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8b57bfeb | 1 | /* String length optimization |
85ec4feb | 2 | Copyright (C) 2011-2018 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" |
8b57bfeb | 48 | #include "params.h" |
910ee068 | 49 | #include "tree-hash-traits.h" |
8b0b334a | 50 | #include "tree-object-size.h" |
36b85e43 | 51 | #include "builtins.h" |
e0bd6c9f | 52 | #include "target.h" |
025d57f0 MS |
53 | #include "diagnostic-core.h" |
54 | #include "diagnostic.h" | |
55 | #include "intl.h" | |
56 | #include "attribs.h" | |
6a33d0ff | 57 | #include "calls.h" |
8b57bfeb JJ |
58 | |
59 | /* A vector indexed by SSA_NAME_VERSION. 0 means unknown, positive value | |
60 | is an index into strinfo vector, negative value stands for | |
61 | string length of a string literal (~strlen). */ | |
9771b263 | 62 | static vec<int> ssa_ver_to_stridx; |
8b57bfeb JJ |
63 | |
64 | /* Number of currently active string indexes plus one. */ | |
65 | static int max_stridx; | |
66 | ||
67 | /* String information record. */ | |
526ceb68 | 68 | struct strinfo |
8b57bfeb | 69 | { |
e3f9a279 RS |
70 | /* Number of leading characters that are known to be nonzero. This is |
71 | also the length of the string if FULL_STRING_P. | |
72 | ||
73 | The values in a list of related string pointers must be consistent; | |
74 | that is, if strinfo B comes X bytes after strinfo A, it must be | |
75 | the case that A->nonzero_chars == X + B->nonzero_chars. */ | |
76 | tree nonzero_chars; | |
8b57bfeb JJ |
77 | /* Any of the corresponding pointers for querying alias oracle. */ |
78 | tree ptr; | |
862088aa RS |
79 | /* This is used for two things: |
80 | ||
81 | - To record the statement that should be used for delayed length | |
82 | computations. We maintain the invariant that all related strinfos | |
83 | have delayed lengths or none do. | |
84 | ||
85 | - To record the malloc or calloc call that produced this result. */ | |
355fe088 | 86 | gimple *stmt; |
8b57bfeb JJ |
87 | /* Pointer to '\0' if known, if NULL, it can be computed as |
88 | ptr + length. */ | |
89 | tree endptr; | |
90 | /* Reference count. Any changes to strinfo entry possibly shared | |
91 | with dominating basic blocks need unshare_strinfo first, except | |
92 | for dont_invalidate which affects only the immediately next | |
93 | maybe_invalidate. */ | |
94 | int refcount; | |
95 | /* Copy of index. get_strinfo (si->idx) should return si; */ | |
96 | int idx; | |
97 | /* These 3 fields are for chaining related string pointers together. | |
98 | E.g. for | |
99 | bl = strlen (b); dl = strlen (d); strcpy (a, b); c = a + bl; | |
100 | strcpy (c, d); e = c + dl; | |
101 | strinfo(a) -> strinfo(c) -> strinfo(e) | |
102 | All have ->first field equal to strinfo(a)->idx and are doubly | |
103 | chained through prev/next fields. The later strinfos are required | |
104 | to point into the same string with zero or more bytes after | |
105 | the previous pointer and all bytes in between the two pointers | |
106 | must be non-zero. Functions like strcpy or memcpy are supposed | |
107 | to adjust all previous strinfo lengths, but not following strinfo | |
108 | lengths (those are uncertain, usually invalidated during | |
109 | maybe_invalidate, except when the alias oracle knows better). | |
110 | Functions like strcat on the other side adjust the whole | |
111 | related strinfo chain. | |
112 | They are updated lazily, so to use the chain the same first fields | |
113 | and si->prev->next == si->idx needs to be verified. */ | |
114 | int first; | |
115 | int next; | |
116 | int prev; | |
117 | /* A flag whether the string is known to be written in the current | |
118 | function. */ | |
119 | bool writable; | |
120 | /* A flag for the next maybe_invalidate that this strinfo shouldn't | |
121 | be invalidated. Always cleared by maybe_invalidate. */ | |
122 | bool dont_invalidate; | |
e3f9a279 RS |
123 | /* True if the string is known to be nul-terminated after NONZERO_CHARS |
124 | characters. False is useful when detecting strings that are built | |
125 | up via successive memcpys. */ | |
126 | bool full_string_p; | |
526ceb68 | 127 | }; |
8b57bfeb JJ |
128 | |
129 | /* Pool for allocating strinfo_struct entries. */ | |
526ceb68 | 130 | static object_allocator<strinfo> strinfo_pool ("strinfo pool"); |
8b57bfeb JJ |
131 | |
132 | /* Vector mapping positive string indexes to strinfo, for the | |
133 | current basic block. The first pointer in the vector is special, | |
134 | it is either NULL, meaning the vector isn't shared, or it is | |
135 | a basic block pointer to the owner basic_block if shared. | |
136 | If some other bb wants to modify the vector, the vector needs | |
137 | to be unshared first, and only the owner bb is supposed to free it. */ | |
526ceb68 | 138 | static vec<strinfo *, va_heap, vl_embed> *stridx_to_strinfo; |
8b57bfeb JJ |
139 | |
140 | /* One OFFSET->IDX mapping. */ | |
141 | struct stridxlist | |
142 | { | |
143 | struct stridxlist *next; | |
144 | HOST_WIDE_INT offset; | |
145 | int idx; | |
146 | }; | |
147 | ||
148 | /* Hash table entry, mapping a DECL to a chain of OFFSET->IDX mappings. */ | |
149 | struct decl_stridxlist_map | |
150 | { | |
151 | struct tree_map_base base; | |
152 | struct stridxlist list; | |
153 | }; | |
154 | ||
155 | /* Hash table for mapping decls to a chained list of offset -> idx | |
156 | mappings. */ | |
fb5c464a | 157 | static hash_map<tree_decl_hash, stridxlist> *decl_to_stridxlist_htab; |
8b57bfeb | 158 | |
6a33d0ff MS |
159 | /* Hash table mapping strlen calls to stridx instances describing |
160 | the calls' arguments. Non-null only when warn_stringop_truncation | |
161 | is non-zero. */ | |
025d57f0 | 162 | typedef std::pair<int, location_t> stridx_strlenloc; |
6a33d0ff | 163 | static hash_map<tree, stridx_strlenloc> *strlen_to_stridx; |
025d57f0 | 164 | |
8b57bfeb JJ |
165 | /* Obstack for struct stridxlist and struct decl_stridxlist_map. */ |
166 | static struct obstack stridx_obstack; | |
167 | ||
168 | /* Last memcpy statement if it could be adjusted if the trailing | |
169 | '\0' written is immediately overwritten, or | |
170 | *x = '\0' store that could be removed if it is immediately overwritten. */ | |
171 | struct laststmt_struct | |
172 | { | |
355fe088 | 173 | gimple *stmt; |
8b57bfeb JJ |
174 | tree len; |
175 | int stridx; | |
176 | } laststmt; | |
177 | ||
e3f9a279 | 178 | static int get_stridx_plus_constant (strinfo *, unsigned HOST_WIDE_INT, tree); |
cc8bea0a | 179 | static void handle_builtin_stxncpy (built_in_function, gimple_stmt_iterator *); |
e3f9a279 RS |
180 | |
181 | /* Return: | |
182 | ||
183 | - 1 if SI is known to start with more than OFF nonzero characters. | |
184 | ||
185 | - 0 if SI is known to start with OFF nonzero characters, | |
186 | but is not known to start with more. | |
187 | ||
188 | - -1 if SI might not start with OFF nonzero characters. */ | |
189 | ||
190 | static inline int | |
191 | compare_nonzero_chars (strinfo *si, unsigned HOST_WIDE_INT off) | |
192 | { | |
193 | if (si->nonzero_chars | |
194 | && TREE_CODE (si->nonzero_chars) == INTEGER_CST) | |
195 | return compare_tree_int (si->nonzero_chars, off); | |
196 | else | |
197 | return -1; | |
198 | } | |
199 | ||
200 | /* Return true if SI is known to be a zero-length string. */ | |
201 | ||
202 | static inline bool | |
203 | zero_length_string_p (strinfo *si) | |
204 | { | |
205 | return si->full_string_p && integer_zerop (si->nonzero_chars); | |
206 | } | |
204a913b JJ |
207 | |
208 | /* Return strinfo vector entry IDX. */ | |
209 | ||
526ceb68 | 210 | static inline strinfo * |
204a913b JJ |
211 | get_strinfo (int idx) |
212 | { | |
213 | if (vec_safe_length (stridx_to_strinfo) <= (unsigned int) idx) | |
214 | return NULL; | |
215 | return (*stridx_to_strinfo)[idx]; | |
216 | } | |
217 | ||
bde63fde RS |
218 | /* Get the next strinfo in the chain after SI, or null if none. */ |
219 | ||
220 | static inline strinfo * | |
221 | get_next_strinfo (strinfo *si) | |
222 | { | |
223 | if (si->next == 0) | |
224 | return NULL; | |
225 | strinfo *nextsi = get_strinfo (si->next); | |
226 | if (nextsi == NULL || nextsi->first != si->first || nextsi->prev != si->idx) | |
227 | return NULL; | |
228 | return nextsi; | |
229 | } | |
230 | ||
e3f9a279 RS |
231 | /* Helper function for get_stridx. Return the strinfo index of the address |
232 | of EXP, which is available in PTR if nonnull. If OFFSET_OUT, it is | |
233 | OK to return the index for some X <= &EXP and store &EXP - X in | |
234 | *OFFSET_OUT. */ | |
8b57bfeb JJ |
235 | |
236 | static int | |
e3f9a279 | 237 | get_addr_stridx (tree exp, tree ptr, unsigned HOST_WIDE_INT *offset_out) |
8b57bfeb JJ |
238 | { |
239 | HOST_WIDE_INT off; | |
5f3cd7c3 | 240 | struct stridxlist *list, *last = NULL; |
8b57bfeb JJ |
241 | tree base; |
242 | ||
c203e8a7 | 243 | if (!decl_to_stridxlist_htab) |
8b57bfeb JJ |
244 | return 0; |
245 | ||
a90c8804 RS |
246 | poly_int64 poff; |
247 | base = get_addr_base_and_unit_offset (exp, &poff); | |
248 | if (base == NULL || !DECL_P (base) || !poff.is_constant (&off)) | |
8b57bfeb JJ |
249 | return 0; |
250 | ||
1eb68d2d TS |
251 | list = decl_to_stridxlist_htab->get (base); |
252 | if (list == NULL) | |
8b57bfeb JJ |
253 | return 0; |
254 | ||
8b57bfeb JJ |
255 | do |
256 | { | |
257 | if (list->offset == off) | |
e3f9a279 RS |
258 | { |
259 | if (offset_out) | |
260 | *offset_out = 0; | |
261 | return list->idx; | |
262 | } | |
5f3cd7c3 JJ |
263 | if (list->offset > off) |
264 | return 0; | |
265 | last = list; | |
8b57bfeb JJ |
266 | list = list->next; |
267 | } | |
268 | while (list); | |
5f3cd7c3 | 269 | |
e3f9a279 | 270 | if ((offset_out || ptr) && last && last->idx > 0) |
5f3cd7c3 | 271 | { |
e3f9a279 RS |
272 | unsigned HOST_WIDE_INT rel_off |
273 | = (unsigned HOST_WIDE_INT) off - last->offset; | |
5f3cd7c3 | 274 | strinfo *si = get_strinfo (last->idx); |
e3f9a279 RS |
275 | if (si && compare_nonzero_chars (si, rel_off) >= 0) |
276 | { | |
277 | if (offset_out) | |
278 | { | |
279 | *offset_out = rel_off; | |
280 | return last->idx; | |
281 | } | |
282 | else | |
283 | return get_stridx_plus_constant (si, rel_off, ptr); | |
284 | } | |
5f3cd7c3 | 285 | } |
8b57bfeb JJ |
286 | return 0; |
287 | } | |
288 | ||
289 | /* Return string index for EXP. */ | |
290 | ||
291 | static int | |
292 | get_stridx (tree exp) | |
293 | { | |
b3c3685a | 294 | tree s, o; |
8b57bfeb JJ |
295 | |
296 | if (TREE_CODE (exp) == SSA_NAME) | |
204a913b JJ |
297 | { |
298 | if (ssa_ver_to_stridx[SSA_NAME_VERSION (exp)]) | |
299 | return ssa_ver_to_stridx[SSA_NAME_VERSION (exp)]; | |
300 | int i; | |
301 | tree e = exp; | |
302 | HOST_WIDE_INT off = 0; | |
303 | for (i = 0; i < 5; i++) | |
304 | { | |
355fe088 | 305 | gimple *def_stmt = SSA_NAME_DEF_STMT (e); |
204a913b JJ |
306 | if (!is_gimple_assign (def_stmt) |
307 | || gimple_assign_rhs_code (def_stmt) != POINTER_PLUS_EXPR) | |
308 | return 0; | |
309 | tree rhs1 = gimple_assign_rhs1 (def_stmt); | |
310 | tree rhs2 = gimple_assign_rhs2 (def_stmt); | |
311 | if (TREE_CODE (rhs1) != SSA_NAME | |
312 | || !tree_fits_shwi_p (rhs2)) | |
313 | return 0; | |
314 | HOST_WIDE_INT this_off = tree_to_shwi (rhs2); | |
315 | if (this_off < 0) | |
316 | return 0; | |
317 | off = (unsigned HOST_WIDE_INT) off + this_off; | |
318 | if (off < 0) | |
319 | return 0; | |
320 | if (ssa_ver_to_stridx[SSA_NAME_VERSION (rhs1)]) | |
321 | { | |
526ceb68 | 322 | strinfo *si |
204a913b | 323 | = get_strinfo (ssa_ver_to_stridx[SSA_NAME_VERSION (rhs1)]); |
e3f9a279 | 324 | if (si && compare_nonzero_chars (si, off) >= 0) |
204a913b JJ |
325 | return get_stridx_plus_constant (si, off, exp); |
326 | } | |
327 | e = rhs1; | |
328 | } | |
329 | return 0; | |
330 | } | |
8b57bfeb JJ |
331 | |
332 | if (TREE_CODE (exp) == ADDR_EXPR) | |
333 | { | |
e3f9a279 | 334 | int idx = get_addr_stridx (TREE_OPERAND (exp, 0), exp, NULL); |
8b57bfeb JJ |
335 | if (idx != 0) |
336 | return idx; | |
337 | } | |
338 | ||
b3c3685a JJ |
339 | s = string_constant (exp, &o); |
340 | if (s != NULL_TREE | |
9541ffee | 341 | && (o == NULL_TREE || tree_fits_shwi_p (o)) |
b3c3685a | 342 | && TREE_STRING_LENGTH (s) > 0) |
8b57bfeb | 343 | { |
9439e9a1 | 344 | HOST_WIDE_INT offset = o ? tree_to_shwi (o) : 0; |
b3c3685a JJ |
345 | const char *p = TREE_STRING_POINTER (s); |
346 | int max = TREE_STRING_LENGTH (s) - 1; | |
347 | ||
348 | if (p[max] == '\0' && offset >= 0 && offset <= max) | |
349 | return ~(int) strlen (p + offset); | |
8b57bfeb JJ |
350 | } |
351 | return 0; | |
352 | } | |
353 | ||
354 | /* Return true if strinfo vector is shared with the immediate dominator. */ | |
355 | ||
356 | static inline bool | |
357 | strinfo_shared (void) | |
358 | { | |
9771b263 DN |
359 | return vec_safe_length (stridx_to_strinfo) |
360 | && (*stridx_to_strinfo)[0] != NULL; | |
8b57bfeb JJ |
361 | } |
362 | ||
363 | /* Unshare strinfo vector that is shared with the immediate dominator. */ | |
364 | ||
365 | static void | |
366 | unshare_strinfo_vec (void) | |
367 | { | |
526ceb68 | 368 | strinfo *si; |
8b57bfeb JJ |
369 | unsigned int i = 0; |
370 | ||
371 | gcc_assert (strinfo_shared ()); | |
9771b263 DN |
372 | stridx_to_strinfo = vec_safe_copy (stridx_to_strinfo); |
373 | for (i = 1; vec_safe_iterate (stridx_to_strinfo, i, &si); ++i) | |
8b57bfeb JJ |
374 | if (si != NULL) |
375 | si->refcount++; | |
9771b263 | 376 | (*stridx_to_strinfo)[0] = NULL; |
8b57bfeb JJ |
377 | } |
378 | ||
379 | /* Attempt to create a string index for exp, ADDR_EXPR's operand. | |
380 | Return a pointer to the location where the string index can | |
381 | be stored (if 0) or is stored, or NULL if this can't be tracked. */ | |
382 | ||
383 | static int * | |
384 | addr_stridxptr (tree exp) | |
385 | { | |
8b57bfeb JJ |
386 | HOST_WIDE_INT off; |
387 | ||
a90c8804 RS |
388 | poly_int64 poff; |
389 | tree base = get_addr_base_and_unit_offset (exp, &poff); | |
390 | if (base == NULL_TREE || !DECL_P (base) || !poff.is_constant (&off)) | |
8b57bfeb JJ |
391 | return NULL; |
392 | ||
c203e8a7 | 393 | if (!decl_to_stridxlist_htab) |
8b57bfeb | 394 | { |
1eb68d2d | 395 | decl_to_stridxlist_htab |
fb5c464a | 396 | = new hash_map<tree_decl_hash, stridxlist> (64); |
8b57bfeb JJ |
397 | gcc_obstack_init (&stridx_obstack); |
398 | } | |
1eb68d2d TS |
399 | |
400 | bool existed; | |
401 | stridxlist *list = &decl_to_stridxlist_htab->get_or_insert (base, &existed); | |
402 | if (existed) | |
8b57bfeb JJ |
403 | { |
404 | int i; | |
5f3cd7c3 JJ |
405 | stridxlist *before = NULL; |
406 | for (i = 0; i < 32; i++) | |
8b57bfeb JJ |
407 | { |
408 | if (list->offset == off) | |
409 | return &list->idx; | |
5f3cd7c3 JJ |
410 | if (list->offset > off && before == NULL) |
411 | before = list; | |
8b57bfeb JJ |
412 | if (list->next == NULL) |
413 | break; | |
5f3cd7c3 | 414 | list = list->next; |
8b57bfeb | 415 | } |
5f3cd7c3 | 416 | if (i == 32) |
8b57bfeb | 417 | return NULL; |
5f3cd7c3 JJ |
418 | if (before) |
419 | { | |
420 | list = before; | |
421 | before = XOBNEW (&stridx_obstack, struct stridxlist); | |
422 | *before = *list; | |
423 | list->next = before; | |
424 | list->offset = off; | |
425 | list->idx = 0; | |
426 | return &list->idx; | |
427 | } | |
8b57bfeb JJ |
428 | list->next = XOBNEW (&stridx_obstack, struct stridxlist); |
429 | list = list->next; | |
430 | } | |
1eb68d2d | 431 | |
8b57bfeb JJ |
432 | list->next = NULL; |
433 | list->offset = off; | |
434 | list->idx = 0; | |
435 | return &list->idx; | |
436 | } | |
437 | ||
438 | /* Create a new string index, or return 0 if reached limit. */ | |
439 | ||
440 | static int | |
441 | new_stridx (tree exp) | |
442 | { | |
443 | int idx; | |
444 | if (max_stridx >= PARAM_VALUE (PARAM_MAX_TRACKED_STRLENS)) | |
445 | return 0; | |
446 | if (TREE_CODE (exp) == SSA_NAME) | |
447 | { | |
448 | if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (exp)) | |
449 | return 0; | |
450 | idx = max_stridx++; | |
9771b263 | 451 | ssa_ver_to_stridx[SSA_NAME_VERSION (exp)] = idx; |
8b57bfeb JJ |
452 | return idx; |
453 | } | |
454 | if (TREE_CODE (exp) == ADDR_EXPR) | |
455 | { | |
456 | int *pidx = addr_stridxptr (TREE_OPERAND (exp, 0)); | |
457 | if (pidx != NULL) | |
458 | { | |
459 | gcc_assert (*pidx == 0); | |
460 | *pidx = max_stridx++; | |
461 | return *pidx; | |
462 | } | |
463 | } | |
464 | return 0; | |
465 | } | |
466 | ||
467 | /* Like new_stridx, but for ADDR_EXPR's operand instead. */ | |
468 | ||
469 | static int | |
470 | new_addr_stridx (tree exp) | |
471 | { | |
472 | int *pidx; | |
473 | if (max_stridx >= PARAM_VALUE (PARAM_MAX_TRACKED_STRLENS)) | |
474 | return 0; | |
475 | pidx = addr_stridxptr (exp); | |
476 | if (pidx != NULL) | |
477 | { | |
478 | gcc_assert (*pidx == 0); | |
479 | *pidx = max_stridx++; | |
480 | return *pidx; | |
481 | } | |
482 | return 0; | |
483 | } | |
484 | ||
485 | /* Create a new strinfo. */ | |
486 | ||
526ceb68 | 487 | static strinfo * |
e3f9a279 | 488 | new_strinfo (tree ptr, int idx, tree nonzero_chars, bool full_string_p) |
8b57bfeb | 489 | { |
526ceb68 | 490 | strinfo *si = strinfo_pool.allocate (); |
e3f9a279 | 491 | si->nonzero_chars = nonzero_chars; |
8b57bfeb JJ |
492 | si->ptr = ptr; |
493 | si->stmt = NULL; | |
494 | si->endptr = NULL_TREE; | |
495 | si->refcount = 1; | |
496 | si->idx = idx; | |
497 | si->first = 0; | |
498 | si->prev = 0; | |
499 | si->next = 0; | |
500 | si->writable = false; | |
501 | si->dont_invalidate = false; | |
e3f9a279 | 502 | si->full_string_p = full_string_p; |
8b57bfeb JJ |
503 | return si; |
504 | } | |
505 | ||
506 | /* Decrease strinfo refcount and free it if not referenced anymore. */ | |
507 | ||
508 | static inline void | |
526ceb68 | 509 | free_strinfo (strinfo *si) |
8b57bfeb JJ |
510 | { |
511 | if (si && --si->refcount == 0) | |
33e7d32e | 512 | strinfo_pool.remove (si); |
8b57bfeb JJ |
513 | } |
514 | ||
8b57bfeb JJ |
515 | /* Set strinfo in the vector entry IDX to SI. */ |
516 | ||
517 | static inline void | |
526ceb68 | 518 | set_strinfo (int idx, strinfo *si) |
8b57bfeb | 519 | { |
9771b263 | 520 | if (vec_safe_length (stridx_to_strinfo) && (*stridx_to_strinfo)[0]) |
8b57bfeb | 521 | unshare_strinfo_vec (); |
9771b263 DN |
522 | if (vec_safe_length (stridx_to_strinfo) <= (unsigned int) idx) |
523 | vec_safe_grow_cleared (stridx_to_strinfo, idx + 1); | |
524 | (*stridx_to_strinfo)[idx] = si; | |
8b57bfeb JJ |
525 | } |
526 | ||
862088aa RS |
527 | /* Return the first strinfo in the related strinfo chain |
528 | if all strinfos in between belong to the chain, otherwise NULL. */ | |
529 | ||
530 | static strinfo * | |
531 | verify_related_strinfos (strinfo *origsi) | |
532 | { | |
533 | strinfo *si = origsi, *psi; | |
534 | ||
535 | if (origsi->first == 0) | |
536 | return NULL; | |
537 | for (; si->prev; si = psi) | |
538 | { | |
539 | if (si->first != origsi->first) | |
540 | return NULL; | |
541 | psi = get_strinfo (si->prev); | |
542 | if (psi == NULL) | |
543 | return NULL; | |
544 | if (psi->next != si->idx) | |
545 | return NULL; | |
546 | } | |
547 | if (si->idx != si->first) | |
548 | return NULL; | |
549 | return si; | |
550 | } | |
551 | ||
552 | /* Set SI's endptr to ENDPTR and compute its length based on SI->ptr. | |
553 | Use LOC for folding. */ | |
554 | ||
555 | static void | |
556 | set_endptr_and_length (location_t loc, strinfo *si, tree endptr) | |
557 | { | |
558 | si->endptr = endptr; | |
559 | si->stmt = NULL; | |
560 | tree start_as_size = fold_convert_loc (loc, size_type_node, si->ptr); | |
561 | tree end_as_size = fold_convert_loc (loc, size_type_node, endptr); | |
e3f9a279 RS |
562 | si->nonzero_chars = fold_build2_loc (loc, MINUS_EXPR, size_type_node, |
563 | end_as_size, start_as_size); | |
564 | si->full_string_p = true; | |
862088aa RS |
565 | } |
566 | ||
8b57bfeb JJ |
567 | /* Return string length, or NULL if it can't be computed. */ |
568 | ||
569 | static tree | |
526ceb68 | 570 | get_string_length (strinfo *si) |
8b57bfeb | 571 | { |
e3f9a279 RS |
572 | if (si->nonzero_chars) |
573 | return si->full_string_p ? si->nonzero_chars : NULL; | |
8b57bfeb JJ |
574 | |
575 | if (si->stmt) | |
576 | { | |
355fe088 | 577 | gimple *stmt = si->stmt, *lenstmt; |
83d5977e | 578 | tree callee, lhs, fn, tem; |
8b57bfeb JJ |
579 | location_t loc; |
580 | gimple_stmt_iterator gsi; | |
581 | ||
582 | gcc_assert (is_gimple_call (stmt)); | |
583 | callee = gimple_call_fndecl (stmt); | |
584 | gcc_assert (callee && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL); | |
585 | lhs = gimple_call_lhs (stmt); | |
8b57bfeb JJ |
586 | /* unshare_strinfo is intentionally not called here. The (delayed) |
587 | transformation of strcpy or strcat into stpcpy is done at the place | |
588 | of the former strcpy/strcat call and so can affect all the strinfos | |
589 | with the same stmt. If they were unshared before and transformation | |
590 | has been already done, the handling of BUILT_IN_STPCPY{,_CHK} should | |
591 | just compute the right length. */ | |
592 | switch (DECL_FUNCTION_CODE (callee)) | |
593 | { | |
594 | case BUILT_IN_STRCAT: | |
595 | case BUILT_IN_STRCAT_CHK: | |
596 | gsi = gsi_for_stmt (stmt); | |
e79983f4 | 597 | fn = builtin_decl_implicit (BUILT_IN_STRLEN); |
8b57bfeb | 598 | gcc_assert (lhs == NULL_TREE); |
8b57bfeb | 599 | tem = unshare_expr (gimple_call_arg (stmt, 0)); |
31db0fe0 | 600 | lenstmt = gimple_build_call (fn, 1, tem); |
83d5977e | 601 | lhs = make_ssa_name (TREE_TYPE (TREE_TYPE (fn)), lenstmt); |
8b57bfeb JJ |
602 | gimple_call_set_lhs (lenstmt, lhs); |
603 | gimple_set_vuse (lenstmt, gimple_vuse (stmt)); | |
604 | gsi_insert_before (&gsi, lenstmt, GSI_SAME_STMT); | |
8b57bfeb | 605 | tem = gimple_call_arg (stmt, 0); |
33960e2e TG |
606 | if (!ptrofftype_p (TREE_TYPE (lhs))) |
607 | { | |
608 | lhs = convert_to_ptrofftype (lhs); | |
609 | lhs = force_gimple_operand_gsi (&gsi, lhs, true, NULL_TREE, | |
610 | true, GSI_SAME_STMT); | |
611 | } | |
0d0e4a03 JJ |
612 | lenstmt = gimple_build_assign |
613 | (make_ssa_name (TREE_TYPE (gimple_call_arg (stmt, 0))), | |
614 | POINTER_PLUS_EXPR,tem, lhs); | |
8b57bfeb JJ |
615 | gsi_insert_before (&gsi, lenstmt, GSI_SAME_STMT); |
616 | gimple_call_set_arg (stmt, 0, gimple_assign_lhs (lenstmt)); | |
617 | lhs = NULL_TREE; | |
618 | /* FALLTHRU */ | |
619 | case BUILT_IN_STRCPY: | |
2dcab30b | 620 | case BUILT_IN_STRCPY_CHK: |
1e762c6a | 621 | gcc_assert (builtin_decl_implicit_p (BUILT_IN_STPCPY)); |
2dcab30b ML |
622 | if (gimple_call_num_args (stmt) == 2) |
623 | fn = builtin_decl_implicit (BUILT_IN_STPCPY); | |
624 | else | |
625 | fn = builtin_decl_explicit (BUILT_IN_STPCPY_CHK); | |
8b57bfeb JJ |
626 | gcc_assert (lhs == NULL_TREE); |
627 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
628 | { | |
629 | fprintf (dump_file, "Optimizing: "); | |
630 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
631 | } | |
632 | gimple_call_set_fndecl (stmt, fn); | |
83d5977e | 633 | lhs = make_ssa_name (TREE_TYPE (TREE_TYPE (fn)), stmt); |
8b57bfeb JJ |
634 | gimple_call_set_lhs (stmt, lhs); |
635 | update_stmt (stmt); | |
636 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
637 | { | |
638 | fprintf (dump_file, "into: "); | |
639 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
640 | } | |
641 | /* FALLTHRU */ | |
642 | case BUILT_IN_STPCPY: | |
643 | case BUILT_IN_STPCPY_CHK: | |
644 | gcc_assert (lhs != NULL_TREE); | |
645 | loc = gimple_location (stmt); | |
862088aa RS |
646 | set_endptr_and_length (loc, si, lhs); |
647 | for (strinfo *chainsi = verify_related_strinfos (si); | |
648 | chainsi != NULL; | |
649 | chainsi = get_next_strinfo (chainsi)) | |
e3f9a279 | 650 | if (chainsi->nonzero_chars == NULL) |
862088aa | 651 | set_endptr_and_length (loc, chainsi, lhs); |
8b57bfeb | 652 | break; |
24314386 MG |
653 | case BUILT_IN_MALLOC: |
654 | break; | |
e3f9a279 | 655 | /* BUILT_IN_CALLOC always has si->nonzero_chars set. */ |
8b57bfeb JJ |
656 | default: |
657 | gcc_unreachable (); | |
658 | break; | |
659 | } | |
660 | } | |
661 | ||
e3f9a279 | 662 | return si->nonzero_chars; |
8b57bfeb JJ |
663 | } |
664 | ||
665 | /* Invalidate string length information for strings whose length | |
666 | might change due to stores in stmt. */ | |
667 | ||
668 | static bool | |
355fe088 | 669 | maybe_invalidate (gimple *stmt) |
8b57bfeb | 670 | { |
526ceb68 | 671 | strinfo *si; |
8b57bfeb JJ |
672 | unsigned int i; |
673 | bool nonempty = false; | |
674 | ||
9771b263 | 675 | for (i = 1; vec_safe_iterate (stridx_to_strinfo, i, &si); ++i) |
8b57bfeb JJ |
676 | if (si != NULL) |
677 | { | |
678 | if (!si->dont_invalidate) | |
679 | { | |
680 | ao_ref r; | |
e3f9a279 | 681 | /* Do not use si->nonzero_chars. */ |
8b57bfeb JJ |
682 | ao_ref_init_from_ptr_and_size (&r, si->ptr, NULL_TREE); |
683 | if (stmt_may_clobber_ref_p_1 (stmt, &r)) | |
684 | { | |
685 | set_strinfo (i, NULL); | |
686 | free_strinfo (si); | |
687 | continue; | |
688 | } | |
689 | } | |
690 | si->dont_invalidate = false; | |
691 | nonempty = true; | |
692 | } | |
693 | return nonempty; | |
694 | } | |
695 | ||
204a913b | 696 | /* Unshare strinfo record SI, if it has refcount > 1 or |
8b57bfeb JJ |
697 | if stridx_to_strinfo vector is shared with some other |
698 | bbs. */ | |
699 | ||
526ceb68 TS |
700 | static strinfo * |
701 | unshare_strinfo (strinfo *si) | |
8b57bfeb | 702 | { |
526ceb68 | 703 | strinfo *nsi; |
8b57bfeb JJ |
704 | |
705 | if (si->refcount == 1 && !strinfo_shared ()) | |
706 | return si; | |
707 | ||
e3f9a279 | 708 | nsi = new_strinfo (si->ptr, si->idx, si->nonzero_chars, si->full_string_p); |
8b57bfeb JJ |
709 | nsi->stmt = si->stmt; |
710 | nsi->endptr = si->endptr; | |
711 | nsi->first = si->first; | |
712 | nsi->prev = si->prev; | |
713 | nsi->next = si->next; | |
714 | nsi->writable = si->writable; | |
715 | set_strinfo (si->idx, nsi); | |
716 | free_strinfo (si); | |
717 | return nsi; | |
718 | } | |
719 | ||
204a913b JJ |
720 | /* Attempt to create a new strinfo for BASESI + OFF, or find existing |
721 | strinfo if there is any. Return it's idx, or 0 if no strinfo has | |
722 | been created. */ | |
723 | ||
724 | static int | |
e3f9a279 RS |
725 | get_stridx_plus_constant (strinfo *basesi, unsigned HOST_WIDE_INT off, |
726 | tree ptr) | |
204a913b | 727 | { |
5f3cd7c3 | 728 | if (TREE_CODE (ptr) == SSA_NAME && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ptr)) |
204a913b JJ |
729 | return 0; |
730 | ||
e3f9a279 RS |
731 | if (compare_nonzero_chars (basesi, off) < 0 |
732 | || !tree_fits_uhwi_p (basesi->nonzero_chars)) | |
204a913b JJ |
733 | return 0; |
734 | ||
e3f9a279 RS |
735 | unsigned HOST_WIDE_INT nonzero_chars |
736 | = tree_to_uhwi (basesi->nonzero_chars) - off; | |
526ceb68 | 737 | strinfo *si = basesi, *chainsi; |
204a913b JJ |
738 | if (si->first || si->prev || si->next) |
739 | si = verify_related_strinfos (basesi); | |
740 | if (si == NULL | |
e3f9a279 RS |
741 | || si->nonzero_chars == NULL_TREE |
742 | || TREE_CODE (si->nonzero_chars) != INTEGER_CST) | |
204a913b JJ |
743 | return 0; |
744 | ||
5f3cd7c3 JJ |
745 | if (TREE_CODE (ptr) == SSA_NAME |
746 | && ssa_ver_to_stridx.length () <= SSA_NAME_VERSION (ptr)) | |
204a913b JJ |
747 | ssa_ver_to_stridx.safe_grow_cleared (num_ssa_names); |
748 | ||
e3f9a279 | 749 | gcc_checking_assert (compare_tree_int (si->nonzero_chars, off) != -1); |
204a913b JJ |
750 | for (chainsi = si; chainsi->next; chainsi = si) |
751 | { | |
bde63fde | 752 | si = get_next_strinfo (chainsi); |
204a913b | 753 | if (si == NULL |
e3f9a279 RS |
754 | || si->nonzero_chars == NULL_TREE |
755 | || TREE_CODE (si->nonzero_chars) != INTEGER_CST) | |
204a913b | 756 | break; |
e3f9a279 | 757 | int r = compare_tree_int (si->nonzero_chars, nonzero_chars); |
204a913b JJ |
758 | if (r != 1) |
759 | { | |
760 | if (r == 0) | |
761 | { | |
55a0f21a JJ |
762 | if (TREE_CODE (ptr) == SSA_NAME) |
763 | ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)] = si->idx; | |
764 | else | |
765 | { | |
766 | int *pidx = addr_stridxptr (TREE_OPERAND (ptr, 0)); | |
767 | if (pidx != NULL && *pidx == 0) | |
768 | *pidx = si->idx; | |
769 | } | |
204a913b JJ |
770 | return si->idx; |
771 | } | |
772 | break; | |
773 | } | |
774 | } | |
775 | ||
776 | int idx = new_stridx (ptr); | |
777 | if (idx == 0) | |
778 | return 0; | |
e3f9a279 RS |
779 | si = new_strinfo (ptr, idx, build_int_cst (size_type_node, nonzero_chars), |
780 | basesi->full_string_p); | |
204a913b | 781 | set_strinfo (idx, si); |
9c8c7338 | 782 | if (strinfo *nextsi = get_strinfo (chainsi->next)) |
204a913b | 783 | { |
9c8c7338 | 784 | nextsi = unshare_strinfo (nextsi); |
204a913b JJ |
785 | si->next = nextsi->idx; |
786 | nextsi->prev = idx; | |
787 | } | |
788 | chainsi = unshare_strinfo (chainsi); | |
789 | if (chainsi->first == 0) | |
790 | chainsi->first = chainsi->idx; | |
791 | chainsi->next = idx; | |
e3f9a279 | 792 | if (chainsi->endptr == NULL_TREE && zero_length_string_p (si)) |
204a913b JJ |
793 | chainsi->endptr = ptr; |
794 | si->endptr = chainsi->endptr; | |
795 | si->prev = chainsi->idx; | |
796 | si->first = chainsi->first; | |
797 | si->writable = chainsi->writable; | |
798 | return si->idx; | |
799 | } | |
800 | ||
8b57bfeb JJ |
801 | /* Note that PTR, a pointer SSA_NAME initialized in the current stmt, points |
802 | to a zero-length string and if possible chain it to a related strinfo | |
803 | chain whose part is or might be CHAINSI. */ | |
804 | ||
526ceb68 TS |
805 | static strinfo * |
806 | zero_length_string (tree ptr, strinfo *chainsi) | |
8b57bfeb | 807 | { |
526ceb68 | 808 | strinfo *si; |
8b57bfeb | 809 | int idx; |
204a913b JJ |
810 | if (ssa_ver_to_stridx.length () <= SSA_NAME_VERSION (ptr)) |
811 | ssa_ver_to_stridx.safe_grow_cleared (num_ssa_names); | |
8b57bfeb | 812 | gcc_checking_assert (TREE_CODE (ptr) == SSA_NAME |
204a913b | 813 | && ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)] == 0); |
8b57bfeb JJ |
814 | |
815 | if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ptr)) | |
816 | return NULL; | |
817 | if (chainsi != NULL) | |
818 | { | |
819 | si = verify_related_strinfos (chainsi); | |
820 | if (si) | |
821 | { | |
bde63fde | 822 | do |
8b57bfeb | 823 | { |
862088aa | 824 | /* We shouldn't mix delayed and non-delayed lengths. */ |
e3f9a279 | 825 | gcc_assert (si->full_string_p); |
bde63fde | 826 | if (si->endptr == NULL_TREE) |
8b57bfeb | 827 | { |
bde63fde RS |
828 | si = unshare_strinfo (si); |
829 | si->endptr = ptr; | |
8b57bfeb | 830 | } |
bde63fde RS |
831 | chainsi = si; |
832 | si = get_next_strinfo (si); | |
8b57bfeb | 833 | } |
bde63fde | 834 | while (si != NULL); |
e3f9a279 | 835 | if (zero_length_string_p (chainsi)) |
8b57bfeb JJ |
836 | { |
837 | if (chainsi->next) | |
838 | { | |
839 | chainsi = unshare_strinfo (chainsi); | |
840 | chainsi->next = 0; | |
841 | } | |
9771b263 | 842 | ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)] = chainsi->idx; |
8b57bfeb JJ |
843 | return chainsi; |
844 | } | |
845 | } | |
862088aa | 846 | else |
8b57bfeb | 847 | { |
862088aa | 848 | /* We shouldn't mix delayed and non-delayed lengths. */ |
e3f9a279 | 849 | gcc_assert (chainsi->full_string_p); |
862088aa RS |
850 | if (chainsi->first || chainsi->prev || chainsi->next) |
851 | { | |
852 | chainsi = unshare_strinfo (chainsi); | |
853 | chainsi->first = 0; | |
854 | chainsi->prev = 0; | |
855 | chainsi->next = 0; | |
856 | } | |
8b57bfeb JJ |
857 | } |
858 | } | |
859 | idx = new_stridx (ptr); | |
860 | if (idx == 0) | |
861 | return NULL; | |
e3f9a279 | 862 | si = new_strinfo (ptr, idx, build_int_cst (size_type_node, 0), true); |
8b57bfeb JJ |
863 | set_strinfo (idx, si); |
864 | si->endptr = ptr; | |
865 | if (chainsi != NULL) | |
866 | { | |
867 | chainsi = unshare_strinfo (chainsi); | |
868 | if (chainsi->first == 0) | |
869 | chainsi->first = chainsi->idx; | |
870 | chainsi->next = idx; | |
93a90db6 AK |
871 | if (chainsi->endptr == NULL_TREE) |
872 | chainsi->endptr = ptr; | |
8b57bfeb JJ |
873 | si->prev = chainsi->idx; |
874 | si->first = chainsi->first; | |
875 | si->writable = chainsi->writable; | |
876 | } | |
877 | return si; | |
878 | } | |
879 | ||
e3f9a279 RS |
880 | /* For strinfo ORIGSI whose length has been just updated, adjust other |
881 | related strinfos so that they match the new ORIGSI. This involves: | |
882 | ||
883 | - adding ADJ to the nonzero_chars fields | |
884 | - copying full_string_p from the new ORIGSI. */ | |
8b57bfeb JJ |
885 | |
886 | static void | |
526ceb68 | 887 | adjust_related_strinfos (location_t loc, strinfo *origsi, tree adj) |
8b57bfeb | 888 | { |
526ceb68 | 889 | strinfo *si = verify_related_strinfos (origsi); |
8b57bfeb JJ |
890 | |
891 | if (si == NULL) | |
892 | return; | |
893 | ||
894 | while (1) | |
895 | { | |
526ceb68 | 896 | strinfo *nsi; |
8b57bfeb JJ |
897 | |
898 | if (si != origsi) | |
899 | { | |
900 | tree tem; | |
901 | ||
902 | si = unshare_strinfo (si); | |
862088aa RS |
903 | /* We shouldn't see delayed lengths here; the caller must have |
904 | calculated the old length in order to calculate the | |
905 | adjustment. */ | |
e3f9a279 RS |
906 | gcc_assert (si->nonzero_chars); |
907 | tem = fold_convert_loc (loc, TREE_TYPE (si->nonzero_chars), adj); | |
908 | si->nonzero_chars = fold_build2_loc (loc, PLUS_EXPR, | |
909 | TREE_TYPE (si->nonzero_chars), | |
910 | si->nonzero_chars, tem); | |
911 | si->full_string_p = origsi->full_string_p; | |
93a90db6 | 912 | |
8b57bfeb JJ |
913 | si->endptr = NULL_TREE; |
914 | si->dont_invalidate = true; | |
915 | } | |
bde63fde RS |
916 | nsi = get_next_strinfo (si); |
917 | if (nsi == NULL) | |
8b57bfeb JJ |
918 | return; |
919 | si = nsi; | |
920 | } | |
921 | } | |
922 | ||
923 | /* Find if there are other SSA_NAME pointers equal to PTR | |
924 | for which we don't track their string lengths yet. If so, use | |
925 | IDX for them. */ | |
926 | ||
927 | static void | |
928 | find_equal_ptrs (tree ptr, int idx) | |
929 | { | |
930 | if (TREE_CODE (ptr) != SSA_NAME) | |
931 | return; | |
932 | while (1) | |
933 | { | |
355fe088 | 934 | gimple *stmt = SSA_NAME_DEF_STMT (ptr); |
8b57bfeb JJ |
935 | if (!is_gimple_assign (stmt)) |
936 | return; | |
937 | ptr = gimple_assign_rhs1 (stmt); | |
938 | switch (gimple_assign_rhs_code (stmt)) | |
939 | { | |
940 | case SSA_NAME: | |
941 | break; | |
97246d78 JJ |
942 | CASE_CONVERT: |
943 | if (!POINTER_TYPE_P (TREE_TYPE (ptr))) | |
944 | return; | |
945 | if (TREE_CODE (ptr) == SSA_NAME) | |
946 | break; | |
947 | if (TREE_CODE (ptr) != ADDR_EXPR) | |
948 | return; | |
949 | /* FALLTHRU */ | |
8b57bfeb JJ |
950 | case ADDR_EXPR: |
951 | { | |
952 | int *pidx = addr_stridxptr (TREE_OPERAND (ptr, 0)); | |
953 | if (pidx != NULL && *pidx == 0) | |
954 | *pidx = idx; | |
955 | return; | |
956 | } | |
8b57bfeb JJ |
957 | default: |
958 | return; | |
959 | } | |
960 | ||
961 | /* We might find an endptr created in this pass. Grow the | |
962 | vector in that case. */ | |
9771b263 DN |
963 | if (ssa_ver_to_stridx.length () <= SSA_NAME_VERSION (ptr)) |
964 | ssa_ver_to_stridx.safe_grow_cleared (num_ssa_names); | |
8b57bfeb | 965 | |
9771b263 | 966 | if (ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)] != 0) |
8b57bfeb | 967 | return; |
9771b263 | 968 | ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)] = idx; |
8b57bfeb JJ |
969 | } |
970 | } | |
971 | ||
0ad84f34 JJ |
972 | /* Return true if STMT is a call to a builtin function with the right |
973 | arguments and attributes that should be considered for optimization | |
974 | by this pass. */ | |
975 | ||
976 | static bool | |
977 | valid_builtin_call (gimple *stmt) | |
978 | { | |
979 | if (!gimple_call_builtin_p (stmt, BUILT_IN_NORMAL)) | |
980 | return false; | |
981 | ||
982 | tree callee = gimple_call_fndecl (stmt); | |
983 | switch (DECL_FUNCTION_CODE (callee)) | |
984 | { | |
985 | case BUILT_IN_MEMCMP: | |
986 | case BUILT_IN_MEMCMP_EQ: | |
987 | case BUILT_IN_STRCHR: | |
0ad84f34 | 988 | case BUILT_IN_STRLEN: |
0ad84f34 JJ |
989 | /* The above functions should be pure. Punt if they aren't. */ |
990 | if (gimple_vdef (stmt) || gimple_vuse (stmt) == NULL_TREE) | |
991 | return false; | |
992 | break; | |
993 | ||
994 | case BUILT_IN_CALLOC: | |
995 | case BUILT_IN_MALLOC: | |
996 | case BUILT_IN_MEMCPY: | |
997 | case BUILT_IN_MEMCPY_CHK: | |
0ad84f34 JJ |
998 | case BUILT_IN_MEMPCPY: |
999 | case BUILT_IN_MEMPCPY_CHK: | |
0ad84f34 JJ |
1000 | case BUILT_IN_MEMSET: |
1001 | case BUILT_IN_STPCPY: | |
1002 | case BUILT_IN_STPCPY_CHK: | |
0ad84f34 JJ |
1003 | case BUILT_IN_STRCAT: |
1004 | case BUILT_IN_STRCAT_CHK: | |
0ad84f34 JJ |
1005 | case BUILT_IN_STRCPY: |
1006 | case BUILT_IN_STRCPY_CHK: | |
0ad84f34 JJ |
1007 | /* The above functions should be neither const nor pure. Punt if they |
1008 | aren't. */ | |
1009 | if (gimple_vdef (stmt) == NULL_TREE || gimple_vuse (stmt) == NULL_TREE) | |
1010 | return false; | |
1011 | break; | |
1012 | ||
1013 | default: | |
1014 | break; | |
1015 | } | |
1016 | ||
1017 | return true; | |
1018 | } | |
1019 | ||
8b57bfeb JJ |
1020 | /* If the last .MEM setter statement before STMT is |
1021 | memcpy (x, y, strlen (y) + 1), the only .MEM use of it is STMT | |
1022 | and STMT is known to overwrite x[strlen (x)], adjust the last memcpy to | |
1023 | just memcpy (x, y, strlen (y)). SI must be the zero length | |
1024 | strinfo. */ | |
1025 | ||
1026 | static void | |
526ceb68 | 1027 | adjust_last_stmt (strinfo *si, gimple *stmt, bool is_strcat) |
8b57bfeb JJ |
1028 | { |
1029 | tree vuse, callee, len; | |
1030 | struct laststmt_struct last = laststmt; | |
526ceb68 | 1031 | strinfo *lastsi, *firstsi; |
f5fc4a04 | 1032 | unsigned len_arg_no = 2; |
8b57bfeb JJ |
1033 | |
1034 | laststmt.stmt = NULL; | |
1035 | laststmt.len = NULL_TREE; | |
1036 | laststmt.stridx = 0; | |
1037 | ||
1038 | if (last.stmt == NULL) | |
1039 | return; | |
1040 | ||
1041 | vuse = gimple_vuse (stmt); | |
1042 | if (vuse == NULL_TREE | |
1043 | || SSA_NAME_DEF_STMT (vuse) != last.stmt | |
1044 | || !has_single_use (vuse)) | |
1045 | return; | |
1046 | ||
1047 | gcc_assert (last.stridx > 0); | |
1048 | lastsi = get_strinfo (last.stridx); | |
1049 | if (lastsi == NULL) | |
1050 | return; | |
1051 | ||
1052 | if (lastsi != si) | |
1053 | { | |
1054 | if (lastsi->first == 0 || lastsi->first != si->first) | |
1055 | return; | |
1056 | ||
1057 | firstsi = verify_related_strinfos (si); | |
1058 | if (firstsi == NULL) | |
1059 | return; | |
1060 | while (firstsi != lastsi) | |
1061 | { | |
bde63fde RS |
1062 | firstsi = get_next_strinfo (firstsi); |
1063 | if (firstsi == NULL) | |
8b57bfeb | 1064 | return; |
8b57bfeb JJ |
1065 | } |
1066 | } | |
1067 | ||
e3f9a279 RS |
1068 | if (!is_strcat && !zero_length_string_p (si)) |
1069 | return; | |
8b57bfeb JJ |
1070 | |
1071 | if (is_gimple_assign (last.stmt)) | |
1072 | { | |
1073 | gimple_stmt_iterator gsi; | |
1074 | ||
1075 | if (!integer_zerop (gimple_assign_rhs1 (last.stmt))) | |
1076 | return; | |
1077 | if (stmt_could_throw_p (last.stmt)) | |
1078 | return; | |
1079 | gsi = gsi_for_stmt (last.stmt); | |
1080 | unlink_stmt_vdef (last.stmt); | |
1081 | release_defs (last.stmt); | |
1082 | gsi_remove (&gsi, true); | |
1083 | return; | |
1084 | } | |
1085 | ||
0ad84f34 | 1086 | if (!valid_builtin_call (last.stmt)) |
8b57bfeb JJ |
1087 | return; |
1088 | ||
3626621a | 1089 | callee = gimple_call_fndecl (last.stmt); |
8b57bfeb JJ |
1090 | switch (DECL_FUNCTION_CODE (callee)) |
1091 | { | |
1092 | case BUILT_IN_MEMCPY: | |
1093 | case BUILT_IN_MEMCPY_CHK: | |
1094 | break; | |
1095 | default: | |
1096 | return; | |
1097 | } | |
1098 | ||
f5fc4a04 | 1099 | len = gimple_call_arg (last.stmt, len_arg_no); |
cc269bb6 | 1100 | if (tree_fits_uhwi_p (len)) |
8b57bfeb | 1101 | { |
cc269bb6 | 1102 | if (!tree_fits_uhwi_p (last.len) |
8b57bfeb | 1103 | || integer_zerop (len) |
7d362f6c | 1104 | || tree_to_uhwi (len) != tree_to_uhwi (last.len) + 1) |
8b57bfeb JJ |
1105 | return; |
1106 | /* Don't adjust the length if it is divisible by 4, it is more efficient | |
1107 | to store the extra '\0' in that case. */ | |
7d362f6c | 1108 | if ((tree_to_uhwi (len) & 3) == 0) |
8b57bfeb JJ |
1109 | return; |
1110 | } | |
1111 | else if (TREE_CODE (len) == SSA_NAME) | |
1112 | { | |
355fe088 | 1113 | gimple *def_stmt = SSA_NAME_DEF_STMT (len); |
8b57bfeb JJ |
1114 | if (!is_gimple_assign (def_stmt) |
1115 | || gimple_assign_rhs_code (def_stmt) != PLUS_EXPR | |
1116 | || gimple_assign_rhs1 (def_stmt) != last.len | |
1117 | || !integer_onep (gimple_assign_rhs2 (def_stmt))) | |
1118 | return; | |
1119 | } | |
1120 | else | |
1121 | return; | |
1122 | ||
f5fc4a04 | 1123 | gimple_call_set_arg (last.stmt, len_arg_no, last.len); |
8b57bfeb JJ |
1124 | update_stmt (last.stmt); |
1125 | } | |
1126 | ||
a7bf6c08 MS |
1127 | /* For an LHS that is an SSA_NAME with integer type and for strlen() |
1128 | argument SRC, set LHS range info to [0, N] if SRC refers to | |
1129 | a character array A[N] with unknown length bounded by N. */ | |
06199618 MS |
1130 | |
1131 | static void | |
1132 | maybe_set_strlen_range (tree lhs, tree src) | |
1133 | { | |
a7bf6c08 MS |
1134 | if (TREE_CODE (lhs) != SSA_NAME |
1135 | || !INTEGRAL_TYPE_P (TREE_TYPE (lhs))) | |
06199618 MS |
1136 | return; |
1137 | ||
1138 | if (TREE_CODE (src) == SSA_NAME) | |
1139 | { | |
1140 | gimple *def = SSA_NAME_DEF_STMT (src); | |
1141 | if (is_gimple_assign (def) | |
1142 | && gimple_assign_rhs_code (def) == ADDR_EXPR) | |
1143 | src = gimple_assign_rhs1 (def); | |
1144 | } | |
1145 | ||
1146 | if (TREE_CODE (src) != ADDR_EXPR) | |
1147 | return; | |
1148 | ||
1149 | /* The last array member of a struct can be bigger than its size | |
1150 | suggests if it's treated as a poor-man's flexible array member. */ | |
1151 | src = TREE_OPERAND (src, 0); | |
1152 | if (TREE_CODE (TREE_TYPE (src)) != ARRAY_TYPE | |
1153 | || array_at_struct_end_p (src)) | |
1154 | return; | |
1155 | ||
1156 | tree type = TREE_TYPE (src); | |
1157 | if (tree dom = TYPE_DOMAIN (type)) | |
1158 | if (tree maxval = TYPE_MAX_VALUE (dom)) | |
1159 | { | |
1160 | wide_int max = wi::to_wide (maxval); | |
1161 | wide_int min = wi::zero (max.get_precision ()); | |
1162 | set_range_info (lhs, VR_RANGE, min, max); | |
1163 | } | |
1164 | } | |
1165 | ||
8b57bfeb JJ |
1166 | /* Handle a strlen call. If strlen of the argument is known, replace |
1167 | the strlen call with the known value, otherwise remember that strlen | |
1168 | of the argument is stored in the lhs SSA_NAME. */ | |
1169 | ||
1170 | static void | |
1171 | handle_builtin_strlen (gimple_stmt_iterator *gsi) | |
1172 | { | |
1173 | int idx; | |
1174 | tree src; | |
355fe088 | 1175 | gimple *stmt = gsi_stmt (*gsi); |
8b57bfeb JJ |
1176 | tree lhs = gimple_call_lhs (stmt); |
1177 | ||
1178 | if (lhs == NULL_TREE) | |
1179 | return; | |
1180 | ||
1181 | src = gimple_call_arg (stmt, 0); | |
1182 | idx = get_stridx (src); | |
1183 | if (idx) | |
1184 | { | |
526ceb68 | 1185 | strinfo *si = NULL; |
8b57bfeb JJ |
1186 | tree rhs; |
1187 | ||
1188 | if (idx < 0) | |
1189 | rhs = build_int_cst (TREE_TYPE (lhs), ~idx); | |
1190 | else | |
1191 | { | |
1192 | rhs = NULL_TREE; | |
1193 | si = get_strinfo (idx); | |
1194 | if (si != NULL) | |
1195 | rhs = get_string_length (si); | |
1196 | } | |
1197 | if (rhs != NULL_TREE) | |
1198 | { | |
1199 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1200 | { | |
1201 | fprintf (dump_file, "Optimizing: "); | |
1202 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
1203 | } | |
1204 | rhs = unshare_expr (rhs); | |
1205 | if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs))) | |
1206 | rhs = fold_convert_loc (gimple_location (stmt), | |
1207 | TREE_TYPE (lhs), rhs); | |
1208 | if (!update_call_from_tree (gsi, rhs)) | |
1209 | gimplify_and_update_call_from_tree (gsi, rhs); | |
1210 | stmt = gsi_stmt (*gsi); | |
1211 | update_stmt (stmt); | |
1212 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1213 | { | |
1214 | fprintf (dump_file, "into: "); | |
1215 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
1216 | } | |
1217 | if (si != NULL | |
e3f9a279 RS |
1218 | && TREE_CODE (si->nonzero_chars) != SSA_NAME |
1219 | && TREE_CODE (si->nonzero_chars) != INTEGER_CST | |
8b57bfeb JJ |
1220 | && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) |
1221 | { | |
1222 | si = unshare_strinfo (si); | |
e3f9a279 RS |
1223 | si->nonzero_chars = lhs; |
1224 | gcc_assert (si->full_string_p); | |
8b57bfeb | 1225 | } |
025d57f0 | 1226 | |
6a33d0ff MS |
1227 | if (strlen_to_stridx) |
1228 | { | |
1229 | location_t loc = gimple_location (stmt); | |
1230 | strlen_to_stridx->put (lhs, stridx_strlenloc (idx, loc)); | |
1231 | } | |
8b57bfeb JJ |
1232 | return; |
1233 | } | |
1234 | } | |
1235 | if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) | |
1236 | return; | |
1237 | if (idx == 0) | |
1238 | idx = new_stridx (src); | |
e3f9a279 RS |
1239 | else |
1240 | { | |
1241 | strinfo *si = get_strinfo (idx); | |
1242 | if (si != NULL) | |
1243 | { | |
1244 | if (!si->full_string_p && !si->stmt) | |
1245 | { | |
1246 | /* Until now we only had a lower bound on the string length. | |
1247 | Install LHS as the actual length. */ | |
1248 | si = unshare_strinfo (si); | |
1aad7106 | 1249 | tree old = si->nonzero_chars; |
e3f9a279 RS |
1250 | si->nonzero_chars = lhs; |
1251 | si->full_string_p = true; | |
1aad7106 RS |
1252 | if (TREE_CODE (old) == INTEGER_CST) |
1253 | { | |
1254 | location_t loc = gimple_location (stmt); | |
1255 | old = fold_convert_loc (loc, TREE_TYPE (lhs), old); | |
1256 | tree adj = fold_build2_loc (loc, MINUS_EXPR, | |
1257 | TREE_TYPE (lhs), lhs, old); | |
1258 | adjust_related_strinfos (loc, si, adj); | |
1259 | } | |
1260 | else | |
1261 | { | |
1262 | si->first = 0; | |
1263 | si->prev = 0; | |
1264 | si->next = 0; | |
1265 | } | |
e3f9a279 RS |
1266 | } |
1267 | return; | |
1268 | } | |
1269 | } | |
8b57bfeb JJ |
1270 | if (idx) |
1271 | { | |
e3f9a279 | 1272 | strinfo *si = new_strinfo (src, idx, lhs, true); |
8b57bfeb JJ |
1273 | set_strinfo (idx, si); |
1274 | find_equal_ptrs (src, idx); | |
025d57f0 | 1275 | |
06199618 MS |
1276 | /* For SRC that is an array of N elements, set LHS's range |
1277 | to [0, N]. */ | |
1278 | maybe_set_strlen_range (lhs, src); | |
1279 | ||
6a33d0ff MS |
1280 | if (strlen_to_stridx) |
1281 | { | |
1282 | location_t loc = gimple_location (stmt); | |
1283 | strlen_to_stridx->put (lhs, stridx_strlenloc (idx, loc)); | |
1284 | } | |
8b57bfeb JJ |
1285 | } |
1286 | } | |
1287 | ||
1288 | /* Handle a strchr call. If strlen of the first argument is known, replace | |
1289 | the strchr (x, 0) call with the endptr or x + strlen, otherwise remember | |
1290 | that lhs of the call is endptr and strlen of the argument is endptr - x. */ | |
1291 | ||
1292 | static void | |
1293 | handle_builtin_strchr (gimple_stmt_iterator *gsi) | |
1294 | { | |
1295 | int idx; | |
1296 | tree src; | |
355fe088 | 1297 | gimple *stmt = gsi_stmt (*gsi); |
8b57bfeb JJ |
1298 | tree lhs = gimple_call_lhs (stmt); |
1299 | ||
1300 | if (lhs == NULL_TREE) | |
1301 | return; | |
1302 | ||
31db0fe0 | 1303 | if (!integer_zerop (gimple_call_arg (stmt, 1))) |
8b57bfeb JJ |
1304 | return; |
1305 | ||
1306 | src = gimple_call_arg (stmt, 0); | |
1307 | idx = get_stridx (src); | |
1308 | if (idx) | |
1309 | { | |
526ceb68 | 1310 | strinfo *si = NULL; |
8b57bfeb JJ |
1311 | tree rhs; |
1312 | ||
1313 | if (idx < 0) | |
1314 | rhs = build_int_cst (size_type_node, ~idx); | |
1315 | else | |
1316 | { | |
1317 | rhs = NULL_TREE; | |
1318 | si = get_strinfo (idx); | |
1319 | if (si != NULL) | |
1320 | rhs = get_string_length (si); | |
1321 | } | |
1322 | if (rhs != NULL_TREE) | |
1323 | { | |
1324 | location_t loc = gimple_location (stmt); | |
1325 | ||
1326 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1327 | { | |
1328 | fprintf (dump_file, "Optimizing: "); | |
1329 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
1330 | } | |
1331 | if (si != NULL && si->endptr != NULL_TREE) | |
1332 | { | |
1333 | rhs = unshare_expr (si->endptr); | |
1334 | if (!useless_type_conversion_p (TREE_TYPE (lhs), | |
1335 | TREE_TYPE (rhs))) | |
1336 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); | |
1337 | } | |
1338 | else | |
1339 | { | |
1340 | rhs = fold_convert_loc (loc, sizetype, unshare_expr (rhs)); | |
1341 | rhs = fold_build2_loc (loc, POINTER_PLUS_EXPR, | |
1342 | TREE_TYPE (src), src, rhs); | |
1343 | if (!useless_type_conversion_p (TREE_TYPE (lhs), | |
1344 | TREE_TYPE (rhs))) | |
1345 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); | |
1346 | } | |
1347 | if (!update_call_from_tree (gsi, rhs)) | |
1348 | gimplify_and_update_call_from_tree (gsi, rhs); | |
1349 | stmt = gsi_stmt (*gsi); | |
1350 | update_stmt (stmt); | |
1351 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1352 | { | |
1353 | fprintf (dump_file, "into: "); | |
1354 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
1355 | } | |
1356 | if (si != NULL | |
1357 | && si->endptr == NULL_TREE | |
1358 | && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) | |
1359 | { | |
1360 | si = unshare_strinfo (si); | |
1361 | si->endptr = lhs; | |
1362 | } | |
1363 | zero_length_string (lhs, si); | |
1364 | return; | |
1365 | } | |
1366 | } | |
1367 | if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) | |
1368 | return; | |
1369 | if (TREE_CODE (src) != SSA_NAME || !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (src)) | |
1370 | { | |
1371 | if (idx == 0) | |
1372 | idx = new_stridx (src); | |
1373 | else if (get_strinfo (idx) != NULL) | |
1374 | { | |
1375 | zero_length_string (lhs, NULL); | |
1376 | return; | |
1377 | } | |
1378 | if (idx) | |
1379 | { | |
1380 | location_t loc = gimple_location (stmt); | |
1381 | tree lhsu = fold_convert_loc (loc, size_type_node, lhs); | |
1382 | tree srcu = fold_convert_loc (loc, size_type_node, src); | |
1383 | tree length = fold_build2_loc (loc, MINUS_EXPR, | |
1384 | size_type_node, lhsu, srcu); | |
e3f9a279 | 1385 | strinfo *si = new_strinfo (src, idx, length, true); |
8b57bfeb JJ |
1386 | si->endptr = lhs; |
1387 | set_strinfo (idx, si); | |
1388 | find_equal_ptrs (src, idx); | |
1389 | zero_length_string (lhs, si); | |
1390 | } | |
1391 | } | |
1392 | else | |
1393 | zero_length_string (lhs, NULL); | |
1394 | } | |
1395 | ||
1396 | /* Handle a strcpy-like ({st{r,p}cpy,__st{r,p}cpy_chk}) call. | |
1397 | If strlen of the second argument is known, strlen of the first argument | |
1398 | is the same after this call. Furthermore, attempt to convert it to | |
1399 | memcpy. */ | |
1400 | ||
1401 | static void | |
1402 | handle_builtin_strcpy (enum built_in_function bcode, gimple_stmt_iterator *gsi) | |
1403 | { | |
1404 | int idx, didx; | |
cc8bea0a | 1405 | tree src, dst, srclen, len, lhs, type, fn, oldlen; |
8b57bfeb | 1406 | bool success; |
355fe088 | 1407 | gimple *stmt = gsi_stmt (*gsi); |
526ceb68 | 1408 | strinfo *si, *dsi, *olddsi, *zsi; |
8b57bfeb JJ |
1409 | location_t loc; |
1410 | ||
31db0fe0 | 1411 | src = gimple_call_arg (stmt, 1); |
8b57bfeb JJ |
1412 | dst = gimple_call_arg (stmt, 0); |
1413 | lhs = gimple_call_lhs (stmt); | |
1414 | idx = get_stridx (src); | |
1415 | si = NULL; | |
1416 | if (idx > 0) | |
1417 | si = get_strinfo (idx); | |
1418 | ||
1419 | didx = get_stridx (dst); | |
1420 | olddsi = NULL; | |
1421 | oldlen = NULL_TREE; | |
1422 | if (didx > 0) | |
1423 | olddsi = get_strinfo (didx); | |
1424 | else if (didx < 0) | |
1425 | return; | |
1426 | ||
1427 | if (olddsi != NULL) | |
1428 | adjust_last_stmt (olddsi, stmt, false); | |
1429 | ||
1430 | srclen = NULL_TREE; | |
1431 | if (si != NULL) | |
1432 | srclen = get_string_length (si); | |
1433 | else if (idx < 0) | |
1434 | srclen = build_int_cst (size_type_node, ~idx); | |
1435 | ||
1436 | loc = gimple_location (stmt); | |
1437 | if (srclen == NULL_TREE) | |
1438 | switch (bcode) | |
1439 | { | |
1440 | case BUILT_IN_STRCPY: | |
1441 | case BUILT_IN_STRCPY_CHK: | |
e79983f4 | 1442 | if (lhs != NULL_TREE || !builtin_decl_implicit_p (BUILT_IN_STPCPY)) |
8b57bfeb JJ |
1443 | return; |
1444 | break; | |
1445 | case BUILT_IN_STPCPY: | |
1446 | case BUILT_IN_STPCPY_CHK: | |
1447 | if (lhs == NULL_TREE) | |
1448 | return; | |
1449 | else | |
1450 | { | |
1451 | tree lhsuint = fold_convert_loc (loc, size_type_node, lhs); | |
1452 | srclen = fold_convert_loc (loc, size_type_node, dst); | |
1453 | srclen = fold_build2_loc (loc, MINUS_EXPR, size_type_node, | |
1454 | lhsuint, srclen); | |
1455 | } | |
1456 | break; | |
1457 | default: | |
1458 | gcc_unreachable (); | |
1459 | } | |
1460 | ||
1461 | if (didx == 0) | |
1462 | { | |
1463 | didx = new_stridx (dst); | |
1464 | if (didx == 0) | |
1465 | return; | |
1466 | } | |
1467 | if (olddsi != NULL) | |
1468 | { | |
e3f9a279 | 1469 | oldlen = olddsi->nonzero_chars; |
8b57bfeb | 1470 | dsi = unshare_strinfo (olddsi); |
e3f9a279 RS |
1471 | dsi->nonzero_chars = srclen; |
1472 | dsi->full_string_p = (srclen != NULL_TREE); | |
8b57bfeb JJ |
1473 | /* Break the chain, so adjust_related_strinfo on later pointers in |
1474 | the chain won't adjust this one anymore. */ | |
1475 | dsi->next = 0; | |
1476 | dsi->stmt = NULL; | |
1477 | dsi->endptr = NULL_TREE; | |
1478 | } | |
1479 | else | |
1480 | { | |
e3f9a279 | 1481 | dsi = new_strinfo (dst, didx, srclen, srclen != NULL_TREE); |
8b57bfeb JJ |
1482 | set_strinfo (didx, dsi); |
1483 | find_equal_ptrs (dst, didx); | |
1484 | } | |
1485 | dsi->writable = true; | |
1486 | dsi->dont_invalidate = true; | |
1487 | ||
e3f9a279 | 1488 | if (dsi->nonzero_chars == NULL_TREE) |
8b57bfeb | 1489 | { |
526ceb68 | 1490 | strinfo *chainsi; |
93a90db6 | 1491 | |
8b57bfeb JJ |
1492 | /* If string length of src is unknown, use delayed length |
1493 | computation. If string lenth of dst will be needed, it | |
1494 | can be computed by transforming this strcpy call into | |
1495 | stpcpy and subtracting dst from the return value. */ | |
93a90db6 AK |
1496 | |
1497 | /* Look for earlier strings whose length could be determined if | |
1498 | this strcpy is turned into an stpcpy. */ | |
1499 | ||
1500 | if (dsi->prev != 0 && (chainsi = verify_related_strinfos (dsi)) != NULL) | |
1501 | { | |
1502 | for (; chainsi && chainsi != dsi; chainsi = get_strinfo (chainsi->next)) | |
1503 | { | |
1504 | /* When setting a stmt for delayed length computation | |
1505 | prevent all strinfos through dsi from being | |
1506 | invalidated. */ | |
1507 | chainsi = unshare_strinfo (chainsi); | |
1508 | chainsi->stmt = stmt; | |
e3f9a279 RS |
1509 | chainsi->nonzero_chars = NULL_TREE; |
1510 | chainsi->full_string_p = false; | |
93a90db6 AK |
1511 | chainsi->endptr = NULL_TREE; |
1512 | chainsi->dont_invalidate = true; | |
1513 | } | |
1514 | } | |
8b57bfeb | 1515 | dsi->stmt = stmt; |
cc8bea0a MS |
1516 | |
1517 | /* Try to detect overlap before returning. This catches cases | |
1518 | like strcpy (d, d + n) where n is non-constant whose range | |
1519 | is such that (n <= strlen (d) holds). | |
1520 | ||
1521 | OLDDSI->NONZERO_chars may have been reset by this point with | |
1522 | oldlen holding it original value. */ | |
1523 | if (olddsi && oldlen) | |
1524 | { | |
1525 | /* Add 1 for the terminating NUL. */ | |
1526 | tree type = TREE_TYPE (oldlen); | |
1527 | oldlen = fold_build2 (PLUS_EXPR, type, oldlen, | |
1528 | build_int_cst (type, 1)); | |
1529 | check_bounds_or_overlap (as_a <gcall *>(stmt), olddsi->ptr, src, | |
1530 | oldlen, NULL_TREE); | |
1531 | } | |
1532 | ||
8b57bfeb JJ |
1533 | return; |
1534 | } | |
1535 | ||
1536 | if (olddsi != NULL) | |
1537 | { | |
1538 | tree adj = NULL_TREE; | |
1539 | if (oldlen == NULL_TREE) | |
1540 | ; | |
1541 | else if (integer_zerop (oldlen)) | |
1542 | adj = srclen; | |
1543 | else if (TREE_CODE (oldlen) == INTEGER_CST | |
1544 | || TREE_CODE (srclen) == INTEGER_CST) | |
1545 | adj = fold_build2_loc (loc, MINUS_EXPR, | |
1546 | TREE_TYPE (srclen), srclen, | |
1547 | fold_convert_loc (loc, TREE_TYPE (srclen), | |
1548 | oldlen)); | |
1549 | if (adj != NULL_TREE) | |
1550 | adjust_related_strinfos (loc, dsi, adj); | |
1551 | else | |
1552 | dsi->prev = 0; | |
1553 | } | |
1554 | /* strcpy src may not overlap dst, so src doesn't need to be | |
1555 | invalidated either. */ | |
1556 | if (si != NULL) | |
1557 | si->dont_invalidate = true; | |
1558 | ||
1559 | fn = NULL_TREE; | |
1560 | zsi = NULL; | |
1561 | switch (bcode) | |
1562 | { | |
1563 | case BUILT_IN_STRCPY: | |
e79983f4 | 1564 | fn = builtin_decl_implicit (BUILT_IN_MEMCPY); |
8b57bfeb | 1565 | if (lhs) |
9771b263 | 1566 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] = didx; |
8b57bfeb JJ |
1567 | break; |
1568 | case BUILT_IN_STRCPY_CHK: | |
e79983f4 | 1569 | fn = builtin_decl_explicit (BUILT_IN_MEMCPY_CHK); |
8b57bfeb | 1570 | if (lhs) |
9771b263 | 1571 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] = didx; |
8b57bfeb JJ |
1572 | break; |
1573 | case BUILT_IN_STPCPY: | |
1574 | /* This would need adjustment of the lhs (subtract one), | |
1575 | or detection that the trailing '\0' doesn't need to be | |
1576 | written, if it will be immediately overwritten. | |
e79983f4 | 1577 | fn = builtin_decl_explicit (BUILT_IN_MEMPCPY); */ |
8b57bfeb JJ |
1578 | if (lhs) |
1579 | { | |
1580 | dsi->endptr = lhs; | |
1581 | zsi = zero_length_string (lhs, dsi); | |
1582 | } | |
1583 | break; | |
1584 | case BUILT_IN_STPCPY_CHK: | |
1585 | /* This would need adjustment of the lhs (subtract one), | |
1586 | or detection that the trailing '\0' doesn't need to be | |
1587 | written, if it will be immediately overwritten. | |
e79983f4 | 1588 | fn = builtin_decl_explicit (BUILT_IN_MEMPCPY_CHK); */ |
8b57bfeb JJ |
1589 | if (lhs) |
1590 | { | |
1591 | dsi->endptr = lhs; | |
1592 | zsi = zero_length_string (lhs, dsi); | |
1593 | } | |
1594 | break; | |
1595 | default: | |
1596 | gcc_unreachable (); | |
1597 | } | |
1598 | if (zsi != NULL) | |
1599 | zsi->dont_invalidate = true; | |
1600 | ||
cc8bea0a MS |
1601 | if (fn) |
1602 | { | |
1603 | tree args = TYPE_ARG_TYPES (TREE_TYPE (fn)); | |
1604 | type = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (args))); | |
1605 | } | |
1606 | else | |
1607 | type = size_type_node; | |
8b57bfeb JJ |
1608 | |
1609 | len = fold_convert_loc (loc, type, unshare_expr (srclen)); | |
1610 | len = fold_build2_loc (loc, PLUS_EXPR, type, len, build_int_cst (type, 1)); | |
cc8bea0a MS |
1611 | |
1612 | /* Set the no-warning bit on the transformed statement? */ | |
1613 | bool set_no_warning = false; | |
1614 | ||
1615 | if (const strinfo *chksi = olddsi ? olddsi : dsi) | |
1616 | if (si | |
1617 | && !check_bounds_or_overlap (as_a <gcall *>(stmt), chksi->ptr, si->ptr, | |
1618 | NULL_TREE, len)) | |
1619 | { | |
1620 | gimple_set_no_warning (stmt, true); | |
1621 | set_no_warning = true; | |
1622 | } | |
1623 | ||
1624 | if (fn == NULL_TREE) | |
1625 | return; | |
1626 | ||
8b57bfeb JJ |
1627 | len = force_gimple_operand_gsi (gsi, len, true, NULL_TREE, true, |
1628 | GSI_SAME_STMT); | |
1629 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1630 | { | |
1631 | fprintf (dump_file, "Optimizing: "); | |
1632 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
1633 | } | |
31db0fe0 ML |
1634 | if (gimple_call_num_args (stmt) == 2) |
1635 | success = update_gimple_call (gsi, fn, 3, dst, src, len); | |
8b57bfeb | 1636 | else |
31db0fe0 ML |
1637 | success = update_gimple_call (gsi, fn, 4, dst, src, len, |
1638 | gimple_call_arg (stmt, 2)); | |
8b57bfeb JJ |
1639 | if (success) |
1640 | { | |
1641 | stmt = gsi_stmt (*gsi); | |
1642 | update_stmt (stmt); | |
1643 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1644 | { | |
1645 | fprintf (dump_file, "into: "); | |
1646 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
1647 | } | |
1648 | /* Allow adjust_last_stmt to decrease this memcpy's size. */ | |
1649 | laststmt.stmt = stmt; | |
1650 | laststmt.len = srclen; | |
1651 | laststmt.stridx = dsi->idx; | |
1652 | } | |
1653 | else if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1654 | fprintf (dump_file, "not possible.\n"); | |
cc8bea0a MS |
1655 | |
1656 | if (set_no_warning) | |
1657 | gimple_set_no_warning (stmt, true); | |
1658 | } | |
1659 | ||
1660 | /* Check the size argument to the built-in forms of stpncpy and strncpy | |
1661 | for out-of-bounds offsets or overlapping access, and to see if the | |
1662 | size argument is derived from a call to strlen() on the source argument, | |
1663 | and if so, issue an appropriate warning. */ | |
1664 | ||
1665 | static void | |
1666 | handle_builtin_strncat (built_in_function bcode, gimple_stmt_iterator *gsi) | |
1667 | { | |
1668 | /* Same as stxncpy(). */ | |
1669 | handle_builtin_stxncpy (bcode, gsi); | |
8b57bfeb JJ |
1670 | } |
1671 | ||
025d57f0 MS |
1672 | /* Return true if LEN depends on a call to strlen(SRC) in an interesting |
1673 | way. LEN can either be an integer expression, or a pointer (to char). | |
1674 | When it is the latter (such as in recursive calls to self) is is | |
1675 | assumed to be the argument in some call to strlen() whose relationship | |
1676 | to SRC is being ascertained. */ | |
1677 | ||
1678 | static bool | |
1679 | is_strlen_related_p (tree src, tree len) | |
1680 | { | |
1681 | if (TREE_CODE (TREE_TYPE (len)) == POINTER_TYPE | |
1682 | && operand_equal_p (src, len, 0)) | |
1683 | return true; | |
1684 | ||
1685 | if (TREE_CODE (len) != SSA_NAME) | |
1686 | return false; | |
1687 | ||
1688 | gimple *def_stmt = SSA_NAME_DEF_STMT (len); | |
1689 | if (!def_stmt) | |
1690 | return false; | |
1691 | ||
1692 | if (is_gimple_call (def_stmt)) | |
1693 | { | |
1694 | tree func = gimple_call_fndecl (def_stmt); | |
1695 | if (!valid_builtin_call (def_stmt) | |
1696 | || DECL_FUNCTION_CODE (func) != BUILT_IN_STRLEN) | |
1697 | return false; | |
1698 | ||
1699 | tree arg = gimple_call_arg (def_stmt, 0); | |
1700 | return is_strlen_related_p (src, arg); | |
1701 | } | |
1702 | ||
1703 | if (!is_gimple_assign (def_stmt)) | |
1704 | return false; | |
1705 | ||
1706 | tree_code code = gimple_assign_rhs_code (def_stmt); | |
1707 | tree rhs1 = gimple_assign_rhs1 (def_stmt); | |
1708 | tree rhstype = TREE_TYPE (rhs1); | |
1709 | ||
1710 | if ((TREE_CODE (rhstype) == POINTER_TYPE && code == POINTER_PLUS_EXPR) | |
1711 | || (INTEGRAL_TYPE_P (rhstype) | |
1712 | && (code == BIT_AND_EXPR | |
1713 | || code == NOP_EXPR))) | |
1714 | { | |
1715 | /* Pointer plus (an integer) and integer cast or truncation are | |
1716 | considered among the (potentially) related expressions to strlen. | |
1717 | Others are not. */ | |
1718 | return is_strlen_related_p (src, rhs1); | |
1719 | } | |
1720 | ||
1721 | return false; | |
1722 | } | |
1723 | ||
5d0d5d68 MS |
1724 | /* Called by handle_builtin_stxncpy and by gimple_fold_builtin_strncpy |
1725 | in gimple-fold.c. | |
1726 | Check to see if the specified bound is a) equal to the size of | |
1727 | the destination DST and if so, b) if it's immediately followed by | |
1728 | DST[CNT - 1] = '\0'. If a) holds and b) does not, warn. Otherwise, | |
1729 | do nothing. Return true if diagnostic has been issued. | |
025d57f0 MS |
1730 | |
1731 | The purpose is to diagnose calls to strncpy and stpncpy that do | |
1732 | not nul-terminate the copy while allowing for the idiom where | |
1733 | such a call is immediately followed by setting the last element | |
1734 | to nul, as in: | |
1735 | char a[32]; | |
1736 | strncpy (a, s, sizeof a); | |
1737 | a[sizeof a - 1] = '\0'; | |
1738 | */ | |
1739 | ||
5d0d5d68 | 1740 | bool |
025d57f0 MS |
1741 | maybe_diag_stxncpy_trunc (gimple_stmt_iterator gsi, tree src, tree cnt) |
1742 | { | |
025d57f0 | 1743 | gimple *stmt = gsi_stmt (gsi); |
e9b9fa4c MS |
1744 | if (gimple_no_warning_p (stmt)) |
1745 | return false; | |
025d57f0 MS |
1746 | |
1747 | wide_int cntrange[2]; | |
1748 | ||
1749 | if (TREE_CODE (cnt) == INTEGER_CST) | |
1750 | cntrange[0] = cntrange[1] = wi::to_wide (cnt); | |
1751 | else if (TREE_CODE (cnt) == SSA_NAME) | |
1752 | { | |
1753 | enum value_range_type rng = get_range_info (cnt, cntrange, cntrange + 1); | |
1754 | if (rng == VR_RANGE) | |
1755 | ; | |
1756 | else if (rng == VR_ANTI_RANGE) | |
1757 | { | |
1758 | wide_int maxobjsize = wi::to_wide (TYPE_MAX_VALUE (ptrdiff_type_node)); | |
1759 | ||
1760 | if (wi::ltu_p (cntrange[1], maxobjsize)) | |
1761 | { | |
1762 | cntrange[0] = cntrange[1] + 1; | |
1763 | cntrange[1] = maxobjsize; | |
1764 | } | |
1765 | else | |
1766 | { | |
1767 | cntrange[1] = cntrange[0] - 1; | |
1768 | cntrange[0] = wi::zero (TYPE_PRECISION (TREE_TYPE (cnt))); | |
1769 | } | |
1770 | } | |
1771 | else | |
1772 | return false; | |
1773 | } | |
1774 | else | |
1775 | return false; | |
1776 | ||
1777 | /* Negative value is the constant string length. If it's less than | |
5d0d5d68 MS |
1778 | the lower bound there is no truncation. Avoid calling get_stridx() |
1779 | when ssa_ver_to_stridx is empty. That implies the caller isn't | |
1780 | running under the control of this pass and ssa_ver_to_stridx hasn't | |
1781 | been created yet. */ | |
1782 | int sidx = ssa_ver_to_stridx.length () ? get_stridx (src) : 0; | |
025d57f0 MS |
1783 | if (sidx < 0 && wi::gtu_p (cntrange[0], ~sidx)) |
1784 | return false; | |
1785 | ||
1786 | tree dst = gimple_call_arg (stmt, 0); | |
025d57f0 MS |
1787 | tree dstdecl = dst; |
1788 | if (TREE_CODE (dstdecl) == ADDR_EXPR) | |
1789 | dstdecl = TREE_OPERAND (dstdecl, 0); | |
1790 | ||
6a33d0ff MS |
1791 | /* If the destination refers to a an array/pointer declared nonstring |
1792 | return early. */ | |
1793 | tree ref = NULL_TREE; | |
1794 | if (get_attr_nonstring_decl (dstdecl, &ref)) | |
1795 | return false; | |
025d57f0 MS |
1796 | |
1797 | /* Look for dst[i] = '\0'; after the stxncpy() call and if found | |
1798 | avoid the truncation warning. */ | |
b25e5572 | 1799 | gsi_next_nondebug (&gsi); |
025d57f0 | 1800 | gimple *next_stmt = gsi_stmt (gsi); |
a76acaed MS |
1801 | if (!next_stmt) |
1802 | { | |
1803 | /* When there is no statement in the same basic block check | |
1804 | the immediate successor block. */ | |
1805 | if (basic_block bb = gimple_bb (stmt)) | |
1806 | { | |
1807 | if (single_succ_p (bb)) | |
1808 | { | |
1809 | /* For simplicity, ignore blocks with multiple outgoing | |
1810 | edges for now and only consider successor blocks along | |
1811 | normal edges. */ | |
1812 | edge e = EDGE_SUCC (bb, 0); | |
1813 | if (!(e->flags & EDGE_ABNORMAL)) | |
1814 | { | |
1815 | gsi = gsi_start_bb (e->dest); | |
1816 | next_stmt = gsi_stmt (gsi); | |
1817 | if (next_stmt && is_gimple_debug (next_stmt)) | |
1818 | { | |
1819 | gsi_next_nondebug (&gsi); | |
1820 | next_stmt = gsi_stmt (gsi); | |
1821 | } | |
1822 | } | |
1823 | } | |
1824 | } | |
1825 | } | |
025d57f0 | 1826 | |
a76acaed | 1827 | if (next_stmt && is_gimple_assign (next_stmt)) |
025d57f0 | 1828 | { |
025d57f0 | 1829 | tree lhs = gimple_assign_lhs (next_stmt); |
6a33d0ff MS |
1830 | tree_code code = TREE_CODE (lhs); |
1831 | if (code == ARRAY_REF || code == MEM_REF) | |
1832 | lhs = TREE_OPERAND (lhs, 0); | |
1833 | ||
1834 | tree func = gimple_call_fndecl (stmt); | |
1835 | if (DECL_FUNCTION_CODE (func) == BUILT_IN_STPNCPY) | |
1836 | { | |
1837 | tree ret = gimple_call_lhs (stmt); | |
1838 | if (ret && operand_equal_p (ret, lhs, 0)) | |
1839 | return false; | |
1840 | } | |
1841 | ||
1842 | /* Determine the base address and offset of the reference, | |
1843 | ignoring the innermost array index. */ | |
1844 | if (TREE_CODE (ref) == ARRAY_REF) | |
1845 | ref = TREE_OPERAND (ref, 0); | |
1846 | ||
a90c8804 | 1847 | poly_int64 dstoff; |
6a33d0ff MS |
1848 | tree dstbase = get_addr_base_and_unit_offset (ref, &dstoff); |
1849 | ||
a90c8804 | 1850 | poly_int64 lhsoff; |
6a33d0ff MS |
1851 | tree lhsbase = get_addr_base_and_unit_offset (lhs, &lhsoff); |
1852 | if (lhsbase | |
44e60df3 | 1853 | && dstbase |
a90c8804 | 1854 | && known_eq (dstoff, lhsoff) |
6a33d0ff | 1855 | && operand_equal_p (dstbase, lhsbase, 0)) |
025d57f0 MS |
1856 | return false; |
1857 | } | |
1858 | ||
1859 | int prec = TYPE_PRECISION (TREE_TYPE (cnt)); | |
1860 | wide_int lenrange[2]; | |
1861 | if (strinfo *sisrc = sidx > 0 ? get_strinfo (sidx) : NULL) | |
1862 | { | |
1863 | lenrange[0] = (sisrc->nonzero_chars | |
1864 | && TREE_CODE (sisrc->nonzero_chars) == INTEGER_CST | |
1865 | ? wi::to_wide (sisrc->nonzero_chars) | |
1866 | : wi::zero (prec)); | |
1867 | lenrange[1] = lenrange[0]; | |
1868 | } | |
1869 | else if (sidx < 0) | |
1870 | lenrange[0] = lenrange[1] = wi::shwi (~sidx, prec); | |
1871 | else | |
1872 | { | |
1873 | tree range[2]; | |
1874 | get_range_strlen (src, range); | |
c6ba596b MP |
1875 | if (range[0] != NULL_TREE |
1876 | && TREE_CODE (range[0]) == INTEGER_CST | |
1877 | && range[1] != NULL_TREE | |
1878 | && TREE_CODE (range[1]) == INTEGER_CST) | |
025d57f0 MS |
1879 | { |
1880 | lenrange[0] = wi::to_wide (range[0], prec); | |
1881 | lenrange[1] = wi::to_wide (range[1], prec); | |
1882 | } | |
1883 | else | |
1884 | { | |
1885 | lenrange[0] = wi::shwi (0, prec); | |
1886 | lenrange[1] = wi::shwi (-1, prec); | |
1887 | } | |
1888 | } | |
1889 | ||
e3329a78 MS |
1890 | location_t callloc = gimple_nonartificial_location (stmt); |
1891 | callloc = expansion_point_location_if_in_system_header (callloc); | |
1892 | ||
025d57f0 MS |
1893 | tree func = gimple_call_fndecl (stmt); |
1894 | ||
1895 | if (lenrange[0] != 0 || !wi::neg_p (lenrange[1])) | |
1896 | { | |
1897 | /* If the longest source string is shorter than the lower bound | |
1898 | of the specified count the copy is definitely nul-terminated. */ | |
1899 | if (wi::ltu_p (lenrange[1], cntrange[0])) | |
1900 | return false; | |
1901 | ||
1902 | if (wi::neg_p (lenrange[1])) | |
1903 | { | |
1904 | /* The length of one of the strings is unknown but at least | |
1905 | one has non-zero length and that length is stored in | |
1906 | LENRANGE[1]. Swap the bounds to force a "may be truncated" | |
1907 | warning below. */ | |
1908 | lenrange[1] = lenrange[0]; | |
1909 | lenrange[0] = wi::shwi (0, prec); | |
1910 | } | |
1911 | ||
5d0d5d68 MS |
1912 | gcall *call = as_a <gcall *> (stmt); |
1913 | ||
1914 | if (lenrange[0] == cntrange[1] && cntrange[0] == cntrange[1]) | |
1c89478a MS |
1915 | return warning_n (callloc, OPT_Wstringop_truncation, |
1916 | cntrange[0].to_uhwi (), | |
1917 | "%G%qD output truncated before terminating " | |
1918 | "nul copying %E byte from a string of the " | |
1919 | "same length", | |
1920 | "%G%qD output truncated before terminating nul " | |
1921 | "copying %E bytes from a string of the same " | |
1922 | "length", | |
1923 | call, func, cnt); | |
5d0d5d68 | 1924 | else if (wi::geu_p (lenrange[0], cntrange[1])) |
025d57f0 MS |
1925 | { |
1926 | /* The shortest string is longer than the upper bound of | |
1927 | the count so the truncation is certain. */ | |
1928 | if (cntrange[0] == cntrange[1]) | |
1c89478a MS |
1929 | return warning_n (callloc, OPT_Wstringop_truncation, |
1930 | cntrange[0].to_uhwi (), | |
1931 | "%G%qD output truncated copying %E byte " | |
1932 | "from a string of length %wu", | |
1933 | "%G%qD output truncated copying %E bytes " | |
1934 | "from a string of length %wu", | |
1935 | call, func, cnt, lenrange[0].to_uhwi ()); | |
025d57f0 MS |
1936 | |
1937 | return warning_at (callloc, OPT_Wstringop_truncation, | |
5d0d5d68 | 1938 | "%G%qD output truncated copying between %wu " |
025d57f0 | 1939 | "and %wu bytes from a string of length %wu", |
5d0d5d68 | 1940 | call, func, cntrange[0].to_uhwi (), |
025d57f0 MS |
1941 | cntrange[1].to_uhwi (), lenrange[0].to_uhwi ()); |
1942 | } | |
1943 | else if (wi::geu_p (lenrange[1], cntrange[1])) | |
1944 | { | |
1945 | /* The longest string is longer than the upper bound of | |
1946 | the count so the truncation is possible. */ | |
1947 | if (cntrange[0] == cntrange[1]) | |
1c89478a MS |
1948 | return warning_n (callloc, OPT_Wstringop_truncation, |
1949 | cntrange[0].to_uhwi (), | |
1950 | "%G%qD output may be truncated copying %E " | |
1951 | "byte from a string of length %wu", | |
1952 | "%G%qD output may be truncated copying %E " | |
1953 | "bytes from a string of length %wu", | |
1954 | call, func, cnt, lenrange[1].to_uhwi ()); | |
025d57f0 MS |
1955 | |
1956 | return warning_at (callloc, OPT_Wstringop_truncation, | |
5d0d5d68 | 1957 | "%G%qD output may be truncated copying between %wu " |
025d57f0 | 1958 | "and %wu bytes from a string of length %wu", |
5d0d5d68 | 1959 | call, func, cntrange[0].to_uhwi (), |
025d57f0 MS |
1960 | cntrange[1].to_uhwi (), lenrange[1].to_uhwi ()); |
1961 | } | |
1962 | ||
1963 | if (cntrange[0] != cntrange[1] | |
1964 | && wi::leu_p (cntrange[0], lenrange[0]) | |
1965 | && wi::leu_p (cntrange[1], lenrange[0] + 1)) | |
1966 | { | |
1967 | /* If the source (including the terminating nul) is longer than | |
1968 | the lower bound of the specified count but shorter than the | |
1969 | upper bound the copy may (but need not) be truncated. */ | |
1970 | return warning_at (callloc, OPT_Wstringop_truncation, | |
5d0d5d68 MS |
1971 | "%G%qD output may be truncated copying between " |
1972 | "%wu and %wu bytes from a string of length %wu", | |
1973 | call, func, cntrange[0].to_uhwi (), | |
025d57f0 MS |
1974 | cntrange[1].to_uhwi (), lenrange[0].to_uhwi ()); |
1975 | } | |
1976 | } | |
1977 | ||
1978 | if (tree dstsize = compute_objsize (dst, 1)) | |
1979 | { | |
1980 | /* The source length is uknown. Try to determine the destination | |
1981 | size and see if it matches the specified bound. If not, bail. | |
1982 | Otherwise go on to see if it should be diagnosed for possible | |
1983 | truncation. */ | |
1984 | if (!dstsize) | |
1985 | return false; | |
1986 | ||
1987 | if (wi::to_wide (dstsize) != cntrange[1]) | |
1988 | return false; | |
1989 | ||
1990 | if (cntrange[0] == cntrange[1]) | |
1991 | return warning_at (callloc, OPT_Wstringop_truncation, | |
5d0d5d68 MS |
1992 | "%G%qD specified bound %E equals destination size", |
1993 | as_a <gcall *> (stmt), func, cnt); | |
025d57f0 MS |
1994 | } |
1995 | ||
1996 | return false; | |
1997 | } | |
1998 | ||
cc8bea0a MS |
1999 | /* Check the arguments to the built-in forms of stpncpy and strncpy for |
2000 | out-of-bounds offsets or overlapping access, and to see if the size | |
2001 | is derived from calling strlen() on the source argument, and if so, | |
2002 | issue the appropriate warning. */ | |
025d57f0 MS |
2003 | |
2004 | static void | |
2005 | handle_builtin_stxncpy (built_in_function, gimple_stmt_iterator *gsi) | |
2006 | { | |
6a33d0ff MS |
2007 | if (!strlen_to_stridx) |
2008 | return; | |
2009 | ||
025d57f0 MS |
2010 | gimple *stmt = gsi_stmt (*gsi); |
2011 | ||
31db0fe0 ML |
2012 | tree dst = gimple_call_arg (stmt, 0); |
2013 | tree src = gimple_call_arg (stmt, 1); | |
2014 | tree len = gimple_call_arg (stmt, 2); | |
cc8bea0a MS |
2015 | tree dstsize = NULL_TREE, srcsize = NULL_TREE; |
2016 | ||
2017 | int didx = get_stridx (dst); | |
2018 | if (strinfo *sidst = didx > 0 ? get_strinfo (didx) : NULL) | |
2019 | { | |
2020 | /* Compute the size of the destination string including the NUL. */ | |
2021 | if (sidst->nonzero_chars) | |
2022 | { | |
2023 | tree type = TREE_TYPE (sidst->nonzero_chars); | |
2024 | dstsize = fold_build2 (PLUS_EXPR, type, sidst->nonzero_chars, | |
2025 | build_int_cst (type, 1)); | |
2026 | } | |
2027 | dst = sidst->ptr; | |
2028 | } | |
2029 | ||
2030 | int sidx = get_stridx (src); | |
2031 | strinfo *sisrc = sidx > 0 ? get_strinfo (sidx) : NULL; | |
2032 | if (sisrc) | |
2033 | { | |
2034 | /* strncat() and strncpy() can modify the source string by writing | |
2035 | over the terminating nul so SISRC->DONT_INVALIDATE must be left | |
2036 | clear. */ | |
2037 | ||
2038 | /* Compute the size of the source string including the NUL. */ | |
2039 | if (sisrc->nonzero_chars) | |
2040 | { | |
2041 | tree type = TREE_TYPE (sisrc->nonzero_chars); | |
2042 | srcsize = fold_build2 (PLUS_EXPR, type, sisrc->nonzero_chars, | |
2043 | build_int_cst (type, 1)); | |
2044 | } | |
2045 | ||
2046 | src = sisrc->ptr; | |
2047 | } | |
2048 | else | |
2049 | srcsize = NULL_TREE; | |
2050 | ||
2051 | if (!check_bounds_or_overlap (as_a <gcall *>(stmt), dst, src, | |
2052 | dstsize, srcsize)) | |
2053 | { | |
2054 | gimple_set_no_warning (stmt, true); | |
2055 | return; | |
2056 | } | |
025d57f0 MS |
2057 | |
2058 | /* If the length argument was computed from strlen(S) for some string | |
2059 | S retrieve the strinfo index for the string (PSS->FIRST) alonng with | |
2060 | the location of the strlen() call (PSS->SECOND). */ | |
6a33d0ff | 2061 | stridx_strlenloc *pss = strlen_to_stridx->get (len); |
025d57f0 MS |
2062 | if (!pss || pss->first <= 0) |
2063 | { | |
2064 | if (maybe_diag_stxncpy_trunc (*gsi, src, len)) | |
2065 | gimple_set_no_warning (stmt, true); | |
2066 | ||
2067 | return; | |
2068 | } | |
2069 | ||
025d57f0 MS |
2070 | /* Retrieve the strinfo data for the string S that LEN was computed |
2071 | from as some function F of strlen (S) (i.e., LEN need not be equal | |
2072 | to strlen(S)). */ | |
2073 | strinfo *silen = get_strinfo (pss->first); | |
2074 | ||
e3329a78 MS |
2075 | location_t callloc = gimple_nonartificial_location (stmt); |
2076 | callloc = expansion_point_location_if_in_system_header (callloc); | |
025d57f0 MS |
2077 | |
2078 | tree func = gimple_call_fndecl (stmt); | |
2079 | ||
2080 | bool warned = false; | |
2081 | ||
2082 | /* When -Wstringop-truncation is set, try to determine truncation | |
2083 | before diagnosing possible overflow. Truncation is implied by | |
2084 | the LEN argument being equal to strlen(SRC), regardless of | |
2085 | whether its value is known. Otherwise, issue the more generic | |
2086 | -Wstringop-overflow which triggers for LEN arguments that in | |
2087 | any meaningful way depend on strlen(SRC). */ | |
6a33d0ff MS |
2088 | if (sisrc == silen |
2089 | && is_strlen_related_p (src, len) | |
2090 | && warning_at (callloc, OPT_Wstringop_truncation, | |
5d0d5d68 | 2091 | "%G%qD output truncated before terminating nul " |
6a33d0ff | 2092 | "copying as many bytes from a string as its length", |
5d0d5d68 | 2093 | as_a <gcall *>(stmt), func)) |
6a33d0ff | 2094 | warned = true; |
025d57f0 MS |
2095 | else if (silen && is_strlen_related_p (src, silen->ptr)) |
2096 | warned = warning_at (callloc, OPT_Wstringop_overflow_, | |
5d0d5d68 MS |
2097 | "%G%qD specified bound depends on the length " |
2098 | "of the source argument", | |
2099 | as_a <gcall *>(stmt), func); | |
025d57f0 MS |
2100 | if (warned) |
2101 | { | |
2102 | location_t strlenloc = pss->second; | |
2103 | if (strlenloc != UNKNOWN_LOCATION && strlenloc != callloc) | |
2104 | inform (strlenloc, "length computed here"); | |
2105 | } | |
2106 | } | |
2107 | ||
8b57bfeb JJ |
2108 | /* Handle a memcpy-like ({mem{,p}cpy,__mem{,p}cpy_chk}) call. |
2109 | If strlen of the second argument is known and length of the third argument | |
2110 | is that plus one, strlen of the first argument is the same after this | |
2111 | call. */ | |
2112 | ||
2113 | static void | |
2114 | handle_builtin_memcpy (enum built_in_function bcode, gimple_stmt_iterator *gsi) | |
2115 | { | |
2116 | int idx, didx; | |
2117 | tree src, dst, len, lhs, oldlen, newlen; | |
355fe088 | 2118 | gimple *stmt = gsi_stmt (*gsi); |
526ceb68 | 2119 | strinfo *si, *dsi, *olddsi; |
8b57bfeb | 2120 | |
31db0fe0 ML |
2121 | len = gimple_call_arg (stmt, 2); |
2122 | src = gimple_call_arg (stmt, 1); | |
8b57bfeb JJ |
2123 | dst = gimple_call_arg (stmt, 0); |
2124 | idx = get_stridx (src); | |
2125 | if (idx == 0) | |
2126 | return; | |
2127 | ||
2128 | didx = get_stridx (dst); | |
2129 | olddsi = NULL; | |
2130 | if (didx > 0) | |
2131 | olddsi = get_strinfo (didx); | |
2132 | else if (didx < 0) | |
2133 | return; | |
2134 | ||
2135 | if (olddsi != NULL | |
cc269bb6 | 2136 | && tree_fits_uhwi_p (len) |
8b57bfeb JJ |
2137 | && !integer_zerop (len)) |
2138 | adjust_last_stmt (olddsi, stmt, false); | |
2139 | ||
e3f9a279 | 2140 | bool full_string_p; |
8b57bfeb JJ |
2141 | if (idx > 0) |
2142 | { | |
355fe088 | 2143 | gimple *def_stmt; |
8b57bfeb | 2144 | |
e3f9a279 RS |
2145 | /* Handle memcpy (x, y, l) where l's relationship with strlen (y) |
2146 | is known. */ | |
8b57bfeb | 2147 | si = get_strinfo (idx); |
e3f9a279 | 2148 | if (si == NULL || si->nonzero_chars == NULL_TREE) |
8b57bfeb | 2149 | return; |
e3f9a279 RS |
2150 | if (TREE_CODE (len) == INTEGER_CST |
2151 | && TREE_CODE (si->nonzero_chars) == INTEGER_CST) | |
2152 | { | |
2153 | if (tree_int_cst_le (len, si->nonzero_chars)) | |
2154 | { | |
2155 | /* Copying LEN nonzero characters, where LEN is constant. */ | |
2156 | newlen = len; | |
2157 | full_string_p = false; | |
2158 | } | |
2159 | else | |
2160 | { | |
2161 | /* Copying the whole of the analyzed part of SI. */ | |
2162 | newlen = si->nonzero_chars; | |
2163 | full_string_p = si->full_string_p; | |
2164 | } | |
2165 | } | |
2166 | else | |
2167 | { | |
2168 | if (!si->full_string_p) | |
2169 | return; | |
2170 | if (TREE_CODE (len) != SSA_NAME) | |
2171 | return; | |
2172 | def_stmt = SSA_NAME_DEF_STMT (len); | |
2173 | if (!is_gimple_assign (def_stmt) | |
2174 | || gimple_assign_rhs_code (def_stmt) != PLUS_EXPR | |
2175 | || gimple_assign_rhs1 (def_stmt) != si->nonzero_chars | |
2176 | || !integer_onep (gimple_assign_rhs2 (def_stmt))) | |
2177 | return; | |
2178 | /* Copying variable-length string SI (and no more). */ | |
2179 | newlen = si->nonzero_chars; | |
2180 | full_string_p = true; | |
2181 | } | |
8b57bfeb JJ |
2182 | } |
2183 | else | |
2184 | { | |
2185 | si = NULL; | |
2186 | /* Handle memcpy (x, "abcd", 5) or | |
2187 | memcpy (x, "abc\0uvw", 7). */ | |
e3f9a279 | 2188 | if (!tree_fits_uhwi_p (len)) |
8b57bfeb | 2189 | return; |
e3f9a279 RS |
2190 | |
2191 | unsigned HOST_WIDE_INT clen = tree_to_uhwi (len); | |
2192 | unsigned HOST_WIDE_INT nonzero_chars = ~idx; | |
2193 | newlen = build_int_cst (size_type_node, MIN (nonzero_chars, clen)); | |
2194 | full_string_p = clen > nonzero_chars; | |
8b57bfeb JJ |
2195 | } |
2196 | ||
2197 | if (olddsi != NULL && TREE_CODE (len) == SSA_NAME) | |
2198 | adjust_last_stmt (olddsi, stmt, false); | |
2199 | ||
2200 | if (didx == 0) | |
2201 | { | |
2202 | didx = new_stridx (dst); | |
2203 | if (didx == 0) | |
2204 | return; | |
2205 | } | |
8b57bfeb JJ |
2206 | oldlen = NULL_TREE; |
2207 | if (olddsi != NULL) | |
2208 | { | |
2209 | dsi = unshare_strinfo (olddsi); | |
e3f9a279 RS |
2210 | oldlen = olddsi->nonzero_chars; |
2211 | dsi->nonzero_chars = newlen; | |
2212 | dsi->full_string_p = full_string_p; | |
8b57bfeb JJ |
2213 | /* Break the chain, so adjust_related_strinfo on later pointers in |
2214 | the chain won't adjust this one anymore. */ | |
2215 | dsi->next = 0; | |
2216 | dsi->stmt = NULL; | |
2217 | dsi->endptr = NULL_TREE; | |
2218 | } | |
2219 | else | |
2220 | { | |
e3f9a279 | 2221 | dsi = new_strinfo (dst, didx, newlen, full_string_p); |
8b57bfeb JJ |
2222 | set_strinfo (didx, dsi); |
2223 | find_equal_ptrs (dst, didx); | |
2224 | } | |
2225 | dsi->writable = true; | |
2226 | dsi->dont_invalidate = true; | |
2227 | if (olddsi != NULL) | |
2228 | { | |
2229 | tree adj = NULL_TREE; | |
2230 | location_t loc = gimple_location (stmt); | |
2231 | if (oldlen == NULL_TREE) | |
2232 | ; | |
2233 | else if (integer_zerop (oldlen)) | |
e3f9a279 | 2234 | adj = newlen; |
8b57bfeb | 2235 | else if (TREE_CODE (oldlen) == INTEGER_CST |
e3f9a279 RS |
2236 | || TREE_CODE (newlen) == INTEGER_CST) |
2237 | adj = fold_build2_loc (loc, MINUS_EXPR, TREE_TYPE (newlen), newlen, | |
2238 | fold_convert_loc (loc, TREE_TYPE (newlen), | |
8b57bfeb JJ |
2239 | oldlen)); |
2240 | if (adj != NULL_TREE) | |
2241 | adjust_related_strinfos (loc, dsi, adj); | |
2242 | else | |
2243 | dsi->prev = 0; | |
2244 | } | |
2245 | /* memcpy src may not overlap dst, so src doesn't need to be | |
2246 | invalidated either. */ | |
2247 | if (si != NULL) | |
2248 | si->dont_invalidate = true; | |
2249 | ||
e3f9a279 | 2250 | if (full_string_p) |
8b57bfeb | 2251 | { |
e3f9a279 RS |
2252 | lhs = gimple_call_lhs (stmt); |
2253 | switch (bcode) | |
2254 | { | |
2255 | case BUILT_IN_MEMCPY: | |
2256 | case BUILT_IN_MEMCPY_CHK: | |
e3f9a279 RS |
2257 | /* Allow adjust_last_stmt to decrease this memcpy's size. */ |
2258 | laststmt.stmt = stmt; | |
2259 | laststmt.len = dsi->nonzero_chars; | |
2260 | laststmt.stridx = dsi->idx; | |
2261 | if (lhs) | |
2262 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] = didx; | |
2263 | break; | |
2264 | case BUILT_IN_MEMPCPY: | |
2265 | case BUILT_IN_MEMPCPY_CHK: | |
e3f9a279 RS |
2266 | break; |
2267 | default: | |
2268 | gcc_unreachable (); | |
2269 | } | |
8b57bfeb JJ |
2270 | } |
2271 | } | |
2272 | ||
2273 | /* Handle a strcat-like ({strcat,__strcat_chk}) call. | |
2274 | If strlen of the second argument is known, strlen of the first argument | |
2275 | is increased by the length of the second argument. Furthermore, attempt | |
2276 | to convert it to memcpy/strcpy if the length of the first argument | |
2277 | is known. */ | |
2278 | ||
2279 | static void | |
2280 | handle_builtin_strcat (enum built_in_function bcode, gimple_stmt_iterator *gsi) | |
2281 | { | |
2282 | int idx, didx; | |
cc8bea0a | 2283 | tree srclen, args, type, fn, objsz, endptr; |
8b57bfeb | 2284 | bool success; |
355fe088 | 2285 | gimple *stmt = gsi_stmt (*gsi); |
526ceb68 | 2286 | strinfo *si, *dsi; |
cc8bea0a | 2287 | location_t loc = gimple_location (stmt); |
8b57bfeb | 2288 | |
31db0fe0 | 2289 | tree src = gimple_call_arg (stmt, 1); |
cc8bea0a MS |
2290 | tree dst = gimple_call_arg (stmt, 0); |
2291 | ||
2292 | /* Bail if the source is the same as destination. It will be diagnosed | |
2293 | elsewhere. */ | |
2294 | if (operand_equal_p (src, dst, 0)) | |
2295 | return; | |
2296 | ||
2297 | tree lhs = gimple_call_lhs (stmt); | |
8b57bfeb JJ |
2298 | |
2299 | didx = get_stridx (dst); | |
2300 | if (didx < 0) | |
2301 | return; | |
2302 | ||
2303 | dsi = NULL; | |
2304 | if (didx > 0) | |
2305 | dsi = get_strinfo (didx); | |
cc8bea0a MS |
2306 | |
2307 | srclen = NULL_TREE; | |
2308 | si = NULL; | |
2309 | idx = get_stridx (src); | |
2310 | if (idx < 0) | |
2311 | srclen = build_int_cst (size_type_node, ~idx); | |
2312 | else if (idx > 0) | |
2313 | { | |
2314 | si = get_strinfo (idx); | |
2315 | if (si != NULL) | |
2316 | srclen = get_string_length (si); | |
2317 | } | |
2318 | ||
2319 | /* Set the no-warning bit on the transformed statement? */ | |
2320 | bool set_no_warning = false; | |
2321 | ||
8b57bfeb JJ |
2322 | if (dsi == NULL || get_string_length (dsi) == NULL_TREE) |
2323 | { | |
cc8bea0a MS |
2324 | { |
2325 | /* The concatenation always involves copying at least one byte | |
2326 | (the terminating nul), even if the source string is empty. | |
2327 | If the source is unknown assume it's one character long and | |
2328 | used that as both sizes. */ | |
2329 | tree slen = srclen; | |
2330 | if (slen) | |
2331 | { | |
2332 | tree type = TREE_TYPE (slen); | |
2333 | slen = fold_build2 (PLUS_EXPR, type, slen, build_int_cst (type, 1)); | |
2334 | } | |
2335 | ||
2336 | tree sptr = si && si->ptr ? si->ptr : src; | |
2337 | ||
2338 | if (!check_bounds_or_overlap (as_a <gcall *>(stmt), dst, sptr, | |
2339 | NULL_TREE, slen)) | |
2340 | { | |
2341 | gimple_set_no_warning (stmt, true); | |
2342 | set_no_warning = true; | |
2343 | } | |
2344 | } | |
2345 | ||
8b57bfeb | 2346 | /* strcat (p, q) can be transformed into |
cc8bea0a | 2347 | tmp = p + strlen (p); endptr = stpcpy (tmp, q); |
8b57bfeb JJ |
2348 | with length endptr - p if we need to compute the length |
2349 | later on. Don't do this transformation if we don't need | |
2350 | it. */ | |
e79983f4 | 2351 | if (builtin_decl_implicit_p (BUILT_IN_STPCPY) && lhs == NULL_TREE) |
8b57bfeb JJ |
2352 | { |
2353 | if (didx == 0) | |
2354 | { | |
2355 | didx = new_stridx (dst); | |
2356 | if (didx == 0) | |
2357 | return; | |
2358 | } | |
2359 | if (dsi == NULL) | |
2360 | { | |
e3f9a279 | 2361 | dsi = new_strinfo (dst, didx, NULL_TREE, false); |
8b57bfeb JJ |
2362 | set_strinfo (didx, dsi); |
2363 | find_equal_ptrs (dst, didx); | |
2364 | } | |
2365 | else | |
2366 | { | |
2367 | dsi = unshare_strinfo (dsi); | |
e3f9a279 RS |
2368 | dsi->nonzero_chars = NULL_TREE; |
2369 | dsi->full_string_p = false; | |
8b57bfeb JJ |
2370 | dsi->next = 0; |
2371 | dsi->endptr = NULL_TREE; | |
2372 | } | |
2373 | dsi->writable = true; | |
2374 | dsi->stmt = stmt; | |
2375 | dsi->dont_invalidate = true; | |
2376 | } | |
2377 | return; | |
2378 | } | |
2379 | ||
cc8bea0a | 2380 | tree dstlen = dsi->nonzero_chars; |
8b57bfeb JJ |
2381 | endptr = dsi->endptr; |
2382 | ||
2383 | dsi = unshare_strinfo (dsi); | |
2384 | dsi->endptr = NULL_TREE; | |
2385 | dsi->stmt = NULL; | |
2386 | dsi->writable = true; | |
2387 | ||
2388 | if (srclen != NULL_TREE) | |
2389 | { | |
e3f9a279 RS |
2390 | dsi->nonzero_chars = fold_build2_loc (loc, PLUS_EXPR, |
2391 | TREE_TYPE (dsi->nonzero_chars), | |
2392 | dsi->nonzero_chars, srclen); | |
2393 | gcc_assert (dsi->full_string_p); | |
8b57bfeb JJ |
2394 | adjust_related_strinfos (loc, dsi, srclen); |
2395 | dsi->dont_invalidate = true; | |
2396 | } | |
2397 | else | |
2398 | { | |
e3f9a279 RS |
2399 | dsi->nonzero_chars = NULL; |
2400 | dsi->full_string_p = false; | |
e79983f4 | 2401 | if (lhs == NULL_TREE && builtin_decl_implicit_p (BUILT_IN_STPCPY)) |
8b57bfeb JJ |
2402 | dsi->dont_invalidate = true; |
2403 | } | |
2404 | ||
2405 | if (si != NULL) | |
2406 | /* strcat src may not overlap dst, so src doesn't need to be | |
2407 | invalidated either. */ | |
2408 | si->dont_invalidate = true; | |
2409 | ||
2410 | /* For now. Could remove the lhs from the call and add | |
2411 | lhs = dst; afterwards. */ | |
2412 | if (lhs) | |
2413 | return; | |
2414 | ||
2415 | fn = NULL_TREE; | |
2416 | objsz = NULL_TREE; | |
2417 | switch (bcode) | |
2418 | { | |
2419 | case BUILT_IN_STRCAT: | |
2420 | if (srclen != NULL_TREE) | |
e79983f4 | 2421 | fn = builtin_decl_implicit (BUILT_IN_MEMCPY); |
8b57bfeb | 2422 | else |
e79983f4 | 2423 | fn = builtin_decl_implicit (BUILT_IN_STRCPY); |
8b57bfeb JJ |
2424 | break; |
2425 | case BUILT_IN_STRCAT_CHK: | |
2426 | if (srclen != NULL_TREE) | |
e79983f4 | 2427 | fn = builtin_decl_explicit (BUILT_IN_MEMCPY_CHK); |
8b57bfeb | 2428 | else |
e79983f4 | 2429 | fn = builtin_decl_explicit (BUILT_IN_STRCPY_CHK); |
31db0fe0 | 2430 | objsz = gimple_call_arg (stmt, 2); |
8b57bfeb JJ |
2431 | break; |
2432 | default: | |
2433 | gcc_unreachable (); | |
2434 | } | |
2435 | ||
2436 | if (fn == NULL_TREE) | |
2437 | return; | |
2438 | ||
cc8bea0a MS |
2439 | if (dsi && dstlen) |
2440 | { | |
2441 | tree type = TREE_TYPE (dstlen); | |
2442 | ||
2443 | /* Compute the size of the source sequence, including the nul. */ | |
2444 | tree srcsize = srclen ? srclen : size_zero_node; | |
2445 | srcsize = fold_build2 (PLUS_EXPR, type, srcsize, build_int_cst (type, 1)); | |
2446 | ||
2447 | tree sptr = si && si->ptr ? si->ptr : src; | |
2448 | ||
2449 | if (!check_bounds_or_overlap (as_a <gcall *>(stmt), dst, sptr, | |
2450 | dstlen, srcsize)) | |
2451 | { | |
2452 | gimple_set_no_warning (stmt, true); | |
2453 | set_no_warning = true; | |
2454 | } | |
2455 | } | |
2456 | ||
2457 | tree len = NULL_TREE; | |
8b57bfeb JJ |
2458 | if (srclen != NULL_TREE) |
2459 | { | |
2460 | args = TYPE_ARG_TYPES (TREE_TYPE (fn)); | |
2461 | type = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (args))); | |
2462 | ||
2463 | len = fold_convert_loc (loc, type, unshare_expr (srclen)); | |
2464 | len = fold_build2_loc (loc, PLUS_EXPR, type, len, | |
2465 | build_int_cst (type, 1)); | |
2466 | len = force_gimple_operand_gsi (gsi, len, true, NULL_TREE, true, | |
2467 | GSI_SAME_STMT); | |
2468 | } | |
2469 | if (endptr) | |
2470 | dst = fold_convert_loc (loc, TREE_TYPE (dst), unshare_expr (endptr)); | |
2471 | else | |
2472 | dst = fold_build2_loc (loc, POINTER_PLUS_EXPR, | |
2473 | TREE_TYPE (dst), unshare_expr (dst), | |
2474 | fold_convert_loc (loc, sizetype, | |
2475 | unshare_expr (dstlen))); | |
2476 | dst = force_gimple_operand_gsi (gsi, dst, true, NULL_TREE, true, | |
2477 | GSI_SAME_STMT); | |
2478 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
2479 | { | |
2480 | fprintf (dump_file, "Optimizing: "); | |
2481 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
2482 | } | |
31db0fe0 ML |
2483 | if (srclen != NULL_TREE) |
2484 | success = update_gimple_call (gsi, fn, 3 + (objsz != NULL_TREE), | |
2485 | dst, src, len, objsz); | |
8b57bfeb | 2486 | else |
31db0fe0 ML |
2487 | success = update_gimple_call (gsi, fn, 2 + (objsz != NULL_TREE), |
2488 | dst, src, objsz); | |
8b57bfeb JJ |
2489 | if (success) |
2490 | { | |
2491 | stmt = gsi_stmt (*gsi); | |
2492 | update_stmt (stmt); | |
2493 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
2494 | { | |
2495 | fprintf (dump_file, "into: "); | |
2496 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
2497 | } | |
2498 | /* If srclen == NULL, note that current string length can be | |
2499 | computed by transforming this strcpy into stpcpy. */ | |
2500 | if (srclen == NULL_TREE && dsi->dont_invalidate) | |
2501 | dsi->stmt = stmt; | |
2502 | adjust_last_stmt (dsi, stmt, true); | |
2503 | if (srclen != NULL_TREE) | |
2504 | { | |
2505 | laststmt.stmt = stmt; | |
2506 | laststmt.len = srclen; | |
2507 | laststmt.stridx = dsi->idx; | |
2508 | } | |
2509 | } | |
2510 | else if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
2511 | fprintf (dump_file, "not possible.\n"); | |
cc8bea0a MS |
2512 | |
2513 | if (set_no_warning) | |
2514 | gimple_set_no_warning (stmt, true); | |
8b57bfeb JJ |
2515 | } |
2516 | ||
24314386 MG |
2517 | /* Handle a call to malloc or calloc. */ |
2518 | ||
2519 | static void | |
2520 | handle_builtin_malloc (enum built_in_function bcode, gimple_stmt_iterator *gsi) | |
2521 | { | |
355fe088 | 2522 | gimple *stmt = gsi_stmt (*gsi); |
24314386 | 2523 | tree lhs = gimple_call_lhs (stmt); |
a71dcca8 ML |
2524 | if (lhs == NULL_TREE) |
2525 | return; | |
2526 | ||
24314386 MG |
2527 | gcc_assert (get_stridx (lhs) == 0); |
2528 | int idx = new_stridx (lhs); | |
2529 | tree length = NULL_TREE; | |
2530 | if (bcode == BUILT_IN_CALLOC) | |
2531 | length = build_int_cst (size_type_node, 0); | |
e3f9a279 | 2532 | strinfo *si = new_strinfo (lhs, idx, length, length != NULL_TREE); |
24314386 MG |
2533 | if (bcode == BUILT_IN_CALLOC) |
2534 | si->endptr = lhs; | |
2535 | set_strinfo (idx, si); | |
2536 | si->writable = true; | |
2537 | si->stmt = stmt; | |
2538 | si->dont_invalidate = true; | |
2539 | } | |
2540 | ||
2541 | /* Handle a call to memset. | |
2542 | After a call to calloc, memset(,0,) is unnecessary. | |
8b0b334a QZ |
2543 | memset(malloc(n),0,n) is calloc(n,1). |
2544 | return true when the call is transfomred, false otherwise. */ | |
24314386 MG |
2545 | |
2546 | static bool | |
2547 | handle_builtin_memset (gimple_stmt_iterator *gsi) | |
2548 | { | |
355fe088 | 2549 | gimple *stmt2 = gsi_stmt (*gsi); |
24314386 | 2550 | if (!integer_zerop (gimple_call_arg (stmt2, 1))) |
8b0b334a | 2551 | return false; |
24314386 MG |
2552 | tree ptr = gimple_call_arg (stmt2, 0); |
2553 | int idx1 = get_stridx (ptr); | |
2554 | if (idx1 <= 0) | |
8b0b334a | 2555 | return false; |
526ceb68 | 2556 | strinfo *si1 = get_strinfo (idx1); |
24314386 | 2557 | if (!si1) |
8b0b334a | 2558 | return false; |
355fe088 | 2559 | gimple *stmt1 = si1->stmt; |
24314386 | 2560 | if (!stmt1 || !is_gimple_call (stmt1)) |
8b0b334a | 2561 | return false; |
24314386 | 2562 | tree callee1 = gimple_call_fndecl (stmt1); |
0ad84f34 | 2563 | if (!valid_builtin_call (stmt1)) |
8b0b334a | 2564 | return false; |
24314386 MG |
2565 | enum built_in_function code1 = DECL_FUNCTION_CODE (callee1); |
2566 | tree size = gimple_call_arg (stmt2, 2); | |
2567 | if (code1 == BUILT_IN_CALLOC) | |
2568 | /* Not touching stmt1 */ ; | |
2569 | else if (code1 == BUILT_IN_MALLOC | |
2570 | && operand_equal_p (gimple_call_arg (stmt1, 0), size, 0)) | |
2571 | { | |
2572 | gimple_stmt_iterator gsi1 = gsi_for_stmt (stmt1); | |
2573 | update_gimple_call (&gsi1, builtin_decl_implicit (BUILT_IN_CALLOC), 2, | |
2574 | size, build_one_cst (size_type_node)); | |
e3f9a279 RS |
2575 | si1->nonzero_chars = build_int_cst (size_type_node, 0); |
2576 | si1->full_string_p = true; | |
20cb2258 | 2577 | si1->stmt = gsi_stmt (gsi1); |
24314386 MG |
2578 | } |
2579 | else | |
8b0b334a | 2580 | return false; |
24314386 MG |
2581 | tree lhs = gimple_call_lhs (stmt2); |
2582 | unlink_stmt_vdef (stmt2); | |
2583 | if (lhs) | |
2584 | { | |
355fe088 | 2585 | gimple *assign = gimple_build_assign (lhs, ptr); |
24314386 MG |
2586 | gsi_replace (gsi, assign, false); |
2587 | } | |
2588 | else | |
2589 | { | |
2590 | gsi_remove (gsi, true); | |
2591 | release_defs (stmt2); | |
2592 | } | |
2593 | ||
8b0b334a | 2594 | return true; |
24314386 MG |
2595 | } |
2596 | ||
36b85e43 BS |
2597 | /* Handle a call to memcmp. We try to handle small comparisons by |
2598 | converting them to load and compare, and replacing the call to memcmp | |
8b0b334a QZ |
2599 | with a __builtin_memcmp_eq call where possible. |
2600 | return true when call is transformed, return false otherwise. */ | |
36b85e43 BS |
2601 | |
2602 | static bool | |
2603 | handle_builtin_memcmp (gimple_stmt_iterator *gsi) | |
2604 | { | |
2605 | gcall *stmt2 = as_a <gcall *> (gsi_stmt (*gsi)); | |
2606 | tree res = gimple_call_lhs (stmt2); | |
2607 | tree arg1 = gimple_call_arg (stmt2, 0); | |
2608 | tree arg2 = gimple_call_arg (stmt2, 1); | |
2609 | tree len = gimple_call_arg (stmt2, 2); | |
2610 | unsigned HOST_WIDE_INT leni; | |
2611 | use_operand_p use_p; | |
2612 | imm_use_iterator iter; | |
2613 | ||
2614 | if (!res) | |
8b0b334a | 2615 | return false; |
36b85e43 BS |
2616 | |
2617 | FOR_EACH_IMM_USE_FAST (use_p, iter, res) | |
2618 | { | |
2619 | gimple *ustmt = USE_STMT (use_p); | |
2620 | ||
73d73b48 BS |
2621 | if (is_gimple_debug (ustmt)) |
2622 | continue; | |
36b85e43 BS |
2623 | if (gimple_code (ustmt) == GIMPLE_ASSIGN) |
2624 | { | |
2625 | gassign *asgn = as_a <gassign *> (ustmt); | |
2626 | tree_code code = gimple_assign_rhs_code (asgn); | |
2627 | if ((code != EQ_EXPR && code != NE_EXPR) | |
2628 | || !integer_zerop (gimple_assign_rhs2 (asgn))) | |
8b0b334a | 2629 | return false; |
36b85e43 BS |
2630 | } |
2631 | else if (gimple_code (ustmt) == GIMPLE_COND) | |
2632 | { | |
2633 | tree_code code = gimple_cond_code (ustmt); | |
2634 | if ((code != EQ_EXPR && code != NE_EXPR) | |
2635 | || !integer_zerop (gimple_cond_rhs (ustmt))) | |
8b0b334a | 2636 | return false; |
36b85e43 BS |
2637 | } |
2638 | else | |
8b0b334a | 2639 | return false; |
36b85e43 BS |
2640 | } |
2641 | ||
2642 | if (tree_fits_uhwi_p (len) | |
2643 | && (leni = tree_to_uhwi (len)) <= GET_MODE_SIZE (word_mode) | |
146ec50f | 2644 | && pow2p_hwi (leni)) |
36b85e43 BS |
2645 | { |
2646 | leni *= CHAR_TYPE_SIZE; | |
2647 | unsigned align1 = get_pointer_alignment (arg1); | |
2648 | unsigned align2 = get_pointer_alignment (arg2); | |
2649 | unsigned align = MIN (align1, align2); | |
fffbab82 RS |
2650 | scalar_int_mode mode; |
2651 | if (int_mode_for_size (leni, 1).exists (&mode) | |
e0bd6c9f | 2652 | && (align >= leni || !targetm.slow_unaligned_access (mode, align))) |
36b85e43 BS |
2653 | { |
2654 | location_t loc = gimple_location (stmt2); | |
2655 | tree type, off; | |
2656 | type = build_nonstandard_integer_type (leni, 1); | |
73a699ae | 2657 | gcc_assert (known_eq (GET_MODE_BITSIZE (TYPE_MODE (type)), leni)); |
36b85e43 BS |
2658 | tree ptrtype = build_pointer_type_for_mode (char_type_node, |
2659 | ptr_mode, true); | |
2660 | off = build_int_cst (ptrtype, 0); | |
2661 | arg1 = build2_loc (loc, MEM_REF, type, arg1, off); | |
2662 | arg2 = build2_loc (loc, MEM_REF, type, arg2, off); | |
2663 | tree tem1 = fold_const_aggregate_ref (arg1); | |
2664 | if (tem1) | |
2665 | arg1 = tem1; | |
2666 | tree tem2 = fold_const_aggregate_ref (arg2); | |
2667 | if (tem2) | |
2668 | arg2 = tem2; | |
2669 | res = fold_convert_loc (loc, TREE_TYPE (res), | |
2670 | fold_build2_loc (loc, NE_EXPR, | |
2671 | boolean_type_node, | |
2672 | arg1, arg2)); | |
2673 | gimplify_and_update_call_from_tree (gsi, res); | |
8b0b334a | 2674 | return true; |
36b85e43 BS |
2675 | } |
2676 | } | |
2677 | ||
2678 | gimple_call_set_fndecl (stmt2, builtin_decl_explicit (BUILT_IN_MEMCMP_EQ)); | |
8b0b334a QZ |
2679 | return true; |
2680 | } | |
2681 | ||
2682 | /* Given an index to the strinfo vector, compute the string length for the | |
2683 | corresponding string. Return -1 when unknown. */ | |
2684 | ||
2685 | static HOST_WIDE_INT | |
2686 | compute_string_length (int idx) | |
2687 | { | |
2688 | HOST_WIDE_INT string_leni = -1; | |
2689 | gcc_assert (idx != 0); | |
2690 | ||
2691 | if (idx < 0) | |
2692 | return ~idx; | |
2693 | ||
2694 | strinfo *si = get_strinfo (idx); | |
2695 | if (si) | |
2696 | { | |
2697 | tree const_string_len = get_string_length (si); | |
2698 | if (const_string_len && tree_fits_shwi_p (const_string_len)) | |
2699 | string_leni = tree_to_shwi (const_string_len); | |
2700 | } | |
2701 | ||
2702 | if (string_leni < 0) | |
2703 | return -1; | |
2704 | ||
2705 | return string_leni; | |
2706 | } | |
2707 | ||
2708 | /* Determine the minimum size of the object referenced by DEST expression which | |
2709 | must have a pointer type. | |
2710 | Return the minimum size of the object if successful or NULL when the size | |
2711 | cannot be determined. */ | |
2712 | static tree | |
2713 | determine_min_objsize (tree dest) | |
2714 | { | |
2715 | unsigned HOST_WIDE_INT size = 0; | |
2716 | ||
2717 | if (compute_builtin_object_size (dest, 2, &size)) | |
2718 | return build_int_cst (sizetype, size); | |
2719 | ||
2720 | /* Try to determine the size of the object through the RHS of the | |
2721 | assign statement. */ | |
2722 | if (TREE_CODE (dest) == SSA_NAME) | |
2723 | { | |
2724 | gimple *stmt = SSA_NAME_DEF_STMT (dest); | |
2725 | if (!is_gimple_assign (stmt)) | |
2726 | return NULL_TREE; | |
2727 | ||
2728 | if (!gimple_assign_single_p (stmt) | |
2729 | && !gimple_assign_unary_nop_p (stmt)) | |
2730 | return NULL_TREE; | |
2731 | ||
2732 | dest = gimple_assign_rhs1 (stmt); | |
2733 | return determine_min_objsize (dest); | |
2734 | } | |
2735 | ||
2736 | /* Try to determine the size of the object from its type. */ | |
2737 | if (TREE_CODE (dest) != ADDR_EXPR) | |
2738 | return NULL_TREE; | |
2739 | ||
2740 | tree type = TREE_TYPE (dest); | |
2741 | if (TREE_CODE (type) == POINTER_TYPE) | |
2742 | type = TREE_TYPE (type); | |
2743 | ||
2744 | type = TYPE_MAIN_VARIANT (type); | |
2745 | ||
2746 | /* We cannot determine the size of the array if it's a flexible array, | |
2747 | which is declared at the end of a structure. */ | |
2748 | if (TREE_CODE (type) == ARRAY_TYPE | |
2749 | && !array_at_struct_end_p (dest)) | |
2750 | { | |
2751 | tree size_t = TYPE_SIZE_UNIT (type); | |
2752 | if (size_t && TREE_CODE (size_t) == INTEGER_CST | |
2753 | && !integer_zerop (size_t)) | |
2754 | return size_t; | |
2755 | } | |
2756 | ||
2757 | return NULL_TREE; | |
2758 | } | |
2759 | ||
2760 | /* Handle a call to strcmp or strncmp. When the result is ONLY used to do | |
2761 | equality test against zero: | |
2762 | ||
2763 | A. When the lengths of both arguments are constant and it's a strcmp: | |
2764 | * if the lengths are NOT equal, we can safely fold the call | |
2765 | to a non-zero value. | |
2766 | * otherwise, do nothing now. | |
2767 | ||
2768 | B. When the length of one argument is constant, try to replace the call with | |
2769 | a __builtin_str(n)cmp_eq call where possible, i.e: | |
2770 | ||
2771 | strncmp (s, STR, C) (!)= 0 in which, s is a pointer to a string, STR is a | |
2772 | string with constant length , C is a constant. | |
2773 | if (C <= strlen(STR) && sizeof_array(s) > C) | |
2774 | { | |
2775 | replace this call with | |
2776 | strncmp_eq (s, STR, C) (!)= 0 | |
2777 | } | |
2778 | if (C > strlen(STR) | |
2779 | { | |
2780 | it can be safely treated as a call to strcmp (s, STR) (!)= 0 | |
2781 | can handled by the following strcmp. | |
2782 | } | |
2783 | ||
2784 | strcmp (s, STR) (!)= 0 in which, s is a pointer to a string, STR is a | |
2785 | string with constant length. | |
2786 | if (sizeof_array(s) > strlen(STR)) | |
2787 | { | |
2788 | replace this call with | |
2789 | strcmp_eq (s, STR, strlen(STR)+1) (!)= 0 | |
2790 | } | |
2791 | ||
2792 | Return true when the call is transformed, return false otherwise. | |
2793 | */ | |
2794 | ||
2795 | static bool | |
2796 | handle_builtin_string_cmp (gimple_stmt_iterator *gsi) | |
2797 | { | |
2798 | gcall *stmt = as_a <gcall *> (gsi_stmt (*gsi)); | |
2799 | tree res = gimple_call_lhs (stmt); | |
2800 | use_operand_p use_p; | |
2801 | imm_use_iterator iter; | |
2802 | tree arg1 = gimple_call_arg (stmt, 0); | |
2803 | tree arg2 = gimple_call_arg (stmt, 1); | |
2804 | int idx1 = get_stridx (arg1); | |
2805 | int idx2 = get_stridx (arg2); | |
2806 | HOST_WIDE_INT length = -1; | |
2807 | bool is_ncmp = false; | |
2808 | ||
2809 | if (!res) | |
2810 | return false; | |
2811 | ||
2812 | /* When both arguments are unknown, do nothing. */ | |
2813 | if (idx1 == 0 && idx2 == 0) | |
2814 | return false; | |
2815 | ||
2816 | /* Handle strncmp function. */ | |
2817 | if (gimple_call_num_args (stmt) == 3) | |
2818 | { | |
2819 | tree len = gimple_call_arg (stmt, 2); | |
2820 | if (tree_fits_shwi_p (len)) | |
2821 | length = tree_to_shwi (len); | |
2822 | ||
2823 | is_ncmp = true; | |
2824 | } | |
2825 | ||
2826 | /* For strncmp, if the length argument is NOT known, do nothing. */ | |
2827 | if (is_ncmp && length < 0) | |
2828 | return false; | |
2829 | ||
2830 | /* When the result is ONLY used to do equality test against zero. */ | |
2831 | FOR_EACH_IMM_USE_FAST (use_p, iter, res) | |
2832 | { | |
2833 | gimple *use_stmt = USE_STMT (use_p); | |
2834 | ||
2835 | if (is_gimple_debug (use_stmt)) | |
2836 | continue; | |
2837 | if (gimple_code (use_stmt) == GIMPLE_ASSIGN) | |
2838 | { | |
2839 | tree_code code = gimple_assign_rhs_code (use_stmt); | |
2840 | if (code == COND_EXPR) | |
2841 | { | |
2842 | tree cond_expr = gimple_assign_rhs1 (use_stmt); | |
2843 | if ((TREE_CODE (cond_expr) != EQ_EXPR | |
2844 | && (TREE_CODE (cond_expr) != NE_EXPR)) | |
2845 | || !integer_zerop (TREE_OPERAND (cond_expr, 1))) | |
2846 | return false; | |
2847 | } | |
2848 | else if (code == EQ_EXPR || code == NE_EXPR) | |
2849 | { | |
2850 | if (!integer_zerop (gimple_assign_rhs2 (use_stmt))) | |
2851 | return false; | |
2852 | } | |
2853 | else | |
2854 | return false; | |
2855 | } | |
2856 | else if (gimple_code (use_stmt) == GIMPLE_COND) | |
2857 | { | |
2858 | tree_code code = gimple_cond_code (use_stmt); | |
2859 | if ((code != EQ_EXPR && code != NE_EXPR) | |
2860 | || !integer_zerop (gimple_cond_rhs (use_stmt))) | |
2861 | return false; | |
2862 | } | |
2863 | else | |
2864 | return false; | |
2865 | } | |
2866 | ||
2867 | /* When the lengths of both arguments are known, and they are unequal, we can | |
2868 | safely fold the call to a non-zero value for strcmp; | |
2869 | othewise, do nothing now. */ | |
2870 | if (idx1 != 0 && idx2 != 0) | |
2871 | { | |
2872 | HOST_WIDE_INT const_string_leni1 = compute_string_length (idx1); | |
2873 | HOST_WIDE_INT const_string_leni2 = compute_string_length (idx2); | |
2874 | ||
2875 | if (!is_ncmp | |
2876 | && const_string_leni1 != -1 | |
2877 | && const_string_leni2 != -1 | |
2878 | && const_string_leni1 != const_string_leni2) | |
2879 | { | |
2880 | replace_call_with_value (gsi, integer_one_node); | |
2881 | return true; | |
2882 | } | |
2883 | return false; | |
2884 | } | |
2885 | ||
2886 | /* When the length of one argument is constant. */ | |
2887 | tree var_string = NULL_TREE; | |
2888 | HOST_WIDE_INT const_string_leni = -1; | |
2889 | ||
2890 | if (idx1) | |
2891 | { | |
2892 | const_string_leni = compute_string_length (idx1); | |
2893 | var_string = arg2; | |
2894 | } | |
2895 | else | |
2896 | { | |
2897 | gcc_checking_assert (idx2); | |
2898 | const_string_leni = compute_string_length (idx2); | |
2899 | var_string = arg1; | |
2900 | } | |
2901 | ||
2902 | if (const_string_leni < 0) | |
2903 | return false; | |
2904 | ||
2905 | unsigned HOST_WIDE_INT var_sizei = 0; | |
2906 | /* try to determine the minimum size of the object pointed by var_string. */ | |
2907 | tree size = determine_min_objsize (var_string); | |
2908 | ||
2909 | if (!size) | |
2910 | return false; | |
2911 | ||
2912 | if (tree_fits_uhwi_p (size)) | |
2913 | var_sizei = tree_to_uhwi (size); | |
2914 | ||
2915 | if (var_sizei == 0) | |
2916 | return false; | |
2917 | ||
2918 | /* For strncmp, if length > const_string_leni , this call can be safely | |
2919 | transformed to a strcmp. */ | |
2920 | if (is_ncmp && length > const_string_leni) | |
2921 | is_ncmp = false; | |
2922 | ||
2923 | unsigned HOST_WIDE_INT final_length | |
2924 | = is_ncmp ? length : const_string_leni + 1; | |
2925 | ||
2926 | /* Replace strcmp or strncmp with the corresponding str(n)cmp_eq. */ | |
2927 | if (var_sizei > final_length) | |
2928 | { | |
2929 | tree fn | |
2930 | = (is_ncmp | |
2931 | ? builtin_decl_implicit (BUILT_IN_STRNCMP_EQ) | |
2932 | : builtin_decl_implicit (BUILT_IN_STRCMP_EQ)); | |
2933 | if (!fn) | |
2934 | return false; | |
2935 | tree const_string_len = build_int_cst (size_type_node, final_length); | |
2936 | update_gimple_call (gsi, fn, 3, arg1, arg2, const_string_len); | |
2937 | } | |
2938 | else | |
2939 | return false; | |
2940 | ||
2941 | return true; | |
36b85e43 BS |
2942 | } |
2943 | ||
8b57bfeb JJ |
2944 | /* Handle a POINTER_PLUS_EXPR statement. |
2945 | For p = "abcd" + 2; compute associated length, or if | |
2946 | p = q + off is pointing to a '\0' character of a string, call | |
2947 | zero_length_string on it. */ | |
2948 | ||
2949 | static void | |
2950 | handle_pointer_plus (gimple_stmt_iterator *gsi) | |
2951 | { | |
355fe088 | 2952 | gimple *stmt = gsi_stmt (*gsi); |
8b57bfeb JJ |
2953 | tree lhs = gimple_assign_lhs (stmt), off; |
2954 | int idx = get_stridx (gimple_assign_rhs1 (stmt)); | |
526ceb68 | 2955 | strinfo *si, *zsi; |
8b57bfeb JJ |
2956 | |
2957 | if (idx == 0) | |
2958 | return; | |
2959 | ||
2960 | if (idx < 0) | |
2961 | { | |
2962 | tree off = gimple_assign_rhs2 (stmt); | |
cc269bb6 | 2963 | if (tree_fits_uhwi_p (off) |
7d362f6c | 2964 | && tree_to_uhwi (off) <= (unsigned HOST_WIDE_INT) ~idx) |
9771b263 | 2965 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] |
ae7e9ddd | 2966 | = ~(~idx - (int) tree_to_uhwi (off)); |
8b57bfeb JJ |
2967 | return; |
2968 | } | |
2969 | ||
2970 | si = get_strinfo (idx); | |
e3f9a279 | 2971 | if (si == NULL || si->nonzero_chars == NULL_TREE) |
8b57bfeb JJ |
2972 | return; |
2973 | ||
2974 | off = gimple_assign_rhs2 (stmt); | |
2975 | zsi = NULL; | |
e3f9a279 | 2976 | if (si->full_string_p && operand_equal_p (si->nonzero_chars, off, 0)) |
8b57bfeb JJ |
2977 | zsi = zero_length_string (lhs, si); |
2978 | else if (TREE_CODE (off) == SSA_NAME) | |
2979 | { | |
355fe088 | 2980 | gimple *def_stmt = SSA_NAME_DEF_STMT (off); |
8b57bfeb | 2981 | if (gimple_assign_single_p (def_stmt) |
e3f9a279 RS |
2982 | && si->full_string_p |
2983 | && operand_equal_p (si->nonzero_chars, | |
2984 | gimple_assign_rhs1 (def_stmt), 0)) | |
8b57bfeb JJ |
2985 | zsi = zero_length_string (lhs, si); |
2986 | } | |
2987 | if (zsi != NULL | |
2988 | && si->endptr != NULL_TREE | |
2989 | && si->endptr != lhs | |
2990 | && TREE_CODE (si->endptr) == SSA_NAME) | |
2991 | { | |
2992 | enum tree_code rhs_code | |
2993 | = useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (si->endptr)) | |
2994 | ? SSA_NAME : NOP_EXPR; | |
00d66391 | 2995 | gimple_assign_set_rhs_with_ops (gsi, rhs_code, si->endptr); |
8b57bfeb JJ |
2996 | gcc_assert (gsi_stmt (*gsi) == stmt); |
2997 | update_stmt (stmt); | |
2998 | } | |
2999 | } | |
3000 | ||
a011292a MS |
3001 | /* If RHS, either directly or indirectly, refers to a string of constant |
3002 | length, return it. Otherwise return a negative value. */ | |
3003 | ||
3004 | static HOST_WIDE_INT | |
3005 | get_string_cst_length (tree rhs) | |
65f2d1ee PK |
3006 | { |
3007 | if (TREE_CODE (rhs) == MEM_REF | |
3008 | && integer_zerop (TREE_OPERAND (rhs, 1))) | |
3009 | { | |
a011292a | 3010 | rhs = TREE_OPERAND (rhs, 0); |
65f2d1ee | 3011 | if (TREE_CODE (rhs) == ADDR_EXPR) |
05ef3173 | 3012 | { |
a011292a MS |
3013 | tree rhs_addr = rhs; |
3014 | ||
05ef3173 MS |
3015 | rhs = TREE_OPERAND (rhs, 0); |
3016 | if (TREE_CODE (rhs) != STRING_CST) | |
3017 | { | |
3018 | int idx = get_stridx (rhs_addr); | |
3019 | if (idx > 0) | |
3020 | { | |
3021 | strinfo *si = get_strinfo (idx); | |
a011292a MS |
3022 | if (si |
3023 | && si->full_string_p | |
3024 | && tree_fits_shwi_p (si->nonzero_chars)) | |
05ef3173 MS |
3025 | return tree_to_shwi (si->nonzero_chars); |
3026 | } | |
3027 | } | |
3028 | } | |
3029 | } | |
3030 | ||
3031 | if (TREE_CODE (rhs) == VAR_DECL | |
3032 | && TREE_READONLY (rhs)) | |
3033 | rhs = DECL_INITIAL (rhs); | |
3034 | ||
3035 | if (rhs && TREE_CODE (rhs) == STRING_CST) | |
a011292a | 3036 | return strlen (TREE_STRING_POINTER (rhs)); |
65f2d1ee | 3037 | |
05ef3173 | 3038 | return -1; |
65f2d1ee PK |
3039 | } |
3040 | ||
8b57bfeb JJ |
3041 | /* Handle a single character store. */ |
3042 | ||
3043 | static bool | |
3044 | handle_char_store (gimple_stmt_iterator *gsi) | |
3045 | { | |
3046 | int idx = -1; | |
526ceb68 | 3047 | strinfo *si = NULL; |
355fe088 | 3048 | gimple *stmt = gsi_stmt (*gsi); |
8b57bfeb | 3049 | tree ssaname = NULL_TREE, lhs = gimple_assign_lhs (stmt); |
e3f9a279 RS |
3050 | tree rhs = gimple_assign_rhs1 (stmt); |
3051 | unsigned HOST_WIDE_INT offset = 0; | |
8b57bfeb JJ |
3052 | |
3053 | if (TREE_CODE (lhs) == MEM_REF | |
3054 | && TREE_CODE (TREE_OPERAND (lhs, 0)) == SSA_NAME) | |
3055 | { | |
e3f9a279 RS |
3056 | tree mem_offset = TREE_OPERAND (lhs, 1); |
3057 | if (tree_fits_uhwi_p (mem_offset)) | |
8b57bfeb | 3058 | { |
e3f9a279 RS |
3059 | /* Get the strinfo for the base, and use it if it starts with at |
3060 | least OFFSET nonzero characters. This is trivially true if | |
3061 | OFFSET is zero. */ | |
3062 | offset = tree_to_uhwi (mem_offset); | |
3063 | idx = get_stridx (TREE_OPERAND (lhs, 0)); | |
3064 | if (idx > 0) | |
3065 | si = get_strinfo (idx); | |
3066 | if (offset == 0) | |
3067 | ssaname = TREE_OPERAND (lhs, 0); | |
3068 | else if (si == NULL || compare_nonzero_chars (si, offset) < 0) | |
3069 | return true; | |
8b57bfeb JJ |
3070 | } |
3071 | } | |
3072 | else | |
e3f9a279 RS |
3073 | { |
3074 | idx = get_addr_stridx (lhs, NULL_TREE, &offset); | |
3075 | if (idx > 0) | |
3076 | si = get_strinfo (idx); | |
3077 | } | |
8b57bfeb | 3078 | |
e3f9a279 | 3079 | bool storing_zero_p = initializer_zerop (rhs); |
223c63e6 | 3080 | bool storing_nonzero_p = !storing_zero_p && tree_expr_nonzero_p (rhs); |
a011292a MS |
3081 | /* Set to the length of the string being assigned if known. */ |
3082 | HOST_WIDE_INT rhslen; | |
e3f9a279 RS |
3083 | |
3084 | if (si != NULL) | |
8b57bfeb | 3085 | { |
e3f9a279 RS |
3086 | int cmp = compare_nonzero_chars (si, offset); |
3087 | gcc_assert (offset == 0 || cmp >= 0); | |
3088 | if (storing_zero_p && cmp == 0 && si->full_string_p) | |
8b57bfeb | 3089 | { |
e3f9a279 RS |
3090 | /* When overwriting a '\0' with a '\0', the store can be removed |
3091 | if we know it has been stored in the current function. */ | |
3092 | if (!stmt_could_throw_p (stmt) && si->writable) | |
8b57bfeb | 3093 | { |
e3f9a279 RS |
3094 | unlink_stmt_vdef (stmt); |
3095 | release_defs (stmt); | |
3096 | gsi_remove (gsi, true); | |
3097 | return false; | |
8b57bfeb JJ |
3098 | } |
3099 | else | |
e3f9a279 RS |
3100 | { |
3101 | si->writable = true; | |
3102 | gsi_next (gsi); | |
3103 | return false; | |
3104 | } | |
8b57bfeb | 3105 | } |
e3f9a279 | 3106 | /* If si->nonzero_chars > OFFSET, we aren't overwriting '\0', |
5b115c1f MP |
3107 | and if we aren't storing '\0', we know that the length of the |
3108 | string and any other zero terminated string in memory remains | |
3109 | the same. In that case we move to the next gimple statement and | |
3110 | return to signal the caller that it shouldn't invalidate anything. | |
3111 | ||
3112 | This is benefical for cases like: | |
3113 | ||
3114 | char p[20]; | |
3115 | void foo (char *q) | |
3116 | { | |
3117 | strcpy (p, "foobar"); | |
3118 | size_t len = strlen (p); // This can be optimized into 6 | |
3119 | size_t len2 = strlen (q); // This has to be computed | |
3120 | p[0] = 'X'; | |
3121 | size_t len3 = strlen (p); // This can be optimized into 6 | |
3122 | size_t len4 = strlen (q); // This can be optimized into len2 | |
3123 | bar (len, len2, len3, len4); | |
3124 | } | |
3125 | */ | |
e3f9a279 | 3126 | else if (storing_nonzero_p && cmp > 0) |
5b115c1f MP |
3127 | { |
3128 | gsi_next (gsi); | |
3129 | return false; | |
3130 | } | |
e3f9a279 RS |
3131 | else if (storing_zero_p || storing_nonzero_p || (offset != 0 && cmp > 0)) |
3132 | { | |
3133 | /* When storing_nonzero_p, we know that the string now starts | |
3134 | with OFFSET + 1 nonzero characters, but don't know whether | |
3135 | there's a following nul terminator. | |
3136 | ||
3137 | When storing_zero_p, we know that the string is now OFFSET | |
3138 | characters long. | |
3139 | ||
3140 | Otherwise, we're storing an unknown value at offset OFFSET, | |
3141 | so need to clip the nonzero_chars to OFFSET. */ | |
3142 | location_t loc = gimple_location (stmt); | |
3143 | tree oldlen = si->nonzero_chars; | |
3144 | if (cmp == 0 && si->full_string_p) | |
3145 | /* We're overwriting the nul terminator with a nonzero or | |
3146 | unknown character. If the previous stmt was a memcpy, | |
3147 | its length may be decreased. */ | |
3148 | adjust_last_stmt (si, stmt, false); | |
3149 | si = unshare_strinfo (si); | |
3150 | if (storing_nonzero_p) | |
3151 | si->nonzero_chars = build_int_cst (size_type_node, offset + 1); | |
3152 | else | |
3153 | si->nonzero_chars = build_int_cst (size_type_node, offset); | |
3154 | si->full_string_p = storing_zero_p; | |
3155 | if (storing_zero_p | |
3156 | && ssaname | |
3157 | && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ssaname)) | |
3158 | si->endptr = ssaname; | |
3159 | else | |
3160 | si->endptr = NULL; | |
3161 | si->next = 0; | |
3162 | si->stmt = NULL; | |
3163 | si->writable = true; | |
3164 | si->dont_invalidate = true; | |
3165 | if (oldlen) | |
3166 | { | |
3167 | tree adj = fold_build2_loc (loc, MINUS_EXPR, size_type_node, | |
3168 | si->nonzero_chars, oldlen); | |
3169 | adjust_related_strinfos (loc, si, adj); | |
3170 | } | |
3171 | else | |
3172 | si->prev = 0; | |
3173 | } | |
8b57bfeb | 3174 | } |
e3f9a279 | 3175 | else if (idx == 0 && (storing_zero_p || storing_nonzero_p)) |
8b57bfeb JJ |
3176 | { |
3177 | if (ssaname) | |
e3f9a279 | 3178 | idx = new_stridx (ssaname); |
8b57bfeb | 3179 | else |
e3f9a279 RS |
3180 | idx = new_addr_stridx (lhs); |
3181 | if (idx != 0) | |
8b57bfeb | 3182 | { |
e3f9a279 RS |
3183 | tree ptr = (ssaname ? ssaname : build_fold_addr_expr (lhs)); |
3184 | tree len = storing_nonzero_p ? size_one_node : size_zero_node; | |
3185 | si = new_strinfo (ptr, idx, len, storing_zero_p); | |
3186 | set_strinfo (idx, si); | |
3187 | if (storing_zero_p | |
3188 | && ssaname | |
3189 | && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ssaname)) | |
3190 | si->endptr = ssaname; | |
3191 | si->dont_invalidate = true; | |
3192 | si->writable = true; | |
8b57bfeb | 3193 | } |
8b57bfeb | 3194 | } |
198fe1bf | 3195 | else if (idx == 0 |
a011292a | 3196 | && (rhslen = get_string_cst_length (gimple_assign_rhs1 (stmt))) >= 0 |
198fe1bf JJ |
3197 | && ssaname == NULL_TREE |
3198 | && TREE_CODE (TREE_TYPE (lhs)) == ARRAY_TYPE) | |
3199 | { | |
198fe1bf | 3200 | HOST_WIDE_INT a = int_size_in_bytes (TREE_TYPE (lhs)); |
05ef3173 | 3201 | if (a > 0 && (unsigned HOST_WIDE_INT) a > (unsigned HOST_WIDE_INT) rhslen) |
198fe1bf JJ |
3202 | { |
3203 | int idx = new_addr_stridx (lhs); | |
3204 | if (idx != 0) | |
3205 | { | |
3206 | si = new_strinfo (build_fold_addr_expr (lhs), idx, | |
05ef3173 | 3207 | build_int_cst (size_type_node, rhslen), true); |
198fe1bf JJ |
3208 | set_strinfo (idx, si); |
3209 | si->dont_invalidate = true; | |
3210 | } | |
3211 | } | |
3212 | } | |
8b57bfeb | 3213 | |
e3f9a279 | 3214 | if (si != NULL && offset == 0 && storing_zero_p) |
8b57bfeb JJ |
3215 | { |
3216 | /* Allow adjust_last_stmt to remove it if the stored '\0' | |
3217 | is immediately overwritten. */ | |
3218 | laststmt.stmt = stmt; | |
3219 | laststmt.len = build_int_cst (size_type_node, 1); | |
3220 | laststmt.stridx = si->idx; | |
3221 | } | |
3222 | return true; | |
3223 | } | |
3224 | ||
f368600f | 3225 | /* Try to fold strstr (s, t) eq/ne s to strncmp (s, t, strlen (t)) eq/ne 0. */ |
3b1970cb PK |
3226 | |
3227 | static void | |
f368600f | 3228 | fold_strstr_to_strncmp (tree rhs1, tree rhs2, gimple *stmt) |
3b1970cb PK |
3229 | { |
3230 | if (TREE_CODE (rhs1) != SSA_NAME | |
3231 | || TREE_CODE (rhs2) != SSA_NAME) | |
3232 | return; | |
3233 | ||
3234 | gimple *call_stmt = NULL; | |
3235 | for (int pass = 0; pass < 2; pass++) | |
3236 | { | |
3237 | gimple *g = SSA_NAME_DEF_STMT (rhs1); | |
3238 | if (gimple_call_builtin_p (g, BUILT_IN_STRSTR) | |
3239 | && has_single_use (rhs1) | |
3240 | && gimple_call_arg (g, 0) == rhs2) | |
3241 | { | |
3242 | call_stmt = g; | |
3243 | break; | |
3244 | } | |
3245 | std::swap (rhs1, rhs2); | |
3246 | } | |
3247 | ||
3248 | if (call_stmt) | |
3249 | { | |
3250 | tree arg0 = gimple_call_arg (call_stmt, 0); | |
3251 | ||
3252 | if (arg0 == rhs2) | |
3253 | { | |
3254 | tree arg1 = gimple_call_arg (call_stmt, 1); | |
3255 | tree arg1_len = NULL_TREE; | |
3256 | int idx = get_stridx (arg1); | |
3257 | ||
3258 | if (idx) | |
3259 | { | |
3260 | if (idx < 0) | |
3261 | arg1_len = build_int_cst (size_type_node, ~idx); | |
3262 | else | |
3263 | { | |
3264 | strinfo *si = get_strinfo (idx); | |
3265 | if (si) | |
3266 | arg1_len = get_string_length (si); | |
3267 | } | |
3268 | } | |
3269 | ||
3270 | if (arg1_len != NULL_TREE) | |
3271 | { | |
3272 | gimple_stmt_iterator gsi = gsi_for_stmt (call_stmt); | |
f368600f | 3273 | tree strncmp_decl = builtin_decl_explicit (BUILT_IN_STRNCMP); |
96863f32 ML |
3274 | |
3275 | if (!is_gimple_val (arg1_len)) | |
3276 | { | |
3277 | tree arg1_len_tmp = make_ssa_name (TREE_TYPE (arg1_len)); | |
3278 | gassign *arg1_stmt = gimple_build_assign (arg1_len_tmp, | |
3279 | arg1_len); | |
3280 | gsi_insert_before (&gsi, arg1_stmt, GSI_SAME_STMT); | |
3281 | arg1_len = arg1_len_tmp; | |
3282 | } | |
3283 | ||
f368600f | 3284 | gcall *strncmp_call = gimple_build_call (strncmp_decl, 3, |
3b1970cb | 3285 | arg0, arg1, arg1_len); |
f368600f ML |
3286 | tree strncmp_lhs = make_ssa_name (integer_type_node); |
3287 | gimple_set_vuse (strncmp_call, gimple_vuse (call_stmt)); | |
3288 | gimple_call_set_lhs (strncmp_call, strncmp_lhs); | |
3b1970cb | 3289 | gsi_remove (&gsi, true); |
f368600f ML |
3290 | gsi_insert_before (&gsi, strncmp_call, GSI_SAME_STMT); |
3291 | tree zero = build_zero_cst (TREE_TYPE (strncmp_lhs)); | |
3b1970cb PK |
3292 | |
3293 | if (is_gimple_assign (stmt)) | |
3294 | { | |
3295 | if (gimple_assign_rhs_code (stmt) == COND_EXPR) | |
3296 | { | |
3297 | tree cond = gimple_assign_rhs1 (stmt); | |
f368600f | 3298 | TREE_OPERAND (cond, 0) = strncmp_lhs; |
3b1970cb PK |
3299 | TREE_OPERAND (cond, 1) = zero; |
3300 | } | |
3301 | else | |
3302 | { | |
f368600f | 3303 | gimple_assign_set_rhs1 (stmt, strncmp_lhs); |
3b1970cb PK |
3304 | gimple_assign_set_rhs2 (stmt, zero); |
3305 | } | |
3306 | } | |
3307 | else | |
3308 | { | |
3309 | gcond *cond = as_a<gcond *> (stmt); | |
f368600f | 3310 | gimple_cond_set_lhs (cond, strncmp_lhs); |
3b1970cb PK |
3311 | gimple_cond_set_rhs (cond, zero); |
3312 | } | |
3313 | update_stmt (stmt); | |
3314 | } | |
3315 | } | |
3316 | } | |
3317 | } | |
3318 | ||
cc8bea0a | 3319 | /* Attempt to check for validity of the performed access a single statement |
fa9544ab ML |
3320 | at *GSI using string length knowledge, and to optimize it. |
3321 | If the given basic block needs clean-up of EH, CLEANUP_EH is set to | |
3322 | true. */ | |
8b57bfeb JJ |
3323 | |
3324 | static bool | |
fa9544ab | 3325 | strlen_check_and_optimize_stmt (gimple_stmt_iterator *gsi, bool *cleanup_eh) |
8b57bfeb | 3326 | { |
355fe088 | 3327 | gimple *stmt = gsi_stmt (*gsi); |
8b57bfeb JJ |
3328 | |
3329 | if (is_gimple_call (stmt)) | |
3330 | { | |
3331 | tree callee = gimple_call_fndecl (stmt); | |
0ad84f34 | 3332 | if (valid_builtin_call (stmt)) |
8b57bfeb JJ |
3333 | switch (DECL_FUNCTION_CODE (callee)) |
3334 | { | |
3335 | case BUILT_IN_STRLEN: | |
3336 | handle_builtin_strlen (gsi); | |
3337 | break; | |
3338 | case BUILT_IN_STRCHR: | |
3339 | handle_builtin_strchr (gsi); | |
3340 | break; | |
3341 | case BUILT_IN_STRCPY: | |
3342 | case BUILT_IN_STRCPY_CHK: | |
3343 | case BUILT_IN_STPCPY: | |
3344 | case BUILT_IN_STPCPY_CHK: | |
3345 | handle_builtin_strcpy (DECL_FUNCTION_CODE (callee), gsi); | |
3346 | break; | |
025d57f0 MS |
3347 | |
3348 | case BUILT_IN_STRNCAT: | |
3349 | case BUILT_IN_STRNCAT_CHK: | |
3350 | handle_builtin_strncat (DECL_FUNCTION_CODE (callee), gsi); | |
3351 | break; | |
3352 | ||
3353 | case BUILT_IN_STPNCPY: | |
3354 | case BUILT_IN_STPNCPY_CHK: | |
3355 | case BUILT_IN_STRNCPY: | |
3356 | case BUILT_IN_STRNCPY_CHK: | |
3357 | handle_builtin_stxncpy (DECL_FUNCTION_CODE (callee), gsi); | |
3358 | break; | |
3359 | ||
8b57bfeb JJ |
3360 | case BUILT_IN_MEMCPY: |
3361 | case BUILT_IN_MEMCPY_CHK: | |
3362 | case BUILT_IN_MEMPCPY: | |
3363 | case BUILT_IN_MEMPCPY_CHK: | |
3364 | handle_builtin_memcpy (DECL_FUNCTION_CODE (callee), gsi); | |
3365 | break; | |
3366 | case BUILT_IN_STRCAT: | |
3367 | case BUILT_IN_STRCAT_CHK: | |
3368 | handle_builtin_strcat (DECL_FUNCTION_CODE (callee), gsi); | |
3369 | break; | |
24314386 MG |
3370 | case BUILT_IN_MALLOC: |
3371 | case BUILT_IN_CALLOC: | |
3372 | handle_builtin_malloc (DECL_FUNCTION_CODE (callee), gsi); | |
3373 | break; | |
3374 | case BUILT_IN_MEMSET: | |
8b0b334a | 3375 | if (handle_builtin_memset (gsi)) |
24314386 MG |
3376 | return false; |
3377 | break; | |
36b85e43 | 3378 | case BUILT_IN_MEMCMP: |
8b0b334a QZ |
3379 | if (handle_builtin_memcmp (gsi)) |
3380 | return false; | |
3381 | break; | |
3382 | case BUILT_IN_STRCMP: | |
3383 | case BUILT_IN_STRNCMP: | |
3384 | if (handle_builtin_string_cmp (gsi)) | |
36b85e43 BS |
3385 | return false; |
3386 | break; | |
8b57bfeb JJ |
3387 | default: |
3388 | break; | |
3389 | } | |
3390 | } | |
5004bd00 | 3391 | else if (is_gimple_assign (stmt) && !gimple_clobber_p (stmt)) |
8b57bfeb JJ |
3392 | { |
3393 | tree lhs = gimple_assign_lhs (stmt); | |
3394 | ||
3395 | if (TREE_CODE (lhs) == SSA_NAME && POINTER_TYPE_P (TREE_TYPE (lhs))) | |
3396 | { | |
3397 | if (gimple_assign_single_p (stmt) | |
3398 | || (gimple_assign_cast_p (stmt) | |
3399 | && POINTER_TYPE_P (TREE_TYPE (gimple_assign_rhs1 (stmt))))) | |
3400 | { | |
3401 | int idx = get_stridx (gimple_assign_rhs1 (stmt)); | |
9771b263 | 3402 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] = idx; |
8b57bfeb JJ |
3403 | } |
3404 | else if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR) | |
3405 | handle_pointer_plus (gsi); | |
3406 | } | |
3b1970cb PK |
3407 | else if (TREE_CODE (lhs) == SSA_NAME && INTEGRAL_TYPE_P (TREE_TYPE (lhs))) |
3408 | { | |
3409 | enum tree_code code = gimple_assign_rhs_code (stmt); | |
3410 | if (code == COND_EXPR) | |
3411 | { | |
3412 | tree cond = gimple_assign_rhs1 (stmt); | |
3413 | enum tree_code cond_code = TREE_CODE (cond); | |
3414 | ||
3415 | if (cond_code == EQ_EXPR || cond_code == NE_EXPR) | |
f368600f ML |
3416 | fold_strstr_to_strncmp (TREE_OPERAND (cond, 0), |
3417 | TREE_OPERAND (cond, 1), stmt); | |
3b1970cb PK |
3418 | } |
3419 | else if (code == EQ_EXPR || code == NE_EXPR) | |
f368600f ML |
3420 | fold_strstr_to_strncmp (gimple_assign_rhs1 (stmt), |
3421 | gimple_assign_rhs2 (stmt), stmt); | |
f744bfec JJ |
3422 | else if (gimple_assign_load_p (stmt) |
3423 | && TREE_CODE (TREE_TYPE (lhs)) == INTEGER_TYPE | |
3424 | && TYPE_MODE (TREE_TYPE (lhs)) == TYPE_MODE (char_type_node) | |
3425 | && (TYPE_PRECISION (TREE_TYPE (lhs)) | |
3426 | == TYPE_PRECISION (char_type_node)) | |
3427 | && !gimple_has_volatile_ops (stmt)) | |
3428 | { | |
3429 | tree off = integer_zero_node; | |
3430 | unsigned HOST_WIDE_INT coff = 0; | |
ad2a970f | 3431 | int idx = 0; |
f744bfec JJ |
3432 | tree rhs1 = gimple_assign_rhs1 (stmt); |
3433 | if (code == MEM_REF) | |
3434 | { | |
3435 | idx = get_stridx (TREE_OPERAND (rhs1, 0)); | |
ad2a970f JJ |
3436 | if (idx > 0) |
3437 | { | |
3438 | strinfo *si = get_strinfo (idx); | |
3439 | if (si | |
3440 | && si->nonzero_chars | |
3441 | && TREE_CODE (si->nonzero_chars) == INTEGER_CST | |
3442 | && (wi::to_widest (si->nonzero_chars) | |
3443 | >= wi::to_widest (off))) | |
3444 | off = TREE_OPERAND (rhs1, 1); | |
3445 | else | |
3446 | /* This case is not useful. See if get_addr_stridx | |
3447 | returns something usable. */ | |
3448 | idx = 0; | |
3449 | } | |
f744bfec | 3450 | } |
ad2a970f | 3451 | if (idx <= 0) |
f744bfec JJ |
3452 | idx = get_addr_stridx (rhs1, NULL_TREE, &coff); |
3453 | if (idx > 0) | |
3454 | { | |
3455 | strinfo *si = get_strinfo (idx); | |
3456 | if (si | |
3457 | && si->nonzero_chars | |
3458 | && TREE_CODE (si->nonzero_chars) == INTEGER_CST) | |
3459 | { | |
3460 | widest_int w1 = wi::to_widest (si->nonzero_chars); | |
3461 | widest_int w2 = wi::to_widest (off) + coff; | |
3462 | if (w1 == w2 | |
3463 | && si->full_string_p) | |
3464 | { | |
fa9544ab ML |
3465 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) |
3466 | { | |
3467 | fprintf (dump_file, "Optimizing: "); | |
3468 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
3469 | } | |
3470 | ||
f744bfec JJ |
3471 | /* Reading the final '\0' character. */ |
3472 | tree zero = build_int_cst (TREE_TYPE (lhs), 0); | |
3473 | gimple_set_vuse (stmt, NULL_TREE); | |
3474 | gimple_assign_set_rhs_from_tree (gsi, zero); | |
fa9544ab ML |
3475 | *cleanup_eh |
3476 | |= maybe_clean_or_replace_eh_stmt (stmt, | |
3477 | gsi_stmt (*gsi)); | |
3478 | stmt = gsi_stmt (*gsi); | |
3479 | update_stmt (stmt); | |
3480 | ||
3481 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
3482 | { | |
3483 | fprintf (dump_file, "into: "); | |
3484 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
3485 | } | |
f744bfec JJ |
3486 | } |
3487 | else if (w1 > w2) | |
3488 | { | |
3489 | /* Reading a character before the final '\0' | |
3490 | character. Just set the value range to ~[0, 0] | |
3491 | if we don't have anything better. */ | |
3492 | wide_int min, max; | |
3493 | tree type = TREE_TYPE (lhs); | |
3494 | enum value_range_type vr | |
3495 | = get_range_info (lhs, &min, &max); | |
3496 | if (vr == VR_VARYING | |
3497 | || (vr == VR_RANGE | |
3498 | && min == wi::min_value (TYPE_PRECISION (type), | |
3499 | TYPE_SIGN (type)) | |
3500 | && max == wi::max_value (TYPE_PRECISION (type), | |
3501 | TYPE_SIGN (type)))) | |
3502 | set_range_info (lhs, VR_ANTI_RANGE, | |
3503 | wi::zero (TYPE_PRECISION (type)), | |
3504 | wi::zero (TYPE_PRECISION (type))); | |
3505 | } | |
3506 | } | |
3507 | } | |
3508 | } | |
025d57f0 | 3509 | |
6a33d0ff MS |
3510 | if (strlen_to_stridx) |
3511 | { | |
3512 | tree rhs1 = gimple_assign_rhs1 (stmt); | |
3513 | if (stridx_strlenloc *ps = strlen_to_stridx->get (rhs1)) | |
3514 | strlen_to_stridx->put (lhs, stridx_strlenloc (*ps)); | |
3515 | } | |
3b1970cb PK |
3516 | } |
3517 | else if (TREE_CODE (lhs) != SSA_NAME && !TREE_SIDE_EFFECTS (lhs)) | |
8b57bfeb JJ |
3518 | { |
3519 | tree type = TREE_TYPE (lhs); | |
3520 | if (TREE_CODE (type) == ARRAY_TYPE) | |
3521 | type = TREE_TYPE (type); | |
3522 | if (TREE_CODE (type) == INTEGER_TYPE | |
3523 | && TYPE_MODE (type) == TYPE_MODE (char_type_node) | |
3524 | && TYPE_PRECISION (type) == TYPE_PRECISION (char_type_node)) | |
3525 | { | |
3526 | if (! handle_char_store (gsi)) | |
3527 | return false; | |
3528 | } | |
3529 | } | |
3530 | } | |
3b1970cb PK |
3531 | else if (gcond *cond = dyn_cast<gcond *> (stmt)) |
3532 | { | |
3533 | enum tree_code code = gimple_cond_code (cond); | |
3534 | if (code == EQ_EXPR || code == NE_EXPR) | |
f368600f ML |
3535 | fold_strstr_to_strncmp (gimple_cond_lhs (stmt), |
3536 | gimple_cond_rhs (stmt), stmt); | |
3b1970cb | 3537 | } |
8b57bfeb JJ |
3538 | |
3539 | if (gimple_vdef (stmt)) | |
3540 | maybe_invalidate (stmt); | |
3541 | return true; | |
3542 | } | |
3543 | ||
3544 | /* Recursively call maybe_invalidate on stmts that might be executed | |
3545 | in between dombb and current bb and that contain a vdef. Stop when | |
3546 | *count stmts are inspected, or if the whole strinfo vector has | |
3547 | been invalidated. */ | |
3548 | ||
3549 | static void | |
355fe088 | 3550 | do_invalidate (basic_block dombb, gimple *phi, bitmap visited, int *count) |
8b57bfeb JJ |
3551 | { |
3552 | unsigned int i, n = gimple_phi_num_args (phi); | |
3553 | ||
3554 | for (i = 0; i < n; i++) | |
3555 | { | |
3556 | tree vuse = gimple_phi_arg_def (phi, i); | |
355fe088 | 3557 | gimple *stmt = SSA_NAME_DEF_STMT (vuse); |
8b57bfeb JJ |
3558 | basic_block bb = gimple_bb (stmt); |
3559 | if (bb == NULL | |
3560 | || bb == dombb | |
3561 | || !bitmap_set_bit (visited, bb->index) | |
3562 | || !dominated_by_p (CDI_DOMINATORS, bb, dombb)) | |
3563 | continue; | |
3564 | while (1) | |
3565 | { | |
3566 | if (gimple_code (stmt) == GIMPLE_PHI) | |
3567 | { | |
3568 | do_invalidate (dombb, stmt, visited, count); | |
3569 | if (*count == 0) | |
3570 | return; | |
3571 | break; | |
3572 | } | |
3573 | if (--*count == 0) | |
3574 | return; | |
3575 | if (!maybe_invalidate (stmt)) | |
3576 | { | |
3577 | *count = 0; | |
3578 | return; | |
3579 | } | |
3580 | vuse = gimple_vuse (stmt); | |
3581 | stmt = SSA_NAME_DEF_STMT (vuse); | |
3582 | if (gimple_bb (stmt) != bb) | |
3583 | { | |
3584 | bb = gimple_bb (stmt); | |
3585 | if (bb == NULL | |
3586 | || bb == dombb | |
3587 | || !bitmap_set_bit (visited, bb->index) | |
3588 | || !dominated_by_p (CDI_DOMINATORS, bb, dombb)) | |
3589 | break; | |
3590 | } | |
3591 | } | |
3592 | } | |
3593 | } | |
3594 | ||
4d9192b5 TS |
3595 | class strlen_dom_walker : public dom_walker |
3596 | { | |
3597 | public: | |
fa9544ab ML |
3598 | strlen_dom_walker (cdi_direction direction) |
3599 | : dom_walker (direction), m_cleanup_cfg (false) | |
3600 | {} | |
4d9192b5 | 3601 | |
3daacdcd | 3602 | virtual edge before_dom_children (basic_block); |
4d9192b5 | 3603 | virtual void after_dom_children (basic_block); |
fa9544ab ML |
3604 | |
3605 | /* Flag that will trigger TODO_cleanup_cfg to be returned in strlen | |
3606 | execute function. */ | |
3607 | bool m_cleanup_cfg; | |
4d9192b5 TS |
3608 | }; |
3609 | ||
8b57bfeb | 3610 | /* Callback for walk_dominator_tree. Attempt to optimize various |
c7880c8c | 3611 | string ops by remembering string lengths pointed by pointer SSA_NAMEs. */ |
8b57bfeb | 3612 | |
3daacdcd | 3613 | edge |
4d9192b5 | 3614 | strlen_dom_walker::before_dom_children (basic_block bb) |
8b57bfeb | 3615 | { |
8b57bfeb JJ |
3616 | basic_block dombb = get_immediate_dominator (CDI_DOMINATORS, bb); |
3617 | ||
3618 | if (dombb == NULL) | |
3619 | stridx_to_strinfo = NULL; | |
3620 | else | |
3621 | { | |
526ceb68 | 3622 | stridx_to_strinfo = ((vec<strinfo *, va_heap, vl_embed> *) dombb->aux); |
8b57bfeb JJ |
3623 | if (stridx_to_strinfo) |
3624 | { | |
538dd0b7 DM |
3625 | for (gphi_iterator gsi = gsi_start_phis (bb); !gsi_end_p (gsi); |
3626 | gsi_next (&gsi)) | |
8b57bfeb | 3627 | { |
538dd0b7 | 3628 | gphi *phi = gsi.phi (); |
ea057359 | 3629 | if (virtual_operand_p (gimple_phi_result (phi))) |
8b57bfeb JJ |
3630 | { |
3631 | bitmap visited = BITMAP_ALLOC (NULL); | |
3632 | int count_vdef = 100; | |
3633 | do_invalidate (dombb, phi, visited, &count_vdef); | |
3634 | BITMAP_FREE (visited); | |
8b29fd4e JJ |
3635 | if (count_vdef == 0) |
3636 | { | |
3637 | /* If there were too many vdefs in between immediate | |
3638 | dominator and current bb, invalidate everything. | |
3639 | If stridx_to_strinfo has been unshared, we need | |
3640 | to free it, otherwise just set it to NULL. */ | |
3641 | if (!strinfo_shared ()) | |
3642 | { | |
3643 | unsigned int i; | |
526ceb68 | 3644 | strinfo *si; |
8b29fd4e JJ |
3645 | |
3646 | for (i = 1; | |
3647 | vec_safe_iterate (stridx_to_strinfo, i, &si); | |
3648 | ++i) | |
3649 | { | |
3650 | free_strinfo (si); | |
3651 | (*stridx_to_strinfo)[i] = NULL; | |
3652 | } | |
3653 | } | |
3654 | else | |
3655 | stridx_to_strinfo = NULL; | |
3656 | } | |
8b57bfeb JJ |
3657 | break; |
3658 | } | |
3659 | } | |
3660 | } | |
3661 | } | |
3662 | ||
3663 | /* If all PHI arguments have the same string index, the PHI result | |
3664 | has it as well. */ | |
538dd0b7 DM |
3665 | for (gphi_iterator gsi = gsi_start_phis (bb); !gsi_end_p (gsi); |
3666 | gsi_next (&gsi)) | |
8b57bfeb | 3667 | { |
538dd0b7 | 3668 | gphi *phi = gsi.phi (); |
8b57bfeb | 3669 | tree result = gimple_phi_result (phi); |
ea057359 | 3670 | if (!virtual_operand_p (result) && POINTER_TYPE_P (TREE_TYPE (result))) |
8b57bfeb JJ |
3671 | { |
3672 | int idx = get_stridx (gimple_phi_arg_def (phi, 0)); | |
3673 | if (idx != 0) | |
3674 | { | |
3675 | unsigned int i, n = gimple_phi_num_args (phi); | |
3676 | for (i = 1; i < n; i++) | |
3677 | if (idx != get_stridx (gimple_phi_arg_def (phi, i))) | |
3678 | break; | |
3679 | if (i == n) | |
9771b263 | 3680 | ssa_ver_to_stridx[SSA_NAME_VERSION (result)] = idx; |
8b57bfeb JJ |
3681 | } |
3682 | } | |
3683 | } | |
3684 | ||
fa9544ab ML |
3685 | bool cleanup_eh = false; |
3686 | ||
8b57bfeb | 3687 | /* Attempt to optimize individual statements. */ |
538dd0b7 | 3688 | for (gimple_stmt_iterator gsi = gsi_start_bb (bb); !gsi_end_p (gsi); ) |
fa9544ab | 3689 | if (strlen_check_and_optimize_stmt (&gsi, &cleanup_eh)) |
8b57bfeb JJ |
3690 | gsi_next (&gsi); |
3691 | ||
fa9544ab ML |
3692 | if (cleanup_eh && gimple_purge_dead_eh_edges (bb)) |
3693 | m_cleanup_cfg = true; | |
3694 | ||
8b57bfeb | 3695 | bb->aux = stridx_to_strinfo; |
9771b263 | 3696 | if (vec_safe_length (stridx_to_strinfo) && !strinfo_shared ()) |
526ceb68 | 3697 | (*stridx_to_strinfo)[0] = (strinfo *) bb; |
3daacdcd | 3698 | return NULL; |
8b57bfeb JJ |
3699 | } |
3700 | ||
3701 | /* Callback for walk_dominator_tree. Free strinfo vector if it is | |
3702 | owned by the current bb, clear bb->aux. */ | |
3703 | ||
4d9192b5 TS |
3704 | void |
3705 | strlen_dom_walker::after_dom_children (basic_block bb) | |
8b57bfeb JJ |
3706 | { |
3707 | if (bb->aux) | |
3708 | { | |
526ceb68 | 3709 | stridx_to_strinfo = ((vec<strinfo *, va_heap, vl_embed> *) bb->aux); |
9771b263 | 3710 | if (vec_safe_length (stridx_to_strinfo) |
526ceb68 | 3711 | && (*stridx_to_strinfo)[0] == (strinfo *) bb) |
8b57bfeb JJ |
3712 | { |
3713 | unsigned int i; | |
526ceb68 | 3714 | strinfo *si; |
8b57bfeb | 3715 | |
9771b263 | 3716 | for (i = 1; vec_safe_iterate (stridx_to_strinfo, i, &si); ++i) |
8b57bfeb | 3717 | free_strinfo (si); |
9771b263 | 3718 | vec_free (stridx_to_strinfo); |
8b57bfeb JJ |
3719 | } |
3720 | bb->aux = NULL; | |
3721 | } | |
3722 | } | |
3723 | ||
3724 | /* Main entry point. */ | |
3725 | ||
27a4cd48 DM |
3726 | namespace { |
3727 | ||
3728 | const pass_data pass_data_strlen = | |
8b57bfeb | 3729 | { |
27a4cd48 DM |
3730 | GIMPLE_PASS, /* type */ |
3731 | "strlen", /* name */ | |
3732 | OPTGROUP_NONE, /* optinfo_flags */ | |
27a4cd48 DM |
3733 | TV_TREE_STRLEN, /* tv_id */ |
3734 | ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
3735 | 0, /* properties_provided */ | |
3736 | 0, /* properties_destroyed */ | |
3737 | 0, /* todo_flags_start */ | |
3bea341f | 3738 | 0, /* todo_flags_finish */ |
8b57bfeb | 3739 | }; |
27a4cd48 DM |
3740 | |
3741 | class pass_strlen : public gimple_opt_pass | |
3742 | { | |
3743 | public: | |
c3284718 RS |
3744 | pass_strlen (gcc::context *ctxt) |
3745 | : gimple_opt_pass (pass_data_strlen, ctxt) | |
27a4cd48 DM |
3746 | {} |
3747 | ||
3748 | /* opt_pass methods: */ | |
1a3d085c | 3749 | virtual bool gate (function *) { return flag_optimize_strlen != 0; } |
be55bfe6 | 3750 | virtual unsigned int execute (function *); |
27a4cd48 DM |
3751 | |
3752 | }; // class pass_strlen | |
3753 | ||
be55bfe6 TS |
3754 | unsigned int |
3755 | pass_strlen::execute (function *fun) | |
3756 | { | |
6a33d0ff MS |
3757 | gcc_assert (!strlen_to_stridx); |
3758 | if (warn_stringop_overflow || warn_stringop_truncation) | |
3759 | strlen_to_stridx = new hash_map<tree, stridx_strlenloc> (); | |
3760 | ||
be55bfe6 TS |
3761 | ssa_ver_to_stridx.safe_grow_cleared (num_ssa_names); |
3762 | max_stridx = 1; | |
be55bfe6 TS |
3763 | |
3764 | calculate_dominance_info (CDI_DOMINATORS); | |
3765 | ||
3766 | /* String length optimization is implemented as a walk of the dominator | |
3767 | tree and a forward walk of statements within each block. */ | |
fa9544ab ML |
3768 | strlen_dom_walker walker (CDI_DOMINATORS); |
3769 | walker.walk (fun->cfg->x_entry_block_ptr); | |
be55bfe6 TS |
3770 | |
3771 | ssa_ver_to_stridx.release (); | |
33e7d32e | 3772 | strinfo_pool.release (); |
c203e8a7 | 3773 | if (decl_to_stridxlist_htab) |
be55bfe6 TS |
3774 | { |
3775 | obstack_free (&stridx_obstack, NULL); | |
c203e8a7 TS |
3776 | delete decl_to_stridxlist_htab; |
3777 | decl_to_stridxlist_htab = NULL; | |
be55bfe6 TS |
3778 | } |
3779 | laststmt.stmt = NULL; | |
3780 | laststmt.len = NULL_TREE; | |
3781 | laststmt.stridx = 0; | |
3782 | ||
6a33d0ff MS |
3783 | if (strlen_to_stridx) |
3784 | { | |
3785 | strlen_to_stridx->empty (); | |
3786 | delete strlen_to_stridx; | |
3787 | strlen_to_stridx = NULL; | |
3788 | } | |
025d57f0 | 3789 | |
fa9544ab | 3790 | return walker.m_cleanup_cfg ? TODO_cleanup_cfg : 0; |
be55bfe6 TS |
3791 | } |
3792 | ||
27a4cd48 DM |
3793 | } // anon namespace |
3794 | ||
3795 | gimple_opt_pass * | |
3796 | make_pass_strlen (gcc::context *ctxt) | |
3797 | { | |
3798 | return new pass_strlen (ctxt); | |
3799 | } |