]>
Commit | Line | Data |
---|---|---|
8b57bfeb | 1 | /* String length optimization |
8d9254fc | 2 | Copyright (C) 2011-2020 Free Software Foundation, Inc. |
8b57bfeb JJ |
3 | Contributed by Jakub Jelinek <jakub@redhat.com> |
4 | ||
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 3, or (at your option) | |
10 | any later version. | |
11 | ||
12 | GCC is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GCC; see the file COPYING3. If not see | |
19 | <http://www.gnu.org/licenses/>. */ | |
20 | ||
21 | #include "config.h" | |
22 | #include "system.h" | |
23 | #include "coretypes.h" | |
c7131fb2 | 24 | #include "backend.h" |
957060b5 | 25 | #include "rtl.h" |
4d648807 | 26 | #include "tree.h" |
c7131fb2 | 27 | #include "gimple.h" |
957060b5 AM |
28 | #include "alloc-pool.h" |
29 | #include "tree-pass.h" | |
c7131fb2 | 30 | #include "ssa.h" |
957060b5 AM |
31 | #include "cgraph.h" |
32 | #include "gimple-pretty-print.h" | |
cc8bea0a | 33 | #include "gimple-ssa-warn-restrict.h" |
40e23961 | 34 | #include "fold-const.h" |
d8a2d370 | 35 | #include "stor-layout.h" |
2fb9a547 AM |
36 | #include "gimple-fold.h" |
37 | #include "tree-eh.h" | |
45b0be94 | 38 | #include "gimplify.h" |
5be5c238 | 39 | #include "gimple-iterator.h" |
18f429e2 | 40 | #include "gimplify-me.h" |
d8a2d370 | 41 | #include "expr.h" |
fa9544ab | 42 | #include "tree-cfg.h" |
442b4905 | 43 | #include "tree-dfa.h" |
8b57bfeb | 44 | #include "domwalk.h" |
025d57f0 | 45 | #include "tree-ssa-alias.h" |
8b57bfeb | 46 | #include "tree-ssa-propagate.h" |
5d0d5d68 | 47 | #include "tree-ssa-strlen.h" |
910ee068 | 48 | #include "tree-hash-traits.h" |
8b0b334a | 49 | #include "tree-object-size.h" |
36b85e43 | 50 | #include "builtins.h" |
e0bd6c9f | 51 | #include "target.h" |
025d57f0 MS |
52 | #include "diagnostic-core.h" |
53 | #include "diagnostic.h" | |
54 | #include "intl.h" | |
55 | #include "attribs.h" | |
6a33d0ff | 56 | #include "calls.h" |
22fca489 MS |
57 | #include "cfgloop.h" |
58 | #include "tree-ssa-loop.h" | |
59 | #include "tree-scalar-evolution.h" | |
22fca489 MS |
60 | #include "vr-values.h" |
61 | #include "gimple-ssa-evrp-analyze.h" | |
4e3d3e40 | 62 | #include "tree-ssa.h" |
8b57bfeb JJ |
63 | |
64 | /* A vector indexed by SSA_NAME_VERSION. 0 means unknown, positive value | |
65 | is an index into strinfo vector, negative value stands for | |
66 | string length of a string literal (~strlen). */ | |
9771b263 | 67 | static vec<int> ssa_ver_to_stridx; |
8b57bfeb JJ |
68 | |
69 | /* Number of currently active string indexes plus one. */ | |
70 | static int max_stridx; | |
71 | ||
22fca489 MS |
72 | /* Set to true to optimize, false when just checking. */ |
73 | static bool strlen_optimize; | |
74 | ||
8b57bfeb | 75 | /* String information record. */ |
526ceb68 | 76 | struct strinfo |
8b57bfeb | 77 | { |
e3f9a279 RS |
78 | /* Number of leading characters that are known to be nonzero. This is |
79 | also the length of the string if FULL_STRING_P. | |
80 | ||
81 | The values in a list of related string pointers must be consistent; | |
82 | that is, if strinfo B comes X bytes after strinfo A, it must be | |
83 | the case that A->nonzero_chars == X + B->nonzero_chars. */ | |
84 | tree nonzero_chars; | |
8b57bfeb JJ |
85 | /* Any of the corresponding pointers for querying alias oracle. */ |
86 | tree ptr; | |
ef29b12c | 87 | /* STMT is used for two things: |
862088aa RS |
88 | |
89 | - To record the statement that should be used for delayed length | |
90 | computations. We maintain the invariant that all related strinfos | |
91 | have delayed lengths or none do. | |
92 | ||
ef29b12c MS |
93 | - To record the malloc or calloc call that produced this result |
94 | to optimize away malloc/memset sequences. STMT is reset after | |
95 | a calloc-allocated object has been stored a non-zero value into. */ | |
355fe088 | 96 | gimple *stmt; |
ef29b12c MS |
97 | /* Set to the dynamic allocation statement for the object (alloca, |
98 | calloc, malloc, or VLA). Unlike STMT, once set for a strinfo | |
99 | object, ALLOC doesn't change. */ | |
100 | gimple *alloc; | |
8b57bfeb JJ |
101 | /* Pointer to '\0' if known, if NULL, it can be computed as |
102 | ptr + length. */ | |
103 | tree endptr; | |
104 | /* Reference count. Any changes to strinfo entry possibly shared | |
105 | with dominating basic blocks need unshare_strinfo first, except | |
106 | for dont_invalidate which affects only the immediately next | |
107 | maybe_invalidate. */ | |
108 | int refcount; | |
109 | /* Copy of index. get_strinfo (si->idx) should return si; */ | |
110 | int idx; | |
111 | /* These 3 fields are for chaining related string pointers together. | |
112 | E.g. for | |
113 | bl = strlen (b); dl = strlen (d); strcpy (a, b); c = a + bl; | |
114 | strcpy (c, d); e = c + dl; | |
115 | strinfo(a) -> strinfo(c) -> strinfo(e) | |
116 | All have ->first field equal to strinfo(a)->idx and are doubly | |
117 | chained through prev/next fields. The later strinfos are required | |
118 | to point into the same string with zero or more bytes after | |
119 | the previous pointer and all bytes in between the two pointers | |
120 | must be non-zero. Functions like strcpy or memcpy are supposed | |
121 | to adjust all previous strinfo lengths, but not following strinfo | |
122 | lengths (those are uncertain, usually invalidated during | |
123 | maybe_invalidate, except when the alias oracle knows better). | |
124 | Functions like strcat on the other side adjust the whole | |
125 | related strinfo chain. | |
126 | They are updated lazily, so to use the chain the same first fields | |
127 | and si->prev->next == si->idx needs to be verified. */ | |
128 | int first; | |
129 | int next; | |
130 | int prev; | |
131 | /* A flag whether the string is known to be written in the current | |
132 | function. */ | |
133 | bool writable; | |
134 | /* A flag for the next maybe_invalidate that this strinfo shouldn't | |
135 | be invalidated. Always cleared by maybe_invalidate. */ | |
136 | bool dont_invalidate; | |
e3f9a279 RS |
137 | /* True if the string is known to be nul-terminated after NONZERO_CHARS |
138 | characters. False is useful when detecting strings that are built | |
139 | up via successive memcpys. */ | |
140 | bool full_string_p; | |
526ceb68 | 141 | }; |
8b57bfeb JJ |
142 | |
143 | /* Pool for allocating strinfo_struct entries. */ | |
526ceb68 | 144 | static object_allocator<strinfo> strinfo_pool ("strinfo pool"); |
8b57bfeb JJ |
145 | |
146 | /* Vector mapping positive string indexes to strinfo, for the | |
147 | current basic block. The first pointer in the vector is special, | |
148 | it is either NULL, meaning the vector isn't shared, or it is | |
149 | a basic block pointer to the owner basic_block if shared. | |
150 | If some other bb wants to modify the vector, the vector needs | |
151 | to be unshared first, and only the owner bb is supposed to free it. */ | |
526ceb68 | 152 | static vec<strinfo *, va_heap, vl_embed> *stridx_to_strinfo; |
8b57bfeb JJ |
153 | |
154 | /* One OFFSET->IDX mapping. */ | |
155 | struct stridxlist | |
156 | { | |
157 | struct stridxlist *next; | |
158 | HOST_WIDE_INT offset; | |
159 | int idx; | |
160 | }; | |
161 | ||
162 | /* Hash table entry, mapping a DECL to a chain of OFFSET->IDX mappings. */ | |
163 | struct decl_stridxlist_map | |
164 | { | |
165 | struct tree_map_base base; | |
166 | struct stridxlist list; | |
167 | }; | |
168 | ||
169 | /* Hash table for mapping decls to a chained list of offset -> idx | |
170 | mappings. */ | |
22fca489 MS |
171 | typedef hash_map<tree_decl_hash, stridxlist> decl_to_stridxlist_htab_t; |
172 | static decl_to_stridxlist_htab_t *decl_to_stridxlist_htab; | |
8b57bfeb | 173 | |
9bc83f27 JJ |
174 | /* Hash table mapping strlen (or strnlen with constant bound and return |
175 | smaller than bound) calls to stridx instances describing | |
6a33d0ff MS |
176 | the calls' arguments. Non-null only when warn_stringop_truncation |
177 | is non-zero. */ | |
025d57f0 | 178 | typedef std::pair<int, location_t> stridx_strlenloc; |
6a33d0ff | 179 | static hash_map<tree, stridx_strlenloc> *strlen_to_stridx; |
025d57f0 | 180 | |
8b57bfeb JJ |
181 | /* Obstack for struct stridxlist and struct decl_stridxlist_map. */ |
182 | static struct obstack stridx_obstack; | |
183 | ||
184 | /* Last memcpy statement if it could be adjusted if the trailing | |
185 | '\0' written is immediately overwritten, or | |
186 | *x = '\0' store that could be removed if it is immediately overwritten. */ | |
187 | struct laststmt_struct | |
188 | { | |
355fe088 | 189 | gimple *stmt; |
8b57bfeb JJ |
190 | tree len; |
191 | int stridx; | |
192 | } laststmt; | |
193 | ||
e3f9a279 | 194 | static int get_stridx_plus_constant (strinfo *, unsigned HOST_WIDE_INT, tree); |
0a0de963 | 195 | static void handle_builtin_stxncpy_strncat (bool, gimple_stmt_iterator *); |
e3f9a279 | 196 | |
f7d86b5c | 197 | /* Sets MINMAX to either the constant value or the range VAL is in |
ef29b12c MS |
198 | and returns either the constant value or VAL on success or null |
199 | when the range couldn't be determined. Uses RVALS when nonnull | |
200 | to determine the range, otherwise get_range_info. */ | |
f7d86b5c | 201 | |
ef29b12c MS |
202 | tree |
203 | get_range (tree val, wide_int minmax[2], const vr_values *rvals /* = NULL */) | |
f7d86b5c | 204 | { |
ef29b12c | 205 | if (TREE_CODE (val) == INTEGER_CST) |
f7d86b5c MS |
206 | { |
207 | minmax[0] = minmax[1] = wi::to_wide (val); | |
ef29b12c | 208 | return val; |
f7d86b5c MS |
209 | } |
210 | ||
211 | if (TREE_CODE (val) != SSA_NAME) | |
ef29b12c | 212 | return NULL_TREE; |
f7d86b5c MS |
213 | |
214 | if (rvals) | |
215 | { | |
216 | /* The range below may be "inaccurate" if a constant has been | |
217 | substituted earlier for VAL by this pass that hasn't been | |
218 | propagated through the CFG. This shoud be fixed by the new | |
219 | on-demand VRP if/when it becomes available (hopefully in | |
220 | GCC 11). */ | |
221 | const value_range *vr | |
222 | = (CONST_CAST (class vr_values *, rvals)->get_value_range (val)); | |
223 | value_range_kind rng = vr->kind (); | |
224 | if (rng != VR_RANGE || !range_int_cst_p (vr)) | |
ef29b12c | 225 | return NULL_TREE; |
f7d86b5c MS |
226 | |
227 | minmax[0] = wi::to_wide (vr->min ()); | |
228 | minmax[1] = wi::to_wide (vr->max ()); | |
ef29b12c | 229 | return val; |
f7d86b5c MS |
230 | } |
231 | ||
232 | value_range_kind rng = get_range_info (val, minmax, minmax + 1); | |
233 | if (rng == VR_RANGE) | |
ef29b12c | 234 | return val; |
f7d86b5c MS |
235 | |
236 | /* Do not handle anti-ranges and instead make use of the on-demand | |
237 | VRP if/when it becomes available (hopefully in GCC 11). */ | |
ef29b12c | 238 | return NULL_TREE; |
f7d86b5c MS |
239 | } |
240 | ||
e3f9a279 RS |
241 | /* Return: |
242 | ||
27c14dbc | 243 | * +1 if SI is known to start with more than OFF nonzero characters. |
e3f9a279 | 244 | |
02c4de76 | 245 | * 0 if SI is known to start with exactly OFF nonzero characters. |
e3f9a279 | 246 | |
02c4de76 MS |
247 | * -1 if SI either does not start with OFF nonzero characters |
248 | or the relationship between the number of leading nonzero | |
249 | characters in SI and OFF is unknown. */ | |
e3f9a279 RS |
250 | |
251 | static inline int | |
252 | compare_nonzero_chars (strinfo *si, unsigned HOST_WIDE_INT off) | |
253 | { | |
254 | if (si->nonzero_chars | |
255 | && TREE_CODE (si->nonzero_chars) == INTEGER_CST) | |
256 | return compare_tree_int (si->nonzero_chars, off); | |
257 | else | |
258 | return -1; | |
259 | } | |
260 | ||
27c14dbc MS |
261 | /* Same as above but suitable also for strings with non-constant lengths. |
262 | Uses RVALS to determine length range. */ | |
263 | ||
264 | static int | |
265 | compare_nonzero_chars (strinfo *si, unsigned HOST_WIDE_INT off, | |
266 | const vr_values *rvals) | |
267 | { | |
268 | if (!si->nonzero_chars) | |
269 | return -1; | |
270 | ||
271 | if (TREE_CODE (si->nonzero_chars) == INTEGER_CST) | |
272 | return compare_tree_int (si->nonzero_chars, off); | |
273 | ||
02c4de76 | 274 | if (!rvals || TREE_CODE (si->nonzero_chars) != SSA_NAME) |
27c14dbc MS |
275 | return -1; |
276 | ||
028d81b1 | 277 | const value_range_equiv *vr |
27c14dbc MS |
278 | = (CONST_CAST (class vr_values *, rvals) |
279 | ->get_value_range (si->nonzero_chars)); | |
280 | ||
281 | value_range_kind rng = vr->kind (); | |
282 | if (rng != VR_RANGE || !range_int_cst_p (vr)) | |
283 | return -1; | |
284 | ||
02c4de76 MS |
285 | /* If the offset is less than the minimum length or if the bounds |
286 | of the length range are equal return the result of the comparison | |
287 | same as in the constant case. Otherwise return a conservative | |
288 | result. */ | |
289 | int cmpmin = compare_tree_int (vr->min (), off); | |
290 | if (cmpmin > 0 || tree_int_cst_equal (vr->min (), vr->max ())) | |
291 | return cmpmin; | |
292 | ||
293 | return -1; | |
27c14dbc MS |
294 | } |
295 | ||
e3f9a279 RS |
296 | /* Return true if SI is known to be a zero-length string. */ |
297 | ||
298 | static inline bool | |
299 | zero_length_string_p (strinfo *si) | |
300 | { | |
301 | return si->full_string_p && integer_zerop (si->nonzero_chars); | |
302 | } | |
204a913b JJ |
303 | |
304 | /* Return strinfo vector entry IDX. */ | |
305 | ||
526ceb68 | 306 | static inline strinfo * |
204a913b JJ |
307 | get_strinfo (int idx) |
308 | { | |
309 | if (vec_safe_length (stridx_to_strinfo) <= (unsigned int) idx) | |
310 | return NULL; | |
311 | return (*stridx_to_strinfo)[idx]; | |
312 | } | |
313 | ||
bde63fde RS |
314 | /* Get the next strinfo in the chain after SI, or null if none. */ |
315 | ||
316 | static inline strinfo * | |
317 | get_next_strinfo (strinfo *si) | |
318 | { | |
319 | if (si->next == 0) | |
320 | return NULL; | |
321 | strinfo *nextsi = get_strinfo (si->next); | |
322 | if (nextsi == NULL || nextsi->first != si->first || nextsi->prev != si->idx) | |
323 | return NULL; | |
324 | return nextsi; | |
325 | } | |
326 | ||
e3f9a279 RS |
327 | /* Helper function for get_stridx. Return the strinfo index of the address |
328 | of EXP, which is available in PTR if nonnull. If OFFSET_OUT, it is | |
329 | OK to return the index for some X <= &EXP and store &EXP - X in | |
e7868dc6 MS |
330 | *OFFSET_OUT. When RVALS is nonnull uses it to determine range |
331 | information. */ | |
8b57bfeb JJ |
332 | |
333 | static int | |
efe646c4 MS |
334 | get_addr_stridx (tree exp, tree ptr, unsigned HOST_WIDE_INT *offset_out, |
335 | const vr_values *rvals = NULL) | |
8b57bfeb JJ |
336 | { |
337 | HOST_WIDE_INT off; | |
5f3cd7c3 | 338 | struct stridxlist *list, *last = NULL; |
8b57bfeb JJ |
339 | tree base; |
340 | ||
c203e8a7 | 341 | if (!decl_to_stridxlist_htab) |
8b57bfeb JJ |
342 | return 0; |
343 | ||
a90c8804 RS |
344 | poly_int64 poff; |
345 | base = get_addr_base_and_unit_offset (exp, &poff); | |
346 | if (base == NULL || !DECL_P (base) || !poff.is_constant (&off)) | |
8b57bfeb JJ |
347 | return 0; |
348 | ||
1eb68d2d TS |
349 | list = decl_to_stridxlist_htab->get (base); |
350 | if (list == NULL) | |
8b57bfeb JJ |
351 | return 0; |
352 | ||
8b57bfeb JJ |
353 | do |
354 | { | |
355 | if (list->offset == off) | |
e3f9a279 RS |
356 | { |
357 | if (offset_out) | |
358 | *offset_out = 0; | |
359 | return list->idx; | |
360 | } | |
5f3cd7c3 JJ |
361 | if (list->offset > off) |
362 | return 0; | |
363 | last = list; | |
8b57bfeb JJ |
364 | list = list->next; |
365 | } | |
366 | while (list); | |
5f3cd7c3 | 367 | |
e3f9a279 | 368 | if ((offset_out || ptr) && last && last->idx > 0) |
5f3cd7c3 | 369 | { |
e3f9a279 RS |
370 | unsigned HOST_WIDE_INT rel_off |
371 | = (unsigned HOST_WIDE_INT) off - last->offset; | |
5f3cd7c3 | 372 | strinfo *si = get_strinfo (last->idx); |
efe646c4 | 373 | if (si && compare_nonzero_chars (si, rel_off, rvals) >= 0) |
e3f9a279 RS |
374 | { |
375 | if (offset_out) | |
376 | { | |
377 | *offset_out = rel_off; | |
378 | return last->idx; | |
379 | } | |
380 | else | |
381 | return get_stridx_plus_constant (si, rel_off, ptr); | |
382 | } | |
5f3cd7c3 | 383 | } |
8b57bfeb JJ |
384 | return 0; |
385 | } | |
386 | ||
f7d86b5c MS |
387 | /* Returns string index for EXP. When EXP is an SSA_NAME that refers |
388 | to a known strinfo with an offset and OFFRNG is non-null, sets | |
389 | both elements of the OFFRNG array to the range of the offset and | |
390 | returns the index of the known strinfo. In this case the result | |
ef29b12c MS |
391 | must not be used in for functions that modify the string. |
392 | When nonnull, uses RVALS to determine range information. */ | |
8b57bfeb JJ |
393 | |
394 | static int | |
ef29b12c | 395 | get_stridx (tree exp, wide_int offrng[2] = NULL, const vr_values *rvals = NULL) |
8b57bfeb | 396 | { |
f7d86b5c | 397 | if (offrng) |
ef29b12c | 398 | offrng[0] = offrng[1] = wi::zero (TYPE_PRECISION (ptrdiff_type_node)); |
f7d86b5c | 399 | |
8b57bfeb | 400 | if (TREE_CODE (exp) == SSA_NAME) |
204a913b JJ |
401 | { |
402 | if (ssa_ver_to_stridx[SSA_NAME_VERSION (exp)]) | |
403 | return ssa_ver_to_stridx[SSA_NAME_VERSION (exp)]; | |
7802a8ec | 404 | |
204a913b | 405 | tree e = exp; |
f7d86b5c | 406 | int last_idx = 0; |
7802a8ec MS |
407 | HOST_WIDE_INT offset = 0; |
408 | /* Follow a chain of at most 5 assignments. */ | |
409 | for (int i = 0; i < 5; i++) | |
204a913b | 410 | { |
355fe088 | 411 | gimple *def_stmt = SSA_NAME_DEF_STMT (e); |
7802a8ec | 412 | if (!is_gimple_assign (def_stmt)) |
f7d86b5c | 413 | return last_idx; |
7802a8ec MS |
414 | |
415 | tree_code rhs_code = gimple_assign_rhs_code (def_stmt); | |
416 | tree ptr, off; | |
417 | ||
418 | if (rhs_code == ADDR_EXPR) | |
419 | { | |
420 | /* Handle indices/offsets into VLAs which are implemented | |
421 | as pointers to arrays. */ | |
422 | ptr = gimple_assign_rhs1 (def_stmt); | |
423 | ptr = TREE_OPERAND (ptr, 0); | |
424 | ||
425 | /* Handle also VLAs of types larger than char. */ | |
426 | if (tree eltsize = TYPE_SIZE_UNIT (TREE_TYPE (ptr))) | |
427 | { | |
428 | if (TREE_CODE (ptr) == ARRAY_REF) | |
429 | { | |
430 | off = TREE_OPERAND (ptr, 1); | |
7802a8ec | 431 | ptr = TREE_OPERAND (ptr, 0); |
bc09939d MS |
432 | if (!integer_onep (eltsize)) |
433 | { | |
434 | /* Scale the array index by the size of the element | |
435 | type in the rare case that it's greater than | |
436 | the typical 1 for char, making sure both operands | |
437 | have the same type. */ | |
438 | eltsize = fold_convert (ssizetype, eltsize); | |
439 | off = fold_convert (ssizetype, off); | |
440 | off = fold_build2 (MULT_EXPR, ssizetype, off, eltsize); | |
441 | } | |
7802a8ec MS |
442 | } |
443 | else | |
444 | off = integer_zero_node; | |
445 | } | |
446 | else | |
447 | return 0; | |
448 | ||
449 | if (TREE_CODE (ptr) != MEM_REF) | |
450 | return 0; | |
451 | ||
452 | /* Add the MEM_REF byte offset. */ | |
453 | tree mem_off = TREE_OPERAND (ptr, 1); | |
454 | off = fold_build2 (PLUS_EXPR, TREE_TYPE (off), off, mem_off); | |
455 | ptr = TREE_OPERAND (ptr, 0); | |
456 | } | |
457 | else if (rhs_code == POINTER_PLUS_EXPR) | |
458 | { | |
459 | ptr = gimple_assign_rhs1 (def_stmt); | |
460 | off = gimple_assign_rhs2 (def_stmt); | |
461 | } | |
462 | else | |
204a913b | 463 | return 0; |
7802a8ec | 464 | |
f7d86b5c | 465 | if (TREE_CODE (ptr) != SSA_NAME) |
204a913b | 466 | return 0; |
f7d86b5c MS |
467 | |
468 | if (!tree_fits_shwi_p (off)) | |
469 | { | |
470 | if (int idx = ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)]) | |
471 | if (offrng) | |
472 | { | |
473 | /* Only when requested by setting OFFRNG to non-null, | |
474 | return the index corresponding to the SSA_NAME. | |
475 | Do this irrespective of the whether the offset | |
476 | is known. */ | |
ef29b12c | 477 | if (get_range (off, offrng, rvals)) |
f7d86b5c MS |
478 | { |
479 | /* When the offset range is known, increment it | |
480 | it by the constant offset computed in prior | |
481 | iterations and store it in the OFFRNG array. */ | |
482 | offrng[0] += offset; | |
483 | offrng[1] += offset; | |
484 | } | |
485 | else | |
486 | { | |
487 | /* When the offset range cannot be determined | |
488 | store [0, SIZE_MAX] and let the caller decide | |
489 | if the offset matters. */ | |
490 | offrng[1] = wi::to_wide (TYPE_MAX_VALUE (sizetype)); | |
491 | offrng[0] = wi::zero (offrng[1].get_precision ()); | |
492 | } | |
493 | return idx; | |
494 | } | |
495 | return 0; | |
496 | } | |
497 | ||
7802a8ec | 498 | HOST_WIDE_INT this_off = tree_to_shwi (off); |
f7d86b5c MS |
499 | if (offrng) |
500 | { | |
501 | offrng[0] += wi::shwi (this_off, offrng->get_precision ()); | |
502 | offrng[1] += offrng[0]; | |
503 | } | |
504 | ||
204a913b | 505 | if (this_off < 0) |
f7d86b5c MS |
506 | return last_idx; |
507 | ||
7802a8ec MS |
508 | offset = (unsigned HOST_WIDE_INT) offset + this_off; |
509 | if (offset < 0) | |
f7d86b5c MS |
510 | return last_idx; |
511 | ||
512 | if (int idx = ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)]) | |
204a913b | 513 | { |
f7d86b5c MS |
514 | strinfo *si = get_strinfo (idx); |
515 | if (si) | |
516 | { | |
517 | if (compare_nonzero_chars (si, offset) >= 0) | |
518 | return get_stridx_plus_constant (si, offset, exp); | |
519 | ||
520 | if (offrng) | |
521 | last_idx = idx; | |
522 | } | |
204a913b | 523 | } |
7802a8ec | 524 | e = ptr; |
204a913b | 525 | } |
f7d86b5c MS |
526 | |
527 | return last_idx; | |
204a913b | 528 | } |
8b57bfeb JJ |
529 | |
530 | if (TREE_CODE (exp) == ADDR_EXPR) | |
531 | { | |
e3f9a279 | 532 | int idx = get_addr_stridx (TREE_OPERAND (exp, 0), exp, NULL); |
8b57bfeb JJ |
533 | if (idx != 0) |
534 | return idx; | |
535 | } | |
536 | ||
6ab24ea8 MS |
537 | const char *p = c_getstr (exp); |
538 | if (p) | |
539 | return ~(int) strlen (p); | |
b3c3685a | 540 | |
8b57bfeb JJ |
541 | return 0; |
542 | } | |
543 | ||
544 | /* Return true if strinfo vector is shared with the immediate dominator. */ | |
545 | ||
546 | static inline bool | |
547 | strinfo_shared (void) | |
548 | { | |
9771b263 DN |
549 | return vec_safe_length (stridx_to_strinfo) |
550 | && (*stridx_to_strinfo)[0] != NULL; | |
8b57bfeb JJ |
551 | } |
552 | ||
553 | /* Unshare strinfo vector that is shared with the immediate dominator. */ | |
554 | ||
555 | static void | |
556 | unshare_strinfo_vec (void) | |
557 | { | |
526ceb68 | 558 | strinfo *si; |
8b57bfeb JJ |
559 | unsigned int i = 0; |
560 | ||
561 | gcc_assert (strinfo_shared ()); | |
9771b263 DN |
562 | stridx_to_strinfo = vec_safe_copy (stridx_to_strinfo); |
563 | for (i = 1; vec_safe_iterate (stridx_to_strinfo, i, &si); ++i) | |
8b57bfeb JJ |
564 | if (si != NULL) |
565 | si->refcount++; | |
9771b263 | 566 | (*stridx_to_strinfo)[0] = NULL; |
8b57bfeb JJ |
567 | } |
568 | ||
569 | /* Attempt to create a string index for exp, ADDR_EXPR's operand. | |
570 | Return a pointer to the location where the string index can | |
571 | be stored (if 0) or is stored, or NULL if this can't be tracked. */ | |
572 | ||
573 | static int * | |
574 | addr_stridxptr (tree exp) | |
575 | { | |
8b57bfeb JJ |
576 | HOST_WIDE_INT off; |
577 | ||
a90c8804 RS |
578 | poly_int64 poff; |
579 | tree base = get_addr_base_and_unit_offset (exp, &poff); | |
580 | if (base == NULL_TREE || !DECL_P (base) || !poff.is_constant (&off)) | |
8b57bfeb JJ |
581 | return NULL; |
582 | ||
c203e8a7 | 583 | if (!decl_to_stridxlist_htab) |
8b57bfeb | 584 | { |
1eb68d2d | 585 | decl_to_stridxlist_htab |
fb5c464a | 586 | = new hash_map<tree_decl_hash, stridxlist> (64); |
8b57bfeb JJ |
587 | gcc_obstack_init (&stridx_obstack); |
588 | } | |
1eb68d2d TS |
589 | |
590 | bool existed; | |
591 | stridxlist *list = &decl_to_stridxlist_htab->get_or_insert (base, &existed); | |
592 | if (existed) | |
8b57bfeb JJ |
593 | { |
594 | int i; | |
5f3cd7c3 JJ |
595 | stridxlist *before = NULL; |
596 | for (i = 0; i < 32; i++) | |
8b57bfeb JJ |
597 | { |
598 | if (list->offset == off) | |
599 | return &list->idx; | |
5f3cd7c3 JJ |
600 | if (list->offset > off && before == NULL) |
601 | before = list; | |
8b57bfeb JJ |
602 | if (list->next == NULL) |
603 | break; | |
5f3cd7c3 | 604 | list = list->next; |
8b57bfeb | 605 | } |
5f3cd7c3 | 606 | if (i == 32) |
8b57bfeb | 607 | return NULL; |
5f3cd7c3 JJ |
608 | if (before) |
609 | { | |
610 | list = before; | |
611 | before = XOBNEW (&stridx_obstack, struct stridxlist); | |
612 | *before = *list; | |
613 | list->next = before; | |
614 | list->offset = off; | |
615 | list->idx = 0; | |
616 | return &list->idx; | |
617 | } | |
8b57bfeb JJ |
618 | list->next = XOBNEW (&stridx_obstack, struct stridxlist); |
619 | list = list->next; | |
620 | } | |
1eb68d2d | 621 | |
8b57bfeb JJ |
622 | list->next = NULL; |
623 | list->offset = off; | |
624 | list->idx = 0; | |
625 | return &list->idx; | |
626 | } | |
627 | ||
628 | /* Create a new string index, or return 0 if reached limit. */ | |
629 | ||
630 | static int | |
631 | new_stridx (tree exp) | |
632 | { | |
633 | int idx; | |
028d4092 | 634 | if (max_stridx >= param_max_tracked_strlens) |
8b57bfeb JJ |
635 | return 0; |
636 | if (TREE_CODE (exp) == SSA_NAME) | |
637 | { | |
638 | if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (exp)) | |
639 | return 0; | |
640 | idx = max_stridx++; | |
9771b263 | 641 | ssa_ver_to_stridx[SSA_NAME_VERSION (exp)] = idx; |
8b57bfeb JJ |
642 | return idx; |
643 | } | |
644 | if (TREE_CODE (exp) == ADDR_EXPR) | |
645 | { | |
646 | int *pidx = addr_stridxptr (TREE_OPERAND (exp, 0)); | |
647 | if (pidx != NULL) | |
648 | { | |
649 | gcc_assert (*pidx == 0); | |
650 | *pidx = max_stridx++; | |
651 | return *pidx; | |
652 | } | |
653 | } | |
654 | return 0; | |
655 | } | |
656 | ||
657 | /* Like new_stridx, but for ADDR_EXPR's operand instead. */ | |
658 | ||
659 | static int | |
660 | new_addr_stridx (tree exp) | |
661 | { | |
662 | int *pidx; | |
028d4092 | 663 | if (max_stridx >= param_max_tracked_strlens) |
8b57bfeb JJ |
664 | return 0; |
665 | pidx = addr_stridxptr (exp); | |
666 | if (pidx != NULL) | |
667 | { | |
668 | gcc_assert (*pidx == 0); | |
669 | *pidx = max_stridx++; | |
670 | return *pidx; | |
671 | } | |
672 | return 0; | |
673 | } | |
674 | ||
675 | /* Create a new strinfo. */ | |
676 | ||
526ceb68 | 677 | static strinfo * |
e3f9a279 | 678 | new_strinfo (tree ptr, int idx, tree nonzero_chars, bool full_string_p) |
8b57bfeb | 679 | { |
526ceb68 | 680 | strinfo *si = strinfo_pool.allocate (); |
e3f9a279 | 681 | si->nonzero_chars = nonzero_chars; |
4e3d3e40 | 682 | STRIP_USELESS_TYPE_CONVERSION (ptr); |
8b57bfeb JJ |
683 | si->ptr = ptr; |
684 | si->stmt = NULL; | |
ef29b12c | 685 | si->alloc = NULL; |
8b57bfeb JJ |
686 | si->endptr = NULL_TREE; |
687 | si->refcount = 1; | |
688 | si->idx = idx; | |
689 | si->first = 0; | |
690 | si->prev = 0; | |
691 | si->next = 0; | |
692 | si->writable = false; | |
693 | si->dont_invalidate = false; | |
e3f9a279 | 694 | si->full_string_p = full_string_p; |
8b57bfeb JJ |
695 | return si; |
696 | } | |
697 | ||
698 | /* Decrease strinfo refcount and free it if not referenced anymore. */ | |
699 | ||
700 | static inline void | |
526ceb68 | 701 | free_strinfo (strinfo *si) |
8b57bfeb JJ |
702 | { |
703 | if (si && --si->refcount == 0) | |
33e7d32e | 704 | strinfo_pool.remove (si); |
8b57bfeb JJ |
705 | } |
706 | ||
8b57bfeb JJ |
707 | /* Set strinfo in the vector entry IDX to SI. */ |
708 | ||
709 | static inline void | |
526ceb68 | 710 | set_strinfo (int idx, strinfo *si) |
8b57bfeb | 711 | { |
9771b263 | 712 | if (vec_safe_length (stridx_to_strinfo) && (*stridx_to_strinfo)[0]) |
8b57bfeb | 713 | unshare_strinfo_vec (); |
9771b263 DN |
714 | if (vec_safe_length (stridx_to_strinfo) <= (unsigned int) idx) |
715 | vec_safe_grow_cleared (stridx_to_strinfo, idx + 1); | |
716 | (*stridx_to_strinfo)[idx] = si; | |
8b57bfeb JJ |
717 | } |
718 | ||
862088aa RS |
719 | /* Return the first strinfo in the related strinfo chain |
720 | if all strinfos in between belong to the chain, otherwise NULL. */ | |
721 | ||
722 | static strinfo * | |
723 | verify_related_strinfos (strinfo *origsi) | |
724 | { | |
725 | strinfo *si = origsi, *psi; | |
726 | ||
727 | if (origsi->first == 0) | |
728 | return NULL; | |
729 | for (; si->prev; si = psi) | |
730 | { | |
731 | if (si->first != origsi->first) | |
732 | return NULL; | |
733 | psi = get_strinfo (si->prev); | |
734 | if (psi == NULL) | |
735 | return NULL; | |
736 | if (psi->next != si->idx) | |
737 | return NULL; | |
738 | } | |
739 | if (si->idx != si->first) | |
740 | return NULL; | |
741 | return si; | |
742 | } | |
743 | ||
744 | /* Set SI's endptr to ENDPTR and compute its length based on SI->ptr. | |
745 | Use LOC for folding. */ | |
746 | ||
747 | static void | |
748 | set_endptr_and_length (location_t loc, strinfo *si, tree endptr) | |
749 | { | |
750 | si->endptr = endptr; | |
751 | si->stmt = NULL; | |
752 | tree start_as_size = fold_convert_loc (loc, size_type_node, si->ptr); | |
753 | tree end_as_size = fold_convert_loc (loc, size_type_node, endptr); | |
e3f9a279 RS |
754 | si->nonzero_chars = fold_build2_loc (loc, MINUS_EXPR, size_type_node, |
755 | end_as_size, start_as_size); | |
756 | si->full_string_p = true; | |
862088aa RS |
757 | } |
758 | ||
22fca489 MS |
759 | /* Return the string length, or NULL if it can't be computed. |
760 | The length may but need not be constant. Instead, it might be | |
761 | the result of a strlen() call. */ | |
8b57bfeb JJ |
762 | |
763 | static tree | |
526ceb68 | 764 | get_string_length (strinfo *si) |
8b57bfeb | 765 | { |
22fca489 MS |
766 | /* If the length has already been computed return it if it's exact |
767 | (i.e., the string is nul-terminated at NONZERO_CHARS), or return | |
768 | null if it isn't. */ | |
e3f9a279 RS |
769 | if (si->nonzero_chars) |
770 | return si->full_string_p ? si->nonzero_chars : NULL; | |
8b57bfeb | 771 | |
22fca489 MS |
772 | /* If the string is the result of one of the built-in calls below |
773 | attempt to compute the length from the call statement. */ | |
8b57bfeb JJ |
774 | if (si->stmt) |
775 | { | |
355fe088 | 776 | gimple *stmt = si->stmt, *lenstmt; |
83d5977e | 777 | tree callee, lhs, fn, tem; |
8b57bfeb JJ |
778 | location_t loc; |
779 | gimple_stmt_iterator gsi; | |
780 | ||
781 | gcc_assert (is_gimple_call (stmt)); | |
782 | callee = gimple_call_fndecl (stmt); | |
3d78e008 | 783 | gcc_assert (callee && fndecl_built_in_p (callee, BUILT_IN_NORMAL)); |
8b57bfeb | 784 | lhs = gimple_call_lhs (stmt); |
8b57bfeb JJ |
785 | /* unshare_strinfo is intentionally not called here. The (delayed) |
786 | transformation of strcpy or strcat into stpcpy is done at the place | |
787 | of the former strcpy/strcat call and so can affect all the strinfos | |
788 | with the same stmt. If they were unshared before and transformation | |
789 | has been already done, the handling of BUILT_IN_STPCPY{,_CHK} should | |
790 | just compute the right length. */ | |
791 | switch (DECL_FUNCTION_CODE (callee)) | |
792 | { | |
793 | case BUILT_IN_STRCAT: | |
794 | case BUILT_IN_STRCAT_CHK: | |
795 | gsi = gsi_for_stmt (stmt); | |
e79983f4 | 796 | fn = builtin_decl_implicit (BUILT_IN_STRLEN); |
8b57bfeb | 797 | gcc_assert (lhs == NULL_TREE); |
8b57bfeb | 798 | tem = unshare_expr (gimple_call_arg (stmt, 0)); |
31db0fe0 | 799 | lenstmt = gimple_build_call (fn, 1, tem); |
83d5977e | 800 | lhs = make_ssa_name (TREE_TYPE (TREE_TYPE (fn)), lenstmt); |
8b57bfeb JJ |
801 | gimple_call_set_lhs (lenstmt, lhs); |
802 | gimple_set_vuse (lenstmt, gimple_vuse (stmt)); | |
803 | gsi_insert_before (&gsi, lenstmt, GSI_SAME_STMT); | |
8b57bfeb | 804 | tem = gimple_call_arg (stmt, 0); |
33960e2e TG |
805 | if (!ptrofftype_p (TREE_TYPE (lhs))) |
806 | { | |
807 | lhs = convert_to_ptrofftype (lhs); | |
808 | lhs = force_gimple_operand_gsi (&gsi, lhs, true, NULL_TREE, | |
809 | true, GSI_SAME_STMT); | |
810 | } | |
0d0e4a03 JJ |
811 | lenstmt = gimple_build_assign |
812 | (make_ssa_name (TREE_TYPE (gimple_call_arg (stmt, 0))), | |
813 | POINTER_PLUS_EXPR,tem, lhs); | |
8b57bfeb JJ |
814 | gsi_insert_before (&gsi, lenstmt, GSI_SAME_STMT); |
815 | gimple_call_set_arg (stmt, 0, gimple_assign_lhs (lenstmt)); | |
816 | lhs = NULL_TREE; | |
817 | /* FALLTHRU */ | |
818 | case BUILT_IN_STRCPY: | |
2dcab30b | 819 | case BUILT_IN_STRCPY_CHK: |
1e762c6a | 820 | gcc_assert (builtin_decl_implicit_p (BUILT_IN_STPCPY)); |
2dcab30b ML |
821 | if (gimple_call_num_args (stmt) == 2) |
822 | fn = builtin_decl_implicit (BUILT_IN_STPCPY); | |
823 | else | |
824 | fn = builtin_decl_explicit (BUILT_IN_STPCPY_CHK); | |
8b57bfeb JJ |
825 | gcc_assert (lhs == NULL_TREE); |
826 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
827 | { | |
828 | fprintf (dump_file, "Optimizing: "); | |
829 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
830 | } | |
831 | gimple_call_set_fndecl (stmt, fn); | |
83d5977e | 832 | lhs = make_ssa_name (TREE_TYPE (TREE_TYPE (fn)), stmt); |
8b57bfeb JJ |
833 | gimple_call_set_lhs (stmt, lhs); |
834 | update_stmt (stmt); | |
835 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
836 | { | |
837 | fprintf (dump_file, "into: "); | |
838 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
839 | } | |
840 | /* FALLTHRU */ | |
841 | case BUILT_IN_STPCPY: | |
842 | case BUILT_IN_STPCPY_CHK: | |
843 | gcc_assert (lhs != NULL_TREE); | |
844 | loc = gimple_location (stmt); | |
862088aa RS |
845 | set_endptr_and_length (loc, si, lhs); |
846 | for (strinfo *chainsi = verify_related_strinfos (si); | |
847 | chainsi != NULL; | |
848 | chainsi = get_next_strinfo (chainsi)) | |
e3f9a279 | 849 | if (chainsi->nonzero_chars == NULL) |
862088aa | 850 | set_endptr_and_length (loc, chainsi, lhs); |
8b57bfeb | 851 | break; |
ef29b12c MS |
852 | case BUILT_IN_ALLOCA: |
853 | case BUILT_IN_ALLOCA_WITH_ALIGN: | |
24314386 MG |
854 | case BUILT_IN_MALLOC: |
855 | break; | |
e3f9a279 | 856 | /* BUILT_IN_CALLOC always has si->nonzero_chars set. */ |
8b57bfeb JJ |
857 | default: |
858 | gcc_unreachable (); | |
859 | break; | |
860 | } | |
861 | } | |
862 | ||
e3f9a279 | 863 | return si->nonzero_chars; |
8b57bfeb JJ |
864 | } |
865 | ||
22fca489 MS |
866 | /* Dump strlen data to FP for statement STMT. When non-null, RVALS |
867 | points to EVRP info and is used to dump strlen range for non-constant | |
868 | results. */ | |
869 | ||
870 | DEBUG_FUNCTION void | |
871 | dump_strlen_info (FILE *fp, gimple *stmt, const vr_values *rvals) | |
872 | { | |
873 | if (stmt) | |
874 | { | |
875 | fprintf (fp, "\nDumping strlen pass data after "); | |
876 | print_gimple_expr (fp, stmt, TDF_LINENO); | |
877 | fputc ('\n', fp); | |
878 | } | |
879 | else | |
880 | fprintf (fp, "\nDumping strlen pass data\n"); | |
881 | ||
882 | fprintf (fp, "max_stridx = %i\n", max_stridx); | |
883 | fprintf (fp, "ssa_ver_to_stridx has %u elements\n", | |
884 | ssa_ver_to_stridx.length ()); | |
885 | fprintf (fp, "stridx_to_strinfo"); | |
886 | if (stridx_to_strinfo) | |
887 | { | |
888 | fprintf (fp, " has %u elements\n", stridx_to_strinfo->length ()); | |
889 | for (unsigned i = 0; i != stridx_to_strinfo->length (); ++i) | |
890 | { | |
891 | if (strinfo *si = (*stridx_to_strinfo)[i]) | |
892 | { | |
893 | if (!si->idx) | |
894 | continue; | |
895 | fprintf (fp, " idx = %i", si->idx); | |
896 | if (si->ptr) | |
897 | { | |
898 | fprintf (fp, ", ptr = "); | |
899 | print_generic_expr (fp, si->ptr); | |
900 | } | |
ef29b12c MS |
901 | |
902 | if (si->nonzero_chars) | |
22fca489 | 903 | { |
ef29b12c MS |
904 | fprintf (fp, ", nonzero_chars = "); |
905 | print_generic_expr (fp, si->nonzero_chars); | |
906 | if (TREE_CODE (si->nonzero_chars) == SSA_NAME) | |
22fca489 | 907 | { |
ef29b12c MS |
908 | value_range_kind rng = VR_UNDEFINED; |
909 | wide_int min, max; | |
910 | if (rvals) | |
22fca489 | 911 | { |
ef29b12c MS |
912 | const value_range *vr |
913 | = CONST_CAST (class vr_values *, rvals) | |
914 | ->get_value_range (si->nonzero_chars); | |
915 | rng = vr->kind (); | |
916 | if (range_int_cst_p (vr)) | |
917 | { | |
918 | min = wi::to_wide (vr->min ()); | |
919 | max = wi::to_wide (vr->max ()); | |
920 | } | |
921 | else | |
922 | rng = VR_UNDEFINED; | |
22fca489 MS |
923 | } |
924 | else | |
ef29b12c | 925 | rng = get_range_info (si->nonzero_chars, &min, &max); |
22fca489 | 926 | |
ef29b12c MS |
927 | if (rng == VR_RANGE || rng == VR_ANTI_RANGE) |
928 | { | |
929 | fprintf (fp, " %s[%llu, %llu]", | |
930 | rng == VR_RANGE ? "" : "~", | |
931 | (long long) min.to_uhwi (), | |
932 | (long long) max.to_uhwi ()); | |
933 | } | |
22fca489 MS |
934 | } |
935 | } | |
ef29b12c MS |
936 | |
937 | fprintf (fp, ", refcount = %i", si->refcount); | |
22fca489 MS |
938 | if (si->stmt) |
939 | { | |
940 | fprintf (fp, ", stmt = "); | |
941 | print_gimple_expr (fp, si->stmt, 0); | |
942 | } | |
ef29b12c MS |
943 | if (si->alloc) |
944 | { | |
945 | fprintf (fp, ", alloc = "); | |
946 | print_gimple_expr (fp, si->alloc, 0); | |
947 | } | |
22fca489 MS |
948 | if (si->writable) |
949 | fprintf (fp, ", writable"); | |
ef29b12c MS |
950 | if (si->dont_invalidate) |
951 | fprintf (fp, ", dont_invalidate"); | |
22fca489 MS |
952 | if (si->full_string_p) |
953 | fprintf (fp, ", full_string_p"); | |
954 | if (strinfo *next = get_next_strinfo (si)) | |
955 | { | |
956 | fprintf (fp, ", {"); | |
957 | do | |
958 | fprintf (fp, "%i%s", next->idx, next->first ? ", " : ""); | |
959 | while ((next = get_next_strinfo (next))); | |
960 | fprintf (fp, "}"); | |
961 | } | |
962 | fputs ("\n", fp); | |
963 | } | |
964 | } | |
965 | } | |
966 | else | |
967 | fprintf (fp, " = null\n"); | |
968 | ||
969 | fprintf (fp, "decl_to_stridxlist_htab"); | |
970 | if (decl_to_stridxlist_htab) | |
971 | { | |
972 | fputs ("\n", fp); | |
973 | typedef decl_to_stridxlist_htab_t::iterator iter_t; | |
974 | for (iter_t it = decl_to_stridxlist_htab->begin (); | |
975 | it != decl_to_stridxlist_htab->end (); ++it) | |
976 | { | |
977 | tree decl = (*it).first; | |
978 | stridxlist *list = &(*it).second; | |
979 | fprintf (fp, " decl = "); | |
980 | print_generic_expr (fp, decl); | |
981 | if (list) | |
982 | { | |
983 | fprintf (fp, ", offsets = {"); | |
984 | for (; list; list = list->next) | |
985 | fprintf (fp, "%lli%s", (long long) list->offset, | |
986 | list->next ? ", " : ""); | |
987 | fputs ("}", fp); | |
988 | } | |
989 | fputs ("\n", fp); | |
990 | } | |
991 | } | |
992 | else | |
993 | fprintf (fp, " = null\n"); | |
994 | ||
995 | if (laststmt.stmt) | |
996 | { | |
997 | fprintf (fp, "laststmt = "); | |
998 | print_gimple_expr (fp, laststmt.stmt, 0); | |
999 | fprintf (fp, ", len = "); | |
1000 | print_generic_expr (fp, laststmt.len); | |
1001 | fprintf (fp, ", stridx = %i\n", laststmt.stridx); | |
1002 | } | |
1003 | } | |
1004 | ||
1005 | /* Attempt to determine the length of the string SRC. On success, store | |
1006 | the length in *PDATA and return true. Otherwise, return false. | |
1007 | VISITED is a bitmap of visited PHI nodes. RVALS points to EVRP info | |
1008 | and PSSA_DEF_MAX to an SSA_NAME assignment limit used to prevent runaway | |
1009 | recursion. */ | |
1010 | ||
1011 | static bool | |
1012 | get_range_strlen_dynamic (tree src, c_strlen_data *pdata, bitmap *visited, | |
1013 | const vr_values *rvals, unsigned *pssa_def_max) | |
1014 | { | |
1015 | int idx = get_stridx (src); | |
1016 | if (!idx) | |
1017 | { | |
1018 | if (TREE_CODE (src) == SSA_NAME) | |
1019 | { | |
1020 | gimple *def_stmt = SSA_NAME_DEF_STMT (src); | |
1021 | if (gimple_code (def_stmt) == GIMPLE_PHI) | |
1022 | { | |
1023 | if (!*visited) | |
1024 | *visited = BITMAP_ALLOC (NULL); | |
1025 | ||
1026 | if (!bitmap_set_bit (*visited, SSA_NAME_VERSION (src))) | |
1027 | return true; | |
1028 | ||
1029 | if (*pssa_def_max == 0) | |
1030 | return false; | |
1031 | ||
1032 | --*pssa_def_max; | |
1033 | ||
1034 | /* Iterate over the PHI arguments and determine the minimum | |
1035 | and maximum length/size of each and incorporate them into | |
1036 | the overall result. */ | |
1037 | gphi *phi = as_a <gphi *> (def_stmt); | |
1038 | for (unsigned i = 0; i != gimple_phi_num_args (phi); ++i) | |
1039 | { | |
1040 | tree arg = gimple_phi_arg_def (phi, i); | |
1041 | if (arg == gimple_phi_result (def_stmt)) | |
1042 | continue; | |
1043 | ||
1044 | c_strlen_data argdata = { }; | |
1045 | if (get_range_strlen_dynamic (arg, &argdata, visited, rvals, | |
1046 | pssa_def_max)) | |
1047 | { | |
1048 | /* Set the DECL of an unterminated array this argument | |
1049 | refers to if one hasn't been found yet. */ | |
1050 | if (!pdata->decl && argdata.decl) | |
1051 | pdata->decl = argdata.decl; | |
1052 | ||
1053 | if (!argdata.minlen | |
1054 | || (integer_zerop (argdata.minlen) | |
93163192 MS |
1055 | && (!argdata.maxbound |
1056 | || integer_all_onesp (argdata.maxbound)) | |
22fca489 MS |
1057 | && integer_all_onesp (argdata.maxlen))) |
1058 | { | |
1059 | /* Set the upper bound of the length to unbounded. */ | |
1060 | pdata->maxlen = build_all_ones_cst (size_type_node); | |
1061 | continue; | |
1062 | } | |
1063 | ||
1064 | /* Adjust the minimum and maximum length determined | |
1065 | so far and the upper bound on the array size. */ | |
1066 | if (!pdata->minlen | |
1067 | || tree_int_cst_lt (argdata.minlen, pdata->minlen)) | |
1068 | pdata->minlen = argdata.minlen; | |
1069 | if (!pdata->maxlen | |
93163192 MS |
1070 | || (argdata.maxlen |
1071 | && tree_int_cst_lt (pdata->maxlen, argdata.maxlen))) | |
22fca489 MS |
1072 | pdata->maxlen = argdata.maxlen; |
1073 | if (!pdata->maxbound | |
a7160771 | 1074 | || TREE_CODE (pdata->maxbound) != INTEGER_CST |
93163192 MS |
1075 | || (argdata.maxbound |
1076 | && tree_int_cst_lt (pdata->maxbound, | |
1077 | argdata.maxbound) | |
22fca489 MS |
1078 | && !integer_all_onesp (argdata.maxbound))) |
1079 | pdata->maxbound = argdata.maxbound; | |
1080 | } | |
1081 | else | |
1082 | pdata->maxlen = build_all_ones_cst (size_type_node); | |
1083 | } | |
1084 | ||
1085 | return true; | |
1086 | } | |
1087 | } | |
1088 | ||
1089 | /* Return success regardless of the result and handle *PDATA | |
1090 | in the caller. */ | |
1091 | get_range_strlen (src, pdata, 1); | |
1092 | return true; | |
1093 | } | |
1094 | ||
1095 | if (idx < 0) | |
1096 | { | |
1097 | /* SRC is a string of constant length. */ | |
1098 | pdata->minlen = build_int_cst (size_type_node, ~idx); | |
1099 | pdata->maxlen = pdata->minlen; | |
1100 | pdata->maxbound = pdata->maxlen; | |
1101 | return true; | |
1102 | } | |
1103 | ||
1104 | if (strinfo *si = get_strinfo (idx)) | |
1105 | { | |
1106 | pdata->minlen = get_string_length (si); | |
93163192 | 1107 | if (!pdata->minlen && si->nonzero_chars) |
22fca489 MS |
1108 | { |
1109 | if (TREE_CODE (si->nonzero_chars) == INTEGER_CST) | |
1110 | pdata->minlen = si->nonzero_chars; | |
1111 | else if (TREE_CODE (si->nonzero_chars) == SSA_NAME) | |
1112 | { | |
028d81b1 | 1113 | const value_range_equiv *vr |
22fca489 MS |
1114 | = CONST_CAST (class vr_values *, rvals) |
1115 | ->get_value_range (si->nonzero_chars); | |
1116 | if (vr->kind () == VR_RANGE | |
1117 | && range_int_cst_p (vr)) | |
1118 | { | |
1119 | pdata->minlen = vr->min (); | |
1120 | pdata->maxlen = vr->max (); | |
1121 | } | |
1122 | else | |
1123 | pdata->minlen = build_zero_cst (size_type_node); | |
1124 | } | |
1125 | else | |
1126 | pdata->minlen = build_zero_cst (size_type_node); | |
1127 | ||
1128 | tree base = si->ptr; | |
1129 | if (TREE_CODE (base) == ADDR_EXPR) | |
1130 | base = TREE_OPERAND (base, 0); | |
1131 | ||
1132 | HOST_WIDE_INT off; | |
1133 | poly_int64 poff; | |
1134 | base = get_addr_base_and_unit_offset (base, &poff); | |
1135 | if (base | |
1136 | && DECL_P (base) | |
1137 | && TREE_CODE (TREE_TYPE (base)) == ARRAY_TYPE | |
1138 | && TYPE_SIZE_UNIT (TREE_TYPE (base)) | |
1139 | && poff.is_constant (&off)) | |
1140 | { | |
1141 | tree basetype = TREE_TYPE (base); | |
1142 | tree size = TYPE_SIZE_UNIT (basetype); | |
05c13c43 MS |
1143 | if (TREE_CODE (size) == INTEGER_CST) |
1144 | { | |
1145 | ++off; /* Increment for the terminating nul. */ | |
1146 | tree toffset = build_int_cst (size_type_node, off); | |
1147 | pdata->maxlen = fold_build2 (MINUS_EXPR, size_type_node, size, | |
1148 | toffset); | |
1149 | pdata->maxbound = pdata->maxlen; | |
1150 | } | |
1151 | else | |
1152 | pdata->maxlen = build_all_ones_cst (size_type_node); | |
22fca489 MS |
1153 | } |
1154 | else | |
1155 | pdata->maxlen = build_all_ones_cst (size_type_node); | |
1156 | } | |
93163192 | 1157 | else if (pdata->minlen && TREE_CODE (pdata->minlen) == SSA_NAME) |
22fca489 | 1158 | { |
028d81b1 | 1159 | const value_range_equiv *vr |
22fca489 MS |
1160 | = CONST_CAST (class vr_values *, rvals) |
1161 | ->get_value_range (si->nonzero_chars); | |
1162 | if (vr->kind () == VR_RANGE | |
1163 | && range_int_cst_p (vr)) | |
1164 | { | |
1165 | pdata->minlen = vr->min (); | |
1166 | pdata->maxlen = vr->max (); | |
1167 | pdata->maxbound = pdata->maxlen; | |
1168 | } | |
1169 | else | |
1170 | { | |
1171 | pdata->minlen = build_zero_cst (size_type_node); | |
1172 | pdata->maxlen = build_all_ones_cst (size_type_node); | |
1173 | } | |
1174 | } | |
93163192 | 1175 | else if (pdata->minlen && TREE_CODE (pdata->minlen) == INTEGER_CST) |
22fca489 MS |
1176 | { |
1177 | pdata->maxlen = pdata->minlen; | |
1178 | pdata->maxbound = pdata->minlen; | |
1179 | } | |
93163192 MS |
1180 | else |
1181 | { | |
1182 | /* For PDATA->MINLEN that's a non-constant expression such | |
1183 | as PLUS_EXPR whose value range is unknown, set the bounds | |
1184 | to zero and SIZE_MAX. */ | |
1185 | pdata->minlen = build_zero_cst (size_type_node); | |
1186 | pdata->maxlen = build_all_ones_cst (size_type_node); | |
1187 | } | |
22fca489 MS |
1188 | |
1189 | return true; | |
1190 | } | |
1191 | ||
1192 | return false; | |
1193 | } | |
1194 | ||
1195 | /* Analogous to get_range_strlen but for dynamically created strings, | |
1196 | i.e., those created by calls to strcpy as opposed to just string | |
1197 | constants. | |
1198 | Try to obtain the range of the lengths of the string(s) referenced | |
1199 | by SRC, or the size of the largest array SRC refers to if the range | |
1200 | of lengths cannot be determined, and store all in *PDATA. RVALS | |
1201 | points to EVRP info. */ | |
1202 | ||
1203 | void | |
1204 | get_range_strlen_dynamic (tree src, c_strlen_data *pdata, | |
1205 | const vr_values *rvals) | |
1206 | { | |
1207 | bitmap visited = NULL; | |
a7160771 | 1208 | tree maxbound = pdata->maxbound; |
22fca489 | 1209 | |
028d4092 | 1210 | unsigned limit = param_ssa_name_def_chain_limit; |
22fca489 MS |
1211 | if (!get_range_strlen_dynamic (src, pdata, &visited, rvals, &limit)) |
1212 | { | |
1213 | /* On failure extend the length range to an impossible maximum | |
1214 | (a valid MAXLEN must be less than PTRDIFF_MAX - 1). Other | |
1215 | members can stay unchanged regardless. */ | |
1216 | pdata->minlen = ssize_int (0); | |
1217 | pdata->maxlen = build_all_ones_cst (size_type_node); | |
1218 | } | |
1219 | else if (!pdata->minlen) | |
1220 | pdata->minlen = ssize_int (0); | |
1221 | ||
a7160771 MS |
1222 | /* If it's unchanged from it initial non-null value, set the conservative |
1223 | MAXBOUND to SIZE_MAX. Otherwise leave it null (if it is null). */ | |
1224 | if (maxbound && pdata->maxbound == maxbound) | |
1225 | pdata->maxbound = build_all_ones_cst (size_type_node); | |
1226 | ||
22fca489 MS |
1227 | if (visited) |
1228 | BITMAP_FREE (visited); | |
1229 | } | |
1230 | ||
ef29b12c MS |
1231 | /* Invalidate string length information for strings whose length might |
1232 | change due to stores in STMT, except those marked DONT_INVALIDATE. | |
1233 | For string-modifying statements, ZERO_WRITE is set when the statement | |
1234 | wrote only zeros. | |
1235 | Returns true if any STRIDX_TO_STRINFO entries were considered | |
1236 | for invalidation. */ | |
8b57bfeb JJ |
1237 | |
1238 | static bool | |
2fcb55d1 | 1239 | maybe_invalidate (gimple *stmt, bool zero_write = false) |
8b57bfeb | 1240 | { |
2fcb55d1 | 1241 | if (dump_file && (dump_flags & TDF_DETAILS)) |
ef29b12c MS |
1242 | { |
1243 | fprintf (dump_file, "%s called for ", __func__); | |
1244 | print_gimple_stmt (dump_file, stmt, TDF_LINENO); | |
1245 | } | |
2fcb55d1 | 1246 | |
526ceb68 | 1247 | strinfo *si; |
8b57bfeb JJ |
1248 | bool nonempty = false; |
1249 | ||
ef29b12c MS |
1250 | for (unsigned i = 1; vec_safe_iterate (stridx_to_strinfo, i, &si); ++i) |
1251 | { | |
1252 | if (si == NULL || !POINTER_TYPE_P (TREE_TYPE (si->ptr))) | |
1253 | continue; | |
2fcb55d1 | 1254 | |
ef29b12c | 1255 | nonempty = true; |
2fcb55d1 | 1256 | |
ef29b12c MS |
1257 | /* Unconditionally reset DONT_INVALIDATE. */ |
1258 | bool dont_invalidate = si->dont_invalidate; | |
1259 | si->dont_invalidate = false; | |
1260 | ||
1261 | if (dont_invalidate) | |
1262 | continue; | |
1263 | ||
1264 | ao_ref r; | |
1265 | tree size = NULL_TREE; | |
1266 | if (si->nonzero_chars) | |
1267 | { | |
1268 | /* Include the terminating nul in the size of the string | |
1269 | to consider when determining possible clobber. */ | |
1270 | tree type = TREE_TYPE (si->nonzero_chars); | |
1271 | size = fold_build2 (PLUS_EXPR, type, si->nonzero_chars, | |
1272 | build_int_cst (type, 1)); | |
1273 | } | |
1274 | ao_ref_init_from_ptr_and_size (&r, si->ptr, size); | |
1275 | if (stmt_may_clobber_ref_p_1 (stmt, &r)) | |
1276 | { | |
1277 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1278 | { | |
1279 | fputs (" statement may clobber object ", dump_file); | |
1280 | print_generic_expr (dump_file, si->ptr); | |
1281 | if (size && tree_fits_uhwi_p (size)) | |
1282 | fprintf (dump_file, " " HOST_WIDE_INT_PRINT_UNSIGNED | |
1283 | " bytes in size", tree_to_uhwi (size)); | |
1284 | fputc ('\n', dump_file); | |
1285 | } | |
1286 | ||
1287 | set_strinfo (i, NULL); | |
1288 | free_strinfo (si); | |
1289 | continue; | |
1290 | } | |
1291 | ||
1292 | if (size | |
1293 | && !zero_write | |
1294 | && si->stmt | |
1295 | && is_gimple_call (si->stmt) | |
1296 | && (DECL_FUNCTION_CODE (gimple_call_fndecl (si->stmt)) | |
1297 | == BUILT_IN_CALLOC)) | |
1298 | { | |
1299 | /* If the clobber test above considered the length of | |
1300 | the string (including the nul), then for (potentially) | |
1301 | non-zero writes that might modify storage allocated by | |
1302 | calloc consider the whole object and if it might be | |
1303 | clobbered by the statement reset the statement. */ | |
1304 | ao_ref_init_from_ptr_and_size (&r, si->ptr, NULL_TREE); | |
1305 | if (stmt_may_clobber_ref_p_1 (stmt, &r)) | |
1306 | si->stmt = NULL; | |
1307 | } | |
1308 | } | |
2fcb55d1 MS |
1309 | |
1310 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
ef29b12c | 1311 | fprintf (dump_file, "%s returns %i\n", __func__, nonempty); |
2fcb55d1 | 1312 | |
8b57bfeb JJ |
1313 | return nonempty; |
1314 | } | |
1315 | ||
204a913b | 1316 | /* Unshare strinfo record SI, if it has refcount > 1 or |
8b57bfeb JJ |
1317 | if stridx_to_strinfo vector is shared with some other |
1318 | bbs. */ | |
1319 | ||
526ceb68 TS |
1320 | static strinfo * |
1321 | unshare_strinfo (strinfo *si) | |
8b57bfeb | 1322 | { |
526ceb68 | 1323 | strinfo *nsi; |
8b57bfeb JJ |
1324 | |
1325 | if (si->refcount == 1 && !strinfo_shared ()) | |
1326 | return si; | |
1327 | ||
e3f9a279 | 1328 | nsi = new_strinfo (si->ptr, si->idx, si->nonzero_chars, si->full_string_p); |
8b57bfeb | 1329 | nsi->stmt = si->stmt; |
ef29b12c | 1330 | nsi->alloc = si->alloc; |
8b57bfeb JJ |
1331 | nsi->endptr = si->endptr; |
1332 | nsi->first = si->first; | |
1333 | nsi->prev = si->prev; | |
1334 | nsi->next = si->next; | |
1335 | nsi->writable = si->writable; | |
1336 | set_strinfo (si->idx, nsi); | |
1337 | free_strinfo (si); | |
1338 | return nsi; | |
1339 | } | |
1340 | ||
204a913b JJ |
1341 | /* Attempt to create a new strinfo for BASESI + OFF, or find existing |
1342 | strinfo if there is any. Return it's idx, or 0 if no strinfo has | |
1343 | been created. */ | |
1344 | ||
1345 | static int | |
e3f9a279 RS |
1346 | get_stridx_plus_constant (strinfo *basesi, unsigned HOST_WIDE_INT off, |
1347 | tree ptr) | |
204a913b | 1348 | { |
5f3cd7c3 | 1349 | if (TREE_CODE (ptr) == SSA_NAME && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ptr)) |
204a913b JJ |
1350 | return 0; |
1351 | ||
e3f9a279 RS |
1352 | if (compare_nonzero_chars (basesi, off) < 0 |
1353 | || !tree_fits_uhwi_p (basesi->nonzero_chars)) | |
204a913b JJ |
1354 | return 0; |
1355 | ||
e3f9a279 RS |
1356 | unsigned HOST_WIDE_INT nonzero_chars |
1357 | = tree_to_uhwi (basesi->nonzero_chars) - off; | |
526ceb68 | 1358 | strinfo *si = basesi, *chainsi; |
204a913b JJ |
1359 | if (si->first || si->prev || si->next) |
1360 | si = verify_related_strinfos (basesi); | |
1361 | if (si == NULL | |
e3f9a279 RS |
1362 | || si->nonzero_chars == NULL_TREE |
1363 | || TREE_CODE (si->nonzero_chars) != INTEGER_CST) | |
204a913b JJ |
1364 | return 0; |
1365 | ||
5f3cd7c3 JJ |
1366 | if (TREE_CODE (ptr) == SSA_NAME |
1367 | && ssa_ver_to_stridx.length () <= SSA_NAME_VERSION (ptr)) | |
204a913b JJ |
1368 | ssa_ver_to_stridx.safe_grow_cleared (num_ssa_names); |
1369 | ||
e3f9a279 | 1370 | gcc_checking_assert (compare_tree_int (si->nonzero_chars, off) != -1); |
204a913b JJ |
1371 | for (chainsi = si; chainsi->next; chainsi = si) |
1372 | { | |
bde63fde | 1373 | si = get_next_strinfo (chainsi); |
204a913b | 1374 | if (si == NULL |
e3f9a279 RS |
1375 | || si->nonzero_chars == NULL_TREE |
1376 | || TREE_CODE (si->nonzero_chars) != INTEGER_CST) | |
204a913b | 1377 | break; |
e3f9a279 | 1378 | int r = compare_tree_int (si->nonzero_chars, nonzero_chars); |
204a913b JJ |
1379 | if (r != 1) |
1380 | { | |
1381 | if (r == 0) | |
1382 | { | |
55a0f21a JJ |
1383 | if (TREE_CODE (ptr) == SSA_NAME) |
1384 | ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)] = si->idx; | |
1385 | else | |
1386 | { | |
1387 | int *pidx = addr_stridxptr (TREE_OPERAND (ptr, 0)); | |
1388 | if (pidx != NULL && *pidx == 0) | |
1389 | *pidx = si->idx; | |
1390 | } | |
204a913b JJ |
1391 | return si->idx; |
1392 | } | |
1393 | break; | |
1394 | } | |
1395 | } | |
1396 | ||
1397 | int idx = new_stridx (ptr); | |
1398 | if (idx == 0) | |
1399 | return 0; | |
e3f9a279 RS |
1400 | si = new_strinfo (ptr, idx, build_int_cst (size_type_node, nonzero_chars), |
1401 | basesi->full_string_p); | |
204a913b | 1402 | set_strinfo (idx, si); |
9c8c7338 | 1403 | if (strinfo *nextsi = get_strinfo (chainsi->next)) |
204a913b | 1404 | { |
9c8c7338 | 1405 | nextsi = unshare_strinfo (nextsi); |
204a913b JJ |
1406 | si->next = nextsi->idx; |
1407 | nextsi->prev = idx; | |
1408 | } | |
1409 | chainsi = unshare_strinfo (chainsi); | |
1410 | if (chainsi->first == 0) | |
1411 | chainsi->first = chainsi->idx; | |
1412 | chainsi->next = idx; | |
e3f9a279 | 1413 | if (chainsi->endptr == NULL_TREE && zero_length_string_p (si)) |
204a913b JJ |
1414 | chainsi->endptr = ptr; |
1415 | si->endptr = chainsi->endptr; | |
1416 | si->prev = chainsi->idx; | |
1417 | si->first = chainsi->first; | |
1418 | si->writable = chainsi->writable; | |
1419 | return si->idx; | |
1420 | } | |
1421 | ||
8b57bfeb JJ |
1422 | /* Note that PTR, a pointer SSA_NAME initialized in the current stmt, points |
1423 | to a zero-length string and if possible chain it to a related strinfo | |
1424 | chain whose part is or might be CHAINSI. */ | |
1425 | ||
526ceb68 TS |
1426 | static strinfo * |
1427 | zero_length_string (tree ptr, strinfo *chainsi) | |
8b57bfeb | 1428 | { |
526ceb68 | 1429 | strinfo *si; |
8b57bfeb | 1430 | int idx; |
204a913b JJ |
1431 | if (ssa_ver_to_stridx.length () <= SSA_NAME_VERSION (ptr)) |
1432 | ssa_ver_to_stridx.safe_grow_cleared (num_ssa_names); | |
8b57bfeb | 1433 | gcc_checking_assert (TREE_CODE (ptr) == SSA_NAME |
204a913b | 1434 | && ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)] == 0); |
8b57bfeb JJ |
1435 | |
1436 | if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ptr)) | |
1437 | return NULL; | |
1438 | if (chainsi != NULL) | |
1439 | { | |
1440 | si = verify_related_strinfos (chainsi); | |
1441 | if (si) | |
1442 | { | |
bde63fde | 1443 | do |
8b57bfeb | 1444 | { |
862088aa | 1445 | /* We shouldn't mix delayed and non-delayed lengths. */ |
e3f9a279 | 1446 | gcc_assert (si->full_string_p); |
bde63fde | 1447 | if (si->endptr == NULL_TREE) |
8b57bfeb | 1448 | { |
bde63fde RS |
1449 | si = unshare_strinfo (si); |
1450 | si->endptr = ptr; | |
8b57bfeb | 1451 | } |
bde63fde RS |
1452 | chainsi = si; |
1453 | si = get_next_strinfo (si); | |
8b57bfeb | 1454 | } |
bde63fde | 1455 | while (si != NULL); |
e3f9a279 | 1456 | if (zero_length_string_p (chainsi)) |
8b57bfeb JJ |
1457 | { |
1458 | if (chainsi->next) | |
1459 | { | |
1460 | chainsi = unshare_strinfo (chainsi); | |
1461 | chainsi->next = 0; | |
1462 | } | |
9771b263 | 1463 | ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)] = chainsi->idx; |
8b57bfeb JJ |
1464 | return chainsi; |
1465 | } | |
1466 | } | |
862088aa | 1467 | else |
8b57bfeb | 1468 | { |
862088aa | 1469 | /* We shouldn't mix delayed and non-delayed lengths. */ |
e3f9a279 | 1470 | gcc_assert (chainsi->full_string_p); |
862088aa RS |
1471 | if (chainsi->first || chainsi->prev || chainsi->next) |
1472 | { | |
1473 | chainsi = unshare_strinfo (chainsi); | |
1474 | chainsi->first = 0; | |
1475 | chainsi->prev = 0; | |
1476 | chainsi->next = 0; | |
1477 | } | |
8b57bfeb JJ |
1478 | } |
1479 | } | |
1480 | idx = new_stridx (ptr); | |
1481 | if (idx == 0) | |
1482 | return NULL; | |
e3f9a279 | 1483 | si = new_strinfo (ptr, idx, build_int_cst (size_type_node, 0), true); |
8b57bfeb JJ |
1484 | set_strinfo (idx, si); |
1485 | si->endptr = ptr; | |
1486 | if (chainsi != NULL) | |
1487 | { | |
1488 | chainsi = unshare_strinfo (chainsi); | |
1489 | if (chainsi->first == 0) | |
1490 | chainsi->first = chainsi->idx; | |
1491 | chainsi->next = idx; | |
93a90db6 AK |
1492 | if (chainsi->endptr == NULL_TREE) |
1493 | chainsi->endptr = ptr; | |
8b57bfeb JJ |
1494 | si->prev = chainsi->idx; |
1495 | si->first = chainsi->first; | |
1496 | si->writable = chainsi->writable; | |
1497 | } | |
1498 | return si; | |
1499 | } | |
1500 | ||
e3f9a279 RS |
1501 | /* For strinfo ORIGSI whose length has been just updated, adjust other |
1502 | related strinfos so that they match the new ORIGSI. This involves: | |
1503 | ||
1504 | - adding ADJ to the nonzero_chars fields | |
1505 | - copying full_string_p from the new ORIGSI. */ | |
8b57bfeb JJ |
1506 | |
1507 | static void | |
526ceb68 | 1508 | adjust_related_strinfos (location_t loc, strinfo *origsi, tree adj) |
8b57bfeb | 1509 | { |
526ceb68 | 1510 | strinfo *si = verify_related_strinfos (origsi); |
8b57bfeb JJ |
1511 | |
1512 | if (si == NULL) | |
1513 | return; | |
1514 | ||
1515 | while (1) | |
1516 | { | |
526ceb68 | 1517 | strinfo *nsi; |
8b57bfeb JJ |
1518 | |
1519 | if (si != origsi) | |
1520 | { | |
1521 | tree tem; | |
1522 | ||
1523 | si = unshare_strinfo (si); | |
21722777 MS |
1524 | /* We shouldn't see delayed lengths here; the caller must |
1525 | have calculated the old length in order to calculate | |
1526 | the adjustment. */ | |
e3f9a279 RS |
1527 | gcc_assert (si->nonzero_chars); |
1528 | tem = fold_convert_loc (loc, TREE_TYPE (si->nonzero_chars), adj); | |
1529 | si->nonzero_chars = fold_build2_loc (loc, PLUS_EXPR, | |
1530 | TREE_TYPE (si->nonzero_chars), | |
1531 | si->nonzero_chars, tem); | |
1532 | si->full_string_p = origsi->full_string_p; | |
93a90db6 | 1533 | |
8b57bfeb JJ |
1534 | si->endptr = NULL_TREE; |
1535 | si->dont_invalidate = true; | |
1536 | } | |
bde63fde RS |
1537 | nsi = get_next_strinfo (si); |
1538 | if (nsi == NULL) | |
8b57bfeb JJ |
1539 | return; |
1540 | si = nsi; | |
1541 | } | |
1542 | } | |
1543 | ||
1544 | /* Find if there are other SSA_NAME pointers equal to PTR | |
1545 | for which we don't track their string lengths yet. If so, use | |
1546 | IDX for them. */ | |
1547 | ||
1548 | static void | |
1549 | find_equal_ptrs (tree ptr, int idx) | |
1550 | { | |
1551 | if (TREE_CODE (ptr) != SSA_NAME) | |
1552 | return; | |
1553 | while (1) | |
1554 | { | |
355fe088 | 1555 | gimple *stmt = SSA_NAME_DEF_STMT (ptr); |
8b57bfeb JJ |
1556 | if (!is_gimple_assign (stmt)) |
1557 | return; | |
1558 | ptr = gimple_assign_rhs1 (stmt); | |
1559 | switch (gimple_assign_rhs_code (stmt)) | |
1560 | { | |
1561 | case SSA_NAME: | |
1562 | break; | |
97246d78 JJ |
1563 | CASE_CONVERT: |
1564 | if (!POINTER_TYPE_P (TREE_TYPE (ptr))) | |
1565 | return; | |
1566 | if (TREE_CODE (ptr) == SSA_NAME) | |
1567 | break; | |
1568 | if (TREE_CODE (ptr) != ADDR_EXPR) | |
1569 | return; | |
1570 | /* FALLTHRU */ | |
8b57bfeb JJ |
1571 | case ADDR_EXPR: |
1572 | { | |
1573 | int *pidx = addr_stridxptr (TREE_OPERAND (ptr, 0)); | |
1574 | if (pidx != NULL && *pidx == 0) | |
1575 | *pidx = idx; | |
1576 | return; | |
1577 | } | |
8b57bfeb JJ |
1578 | default: |
1579 | return; | |
1580 | } | |
1581 | ||
1582 | /* We might find an endptr created in this pass. Grow the | |
1583 | vector in that case. */ | |
9771b263 DN |
1584 | if (ssa_ver_to_stridx.length () <= SSA_NAME_VERSION (ptr)) |
1585 | ssa_ver_to_stridx.safe_grow_cleared (num_ssa_names); | |
8b57bfeb | 1586 | |
9771b263 | 1587 | if (ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)] != 0) |
8b57bfeb | 1588 | return; |
9771b263 | 1589 | ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)] = idx; |
8b57bfeb JJ |
1590 | } |
1591 | } | |
1592 | ||
0ad84f34 JJ |
1593 | /* Return true if STMT is a call to a builtin function with the right |
1594 | arguments and attributes that should be considered for optimization | |
1595 | by this pass. */ | |
1596 | ||
1597 | static bool | |
1598 | valid_builtin_call (gimple *stmt) | |
1599 | { | |
1600 | if (!gimple_call_builtin_p (stmt, BUILT_IN_NORMAL)) | |
1601 | return false; | |
1602 | ||
1603 | tree callee = gimple_call_fndecl (stmt); | |
f54e63df JJ |
1604 | tree decl = builtin_decl_explicit (DECL_FUNCTION_CODE (callee)); |
1605 | if (decl | |
1606 | && decl != callee | |
1607 | && !gimple_builtin_call_types_compatible_p (stmt, decl)) | |
1608 | return false; | |
1609 | ||
0ad84f34 JJ |
1610 | switch (DECL_FUNCTION_CODE (callee)) |
1611 | { | |
1612 | case BUILT_IN_MEMCMP: | |
1613 | case BUILT_IN_MEMCMP_EQ: | |
f54e63df JJ |
1614 | case BUILT_IN_STRCMP: |
1615 | case BUILT_IN_STRNCMP: | |
0ad84f34 | 1616 | case BUILT_IN_STRCHR: |
0ad84f34 | 1617 | case BUILT_IN_STRLEN: |
f54e63df | 1618 | case BUILT_IN_STRNLEN: |
0ad84f34 JJ |
1619 | /* The above functions should be pure. Punt if they aren't. */ |
1620 | if (gimple_vdef (stmt) || gimple_vuse (stmt) == NULL_TREE) | |
1621 | return false; | |
1622 | break; | |
1623 | ||
ef29b12c MS |
1624 | case BUILT_IN_ALLOCA: |
1625 | case BUILT_IN_ALLOCA_WITH_ALIGN: | |
0ad84f34 JJ |
1626 | case BUILT_IN_CALLOC: |
1627 | case BUILT_IN_MALLOC: | |
1628 | case BUILT_IN_MEMCPY: | |
1629 | case BUILT_IN_MEMCPY_CHK: | |
0ad84f34 JJ |
1630 | case BUILT_IN_MEMPCPY: |
1631 | case BUILT_IN_MEMPCPY_CHK: | |
0ad84f34 JJ |
1632 | case BUILT_IN_MEMSET: |
1633 | case BUILT_IN_STPCPY: | |
1634 | case BUILT_IN_STPCPY_CHK: | |
f54e63df JJ |
1635 | case BUILT_IN_STPNCPY: |
1636 | case BUILT_IN_STPNCPY_CHK: | |
0ad84f34 JJ |
1637 | case BUILT_IN_STRCAT: |
1638 | case BUILT_IN_STRCAT_CHK: | |
0ad84f34 JJ |
1639 | case BUILT_IN_STRCPY: |
1640 | case BUILT_IN_STRCPY_CHK: | |
f54e63df JJ |
1641 | case BUILT_IN_STRNCAT: |
1642 | case BUILT_IN_STRNCAT_CHK: | |
1643 | case BUILT_IN_STRNCPY: | |
1644 | case BUILT_IN_STRNCPY_CHK: | |
0ad84f34 JJ |
1645 | /* The above functions should be neither const nor pure. Punt if they |
1646 | aren't. */ | |
1647 | if (gimple_vdef (stmt) == NULL_TREE || gimple_vuse (stmt) == NULL_TREE) | |
1648 | return false; | |
1649 | break; | |
1650 | ||
1651 | default: | |
1652 | break; | |
1653 | } | |
1654 | ||
1655 | return true; | |
1656 | } | |
1657 | ||
8b57bfeb JJ |
1658 | /* If the last .MEM setter statement before STMT is |
1659 | memcpy (x, y, strlen (y) + 1), the only .MEM use of it is STMT | |
1660 | and STMT is known to overwrite x[strlen (x)], adjust the last memcpy to | |
1661 | just memcpy (x, y, strlen (y)). SI must be the zero length | |
1662 | strinfo. */ | |
1663 | ||
1664 | static void | |
526ceb68 | 1665 | adjust_last_stmt (strinfo *si, gimple *stmt, bool is_strcat) |
8b57bfeb JJ |
1666 | { |
1667 | tree vuse, callee, len; | |
1668 | struct laststmt_struct last = laststmt; | |
526ceb68 | 1669 | strinfo *lastsi, *firstsi; |
f5fc4a04 | 1670 | unsigned len_arg_no = 2; |
8b57bfeb JJ |
1671 | |
1672 | laststmt.stmt = NULL; | |
1673 | laststmt.len = NULL_TREE; | |
1674 | laststmt.stridx = 0; | |
1675 | ||
1676 | if (last.stmt == NULL) | |
1677 | return; | |
1678 | ||
1679 | vuse = gimple_vuse (stmt); | |
1680 | if (vuse == NULL_TREE | |
1681 | || SSA_NAME_DEF_STMT (vuse) != last.stmt | |
1682 | || !has_single_use (vuse)) | |
1683 | return; | |
1684 | ||
1685 | gcc_assert (last.stridx > 0); | |
1686 | lastsi = get_strinfo (last.stridx); | |
1687 | if (lastsi == NULL) | |
1688 | return; | |
1689 | ||
1690 | if (lastsi != si) | |
1691 | { | |
1692 | if (lastsi->first == 0 || lastsi->first != si->first) | |
1693 | return; | |
1694 | ||
1695 | firstsi = verify_related_strinfos (si); | |
1696 | if (firstsi == NULL) | |
1697 | return; | |
1698 | while (firstsi != lastsi) | |
1699 | { | |
bde63fde RS |
1700 | firstsi = get_next_strinfo (firstsi); |
1701 | if (firstsi == NULL) | |
8b57bfeb | 1702 | return; |
8b57bfeb JJ |
1703 | } |
1704 | } | |
1705 | ||
e3f9a279 RS |
1706 | if (!is_strcat && !zero_length_string_p (si)) |
1707 | return; | |
8b57bfeb JJ |
1708 | |
1709 | if (is_gimple_assign (last.stmt)) | |
1710 | { | |
1711 | gimple_stmt_iterator gsi; | |
1712 | ||
1713 | if (!integer_zerop (gimple_assign_rhs1 (last.stmt))) | |
1714 | return; | |
36bbc05d | 1715 | if (stmt_could_throw_p (cfun, last.stmt)) |
8b57bfeb JJ |
1716 | return; |
1717 | gsi = gsi_for_stmt (last.stmt); | |
1718 | unlink_stmt_vdef (last.stmt); | |
1719 | release_defs (last.stmt); | |
1720 | gsi_remove (&gsi, true); | |
1721 | return; | |
1722 | } | |
1723 | ||
0ad84f34 | 1724 | if (!valid_builtin_call (last.stmt)) |
8b57bfeb JJ |
1725 | return; |
1726 | ||
3626621a | 1727 | callee = gimple_call_fndecl (last.stmt); |
8b57bfeb JJ |
1728 | switch (DECL_FUNCTION_CODE (callee)) |
1729 | { | |
1730 | case BUILT_IN_MEMCPY: | |
1731 | case BUILT_IN_MEMCPY_CHK: | |
1732 | break; | |
1733 | default: | |
1734 | return; | |
1735 | } | |
1736 | ||
f5fc4a04 | 1737 | len = gimple_call_arg (last.stmt, len_arg_no); |
cc269bb6 | 1738 | if (tree_fits_uhwi_p (len)) |
8b57bfeb | 1739 | { |
cc269bb6 | 1740 | if (!tree_fits_uhwi_p (last.len) |
8b57bfeb | 1741 | || integer_zerop (len) |
7d362f6c | 1742 | || tree_to_uhwi (len) != tree_to_uhwi (last.len) + 1) |
8b57bfeb JJ |
1743 | return; |
1744 | /* Don't adjust the length if it is divisible by 4, it is more efficient | |
1745 | to store the extra '\0' in that case. */ | |
7d362f6c | 1746 | if ((tree_to_uhwi (len) & 3) == 0) |
8b57bfeb | 1747 | return; |
7d4ae1fb BE |
1748 | |
1749 | /* Don't fold away an out of bounds access, as this defeats proper | |
1750 | warnings. */ | |
1751 | tree dst = gimple_call_arg (last.stmt, 0); | |
1752 | tree size = compute_objsize (dst, 0); | |
1753 | if (size && tree_int_cst_lt (size, len)) | |
1754 | return; | |
8b57bfeb JJ |
1755 | } |
1756 | else if (TREE_CODE (len) == SSA_NAME) | |
1757 | { | |
355fe088 | 1758 | gimple *def_stmt = SSA_NAME_DEF_STMT (len); |
8b57bfeb JJ |
1759 | if (!is_gimple_assign (def_stmt) |
1760 | || gimple_assign_rhs_code (def_stmt) != PLUS_EXPR | |
1761 | || gimple_assign_rhs1 (def_stmt) != last.len | |
1762 | || !integer_onep (gimple_assign_rhs2 (def_stmt))) | |
1763 | return; | |
1764 | } | |
1765 | else | |
1766 | return; | |
1767 | ||
f5fc4a04 | 1768 | gimple_call_set_arg (last.stmt, len_arg_no, last.len); |
8b57bfeb JJ |
1769 | update_stmt (last.stmt); |
1770 | } | |
1771 | ||
d4bf6975 MS |
1772 | /* For an LHS that is an SSA_NAME that is the result of a strlen() |
1773 | call, or when BOUND is non-null, of a strnlen() call, set LHS | |
1774 | range info to [0, min (MAX, BOUND)] when the range includes more | |
1775 | than one value and return LHS. Otherwise, when the range | |
1776 | [MIN, MAX] is such that MIN == MAX, return the tree representation | |
1777 | of (MIN). The latter allows callers to fold suitable strnlen() calls | |
1778 | to constants. */ | |
1779 | ||
1780 | tree | |
34fcf41e MS |
1781 | set_strlen_range (tree lhs, wide_int min, wide_int max, |
1782 | tree bound /* = NULL_TREE */) | |
06199618 | 1783 | { |
a7bf6c08 MS |
1784 | if (TREE_CODE (lhs) != SSA_NAME |
1785 | || !INTEGRAL_TYPE_P (TREE_TYPE (lhs))) | |
781ff3d8 | 1786 | return NULL_TREE; |
06199618 | 1787 | |
781ff3d8 MS |
1788 | if (bound) |
1789 | { | |
1790 | /* For strnlen, adjust MIN and MAX as necessary. If the bound | |
1791 | is less than the size of the array set MAX to it. It it's | |
1792 | greater than MAX and MAX is non-zero bump MAX down to account | |
1793 | for the necessary terminating nul. Otherwise leave it alone. */ | |
1794 | if (TREE_CODE (bound) == INTEGER_CST) | |
1795 | { | |
1796 | wide_int wibnd = wi::to_wide (bound); | |
1797 | int cmp = wi::cmpu (wibnd, max); | |
1798 | if (cmp < 0) | |
1799 | max = wibnd; | |
1800 | else if (cmp && wi::ne_p (max, min)) | |
1801 | --max; | |
1802 | } | |
1803 | else if (TREE_CODE (bound) == SSA_NAME) | |
1804 | { | |
1805 | wide_int minbound, maxbound; | |
54994253 | 1806 | value_range_kind rng = get_range_info (bound, &minbound, &maxbound); |
781ff3d8 MS |
1807 | if (rng == VR_RANGE) |
1808 | { | |
1809 | /* For a bound in a known range, adjust the range determined | |
1810 | above as necessary. For a bound in some anti-range or | |
d4bf6975 | 1811 | in an unknown range, use the range determined by callers. */ |
781ff3d8 MS |
1812 | if (wi::ltu_p (minbound, min)) |
1813 | min = minbound; | |
1814 | if (wi::ltu_p (maxbound, max)) | |
1815 | max = maxbound; | |
1816 | } | |
1817 | } | |
1818 | } | |
1819 | ||
1820 | if (min == max) | |
1821 | return wide_int_to_tree (size_type_node, min); | |
1822 | ||
1823 | set_range_info (lhs, VR_RANGE, min, max); | |
1824 | return lhs; | |
06199618 MS |
1825 | } |
1826 | ||
d4bf6975 MS |
1827 | /* For an LHS that is an SSA_NAME and for strlen() or strnlen() argument |
1828 | SRC, set LHS range info to [0, min (N, BOUND)] if SRC refers to | |
1829 | a character array A[N] with unknown length bounded by N, and for | |
1830 | strnlen(), by min (N, BOUND). */ | |
1831 | ||
1832 | static tree | |
1833 | maybe_set_strlen_range (tree lhs, tree src, tree bound) | |
1834 | { | |
1835 | if (TREE_CODE (lhs) != SSA_NAME | |
1836 | || !INTEGRAL_TYPE_P (TREE_TYPE (lhs))) | |
1837 | return NULL_TREE; | |
1838 | ||
1839 | if (TREE_CODE (src) == SSA_NAME) | |
1840 | { | |
1841 | gimple *def = SSA_NAME_DEF_STMT (src); | |
1842 | if (is_gimple_assign (def) | |
1843 | && gimple_assign_rhs_code (def) == ADDR_EXPR) | |
1844 | src = gimple_assign_rhs1 (def); | |
1845 | } | |
1846 | ||
1847 | /* The longest string is PTRDIFF_MAX - 1 bytes including the final | |
1848 | NUL so that the difference between a pointer to just past it and | |
1849 | one to its beginning is positive. */ | |
1850 | wide_int max = wi::to_wide (TYPE_MAX_VALUE (ptrdiff_type_node)) - 2; | |
1851 | ||
1852 | if (TREE_CODE (src) == ADDR_EXPR) | |
1853 | { | |
1854 | /* The last array member of a struct can be bigger than its size | |
1855 | suggests if it's treated as a poor-man's flexible array member. */ | |
1856 | src = TREE_OPERAND (src, 0); | |
1857 | if (TREE_CODE (src) != MEM_REF | |
1858 | && !array_at_struct_end_p (src)) | |
1859 | { | |
1860 | tree type = TREE_TYPE (src); | |
1861 | tree size = TYPE_SIZE_UNIT (type); | |
1862 | if (size | |
1863 | && TREE_CODE (size) == INTEGER_CST | |
1864 | && !integer_zerop (size)) | |
1865 | { | |
1866 | /* Even though such uses of strlen would be undefined, | |
1867 | avoid relying on arrays of arrays in case some genius | |
1868 | decides to call strlen on an unterminated array element | |
1869 | that's followed by a terminated one. Likewise, avoid | |
1870 | assuming that a struct array member is necessarily | |
1871 | nul-terminated (the nul may be in the member that | |
1872 | follows). In those cases, assume that the length | |
1873 | of the string stored in such an array is bounded | |
1874 | by the size of the enclosing object if one can be | |
1875 | determined. */ | |
1876 | tree base = get_base_address (src); | |
1877 | if (VAR_P (base)) | |
1878 | { | |
1879 | if (tree size = DECL_SIZE_UNIT (base)) | |
1880 | if (size | |
1881 | && TREE_CODE (size) == INTEGER_CST | |
1882 | && TREE_CODE (TREE_TYPE (base)) != POINTER_TYPE) | |
1883 | max = wi::to_wide (size); | |
1884 | } | |
1885 | } | |
1886 | ||
1887 | /* For strlen() the upper bound above is equal to | |
1888 | the longest string that can be stored in the array | |
1889 | (i.e., it accounts for the terminating nul. For | |
1890 | strnlen() bump up the maximum by one since the array | |
1891 | need not be nul-terminated. */ | |
1892 | if (!bound && max != 0) | |
1893 | --max; | |
1894 | } | |
1895 | } | |
1896 | ||
34fcf41e MS |
1897 | wide_int min = wi::zero (max.get_precision ()); |
1898 | return set_strlen_range (lhs, min, max, bound); | |
d4bf6975 MS |
1899 | } |
1900 | ||
f7d86b5c | 1901 | /* Diagnose buffer overflow by a STMT writing LEN + PLUS_ONE bytes, |
ef29b12c MS |
1902 | either into a region allocated for the object SI when non-null, |
1903 | or into an object designated by the LHS of STMT otherwise. | |
1904 | When nonnull uses RVALS to determine range information. | |
1905 | RAWMEM may be set by memcpy and other raw memory functions | |
1906 | to allow accesses across subobject boundaries. */ | |
f7d86b5c MS |
1907 | |
1908 | static void | |
1909 | maybe_warn_overflow (gimple *stmt, tree len, | |
1910 | const vr_values *rvals = NULL, | |
ef29b12c MS |
1911 | strinfo *si = NULL, bool plus_one = false, |
1912 | bool rawmem = false) | |
f7d86b5c MS |
1913 | { |
1914 | if (!len || gimple_no_warning_p (stmt)) | |
1915 | return; | |
1916 | ||
ef29b12c MS |
1917 | /* The DECL of the function performing the write if it is done |
1918 | by one. */ | |
f7d86b5c | 1919 | tree writefn = NULL_TREE; |
ef29b12c | 1920 | /* The destination expression involved in the store STMT. */ |
f7d86b5c MS |
1921 | tree dest = NULL_TREE; |
1922 | ||
f7d86b5c | 1923 | if (is_gimple_assign (stmt)) |
ef29b12c | 1924 | dest = gimple_assign_lhs (stmt); |
f7d86b5c MS |
1925 | else if (is_gimple_call (stmt)) |
1926 | { | |
f7d86b5c | 1927 | dest = gimple_call_arg (stmt, 0); |
ef29b12c | 1928 | writefn = gimple_call_fndecl (stmt); |
f7d86b5c MS |
1929 | } |
1930 | ||
ef29b12c MS |
1931 | if (TREE_NO_WARNING (dest)) |
1932 | return; | |
1933 | ||
10bbbb59 MS |
1934 | /* Use maximum precision to avoid overflow in the addition below. |
1935 | Make sure all operands have the same precision to keep wide_int | |
1936 | from ICE'ing. */ | |
1937 | ||
1938 | /* Convenience constants. */ | |
1939 | const widest_int diff_min | |
1940 | = wi::to_widest (TYPE_MIN_VALUE (ptrdiff_type_node)); | |
1941 | const widest_int diff_max | |
1942 | = wi::to_widest (TYPE_MAX_VALUE (ptrdiff_type_node)); | |
1943 | const widest_int size_max | |
1944 | = wi::to_widest (TYPE_MAX_VALUE (size_type_node)); | |
1945 | ||
f7d86b5c | 1946 | /* The offset into the destination object computed below and not |
ef29b12c | 1947 | reflected in DESTSIZE. */ |
10bbbb59 | 1948 | widest_int offrng[2] = { 0, 0 }; |
f7d86b5c | 1949 | |
ef29b12c | 1950 | if (!si) |
f7d86b5c | 1951 | { |
ef29b12c MS |
1952 | /* If no destination STRINFO was provided try to get it from |
1953 | the DEST argument. */ | |
f7d86b5c | 1954 | tree ref = dest; |
f7d86b5c MS |
1955 | if (TREE_CODE (ref) == ARRAY_REF) |
1956 | { | |
1957 | /* Handle stores to VLAs (represented as | |
1958 | ARRAY_REF (MEM_REF (vlaptr, 0), N]. */ | |
ef29b12c | 1959 | tree off = TREE_OPERAND (ref, 1); |
f7d86b5c | 1960 | ref = TREE_OPERAND (ref, 0); |
10bbbb59 MS |
1961 | wide_int rng[2]; |
1962 | if (get_range (off, rng, rvals)) | |
ef29b12c | 1963 | { |
10bbbb59 MS |
1964 | /* Convert offsets to the maximum precision. */ |
1965 | offrng[0] = widest_int::from (rng[0], SIGNED); | |
1966 | offrng[1] = widest_int::from (rng[1], SIGNED); | |
ef29b12c MS |
1967 | } |
1968 | else | |
1969 | { | |
10bbbb59 MS |
1970 | offrng[0] = diff_min; |
1971 | offrng[1] = diff_max; | |
ef29b12c | 1972 | } |
f7d86b5c MS |
1973 | } |
1974 | ||
1975 | if (TREE_CODE (ref) == MEM_REF) | |
1976 | { | |
1977 | tree mem_off = TREE_OPERAND (ref, 1); | |
ef29b12c | 1978 | ref = TREE_OPERAND (ref, 0); |
10bbbb59 MS |
1979 | wide_int rng[2]; |
1980 | if (get_range (mem_off, rng, rvals)) | |
f7d86b5c | 1981 | { |
10bbbb59 MS |
1982 | offrng[0] += widest_int::from (rng[0], SIGNED); |
1983 | offrng[1] += widest_int::from (rng[1], SIGNED); | |
f7d86b5c MS |
1984 | } |
1985 | else | |
ef29b12c | 1986 | { |
10bbbb59 MS |
1987 | offrng[0] = diff_min; |
1988 | offrng[1] = diff_max; | |
ef29b12c | 1989 | } |
f7d86b5c MS |
1990 | } |
1991 | ||
10bbbb59 MS |
1992 | wide_int rng[2]; |
1993 | if (int idx = get_stridx (ref, rng, rvals)) | |
f7d86b5c MS |
1994 | { |
1995 | si = get_strinfo (idx); | |
10bbbb59 MS |
1996 | offrng[0] += widest_int::from (rng[0], SIGNED); |
1997 | offrng[1] += widest_int::from (rng[1], SIGNED); | |
ef29b12c MS |
1998 | } |
1999 | } | |
2000 | ||
2001 | /* The allocation call if the destination object was allocated | |
2002 | by one. */ | |
2003 | gimple *alloc_call = NULL; | |
2004 | /* The DECL of the destination object if known and not dynamically | |
2005 | allocated. */ | |
2006 | tree destdecl = NULL_TREE; | |
2007 | /* The offset into the destination object set by compute_objsize | |
2008 | but already reflected in DESTSIZE. */ | |
2009 | tree destoff = NULL_TREE; | |
2010 | /* The size of the destination region (which is smaller than | |
2011 | the destination object for stores at a non-zero offset). */ | |
2012 | tree destsize = NULL_TREE; | |
2013 | ||
2014 | /* Compute the range of sizes of the destination object. The range | |
2015 | is constant for declared objects but may be a range for allocated | |
2016 | objects. */ | |
10bbbb59 | 2017 | widest_int sizrng[2] = { 0, 0 }; |
ef29b12c MS |
2018 | if (si) |
2019 | { | |
10bbbb59 MS |
2020 | wide_int rng[2]; |
2021 | destsize = gimple_call_alloc_size (si->alloc, rng, rvals); | |
2022 | if (destsize) | |
2023 | { | |
2024 | sizrng[0] = widest_int::from (rng[0], UNSIGNED); | |
2025 | sizrng[1] = widest_int::from (rng[1], UNSIGNED); | |
2026 | } | |
ef29b12c MS |
2027 | alloc_call = si->alloc; |
2028 | } | |
2029 | else | |
10bbbb59 | 2030 | offrng[0] = offrng[1] = 0; |
ef29b12c MS |
2031 | |
2032 | if (!destsize) | |
2033 | { | |
2034 | /* If there is no STRINFO for DEST, fall back on compute_objsize. */ | |
2035 | tree off = NULL_TREE; | |
2036 | destsize = compute_objsize (dest, rawmem ? 0 : 1, &destdecl, &off, rvals); | |
2037 | if (destsize) | |
2038 | { | |
2039 | /* Remember OFF but clear OFFRNG that may have been set above. */ | |
2040 | destoff = off; | |
10bbbb59 | 2041 | offrng[0] = offrng[1] = 0; |
ef29b12c MS |
2042 | |
2043 | if (destdecl && TREE_CODE (destdecl) == SSA_NAME) | |
f7d86b5c | 2044 | { |
ef29b12c MS |
2045 | gimple *stmt = SSA_NAME_DEF_STMT (destdecl); |
2046 | if (is_gimple_call (stmt)) | |
2047 | alloc_call = stmt; | |
2048 | destdecl = NULL_TREE; | |
2049 | } | |
2050 | ||
10bbbb59 MS |
2051 | wide_int rng[2]; |
2052 | if (get_range (destsize, rng, rvals)) | |
2053 | { | |
2054 | sizrng[0] = widest_int::from (rng[0], UNSIGNED); | |
2055 | sizrng[1] = widest_int::from (rng[1], UNSIGNED); | |
2056 | } | |
2057 | else | |
ef29b12c MS |
2058 | { |
2059 | /* On failure, rather than failing, set the maximum range | |
2060 | so that overflow in allocated objects whose size depends | |
2061 | on the strlen of the source can still be diagnosed | |
2062 | below. */ | |
10bbbb59 MS |
2063 | sizrng[0] = 0; |
2064 | sizrng[1] = size_max; | |
f7d86b5c MS |
2065 | } |
2066 | } | |
f7d86b5c MS |
2067 | } |
2068 | ||
ef29b12c MS |
2069 | if (!destsize) |
2070 | { | |
10bbbb59 MS |
2071 | sizrng[0] = 0; |
2072 | sizrng[1] = size_max; | |
ef29b12c MS |
2073 | }; |
2074 | ||
f7d86b5c MS |
2075 | /* Return early if the DESTSIZE size expression is the same as LEN |
2076 | and the offset into the destination is zero. This might happen | |
2077 | in the case of a pair of malloc and memset calls to allocate | |
2078 | an object and clear it as if by calloc. */ | |
2079 | if (destsize == len && !plus_one && offrng[0] == 0 && offrng[0] == offrng[1]) | |
2080 | return; | |
2081 | ||
10bbbb59 MS |
2082 | wide_int rng[2]; |
2083 | if (!get_range (len, rng, rvals)) | |
f7d86b5c MS |
2084 | return; |
2085 | ||
10bbbb59 MS |
2086 | widest_int lenrng[2] = |
2087 | { widest_int::from (rng[0], SIGNED), widest_int::from (rng[1], SIGNED) }; | |
2088 | ||
f7d86b5c MS |
2089 | if (plus_one) |
2090 | { | |
2091 | lenrng[0] += 1; | |
2092 | lenrng[1] += 1; | |
2093 | } | |
2094 | ||
ef29b12c MS |
2095 | /* The size of the remaining space in the destination computed |
2096 | as the size of the latter minus the offset into it. */ | |
10bbbb59 | 2097 | widest_int spcrng[2] = { sizrng[0], sizrng[1] }; |
ef29b12c | 2098 | if (wi::neg_p (offrng[0]) && wi::neg_p (offrng[1])) |
f7d86b5c | 2099 | { |
ef29b12c MS |
2100 | /* When the offset is negative and the size of the destination |
2101 | object unknown there is little to do. | |
2102 | FIXME: Detect offsets that are necessarily invalid regardless | |
2103 | of the size of the object. */ | |
2104 | if (!destsize) | |
f7d86b5c | 2105 | return; |
ef29b12c MS |
2106 | |
2107 | /* The remaining space is necessarily zero. */ | |
10bbbb59 | 2108 | spcrng[0] = spcrng[1] = 0; |
ef29b12c MS |
2109 | } |
2110 | else if (wi::neg_p (offrng[0])) | |
2111 | { | |
2112 | /* When the lower bound of the offset is negative but the upper | |
2113 | bound is not, reduce the upper bound of the remaining space | |
2114 | by the upper bound of the offset but leave the lower bound | |
2115 | unchanged. If that makes the upper bound of the space less | |
2116 | than the lower bound swap the two. */ | |
2117 | spcrng[1] -= wi::ltu_p (offrng[1], spcrng[1]) ? offrng[1] : spcrng[1]; | |
2118 | if (wi::ltu_p (spcrng[1], spcrng[0])) | |
2119 | std::swap (spcrng[1], spcrng[0]); | |
f7d86b5c MS |
2120 | } |
2121 | else | |
2122 | { | |
ef29b12c MS |
2123 | /* When the offset is positive reduce the remaining space by |
2124 | the lower bound of the offset or clear it if the offset is | |
2125 | greater. */ | |
f7d86b5c MS |
2126 | spcrng[0] -= wi::ltu_p (offrng[0], spcrng[0]) ? offrng[0] : spcrng[0]; |
2127 | spcrng[1] -= wi::ltu_p (offrng[0], spcrng[1]) ? offrng[0] : spcrng[1]; | |
2128 | } | |
2129 | ||
ef29b12c MS |
2130 | if (wi::leu_p (lenrng[0], spcrng[0]) |
2131 | && wi::leu_p (lenrng[1], spcrng[1])) | |
f7d86b5c MS |
2132 | return; |
2133 | ||
2134 | if (lenrng[0] == spcrng[1] | |
2135 | && (len != destsize | |
2136 | || !si || !is_strlen_related_p (si->ptr, len))) | |
2137 | return; | |
2138 | ||
55ace4d1 | 2139 | location_t loc = gimple_or_expr_nonartificial_location (stmt, dest); |
f7d86b5c MS |
2140 | bool warned = false; |
2141 | if (wi::leu_p (lenrng[0], spcrng[1])) | |
2142 | { | |
2143 | if (len != destsize | |
2144 | && (!si || !is_strlen_related_p (si->ptr, len))) | |
2145 | return; | |
2146 | ||
2147 | warned = (writefn | |
2148 | ? warning_at (loc, OPT_Wstringop_overflow_, | |
2149 | "%G%qD writing one too many bytes into a region " | |
2150 | "of a size that depends on %<strlen%>", | |
2151 | stmt, writefn) | |
2152 | : warning_at (loc, OPT_Wstringop_overflow_, | |
2153 | "%Gwriting one too many bytes into a region " | |
2154 | "of a size that depends on %<strlen%>", | |
2155 | stmt)); | |
2156 | } | |
2157 | else if (lenrng[0] == lenrng[1]) | |
2158 | { | |
2159 | if (spcrng[0] == spcrng[1]) | |
2160 | warned = (writefn | |
2161 | ? warning_n (loc, OPT_Wstringop_overflow_, | |
2162 | lenrng[0].to_uhwi (), | |
2163 | "%G%qD writing %wu byte into a region " | |
2164 | "of size %wu", | |
2165 | "%G%qD writing %wu bytes into a region " | |
2166 | "of size %wu", | |
2167 | stmt, writefn, lenrng[0].to_uhwi (), | |
2168 | spcrng[0].to_uhwi ()) | |
2169 | : warning_n (loc, OPT_Wstringop_overflow_, | |
2170 | lenrng[0].to_uhwi (), | |
2171 | "%Gwriting %wu byte into a region " | |
2172 | "of size %wu", | |
2173 | "%Gwriting %wu bytes into a region " | |
2174 | "of size %wu", | |
2175 | stmt, lenrng[0].to_uhwi (), | |
2176 | spcrng[0].to_uhwi ())); | |
2177 | else | |
2178 | warned = (writefn | |
2179 | ? warning_n (loc, OPT_Wstringop_overflow_, | |
2180 | lenrng[0].to_uhwi (), | |
2181 | "%G%qD writing %wu byte into a region " | |
2182 | "of size between %wu and %wu", | |
2183 | "%G%qD writing %wu bytes into a region " | |
2184 | "of size between %wu and %wu", | |
2185 | stmt, writefn, lenrng[0].to_uhwi (), | |
2186 | spcrng[0].to_uhwi (), spcrng[1].to_uhwi ()) | |
2187 | : warning_n (loc, OPT_Wstringop_overflow_, | |
2188 | lenrng[0].to_uhwi (), | |
2189 | "%Gwriting %wu byte into a region " | |
2190 | "of size between %wu and %wu", | |
2191 | "%Gwriting %wu bytes into a region " | |
2192 | "of size between %wu and %wu", | |
2193 | stmt, lenrng[0].to_uhwi (), | |
2194 | spcrng[0].to_uhwi (), spcrng[1].to_uhwi ())); | |
2195 | } | |
2196 | else if (spcrng[0] == spcrng[1]) | |
2197 | warned = (writefn | |
2198 | ? warning_at (loc, OPT_Wstringop_overflow_, | |
2199 | "%G%qD writing between %wu and %wu bytes " | |
2200 | "into a region of size %wu", | |
2201 | stmt, writefn, lenrng[0].to_uhwi (), | |
2202 | lenrng[1].to_uhwi (), | |
2203 | spcrng[0].to_uhwi ()) | |
2204 | : warning_at (loc, OPT_Wstringop_overflow_, | |
2205 | "%Gwriting between %wu and %wu bytes " | |
2206 | "into a region of size %wu", | |
2207 | stmt, lenrng[0].to_uhwi (), | |
2208 | lenrng[1].to_uhwi (), | |
2209 | spcrng[0].to_uhwi ())); | |
2210 | else | |
2211 | warned = (writefn | |
2212 | ? warning_at (loc, OPT_Wstringop_overflow_, | |
2213 | "%G%qD writing between %wu and %wu bytes " | |
2214 | "into a region of size between %wu and %wu", | |
2215 | stmt, writefn, lenrng[0].to_uhwi (), | |
2216 | lenrng[1].to_uhwi (), | |
2217 | spcrng[0].to_uhwi (), spcrng[1].to_uhwi ()) | |
2218 | : warning_at (loc, OPT_Wstringop_overflow_, | |
2219 | "%Gwriting between %wu and %wu bytes " | |
2220 | "into a region of size between %wu and %wu", | |
2221 | stmt, lenrng[0].to_uhwi (), | |
2222 | lenrng[1].to_uhwi (), | |
2223 | spcrng[0].to_uhwi (), spcrng[1].to_uhwi ())); | |
2224 | ||
2225 | if (!warned) | |
2226 | return; | |
2227 | ||
ef29b12c MS |
2228 | gimple_set_no_warning (stmt, true); |
2229 | ||
f7d86b5c MS |
2230 | /* If DESTOFF is not null, use it to format the offset value/range. */ |
2231 | if (destoff) | |
10bbbb59 MS |
2232 | { |
2233 | wide_int rng[2]; | |
2234 | if (get_range (destoff, rng)) | |
2235 | { | |
2236 | offrng[0] = widest_int::from (rng[0], SIGNED); | |
2237 | offrng[1] = widest_int::from (rng[1], SIGNED); | |
2238 | } | |
2239 | else | |
2240 | offrng[0] = offrng[1] = 0; | |
2241 | } | |
f7d86b5c MS |
2242 | |
2243 | /* Format the offset to keep the number of inform calls from growing | |
2244 | out of control. */ | |
2245 | char offstr[64]; | |
2246 | if (offrng[0] == offrng[1]) | |
2247 | sprintf (offstr, "%lli", (long long) offrng[0].to_shwi ()); | |
2248 | else | |
2249 | sprintf (offstr, "[%lli, %lli]", | |
2250 | (long long) offrng[0].to_shwi (), (long long) offrng[1].to_shwi ()); | |
2251 | ||
2252 | if (destdecl) | |
2253 | { | |
2254 | if (tree size = DECL_SIZE_UNIT (destdecl)) | |
2255 | inform (DECL_SOURCE_LOCATION (destdecl), | |
2256 | "at offset %s to object %qD with size %E declared here", | |
2257 | offstr, destdecl, size); | |
2258 | else | |
2259 | inform (DECL_SOURCE_LOCATION (destdecl), | |
2260 | "at offset %s to object %qD declared here", | |
2261 | offstr, destdecl); | |
2262 | return; | |
2263 | } | |
ef29b12c MS |
2264 | |
2265 | if (!alloc_call) | |
2266 | return; | |
2267 | ||
2268 | tree allocfn = gimple_call_fndecl (alloc_call); | |
2269 | if (!allocfn) | |
2270 | { | |
2271 | /* For an ALLOC_CALL via a function pointer make a small effort | |
2272 | to determine the destination of the pointer. */ | |
2273 | allocfn = gimple_call_fn (alloc_call); | |
2274 | if (TREE_CODE (allocfn) == SSA_NAME) | |
2275 | { | |
2276 | gimple *def = SSA_NAME_DEF_STMT (allocfn); | |
2277 | if (gimple_assign_single_p (def)) | |
2278 | { | |
2279 | tree rhs = gimple_assign_rhs1 (def); | |
2280 | if (DECL_P (rhs)) | |
2281 | allocfn = rhs; | |
2282 | else if (TREE_CODE (rhs) == COMPONENT_REF) | |
2283 | allocfn = TREE_OPERAND (rhs, 1); | |
2284 | } | |
2285 | } | |
2286 | } | |
2287 | ||
2288 | if (gimple_call_builtin_p (alloc_call, BUILT_IN_ALLOCA_WITH_ALIGN)) | |
2289 | { | |
2290 | if (sizrng[0] == sizrng[1]) | |
2291 | inform (gimple_location (alloc_call), | |
2292 | "at offset %s to an object with size %wu declared here", | |
2293 | offstr, sizrng[0].to_uhwi ()); | |
2294 | else if (sizrng[0] == 0) | |
2295 | { | |
2296 | /* Avoid printing impossible sizes. */ | |
10bbbb59 | 2297 | if (wi::ltu_p (sizrng[1], diff_max - 2)) |
ef29b12c MS |
2298 | inform (gimple_location (alloc_call), |
2299 | "at offset %s to an object with size at most %wu " | |
2300 | "declared here", | |
2301 | offstr, sizrng[1].to_uhwi ()); | |
2302 | else | |
2303 | inform (gimple_location (alloc_call), | |
2304 | "at offset %s to an object declared here", offstr); | |
2305 | } | |
2306 | else | |
2307 | inform (gimple_location (alloc_call), | |
2308 | "at offset %s to an object with size between %wu and %wu " | |
2309 | "declared here", | |
2310 | offstr, sizrng[0].to_uhwi (), sizrng[1].to_uhwi ()); | |
2311 | return; | |
2312 | } | |
2313 | ||
2314 | if (sizrng[0] == sizrng[1]) | |
2315 | inform (gimple_location (alloc_call), | |
2316 | "at offset %s to an object with size %wu allocated by %qE here", | |
2317 | offstr, sizrng[0].to_uhwi (), allocfn); | |
2318 | else if (sizrng[0] == 0) | |
2319 | { | |
2320 | /* Avoid printing impossible sizes. */ | |
10bbbb59 | 2321 | if (wi::ltu_p (sizrng[1], diff_max - 2)) |
ef29b12c MS |
2322 | inform (gimple_location (alloc_call), |
2323 | "at offset %s to an object with size at most %wu allocated " | |
2324 | "by %qD here", | |
2325 | offstr, sizrng[1].to_uhwi (), allocfn); | |
2326 | else | |
2327 | inform (gimple_location (alloc_call), | |
2328 | "at offset %s to an object allocated by %qE here", | |
2329 | offstr, allocfn); | |
2330 | } | |
2331 | else | |
2332 | inform (gimple_location (alloc_call), | |
2333 | "at offset %s to an object with size between %wu and %wu " | |
2334 | "allocated by %qE here", | |
2335 | offstr, sizrng[0].to_uhwi (), sizrng[1].to_uhwi (), allocfn); | |
f7d86b5c MS |
2336 | } |
2337 | ||
2338 | /* Convenience wrapper for the above. */ | |
2339 | ||
2340 | static inline void | |
2341 | maybe_warn_overflow (gimple *stmt, unsigned HOST_WIDE_INT len, | |
ef29b12c MS |
2342 | const vr_values *rvals = NULL, strinfo *si = NULL, |
2343 | bool plus_one = false, bool rawmem = false) | |
f7d86b5c MS |
2344 | { |
2345 | maybe_warn_overflow (stmt, build_int_cst (size_type_node, len), rvals, | |
ef29b12c | 2346 | si, plus_one, rawmem); |
f7d86b5c MS |
2347 | } |
2348 | ||
8b57bfeb JJ |
2349 | /* Handle a strlen call. If strlen of the argument is known, replace |
2350 | the strlen call with the known value, otherwise remember that strlen | |
2351 | of the argument is stored in the lhs SSA_NAME. */ | |
2352 | ||
2353 | static void | |
2354 | handle_builtin_strlen (gimple_stmt_iterator *gsi) | |
2355 | { | |
355fe088 | 2356 | gimple *stmt = gsi_stmt (*gsi); |
8b57bfeb JJ |
2357 | tree lhs = gimple_call_lhs (stmt); |
2358 | ||
2359 | if (lhs == NULL_TREE) | |
2360 | return; | |
2361 | ||
781ff3d8 MS |
2362 | location_t loc = gimple_location (stmt); |
2363 | tree callee = gimple_call_fndecl (stmt); | |
2364 | tree src = gimple_call_arg (stmt, 0); | |
2365 | tree bound = (DECL_FUNCTION_CODE (callee) == BUILT_IN_STRNLEN | |
2366 | ? gimple_call_arg (stmt, 1) : NULL_TREE); | |
2367 | int idx = get_stridx (src); | |
9bc83f27 | 2368 | if (idx || (bound && integer_zerop (bound))) |
8b57bfeb | 2369 | { |
526ceb68 | 2370 | strinfo *si = NULL; |
8b57bfeb JJ |
2371 | tree rhs; |
2372 | ||
2373 | if (idx < 0) | |
2374 | rhs = build_int_cst (TREE_TYPE (lhs), ~idx); | |
9bc83f27 JJ |
2375 | else if (idx == 0) |
2376 | rhs = bound; | |
8b57bfeb JJ |
2377 | else |
2378 | { | |
2379 | rhs = NULL_TREE; | |
2380 | si = get_strinfo (idx); | |
2381 | if (si != NULL) | |
9bc83f27 JJ |
2382 | { |
2383 | rhs = get_string_length (si); | |
2384 | /* For strnlen, if bound is constant, even if si is not known | |
2385 | to be zero terminated, if we know at least bound bytes are | |
2386 | not zero, the return value will be bound. */ | |
2387 | if (rhs == NULL_TREE | |
2388 | && bound != NULL_TREE | |
2389 | && TREE_CODE (bound) == INTEGER_CST | |
2390 | && si->nonzero_chars != NULL_TREE | |
2391 | && TREE_CODE (si->nonzero_chars) == INTEGER_CST | |
2392 | && tree_int_cst_le (bound, si->nonzero_chars)) | |
2393 | rhs = bound; | |
2394 | } | |
8b57bfeb JJ |
2395 | } |
2396 | if (rhs != NULL_TREE) | |
2397 | { | |
2398 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
2399 | { | |
2400 | fprintf (dump_file, "Optimizing: "); | |
2401 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
2402 | } | |
2403 | rhs = unshare_expr (rhs); | |
2404 | if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs))) | |
781ff3d8 | 2405 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); |
b36bc89e | 2406 | |
781ff3d8 | 2407 | if (bound) |
9bc83f27 | 2408 | rhs = fold_build2_loc (loc, MIN_EXPR, TREE_TYPE (rhs), rhs, bound); |
b36bc89e | 2409 | |
8b57bfeb JJ |
2410 | if (!update_call_from_tree (gsi, rhs)) |
2411 | gimplify_and_update_call_from_tree (gsi, rhs); | |
2412 | stmt = gsi_stmt (*gsi); | |
2413 | update_stmt (stmt); | |
2414 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
2415 | { | |
2416 | fprintf (dump_file, "into: "); | |
2417 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
2418 | } | |
b36bc89e | 2419 | |
8b57bfeb | 2420 | if (si != NULL |
9bc83f27 JJ |
2421 | /* Don't update anything for strnlen. */ |
2422 | && bound == NULL_TREE | |
e3f9a279 RS |
2423 | && TREE_CODE (si->nonzero_chars) != SSA_NAME |
2424 | && TREE_CODE (si->nonzero_chars) != INTEGER_CST | |
8b57bfeb JJ |
2425 | && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) |
2426 | { | |
2427 | si = unshare_strinfo (si); | |
e3f9a279 RS |
2428 | si->nonzero_chars = lhs; |
2429 | gcc_assert (si->full_string_p); | |
8b57bfeb | 2430 | } |
025d57f0 | 2431 | |
9bc83f27 JJ |
2432 | if (strlen_to_stridx |
2433 | && (bound == NULL_TREE | |
2434 | /* For strnlen record this only if the call is proven | |
2435 | to return the same value as strlen would. */ | |
2436 | || (TREE_CODE (bound) == INTEGER_CST | |
2437 | && TREE_CODE (rhs) == INTEGER_CST | |
2438 | && tree_int_cst_lt (rhs, bound)))) | |
781ff3d8 MS |
2439 | strlen_to_stridx->put (lhs, stridx_strlenloc (idx, loc)); |
2440 | ||
8b57bfeb JJ |
2441 | return; |
2442 | } | |
2443 | } | |
2444 | if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) | |
2445 | return; | |
b36bc89e | 2446 | |
8b57bfeb JJ |
2447 | if (idx == 0) |
2448 | idx = new_stridx (src); | |
e3f9a279 RS |
2449 | else |
2450 | { | |
2451 | strinfo *si = get_strinfo (idx); | |
2452 | if (si != NULL) | |
2453 | { | |
2454 | if (!si->full_string_p && !si->stmt) | |
2455 | { | |
2456 | /* Until now we only had a lower bound on the string length. | |
2457 | Install LHS as the actual length. */ | |
2458 | si = unshare_strinfo (si); | |
1aad7106 | 2459 | tree old = si->nonzero_chars; |
e3f9a279 RS |
2460 | si->nonzero_chars = lhs; |
2461 | si->full_string_p = true; | |
ef29b12c | 2462 | if (old && TREE_CODE (old) == INTEGER_CST) |
1aad7106 | 2463 | { |
1aad7106 RS |
2464 | old = fold_convert_loc (loc, TREE_TYPE (lhs), old); |
2465 | tree adj = fold_build2_loc (loc, MINUS_EXPR, | |
2466 | TREE_TYPE (lhs), lhs, old); | |
2467 | adjust_related_strinfos (loc, si, adj); | |
dfea3d6f | 2468 | /* Use the constant minimum length as the lower bound |
34fcf41e MS |
2469 | of the non-constant length. */ |
2470 | wide_int min = wi::to_wide (old); | |
2471 | wide_int max | |
2472 | = wi::to_wide (TYPE_MAX_VALUE (ptrdiff_type_node)) - 2; | |
2473 | set_strlen_range (lhs, min, max); | |
1aad7106 RS |
2474 | } |
2475 | else | |
2476 | { | |
2477 | si->first = 0; | |
2478 | si->prev = 0; | |
2479 | si->next = 0; | |
2480 | } | |
e3f9a279 RS |
2481 | } |
2482 | return; | |
2483 | } | |
2484 | } | |
8b57bfeb JJ |
2485 | if (idx) |
2486 | { | |
b36bc89e MS |
2487 | if (!bound) |
2488 | { | |
2489 | /* Only store the new length information for calls to strlen(), | |
2490 | not for those to strnlen(). */ | |
2491 | strinfo *si = new_strinfo (src, idx, lhs, true); | |
2492 | set_strinfo (idx, si); | |
2493 | find_equal_ptrs (src, idx); | |
2494 | } | |
025d57f0 | 2495 | |
06199618 | 2496 | /* For SRC that is an array of N elements, set LHS's range |
781ff3d8 MS |
2497 | to [0, min (N, BOUND)]. A constant return value means |
2498 | the range would have consisted of a single value. In | |
2499 | that case, fold the result into the returned constant. */ | |
2500 | if (tree ret = maybe_set_strlen_range (lhs, src, bound)) | |
2501 | if (TREE_CODE (ret) == INTEGER_CST) | |
2502 | { | |
2503 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
2504 | { | |
2505 | fprintf (dump_file, "Optimizing: "); | |
2506 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
2507 | } | |
2508 | if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (ret))) | |
2509 | ret = fold_convert_loc (loc, TREE_TYPE (lhs), ret); | |
2510 | if (!update_call_from_tree (gsi, ret)) | |
2511 | gimplify_and_update_call_from_tree (gsi, ret); | |
2512 | stmt = gsi_stmt (*gsi); | |
2513 | update_stmt (stmt); | |
2514 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
2515 | { | |
2516 | fprintf (dump_file, "into: "); | |
2517 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
2518 | } | |
2519 | } | |
06199618 | 2520 | |
b36bc89e | 2521 | if (strlen_to_stridx && !bound) |
781ff3d8 | 2522 | strlen_to_stridx->put (lhs, stridx_strlenloc (idx, loc)); |
8b57bfeb JJ |
2523 | } |
2524 | } | |
2525 | ||
2526 | /* Handle a strchr call. If strlen of the first argument is known, replace | |
2527 | the strchr (x, 0) call with the endptr or x + strlen, otherwise remember | |
2528 | that lhs of the call is endptr and strlen of the argument is endptr - x. */ | |
2529 | ||
2530 | static void | |
2531 | handle_builtin_strchr (gimple_stmt_iterator *gsi) | |
2532 | { | |
355fe088 | 2533 | gimple *stmt = gsi_stmt (*gsi); |
8b57bfeb JJ |
2534 | tree lhs = gimple_call_lhs (stmt); |
2535 | ||
2536 | if (lhs == NULL_TREE) | |
2537 | return; | |
2538 | ||
31db0fe0 | 2539 | if (!integer_zerop (gimple_call_arg (stmt, 1))) |
8b57bfeb JJ |
2540 | return; |
2541 | ||
b5338fb3 MS |
2542 | tree src = gimple_call_arg (stmt, 0); |
2543 | ||
2544 | /* Avoid folding if the first argument is not a nul-terminated array. | |
2545 | Defer warning until later. */ | |
2546 | if (!check_nul_terminated_array (NULL_TREE, src)) | |
2547 | return; | |
2548 | ||
2549 | int idx = get_stridx (src); | |
8b57bfeb JJ |
2550 | if (idx) |
2551 | { | |
526ceb68 | 2552 | strinfo *si = NULL; |
8b57bfeb JJ |
2553 | tree rhs; |
2554 | ||
2555 | if (idx < 0) | |
2556 | rhs = build_int_cst (size_type_node, ~idx); | |
2557 | else | |
2558 | { | |
2559 | rhs = NULL_TREE; | |
2560 | si = get_strinfo (idx); | |
2561 | if (si != NULL) | |
2562 | rhs = get_string_length (si); | |
2563 | } | |
2564 | if (rhs != NULL_TREE) | |
2565 | { | |
2566 | location_t loc = gimple_location (stmt); | |
2567 | ||
2568 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
2569 | { | |
2570 | fprintf (dump_file, "Optimizing: "); | |
2571 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
2572 | } | |
2573 | if (si != NULL && si->endptr != NULL_TREE) | |
2574 | { | |
2575 | rhs = unshare_expr (si->endptr); | |
2576 | if (!useless_type_conversion_p (TREE_TYPE (lhs), | |
2577 | TREE_TYPE (rhs))) | |
2578 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); | |
2579 | } | |
2580 | else | |
2581 | { | |
2582 | rhs = fold_convert_loc (loc, sizetype, unshare_expr (rhs)); | |
2583 | rhs = fold_build2_loc (loc, POINTER_PLUS_EXPR, | |
2584 | TREE_TYPE (src), src, rhs); | |
2585 | if (!useless_type_conversion_p (TREE_TYPE (lhs), | |
2586 | TREE_TYPE (rhs))) | |
2587 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); | |
2588 | } | |
2589 | if (!update_call_from_tree (gsi, rhs)) | |
2590 | gimplify_and_update_call_from_tree (gsi, rhs); | |
2591 | stmt = gsi_stmt (*gsi); | |
2592 | update_stmt (stmt); | |
2593 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
2594 | { | |
2595 | fprintf (dump_file, "into: "); | |
2596 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
2597 | } | |
2598 | if (si != NULL | |
2599 | && si->endptr == NULL_TREE | |
2600 | && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) | |
2601 | { | |
2602 | si = unshare_strinfo (si); | |
2603 | si->endptr = lhs; | |
2604 | } | |
2605 | zero_length_string (lhs, si); | |
2606 | return; | |
2607 | } | |
2608 | } | |
2609 | if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) | |
2610 | return; | |
2611 | if (TREE_CODE (src) != SSA_NAME || !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (src)) | |
2612 | { | |
2613 | if (idx == 0) | |
2614 | idx = new_stridx (src); | |
2615 | else if (get_strinfo (idx) != NULL) | |
2616 | { | |
2617 | zero_length_string (lhs, NULL); | |
2618 | return; | |
2619 | } | |
2620 | if (idx) | |
2621 | { | |
2622 | location_t loc = gimple_location (stmt); | |
2623 | tree lhsu = fold_convert_loc (loc, size_type_node, lhs); | |
2624 | tree srcu = fold_convert_loc (loc, size_type_node, src); | |
2625 | tree length = fold_build2_loc (loc, MINUS_EXPR, | |
2626 | size_type_node, lhsu, srcu); | |
e3f9a279 | 2627 | strinfo *si = new_strinfo (src, idx, length, true); |
8b57bfeb JJ |
2628 | si->endptr = lhs; |
2629 | set_strinfo (idx, si); | |
2630 | find_equal_ptrs (src, idx); | |
2631 | zero_length_string (lhs, si); | |
2632 | } | |
2633 | } | |
2634 | else | |
2635 | zero_length_string (lhs, NULL); | |
2636 | } | |
2637 | ||
2638 | /* Handle a strcpy-like ({st{r,p}cpy,__st{r,p}cpy_chk}) call. | |
2639 | If strlen of the second argument is known, strlen of the first argument | |
2640 | is the same after this call. Furthermore, attempt to convert it to | |
ef29b12c | 2641 | memcpy. Uses RVALS to determine range information. */ |
8b57bfeb JJ |
2642 | |
2643 | static void | |
ef29b12c MS |
2644 | handle_builtin_strcpy (enum built_in_function bcode, gimple_stmt_iterator *gsi, |
2645 | const vr_values *rvals) | |
8b57bfeb JJ |
2646 | { |
2647 | int idx, didx; | |
cc8bea0a | 2648 | tree src, dst, srclen, len, lhs, type, fn, oldlen; |
8b57bfeb | 2649 | bool success; |
355fe088 | 2650 | gimple *stmt = gsi_stmt (*gsi); |
526ceb68 | 2651 | strinfo *si, *dsi, *olddsi, *zsi; |
8b57bfeb JJ |
2652 | location_t loc; |
2653 | ||
31db0fe0 | 2654 | src = gimple_call_arg (stmt, 1); |
8b57bfeb JJ |
2655 | dst = gimple_call_arg (stmt, 0); |
2656 | lhs = gimple_call_lhs (stmt); | |
2657 | idx = get_stridx (src); | |
2658 | si = NULL; | |
2659 | if (idx > 0) | |
2660 | si = get_strinfo (idx); | |
2661 | ||
2662 | didx = get_stridx (dst); | |
2663 | olddsi = NULL; | |
2664 | oldlen = NULL_TREE; | |
2665 | if (didx > 0) | |
2666 | olddsi = get_strinfo (didx); | |
2667 | else if (didx < 0) | |
2668 | return; | |
2669 | ||
2670 | if (olddsi != NULL) | |
2671 | adjust_last_stmt (olddsi, stmt, false); | |
2672 | ||
2673 | srclen = NULL_TREE; | |
2674 | if (si != NULL) | |
2675 | srclen = get_string_length (si); | |
2676 | else if (idx < 0) | |
2677 | srclen = build_int_cst (size_type_node, ~idx); | |
2678 | ||
ef29b12c MS |
2679 | maybe_warn_overflow (stmt, srclen, rvals, olddsi, true); |
2680 | ||
2681 | if (olddsi != NULL) | |
2682 | adjust_last_stmt (olddsi, stmt, false); | |
2683 | ||
8b57bfeb JJ |
2684 | loc = gimple_location (stmt); |
2685 | if (srclen == NULL_TREE) | |
2686 | switch (bcode) | |
2687 | { | |
2688 | case BUILT_IN_STRCPY: | |
2689 | case BUILT_IN_STRCPY_CHK: | |
e79983f4 | 2690 | if (lhs != NULL_TREE || !builtin_decl_implicit_p (BUILT_IN_STPCPY)) |
8b57bfeb JJ |
2691 | return; |
2692 | break; | |
2693 | case BUILT_IN_STPCPY: | |
2694 | case BUILT_IN_STPCPY_CHK: | |
2695 | if (lhs == NULL_TREE) | |
2696 | return; | |
2697 | else | |
2698 | { | |
2699 | tree lhsuint = fold_convert_loc (loc, size_type_node, lhs); | |
2700 | srclen = fold_convert_loc (loc, size_type_node, dst); | |
2701 | srclen = fold_build2_loc (loc, MINUS_EXPR, size_type_node, | |
2702 | lhsuint, srclen); | |
2703 | } | |
2704 | break; | |
2705 | default: | |
2706 | gcc_unreachable (); | |
2707 | } | |
2708 | ||
2709 | if (didx == 0) | |
2710 | { | |
2711 | didx = new_stridx (dst); | |
2712 | if (didx == 0) | |
2713 | return; | |
2714 | } | |
2715 | if (olddsi != NULL) | |
2716 | { | |
e3f9a279 | 2717 | oldlen = olddsi->nonzero_chars; |
8b57bfeb | 2718 | dsi = unshare_strinfo (olddsi); |
e3f9a279 RS |
2719 | dsi->nonzero_chars = srclen; |
2720 | dsi->full_string_p = (srclen != NULL_TREE); | |
8b57bfeb JJ |
2721 | /* Break the chain, so adjust_related_strinfo on later pointers in |
2722 | the chain won't adjust this one anymore. */ | |
2723 | dsi->next = 0; | |
2724 | dsi->stmt = NULL; | |
2725 | dsi->endptr = NULL_TREE; | |
2726 | } | |
2727 | else | |
2728 | { | |
e3f9a279 | 2729 | dsi = new_strinfo (dst, didx, srclen, srclen != NULL_TREE); |
8b57bfeb JJ |
2730 | set_strinfo (didx, dsi); |
2731 | find_equal_ptrs (dst, didx); | |
2732 | } | |
2733 | dsi->writable = true; | |
2734 | dsi->dont_invalidate = true; | |
2735 | ||
e3f9a279 | 2736 | if (dsi->nonzero_chars == NULL_TREE) |
8b57bfeb | 2737 | { |
526ceb68 | 2738 | strinfo *chainsi; |
93a90db6 | 2739 | |
8b57bfeb | 2740 | /* If string length of src is unknown, use delayed length |
dfea3d6f | 2741 | computation. If string length of dst will be needed, it |
8b57bfeb JJ |
2742 | can be computed by transforming this strcpy call into |
2743 | stpcpy and subtracting dst from the return value. */ | |
93a90db6 AK |
2744 | |
2745 | /* Look for earlier strings whose length could be determined if | |
2746 | this strcpy is turned into an stpcpy. */ | |
2747 | ||
2748 | if (dsi->prev != 0 && (chainsi = verify_related_strinfos (dsi)) != NULL) | |
2749 | { | |
2750 | for (; chainsi && chainsi != dsi; chainsi = get_strinfo (chainsi->next)) | |
2751 | { | |
2752 | /* When setting a stmt for delayed length computation | |
2753 | prevent all strinfos through dsi from being | |
2754 | invalidated. */ | |
2755 | chainsi = unshare_strinfo (chainsi); | |
2756 | chainsi->stmt = stmt; | |
e3f9a279 RS |
2757 | chainsi->nonzero_chars = NULL_TREE; |
2758 | chainsi->full_string_p = false; | |
93a90db6 AK |
2759 | chainsi->endptr = NULL_TREE; |
2760 | chainsi->dont_invalidate = true; | |
2761 | } | |
2762 | } | |
8b57bfeb | 2763 | dsi->stmt = stmt; |
cc8bea0a MS |
2764 | |
2765 | /* Try to detect overlap before returning. This catches cases | |
2766 | like strcpy (d, d + n) where n is non-constant whose range | |
2767 | is such that (n <= strlen (d) holds). | |
2768 | ||
2769 | OLDDSI->NONZERO_chars may have been reset by this point with | |
2770 | oldlen holding it original value. */ | |
2771 | if (olddsi && oldlen) | |
2772 | { | |
2773 | /* Add 1 for the terminating NUL. */ | |
2774 | tree type = TREE_TYPE (oldlen); | |
2775 | oldlen = fold_build2 (PLUS_EXPR, type, oldlen, | |
2776 | build_int_cst (type, 1)); | |
8a45b051 | 2777 | check_bounds_or_overlap (stmt, olddsi->ptr, src, oldlen, NULL_TREE); |
cc8bea0a MS |
2778 | } |
2779 | ||
8b57bfeb JJ |
2780 | return; |
2781 | } | |
2782 | ||
2783 | if (olddsi != NULL) | |
2784 | { | |
2785 | tree adj = NULL_TREE; | |
2786 | if (oldlen == NULL_TREE) | |
2787 | ; | |
2788 | else if (integer_zerop (oldlen)) | |
2789 | adj = srclen; | |
2790 | else if (TREE_CODE (oldlen) == INTEGER_CST | |
2791 | || TREE_CODE (srclen) == INTEGER_CST) | |
2792 | adj = fold_build2_loc (loc, MINUS_EXPR, | |
2793 | TREE_TYPE (srclen), srclen, | |
2794 | fold_convert_loc (loc, TREE_TYPE (srclen), | |
2795 | oldlen)); | |
2796 | if (adj != NULL_TREE) | |
2797 | adjust_related_strinfos (loc, dsi, adj); | |
2798 | else | |
2799 | dsi->prev = 0; | |
2800 | } | |
2801 | /* strcpy src may not overlap dst, so src doesn't need to be | |
2802 | invalidated either. */ | |
2803 | if (si != NULL) | |
2804 | si->dont_invalidate = true; | |
2805 | ||
2806 | fn = NULL_TREE; | |
2807 | zsi = NULL; | |
2808 | switch (bcode) | |
2809 | { | |
2810 | case BUILT_IN_STRCPY: | |
e79983f4 | 2811 | fn = builtin_decl_implicit (BUILT_IN_MEMCPY); |
8b57bfeb | 2812 | if (lhs) |
9771b263 | 2813 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] = didx; |
8b57bfeb JJ |
2814 | break; |
2815 | case BUILT_IN_STRCPY_CHK: | |
e79983f4 | 2816 | fn = builtin_decl_explicit (BUILT_IN_MEMCPY_CHK); |
8b57bfeb | 2817 | if (lhs) |
9771b263 | 2818 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] = didx; |
8b57bfeb JJ |
2819 | break; |
2820 | case BUILT_IN_STPCPY: | |
2821 | /* This would need adjustment of the lhs (subtract one), | |
2822 | or detection that the trailing '\0' doesn't need to be | |
2823 | written, if it will be immediately overwritten. | |
e79983f4 | 2824 | fn = builtin_decl_explicit (BUILT_IN_MEMPCPY); */ |
8b57bfeb JJ |
2825 | if (lhs) |
2826 | { | |
2827 | dsi->endptr = lhs; | |
2828 | zsi = zero_length_string (lhs, dsi); | |
2829 | } | |
2830 | break; | |
2831 | case BUILT_IN_STPCPY_CHK: | |
2832 | /* This would need adjustment of the lhs (subtract one), | |
2833 | or detection that the trailing '\0' doesn't need to be | |
2834 | written, if it will be immediately overwritten. | |
e79983f4 | 2835 | fn = builtin_decl_explicit (BUILT_IN_MEMPCPY_CHK); */ |
8b57bfeb JJ |
2836 | if (lhs) |
2837 | { | |
2838 | dsi->endptr = lhs; | |
2839 | zsi = zero_length_string (lhs, dsi); | |
2840 | } | |
2841 | break; | |
2842 | default: | |
2843 | gcc_unreachable (); | |
2844 | } | |
2845 | if (zsi != NULL) | |
2846 | zsi->dont_invalidate = true; | |
2847 | ||
cc8bea0a MS |
2848 | if (fn) |
2849 | { | |
2850 | tree args = TYPE_ARG_TYPES (TREE_TYPE (fn)); | |
2851 | type = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (args))); | |
2852 | } | |
2853 | else | |
2854 | type = size_type_node; | |
8b57bfeb JJ |
2855 | |
2856 | len = fold_convert_loc (loc, type, unshare_expr (srclen)); | |
2857 | len = fold_build2_loc (loc, PLUS_EXPR, type, len, build_int_cst (type, 1)); | |
cc8bea0a MS |
2858 | |
2859 | /* Set the no-warning bit on the transformed statement? */ | |
2860 | bool set_no_warning = false; | |
2861 | ||
2862 | if (const strinfo *chksi = olddsi ? olddsi : dsi) | |
2863 | if (si | |
213694e5 | 2864 | && check_bounds_or_overlap (stmt, chksi->ptr, si->ptr, NULL_TREE, len)) |
cc8bea0a MS |
2865 | { |
2866 | gimple_set_no_warning (stmt, true); | |
2867 | set_no_warning = true; | |
2868 | } | |
2869 | ||
2870 | if (fn == NULL_TREE) | |
2871 | return; | |
2872 | ||
8b57bfeb JJ |
2873 | len = force_gimple_operand_gsi (gsi, len, true, NULL_TREE, true, |
2874 | GSI_SAME_STMT); | |
2875 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
2876 | { | |
2877 | fprintf (dump_file, "Optimizing: "); | |
2878 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
2879 | } | |
31db0fe0 ML |
2880 | if (gimple_call_num_args (stmt) == 2) |
2881 | success = update_gimple_call (gsi, fn, 3, dst, src, len); | |
8b57bfeb | 2882 | else |
31db0fe0 ML |
2883 | success = update_gimple_call (gsi, fn, 4, dst, src, len, |
2884 | gimple_call_arg (stmt, 2)); | |
8b57bfeb JJ |
2885 | if (success) |
2886 | { | |
2887 | stmt = gsi_stmt (*gsi); | |
2888 | update_stmt (stmt); | |
2889 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
2890 | { | |
2891 | fprintf (dump_file, "into: "); | |
2892 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
2893 | } | |
2894 | /* Allow adjust_last_stmt to decrease this memcpy's size. */ | |
2895 | laststmt.stmt = stmt; | |
2896 | laststmt.len = srclen; | |
2897 | laststmt.stridx = dsi->idx; | |
2898 | } | |
2899 | else if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
2900 | fprintf (dump_file, "not possible.\n"); | |
cc8bea0a MS |
2901 | |
2902 | if (set_no_warning) | |
2903 | gimple_set_no_warning (stmt, true); | |
2904 | } | |
2905 | ||
2906 | /* Check the size argument to the built-in forms of stpncpy and strncpy | |
2907 | for out-of-bounds offsets or overlapping access, and to see if the | |
2908 | size argument is derived from a call to strlen() on the source argument, | |
2909 | and if so, issue an appropriate warning. */ | |
2910 | ||
2911 | static void | |
0a0de963 | 2912 | handle_builtin_strncat (built_in_function, gimple_stmt_iterator *gsi) |
cc8bea0a MS |
2913 | { |
2914 | /* Same as stxncpy(). */ | |
0a0de963 | 2915 | handle_builtin_stxncpy_strncat (true, gsi); |
8b57bfeb JJ |
2916 | } |
2917 | ||
025d57f0 MS |
2918 | /* Return true if LEN depends on a call to strlen(SRC) in an interesting |
2919 | way. LEN can either be an integer expression, or a pointer (to char). | |
d5029d45 | 2920 | When it is the latter (such as in recursive calls to self) it is |
025d57f0 MS |
2921 | assumed to be the argument in some call to strlen() whose relationship |
2922 | to SRC is being ascertained. */ | |
2923 | ||
4252ccd7 | 2924 | bool |
025d57f0 MS |
2925 | is_strlen_related_p (tree src, tree len) |
2926 | { | |
2927 | if (TREE_CODE (TREE_TYPE (len)) == POINTER_TYPE | |
2928 | && operand_equal_p (src, len, 0)) | |
2929 | return true; | |
2930 | ||
2931 | if (TREE_CODE (len) != SSA_NAME) | |
2932 | return false; | |
2933 | ||
ef29b12c MS |
2934 | if (TREE_CODE (src) == SSA_NAME) |
2935 | { | |
2936 | gimple *srcdef = SSA_NAME_DEF_STMT (src); | |
2937 | if (is_gimple_assign (srcdef)) | |
2938 | { | |
2939 | /* Handle bitwise AND used in conversions from wider size_t | |
2940 | to narrower unsigned types. */ | |
2941 | tree_code code = gimple_assign_rhs_code (srcdef); | |
2942 | if (code == BIT_AND_EXPR | |
2943 | || code == NOP_EXPR) | |
2944 | return is_strlen_related_p (gimple_assign_rhs1 (srcdef), len); | |
2945 | ||
2946 | return false; | |
2947 | } | |
2948 | ||
2949 | if (gimple_call_builtin_p (srcdef, BUILT_IN_NORMAL)) | |
2950 | { | |
2951 | /* If SRC is the result of a call to an allocation function | |
2952 | or strlen, use the function's argument instead. */ | |
2953 | tree func = gimple_call_fndecl (srcdef); | |
2954 | built_in_function code = DECL_FUNCTION_CODE (func); | |
2955 | if (code == BUILT_IN_ALLOCA | |
2956 | || code == BUILT_IN_ALLOCA_WITH_ALIGN | |
2957 | || code == BUILT_IN_MALLOC | |
2958 | || code == BUILT_IN_STRLEN) | |
2959 | return is_strlen_related_p (gimple_call_arg (srcdef, 0), len); | |
2960 | ||
2961 | /* FIXME: Handle other functions with attribute alloc_size. */ | |
2962 | return false; | |
2963 | } | |
2964 | } | |
2965 | ||
2966 | gimple *lendef = SSA_NAME_DEF_STMT (len); | |
2967 | if (!lendef) | |
025d57f0 MS |
2968 | return false; |
2969 | ||
ef29b12c | 2970 | if (is_gimple_call (lendef)) |
025d57f0 | 2971 | { |
ef29b12c MS |
2972 | tree func = gimple_call_fndecl (lendef); |
2973 | if (!valid_builtin_call (lendef) | |
025d57f0 MS |
2974 | || DECL_FUNCTION_CODE (func) != BUILT_IN_STRLEN) |
2975 | return false; | |
2976 | ||
ef29b12c | 2977 | tree arg = gimple_call_arg (lendef, 0); |
025d57f0 MS |
2978 | return is_strlen_related_p (src, arg); |
2979 | } | |
2980 | ||
ef29b12c | 2981 | if (!is_gimple_assign (lendef)) |
025d57f0 MS |
2982 | return false; |
2983 | ||
ef29b12c MS |
2984 | tree_code code = gimple_assign_rhs_code (lendef); |
2985 | tree rhs1 = gimple_assign_rhs1 (lendef); | |
025d57f0 MS |
2986 | tree rhstype = TREE_TYPE (rhs1); |
2987 | ||
2988 | if ((TREE_CODE (rhstype) == POINTER_TYPE && code == POINTER_PLUS_EXPR) | |
2989 | || (INTEGRAL_TYPE_P (rhstype) | |
2990 | && (code == BIT_AND_EXPR | |
2991 | || code == NOP_EXPR))) | |
2992 | { | |
4252ccd7 MS |
2993 | /* Pointer plus (an integer), and truncation are considered among |
2994 | the (potentially) related expressions to strlen. */ | |
025d57f0 MS |
2995 | return is_strlen_related_p (src, rhs1); |
2996 | } | |
2997 | ||
ef29b12c | 2998 | if (tree rhs2 = gimple_assign_rhs2 (lendef)) |
4252ccd7 MS |
2999 | { |
3000 | /* Integer subtraction is considered strlen-related when both | |
3001 | arguments are integers and second one is strlen-related. */ | |
3002 | rhstype = TREE_TYPE (rhs2); | |
3003 | if (INTEGRAL_TYPE_P (rhstype) && code == MINUS_EXPR) | |
3004 | return is_strlen_related_p (src, rhs2); | |
3005 | } | |
3006 | ||
025d57f0 MS |
3007 | return false; |
3008 | } | |
3009 | ||
0a0de963 MS |
3010 | /* Called by handle_builtin_stxncpy_strncat and by |
3011 | gimple_fold_builtin_strncpy in gimple-fold.c. | |
5d0d5d68 MS |
3012 | Check to see if the specified bound is a) equal to the size of |
3013 | the destination DST and if so, b) if it's immediately followed by | |
3014 | DST[CNT - 1] = '\0'. If a) holds and b) does not, warn. Otherwise, | |
3015 | do nothing. Return true if diagnostic has been issued. | |
025d57f0 MS |
3016 | |
3017 | The purpose is to diagnose calls to strncpy and stpncpy that do | |
3018 | not nul-terminate the copy while allowing for the idiom where | |
3019 | such a call is immediately followed by setting the last element | |
3020 | to nul, as in: | |
3021 | char a[32]; | |
3022 | strncpy (a, s, sizeof a); | |
3023 | a[sizeof a - 1] = '\0'; | |
3024 | */ | |
3025 | ||
5d0d5d68 | 3026 | bool |
025d57f0 MS |
3027 | maybe_diag_stxncpy_trunc (gimple_stmt_iterator gsi, tree src, tree cnt) |
3028 | { | |
025d57f0 | 3029 | gimple *stmt = gsi_stmt (gsi); |
e9b9fa4c MS |
3030 | if (gimple_no_warning_p (stmt)) |
3031 | return false; | |
025d57f0 MS |
3032 | |
3033 | wide_int cntrange[2]; | |
3034 | ||
3035 | if (TREE_CODE (cnt) == INTEGER_CST) | |
3036 | cntrange[0] = cntrange[1] = wi::to_wide (cnt); | |
3037 | else if (TREE_CODE (cnt) == SSA_NAME) | |
3038 | { | |
54994253 | 3039 | enum value_range_kind rng = get_range_info (cnt, cntrange, cntrange + 1); |
025d57f0 MS |
3040 | if (rng == VR_RANGE) |
3041 | ; | |
3042 | else if (rng == VR_ANTI_RANGE) | |
3043 | { | |
3044 | wide_int maxobjsize = wi::to_wide (TYPE_MAX_VALUE (ptrdiff_type_node)); | |
3045 | ||
3046 | if (wi::ltu_p (cntrange[1], maxobjsize)) | |
3047 | { | |
3048 | cntrange[0] = cntrange[1] + 1; | |
3049 | cntrange[1] = maxobjsize; | |
3050 | } | |
3051 | else | |
3052 | { | |
3053 | cntrange[1] = cntrange[0] - 1; | |
3054 | cntrange[0] = wi::zero (TYPE_PRECISION (TREE_TYPE (cnt))); | |
3055 | } | |
3056 | } | |
3057 | else | |
3058 | return false; | |
3059 | } | |
3060 | else | |
3061 | return false; | |
3062 | ||
3063 | /* Negative value is the constant string length. If it's less than | |
5d0d5d68 MS |
3064 | the lower bound there is no truncation. Avoid calling get_stridx() |
3065 | when ssa_ver_to_stridx is empty. That implies the caller isn't | |
3066 | running under the control of this pass and ssa_ver_to_stridx hasn't | |
3067 | been created yet. */ | |
3068 | int sidx = ssa_ver_to_stridx.length () ? get_stridx (src) : 0; | |
025d57f0 MS |
3069 | if (sidx < 0 && wi::gtu_p (cntrange[0], ~sidx)) |
3070 | return false; | |
3071 | ||
3072 | tree dst = gimple_call_arg (stmt, 0); | |
025d57f0 MS |
3073 | tree dstdecl = dst; |
3074 | if (TREE_CODE (dstdecl) == ADDR_EXPR) | |
3075 | dstdecl = TREE_OPERAND (dstdecl, 0); | |
3076 | ||
6a33d0ff | 3077 | tree ref = NULL_TREE; |
4252ccd7 MS |
3078 | |
3079 | if (!sidx) | |
3080 | { | |
3081 | /* If the source is a non-string return early to avoid warning | |
3082 | for possible truncation (if the truncation is certain SIDX | |
3083 | is non-zero). */ | |
3084 | tree srcdecl = gimple_call_arg (stmt, 1); | |
3085 | if (TREE_CODE (srcdecl) == ADDR_EXPR) | |
3086 | srcdecl = TREE_OPERAND (srcdecl, 0); | |
3087 | if (get_attr_nonstring_decl (srcdecl, &ref)) | |
3088 | return false; | |
3089 | } | |
3090 | ||
53b28abf | 3091 | /* Likewise, if the destination refers to an array/pointer declared |
4252ccd7 | 3092 | nonstring return early. */ |
6a33d0ff MS |
3093 | if (get_attr_nonstring_decl (dstdecl, &ref)) |
3094 | return false; | |
025d57f0 MS |
3095 | |
3096 | /* Look for dst[i] = '\0'; after the stxncpy() call and if found | |
3097 | avoid the truncation warning. */ | |
b25e5572 | 3098 | gsi_next_nondebug (&gsi); |
025d57f0 | 3099 | gimple *next_stmt = gsi_stmt (gsi); |
a76acaed MS |
3100 | if (!next_stmt) |
3101 | { | |
3102 | /* When there is no statement in the same basic block check | |
3103 | the immediate successor block. */ | |
3104 | if (basic_block bb = gimple_bb (stmt)) | |
3105 | { | |
3106 | if (single_succ_p (bb)) | |
3107 | { | |
3108 | /* For simplicity, ignore blocks with multiple outgoing | |
3109 | edges for now and only consider successor blocks along | |
3110 | normal edges. */ | |
3111 | edge e = EDGE_SUCC (bb, 0); | |
3112 | if (!(e->flags & EDGE_ABNORMAL)) | |
3113 | { | |
3114 | gsi = gsi_start_bb (e->dest); | |
3115 | next_stmt = gsi_stmt (gsi); | |
3116 | if (next_stmt && is_gimple_debug (next_stmt)) | |
3117 | { | |
3118 | gsi_next_nondebug (&gsi); | |
3119 | next_stmt = gsi_stmt (gsi); | |
3120 | } | |
3121 | } | |
3122 | } | |
3123 | } | |
3124 | } | |
025d57f0 | 3125 | |
a76acaed | 3126 | if (next_stmt && is_gimple_assign (next_stmt)) |
025d57f0 | 3127 | { |
025d57f0 | 3128 | tree lhs = gimple_assign_lhs (next_stmt); |
6a33d0ff MS |
3129 | tree_code code = TREE_CODE (lhs); |
3130 | if (code == ARRAY_REF || code == MEM_REF) | |
3131 | lhs = TREE_OPERAND (lhs, 0); | |
3132 | ||
3133 | tree func = gimple_call_fndecl (stmt); | |
3134 | if (DECL_FUNCTION_CODE (func) == BUILT_IN_STPNCPY) | |
3135 | { | |
3136 | tree ret = gimple_call_lhs (stmt); | |
3137 | if (ret && operand_equal_p (ret, lhs, 0)) | |
3138 | return false; | |
3139 | } | |
3140 | ||
3141 | /* Determine the base address and offset of the reference, | |
3142 | ignoring the innermost array index. */ | |
3143 | if (TREE_CODE (ref) == ARRAY_REF) | |
3144 | ref = TREE_OPERAND (ref, 0); | |
3145 | ||
a90c8804 | 3146 | poly_int64 dstoff; |
6a33d0ff MS |
3147 | tree dstbase = get_addr_base_and_unit_offset (ref, &dstoff); |
3148 | ||
a90c8804 | 3149 | poly_int64 lhsoff; |
6a33d0ff MS |
3150 | tree lhsbase = get_addr_base_and_unit_offset (lhs, &lhsoff); |
3151 | if (lhsbase | |
44e60df3 | 3152 | && dstbase |
a90c8804 | 3153 | && known_eq (dstoff, lhsoff) |
6a33d0ff | 3154 | && operand_equal_p (dstbase, lhsbase, 0)) |
025d57f0 MS |
3155 | return false; |
3156 | } | |
3157 | ||
3158 | int prec = TYPE_PRECISION (TREE_TYPE (cnt)); | |
3159 | wide_int lenrange[2]; | |
3160 | if (strinfo *sisrc = sidx > 0 ? get_strinfo (sidx) : NULL) | |
3161 | { | |
3162 | lenrange[0] = (sisrc->nonzero_chars | |
3163 | && TREE_CODE (sisrc->nonzero_chars) == INTEGER_CST | |
3164 | ? wi::to_wide (sisrc->nonzero_chars) | |
3165 | : wi::zero (prec)); | |
3166 | lenrange[1] = lenrange[0]; | |
3167 | } | |
3168 | else if (sidx < 0) | |
3169 | lenrange[0] = lenrange[1] = wi::shwi (~sidx, prec); | |
3170 | else | |
3171 | { | |
5d6655eb | 3172 | c_strlen_data lendata = { }; |
a7160771 MS |
3173 | /* Set MAXBOUND to an arbitrary non-null non-integer node as a request |
3174 | to have it set to the length of the longest string in a PHI. */ | |
3175 | lendata.maxbound = src; | |
5d6655eb MS |
3176 | get_range_strlen (src, &lendata, /* eltsize = */1); |
3177 | if (TREE_CODE (lendata.minlen) == INTEGER_CST | |
3178 | && TREE_CODE (lendata.maxbound) == INTEGER_CST) | |
025d57f0 | 3179 | { |
5d6655eb MS |
3180 | /* When LENDATA.MAXLEN is unknown, reset LENDATA.MINLEN |
3181 | which stores the length of the shortest known string. */ | |
3182 | if (integer_all_onesp (lendata.maxlen)) | |
3183 | lenrange[0] = wi::shwi (0, prec); | |
3184 | else | |
3185 | lenrange[0] = wi::to_wide (lendata.minlen, prec); | |
3186 | lenrange[1] = wi::to_wide (lendata.maxbound, prec); | |
025d57f0 MS |
3187 | } |
3188 | else | |
3189 | { | |
3190 | lenrange[0] = wi::shwi (0, prec); | |
3191 | lenrange[1] = wi::shwi (-1, prec); | |
3192 | } | |
3193 | } | |
3194 | ||
55ace4d1 | 3195 | location_t callloc = gimple_or_expr_nonartificial_location (stmt, dst); |
025d57f0 MS |
3196 | tree func = gimple_call_fndecl (stmt); |
3197 | ||
3198 | if (lenrange[0] != 0 || !wi::neg_p (lenrange[1])) | |
3199 | { | |
3200 | /* If the longest source string is shorter than the lower bound | |
3201 | of the specified count the copy is definitely nul-terminated. */ | |
3202 | if (wi::ltu_p (lenrange[1], cntrange[0])) | |
3203 | return false; | |
3204 | ||
3205 | if (wi::neg_p (lenrange[1])) | |
3206 | { | |
3207 | /* The length of one of the strings is unknown but at least | |
3208 | one has non-zero length and that length is stored in | |
3209 | LENRANGE[1]. Swap the bounds to force a "may be truncated" | |
3210 | warning below. */ | |
3211 | lenrange[1] = lenrange[0]; | |
3212 | lenrange[0] = wi::shwi (0, prec); | |
3213 | } | |
3214 | ||
eec5f615 MS |
3215 | /* Set to true for strncat whose bound is derived from the length |
3216 | of the destination (the expected usage pattern). */ | |
3217 | bool cat_dstlen_bounded = false; | |
3218 | if (DECL_FUNCTION_CODE (func) == BUILT_IN_STRNCAT) | |
3219 | cat_dstlen_bounded = is_strlen_related_p (dst, cnt); | |
3220 | ||
5d0d5d68 | 3221 | if (lenrange[0] == cntrange[1] && cntrange[0] == cntrange[1]) |
1c89478a MS |
3222 | return warning_n (callloc, OPT_Wstringop_truncation, |
3223 | cntrange[0].to_uhwi (), | |
3224 | "%G%qD output truncated before terminating " | |
3225 | "nul copying %E byte from a string of the " | |
3226 | "same length", | |
3227 | "%G%qD output truncated before terminating nul " | |
3228 | "copying %E bytes from a string of the same " | |
3229 | "length", | |
8a45b051 | 3230 | stmt, func, cnt); |
eec5f615 | 3231 | else if (!cat_dstlen_bounded) |
025d57f0 | 3232 | { |
eec5f615 MS |
3233 | if (wi::geu_p (lenrange[0], cntrange[1])) |
3234 | { | |
3235 | /* The shortest string is longer than the upper bound of | |
3236 | the count so the truncation is certain. */ | |
3237 | if (cntrange[0] == cntrange[1]) | |
3238 | return warning_n (callloc, OPT_Wstringop_truncation, | |
3239 | cntrange[0].to_uhwi (), | |
3240 | "%G%qD output truncated copying %E byte " | |
3241 | "from a string of length %wu", | |
3242 | "%G%qD output truncated copying %E bytes " | |
3243 | "from a string of length %wu", | |
8a45b051 | 3244 | stmt, func, cnt, lenrange[0].to_uhwi ()); |
eec5f615 MS |
3245 | |
3246 | return warning_at (callloc, OPT_Wstringop_truncation, | |
3247 | "%G%qD output truncated copying between %wu " | |
3248 | "and %wu bytes from a string of length %wu", | |
8a45b051 | 3249 | stmt, func, cntrange[0].to_uhwi (), |
eec5f615 MS |
3250 | cntrange[1].to_uhwi (), lenrange[0].to_uhwi ()); |
3251 | } | |
3252 | else if (wi::geu_p (lenrange[1], cntrange[1])) | |
3253 | { | |
3254 | /* The longest string is longer than the upper bound of | |
3255 | the count so the truncation is possible. */ | |
3256 | if (cntrange[0] == cntrange[1]) | |
3257 | return warning_n (callloc, OPT_Wstringop_truncation, | |
3258 | cntrange[0].to_uhwi (), | |
3259 | "%G%qD output may be truncated copying %E " | |
3260 | "byte from a string of length %wu", | |
3261 | "%G%qD output may be truncated copying %E " | |
3262 | "bytes from a string of length %wu", | |
8a45b051 | 3263 | stmt, func, cnt, lenrange[1].to_uhwi ()); |
eec5f615 MS |
3264 | |
3265 | return warning_at (callloc, OPT_Wstringop_truncation, | |
3266 | "%G%qD output may be truncated copying between " | |
3267 | "%wu and %wu bytes from a string of length %wu", | |
8a45b051 | 3268 | stmt, func, cntrange[0].to_uhwi (), |
eec5f615 MS |
3269 | cntrange[1].to_uhwi (), lenrange[1].to_uhwi ()); |
3270 | } | |
025d57f0 MS |
3271 | } |
3272 | ||
eec5f615 MS |
3273 | if (!cat_dstlen_bounded |
3274 | && cntrange[0] != cntrange[1] | |
025d57f0 MS |
3275 | && wi::leu_p (cntrange[0], lenrange[0]) |
3276 | && wi::leu_p (cntrange[1], lenrange[0] + 1)) | |
3277 | { | |
3278 | /* If the source (including the terminating nul) is longer than | |
3279 | the lower bound of the specified count but shorter than the | |
3280 | upper bound the copy may (but need not) be truncated. */ | |
3281 | return warning_at (callloc, OPT_Wstringop_truncation, | |
5d0d5d68 MS |
3282 | "%G%qD output may be truncated copying between " |
3283 | "%wu and %wu bytes from a string of length %wu", | |
8a45b051 | 3284 | stmt, func, cntrange[0].to_uhwi (), |
025d57f0 MS |
3285 | cntrange[1].to_uhwi (), lenrange[0].to_uhwi ()); |
3286 | } | |
3287 | } | |
3288 | ||
3289 | if (tree dstsize = compute_objsize (dst, 1)) | |
3290 | { | |
dfea3d6f | 3291 | /* The source length is unknown. Try to determine the destination |
025d57f0 MS |
3292 | size and see if it matches the specified bound. If not, bail. |
3293 | Otherwise go on to see if it should be diagnosed for possible | |
3294 | truncation. */ | |
3295 | if (!dstsize) | |
3296 | return false; | |
3297 | ||
3298 | if (wi::to_wide (dstsize) != cntrange[1]) | |
3299 | return false; | |
3300 | ||
3a03bffd MS |
3301 | /* Avoid warning for strncpy(a, b, N) calls where the following |
3302 | equalities hold: | |
3303 | N == sizeof a && N == sizeof b */ | |
3304 | if (tree srcsize = compute_objsize (src, 1)) | |
3305 | if (wi::to_wide (srcsize) == cntrange[1]) | |
3306 | return false; | |
3307 | ||
025d57f0 MS |
3308 | if (cntrange[0] == cntrange[1]) |
3309 | return warning_at (callloc, OPT_Wstringop_truncation, | |
5d0d5d68 | 3310 | "%G%qD specified bound %E equals destination size", |
8a45b051 | 3311 | stmt, func, cnt); |
025d57f0 MS |
3312 | } |
3313 | ||
3314 | return false; | |
3315 | } | |
3316 | ||
0a0de963 MS |
3317 | /* Check the arguments to the built-in forms of stpncpy, strncpy, and |
3318 | strncat, for out-of-bounds offsets or overlapping access, and to see | |
3319 | if the size is derived from calling strlen() on the source argument, | |
3320 | and if so, issue the appropriate warning. | |
3321 | APPEND_P is true for strncat. */ | |
025d57f0 MS |
3322 | |
3323 | static void | |
0a0de963 | 3324 | handle_builtin_stxncpy_strncat (bool append_p, gimple_stmt_iterator *gsi) |
025d57f0 | 3325 | { |
6a33d0ff MS |
3326 | if (!strlen_to_stridx) |
3327 | return; | |
3328 | ||
025d57f0 MS |
3329 | gimple *stmt = gsi_stmt (*gsi); |
3330 | ||
31db0fe0 ML |
3331 | tree dst = gimple_call_arg (stmt, 0); |
3332 | tree src = gimple_call_arg (stmt, 1); | |
3333 | tree len = gimple_call_arg (stmt, 2); | |
cc8bea0a MS |
3334 | tree dstsize = NULL_TREE, srcsize = NULL_TREE; |
3335 | ||
3336 | int didx = get_stridx (dst); | |
3337 | if (strinfo *sidst = didx > 0 ? get_strinfo (didx) : NULL) | |
3338 | { | |
e3ba46bd MS |
3339 | /* Compute the size of the destination string including the nul |
3340 | if it is known to be nul-terminated. */ | |
cc8bea0a MS |
3341 | if (sidst->nonzero_chars) |
3342 | { | |
e0748030 | 3343 | if (sidst->full_string_p) |
e3ba46bd MS |
3344 | { |
3345 | /* String is known to be nul-terminated. */ | |
3346 | tree type = TREE_TYPE (sidst->nonzero_chars); | |
3347 | dstsize = fold_build2 (PLUS_EXPR, type, sidst->nonzero_chars, | |
3348 | build_int_cst (type, 1)); | |
3349 | } | |
3350 | else | |
3351 | dstsize = sidst->nonzero_chars; | |
cc8bea0a | 3352 | } |
e3ba46bd | 3353 | |
cc8bea0a MS |
3354 | dst = sidst->ptr; |
3355 | } | |
3356 | ||
3357 | int sidx = get_stridx (src); | |
3358 | strinfo *sisrc = sidx > 0 ? get_strinfo (sidx) : NULL; | |
3359 | if (sisrc) | |
3360 | { | |
3361 | /* strncat() and strncpy() can modify the source string by writing | |
3362 | over the terminating nul so SISRC->DONT_INVALIDATE must be left | |
3363 | clear. */ | |
3364 | ||
e3ba46bd MS |
3365 | /* Compute the size of the source string including the terminating |
3366 | nul if its known to be nul-terminated. */ | |
cc8bea0a MS |
3367 | if (sisrc->nonzero_chars) |
3368 | { | |
e0748030 | 3369 | if (sisrc->full_string_p) |
e3ba46bd MS |
3370 | { |
3371 | tree type = TREE_TYPE (sisrc->nonzero_chars); | |
3372 | srcsize = fold_build2 (PLUS_EXPR, type, sisrc->nonzero_chars, | |
3373 | build_int_cst (type, 1)); | |
3374 | } | |
3375 | else | |
3376 | srcsize = sisrc->nonzero_chars; | |
cc8bea0a MS |
3377 | } |
3378 | ||
3379 | src = sisrc->ptr; | |
3380 | } | |
3381 | else | |
3382 | srcsize = NULL_TREE; | |
3383 | ||
213694e5 | 3384 | if (check_bounds_or_overlap (stmt, dst, src, dstsize, srcsize)) |
cc8bea0a MS |
3385 | { |
3386 | gimple_set_no_warning (stmt, true); | |
3387 | return; | |
3388 | } | |
025d57f0 MS |
3389 | |
3390 | /* If the length argument was computed from strlen(S) for some string | |
dfea3d6f | 3391 | S retrieve the strinfo index for the string (PSS->FIRST) along with |
025d57f0 | 3392 | the location of the strlen() call (PSS->SECOND). */ |
6a33d0ff | 3393 | stridx_strlenloc *pss = strlen_to_stridx->get (len); |
025d57f0 MS |
3394 | if (!pss || pss->first <= 0) |
3395 | { | |
3396 | if (maybe_diag_stxncpy_trunc (*gsi, src, len)) | |
3397 | gimple_set_no_warning (stmt, true); | |
3398 | ||
3399 | return; | |
3400 | } | |
3401 | ||
025d57f0 MS |
3402 | /* Retrieve the strinfo data for the string S that LEN was computed |
3403 | from as some function F of strlen (S) (i.e., LEN need not be equal | |
3404 | to strlen(S)). */ | |
3405 | strinfo *silen = get_strinfo (pss->first); | |
3406 | ||
55ace4d1 | 3407 | location_t callloc = gimple_or_expr_nonartificial_location (stmt, dst); |
025d57f0 MS |
3408 | |
3409 | tree func = gimple_call_fndecl (stmt); | |
3410 | ||
3411 | bool warned = false; | |
3412 | ||
3413 | /* When -Wstringop-truncation is set, try to determine truncation | |
3414 | before diagnosing possible overflow. Truncation is implied by | |
3415 | the LEN argument being equal to strlen(SRC), regardless of | |
3416 | whether its value is known. Otherwise, issue the more generic | |
3417 | -Wstringop-overflow which triggers for LEN arguments that in | |
3418 | any meaningful way depend on strlen(SRC). */ | |
0a0de963 MS |
3419 | if (!append_p |
3420 | && sisrc == silen | |
6a33d0ff MS |
3421 | && is_strlen_related_p (src, len) |
3422 | && warning_at (callloc, OPT_Wstringop_truncation, | |
5d0d5d68 | 3423 | "%G%qD output truncated before terminating nul " |
6a33d0ff | 3424 | "copying as many bytes from a string as its length", |
8a45b051 | 3425 | stmt, func)) |
6a33d0ff | 3426 | warned = true; |
025d57f0 MS |
3427 | else if (silen && is_strlen_related_p (src, silen->ptr)) |
3428 | warned = warning_at (callloc, OPT_Wstringop_overflow_, | |
5d0d5d68 MS |
3429 | "%G%qD specified bound depends on the length " |
3430 | "of the source argument", | |
8a45b051 | 3431 | stmt, func); |
025d57f0 MS |
3432 | if (warned) |
3433 | { | |
3434 | location_t strlenloc = pss->second; | |
3435 | if (strlenloc != UNKNOWN_LOCATION && strlenloc != callloc) | |
3436 | inform (strlenloc, "length computed here"); | |
3437 | } | |
3438 | } | |
3439 | ||
8b57bfeb JJ |
3440 | /* Handle a memcpy-like ({mem{,p}cpy,__mem{,p}cpy_chk}) call. |
3441 | If strlen of the second argument is known and length of the third argument | |
3442 | is that plus one, strlen of the first argument is the same after this | |
ef29b12c | 3443 | call. Uses RVALS to determine range information. */ |
8b57bfeb JJ |
3444 | |
3445 | static void | |
ef29b12c MS |
3446 | handle_builtin_memcpy (enum built_in_function bcode, gimple_stmt_iterator *gsi, |
3447 | const vr_values *rvals) | |
8b57bfeb | 3448 | { |
ef29b12c | 3449 | tree lhs, oldlen, newlen; |
355fe088 | 3450 | gimple *stmt = gsi_stmt (*gsi); |
ef29b12c | 3451 | strinfo *si, *dsi; |
8b57bfeb | 3452 | |
ef29b12c MS |
3453 | tree len = gimple_call_arg (stmt, 2); |
3454 | tree src = gimple_call_arg (stmt, 1); | |
3455 | tree dst = gimple_call_arg (stmt, 0); | |
8b57bfeb | 3456 | |
ef29b12c MS |
3457 | int didx = get_stridx (dst); |
3458 | strinfo *olddsi = NULL; | |
8b57bfeb JJ |
3459 | if (didx > 0) |
3460 | olddsi = get_strinfo (didx); | |
3461 | else if (didx < 0) | |
3462 | return; | |
3463 | ||
3464 | if (olddsi != NULL | |
8b57bfeb | 3465 | && !integer_zerop (len)) |
ef29b12c MS |
3466 | { |
3467 | maybe_warn_overflow (stmt, len, rvals, olddsi, false, true); | |
3468 | adjust_last_stmt (olddsi, stmt, false); | |
3469 | } | |
3470 | ||
3471 | int idx = get_stridx (src); | |
3472 | if (idx == 0) | |
3473 | return; | |
8b57bfeb | 3474 | |
e3f9a279 | 3475 | bool full_string_p; |
8b57bfeb JJ |
3476 | if (idx > 0) |
3477 | { | |
355fe088 | 3478 | gimple *def_stmt; |
8b57bfeb | 3479 | |
e3f9a279 RS |
3480 | /* Handle memcpy (x, y, l) where l's relationship with strlen (y) |
3481 | is known. */ | |
8b57bfeb | 3482 | si = get_strinfo (idx); |
e3f9a279 | 3483 | if (si == NULL || si->nonzero_chars == NULL_TREE) |
8b57bfeb | 3484 | return; |
e3f9a279 RS |
3485 | if (TREE_CODE (len) == INTEGER_CST |
3486 | && TREE_CODE (si->nonzero_chars) == INTEGER_CST) | |
3487 | { | |
3488 | if (tree_int_cst_le (len, si->nonzero_chars)) | |
3489 | { | |
3490 | /* Copying LEN nonzero characters, where LEN is constant. */ | |
3491 | newlen = len; | |
3492 | full_string_p = false; | |
3493 | } | |
3494 | else | |
3495 | { | |
3496 | /* Copying the whole of the analyzed part of SI. */ | |
3497 | newlen = si->nonzero_chars; | |
3498 | full_string_p = si->full_string_p; | |
3499 | } | |
3500 | } | |
3501 | else | |
3502 | { | |
3503 | if (!si->full_string_p) | |
3504 | return; | |
3505 | if (TREE_CODE (len) != SSA_NAME) | |
3506 | return; | |
3507 | def_stmt = SSA_NAME_DEF_STMT (len); | |
3508 | if (!is_gimple_assign (def_stmt) | |
3509 | || gimple_assign_rhs_code (def_stmt) != PLUS_EXPR | |
3510 | || gimple_assign_rhs1 (def_stmt) != si->nonzero_chars | |
3511 | || !integer_onep (gimple_assign_rhs2 (def_stmt))) | |
3512 | return; | |
3513 | /* Copying variable-length string SI (and no more). */ | |
3514 | newlen = si->nonzero_chars; | |
3515 | full_string_p = true; | |
3516 | } | |
8b57bfeb JJ |
3517 | } |
3518 | else | |
3519 | { | |
3520 | si = NULL; | |
3521 | /* Handle memcpy (x, "abcd", 5) or | |
3522 | memcpy (x, "abc\0uvw", 7). */ | |
e3f9a279 | 3523 | if (!tree_fits_uhwi_p (len)) |
8b57bfeb | 3524 | return; |
e3f9a279 RS |
3525 | |
3526 | unsigned HOST_WIDE_INT clen = tree_to_uhwi (len); | |
3527 | unsigned HOST_WIDE_INT nonzero_chars = ~idx; | |
3528 | newlen = build_int_cst (size_type_node, MIN (nonzero_chars, clen)); | |
3529 | full_string_p = clen > nonzero_chars; | |
8b57bfeb JJ |
3530 | } |
3531 | ||
aca8570e MS |
3532 | if (!full_string_p |
3533 | && olddsi | |
3534 | && olddsi->nonzero_chars | |
3535 | && TREE_CODE (olddsi->nonzero_chars) == INTEGER_CST | |
3536 | && tree_int_cst_le (newlen, olddsi->nonzero_chars)) | |
3537 | { | |
3538 | /* The SRC substring being written strictly overlaps | |
3539 | a subsequence of the existing string OLDDSI. */ | |
3540 | newlen = olddsi->nonzero_chars; | |
3541 | full_string_p = olddsi->full_string_p; | |
3542 | } | |
3543 | ||
8b57bfeb JJ |
3544 | if (olddsi != NULL && TREE_CODE (len) == SSA_NAME) |
3545 | adjust_last_stmt (olddsi, stmt, false); | |
3546 | ||
3547 | if (didx == 0) | |
3548 | { | |
3549 | didx = new_stridx (dst); | |
3550 | if (didx == 0) | |
3551 | return; | |
3552 | } | |
8b57bfeb JJ |
3553 | oldlen = NULL_TREE; |
3554 | if (olddsi != NULL) | |
3555 | { | |
3556 | dsi = unshare_strinfo (olddsi); | |
e3f9a279 RS |
3557 | oldlen = olddsi->nonzero_chars; |
3558 | dsi->nonzero_chars = newlen; | |
3559 | dsi->full_string_p = full_string_p; | |
8b57bfeb JJ |
3560 | /* Break the chain, so adjust_related_strinfo on later pointers in |
3561 | the chain won't adjust this one anymore. */ | |
3562 | dsi->next = 0; | |
3563 | dsi->stmt = NULL; | |
3564 | dsi->endptr = NULL_TREE; | |
3565 | } | |
3566 | else | |
3567 | { | |
e3f9a279 | 3568 | dsi = new_strinfo (dst, didx, newlen, full_string_p); |
8b57bfeb JJ |
3569 | set_strinfo (didx, dsi); |
3570 | find_equal_ptrs (dst, didx); | |
3571 | } | |
3572 | dsi->writable = true; | |
3573 | dsi->dont_invalidate = true; | |
3574 | if (olddsi != NULL) | |
3575 | { | |
3576 | tree adj = NULL_TREE; | |
3577 | location_t loc = gimple_location (stmt); | |
3578 | if (oldlen == NULL_TREE) | |
3579 | ; | |
3580 | else if (integer_zerop (oldlen)) | |
e3f9a279 | 3581 | adj = newlen; |
8b57bfeb | 3582 | else if (TREE_CODE (oldlen) == INTEGER_CST |
e3f9a279 RS |
3583 | || TREE_CODE (newlen) == INTEGER_CST) |
3584 | adj = fold_build2_loc (loc, MINUS_EXPR, TREE_TYPE (newlen), newlen, | |
3585 | fold_convert_loc (loc, TREE_TYPE (newlen), | |
8b57bfeb JJ |
3586 | oldlen)); |
3587 | if (adj != NULL_TREE) | |
3588 | adjust_related_strinfos (loc, dsi, adj); | |
3589 | else | |
3590 | dsi->prev = 0; | |
3591 | } | |
3592 | /* memcpy src may not overlap dst, so src doesn't need to be | |
3593 | invalidated either. */ | |
3594 | if (si != NULL) | |
3595 | si->dont_invalidate = true; | |
3596 | ||
e3f9a279 | 3597 | if (full_string_p) |
8b57bfeb | 3598 | { |
e3f9a279 RS |
3599 | lhs = gimple_call_lhs (stmt); |
3600 | switch (bcode) | |
3601 | { | |
3602 | case BUILT_IN_MEMCPY: | |
3603 | case BUILT_IN_MEMCPY_CHK: | |
e3f9a279 RS |
3604 | /* Allow adjust_last_stmt to decrease this memcpy's size. */ |
3605 | laststmt.stmt = stmt; | |
3606 | laststmt.len = dsi->nonzero_chars; | |
3607 | laststmt.stridx = dsi->idx; | |
3608 | if (lhs) | |
3609 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] = didx; | |
3610 | break; | |
3611 | case BUILT_IN_MEMPCPY: | |
3612 | case BUILT_IN_MEMPCPY_CHK: | |
e3f9a279 RS |
3613 | break; |
3614 | default: | |
3615 | gcc_unreachable (); | |
3616 | } | |
8b57bfeb JJ |
3617 | } |
3618 | } | |
3619 | ||
3620 | /* Handle a strcat-like ({strcat,__strcat_chk}) call. | |
3621 | If strlen of the second argument is known, strlen of the first argument | |
3622 | is increased by the length of the second argument. Furthermore, attempt | |
3623 | to convert it to memcpy/strcpy if the length of the first argument | |
3624 | is known. */ | |
3625 | ||
3626 | static void | |
3627 | handle_builtin_strcat (enum built_in_function bcode, gimple_stmt_iterator *gsi) | |
3628 | { | |
3629 | int idx, didx; | |
cc8bea0a | 3630 | tree srclen, args, type, fn, objsz, endptr; |
8b57bfeb | 3631 | bool success; |
355fe088 | 3632 | gimple *stmt = gsi_stmt (*gsi); |
526ceb68 | 3633 | strinfo *si, *dsi; |
cc8bea0a | 3634 | location_t loc = gimple_location (stmt); |
8b57bfeb | 3635 | |
31db0fe0 | 3636 | tree src = gimple_call_arg (stmt, 1); |
cc8bea0a MS |
3637 | tree dst = gimple_call_arg (stmt, 0); |
3638 | ||
3639 | /* Bail if the source is the same as destination. It will be diagnosed | |
3640 | elsewhere. */ | |
3641 | if (operand_equal_p (src, dst, 0)) | |
3642 | return; | |
3643 | ||
3644 | tree lhs = gimple_call_lhs (stmt); | |
8b57bfeb JJ |
3645 | |
3646 | didx = get_stridx (dst); | |
3647 | if (didx < 0) | |
3648 | return; | |
3649 | ||
3650 | dsi = NULL; | |
3651 | if (didx > 0) | |
3652 | dsi = get_strinfo (didx); | |
cc8bea0a MS |
3653 | |
3654 | srclen = NULL_TREE; | |
3655 | si = NULL; | |
3656 | idx = get_stridx (src); | |
3657 | if (idx < 0) | |
3658 | srclen = build_int_cst (size_type_node, ~idx); | |
3659 | else if (idx > 0) | |
3660 | { | |
3661 | si = get_strinfo (idx); | |
3662 | if (si != NULL) | |
3663 | srclen = get_string_length (si); | |
3664 | } | |
3665 | ||
3666 | /* Set the no-warning bit on the transformed statement? */ | |
3667 | bool set_no_warning = false; | |
3668 | ||
8b57bfeb JJ |
3669 | if (dsi == NULL || get_string_length (dsi) == NULL_TREE) |
3670 | { | |
cc8bea0a MS |
3671 | { |
3672 | /* The concatenation always involves copying at least one byte | |
3673 | (the terminating nul), even if the source string is empty. | |
3674 | If the source is unknown assume it's one character long and | |
3675 | used that as both sizes. */ | |
3676 | tree slen = srclen; | |
3677 | if (slen) | |
3678 | { | |
3679 | tree type = TREE_TYPE (slen); | |
3680 | slen = fold_build2 (PLUS_EXPR, type, slen, build_int_cst (type, 1)); | |
3681 | } | |
3682 | ||
3683 | tree sptr = si && si->ptr ? si->ptr : src; | |
3684 | ||
213694e5 | 3685 | if (check_bounds_or_overlap (stmt, dst, sptr, NULL_TREE, slen)) |
cc8bea0a MS |
3686 | { |
3687 | gimple_set_no_warning (stmt, true); | |
3688 | set_no_warning = true; | |
3689 | } | |
3690 | } | |
3691 | ||
8b57bfeb | 3692 | /* strcat (p, q) can be transformed into |
cc8bea0a | 3693 | tmp = p + strlen (p); endptr = stpcpy (tmp, q); |
8b57bfeb JJ |
3694 | with length endptr - p if we need to compute the length |
3695 | later on. Don't do this transformation if we don't need | |
3696 | it. */ | |
e79983f4 | 3697 | if (builtin_decl_implicit_p (BUILT_IN_STPCPY) && lhs == NULL_TREE) |
8b57bfeb JJ |
3698 | { |
3699 | if (didx == 0) | |
3700 | { | |
3701 | didx = new_stridx (dst); | |
3702 | if (didx == 0) | |
3703 | return; | |
3704 | } | |
3705 | if (dsi == NULL) | |
3706 | { | |
e3f9a279 | 3707 | dsi = new_strinfo (dst, didx, NULL_TREE, false); |
8b57bfeb JJ |
3708 | set_strinfo (didx, dsi); |
3709 | find_equal_ptrs (dst, didx); | |
3710 | } | |
3711 | else | |
3712 | { | |
3713 | dsi = unshare_strinfo (dsi); | |
e3f9a279 RS |
3714 | dsi->nonzero_chars = NULL_TREE; |
3715 | dsi->full_string_p = false; | |
8b57bfeb JJ |
3716 | dsi->next = 0; |
3717 | dsi->endptr = NULL_TREE; | |
3718 | } | |
3719 | dsi->writable = true; | |
3720 | dsi->stmt = stmt; | |
3721 | dsi->dont_invalidate = true; | |
3722 | } | |
3723 | return; | |
3724 | } | |
3725 | ||
cc8bea0a | 3726 | tree dstlen = dsi->nonzero_chars; |
8b57bfeb JJ |
3727 | endptr = dsi->endptr; |
3728 | ||
3729 | dsi = unshare_strinfo (dsi); | |
3730 | dsi->endptr = NULL_TREE; | |
3731 | dsi->stmt = NULL; | |
3732 | dsi->writable = true; | |
3733 | ||
3734 | if (srclen != NULL_TREE) | |
3735 | { | |
e3f9a279 RS |
3736 | dsi->nonzero_chars = fold_build2_loc (loc, PLUS_EXPR, |
3737 | TREE_TYPE (dsi->nonzero_chars), | |
3738 | dsi->nonzero_chars, srclen); | |
3739 | gcc_assert (dsi->full_string_p); | |
8b57bfeb JJ |
3740 | adjust_related_strinfos (loc, dsi, srclen); |
3741 | dsi->dont_invalidate = true; | |
3742 | } | |
3743 | else | |
3744 | { | |
e3f9a279 RS |
3745 | dsi->nonzero_chars = NULL; |
3746 | dsi->full_string_p = false; | |
e79983f4 | 3747 | if (lhs == NULL_TREE && builtin_decl_implicit_p (BUILT_IN_STPCPY)) |
8b57bfeb JJ |
3748 | dsi->dont_invalidate = true; |
3749 | } | |
3750 | ||
3751 | if (si != NULL) | |
3752 | /* strcat src may not overlap dst, so src doesn't need to be | |
3753 | invalidated either. */ | |
3754 | si->dont_invalidate = true; | |
3755 | ||
3756 | /* For now. Could remove the lhs from the call and add | |
3757 | lhs = dst; afterwards. */ | |
3758 | if (lhs) | |
3759 | return; | |
3760 | ||
3761 | fn = NULL_TREE; | |
3762 | objsz = NULL_TREE; | |
3763 | switch (bcode) | |
3764 | { | |
3765 | case BUILT_IN_STRCAT: | |
3766 | if (srclen != NULL_TREE) | |
e79983f4 | 3767 | fn = builtin_decl_implicit (BUILT_IN_MEMCPY); |
8b57bfeb | 3768 | else |
e79983f4 | 3769 | fn = builtin_decl_implicit (BUILT_IN_STRCPY); |
8b57bfeb JJ |
3770 | break; |
3771 | case BUILT_IN_STRCAT_CHK: | |
3772 | if (srclen != NULL_TREE) | |
e79983f4 | 3773 | fn = builtin_decl_explicit (BUILT_IN_MEMCPY_CHK); |
8b57bfeb | 3774 | else |
e79983f4 | 3775 | fn = builtin_decl_explicit (BUILT_IN_STRCPY_CHK); |
31db0fe0 | 3776 | objsz = gimple_call_arg (stmt, 2); |
8b57bfeb JJ |
3777 | break; |
3778 | default: | |
3779 | gcc_unreachable (); | |
3780 | } | |
3781 | ||
3782 | if (fn == NULL_TREE) | |
3783 | return; | |
3784 | ||
cc8bea0a MS |
3785 | if (dsi && dstlen) |
3786 | { | |
3787 | tree type = TREE_TYPE (dstlen); | |
3788 | ||
3789 | /* Compute the size of the source sequence, including the nul. */ | |
3790 | tree srcsize = srclen ? srclen : size_zero_node; | |
6889a3ac MS |
3791 | tree one = build_int_cst (type, 1); |
3792 | srcsize = fold_build2 (PLUS_EXPR, type, srcsize, one); | |
3793 | tree dstsize = fold_build2 (PLUS_EXPR, type, dstlen, one); | |
cc8bea0a MS |
3794 | tree sptr = si && si->ptr ? si->ptr : src; |
3795 | ||
6889a3ac | 3796 | if (check_bounds_or_overlap (stmt, dst, sptr, dstsize, srcsize)) |
cc8bea0a MS |
3797 | { |
3798 | gimple_set_no_warning (stmt, true); | |
3799 | set_no_warning = true; | |
3800 | } | |
3801 | } | |
3802 | ||
3803 | tree len = NULL_TREE; | |
8b57bfeb JJ |
3804 | if (srclen != NULL_TREE) |
3805 | { | |
3806 | args = TYPE_ARG_TYPES (TREE_TYPE (fn)); | |
3807 | type = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (args))); | |
3808 | ||
3809 | len = fold_convert_loc (loc, type, unshare_expr (srclen)); | |
3810 | len = fold_build2_loc (loc, PLUS_EXPR, type, len, | |
3811 | build_int_cst (type, 1)); | |
3812 | len = force_gimple_operand_gsi (gsi, len, true, NULL_TREE, true, | |
3813 | GSI_SAME_STMT); | |
3814 | } | |
3815 | if (endptr) | |
3816 | dst = fold_convert_loc (loc, TREE_TYPE (dst), unshare_expr (endptr)); | |
3817 | else | |
770fe3a3 | 3818 | dst = fold_build2_loc (loc, POINTER_PLUS_EXPR, TREE_TYPE (dst), dst, |
8b57bfeb JJ |
3819 | fold_convert_loc (loc, sizetype, |
3820 | unshare_expr (dstlen))); | |
3821 | dst = force_gimple_operand_gsi (gsi, dst, true, NULL_TREE, true, | |
3822 | GSI_SAME_STMT); | |
770fe3a3 BE |
3823 | if (objsz) |
3824 | { | |
3825 | objsz = fold_build2_loc (loc, MINUS_EXPR, TREE_TYPE (objsz), objsz, | |
3826 | fold_convert_loc (loc, TREE_TYPE (objsz), | |
3827 | unshare_expr (dstlen))); | |
3828 | objsz = force_gimple_operand_gsi (gsi, objsz, true, NULL_TREE, true, | |
3829 | GSI_SAME_STMT); | |
3830 | } | |
8b57bfeb JJ |
3831 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) |
3832 | { | |
3833 | fprintf (dump_file, "Optimizing: "); | |
3834 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
3835 | } | |
31db0fe0 ML |
3836 | if (srclen != NULL_TREE) |
3837 | success = update_gimple_call (gsi, fn, 3 + (objsz != NULL_TREE), | |
3838 | dst, src, len, objsz); | |
8b57bfeb | 3839 | else |
31db0fe0 ML |
3840 | success = update_gimple_call (gsi, fn, 2 + (objsz != NULL_TREE), |
3841 | dst, src, objsz); | |
8b57bfeb JJ |
3842 | if (success) |
3843 | { | |
3844 | stmt = gsi_stmt (*gsi); | |
3845 | update_stmt (stmt); | |
3846 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
3847 | { | |
3848 | fprintf (dump_file, "into: "); | |
3849 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
3850 | } | |
3851 | /* If srclen == NULL, note that current string length can be | |
3852 | computed by transforming this strcpy into stpcpy. */ | |
3853 | if (srclen == NULL_TREE && dsi->dont_invalidate) | |
3854 | dsi->stmt = stmt; | |
3855 | adjust_last_stmt (dsi, stmt, true); | |
3856 | if (srclen != NULL_TREE) | |
3857 | { | |
3858 | laststmt.stmt = stmt; | |
3859 | laststmt.len = srclen; | |
3860 | laststmt.stridx = dsi->idx; | |
3861 | } | |
3862 | } | |
3863 | else if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
3864 | fprintf (dump_file, "not possible.\n"); | |
cc8bea0a MS |
3865 | |
3866 | if (set_no_warning) | |
3867 | gimple_set_no_warning (stmt, true); | |
8b57bfeb JJ |
3868 | } |
3869 | ||
ef29b12c MS |
3870 | /* Handle a call to an allocation function like alloca, malloc or calloc, |
3871 | or an ordinary allocation function declared with attribute alloc_size. */ | |
24314386 MG |
3872 | |
3873 | static void | |
ef29b12c | 3874 | handle_alloc_call (enum built_in_function bcode, gimple_stmt_iterator *gsi) |
24314386 | 3875 | { |
355fe088 | 3876 | gimple *stmt = gsi_stmt (*gsi); |
24314386 | 3877 | tree lhs = gimple_call_lhs (stmt); |
a71dcca8 ML |
3878 | if (lhs == NULL_TREE) |
3879 | return; | |
3880 | ||
24314386 MG |
3881 | gcc_assert (get_stridx (lhs) == 0); |
3882 | int idx = new_stridx (lhs); | |
3883 | tree length = NULL_TREE; | |
3884 | if (bcode == BUILT_IN_CALLOC) | |
3885 | length = build_int_cst (size_type_node, 0); | |
e3f9a279 | 3886 | strinfo *si = new_strinfo (lhs, idx, length, length != NULL_TREE); |
24314386 | 3887 | if (bcode == BUILT_IN_CALLOC) |
ef29b12c MS |
3888 | { |
3889 | /* Only set STMT for calloc and malloc. */ | |
3890 | si->stmt = stmt; | |
3891 | /* Only set ENDPTR for calloc. */ | |
3892 | si->endptr = lhs; | |
3893 | } | |
3894 | else if (bcode == BUILT_IN_MALLOC) | |
3895 | si->stmt = stmt; | |
3896 | ||
3897 | /* Set ALLOC is set for all allocation functions. */ | |
3898 | si->alloc = stmt; | |
24314386 MG |
3899 | set_strinfo (idx, si); |
3900 | si->writable = true; | |
24314386 MG |
3901 | si->dont_invalidate = true; |
3902 | } | |
3903 | ||
3904 | /* Handle a call to memset. | |
3905 | After a call to calloc, memset(,0,) is unnecessary. | |
21722777 | 3906 | memset(malloc(n),0,n) is calloc(n,1). |
ef29b12c MS |
3907 | return true when the call is transformed, false otherwise. |
3908 | When nonnull uses RVALS to determine range information. */ | |
24314386 MG |
3909 | |
3910 | static bool | |
ef29b12c MS |
3911 | handle_builtin_memset (gimple_stmt_iterator *gsi, bool *zero_write, |
3912 | const vr_values *rvals) | |
24314386 | 3913 | { |
ef29b12c MS |
3914 | gimple *memset_stmt = gsi_stmt (*gsi); |
3915 | tree ptr = gimple_call_arg (memset_stmt, 0); | |
3916 | /* Set to the non-constant offset added to PTR. */ | |
3917 | wide_int offrng[2]; | |
3918 | int idx1 = get_stridx (ptr, offrng, rvals); | |
24314386 | 3919 | if (idx1 <= 0) |
8b0b334a | 3920 | return false; |
526ceb68 | 3921 | strinfo *si1 = get_strinfo (idx1); |
24314386 | 3922 | if (!si1) |
8b0b334a | 3923 | return false; |
ef29b12c MS |
3924 | gimple *alloc_stmt = si1->alloc; |
3925 | if (!alloc_stmt || !is_gimple_call (alloc_stmt)) | |
3926 | return false; | |
3927 | tree callee1 = gimple_call_fndecl (alloc_stmt); | |
3928 | if (!valid_builtin_call (alloc_stmt)) | |
3929 | return false; | |
3930 | tree alloc_size = gimple_call_arg (alloc_stmt, 0); | |
3931 | tree memset_size = gimple_call_arg (memset_stmt, 2); | |
3932 | ||
3933 | /* Check for overflow. */ | |
3934 | maybe_warn_overflow (memset_stmt, memset_size, rvals, NULL, false, true); | |
3935 | ||
3936 | /* Bail when there is no statement associated with the destination | |
3937 | (the statement may be null even when SI1->ALLOC is not). */ | |
3938 | if (!si1->stmt) | |
3939 | return false; | |
3940 | ||
3941 | /* Avoid optimizing if store is at a variable offset from the beginning | |
3942 | of the allocated object. */ | |
3943 | if (offrng[0] != 0 || offrng[0] != offrng[1]) | |
8b0b334a | 3944 | return false; |
ef29b12c MS |
3945 | |
3946 | /* Bail when the call writes a non-zero value. */ | |
3947 | if (!integer_zerop (gimple_call_arg (memset_stmt, 1))) | |
8b0b334a | 3948 | return false; |
ef29b12c MS |
3949 | |
3950 | /* Let the caller know the memset call cleared the destination. */ | |
3951 | *zero_write = true; | |
3952 | ||
24314386 | 3953 | enum built_in_function code1 = DECL_FUNCTION_CODE (callee1); |
24314386 | 3954 | if (code1 == BUILT_IN_CALLOC) |
ef29b12c | 3955 | /* Not touching alloc_stmt */ ; |
24314386 | 3956 | else if (code1 == BUILT_IN_MALLOC |
ef29b12c | 3957 | && operand_equal_p (memset_size, alloc_size, 0)) |
24314386 | 3958 | { |
ef29b12c MS |
3959 | /* Replace the malloc + memset calls with calloc. */ |
3960 | gimple_stmt_iterator gsi1 = gsi_for_stmt (si1->stmt); | |
24314386 | 3961 | update_gimple_call (&gsi1, builtin_decl_implicit (BUILT_IN_CALLOC), 2, |
ef29b12c | 3962 | alloc_size, build_one_cst (size_type_node)); |
e3f9a279 RS |
3963 | si1->nonzero_chars = build_int_cst (size_type_node, 0); |
3964 | si1->full_string_p = true; | |
20cb2258 | 3965 | si1->stmt = gsi_stmt (gsi1); |
24314386 MG |
3966 | } |
3967 | else | |
8b0b334a | 3968 | return false; |
ef29b12c MS |
3969 | tree lhs = gimple_call_lhs (memset_stmt); |
3970 | unlink_stmt_vdef (memset_stmt); | |
24314386 MG |
3971 | if (lhs) |
3972 | { | |
355fe088 | 3973 | gimple *assign = gimple_build_assign (lhs, ptr); |
24314386 MG |
3974 | gsi_replace (gsi, assign, false); |
3975 | } | |
3976 | else | |
3977 | { | |
3978 | gsi_remove (gsi, true); | |
ef29b12c | 3979 | release_defs (memset_stmt); |
24314386 MG |
3980 | } |
3981 | ||
8b0b334a | 3982 | return true; |
24314386 MG |
3983 | } |
3984 | ||
a7160771 MS |
3985 | /* Return a pointer to the first such equality expression if RES is used |
3986 | only in expressions testing its equality to zero, and null otherwise. */ | |
36b85e43 | 3987 | |
a7160771 MS |
3988 | static gimple * |
3989 | used_only_for_zero_equality (tree res) | |
36b85e43 | 3990 | { |
a7160771 MS |
3991 | gimple *first_use = NULL; |
3992 | ||
36b85e43 BS |
3993 | use_operand_p use_p; |
3994 | imm_use_iterator iter; | |
3995 | ||
36b85e43 BS |
3996 | FOR_EACH_IMM_USE_FAST (use_p, iter, res) |
3997 | { | |
a7160771 | 3998 | gimple *use_stmt = USE_STMT (use_p); |
36b85e43 | 3999 | |
a7160771 MS |
4000 | if (is_gimple_debug (use_stmt)) |
4001 | continue; | |
4002 | if (gimple_code (use_stmt) == GIMPLE_ASSIGN) | |
36b85e43 | 4003 | { |
a7160771 MS |
4004 | tree_code code = gimple_assign_rhs_code (use_stmt); |
4005 | if (code == COND_EXPR) | |
4006 | { | |
4007 | tree cond_expr = gimple_assign_rhs1 (use_stmt); | |
4008 | if ((TREE_CODE (cond_expr) != EQ_EXPR | |
4009 | && (TREE_CODE (cond_expr) != NE_EXPR)) | |
4010 | || !integer_zerop (TREE_OPERAND (cond_expr, 1))) | |
4011 | return NULL; | |
4012 | } | |
4013 | else if (code == EQ_EXPR || code == NE_EXPR) | |
4014 | { | |
4015 | if (!integer_zerop (gimple_assign_rhs2 (use_stmt))) | |
4016 | return NULL; | |
4017 | } | |
4018 | else | |
4019 | return NULL; | |
36b85e43 | 4020 | } |
a7160771 | 4021 | else if (gimple_code (use_stmt) == GIMPLE_COND) |
36b85e43 | 4022 | { |
a7160771 | 4023 | tree_code code = gimple_cond_code (use_stmt); |
36b85e43 | 4024 | if ((code != EQ_EXPR && code != NE_EXPR) |
a7160771 MS |
4025 | || !integer_zerop (gimple_cond_rhs (use_stmt))) |
4026 | return NULL; | |
36b85e43 BS |
4027 | } |
4028 | else | |
a7160771 MS |
4029 | return NULL; |
4030 | ||
4031 | if (!first_use) | |
4032 | first_use = use_stmt; | |
36b85e43 BS |
4033 | } |
4034 | ||
a7160771 MS |
4035 | return first_use; |
4036 | } | |
4037 | ||
4038 | /* Handle a call to memcmp. We try to handle small comparisons by | |
4039 | converting them to load and compare, and replacing the call to memcmp | |
4040 | with a __builtin_memcmp_eq call where possible. | |
4041 | return true when call is transformed, return false otherwise. */ | |
4042 | ||
4043 | static bool | |
4044 | handle_builtin_memcmp (gimple_stmt_iterator *gsi) | |
4045 | { | |
4046 | gcall *stmt = as_a <gcall *> (gsi_stmt (*gsi)); | |
4047 | tree res = gimple_call_lhs (stmt); | |
4048 | ||
4049 | if (!res || !used_only_for_zero_equality (res)) | |
4050 | return false; | |
4051 | ||
4052 | tree arg1 = gimple_call_arg (stmt, 0); | |
4053 | tree arg2 = gimple_call_arg (stmt, 1); | |
4054 | tree len = gimple_call_arg (stmt, 2); | |
4055 | unsigned HOST_WIDE_INT leni; | |
4056 | ||
36b85e43 BS |
4057 | if (tree_fits_uhwi_p (len) |
4058 | && (leni = tree_to_uhwi (len)) <= GET_MODE_SIZE (word_mode) | |
146ec50f | 4059 | && pow2p_hwi (leni)) |
36b85e43 BS |
4060 | { |
4061 | leni *= CHAR_TYPE_SIZE; | |
4062 | unsigned align1 = get_pointer_alignment (arg1); | |
4063 | unsigned align2 = get_pointer_alignment (arg2); | |
4064 | unsigned align = MIN (align1, align2); | |
fffbab82 RS |
4065 | scalar_int_mode mode; |
4066 | if (int_mode_for_size (leni, 1).exists (&mode) | |
e0bd6c9f | 4067 | && (align >= leni || !targetm.slow_unaligned_access (mode, align))) |
36b85e43 | 4068 | { |
a7160771 | 4069 | location_t loc = gimple_location (stmt); |
36b85e43 BS |
4070 | tree type, off; |
4071 | type = build_nonstandard_integer_type (leni, 1); | |
73a699ae | 4072 | gcc_assert (known_eq (GET_MODE_BITSIZE (TYPE_MODE (type)), leni)); |
36b85e43 BS |
4073 | tree ptrtype = build_pointer_type_for_mode (char_type_node, |
4074 | ptr_mode, true); | |
4075 | off = build_int_cst (ptrtype, 0); | |
4076 | arg1 = build2_loc (loc, MEM_REF, type, arg1, off); | |
4077 | arg2 = build2_loc (loc, MEM_REF, type, arg2, off); | |
4078 | tree tem1 = fold_const_aggregate_ref (arg1); | |
4079 | if (tem1) | |
4080 | arg1 = tem1; | |
4081 | tree tem2 = fold_const_aggregate_ref (arg2); | |
4082 | if (tem2) | |
4083 | arg2 = tem2; | |
4084 | res = fold_convert_loc (loc, TREE_TYPE (res), | |
4085 | fold_build2_loc (loc, NE_EXPR, | |
4086 | boolean_type_node, | |
4087 | arg1, arg2)); | |
4088 | gimplify_and_update_call_from_tree (gsi, res); | |
8b0b334a | 4089 | return true; |
36b85e43 BS |
4090 | } |
4091 | } | |
4092 | ||
a7160771 | 4093 | gimple_call_set_fndecl (stmt, builtin_decl_explicit (BUILT_IN_MEMCMP_EQ)); |
8b0b334a QZ |
4094 | return true; |
4095 | } | |
4096 | ||
e7868dc6 MS |
4097 | /* Given strinfo IDX for ARG, sets LENRNG[] to the range of lengths |
4098 | of the string(s) referenced by ARG if it can be determined. | |
4099 | If the length cannot be determined, sets *SIZE to the size of | |
a7160771 | 4100 | the array the string is stored in, if any. If no such array is |
e7868dc6 MS |
4101 | known, sets *SIZE to -1. When the strings are nul-terminated sets |
4102 | *NULTERM to true, otherwise to false. When nonnull uses RVALS to | |
4103 | determine range information. Returns true on success. */ | |
8b0b334a QZ |
4104 | |
4105 | static bool | |
a7160771 | 4106 | get_len_or_size (tree arg, int idx, unsigned HOST_WIDE_INT lenrng[2], |
e7868dc6 MS |
4107 | unsigned HOST_WIDE_INT *size, bool *nulterm, |
4108 | const vr_values *rvals) | |
8b0b334a | 4109 | { |
e7868dc6 | 4110 | /* Invalidate. */ |
a7160771 | 4111 | *size = HOST_WIDE_INT_M1U; |
8b0b334a | 4112 | |
a7160771 | 4113 | if (idx < 0) |
8b0b334a | 4114 | { |
a7160771 MS |
4115 | /* IDX is the inverted constant string length. */ |
4116 | lenrng[0] = ~idx; | |
4117 | lenrng[1] = lenrng[0]; | |
4118 | *nulterm = true; | |
e7868dc6 | 4119 | return true; |
8b0b334a | 4120 | } |
e7868dc6 MS |
4121 | |
4122 | /* Set so that both LEN and ~LEN are invalid lengths, i.e., maximum | |
4123 | possible length + 1. */ | |
4124 | lenrng[0] = lenrng[1] = HOST_WIDE_INT_MAX; | |
4125 | ||
4126 | if (strinfo *si = idx ? get_strinfo (idx) : NULL) | |
21722777 | 4127 | { |
e7868dc6 | 4128 | /* FIXME: Handle all this in_range_strlen_dynamic. */ |
a7160771 | 4129 | if (!si->nonzero_chars) |
e7868dc6 | 4130 | ; |
a7160771 MS |
4131 | else if (tree_fits_uhwi_p (si->nonzero_chars)) |
4132 | { | |
4133 | lenrng[0] = tree_to_uhwi (si->nonzero_chars); | |
4134 | *nulterm = si->full_string_p; | |
4135 | /* Set the upper bound only if the string is known to be | |
4136 | nul-terminated, otherwise leave it at maximum + 1. */ | |
4137 | if (*nulterm) | |
4138 | lenrng[1] = lenrng[0]; | |
4139 | } | |
4140 | else if (TREE_CODE (si->nonzero_chars) == SSA_NAME) | |
4141 | { | |
4142 | wide_int min, max; | |
4143 | value_range_kind rng = get_range_info (si->nonzero_chars, &min, &max); | |
4144 | if (rng == VR_RANGE) | |
4145 | { | |
4146 | lenrng[0] = min.to_uhwi (); | |
4147 | lenrng[1] = max.to_uhwi (); | |
4148 | *nulterm = si->full_string_p; | |
4149 | } | |
4150 | } | |
a7160771 | 4151 | } |
8b0b334a | 4152 | |
e7868dc6 MS |
4153 | if (lenrng[0] != HOST_WIDE_INT_MAX) |
4154 | return true; | |
4155 | ||
4156 | /* Compute the minimum and maximum real or possible lengths. */ | |
4157 | c_strlen_data lendata = { }; | |
4158 | /* Set MAXBOUND to an arbitrary non-null non-integer node as a request | |
4159 | to have it set to the length of the longest string in a PHI. */ | |
4160 | lendata.maxbound = arg; | |
4161 | get_range_strlen_dynamic (arg, &lendata, rvals); | |
4162 | ||
4163 | unsigned HOST_WIDE_INT maxbound = HOST_WIDE_INT_M1U; | |
4164 | if (tree_fits_uhwi_p (lendata.maxbound) | |
4165 | && !integer_all_onesp (lendata.maxbound)) | |
4166 | maxbound = tree_to_uhwi (lendata.maxbound); | |
4167 | ||
4168 | if (tree_fits_uhwi_p (lendata.minlen) && tree_fits_uhwi_p (lendata.maxlen)) | |
a7160771 | 4169 | { |
e7868dc6 MS |
4170 | unsigned HOST_WIDE_INT minlen = tree_to_uhwi (lendata.minlen); |
4171 | unsigned HOST_WIDE_INT maxlen = tree_to_uhwi (lendata.maxlen); | |
4172 | ||
4173 | /* The longest string in this data model. */ | |
4174 | const unsigned HOST_WIDE_INT lenmax | |
4175 | = tree_to_uhwi (max_object_size ()) - 2; | |
4176 | ||
4177 | if (maxbound == HOST_WIDE_INT_M1U) | |
21722777 | 4178 | { |
e7868dc6 MS |
4179 | lenrng[0] = minlen; |
4180 | lenrng[1] = maxlen; | |
4181 | *nulterm = minlen == maxlen; | |
8b0b334a | 4182 | } |
e7868dc6 | 4183 | else if (maxlen < lenmax) |
8b0b334a | 4184 | { |
e7868dc6 | 4185 | *size = maxbound + 1; |
a7160771 | 4186 | *nulterm = false; |
8b0b334a | 4187 | } |
e7868dc6 MS |
4188 | else |
4189 | return false; | |
4190 | ||
4191 | return true; | |
8b0b334a | 4192 | } |
21722777 | 4193 | |
e7868dc6 MS |
4194 | if (maxbound != HOST_WIDE_INT_M1U |
4195 | && lendata.maxlen | |
4196 | && !integer_all_onesp (lendata.maxlen)) | |
4197 | { | |
4198 | /* Set *SIZE to LENDATA.MAXBOUND which is a conservative estimate | |
4199 | of the longest string based on the sizes of the arrays referenced | |
4200 | by ARG. */ | |
4201 | *size = maxbound + 1; | |
4202 | *nulterm = false; | |
4203 | return true; | |
4204 | } | |
4205 | ||
4206 | return false; | |
a7160771 MS |
4207 | } |
4208 | ||
4209 | /* If IDX1 and IDX2 refer to strings A and B of unequal lengths, return | |
4210 | the result of 0 == strncmp (A, B, BOUND) (which is the same as strcmp | |
4211 | for a sufficiently large BOUND). If the result is based on the length | |
4212 | of one string being greater than the longest string that would fit in | |
4213 | the array pointer to by the argument, set *PLEN and *PSIZE to | |
4214 | the corresponding length (or its complement when the string is known | |
4215 | to be at least as long and need not be nul-terminated) and size. | |
4216 | Otherwise return null. */ | |
4217 | ||
4218 | static tree | |
4219 | strxcmp_eqz_result (tree arg1, int idx1, tree arg2, int idx2, | |
4220 | unsigned HOST_WIDE_INT bound, unsigned HOST_WIDE_INT len[2], | |
e7868dc6 | 4221 | unsigned HOST_WIDE_INT *psize, const vr_values *rvals) |
a7160771 MS |
4222 | { |
4223 | /* Determine the range the length of each string is in and whether it's | |
4224 | known to be nul-terminated, or the size of the array it's stored in. */ | |
4225 | bool nul1, nul2; | |
4226 | unsigned HOST_WIDE_INT siz1, siz2; | |
4227 | unsigned HOST_WIDE_INT len1rng[2], len2rng[2]; | |
e7868dc6 MS |
4228 | if (!get_len_or_size (arg1, idx1, len1rng, &siz1, &nul1, rvals) |
4229 | || !get_len_or_size (arg2, idx2, len2rng, &siz2, &nul2, rvals)) | |
a7160771 MS |
4230 | return NULL_TREE; |
4231 | ||
4232 | /* BOUND is set to HWI_M1U for strcmp and less to strncmp, and LENiRNG | |
4233 | to HWI_MAX when invalid. Adjust the length of each string to consider | |
4234 | to be no more than BOUND. */ | |
4235 | if (len1rng[0] < HOST_WIDE_INT_MAX && len1rng[0] > bound) | |
4236 | len1rng[0] = bound; | |
4237 | if (len1rng[1] < HOST_WIDE_INT_MAX && len1rng[1] > bound) | |
4238 | len1rng[1] = bound; | |
4239 | if (len2rng[0] < HOST_WIDE_INT_MAX && len2rng[0] > bound) | |
4240 | len2rng[0] = bound; | |
4241 | if (len2rng[1] < HOST_WIDE_INT_MAX && len2rng[1] > bound) | |
4242 | len2rng[1] = bound; | |
4243 | ||
4244 | /* Two empty strings are equal. */ | |
4245 | if (len1rng[1] == 0 && len2rng[1] == 0) | |
4246 | return integer_one_node; | |
4247 | ||
4248 | /* The strings are definitely unequal when the lower bound of the length | |
4249 | of one of them is greater than the length of the longest string that | |
4250 | would fit into the other array. */ | |
4251 | if (len1rng[0] == HOST_WIDE_INT_MAX | |
4252 | && len2rng[0] != HOST_WIDE_INT_MAX | |
4253 | && ((len2rng[0] < bound && len2rng[0] >= siz1) | |
4254 | || len2rng[0] > siz1)) | |
4255 | { | |
4256 | *psize = siz1; | |
4257 | len[0] = len1rng[0]; | |
4258 | /* Set LEN[0] to the lower bound of ARG1's length when it's | |
4259 | nul-terminated or to the complement of its minimum length | |
4260 | otherwise, */ | |
4261 | len[1] = nul2 ? len2rng[0] : ~len2rng[0]; | |
4262 | return integer_zero_node; | |
4263 | } | |
4264 | ||
4265 | if (len2rng[0] == HOST_WIDE_INT_MAX | |
4266 | && len1rng[0] != HOST_WIDE_INT_MAX | |
4267 | && ((len1rng[0] < bound && len1rng[0] >= siz2) | |
4268 | || len1rng[0] > siz2)) | |
4269 | { | |
4270 | *psize = siz2; | |
4271 | len[0] = nul1 ? len1rng[0] : ~len1rng[0]; | |
4272 | len[1] = len2rng[0]; | |
4273 | return integer_zero_node; | |
4274 | } | |
4275 | ||
4276 | /* The strings are also definitely unequal when their lengths are unequal | |
4277 | and at least one is nul-terminated. */ | |
4278 | if (len1rng[0] != HOST_WIDE_INT_MAX | |
4279 | && len2rng[0] != HOST_WIDE_INT_MAX | |
4280 | && ((len1rng[1] < len2rng[0] && nul1) | |
4281 | || (len2rng[1] < len1rng[0] && nul2))) | |
4282 | { | |
4283 | if (bound <= len1rng[0] || bound <= len2rng[0]) | |
4284 | *psize = bound; | |
4285 | else | |
4286 | *psize = HOST_WIDE_INT_M1U; | |
4287 | ||
4288 | len[0] = len1rng[0]; | |
4289 | len[1] = len2rng[0]; | |
4290 | return integer_zero_node; | |
8b0b334a QZ |
4291 | } |
4292 | ||
a7160771 MS |
4293 | /* The string lengths may be equal or unequal. Even when equal and |
4294 | both strings nul-terminated, without the string contents there's | |
4295 | no way to determine whether they are equal. */ | |
4296 | return NULL_TREE; | |
4297 | } | |
4298 | ||
4299 | /* Diagnose pointless calls to strcmp or strncmp STMT with string | |
4300 | arguments of lengths LEN or size SIZ and (for strncmp) BOUND, | |
4301 | whose result is used in equality expressions that evaluate to | |
4302 | a constant due to one argument being longer than the size of | |
4303 | the other. */ | |
21722777 | 4304 | |
a7160771 MS |
4305 | static void |
4306 | maybe_warn_pointless_strcmp (gimple *stmt, HOST_WIDE_INT bound, | |
4307 | unsigned HOST_WIDE_INT len[2], | |
4308 | unsigned HOST_WIDE_INT siz) | |
4309 | { | |
27c14dbc MS |
4310 | tree lhs = gimple_call_lhs (stmt); |
4311 | gimple *use = used_only_for_zero_equality (lhs); | |
a7160771 MS |
4312 | if (!use) |
4313 | return; | |
4314 | ||
4315 | bool at_least = false; | |
4316 | ||
4317 | /* Excessive LEN[i] indicates a lower bound. */ | |
4318 | if (len[0] > HOST_WIDE_INT_MAX) | |
8b0b334a | 4319 | { |
a7160771 MS |
4320 | at_least = true; |
4321 | len[0] = ~len[0]; | |
21722777 | 4322 | } |
a7160771 MS |
4323 | |
4324 | if (len[1] > HOST_WIDE_INT_MAX) | |
8b0b334a | 4325 | { |
a7160771 MS |
4326 | at_least = true; |
4327 | len[1] = ~len[1]; | |
21722777 | 4328 | } |
8b0b334a | 4329 | |
a7160771 | 4330 | unsigned HOST_WIDE_INT minlen = MIN (len[0], len[1]); |
21722777 | 4331 | |
a7160771 MS |
4332 | /* FIXME: Include a note pointing to the declaration of the smaller |
4333 | array. */ | |
55ace4d1 | 4334 | location_t stmt_loc = gimple_or_expr_nonartificial_location (stmt, lhs); |
27c14dbc | 4335 | |
a7160771 MS |
4336 | tree callee = gimple_call_fndecl (stmt); |
4337 | bool warned = false; | |
4338 | if (siz <= minlen && bound == -1) | |
4339 | warned = warning_at (stmt_loc, OPT_Wstring_compare, | |
4340 | (at_least | |
4341 | ? G_("%G%qD of a string of length %wu or more and " | |
4342 | "an array of size %wu evaluates to nonzero") | |
4343 | : G_("%G%qD of a string of length %wu and an array " | |
4344 | "of size %wu evaluates to nonzero")), | |
4345 | stmt, callee, minlen, siz); | |
4346 | else if (!at_least && siz <= HOST_WIDE_INT_MAX) | |
4347 | { | |
4348 | if (len[0] != HOST_WIDE_INT_MAX && len[1] != HOST_WIDE_INT_MAX) | |
4349 | warned = warning_at (stmt_loc, OPT_Wstring_compare, | |
4350 | "%G%qD of strings of length %wu and %wu " | |
4351 | "and bound of %wu evaluates to nonzero", | |
4352 | stmt, callee, len[0], len[1], bound); | |
4353 | else | |
4354 | warned = warning_at (stmt_loc, OPT_Wstring_compare, | |
4355 | "%G%qD of a string of length %wu, an array " | |
4356 | "of size %wu and bound of %wu evaluates to " | |
4357 | "nonzero", | |
4358 | stmt, callee, minlen, siz, bound); | |
4359 | } | |
4360 | ||
4361 | if (warned) | |
4362 | { | |
4363 | location_t use_loc = gimple_location (use); | |
4364 | if (LOCATION_LINE (stmt_loc) != LOCATION_LINE (use_loc)) | |
4365 | inform (use_loc, "in this expression"); | |
4366 | } | |
4367 | } | |
8b0b334a | 4368 | |
21722777 | 4369 | |
a7160771 MS |
4370 | /* Optimize a call to strcmp or strncmp either by folding it to a constant |
4371 | when possible or by transforming the latter to the former. Warn about | |
4372 | calls where the length of one argument is greater than the size of | |
4373 | the array to which the other argument points if the latter's length | |
4374 | is not known. Return true when the call has been transformed into | |
4375 | another and false otherwise. */ | |
4376 | ||
4377 | static bool | |
e7868dc6 | 4378 | handle_builtin_string_cmp (gimple_stmt_iterator *gsi, const vr_values *rvals) |
a7160771 MS |
4379 | { |
4380 | gcall *stmt = as_a <gcall *> (gsi_stmt (*gsi)); | |
4381 | tree lhs = gimple_call_lhs (stmt); | |
8b0b334a | 4382 | |
a7160771 | 4383 | if (!lhs) |
8b0b334a QZ |
4384 | return false; |
4385 | ||
a7160771 MS |
4386 | tree arg1 = gimple_call_arg (stmt, 0); |
4387 | tree arg2 = gimple_call_arg (stmt, 1); | |
4388 | int idx1 = get_stridx (arg1); | |
4389 | int idx2 = get_stridx (arg2); | |
8b0b334a | 4390 | |
700d4cb0 | 4391 | /* For strncmp set to the value of the third argument if known. */ |
a7160771 | 4392 | HOST_WIDE_INT bound = -1; |
b5338fb3 | 4393 | tree len = NULL_TREE; |
a7160771 MS |
4394 | /* Extract the strncmp bound. */ |
4395 | if (gimple_call_num_args (stmt) == 3) | |
8b0b334a | 4396 | { |
b5338fb3 | 4397 | len = gimple_call_arg (stmt, 2); |
a7160771 MS |
4398 | if (tree_fits_shwi_p (len)) |
4399 | bound = tree_to_shwi (len); | |
4400 | ||
4401 | /* If the bound argument is NOT known, do nothing. */ | |
4402 | if (bound < 0) | |
8b0b334a | 4403 | return false; |
8b0b334a | 4404 | } |
a7160771 | 4405 | |
b5338fb3 MS |
4406 | /* Avoid folding if either argument is not a nul-terminated array. |
4407 | Defer warning until later. */ | |
4408 | if (!check_nul_terminated_array (NULL_TREE, arg1, len) | |
4409 | || !check_nul_terminated_array (NULL_TREE, arg2, len)) | |
4410 | return false; | |
4411 | ||
a7160771 MS |
4412 | { |
4413 | /* Set to the length of one argument (or its complement if it's | |
4414 | the lower bound of a range) and the size of the array storing | |
4415 | the other if the result is based on the former being equal to | |
4416 | or greater than the latter. */ | |
4417 | unsigned HOST_WIDE_INT len[2] = { HOST_WIDE_INT_MAX, HOST_WIDE_INT_MAX }; | |
4418 | unsigned HOST_WIDE_INT siz = HOST_WIDE_INT_M1U; | |
4419 | ||
4420 | /* Try to determine if the two strings are either definitely equal | |
4421 | or definitely unequal and if so, either fold the result to zero | |
4422 | (when equal) or set the range of the result to ~[0, 0] otherwise. */ | |
4423 | if (tree eqz = strxcmp_eqz_result (arg1, idx1, arg2, idx2, bound, | |
e7868dc6 | 4424 | len, &siz, rvals)) |
a7160771 MS |
4425 | { |
4426 | if (integer_zerop (eqz)) | |
4427 | { | |
4428 | maybe_warn_pointless_strcmp (stmt, bound, len, siz); | |
4429 | ||
4430 | /* When the lengths of the first two string arguments are | |
4431 | known to be unequal set the range of the result to non-zero. | |
4432 | This allows the call to be eliminated if its result is only | |
4433 | used in tests for equality to zero. */ | |
4434 | wide_int zero = wi::zero (TYPE_PRECISION (TREE_TYPE (lhs))); | |
4435 | set_range_info (lhs, VR_ANTI_RANGE, zero, zero); | |
4436 | return false; | |
4437 | } | |
4438 | /* When the two strings are definitely equal (such as when they | |
4439 | are both empty) fold the call to the constant result. */ | |
4440 | replace_call_with_value (gsi, integer_zero_node); | |
4441 | return true; | |
4442 | } | |
4443 | } | |
4444 | ||
4445 | /* Return if nothing is known about the strings pointed to by ARG1 | |
4446 | and ARG2. */ | |
4447 | if (idx1 == 0 && idx2 == 0) | |
4448 | return false; | |
4449 | ||
4450 | /* Determine either the length or the size of each of the strings, | |
4451 | whichever is available. */ | |
4452 | HOST_WIDE_INT cstlen1 = -1, cstlen2 = -1; | |
4453 | HOST_WIDE_INT arysiz1 = -1, arysiz2 = -1; | |
4454 | ||
e7868dc6 MS |
4455 | { |
4456 | unsigned HOST_WIDE_INT len1rng[2], len2rng[2]; | |
4457 | unsigned HOST_WIDE_INT arsz1, arsz2; | |
4458 | bool nulterm[2]; | |
4459 | ||
4460 | if (!get_len_or_size (arg1, idx1, len1rng, &arsz1, nulterm, rvals) | |
4461 | || !get_len_or_size (arg2, idx2, len2rng, &arsz2, nulterm + 1, rvals)) | |
4462 | return false; | |
4463 | ||
4464 | if (len1rng[0] == len1rng[1] && len1rng[0] < HOST_WIDE_INT_MAX) | |
4465 | cstlen1 = len1rng[0]; | |
4466 | else if (arsz1 < HOST_WIDE_INT_M1U) | |
4467 | arysiz1 = arsz1; | |
4468 | ||
4469 | if (len2rng[0] == len2rng[1] && len2rng[0] < HOST_WIDE_INT_MAX) | |
4470 | cstlen2 = len2rng[0]; | |
4471 | else if (arsz2 < HOST_WIDE_INT_M1U) | |
4472 | arysiz2 = arsz2; | |
4473 | } | |
a7160771 MS |
4474 | |
4475 | /* Bail if neither the string length nor the size of the array | |
4476 | it is stored in can be determined. */ | |
e7868dc6 MS |
4477 | if ((cstlen1 < 0 && arysiz1 < 0) |
4478 | || (cstlen2 < 0 && arysiz2 < 0) | |
4479 | || (cstlen1 < 0 && cstlen2 < 0)) | |
9c233ad0 MS |
4480 | return false; |
4481 | ||
4482 | if (cstlen1 >= 0) | |
4483 | ++cstlen1; | |
4484 | if (cstlen2 >= 0) | |
4485 | ++cstlen2; | |
4486 | ||
a7160771 MS |
4487 | /* The exact number of characters to compare. */ |
4488 | HOST_WIDE_INT cmpsiz = bound < 0 ? cstlen1 < 0 ? cstlen2 : cstlen1 : bound; | |
4489 | /* The size of the array in which the unknown string is stored. */ | |
4490 | HOST_WIDE_INT varsiz = arysiz1 < 0 ? arysiz2 : arysiz1; | |
4491 | ||
4492 | if (cmpsiz < varsiz && used_only_for_zero_equality (lhs)) | |
4493 | { | |
4494 | /* If the known length is less than the size of the other array | |
4495 | and the strcmp result is only used to test equality to zero, | |
4496 | transform the call to the equivalent _eq call. */ | |
4497 | if (tree fn = builtin_decl_implicit (bound < 0 ? BUILT_IN_STRCMP_EQ | |
4498 | : BUILT_IN_STRNCMP_EQ)) | |
4499 | { | |
4500 | tree n = build_int_cst (size_type_node, cmpsiz); | |
4501 | update_gimple_call (gsi, fn, 3, arg1, arg2, n); | |
4502 | return true; | |
4503 | } | |
4504 | } | |
4505 | ||
4506 | return false; | |
36b85e43 BS |
4507 | } |
4508 | ||
8b57bfeb JJ |
4509 | /* Handle a POINTER_PLUS_EXPR statement. |
4510 | For p = "abcd" + 2; compute associated length, or if | |
4511 | p = q + off is pointing to a '\0' character of a string, call | |
4512 | zero_length_string on it. */ | |
4513 | ||
4514 | static void | |
4515 | handle_pointer_plus (gimple_stmt_iterator *gsi) | |
4516 | { | |
355fe088 | 4517 | gimple *stmt = gsi_stmt (*gsi); |
8b57bfeb JJ |
4518 | tree lhs = gimple_assign_lhs (stmt), off; |
4519 | int idx = get_stridx (gimple_assign_rhs1 (stmt)); | |
526ceb68 | 4520 | strinfo *si, *zsi; |
8b57bfeb JJ |
4521 | |
4522 | if (idx == 0) | |
4523 | return; | |
4524 | ||
4525 | if (idx < 0) | |
4526 | { | |
4527 | tree off = gimple_assign_rhs2 (stmt); | |
cc269bb6 | 4528 | if (tree_fits_uhwi_p (off) |
7d362f6c | 4529 | && tree_to_uhwi (off) <= (unsigned HOST_WIDE_INT) ~idx) |
9771b263 | 4530 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] |
ae7e9ddd | 4531 | = ~(~idx - (int) tree_to_uhwi (off)); |
8b57bfeb JJ |
4532 | return; |
4533 | } | |
4534 | ||
4535 | si = get_strinfo (idx); | |
e3f9a279 | 4536 | if (si == NULL || si->nonzero_chars == NULL_TREE) |
8b57bfeb JJ |
4537 | return; |
4538 | ||
4539 | off = gimple_assign_rhs2 (stmt); | |
4540 | zsi = NULL; | |
e3f9a279 | 4541 | if (si->full_string_p && operand_equal_p (si->nonzero_chars, off, 0)) |
8b57bfeb JJ |
4542 | zsi = zero_length_string (lhs, si); |
4543 | else if (TREE_CODE (off) == SSA_NAME) | |
4544 | { | |
355fe088 | 4545 | gimple *def_stmt = SSA_NAME_DEF_STMT (off); |
8b57bfeb | 4546 | if (gimple_assign_single_p (def_stmt) |
e3f9a279 RS |
4547 | && si->full_string_p |
4548 | && operand_equal_p (si->nonzero_chars, | |
4549 | gimple_assign_rhs1 (def_stmt), 0)) | |
8b57bfeb JJ |
4550 | zsi = zero_length_string (lhs, si); |
4551 | } | |
4552 | if (zsi != NULL | |
4553 | && si->endptr != NULL_TREE | |
4554 | && si->endptr != lhs | |
4555 | && TREE_CODE (si->endptr) == SSA_NAME) | |
4556 | { | |
4557 | enum tree_code rhs_code | |
4558 | = useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (si->endptr)) | |
4559 | ? SSA_NAME : NOP_EXPR; | |
00d66391 | 4560 | gimple_assign_set_rhs_with_ops (gsi, rhs_code, si->endptr); |
8b57bfeb JJ |
4561 | gcc_assert (gsi_stmt (*gsi) == stmt); |
4562 | update_stmt (stmt); | |
4563 | } | |
4564 | } | |
4565 | ||
b631bdb3 | 4566 | /* Describes recursion limits used by count_nonzero_bytes. */ |
a011292a | 4567 | |
b631bdb3 MS |
4568 | class ssa_name_limit_t |
4569 | { | |
4570 | bitmap visited; /* Bitmap of visited SSA_NAMEs. */ | |
4571 | unsigned ssa_def_max; /* Longest chain of SSA_NAMEs to follow. */ | |
4572 | ||
4573 | /* Not copyable or assignable. */ | |
4574 | ssa_name_limit_t (ssa_name_limit_t&); | |
4575 | void operator= (ssa_name_limit_t&); | |
4576 | ||
4577 | public: | |
4578 | ||
4579 | ssa_name_limit_t () | |
4580 | : visited (NULL), | |
028d4092 | 4581 | ssa_def_max (param_ssa_name_def_chain_limit) { } |
b631bdb3 MS |
4582 | |
4583 | int next_ssa_name (tree); | |
4584 | ||
4585 | ~ssa_name_limit_t () | |
4586 | { | |
4587 | if (visited) | |
4588 | BITMAP_FREE (visited); | |
4589 | } | |
4590 | }; | |
4591 | ||
4592 | /* If the SSA_NAME has already been "seen" return a positive value. | |
4593 | Otherwise add it to VISITED. If the SSA_NAME limit has been | |
4594 | reached, return a negative value. Otherwise return zero. */ | |
4595 | ||
4596 | int ssa_name_limit_t::next_ssa_name (tree ssa_name) | |
4597 | { | |
4598 | if (!visited) | |
4599 | visited = BITMAP_ALLOC (NULL); | |
4600 | ||
4601 | /* Return a positive value if SSA_NAME has already been visited. */ | |
4602 | if (!bitmap_set_bit (visited, SSA_NAME_VERSION (ssa_name))) | |
4603 | return 1; | |
4604 | ||
4605 | /* Return a negative value to let caller avoid recursing beyond | |
4606 | the specified limit. */ | |
4607 | if (ssa_def_max == 0) | |
4608 | return -1; | |
4609 | ||
4610 | --ssa_def_max; | |
4611 | ||
4612 | return 0; | |
4613 | } | |
4614 | ||
a9a437ff JJ |
4615 | static bool |
4616 | count_nonzero_bytes_addr (tree, unsigned HOST_WIDE_INT, unsigned HOST_WIDE_INT, | |
4617 | unsigned [3], bool *, bool *, bool *, | |
4618 | const vr_values *, ssa_name_limit_t &); | |
4619 | ||
7c3ed632 | 4620 | /* Determines the minimum and maximum number of leading non-zero bytes |
b631bdb3 | 4621 | in the representation of EXP and set LENRANGE[0] and LENRANGE[1] |
1e9369c5 MS |
4622 | to each. |
4623 | Sets LENRANGE[2] to the total size of the access (which may be less | |
4624 | than LENRANGE[1] when what's being referenced by EXP is a pointer | |
4625 | rather than an array). | |
4626 | Sets *NULTERM if the representation contains a zero byte, and sets | |
4627 | *ALLNUL if all the bytes are zero. | |
7c3ed632 | 4628 | OFFSET and NBYTES are the offset into the representation and |
1e9369c5 MS |
4629 | the size of the access to it determined from an ADDR_EXPR (i.e., |
4630 | a pointer) or MEM_REF or zero for other expressions. | |
ef29b12c MS |
4631 | Uses RVALS to determine range information. |
4632 | Avoids recursing deeper than the limits in SNLIM allow. | |
7c3ed632 | 4633 | Returns true on success and false otherwise. */ |
b631bdb3 MS |
4634 | |
4635 | static bool | |
34fcf41e MS |
4636 | count_nonzero_bytes (tree exp, unsigned HOST_WIDE_INT offset, |
4637 | unsigned HOST_WIDE_INT nbytes, | |
4638 | unsigned lenrange[3], bool *nulterm, | |
27c14dbc MS |
4639 | bool *allnul, bool *allnonnul, const vr_values *rvals, |
4640 | ssa_name_limit_t &snlim) | |
65f2d1ee | 4641 | { |
b631bdb3 | 4642 | if (TREE_CODE (exp) == SSA_NAME) |
aca8570e | 4643 | { |
27c14dbc | 4644 | /* Handle non-zero single-character stores specially. */ |
b631bdb3 MS |
4645 | tree type = TREE_TYPE (exp); |
4646 | if (TREE_CODE (type) == INTEGER_TYPE | |
4647 | && TYPE_MODE (type) == TYPE_MODE (char_type_node) | |
daa94de2 MS |
4648 | && TYPE_PRECISION (type) == TYPE_PRECISION (char_type_node) |
4649 | && tree_expr_nonzero_p (exp)) | |
4650 | { | |
4651 | /* If the character EXP is known to be non-zero (even if its | |
4652 | exact value is not known) recurse once to set the range | |
4653 | for an arbitrary constant. */ | |
4654 | exp = build_int_cst (type, 1); | |
4655 | return count_nonzero_bytes (exp, offset, 1, lenrange, | |
27c14dbc | 4656 | nulterm, allnul, allnonnul, rvals, snlim); |
aca8570e MS |
4657 | } |
4658 | ||
b631bdb3 | 4659 | gimple *stmt = SSA_NAME_DEF_STMT (exp); |
daa94de2 | 4660 | if (gimple_assign_single_p (stmt)) |
b631bdb3 | 4661 | { |
daa94de2 MS |
4662 | exp = gimple_assign_rhs1 (stmt); |
4663 | if (TREE_CODE (exp) != MEM_REF) | |
b631bdb3 | 4664 | return false; |
27c14dbc | 4665 | /* Handle MEM_REF below. */ |
b631bdb3 | 4666 | } |
daa94de2 MS |
4667 | else if (gimple_code (stmt) == GIMPLE_PHI) |
4668 | { | |
4669 | /* Avoid processing an SSA_NAME that has already been visited | |
4670 | or if an SSA_NAME limit has been reached. Indicate success | |
4671 | if the former and failure if the latter. */ | |
4672 | if (int res = snlim.next_ssa_name (exp)) | |
4673 | return res > 0; | |
4674 | ||
4675 | /* Determine the minimum and maximum from the PHI arguments. */ | |
4676 | unsigned int n = gimple_phi_num_args (stmt); | |
4677 | for (unsigned i = 0; i != n; i++) | |
4678 | { | |
4679 | tree def = gimple_phi_arg_def (stmt, i); | |
4680 | if (!count_nonzero_bytes (def, offset, nbytes, lenrange, nulterm, | |
27c14dbc | 4681 | allnul, allnonnul, rvals, snlim)) |
daa94de2 MS |
4682 | return false; |
4683 | } | |
b631bdb3 | 4684 | |
daa94de2 MS |
4685 | return true; |
4686 | } | |
aca8570e MS |
4687 | } |
4688 | ||
b631bdb3 | 4689 | if (TREE_CODE (exp) == MEM_REF) |
65f2d1ee | 4690 | { |
7c3ed632 MS |
4691 | if (nbytes) |
4692 | return false; | |
4693 | ||
b631bdb3 | 4694 | tree arg = TREE_OPERAND (exp, 0); |
b631bdb3 | 4695 | tree off = TREE_OPERAND (exp, 1); |
34fcf41e | 4696 | |
a9a437ff | 4697 | if (TREE_CODE (off) != INTEGER_CST || !tree_fits_uhwi_p (off)) |
b631bdb3 MS |
4698 | return false; |
4699 | ||
34fcf41e MS |
4700 | unsigned HOST_WIDE_INT wioff = tree_to_uhwi (off); |
4701 | if (INT_MAX < wioff) | |
4702 | return false; | |
4703 | ||
4704 | offset += wioff; | |
b631bdb3 MS |
4705 | if (INT_MAX < offset) |
4706 | return false; | |
4707 | ||
4708 | /* The size of the MEM_REF access determines the number of bytes. */ | |
4709 | tree type = TREE_TYPE (exp); | |
0186d373 RS |
4710 | tree typesize = TYPE_SIZE_UNIT (type); |
4711 | if (!typesize || !tree_fits_uhwi_p (typesize)) | |
34fcf41e | 4712 | return false; |
0186d373 | 4713 | nbytes = tree_to_uhwi (typesize); |
a9a437ff JJ |
4714 | if (!nbytes) |
4715 | return false; | |
b631bdb3 | 4716 | |
34fcf41e | 4717 | /* Handle MEM_REF = SSA_NAME types of assignments. */ |
a9a437ff JJ |
4718 | return count_nonzero_bytes_addr (arg, offset, nbytes, lenrange, nulterm, |
4719 | allnul, allnonnul, rvals, snlim); | |
b631bdb3 MS |
4720 | } |
4721 | ||
a9a437ff | 4722 | if (VAR_P (exp) || TREE_CODE (exp) == CONST_DECL) |
b631bdb3 | 4723 | { |
a9a437ff | 4724 | exp = ctor_for_folding (exp); |
b631bdb3 MS |
4725 | if (!exp) |
4726 | return false; | |
4727 | } | |
4728 | ||
34fcf41e | 4729 | const char *prep = NULL; |
b631bdb3 MS |
4730 | if (TREE_CODE (exp) == STRING_CST) |
4731 | { | |
34fcf41e MS |
4732 | unsigned nchars = TREE_STRING_LENGTH (exp); |
4733 | if (nchars < offset) | |
4734 | return false; | |
b631bdb3 MS |
4735 | |
4736 | if (!nbytes) | |
1e9369c5 MS |
4737 | /* If NBYTES hasn't been determined earlier, either from ADDR_EXPR |
4738 | (i.e., it's the size of a pointer), or from MEM_REF (as the size | |
4739 | of the access), set it here to the size of the string, including | |
4740 | all internal and trailing nuls if the string has any. */ | |
34fcf41e | 4741 | nbytes = nchars - offset; |
741ff2a2 JJ |
4742 | else if (nchars - offset < nbytes) |
4743 | return false; | |
b631bdb3 MS |
4744 | |
4745 | prep = TREE_STRING_POINTER (exp) + offset; | |
4746 | } | |
4747 | ||
4748 | unsigned char buf[256]; | |
4749 | if (!prep) | |
4750 | { | |
a9a437ff JJ |
4751 | if (CHAR_BIT != 8 || BITS_PER_UNIT != 8) |
4752 | return false; | |
34fcf41e MS |
4753 | /* If the pointer to representation hasn't been set above |
4754 | for STRING_CST point it at the buffer. */ | |
4755 | prep = reinterpret_cast <char *>(buf); | |
4756 | /* Try to extract the representation of the constant object | |
4757 | or expression starting from the offset. */ | |
daa94de2 MS |
4758 | unsigned repsize = native_encode_expr (exp, buf, sizeof buf, offset); |
4759 | if (repsize < nbytes) | |
4760 | { | |
4761 | /* This should only happen when REPSIZE is zero because EXP | |
4762 | doesn't denote an object with a known initializer, except | |
4763 | perhaps when the reference reads past its end. */ | |
4764 | lenrange[0] = 0; | |
4765 | prep = NULL; | |
4766 | } | |
7c3ed632 | 4767 | else if (!nbytes) |
daa94de2 | 4768 | nbytes = repsize; |
7c3ed632 MS |
4769 | else if (nbytes < repsize) |
4770 | return false; | |
05ef3173 MS |
4771 | } |
4772 | ||
daa94de2 MS |
4773 | if (!nbytes) |
4774 | return false; | |
4775 | ||
b631bdb3 MS |
4776 | /* Compute the number of leading nonzero bytes in the representation |
4777 | and update the minimum and maximum. */ | |
daa94de2 | 4778 | unsigned n = prep ? strnlen (prep, nbytes) : nbytes; |
b631bdb3 MS |
4779 | |
4780 | if (n < lenrange[0]) | |
4781 | lenrange[0] = n; | |
4782 | if (lenrange[1] < n) | |
4783 | lenrange[1] = n; | |
4784 | ||
4785 | /* Set the size of the representation. */ | |
4786 | if (lenrange[2] < nbytes) | |
4787 | lenrange[2] = nbytes; | |
05ef3173 | 4788 | |
b631bdb3 MS |
4789 | /* Clear NULTERM if none of the bytes is zero. */ |
4790 | if (n == nbytes) | |
4791 | *nulterm = false; | |
4792 | ||
4793 | if (n) | |
4794 | { | |
4795 | /* When the initial number of non-zero bytes N is non-zero, reset | |
a9a437ff JJ |
4796 | *ALLNUL; if N is less than that the size of the representation |
4797 | also clear *ALLNONNUL. */ | |
b631bdb3 MS |
4798 | *allnul = false; |
4799 | if (n < nbytes) | |
4800 | *allnonnul = false; | |
4801 | } | |
4802 | else if (*allnul || *allnonnul) | |
aca8570e | 4803 | { |
b631bdb3 MS |
4804 | *allnonnul = false; |
4805 | ||
4806 | if (*allnul) | |
4807 | { | |
4808 | /* When either ALLNUL is set and N is zero, also determine | |
4809 | whether all subsequent bytes after the first one (which | |
4810 | is nul) are zero or nonzero and clear ALLNUL if not. */ | |
4811 | for (const char *p = prep; p != prep + nbytes; ++p) | |
4812 | if (*p) | |
4813 | { | |
4814 | *allnul = false; | |
4815 | break; | |
4816 | } | |
4817 | } | |
aca8570e | 4818 | } |
65f2d1ee | 4819 | |
b631bdb3 MS |
4820 | return true; |
4821 | } | |
4822 | ||
a9a437ff JJ |
4823 | /* Like count_nonzero_bytes, but instead of counting bytes in EXP, count |
4824 | bytes that are pointed to by EXP, which should be a pointer. */ | |
4825 | ||
4826 | static bool | |
4827 | count_nonzero_bytes_addr (tree exp, unsigned HOST_WIDE_INT offset, | |
4828 | unsigned HOST_WIDE_INT nbytes, | |
4829 | unsigned lenrange[3], bool *nulterm, | |
4830 | bool *allnul, bool *allnonnul, | |
4831 | const vr_values *rvals, ssa_name_limit_t &snlim) | |
4832 | { | |
4833 | int idx = get_stridx (exp); | |
4834 | if (idx > 0) | |
4835 | { | |
4836 | strinfo *si = get_strinfo (idx); | |
4837 | if (!si) | |
4838 | return false; | |
4839 | ||
4840 | /* Handle both constant lengths as well non-constant lengths | |
4841 | in some range. */ | |
4842 | unsigned HOST_WIDE_INT minlen, maxlen; | |
4843 | if (tree_fits_shwi_p (si->nonzero_chars)) | |
4844 | minlen = maxlen = tree_to_shwi (si->nonzero_chars); | |
4845 | else if (si->nonzero_chars | |
4846 | && TREE_CODE (si->nonzero_chars) == SSA_NAME) | |
4847 | { | |
4848 | vr_values *v = CONST_CAST (vr_values *, rvals); | |
4849 | const value_range_equiv *vr = v->get_value_range (si->nonzero_chars); | |
4850 | if (vr->kind () != VR_RANGE || !range_int_cst_p (vr)) | |
4851 | return false; | |
4852 | ||
4853 | minlen = tree_to_uhwi (vr->min ()); | |
4854 | maxlen = tree_to_uhwi (vr->max ()); | |
4855 | } | |
4856 | else | |
4857 | return false; | |
4858 | ||
4859 | if (maxlen < offset) | |
4860 | return false; | |
4861 | ||
4862 | minlen = minlen < offset ? 0 : minlen - offset; | |
4863 | maxlen -= offset; | |
4864 | if (maxlen + 1 < nbytes) | |
4865 | return false; | |
4866 | ||
4867 | if (nbytes <= minlen) | |
4868 | *nulterm = false; | |
4869 | ||
4870 | if (nbytes < minlen) | |
4871 | { | |
4872 | minlen = nbytes; | |
4873 | if (nbytes < maxlen) | |
4874 | maxlen = nbytes; | |
4875 | } | |
4876 | ||
4877 | if (minlen < lenrange[0]) | |
4878 | lenrange[0] = minlen; | |
4879 | if (lenrange[1] < maxlen) | |
4880 | lenrange[1] = maxlen; | |
4881 | ||
4882 | if (lenrange[2] < nbytes) | |
4883 | lenrange[2] = nbytes; | |
4884 | ||
4885 | /* Since only the length of the string are known and not its contents, | |
4886 | clear ALLNUL and ALLNONNUL purely on the basis of the length. */ | |
4887 | *allnul = false; | |
4888 | if (minlen < nbytes) | |
4889 | *allnonnul = false; | |
4890 | ||
4891 | return true; | |
4892 | } | |
4893 | ||
4894 | if (TREE_CODE (exp) == ADDR_EXPR) | |
4895 | return count_nonzero_bytes (TREE_OPERAND (exp, 0), offset, nbytes, | |
4896 | lenrange, nulterm, allnul, allnonnul, rvals, | |
4897 | snlim); | |
4898 | ||
4899 | if (TREE_CODE (exp) == SSA_NAME) | |
4900 | { | |
4901 | gimple *stmt = SSA_NAME_DEF_STMT (exp); | |
4902 | if (gimple_code (stmt) == GIMPLE_PHI) | |
4903 | { | |
4904 | /* Avoid processing an SSA_NAME that has already been visited | |
4905 | or if an SSA_NAME limit has been reached. Indicate success | |
4906 | if the former and failure if the latter. */ | |
4907 | if (int res = snlim.next_ssa_name (exp)) | |
4908 | return res > 0; | |
4909 | ||
4910 | /* Determine the minimum and maximum from the PHI arguments. */ | |
4911 | unsigned int n = gimple_phi_num_args (stmt); | |
4912 | for (unsigned i = 0; i != n; i++) | |
4913 | { | |
4914 | tree def = gimple_phi_arg_def (stmt, i); | |
4915 | if (!count_nonzero_bytes_addr (def, offset, nbytes, lenrange, | |
4916 | nulterm, allnul, allnonnul, rvals, | |
4917 | snlim)) | |
4918 | return false; | |
4919 | } | |
4920 | ||
4921 | return true; | |
4922 | } | |
4923 | } | |
4924 | ||
4925 | /* Otherwise we don't know anything. */ | |
4926 | lenrange[0] = 0; | |
4927 | if (lenrange[1] < nbytes) | |
4928 | lenrange[1] = nbytes; | |
4929 | if (lenrange[2] < nbytes) | |
4930 | lenrange[2] = nbytes; | |
4931 | *nulterm = false; | |
4932 | *allnul = false; | |
4933 | *allnonnul = false; | |
4934 | return true; | |
4935 | } | |
4936 | ||
27c14dbc MS |
4937 | /* Same as above except with an implicit SSA_NAME limit. RVALS is used |
4938 | to determine ranges of dynamically computed string lengths (the results | |
4939 | of strlen). */ | |
b631bdb3 MS |
4940 | |
4941 | static bool | |
4942 | count_nonzero_bytes (tree exp, unsigned lenrange[3], bool *nulterm, | |
27c14dbc | 4943 | bool *allnul, bool *allnonnul, const vr_values *rvals) |
b631bdb3 MS |
4944 | { |
4945 | /* Set to optimistic values so the caller doesn't have to worry about | |
4946 | initializing these and to what. On success, the function will clear | |
4947 | these if it determines their values are different but being recursive | |
4948 | it never sets either to true. On failure, their values are | |
4949 | unspecified. */ | |
4950 | *nulterm = true; | |
4951 | *allnul = true; | |
4952 | *allnonnul = true; | |
4953 | ||
4954 | ssa_name_limit_t snlim; | |
34fcf41e | 4955 | return count_nonzero_bytes (exp, 0, 0, lenrange, nulterm, allnul, allnonnul, |
27c14dbc | 4956 | rvals, snlim); |
65f2d1ee PK |
4957 | } |
4958 | ||
b631bdb3 MS |
4959 | /* Handle a single or multibyte store other than by a built-in function, |
4960 | either via a single character assignment or by multi-byte assignment | |
4961 | either via MEM_REF or via a type other than char (such as in | |
79d2e614 JJ |
4962 | '*(int*)a = 12345'). Return true to let the caller advance *GSI to |
4963 | the next statement in the basic block and false otherwise. */ | |
8b57bfeb JJ |
4964 | |
4965 | static bool | |
ef29b12c MS |
4966 | handle_store (gimple_stmt_iterator *gsi, bool *zero_write, |
4967 | const vr_values *rvals) | |
8b57bfeb JJ |
4968 | { |
4969 | int idx = -1; | |
526ceb68 | 4970 | strinfo *si = NULL; |
355fe088 | 4971 | gimple *stmt = gsi_stmt (*gsi); |
8b57bfeb | 4972 | tree ssaname = NULL_TREE, lhs = gimple_assign_lhs (stmt); |
e3f9a279 | 4973 | tree rhs = gimple_assign_rhs1 (stmt); |
b631bdb3 | 4974 | |
700d4cb0 | 4975 | /* The offset of the first byte in LHS modified by the store. */ |
e3f9a279 | 4976 | unsigned HOST_WIDE_INT offset = 0; |
8b57bfeb JJ |
4977 | |
4978 | if (TREE_CODE (lhs) == MEM_REF | |
4979 | && TREE_CODE (TREE_OPERAND (lhs, 0)) == SSA_NAME) | |
4980 | { | |
e3f9a279 RS |
4981 | tree mem_offset = TREE_OPERAND (lhs, 1); |
4982 | if (tree_fits_uhwi_p (mem_offset)) | |
8b57bfeb | 4983 | { |
e3f9a279 RS |
4984 | /* Get the strinfo for the base, and use it if it starts with at |
4985 | least OFFSET nonzero characters. This is trivially true if | |
4986 | OFFSET is zero. */ | |
4987 | offset = tree_to_uhwi (mem_offset); | |
4988 | idx = get_stridx (TREE_OPERAND (lhs, 0)); | |
4989 | if (idx > 0) | |
4990 | si = get_strinfo (idx); | |
4991 | if (offset == 0) | |
4992 | ssaname = TREE_OPERAND (lhs, 0); | |
27c14dbc | 4993 | else if (si == NULL || compare_nonzero_chars (si, offset, rvals) < 0) |
2fcb55d1 MS |
4994 | { |
4995 | *zero_write = initializer_zerop (rhs); | |
f7d86b5c MS |
4996 | |
4997 | bool dummy; | |
4998 | unsigned lenrange[] = { UINT_MAX, 0, 0 }; | |
4999 | if (count_nonzero_bytes (rhs, lenrange, &dummy, &dummy, &dummy, | |
5000 | rvals)) | |
5001 | maybe_warn_overflow (stmt, lenrange[2], rvals); | |
5002 | ||
2fcb55d1 MS |
5003 | return true; |
5004 | } | |
8b57bfeb JJ |
5005 | } |
5006 | } | |
5007 | else | |
e3f9a279 | 5008 | { |
efe646c4 | 5009 | idx = get_addr_stridx (lhs, NULL_TREE, &offset, rvals); |
e3f9a279 RS |
5010 | if (idx > 0) |
5011 | si = get_strinfo (idx); | |
5012 | } | |
8b57bfeb | 5013 | |
b631bdb3 MS |
5014 | /* Minimum and maximum leading non-zero bytes and the size of the store. */ |
5015 | unsigned lenrange[] = { UINT_MAX, 0, 0 }; | |
5016 | ||
5017 | /* Set to the minimum length of the string being assigned if known. */ | |
5018 | unsigned HOST_WIDE_INT rhs_minlen; | |
5019 | ||
aca8570e | 5020 | /* STORING_NONZERO_P is true iff not all stored characters are zero. |
b631bdb3 | 5021 | STORING_ALL_NONZERO_P is true if all stored characters are zero. |
aca8570e MS |
5022 | STORING_ALL_ZEROS_P is true iff all stored characters are zero. |
5023 | Both are false when it's impossible to determine which is true. */ | |
5024 | bool storing_nonzero_p; | |
b631bdb3 MS |
5025 | bool storing_all_nonzero_p; |
5026 | bool storing_all_zeros_p; | |
5027 | /* FULL_STRING_P is set when the stored sequence of characters form | |
5028 | a nul-terminated string. */ | |
5029 | bool full_string_p; | |
aca8570e | 5030 | |
b631bdb3 MS |
5031 | const bool ranges_valid |
5032 | = count_nonzero_bytes (rhs, lenrange, &full_string_p, | |
27c14dbc MS |
5033 | &storing_all_zeros_p, &storing_all_nonzero_p, |
5034 | rvals); | |
b631bdb3 MS |
5035 | if (ranges_valid) |
5036 | { | |
5037 | rhs_minlen = lenrange[0]; | |
5038 | storing_nonzero_p = lenrange[1] > 0; | |
2fcb55d1 | 5039 | *zero_write = storing_all_zeros_p; |
b631bdb3 | 5040 | |
f7d86b5c | 5041 | maybe_warn_overflow (stmt, lenrange[2], rvals); |
b631bdb3 MS |
5042 | } |
5043 | else | |
5044 | { | |
5045 | rhs_minlen = HOST_WIDE_INT_M1U; | |
5046 | full_string_p = false; | |
5047 | storing_nonzero_p = false; | |
5048 | storing_all_zeros_p = false; | |
5049 | storing_all_nonzero_p = false; | |
5050 | } | |
e3f9a279 RS |
5051 | |
5052 | if (si != NULL) | |
8b57bfeb | 5053 | { |
b631bdb3 MS |
5054 | /* The corresponding element is set to 1 if the first and last |
5055 | element, respectively, of the sequence of characters being | |
5056 | written over the string described by SI ends before | |
5057 | the terminating nul (if it has one), to zero if the nul is | |
5058 | being overwritten but not beyond, or negative otherwise. */ | |
5059 | int store_before_nul[2]; | |
5060 | if (ranges_valid) | |
5061 | { | |
5062 | /* The offset of the last stored byte. */ | |
5063 | unsigned HOST_WIDE_INT endoff = offset + lenrange[2] - 1; | |
27c14dbc | 5064 | store_before_nul[0] = compare_nonzero_chars (si, offset, rvals); |
b631bdb3 MS |
5065 | if (endoff == offset) |
5066 | store_before_nul[1] = store_before_nul[0]; | |
5067 | else | |
27c14dbc | 5068 | store_before_nul[1] = compare_nonzero_chars (si, endoff, rvals); |
b631bdb3 MS |
5069 | } |
5070 | else | |
5071 | { | |
27c14dbc | 5072 | store_before_nul[0] = compare_nonzero_chars (si, offset, rvals); |
b631bdb3 MS |
5073 | store_before_nul[1] = store_before_nul[0]; |
5074 | gcc_assert (offset == 0 || store_before_nul[0] >= 0); | |
5075 | } | |
5076 | ||
5077 | if (storing_all_zeros_p | |
5078 | && store_before_nul[0] == 0 | |
5079 | && store_before_nul[1] == 0 | |
5080 | && si->full_string_p) | |
8b57bfeb | 5081 | { |
e3f9a279 RS |
5082 | /* When overwriting a '\0' with a '\0', the store can be removed |
5083 | if we know it has been stored in the current function. */ | |
36bbc05d | 5084 | if (!stmt_could_throw_p (cfun, stmt) && si->writable) |
8b57bfeb | 5085 | { |
e3f9a279 RS |
5086 | unlink_stmt_vdef (stmt); |
5087 | release_defs (stmt); | |
5088 | gsi_remove (gsi, true); | |
5089 | return false; | |
8b57bfeb JJ |
5090 | } |
5091 | else | |
e3f9a279 RS |
5092 | { |
5093 | si->writable = true; | |
5094 | gsi_next (gsi); | |
5095 | return false; | |
5096 | } | |
8b57bfeb | 5097 | } |
c2e8bd51 | 5098 | |
b631bdb3 | 5099 | if (store_before_nul[1] > 0 |
c2e8bd51 | 5100 | && storing_nonzero_p |
b631bdb3 MS |
5101 | && lenrange[0] == lenrange[1] |
5102 | && lenrange[0] == lenrange[2] | |
c2e8bd51 | 5103 | && TREE_CODE (TREE_TYPE (rhs)) == INTEGER_TYPE) |
5b115c1f | 5104 | { |
b631bdb3 MS |
5105 | /* Handle a store of one or more non-nul characters that ends |
5106 | before the terminating nul of the destination and so does | |
5107 | not affect its length | |
c2e8bd51 | 5108 | If si->nonzero_chars > OFFSET, we aren't overwriting '\0', |
b631bdb3 MS |
5109 | and if we aren't storing '\0', we know that the length of |
5110 | the string and any other zero terminated string in memory | |
5111 | remains the same. In that case we move to the next gimple | |
5112 | statement and return to signal the caller that it shouldn't | |
5113 | invalidate anything. | |
c2e8bd51 | 5114 | |
dfea3d6f | 5115 | This is beneficial for cases like: |
c2e8bd51 MS |
5116 | |
5117 | char p[20]; | |
5118 | void foo (char *q) | |
5119 | { | |
5120 | strcpy (p, "foobar"); | |
5121 | size_t len = strlen (p); // can be folded to 6 | |
5122 | size_t len2 = strlen (q); // has to be computed | |
5123 | p[0] = 'X'; | |
5124 | size_t len3 = strlen (p); // can be folded to 6 | |
5125 | size_t len4 = strlen (q); // can be folded to len2 | |
5126 | bar (len, len2, len3, len4); | |
5127 | } */ | |
5b115c1f MP |
5128 | gsi_next (gsi); |
5129 | return false; | |
5130 | } | |
c2e8bd51 MS |
5131 | |
5132 | if (storing_all_zeros_p | |
5133 | || storing_nonzero_p | |
b631bdb3 | 5134 | || (offset != 0 && store_before_nul[1] > 0)) |
e3f9a279 | 5135 | { |
aca8570e MS |
5136 | /* When STORING_NONZERO_P, we know that the string will start |
5137 | with at least OFFSET + 1 nonzero characters. If storing | |
5138 | a single character, set si->NONZERO_CHARS to the result. | |
5139 | If storing multiple characters, try to determine the number | |
5140 | of leading non-zero characters and set si->NONZERO_CHARS to | |
5141 | the result instead. | |
e3f9a279 | 5142 | |
aca8570e MS |
5143 | When STORING_ALL_ZEROS_P, we know that the string is now |
5144 | OFFSET characters long. | |
e3f9a279 RS |
5145 | |
5146 | Otherwise, we're storing an unknown value at offset OFFSET, | |
b631bdb3 MS |
5147 | so need to clip the nonzero_chars to OFFSET. |
5148 | Use the minimum length of the string (or individual character) | |
5149 | being stored if it's known. Otherwise, STORING_NONZERO_P | |
5150 | guarantees it's at least 1. */ | |
5151 | HOST_WIDE_INT len | |
5152 | = storing_nonzero_p && ranges_valid ? lenrange[0] : 1; | |
e3f9a279 RS |
5153 | location_t loc = gimple_location (stmt); |
5154 | tree oldlen = si->nonzero_chars; | |
b631bdb3 | 5155 | if (store_before_nul[1] == 0 && si->full_string_p) |
e3f9a279 RS |
5156 | /* We're overwriting the nul terminator with a nonzero or |
5157 | unknown character. If the previous stmt was a memcpy, | |
5158 | its length may be decreased. */ | |
5159 | adjust_last_stmt (si, stmt, false); | |
5160 | si = unshare_strinfo (si); | |
5161 | if (storing_nonzero_p) | |
aca8570e MS |
5162 | { |
5163 | gcc_assert (len >= 0); | |
5164 | si->nonzero_chars = build_int_cst (size_type_node, offset + len); | |
5165 | } | |
e3f9a279 RS |
5166 | else |
5167 | si->nonzero_chars = build_int_cst (size_type_node, offset); | |
34fcf41e MS |
5168 | |
5169 | /* Set FULL_STRING_P only if the length of the strings being | |
5170 | written is the same, and clear it if the strings have | |
5171 | different lengths. In the latter case the length stored | |
5172 | in si->NONZERO_CHARS becomes the lower bound. | |
5173 | FIXME: Handle the upper bound of the length if possible. */ | |
5174 | si->full_string_p = full_string_p && lenrange[0] == lenrange[1]; | |
5175 | ||
aca8570e | 5176 | if (storing_all_zeros_p |
e3f9a279 RS |
5177 | && ssaname |
5178 | && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ssaname)) | |
5179 | si->endptr = ssaname; | |
5180 | else | |
5181 | si->endptr = NULL; | |
5182 | si->next = 0; | |
5183 | si->stmt = NULL; | |
5184 | si->writable = true; | |
5185 | si->dont_invalidate = true; | |
5186 | if (oldlen) | |
5187 | { | |
5188 | tree adj = fold_build2_loc (loc, MINUS_EXPR, size_type_node, | |
5189 | si->nonzero_chars, oldlen); | |
5190 | adjust_related_strinfos (loc, si, adj); | |
5191 | } | |
5192 | else | |
5193 | si->prev = 0; | |
5194 | } | |
8b57bfeb | 5195 | } |
aca8570e | 5196 | else if (idx == 0 && (storing_all_zeros_p || storing_nonzero_p)) |
8b57bfeb JJ |
5197 | { |
5198 | if (ssaname) | |
e3f9a279 | 5199 | idx = new_stridx (ssaname); |
8b57bfeb | 5200 | else |
e3f9a279 RS |
5201 | idx = new_addr_stridx (lhs); |
5202 | if (idx != 0) | |
8b57bfeb | 5203 | { |
e3f9a279 | 5204 | tree ptr = (ssaname ? ssaname : build_fold_addr_expr (lhs)); |
34fcf41e MS |
5205 | |
5206 | HOST_WIDE_INT slen; | |
5207 | if (storing_all_zeros_p) | |
5208 | slen = 0; | |
5209 | else if (storing_nonzero_p && ranges_valid) | |
5210 | { | |
5211 | /* FIXME: Handle the upper bound of the length when | |
5212 | LENRANGE[0] != LENRANGE[1]. */ | |
5213 | slen = lenrange[0]; | |
5214 | if (lenrange[0] != lenrange[1]) | |
5215 | /* Set the minimum length but ignore the maximum | |
5216 | for now. */ | |
5217 | full_string_p = false; | |
5218 | } | |
5219 | else | |
5220 | slen = -1; | |
5221 | ||
aca8570e MS |
5222 | tree len = (slen <= 0 |
5223 | ? size_zero_node | |
5224 | : build_int_cst (size_type_node, slen)); | |
5225 | si = new_strinfo (ptr, idx, len, slen >= 0 && full_string_p); | |
e3f9a279 | 5226 | set_strinfo (idx, si); |
aca8570e | 5227 | if (storing_all_zeros_p |
e3f9a279 RS |
5228 | && ssaname |
5229 | && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ssaname)) | |
5230 | si->endptr = ssaname; | |
5231 | si->dont_invalidate = true; | |
5232 | si->writable = true; | |
8b57bfeb | 5233 | } |
8b57bfeb | 5234 | } |
198fe1bf | 5235 | else if (idx == 0 |
b631bdb3 | 5236 | && rhs_minlen < HOST_WIDE_INT_M1U |
198fe1bf JJ |
5237 | && ssaname == NULL_TREE |
5238 | && TREE_CODE (TREE_TYPE (lhs)) == ARRAY_TYPE) | |
5239 | { | |
198fe1bf | 5240 | HOST_WIDE_INT a = int_size_in_bytes (TREE_TYPE (lhs)); |
b631bdb3 | 5241 | if (a > 0 && (unsigned HOST_WIDE_INT) a > rhs_minlen) |
198fe1bf JJ |
5242 | { |
5243 | int idx = new_addr_stridx (lhs); | |
5244 | if (idx != 0) | |
5245 | { | |
5246 | si = new_strinfo (build_fold_addr_expr (lhs), idx, | |
b631bdb3 | 5247 | build_int_cst (size_type_node, rhs_minlen), |
aca8570e | 5248 | full_string_p); |
198fe1bf JJ |
5249 | set_strinfo (idx, si); |
5250 | si->dont_invalidate = true; | |
5251 | } | |
5252 | } | |
5253 | } | |
8b57bfeb | 5254 | |
e13f37d9 | 5255 | if (si != NULL && offset == 0 && storing_all_zeros_p && lenrange[2] == 1) |
8b57bfeb | 5256 | { |
e13f37d9 MS |
5257 | /* For single-byte stores only, allow adjust_last_stmt to remove |
5258 | the statement if the stored '\0' is immediately overwritten. */ | |
8b57bfeb JJ |
5259 | laststmt.stmt = stmt; |
5260 | laststmt.len = build_int_cst (size_type_node, 1); | |
5261 | laststmt.stridx = si->idx; | |
5262 | } | |
5263 | return true; | |
5264 | } | |
5265 | ||
f368600f | 5266 | /* Try to fold strstr (s, t) eq/ne s to strncmp (s, t, strlen (t)) eq/ne 0. */ |
3b1970cb PK |
5267 | |
5268 | static void | |
f368600f | 5269 | fold_strstr_to_strncmp (tree rhs1, tree rhs2, gimple *stmt) |
3b1970cb PK |
5270 | { |
5271 | if (TREE_CODE (rhs1) != SSA_NAME | |
5272 | || TREE_CODE (rhs2) != SSA_NAME) | |
5273 | return; | |
5274 | ||
5275 | gimple *call_stmt = NULL; | |
5276 | for (int pass = 0; pass < 2; pass++) | |
5277 | { | |
5278 | gimple *g = SSA_NAME_DEF_STMT (rhs1); | |
5279 | if (gimple_call_builtin_p (g, BUILT_IN_STRSTR) | |
5280 | && has_single_use (rhs1) | |
5281 | && gimple_call_arg (g, 0) == rhs2) | |
5282 | { | |
5283 | call_stmt = g; | |
5284 | break; | |
5285 | } | |
5286 | std::swap (rhs1, rhs2); | |
5287 | } | |
5288 | ||
5289 | if (call_stmt) | |
5290 | { | |
5291 | tree arg0 = gimple_call_arg (call_stmt, 0); | |
5292 | ||
5293 | if (arg0 == rhs2) | |
5294 | { | |
5295 | tree arg1 = gimple_call_arg (call_stmt, 1); | |
5296 | tree arg1_len = NULL_TREE; | |
5297 | int idx = get_stridx (arg1); | |
5298 | ||
5299 | if (idx) | |
5300 | { | |
5301 | if (idx < 0) | |
5302 | arg1_len = build_int_cst (size_type_node, ~idx); | |
5303 | else | |
5304 | { | |
5305 | strinfo *si = get_strinfo (idx); | |
5306 | if (si) | |
5307 | arg1_len = get_string_length (si); | |
5308 | } | |
5309 | } | |
5310 | ||
5311 | if (arg1_len != NULL_TREE) | |
5312 | { | |
5313 | gimple_stmt_iterator gsi = gsi_for_stmt (call_stmt); | |
f368600f | 5314 | tree strncmp_decl = builtin_decl_explicit (BUILT_IN_STRNCMP); |
96863f32 ML |
5315 | |
5316 | if (!is_gimple_val (arg1_len)) | |
5317 | { | |
5318 | tree arg1_len_tmp = make_ssa_name (TREE_TYPE (arg1_len)); | |
5319 | gassign *arg1_stmt = gimple_build_assign (arg1_len_tmp, | |
5320 | arg1_len); | |
5321 | gsi_insert_before (&gsi, arg1_stmt, GSI_SAME_STMT); | |
5322 | arg1_len = arg1_len_tmp; | |
5323 | } | |
5324 | ||
f368600f | 5325 | gcall *strncmp_call = gimple_build_call (strncmp_decl, 3, |
3b1970cb | 5326 | arg0, arg1, arg1_len); |
f368600f ML |
5327 | tree strncmp_lhs = make_ssa_name (integer_type_node); |
5328 | gimple_set_vuse (strncmp_call, gimple_vuse (call_stmt)); | |
5329 | gimple_call_set_lhs (strncmp_call, strncmp_lhs); | |
3b1970cb | 5330 | gsi_remove (&gsi, true); |
f368600f ML |
5331 | gsi_insert_before (&gsi, strncmp_call, GSI_SAME_STMT); |
5332 | tree zero = build_zero_cst (TREE_TYPE (strncmp_lhs)); | |
3b1970cb PK |
5333 | |
5334 | if (is_gimple_assign (stmt)) | |
5335 | { | |
5336 | if (gimple_assign_rhs_code (stmt) == COND_EXPR) | |
5337 | { | |
5338 | tree cond = gimple_assign_rhs1 (stmt); | |
f368600f | 5339 | TREE_OPERAND (cond, 0) = strncmp_lhs; |
3b1970cb PK |
5340 | TREE_OPERAND (cond, 1) = zero; |
5341 | } | |
5342 | else | |
5343 | { | |
f368600f | 5344 | gimple_assign_set_rhs1 (stmt, strncmp_lhs); |
3b1970cb PK |
5345 | gimple_assign_set_rhs2 (stmt, zero); |
5346 | } | |
5347 | } | |
5348 | else | |
5349 | { | |
5350 | gcond *cond = as_a<gcond *> (stmt); | |
f368600f | 5351 | gimple_cond_set_lhs (cond, strncmp_lhs); |
3b1970cb PK |
5352 | gimple_cond_set_rhs (cond, zero); |
5353 | } | |
5354 | update_stmt (stmt); | |
5355 | } | |
5356 | } | |
5357 | } | |
5358 | } | |
5359 | ||
b631bdb3 MS |
5360 | /* Return true if TYPE corresponds to a narrow character type. */ |
5361 | ||
5362 | static bool | |
5363 | is_char_type (tree type) | |
5364 | { | |
5365 | return (TREE_CODE (type) == INTEGER_TYPE | |
5366 | && TYPE_MODE (type) == TYPE_MODE (char_type_node) | |
5367 | && TYPE_PRECISION (type) == TYPE_PRECISION (char_type_node)); | |
5368 | } | |
5369 | ||
22fca489 | 5370 | /* Check the built-in call at GSI for validity and optimize it. |
ef29b12c | 5371 | Uses RVALS to determine range information. |
79d2e614 JJ |
5372 | Return true to let the caller advance *GSI to the next statement |
5373 | in the basic block and false otherwise. */ | |
22fca489 MS |
5374 | |
5375 | static bool | |
ef29b12c | 5376 | strlen_check_and_optimize_call (gimple_stmt_iterator *gsi, bool *zero_write, |
22fca489 MS |
5377 | const vr_values *rvals) |
5378 | { | |
5379 | gimple *stmt = gsi_stmt (*gsi); | |
5380 | ||
ef29b12c MS |
5381 | if (!gimple_call_builtin_p (stmt, BUILT_IN_NORMAL)) |
5382 | { | |
5383 | tree fntype = gimple_call_fntype (stmt); | |
5384 | if (fntype && lookup_attribute ("alloc_size", TYPE_ATTRIBUTES (fntype))) | |
5385 | handle_alloc_call (BUILT_IN_NONE, gsi); | |
5386 | } | |
5387 | ||
79d2e614 JJ |
5388 | /* When not optimizing we must be checking printf calls which |
5389 | we do even for user-defined functions when they are declared | |
5390 | with attribute format. */ | |
22fca489 MS |
5391 | if (!flag_optimize_strlen |
5392 | || !strlen_optimize | |
5393 | || !valid_builtin_call (stmt)) | |
79d2e614 | 5394 | return !handle_printf_call (gsi, rvals); |
22fca489 MS |
5395 | |
5396 | tree callee = gimple_call_fndecl (stmt); | |
5397 | switch (DECL_FUNCTION_CODE (callee)) | |
5398 | { | |
5399 | case BUILT_IN_STRLEN: | |
5400 | case BUILT_IN_STRNLEN: | |
5401 | handle_builtin_strlen (gsi); | |
5402 | break; | |
5403 | case BUILT_IN_STRCHR: | |
5404 | handle_builtin_strchr (gsi); | |
5405 | break; | |
5406 | case BUILT_IN_STRCPY: | |
5407 | case BUILT_IN_STRCPY_CHK: | |
5408 | case BUILT_IN_STPCPY: | |
5409 | case BUILT_IN_STPCPY_CHK: | |
ef29b12c | 5410 | handle_builtin_strcpy (DECL_FUNCTION_CODE (callee), gsi, rvals); |
22fca489 MS |
5411 | break; |
5412 | ||
5413 | case BUILT_IN_STRNCAT: | |
5414 | case BUILT_IN_STRNCAT_CHK: | |
5415 | handle_builtin_strncat (DECL_FUNCTION_CODE (callee), gsi); | |
5416 | break; | |
5417 | ||
5418 | case BUILT_IN_STPNCPY: | |
5419 | case BUILT_IN_STPNCPY_CHK: | |
5420 | case BUILT_IN_STRNCPY: | |
5421 | case BUILT_IN_STRNCPY_CHK: | |
0a0de963 | 5422 | handle_builtin_stxncpy_strncat (false, gsi); |
22fca489 MS |
5423 | break; |
5424 | ||
5425 | case BUILT_IN_MEMCPY: | |
5426 | case BUILT_IN_MEMCPY_CHK: | |
5427 | case BUILT_IN_MEMPCPY: | |
5428 | case BUILT_IN_MEMPCPY_CHK: | |
ef29b12c | 5429 | handle_builtin_memcpy (DECL_FUNCTION_CODE (callee), gsi, rvals); |
22fca489 MS |
5430 | break; |
5431 | case BUILT_IN_STRCAT: | |
5432 | case BUILT_IN_STRCAT_CHK: | |
5433 | handle_builtin_strcat (DECL_FUNCTION_CODE (callee), gsi); | |
5434 | break; | |
ef29b12c MS |
5435 | case BUILT_IN_ALLOCA: |
5436 | case BUILT_IN_ALLOCA_WITH_ALIGN: | |
22fca489 MS |
5437 | case BUILT_IN_MALLOC: |
5438 | case BUILT_IN_CALLOC: | |
ef29b12c | 5439 | handle_alloc_call (DECL_FUNCTION_CODE (callee), gsi); |
22fca489 MS |
5440 | break; |
5441 | case BUILT_IN_MEMSET: | |
ef29b12c | 5442 | if (handle_builtin_memset (gsi, zero_write, rvals)) |
22fca489 MS |
5443 | return false; |
5444 | break; | |
5445 | case BUILT_IN_MEMCMP: | |
5446 | if (handle_builtin_memcmp (gsi)) | |
5447 | return false; | |
5448 | break; | |
5449 | case BUILT_IN_STRCMP: | |
5450 | case BUILT_IN_STRNCMP: | |
e7868dc6 | 5451 | if (handle_builtin_string_cmp (gsi, rvals)) |
22fca489 MS |
5452 | return false; |
5453 | break; | |
5454 | default: | |
79d2e614 JJ |
5455 | if (handle_printf_call (gsi, rvals)) |
5456 | return false; | |
22fca489 MS |
5457 | break; |
5458 | } | |
5459 | ||
5460 | return true; | |
5461 | } | |
5462 | ||
5463 | /* Handle an assignment statement at *GSI to a LHS of integral type. | |
5464 | If GSI's basic block needs clean-up of EH, set *CLEANUP_EH to true. */ | |
5465 | ||
5466 | static void | |
ef29b12c MS |
5467 | handle_integral_assign (gimple_stmt_iterator *gsi, bool *cleanup_eh, |
5468 | const vr_values *rvals) | |
22fca489 MS |
5469 | { |
5470 | gimple *stmt = gsi_stmt (*gsi); | |
5471 | tree lhs = gimple_assign_lhs (stmt); | |
5472 | tree lhs_type = TREE_TYPE (lhs); | |
5473 | ||
5474 | enum tree_code code = gimple_assign_rhs_code (stmt); | |
5475 | if (code == COND_EXPR) | |
5476 | { | |
5477 | tree cond = gimple_assign_rhs1 (stmt); | |
5478 | enum tree_code cond_code = TREE_CODE (cond); | |
5479 | ||
5480 | if (cond_code == EQ_EXPR || cond_code == NE_EXPR) | |
5481 | fold_strstr_to_strncmp (TREE_OPERAND (cond, 0), | |
5482 | TREE_OPERAND (cond, 1), stmt); | |
5483 | } | |
5484 | else if (code == EQ_EXPR || code == NE_EXPR) | |
5485 | fold_strstr_to_strncmp (gimple_assign_rhs1 (stmt), | |
5486 | gimple_assign_rhs2 (stmt), stmt); | |
5487 | else if (gimple_assign_load_p (stmt) | |
5488 | && TREE_CODE (lhs_type) == INTEGER_TYPE | |
5489 | && TYPE_MODE (lhs_type) == TYPE_MODE (char_type_node) | |
5490 | && (TYPE_PRECISION (lhs_type) | |
5491 | == TYPE_PRECISION (char_type_node)) | |
5492 | && !gimple_has_volatile_ops (stmt)) | |
5493 | { | |
5494 | tree off = integer_zero_node; | |
5495 | unsigned HOST_WIDE_INT coff = 0; | |
5496 | int idx = 0; | |
5497 | tree rhs1 = gimple_assign_rhs1 (stmt); | |
5498 | if (code == MEM_REF) | |
5499 | { | |
5500 | idx = get_stridx (TREE_OPERAND (rhs1, 0)); | |
5501 | if (idx > 0) | |
5502 | { | |
5503 | strinfo *si = get_strinfo (idx); | |
5504 | if (si | |
5505 | && si->nonzero_chars | |
5506 | && TREE_CODE (si->nonzero_chars) == INTEGER_CST | |
5507 | && (wi::to_widest (si->nonzero_chars) | |
5508 | >= wi::to_widest (off))) | |
5509 | off = TREE_OPERAND (rhs1, 1); | |
5510 | else | |
5511 | /* This case is not useful. See if get_addr_stridx | |
5512 | returns something usable. */ | |
5513 | idx = 0; | |
5514 | } | |
5515 | } | |
5516 | if (idx <= 0) | |
5517 | idx = get_addr_stridx (rhs1, NULL_TREE, &coff); | |
5518 | if (idx > 0) | |
5519 | { | |
5520 | strinfo *si = get_strinfo (idx); | |
5521 | if (si | |
5522 | && si->nonzero_chars | |
5523 | && TREE_CODE (si->nonzero_chars) == INTEGER_CST) | |
5524 | { | |
5525 | widest_int w1 = wi::to_widest (si->nonzero_chars); | |
5526 | widest_int w2 = wi::to_widest (off) + coff; | |
5527 | if (w1 == w2 | |
5528 | && si->full_string_p) | |
5529 | { | |
5530 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
5531 | { | |
5532 | fprintf (dump_file, "Optimizing: "); | |
5533 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
5534 | } | |
5535 | ||
5536 | /* Reading the final '\0' character. */ | |
5537 | tree zero = build_int_cst (lhs_type, 0); | |
5538 | gimple_set_vuse (stmt, NULL_TREE); | |
5539 | gimple_assign_set_rhs_from_tree (gsi, zero); | |
5540 | *cleanup_eh | |
5541 | |= maybe_clean_or_replace_eh_stmt (stmt, | |
5542 | gsi_stmt (*gsi)); | |
5543 | stmt = gsi_stmt (*gsi); | |
5544 | update_stmt (stmt); | |
5545 | ||
5546 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
5547 | { | |
5548 | fprintf (dump_file, "into: "); | |
5549 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
5550 | } | |
5551 | } | |
5552 | else if (w1 > w2) | |
5553 | { | |
5554 | /* Reading a character before the final '\0' | |
5555 | character. Just set the value range to ~[0, 0] | |
5556 | if we don't have anything better. */ | |
5557 | wide_int min, max; | |
5558 | signop sign = TYPE_SIGN (lhs_type); | |
5559 | int prec = TYPE_PRECISION (lhs_type); | |
5560 | value_range_kind vr = get_range_info (lhs, &min, &max); | |
5561 | if (vr == VR_VARYING | |
5562 | || (vr == VR_RANGE | |
5563 | && min == wi::min_value (prec, sign) | |
5564 | && max == wi::max_value (prec, sign))) | |
5565 | set_range_info (lhs, VR_ANTI_RANGE, | |
5566 | wi::zero (prec), wi::zero (prec)); | |
5567 | } | |
5568 | } | |
5569 | } | |
5570 | } | |
ef29b12c MS |
5571 | else if (code == MEM_REF && TREE_CODE (lhs) == SSA_NAME) |
5572 | { | |
5573 | if (int idx = new_stridx (lhs)) | |
5574 | { | |
5575 | /* Record multi-byte assignments from MEM_REFs. */ | |
5576 | bool storing_all_nonzero_p; | |
5577 | bool storing_all_zeros_p; | |
5578 | bool full_string_p; | |
5579 | unsigned lenrange[] = { UINT_MAX, 0, 0 }; | |
5580 | tree rhs = gimple_assign_rhs1 (stmt); | |
5581 | const bool ranges_valid | |
5582 | = count_nonzero_bytes (rhs, lenrange, &full_string_p, | |
5583 | &storing_all_zeros_p, &storing_all_nonzero_p, | |
5584 | rvals); | |
5585 | if (ranges_valid) | |
5586 | { | |
5587 | tree length = build_int_cst (sizetype, lenrange[0]); | |
5588 | strinfo *si = new_strinfo (lhs, idx, length, full_string_p); | |
5589 | set_strinfo (idx, si); | |
5590 | si->writable = true; | |
5591 | si->dont_invalidate = true; | |
5592 | maybe_warn_overflow (stmt, lenrange[2], rvals); | |
5593 | } | |
5594 | } | |
5595 | } | |
22fca489 MS |
5596 | |
5597 | if (strlen_to_stridx) | |
5598 | { | |
5599 | tree rhs1 = gimple_assign_rhs1 (stmt); | |
5600 | if (stridx_strlenloc *ps = strlen_to_stridx->get (rhs1)) | |
5601 | strlen_to_stridx->put (lhs, stridx_strlenloc (*ps)); | |
5602 | } | |
5603 | } | |
5604 | ||
cc8bea0a | 5605 | /* Attempt to check for validity of the performed access a single statement |
fa9544ab ML |
5606 | at *GSI using string length knowledge, and to optimize it. |
5607 | If the given basic block needs clean-up of EH, CLEANUP_EH is set to | |
79d2e614 JJ |
5608 | true. Return true to let the caller advance *GSI to the next statement |
5609 | in the basic block and false otherwise. */ | |
8b57bfeb JJ |
5610 | |
5611 | static bool | |
22fca489 MS |
5612 | check_and_optimize_stmt (gimple_stmt_iterator *gsi, bool *cleanup_eh, |
5613 | const vr_values *rvals) | |
8b57bfeb | 5614 | { |
355fe088 | 5615 | gimple *stmt = gsi_stmt (*gsi); |
8b57bfeb | 5616 | |
2fcb55d1 MS |
5617 | /* For statements that modify a string, set to true if the write |
5618 | is only zeros. */ | |
5619 | bool zero_write = false; | |
5620 | ||
8b57bfeb JJ |
5621 | if (is_gimple_call (stmt)) |
5622 | { | |
2fcb55d1 | 5623 | if (!strlen_check_and_optimize_call (gsi, &zero_write, rvals)) |
22fca489 | 5624 | return false; |
8b57bfeb | 5625 | } |
22fca489 MS |
5626 | else if (!flag_optimize_strlen || !strlen_optimize) |
5627 | return true; | |
5004bd00 | 5628 | else if (is_gimple_assign (stmt) && !gimple_clobber_p (stmt)) |
8b57bfeb | 5629 | { |
22fca489 | 5630 | /* Handle non-clobbering assignment. */ |
8b57bfeb | 5631 | tree lhs = gimple_assign_lhs (stmt); |
22fca489 | 5632 | tree lhs_type = TREE_TYPE (lhs); |
8b57bfeb | 5633 | |
22fca489 | 5634 | if (TREE_CODE (lhs) == SSA_NAME && POINTER_TYPE_P (lhs_type)) |
8b57bfeb JJ |
5635 | { |
5636 | if (gimple_assign_single_p (stmt) | |
5637 | || (gimple_assign_cast_p (stmt) | |
5638 | && POINTER_TYPE_P (TREE_TYPE (gimple_assign_rhs1 (stmt))))) | |
5639 | { | |
5640 | int idx = get_stridx (gimple_assign_rhs1 (stmt)); | |
9771b263 | 5641 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] = idx; |
8b57bfeb JJ |
5642 | } |
5643 | else if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR) | |
5644 | handle_pointer_plus (gsi); | |
5645 | } | |
22fca489 MS |
5646 | else if (TREE_CODE (lhs) == SSA_NAME && INTEGRAL_TYPE_P (lhs_type)) |
5647 | /* Handle assignment to a character. */ | |
ef29b12c | 5648 | handle_integral_assign (gsi, cleanup_eh, rvals); |
22fca489 | 5649 | else if (TREE_CODE (lhs) != SSA_NAME && !TREE_SIDE_EFFECTS (lhs)) |
79d2e614 JJ |
5650 | { |
5651 | tree type = TREE_TYPE (lhs); | |
5652 | if (TREE_CODE (type) == ARRAY_TYPE) | |
5653 | type = TREE_TYPE (type); | |
b631bdb3 | 5654 | |
ef29b12c MS |
5655 | bool is_char_store = is_char_type (type); |
5656 | if (!is_char_store && TREE_CODE (lhs) == MEM_REF) | |
5657 | { | |
5658 | /* To consider stores into char objects via integer types | |
5659 | other than char but not those to non-character objects, | |
5660 | determine the type of the destination rather than just | |
5661 | the type of the access. */ | |
5662 | for (int i = 0; i != 2; ++i) | |
5663 | { | |
5664 | tree ref = TREE_OPERAND (lhs, i); | |
5665 | type = TREE_TYPE (ref); | |
5666 | if (TREE_CODE (type) == POINTER_TYPE) | |
5667 | type = TREE_TYPE (type); | |
5668 | if (TREE_CODE (type) == ARRAY_TYPE) | |
5669 | type = TREE_TYPE (type); | |
5670 | if (is_char_type (type)) | |
5671 | { | |
5672 | is_char_store = true; | |
5673 | break; | |
5674 | } | |
5675 | } | |
5676 | } | |
b631bdb3 | 5677 | |
79d2e614 JJ |
5678 | /* Handle a single or multibyte assignment. */ |
5679 | if (is_char_store && !handle_store (gsi, &zero_write, rvals)) | |
5680 | return false; | |
5681 | } | |
8b57bfeb | 5682 | } |
3b1970cb PK |
5683 | else if (gcond *cond = dyn_cast<gcond *> (stmt)) |
5684 | { | |
5685 | enum tree_code code = gimple_cond_code (cond); | |
5686 | if (code == EQ_EXPR || code == NE_EXPR) | |
f368600f ML |
5687 | fold_strstr_to_strncmp (gimple_cond_lhs (stmt), |
5688 | gimple_cond_rhs (stmt), stmt); | |
3b1970cb | 5689 | } |
8b57bfeb JJ |
5690 | |
5691 | if (gimple_vdef (stmt)) | |
2fcb55d1 | 5692 | maybe_invalidate (stmt, zero_write); |
8b57bfeb JJ |
5693 | return true; |
5694 | } | |
5695 | ||
5696 | /* Recursively call maybe_invalidate on stmts that might be executed | |
5697 | in between dombb and current bb and that contain a vdef. Stop when | |
5698 | *count stmts are inspected, or if the whole strinfo vector has | |
5699 | been invalidated. */ | |
5700 | ||
5701 | static void | |
355fe088 | 5702 | do_invalidate (basic_block dombb, gimple *phi, bitmap visited, int *count) |
8b57bfeb JJ |
5703 | { |
5704 | unsigned int i, n = gimple_phi_num_args (phi); | |
5705 | ||
5706 | for (i = 0; i < n; i++) | |
5707 | { | |
5708 | tree vuse = gimple_phi_arg_def (phi, i); | |
355fe088 | 5709 | gimple *stmt = SSA_NAME_DEF_STMT (vuse); |
8b57bfeb JJ |
5710 | basic_block bb = gimple_bb (stmt); |
5711 | if (bb == NULL | |
5712 | || bb == dombb | |
5713 | || !bitmap_set_bit (visited, bb->index) | |
5714 | || !dominated_by_p (CDI_DOMINATORS, bb, dombb)) | |
5715 | continue; | |
5716 | while (1) | |
5717 | { | |
5718 | if (gimple_code (stmt) == GIMPLE_PHI) | |
5719 | { | |
5720 | do_invalidate (dombb, stmt, visited, count); | |
5721 | if (*count == 0) | |
5722 | return; | |
5723 | break; | |
5724 | } | |
5725 | if (--*count == 0) | |
5726 | return; | |
5727 | if (!maybe_invalidate (stmt)) | |
5728 | { | |
5729 | *count = 0; | |
5730 | return; | |
5731 | } | |
5732 | vuse = gimple_vuse (stmt); | |
5733 | stmt = SSA_NAME_DEF_STMT (vuse); | |
5734 | if (gimple_bb (stmt) != bb) | |
5735 | { | |
5736 | bb = gimple_bb (stmt); | |
5737 | if (bb == NULL | |
5738 | || bb == dombb | |
5739 | || !bitmap_set_bit (visited, bb->index) | |
5740 | || !dominated_by_p (CDI_DOMINATORS, bb, dombb)) | |
5741 | break; | |
5742 | } | |
5743 | } | |
5744 | } | |
5745 | } | |
5746 | ||
4d9192b5 TS |
5747 | class strlen_dom_walker : public dom_walker |
5748 | { | |
5749 | public: | |
fa9544ab | 5750 | strlen_dom_walker (cdi_direction direction) |
22fca489 MS |
5751 | : dom_walker (direction), |
5752 | evrp (false), | |
5753 | m_cleanup_cfg (false) | |
fa9544ab | 5754 | {} |
4d9192b5 | 5755 | |
3daacdcd | 5756 | virtual edge before_dom_children (basic_block); |
4d9192b5 | 5757 | virtual void after_dom_children (basic_block); |
fa9544ab | 5758 | |
22fca489 MS |
5759 | /* EVRP analyzer used for printf argument range processing, and |
5760 | to track strlen results across integer variable assignments. */ | |
5761 | evrp_range_analyzer evrp; | |
5762 | ||
fa9544ab ML |
5763 | /* Flag that will trigger TODO_cleanup_cfg to be returned in strlen |
5764 | execute function. */ | |
5765 | bool m_cleanup_cfg; | |
4d9192b5 TS |
5766 | }; |
5767 | ||
8b57bfeb | 5768 | /* Callback for walk_dominator_tree. Attempt to optimize various |
c7880c8c | 5769 | string ops by remembering string lengths pointed by pointer SSA_NAMEs. */ |
8b57bfeb | 5770 | |
3daacdcd | 5771 | edge |
4d9192b5 | 5772 | strlen_dom_walker::before_dom_children (basic_block bb) |
8b57bfeb | 5773 | { |
22fca489 MS |
5774 | evrp.enter (bb); |
5775 | ||
8b57bfeb JJ |
5776 | basic_block dombb = get_immediate_dominator (CDI_DOMINATORS, bb); |
5777 | ||
5778 | if (dombb == NULL) | |
5779 | stridx_to_strinfo = NULL; | |
5780 | else | |
5781 | { | |
526ceb68 | 5782 | stridx_to_strinfo = ((vec<strinfo *, va_heap, vl_embed> *) dombb->aux); |
8b57bfeb JJ |
5783 | if (stridx_to_strinfo) |
5784 | { | |
538dd0b7 DM |
5785 | for (gphi_iterator gsi = gsi_start_phis (bb); !gsi_end_p (gsi); |
5786 | gsi_next (&gsi)) | |
8b57bfeb | 5787 | { |
538dd0b7 | 5788 | gphi *phi = gsi.phi (); |
ea057359 | 5789 | if (virtual_operand_p (gimple_phi_result (phi))) |
8b57bfeb JJ |
5790 | { |
5791 | bitmap visited = BITMAP_ALLOC (NULL); | |
5792 | int count_vdef = 100; | |
5793 | do_invalidate (dombb, phi, visited, &count_vdef); | |
5794 | BITMAP_FREE (visited); | |
8b29fd4e JJ |
5795 | if (count_vdef == 0) |
5796 | { | |
5797 | /* If there were too many vdefs in between immediate | |
5798 | dominator and current bb, invalidate everything. | |
5799 | If stridx_to_strinfo has been unshared, we need | |
5800 | to free it, otherwise just set it to NULL. */ | |
5801 | if (!strinfo_shared ()) | |
5802 | { | |
5803 | unsigned int i; | |
526ceb68 | 5804 | strinfo *si; |
8b29fd4e JJ |
5805 | |
5806 | for (i = 1; | |
5807 | vec_safe_iterate (stridx_to_strinfo, i, &si); | |
5808 | ++i) | |
5809 | { | |
5810 | free_strinfo (si); | |
5811 | (*stridx_to_strinfo)[i] = NULL; | |
5812 | } | |
5813 | } | |
5814 | else | |
5815 | stridx_to_strinfo = NULL; | |
5816 | } | |
8b57bfeb JJ |
5817 | break; |
5818 | } | |
5819 | } | |
5820 | } | |
5821 | } | |
5822 | ||
5823 | /* If all PHI arguments have the same string index, the PHI result | |
5824 | has it as well. */ | |
538dd0b7 DM |
5825 | for (gphi_iterator gsi = gsi_start_phis (bb); !gsi_end_p (gsi); |
5826 | gsi_next (&gsi)) | |
8b57bfeb | 5827 | { |
538dd0b7 | 5828 | gphi *phi = gsi.phi (); |
8b57bfeb | 5829 | tree result = gimple_phi_result (phi); |
ea057359 | 5830 | if (!virtual_operand_p (result) && POINTER_TYPE_P (TREE_TYPE (result))) |
8b57bfeb JJ |
5831 | { |
5832 | int idx = get_stridx (gimple_phi_arg_def (phi, 0)); | |
5833 | if (idx != 0) | |
5834 | { | |
5835 | unsigned int i, n = gimple_phi_num_args (phi); | |
5836 | for (i = 1; i < n; i++) | |
5837 | if (idx != get_stridx (gimple_phi_arg_def (phi, i))) | |
5838 | break; | |
5839 | if (i == n) | |
9771b263 | 5840 | ssa_ver_to_stridx[SSA_NAME_VERSION (result)] = idx; |
8b57bfeb JJ |
5841 | } |
5842 | } | |
5843 | } | |
5844 | ||
fa9544ab ML |
5845 | bool cleanup_eh = false; |
5846 | ||
8b57bfeb | 5847 | /* Attempt to optimize individual statements. */ |
538dd0b7 | 5848 | for (gimple_stmt_iterator gsi = gsi_start_bb (bb); !gsi_end_p (gsi); ) |
22fca489 MS |
5849 | { |
5850 | gimple *stmt = gsi_stmt (gsi); | |
5851 | ||
5852 | /* First record ranges generated by this statement so they | |
5853 | can be used by printf argument processing. */ | |
5854 | evrp.record_ranges_from_stmt (stmt, false); | |
5855 | ||
5856 | if (check_and_optimize_stmt (&gsi, &cleanup_eh, evrp.get_vr_values ())) | |
5857 | gsi_next (&gsi); | |
5858 | } | |
8b57bfeb | 5859 | |
fa9544ab ML |
5860 | if (cleanup_eh && gimple_purge_dead_eh_edges (bb)) |
5861 | m_cleanup_cfg = true; | |
5862 | ||
8b57bfeb | 5863 | bb->aux = stridx_to_strinfo; |
9771b263 | 5864 | if (vec_safe_length (stridx_to_strinfo) && !strinfo_shared ()) |
526ceb68 | 5865 | (*stridx_to_strinfo)[0] = (strinfo *) bb; |
3daacdcd | 5866 | return NULL; |
8b57bfeb JJ |
5867 | } |
5868 | ||
5869 | /* Callback for walk_dominator_tree. Free strinfo vector if it is | |
5870 | owned by the current bb, clear bb->aux. */ | |
5871 | ||
4d9192b5 TS |
5872 | void |
5873 | strlen_dom_walker::after_dom_children (basic_block bb) | |
8b57bfeb | 5874 | { |
22fca489 MS |
5875 | evrp.leave (bb); |
5876 | ||
8b57bfeb JJ |
5877 | if (bb->aux) |
5878 | { | |
526ceb68 | 5879 | stridx_to_strinfo = ((vec<strinfo *, va_heap, vl_embed> *) bb->aux); |
9771b263 | 5880 | if (vec_safe_length (stridx_to_strinfo) |
526ceb68 | 5881 | && (*stridx_to_strinfo)[0] == (strinfo *) bb) |
8b57bfeb JJ |
5882 | { |
5883 | unsigned int i; | |
526ceb68 | 5884 | strinfo *si; |
8b57bfeb | 5885 | |
9771b263 | 5886 | for (i = 1; vec_safe_iterate (stridx_to_strinfo, i, &si); ++i) |
8b57bfeb | 5887 | free_strinfo (si); |
9771b263 | 5888 | vec_free (stridx_to_strinfo); |
8b57bfeb JJ |
5889 | } |
5890 | bb->aux = NULL; | |
5891 | } | |
5892 | } | |
5893 | ||
27a4cd48 DM |
5894 | namespace { |
5895 | ||
22fca489 MS |
5896 | static unsigned int |
5897 | printf_strlen_execute (function *fun, bool warn_only) | |
27a4cd48 | 5898 | { |
22fca489 | 5899 | strlen_optimize = !warn_only; |
27a4cd48 | 5900 | |
be55bfe6 TS |
5901 | calculate_dominance_info (CDI_DOMINATORS); |
5902 | ||
22fca489 MS |
5903 | bool use_scev = optimize > 0 && flag_printf_return_value; |
5904 | if (use_scev) | |
5905 | { | |
5906 | loop_optimizer_init (LOOPS_NORMAL); | |
5907 | scev_initialize (); | |
5908 | } | |
5909 | ||
2d8ba441 JL |
5910 | gcc_assert (!strlen_to_stridx); |
5911 | if (warn_stringop_overflow || warn_stringop_truncation) | |
5912 | strlen_to_stridx = new hash_map<tree, stridx_strlenloc> (); | |
5913 | ||
5914 | /* This has to happen after initializing the loop optimizer | |
5915 | and initializing SCEV as they create new SSA_NAMEs. */ | |
5916 | ssa_ver_to_stridx.safe_grow_cleared (num_ssa_names); | |
5917 | max_stridx = 1; | |
5918 | ||
be55bfe6 TS |
5919 | /* String length optimization is implemented as a walk of the dominator |
5920 | tree and a forward walk of statements within each block. */ | |
fa9544ab | 5921 | strlen_dom_walker walker (CDI_DOMINATORS); |
22fca489 | 5922 | walker.walk (ENTRY_BLOCK_PTR_FOR_FN (fun)); |
be55bfe6 TS |
5923 | |
5924 | ssa_ver_to_stridx.release (); | |
33e7d32e | 5925 | strinfo_pool.release (); |
c203e8a7 | 5926 | if (decl_to_stridxlist_htab) |
be55bfe6 TS |
5927 | { |
5928 | obstack_free (&stridx_obstack, NULL); | |
c203e8a7 TS |
5929 | delete decl_to_stridxlist_htab; |
5930 | decl_to_stridxlist_htab = NULL; | |
be55bfe6 TS |
5931 | } |
5932 | laststmt.stmt = NULL; | |
5933 | laststmt.len = NULL_TREE; | |
5934 | laststmt.stridx = 0; | |
5935 | ||
6a33d0ff MS |
5936 | if (strlen_to_stridx) |
5937 | { | |
5938 | strlen_to_stridx->empty (); | |
5939 | delete strlen_to_stridx; | |
5940 | strlen_to_stridx = NULL; | |
5941 | } | |
025d57f0 | 5942 | |
22fca489 MS |
5943 | if (use_scev) |
5944 | { | |
5945 | scev_finalize (); | |
5946 | loop_optimizer_finalize (); | |
5947 | } | |
5948 | ||
5949 | /* Clean up object size info. */ | |
5950 | fini_object_sizes (); | |
5951 | ||
fa9544ab | 5952 | return walker.m_cleanup_cfg ? TODO_cleanup_cfg : 0; |
be55bfe6 TS |
5953 | } |
5954 | ||
22fca489 MS |
5955 | /* This file defines two passes: one for warnings that runs only when |
5956 | optimization is disabled, and another that implements optimizations | |
5957 | and also issues warnings. */ | |
5958 | ||
5959 | const pass_data pass_data_warn_printf = | |
5960 | { | |
5961 | GIMPLE_PASS, /* type */ | |
5962 | "warn-printf", /* name */ | |
5963 | OPTGROUP_NONE, /* optinfo_flags */ | |
5964 | TV_NONE, /* tv_id */ | |
5965 | /* Normally an optimization pass would require PROP_ssa but because | |
5966 | this pass runs early, with no optimization, to do sprintf format | |
5967 | checking, it only requires PROP_cfg. */ | |
5968 | PROP_cfg, /* properties_required */ | |
5969 | 0, /* properties_provided */ | |
5970 | 0, /* properties_destroyed */ | |
5971 | 0, /* todo_flags_start */ | |
5972 | 0, /* todo_flags_finish */ | |
5973 | }; | |
5974 | ||
5975 | class pass_warn_printf : public gimple_opt_pass | |
5976 | { | |
5977 | public: | |
5978 | pass_warn_printf (gcc::context *ctxt) | |
5979 | : gimple_opt_pass (pass_data_warn_printf, ctxt) | |
5980 | {} | |
5981 | ||
5982 | virtual bool gate (function *); | |
5983 | virtual unsigned int execute (function *fun) | |
5984 | { | |
5985 | return printf_strlen_execute (fun, true); | |
5986 | } | |
5987 | }; | |
5988 | ||
5989 | ||
5990 | /* Return true to run the warning pass only when not optimizing and | |
5991 | iff either -Wformat-overflow or -Wformat-truncation is specified. */ | |
5992 | ||
5993 | bool | |
5994 | pass_warn_printf::gate (function *) | |
5995 | { | |
5996 | return !optimize && (warn_format_overflow > 0 || warn_format_trunc > 0); | |
5997 | } | |
5998 | ||
5999 | const pass_data pass_data_strlen = | |
6000 | { | |
6001 | GIMPLE_PASS, /* type */ | |
6002 | "strlen", /* name */ | |
6003 | OPTGROUP_NONE, /* optinfo_flags */ | |
6004 | TV_TREE_STRLEN, /* tv_id */ | |
6005 | PROP_cfg | PROP_ssa, /* properties_required */ | |
6006 | 0, /* properties_provided */ | |
6007 | 0, /* properties_destroyed */ | |
6008 | 0, /* todo_flags_start */ | |
6009 | 0, /* todo_flags_finish */ | |
6010 | }; | |
6011 | ||
6012 | class pass_strlen : public gimple_opt_pass | |
6013 | { | |
6014 | public: | |
6015 | pass_strlen (gcc::context *ctxt) | |
6016 | : gimple_opt_pass (pass_data_strlen, ctxt) | |
6017 | {} | |
6018 | ||
6019 | opt_pass * clone () { return new pass_strlen (m_ctxt); } | |
6020 | ||
6021 | virtual bool gate (function *); | |
6022 | virtual unsigned int execute (function *fun) | |
6023 | { | |
6024 | return printf_strlen_execute (fun, false); | |
6025 | } | |
6026 | }; | |
6027 | ||
6028 | /* Return true to run the pass only when the sprintf and/or strlen | |
6029 | optimizations are enabled and -Wformat-overflow or -Wformat-truncation | |
6030 | are specified. */ | |
6031 | ||
6032 | bool | |
6033 | pass_strlen::gate (function *) | |
6034 | { | |
6035 | return ((warn_format_overflow > 0 | |
6036 | || warn_format_trunc > 0 | |
937a86b4 | 6037 | || warn_restrict > 0 |
22fca489 MS |
6038 | || flag_optimize_strlen > 0 |
6039 | || flag_printf_return_value) | |
6040 | && optimize > 0); | |
6041 | } | |
6042 | ||
27a4cd48 DM |
6043 | } // anon namespace |
6044 | ||
22fca489 MS |
6045 | gimple_opt_pass * |
6046 | make_pass_warn_printf (gcc::context *ctxt) | |
6047 | { | |
6048 | return new pass_warn_printf (ctxt); | |
6049 | } | |
6050 | ||
27a4cd48 DM |
6051 | gimple_opt_pass * |
6052 | make_pass_strlen (gcc::context *ctxt) | |
6053 | { | |
6054 | return new pass_strlen (ctxt); | |
6055 | } |