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10a0d495 | 1 | /* __builtin_object_size (ptr, object_size_type) computation |
23a5b65a | 2 | Copyright (C) 2004-2014 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" | |
24 | #include "tm.h" | |
25 | #include "tree.h" | |
d8a2d370 | 26 | #include "tree-object-size.h" |
718f9c0f | 27 | #include "diagnostic-core.h" |
cf835838 | 28 | #include "gimple-pretty-print.h" |
442b4905 | 29 | #include "bitmap.h" |
2fb9a547 AM |
30 | #include "basic-block.h" |
31 | #include "tree-ssa-alias.h" | |
32 | #include "internal-fn.h" | |
33 | #include "gimple-fold.h" | |
34 | #include "gimple-expr.h" | |
35 | #include "is-a.h" | |
442b4905 | 36 | #include "gimple.h" |
5be5c238 | 37 | #include "gimple-iterator.h" |
442b4905 | 38 | #include "gimple-ssa.h" |
d8a2d370 | 39 | #include "stringpool.h" |
442b4905 | 40 | #include "tree-ssanames.h" |
10a0d495 JJ |
41 | #include "tree-pass.h" |
42 | #include "tree-ssa-propagate.h" | |
1eadb567 RB |
43 | #include "tree-phinodes.h" |
44 | #include "ssa-iterators.h" | |
9b2b7279 | 45 | #include "builtins.h" |
10a0d495 JJ |
46 | |
47 | struct object_size_info | |
48 | { | |
49 | int object_size_type; | |
50 | bitmap visited, reexamine; | |
51 | int pass; | |
52 | bool changed; | |
53 | unsigned int *depths; | |
54 | unsigned int *stack, *tos; | |
55 | }; | |
56 | ||
4cdce1a8 | 57 | static const unsigned HOST_WIDE_INT unknown[4] = { -1, -1, 0, 0 }; |
10a0d495 | 58 | |
ac545c64 | 59 | static tree compute_object_offset (const_tree, const_tree); |
eb9ed98a JJ |
60 | static unsigned HOST_WIDE_INT addr_object_size (struct object_size_info *, |
61 | const_tree, int); | |
726a989a RB |
62 | static unsigned HOST_WIDE_INT alloc_object_size (const_gimple, int); |
63 | static tree pass_through_call (const_gimple); | |
10a0d495 JJ |
64 | static void collect_object_sizes_for (struct object_size_info *, tree); |
65 | static void expr_object_size (struct object_size_info *, tree, tree); | |
66 | static bool merge_object_sizes (struct object_size_info *, tree, tree, | |
67 | unsigned HOST_WIDE_INT); | |
726a989a | 68 | static bool plus_stmt_object_size (struct object_size_info *, tree, gimple); |
4e71066d | 69 | static bool cond_expr_object_size (struct object_size_info *, tree, gimple); |
10a0d495 JJ |
70 | static void init_offset_limit (void); |
71 | static void check_for_plus_in_loops (struct object_size_info *, tree); | |
72 | static void check_for_plus_in_loops_1 (struct object_size_info *, tree, | |
73 | unsigned int); | |
74 | ||
75 | /* object_sizes[0] is upper bound for number of bytes till the end of | |
76 | the object. | |
77 | object_sizes[1] is upper bound for number of bytes till the end of | |
78 | the subobject (innermost array or field with address taken). | |
79 | object_sizes[2] is lower bound for number of bytes till the end of | |
80 | the object and object_sizes[3] lower bound for subobject. */ | |
db84d11e | 81 | static vec<unsigned HOST_WIDE_INT> object_sizes[4]; |
10a0d495 JJ |
82 | |
83 | /* Bitmaps what object sizes have been computed already. */ | |
84 | static bitmap computed[4]; | |
85 | ||
86 | /* Maximum value of offset we consider to be addition. */ | |
87 | static unsigned HOST_WIDE_INT offset_limit; | |
88 | ||
89 | ||
90 | /* Initialize OFFSET_LIMIT variable. */ | |
91 | static void | |
92 | init_offset_limit (void) | |
93 | { | |
cc269bb6 | 94 | if (tree_fits_uhwi_p (TYPE_MAX_VALUE (sizetype))) |
ae7e9ddd | 95 | offset_limit = tree_to_uhwi (TYPE_MAX_VALUE (sizetype)); |
10a0d495 JJ |
96 | else |
97 | offset_limit = -1; | |
98 | offset_limit /= 2; | |
99 | } | |
100 | ||
101 | ||
102 | /* Compute offset of EXPR within VAR. Return error_mark_node | |
103 | if unknown. */ | |
104 | ||
105 | static tree | |
ac545c64 | 106 | compute_object_offset (const_tree expr, const_tree var) |
10a0d495 JJ |
107 | { |
108 | enum tree_code code = PLUS_EXPR; | |
109 | tree base, off, t; | |
110 | ||
111 | if (expr == var) | |
112 | return size_zero_node; | |
113 | ||
114 | switch (TREE_CODE (expr)) | |
115 | { | |
116 | case COMPONENT_REF: | |
117 | base = compute_object_offset (TREE_OPERAND (expr, 0), var); | |
118 | if (base == error_mark_node) | |
119 | return base; | |
120 | ||
121 | t = TREE_OPERAND (expr, 1); | |
122 | off = size_binop (PLUS_EXPR, DECL_FIELD_OFFSET (t), | |
ae7e9ddd | 123 | size_int (tree_to_uhwi (DECL_FIELD_BIT_OFFSET (t)) |
10a0d495 JJ |
124 | / BITS_PER_UNIT)); |
125 | break; | |
126 | ||
127 | case REALPART_EXPR: | |
1043771b | 128 | CASE_CONVERT: |
10a0d495 JJ |
129 | case VIEW_CONVERT_EXPR: |
130 | case NON_LVALUE_EXPR: | |
131 | return compute_object_offset (TREE_OPERAND (expr, 0), var); | |
132 | ||
133 | case IMAGPART_EXPR: | |
134 | base = compute_object_offset (TREE_OPERAND (expr, 0), var); | |
135 | if (base == error_mark_node) | |
136 | return base; | |
137 | ||
138 | off = TYPE_SIZE_UNIT (TREE_TYPE (expr)); | |
139 | break; | |
140 | ||
141 | case ARRAY_REF: | |
142 | base = compute_object_offset (TREE_OPERAND (expr, 0), var); | |
143 | if (base == error_mark_node) | |
144 | return base; | |
145 | ||
146 | t = TREE_OPERAND (expr, 1); | |
147 | if (TREE_CODE (t) == INTEGER_CST && tree_int_cst_sgn (t) < 0) | |
148 | { | |
149 | code = MINUS_EXPR; | |
150 | t = fold_build1 (NEGATE_EXPR, TREE_TYPE (t), t); | |
151 | } | |
b6f65e3c | 152 | t = fold_convert (sizetype, t); |
10a0d495 JJ |
153 | off = size_binop (MULT_EXPR, TYPE_SIZE_UNIT (TREE_TYPE (expr)), t); |
154 | break; | |
155 | ||
70f34814 RG |
156 | case MEM_REF: |
157 | gcc_assert (TREE_CODE (TREE_OPERAND (expr, 0)) == ADDR_EXPR); | |
807e902e | 158 | return wide_int_to_tree (sizetype, mem_ref_offset (expr)); |
70f34814 | 159 | |
10a0d495 JJ |
160 | default: |
161 | return error_mark_node; | |
162 | } | |
163 | ||
164 | return size_binop (code, base, off); | |
165 | } | |
166 | ||
167 | ||
168 | /* Compute __builtin_object_size for PTR, which is a ADDR_EXPR. | |
169 | OBJECT_SIZE_TYPE is the second argument from __builtin_object_size. | |
170 | If unknown, return unknown[object_size_type]. */ | |
171 | ||
172 | static unsigned HOST_WIDE_INT | |
eb9ed98a JJ |
173 | addr_object_size (struct object_size_info *osi, const_tree ptr, |
174 | int object_size_type) | |
10a0d495 | 175 | { |
eb9ed98a | 176 | tree pt_var, pt_var_size = NULL_TREE, var_size, bytes; |
10a0d495 JJ |
177 | |
178 | gcc_assert (TREE_CODE (ptr) == ADDR_EXPR); | |
179 | ||
180 | pt_var = TREE_OPERAND (ptr, 0); | |
d837d73d RG |
181 | while (handled_component_p (pt_var)) |
182 | pt_var = TREE_OPERAND (pt_var, 0); | |
10a0d495 JJ |
183 | |
184 | if (pt_var | |
d837d73d | 185 | && TREE_CODE (pt_var) == MEM_REF) |
10a0d495 | 186 | { |
eb9ed98a | 187 | unsigned HOST_WIDE_INT sz; |
10a0d495 | 188 | |
d837d73d | 189 | if (!osi || (object_size_type & 1) != 0 |
ea17de23 | 190 | || TREE_CODE (TREE_OPERAND (pt_var, 0)) != SSA_NAME) |
70f34814 RG |
191 | { |
192 | sz = compute_builtin_object_size (TREE_OPERAND (pt_var, 0), | |
193 | object_size_type & ~1); | |
70f34814 | 194 | } |
eb9ed98a | 195 | else |
10a0d495 | 196 | { |
eb9ed98a JJ |
197 | tree var = TREE_OPERAND (pt_var, 0); |
198 | if (osi->pass == 0) | |
199 | collect_object_sizes_for (osi, var); | |
200 | if (bitmap_bit_p (computed[object_size_type], | |
201 | SSA_NAME_VERSION (var))) | |
202 | sz = object_sizes[object_size_type][SSA_NAME_VERSION (var)]; | |
203 | else | |
204 | sz = unknown[object_size_type]; | |
d837d73d RG |
205 | } |
206 | if (sz != unknown[object_size_type]) | |
207 | { | |
807e902e KZ |
208 | offset_int dsz = wi::sub (sz, mem_ref_offset (pt_var)); |
209 | if (wi::neg_p (dsz)) | |
d837d73d | 210 | sz = 0; |
807e902e | 211 | else if (wi::fits_uhwi_p (dsz)) |
27bcd47c | 212 | sz = dsz.to_uhwi (); |
70f34814 | 213 | else |
d837d73d | 214 | sz = unknown[object_size_type]; |
eb9ed98a JJ |
215 | } |
216 | ||
217 | if (sz != unknown[object_size_type] && sz < offset_limit) | |
218 | pt_var_size = size_int (sz); | |
219 | } | |
e497b9bd RG |
220 | else if (pt_var |
221 | && DECL_P (pt_var) | |
cc269bb6 | 222 | && tree_fits_uhwi_p (DECL_SIZE_UNIT (pt_var)) |
7d362f6c | 223 | && tree_to_uhwi (DECL_SIZE_UNIT (pt_var)) < offset_limit) |
e497b9bd | 224 | pt_var_size = DECL_SIZE_UNIT (pt_var); |
eb9ed98a | 225 | else if (pt_var |
d837d73d | 226 | && TREE_CODE (pt_var) == STRING_CST |
eb9ed98a | 227 | && TYPE_SIZE_UNIT (TREE_TYPE (pt_var)) |
cc269bb6 | 228 | && tree_fits_uhwi_p (TYPE_SIZE_UNIT (TREE_TYPE (pt_var))) |
7d362f6c | 229 | && tree_to_uhwi (TYPE_SIZE_UNIT (TREE_TYPE (pt_var))) |
eb9ed98a JJ |
230 | < offset_limit) |
231 | pt_var_size = TYPE_SIZE_UNIT (TREE_TYPE (pt_var)); | |
232 | else | |
233 | return unknown[object_size_type]; | |
234 | ||
235 | if (pt_var != TREE_OPERAND (ptr, 0)) | |
236 | { | |
237 | tree var; | |
10a0d495 | 238 | |
eb9ed98a JJ |
239 | if (object_size_type & 1) |
240 | { | |
241 | var = TREE_OPERAND (ptr, 0); | |
242 | ||
243 | while (var != pt_var | |
244 | && TREE_CODE (var) != BIT_FIELD_REF | |
245 | && TREE_CODE (var) != COMPONENT_REF | |
246 | && TREE_CODE (var) != ARRAY_REF | |
247 | && TREE_CODE (var) != ARRAY_RANGE_REF | |
248 | && TREE_CODE (var) != REALPART_EXPR | |
249 | && TREE_CODE (var) != IMAGPART_EXPR) | |
250 | var = TREE_OPERAND (var, 0); | |
251 | if (var != pt_var && TREE_CODE (var) == ARRAY_REF) | |
38027156 | 252 | var = TREE_OPERAND (var, 0); |
eb9ed98a | 253 | if (! TYPE_SIZE_UNIT (TREE_TYPE (var)) |
cc269bb6 | 254 | || ! tree_fits_uhwi_p (TYPE_SIZE_UNIT (TREE_TYPE (var))) |
eb9ed98a JJ |
255 | || (pt_var_size |
256 | && tree_int_cst_lt (pt_var_size, | |
257 | TYPE_SIZE_UNIT (TREE_TYPE (var))))) | |
258 | var = pt_var; | |
70f34814 | 259 | else if (var != pt_var && TREE_CODE (pt_var) == MEM_REF) |
10a0d495 | 260 | { |
eb9ed98a JJ |
261 | tree v = var; |
262 | /* For &X->fld, compute object size only if fld isn't the last | |
263 | field, as struct { int i; char c[1]; } is often used instead | |
264 | of flexible array member. */ | |
265 | while (v && v != pt_var) | |
266 | switch (TREE_CODE (v)) | |
267 | { | |
268 | case ARRAY_REF: | |
269 | if (TYPE_SIZE_UNIT (TREE_TYPE (TREE_OPERAND (v, 0))) | |
270 | && TREE_CODE (TREE_OPERAND (v, 1)) == INTEGER_CST) | |
271 | { | |
272 | tree domain | |
273 | = TYPE_DOMAIN (TREE_TYPE (TREE_OPERAND (v, 0))); | |
274 | if (domain | |
275 | && TYPE_MAX_VALUE (domain) | |
276 | && TREE_CODE (TYPE_MAX_VALUE (domain)) | |
277 | == INTEGER_CST | |
278 | && tree_int_cst_lt (TREE_OPERAND (v, 1), | |
279 | TYPE_MAX_VALUE (domain))) | |
280 | { | |
281 | v = NULL_TREE; | |
282 | break; | |
283 | } | |
284 | } | |
285 | v = TREE_OPERAND (v, 0); | |
286 | break; | |
287 | case REALPART_EXPR: | |
288 | case IMAGPART_EXPR: | |
289 | v = NULL_TREE; | |
290 | break; | |
291 | case COMPONENT_REF: | |
8593e0b6 JJ |
292 | if (TREE_CODE (TREE_TYPE (v)) != ARRAY_TYPE) |
293 | { | |
294 | v = NULL_TREE; | |
295 | break; | |
296 | } | |
38027156 JJ |
297 | while (v != pt_var && TREE_CODE (v) == COMPONENT_REF) |
298 | if (TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0))) | |
299 | != UNION_TYPE | |
300 | && TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0))) | |
301 | != QUAL_UNION_TYPE) | |
302 | break; | |
303 | else | |
304 | v = TREE_OPERAND (v, 0); | |
305 | if (TREE_CODE (v) == COMPONENT_REF | |
306 | && TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0))) | |
307 | == RECORD_TYPE) | |
eb9ed98a | 308 | { |
910ad8de NF |
309 | tree fld_chain = DECL_CHAIN (TREE_OPERAND (v, 1)); |
310 | for (; fld_chain; fld_chain = DECL_CHAIN (fld_chain)) | |
8593e0b6 JJ |
311 | if (TREE_CODE (fld_chain) == FIELD_DECL) |
312 | break; | |
313 | ||
314 | if (fld_chain) | |
315 | { | |
316 | v = NULL_TREE; | |
eb9ed98a | 317 | break; |
8593e0b6 | 318 | } |
38027156 | 319 | v = TREE_OPERAND (v, 0); |
eb9ed98a | 320 | } |
38027156 JJ |
321 | while (v != pt_var && TREE_CODE (v) == COMPONENT_REF) |
322 | if (TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0))) | |
323 | != UNION_TYPE | |
324 | && TREE_CODE (TREE_TYPE (TREE_OPERAND (v, 0))) | |
325 | != QUAL_UNION_TYPE) | |
8593e0b6 JJ |
326 | break; |
327 | else | |
328 | v = TREE_OPERAND (v, 0); | |
38027156 | 329 | if (v != pt_var) |
8593e0b6 JJ |
330 | v = NULL_TREE; |
331 | else | |
332 | v = pt_var; | |
eb9ed98a JJ |
333 | break; |
334 | default: | |
335 | v = pt_var; | |
336 | break; | |
337 | } | |
338 | if (v == pt_var) | |
10a0d495 JJ |
339 | var = pt_var; |
340 | } | |
eb9ed98a JJ |
341 | } |
342 | else | |
343 | var = pt_var; | |
10a0d495 | 344 | |
eb9ed98a JJ |
345 | if (var != pt_var) |
346 | var_size = TYPE_SIZE_UNIT (TREE_TYPE (var)); | |
347 | else if (!pt_var_size) | |
348 | return unknown[object_size_type]; | |
349 | else | |
350 | var_size = pt_var_size; | |
351 | bytes = compute_object_offset (TREE_OPERAND (ptr, 0), var); | |
352 | if (bytes != error_mark_node) | |
353 | { | |
354 | if (TREE_CODE (bytes) == INTEGER_CST | |
355 | && tree_int_cst_lt (var_size, bytes)) | |
356 | bytes = size_zero_node; | |
357 | else | |
358 | bytes = size_binop (MINUS_EXPR, var_size, bytes); | |
359 | } | |
360 | if (var != pt_var | |
361 | && pt_var_size | |
70f34814 | 362 | && TREE_CODE (pt_var) == MEM_REF |
eb9ed98a JJ |
363 | && bytes != error_mark_node) |
364 | { | |
365 | tree bytes2 = compute_object_offset (TREE_OPERAND (ptr, 0), pt_var); | |
366 | if (bytes2 != error_mark_node) | |
10a0d495 | 367 | { |
eb9ed98a JJ |
368 | if (TREE_CODE (bytes2) == INTEGER_CST |
369 | && tree_int_cst_lt (pt_var_size, bytes2)) | |
370 | bytes2 = size_zero_node; | |
10a0d495 | 371 | else |
98a129b9 | 372 | bytes2 = size_binop (MINUS_EXPR, pt_var_size, bytes2); |
eb9ed98a | 373 | bytes = size_binop (MIN_EXPR, bytes, bytes2); |
10a0d495 JJ |
374 | } |
375 | } | |
10a0d495 | 376 | } |
eb9ed98a JJ |
377 | else if (!pt_var_size) |
378 | return unknown[object_size_type]; | |
379 | else | |
380 | bytes = pt_var_size; | |
381 | ||
cc269bb6 | 382 | if (tree_fits_uhwi_p (bytes)) |
ae7e9ddd | 383 | return tree_to_uhwi (bytes); |
10a0d495 JJ |
384 | |
385 | return unknown[object_size_type]; | |
386 | } | |
387 | ||
388 | ||
726a989a | 389 | /* Compute __builtin_object_size for CALL, which is a GIMPLE_CALL. |
10a0d495 JJ |
390 | Handles various allocation calls. OBJECT_SIZE_TYPE is the second |
391 | argument from __builtin_object_size. If unknown, return | |
392 | unknown[object_size_type]. */ | |
393 | ||
394 | static unsigned HOST_WIDE_INT | |
726a989a | 395 | alloc_object_size (const_gimple call, int object_size_type) |
10a0d495 | 396 | { |
5039610b | 397 | tree callee, bytes = NULL_TREE; |
51bc54a6 DM |
398 | tree alloc_size; |
399 | int arg1 = -1, arg2 = -1; | |
10a0d495 | 400 | |
726a989a | 401 | gcc_assert (is_gimple_call (call)); |
10a0d495 | 402 | |
726a989a | 403 | callee = gimple_call_fndecl (call); |
51bc54a6 DM |
404 | if (!callee) |
405 | return unknown[object_size_type]; | |
406 | ||
c3284718 RS |
407 | alloc_size = lookup_attribute ("alloc_size", |
408 | TYPE_ATTRIBUTES (TREE_TYPE (callee))); | |
51bc54a6 DM |
409 | if (alloc_size && TREE_VALUE (alloc_size)) |
410 | { | |
411 | tree p = TREE_VALUE (alloc_size); | |
412 | ||
413 | arg1 = TREE_INT_CST_LOW (TREE_VALUE (p))-1; | |
414 | if (TREE_CHAIN (p)) | |
726a989a | 415 | arg2 = TREE_INT_CST_LOW (TREE_VALUE (TREE_CHAIN (p)))-1; |
51bc54a6 | 416 | } |
b8698a0f | 417 | |
51bc54a6 | 418 | if (DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL) |
10a0d495 JJ |
419 | switch (DECL_FUNCTION_CODE (callee)) |
420 | { | |
51bc54a6 DM |
421 | case BUILT_IN_CALLOC: |
422 | arg2 = 1; | |
423 | /* fall through */ | |
10a0d495 JJ |
424 | case BUILT_IN_MALLOC: |
425 | case BUILT_IN_ALLOCA: | |
13e49da9 | 426 | case BUILT_IN_ALLOCA_WITH_ALIGN: |
51bc54a6 | 427 | arg1 = 0; |
10a0d495 JJ |
428 | default: |
429 | break; | |
430 | } | |
431 | ||
726a989a RB |
432 | if (arg1 < 0 || arg1 >= (int)gimple_call_num_args (call) |
433 | || TREE_CODE (gimple_call_arg (call, arg1)) != INTEGER_CST | |
b8698a0f | 434 | || (arg2 >= 0 |
726a989a RB |
435 | && (arg2 >= (int)gimple_call_num_args (call) |
436 | || TREE_CODE (gimple_call_arg (call, arg2)) != INTEGER_CST))) | |
b8698a0f | 437 | return unknown[object_size_type]; |
51bc54a6 DM |
438 | |
439 | if (arg2 >= 0) | |
440 | bytes = size_binop (MULT_EXPR, | |
726a989a RB |
441 | fold_convert (sizetype, gimple_call_arg (call, arg1)), |
442 | fold_convert (sizetype, gimple_call_arg (call, arg2))); | |
51bc54a6 | 443 | else if (arg1 >= 0) |
726a989a | 444 | bytes = fold_convert (sizetype, gimple_call_arg (call, arg1)); |
51bc54a6 | 445 | |
cc269bb6 | 446 | if (bytes && tree_fits_uhwi_p (bytes)) |
ae7e9ddd | 447 | return tree_to_uhwi (bytes); |
10a0d495 JJ |
448 | |
449 | return unknown[object_size_type]; | |
450 | } | |
451 | ||
452 | ||
453 | /* If object size is propagated from one of function's arguments directly | |
726a989a | 454 | to its return value, return that argument for GIMPLE_CALL statement CALL. |
10a0d495 JJ |
455 | Otherwise return NULL. */ |
456 | ||
457 | static tree | |
726a989a | 458 | pass_through_call (const_gimple call) |
10a0d495 | 459 | { |
726a989a | 460 | tree callee = gimple_call_fndecl (call); |
10a0d495 JJ |
461 | |
462 | if (callee | |
463 | && DECL_BUILT_IN_CLASS (callee) == BUILT_IN_NORMAL) | |
464 | switch (DECL_FUNCTION_CODE (callee)) | |
465 | { | |
466 | case BUILT_IN_MEMCPY: | |
467 | case BUILT_IN_MEMMOVE: | |
468 | case BUILT_IN_MEMSET: | |
469 | case BUILT_IN_STRCPY: | |
470 | case BUILT_IN_STRNCPY: | |
471 | case BUILT_IN_STRCAT: | |
472 | case BUILT_IN_STRNCAT: | |
473 | case BUILT_IN_MEMCPY_CHK: | |
474 | case BUILT_IN_MEMMOVE_CHK: | |
475 | case BUILT_IN_MEMSET_CHK: | |
476 | case BUILT_IN_STRCPY_CHK: | |
477 | case BUILT_IN_STRNCPY_CHK: | |
f3fc9b80 | 478 | case BUILT_IN_STPNCPY_CHK: |
10a0d495 JJ |
479 | case BUILT_IN_STRCAT_CHK: |
480 | case BUILT_IN_STRNCAT_CHK: | |
8b1bdcc5 | 481 | case BUILT_IN_ASSUME_ALIGNED: |
726a989a RB |
482 | if (gimple_call_num_args (call) >= 1) |
483 | return gimple_call_arg (call, 0); | |
10a0d495 JJ |
484 | break; |
485 | default: | |
486 | break; | |
487 | } | |
488 | ||
489 | return NULL_TREE; | |
490 | } | |
491 | ||
492 | ||
493 | /* Compute __builtin_object_size value for PTR. OBJECT_SIZE_TYPE is the | |
494 | second argument from __builtin_object_size. */ | |
495 | ||
496 | unsigned HOST_WIDE_INT | |
497 | compute_builtin_object_size (tree ptr, int object_size_type) | |
498 | { | |
499 | gcc_assert (object_size_type >= 0 && object_size_type <= 3); | |
500 | ||
501 | if (! offset_limit) | |
502 | init_offset_limit (); | |
503 | ||
504 | if (TREE_CODE (ptr) == ADDR_EXPR) | |
eb9ed98a | 505 | return addr_object_size (NULL, ptr, object_size_type); |
10a0d495 | 506 | |
726a989a | 507 | if (TREE_CODE (ptr) == SSA_NAME |
eb9ed98a | 508 | && POINTER_TYPE_P (TREE_TYPE (ptr)) |
db84d11e | 509 | && computed[object_size_type] != NULL) |
10a0d495 JJ |
510 | { |
511 | if (!bitmap_bit_p (computed[object_size_type], SSA_NAME_VERSION (ptr))) | |
512 | { | |
513 | struct object_size_info osi; | |
514 | bitmap_iterator bi; | |
515 | unsigned int i; | |
516 | ||
db84d11e JJ |
517 | if (num_ssa_names > object_sizes[object_size_type].length ()) |
518 | object_sizes[object_size_type].safe_grow (num_ssa_names); | |
10a0d495 JJ |
519 | if (dump_file) |
520 | { | |
521 | fprintf (dump_file, "Computing %s %sobject size for ", | |
522 | (object_size_type & 2) ? "minimum" : "maximum", | |
523 | (object_size_type & 1) ? "sub" : ""); | |
524 | print_generic_expr (dump_file, ptr, dump_flags); | |
525 | fprintf (dump_file, ":\n"); | |
526 | } | |
527 | ||
528 | osi.visited = BITMAP_ALLOC (NULL); | |
529 | osi.reexamine = BITMAP_ALLOC (NULL); | |
530 | osi.object_size_type = object_size_type; | |
531 | osi.depths = NULL; | |
532 | osi.stack = NULL; | |
533 | osi.tos = NULL; | |
534 | ||
535 | /* First pass: walk UD chains, compute object sizes that | |
536 | can be computed. osi.reexamine bitmap at the end will | |
537 | contain what variables were found in dependency cycles | |
538 | and therefore need to be reexamined. */ | |
539 | osi.pass = 0; | |
540 | osi.changed = false; | |
541 | collect_object_sizes_for (&osi, ptr); | |
542 | ||
543 | /* Second pass: keep recomputing object sizes of variables | |
544 | that need reexamination, until no object sizes are | |
545 | increased or all object sizes are computed. */ | |
546 | if (! bitmap_empty_p (osi.reexamine)) | |
547 | { | |
548 | bitmap reexamine = BITMAP_ALLOC (NULL); | |
549 | ||
550 | /* If looking for minimum instead of maximum object size, | |
551 | detect cases where a pointer is increased in a loop. | |
552 | Although even without this detection pass 2 would eventually | |
553 | terminate, it could take a long time. If a pointer is | |
554 | increasing this way, we need to assume 0 object size. | |
555 | E.g. p = &buf[0]; while (cond) p = p + 4; */ | |
556 | if (object_size_type & 2) | |
557 | { | |
5ed6ace5 MD |
558 | osi.depths = XCNEWVEC (unsigned int, num_ssa_names); |
559 | osi.stack = XNEWVEC (unsigned int, num_ssa_names); | |
10a0d495 JJ |
560 | osi.tos = osi.stack; |
561 | osi.pass = 1; | |
562 | /* collect_object_sizes_for is changing | |
563 | osi.reexamine bitmap, so iterate over a copy. */ | |
564 | bitmap_copy (reexamine, osi.reexamine); | |
565 | EXECUTE_IF_SET_IN_BITMAP (reexamine, 0, i, bi) | |
566 | if (bitmap_bit_p (osi.reexamine, i)) | |
567 | check_for_plus_in_loops (&osi, ssa_name (i)); | |
568 | ||
569 | free (osi.depths); | |
570 | osi.depths = NULL; | |
571 | free (osi.stack); | |
572 | osi.stack = NULL; | |
573 | osi.tos = NULL; | |
574 | } | |
575 | ||
576 | do | |
577 | { | |
578 | osi.pass = 2; | |
579 | osi.changed = false; | |
580 | /* collect_object_sizes_for is changing | |
581 | osi.reexamine bitmap, so iterate over a copy. */ | |
582 | bitmap_copy (reexamine, osi.reexamine); | |
583 | EXECUTE_IF_SET_IN_BITMAP (reexamine, 0, i, bi) | |
584 | if (bitmap_bit_p (osi.reexamine, i)) | |
585 | { | |
586 | collect_object_sizes_for (&osi, ssa_name (i)); | |
587 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
588 | { | |
589 | fprintf (dump_file, "Reexamining "); | |
590 | print_generic_expr (dump_file, ssa_name (i), | |
591 | dump_flags); | |
592 | fprintf (dump_file, "\n"); | |
593 | } | |
594 | } | |
595 | } | |
596 | while (osi.changed); | |
597 | ||
598 | BITMAP_FREE (reexamine); | |
599 | } | |
600 | EXECUTE_IF_SET_IN_BITMAP (osi.reexamine, 0, i, bi) | |
601 | bitmap_set_bit (computed[object_size_type], i); | |
602 | ||
603 | /* Debugging dumps. */ | |
604 | if (dump_file) | |
605 | { | |
606 | EXECUTE_IF_SET_IN_BITMAP (osi.visited, 0, i, bi) | |
607 | if (object_sizes[object_size_type][i] | |
608 | != unknown[object_size_type]) | |
609 | { | |
610 | print_generic_expr (dump_file, ssa_name (i), | |
611 | dump_flags); | |
612 | fprintf (dump_file, | |
613 | ": %s %sobject size " | |
614 | HOST_WIDE_INT_PRINT_UNSIGNED "\n", | |
615 | (object_size_type & 2) ? "minimum" : "maximum", | |
616 | (object_size_type & 1) ? "sub" : "", | |
617 | object_sizes[object_size_type][i]); | |
618 | } | |
619 | } | |
620 | ||
621 | BITMAP_FREE (osi.reexamine); | |
622 | BITMAP_FREE (osi.visited); | |
623 | } | |
624 | ||
625 | return object_sizes[object_size_type][SSA_NAME_VERSION (ptr)]; | |
626 | } | |
627 | ||
628 | return unknown[object_size_type]; | |
629 | } | |
630 | ||
726a989a | 631 | /* Compute object_sizes for PTR, defined to VALUE, which is not an SSA_NAME. */ |
10a0d495 JJ |
632 | |
633 | static void | |
634 | expr_object_size (struct object_size_info *osi, tree ptr, tree value) | |
635 | { | |
636 | int object_size_type = osi->object_size_type; | |
637 | unsigned int varno = SSA_NAME_VERSION (ptr); | |
638 | unsigned HOST_WIDE_INT bytes; | |
639 | ||
640 | gcc_assert (object_sizes[object_size_type][varno] | |
641 | != unknown[object_size_type]); | |
642 | gcc_assert (osi->pass == 0); | |
643 | ||
644 | if (TREE_CODE (value) == WITH_SIZE_EXPR) | |
645 | value = TREE_OPERAND (value, 0); | |
646 | ||
647 | /* Pointer variables should have been handled by merge_object_sizes. */ | |
648 | gcc_assert (TREE_CODE (value) != SSA_NAME | |
649 | || !POINTER_TYPE_P (TREE_TYPE (value))); | |
650 | ||
651 | if (TREE_CODE (value) == ADDR_EXPR) | |
eb9ed98a | 652 | bytes = addr_object_size (osi, value, object_size_type); |
10a0d495 JJ |
653 | else |
654 | bytes = unknown[object_size_type]; | |
655 | ||
656 | if ((object_size_type & 2) == 0) | |
657 | { | |
658 | if (object_sizes[object_size_type][varno] < bytes) | |
659 | object_sizes[object_size_type][varno] = bytes; | |
660 | } | |
661 | else | |
662 | { | |
663 | if (object_sizes[object_size_type][varno] > bytes) | |
664 | object_sizes[object_size_type][varno] = bytes; | |
665 | } | |
666 | } | |
667 | ||
668 | ||
726a989a RB |
669 | /* Compute object_sizes for PTR, defined to the result of a call. */ |
670 | ||
671 | static void | |
672 | call_object_size (struct object_size_info *osi, tree ptr, gimple call) | |
673 | { | |
674 | int object_size_type = osi->object_size_type; | |
675 | unsigned int varno = SSA_NAME_VERSION (ptr); | |
676 | unsigned HOST_WIDE_INT bytes; | |
677 | ||
678 | gcc_assert (is_gimple_call (call)); | |
679 | ||
680 | gcc_assert (object_sizes[object_size_type][varno] | |
681 | != unknown[object_size_type]); | |
682 | gcc_assert (osi->pass == 0); | |
683 | ||
684 | bytes = alloc_object_size (call, object_size_type); | |
685 | ||
686 | if ((object_size_type & 2) == 0) | |
687 | { | |
688 | if (object_sizes[object_size_type][varno] < bytes) | |
689 | object_sizes[object_size_type][varno] = bytes; | |
690 | } | |
691 | else | |
692 | { | |
693 | if (object_sizes[object_size_type][varno] > bytes) | |
694 | object_sizes[object_size_type][varno] = bytes; | |
695 | } | |
696 | } | |
697 | ||
698 | ||
699 | /* Compute object_sizes for PTR, defined to an unknown value. */ | |
700 | ||
701 | static void | |
702 | unknown_object_size (struct object_size_info *osi, tree ptr) | |
703 | { | |
704 | int object_size_type = osi->object_size_type; | |
705 | unsigned int varno = SSA_NAME_VERSION (ptr); | |
706 | unsigned HOST_WIDE_INT bytes; | |
707 | ||
708 | gcc_assert (object_sizes[object_size_type][varno] | |
709 | != unknown[object_size_type]); | |
710 | gcc_assert (osi->pass == 0); | |
711 | ||
712 | bytes = unknown[object_size_type]; | |
713 | ||
714 | if ((object_size_type & 2) == 0) | |
715 | { | |
716 | if (object_sizes[object_size_type][varno] < bytes) | |
717 | object_sizes[object_size_type][varno] = bytes; | |
718 | } | |
719 | else | |
720 | { | |
721 | if (object_sizes[object_size_type][varno] > bytes) | |
722 | object_sizes[object_size_type][varno] = bytes; | |
723 | } | |
724 | } | |
725 | ||
726 | ||
10a0d495 JJ |
727 | /* Merge object sizes of ORIG + OFFSET into DEST. Return true if |
728 | the object size might need reexamination later. */ | |
729 | ||
730 | static bool | |
731 | merge_object_sizes (struct object_size_info *osi, tree dest, tree orig, | |
732 | unsigned HOST_WIDE_INT offset) | |
733 | { | |
734 | int object_size_type = osi->object_size_type; | |
735 | unsigned int varno = SSA_NAME_VERSION (dest); | |
736 | unsigned HOST_WIDE_INT orig_bytes; | |
737 | ||
738 | if (object_sizes[object_size_type][varno] == unknown[object_size_type]) | |
739 | return false; | |
740 | if (offset >= offset_limit) | |
741 | { | |
742 | object_sizes[object_size_type][varno] = unknown[object_size_type]; | |
743 | return false; | |
744 | } | |
745 | ||
746 | if (osi->pass == 0) | |
747 | collect_object_sizes_for (osi, orig); | |
748 | ||
749 | orig_bytes = object_sizes[object_size_type][SSA_NAME_VERSION (orig)]; | |
750 | if (orig_bytes != unknown[object_size_type]) | |
751 | orig_bytes = (offset > orig_bytes) | |
752 | ? (unsigned HOST_WIDE_INT) 0 : orig_bytes - offset; | |
753 | ||
754 | if ((object_size_type & 2) == 0) | |
755 | { | |
756 | if (object_sizes[object_size_type][varno] < orig_bytes) | |
757 | { | |
758 | object_sizes[object_size_type][varno] = orig_bytes; | |
759 | osi->changed = true; | |
760 | } | |
761 | } | |
762 | else | |
763 | { | |
764 | if (object_sizes[object_size_type][varno] > orig_bytes) | |
765 | { | |
766 | object_sizes[object_size_type][varno] = orig_bytes; | |
767 | osi->changed = true; | |
768 | } | |
769 | } | |
770 | return bitmap_bit_p (osi->reexamine, SSA_NAME_VERSION (orig)); | |
771 | } | |
772 | ||
773 | ||
726a989a RB |
774 | /* Compute object_sizes for VAR, defined to the result of an assignment |
775 | with operator POINTER_PLUS_EXPR. Return true if the object size might | |
776 | need reexamination later. */ | |
10a0d495 JJ |
777 | |
778 | static bool | |
726a989a | 779 | plus_stmt_object_size (struct object_size_info *osi, tree var, gimple stmt) |
10a0d495 | 780 | { |
10a0d495 JJ |
781 | int object_size_type = osi->object_size_type; |
782 | unsigned int varno = SSA_NAME_VERSION (var); | |
783 | unsigned HOST_WIDE_INT bytes; | |
726a989a RB |
784 | tree op0, op1; |
785 | ||
70f34814 RG |
786 | if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR) |
787 | { | |
788 | op0 = gimple_assign_rhs1 (stmt); | |
789 | op1 = gimple_assign_rhs2 (stmt); | |
790 | } | |
791 | else if (gimple_assign_rhs_code (stmt) == ADDR_EXPR) | |
792 | { | |
793 | tree rhs = TREE_OPERAND (gimple_assign_rhs1 (stmt), 0); | |
794 | gcc_assert (TREE_CODE (rhs) == MEM_REF); | |
795 | op0 = TREE_OPERAND (rhs, 0); | |
796 | op1 = TREE_OPERAND (rhs, 1); | |
797 | } | |
798 | else | |
799 | gcc_unreachable (); | |
10a0d495 JJ |
800 | |
801 | if (object_sizes[object_size_type][varno] == unknown[object_size_type]) | |
802 | return false; | |
803 | ||
10a0d495 | 804 | /* Handle PTR + OFFSET here. */ |
5be014d5 | 805 | if (TREE_CODE (op1) == INTEGER_CST |
10a0d495 JJ |
806 | && (TREE_CODE (op0) == SSA_NAME |
807 | || TREE_CODE (op0) == ADDR_EXPR)) | |
808 | { | |
cc269bb6 | 809 | if (! tree_fits_uhwi_p (op1)) |
10a0d495 JJ |
810 | bytes = unknown[object_size_type]; |
811 | else if (TREE_CODE (op0) == SSA_NAME) | |
ae7e9ddd | 812 | return merge_object_sizes (osi, var, op0, tree_to_uhwi (op1)); |
10a0d495 JJ |
813 | else |
814 | { | |
ae7e9ddd | 815 | unsigned HOST_WIDE_INT off = tree_to_uhwi (op1); |
10a0d495 | 816 | |
726a989a | 817 | /* op0 will be ADDR_EXPR here. */ |
eb9ed98a | 818 | bytes = addr_object_size (osi, op0, object_size_type); |
ac5a28a6 JH |
819 | if (bytes == unknown[object_size_type]) |
820 | ; | |
821 | else if (off > offset_limit) | |
10a0d495 JJ |
822 | bytes = unknown[object_size_type]; |
823 | else if (off > bytes) | |
824 | bytes = 0; | |
825 | else | |
826 | bytes -= off; | |
827 | } | |
828 | } | |
829 | else | |
830 | bytes = unknown[object_size_type]; | |
831 | ||
832 | if ((object_size_type & 2) == 0) | |
833 | { | |
834 | if (object_sizes[object_size_type][varno] < bytes) | |
835 | object_sizes[object_size_type][varno] = bytes; | |
836 | } | |
837 | else | |
838 | { | |
839 | if (object_sizes[object_size_type][varno] > bytes) | |
840 | object_sizes[object_size_type][varno] = bytes; | |
841 | } | |
842 | return false; | |
843 | } | |
844 | ||
845 | ||
4e71066d | 846 | /* Compute object_sizes for VAR, defined at STMT, which is |
f255541f RC |
847 | a COND_EXPR. Return true if the object size might need reexamination |
848 | later. */ | |
849 | ||
850 | static bool | |
4e71066d | 851 | cond_expr_object_size (struct object_size_info *osi, tree var, gimple stmt) |
f255541f RC |
852 | { |
853 | tree then_, else_; | |
854 | int object_size_type = osi->object_size_type; | |
855 | unsigned int varno = SSA_NAME_VERSION (var); | |
856 | bool reexamine = false; | |
857 | ||
4e71066d | 858 | gcc_assert (gimple_assign_rhs_code (stmt) == COND_EXPR); |
f255541f RC |
859 | |
860 | if (object_sizes[object_size_type][varno] == unknown[object_size_type]) | |
861 | return false; | |
862 | ||
4e71066d RG |
863 | then_ = gimple_assign_rhs2 (stmt); |
864 | else_ = gimple_assign_rhs3 (stmt); | |
f255541f RC |
865 | |
866 | if (TREE_CODE (then_) == SSA_NAME) | |
867 | reexamine |= merge_object_sizes (osi, var, then_, 0); | |
868 | else | |
869 | expr_object_size (osi, var, then_); | |
870 | ||
871 | if (TREE_CODE (else_) == SSA_NAME) | |
872 | reexamine |= merge_object_sizes (osi, var, else_, 0); | |
873 | else | |
874 | expr_object_size (osi, var, else_); | |
875 | ||
876 | return reexamine; | |
877 | } | |
878 | ||
10a0d495 JJ |
879 | /* Compute object sizes for VAR. |
880 | For ADDR_EXPR an object size is the number of remaining bytes | |
619519c8 | 881 | to the end of the object (where what is considered an object depends on |
10a0d495 | 882 | OSI->object_size_type). |
726a989a | 883 | For allocation GIMPLE_CALL like malloc or calloc object size is the size |
10a0d495 | 884 | of the allocation. |
5be014d5 | 885 | For POINTER_PLUS_EXPR where second operand is a constant integer, |
10a0d495 JJ |
886 | object size is object size of the first operand minus the constant. |
887 | If the constant is bigger than the number of remaining bytes until the | |
888 | end of the object, object size is 0, but if it is instead a pointer | |
889 | subtraction, object size is unknown[object_size_type]. | |
890 | To differentiate addition from subtraction, ADDR_EXPR returns | |
891 | unknown[object_size_type] for all objects bigger than half of the address | |
892 | space, and constants less than half of the address space are considered | |
893 | addition, while bigger constants subtraction. | |
726a989a | 894 | For a memcpy like GIMPLE_CALL that always returns one of its arguments, the |
10a0d495 JJ |
895 | object size is object size of that argument. |
896 | Otherwise, object size is the maximum of object sizes of variables | |
897 | that it might be set to. */ | |
898 | ||
899 | static void | |
900 | collect_object_sizes_for (struct object_size_info *osi, tree var) | |
901 | { | |
902 | int object_size_type = osi->object_size_type; | |
903 | unsigned int varno = SSA_NAME_VERSION (var); | |
726a989a | 904 | gimple stmt; |
10a0d495 JJ |
905 | bool reexamine; |
906 | ||
907 | if (bitmap_bit_p (computed[object_size_type], varno)) | |
908 | return; | |
909 | ||
910 | if (osi->pass == 0) | |
911 | { | |
fcaa4ca4 | 912 | if (bitmap_set_bit (osi->visited, varno)) |
10a0d495 | 913 | { |
10a0d495 JJ |
914 | object_sizes[object_size_type][varno] |
915 | = (object_size_type & 2) ? -1 : 0; | |
916 | } | |
917 | else | |
918 | { | |
919 | /* Found a dependency loop. Mark the variable for later | |
920 | re-examination. */ | |
921 | bitmap_set_bit (osi->reexamine, varno); | |
922 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
923 | { | |
924 | fprintf (dump_file, "Found a dependency loop at "); | |
925 | print_generic_expr (dump_file, var, dump_flags); | |
926 | fprintf (dump_file, "\n"); | |
927 | } | |
928 | return; | |
929 | } | |
930 | } | |
931 | ||
932 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
933 | { | |
934 | fprintf (dump_file, "Visiting use-def links for "); | |
935 | print_generic_expr (dump_file, var, dump_flags); | |
936 | fprintf (dump_file, "\n"); | |
937 | } | |
938 | ||
939 | stmt = SSA_NAME_DEF_STMT (var); | |
940 | reexamine = false; | |
941 | ||
726a989a | 942 | switch (gimple_code (stmt)) |
10a0d495 | 943 | { |
726a989a | 944 | case GIMPLE_ASSIGN: |
10a0d495 | 945 | { |
70f34814 RG |
946 | tree rhs = gimple_assign_rhs1 (stmt); |
947 | if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR | |
948 | || (gimple_assign_rhs_code (stmt) == ADDR_EXPR | |
949 | && TREE_CODE (TREE_OPERAND (rhs, 0)) == MEM_REF)) | |
726a989a | 950 | reexamine = plus_stmt_object_size (osi, var, stmt); |
4e71066d RG |
951 | else if (gimple_assign_rhs_code (stmt) == COND_EXPR) |
952 | reexamine = cond_expr_object_size (osi, var, stmt); | |
726a989a RB |
953 | else if (gimple_assign_single_p (stmt) |
954 | || gimple_assign_unary_nop_p (stmt)) | |
955 | { | |
726a989a RB |
956 | if (TREE_CODE (rhs) == SSA_NAME |
957 | && POINTER_TYPE_P (TREE_TYPE (rhs))) | |
958 | reexamine = merge_object_sizes (osi, var, rhs, 0); | |
726a989a RB |
959 | else |
960 | expr_object_size (osi, var, rhs); | |
961 | } | |
962 | else | |
963 | unknown_object_size (osi, var); | |
964 | break; | |
965 | } | |
f255541f | 966 | |
726a989a RB |
967 | case GIMPLE_CALL: |
968 | { | |
969 | tree arg = pass_through_call (stmt); | |
970 | if (arg) | |
971 | { | |
972 | if (TREE_CODE (arg) == SSA_NAME | |
973 | && POINTER_TYPE_P (TREE_TYPE (arg))) | |
974 | reexamine = merge_object_sizes (osi, var, arg, 0); | |
726a989a RB |
975 | else |
976 | expr_object_size (osi, var, arg); | |
977 | } | |
978 | else | |
979 | call_object_size (osi, var, stmt); | |
10a0d495 JJ |
980 | break; |
981 | } | |
982 | ||
726a989a | 983 | case GIMPLE_ASM: |
10a0d495 JJ |
984 | /* Pointers defined by __asm__ statements can point anywhere. */ |
985 | object_sizes[object_size_type][varno] = unknown[object_size_type]; | |
986 | break; | |
987 | ||
726a989a | 988 | case GIMPLE_NOP: |
70b5e7dc RG |
989 | if (SSA_NAME_VAR (var) |
990 | && TREE_CODE (SSA_NAME_VAR (var)) == PARM_DECL) | |
991 | expr_object_size (osi, var, SSA_NAME_VAR (var)); | |
992 | else | |
993 | /* Uninitialized SSA names point nowhere. */ | |
994 | object_sizes[object_size_type][varno] = unknown[object_size_type]; | |
10a0d495 JJ |
995 | break; |
996 | ||
726a989a | 997 | case GIMPLE_PHI: |
10a0d495 | 998 | { |
726a989a | 999 | unsigned i; |
10a0d495 | 1000 | |
726a989a | 1001 | for (i = 0; i < gimple_phi_num_args (stmt); i++) |
10a0d495 | 1002 | { |
726a989a | 1003 | tree rhs = gimple_phi_arg (stmt, i)->def; |
10a0d495 JJ |
1004 | |
1005 | if (object_sizes[object_size_type][varno] | |
1006 | == unknown[object_size_type]) | |
1007 | break; | |
1008 | ||
1009 | if (TREE_CODE (rhs) == SSA_NAME) | |
1010 | reexamine |= merge_object_sizes (osi, var, rhs, 0); | |
1011 | else if (osi->pass == 0) | |
1012 | expr_object_size (osi, var, rhs); | |
1013 | } | |
1014 | break; | |
1015 | } | |
726a989a | 1016 | |
10a0d495 JJ |
1017 | default: |
1018 | gcc_unreachable (); | |
1019 | } | |
1020 | ||
1021 | if (! reexamine | |
1022 | || object_sizes[object_size_type][varno] == unknown[object_size_type]) | |
1023 | { | |
1024 | bitmap_set_bit (computed[object_size_type], varno); | |
1025 | bitmap_clear_bit (osi->reexamine, varno); | |
1026 | } | |
1027 | else | |
1028 | { | |
1029 | bitmap_set_bit (osi->reexamine, varno); | |
1030 | if (dump_file && (dump_flags & TDF_DETAILS)) | |
1031 | { | |
1032 | fprintf (dump_file, "Need to reexamine "); | |
1033 | print_generic_expr (dump_file, var, dump_flags); | |
1034 | fprintf (dump_file, "\n"); | |
1035 | } | |
1036 | } | |
1037 | } | |
1038 | ||
1039 | ||
1040 | /* Helper function for check_for_plus_in_loops. Called recursively | |
1041 | to detect loops. */ | |
1042 | ||
1043 | static void | |
1044 | check_for_plus_in_loops_1 (struct object_size_info *osi, tree var, | |
1045 | unsigned int depth) | |
1046 | { | |
726a989a | 1047 | gimple stmt = SSA_NAME_DEF_STMT (var); |
10a0d495 JJ |
1048 | unsigned int varno = SSA_NAME_VERSION (var); |
1049 | ||
1050 | if (osi->depths[varno]) | |
1051 | { | |
1052 | if (osi->depths[varno] != depth) | |
1053 | { | |
1054 | unsigned int *sp; | |
1055 | ||
1056 | /* Found a loop involving pointer addition. */ | |
1057 | for (sp = osi->tos; sp > osi->stack; ) | |
1058 | { | |
1059 | --sp; | |
1060 | bitmap_clear_bit (osi->reexamine, *sp); | |
1061 | bitmap_set_bit (computed[osi->object_size_type], *sp); | |
1062 | object_sizes[osi->object_size_type][*sp] = 0; | |
1063 | if (*sp == varno) | |
1064 | break; | |
1065 | } | |
1066 | } | |
1067 | return; | |
1068 | } | |
1069 | else if (! bitmap_bit_p (osi->reexamine, varno)) | |
1070 | return; | |
1071 | ||
1072 | osi->depths[varno] = depth; | |
1073 | *osi->tos++ = varno; | |
1074 | ||
726a989a | 1075 | switch (gimple_code (stmt)) |
10a0d495 | 1076 | { |
10a0d495 | 1077 | |
726a989a | 1078 | case GIMPLE_ASSIGN: |
10a0d495 | 1079 | { |
726a989a RB |
1080 | if ((gimple_assign_single_p (stmt) |
1081 | || gimple_assign_unary_nop_p (stmt)) | |
1082 | && TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME) | |
1083 | { | |
1084 | tree rhs = gimple_assign_rhs1 (stmt); | |
1085 | ||
1086 | check_for_plus_in_loops_1 (osi, rhs, depth); | |
1087 | } | |
1088 | else if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR) | |
1089 | { | |
1090 | tree basevar = gimple_assign_rhs1 (stmt); | |
1091 | tree cst = gimple_assign_rhs2 (stmt); | |
1092 | ||
1093 | gcc_assert (TREE_CODE (cst) == INTEGER_CST); | |
1094 | ||
1095 | check_for_plus_in_loops_1 (osi, basevar, | |
1096 | depth + !integer_zerop (cst)); | |
1097 | } | |
1098 | else | |
1099 | gcc_unreachable (); | |
1100 | break; | |
1101 | } | |
10a0d495 | 1102 | |
726a989a RB |
1103 | case GIMPLE_CALL: |
1104 | { | |
1105 | tree arg = pass_through_call (stmt); | |
1106 | if (arg) | |
1107 | { | |
1108 | if (TREE_CODE (arg) == SSA_NAME) | |
1109 | check_for_plus_in_loops_1 (osi, arg, depth); | |
1110 | else | |
1111 | gcc_unreachable (); | |
1112 | } | |
1113 | break; | |
10a0d495 | 1114 | } |
726a989a RB |
1115 | |
1116 | case GIMPLE_PHI: | |
10a0d495 | 1117 | { |
726a989a | 1118 | unsigned i; |
10a0d495 | 1119 | |
726a989a | 1120 | for (i = 0; i < gimple_phi_num_args (stmt); i++) |
10a0d495 | 1121 | { |
726a989a | 1122 | tree rhs = gimple_phi_arg (stmt, i)->def; |
10a0d495 JJ |
1123 | |
1124 | if (TREE_CODE (rhs) == SSA_NAME) | |
1125 | check_for_plus_in_loops_1 (osi, rhs, depth); | |
1126 | } | |
1127 | break; | |
1128 | } | |
726a989a | 1129 | |
10a0d495 JJ |
1130 | default: |
1131 | gcc_unreachable (); | |
1132 | } | |
1133 | ||
1134 | osi->depths[varno] = 0; | |
1135 | osi->tos--; | |
1136 | } | |
1137 | ||
1138 | ||
1139 | /* Check if some pointer we are computing object size of is being increased | |
1140 | within a loop. If yes, assume all the SSA variables participating in | |
1141 | that loop have minimum object sizes 0. */ | |
1142 | ||
1143 | static void | |
1144 | check_for_plus_in_loops (struct object_size_info *osi, tree var) | |
1145 | { | |
726a989a | 1146 | gimple stmt = SSA_NAME_DEF_STMT (var); |
10a0d495 | 1147 | |
726a989a RB |
1148 | /* NOTE: In the pre-tuples code, we handled a CALL_EXPR here, |
1149 | and looked for a POINTER_PLUS_EXPR in the pass-through | |
1150 | argument, if any. In GIMPLE, however, such an expression | |
1151 | is not a valid call operand. */ | |
10a0d495 | 1152 | |
726a989a RB |
1153 | if (is_gimple_assign (stmt) |
1154 | && gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR) | |
1155 | { | |
1156 | tree basevar = gimple_assign_rhs1 (stmt); | |
1157 | tree cst = gimple_assign_rhs2 (stmt); | |
b8698a0f | 1158 | |
726a989a RB |
1159 | gcc_assert (TREE_CODE (cst) == INTEGER_CST); |
1160 | ||
1161 | if (integer_zerop (cst)) | |
1162 | return; | |
1163 | ||
1164 | osi->depths[SSA_NAME_VERSION (basevar)] = 1; | |
1165 | *osi->tos++ = SSA_NAME_VERSION (basevar); | |
1166 | check_for_plus_in_loops_1 (osi, var, 2); | |
1167 | osi->depths[SSA_NAME_VERSION (basevar)] = 0; | |
1168 | osi->tos--; | |
10a0d495 JJ |
1169 | } |
1170 | } | |
1171 | ||
1172 | ||
1173 | /* Initialize data structures for the object size computation. */ | |
1174 | ||
1175 | void | |
1176 | init_object_sizes (void) | |
1177 | { | |
1178 | int object_size_type; | |
1179 | ||
db84d11e | 1180 | if (computed[0]) |
10a0d495 JJ |
1181 | return; |
1182 | ||
1183 | for (object_size_type = 0; object_size_type <= 3; object_size_type++) | |
1184 | { | |
db84d11e | 1185 | object_sizes[object_size_type].safe_grow (num_ssa_names); |
10a0d495 JJ |
1186 | computed[object_size_type] = BITMAP_ALLOC (NULL); |
1187 | } | |
1188 | ||
1189 | init_offset_limit (); | |
1190 | } | |
1191 | ||
1192 | ||
1193 | /* Destroy data structures after the object size computation. */ | |
1194 | ||
862d0b35 | 1195 | static void |
10a0d495 JJ |
1196 | fini_object_sizes (void) |
1197 | { | |
1198 | int object_size_type; | |
1199 | ||
1200 | for (object_size_type = 0; object_size_type <= 3; object_size_type++) | |
1201 | { | |
db84d11e | 1202 | object_sizes[object_size_type].release (); |
10a0d495 | 1203 | BITMAP_FREE (computed[object_size_type]); |
10a0d495 JJ |
1204 | } |
1205 | } | |
1206 | ||
1207 | ||
1208 | /* Simple pass to optimize all __builtin_object_size () builtins. */ | |
1209 | ||
be55bfe6 TS |
1210 | namespace { |
1211 | ||
1212 | const pass_data pass_data_object_sizes = | |
1213 | { | |
1214 | GIMPLE_PASS, /* type */ | |
1215 | "objsz", /* name */ | |
1216 | OPTGROUP_NONE, /* optinfo_flags */ | |
1217 | true, /* has_execute */ | |
1218 | TV_NONE, /* tv_id */ | |
1219 | ( PROP_cfg | PROP_ssa ), /* properties_required */ | |
1220 | 0, /* properties_provided */ | |
1221 | 0, /* properties_destroyed */ | |
1222 | 0, /* todo_flags_start */ | |
3bea341f | 1223 | 0, /* todo_flags_finish */ |
be55bfe6 TS |
1224 | }; |
1225 | ||
1226 | class pass_object_sizes : public gimple_opt_pass | |
1227 | { | |
1228 | public: | |
1229 | pass_object_sizes (gcc::context *ctxt) | |
1230 | : gimple_opt_pass (pass_data_object_sizes, ctxt) | |
1231 | {} | |
1232 | ||
1233 | /* opt_pass methods: */ | |
1234 | opt_pass * clone () { return new pass_object_sizes (m_ctxt); } | |
1235 | virtual unsigned int execute (function *); | |
1236 | ||
1237 | }; // class pass_object_sizes | |
1238 | ||
1239 | unsigned int | |
1240 | pass_object_sizes::execute (function *fun) | |
10a0d495 JJ |
1241 | { |
1242 | basic_block bb; | |
be55bfe6 | 1243 | FOR_EACH_BB_FN (bb, fun) |
10a0d495 | 1244 | { |
726a989a RB |
1245 | gimple_stmt_iterator i; |
1246 | for (i = gsi_start_bb (bb); !gsi_end_p (i); gsi_next (&i)) | |
10a0d495 | 1247 | { |
1eadb567 | 1248 | tree result; |
726a989a | 1249 | gimple call = gsi_stmt (i); |
1eadb567 | 1250 | if (!gimple_call_builtin_p (call, BUILT_IN_OBJECT_SIZE)) |
10a0d495 JJ |
1251 | continue; |
1252 | ||
1253 | init_object_sizes (); | |
726a989a | 1254 | result = fold_call_stmt (call, false); |
10a0d495 JJ |
1255 | if (!result) |
1256 | { | |
726a989a RB |
1257 | if (gimple_call_num_args (call) == 2 |
1258 | && POINTER_TYPE_P (TREE_TYPE (gimple_call_arg (call, 0)))) | |
10a0d495 | 1259 | { |
726a989a | 1260 | tree ost = gimple_call_arg (call, 1); |
10a0d495 | 1261 | |
cc269bb6 | 1262 | if (tree_fits_uhwi_p (ost)) |
10a0d495 JJ |
1263 | { |
1264 | unsigned HOST_WIDE_INT object_size_type | |
ae7e9ddd | 1265 | = tree_to_uhwi (ost); |
10a0d495 JJ |
1266 | |
1267 | if (object_size_type < 2) | |
1268 | result = fold_convert (size_type_node, | |
1269 | integer_minus_one_node); | |
1270 | else if (object_size_type < 4) | |
e8160c9a | 1271 | result = build_zero_cst (size_type_node); |
10a0d495 JJ |
1272 | } |
1273 | } | |
1274 | ||
1275 | if (!result) | |
1276 | continue; | |
1277 | } | |
1278 | ||
1eadb567 RB |
1279 | gcc_assert (TREE_CODE (result) == INTEGER_CST); |
1280 | ||
10a0d495 JJ |
1281 | if (dump_file && (dump_flags & TDF_DETAILS)) |
1282 | { | |
1283 | fprintf (dump_file, "Simplified\n "); | |
726a989a | 1284 | print_gimple_stmt (dump_file, call, 0, dump_flags); |
1eadb567 RB |
1285 | fprintf (dump_file, " to "); |
1286 | print_generic_expr (dump_file, result, 0); | |
1287 | fprintf (dump_file, "\n"); | |
10a0d495 JJ |
1288 | } |
1289 | ||
1eadb567 RB |
1290 | tree lhs = gimple_call_lhs (call); |
1291 | if (!lhs) | |
1292 | continue; | |
726a989a | 1293 | |
1eadb567 RB |
1294 | /* Propagate into all uses and fold those stmts. */ |
1295 | gimple use_stmt; | |
1296 | imm_use_iterator iter; | |
1297 | FOR_EACH_IMM_USE_STMT (use_stmt, iter, lhs) | |
10a0d495 | 1298 | { |
1eadb567 RB |
1299 | use_operand_p use_p; |
1300 | FOR_EACH_IMM_USE_ON_STMT (use_p, iter) | |
1301 | SET_USE (use_p, result); | |
1302 | gimple_stmt_iterator gsi = gsi_for_stmt (use_stmt); | |
1303 | fold_stmt (&gsi); | |
1304 | update_stmt (gsi_stmt (gsi)); | |
10a0d495 JJ |
1305 | } |
1306 | } | |
1307 | } | |
1308 | ||
1309 | fini_object_sizes (); | |
c2924966 | 1310 | return 0; |
10a0d495 JJ |
1311 | } |
1312 | ||
27a4cd48 DM |
1313 | } // anon namespace |
1314 | ||
1315 | gimple_opt_pass * | |
1316 | make_pass_object_sizes (gcc::context *ctxt) | |
1317 | { | |
1318 | return new pass_object_sizes (ctxt); | |
1319 | } |