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10a0d495 | 1 | /* __builtin_object_size (ptr, object_size_type) computation |
8d9254fc | 2 | Copyright (C) 2004-2020 Free Software Foundation, Inc. |
10a0d495 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 | |
9dcd6f09 | 9 | the Free Software Foundation; either version 3, or (at your option) |
10a0d495 JJ |
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 | |
9dcd6f09 NC |
18 | along with GCC; see the file COPYING3. If not see |
19 | <http://www.gnu.org/licenses/>. */ | |
10a0d495 JJ |
20 | |
21 | #include "config.h" | |
22 | #include "system.h" | |
23 | #include "coretypes.h" | |
c7131fb2 | 24 | #include "backend.h" |
10a0d495 | 25 | #include "tree.h" |
c7131fb2 | 26 | #include "gimple.h" |
957060b5 | 27 | #include "tree-pass.h" |
c7131fb2 | 28 | #include "ssa.h" |
957060b5 | 29 | #include "gimple-pretty-print.h" |
40e23961 | 30 | #include "fold-const.h" |
d8a2d370 | 31 | #include "tree-object-size.h" |
2fb9a547 | 32 | #include "gimple-fold.h" |
5be5c238 | 33 | #include "gimple-iterator.h" |
1e080ab4 | 34 | #include "tree-cfg.h" |
314e6352 ML |
35 | #include "stringpool.h" |
36 | #include "attribs.h" | |
10a0d495 JJ |
37 | |
38 | struct object_size_info | |
39 | { | |
40 | int object_size_type; | |
34e82342 | 41 | unsigned char pass; |
10a0d495 | 42 | bool changed; |
34e82342 | 43 | bitmap visited, reexamine; |
10a0d495 JJ |
44 | unsigned int *depths; |
45 | unsigned int *stack, *tos; | |
46 | }; | |
47 | ||
a43068cc JJ |
48 | static const unsigned HOST_WIDE_INT unknown[4] = { |
49 | HOST_WIDE_INT_M1U, | |
50 | HOST_WIDE_INT_M1U, | |
51 | 0, | |
52 | 0 | |
53 | }; | |
10a0d495 | 54 | |
ac545c64 | 55 | static tree compute_object_offset (const_tree, const_tree); |
05a64756 | 56 | static bool addr_object_size (struct object_size_info *, |
28a5fa54 | 57 | const_tree, int, unsigned HOST_WIDE_INT *, |
f7d86b5c | 58 | tree * = NULL, tree * = NULL); |
538dd0b7 DM |
59 | static unsigned HOST_WIDE_INT alloc_object_size (const gcall *, int); |
60 | static tree pass_through_call (const gcall *); | |
10a0d495 JJ |
61 | static void collect_object_sizes_for (struct object_size_info *, tree); |
62 | static void expr_object_size (struct object_size_info *, tree, tree); | |
63 | static bool merge_object_sizes (struct object_size_info *, tree, tree, | |
64 | unsigned HOST_WIDE_INT); | |
60dd79ca TS |
65 | static bool plus_stmt_object_size (struct object_size_info *, tree, gimple *); |
66 | static bool cond_expr_object_size (struct object_size_info *, tree, gimple *); | |
10a0d495 JJ |
67 | static void init_offset_limit (void); |
68 | static void check_for_plus_in_loops (struct object_size_info *, tree); | |
69 | static void check_for_plus_in_loops_1 (struct object_size_info *, tree, | |
70 | unsigned int); | |
71 | ||
72 | /* object_sizes[0] is upper bound for number of bytes till the end of | |
73 | the object. | |
74 | object_sizes[1] is upper bound for number of bytes till the end of | |
75 | the subobject (innermost array or field with address taken). | |
76 | object_sizes[2] is lower bound for number of bytes till the end of | |
77 | the object and object_sizes[3] lower bound for subobject. */ | |
db84d11e | 78 | static vec<unsigned HOST_WIDE_INT> object_sizes[4]; |
10a0d495 JJ |
79 | |
80 | /* Bitmaps what object sizes have been computed already. */ | |
81 | static bitmap computed[4]; | |
82 | ||
83 | /* Maximum value of offset we consider to be addition. */ | |
84 | static unsigned HOST_WIDE_INT offset_limit; | |
85 | ||
86 | ||
87 | /* Initialize OFFSET_LIMIT variable. */ | |
88 | static void | |
89 | init_offset_limit (void) | |
90 | { | |
cc269bb6 | 91 | if (tree_fits_uhwi_p (TYPE_MAX_VALUE (sizetype))) |
ae7e9ddd | 92 | offset_limit = tree_to_uhwi (TYPE_MAX_VALUE (sizetype)); |
10a0d495 JJ |
93 | else |
94 | offset_limit = -1; | |
95 | offset_limit /= 2; | |
96 | } | |
97 | ||
98 | ||
99 | /* Compute offset of EXPR within VAR. Return error_mark_node | |
100 | if unknown. */ | |
101 | ||
102 | static tree | |
ac545c64 | 103 | compute_object_offset (const_tree expr, const_tree var) |
10a0d495 JJ |
104 | { |
105 | enum tree_code code = PLUS_EXPR; | |
106 | tree base, off, t; | |
107 | ||
108 | if (expr == var) | |
109 | return size_zero_node; | |
110 | ||
111 | switch (TREE_CODE (expr)) | |
112 | { | |
113 | case COMPONENT_REF: | |
114 | base = compute_object_offset (TREE_OPERAND (expr, 0), var); | |
115 | if (base == error_mark_node) | |
116 | return base; | |
117 | ||
118 | t = TREE_OPERAND (expr, 1); | |
119 | off = size_binop (PLUS_EXPR, DECL_FIELD_OFFSET (t), | |
ae7e9ddd | 120 | size_int (tree_to_uhwi (DECL_FIELD_BIT_OFFSET (t)) |
10a0d495 JJ |
121 | / BITS_PER_UNIT)); |
122 | break; | |
123 | ||
124 | case REALPART_EXPR: | |
1043771b | 125 | CASE_CONVERT: |
10a0d495 JJ |
126 | case VIEW_CONVERT_EXPR: |
127 | case NON_LVALUE_EXPR: | |
128 | return compute_object_offset (TREE_OPERAND (expr, 0), var); | |
129 | ||
130 | case IMAGPART_EXPR: | |
131 | base = compute_object_offset (TREE_OPERAND (expr, 0), var); | |
132 | if (base == error_mark_node) | |
133 | return base; | |
134 | ||
135 | off = TYPE_SIZE_UNIT (TREE_TYPE (expr)); | |
136 | break; | |
137 | ||
138 | case ARRAY_REF: | |
139 | base = compute_object_offset (TREE_OPERAND (expr, 0), var); | |
140 | if (base == error_mark_node) | |
141 | return base; | |
142 | ||
143 | t = TREE_OPERAND (expr, 1); | |
2d4102c5 JJ |
144 | tree low_bound, unit_size; |
145 | low_bound = array_ref_low_bound (CONST_CAST_TREE (expr)); | |
146 | unit_size = array_ref_element_size (CONST_CAST_TREE (expr)); | |
147 | if (! integer_zerop (low_bound)) | |
148 | t = fold_build2 (MINUS_EXPR, TREE_TYPE (t), t, low_bound); | |
10a0d495 JJ |
149 | if (TREE_CODE (t) == INTEGER_CST && tree_int_cst_sgn (t) < 0) |
150 | { | |
151 | code = MINUS_EXPR; | |
152 | t = fold_build1 (NEGATE_EXPR, TREE_TYPE (t), t); | |
153 | } | |
b6f65e3c | 154 | t = fold_convert (sizetype, t); |
2d4102c5 | 155 | off = size_binop (MULT_EXPR, unit_size, t); |
10a0d495 JJ |
156 | break; |
157 | ||
70f34814 RG |
158 | case MEM_REF: |
159 | gcc_assert (TREE_CODE (TREE_OPERAND (expr, 0)) == ADDR_EXPR); | |
807e902e | 160 | return wide_int_to_tree (sizetype, mem_ref_offset (expr)); |
70f34814 | 161 | |
10a0d495 JJ |
162 | default: |
163 | return error_mark_node; | |
164 | } | |
165 | ||
166 | return size_binop (code, base, off); | |
167 | } | |
168 | ||
7a41fcde MS |
169 | /* Returns the size of the object designated by DECL considering its |
170 | initializer if it either has one or if it would not affect its size, | |
171 | otherwise the size of the object without the initializer when MIN | |
172 | is true, else null. An object's initializer affects the object's | |
173 | size if it's a struct type with a flexible array member. */ | |
174 | ||
175 | static tree | |
176 | decl_init_size (tree decl, bool min) | |
177 | { | |
178 | tree size = DECL_SIZE_UNIT (decl); | |
179 | tree type = TREE_TYPE (decl); | |
180 | if (TREE_CODE (type) != RECORD_TYPE) | |
181 | return size; | |
182 | ||
183 | tree last = last_field (type); | |
184 | if (!last) | |
185 | return size; | |
186 | ||
187 | tree last_type = TREE_TYPE (last); | |
188 | if (TREE_CODE (last_type) != ARRAY_TYPE | |
189 | || TYPE_SIZE (last_type)) | |
190 | return size; | |
191 | ||
192 | /* Use TYPE_SIZE_UNIT; DECL_SIZE_UNIT sometimes reflects the size | |
193 | of the initializer and sometimes doesn't. */ | |
194 | size = TYPE_SIZE_UNIT (type); | |
195 | tree ref = build3 (COMPONENT_REF, type, decl, last, NULL_TREE); | |
196 | tree compsize = component_ref_size (ref); | |
197 | if (!compsize) | |
198 | return min ? size : NULL_TREE; | |
199 | ||
200 | /* The size includes tail padding and initializer elements. */ | |
201 | tree pos = byte_position (last); | |
202 | size = fold_build2 (PLUS_EXPR, TREE_TYPE (size), pos, compsize); | |
203 | return size; | |
204 | } | |
10a0d495 JJ |
205 | |
206 | /* Compute __builtin_object_size for PTR, which is a ADDR_EXPR. | |
207 | OBJECT_SIZE_TYPE is the second argument from __builtin_object_size. | |
208 | If unknown, return unknown[object_size_type]. */ | |
209 | ||
05a64756 | 210 | static bool |
eb9ed98a | 211 | addr_object_size (struct object_size_info *osi, const_tree ptr, |
28a5fa54 | 212 | int object_size_type, unsigned HOST_WIDE_INT *psize, |
f7d86b5c | 213 | tree *pdecl /* = NULL */, tree *poff /* = NULL */) |
10a0d495 | 214 | { |
eb9ed98a | 215 | tree pt_var, pt_var_size = NULL_TREE, var_size, bytes; |
10a0d495 | 216 | |
f7d86b5c | 217 | tree dummy_decl, dummy_off = size_zero_node; |
28a5fa54 | 218 | if (!pdecl) |
f7d86b5c MS |
219 | pdecl = &dummy_decl; |
220 | if (!poff) | |
221 | poff = &dummy_off; | |
28a5fa54 | 222 | |
10a0d495 JJ |
223 | gcc_assert (TREE_CODE (ptr) == ADDR_EXPR); |
224 | ||
05a64756 MS |
225 | /* Set to unknown and overwrite just before returning if the size |
226 | could be determined. */ | |
227 | *psize = unknown[object_size_type]; | |
228 | ||
10a0d495 | 229 | pt_var = TREE_OPERAND (ptr, 0); |
d837d73d RG |
230 | while (handled_component_p (pt_var)) |
231 | pt_var = TREE_OPERAND (pt_var, 0); | |
10a0d495 | 232 | |
7a41fcde MS |
233 | if (!pt_var) |
234 | return false; | |
235 | ||
236 | if (TREE_CODE (pt_var) == MEM_REF) | |
10a0d495 | 237 | { |
eb9ed98a | 238 | unsigned HOST_WIDE_INT sz; |
10a0d495 | 239 | |
d837d73d | 240 | if (!osi || (object_size_type & 1) != 0 |
ea17de23 | 241 | || TREE_CODE (TREE_OPERAND (pt_var, 0)) != SSA_NAME) |
70f34814 | 242 | { |
05a64756 | 243 | compute_builtin_object_size (TREE_OPERAND (pt_var, 0), |
f7d86b5c | 244 | object_size_type & ~1, &sz, pdecl, poff); |
70f34814 | 245 | } |
eb9ed98a | 246 | else |
10a0d495 | 247 | { |
eb9ed98a JJ |
248 | tree var = TREE_OPERAND (pt_var, 0); |
249 | if (osi->pass == 0) | |
250 | collect_object_sizes_for (osi, var); | |
251 | if (bitmap_bit_p (computed[object_size_type], | |
252 | SSA_NAME_VERSION (var))) | |
253 | sz = object_sizes[object_size_type][SSA_NAME_VERSION (var)]; | |
254 | else | |
255 | sz = unknown[object_size_type]; | |
d837d73d RG |
256 | } |
257 | if (sz != unknown[object_size_type]) | |
258 | { | |
aca52e6f RS |
259 | offset_int mem_offset; |
260 | if (mem_ref_offset (pt_var).is_constant (&mem_offset)) | |
261 | { | |
262 | offset_int dsz = wi::sub (sz, mem_offset); | |
263 | if (wi::neg_p (dsz)) | |
264 | sz = 0; | |
265 | else if (wi::fits_uhwi_p (dsz)) | |
266 | sz = dsz.to_uhwi (); | |
267 | else | |
268 | sz = unknown[object_size_type]; | |
269 | } | |
70f34814 | 270 | else |
d837d73d | 271 | sz = unknown[object_size_type]; |
eb9ed98a JJ |
272 | } |
273 | ||
274 | if (sz != unknown[object_size_type] && sz < offset_limit) | |
275 | pt_var_size = size_int (sz); | |
276 | } | |
7a41fcde | 277 | else if (DECL_P (pt_var)) |
28a5fa54 MS |
278 | { |
279 | *pdecl = pt_var; | |
7a41fcde MS |
280 | pt_var_size = decl_init_size (pt_var, object_size_type & 2); |
281 | if (!pt_var_size) | |
282 | return false; | |
28a5fa54 | 283 | } |
7a41fcde | 284 | else if (TREE_CODE (pt_var) == STRING_CST) |
eb9ed98a JJ |
285 | pt_var_size = TYPE_SIZE_UNIT (TREE_TYPE (pt_var)); |
286 | else | |
05a64756 | 287 | return false; |
eb9ed98a | 288 | |
7a41fcde MS |
289 | if (pt_var_size) |
290 | { | |
291 | /* Validate the size determined above. */ | |
292 | if (!tree_fits_uhwi_p (pt_var_size) | |
293 | || tree_to_uhwi (pt_var_size) >= offset_limit) | |
294 | return false; | |
295 | } | |
296 | ||
eb9ed98a JJ |
297 | if (pt_var != TREE_OPERAND (ptr, 0)) |
298 | { | |
299 | tree var; | |
10a0d495 | 300 | |
eb9ed98a JJ |
301 | if (object_size_type & 1) |
302 | { | |
303 | var = TREE_OPERAND (ptr, 0); | |
304 | ||
305 | while (var != pt_var | |
306 | && TREE_CODE (var) != BIT_FIELD_REF | |
307 | && TREE_CODE (var) != COMPONENT_REF | |
308 | && TREE_CODE (var) != ARRAY_REF | |
309 | && TREE_CODE (var) != ARRAY_RANGE_REF | |
310 | && TREE_CODE (var) != REALPART_EXPR | |
311 | && TREE_CODE (var) != IMAGPART_EXPR) | |
312 | var = TREE_OPERAND (var, 0); | |
313 | if (var != pt_var && TREE_CODE (var) == ARRAY_REF) | |
38027156 | 314 | var = TREE_OPERAND (var, 0); |
eb9ed98a | 315 | if (! TYPE_SIZE_UNIT (TREE_TYPE (var)) |
cc269bb6 | 316 | || ! tree_fits_uhwi_p (TYPE_SIZE_UNIT (TREE_TYPE (var))) |
eb9ed98a JJ |
317 | || (pt_var_size |
318 | && tree_int_cst_lt (pt_var_size, | |
319 | TYPE_SIZE_UNIT (TREE_TYPE (var))))) | |
320 | var = pt_var; | |
70f34814 | 321 | else if (var != pt_var && TREE_CODE (pt_var) == MEM_REF) |
10a0d495 | 322 | { |
eb9ed98a JJ |
323 | tree v = var; |
324 | /* For &X->fld, compute object size only if fld isn't the last | |
325 | field, as struct { int i; char c[1]; } is often used instead | |
326 | of flexible array member. */ | |
327 | while (v && v != pt_var) | |
328 | switch (TREE_CODE (v)) | |
329 | { | |
330 | case ARRAY_REF: | |
331 | if (TYPE_SIZE_UNIT (TREE_TYPE (TREE_OPERAND (v, 0))) | |
332 | && TREE_CODE (TREE_OPERAND (v, 1)) == INTEGER_CST) | |
333 | { | |
334 | tree domain | |
335 | = TYPE_DOMAIN (TREE_TYPE (TREE_OPERAND (v, 0))); | |
336 | if (domain | |
337 | && TYPE_MAX_VALUE (domain) | |
338 | && TREE_CODE (TYPE_MAX_VALUE (domain)) | |
339 | == INTEGER_CST | |
340 | && tree_int_cst_lt (TREE_OPERAND (v, 1), | |
341 | TYPE_MAX_VALUE (domain))) | |
342 | { | |
343 | v = NULL_TREE; | |
344 | break; | |
345 | } | |
346 | } | |
347 | v = TREE_OPERAND (v, 0); | |
348 | break; | |
349 | case REALPART_EXPR: | |
350 | case IMAGPART_EXPR: | |
351 | v = NULL_TREE; | |
352 | break; | |
353 | case COMPONENT_REF: | |
8593e0b6 JJ |
354 | if (TREE_CODE (TREE_TYPE (v)) != ARRAY_TYPE) |
355 | { | |
356 | v = NULL_TREE; | |
357 | break; | |
358 | } | |
38027156 JJ |
359 | while (v != pt_var && TREE_CODE (v) == COMPONENT_REF) |
360 | if (TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0))) | |
361 | != UNION_TYPE | |
362 | && TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0))) | |
363 | != QUAL_UNION_TYPE) | |
364 | break; | |
365 | else | |
366 | v = TREE_OPERAND (v, 0); | |
367 | if (TREE_CODE (v) == COMPONENT_REF | |
368 | && TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0))) | |
369 | == RECORD_TYPE) | |
eb9ed98a | 370 | { |
910ad8de NF |
371 | tree fld_chain = DECL_CHAIN (TREE_OPERAND (v, 1)); |
372 | for (; fld_chain; fld_chain = DECL_CHAIN (fld_chain)) | |
8593e0b6 JJ |
373 | if (TREE_CODE (fld_chain) == FIELD_DECL) |
374 | break; | |
375 | ||
376 | if (fld_chain) | |
377 | { | |
378 | v = NULL_TREE; | |
eb9ed98a | 379 | break; |
8593e0b6 | 380 | } |
38027156 | 381 | v = TREE_OPERAND (v, 0); |
eb9ed98a | 382 | } |
38027156 JJ |
383 | while (v != pt_var && TREE_CODE (v) == COMPONENT_REF) |
384 | if (TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0))) | |
385 | != UNION_TYPE | |
386 | && TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0))) | |
387 | != QUAL_UNION_TYPE) | |
8593e0b6 JJ |
388 | break; |
389 | else | |
390 | v = TREE_OPERAND (v, 0); | |
38027156 | 391 | if (v != pt_var) |
8593e0b6 JJ |
392 | v = NULL_TREE; |
393 | else | |
394 | v = pt_var; | |
eb9ed98a JJ |
395 | break; |
396 | default: | |
397 | v = pt_var; | |
398 | break; | |
399 | } | |
400 | if (v == pt_var) | |
10a0d495 JJ |
401 | var = pt_var; |
402 | } | |
eb9ed98a JJ |
403 | } |
404 | else | |
405 | var = pt_var; | |
10a0d495 | 406 | |
eb9ed98a JJ |
407 | if (var != pt_var) |
408 | var_size = TYPE_SIZE_UNIT (TREE_TYPE (var)); | |
409 | else if (!pt_var_size) | |
05a64756 | 410 | return false; |
eb9ed98a JJ |
411 | else |
412 | var_size = pt_var_size; | |
413 | bytes = compute_object_offset (TREE_OPERAND (ptr, 0), var); | |
414 | if (bytes != error_mark_node) | |
415 | { | |
416 | if (TREE_CODE (bytes) == INTEGER_CST | |
417 | && tree_int_cst_lt (var_size, bytes)) | |
418 | bytes = size_zero_node; | |
419 | else | |
420 | bytes = size_binop (MINUS_EXPR, var_size, bytes); | |
f7d86b5c | 421 | *poff = bytes; |
eb9ed98a JJ |
422 | } |
423 | if (var != pt_var | |
424 | && pt_var_size | |
70f34814 | 425 | && TREE_CODE (pt_var) == MEM_REF |
eb9ed98a JJ |
426 | && bytes != error_mark_node) |
427 | { | |
428 | tree bytes2 = compute_object_offset (TREE_OPERAND (ptr, 0), pt_var); | |
429 | if (bytes2 != error_mark_node) | |
10a0d495 | 430 | { |
eb9ed98a JJ |
431 | if (TREE_CODE (bytes2) == INTEGER_CST |
432 | && tree_int_cst_lt (pt_var_size, bytes2)) | |
433 | bytes2 = size_zero_node; | |
10a0d495 | 434 | else |
98a129b9 | 435 | bytes2 = size_binop (MINUS_EXPR, pt_var_size, bytes2); |
f7d86b5c | 436 | *poff = size_binop (PLUS_EXPR, *poff, bytes2); |
eb9ed98a | 437 | bytes = size_binop (MIN_EXPR, bytes, bytes2); |
10a0d495 JJ |
438 | } |
439 | } | |
10a0d495 | 440 | } |
eb9ed98a | 441 | else if (!pt_var_size) |
05a64756 | 442 | return false; |
eb9ed98a JJ |
443 | else |
444 | bytes = pt_var_size; | |
445 | ||
cc269bb6 | 446 | if (tree_fits_uhwi_p (bytes)) |
05a64756 MS |
447 | { |
448 | *psize = tree_to_uhwi (bytes); | |
449 | return true; | |
450 | } | |
10a0d495 | 451 | |
05a64756 | 452 | return false; |
10a0d495 JJ |
453 | } |
454 | ||
455 | ||
726a989a | 456 | /* Compute __builtin_object_size for CALL, which is a GIMPLE_CALL. |
302db8ba MS |
457 | Handles calls to functions declared with attribute alloc_size. |
458 | OBJECT_SIZE_TYPE is the second argument from __builtin_object_size. | |
459 | If unknown, return unknown[object_size_type]. */ | |
10a0d495 JJ |
460 | |
461 | static unsigned HOST_WIDE_INT | |
538dd0b7 | 462 | alloc_object_size (const gcall *call, int object_size_type) |
10a0d495 | 463 | { |
726a989a | 464 | gcc_assert (is_gimple_call (call)); |
10a0d495 | 465 | |
302db8ba MS |
466 | tree calltype; |
467 | if (tree callfn = gimple_call_fndecl (call)) | |
468 | calltype = TREE_TYPE (callfn); | |
469 | else | |
470 | calltype = gimple_call_fntype (call); | |
471 | ||
472 | if (!calltype) | |
51bc54a6 DM |
473 | return unknown[object_size_type]; |
474 | ||
302db8ba MS |
475 | /* Set to positions of alloc_size arguments. */ |
476 | int arg1 = -1, arg2 = -1; | |
477 | tree alloc_size = lookup_attribute ("alloc_size", | |
478 | TYPE_ATTRIBUTES (calltype)); | |
51bc54a6 DM |
479 | if (alloc_size && TREE_VALUE (alloc_size)) |
480 | { | |
481 | tree p = TREE_VALUE (alloc_size); | |
482 | ||
483 | arg1 = TREE_INT_CST_LOW (TREE_VALUE (p))-1; | |
484 | if (TREE_CHAIN (p)) | |
726a989a | 485 | arg2 = TREE_INT_CST_LOW (TREE_VALUE (TREE_CHAIN (p)))-1; |
51bc54a6 | 486 | } |
b8698a0f | 487 | |
726a989a RB |
488 | if (arg1 < 0 || arg1 >= (int)gimple_call_num_args (call) |
489 | || TREE_CODE (gimple_call_arg (call, arg1)) != INTEGER_CST | |
b8698a0f | 490 | || (arg2 >= 0 |
726a989a RB |
491 | && (arg2 >= (int)gimple_call_num_args (call) |
492 | || TREE_CODE (gimple_call_arg (call, arg2)) != INTEGER_CST))) | |
b8698a0f | 493 | return unknown[object_size_type]; |
51bc54a6 | 494 | |
302db8ba | 495 | tree bytes = NULL_TREE; |
51bc54a6 DM |
496 | if (arg2 >= 0) |
497 | bytes = size_binop (MULT_EXPR, | |
726a989a RB |
498 | fold_convert (sizetype, gimple_call_arg (call, arg1)), |
499 | fold_convert (sizetype, gimple_call_arg (call, arg2))); | |
51bc54a6 | 500 | else if (arg1 >= 0) |
726a989a | 501 | bytes = fold_convert (sizetype, gimple_call_arg (call, arg1)); |
51bc54a6 | 502 | |
cc269bb6 | 503 | if (bytes && tree_fits_uhwi_p (bytes)) |
ae7e9ddd | 504 | return tree_to_uhwi (bytes); |
10a0d495 JJ |
505 | |
506 | return unknown[object_size_type]; | |
507 | } | |
508 | ||
509 | ||
510 | /* If object size is propagated from one of function's arguments directly | |
726a989a | 511 | to its return value, return that argument for GIMPLE_CALL statement CALL. |
10a0d495 JJ |
512 | Otherwise return NULL. */ |
513 | ||
514 | static tree | |
538dd0b7 | 515 | pass_through_call (const gcall *call) |
10a0d495 | 516 | { |
51feb980 JJ |
517 | unsigned rf = gimple_call_return_flags (call); |
518 | if (rf & ERF_RETURNS_ARG) | |
519 | { | |
520 | unsigned argnum = rf & ERF_RETURN_ARG_MASK; | |
521 | if (argnum < gimple_call_num_args (call)) | |
522 | return gimple_call_arg (call, argnum); | |
523 | } | |
10a0d495 | 524 | |
51feb980 JJ |
525 | /* __builtin_assume_aligned is intentionally not marked RET1. */ |
526 | if (gimple_call_builtin_p (call, BUILT_IN_ASSUME_ALIGNED)) | |
527 | return gimple_call_arg (call, 0); | |
10a0d495 JJ |
528 | |
529 | return NULL_TREE; | |
530 | } | |
531 | ||
532 | ||
05a64756 | 533 | /* Compute __builtin_object_size value for PTR and set *PSIZE to |
28a5fa54 MS |
534 | the resulting value. If the declared object is known and PDECL |
535 | is nonnull, sets *PDECL to the object's DECL. OBJECT_SIZE_TYPE | |
536 | is the second argument to __builtin_object_size. | |
537 | Returns true on success and false when the object size could not | |
538 | be determined. */ | |
10a0d495 | 539 | |
05a64756 MS |
540 | bool |
541 | compute_builtin_object_size (tree ptr, int object_size_type, | |
28a5fa54 | 542 | unsigned HOST_WIDE_INT *psize, |
f7d86b5c | 543 | tree *pdecl /* = NULL */, tree *poff /* = NULL */) |
10a0d495 JJ |
544 | { |
545 | gcc_assert (object_size_type >= 0 && object_size_type <= 3); | |
546 | ||
f7d86b5c MS |
547 | tree dummy_decl, dummy_off = size_zero_node; |
548 | if (!pdecl) | |
549 | pdecl = &dummy_decl; | |
550 | if (!poff) | |
551 | poff = &dummy_off; | |
552 | ||
05a64756 MS |
553 | /* Set to unknown and overwrite just before returning if the size |
554 | could be determined. */ | |
555 | *psize = unknown[object_size_type]; | |
556 | ||
10a0d495 JJ |
557 | if (! offset_limit) |
558 | init_offset_limit (); | |
559 | ||
560 | if (TREE_CODE (ptr) == ADDR_EXPR) | |
f7d86b5c | 561 | return addr_object_size (NULL, ptr, object_size_type, psize, pdecl, poff); |
05a64756 MS |
562 | |
563 | if (TREE_CODE (ptr) != SSA_NAME | |
564 | || !POINTER_TYPE_P (TREE_TYPE (ptr))) | |
565 | return false; | |
10a0d495 | 566 | |
05a64756 | 567 | if (computed[object_size_type] == NULL) |
10a0d495 | 568 | { |
05a64756 MS |
569 | if (optimize || object_size_type & 1) |
570 | return false; | |
571 | ||
572 | /* When not optimizing, rather than failing, make a small effort | |
573 | to determine the object size without the full benefit of | |
574 | the (costly) computation below. */ | |
575 | gimple *def = SSA_NAME_DEF_STMT (ptr); | |
576 | if (gimple_code (def) == GIMPLE_ASSIGN) | |
10a0d495 | 577 | { |
05a64756 MS |
578 | tree_code code = gimple_assign_rhs_code (def); |
579 | if (code == POINTER_PLUS_EXPR) | |
10a0d495 | 580 | { |
05a64756 MS |
581 | tree offset = gimple_assign_rhs2 (def); |
582 | ptr = gimple_assign_rhs1 (def); | |
10a0d495 | 583 | |
6182121c | 584 | if (tree_fits_shwi_p (offset) |
28a5fa54 | 585 | && compute_builtin_object_size (ptr, object_size_type, |
f7d86b5c | 586 | psize, pdecl, poff)) |
10a0d495 | 587 | { |
05a64756 MS |
588 | /* Return zero when the offset is out of bounds. */ |
589 | unsigned HOST_WIDE_INT off = tree_to_shwi (offset); | |
590 | *psize = off < *psize ? *psize - off : 0; | |
f7d86b5c | 591 | *poff = offset; |
05a64756 | 592 | return true; |
10a0d495 | 593 | } |
05a64756 MS |
594 | } |
595 | } | |
596 | return false; | |
597 | } | |
10a0d495 | 598 | |
05a64756 MS |
599 | if (!bitmap_bit_p (computed[object_size_type], SSA_NAME_VERSION (ptr))) |
600 | { | |
601 | struct object_size_info osi; | |
602 | bitmap_iterator bi; | |
603 | unsigned int i; | |
604 | ||
605 | if (num_ssa_names > object_sizes[object_size_type].length ()) | |
606 | object_sizes[object_size_type].safe_grow (num_ssa_names); | |
607 | if (dump_file) | |
608 | { | |
609 | fprintf (dump_file, "Computing %s %sobject size for ", | |
610 | (object_size_type & 2) ? "minimum" : "maximum", | |
611 | (object_size_type & 1) ? "sub" : ""); | |
612 | print_generic_expr (dump_file, ptr, dump_flags); | |
613 | fprintf (dump_file, ":\n"); | |
614 | } | |
10a0d495 | 615 | |
05a64756 MS |
616 | osi.visited = BITMAP_ALLOC (NULL); |
617 | osi.reexamine = BITMAP_ALLOC (NULL); | |
618 | osi.object_size_type = object_size_type; | |
619 | osi.depths = NULL; | |
620 | osi.stack = NULL; | |
621 | osi.tos = NULL; | |
622 | ||
623 | /* First pass: walk UD chains, compute object sizes that | |
624 | can be computed. osi.reexamine bitmap at the end will | |
625 | contain what variables were found in dependency cycles | |
626 | and therefore need to be reexamined. */ | |
627 | osi.pass = 0; | |
628 | osi.changed = false; | |
629 | collect_object_sizes_for (&osi, ptr); | |
630 | ||
631 | /* Second pass: keep recomputing object sizes of variables | |
632 | that need reexamination, until no object sizes are | |
633 | increased or all object sizes are computed. */ | |
634 | if (! bitmap_empty_p (osi.reexamine)) | |
635 | { | |
636 | bitmap reexamine = BITMAP_ALLOC (NULL); | |
637 | ||
638 | /* If looking for minimum instead of maximum object size, | |
639 | detect cases where a pointer is increased in a loop. | |
640 | Although even without this detection pass 2 would eventually | |
641 | terminate, it could take a long time. If a pointer is | |
642 | increasing this way, we need to assume 0 object size. | |
643 | E.g. p = &buf[0]; while (cond) p = p + 4; */ | |
644 | if (object_size_type & 2) | |
645 | { | |
646 | osi.depths = XCNEWVEC (unsigned int, num_ssa_names); | |
647 | osi.stack = XNEWVEC (unsigned int, num_ssa_names); | |
648 | osi.tos = osi.stack; | |
649 | osi.pass = 1; | |
650 | /* collect_object_sizes_for is changing | |
651 | osi.reexamine bitmap, so iterate over a copy. */ | |
652 | bitmap_copy (reexamine, osi.reexamine); | |
653 | EXECUTE_IF_SET_IN_BITMAP (reexamine, 0, i, bi) | |
654 | if (bitmap_bit_p (osi.reexamine, i)) | |
655 | check_for_plus_in_loops (&osi, ssa_name (i)); | |
656 | ||
657 | free (osi.depths); | |
658 | osi.depths = NULL; | |
659 | free (osi.stack); | |
660 | osi.stack = NULL; | |
661 | osi.tos = NULL; | |
10a0d495 | 662 | } |
10a0d495 | 663 | |
05a64756 | 664 | do |
10a0d495 | 665 | { |
05a64756 MS |
666 | osi.pass = 2; |
667 | osi.changed = false; | |
668 | /* collect_object_sizes_for is changing | |
669 | osi.reexamine bitmap, so iterate over a copy. */ | |
670 | bitmap_copy (reexamine, osi.reexamine); | |
671 | EXECUTE_IF_SET_IN_BITMAP (reexamine, 0, i, bi) | |
672 | if (bitmap_bit_p (osi.reexamine, i)) | |
10a0d495 | 673 | { |
05a64756 MS |
674 | collect_object_sizes_for (&osi, ssa_name (i)); |
675 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
676 | { | |
677 | fprintf (dump_file, "Reexamining "); | |
678 | print_generic_expr (dump_file, ssa_name (i), | |
679 | dump_flags); | |
680 | fprintf (dump_file, "\n"); | |
681 | } | |
10a0d495 JJ |
682 | } |
683 | } | |
05a64756 | 684 | while (osi.changed); |
10a0d495 | 685 | |
05a64756 | 686 | BITMAP_FREE (reexamine); |
10a0d495 | 687 | } |
05a64756 MS |
688 | EXECUTE_IF_SET_IN_BITMAP (osi.reexamine, 0, i, bi) |
689 | bitmap_set_bit (computed[object_size_type], i); | |
10a0d495 | 690 | |
05a64756 MS |
691 | /* Debugging dumps. */ |
692 | if (dump_file) | |
693 | { | |
694 | EXECUTE_IF_SET_IN_BITMAP (osi.visited, 0, i, bi) | |
695 | if (object_sizes[object_size_type][i] | |
696 | != unknown[object_size_type]) | |
697 | { | |
698 | print_generic_expr (dump_file, ssa_name (i), | |
699 | dump_flags); | |
700 | fprintf (dump_file, | |
701 | ": %s %sobject size " | |
702 | HOST_WIDE_INT_PRINT_UNSIGNED "\n", | |
703 | (object_size_type & 2) ? "minimum" : "maximum", | |
704 | (object_size_type & 1) ? "sub" : "", | |
705 | object_sizes[object_size_type][i]); | |
706 | } | |
707 | } | |
708 | ||
709 | BITMAP_FREE (osi.reexamine); | |
710 | BITMAP_FREE (osi.visited); | |
10a0d495 JJ |
711 | } |
712 | ||
05a64756 MS |
713 | *psize = object_sizes[object_size_type][SSA_NAME_VERSION (ptr)]; |
714 | return *psize != unknown[object_size_type]; | |
10a0d495 JJ |
715 | } |
716 | ||
726a989a | 717 | /* Compute object_sizes for PTR, defined to VALUE, which is not an SSA_NAME. */ |
10a0d495 JJ |
718 | |
719 | static void | |
720 | expr_object_size (struct object_size_info *osi, tree ptr, tree value) | |
721 | { | |
722 | int object_size_type = osi->object_size_type; | |
723 | unsigned int varno = SSA_NAME_VERSION (ptr); | |
724 | unsigned HOST_WIDE_INT bytes; | |
725 | ||
726 | gcc_assert (object_sizes[object_size_type][varno] | |
727 | != unknown[object_size_type]); | |
728 | gcc_assert (osi->pass == 0); | |
729 | ||
730 | if (TREE_CODE (value) == WITH_SIZE_EXPR) | |
731 | value = TREE_OPERAND (value, 0); | |
732 | ||
733 | /* Pointer variables should have been handled by merge_object_sizes. */ | |
734 | gcc_assert (TREE_CODE (value) != SSA_NAME | |
735 | || !POINTER_TYPE_P (TREE_TYPE (value))); | |
736 | ||
737 | if (TREE_CODE (value) == ADDR_EXPR) | |
05a64756 | 738 | addr_object_size (osi, value, object_size_type, &bytes); |
10a0d495 JJ |
739 | else |
740 | bytes = unknown[object_size_type]; | |
741 | ||
742 | if ((object_size_type & 2) == 0) | |
743 | { | |
744 | if (object_sizes[object_size_type][varno] < bytes) | |
745 | object_sizes[object_size_type][varno] = bytes; | |
746 | } | |
747 | else | |
748 | { | |
749 | if (object_sizes[object_size_type][varno] > bytes) | |
750 | object_sizes[object_size_type][varno] = bytes; | |
751 | } | |
752 | } | |
753 | ||
754 | ||
726a989a RB |
755 | /* Compute object_sizes for PTR, defined to the result of a call. */ |
756 | ||
757 | static void | |
538dd0b7 | 758 | call_object_size (struct object_size_info *osi, tree ptr, gcall *call) |
726a989a RB |
759 | { |
760 | int object_size_type = osi->object_size_type; | |
761 | unsigned int varno = SSA_NAME_VERSION (ptr); | |
762 | unsigned HOST_WIDE_INT bytes; | |
763 | ||
764 | gcc_assert (is_gimple_call (call)); | |
765 | ||
766 | gcc_assert (object_sizes[object_size_type][varno] | |
767 | != unknown[object_size_type]); | |
768 | gcc_assert (osi->pass == 0); | |
769 | ||
770 | bytes = alloc_object_size (call, object_size_type); | |
771 | ||
772 | if ((object_size_type & 2) == 0) | |
773 | { | |
774 | if (object_sizes[object_size_type][varno] < bytes) | |
775 | object_sizes[object_size_type][varno] = bytes; | |
776 | } | |
777 | else | |
778 | { | |
779 | if (object_sizes[object_size_type][varno] > bytes) | |
780 | object_sizes[object_size_type][varno] = bytes; | |
781 | } | |
782 | } | |
783 | ||
784 | ||
785 | /* Compute object_sizes for PTR, defined to an unknown value. */ | |
786 | ||
787 | static void | |
788 | unknown_object_size (struct object_size_info *osi, tree ptr) | |
789 | { | |
790 | int object_size_type = osi->object_size_type; | |
791 | unsigned int varno = SSA_NAME_VERSION (ptr); | |
792 | unsigned HOST_WIDE_INT bytes; | |
793 | ||
794 | gcc_assert (object_sizes[object_size_type][varno] | |
795 | != unknown[object_size_type]); | |
796 | gcc_assert (osi->pass == 0); | |
797 | ||
798 | bytes = unknown[object_size_type]; | |
799 | ||
800 | if ((object_size_type & 2) == 0) | |
801 | { | |
802 | if (object_sizes[object_size_type][varno] < bytes) | |
803 | object_sizes[object_size_type][varno] = bytes; | |
804 | } | |
805 | else | |
806 | { | |
807 | if (object_sizes[object_size_type][varno] > bytes) | |
808 | object_sizes[object_size_type][varno] = bytes; | |
809 | } | |
810 | } | |
811 | ||
812 | ||
10a0d495 JJ |
813 | /* Merge object sizes of ORIG + OFFSET into DEST. Return true if |
814 | the object size might need reexamination later. */ | |
815 | ||
816 | static bool | |
817 | merge_object_sizes (struct object_size_info *osi, tree dest, tree orig, | |
818 | unsigned HOST_WIDE_INT offset) | |
819 | { | |
820 | int object_size_type = osi->object_size_type; | |
821 | unsigned int varno = SSA_NAME_VERSION (dest); | |
822 | unsigned HOST_WIDE_INT orig_bytes; | |
823 | ||
824 | if (object_sizes[object_size_type][varno] == unknown[object_size_type]) | |
825 | return false; | |
826 | if (offset >= offset_limit) | |
827 | { | |
828 | object_sizes[object_size_type][varno] = unknown[object_size_type]; | |
829 | return false; | |
830 | } | |
831 | ||
832 | if (osi->pass == 0) | |
833 | collect_object_sizes_for (osi, orig); | |
834 | ||
835 | orig_bytes = object_sizes[object_size_type][SSA_NAME_VERSION (orig)]; | |
836 | if (orig_bytes != unknown[object_size_type]) | |
837 | orig_bytes = (offset > orig_bytes) | |
07e96250 | 838 | ? HOST_WIDE_INT_0U : orig_bytes - offset; |
10a0d495 JJ |
839 | |
840 | if ((object_size_type & 2) == 0) | |
841 | { | |
842 | if (object_sizes[object_size_type][varno] < orig_bytes) | |
843 | { | |
844 | object_sizes[object_size_type][varno] = orig_bytes; | |
845 | osi->changed = true; | |
846 | } | |
847 | } | |
848 | else | |
849 | { | |
850 | if (object_sizes[object_size_type][varno] > orig_bytes) | |
851 | { | |
852 | object_sizes[object_size_type][varno] = orig_bytes; | |
853 | osi->changed = true; | |
854 | } | |
855 | } | |
856 | return bitmap_bit_p (osi->reexamine, SSA_NAME_VERSION (orig)); | |
857 | } | |
858 | ||
859 | ||
726a989a RB |
860 | /* Compute object_sizes for VAR, defined to the result of an assignment |
861 | with operator POINTER_PLUS_EXPR. Return true if the object size might | |
862 | need reexamination later. */ | |
10a0d495 JJ |
863 | |
864 | static bool | |
355fe088 | 865 | plus_stmt_object_size (struct object_size_info *osi, tree var, gimple *stmt) |
10a0d495 | 866 | { |
10a0d495 JJ |
867 | int object_size_type = osi->object_size_type; |
868 | unsigned int varno = SSA_NAME_VERSION (var); | |
869 | unsigned HOST_WIDE_INT bytes; | |
726a989a RB |
870 | tree op0, op1; |
871 | ||
70f34814 RG |
872 | if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR) |
873 | { | |
874 | op0 = gimple_assign_rhs1 (stmt); | |
875 | op1 = gimple_assign_rhs2 (stmt); | |
876 | } | |
877 | else if (gimple_assign_rhs_code (stmt) == ADDR_EXPR) | |
878 | { | |
879 | tree rhs = TREE_OPERAND (gimple_assign_rhs1 (stmt), 0); | |
880 | gcc_assert (TREE_CODE (rhs) == MEM_REF); | |
881 | op0 = TREE_OPERAND (rhs, 0); | |
882 | op1 = TREE_OPERAND (rhs, 1); | |
883 | } | |
884 | else | |
885 | gcc_unreachable (); | |
10a0d495 JJ |
886 | |
887 | if (object_sizes[object_size_type][varno] == unknown[object_size_type]) | |
888 | return false; | |
889 | ||
10a0d495 | 890 | /* Handle PTR + OFFSET here. */ |
5be014d5 | 891 | if (TREE_CODE (op1) == INTEGER_CST |
10a0d495 JJ |
892 | && (TREE_CODE (op0) == SSA_NAME |
893 | || TREE_CODE (op0) == ADDR_EXPR)) | |
894 | { | |
cc269bb6 | 895 | if (! tree_fits_uhwi_p (op1)) |
10a0d495 JJ |
896 | bytes = unknown[object_size_type]; |
897 | else if (TREE_CODE (op0) == SSA_NAME) | |
ae7e9ddd | 898 | return merge_object_sizes (osi, var, op0, tree_to_uhwi (op1)); |
10a0d495 JJ |
899 | else |
900 | { | |
ae7e9ddd | 901 | unsigned HOST_WIDE_INT off = tree_to_uhwi (op1); |
10a0d495 | 902 | |
726a989a | 903 | /* op0 will be ADDR_EXPR here. */ |
05a64756 | 904 | addr_object_size (osi, op0, object_size_type, &bytes); |
ac5a28a6 JH |
905 | if (bytes == unknown[object_size_type]) |
906 | ; | |
907 | else if (off > offset_limit) | |
10a0d495 JJ |
908 | bytes = unknown[object_size_type]; |
909 | else if (off > bytes) | |
910 | bytes = 0; | |
911 | else | |
912 | bytes -= off; | |
913 | } | |
914 | } | |
915 | else | |
916 | bytes = unknown[object_size_type]; | |
917 | ||
918 | if ((object_size_type & 2) == 0) | |
919 | { | |
920 | if (object_sizes[object_size_type][varno] < bytes) | |
921 | object_sizes[object_size_type][varno] = bytes; | |
922 | } | |
923 | else | |
924 | { | |
925 | if (object_sizes[object_size_type][varno] > bytes) | |
926 | object_sizes[object_size_type][varno] = bytes; | |
927 | } | |
928 | return false; | |
929 | } | |
930 | ||
931 | ||
4e71066d | 932 | /* Compute object_sizes for VAR, defined at STMT, which is |
f255541f RC |
933 | a COND_EXPR. Return true if the object size might need reexamination |
934 | later. */ | |
935 | ||
936 | static bool | |
355fe088 | 937 | cond_expr_object_size (struct object_size_info *osi, tree var, gimple *stmt) |
f255541f RC |
938 | { |
939 | tree then_, else_; | |
940 | int object_size_type = osi->object_size_type; | |
941 | unsigned int varno = SSA_NAME_VERSION (var); | |
942 | bool reexamine = false; | |
943 | ||
4e71066d | 944 | gcc_assert (gimple_assign_rhs_code (stmt) == COND_EXPR); |
f255541f RC |
945 | |
946 | if (object_sizes[object_size_type][varno] == unknown[object_size_type]) | |
947 | return false; | |
948 | ||
4e71066d RG |
949 | then_ = gimple_assign_rhs2 (stmt); |
950 | else_ = gimple_assign_rhs3 (stmt); | |
f255541f RC |
951 | |
952 | if (TREE_CODE (then_) == SSA_NAME) | |
953 | reexamine |= merge_object_sizes (osi, var, then_, 0); | |
954 | else | |
955 | expr_object_size (osi, var, then_); | |
956 | ||
0bbb0ca1 JJ |
957 | if (object_sizes[object_size_type][varno] == unknown[object_size_type]) |
958 | return reexamine; | |
959 | ||
f255541f RC |
960 | if (TREE_CODE (else_) == SSA_NAME) |
961 | reexamine |= merge_object_sizes (osi, var, else_, 0); | |
962 | else | |
963 | expr_object_size (osi, var, else_); | |
964 | ||
965 | return reexamine; | |
966 | } | |
967 | ||
10a0d495 JJ |
968 | /* Compute object sizes for VAR. |
969 | For ADDR_EXPR an object size is the number of remaining bytes | |
619519c8 | 970 | to the end of the object (where what is considered an object depends on |
10a0d495 | 971 | OSI->object_size_type). |
726a989a | 972 | For allocation GIMPLE_CALL like malloc or calloc object size is the size |
10a0d495 | 973 | of the allocation. |
5be014d5 | 974 | For POINTER_PLUS_EXPR where second operand is a constant integer, |
10a0d495 JJ |
975 | object size is object size of the first operand minus the constant. |
976 | If the constant is bigger than the number of remaining bytes until the | |
977 | end of the object, object size is 0, but if it is instead a pointer | |
978 | subtraction, object size is unknown[object_size_type]. | |
979 | To differentiate addition from subtraction, ADDR_EXPR returns | |
980 | unknown[object_size_type] for all objects bigger than half of the address | |
981 | space, and constants less than half of the address space are considered | |
982 | addition, while bigger constants subtraction. | |
726a989a | 983 | For a memcpy like GIMPLE_CALL that always returns one of its arguments, the |
10a0d495 JJ |
984 | object size is object size of that argument. |
985 | Otherwise, object size is the maximum of object sizes of variables | |
986 | that it might be set to. */ | |
987 | ||
988 | static void | |
989 | collect_object_sizes_for (struct object_size_info *osi, tree var) | |
990 | { | |
991 | int object_size_type = osi->object_size_type; | |
992 | unsigned int varno = SSA_NAME_VERSION (var); | |
355fe088 | 993 | gimple *stmt; |
10a0d495 JJ |
994 | bool reexamine; |
995 | ||
996 | if (bitmap_bit_p (computed[object_size_type], varno)) | |
997 | return; | |
998 | ||
999 | if (osi->pass == 0) | |
1000 | { | |
fcaa4ca4 | 1001 | if (bitmap_set_bit (osi->visited, varno)) |
10a0d495 | 1002 | { |
10a0d495 JJ |
1003 | object_sizes[object_size_type][varno] |
1004 | = (object_size_type & 2) ? -1 : 0; | |
1005 | } | |
1006 | else | |
1007 | { | |
1008 | /* Found a dependency loop. Mark the variable for later | |
1009 | re-examination. */ | |
1010 | bitmap_set_bit (osi->reexamine, varno); | |
1011 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1012 | { | |
1013 | fprintf (dump_file, "Found a dependency loop at "); | |
1014 | print_generic_expr (dump_file, var, dump_flags); | |
1015 | fprintf (dump_file, "\n"); | |
1016 | } | |
1017 | return; | |
1018 | } | |
1019 | } | |
1020 | ||
1021 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1022 | { | |
1023 | fprintf (dump_file, "Visiting use-def links for "); | |
1024 | print_generic_expr (dump_file, var, dump_flags); | |
1025 | fprintf (dump_file, "\n"); | |
1026 | } | |
1027 | ||
1028 | stmt = SSA_NAME_DEF_STMT (var); | |
1029 | reexamine = false; | |
1030 | ||
726a989a | 1031 | switch (gimple_code (stmt)) |
10a0d495 | 1032 | { |
726a989a | 1033 | case GIMPLE_ASSIGN: |
10a0d495 | 1034 | { |
70f34814 RG |
1035 | tree rhs = gimple_assign_rhs1 (stmt); |
1036 | if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR | |
1037 | || (gimple_assign_rhs_code (stmt) == ADDR_EXPR | |
1038 | && TREE_CODE (TREE_OPERAND (rhs, 0)) == MEM_REF)) | |
726a989a | 1039 | reexamine = plus_stmt_object_size (osi, var, stmt); |
4e71066d RG |
1040 | else if (gimple_assign_rhs_code (stmt) == COND_EXPR) |
1041 | reexamine = cond_expr_object_size (osi, var, stmt); | |
726a989a RB |
1042 | else if (gimple_assign_single_p (stmt) |
1043 | || gimple_assign_unary_nop_p (stmt)) | |
1044 | { | |
726a989a RB |
1045 | if (TREE_CODE (rhs) == SSA_NAME |
1046 | && POINTER_TYPE_P (TREE_TYPE (rhs))) | |
1047 | reexamine = merge_object_sizes (osi, var, rhs, 0); | |
726a989a RB |
1048 | else |
1049 | expr_object_size (osi, var, rhs); | |
1050 | } | |
1051 | else | |
1052 | unknown_object_size (osi, var); | |
1053 | break; | |
1054 | } | |
f255541f | 1055 | |
726a989a RB |
1056 | case GIMPLE_CALL: |
1057 | { | |
538dd0b7 DM |
1058 | gcall *call_stmt = as_a <gcall *> (stmt); |
1059 | tree arg = pass_through_call (call_stmt); | |
726a989a RB |
1060 | if (arg) |
1061 | { | |
1062 | if (TREE_CODE (arg) == SSA_NAME | |
1063 | && POINTER_TYPE_P (TREE_TYPE (arg))) | |
1064 | reexamine = merge_object_sizes (osi, var, arg, 0); | |
726a989a RB |
1065 | else |
1066 | expr_object_size (osi, var, arg); | |
1067 | } | |
1068 | else | |
538dd0b7 | 1069 | call_object_size (osi, var, call_stmt); |
10a0d495 JJ |
1070 | break; |
1071 | } | |
1072 | ||
726a989a | 1073 | case GIMPLE_ASM: |
10a0d495 JJ |
1074 | /* Pointers defined by __asm__ statements can point anywhere. */ |
1075 | object_sizes[object_size_type][varno] = unknown[object_size_type]; | |
1076 | break; | |
1077 | ||
726a989a | 1078 | case GIMPLE_NOP: |
70b5e7dc RG |
1079 | if (SSA_NAME_VAR (var) |
1080 | && TREE_CODE (SSA_NAME_VAR (var)) == PARM_DECL) | |
1081 | expr_object_size (osi, var, SSA_NAME_VAR (var)); | |
1082 | else | |
1083 | /* Uninitialized SSA names point nowhere. */ | |
1084 | object_sizes[object_size_type][varno] = unknown[object_size_type]; | |
10a0d495 JJ |
1085 | break; |
1086 | ||
726a989a | 1087 | case GIMPLE_PHI: |
10a0d495 | 1088 | { |
726a989a | 1089 | unsigned i; |
10a0d495 | 1090 | |
726a989a | 1091 | for (i = 0; i < gimple_phi_num_args (stmt); i++) |
10a0d495 | 1092 | { |
726a989a | 1093 | tree rhs = gimple_phi_arg (stmt, i)->def; |
10a0d495 JJ |
1094 | |
1095 | if (object_sizes[object_size_type][varno] | |
1096 | == unknown[object_size_type]) | |
1097 | break; | |
1098 | ||
1099 | if (TREE_CODE (rhs) == SSA_NAME) | |
1100 | reexamine |= merge_object_sizes (osi, var, rhs, 0); | |
1101 | else if (osi->pass == 0) | |
1102 | expr_object_size (osi, var, rhs); | |
1103 | } | |
1104 | break; | |
1105 | } | |
726a989a | 1106 | |
10a0d495 JJ |
1107 | default: |
1108 | gcc_unreachable (); | |
1109 | } | |
1110 | ||
1111 | if (! reexamine | |
1112 | || object_sizes[object_size_type][varno] == unknown[object_size_type]) | |
1113 | { | |
1114 | bitmap_set_bit (computed[object_size_type], varno); | |
1115 | bitmap_clear_bit (osi->reexamine, varno); | |
1116 | } | |
1117 | else | |
1118 | { | |
1119 | bitmap_set_bit (osi->reexamine, varno); | |
1120 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1121 | { | |
1122 | fprintf (dump_file, "Need to reexamine "); | |
1123 | print_generic_expr (dump_file, var, dump_flags); | |
1124 | fprintf (dump_file, "\n"); | |
1125 | } | |
1126 | } | |
1127 | } | |
1128 | ||
1129 | ||
1130 | /* Helper function for check_for_plus_in_loops. Called recursively | |
1131 | to detect loops. */ | |
1132 | ||
1133 | static void | |
1134 | check_for_plus_in_loops_1 (struct object_size_info *osi, tree var, | |
1135 | unsigned int depth) | |
1136 | { | |
355fe088 | 1137 | gimple *stmt = SSA_NAME_DEF_STMT (var); |
10a0d495 JJ |
1138 | unsigned int varno = SSA_NAME_VERSION (var); |
1139 | ||
1140 | if (osi->depths[varno]) | |
1141 | { | |
1142 | if (osi->depths[varno] != depth) | |
1143 | { | |
1144 | unsigned int *sp; | |
1145 | ||
1146 | /* Found a loop involving pointer addition. */ | |
1147 | for (sp = osi->tos; sp > osi->stack; ) | |
1148 | { | |
1149 | --sp; | |
1150 | bitmap_clear_bit (osi->reexamine, *sp); | |
1151 | bitmap_set_bit (computed[osi->object_size_type], *sp); | |
1152 | object_sizes[osi->object_size_type][*sp] = 0; | |
1153 | if (*sp == varno) | |
1154 | break; | |
1155 | } | |
1156 | } | |
1157 | return; | |
1158 | } | |
1159 | else if (! bitmap_bit_p (osi->reexamine, varno)) | |
1160 | return; | |
1161 | ||
1162 | osi->depths[varno] = depth; | |
1163 | *osi->tos++ = varno; | |
1164 | ||
726a989a | 1165 | switch (gimple_code (stmt)) |
10a0d495 | 1166 | { |
10a0d495 | 1167 | |
726a989a | 1168 | case GIMPLE_ASSIGN: |
10a0d495 | 1169 | { |
726a989a RB |
1170 | if ((gimple_assign_single_p (stmt) |
1171 | || gimple_assign_unary_nop_p (stmt)) | |
1172 | && TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME) | |
1173 | { | |
1174 | tree rhs = gimple_assign_rhs1 (stmt); | |
1175 | ||
1176 | check_for_plus_in_loops_1 (osi, rhs, depth); | |
1177 | } | |
1178 | else if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR) | |
1179 | { | |
1180 | tree basevar = gimple_assign_rhs1 (stmt); | |
1181 | tree cst = gimple_assign_rhs2 (stmt); | |
1182 | ||
1183 | gcc_assert (TREE_CODE (cst) == INTEGER_CST); | |
1184 | ||
1185 | check_for_plus_in_loops_1 (osi, basevar, | |
1186 | depth + !integer_zerop (cst)); | |
1187 | } | |
1188 | else | |
1189 | gcc_unreachable (); | |
1190 | break; | |
1191 | } | |
10a0d495 | 1192 | |
726a989a RB |
1193 | case GIMPLE_CALL: |
1194 | { | |
538dd0b7 DM |
1195 | gcall *call_stmt = as_a <gcall *> (stmt); |
1196 | tree arg = pass_through_call (call_stmt); | |
726a989a RB |
1197 | if (arg) |
1198 | { | |
1199 | if (TREE_CODE (arg) == SSA_NAME) | |
1200 | check_for_plus_in_loops_1 (osi, arg, depth); | |
1201 | else | |
1202 | gcc_unreachable (); | |
1203 | } | |
1204 | break; | |
10a0d495 | 1205 | } |
726a989a RB |
1206 | |
1207 | case GIMPLE_PHI: | |
10a0d495 | 1208 | { |
726a989a | 1209 | unsigned i; |
10a0d495 | 1210 | |
726a989a | 1211 | for (i = 0; i < gimple_phi_num_args (stmt); i++) |
10a0d495 | 1212 | { |
726a989a | 1213 | tree rhs = gimple_phi_arg (stmt, i)->def; |
10a0d495 JJ |
1214 | |
1215 | if (TREE_CODE (rhs) == SSA_NAME) | |
1216 | check_for_plus_in_loops_1 (osi, rhs, depth); | |
1217 | } | |
1218 | break; | |
1219 | } | |
726a989a | 1220 | |
10a0d495 JJ |
1221 | default: |
1222 | gcc_unreachable (); | |
1223 | } | |
1224 | ||
1225 | osi->depths[varno] = 0; | |
1226 | osi->tos--; | |
1227 | } | |
1228 | ||
1229 | ||
1230 | /* Check if some pointer we are computing object size of is being increased | |
1231 | within a loop. If yes, assume all the SSA variables participating in | |
1232 | that loop have minimum object sizes 0. */ | |
1233 | ||
1234 | static void | |
1235 | check_for_plus_in_loops (struct object_size_info *osi, tree var) | |
1236 | { | |
355fe088 | 1237 | gimple *stmt = SSA_NAME_DEF_STMT (var); |
10a0d495 | 1238 | |
726a989a RB |
1239 | /* NOTE: In the pre-tuples code, we handled a CALL_EXPR here, |
1240 | and looked for a POINTER_PLUS_EXPR in the pass-through | |
1241 | argument, if any. In GIMPLE, however, such an expression | |
1242 | is not a valid call operand. */ | |
10a0d495 | 1243 | |
726a989a RB |
1244 | if (is_gimple_assign (stmt) |
1245 | && gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR) | |
1246 | { | |
1247 | tree basevar = gimple_assign_rhs1 (stmt); | |
1248 | tree cst = gimple_assign_rhs2 (stmt); | |
b8698a0f | 1249 | |
726a989a RB |
1250 | gcc_assert (TREE_CODE (cst) == INTEGER_CST); |
1251 | ||
1252 | if (integer_zerop (cst)) | |
1253 | return; | |
1254 | ||
1255 | osi->depths[SSA_NAME_VERSION (basevar)] = 1; | |
1256 | *osi->tos++ = SSA_NAME_VERSION (basevar); | |
1257 | check_for_plus_in_loops_1 (osi, var, 2); | |
1258 | osi->depths[SSA_NAME_VERSION (basevar)] = 0; | |
1259 | osi->tos--; | |
10a0d495 JJ |
1260 | } |
1261 | } | |
1262 | ||
1263 | ||
1264 | /* Initialize data structures for the object size computation. */ | |
1265 | ||
1266 | void | |
1267 | init_object_sizes (void) | |
1268 | { | |
1269 | int object_size_type; | |
1270 | ||
db84d11e | 1271 | if (computed[0]) |
10a0d495 JJ |
1272 | return; |
1273 | ||
1274 | for (object_size_type = 0; object_size_type <= 3; object_size_type++) | |
1275 | { | |
db84d11e | 1276 | object_sizes[object_size_type].safe_grow (num_ssa_names); |
10a0d495 JJ |
1277 | computed[object_size_type] = BITMAP_ALLOC (NULL); |
1278 | } | |
1279 | ||
1280 | init_offset_limit (); | |
1281 | } | |
1282 | ||
1283 | ||
1284 | /* Destroy data structures after the object size computation. */ | |
1285 | ||
eb07c7cf | 1286 | void |
10a0d495 JJ |
1287 | fini_object_sizes (void) |
1288 | { | |
1289 | int object_size_type; | |
1290 | ||
1291 | for (object_size_type = 0; object_size_type <= 3; object_size_type++) | |
1292 | { | |
db84d11e | 1293 | object_sizes[object_size_type].release (); |
10a0d495 | 1294 | BITMAP_FREE (computed[object_size_type]); |
10a0d495 JJ |
1295 | } |
1296 | } | |
1297 | ||
1298 | ||
1299 | /* Simple pass to optimize all __builtin_object_size () builtins. */ | |
1300 | ||
be55bfe6 TS |
1301 | namespace { |
1302 | ||
1303 | const pass_data pass_data_object_sizes = | |
1304 | { | |
1305 | GIMPLE_PASS, /* type */ | |
1306 | "objsz", /* name */ | |
1307 | OPTGROUP_NONE, /* optinfo_flags */ | |
be55bfe6 TS |
1308 | TV_NONE, /* tv_id */ |
1309 | ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
1310 | 0, /* properties_provided */ | |
1311 | 0, /* properties_destroyed */ | |
1312 | 0, /* todo_flags_start */ | |
3bea341f | 1313 | 0, /* todo_flags_finish */ |
be55bfe6 TS |
1314 | }; |
1315 | ||
1316 | class pass_object_sizes : public gimple_opt_pass | |
1317 | { | |
1318 | public: | |
1319 | pass_object_sizes (gcc::context *ctxt) | |
813ccd83 | 1320 | : gimple_opt_pass (pass_data_object_sizes, ctxt), insert_min_max_p (false) |
be55bfe6 TS |
1321 | {} |
1322 | ||
1323 | /* opt_pass methods: */ | |
1324 | opt_pass * clone () { return new pass_object_sizes (m_ctxt); } | |
813ccd83 TV |
1325 | void set_pass_param (unsigned int n, bool param) |
1326 | { | |
1327 | gcc_assert (n == 0); | |
1328 | insert_min_max_p = param; | |
1329 | } | |
be55bfe6 TS |
1330 | virtual unsigned int execute (function *); |
1331 | ||
813ccd83 TV |
1332 | private: |
1333 | /* Determines whether the pass instance creates MIN/MAX_EXPRs. */ | |
1334 | bool insert_min_max_p; | |
be55bfe6 TS |
1335 | }; // class pass_object_sizes |
1336 | ||
1e080ab4 RB |
1337 | /* Dummy valueize function. */ |
1338 | ||
1339 | static tree | |
1340 | do_valueize (tree t) | |
1341 | { | |
1342 | return t; | |
1343 | } | |
1344 | ||
be55bfe6 TS |
1345 | unsigned int |
1346 | pass_object_sizes::execute (function *fun) | |
10a0d495 JJ |
1347 | { |
1348 | basic_block bb; | |
be55bfe6 | 1349 | FOR_EACH_BB_FN (bb, fun) |
10a0d495 | 1350 | { |
726a989a RB |
1351 | gimple_stmt_iterator i; |
1352 | for (i = gsi_start_bb (bb); !gsi_end_p (i); gsi_next (&i)) | |
10a0d495 | 1353 | { |
1eadb567 | 1354 | tree result; |
355fe088 | 1355 | gimple *call = gsi_stmt (i); |
1eadb567 | 1356 | if (!gimple_call_builtin_p (call, BUILT_IN_OBJECT_SIZE)) |
10a0d495 JJ |
1357 | continue; |
1358 | ||
1359 | init_object_sizes (); | |
672ff0b6 | 1360 | |
813ccd83 | 1361 | /* If insert_min_max_p, only attempt to fold |
672ff0b6 JJ |
1362 | __builtin_object_size (x, 1) and __builtin_object_size (x, 3), |
1363 | and rather than folding the builtin to the constant if any, | |
1364 | create a MIN_EXPR or MAX_EXPR of the __builtin_object_size | |
1365 | call result and the computed constant. */ | |
813ccd83 | 1366 | if (insert_min_max_p) |
672ff0b6 JJ |
1367 | { |
1368 | tree ost = gimple_call_arg (call, 1); | |
1369 | if (tree_fits_uhwi_p (ost)) | |
1370 | { | |
1371 | unsigned HOST_WIDE_INT object_size_type = tree_to_uhwi (ost); | |
1372 | tree ptr = gimple_call_arg (call, 0); | |
1373 | tree lhs = gimple_call_lhs (call); | |
1374 | if ((object_size_type == 1 || object_size_type == 3) | |
1375 | && (TREE_CODE (ptr) == ADDR_EXPR | |
1376 | || TREE_CODE (ptr) == SSA_NAME) | |
1377 | && lhs) | |
1378 | { | |
1379 | tree type = TREE_TYPE (lhs); | |
05a64756 MS |
1380 | unsigned HOST_WIDE_INT bytes; |
1381 | if (compute_builtin_object_size (ptr, object_size_type, | |
1382 | &bytes) | |
672ff0b6 JJ |
1383 | && wi::fits_to_tree_p (bytes, type)) |
1384 | { | |
1385 | tree tem = make_ssa_name (type); | |
1386 | gimple_call_set_lhs (call, tem); | |
1387 | enum tree_code code | |
1388 | = object_size_type == 1 ? MIN_EXPR : MAX_EXPR; | |
1389 | tree cst = build_int_cstu (type, bytes); | |
355fe088 TS |
1390 | gimple *g |
1391 | = gimple_build_assign (lhs, code, tem, cst); | |
672ff0b6 JJ |
1392 | gsi_insert_after (&i, g, GSI_NEW_STMT); |
1393 | update_stmt (call); | |
1394 | } | |
1395 | } | |
1396 | } | |
1397 | continue; | |
1398 | } | |
1399 | ||
1e080ab4 RB |
1400 | tree lhs = gimple_call_lhs (call); |
1401 | if (!lhs) | |
1402 | continue; | |
1403 | ||
1404 | result = gimple_fold_stmt_to_constant (call, do_valueize); | |
10a0d495 JJ |
1405 | if (!result) |
1406 | { | |
672ff0b6 JJ |
1407 | tree ost = gimple_call_arg (call, 1); |
1408 | ||
1409 | if (tree_fits_uhwi_p (ost)) | |
10a0d495 | 1410 | { |
672ff0b6 | 1411 | unsigned HOST_WIDE_INT object_size_type = tree_to_uhwi (ost); |
10a0d495 | 1412 | |
672ff0b6 JJ |
1413 | if (object_size_type < 2) |
1414 | result = fold_convert (size_type_node, | |
1415 | integer_minus_one_node); | |
1416 | else if (object_size_type < 4) | |
1417 | result = build_zero_cst (size_type_node); | |
10a0d495 JJ |
1418 | } |
1419 | ||
1420 | if (!result) | |
1421 | continue; | |
1422 | } | |
1423 | ||
1eadb567 RB |
1424 | gcc_assert (TREE_CODE (result) == INTEGER_CST); |
1425 | ||
10a0d495 JJ |
1426 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1427 | { | |
1428 | fprintf (dump_file, "Simplified\n "); | |
726a989a | 1429 | print_gimple_stmt (dump_file, call, 0, dump_flags); |
1eadb567 | 1430 | fprintf (dump_file, " to "); |
ef6cb4c7 | 1431 | print_generic_expr (dump_file, result); |
1eadb567 | 1432 | fprintf (dump_file, "\n"); |
10a0d495 JJ |
1433 | } |
1434 | ||
1eadb567 | 1435 | /* Propagate into all uses and fold those stmts. */ |
9ecb3ecc JJ |
1436 | if (!SSA_NAME_OCCURS_IN_ABNORMAL_PHI (lhs)) |
1437 | replace_uses_by (lhs, result); | |
1438 | else | |
1439 | replace_call_with_value (&i, result); | |
10a0d495 JJ |
1440 | } |
1441 | } | |
1442 | ||
1443 | fini_object_sizes (); | |
c2924966 | 1444 | return 0; |
10a0d495 JJ |
1445 | } |
1446 | ||
27a4cd48 DM |
1447 | } // anon namespace |
1448 | ||
1449 | gimple_opt_pass * | |
1450 | make_pass_object_sizes (gcc::context *ctxt) | |
1451 | { | |
1452 | return new pass_object_sizes (ctxt); | |
1453 | } |