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cc8bea0a MS |
1 | /* Pass to detect and issue warnings for violations of the restrict |
2 | qualifier. | |
7adcbafe | 3 | Copyright (C) 2017-2022 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 | 28 | #include "tree-pass.h" |
2a837de2 | 29 | #include "pointer-query.h" |
cc8bea0a MS |
30 | #include "ssa.h" |
31 | #include "gimple-pretty-print.h" | |
b48d4e68 | 32 | #include "gimple-ssa-warn-access.h" |
cc8bea0a MS |
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" | |
cc8bea0a MS |
39 | #include "tree-cfg.h" |
40 | #include "tree-object-size.h" | |
41 | #include "calls.h" | |
42 | #include "cfgloop.h" | |
43 | #include "intl.h" | |
e864d395 | 44 | #include "gimple-range.h" |
cc8bea0a MS |
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: | |
30d15b51 | 65 | pass_wrestrict (gcc::context *); |
cc8bea0a | 66 | |
725793af DM |
67 | bool gate (function *) final override; |
68 | unsigned int execute (function *) final override; | |
30d15b51 MS |
69 | |
70 | void check_call (gimple *); | |
71 | ||
72 | void check_block (basic_block); | |
73 | ||
74 | /* A pointer_query object to store information about pointers and | |
75 | their targets in. */ | |
76 | pointer_query m_ptr_qry; | |
cc8bea0a MS |
77 | }; |
78 | ||
30d15b51 MS |
79 | pass_wrestrict::pass_wrestrict (gcc::context *ctxt) |
80 | : gimple_opt_pass (pass_data_wrestrict, ctxt), | |
81 | m_ptr_qry () | |
82 | { } | |
83 | ||
cc8bea0a MS |
84 | bool |
85 | pass_wrestrict::gate (function *fun ATTRIBUTE_UNUSED) | |
86 | { | |
287ef129 | 87 | return warn_array_bounds || warn_restrict || warn_stringop_overflow; |
cc8bea0a MS |
88 | } |
89 | ||
30d15b51 MS |
90 | void |
91 | pass_wrestrict::check_block (basic_block bb) | |
cc8bea0a MS |
92 | { |
93 | /* Iterate over statements, looking for function calls. */ | |
30d15b51 | 94 | for (auto si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si)) |
cc8bea0a MS |
95 | { |
96 | gimple *stmt = gsi_stmt (si); | |
97 | if (!is_gimple_call (stmt)) | |
98 | continue; | |
99 | ||
30d15b51 | 100 | check_call (stmt); |
cc8bea0a | 101 | } |
cc8bea0a MS |
102 | } |
103 | ||
cc8bea0a MS |
104 | unsigned |
105 | pass_wrestrict::execute (function *fun) | |
106 | { | |
30d15b51 MS |
107 | /* Create a new ranger instance and associate it with FUN. */ |
108 | m_ptr_qry.rvals = enable_ranger (fun); | |
109 | ||
e864d395 AH |
110 | basic_block bb; |
111 | FOR_EACH_BB_FN (bb, fun) | |
30d15b51 MS |
112 | check_block (bb); |
113 | ||
114 | m_ptr_qry.flush_cache (); | |
115 | ||
116 | /* Release the ranger instance and replace it with a global ranger. | |
117 | Also reset the pointer since calling disable_ranger() deletes it. */ | |
118 | disable_ranger (fun); | |
119 | m_ptr_qry.rvals = NULL; | |
cc8bea0a MS |
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; | |
6889a3ac MS |
140 | /* Same for the subobject. */ |
141 | offset_int refsize; | |
cc8bea0a MS |
142 | |
143 | /* The non-negative offset of the referenced subobject. Used to avoid | |
144 | warnings for (apparently) possibly but not definitively overlapping | |
145 | accesses to member arrays. Negative when unknown/invalid. */ | |
146 | offset_int refoff; | |
147 | ||
148 | /* The offset range relative to the base. */ | |
149 | offset_int offrange[2]; | |
150 | /* The size range of the access to this reference. */ | |
151 | offset_int sizrange[2]; | |
152 | ||
a411ae9b MS |
153 | /* Cached result of get_max_objsize(). */ |
154 | const offset_int maxobjsize; | |
155 | ||
cc8bea0a MS |
156 | /* True for "bounded" string functions like strncat, and strncpy |
157 | and their variants that specify either an exact or upper bound | |
158 | on the size of the accesses they perform. For strncat both | |
159 | the source and destination references are bounded. For strncpy | |
160 | only the destination reference is. */ | |
161 | bool strbounded_p; | |
162 | ||
30d15b51 | 163 | builtin_memref (pointer_query &, gimple *, tree, tree); |
cc8bea0a | 164 | |
6889a3ac | 165 | tree offset_out_of_bounds (int, offset_int[3]) const; |
5e27f0d5 MS |
166 | |
167 | private: | |
e864d395 AH |
168 | /* Call statement to the built-in. */ |
169 | gimple *stmt; | |
170 | ||
30d15b51 | 171 | pointer_query &m_ptr_qry; |
5e27f0d5 MS |
172 | |
173 | /* Ctor helper to set or extend OFFRANGE based on argument. */ | |
174 | void extend_offset_range (tree); | |
175 | ||
176 | /* Ctor helper to determine BASE and OFFRANGE from argument. */ | |
177 | void set_base_and_offset (tree); | |
cc8bea0a MS |
178 | }; |
179 | ||
180 | /* Description of a memory access by a raw memory or string built-in | |
181 | function involving a pair of builtin_memref's. */ | |
182 | class builtin_access | |
183 | { | |
184 | public: | |
185 | /* Destination and source memory reference. */ | |
186 | builtin_memref* const dstref; | |
187 | builtin_memref* const srcref; | |
188 | /* The size range of the access. It's the greater of the accesses | |
189 | to the two references. */ | |
190 | HOST_WIDE_INT sizrange[2]; | |
191 | ||
192 | /* The minimum and maximum offset of an overlap of the access | |
193 | (if it does, in fact, overlap), and the size of the overlap. */ | |
194 | HOST_WIDE_INT ovloff[2]; | |
195 | HOST_WIDE_INT ovlsiz[2]; | |
196 | ||
197 | /* True to consider valid only accesses to the smallest subobject | |
198 | and false for raw memory functions. */ | |
199 | bool strict () const | |
200 | { | |
6889a3ac MS |
201 | return (detect_overlap != &builtin_access::generic_overlap |
202 | && detect_overlap != &builtin_access::no_overlap); | |
cc8bea0a MS |
203 | } |
204 | ||
30d15b51 MS |
205 | builtin_access (pointer_query &, gimple *, |
206 | builtin_memref &, builtin_memref &); | |
cc8bea0a MS |
207 | |
208 | /* Entry point to determine overlap. */ | |
209 | bool overlap (); | |
210 | ||
6889a3ac MS |
211 | offset_int write_off (tree) const; |
212 | ||
213 | void dump (FILE *) const; | |
214 | ||
cc8bea0a MS |
215 | private: |
216 | /* Implementation functions used to determine overlap. */ | |
217 | bool generic_overlap (); | |
218 | bool strcat_overlap (); | |
219 | bool strcpy_overlap (); | |
220 | ||
221 | bool no_overlap () | |
222 | { | |
223 | return false; | |
224 | } | |
225 | ||
226 | offset_int overlap_size (const offset_int [2], const offset_int[2], | |
227 | offset_int [2]); | |
228 | ||
229 | private: | |
230 | /* Temporaries used to compute the final result. */ | |
231 | offset_int dstoff[2]; | |
232 | offset_int srcoff[2]; | |
233 | offset_int dstsiz[2]; | |
234 | offset_int srcsiz[2]; | |
235 | ||
236 | /* Pointer to a member function to call to determine overlap. */ | |
237 | bool (builtin_access::*detect_overlap) (); | |
238 | }; | |
239 | ||
240 | /* Initialize a memory reference representation from a pointer EXPR and | |
241 | a size SIZE in bytes. If SIZE is NULL_TREE then the size is assumed | |
e864d395 | 242 | to be unknown. STMT is the statement in which expr appears in. */ |
cc8bea0a | 243 | |
30d15b51 | 244 | builtin_memref::builtin_memref (pointer_query &ptrqry, gimple *stmt, tree expr, |
e864d395 | 245 | tree size) |
cc8bea0a MS |
246 | : ptr (expr), |
247 | ref (), | |
248 | base (), | |
249 | basesize (-1), | |
6889a3ac | 250 | refsize (-1), |
cc8bea0a MS |
251 | refoff (HOST_WIDE_INT_MIN), |
252 | offrange (), | |
253 | sizrange (), | |
a411ae9b | 254 | maxobjsize (tree_to_shwi (max_object_size ())), |
e864d395 AH |
255 | strbounded_p (), |
256 | stmt (stmt), | |
30d15b51 | 257 | m_ptr_qry (ptrqry) |
cc8bea0a MS |
258 | { |
259 | /* Unfortunately, wide_int default ctor is a no-op so array members | |
260 | of the type must be set individually. */ | |
261 | offrange[0] = offrange[1] = 0; | |
262 | sizrange[0] = sizrange[1] = 0; | |
263 | ||
a411ae9b MS |
264 | if (!expr) |
265 | return; | |
cc8bea0a | 266 | |
5e27f0d5 MS |
267 | /* Find the BASE object or pointer referenced by EXPR and set |
268 | the offset range OFFRANGE in the process. */ | |
269 | set_base_and_offset (expr); | |
270 | ||
271 | if (size) | |
272 | { | |
273 | tree range[2]; | |
274 | /* Determine the size range, allowing for the result to be [0, 0] | |
275 | for SIZE in the anti-range ~[0, N] where N >= PTRDIFF_MAX. */ | |
30d15b51 | 276 | get_size_range (m_ptr_qry.rvals, size, stmt, range, SR_ALLOW_ZERO); |
5e27f0d5 MS |
277 | sizrange[0] = wi::to_offset (range[0]); |
278 | sizrange[1] = wi::to_offset (range[1]); | |
279 | /* get_size_range returns SIZE_MAX for the maximum size. | |
280 | Constrain it to the real maximum of PTRDIFF_MAX. */ | |
287ef129 | 281 | if (sizrange[0] <= maxobjsize && sizrange[1] > maxobjsize) |
5e27f0d5 MS |
282 | sizrange[1] = maxobjsize; |
283 | } | |
284 | else | |
285 | sizrange[1] = maxobjsize; | |
286 | ||
7ad491c6 MS |
287 | if (!DECL_P (base)) |
288 | return; | |
289 | ||
290 | /* If the offset could be in the range of the referenced object | |
291 | constrain its bounds so neither exceeds those of the object. */ | |
292 | if (offrange[0] < 0 && offrange[1] > 0) | |
293 | offrange[0] = 0; | |
294 | ||
295 | offset_int maxoff = maxobjsize; | |
5e27f0d5 | 296 | tree basetype = TREE_TYPE (base); |
1486eb79 MS |
297 | if (TREE_CODE (basetype) == ARRAY_TYPE) |
298 | { | |
299 | if (ref && array_at_struct_end_p (ref)) | |
300 | ; /* Use the maximum possible offset for last member arrays. */ | |
301 | else if (tree basesize = TYPE_SIZE_UNIT (basetype)) | |
302 | if (TREE_CODE (basesize) == INTEGER_CST) | |
303 | /* Size could be non-constant for a variable-length type such | |
304 | as a struct with a VLA member (a GCC extension). */ | |
305 | maxoff = wi::to_offset (basesize); | |
306 | } | |
7ad491c6 MS |
307 | |
308 | if (offrange[0] >= 0) | |
5e27f0d5 | 309 | { |
7ad491c6 MS |
310 | if (offrange[1] < 0) |
311 | offrange[1] = offrange[0] <= maxoff ? maxoff : maxobjsize; | |
312 | else if (offrange[0] <= maxoff && offrange[1] > maxoff) | |
313 | offrange[1] = maxoff; | |
5e27f0d5 MS |
314 | } |
315 | } | |
316 | ||
6889a3ac MS |
317 | /* Based on the initial length of the destination STARTLEN, returns |
318 | the offset of the first write access from the beginning of | |
319 | the destination. Nonzero only for strcat-type of calls. */ | |
320 | ||
321 | offset_int builtin_access::write_off (tree startlen) const | |
322 | { | |
323 | if (detect_overlap != &builtin_access::strcat_overlap | |
324 | || !startlen || TREE_CODE (startlen) != INTEGER_CST) | |
325 | return 0; | |
326 | ||
327 | return wi::to_offset (startlen); | |
328 | } | |
329 | ||
a411ae9b MS |
330 | /* Ctor helper to set or extend OFFRANGE based on the OFFSET argument. |
331 | Pointer offsets are represented as unsigned sizetype but must be | |
332 | treated as signed. */ | |
5e27f0d5 MS |
333 | |
334 | void | |
335 | builtin_memref::extend_offset_range (tree offset) | |
336 | { | |
5e27f0d5 MS |
337 | if (TREE_CODE (offset) == INTEGER_CST) |
338 | { | |
339 | offset_int off = int_cst_value (offset); | |
340 | if (off != 0) | |
341 | { | |
342 | offrange[0] += off; | |
343 | offrange[1] += off; | |
344 | } | |
345 | return; | |
346 | } | |
347 | ||
348 | if (TREE_CODE (offset) == SSA_NAME) | |
349 | { | |
a411ae9b MS |
350 | /* A pointer offset is represented as sizetype but treated |
351 | as signed. */ | |
5e27f0d5 | 352 | wide_int min, max; |
30d15b51 | 353 | value_range_kind rng = VR_VARYING; |
e864d395 | 354 | value_range vr; |
30d15b51 | 355 | if (m_ptr_qry.rvals->range_of_expr (vr, offset, stmt)) |
e864d395 AH |
356 | { |
357 | rng = vr.kind (); | |
358 | if (!vr.undefined_p ()) | |
359 | { | |
360 | min = wi::to_wide (vr.min ()); | |
361 | max = wi::to_wide (vr.max ()); | |
362 | } | |
363 | } | |
30d15b51 | 364 | |
a411ae9b MS |
365 | if (rng == VR_ANTI_RANGE && wi::lts_p (max, min)) |
366 | { | |
367 | /* Convert an anti-range whose upper bound is less than | |
368 | its lower bound to a signed range. */ | |
369 | offrange[0] += offset_int::from (max + 1, SIGNED); | |
370 | offrange[1] += offset_int::from (min - 1, SIGNED); | |
371 | return; | |
372 | } | |
373 | ||
374 | if (rng == VR_RANGE | |
375 | && (DECL_P (base) || wi::lts_p (min, max))) | |
5e27f0d5 | 376 | { |
a411ae9b MS |
377 | /* Preserve the bounds of the range for an offset into |
378 | a known object (it may be adjusted later relative to | |
379 | a constant offset from its beginning). Otherwise use | |
380 | the bounds only when they are ascending when treated | |
381 | as signed. */ | |
5e27f0d5 MS |
382 | offrange[0] += offset_int::from (min, SIGNED); |
383 | offrange[1] += offset_int::from (max, SIGNED); | |
a411ae9b | 384 | return; |
5e27f0d5 | 385 | } |
a411ae9b MS |
386 | |
387 | /* Handle an anti-range the same as no range at all. */ | |
388 | gimple *stmt = SSA_NAME_DEF_STMT (offset); | |
389 | tree type; | |
390 | if (is_gimple_assign (stmt) | |
391 | && (type = TREE_TYPE (gimple_assign_rhs1 (stmt))) | |
392 | && INTEGRAL_TYPE_P (type)) | |
5e27f0d5 | 393 | { |
a411ae9b MS |
394 | tree_code code = gimple_assign_rhs_code (stmt); |
395 | if (code == NOP_EXPR) | |
5e27f0d5 MS |
396 | { |
397 | /* Use the bounds of the type of the NOP_EXPR operand | |
398 | even if it's signed. The result doesn't trigger | |
399 | warnings but makes their output more readable. */ | |
400 | offrange[0] += wi::to_offset (TYPE_MIN_VALUE (type)); | |
401 | offrange[1] += wi::to_offset (TYPE_MAX_VALUE (type)); | |
a411ae9b | 402 | return; |
5e27f0d5 | 403 | } |
5e27f0d5 | 404 | } |
5e27f0d5 MS |
405 | } |
406 | ||
a411ae9b MS |
407 | const offset_int maxoff = tree_to_shwi (max_object_size ()) >> 1; |
408 | const offset_int minoff = -maxoff - 1; | |
409 | ||
410 | offrange[0] += minoff; | |
411 | offrange[1] += maxoff; | |
5e27f0d5 MS |
412 | } |
413 | ||
414 | /* Determines the base object or pointer of the reference EXPR | |
415 | and the offset range from the beginning of the base. */ | |
416 | ||
417 | void | |
418 | builtin_memref::set_base_and_offset (tree expr) | |
419 | { | |
a411ae9b | 420 | tree offset = NULL_TREE; |
5e27f0d5 | 421 | |
cc8bea0a MS |
422 | if (TREE_CODE (expr) == SSA_NAME) |
423 | { | |
424 | /* Try to tease the offset out of the pointer. */ | |
425 | gimple *stmt = SSA_NAME_DEF_STMT (expr); | |
5e27f0d5 MS |
426 | if (!base |
427 | && gimple_assign_single_p (stmt) | |
cc8bea0a MS |
428 | && gimple_assign_rhs_code (stmt) == ADDR_EXPR) |
429 | expr = gimple_assign_rhs1 (stmt); | |
430 | else if (is_gimple_assign (stmt)) | |
431 | { | |
432 | tree_code code = gimple_assign_rhs_code (stmt); | |
0c0feae6 | 433 | if (CONVERT_EXPR_CODE_P (code)) |
cc8bea0a MS |
434 | { |
435 | tree rhs = gimple_assign_rhs1 (stmt); | |
436 | if (POINTER_TYPE_P (TREE_TYPE (rhs))) | |
437 | expr = gimple_assign_rhs1 (stmt); | |
5e27f0d5 MS |
438 | else |
439 | { | |
440 | base = expr; | |
441 | return; | |
442 | } | |
cc8bea0a MS |
443 | } |
444 | else if (code == POINTER_PLUS_EXPR) | |
445 | { | |
446 | expr = gimple_assign_rhs1 (stmt); | |
a411ae9b | 447 | offset = gimple_assign_rhs2 (stmt); |
cc8bea0a | 448 | } |
5e27f0d5 MS |
449 | else |
450 | { | |
451 | base = expr; | |
452 | return; | |
453 | } | |
454 | } | |
455 | else | |
456 | { | |
a411ae9b MS |
457 | /* FIXME: Handle PHI nodes in case like: |
458 | _12 = &MEM[(void *)&a + 2B] + _10; | |
459 | ||
460 | <bb> [local count: 1073741824]: | |
461 | # prephitmp_13 = PHI <_12, &MEM[(void *)&a + 2B]> | |
462 | memcpy (prephitmp_13, p_7(D), 6); */ | |
5e27f0d5 MS |
463 | base = expr; |
464 | return; | |
cc8bea0a MS |
465 | } |
466 | } | |
467 | ||
468 | if (TREE_CODE (expr) == ADDR_EXPR) | |
5e27f0d5 | 469 | expr = TREE_OPERAND (expr, 0); |
cc8bea0a | 470 | |
8286793a MS |
471 | /* Stash the reference for offset validation. */ |
472 | ref = expr; | |
473 | ||
5e27f0d5 MS |
474 | poly_int64 bitsize, bitpos; |
475 | tree var_off; | |
476 | machine_mode mode; | |
477 | int sign, reverse, vol; | |
cc8bea0a | 478 | |
5e27f0d5 MS |
479 | /* Determine the base object or pointer of the reference and |
480 | the constant bit offset from the beginning of the base. | |
481 | If the offset has a non-constant component, it will be in | |
482 | VAR_OFF. MODE, SIGN, REVERSE, and VOL are write only and | |
483 | unused here. */ | |
484 | base = get_inner_reference (expr, &bitsize, &bitpos, &var_off, | |
485 | &mode, &sign, &reverse, &vol); | |
cc8bea0a | 486 | |
8286793a MS |
487 | /* get_inner_reference is not expected to return null. */ |
488 | gcc_assert (base != NULL); | |
489 | ||
a411ae9b MS |
490 | if (offset) |
491 | extend_offset_range (offset); | |
492 | ||
5e27f0d5 | 493 | poly_int64 bytepos = exact_div (bitpos, BITS_PER_UNIT); |
cc8bea0a | 494 | |
ce811fc4 | 495 | /* Convert the poly_int64 offset to offset_int. The offset |
8286793a MS |
496 | should be constant but be prepared for it not to be just in |
497 | case. */ | |
498 | offset_int cstoff; | |
499 | if (bytepos.is_constant (&cstoff)) | |
5e27f0d5 | 500 | { |
8286793a MS |
501 | offrange[0] += cstoff; |
502 | offrange[1] += cstoff; | |
cc8bea0a | 503 | |
8286793a MS |
504 | /* Besides the reference saved above, also stash the offset |
505 | for validation. */ | |
506 | if (TREE_CODE (expr) == COMPONENT_REF) | |
507 | refoff = cstoff; | |
508 | } | |
509 | else | |
510 | offrange[1] += maxobjsize; | |
cc8bea0a | 511 | |
5e27f0d5 | 512 | if (var_off) |
cc8bea0a | 513 | { |
5e27f0d5 | 514 | if (TREE_CODE (var_off) == INTEGER_CST) |
aca52e6f | 515 | { |
8286793a | 516 | cstoff = wi::to_offset (var_off); |
5e27f0d5 MS |
517 | offrange[0] += cstoff; |
518 | offrange[1] += cstoff; | |
aca52e6f RS |
519 | } |
520 | else | |
5e27f0d5 | 521 | offrange[1] += maxobjsize; |
cc8bea0a MS |
522 | } |
523 | ||
5e27f0d5 | 524 | if (TREE_CODE (base) == MEM_REF) |
816fad6e | 525 | { |
6889a3ac | 526 | tree memrefoff = fold_convert (ptrdiff_type_node, TREE_OPERAND (base, 1)); |
5e27f0d5 | 527 | extend_offset_range (memrefoff); |
6889a3ac MS |
528 | |
529 | if (refoff != HOST_WIDE_INT_MIN | |
530 | && TREE_CODE (expr) == COMPONENT_REF) | |
531 | { | |
532 | /* Bump up the offset of the referenced subobject to reflect | |
533 | the offset to the enclosing object. For example, so that | |
534 | in | |
535 | struct S { char a, b[3]; } s[2]; | |
536 | strcpy (s[1].b, "1234"); | |
537 | REFOFF is set to s[1].b - (char*)s. */ | |
81011859 MS |
538 | offset_int off = tree_to_shwi (memrefoff); |
539 | refoff += off; | |
e7c482b0 RB |
540 | |
541 | if (!integer_zerop (memrefoff) | |
542 | && !COMPLETE_TYPE_P (TREE_TYPE (expr)) | |
543 | && multiple_of_p (sizetype, memrefoff, | |
544 | TYPE_SIZE_UNIT (TREE_TYPE (base)), true)) | |
545 | /* A non-zero offset into an array of struct with flexible array | |
546 | members implies that the array is empty because there is no | |
547 | way to initialize such a member when it belongs to an array. | |
548 | This must be some sort of a bug. */ | |
549 | refsize = 0; | |
550 | } | |
551 | ||
552 | base = TREE_OPERAND (base, 0); | |
816fad6e MS |
553 | } |
554 | ||
6889a3ac MS |
555 | if (TREE_CODE (ref) == COMPONENT_REF) |
556 | if (tree size = component_ref_size (ref)) | |
557 | if (TREE_CODE (size) == INTEGER_CST) | |
558 | refsize = wi::to_offset (size); | |
559 | ||
5e27f0d5 MS |
560 | if (TREE_CODE (base) == SSA_NAME) |
561 | set_base_and_offset (base); | |
cc8bea0a MS |
562 | } |
563 | ||
564 | /* Return error_mark_node if the signed offset exceeds the bounds | |
6889a3ac MS |
565 | of the address space (PTRDIFF_MAX). Otherwise, return either BASE |
566 | or REF when the offset exceeds the bounds of the BASE or REF object, | |
567 | and set OOBOFF to the past-the-end offset formed by the reference, | |
568 | including its size. OOBOFF is initially setto the range of offsets, | |
569 | and OOBOFF[2] to the offset of the first write access (nonzero for | |
570 | the strcat family). When STRICT is nonzero use REF size, when | |
571 | available, otherwise use BASE size. When STRICT is greater than 1, | |
572 | use the size of the last array member as the bound, otherwise treat | |
573 | such a member as a flexible array member. Return NULL when the offset | |
574 | is in bounds. */ | |
cc8bea0a MS |
575 | |
576 | tree | |
6889a3ac | 577 | builtin_memref::offset_out_of_bounds (int strict, offset_int ooboff[3]) const |
cc8bea0a | 578 | { |
a411ae9b MS |
579 | if (!ptr) |
580 | return NULL_TREE; | |
cc8bea0a | 581 | |
6889a3ac MS |
582 | /* The offset of the first write access or zero. */ |
583 | offset_int wroff = ooboff[2]; | |
584 | ||
cc8bea0a | 585 | /* A temporary, possibly adjusted, copy of the offset range. */ |
6889a3ac | 586 | offset_int offrng[2] = { ooboff[0], ooboff[1] }; |
cc8bea0a MS |
587 | |
588 | if (DECL_P (base) && TREE_CODE (TREE_TYPE (base)) == ARRAY_TYPE) | |
589 | { | |
56735d40 MS |
590 | /* Check for offset in an anti-range with a negative lower bound. |
591 | For such a range, consider only the non-negative subrange. */ | |
592 | if (offrng[1] < offrng[0] && offrng[1] < 0) | |
cc8bea0a MS |
593 | offrng[1] = maxobjsize; |
594 | } | |
595 | ||
596 | /* Conservative offset of the last byte of the referenced object. */ | |
597 | offset_int endoff; | |
598 | ||
599 | /* The bounds need not be ordered. Set HIB to use as the index | |
600 | of the larger of the bounds and LOB as the opposite. */ | |
601 | bool hib = wi::les_p (offrng[0], offrng[1]); | |
602 | bool lob = !hib; | |
603 | ||
700d4cb0 | 604 | /* Set to the size remaining in the object after subtracting |
6889a3ac MS |
605 | REFOFF. It may become negative as a result of negative indices |
606 | into the enclosing object, such as in: | |
607 | extern struct S { char a[4], b[3], c[1]; } *p; | |
608 | strcpy (p[-3].b, "123"); */ | |
609 | offset_int size = basesize; | |
610 | tree obj = base; | |
611 | ||
612 | const bool decl_p = DECL_P (obj); | |
613 | ||
cc8bea0a MS |
614 | if (basesize < 0) |
615 | { | |
6889a3ac | 616 | endoff = offrng[lob] + (sizrange[0] - wroff); |
cc8bea0a MS |
617 | |
618 | /* For a reference through a pointer to an object of unknown size | |
619 | all initial offsets are considered valid, positive as well as | |
620 | negative, since the pointer itself can point past the beginning | |
621 | of the object. However, the sum of the lower bound of the offset | |
622 | and that of the size must be less than or equal than PTRDIFF_MAX. */ | |
623 | if (endoff > maxobjsize) | |
624 | return error_mark_node; | |
625 | ||
6889a3ac MS |
626 | /* When the referenced subobject is known, the end offset must be |
627 | within its bounds. Otherwise there is nothing to do. */ | |
628 | if (strict | |
629 | && !decl_p | |
630 | && ref | |
631 | && refsize >= 0 | |
632 | && TREE_CODE (ref) == COMPONENT_REF) | |
633 | { | |
634 | /* If REFOFF is negative, SIZE will become negative here. */ | |
635 | size = refoff + refsize; | |
636 | obj = ref; | |
637 | } | |
638 | else | |
639 | return NULL_TREE; | |
cc8bea0a MS |
640 | } |
641 | ||
642 | /* A reference to an object of known size must be within the bounds | |
6889a3ac MS |
643 | of either the base object or the subobject (see above for when |
644 | a subobject can be used). */ | |
645 | if ((decl_p && offrng[hib] < 0) || offrng[lob] > size) | |
646 | return obj; | |
cc8bea0a MS |
647 | |
648 | /* The extent of the reference must also be within the bounds of | |
6889a3ac MS |
649 | the base object (if known) or the subobject or the maximum object |
650 | size otherwise. */ | |
651 | endoff = offrng[lob] + sizrange[0]; | |
cc8bea0a MS |
652 | if (endoff > maxobjsize) |
653 | return error_mark_node; | |
654 | ||
cc8bea0a | 655 | if (strict |
6889a3ac | 656 | && decl_p |
cc8bea0a | 657 | && ref |
6889a3ac MS |
658 | && refsize >= 0 |
659 | && TREE_CODE (ref) == COMPONENT_REF) | |
cc8bea0a | 660 | { |
6889a3ac MS |
661 | /* If the reference is to a member subobject of a declared object, |
662 | the offset must be within the bounds of the subobject. */ | |
663 | size = refoff + refsize; | |
664 | obj = ref; | |
cc8bea0a MS |
665 | } |
666 | ||
667 | if (endoff <= size) | |
668 | return NULL_TREE; | |
669 | ||
670 | /* Set the out-of-bounds offset range to be one greater than | |
671 | that delimited by the reference including its size. */ | |
6889a3ac | 672 | ooboff[lob] = size; |
cc8bea0a MS |
673 | |
674 | if (endoff > ooboff[lob]) | |
6889a3ac | 675 | ooboff[hib] = endoff - 1; |
cc8bea0a | 676 | else |
6889a3ac | 677 | ooboff[hib] = offrng[lob] + sizrange[1]; |
cc8bea0a MS |
678 | |
679 | return obj; | |
680 | } | |
681 | ||
682 | /* Create an association between the memory references DST and SRC | |
683 | for access by a call EXPR to a memory or string built-in funtion. */ | |
684 | ||
30d15b51 | 685 | builtin_access::builtin_access (pointer_query &ptrqry, gimple *call, |
e864d395 | 686 | builtin_memref &dst, |
cc8bea0a MS |
687 | builtin_memref &src) |
688 | : dstref (&dst), srcref (&src), sizrange (), ovloff (), ovlsiz (), | |
689 | dstoff (), srcoff (), dstsiz (), srcsiz () | |
690 | { | |
6889a3ac MS |
691 | dstoff[0] = dst.offrange[0]; |
692 | dstoff[1] = dst.offrange[1]; | |
693 | ||
cc8bea0a | 694 | /* Zero out since the offset_int ctors invoked above are no-op. */ |
cc8bea0a MS |
695 | srcoff[0] = srcoff[1] = 0; |
696 | dstsiz[0] = dstsiz[1] = 0; | |
697 | srcsiz[0] = srcsiz[1] = 0; | |
698 | ||
699 | /* Object Size Type to use to determine the size of the destination | |
700 | and source objects. Overridden below for raw memory functions. */ | |
701 | int ostype = 1; | |
702 | ||
703 | /* True when the size of one reference depends on the offset of | |
704 | itself or the other. */ | |
705 | bool depends_p = true; | |
706 | ||
707 | /* True when the size of the destination reference DSTREF has been | |
708 | determined from SRCREF and so needs to be adjusted by the latter's | |
709 | offset. Only meaningful for bounded string functions like strncpy. */ | |
710 | bool dstadjust_p = false; | |
711 | ||
712 | /* The size argument number (depends on the built-in). */ | |
713 | unsigned sizeargno = 2; | |
cc8bea0a MS |
714 | |
715 | tree func = gimple_call_fndecl (call); | |
716 | switch (DECL_FUNCTION_CODE (func)) | |
717 | { | |
718 | case BUILT_IN_MEMCPY: | |
719 | case BUILT_IN_MEMCPY_CHK: | |
cc8bea0a MS |
720 | case BUILT_IN_MEMPCPY: |
721 | case BUILT_IN_MEMPCPY_CHK: | |
cc8bea0a MS |
722 | ostype = 0; |
723 | depends_p = false; | |
724 | detect_overlap = &builtin_access::generic_overlap; | |
725 | break; | |
726 | ||
727 | case BUILT_IN_MEMMOVE: | |
728 | case BUILT_IN_MEMMOVE_CHK: | |
cc8bea0a MS |
729 | /* For memmove there is never any overlap to check for. */ |
730 | ostype = 0; | |
731 | depends_p = false; | |
732 | detect_overlap = &builtin_access::no_overlap; | |
733 | break; | |
734 | ||
a411ae9b MS |
735 | case BUILT_IN_MEMSET: |
736 | case BUILT_IN_MEMSET_CHK: | |
737 | /* For memset there is never any overlap to check for. */ | |
738 | ostype = 0; | |
739 | depends_p = false; | |
740 | detect_overlap = &builtin_access::no_overlap; | |
741 | break; | |
742 | ||
cc8bea0a MS |
743 | case BUILT_IN_STPNCPY: |
744 | case BUILT_IN_STPNCPY_CHK: | |
745 | case BUILT_IN_STRNCPY: | |
746 | case BUILT_IN_STRNCPY_CHK: | |
747 | dstref->strbounded_p = true; | |
748 | detect_overlap = &builtin_access::strcpy_overlap; | |
749 | break; | |
750 | ||
751 | case BUILT_IN_STPCPY: | |
752 | case BUILT_IN_STPCPY_CHK: | |
cc8bea0a MS |
753 | case BUILT_IN_STRCPY: |
754 | case BUILT_IN_STRCPY_CHK: | |
cc8bea0a MS |
755 | detect_overlap = &builtin_access::strcpy_overlap; |
756 | break; | |
757 | ||
758 | case BUILT_IN_STRCAT: | |
759 | case BUILT_IN_STRCAT_CHK: | |
cc8bea0a MS |
760 | detect_overlap = &builtin_access::strcat_overlap; |
761 | break; | |
762 | ||
763 | case BUILT_IN_STRNCAT: | |
764 | case BUILT_IN_STRNCAT_CHK: | |
765 | dstref->strbounded_p = true; | |
766 | srcref->strbounded_p = true; | |
767 | detect_overlap = &builtin_access::strcat_overlap; | |
768 | break; | |
769 | ||
770 | default: | |
771 | /* Handle other string functions here whose access may need | |
772 | to be validated for in-bounds offsets and non-overlapping | |
31db0fe0 | 773 | copies. */ |
cc8bea0a MS |
774 | return; |
775 | } | |
776 | ||
cc8bea0a MS |
777 | /* Try to determine the size of the base object. compute_objsize |
778 | expects a pointer so create one if BASE is a non-pointer object. */ | |
cc8bea0a MS |
779 | if (dst.basesize < 0) |
780 | { | |
30d15b51 MS |
781 | access_ref aref; |
782 | if (ptrqry.get_ref (dst.base, call, &aref, ostype) && aref.base0) | |
783 | dst.basesize = aref.sizrng[1]; | |
cc8bea0a | 784 | else |
30d15b51 | 785 | dst.basesize = HOST_WIDE_INT_MIN; |
cc8bea0a MS |
786 | } |
787 | ||
a411ae9b | 788 | if (src.base && src.basesize < 0) |
cc8bea0a | 789 | { |
30d15b51 MS |
790 | access_ref aref; |
791 | if (ptrqry.get_ref (src.base, call, &aref, ostype) && aref.base0) | |
792 | src.basesize = aref.sizrng[1]; | |
cc8bea0a | 793 | else |
30d15b51 | 794 | src.basesize = HOST_WIDE_INT_MIN; |
cc8bea0a MS |
795 | } |
796 | ||
30d15b51 MS |
797 | const offset_int maxobjsize = dst.maxobjsize; |
798 | ||
6889a3ac MS |
799 | /* Make adjustments for references to the same object by string |
800 | built-in functions to reflect the constraints imposed by | |
801 | the function. */ | |
cc8bea0a MS |
802 | |
803 | /* For bounded string functions determine the range of the bound | |
804 | on the access. For others, the range stays unbounded. */ | |
805 | offset_int bounds[2] = { maxobjsize, maxobjsize }; | |
806 | if (dstref->strbounded_p) | |
807 | { | |
9a0cbb60 MS |
808 | unsigned nargs = gimple_call_num_args (call); |
809 | if (nargs <= sizeargno) | |
810 | return; | |
811 | ||
cc8bea0a MS |
812 | tree size = gimple_call_arg (call, sizeargno); |
813 | tree range[2]; | |
30d15b51 | 814 | if (get_size_range (ptrqry.rvals, size, call, range, true)) |
cc8bea0a MS |
815 | { |
816 | bounds[0] = wi::to_offset (range[0]); | |
817 | bounds[1] = wi::to_offset (range[1]); | |
818 | } | |
819 | ||
820 | /* If both references' size ranges are indeterminate use the last | |
821 | (size) argument from the function call as a substitute. This | |
822 | may only be necessary for strncpy (but not for memcpy where | |
823 | the size range would have been already determined this way). */ | |
824 | if (dstref->sizrange[0] == 0 && dstref->sizrange[1] == maxobjsize | |
825 | && srcref->sizrange[0] == 0 && srcref->sizrange[1] == maxobjsize) | |
826 | { | |
827 | dstref->sizrange[0] = bounds[0]; | |
828 | dstref->sizrange[1] = bounds[1]; | |
829 | } | |
830 | } | |
831 | ||
6889a3ac | 832 | bool dstsize_set = false; |
cc8bea0a MS |
833 | /* The size range of one reference involving the same base object |
834 | can be determined from the size range of the other reference. | |
835 | This makes it possible to compute accurate offsets for warnings | |
836 | involving functions like strcpy where the length of just one of | |
837 | the two arguments is known (determined by tree-ssa-strlen). */ | |
838 | if (dstref->sizrange[0] == 0 && dstref->sizrange[1] == maxobjsize) | |
839 | { | |
840 | /* When the destination size is unknown set it to the size of | |
841 | the source. */ | |
842 | dstref->sizrange[0] = srcref->sizrange[0]; | |
843 | dstref->sizrange[1] = srcref->sizrange[1]; | |
6889a3ac | 844 | dstsize_set = true; |
cc8bea0a MS |
845 | } |
846 | else if (srcref->sizrange[0] == 0 && srcref->sizrange[1] == maxobjsize) | |
847 | { | |
3942060c MS |
848 | /* When the size of the source access is unknown set it to the size |
849 | of the destination first and adjust it later if necessary. */ | |
cc8bea0a MS |
850 | srcref->sizrange[0] = dstref->sizrange[0]; |
851 | srcref->sizrange[1] = dstref->sizrange[1]; | |
852 | ||
853 | if (depends_p) | |
854 | { | |
855 | if (dstref->strbounded_p) | |
856 | { | |
6889a3ac MS |
857 | /* Read access by strncpy is constrained by the third |
858 | argument but except for a zero bound is at least one. */ | |
3942060c MS |
859 | srcref->sizrange[0] = bounds[1] > 0 ? 1 : 0; |
860 | offset_int bound = wi::umin (srcref->basesize, bounds[1]); | |
6889a3ac MS |
861 | if (bound < srcref->sizrange[1]) |
862 | srcref->sizrange[1] = bound; | |
cc8bea0a | 863 | } |
cc8bea0a MS |
864 | /* For string functions, adjust the size range of the source |
865 | reference by the inverse boundaries of the offset (because | |
c7c9468a | 866 | the higher the offset into the string the shorter its |
cc8bea0a | 867 | length). */ |
c7c9468a JL |
868 | if (srcref->offrange[1] >= 0 |
869 | && srcref->offrange[1] < srcref->sizrange[0]) | |
cc8bea0a MS |
870 | srcref->sizrange[0] -= srcref->offrange[1]; |
871 | else | |
3942060c | 872 | srcref->sizrange[0] = 1; |
cc8bea0a MS |
873 | |
874 | if (srcref->offrange[0] > 0) | |
875 | { | |
876 | if (srcref->offrange[0] < srcref->sizrange[1]) | |
877 | srcref->sizrange[1] -= srcref->offrange[0]; | |
878 | else | |
879 | srcref->sizrange[1] = 0; | |
880 | } | |
881 | ||
882 | dstadjust_p = true; | |
883 | } | |
884 | } | |
885 | ||
886 | if (detect_overlap == &builtin_access::generic_overlap) | |
887 | { | |
888 | if (dstref->strbounded_p) | |
889 | { | |
890 | dstref->sizrange[0] = bounds[0]; | |
891 | dstref->sizrange[1] = bounds[1]; | |
892 | ||
893 | if (dstref->sizrange[0] < srcref->sizrange[0]) | |
894 | srcref->sizrange[0] = dstref->sizrange[0]; | |
895 | ||
896 | if (dstref->sizrange[1] < srcref->sizrange[1]) | |
897 | srcref->sizrange[1] = dstref->sizrange[1]; | |
898 | } | |
899 | } | |
900 | else if (detect_overlap == &builtin_access::strcpy_overlap) | |
901 | { | |
902 | if (!dstref->strbounded_p) | |
903 | { | |
904 | /* For strcpy, adjust the destination size range to match that | |
905 | of the source computed above. */ | |
906 | if (depends_p && dstadjust_p) | |
907 | { | |
908 | dstref->sizrange[0] = srcref->sizrange[0]; | |
909 | dstref->sizrange[1] = srcref->sizrange[1]; | |
910 | } | |
911 | } | |
912 | } | |
6889a3ac MS |
913 | else if (!dstsize_set && detect_overlap == &builtin_access::strcat_overlap) |
914 | { | |
915 | dstref->sizrange[0] += srcref->sizrange[0] - 1; | |
916 | dstref->sizrange[1] += srcref->sizrange[1] - 1; | |
917 | } | |
cc8bea0a MS |
918 | |
919 | if (dstref->strbounded_p) | |
920 | { | |
921 | /* For strncpy, adjust the destination size range to match that | |
922 | of the source computed above. */ | |
923 | dstref->sizrange[0] = bounds[0]; | |
924 | dstref->sizrange[1] = bounds[1]; | |
925 | ||
926 | if (bounds[0] < srcref->sizrange[0]) | |
927 | srcref->sizrange[0] = bounds[0]; | |
928 | ||
929 | if (bounds[1] < srcref->sizrange[1]) | |
930 | srcref->sizrange[1] = bounds[1]; | |
931 | } | |
932 | } | |
933 | ||
934 | offset_int | |
935 | builtin_access::overlap_size (const offset_int a[2], const offset_int b[2], | |
936 | offset_int *off) | |
937 | { | |
938 | const offset_int *p = a; | |
939 | const offset_int *q = b; | |
940 | ||
941 | /* Point P at the bigger of the two ranges and Q at the smaller. */ | |
942 | if (wi::lts_p (a[1] - a[0], b[1] - b[0])) | |
943 | { | |
944 | p = b; | |
945 | q = a; | |
946 | } | |
947 | ||
948 | if (p[0] < q[0]) | |
949 | { | |
950 | if (p[1] < q[0]) | |
951 | return 0; | |
952 | ||
953 | *off = q[0]; | |
954 | return wi::smin (p[1], q[1]) - q[0]; | |
955 | } | |
956 | ||
957 | if (q[1] < p[0]) | |
958 | return 0; | |
959 | ||
960 | off[0] = p[0]; | |
961 | return q[1] - p[0]; | |
962 | } | |
963 | ||
964 | /* Return true if the bounded mempry (memcpy amd similar) or string function | |
965 | access (strncpy and similar) ACS overlaps. */ | |
966 | ||
967 | bool | |
968 | builtin_access::generic_overlap () | |
969 | { | |
970 | builtin_access &acs = *this; | |
971 | const builtin_memref *dstref = acs.dstref; | |
972 | const builtin_memref *srcref = acs.srcref; | |
973 | ||
974 | gcc_assert (dstref->base == srcref->base); | |
975 | ||
a411ae9b | 976 | const offset_int maxobjsize = acs.dstref->maxobjsize; |
cc8bea0a MS |
977 | |
978 | offset_int maxsize = dstref->basesize < 0 ? maxobjsize : dstref->basesize; | |
cc8bea0a MS |
979 | |
980 | /* Adjust the larger bounds of the offsets (which may be the first | |
981 | element if the lower bound is larger than the upper bound) to | |
982 | make them valid for the smallest access (if possible) but no smaller | |
983 | than the smaller bounds. */ | |
984 | gcc_assert (wi::les_p (acs.dstoff[0], acs.dstoff[1])); | |
985 | ||
986 | if (maxsize < acs.dstoff[1] + acs.dstsiz[0]) | |
987 | acs.dstoff[1] = maxsize - acs.dstsiz[0]; | |
988 | if (acs.dstoff[1] < acs.dstoff[0]) | |
989 | acs.dstoff[1] = acs.dstoff[0]; | |
990 | ||
991 | gcc_assert (wi::les_p (acs.srcoff[0], acs.srcoff[1])); | |
992 | ||
993 | if (maxsize < acs.srcoff[1] + acs.srcsiz[0]) | |
994 | acs.srcoff[1] = maxsize - acs.srcsiz[0]; | |
995 | if (acs.srcoff[1] < acs.srcoff[0]) | |
996 | acs.srcoff[1] = acs.srcoff[0]; | |
997 | ||
998 | /* Determine the minimum and maximum space for the access given | |
999 | the offsets. */ | |
1000 | offset_int space[2]; | |
1001 | space[0] = wi::abs (acs.dstoff[0] - acs.srcoff[0]); | |
1002 | space[1] = space[0]; | |
1003 | ||
1004 | offset_int d = wi::abs (acs.dstoff[0] - acs.srcoff[1]); | |
1005 | if (acs.srcsiz[0] > 0) | |
1006 | { | |
1007 | if (d < space[0]) | |
1008 | space[0] = d; | |
1009 | ||
1010 | if (space[1] < d) | |
1011 | space[1] = d; | |
1012 | } | |
1013 | else | |
1014 | space[1] = acs.dstsiz[1]; | |
1015 | ||
1016 | d = wi::abs (acs.dstoff[1] - acs.srcoff[0]); | |
1017 | if (d < space[0]) | |
1018 | space[0] = d; | |
1019 | ||
1020 | if (space[1] < d) | |
1021 | space[1] = d; | |
1022 | ||
1023 | /* Treat raw memory functions both of whose references are bounded | |
1024 | as special and permit uncertain overlaps to go undetected. For | |
1025 | all kinds of constant offset and constant size accesses, if | |
1026 | overlap isn't certain it is not possible. */ | |
1027 | bool overlap_possible = space[0] < acs.dstsiz[1]; | |
1028 | if (!overlap_possible) | |
1029 | return false; | |
1030 | ||
1031 | bool overlap_certain = space[1] < acs.dstsiz[0]; | |
1032 | ||
1033 | /* True when the size of one reference depends on the offset of | |
1034 | the other. */ | |
1035 | bool depends_p = detect_overlap != &builtin_access::generic_overlap; | |
1036 | ||
5e27f0d5 MS |
1037 | if (!overlap_certain) |
1038 | { | |
1039 | if (!dstref->strbounded_p && !depends_p) | |
8286793a | 1040 | /* Memcpy only considers certain overlap. */ |
5e27f0d5 MS |
1041 | return false; |
1042 | ||
1043 | /* There's no way to distinguish an access to the same member | |
1044 | of a structure from one to two distinct members of the same | |
1045 | structure. Give up to avoid excessive false positives. */ | |
8286793a MS |
1046 | tree basetype = TREE_TYPE (dstref->base); |
1047 | ||
1048 | if (POINTER_TYPE_P (basetype)) | |
1049 | basetype = TREE_TYPE (basetype); | |
1050 | else | |
1051 | while (TREE_CODE (basetype) == ARRAY_TYPE) | |
1052 | basetype = TREE_TYPE (basetype); | |
1053 | ||
5e27f0d5 MS |
1054 | if (RECORD_OR_UNION_TYPE_P (basetype)) |
1055 | return false; | |
1056 | } | |
cc8bea0a MS |
1057 | |
1058 | /* True for stpcpy and strcpy. */ | |
1059 | bool stxcpy_p = (!dstref->strbounded_p | |
1060 | && detect_overlap == &builtin_access::strcpy_overlap); | |
1061 | ||
1062 | if (dstref->refoff >= 0 | |
1063 | && srcref->refoff >= 0 | |
1064 | && dstref->refoff != srcref->refoff | |
1065 | && (stxcpy_p || dstref->strbounded_p || srcref->strbounded_p)) | |
1066 | return false; | |
1067 | ||
1068 | offset_int siz[2] = { maxobjsize + 1, 0 }; | |
1069 | ||
1070 | ovloff[0] = HOST_WIDE_INT_MAX; | |
1071 | ovloff[1] = HOST_WIDE_INT_MIN; | |
1072 | ||
cc8bea0a MS |
1073 | if (stxcpy_p) |
1074 | { | |
cc8bea0a MS |
1075 | /* Iterate over the extreme locations (on the horizontal axis formed |
1076 | by their offsets) and sizes of two regions and find their smallest | |
1077 | and largest overlap and the corresponding offsets. */ | |
1078 | for (unsigned i = 0; i != 2; ++i) | |
1079 | { | |
1080 | const offset_int a[2] = { | |
1081 | acs.dstoff[i], acs.dstoff[i] + acs.dstsiz[!i] | |
1082 | }; | |
1083 | ||
1084 | const offset_int b[2] = { | |
1085 | acs.srcoff[i], acs.srcoff[i] + acs.srcsiz[!i] | |
1086 | }; | |
1087 | ||
1088 | offset_int off; | |
1089 | offset_int sz = overlap_size (a, b, &off); | |
1090 | if (sz < siz[0]) | |
1091 | siz[0] = sz; | |
1092 | ||
1093 | if (siz[1] <= sz) | |
1094 | siz[1] = sz; | |
1095 | ||
1096 | if (sz != 0) | |
1097 | { | |
1098 | if (wi::lts_p (off, ovloff[0])) | |
1099 | ovloff[0] = off.to_shwi (); | |
1100 | if (wi::lts_p (ovloff[1], off)) | |
1101 | ovloff[1] = off.to_shwi (); | |
1102 | } | |
1103 | } | |
1104 | } | |
1105 | else | |
1106 | { | |
cc8bea0a | 1107 | /* Iterate over the extreme locations (on the horizontal axis |
3942060c MS |
1108 | formed by their offsets) and sizes of the two regions and |
1109 | find their smallest and largest overlap and the corresponding | |
cc8bea0a MS |
1110 | offsets. */ |
1111 | ||
1112 | for (unsigned io = 0; io != 2; ++io) | |
1113 | for (unsigned is = 0; is != 2; ++is) | |
1114 | { | |
1115 | const offset_int a[2] = { | |
1116 | acs.dstoff[io], acs.dstoff[io] + acs.dstsiz[is] | |
1117 | }; | |
1118 | ||
1119 | for (unsigned jo = 0; jo != 2; ++jo) | |
1120 | for (unsigned js = 0; js != 2; ++js) | |
1121 | { | |
cc8bea0a MS |
1122 | const offset_int b[2] = { |
1123 | acs.srcoff[jo], acs.srcoff[jo] + acs.srcsiz[js] | |
1124 | }; | |
1125 | ||
1126 | offset_int off; | |
1127 | offset_int sz = overlap_size (a, b, &off); | |
1128 | if (sz < siz[0]) | |
1129 | siz[0] = sz; | |
1130 | ||
1131 | if (siz[1] <= sz) | |
1132 | siz[1] = sz; | |
1133 | ||
1134 | if (sz != 0) | |
1135 | { | |
1136 | if (wi::lts_p (off, ovloff[0])) | |
1137 | ovloff[0] = off.to_shwi (); | |
1138 | if (wi::lts_p (ovloff[1], off)) | |
1139 | ovloff[1] = off.to_shwi (); | |
1140 | } | |
1141 | } | |
1142 | } | |
1143 | } | |
1144 | ||
1145 | ovlsiz[0] = siz[0].to_shwi (); | |
1146 | ovlsiz[1] = siz[1].to_shwi (); | |
1147 | ||
3942060c | 1148 | /* Adjust the overlap offset range to reflect the overlap size range. */ |
cc8bea0a | 1149 | if (ovlsiz[0] == 0 && ovlsiz[1] > 1) |
3942060c | 1150 | ovloff[1] = ovloff[0] + ovlsiz[1] - 1; |
cc8bea0a MS |
1151 | |
1152 | return true; | |
1153 | } | |
1154 | ||
1155 | /* Return true if the strcat-like access overlaps. */ | |
1156 | ||
1157 | bool | |
1158 | builtin_access::strcat_overlap () | |
1159 | { | |
1160 | builtin_access &acs = *this; | |
1161 | const builtin_memref *dstref = acs.dstref; | |
1162 | const builtin_memref *srcref = acs.srcref; | |
1163 | ||
1164 | gcc_assert (dstref->base == srcref->base); | |
1165 | ||
a411ae9b | 1166 | const offset_int maxobjsize = acs.dstref->maxobjsize; |
cc8bea0a MS |
1167 | |
1168 | gcc_assert (dstref->base && dstref->base == srcref->base); | |
1169 | ||
1170 | /* Adjust for strcat-like accesses. */ | |
1171 | ||
1172 | /* As a special case for strcat, set the DSTREF offsets to the length | |
6889a3ac MS |
1173 | of the destination string since the function starts writing over |
1174 | its terminating nul, and set the destination size to 1 for the length | |
1175 | of the nul. */ | |
1176 | acs.dstoff[0] += dstsiz[0] - srcref->sizrange[0]; | |
1177 | acs.dstoff[1] += dstsiz[1] - srcref->sizrange[1]; | |
cc8bea0a MS |
1178 | |
1179 | bool strfunc_unknown_args = acs.dstsiz[0] == 0 && acs.dstsiz[1] != 0; | |
1180 | ||
1181 | /* The lower bound is zero when the size is unknown because then | |
1182 | overlap is not certain. */ | |
1183 | acs.dstsiz[0] = strfunc_unknown_args ? 0 : 1; | |
1184 | acs.dstsiz[1] = 1; | |
1185 | ||
1186 | offset_int maxsize = dstref->basesize < 0 ? maxobjsize : dstref->basesize; | |
cc8bea0a MS |
1187 | |
1188 | /* For references to the same base object, determine if there's a pair | |
1189 | of valid offsets into the two references such that access between | |
1190 | them doesn't overlap. Adjust both upper bounds to be valid for | |
1191 | the smaller size (i.e., at most MAXSIZE - SIZE). */ | |
1192 | ||
1193 | if (maxsize < acs.dstoff[1] + acs.dstsiz[0]) | |
1194 | acs.dstoff[1] = maxsize - acs.dstsiz[0]; | |
1195 | ||
1196 | if (maxsize < acs.srcoff[1] + acs.srcsiz[0]) | |
1197 | acs.srcoff[1] = maxsize - acs.srcsiz[0]; | |
1198 | ||
1199 | /* Check to see if there's enough space for both accesses without | |
1200 | overlap. Determine the optimistic (maximum) amount of available | |
1201 | space. */ | |
1202 | offset_int space; | |
1203 | if (acs.dstoff[0] <= acs.srcoff[0]) | |
1204 | { | |
1205 | if (acs.dstoff[1] < acs.srcoff[1]) | |
1206 | space = acs.srcoff[1] + acs.srcsiz[0] - acs.dstoff[0]; | |
1207 | else | |
1208 | space = acs.dstoff[1] + acs.dstsiz[0] - acs.srcoff[0]; | |
1209 | } | |
1210 | else | |
1211 | space = acs.dstoff[1] + acs.dstsiz[0] - acs.srcoff[0]; | |
1212 | ||
1213 | /* Overlap is certain if the distance between the farthest offsets | |
1214 | of the opposite accesses is less than the sum of the lower bounds | |
1215 | of the sizes of the two accesses. */ | |
1216 | bool overlap_certain = space < acs.dstsiz[0] + acs.srcsiz[0]; | |
1217 | ||
1218 | /* For a constant-offset, constant size access, consider the largest | |
1219 | distance between the offset bounds and the lower bound of the access | |
1220 | size. If the overlap isn't certain return success. */ | |
1221 | if (!overlap_certain | |
1222 | && acs.dstoff[0] == acs.dstoff[1] | |
1223 | && acs.srcoff[0] == acs.srcoff[1] | |
1224 | && acs.dstsiz[0] == acs.dstsiz[1] | |
1225 | && acs.srcsiz[0] == acs.srcsiz[1]) | |
1226 | return false; | |
1227 | ||
1228 | /* Overlap is not certain but may be possible. */ | |
1229 | ||
1230 | offset_int access_min = acs.dstsiz[0] + acs.srcsiz[0]; | |
1231 | ||
1232 | /* Determine the conservative (minimum) amount of space. */ | |
1233 | space = wi::abs (acs.dstoff[0] - acs.srcoff[0]); | |
1234 | offset_int d = wi::abs (acs.dstoff[0] - acs.srcoff[1]); | |
1235 | if (d < space) | |
1236 | space = d; | |
1237 | d = wi::abs (acs.dstoff[1] - acs.srcoff[0]); | |
1238 | if (d < space) | |
1239 | space = d; | |
1240 | ||
1241 | /* For a strict test (used for strcpy and similar with unknown or | |
1242 | variable bounds or sizes), consider the smallest distance between | |
1243 | the offset bounds and either the upper bound of the access size | |
1244 | if known, or the lower bound otherwise. */ | |
1245 | if (access_min <= space && (access_min != 0 || !strfunc_unknown_args)) | |
1246 | return false; | |
1247 | ||
1248 | /* When strcat overlap is certain it is always a single byte: | |
816fad6e | 1249 | the terminating NUL, regardless of offsets and sizes. When |
cc8bea0a MS |
1250 | overlap is only possible its range is [0, 1]. */ |
1251 | acs.ovlsiz[0] = dstref->sizrange[0] == dstref->sizrange[1] ? 1 : 0; | |
1252 | acs.ovlsiz[1] = 1; | |
cc8bea0a | 1253 | |
6889a3ac MS |
1254 | offset_int endoff |
1255 | = dstref->offrange[0] + (dstref->sizrange[0] - srcref->sizrange[0]); | |
816fad6e MS |
1256 | if (endoff <= srcref->offrange[0]) |
1257 | acs.ovloff[0] = wi::smin (maxobjsize, srcref->offrange[0]).to_shwi (); | |
1258 | else | |
1259 | acs.ovloff[0] = wi::smin (maxobjsize, endoff).to_shwi (); | |
1260 | ||
1261 | acs.sizrange[0] = wi::smax (wi::abs (endoff - srcref->offrange[0]) + 1, | |
1262 | srcref->sizrange[0]).to_shwi (); | |
1263 | if (dstref->offrange[0] == dstref->offrange[1]) | |
1264 | { | |
1265 | if (srcref->offrange[0] == srcref->offrange[1]) | |
1266 | acs.ovloff[1] = acs.ovloff[0]; | |
1267 | else | |
1268 | acs.ovloff[1] | |
1269 | = wi::smin (maxobjsize, | |
1270 | srcref->offrange[1] + srcref->sizrange[1]).to_shwi (); | |
1271 | } | |
1272 | else | |
1273 | acs.ovloff[1] | |
1274 | = wi::smin (maxobjsize, | |
1275 | dstref->offrange[1] + dstref->sizrange[1]).to_shwi (); | |
1276 | ||
1277 | if (acs.sizrange[0] == 0) | |
1278 | acs.sizrange[0] = 1; | |
cc8bea0a MS |
1279 | acs.sizrange[1] = wi::smax (acs.dstsiz[1], srcref->sizrange[1]).to_shwi (); |
1280 | return true; | |
1281 | } | |
1282 | ||
1283 | /* Return true if the strcpy-like access overlaps. */ | |
1284 | ||
1285 | bool | |
1286 | builtin_access::strcpy_overlap () | |
1287 | { | |
1288 | return generic_overlap (); | |
1289 | } | |
1290 | ||
a2c2cee9 MS |
1291 | /* For a BASE of array type, clamp REFOFF to at most [0, BASE_SIZE] |
1292 | if known, or [0, MAXOBJSIZE] otherwise. */ | |
1293 | ||
1294 | static void | |
1295 | clamp_offset (tree base, offset_int refoff[2], offset_int maxobjsize) | |
1296 | { | |
1297 | if (!base || TREE_CODE (TREE_TYPE (base)) != ARRAY_TYPE) | |
1298 | return; | |
1299 | ||
1300 | if (refoff[0] < 0 && refoff[1] >= 0) | |
1301 | refoff[0] = 0; | |
1302 | ||
1303 | if (refoff[1] < refoff[0]) | |
1304 | { | |
1305 | offset_int maxsize = maxobjsize; | |
1306 | if (tree size = TYPE_SIZE_UNIT (TREE_TYPE (base))) | |
1307 | maxsize = wi::to_offset (size); | |
1308 | ||
1309 | refoff[1] = wi::umin (refoff[1], maxsize); | |
1310 | } | |
1311 | } | |
cc8bea0a MS |
1312 | |
1313 | /* Return true if DSTREF and SRCREF describe accesses that either overlap | |
1314 | one another or that, in order not to overlap, would imply that the size | |
1315 | of the referenced object(s) exceeds the maximum size of an object. Set | |
1316 | Otherwise, if DSTREF and SRCREF do not definitely overlap (even though | |
1317 | they may overlap in a way that's not apparent from the available data), | |
1318 | return false. */ | |
1319 | ||
1320 | bool | |
1321 | builtin_access::overlap () | |
1322 | { | |
1323 | builtin_access &acs = *this; | |
1324 | ||
a411ae9b | 1325 | const offset_int maxobjsize = dstref->maxobjsize; |
cc8bea0a MS |
1326 | |
1327 | acs.sizrange[0] = wi::smax (dstref->sizrange[0], | |
1328 | srcref->sizrange[0]).to_shwi (); | |
1329 | acs.sizrange[1] = wi::smax (dstref->sizrange[1], | |
1330 | srcref->sizrange[1]).to_shwi (); | |
1331 | ||
1332 | /* Check to see if the two references refer to regions that are | |
1333 | too large not to overlap in the address space (whose maximum | |
1334 | size is PTRDIFF_MAX). */ | |
1335 | offset_int size = dstref->sizrange[0] + srcref->sizrange[0]; | |
1336 | if (maxobjsize < size) | |
1337 | { | |
1338 | acs.ovloff[0] = (maxobjsize - dstref->sizrange[0]).to_shwi (); | |
1339 | acs.ovlsiz[0] = (size - maxobjsize).to_shwi (); | |
1340 | return true; | |
1341 | } | |
1342 | ||
1343 | /* If both base objects aren't known return the maximum possible | |
1344 | offset that would make them not overlap. */ | |
1345 | if (!dstref->base || !srcref->base) | |
1346 | return false; | |
1347 | ||
c7c9468a JL |
1348 | /* If the base object is an array adjust the bounds of the offset |
1349 | to be non-negative and within the bounds of the array if possible. */ | |
a2c2cee9 | 1350 | clamp_offset (dstref->base, acs.dstoff, maxobjsize); |
c7c9468a JL |
1351 | |
1352 | acs.srcoff[0] = srcref->offrange[0]; | |
1353 | acs.srcoff[1] = srcref->offrange[1]; | |
cc8bea0a | 1354 | |
a2c2cee9 | 1355 | clamp_offset (srcref->base, acs.srcoff, maxobjsize); |
cc8bea0a | 1356 | |
c7c9468a JL |
1357 | /* When the upper bound of the offset is less than the lower bound |
1358 | the former is the result of a negative offset being represented | |
1359 | as a large positive value or vice versa. The resulting range is | |
1360 | a union of two subranges: [MIN, UB] and [LB, MAX]. Since such | |
1361 | a union is not representable using the current data structure | |
1362 | replace it with the full range of offsets. */ | |
cc8bea0a | 1363 | if (acs.dstoff[1] < acs.dstoff[0]) |
c7c9468a JL |
1364 | { |
1365 | acs.dstoff[0] = -maxobjsize - 1; | |
1366 | acs.dstoff[1] = maxobjsize; | |
1367 | } | |
cc8bea0a MS |
1368 | |
1369 | /* Validate the offset and size of each reference on its own first. | |
1370 | This is independent of whether or not the base objects are the | |
1371 | same. Normally, this would have already been detected and | |
1372 | diagnosed by -Warray-bounds, unless it has been disabled. */ | |
1373 | offset_int maxoff = acs.dstoff[0] + dstref->sizrange[0]; | |
1374 | if (maxobjsize < maxoff) | |
1375 | { | |
1376 | acs.ovlsiz[0] = (maxoff - maxobjsize).to_shwi (); | |
1377 | acs.ovloff[0] = acs.dstoff[0].to_shwi () - acs.ovlsiz[0]; | |
1378 | return true; | |
1379 | } | |
1380 | ||
1381 | /* Repeat the same as above but for the source offsets. */ | |
1382 | if (acs.srcoff[1] < acs.srcoff[0]) | |
c7c9468a JL |
1383 | { |
1384 | acs.srcoff[0] = -maxobjsize - 1; | |
1385 | acs.srcoff[1] = maxobjsize; | |
1386 | } | |
cc8bea0a MS |
1387 | |
1388 | maxoff = acs.srcoff[0] + srcref->sizrange[0]; | |
1389 | if (maxobjsize < maxoff) | |
1390 | { | |
1391 | acs.ovlsiz[0] = (maxoff - maxobjsize).to_shwi (); | |
1392 | acs.ovlsiz[1] = (acs.srcoff[0] + srcref->sizrange[1] | |
1393 | - maxobjsize).to_shwi (); | |
1394 | acs.ovloff[0] = acs.srcoff[0].to_shwi () - acs.ovlsiz[0]; | |
1395 | return true; | |
1396 | } | |
1397 | ||
1398 | if (dstref->base != srcref->base) | |
1399 | return false; | |
1400 | ||
1401 | acs.dstsiz[0] = dstref->sizrange[0]; | |
1402 | acs.dstsiz[1] = dstref->sizrange[1]; | |
1403 | ||
1404 | acs.srcsiz[0] = srcref->sizrange[0]; | |
1405 | acs.srcsiz[1] = srcref->sizrange[1]; | |
1406 | ||
1407 | /* Call the appropriate function to determine the overlap. */ | |
1408 | if ((this->*detect_overlap) ()) | |
1409 | { | |
816fad6e MS |
1410 | if (!sizrange[1]) |
1411 | { | |
1412 | /* Unless the access size range has already been set, do so here. */ | |
1413 | sizrange[0] = wi::smax (acs.dstsiz[0], srcref->sizrange[0]).to_shwi (); | |
1414 | sizrange[1] = wi::smax (acs.dstsiz[1], srcref->sizrange[1]).to_shwi (); | |
1415 | } | |
cc8bea0a MS |
1416 | return true; |
1417 | } | |
1418 | ||
1419 | return false; | |
1420 | } | |
1421 | ||
1422 | /* Attempt to detect and diagnose an overlapping copy in a call expression | |
700d4cb0 | 1423 | EXPR involving an access ACS to a built-in memory or string function. |
cc8bea0a MS |
1424 | Return true when one has been detected, false otherwise. */ |
1425 | ||
1426 | static bool | |
8a45b051 | 1427 | maybe_diag_overlap (location_t loc, gimple *call, builtin_access &acs) |
cc8bea0a MS |
1428 | { |
1429 | if (!acs.overlap ()) | |
1430 | return false; | |
1431 | ||
e9e2bad7 | 1432 | if (warning_suppressed_p (call, OPT_Wrestrict)) |
213694e5 MS |
1433 | return true; |
1434 | ||
cc8bea0a MS |
1435 | /* For convenience. */ |
1436 | const builtin_memref &dstref = *acs.dstref; | |
1437 | const builtin_memref &srcref = *acs.srcref; | |
1438 | ||
1439 | /* Determine the range of offsets and sizes of the overlap if it | |
1440 | exists and issue diagnostics. */ | |
1441 | HOST_WIDE_INT *ovloff = acs.ovloff; | |
1442 | HOST_WIDE_INT *ovlsiz = acs.ovlsiz; | |
1443 | HOST_WIDE_INT *sizrange = acs.sizrange; | |
1444 | ||
1445 | tree func = gimple_call_fndecl (call); | |
1446 | ||
1447 | /* To avoid a combinatorial explosion of diagnostics format the offsets | |
1448 | or their ranges as strings and use them in the warning calls below. */ | |
1449 | char offstr[3][64]; | |
1450 | ||
1451 | if (dstref.offrange[0] == dstref.offrange[1] | |
1452 | || dstref.offrange[1] > HOST_WIDE_INT_MAX) | |
a6fd2cd7 MS |
1453 | sprintf (offstr[0], HOST_WIDE_INT_PRINT_DEC, |
1454 | dstref.offrange[0].to_shwi ()); | |
cc8bea0a | 1455 | else |
a6fd2cd7 MS |
1456 | sprintf (offstr[0], |
1457 | "[" HOST_WIDE_INT_PRINT_DEC ", " HOST_WIDE_INT_PRINT_DEC "]", | |
1458 | dstref.offrange[0].to_shwi (), | |
1459 | dstref.offrange[1].to_shwi ()); | |
cc8bea0a MS |
1460 | |
1461 | if (srcref.offrange[0] == srcref.offrange[1] | |
1462 | || srcref.offrange[1] > HOST_WIDE_INT_MAX) | |
a6fd2cd7 MS |
1463 | sprintf (offstr[1], |
1464 | HOST_WIDE_INT_PRINT_DEC, | |
1465 | srcref.offrange[0].to_shwi ()); | |
cc8bea0a | 1466 | else |
a6fd2cd7 MS |
1467 | sprintf (offstr[1], |
1468 | "[" HOST_WIDE_INT_PRINT_DEC ", " HOST_WIDE_INT_PRINT_DEC "]", | |
1469 | srcref.offrange[0].to_shwi (), | |
1470 | srcref.offrange[1].to_shwi ()); | |
cc8bea0a MS |
1471 | |
1472 | if (ovloff[0] == ovloff[1] || !ovloff[1]) | |
a6fd2cd7 | 1473 | sprintf (offstr[2], HOST_WIDE_INT_PRINT_DEC, ovloff[0]); |
cc8bea0a | 1474 | else |
a6fd2cd7 MS |
1475 | sprintf (offstr[2], |
1476 | "[" HOST_WIDE_INT_PRINT_DEC ", " HOST_WIDE_INT_PRINT_DEC "]", | |
1477 | ovloff[0], ovloff[1]); | |
cc8bea0a | 1478 | |
a411ae9b | 1479 | const offset_int maxobjsize = dstref.maxobjsize; |
cc8bea0a MS |
1480 | bool must_overlap = ovlsiz[0] > 0; |
1481 | ||
1482 | if (ovlsiz[1] == 0) | |
1483 | ovlsiz[1] = ovlsiz[0]; | |
1484 | ||
1485 | if (must_overlap) | |
1486 | { | |
1487 | /* Issue definitive "overlaps" diagnostic in this block. */ | |
1488 | ||
1489 | if (sizrange[0] == sizrange[1]) | |
1490 | { | |
1491 | if (ovlsiz[0] == ovlsiz[1]) | |
1492 | warning_at (loc, OPT_Wrestrict, | |
1493 | sizrange[0] == 1 | |
1494 | ? (ovlsiz[0] == 1 | |
6d3bab5d | 1495 | ? G_("%qD accessing %wu byte at offsets %s " |
cc8bea0a | 1496 | "and %s overlaps %wu byte at offset %s") |
6d3bab5d | 1497 | : G_("%qD accessing %wu byte at offsets %s " |
cc8bea0a MS |
1498 | "and %s overlaps %wu bytes at offset " |
1499 | "%s")) | |
1500 | : (ovlsiz[0] == 1 | |
6d3bab5d | 1501 | ? G_("%qD accessing %wu bytes at offsets %s " |
cc8bea0a | 1502 | "and %s overlaps %wu byte at offset %s") |
6d3bab5d | 1503 | : G_("%qD accessing %wu bytes at offsets %s " |
cc8bea0a MS |
1504 | "and %s overlaps %wu bytes at offset " |
1505 | "%s")), | |
6d3bab5d | 1506 | func, sizrange[0], |
cc8bea0a MS |
1507 | offstr[0], offstr[1], ovlsiz[0], offstr[2]); |
1508 | else if (ovlsiz[1] >= 0 && ovlsiz[1] < maxobjsize.to_shwi ()) | |
15d3974b | 1509 | warning_n (loc, OPT_Wrestrict, sizrange[0], |
6d3bab5d | 1510 | "%qD accessing %wu byte at offsets %s " |
15d3974b JJ |
1511 | "and %s overlaps between %wu and %wu bytes " |
1512 | "at offset %s", | |
6d3bab5d | 1513 | "%qD accessing %wu bytes at offsets %s " |
15d3974b JJ |
1514 | "and %s overlaps between %wu and %wu bytes " |
1515 | "at offset %s", | |
6d3bab5d | 1516 | func, sizrange[0], offstr[0], offstr[1], |
15d3974b | 1517 | ovlsiz[0], ovlsiz[1], offstr[2]); |
cc8bea0a | 1518 | else |
15d3974b | 1519 | warning_n (loc, OPT_Wrestrict, sizrange[0], |
6d3bab5d | 1520 | "%qD accessing %wu byte at offsets %s and " |
15d3974b | 1521 | "%s overlaps %wu or more bytes at offset %s", |
6d3bab5d | 1522 | "%qD accessing %wu bytes at offsets %s and " |
15d3974b | 1523 | "%s overlaps %wu or more bytes at offset %s", |
6d3bab5d | 1524 | func, sizrange[0], |
15d3974b | 1525 | offstr[0], offstr[1], ovlsiz[0], offstr[2]); |
cc8bea0a MS |
1526 | return true; |
1527 | } | |
1528 | ||
1529 | if (sizrange[1] >= 0 && sizrange[1] < maxobjsize.to_shwi ()) | |
1530 | { | |
1531 | if (ovlsiz[0] == ovlsiz[1]) | |
15d3974b | 1532 | warning_n (loc, OPT_Wrestrict, ovlsiz[0], |
6d3bab5d | 1533 | "%qD accessing between %wu and %wu bytes " |
15d3974b JJ |
1534 | "at offsets %s and %s overlaps %wu byte at " |
1535 | "offset %s", | |
6d3bab5d | 1536 | "%qD accessing between %wu and %wu bytes " |
15d3974b JJ |
1537 | "at offsets %s and %s overlaps %wu bytes " |
1538 | "at offset %s", | |
6d3bab5d | 1539 | func, sizrange[0], sizrange[1], |
15d3974b | 1540 | offstr[0], offstr[1], ovlsiz[0], offstr[2]); |
cc8bea0a MS |
1541 | else if (ovlsiz[1] >= 0 && ovlsiz[1] < maxobjsize.to_shwi ()) |
1542 | warning_at (loc, OPT_Wrestrict, | |
6d3bab5d | 1543 | "%qD accessing between %wu and %wu bytes at " |
cc8bea0a MS |
1544 | "offsets %s and %s overlaps between %wu and %wu " |
1545 | "bytes at offset %s", | |
6d3bab5d | 1546 | func, sizrange[0], sizrange[1], |
cc8bea0a MS |
1547 | offstr[0], offstr[1], ovlsiz[0], ovlsiz[1], |
1548 | offstr[2]); | |
1549 | else | |
1550 | warning_at (loc, OPT_Wrestrict, | |
6d3bab5d | 1551 | "%qD accessing between %wu and %wu bytes at " |
cc8bea0a MS |
1552 | "offsets %s and %s overlaps %wu or more bytes " |
1553 | "at offset %s", | |
6d3bab5d | 1554 | func, sizrange[0], sizrange[1], |
cc8bea0a MS |
1555 | offstr[0], offstr[1], ovlsiz[0], offstr[2]); |
1556 | return true; | |
1557 | } | |
1558 | ||
1559 | if (ovlsiz[0] != ovlsiz[1]) | |
1560 | ovlsiz[1] = maxobjsize.to_shwi (); | |
1561 | ||
1562 | if (ovlsiz[0] == ovlsiz[1]) | |
15d3974b | 1563 | warning_n (loc, OPT_Wrestrict, ovlsiz[0], |
6d3bab5d | 1564 | "%qD accessing %wu or more bytes at offsets " |
15d3974b | 1565 | "%s and %s overlaps %wu byte at offset %s", |
6d3bab5d | 1566 | "%qD accessing %wu or more bytes at offsets " |
15d3974b | 1567 | "%s and %s overlaps %wu bytes at offset %s", |
6d3bab5d | 1568 | func, sizrange[0], offstr[0], offstr[1], |
15d3974b | 1569 | ovlsiz[0], offstr[2]); |
cc8bea0a MS |
1570 | else if (ovlsiz[1] >= 0 && ovlsiz[1] < maxobjsize.to_shwi ()) |
1571 | warning_at (loc, OPT_Wrestrict, | |
6d3bab5d | 1572 | "%qD accessing %wu or more bytes at offsets %s " |
cc8bea0a MS |
1573 | "and %s overlaps between %wu and %wu bytes " |
1574 | "at offset %s", | |
6d3bab5d | 1575 | func, sizrange[0], offstr[0], offstr[1], |
cc8bea0a MS |
1576 | ovlsiz[0], ovlsiz[1], offstr[2]); |
1577 | else | |
1578 | warning_at (loc, OPT_Wrestrict, | |
6d3bab5d | 1579 | "%qD accessing %wu or more bytes at offsets %s " |
cc8bea0a | 1580 | "and %s overlaps %wu or more bytes at offset %s", |
6d3bab5d | 1581 | func, sizrange[0], offstr[0], offstr[1], |
cc8bea0a MS |
1582 | ovlsiz[0], offstr[2]); |
1583 | return true; | |
1584 | } | |
1585 | ||
cc8bea0a MS |
1586 | /* Use more concise wording when one of the offsets is unbounded |
1587 | to avoid confusing the user with large and mostly meaningless | |
1588 | numbers. */ | |
816fad6e MS |
1589 | bool open_range; |
1590 | if (DECL_P (dstref.base) && TREE_CODE (TREE_TYPE (dstref.base)) == ARRAY_TYPE) | |
1591 | open_range = ((dstref.offrange[0] == 0 | |
1592 | && dstref.offrange[1] == maxobjsize) | |
1593 | || (srcref.offrange[0] == 0 | |
1594 | && srcref.offrange[1] == maxobjsize)); | |
1595 | else | |
1596 | open_range = ((dstref.offrange[0] == -maxobjsize - 1 | |
1597 | && dstref.offrange[1] == maxobjsize) | |
1598 | || (srcref.offrange[0] == -maxobjsize - 1 | |
1599 | && srcref.offrange[1] == maxobjsize)); | |
cc8bea0a MS |
1600 | |
1601 | if (sizrange[0] == sizrange[1] || sizrange[1] == 1) | |
1602 | { | |
1603 | if (ovlsiz[1] == 1) | |
1604 | { | |
1605 | if (open_range) | |
15d3974b | 1606 | warning_n (loc, OPT_Wrestrict, sizrange[1], |
6d3bab5d | 1607 | "%qD accessing %wu byte may overlap " |
15d3974b | 1608 | "%wu byte", |
6d3bab5d | 1609 | "%qD accessing %wu bytes may overlap " |
15d3974b | 1610 | "%wu byte", |
6d3bab5d | 1611 | func, sizrange[1], ovlsiz[1]); |
cc8bea0a | 1612 | else |
15d3974b | 1613 | warning_n (loc, OPT_Wrestrict, sizrange[1], |
6d3bab5d | 1614 | "%qD accessing %wu byte at offsets %s " |
15d3974b | 1615 | "and %s may overlap %wu byte at offset %s", |
6d3bab5d | 1616 | "%qD accessing %wu bytes at offsets %s " |
15d3974b | 1617 | "and %s may overlap %wu byte at offset %s", |
6d3bab5d | 1618 | func, sizrange[1], offstr[0], offstr[1], |
15d3974b | 1619 | ovlsiz[1], offstr[2]); |
cc8bea0a MS |
1620 | return true; |
1621 | } | |
1622 | ||
1623 | if (open_range) | |
15d3974b | 1624 | warning_n (loc, OPT_Wrestrict, sizrange[1], |
6d3bab5d | 1625 | "%qD accessing %wu byte may overlap " |
15d3974b | 1626 | "up to %wu bytes", |
6d3bab5d | 1627 | "%qD accessing %wu bytes may overlap " |
15d3974b | 1628 | "up to %wu bytes", |
6d3bab5d | 1629 | func, sizrange[1], ovlsiz[1]); |
cc8bea0a | 1630 | else |
15d3974b | 1631 | warning_n (loc, OPT_Wrestrict, sizrange[1], |
6d3bab5d | 1632 | "%qD accessing %wu byte at offsets %s and " |
15d3974b | 1633 | "%s may overlap up to %wu bytes at offset %s", |
6d3bab5d | 1634 | "%qD accessing %wu bytes at offsets %s and " |
15d3974b | 1635 | "%s may overlap up to %wu bytes at offset %s", |
6d3bab5d | 1636 | func, sizrange[1], offstr[0], offstr[1], |
15d3974b | 1637 | ovlsiz[1], offstr[2]); |
cc8bea0a MS |
1638 | return true; |
1639 | } | |
1640 | ||
1641 | if (sizrange[1] >= 0 && sizrange[1] < maxobjsize.to_shwi ()) | |
1642 | { | |
1643 | if (open_range) | |
15d3974b | 1644 | warning_n (loc, OPT_Wrestrict, ovlsiz[1], |
6d3bab5d | 1645 | "%qD accessing between %wu and %wu bytes " |
15d3974b | 1646 | "may overlap %wu byte", |
6d3bab5d | 1647 | "%qD accessing between %wu and %wu bytes " |
15d3974b | 1648 | "may overlap up to %wu bytes", |
6d3bab5d | 1649 | func, sizrange[0], sizrange[1], ovlsiz[1]); |
cc8bea0a | 1650 | else |
15d3974b | 1651 | warning_n (loc, OPT_Wrestrict, ovlsiz[1], |
6d3bab5d | 1652 | "%qD accessing between %wu and %wu bytes " |
15d3974b JJ |
1653 | "at offsets %s and %s may overlap %wu byte " |
1654 | "at offset %s", | |
6d3bab5d | 1655 | "%qD accessing between %wu and %wu bytes " |
15d3974b JJ |
1656 | "at offsets %s and %s may overlap up to %wu " |
1657 | "bytes at offset %s", | |
6d3bab5d | 1658 | func, sizrange[0], sizrange[1], |
15d3974b | 1659 | offstr[0], offstr[1], ovlsiz[1], offstr[2]); |
cc8bea0a MS |
1660 | return true; |
1661 | } | |
1662 | ||
15d3974b | 1663 | warning_n (loc, OPT_Wrestrict, ovlsiz[1], |
6d3bab5d | 1664 | "%qD accessing %wu or more bytes at offsets %s " |
15d3974b | 1665 | "and %s may overlap %wu byte at offset %s", |
6d3bab5d | 1666 | "%qD accessing %wu or more bytes at offsets %s " |
15d3974b | 1667 | "and %s may overlap up to %wu bytes at offset %s", |
6d3bab5d | 1668 | func, sizrange[0], offstr[0], offstr[1], |
15d3974b | 1669 | ovlsiz[1], offstr[2]); |
cc8bea0a MS |
1670 | |
1671 | return true; | |
1672 | } | |
1673 | ||
287ef129 MS |
1674 | /* Validate REF size and offsets in an expression passed as an argument |
1675 | to a CALL to a built-in function FUNC to make sure they are within | |
1676 | the bounds of the referenced object if its size is known, or | |
1677 | PTRDIFF_MAX otherwise. DO_WARN is true when a diagnostic should | |
1678 | be issued, false otherwise. | |
1679 | Both initial values of the offsets and their final value computed | |
1680 | by the function by incrementing the initial value by the size are | |
e9e2bad7 MS |
1681 | validated. Return the warning number if the offsets are not valid |
1682 | and a diagnostic has been issued, or would have been issued if | |
1683 | DO_WARN had been true, otherwise an invalid warning number. */ | |
cc8bea0a | 1684 | |
e9e2bad7 | 1685 | static opt_code |
55ace4d1 | 1686 | maybe_diag_access_bounds (gimple *call, tree func, int strict, |
6889a3ac MS |
1687 | const builtin_memref &ref, offset_int wroff, |
1688 | bool do_warn) | |
cc8bea0a | 1689 | { |
6d3bab5d | 1690 | location_t loc = gimple_location (call); |
a411ae9b | 1691 | const offset_int maxobjsize = ref.maxobjsize; |
287ef129 MS |
1692 | |
1693 | /* Check for excessive size first and regardless of warning options | |
1694 | since the result is used to make codegen decisions. */ | |
1695 | if (ref.sizrange[0] > maxobjsize) | |
1696 | { | |
e9e2bad7 | 1697 | const opt_code opt = OPT_Wstringop_overflow_; |
287ef129 MS |
1698 | /* Return true without issuing a warning. */ |
1699 | if (!do_warn) | |
e9e2bad7 | 1700 | return opt; |
287ef129 | 1701 | |
e9e2bad7 MS |
1702 | if (ref.ref && warning_suppressed_p (ref.ref, OPT_Wstringop_overflow_)) |
1703 | return no_warning; | |
287ef129 | 1704 | |
e9e2bad7 | 1705 | bool warned = false; |
287ef129 MS |
1706 | if (warn_stringop_overflow) |
1707 | { | |
287ef129 | 1708 | if (ref.sizrange[0] == ref.sizrange[1]) |
e9e2bad7 | 1709 | warned = warning_at (loc, opt, |
6d3bab5d | 1710 | "%qD specified bound %wu " |
e9e2bad7 | 1711 | "exceeds maximum object size %wu", |
6d3bab5d | 1712 | func, ref.sizrange[0].to_uhwi (), |
e9e2bad7 MS |
1713 | maxobjsize.to_uhwi ()); |
1714 | else | |
1715 | warned = warning_at (loc, opt, | |
6d3bab5d | 1716 | "%qD specified bound between %wu and %wu " |
e9e2bad7 | 1717 | "exceeds maximum object size %wu", |
6d3bab5d | 1718 | func, ref.sizrange[0].to_uhwi (), |
e9e2bad7 MS |
1719 | ref.sizrange[1].to_uhwi (), |
1720 | maxobjsize.to_uhwi ()); | |
1721 | return warned ? opt : no_warning; | |
287ef129 MS |
1722 | } |
1723 | } | |
1724 | ||
213694e5 | 1725 | /* Check for out-bounds pointers regardless of warning options since |
6889a3ac MS |
1726 | the result is used to make codegen decisions. An excessive WROFF |
1727 | can only come up as a result of an invalid strncat bound and is | |
1728 | diagnosed separately using a more meaningful warning. */ | |
1729 | if (maxobjsize < wroff) | |
1730 | wroff = 0; | |
1731 | offset_int ooboff[] = { ref.offrange[0], ref.offrange[1], wroff }; | |
213694e5 MS |
1732 | tree oobref = ref.offset_out_of_bounds (strict, ooboff); |
1733 | if (!oobref) | |
e9e2bad7 | 1734 | return no_warning; |
cc8bea0a | 1735 | |
e9e2bad7 | 1736 | const opt_code opt = OPT_Warray_bounds; |
213694e5 MS |
1737 | /* Return true without issuing a warning. */ |
1738 | if (!do_warn) | |
e9e2bad7 | 1739 | return opt; |
213694e5 MS |
1740 | |
1741 | if (!warn_array_bounds) | |
e9e2bad7 | 1742 | return no_warning; |
21150aba | 1743 | |
e9e2bad7 MS |
1744 | if (warning_suppressed_p (ref.ptr, opt) |
1745 | || (ref.ref && warning_suppressed_p (ref.ref, opt))) | |
1746 | return no_warning; | |
cc8bea0a | 1747 | |
cc8bea0a MS |
1748 | char rangestr[2][64]; |
1749 | if (ooboff[0] == ooboff[1] | |
1750 | || (ooboff[0] != ref.offrange[0] | |
1751 | && ooboff[0].to_shwi () >= ooboff[1].to_shwi ())) | |
1752 | sprintf (rangestr[0], "%lli", (long long) ooboff[0].to_shwi ()); | |
1753 | else | |
1754 | sprintf (rangestr[0], "[%lli, %lli]", | |
1755 | (long long) ooboff[0].to_shwi (), | |
1756 | (long long) ooboff[1].to_shwi ()); | |
1757 | ||
e3329a78 MS |
1758 | bool warned = false; |
1759 | ||
cc8bea0a MS |
1760 | if (oobref == error_mark_node) |
1761 | { | |
1762 | if (ref.sizrange[0] == ref.sizrange[1]) | |
287ef129 MS |
1763 | sprintf (rangestr[1], "%llu", |
1764 | (unsigned long long) ref.sizrange[0].to_shwi ()); | |
cc8bea0a MS |
1765 | else |
1766 | sprintf (rangestr[1], "[%lli, %lli]", | |
287ef129 MS |
1767 | (unsigned long long) ref.sizrange[0].to_uhwi (), |
1768 | (unsigned long long) ref.sizrange[1].to_uhwi ()); | |
cc8bea0a | 1769 | |
e3329a78 MS |
1770 | tree type; |
1771 | ||
cc8bea0a MS |
1772 | if (DECL_P (ref.base) |
1773 | && TREE_CODE (type = TREE_TYPE (ref.base)) == ARRAY_TYPE) | |
1774 | { | |
097f82ec | 1775 | auto_diagnostic_group d; |
e9e2bad7 | 1776 | if (warning_at (loc, opt, |
6d3bab5d | 1777 | "%qD pointer overflow between offset %s " |
cc8bea0a | 1778 | "and size %s accessing array %qD with type %qT", |
6d3bab5d | 1779 | func, rangestr[0], rangestr[1], ref.base, type)) |
e3329a78 MS |
1780 | { |
1781 | inform (DECL_SOURCE_LOCATION (ref.base), | |
1782 | "array %qD declared here", ref.base); | |
1783 | warned = true; | |
1784 | } | |
cc8bea0a | 1785 | else |
e9e2bad7 | 1786 | warned = warning_at (loc, opt, |
6d3bab5d | 1787 | "%qD pointer overflow between offset %s " |
e3329a78 | 1788 | "and size %s", |
6d3bab5d | 1789 | func, rangestr[0], rangestr[1]); |
cc8bea0a MS |
1790 | } |
1791 | else | |
e9e2bad7 | 1792 | warned = warning_at (loc, opt, |
6d3bab5d | 1793 | "%qD pointer overflow between offset %s " |
e3329a78 | 1794 | "and size %s", |
6d3bab5d | 1795 | func, rangestr[0], rangestr[1]); |
cc8bea0a MS |
1796 | } |
1797 | else if (oobref == ref.base) | |
1798 | { | |
cc8bea0a MS |
1799 | /* True when the offset formed by an access to the reference |
1800 | is out of bounds, rather than the initial offset wich is | |
1801 | in bounds. This implies access past the end. */ | |
1802 | bool form = ooboff[0] != ref.offrange[0]; | |
1803 | ||
1804 | if (DECL_P (ref.base)) | |
1805 | { | |
097f82ec | 1806 | auto_diagnostic_group d; |
cc8bea0a | 1807 | if ((ref.basesize < maxobjsize |
e9e2bad7 | 1808 | && warning_at (loc, opt, |
cc8bea0a | 1809 | form |
6d3bab5d | 1810 | ? G_("%qD forming offset %s is out of " |
cc8bea0a MS |
1811 | "the bounds [0, %wu] of object %qD with " |
1812 | "type %qT") | |
6d3bab5d | 1813 | : G_("%qD offset %s is out of the bounds " |
cc8bea0a | 1814 | "[0, %wu] of object %qD with type %qT"), |
6d3bab5d | 1815 | func, rangestr[0], ref.basesize.to_uhwi (), |
cc8bea0a | 1816 | ref.base, TREE_TYPE (ref.base))) |
e9e2bad7 | 1817 | || warning_at (loc, opt, |
cc8bea0a | 1818 | form |
6d3bab5d | 1819 | ? G_("%qD forming offset %s is out of " |
cc8bea0a | 1820 | "the bounds of object %qD with type %qT") |
6d3bab5d | 1821 | : G_("%qD offset %s is out of the bounds " |
cc8bea0a | 1822 | "of object %qD with type %qT"), |
6d3bab5d | 1823 | func, rangestr[0], |
cc8bea0a | 1824 | ref.base, TREE_TYPE (ref.base))) |
e3329a78 MS |
1825 | { |
1826 | inform (DECL_SOURCE_LOCATION (ref.base), | |
1827 | "%qD declared here", ref.base); | |
1828 | warned = true; | |
1829 | } | |
cc8bea0a MS |
1830 | } |
1831 | else if (ref.basesize < maxobjsize) | |
e9e2bad7 | 1832 | warned = warning_at (loc, opt, |
e3329a78 | 1833 | form |
6d3bab5d | 1834 | ? G_("%qD forming offset %s is out " |
e3329a78 | 1835 | "of the bounds [0, %wu]") |
6d3bab5d | 1836 | : G_("%qD offset %s is out " |
e3329a78 | 1837 | "of the bounds [0, %wu]"), |
6d3bab5d | 1838 | func, rangestr[0], ref.basesize.to_uhwi ()); |
cc8bea0a | 1839 | else |
e9e2bad7 | 1840 | warned = warning_at (loc, opt, |
e3329a78 | 1841 | form |
6d3bab5d MS |
1842 | ? G_("%qD forming offset %s is out of bounds") |
1843 | : G_("%qD offset %s is out of bounds"), | |
1844 | func, rangestr[0]); | |
cc8bea0a MS |
1845 | } |
1846 | else if (TREE_CODE (ref.ref) == MEM_REF) | |
1847 | { | |
6889a3ac MS |
1848 | tree refop = TREE_OPERAND (ref.ref, 0); |
1849 | tree type = TREE_TYPE (refop); | |
cc8bea0a MS |
1850 | if (POINTER_TYPE_P (type)) |
1851 | type = TREE_TYPE (type); | |
1852 | type = TYPE_MAIN_VARIANT (type); | |
1853 | ||
e9e2bad7 | 1854 | if (warning_at (loc, opt, |
6d3bab5d | 1855 | "%qD offset %s from the object at %qE is out " |
6889a3ac | 1856 | "of the bounds of %qT", |
6d3bab5d | 1857 | func, rangestr[0], ref.base, type)) |
6889a3ac MS |
1858 | { |
1859 | if (TREE_CODE (ref.ref) == COMPONENT_REF) | |
1860 | refop = TREE_OPERAND (ref.ref, 1); | |
1861 | if (DECL_P (refop)) | |
1862 | inform (DECL_SOURCE_LOCATION (refop), | |
1863 | "subobject %qD declared here", refop); | |
1864 | warned = true; | |
1865 | } | |
cc8bea0a MS |
1866 | } |
1867 | else | |
1868 | { | |
6889a3ac | 1869 | tree refop = TREE_OPERAND (ref.ref, 0); |
e3329a78 MS |
1870 | tree type = TYPE_MAIN_VARIANT (TREE_TYPE (ref.ref)); |
1871 | ||
e9e2bad7 | 1872 | if (warning_at (loc, opt, |
6d3bab5d | 1873 | "%qD offset %s from the object at %qE is out " |
6889a3ac MS |
1874 | "of the bounds of referenced subobject %qD with " |
1875 | "type %qT at offset %wi", | |
6d3bab5d | 1876 | func, rangestr[0], ref.base, |
6889a3ac MS |
1877 | TREE_OPERAND (ref.ref, 1), type, |
1878 | ref.refoff.to_shwi ())) | |
1879 | { | |
1880 | if (TREE_CODE (ref.ref) == COMPONENT_REF) | |
1881 | refop = TREE_OPERAND (ref.ref, 1); | |
1882 | if (DECL_P (refop)) | |
1883 | inform (DECL_SOURCE_LOCATION (refop), | |
1884 | "subobject %qD declared here", refop); | |
1885 | warned = true; | |
1886 | } | |
cc8bea0a MS |
1887 | } |
1888 | ||
e9e2bad7 | 1889 | return warned ? opt : no_warning; |
cc8bea0a MS |
1890 | } |
1891 | ||
1892 | /* Check a CALL statement for restrict-violations and issue warnings | |
1893 | if/when appropriate. */ | |
1894 | ||
30d15b51 MS |
1895 | void |
1896 | pass_wrestrict::check_call (gimple *call) | |
cc8bea0a MS |
1897 | { |
1898 | /* Avoid checking the call if it has already been diagnosed for | |
1899 | some reason. */ | |
e9e2bad7 | 1900 | if (warning_suppressed_p (call, OPT_Wrestrict)) |
cc8bea0a MS |
1901 | return; |
1902 | ||
1903 | tree func = gimple_call_fndecl (call); | |
3d78e008 | 1904 | if (!func || !fndecl_built_in_p (func, BUILT_IN_NORMAL)) |
cc8bea0a MS |
1905 | return; |
1906 | ||
cc8bea0a MS |
1907 | /* Argument number to extract from the call (depends on the built-in |
1908 | and its kind). */ | |
1909 | unsigned dst_idx = -1; | |
1910 | unsigned src_idx = -1; | |
1911 | unsigned bnd_idx = -1; | |
1912 | ||
1913 | /* Is this CALL to a string function (as opposed to one to a raw | |
1914 | memory function). */ | |
1915 | bool strfun = true; | |
1916 | ||
1917 | switch (DECL_FUNCTION_CODE (func)) | |
1918 | { | |
1919 | case BUILT_IN_MEMCPY: | |
1920 | case BUILT_IN_MEMCPY_CHK: | |
cc8bea0a MS |
1921 | case BUILT_IN_MEMPCPY: |
1922 | case BUILT_IN_MEMPCPY_CHK: | |
cc8bea0a MS |
1923 | case BUILT_IN_MEMMOVE: |
1924 | case BUILT_IN_MEMMOVE_CHK: | |
cc8bea0a MS |
1925 | strfun = false; |
1926 | /* Fall through. */ | |
1927 | ||
1928 | case BUILT_IN_STPNCPY: | |
1929 | case BUILT_IN_STPNCPY_CHK: | |
1930 | case BUILT_IN_STRNCAT: | |
1931 | case BUILT_IN_STRNCAT_CHK: | |
1932 | case BUILT_IN_STRNCPY: | |
1933 | case BUILT_IN_STRNCPY_CHK: | |
1934 | dst_idx = 0; | |
31db0fe0 ML |
1935 | src_idx = 1; |
1936 | bnd_idx = 2; | |
cc8bea0a MS |
1937 | break; |
1938 | ||
a411ae9b MS |
1939 | case BUILT_IN_MEMSET: |
1940 | case BUILT_IN_MEMSET_CHK: | |
1941 | dst_idx = 0; | |
1942 | bnd_idx = 2; | |
1943 | break; | |
1944 | ||
cc8bea0a MS |
1945 | case BUILT_IN_STPCPY: |
1946 | case BUILT_IN_STPCPY_CHK: | |
cc8bea0a MS |
1947 | case BUILT_IN_STRCPY: |
1948 | case BUILT_IN_STRCPY_CHK: | |
cc8bea0a MS |
1949 | case BUILT_IN_STRCAT: |
1950 | case BUILT_IN_STRCAT_CHK: | |
cc8bea0a | 1951 | dst_idx = 0; |
31db0fe0 | 1952 | src_idx = 1; |
cc8bea0a MS |
1953 | break; |
1954 | ||
1955 | default: | |
1956 | /* Handle other string functions here whose access may need | |
1957 | to be validated for in-bounds offsets and non-overlapping | |
31db0fe0 | 1958 | copies. */ |
cc8bea0a MS |
1959 | return; |
1960 | } | |
1961 | ||
1962 | unsigned nargs = gimple_call_num_args (call); | |
1963 | ||
1964 | tree dst = dst_idx < nargs ? gimple_call_arg (call, dst_idx) : NULL_TREE; | |
1965 | tree src = src_idx < nargs ? gimple_call_arg (call, src_idx) : NULL_TREE; | |
1966 | tree dstwr = bnd_idx < nargs ? gimple_call_arg (call, bnd_idx) : NULL_TREE; | |
1967 | ||
1968 | /* For string functions with an unspecified or unknown bound, | |
1969 | assume the size of the access is one. */ | |
1970 | if (!dstwr && strfun) | |
1971 | dstwr = size_one_node; | |
1972 | ||
2438cb6a MS |
1973 | /* DST and SRC can be null for a call with an insufficient number |
1974 | of arguments to a built-in function declared without a protype. */ | |
a411ae9b | 1975 | if (!dst || (src_idx < nargs && !src)) |
cf3fc0e8 MS |
1976 | return; |
1977 | ||
1978 | /* DST, SRC, or DSTWR can also have the wrong type in a call to | |
1979 | a function declared without a prototype. Avoid checking such | |
1980 | invalid calls. */ | |
1981 | if (TREE_CODE (TREE_TYPE (dst)) != POINTER_TYPE | |
a411ae9b | 1982 | || (src && TREE_CODE (TREE_TYPE (src)) != POINTER_TYPE) |
cf3fc0e8 MS |
1983 | || (dstwr && !INTEGRAL_TYPE_P (TREE_TYPE (dstwr)))) |
1984 | return; | |
1985 | ||
30d15b51 | 1986 | opt_code opt = check_bounds_or_overlap (m_ptr_qry, call, dst, src, dstwr, |
e9e2bad7 | 1987 | NULL_TREE); |
cc8bea0a | 1988 | /* Avoid diagnosing the call again. */ |
e9e2bad7 | 1989 | suppress_warning (call, opt); |
cc8bea0a MS |
1990 | } |
1991 | ||
1992 | } /* anonymous namespace */ | |
1993 | ||
1994 | /* Attempt to detect and diagnose invalid offset bounds and (except for | |
1995 | memmove) overlapping copy in a call expression EXPR from SRC to DST | |
1996 | and DSTSIZE and SRCSIZE bytes, respectively. Both DSTSIZE and | |
213694e5 MS |
1997 | SRCSIZE may be NULL. DO_WARN is false to detect either problem |
1998 | without issue a warning. Return the OPT_Wxxx constant corresponding | |
1999 | to the warning if one has been detected and zero otherwise. */ | |
cc8bea0a | 2000 | |
e9e2bad7 | 2001 | opt_code |
8a45b051 | 2002 | check_bounds_or_overlap (gimple *call, tree dst, tree src, tree dstsize, |
213694e5 MS |
2003 | tree srcsize, bool bounds_only /* = false */, |
2004 | bool do_warn /* = true */) | |
e864d395 | 2005 | { |
30d15b51 MS |
2006 | pointer_query ptrqry (get_range_query (cfun)); |
2007 | return check_bounds_or_overlap (ptrqry, | |
e864d395 AH |
2008 | call, dst, src, dstsize, srcsize, |
2009 | bounds_only, do_warn); | |
2010 | } | |
2011 | ||
e9e2bad7 | 2012 | opt_code |
30d15b51 | 2013 | check_bounds_or_overlap (pointer_query &ptrqry, |
e864d395 AH |
2014 | gimple *call, tree dst, tree src, tree dstsize, |
2015 | tree srcsize, bool bounds_only /* = false */, | |
2016 | bool do_warn /* = true */) | |
cc8bea0a | 2017 | { |
cc8bea0a MS |
2018 | tree func = gimple_call_fndecl (call); |
2019 | ||
30d15b51 MS |
2020 | builtin_memref dstref (ptrqry, call, dst, dstsize); |
2021 | builtin_memref srcref (ptrqry, call, src, srcsize); | |
cc8bea0a | 2022 | |
6889a3ac MS |
2023 | /* Create a descriptor of the access. This may adjust both DSTREF |
2024 | and SRCREF based on one another and the kind of the access. */ | |
30d15b51 | 2025 | builtin_access acs (ptrqry, call, dstref, srcref); |
cc8bea0a MS |
2026 | |
2027 | /* Set STRICT to the value of the -Warray-bounds=N argument for | |
2028 | string functions or when N > 1. */ | |
2029 | int strict = (acs.strict () || warn_array_bounds > 1 ? warn_array_bounds : 0); | |
2030 | ||
6889a3ac MS |
2031 | /* The starting offset of the destination write access. Nonzero only |
2032 | for the strcat family of functions. */ | |
2033 | offset_int wroff = acs.write_off (dstsize); | |
2034 | ||
2035 | /* Validate offsets to each reference before the access first to make | |
2036 | sure they are within the bounds of the destination object if its | |
2037 | size is known, or PTRDIFF_MAX otherwise. */ | |
e9e2bad7 MS |
2038 | opt_code opt |
2039 | = maybe_diag_access_bounds (call, func, strict, dstref, wroff, do_warn); | |
2040 | if (opt == no_warning) | |
2041 | opt = maybe_diag_access_bounds (call, func, strict, srcref, 0, do_warn); | |
2042 | ||
2043 | if (opt != no_warning) | |
cc8bea0a | 2044 | { |
213694e5 | 2045 | if (do_warn) |
e9e2bad7 MS |
2046 | suppress_warning (call, opt); |
2047 | return opt; | |
cc8bea0a MS |
2048 | } |
2049 | ||
a411ae9b | 2050 | if (!warn_restrict || bounds_only || !src) |
e9e2bad7 | 2051 | return no_warning; |
cc8bea0a | 2052 | |
a411ae9b MS |
2053 | if (!bounds_only) |
2054 | { | |
2055 | switch (DECL_FUNCTION_CODE (func)) | |
2056 | { | |
2057 | case BUILT_IN_MEMMOVE: | |
2058 | case BUILT_IN_MEMMOVE_CHK: | |
2059 | case BUILT_IN_MEMSET: | |
2060 | case BUILT_IN_MEMSET_CHK: | |
e9e2bad7 | 2061 | return no_warning; |
a411ae9b MS |
2062 | default: |
2063 | break; | |
2064 | } | |
2065 | } | |
2066 | ||
6d3bab5d | 2067 | location_t loc = gimple_location (call); |
cc8bea0a MS |
2068 | if (operand_equal_p (dst, src, 0)) |
2069 | { | |
8cd95cec MS |
2070 | /* Issue -Wrestrict unless the pointers are null (those do |
2071 | not point to objects and so do not indicate an overlap; | |
2072 | such calls could be the result of sanitization and jump | |
2073 | threading). */ | |
e9e2bad7 | 2074 | if (!integer_zerop (dst) && !warning_suppressed_p (call, OPT_Wrestrict)) |
8cd95cec MS |
2075 | { |
2076 | warning_at (loc, OPT_Wrestrict, | |
6d3bab5d MS |
2077 | "%qD source argument is the same as destination", |
2078 | func); | |
e9e2bad7 | 2079 | suppress_warning (call, OPT_Wrestrict); |
213694e5 | 2080 | return OPT_Wrestrict; |
8cd95cec MS |
2081 | } |
2082 | ||
e9e2bad7 | 2083 | return no_warning; |
cc8bea0a MS |
2084 | } |
2085 | ||
2086 | /* Return false when overlap has been detected. */ | |
2087 | if (maybe_diag_overlap (loc, call, acs)) | |
2088 | { | |
e9e2bad7 | 2089 | suppress_warning (call, OPT_Wrestrict); |
213694e5 | 2090 | return OPT_Wrestrict; |
cc8bea0a MS |
2091 | } |
2092 | ||
e9e2bad7 | 2093 | return no_warning; |
cc8bea0a MS |
2094 | } |
2095 | ||
2096 | gimple_opt_pass * | |
2097 | make_pass_warn_restrict (gcc::context *ctxt) | |
2098 | { | |
2099 | return new pass_wrestrict (ctxt); | |
2100 | } | |
6889a3ac MS |
2101 | |
2102 | DEBUG_FUNCTION void | |
2103 | dump_builtin_memref (FILE *fp, const builtin_memref &ref) | |
2104 | { | |
2105 | fprintf (fp, "\n ptr = "); | |
2106 | print_generic_expr (fp, ref.ptr, TDF_LINENO); | |
2107 | fprintf (fp, "\n ref = "); | |
2108 | if (ref.ref) | |
2109 | print_generic_expr (fp, ref.ref, TDF_LINENO); | |
2110 | else | |
2111 | fputs ("null", fp); | |
2112 | fprintf (fp, "\n base = "); | |
2113 | print_generic_expr (fp, ref.base, TDF_LINENO); | |
2114 | fprintf (fp, | |
2115 | "\n basesize = %lli" | |
2116 | "\n refsize = %lli" | |
2117 | "\n refoff = %lli" | |
2118 | "\n offrange = [%lli, %lli]" | |
2119 | "\n sizrange = [%lli, %lli]" | |
2120 | "\n strbounded_p = %s\n", | |
2121 | (long long)ref.basesize.to_shwi (), | |
2122 | (long long)ref.refsize.to_shwi (), | |
2123 | (long long)ref.refoff.to_shwi (), | |
2124 | (long long)ref.offrange[0].to_shwi (), | |
2125 | (long long)ref.offrange[1].to_shwi (), | |
2126 | (long long)ref.sizrange[0].to_shwi (), | |
2127 | (long long)ref.sizrange[1].to_shwi (), | |
2128 | ref.strbounded_p ? "true" : "false"); | |
2129 | } | |
2130 | ||
2131 | void | |
2132 | builtin_access::dump (FILE *fp) const | |
2133 | { | |
2134 | fprintf (fp, " dstref:"); | |
2135 | dump_builtin_memref (fp, *dstref); | |
2136 | fprintf (fp, "\n srcref:"); | |
2137 | dump_builtin_memref (fp, *srcref); | |
2138 | ||
2139 | fprintf (fp, | |
2140 | " sizrange = [%lli, %lli]\n" | |
2141 | " ovloff = [%lli, %lli]\n" | |
2142 | " ovlsiz = [%lli, %lli]\n" | |
2143 | " dstoff = [%lli, %lli]\n" | |
2144 | " dstsiz = [%lli, %lli]\n" | |
2145 | " srcoff = [%lli, %lli]\n" | |
2146 | " srcsiz = [%lli, %lli]\n", | |
2147 | (long long)sizrange[0], (long long)sizrange[1], | |
2148 | (long long)ovloff[0], (long long)ovloff[1], | |
2149 | (long long)ovlsiz[0], (long long)ovlsiz[1], | |
2150 | (long long)dstoff[0].to_shwi (), (long long)dstoff[1].to_shwi (), | |
2151 | (long long)dstsiz[0].to_shwi (), (long long)dstsiz[1].to_shwi (), | |
2152 | (long long)srcoff[0].to_shwi (), (long long)srcoff[1].to_shwi (), | |
2153 | (long long)srcsiz[0].to_shwi (), (long long)srcsiz[1].to_shwi ()); | |
2154 | } | |
2155 | ||
2156 | DEBUG_FUNCTION void | |
2157 | dump_builtin_access (FILE *fp, gimple *stmt, const builtin_access &acs) | |
2158 | { | |
2159 | if (stmt) | |
2160 | { | |
2161 | fprintf (fp, "\nDumping builtin_access for "); | |
2162 | print_gimple_expr (fp, stmt, TDF_LINENO); | |
2163 | fputs (":\n", fp); | |
2164 | } | |
2165 | ||
2166 | acs.dump (fp); | |
2167 | } | |
2168 | ||
2169 | DEBUG_FUNCTION void | |
2170 | debug (gimple *stmt, const builtin_access &acs) | |
2171 | { | |
2172 | dump_builtin_access (stdout, stmt, acs); | |
2173 | } |