 482 | poly_int64 bytepos = exact_div (bitpos, BITS_PER_UNIT); |
cc8bea0a | 483 | |
ce811fc4 | 484 | /* Convert the poly_int64 offset to offset_int. The offset |
8286793a MS |
485 | should be constant but be prepared for it not to be just in |
486 | case. */ | |
487 | offset_int cstoff; | |
488 | if (bytepos.is_constant (&cstoff)) | |
5e27f0d5 | 489 | { |
8286793a MS |
490 | offrange[0] += cstoff; |
491 | offrange[1] += cstoff; | |
cc8bea0a | 492 | |
8286793a MS |
493 | /* Besides the reference saved above, also stash the offset |
494 | for validation. */ | |
495 | if (TREE_CODE (expr) == COMPONENT_REF) | |
496 | refoff = cstoff; | |
497 | } | |
498 | else | |
499 | offrange[1] += maxobjsize; | |
cc8bea0a | 500 | |
5e27f0d5 | 501 | if (var_off) |
cc8bea0a | 502 | { |
5e27f0d5 | 503 | if (TREE_CODE (var_off) == INTEGER_CST) |
aca52e6f | 504 | { |
8286793a | 505 | cstoff = wi::to_offset (var_off); |
5e27f0d5 MS |
506 | offrange[0] += cstoff; |
507 | offrange[1] += cstoff; | |
aca52e6f RS |
508 | } |
509 | else | |
5e27f0d5 | 510 | offrange[1] += maxobjsize; |
cc8bea0a MS |
511 | } |
512 | ||
5e27f0d5 | 513 | if (TREE_CODE (base) == MEM_REF) |
816fad6e | 514 | { |
6889a3ac | 515 | tree memrefoff = fold_convert (ptrdiff_type_node, TREE_OPERAND (base, 1)); |
5e27f0d5 MS |
516 | extend_offset_range (memrefoff); |
517 | base = TREE_OPERAND (base, 0); | |
6889a3ac MS |
518 | |
519 | if (refoff != HOST_WIDE_INT_MIN | |
520 | && TREE_CODE (expr) == COMPONENT_REF) | |
521 | { | |
522 | /* Bump up the offset of the referenced subobject to reflect | |
523 | the offset to the enclosing object. For example, so that | |
524 | in | |
525 | struct S { char a, b[3]; } s[2]; | |
526 | strcpy (s[1].b, "1234"); | |
527 | REFOFF is set to s[1].b - (char*)s. */ | |
81011859 MS |
528 | offset_int off = tree_to_shwi (memrefoff); |
529 | refoff += off; | |
6889a3ac MS |
530 | } |
531 | ||
532 | if (!integer_zerop (memrefoff)) | |
533 | /* A non-zero offset into an array of struct with flexible array | |
534 | members implies that the array is empty because there is no | |
535 | way to initialize such a member when it belongs to an array. | |
536 | This must be some sort of a bug. */ | |
537 | refsize = 0; | |
816fad6e MS |
538 | } |
539 | ||
6889a3ac MS |
540 | if (TREE_CODE (ref) == COMPONENT_REF) |
541 | if (tree size = component_ref_size (ref)) | |
542 | if (TREE_CODE (size) == INTEGER_CST) | |
543 | refsize = wi::to_offset (size); | |
544 | ||
5e27f0d5 MS |
545 | if (TREE_CODE (base) == SSA_NAME) |
546 | set_base_and_offset (base); | |
cc8bea0a MS |
547 | } |
548 | ||
549 | /* Return error_mark_node if the signed offset exceeds the bounds | |
6889a3ac MS |
550 | of the address space (PTRDIFF_MAX). Otherwise, return either BASE |
551 | or REF when the offset exceeds the bounds of the BASE or REF object, | |
552 | and set OOBOFF to the past-the-end offset formed by the reference, | |
553 | including its size. OOBOFF is initially setto the range of offsets, | |
554 | and OOBOFF[2] to the offset of the first write access (nonzero for | |
555 | the strcat family). When STRICT is nonzero use REF size, when | |
556 | available, otherwise use BASE size. When STRICT is greater than 1, | |
557 | use the size of the last array member as the bound, otherwise treat | |
558 | such a member as a flexible array member. Return NULL when the offset | |
559 | is in bounds. */ | |
cc8bea0a MS |
560 | |
561 | tree | |
6889a3ac | 562 | builtin_memref::offset_out_of_bounds (int strict, offset_int ooboff[3]) const |
cc8bea0a | 563 | { |
a411ae9b MS |
564 | if (!ptr) |
565 | return NULL_TREE; | |
cc8bea0a | 566 | |
6889a3ac MS |
567 | /* The offset of the first write access or zero. */ |
568 | offset_int wroff = ooboff[2]; | |
569 | ||
cc8bea0a | 570 | /* A temporary, possibly adjusted, copy of the offset range. */ |
6889a3ac | 571 | offset_int offrng[2] = { ooboff[0], ooboff[1] }; |
cc8bea0a MS |
572 | |
573 | if (DECL_P (base) && TREE_CODE (TREE_TYPE (base)) == ARRAY_TYPE) | |
574 | { | |
56735d40 MS |
575 | /* Check for offset in an anti-range with a negative lower bound. |
576 | For such a range, consider only the non-negative subrange. */ | |
577 | if (offrng[1] < offrng[0] && offrng[1] < 0) | |
cc8bea0a MS |
578 | offrng[1] = maxobjsize; |
579 | } | |
580 | ||
581 | /* Conservative offset of the last byte of the referenced object. */ | |
582 | offset_int endoff; | |
583 | ||
584 | /* The bounds need not be ordered. Set HIB to use as the index | |
585 | of the larger of the bounds and LOB as the opposite. */ | |
586 | bool hib = wi::les_p (offrng[0], offrng[1]); | |
587 | bool lob = !hib; | |
588 | ||
700d4cb0 | 589 | /* Set to the size remaining in the object after subtracting |
6889a3ac MS |
590 | REFOFF. It may become negative as a result of negative indices |
591 | into the enclosing object, such as in: | |
592 | extern struct S { char a[4], b[3], c[1]; } *p; | |
593 | strcpy (p[-3].b, "123"); */ | |
594 | offset_int size = basesize; | |
595 | tree obj = base; | |
596 | ||
597 | const bool decl_p = DECL_P (obj); | |
598 | ||
cc8bea0a MS |
599 | if (basesize < 0) |
600 | { | |
6889a3ac | 601 | endoff = offrng[lob] + (sizrange[0] - wroff); |
cc8bea0a MS |
602 | |
603 | /* For a reference through a pointer to an object of unknown size | |
604 | all initial offsets are considered valid, positive as well as | |
605 | negative, since the pointer itself can point past the beginning | |
606 | of the object. However, the sum of the lower bound of the offset | |
607 | and that of the size must be less than or equal than PTRDIFF_MAX. */ | |
608 | if (endoff > maxobjsize) | |
609 | return error_mark_node; | |
610 | ||
6889a3ac MS |
611 | /* When the referenced subobject is known, the end offset must be |
612 | within its bounds. Otherwise there is nothing to do. */ | |
613 | if (strict | |
614 | && !decl_p | |
615 | && ref | |
616 | && refsize >= 0 | |
617 | && TREE_CODE (ref) == COMPONENT_REF) | |
618 | { | |
619 | /* If REFOFF is negative, SIZE will become negative here. */ | |
620 | size = refoff + refsize; | |
621 | obj = ref; | |
622 | } | |
623 | else | |
624 | return NULL_TREE; | |
cc8bea0a MS |
625 | } |
626 | ||
627 | /* A reference to an object of known size must be within the bounds | |
6889a3ac MS |
628 | of either the base object or the subobject (see above for when |
629 | a subobject can be used). */ | |
630 | if ((decl_p && offrng[hib] < 0) || offrng[lob] > size) | |
631 | return obj; | |
cc8bea0a MS |
632 | |
633 | /* The extent of the reference must also be within the bounds of | |
6889a3ac MS |
634 | the base object (if known) or the subobject or the maximum object |
635 | size otherwise. */ | |
636 | endoff = offrng[lob] + sizrange[0]; | |
cc8bea0a MS |
637 | if (endoff > maxobjsize) |
638 | return error_mark_node; | |
639 | ||
cc8bea0a | 640 | if (strict |
6889a3ac | 641 | && decl_p |
cc8bea0a | 642 | && ref |
6889a3ac MS |
643 | && refsize >= 0 |
644 | && TREE_CODE (ref) == COMPONENT_REF) | |
cc8bea0a | 645 | { |
6889a3ac MS |
646 | /* If the reference is to a member subobject of a declared object, |
647 | the offset must be within the bounds of the subobject. */ | |
648 | size = refoff + refsize; | |
649 | obj = ref; | |
cc8bea0a MS |
650 | } |
651 | ||
652 | if (endoff <= size) | |
653 | return NULL_TREE; | |
654 | ||
655 | /* Set the out-of-bounds offset range to be one greater than | |
656 | that delimited by the reference including its size. */ | |
6889a3ac | 657 | ooboff[lob] = size; |
cc8bea0a MS |
658 | |
659 | if (endoff > ooboff[lob]) | |
6889a3ac | 660 | ooboff[hib] = endoff - 1; |
cc8bea0a | 661 | else |
6889a3ac | 662 | ooboff[hib] = offrng[lob] + sizrange[1]; |
cc8bea0a MS |
663 | |
664 | return obj; | |
665 | } | |
666 | ||
667 | /* Create an association between the memory references DST and SRC | |
668 | for access by a call EXPR to a memory or string built-in funtion. */ | |
669 | ||
e864d395 AH |
670 | builtin_access::builtin_access (range_query *query, gimple *call, |
671 | builtin_memref &dst, | |
cc8bea0a MS |
672 | builtin_memref &src) |
673 | : dstref (&dst), srcref (&src), sizrange (), ovloff (), ovlsiz (), | |
674 | dstoff (), srcoff (), dstsiz (), srcsiz () | |
675 | { | |
6889a3ac MS |
676 | dstoff[0] = dst.offrange[0]; |
677 | dstoff[1] = dst.offrange[1]; | |
678 | ||
cc8bea0a | 679 | /* Zero out since the offset_int ctors invoked above are no-op. */ |
cc8bea0a MS |
680 | srcoff[0] = srcoff[1] = 0; |
681 | dstsiz[0] = dstsiz[1] = 0; | |
682 | srcsiz[0] = srcsiz[1] = 0; | |
683 | ||
684 | /* Object Size Type to use to determine the size of the destination | |
685 | and source objects. Overridden below for raw memory functions. */ | |
686 | int ostype = 1; | |
687 | ||
688 | /* True when the size of one reference depends on the offset of | |
689 | itself or the other. */ | |
690 | bool depends_p = true; | |
691 | ||
692 | /* True when the size of the destination reference DSTREF has been | |
693 | determined from SRCREF and so needs to be adjusted by the latter's | |
694 | offset. Only meaningful for bounded string functions like strncpy. */ | |
695 | bool dstadjust_p = false; | |
696 | ||
697 | /* The size argument number (depends on the built-in). */ | |
698 | unsigned sizeargno = 2; | |
cc8bea0a MS |
699 | |
700 | tree func = gimple_call_fndecl (call); | |
701 | switch (DECL_FUNCTION_CODE (func)) | |
702 | { | |
703 | case BUILT_IN_MEMCPY: | |
704 | case BUILT_IN_MEMCPY_CHK: | |
cc8bea0a MS |
705 | case BUILT_IN_MEMPCPY: |
706 | case BUILT_IN_MEMPCPY_CHK: | |
cc8bea0a MS |
707 | ostype = 0; |
708 | depends_p = false; | |
709 | detect_overlap = &builtin_access::generic_overlap; | |
710 | break; | |
711 | ||
712 | case BUILT_IN_MEMMOVE: | |
713 | case BUILT_IN_MEMMOVE_CHK: | |
cc8bea0a MS |
714 | /* For memmove there is never any overlap to check for. */ |
715 | ostype = 0; | |
716 | depends_p = false; | |
717 | detect_overlap = &builtin_access::no_overlap; | |
718 | break; | |
719 | ||
a411ae9b MS |
720 | case BUILT_IN_MEMSET: |
721 | case BUILT_IN_MEMSET_CHK: | |
722 | /* For memset there is never any overlap to check for. */ | |
723 | ostype = 0; | |
724 | depends_p = false; | |
725 | detect_overlap = &builtin_access::no_overlap; | |
726 | break; | |
727 | ||
cc8bea0a MS |
728 | case BUILT_IN_STPNCPY: |
729 | case BUILT_IN_STPNCPY_CHK: | |
730 | case BUILT_IN_STRNCPY: | |
731 | case BUILT_IN_STRNCPY_CHK: | |
732 | dstref->strbounded_p = true; | |
733 | detect_overlap = &builtin_access::strcpy_overlap; | |
734 | break; | |
735 | ||
736 | case BUILT_IN_STPCPY: | |
737 | case BUILT_IN_STPCPY_CHK: | |
cc8bea0a MS |
738 | case BUILT_IN_STRCPY: |
739 | case BUILT_IN_STRCPY_CHK: | |
cc8bea0a MS |
740 | detect_overlap = &builtin_access::strcpy_overlap; |
741 | break; | |
742 | ||
743 | case BUILT_IN_STRCAT: | |
744 | case BUILT_IN_STRCAT_CHK: | |
cc8bea0a MS |
745 | detect_overlap = &builtin_access::strcat_overlap; |
746 | break; | |
747 | ||
748 | case BUILT_IN_STRNCAT: | |
749 | case BUILT_IN_STRNCAT_CHK: | |
750 | dstref->strbounded_p = true; | |
751 | srcref->strbounded_p = true; | |
752 | detect_overlap = &builtin_access::strcat_overlap; | |
753 | break; | |
754 | ||
755 | default: | |
756 | /* Handle other string functions here whose access may need | |
757 | to be validated for in-bounds offsets and non-overlapping | |
31db0fe0 | 758 | copies. */ |
cc8bea0a MS |
759 | return; |
760 | } | |
761 | ||
a411ae9b | 762 | const offset_int maxobjsize = dst.maxobjsize; |
cc8bea0a MS |
763 | |
764 | /* Try to determine the size of the base object. compute_objsize | |
765 | expects a pointer so create one if BASE is a non-pointer object. */ | |
766 | tree addr; | |
767 | if (dst.basesize < 0) | |
768 | { | |
769 | addr = dst.base; | |
770 | if (!POINTER_TYPE_P (TREE_TYPE (addr))) | |
771 | addr = build1 (ADDR_EXPR, (TREE_TYPE (addr)), addr); | |
772 | ||
773 | if (tree dstsize = compute_objsize (addr, ostype)) | |
774 | dst.basesize = wi::to_offset (dstsize); | |
775 | else if (POINTER_TYPE_P (TREE_TYPE (addr))) | |
776 | dst.basesize = HOST_WIDE_INT_MIN; | |
777 | else | |
778 | dst.basesize = maxobjsize; | |
779 | } | |
780 | ||
a411ae9b | 781 | if (src.base && src.basesize < 0) |
cc8bea0a MS |
782 | { |
783 | addr = src.base; | |
784 | if (!POINTER_TYPE_P (TREE_TYPE (addr))) | |
785 | addr = build1 (ADDR_EXPR, (TREE_TYPE (addr)), addr); | |
786 | ||
787 | if (tree srcsize = compute_objsize (addr, ostype)) | |
788 | src.basesize = wi::to_offset (srcsize); | |
789 | else if (POINTER_TYPE_P (TREE_TYPE (addr))) | |
790 | src.basesize = HOST_WIDE_INT_MIN; | |
791 | else | |
792 | src.basesize = maxobjsize; | |
793 | } | |
794 | ||
6889a3ac MS |
795 | /* Make adjustments for references to the same object by string |
796 | built-in functions to reflect the constraints imposed by | |
797 | the function. */ | |
cc8bea0a MS |
798 | |
799 | /* For bounded string functions determine the range of the bound | |
800 | on the access. For others, the range stays unbounded. */ | |
801 | offset_int bounds[2] = { maxobjsize, maxobjsize }; | |
802 | if (dstref->strbounded_p) | |
803 | { | |
9a0cbb60 MS |
804 | unsigned nargs = gimple_call_num_args (call); |
805 | if (nargs <= sizeargno) | |
806 | return; | |
807 | ||
cc8bea0a MS |
808 | tree size = gimple_call_arg (call, sizeargno); |
809 | tree range[2]; | |
e864d395 | 810 | if (get_size_range (query, size, call, range, true)) |
cc8bea0a MS |
811 | { |
812 | bounds[0] = wi::to_offset (range[0]); | |
813 | bounds[1] = wi::to_offset (range[1]); | |
814 | } | |
815 | ||
816 | /* If both references' size ranges are indeterminate use the last | |
817 | (size) argument from the function call as a substitute. This | |
818 | may only be necessary for strncpy (but not for memcpy where | |
819 | the size range would have been already determined this way). */ | |
820 | if (dstref->sizrange[0] == 0 && dstref->sizrange[1] == maxobjsize | |
821 | && srcref->sizrange[0] == 0 && srcref->sizrange[1] == maxobjsize) | |
822 | { | |
823 | dstref->sizrange[0] = bounds[0]; | |
824 | dstref->sizrange[1] = bounds[1]; | |
825 | } | |
826 | } | |
827 | ||
6889a3ac | 828 | bool dstsize_set = false; |
cc8bea0a MS |
829 | /* The size range of one reference involving the same base object |
830 | can be determined from the size range of the other reference. | |
831 | This makes it possible to compute accurate offsets for warnings | |
832 | involving functions like strcpy where the length of just one of | |
833 | the two arguments is known (determined by tree-ssa-strlen). */ | |
834 | if (dstref->sizrange[0] == 0 && dstref->sizrange[1] == maxobjsize) | |
835 | { | |
836 | /* When the destination size is unknown set it to the size of | |
837 | the source. */ | |
838 | dstref->sizrange[0] = srcref->sizrange[0]; | |
839 | dstref->sizrange[1] = srcref->sizrange[1]; | |
6889a3ac | 840 | dstsize_set = true; |
cc8bea0a MS |
841 | } |
842 | else if (srcref->sizrange[0] == 0 && srcref->sizrange[1] == maxobjsize) | |
843 | { | |
3942060c MS |
844 | /* When the size of the source access is unknown set it to the size |
845 | of the destination first and adjust it later if necessary. */ | |
cc8bea0a MS |
846 | srcref->sizrange[0] = dstref->sizrange[0]; |
847 | srcref->sizrange[1] = dstref->sizrange[1]; | |
848 | ||
849 | if (depends_p) | |
850 | { | |
851 | if (dstref->strbounded_p) | |
852 | { | |
6889a3ac MS |
853 | /* Read access by strncpy is constrained by the third |
854 | argument but except for a zero bound is at least one. */ | |
3942060c MS |
855 | srcref->sizrange[0] = bounds[1] > 0 ? 1 : 0; |
856 | offset_int bound = wi::umin (srcref->basesize, bounds[1]); | |
6889a3ac MS |
857 | if (bound < srcref->sizrange[1]) |
858 | srcref->sizrange[1] = bound; | |
cc8bea0a | 859 | } |
cc8bea0a MS |
860 | /* For string functions, adjust the size range of the source |
861 | reference by the inverse boundaries of the offset (because | |
c7c9468a | 862 | the higher the offset into the string the shorter its |
cc8bea0a | 863 | length). */ |
c7c9468a JL |
864 | if (srcref->offrange[1] >= 0 |
865 | && srcref->offrange[1] < srcref->sizrange[0]) | |
cc8bea0a MS |
866 | srcref->sizrange[0] -= srcref->offrange[1]; |
867 | else | |
3942060c | 868 | srcref->sizrange[0] = 1; |
cc8bea0a MS |
869 | |
870 | if (srcref->offrange[0] > 0) | |
871 | { | |
872 | if (srcref->offrange[0] < srcref->sizrange[1]) | |
873 | srcref->sizrange[1] -= srcref->offrange[0]; | |
874 | else | |
875 | srcref->sizrange[1] = 0; | |
876 | } | |
877 | ||
878 | dstadjust_p = true; | |
879 | } | |
880 | } | |
881 | ||
882 | if (detect_overlap == &builtin_access::generic_overlap) | |
883 | { | |
884 | if (dstref->strbounded_p) | |
885 | { | |
886 | dstref->sizrange[0] = bounds[0]; | |
887 | dstref->sizrange[1] = bounds[1]; | |
888 | ||
889 | if (dstref->sizrange[0] < srcref->sizrange[0]) | |
890 | srcref->sizrange[0] = dstref->sizrange[0]; | |
891 | ||
892 | if (dstref->sizrange[1] < srcref->sizrange[1]) | |
893 | srcref->sizrange[1] = dstref->sizrange[1]; | |
894 | } | |
895 | } | |
896 | else if (detect_overlap == &builtin_access::strcpy_overlap) | |
897 | { | |
898 | if (!dstref->strbounded_p) | |
899 | { | |
900 | /* For strcpy, adjust the destination size range to match that | |
901 | of the source computed above. */ | |
902 | if (depends_p && dstadjust_p) | |
903 | { | |
904 | dstref->sizrange[0] = srcref->sizrange[0]; | |
905 | dstref->sizrange[1] = srcref->sizrange[1]; | |
906 | } | |
907 | } | |
908 | } | |
6889a3ac MS |
909 | else if (!dstsize_set && detect_overlap == &builtin_access::strcat_overlap) |
910 | { | |
911 | dstref->sizrange[0] += srcref->sizrange[0] - 1; | |
912 | dstref->sizrange[1] += srcref->sizrange[1] - 1; | |
913 | } | |
cc8bea0a MS |
914 | |
915 | if (dstref->strbounded_p) | |
916 | { | |
917 | /* For strncpy, adjust the destination size range to match that | |
918 | of the source computed above. */ | |
919 | dstref->sizrange[0] = bounds[0]; | |
920 | dstref->sizrange[1] = bounds[1]; | |
921 | ||
922 | if (bounds[0] < srcref->sizrange[0]) | |
923 | srcref->sizrange[0] = bounds[0]; | |
924 | ||
925 | if (bounds[1] < srcref->sizrange[1]) | |
926 | srcref->sizrange[1] = bounds[1]; | |
927 | } | |
928 | } | |
929 | ||
930 | offset_int | |
931 | builtin_access::overlap_size (const offset_int a[2], const offset_int b[2], | |
932 | offset_int *off) | |
933 | { | |
934 | const offset_int *p = a; | |
935 | const offset_int *q = b; | |
936 | ||
937 | /* Point P at the bigger of the two ranges and Q at the smaller. */ | |
938 | if (wi::lts_p (a[1] - a[0], b[1] - b[0])) | |
939 | { | |
940 | p = b; | |
941 | q = a; | |
942 | } | |
943 | ||
944 | if (p[0] < q[0]) | |
945 | { | |
946 | if (p[1] < q[0]) | |
947 | return 0; | |
948 | ||
949 | *off = q[0]; | |
950 | return wi::smin (p[1], q[1]) - q[0]; | |
951 | } | |
952 | ||
953 | if (q[1] < p[0]) | |
954 | return 0; | |
955 | ||
956 | off[0] = p[0]; | |
957 | return q[1] - p[0]; | |
958 | } | |
959 | ||
960 | /* Return true if the bounded mempry (memcpy amd similar) or string function | |
961 | access (strncpy and similar) ACS overlaps. */ | |
962 | ||
963 | bool | |
964 | builtin_access::generic_overlap () | |
965 | { | |
966 | builtin_access &acs = *this; | |
967 | const builtin_memref *dstref = acs.dstref; | |
968 | const builtin_memref *srcref = acs.srcref; | |
969 | ||
970 | gcc_assert (dstref->base == srcref->base); | |
971 | ||
a411ae9b | 972 | const offset_int maxobjsize = acs.dstref->maxobjsize; |
cc8bea0a MS |
973 | |
974 | offset_int maxsize = dstref->basesize < 0 ? maxobjsize : dstref->basesize; | |
cc8bea0a MS |
975 | |
976 | /* Adjust the larger bounds of the offsets (which may be the first | |
977 | element if the lower bound is larger than the upper bound) to | |
978 | make them valid for the smallest access (if possible) but no smaller | |
979 | than the smaller bounds. */ | |
980 | gcc_assert (wi::les_p (acs.dstoff[0], acs.dstoff[1])); | |
981 | ||
982 | if (maxsize < acs.dstoff[1] + acs.dstsiz[0]) | |
983 | acs.dstoff[1] = maxsize - acs.dstsiz[0]; | |
984 | if (acs.dstoff[1] < acs.dstoff[0]) | |
985 | acs.dstoff[1] = acs.dstoff[0]; | |
986 | ||
987 | gcc_assert (wi::les_p (acs.srcoff[0], acs.srcoff[1])); | |
988 | ||
989 | if (maxsize < acs.srcoff[1] + acs.srcsiz[0]) | |
990 | acs.srcoff[1] = maxsize - acs.srcsiz[0]; | |
991 | if (acs.srcoff[1] < acs.srcoff[0]) | |
992 | acs.srcoff[1] = acs.srcoff[0]; | |
993 | ||
994 | /* Determine the minimum and maximum space for the access given | |
995 | the offsets. */ | |
996 | offset_int space[2]; | |
997 | space[0] = wi::abs (acs.dstoff[0] - acs.srcoff[0]); | |
998 | space[1] = space[0]; | |
999 | ||
1000 | offset_int d = wi::abs (acs.dstoff[0] - acs.srcoff[1]); | |
1001 | if (acs.srcsiz[0] > 0) | |
1002 | { | |
1003 | if (d < space[0]) | |
1004 | space[0] = d; | |
1005 | ||
1006 | if (space[1] < d) | |
1007 | space[1] = d; | |
1008 | } | |
1009 | else | |
1010 | space[1] = acs.dstsiz[1]; | |
1011 | ||
1012 | d = wi::abs (acs.dstoff[1] - acs.srcoff[0]); | |
1013 | if (d < space[0]) | |
1014 | space[0] = d; | |
1015 | ||
1016 | if (space[1] < d) | |
1017 | space[1] = d; | |
1018 | ||
1019 | /* Treat raw memory functions both of whose references are bounded | |
1020 | as special and permit uncertain overlaps to go undetected. For | |
1021 | all kinds of constant offset and constant size accesses, if | |
1022 | overlap isn't certain it is not possible. */ | |
1023 | bool overlap_possible = space[0] < acs.dstsiz[1]; | |
1024 | if (!overlap_possible) | |
1025 | return false; | |
1026 | ||
1027 | bool overlap_certain = space[1] < acs.dstsiz[0]; | |
1028 | ||
1029 | /* True when the size of one reference depends on the offset of | |
1030 | the other. */ | |
1031 | bool depends_p = detect_overlap != &builtin_access::generic_overlap; | |
1032 | ||
5e27f0d5 MS |
1033 | if (!overlap_certain) |
1034 | { | |
1035 | if (!dstref->strbounded_p && !depends_p) | |
8286793a | 1036 | /* Memcpy only considers certain overlap. */ |
5e27f0d5 MS |
1037 | return false; |
1038 | ||
1039 | /* There's no way to distinguish an access to the same member | |
1040 | of a structure from one to two distinct members of the same | |
1041 | structure. Give up to avoid excessive false positives. */ | |
8286793a MS |
1042 | tree basetype = TREE_TYPE (dstref->base); |
1043 | ||
1044 | if (POINTER_TYPE_P (basetype)) | |
1045 | basetype = TREE_TYPE (basetype); | |
1046 | else | |
1047 | while (TREE_CODE (basetype) == ARRAY_TYPE) | |
1048 | basetype = TREE_TYPE (basetype); | |
1049 | ||
5e27f0d5 MS |
1050 | if (RECORD_OR_UNION_TYPE_P (basetype)) |
1051 | return false; | |
1052 | } | |
cc8bea0a MS |
1053 | |
1054 | /* True for stpcpy and strcpy. */ | |
1055 | bool stxcpy_p = (!dstref->strbounded_p | |
1056 | && detect_overlap == &builtin_access::strcpy_overlap); | |
1057 | ||
1058 | if (dstref->refoff >= 0 | |
1059 | && srcref->refoff >= 0 | |
1060 | && dstref->refoff != srcref->refoff | |
1061 | && (stxcpy_p || dstref->strbounded_p || srcref->strbounded_p)) | |
1062 | return false; | |
1063 | ||
1064 | offset_int siz[2] = { maxobjsize + 1, 0 }; | |
1065 | ||
1066 | ovloff[0] = HOST_WIDE_INT_MAX; | |
1067 | ovloff[1] = HOST_WIDE_INT_MIN; | |
1068 | ||
cc8bea0a MS |
1069 | if (stxcpy_p) |
1070 | { | |
cc8bea0a MS |
1071 | /* Iterate over the extreme locations (on the horizontal axis formed |
1072 | by their offsets) and sizes of two regions and find their smallest | |
1073 | and largest overlap and the corresponding offsets. */ | |
1074 | for (unsigned i = 0; i != 2; ++i) | |
1075 | { | |
1076 | const offset_int a[2] = { | |
1077 | acs.dstoff[i], acs.dstoff[i] + acs.dstsiz[!i] | |
1078 | }; | |
1079 | ||
1080 | const offset_int b[2] = { | |
1081 | acs.srcoff[i], acs.srcoff[i] + acs.srcsiz[!i] | |
1082 | }; | |
1083 | ||
1084 | offset_int off; | |
1085 | offset_int sz = overlap_size (a, b, &off); | |
1086 | if (sz < siz[0]) | |
1087 | siz[0] = sz; | |
1088 | ||
1089 | if (siz[1] <= sz) | |
1090 | siz[1] = sz; | |
1091 | ||
1092 | if (sz != 0) | |
1093 | { | |
1094 | if (wi::lts_p (off, ovloff[0])) | |
1095 | ovloff[0] = off.to_shwi (); | |
1096 | if (wi::lts_p (ovloff[1], off)) | |
1097 | ovloff[1] = off.to_shwi (); | |
1098 | } | |
1099 | } | |
1100 | } | |
1101 | else | |
1102 | { | |
cc8bea0a | 1103 | /* Iterate over the extreme locations (on the horizontal axis |
3942060c MS |
1104 | formed by their offsets) and sizes of the two regions and |
1105 | find their smallest and largest overlap and the corresponding | |
cc8bea0a MS |
1106 | offsets. */ |
1107 | ||
1108 | for (unsigned io = 0; io != 2; ++io) | |
1109 | for (unsigned is = 0; is != 2; ++is) | |
1110 | { | |
1111 | const offset_int a[2] = { | |
1112 | acs.dstoff[io], acs.dstoff[io] + acs.dstsiz[is] | |
1113 | }; | |
1114 | ||
1115 | for (unsigned jo = 0; jo != 2; ++jo) | |
1116 | for (unsigned js = 0; js != 2; ++js) | |
1117 | { | |
cc8bea0a MS |
1118 | const offset_int b[2] = { |
1119 | acs.srcoff[jo], acs.srcoff[jo] + acs.srcsiz[js] | |
1120 | }; | |
1121 | ||
1122 | offset_int off; | |
1123 | offset_int sz = overlap_size (a, b, &off); | |
1124 | if (sz < siz[0]) | |
1125 | siz[0] = sz; | |
1126 | ||
1127 | if (siz[1] <= sz) | |
1128 | siz[1] = sz; | |
1129 | ||
1130 | if (sz != 0) | |
1131 | { | |
1132 | if (wi::lts_p (off, ovloff[0])) | |
1133 | ovloff[0] = off.to_shwi (); | |
1134 | if (wi::lts_p (ovloff[1], off)) | |
1135 | ovloff[1] = off.to_shwi (); | |
1136 | } | |
1137 | } | |
1138 | } | |
1139 | } | |
1140 | ||
1141 | ovlsiz[0] = siz[0].to_shwi (); | |
1142 | ovlsiz[1] = siz[1].to_shwi (); | |
1143 | ||
3942060c | 1144 | /* Adjust the overlap offset range to reflect the overlap size range. */ |
cc8bea0a | 1145 | if (ovlsiz[0] == 0 && ovlsiz[1] > 1) |
3942060c | 1146 | ovloff[1] = ovloff[0] + ovlsiz[1] - 1; |
cc8bea0a MS |
1147 | |
1148 | return true; | |
1149 | } | |
1150 | ||
1151 | /* Return true if the strcat-like access overlaps. */ | |
1152 | ||
1153 | bool | |
1154 | builtin_access::strcat_overlap () | |
1155 | { | |
1156 | builtin_access &acs = *this; | |
1157 | const builtin_memref *dstref = acs.dstref; | |
1158 | const builtin_memref *srcref = acs.srcref; | |
1159 | ||
1160 | gcc_assert (dstref->base == srcref->base); | |
1161 | ||
a411ae9b | 1162 | const offset_int maxobjsize = acs.dstref->maxobjsize; |
cc8bea0a MS |
1163 | |
1164 | gcc_assert (dstref->base && dstref->base == srcref->base); | |
1165 | ||
1166 | /* Adjust for strcat-like accesses. */ | |
1167 | ||
1168 | /* As a special case for strcat, set the DSTREF offsets to the length | |
6889a3ac MS |
1169 | of the destination string since the function starts writing over |
1170 | its terminating nul, and set the destination size to 1 for the length | |
1171 | of the nul. */ | |
1172 | acs.dstoff[0] += dstsiz[0] - srcref->sizrange[0]; | |
1173 | acs.dstoff[1] += dstsiz[1] - srcref->sizrange[1]; | |
cc8bea0a MS |
1174 | |
1175 | bool strfunc_unknown_args = acs.dstsiz[0] == 0 && acs.dstsiz[1] != 0; | |
1176 | ||
1177 | /* The lower bound is zero when the size is unknown because then | |
1178 | overlap is not certain. */ | |
1179 | acs.dstsiz[0] = strfunc_unknown_args ? 0 : 1; | |
1180 | acs.dstsiz[1] = 1; | |
1181 | ||
1182 | offset_int maxsize = dstref->basesize < 0 ? maxobjsize : dstref->basesize; | |
cc8bea0a MS |
1183 | |
1184 | /* For references to the same base object, determine if there's a pair | |
1185 | of valid offsets into the two references such that access between | |
1186 | them doesn't overlap. Adjust both upper bounds to be valid for | |
1187 | the smaller size (i.e., at most MAXSIZE - SIZE). */ | |
1188 | ||
1189 | if (maxsize < acs.dstoff[1] + acs.dstsiz[0]) | |
1190 | acs.dstoff[1] = maxsize - acs.dstsiz[0]; | |
1191 | ||
1192 | if (maxsize < acs.srcoff[1] + acs.srcsiz[0]) | |
1193 | acs.srcoff[1] = maxsize - acs.srcsiz[0]; | |
1194 | ||
1195 | /* Check to see if there's enough space for both accesses without | |
1196 | overlap. Determine the optimistic (maximum) amount of available | |
1197 | space. */ | |
1198 | offset_int space; | |
1199 | if (acs.dstoff[0] <= acs.srcoff[0]) | |
1200 | { | |
1201 | if (acs.dstoff[1] < acs.srcoff[1]) | |
1202 | space = acs.srcoff[1] + acs.srcsiz[0] - acs.dstoff[0]; | |
1203 | else | |
1204 | space = acs.dstoff[1] + acs.dstsiz[0] - acs.srcoff[0]; | |
1205 | } | |
1206 | else | |
1207 | space = acs.dstoff[1] + acs.dstsiz[0] - acs.srcoff[0]; | |
1208 | ||
1209 | /* Overlap is certain if the distance between the farthest offsets | |
1210 | of the opposite accesses is less than the sum of the lower bounds | |
1211 | of the sizes of the two accesses. */ | |
1212 | bool overlap_certain = space < acs.dstsiz[0] + acs.srcsiz[0]; | |
1213 | ||
1214 | /* For a constant-offset, constant size access, consider the largest | |
1215 | distance between the offset bounds and the lower bound of the access | |
1216 | size. If the overlap isn't certain return success. */ | |
1217 | if (!overlap_certain | |
1218 | && acs.dstoff[0] == acs.dstoff[1] | |
1219 | && acs.srcoff[0] == acs.srcoff[1] | |
1220 | && acs.dstsiz[0] == acs.dstsiz[1] | |
1221 | && acs.srcsiz[0] == acs.srcsiz[1]) | |
1222 | return false; | |
1223 | ||
1224 | /* Overlap is not certain but may be possible. */ | |
1225 | ||
1226 | offset_int access_min = acs.dstsiz[0] + acs.srcsiz[0]; | |
1227 | ||
1228 | /* Determine the conservative (minimum) amount of space. */ | |
1229 | space = wi::abs (acs.dstoff[0] - acs.srcoff[0]); | |
1230 | offset_int d = wi::abs (acs.dstoff[0] - acs.srcoff[1]); | |
1231 | if (d < space) | |
1232 | space = d; | |
1233 | d = wi::abs (acs.dstoff[1] - acs.srcoff[0]); | |
1234 | if (d < space) | |
1235 | space = d; | |
1236 | ||
1237 | /* For a strict test (used for strcpy and similar with unknown or | |
1238 | variable bounds or sizes), consider the smallest distance between | |
1239 | the offset bounds and either the upper bound of the access size | |
1240 | if known, or the lower bound otherwise. */ | |
1241 | if (access_min <= space && (access_min != 0 || !strfunc_unknown_args)) | |
1242 | return false; | |
1243 | ||
1244 | /* When strcat overlap is certain it is always a single byte: | |
816fad6e | 1245 | the terminating NUL, regardless of offsets and sizes. When |
cc8bea0a MS |
1246 | overlap is only possible its range is [0, 1]. */ |
1247 | acs.ovlsiz[0] = dstref->sizrange[0] == dstref->sizrange[1] ? 1 : 0; | |
1248 | acs.ovlsiz[1] = 1; | |
cc8bea0a | 1249 | |
6889a3ac MS |
1250 | offset_int endoff |
1251 | = dstref->offrange[0] + (dstref->sizrange[0] - srcref->sizrange[0]); | |
816fad6e MS |
1252 | if (endoff <= srcref->offrange[0]) |
1253 | acs.ovloff[0] = wi::smin (maxobjsize, srcref->offrange[0]).to_shwi (); | |
1254 | else | |
1255 | acs.ovloff[0] = wi::smin (maxobjsize, endoff).to_shwi (); | |
1256 | ||
1257 | acs.sizrange[0] = wi::smax (wi::abs (endoff - srcref->offrange[0]) + 1, | |
1258 | srcref->sizrange[0]).to_shwi (); | |
1259 | if (dstref->offrange[0] == dstref->offrange[1]) | |
1260 | { | |
1261 | if (srcref->offrange[0] == srcref->offrange[1]) | |
1262 | acs.ovloff[1] = acs.ovloff[0]; | |
1263 | else | |
1264 | acs.ovloff[1] | |
1265 | = wi::smin (maxobjsize, | |
1266 | srcref->offrange[1] + srcref->sizrange[1]).to_shwi (); | |
1267 | } | |
1268 | else | |
1269 | acs.ovloff[1] | |
1270 | = wi::smin (maxobjsize, | |
1271 | dstref->offrange[1] + dstref->sizrange[1]).to_shwi (); | |
1272 | ||
1273 | if (acs.sizrange[0] == 0) | |
1274 | acs.sizrange[0] = 1; | |
cc8bea0a MS |
1275 | acs.sizrange[1] = wi::smax (acs.dstsiz[1], srcref->sizrange[1]).to_shwi (); |
1276 | return true; | |
1277 | } | |
1278 | ||
1279 | /* Return true if the strcpy-like access overlaps. */ | |
1280 | ||
1281 | bool | |
1282 | builtin_access::strcpy_overlap () | |
1283 | { | |
1284 | return generic_overlap (); | |
1285 | } | |
1286 | ||
a2c2cee9 MS |
1287 | /* For a BASE of array type, clamp REFOFF to at most [0, BASE_SIZE] |
1288 | if known, or [0, MAXOBJSIZE] otherwise. */ | |
1289 | ||
1290 | static void | |
1291 | clamp_offset (tree base, offset_int refoff[2], offset_int maxobjsize) | |
1292 | { | |
1293 | if (!base || TREE_CODE (TREE_TYPE (base)) != ARRAY_TYPE) | |
1294 | return; | |
1295 | ||
1296 | if (refoff[0] < 0 && refoff[1] >= 0) | |
1297 | refoff[0] = 0; | |
1298 | ||
1299 | if (refoff[1] < refoff[0]) | |
1300 | { | |
1301 | offset_int maxsize = maxobjsize; | |
1302 | if (tree size = TYPE_SIZE_UNIT (TREE_TYPE (base))) | |
1303 | maxsize = wi::to_offset (size); | |
1304 | ||
1305 | refoff[1] = wi::umin (refoff[1], maxsize); | |
1306 | } | |
1307 | } | |
cc8bea0a MS |
1308 | |
1309 | /* Return true if DSTREF and SRCREF describe accesses that either overlap | |
1310 | one another or that, in order not to overlap, would imply that the size | |
1311 | of the referenced object(s) exceeds the maximum size of an object. Set | |
1312 | Otherwise, if DSTREF and SRCREF do not definitely overlap (even though | |
1313 | they may overlap in a way that's not apparent from the available data), | |
1314 | return false. */ | |
1315 | ||
1316 | bool | |
1317 | builtin_access::overlap () | |
1318 | { | |
1319 | builtin_access &acs = *this; | |
1320 | ||
a411ae9b | 1321 | const offset_int maxobjsize = dstref->maxobjsize; |
cc8bea0a MS |
1322 | |
1323 | acs.sizrange[0] = wi::smax (dstref->sizrange[0], | |
1324 | srcref->sizrange[0]).to_shwi (); | |
1325 | acs.sizrange[1] = wi::smax (dstref->sizrange[1], | |
1326 | srcref->sizrange[1]).to_shwi (); | |
1327 | ||
1328 | /* Check to see if the two references refer to regions that are | |
1329 | too large not to overlap in the address space (whose maximum | |
1330 | size is PTRDIFF_MAX). */ | |
1331 | offset_int size = dstref->sizrange[0] + srcref->sizrange[0]; | |
1332 | if (maxobjsize < size) | |
1333 | { | |
1334 | acs.ovloff[0] = (maxobjsize - dstref->sizrange[0]).to_shwi (); | |
1335 | acs.ovlsiz[0] = (size - maxobjsize).to_shwi (); | |
1336 | return true; | |
1337 | } | |
1338 | ||
1339 | /* If both base objects aren't known return the maximum possible | |
1340 | offset that would make them not overlap. */ | |
1341 | if (!dstref->base || !srcref->base) | |
1342 | return false; | |
1343 | ||
c7c9468a JL |
1344 | /* If the base object is an array adjust the bounds of the offset |
1345 | to be non-negative and within the bounds of the array if possible. */ | |
a2c2cee9 | 1346 | clamp_offset (dstref->base, acs.dstoff, maxobjsize); |
c7c9468a JL |
1347 | |
1348 | acs.srcoff[0] = srcref->offrange[0]; | |
1349 | acs.srcoff[1] = srcref->offrange[1]; | |
cc8bea0a | 1350 | |
a2c2cee9 | 1351 | clamp_offset (srcref->base, acs.srcoff, maxobjsize); |
cc8bea0a | 1352 | |
c7c9468a JL |
1353 | /* When the upper bound of the offset is less than the lower bound |
1354 | the former is the result of a negative offset being represented | |
1355 | as a large positive value or vice versa. The resulting range is | |
1356 | a union of two subranges: [MIN, UB] and [LB, MAX]. Since such | |
1357 | a union is not representable using the current data structure | |
1358 | replace it with the full range of offsets. */ | |
cc8bea0a | 1359 | if (acs.dstoff[1] < acs.dstoff[0]) |
c7c9468a JL |
1360 | { |
1361 | acs.dstoff[0] = -maxobjsize - 1; | |
1362 | acs.dstoff[1] = maxobjsize; | |
1363 | } | |
cc8bea0a MS |
1364 | |
1365 | /* Validate the offset and size of each reference on its own first. | |
1366 | This is independent of whether or not the base objects are the | |
1367 | same. Normally, this would have already been detected and | |
1368 | diagnosed by -Warray-bounds, unless it has been disabled. */ | |
1369 | offset_int maxoff = acs.dstoff[0] + dstref->sizrange[0]; | |
1370 | if (maxobjsize < maxoff) | |
1371 | { | |
1372 | acs.ovlsiz[0] = (maxoff - maxobjsize).to_shwi (); | |
1373 | acs.ovloff[0] = acs.dstoff[0].to_shwi () - acs.ovlsiz[0]; | |
1374 | return true; | |
1375 | } | |
1376 | ||
1377 | /* Repeat the same as above but for the source offsets. */ | |
1378 | if (acs.srcoff[1] < acs.srcoff[0]) | |
c7c9468a JL |
1379 | { |
1380 | acs.srcoff[0] = -maxobjsize - 1; | |
1381 | acs.srcoff[1] = maxobjsize; | |
1382 | } | |
cc8bea0a MS |
1383 | |
1384 | maxoff = acs.srcoff[0] + srcref->sizrange[0]; | |
1385 | if (maxobjsize < maxoff) | |
1386 | { | |
1387 | acs.ovlsiz[0] = (maxoff - maxobjsize).to_shwi (); | |
1388 | acs.ovlsiz[1] = (acs.srcoff[0] + srcref->sizrange[1] | |
1389 | - maxobjsize).to_shwi (); | |
1390 | acs.ovloff[0] = acs.srcoff[0].to_shwi () - acs.ovlsiz[0]; | |
1391 | return true; | |
1392 | } | |
1393 | ||
1394 | if (dstref->base != srcref->base) | |
1395 | return false; | |
1396 | ||
1397 | acs.dstsiz[0] = dstref->sizrange[0]; | |
1398 | acs.dstsiz[1] = dstref->sizrange[1]; | |
1399 | ||
1400 | acs.srcsiz[0] = srcref->sizrange[0]; | |
1401 | acs.srcsiz[1] = srcref->sizrange[1]; | |
1402 | ||
1403 | /* Call the appropriate function to determine the overlap. */ | |
1404 | if ((this->*detect_overlap) ()) | |
1405 | { | |
816fad6e MS |
1406 | if (!sizrange[1]) |
1407 | { | |
1408 | /* Unless the access size range has already been set, do so here. */ | |
1409 | sizrange[0] = wi::smax (acs.dstsiz[0], srcref->sizrange[0]).to_shwi (); | |
1410 | sizrange[1] = wi::smax (acs.dstsiz[1], srcref->sizrange[1]).to_shwi (); | |
1411 | } | |
cc8bea0a MS |
1412 | return true; |
1413 | } | |
1414 | ||
1415 | return false; | |
1416 | } | |
1417 | ||
1418 | /* Attempt to detect and diagnose an overlapping copy in a call expression | |
700d4cb0 | 1419 | EXPR involving an access ACS to a built-in memory or string function. |
cc8bea0a MS |
1420 | Return true when one has been detected, false otherwise. */ |
1421 | ||
1422 | static bool | |
8a45b051 | 1423 | maybe_diag_overlap (location_t loc, gimple *call, builtin_access &acs) |
cc8bea0a MS |
1424 | { |
1425 | if (!acs.overlap ()) | |
1426 | return false; | |
1427 | ||
213694e5 MS |
1428 | if (gimple_no_warning_p (call)) |
1429 | return true; | |
1430 | ||
cc8bea0a MS |
1431 | /* For convenience. */ |
1432 | const builtin_memref &dstref = *acs.dstref; | |
1433 | const builtin_memref &srcref = *acs.srcref; | |
1434 | ||
1435 | /* Determine the range of offsets and sizes of the overlap if it | |
1436 | exists and issue diagnostics. */ | |
1437 | HOST_WIDE_INT *ovloff = acs.ovloff; | |
1438 | HOST_WIDE_INT *ovlsiz = acs.ovlsiz; | |
1439 | HOST_WIDE_INT *sizrange = acs.sizrange; | |
1440 | ||
1441 | tree func = gimple_call_fndecl (call); | |
1442 | ||
1443 | /* To avoid a combinatorial explosion of diagnostics format the offsets | |
1444 | or their ranges as strings and use them in the warning calls below. */ | |
1445 | char offstr[3][64]; | |
1446 | ||
1447 | if (dstref.offrange[0] == dstref.offrange[1] | |
1448 | || dstref.offrange[1] > HOST_WIDE_INT_MAX) | |
a6fd2cd7 MS |
1449 | sprintf (offstr[0], HOST_WIDE_INT_PRINT_DEC, |
1450 | dstref.offrange[0].to_shwi ()); | |
cc8bea0a | 1451 | else |
a6fd2cd7 MS |
1452 | sprintf (offstr[0], |
1453 | "[" HOST_WIDE_INT_PRINT_DEC ", " HOST_WIDE_INT_PRINT_DEC "]", | |
1454 | dstref.offrange[0].to_shwi (), | |
1455 | dstref.offrange[1].to_shwi ()); | |
cc8bea0a MS |
1456 | |
1457 | if (srcref.offrange[0] == srcref.offrange[1] | |
1458 | || srcref.offrange[1] > HOST_WIDE_INT_MAX) | |
a6fd2cd7 MS |
1459 | sprintf (offstr[1], |
1460 | HOST_WIDE_INT_PRINT_DEC, | |
1461 | srcref.offrange[0].to_shwi ()); | |
cc8bea0a | 1462 | else |
a6fd2cd7 MS |
1463 | sprintf (offstr[1], |
1464 | "[" HOST_WIDE_INT_PRINT_DEC ", " HOST_WIDE_INT_PRINT_DEC "]", | |
1465 | srcref.offrange[0].to_shwi (), | |
1466 | srcref.offrange[1].to_shwi ()); | |
cc8bea0a MS |
1467 | |
1468 | if (ovloff[0] == ovloff[1] || !ovloff[1]) | |
a6fd2cd7 | 1469 | sprintf (offstr[2], HOST_WIDE_INT_PRINT_DEC, ovloff[0]); |
cc8bea0a | 1470 | else |
a6fd2cd7 MS |
1471 | sprintf (offstr[2], |
1472 | "[" HOST_WIDE_INT_PRINT_DEC ", " HOST_WIDE_INT_PRINT_DEC "]", | |
1473 | ovloff[0], ovloff[1]); | |
cc8bea0a | 1474 | |
a411ae9b | 1475 | const offset_int maxobjsize = dstref.maxobjsize; |
cc8bea0a MS |
1476 | bool must_overlap = ovlsiz[0] > 0; |
1477 | ||
1478 | if (ovlsiz[1] == 0) | |
1479 | ovlsiz[1] = ovlsiz[0]; | |
1480 | ||
1481 | if (must_overlap) | |
1482 | { | |
1483 | /* Issue definitive "overlaps" diagnostic in this block. */ | |
1484 | ||
1485 | if (sizrange[0] == sizrange[1]) | |
1486 | { | |
1487 | if (ovlsiz[0] == ovlsiz[1]) | |
1488 | warning_at (loc, OPT_Wrestrict, | |
1489 | sizrange[0] == 1 | |
1490 | ? (ovlsiz[0] == 1 | |
1491 | ? G_("%G%qD accessing %wu byte at offsets %s " | |
1492 | "and %s overlaps %wu byte at offset %s") | |
1493 | : G_("%G%qD accessing %wu byte at offsets %s " | |
1494 | "and %s overlaps %wu bytes at offset " | |
1495 | "%s")) | |
1496 | : (ovlsiz[0] == 1 | |
1497 | ? G_("%G%qD accessing %wu bytes at offsets %s " | |
1498 | "and %s overlaps %wu byte at offset %s") | |
1499 | : G_("%G%qD accessing %wu bytes at offsets %s " | |
1500 | "and %s overlaps %wu bytes at offset " | |
1501 | "%s")), | |
1502 | call, func, sizrange[0], | |
1503 | offstr[0], offstr[1], ovlsiz[0], offstr[2]); | |
1504 | else if (ovlsiz[1] >= 0 && ovlsiz[1] < maxobjsize.to_shwi ()) | |
15d3974b JJ |
1505 | warning_n (loc, OPT_Wrestrict, sizrange[0], |
1506 | "%G%qD accessing %wu byte at offsets %s " | |
1507 | "and %s overlaps between %wu and %wu bytes " | |
1508 | "at offset %s", | |
1509 | "%G%qD accessing %wu bytes at offsets %s " | |
1510 | "and %s overlaps between %wu and %wu bytes " | |
1511 | "at offset %s", | |
1512 | call, func, sizrange[0], offstr[0], offstr[1], | |
1513 | ovlsiz[0], ovlsiz[1], offstr[2]); | |
cc8bea0a | 1514 | else |
15d3974b JJ |
1515 | warning_n (loc, OPT_Wrestrict, sizrange[0], |
1516 | "%G%qD accessing %wu byte at offsets %s and " | |
1517 | "%s overlaps %wu or more bytes at offset %s", | |
1518 | "%G%qD accessing %wu bytes at offsets %s and " | |
1519 | "%s overlaps %wu or more bytes at offset %s", | |
1520 | call, func, sizrange[0], | |
1521 | offstr[0], offstr[1], ovlsiz[0], offstr[2]); | |
cc8bea0a MS |
1522 | return true; |
1523 | } | |
1524 | ||
1525 | if (sizrange[1] >= 0 && sizrange[1] < maxobjsize.to_shwi ()) | |
1526 | { | |
1527 | if (ovlsiz[0] == ovlsiz[1]) | |
15d3974b JJ |
1528 | warning_n (loc, OPT_Wrestrict, ovlsiz[0], |
1529 | "%G%qD accessing between %wu and %wu bytes " | |
1530 | "at offsets %s and %s overlaps %wu byte at " | |
1531 | "offset %s", | |
1532 | "%G%qD accessing between %wu and %wu bytes " | |
1533 | "at offsets %s and %s overlaps %wu bytes " | |
1534 | "at offset %s", | |
1535 | call, func, sizrange[0], sizrange[1], | |
1536 | offstr[0], offstr[1], ovlsiz[0], offstr[2]); | |
cc8bea0a MS |
1537 | else if (ovlsiz[1] >= 0 && ovlsiz[1] < maxobjsize.to_shwi ()) |
1538 | warning_at (loc, OPT_Wrestrict, | |
1539 | "%G%qD accessing between %wu and %wu bytes at " | |
1540 | "offsets %s and %s overlaps between %wu and %wu " | |
1541 | "bytes at offset %s", | |
1542 | call, func, sizrange[0], sizrange[1], | |
1543 | offstr[0], offstr[1], ovlsiz[0], ovlsiz[1], | |
1544 | offstr[2]); | |
1545 | else | |
1546 | warning_at (loc, OPT_Wrestrict, | |
1547 | "%G%qD accessing between %wu and %wu bytes at " | |
1548 | "offsets %s and %s overlaps %wu or more bytes " | |
1549 | "at offset %s", | |
1550 | call, func, sizrange[0], sizrange[1], | |
1551 | offstr[0], offstr[1], ovlsiz[0], offstr[2]); | |
1552 | return true; | |
1553 | } | |
1554 | ||
1555 | if (ovlsiz[0] != ovlsiz[1]) | |
1556 | ovlsiz[1] = maxobjsize.to_shwi (); | |
1557 | ||
1558 | if (ovlsiz[0] == ovlsiz[1]) | |
15d3974b JJ |
1559 | warning_n (loc, OPT_Wrestrict, ovlsiz[0], |
1560 | "%G%qD accessing %wu or more bytes at offsets " | |
1561 | "%s and %s overlaps %wu byte at offset %s", | |
1562 | "%G%qD accessing %wu or more bytes at offsets " | |
1563 | "%s and %s overlaps %wu bytes at offset %s", | |
1564 | call, func, sizrange[0], offstr[0], offstr[1], | |
1565 | ovlsiz[0], offstr[2]); | |
cc8bea0a MS |
1566 | else if (ovlsiz[1] >= 0 && ovlsiz[1] < maxobjsize.to_shwi ()) |
1567 | warning_at (loc, OPT_Wrestrict, | |
1568 | "%G%qD accessing %wu or more bytes at offsets %s " | |
1569 | "and %s overlaps between %wu and %wu bytes " | |
1570 | "at offset %s", | |
1571 | call, func, sizrange[0], offstr[0], offstr[1], | |
1572 | ovlsiz[0], ovlsiz[1], offstr[2]); | |
1573 | else | |
1574 | warning_at (loc, OPT_Wrestrict, | |
1575 | "%G%qD accessing %wu or more bytes at offsets %s " | |
1576 | "and %s overlaps %wu or more bytes at offset %s", | |
1577 | call, func, sizrange[0], offstr[0], offstr[1], | |
1578 | ovlsiz[0], offstr[2]); | |
1579 | return true; | |
1580 | } | |
1581 | ||
cc8bea0a MS |
1582 | /* Use more concise wording when one of the offsets is unbounded |
1583 | to avoid confusing the user with large and mostly meaningless | |
1584 | numbers. */ | |
816fad6e MS |
1585 | bool open_range; |
1586 | if (DECL_P (dstref.base) && TREE_CODE (TREE_TYPE (dstref.base)) == ARRAY_TYPE) | |
1587 | open_range = ((dstref.offrange[0] == 0 | |
1588 | && dstref.offrange[1] == maxobjsize) | |
1589 | || (srcref.offrange[0] == 0 | |
1590 | && srcref.offrange[1] == maxobjsize)); | |
1591 | else | |
1592 | open_range = ((dstref.offrange[0] == -maxobjsize - 1 | |
1593 | && dstref.offrange[1] == maxobjsize) | |
1594 | || (srcref.offrange[0] == -maxobjsize - 1 | |
1595 | && srcref.offrange[1] == maxobjsize)); | |
cc8bea0a MS |
1596 | |
1597 | if (sizrange[0] == sizrange[1] || sizrange[1] == 1) | |
1598 | { | |
1599 | if (ovlsiz[1] == 1) | |
1600 | { | |
1601 | if (open_range) | |
15d3974b JJ |
1602 | warning_n (loc, OPT_Wrestrict, sizrange[1], |
1603 | "%G%qD accessing %wu byte may overlap " | |
1604 | "%wu byte", | |
1605 | "%G%qD accessing %wu bytes may overlap " | |
1606 | "%wu byte", | |
1607 | call, func, sizrange[1], ovlsiz[1]); | |
cc8bea0a | 1608 | else |
15d3974b JJ |
1609 | warning_n (loc, OPT_Wrestrict, sizrange[1], |
1610 | "%G%qD accessing %wu byte at offsets %s " | |
1611 | "and %s may overlap %wu byte at offset %s", | |
1612 | "%G%qD accessing %wu bytes at offsets %s " | |
1613 | "and %s may overlap %wu byte at offset %s", | |
1614 | call, func, sizrange[1], offstr[0], offstr[1], | |
1615 | ovlsiz[1], offstr[2]); | |
cc8bea0a MS |
1616 | return true; |
1617 | } | |
1618 | ||
1619 | if (open_range) | |
15d3974b JJ |
1620 | warning_n (loc, OPT_Wrestrict, sizrange[1], |
1621 | "%G%qD accessing %wu byte may overlap " | |
1622 | "up to %wu bytes", | |
1623 | "%G%qD accessing %wu bytes may overlap " | |
1624 | "up to %wu bytes", | |
1625 | call, func, sizrange[1], ovlsiz[1]); | |
cc8bea0a | 1626 | else |
15d3974b JJ |
1627 | warning_n (loc, OPT_Wrestrict, sizrange[1], |
1628 | "%G%qD accessing %wu byte at offsets %s and " | |
1629 | "%s may overlap up to %wu bytes at offset %s", | |
1630 | "%G%qD accessing %wu bytes at offsets %s and " | |
1631 | "%s may overlap up to %wu bytes at offset %s", | |
1632 | call, func, sizrange[1], offstr[0], offstr[1], | |
1633 | ovlsiz[1], offstr[2]); | |
cc8bea0a MS |
1634 | return true; |
1635 | } | |
1636 | ||
1637 | if (sizrange[1] >= 0 && sizrange[1] < maxobjsize.to_shwi ()) | |
1638 | { | |
1639 | if (open_range) | |
15d3974b JJ |
1640 | warning_n (loc, OPT_Wrestrict, ovlsiz[1], |
1641 | "%G%qD accessing between %wu and %wu bytes " | |
1642 | "may overlap %wu byte", | |
1643 | "%G%qD accessing between %wu and %wu bytes " | |
1644 | "may overlap up to %wu bytes", | |
1645 | call, func, sizrange[0], sizrange[1], ovlsiz[1]); | |
cc8bea0a | 1646 | else |
15d3974b JJ |
1647 | warning_n (loc, OPT_Wrestrict, ovlsiz[1], |
1648 | "%G%qD accessing between %wu and %wu bytes " | |
1649 | "at offsets %s and %s may overlap %wu byte " | |
1650 | "at offset %s", | |
1651 | "%G%qD accessing between %wu and %wu bytes " | |
1652 | "at offsets %s and %s may overlap up to %wu " | |
1653 | "bytes at offset %s", | |
1654 | call, func, sizrange[0], sizrange[1], | |
1655 | offstr[0], offstr[1], ovlsiz[1], offstr[2]); | |
cc8bea0a MS |
1656 | return true; |
1657 | } | |
1658 | ||
15d3974b JJ |
1659 | warning_n (loc, OPT_Wrestrict, ovlsiz[1], |
1660 | "%G%qD accessing %wu or more bytes at offsets %s " | |
1661 | "and %s may overlap %wu byte at offset %s", | |
1662 | "%G%qD accessing %wu or more bytes at offsets %s " | |
1663 | "and %s may overlap up to %wu bytes at offset %s", | |
1664 | call, func, sizrange[0], offstr[0], offstr[1], | |
1665 | ovlsiz[1], offstr[2]); | |
cc8bea0a MS |
1666 | |
1667 | return true; | |
1668 | } | |
1669 | ||
287ef129 MS |
1670 | /* Validate REF size and offsets in an expression passed as an argument |
1671 | to a CALL to a built-in function FUNC to make sure they are within | |
1672 | the bounds of the referenced object if its size is known, or | |
1673 | PTRDIFF_MAX otherwise. DO_WARN is true when a diagnostic should | |
1674 | be issued, false otherwise. | |
1675 | Both initial values of the offsets and their final value computed | |
1676 | by the function by incrementing the initial value by the size are | |
cc8bea0a | 1677 | validated. Return true if the offsets are not valid and a diagnostic |
287ef129 | 1678 | has been issued, or would have been issued if DO_WARN had been true. */ |
cc8bea0a MS |
1679 | |
1680 | static bool | |
55ace4d1 | 1681 | maybe_diag_access_bounds (gimple *call, tree func, int strict, |
6889a3ac MS |
1682 | const builtin_memref &ref, offset_int wroff, |
1683 | bool do_warn) | |
cc8bea0a | 1684 | { |
55ace4d1 | 1685 | location_t loc = gimple_or_expr_nonartificial_location (call, ref.ptr); |
a411ae9b | 1686 | const offset_int maxobjsize = ref.maxobjsize; |
287ef129 MS |
1687 | |
1688 | /* Check for excessive size first and regardless of warning options | |
1689 | since the result is used to make codegen decisions. */ | |
1690 | if (ref.sizrange[0] > maxobjsize) | |
1691 | { | |
1692 | /* Return true without issuing a warning. */ | |
1693 | if (!do_warn) | |
1694 | return true; | |
1695 | ||
1696 | if (ref.ref && TREE_NO_WARNING (ref.ref)) | |
1697 | return false; | |
1698 | ||
1699 | if (warn_stringop_overflow) | |
1700 | { | |
287ef129 MS |
1701 | if (ref.sizrange[0] == ref.sizrange[1]) |
1702 | return warning_at (loc, OPT_Wstringop_overflow_, | |
1703 | "%G%qD specified bound %wu " | |
1704 | "exceeds maximum object size %wu", | |
1705 | call, func, ref.sizrange[0].to_uhwi (), | |
1706 | maxobjsize.to_uhwi ()); | |
1707 | ||
1708 | return warning_at (loc, OPT_Wstringop_overflow_, | |
1709 | "%G%qD specified bound between %wu and %wu " | |
1710 | "exceeds maximum object size %wu", | |
1711 | call, func, ref.sizrange[0].to_uhwi (), | |
1712 | ref.sizrange[1].to_uhwi (), | |
1713 | maxobjsize.to_uhwi ()); | |
1714 | } | |
1715 | } | |
1716 | ||
213694e5 | 1717 | /* Check for out-bounds pointers regardless of warning options since |
6889a3ac MS |
1718 | the result is used to make codegen decisions. An excessive WROFF |
1719 | can only come up as a result of an invalid strncat bound and is | |
1720 | diagnosed separately using a more meaningful warning. */ | |
1721 | if (maxobjsize < wroff) | |
1722 | wroff = 0; | |
1723 | offset_int ooboff[] = { ref.offrange[0], ref.offrange[1], wroff }; | |
213694e5 MS |
1724 | tree oobref = ref.offset_out_of_bounds (strict, ooboff); |
1725 | if (!oobref) | |
cc8bea0a MS |
1726 | return false; |
1727 | ||
213694e5 MS |
1728 | /* Return true without issuing a warning. */ |
1729 | if (!do_warn) | |
1730 | return true; | |
1731 | ||
1732 | if (!warn_array_bounds) | |
21150aba JJ |
1733 | return false; |
1734 | ||
14b7950f MS |
1735 | if (TREE_NO_WARNING (ref.ptr) |
1736 | || (ref.ref && TREE_NO_WARNING (ref.ref))) | |
cc8bea0a MS |
1737 | return false; |
1738 | ||
cc8bea0a MS |
1739 | char rangestr[2][64]; |
1740 | if (ooboff[0] == ooboff[1] | |
1741 | || (ooboff[0] != ref.offrange[0] | |
1742 | && ooboff[0].to_shwi () >= ooboff[1].to_shwi ())) | |
1743 | sprintf (rangestr[0], "%lli", (long long) ooboff[0].to_shwi ()); | |
1744 | else | |
1745 | sprintf (rangestr[0], "[%lli, %lli]", | |
1746 | (long long) ooboff[0].to_shwi (), | |
1747 | (long long) ooboff[1].to_shwi ()); | |
1748 | ||
e3329a78 MS |
1749 | bool warned = false; |
1750 | ||
cc8bea0a MS |
1751 | if (oobref == error_mark_node) |
1752 | { | |
1753 | if (ref.sizrange[0] == ref.sizrange[1]) | |
287ef129 MS |
1754 | sprintf (rangestr[1], "%llu", |
1755 | (unsigned long long) ref.sizrange[0].to_shwi ()); | |
cc8bea0a MS |
1756 | else |
1757 | sprintf (rangestr[1], "[%lli, %lli]", | |
287ef129 MS |
1758 | (unsigned long long) ref.sizrange[0].to_uhwi (), |
1759 | (unsigned long long) ref.sizrange[1].to_uhwi ()); | |
cc8bea0a | 1760 | |
e3329a78 MS |
1761 | tree type; |
1762 | ||
cc8bea0a MS |
1763 | if (DECL_P (ref.base) |
1764 | && TREE_CODE (type = TREE_TYPE (ref.base)) == ARRAY_TYPE) | |
1765 | { | |
097f82ec | 1766 | auto_diagnostic_group d; |
cc8bea0a MS |
1767 | if (warning_at (loc, OPT_Warray_bounds, |
1768 | "%G%qD pointer overflow between offset %s " | |
1769 | "and size %s accessing array %qD with type %qT", | |
1770 | call, func, rangestr[0], rangestr[1], ref.base, type)) | |
e3329a78 MS |
1771 | { |
1772 | inform (DECL_SOURCE_LOCATION (ref.base), | |
1773 | "array %qD declared here", ref.base); | |
1774 | warned = true; | |
1775 | } | |
cc8bea0a | 1776 | else |
e3329a78 MS |
1777 | warned = warning_at (loc, OPT_Warray_bounds, |
1778 | "%G%qD pointer overflow between offset %s " | |
1779 | "and size %s", | |
1780 | call, func, rangestr[0], rangestr[1]); | |
cc8bea0a MS |
1781 | } |
1782 | else | |
e3329a78 MS |
1783 | warned = warning_at (loc, OPT_Warray_bounds, |
1784 | "%G%qD pointer overflow between offset %s " | |
1785 | "and size %s", | |
1786 | call, func, rangestr[0], rangestr[1]); | |
cc8bea0a MS |
1787 | } |
1788 | else if (oobref == ref.base) | |
1789 | { | |
cc8bea0a MS |
1790 | /* True when the offset formed by an access to the reference |
1791 | is out of bounds, rather than the initial offset wich is | |
1792 | in bounds. This implies access past the end. */ | |
1793 | bool form = ooboff[0] != ref.offrange[0]; | |
1794 | ||
1795 | if (DECL_P (ref.base)) | |
1796 | { | |
097f82ec | 1797 | auto_diagnostic_group d; |
cc8bea0a MS |
1798 | if ((ref.basesize < maxobjsize |
1799 | && warning_at (loc, OPT_Warray_bounds, | |
1800 | form | |
1801 | ? G_("%G%qD forming offset %s is out of " | |
1802 | "the bounds [0, %wu] of object %qD with " | |
1803 | "type %qT") | |
1804 | : G_("%G%qD offset %s is out of the bounds " | |
1805 | "[0, %wu] of object %qD with type %qT"), | |
1806 | call, func, rangestr[0], ref.basesize.to_uhwi (), | |
1807 | ref.base, TREE_TYPE (ref.base))) | |
1808 | || warning_at (loc, OPT_Warray_bounds, | |
1809 | form | |
1810 | ? G_("%G%qD forming offset %s is out of " | |
1811 | "the bounds of object %qD with type %qT") | |
1812 | : G_("%G%qD offset %s is out of the bounds " | |
1813 | "of object %qD with type %qT"), | |
1814 | call, func, rangestr[0], | |
1815 | ref.base, TREE_TYPE (ref.base))) | |
e3329a78 MS |
1816 | { |
1817 | inform (DECL_SOURCE_LOCATION (ref.base), | |
1818 | "%qD declared here", ref.base); | |
1819 | warned = true; | |
1820 | } | |
cc8bea0a MS |
1821 | } |
1822 | else if (ref.basesize < maxobjsize) | |
e3329a78 MS |
1823 | warned = warning_at (loc, OPT_Warray_bounds, |
1824 | form | |
1825 | ? G_("%G%qD forming offset %s is out " | |
1826 | "of the bounds [0, %wu]") | |
1827 | : G_("%G%qD offset %s is out " | |
1828 | "of the bounds [0, %wu]"), | |
1829 | call, func, rangestr[0], ref.basesize.to_uhwi ()); | |
cc8bea0a | 1830 | else |
e3329a78 MS |
1831 | warned = warning_at (loc, OPT_Warray_bounds, |
1832 | form | |
1833 | ? G_("%G%qD forming offset %s is out of bounds") | |
1834 | : G_("%G%qD offset %s is out of bounds"), | |
1835 | call, func, rangestr[0]); | |
cc8bea0a MS |
1836 | } |
1837 | else if (TREE_CODE (ref.ref) == MEM_REF) | |
1838 | { | |
6889a3ac MS |
1839 | tree refop = TREE_OPERAND (ref.ref, 0); |
1840 | tree type = TREE_TYPE (refop); | |
cc8bea0a MS |
1841 | if (POINTER_TYPE_P (type)) |
1842 | type = TREE_TYPE (type); | |
1843 | type = TYPE_MAIN_VARIANT (type); | |
1844 | ||
6889a3ac MS |
1845 | if (warning_at (loc, OPT_Warray_bounds, |
1846 | "%G%qD offset %s from the object at %qE is out " | |
1847 | "of the bounds of %qT", | |
1848 | call, func, rangestr[0], ref.base, type)) | |
1849 | { | |
1850 | if (TREE_CODE (ref.ref) == COMPONENT_REF) | |
1851 | refop = TREE_OPERAND (ref.ref, 1); | |
1852 | if (DECL_P (refop)) | |
1853 | inform (DECL_SOURCE_LOCATION (refop), | |
1854 | "subobject %qD declared here", refop); | |
1855 | warned = true; | |
1856 | } | |
cc8bea0a MS |
1857 | } |
1858 | else | |
1859 | { | |
6889a3ac | 1860 | tree refop = TREE_OPERAND (ref.ref, 0); |
e3329a78 MS |
1861 | tree type = TYPE_MAIN_VARIANT (TREE_TYPE (ref.ref)); |
1862 | ||
6889a3ac MS |
1863 | if (warning_at (loc, OPT_Warray_bounds, |
1864 | "%G%qD offset %s from the object at %qE is out " | |
1865 | "of the bounds of referenced subobject %qD with " | |
1866 | "type %qT at offset %wi", | |
1867 | call, func, rangestr[0], ref.base, | |
1868 | TREE_OPERAND (ref.ref, 1), type, | |
1869 | ref.refoff.to_shwi ())) | |
1870 | { | |
1871 | if (TREE_CODE (ref.ref) == COMPONENT_REF) | |
1872 | refop = TREE_OPERAND (ref.ref, 1); | |
1873 | if (DECL_P (refop)) | |
1874 | inform (DECL_SOURCE_LOCATION (refop), | |
1875 | "subobject %qD declared here", refop); | |
1876 | warned = true; | |
1877 | } | |
cc8bea0a MS |
1878 | } |
1879 | ||
e3329a78 | 1880 | return warned; |
cc8bea0a MS |
1881 | } |
1882 | ||
1883 | /* Check a CALL statement for restrict-violations and issue warnings | |
1884 | if/when appropriate. */ | |
1885 | ||
e864d395 AH |
1886 | static void |
1887 | check_call (range_query *query, gimple *call) | |
cc8bea0a MS |
1888 | { |
1889 | /* Avoid checking the call if it has already been diagnosed for | |
1890 | some reason. */ | |
1891 | if (gimple_no_warning_p (call)) | |
1892 | return; | |
1893 | ||
1894 | tree func = gimple_call_fndecl (call); | |
3d78e008 | 1895 | if (!func || !fndecl_built_in_p (func, BUILT_IN_NORMAL)) |
cc8bea0a MS |
1896 | return; |
1897 | ||
cc8bea0a MS |
1898 | /* Argument number to extract from the call (depends on the built-in |
1899 | and its kind). */ | |
1900 | unsigned dst_idx = -1; | |
1901 | unsigned src_idx = -1; | |
1902 | unsigned bnd_idx = -1; | |
1903 | ||
1904 | /* Is this CALL to a string function (as opposed to one to a raw | |
1905 | memory function). */ | |
1906 | bool strfun = true; | |
1907 | ||
1908 | switch (DECL_FUNCTION_CODE (func)) | |
1909 | { | |
1910 | case BUILT_IN_MEMCPY: | |
1911 | case BUILT_IN_MEMCPY_CHK: | |
cc8bea0a MS |
1912 | case BUILT_IN_MEMPCPY: |
1913 | case BUILT_IN_MEMPCPY_CHK: | |
cc8bea0a MS |
1914 | case BUILT_IN_MEMMOVE: |
1915 | case BUILT_IN_MEMMOVE_CHK: | |
cc8bea0a MS |
1916 | strfun = false; |
1917 | /* Fall through. */ | |
1918 | ||
1919 | case BUILT_IN_STPNCPY: | |
1920 | case BUILT_IN_STPNCPY_CHK: | |
1921 | case BUILT_IN_STRNCAT: | |
1922 | case BUILT_IN_STRNCAT_CHK: | |
1923 | case BUILT_IN_STRNCPY: | |
1924 | case BUILT_IN_STRNCPY_CHK: | |
1925 | dst_idx = 0; | |
31db0fe0 ML |
1926 | src_idx = 1; |
1927 | bnd_idx = 2; | |
cc8bea0a MS |
1928 | break; |
1929 | ||
a411ae9b MS |
1930 | case BUILT_IN_MEMSET: |
1931 | case BUILT_IN_MEMSET_CHK: | |
1932 | dst_idx = 0; | |
1933 | bnd_idx = 2; | |
1934 | break; | |
1935 | ||
cc8bea0a MS |
1936 | case BUILT_IN_STPCPY: |
1937 | case BUILT_IN_STPCPY_CHK: | |
cc8bea0a MS |
1938 | case BUILT_IN_STRCPY: |
1939 | case BUILT_IN_STRCPY_CHK: | |
cc8bea0a MS |
1940 | case BUILT_IN_STRCAT: |
1941 | case BUILT_IN_STRCAT_CHK: | |
cc8bea0a | 1942 | dst_idx = 0; |
31db0fe0 | 1943 | src_idx = 1; |
cc8bea0a MS |
1944 | break; |
1945 | ||
1946 | default: | |
1947 | /* Handle other string functions here whose access may need | |
1948 | to be validated for in-bounds offsets and non-overlapping | |
31db0fe0 | 1949 | copies. */ |
cc8bea0a MS |
1950 | return; |
1951 | } | |
1952 | ||
1953 | unsigned nargs = gimple_call_num_args (call); | |
1954 | ||
1955 | tree dst = dst_idx < nargs ? gimple_call_arg (call, dst_idx) : NULL_TREE; | |
1956 | tree src = src_idx < nargs ? gimple_call_arg (call, src_idx) : NULL_TREE; | |
1957 | tree dstwr = bnd_idx < nargs ? gimple_call_arg (call, bnd_idx) : NULL_TREE; | |
1958 | ||
1959 | /* For string functions with an unspecified or unknown bound, | |
1960 | assume the size of the access is one. */ | |
1961 | if (!dstwr && strfun) | |
1962 | dstwr = size_one_node; | |
1963 | ||
2438cb6a MS |
1964 | /* DST and SRC can be null for a call with an insufficient number |
1965 | of arguments to a built-in function declared without a protype. */ | |
a411ae9b | 1966 | if (!dst || (src_idx < nargs && !src)) |
cf3fc0e8 MS |
1967 | return; |
1968 | ||
1969 | /* DST, SRC, or DSTWR can also have the wrong type in a call to | |
1970 | a function declared without a prototype. Avoid checking such | |
1971 | invalid calls. */ | |
1972 | if (TREE_CODE (TREE_TYPE (dst)) != POINTER_TYPE | |
a411ae9b | 1973 | || (src && TREE_CODE (TREE_TYPE (src)) != POINTER_TYPE) |
cf3fc0e8 MS |
1974 | || (dstwr && !INTEGRAL_TYPE_P (TREE_TYPE (dstwr)))) |
1975 | return; | |
1976 | ||
e864d395 | 1977 | if (!check_bounds_or_overlap (query, call, dst, src, dstwr, NULL_TREE)) |
cc8bea0a MS |
1978 | return; |
1979 | ||
1980 | /* Avoid diagnosing the call again. */ | |
1981 | gimple_set_no_warning (call, true); | |
1982 | } | |
1983 | ||
1984 | } /* anonymous namespace */ | |
1985 | ||
1986 | /* Attempt to detect and diagnose invalid offset bounds and (except for | |
1987 | memmove) overlapping copy in a call expression EXPR from SRC to DST | |
1988 | and DSTSIZE and SRCSIZE bytes, respectively. Both DSTSIZE and | |
213694e5 MS |
1989 | SRCSIZE may be NULL. DO_WARN is false to detect either problem |
1990 | without issue a warning. Return the OPT_Wxxx constant corresponding | |
1991 | to the warning if one has been detected and zero otherwise. */ | |
cc8bea0a | 1992 | |
213694e5 | 1993 | int |
8a45b051 | 1994 | check_bounds_or_overlap (gimple *call, tree dst, tree src, tree dstsize, |
213694e5 MS |
1995 | tree srcsize, bool bounds_only /* = false */, |
1996 | bool do_warn /* = true */) | |
e864d395 AH |
1997 | { |
1998 | return check_bounds_or_overlap (/*range_query=*/NULL, | |
1999 | call, dst, src, dstsize, srcsize, | |
2000 | bounds_only, do_warn); | |
2001 | } | |
2002 | ||
2003 | int | |
2004 | check_bounds_or_overlap (range_query *query, | |
2005 | gimple *call, tree dst, tree src, tree dstsize, | |
2006 | tree srcsize, bool bounds_only /* = false */, | |
2007 | bool do_warn /* = true */) | |
cc8bea0a | 2008 | { |
cc8bea0a MS |
2009 | tree func = gimple_call_fndecl (call); |
2010 | ||
e864d395 AH |
2011 | builtin_memref dstref (query, call, dst, dstsize); |
2012 | builtin_memref srcref (query, call, src, srcsize); | |
cc8bea0a | 2013 | |
6889a3ac MS |
2014 | /* Create a descriptor of the access. This may adjust both DSTREF |
2015 | and SRCREF based on one another and the kind of the access. */ | |
e864d395 | 2016 | builtin_access acs (query, call, dstref, srcref); |
cc8bea0a MS |
2017 | |
2018 | /* Set STRICT to the value of the -Warray-bounds=N argument for | |
2019 | string functions or when N > 1. */ | |
2020 | int strict = (acs.strict () || warn_array_bounds > 1 ? warn_array_bounds : 0); | |
2021 | ||
6889a3ac MS |
2022 | /* The starting offset of the destination write access. Nonzero only |
2023 | for the strcat family of functions. */ | |
2024 | offset_int wroff = acs.write_off (dstsize); | |
2025 | ||
2026 | /* Validate offsets to each reference before the access first to make | |
2027 | sure they are within the bounds of the destination object if its | |
2028 | size is known, or PTRDIFF_MAX otherwise. */ | |
55ace4d1 JL |
2029 | if (maybe_diag_access_bounds (call, func, strict, dstref, wroff, do_warn) |
2030 | || maybe_diag_access_bounds (call, func, strict, srcref, 0, do_warn)) | |
cc8bea0a | 2031 | { |
213694e5 MS |
2032 | if (do_warn) |
2033 | gimple_set_no_warning (call, true); | |
2034 | return OPT_Warray_bounds; | |
cc8bea0a MS |
2035 | } |
2036 | ||
a411ae9b | 2037 | if (!warn_restrict || bounds_only || !src) |
213694e5 | 2038 | return 0; |
cc8bea0a | 2039 | |
a411ae9b MS |
2040 | if (!bounds_only) |
2041 | { | |
2042 | switch (DECL_FUNCTION_CODE (func)) | |
2043 | { | |
2044 | case BUILT_IN_MEMMOVE: | |
2045 | case BUILT_IN_MEMMOVE_CHK: | |
2046 | case BUILT_IN_MEMSET: | |
2047 | case BUILT_IN_MEMSET_CHK: | |
2048 | return 0; | |
2049 | default: | |
2050 | break; | |
2051 | } | |
2052 | } | |
2053 | ||
55ace4d1 | 2054 | location_t loc = gimple_or_expr_nonartificial_location (call, dst); |
cc8bea0a MS |
2055 | if (operand_equal_p (dst, src, 0)) |
2056 | { | |
8cd95cec MS |
2057 | /* Issue -Wrestrict unless the pointers are null (those do |
2058 | not point to objects and so do not indicate an overlap; | |
2059 | such calls could be the result of sanitization and jump | |
2060 | threading). */ | |
2061 | if (!integer_zerop (dst) && !gimple_no_warning_p (call)) | |
2062 | { | |
2063 | warning_at (loc, OPT_Wrestrict, | |
2064 | "%G%qD source argument is the same as destination", | |
2065 | call, func); | |
2066 | gimple_set_no_warning (call, true); | |
213694e5 | 2067 | return OPT_Wrestrict; |
8cd95cec MS |
2068 | } |
2069 | ||
213694e5 | 2070 | return 0; |
cc8bea0a MS |
2071 | } |
2072 | ||
2073 | /* Return false when overlap has been detected. */ | |
2074 | if (maybe_diag_overlap (loc, call, acs)) | |
2075 | { | |
2076 | gimple_set_no_warning (call, true); | |
213694e5 | 2077 | return OPT_Wrestrict; |
cc8bea0a MS |
2078 | } |
2079 | ||
213694e5 | 2080 | return 0; |
cc8bea0a MS |
2081 | } |
2082 | ||
2083 | gimple_opt_pass * | |
2084 | make_pass_warn_restrict (gcc::context *ctxt) | |
2085 | { | |
2086 | return new pass_wrestrict (ctxt); | |
2087 | } | |
6889a3ac MS |
2088 | |
2089 | DEBUG_FUNCTION void | |
2090 | dump_builtin_memref (FILE *fp, const builtin_memref &ref) | |
2091 | { | |
2092 | fprintf (fp, "\n ptr = "); | |
2093 | print_generic_expr (fp, ref.ptr, TDF_LINENO); | |
2094 | fprintf (fp, "\n ref = "); | |
2095 | if (ref.ref) | |
2096 | print_generic_expr (fp, ref.ref, TDF_LINENO); | |
2097 | else | |
2098 | fputs ("null", fp); | |
2099 | fprintf (fp, "\n base = "); | |
2100 | print_generic_expr (fp, ref.base, TDF_LINENO); | |
2101 | fprintf (fp, | |
2102 | "\n basesize = %lli" | |
2103 | "\n refsize = %lli" | |
2104 | "\n refoff = %lli" | |
2105 | "\n offrange = [%lli, %lli]" | |
2106 | "\n sizrange = [%lli, %lli]" | |
2107 | "\n strbounded_p = %s\n", | |
2108 | (long long)ref.basesize.to_shwi (), | |
2109 | (long long)ref.refsize.to_shwi (), | |
2110 | (long long)ref.refoff.to_shwi (), | |
2111 | (long long)ref.offrange[0].to_shwi (), | |
2112 | (long long)ref.offrange[1].to_shwi (), | |
2113 | (long long)ref.sizrange[0].to_shwi (), | |
2114 | (long long)ref.sizrange[1].to_shwi (), | |
2115 | ref.strbounded_p ? "true" : "false"); | |
2116 | } | |
2117 | ||
2118 | void | |
2119 | builtin_access::dump (FILE *fp) const | |
2120 | { | |
2121 | fprintf (fp, " dstref:"); | |
2122 | dump_builtin_memref (fp, *dstref); | |
2123 | fprintf (fp, "\n srcref:"); | |
2124 | dump_builtin_memref (fp, *srcref); | |
2125 | ||
2126 | fprintf (fp, | |
2127 | " sizrange = [%lli, %lli]\n" | |
2128 | " ovloff = [%lli, %lli]\n" | |
2129 | " ovlsiz = [%lli, %lli]\n" | |
2130 | " dstoff = [%lli, %lli]\n" | |
2131 | " dstsiz = [%lli, %lli]\n" | |
2132 | " srcoff = [%lli, %lli]\n" | |
2133 | " srcsiz = [%lli, %lli]\n", | |
2134 | (long long)sizrange[0], (long long)sizrange[1], | |
2135 | (long long)ovloff[0], (long long)ovloff[1], | |
2136 | (long long)ovlsiz[0], (long long)ovlsiz[1], | |
2137 | (long long)dstoff[0].to_shwi (), (long long)dstoff[1].to_shwi (), | |
2138 | (long long)dstsiz[0].to_shwi (), (long long)dstsiz[1].to_shwi (), | |
2139 | (long long)srcoff[0].to_shwi (), (long long)srcoff[1].to_shwi (), | |
2140 | (long long)srcsiz[0].to_shwi (), (long long)srcsiz[1].to_shwi ()); | |
2141 | } | |
2142 | ||
2143 | DEBUG_FUNCTION void | |
2144 | dump_builtin_access (FILE *fp, gimple *stmt, const builtin_access &acs) | |
2145 | { | |
2146 | if (stmt) | |
2147 | { | |
2148 | fprintf (fp, "\nDumping builtin_access for "); | |
2149 | print_gimple_expr (fp, stmt, TDF_LINENO); | |
2150 | fputs (":\n", fp); | |
2151 | } | |
2152 | ||
2153 | acs.dump (fp); | |
2154 | } | |
2155 | ||
2156 | DEBUG_FUNCTION void | |
2157 | debug (gimple *stmt, const builtin_access &acs) | |
2158 | { | |
2159 | dump_builtin_access (stdout, stmt, acs); | |
2160 | } |