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9efe50a4 | 1 | /* String length optimization |
8e8f6434 | 2 | Copyright (C) 2011-2018 Free Software Foundation, Inc. |
9efe50a4 | 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" | |
9ef16211 | 24 | #include "backend.h" |
7c29e30e | 25 | #include "rtl.h" |
41a8aa41 | 26 | #include "tree.h" |
9ef16211 | 27 | #include "gimple.h" |
7c29e30e | 28 | #include "alloc-pool.h" |
29 | #include "tree-pass.h" | |
9ef16211 | 30 | #include "ssa.h" |
7c29e30e | 31 | #include "cgraph.h" |
32 | #include "gimple-pretty-print.h" | |
e6a18b5a | 33 | #include "gimple-ssa-warn-restrict.h" |
b20a8bb4 | 34 | #include "fold-const.h" |
9ed99284 | 35 | #include "stor-layout.h" |
bc61cadb | 36 | #include "gimple-fold.h" |
37 | #include "tree-eh.h" | |
a8783bee | 38 | #include "gimplify.h" |
dcf1a1ec | 39 | #include "gimple-iterator.h" |
e795d6e1 | 40 | #include "gimplify-me.h" |
9ed99284 | 41 | #include "expr.h" |
7626097e | 42 | #include "tree-cfg.h" |
073c1fd5 | 43 | #include "tree-dfa.h" |
9efe50a4 | 44 | #include "domwalk.h" |
d8aad786 | 45 | #include "tree-ssa-alias.h" |
9efe50a4 | 46 | #include "tree-ssa-propagate.h" |
bcb285a0 | 47 | #include "tree-ssa-strlen.h" |
9efe50a4 | 48 | #include "params.h" |
3c17973d | 49 | #include "tree-hash-traits.h" |
72dbc21d | 50 | #include "tree-object-size.h" |
3e346f54 | 51 | #include "builtins.h" |
dfdced85 | 52 | #include "target.h" |
d8aad786 | 53 | #include "diagnostic-core.h" |
54 | #include "diagnostic.h" | |
55 | #include "intl.h" | |
56 | #include "attribs.h" | |
0c45740b | 57 | #include "calls.h" |
9efe50a4 | 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). */ | |
f1f41a6c | 62 | static vec<int> ssa_ver_to_stridx; |
9efe50a4 | 63 | |
64 | /* Number of currently active string indexes plus one. */ | |
65 | static int max_stridx; | |
66 | ||
67 | /* String information record. */ | |
04009ada | 68 | struct strinfo |
9efe50a4 | 69 | { |
f6ab81c1 | 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; | |
9efe50a4 | 77 | /* Any of the corresponding pointers for querying alias oracle. */ |
78 | tree ptr; | |
85690345 | 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. */ | |
42acab1c | 86 | gimple *stmt; |
9efe50a4 | 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; | |
f6ab81c1 | 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; | |
04009ada | 127 | }; |
9efe50a4 | 128 | |
129 | /* Pool for allocating strinfo_struct entries. */ | |
04009ada | 130 | static object_allocator<strinfo> strinfo_pool ("strinfo pool"); |
9efe50a4 | 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. */ | |
04009ada | 138 | static vec<strinfo *, va_heap, vl_embed> *stridx_to_strinfo; |
9efe50a4 | 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. */ | |
ee34b0e4 | 157 | static hash_map<tree_decl_hash, stridxlist> *decl_to_stridxlist_htab; |
9efe50a4 | 158 | |
0c45740b | 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. */ | |
d8aad786 | 162 | typedef std::pair<int, location_t> stridx_strlenloc; |
0c45740b | 163 | static hash_map<tree, stridx_strlenloc> *strlen_to_stridx; |
d8aad786 | 164 | |
9efe50a4 | 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 | { | |
42acab1c | 173 | gimple *stmt; |
9efe50a4 | 174 | tree len; |
175 | int stridx; | |
176 | } laststmt; | |
177 | ||
f6ab81c1 | 178 | static int get_stridx_plus_constant (strinfo *, unsigned HOST_WIDE_INT, tree); |
e6a18b5a | 179 | static void handle_builtin_stxncpy (built_in_function, gimple_stmt_iterator *); |
f6ab81c1 | 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 | } | |
150a0f7d | 207 | |
208 | /* Return strinfo vector entry IDX. */ | |
209 | ||
04009ada | 210 | static inline strinfo * |
150a0f7d | 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 | ||
e4b21f53 | 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 | ||
f6ab81c1 | 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. */ | |
9efe50a4 | 235 | |
236 | static int | |
f6ab81c1 | 237 | get_addr_stridx (tree exp, tree ptr, unsigned HOST_WIDE_INT *offset_out) |
9efe50a4 | 238 | { |
239 | HOST_WIDE_INT off; | |
83b23cdf | 240 | struct stridxlist *list, *last = NULL; |
9efe50a4 | 241 | tree base; |
242 | ||
c1f445d2 | 243 | if (!decl_to_stridxlist_htab) |
9efe50a4 | 244 | return 0; |
245 | ||
773078cb | 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)) | |
9efe50a4 | 249 | return 0; |
250 | ||
d62dd039 | 251 | list = decl_to_stridxlist_htab->get (base); |
252 | if (list == NULL) | |
9efe50a4 | 253 | return 0; |
254 | ||
9efe50a4 | 255 | do |
256 | { | |
257 | if (list->offset == off) | |
f6ab81c1 | 258 | { |
259 | if (offset_out) | |
260 | *offset_out = 0; | |
261 | return list->idx; | |
262 | } | |
83b23cdf | 263 | if (list->offset > off) |
264 | return 0; | |
265 | last = list; | |
9efe50a4 | 266 | list = list->next; |
267 | } | |
268 | while (list); | |
83b23cdf | 269 | |
f6ab81c1 | 270 | if ((offset_out || ptr) && last && last->idx > 0) |
83b23cdf | 271 | { |
f6ab81c1 | 272 | unsigned HOST_WIDE_INT rel_off |
273 | = (unsigned HOST_WIDE_INT) off - last->offset; | |
83b23cdf | 274 | strinfo *si = get_strinfo (last->idx); |
f6ab81c1 | 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 | } | |
83b23cdf | 285 | } |
9efe50a4 | 286 | return 0; |
287 | } | |
288 | ||
289 | /* Return string index for EXP. */ | |
290 | ||
291 | static int | |
292 | get_stridx (tree exp) | |
293 | { | |
7c154220 | 294 | tree s, o; |
9efe50a4 | 295 | |
296 | if (TREE_CODE (exp) == SSA_NAME) | |
150a0f7d | 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 | { | |
42acab1c | 305 | gimple *def_stmt = SSA_NAME_DEF_STMT (e); |
150a0f7d | 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 | { | |
04009ada | 322 | strinfo *si |
150a0f7d | 323 | = get_strinfo (ssa_ver_to_stridx[SSA_NAME_VERSION (rhs1)]); |
f6ab81c1 | 324 | if (si && compare_nonzero_chars (si, off) >= 0) |
150a0f7d | 325 | return get_stridx_plus_constant (si, off, exp); |
326 | } | |
327 | e = rhs1; | |
328 | } | |
329 | return 0; | |
330 | } | |
9efe50a4 | 331 | |
332 | if (TREE_CODE (exp) == ADDR_EXPR) | |
333 | { | |
f6ab81c1 | 334 | int idx = get_addr_stridx (TREE_OPERAND (exp, 0), exp, NULL); |
9efe50a4 | 335 | if (idx != 0) |
336 | return idx; | |
337 | } | |
338 | ||
7c154220 | 339 | s = string_constant (exp, &o); |
340 | if (s != NULL_TREE | |
35ec552a | 341 | && (o == NULL_TREE || tree_fits_shwi_p (o)) |
7c154220 | 342 | && TREE_STRING_LENGTH (s) > 0) |
9efe50a4 | 343 | { |
fcb97e84 | 344 | HOST_WIDE_INT offset = o ? tree_to_shwi (o) : 0; |
7c154220 | 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); | |
9efe50a4 | 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 | { | |
f1f41a6c | 359 | return vec_safe_length (stridx_to_strinfo) |
360 | && (*stridx_to_strinfo)[0] != NULL; | |
9efe50a4 | 361 | } |
362 | ||
363 | /* Unshare strinfo vector that is shared with the immediate dominator. */ | |
364 | ||
365 | static void | |
366 | unshare_strinfo_vec (void) | |
367 | { | |
04009ada | 368 | strinfo *si; |
9efe50a4 | 369 | unsigned int i = 0; |
370 | ||
371 | gcc_assert (strinfo_shared ()); | |
f1f41a6c | 372 | stridx_to_strinfo = vec_safe_copy (stridx_to_strinfo); |
373 | for (i = 1; vec_safe_iterate (stridx_to_strinfo, i, &si); ++i) | |
9efe50a4 | 374 | if (si != NULL) |
375 | si->refcount++; | |
f1f41a6c | 376 | (*stridx_to_strinfo)[0] = NULL; |
9efe50a4 | 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 | { | |
9efe50a4 | 386 | HOST_WIDE_INT off; |
387 | ||
773078cb | 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)) | |
9efe50a4 | 391 | return NULL; |
392 | ||
c1f445d2 | 393 | if (!decl_to_stridxlist_htab) |
9efe50a4 | 394 | { |
d62dd039 | 395 | decl_to_stridxlist_htab |
ee34b0e4 | 396 | = new hash_map<tree_decl_hash, stridxlist> (64); |
9efe50a4 | 397 | gcc_obstack_init (&stridx_obstack); |
398 | } | |
d62dd039 | 399 | |
400 | bool existed; | |
401 | stridxlist *list = &decl_to_stridxlist_htab->get_or_insert (base, &existed); | |
402 | if (existed) | |
9efe50a4 | 403 | { |
404 | int i; | |
83b23cdf | 405 | stridxlist *before = NULL; |
406 | for (i = 0; i < 32; i++) | |
9efe50a4 | 407 | { |
408 | if (list->offset == off) | |
409 | return &list->idx; | |
83b23cdf | 410 | if (list->offset > off && before == NULL) |
411 | before = list; | |
9efe50a4 | 412 | if (list->next == NULL) |
413 | break; | |
83b23cdf | 414 | list = list->next; |
9efe50a4 | 415 | } |
83b23cdf | 416 | if (i == 32) |
9efe50a4 | 417 | return NULL; |
83b23cdf | 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 | } | |
9efe50a4 | 428 | list->next = XOBNEW (&stridx_obstack, struct stridxlist); |
429 | list = list->next; | |
430 | } | |
d62dd039 | 431 | |
9efe50a4 | 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++; | |
f1f41a6c | 451 | ssa_ver_to_stridx[SSA_NAME_VERSION (exp)] = idx; |
9efe50a4 | 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 | ||
04009ada | 487 | static strinfo * |
f6ab81c1 | 488 | new_strinfo (tree ptr, int idx, tree nonzero_chars, bool full_string_p) |
9efe50a4 | 489 | { |
04009ada | 490 | strinfo *si = strinfo_pool.allocate (); |
f6ab81c1 | 491 | si->nonzero_chars = nonzero_chars; |
9efe50a4 | 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; | |
f6ab81c1 | 502 | si->full_string_p = full_string_p; |
9efe50a4 | 503 | return si; |
504 | } | |
505 | ||
506 | /* Decrease strinfo refcount and free it if not referenced anymore. */ | |
507 | ||
508 | static inline void | |
04009ada | 509 | free_strinfo (strinfo *si) |
9efe50a4 | 510 | { |
511 | if (si && --si->refcount == 0) | |
a7e0cb97 | 512 | strinfo_pool.remove (si); |
9efe50a4 | 513 | } |
514 | ||
9efe50a4 | 515 | /* Set strinfo in the vector entry IDX to SI. */ |
516 | ||
517 | static inline void | |
04009ada | 518 | set_strinfo (int idx, strinfo *si) |
9efe50a4 | 519 | { |
f1f41a6c | 520 | if (vec_safe_length (stridx_to_strinfo) && (*stridx_to_strinfo)[0]) |
9efe50a4 | 521 | unshare_strinfo_vec (); |
f1f41a6c | 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; | |
9efe50a4 | 525 | } |
526 | ||
85690345 | 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); | |
f6ab81c1 | 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; | |
85690345 | 565 | } |
566 | ||
9efe50a4 | 567 | /* Return string length, or NULL if it can't be computed. */ |
568 | ||
569 | static tree | |
04009ada | 570 | get_string_length (strinfo *si) |
9efe50a4 | 571 | { |
f6ab81c1 | 572 | if (si->nonzero_chars) |
573 | return si->full_string_p ? si->nonzero_chars : NULL; | |
9efe50a4 | 574 | |
575 | if (si->stmt) | |
576 | { | |
42acab1c | 577 | gimple *stmt = si->stmt, *lenstmt; |
03d37e4e | 578 | tree callee, lhs, fn, tem; |
9efe50a4 | 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); | |
9efe50a4 | 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); | |
b9a16870 | 597 | fn = builtin_decl_implicit (BUILT_IN_STRLEN); |
9efe50a4 | 598 | gcc_assert (lhs == NULL_TREE); |
9efe50a4 | 599 | tem = unshare_expr (gimple_call_arg (stmt, 0)); |
1e42d5c6 | 600 | lenstmt = gimple_build_call (fn, 1, tem); |
03d37e4e | 601 | lhs = make_ssa_name (TREE_TYPE (TREE_TYPE (fn)), lenstmt); |
9efe50a4 | 602 | gimple_call_set_lhs (lenstmt, lhs); |
603 | gimple_set_vuse (lenstmt, gimple_vuse (stmt)); | |
604 | gsi_insert_before (&gsi, lenstmt, GSI_SAME_STMT); | |
9efe50a4 | 605 | tem = gimple_call_arg (stmt, 0); |
d1f1c0a9 | 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 | } | |
e9cf809e | 612 | lenstmt = gimple_build_assign |
613 | (make_ssa_name (TREE_TYPE (gimple_call_arg (stmt, 0))), | |
614 | POINTER_PLUS_EXPR,tem, lhs); | |
9efe50a4 | 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: | |
be27f1f5 | 620 | case BUILT_IN_STRCPY_CHK: |
618d4af2 | 621 | gcc_assert (builtin_decl_implicit_p (BUILT_IN_STPCPY)); |
be27f1f5 | 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); | |
9efe50a4 | 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); | |
03d37e4e | 633 | lhs = make_ssa_name (TREE_TYPE (TREE_TYPE (fn)), stmt); |
9efe50a4 | 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); | |
85690345 | 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)) | |
f6ab81c1 | 650 | if (chainsi->nonzero_chars == NULL) |
85690345 | 651 | set_endptr_and_length (loc, chainsi, lhs); |
9efe50a4 | 652 | break; |
9f15ed6e | 653 | case BUILT_IN_MALLOC: |
654 | break; | |
f6ab81c1 | 655 | /* BUILT_IN_CALLOC always has si->nonzero_chars set. */ |
9efe50a4 | 656 | default: |
657 | gcc_unreachable (); | |
658 | break; | |
659 | } | |
660 | } | |
661 | ||
f6ab81c1 | 662 | return si->nonzero_chars; |
9efe50a4 | 663 | } |
664 | ||
665 | /* Invalidate string length information for strings whose length | |
666 | might change due to stores in stmt. */ | |
667 | ||
668 | static bool | |
42acab1c | 669 | maybe_invalidate (gimple *stmt) |
9efe50a4 | 670 | { |
04009ada | 671 | strinfo *si; |
9efe50a4 | 672 | unsigned int i; |
673 | bool nonempty = false; | |
674 | ||
f1f41a6c | 675 | for (i = 1; vec_safe_iterate (stridx_to_strinfo, i, &si); ++i) |
9efe50a4 | 676 | if (si != NULL) |
677 | { | |
678 | if (!si->dont_invalidate) | |
679 | { | |
680 | ao_ref r; | |
f6ab81c1 | 681 | /* Do not use si->nonzero_chars. */ |
9efe50a4 | 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 | ||
150a0f7d | 696 | /* Unshare strinfo record SI, if it has refcount > 1 or |
9efe50a4 | 697 | if stridx_to_strinfo vector is shared with some other |
698 | bbs. */ | |
699 | ||
04009ada | 700 | static strinfo * |
701 | unshare_strinfo (strinfo *si) | |
9efe50a4 | 702 | { |
04009ada | 703 | strinfo *nsi; |
9efe50a4 | 704 | |
705 | if (si->refcount == 1 && !strinfo_shared ()) | |
706 | return si; | |
707 | ||
f6ab81c1 | 708 | nsi = new_strinfo (si->ptr, si->idx, si->nonzero_chars, si->full_string_p); |
9efe50a4 | 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 | ||
150a0f7d | 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 | |
f6ab81c1 | 725 | get_stridx_plus_constant (strinfo *basesi, unsigned HOST_WIDE_INT off, |
726 | tree ptr) | |
150a0f7d | 727 | { |
83b23cdf | 728 | if (TREE_CODE (ptr) == SSA_NAME && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ptr)) |
150a0f7d | 729 | return 0; |
730 | ||
f6ab81c1 | 731 | if (compare_nonzero_chars (basesi, off) < 0 |
732 | || !tree_fits_uhwi_p (basesi->nonzero_chars)) | |
150a0f7d | 733 | return 0; |
734 | ||
f6ab81c1 | 735 | unsigned HOST_WIDE_INT nonzero_chars |
736 | = tree_to_uhwi (basesi->nonzero_chars) - off; | |
04009ada | 737 | strinfo *si = basesi, *chainsi; |
150a0f7d | 738 | if (si->first || si->prev || si->next) |
739 | si = verify_related_strinfos (basesi); | |
740 | if (si == NULL | |
f6ab81c1 | 741 | || si->nonzero_chars == NULL_TREE |
742 | || TREE_CODE (si->nonzero_chars) != INTEGER_CST) | |
150a0f7d | 743 | return 0; |
744 | ||
83b23cdf | 745 | if (TREE_CODE (ptr) == SSA_NAME |
746 | && ssa_ver_to_stridx.length () <= SSA_NAME_VERSION (ptr)) | |
150a0f7d | 747 | ssa_ver_to_stridx.safe_grow_cleared (num_ssa_names); |
748 | ||
f6ab81c1 | 749 | gcc_checking_assert (compare_tree_int (si->nonzero_chars, off) != -1); |
150a0f7d | 750 | for (chainsi = si; chainsi->next; chainsi = si) |
751 | { | |
e4b21f53 | 752 | si = get_next_strinfo (chainsi); |
150a0f7d | 753 | if (si == NULL |
f6ab81c1 | 754 | || si->nonzero_chars == NULL_TREE |
755 | || TREE_CODE (si->nonzero_chars) != INTEGER_CST) | |
150a0f7d | 756 | break; |
f6ab81c1 | 757 | int r = compare_tree_int (si->nonzero_chars, nonzero_chars); |
150a0f7d | 758 | if (r != 1) |
759 | { | |
760 | if (r == 0) | |
761 | { | |
c54ee83c | 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 | } | |
150a0f7d | 770 | return si->idx; |
771 | } | |
772 | break; | |
773 | } | |
774 | } | |
775 | ||
776 | int idx = new_stridx (ptr); | |
777 | if (idx == 0) | |
778 | return 0; | |
f6ab81c1 | 779 | si = new_strinfo (ptr, idx, build_int_cst (size_type_node, nonzero_chars), |
780 | basesi->full_string_p); | |
150a0f7d | 781 | set_strinfo (idx, si); |
0317f6bd | 782 | if (strinfo *nextsi = get_strinfo (chainsi->next)) |
150a0f7d | 783 | { |
0317f6bd | 784 | nextsi = unshare_strinfo (nextsi); |
150a0f7d | 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; | |
f6ab81c1 | 792 | if (chainsi->endptr == NULL_TREE && zero_length_string_p (si)) |
150a0f7d | 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 | ||
9efe50a4 | 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 | ||
04009ada | 805 | static strinfo * |
806 | zero_length_string (tree ptr, strinfo *chainsi) | |
9efe50a4 | 807 | { |
04009ada | 808 | strinfo *si; |
9efe50a4 | 809 | int idx; |
150a0f7d | 810 | if (ssa_ver_to_stridx.length () <= SSA_NAME_VERSION (ptr)) |
811 | ssa_ver_to_stridx.safe_grow_cleared (num_ssa_names); | |
9efe50a4 | 812 | gcc_checking_assert (TREE_CODE (ptr) == SSA_NAME |
150a0f7d | 813 | && ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)] == 0); |
9efe50a4 | 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 | { | |
e4b21f53 | 822 | do |
9efe50a4 | 823 | { |
85690345 | 824 | /* We shouldn't mix delayed and non-delayed lengths. */ |
f6ab81c1 | 825 | gcc_assert (si->full_string_p); |
e4b21f53 | 826 | if (si->endptr == NULL_TREE) |
9efe50a4 | 827 | { |
e4b21f53 | 828 | si = unshare_strinfo (si); |
829 | si->endptr = ptr; | |
9efe50a4 | 830 | } |
e4b21f53 | 831 | chainsi = si; |
832 | si = get_next_strinfo (si); | |
9efe50a4 | 833 | } |
e4b21f53 | 834 | while (si != NULL); |
f6ab81c1 | 835 | if (zero_length_string_p (chainsi)) |
9efe50a4 | 836 | { |
837 | if (chainsi->next) | |
838 | { | |
839 | chainsi = unshare_strinfo (chainsi); | |
840 | chainsi->next = 0; | |
841 | } | |
f1f41a6c | 842 | ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)] = chainsi->idx; |
9efe50a4 | 843 | return chainsi; |
844 | } | |
845 | } | |
85690345 | 846 | else |
9efe50a4 | 847 | { |
85690345 | 848 | /* We shouldn't mix delayed and non-delayed lengths. */ |
f6ab81c1 | 849 | gcc_assert (chainsi->full_string_p); |
85690345 | 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 | } | |
9efe50a4 | 857 | } |
858 | } | |
859 | idx = new_stridx (ptr); | |
860 | if (idx == 0) | |
861 | return NULL; | |
f6ab81c1 | 862 | si = new_strinfo (ptr, idx, build_int_cst (size_type_node, 0), true); |
9efe50a4 | 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; | |
364de285 | 871 | if (chainsi->endptr == NULL_TREE) |
872 | chainsi->endptr = ptr; | |
9efe50a4 | 873 | si->prev = chainsi->idx; |
874 | si->first = chainsi->first; | |
875 | si->writable = chainsi->writable; | |
876 | } | |
877 | return si; | |
878 | } | |
879 | ||
f6ab81c1 | 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. */ | |
9efe50a4 | 885 | |
886 | static void | |
04009ada | 887 | adjust_related_strinfos (location_t loc, strinfo *origsi, tree adj) |
9efe50a4 | 888 | { |
04009ada | 889 | strinfo *si = verify_related_strinfos (origsi); |
9efe50a4 | 890 | |
891 | if (si == NULL) | |
892 | return; | |
893 | ||
894 | while (1) | |
895 | { | |
04009ada | 896 | strinfo *nsi; |
9efe50a4 | 897 | |
898 | if (si != origsi) | |
899 | { | |
900 | tree tem; | |
901 | ||
902 | si = unshare_strinfo (si); | |
85690345 | 903 | /* We shouldn't see delayed lengths here; the caller must have |
904 | calculated the old length in order to calculate the | |
905 | adjustment. */ | |
f6ab81c1 | 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; | |
364de285 | 912 | |
9efe50a4 | 913 | si->endptr = NULL_TREE; |
914 | si->dont_invalidate = true; | |
915 | } | |
e4b21f53 | 916 | nsi = get_next_strinfo (si); |
917 | if (nsi == NULL) | |
9efe50a4 | 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 | { | |
42acab1c | 934 | gimple *stmt = SSA_NAME_DEF_STMT (ptr); |
9efe50a4 | 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; | |
725879e5 | 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 */ | |
9efe50a4 | 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 | } | |
9efe50a4 | 957 | default: |
958 | return; | |
959 | } | |
960 | ||
961 | /* We might find an endptr created in this pass. Grow the | |
962 | vector in that case. */ | |
f1f41a6c | 963 | if (ssa_ver_to_stridx.length () <= SSA_NAME_VERSION (ptr)) |
964 | ssa_ver_to_stridx.safe_grow_cleared (num_ssa_names); | |
9efe50a4 | 965 | |
f1f41a6c | 966 | if (ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)] != 0) |
9efe50a4 | 967 | return; |
f1f41a6c | 968 | ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)] = idx; |
9efe50a4 | 969 | } |
970 | } | |
971 | ||
ec15ec36 | 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: | |
ec15ec36 | 988 | case BUILT_IN_STRLEN: |
ec15ec36 | 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: | |
ec15ec36 | 998 | case BUILT_IN_MEMPCPY: |
999 | case BUILT_IN_MEMPCPY_CHK: | |
ec15ec36 | 1000 | case BUILT_IN_MEMSET: |
1001 | case BUILT_IN_STPCPY: | |
1002 | case BUILT_IN_STPCPY_CHK: | |
ec15ec36 | 1003 | case BUILT_IN_STRCAT: |
1004 | case BUILT_IN_STRCAT_CHK: | |
ec15ec36 | 1005 | case BUILT_IN_STRCPY: |
1006 | case BUILT_IN_STRCPY_CHK: | |
ec15ec36 | 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 | ||
9efe50a4 | 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 | |
04009ada | 1027 | adjust_last_stmt (strinfo *si, gimple *stmt, bool is_strcat) |
9efe50a4 | 1028 | { |
1029 | tree vuse, callee, len; | |
1030 | struct laststmt_struct last = laststmt; | |
04009ada | 1031 | strinfo *lastsi, *firstsi; |
b719a128 | 1032 | unsigned len_arg_no = 2; |
9efe50a4 | 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 | { | |
e4b21f53 | 1062 | firstsi = get_next_strinfo (firstsi); |
1063 | if (firstsi == NULL) | |
9efe50a4 | 1064 | return; |
9efe50a4 | 1065 | } |
1066 | } | |
1067 | ||
f6ab81c1 | 1068 | if (!is_strcat && !zero_length_string_p (si)) |
1069 | return; | |
9efe50a4 | 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 | ||
ec15ec36 | 1086 | if (!valid_builtin_call (last.stmt)) |
9efe50a4 | 1087 | return; |
1088 | ||
789a8d72 | 1089 | callee = gimple_call_fndecl (last.stmt); |
9efe50a4 | 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 | ||
b719a128 | 1099 | len = gimple_call_arg (last.stmt, len_arg_no); |
cd4547bf | 1100 | if (tree_fits_uhwi_p (len)) |
9efe50a4 | 1101 | { |
cd4547bf | 1102 | if (!tree_fits_uhwi_p (last.len) |
9efe50a4 | 1103 | || integer_zerop (len) |
aa59f000 | 1104 | || tree_to_uhwi (len) != tree_to_uhwi (last.len) + 1) |
9efe50a4 | 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. */ | |
aa59f000 | 1108 | if ((tree_to_uhwi (len) & 3) == 0) |
9efe50a4 | 1109 | return; |
1110 | } | |
1111 | else if (TREE_CODE (len) == SSA_NAME) | |
1112 | { | |
42acab1c | 1113 | gimple *def_stmt = SSA_NAME_DEF_STMT (len); |
9efe50a4 | 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 | ||
b719a128 | 1123 | gimple_call_set_arg (last.stmt, len_arg_no, last.len); |
9efe50a4 | 1124 | update_stmt (last.stmt); |
1125 | } | |
1126 | ||
2a59bca6 | 1127 | /* For an LHS that is an SSA_NAME and for strlen() argument SRC, set |
1128 | LHS range info to [0, N] if SRC refers to a character array A[N] | |
1129 | with unknown length bounded by N. */ | |
1130 | ||
1131 | static void | |
1132 | maybe_set_strlen_range (tree lhs, tree src) | |
1133 | { | |
1134 | if (TREE_CODE (lhs) != SSA_NAME) | |
1135 | return; | |
1136 | ||
1137 | if (TREE_CODE (src) == SSA_NAME) | |
1138 | { | |
1139 | gimple *def = SSA_NAME_DEF_STMT (src); | |
1140 | if (is_gimple_assign (def) | |
1141 | && gimple_assign_rhs_code (def) == ADDR_EXPR) | |
1142 | src = gimple_assign_rhs1 (def); | |
1143 | } | |
1144 | ||
1145 | if (TREE_CODE (src) != ADDR_EXPR) | |
1146 | return; | |
1147 | ||
1148 | /* The last array member of a struct can be bigger than its size | |
1149 | suggests if it's treated as a poor-man's flexible array member. */ | |
1150 | src = TREE_OPERAND (src, 0); | |
1151 | if (TREE_CODE (TREE_TYPE (src)) != ARRAY_TYPE | |
1152 | || array_at_struct_end_p (src)) | |
1153 | return; | |
1154 | ||
1155 | tree type = TREE_TYPE (src); | |
1156 | if (tree dom = TYPE_DOMAIN (type)) | |
1157 | if (tree maxval = TYPE_MAX_VALUE (dom)) | |
1158 | { | |
1159 | wide_int max = wi::to_wide (maxval); | |
1160 | wide_int min = wi::zero (max.get_precision ()); | |
1161 | set_range_info (lhs, VR_RANGE, min, max); | |
1162 | } | |
1163 | } | |
1164 | ||
9efe50a4 | 1165 | /* Handle a strlen call. If strlen of the argument is known, replace |
1166 | the strlen call with the known value, otherwise remember that strlen | |
1167 | of the argument is stored in the lhs SSA_NAME. */ | |
1168 | ||
1169 | static void | |
1170 | handle_builtin_strlen (gimple_stmt_iterator *gsi) | |
1171 | { | |
1172 | int idx; | |
1173 | tree src; | |
42acab1c | 1174 | gimple *stmt = gsi_stmt (*gsi); |
9efe50a4 | 1175 | tree lhs = gimple_call_lhs (stmt); |
1176 | ||
1177 | if (lhs == NULL_TREE) | |
1178 | return; | |
1179 | ||
1180 | src = gimple_call_arg (stmt, 0); | |
1181 | idx = get_stridx (src); | |
1182 | if (idx) | |
1183 | { | |
04009ada | 1184 | strinfo *si = NULL; |
9efe50a4 | 1185 | tree rhs; |
1186 | ||
1187 | if (idx < 0) | |
1188 | rhs = build_int_cst (TREE_TYPE (lhs), ~idx); | |
1189 | else | |
1190 | { | |
1191 | rhs = NULL_TREE; | |
1192 | si = get_strinfo (idx); | |
1193 | if (si != NULL) | |
1194 | rhs = get_string_length (si); | |
1195 | } | |
1196 | if (rhs != NULL_TREE) | |
1197 | { | |
1198 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1199 | { | |
1200 | fprintf (dump_file, "Optimizing: "); | |
1201 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
1202 | } | |
1203 | rhs = unshare_expr (rhs); | |
1204 | if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs))) | |
1205 | rhs = fold_convert_loc (gimple_location (stmt), | |
1206 | TREE_TYPE (lhs), rhs); | |
1207 | if (!update_call_from_tree (gsi, rhs)) | |
1208 | gimplify_and_update_call_from_tree (gsi, rhs); | |
1209 | stmt = gsi_stmt (*gsi); | |
1210 | update_stmt (stmt); | |
1211 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1212 | { | |
1213 | fprintf (dump_file, "into: "); | |
1214 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
1215 | } | |
1216 | if (si != NULL | |
f6ab81c1 | 1217 | && TREE_CODE (si->nonzero_chars) != SSA_NAME |
1218 | && TREE_CODE (si->nonzero_chars) != INTEGER_CST | |
9efe50a4 | 1219 | && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) |
1220 | { | |
1221 | si = unshare_strinfo (si); | |
f6ab81c1 | 1222 | si->nonzero_chars = lhs; |
1223 | gcc_assert (si->full_string_p); | |
9efe50a4 | 1224 | } |
d8aad786 | 1225 | |
0c45740b | 1226 | if (strlen_to_stridx) |
1227 | { | |
1228 | location_t loc = gimple_location (stmt); | |
1229 | strlen_to_stridx->put (lhs, stridx_strlenloc (idx, loc)); | |
1230 | } | |
9efe50a4 | 1231 | return; |
1232 | } | |
1233 | } | |
1234 | if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) | |
1235 | return; | |
1236 | if (idx == 0) | |
1237 | idx = new_stridx (src); | |
f6ab81c1 | 1238 | else |
1239 | { | |
1240 | strinfo *si = get_strinfo (idx); | |
1241 | if (si != NULL) | |
1242 | { | |
1243 | if (!si->full_string_p && !si->stmt) | |
1244 | { | |
1245 | /* Until now we only had a lower bound on the string length. | |
1246 | Install LHS as the actual length. */ | |
1247 | si = unshare_strinfo (si); | |
e6f1ccb6 | 1248 | tree old = si->nonzero_chars; |
f6ab81c1 | 1249 | si->nonzero_chars = lhs; |
1250 | si->full_string_p = true; | |
e6f1ccb6 | 1251 | if (TREE_CODE (old) == INTEGER_CST) |
1252 | { | |
1253 | location_t loc = gimple_location (stmt); | |
1254 | old = fold_convert_loc (loc, TREE_TYPE (lhs), old); | |
1255 | tree adj = fold_build2_loc (loc, MINUS_EXPR, | |
1256 | TREE_TYPE (lhs), lhs, old); | |
1257 | adjust_related_strinfos (loc, si, adj); | |
1258 | } | |
1259 | else | |
1260 | { | |
1261 | si->first = 0; | |
1262 | si->prev = 0; | |
1263 | si->next = 0; | |
1264 | } | |
f6ab81c1 | 1265 | } |
1266 | return; | |
1267 | } | |
1268 | } | |
9efe50a4 | 1269 | if (idx) |
1270 | { | |
f6ab81c1 | 1271 | strinfo *si = new_strinfo (src, idx, lhs, true); |
9efe50a4 | 1272 | set_strinfo (idx, si); |
1273 | find_equal_ptrs (src, idx); | |
d8aad786 | 1274 | |
2a59bca6 | 1275 | /* For SRC that is an array of N elements, set LHS's range |
1276 | to [0, N]. */ | |
1277 | maybe_set_strlen_range (lhs, src); | |
1278 | ||
0c45740b | 1279 | if (strlen_to_stridx) |
1280 | { | |
1281 | location_t loc = gimple_location (stmt); | |
1282 | strlen_to_stridx->put (lhs, stridx_strlenloc (idx, loc)); | |
1283 | } | |
9efe50a4 | 1284 | } |
1285 | } | |
1286 | ||
1287 | /* Handle a strchr call. If strlen of the first argument is known, replace | |
1288 | the strchr (x, 0) call with the endptr or x + strlen, otherwise remember | |
1289 | that lhs of the call is endptr and strlen of the argument is endptr - x. */ | |
1290 | ||
1291 | static void | |
1292 | handle_builtin_strchr (gimple_stmt_iterator *gsi) | |
1293 | { | |
1294 | int idx; | |
1295 | tree src; | |
42acab1c | 1296 | gimple *stmt = gsi_stmt (*gsi); |
9efe50a4 | 1297 | tree lhs = gimple_call_lhs (stmt); |
1298 | ||
1299 | if (lhs == NULL_TREE) | |
1300 | return; | |
1301 | ||
1e42d5c6 | 1302 | if (!integer_zerop (gimple_call_arg (stmt, 1))) |
9efe50a4 | 1303 | return; |
1304 | ||
1305 | src = gimple_call_arg (stmt, 0); | |
1306 | idx = get_stridx (src); | |
1307 | if (idx) | |
1308 | { | |
04009ada | 1309 | strinfo *si = NULL; |
9efe50a4 | 1310 | tree rhs; |
1311 | ||
1312 | if (idx < 0) | |
1313 | rhs = build_int_cst (size_type_node, ~idx); | |
1314 | else | |
1315 | { | |
1316 | rhs = NULL_TREE; | |
1317 | si = get_strinfo (idx); | |
1318 | if (si != NULL) | |
1319 | rhs = get_string_length (si); | |
1320 | } | |
1321 | if (rhs != NULL_TREE) | |
1322 | { | |
1323 | location_t loc = gimple_location (stmt); | |
1324 | ||
1325 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1326 | { | |
1327 | fprintf (dump_file, "Optimizing: "); | |
1328 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
1329 | } | |
1330 | if (si != NULL && si->endptr != NULL_TREE) | |
1331 | { | |
1332 | rhs = unshare_expr (si->endptr); | |
1333 | if (!useless_type_conversion_p (TREE_TYPE (lhs), | |
1334 | TREE_TYPE (rhs))) | |
1335 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); | |
1336 | } | |
1337 | else | |
1338 | { | |
1339 | rhs = fold_convert_loc (loc, sizetype, unshare_expr (rhs)); | |
1340 | rhs = fold_build2_loc (loc, POINTER_PLUS_EXPR, | |
1341 | TREE_TYPE (src), src, rhs); | |
1342 | if (!useless_type_conversion_p (TREE_TYPE (lhs), | |
1343 | TREE_TYPE (rhs))) | |
1344 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); | |
1345 | } | |
1346 | if (!update_call_from_tree (gsi, rhs)) | |
1347 | gimplify_and_update_call_from_tree (gsi, rhs); | |
1348 | stmt = gsi_stmt (*gsi); | |
1349 | update_stmt (stmt); | |
1350 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1351 | { | |
1352 | fprintf (dump_file, "into: "); | |
1353 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
1354 | } | |
1355 | if (si != NULL | |
1356 | && si->endptr == NULL_TREE | |
1357 | && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) | |
1358 | { | |
1359 | si = unshare_strinfo (si); | |
1360 | si->endptr = lhs; | |
1361 | } | |
1362 | zero_length_string (lhs, si); | |
1363 | return; | |
1364 | } | |
1365 | } | |
1366 | if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) | |
1367 | return; | |
1368 | if (TREE_CODE (src) != SSA_NAME || !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (src)) | |
1369 | { | |
1370 | if (idx == 0) | |
1371 | idx = new_stridx (src); | |
1372 | else if (get_strinfo (idx) != NULL) | |
1373 | { | |
1374 | zero_length_string (lhs, NULL); | |
1375 | return; | |
1376 | } | |
1377 | if (idx) | |
1378 | { | |
1379 | location_t loc = gimple_location (stmt); | |
1380 | tree lhsu = fold_convert_loc (loc, size_type_node, lhs); | |
1381 | tree srcu = fold_convert_loc (loc, size_type_node, src); | |
1382 | tree length = fold_build2_loc (loc, MINUS_EXPR, | |
1383 | size_type_node, lhsu, srcu); | |
f6ab81c1 | 1384 | strinfo *si = new_strinfo (src, idx, length, true); |
9efe50a4 | 1385 | si->endptr = lhs; |
1386 | set_strinfo (idx, si); | |
1387 | find_equal_ptrs (src, idx); | |
1388 | zero_length_string (lhs, si); | |
1389 | } | |
1390 | } | |
1391 | else | |
1392 | zero_length_string (lhs, NULL); | |
1393 | } | |
1394 | ||
1395 | /* Handle a strcpy-like ({st{r,p}cpy,__st{r,p}cpy_chk}) call. | |
1396 | If strlen of the second argument is known, strlen of the first argument | |
1397 | is the same after this call. Furthermore, attempt to convert it to | |
1398 | memcpy. */ | |
1399 | ||
1400 | static void | |
1401 | handle_builtin_strcpy (enum built_in_function bcode, gimple_stmt_iterator *gsi) | |
1402 | { | |
1403 | int idx, didx; | |
e6a18b5a | 1404 | tree src, dst, srclen, len, lhs, type, fn, oldlen; |
9efe50a4 | 1405 | bool success; |
42acab1c | 1406 | gimple *stmt = gsi_stmt (*gsi); |
04009ada | 1407 | strinfo *si, *dsi, *olddsi, *zsi; |
9efe50a4 | 1408 | location_t loc; |
1409 | ||
1e42d5c6 | 1410 | src = gimple_call_arg (stmt, 1); |
9efe50a4 | 1411 | dst = gimple_call_arg (stmt, 0); |
1412 | lhs = gimple_call_lhs (stmt); | |
1413 | idx = get_stridx (src); | |
1414 | si = NULL; | |
1415 | if (idx > 0) | |
1416 | si = get_strinfo (idx); | |
1417 | ||
1418 | didx = get_stridx (dst); | |
1419 | olddsi = NULL; | |
1420 | oldlen = NULL_TREE; | |
1421 | if (didx > 0) | |
1422 | olddsi = get_strinfo (didx); | |
1423 | else if (didx < 0) | |
1424 | return; | |
1425 | ||
1426 | if (olddsi != NULL) | |
1427 | adjust_last_stmt (olddsi, stmt, false); | |
1428 | ||
1429 | srclen = NULL_TREE; | |
1430 | if (si != NULL) | |
1431 | srclen = get_string_length (si); | |
1432 | else if (idx < 0) | |
1433 | srclen = build_int_cst (size_type_node, ~idx); | |
1434 | ||
1435 | loc = gimple_location (stmt); | |
1436 | if (srclen == NULL_TREE) | |
1437 | switch (bcode) | |
1438 | { | |
1439 | case BUILT_IN_STRCPY: | |
1440 | case BUILT_IN_STRCPY_CHK: | |
b9a16870 | 1441 | if (lhs != NULL_TREE || !builtin_decl_implicit_p (BUILT_IN_STPCPY)) |
9efe50a4 | 1442 | return; |
1443 | break; | |
1444 | case BUILT_IN_STPCPY: | |
1445 | case BUILT_IN_STPCPY_CHK: | |
1446 | if (lhs == NULL_TREE) | |
1447 | return; | |
1448 | else | |
1449 | { | |
1450 | tree lhsuint = fold_convert_loc (loc, size_type_node, lhs); | |
1451 | srclen = fold_convert_loc (loc, size_type_node, dst); | |
1452 | srclen = fold_build2_loc (loc, MINUS_EXPR, size_type_node, | |
1453 | lhsuint, srclen); | |
1454 | } | |
1455 | break; | |
1456 | default: | |
1457 | gcc_unreachable (); | |
1458 | } | |
1459 | ||
1460 | if (didx == 0) | |
1461 | { | |
1462 | didx = new_stridx (dst); | |
1463 | if (didx == 0) | |
1464 | return; | |
1465 | } | |
1466 | if (olddsi != NULL) | |
1467 | { | |
f6ab81c1 | 1468 | oldlen = olddsi->nonzero_chars; |
9efe50a4 | 1469 | dsi = unshare_strinfo (olddsi); |
f6ab81c1 | 1470 | dsi->nonzero_chars = srclen; |
1471 | dsi->full_string_p = (srclen != NULL_TREE); | |
9efe50a4 | 1472 | /* Break the chain, so adjust_related_strinfo on later pointers in |
1473 | the chain won't adjust this one anymore. */ | |
1474 | dsi->next = 0; | |
1475 | dsi->stmt = NULL; | |
1476 | dsi->endptr = NULL_TREE; | |
1477 | } | |
1478 | else | |
1479 | { | |
f6ab81c1 | 1480 | dsi = new_strinfo (dst, didx, srclen, srclen != NULL_TREE); |
9efe50a4 | 1481 | set_strinfo (didx, dsi); |
1482 | find_equal_ptrs (dst, didx); | |
1483 | } | |
1484 | dsi->writable = true; | |
1485 | dsi->dont_invalidate = true; | |
1486 | ||
f6ab81c1 | 1487 | if (dsi->nonzero_chars == NULL_TREE) |
9efe50a4 | 1488 | { |
04009ada | 1489 | strinfo *chainsi; |
364de285 | 1490 | |
9efe50a4 | 1491 | /* If string length of src is unknown, use delayed length |
1492 | computation. If string lenth of dst will be needed, it | |
1493 | can be computed by transforming this strcpy call into | |
1494 | stpcpy and subtracting dst from the return value. */ | |
364de285 | 1495 | |
1496 | /* Look for earlier strings whose length could be determined if | |
1497 | this strcpy is turned into an stpcpy. */ | |
1498 | ||
1499 | if (dsi->prev != 0 && (chainsi = verify_related_strinfos (dsi)) != NULL) | |
1500 | { | |
1501 | for (; chainsi && chainsi != dsi; chainsi = get_strinfo (chainsi->next)) | |
1502 | { | |
1503 | /* When setting a stmt for delayed length computation | |
1504 | prevent all strinfos through dsi from being | |
1505 | invalidated. */ | |
1506 | chainsi = unshare_strinfo (chainsi); | |
1507 | chainsi->stmt = stmt; | |
f6ab81c1 | 1508 | chainsi->nonzero_chars = NULL_TREE; |
1509 | chainsi->full_string_p = false; | |
364de285 | 1510 | chainsi->endptr = NULL_TREE; |
1511 | chainsi->dont_invalidate = true; | |
1512 | } | |
1513 | } | |
9efe50a4 | 1514 | dsi->stmt = stmt; |
e6a18b5a | 1515 | |
1516 | /* Try to detect overlap before returning. This catches cases | |
1517 | like strcpy (d, d + n) where n is non-constant whose range | |
1518 | is such that (n <= strlen (d) holds). | |
1519 | ||
1520 | OLDDSI->NONZERO_chars may have been reset by this point with | |
1521 | oldlen holding it original value. */ | |
1522 | if (olddsi && oldlen) | |
1523 | { | |
1524 | /* Add 1 for the terminating NUL. */ | |
1525 | tree type = TREE_TYPE (oldlen); | |
1526 | oldlen = fold_build2 (PLUS_EXPR, type, oldlen, | |
1527 | build_int_cst (type, 1)); | |
1528 | check_bounds_or_overlap (as_a <gcall *>(stmt), olddsi->ptr, src, | |
1529 | oldlen, NULL_TREE); | |
1530 | } | |
1531 | ||
9efe50a4 | 1532 | return; |
1533 | } | |
1534 | ||
1535 | if (olddsi != NULL) | |
1536 | { | |
1537 | tree adj = NULL_TREE; | |
1538 | if (oldlen == NULL_TREE) | |
1539 | ; | |
1540 | else if (integer_zerop (oldlen)) | |
1541 | adj = srclen; | |
1542 | else if (TREE_CODE (oldlen) == INTEGER_CST | |
1543 | || TREE_CODE (srclen) == INTEGER_CST) | |
1544 | adj = fold_build2_loc (loc, MINUS_EXPR, | |
1545 | TREE_TYPE (srclen), srclen, | |
1546 | fold_convert_loc (loc, TREE_TYPE (srclen), | |
1547 | oldlen)); | |
1548 | if (adj != NULL_TREE) | |
1549 | adjust_related_strinfos (loc, dsi, adj); | |
1550 | else | |
1551 | dsi->prev = 0; | |
1552 | } | |
1553 | /* strcpy src may not overlap dst, so src doesn't need to be | |
1554 | invalidated either. */ | |
1555 | if (si != NULL) | |
1556 | si->dont_invalidate = true; | |
1557 | ||
1558 | fn = NULL_TREE; | |
1559 | zsi = NULL; | |
1560 | switch (bcode) | |
1561 | { | |
1562 | case BUILT_IN_STRCPY: | |
b9a16870 | 1563 | fn = builtin_decl_implicit (BUILT_IN_MEMCPY); |
9efe50a4 | 1564 | if (lhs) |
f1f41a6c | 1565 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] = didx; |
9efe50a4 | 1566 | break; |
1567 | case BUILT_IN_STRCPY_CHK: | |
b9a16870 | 1568 | fn = builtin_decl_explicit (BUILT_IN_MEMCPY_CHK); |
9efe50a4 | 1569 | if (lhs) |
f1f41a6c | 1570 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] = didx; |
9efe50a4 | 1571 | break; |
1572 | case BUILT_IN_STPCPY: | |
1573 | /* This would need adjustment of the lhs (subtract one), | |
1574 | or detection that the trailing '\0' doesn't need to be | |
1575 | written, if it will be immediately overwritten. | |
b9a16870 | 1576 | fn = builtin_decl_explicit (BUILT_IN_MEMPCPY); */ |
9efe50a4 | 1577 | if (lhs) |
1578 | { | |
1579 | dsi->endptr = lhs; | |
1580 | zsi = zero_length_string (lhs, dsi); | |
1581 | } | |
1582 | break; | |
1583 | case BUILT_IN_STPCPY_CHK: | |
1584 | /* This would need adjustment of the lhs (subtract one), | |
1585 | or detection that the trailing '\0' doesn't need to be | |
1586 | written, if it will be immediately overwritten. | |
b9a16870 | 1587 | fn = builtin_decl_explicit (BUILT_IN_MEMPCPY_CHK); */ |
9efe50a4 | 1588 | if (lhs) |
1589 | { | |
1590 | dsi->endptr = lhs; | |
1591 | zsi = zero_length_string (lhs, dsi); | |
1592 | } | |
1593 | break; | |
1594 | default: | |
1595 | gcc_unreachable (); | |
1596 | } | |
1597 | if (zsi != NULL) | |
1598 | zsi->dont_invalidate = true; | |
1599 | ||
e6a18b5a | 1600 | if (fn) |
1601 | { | |
1602 | tree args = TYPE_ARG_TYPES (TREE_TYPE (fn)); | |
1603 | type = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (args))); | |
1604 | } | |
1605 | else | |
1606 | type = size_type_node; | |
9efe50a4 | 1607 | |
1608 | len = fold_convert_loc (loc, type, unshare_expr (srclen)); | |
1609 | len = fold_build2_loc (loc, PLUS_EXPR, type, len, build_int_cst (type, 1)); | |
e6a18b5a | 1610 | |
1611 | /* Set the no-warning bit on the transformed statement? */ | |
1612 | bool set_no_warning = false; | |
1613 | ||
1614 | if (const strinfo *chksi = olddsi ? olddsi : dsi) | |
1615 | if (si | |
1616 | && !check_bounds_or_overlap (as_a <gcall *>(stmt), chksi->ptr, si->ptr, | |
1617 | NULL_TREE, len)) | |
1618 | { | |
1619 | gimple_set_no_warning (stmt, true); | |
1620 | set_no_warning = true; | |
1621 | } | |
1622 | ||
1623 | if (fn == NULL_TREE) | |
1624 | return; | |
1625 | ||
9efe50a4 | 1626 | len = force_gimple_operand_gsi (gsi, len, true, NULL_TREE, true, |
1627 | GSI_SAME_STMT); | |
1628 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1629 | { | |
1630 | fprintf (dump_file, "Optimizing: "); | |
1631 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
1632 | } | |
1e42d5c6 | 1633 | if (gimple_call_num_args (stmt) == 2) |
1634 | success = update_gimple_call (gsi, fn, 3, dst, src, len); | |
9efe50a4 | 1635 | else |
1e42d5c6 | 1636 | success = update_gimple_call (gsi, fn, 4, dst, src, len, |
1637 | gimple_call_arg (stmt, 2)); | |
9efe50a4 | 1638 | if (success) |
1639 | { | |
1640 | stmt = gsi_stmt (*gsi); | |
1641 | update_stmt (stmt); | |
1642 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1643 | { | |
1644 | fprintf (dump_file, "into: "); | |
1645 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
1646 | } | |
1647 | /* Allow adjust_last_stmt to decrease this memcpy's size. */ | |
1648 | laststmt.stmt = stmt; | |
1649 | laststmt.len = srclen; | |
1650 | laststmt.stridx = dsi->idx; | |
1651 | } | |
1652 | else if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
1653 | fprintf (dump_file, "not possible.\n"); | |
e6a18b5a | 1654 | |
1655 | if (set_no_warning) | |
1656 | gimple_set_no_warning (stmt, true); | |
1657 | } | |
1658 | ||
1659 | /* Check the size argument to the built-in forms of stpncpy and strncpy | |
1660 | for out-of-bounds offsets or overlapping access, and to see if the | |
1661 | size argument is derived from a call to strlen() on the source argument, | |
1662 | and if so, issue an appropriate warning. */ | |
1663 | ||
1664 | static void | |
1665 | handle_builtin_strncat (built_in_function bcode, gimple_stmt_iterator *gsi) | |
1666 | { | |
1667 | /* Same as stxncpy(). */ | |
1668 | handle_builtin_stxncpy (bcode, gsi); | |
9efe50a4 | 1669 | } |
1670 | ||
d8aad786 | 1671 | /* Return true if LEN depends on a call to strlen(SRC) in an interesting |
1672 | way. LEN can either be an integer expression, or a pointer (to char). | |
1673 | When it is the latter (such as in recursive calls to self) is is | |
1674 | assumed to be the argument in some call to strlen() whose relationship | |
1675 | to SRC is being ascertained. */ | |
1676 | ||
1677 | static bool | |
1678 | is_strlen_related_p (tree src, tree len) | |
1679 | { | |
1680 | if (TREE_CODE (TREE_TYPE (len)) == POINTER_TYPE | |
1681 | && operand_equal_p (src, len, 0)) | |
1682 | return true; | |
1683 | ||
1684 | if (TREE_CODE (len) != SSA_NAME) | |
1685 | return false; | |
1686 | ||
1687 | gimple *def_stmt = SSA_NAME_DEF_STMT (len); | |
1688 | if (!def_stmt) | |
1689 | return false; | |
1690 | ||
1691 | if (is_gimple_call (def_stmt)) | |
1692 | { | |
1693 | tree func = gimple_call_fndecl (def_stmt); | |
1694 | if (!valid_builtin_call (def_stmt) | |
1695 | || DECL_FUNCTION_CODE (func) != BUILT_IN_STRLEN) | |
1696 | return false; | |
1697 | ||
1698 | tree arg = gimple_call_arg (def_stmt, 0); | |
1699 | return is_strlen_related_p (src, arg); | |
1700 | } | |
1701 | ||
1702 | if (!is_gimple_assign (def_stmt)) | |
1703 | return false; | |
1704 | ||
1705 | tree_code code = gimple_assign_rhs_code (def_stmt); | |
1706 | tree rhs1 = gimple_assign_rhs1 (def_stmt); | |
1707 | tree rhstype = TREE_TYPE (rhs1); | |
1708 | ||
1709 | if ((TREE_CODE (rhstype) == POINTER_TYPE && code == POINTER_PLUS_EXPR) | |
1710 | || (INTEGRAL_TYPE_P (rhstype) | |
1711 | && (code == BIT_AND_EXPR | |
1712 | || code == NOP_EXPR))) | |
1713 | { | |
1714 | /* Pointer plus (an integer) and integer cast or truncation are | |
1715 | considered among the (potentially) related expressions to strlen. | |
1716 | Others are not. */ | |
1717 | return is_strlen_related_p (src, rhs1); | |
1718 | } | |
1719 | ||
1720 | return false; | |
1721 | } | |
1722 | ||
bcb285a0 | 1723 | /* Called by handle_builtin_stxncpy and by gimple_fold_builtin_strncpy |
1724 | in gimple-fold.c. | |
1725 | Check to see if the specified bound is a) equal to the size of | |
1726 | the destination DST and if so, b) if it's immediately followed by | |
1727 | DST[CNT - 1] = '\0'. If a) holds and b) does not, warn. Otherwise, | |
1728 | do nothing. Return true if diagnostic has been issued. | |
d8aad786 | 1729 | |
1730 | The purpose is to diagnose calls to strncpy and stpncpy that do | |
1731 | not nul-terminate the copy while allowing for the idiom where | |
1732 | such a call is immediately followed by setting the last element | |
1733 | to nul, as in: | |
1734 | char a[32]; | |
1735 | strncpy (a, s, sizeof a); | |
1736 | a[sizeof a - 1] = '\0'; | |
1737 | */ | |
1738 | ||
bcb285a0 | 1739 | bool |
d8aad786 | 1740 | maybe_diag_stxncpy_trunc (gimple_stmt_iterator gsi, tree src, tree cnt) |
1741 | { | |
d8aad786 | 1742 | gimple *stmt = gsi_stmt (gsi); |
75e9093e | 1743 | if (gimple_no_warning_p (stmt)) |
1744 | return false; | |
d8aad786 | 1745 | |
1746 | wide_int cntrange[2]; | |
1747 | ||
1748 | if (TREE_CODE (cnt) == INTEGER_CST) | |
1749 | cntrange[0] = cntrange[1] = wi::to_wide (cnt); | |
1750 | else if (TREE_CODE (cnt) == SSA_NAME) | |
1751 | { | |
1752 | enum value_range_type rng = get_range_info (cnt, cntrange, cntrange + 1); | |
1753 | if (rng == VR_RANGE) | |
1754 | ; | |
1755 | else if (rng == VR_ANTI_RANGE) | |
1756 | { | |
1757 | wide_int maxobjsize = wi::to_wide (TYPE_MAX_VALUE (ptrdiff_type_node)); | |
1758 | ||
1759 | if (wi::ltu_p (cntrange[1], maxobjsize)) | |
1760 | { | |
1761 | cntrange[0] = cntrange[1] + 1; | |
1762 | cntrange[1] = maxobjsize; | |
1763 | } | |
1764 | else | |
1765 | { | |
1766 | cntrange[1] = cntrange[0] - 1; | |
1767 | cntrange[0] = wi::zero (TYPE_PRECISION (TREE_TYPE (cnt))); | |
1768 | } | |
1769 | } | |
1770 | else | |
1771 | return false; | |
1772 | } | |
1773 | else | |
1774 | return false; | |
1775 | ||
1776 | /* Negative value is the constant string length. If it's less than | |
bcb285a0 | 1777 | the lower bound there is no truncation. Avoid calling get_stridx() |
1778 | when ssa_ver_to_stridx is empty. That implies the caller isn't | |
1779 | running under the control of this pass and ssa_ver_to_stridx hasn't | |
1780 | been created yet. */ | |
1781 | int sidx = ssa_ver_to_stridx.length () ? get_stridx (src) : 0; | |
d8aad786 | 1782 | if (sidx < 0 && wi::gtu_p (cntrange[0], ~sidx)) |
1783 | return false; | |
1784 | ||
1785 | tree dst = gimple_call_arg (stmt, 0); | |
d8aad786 | 1786 | tree dstdecl = dst; |
1787 | if (TREE_CODE (dstdecl) == ADDR_EXPR) | |
1788 | dstdecl = TREE_OPERAND (dstdecl, 0); | |
1789 | ||
0c45740b | 1790 | /* If the destination refers to a an array/pointer declared nonstring |
1791 | return early. */ | |
1792 | tree ref = NULL_TREE; | |
1793 | if (get_attr_nonstring_decl (dstdecl, &ref)) | |
1794 | return false; | |
d8aad786 | 1795 | |
1796 | /* Look for dst[i] = '\0'; after the stxncpy() call and if found | |
1797 | avoid the truncation warning. */ | |
fac38b8b | 1798 | gsi_next_nondebug (&gsi); |
d8aad786 | 1799 | gimple *next_stmt = gsi_stmt (gsi); |
dc4a43f2 | 1800 | if (!next_stmt) |
1801 | { | |
1802 | /* When there is no statement in the same basic block check | |
1803 | the immediate successor block. */ | |
1804 | if (basic_block bb = gimple_bb (stmt)) | |
1805 | { | |
1806 | if (single_succ_p (bb)) | |
1807 | { | |
1808 | /* For simplicity, ignore blocks with multiple outgoing | |
1809 | edges for now and only consider successor blocks along | |
1810 | normal edges. */ | |
1811 | edge e = EDGE_SUCC (bb, 0); | |
1812 | if (!(e->flags & EDGE_ABNORMAL)) | |
1813 | { | |
1814 | gsi = gsi_start_bb (e->dest); | |
1815 | next_stmt = gsi_stmt (gsi); | |
1816 | if (next_stmt && is_gimple_debug (next_stmt)) | |
1817 | { | |
1818 | gsi_next_nondebug (&gsi); | |
1819 | next_stmt = gsi_stmt (gsi); | |
1820 | } | |
1821 | } | |
1822 | } | |
1823 | } | |
1824 | } | |
d8aad786 | 1825 | |
dc4a43f2 | 1826 | if (next_stmt && is_gimple_assign (next_stmt)) |
d8aad786 | 1827 | { |
d8aad786 | 1828 | tree lhs = gimple_assign_lhs (next_stmt); |
0c45740b | 1829 | tree_code code = TREE_CODE (lhs); |
1830 | if (code == ARRAY_REF || code == MEM_REF) | |
1831 | lhs = TREE_OPERAND (lhs, 0); | |
1832 | ||
1833 | tree func = gimple_call_fndecl (stmt); | |
1834 | if (DECL_FUNCTION_CODE (func) == BUILT_IN_STPNCPY) | |
1835 | { | |
1836 | tree ret = gimple_call_lhs (stmt); | |
1837 | if (ret && operand_equal_p (ret, lhs, 0)) | |
1838 | return false; | |
1839 | } | |
1840 | ||
1841 | /* Determine the base address and offset of the reference, | |
1842 | ignoring the innermost array index. */ | |
1843 | if (TREE_CODE (ref) == ARRAY_REF) | |
1844 | ref = TREE_OPERAND (ref, 0); | |
1845 | ||
773078cb | 1846 | poly_int64 dstoff; |
0c45740b | 1847 | tree dstbase = get_addr_base_and_unit_offset (ref, &dstoff); |
1848 | ||
773078cb | 1849 | poly_int64 lhsoff; |
0c45740b | 1850 | tree lhsbase = get_addr_base_and_unit_offset (lhs, &lhsoff); |
1851 | if (lhsbase | |
7ecf8409 | 1852 | && dstbase |
773078cb | 1853 | && known_eq (dstoff, lhsoff) |
0c45740b | 1854 | && operand_equal_p (dstbase, lhsbase, 0)) |
d8aad786 | 1855 | return false; |
1856 | } | |
1857 | ||
1858 | int prec = TYPE_PRECISION (TREE_TYPE (cnt)); | |
1859 | wide_int lenrange[2]; | |
1860 | if (strinfo *sisrc = sidx > 0 ? get_strinfo (sidx) : NULL) | |
1861 | { | |
1862 | lenrange[0] = (sisrc->nonzero_chars | |
1863 | && TREE_CODE (sisrc->nonzero_chars) == INTEGER_CST | |
1864 | ? wi::to_wide (sisrc->nonzero_chars) | |
1865 | : wi::zero (prec)); | |
1866 | lenrange[1] = lenrange[0]; | |
1867 | } | |
1868 | else if (sidx < 0) | |
1869 | lenrange[0] = lenrange[1] = wi::shwi (~sidx, prec); | |
1870 | else | |
1871 | { | |
1872 | tree range[2]; | |
1873 | get_range_strlen (src, range); | |
2b796b45 | 1874 | if (range[0] != NULL_TREE |
1875 | && TREE_CODE (range[0]) == INTEGER_CST | |
1876 | && range[1] != NULL_TREE | |
1877 | && TREE_CODE (range[1]) == INTEGER_CST) | |
d8aad786 | 1878 | { |
1879 | lenrange[0] = wi::to_wide (range[0], prec); | |
1880 | lenrange[1] = wi::to_wide (range[1], prec); | |
1881 | } | |
1882 | else | |
1883 | { | |
1884 | lenrange[0] = wi::shwi (0, prec); | |
1885 | lenrange[1] = wi::shwi (-1, prec); | |
1886 | } | |
1887 | } | |
1888 | ||
1889 | location_t callloc = gimple_location (stmt); | |
1890 | tree func = gimple_call_fndecl (stmt); | |
1891 | ||
1892 | if (lenrange[0] != 0 || !wi::neg_p (lenrange[1])) | |
1893 | { | |
1894 | /* If the longest source string is shorter than the lower bound | |
1895 | of the specified count the copy is definitely nul-terminated. */ | |
1896 | if (wi::ltu_p (lenrange[1], cntrange[0])) | |
1897 | return false; | |
1898 | ||
1899 | if (wi::neg_p (lenrange[1])) | |
1900 | { | |
1901 | /* The length of one of the strings is unknown but at least | |
1902 | one has non-zero length and that length is stored in | |
1903 | LENRANGE[1]. Swap the bounds to force a "may be truncated" | |
1904 | warning below. */ | |
1905 | lenrange[1] = lenrange[0]; | |
1906 | lenrange[0] = wi::shwi (0, prec); | |
1907 | } | |
1908 | ||
bcb285a0 | 1909 | gcall *call = as_a <gcall *> (stmt); |
1910 | ||
1911 | if (lenrange[0] == cntrange[1] && cntrange[0] == cntrange[1]) | |
f4e3e4b1 | 1912 | return warning_n (callloc, OPT_Wstringop_truncation, |
1913 | cntrange[0].to_uhwi (), | |
1914 | "%G%qD output truncated before terminating " | |
1915 | "nul copying %E byte from a string of the " | |
1916 | "same length", | |
1917 | "%G%qD output truncated before terminating nul " | |
1918 | "copying %E bytes from a string of the same " | |
1919 | "length", | |
1920 | call, func, cnt); | |
bcb285a0 | 1921 | else if (wi::geu_p (lenrange[0], cntrange[1])) |
d8aad786 | 1922 | { |
1923 | /* The shortest string is longer than the upper bound of | |
1924 | the count so the truncation is certain. */ | |
1925 | if (cntrange[0] == cntrange[1]) | |
f4e3e4b1 | 1926 | return warning_n (callloc, OPT_Wstringop_truncation, |
1927 | cntrange[0].to_uhwi (), | |
1928 | "%G%qD output truncated copying %E byte " | |
1929 | "from a string of length %wu", | |
1930 | "%G%qD output truncated copying %E bytes " | |
1931 | "from a string of length %wu", | |
1932 | call, func, cnt, lenrange[0].to_uhwi ()); | |
d8aad786 | 1933 | |
1934 | return warning_at (callloc, OPT_Wstringop_truncation, | |
bcb285a0 | 1935 | "%G%qD output truncated copying between %wu " |
d8aad786 | 1936 | "and %wu bytes from a string of length %wu", |
bcb285a0 | 1937 | call, func, cntrange[0].to_uhwi (), |
d8aad786 | 1938 | cntrange[1].to_uhwi (), lenrange[0].to_uhwi ()); |
1939 | } | |
1940 | else if (wi::geu_p (lenrange[1], cntrange[1])) | |
1941 | { | |
1942 | /* The longest string is longer than the upper bound of | |
1943 | the count so the truncation is possible. */ | |
1944 | if (cntrange[0] == cntrange[1]) | |
f4e3e4b1 | 1945 | return warning_n (callloc, OPT_Wstringop_truncation, |
1946 | cntrange[0].to_uhwi (), | |
1947 | "%G%qD output may be truncated copying %E " | |
1948 | "byte from a string of length %wu", | |
1949 | "%G%qD output may be truncated copying %E " | |
1950 | "bytes from a string of length %wu", | |
1951 | call, func, cnt, lenrange[1].to_uhwi ()); | |
d8aad786 | 1952 | |
1953 | return warning_at (callloc, OPT_Wstringop_truncation, | |
bcb285a0 | 1954 | "%G%qD output may be truncated copying between %wu " |
d8aad786 | 1955 | "and %wu bytes from a string of length %wu", |
bcb285a0 | 1956 | call, func, cntrange[0].to_uhwi (), |
d8aad786 | 1957 | cntrange[1].to_uhwi (), lenrange[1].to_uhwi ()); |
1958 | } | |
1959 | ||
1960 | if (cntrange[0] != cntrange[1] | |
1961 | && wi::leu_p (cntrange[0], lenrange[0]) | |
1962 | && wi::leu_p (cntrange[1], lenrange[0] + 1)) | |
1963 | { | |
1964 | /* If the source (including the terminating nul) is longer than | |
1965 | the lower bound of the specified count but shorter than the | |
1966 | upper bound the copy may (but need not) be truncated. */ | |
1967 | return warning_at (callloc, OPT_Wstringop_truncation, | |
bcb285a0 | 1968 | "%G%qD output may be truncated copying between " |
1969 | "%wu and %wu bytes from a string of length %wu", | |
1970 | call, func, cntrange[0].to_uhwi (), | |
d8aad786 | 1971 | cntrange[1].to_uhwi (), lenrange[0].to_uhwi ()); |
1972 | } | |
1973 | } | |
1974 | ||
1975 | if (tree dstsize = compute_objsize (dst, 1)) | |
1976 | { | |
1977 | /* The source length is uknown. Try to determine the destination | |
1978 | size and see if it matches the specified bound. If not, bail. | |
1979 | Otherwise go on to see if it should be diagnosed for possible | |
1980 | truncation. */ | |
1981 | if (!dstsize) | |
1982 | return false; | |
1983 | ||
1984 | if (wi::to_wide (dstsize) != cntrange[1]) | |
1985 | return false; | |
1986 | ||
1987 | if (cntrange[0] == cntrange[1]) | |
1988 | return warning_at (callloc, OPT_Wstringop_truncation, | |
bcb285a0 | 1989 | "%G%qD specified bound %E equals destination size", |
1990 | as_a <gcall *> (stmt), func, cnt); | |
d8aad786 | 1991 | } |
1992 | ||
1993 | return false; | |
1994 | } | |
1995 | ||
e6a18b5a | 1996 | /* Check the arguments to the built-in forms of stpncpy and strncpy for |
1997 | out-of-bounds offsets or overlapping access, and to see if the size | |
1998 | is derived from calling strlen() on the source argument, and if so, | |
1999 | issue the appropriate warning. */ | |
d8aad786 | 2000 | |
2001 | static void | |
2002 | handle_builtin_stxncpy (built_in_function, gimple_stmt_iterator *gsi) | |
2003 | { | |
0c45740b | 2004 | if (!strlen_to_stridx) |
2005 | return; | |
2006 | ||
d8aad786 | 2007 | gimple *stmt = gsi_stmt (*gsi); |
2008 | ||
1e42d5c6 | 2009 | tree dst = gimple_call_arg (stmt, 0); |
2010 | tree src = gimple_call_arg (stmt, 1); | |
2011 | tree len = gimple_call_arg (stmt, 2); | |
e6a18b5a | 2012 | tree dstsize = NULL_TREE, srcsize = NULL_TREE; |
2013 | ||
2014 | int didx = get_stridx (dst); | |
2015 | if (strinfo *sidst = didx > 0 ? get_strinfo (didx) : NULL) | |
2016 | { | |
2017 | /* Compute the size of the destination string including the NUL. */ | |
2018 | if (sidst->nonzero_chars) | |
2019 | { | |
2020 | tree type = TREE_TYPE (sidst->nonzero_chars); | |
2021 | dstsize = fold_build2 (PLUS_EXPR, type, sidst->nonzero_chars, | |
2022 | build_int_cst (type, 1)); | |
2023 | } | |
2024 | dst = sidst->ptr; | |
2025 | } | |
2026 | ||
2027 | int sidx = get_stridx (src); | |
2028 | strinfo *sisrc = sidx > 0 ? get_strinfo (sidx) : NULL; | |
2029 | if (sisrc) | |
2030 | { | |
2031 | /* strncat() and strncpy() can modify the source string by writing | |
2032 | over the terminating nul so SISRC->DONT_INVALIDATE must be left | |
2033 | clear. */ | |
2034 | ||
2035 | /* Compute the size of the source string including the NUL. */ | |
2036 | if (sisrc->nonzero_chars) | |
2037 | { | |
2038 | tree type = TREE_TYPE (sisrc->nonzero_chars); | |
2039 | srcsize = fold_build2 (PLUS_EXPR, type, sisrc->nonzero_chars, | |
2040 | build_int_cst (type, 1)); | |
2041 | } | |
2042 | ||
2043 | src = sisrc->ptr; | |
2044 | } | |
2045 | else | |
2046 | srcsize = NULL_TREE; | |
2047 | ||
2048 | if (!check_bounds_or_overlap (as_a <gcall *>(stmt), dst, src, | |
2049 | dstsize, srcsize)) | |
2050 | { | |
2051 | gimple_set_no_warning (stmt, true); | |
2052 | return; | |
2053 | } | |
d8aad786 | 2054 | |
2055 | /* If the length argument was computed from strlen(S) for some string | |
2056 | S retrieve the strinfo index for the string (PSS->FIRST) alonng with | |
2057 | the location of the strlen() call (PSS->SECOND). */ | |
0c45740b | 2058 | stridx_strlenloc *pss = strlen_to_stridx->get (len); |
d8aad786 | 2059 | if (!pss || pss->first <= 0) |
2060 | { | |
2061 | if (maybe_diag_stxncpy_trunc (*gsi, src, len)) | |
2062 | gimple_set_no_warning (stmt, true); | |
2063 | ||
2064 | return; | |
2065 | } | |
2066 | ||
d8aad786 | 2067 | /* Retrieve the strinfo data for the string S that LEN was computed |
2068 | from as some function F of strlen (S) (i.e., LEN need not be equal | |
2069 | to strlen(S)). */ | |
2070 | strinfo *silen = get_strinfo (pss->first); | |
2071 | ||
2072 | location_t callloc = gimple_location (stmt); | |
2073 | ||
2074 | tree func = gimple_call_fndecl (stmt); | |
2075 | ||
2076 | bool warned = false; | |
2077 | ||
2078 | /* When -Wstringop-truncation is set, try to determine truncation | |
2079 | before diagnosing possible overflow. Truncation is implied by | |
2080 | the LEN argument being equal to strlen(SRC), regardless of | |
2081 | whether its value is known. Otherwise, issue the more generic | |
2082 | -Wstringop-overflow which triggers for LEN arguments that in | |
2083 | any meaningful way depend on strlen(SRC). */ | |
0c45740b | 2084 | if (sisrc == silen |
2085 | && is_strlen_related_p (src, len) | |
2086 | && warning_at (callloc, OPT_Wstringop_truncation, | |
bcb285a0 | 2087 | "%G%qD output truncated before terminating nul " |
0c45740b | 2088 | "copying as many bytes from a string as its length", |
bcb285a0 | 2089 | as_a <gcall *>(stmt), func)) |
0c45740b | 2090 | warned = true; |
d8aad786 | 2091 | else if (silen && is_strlen_related_p (src, silen->ptr)) |
2092 | warned = warning_at (callloc, OPT_Wstringop_overflow_, | |
bcb285a0 | 2093 | "%G%qD specified bound depends on the length " |
2094 | "of the source argument", | |
2095 | as_a <gcall *>(stmt), func); | |
d8aad786 | 2096 | if (warned) |
2097 | { | |
2098 | location_t strlenloc = pss->second; | |
2099 | if (strlenloc != UNKNOWN_LOCATION && strlenloc != callloc) | |
2100 | inform (strlenloc, "length computed here"); | |
2101 | } | |
2102 | } | |
2103 | ||
9efe50a4 | 2104 | /* Handle a memcpy-like ({mem{,p}cpy,__mem{,p}cpy_chk}) call. |
2105 | If strlen of the second argument is known and length of the third argument | |
2106 | is that plus one, strlen of the first argument is the same after this | |
2107 | call. */ | |
2108 | ||
2109 | static void | |
2110 | handle_builtin_memcpy (enum built_in_function bcode, gimple_stmt_iterator *gsi) | |
2111 | { | |
2112 | int idx, didx; | |
2113 | tree src, dst, len, lhs, oldlen, newlen; | |
42acab1c | 2114 | gimple *stmt = gsi_stmt (*gsi); |
04009ada | 2115 | strinfo *si, *dsi, *olddsi; |
9efe50a4 | 2116 | |
1e42d5c6 | 2117 | len = gimple_call_arg (stmt, 2); |
2118 | src = gimple_call_arg (stmt, 1); | |
9efe50a4 | 2119 | dst = gimple_call_arg (stmt, 0); |
2120 | idx = get_stridx (src); | |
2121 | if (idx == 0) | |
2122 | return; | |
2123 | ||
2124 | didx = get_stridx (dst); | |
2125 | olddsi = NULL; | |
2126 | if (didx > 0) | |
2127 | olddsi = get_strinfo (didx); | |
2128 | else if (didx < 0) | |
2129 | return; | |
2130 | ||
2131 | if (olddsi != NULL | |
cd4547bf | 2132 | && tree_fits_uhwi_p (len) |
9efe50a4 | 2133 | && !integer_zerop (len)) |
2134 | adjust_last_stmt (olddsi, stmt, false); | |
2135 | ||
f6ab81c1 | 2136 | bool full_string_p; |
9efe50a4 | 2137 | if (idx > 0) |
2138 | { | |
42acab1c | 2139 | gimple *def_stmt; |
9efe50a4 | 2140 | |
f6ab81c1 | 2141 | /* Handle memcpy (x, y, l) where l's relationship with strlen (y) |
2142 | is known. */ | |
9efe50a4 | 2143 | si = get_strinfo (idx); |
f6ab81c1 | 2144 | if (si == NULL || si->nonzero_chars == NULL_TREE) |
9efe50a4 | 2145 | return; |
f6ab81c1 | 2146 | if (TREE_CODE (len) == INTEGER_CST |
2147 | && TREE_CODE (si->nonzero_chars) == INTEGER_CST) | |
2148 | { | |
2149 | if (tree_int_cst_le (len, si->nonzero_chars)) | |
2150 | { | |
2151 | /* Copying LEN nonzero characters, where LEN is constant. */ | |
2152 | newlen = len; | |
2153 | full_string_p = false; | |
2154 | } | |
2155 | else | |
2156 | { | |
2157 | /* Copying the whole of the analyzed part of SI. */ | |
2158 | newlen = si->nonzero_chars; | |
2159 | full_string_p = si->full_string_p; | |
2160 | } | |
2161 | } | |
2162 | else | |
2163 | { | |
2164 | if (!si->full_string_p) | |
2165 | return; | |
2166 | if (TREE_CODE (len) != SSA_NAME) | |
2167 | return; | |
2168 | def_stmt = SSA_NAME_DEF_STMT (len); | |
2169 | if (!is_gimple_assign (def_stmt) | |
2170 | || gimple_assign_rhs_code (def_stmt) != PLUS_EXPR | |
2171 | || gimple_assign_rhs1 (def_stmt) != si->nonzero_chars | |
2172 | || !integer_onep (gimple_assign_rhs2 (def_stmt))) | |
2173 | return; | |
2174 | /* Copying variable-length string SI (and no more). */ | |
2175 | newlen = si->nonzero_chars; | |
2176 | full_string_p = true; | |
2177 | } | |
9efe50a4 | 2178 | } |
2179 | else | |
2180 | { | |
2181 | si = NULL; | |
2182 | /* Handle memcpy (x, "abcd", 5) or | |
2183 | memcpy (x, "abc\0uvw", 7). */ | |
f6ab81c1 | 2184 | if (!tree_fits_uhwi_p (len)) |
9efe50a4 | 2185 | return; |
f6ab81c1 | 2186 | |
2187 | unsigned HOST_WIDE_INT clen = tree_to_uhwi (len); | |
2188 | unsigned HOST_WIDE_INT nonzero_chars = ~idx; | |
2189 | newlen = build_int_cst (size_type_node, MIN (nonzero_chars, clen)); | |
2190 | full_string_p = clen > nonzero_chars; | |
9efe50a4 | 2191 | } |
2192 | ||
2193 | if (olddsi != NULL && TREE_CODE (len) == SSA_NAME) | |
2194 | adjust_last_stmt (olddsi, stmt, false); | |
2195 | ||
2196 | if (didx == 0) | |
2197 | { | |
2198 | didx = new_stridx (dst); | |
2199 | if (didx == 0) | |
2200 | return; | |
2201 | } | |
9efe50a4 | 2202 | oldlen = NULL_TREE; |
2203 | if (olddsi != NULL) | |
2204 | { | |
2205 | dsi = unshare_strinfo (olddsi); | |
f6ab81c1 | 2206 | oldlen = olddsi->nonzero_chars; |
2207 | dsi->nonzero_chars = newlen; | |
2208 | dsi->full_string_p = full_string_p; | |
9efe50a4 | 2209 | /* Break the chain, so adjust_related_strinfo on later pointers in |
2210 | the chain won't adjust this one anymore. */ | |
2211 | dsi->next = 0; | |
2212 | dsi->stmt = NULL; | |
2213 | dsi->endptr = NULL_TREE; | |
2214 | } | |
2215 | else | |
2216 | { | |
f6ab81c1 | 2217 | dsi = new_strinfo (dst, didx, newlen, full_string_p); |
9efe50a4 | 2218 | set_strinfo (didx, dsi); |
2219 | find_equal_ptrs (dst, didx); | |
2220 | } | |
2221 | dsi->writable = true; | |
2222 | dsi->dont_invalidate = true; | |
2223 | if (olddsi != NULL) | |
2224 | { | |
2225 | tree adj = NULL_TREE; | |
2226 | location_t loc = gimple_location (stmt); | |
2227 | if (oldlen == NULL_TREE) | |
2228 | ; | |
2229 | else if (integer_zerop (oldlen)) | |
f6ab81c1 | 2230 | adj = newlen; |
9efe50a4 | 2231 | else if (TREE_CODE (oldlen) == INTEGER_CST |
f6ab81c1 | 2232 | || TREE_CODE (newlen) == INTEGER_CST) |
2233 | adj = fold_build2_loc (loc, MINUS_EXPR, TREE_TYPE (newlen), newlen, | |
2234 | fold_convert_loc (loc, TREE_TYPE (newlen), | |
9efe50a4 | 2235 | oldlen)); |
2236 | if (adj != NULL_TREE) | |
2237 | adjust_related_strinfos (loc, dsi, adj); | |
2238 | else | |
2239 | dsi->prev = 0; | |
2240 | } | |
2241 | /* memcpy src may not overlap dst, so src doesn't need to be | |
2242 | invalidated either. */ | |
2243 | if (si != NULL) | |
2244 | si->dont_invalidate = true; | |
2245 | ||
f6ab81c1 | 2246 | if (full_string_p) |
9efe50a4 | 2247 | { |
f6ab81c1 | 2248 | lhs = gimple_call_lhs (stmt); |
2249 | switch (bcode) | |
2250 | { | |
2251 | case BUILT_IN_MEMCPY: | |
2252 | case BUILT_IN_MEMCPY_CHK: | |
f6ab81c1 | 2253 | /* Allow adjust_last_stmt to decrease this memcpy's size. */ |
2254 | laststmt.stmt = stmt; | |
2255 | laststmt.len = dsi->nonzero_chars; | |
2256 | laststmt.stridx = dsi->idx; | |
2257 | if (lhs) | |
2258 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] = didx; | |
2259 | break; | |
2260 | case BUILT_IN_MEMPCPY: | |
2261 | case BUILT_IN_MEMPCPY_CHK: | |
f6ab81c1 | 2262 | break; |
2263 | default: | |
2264 | gcc_unreachable (); | |
2265 | } | |
9efe50a4 | 2266 | } |
2267 | } | |
2268 | ||
2269 | /* Handle a strcat-like ({strcat,__strcat_chk}) call. | |
2270 | If strlen of the second argument is known, strlen of the first argument | |
2271 | is increased by the length of the second argument. Furthermore, attempt | |
2272 | to convert it to memcpy/strcpy if the length of the first argument | |
2273 | is known. */ | |
2274 | ||
2275 | static void | |
2276 | handle_builtin_strcat (enum built_in_function bcode, gimple_stmt_iterator *gsi) | |
2277 | { | |
2278 | int idx, didx; | |
e6a18b5a | 2279 | tree srclen, args, type, fn, objsz, endptr; |
9efe50a4 | 2280 | bool success; |
42acab1c | 2281 | gimple *stmt = gsi_stmt (*gsi); |
04009ada | 2282 | strinfo *si, *dsi; |
e6a18b5a | 2283 | location_t loc = gimple_location (stmt); |
9efe50a4 | 2284 | |
1e42d5c6 | 2285 | tree src = gimple_call_arg (stmt, 1); |
e6a18b5a | 2286 | tree dst = gimple_call_arg (stmt, 0); |
2287 | ||
2288 | /* Bail if the source is the same as destination. It will be diagnosed | |
2289 | elsewhere. */ | |
2290 | if (operand_equal_p (src, dst, 0)) | |
2291 | return; | |
2292 | ||
2293 | tree lhs = gimple_call_lhs (stmt); | |
9efe50a4 | 2294 | |
2295 | didx = get_stridx (dst); | |
2296 | if (didx < 0) | |
2297 | return; | |
2298 | ||
2299 | dsi = NULL; | |
2300 | if (didx > 0) | |
2301 | dsi = get_strinfo (didx); | |
e6a18b5a | 2302 | |
2303 | srclen = NULL_TREE; | |
2304 | si = NULL; | |
2305 | idx = get_stridx (src); | |
2306 | if (idx < 0) | |
2307 | srclen = build_int_cst (size_type_node, ~idx); | |
2308 | else if (idx > 0) | |
2309 | { | |
2310 | si = get_strinfo (idx); | |
2311 | if (si != NULL) | |
2312 | srclen = get_string_length (si); | |
2313 | } | |
2314 | ||
2315 | /* Set the no-warning bit on the transformed statement? */ | |
2316 | bool set_no_warning = false; | |
2317 | ||
9efe50a4 | 2318 | if (dsi == NULL || get_string_length (dsi) == NULL_TREE) |
2319 | { | |
e6a18b5a | 2320 | { |
2321 | /* The concatenation always involves copying at least one byte | |
2322 | (the terminating nul), even if the source string is empty. | |
2323 | If the source is unknown assume it's one character long and | |
2324 | used that as both sizes. */ | |
2325 | tree slen = srclen; | |
2326 | if (slen) | |
2327 | { | |
2328 | tree type = TREE_TYPE (slen); | |
2329 | slen = fold_build2 (PLUS_EXPR, type, slen, build_int_cst (type, 1)); | |
2330 | } | |
2331 | ||
2332 | tree sptr = si && si->ptr ? si->ptr : src; | |
2333 | ||
2334 | if (!check_bounds_or_overlap (as_a <gcall *>(stmt), dst, sptr, | |
2335 | NULL_TREE, slen)) | |
2336 | { | |
2337 | gimple_set_no_warning (stmt, true); | |
2338 | set_no_warning = true; | |
2339 | } | |
2340 | } | |
2341 | ||
9efe50a4 | 2342 | /* strcat (p, q) can be transformed into |
e6a18b5a | 2343 | tmp = p + strlen (p); endptr = stpcpy (tmp, q); |
9efe50a4 | 2344 | with length endptr - p if we need to compute the length |
2345 | later on. Don't do this transformation if we don't need | |
2346 | it. */ | |
b9a16870 | 2347 | if (builtin_decl_implicit_p (BUILT_IN_STPCPY) && lhs == NULL_TREE) |
9efe50a4 | 2348 | { |
2349 | if (didx == 0) | |
2350 | { | |
2351 | didx = new_stridx (dst); | |
2352 | if (didx == 0) | |
2353 | return; | |
2354 | } | |
2355 | if (dsi == NULL) | |
2356 | { | |
f6ab81c1 | 2357 | dsi = new_strinfo (dst, didx, NULL_TREE, false); |
9efe50a4 | 2358 | set_strinfo (didx, dsi); |
2359 | find_equal_ptrs (dst, didx); | |
2360 | } | |
2361 | else | |
2362 | { | |
2363 | dsi = unshare_strinfo (dsi); | |
f6ab81c1 | 2364 | dsi->nonzero_chars = NULL_TREE; |
2365 | dsi->full_string_p = false; | |
9efe50a4 | 2366 | dsi->next = 0; |
2367 | dsi->endptr = NULL_TREE; | |
2368 | } | |
2369 | dsi->writable = true; | |
2370 | dsi->stmt = stmt; | |
2371 | dsi->dont_invalidate = true; | |
2372 | } | |
2373 | return; | |
2374 | } | |
2375 | ||
e6a18b5a | 2376 | tree dstlen = dsi->nonzero_chars; |
9efe50a4 | 2377 | endptr = dsi->endptr; |
2378 | ||
2379 | dsi = unshare_strinfo (dsi); | |
2380 | dsi->endptr = NULL_TREE; | |
2381 | dsi->stmt = NULL; | |
2382 | dsi->writable = true; | |
2383 | ||
2384 | if (srclen != NULL_TREE) | |
2385 | { | |
f6ab81c1 | 2386 | dsi->nonzero_chars = fold_build2_loc (loc, PLUS_EXPR, |
2387 | TREE_TYPE (dsi->nonzero_chars), | |
2388 | dsi->nonzero_chars, srclen); | |
2389 | gcc_assert (dsi->full_string_p); | |
9efe50a4 | 2390 | adjust_related_strinfos (loc, dsi, srclen); |
2391 | dsi->dont_invalidate = true; | |
2392 | } | |
2393 | else | |
2394 | { | |
f6ab81c1 | 2395 | dsi->nonzero_chars = NULL; |
2396 | dsi->full_string_p = false; | |
b9a16870 | 2397 | if (lhs == NULL_TREE && builtin_decl_implicit_p (BUILT_IN_STPCPY)) |
9efe50a4 | 2398 | dsi->dont_invalidate = true; |
2399 | } | |
2400 | ||
2401 | if (si != NULL) | |
2402 | /* strcat src may not overlap dst, so src doesn't need to be | |
2403 | invalidated either. */ | |
2404 | si->dont_invalidate = true; | |
2405 | ||
2406 | /* For now. Could remove the lhs from the call and add | |
2407 | lhs = dst; afterwards. */ | |
2408 | if (lhs) | |
2409 | return; | |
2410 | ||
2411 | fn = NULL_TREE; | |
2412 | objsz = NULL_TREE; | |
2413 | switch (bcode) | |
2414 | { | |
2415 | case BUILT_IN_STRCAT: | |
2416 | if (srclen != NULL_TREE) | |
b9a16870 | 2417 | fn = builtin_decl_implicit (BUILT_IN_MEMCPY); |
9efe50a4 | 2418 | else |
b9a16870 | 2419 | fn = builtin_decl_implicit (BUILT_IN_STRCPY); |
9efe50a4 | 2420 | break; |
2421 | case BUILT_IN_STRCAT_CHK: | |
2422 | if (srclen != NULL_TREE) | |
b9a16870 | 2423 | fn = builtin_decl_explicit (BUILT_IN_MEMCPY_CHK); |
9efe50a4 | 2424 | else |
b9a16870 | 2425 | fn = builtin_decl_explicit (BUILT_IN_STRCPY_CHK); |
1e42d5c6 | 2426 | objsz = gimple_call_arg (stmt, 2); |
9efe50a4 | 2427 | break; |
2428 | default: | |
2429 | gcc_unreachable (); | |
2430 | } | |
2431 | ||
2432 | if (fn == NULL_TREE) | |
2433 | return; | |
2434 | ||
e6a18b5a | 2435 | if (dsi && dstlen) |
2436 | { | |
2437 | tree type = TREE_TYPE (dstlen); | |
2438 | ||
2439 | /* Compute the size of the source sequence, including the nul. */ | |
2440 | tree srcsize = srclen ? srclen : size_zero_node; | |
2441 | srcsize = fold_build2 (PLUS_EXPR, type, srcsize, build_int_cst (type, 1)); | |
2442 | ||
2443 | tree sptr = si && si->ptr ? si->ptr : src; | |
2444 | ||
2445 | if (!check_bounds_or_overlap (as_a <gcall *>(stmt), dst, sptr, | |
2446 | dstlen, srcsize)) | |
2447 | { | |
2448 | gimple_set_no_warning (stmt, true); | |
2449 | set_no_warning = true; | |
2450 | } | |
2451 | } | |
2452 | ||
2453 | tree len = NULL_TREE; | |
9efe50a4 | 2454 | if (srclen != NULL_TREE) |
2455 | { | |
2456 | args = TYPE_ARG_TYPES (TREE_TYPE (fn)); | |
2457 | type = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (args))); | |
2458 | ||
2459 | len = fold_convert_loc (loc, type, unshare_expr (srclen)); | |
2460 | len = fold_build2_loc (loc, PLUS_EXPR, type, len, | |
2461 | build_int_cst (type, 1)); | |
2462 | len = force_gimple_operand_gsi (gsi, len, true, NULL_TREE, true, | |
2463 | GSI_SAME_STMT); | |
2464 | } | |
2465 | if (endptr) | |
2466 | dst = fold_convert_loc (loc, TREE_TYPE (dst), unshare_expr (endptr)); | |
2467 | else | |
2468 | dst = fold_build2_loc (loc, POINTER_PLUS_EXPR, | |
2469 | TREE_TYPE (dst), unshare_expr (dst), | |
2470 | fold_convert_loc (loc, sizetype, | |
2471 | unshare_expr (dstlen))); | |
2472 | dst = force_gimple_operand_gsi (gsi, dst, true, NULL_TREE, true, | |
2473 | GSI_SAME_STMT); | |
2474 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
2475 | { | |
2476 | fprintf (dump_file, "Optimizing: "); | |
2477 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
2478 | } | |
1e42d5c6 | 2479 | if (srclen != NULL_TREE) |
2480 | success = update_gimple_call (gsi, fn, 3 + (objsz != NULL_TREE), | |
2481 | dst, src, len, objsz); | |
9efe50a4 | 2482 | else |
1e42d5c6 | 2483 | success = update_gimple_call (gsi, fn, 2 + (objsz != NULL_TREE), |
2484 | dst, src, objsz); | |
9efe50a4 | 2485 | if (success) |
2486 | { | |
2487 | stmt = gsi_stmt (*gsi); | |
2488 | update_stmt (stmt); | |
2489 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
2490 | { | |
2491 | fprintf (dump_file, "into: "); | |
2492 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
2493 | } | |
2494 | /* If srclen == NULL, note that current string length can be | |
2495 | computed by transforming this strcpy into stpcpy. */ | |
2496 | if (srclen == NULL_TREE && dsi->dont_invalidate) | |
2497 | dsi->stmt = stmt; | |
2498 | adjust_last_stmt (dsi, stmt, true); | |
2499 | if (srclen != NULL_TREE) | |
2500 | { | |
2501 | laststmt.stmt = stmt; | |
2502 | laststmt.len = srclen; | |
2503 | laststmt.stridx = dsi->idx; | |
2504 | } | |
2505 | } | |
2506 | else if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
2507 | fprintf (dump_file, "not possible.\n"); | |
e6a18b5a | 2508 | |
2509 | if (set_no_warning) | |
2510 | gimple_set_no_warning (stmt, true); | |
9efe50a4 | 2511 | } |
2512 | ||
9f15ed6e | 2513 | /* Handle a call to malloc or calloc. */ |
2514 | ||
2515 | static void | |
2516 | handle_builtin_malloc (enum built_in_function bcode, gimple_stmt_iterator *gsi) | |
2517 | { | |
42acab1c | 2518 | gimple *stmt = gsi_stmt (*gsi); |
9f15ed6e | 2519 | tree lhs = gimple_call_lhs (stmt); |
566ab12f | 2520 | if (lhs == NULL_TREE) |
2521 | return; | |
2522 | ||
9f15ed6e | 2523 | gcc_assert (get_stridx (lhs) == 0); |
2524 | int idx = new_stridx (lhs); | |
2525 | tree length = NULL_TREE; | |
2526 | if (bcode == BUILT_IN_CALLOC) | |
2527 | length = build_int_cst (size_type_node, 0); | |
f6ab81c1 | 2528 | strinfo *si = new_strinfo (lhs, idx, length, length != NULL_TREE); |
9f15ed6e | 2529 | if (bcode == BUILT_IN_CALLOC) |
2530 | si->endptr = lhs; | |
2531 | set_strinfo (idx, si); | |
2532 | si->writable = true; | |
2533 | si->stmt = stmt; | |
2534 | si->dont_invalidate = true; | |
2535 | } | |
2536 | ||
2537 | /* Handle a call to memset. | |
2538 | After a call to calloc, memset(,0,) is unnecessary. | |
72dbc21d | 2539 | memset(malloc(n),0,n) is calloc(n,1). |
2540 | return true when the call is transfomred, false otherwise. */ | |
9f15ed6e | 2541 | |
2542 | static bool | |
2543 | handle_builtin_memset (gimple_stmt_iterator *gsi) | |
2544 | { | |
42acab1c | 2545 | gimple *stmt2 = gsi_stmt (*gsi); |
9f15ed6e | 2546 | if (!integer_zerop (gimple_call_arg (stmt2, 1))) |
72dbc21d | 2547 | return false; |
9f15ed6e | 2548 | tree ptr = gimple_call_arg (stmt2, 0); |
2549 | int idx1 = get_stridx (ptr); | |
2550 | if (idx1 <= 0) | |
72dbc21d | 2551 | return false; |
04009ada | 2552 | strinfo *si1 = get_strinfo (idx1); |
9f15ed6e | 2553 | if (!si1) |
72dbc21d | 2554 | return false; |
42acab1c | 2555 | gimple *stmt1 = si1->stmt; |
9f15ed6e | 2556 | if (!stmt1 || !is_gimple_call (stmt1)) |
72dbc21d | 2557 | return false; |
9f15ed6e | 2558 | tree callee1 = gimple_call_fndecl (stmt1); |
ec15ec36 | 2559 | if (!valid_builtin_call (stmt1)) |
72dbc21d | 2560 | return false; |
9f15ed6e | 2561 | enum built_in_function code1 = DECL_FUNCTION_CODE (callee1); |
2562 | tree size = gimple_call_arg (stmt2, 2); | |
2563 | if (code1 == BUILT_IN_CALLOC) | |
2564 | /* Not touching stmt1 */ ; | |
2565 | else if (code1 == BUILT_IN_MALLOC | |
2566 | && operand_equal_p (gimple_call_arg (stmt1, 0), size, 0)) | |
2567 | { | |
2568 | gimple_stmt_iterator gsi1 = gsi_for_stmt (stmt1); | |
2569 | update_gimple_call (&gsi1, builtin_decl_implicit (BUILT_IN_CALLOC), 2, | |
2570 | size, build_one_cst (size_type_node)); | |
f6ab81c1 | 2571 | si1->nonzero_chars = build_int_cst (size_type_node, 0); |
2572 | si1->full_string_p = true; | |
9e2c064e | 2573 | si1->stmt = gsi_stmt (gsi1); |
9f15ed6e | 2574 | } |
2575 | else | |
72dbc21d | 2576 | return false; |
9f15ed6e | 2577 | tree lhs = gimple_call_lhs (stmt2); |
2578 | unlink_stmt_vdef (stmt2); | |
2579 | if (lhs) | |
2580 | { | |
42acab1c | 2581 | gimple *assign = gimple_build_assign (lhs, ptr); |
9f15ed6e | 2582 | gsi_replace (gsi, assign, false); |
2583 | } | |
2584 | else | |
2585 | { | |
2586 | gsi_remove (gsi, true); | |
2587 | release_defs (stmt2); | |
2588 | } | |
2589 | ||
72dbc21d | 2590 | return true; |
9f15ed6e | 2591 | } |
2592 | ||
3e346f54 | 2593 | /* Handle a call to memcmp. We try to handle small comparisons by |
2594 | converting them to load and compare, and replacing the call to memcmp | |
72dbc21d | 2595 | with a __builtin_memcmp_eq call where possible. |
2596 | return true when call is transformed, return false otherwise. */ | |
3e346f54 | 2597 | |
2598 | static bool | |
2599 | handle_builtin_memcmp (gimple_stmt_iterator *gsi) | |
2600 | { | |
2601 | gcall *stmt2 = as_a <gcall *> (gsi_stmt (*gsi)); | |
2602 | tree res = gimple_call_lhs (stmt2); | |
2603 | tree arg1 = gimple_call_arg (stmt2, 0); | |
2604 | tree arg2 = gimple_call_arg (stmt2, 1); | |
2605 | tree len = gimple_call_arg (stmt2, 2); | |
2606 | unsigned HOST_WIDE_INT leni; | |
2607 | use_operand_p use_p; | |
2608 | imm_use_iterator iter; | |
2609 | ||
2610 | if (!res) | |
72dbc21d | 2611 | return false; |
3e346f54 | 2612 | |
2613 | FOR_EACH_IMM_USE_FAST (use_p, iter, res) | |
2614 | { | |
2615 | gimple *ustmt = USE_STMT (use_p); | |
2616 | ||
9d700ce4 | 2617 | if (is_gimple_debug (ustmt)) |
2618 | continue; | |
3e346f54 | 2619 | if (gimple_code (ustmt) == GIMPLE_ASSIGN) |
2620 | { | |
2621 | gassign *asgn = as_a <gassign *> (ustmt); | |
2622 | tree_code code = gimple_assign_rhs_code (asgn); | |
2623 | if ((code != EQ_EXPR && code != NE_EXPR) | |
2624 | || !integer_zerop (gimple_assign_rhs2 (asgn))) | |
72dbc21d | 2625 | return false; |
3e346f54 | 2626 | } |
2627 | else if (gimple_code (ustmt) == GIMPLE_COND) | |
2628 | { | |
2629 | tree_code code = gimple_cond_code (ustmt); | |
2630 | if ((code != EQ_EXPR && code != NE_EXPR) | |
2631 | || !integer_zerop (gimple_cond_rhs (ustmt))) | |
72dbc21d | 2632 | return false; |
3e346f54 | 2633 | } |
2634 | else | |
72dbc21d | 2635 | return false; |
3e346f54 | 2636 | } |
2637 | ||
2638 | if (tree_fits_uhwi_p (len) | |
2639 | && (leni = tree_to_uhwi (len)) <= GET_MODE_SIZE (word_mode) | |
ac29ece2 | 2640 | && pow2p_hwi (leni)) |
3e346f54 | 2641 | { |
2642 | leni *= CHAR_TYPE_SIZE; | |
2643 | unsigned align1 = get_pointer_alignment (arg1); | |
2644 | unsigned align2 = get_pointer_alignment (arg2); | |
2645 | unsigned align = MIN (align1, align2); | |
44504d18 | 2646 | scalar_int_mode mode; |
2647 | if (int_mode_for_size (leni, 1).exists (&mode) | |
dfdced85 | 2648 | && (align >= leni || !targetm.slow_unaligned_access (mode, align))) |
3e346f54 | 2649 | { |
2650 | location_t loc = gimple_location (stmt2); | |
2651 | tree type, off; | |
2652 | type = build_nonstandard_integer_type (leni, 1); | |
eafbcd13 | 2653 | gcc_assert (known_eq (GET_MODE_BITSIZE (TYPE_MODE (type)), leni)); |
3e346f54 | 2654 | tree ptrtype = build_pointer_type_for_mode (char_type_node, |
2655 | ptr_mode, true); | |
2656 | off = build_int_cst (ptrtype, 0); | |
2657 | arg1 = build2_loc (loc, MEM_REF, type, arg1, off); | |
2658 | arg2 = build2_loc (loc, MEM_REF, type, arg2, off); | |
2659 | tree tem1 = fold_const_aggregate_ref (arg1); | |
2660 | if (tem1) | |
2661 | arg1 = tem1; | |
2662 | tree tem2 = fold_const_aggregate_ref (arg2); | |
2663 | if (tem2) | |
2664 | arg2 = tem2; | |
2665 | res = fold_convert_loc (loc, TREE_TYPE (res), | |
2666 | fold_build2_loc (loc, NE_EXPR, | |
2667 | boolean_type_node, | |
2668 | arg1, arg2)); | |
2669 | gimplify_and_update_call_from_tree (gsi, res); | |
72dbc21d | 2670 | return true; |
3e346f54 | 2671 | } |
2672 | } | |
2673 | ||
2674 | gimple_call_set_fndecl (stmt2, builtin_decl_explicit (BUILT_IN_MEMCMP_EQ)); | |
72dbc21d | 2675 | return true; |
2676 | } | |
2677 | ||
2678 | /* Given an index to the strinfo vector, compute the string length for the | |
2679 | corresponding string. Return -1 when unknown. */ | |
2680 | ||
2681 | static HOST_WIDE_INT | |
2682 | compute_string_length (int idx) | |
2683 | { | |
2684 | HOST_WIDE_INT string_leni = -1; | |
2685 | gcc_assert (idx != 0); | |
2686 | ||
2687 | if (idx < 0) | |
2688 | return ~idx; | |
2689 | ||
2690 | strinfo *si = get_strinfo (idx); | |
2691 | if (si) | |
2692 | { | |
2693 | tree const_string_len = get_string_length (si); | |
2694 | if (const_string_len && tree_fits_shwi_p (const_string_len)) | |
2695 | string_leni = tree_to_shwi (const_string_len); | |
2696 | } | |
2697 | ||
2698 | if (string_leni < 0) | |
2699 | return -1; | |
2700 | ||
2701 | return string_leni; | |
2702 | } | |
2703 | ||
2704 | /* Determine the minimum size of the object referenced by DEST expression which | |
2705 | must have a pointer type. | |
2706 | Return the minimum size of the object if successful or NULL when the size | |
2707 | cannot be determined. */ | |
2708 | static tree | |
2709 | determine_min_objsize (tree dest) | |
2710 | { | |
2711 | unsigned HOST_WIDE_INT size = 0; | |
2712 | ||
2713 | if (compute_builtin_object_size (dest, 2, &size)) | |
2714 | return build_int_cst (sizetype, size); | |
2715 | ||
2716 | /* Try to determine the size of the object through the RHS of the | |
2717 | assign statement. */ | |
2718 | if (TREE_CODE (dest) == SSA_NAME) | |
2719 | { | |
2720 | gimple *stmt = SSA_NAME_DEF_STMT (dest); | |
2721 | if (!is_gimple_assign (stmt)) | |
2722 | return NULL_TREE; | |
2723 | ||
2724 | if (!gimple_assign_single_p (stmt) | |
2725 | && !gimple_assign_unary_nop_p (stmt)) | |
2726 | return NULL_TREE; | |
2727 | ||
2728 | dest = gimple_assign_rhs1 (stmt); | |
2729 | return determine_min_objsize (dest); | |
2730 | } | |
2731 | ||
2732 | /* Try to determine the size of the object from its type. */ | |
2733 | if (TREE_CODE (dest) != ADDR_EXPR) | |
2734 | return NULL_TREE; | |
2735 | ||
2736 | tree type = TREE_TYPE (dest); | |
2737 | if (TREE_CODE (type) == POINTER_TYPE) | |
2738 | type = TREE_TYPE (type); | |
2739 | ||
2740 | type = TYPE_MAIN_VARIANT (type); | |
2741 | ||
2742 | /* We cannot determine the size of the array if it's a flexible array, | |
2743 | which is declared at the end of a structure. */ | |
2744 | if (TREE_CODE (type) == ARRAY_TYPE | |
2745 | && !array_at_struct_end_p (dest)) | |
2746 | { | |
2747 | tree size_t = TYPE_SIZE_UNIT (type); | |
2748 | if (size_t && TREE_CODE (size_t) == INTEGER_CST | |
2749 | && !integer_zerop (size_t)) | |
2750 | return size_t; | |
2751 | } | |
2752 | ||
2753 | return NULL_TREE; | |
2754 | } | |
2755 | ||
2756 | /* Handle a call to strcmp or strncmp. When the result is ONLY used to do | |
2757 | equality test against zero: | |
2758 | ||
2759 | A. When the lengths of both arguments are constant and it's a strcmp: | |
2760 | * if the lengths are NOT equal, we can safely fold the call | |
2761 | to a non-zero value. | |
2762 | * otherwise, do nothing now. | |
2763 | ||
2764 | B. When the length of one argument is constant, try to replace the call with | |
2765 | a __builtin_str(n)cmp_eq call where possible, i.e: | |
2766 | ||
2767 | strncmp (s, STR, C) (!)= 0 in which, s is a pointer to a string, STR is a | |
2768 | string with constant length , C is a constant. | |
2769 | if (C <= strlen(STR) && sizeof_array(s) > C) | |
2770 | { | |
2771 | replace this call with | |
2772 | strncmp_eq (s, STR, C) (!)= 0 | |
2773 | } | |
2774 | if (C > strlen(STR) | |
2775 | { | |
2776 | it can be safely treated as a call to strcmp (s, STR) (!)= 0 | |
2777 | can handled by the following strcmp. | |
2778 | } | |
2779 | ||
2780 | strcmp (s, STR) (!)= 0 in which, s is a pointer to a string, STR is a | |
2781 | string with constant length. | |
2782 | if (sizeof_array(s) > strlen(STR)) | |
2783 | { | |
2784 | replace this call with | |
2785 | strcmp_eq (s, STR, strlen(STR)+1) (!)= 0 | |
2786 | } | |
2787 | ||
2788 | Return true when the call is transformed, return false otherwise. | |
2789 | */ | |
2790 | ||
2791 | static bool | |
2792 | handle_builtin_string_cmp (gimple_stmt_iterator *gsi) | |
2793 | { | |
2794 | gcall *stmt = as_a <gcall *> (gsi_stmt (*gsi)); | |
2795 | tree res = gimple_call_lhs (stmt); | |
2796 | use_operand_p use_p; | |
2797 | imm_use_iterator iter; | |
2798 | tree arg1 = gimple_call_arg (stmt, 0); | |
2799 | tree arg2 = gimple_call_arg (stmt, 1); | |
2800 | int idx1 = get_stridx (arg1); | |
2801 | int idx2 = get_stridx (arg2); | |
2802 | HOST_WIDE_INT length = -1; | |
2803 | bool is_ncmp = false; | |
2804 | ||
2805 | if (!res) | |
2806 | return false; | |
2807 | ||
2808 | /* When both arguments are unknown, do nothing. */ | |
2809 | if (idx1 == 0 && idx2 == 0) | |
2810 | return false; | |
2811 | ||
2812 | /* Handle strncmp function. */ | |
2813 | if (gimple_call_num_args (stmt) == 3) | |
2814 | { | |
2815 | tree len = gimple_call_arg (stmt, 2); | |
2816 | if (tree_fits_shwi_p (len)) | |
2817 | length = tree_to_shwi (len); | |
2818 | ||
2819 | is_ncmp = true; | |
2820 | } | |
2821 | ||
2822 | /* For strncmp, if the length argument is NOT known, do nothing. */ | |
2823 | if (is_ncmp && length < 0) | |
2824 | return false; | |
2825 | ||
2826 | /* When the result is ONLY used to do equality test against zero. */ | |
2827 | FOR_EACH_IMM_USE_FAST (use_p, iter, res) | |
2828 | { | |
2829 | gimple *use_stmt = USE_STMT (use_p); | |
2830 | ||
2831 | if (is_gimple_debug (use_stmt)) | |
2832 | continue; | |
2833 | if (gimple_code (use_stmt) == GIMPLE_ASSIGN) | |
2834 | { | |
2835 | tree_code code = gimple_assign_rhs_code (use_stmt); | |
2836 | if (code == COND_EXPR) | |
2837 | { | |
2838 | tree cond_expr = gimple_assign_rhs1 (use_stmt); | |
2839 | if ((TREE_CODE (cond_expr) != EQ_EXPR | |
2840 | && (TREE_CODE (cond_expr) != NE_EXPR)) | |
2841 | || !integer_zerop (TREE_OPERAND (cond_expr, 1))) | |
2842 | return false; | |
2843 | } | |
2844 | else if (code == EQ_EXPR || code == NE_EXPR) | |
2845 | { | |
2846 | if (!integer_zerop (gimple_assign_rhs2 (use_stmt))) | |
2847 | return false; | |
2848 | } | |
2849 | else | |
2850 | return false; | |
2851 | } | |
2852 | else if (gimple_code (use_stmt) == GIMPLE_COND) | |
2853 | { | |
2854 | tree_code code = gimple_cond_code (use_stmt); | |
2855 | if ((code != EQ_EXPR && code != NE_EXPR) | |
2856 | || !integer_zerop (gimple_cond_rhs (use_stmt))) | |
2857 | return false; | |
2858 | } | |
2859 | else | |
2860 | return false; | |
2861 | } | |
2862 | ||
2863 | /* When the lengths of both arguments are known, and they are unequal, we can | |
2864 | safely fold the call to a non-zero value for strcmp; | |
2865 | othewise, do nothing now. */ | |
2866 | if (idx1 != 0 && idx2 != 0) | |
2867 | { | |
2868 | HOST_WIDE_INT const_string_leni1 = compute_string_length (idx1); | |
2869 | HOST_WIDE_INT const_string_leni2 = compute_string_length (idx2); | |
2870 | ||
2871 | if (!is_ncmp | |
2872 | && const_string_leni1 != -1 | |
2873 | && const_string_leni2 != -1 | |
2874 | && const_string_leni1 != const_string_leni2) | |
2875 | { | |
2876 | replace_call_with_value (gsi, integer_one_node); | |
2877 | return true; | |
2878 | } | |
2879 | return false; | |
2880 | } | |
2881 | ||
2882 | /* When the length of one argument is constant. */ | |
2883 | tree var_string = NULL_TREE; | |
2884 | HOST_WIDE_INT const_string_leni = -1; | |
2885 | ||
2886 | if (idx1) | |
2887 | { | |
2888 | const_string_leni = compute_string_length (idx1); | |
2889 | var_string = arg2; | |
2890 | } | |
2891 | else | |
2892 | { | |
2893 | gcc_checking_assert (idx2); | |
2894 | const_string_leni = compute_string_length (idx2); | |
2895 | var_string = arg1; | |
2896 | } | |
2897 | ||
2898 | if (const_string_leni < 0) | |
2899 | return false; | |
2900 | ||
2901 | unsigned HOST_WIDE_INT var_sizei = 0; | |
2902 | /* try to determine the minimum size of the object pointed by var_string. */ | |
2903 | tree size = determine_min_objsize (var_string); | |
2904 | ||
2905 | if (!size) | |
2906 | return false; | |
2907 | ||
2908 | if (tree_fits_uhwi_p (size)) | |
2909 | var_sizei = tree_to_uhwi (size); | |
2910 | ||
2911 | if (var_sizei == 0) | |
2912 | return false; | |
2913 | ||
2914 | /* For strncmp, if length > const_string_leni , this call can be safely | |
2915 | transformed to a strcmp. */ | |
2916 | if (is_ncmp && length > const_string_leni) | |
2917 | is_ncmp = false; | |
2918 | ||
2919 | unsigned HOST_WIDE_INT final_length | |
2920 | = is_ncmp ? length : const_string_leni + 1; | |
2921 | ||
2922 | /* Replace strcmp or strncmp with the corresponding str(n)cmp_eq. */ | |
2923 | if (var_sizei > final_length) | |
2924 | { | |
2925 | tree fn | |
2926 | = (is_ncmp | |
2927 | ? builtin_decl_implicit (BUILT_IN_STRNCMP_EQ) | |
2928 | : builtin_decl_implicit (BUILT_IN_STRCMP_EQ)); | |
2929 | if (!fn) | |
2930 | return false; | |
2931 | tree const_string_len = build_int_cst (size_type_node, final_length); | |
2932 | update_gimple_call (gsi, fn, 3, arg1, arg2, const_string_len); | |
2933 | } | |
2934 | else | |
2935 | return false; | |
2936 | ||
2937 | return true; | |
3e346f54 | 2938 | } |
2939 | ||
9efe50a4 | 2940 | /* Handle a POINTER_PLUS_EXPR statement. |
2941 | For p = "abcd" + 2; compute associated length, or if | |
2942 | p = q + off is pointing to a '\0' character of a string, call | |
2943 | zero_length_string on it. */ | |
2944 | ||
2945 | static void | |
2946 | handle_pointer_plus (gimple_stmt_iterator *gsi) | |
2947 | { | |
42acab1c | 2948 | gimple *stmt = gsi_stmt (*gsi); |
9efe50a4 | 2949 | tree lhs = gimple_assign_lhs (stmt), off; |
2950 | int idx = get_stridx (gimple_assign_rhs1 (stmt)); | |
04009ada | 2951 | strinfo *si, *zsi; |
9efe50a4 | 2952 | |
2953 | if (idx == 0) | |
2954 | return; | |
2955 | ||
2956 | if (idx < 0) | |
2957 | { | |
2958 | tree off = gimple_assign_rhs2 (stmt); | |
cd4547bf | 2959 | if (tree_fits_uhwi_p (off) |
aa59f000 | 2960 | && tree_to_uhwi (off) <= (unsigned HOST_WIDE_INT) ~idx) |
f1f41a6c | 2961 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] |
6a0712d4 | 2962 | = ~(~idx - (int) tree_to_uhwi (off)); |
9efe50a4 | 2963 | return; |
2964 | } | |
2965 | ||
2966 | si = get_strinfo (idx); | |
f6ab81c1 | 2967 | if (si == NULL || si->nonzero_chars == NULL_TREE) |
9efe50a4 | 2968 | return; |
2969 | ||
2970 | off = gimple_assign_rhs2 (stmt); | |
2971 | zsi = NULL; | |
f6ab81c1 | 2972 | if (si->full_string_p && operand_equal_p (si->nonzero_chars, off, 0)) |
9efe50a4 | 2973 | zsi = zero_length_string (lhs, si); |
2974 | else if (TREE_CODE (off) == SSA_NAME) | |
2975 | { | |
42acab1c | 2976 | gimple *def_stmt = SSA_NAME_DEF_STMT (off); |
9efe50a4 | 2977 | if (gimple_assign_single_p (def_stmt) |
f6ab81c1 | 2978 | && si->full_string_p |
2979 | && operand_equal_p (si->nonzero_chars, | |
2980 | gimple_assign_rhs1 (def_stmt), 0)) | |
9efe50a4 | 2981 | zsi = zero_length_string (lhs, si); |
2982 | } | |
2983 | if (zsi != NULL | |
2984 | && si->endptr != NULL_TREE | |
2985 | && si->endptr != lhs | |
2986 | && TREE_CODE (si->endptr) == SSA_NAME) | |
2987 | { | |
2988 | enum tree_code rhs_code | |
2989 | = useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (si->endptr)) | |
2990 | ? SSA_NAME : NOP_EXPR; | |
806413d2 | 2991 | gimple_assign_set_rhs_with_ops (gsi, rhs_code, si->endptr); |
9efe50a4 | 2992 | gcc_assert (gsi_stmt (*gsi) == stmt); |
2993 | update_stmt (stmt); | |
2994 | } | |
2995 | } | |
2996 | ||
98ddbc5b | 2997 | /* If RHS, either directly or indirectly, refers to a string of constant |
2998 | length, return it. Otherwise return a negative value. */ | |
2999 | ||
3000 | static HOST_WIDE_INT | |
3001 | get_string_cst_length (tree rhs) | |
fd31730d | 3002 | { |
3003 | if (TREE_CODE (rhs) == MEM_REF | |
3004 | && integer_zerop (TREE_OPERAND (rhs, 1))) | |
3005 | { | |
98ddbc5b | 3006 | rhs = TREE_OPERAND (rhs, 0); |
fd31730d | 3007 | if (TREE_CODE (rhs) == ADDR_EXPR) |
c004a601 | 3008 | { |
98ddbc5b | 3009 | tree rhs_addr = rhs; |
3010 | ||
c004a601 | 3011 | rhs = TREE_OPERAND (rhs, 0); |
3012 | if (TREE_CODE (rhs) != STRING_CST) | |
3013 | { | |
3014 | int idx = get_stridx (rhs_addr); | |
3015 | if (idx > 0) | |
3016 | { | |
3017 | strinfo *si = get_strinfo (idx); | |
98ddbc5b | 3018 | if (si |
3019 | && si->full_string_p | |
3020 | && tree_fits_shwi_p (si->nonzero_chars)) | |
c004a601 | 3021 | return tree_to_shwi (si->nonzero_chars); |
3022 | } | |
3023 | } | |
3024 | } | |
3025 | } | |
3026 | ||
3027 | if (TREE_CODE (rhs) == VAR_DECL | |
3028 | && TREE_READONLY (rhs)) | |
3029 | rhs = DECL_INITIAL (rhs); | |
3030 | ||
3031 | if (rhs && TREE_CODE (rhs) == STRING_CST) | |
98ddbc5b | 3032 | return strlen (TREE_STRING_POINTER (rhs)); |
fd31730d | 3033 | |
c004a601 | 3034 | return -1; |
fd31730d | 3035 | } |
3036 | ||
9efe50a4 | 3037 | /* Handle a single character store. */ |
3038 | ||
3039 | static bool | |
3040 | handle_char_store (gimple_stmt_iterator *gsi) | |
3041 | { | |
3042 | int idx = -1; | |
04009ada | 3043 | strinfo *si = NULL; |
42acab1c | 3044 | gimple *stmt = gsi_stmt (*gsi); |
9efe50a4 | 3045 | tree ssaname = NULL_TREE, lhs = gimple_assign_lhs (stmt); |
f6ab81c1 | 3046 | tree rhs = gimple_assign_rhs1 (stmt); |
3047 | unsigned HOST_WIDE_INT offset = 0; | |
9efe50a4 | 3048 | |
3049 | if (TREE_CODE (lhs) == MEM_REF | |
3050 | && TREE_CODE (TREE_OPERAND (lhs, 0)) == SSA_NAME) | |
3051 | { | |
f6ab81c1 | 3052 | tree mem_offset = TREE_OPERAND (lhs, 1); |
3053 | if (tree_fits_uhwi_p (mem_offset)) | |
9efe50a4 | 3054 | { |
f6ab81c1 | 3055 | /* Get the strinfo for the base, and use it if it starts with at |
3056 | least OFFSET nonzero characters. This is trivially true if | |
3057 | OFFSET is zero. */ | |
3058 | offset = tree_to_uhwi (mem_offset); | |
3059 | idx = get_stridx (TREE_OPERAND (lhs, 0)); | |
3060 | if (idx > 0) | |
3061 | si = get_strinfo (idx); | |
3062 | if (offset == 0) | |
3063 | ssaname = TREE_OPERAND (lhs, 0); | |
3064 | else if (si == NULL || compare_nonzero_chars (si, offset) < 0) | |
3065 | return true; | |
9efe50a4 | 3066 | } |
3067 | } | |
3068 | else | |
f6ab81c1 | 3069 | { |
3070 | idx = get_addr_stridx (lhs, NULL_TREE, &offset); | |
3071 | if (idx > 0) | |
3072 | si = get_strinfo (idx); | |
3073 | } | |
9efe50a4 | 3074 | |
f6ab81c1 | 3075 | bool storing_zero_p = initializer_zerop (rhs); |
3076 | bool storing_nonzero_p = (!storing_zero_p | |
3077 | && TREE_CODE (rhs) == INTEGER_CST | |
3078 | && integer_nonzerop (rhs)); | |
98ddbc5b | 3079 | /* Set to the length of the string being assigned if known. */ |
3080 | HOST_WIDE_INT rhslen; | |
f6ab81c1 | 3081 | |
3082 | if (si != NULL) | |
9efe50a4 | 3083 | { |
f6ab81c1 | 3084 | int cmp = compare_nonzero_chars (si, offset); |
3085 | gcc_assert (offset == 0 || cmp >= 0); | |
3086 | if (storing_zero_p && cmp == 0 && si->full_string_p) | |
9efe50a4 | 3087 | { |
f6ab81c1 | 3088 | /* When overwriting a '\0' with a '\0', the store can be removed |
3089 | if we know it has been stored in the current function. */ | |
3090 | if (!stmt_could_throw_p (stmt) && si->writable) | |
9efe50a4 | 3091 | { |
f6ab81c1 | 3092 | unlink_stmt_vdef (stmt); |
3093 | release_defs (stmt); | |
3094 | gsi_remove (gsi, true); | |
3095 | return false; | |
9efe50a4 | 3096 | } |
3097 | else | |
f6ab81c1 | 3098 | { |
3099 | si->writable = true; | |
3100 | gsi_next (gsi); | |
3101 | return false; | |
3102 | } | |
9efe50a4 | 3103 | } |
f6ab81c1 | 3104 | /* If si->nonzero_chars > OFFSET, we aren't overwriting '\0', |
1390d90a | 3105 | and if we aren't storing '\0', we know that the length of the |
3106 | string and any other zero terminated string in memory remains | |
3107 | the same. In that case we move to the next gimple statement and | |
3108 | return to signal the caller that it shouldn't invalidate anything. | |
3109 | ||
3110 | This is benefical for cases like: | |
3111 | ||
3112 | char p[20]; | |
3113 | void foo (char *q) | |
3114 | { | |
3115 | strcpy (p, "foobar"); | |
3116 | size_t len = strlen (p); // This can be optimized into 6 | |
3117 | size_t len2 = strlen (q); // This has to be computed | |
3118 | p[0] = 'X'; | |
3119 | size_t len3 = strlen (p); // This can be optimized into 6 | |
3120 | size_t len4 = strlen (q); // This can be optimized into len2 | |
3121 | bar (len, len2, len3, len4); | |
3122 | } | |
3123 | */ | |
f6ab81c1 | 3124 | else if (storing_nonzero_p && cmp > 0) |
1390d90a | 3125 | { |
3126 | gsi_next (gsi); | |
3127 | return false; | |
3128 | } | |
f6ab81c1 | 3129 | else if (storing_zero_p || storing_nonzero_p || (offset != 0 && cmp > 0)) |
3130 | { | |
3131 | /* When storing_nonzero_p, we know that the string now starts | |
3132 | with OFFSET + 1 nonzero characters, but don't know whether | |
3133 | there's a following nul terminator. | |
3134 | ||
3135 | When storing_zero_p, we know that the string is now OFFSET | |
3136 | characters long. | |
3137 | ||
3138 | Otherwise, we're storing an unknown value at offset OFFSET, | |
3139 | so need to clip the nonzero_chars to OFFSET. */ | |
3140 | location_t loc = gimple_location (stmt); | |
3141 | tree oldlen = si->nonzero_chars; | |
3142 | if (cmp == 0 && si->full_string_p) | |
3143 | /* We're overwriting the nul terminator with a nonzero or | |
3144 | unknown character. If the previous stmt was a memcpy, | |
3145 | its length may be decreased. */ | |
3146 | adjust_last_stmt (si, stmt, false); | |
3147 | si = unshare_strinfo (si); | |
3148 | if (storing_nonzero_p) | |
3149 | si->nonzero_chars = build_int_cst (size_type_node, offset + 1); | |
3150 | else | |
3151 | si->nonzero_chars = build_int_cst (size_type_node, offset); | |
3152 | si->full_string_p = storing_zero_p; | |
3153 | if (storing_zero_p | |
3154 | && ssaname | |
3155 | && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ssaname)) | |
3156 | si->endptr = ssaname; | |
3157 | else | |
3158 | si->endptr = NULL; | |
3159 | si->next = 0; | |
3160 | si->stmt = NULL; | |
3161 | si->writable = true; | |
3162 | si->dont_invalidate = true; | |
3163 | if (oldlen) | |
3164 | { | |
3165 | tree adj = fold_build2_loc (loc, MINUS_EXPR, size_type_node, | |
3166 | si->nonzero_chars, oldlen); | |
3167 | adjust_related_strinfos (loc, si, adj); | |
3168 | } | |
3169 | else | |
3170 | si->prev = 0; | |
3171 | } | |
9efe50a4 | 3172 | } |
f6ab81c1 | 3173 | else if (idx == 0 && (storing_zero_p || storing_nonzero_p)) |
9efe50a4 | 3174 | { |
3175 | if (ssaname) | |
f6ab81c1 | 3176 | idx = new_stridx (ssaname); |
9efe50a4 | 3177 | else |
f6ab81c1 | 3178 | idx = new_addr_stridx (lhs); |
3179 | if (idx != 0) | |
9efe50a4 | 3180 | { |
f6ab81c1 | 3181 | tree ptr = (ssaname ? ssaname : build_fold_addr_expr (lhs)); |
3182 | tree len = storing_nonzero_p ? size_one_node : size_zero_node; | |
3183 | si = new_strinfo (ptr, idx, len, storing_zero_p); | |
3184 | set_strinfo (idx, si); | |
3185 | if (storing_zero_p | |
3186 | && ssaname | |
3187 | && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ssaname)) | |
3188 | si->endptr = ssaname; | |
3189 | si->dont_invalidate = true; | |
3190 | si->writable = true; | |
9efe50a4 | 3191 | } |
9efe50a4 | 3192 | } |
2047c70c | 3193 | else if (idx == 0 |
98ddbc5b | 3194 | && (rhslen = get_string_cst_length (gimple_assign_rhs1 (stmt))) >= 0 |
2047c70c | 3195 | && ssaname == NULL_TREE |
3196 | && TREE_CODE (TREE_TYPE (lhs)) == ARRAY_TYPE) | |
3197 | { | |
2047c70c | 3198 | HOST_WIDE_INT a = int_size_in_bytes (TREE_TYPE (lhs)); |
c004a601 | 3199 | if (a > 0 && (unsigned HOST_WIDE_INT) a > (unsigned HOST_WIDE_INT) rhslen) |
2047c70c | 3200 | { |
3201 | int idx = new_addr_stridx (lhs); | |
3202 | if (idx != 0) | |
3203 | { | |
3204 | si = new_strinfo (build_fold_addr_expr (lhs), idx, | |
c004a601 | 3205 | build_int_cst (size_type_node, rhslen), true); |
2047c70c | 3206 | set_strinfo (idx, si); |
3207 | si->dont_invalidate = true; | |
3208 | } | |
3209 | } | |
3210 | } | |
9efe50a4 | 3211 | |
f6ab81c1 | 3212 | if (si != NULL && offset == 0 && storing_zero_p) |
9efe50a4 | 3213 | { |
3214 | /* Allow adjust_last_stmt to remove it if the stored '\0' | |
3215 | is immediately overwritten. */ | |
3216 | laststmt.stmt = stmt; | |
3217 | laststmt.len = build_int_cst (size_type_node, 1); | |
3218 | laststmt.stridx = si->idx; | |
3219 | } | |
3220 | return true; | |
3221 | } | |
3222 | ||
6384df06 | 3223 | /* Try to fold strstr (s, t) eq/ne s to strncmp (s, t, strlen (t)) eq/ne 0. */ |
177394f7 | 3224 | |
3225 | static void | |
6384df06 | 3226 | fold_strstr_to_strncmp (tree rhs1, tree rhs2, gimple *stmt) |
177394f7 | 3227 | { |
3228 | if (TREE_CODE (rhs1) != SSA_NAME | |
3229 | || TREE_CODE (rhs2) != SSA_NAME) | |
3230 | return; | |
3231 | ||
3232 | gimple *call_stmt = NULL; | |
3233 | for (int pass = 0; pass < 2; pass++) | |
3234 | { | |
3235 | gimple *g = SSA_NAME_DEF_STMT (rhs1); | |
3236 | if (gimple_call_builtin_p (g, BUILT_IN_STRSTR) | |
3237 | && has_single_use (rhs1) | |
3238 | && gimple_call_arg (g, 0) == rhs2) | |
3239 | { | |
3240 | call_stmt = g; | |
3241 | break; | |
3242 | } | |
3243 | std::swap (rhs1, rhs2); | |
3244 | } | |
3245 | ||
3246 | if (call_stmt) | |
3247 | { | |
3248 | tree arg0 = gimple_call_arg (call_stmt, 0); | |
3249 | ||
3250 | if (arg0 == rhs2) | |
3251 | { | |
3252 | tree arg1 = gimple_call_arg (call_stmt, 1); | |
3253 | tree arg1_len = NULL_TREE; | |
3254 | int idx = get_stridx (arg1); | |
3255 | ||
3256 | if (idx) | |
3257 | { | |
3258 | if (idx < 0) | |
3259 | arg1_len = build_int_cst (size_type_node, ~idx); | |
3260 | else | |
3261 | { | |
3262 | strinfo *si = get_strinfo (idx); | |
3263 | if (si) | |
3264 | arg1_len = get_string_length (si); | |
3265 | } | |
3266 | } | |
3267 | ||
3268 | if (arg1_len != NULL_TREE) | |
3269 | { | |
3270 | gimple_stmt_iterator gsi = gsi_for_stmt (call_stmt); | |
6384df06 | 3271 | tree strncmp_decl = builtin_decl_explicit (BUILT_IN_STRNCMP); |
1abfa5b1 | 3272 | |
3273 | if (!is_gimple_val (arg1_len)) | |
3274 | { | |
3275 | tree arg1_len_tmp = make_ssa_name (TREE_TYPE (arg1_len)); | |
3276 | gassign *arg1_stmt = gimple_build_assign (arg1_len_tmp, | |
3277 | arg1_len); | |
3278 | gsi_insert_before (&gsi, arg1_stmt, GSI_SAME_STMT); | |
3279 | arg1_len = arg1_len_tmp; | |
3280 | } | |
3281 | ||
6384df06 | 3282 | gcall *strncmp_call = gimple_build_call (strncmp_decl, 3, |
177394f7 | 3283 | arg0, arg1, arg1_len); |
6384df06 | 3284 | tree strncmp_lhs = make_ssa_name (integer_type_node); |
3285 | gimple_set_vuse (strncmp_call, gimple_vuse (call_stmt)); | |
3286 | gimple_call_set_lhs (strncmp_call, strncmp_lhs); | |
177394f7 | 3287 | gsi_remove (&gsi, true); |
6384df06 | 3288 | gsi_insert_before (&gsi, strncmp_call, GSI_SAME_STMT); |
3289 | tree zero = build_zero_cst (TREE_TYPE (strncmp_lhs)); | |
177394f7 | 3290 | |
3291 | if (is_gimple_assign (stmt)) | |
3292 | { | |
3293 | if (gimple_assign_rhs_code (stmt) == COND_EXPR) | |
3294 | { | |
3295 | tree cond = gimple_assign_rhs1 (stmt); | |
6384df06 | 3296 | TREE_OPERAND (cond, 0) = strncmp_lhs; |
177394f7 | 3297 | TREE_OPERAND (cond, 1) = zero; |
3298 | } | |
3299 | else | |
3300 | { | |
6384df06 | 3301 | gimple_assign_set_rhs1 (stmt, strncmp_lhs); |
177394f7 | 3302 | gimple_assign_set_rhs2 (stmt, zero); |
3303 | } | |
3304 | } | |
3305 | else | |
3306 | { | |
3307 | gcond *cond = as_a<gcond *> (stmt); | |
6384df06 | 3308 | gimple_cond_set_lhs (cond, strncmp_lhs); |
177394f7 | 3309 | gimple_cond_set_rhs (cond, zero); |
3310 | } | |
3311 | update_stmt (stmt); | |
3312 | } | |
3313 | } | |
3314 | } | |
3315 | } | |
3316 | ||
e6a18b5a | 3317 | /* Attempt to check for validity of the performed access a single statement |
7626097e | 3318 | at *GSI using string length knowledge, and to optimize it. |
3319 | If the given basic block needs clean-up of EH, CLEANUP_EH is set to | |
3320 | true. */ | |
9efe50a4 | 3321 | |
3322 | static bool | |
7626097e | 3323 | strlen_check_and_optimize_stmt (gimple_stmt_iterator *gsi, bool *cleanup_eh) |
9efe50a4 | 3324 | { |
42acab1c | 3325 | gimple *stmt = gsi_stmt (*gsi); |
9efe50a4 | 3326 | |
3327 | if (is_gimple_call (stmt)) | |
3328 | { | |
3329 | tree callee = gimple_call_fndecl (stmt); | |
ec15ec36 | 3330 | if (valid_builtin_call (stmt)) |
9efe50a4 | 3331 | switch (DECL_FUNCTION_CODE (callee)) |
3332 | { | |
3333 | case BUILT_IN_STRLEN: | |
3334 | handle_builtin_strlen (gsi); | |
3335 | break; | |
3336 | case BUILT_IN_STRCHR: | |
3337 | handle_builtin_strchr (gsi); | |
3338 | break; | |
3339 | case BUILT_IN_STRCPY: | |
3340 | case BUILT_IN_STRCPY_CHK: | |
3341 | case BUILT_IN_STPCPY: | |
3342 | case BUILT_IN_STPCPY_CHK: | |
3343 | handle_builtin_strcpy (DECL_FUNCTION_CODE (callee), gsi); | |
3344 | break; | |
d8aad786 | 3345 | |
3346 | case BUILT_IN_STRNCAT: | |
3347 | case BUILT_IN_STRNCAT_CHK: | |
3348 | handle_builtin_strncat (DECL_FUNCTION_CODE (callee), gsi); | |
3349 | break; | |
3350 | ||
3351 | case BUILT_IN_STPNCPY: | |
3352 | case BUILT_IN_STPNCPY_CHK: | |
3353 | case BUILT_IN_STRNCPY: | |
3354 | case BUILT_IN_STRNCPY_CHK: | |
3355 | handle_builtin_stxncpy (DECL_FUNCTION_CODE (callee), gsi); | |
3356 | break; | |
3357 | ||
9efe50a4 | 3358 | case BUILT_IN_MEMCPY: |
3359 | case BUILT_IN_MEMCPY_CHK: | |
3360 | case BUILT_IN_MEMPCPY: | |
3361 | case BUILT_IN_MEMPCPY_CHK: | |
3362 | handle_builtin_memcpy (DECL_FUNCTION_CODE (callee), gsi); | |
3363 | break; | |
3364 | case BUILT_IN_STRCAT: | |
3365 | case BUILT_IN_STRCAT_CHK: | |
3366 | handle_builtin_strcat (DECL_FUNCTION_CODE (callee), gsi); | |
3367 | break; | |
9f15ed6e | 3368 | case BUILT_IN_MALLOC: |
3369 | case BUILT_IN_CALLOC: | |
3370 | handle_builtin_malloc (DECL_FUNCTION_CODE (callee), gsi); | |
3371 | break; | |
3372 | case BUILT_IN_MEMSET: | |
72dbc21d | 3373 | if (handle_builtin_memset (gsi)) |
9f15ed6e | 3374 | return false; |
3375 | break; | |
3e346f54 | 3376 | case BUILT_IN_MEMCMP: |
72dbc21d | 3377 | if (handle_builtin_memcmp (gsi)) |
3378 | return false; | |
3379 | break; | |
3380 | case BUILT_IN_STRCMP: | |
3381 | case BUILT_IN_STRNCMP: | |
3382 | if (handle_builtin_string_cmp (gsi)) | |
3e346f54 | 3383 | return false; |
3384 | break; | |
9efe50a4 | 3385 | default: |
3386 | break; | |
3387 | } | |
3388 | } | |
cb65bd7c | 3389 | else if (is_gimple_assign (stmt) && !gimple_clobber_p (stmt)) |
9efe50a4 | 3390 | { |
3391 | tree lhs = gimple_assign_lhs (stmt); | |
3392 | ||
3393 | if (TREE_CODE (lhs) == SSA_NAME && POINTER_TYPE_P (TREE_TYPE (lhs))) | |
3394 | { | |
3395 | if (gimple_assign_single_p (stmt) | |
3396 | || (gimple_assign_cast_p (stmt) | |
3397 | && POINTER_TYPE_P (TREE_TYPE (gimple_assign_rhs1 (stmt))))) | |
3398 | { | |
3399 | int idx = get_stridx (gimple_assign_rhs1 (stmt)); | |
f1f41a6c | 3400 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] = idx; |
9efe50a4 | 3401 | } |
3402 | else if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR) | |
3403 | handle_pointer_plus (gsi); | |
3404 | } | |
177394f7 | 3405 | else if (TREE_CODE (lhs) == SSA_NAME && INTEGRAL_TYPE_P (TREE_TYPE (lhs))) |
3406 | { | |
3407 | enum tree_code code = gimple_assign_rhs_code (stmt); | |
3408 | if (code == COND_EXPR) | |
3409 | { | |
3410 | tree cond = gimple_assign_rhs1 (stmt); | |
3411 | enum tree_code cond_code = TREE_CODE (cond); | |
3412 | ||
3413 | if (cond_code == EQ_EXPR || cond_code == NE_EXPR) | |
6384df06 | 3414 | fold_strstr_to_strncmp (TREE_OPERAND (cond, 0), |
3415 | TREE_OPERAND (cond, 1), stmt); | |
177394f7 | 3416 | } |
3417 | else if (code == EQ_EXPR || code == NE_EXPR) | |
6384df06 | 3418 | fold_strstr_to_strncmp (gimple_assign_rhs1 (stmt), |
3419 | gimple_assign_rhs2 (stmt), stmt); | |
8938f069 | 3420 | else if (gimple_assign_load_p (stmt) |
3421 | && TREE_CODE (TREE_TYPE (lhs)) == INTEGER_TYPE | |
3422 | && TYPE_MODE (TREE_TYPE (lhs)) == TYPE_MODE (char_type_node) | |
3423 | && (TYPE_PRECISION (TREE_TYPE (lhs)) | |
3424 | == TYPE_PRECISION (char_type_node)) | |
3425 | && !gimple_has_volatile_ops (stmt)) | |
3426 | { | |
3427 | tree off = integer_zero_node; | |
3428 | unsigned HOST_WIDE_INT coff = 0; | |
edcf99db | 3429 | int idx = 0; |
8938f069 | 3430 | tree rhs1 = gimple_assign_rhs1 (stmt); |
3431 | if (code == MEM_REF) | |
3432 | { | |
3433 | idx = get_stridx (TREE_OPERAND (rhs1, 0)); | |
edcf99db | 3434 | if (idx > 0) |
3435 | { | |
3436 | strinfo *si = get_strinfo (idx); | |
3437 | if (si | |
3438 | && si->nonzero_chars | |
3439 | && TREE_CODE (si->nonzero_chars) == INTEGER_CST | |
3440 | && (wi::to_widest (si->nonzero_chars) | |
3441 | >= wi::to_widest (off))) | |
3442 | off = TREE_OPERAND (rhs1, 1); | |
3443 | else | |
3444 | /* This case is not useful. See if get_addr_stridx | |
3445 | returns something usable. */ | |
3446 | idx = 0; | |
3447 | } | |
8938f069 | 3448 | } |
edcf99db | 3449 | if (idx <= 0) |
8938f069 | 3450 | idx = get_addr_stridx (rhs1, NULL_TREE, &coff); |
3451 | if (idx > 0) | |
3452 | { | |
3453 | strinfo *si = get_strinfo (idx); | |
3454 | if (si | |
3455 | && si->nonzero_chars | |
3456 | && TREE_CODE (si->nonzero_chars) == INTEGER_CST) | |
3457 | { | |
3458 | widest_int w1 = wi::to_widest (si->nonzero_chars); | |
3459 | widest_int w2 = wi::to_widest (off) + coff; | |
3460 | if (w1 == w2 | |
3461 | && si->full_string_p) | |
3462 | { | |
7626097e | 3463 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) |
3464 | { | |
3465 | fprintf (dump_file, "Optimizing: "); | |
3466 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
3467 | } | |
3468 | ||
8938f069 | 3469 | /* Reading the final '\0' character. */ |
3470 | tree zero = build_int_cst (TREE_TYPE (lhs), 0); | |
3471 | gimple_set_vuse (stmt, NULL_TREE); | |
3472 | gimple_assign_set_rhs_from_tree (gsi, zero); | |
7626097e | 3473 | *cleanup_eh |
3474 | |= maybe_clean_or_replace_eh_stmt (stmt, | |
3475 | gsi_stmt (*gsi)); | |
3476 | stmt = gsi_stmt (*gsi); | |
3477 | update_stmt (stmt); | |
3478 | ||
3479 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
3480 | { | |
3481 | fprintf (dump_file, "into: "); | |
3482 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
3483 | } | |
8938f069 | 3484 | } |
3485 | else if (w1 > w2) | |
3486 | { | |
3487 | /* Reading a character before the final '\0' | |
3488 | character. Just set the value range to ~[0, 0] | |
3489 | if we don't have anything better. */ | |
3490 | wide_int min, max; | |
3491 | tree type = TREE_TYPE (lhs); | |
3492 | enum value_range_type vr | |
3493 | = get_range_info (lhs, &min, &max); | |
3494 | if (vr == VR_VARYING | |
3495 | || (vr == VR_RANGE | |
3496 | && min == wi::min_value (TYPE_PRECISION (type), | |
3497 | TYPE_SIGN (type)) | |
3498 | && max == wi::max_value (TYPE_PRECISION (type), | |
3499 | TYPE_SIGN (type)))) | |
3500 | set_range_info (lhs, VR_ANTI_RANGE, | |
3501 | wi::zero (TYPE_PRECISION (type)), | |
3502 | wi::zero (TYPE_PRECISION (type))); | |
3503 | } | |
3504 | } | |
3505 | } | |
3506 | } | |
d8aad786 | 3507 | |
0c45740b | 3508 | if (strlen_to_stridx) |
3509 | { | |
3510 | tree rhs1 = gimple_assign_rhs1 (stmt); | |
3511 | if (stridx_strlenloc *ps = strlen_to_stridx->get (rhs1)) | |
3512 | strlen_to_stridx->put (lhs, stridx_strlenloc (*ps)); | |
3513 | } | |
177394f7 | 3514 | } |
3515 | else if (TREE_CODE (lhs) != SSA_NAME && !TREE_SIDE_EFFECTS (lhs)) | |
9efe50a4 | 3516 | { |
3517 | tree type = TREE_TYPE (lhs); | |
3518 | if (TREE_CODE (type) == ARRAY_TYPE) | |
3519 | type = TREE_TYPE (type); | |
3520 | if (TREE_CODE (type) == INTEGER_TYPE | |
3521 | && TYPE_MODE (type) == TYPE_MODE (char_type_node) | |
3522 | && TYPE_PRECISION (type) == TYPE_PRECISION (char_type_node)) | |
3523 | { | |
3524 | if (! handle_char_store (gsi)) | |
3525 | return false; | |
3526 | } | |
3527 | } | |
3528 | } | |
177394f7 | 3529 | else if (gcond *cond = dyn_cast<gcond *> (stmt)) |
3530 | { | |
3531 | enum tree_code code = gimple_cond_code (cond); | |
3532 | if (code == EQ_EXPR || code == NE_EXPR) | |
6384df06 | 3533 | fold_strstr_to_strncmp (gimple_cond_lhs (stmt), |
3534 | gimple_cond_rhs (stmt), stmt); | |
177394f7 | 3535 | } |
9efe50a4 | 3536 | |
3537 | if (gimple_vdef (stmt)) | |
3538 | maybe_invalidate (stmt); | |
3539 | return true; | |
3540 | } | |
3541 | ||
3542 | /* Recursively call maybe_invalidate on stmts that might be executed | |
3543 | in between dombb and current bb and that contain a vdef. Stop when | |
3544 | *count stmts are inspected, or if the whole strinfo vector has | |
3545 | been invalidated. */ | |
3546 | ||
3547 | static void | |
42acab1c | 3548 | do_invalidate (basic_block dombb, gimple *phi, bitmap visited, int *count) |
9efe50a4 | 3549 | { |
3550 | unsigned int i, n = gimple_phi_num_args (phi); | |
3551 | ||
3552 | for (i = 0; i < n; i++) | |
3553 | { | |
3554 | tree vuse = gimple_phi_arg_def (phi, i); | |
42acab1c | 3555 | gimple *stmt = SSA_NAME_DEF_STMT (vuse); |
9efe50a4 | 3556 | basic_block bb = gimple_bb (stmt); |
3557 | if (bb == NULL | |
3558 | || bb == dombb | |
3559 | || !bitmap_set_bit (visited, bb->index) | |
3560 | || !dominated_by_p (CDI_DOMINATORS, bb, dombb)) | |
3561 | continue; | |
3562 | while (1) | |
3563 | { | |
3564 | if (gimple_code (stmt) == GIMPLE_PHI) | |
3565 | { | |
3566 | do_invalidate (dombb, stmt, visited, count); | |
3567 | if (*count == 0) | |
3568 | return; | |
3569 | break; | |
3570 | } | |
3571 | if (--*count == 0) | |
3572 | return; | |
3573 | if (!maybe_invalidate (stmt)) | |
3574 | { | |
3575 | *count = 0; | |
3576 | return; | |
3577 | } | |
3578 | vuse = gimple_vuse (stmt); | |
3579 | stmt = SSA_NAME_DEF_STMT (vuse); | |
3580 | if (gimple_bb (stmt) != bb) | |
3581 | { | |
3582 | bb = gimple_bb (stmt); | |
3583 | if (bb == NULL | |
3584 | || bb == dombb | |
3585 | || !bitmap_set_bit (visited, bb->index) | |
3586 | || !dominated_by_p (CDI_DOMINATORS, bb, dombb)) | |
3587 | break; | |
3588 | } | |
3589 | } | |
3590 | } | |
3591 | } | |
3592 | ||
54c91640 | 3593 | class strlen_dom_walker : public dom_walker |
3594 | { | |
3595 | public: | |
7626097e | 3596 | strlen_dom_walker (cdi_direction direction) |
3597 | : dom_walker (direction), m_cleanup_cfg (false) | |
3598 | {} | |
54c91640 | 3599 | |
96752458 | 3600 | virtual edge before_dom_children (basic_block); |
54c91640 | 3601 | virtual void after_dom_children (basic_block); |
7626097e | 3602 | |
3603 | /* Flag that will trigger TODO_cleanup_cfg to be returned in strlen | |
3604 | execute function. */ | |
3605 | bool m_cleanup_cfg; | |
54c91640 | 3606 | }; |
3607 | ||
9efe50a4 | 3608 | /* Callback for walk_dominator_tree. Attempt to optimize various |
d96281b8 | 3609 | string ops by remembering string lengths pointed by pointer SSA_NAMEs. */ |
9efe50a4 | 3610 | |
96752458 | 3611 | edge |
54c91640 | 3612 | strlen_dom_walker::before_dom_children (basic_block bb) |
9efe50a4 | 3613 | { |
9efe50a4 | 3614 | basic_block dombb = get_immediate_dominator (CDI_DOMINATORS, bb); |
3615 | ||
3616 | if (dombb == NULL) | |
3617 | stridx_to_strinfo = NULL; | |
3618 | else | |
3619 | { | |
04009ada | 3620 | stridx_to_strinfo = ((vec<strinfo *, va_heap, vl_embed> *) dombb->aux); |
9efe50a4 | 3621 | if (stridx_to_strinfo) |
3622 | { | |
1a91d914 | 3623 | for (gphi_iterator gsi = gsi_start_phis (bb); !gsi_end_p (gsi); |
3624 | gsi_next (&gsi)) | |
9efe50a4 | 3625 | { |
1a91d914 | 3626 | gphi *phi = gsi.phi (); |
7c782c9b | 3627 | if (virtual_operand_p (gimple_phi_result (phi))) |
9efe50a4 | 3628 | { |
3629 | bitmap visited = BITMAP_ALLOC (NULL); | |
3630 | int count_vdef = 100; | |
3631 | do_invalidate (dombb, phi, visited, &count_vdef); | |
3632 | BITMAP_FREE (visited); | |
6c6bd170 | 3633 | if (count_vdef == 0) |
3634 | { | |
3635 | /* If there were too many vdefs in between immediate | |
3636 | dominator and current bb, invalidate everything. | |
3637 | If stridx_to_strinfo has been unshared, we need | |
3638 | to free it, otherwise just set it to NULL. */ | |
3639 | if (!strinfo_shared ()) | |
3640 | { | |
3641 | unsigned int i; | |
04009ada | 3642 | strinfo *si; |
6c6bd170 | 3643 | |
3644 | for (i = 1; | |
3645 | vec_safe_iterate (stridx_to_strinfo, i, &si); | |
3646 | ++i) | |
3647 | { | |
3648 | free_strinfo (si); | |
3649 | (*stridx_to_strinfo)[i] = NULL; | |
3650 | } | |
3651 | } | |
3652 | else | |
3653 | stridx_to_strinfo = NULL; | |
3654 | } | |
9efe50a4 | 3655 | break; |
3656 | } | |
3657 | } | |
3658 | } | |
3659 | } | |
3660 | ||
3661 | /* If all PHI arguments have the same string index, the PHI result | |
3662 | has it as well. */ | |
1a91d914 | 3663 | for (gphi_iterator gsi = gsi_start_phis (bb); !gsi_end_p (gsi); |
3664 | gsi_next (&gsi)) | |
9efe50a4 | 3665 | { |
1a91d914 | 3666 | gphi *phi = gsi.phi (); |
9efe50a4 | 3667 | tree result = gimple_phi_result (phi); |
7c782c9b | 3668 | if (!virtual_operand_p (result) && POINTER_TYPE_P (TREE_TYPE (result))) |
9efe50a4 | 3669 | { |
3670 | int idx = get_stridx (gimple_phi_arg_def (phi, 0)); | |
3671 | if (idx != 0) | |
3672 | { | |
3673 | unsigned int i, n = gimple_phi_num_args (phi); | |
3674 | for (i = 1; i < n; i++) | |
3675 | if (idx != get_stridx (gimple_phi_arg_def (phi, i))) | |
3676 | break; | |
3677 | if (i == n) | |
f1f41a6c | 3678 | ssa_ver_to_stridx[SSA_NAME_VERSION (result)] = idx; |
9efe50a4 | 3679 | } |
3680 | } | |
3681 | } | |
3682 | ||
7626097e | 3683 | bool cleanup_eh = false; |
3684 | ||
9efe50a4 | 3685 | /* Attempt to optimize individual statements. */ |
1a91d914 | 3686 | for (gimple_stmt_iterator gsi = gsi_start_bb (bb); !gsi_end_p (gsi); ) |
7626097e | 3687 | if (strlen_check_and_optimize_stmt (&gsi, &cleanup_eh)) |
9efe50a4 | 3688 | gsi_next (&gsi); |
3689 | ||
7626097e | 3690 | if (cleanup_eh && gimple_purge_dead_eh_edges (bb)) |
3691 | m_cleanup_cfg = true; | |
3692 | ||
9efe50a4 | 3693 | bb->aux = stridx_to_strinfo; |
f1f41a6c | 3694 | if (vec_safe_length (stridx_to_strinfo) && !strinfo_shared ()) |
04009ada | 3695 | (*stridx_to_strinfo)[0] = (strinfo *) bb; |
96752458 | 3696 | return NULL; |
9efe50a4 | 3697 | } |
3698 | ||
3699 | /* Callback for walk_dominator_tree. Free strinfo vector if it is | |
3700 | owned by the current bb, clear bb->aux. */ | |
3701 | ||
54c91640 | 3702 | void |
3703 | strlen_dom_walker::after_dom_children (basic_block bb) | |
9efe50a4 | 3704 | { |
3705 | if (bb->aux) | |
3706 | { | |
04009ada | 3707 | stridx_to_strinfo = ((vec<strinfo *, va_heap, vl_embed> *) bb->aux); |
f1f41a6c | 3708 | if (vec_safe_length (stridx_to_strinfo) |
04009ada | 3709 | && (*stridx_to_strinfo)[0] == (strinfo *) bb) |
9efe50a4 | 3710 | { |
3711 | unsigned int i; | |
04009ada | 3712 | strinfo *si; |
9efe50a4 | 3713 | |
f1f41a6c | 3714 | for (i = 1; vec_safe_iterate (stridx_to_strinfo, i, &si); ++i) |
9efe50a4 | 3715 | free_strinfo (si); |
f1f41a6c | 3716 | vec_free (stridx_to_strinfo); |
9efe50a4 | 3717 | } |
3718 | bb->aux = NULL; | |
3719 | } | |
3720 | } | |
3721 | ||
3722 | /* Main entry point. */ | |
3723 | ||
cbe8bda8 | 3724 | namespace { |
3725 | ||
3726 | const pass_data pass_data_strlen = | |
9efe50a4 | 3727 | { |
cbe8bda8 | 3728 | GIMPLE_PASS, /* type */ |
3729 | "strlen", /* name */ | |
3730 | OPTGROUP_NONE, /* optinfo_flags */ | |
cbe8bda8 | 3731 | TV_TREE_STRLEN, /* tv_id */ |
3732 | ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
3733 | 0, /* properties_provided */ | |
3734 | 0, /* properties_destroyed */ | |
3735 | 0, /* todo_flags_start */ | |
8b88439e | 3736 | 0, /* todo_flags_finish */ |
9efe50a4 | 3737 | }; |
cbe8bda8 | 3738 | |
3739 | class pass_strlen : public gimple_opt_pass | |
3740 | { | |
3741 | public: | |
9af5ce0c | 3742 | pass_strlen (gcc::context *ctxt) |
3743 | : gimple_opt_pass (pass_data_strlen, ctxt) | |
cbe8bda8 | 3744 | {} |
3745 | ||
3746 | /* opt_pass methods: */ | |
31315c24 | 3747 | virtual bool gate (function *) { return flag_optimize_strlen != 0; } |
65b0537f | 3748 | virtual unsigned int execute (function *); |
cbe8bda8 | 3749 | |
3750 | }; // class pass_strlen | |
3751 | ||
65b0537f | 3752 | unsigned int |
3753 | pass_strlen::execute (function *fun) | |
3754 | { | |
0c45740b | 3755 | gcc_assert (!strlen_to_stridx); |
3756 | if (warn_stringop_overflow || warn_stringop_truncation) | |
3757 | strlen_to_stridx = new hash_map<tree, stridx_strlenloc> (); | |
3758 | ||
65b0537f | 3759 | ssa_ver_to_stridx.safe_grow_cleared (num_ssa_names); |
3760 | max_stridx = 1; | |
65b0537f | 3761 | |
3762 | calculate_dominance_info (CDI_DOMINATORS); | |
3763 | ||
3764 | /* String length optimization is implemented as a walk of the dominator | |
3765 | tree and a forward walk of statements within each block. */ | |
7626097e | 3766 | strlen_dom_walker walker (CDI_DOMINATORS); |
3767 | walker.walk (fun->cfg->x_entry_block_ptr); | |
65b0537f | 3768 | |
3769 | ssa_ver_to_stridx.release (); | |
a7e0cb97 | 3770 | strinfo_pool.release (); |
c1f445d2 | 3771 | if (decl_to_stridxlist_htab) |
65b0537f | 3772 | { |
3773 | obstack_free (&stridx_obstack, NULL); | |
c1f445d2 | 3774 | delete decl_to_stridxlist_htab; |
3775 | decl_to_stridxlist_htab = NULL; | |
65b0537f | 3776 | } |
3777 | laststmt.stmt = NULL; | |
3778 | laststmt.len = NULL_TREE; | |
3779 | laststmt.stridx = 0; | |
3780 | ||
0c45740b | 3781 | if (strlen_to_stridx) |
3782 | { | |
3783 | strlen_to_stridx->empty (); | |
3784 | delete strlen_to_stridx; | |
3785 | strlen_to_stridx = NULL; | |
3786 | } | |
d8aad786 | 3787 | |
7626097e | 3788 | return walker.m_cleanup_cfg ? TODO_cleanup_cfg : 0; |
65b0537f | 3789 | } |
3790 | ||
cbe8bda8 | 3791 | } // anon namespace |
3792 | ||
3793 | gimple_opt_pass * | |
3794 | make_pass_strlen (gcc::context *ctxt) | |
3795 | { | |
3796 | return new pass_strlen (ctxt); | |
3797 | } |