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8b57bfeb | 1 | /* String length optimization |
99dee823 | 2 | Copyright (C) 2011-2021 Free Software Foundation, Inc. |
8b57bfeb JJ |
3 | Contributed by Jakub Jelinek <jakub@redhat.com> |
4 | ||
5 | This file is part of GCC. | |
6 | ||
7 | GCC is free software; you can redistribute it and/or modify | |
8 | it under the terms of the GNU General Public License as published by | |
9 | the Free Software Foundation; either version 3, or (at your option) | |
10 | any later version. | |
11 | ||
12 | GCC is distributed in the hope that it will be useful, | |
13 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | GNU General Public License for more details. | |
16 | ||
17 | You should have received a copy of the GNU General Public License | |
18 | along with GCC; see the file COPYING3. If not see | |
19 | <http://www.gnu.org/licenses/>. */ | |
20 | ||
21 | #include "config.h" | |
22 | #include "system.h" | |
23 | #include "coretypes.h" | |
c7131fb2 | 24 | #include "backend.h" |
957060b5 | 25 | #include "rtl.h" |
4d648807 | 26 | #include "tree.h" |
c7131fb2 | 27 | #include "gimple.h" |
957060b5 AM |
28 | #include "alloc-pool.h" |
29 | #include "tree-pass.h" | |
c7131fb2 | 30 | #include "ssa.h" |
957060b5 AM |
31 | #include "cgraph.h" |
32 | #include "gimple-pretty-print.h" | |
2a837de2 | 33 | #include "gimple-ssa-warn-access.h" |
cc8bea0a | 34 | #include "gimple-ssa-warn-restrict.h" |
40e23961 | 35 | #include "fold-const.h" |
d8a2d370 | 36 | #include "stor-layout.h" |
2fb9a547 AM |
37 | #include "gimple-fold.h" |
38 | #include "tree-eh.h" | |
45b0be94 | 39 | #include "gimplify.h" |
5be5c238 | 40 | #include "gimple-iterator.h" |
18f429e2 | 41 | #include "gimplify-me.h" |
d8a2d370 | 42 | #include "expr.h" |
fa9544ab | 43 | #include "tree-cfg.h" |
442b4905 | 44 | #include "tree-dfa.h" |
8b57bfeb | 45 | #include "domwalk.h" |
025d57f0 | 46 | #include "tree-ssa-alias.h" |
8b57bfeb | 47 | #include "tree-ssa-propagate.h" |
5d0d5d68 | 48 | #include "tree-ssa-strlen.h" |
910ee068 | 49 | #include "tree-hash-traits.h" |
36b85e43 | 50 | #include "builtins.h" |
2a837de2 | 51 | #include "pointer-query.h" |
e0bd6c9f | 52 | #include "target.h" |
025d57f0 MS |
53 | #include "diagnostic-core.h" |
54 | #include "diagnostic.h" | |
55 | #include "intl.h" | |
56 | #include "attribs.h" | |
6a33d0ff | 57 | #include "calls.h" |
22fca489 MS |
58 | #include "cfgloop.h" |
59 | #include "tree-ssa-loop.h" | |
60 | #include "tree-scalar-evolution.h" | |
22fca489 | 61 | #include "vr-values.h" |
6b8b9596 | 62 | #include "gimple-range.h" |
4e3d3e40 | 63 | #include "tree-ssa.h" |
8b57bfeb JJ |
64 | |
65 | /* A vector indexed by SSA_NAME_VERSION. 0 means unknown, positive value | |
66 | is an index into strinfo vector, negative value stands for | |
67 | string length of a string literal (~strlen). */ | |
9771b263 | 68 | static vec<int> ssa_ver_to_stridx; |
8b57bfeb JJ |
69 | |
70 | /* Number of currently active string indexes plus one. */ | |
71 | static int max_stridx; | |
72 | ||
22fca489 MS |
73 | /* Set to true to optimize, false when just checking. */ |
74 | static bool strlen_optimize; | |
75 | ||
8b57bfeb | 76 | /* String information record. */ |
526ceb68 | 77 | struct strinfo |
8b57bfeb | 78 | { |
e3f9a279 RS |
79 | /* Number of leading characters that are known to be nonzero. This is |
80 | also the length of the string if FULL_STRING_P. | |
81 | ||
82 | The values in a list of related string pointers must be consistent; | |
83 | that is, if strinfo B comes X bytes after strinfo A, it must be | |
84 | the case that A->nonzero_chars == X + B->nonzero_chars. */ | |
85 | tree nonzero_chars; | |
8b57bfeb JJ |
86 | /* Any of the corresponding pointers for querying alias oracle. */ |
87 | tree ptr; | |
ef29b12c | 88 | /* STMT is used for two things: |
862088aa RS |
89 | |
90 | - To record the statement that should be used for delayed length | |
91 | computations. We maintain the invariant that all related strinfos | |
92 | have delayed lengths or none do. | |
93 | ||
ef29b12c MS |
94 | - To record the malloc or calloc call that produced this result |
95 | to optimize away malloc/memset sequences. STMT is reset after | |
96 | a calloc-allocated object has been stored a non-zero value into. */ | |
355fe088 | 97 | gimple *stmt; |
ef29b12c MS |
98 | /* Set to the dynamic allocation statement for the object (alloca, |
99 | calloc, malloc, or VLA). Unlike STMT, once set for a strinfo | |
100 | object, ALLOC doesn't change. */ | |
101 | gimple *alloc; | |
8b57bfeb JJ |
102 | /* Pointer to '\0' if known, if NULL, it can be computed as |
103 | ptr + length. */ | |
104 | tree endptr; | |
105 | /* Reference count. Any changes to strinfo entry possibly shared | |
106 | with dominating basic blocks need unshare_strinfo first, except | |
107 | for dont_invalidate which affects only the immediately next | |
108 | maybe_invalidate. */ | |
109 | int refcount; | |
110 | /* Copy of index. get_strinfo (si->idx) should return si; */ | |
111 | int idx; | |
112 | /* These 3 fields are for chaining related string pointers together. | |
113 | E.g. for | |
114 | bl = strlen (b); dl = strlen (d); strcpy (a, b); c = a + bl; | |
115 | strcpy (c, d); e = c + dl; | |
116 | strinfo(a) -> strinfo(c) -> strinfo(e) | |
117 | All have ->first field equal to strinfo(a)->idx and are doubly | |
118 | chained through prev/next fields. The later strinfos are required | |
119 | to point into the same string with zero or more bytes after | |
120 | the previous pointer and all bytes in between the two pointers | |
121 | must be non-zero. Functions like strcpy or memcpy are supposed | |
122 | to adjust all previous strinfo lengths, but not following strinfo | |
123 | lengths (those are uncertain, usually invalidated during | |
124 | maybe_invalidate, except when the alias oracle knows better). | |
125 | Functions like strcat on the other side adjust the whole | |
126 | related strinfo chain. | |
127 | They are updated lazily, so to use the chain the same first fields | |
128 | and si->prev->next == si->idx needs to be verified. */ | |
129 | int first; | |
130 | int next; | |
131 | int prev; | |
132 | /* A flag whether the string is known to be written in the current | |
133 | function. */ | |
134 | bool writable; | |
135 | /* A flag for the next maybe_invalidate that this strinfo shouldn't | |
136 | be invalidated. Always cleared by maybe_invalidate. */ | |
137 | bool dont_invalidate; | |
e3f9a279 RS |
138 | /* True if the string is known to be nul-terminated after NONZERO_CHARS |
139 | characters. False is useful when detecting strings that are built | |
140 | up via successive memcpys. */ | |
141 | bool full_string_p; | |
526ceb68 | 142 | }; |
8b57bfeb JJ |
143 | |
144 | /* Pool for allocating strinfo_struct entries. */ | |
526ceb68 | 145 | static object_allocator<strinfo> strinfo_pool ("strinfo pool"); |
8b57bfeb JJ |
146 | |
147 | /* Vector mapping positive string indexes to strinfo, for the | |
148 | current basic block. The first pointer in the vector is special, | |
149 | it is either NULL, meaning the vector isn't shared, or it is | |
150 | a basic block pointer to the owner basic_block if shared. | |
151 | If some other bb wants to modify the vector, the vector needs | |
152 | to be unshared first, and only the owner bb is supposed to free it. */ | |
526ceb68 | 153 | static vec<strinfo *, va_heap, vl_embed> *stridx_to_strinfo; |
8b57bfeb JJ |
154 | |
155 | /* One OFFSET->IDX mapping. */ | |
156 | struct stridxlist | |
157 | { | |
158 | struct stridxlist *next; | |
159 | HOST_WIDE_INT offset; | |
160 | int idx; | |
161 | }; | |
162 | ||
163 | /* Hash table entry, mapping a DECL to a chain of OFFSET->IDX mappings. */ | |
164 | struct decl_stridxlist_map | |
165 | { | |
166 | struct tree_map_base base; | |
167 | struct stridxlist list; | |
168 | }; | |
169 | ||
170 | /* Hash table for mapping decls to a chained list of offset -> idx | |
171 | mappings. */ | |
22fca489 MS |
172 | typedef hash_map<tree_decl_hash, stridxlist> decl_to_stridxlist_htab_t; |
173 | static decl_to_stridxlist_htab_t *decl_to_stridxlist_htab; | |
8b57bfeb | 174 | |
9bc83f27 JJ |
175 | /* Hash table mapping strlen (or strnlen with constant bound and return |
176 | smaller than bound) calls to stridx instances describing | |
6a33d0ff MS |
177 | the calls' arguments. Non-null only when warn_stringop_truncation |
178 | is non-zero. */ | |
025d57f0 | 179 | typedef std::pair<int, location_t> stridx_strlenloc; |
6a33d0ff | 180 | static hash_map<tree, stridx_strlenloc> *strlen_to_stridx; |
025d57f0 | 181 | |
8b57bfeb JJ |
182 | /* Obstack for struct stridxlist and struct decl_stridxlist_map. */ |
183 | static struct obstack stridx_obstack; | |
184 | ||
185 | /* Last memcpy statement if it could be adjusted if the trailing | |
186 | '\0' written is immediately overwritten, or | |
187 | *x = '\0' store that could be removed if it is immediately overwritten. */ | |
188 | struct laststmt_struct | |
189 | { | |
355fe088 | 190 | gimple *stmt; |
8b57bfeb JJ |
191 | tree len; |
192 | int stridx; | |
193 | } laststmt; | |
194 | ||
e3f9a279 | 195 | static int get_stridx_plus_constant (strinfo *, unsigned HOST_WIDE_INT, tree); |
ba6e17e7 MS |
196 | static bool get_range_strlen_dynamic (tree, gimple *s, c_strlen_data *, |
197 | bitmap, range_query *, unsigned *); | |
e3f9a279 | 198 | |
f7d86b5c | 199 | /* Sets MINMAX to either the constant value or the range VAL is in |
ef29b12c | 200 | and returns either the constant value or VAL on success or null |
c3895ef4 MS |
201 | when the range couldn't be determined. Uses RVALS or CFUN for |
202 | range info, whichever is nonnull. */ | |
f7d86b5c | 203 | |
ef29b12c | 204 | tree |
f5299992 AH |
205 | get_range (tree val, gimple *stmt, wide_int minmax[2], |
206 | range_query *rvals /* = NULL */) | |
f7d86b5c | 207 | { |
ece28da9 | 208 | if (!rvals) |
c3895ef4 MS |
209 | { |
210 | if (!cfun) | |
211 | /* When called from front ends for global initializers CFUN | |
212 | may be null. */ | |
213 | return NULL_TREE; | |
214 | ||
215 | rvals = get_range_query (cfun); | |
216 | } | |
f7d86b5c | 217 | |
45f4e2b0 | 218 | value_range vr; |
ece28da9 | 219 | if (!rvals->range_of_expr (vr, val, stmt)) |
45f4e2b0 AH |
220 | return NULL_TREE; |
221 | ||
45f4e2b0 | 222 | value_range_kind rng = vr.kind (); |
f7d86b5c | 223 | if (rng == VR_RANGE) |
83685efd | 224 | { |
ece28da9 MS |
225 | /* Only handle straight ranges. */ |
226 | minmax[0] = wi::to_wide (vr.min ()); | |
227 | minmax[1] = wi::to_wide (vr.max ()); | |
83685efd MS |
228 | return val; |
229 | } | |
230 | ||
ef29b12c | 231 | return NULL_TREE; |
f7d86b5c MS |
232 | } |
233 | ||
47e4ab65 AH |
234 | class strlen_pass : public dom_walker |
235 | { | |
236 | public: | |
237 | strlen_pass (cdi_direction direction) | |
238 | : dom_walker (direction), | |
6b8b9596 | 239 | ptr_qry (&m_ranger, &var_cache), |
47e4ab65 AH |
240 | var_cache (), |
241 | m_cleanup_cfg (false) | |
242 | { | |
243 | } | |
244 | ||
245 | ~strlen_pass (); | |
246 | ||
247 | virtual edge before_dom_children (basic_block); | |
248 | virtual void after_dom_children (basic_block); | |
249 | ||
250 | bool check_and_optimize_stmt (bool *cleanup_eh); | |
251 | bool check_and_optimize_call (bool *zero_write); | |
252 | bool handle_assign (tree lhs, bool *zero_write); | |
253 | bool handle_store (bool *zero_write); | |
254 | void handle_pointer_plus (); | |
255 | void handle_builtin_strlen (); | |
256 | void handle_builtin_strchr (); | |
257 | void handle_builtin_strcpy (built_in_function); | |
258 | void handle_integral_assign (bool *cleanup_eh); | |
259 | void handle_builtin_stxncpy_strncat (bool append_p); | |
260 | void handle_builtin_memcpy (built_in_function bcode); | |
261 | void handle_builtin_strcat (built_in_function bcode); | |
262 | void handle_builtin_strncat (built_in_function); | |
263 | bool handle_builtin_memset (bool *zero_write); | |
264 | bool handle_builtin_memcmp (); | |
265 | bool handle_builtin_string_cmp (); | |
266 | void handle_alloc_call (built_in_function); | |
267 | void maybe_warn_overflow (gimple *stmt, bool call_lhs, tree len, | |
268 | strinfo *si = NULL, bool plus_one = false, | |
269 | bool rawmem = false); | |
270 | void maybe_warn_overflow (gimple *stmt, bool call_lhs, | |
271 | unsigned HOST_WIDE_INT len, | |
272 | strinfo *si = NULL, | |
273 | bool plus_one = false, bool rawmem = false); | |
274 | void adjust_last_stmt (strinfo *si, gimple *stmt, bool is_strcat); | |
275 | tree strxcmp_eqz_result (gimple *stmt, tree arg1, int idx1, | |
276 | tree arg2, int idx2, | |
277 | unsigned HOST_WIDE_INT bound, | |
278 | unsigned HOST_WIDE_INT len[2], | |
279 | unsigned HOST_WIDE_INT *psize); | |
280 | bool count_nonzero_bytes (tree expr_or_type, | |
6b8b9596 | 281 | gimple *stmt, |
47e4ab65 AH |
282 | unsigned lenrange[3], bool *nulterm, |
283 | bool *allnul, bool *allnonnul); | |
284 | bool count_nonzero_bytes (tree exp, | |
6b8b9596 | 285 | gimple *stmt, |
47e4ab65 AH |
286 | unsigned HOST_WIDE_INT offset, |
287 | unsigned HOST_WIDE_INT nbytes, | |
288 | unsigned lenrange[3], bool *nulterm, | |
289 | bool *allnul, bool *allnonnul, | |
290 | ssa_name_limit_t &snlim); | |
291 | bool count_nonzero_bytes_addr (tree exp, | |
6b8b9596 | 292 | gimple *stmt, |
47e4ab65 AH |
293 | unsigned HOST_WIDE_INT offset, |
294 | unsigned HOST_WIDE_INT nbytes, | |
295 | unsigned lenrange[3], bool *nulterm, | |
296 | bool *allnul, bool *allnonnul, | |
297 | ssa_name_limit_t &snlim); | |
298 | bool get_len_or_size (gimple *stmt, tree arg, int idx, | |
299 | unsigned HOST_WIDE_INT lenrng[2], | |
300 | unsigned HOST_WIDE_INT *size, bool *nulterm); | |
301 | ||
6b8b9596 | 302 | gimple_ranger m_ranger; |
47e4ab65 AH |
303 | |
304 | /* A pointer_query object and its cache to store information about | |
305 | pointers and their targets in. */ | |
306 | pointer_query ptr_qry; | |
307 | pointer_query::cache_type var_cache; | |
308 | ||
309 | gimple_stmt_iterator m_gsi; | |
310 | ||
311 | /* Flag that will trigger TODO_cleanup_cfg to be returned in strlen | |
312 | execute function. */ | |
313 | bool m_cleanup_cfg; | |
314 | }; | |
315 | ||
e3f9a279 RS |
316 | /* Return: |
317 | ||
27c14dbc | 318 | * +1 if SI is known to start with more than OFF nonzero characters. |
e3f9a279 | 319 | |
02c4de76 | 320 | * 0 if SI is known to start with exactly OFF nonzero characters. |
e3f9a279 | 321 | |
02c4de76 MS |
322 | * -1 if SI either does not start with OFF nonzero characters |
323 | or the relationship between the number of leading nonzero | |
324 | characters in SI and OFF is unknown. */ | |
e3f9a279 | 325 | |
47e4ab65 | 326 | static int |
e3f9a279 RS |
327 | compare_nonzero_chars (strinfo *si, unsigned HOST_WIDE_INT off) |
328 | { | |
329 | if (si->nonzero_chars | |
330 | && TREE_CODE (si->nonzero_chars) == INTEGER_CST) | |
331 | return compare_tree_int (si->nonzero_chars, off); | |
332 | else | |
333 | return -1; | |
334 | } | |
335 | ||
27c14dbc MS |
336 | /* Same as above but suitable also for strings with non-constant lengths. |
337 | Uses RVALS to determine length range. */ | |
338 | ||
339 | static int | |
6b8b9596 AH |
340 | compare_nonzero_chars (strinfo *si, gimple *stmt, |
341 | unsigned HOST_WIDE_INT off, | |
f5299992 | 342 | range_query *rvals) |
27c14dbc MS |
343 | { |
344 | if (!si->nonzero_chars) | |
345 | return -1; | |
346 | ||
347 | if (TREE_CODE (si->nonzero_chars) == INTEGER_CST) | |
348 | return compare_tree_int (si->nonzero_chars, off); | |
349 | ||
02c4de76 | 350 | if (!rvals || TREE_CODE (si->nonzero_chars) != SSA_NAME) |
27c14dbc MS |
351 | return -1; |
352 | ||
f5299992 | 353 | value_range vr; |
6b8b9596 | 354 | if (!rvals->range_of_expr (vr, si->nonzero_chars, stmt)) |
f5299992 AH |
355 | return -1; |
356 | value_range_kind rng = vr.kind (); | |
357 | if (rng != VR_RANGE) | |
27c14dbc MS |
358 | return -1; |
359 | ||
02c4de76 MS |
360 | /* If the offset is less than the minimum length or if the bounds |
361 | of the length range are equal return the result of the comparison | |
362 | same as in the constant case. Otherwise return a conservative | |
363 | result. */ | |
f5299992 AH |
364 | int cmpmin = compare_tree_int (vr.min (), off); |
365 | if (cmpmin > 0 || tree_int_cst_equal (vr.min (), vr.max ())) | |
02c4de76 MS |
366 | return cmpmin; |
367 | ||
368 | return -1; | |
27c14dbc MS |
369 | } |
370 | ||
e3f9a279 RS |
371 | /* Return true if SI is known to be a zero-length string. */ |
372 | ||
373 | static inline bool | |
374 | zero_length_string_p (strinfo *si) | |
375 | { | |
376 | return si->full_string_p && integer_zerop (si->nonzero_chars); | |
377 | } | |
204a913b JJ |
378 | |
379 | /* Return strinfo vector entry IDX. */ | |
380 | ||
526ceb68 | 381 | static inline strinfo * |
204a913b JJ |
382 | get_strinfo (int idx) |
383 | { | |
384 | if (vec_safe_length (stridx_to_strinfo) <= (unsigned int) idx) | |
385 | return NULL; | |
386 | return (*stridx_to_strinfo)[idx]; | |
387 | } | |
388 | ||
bde63fde RS |
389 | /* Get the next strinfo in the chain after SI, or null if none. */ |
390 | ||
391 | static inline strinfo * | |
392 | get_next_strinfo (strinfo *si) | |
393 | { | |
394 | if (si->next == 0) | |
395 | return NULL; | |
396 | strinfo *nextsi = get_strinfo (si->next); | |
397 | if (nextsi == NULL || nextsi->first != si->first || nextsi->prev != si->idx) | |
398 | return NULL; | |
399 | return nextsi; | |
400 | } | |
401 | ||
e3f9a279 RS |
402 | /* Helper function for get_stridx. Return the strinfo index of the address |
403 | of EXP, which is available in PTR if nonnull. If OFFSET_OUT, it is | |
404 | OK to return the index for some X <= &EXP and store &EXP - X in | |
e7868dc6 MS |
405 | *OFFSET_OUT. When RVALS is nonnull uses it to determine range |
406 | information. */ | |
8b57bfeb JJ |
407 | |
408 | static int | |
6b8b9596 AH |
409 | get_addr_stridx (tree exp, gimple *stmt, |
410 | tree ptr, unsigned HOST_WIDE_INT *offset_out, | |
f5299992 | 411 | range_query *rvals = NULL) |
8b57bfeb JJ |
412 | { |
413 | HOST_WIDE_INT off; | |
5f3cd7c3 | 414 | struct stridxlist *list, *last = NULL; |
8b57bfeb JJ |
415 | tree base; |
416 | ||
c203e8a7 | 417 | if (!decl_to_stridxlist_htab) |
8b57bfeb JJ |
418 | return 0; |
419 | ||
a90c8804 RS |
420 | poly_int64 poff; |
421 | base = get_addr_base_and_unit_offset (exp, &poff); | |
422 | if (base == NULL || !DECL_P (base) || !poff.is_constant (&off)) | |
8b57bfeb JJ |
423 | return 0; |
424 | ||
1eb68d2d TS |
425 | list = decl_to_stridxlist_htab->get (base); |
426 | if (list == NULL) | |
8b57bfeb JJ |
427 | return 0; |
428 | ||
8b57bfeb JJ |
429 | do |
430 | { | |
431 | if (list->offset == off) | |
e3f9a279 RS |
432 | { |
433 | if (offset_out) | |
434 | *offset_out = 0; | |
435 | return list->idx; | |
436 | } | |
5f3cd7c3 JJ |
437 | if (list->offset > off) |
438 | return 0; | |
439 | last = list; | |
8b57bfeb JJ |
440 | list = list->next; |
441 | } | |
442 | while (list); | |
5f3cd7c3 | 443 | |
e3f9a279 | 444 | if ((offset_out || ptr) && last && last->idx > 0) |
5f3cd7c3 | 445 | { |
e3f9a279 RS |
446 | unsigned HOST_WIDE_INT rel_off |
447 | = (unsigned HOST_WIDE_INT) off - last->offset; | |
5f3cd7c3 | 448 | strinfo *si = get_strinfo (last->idx); |
6b8b9596 | 449 | if (si && compare_nonzero_chars (si, stmt, rel_off, rvals) >= 0) |
e3f9a279 RS |
450 | { |
451 | if (offset_out) | |
452 | { | |
453 | *offset_out = rel_off; | |
454 | return last->idx; | |
455 | } | |
456 | else | |
457 | return get_stridx_plus_constant (si, rel_off, ptr); | |
458 | } | |
5f3cd7c3 | 459 | } |
8b57bfeb JJ |
460 | return 0; |
461 | } | |
462 | ||
f7d86b5c MS |
463 | /* Returns string index for EXP. When EXP is an SSA_NAME that refers |
464 | to a known strinfo with an offset and OFFRNG is non-null, sets | |
465 | both elements of the OFFRNG array to the range of the offset and | |
466 | returns the index of the known strinfo. In this case the result | |
ef29b12c MS |
467 | must not be used in for functions that modify the string. |
468 | When nonnull, uses RVALS to determine range information. */ | |
8b57bfeb JJ |
469 | |
470 | static int | |
6b8b9596 AH |
471 | get_stridx (tree exp, gimple *stmt, |
472 | wide_int offrng[2] = NULL, range_query *rvals = NULL) | |
8b57bfeb | 473 | { |
f7d86b5c | 474 | if (offrng) |
ef29b12c | 475 | offrng[0] = offrng[1] = wi::zero (TYPE_PRECISION (ptrdiff_type_node)); |
f7d86b5c | 476 | |
8b57bfeb | 477 | if (TREE_CODE (exp) == SSA_NAME) |
204a913b JJ |
478 | { |
479 | if (ssa_ver_to_stridx[SSA_NAME_VERSION (exp)]) | |
480 | return ssa_ver_to_stridx[SSA_NAME_VERSION (exp)]; | |
7802a8ec | 481 | |
204a913b | 482 | tree e = exp; |
f7d86b5c | 483 | int last_idx = 0; |
7802a8ec MS |
484 | HOST_WIDE_INT offset = 0; |
485 | /* Follow a chain of at most 5 assignments. */ | |
486 | for (int i = 0; i < 5; i++) | |
204a913b | 487 | { |
355fe088 | 488 | gimple *def_stmt = SSA_NAME_DEF_STMT (e); |
7802a8ec | 489 | if (!is_gimple_assign (def_stmt)) |
f7d86b5c | 490 | return last_idx; |
7802a8ec MS |
491 | |
492 | tree_code rhs_code = gimple_assign_rhs_code (def_stmt); | |
493 | tree ptr, off; | |
494 | ||
495 | if (rhs_code == ADDR_EXPR) | |
496 | { | |
497 | /* Handle indices/offsets into VLAs which are implemented | |
498 | as pointers to arrays. */ | |
499 | ptr = gimple_assign_rhs1 (def_stmt); | |
500 | ptr = TREE_OPERAND (ptr, 0); | |
501 | ||
502 | /* Handle also VLAs of types larger than char. */ | |
503 | if (tree eltsize = TYPE_SIZE_UNIT (TREE_TYPE (ptr))) | |
504 | { | |
505 | if (TREE_CODE (ptr) == ARRAY_REF) | |
506 | { | |
507 | off = TREE_OPERAND (ptr, 1); | |
7802a8ec | 508 | ptr = TREE_OPERAND (ptr, 0); |
bc09939d MS |
509 | if (!integer_onep (eltsize)) |
510 | { | |
511 | /* Scale the array index by the size of the element | |
512 | type in the rare case that it's greater than | |
513 | the typical 1 for char, making sure both operands | |
514 | have the same type. */ | |
515 | eltsize = fold_convert (ssizetype, eltsize); | |
516 | off = fold_convert (ssizetype, off); | |
517 | off = fold_build2 (MULT_EXPR, ssizetype, off, eltsize); | |
518 | } | |
7802a8ec MS |
519 | } |
520 | else | |
521 | off = integer_zero_node; | |
522 | } | |
523 | else | |
524 | return 0; | |
525 | ||
526 | if (TREE_CODE (ptr) != MEM_REF) | |
527 | return 0; | |
528 | ||
529 | /* Add the MEM_REF byte offset. */ | |
530 | tree mem_off = TREE_OPERAND (ptr, 1); | |
531 | off = fold_build2 (PLUS_EXPR, TREE_TYPE (off), off, mem_off); | |
532 | ptr = TREE_OPERAND (ptr, 0); | |
533 | } | |
534 | else if (rhs_code == POINTER_PLUS_EXPR) | |
535 | { | |
536 | ptr = gimple_assign_rhs1 (def_stmt); | |
537 | off = gimple_assign_rhs2 (def_stmt); | |
538 | } | |
539 | else | |
204a913b | 540 | return 0; |
7802a8ec | 541 | |
f7d86b5c | 542 | if (TREE_CODE (ptr) != SSA_NAME) |
204a913b | 543 | return 0; |
f7d86b5c MS |
544 | |
545 | if (!tree_fits_shwi_p (off)) | |
546 | { | |
547 | if (int idx = ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)]) | |
548 | if (offrng) | |
549 | { | |
550 | /* Only when requested by setting OFFRNG to non-null, | |
551 | return the index corresponding to the SSA_NAME. | |
552 | Do this irrespective of the whether the offset | |
553 | is known. */ | |
f5299992 | 554 | if (get_range (off, def_stmt, offrng, rvals)) |
f7d86b5c MS |
555 | { |
556 | /* When the offset range is known, increment it | |
557 | it by the constant offset computed in prior | |
558 | iterations and store it in the OFFRNG array. */ | |
559 | offrng[0] += offset; | |
560 | offrng[1] += offset; | |
561 | } | |
562 | else | |
563 | { | |
564 | /* When the offset range cannot be determined | |
565 | store [0, SIZE_MAX] and let the caller decide | |
566 | if the offset matters. */ | |
567 | offrng[1] = wi::to_wide (TYPE_MAX_VALUE (sizetype)); | |
568 | offrng[0] = wi::zero (offrng[1].get_precision ()); | |
569 | } | |
570 | return idx; | |
571 | } | |
572 | return 0; | |
573 | } | |
574 | ||
7802a8ec | 575 | HOST_WIDE_INT this_off = tree_to_shwi (off); |
f7d86b5c MS |
576 | if (offrng) |
577 | { | |
578 | offrng[0] += wi::shwi (this_off, offrng->get_precision ()); | |
579 | offrng[1] += offrng[0]; | |
580 | } | |
581 | ||
204a913b | 582 | if (this_off < 0) |
f7d86b5c MS |
583 | return last_idx; |
584 | ||
7802a8ec MS |
585 | offset = (unsigned HOST_WIDE_INT) offset + this_off; |
586 | if (offset < 0) | |
f7d86b5c MS |
587 | return last_idx; |
588 | ||
589 | if (int idx = ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)]) | |
204a913b | 590 | { |
f7d86b5c MS |
591 | strinfo *si = get_strinfo (idx); |
592 | if (si) | |
593 | { | |
594 | if (compare_nonzero_chars (si, offset) >= 0) | |
595 | return get_stridx_plus_constant (si, offset, exp); | |
596 | ||
597 | if (offrng) | |
598 | last_idx = idx; | |
599 | } | |
204a913b | 600 | } |
7802a8ec | 601 | e = ptr; |
204a913b | 602 | } |
f7d86b5c MS |
603 | |
604 | return last_idx; | |
204a913b | 605 | } |
8b57bfeb JJ |
606 | |
607 | if (TREE_CODE (exp) == ADDR_EXPR) | |
608 | { | |
6b8b9596 | 609 | int idx = get_addr_stridx (TREE_OPERAND (exp, 0), stmt, exp, NULL); |
8b57bfeb JJ |
610 | if (idx != 0) |
611 | return idx; | |
612 | } | |
613 | ||
6ab24ea8 MS |
614 | const char *p = c_getstr (exp); |
615 | if (p) | |
616 | return ~(int) strlen (p); | |
b3c3685a | 617 | |
8b57bfeb JJ |
618 | return 0; |
619 | } | |
620 | ||
621 | /* Return true if strinfo vector is shared with the immediate dominator. */ | |
622 | ||
623 | static inline bool | |
624 | strinfo_shared (void) | |
625 | { | |
9771b263 DN |
626 | return vec_safe_length (stridx_to_strinfo) |
627 | && (*stridx_to_strinfo)[0] != NULL; | |
8b57bfeb JJ |
628 | } |
629 | ||
630 | /* Unshare strinfo vector that is shared with the immediate dominator. */ | |
631 | ||
632 | static void | |
633 | unshare_strinfo_vec (void) | |
634 | { | |
526ceb68 | 635 | strinfo *si; |
8b57bfeb JJ |
636 | unsigned int i = 0; |
637 | ||
638 | gcc_assert (strinfo_shared ()); | |
9771b263 DN |
639 | stridx_to_strinfo = vec_safe_copy (stridx_to_strinfo); |
640 | for (i = 1; vec_safe_iterate (stridx_to_strinfo, i, &si); ++i) | |
8b57bfeb JJ |
641 | if (si != NULL) |
642 | si->refcount++; | |
9771b263 | 643 | (*stridx_to_strinfo)[0] = NULL; |
8b57bfeb JJ |
644 | } |
645 | ||
646 | /* Attempt to create a string index for exp, ADDR_EXPR's operand. | |
647 | Return a pointer to the location where the string index can | |
648 | be stored (if 0) or is stored, or NULL if this can't be tracked. */ | |
649 | ||
650 | static int * | |
651 | addr_stridxptr (tree exp) | |
652 | { | |
8b57bfeb JJ |
653 | HOST_WIDE_INT off; |
654 | ||
a90c8804 RS |
655 | poly_int64 poff; |
656 | tree base = get_addr_base_and_unit_offset (exp, &poff); | |
657 | if (base == NULL_TREE || !DECL_P (base) || !poff.is_constant (&off)) | |
8b57bfeb JJ |
658 | return NULL; |
659 | ||
c203e8a7 | 660 | if (!decl_to_stridxlist_htab) |
8b57bfeb | 661 | { |
1eb68d2d | 662 | decl_to_stridxlist_htab |
fb5c464a | 663 | = new hash_map<tree_decl_hash, stridxlist> (64); |
8b57bfeb JJ |
664 | gcc_obstack_init (&stridx_obstack); |
665 | } | |
1eb68d2d TS |
666 | |
667 | bool existed; | |
668 | stridxlist *list = &decl_to_stridxlist_htab->get_or_insert (base, &existed); | |
669 | if (existed) | |
8b57bfeb JJ |
670 | { |
671 | int i; | |
5f3cd7c3 JJ |
672 | stridxlist *before = NULL; |
673 | for (i = 0; i < 32; i++) | |
8b57bfeb JJ |
674 | { |
675 | if (list->offset == off) | |
676 | return &list->idx; | |
5f3cd7c3 JJ |
677 | if (list->offset > off && before == NULL) |
678 | before = list; | |
8b57bfeb JJ |
679 | if (list->next == NULL) |
680 | break; | |
5f3cd7c3 | 681 | list = list->next; |
8b57bfeb | 682 | } |
5f3cd7c3 | 683 | if (i == 32) |
8b57bfeb | 684 | return NULL; |
5f3cd7c3 JJ |
685 | if (before) |
686 | { | |
687 | list = before; | |
688 | before = XOBNEW (&stridx_obstack, struct stridxlist); | |
689 | *before = *list; | |
690 | list->next = before; | |
691 | list->offset = off; | |
692 | list->idx = 0; | |
693 | return &list->idx; | |
694 | } | |
8b57bfeb JJ |
695 | list->next = XOBNEW (&stridx_obstack, struct stridxlist); |
696 | list = list->next; | |
697 | } | |
1eb68d2d | 698 | |
8b57bfeb JJ |
699 | list->next = NULL; |
700 | list->offset = off; | |
701 | list->idx = 0; | |
702 | return &list->idx; | |
703 | } | |
704 | ||
705 | /* Create a new string index, or return 0 if reached limit. */ | |
706 | ||
707 | static int | |
708 | new_stridx (tree exp) | |
709 | { | |
710 | int idx; | |
028d4092 | 711 | if (max_stridx >= param_max_tracked_strlens) |
8b57bfeb JJ |
712 | return 0; |
713 | if (TREE_CODE (exp) == SSA_NAME) | |
714 | { | |
715 | if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (exp)) | |
716 | return 0; | |
717 | idx = max_stridx++; | |
9771b263 | 718 | ssa_ver_to_stridx[SSA_NAME_VERSION (exp)] = idx; |
8b57bfeb JJ |
719 | return idx; |
720 | } | |
721 | if (TREE_CODE (exp) == ADDR_EXPR) | |
722 | { | |
723 | int *pidx = addr_stridxptr (TREE_OPERAND (exp, 0)); | |
724 | if (pidx != NULL) | |
725 | { | |
726 | gcc_assert (*pidx == 0); | |
727 | *pidx = max_stridx++; | |
728 | return *pidx; | |
729 | } | |
730 | } | |
731 | return 0; | |
732 | } | |
733 | ||
734 | /* Like new_stridx, but for ADDR_EXPR's operand instead. */ | |
735 | ||
736 | static int | |
737 | new_addr_stridx (tree exp) | |
738 | { | |
739 | int *pidx; | |
028d4092 | 740 | if (max_stridx >= param_max_tracked_strlens) |
8b57bfeb JJ |
741 | return 0; |
742 | pidx = addr_stridxptr (exp); | |
743 | if (pidx != NULL) | |
744 | { | |
745 | gcc_assert (*pidx == 0); | |
746 | *pidx = max_stridx++; | |
747 | return *pidx; | |
748 | } | |
749 | return 0; | |
750 | } | |
751 | ||
752 | /* Create a new strinfo. */ | |
753 | ||
526ceb68 | 754 | static strinfo * |
e3f9a279 | 755 | new_strinfo (tree ptr, int idx, tree nonzero_chars, bool full_string_p) |
8b57bfeb | 756 | { |
526ceb68 | 757 | strinfo *si = strinfo_pool.allocate (); |
e3f9a279 | 758 | si->nonzero_chars = nonzero_chars; |
4e3d3e40 | 759 | STRIP_USELESS_TYPE_CONVERSION (ptr); |
8b57bfeb JJ |
760 | si->ptr = ptr; |
761 | si->stmt = NULL; | |
ef29b12c | 762 | si->alloc = NULL; |
8b57bfeb JJ |
763 | si->endptr = NULL_TREE; |
764 | si->refcount = 1; | |
765 | si->idx = idx; | |
766 | si->first = 0; | |
767 | si->prev = 0; | |
768 | si->next = 0; | |
769 | si->writable = false; | |
770 | si->dont_invalidate = false; | |
e3f9a279 | 771 | si->full_string_p = full_string_p; |
8b57bfeb JJ |
772 | return si; |
773 | } | |
774 | ||
775 | /* Decrease strinfo refcount and free it if not referenced anymore. */ | |
776 | ||
777 | static inline void | |
526ceb68 | 778 | free_strinfo (strinfo *si) |
8b57bfeb JJ |
779 | { |
780 | if (si && --si->refcount == 0) | |
33e7d32e | 781 | strinfo_pool.remove (si); |
8b57bfeb JJ |
782 | } |
783 | ||
8b57bfeb JJ |
784 | /* Set strinfo in the vector entry IDX to SI. */ |
785 | ||
786 | static inline void | |
526ceb68 | 787 | set_strinfo (int idx, strinfo *si) |
8b57bfeb | 788 | { |
9771b263 | 789 | if (vec_safe_length (stridx_to_strinfo) && (*stridx_to_strinfo)[0]) |
8b57bfeb | 790 | unshare_strinfo_vec (); |
9771b263 | 791 | if (vec_safe_length (stridx_to_strinfo) <= (unsigned int) idx) |
cb3874dc | 792 | vec_safe_grow_cleared (stridx_to_strinfo, idx + 1, true); |
9771b263 | 793 | (*stridx_to_strinfo)[idx] = si; |
8b57bfeb JJ |
794 | } |
795 | ||
862088aa RS |
796 | /* Return the first strinfo in the related strinfo chain |
797 | if all strinfos in between belong to the chain, otherwise NULL. */ | |
798 | ||
799 | static strinfo * | |
800 | verify_related_strinfos (strinfo *origsi) | |
801 | { | |
802 | strinfo *si = origsi, *psi; | |
803 | ||
804 | if (origsi->first == 0) | |
805 | return NULL; | |
806 | for (; si->prev; si = psi) | |
807 | { | |
808 | if (si->first != origsi->first) | |
809 | return NULL; | |
810 | psi = get_strinfo (si->prev); | |
811 | if (psi == NULL) | |
812 | return NULL; | |
813 | if (psi->next != si->idx) | |
814 | return NULL; | |
815 | } | |
816 | if (si->idx != si->first) | |
817 | return NULL; | |
818 | return si; | |
819 | } | |
820 | ||
821 | /* Set SI's endptr to ENDPTR and compute its length based on SI->ptr. | |
822 | Use LOC for folding. */ | |
823 | ||
824 | static void | |
825 | set_endptr_and_length (location_t loc, strinfo *si, tree endptr) | |
826 | { | |
827 | si->endptr = endptr; | |
828 | si->stmt = NULL; | |
829 | tree start_as_size = fold_convert_loc (loc, size_type_node, si->ptr); | |
830 | tree end_as_size = fold_convert_loc (loc, size_type_node, endptr); | |
e3f9a279 RS |
831 | si->nonzero_chars = fold_build2_loc (loc, MINUS_EXPR, size_type_node, |
832 | end_as_size, start_as_size); | |
833 | si->full_string_p = true; | |
862088aa RS |
834 | } |
835 | ||
22fca489 MS |
836 | /* Return the string length, or NULL if it can't be computed. |
837 | The length may but need not be constant. Instead, it might be | |
838 | the result of a strlen() call. */ | |
8b57bfeb JJ |
839 | |
840 | static tree | |
526ceb68 | 841 | get_string_length (strinfo *si) |
8b57bfeb | 842 | { |
22fca489 MS |
843 | /* If the length has already been computed return it if it's exact |
844 | (i.e., the string is nul-terminated at NONZERO_CHARS), or return | |
845 | null if it isn't. */ | |
e3f9a279 RS |
846 | if (si->nonzero_chars) |
847 | return si->full_string_p ? si->nonzero_chars : NULL; | |
8b57bfeb | 848 | |
22fca489 MS |
849 | /* If the string is the result of one of the built-in calls below |
850 | attempt to compute the length from the call statement. */ | |
8b57bfeb JJ |
851 | if (si->stmt) |
852 | { | |
355fe088 | 853 | gimple *stmt = si->stmt, *lenstmt; |
83d5977e | 854 | tree callee, lhs, fn, tem; |
8b57bfeb JJ |
855 | location_t loc; |
856 | gimple_stmt_iterator gsi; | |
857 | ||
858 | gcc_assert (is_gimple_call (stmt)); | |
859 | callee = gimple_call_fndecl (stmt); | |
3d78e008 | 860 | gcc_assert (callee && fndecl_built_in_p (callee, BUILT_IN_NORMAL)); |
8b57bfeb | 861 | lhs = gimple_call_lhs (stmt); |
8b57bfeb JJ |
862 | /* unshare_strinfo is intentionally not called here. The (delayed) |
863 | transformation of strcpy or strcat into stpcpy is done at the place | |
864 | of the former strcpy/strcat call and so can affect all the strinfos | |
865 | with the same stmt. If they were unshared before and transformation | |
866 | has been already done, the handling of BUILT_IN_STPCPY{,_CHK} should | |
867 | just compute the right length. */ | |
868 | switch (DECL_FUNCTION_CODE (callee)) | |
869 | { | |
870 | case BUILT_IN_STRCAT: | |
871 | case BUILT_IN_STRCAT_CHK: | |
872 | gsi = gsi_for_stmt (stmt); | |
e79983f4 | 873 | fn = builtin_decl_implicit (BUILT_IN_STRLEN); |
8b57bfeb | 874 | gcc_assert (lhs == NULL_TREE); |
8b57bfeb | 875 | tem = unshare_expr (gimple_call_arg (stmt, 0)); |
31db0fe0 | 876 | lenstmt = gimple_build_call (fn, 1, tem); |
83d5977e | 877 | lhs = make_ssa_name (TREE_TYPE (TREE_TYPE (fn)), lenstmt); |
8b57bfeb JJ |
878 | gimple_call_set_lhs (lenstmt, lhs); |
879 | gimple_set_vuse (lenstmt, gimple_vuse (stmt)); | |
880 | gsi_insert_before (&gsi, lenstmt, GSI_SAME_STMT); | |
8b57bfeb | 881 | tem = gimple_call_arg (stmt, 0); |
33960e2e TG |
882 | if (!ptrofftype_p (TREE_TYPE (lhs))) |
883 | { | |
884 | lhs = convert_to_ptrofftype (lhs); | |
885 | lhs = force_gimple_operand_gsi (&gsi, lhs, true, NULL_TREE, | |
886 | true, GSI_SAME_STMT); | |
887 | } | |
0d0e4a03 JJ |
888 | lenstmt = gimple_build_assign |
889 | (make_ssa_name (TREE_TYPE (gimple_call_arg (stmt, 0))), | |
890 | POINTER_PLUS_EXPR,tem, lhs); | |
8b57bfeb JJ |
891 | gsi_insert_before (&gsi, lenstmt, GSI_SAME_STMT); |
892 | gimple_call_set_arg (stmt, 0, gimple_assign_lhs (lenstmt)); | |
893 | lhs = NULL_TREE; | |
894 | /* FALLTHRU */ | |
895 | case BUILT_IN_STRCPY: | |
2dcab30b | 896 | case BUILT_IN_STRCPY_CHK: |
1e762c6a | 897 | gcc_assert (builtin_decl_implicit_p (BUILT_IN_STPCPY)); |
2dcab30b ML |
898 | if (gimple_call_num_args (stmt) == 2) |
899 | fn = builtin_decl_implicit (BUILT_IN_STPCPY); | |
900 | else | |
901 | fn = builtin_decl_explicit (BUILT_IN_STPCPY_CHK); | |
8b57bfeb JJ |
902 | gcc_assert (lhs == NULL_TREE); |
903 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
904 | { | |
905 | fprintf (dump_file, "Optimizing: "); | |
906 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
907 | } | |
908 | gimple_call_set_fndecl (stmt, fn); | |
83d5977e | 909 | lhs = make_ssa_name (TREE_TYPE (TREE_TYPE (fn)), stmt); |
8b57bfeb JJ |
910 | gimple_call_set_lhs (stmt, lhs); |
911 | update_stmt (stmt); | |
912 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
913 | { | |
914 | fprintf (dump_file, "into: "); | |
915 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
916 | } | |
917 | /* FALLTHRU */ | |
918 | case BUILT_IN_STPCPY: | |
919 | case BUILT_IN_STPCPY_CHK: | |
920 | gcc_assert (lhs != NULL_TREE); | |
921 | loc = gimple_location (stmt); | |
862088aa RS |
922 | set_endptr_and_length (loc, si, lhs); |
923 | for (strinfo *chainsi = verify_related_strinfos (si); | |
924 | chainsi != NULL; | |
925 | chainsi = get_next_strinfo (chainsi)) | |
e3f9a279 | 926 | if (chainsi->nonzero_chars == NULL) |
862088aa | 927 | set_endptr_and_length (loc, chainsi, lhs); |
8b57bfeb | 928 | break; |
ef29b12c MS |
929 | case BUILT_IN_ALLOCA: |
930 | case BUILT_IN_ALLOCA_WITH_ALIGN: | |
24314386 MG |
931 | case BUILT_IN_MALLOC: |
932 | break; | |
e3f9a279 | 933 | /* BUILT_IN_CALLOC always has si->nonzero_chars set. */ |
8b57bfeb JJ |
934 | default: |
935 | gcc_unreachable (); | |
936 | break; | |
937 | } | |
938 | } | |
939 | ||
e3f9a279 | 940 | return si->nonzero_chars; |
8b57bfeb JJ |
941 | } |
942 | ||
22fca489 | 943 | /* Dump strlen data to FP for statement STMT. When non-null, RVALS |
f5299992 AH |
944 | points to the valuation engine used to calculate ranges, and is |
945 | used to dump strlen range for non-constant results. */ | |
22fca489 MS |
946 | |
947 | DEBUG_FUNCTION void | |
f5299992 | 948 | dump_strlen_info (FILE *fp, gimple *stmt, range_query *rvals) |
22fca489 MS |
949 | { |
950 | if (stmt) | |
951 | { | |
952 | fprintf (fp, "\nDumping strlen pass data after "); | |
953 | print_gimple_expr (fp, stmt, TDF_LINENO); | |
954 | fputc ('\n', fp); | |
955 | } | |
956 | else | |
957 | fprintf (fp, "\nDumping strlen pass data\n"); | |
958 | ||
959 | fprintf (fp, "max_stridx = %i\n", max_stridx); | |
960 | fprintf (fp, "ssa_ver_to_stridx has %u elements\n", | |
961 | ssa_ver_to_stridx.length ()); | |
962 | fprintf (fp, "stridx_to_strinfo"); | |
963 | if (stridx_to_strinfo) | |
964 | { | |
965 | fprintf (fp, " has %u elements\n", stridx_to_strinfo->length ()); | |
966 | for (unsigned i = 0; i != stridx_to_strinfo->length (); ++i) | |
967 | { | |
968 | if (strinfo *si = (*stridx_to_strinfo)[i]) | |
969 | { | |
970 | if (!si->idx) | |
971 | continue; | |
972 | fprintf (fp, " idx = %i", si->idx); | |
973 | if (si->ptr) | |
974 | { | |
975 | fprintf (fp, ", ptr = "); | |
976 | print_generic_expr (fp, si->ptr); | |
977 | } | |
ef29b12c MS |
978 | |
979 | if (si->nonzero_chars) | |
22fca489 | 980 | { |
ef29b12c MS |
981 | fprintf (fp, ", nonzero_chars = "); |
982 | print_generic_expr (fp, si->nonzero_chars); | |
983 | if (TREE_CODE (si->nonzero_chars) == SSA_NAME) | |
22fca489 | 984 | { |
ef29b12c MS |
985 | value_range_kind rng = VR_UNDEFINED; |
986 | wide_int min, max; | |
987 | if (rvals) | |
22fca489 | 988 | { |
f5299992 AH |
989 | value_range vr; |
990 | rvals->range_of_expr (vr, si->nonzero_chars, | |
991 | si->stmt); | |
992 | rng = vr.kind (); | |
993 | if (range_int_cst_p (&vr)) | |
ef29b12c | 994 | { |
f5299992 AH |
995 | min = wi::to_wide (vr.min ()); |
996 | max = wi::to_wide (vr.max ()); | |
ef29b12c MS |
997 | } |
998 | else | |
999 | rng = VR_UNDEFINED; | |
22fca489 MS |
1000 | } |
1001 | else | |
45f4e2b0 AH |
1002 | { |
1003 | value_range vr; | |
ece28da9 MS |
1004 | get_range_query (cfun) |
1005 | ->range_of_expr (vr, si->nonzero_chars); | |
45f4e2b0 AH |
1006 | rng = vr.kind (); |
1007 | if (!vr.undefined_p ()) | |
1008 | { | |
1009 | min = wi::to_wide (vr.min ()); | |
1010 | max = wi::to_wide (vr.max ()); | |
1011 | } | |
1012 | } | |
22fca489 | 1013 | |
ef29b12c MS |
1014 | if (rng == VR_RANGE || rng == VR_ANTI_RANGE) |
1015 | { | |
1016 | fprintf (fp, " %s[%llu, %llu]", | |
1017 | rng == VR_RANGE ? "" : "~", | |
1018 | (long long) min.to_uhwi (), | |
1019 | (long long) max.to_uhwi ()); | |
1020 | } | |
22fca489 MS |
1021 | } |
1022 | } | |
ef29b12c MS |
1023 | |
1024 | fprintf (fp, ", refcount = %i", si->refcount); | |
22fca489 MS |
1025 | if (si->stmt) |
1026 | { | |
1027 | fprintf (fp, ", stmt = "); | |
1028 | print_gimple_expr (fp, si->stmt, 0); | |
1029 | } | |
ef29b12c MS |
1030 | if (si->alloc) |
1031 | { | |
1032 | fprintf (fp, ", alloc = "); | |
1033 | print_gimple_expr (fp, si->alloc, 0); | |
1034 | } | |
22fca489 MS |
1035 | if (si->writable) |
1036 | fprintf (fp, ", writable"); | |
ef29b12c MS |
1037 | if (si->dont_invalidate) |
1038 | fprintf (fp, ", dont_invalidate"); | |
22fca489 MS |
1039 | if (si->full_string_p) |
1040 | fprintf (fp, ", full_string_p"); | |
1041 | if (strinfo *next = get_next_strinfo (si)) | |
1042 | { | |
1043 | fprintf (fp, ", {"); | |
1044 | do | |
1045 | fprintf (fp, "%i%s", next->idx, next->first ? ", " : ""); | |
1046 | while ((next = get_next_strinfo (next))); | |
1047 | fprintf (fp, "}"); | |
1048 | } | |
1049 | fputs ("\n", fp); | |
1050 | } | |
1051 | } | |
1052 | } | |
1053 | else | |
1054 | fprintf (fp, " = null\n"); | |
1055 | ||
1056 | fprintf (fp, "decl_to_stridxlist_htab"); | |
1057 | if (decl_to_stridxlist_htab) | |
1058 | { | |
1059 | fputs ("\n", fp); | |
1060 | typedef decl_to_stridxlist_htab_t::iterator iter_t; | |
1061 | for (iter_t it = decl_to_stridxlist_htab->begin (); | |
1062 | it != decl_to_stridxlist_htab->end (); ++it) | |
1063 | { | |
1064 | tree decl = (*it).first; | |
1065 | stridxlist *list = &(*it).second; | |
1066 | fprintf (fp, " decl = "); | |
1067 | print_generic_expr (fp, decl); | |
1068 | if (list) | |
1069 | { | |
1070 | fprintf (fp, ", offsets = {"); | |
1071 | for (; list; list = list->next) | |
1072 | fprintf (fp, "%lli%s", (long long) list->offset, | |
1073 | list->next ? ", " : ""); | |
1074 | fputs ("}", fp); | |
1075 | } | |
1076 | fputs ("\n", fp); | |
1077 | } | |
1078 | } | |
1079 | else | |
1080 | fprintf (fp, " = null\n"); | |
1081 | ||
1082 | if (laststmt.stmt) | |
1083 | { | |
1084 | fprintf (fp, "laststmt = "); | |
1085 | print_gimple_expr (fp, laststmt.stmt, 0); | |
1086 | fprintf (fp, ", len = "); | |
1087 | print_generic_expr (fp, laststmt.len); | |
1088 | fprintf (fp, ", stridx = %i\n", laststmt.stridx); | |
1089 | } | |
1090 | } | |
1091 | ||
ba6e17e7 MS |
1092 | /* Helper of get_range_strlen_dynamic(). See below. */ |
1093 | ||
1094 | static bool | |
1095 | get_range_strlen_phi (tree src, gphi *phi, | |
1096 | c_strlen_data *pdata, bitmap visited, | |
1097 | range_query *rvals, unsigned *pssa_def_max) | |
1098 | { | |
1099 | if (!bitmap_set_bit (visited, SSA_NAME_VERSION (src))) | |
1100 | return true; | |
1101 | ||
1102 | if (*pssa_def_max == 0) | |
1103 | return false; | |
1104 | ||
1105 | --*pssa_def_max; | |
1106 | ||
1107 | /* Iterate over the PHI arguments and determine the minimum and maximum | |
1108 | length/size of each and incorporate them into the overall result. */ | |
1109 | for (unsigned i = 0; i != gimple_phi_num_args (phi); ++i) | |
1110 | { | |
1111 | tree arg = gimple_phi_arg_def (phi, i); | |
1112 | if (arg == gimple_phi_result (phi)) | |
1113 | continue; | |
1114 | ||
1115 | c_strlen_data argdata = { }; | |
1116 | if (!get_range_strlen_dynamic (arg, phi, &argdata, visited, rvals, | |
1117 | pssa_def_max)) | |
1118 | { | |
1119 | pdata->maxlen = build_all_ones_cst (size_type_node); | |
1120 | continue; | |
1121 | } | |
1122 | ||
1123 | /* Set the DECL of an unterminated array this argument refers to | |
1124 | if one hasn't been found yet. */ | |
1125 | if (!pdata->decl && argdata.decl) | |
1126 | pdata->decl = argdata.decl; | |
1127 | ||
1128 | if (!argdata.minlen | |
1129 | || (integer_zerop (argdata.minlen) | |
1130 | && (!argdata.maxbound | |
1131 | || integer_all_onesp (argdata.maxbound)) | |
1132 | && integer_all_onesp (argdata.maxlen))) | |
1133 | { | |
1134 | /* Set the upper bound of the length to unbounded. */ | |
1135 | pdata->maxlen = build_all_ones_cst (size_type_node); | |
1136 | continue; | |
1137 | } | |
1138 | ||
1139 | /* Adjust the minimum and maximum length determined so far and | |
1140 | the upper bound on the array size. */ | |
1141 | if (!pdata->minlen | |
1142 | || tree_int_cst_lt (argdata.minlen, pdata->minlen)) | |
1143 | pdata->minlen = argdata.minlen; | |
1144 | ||
1145 | if (!pdata->maxlen | |
1146 | || (argdata.maxlen | |
1147 | && TREE_CODE (argdata.maxlen) == INTEGER_CST | |
1148 | && tree_int_cst_lt (pdata->maxlen, argdata.maxlen))) | |
1149 | pdata->maxlen = argdata.maxlen; | |
1150 | ||
1151 | if (!pdata->maxbound | |
1152 | || TREE_CODE (pdata->maxbound) != INTEGER_CST | |
1153 | || (argdata.maxbound | |
1154 | && tree_int_cst_lt (pdata->maxbound, argdata.maxbound) | |
1155 | && !integer_all_onesp (argdata.maxbound))) | |
1156 | pdata->maxbound = argdata.maxbound; | |
1157 | } | |
1158 | ||
1159 | return true; | |
1160 | } | |
1161 | ||
22fca489 MS |
1162 | /* Attempt to determine the length of the string SRC. On success, store |
1163 | the length in *PDATA and return true. Otherwise, return false. | |
f5299992 AH |
1164 | VISITED is a bitmap of visited PHI nodes. RVALS points to the valuation |
1165 | engine used to calculate ranges. PSSA_DEF_MAX to an SSA_NAME | |
1166 | assignment limit used to prevent runaway recursion. */ | |
22fca489 MS |
1167 | |
1168 | static bool | |
f5299992 | 1169 | get_range_strlen_dynamic (tree src, gimple *stmt, |
ba6e17e7 | 1170 | c_strlen_data *pdata, bitmap visited, |
f5299992 | 1171 | range_query *rvals, unsigned *pssa_def_max) |
22fca489 | 1172 | { |
6b8b9596 | 1173 | int idx = get_stridx (src, stmt); |
22fca489 MS |
1174 | if (!idx) |
1175 | { | |
1176 | if (TREE_CODE (src) == SSA_NAME) | |
1177 | { | |
1178 | gimple *def_stmt = SSA_NAME_DEF_STMT (src); | |
ba6e17e7 MS |
1179 | if (gphi *phi = dyn_cast<gphi *>(def_stmt)) |
1180 | return get_range_strlen_phi (src, phi, pdata, visited, rvals, | |
1181 | pssa_def_max); | |
22fca489 MS |
1182 | } |
1183 | ||
1184 | /* Return success regardless of the result and handle *PDATA | |
1185 | in the caller. */ | |
1186 | get_range_strlen (src, pdata, 1); | |
1187 | return true; | |
1188 | } | |
1189 | ||
1190 | if (idx < 0) | |
1191 | { | |
1192 | /* SRC is a string of constant length. */ | |
1193 | pdata->minlen = build_int_cst (size_type_node, ~idx); | |
1194 | pdata->maxlen = pdata->minlen; | |
1195 | pdata->maxbound = pdata->maxlen; | |
1196 | return true; | |
1197 | } | |
1198 | ||
1199 | if (strinfo *si = get_strinfo (idx)) | |
1200 | { | |
1201 | pdata->minlen = get_string_length (si); | |
93163192 | 1202 | if (!pdata->minlen && si->nonzero_chars) |
22fca489 MS |
1203 | { |
1204 | if (TREE_CODE (si->nonzero_chars) == INTEGER_CST) | |
1205 | pdata->minlen = si->nonzero_chars; | |
1206 | else if (TREE_CODE (si->nonzero_chars) == SSA_NAME) | |
1207 | { | |
f5299992 AH |
1208 | value_range vr; |
1209 | rvals->range_of_expr (vr, si->nonzero_chars, si->stmt); | |
1210 | if (range_int_cst_p (&vr)) | |
22fca489 | 1211 | { |
f5299992 AH |
1212 | pdata->minlen = vr.min (); |
1213 | pdata->maxlen = vr.max (); | |
22fca489 MS |
1214 | } |
1215 | else | |
1216 | pdata->minlen = build_zero_cst (size_type_node); | |
1217 | } | |
1218 | else | |
1219 | pdata->minlen = build_zero_cst (size_type_node); | |
1220 | ||
1221 | tree base = si->ptr; | |
1222 | if (TREE_CODE (base) == ADDR_EXPR) | |
1223 | base = TREE_OPERAND (base, 0); | |
1224 | ||
1225 | HOST_WIDE_INT off; | |
1226 | poly_int64 poff; | |
1227 | base = get_addr_base_and_unit_offset (base, &poff); | |
1228 | if (base | |
1229 | && DECL_P (base) | |
1230 | && TREE_CODE (TREE_TYPE (base)) == ARRAY_TYPE | |
1231 | && TYPE_SIZE_UNIT (TREE_TYPE (base)) | |
1232 | && poff.is_constant (&off)) | |
1233 | { | |
1234 | tree basetype = TREE_TYPE (base); | |
1235 | tree size = TYPE_SIZE_UNIT (basetype); | |
05c13c43 MS |
1236 | if (TREE_CODE (size) == INTEGER_CST) |
1237 | { | |
1238 | ++off; /* Increment for the terminating nul. */ | |
1239 | tree toffset = build_int_cst (size_type_node, off); | |
1240 | pdata->maxlen = fold_build2 (MINUS_EXPR, size_type_node, size, | |
1241 | toffset); | |
1242 | pdata->maxbound = pdata->maxlen; | |
1243 | } | |
1244 | else | |
1245 | pdata->maxlen = build_all_ones_cst (size_type_node); | |
22fca489 MS |
1246 | } |
1247 | else | |
1248 | pdata->maxlen = build_all_ones_cst (size_type_node); | |
1249 | } | |
93163192 | 1250 | else if (pdata->minlen && TREE_CODE (pdata->minlen) == SSA_NAME) |
22fca489 | 1251 | { |
f5299992 AH |
1252 | value_range vr; |
1253 | rvals->range_of_expr (vr, si->nonzero_chars, stmt); | |
1254 | if (range_int_cst_p (&vr)) | |
22fca489 | 1255 | { |
f5299992 AH |
1256 | pdata->minlen = vr.min (); |
1257 | pdata->maxlen = vr.max (); | |
22fca489 MS |
1258 | pdata->maxbound = pdata->maxlen; |
1259 | } | |
1260 | else | |
1261 | { | |
1262 | pdata->minlen = build_zero_cst (size_type_node); | |
1263 | pdata->maxlen = build_all_ones_cst (size_type_node); | |
1264 | } | |
1265 | } | |
93163192 | 1266 | else if (pdata->minlen && TREE_CODE (pdata->minlen) == INTEGER_CST) |
22fca489 MS |
1267 | { |
1268 | pdata->maxlen = pdata->minlen; | |
1269 | pdata->maxbound = pdata->minlen; | |
1270 | } | |
93163192 MS |
1271 | else |
1272 | { | |
1273 | /* For PDATA->MINLEN that's a non-constant expression such | |
1274 | as PLUS_EXPR whose value range is unknown, set the bounds | |
1275 | to zero and SIZE_MAX. */ | |
1276 | pdata->minlen = build_zero_cst (size_type_node); | |
1277 | pdata->maxlen = build_all_ones_cst (size_type_node); | |
1278 | } | |
22fca489 MS |
1279 | |
1280 | return true; | |
1281 | } | |
1282 | ||
1283 | return false; | |
1284 | } | |
1285 | ||
1286 | /* Analogous to get_range_strlen but for dynamically created strings, | |
1287 | i.e., those created by calls to strcpy as opposed to just string | |
1288 | constants. | |
1289 | Try to obtain the range of the lengths of the string(s) referenced | |
1290 | by SRC, or the size of the largest array SRC refers to if the range | |
1291 | of lengths cannot be determined, and store all in *PDATA. RVALS | |
f5299992 | 1292 | points to the valuation engine used to calculate ranges. */ |
22fca489 MS |
1293 | |
1294 | void | |
f5299992 AH |
1295 | get_range_strlen_dynamic (tree src, gimple *stmt, c_strlen_data *pdata, |
1296 | range_query *rvals) | |
22fca489 | 1297 | { |
ba6e17e7 | 1298 | auto_bitmap visited; |
a7160771 | 1299 | tree maxbound = pdata->maxbound; |
22fca489 | 1300 | |
028d4092 | 1301 | unsigned limit = param_ssa_name_def_chain_limit; |
ba6e17e7 | 1302 | if (!get_range_strlen_dynamic (src, stmt, pdata, visited, rvals, &limit)) |
22fca489 MS |
1303 | { |
1304 | /* On failure extend the length range to an impossible maximum | |
1305 | (a valid MAXLEN must be less than PTRDIFF_MAX - 1). Other | |
1306 | members can stay unchanged regardless. */ | |
1307 | pdata->minlen = ssize_int (0); | |
1308 | pdata->maxlen = build_all_ones_cst (size_type_node); | |
1309 | } | |
1310 | else if (!pdata->minlen) | |
1311 | pdata->minlen = ssize_int (0); | |
1312 | ||
a7160771 MS |
1313 | /* If it's unchanged from it initial non-null value, set the conservative |
1314 | MAXBOUND to SIZE_MAX. Otherwise leave it null (if it is null). */ | |
1315 | if (maxbound && pdata->maxbound == maxbound) | |
1316 | pdata->maxbound = build_all_ones_cst (size_type_node); | |
22fca489 MS |
1317 | } |
1318 | ||
ef29b12c MS |
1319 | /* Invalidate string length information for strings whose length might |
1320 | change due to stores in STMT, except those marked DONT_INVALIDATE. | |
1321 | For string-modifying statements, ZERO_WRITE is set when the statement | |
1322 | wrote only zeros. | |
1323 | Returns true if any STRIDX_TO_STRINFO entries were considered | |
1324 | for invalidation. */ | |
8b57bfeb JJ |
1325 | |
1326 | static bool | |
2fcb55d1 | 1327 | maybe_invalidate (gimple *stmt, bool zero_write = false) |
8b57bfeb | 1328 | { |
2fcb55d1 | 1329 | if (dump_file && (dump_flags & TDF_DETAILS)) |
ef29b12c MS |
1330 | { |
1331 | fprintf (dump_file, "%s called for ", __func__); | |
1332 | print_gimple_stmt (dump_file, stmt, TDF_LINENO); | |
1333 | } | |
2fcb55d1 | 1334 | |
526ceb68 | 1335 | strinfo *si; |
8b57bfeb JJ |
1336 | bool nonempty = false; |
1337 | ||
ef29b12c MS |
1338 | for (unsigned i = 1; vec_safe_iterate (stridx_to_strinfo, i, &si); ++i) |
1339 | { | |
1340 | if (si == NULL || !POINTER_TYPE_P (TREE_TYPE (si->ptr))) | |
1341 | continue; | |
2fcb55d1 | 1342 | |
ef29b12c | 1343 | nonempty = true; |
2fcb55d1 | 1344 | |
ef29b12c MS |
1345 | /* Unconditionally reset DONT_INVALIDATE. */ |
1346 | bool dont_invalidate = si->dont_invalidate; | |
1347 | si->dont_invalidate = false; | |
1348 | ||
1349 | if (dont_invalidate) | |
1350 | continue; | |
1351 | ||
1352 | ao_ref r; | |
08ce1f4c RB |
1353 | tree size = si->nonzero_chars; |
1354 | ao_ref_init_from_ptr_and_size (&r, si->ptr, size); | |
1355 | /* Include the terminating nul in the size of the string | |
1356 | to consider when determining possible clobber. But do not | |
1357 | add it to 'size' since we don't know whether it would | |
1358 | actually fit the allocated area. */ | |
1359 | if (known_size_p (r.size)) | |
ef29b12c | 1360 | { |
08ce1f4c RB |
1361 | if (known_le (r.size, HOST_WIDE_INT_MAX - BITS_PER_UNIT)) |
1362 | r.max_size += BITS_PER_UNIT; | |
1363 | else | |
1364 | r.max_size = -1; | |
ef29b12c | 1365 | } |
ef29b12c MS |
1366 | if (stmt_may_clobber_ref_p_1 (stmt, &r)) |
1367 | { | |
1368 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1369 | { | |
1370 | fputs (" statement may clobber object ", dump_file); | |
1371 | print_generic_expr (dump_file, si->ptr); | |
1372 | if (size && tree_fits_uhwi_p (size)) | |
1373 | fprintf (dump_file, " " HOST_WIDE_INT_PRINT_UNSIGNED | |
1374 | " bytes in size", tree_to_uhwi (size)); | |
1375 | fputc ('\n', dump_file); | |
1376 | } | |
1377 | ||
1378 | set_strinfo (i, NULL); | |
1379 | free_strinfo (si); | |
1380 | continue; | |
1381 | } | |
1382 | ||
1383 | if (size | |
1384 | && !zero_write | |
1385 | && si->stmt | |
1386 | && is_gimple_call (si->stmt) | |
1387 | && (DECL_FUNCTION_CODE (gimple_call_fndecl (si->stmt)) | |
1388 | == BUILT_IN_CALLOC)) | |
1389 | { | |
1390 | /* If the clobber test above considered the length of | |
1391 | the string (including the nul), then for (potentially) | |
1392 | non-zero writes that might modify storage allocated by | |
1393 | calloc consider the whole object and if it might be | |
1394 | clobbered by the statement reset the statement. */ | |
1395 | ao_ref_init_from_ptr_and_size (&r, si->ptr, NULL_TREE); | |
1396 | if (stmt_may_clobber_ref_p_1 (stmt, &r)) | |
1397 | si->stmt = NULL; | |
1398 | } | |
1399 | } | |
2fcb55d1 MS |
1400 | |
1401 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
ef29b12c | 1402 | fprintf (dump_file, "%s returns %i\n", __func__, nonempty); |
2fcb55d1 | 1403 | |
8b57bfeb JJ |
1404 | return nonempty; |
1405 | } | |
1406 | ||
204a913b | 1407 | /* Unshare strinfo record SI, if it has refcount > 1 or |
8b57bfeb JJ |
1408 | if stridx_to_strinfo vector is shared with some other |
1409 | bbs. */ | |
1410 | ||
526ceb68 TS |
1411 | static strinfo * |
1412 | unshare_strinfo (strinfo *si) | |
8b57bfeb | 1413 | { |
526ceb68 | 1414 | strinfo *nsi; |
8b57bfeb JJ |
1415 | |
1416 | if (si->refcount == 1 && !strinfo_shared ()) | |
1417 | return si; | |
1418 | ||
e3f9a279 | 1419 | nsi = new_strinfo (si->ptr, si->idx, si->nonzero_chars, si->full_string_p); |
8b57bfeb | 1420 | nsi->stmt = si->stmt; |
ef29b12c | 1421 | nsi->alloc = si->alloc; |
8b57bfeb JJ |
1422 | nsi->endptr = si->endptr; |
1423 | nsi->first = si->first; | |
1424 | nsi->prev = si->prev; | |
1425 | nsi->next = si->next; | |
1426 | nsi->writable = si->writable; | |
1427 | set_strinfo (si->idx, nsi); | |
1428 | free_strinfo (si); | |
1429 | return nsi; | |
1430 | } | |
1431 | ||
204a913b JJ |
1432 | /* Attempt to create a new strinfo for BASESI + OFF, or find existing |
1433 | strinfo if there is any. Return it's idx, or 0 if no strinfo has | |
1434 | been created. */ | |
1435 | ||
1436 | static int | |
e3f9a279 RS |
1437 | get_stridx_plus_constant (strinfo *basesi, unsigned HOST_WIDE_INT off, |
1438 | tree ptr) | |
204a913b | 1439 | { |
5f3cd7c3 | 1440 | if (TREE_CODE (ptr) == SSA_NAME && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ptr)) |
204a913b JJ |
1441 | return 0; |
1442 | ||
e3f9a279 RS |
1443 | if (compare_nonzero_chars (basesi, off) < 0 |
1444 | || !tree_fits_uhwi_p (basesi->nonzero_chars)) | |
204a913b JJ |
1445 | return 0; |
1446 | ||
e3f9a279 RS |
1447 | unsigned HOST_WIDE_INT nonzero_chars |
1448 | = tree_to_uhwi (basesi->nonzero_chars) - off; | |
526ceb68 | 1449 | strinfo *si = basesi, *chainsi; |
204a913b JJ |
1450 | if (si->first || si->prev || si->next) |
1451 | si = verify_related_strinfos (basesi); | |
1452 | if (si == NULL | |
e3f9a279 RS |
1453 | || si->nonzero_chars == NULL_TREE |
1454 | || TREE_CODE (si->nonzero_chars) != INTEGER_CST) | |
204a913b JJ |
1455 | return 0; |
1456 | ||
5f3cd7c3 JJ |
1457 | if (TREE_CODE (ptr) == SSA_NAME |
1458 | && ssa_ver_to_stridx.length () <= SSA_NAME_VERSION (ptr)) | |
cb3874dc | 1459 | ssa_ver_to_stridx.safe_grow_cleared (num_ssa_names, true); |
204a913b | 1460 | |
e3f9a279 | 1461 | gcc_checking_assert (compare_tree_int (si->nonzero_chars, off) != -1); |
204a913b JJ |
1462 | for (chainsi = si; chainsi->next; chainsi = si) |
1463 | { | |
bde63fde | 1464 | si = get_next_strinfo (chainsi); |
204a913b | 1465 | if (si == NULL |
e3f9a279 RS |
1466 | || si->nonzero_chars == NULL_TREE |
1467 | || TREE_CODE (si->nonzero_chars) != INTEGER_CST) | |
204a913b | 1468 | break; |
e3f9a279 | 1469 | int r = compare_tree_int (si->nonzero_chars, nonzero_chars); |
204a913b JJ |
1470 | if (r != 1) |
1471 | { | |
1472 | if (r == 0) | |
1473 | { | |
55a0f21a JJ |
1474 | if (TREE_CODE (ptr) == SSA_NAME) |
1475 | ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)] = si->idx; | |
1476 | else | |
1477 | { | |
1478 | int *pidx = addr_stridxptr (TREE_OPERAND (ptr, 0)); | |
1479 | if (pidx != NULL && *pidx == 0) | |
1480 | *pidx = si->idx; | |
1481 | } | |
204a913b JJ |
1482 | return si->idx; |
1483 | } | |
1484 | break; | |
1485 | } | |
1486 | } | |
1487 | ||
1488 | int idx = new_stridx (ptr); | |
1489 | if (idx == 0) | |
1490 | return 0; | |
e3f9a279 RS |
1491 | si = new_strinfo (ptr, idx, build_int_cst (size_type_node, nonzero_chars), |
1492 | basesi->full_string_p); | |
204a913b | 1493 | set_strinfo (idx, si); |
9c8c7338 | 1494 | if (strinfo *nextsi = get_strinfo (chainsi->next)) |
204a913b | 1495 | { |
9c8c7338 | 1496 | nextsi = unshare_strinfo (nextsi); |
204a913b JJ |
1497 | si->next = nextsi->idx; |
1498 | nextsi->prev = idx; | |
1499 | } | |
1500 | chainsi = unshare_strinfo (chainsi); | |
1501 | if (chainsi->first == 0) | |
1502 | chainsi->first = chainsi->idx; | |
1503 | chainsi->next = idx; | |
e3f9a279 | 1504 | if (chainsi->endptr == NULL_TREE && zero_length_string_p (si)) |
204a913b JJ |
1505 | chainsi->endptr = ptr; |
1506 | si->endptr = chainsi->endptr; | |
1507 | si->prev = chainsi->idx; | |
1508 | si->first = chainsi->first; | |
1509 | si->writable = chainsi->writable; | |
1510 | return si->idx; | |
1511 | } | |
1512 | ||
8b57bfeb JJ |
1513 | /* Note that PTR, a pointer SSA_NAME initialized in the current stmt, points |
1514 | to a zero-length string and if possible chain it to a related strinfo | |
1515 | chain whose part is or might be CHAINSI. */ | |
1516 | ||
526ceb68 TS |
1517 | static strinfo * |
1518 | zero_length_string (tree ptr, strinfo *chainsi) | |
8b57bfeb | 1519 | { |
526ceb68 | 1520 | strinfo *si; |
8b57bfeb | 1521 | int idx; |
204a913b | 1522 | if (ssa_ver_to_stridx.length () <= SSA_NAME_VERSION (ptr)) |
cb3874dc | 1523 | ssa_ver_to_stridx.safe_grow_cleared (num_ssa_names, true); |
8b57bfeb | 1524 | gcc_checking_assert (TREE_CODE (ptr) == SSA_NAME |
204a913b | 1525 | && ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)] == 0); |
8b57bfeb JJ |
1526 | |
1527 | if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ptr)) | |
1528 | return NULL; | |
1529 | if (chainsi != NULL) | |
1530 | { | |
1531 | si = verify_related_strinfos (chainsi); | |
1532 | if (si) | |
1533 | { | |
bde63fde | 1534 | do |
8b57bfeb | 1535 | { |
862088aa | 1536 | /* We shouldn't mix delayed and non-delayed lengths. */ |
e3f9a279 | 1537 | gcc_assert (si->full_string_p); |
bde63fde | 1538 | if (si->endptr == NULL_TREE) |
8b57bfeb | 1539 | { |
bde63fde RS |
1540 | si = unshare_strinfo (si); |
1541 | si->endptr = ptr; | |
8b57bfeb | 1542 | } |
bde63fde RS |
1543 | chainsi = si; |
1544 | si = get_next_strinfo (si); | |
8b57bfeb | 1545 | } |
bde63fde | 1546 | while (si != NULL); |
e3f9a279 | 1547 | if (zero_length_string_p (chainsi)) |
8b57bfeb JJ |
1548 | { |
1549 | if (chainsi->next) | |
1550 | { | |
1551 | chainsi = unshare_strinfo (chainsi); | |
1552 | chainsi->next = 0; | |
1553 | } | |
9771b263 | 1554 | ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)] = chainsi->idx; |
8b57bfeb JJ |
1555 | return chainsi; |
1556 | } | |
1557 | } | |
862088aa | 1558 | else |
8b57bfeb | 1559 | { |
862088aa | 1560 | /* We shouldn't mix delayed and non-delayed lengths. */ |
e3f9a279 | 1561 | gcc_assert (chainsi->full_string_p); |
862088aa RS |
1562 | if (chainsi->first || chainsi->prev || chainsi->next) |
1563 | { | |
1564 | chainsi = unshare_strinfo (chainsi); | |
1565 | chainsi->first = 0; | |
1566 | chainsi->prev = 0; | |
1567 | chainsi->next = 0; | |
1568 | } | |
8b57bfeb JJ |
1569 | } |
1570 | } | |
1571 | idx = new_stridx (ptr); | |
1572 | if (idx == 0) | |
1573 | return NULL; | |
e3f9a279 | 1574 | si = new_strinfo (ptr, idx, build_int_cst (size_type_node, 0), true); |
8b57bfeb JJ |
1575 | set_strinfo (idx, si); |
1576 | si->endptr = ptr; | |
1577 | if (chainsi != NULL) | |
1578 | { | |
1579 | chainsi = unshare_strinfo (chainsi); | |
1580 | if (chainsi->first == 0) | |
1581 | chainsi->first = chainsi->idx; | |
1582 | chainsi->next = idx; | |
93a90db6 AK |
1583 | if (chainsi->endptr == NULL_TREE) |
1584 | chainsi->endptr = ptr; | |
8b57bfeb JJ |
1585 | si->prev = chainsi->idx; |
1586 | si->first = chainsi->first; | |
1587 | si->writable = chainsi->writable; | |
1588 | } | |
1589 | return si; | |
1590 | } | |
1591 | ||
e3f9a279 RS |
1592 | /* For strinfo ORIGSI whose length has been just updated, adjust other |
1593 | related strinfos so that they match the new ORIGSI. This involves: | |
1594 | ||
1595 | - adding ADJ to the nonzero_chars fields | |
1596 | - copying full_string_p from the new ORIGSI. */ | |
8b57bfeb JJ |
1597 | |
1598 | static void | |
526ceb68 | 1599 | adjust_related_strinfos (location_t loc, strinfo *origsi, tree adj) |
8b57bfeb | 1600 | { |
526ceb68 | 1601 | strinfo *si = verify_related_strinfos (origsi); |
8b57bfeb JJ |
1602 | |
1603 | if (si == NULL) | |
1604 | return; | |
1605 | ||
1606 | while (1) | |
1607 | { | |
526ceb68 | 1608 | strinfo *nsi; |
8b57bfeb JJ |
1609 | |
1610 | if (si != origsi) | |
1611 | { | |
1612 | tree tem; | |
1613 | ||
1614 | si = unshare_strinfo (si); | |
21722777 MS |
1615 | /* We shouldn't see delayed lengths here; the caller must |
1616 | have calculated the old length in order to calculate | |
1617 | the adjustment. */ | |
e3f9a279 RS |
1618 | gcc_assert (si->nonzero_chars); |
1619 | tem = fold_convert_loc (loc, TREE_TYPE (si->nonzero_chars), adj); | |
1620 | si->nonzero_chars = fold_build2_loc (loc, PLUS_EXPR, | |
1621 | TREE_TYPE (si->nonzero_chars), | |
1622 | si->nonzero_chars, tem); | |
1623 | si->full_string_p = origsi->full_string_p; | |
93a90db6 | 1624 | |
8b57bfeb JJ |
1625 | si->endptr = NULL_TREE; |
1626 | si->dont_invalidate = true; | |
1627 | } | |
bde63fde RS |
1628 | nsi = get_next_strinfo (si); |
1629 | if (nsi == NULL) | |
8b57bfeb JJ |
1630 | return; |
1631 | si = nsi; | |
1632 | } | |
1633 | } | |
1634 | ||
1635 | /* Find if there are other SSA_NAME pointers equal to PTR | |
1636 | for which we don't track their string lengths yet. If so, use | |
1637 | IDX for them. */ | |
1638 | ||
1639 | static void | |
1640 | find_equal_ptrs (tree ptr, int idx) | |
1641 | { | |
1642 | if (TREE_CODE (ptr) != SSA_NAME) | |
1643 | return; | |
1644 | while (1) | |
1645 | { | |
355fe088 | 1646 | gimple *stmt = SSA_NAME_DEF_STMT (ptr); |
8b57bfeb JJ |
1647 | if (!is_gimple_assign (stmt)) |
1648 | return; | |
1649 | ptr = gimple_assign_rhs1 (stmt); | |
1650 | switch (gimple_assign_rhs_code (stmt)) | |
1651 | { | |
1652 | case SSA_NAME: | |
1653 | break; | |
97246d78 JJ |
1654 | CASE_CONVERT: |
1655 | if (!POINTER_TYPE_P (TREE_TYPE (ptr))) | |
1656 | return; | |
1657 | if (TREE_CODE (ptr) == SSA_NAME) | |
1658 | break; | |
1659 | if (TREE_CODE (ptr) != ADDR_EXPR) | |
1660 | return; | |
1661 | /* FALLTHRU */ | |
8b57bfeb JJ |
1662 | case ADDR_EXPR: |
1663 | { | |
1664 | int *pidx = addr_stridxptr (TREE_OPERAND (ptr, 0)); | |
1665 | if (pidx != NULL && *pidx == 0) | |
1666 | *pidx = idx; | |
1667 | return; | |
1668 | } | |
8b57bfeb JJ |
1669 | default: |
1670 | return; | |
1671 | } | |
1672 | ||
1673 | /* We might find an endptr created in this pass. Grow the | |
1674 | vector in that case. */ | |
9771b263 | 1675 | if (ssa_ver_to_stridx.length () <= SSA_NAME_VERSION (ptr)) |
cb3874dc | 1676 | ssa_ver_to_stridx.safe_grow_cleared (num_ssa_names, true); |
8b57bfeb | 1677 | |
9771b263 | 1678 | if (ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)] != 0) |
8b57bfeb | 1679 | return; |
9771b263 | 1680 | ssa_ver_to_stridx[SSA_NAME_VERSION (ptr)] = idx; |
8b57bfeb JJ |
1681 | } |
1682 | } | |
1683 | ||
0ad84f34 JJ |
1684 | /* Return true if STMT is a call to a builtin function with the right |
1685 | arguments and attributes that should be considered for optimization | |
1686 | by this pass. */ | |
1687 | ||
1688 | static bool | |
1689 | valid_builtin_call (gimple *stmt) | |
1690 | { | |
1691 | if (!gimple_call_builtin_p (stmt, BUILT_IN_NORMAL)) | |
1692 | return false; | |
1693 | ||
1694 | tree callee = gimple_call_fndecl (stmt); | |
f54e63df JJ |
1695 | tree decl = builtin_decl_explicit (DECL_FUNCTION_CODE (callee)); |
1696 | if (decl | |
1697 | && decl != callee | |
1698 | && !gimple_builtin_call_types_compatible_p (stmt, decl)) | |
1699 | return false; | |
1700 | ||
0ad84f34 JJ |
1701 | switch (DECL_FUNCTION_CODE (callee)) |
1702 | { | |
1703 | case BUILT_IN_MEMCMP: | |
1704 | case BUILT_IN_MEMCMP_EQ: | |
f54e63df JJ |
1705 | case BUILT_IN_STRCMP: |
1706 | case BUILT_IN_STRNCMP: | |
0ad84f34 | 1707 | case BUILT_IN_STRCHR: |
0ad84f34 | 1708 | case BUILT_IN_STRLEN: |
f54e63df | 1709 | case BUILT_IN_STRNLEN: |
0ad84f34 JJ |
1710 | /* The above functions should be pure. Punt if they aren't. */ |
1711 | if (gimple_vdef (stmt) || gimple_vuse (stmt) == NULL_TREE) | |
1712 | return false; | |
1713 | break; | |
1714 | ||
ef29b12c MS |
1715 | case BUILT_IN_ALLOCA: |
1716 | case BUILT_IN_ALLOCA_WITH_ALIGN: | |
0ad84f34 JJ |
1717 | case BUILT_IN_CALLOC: |
1718 | case BUILT_IN_MALLOC: | |
1719 | case BUILT_IN_MEMCPY: | |
1720 | case BUILT_IN_MEMCPY_CHK: | |
0ad84f34 JJ |
1721 | case BUILT_IN_MEMPCPY: |
1722 | case BUILT_IN_MEMPCPY_CHK: | |
0ad84f34 JJ |
1723 | case BUILT_IN_MEMSET: |
1724 | case BUILT_IN_STPCPY: | |
1725 | case BUILT_IN_STPCPY_CHK: | |
f54e63df JJ |
1726 | case BUILT_IN_STPNCPY: |
1727 | case BUILT_IN_STPNCPY_CHK: | |
0ad84f34 JJ |
1728 | case BUILT_IN_STRCAT: |
1729 | case BUILT_IN_STRCAT_CHK: | |
0ad84f34 JJ |
1730 | case BUILT_IN_STRCPY: |
1731 | case BUILT_IN_STRCPY_CHK: | |
f54e63df JJ |
1732 | case BUILT_IN_STRNCAT: |
1733 | case BUILT_IN_STRNCAT_CHK: | |
1734 | case BUILT_IN_STRNCPY: | |
1735 | case BUILT_IN_STRNCPY_CHK: | |
0ad84f34 JJ |
1736 | /* The above functions should be neither const nor pure. Punt if they |
1737 | aren't. */ | |
1738 | if (gimple_vdef (stmt) == NULL_TREE || gimple_vuse (stmt) == NULL_TREE) | |
1739 | return false; | |
1740 | break; | |
1741 | ||
1742 | default: | |
1743 | break; | |
1744 | } | |
1745 | ||
1746 | return true; | |
1747 | } | |
1748 | ||
8b57bfeb JJ |
1749 | /* If the last .MEM setter statement before STMT is |
1750 | memcpy (x, y, strlen (y) + 1), the only .MEM use of it is STMT | |
1751 | and STMT is known to overwrite x[strlen (x)], adjust the last memcpy to | |
1752 | just memcpy (x, y, strlen (y)). SI must be the zero length | |
1753 | strinfo. */ | |
1754 | ||
47e4ab65 AH |
1755 | void |
1756 | strlen_pass::adjust_last_stmt (strinfo *si, gimple *stmt, bool is_strcat) | |
8b57bfeb JJ |
1757 | { |
1758 | tree vuse, callee, len; | |
1759 | struct laststmt_struct last = laststmt; | |
526ceb68 | 1760 | strinfo *lastsi, *firstsi; |
f5fc4a04 | 1761 | unsigned len_arg_no = 2; |
8b57bfeb JJ |
1762 | |
1763 | laststmt.stmt = NULL; | |
1764 | laststmt.len = NULL_TREE; | |
1765 | laststmt.stridx = 0; | |
1766 | ||
1767 | if (last.stmt == NULL) | |
1768 | return; | |
1769 | ||
1770 | vuse = gimple_vuse (stmt); | |
1771 | if (vuse == NULL_TREE | |
1772 | || SSA_NAME_DEF_STMT (vuse) != last.stmt | |
1773 | || !has_single_use (vuse)) | |
1774 | return; | |
1775 | ||
1776 | gcc_assert (last.stridx > 0); | |
1777 | lastsi = get_strinfo (last.stridx); | |
1778 | if (lastsi == NULL) | |
1779 | return; | |
1780 | ||
1781 | if (lastsi != si) | |
1782 | { | |
1783 | if (lastsi->first == 0 || lastsi->first != si->first) | |
1784 | return; | |
1785 | ||
1786 | firstsi = verify_related_strinfos (si); | |
1787 | if (firstsi == NULL) | |
1788 | return; | |
1789 | while (firstsi != lastsi) | |
1790 | { | |
bde63fde RS |
1791 | firstsi = get_next_strinfo (firstsi); |
1792 | if (firstsi == NULL) | |
8b57bfeb | 1793 | return; |
8b57bfeb JJ |
1794 | } |
1795 | } | |
1796 | ||
e3f9a279 RS |
1797 | if (!is_strcat && !zero_length_string_p (si)) |
1798 | return; | |
8b57bfeb JJ |
1799 | |
1800 | if (is_gimple_assign (last.stmt)) | |
1801 | { | |
1802 | gimple_stmt_iterator gsi; | |
1803 | ||
1804 | if (!integer_zerop (gimple_assign_rhs1 (last.stmt))) | |
1805 | return; | |
36bbc05d | 1806 | if (stmt_could_throw_p (cfun, last.stmt)) |
8b57bfeb JJ |
1807 | return; |
1808 | gsi = gsi_for_stmt (last.stmt); | |
1809 | unlink_stmt_vdef (last.stmt); | |
1810 | release_defs (last.stmt); | |
1811 | gsi_remove (&gsi, true); | |
1812 | return; | |
1813 | } | |
1814 | ||
0ad84f34 | 1815 | if (!valid_builtin_call (last.stmt)) |
8b57bfeb JJ |
1816 | return; |
1817 | ||
3626621a | 1818 | callee = gimple_call_fndecl (last.stmt); |
8b57bfeb JJ |
1819 | switch (DECL_FUNCTION_CODE (callee)) |
1820 | { | |
1821 | case BUILT_IN_MEMCPY: | |
1822 | case BUILT_IN_MEMCPY_CHK: | |
1823 | break; | |
1824 | default: | |
1825 | return; | |
1826 | } | |
1827 | ||
f5fc4a04 | 1828 | len = gimple_call_arg (last.stmt, len_arg_no); |
cc269bb6 | 1829 | if (tree_fits_uhwi_p (len)) |
8b57bfeb | 1830 | { |
cc269bb6 | 1831 | if (!tree_fits_uhwi_p (last.len) |
8b57bfeb | 1832 | || integer_zerop (len) |
7d362f6c | 1833 | || tree_to_uhwi (len) != tree_to_uhwi (last.len) + 1) |
8b57bfeb JJ |
1834 | return; |
1835 | /* Don't adjust the length if it is divisible by 4, it is more efficient | |
1836 | to store the extra '\0' in that case. */ | |
7d362f6c | 1837 | if ((tree_to_uhwi (len) & 3) == 0) |
8b57bfeb | 1838 | return; |
7d4ae1fb BE |
1839 | |
1840 | /* Don't fold away an out of bounds access, as this defeats proper | |
1841 | warnings. */ | |
1842 | tree dst = gimple_call_arg (last.stmt, 0); | |
d02c41dd MS |
1843 | |
1844 | access_ref aref; | |
9a27acc3 | 1845 | tree size = compute_objsize (dst, stmt, 1, &aref, &ptr_qry); |
7d4ae1fb BE |
1846 | if (size && tree_int_cst_lt (size, len)) |
1847 | return; | |
8b57bfeb JJ |
1848 | } |
1849 | else if (TREE_CODE (len) == SSA_NAME) | |
1850 | { | |
355fe088 | 1851 | gimple *def_stmt = SSA_NAME_DEF_STMT (len); |
8b57bfeb JJ |
1852 | if (!is_gimple_assign (def_stmt) |
1853 | || gimple_assign_rhs_code (def_stmt) != PLUS_EXPR | |
1854 | || gimple_assign_rhs1 (def_stmt) != last.len | |
1855 | || !integer_onep (gimple_assign_rhs2 (def_stmt))) | |
1856 | return; | |
1857 | } | |
1858 | else | |
1859 | return; | |
1860 | ||
f5fc4a04 | 1861 | gimple_call_set_arg (last.stmt, len_arg_no, last.len); |
8b57bfeb JJ |
1862 | update_stmt (last.stmt); |
1863 | } | |
1864 | ||
d4bf6975 MS |
1865 | /* For an LHS that is an SSA_NAME that is the result of a strlen() |
1866 | call, or when BOUND is non-null, of a strnlen() call, set LHS | |
1867 | range info to [0, min (MAX, BOUND)] when the range includes more | |
1868 | than one value and return LHS. Otherwise, when the range | |
1869 | [MIN, MAX] is such that MIN == MAX, return the tree representation | |
1870 | of (MIN). The latter allows callers to fold suitable strnlen() calls | |
1871 | to constants. */ | |
1872 | ||
1873 | tree | |
34fcf41e MS |
1874 | set_strlen_range (tree lhs, wide_int min, wide_int max, |
1875 | tree bound /* = NULL_TREE */) | |
06199618 | 1876 | { |
a7bf6c08 MS |
1877 | if (TREE_CODE (lhs) != SSA_NAME |
1878 | || !INTEGRAL_TYPE_P (TREE_TYPE (lhs))) | |
781ff3d8 | 1879 | return NULL_TREE; |
06199618 | 1880 | |
781ff3d8 MS |
1881 | if (bound) |
1882 | { | |
1883 | /* For strnlen, adjust MIN and MAX as necessary. If the bound | |
1884 | is less than the size of the array set MAX to it. It it's | |
1885 | greater than MAX and MAX is non-zero bump MAX down to account | |
1886 | for the necessary terminating nul. Otherwise leave it alone. */ | |
1887 | if (TREE_CODE (bound) == INTEGER_CST) | |
1888 | { | |
1889 | wide_int wibnd = wi::to_wide (bound); | |
1890 | int cmp = wi::cmpu (wibnd, max); | |
1891 | if (cmp < 0) | |
1892 | max = wibnd; | |
1893 | else if (cmp && wi::ne_p (max, min)) | |
1894 | --max; | |
1895 | } | |
1896 | else if (TREE_CODE (bound) == SSA_NAME) | |
1897 | { | |
45f4e2b0 AH |
1898 | value_range r; |
1899 | get_range_query (cfun)->range_of_expr (r, bound); | |
1900 | if (!r.undefined_p ()) | |
781ff3d8 MS |
1901 | { |
1902 | /* For a bound in a known range, adjust the range determined | |
1903 | above as necessary. For a bound in some anti-range or | |
d4bf6975 | 1904 | in an unknown range, use the range determined by callers. */ |
45f4e2b0 AH |
1905 | if (wi::ltu_p (r.lower_bound (), min)) |
1906 | min = r.lower_bound (); | |
1907 | if (wi::ltu_p (r.upper_bound (), max)) | |
1908 | max = r.upper_bound (); | |
781ff3d8 MS |
1909 | } |
1910 | } | |
1911 | } | |
1912 | ||
1913 | if (min == max) | |
1914 | return wide_int_to_tree (size_type_node, min); | |
1915 | ||
1916 | set_range_info (lhs, VR_RANGE, min, max); | |
1917 | return lhs; | |
06199618 MS |
1918 | } |
1919 | ||
d4bf6975 MS |
1920 | /* For an LHS that is an SSA_NAME and for strlen() or strnlen() argument |
1921 | SRC, set LHS range info to [0, min (N, BOUND)] if SRC refers to | |
1922 | a character array A[N] with unknown length bounded by N, and for | |
1923 | strnlen(), by min (N, BOUND). */ | |
1924 | ||
1925 | static tree | |
1926 | maybe_set_strlen_range (tree lhs, tree src, tree bound) | |
1927 | { | |
1928 | if (TREE_CODE (lhs) != SSA_NAME | |
1929 | || !INTEGRAL_TYPE_P (TREE_TYPE (lhs))) | |
1930 | return NULL_TREE; | |
1931 | ||
1932 | if (TREE_CODE (src) == SSA_NAME) | |
1933 | { | |
1934 | gimple *def = SSA_NAME_DEF_STMT (src); | |
1935 | if (is_gimple_assign (def) | |
1936 | && gimple_assign_rhs_code (def) == ADDR_EXPR) | |
1937 | src = gimple_assign_rhs1 (def); | |
1938 | } | |
1939 | ||
1940 | /* The longest string is PTRDIFF_MAX - 1 bytes including the final | |
1941 | NUL so that the difference between a pointer to just past it and | |
1942 | one to its beginning is positive. */ | |
1943 | wide_int max = wi::to_wide (TYPE_MAX_VALUE (ptrdiff_type_node)) - 2; | |
1944 | ||
1945 | if (TREE_CODE (src) == ADDR_EXPR) | |
1946 | { | |
1947 | /* The last array member of a struct can be bigger than its size | |
1948 | suggests if it's treated as a poor-man's flexible array member. */ | |
1949 | src = TREE_OPERAND (src, 0); | |
1950 | if (TREE_CODE (src) != MEM_REF | |
1951 | && !array_at_struct_end_p (src)) | |
1952 | { | |
1953 | tree type = TREE_TYPE (src); | |
1954 | tree size = TYPE_SIZE_UNIT (type); | |
1955 | if (size | |
1956 | && TREE_CODE (size) == INTEGER_CST | |
1957 | && !integer_zerop (size)) | |
1958 | { | |
1959 | /* Even though such uses of strlen would be undefined, | |
1960 | avoid relying on arrays of arrays in case some genius | |
1961 | decides to call strlen on an unterminated array element | |
1962 | that's followed by a terminated one. Likewise, avoid | |
1963 | assuming that a struct array member is necessarily | |
1964 | nul-terminated (the nul may be in the member that | |
1965 | follows). In those cases, assume that the length | |
1966 | of the string stored in such an array is bounded | |
1967 | by the size of the enclosing object if one can be | |
1968 | determined. */ | |
1969 | tree base = get_base_address (src); | |
1970 | if (VAR_P (base)) | |
1971 | { | |
1972 | if (tree size = DECL_SIZE_UNIT (base)) | |
1973 | if (size | |
1974 | && TREE_CODE (size) == INTEGER_CST | |
1975 | && TREE_CODE (TREE_TYPE (base)) != POINTER_TYPE) | |
1976 | max = wi::to_wide (size); | |
1977 | } | |
1978 | } | |
1979 | ||
1980 | /* For strlen() the upper bound above is equal to | |
1981 | the longest string that can be stored in the array | |
1982 | (i.e., it accounts for the terminating nul. For | |
1983 | strnlen() bump up the maximum by one since the array | |
1984 | need not be nul-terminated. */ | |
1985 | if (!bound && max != 0) | |
1986 | --max; | |
1987 | } | |
1988 | } | |
1989 | ||
34fcf41e MS |
1990 | wide_int min = wi::zero (max.get_precision ()); |
1991 | return set_strlen_range (lhs, min, max, bound); | |
d4bf6975 MS |
1992 | } |
1993 | ||
f7d86b5c | 1994 | /* Diagnose buffer overflow by a STMT writing LEN + PLUS_ONE bytes, |
ef29b12c MS |
1995 | either into a region allocated for the object SI when non-null, |
1996 | or into an object designated by the LHS of STMT otherwise. | |
f0500db3 MS |
1997 | For a call STMT, when CALL_LHS is set use its left hand side |
1998 | as the destination, otherwise use argument zero. | |
ef29b12c MS |
1999 | When nonnull uses RVALS to determine range information. |
2000 | RAWMEM may be set by memcpy and other raw memory functions | |
2001 | to allow accesses across subobject boundaries. */ | |
f7d86b5c | 2002 | |
47e4ab65 AH |
2003 | void |
2004 | strlen_pass::maybe_warn_overflow (gimple *stmt, bool call_lhs, tree len, | |
2005 | strinfo *si, bool plus_one, bool rawmem) | |
f7d86b5c | 2006 | { |
e9e2bad7 | 2007 | if (!len || warning_suppressed_p (stmt, OPT_Wstringop_overflow_)) |
f7d86b5c MS |
2008 | return; |
2009 | ||
ef29b12c MS |
2010 | /* The DECL of the function performing the write if it is done |
2011 | by one. */ | |
f7d86b5c | 2012 | tree writefn = NULL_TREE; |
f0500db3 | 2013 | /* The destination expression involved in the store or call STMT. */ |
f7d86b5c MS |
2014 | tree dest = NULL_TREE; |
2015 | ||
f7d86b5c | 2016 | if (is_gimple_assign (stmt)) |
ef29b12c | 2017 | dest = gimple_assign_lhs (stmt); |
f7d86b5c MS |
2018 | else if (is_gimple_call (stmt)) |
2019 | { | |
f0500db3 MS |
2020 | if (call_lhs) |
2021 | dest = gimple_call_lhs (stmt); | |
2022 | else | |
2023 | { | |
2024 | gcc_assert (gimple_call_builtin_p (stmt, BUILT_IN_NORMAL)); | |
2025 | dest = gimple_call_arg (stmt, 0); | |
2026 | } | |
2027 | ||
2028 | if (!dest) | |
2029 | return; | |
ef29b12c | 2030 | writefn = gimple_call_fndecl (stmt); |
f7d86b5c | 2031 | } |
eafe8ee7 MS |
2032 | else |
2033 | return; | |
f7d86b5c | 2034 | |
e9e2bad7 | 2035 | if (warning_suppressed_p (dest, OPT_Wstringop_overflow_)) |
ef29b12c MS |
2036 | return; |
2037 | ||
d02c41dd MS |
2038 | const int ostype = rawmem ? 0 : 1; |
2039 | ||
10bbbb59 MS |
2040 | /* Use maximum precision to avoid overflow in the addition below. |
2041 | Make sure all operands have the same precision to keep wide_int | |
2042 | from ICE'ing. */ | |
2043 | ||
eafe8ee7 | 2044 | access_ref aref; |
ef29b12c MS |
2045 | /* The size of the destination region (which is smaller than |
2046 | the destination object for stores at a non-zero offset). */ | |
9a27acc3 | 2047 | tree destsize = compute_objsize (dest, stmt, ostype, &aref, &ptr_qry); |
d02c41dd | 2048 | |
ef29b12c MS |
2049 | if (!destsize) |
2050 | { | |
eafe8ee7 MS |
2051 | aref.sizrng[0] = 0; |
2052 | aref.sizrng[1] = wi::to_offset (max_object_size ()); | |
f7d86b5c MS |
2053 | } |
2054 | ||
2055 | /* Return early if the DESTSIZE size expression is the same as LEN | |
2056 | and the offset into the destination is zero. This might happen | |
2057 | in the case of a pair of malloc and memset calls to allocate | |
2058 | an object and clear it as if by calloc. */ | |
eafe8ee7 MS |
2059 | if (destsize == len && !plus_one |
2060 | && aref.offrng[0] == 0 && aref.offrng[0] == aref.offrng[1]) | |
f7d86b5c MS |
2061 | return; |
2062 | ||
10bbbb59 | 2063 | wide_int rng[2]; |
d02c41dd | 2064 | if (!get_range (len, stmt, rng, ptr_qry.rvals)) |
f7d86b5c MS |
2065 | return; |
2066 | ||
10bbbb59 MS |
2067 | widest_int lenrng[2] = |
2068 | { widest_int::from (rng[0], SIGNED), widest_int::from (rng[1], SIGNED) }; | |
2069 | ||
f7d86b5c MS |
2070 | if (plus_one) |
2071 | { | |
2072 | lenrng[0] += 1; | |
2073 | lenrng[1] += 1; | |
2074 | } | |
2075 | ||
ef29b12c MS |
2076 | /* The size of the remaining space in the destination computed |
2077 | as the size of the latter minus the offset into it. */ | |
eafe8ee7 MS |
2078 | widest_int spcrng[2]; |
2079 | { | |
2080 | offset_int remrng[2]; | |
2081 | remrng[1] = aref.size_remaining (remrng); | |
2082 | spcrng[0] = remrng[0] == -1 ? 0 : widest_int::from (remrng[0], UNSIGNED); | |
2083 | spcrng[1] = widest_int::from (remrng[1], UNSIGNED); | |
2084 | } | |
f7d86b5c | 2085 | |
ef29b12c MS |
2086 | if (wi::leu_p (lenrng[0], spcrng[0]) |
2087 | && wi::leu_p (lenrng[1], spcrng[1])) | |
f7d86b5c MS |
2088 | return; |
2089 | ||
55ace4d1 | 2090 | location_t loc = gimple_or_expr_nonartificial_location (stmt, dest); |
f7d86b5c MS |
2091 | bool warned = false; |
2092 | if (wi::leu_p (lenrng[0], spcrng[1])) | |
2093 | { | |
2094 | if (len != destsize | |
7f5ff78f | 2095 | && (!si || rawmem || !is_strlen_related_p (si->ptr, len))) |
f7d86b5c MS |
2096 | return; |
2097 | ||
2098 | warned = (writefn | |
2099 | ? warning_at (loc, OPT_Wstringop_overflow_, | |
6d3bab5d | 2100 | "%qD writing one too many bytes into a region " |
f7d86b5c | 2101 | "of a size that depends on %<strlen%>", |
6d3bab5d | 2102 | writefn) |
f7d86b5c | 2103 | : warning_at (loc, OPT_Wstringop_overflow_, |
6d3bab5d MS |
2104 | "writing one too many bytes into a region " |
2105 | "of a size that depends on %<strlen%>")); | |
f7d86b5c MS |
2106 | } |
2107 | else if (lenrng[0] == lenrng[1]) | |
2108 | { | |
2109 | if (spcrng[0] == spcrng[1]) | |
2110 | warned = (writefn | |
2111 | ? warning_n (loc, OPT_Wstringop_overflow_, | |
2112 | lenrng[0].to_uhwi (), | |
6d3bab5d | 2113 | "%qD writing %wu byte into a region " |
f7d86b5c | 2114 | "of size %wu", |
6d3bab5d | 2115 | "%qD writing %wu bytes into a region " |
f7d86b5c | 2116 | "of size %wu", |
6d3bab5d | 2117 | writefn, lenrng[0].to_uhwi (), |
f7d86b5c MS |
2118 | spcrng[0].to_uhwi ()) |
2119 | : warning_n (loc, OPT_Wstringop_overflow_, | |
2120 | lenrng[0].to_uhwi (), | |
6d3bab5d | 2121 | "writing %wu byte into a region " |
f7d86b5c | 2122 | "of size %wu", |
6d3bab5d | 2123 | "writing %wu bytes into a region " |
f7d86b5c | 2124 | "of size %wu", |
6d3bab5d | 2125 | lenrng[0].to_uhwi (), |
f7d86b5c MS |
2126 | spcrng[0].to_uhwi ())); |
2127 | else | |
2128 | warned = (writefn | |
2129 | ? warning_n (loc, OPT_Wstringop_overflow_, | |
2130 | lenrng[0].to_uhwi (), | |
6d3bab5d | 2131 | "%qD writing %wu byte into a region " |
f7d86b5c | 2132 | "of size between %wu and %wu", |
6d3bab5d | 2133 | "%qD writing %wu bytes into a region " |
f7d86b5c | 2134 | "of size between %wu and %wu", |
6d3bab5d | 2135 | writefn, lenrng[0].to_uhwi (), |
f7d86b5c MS |
2136 | spcrng[0].to_uhwi (), spcrng[1].to_uhwi ()) |
2137 | : warning_n (loc, OPT_Wstringop_overflow_, | |
2138 | lenrng[0].to_uhwi (), | |
6d3bab5d | 2139 | "writing %wu byte into a region " |
f7d86b5c | 2140 | "of size between %wu and %wu", |
6d3bab5d | 2141 | "writing %wu bytes into a region " |
f7d86b5c | 2142 | "of size between %wu and %wu", |
6d3bab5d | 2143 | lenrng[0].to_uhwi (), |
f7d86b5c MS |
2144 | spcrng[0].to_uhwi (), spcrng[1].to_uhwi ())); |
2145 | } | |
2146 | else if (spcrng[0] == spcrng[1]) | |
2147 | warned = (writefn | |
2148 | ? warning_at (loc, OPT_Wstringop_overflow_, | |
6d3bab5d | 2149 | "%qD writing between %wu and %wu bytes " |
f7d86b5c | 2150 | "into a region of size %wu", |
6d3bab5d | 2151 | writefn, lenrng[0].to_uhwi (), |
f7d86b5c MS |
2152 | lenrng[1].to_uhwi (), |
2153 | spcrng[0].to_uhwi ()) | |
2154 | : warning_at (loc, OPT_Wstringop_overflow_, | |
6d3bab5d | 2155 | "writing between %wu and %wu bytes " |
f7d86b5c | 2156 | "into a region of size %wu", |
6d3bab5d | 2157 | lenrng[0].to_uhwi (), |
f7d86b5c MS |
2158 | lenrng[1].to_uhwi (), |
2159 | spcrng[0].to_uhwi ())); | |
2160 | else | |
2161 | warned = (writefn | |
2162 | ? warning_at (loc, OPT_Wstringop_overflow_, | |
6d3bab5d | 2163 | "%qD writing between %wu and %wu bytes " |
f7d86b5c | 2164 | "into a region of size between %wu and %wu", |
6d3bab5d | 2165 | writefn, lenrng[0].to_uhwi (), |
f7d86b5c MS |
2166 | lenrng[1].to_uhwi (), |
2167 | spcrng[0].to_uhwi (), spcrng[1].to_uhwi ()) | |
2168 | : warning_at (loc, OPT_Wstringop_overflow_, | |
6d3bab5d | 2169 | "writing between %wu and %wu bytes " |
f7d86b5c | 2170 | "into a region of size between %wu and %wu", |
6d3bab5d | 2171 | lenrng[0].to_uhwi (), |
f7d86b5c MS |
2172 | lenrng[1].to_uhwi (), |
2173 | spcrng[0].to_uhwi (), spcrng[1].to_uhwi ())); | |
2174 | ||
2175 | if (!warned) | |
2176 | return; | |
2177 | ||
e9e2bad7 | 2178 | suppress_warning (stmt, OPT_Wstringop_overflow_); |
ef29b12c | 2179 | |
eafe8ee7 | 2180 | aref.inform_access (access_write_only); |
f7d86b5c MS |
2181 | } |
2182 | ||
2183 | /* Convenience wrapper for the above. */ | |
2184 | ||
47e4ab65 AH |
2185 | void |
2186 | strlen_pass::maybe_warn_overflow (gimple *stmt, bool call_lhs, | |
2187 | unsigned HOST_WIDE_INT len, | |
2188 | strinfo *si, bool plus_one, bool rawmem) | |
f7d86b5c | 2189 | { |
f0500db3 | 2190 | tree tlen = build_int_cst (size_type_node, len); |
47e4ab65 | 2191 | maybe_warn_overflow (stmt, call_lhs, tlen, si, plus_one, rawmem); |
f7d86b5c MS |
2192 | } |
2193 | ||
8b57bfeb JJ |
2194 | /* Handle a strlen call. If strlen of the argument is known, replace |
2195 | the strlen call with the known value, otherwise remember that strlen | |
2196 | of the argument is stored in the lhs SSA_NAME. */ | |
2197 | ||
47e4ab65 AH |
2198 | void |
2199 | strlen_pass::handle_builtin_strlen () | |
8b57bfeb | 2200 | { |
47e4ab65 | 2201 | gimple *stmt = gsi_stmt (m_gsi); |
8b57bfeb JJ |
2202 | tree lhs = gimple_call_lhs (stmt); |
2203 | ||
2204 | if (lhs == NULL_TREE) | |
2205 | return; | |
2206 | ||
781ff3d8 MS |
2207 | location_t loc = gimple_location (stmt); |
2208 | tree callee = gimple_call_fndecl (stmt); | |
2209 | tree src = gimple_call_arg (stmt, 0); | |
2210 | tree bound = (DECL_FUNCTION_CODE (callee) == BUILT_IN_STRNLEN | |
2211 | ? gimple_call_arg (stmt, 1) : NULL_TREE); | |
6b8b9596 | 2212 | int idx = get_stridx (src, stmt); |
9bc83f27 | 2213 | if (idx || (bound && integer_zerop (bound))) |
8b57bfeb | 2214 | { |
526ceb68 | 2215 | strinfo *si = NULL; |
8b57bfeb JJ |
2216 | tree rhs; |
2217 | ||
2218 | if (idx < 0) | |
2219 | rhs = build_int_cst (TREE_TYPE (lhs), ~idx); | |
9bc83f27 JJ |
2220 | else if (idx == 0) |
2221 | rhs = bound; | |
8b57bfeb JJ |
2222 | else |
2223 | { | |
2224 | rhs = NULL_TREE; | |
2225 | si = get_strinfo (idx); | |
2226 | if (si != NULL) | |
9bc83f27 JJ |
2227 | { |
2228 | rhs = get_string_length (si); | |
2229 | /* For strnlen, if bound is constant, even if si is not known | |
2230 | to be zero terminated, if we know at least bound bytes are | |
2231 | not zero, the return value will be bound. */ | |
2232 | if (rhs == NULL_TREE | |
2233 | && bound != NULL_TREE | |
2234 | && TREE_CODE (bound) == INTEGER_CST | |
2235 | && si->nonzero_chars != NULL_TREE | |
2236 | && TREE_CODE (si->nonzero_chars) == INTEGER_CST | |
2237 | && tree_int_cst_le (bound, si->nonzero_chars)) | |
2238 | rhs = bound; | |
2239 | } | |
8b57bfeb JJ |
2240 | } |
2241 | if (rhs != NULL_TREE) | |
2242 | { | |
2243 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
2244 | { | |
2245 | fprintf (dump_file, "Optimizing: "); | |
2246 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
2247 | } | |
2248 | rhs = unshare_expr (rhs); | |
2249 | if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (rhs))) | |
781ff3d8 | 2250 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); |
b36bc89e | 2251 | |
781ff3d8 | 2252 | if (bound) |
9bc83f27 | 2253 | rhs = fold_build2_loc (loc, MIN_EXPR, TREE_TYPE (rhs), rhs, bound); |
b36bc89e | 2254 | |
47e4ab65 AH |
2255 | gimplify_and_update_call_from_tree (&m_gsi, rhs); |
2256 | stmt = gsi_stmt (m_gsi); | |
8b57bfeb JJ |
2257 | update_stmt (stmt); |
2258 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
2259 | { | |
2260 | fprintf (dump_file, "into: "); | |
2261 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
2262 | } | |
b36bc89e | 2263 | |
8b57bfeb | 2264 | if (si != NULL |
9bc83f27 JJ |
2265 | /* Don't update anything for strnlen. */ |
2266 | && bound == NULL_TREE | |
e3f9a279 RS |
2267 | && TREE_CODE (si->nonzero_chars) != SSA_NAME |
2268 | && TREE_CODE (si->nonzero_chars) != INTEGER_CST | |
8b57bfeb JJ |
2269 | && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) |
2270 | { | |
2271 | si = unshare_strinfo (si); | |
e3f9a279 RS |
2272 | si->nonzero_chars = lhs; |
2273 | gcc_assert (si->full_string_p); | |
8b57bfeb | 2274 | } |
025d57f0 | 2275 | |
9bc83f27 JJ |
2276 | if (strlen_to_stridx |
2277 | && (bound == NULL_TREE | |
2278 | /* For strnlen record this only if the call is proven | |
2279 | to return the same value as strlen would. */ | |
2280 | || (TREE_CODE (bound) == INTEGER_CST | |
2281 | && TREE_CODE (rhs) == INTEGER_CST | |
2282 | && tree_int_cst_lt (rhs, bound)))) | |
781ff3d8 MS |
2283 | strlen_to_stridx->put (lhs, stridx_strlenloc (idx, loc)); |
2284 | ||
8b57bfeb JJ |
2285 | return; |
2286 | } | |
2287 | } | |
2288 | if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) | |
2289 | return; | |
b36bc89e | 2290 | |
8b57bfeb JJ |
2291 | if (idx == 0) |
2292 | idx = new_stridx (src); | |
e3f9a279 RS |
2293 | else |
2294 | { | |
2295 | strinfo *si = get_strinfo (idx); | |
2296 | if (si != NULL) | |
2297 | { | |
2298 | if (!si->full_string_p && !si->stmt) | |
2299 | { | |
2300 | /* Until now we only had a lower bound on the string length. | |
2301 | Install LHS as the actual length. */ | |
2302 | si = unshare_strinfo (si); | |
1aad7106 | 2303 | tree old = si->nonzero_chars; |
e3f9a279 RS |
2304 | si->nonzero_chars = lhs; |
2305 | si->full_string_p = true; | |
ef29b12c | 2306 | if (old && TREE_CODE (old) == INTEGER_CST) |
1aad7106 | 2307 | { |
1aad7106 RS |
2308 | old = fold_convert_loc (loc, TREE_TYPE (lhs), old); |
2309 | tree adj = fold_build2_loc (loc, MINUS_EXPR, | |
2310 | TREE_TYPE (lhs), lhs, old); | |
2311 | adjust_related_strinfos (loc, si, adj); | |
dfea3d6f | 2312 | /* Use the constant minimum length as the lower bound |
34fcf41e MS |
2313 | of the non-constant length. */ |
2314 | wide_int min = wi::to_wide (old); | |
2315 | wide_int max | |
2316 | = wi::to_wide (TYPE_MAX_VALUE (ptrdiff_type_node)) - 2; | |
2317 | set_strlen_range (lhs, min, max); | |
1aad7106 RS |
2318 | } |
2319 | else | |
2320 | { | |
2321 | si->first = 0; | |
2322 | si->prev = 0; | |
2323 | si->next = 0; | |
2324 | } | |
e3f9a279 RS |
2325 | } |
2326 | return; | |
2327 | } | |
2328 | } | |
8b57bfeb JJ |
2329 | if (idx) |
2330 | { | |
b36bc89e MS |
2331 | if (!bound) |
2332 | { | |
2333 | /* Only store the new length information for calls to strlen(), | |
2334 | not for those to strnlen(). */ | |
2335 | strinfo *si = new_strinfo (src, idx, lhs, true); | |
2336 | set_strinfo (idx, si); | |
2337 | find_equal_ptrs (src, idx); | |
2338 | } | |
025d57f0 | 2339 | |
06199618 | 2340 | /* For SRC that is an array of N elements, set LHS's range |
781ff3d8 MS |
2341 | to [0, min (N, BOUND)]. A constant return value means |
2342 | the range would have consisted of a single value. In | |
2343 | that case, fold the result into the returned constant. */ | |
2344 | if (tree ret = maybe_set_strlen_range (lhs, src, bound)) | |
2345 | if (TREE_CODE (ret) == INTEGER_CST) | |
2346 | { | |
2347 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
2348 | { | |
2349 | fprintf (dump_file, "Optimizing: "); | |
2350 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
2351 | } | |
2352 | if (!useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (ret))) | |
2353 | ret = fold_convert_loc (loc, TREE_TYPE (lhs), ret); | |
47e4ab65 AH |
2354 | gimplify_and_update_call_from_tree (&m_gsi, ret); |
2355 | stmt = gsi_stmt (m_gsi); | |
781ff3d8 MS |
2356 | update_stmt (stmt); |
2357 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
2358 | { | |
2359 | fprintf (dump_file, "into: "); | |
2360 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
2361 | } | |
2362 | } | |
06199618 | 2363 | |
b36bc89e | 2364 | if (strlen_to_stridx && !bound) |
781ff3d8 | 2365 | strlen_to_stridx->put (lhs, stridx_strlenloc (idx, loc)); |
8b57bfeb JJ |
2366 | } |
2367 | } | |
2368 | ||
2369 | /* Handle a strchr call. If strlen of the first argument is known, replace | |
2370 | the strchr (x, 0) call with the endptr or x + strlen, otherwise remember | |
2371 | that lhs of the call is endptr and strlen of the argument is endptr - x. */ | |
2372 | ||
47e4ab65 AH |
2373 | void |
2374 | strlen_pass::handle_builtin_strchr () | |
8b57bfeb | 2375 | { |
47e4ab65 | 2376 | gimple *stmt = gsi_stmt (m_gsi); |
8b57bfeb JJ |
2377 | tree lhs = gimple_call_lhs (stmt); |
2378 | ||
2379 | if (lhs == NULL_TREE) | |
2380 | return; | |
2381 | ||
31db0fe0 | 2382 | if (!integer_zerop (gimple_call_arg (stmt, 1))) |
8b57bfeb JJ |
2383 | return; |
2384 | ||
b5338fb3 MS |
2385 | tree src = gimple_call_arg (stmt, 0); |
2386 | ||
2387 | /* Avoid folding if the first argument is not a nul-terminated array. | |
2388 | Defer warning until later. */ | |
2389 | if (!check_nul_terminated_array (NULL_TREE, src)) | |
2390 | return; | |
2391 | ||
6b8b9596 | 2392 | int idx = get_stridx (src, stmt); |
8b57bfeb JJ |
2393 | if (idx) |
2394 | { | |
526ceb68 | 2395 | strinfo *si = NULL; |
8b57bfeb JJ |
2396 | tree rhs; |
2397 | ||
2398 | if (idx < 0) | |
2399 | rhs = build_int_cst (size_type_node, ~idx); | |
2400 | else | |
2401 | { | |
2402 | rhs = NULL_TREE; | |
2403 | si = get_strinfo (idx); | |
2404 | if (si != NULL) | |
2405 | rhs = get_string_length (si); | |
2406 | } | |
2407 | if (rhs != NULL_TREE) | |
2408 | { | |
2409 | location_t loc = gimple_location (stmt); | |
2410 | ||
2411 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
2412 | { | |
2413 | fprintf (dump_file, "Optimizing: "); | |
2414 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
2415 | } | |
2416 | if (si != NULL && si->endptr != NULL_TREE) | |
2417 | { | |
2418 | rhs = unshare_expr (si->endptr); | |
2419 | if (!useless_type_conversion_p (TREE_TYPE (lhs), | |
2420 | TREE_TYPE (rhs))) | |
2421 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); | |
2422 | } | |
2423 | else | |
2424 | { | |
2425 | rhs = fold_convert_loc (loc, sizetype, unshare_expr (rhs)); | |
2426 | rhs = fold_build2_loc (loc, POINTER_PLUS_EXPR, | |
2427 | TREE_TYPE (src), src, rhs); | |
2428 | if (!useless_type_conversion_p (TREE_TYPE (lhs), | |
2429 | TREE_TYPE (rhs))) | |
2430 | rhs = fold_convert_loc (loc, TREE_TYPE (lhs), rhs); | |
2431 | } | |
47e4ab65 AH |
2432 | gimplify_and_update_call_from_tree (&m_gsi, rhs); |
2433 | stmt = gsi_stmt (m_gsi); | |
8b57bfeb JJ |
2434 | update_stmt (stmt); |
2435 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
2436 | { | |
2437 | fprintf (dump_file, "into: "); | |
2438 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
2439 | } | |
2440 | if (si != NULL | |
2441 | && si->endptr == NULL_TREE | |
2442 | && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) | |
2443 | { | |
2444 | si = unshare_strinfo (si); | |
2445 | si->endptr = lhs; | |
2446 | } | |
2447 | zero_length_string (lhs, si); | |
2448 | return; | |
2449 | } | |
2450 | } | |
2451 | if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) | |
2452 | return; | |
2453 | if (TREE_CODE (src) != SSA_NAME || !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (src)) | |
2454 | { | |
2455 | if (idx == 0) | |
2456 | idx = new_stridx (src); | |
2457 | else if (get_strinfo (idx) != NULL) | |
2458 | { | |
2459 | zero_length_string (lhs, NULL); | |
2460 | return; | |
2461 | } | |
2462 | if (idx) | |
2463 | { | |
2464 | location_t loc = gimple_location (stmt); | |
2465 | tree lhsu = fold_convert_loc (loc, size_type_node, lhs); | |
2466 | tree srcu = fold_convert_loc (loc, size_type_node, src); | |
2467 | tree length = fold_build2_loc (loc, MINUS_EXPR, | |
2468 | size_type_node, lhsu, srcu); | |
e3f9a279 | 2469 | strinfo *si = new_strinfo (src, idx, length, true); |
8b57bfeb JJ |
2470 | si->endptr = lhs; |
2471 | set_strinfo (idx, si); | |
2472 | find_equal_ptrs (src, idx); | |
2473 | zero_length_string (lhs, si); | |
2474 | } | |
2475 | } | |
2476 | else | |
2477 | zero_length_string (lhs, NULL); | |
2478 | } | |
2479 | ||
2480 | /* Handle a strcpy-like ({st{r,p}cpy,__st{r,p}cpy_chk}) call. | |
2481 | If strlen of the second argument is known, strlen of the first argument | |
2482 | is the same after this call. Furthermore, attempt to convert it to | |
ef29b12c | 2483 | memcpy. Uses RVALS to determine range information. */ |
8b57bfeb | 2484 | |
47e4ab65 AH |
2485 | void |
2486 | strlen_pass::handle_builtin_strcpy (built_in_function bcode) | |
8b57bfeb JJ |
2487 | { |
2488 | int idx, didx; | |
cc8bea0a | 2489 | tree src, dst, srclen, len, lhs, type, fn, oldlen; |
8b57bfeb | 2490 | bool success; |
47e4ab65 | 2491 | gimple *stmt = gsi_stmt (m_gsi); |
526ceb68 | 2492 | strinfo *si, *dsi, *olddsi, *zsi; |
8b57bfeb JJ |
2493 | location_t loc; |
2494 | ||
31db0fe0 | 2495 | src = gimple_call_arg (stmt, 1); |
8b57bfeb JJ |
2496 | dst = gimple_call_arg (stmt, 0); |
2497 | lhs = gimple_call_lhs (stmt); | |
6b8b9596 | 2498 | idx = get_stridx (src, stmt); |
8b57bfeb JJ |
2499 | si = NULL; |
2500 | if (idx > 0) | |
2501 | si = get_strinfo (idx); | |
2502 | ||
6b8b9596 | 2503 | didx = get_stridx (dst, stmt); |
8b57bfeb JJ |
2504 | olddsi = NULL; |
2505 | oldlen = NULL_TREE; | |
2506 | if (didx > 0) | |
2507 | olddsi = get_strinfo (didx); | |
2508 | else if (didx < 0) | |
2509 | return; | |
2510 | ||
2511 | if (olddsi != NULL) | |
47e4ab65 | 2512 | adjust_last_stmt (olddsi, stmt, false); |
8b57bfeb JJ |
2513 | |
2514 | srclen = NULL_TREE; | |
2515 | if (si != NULL) | |
2516 | srclen = get_string_length (si); | |
2517 | else if (idx < 0) | |
2518 | srclen = build_int_cst (size_type_node, ~idx); | |
2519 | ||
47e4ab65 | 2520 | maybe_warn_overflow (stmt, false, srclen, olddsi, true); |
ef29b12c MS |
2521 | |
2522 | if (olddsi != NULL) | |
47e4ab65 | 2523 | adjust_last_stmt (olddsi, stmt, false); |
ef29b12c | 2524 | |
8b57bfeb JJ |
2525 | loc = gimple_location (stmt); |
2526 | if (srclen == NULL_TREE) | |
2527 | switch (bcode) | |
2528 | { | |
2529 | case BUILT_IN_STRCPY: | |
2530 | case BUILT_IN_STRCPY_CHK: | |
e79983f4 | 2531 | if (lhs != NULL_TREE || !builtin_decl_implicit_p (BUILT_IN_STPCPY)) |
8b57bfeb JJ |
2532 | return; |
2533 | break; | |
2534 | case BUILT_IN_STPCPY: | |
2535 | case BUILT_IN_STPCPY_CHK: | |
2536 | if (lhs == NULL_TREE) | |
2537 | return; | |
2538 | else | |
2539 | { | |
2540 | tree lhsuint = fold_convert_loc (loc, size_type_node, lhs); | |
2541 | srclen = fold_convert_loc (loc, size_type_node, dst); | |
2542 | srclen = fold_build2_loc (loc, MINUS_EXPR, size_type_node, | |
2543 | lhsuint, srclen); | |
2544 | } | |
2545 | break; | |
2546 | default: | |
2547 | gcc_unreachable (); | |
2548 | } | |
2549 | ||
2550 | if (didx == 0) | |
2551 | { | |
2552 | didx = new_stridx (dst); | |
2553 | if (didx == 0) | |
2554 | return; | |
2555 | } | |
2556 | if (olddsi != NULL) | |
2557 | { | |
e3f9a279 | 2558 | oldlen = olddsi->nonzero_chars; |
8b57bfeb | 2559 | dsi = unshare_strinfo (olddsi); |
e3f9a279 RS |
2560 | dsi->nonzero_chars = srclen; |
2561 | dsi->full_string_p = (srclen != NULL_TREE); | |
8b57bfeb JJ |
2562 | /* Break the chain, so adjust_related_strinfo on later pointers in |
2563 | the chain won't adjust this one anymore. */ | |
2564 | dsi->next = 0; | |
2565 | dsi->stmt = NULL; | |
2566 | dsi->endptr = NULL_TREE; | |
2567 | } | |
2568 | else | |
2569 | { | |
e3f9a279 | 2570 | dsi = new_strinfo (dst, didx, srclen, srclen != NULL_TREE); |
8b57bfeb JJ |
2571 | set_strinfo (didx, dsi); |
2572 | find_equal_ptrs (dst, didx); | |
2573 | } | |
2574 | dsi->writable = true; | |
2575 | dsi->dont_invalidate = true; | |
2576 | ||
e3f9a279 | 2577 | if (dsi->nonzero_chars == NULL_TREE) |
8b57bfeb | 2578 | { |
526ceb68 | 2579 | strinfo *chainsi; |
93a90db6 | 2580 | |
8b57bfeb | 2581 | /* If string length of src is unknown, use delayed length |
dfea3d6f | 2582 | computation. If string length of dst will be needed, it |
8b57bfeb JJ |
2583 | can be computed by transforming this strcpy call into |
2584 | stpcpy and subtracting dst from the return value. */ | |
93a90db6 AK |
2585 | |
2586 | /* Look for earlier strings whose length could be determined if | |
2587 | this strcpy is turned into an stpcpy. */ | |
2588 | ||
2589 | if (dsi->prev != 0 && (chainsi = verify_related_strinfos (dsi)) != NULL) | |
2590 | { | |
2591 | for (; chainsi && chainsi != dsi; chainsi = get_strinfo (chainsi->next)) | |
2592 | { | |
2593 | /* When setting a stmt for delayed length computation | |
2594 | prevent all strinfos through dsi from being | |
2595 | invalidated. */ | |
2596 | chainsi = unshare_strinfo (chainsi); | |
2597 | chainsi->stmt = stmt; | |
e3f9a279 RS |
2598 | chainsi->nonzero_chars = NULL_TREE; |
2599 | chainsi->full_string_p = false; | |
93a90db6 AK |
2600 | chainsi->endptr = NULL_TREE; |
2601 | chainsi->dont_invalidate = true; | |
2602 | } | |
2603 | } | |
8b57bfeb | 2604 | dsi->stmt = stmt; |
cc8bea0a MS |
2605 | |
2606 | /* Try to detect overlap before returning. This catches cases | |
2607 | like strcpy (d, d + n) where n is non-constant whose range | |
2608 | is such that (n <= strlen (d) holds). | |
2609 | ||
2610 | OLDDSI->NONZERO_chars may have been reset by this point with | |
2611 | oldlen holding it original value. */ | |
2612 | if (olddsi && oldlen) | |
2613 | { | |
2614 | /* Add 1 for the terminating NUL. */ | |
2615 | tree type = TREE_TYPE (oldlen); | |
2616 | oldlen = fold_build2 (PLUS_EXPR, type, oldlen, | |
2617 | build_int_cst (type, 1)); | |
8a45b051 | 2618 | check_bounds_or_overlap (stmt, olddsi->ptr, src, oldlen, NULL_TREE); |
cc8bea0a MS |
2619 | } |
2620 | ||
8b57bfeb JJ |
2621 | return; |
2622 | } | |
2623 | ||
2624 | if (olddsi != NULL) | |
2625 | { | |
2626 | tree adj = NULL_TREE; | |
2627 | if (oldlen == NULL_TREE) | |
2628 | ; | |
2629 | else if (integer_zerop (oldlen)) | |
2630 | adj = srclen; | |
2631 | else if (TREE_CODE (oldlen) == INTEGER_CST | |
2632 | || TREE_CODE (srclen) == INTEGER_CST) | |
2633 | adj = fold_build2_loc (loc, MINUS_EXPR, | |
2634 | TREE_TYPE (srclen), srclen, | |
2635 | fold_convert_loc (loc, TREE_TYPE (srclen), | |
2636 | oldlen)); | |
2637 | if (adj != NULL_TREE) | |
2638 | adjust_related_strinfos (loc, dsi, adj); | |
2639 | else | |
2640 | dsi->prev = 0; | |
2641 | } | |
2642 | /* strcpy src may not overlap dst, so src doesn't need to be | |
2643 | invalidated either. */ | |
2644 | if (si != NULL) | |
2645 | si->dont_invalidate = true; | |
2646 | ||
2647 | fn = NULL_TREE; | |
2648 | zsi = NULL; | |
2649 | switch (bcode) | |
2650 | { | |
2651 | case BUILT_IN_STRCPY: | |
e79983f4 | 2652 | fn = builtin_decl_implicit (BUILT_IN_MEMCPY); |
8b57bfeb | 2653 | if (lhs) |
9771b263 | 2654 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] = didx; |
8b57bfeb JJ |
2655 | break; |
2656 | case BUILT_IN_STRCPY_CHK: | |
e79983f4 | 2657 | fn = builtin_decl_explicit (BUILT_IN_MEMCPY_CHK); |
8b57bfeb | 2658 | if (lhs) |
9771b263 | 2659 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] = didx; |
8b57bfeb JJ |
2660 | break; |
2661 | case BUILT_IN_STPCPY: | |
2662 | /* This would need adjustment of the lhs (subtract one), | |
2663 | or detection that the trailing '\0' doesn't need to be | |
2664 | written, if it will be immediately overwritten. | |
e79983f4 | 2665 | fn = builtin_decl_explicit (BUILT_IN_MEMPCPY); */ |
8b57bfeb JJ |
2666 | if (lhs) |
2667 | { | |
2668 | dsi->endptr = lhs; | |
2669 | zsi = zero_length_string (lhs, dsi); | |
2670 | } | |
2671 | break; | |
2672 | case BUILT_IN_STPCPY_CHK: | |
2673 | /* This would need adjustment of the lhs (subtract one), | |
2674 | or detection that the trailing '\0' doesn't need to be | |
2675 | written, if it will be immediately overwritten. | |
e79983f4 | 2676 | fn = builtin_decl_explicit (BUILT_IN_MEMPCPY_CHK); */ |
8b57bfeb JJ |
2677 | if (lhs) |
2678 | { | |
2679 | dsi->endptr = lhs; | |
2680 | zsi = zero_length_string (lhs, dsi); | |
2681 | } | |
2682 | break; | |
2683 | default: | |
2684 | gcc_unreachable (); | |
2685 | } | |
2686 | if (zsi != NULL) | |
2687 | zsi->dont_invalidate = true; | |
2688 | ||
cc8bea0a MS |
2689 | if (fn) |
2690 | { | |
2691 | tree args = TYPE_ARG_TYPES (TREE_TYPE (fn)); | |
2692 | type = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (args))); | |
2693 | } | |
2694 | else | |
2695 | type = size_type_node; | |
8b57bfeb JJ |
2696 | |
2697 | len = fold_convert_loc (loc, type, unshare_expr (srclen)); | |
2698 | len = fold_build2_loc (loc, PLUS_EXPR, type, len, build_int_cst (type, 1)); | |
cc8bea0a | 2699 | |
e9e2bad7 MS |
2700 | /* Disable warning for the transformed statement? */ |
2701 | opt_code no_warning_opt = no_warning; | |
cc8bea0a | 2702 | |
e9e2bad7 MS |
2703 | if (const strinfo *chksi = si ? olddsi ? olddsi : dsi : NULL) |
2704 | { | |
2705 | no_warning_opt = check_bounds_or_overlap (stmt, chksi->ptr, si->ptr, | |
2706 | NULL_TREE, len); | |
2707 | if (no_warning_opt) | |
2708 | suppress_warning (stmt, no_warning_opt); | |
2709 | } | |
cc8bea0a MS |
2710 | |
2711 | if (fn == NULL_TREE) | |
2712 | return; | |
2713 | ||
47e4ab65 | 2714 | len = force_gimple_operand_gsi (&m_gsi, len, true, NULL_TREE, true, |
8b57bfeb JJ |
2715 | GSI_SAME_STMT); |
2716 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
2717 | { | |
2718 | fprintf (dump_file, "Optimizing: "); | |
2719 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
2720 | } | |
31db0fe0 | 2721 | if (gimple_call_num_args (stmt) == 2) |
47e4ab65 | 2722 | success = update_gimple_call (&m_gsi, fn, 3, dst, src, len); |
8b57bfeb | 2723 | else |
47e4ab65 | 2724 | success = update_gimple_call (&m_gsi, fn, 4, dst, src, len, |
31db0fe0 | 2725 | gimple_call_arg (stmt, 2)); |
8b57bfeb JJ |
2726 | if (success) |
2727 | { | |
47e4ab65 | 2728 | stmt = gsi_stmt (m_gsi); |
8b57bfeb JJ |
2729 | update_stmt (stmt); |
2730 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
2731 | { | |
2732 | fprintf (dump_file, "into: "); | |
2733 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
2734 | } | |
2735 | /* Allow adjust_last_stmt to decrease this memcpy's size. */ | |
2736 | laststmt.stmt = stmt; | |
2737 | laststmt.len = srclen; | |
2738 | laststmt.stridx = dsi->idx; | |
2739 | } | |
2740 | else if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
2741 | fprintf (dump_file, "not possible.\n"); | |
cc8bea0a | 2742 | |
e9e2bad7 MS |
2743 | if (no_warning_opt) |
2744 | suppress_warning (stmt, no_warning_opt); | |
cc8bea0a MS |
2745 | } |
2746 | ||
2747 | /* Check the size argument to the built-in forms of stpncpy and strncpy | |
2748 | for out-of-bounds offsets or overlapping access, and to see if the | |
2749 | size argument is derived from a call to strlen() on the source argument, | |
2750 | and if so, issue an appropriate warning. */ | |
2751 | ||
47e4ab65 AH |
2752 | void |
2753 | strlen_pass::handle_builtin_strncat (built_in_function) | |
cc8bea0a MS |
2754 | { |
2755 | /* Same as stxncpy(). */ | |
47e4ab65 | 2756 | handle_builtin_stxncpy_strncat (true); |
8b57bfeb JJ |
2757 | } |
2758 | ||
025d57f0 MS |
2759 | /* Return true if LEN depends on a call to strlen(SRC) in an interesting |
2760 | way. LEN can either be an integer expression, or a pointer (to char). | |
d5029d45 | 2761 | When it is the latter (such as in recursive calls to self) it is |
025d57f0 MS |
2762 | assumed to be the argument in some call to strlen() whose relationship |
2763 | to SRC is being ascertained. */ | |
2764 | ||
4252ccd7 | 2765 | bool |
025d57f0 MS |
2766 | is_strlen_related_p (tree src, tree len) |
2767 | { | |
2768 | if (TREE_CODE (TREE_TYPE (len)) == POINTER_TYPE | |
2769 | && operand_equal_p (src, len, 0)) | |
2770 | return true; | |
2771 | ||
2772 | if (TREE_CODE (len) != SSA_NAME) | |
2773 | return false; | |
2774 | ||
ef29b12c MS |
2775 | if (TREE_CODE (src) == SSA_NAME) |
2776 | { | |
2777 | gimple *srcdef = SSA_NAME_DEF_STMT (src); | |
2778 | if (is_gimple_assign (srcdef)) | |
2779 | { | |
2780 | /* Handle bitwise AND used in conversions from wider size_t | |
2781 | to narrower unsigned types. */ | |
2782 | tree_code code = gimple_assign_rhs_code (srcdef); | |
2783 | if (code == BIT_AND_EXPR | |
2784 | || code == NOP_EXPR) | |
2785 | return is_strlen_related_p (gimple_assign_rhs1 (srcdef), len); | |
2786 | ||
2787 | return false; | |
2788 | } | |
2789 | ||
2790 | if (gimple_call_builtin_p (srcdef, BUILT_IN_NORMAL)) | |
2791 | { | |
2792 | /* If SRC is the result of a call to an allocation function | |
2793 | or strlen, use the function's argument instead. */ | |
2794 | tree func = gimple_call_fndecl (srcdef); | |
2795 | built_in_function code = DECL_FUNCTION_CODE (func); | |
2796 | if (code == BUILT_IN_ALLOCA | |
2797 | || code == BUILT_IN_ALLOCA_WITH_ALIGN | |
2798 | || code == BUILT_IN_MALLOC | |
2799 | || code == BUILT_IN_STRLEN) | |
2800 | return is_strlen_related_p (gimple_call_arg (srcdef, 0), len); | |
2801 | ||
2802 | /* FIXME: Handle other functions with attribute alloc_size. */ | |
2803 | return false; | |
2804 | } | |
2805 | } | |
2806 | ||
2807 | gimple *lendef = SSA_NAME_DEF_STMT (len); | |
2808 | if (!lendef) | |
025d57f0 MS |
2809 | return false; |
2810 | ||
ef29b12c | 2811 | if (is_gimple_call (lendef)) |
025d57f0 | 2812 | { |
ef29b12c MS |
2813 | tree func = gimple_call_fndecl (lendef); |
2814 | if (!valid_builtin_call (lendef) | |
025d57f0 MS |
2815 | || DECL_FUNCTION_CODE (func) != BUILT_IN_STRLEN) |
2816 | return false; | |
2817 | ||
ef29b12c | 2818 | tree arg = gimple_call_arg (lendef, 0); |
025d57f0 MS |
2819 | return is_strlen_related_p (src, arg); |
2820 | } | |
2821 | ||
ef29b12c | 2822 | if (!is_gimple_assign (lendef)) |
025d57f0 MS |
2823 | return false; |
2824 | ||
ef29b12c MS |
2825 | tree_code code = gimple_assign_rhs_code (lendef); |
2826 | tree rhs1 = gimple_assign_rhs1 (lendef); | |
025d57f0 MS |
2827 | tree rhstype = TREE_TYPE (rhs1); |
2828 | ||
2829 | if ((TREE_CODE (rhstype) == POINTER_TYPE && code == POINTER_PLUS_EXPR) | |
2830 | || (INTEGRAL_TYPE_P (rhstype) | |
2831 | && (code == BIT_AND_EXPR | |
2832 | || code == NOP_EXPR))) | |
2833 | { | |
4252ccd7 MS |
2834 | /* Pointer plus (an integer), and truncation are considered among |
2835 | the (potentially) related expressions to strlen. */ | |
025d57f0 MS |
2836 | return is_strlen_related_p (src, rhs1); |
2837 | } | |
2838 | ||
ef29b12c | 2839 | if (tree rhs2 = gimple_assign_rhs2 (lendef)) |
4252ccd7 MS |
2840 | { |
2841 | /* Integer subtraction is considered strlen-related when both | |
2842 | arguments are integers and second one is strlen-related. */ | |
2843 | rhstype = TREE_TYPE (rhs2); | |
2844 | if (INTEGRAL_TYPE_P (rhstype) && code == MINUS_EXPR) | |
2845 | return is_strlen_related_p (src, rhs2); | |
2846 | } | |
2847 | ||
025d57f0 MS |
2848 | return false; |
2849 | } | |
2850 | ||
0a0de963 MS |
2851 | /* Called by handle_builtin_stxncpy_strncat and by |
2852 | gimple_fold_builtin_strncpy in gimple-fold.c. | |
5d0d5d68 MS |
2853 | Check to see if the specified bound is a) equal to the size of |
2854 | the destination DST and if so, b) if it's immediately followed by | |
2855 | DST[CNT - 1] = '\0'. If a) holds and b) does not, warn. Otherwise, | |
2856 | do nothing. Return true if diagnostic has been issued. | |
025d57f0 MS |
2857 | |
2858 | The purpose is to diagnose calls to strncpy and stpncpy that do | |
2859 | not nul-terminate the copy while allowing for the idiom where | |
2860 | such a call is immediately followed by setting the last element | |
2861 | to nul, as in: | |
2862 | char a[32]; | |
2863 | strncpy (a, s, sizeof a); | |
2864 | a[sizeof a - 1] = '\0'; | |
2865 | */ | |
2866 | ||
5d0d5d68 | 2867 | bool |
d02c41dd MS |
2868 | maybe_diag_stxncpy_trunc (gimple_stmt_iterator gsi, tree src, tree cnt, |
2869 | pointer_query *ptr_qry /* = NULL */) | |
025d57f0 | 2870 | { |
025d57f0 | 2871 | gimple *stmt = gsi_stmt (gsi); |
e9e2bad7 | 2872 | if (warning_suppressed_p (stmt, OPT_Wstringop_truncation)) |
e9b9fa4c | 2873 | return false; |
025d57f0 MS |
2874 | |
2875 | wide_int cntrange[2]; | |
45f4e2b0 AH |
2876 | value_range r; |
2877 | if (!get_range_query (cfun)->range_of_expr (r, cnt) | |
2878 | || r.varying_p () | |
2879 | || r.undefined_p ()) | |
2880 | return false; | |
025d57f0 | 2881 | |
45f4e2b0 AH |
2882 | cntrange[0] = wi::to_wide (r.min ()); |
2883 | cntrange[1] = wi::to_wide (r.max ()); | |
2884 | if (r.kind () == VR_ANTI_RANGE) | |
025d57f0 | 2885 | { |
83325a9d | 2886 | wide_int maxobjsize = wi::to_wide (TYPE_MAX_VALUE (ptrdiff_type_node)); |
025d57f0 | 2887 | |
83325a9d JJ |
2888 | if (wi::ltu_p (cntrange[1], maxobjsize)) |
2889 | { | |
2890 | cntrange[0] = cntrange[1] + 1; | |
2891 | cntrange[1] = maxobjsize; | |
025d57f0 MS |
2892 | } |
2893 | else | |
83325a9d JJ |
2894 | { |
2895 | cntrange[1] = cntrange[0] - 1; | |
2896 | cntrange[0] = wi::zero (TYPE_PRECISION (TREE_TYPE (cnt))); | |
2897 | } | |
025d57f0 | 2898 | } |
025d57f0 MS |
2899 | |
2900 | /* Negative value is the constant string length. If it's less than | |
5d0d5d68 MS |
2901 | the lower bound there is no truncation. Avoid calling get_stridx() |
2902 | when ssa_ver_to_stridx is empty. That implies the caller isn't | |
2903 | running under the control of this pass and ssa_ver_to_stridx hasn't | |
2904 | been created yet. */ | |
6b8b9596 | 2905 | int sidx = ssa_ver_to_stridx.length () ? get_stridx (src, stmt) : 0; |
025d57f0 MS |
2906 | if (sidx < 0 && wi::gtu_p (cntrange[0], ~sidx)) |
2907 | return false; | |
2908 | ||
2909 | tree dst = gimple_call_arg (stmt, 0); | |
025d57f0 MS |
2910 | tree dstdecl = dst; |
2911 | if (TREE_CODE (dstdecl) == ADDR_EXPR) | |
2912 | dstdecl = TREE_OPERAND (dstdecl, 0); | |
2913 | ||
6a33d0ff | 2914 | tree ref = NULL_TREE; |
4252ccd7 MS |
2915 | |
2916 | if (!sidx) | |
2917 | { | |
2918 | /* If the source is a non-string return early to avoid warning | |
2919 | for possible truncation (if the truncation is certain SIDX | |
2920 | is non-zero). */ | |
2921 | tree srcdecl = gimple_call_arg (stmt, 1); | |
2922 | if (TREE_CODE (srcdecl) == ADDR_EXPR) | |
2923 | srcdecl = TREE_OPERAND (srcdecl, 0); | |
2924 | if (get_attr_nonstring_decl (srcdecl, &ref)) | |
2925 | return false; | |
2926 | } | |
2927 | ||
53b28abf | 2928 | /* Likewise, if the destination refers to an array/pointer declared |
4252ccd7 | 2929 | nonstring return early. */ |
6a33d0ff MS |
2930 | if (get_attr_nonstring_decl (dstdecl, &ref)) |
2931 | return false; | |
025d57f0 MS |
2932 | |
2933 | /* Look for dst[i] = '\0'; after the stxncpy() call and if found | |
2934 | avoid the truncation warning. */ | |
b25e5572 | 2935 | gsi_next_nondebug (&gsi); |
025d57f0 | 2936 | gimple *next_stmt = gsi_stmt (gsi); |
a76acaed MS |
2937 | if (!next_stmt) |
2938 | { | |
2939 | /* When there is no statement in the same basic block check | |
2940 | the immediate successor block. */ | |
2941 | if (basic_block bb = gimple_bb (stmt)) | |
2942 | { | |
2943 | if (single_succ_p (bb)) | |
2944 | { | |
2945 | /* For simplicity, ignore blocks with multiple outgoing | |
2946 | edges for now and only consider successor blocks along | |
2947 | normal edges. */ | |
2948 | edge e = EDGE_SUCC (bb, 0); | |
2949 | if (!(e->flags & EDGE_ABNORMAL)) | |
2950 | { | |
2951 | gsi = gsi_start_bb (e->dest); | |
2952 | next_stmt = gsi_stmt (gsi); | |
2953 | if (next_stmt && is_gimple_debug (next_stmt)) | |
2954 | { | |
2955 | gsi_next_nondebug (&gsi); | |
2956 | next_stmt = gsi_stmt (gsi); | |
2957 | } | |
2958 | } | |
2959 | } | |
2960 | } | |
2961 | } | |
025d57f0 | 2962 | |
a76acaed | 2963 | if (next_stmt && is_gimple_assign (next_stmt)) |
025d57f0 | 2964 | { |
025d57f0 | 2965 | tree lhs = gimple_assign_lhs (next_stmt); |
6a33d0ff MS |
2966 | tree_code code = TREE_CODE (lhs); |
2967 | if (code == ARRAY_REF || code == MEM_REF) | |
2968 | lhs = TREE_OPERAND (lhs, 0); | |
2969 | ||
2970 | tree func = gimple_call_fndecl (stmt); | |
2971 | if (DECL_FUNCTION_CODE (func) == BUILT_IN_STPNCPY) | |
2972 | { | |
2973 | tree ret = gimple_call_lhs (stmt); | |
2974 | if (ret && operand_equal_p (ret, lhs, 0)) | |
2975 | return false; | |
2976 | } | |
2977 | ||
2978 | /* Determine the base address and offset of the reference, | |
2979 | ignoring the innermost array index. */ | |
2980 | if (TREE_CODE (ref) == ARRAY_REF) | |
2981 | ref = TREE_OPERAND (ref, 0); | |
2982 | ||
a90c8804 | 2983 | poly_int64 dstoff; |
6a33d0ff MS |
2984 | tree dstbase = get_addr_base_and_unit_offset (ref, &dstoff); |
2985 | ||
a90c8804 | 2986 | poly_int64 lhsoff; |
6a33d0ff MS |
2987 | tree lhsbase = get_addr_base_and_unit_offset (lhs, &lhsoff); |
2988 | if (lhsbase | |
44e60df3 | 2989 | && dstbase |
a90c8804 | 2990 | && known_eq (dstoff, lhsoff) |
6a33d0ff | 2991 | && operand_equal_p (dstbase, lhsbase, 0)) |
025d57f0 MS |
2992 | return false; |
2993 | } | |
2994 | ||
2995 | int prec = TYPE_PRECISION (TREE_TYPE (cnt)); | |
2996 | wide_int lenrange[2]; | |
2997 | if (strinfo *sisrc = sidx > 0 ? get_strinfo (sidx) : NULL) | |
2998 | { | |
2999 | lenrange[0] = (sisrc->nonzero_chars | |
3000 | && TREE_CODE (sisrc->nonzero_chars) == INTEGER_CST | |
3001 | ? wi::to_wide (sisrc->nonzero_chars) | |
3002 | : wi::zero (prec)); | |
3003 | lenrange[1] = lenrange[0]; | |
3004 | } | |
3005 | else if (sidx < 0) | |
3006 | lenrange[0] = lenrange[1] = wi::shwi (~sidx, prec); | |
3007 | else | |
3008 | { | |
5d6655eb | 3009 | c_strlen_data lendata = { }; |
a7160771 MS |
3010 | /* Set MAXBOUND to an arbitrary non-null non-integer node as a request |
3011 | to have it set to the length of the longest string in a PHI. */ | |
3012 | lendata.maxbound = src; | |
5d6655eb MS |
3013 | get_range_strlen (src, &lendata, /* eltsize = */1); |
3014 | if (TREE_CODE (lendata.minlen) == INTEGER_CST | |
3015 | && TREE_CODE (lendata.maxbound) == INTEGER_CST) | |
025d57f0 | 3016 | { |
5d6655eb MS |
3017 | /* When LENDATA.MAXLEN is unknown, reset LENDATA.MINLEN |
3018 | which stores the length of the shortest known string. */ | |
3019 | if (integer_all_onesp (lendata.maxlen)) | |
3020 | lenrange[0] = wi::shwi (0, prec); | |
3021 | else | |
3022 | lenrange[0] = wi::to_wide (lendata.minlen, prec); | |
3023 | lenrange[1] = wi::to_wide (lendata.maxbound, prec); | |
025d57f0 MS |
3024 | } |
3025 | else | |
3026 | { | |
3027 | lenrange[0] = wi::shwi (0, prec); | |
3028 | lenrange[1] = wi::shwi (-1, prec); | |
3029 | } | |
3030 | } | |
3031 | ||
55ace4d1 | 3032 | location_t callloc = gimple_or_expr_nonartificial_location (stmt, dst); |
025d57f0 MS |
3033 | tree func = gimple_call_fndecl (stmt); |
3034 | ||
3035 | if (lenrange[0] != 0 || !wi::neg_p (lenrange[1])) | |
3036 | { | |
3037 | /* If the longest source string is shorter than the lower bound | |
3038 | of the specified count the copy is definitely nul-terminated. */ | |
3039 | if (wi::ltu_p (lenrange[1], cntrange[0])) | |
3040 | return false; | |
3041 | ||
3042 | if (wi::neg_p (lenrange[1])) | |
3043 | { | |
3044 | /* The length of one of the strings is unknown but at least | |
3045 | one has non-zero length and that length is stored in | |
3046 | LENRANGE[1]. Swap the bounds to force a "may be truncated" | |
3047 | warning below. */ | |
3048 | lenrange[1] = lenrange[0]; | |
3049 | lenrange[0] = wi::shwi (0, prec); | |
3050 | } | |
3051 | ||
eec5f615 MS |
3052 | /* Set to true for strncat whose bound is derived from the length |
3053 | of the destination (the expected usage pattern). */ | |
3054 | bool cat_dstlen_bounded = false; | |
3055 | if (DECL_FUNCTION_CODE (func) == BUILT_IN_STRNCAT) | |
3056 | cat_dstlen_bounded = is_strlen_related_p (dst, cnt); | |
3057 | ||
5d0d5d68 | 3058 | if (lenrange[0] == cntrange[1] && cntrange[0] == cntrange[1]) |
1c89478a MS |
3059 | return warning_n (callloc, OPT_Wstringop_truncation, |
3060 | cntrange[0].to_uhwi (), | |
6d3bab5d | 3061 | "%qD output truncated before terminating " |
1c89478a MS |
3062 | "nul copying %E byte from a string of the " |
3063 | "same length", | |
6d3bab5d | 3064 | "%qD output truncated before terminating nul " |
1c89478a MS |
3065 | "copying %E bytes from a string of the same " |
3066 | "length", | |
6d3bab5d | 3067 | func, cnt); |
eec5f615 | 3068 | else if (!cat_dstlen_bounded) |
025d57f0 | 3069 | { |
eec5f615 MS |
3070 | if (wi::geu_p (lenrange[0], cntrange[1])) |
3071 | { | |
3072 | /* The shortest string is longer than the upper bound of | |
3073 | the count so the truncation is certain. */ | |
3074 | if (cntrange[0] == cntrange[1]) | |
3075 | return warning_n (callloc, OPT_Wstringop_truncation, | |
3076 | cntrange[0].to_uhwi (), | |
6d3bab5d | 3077 | "%qD output truncated copying %E byte " |
eec5f615 | 3078 | "from a string of length %wu", |
6d3bab5d | 3079 | "%qD output truncated copying %E bytes " |
eec5f615 | 3080 | "from a string of length %wu", |
6d3bab5d | 3081 | func, cnt, lenrange[0].to_uhwi ()); |
eec5f615 MS |
3082 | |
3083 | return warning_at (callloc, OPT_Wstringop_truncation, | |
6d3bab5d | 3084 | "%qD output truncated copying between %wu " |
eec5f615 | 3085 | "and %wu bytes from a string of length %wu", |
6d3bab5d | 3086 | func, cntrange[0].to_uhwi (), |
eec5f615 MS |
3087 | cntrange[1].to_uhwi (), lenrange[0].to_uhwi ()); |
3088 | } | |
3089 | else if (wi::geu_p (lenrange[1], cntrange[1])) | |
3090 | { | |
3091 | /* The longest string is longer than the upper bound of | |
3092 | the count so the truncation is possible. */ | |
3093 | if (cntrange[0] == cntrange[1]) | |
3094 | return warning_n (callloc, OPT_Wstringop_truncation, | |
3095 | cntrange[0].to_uhwi (), | |
6d3bab5d | 3096 | "%qD output may be truncated copying %E " |
eec5f615 | 3097 | "byte from a string of length %wu", |
6d3bab5d | 3098 | "%qD output may be truncated copying %E " |
eec5f615 | 3099 | "bytes from a string of length %wu", |
6d3bab5d | 3100 | func, cnt, lenrange[1].to_uhwi ()); |
eec5f615 MS |
3101 | |
3102 | return warning_at (callloc, OPT_Wstringop_truncation, | |
6d3bab5d | 3103 | "%qD output may be truncated copying between " |
eec5f615 | 3104 | "%wu and %wu bytes from a string of length %wu", |
6d3bab5d | 3105 | func, cntrange[0].to_uhwi (), |
eec5f615 MS |
3106 | cntrange[1].to_uhwi (), lenrange[1].to_uhwi ()); |
3107 | } | |
025d57f0 MS |
3108 | } |
3109 | ||
eec5f615 MS |
3110 | if (!cat_dstlen_bounded |
3111 | && cntrange[0] != cntrange[1] | |
025d57f0 MS |
3112 | && wi::leu_p (cntrange[0], lenrange[0]) |
3113 | && wi::leu_p (cntrange[1], lenrange[0] + 1)) | |
3114 | { | |
3115 | /* If the source (including the terminating nul) is longer than | |
3116 | the lower bound of the specified count but shorter than the | |
3117 | upper bound the copy may (but need not) be truncated. */ | |
3118 | return warning_at (callloc, OPT_Wstringop_truncation, | |
6d3bab5d | 3119 | "%qD output may be truncated copying between " |
5d0d5d68 | 3120 | "%wu and %wu bytes from a string of length %wu", |
6d3bab5d | 3121 | func, cntrange[0].to_uhwi (), |
025d57f0 MS |
3122 | cntrange[1].to_uhwi (), lenrange[0].to_uhwi ()); |
3123 | } | |
3124 | } | |
3125 | ||
d02c41dd | 3126 | access_ref aref; |
9a27acc3 | 3127 | if (tree dstsize = compute_objsize (dst, stmt, 1, &aref, ptr_qry)) |
025d57f0 | 3128 | { |
dfea3d6f | 3129 | /* The source length is unknown. Try to determine the destination |
025d57f0 MS |
3130 | size and see if it matches the specified bound. If not, bail. |
3131 | Otherwise go on to see if it should be diagnosed for possible | |
3132 | truncation. */ | |
3133 | if (!dstsize) | |
3134 | return false; | |
3135 | ||
3136 | if (wi::to_wide (dstsize) != cntrange[1]) | |
3137 | return false; | |
3138 | ||
3a03bffd MS |
3139 | /* Avoid warning for strncpy(a, b, N) calls where the following |
3140 | equalities hold: | |
3141 | N == sizeof a && N == sizeof b */ | |
9a27acc3 | 3142 | if (tree srcsize = compute_objsize (src, stmt, 1, &aref, ptr_qry)) |
3a03bffd MS |
3143 | if (wi::to_wide (srcsize) == cntrange[1]) |
3144 | return false; | |
3145 | ||
025d57f0 MS |
3146 | if (cntrange[0] == cntrange[1]) |
3147 | return warning_at (callloc, OPT_Wstringop_truncation, | |
6d3bab5d MS |
3148 | "%qD specified bound %E equals destination size", |
3149 | func, cnt); | |
025d57f0 MS |
3150 | } |
3151 | ||
3152 | return false; | |
3153 | } | |
3154 | ||
0a0de963 MS |
3155 | /* Check the arguments to the built-in forms of stpncpy, strncpy, and |
3156 | strncat, for out-of-bounds offsets or overlapping access, and to see | |
3157 | if the size is derived from calling strlen() on the source argument, | |
3158 | and if so, issue the appropriate warning. | |
3159 | APPEND_P is true for strncat. */ | |
025d57f0 | 3160 | |
47e4ab65 AH |
3161 | void |
3162 | strlen_pass::handle_builtin_stxncpy_strncat (bool append_p) | |
025d57f0 | 3163 | { |
6a33d0ff MS |
3164 | if (!strlen_to_stridx) |
3165 | return; | |
3166 | ||
47e4ab65 | 3167 | gimple *stmt = gsi_stmt (m_gsi); |
025d57f0 | 3168 | |
31db0fe0 ML |
3169 | tree dst = gimple_call_arg (stmt, 0); |
3170 | tree src = gimple_call_arg (stmt, 1); | |
3171 | tree len = gimple_call_arg (stmt, 2); | |
7f5ff78f MS |
3172 | /* An upper bound of the size of the destination. */ |
3173 | tree dstsize = NULL_TREE; | |
3174 | /* The length of the destination and source strings (plus 1 for those | |
3175 | whose FULL_STRING_P is set, i.e., whose length is exact rather than | |
3176 | a lower bound). */ | |
3177 | tree dstlenp1 = NULL_TREE, srclenp1 = NULL_TREE;; | |
cc8bea0a | 3178 | |
6b8b9596 | 3179 | int didx = get_stridx (dst, stmt); |
cc8bea0a MS |
3180 | if (strinfo *sidst = didx > 0 ? get_strinfo (didx) : NULL) |
3181 | { | |
e3ba46bd MS |
3182 | /* Compute the size of the destination string including the nul |
3183 | if it is known to be nul-terminated. */ | |
cc8bea0a MS |
3184 | if (sidst->nonzero_chars) |
3185 | { | |
e0748030 | 3186 | if (sidst->full_string_p) |
e3ba46bd MS |
3187 | { |
3188 | /* String is known to be nul-terminated. */ | |
3189 | tree type = TREE_TYPE (sidst->nonzero_chars); | |
7f5ff78f | 3190 | dstlenp1 = fold_build2 (PLUS_EXPR, type, sidst->nonzero_chars, |
e3ba46bd MS |
3191 | build_int_cst (type, 1)); |
3192 | } | |
3193 | else | |
7f5ff78f MS |
3194 | dstlenp1 = sidst->nonzero_chars; |
3195 | } | |
3196 | else if (TREE_CODE (sidst->ptr) == SSA_NAME) | |
3197 | { | |
3198 | gimple *def_stmt = SSA_NAME_DEF_STMT (sidst->ptr); | |
3199 | dstsize = gimple_call_alloc_size (def_stmt); | |
cc8bea0a | 3200 | } |
e3ba46bd | 3201 | |
cc8bea0a MS |
3202 | dst = sidst->ptr; |
3203 | } | |
3204 | ||
6b8b9596 | 3205 | int sidx = get_stridx (src, stmt); |
cc8bea0a MS |
3206 | strinfo *sisrc = sidx > 0 ? get_strinfo (sidx) : NULL; |
3207 | if (sisrc) | |
3208 | { | |
3209 | /* strncat() and strncpy() can modify the source string by writing | |
3210 | over the terminating nul so SISRC->DONT_INVALIDATE must be left | |
3211 | clear. */ | |
3212 | ||
e3ba46bd MS |
3213 | /* Compute the size of the source string including the terminating |
3214 | nul if its known to be nul-terminated. */ | |
cc8bea0a MS |
3215 | if (sisrc->nonzero_chars) |
3216 | { | |
e0748030 | 3217 | if (sisrc->full_string_p) |
e3ba46bd MS |
3218 | { |
3219 | tree type = TREE_TYPE (sisrc->nonzero_chars); | |
7f5ff78f | 3220 | srclenp1 = fold_build2 (PLUS_EXPR, type, sisrc->nonzero_chars, |
e3ba46bd MS |
3221 | build_int_cst (type, 1)); |
3222 | } | |
3223 | else | |
7f5ff78f | 3224 | srclenp1 = sisrc->nonzero_chars; |
cc8bea0a MS |
3225 | } |
3226 | ||
3227 | src = sisrc->ptr; | |
3228 | } | |
3229 | else | |
7f5ff78f | 3230 | srclenp1 = NULL_TREE; |
cc8bea0a | 3231 | |
e9e2bad7 MS |
3232 | opt_code opt = check_bounds_or_overlap (stmt, dst, src, dstlenp1, srclenp1); |
3233 | if (opt != no_warning) | |
cc8bea0a | 3234 | { |
e9e2bad7 | 3235 | suppress_warning (stmt, opt); |
cc8bea0a MS |
3236 | return; |
3237 | } | |
025d57f0 MS |
3238 | |
3239 | /* If the length argument was computed from strlen(S) for some string | |
dfea3d6f | 3240 | S retrieve the strinfo index for the string (PSS->FIRST) along with |
025d57f0 | 3241 | the location of the strlen() call (PSS->SECOND). */ |
6a33d0ff | 3242 | stridx_strlenloc *pss = strlen_to_stridx->get (len); |
025d57f0 MS |
3243 | if (!pss || pss->first <= 0) |
3244 | { | |
47e4ab65 | 3245 | if (maybe_diag_stxncpy_trunc (m_gsi, src, len)) |
e9e2bad7 | 3246 | suppress_warning (stmt, OPT_Wstringop_truncation); |
025d57f0 MS |
3247 | |
3248 | return; | |
3249 | } | |
3250 | ||
025d57f0 MS |
3251 | /* Retrieve the strinfo data for the string S that LEN was computed |
3252 | from as some function F of strlen (S) (i.e., LEN need not be equal | |
3253 | to strlen(S)). */ | |
3254 | strinfo *silen = get_strinfo (pss->first); | |
3255 | ||
55ace4d1 | 3256 | location_t callloc = gimple_or_expr_nonartificial_location (stmt, dst); |
025d57f0 MS |
3257 | |
3258 | tree func = gimple_call_fndecl (stmt); | |
3259 | ||
3260 | bool warned = false; | |
3261 | ||
3262 | /* When -Wstringop-truncation is set, try to determine truncation | |
3263 | before diagnosing possible overflow. Truncation is implied by | |
3264 | the LEN argument being equal to strlen(SRC), regardless of | |
7f5ff78f MS |
3265 | whether its value is known. Otherwise, when appending, or |
3266 | when copying into a destination of known size, issue the more | |
3267 | generic -Wstringop-overflow which triggers for LEN arguments | |
3268 | that in any meaningful way depend on strlen(SRC). */ | |
0a0de963 MS |
3269 | if (!append_p |
3270 | && sisrc == silen | |
6a33d0ff MS |
3271 | && is_strlen_related_p (src, len) |
3272 | && warning_at (callloc, OPT_Wstringop_truncation, | |
6d3bab5d | 3273 | "%qD output truncated before terminating nul " |
6a33d0ff | 3274 | "copying as many bytes from a string as its length", |
6d3bab5d | 3275 | func)) |
6a33d0ff | 3276 | warned = true; |
7f5ff78f MS |
3277 | else if ((append_p || !dstsize || len == dstlenp1) |
3278 | && silen && is_strlen_related_p (src, silen->ptr)) | |
3279 | { | |
3280 | /* Issue -Wstringop-overflow when appending or when writing into | |
3281 | a destination of a known size. Otherwise, when copying into | |
3282 | a destination of an unknown size, it's truncation. */ | |
e9e2bad7 MS |
3283 | opt_code opt = (append_p || dstsize |
3284 | ? OPT_Wstringop_overflow_ : OPT_Wstringop_truncation); | |
7f5ff78f | 3285 | warned = warning_at (callloc, opt, |
6d3bab5d | 3286 | "%qD specified bound depends on the length " |
7f5ff78f | 3287 | "of the source argument", |
6d3bab5d | 3288 | func); |
7f5ff78f | 3289 | } |
025d57f0 MS |
3290 | if (warned) |
3291 | { | |
3292 | location_t strlenloc = pss->second; | |
3293 | if (strlenloc != UNKNOWN_LOCATION && strlenloc != callloc) | |
3294 | inform (strlenloc, "length computed here"); | |
3295 | } | |
3296 | } | |
3297 | ||
8b57bfeb JJ |
3298 | /* Handle a memcpy-like ({mem{,p}cpy,__mem{,p}cpy_chk}) call. |
3299 | If strlen of the second argument is known and length of the third argument | |
3300 | is that plus one, strlen of the first argument is the same after this | |
ef29b12c | 3301 | call. Uses RVALS to determine range information. */ |
8b57bfeb | 3302 | |
47e4ab65 AH |
3303 | void |
3304 | strlen_pass::handle_builtin_memcpy (built_in_function bcode) | |
8b57bfeb | 3305 | { |
ef29b12c | 3306 | tree lhs, oldlen, newlen; |
47e4ab65 | 3307 | gimple *stmt = gsi_stmt (m_gsi); |
ef29b12c | 3308 | strinfo *si, *dsi; |
8b57bfeb | 3309 | |
ef29b12c MS |
3310 | tree len = gimple_call_arg (stmt, 2); |
3311 | tree src = gimple_call_arg (stmt, 1); | |
3312 | tree dst = gimple_call_arg (stmt, 0); | |
8b57bfeb | 3313 | |
6b8b9596 | 3314 | int didx = get_stridx (dst, stmt); |
ef29b12c | 3315 | strinfo *olddsi = NULL; |
8b57bfeb JJ |
3316 | if (didx > 0) |
3317 | olddsi = get_strinfo (didx); | |
3318 | else if (didx < 0) | |
3319 | return; | |
3320 | ||
3321 | if (olddsi != NULL | |
8b57bfeb | 3322 | && !integer_zerop (len)) |
ef29b12c | 3323 | { |
47e4ab65 AH |
3324 | maybe_warn_overflow (stmt, false, len, olddsi, false, true); |
3325 | adjust_last_stmt (olddsi, stmt, false); | |
ef29b12c MS |
3326 | } |
3327 | ||
6b8b9596 | 3328 | int idx = get_stridx (src, stmt); |
ef29b12c MS |
3329 | if (idx == 0) |
3330 | return; | |
8b57bfeb | 3331 | |
e3f9a279 | 3332 | bool full_string_p; |
8b57bfeb JJ |
3333 | if (idx > 0) |
3334 | { | |
355fe088 | 3335 | gimple *def_stmt; |
8b57bfeb | 3336 | |
e3f9a279 RS |
3337 | /* Handle memcpy (x, y, l) where l's relationship with strlen (y) |
3338 | is known. */ | |
8b57bfeb | 3339 | si = get_strinfo (idx); |
e3f9a279 | 3340 | if (si == NULL || si->nonzero_chars == NULL_TREE) |
8b57bfeb | 3341 | return; |
e3f9a279 RS |
3342 | if (TREE_CODE (len) == INTEGER_CST |
3343 | && TREE_CODE (si->nonzero_chars) == INTEGER_CST) | |
3344 | { | |
3345 | if (tree_int_cst_le (len, si->nonzero_chars)) | |
3346 | { | |
3347 | /* Copying LEN nonzero characters, where LEN is constant. */ | |
3348 | newlen = len; | |
3349 | full_string_p = false; | |
3350 | } | |
3351 | else | |
3352 | { | |
3353 | /* Copying the whole of the analyzed part of SI. */ | |
3354 | newlen = si->nonzero_chars; | |
3355 | full_string_p = si->full_string_p; | |
3356 | } | |
3357 | } | |
3358 | else | |
3359 | { | |
3360 | if (!si->full_string_p) | |
3361 | return; | |
3362 | if (TREE_CODE (len) != SSA_NAME) | |
3363 | return; | |
3364 | def_stmt = SSA_NAME_DEF_STMT (len); | |
3365 | if (!is_gimple_assign (def_stmt) | |
3366 | || gimple_assign_rhs_code (def_stmt) != PLUS_EXPR | |
3367 | || gimple_assign_rhs1 (def_stmt) != si->nonzero_chars | |
3368 | || !integer_onep (gimple_assign_rhs2 (def_stmt))) | |
3369 | return; | |
3370 | /* Copying variable-length string SI (and no more). */ | |
3371 | newlen = si->nonzero_chars; | |
3372 | full_string_p = true; | |
3373 | } | |
8b57bfeb JJ |
3374 | } |
3375 | else | |
3376 | { | |
3377 | si = NULL; | |
3378 | /* Handle memcpy (x, "abcd", 5) or | |
3379 | memcpy (x, "abc\0uvw", 7). */ | |
e3f9a279 | 3380 | if (!tree_fits_uhwi_p (len)) |
8b57bfeb | 3381 | return; |
e3f9a279 RS |
3382 | |
3383 | unsigned HOST_WIDE_INT clen = tree_to_uhwi (len); | |
3384 | unsigned HOST_WIDE_INT nonzero_chars = ~idx; | |
3385 | newlen = build_int_cst (size_type_node, MIN (nonzero_chars, clen)); | |
3386 | full_string_p = clen > nonzero_chars; | |
8b57bfeb JJ |
3387 | } |
3388 | ||
aca8570e MS |
3389 | if (!full_string_p |
3390 | && olddsi | |
3391 | && olddsi->nonzero_chars | |
3392 | && TREE_CODE (olddsi->nonzero_chars) == INTEGER_CST | |
3393 | && tree_int_cst_le (newlen, olddsi->nonzero_chars)) | |
3394 | { | |
3395 | /* The SRC substring being written strictly overlaps | |
3396 | a subsequence of the existing string OLDDSI. */ | |
3397 | newlen = olddsi->nonzero_chars; | |
3398 | full_string_p = olddsi->full_string_p; | |
3399 | } | |
3400 | ||
8b57bfeb | 3401 | if (olddsi != NULL && TREE_CODE (len) == SSA_NAME) |
47e4ab65 | 3402 | adjust_last_stmt (olddsi, stmt, false); |
8b57bfeb JJ |
3403 | |
3404 | if (didx == 0) | |
3405 | { | |
3406 | didx = new_stridx (dst); | |
3407 | if (didx == 0) | |
3408 | return; | |
3409 | } | |
8b57bfeb JJ |
3410 | oldlen = NULL_TREE; |
3411 | if (olddsi != NULL) | |
3412 | { | |
3413 | dsi = unshare_strinfo (olddsi); | |
e3f9a279 RS |
3414 | oldlen = olddsi->nonzero_chars; |
3415 | dsi->nonzero_chars = newlen; | |
3416 | dsi->full_string_p = full_string_p; | |
8b57bfeb JJ |
3417 | /* Break the chain, so adjust_related_strinfo on later pointers in |
3418 | the chain won't adjust this one anymore. */ | |
3419 | dsi->next = 0; | |
3420 | dsi->stmt = NULL; | |
3421 | dsi->endptr = NULL_TREE; | |
3422 | } | |
3423 | else | |
3424 | { | |
e3f9a279 | 3425 | dsi = new_strinfo (dst, didx, newlen, full_string_p); |
8b57bfeb JJ |
3426 | set_strinfo (didx, dsi); |
3427 | find_equal_ptrs (dst, didx); | |
3428 | } | |
3429 | dsi->writable = true; | |
3430 | dsi->dont_invalidate = true; | |
3431 | if (olddsi != NULL) | |
3432 | { | |
3433 | tree adj = NULL_TREE; | |
3434 | location_t loc = gimple_location (stmt); | |
3435 | if (oldlen == NULL_TREE) | |
3436 | ; | |
3437 | else if (integer_zerop (oldlen)) | |
e3f9a279 | 3438 | adj = newlen; |
8b57bfeb | 3439 | else if (TREE_CODE (oldlen) == INTEGER_CST |
e3f9a279 RS |
3440 | || TREE_CODE (newlen) == INTEGER_CST) |
3441 | adj = fold_build2_loc (loc, MINUS_EXPR, TREE_TYPE (newlen), newlen, | |
3442 | fold_convert_loc (loc, TREE_TYPE (newlen), | |
8b57bfeb JJ |
3443 | oldlen)); |
3444 | if (adj != NULL_TREE) | |
3445 | adjust_related_strinfos (loc, dsi, adj); | |
3446 | else | |
3447 | dsi->prev = 0; | |
3448 | } | |
3449 | /* memcpy src may not overlap dst, so src doesn't need to be | |
3450 | invalidated either. */ | |
3451 | if (si != NULL) | |
3452 | si->dont_invalidate = true; | |
3453 | ||
e3f9a279 | 3454 | if (full_string_p) |
8b57bfeb | 3455 | { |
e3f9a279 RS |
3456 | lhs = gimple_call_lhs (stmt); |
3457 | switch (bcode) | |
3458 | { | |
3459 | case BUILT_IN_MEMCPY: | |
3460 | case BUILT_IN_MEMCPY_CHK: | |
e3f9a279 RS |
3461 | /* Allow adjust_last_stmt to decrease this memcpy's size. */ |
3462 | laststmt.stmt = stmt; | |
3463 | laststmt.len = dsi->nonzero_chars; | |
3464 | laststmt.stridx = dsi->idx; | |
3465 | if (lhs) | |
3466 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] = didx; | |
3467 | break; | |
3468 | case BUILT_IN_MEMPCPY: | |
3469 | case BUILT_IN_MEMPCPY_CHK: | |
e3f9a279 RS |
3470 | break; |
3471 | default: | |
3472 | gcc_unreachable (); | |
3473 | } | |
8b57bfeb JJ |
3474 | } |
3475 | } | |
3476 | ||
3477 | /* Handle a strcat-like ({strcat,__strcat_chk}) call. | |
3478 | If strlen of the second argument is known, strlen of the first argument | |
3479 | is increased by the length of the second argument. Furthermore, attempt | |
3480 | to convert it to memcpy/strcpy if the length of the first argument | |
3481 | is known. */ | |
3482 | ||
47e4ab65 AH |
3483 | void |
3484 | strlen_pass::handle_builtin_strcat (built_in_function bcode) | |
8b57bfeb JJ |
3485 | { |
3486 | int idx, didx; | |
cc8bea0a | 3487 | tree srclen, args, type, fn, objsz, endptr; |
8b57bfeb | 3488 | bool success; |
47e4ab65 | 3489 | gimple *stmt = gsi_stmt (m_gsi); |
526ceb68 | 3490 | strinfo *si, *dsi; |
cc8bea0a | 3491 | location_t loc = gimple_location (stmt); |
8b57bfeb | 3492 | |
31db0fe0 | 3493 | tree src = gimple_call_arg (stmt, 1); |
cc8bea0a MS |
3494 | tree dst = gimple_call_arg (stmt, 0); |
3495 | ||
3496 | /* Bail if the source is the same as destination. It will be diagnosed | |
3497 | elsewhere. */ | |
3498 | if (operand_equal_p (src, dst, 0)) | |
3499 | return; | |
3500 | ||
3501 | tree lhs = gimple_call_lhs (stmt); | |
8b57bfeb | 3502 | |
6b8b9596 | 3503 | didx = get_stridx (dst, stmt); |
8b57bfeb JJ |
3504 | if (didx < 0) |
3505 | return; | |
3506 | ||
3507 | dsi = NULL; | |
3508 | if (didx > 0) | |
3509 | dsi = get_strinfo (didx); | |
cc8bea0a MS |
3510 | |
3511 | srclen = NULL_TREE; | |
3512 | si = NULL; | |
6b8b9596 | 3513 | idx = get_stridx (src, stmt); |
cc8bea0a MS |
3514 | if (idx < 0) |
3515 | srclen = build_int_cst (size_type_node, ~idx); | |
3516 | else if (idx > 0) | |
3517 | { | |
3518 | si = get_strinfo (idx); | |
3519 | if (si != NULL) | |
3520 | srclen = get_string_length (si); | |
3521 | } | |
3522 | ||
e9e2bad7 MS |
3523 | /* Disable warning for the transformed statement? */ |
3524 | opt_code no_warning_opt = no_warning; | |
cc8bea0a | 3525 | |
8b57bfeb JJ |
3526 | if (dsi == NULL || get_string_length (dsi) == NULL_TREE) |
3527 | { | |
cc8bea0a MS |
3528 | { |
3529 | /* The concatenation always involves copying at least one byte | |
3530 | (the terminating nul), even if the source string is empty. | |
3531 | If the source is unknown assume it's one character long and | |
3532 | used that as both sizes. */ | |
3533 | tree slen = srclen; | |
3534 | if (slen) | |
3535 | { | |
3536 | tree type = TREE_TYPE (slen); | |
3537 | slen = fold_build2 (PLUS_EXPR, type, slen, build_int_cst (type, 1)); | |
3538 | } | |
3539 | ||
3540 | tree sptr = si && si->ptr ? si->ptr : src; | |
e9e2bad7 MS |
3541 | no_warning_opt = check_bounds_or_overlap (stmt, dst, sptr, NULL_TREE, |
3542 | slen); | |
3543 | if (no_warning_opt) | |
3544 | suppress_warning (stmt, no_warning_opt); | |
cc8bea0a MS |
3545 | } |
3546 | ||
8b57bfeb | 3547 | /* strcat (p, q) can be transformed into |
cc8bea0a | 3548 | tmp = p + strlen (p); endptr = stpcpy (tmp, q); |
8b57bfeb JJ |
3549 | with length endptr - p if we need to compute the length |
3550 | later on. Don't do this transformation if we don't need | |
3551 | it. */ | |
e79983f4 | 3552 | if (builtin_decl_implicit_p (BUILT_IN_STPCPY) && lhs == NULL_TREE) |
8b57bfeb JJ |
3553 | { |
3554 | if (didx == 0) | |
3555 | { | |
3556 | didx = new_stridx (dst); | |
3557 | if (didx == 0) | |
3558 | return; | |
3559 | } | |
3560 | if (dsi == NULL) | |
3561 | { | |
e3f9a279 | 3562 | dsi = new_strinfo (dst, didx, NULL_TREE, false); |
8b57bfeb JJ |
3563 | set_strinfo (didx, dsi); |
3564 | find_equal_ptrs (dst, didx); | |
3565 | } | |
3566 | else | |
3567 | { | |
3568 | dsi = unshare_strinfo (dsi); | |
e3f9a279 RS |
3569 | dsi->nonzero_chars = NULL_TREE; |
3570 | dsi->full_string_p = false; | |
8b57bfeb JJ |
3571 | dsi->next = 0; |
3572 | dsi->endptr = NULL_TREE; | |
3573 | } | |
3574 | dsi->writable = true; | |
3575 | dsi->stmt = stmt; | |
3576 | dsi->dont_invalidate = true; | |
3577 | } | |
3578 | return; | |
3579 | } | |
3580 | ||
cc8bea0a | 3581 | tree dstlen = dsi->nonzero_chars; |
8b57bfeb JJ |
3582 | endptr = dsi->endptr; |
3583 | ||
3584 | dsi = unshare_strinfo (dsi); | |
3585 | dsi->endptr = NULL_TREE; | |
3586 | dsi->stmt = NULL; | |
3587 | dsi->writable = true; | |
3588 | ||
3589 | if (srclen != NULL_TREE) | |
3590 | { | |
e3f9a279 RS |
3591 | dsi->nonzero_chars = fold_build2_loc (loc, PLUS_EXPR, |
3592 | TREE_TYPE (dsi->nonzero_chars), | |
3593 | dsi->nonzero_chars, srclen); | |
3594 | gcc_assert (dsi->full_string_p); | |
8b57bfeb JJ |
3595 | adjust_related_strinfos (loc, dsi, srclen); |
3596 | dsi->dont_invalidate = true; | |
3597 | } | |
3598 | else | |
3599 | { | |
e3f9a279 RS |
3600 | dsi->nonzero_chars = NULL; |
3601 | dsi->full_string_p = false; | |
e79983f4 | 3602 | if (lhs == NULL_TREE && builtin_decl_implicit_p (BUILT_IN_STPCPY)) |
8b57bfeb JJ |
3603 | dsi->dont_invalidate = true; |
3604 | } | |
3605 | ||
3606 | if (si != NULL) | |
3607 | /* strcat src may not overlap dst, so src doesn't need to be | |
3608 | invalidated either. */ | |
3609 | si->dont_invalidate = true; | |
3610 | ||
3611 | /* For now. Could remove the lhs from the call and add | |
3612 | lhs = dst; afterwards. */ | |
3613 | if (lhs) | |
3614 | return; | |
3615 | ||
3616 | fn = NULL_TREE; | |
3617 | objsz = NULL_TREE; | |
3618 | switch (bcode) | |
3619 | { | |
3620 | case BUILT_IN_STRCAT: | |
3621 | if (srclen != NULL_TREE) | |
e79983f4 | 3622 | fn = builtin_decl_implicit (BUILT_IN_MEMCPY); |
8b57bfeb | 3623 | else |
e79983f4 | 3624 | fn = builtin_decl_implicit (BUILT_IN_STRCPY); |
8b57bfeb JJ |
3625 | break; |
3626 | case BUILT_IN_STRCAT_CHK: | |
3627 | if (srclen != NULL_TREE) | |
e79983f4 | 3628 | fn = builtin_decl_explicit (BUILT_IN_MEMCPY_CHK); |
8b57bfeb | 3629 | else |
e79983f4 | 3630 | fn = builtin_decl_explicit (BUILT_IN_STRCPY_CHK); |
31db0fe0 | 3631 | objsz = gimple_call_arg (stmt, 2); |
8b57bfeb JJ |
3632 | break; |
3633 | default: | |
3634 | gcc_unreachable (); | |
3635 | } | |
3636 | ||
3637 | if (fn == NULL_TREE) | |
3638 | return; | |
3639 | ||
cc8bea0a MS |
3640 | if (dsi && dstlen) |
3641 | { | |
3642 | tree type = TREE_TYPE (dstlen); | |
3643 | ||
3644 | /* Compute the size of the source sequence, including the nul. */ | |
3645 | tree srcsize = srclen ? srclen : size_zero_node; | |
6889a3ac MS |
3646 | tree one = build_int_cst (type, 1); |
3647 | srcsize = fold_build2 (PLUS_EXPR, type, srcsize, one); | |
3648 | tree dstsize = fold_build2 (PLUS_EXPR, type, dstlen, one); | |
cc8bea0a MS |
3649 | tree sptr = si && si->ptr ? si->ptr : src; |
3650 | ||
e9e2bad7 MS |
3651 | no_warning_opt = check_bounds_or_overlap (stmt, dst, sptr, dstsize, |
3652 | srcsize); | |
3653 | if (no_warning_opt) | |
3654 | suppress_warning (stmt, no_warning_opt); | |
cc8bea0a MS |
3655 | } |
3656 | ||
3657 | tree len = NULL_TREE; | |
8b57bfeb JJ |
3658 | if (srclen != NULL_TREE) |
3659 | { | |
3660 | args = TYPE_ARG_TYPES (TREE_TYPE (fn)); | |
3661 | type = TREE_VALUE (TREE_CHAIN (TREE_CHAIN (args))); | |
3662 | ||
3663 | len = fold_convert_loc (loc, type, unshare_expr (srclen)); | |
3664 | len = fold_build2_loc (loc, PLUS_EXPR, type, len, | |
3665 | build_int_cst (type, 1)); | |
47e4ab65 | 3666 | len = force_gimple_operand_gsi (&m_gsi, len, true, NULL_TREE, true, |
8b57bfeb JJ |
3667 | GSI_SAME_STMT); |
3668 | } | |
3669 | if (endptr) | |
3670 | dst = fold_convert_loc (loc, TREE_TYPE (dst), unshare_expr (endptr)); | |
3671 | else | |
770fe3a3 | 3672 | dst = fold_build2_loc (loc, POINTER_PLUS_EXPR, TREE_TYPE (dst), dst, |
8b57bfeb JJ |
3673 | fold_convert_loc (loc, sizetype, |
3674 | unshare_expr (dstlen))); | |
47e4ab65 | 3675 | dst = force_gimple_operand_gsi (&m_gsi, dst, true, NULL_TREE, true, |
8b57bfeb | 3676 | GSI_SAME_STMT); |
770fe3a3 BE |
3677 | if (objsz) |
3678 | { | |
3679 | objsz = fold_build2_loc (loc, MINUS_EXPR, TREE_TYPE (objsz), objsz, | |
3680 | fold_convert_loc (loc, TREE_TYPE (objsz), | |
3681 | unshare_expr (dstlen))); | |
47e4ab65 | 3682 | objsz = force_gimple_operand_gsi (&m_gsi, objsz, true, NULL_TREE, true, |
770fe3a3 BE |
3683 | GSI_SAME_STMT); |
3684 | } | |
8b57bfeb JJ |
3685 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) |
3686 | { | |
3687 | fprintf (dump_file, "Optimizing: "); | |
3688 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
3689 | } | |
31db0fe0 | 3690 | if (srclen != NULL_TREE) |
47e4ab65 | 3691 | success = update_gimple_call (&m_gsi, fn, 3 + (objsz != NULL_TREE), |
31db0fe0 | 3692 | dst, src, len, objsz); |
8b57bfeb | 3693 | else |
47e4ab65 | 3694 | success = update_gimple_call (&m_gsi, fn, 2 + (objsz != NULL_TREE), |
31db0fe0 | 3695 | dst, src, objsz); |
8b57bfeb JJ |
3696 | if (success) |
3697 | { | |
47e4ab65 | 3698 | stmt = gsi_stmt (m_gsi); |
8b57bfeb JJ |
3699 | update_stmt (stmt); |
3700 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
3701 | { | |
3702 | fprintf (dump_file, "into: "); | |
3703 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
3704 | } | |
3705 | /* If srclen == NULL, note that current string length can be | |
3706 | computed by transforming this strcpy into stpcpy. */ | |
3707 | if (srclen == NULL_TREE && dsi->dont_invalidate) | |
3708 | dsi->stmt = stmt; | |
47e4ab65 | 3709 | adjust_last_stmt (dsi, stmt, true); |
8b57bfeb JJ |
3710 | if (srclen != NULL_TREE) |
3711 | { | |
3712 | laststmt.stmt = stmt; | |
3713 | laststmt.len = srclen; | |
3714 | laststmt.stridx = dsi->idx; | |
3715 | } | |
3716 | } | |
3717 | else if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
3718 | fprintf (dump_file, "not possible.\n"); | |
cc8bea0a | 3719 | |
e9e2bad7 MS |
3720 | if (no_warning_opt) |
3721 | suppress_warning (stmt, no_warning_opt); | |
8b57bfeb JJ |
3722 | } |
3723 | ||
ef29b12c MS |
3724 | /* Handle a call to an allocation function like alloca, malloc or calloc, |
3725 | or an ordinary allocation function declared with attribute alloc_size. */ | |
24314386 | 3726 | |
47e4ab65 AH |
3727 | void |
3728 | strlen_pass::handle_alloc_call (built_in_function bcode) | |
24314386 | 3729 | { |
47e4ab65 | 3730 | gimple *stmt = gsi_stmt (m_gsi); |
24314386 | 3731 | tree lhs = gimple_call_lhs (stmt); |
a71dcca8 ML |
3732 | if (lhs == NULL_TREE) |
3733 | return; | |
3734 | ||
6b8b9596 | 3735 | gcc_assert (get_stridx (lhs, stmt) == 0); |
24314386 MG |
3736 | int idx = new_stridx (lhs); |
3737 | tree length = NULL_TREE; | |
3738 | if (bcode == BUILT_IN_CALLOC) | |
3739 | length = build_int_cst (size_type_node, 0); | |
e3f9a279 | 3740 | strinfo *si = new_strinfo (lhs, idx, length, length != NULL_TREE); |
24314386 | 3741 | if (bcode == BUILT_IN_CALLOC) |
ef29b12c MS |
3742 | { |
3743 | /* Only set STMT for calloc and malloc. */ | |
3744 | si->stmt = stmt; | |
3745 | /* Only set ENDPTR for calloc. */ | |
3746 | si->endptr = lhs; | |
3747 | } | |
3748 | else if (bcode == BUILT_IN_MALLOC) | |
3749 | si->stmt = stmt; | |
3750 | ||
3751 | /* Set ALLOC is set for all allocation functions. */ | |
3752 | si->alloc = stmt; | |
24314386 MG |
3753 | set_strinfo (idx, si); |
3754 | si->writable = true; | |
24314386 MG |
3755 | si->dont_invalidate = true; |
3756 | } | |
3757 | ||
3758 | /* Handle a call to memset. | |
3759 | After a call to calloc, memset(,0,) is unnecessary. | |
21722777 | 3760 | memset(malloc(n),0,n) is calloc(n,1). |
ef29b12c MS |
3761 | return true when the call is transformed, false otherwise. |
3762 | When nonnull uses RVALS to determine range information. */ | |
24314386 | 3763 | |
47e4ab65 AH |
3764 | bool |
3765 | strlen_pass::handle_builtin_memset (bool *zero_write) | |
24314386 | 3766 | { |
47e4ab65 | 3767 | gimple *memset_stmt = gsi_stmt (m_gsi); |
ef29b12c MS |
3768 | tree ptr = gimple_call_arg (memset_stmt, 0); |
3769 | /* Set to the non-constant offset added to PTR. */ | |
3770 | wide_int offrng[2]; | |
6b8b9596 | 3771 | int idx1 = get_stridx (ptr, memset_stmt, offrng, ptr_qry.rvals); |
24314386 | 3772 | if (idx1 <= 0) |
8b0b334a | 3773 | return false; |
526ceb68 | 3774 | strinfo *si1 = get_strinfo (idx1); |
24314386 | 3775 | if (!si1) |
8b0b334a | 3776 | return false; |
ef29b12c MS |
3777 | gimple *alloc_stmt = si1->alloc; |
3778 | if (!alloc_stmt || !is_gimple_call (alloc_stmt)) | |
3779 | return false; | |
3780 | tree callee1 = gimple_call_fndecl (alloc_stmt); | |
3781 | if (!valid_builtin_call (alloc_stmt)) | |
3782 | return false; | |
3783 | tree alloc_size = gimple_call_arg (alloc_stmt, 0); | |
3784 | tree memset_size = gimple_call_arg (memset_stmt, 2); | |
3785 | ||
3786 | /* Check for overflow. */ | |
47e4ab65 | 3787 | maybe_warn_overflow (memset_stmt, false, memset_size, NULL, false, true); |
ef29b12c MS |
3788 | |
3789 | /* Bail when there is no statement associated with the destination | |
3790 | (the statement may be null even when SI1->ALLOC is not). */ | |
3791 | if (!si1->stmt) | |
3792 | return false; | |
3793 | ||
3794 | /* Avoid optimizing if store is at a variable offset from the beginning | |
3795 | of the allocated object. */ | |
3796 | if (offrng[0] != 0 || offrng[0] != offrng[1]) | |
8b0b334a | 3797 | return false; |
ef29b12c MS |
3798 | |
3799 | /* Bail when the call writes a non-zero value. */ | |
3800 | if (!integer_zerop (gimple_call_arg (memset_stmt, 1))) | |
8b0b334a | 3801 | return false; |
ef29b12c MS |
3802 | |
3803 | /* Let the caller know the memset call cleared the destination. */ | |
3804 | *zero_write = true; | |
3805 | ||
24314386 | 3806 | enum built_in_function code1 = DECL_FUNCTION_CODE (callee1); |
24314386 | 3807 | if (code1 == BUILT_IN_CALLOC) |
ef29b12c | 3808 | /* Not touching alloc_stmt */ ; |
24314386 | 3809 | else if (code1 == BUILT_IN_MALLOC |
ef29b12c | 3810 | && operand_equal_p (memset_size, alloc_size, 0)) |
24314386 | 3811 | { |
ef29b12c MS |
3812 | /* Replace the malloc + memset calls with calloc. */ |
3813 | gimple_stmt_iterator gsi1 = gsi_for_stmt (si1->stmt); | |
24314386 | 3814 | update_gimple_call (&gsi1, builtin_decl_implicit (BUILT_IN_CALLOC), 2, |
ef29b12c | 3815 | alloc_size, build_one_cst (size_type_node)); |
e3f9a279 RS |
3816 | si1->nonzero_chars = build_int_cst (size_type_node, 0); |
3817 | si1->full_string_p = true; | |
20cb2258 | 3818 | si1->stmt = gsi_stmt (gsi1); |
24314386 MG |
3819 | } |
3820 | else | |
8b0b334a | 3821 | return false; |
ef29b12c MS |
3822 | tree lhs = gimple_call_lhs (memset_stmt); |
3823 | unlink_stmt_vdef (memset_stmt); | |
24314386 MG |
3824 | if (lhs) |
3825 | { | |
355fe088 | 3826 | gimple *assign = gimple_build_assign (lhs, ptr); |
47e4ab65 | 3827 | gsi_replace (&m_gsi, assign, false); |
24314386 MG |
3828 | } |
3829 | else | |
3830 | { | |
47e4ab65 | 3831 | gsi_remove (&m_gsi, true); |
ef29b12c | 3832 | release_defs (memset_stmt); |
24314386 MG |
3833 | } |
3834 | ||
8b0b334a | 3835 | return true; |
24314386 MG |
3836 | } |
3837 | ||
b1ecb865 MS |
3838 | /* Return first such statement if RES is used in statements testing its |
3839 | equality to zero, and null otherwise. If EXCLUSIVE is true, return | |
3840 | nonnull if and only RES is used in such expressions exclusively and | |
3841 | in none other. */ | |
36b85e43 | 3842 | |
a7160771 | 3843 | static gimple * |
b1ecb865 | 3844 | use_in_zero_equality (tree res, bool exclusive = true) |
36b85e43 | 3845 | { |
a7160771 MS |
3846 | gimple *first_use = NULL; |
3847 | ||
36b85e43 BS |
3848 | use_operand_p use_p; |
3849 | imm_use_iterator iter; | |
3850 | ||
36b85e43 BS |
3851 | FOR_EACH_IMM_USE_FAST (use_p, iter, res) |
3852 | { | |
a7160771 | 3853 | gimple *use_stmt = USE_STMT (use_p); |
36b85e43 | 3854 | |
a7160771 MS |
3855 | if (is_gimple_debug (use_stmt)) |
3856 | continue; | |
b1ecb865 | 3857 | |
a7160771 | 3858 | if (gimple_code (use_stmt) == GIMPLE_ASSIGN) |
36b85e43 | 3859 | { |
a7160771 MS |
3860 | tree_code code = gimple_assign_rhs_code (use_stmt); |
3861 | if (code == COND_EXPR) | |
3862 | { | |
3863 | tree cond_expr = gimple_assign_rhs1 (use_stmt); | |
3864 | if ((TREE_CODE (cond_expr) != EQ_EXPR | |
3865 | && (TREE_CODE (cond_expr) != NE_EXPR)) | |
3866 | || !integer_zerop (TREE_OPERAND (cond_expr, 1))) | |
b1ecb865 MS |
3867 | { |
3868 | if (exclusive) | |
3869 | return NULL; | |
3870 | continue; | |
3871 | } | |
a7160771 MS |
3872 | } |
3873 | else if (code == EQ_EXPR || code == NE_EXPR) | |
3874 | { | |
3875 | if (!integer_zerop (gimple_assign_rhs2 (use_stmt))) | |
b1ecb865 MS |
3876 | { |
3877 | if (exclusive) | |
3878 | return NULL; | |
3879 | continue; | |
3880 | } | |
a7160771 | 3881 | } |
b1ecb865 | 3882 | else if (exclusive) |
a7160771 | 3883 | return NULL; |
b1ecb865 MS |
3884 | else |
3885 | continue; | |
36b85e43 | 3886 | } |
a7160771 | 3887 | else if (gimple_code (use_stmt) == GIMPLE_COND) |
36b85e43 | 3888 | { |
a7160771 | 3889 | tree_code code = gimple_cond_code (use_stmt); |
36b85e43 | 3890 | if ((code != EQ_EXPR && code != NE_EXPR) |
a7160771 | 3891 | || !integer_zerop (gimple_cond_rhs (use_stmt))) |
b1ecb865 MS |
3892 | { |
3893 | if (exclusive) | |
3894 | return NULL; | |
3895 | continue; | |
3896 | } | |
36b85e43 | 3897 | } |
b1ecb865 MS |
3898 | else if (exclusive) |
3899 | return NULL; | |
36b85e43 | 3900 | else |
b1ecb865 | 3901 | continue; |
a7160771 MS |
3902 | |
3903 | if (!first_use) | |
3904 | first_use = use_stmt; | |
36b85e43 BS |
3905 | } |
3906 | ||
a7160771 MS |
3907 | return first_use; |
3908 | } | |
3909 | ||
3910 | /* Handle a call to memcmp. We try to handle small comparisons by | |
3911 | converting them to load and compare, and replacing the call to memcmp | |
3912 | with a __builtin_memcmp_eq call where possible. | |
3913 | return true when call is transformed, return false otherwise. */ | |
3914 | ||
47e4ab65 AH |
3915 | bool |
3916 | strlen_pass::handle_builtin_memcmp () | |
a7160771 | 3917 | { |
47e4ab65 | 3918 | gcall *stmt = as_a <gcall *> (gsi_stmt (m_gsi)); |
a7160771 MS |
3919 | tree res = gimple_call_lhs (stmt); |
3920 | ||
b1ecb865 | 3921 | if (!res || !use_in_zero_equality (res)) |
a7160771 MS |
3922 | return false; |
3923 | ||
3924 | tree arg1 = gimple_call_arg (stmt, 0); | |
3925 | tree arg2 = gimple_call_arg (stmt, 1); | |
3926 | tree len = gimple_call_arg (stmt, 2); | |
3927 | unsigned HOST_WIDE_INT leni; | |
3928 | ||
36b85e43 BS |
3929 | if (tree_fits_uhwi_p (len) |
3930 | && (leni = tree_to_uhwi (len)) <= GET_MODE_SIZE (word_mode) | |
146ec50f | 3931 | && pow2p_hwi (leni)) |
36b85e43 BS |
3932 | { |
3933 | leni *= CHAR_TYPE_SIZE; | |
3934 | unsigned align1 = get_pointer_alignment (arg1); | |
3935 | unsigned align2 = get_pointer_alignment (arg2); | |
3936 | unsigned align = MIN (align1, align2); | |
fffbab82 RS |
3937 | scalar_int_mode mode; |
3938 | if (int_mode_for_size (leni, 1).exists (&mode) | |
e0bd6c9f | 3939 | && (align >= leni || !targetm.slow_unaligned_access (mode, align))) |
36b85e43 | 3940 | { |
a7160771 | 3941 | location_t loc = gimple_location (stmt); |
36b85e43 BS |
3942 | tree type, off; |
3943 | type = build_nonstandard_integer_type (leni, 1); | |
73a699ae | 3944 | gcc_assert (known_eq (GET_MODE_BITSIZE (TYPE_MODE (type)), leni)); |
36b85e43 BS |
3945 | tree ptrtype = build_pointer_type_for_mode (char_type_node, |
3946 | ptr_mode, true); | |
3947 | off = build_int_cst (ptrtype, 0); | |
3948 | arg1 = build2_loc (loc, MEM_REF, type, arg1, off); | |
3949 | arg2 = build2_loc (loc, MEM_REF, type, arg2, off); | |
3950 | tree tem1 = fold_const_aggregate_ref (arg1); | |
3951 | if (tem1) | |
3952 | arg1 = tem1; | |
3953 | tree tem2 = fold_const_aggregate_ref (arg2); | |
3954 | if (tem2) | |
3955 | arg2 = tem2; | |
3956 | res = fold_convert_loc (loc, TREE_TYPE (res), | |
3957 | fold_build2_loc (loc, NE_EXPR, | |
3958 | boolean_type_node, | |
3959 | arg1, arg2)); | |
47e4ab65 | 3960 | gimplify_and_update_call_from_tree (&m_gsi, res); |
8b0b334a | 3961 | return true; |
36b85e43 BS |
3962 | } |
3963 | } | |
3964 | ||
a7160771 | 3965 | gimple_call_set_fndecl (stmt, builtin_decl_explicit (BUILT_IN_MEMCMP_EQ)); |
8b0b334a QZ |
3966 | return true; |
3967 | } | |
3968 | ||
e7868dc6 MS |
3969 | /* Given strinfo IDX for ARG, sets LENRNG[] to the range of lengths |
3970 | of the string(s) referenced by ARG if it can be determined. | |
3971 | If the length cannot be determined, sets *SIZE to the size of | |
a7160771 | 3972 | the array the string is stored in, if any. If no such array is |
e7868dc6 MS |
3973 | known, sets *SIZE to -1. When the strings are nul-terminated sets |
3974 | *NULTERM to true, otherwise to false. When nonnull uses RVALS to | |
3975 | determine range information. Returns true on success. */ | |
8b0b334a | 3976 | |
47e4ab65 AH |
3977 | bool |
3978 | strlen_pass::get_len_or_size (gimple *stmt, tree arg, int idx, | |
3979 | unsigned HOST_WIDE_INT lenrng[2], | |
3980 | unsigned HOST_WIDE_INT *size, bool *nulterm) | |
8b0b334a | 3981 | { |
e7868dc6 | 3982 | /* Invalidate. */ |
a7160771 | 3983 | *size = HOST_WIDE_INT_M1U; |
8b0b334a | 3984 | |
a7160771 | 3985 | if (idx < 0) |
8b0b334a | 3986 | { |
a7160771 MS |
3987 | /* IDX is the inverted constant string length. */ |
3988 | lenrng[0] = ~idx; | |
3989 | lenrng[1] = lenrng[0]; | |
3990 | *nulterm = true; | |
e7868dc6 | 3991 | return true; |
8b0b334a | 3992 | } |
e7868dc6 MS |
3993 | |
3994 | /* Set so that both LEN and ~LEN are invalid lengths, i.e., maximum | |
3995 | possible length + 1. */ | |
3996 | lenrng[0] = lenrng[1] = HOST_WIDE_INT_MAX; | |
3997 | ||
3998 | if (strinfo *si = idx ? get_strinfo (idx) : NULL) | |
21722777 | 3999 | { |
e7868dc6 | 4000 | /* FIXME: Handle all this in_range_strlen_dynamic. */ |
a7160771 | 4001 | if (!si->nonzero_chars) |
e7868dc6 | 4002 | ; |
a7160771 MS |
4003 | else if (tree_fits_uhwi_p (si->nonzero_chars)) |
4004 | { | |
4005 | lenrng[0] = tree_to_uhwi (si->nonzero_chars); | |
4006 | *nulterm = si->full_string_p; | |
4007 | /* Set the upper bound only if the string is known to be | |
4008 | nul-terminated, otherwise leave it at maximum + 1. */ | |
4009 | if (*nulterm) | |
4010 | lenrng[1] = lenrng[0]; | |
4011 | } | |
4012 | else if (TREE_CODE (si->nonzero_chars) == SSA_NAME) | |
4013 | { | |
45f4e2b0 AH |
4014 | value_range r; |
4015 | get_range_query (cfun)->range_of_expr (r, si->nonzero_chars); | |
4016 | if (r.kind () == VR_RANGE) | |
a7160771 | 4017 | { |
45f4e2b0 AH |
4018 | lenrng[0] = r.lower_bound ().to_uhwi (); |
4019 | lenrng[1] = r.upper_bound ().to_uhwi (); | |
a7160771 MS |
4020 | *nulterm = si->full_string_p; |
4021 | } | |
4022 | } | |
a7160771 | 4023 | } |
8b0b334a | 4024 | |
e7868dc6 MS |
4025 | if (lenrng[0] != HOST_WIDE_INT_MAX) |
4026 | return true; | |
4027 | ||
4028 | /* Compute the minimum and maximum real or possible lengths. */ | |
4029 | c_strlen_data lendata = { }; | |
4030 | /* Set MAXBOUND to an arbitrary non-null non-integer node as a request | |
4031 | to have it set to the length of the longest string in a PHI. */ | |
4032 | lendata.maxbound = arg; | |
47e4ab65 | 4033 | get_range_strlen_dynamic (arg, stmt, &lendata, ptr_qry.rvals); |
e7868dc6 MS |
4034 | |
4035 | unsigned HOST_WIDE_INT maxbound = HOST_WIDE_INT_M1U; | |
4036 | if (tree_fits_uhwi_p (lendata.maxbound) | |
4037 | && !integer_all_onesp (lendata.maxbound)) | |
4038 | maxbound = tree_to_uhwi (lendata.maxbound); | |
4039 | ||
4040 | if (tree_fits_uhwi_p (lendata.minlen) && tree_fits_uhwi_p (lendata.maxlen)) | |
a7160771 | 4041 | { |
e7868dc6 MS |
4042 | unsigned HOST_WIDE_INT minlen = tree_to_uhwi (lendata.minlen); |
4043 | unsigned HOST_WIDE_INT maxlen = tree_to_uhwi (lendata.maxlen); | |
4044 | ||
4045 | /* The longest string in this data model. */ | |
4046 | const unsigned HOST_WIDE_INT lenmax | |
4047 | = tree_to_uhwi (max_object_size ()) - 2; | |
4048 | ||
4049 | if (maxbound == HOST_WIDE_INT_M1U) | |
21722777 | 4050 | { |
e7868dc6 MS |
4051 | lenrng[0] = minlen; |
4052 | lenrng[1] = maxlen; | |
4053 | *nulterm = minlen == maxlen; | |
8b0b334a | 4054 | } |
e7868dc6 | 4055 | else if (maxlen < lenmax) |
8b0b334a | 4056 | { |
e7868dc6 | 4057 | *size = maxbound + 1; |
a7160771 | 4058 | *nulterm = false; |
8b0b334a | 4059 | } |
e7868dc6 MS |
4060 | else |
4061 | return false; | |
4062 | ||
4063 | return true; | |
8b0b334a | 4064 | } |
21722777 | 4065 | |
e7868dc6 MS |
4066 | if (maxbound != HOST_WIDE_INT_M1U |
4067 | && lendata.maxlen | |
4068 | && !integer_all_onesp (lendata.maxlen)) | |
4069 | { | |
4070 | /* Set *SIZE to LENDATA.MAXBOUND which is a conservative estimate | |
4071 | of the longest string based on the sizes of the arrays referenced | |
4072 | by ARG. */ | |
4073 | *size = maxbound + 1; | |
4074 | *nulterm = false; | |
4075 | return true; | |
4076 | } | |
4077 | ||
4078 | return false; | |
a7160771 MS |
4079 | } |
4080 | ||
4081 | /* If IDX1 and IDX2 refer to strings A and B of unequal lengths, return | |
4082 | the result of 0 == strncmp (A, B, BOUND) (which is the same as strcmp | |
4083 | for a sufficiently large BOUND). If the result is based on the length | |
4084 | of one string being greater than the longest string that would fit in | |
4085 | the array pointer to by the argument, set *PLEN and *PSIZE to | |
4086 | the corresponding length (or its complement when the string is known | |
4087 | to be at least as long and need not be nul-terminated) and size. | |
4088 | Otherwise return null. */ | |
4089 | ||
47e4ab65 AH |
4090 | tree |
4091 | strlen_pass::strxcmp_eqz_result (gimple *stmt, tree arg1, int idx1, | |
4092 | tree arg2, int idx2, | |
4093 | unsigned HOST_WIDE_INT bound, | |
4094 | unsigned HOST_WIDE_INT len[2], | |
4095 | unsigned HOST_WIDE_INT *psize) | |
a7160771 MS |
4096 | { |
4097 | /* Determine the range the length of each string is in and whether it's | |
4098 | known to be nul-terminated, or the size of the array it's stored in. */ | |
4099 | bool nul1, nul2; | |
4100 | unsigned HOST_WIDE_INT siz1, siz2; | |
4101 | unsigned HOST_WIDE_INT len1rng[2], len2rng[2]; | |
47e4ab65 AH |
4102 | if (!get_len_or_size (stmt, arg1, idx1, len1rng, &siz1, &nul1) |
4103 | || !get_len_or_size (stmt, arg2, idx2, len2rng, &siz2, &nul2)) | |
a7160771 MS |
4104 | return NULL_TREE; |
4105 | ||
4106 | /* BOUND is set to HWI_M1U for strcmp and less to strncmp, and LENiRNG | |
4107 | to HWI_MAX when invalid. Adjust the length of each string to consider | |
4108 | to be no more than BOUND. */ | |
4109 | if (len1rng[0] < HOST_WIDE_INT_MAX && len1rng[0] > bound) | |
4110 | len1rng[0] = bound; | |
4111 | if (len1rng[1] < HOST_WIDE_INT_MAX && len1rng[1] > bound) | |
4112 | len1rng[1] = bound; | |
4113 | if (len2rng[0] < HOST_WIDE_INT_MAX && len2rng[0] > bound) | |
4114 | len2rng[0] = bound; | |
4115 | if (len2rng[1] < HOST_WIDE_INT_MAX && len2rng[1] > bound) | |
4116 | len2rng[1] = bound; | |
4117 | ||
4118 | /* Two empty strings are equal. */ | |
4119 | if (len1rng[1] == 0 && len2rng[1] == 0) | |
4120 | return integer_one_node; | |
4121 | ||
4122 | /* The strings are definitely unequal when the lower bound of the length | |
4123 | of one of them is greater than the length of the longest string that | |
4124 | would fit into the other array. */ | |
4125 | if (len1rng[0] == HOST_WIDE_INT_MAX | |
4126 | && len2rng[0] != HOST_WIDE_INT_MAX | |
4127 | && ((len2rng[0] < bound && len2rng[0] >= siz1) | |
4128 | || len2rng[0] > siz1)) | |
4129 | { | |
4130 | *psize = siz1; | |
4131 | len[0] = len1rng[0]; | |
4132 | /* Set LEN[0] to the lower bound of ARG1's length when it's | |
4133 | nul-terminated or to the complement of its minimum length | |
4134 | otherwise, */ | |
4135 | len[1] = nul2 ? len2rng[0] : ~len2rng[0]; | |
4136 | return integer_zero_node; | |
4137 | } | |
4138 | ||
4139 | if (len2rng[0] == HOST_WIDE_INT_MAX | |
4140 | && len1rng[0] != HOST_WIDE_INT_MAX | |
4141 | && ((len1rng[0] < bound && len1rng[0] >= siz2) | |
4142 | || len1rng[0] > siz2)) | |
4143 | { | |
4144 | *psize = siz2; | |
4145 | len[0] = nul1 ? len1rng[0] : ~len1rng[0]; | |
4146 | len[1] = len2rng[0]; | |
4147 | return integer_zero_node; | |
4148 | } | |
4149 | ||
4150 | /* The strings are also definitely unequal when their lengths are unequal | |
4151 | and at least one is nul-terminated. */ | |
4152 | if (len1rng[0] != HOST_WIDE_INT_MAX | |
4153 | && len2rng[0] != HOST_WIDE_INT_MAX | |
4154 | && ((len1rng[1] < len2rng[0] && nul1) | |
4155 | || (len2rng[1] < len1rng[0] && nul2))) | |
4156 | { | |
4157 | if (bound <= len1rng[0] || bound <= len2rng[0]) | |
4158 | *psize = bound; | |
4159 | else | |
4160 | *psize = HOST_WIDE_INT_M1U; | |
4161 | ||
4162 | len[0] = len1rng[0]; | |
4163 | len[1] = len2rng[0]; | |
4164 | return integer_zero_node; | |
8b0b334a QZ |
4165 | } |
4166 | ||
a7160771 MS |
4167 | /* The string lengths may be equal or unequal. Even when equal and |
4168 | both strings nul-terminated, without the string contents there's | |
4169 | no way to determine whether they are equal. */ | |
4170 | return NULL_TREE; | |
4171 | } | |
4172 | ||
4173 | /* Diagnose pointless calls to strcmp or strncmp STMT with string | |
4174 | arguments of lengths LEN or size SIZ and (for strncmp) BOUND, | |
4175 | whose result is used in equality expressions that evaluate to | |
4176 | a constant due to one argument being longer than the size of | |
4177 | the other. */ | |
21722777 | 4178 | |
a7160771 MS |
4179 | static void |
4180 | maybe_warn_pointless_strcmp (gimple *stmt, HOST_WIDE_INT bound, | |
4181 | unsigned HOST_WIDE_INT len[2], | |
4182 | unsigned HOST_WIDE_INT siz) | |
4183 | { | |
27c14dbc | 4184 | tree lhs = gimple_call_lhs (stmt); |
b1ecb865 | 4185 | gimple *use = use_in_zero_equality (lhs, /* exclusive = */ false); |
a7160771 MS |
4186 | if (!use) |
4187 | return; | |
4188 | ||
4189 | bool at_least = false; | |
4190 | ||
4191 | /* Excessive LEN[i] indicates a lower bound. */ | |
4192 | if (len[0] > HOST_WIDE_INT_MAX) | |
8b0b334a | 4193 | { |
a7160771 MS |
4194 | at_least = true; |
4195 | len[0] = ~len[0]; | |
21722777 | 4196 | } |
a7160771 MS |
4197 | |
4198 | if (len[1] > HOST_WIDE_INT_MAX) | |
8b0b334a | 4199 | { |
a7160771 MS |
4200 | at_least = true; |
4201 | len[1] = ~len[1]; | |
21722777 | 4202 | } |
8b0b334a | 4203 | |
a7160771 | 4204 | unsigned HOST_WIDE_INT minlen = MIN (len[0], len[1]); |
21722777 | 4205 | |
a7160771 MS |
4206 | /* FIXME: Include a note pointing to the declaration of the smaller |
4207 | array. */ | |
55ace4d1 | 4208 | location_t stmt_loc = gimple_or_expr_nonartificial_location (stmt, lhs); |
27c14dbc | 4209 | |
a7160771 MS |
4210 | tree callee = gimple_call_fndecl (stmt); |
4211 | bool warned = false; | |
4212 | if (siz <= minlen && bound == -1) | |
4213 | warned = warning_at (stmt_loc, OPT_Wstring_compare, | |
4214 | (at_least | |
6d3bab5d | 4215 | ? G_("%qD of a string of length %wu or more and " |
a7160771 | 4216 | "an array of size %wu evaluates to nonzero") |
6d3bab5d | 4217 | : G_("%qD of a string of length %wu and an array " |
a7160771 | 4218 | "of size %wu evaluates to nonzero")), |
6d3bab5d | 4219 | callee, minlen, siz); |
a7160771 MS |
4220 | else if (!at_least && siz <= HOST_WIDE_INT_MAX) |
4221 | { | |
4222 | if (len[0] != HOST_WIDE_INT_MAX && len[1] != HOST_WIDE_INT_MAX) | |
4223 | warned = warning_at (stmt_loc, OPT_Wstring_compare, | |
6d3bab5d | 4224 | "%qD of strings of length %wu and %wu " |
a7160771 | 4225 | "and bound of %wu evaluates to nonzero", |
6d3bab5d | 4226 | callee, len[0], len[1], bound); |
a7160771 MS |
4227 | else |
4228 | warned = warning_at (stmt_loc, OPT_Wstring_compare, | |
6d3bab5d | 4229 | "%qD of a string of length %wu, an array " |
a7160771 MS |
4230 | "of size %wu and bound of %wu evaluates to " |
4231 | "nonzero", | |
6d3bab5d | 4232 | callee, minlen, siz, bound); |
a7160771 MS |
4233 | } |
4234 | ||
b1ecb865 MS |
4235 | if (!warned) |
4236 | return; | |
4237 | ||
4238 | location_t use_loc = gimple_location (use); | |
4239 | if (LOCATION_LINE (stmt_loc) != LOCATION_LINE (use_loc)) | |
4240 | inform (use_loc, "in this expression"); | |
a7160771 | 4241 | } |
8b0b334a | 4242 | |
21722777 | 4243 | |
a7160771 MS |
4244 | /* Optimize a call to strcmp or strncmp either by folding it to a constant |
4245 | when possible or by transforming the latter to the former. Warn about | |
4246 | calls where the length of one argument is greater than the size of | |
4247 | the array to which the other argument points if the latter's length | |
4248 | is not known. Return true when the call has been transformed into | |
4249 | another and false otherwise. */ | |
4250 | ||
47e4ab65 AH |
4251 | bool |
4252 | strlen_pass::handle_builtin_string_cmp () | |
a7160771 | 4253 | { |
47e4ab65 | 4254 | gcall *stmt = as_a <gcall *> (gsi_stmt (m_gsi)); |
a7160771 | 4255 | tree lhs = gimple_call_lhs (stmt); |
8b0b334a | 4256 | |
a7160771 | 4257 | if (!lhs) |
8b0b334a QZ |
4258 | return false; |
4259 | ||
a7160771 MS |
4260 | tree arg1 = gimple_call_arg (stmt, 0); |
4261 | tree arg2 = gimple_call_arg (stmt, 1); | |
6b8b9596 AH |
4262 | int idx1 = get_stridx (arg1, stmt); |
4263 | int idx2 = get_stridx (arg2, stmt); | |
8b0b334a | 4264 | |
700d4cb0 | 4265 | /* For strncmp set to the value of the third argument if known. */ |
a7160771 | 4266 | HOST_WIDE_INT bound = -1; |
b5338fb3 | 4267 | tree len = NULL_TREE; |
a7160771 MS |
4268 | /* Extract the strncmp bound. */ |
4269 | if (gimple_call_num_args (stmt) == 3) | |
8b0b334a | 4270 | { |
b5338fb3 | 4271 | len = gimple_call_arg (stmt, 2); |
a7160771 MS |
4272 | if (tree_fits_shwi_p (len)) |
4273 | bound = tree_to_shwi (len); | |
4274 | ||
4275 | /* If the bound argument is NOT known, do nothing. */ | |
4276 | if (bound < 0) | |
8b0b334a | 4277 | return false; |
8b0b334a | 4278 | } |
a7160771 | 4279 | |
b5338fb3 MS |
4280 | /* Avoid folding if either argument is not a nul-terminated array. |
4281 | Defer warning until later. */ | |
4282 | if (!check_nul_terminated_array (NULL_TREE, arg1, len) | |
4283 | || !check_nul_terminated_array (NULL_TREE, arg2, len)) | |
4284 | return false; | |
4285 | ||
a7160771 MS |
4286 | { |
4287 | /* Set to the length of one argument (or its complement if it's | |
4288 | the lower bound of a range) and the size of the array storing | |
4289 | the other if the result is based on the former being equal to | |
4290 | or greater than the latter. */ | |
4291 | unsigned HOST_WIDE_INT len[2] = { HOST_WIDE_INT_MAX, HOST_WIDE_INT_MAX }; | |
4292 | unsigned HOST_WIDE_INT siz = HOST_WIDE_INT_M1U; | |
4293 | ||
4294 | /* Try to determine if the two strings are either definitely equal | |
4295 | or definitely unequal and if so, either fold the result to zero | |
4296 | (when equal) or set the range of the result to ~[0, 0] otherwise. */ | |
f5299992 | 4297 | if (tree eqz = strxcmp_eqz_result (stmt, arg1, idx1, arg2, idx2, bound, |
47e4ab65 | 4298 | len, &siz)) |
a7160771 MS |
4299 | { |
4300 | if (integer_zerop (eqz)) | |
4301 | { | |
4302 | maybe_warn_pointless_strcmp (stmt, bound, len, siz); | |
4303 | ||
4304 | /* When the lengths of the first two string arguments are | |
4305 | known to be unequal set the range of the result to non-zero. | |
4306 | This allows the call to be eliminated if its result is only | |
4307 | used in tests for equality to zero. */ | |
4308 | wide_int zero = wi::zero (TYPE_PRECISION (TREE_TYPE (lhs))); | |
4309 | set_range_info (lhs, VR_ANTI_RANGE, zero, zero); | |
4310 | return false; | |
4311 | } | |
4312 | /* When the two strings are definitely equal (such as when they | |
4313 | are both empty) fold the call to the constant result. */ | |
47e4ab65 | 4314 | replace_call_with_value (&m_gsi, integer_zero_node); |
a7160771 MS |
4315 | return true; |
4316 | } | |
4317 | } | |
4318 | ||
4319 | /* Return if nothing is known about the strings pointed to by ARG1 | |
4320 | and ARG2. */ | |
4321 | if (idx1 == 0 && idx2 == 0) | |
4322 | return false; | |
4323 | ||
4324 | /* Determine either the length or the size of each of the strings, | |
4325 | whichever is available. */ | |
4326 | HOST_WIDE_INT cstlen1 = -1, cstlen2 = -1; | |
4327 | HOST_WIDE_INT arysiz1 = -1, arysiz2 = -1; | |
4328 | ||
e7868dc6 MS |
4329 | { |
4330 | unsigned HOST_WIDE_INT len1rng[2], len2rng[2]; | |
4331 | unsigned HOST_WIDE_INT arsz1, arsz2; | |
4332 | bool nulterm[2]; | |
4333 | ||
47e4ab65 AH |
4334 | if (!get_len_or_size (stmt, arg1, idx1, len1rng, &arsz1, nulterm) |
4335 | || !get_len_or_size (stmt, arg2, idx2, len2rng, &arsz2, nulterm + 1)) | |
e7868dc6 MS |
4336 | return false; |
4337 | ||
4338 | if (len1rng[0] == len1rng[1] && len1rng[0] < HOST_WIDE_INT_MAX) | |
4339 | cstlen1 = len1rng[0]; | |
4340 | else if (arsz1 < HOST_WIDE_INT_M1U) | |
4341 | arysiz1 = arsz1; | |
4342 | ||
4343 | if (len2rng[0] == len2rng[1] && len2rng[0] < HOST_WIDE_INT_MAX) | |
4344 | cstlen2 = len2rng[0]; | |
4345 | else if (arsz2 < HOST_WIDE_INT_M1U) | |
4346 | arysiz2 = arsz2; | |
4347 | } | |
a7160771 MS |
4348 | |
4349 | /* Bail if neither the string length nor the size of the array | |
4350 | it is stored in can be determined. */ | |
e7868dc6 MS |
4351 | if ((cstlen1 < 0 && arysiz1 < 0) |
4352 | || (cstlen2 < 0 && arysiz2 < 0) | |
4353 | || (cstlen1 < 0 && cstlen2 < 0)) | |
9c233ad0 MS |
4354 | return false; |
4355 | ||
4356 | if (cstlen1 >= 0) | |
4357 | ++cstlen1; | |
4358 | if (cstlen2 >= 0) | |
4359 | ++cstlen2; | |
4360 | ||
a7160771 | 4361 | /* The exact number of characters to compare. */ |
f982a6ec JJ |
4362 | HOST_WIDE_INT cmpsiz; |
4363 | if (cstlen1 >= 0 && cstlen2 >= 0) | |
4364 | cmpsiz = MIN (cstlen1, cstlen2); | |
4365 | else if (cstlen1 >= 0) | |
4366 | cmpsiz = cstlen1; | |
4367 | else | |
4368 | cmpsiz = cstlen2; | |
4369 | if (bound >= 0) | |
4370 | cmpsiz = MIN (cmpsiz, bound); | |
a7160771 MS |
4371 | /* The size of the array in which the unknown string is stored. */ |
4372 | HOST_WIDE_INT varsiz = arysiz1 < 0 ? arysiz2 : arysiz1; | |
4373 | ||
b1ecb865 | 4374 | if ((varsiz < 0 || cmpsiz < varsiz) && use_in_zero_equality (lhs)) |
a7160771 MS |
4375 | { |
4376 | /* If the known length is less than the size of the other array | |
4377 | and the strcmp result is only used to test equality to zero, | |
4378 | transform the call to the equivalent _eq call. */ | |
4379 | if (tree fn = builtin_decl_implicit (bound < 0 ? BUILT_IN_STRCMP_EQ | |
4380 | : BUILT_IN_STRNCMP_EQ)) | |
4381 | { | |
4382 | tree n = build_int_cst (size_type_node, cmpsiz); | |
47e4ab65 | 4383 | update_gimple_call (&m_gsi, fn, 3, arg1, arg2, n); |
a7160771 MS |
4384 | return true; |
4385 | } | |
4386 | } | |
4387 | ||
4388 | return false; | |
36b85e43 BS |
4389 | } |
4390 | ||
8b57bfeb JJ |
4391 | /* Handle a POINTER_PLUS_EXPR statement. |
4392 | For p = "abcd" + 2; compute associated length, or if | |
4393 | p = q + off is pointing to a '\0' character of a string, call | |
4394 | zero_length_string on it. */ | |
4395 | ||
47e4ab65 AH |
4396 | void |
4397 | strlen_pass::handle_pointer_plus () | |
8b57bfeb | 4398 | { |
47e4ab65 | 4399 | gimple *stmt = gsi_stmt (m_gsi); |
8b57bfeb | 4400 | tree lhs = gimple_assign_lhs (stmt), off; |
6b8b9596 | 4401 | int idx = get_stridx (gimple_assign_rhs1 (stmt), stmt); |
526ceb68 | 4402 | strinfo *si, *zsi; |
8b57bfeb JJ |
4403 | |
4404 | if (idx == 0) | |
4405 | return; | |
4406 | ||
4407 | if (idx < 0) | |
4408 | { | |
4409 | tree off = gimple_assign_rhs2 (stmt); | |
cc269bb6 | 4410 | if (tree_fits_uhwi_p (off) |
7d362f6c | 4411 | && tree_to_uhwi (off) <= (unsigned HOST_WIDE_INT) ~idx) |
9771b263 | 4412 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] |
ae7e9ddd | 4413 | = ~(~idx - (int) tree_to_uhwi (off)); |
8b57bfeb JJ |
4414 | return; |
4415 | } | |
4416 | ||
4417 | si = get_strinfo (idx); | |
e3f9a279 | 4418 | if (si == NULL || si->nonzero_chars == NULL_TREE) |
8b57bfeb JJ |
4419 | return; |
4420 | ||
4421 | off = gimple_assign_rhs2 (stmt); | |
4422 | zsi = NULL; | |
e3f9a279 | 4423 | if (si->full_string_p && operand_equal_p (si->nonzero_chars, off, 0)) |
8b57bfeb JJ |
4424 | zsi = zero_length_string (lhs, si); |
4425 | else if (TREE_CODE (off) == SSA_NAME) | |
4426 | { | |
355fe088 | 4427 | gimple *def_stmt = SSA_NAME_DEF_STMT (off); |
8b57bfeb | 4428 | if (gimple_assign_single_p (def_stmt) |
e3f9a279 RS |
4429 | && si->full_string_p |
4430 | && operand_equal_p (si->nonzero_chars, | |
4431 | gimple_assign_rhs1 (def_stmt), 0)) | |
8b57bfeb JJ |
4432 | zsi = zero_length_string (lhs, si); |
4433 | } | |
4434 | if (zsi != NULL | |
4435 | && si->endptr != NULL_TREE | |
4436 | && si->endptr != lhs | |
4437 | && TREE_CODE (si->endptr) == SSA_NAME) | |
4438 | { | |
4439 | enum tree_code rhs_code | |
4440 | = useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (si->endptr)) | |
4441 | ? SSA_NAME : NOP_EXPR; | |
47e4ab65 AH |
4442 | gimple_assign_set_rhs_with_ops (&m_gsi, rhs_code, si->endptr); |
4443 | gcc_assert (gsi_stmt (m_gsi) == stmt); | |
8b57bfeb JJ |
4444 | update_stmt (stmt); |
4445 | } | |
4446 | } | |
4447 | ||
f0500db3 MS |
4448 | /* Set LENRANGE to the number of nonzero bytes for a store of TYPE and |
4449 | clear all flags. Return true on success and false on failure. */ | |
4450 | ||
4451 | static bool | |
4452 | nonzero_bytes_for_type (tree type, unsigned lenrange[3], | |
4453 | bool *nulterm, bool *allnul, bool *allnonnul) | |
4454 | { | |
4455 | /* Use the size of the type of the expression as the size of the store, | |
4456 | and set the upper bound of the length range to that of the size. | |
4457 | Nothing is known about the contents so clear all flags. */ | |
4458 | tree typesize = TYPE_SIZE_UNIT (type); | |
4459 | if (!type) | |
4460 | return false; | |
4461 | ||
4462 | if (!tree_fits_uhwi_p (typesize)) | |
4463 | return false; | |
4464 | ||
4465 | unsigned HOST_WIDE_INT sz = tree_to_uhwi (typesize); | |
4466 | if (sz > UINT_MAX) | |
4467 | return false; | |
4468 | ||
4469 | lenrange[2] = sz; | |
4470 | lenrange[1] = lenrange[2] ? lenrange[2] - 1 : 0; | |
4471 | lenrange[0] = 0; | |
4472 | *nulterm = false; | |
4473 | *allnul = false; | |
4474 | *allnonnul = false; | |
4475 | return true; | |
4476 | } | |
4477 | ||
f0500db3 MS |
4478 | /* Recursively determine the minimum and maximum number of leading nonzero |
4479 | bytes in the representation of EXP and set LENRANGE[0] and LENRANGE[1] | |
1e9369c5 MS |
4480 | to each. |
4481 | Sets LENRANGE[2] to the total size of the access (which may be less | |
4482 | than LENRANGE[1] when what's being referenced by EXP is a pointer | |
4483 | rather than an array). | |
f0500db3 MS |
4484 | Sets *NULTERM if the representation contains a zero byte, sets *ALLNUL |
4485 | if all the bytes are zero, and *ALLNONNUL is all are nonzero. | |
7c3ed632 | 4486 | OFFSET and NBYTES are the offset into the representation and |
1e9369c5 MS |
4487 | the size of the access to it determined from an ADDR_EXPR (i.e., |
4488 | a pointer) or MEM_REF or zero for other expressions. | |
ef29b12c MS |
4489 | Uses RVALS to determine range information. |
4490 | Avoids recursing deeper than the limits in SNLIM allow. | |
7c3ed632 | 4491 | Returns true on success and false otherwise. */ |
b631bdb3 | 4492 | |
47e4ab65 | 4493 | bool |
6b8b9596 | 4494 | strlen_pass::count_nonzero_bytes (tree exp, gimple *stmt, |
47e4ab65 AH |
4495 | unsigned HOST_WIDE_INT offset, |
4496 | unsigned HOST_WIDE_INT nbytes, | |
4497 | unsigned lenrange[3], bool *nulterm, | |
4498 | bool *allnul, bool *allnonnul, | |
4499 | ssa_name_limit_t &snlim) | |
65f2d1ee | 4500 | { |
b631bdb3 | 4501 | if (TREE_CODE (exp) == SSA_NAME) |
aca8570e | 4502 | { |
27c14dbc | 4503 | /* Handle non-zero single-character stores specially. */ |
b631bdb3 MS |
4504 | tree type = TREE_TYPE (exp); |
4505 | if (TREE_CODE (type) == INTEGER_TYPE | |
4506 | && TYPE_MODE (type) == TYPE_MODE (char_type_node) | |
daa94de2 MS |
4507 | && TYPE_PRECISION (type) == TYPE_PRECISION (char_type_node) |
4508 | && tree_expr_nonzero_p (exp)) | |
4509 | { | |
4510 | /* If the character EXP is known to be non-zero (even if its | |
4511 | exact value is not known) recurse once to set the range | |
4512 | for an arbitrary constant. */ | |
4513 | exp = build_int_cst (type, 1); | |
6b8b9596 AH |
4514 | return count_nonzero_bytes (exp, stmt, |
4515 | offset, 1, lenrange, | |
47e4ab65 | 4516 | nulterm, allnul, allnonnul, snlim); |
aca8570e MS |
4517 | } |
4518 | ||
b631bdb3 | 4519 | gimple *stmt = SSA_NAME_DEF_STMT (exp); |
daa94de2 | 4520 | if (gimple_assign_single_p (stmt)) |
b631bdb3 | 4521 | { |
daa94de2 | 4522 | exp = gimple_assign_rhs1 (stmt); |
f0500db3 MS |
4523 | if (!DECL_P (exp) |
4524 | && TREE_CODE (exp) != CONSTRUCTOR | |
4525 | && TREE_CODE (exp) != MEM_REF) | |
b631bdb3 | 4526 | return false; |
f0500db3 | 4527 | /* Handle DECLs, CONSTRUCTOR and MEM_REF below. */ |
b631bdb3 | 4528 | } |
daa94de2 MS |
4529 | else if (gimple_code (stmt) == GIMPLE_PHI) |
4530 | { | |
4531 | /* Avoid processing an SSA_NAME that has already been visited | |
4532 | or if an SSA_NAME limit has been reached. Indicate success | |
4533 | if the former and failure if the latter. */ | |
eafe8ee7 | 4534 | if (int res = snlim.next_phi (exp)) |
daa94de2 MS |
4535 | return res > 0; |
4536 | ||
4537 | /* Determine the minimum and maximum from the PHI arguments. */ | |
4538 | unsigned int n = gimple_phi_num_args (stmt); | |
4539 | for (unsigned i = 0; i != n; i++) | |
4540 | { | |
4541 | tree def = gimple_phi_arg_def (stmt, i); | |
6b8b9596 AH |
4542 | if (!count_nonzero_bytes (def, stmt, |
4543 | offset, nbytes, lenrange, nulterm, | |
47e4ab65 | 4544 | allnul, allnonnul, snlim)) |
daa94de2 MS |
4545 | return false; |
4546 | } | |
b631bdb3 | 4547 | |
daa94de2 MS |
4548 | return true; |
4549 | } | |
aca8570e MS |
4550 | } |
4551 | ||
f0500db3 MS |
4552 | if (TREE_CODE (exp) == CONSTRUCTOR) |
4553 | { | |
4554 | if (nbytes) | |
4555 | /* If NBYTES has already been determined by an outer MEM_REF | |
4556 | fail rather than overwriting it (this shouldn't happen). */ | |
4557 | return false; | |
4558 | ||
4559 | tree type = TREE_TYPE (exp); | |
4560 | tree size = TYPE_SIZE_UNIT (type); | |
4561 | if (!size || !tree_fits_uhwi_p (size)) | |
4562 | return false; | |
4563 | ||
4564 | unsigned HOST_WIDE_INT byte_size = tree_to_uhwi (size); | |
4565 | if (byte_size < offset) | |
4566 | return false; | |
4567 | ||
4568 | nbytes = byte_size - offset; | |
4569 | } | |
4570 | ||
b631bdb3 | 4571 | if (TREE_CODE (exp) == MEM_REF) |
65f2d1ee | 4572 | { |
7c3ed632 MS |
4573 | if (nbytes) |
4574 | return false; | |
4575 | ||
b631bdb3 | 4576 | tree arg = TREE_OPERAND (exp, 0); |
b631bdb3 | 4577 | tree off = TREE_OPERAND (exp, 1); |
34fcf41e | 4578 | |
a9a437ff | 4579 | if (TREE_CODE (off) != INTEGER_CST || !tree_fits_uhwi_p (off)) |
b631bdb3 MS |
4580 | return false; |
4581 | ||
34fcf41e MS |
4582 | unsigned HOST_WIDE_INT wioff = tree_to_uhwi (off); |
4583 | if (INT_MAX < wioff) | |
4584 | return false; | |
4585 | ||
4586 | offset += wioff; | |
b631bdb3 MS |
4587 | if (INT_MAX < offset) |
4588 | return false; | |
4589 | ||
4590 | /* The size of the MEM_REF access determines the number of bytes. */ | |
4591 | tree type = TREE_TYPE (exp); | |
0186d373 RS |
4592 | tree typesize = TYPE_SIZE_UNIT (type); |
4593 | if (!typesize || !tree_fits_uhwi_p (typesize)) | |
34fcf41e | 4594 | return false; |
0186d373 | 4595 | nbytes = tree_to_uhwi (typesize); |
a9a437ff JJ |
4596 | if (!nbytes) |
4597 | return false; | |
b631bdb3 | 4598 | |
34fcf41e | 4599 | /* Handle MEM_REF = SSA_NAME types of assignments. */ |
6b8b9596 AH |
4600 | return count_nonzero_bytes_addr (arg, stmt, |
4601 | offset, nbytes, lenrange, nulterm, | |
47e4ab65 | 4602 | allnul, allnonnul, snlim); |
b631bdb3 MS |
4603 | } |
4604 | ||
a9a437ff | 4605 | if (VAR_P (exp) || TREE_CODE (exp) == CONST_DECL) |
b631bdb3 | 4606 | { |
f0500db3 MS |
4607 | /* If EXP can be folded into a constant use the result. Otherwise |
4608 | proceed to use EXP to determine a range of the result. */ | |
4609 | if (tree fold_exp = ctor_for_folding (exp)) | |
4610 | if (fold_exp != error_mark_node) | |
4611 | exp = fold_exp; | |
b631bdb3 MS |
4612 | } |
4613 | ||
34fcf41e | 4614 | const char *prep = NULL; |
b631bdb3 MS |
4615 | if (TREE_CODE (exp) == STRING_CST) |
4616 | { | |
34fcf41e MS |
4617 | unsigned nchars = TREE_STRING_LENGTH (exp); |
4618 | if (nchars < offset) | |
4619 | return false; | |
b631bdb3 MS |
4620 | |
4621 | if (!nbytes) | |
1e9369c5 MS |
4622 | /* If NBYTES hasn't been determined earlier, either from ADDR_EXPR |
4623 | (i.e., it's the size of a pointer), or from MEM_REF (as the size | |
4624 | of the access), set it here to the size of the string, including | |
4625 | all internal and trailing nuls if the string has any. */ | |
34fcf41e | 4626 | nbytes = nchars - offset; |
741ff2a2 JJ |
4627 | else if (nchars - offset < nbytes) |
4628 | return false; | |
b631bdb3 MS |
4629 | |
4630 | prep = TREE_STRING_POINTER (exp) + offset; | |
4631 | } | |
4632 | ||
4633 | unsigned char buf[256]; | |
4634 | if (!prep) | |
4635 | { | |
a9a437ff JJ |
4636 | if (CHAR_BIT != 8 || BITS_PER_UNIT != 8) |
4637 | return false; | |
34fcf41e MS |
4638 | /* If the pointer to representation hasn't been set above |
4639 | for STRING_CST point it at the buffer. */ | |
4640 | prep = reinterpret_cast <char *>(buf); | |
4641 | /* Try to extract the representation of the constant object | |
4642 | or expression starting from the offset. */ | |
daa94de2 MS |
4643 | unsigned repsize = native_encode_expr (exp, buf, sizeof buf, offset); |
4644 | if (repsize < nbytes) | |
4645 | { | |
4646 | /* This should only happen when REPSIZE is zero because EXP | |
4647 | doesn't denote an object with a known initializer, except | |
4648 | perhaps when the reference reads past its end. */ | |
4649 | lenrange[0] = 0; | |
4650 | prep = NULL; | |
4651 | } | |
7c3ed632 | 4652 | else if (!nbytes) |
daa94de2 | 4653 | nbytes = repsize; |
7c3ed632 MS |
4654 | else if (nbytes < repsize) |
4655 | return false; | |
05ef3173 MS |
4656 | } |
4657 | ||
daa94de2 | 4658 | if (!nbytes) |
f0500db3 MS |
4659 | return nonzero_bytes_for_type (TREE_TYPE (exp), lenrange, |
4660 | nulterm, allnul, allnonnul); | |
daa94de2 | 4661 | |
b631bdb3 MS |
4662 | /* Compute the number of leading nonzero bytes in the representation |
4663 | and update the minimum and maximum. */ | |
daa94de2 | 4664 | unsigned n = prep ? strnlen (prep, nbytes) : nbytes; |
b631bdb3 MS |
4665 | |
4666 | if (n < lenrange[0]) | |
4667 | lenrange[0] = n; | |
4668 | if (lenrange[1] < n) | |
4669 | lenrange[1] = n; | |
4670 | ||
4671 | /* Set the size of the representation. */ | |
4672 | if (lenrange[2] < nbytes) | |
4673 | lenrange[2] = nbytes; | |
05ef3173 | 4674 | |
b631bdb3 MS |
4675 | /* Clear NULTERM if none of the bytes is zero. */ |
4676 | if (n == nbytes) | |
4677 | *nulterm = false; | |
4678 | ||
4679 | if (n) | |
4680 | { | |
4681 | /* When the initial number of non-zero bytes N is non-zero, reset | |
a9a437ff JJ |
4682 | *ALLNUL; if N is less than that the size of the representation |
4683 | also clear *ALLNONNUL. */ | |
b631bdb3 MS |
4684 | *allnul = false; |
4685 | if (n < nbytes) | |
4686 | *allnonnul = false; | |
4687 | } | |
4688 | else if (*allnul || *allnonnul) | |
aca8570e | 4689 | { |
b631bdb3 MS |
4690 | *allnonnul = false; |
4691 | ||
4692 | if (*allnul) | |
4693 | { | |
4694 | /* When either ALLNUL is set and N is zero, also determine | |
4695 | whether all subsequent bytes after the first one (which | |
4696 | is nul) are zero or nonzero and clear ALLNUL if not. */ | |
4697 | for (const char *p = prep; p != prep + nbytes; ++p) | |
4698 | if (*p) | |
4699 | { | |
4700 | *allnul = false; | |
4701 | break; | |
4702 | } | |
4703 | } | |
aca8570e | 4704 | } |
65f2d1ee | 4705 | |
b631bdb3 MS |
4706 | return true; |
4707 | } | |
4708 | ||
a9a437ff JJ |
4709 | /* Like count_nonzero_bytes, but instead of counting bytes in EXP, count |
4710 | bytes that are pointed to by EXP, which should be a pointer. */ | |
4711 | ||
47e4ab65 | 4712 | bool |
6b8b9596 | 4713 | strlen_pass::count_nonzero_bytes_addr (tree exp, gimple *stmt, |
47e4ab65 AH |
4714 | unsigned HOST_WIDE_INT offset, |
4715 | unsigned HOST_WIDE_INT nbytes, | |
4716 | unsigned lenrange[3], bool *nulterm, | |
4717 | bool *allnul, bool *allnonnul, | |
4718 | ssa_name_limit_t &snlim) | |
a9a437ff | 4719 | { |
6b8b9596 | 4720 | int idx = get_stridx (exp, stmt); |
a9a437ff JJ |
4721 | if (idx > 0) |
4722 | { | |
4723 | strinfo *si = get_strinfo (idx); | |
4724 | if (!si) | |
4725 | return false; | |
4726 | ||
4727 | /* Handle both constant lengths as well non-constant lengths | |
4728 | in some range. */ | |
4729 | unsigned HOST_WIDE_INT minlen, maxlen; | |
4730 | if (tree_fits_shwi_p (si->nonzero_chars)) | |
4731 | minlen = maxlen = tree_to_shwi (si->nonzero_chars); | |
4732 | else if (si->nonzero_chars | |
4733 | && TREE_CODE (si->nonzero_chars) == SSA_NAME) | |
4734 | { | |
f5299992 | 4735 | value_range vr; |
6b8b9596 | 4736 | ptr_qry.rvals->range_of_expr (vr, si->nonzero_chars, stmt); |
f5299992 | 4737 | if (vr.kind () != VR_RANGE) |
a9a437ff JJ |
4738 | return false; |
4739 | ||
f5299992 AH |
4740 | minlen = tree_to_uhwi (vr.min ()); |
4741 | maxlen = tree_to_uhwi (vr.max ()); | |
a9a437ff JJ |
4742 | } |
4743 | else | |
4744 | return false; | |
4745 | ||
4746 | if (maxlen < offset) | |
4747 | return false; | |
4748 | ||
4749 | minlen = minlen < offset ? 0 : minlen - offset; | |
4750 | maxlen -= offset; | |
4751 | if (maxlen + 1 < nbytes) | |
4752 | return false; | |
4753 | ||
4754 | if (nbytes <= minlen) | |
4755 | *nulterm = false; | |
4756 | ||
4757 | if (nbytes < minlen) | |
4758 | { | |
4759 | minlen = nbytes; | |
4760 | if (nbytes < maxlen) | |
4761 | maxlen = nbytes; | |
4762 | } | |
4763 | ||
4764 | if (minlen < lenrange[0]) | |
4765 | lenrange[0] = minlen; | |
4766 | if (lenrange[1] < maxlen) | |
4767 | lenrange[1] = maxlen; | |
4768 | ||
4769 | if (lenrange[2] < nbytes) | |
4770 | lenrange[2] = nbytes; | |
4771 | ||
4772 | /* Since only the length of the string are known and not its contents, | |
4773 | clear ALLNUL and ALLNONNUL purely on the basis of the length. */ | |
4774 | *allnul = false; | |
4775 | if (minlen < nbytes) | |
4776 | *allnonnul = false; | |
4777 | ||
4778 | return true; | |
4779 | } | |
4780 | ||
4781 | if (TREE_CODE (exp) == ADDR_EXPR) | |
6b8b9596 AH |
4782 | return count_nonzero_bytes (TREE_OPERAND (exp, 0), stmt, |
4783 | offset, nbytes, | |
47e4ab65 | 4784 | lenrange, nulterm, allnul, allnonnul, snlim); |
a9a437ff JJ |
4785 | |
4786 | if (TREE_CODE (exp) == SSA_NAME) | |
4787 | { | |
4788 | gimple *stmt = SSA_NAME_DEF_STMT (exp); | |
4789 | if (gimple_code (stmt) == GIMPLE_PHI) | |
4790 | { | |
4791 | /* Avoid processing an SSA_NAME that has already been visited | |
4792 | or if an SSA_NAME limit has been reached. Indicate success | |
4793 | if the former and failure if the latter. */ | |
eafe8ee7 | 4794 | if (int res = snlim.next_phi (exp)) |
a9a437ff JJ |
4795 | return res > 0; |
4796 | ||
4797 | /* Determine the minimum and maximum from the PHI arguments. */ | |
4798 | unsigned int n = gimple_phi_num_args (stmt); | |
4799 | for (unsigned i = 0; i != n; i++) | |
4800 | { | |
4801 | tree def = gimple_phi_arg_def (stmt, i); | |
6b8b9596 AH |
4802 | if (!count_nonzero_bytes_addr (def, stmt, |
4803 | offset, nbytes, lenrange, | |
47e4ab65 | 4804 | nulterm, allnul, allnonnul, |
a9a437ff JJ |
4805 | snlim)) |
4806 | return false; | |
4807 | } | |
4808 | ||
4809 | return true; | |
4810 | } | |
4811 | } | |
4812 | ||
4813 | /* Otherwise we don't know anything. */ | |
4814 | lenrange[0] = 0; | |
4815 | if (lenrange[1] < nbytes) | |
4816 | lenrange[1] = nbytes; | |
4817 | if (lenrange[2] < nbytes) | |
4818 | lenrange[2] = nbytes; | |
4819 | *nulterm = false; | |
4820 | *allnul = false; | |
4821 | *allnonnul = false; | |
4822 | return true; | |
4823 | } | |
4824 | ||
f0500db3 MS |
4825 | /* Same as above except with an implicit SSA_NAME limit. When EXPR_OR_TYPE |
4826 | is a type rather than an expression use its size to compute the range. | |
4827 | RVALS is used to determine ranges of dynamically computed string lengths | |
4828 | (the results of strlen). */ | |
b631bdb3 | 4829 | |
47e4ab65 | 4830 | bool |
6b8b9596 | 4831 | strlen_pass::count_nonzero_bytes (tree expr_or_type, gimple *stmt, |
47e4ab65 AH |
4832 | unsigned lenrange[3], bool *nulterm, |
4833 | bool *allnul, bool *allnonnul) | |
b631bdb3 | 4834 | { |
f0500db3 MS |
4835 | if (TYPE_P (expr_or_type)) |
4836 | return nonzero_bytes_for_type (expr_or_type, lenrange, | |
4837 | nulterm, allnul, allnonnul); | |
4838 | ||
b631bdb3 MS |
4839 | /* Set to optimistic values so the caller doesn't have to worry about |
4840 | initializing these and to what. On success, the function will clear | |
4841 | these if it determines their values are different but being recursive | |
4842 | it never sets either to true. On failure, their values are | |
4843 | unspecified. */ | |
4844 | *nulterm = true; | |
4845 | *allnul = true; | |
4846 | *allnonnul = true; | |
4847 | ||
4848 | ssa_name_limit_t snlim; | |
f0500db3 | 4849 | tree expr = expr_or_type; |
6b8b9596 AH |
4850 | return count_nonzero_bytes (expr, stmt, |
4851 | 0, 0, lenrange, nulterm, allnul, allnonnul, | |
47e4ab65 | 4852 | snlim); |
65f2d1ee PK |
4853 | } |
4854 | ||
b631bdb3 MS |
4855 | /* Handle a single or multibyte store other than by a built-in function, |
4856 | either via a single character assignment or by multi-byte assignment | |
4857 | either via MEM_REF or via a type other than char (such as in | |
79d2e614 JJ |
4858 | '*(int*)a = 12345'). Return true to let the caller advance *GSI to |
4859 | the next statement in the basic block and false otherwise. */ | |
8b57bfeb | 4860 | |
47e4ab65 AH |
4861 | bool |
4862 | strlen_pass::handle_store (bool *zero_write) | |
8b57bfeb | 4863 | { |
47e4ab65 | 4864 | gimple *stmt = gsi_stmt (m_gsi); |
f0500db3 MS |
4865 | /* The LHS and RHS of the store. The RHS is null if STMT is a function |
4866 | call. STORETYPE is the type of the store (determined from either | |
4867 | the RHS of the assignment statement or the LHS of a function call. */ | |
4868 | tree lhs, rhs, storetype; | |
4869 | if (is_gimple_assign (stmt)) | |
4870 | { | |
4871 | lhs = gimple_assign_lhs (stmt); | |
4872 | rhs = gimple_assign_rhs1 (stmt); | |
4873 | storetype = TREE_TYPE (rhs); | |
4874 | } | |
4875 | else if (is_gimple_call (stmt)) | |
4876 | { | |
4877 | lhs = gimple_call_lhs (stmt); | |
4878 | rhs = NULL_TREE; | |
4879 | storetype = TREE_TYPE (lhs); | |
4880 | } | |
4881 | else | |
4882 | return true; | |
4883 | ||
4884 | tree ssaname = NULL_TREE; | |
4885 | strinfo *si = NULL; | |
4886 | int idx = -1; | |
b631bdb3 | 4887 | |
d02c41dd MS |
4888 | range_query *const rvals = ptr_qry.rvals; |
4889 | ||
700d4cb0 | 4890 | /* The offset of the first byte in LHS modified by the store. */ |
e3f9a279 | 4891 | unsigned HOST_WIDE_INT offset = 0; |
8b57bfeb JJ |
4892 | |
4893 | if (TREE_CODE (lhs) == MEM_REF | |
4894 | && TREE_CODE (TREE_OPERAND (lhs, 0)) == SSA_NAME) | |
4895 | { | |
e3f9a279 RS |
4896 | tree mem_offset = TREE_OPERAND (lhs, 1); |
4897 | if (tree_fits_uhwi_p (mem_offset)) | |
8b57bfeb | 4898 | { |
e3f9a279 RS |
4899 | /* Get the strinfo for the base, and use it if it starts with at |
4900 | least OFFSET nonzero characters. This is trivially true if | |
4901 | OFFSET is zero. */ | |
4902 | offset = tree_to_uhwi (mem_offset); | |
6b8b9596 | 4903 | idx = get_stridx (TREE_OPERAND (lhs, 0), stmt); |
e3f9a279 RS |
4904 | if (idx > 0) |
4905 | si = get_strinfo (idx); | |
4906 | if (offset == 0) | |
4907 | ssaname = TREE_OPERAND (lhs, 0); | |
6b8b9596 AH |
4908 | else if (si == NULL |
4909 | || compare_nonzero_chars (si, stmt, offset, rvals) < 0) | |
2fcb55d1 | 4910 | { |
f0500db3 | 4911 | *zero_write = rhs ? initializer_zerop (rhs) : false; |
f7d86b5c MS |
4912 | |
4913 | bool dummy; | |
4914 | unsigned lenrange[] = { UINT_MAX, 0, 0 }; | |
6b8b9596 | 4915 | if (count_nonzero_bytes (rhs ? rhs : storetype, stmt, lenrange, |
47e4ab65 AH |
4916 | &dummy, &dummy, &dummy)) |
4917 | maybe_warn_overflow (stmt, true, lenrange[2]); | |
f7d86b5c | 4918 | |
2fcb55d1 MS |
4919 | return true; |
4920 | } | |
8b57bfeb JJ |
4921 | } |
4922 | } | |
4923 | else | |
e3f9a279 | 4924 | { |
6b8b9596 | 4925 | idx = get_addr_stridx (lhs, stmt, NULL_TREE, &offset, rvals); |
e3f9a279 RS |
4926 | if (idx > 0) |
4927 | si = get_strinfo (idx); | |
4928 | } | |
8b57bfeb | 4929 | |
b631bdb3 MS |
4930 | /* Minimum and maximum leading non-zero bytes and the size of the store. */ |
4931 | unsigned lenrange[] = { UINT_MAX, 0, 0 }; | |
4932 | ||
4933 | /* Set to the minimum length of the string being assigned if known. */ | |
4934 | unsigned HOST_WIDE_INT rhs_minlen; | |
4935 | ||
aca8570e | 4936 | /* STORING_NONZERO_P is true iff not all stored characters are zero. |
b631bdb3 | 4937 | STORING_ALL_NONZERO_P is true if all stored characters are zero. |
aca8570e MS |
4938 | STORING_ALL_ZEROS_P is true iff all stored characters are zero. |
4939 | Both are false when it's impossible to determine which is true. */ | |
4940 | bool storing_nonzero_p; | |
b631bdb3 MS |
4941 | bool storing_all_nonzero_p; |
4942 | bool storing_all_zeros_p; | |
4943 | /* FULL_STRING_P is set when the stored sequence of characters form | |
4944 | a nul-terminated string. */ | |
4945 | bool full_string_p; | |
aca8570e | 4946 | |
b631bdb3 | 4947 | const bool ranges_valid |
6b8b9596 AH |
4948 | = count_nonzero_bytes (rhs ? rhs : storetype, stmt, |
4949 | lenrange, &full_string_p, | |
47e4ab65 | 4950 | &storing_all_zeros_p, &storing_all_nonzero_p); |
f0500db3 | 4951 | |
b631bdb3 MS |
4952 | if (ranges_valid) |
4953 | { | |
4954 | rhs_minlen = lenrange[0]; | |
4955 | storing_nonzero_p = lenrange[1] > 0; | |
2fcb55d1 | 4956 | *zero_write = storing_all_zeros_p; |
b631bdb3 | 4957 | |
47e4ab65 | 4958 | maybe_warn_overflow (stmt, true, lenrange[2]); |
b631bdb3 MS |
4959 | } |
4960 | else | |
4961 | { | |
4962 | rhs_minlen = HOST_WIDE_INT_M1U; | |
4963 | full_string_p = false; | |
4964 | storing_nonzero_p = false; | |
4965 | storing_all_zeros_p = false; | |
4966 | storing_all_nonzero_p = false; | |
4967 | } | |
e3f9a279 RS |
4968 | |
4969 | if (si != NULL) | |
8b57bfeb | 4970 | { |
b631bdb3 MS |
4971 | /* The corresponding element is set to 1 if the first and last |
4972 | element, respectively, of the sequence of characters being | |
4973 | written over the string described by SI ends before | |
4974 | the terminating nul (if it has one), to zero if the nul is | |
4975 | being overwritten but not beyond, or negative otherwise. */ | |
4976 | int store_before_nul[2]; | |
4977 | if (ranges_valid) | |
4978 | { | |
4979 | /* The offset of the last stored byte. */ | |
4980 | unsigned HOST_WIDE_INT endoff = offset + lenrange[2] - 1; | |
6b8b9596 AH |
4981 | store_before_nul[0] |
4982 | = compare_nonzero_chars (si, stmt, offset, rvals); | |
b631bdb3 MS |
4983 | if (endoff == offset) |
4984 | store_before_nul[1] = store_before_nul[0]; | |
4985 | else | |
6b8b9596 AH |
4986 | store_before_nul[1] |
4987 | = compare_nonzero_chars (si, stmt, endoff, rvals); | |
b631bdb3 MS |
4988 | } |
4989 | else | |
4990 | { | |
6b8b9596 AH |
4991 | store_before_nul[0] |
4992 | = compare_nonzero_chars (si, stmt, offset, rvals); | |
b631bdb3 MS |
4993 | store_before_nul[1] = store_before_nul[0]; |
4994 | gcc_assert (offset == 0 || store_before_nul[0] >= 0); | |
4995 | } | |
4996 | ||
4997 | if (storing_all_zeros_p | |
4998 | && store_before_nul[0] == 0 | |
4999 | && store_before_nul[1] == 0 | |
5000 | && si->full_string_p) | |
8b57bfeb | 5001 | { |
e3f9a279 RS |
5002 | /* When overwriting a '\0' with a '\0', the store can be removed |
5003 | if we know it has been stored in the current function. */ | |
36bbc05d | 5004 | if (!stmt_could_throw_p (cfun, stmt) && si->writable) |
8b57bfeb | 5005 | { |
e3f9a279 RS |
5006 | unlink_stmt_vdef (stmt); |
5007 | release_defs (stmt); | |
47e4ab65 | 5008 | gsi_remove (&m_gsi, true); |
e3f9a279 | 5009 | return false; |
8b57bfeb JJ |
5010 | } |
5011 | else | |
e3f9a279 RS |
5012 | { |
5013 | si->writable = true; | |
47e4ab65 | 5014 | gsi_next (&m_gsi); |
e3f9a279 RS |
5015 | return false; |
5016 | } | |
8b57bfeb | 5017 | } |
c2e8bd51 | 5018 | |
b631bdb3 | 5019 | if (store_before_nul[1] > 0 |
c2e8bd51 | 5020 | && storing_nonzero_p |
b631bdb3 MS |
5021 | && lenrange[0] == lenrange[1] |
5022 | && lenrange[0] == lenrange[2] | |
f0500db3 | 5023 | && TREE_CODE (storetype) == INTEGER_TYPE) |
5b115c1f | 5024 | { |
b631bdb3 MS |
5025 | /* Handle a store of one or more non-nul characters that ends |
5026 | before the terminating nul of the destination and so does | |
5027 | not affect its length | |
c2e8bd51 | 5028 | If si->nonzero_chars > OFFSET, we aren't overwriting '\0', |
b631bdb3 MS |
5029 | and if we aren't storing '\0', we know that the length of |
5030 | the string and any other zero terminated string in memory | |
5031 | remains the same. In that case we move to the next gimple | |
5032 | statement and return to signal the caller that it shouldn't | |
5033 | invalidate anything. | |
c2e8bd51 | 5034 | |
dfea3d6f | 5035 | This is beneficial for cases like: |
c2e8bd51 MS |
5036 | |
5037 | char p[20]; | |
5038 | void foo (char *q) | |
5039 | { | |
5040 | strcpy (p, "foobar"); | |
5041 | size_t len = strlen (p); // can be folded to 6 | |
5042 | size_t len2 = strlen (q); // has to be computed | |
5043 | p[0] = 'X'; | |
5044 | size_t len3 = strlen (p); // can be folded to 6 | |
5045 | size_t len4 = strlen (q); // can be folded to len2 | |
5046 | bar (len, len2, len3, len4); | |
5047 | } */ | |
47e4ab65 | 5048 | gsi_next (&m_gsi); |
5b115c1f MP |
5049 | return false; |
5050 | } | |
c2e8bd51 MS |
5051 | |
5052 | if (storing_all_zeros_p | |
5053 | || storing_nonzero_p | |
b631bdb3 | 5054 | || (offset != 0 && store_before_nul[1] > 0)) |
e3f9a279 | 5055 | { |
aca8570e MS |
5056 | /* When STORING_NONZERO_P, we know that the string will start |
5057 | with at least OFFSET + 1 nonzero characters. If storing | |
5058 | a single character, set si->NONZERO_CHARS to the result. | |
5059 | If storing multiple characters, try to determine the number | |
5060 | of leading non-zero characters and set si->NONZERO_CHARS to | |
5061 | the result instead. | |
e3f9a279 | 5062 | |
aca8570e MS |
5063 | When STORING_ALL_ZEROS_P, we know that the string is now |
5064 | OFFSET characters long. | |
e3f9a279 RS |
5065 | |
5066 | Otherwise, we're storing an unknown value at offset OFFSET, | |
b631bdb3 MS |
5067 | so need to clip the nonzero_chars to OFFSET. |
5068 | Use the minimum length of the string (or individual character) | |
5069 | being stored if it's known. Otherwise, STORING_NONZERO_P | |
5070 | guarantees it's at least 1. */ | |
5071 | HOST_WIDE_INT len | |
5072 | = storing_nonzero_p && ranges_valid ? lenrange[0] : 1; | |
e3f9a279 RS |
5073 | location_t loc = gimple_location (stmt); |
5074 | tree oldlen = si->nonzero_chars; | |
b631bdb3 | 5075 | if (store_before_nul[1] == 0 && si->full_string_p) |
e3f9a279 RS |
5076 | /* We're overwriting the nul terminator with a nonzero or |
5077 | unknown character. If the previous stmt was a memcpy, | |
5078 | its length may be decreased. */ | |
47e4ab65 | 5079 | adjust_last_stmt (si, stmt, false); |
e3f9a279 RS |
5080 | si = unshare_strinfo (si); |
5081 | if (storing_nonzero_p) | |
aca8570e MS |
5082 | { |
5083 | gcc_assert (len >= 0); | |
5084 | si->nonzero_chars = build_int_cst (size_type_node, offset + len); | |
5085 | } | |
e3f9a279 RS |
5086 | else |
5087 | si->nonzero_chars = build_int_cst (size_type_node, offset); | |
34fcf41e MS |
5088 | |
5089 | /* Set FULL_STRING_P only if the length of the strings being | |
5090 | written is the same, and clear it if the strings have | |
5091 | different lengths. In the latter case the length stored | |
5092 | in si->NONZERO_CHARS becomes the lower bound. | |
5093 | FIXME: Handle the upper bound of the length if possible. */ | |
5094 | si->full_string_p = full_string_p && lenrange[0] == lenrange[1]; | |
5095 | ||
aca8570e | 5096 | if (storing_all_zeros_p |
e3f9a279 RS |
5097 | && ssaname |
5098 | && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ssaname)) | |
5099 | si->endptr = ssaname; | |
5100 | else | |
5101 | si->endptr = NULL; | |
5102 | si->next = 0; | |
5103 | si->stmt = NULL; | |
5104 | si->writable = true; | |
5105 | si->dont_invalidate = true; | |
5106 | if (oldlen) | |
5107 | { | |
5108 | tree adj = fold_build2_loc (loc, MINUS_EXPR, size_type_node, | |
5109 | si->nonzero_chars, oldlen); | |
5110 | adjust_related_strinfos (loc, si, adj); | |
5111 | } | |
5112 | else | |
5113 | si->prev = 0; | |
5114 | } | |
8b57bfeb | 5115 | } |
aca8570e | 5116 | else if (idx == 0 && (storing_all_zeros_p || storing_nonzero_p)) |
8b57bfeb JJ |
5117 | { |
5118 | if (ssaname) | |
e3f9a279 | 5119 | idx = new_stridx (ssaname); |
8b57bfeb | 5120 | else |
e3f9a279 RS |
5121 | idx = new_addr_stridx (lhs); |
5122 | if (idx != 0) | |
8b57bfeb | 5123 | { |
e3f9a279 | 5124 | tree ptr = (ssaname ? ssaname : build_fold_addr_expr (lhs)); |
34fcf41e MS |
5125 | |
5126 | HOST_WIDE_INT slen; | |
5127 | if (storing_all_zeros_p) | |
5128 | slen = 0; | |
5129 | else if (storing_nonzero_p && ranges_valid) | |
5130 | { | |
5131 | /* FIXME: Handle the upper bound of the length when | |
5132 | LENRANGE[0] != LENRANGE[1]. */ | |
5133 | slen = lenrange[0]; | |
5134 | if (lenrange[0] != lenrange[1]) | |
5135 | /* Set the minimum length but ignore the maximum | |
5136 | for now. */ | |
5137 | full_string_p = false; | |
5138 | } | |
5139 | else | |
5140 | slen = -1; | |
5141 | ||
aca8570e MS |
5142 | tree len = (slen <= 0 |
5143 | ? size_zero_node | |
5144 | : build_int_cst (size_type_node, slen)); | |
5145 | si = new_strinfo (ptr, idx, len, slen >= 0 && full_string_p); | |
e3f9a279 | 5146 | set_strinfo (idx, si); |
aca8570e | 5147 | if (storing_all_zeros_p |
e3f9a279 RS |
5148 | && ssaname |
5149 | && !SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ssaname)) | |
5150 | si->endptr = ssaname; | |
5151 | si->dont_invalidate = true; | |
5152 | si->writable = true; | |
8b57bfeb | 5153 | } |
8b57bfeb | 5154 | } |
198fe1bf | 5155 | else if (idx == 0 |
b631bdb3 | 5156 | && rhs_minlen < HOST_WIDE_INT_M1U |
198fe1bf JJ |
5157 | && ssaname == NULL_TREE |
5158 | && TREE_CODE (TREE_TYPE (lhs)) == ARRAY_TYPE) | |
5159 | { | |
198fe1bf | 5160 | HOST_WIDE_INT a = int_size_in_bytes (TREE_TYPE (lhs)); |
b631bdb3 | 5161 | if (a > 0 && (unsigned HOST_WIDE_INT) a > rhs_minlen) |
198fe1bf JJ |
5162 | { |
5163 | int idx = new_addr_stridx (lhs); | |
5164 | if (idx != 0) | |
5165 | { | |
5166 | si = new_strinfo (build_fold_addr_expr (lhs), idx, | |
b631bdb3 | 5167 | build_int_cst (size_type_node, rhs_minlen), |
aca8570e | 5168 | full_string_p); |
198fe1bf JJ |
5169 | set_strinfo (idx, si); |
5170 | si->dont_invalidate = true; | |
5171 | } | |
5172 | } | |
5173 | } | |
8b57bfeb | 5174 | |
e13f37d9 | 5175 | if (si != NULL && offset == 0 && storing_all_zeros_p && lenrange[2] == 1) |
8b57bfeb | 5176 | { |
e13f37d9 MS |
5177 | /* For single-byte stores only, allow adjust_last_stmt to remove |
5178 | the statement if the stored '\0' is immediately overwritten. */ | |
8b57bfeb JJ |
5179 | laststmt.stmt = stmt; |
5180 | laststmt.len = build_int_cst (size_type_node, 1); | |
5181 | laststmt.stridx = si->idx; | |
5182 | } | |
5183 | return true; | |
5184 | } | |
5185 | ||
f368600f | 5186 | /* Try to fold strstr (s, t) eq/ne s to strncmp (s, t, strlen (t)) eq/ne 0. */ |
3b1970cb PK |
5187 | |
5188 | static void | |
f368600f | 5189 | fold_strstr_to_strncmp (tree rhs1, tree rhs2, gimple *stmt) |
3b1970cb PK |
5190 | { |
5191 | if (TREE_CODE (rhs1) != SSA_NAME | |
5192 | || TREE_CODE (rhs2) != SSA_NAME) | |
5193 | return; | |
5194 | ||
5195 | gimple *call_stmt = NULL; | |
5196 | for (int pass = 0; pass < 2; pass++) | |
5197 | { | |
5198 | gimple *g = SSA_NAME_DEF_STMT (rhs1); | |
5199 | if (gimple_call_builtin_p (g, BUILT_IN_STRSTR) | |
5200 | && has_single_use (rhs1) | |
5201 | && gimple_call_arg (g, 0) == rhs2) | |
5202 | { | |
5203 | call_stmt = g; | |
5204 | break; | |
5205 | } | |
5206 | std::swap (rhs1, rhs2); | |
5207 | } | |
5208 | ||
5209 | if (call_stmt) | |
5210 | { | |
5211 | tree arg0 = gimple_call_arg (call_stmt, 0); | |
5212 | ||
5213 | if (arg0 == rhs2) | |
5214 | { | |
5215 | tree arg1 = gimple_call_arg (call_stmt, 1); | |
5216 | tree arg1_len = NULL_TREE; | |
6b8b9596 | 5217 | int idx = get_stridx (arg1, call_stmt); |
3b1970cb PK |
5218 | |
5219 | if (idx) | |
5220 | { | |
5221 | if (idx < 0) | |
5222 | arg1_len = build_int_cst (size_type_node, ~idx); | |
5223 | else | |
5224 | { | |
5225 | strinfo *si = get_strinfo (idx); | |
5226 | if (si) | |
5227 | arg1_len = get_string_length (si); | |
5228 | } | |
5229 | } | |
5230 | ||
5231 | if (arg1_len != NULL_TREE) | |
5232 | { | |
5233 | gimple_stmt_iterator gsi = gsi_for_stmt (call_stmt); | |
f368600f | 5234 | tree strncmp_decl = builtin_decl_explicit (BUILT_IN_STRNCMP); |
96863f32 ML |
5235 | |
5236 | if (!is_gimple_val (arg1_len)) | |
5237 | { | |
5238 | tree arg1_len_tmp = make_ssa_name (TREE_TYPE (arg1_len)); | |
5239 | gassign *arg1_stmt = gimple_build_assign (arg1_len_tmp, | |
5240 | arg1_len); | |
5241 | gsi_insert_before (&gsi, arg1_stmt, GSI_SAME_STMT); | |
5242 | arg1_len = arg1_len_tmp; | |
5243 | } | |
5244 | ||
f368600f | 5245 | gcall *strncmp_call = gimple_build_call (strncmp_decl, 3, |
3b1970cb | 5246 | arg0, arg1, arg1_len); |
f368600f ML |
5247 | tree strncmp_lhs = make_ssa_name (integer_type_node); |
5248 | gimple_set_vuse (strncmp_call, gimple_vuse (call_stmt)); | |
5249 | gimple_call_set_lhs (strncmp_call, strncmp_lhs); | |
3b1970cb | 5250 | gsi_remove (&gsi, true); |
f368600f ML |
5251 | gsi_insert_before (&gsi, strncmp_call, GSI_SAME_STMT); |
5252 | tree zero = build_zero_cst (TREE_TYPE (strncmp_lhs)); | |
3b1970cb PK |
5253 | |
5254 | if (is_gimple_assign (stmt)) | |
5255 | { | |
5256 | if (gimple_assign_rhs_code (stmt) == COND_EXPR) | |
5257 | { | |
5258 | tree cond = gimple_assign_rhs1 (stmt); | |
f368600f | 5259 | TREE_OPERAND (cond, 0) = strncmp_lhs; |
3b1970cb PK |
5260 | TREE_OPERAND (cond, 1) = zero; |
5261 | } | |
5262 | else | |
5263 | { | |
f368600f | 5264 | gimple_assign_set_rhs1 (stmt, strncmp_lhs); |
3b1970cb PK |
5265 | gimple_assign_set_rhs2 (stmt, zero); |
5266 | } | |
5267 | } | |
5268 | else | |
5269 | { | |
5270 | gcond *cond = as_a<gcond *> (stmt); | |
f368600f | 5271 | gimple_cond_set_lhs (cond, strncmp_lhs); |
3b1970cb PK |
5272 | gimple_cond_set_rhs (cond, zero); |
5273 | } | |
5274 | update_stmt (stmt); | |
5275 | } | |
5276 | } | |
5277 | } | |
5278 | } | |
5279 | ||
b631bdb3 MS |
5280 | /* Return true if TYPE corresponds to a narrow character type. */ |
5281 | ||
5282 | static bool | |
5283 | is_char_type (tree type) | |
5284 | { | |
5285 | return (TREE_CODE (type) == INTEGER_TYPE | |
5286 | && TYPE_MODE (type) == TYPE_MODE (char_type_node) | |
5287 | && TYPE_PRECISION (type) == TYPE_PRECISION (char_type_node)); | |
5288 | } | |
5289 | ||
22fca489 | 5290 | /* Check the built-in call at GSI for validity and optimize it. |
ef29b12c | 5291 | Uses RVALS to determine range information. |
79d2e614 JJ |
5292 | Return true to let the caller advance *GSI to the next statement |
5293 | in the basic block and false otherwise. */ | |
22fca489 | 5294 | |
47e4ab65 AH |
5295 | bool |
5296 | strlen_pass::check_and_optimize_call (bool *zero_write) | |
22fca489 | 5297 | { |
47e4ab65 | 5298 | gimple *stmt = gsi_stmt (m_gsi); |
22fca489 | 5299 | |
ef29b12c MS |
5300 | if (!gimple_call_builtin_p (stmt, BUILT_IN_NORMAL)) |
5301 | { | |
5302 | tree fntype = gimple_call_fntype (stmt); | |
f0500db3 MS |
5303 | if (!fntype) |
5304 | return true; | |
5305 | ||
5306 | if (lookup_attribute ("alloc_size", TYPE_ATTRIBUTES (fntype))) | |
5307 | { | |
47e4ab65 | 5308 | handle_alloc_call (BUILT_IN_NONE); |
f0500db3 MS |
5309 | return true; |
5310 | } | |
5311 | ||
5312 | if (tree lhs = gimple_call_lhs (stmt)) | |
47e4ab65 | 5313 | handle_assign (lhs, zero_write); |
f0500db3 MS |
5314 | |
5315 | /* Proceed to handle user-defined formatting functions. */ | |
ef29b12c MS |
5316 | } |
5317 | ||
79d2e614 JJ |
5318 | /* When not optimizing we must be checking printf calls which |
5319 | we do even for user-defined functions when they are declared | |
5320 | with attribute format. */ | |
22fca489 MS |
5321 | if (!flag_optimize_strlen |
5322 | || !strlen_optimize | |
5323 | || !valid_builtin_call (stmt)) | |
47e4ab65 | 5324 | return !handle_printf_call (&m_gsi, ptr_qry); |
22fca489 MS |
5325 | |
5326 | tree callee = gimple_call_fndecl (stmt); | |
5327 | switch (DECL_FUNCTION_CODE (callee)) | |
5328 | { | |
5329 | case BUILT_IN_STRLEN: | |
5330 | case BUILT_IN_STRNLEN: | |
47e4ab65 | 5331 | handle_builtin_strlen (); |
22fca489 MS |
5332 | break; |
5333 | case BUILT_IN_STRCHR: | |
47e4ab65 | 5334 | handle_builtin_strchr (); |
22fca489 MS |
5335 | break; |
5336 | case BUILT_IN_STRCPY: | |
5337 | case BUILT_IN_STRCPY_CHK: | |
5338 | case BUILT_IN_STPCPY: | |
5339 | case BUILT_IN_STPCPY_CHK: | |
47e4ab65 | 5340 | handle_builtin_strcpy (DECL_FUNCTION_CODE (callee)); |
22fca489 MS |
5341 | break; |
5342 | ||
5343 | case BUILT_IN_STRNCAT: | |
5344 | case BUILT_IN_STRNCAT_CHK: | |
47e4ab65 | 5345 | handle_builtin_strncat (DECL_FUNCTION_CODE (callee)); |
22fca489 MS |
5346 | break; |
5347 | ||
5348 | case BUILT_IN_STPNCPY: | |
5349 | case BUILT_IN_STPNCPY_CHK: | |
5350 | case BUILT_IN_STRNCPY: | |
5351 | case BUILT_IN_STRNCPY_CHK: | |
47e4ab65 | 5352 | handle_builtin_stxncpy_strncat (false); |
22fca489 MS |
5353 | break; |
5354 | ||
5355 | case BUILT_IN_MEMCPY: | |
5356 | case BUILT_IN_MEMCPY_CHK: | |
5357 | case BUILT_IN_MEMPCPY: | |
5358 | case BUILT_IN_MEMPCPY_CHK: | |
47e4ab65 | 5359 | handle_builtin_memcpy (DECL_FUNCTION_CODE (callee)); |
22fca489 MS |
5360 | break; |
5361 | case BUILT_IN_STRCAT: | |
5362 | case BUILT_IN_STRCAT_CHK: | |
47e4ab65 | 5363 | handle_builtin_strcat (DECL_FUNCTION_CODE (callee)); |
22fca489 | 5364 | break; |
ef29b12c MS |
5365 | case BUILT_IN_ALLOCA: |
5366 | case BUILT_IN_ALLOCA_WITH_ALIGN: | |
22fca489 MS |
5367 | case BUILT_IN_MALLOC: |
5368 | case BUILT_IN_CALLOC: | |
47e4ab65 | 5369 | handle_alloc_call (DECL_FUNCTION_CODE (callee)); |
22fca489 MS |
5370 | break; |
5371 | case BUILT_IN_MEMSET: | |
47e4ab65 | 5372 | if (handle_builtin_memset (zero_write)) |
22fca489 MS |
5373 | return false; |
5374 | break; | |
5375 | case BUILT_IN_MEMCMP: | |
47e4ab65 | 5376 | if (handle_builtin_memcmp ()) |
22fca489 MS |
5377 | return false; |
5378 | break; | |
5379 | case BUILT_IN_STRCMP: | |
5380 | case BUILT_IN_STRNCMP: | |
47e4ab65 | 5381 | if (handle_builtin_string_cmp ()) |
22fca489 MS |
5382 | return false; |
5383 | break; | |
5384 | default: | |
47e4ab65 | 5385 | if (handle_printf_call (&m_gsi, ptr_qry)) |
79d2e614 | 5386 | return false; |
22fca489 MS |
5387 | break; |
5388 | } | |
5389 | ||
5390 | return true; | |
5391 | } | |
5392 | ||
5393 | /* Handle an assignment statement at *GSI to a LHS of integral type. | |
5394 | If GSI's basic block needs clean-up of EH, set *CLEANUP_EH to true. */ | |
5395 | ||
47e4ab65 AH |
5396 | void |
5397 | strlen_pass::handle_integral_assign (bool *cleanup_eh) | |
22fca489 | 5398 | { |
47e4ab65 | 5399 | gimple *stmt = gsi_stmt (m_gsi); |
22fca489 MS |
5400 | tree lhs = gimple_assign_lhs (stmt); |
5401 | tree lhs_type = TREE_TYPE (lhs); | |
5402 | ||
5403 | enum tree_code code = gimple_assign_rhs_code (stmt); | |
5404 | if (code == COND_EXPR) | |
5405 | { | |
5406 | tree cond = gimple_assign_rhs1 (stmt); | |
5407 | enum tree_code cond_code = TREE_CODE (cond); | |
5408 | ||
5409 | if (cond_code == EQ_EXPR || cond_code == NE_EXPR) | |
5410 | fold_strstr_to_strncmp (TREE_OPERAND (cond, 0), | |
5411 | TREE_OPERAND (cond, 1), stmt); | |
5412 | } | |
5413 | else if (code == EQ_EXPR || code == NE_EXPR) | |
5414 | fold_strstr_to_strncmp (gimple_assign_rhs1 (stmt), | |
5415 | gimple_assign_rhs2 (stmt), stmt); | |
5416 | else if (gimple_assign_load_p (stmt) | |
5417 | && TREE_CODE (lhs_type) == INTEGER_TYPE | |
5418 | && TYPE_MODE (lhs_type) == TYPE_MODE (char_type_node) | |
5419 | && (TYPE_PRECISION (lhs_type) | |
5420 | == TYPE_PRECISION (char_type_node)) | |
5421 | && !gimple_has_volatile_ops (stmt)) | |
5422 | { | |
5423 | tree off = integer_zero_node; | |
5424 | unsigned HOST_WIDE_INT coff = 0; | |
5425 | int idx = 0; | |
5426 | tree rhs1 = gimple_assign_rhs1 (stmt); | |
5427 | if (code == MEM_REF) | |
5428 | { | |
6b8b9596 | 5429 | idx = get_stridx (TREE_OPERAND (rhs1, 0), stmt); |
22fca489 MS |
5430 | if (idx > 0) |
5431 | { | |
5432 | strinfo *si = get_strinfo (idx); | |
5433 | if (si | |
5434 | && si->nonzero_chars | |
5435 | && TREE_CODE (si->nonzero_chars) == INTEGER_CST | |
5436 | && (wi::to_widest (si->nonzero_chars) | |
5437 | >= wi::to_widest (off))) | |
5438 | off = TREE_OPERAND (rhs1, 1); | |
5439 | else | |
5440 | /* This case is not useful. See if get_addr_stridx | |
5441 | returns something usable. */ | |
5442 | idx = 0; | |
5443 | } | |
5444 | } | |
5445 | if (idx <= 0) | |
6b8b9596 | 5446 | idx = get_addr_stridx (rhs1, stmt, NULL_TREE, &coff); |
22fca489 MS |
5447 | if (idx > 0) |
5448 | { | |
5449 | strinfo *si = get_strinfo (idx); | |
5450 | if (si | |
5451 | && si->nonzero_chars | |
5452 | && TREE_CODE (si->nonzero_chars) == INTEGER_CST) | |
5453 | { | |
5454 | widest_int w1 = wi::to_widest (si->nonzero_chars); | |
5455 | widest_int w2 = wi::to_widest (off) + coff; | |
5456 | if (w1 == w2 | |
5457 | && si->full_string_p) | |
5458 | { | |
5459 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
5460 | { | |
5461 | fprintf (dump_file, "Optimizing: "); | |
5462 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
5463 | } | |
5464 | ||
5465 | /* Reading the final '\0' character. */ | |
5466 | tree zero = build_int_cst (lhs_type, 0); | |
5467 | gimple_set_vuse (stmt, NULL_TREE); | |
47e4ab65 | 5468 | gimple_assign_set_rhs_from_tree (&m_gsi, zero); |
22fca489 MS |
5469 | *cleanup_eh |
5470 | |= maybe_clean_or_replace_eh_stmt (stmt, | |
47e4ab65 AH |
5471 | gsi_stmt (m_gsi)); |
5472 | stmt = gsi_stmt (m_gsi); | |
22fca489 MS |
5473 | update_stmt (stmt); |
5474 | ||
5475 | if (dump_file && (dump_flags & TDF_DETAILS) != 0) | |
5476 | { | |
5477 | fprintf (dump_file, "into: "); | |
5478 | print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); | |
5479 | } | |
5480 | } | |
5481 | else if (w1 > w2) | |
5482 | { | |
5483 | /* Reading a character before the final '\0' | |
5484 | character. Just set the value range to ~[0, 0] | |
5485 | if we don't have anything better. */ | |
45f4e2b0 AH |
5486 | value_range r; |
5487 | if (!get_range_query (cfun)->range_of_expr (r, lhs) | |
5488 | || r.varying_p ()) | |
5489 | { | |
5490 | r.set_nonzero (lhs_type); | |
5491 | set_range_info (lhs, r); | |
5492 | } | |
22fca489 MS |
5493 | } |
5494 | } | |
5495 | } | |
5496 | } | |
ef29b12c MS |
5497 | else if (code == MEM_REF && TREE_CODE (lhs) == SSA_NAME) |
5498 | { | |
5499 | if (int idx = new_stridx (lhs)) | |
5500 | { | |
5501 | /* Record multi-byte assignments from MEM_REFs. */ | |
5502 | bool storing_all_nonzero_p; | |
5503 | bool storing_all_zeros_p; | |
5504 | bool full_string_p; | |
5505 | unsigned lenrange[] = { UINT_MAX, 0, 0 }; | |
5506 | tree rhs = gimple_assign_rhs1 (stmt); | |
5507 | const bool ranges_valid | |
6b8b9596 AH |
5508 | = count_nonzero_bytes (rhs, stmt, |
5509 | lenrange, &full_string_p, | |
47e4ab65 AH |
5510 | &storing_all_zeros_p, |
5511 | &storing_all_nonzero_p); | |
ef29b12c MS |
5512 | if (ranges_valid) |
5513 | { | |
5514 | tree length = build_int_cst (sizetype, lenrange[0]); | |
5515 | strinfo *si = new_strinfo (lhs, idx, length, full_string_p); | |
5516 | set_strinfo (idx, si); | |
5517 | si->writable = true; | |
5518 | si->dont_invalidate = true; | |
ef29b12c MS |
5519 | } |
5520 | } | |
5521 | } | |
22fca489 MS |
5522 | |
5523 | if (strlen_to_stridx) | |
5524 | { | |
5525 | tree rhs1 = gimple_assign_rhs1 (stmt); | |
5526 | if (stridx_strlenloc *ps = strlen_to_stridx->get (rhs1)) | |
5527 | strlen_to_stridx->put (lhs, stridx_strlenloc (*ps)); | |
5528 | } | |
5529 | } | |
5530 | ||
f0500db3 MS |
5531 | /* Handle assignment statement at *GSI to LHS. Set *ZERO_WRITE if |
5532 | the assignent stores all zero bytes.. */ | |
5533 | ||
47e4ab65 AH |
5534 | bool |
5535 | strlen_pass::handle_assign (tree lhs, bool *zero_write) | |
f0500db3 MS |
5536 | { |
5537 | tree type = TREE_TYPE (lhs); | |
5538 | if (TREE_CODE (type) == ARRAY_TYPE) | |
5539 | type = TREE_TYPE (type); | |
5540 | ||
5541 | bool is_char_store = is_char_type (type); | |
5542 | if (!is_char_store && TREE_CODE (lhs) == MEM_REF) | |
5543 | { | |
5544 | /* To consider stores into char objects via integer types other | |
5545 | than char but not those to non-character objects, determine | |
5546 | the type of the destination rather than just the type of | |
5547 | the access. */ | |
5548 | for (int i = 0; i != 2; ++i) | |
5549 | { | |
5550 | tree ref = TREE_OPERAND (lhs, i); | |
5551 | type = TREE_TYPE (ref); | |
5552 | if (TREE_CODE (type) == POINTER_TYPE) | |
5553 | type = TREE_TYPE (type); | |
5554 | if (TREE_CODE (type) == ARRAY_TYPE) | |
5555 | type = TREE_TYPE (type); | |
5556 | if (is_char_type (type)) | |
5557 | { | |
5558 | is_char_store = true; | |
5559 | break; | |
5560 | } | |
5561 | } | |
5562 | } | |
5563 | ||
5564 | /* Handle a single or multibyte assignment. */ | |
47e4ab65 | 5565 | if (is_char_store && !handle_store (zero_write)) |
f0500db3 MS |
5566 | return false; |
5567 | ||
5568 | return true; | |
5569 | } | |
5570 | ||
5571 | ||
cc8bea0a | 5572 | /* Attempt to check for validity of the performed access a single statement |
fa9544ab ML |
5573 | at *GSI using string length knowledge, and to optimize it. |
5574 | If the given basic block needs clean-up of EH, CLEANUP_EH is set to | |
79d2e614 JJ |
5575 | true. Return true to let the caller advance *GSI to the next statement |
5576 | in the basic block and false otherwise. */ | |
8b57bfeb | 5577 | |
47e4ab65 AH |
5578 | bool |
5579 | strlen_pass::check_and_optimize_stmt (bool *cleanup_eh) | |
8b57bfeb | 5580 | { |
47e4ab65 | 5581 | gimple *stmt = gsi_stmt (m_gsi); |
8b57bfeb | 5582 | |
2fcb55d1 MS |
5583 | /* For statements that modify a string, set to true if the write |
5584 | is only zeros. */ | |
5585 | bool zero_write = false; | |
5586 | ||
8b57bfeb JJ |
5587 | if (is_gimple_call (stmt)) |
5588 | { | |
47e4ab65 | 5589 | if (!check_and_optimize_call (&zero_write)) |
22fca489 | 5590 | return false; |
8b57bfeb | 5591 | } |
22fca489 MS |
5592 | else if (!flag_optimize_strlen || !strlen_optimize) |
5593 | return true; | |
5004bd00 | 5594 | else if (is_gimple_assign (stmt) && !gimple_clobber_p (stmt)) |
8b57bfeb | 5595 | { |
22fca489 | 5596 | /* Handle non-clobbering assignment. */ |
8b57bfeb | 5597 | tree lhs = gimple_assign_lhs (stmt); |
22fca489 | 5598 | tree lhs_type = TREE_TYPE (lhs); |
8b57bfeb | 5599 | |
22fca489 | 5600 | if (TREE_CODE (lhs) == SSA_NAME && POINTER_TYPE_P (lhs_type)) |
8b57bfeb JJ |
5601 | { |
5602 | if (gimple_assign_single_p (stmt) | |
5603 | || (gimple_assign_cast_p (stmt) | |
5604 | && POINTER_TYPE_P (TREE_TYPE (gimple_assign_rhs1 (stmt))))) | |
5605 | { | |
6b8b9596 | 5606 | int idx = get_stridx (gimple_assign_rhs1 (stmt), stmt); |
9771b263 | 5607 | ssa_ver_to_stridx[SSA_NAME_VERSION (lhs)] = idx; |
8b57bfeb JJ |
5608 | } |
5609 | else if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR) | |
47e4ab65 | 5610 | handle_pointer_plus (); |
8b57bfeb | 5611 | } |
22fca489 MS |
5612 | else if (TREE_CODE (lhs) == SSA_NAME && INTEGRAL_TYPE_P (lhs_type)) |
5613 | /* Handle assignment to a character. */ | |
47e4ab65 | 5614 | handle_integral_assign (cleanup_eh); |
22fca489 | 5615 | else if (TREE_CODE (lhs) != SSA_NAME && !TREE_SIDE_EFFECTS (lhs)) |
47e4ab65 | 5616 | if (!handle_assign (lhs, &zero_write)) |
f0500db3 | 5617 | return false; |
8b57bfeb | 5618 | } |
3b1970cb PK |
5619 | else if (gcond *cond = dyn_cast<gcond *> (stmt)) |
5620 | { | |
5621 | enum tree_code code = gimple_cond_code (cond); | |
5622 | if (code == EQ_EXPR || code == NE_EXPR) | |
f368600f ML |
5623 | fold_strstr_to_strncmp (gimple_cond_lhs (stmt), |
5624 | gimple_cond_rhs (stmt), stmt); | |
3b1970cb | 5625 | } |
8b57bfeb JJ |
5626 | |
5627 | if (gimple_vdef (stmt)) | |
2fcb55d1 | 5628 | maybe_invalidate (stmt, zero_write); |
8b57bfeb JJ |
5629 | return true; |
5630 | } | |
5631 | ||
5632 | /* Recursively call maybe_invalidate on stmts that might be executed | |
5633 | in between dombb and current bb and that contain a vdef. Stop when | |
5634 | *count stmts are inspected, or if the whole strinfo vector has | |
5635 | been invalidated. */ | |
5636 | ||
5637 | static void | |
355fe088 | 5638 | do_invalidate (basic_block dombb, gimple *phi, bitmap visited, int *count) |
8b57bfeb JJ |
5639 | { |
5640 | unsigned int i, n = gimple_phi_num_args (phi); | |
5641 | ||
5642 | for (i = 0; i < n; i++) | |
5643 | { | |
5644 | tree vuse = gimple_phi_arg_def (phi, i); | |
355fe088 | 5645 | gimple *stmt = SSA_NAME_DEF_STMT (vuse); |
8b57bfeb JJ |
5646 | basic_block bb = gimple_bb (stmt); |
5647 | if (bb == NULL | |
5648 | || bb == dombb | |
5649 | || !bitmap_set_bit (visited, bb->index) | |
5650 | || !dominated_by_p (CDI_DOMINATORS, bb, dombb)) | |
5651 | continue; | |
5652 | while (1) | |
5653 | { | |
5654 | if (gimple_code (stmt) == GIMPLE_PHI) | |
5655 | { | |
5656 | do_invalidate (dombb, stmt, visited, count); | |
5657 | if (*count == 0) | |
5658 | return; | |
5659 | break; | |
5660 | } | |
5661 | if (--*count == 0) | |
5662 | return; | |
5663 | if (!maybe_invalidate (stmt)) | |
5664 | { | |
5665 | *count = 0; | |
5666 | return; | |
5667 | } | |
5668 | vuse = gimple_vuse (stmt); | |
5669 | stmt = SSA_NAME_DEF_STMT (vuse); | |
5670 | if (gimple_bb (stmt) != bb) | |
5671 | { | |
5672 | bb = gimple_bb (stmt); | |
5673 | if (bb == NULL | |
5674 | || bb == dombb | |
5675 | || !bitmap_set_bit (visited, bb->index) | |
5676 | || !dominated_by_p (CDI_DOMINATORS, bb, dombb)) | |
5677 | break; | |
5678 | } | |
5679 | } | |
5680 | } | |
5681 | } | |
5682 | ||
5c3d388a MS |
5683 | /* Release pointer_query cache. */ |
5684 | ||
47e4ab65 | 5685 | strlen_pass::~strlen_pass () |
5c3d388a MS |
5686 | { |
5687 | ptr_qry.flush_cache (); | |
5688 | } | |
5689 | ||
8b57bfeb | 5690 | /* Callback for walk_dominator_tree. Attempt to optimize various |
c7880c8c | 5691 | string ops by remembering string lengths pointed by pointer SSA_NAMEs. */ |
8b57bfeb | 5692 | |
3daacdcd | 5693 | edge |
47e4ab65 | 5694 | strlen_pass::before_dom_children (basic_block bb) |
8b57bfeb | 5695 | { |
8b57bfeb JJ |
5696 | basic_block dombb = get_immediate_dominator (CDI_DOMINATORS, bb); |
5697 | ||
5698 | if (dombb == NULL) | |
5699 | stridx_to_strinfo = NULL; | |
5700 | else | |
5701 | { | |
526ceb68 | 5702 | stridx_to_strinfo = ((vec<strinfo *, va_heap, vl_embed> *) dombb->aux); |
8b57bfeb JJ |
5703 | if (stridx_to_strinfo) |
5704 | { | |
538dd0b7 DM |
5705 | for (gphi_iterator gsi = gsi_start_phis (bb); !gsi_end_p (gsi); |
5706 | gsi_next (&gsi)) | |
8b57bfeb | 5707 | { |
538dd0b7 | 5708 | gphi *phi = gsi.phi (); |
ea057359 | 5709 | if (virtual_operand_p (gimple_phi_result (phi))) |
8b57bfeb JJ |
5710 | { |
5711 | bitmap visited = BITMAP_ALLOC (NULL); | |
5712 | int count_vdef = 100; | |
5713 | do_invalidate (dombb, phi, visited, &count_vdef); | |
5714 | BITMAP_FREE (visited); | |
8b29fd4e JJ |
5715 | if (count_vdef == 0) |
5716 | { | |
5717 | /* If there were too many vdefs in between immediate | |
5718 | dominator and current bb, invalidate everything. | |
5719 | If stridx_to_strinfo has been unshared, we need | |
5720 | to free it, otherwise just set it to NULL. */ | |
5721 | if (!strinfo_shared ()) | |
5722 | { | |
5723 | unsigned int i; | |
526ceb68 | 5724 | strinfo *si; |
8b29fd4e JJ |
5725 | |
5726 | for (i = 1; | |
5727 | vec_safe_iterate (stridx_to_strinfo, i, &si); | |
5728 | ++i) | |
5729 | { | |
5730 | free_strinfo (si); | |
5731 | (*stridx_to_strinfo)[i] = NULL; | |
5732 | } | |
5733 | } | |
5734 | else | |
5735 | stridx_to_strinfo = NULL; | |
5736 | } | |
8b57bfeb JJ |
5737 | break; |
5738 | } | |
5739 | } | |
5740 | } | |
5741 | } | |
5742 | ||
5743 | /* If all PHI arguments have the same string index, the PHI result | |
5744 | has it as well. */ | |
538dd0b7 DM |
5745 | for (gphi_iterator gsi = gsi_start_phis (bb); !gsi_end_p (gsi); |
5746 | gsi_next (&gsi)) | |
8b57bfeb | 5747 | { |
538dd0b7 | 5748 | gphi *phi = gsi.phi (); |
8b57bfeb | 5749 | tree result = gimple_phi_result (phi); |
ea057359 | 5750 | if (!virtual_operand_p (result) && POINTER_TYPE_P (TREE_TYPE (result))) |
8b57bfeb | 5751 | { |
6b8b9596 | 5752 | int idx = get_stridx (gimple_phi_arg_def (phi, 0), phi); |
8b57bfeb JJ |
5753 | if (idx != 0) |
5754 | { | |
5755 | unsigned int i, n = gimple_phi_num_args (phi); | |
5756 | for (i = 1; i < n; i++) | |
6b8b9596 | 5757 | if (idx != get_stridx (gimple_phi_arg_def (phi, i), phi)) |
8b57bfeb JJ |
5758 | break; |
5759 | if (i == n) | |
9771b263 | 5760 | ssa_ver_to_stridx[SSA_NAME_VERSION (result)] = idx; |
8b57bfeb JJ |
5761 | } |
5762 | } | |
5763 | } | |
5764 | ||
fa9544ab ML |
5765 | bool cleanup_eh = false; |
5766 | ||
8b57bfeb | 5767 | /* Attempt to optimize individual statements. */ |
47e4ab65 | 5768 | for (m_gsi = gsi_start_bb (bb); !gsi_end_p (m_gsi); ) |
22fca489 | 5769 | { |
d02c41dd MS |
5770 | /* Reset search depth preformance counter. */ |
5771 | ptr_qry.depth = 0; | |
5772 | ||
47e4ab65 AH |
5773 | if (check_and_optimize_stmt (&cleanup_eh)) |
5774 | gsi_next (&m_gsi); | |
22fca489 | 5775 | } |
8b57bfeb | 5776 | |
fa9544ab ML |
5777 | if (cleanup_eh && gimple_purge_dead_eh_edges (bb)) |
5778 | m_cleanup_cfg = true; | |
5779 | ||
8b57bfeb | 5780 | bb->aux = stridx_to_strinfo; |
9771b263 | 5781 | if (vec_safe_length (stridx_to_strinfo) && !strinfo_shared ()) |
526ceb68 | 5782 | (*stridx_to_strinfo)[0] = (strinfo *) bb; |
3daacdcd | 5783 | return NULL; |
8b57bfeb JJ |
5784 | } |
5785 | ||
5786 | /* Callback for walk_dominator_tree. Free strinfo vector if it is | |
5787 | owned by the current bb, clear bb->aux. */ | |
5788 | ||
4d9192b5 | 5789 | void |
47e4ab65 | 5790 | strlen_pass::after_dom_children (basic_block bb) |
8b57bfeb JJ |
5791 | { |
5792 | if (bb->aux) | |
5793 | { | |
526ceb68 | 5794 | stridx_to_strinfo = ((vec<strinfo *, va_heap, vl_embed> *) bb->aux); |
9771b263 | 5795 | if (vec_safe_length (stridx_to_strinfo) |
526ceb68 | 5796 | && (*stridx_to_strinfo)[0] == (strinfo *) bb) |
8b57bfeb JJ |
5797 | { |
5798 | unsigned int i; | |
526ceb68 | 5799 | strinfo *si; |
8b57bfeb | 5800 | |
9771b263 | 5801 | for (i = 1; vec_safe_iterate (stridx_to_strinfo, i, &si); ++i) |
8b57bfeb | 5802 | free_strinfo (si); |
9771b263 | 5803 | vec_free (stridx_to_strinfo); |
8b57bfeb JJ |
5804 | } |
5805 | bb->aux = NULL; | |
5806 | } | |
5807 | } | |
5808 | ||
27a4cd48 DM |
5809 | namespace { |
5810 | ||
22fca489 MS |
5811 | static unsigned int |
5812 | printf_strlen_execute (function *fun, bool warn_only) | |
27a4cd48 | 5813 | { |
22fca489 | 5814 | strlen_optimize = !warn_only; |
27a4cd48 | 5815 | |
be55bfe6 TS |
5816 | calculate_dominance_info (CDI_DOMINATORS); |
5817 | ||
22fca489 MS |
5818 | bool use_scev = optimize > 0 && flag_printf_return_value; |
5819 | if (use_scev) | |
5820 | { | |
5821 | loop_optimizer_init (LOOPS_NORMAL); | |
5822 | scev_initialize (); | |
5823 | } | |
5824 | ||
2d8ba441 JL |
5825 | gcc_assert (!strlen_to_stridx); |
5826 | if (warn_stringop_overflow || warn_stringop_truncation) | |
5827 | strlen_to_stridx = new hash_map<tree, stridx_strlenloc> (); | |
5828 | ||
5829 | /* This has to happen after initializing the loop optimizer | |
5830 | and initializing SCEV as they create new SSA_NAMEs. */ | |
cb3874dc | 5831 | ssa_ver_to_stridx.safe_grow_cleared (num_ssa_names, true); |
2d8ba441 JL |
5832 | max_stridx = 1; |
5833 | ||
be55bfe6 TS |
5834 | /* String length optimization is implemented as a walk of the dominator |
5835 | tree and a forward walk of statements within each block. */ | |
47e4ab65 | 5836 | strlen_pass walker (CDI_DOMINATORS); |
22fca489 | 5837 | walker.walk (ENTRY_BLOCK_PTR_FOR_FN (fun)); |
be55bfe6 | 5838 | |
d02c41dd | 5839 | if (dump_file && (dump_flags & TDF_DETAILS)) |
ba6e17e7 | 5840 | walker.ptr_qry.dump (dump_file, true); |
d02c41dd | 5841 | |
be55bfe6 | 5842 | ssa_ver_to_stridx.release (); |
33e7d32e | 5843 | strinfo_pool.release (); |
c203e8a7 | 5844 | if (decl_to_stridxlist_htab) |
be55bfe6 TS |
5845 | { |
5846 | obstack_free (&stridx_obstack, NULL); | |
c203e8a7 TS |
5847 | delete decl_to_stridxlist_htab; |
5848 | decl_to_stridxlist_htab = NULL; | |
be55bfe6 TS |
5849 | } |
5850 | laststmt.stmt = NULL; | |
5851 | laststmt.len = NULL_TREE; | |
5852 | laststmt.stridx = 0; | |
5853 | ||
6a33d0ff MS |
5854 | if (strlen_to_stridx) |
5855 | { | |
5856 | strlen_to_stridx->empty (); | |
5857 | delete strlen_to_stridx; | |
5858 | strlen_to_stridx = NULL; | |
5859 | } | |
025d57f0 | 5860 | |
22fca489 MS |
5861 | if (use_scev) |
5862 | { | |
5863 | scev_finalize (); | |
5864 | loop_optimizer_finalize (); | |
5865 | } | |
5866 | ||
fa9544ab | 5867 | return walker.m_cleanup_cfg ? TODO_cleanup_cfg : 0; |
be55bfe6 TS |
5868 | } |
5869 | ||
22fca489 MS |
5870 | /* This file defines two passes: one for warnings that runs only when |
5871 | optimization is disabled, and another that implements optimizations | |
5872 | and also issues warnings. */ | |
5873 | ||
5874 | const pass_data pass_data_warn_printf = | |
5875 | { | |
5876 | GIMPLE_PASS, /* type */ | |
5877 | "warn-printf", /* name */ | |
5878 | OPTGROUP_NONE, /* optinfo_flags */ | |
5879 | TV_NONE, /* tv_id */ | |
5880 | /* Normally an optimization pass would require PROP_ssa but because | |
5881 | this pass runs early, with no optimization, to do sprintf format | |
5882 | checking, it only requires PROP_cfg. */ | |
5883 | PROP_cfg, /* properties_required */ | |
5884 | 0, /* properties_provided */ | |
5885 | 0, /* properties_destroyed */ | |
5886 | 0, /* todo_flags_start */ | |
5887 | 0, /* todo_flags_finish */ | |
5888 | }; | |
5889 | ||
5890 | class pass_warn_printf : public gimple_opt_pass | |
5891 | { | |
5892 | public: | |
5893 | pass_warn_printf (gcc::context *ctxt) | |
5894 | : gimple_opt_pass (pass_data_warn_printf, ctxt) | |
5895 | {} | |
5896 | ||
5897 | virtual bool gate (function *); | |
5898 | virtual unsigned int execute (function *fun) | |
5899 | { | |
5900 | return printf_strlen_execute (fun, true); | |
5901 | } | |
5902 | }; | |
5903 | ||
5904 | ||
5905 | /* Return true to run the warning pass only when not optimizing and | |
5906 | iff either -Wformat-overflow or -Wformat-truncation is specified. */ | |
5907 | ||
5908 | bool | |
5909 | pass_warn_printf::gate (function *) | |
5910 | { | |
5911 | return !optimize && (warn_format_overflow > 0 || warn_format_trunc > 0); | |
5912 | } | |
5913 | ||
5914 | const pass_data pass_data_strlen = | |
5915 | { | |
5916 | GIMPLE_PASS, /* type */ | |
5917 | "strlen", /* name */ | |
5918 | OPTGROUP_NONE, /* optinfo_flags */ | |
5919 | TV_TREE_STRLEN, /* tv_id */ | |
5920 | PROP_cfg | PROP_ssa, /* properties_required */ | |
5921 | 0, /* properties_provided */ | |
5922 | 0, /* properties_destroyed */ | |
5923 | 0, /* todo_flags_start */ | |
5924 | 0, /* todo_flags_finish */ | |
5925 | }; | |
5926 | ||
5927 | class pass_strlen : public gimple_opt_pass | |
5928 | { | |
5929 | public: | |
5930 | pass_strlen (gcc::context *ctxt) | |
5931 | : gimple_opt_pass (pass_data_strlen, ctxt) | |
5932 | {} | |
5933 | ||
5934 | opt_pass * clone () { return new pass_strlen (m_ctxt); } | |
5935 | ||
5936 | virtual bool gate (function *); | |
5937 | virtual unsigned int execute (function *fun) | |
5938 | { | |
5939 | return printf_strlen_execute (fun, false); | |
5940 | } | |
5941 | }; | |
5942 | ||
5943 | /* Return true to run the pass only when the sprintf and/or strlen | |
5944 | optimizations are enabled and -Wformat-overflow or -Wformat-truncation | |
5945 | are specified. */ | |
5946 | ||
5947 | bool | |
5948 | pass_strlen::gate (function *) | |
5949 | { | |
5950 | return ((warn_format_overflow > 0 | |
5951 | || warn_format_trunc > 0 | |
937a86b4 | 5952 | || warn_restrict > 0 |
22fca489 MS |
5953 | || flag_optimize_strlen > 0 |
5954 | || flag_printf_return_value) | |
5955 | && optimize > 0); | |
5956 | } | |
5957 | ||
27a4cd48 DM |
5958 | } // anon namespace |
5959 | ||
22fca489 MS |
5960 | gimple_opt_pass * |
5961 | make_pass_warn_printf (gcc::context *ctxt) | |
5962 | { | |
5963 | return new pass_warn_printf (ctxt); | |
5964 | } | |
5965 | ||
27a4cd48 DM |
5966 | gimple_opt_pass * |
5967 | make_pass_strlen (gcc::context *ctxt) | |
5968 | { | |
5969 | return new pass_strlen (ctxt); | |
5970 | } |